The Frequency-hopping Spread Spectrum (FHSS) systems and techniques are using in military and civilianradar recently and in the communication system for securing the information on wireless communications link channels, for example in the Wi-Fi 8.02.X IEEE using multiple number bandwidth and frequencies in the wireless channel in order to hopping on them for increasing the security level during the broadcast, but nowadays FHSS problem, which is, any Smart Software Defined Radio (S-SDR) can easily detect a wireless signal at the transmitter and the receiver for the hopping sequence in both of these, then duplicate this sequence in order to hack the signal on both transmitter and receiver messages using the order of the sequences that will be recognized for next transmissions. In 2017 Code and Phase Hopping Techniques are both proposed to resolve the most recent problem in security-related, but not with FHSS, therefore in this paper presents a new composed proposed system will progress Phase Shift and Code Hopping in Code Division Multiplexing Access (CDMA) to complement with FHSS; because the wireless Communications systems security in the last years became a nightmare for some individuals, also companies, and even countries, also join them needing for higher bits rate in the wireless channels; because of next-generation communication system 5G-6G and the evolution in social networking, IoT, stream media, IoE, visualizations, and cloud computing. The new ideas can be applicable for a large number of users, also fast implementation without synchronization, as well as without any focus on encryption or keys-exchanges, at completion all results are simulation in MATLAB R2017b, the results have been tested by using 8 users in the same time, also our results showing promises effects on security for both applied systems Phases Shift and Codes Hopping especially the Code Hopping, therefor; our results encouraged us to complete research and compare our system with other.
The Electrical power system has become vast and more complex, so it is subjected to sudden changes in load levels. Stability is an important concept which determines the stable operation of the power system. Transient stability analysis has become one of the significant studies in the power system to ensure the system stability to withstand a considerable disturbance. The effect of temporary occurrence can lead to malfunction of electronic control equipment. The application of flexible AC transmission systems (FACTS) devices in the transmission system have introduced several changes in the power system. These changes have a significant impact on the power system protection, due to differences inline impedance, line curre
... Show MoreThe inverse problem is important method in the design of electrostatic lenses which is used in this work, with new technique by suggesting an axial electrostatic potential distribution using polynomial functions of the third order. The paraxial-ray equation is solved to obtain the trajectory of particles that satisfy the suggested potential function.In this work design of immersion electrostatic lens operated under zero magnification condition. The electrode shape of sthe electrostatic lens was the dermined from the solution of laplace equation and plotted in two deimensions . The results showed low values of spherical and chromatic aberrations , which are considered as good criteria for good desigh.
Designed Mirrors double and triple package adoption concept heap where they were changing the thickness of the layers within periodic basis of the pile and different ratios (p: q) in addition to change the refractive index of materials within periodic basis and its impact on sites Dhour tops high reflectivity study included spectral region visible and infrared, depending on NdharahFeatured matrix adjusted fall of light close to the vertical arrangement multilayer dielectric materials and thin films homogeneous and uniform
Design sampling plan was and still one of most importance subjects because it give lowest cost comparing with others, time live statistical distribution should be known to give best estimators for parameters of sampling plan and get best sampling plan.
Research dell with design sampling plan when live time distribution follow Logistic distribution with () as location and shape parameters, using these information can help us getting (number of groups, sample size) associated with reject or accept the Lot
Experimental results for simulated data shows the least number of groups and sample size needs to reject or accept the Lot with certain probability of
... Show MoreA computerized investigation has been carried out to design an immersion lens
with low aberration operating under zero magnification condition using inverse problem.
The aberration is highly dependent on the shape of electrodes, for a preassigned electron
beam trajectory the paraxial-ray-equation is solved to determine the electrostatic potential
and field distribution.
From the knowledge of the potential and its first and second derivative the
electron optical properties were computed, the electrode geometry was determined from
the solution of Laplace equation.
The aim of this study to identity using Daniel's model and Driver’s model in learning a kinetic chain on the uneven bars in the artistic gymnastics for female students. The researchers used the experimental method to design equivalent groups with a preand post-test, and the research community was identified with the students of the third stage in the college for the academic year 2020-2021 .The subject was, (3) class were randomly selected, so (30) students distributed into (3) groups). has been conducted pretesting after implementation of the curriculum for (4) weeks and used the statistical bag of social sciences(SPSS)to process the results of the research and a set of conclusions was reached, the most important of which is t
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