A hybrid method of genetic algorithm and support vector machine for DNS tunneling detection

With the expansion of the business over the internet, corporations nowadays are investing numerous amounts of money in the web applications. However, there are different threats could make the corporations vulnerable for potential attacks. One of these threats is harnessing the domain name protocol for passing harmful information, this kind of threats is known as DNS tunneling. As a result, confidential information would be exposed and violated. Several studies have investigated the machine learning in order to propose a detection approach. In their approaches, authors have used different and numerous types of features such as domain length, number of bytes, content, volume of DNS traffic, number of hostnames per domain, geographic location and domain history. Apparently, there is a vital demand to accommodate feature selection task in order to identify the best features. This paper proposes a hybrid method of genetic algorithm feature selection approach with the support vector machine classifier for the sake of identifying the best features that have the ability to optimize the detection of DNS tunneling. To evaluate the proposed method, a benchmark dataset of DNS tunneling has been used. Results showed that the proposed method has outperformed the conventional SVM by achieving 0.946 of f-measur

High-resolution rotor-position detection for green vehicle drives at halt condition with statistical view

Considerations around environmental pollution and green energy usage have led to environmentally-friendly machines being used in many industrial applications. Permanent magnet (PM) machines are the best solution to substitute the pollutant diesel-powered machines. In such machines, rotor position detection is crucial for safe startup operating. Meanwhile, encoderless controllers have become more reliable, over the years, in supporting the operation of PM machines. The key point, presented by this paper, is to introduce an improved positioning model to detect the rotor-position of interior permanent magnet synchronous machine at halt condition. To verify this objective, only two short duration pulses were injected into the stator windings. Then, the corresponding terminal voltage and current responses were measured and employed to create two memory address lines. Thereby, the memory cells, which contain the rotor position information, could be accessed. This detection model makes a significant improvement in rotor positioning detection of high resolution (1 degree) which represents lower value than most verified results in literature. The model was simulated and tested in a MATLAB/Simulink environment and shows an approximate accuracy 95%. Additionally, the statistical analysis was also employed to support the work outcomes

Memorized approach for implementation of space vector pulse width modulation

Space Vector Pulse Width Modulation, SV-PWM, is an efficient technique for dc to ac voltage conversion through an inverter of power electronics devices. This paper presents a proposed memorized approach for SV-PWM implementation. The work bases on storing six symmetric pattern formats of space vector in a memory structure. Then, sequential fetching of the stored data provides basic optimum firing triggers TRA, TRB and TRC for driving the inverter switching elements. Main contribution of the paper is controlling the inverter output frequency online through adjusting the fetching period. Moreover, the presented approach characterizes by simplicity, cost effective and activity in achieving the space vector technique. Validity of the proposed method was practically examined through a hardware built workbench, which based on the microcontroller ATMEGA 2560. Meanwhile, the optimum firing sequences were exported to a MATLAB algorithm to check the harmonics, which are expected to accompany the inverter output ac power

Modelling and practical set-up to investigate the performance of permanent magnet synchronous motor through rotor position estimation at zero and low speeds

This thesis provides a study for the rotor position estimation in SM-PMSMs, particularly at zero and low speeds. The method for zero rotor speed is based on injection of three high frequency voltage pulses in the motor stator windings. Then, the voltage responses at the motor terminals are exploited to extract the rotor position. Two approaches, modelling and practical implementations, are presented. The obtained results have showed a verification of a high-resolution position estimation (a position estimation of 1 degree angle), a simplicity and cost effective implementation and a no need for current sensors is required to achieve the estimation process. It should be noticed that the implementation of rotor position estimation at zero speed is only attended when the rotor is at standstill or very low speed. Therefore, the motor driver is not expected to be active at this condition. Thereby, the zero speed estimation does not provide a robust torque control. In future, this should be taking into consideration to overcome this drawback and to make the estimator more reliable. At low speed running, the primary goal is to start spinning the under test motors, and then the rotor position estimation is achieved. The motor spinning is based on adopting a virtual injected signal to generate the voltage components, Vα and Vβ, of the space vector pulse width modulation technique. Then, generating the eight space vectors is conducted through storing the standard patterns of the six space vector sectors in a memory structure together with the timing sequences of each sector. The presented strategy of motor running includes a proposed motor speed control scheme, which is based on controlling the frequency of the power signal, at the inverter output, through controlling the timing period of execution the power delivery program. The thesis presents a proposed method to achieve the estimation goal depends on tracking the magnetic saliency on one motor line voltage. Thereby, the rotor position estimation The introduced proposed method, for rotor position estimation at zero speed, verifies the following contributions: - Presents a simple and cost effective zero speed rotor position estimator for the motor under test. - The aimed resolution in this thesis is an angle 1 degree. IV - Adopting solely the measuring of motor terminal voltages. Eliminating the detection of the rotor magnet polarity as a necessary technique for completing the position estimation. At low speed running, the following contributions are verified: - Rather than a real frequency signal, a virtual injected signal is adopted to generate the voltage components, Vα and Vβ of the space vector pulse width modulation technique. - The proposed method for generating the eight space vectors is based on storing the standard patterns of the six sectors in a memory structure together with the timing sequence. - The strategy of motor speed control is based on controlling the period of execution the power delivery program. - The strategy of low speed rotor position employs one motor line voltage from which the low speed estimation is achieved

Estimation of rotor position for permanent magnet synchronous motor at standstill using sensorless voltage control scheme

The zero-speed rotor position estimation in surface mounted permanent magnet synchronous motor SM-PMSM represents a challenge due to the weak magnetic saliency in this type of motors. This paper presents a new method to estimate the initial rotor position of SM-PMSMs more simply and more accurately without any form of position or current sensors. It achieves this goal through an injection of three short width pulses and employing only the measurements of the motor terminal voltage responses, which fluctuate sinusoidally with the rotor position. Thereby, memory addresses, or dimensions of a look-up table, were created from the readings of the measured voltages. The memory was primarily loaded with 360 angles, each represents 1o angle of rotor positions. The simulated MATLAB model and experimental results demonstrate the advantages. Comparing with the previous related publications, this research work has fulfilled two main contributions. The first is in achieving a rotor position estimation of 1o resolution. The second is in eliminating the technique needed for detection of the rotor magnet polarity. The measured rates of error for the MATLAB model and the practical model were 2% and 5% respectivel

High-resolution rotor-position detection for green vehicle drives at halt condition with statistical view

Considerations around environmental pollution and green energy usage have led to environmentally-friendly machines being used in many industrial applications. Permanent magnet (PM) machines are the best solution to substitute the pollutant diesel-powered machines. In such machines, rotor position detection is crucial for safe startup operating. Meanwhile, encoderless controllers have become more reliable, over the years, in supporting the operation of PM machines. The key point, presented by this paper, is to introduce an improved positioning model to detect the rotor-position of interior permanent magnet synchronous machine at halt condition. To verify this objective, only two short duration pulses were injected into the stator windings. Then, the corresponding terminal voltage and current responses were measured and employed to create two memory address lines. Thereby, the memory cells, which contain the rotor position information, could be accessed. This detection model makes a significant improvement in rotor positioning detection of high resolution (1 degree) which represents lower value than most verified results in literature. The model was simulated and tested in a MATLAB/Simulink environment and shows an approximate accuracy 95%. Additionally, the statistical analysis was also employed to support the work outcomes

BRICS Bloc in Light of International Economic Challenges: A Study of Reality and Dimensions

Originality/value: The BRICS bloc is one of the most important international economic blocs that plays an important role in the global economy, so most of them are moving towards obtaining an economic position that is commensurate with their natural capabilities and capabilities. Russia, India, China and South Africa, represent the emerging economies of the world, and these countries aim to overcome the hegemony of the US currency as a global reserve, and the BRICS group constitutes more than a quarter of global GDP and more than 16% of global trade and about 30% of the land area and 44% of the world's population and more than 40% of the world's energy production. Purpose: The study is aimed at knowing the formation of the BRICS bloc as an emerging economic force within its economic dimensions, showing the international economic system of the BRICS countries and their ability to confront international economic institutions, and analyzing the economic indicators of each member country to know the economic size of each country. Theoretical framework: the study has relied on the deductive approach starting from real constants in collecting data and facts, as well as adopting the descriptive analytical method in studying the international economic system and the economic components of the BRICS countries within its economic dimensions.  Design/methodology/approach: it is proved that the BRICS contingent reserve arrangements to protect against global liquidity pressures, which include currency issues, have affected the members’ national currencies negatively due to global financial pressures. The economy is unstable and needs these potential reserves. The problem of the study emerges from certain questions including how strong the international economic system for the BRICS countries is and whether these countries were able to overcome global economic crises within their economic dimensions. Research,  Practical  &  Social implications: The study hypothesized that the BRICS countries have tremendous economic power as a result of building their international financial system, which they established, which enabled them to overcome the global financial crisis, unlike most countries in the world that were under the brunt of this crisis, and this is a clear indication of the success of this bloc and prove its hypothesis. In connection with the value of the study, it reflects that the BRICS countries occupy an important position in the international economy as a rising economic power through their economic nature and strategic position, in addition to the great economic capabilities that these countries possess, and this was an invitation to establish this bloc, which is a successful economic step in the face of international economic financial institutions. Finding: The most prominent findings of the research are that the presence of China in this bloc added a powerful and insignificant force to it as a result of its economic strength, which is the second largest economy in the world, and the economic strength of the BRICS bloc has led to increased economic development and the formation of a strong economic union that faces all the challenges that the bloc is exposed to

International Economic Institutions: Different Tasks And Risks of Repercussions at the Global Level

Purpose: International economic institutions occupy a great position at the level of global economies by providing great financial support to member countries. These institutions also seek to study their position at the international level and the extent of their capabilities to confront the crises that afflict developed and developing countries, as they have contributed to addressing the crises faced by the countries of the world. Since its inception and the repercussions and potential risks that threaten its economic stability. The study aims to achieve several goals, most notably studying the concept of international economic institutions and their implications for international economies, knowing the tasks of the International Monetary Fund and the World Bank regarding loan policies, and clarifying the implications and risks of loans provided by the Fund and the World Bank on the reality of global economies.   Theoretical framework: To approve the hypothesis of the study and achieve its aims, a deductive approach is adopted starting from realistic constants in collecting data and facts, as well as adopting the descriptive analytical method in the study of international financial institutions.   Design/methodology/approach: The impact of the chaos witnessed by the First and Second World Wars prompted the international financial institutions to assume the responsibility of managing the international monetary system and ensuring global economic stability through the application of policies to achieve this and address the deficit in the balance of payments of the member states of these institutions.   Findings: The study hypothesized that despite the repercussions and risks of wars on developing and developed countries, the international financial institutions represented by the IMF and the world bank were able, through their tasks, to offer packages of loans to fill part of the deficit that these countries were exposed to, which enabled the countries to finance its economic projects.   Research, Practical  &  Social implications: The most prominent finding of the study is that what distinguishes the work of the international monetary fund from the world bank is the duration of time, as the fund provides short-term loans, unlike the world bank, which deals with long-term loans. Regarding the lending policy, despite the high-interest rates imposed on loans by international economic institutions, they are linked to structural measures that constitute an obstacle to the lending country.   Originality/value: The problem of the study lies in the fact that most countries of the world, whether developed or developing, are exposed to many economic problems as a result of their lack of international financing needs to confront the crises they are exposed to, forcing them to resort to international financial institutions to fill the deficit

Design of a microwave based mobile thermo-chemical unit for biomedical waste treatment

Biomedical waste (BMW) contains pathogenic microorganisms that may severely harm the community and environment. Due to the Covid pandemic-2019, isolated wards at health care units and even due to the home treated patients; vast quantities of BMW are generated. Covid-19 converts even ordinary waste such as gloves, testing kits, and personal protective equipment into high-risk BMW. The appropriate disposal of such waste involves safety, affordability, and efficacy; hence can be considered a complex issue. A solution proposed in this article is an OSBMWTU (on-site biomedical waste treatment unit) by using microwave radiation. The possibility of enhancing the thermal effect of microwave radiation by using chemical additives was tested. The proposed machine reduces waste volume, inactivates microorganisms, and disposes BMW on-site. Findings suggest that adding butter spray to microwave radiation enhances thermal effectiveness by 43%, increasing treatment temperature while minimizing time, power, and running costs. The proposed machine will work automatically after filling the BMW, thus, minimizing the human involvement. It prevents bio-hazardous waste accumulation and decreases its volume by up to 80%. The designed machine is characterized by safety, low cost, and small dimensions. A machine that can handle 72 kg BMW/day can be set up on-site in an area of 1.5 m2. The suggestion of the proposed machine as a BMW management and treatment system will reduce environmental pollution due to BMW during COVID-19 and even after the pandemic