Visually impaired people face difficulties in interacting and gaining full advantage of computers. Recently, and with the fast evolution in technology, researchers proposed to give the blinds the ability to take advan...Visually impaired people face difficulties in interacting and gaining full advantage of computers. Recently, and with the fast evolution in technology, researchers proposed to give the blinds the ability to take advantage of these advancements. Accordingly, designers and engineers started working on projects that relate input and output devices to the computers in order for the blind individual to have full control of the hi-tech machines. However, investments in these kinds of hardware presented complexity in the design, in addition to the high cost imposed by the devices used. The project’s objective is to design and develop a Multi-Lingual Braille System Output Device for the visually impaired individuals that enable them to access and read texts from a computer. The device acquires both English or Arabic texts and displays them using controlled piezoelectric Braille cells. It also has the ability to produce a sound that matches the displayed characters. The control of the cells is done via Programmable Interface Controller (PIC) microcontroller. The interaction between the device and the computer is done through the Universal Serial Bus (USB). C# is the language used to write the program responsible for controlling this interaction. The continuous development of such devices is essential for the visually impaired to keep up with the technological advancements. The main advantages of this system are its low cost, the added multi-lingual, and the audio features. In addition, many features can be added so as to satisfy the users’ needs, such as adding new languages and Grade 2 Braille System.展开更多
Power factor (PF) is simply an expression of energy efficiency, which is always expressed in terms of percentage. Technically, PF is a ratio of real power in Kilowatts to the apparent power, which is always expressed ...Power factor (PF) is simply an expression of energy efficiency, which is always expressed in terms of percentage. Technically, PF is a ratio of real power in Kilowatts to the apparent power, which is always expressed in kilovolts amperes. In AC power analysis, power is always expressed in three ways, the real power (<i></span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;"></i>), reactive power (<i></span><i><span style="font-family:Verdana;">Q</span></i><span style="font-family:Verdana;"></i>), and the apparent power (<i></span><i><span style="font-family:Verdana;">S</span></i><span style="font-family:Verdana;"></i>). The real power is the work useful power, while the reactive power is the wasted power in the 3-phase AC system, and the apparent power is the vectorial sum of the two powers. The increase of reactive power will reduce the presence of real power, thus making the power to be more expensive. In this paper, we will analyze the importance of improving the power factor by applying a bank of capacitors to a case study in Lebanon. Analysis of the economic improvement in the application of power factor correction is carried out. The result shows a reduction of 12 percent in the total cost.展开更多
Mobile ad-hoc networks are wireless self-organized networks in which mobile nodes can connect directly to each other. This fact makes such networks highly susceptible to security risks and threats, as malicious nodes ...Mobile ad-hoc networks are wireless self-organized networks in which mobile nodes can connect directly to each other. This fact makes such networks highly susceptible to security risks and threats, as malicious nodes can easily disguise as new trusted nodes and start attacking the network after a certain period of time. Hence, the security of data transmission in MANET has been a hot topic in the past years. Several research works attempted to detect and stop various attacks on MANET nodes and packets. This paper presents an efficient mechanism for secure data dissemination in MANETs. Our approach is based on the identity based cryptography and Message Authentication Code (MAC). The proposed security mechanism prevents malicious nodes from tampering or replaying intermediate packets by means of signing and encrypting the packet at each intermediate trusted node. We tested the efficiency of our system using the ns2 simulator by comparing it to a similar security mechanism. The simulations illustrate that our approach obtains many advantages over other existing approaches for secure data dissemination in MANETs.展开更多
In this study,we investigate the(2+1)-dimensional Korteweg-De Vries(KdV)equation with the extension of time-dependent coefficients.A symbolic computational method,the simplified Hirota’s method,and a long-wave method...In this study,we investigate the(2+1)-dimensional Korteweg-De Vries(KdV)equation with the extension of time-dependent coefficients.A symbolic computational method,the simplified Hirota’s method,and a long-wave method are utilized to create various exact solutions to the suggested equation.The symbolic computational method is applied to create the Lump solutions and periodic lump waves.Hirota’s method and a long-wave method are implemented to explore single-,double-and triple-M-lump waves,and interaction physical phenomena such as an interaction of single-M-lump with one-,twosoliton solutions,as well as a collision of double-M-lump with single-soliton waves.Furthermore,the simplified Hirota’s method is employed to explore complex multi-soliton solutions.To realize dynamics,the gained solutions are drawn via utilizing different arbitrary variable coefficients.展开更多
文摘Visually impaired people face difficulties in interacting and gaining full advantage of computers. Recently, and with the fast evolution in technology, researchers proposed to give the blinds the ability to take advantage of these advancements. Accordingly, designers and engineers started working on projects that relate input and output devices to the computers in order for the blind individual to have full control of the hi-tech machines. However, investments in these kinds of hardware presented complexity in the design, in addition to the high cost imposed by the devices used. The project’s objective is to design and develop a Multi-Lingual Braille System Output Device for the visually impaired individuals that enable them to access and read texts from a computer. The device acquires both English or Arabic texts and displays them using controlled piezoelectric Braille cells. It also has the ability to produce a sound that matches the displayed characters. The control of the cells is done via Programmable Interface Controller (PIC) microcontroller. The interaction between the device and the computer is done through the Universal Serial Bus (USB). C# is the language used to write the program responsible for controlling this interaction. The continuous development of such devices is essential for the visually impaired to keep up with the technological advancements. The main advantages of this system are its low cost, the added multi-lingual, and the audio features. In addition, many features can be added so as to satisfy the users’ needs, such as adding new languages and Grade 2 Braille System.
文摘Power factor (PF) is simply an expression of energy efficiency, which is always expressed in terms of percentage. Technically, PF is a ratio of real power in Kilowatts to the apparent power, which is always expressed in kilovolts amperes. In AC power analysis, power is always expressed in three ways, the real power (<i></span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;"></i>), reactive power (<i></span><i><span style="font-family:Verdana;">Q</span></i><span style="font-family:Verdana;"></i>), and the apparent power (<i></span><i><span style="font-family:Verdana;">S</span></i><span style="font-family:Verdana;"></i>). The real power is the work useful power, while the reactive power is the wasted power in the 3-phase AC system, and the apparent power is the vectorial sum of the two powers. The increase of reactive power will reduce the presence of real power, thus making the power to be more expensive. In this paper, we will analyze the importance of improving the power factor by applying a bank of capacitors to a case study in Lebanon. Analysis of the economic improvement in the application of power factor correction is carried out. The result shows a reduction of 12 percent in the total cost.
文摘Mobile ad-hoc networks are wireless self-organized networks in which mobile nodes can connect directly to each other. This fact makes such networks highly susceptible to security risks and threats, as malicious nodes can easily disguise as new trusted nodes and start attacking the network after a certain period of time. Hence, the security of data transmission in MANET has been a hot topic in the past years. Several research works attempted to detect and stop various attacks on MANET nodes and packets. This paper presents an efficient mechanism for secure data dissemination in MANETs. Our approach is based on the identity based cryptography and Message Authentication Code (MAC). The proposed security mechanism prevents malicious nodes from tampering or replaying intermediate packets by means of signing and encrypting the packet at each intermediate trusted node. We tested the efficiency of our system using the ns2 simulator by comparing it to a similar security mechanism. The simulations illustrate that our approach obtains many advantages over other existing approaches for secure data dissemination in MANETs.
文摘In this study,we investigate the(2+1)-dimensional Korteweg-De Vries(KdV)equation with the extension of time-dependent coefficients.A symbolic computational method,the simplified Hirota’s method,and a long-wave method are utilized to create various exact solutions to the suggested equation.The symbolic computational method is applied to create the Lump solutions and periodic lump waves.Hirota’s method and a long-wave method are implemented to explore single-,double-and triple-M-lump waves,and interaction physical phenomena such as an interaction of single-M-lump with one-,twosoliton solutions,as well as a collision of double-M-lump with single-soliton waves.Furthermore,the simplified Hirota’s method is employed to explore complex multi-soliton solutions.To realize dynamics,the gained solutions are drawn via utilizing different arbitrary variable coefficients.