Advanced Materials Research Vols. 622-623

Abstract: Electrical insulators of the Provincial Electricity Authority (PEA) of medium system are mostly porcelain insulator types that consist of pin type, line post, and pin post insulators. The distribution lines will be polluted by industrial contaminants, salt fog or natural dust. Experience shows that pollution flashover is one of the main natural calamities harming and affecting the voltage stability and reliability of distribution system. This paper compares the test results obtained from the artificial pollution tests according to IEC 60507 in the chamber for tests with standard porcelain insulators consist, pin post, line post and pin type insulators of medium system under same test conditions. The salt fog test results indicate that the pollution flashover performance of pin type insulator is less than to 50 percent of wet power frequency withstand voltage at equivalent salt deposit density (ESDD) = 0.5 mg/cm² and the leakage current (LC) of pin type insulator increased to 11.4 mA at ESDD = 0.5 mg/cm² at nominal voltage. In the experiment indicate that AC pollution flashover performance of pin post insulator has better than line post and pin type insulators in the serious pollution area. This data will be useful to be guideline for solving problems and reducing power loss from leakage current on the surface of the insulators as a result of surface dirt and pollution. Moreover, it will be useful to select or design suitable insulators for using in places with salt conditions, high rainfall, high wind speeds and high humidity.

Abstract: The elliptic curve crypto-system (ECC) performs two levels of computations, lower point operations, and upper scalar multiplication levels. The use of usual serial design and affine coordinates to apply ECC computations increases the time delay and weaken the security of the crypto-system against simple power attack (SPA). This work combines the inherited parallelism in both computation levels for GF (p) Montgomery ECC to improve performance and enhance the immunity of the ECC against SPA. Moreover, projective coordinates were used to apply ECC operations to eliminate the time-consuming inversion operation. In order to increase the speed even further, this paper proposes to use known NAF algorithm for scalar multiplication, as well as Montgomery multiplier to perform multiplication operations. Hardware implementations with target FPGA for GF (p) Montgomery ECC are also presented. The best performance level was achieved when parallelizing Montgomery ECC computations to eight parallel multipliers (PM) using homogeneous coordinates. Such strategy, although it requires extra resources, is worth considering due to its attractive security and performance conclusions.

Abstract: For ensuring the life and security of ship, electric fields protection has been used for a long time. The common method of electric fields protection is equipping compensatory anode on the ship and adding a current which can been controlled to it. The electric fields is different when the number of compensatory anode is different. This paper establish a mathematical model of a ship with compensatory, and then analyze the ship’s electric fields when the number of compensatory anode is different. and attain how compensatory anode number affect ship’s electric fields protection.

Abstract: The Euler-Lagrange (EL) model of the three-phase induction motor is set up based on the mathematical model of the three-phase induction motor in the two-phase static coordinate. The passivity and dissipativity of the three-phase induction motor are studied by EL model. Based on the passivity of induction motor, the passivity-based controller of system is designed with the method of damping injection under the conditions of the stator flux oriented.The system simulation model of the three-phase induction motor is established under MATLAB/Simulink environment. The Simulation results show that the passivity-based controller designed with the method of damping injection under the conditions of the stator flux orientedis feasible.

Abstract: This paper presents a curriculum design of a course about reliability of circuits and systems. Contents in the learning modules include failure mechanisms of electronics, reliability for electronic components and circuit systems and simulation for circuit reliability. Through learning modules, students can learn concepts about reliability in circuits and systems, as well as develop awareness to design a reliable circuit system.

Abstract: Using ASP.NET as a development tool is in order to develop this small trading company customer management system. This article appeared in recent years by trading on the domestic management system software analysis, combined with work experience, according to the software engineering approach to the small trading company customer management system, a system analysis, overall design, detailed design. Uses the popular client / server mode, select the database performance SQL, using efficient tools VISUAL STUDIO 2005, to complete the small trading company customer management system software design and development.

Abstract: This paper analyzes the class, class members, interface and interface members in C# language. Then uses an example based on inheritance in the class and interface to illustrate their use in the actual project. It helps the program code to write, read, maintain and modify that under correctly understanding and definition of class and interface.

Abstract: Open source software systems are becoming increasingly important these days and will grow stronger in the future. In order to gain more information about them, their structure characteristics and behavior characteristics need to be measured. This paper tests scale free characteristics on open source real-world software empirically. More specially, this paper checks whether Chidamber and Kemerer metrics suite follows power law or not through three versions of Weka. Our empirical results showed that the features of complex networks didn’t exist in Weka.