Abstract COEP-Microgrid, a project by the students of College of Engineering Pune aims at establishing a microgrid in the college campus serving as a living laboratory for research and development of novel grid technologies. Proposed microgrid has an AC-bus and DC-bus, interconnected together with a tie line DC -AC converter. In grid connected mode AC bus of microgrid is synchronized with... COEP-Microgrid, a project by the students of College of Engineering Pune aims at establishing a microgrid in the college campus serving as a living laboratory for research and development of novel grid technologies. Proposed microgrid has an AC-bus and DC-bus, interconnected together with a tie line DC -AC converter. In grid connected mode AC bus of microgrid is synchronized with utility grid. Synchronization with utility grid requires grid and AC bus to have synchronism in frequency, phase sequence and voltage. Power flow requires phase difference between grid and AC bus. Control System is required to effectively regulate power flow between the grid and AC bus. The grid synchronizing control system is composed of frequency and phase control for regulated power flow and voltage control system for reduction of reactive power flow. The control system involves automatic active power flow control. It takes the feedback of DC link Capacitor and changes the power angle accordingly. Control system incorporating voltage, phase and power control was developed for grid-tie inverter. This paper discusses the design, simulation and practical implementation of control system described in various microgrid scenarios. Read More Read Less

Abstract Using a combined approach, the effect of air gap tuning on the resonant frequency and radiation field of an equitriangular microstrip antenna is presented in this paper. An equilateral triangular patch is implemented on an isotropic dielectric with an air gap inserted under this one in order to estimate the influence of an air gap on radiation antenna’s characteristics. The problem... Using a combined approach, the effect of air gap tuning on the resonant frequency and radiation field of an equitriangular microstrip antenna is presented in this paper. An equilateral triangular patch is implemented on an isotropic dielectric with an air gap inserted under this one in order to estimate the influence of an air gap on radiation antenna’s characteristics. The problem is analysed in spectral domain using the moment method and an electric field integral equation combined with a mathematical approach. However, the dyadic Green’s functions corresponding to the proposed structure are developed and the Fourier transform of basis current components are calculated mathematically using “the reference element” method. A numerical result shows that the change in resonant frequency, bandwidth and radiation field of the antenna is due primarily to a small disturbance of the air gap thickness and consequently substrate’s equivalent permittivity. Read More Read Less

Abstract We propose an algorithm for generating mutant policies based on XACML Context Schema, known as Change Rule and Swap Rule Algorithm (CRSR). Compared to other testing techniques and tools for testing access control policies, where policy set or policy is evaluated first, our algorithm focuses on the rule and target of a policy set or policy. Our approach represents policy... We propose an algorithm for generating mutant policies based on XACML Context Schema, known as Change Rule and Swap Rule Algorithm (CRSR). Compared to other testing techniques and tools for testing access control policies, where policy set or policy is evaluated first, our algorithm focuses on the rule and target of a policy set or policy. Our approach represents policy as a vector of bits. A boolean variable 1 represents the applicability of a policy to a request and a boolean variable 0 represents the non-applicability of a policy to a request. Correct policy evaluates to 1: indicating that all the elements, attributes ID and their values are correct. This is done using the XACML Context Schema for a policy and request. We identify and extract the rule and target from the policy and generate request by applying the proposed algorithm. The rule and target are evaluated first on the assumption that policy set specifies what policies may be applicable to a request, while a policy specifies the rules that are required for a policy to be applicable to a request. Mutants generated based on XACML Context Schema for policies using the proposed algorithm is compared with mutants generated by using mutation testing where specific mutant operators are applied. Read More Read Less

Abstract We propose an algorithm for generating mutant policies based on XACML Context Schema, known as Change Rule and Swap Rule Algorithm (CRSR). Compared to other testing techniques and tools for testing access control policies, where policy set or policy is evaluated first, our algorithm focuses on the rule and target of a policy set or policy. Our approach represents policy... We propose an algorithm for generating mutant policies based on XACML Context Schema, known as Change Rule and Swap Rule Algorithm (CRSR). Compared to other testing techniques and tools for testing access control policies, where policy set or policy is evaluated first, our algorithm focuses on the rule and target of a policy set or policy. Our approach represents policy as a vector of bits. A boolean variable 1 represents the applicability of a policy to a request and a boolean variable 0 represents the non-applicability of a policy to a request. Correct policy evaluates to 1: indicating that all the elements, attributes ID and their values are correct. This is done using the XACML Context Schema for a policy and request. We identify and extract the rule and target from the policy and generate request by applying the proposed algorithm. The rule and target are evaluated first on the assumption that policy set specifies what policies may be applicable to a request, while a policy specifies the rules that are required for a policy to be applicable to a request. Mutants generated based on XACML Context Schema for policies using the proposed algorithm is compared with mutants generated by using mutation testing where specific mutant operators are applied. Read More Read Less