Using a Karnaugh-map perspective, this paper investigates the definitions, exposes the properties, introduces new computational procedures, and discovers interrelationships between the Walsh spectrum and the real transform of a switching function. Appropriate Karnaugh maps explain the computation of Walsh spectrum as defined in cryptology. An alternative definition of this spectrum adopted in digital design and related areas is then presented together with procedures for its matrix computation. Then, the real transform of a switching function is defined as a real function of real arguments. This definition is clearly distinguished from similar ones such as the multi-linear form or the arithmetic transform. The real transform is visualized in terms of a particular version of the Karnaugh map called the probability map. Karnaugh maps are also used to demonstrate the computation of the spectral coefficients adopted in digital design as the weight of the switching function and weights of its subfunctions or restrictions. These maps match the earlier ones for the spectrum used in cryptology. Novel relations between the Walsh spectrum and the real transform are utilized in formulating two simplified methods for computing the spectrum via the real transform with some aid offered by Karnaugh maps. Finally, a solution is offered for the inverse problem of computing the real transform in terms of the Walsh spectrum.

Structural design of RC buildings has been going through a transition from allowable stress design approach (ASD) to the ultimate strength design approach (USD) leading to the present performance based design philosophy. PBD ensures that the members and structure as a whole reach a desired demand level and includes service, strength and capacity requirements. In the presented study a nonlinear analysis and design has been conducted on an intermediate rise RC building considering all seismic zones as specified by Unified Building Code in order to compare the USD and PBD approaches. Furthermore a comparison of different shear wall modeling techniques is presented along with modification to design methodology to make the structural design more economical. For the USD, UBC97 and for PBD, ATC-40, FEMA-273 and FEMA-356 guidelines are used. The presented results reveal that the USD approach is unable to predict the soft story mechanism and shear failure governed the final failure in all seismic zones, whereas the flexural design was found to be adequate as inelastic deformations remained within the acceptable limits. However, capacity analyses revealed a non uniform damage throughout the building in contrast to PBD approach.

This research work presents a reconfiguration experience of a real case power distribution networks aiming to minimize the active power losses and consequently to improve the voltage profile of the overall grid. The grid is modelled as a mixed integer linear programming problem whose objective function is to minimize the active power losses subject to technical constraints, which are: the power balance in each node of the power grid, the capacity limits of the lines and the substations, maintaining the radial operation of the network. The model results are the open branches on each circuit. The technique has been successfully applied to a large power distribution networks with 2344 nodes at a 13.8kV level, located in real city resulting in an 8% and 6% losses reduction in terms of active power losses and energy respectively, and a substantial improvement in the voltage profiles regarding the current state of grid with very acceptable convergence times.

In this paper, low-dimensional nanostructures are used to enhance the power conversion efficiency of solar cell (SC). Quantum dots intermediate band (QDIB) is used for this purpose. This idea maintains a large open-circuit voltage and increases the produced photocurrent. The balance efficiency analysis of SC is performed by using the Blackbody spectrum as well as more realistic spectra at AM0 and AM1.5. A comparison between conventional solar cell (CSC), intermediate band solar cell (IBSC), and quantum dots intermediate band solar cell (QDIBSC) is performed. The Schrödinger equation is used to calculate the sub-bandgap energy transition in the quantum dots (QDs) by using the effective mass of charge carriers. Also, the influences of sub-bandgap energy transition, the location of intermediate band (IB), the QDs width size (QDW), and the barrier thickness (BT) between dots are studied on the power conversion efficiency of SC. The results show that the efficiency of SC is significantly improved when it is based on nanostructures.