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Additive manufacturing (AM) is used for highly complex structures that can be stable and extremely light weight. AM also enables a design-driven manufacturing process where production is determined by design. Fused deposition modelling (FDM) is one of the mainly used AM technique. It is more easily accessible technique than others and also has advantages like less time consuming, usage with broad range of materials and lower costs. It is also referred to as 3D printing in which objects are produced layer by layer from a CAD model by depositing a thermoplastic filament. Mechanical properties like tensile strength and hardness plays a vital impact when various process parameters are varied on printed parts for different application. Experimental investigation on the FDM printed parts using acrylonitrile butadiene styrene (ABS) material has been carried out by varying the three process parameters namely Infill density, Infill pattern and Layer thickness. Tensile strength and hardness are utilized as response parameters. Experiments are considered by means of central composite design (CCD) of response surface methodology (RSM). The optimization has been carried out by desirability analysis. The study reveals that that infill density and layer thickness is most significant factor.

The main purpose of the proposed system is to design a low-cost universal PV battery charger for electric vehicle application. The proposed system is integrated with a slope-compensated current controller which controls the charging current that corresponds to maximum power point of the PV module. As an interface converter, the proposed system consists of a buck converter to control the flow of the charging current and to find out the reference current Iref from the PV array at MPP. The battery control circuit is implemented by measuring the state of charge (SOC) of the battery, and an LCD display has been used to monitor the battery parameters. This proposed system acts as a smart and efficient PV battery charger for e-vehicles.

Biological hands work by picking up signals from muscle and is controlled by tensing the same muscle. This paper proposes a lightweight bionic hand built based on this concept and considering the high performance and low-cost factors. Layer manufacturing (LM) also known as 3D printing is trending manufacturing set up considering zero material waste and generating ideas into 3D geometrical model. The layers are produced one by one by lowering the material deposition platform and built as per a 3D CAD model. Layered manufacturing process is open to handle wide variety of materials such as polymers, metals, composites. In this research study, a lightweight robotic hand has been modeled using 3D CAD software and the CAD model is generated using a 3D printer. The hand is then interfaced with Arduino, where the sensors and actuators are then programmed for the individual finger movement. The individual performance of each finger is analyzed for both linear and rotational movement by getting signals from the flex sensor. Furthermore, the load carrying capacity of the hand is also analyzed. The force required to pick or lift the object by using this artificial arm is determined which is solely determined by the capacity of the servomotor being used.

The use of quadratic gate delay models and arrival times results in improved accuracies for a parameterized block-based statistical static timing analysis (SSTA). However, the computational complexity is significantly higher. As an alternative to this, we propose a canonical model based on skew-normal random variables (SN model). This model is derived from the quadratic canonical models and can consider the skewness in the gate delay distribution as well as the nonlinearity of the MAX operation. Based on conditional expectations, we derive the analytical expressions for the moments of the MAX operator and the tightness probability that can be used along with the SN canonical models. The computational complexity for both timing and criticality analysis is comparable with SSTA using linear models. There is a two to three orders of magnitude improvement in the run time as compared with the quadratic models. Results on ISCAS benchmarks show that the SN models have a lower variance error than the quadratic model, but the error in the third moment is comparable with that of the semiquadratic model.

In this article, we derive a simple and accurate expression for the change in timing yield due to a change in the gate delay distribution. It is based on analytical bounds that we have derived for the moments of the circuit and path delay. Based on this, we propose computationally efficient algorithms for (1) discrete gate sizing and (2) simultaneous gate sizing and threshold voltage ( V T ) assignment so that the circuit meets a timing yield specification under parameter variations. The use of this analytical yield gradient within a gradient-based timing yield optimization algorithm results in a significant improvement in the runtime as compared to the numerical method, while achieving the same final yield. It also allows us to explore a larger search space in each iteration more efficiently, which is required in the case of simultaneous resizing and V T assignment. We also propose heuristics for resizing/changing the V T of multiple gates in each iteration. This makes it possible to optimize the timing yield for large circuits. Results on ITC ’99 benchmarks show that the proposed multinode resizing algorithm results in a significant improvement in the runtime with a marginal average area penalty and no cost to the final yield achieved.

This paper presents the Vector control of SVPWM inverter fed Induction motor drive. The scalar v/f method gives satisfactory performance only during steady state not under transient conditions. This major disadvantage can be overcome by vector control method. The vector control provides high dynamic performance for speed and torque controlled AC drives. In order to understand and analyze the vector control of induction motors, the dynamic model is necessary. As a first step, IM is modeled in an arbitrary reference frame. Next, Space Vector PWM technique is implemented. And the performance of vector control of SVPWM fed induction motor drive has been analyzed in the MATLAB/Simulink environment.

This paper presents the design and analysis of Hybrid DC-DC Step-up converter in continuous conduction mode(CCM). The proposed Hybrid DC-DC boost converter consists of conventional boost converter which incorporates switched capacitor cell-UP1. It provides high DC-DC voltage conversion(60V-380V) and eradicates the complexity in conventional boost converter while operating in high duty ratio [2]. A small structure changes has to be made to convert conventional boost converter into a hybrid switched-cell-based boost converter. There are six different types of switch cells, of all UP1 cell has been used in this converter. The output results are validated with the help of simulation using MATLAB/SIMULINK. The performance, such as dc gain, voltage and current stresses on the actives witch, currents through the inductors are shown in output wave forms.

Statistical timing yield optimization algorithms require computation of yield-gradient for gate resizing in every iteration. Numerical yield-gradients account for the effects of fan-in and fan-out gates, but are computationally expensive. In this paper, we formulate a more accurate analytical expression for the yield-gradient (termed effective yield-gradient) that includes these effects. Based on the statistical properties of the path delay variations, we derive a simplified expression for the effective yield gradient that is accurate and results in an improvement in the run-time. Using these simplified expressions, we also propose an algorithm for resizing multiple gates in an iteration. Results on ITC99 and ISCAS85 benchmarks show that the proposed multi-node resizing algorithm results in 83% improvement in the runtime with an average area penalty of 3% and no cost to the final yield achieved.

SM control is a kind of nonlinear control which has been developed predominantly for the control of variable structure systems. Being a control method it has a high degree of flexibility in its design choices, the SM control method is relatively easy to implement as compared to other nonlinear control methods. The design procedure and mathematical modeling for the Boost Converter has been interpreted. In this paper the sliding coefficient for the controller has been selected based on fulfilling the hitting, existence and stability conditions. The controller equations for the selected bandwidth have been derived and modeled using MATLAB/SIMULINK.

This paper focuses on power loss analysis of non-isolated hard switching boost converter and quasi resonant ZVS (zero voltage switching) soft switching boost converter for various switching frequency in Power Conditioning System (PCS). Efficiency comparison and power losses of passive components are calculated for various switching frequency. The design and performance of the system is verified through simulation using PSPICE software.

This paper deals with an active input power factor correction with single phase bridge rectifier fed boost converter topology using hysteresis current control technique. The duty ratio is obtained by the comparison of a inductor current and a ramp carrier waveform which is associated with hysteresis controller in each switching period. In this work MATLAB/Simulink power system toolbox is used to simulate the proposed system. Simulation results are presented and the improvement in the supply current is illustrated in this work. As the result, the input current waveform is fashioned to strictly sinusoidal and in-phase with supply voltage, entailing high power factor.

The statistical nature of gate delays in current day technologies necessitates the use of measures, such as path criticality and node/edge criticality for timing optimization. Node criticalities are typically computed using the complementary path delay. An alternative approach to compute the criticality using the circuit delay has been recently proposed. In this paper, we discuss in detail, the use of circuit delay to compute node criticalities and show that the criticality thus found is not equal to the conventional measure found using complementary path delay. However, there is a monotonic relationship between them and the two measures can be used interchangeably. We derive new bounds for the global criticality and propose a pruning algorithm based on these bounds to improve the accuracy and speed of computation. The use of this pruning technique results in a significant speedup in criticality computations. We obtain an order of magnitude average speedup for ISCAS benchmarks.

This paper deals with modeling and dynamic simulation of PMBLDCM drives using MATLAB and its toolbox Simulink. Mathematical model of whole system which incorporates BLDC Motor, inverter, current controller and speed/torque controller is used for the proposed model of PMBLDCM drives. The current, back emf and torque equations are used to build the mathematical model of BLDC Motor. Inverter is modeled with the help of switching function concept instead of using actual switching device. PI controller is utilized for speed/torque control of PMBLDCM drives. Hysteresis controller is employed for current control of PMBLDCM drives. With the aid of the developed model, the Steady and Transient-state characteristics of speed and torque in addition to voltages and currents of inverter components can be effectively examined and analyzed. This proposed model can be projected to trouble-free design tool for the development of PMBLDCM drives.

This paper presents the comparative evaluation of the performance of two most popular control strategies for induction motor drives: Classical DTC and SVPWM-DTC (in all four quadrants of operation). Though Classical DTC is a simple method, it suffers from the disadvantages like variable & high switching frequency and high torque & current ripples in steady state. SVPWM-DTC as a control strategy overcomes most the above mentioned drawbacks. The MATLAB / SIMULINK model of both Classical & SVPWM-DTC based induction motor drives are simulated in all four quadrants of operation (forward motoring, reverse motoring, braking and regenerative braking) and the simulations results are analyzed. The results make obvious that although both the schemes can be implemented in all the four quadrants, SVPWM has DTC has better steady state torque response than Classical DTC.

Due to the statistical nature of gate delays in current day technologies, measures such as path criticality and node/edge criticality are required for timing optimization. Node criticalities are usually computed using the complementary path delay. In order to speed up computations, it has been recently proposed that the circuit delay be used instead. In this paper, we show that there is a monotonic relationship between the node criticalities computed using the circuit delay and the complementary delay. They are not equal, but they can be used interchangeably. We discuss the sources of error in this computation and propose methods for more accurate computations. We also introduce a measure that is very easy to compute and is an approximate indicator of criticality. Since it is easy to compute, it can also be used effectively for pruning the number of edges involved in criticality computations thus improving the speed of criticality computations. The speedup obtained can be as large as an order of magnitude for some of larger circuits in the ISCAS benchmarks.

This paper deals with Four Quadrant Operation of Direct Torque Control (DTC) - Space Vector Pulse Width Modulation (SVPWM) based 3-phase Induction Motor Drive using MATLAB and its toolbox SIMULINK. The Classical Direct Torque Control of VSI fed Induction Motor is implemented with the help of Hysteresis Band (HB) controllers (one for flux control and other for torque control), a voltage source inverter and a switching table. Classical DTC has the disadvantages like variable & high switching frequency and high torque and current ripples in steady state. To overcome these difficulties SVPWM is employed in the proposed model. With aid of the developed model, the steady and transient-state characteristics of current, speed and torque of three phase induction motor can be effectively examined and analyzed. This proposed model can be projected as a trouble-free design tool for the development of three phase induction motor drives.

In this paper, a novel approach for phoneme classification using binary feature vector and correlation based classifier is proposed. The input speech segmentation is carried out using the Average Level Crossing Rate (ALCR) information. A 513-point binary feature vector is generated for each of the phoneme segment detected by ALCR boundaries. The phoneme recognition is based on the uniqueness of the frequency content of each of the phoneme. Instead of using a Hidden Markov Model, Artificial Neural Network or Support Vector Machine based classifier, a simple correlation classifier using the correlation between feature vectors and the set of feature vectors generated with training data is employed. The proposed approach is simpler and requires lesser computational resources when compared with other pattern classification techniques. The performance of proposed phoneme recognition system has been evaluated using real-time speech input and the recognition performance of the proposed phoneme recognition system is satisfactory.