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This paper describes a generalized method to develop steady state model (SSM) of different electric motors comprising electric equivalent circuit (EEC) and the torque equation. In most of the books on electric motors, EEC is used to explain operation and performance characteristics of motors, but the development of these EECs is not explained convincingly. This work overcomes this shortcoming by specifically...
In this paper DC-AC differential inverters, which are capable of stepping-up the DC voltage in a single-stage, are studied. Due to the reduced number of devices, they are compact, efficient and low cost. Due to their unique characteristics, they can be used in many applications such as PV, UPS and fuel-cell. This paper introduces a new control method which utilizes a different set of voltage references...
A robust passive auxiliary circuit is proposed to maintain ZVS operation of full bridge converters. In steady-state operation for the same auxiliary peak current level, a minimum of 20 percent reduction in rms current is achieved compared with single-inductor auxiliary circuit. This results in the same ZVS functionality with reduced conduction losses. Experimental results are in agreement with the...
This paper discusses a control technique that allows for controlling the bi-directional flow of active and reactive power using the DQ theory. Traditionally, this theory is used for three phase systems. Its use in single-phase converters presents a challenge due to the lack of degrees of freedom required for orthogonal systems. In this paper, a few methods for orthogonal system generation are presented...
A wrist watch based system, which can measure electrocardiogram (ECG) and photoplethysmogram (PPG), is presented in this work. By using both ECG and PPG we also measure pulse transit time (PTT), which studies show to correlate well with blood pressure (BP). The system is also capable of monitoring heart rate using either ECG or PPG and can monitor blood oxygenation by easily replacing the PPG sensors...
This paper investigates on the development of advanced three phase Permanent Magnet Brushless DC motor (PMBLDC) drive meant for future aerospace applications. Mathematical modeling of a drive is necessary for realizing the dynamic behaviour so it is developed and is presented here. The conversion of three phase system to the two phase reference frame using Park's. Clarke's transformations, advanced...
This paper presents a control method to improve the efficiency and dynamic response of wind energy control systems (WECS) that use a permanent magnet synchronous generator (PMSG) operating under a wide input and load range. An adaptive passivity-based nonlinear controller (APBC) is developed and tested. This controller is designed to overcome the limitations of conventional dq-control methods, which...
In this paper, diagnosis of diabetes using soft computing is presented. This research work is based on the fuzzy if-then rules and tuning of the parameters by neural network. A variational method for determining, globally optimal learning parameters and learning rules for on-line gradient descent training has been proposed in the paper. Neurofuzzy system is put in the framework to facilitate learning...
This paper presents a pattern synthesis method based on two powerful tools of the Evolutionary computing i.e Differential Evolution, Invasive weed optimization and Firefly technique, to provide a significant side lobe reduction. The Antenna elements are embedded on a hemispherical array that leads to one of the geometry of a conformal shape. The array elements are excited with uniform amplitude excitation...
Various control applications such as aerospace vehicles and automotive control systems can benefit from lower weight and cost. Replacing wired feedback control with wireless sensor and actuator networks (WiSAN) offers attractive features by improving upon the weight and cost problems, while posing new challenges due to the delayed noisy feedback links. Addressing these challenges requires modeling...
Performance of the recognition free approaches for document retrieval, heavily depends on the exact or approximate matching of images (in some feature space) to retrieve documents containing the same word. However, the harder problem in information retrieval is to effectively bring semantics into the retrieval pipeline. This is further challenging when the matching is based on visual features. In...
In this paper, a user behavior based solder joint reliability modeling approach has been proposed to estimate the design and test requirements for the second level interconnect (SLI) reliability prediction. This approach uses a numerical tool to integrate solder joint creep damage during the actual use condition that was collected from a large user sample size. The resultant damage per time period...
As supply voltage is reduced, a power constrained test clock can be sped up in spite of the increased delay of the circuit. However, a large reduction in voltage makes the operation structurally constrained, requiring the clock to slow down. We determine an optimum supply voltage that allows fastest clock speed for a given power limit. Examples show that the test time can be reduced by as much as...
Active contour methods for image segmentation allow a contour to deform iteratively to partition an image into various regions. Active contours are often implemented with level set methods because of their power and versatility. The primary drawback of level set methods is that, they are slow to compute. In this paper, we discussed the sparse field method (SFM) proposed by Whitaker that allows one...
Due to the recently changed environmental requirements that affect manufacturing operations and transportation systems; growing attention is given to the development of environment management strategies for supply chains. The reverse supply chain involves the movement of used products from the customer to the upstream supply chain for possible recycling and reuses. It has been found that reverse supply...
It has been noted that the models typically used to represent inverters in simulation and design tools at the present are inadequate because they do not capture the variations in electrical efficiency over the full range of operating conditions. Data to develop more detailed models have been scarce in the past, but are now increasingly available from multiple sources, therefore it is time to rectify...
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