Robustness of group delay representations for noisy speech signals

This paper demonstrates the robustness of group delay based features to additive noise. First, we analytically show the robustness of group delay based representations. The analysis makes use of the fact that, for minimum-phase signals, the group delay function can be represented in terms of the cepstral coefficients of the log-magnitude spectrum. Such a representation results in the speech spectrum dominating over the noise spectrum, both at low and high SNRs. Further, we experimentally demonstrate the robustness of the representation on a voice activity detection (VAD) task, comparing a group delay based VAD algorithm with standard VAD methods as well as a magnitude-spectrum based method.     

Sizing Cracks in Power Plant Components Using Array Based Ultrasonic Techniques

New techniques developed using the array transducer, to image and size the bottom-surface and near-through-wall crack-like defects in thick carbon steel components are discussed. Three studies are reported here including (a) Optimal beam steering angle for focused and unfocused inspection using phased array method for bottom-surface crack sizing. (b) A front wall correction algorithm for sizing of near-through-wall crack-like defects. (c) A small aperture technique for sizing of near-through-wall crack-like defects. A Finite Difference Time Domain (FDTD) based simulation was used to study and verify the experimental observations. The application of time domain scheme relative arrival time technique (RATT), to measure the size of the near-through wall crack-like defects for the leak before break (LBB) criterion, was also investigated and found to be insufficient. A conventional SAFT algorithm was used for improving the sizing using the small aperture technique.     

Efficient Switching and Domain Interlocking Observed in Polyaxial Ferroelectrics

We present transmission electron microscopy observations of domain wall motion in thin freestanding KNbO 3 crystals under applied electric fields. Since there is no substrate, there is no elastic clamping of 90 domains. We observe that curved and tilted 90 domain walls are the most mobile, whereas untilted 90 domain walls are resistant to field-induced motion. We explain this result in terms of two factors. First, the switching pressure on a domain wall ( P 2 m P 1 ) E is determined by the relative electrostatic energies of the neighboring polarizations P 1 and P 2 . Consequently, some 90 domain walls are immobile under certain field directions, leading to domain interlocking. Second, domain walls experiencing a high switching pressure move by a ripple mechanism, and do not move as rigid sheets. The tilted wall region in such a ripple has a polarization charge, and an associated depolarization field, which reduces the local switching barrier. An accumulation of polarization charge can result in a tilted or curved wall, as occurs at the mobile tips of 90 domain needles. Any increase in density of immobile wall configurations with cycle time represents an inherent contribution to fatigue. Uniaxial ferroelectrics, with polarizations parallel to the field, should not experience such domain interlocking.     

Automated cell classification and visualization for analyzing remyelination therapy

Remyelination therapy is a state-of-the-art technique for treating spinal cord injury (SCI). Demyelination—the loss of myelin sheath that insulates axons, is a prominent feature in many neurological disorders resulting in SCI. This lost myelin sheath can be replaced by remyelination. In this paper, we propose an algorithm for efficient automated cell classification and visualization to analyze the progress of remyelination therapy in SCI. Our method takes as input the images of the cells and outputs a density map of the therapeutically important oligodendrocyte-remyelinated axons (OR-axons) which is used for efficacy analysis of the therapy. Our method starts with detecting cell boundaries using a robust, shape-independent algorithm based on iso-contour analysis of the image at progressively increasing intensity levels. The detected boundaries of spatially clustered cells are then separated using the Delaunay triangulation based contour separation method. Finally, the OR-axons are identified and a density map is generated for efficacy analysis of the therapy. Our efficient automated cell classification and visualization of remyelination analysis significantly reduces error due to human subjectivity. We validate the accuracy of our results by extensive cross-verification by the domain experts.     

Turmeric nanofiber-encapsulated natural product formulation act as a phytogenic feed additive—A study in broilers on growth performance,biochemical indices of blood,and E. coli in cecum

A phytogenic feed additive (PFA) formulation was prepared with bioactive molecules—curcuminoids, gingerol, and carvacrol by encapsulating in nanofiber isolated from turmeric spent (turmeric nanofiber, TNF). This formulation was completely characterized by scanning electron microscope, ultra performance liquid chromatography, and gas chromatography and evaluated for its efficacy. PFA-encapsulated TNF (PFA@TNF) considerably increased mean body weight, decreased cholesterol level, mortality rate, and reduced Escherichia coli content of broilers than antibiotic growth promoter (AGP). The depth of crypts in the ileum of broilers was considerably reduced by the inclusion of PFA@TNF in diets compared with the AGP.     

Design procedure for switched-reluctance motors

Some of the design aspects of the switched-reluctance motor for nonservo applications are considered. Towards this objective, a step-by-step procedure is developed for the design of switched-reluctance motors     

Control Characteristics of Inverter-Fed Induction Motor

Efficient use of an inverter-fed induction motor drive necessitates a knowledge of the characteristics of the induction motor from a " control" point of view. The characteristics of both the voltage -and the current-source inverter-fed induction motor drive are investigated, neglecting the filter time constants in the link and feedback loops. Of particular interest is the role played by the voltage/current and frequency inputs. Their effects on variables that are not often discussed such as torque angle, stator real power, airgap flux- linkages and stator and rotor voltages/currents are studied. A by- product of this aspect of the study leads to the nature of feedback signals and their suitability for control purposes. It is also found that the link filter has little effect on relative suitability of these signals. A study of the current source induction motor drive dynamics for torque angle feedback is included.     

Intentional forgetting as a facilitator for recalling new product attributes.

When market changes alter what product attributes are deemed important, consumers may intentionally try to forget old product information in an attempt to remember new product information. In Experiment 1, the authors demonstrated that intentional forgetting of this nature temporarily inhibits retrieval of old product information and leads to a benefit to memory for new product information. The results show that, after a short delay, benefits continue in the absence of costs, which is supportive of a multiple-process account of intentional forgetting. Experiment 2 extends these effects using an advertising message to stimulate forgetting. Across both experiments, results also show that brand preference is based on learning of new attribute information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Leveraging global resources: a process maturity framework for managing distributed development

The popular and well-tested software process frameworks such as the Software Engineering Institute's Capability Maturity Model and ISO 9001, details key process areas for software development. Focusing more on continuous improvement in code development processes, generic-process frameworks such as the CMM lack key process areas (KPA) that address capabilities for managing distributed software projects, such as establishing mutual knowledge and managing geographically dispersed social networks. We identify 24 new KPAs that address the wide-ranging capabilities needed for managing distributed software development and arrange them in an evolutionary order similar to the CMM framework. The evolutionary or phased approach in improving software management capabilities helps firms systematically assess their situations and plan for improvements. We also report the results of a statistically tested maturity assessment survey and test the overall rigor of our model against industry expert opinion and objective data collected from real-world projects implemented at SAP AG, a leading global-enterprise software firm.