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排序方式: 共有1192条查询结果,搜索用时 31 毫秒
61.
Sorption of elemental mercury by activated carbons 总被引:1,自引:0,他引:1
62.
Sree Hari Krishnan Parthasarathi R. Padmanabhan Hema A. Murthy 《International Journal of Speech Technology》2011,14(4):361-368
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. 相似文献
63.
L. Satyanarayan Anish Kumar T. Jayakumar C. V. Krishnamurthy Krishnan Balasubramaniam Baldev Raj 《Journal of Nondestructive Evaluation》2009,28(3-4):111-124
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. 相似文献
64.
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. 相似文献
65.
66.
Krishnan R. Arumugan R. Lindsay J.F. 《Industry Applications, IEEE Transactions on》1988,24(3):456-461
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 相似文献
67.
Krishnan R. Stefanovic Victor R. Lindsay James F. 《Industry Applications, IEEE Transactions on》1983,(1):94-104
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. 相似文献
68.
Shapiro Stewart; Lindsey Charles; Krishnan H. Shanker 《Canadian Metallurgical Quarterly》2006,12(4):251
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) 相似文献
69.
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. 相似文献
70.
Ok I. Hyoung-sub Kim Manhong Zhang Chang-Yong Kang Se Jong Rhee Changhwan Choi Krishnan S.A. Tackhwi Lee Feng Zhu Thareja G. Lee J.C. 《Electron Device Letters, IEEE》2006,27(3):145-147
In this letter, we studied the effects of post-deposition anneal (PDA) time and Si interface control layer (ICL) on the electrical characteristics of the MOS capacitor with high-/spl kappa/ (HfO/sub 2/) material on GaAs. Thin equivalent oxide thickness (EOT<3 nm) with excellent capacitance-voltage (C-V) characteristics has been obtained. The thickness of the Si ICL and PDA time were correlated with C-V characteristics. It was found that high temperature Si ICL deposition and longer PDA time at 600/spl deg/C improved the C-V shape, leakage current, and especially frequency dispersion (<5%). 相似文献