Diametral creep of the pressure tube(PT) is one of the principal aging mechanisms governing the heat transfer and hydraulic degradation of a heat transport *** diametral creep leads to diametral expansion that affects...
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Diametral creep of the pressure tube(PT) is one of the principal aging mechanisms governing the heat transfer and hydraulic degradation of a heat transport *** diametral creep leads to diametral expansion that affects the thermal hydraulic characteristics of the coolant channels and the critical heat flux. Therefore,it is essential to predict the PT diametral creep in CANDU reactors,which is caused mainly by fast neutron irradiation,reactor coolant temperature and so forth. The currently used PT diametral creep predictionmodel considers the complex interactions between the effects of temperature and fast neutron flux on the deformation of PT zirconium *** model assumes that long-term steady-state deformation consists of separable,additive components from thermal creep, irradiation creep and irradiation *** is a mechanistic model based on measured ***,this model has high prediction ***,a statistical error modeling method was developed using plant inspection data from the Bruce B CANDU reactor. The aim of this study was to develop a bundle position-wise linearmodel(BPLM) to predict PT diametral creep employing previously measured PT diameters and HTS operating *** are twelve bundles in a fuel channel and for each bundle,a linearmodel was developed by using the dependent variables,such as the fast neutron fluxes and the bundle *** training data set was selected using the subtractive clustering *** data of 39 channels that consist of 80 percent of a total of 49 measured channels from Units 2,3 and 4 were used to develop the BPLM *** remaining 10 channels' data were used to test the developed BPLM *** BPLM was optimized by the maximum likelihood estimation *** developed BPLM to predict PT diametral creep was verified using the operating data gathered from the Units 2,3 and 4 in *** error components for the BPLM,which are the epistemic error and the aleatory error
This paper proposes a novel channel estimation method for TD-HSPA+ system in rapidly time-varying environments. We use a linear prediction model to depict the channel impulse response within a timeslot, then a least s...
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This paper proposes a novel channel estimation method for TD-HSPA+ system in rapidly time-varying environments. We use a linear prediction model to depict the channel impulse response within a timeslot, then a least square (LS) and a minimum mean-square error (MMSE) estimator are deduced respectively based on some statistical characteristics of the channel. We further provide an approach to employ the proposed LS/MMSE method in downlink. As is proved by the simulations, the new estimation method outperforms other existing algorithms a lot. It’s also important to point out that the proposed method is both robust and computationally efficient.
Background: Assessment of DNA profile quality is vital in forensic DNA analysis, both in order to determine the evidentiary value of DNA results and to compare the performance of different DNA analysis protocols. Gene...
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作者：
Wang, WYDef Sci & Technol Org
Aeronaut & Maritime Res Lab Airframes & Engines Div Fishermans Bend Vic 3207 Australia
This paper presents a novel methodology for the diagnosis and prognosis of crucial gear faults, such as gear tooth fatigue cracking. Currently, an effective detection of tooth cracking can be achieved by using the aut...
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ISBN:
(纸本)0819444839
This paper presents a novel methodology for the diagnosis and prognosis of crucial gear faults, such as gear tooth fatigue cracking. Currently, an effective detection of tooth cracking can be achieved by using the autoregressive (AR) modeling approach, where the gear vibration signal is modeled by an AR model and gear tooth cracking is detected by identifying the sudden changes in the model's error signal. The model parameters can be estimated under the criteria of minimum power or maximum kurtosis of model errors. However, these model parameters possess no physical meaning about the monitored gear system. It is proposed that the AR model be replaced by a gear dynamics model (GDM) that contains physically meaningful parameters, such as mass, damping and stiffness. By identifying and tracking the changes in the parameters, it is possible to make diagnosis and prognosis of gear faults. For example, a reduction in mesh stiffness may indicate cracking of a gear tooth. Towards physical model-based prognosis, an adaptive (or optimization) strategy has been developed for approximating a gear signal using a simplified gear signal model. Preliminary results show that this strategy provides a feasible adaptive process for updating model parameters based on measured gear signal.
In this paper, we present a new signal frequency estimation method based on the sinusoidal additive synthesis model. In the proposed method, frequencies in both the signal and noise are estimated with several delay ti...
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In this paper, we present a new signal frequency estimation method based on the sinusoidal additive synthesis model. In the proposed method, frequencies in both the signal and noise are estimated with several delay times by using an expanded linearprediction (LP) method, and assuming that the signal is stationary and noise is unstationary in short record length. Frequencies in the signal are extracted according to their dependence on different delays. The frequency estimation can be accomplished with short record length even in the case where the number of frequency components in the signal is unknown. And it is capable of estimating the frequencies of a signal in the presence of noise. Furthermore, the proposed method estimates the parameters with less computation and high estimation accuracy. Simulation results are provided to confirm the effectiveness of the proposed method. The comparison of estimation accuracy between the proposed method and the analysis by synthesis (ABS) method is shown with the corresponding Cramer-Rao lower bound. And the frequency resolution of this method is also shown.
In this paper,a parameter(***, amplitude and phase) estimation method of acoustic signals is *** frequency estimation of the proposed method is basically based on the linearprediction(LP) *** ordinary LP model assume...
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In this paper,a parameter(***, amplitude and phase) estimation method of acoustic signals is *** frequency estimation of the proposed method is basically based on the linearprediction(LP) *** ordinary LP model assumes that the number of frequency components in the signal is *** proposed method improves the ordinary LP model so as to be applicable for the case where the number of the frequency components is *** amplitude and phase estimation of the proposed method is based on the modified least square error *** results are provided to confirm the effectiveness of the proposed method.
The linear prediction model of speech production is reviewed and its various formulations are related. Algorithms are presented for efficient fixed-point analysis and synthesis, together with their execution times, on...
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The linear prediction model of speech production is reviewed and its various formulations are related. Algorithms are presented for efficient fixed-point analysis and synthesis, together with their execution times, on a small computer. The properties of the model are discussed, and the acoustic-tube analogue is developed. This forms the basis of a system currently being used for deaf speech training. The system is described, and results and experience gained from the initial evaluation period are discussed.
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