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1.
基于模糊神经网络和符号的地震预报专家系统NGESEP 总被引：7，自引：0，他引：7
本文介绍了专家系统的发展、神经网络、模糊系统与专家系统相结合的优点以及新一代地震报专家系统的构成等。该系统除具有传统专家系统的特点外，还因使用模糊联想记忆神经网络模型而具有良好的学习功能。文中也对ＦＡＭ神经网络模型及其应用作了介绍。 相似文献
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3.
Hwa-Lung Yu Alexander Kolovos George Christakos Jiu-Chiuan Chen Steve Warmerdam Boris Dev 《Stochastic Environmental Research and Risk Assessment (SERRA)》2007,21(5):647-572
This paper describes the spatiotemporal epistematics knowledge synthesis and graphical user interface (SEKS–GUI) framework
and its application in medical geography problems. Based on sound theoretical reasoning, the interactive software library
of SEKS–GUI explores heterogeneous (spatially non-homogeneous and temporally non-stationary) health attribute distributions
(disease incidence, mortality, human exposure, epidemic propagation etc.); expresses the health system’s dependence structure
using (ordinary and generalized) spatiotemporal covariance models; synthesizes core knowledge bases, empirical evidence and
multi-sourced system uncertainty; and generates a meaningful picture of the real-world system using space–time dependent probability
functions and associated maps of health attributes. The implementation stages of the SEKS–GUI library are described in considerable
detail using appropriate screens. The wide applicability of SEKS–GUI is demonstrated by reviewing a selection of real-world
case studies.
An erratum to this article can be found at 相似文献
4.
A new inelastic structural control algorithm is proposed by incorporating the force analogy method (FAM) with the predictive instantaneous optimal control (PIOC) algorithm. While PIOC is very effective in compensating for the time delay for elastic structures, the FAM is highly efficient in performing the inelastic analysis. Unlike conventional inelastic analysis methods of changing stiffness, the FAM analyzes structures by varying the structural displacement field, and therefore the state transition matrix needs to be computed only once. This greatly simplifies the computation and makes inelastic analysis readily applicable to the PIOC algorithm. The proposed algorithm compensates for the time delay that happens in practical control systems by predicting the inelastic structural response over a period that equals the magnitude of the time delay. A one‐story frame with both strain‐hardening and strain‐softening inelastic characteristics is analyzed using this algorithm. Results show that the proposed control algorithm is feasibile for any inelastic structures. While the control efficiency deteriorates with the increase in magnitude of the time delay, the PIOC maintains acceptable performance within a wide range of time delay magnitudes. Finally, a computer model of a six‐story moment‐resisting steel frame is analyzed to show that PIOC has good control results for real inelastic structures. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
5.
Ecological network analysis of an urban energy metabolic system 总被引：2，自引：1，他引：1
Jinyun Zhang Yan Zhang Zhifeng Yang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(5):685-695
Analysis of the structure and function of urban energy metabolic systems is an important tool to facilitate compliance with
China’s current energy-conservation policy. In this study, we used network throughflow analysis and network utility analysis
to analyze the structure of an urban energy metabolic system and the complex relationships among its components. Using weight
distributions in the network flow matrix, we determined the system structure; using the sign distribution in the network utility
matrix, we determined the relationships between pairs of components. We then developed an ecological network model using Beijing
in 1995, 2000, 2005, and 2007 as an example of how the model can be used to understand the system’s structure and function.
The model’s components were the energy exploitation, transformation, consumption, and recovery sectors. Network throughflow
analysis revealed that the energy transformation and consumption sectors had high weights (34–45%) in all 4 years, whereas
the energy recovery sector had small weights (<5%) and the energy exploitation had low to intermediate weights (which decreased
from 23% in 1995 to 11% in 2007). Network utility analysis revealed that the ecological relationships between the energy transformation
and exploitation sectors, the energy consumption and transformation sectors, and the energy consumption and exploitation sectors
did not change, but that the ecological relationships between the energy recovery sector and other sectors changed greatly.
Our analysis of Beijing’s urban energy metabolic system provided guidance for optimizing the system’s structure and adjusting
the relationships among the sectors. 相似文献
6.
Sh. R. Bogoutdinov A. D. Gvishiani S. M. Agayan A. A. Solovyev E. Kin 《Izvestiya Physics of the Solid Earth》2010,46(11):1004-1016
The International Real-time Magnetic Observatory Network (INTERMAGNET) is the world’s biggest international network of ground-based
observatories, providing geomagnetic data almost in real time (within 72 hours of collection) [Kerridge, 2001]. The observation
data are rapidly transferred by the observatories participating in the program to regional Geomagnetic Information Nodes (GINs),
which carry out a global exchange of data and process the results. The observations of the main (core) magnetic field of the
Earth and its study are one of the key problems of geophysics. The INTERMAGNET system is the basis of monitoring the state
of the Earth’s magnetic field; therefore, the information provided by the system is required to be very reliable. Despite
the rigid high-quality standard of the recording devices, they are subject to external effects that affect the quality of
the records. Therefore, an objective and formalized recognition with the subsequent remedy of the anomalies (artifacts) that
occur on the records is an important task. Expanding on the ideas of Agayan [Agayan et al., 2005] and Gvishiani [Gvishiani
et al., 2008a; 2008b], this paper suggests a new algorithm of automatic recognition of anomalies with specified morphology,
capable of identifying both physically- and anthropogenically-derived spikes on the magnetograms. The algorithm is constructed
using fuzzy logic and, as such, is highly adaptive and universal. The developed algorithmic system formalizes the work of
the expert-interpreter in terms of artificial intelligence. This ensures identical processing of large data arrays, almost
unattainable manually. Besides the algorithm, the paper also reports on the application of the developed algorithmic system
for identifying spikes at the INTERMAGNET observatories. The main achievement of the work is the creation of an algorithm
permitting the almost unmanned extraction of spike-free (definitive) magnetograms from preliminary records. This automated
system is developed for the first time with the application of fuzzy logic system for geomagnetic measurements. It is important
to note that the recognition of time disturbances is formalized and identical. The algorithm presented here appreciably increases
the reliability of spike-free INTERMAGNET magnetograms, thus increasing the objectivity of our knowledge of the Earth’s magnetic
field. At the same time, the created system can accomplish identical, formalized, and retrospective analysis of large archives
of digital and digitized magnetograms, accumulated in the system of Worldwide Data Centers. The relevant project has already
been initiated as a collaborative initiative of the Worldwide Data Center at Geophysical Center (Russian Academy of Sciences)
and the NOAA National Geophysical Data Center (Unite States). Thus, by improving and adding objectivity to both new and historical
initial data, the developed algorithmic system may contribute appreciably to improving our understanding of the Earth’s magnetic
field. 相似文献
7.
Toloue Iraj Liew Mohd Shahir Harahap Indra Sati Hamonangan Lee Hsiu Eik 《地震工程与工程振动(英文版)》2020,19(1):137-147
The force analogy method(FAM) is considered as one of the most time-saving and cost-efficient methods for analyzing frames. Through a set of assumptions and restoring forces, FAM analyzes nonlinear frames responses through Hooke's law. This study evaluates the effect of element type on FAM through numerical and experimental tests. The conventional Euler Bernoulli(EB) element is replaced by the Timoshenko(TS) beam-column element and the results are interpreted and compared with experimental findings. Three experimental tests were conducted for benchmarking and comparison purposes via 2 D aluminum frames. The results indicated that during the analysis, when the frame response is in the linear region, there is no difference between the element types in the response of the frames. When the frame entered the plastic region, the frames which were analyzed by the TS element revealed closer responses to the experimental outcomes. The gap between the results of the frame which was analyzed by EB and TS enlarged especially when the frame experienced a sharp or huge rotation of more than 0.2 rad. The final recorded deformations based on the TS element revealed an accuracy between 98.05% to 98.65%, while the EB element showed 14.66% to 45.14% for rotations of more than 0.2 rad at plastic hinge locations(PHLs). 相似文献
8.
Elisa Zambonelli Rita de Nardis Luisa Filippi Mario Nicoletti Mauro Dolce 《Bulletin of Earthquake Engineering》2011,9(1):39-65
On April 6, 2009, the town of L’Aquila in the Abruzzo region (central Italy) was struck by a seismic event at 01:32 (UTC),
of magnitude MW = 6.3. The mainshock was followed by a long period of intense seismic activity and within seven days after the mainshock
there were seven events of magnitude MW ≥ 5 that occurred from April 6 to April 13. This long seismic sequence was characterized by a complex rupture mechanism that
involved two major normal faults of the central Apennines: the Paganica and the Gorzano faults. The strong-motions of the
mainshock were recorded by 64 stations of the Italian Strong-motion Network (RAN) operated by the National Civil Protection
Department (DPC). Six stations of a local strong-motion array were working in NW L’Aquila suburb area. One of them, located
at about 6 km from the Paganica fault surface tip-line, set up in trigger mode, recorded continuously for more than 20 min
the mainshock and the aftershocks. Besides the mainshock, the RAN stations recorded in total 78 foreshocks and aftershocks
of ML ≥ 3.5, during the period from January to December 2009. The corresponding waveforms provide the most extensive digital strong
ground motion data set ever recorded in Italy. Moreover, the 48 three-component observations of events of magnitude MW ≥ 5, recorded at a distance less than 15 km from each of the major involved faults, provide a significant increasing of near-field
records available for the Italian territory. Six days after the mainshock, the strong-motion dataset, referred to preliminary
locations of the events with ML ≥ 4.0, was made available on the DPC web site () and at the same time it was delivered to the ITACA database (). This dataset has been used by many authors in scientific papers and by engineers, geophysicists and geologists for professional
technical works. In this paper, the present-day available strong-motion signals from the L’Aquila sequence and the performance
of the Italian strong-motion network in terms of the number and quality of recorded data, the geometry and data transmission
system are described. In addition the role of the temporary network that represents an extension of the permanent Italian
strong-motion network, supporting the emergency response by civil protection authorities and improving the network coverage
has been evaluated. 相似文献
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10.
新疆地震台网应用JOPENS应用软件系统进行地震速报、地震编目等日常工作,应用JOPENS系统的服务器能否稳定安全的运行至关重要.在应用JOPENS系统过程中,遇到了一些服务器运行的问题,针对服务器出现的问题,利用MYSQL数据库命令、UNUX系统的相关知识及shell语言和磁盘阵列技术给出了具体的解决方案. 相似文献
11.
Rafi Baker George Christakos 《Stochastic Environmental Research and Risk Assessment (SERRA)》2007,21(4):435-446
The well-known “Maximum Entropy Formalism” offers a powerful framework for deriving probability density functions given a
relevant knowledge base and an adequate prior. The majority of results based on this approach have been derived assuming a
flat uninformative prior, but this assumption is to a large extent arbitrary (any one-to-one transformation of the random
variable will change the flat uninformative prior into some non-constant function). In a companion paper we introduced the
notion of a natural reference point for dimensional physical variables, and used this notion to derive a class of physical
priors that are form-invariant to changes in the system of dimensional units. The present paper studies effects of these priors
on the probability density functions derived using the maximum entropy formalism. Analysis of real data shows that when the
maximum entropy formalism uses the physical prior it yields significantly better results than when it is based on the commonly
used flat uninformative prior. This improvement reflects the significance of the incorporating additional information (contained
in physical priors), which is ignored when flat priors are used in the standard form of the maximum entropy formalism. A potentially
serious limitation of the maximum entropy formalism is the assumption that sample moments are available. This is not the case
in many macroscopic real-world problems, where the knowledge base available is a finite sample rather than population moments.
As a result, the maximum entropy formalism generates a family of “nested models” parameterized by the unknown values of the
population parameters. In this work we combine this formalism with a model selection scheme based on Akaike’s information
criterion to derive the maximum entropy model that is most consistent with the available sample. This combination establishes
a general inference framework of wide applicability in scientific/engineering problems. 相似文献
12.
Chiara Turino Paola Morasca Gabriele Ferretti Davide Scafidi Daniele Spallarossa 《Journal of Seismology》2010,14(2):393-411
Reliable automatic procedure for locating earthquake in quasi-real time is strongly needed for seismic warning system, earthquake
preparedness, and producing shaking maps. The reliability of an automatic location algorithm is influenced by several factors
such as errors in picking seismic phases, network geometry, and velocity model uncertainties. The main purpose of this work
is to investigate the performances of different automatic procedures to choose the most suitable one to be applied for the
quasi-real-time earthquake locations in northwestern Italy. The reliability of two automatic-picking algorithms (one based
on the Characteristic Function (CF) analysis, CF picker, and the other one based on the Akaike’s information criterion (AIC),
AIC picker) and two location methods (“Hypoellipse” and “NonLinLoc” codes) is analysed by comparing the automatically determined
hypocentral coordinates with reference ones. Reference locations are computed by the “Hypoellipse” code considering manually
revised data and tested using quarry blasts. The comparison is made on a dataset composed by 575 seismic events for the period
2000–2007 as recorded by the Regional Seismic network of Northwestern Italy. For P phases, similar results, in terms of both
amount of detected picks and magnitude of travel time differences with respect to manual picks, are obtained applying the
AIC and the CF picker; on the contrary, for S phases, the AIC picker seems to provide a significant greater number of readings
than the CF picker. Furthermore, the “NonLinLoc” software (applied to a 3D velocity model) is proved to be more reliable than
the “Hypoellipse” code (applied to layered 1D velocity models), leading to more reliable automatic locations also when outliers
(wrong picks) are present. 相似文献
13.
The objective of this research is to determine the effect earthquakes have on the performance of transportation network systems. To do this, bridge fragility curves, expressed as a function of peak ground acceleration (PGA) and peak ground velocity (PGV), were developed. Network damage was evaluated under the 1994 Northridge earthquake and scenario earthquakes. A probabilistic model was developed to determine the effect of repair of bridge damage on the improvement of the network performance as days passed after the event. As an example, the system performance degradation measured in terms of an index, “Drivers Delay,“ is calculated for the Los Angeles area transportation system, and losses due to Drivers Delay with and without retrofit were estimated. 相似文献
14.
3D inversion of DC data using artificial neural networks 总被引：2，自引：0，他引：2
Ahmad Neyamadpour W. A. T. Wan Abdullah Samsudin Taib Danesh Niamadpour 《Studia Geophysica et Geodaetica》2010,54(3):465-485
In this paper, we investigate the applicability of artificial neural networks in inverting three-dimensional DC resistivity
imaging data. The model used to produce synthetic data for training the artificial neural network (ANN) system was a homogeneous
medium of resistivity 100 Ωm with an embedded anomalous body of resistivity 1000 Ωm. The different sizes for anomalous body
were selected and their location was changed to different positions within the homogeneous model mesh elements. The 3D data
set was generated using a finite element forward modeling code through standard 3D modeling software. We investigated different
learning paradigms in the training process of the neural network. Resilient propagation was more efficient than any other
paradigm. We studied the effect of the data type used on neural network inversion and found that the use of location and the
apparent resistivity of data points as the input and corresponding true resistivity as the output of networks produces satisfactory
results. We also investigated the effect of the training data pool volume on the inversion properties. We created several
synthetic data sets to study the interpolation and extrapolation properties of the ANN. The range of 100–1000 Ωm was divided
into six resistivity values as the background resistivity and different resistivity values were also used for the anomalous
body. Results from numerous neural network tests indicate that the neural network possesses sufficient interpolation and extrapolation
abilities with the selected volume of training data. The trained network was also applied on a real field dataset, collected
by a pole-pole array using a square grid (8 ×8) with a 2-m electrode spacing. The inversion results demonstrate that the trained
network was able to invert three-dimensional electrical resistivity imaging data. The interpreted results of neural network
also agree with the known information about the investigation area. 相似文献
15.
The development of coastal ocean modeling in the recent years has allowed an improved representation of the associated complex
physics. Such models have become more realistic, to the point that they can now be used to design observation networks in
coastal areas, with the idea that a “good” network is a network that controls model state error. To test this ability without
performing data assimilation, we set up a technique called Representer Matrix Spectra (RMS) technique that combines the model
state and observation error covariance matrices into a single scaled representer matrix. Examination of the spectrum and the
eigenvectors of that matrix informs us on which model state error modes a network can detect and constrain amidst the observation
error background. We applied our technique to a 3D coastal model in the Bay of Biscay, with a focus on mesoscale activity,
and tested the performance of various altimetry networks and an in situ array deployment strategy. It appears that a single
nadir altimeter is not efficient enough at capturing coastal mesoscale physics, while a wide swath altimeter would do a much
better job. Testing various local in situ array configurations confirms that adding a current meter to a vertical temperature
measurement array improves the detection of secondary variability modes, while shifting the array higher on the shelf break
would obviously enhance the model constraint along the coast. The RMS technique is easily set up and used as a “black box,”
but the utility of its results is maximized by previous knowledge of model state error physics. The technique provides both
quantitative (eigenvalues) and qualitative (eigenvectors) tools to study and compare various network options. The qualitative
approach is essential to discard possibly inconsistent modes. 相似文献
16.
The Expert System For Earthquake Prediction (ESEP) is summarized in this paper. ESEP embraces three subsystems: long-middle
term prediction system, annual prediction system and middle-short term prediction system. Each of the subsystems is composed
of seven modules: the controlling module, the data base module, the expert knowledge base module, the method base module,
the fact preparation module, the reasoning and decision-making module and the plotting and displaying module.
The reasoning model ESEP/R and the knowledge expression model ESEP/K are set up in the ESEP, and new evidence combinations,
CON (confine), W (weigh), and SYN (synthesize), have been proposed. The distinctive features of the ESEP are: (1) systemized;
(2) several experts’ knowledge can be synthesized; (3) a large amount of data and experts’ experience is embraced; (4) four
reasoning models and the synthetic decision-making technic are adopted; (5) several software environments are used; (6) modularization;
and (7) possessing the friendly user interfaces.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 1–8, 1992. 相似文献
17.
Assessment of temporal and spatial variation of coastal water quality and source identification along Macau peninsula 总被引：11，自引：5，他引：6
Jinliang Huang Manhim Ho Pengfei Du 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(3):353-361
Cluster analysis (CA), discriminant analysis (DA) and principal component analysis (PCA) were comprehensively coupled to explore
and identify the spatial and temporal variation and potential pollution sources in coastal water quality along Macau peninsula.
The results show that the 12 months could be grouped into two periods, June–September and the remaining months, and the entire
area divided into two clusters, one located at the western sides, and the other on the southeast and southern sides of the
Macau peninsula. Through backward stepwise DA, pH, Cl−, TSS, Color and TP, Chloride, Color, NH4
+, DO, COD were discriminant variables of spatial and temporal variation, with 84.82 and 76.54% correct assignments, respectively.
Fecal pollution, organic pollution and soil weathering are among the major sources for coastal water quality deterioration
along Macau peninsula. This study illustrates that application of multivariate statistical techniques was beneficial to gain
knowledge for further optimizing the monitoring network and controlling coastal water quality along Macau peninsula. 相似文献
18.
E. L. Afraimovich I. K. Edemsky S. V. Voeykov Yu. V. Yasukevich I. V. Zhivetiev 《Geomagnetism and Aeronomy》2010,50(1):79-95
The morphology of medium-scale traveling wave packets is for the first time presented based on the total electron content
(TEC), measured at the global network of GPS receivers (up to 1500 stations) during the long period (from 1998 to 2007) and
at the GPS/GEONET dense Japan network (1220 stations) in 2008—2009. In the time domain, these packets are chains of narrowband
TEC variations (trains) with a duration of about 1—2 h, a total duration of up to 6 h, and a variation period of 10—30 min.
In the winter Northern Hemisphere, traveling wave packets are observed mostly 3 h after the passage of the morning solar terminator.
In the equinox they appear after the passage of the solar terminator without a pronounced delay or advance. In summer traveling
wave packets are registered 1.5—2 h before the appearance of the evening solar terminator at the observation point when the
solar terminator passes in the magnetically conjugate region. The spatial structure of traveling wave packets is characterized
by a high degree of anisotropy and coherence at a distance larger than ten wavelengths (the wavelength is 100—300 km). A high
quality of the oscillatory system and synchronization with the appearance of the solar terminator at the observation point
and in the magnetically conjugate region indicate that the generation of traveling wave packets by the solar terminator is
of the MHD nature. Our results for the first time experimentally confirm the hypothesis that the solar terminator generates
ion sound waves, proposed by Huba et al. [2000b]. 相似文献
19.
The purpose of this research is to include expert knowledge as one part of the modelling system and therefore offer the chance to create a productive interaction system between expert, mathematical model (MMO8) and artificial neural networks (ANNs). In the present project, the first objective is to determine some parameters by the MMO8 model, introduced as ANN input parameters to forecast spring outflow. The second objective is first to investigate the effect of temporal information by taking current and past data sets and then to forecast spring outflow. The good results obtained reveal the merit of the ANNs–MMO8 combination, and specifically multilayer perceptron (MLP) models. This methodology, for a network with lower, lag and number hidden layer, consistently produced better performance. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
20.
A neural network approach for the real-time detection of faults 总被引：2，自引：2，他引：0
Fault detection is an essential part of the operation of any chemical plant. Early detection of faults is important in chemical
industry since a lot of damage and loss can result before a fault present in the system is detected. Even though fault detection
algorithms are designed and implemented for quickly detecting incidents, most these algorithms do not have an optimal property
in terms of detection delay with respect to false alarm rate. Based on the optimization property of cumulative sum (CUSUM),
a real-time system for detecting changes in dynamic systems is designed in this paper. This work is motivated by combining
two fault detection (FD) strategies; a simplified procedure of the incident detection problem is formulated by using both
the artificial neural networks (ANN) and the CUSUM statistical test (Page–Hinkley test). The design of a model-based residual
generator is intended to reveal any drift from the normal behavior of the process. In order to obtain a reliable model for
the normal process dynamics, the neural black-box modeling by means of a nonlinear auto-regressive with eXogenous input (NARX)
model has been chosen in this study. This paper also shows the choice and the performance of the neural network in the training
and test phases. After describing the system architecture and the proposed methodology of the fault detection, we present
a realistic application in order to show the technique’s potential. The purpose is to develop and test the fault detection
method on a real incident data, to detect the change presence, and pinpoint the moment it occurred. The experimental results
demonstrate the robustness of the FD method. 相似文献