| 1. |
- Georgoulas, George, et al.
(författare)
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Principal component analysis of the start-up transient and hidden Markov modeling for broken rotor bar fault diagnosis in asynchronous machines
- 2013
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Ingår i: Expert systems with applications. - : Elsevier BV. - 0957-4174 .- 1873-6793. ; 40:17, s. 7024-7033
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a novel computational method for the diagnosis of broken rotor bars in three phase asynchronous machines. The proposed method is based on Principal Component Analysis (PCA) and is applied to the stator’s three phase start-up current. The fault detection is easier in the start-up transient because of the increased current in the rotor circuit, which amplifies the effects of the fault in the stator’s current independently of the motor’s load. In the proposed fault detection methodology, PCA is initially utilized to extract a characteristic component, which reflects the rotor asymmetry caused by the broken bars. This component can be subsequently processed using Hidden Markov Models (HMMs). Two schemes, a multiclass and a one-class approach are proposed. The efficiency of the novel proposed schemes is evaluated by multiple experimental test cases. The results obtained indicate that the suggested approaches based on the combination of PCA and HMM, can be successfully utilized not only for identifying the presence of a broken bar but also for estimating the severity (number of broken bars) of the fault.
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| 2. |
- Mustafa, Mohammed Obaid, et al.
(författare)
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Bearing fault classification based on minimum volume ellipsoid feature extraction
- 2013
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Ingår i: 2013 IEEE Multiconference on Systems and Control (MSC), Hyderabad, India, August, 28-30, 2013. ; , s. 1177-1182
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Konferensbidrag (refereegranskat)abstract
- This article presents a novel fault classification and diagnosis technique for bearings based on a Minimum Volume Ellipsoid (MVE) method for feature extraction. Data from two accelerometers located at two different sights of the test bed are combined to create a two dimensional representation and the feature extraction stage condenses that information using an ellipsoid description. The proposed features feed a simple non-linear classifier which separates almost perfectly between normal and faulty conditions, with also very high diagnostic accuracy between the faulty classes. The obtained results suggest that this novel representation can be used within a condition monitoring system.
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| 3. |
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| 4. |
- Georgoulas, George G., 1976-, et al.
(författare)
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Harmony search augmented with optimal computing budget allocation capabilities for noisy optimization
- 2013
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Ingår i: IAENG International Journal of Computer Science. - 1819-656X .- 1819-9224. ; 40:4, s. 285-290
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Tidskriftsartikel (refereegranskat)abstract
- In this work we introduce the combinatory use of Harmony Search (HS) with Optimal Computing Budget Allocation (OCBA) as a means to tackle noisy optimization situations as those that occur during the execution of Discrete Event Systems (DES) for modeling complex systems. The OCBA procedure is employed for the exclusion of the worst harmony during the memory updating process in order to minimize the computational cost and at the same time retain a pool of promising solutions. The proposed hybrid approach is tested on real valued test functions as a proof of concept and the results are promising in case of small computational budgets.
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| 5. |
- Kolios, Stavros, et al.
(författare)
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Achieving downscaling of Meteosat thermal infrared imagery using artificial neural networks
- 2013
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Ingår i: International Journal of Remote Sensing. - : Taylor & Francis. - 0143-1161 .- 1366-5901. ; 34:21, s. 7706-7722
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Tidskriftsartikel (refereegranskat)abstract
- This study presents the successful application of artificial neural networks (ANNs) for downscaling Meteosat Second Generation thermal infrared satellite imagery. The scope is to examine, propose, and develop an integrated methodology to improve the spatial resolution of Meteosat satellite images. The proposed approach may contribute to the development of a general methodology for monitoring and downscaling Earth's surface characteristics and cloud systems, where there is a clear need for contiguous, accurate, and high-spatial resolution data sets (e.g. improvement of climate model input data sets, early warning systems about extreme weather phenomena, monitoring of parameters such as solar radiation fluxes, land-surface temperature, etc.). Moderate Resolution Imaging Spectroradiometer (MODIS) images are used to validate the downscaled Meteosat images. In terms of the ANNs, a multilayer perceptron (MLP) is used and the results are shown to compare favourably against a linear regression approach.
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| 6. |
- Sapsanis, Christos, et al.
(författare)
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Improving EMG based classification of basic hand movements using EMD
- 2013
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Ingår i: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS 2013. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781457702167 ; , s. 5754-5757
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Konferensbidrag (refereegranskat)abstract
- This paper presents a pattern recognition approach for the identification of basic hand movements using surface electromyographic (EMG) data. The EMG signal is decomposed using Empirical Mode Decomposition (EMD) into Intrinsic Mode Functions (IMFs) and subsequently a feature extraction stage takes place. Various combinations of feature subsets are tested using a simple linear classifier for the detection task. Our results suggest that the use of EMD can increase the discrimination ability of the conventional feature sets extracted from the raw EMG signal.
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| 7. |
- Simioni, Fabrizio, et al.
(författare)
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A software architecture for integrated logistic management system
- 2013
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Konferensbidrag (refereegranskat)abstract
- This paper presents an integrated software architecture for the management of transfer goods (trucks and containers) between port and dry-port facilities. This system is a large scale system and it has to deal with huge and continuously updated set of information. The required information is gathered from other information systems managing business activities within the involved areas. This is the reason why there was required the development of software components that are able to manage the processes of acquiring and sending information to the other systems. In this paper the technological choices and the main information flows managed are described.
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