Showing 5 results for Amini
F. Aminifar, M. Fotuhi-Firuzabad,
Volume 3, Issue 1 (April 2007)
Abstract
From the optimization point of view, an optimum solution of the unit
commitment problem with reliability constraints can be achieved when all constraints are
simultaneously satisfied rather than sequentially or separately satisfying them. Therefore,
the reliability constraints need to be appropriately formulated in terms of the conventional
unit commitment variables. In this paper, the reliability-constrained unit commitment
problem is formulated in a mixed-integer program format. Both the unit commitment risk
and the response risk are taken into account as the probabilistic criteria of the operating
reserve requirement. In addition to spinning reserve of generating units, interruptible load is
also included as a part of operating reserve. The numerical studies using IEEE-RTS
indicate the effectiveness of the proposed formulation. The obtained results are presented
and the implementation issues are discussed. Two sensitivity analyses are also fulfilled to
illustrate the effects of generating unit failure rates and interruption time of interruptible
load.
A. Ghaffari, M. R. Homaeinezhad, M. Akraminia,
Volume 6, Issue 1 (March 2010)
Abstract
The aim of this study is to address a new feature extraction method in the area of the heart arrhythmia classification based on a metric with simple mathematical calculation called Curve-Length Method (CLM). In the presented method, curve length of the under study excerpted segment of signal is considered as an informative feature in which the effect of important geometric parameters of the original signal can be found. To show merits of the presented method, first the original electrocardiogram (ECG) in lead I is pre-processed by removing its baseline wander then by scaling it in the [-1,1] interval. In the next step, using a trous method, discrete wavelet scales 23 and 24 and smoothing function scale 22 are extracted. Afterwards, segments including samples of the QRS complex, P and T waves are estimated via an approximation criterion and CLM is implemented to extract corresponding features from aforementioned scales, smoothing function and also from each original segment. The resulted feature vector (including 12 components) is used to tune an Adaptive Network Fuzzy Inference System (ANFIS) classifier. The presented strategy is applied to classify four categories found in the MIT-BIH Arrhythmia Database namely as Atrial Premature Beat (APB), Left Bundle Branch Block (LBBB), Right Bundle Branch Block (RBBB) and Premature Ventricular Contraction (PVC) and average values of Se = 99.81%, P+ = 99.80%, Sp = 99.81% and Acc = 99.72% are obtained for sensitivity, positive predictivity, specifity and accuracy respectively showing marginal improvement of the heart arrhythmia classification performance.
M. M Daevaeiha, M. R Homaeinezhad, M. Akraminia, A. Ghaffari, M. Atarod,
Volume 6, Issue 3 (September 2010)
Abstract
The aim of this study is to introduce a new methodology for isolation of ectopic
rhythms of ambulatory electrocardiogram (ECG) holter data via appropriate statistical
analyses imposing reasonable computational burden. First, the events of the ECG signal are
detected and delineated using a robust wavelet-based algorithm. Then, using Binary
Neyman-Pearson Radius test, an appropriate classifier is designed to categorize ventricular
complexes into "Normal + Premature Atrial Contraction (PAC)" and "Premature
Ventricular Contraction (PVC)" beats. Afterwards, an innovative measure is defined based
on wavelet transform of the delineated P-wave namely as P-Wave Strength Factor (PSF)
used for the evaluation of the P-wave power. Finally, ventricular contractions pursuing
weak P-waves are categorized as PAC complexes however, those ensuing strong P-waves
are specified as normal complexes. The discriminant quality of the PSF-based feature space
was evaluated by a modified learning vector quantization (MLVQ) classifier trained with
the original QRS complexes and corresponding Discrete Wavelet Transform (DWT) dyadic
scale. Also, performance of the proposed Neyman-Pearson Classifier (NPC) is compared
with the MLVQ and Support Vector Machine (SVM) classifiers using a common feature
space. The processing speed of the proposed algorithm is more than 176,000 samples/sec
showing desirable heart arrhythmia classification performance. The performance of the
proposed two-lead NPC algorithm is compared with MLVQ and SVM classifiers and the
obtained results indicate the validity of the proposed method. To justify the newly defined
feature space (σi1, σi2, PSFi), a NPC with the proposed feature space and a MLVQ
classification algorithm trained with the original complex and its corresponding DWT as
well as RR interval are considered and their performances were compared with each other.
An accuracy difference about 0.15% indicates acceptable discriminant quality of the
properly selected feature elements. The proposed algorithm was applied to holter data of
the DAY general hospital (more than 1,500,000 beats) and the average values of Se =
99.73% and P+ = 99.58% were achieved for sensitivity and positive predictivity,
respectively.
F. Amini, R. Kazemzadeh,
Volume 13, Issue 1 (March 2017)
Abstract
Development of distributed generations’ technology, trends in the use of these sources to improve some of the problems such as high losses, low reliability, low power quality and high costs in distributed networks. Choose the correct location to install and proper capacity of these sources, such as important things that must be considered in their use. Since distribution networks are actually unbalanced and asymmetric consumption loads are different, so in this paper with optimal placement and sizing of distributed generation sources that dependent on the load model and type of load connection and the uncertainties which caused by the generated power of wind turbines and solar panels, the positive effects of these sources have been examined on unbalanced distribution network. Hence with linear three-phase unbalanced load flow method and IPSO algorithm, allocation of distributed generation sources in IEEE standard of 37 bus unbalanced network have been done. Obtained results show improvement of voltage profile in each phase and reduction of network power losses and buses’ voltage unbalance factor.
Pedram Yamini, Fatemeh Daneshfar, Abuzar Ghorbani,
Volume 20, Issue 4 (December (Special Issue on ADLEEE) 2024)
Abstract
With the exponential growth of unstructured data on the Web and social networks, extracting relevant information from multiple sources; has become increasingly challenging, necessitating the need for automated summarization systems. However, developing machine learning-based summarization systems largely depends on datasets, which must be evaluated to determine their usefulness in retrieving data. In most cases, these datasets are summarized with humans’ involvement. Nevertheless, this approach is inadequate for some low-resource languages, making summarization a daunting task. To address this, this paper proposes a method for developing the first abstractive text summarization corpus with human evaluation and automated summarization model for the Sorani Kurdish language. The researchers compiled various documents from information available on the Web (rudaw), and the resulting corpus was released publicly. A customized and simplified version of the mT5-base transformer was then developed to evaluate the corpus. The model's performance was assessed using criteria such as Rouge-1, Rouge-2, Rouge-L, N-gram novelty, manual evaluation and the results are close to reference summaries in terms of all the criteria. This unique Sorani Kurdish corpus and automated summarization model have the potential to pave the way for future studies, facilitating the development of improved summarization systems in low-resource languages.