Search results for "Extraction"

Ventricular fibrillation detection from ECG surface electrodes using different filtering techniques, window length and artificial neural networks

2017

Medical personnel face many difficulties when diagnosing ventricular fibrillation (VF). Its correct diagnosis allows to decide the right medical treatment and, therefore, it is essential to tell it apart adequately from ventricular tachycardia (VT) and other arrhythmias. If the required therapy is not appropriate, the personnel could cause serious injuries or even induce VF. In this work, a diagnosis automatic system for the detection of VF through feature extraction was developed. To verify the validity of this method, an Artificial Neural Network (ANN) classifier was used. The ECG signals used were obtained from the MIT-BIH Malignant Ventricular Arrhythmia Database and AHA (2000 series) d…

Intrusion Detection with Interpretable Rules Generated Using the Tsetlin Machine

2020

The rapid deployment in information and communication technologies and internet-based services have made anomaly based network intrusion detection ever so important for safeguarding systems from novel attack vectors. To this date, various machine learning mechanisms have been considered to build intrusion detection systems. However, achieving an acceptable level of classification accuracy while preserving the interpretability of the classification has always been a challenge. In this paper, we propose an efficient anomaly based intrusion detection mechanism based on the Tsetlin Machine (TM). We have evaluated the proposed mechanism over the Knowledge Discovery and Data Mining 1999 (KDD’99) …

Combining Auto-Encoder with LSTM for WiFi-Based Fingerprint Positioning

2021

Although indoor positioning has long been investigated by various means, its accuracy remains concern. Several recent studies have applied machine learning algorithms to explore wireless fidelity (WiFi)-based positioning. In this paper, we propose a novel deep learning model which concatenates an auto-encoder with a long short term memory (LSTM) network for the purpose of WiFi fingerprint positioning. We first employ an auto-encoder to extract representative latent codes of fingerprints. Such an extraction is proven to be more reliable than simply using a deep neural network to extract representative features since a latent code can be reverted back to its original input. Then, a sequence o…

Logo detection in images using HOG and SIFT

2017

In this paper we present a study of logo detection in images from a media agency. We compare two most widely used methods — HOG and SIFT on a challenging dataset of images arising from a printed press and news portals. Despite common opinion that SIFT method is superior, our results show that HOG method performs significantly better on our dataset. We augment the HOG method with image resizing and rotation to improve its performance even more. We found out that by using such approach it is possible to obtain good results with increased recall and reasonably decreased precision.

An Encrypted Traffic Classification Framework Based on Convolutional Neural Networks and Stacked Autoencoders

2020

In recent years, deep learning-based encrypted traffic classification has proven to be effective; especially, using neural networks to extract features from raw traffic to classify encrypted traffic. However, most of the neural networks need a fixed-sized input, so that the raw traffic need to be trimmed. This will cause the loss of some information; for example, we do not know the number of packets in a session. To solve these problems, a framework, which implements both a convolutional neural network (CNN) and a stacked autoencoder (SAE), is proposed in this paper. This framework uses a CNN to extract high-level features from raw network traffic and uses an SAE to encode the 26 statistica…

Eco-extraction and encapsulation of carotenoid and anthocyanin pigments from tropical plants

2018

This thesis deals with extraction processes using assistance technologies or green solvents and encapsulation systems of natural pigments in order to exploit and apply them in the food, cosmetic and pharmaceutical industries. In this goal, microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE) and Ionic liquids (IL) were evaluated for the extraction of carotenoids and anthocyanins from Vietnamese plants. The results obtained show that the MAE was always a rapid and helpful system for all types of extraction tested whereas ultrasounds were particularly efficient when pigments are present on the surface of plant tissues. However, UAE was also improving results compared to c…

Discovering representative models in large time series databases

2004

The discovery of frequently occurring patterns in a time series could be important in several application contexts. As an example, the analysis of frequent patterns in biomedical observations could allow to perform diagnosis and/or prognosis. Moreover, the efficient discovery of frequent patterns may play an important role in several data mining tasks such as association rule discovery, clustering and classification. However, in order to identify interesting repetitions, it is necessary to allow errors in the matching patterns; in this context, it is difficult to select one pattern particularly suited to represent the set of similar ones, whereas modelling this set with a single model could…

2016

Abstract. We found that ambient and laboratory-generated secondary organic aerosols (SOA) form substantial amounts of OH radicals upon interaction with liquid water, which can be explained by the decomposition of organic hydroperoxides. The molar OH yield from SOA formed by ozonolysis of terpenes (α-pinene, β-pinene, limonene) is  ∼  0.1 % upon extraction with pure water and increases to  ∼  1.5 % in the presence of Fe2+ ions due to Fenton-like reactions. Upon extraction of SOA samples from OH photooxidation of isoprene, we also detected OH yields of around  ∼  0.1 %, which increases upon addition of Fe2+. Our findings imply that the chemical reactivity and aging of SOA particles is strongl…

Effects of Atropine on Acetylcholine Overflow from Perfused Chicken Hearts

1978

Isolated chicken hearts were perfused (20 ml/min) with Tyrode’s solution. Release of acetylcholine (ACh) was evoked either by electrical stimulation (1 ms; 15 mA) of both preganglionic vagus nerves or by perfusion with dimethylphenylpiperazinium (DMPP). ACh was extracted from the perfusates by ion-pair extraction and determined by gas chromatography.

Fuzzy Fusion in Multimodal Biometric Systems

2007

Multimodal authentication systems represent an emerging trend for information security. These systems could replace conventional mono-modal biometric methods using two or more features for robust biometric authentication tasks. They employ unique combinations of measurable physical characteristics: fingerprint, facial features, iris of the eye, voice print, hand geometry, vein patterns, and so on. Since these traits are hardly imitable by other persons, the aim of these multibiometric systems is to achieve a high reliability to determine or verify person's identity. In this paper a multimodal biometric system using two different fingerprints is proposed. The matching module integrates fuzzy…