153 research outputs found

    Entropic Analysis of Votes Expressed in Italian Elections between 1948 and 2018

    Get PDF
    open access articleIn Italy, the elections occur often, indeed almost every year the citizens are involved in a democratic choice for deciding leaders of different administrative entities. Sometimes the citizens are called to vote for filling more than one office in more than one administrative body. This phenomenon has occurred 35 times after 1948; it creates the peculiar condition of having the same sample of people expressing decisions on political bases at the same time. Therefore, the Italian contemporaneous ballots constitute the occasion to measure coherence and chaos in the way of expressing political opinion. In this paper, we address all the Italian elections that occurred between 1948and2018. Wecollectthenumberofvotesperpartyateachadministrativelevelandwetreateach electionasamanifestationofacomplexsystem. Then,weusetheShannonentropyandtheGiniIndex to study the degree of disorder manifested during different types of elections at the municipality level. A particular focus is devoted to the contemporaneous elections. Such cases implicate different disorder dynamics in the contemporaneous ballots, when different administrative level are involved. Furthermore, some features that characterize different entropic regimes have emerged

    Entropy-based feature extraction for electromagnetic discharges classification in high-voltage power generation

    Get PDF
    This work exploits four entropy measures known as Sample, Permutation, Weighted Permutation, and Dispersion Entropy to extract relevant information from Electromagnetic Interference (EMI) discharge signals that are useful in fault diagnosis of High-Voltage (HV) equipment. Multi-class classification algorithms are used to classify or distinguish between various discharge sources such as Partial Discharges (PD), Exciter, Arcing, micro Sparking and Random Noise. The signals were measured and recorded on different sites followed by EMI expert’s data analysis in order to identify and label the discharge source type contained within the signal. The classification was performed both within each site and across all sites. The system performs well for both cases with extremely high classification accuracy within site. This work demonstrates the ability to extract relevant entropy-based features from EMI discharge sources from time-resolved signals requiring minimal computation making the system ideal for a potential application to online condition monitoring based on EMI

    A Validity-Based Approach for Feature Selection in Intrusion Detection Systems

    Get PDF
    Intrusion detection systems are tools that detect and remedy the presence of malicious activities. Intrusion detection systems face many challenges in terms of accurate analysis and evaluation. One such challenge is the involvement of many features during analysis, which leads to high data volume and ultimately excessive computational overhead. This research surrounds the development of a new intrusion detection system by employing an entropy-based measure called v-measure to select significant features and reduce dimensionality. After the development of the intrusion detection system, this feature reduction technique was tested on public datasets by applying machine learning classifiers such as Decision Tree, Random Forest, and AdaBoost algorithms. We have compared the results of the features selected with other feature selection techniques for correct classification of attacks. The findings demonstrated dimension and data volume reduction while maintaining low false positive rate, low false negative rate, and high detection rate

    Use of Entropy for Feature Selection with Intrusion Detection System Parameters

    Get PDF
    The metric of entropy provides a measure about the randomness of data and a measure of information gained by comparing different attributes. Intrusion detection systems can collect very large amounts of data, which are not necessarily manageable by manual means. Collected intrusion detection data often contains redundant, duplicate, and irrelevant entries, which makes analysis computationally intensive likely leading to unreliable results. Reducing the data to what is relevant and pertinent to the analysis requires the use of data mining techniques and statistics. Identifying patterns in the data is part of analysis for intrusion detections in which the patterns are categorized as normal or anomalous. Anomalous data needs to be further characterized to determine if representative attacks to the network are in progress. Often time subtleties in the data may be too muted to identify certain types of attacks. Many statistics including entropy are used in a number of analysis techniques for identifying attacks, but these analyzes can be improved upon. This research expands the use of Approximate entropy and Sample entropy for feature selection and attack analysis to identify specific types of subtle attacks to network systems. Through enhanced analysis techniques using entropy, the granularity of feature selection and attack identification is improved

    Combining Data-Driven 2D and 3D Human Appearance Models

    Get PDF
    Detailed 2D and 3D body estimation of humans has many applications in our everyday life: interaction with machines, virtual try-on of fashion or product adjustments based on a body size estimate are just some examples. Two key components of such systems are: (1) detailed pose and shape estimation and (2) generation of images. Ideally, they should use 2D images as input signal so that they can be applied easily and on arbitrary digital images. Due to the high complexity of human appearance and the depth ambiguities in 2D space, data driven models are the tool at hand to design such methods. In this work, we consider two aspects of such systems: in the first part, we propose general optimization and implementation techniques for machine learning models and make them available in the form of software packages. In the second part, we present in multiple steps, how the detailed analysis and generation of human appearance based on digital 2D images can be realized. We work with two machine learning methods: Decision Forests and Artificial Neural Networks. The contribution of this thesis to the theory of Decision Forests consists of the introduction of a generalized entropy function that is efficient to evaluate and tunable to specific tasks and allows us to establish relations to frequently used heuristics. For both, Decision Forests and Neural Networks, we present methods for implementation and a software package. Existing methods for 3D body estimation from images usually estimate the 14 most important, pose defining points in 2D and convert them to a 3D `skeleton'. In this work we show that a carefully crafted energy function is sufficient to recover a full 3D body shape automatically from the keypoints. In this way, we devise the first fully automatic method estimating 3D body pose and shape from a 2D image. While this method successfully recovers a coarse 3D pose and shape, it is still a challenge to recover details such as body part rotations. However, for more detailed models, it would be necessary to annotate data with a very rich set of cues. This approach does not scale to large datasets, since the effort per image as well as the required quality could not be reached due to how hard it is to estimate the position of keypoints on the body surface. To solve this problem, we develop a method that can alternate between optimizing the 2D and 3D models, improving them iteratively. The labeling effort for humans remains low. At the same time, we create 2D models reasoning about factors more items than existing methods and we extend the 3D pose and body shape estimation to rotation and body extent. To generate images of people, existing methods usually work with 3D models that are hard to adjust and to use. In contrast, we develop a method that builds on the possibilities for automatic 3D body estimation: we use it to create a dataset of 3D bodies together with 2D clothes and cloth segments. With this information, we develop a data driven model directly producing 2D images of people. Only the broad interplay of 2D and 3D body and appearance models in different forms makes it possible to achieve a high level of detail for analysis and generation of human appearance. The developed techniques can in principle also be used for the analysis and generation of images of other creatures and objects.Detaillierte 2D und 3D Körperschätzung von Menschen hat vielfältige Anwendungen in unser aller Alltag: Interaktion mit Maschinen, virtuelle "Anprobe" von Kleidung oder direkte Produktanpassungen durch Schätzung der Körpermaße sind nur einige Beispiele. Dazu sind Methoden zur (1) detaillierten Posen- und Körpermaßschätzung und (2) Körperdarstellung notwendig. Idealerweise sollten sie digitale 2D Bilder als Ein- und Ausgabemedium verwenden, damit die einfache und allgemeine Anwendbarkeit gewährleistet bleibt. Aufgrund der hohen Komplexität des menschlichen Erscheinungsbilds und der Tiefenmehrdeutigkeit im 2D Raum sind datengetriebene Modelle ein naheliegendes Werkzeug, um solche Methoden zu entwerfen. In dieser Arbeit betrachten wir zwei Aspekte solcher Systeme: im ersten Teil entwickeln wir allgemein anwendbare Techniken für die Optimierung und Implementierung maschineller Lernmethoden und stellen diese in Form von Softwarepaketen bereit. Im zweiten Teil präsentieren wir in mehreren Schritten, wie die detaillierte Analyse und Darstellung von Menschen basierend auf digitalen 2D Bildern bewerkstelligt werden kann. Wir arbeiten dabei mit zwei Methoden zum maschinellen Lernen: Entscheidungswäldern und Künstlichen Neuronalen Netzen. Der Beitrag dieser Dissertation zur Theorie der Entscheidungswälder besteht in der Einführung einer verallgemeinerten Entropiefunktion, die effizient auswertbar und anpassbar ist und es ermöglicht, häufig verwendete Heuristiken besser einzuordnen. Für Entscheidungswälder und für Neuronale Netze beschreiben wir Methoden zur Implementierung und stellen jeweils ein Softwarepaket bereit, welches diese umsetzt. Die bisherigen Methoden zur 3D Körperschätzung aus Bildern beschränken sich auf die automatische Bestimmung der 14 wichtigsten 2D Punkte, welche die Pose definieren und deren Konvertierung in ein 3D "Skelett" Wir zeigen, dass durch die Optimierung einer fein abgestimmten Energiefunktion auch ein voller 3D Körper, nicht nur dessen Skelett, aus automatisch bestimmten 14 Punkten geschätzt werden kann. Damit beschreiben wir die erste vollautomatische Methode, die einen 3D Körper aus einem digitalen 2D Bild schätzt. Die detaillierte 3D Pose, beispielsweise mit Rotationen der Körperteile und die Beschaffenheit des untersuchten Körpers, ist damit noch nicht bestimmbar. Um detailliertere Modelle zu erstellen wäre es notwendig, Daten mit einem hohen Detailgrad zu annotieren. Dies skaliert jedoch nicht zu großen Datenmengen, da sowohl der Zeitaufwand pro Bild, als auch die notwendige Qualität aufgrund der schwierig einzuschätzenden exakten Positionen von Punkten auf der Körperoberfläche nicht erreicht werden können. Um dieses Problem zu lösen entwickeln wir eine Methode, die zwischen der Optimierung der 2D und 3D Modelle alterniert und diese wechselseitig verbessert. Dabei bleibt der Annotationsaufwand für Menschen gering. Gleichzeitig gelingt es, 2D Modelle mit einem Vielfachen an Details bisheriger Methoden zu erstellen und die Schätzung der 3D Pose und des Körpers auf Rotationen und Körperumfang zu erweitern. Um Bilder von Menschen zu generieren, beschränken sich existierende Methoden auf 3D Modelle, die schwer anzupassen und zu verwenden sind. Im Gegensatz dazu nutzen wir in dieser Arbeit einen Ansatz, der auf den Möglichkeiten zur automatischen 3D Posenschätzung basiert: wir nutzen sie, um einen Datensatz aus 3D Körpern mit dazugehörigen 2D Kleidungen und Kleidungssegmenten zu erstellen. Dies erlaubt es uns, ein datengetriebenes Modell zu entwickeln, welches direkt 2D Bilder von Menschen erzeugt. Erst das vielfältige Zusammenspiel von 2D und 3D Körper- und Erscheinungsmodellen in verschiedenen Formen ermöglicht es uns, einen hohen Detailgrad sowohl bei der Analyse als auch der Generierung menschlicher Erscheinung zu erzielen. Die hierfür entwickelten Techniken sind prinzipiell auch für die Analyse und Generierung von Bildern anderer Lebewesen und Objekte anwendbar

    Entropic Analysis of Votes Expressed in Italian Elections between 1948 and 2018

    Get PDF
    In Italy, the elections occur often, indeed almost every year the citizens are involved in a democratic choice for deciding leaders of different administrative entities. Sometimes the citizens are called to vote for filling more than one office in more than one administrative body. This phenomenon has occurred 35 times after 1948; it creates the peculiar condition of having the same sample of people expressing decisions on political bases at the same time. Therefore, the Italian contemporaneous ballots constitute the occasion to measure coherence and chaos in the way of expressing political opinion. In this paper, we address all the Italian elections that occurred between 1948 and 2018. We collect the number of votes per party at each administrative level and we treat each election as a manifestation of a complex system. Then, we use the Shannon entropy and the Gini Index to study the degree of disorder manifested during different types of elections at the municipality level. A particular focus is devoted to the contemporaneous elections. Such cases implicate different disorder dynamics in the contemporaneous ballots, when different administrative level are involved. Furthermore, some features that characterize different entropic regimes have emerged

    Adaptive sequential feature selection in visual perception and pattern recognition

    Get PDF
    In the human visual system, one of the most prominent functions of the extensive feedback from the higher brain areas within and outside of the visual cortex is attentional modulation. The feedback helps the brain to concentrate its resources on visual features that are relevant for recognition, i. e. it iteratively selects certain aspects of the visual scene for refined processing by the lower areas until the inference process in the higher areas converges to a single hypothesis about this scene. In order to minimize a number of required selection-refinement iterations, one has to find a short sequence of maximally informative portions of the visual input. Since the feedback is not static, the selection process is adapted to a scene that should be recognized. To find a scene-specific subset of informative features, the adaptive selection process on every iteration utilizes results of previous processing in order to reduce the remaining uncertainty about the visual scene. This phenomenon inspired us to develop a computational algorithm solving a visual classification task that would incorporate such principle, adaptive feature selection. It is especially interesting because usually feature selection methods are not adaptive as they define a unique set of informative features for a task and use them for classifying all objects. However, an adaptive algorithm selects features that are the most informative for the particular input. Thus, the selection process should be driven by statistics of the environment concerning the current task and the object to be classified. Applied to a classification task, our adaptive feature selection algorithm favors features that maximally reduce the current class uncertainty, which is iteratively updated with values of the previously selected features that are observed on the testing sample. In information-theoretical terms, the selection criterion is the mutual information of a class variable and a feature-candidate conditioned on the already selected features, which take values observed on the current testing sample. Then, the main question investigated in this thesis is whether the proposed adaptive way of selecting features is advantageous over the conventional feature selection and in which situations. Further, we studied whether the proposed adaptive information-theoretical selection scheme, which is a computationally complex algorithm, is utilized by humans while they perform a visual classification task. For this, we constructed a psychophysical experiment where people had to select image parts that as they think are relevant for classification of these images. We present the analysis of behavioral data where we investigate whether human strategies of task-dependent selective attention can be explained by a simple ranker based on the mutual information, a more complex feature selection algorithm based on the conventional static mutual information and the proposed here adaptive feature selector that mimics a mechanism of the iterative hypothesis refinement. Hereby, the main contribution of this work is the adaptive feature selection criterion based on the conditional mutual information. Also it is shown that such adaptive selection strategy is indeed used by people while performing visual classification.:1. Introduction 2. Conventional feature selection 3. Adaptive feature selection 4. Experimental investigations of ACMIFS 5. Information-theoretical strategies of selective attention 6. Discussion Appendix Bibliograph
    corecore