29 research outputs found
A new 2D Hénon-logistic map for producing hyperchaotic behavior
Derived from the two-dimensional (2D) Hénon map and the one-dimensional (1D) Logistic map, this paper proposes a new 2D hyperchaotic map, called the 2D Hénon-Logistic map (2D-HLM). The dynamics of the 2D-HLM are investigated by means of equilibria, stability analysis, trajectory, Lyapunov exponent, and bifurcation diagram. Mathematical analysis reveals that the 2D-HLM has four unstable equilibria. Besides that, it has wide chaotic and hyperchaotic behaviors with very limited periodic windows. To evaluate the complexity performance of the 2D-HLM, Approximate entropy is used to analyze its time series. Consequently, the 2D-HLM exhibits extremely complex nonlinear behavior. With all of these attributes, the 2D-HLM would be very appropriate to produce a pseudo-random number generator that can be used in chaos-based cryptographic applications
Enhancing chaos in multistability regions of Duffing map for an asymmetric image encryption algorithm
We investigate the dynamics of a two-dimensional chaotic Duffing map which
exhibits the occurrence of coexisting chaotic attractors as well as periodic
orbits with a typical set of system parameters. Such unusual behaviors in
low-dimensional maps is inadmissible especially in the applications of chaos
based cryptography. To this end, the Sine-Cosine chaotification technique is
used to propose a modified Duffing map in enhancing its chaos complexity in the
multistable regions. Based on the enhanced Duffing map, a new asymmetric image
encryption algorithm is developed with the principles of confusion and
diffusion. While in the former, hyperchaotic sequences are generated for
scrambling of plain-image pixels, the latter is accomplished by the elliptic
curves, S-box and hyperchaotic sequences. Simulation results and security
analysis reveal that the proposed encryption algorithm can effectively encrypt
and decrypt various kinds of digital images with a high-level security.Comment: 15 pages, 15 figure
A Proposed Approach for Object Detection and Recognition by Deep Learning Models Using Data Augmentation
Object detection and recognition play a crucial role in computer vision applications, ranging from security systems to autonomous vehicles. Deep learning algorithms have shown remarkable performance in these tasks, but they often require large, annotated datasets for training. However, collecting such datasets can be time-consuming and costly. Data augmentation techniques provide a solution to this problem by artificially expanding the training dataset. In this study, we propose a deep learning approach for object detection and recognition that leverages data augmentation techniques. We use deep convolutional neural networks (CNNs) as the underlying architecture, specifically focusing on popular models such as You Only Look Once version 3 (YOLOv3). By augmenting the training data with various transformations, such as rotation, scaling, and flipping, we can effectively increase the diversity and size of the dataset. Our approach not only improves the robustness and generalization of the models but also reduces the risk of overfitting. By training on augmented data, the models can learn to recognize objects from different viewpoints, scales, and orientations, leading to improved accuracy and performance. We conduct extensive experiments on benchmark datasets and evaluate the performance of our approach using standard metrics such as precision, recall, and mean average precision (mAP). The experimental results demonstrate that our data augmentation-based deep learning approach achieves superior object detection and recognition accuracy compared to traditional training methods without data augmentation. We compare the average accuracy of the YOLOv3-SPP model with two other variants of the YOLOv3 algorithm: one with a feature extraction network consisting of 53 convolutional layers and the other with 13 convolutional layers. The average accuracy of the proposed model (YOLOv3-SPP) is reported as accuracy of 97%, F1-score of 96%, precision of 94%, and average Intersection over Union (IoU) of 78.04%
Comparing the Quality of Life among Patients with Relapsing Remitting Multiple Sclerosis in Iraq Using Different Disease Modifying Therapies
Multiple sclerosis (MS) is a chronic, inflammatory, immune mediated disease of the central nervous system, mostly affecting young adults with mean age of 30 years, twice as high in women compared to men. The etiology of MS is not fully elucidated. MS symptoms are directly related to demyelination and axonal loss, along with other psychological symptoms, can result in functional limitations, disability and reduced quality of life (QoL). The QoL assessments in patients with a chronic disease may contribute to improving treatment and could even be of prognostic value. The goals of this study were to compare the QoL of Iraqi patients with relapsing remitting multiple sclerosis (RRMS),using three different diseases modifying therapies(DMTs) administered orally, subcutaneously, and by slow infusion; namely, fingolimod,interferonB-1b, and natalizumab, respectively. And to assess the role of disability status, educational status, occupational status, MS duration, and treatment duration as a predictor for the QoL. Functional Assessment of Multiple Sclerosis (FAMS) questionnaire version 4 was used to assess QoL. Sociodemographic and clinical characteristics were tested by univariate and multivariate regression analyses to assess the contribution of these predictors to QoL. No significant differences were found in symptoms, thinking/fatigue subscales and FAMS total scores among the three DMTs. In conclusion: Iraqi MS patients using InterferonB-1b, fingolimod or natalizumab have a comparable low level of QoL. The expanded disability status scale (EDSS) is negatively associated with QoL of MS patients in all of the three therapies, while other predictors such as occupational status, educational status, smoking habit and MS duration have different impact in different treatments
The Relationship between P-Wave Morphology and Atrial Fibrillation
The objective of this paper is to develop an efficient P-wave detection algorithm based on the morphology characteristics of arrhythmias using time domain analysis.
ECG from normal subjects, and patients with atrial fibrillation were studied. After baseline wander cancellation, power line interference filtration, the step of QRS detection using the pan- Tompkins algorithm is utilized to calculate R peak which represent the reference point to detect P peak.
The algorithm was tested with experiments using MIT-BIH arrhythmia database which included Paroxysmal Atrial Fibrillation PAF prediction challenge, Massachusetts Institute of Technology MIT-BIH normal sinus rhythm, long term Atrial Fibrillation AF and MIT-BIH atrial fibrillation where every P-wave was extracted.
The results reveal that the algorithm is accurate and efficient to detect and classify arrhythmias resulted from atrial fibrillation
A Chaotic Quadratic Oscillator with Only Squared Terms: Multistability, Impulsive Control, and Circuit Design
Here, a chaotic quadratic oscillator with only squared terms is proposed, which shows various dynamics. The oscillator has eight equilibrium points, and none of them is stable. Various bifurcation diagrams of the oscillator are investigated, and its Lyapunov exponents (LEs) are discussed. The multistability of the oscillator is discussed by plotting bifurcation diagrams with various initiation methods. The basin of attraction of the oscillator is discussed in two planes. Impulsive control is applied to the oscillator to control its chaotic dynamics. Additionally, the circuit is implemented to reveal its feasibility
Matematyczne modele hydromechaniki przepływu wielofazowego o zmiennej masie
The paper discusses the mathematical model of hydromechanics of multiphase flows with varying mass. A multiphase flow is considered a continuum consisting of a set of a large number of different groups of particles. The derivation of motion equations and similarity criteria are given taking into account both the externally attached (or detached) mass and phase transitions within the medium. The equations of mass, momentum and energy transfer for individual phases and the medium as a whole are derived based on fundamental conservation laws. It was demonstrated that in the absence of sources (or flow-offs) of mass, momentum and energy, the known equations of single- and multi-phase flow hydromechanics follow as a special case from the obtained systems of motion equations and similarity criteria. The obtained motion equations are valid for the description of an ingredient of mixture and the medium as a whole, regardless of their physical and mechanical properties. Thermodynamic and rheological state equations, as well as expressions for heat flow, interfacial mass forces phase transitions, and heat exchange between phases can be used to close them. The implemented models make it possible to simulate both the stationary distribution of parameters along the wellbore during production and non-stationary processes that occur, for example, when the pump shaft speed changes during oil production. The developed approaches were implemented in the DataFlow software tool for analysis of the hydrodynamics of multiphase hydrocarbon flows, taking into account heat exchange with the rocks surrounding the well, and phase transitions in the fluid. Using the software package, test calculations were carried out to demonstrate the performance of the proposed and implemented models.W artykule omówiono model matematyczny hydromechaniki przepływów wielofazowych o zmiennej masie. Przepływ wielofazowy jest traktowany jako kontinuum składające się ze zbioru dużej liczby różnych grup cząstek. Wprowadzone równania ruchu i kryteria podobieństwa są podane z uwzględnieniem zarówno zewnętrznej dołączonej (lub odłączonej) masy, jak i przejść fazowych wewnątrz ośrodka. Równania transferu masy, pędu i energii dla poszczególnych faz i ośrodka jako całości otrzymano przy użyciu podstawowych praw zachowania. Wykazano, że w przypadku braku źródeł (lub wypływów) masy, pędu i energii, znane równania hydromechaniki przepływu jedno- i wielofazowego wynikają jako szczególny przypadek z otrzymanych układów równań ruchu i kryteriów podobieństwa. Uzyskane równania ruchu mają zastosowanie do opisu składnika mieszaniny i medium jako całości, niezależnie od ich właściwości fizycznych i mechanicznych. Do ich rozwiązania można wykorzystać termodynamiczne i reologiczne równania stanu, a także wyrażenia dotyczące przepływu ciepła, siły międzyfazowych masy, przejść fazowych i wymiany ciepła między fazami. Wdrożone modele umożliwiają symulację zarówno stacjonarnego rozkładu parametrów wzdłuż odwiertu podczas wydobycia, jak i procesów niestacjonarnych, które zachodzą na przykład podczas zmiany prędkości wału pompy w trakcie wydobycia ropy. Opracowane podejścia zostały zaimplementowane w oprogramowaniu DataFlow do analizy hydrodynamiki wielofazowych przepływów węglowodorów, z uwzględnieniem wymiany ciepła ze skałami otaczającymi odwiert oraz przejść fazowych w płynie. Za pomocą pakietu oprogramowania przeprowadzono obliczenia testowe w celu wykazania wydajności proponowanych i wdrożonych modeli
Characterizing noise-induced chaos and multifractality of a finance system
In this article, noise induced chaos is investigated for a finance system. To characterize chaotic paradigm, period analysis is done with the variation of a parameter and noise strength. Later on, chaos has been quantified by 0–1 tests under the same variation. A phase space analysis is also done to investigate the effect of noise on the system dynamics. However, we have noticed that the respective asymptotic dynamics of the deterministic and noise induced chaos are very similar. To classify chaos between noisy and noise free systems, multifractal analysis is then performed. Though the phase spaces are showing similar trajectories, the multifractal analysis confirms more complex dynamics of the noise induced system in compare to the deterministic model. This investigation is an application of multifractal analysis, in case of quantifying chaos
Zastosowanie programowania nieliniowego dla konfiguracji systemu wymiany ciepła w aparatach kolumnowych przemysłu petrochemicznego przy minimalnych kosztach
For increasing the efficiency of heat transfer processes, the layer-by-layer concept of arrangement of various types of packings in column apparatuses is considered. The results of hydraulic tests of a dry and irrigated cell packing, as well as individual hydraulic tests of a mesh packing, are presented. Methods and algorithms for solving linear programming problems under “uncertainty” conditions were considered. However, in some areas of science it is often difficult or impossible to formalize the problem in an appropriate way and reduce it to a linear programming problem. In this paper, methods for solving non-linear programming problems with a vector objective function are considered. At present, the use of non-linear programming in the vast majority of real situations is reduced to linear approximation models. Along with this, at a significant non-linearity, due to its specificity or influence on the nature of the model, it is necessary to apply optimization methods that are much more complex than, for example, the simplex method. However, the importance of non-linear programming is constantly increasing. This is due to the rapidly growing knowledge of managers and specialists in the use of mathematical models designed to prepare solutions, as well as the increasing availability of computer programs for solving large-scale nonlinear problems. The analysis and studies of the hydrodynamics of a number of regular packings have shown that cell and mesh packings are promising for the implementation of the phase inversion mode. The proposed concept of intensifying heat transfer processes in column apparatuses is based on the use of layers of various packings arranged in the following order in the apparatus, type 1 – cell, type 2 – mesh. At the same time, their main geometric characteristics differ significantly from each other. However, the structure of the bulk packing is inhomogeneous, which makes it difficult to implement a stable mode of local phase inversion under these conditions. This is due to the structure of column apparatuses with bulk packing, in which there is an increased proportion of pores (porosity) near the walls of the apparatus. Porosity is very significant; it can reach up to 40%, and as a result, the local velocity near the walls exceeds the velocity in the centre of the apparatus by up to 70%. By contrast, the use of regular packing structures makes this potentially highly efficient mode technically possible.W celu zwiększenia efektywności procesów wymiany ciepła rozważa się koncepcję warstwowego rozmieszczenia różnego rodzaju pakietów w aparatach kolumnowych, warstwa po warstwie. Przedstawiono wyniki badań hydraulicznych suchego i nawodnionego upakowania komórkowego oraz indywidualne badania hydrauliczne upakowania sieciowego. Uwzględniono metody i algorytmy dla rozwiązywania problemów programowania liniowego w warunkach „niepewności”. Jednakże, w niektórych dziedzinach nauki często trudne lub niemożliwe jest sformalizowanie problemu w odpowiedni sposób i zredukowanie go do problemu programowania liniowego. W niniejszym artykule uwzględniono metody rozwiązywania problemów programowania nieliniowego z wektorową funkcją celu. Zastosowanie programowania nieliniowego w znacznej większości rzeczywistych sytuacji jest obecnie zredukowane do modeli aproksymacji liniowej. Wraz z tym, przy znaczącej nieliniowości, ze względu na jej specyfikę lub wpływ na charakter modelu, konieczne jest zastosowanie metod optymizacji, które są o wiele bardziej złożone niż na przykład metoda sympleksów. Jednakże, znaczenie programowania nieliniowego stale rośnie. Wynika to z szybko rosnącej wiedzy kadry zarządzającej i specjalistów od stosowania modeli matematycznych zaprojektowanych do przygotowywania rozwiązań, jak również zwiększającą się dostępnością programów komputerowych do rozwiązywania wielkoskalowych problemów nieliniowych. Analiza i badania hydrodynamiki pewnej liczby upakowań regularnych pokazały, że upakowania komórkowe i sieciowe są obiecujące dla realizacji trybu odwrócenia fazy. Zaproponowana koncepcja zintensyfikowania procesów wymiany ciepła w aparatach kolumnowych oparta jest o zastosowanie warstw różnych upakowań ułożonych w następującej kolejności w aparacie: typ 1 – komórka, typ 2 – sieć. Jednocześnie ich główne cechy geometryczne znacznie różnią się od siebie. Jednakże, struktura upakowania luźnego jest niejednorodna, co utrudnia realizację stabilnego trybu lokalnego odwrócenia fazy w tych warunkach. Jest to spowodowane strukturą aparatów kolumnowych z upakowaniem luźnym, w których blisko ścian aparatu istnieje zwiększony udział porów (porowatość). Porowatość jest bardzo znacząca; może sięgać do 40%, a w efekcie lokalna prędkość blisko ścian przekracza prędkość w środku aparatu o wartość do 70%. Dla odmiany, zastosowanie regularnych struktur upakowania czyni ten potencjalnie wysoce wydajny tryb technicznie możliwym