LOSSGRAD: automatic learning rate in gradient descent

In this paper, we propose a simple, fast and easy to implement algorithm LOSSGRAD (locally optimal step-size in gradient descent), which automatically modifies the step-size in gradient descent during neural networks training. Given a function $f$, a point $x$, and the gradient $\nabla_x f$ of $f$, we aim to find the step-size $h$ which is (locally) optimal, i.e. satisfies: $$h=arg\,min_{t \geq 0} f(x-t \nabla_x f).$$ Making use of quadratic approximation, we show that the algorithm satisfies the above assumption. We experimentally show that our method is insensitive to the choice of initial learning rate while achieving results comparable to other methods.Comment: TFML 201

Effect of the grinding process after strengthening the aluminum alloy surface layer on the surface roughness.

W opracowaniu przedstawiono fragment badań warstw wierzchnich obejmujących rozkłady chropowatości pomierzone na stopie aluminium których powierzchnie poddano procesowi umocnienia. Celem procesu szlifowania było zmniejszenie chropowatości kosztem usunięcia niewielkich grubości warstw umocnionych, pozwalających zachować właściwą wytrzymałość zmęczeniową. Zastosowano mgłę olejową oraz sprężone powietrze jako czynniki smarujące i chłodzące. Sprawdzono wpływ tych mediów na stan sił skrawania.The paper presents the research portion of the outer layers covering the roughness distributions measured on the aluminum alloy surfaces which were subjected to strengthen. The purpose of the grinding process was to reduce the roughness of the cost of removal of small layer thickness reinforced, allowing maintain proper fatigue resistance. And oil mist used compressed air as cooling and lubricating agents. Checked the effect of these media on the condition of the cutting forces

LIMITING VALUE OF COCKROFT-LATHAM INTEGRAL FOR COMMERCIAL PLASTICINE

The paper presents the results of experimental and numerical research in the scope of commercial plasticine cracking. The purpose of the study was to determine the limit value of the Cockroft-Latham integral. The value of the integral was determined on the basis of the stretching test and computer simulations. Experimental studies utilized axially symmetrical samples made of commercial black and white wax based plasticine. Samples were cooled to 0, 5, 10, 15 and 20 °C. After the completion of experimental studies, finite element numerical simulation was performed under the conditions of 3-dimensional state of deformation in DEFORM 3D simulation software. Based on the results of experimental and numerical studies, the Cockroft-Latham limit value was calculated

Coexistence, cooperation, and competition between banks and non-banking entities

Financial stability is essential for the functioning of the economy, and competition between banks is seen as an essential factor for their stability. Reframing the conflict and each party’s goals in such a way that they are mutually dependent increases a party’s chances of reaching an agreement. This study investigates the relationship between bank size and the institution’s stability. Government regulators and anyone else’s ability to keep an eye on the entire financial system is jeopardized when large portions of it are left largely unregulated. Price competition (marginal-cost pricing) reduces the market power of a single firm as the number of firms in an industry grows. Since the 1990s, the banking industry, according to previous studies, has been experiencing concentration and competition. Some argue that the lack of technology in small banks may put them at an advantage in terms of customer satisfaction, but this is not necessarily the case

Comparative analysis of reactions to visual and auditory stimuli in research on EEG evoked potentials

The paper describes results of comparison of reactions times to visual and auditory stimuli using EEG evoked potentials. Two experiments were used to applied. The first one explored reaction times to visual stimulus and the second one to auditory stimulus. After conducting an analysis of data, received results enable determining that visual stimuli evoke faster reactions than auditory stimuli

Numerical analysis of EM estimation of mixture model parameters

Optimisation of distribution parameters is a very common problem. There are many sorts of distributions which can be used to model environment processes, biological functions or graphical data. However, it is common that parameters of those distribution may be, partially or completely unknown. Mixture models composed of a few distributions are easier to solve. In such a case simple estimation methods may be used to obtain results. Usually models are composed of several distributions. Those distributions may be of the same or different type. Such models are called mixture models. Finding their parameters may be complicated. Usually in such cases iterative methods need to be used. The paper gives a brief survey of algorithms designed for solving mixtures of distributions and problems connected with their usage.One of the most common method used to obtain mixture model parameters is Expectation-Maximization (EM) algorithm. EM is the iterative algorithm performing maximum likelihood estimation. The authors present the results of adjusting the Gaussian mixture models to the data. It is done with the usage of EM algorithm. The article gives advantages and disadvantages of EM algorithm. Improvements of EM applied in the case of large data are also presented. They help increase efficiency and decrease operation time of the algorithm. Another considered issue is the problem of optimal input parameters selection and its influence on the adjustment results. The authors also present algorithm performance observations

NOWY ALGORYTM HYBRYDOWY WYKORZYSTUJĄCY AUTOENKODER KONWOLUCYJNY Z SVM DLA ELEKTRYCZNEJ TOMOGRTAFII IMPEDANCYJNEJ I TOMOGRAFII ULTRADŹWIĘKOWEJ

This paper presents a new hybrid algorithm using multiple Support Vector Machines models with convolutional autoencoder to Electrical Impedance Tomography, and Ultrasound Computed Tomography image reconstruction. The ultimate hybrid solution uses multiple SVM models to convert input measurements to individual autoencoder codes representing a given scene then the decoder part of the autoencoder can reconstruct the sceneArtykuł przedstawia nowy hybrydowy algorytm który używa modeli maszyn wektorów nośnych wraz z autoenkoderem konwolucyjnym do rekonstrukcji obrazu z Elektrycznej Tomografii Impedancyjnej oraz Ultrasonograficznej Tomografii Transmisyjnej. Ostateczne rozwiązanie hybrydowe używa wielu modeli SVM do konwersji pomiarów wejściowych do pojedynczych kodów autoenkodera reprezentujących daną scenę a wtedy dekoder wycięty z autoenkodera może zrekonstruować daną scen

Atypical regressive corneal endothelial cysts in long-term confocal follow-up

Corneal endothelium is formed of 1 layer of mitochondria-rich cubic cells whose main role is to maintain corneal transparency. Corneal endothelial disorders represent group of both inherited and noninherited and may affect proper vision. A 36-year-old male patient with suspicion of corneal endothelial dystrophy underwent visual acuity, intraocular pressure, the basic slit-lamp examination, anterior segment optical coherence tomography (AS-OCT) (Visante, Carl Zeiss Meditec, Dublin, CA), and corneal confocal microscopy in vivo (Rostock Cornea Module, Heidelberg Engineering Retina Tomograph III, Heidelberg, Germany). During the 3-year observation the patient reported symptoms mainly in the right eye. Slit-lamp examination revealed endothelial changes, much more pronounced in the right eye. Examination by the AS-OCT Visante showed hyperreflective dots within the right corneal endothelium. In order to assess endothelial cell morphology, analysis using corneal confocal microscopy in vivo was performed. Scans revealed presence of single endothelial deposits and severe cell changes of different morphology in both eyes. In the right eye, less pronounced changes of the polymorphic structure-polygonal guttas in different stages, linear and branched loss with "nuclear-like" formations and accompanying sediments. In the left eye, severe homomorphous polygonal "guttas-like" changes with "nuclear-like" formations were observed. Endothelial cysts' features were dynamically changing during follow-up time with different effects on the patient's clinical state. Corneal confocal microscopy allows accurate imaging of the endothelial cells and their detailed characteristics. Structural changes within the endothelial cells are not always proportional to visual acuity and slit-lamp image. The presented case is an example of an unusual corneal endothelial syndrome with probably nondystrophic background due to observed dynamic state with regressive tendency

FEM and Experimental Based Analysis of the Stamping Process of Aluminum Alloy

The subject of the study was aluminum samples of varying thickness. The aim of the study was to perform the experimental stamping process of the samples on a universal testing machine and a numerical analysis on two independent computer systems Abaqus® and Deform-3D. As part of the numerical analysis, bilinear material model was included, taking into account elastic and plastic characteristics. The study was conducted in a dynamic environment with geometric nonlinearity. The results obtained from experimental research were confronted with those obtained by FEM computer simulation. During the research, numerical model of the stamping process has been developed, which was validated with the results of experimental research

COMPARISON OF NUMERICAL AND EXPERIMENTAL ANALYSIS OF THE CRACK PROPAGATION PROCESS

Nowadays numerical methods are a powerful tool to simulate real processes. Polymer materials are increasingly used in engineering solutions. ABS is a common material used interchangeably with respect to traditional materials. Process for the production of components for rese-arch on 3D printers is becoming more widespread and accessible to ordi-nary users. Crack propagation process was carried out at the same time to compare results through experiments performed on the testing machine and numerical study. Cracking process was carried out by finite element method, implemented on the basis of simulations xFEM. This method allows to conduct research related to the separation of the material nodes, in places of highest stress levels that exceed the limits of plasticity and strength of the material. The analysis involved comparison of the shape of the resulting cracks through experimental and numerical way