Avtonomna segmentacija slik z Markovim slučajnim poljem

Segmentacija slik je zelo raziskovano področje, za katero so na voljo številni algoritmi. Naš cilj je segmentacija slike s pomočjo superpikslov na več skladnih delov in na nenadzorovan način. Da bi to dosegli, predlagamo iterativni segmentacijski algoritem. Algoritem predstavlja sliko kot slučajno polje Markova (MRF), katerega vozlišča so superpiksli, ki imajo barvne in teksturne atribute. Superpikslom dodelimo oznake na podlagi njihovih atributov s pomočjo metode podpornih vektorjev (SVM) in že omenjenega MRF in iterativno zmanjšujemo število segmentov. Negotovo segmentacijo po vsaki iteraciji se izboljšuje in rezultat je segmentacija slike na več semantično smiselnih delov, brez pomoči uporabnika. Algoritem je bil testiran na segmentacijsko podatkovno bazo in F ocene so podobne najsodobnejšim algoritmom. Glede fragmentacije slike naš pristop bistveno prekosi stanje tehnike z zmanjšanjem števila segmentov, iz katerih je sestavljen predmet zanimanja.Image segmentation is a widely-researched topic with many algorithms available. Our goal is to segment an image, in an unsupervised way, into several coherent parts with the help of superpixels. To achieve that, we propose an iterative segmentation algorithm. The algorithm models the image by a Markov random field, whose nodes are the superpixels, and each node has both color and texture features. The superpixels are assigned labels according to their features with the help of support vector machines and the aforementioned MRF and the number of segments is iteratively reduced. The result is a segmentation of an image into several regions with requiring any user input. The segmentation algorithm was tested on a standard evaluation database, and performs on par with state-of-the-art segmentation algorithms in F-measures. In terms of oversegmentation, our approach significantly outperforms the state of the art by greatly reducing the oversegmentation of the object of interest

Modelling multivariate discrete data with latent Gaussian processes

Multivariate count data are common in some fields, such as sports, neuroscience, and text mining. Models that can accurately perform factor analysis are required, especially for structured data, such as time-series count matrices. We present Poisson Factor Analysis using Latent Gaussian Processes, a novel method for analyzing multivariate count data. Our approach allows for non-i.i.d observations, which are linked in the latent space using a Gaussian Process. Due to an exponential non-linearity in the model, there is no closed form solution. Thus, we resort to an expectation maximization approach with a Laplace approximation for tractable inference. We present results on several data sets, both synthetic and real, of a comparison with other factor analysis methods. Our method is both qualitatively and quantitatively superior for non-i.i.d Poisson data, because the assumptions it makes are well suited for the data

Gradient estimation for discrete variables via dependent Monte Carlo samples

Discrete expectations arise in various machine learning tasks, and we often need to backpropagate the gradient through them. One domain is variational inference, where training discrete latent variable models requires gradient estimates of a high dimensional discrete distribution because we are backpropagating through discrete stochastic layer in a deep neural network. Another important area of research is a permutation or ranking based objective where the objective itself is discrete and non-differentiable. To tackle these problems, we propose ARMS, an antithetic REINFORCE-based Monte Carlo gradient estimator for three different discrete distributions: binary, categorical, and Plackett-Luce, where the last two are generalizations of the previous case. ARMS uses negatively correlated samples produced by a copula for variance reduction, and leverages importance sampling to produce an unbiased estimate. Our approach also generalizes several other estimators. ARMS with two samples reduces to the recently developed DisARM estimator for binary and categorical distributions, and ARMS with independent samples reduces to the strong self-control baseline LOORF/VarGrad. We evaluate ARMS on several different objectives and datasets. We show that ARMS outperforms the state of the art on training variational autoencoders with binary or categorical latent variables, trained using either the evidence lower bound or the multi sample bound. We also compare our approach on a structured prediction task for training stochastic categorical networks. Lastly, we evaluate ARMS for different Plackett-Luce based objectives, which include permutation and ranking losses, with similar results, and we open source the code publicly.Information, Risk, and Operations Management (IROM

Waiting for the Godot of reading

Izraz ‘kriza čitanja filozofije’ sasvim sigurno izražava stanje svijesti o filozofiji i unutar nje, a još više način njezina čitanja od ponuđene nam kritike tumačenja i vrjednovanja. Za nju se navodi da ispisuje načine za iščitavanje svijeta iz kojeg bi iščitavač došao ne samo do sebe, već i do onoga što treba kao odgovor za ostvarenje sebe u svijetu. Jednu problemsku točku rasprave o krizi čitanja pronalazimo u aklamativnom prihvaćanju ili odbijanju napisanog i objavljenog, već prema senzibilitetu iščitavača u odnosu prema važećoj ideologiji. Također, u radu se tematizira i odgovornost kritičara filozofskih tekstova prema čitateljskoj publici, koja, kako rad ističe, i sama pati od nedostatka »pismenosti čitanja«. Kriza čitanja, u prvome redu filozofskih tekstova, u tekstu se razmatra kao slojevita pojava čiji su se elementi mogli samo naznačiti i predstavljaju osnovu za dalja promišljanja.The expression ‘a crisis of reading philosophy’ is most certainly an expression of the state of consciousness of an in philosophy. Moreover, it is a way of reading it by the criticism of interpretation and appraisal on offer. Philosophy is held to be writing ways of reading the world, from which its readers would arrive not only at themselves, but also at that which they need as a response to the realisation of themselves in the world. One of the problems concerning the crisis of reading has been identified in the acclamatory acceptance or rejection of the written and published, depending on the readers’ sensibilities in relation to the predominant ideology. This paper also deals with the responsibility of critics of philosophical texts to readers, who also suffer from a deficiency in “reading literacy”. The authors tackle this crisis of reading (mostly philosophy) as a layered phenomenon, whose elements have only been pointed at and represent a basis for further reflection

Waiting for the Godot of reading

Izraz ‘kriza čitanja filozofije’ sasvim sigurno izražava stanje svijesti o filozofiji i unutar nje, a još više način njezina čitanja od ponuđene nam kritike tumačenja i vrjednovanja. Za nju se navodi da ispisuje načine za iščitavanje svijeta iz kojeg bi iščitavač došao ne samo do sebe, već i do onoga što treba kao odgovor za ostvarenje sebe u svijetu. Jednu problemsku točku rasprave o krizi čitanja pronalazimo u aklamativnom prihvaćanju ili odbijanju napisanog i objavljenog, već prema senzibilitetu iščitavača u odnosu prema važećoj ideologiji. Također, u radu se tematizira i odgovornost kritičara filozofskih tekstova prema čitateljskoj publici, koja, kako rad ističe, i sama pati od nedostatka »pismenosti čitanja«. Kriza čitanja, u prvome redu filozofskih tekstova, u tekstu se razmatra kao slojevita pojava čiji su se elementi mogli samo naznačiti i predstavljaju osnovu za dalja promišljanja.The expression ‘a crisis of reading philosophy’ is most certainly an expression of the state of consciousness of an in philosophy. Moreover, it is a way of reading it by the criticism of interpretation and appraisal on offer. Philosophy is held to be writing ways of reading the world, from which its readers would arrive not only at themselves, but also at that which they need as a response to the realisation of themselves in the world. One of the problems concerning the crisis of reading has been identified in the acclamatory acceptance or rejection of the written and published, depending on the readers’ sensibilities in relation to the predominant ideology. This paper also deals with the responsibility of critics of philosophical texts to readers, who also suffer from a deficiency in “reading literacy”. The authors tackle this crisis of reading (mostly philosophy) as a layered phenomenon, whose elements have only been pointed at and represent a basis for further reflection