This paper reviews a class of methods to perform causal inference in the framework of a structural vector autoregressive model. We consider three different settings. In the first setting the underlying system is linear with normal disturbances and the structural model is identified by exploiting the information incorporated in the partial correlations of the estimated residuals. Zero partial co...

Unsupervised kernel regression (UKR), the unsupervised counterpart of the Nadaraya-Watson estimator, is a dimension reduction technique for learning of low-dimensional manifolds. It is based on optimizing representative low-dimensional latent variables with regard to the data space reconstruction error. The problem of scaling initial local linear embedding solutions, and optimization in latent ...

The Linear Search Problem is studied from the view point of Hamiltonian dynamics. For the specific, yet representative case of exponentially distributed position of the hidden object, it is shown that the optimal orbit follows an unstable separatrix in the associated Hamiltonian system.

the purpose of this paper is to studying nonlinear k-ε turbulence models and its advantages in internal combustion engines, since the standard k-ε model is incapable of representing the anisotropy of turbulence intensities and fails to express the reynolds stresses adequately in rotating flows. therefore, this model is not only incapable of expressing the anisotropy of turbulence in an engine c...

Using semantics to guide ATP systems is an under-utilised technique [10]. Two systems that have successfully employed semantic guidance are CLIN-S [1] and SCOTT [5]. In linear deduction, semantic guidance has received only limited attention, e.g., [7, 8]. Our research is developing semantic guidance for linear deduction in the Model Elimination (ME) [3] paradigm. Search pruning, at the possible...

several semantic image search schemes have been recently proposed to retrieve images from the web. however, the query context is regularly ignored in these techniques and hence, many of the returned images are not adequately relevant. in this paper, we make use of context to further confine the outcome of the semantic search engines. for this purpose, we propose a hybrid search engine which uti...

Already in his Lectures on Search Renyi suggested to consider a search problem, where an unknown x ∈ X = {1, 2, . . . , n} is to be found by asking for containment in a minimal number m(n, k) of subsets A1, . . . , Am with the restrictions |Ai| ≤ k < n2 for i = 1, 2, . . . ,m. Katona gave in 1966 the lower bound m(n, k) ≥ log n h( k n) in terms of binary entropy and the upper bound m(n, k) ≤ ⌈

This paper modifies the classic Weitzman search problem by granting the items (boxes) to be searched agency. In this zero-sum game, each box commits to a signal structure in order to maximize the chance that it is selected by the searcher at the completion of his search. There is a common, symmetric binary prior on the distribution of prizes within the boxes. If there are no search frictions, t...

nowadays, the internet has had a rapid expansion and presence in all areas of the individuals, institutions, companies and organizations lives. this has made large extent of data available so that the users need to access their desired information or services through using search engines. to continue and promote providing services, search engines require a source of income. sponsored search adv...