Article
О возможном развитии метода извлечения данных для восстановления файлов формата JPEG
A possible application of the author’s method of differentiation of clusters belonging to JPEG files from other clusters on the digital media for expanding of existing data recovery methods is described in the work. The decrease in the number of operations needed to reach the correct result is estimated. A way of using described method for automated improvement of data carving results is considered.
The results of the experimental attempts of elaboration of the previously proposed method for identifying clusters belonging to JPEG files are described. Type II errors rates for different file formats are estimated. The possible ways of their improvement for some file formats are offered.
File fragmentation proves to be a major challenge for the majority of file carving techniques. Following the works of Simson Garfinkel, Nasir Memon and other authors we seek to find a technique to identify digital fragments (clusters or sectors) of JPEG-files on the digital storage medium or at least sort all the fragments of the storage based on their probability of being the part of JPEG-file from the most probable to the least probable. This paper offers the technique of identifying clusters of JPEG-files on the storage medium based on binary patterns and the experimental results of an attempt to build a similar technique for sector identifying.
> Georgia. Georgia's $16 bln economy saw strong annual growth in 2010-12 of around 6-7%, but in 2013 growth slowed to 3.2%, which is still good but not enough for an economy with a GDP per capita of around $3,600. Indeed, over the year, Georgia - which depends heavily on capital inflows - failed to utilize its competitive advantage of lower unit labor costs than in other countries in the region, such as Turkey and Bulgaria. > Turkey. The Turkish economy performed well in 1H14 as industrial output rose 3.8% y-o-y (down from 5.3% y-o-y in 5m14). GDP climbed 4.3% y-o-y in 1Q14, and we estimate 2Q14 to show GDP growth just below 4.0%. We expect 3.7% for 2014 as a whole, which is a bit stronger than we expected early in the year. > Bulgaria. Similar to some other smaller economies in the region, Bulgaria benefited from a recovery in the Eurozone that was characterized by ECB President Mario Draghi on August 7 as "moderate and uneven." Bulgarian GDP picked up to around 1.4% y-o-y in 1H14 (1.2% in 1Q14 and 1.6% in 2Q14). Given that Bulgaria's currency is pegged to the euro, the country was unable to extract benefits from this recovery to the same extent as some other countries, such as Turkey, Hungary or Romania, whose monetary policy and exchange rates are more independent. In 2H14, Bulgaria will face additional pressure from potentially slower growth in the EU as policy makers in the West and Russia continue experiments with sanctions.
A model for organizing cargo transportation between two node stations connected by a railway line which contains a certain number of intermediate stations is considered. The movement of cargo is in one direction. Such a situation may occur, for example, if one of the node stations is located in a region which produce raw material for manufacturing industry located in another region, and there is another node station. The organization of freight traffic is performed by means of a number of technologies. These technologies determine the rules for taking on cargo at the initial node station, the rules of interaction between neighboring stations, as well as the rule of distribution of cargo to the final node stations. The process of cargo transportation is followed by the set rule of control. For such a model, one must determine possible modes of cargo transportation and describe their properties. This model is described by a finite-dimensional system of differential equations with nonlocal linear restrictions. The class of the solution satisfying nonlocal linear restrictions is extremely narrow. It results in the need for the “correct” extension of solutions of a system of differential equations to a class of quasi-solutions having the distinctive feature of gaps in a countable number of points. It was possible numerically using the Runge–Kutta method of the fourth order to build these quasi-solutions and determine their rate of growth. Let us note that in the technical plan the main complexity consisted in obtaining quasi-solutions satisfying the nonlocal linear restrictions. Furthermore, we investigated the dependence of quasi-solutions and, in particular, sizes of gaps (jumps) of solutions on a number of parameters of the model characterizing a rule of control, technologies for transportation of cargo and intensity of giving of cargo on a node station.
Event logs collected by modern information and technical systems usually contain enough data for automated process models discovery. A variety of algorithms was developed for process models discovery, conformance checking, log to model alignment, comparison of process models, etc., nevertheless a quick analysis of ad-hoc selected parts of a journal still have not get a full-fledged implementation. This paper describes an ROLAP-based method of multidimensional event logs storage for process mining. The result of the analysis of the journal is visualized as directed graph representing the union of all possible event sequences, ranked by their occurrence probability. Our implementation allows the analyst to discover process models for sublogs defined by ad-hoc selection of criteria and value of occurrence probability
The geographic information system (GIS) is based on the first and only Russian Imperial Census of 1897 and the First All-Union Census of the Soviet Union of 1926. The GIS features vector data (shapefiles) of allprovinces of the two states. For the 1897 census, there is information about linguistic, religious, and social estate groups. The part based on the 1926 census features nationality. Both shapefiles include information on gender, rural and urban population. The GIS allows for producing any necessary maps for individual studies of the period which require the administrative boundaries and demographic information.
It is well-known that the class of sets that can be computed by polynomial size circuits is equal to the class of sets that are polynomial time reducible to a sparse set. It is widely believed, but unfortunately up to now unproven, that there are sets in EXPNP, or even in EXP that are not computable by polynomial size circuits and hence are not reducible to a sparse set. In this paper we study this question in a more restricted setting: what is the computational complexity of sparse sets that are selfreducible? It follows from earlier work of Lozano and Torán (in: Mathematical systems theory, 1991) that EXPNP does not have sparse selfreducible hard sets. We define a natural version of selfreduction, tree-selfreducibility, and show that NEXP does not have sparse tree-selfreducible hard sets. We also construct an oracle relative to which all of EXP is reducible to a sparse tree-selfreducible set. These lower bounds are corollaries of more general results about the computational complexity of sparse sets that are selfreducible, and can be interpreted as super-polynomial circuit lower bounds for NEXP.