1. Convex analysis and nonlinear optimization : theory and examplesJonathan M. Borwein, Adrian S. Lewis, učbenik za višje in visoke šole Ključne besede: semmidefinite programming, convex analysis, symmetric matrices, duality, eigenvalue, embedding theorems, multipliers, polyhedra, polyhedral convex functions Objavljeno: 01.06.2012; Ogledov: 1124; Prenosov: 9 Povezava na celotno besedilo |
2. |
3. Searching for messages conforming to arbitrary sets of conditions in SHA-256Marko Hölbl, Christian Rechberger, Tatjana Welzer-Družovec, 2008, samostojni znanstveni sestavek ali poglavje v monografski publikaciji Opis: Recent progress in hash functions analysis has led to collisions on reduced versions of SHA-256. As in other hash functions, differential collision search methods of SHA-256 can be described by means of conditions on and between state and message bits. We describe a tool for efficient automatic searching of message pairs conforming to useful sets of conditions, i. e. stemming from (interleaved) local collisions. We not only considerably improve upon previous work [7], but also show the extendability of our approach to larger sets of conditions. Furthermore, we present the performance results of an actual implementation and pose an open problem in this context. Ključne besede: hash functions analysis, messages, SHA-256, automatic searching, differential collision search Objavljeno: 31.05.2012; Ogledov: 813; Prenosov: 32 Povezava na celotno besedilo |
4. Local search engine with global content based on domain specific knowledgeSandi Pohorec, Mateja Verlič, Milan Zorman, 2009, izvirni znanstveni članek Opis: In the growing need for information we have come to rely on search engines. The use of large scale search engines, such as Google, is as common as surfingthe World Wide Web. We are impressed with the capabilities of these search engines but still there is a need for improvment. A common problem withsearching is the ambiguity of words. Their meaning often depends on the context in which they are used or varies across specific domains. To resolve this we propose a domain specific search engine that is globally oriented. We intend to provide content classification according to the target domain concepts, access to privileged information, personalization and custom rankingfunctions. Domain specific concepts have been formalized in the form ofontology. The paper describes our approach to a centralized search service for domain specific content. The approach uses automated indexing for various content sources that can be found in the form of a relational database, we! b service, web portal or page, various document formats and other structured or unstructured data. The gathered data is tagged with various approaches and classified against the domain classification. The indexed data is accessible through a highly optimized and personalized search service. Ključne besede: information search, personalization, indexes, crawling, domain specific crawling, natural language processing, content tagging, distributed data sources, ranking functions Objavljeno: 31.05.2012; Ogledov: 1004; Prenosov: 21 Povezava na celotno besedilo |
5. |
6. Calculation of thermophysical and thermochemical properties during hydrocarbon combustionJurij Avsec, Franc Zgaga, Milan Marčič, 2002, izvirni znanstveni članek Opis: A mathematical model is presented for computing the chemical and thermophysical properties in the process of combustion of natural gas. To identify the parameters of state of combustion products, their composition hasto be known, which may be determined from chemical equilibrium. The computation is performed with the use of chemical potentials and statistical thermodynamics, featuring all important molecular contributions (translation, rotation, vibration, and intermolecular potential energy). A thermal equation of state with two virial terms is used. The real gas mixture is treated as consisting of four components: carbon dioxide, nitrogen, carbon monoxide, and water. Virial coefficients are dependent on temperature and mole fractions of the real components. Mixed terms are taken into account. The caloric equation of state is based on statistical thermodynamics for an ideal gas. Corrections are made in accordance with the second law of thermodynamics and the thermal equation of state. As the whole computation is based on matrix algebra, increasing the number of components presents no problems. We tested our model in the high-pressure region (100 bar) and the low-pressure region (1 bar), in the temperature range 500 - 6000°K. Our model is compared with other analytical models presented in the literature and shows relatively good agreement. At the same time we tested the influence of real conditions on the chemical and thermophysical properties of combustion products. Ključne besede: statistical thermodynamics, thermodynamical properties, combustion of natural gas, mathematical models, thermodynamic functions of state, equation of state, virial coefficients Objavljeno: 01.06.2012; Ogledov: 1109; Prenosov: 27 Povezava na celotno besedilo |
7. |
8. |
9. |
10. Paths through inverse limitsIztok Banič, Matevž Črepnjak, Matej Merhar, Uroš Milutinović, 2011, izvirni znanstveni članek Opis: In Banič, Črepnjak, Merhar and Milutinović (2010) [2] the authors proved that if a sequence of graphs of surjective upper semi-continuous set-valued functions ▫$f_n : X to 2^X$▫ converges to the graph of a continuous single-valued function ▫$f : X to X$▫, then the sequence of corresponding inverse limits obtained from ▫$f_n$▫ converges to the inverse limit obtained from ▫$f$▫. In this paper a more general result is presented in which surjectivity of ▫$f_n$▫ is not required. The result is also generalized to the case of inverse sequences with non-constant sequences of bonding maps. Finally, these new theorems are applied to inverse limits with tent maps. Among other applications, it is shown that the inverse limits appearing in the Ingram conjecture (with a point added) form an arc. Ključne besede: mathematics, topology, continua, limits, inverse limits, upper semi-continuous set-valued functions, paths, arcs Objavljeno: 07.06.2012; Ogledov: 800; Prenosov: 31 Povezava na celotno besedilo |