Sharif Digital Repository

Question Answering systems are one of the hot topics in context of information retrieval. In this paper, we develop an open-domain Question Answering system for spatial queries. We use Google for gathering raw data from the Web and then in a few iterations density of potential answers will be increased, finally based on a couple of evaluators the best answers are selected to be returned to user. Our proposed algorithm uses fuzzy methods to be more precise. Some experiments have been designed in order to evaluate the performance of our algorithm and results are totally promising. We will describe that how this algorithm can be applied to other type of questions as well  

This paper presents a new inference algorithm for active learning method (ALM). ALM is a pattern-based algorithm for soft computing, which uses the ink drop spread (IDS) algorithm as its main engine for feature extraction. In this paper, a fuzzy number is extracted from each IDS plane rather than from the narrow path and the spread, as in previous approaches. This leads to a significant reduction in the hardware required to implement the inference part of the algorithm and real-time computation of the implemented hardware. A modified version of the memristor crossbar structure is used to solve the problem of varying shapes of the ink drops, as reported in previous studies. In order to... 

Semantic web search engines are evolving and many prototype systems and some implementation have been developed. However, there are some different views on what a semantic search engine should do. In this paper, a categorization scheme for semantic web search engines are introduced and elaborated. For each category, its components are described according to a proposed general architecture and various approaches employed in these components are discussed. We also propose some factors to evaluate systems in each category. © 2006 IEEE  

IT Governance provides a business focus to enable alignment between business and IT objectives at high level COBIT framework and focused on IT operational levels, ITIL standard. COBIT and ITIL are not mutually exclusive and can be combined to provide a powerful IT governance, control and best-practice framework in IT service management. So ITIL business-IT strategic alignment perspective could be improved using COBIT framework. Focusing on COBIT processes which support (primarily and secondarily) strategic alignment, in this paper, first, we map COBIT 4.1 to ITIL v3 to identify how ITIL cover COBIT control objectives. Furthermore, based on control objectives which are not completely... 

One of the important elements of the new generation of the Web is the emergence of blogs. Currently a considerable number of users are creating content using blogs. Although Persian blogs have a short history, they have improved significantly during this short period. Because of fundamental differences between Persian and other languages, limited work has been done to analyze Persian blogs. In this work, a system named BlogDisc for automatic discovery and accumulation of Persian blogs is developed. This system uses content as well as link structure of the blogs. As an important part of this research, we propose an algorithm to recognize blogs that are not hosted on special blog hosts. © 2007... 

Several metrics have been proposed for recognition of relationships between elements of two Ontologies. Many of these methods select a number of such metrics and combine them to extract existing mappings. In this article, we present a method for selection of more effective metrics - based on data mining techniques. Furthermore, by having a set of metrics, we suggest a data-mining-like means for combining them into a better ontology alignment  

In the present study, methods for improving the hydraulic performance of labyrinth side weirs in a rectangular channel are reported based on model experimentation. For this purpose different arrangements and configurations of groups of guide vane plates and piles in the side weir flow field were tested. Experiments were conducted on labyrinth side weirs of different lengths and sill heights fitted in the test section of a rectangular glass-walled channel. Depths of flow were measured in both longitudinal and crosswise directions at regular intervals and their profiles were studied. It was found that the discharge coefficient of the labyrinth side weirs under these conditions gave... 

The literature suggests that organizations cannot be competitive if their business and information technology strategies are not aligned. Yet achieving strategic alignment continues to be a major concern for business executives. A number of alignment models have been offered in the literature, primary among them the Strategic Alignment model (SAM) and IT Governance (via ITIL). As there is no published research that attempts to present how effective ITIL V3 is to align business and IT in strategic level, this paper reports on determining aligning roles of ITIL by applying it to the SAM framework. In this regard, the (TIL Strategic Alignment model is proposed to describe ITIL V3 approach of... 

Ensuring that organizational IT is in alignment with and provides support for an organization's business strategy is critical to business success. As there is no published research that attempts to describe maturity of ITIL V3 in aligning business and IT at strategic level, this paper reports on determining aligning roles of ITIL V3 in practice. In this paper, ITIL maturity to business-IT strategic alignment is validated by Strategic Alignment Maturity model. Focusing on how ITIL V3 covers business-IT alignment maturity criteria of the model, the maturity of ITIL strategic alignment practices is assessed which makes it possible to recognize conceptual and practical competencies of ITIL to... 

The literature suggests that organizations cannot be competitive if their business and information technology strategies are not aligned. Yet achieving strategic alignment continues to be a major concern for business executives. A number of alignment models have been offered in the literature, primary among them the Strategic Alignment model (SAM) and IT Governance (via ITIL). As there is no published research that attempts to present how effective ITIL V3 is to align business and IT in strategic level, this paper reports on determining aligning roles of ITIL by applying it to the SAM framework. In this regard, the ITIL Strategic Alignment model is proposed to describe ITIL V3 approach of... 

Within the "pseudo-Dirac" scenario for massive neutrinos the existence of sterile neutrinos which are almost degenerate in mass with the active ones is hypothesized. The presence of these sterile neutrinos can affect the flavor composition of cosmic neutrinos arriving at Earth after traveling large distances from astrophysical objects. We examine the prospects of neutrino telescopes such as IceCube to probe the very tiny mass squared differences 10-12eV2>Δm2>10-19eV2, by analyzing the ratio of μ-track events to showerlike events. Considering various sources of uncertainties which enter this analysis, we examine the capability of neutrino telescopes to verify the validity of the pseudo-Dirac... 

We discuss the prospect of extracting the values of the mixing parameters δ and θ13 through the detection of cosmic neutrinos in the planned and forthcoming neutrino telescopes. We take the ratio of the μ-track to shower-like events, R, as the realistic quantity that can be measured in the neutrino telescopes. We take into account several sources of uncertainties that enter the analysis. We then examine to what extent the deviation of the initial flavor composition from we : w μ : wτ 1 : 2 : 0 can be tested  

Currently there is no standard test collection for evaluation of Farsi information retrieval systems. In this paper we introduce Mahak, the first complete test collection generally available for evaluating Farsi information retrieval systems. In addition, we have used different methods for constructing Mahak qrels and we have compared performance of these methods  

Fractures identification is essential during exploration, drilling and well completion of naturally fractured reservoirs since they have a significant impact on flow contribution. There are different methods to characterize these systems based on formation properties and fluid flow behaviour such as logging and testing. Pressure-transient testing has long been recognized as a reservoir characterization tool. Although welltest analysis is a recommended technique for fracture evaluation, but its use is still not well understood. Analysis of pressure transient data provides dynamic reservoir properties such as average permeability, fracture storativity and fracture conductivity.An infusion of... 

Modern search engines use link structure of the World Wide Web in order to gain better results for ranking the results of users' queries. One of the most popular ranking algorithms which is based on link analysis is HITS. It generates very accurate outputs but because of huge amount of online computations, this algorithm is relatively slow. In this paper we introduce PHITS, a parallelized version of the HITS algorithm that is suitable for working with huge web graphs in a reasonable time. For implementing this algorithm, we use WebGraph framework and we focus on parallelizing access to web graph as the main bottleneck in the HITS algorithm. © 2006 IEEE  

The annihilation of dark matter particles captured by the Sun can lead to a neutrino flux observable in neutrino detectors. Considering the fact that these dark matter particles are nonrelativistic, if a pair of dark matter annihilates to a neutrino pair, the spectrum of neutrinos will be monochromatic. We show that in this case, even after averaging over the production point inside the Sun, the oscillatory terms of the oscillation probability do not average to zero. This leads to interesting observable features in the annual variation of the number of muon track events. We show that smearing of the spectrum due to thermal distribution of dark matter inside the Sun is too small to wash out... 

We construct a new set of combinations from the mass matrices of the charged leptons and neutrinos that are invariant under basis transformation, hereafter the invariants. We use these invariants to study various symmetries and neutrino mass textures in a basis independent way. In particular, we show that by using these invariants the ansatz such as μ - τ exchange and reflection symmetries, various texture zeros and flavor symmetries can be expressed in a general basis. © 2008 Elsevier B.V. All rights reserved  

We examine the feasibility of deriving neutrino mixing parameters δ and θ13 from the cosmic neutrino flavor composition under the assumption that the flavor ratios of the cosmic neutrinos at the source were Fνe + Fover(ν, ̄)e : Fνμ + Fover(ν, ̄)μ : Fντ + Fover(ν, ̄)τ = 1 : 2 : 0. We analyze various uncertainties that enter the derivation of δ and θ13 from the ratio of the shower-like to μ-tracks events which is the only realistic source of information on the flavor composition at neutrino telescopes such as ICECUBE. We then examine to what extent the deviation of the initial flavor ratio from 1 : 2 : 0 can be tested by measurement of this ratio at neutrino telescopes taking into account...