Browsing by Subject "Information analysis"

Now showing 1 - 20 of 23

Open Access
Algorithms for layout of disconnected graphs
(Elsevier, 2000) Doğrusöz, Uğur
We present efficient algorithms for the layout of disconnected objects in a graph (isolated nodes and components) for a specified aspect ratio. These linear and near-linear algorithms are based on alternate-bisection and two-dimensional packing methodologies. In addition, the parameters that affect the performance of these algorithms as well as the circumstances under which the two methodologies perform well are analyzed.
Open Access
An automatic approach to construct domain-specific web portals
(ACM, 2007-11) Altıngövde, İsmail Şengör; Özcan, Rıfat; Çetintaş, Süleyman; Yılmaz, Hakan; Ulusoy, Özgür
We describe the architecture of an automatic domain-specific Web portal construction system. The system has three major components: i) a focused crawler that collects the domain-specific pages on the Web, ii) an information extraction engine that extracts useful fields from these Web pages, and iii) a query engine that allows both typical keyword based queries on the pages and advanced queries on the extracted data fields. We present a prototype system that works for the course homepages domain on the Web. A user study with the prototype system shows that our approach produces high quality results and achieves better precision figures than the typical keyword based search. Copyright 2007 ACM.
Open Access
BilKristal 4.0: A tool for crystal parameters extraction and defect quantification
(Elsevier, 2015) Okuyan, E.; Okuyan, C.
In this paper, we present a revised version of BilKristal 3.0 tool. Raycast screenshot functionality is added to provide improved visual analysis. We added atomic distance analysis functionality to assess crystalline defects. We improved visualization capabilities by adding high level cut function definitions. Discovered bugs are fixed and small performance optimizations are made. © 2015 Elsevier B.V. All rights reserved.
Open Access
Chat mining for gender prediction
(Springer, 2006-10) Küçükyılmaz, Tayfun; Cambazoğlu, B. Barla; Aykanat, Cevdet; Can, Fazlı
The aim of this paper is to investigate the feasibility of predicting the gender of a text document's author using linguistic evidence. For this purpose, term- and style-based classification techniques are evaluated over a large collection of chat messages. Prediction accuracies up to 84.2% are achieved, illustrating the applicability of these techniques to gender prediction. Moreover, the reverse problem is exploited, and the effect of gender on the writing style is discussed. © Springer-Verlag Berlin Heidelberg 2006.
Open Access
Dynamic texture detection, segmentation and analysis
(ACM, 2007-07) Töreyin, Behçet Uğur; Dedeoğlu, Yiğithan; Çetin, A. Enis; Fazekas, S.; Chetverikov, D.; Amiaz, T.; Kiryati, N.
Dynamic textures are common in natural scenes. Examples of dynamic textures in video include fire, smoke, clouds, trees in the wind, sky, sea and ocean waves etc. In this showcase, (i) we develop real-time dynamic texture detection methods in video and (ii) present solutions to video object classification based on motion information. Copyright 2007 ACM.
Open Access
The effects of structural characteristics of explanations on use of a DSS
(Elsevier, 2006) Gönül, M. S.; Önkal D.; Lawrence, M.
Research in the field of expert systems has shown that providing supporting explanations may influence effective use of system developed advice. However, despite many studies showing the less than optimal use made of DSS prepared advice, almost no research has been undertaken to study if the provision of explanations enhances the users' ability to wisely accept DSS advice. This study outlines an experiment to examine the effects of structural characteristics of explanations provided within a forecasting DSS context. In particular, the effects of explanation length (short vs. long) and the conveyed confidence level (weak vs. strong confidence) are examined. Strongly confident and long explanations are found to be more effective in participants' acceptance of interval forecasts. In addition, explanations with higher information value are more effective than those with low information value and thus are persuasive tools in the presentation of advice to users.
Open Access
A framework for applying the principles of depth perception to information visualization
(Association for Computing Machinery, 2013) Zeynep, C. Y.; Bulbul, A.; Capin, T.
During the visualization of 3D content, using the depth cues selectively to support the design goals and enabling a user to perceive the spatial relationships between the objects are important concerns. In this novel solution, we automate this process by proposing a framework that determines important depth cues for the input scene and the rendering methods to provide these cues. While determining the importance of the cues, we consider the user's tasks and the scene's spatial layout. The importance of each depth cue is calculated using a fuzzy logic-based decision system. Then, suitable rendering methods that provide the important cues are selected by performing a cost-profit analysis on the rendering costs of the methods and their contribution to depth perception. Possible cue conflicts are considered and handled in the system. We also provide formal experimental studies designed for several visualization tasks. A statistical analysis of the experiments verifies the success of our framework. © 2013 ACM.
Open Access
How content management problem of a remote laboratory system can be handled by integrating an open source learning management system? Problems and solutions
(IEEE, 2007) Özdoğru, Burcu; Cagıltay, N. E.
This paper represents the design and implementation of the integration process of an open source learning management system (LMS) to the remote laboratory platform. The reason of using a learning management system is to prevent the problems which can be seen in the learner side of the remote laboratory systems. However, since using a learning management system such as Moodle can handle the learner problems, since it is a separate system, there are still other problems to be handled such as integrating it with the other parts of remote laboratory systems. This study explores the background information of LMS, the problems faced while integrating Moodle to remote laboratory applications, the chosen content management systems' architecture, our architecture for integrating Moodle with the remote laboratory system and the solutions we propose for the problems.
Open Access
Information arts and information science: time to unite?
(Wiley, 2006) Karamuftuoglu, M.
This article explicates the common ground between two currently independent fields of Inquiry, namely information arts and information science, and suggests a frame-work that could unite them as a single field of study. The article defines and clarifies the meaning of information art and presents an axiological framework that could be used to judge the value of works of information art. The axiological framework is applied to examples of works of information art to demonstrate its use. The article argues that both Information arts and Information science could be studied under a common framework; namely, the domain-analytic or sociocognitive approach. It also is argued that the unification of the two fields could help enhance the meaning and scope of both information science and information arts and therefore be beneficial to both fields.
Open Access
An information-theoretic analysis of Grover's algorithm
(IEEE, 2003-06-07) Arıkan, Erdal
Grover discovered a quantum algorithm for identifying a target element in an unstructured search universe of N items in approximately 1r/4VN queries to a quantum oracle. For classical search using a classical oracle, the search complexity is of order N /2 queries since on average half of the items must be searched. In work preceding Grover's, Bennett et al. had shown that no quantum algorithm can solve the search problem in fewer than D(VN) queries. Thus, Grover's algorithm has optimal order of complexity. Here, we present an informationtheoretic analysis of Grover's algorithm and show that the square-root speed-up by Grover's algorithm is the best possible by any algorithm using the same quantum oracle.
Open Access
L1 norm based multiplication-free cosine similarity measures for big data analysis
(IEEE, 2014-11) Akbaş, Cem Emre; Bozkurt, Alican; Arslan, Musa Tunç; Aslanoğlu, Hüseyin; Çetin, A. Enis
The cosine similarity measure is widely used in big data analysis to compare vectors. In this article a new set of vector similarity measures are proposed. New vector similarity measures are based on a multiplication-free operator which requires only additions and sign operations. A vector 'product' using the multiplication-free operator is also defined. The new vector product induces the ℓ1-norm. As a result, new cosine measure-like similarity measures are normalized by the ℓ1-norms of the vectors. They can be computed using the MapReduce framework. Simulation examples are presented. © 2014 IEEE.
Open Access
A layout algorithm for undirected compound graphs
(Elsevier, 2009-03-15) Doğrusöz, Uğur; Giral, Erhan; Çetintaş, Ahmet; Civril, Ali; Demir, Emek
We present an algorithm for the layout of undirected compound graphs, relaxing restrictions of previously known algorithms in regards to topology and geometry. The algorithm is based on the traditional force-directed layout scheme with extensions to handle multi-level nesting, edges between nodes of arbitrary nesting levels, varying node sizes, and other possible application-specific constraints. Experimental results show that the execution time and quality of the produced drawings with respect to commonly accepted layout criteria are quite satisfactory. The algorithm has also been successfully implemented as part of a pathway integration and analysis toolkit named PATIKA, for drawing complicated biological pathways with compartmental constraints and arbitrary nesting relations to represent molecular complexes and various types of pathway abstractions. © 2008 Elsevier Inc. All rights reserved.
Open Access
Metadata extraction from text in soccer domain
(IEEE, 2008-10) Göktürk, Z. O.; Çiçekli, N. K.; Çiçekli, İlyas
Event detection is a crucial part for soccer video searching and querying. The event detection could be done by video content itself or from a structured or semi structured text files gathered from sports web sites. In this paper, we present an approach of metadata extraction from match reports for soccer domain. The UEFA Cup and UEFA Champions League Match Reports are downloaded from the web site of UEFA by a web-crawler. Using regular expressions we annotate these match reports and then extract events from annotated match reports. Extracted events are saved in an MPEG-7 file. We present an interface that is used to query the events in the MPEG-7 match corpus. If an associated match video is available, the video portions that correspond to the found events could be played. © 2008 IEEE.
Open Access
A parametric analysis of finite phased arrays of printed dipoles on large circular cylinders and comparisons with the planar case
(IEEE, 2004-06) Güner, B.; Ertürk Vakur B.; Bakır, O.
A parametric study of finite phased arrays of printed dipoles on electrically large coated cylinders is performed using a spatial domain hybrid MoM/Green's function technique. Dipole currents and several performance metrics like active reflection coefficient and input impedances of the dipoles are calculated and compared with their planar counterparts. The effects of the curvature, dipole orientation and changes in the array and host body parameters are observed and discussed.
Open Access
Performance of query processing implementations in ranking-based text retrieval systems using inverted indices
(Elsevier Ltd, 2006-07) Cambazoglu, B. B.; Aykanat, Cevdet
Similarity calculations and document ranking form the computationally expensive parts of query processing in ranking-based text retrieval. In this work, for these calculations, 11 alternative implementation techniques are presented under four different categories, and their asymptotic time and space complexities are investigated. To our knowledge, six of these techniques are not discussed in any other publication before. Furthermore, analytical experiments are carried out on a 30 GB document collection to evaluate the practical performance of different implementations in terms of query processing time and space consumption. Advantages and disadvantages of each technique are illustrated under different querying scenarios, and several experiments that investigate the scalability of the implementations are presented. © 2005 Elsevier Ltd. All rights reserved.
Open Access
Person search made easy
(Springer, Berlin, Heidelberg, 2005) İkizler, Nazlı; Duygulu, Pınar
In this study, we present a method to extensively reduce the number of retrieved images and increase the retrieval performance for the person queries on the broadcast news videos. A multi-modal approach which integrates face and text information is proposed. A state-of-the-art face detection algorithm is improved using a skin color based method to eliminate the false alarms. This pruned set is clustered to group the similar faces and representative faces are selected from each cluster to be provided to the user. For six person queries of TRECVID2004, on the average, the retrieval rate is increased from 8% to around 50%, and the number of images that the user has to inspect are reduced from hundreds and thousands to tens. © Springer-Verlag Berlin Heidelberg 2005.
Open Access
Query Processing in Context - Oriented Retrieval of Information
(1998) Saygin, A.P.; Yavuz, T.
This paper proposes a context-oriented approach towards document retrieval and presents the query processing component of the retrieval process in detail. Our approach differs from the existing ones by its use of word sense disambiguation in the first stages and by its employment of query structuring. The proposed system, called CORE, attempts to match contexts of documents and queries rather than regarding these as sets of words. Clarifying the indicated meaning of the words in the query before the search is conducted will eliminate a large number of irrelevant documents and will enable the construction of a context for the query. Query structuring allows the preparation of a query execution plan for an efficient search and thus yields response time improvement. In addition, it positively affects Recall and Precision by considering the relative importance of the words in the query.
Open Access
Realistic rendering and animation of a multi-layered human body model
(IEEE, 2006) Yeşil, Mehmet Şahin; Güdükbay, Uğur
A framework for realistic rendering of a multi-layered human body model is proposed in this paper. The human model is composed of three layers: skeleton, muscle, and skin. The skeleton layer, represented by a set of joints and bones, controls the animation of the human body using inverse kinematics. Muscles are represented with action lines that are defined by a set of control points. An action line applies the force produced by a muscle on the bones and on the skin mesh. The skin layer is modeled as a 3D mesh and deformed during animation by binding the skin layer to both the skeleton and muscle layers. The skin is deformed by a two-step algorithm according to the current state of the skeleton and muscle layers. Performance experiments show that it is possible to obtain real-time frame rates for a moderately complex human model containing approximately 33,000 triangles on the skin layer. © 2006 IEEE.
Open Access
Target differentiation and localization using infrared sensors
(SPIE, 2003-08) Aytaç, Tayfun; Barshan, Billur
We discuss the use of low-cost infrared sensors in differentiating and localizing commonly encountered target primitives in indoor environments, such as planes, corners, edges, and cylinders. Single intensity readings are highly dependent on target location and properties and this dependence cannot be represented simply. We propose a method that can achieve position-invariant target differentiation without relying on absolute intensity readings and verify it experimentally. The correct identification rates for planes, 90° corners and edges, and cylinders are 90%, 100%, 82.5%, and 92.5%, respectively. The distance of the target can be estimated with an average error of 0.59 cm and the azimuth angle can be estimated with an error of 1.58°.
Open Access
Topic tracking using chronological term ranking
(2013-10) Acun, Bilge; Başpınar, Alper; Oǧuz, Ekin; Saraç, M.İlker; Can, Fazlı
Topic tracking (TT) is an important component of topic detection and tracking (TDT) applications. TT algorithms aim to determine all subsequent stories of a certain topic based on a small number of initial sample stories. We propose an alternative similarity measure based on chronological term ranking (CTR) concept to quantify the relatedness among news articles for topic tracking. The CTR approach is based on the fact that in general important issues are presented at the beginning of news articles. By following this observation we modify the traditional Okapi BM25 similarity measure using the CTR concept. Using a large standard test collection we show that our method provides a statistically significantly improvement with respect to the Okapi BM25 measure. The highly successful performance indicates that the approach can be used in real applications. © 2013 Springer-Verlag London.