Graph matching Research Papers - Academia.edu (original) (raw)

2025, IEEE Transactions on Pattern Analysis and Machine Intelligence

We present a new approach for matching sets of branching curvilinear structures that form graphs embedded in R 2 or R 3 and may be subject to deformations. Unlike earlier methods, ours does not rely on local appearance similarity nor does require a good initial alignment. Furthermore, it can cope with non-linear deformations, topological differences, and partial graphs. To handle arbitrary non-linear deformations, we use Gaussian Processes to represent the geometrical mapping relating the two graphs. In the absence of appearance information, we iteratively establish correspondences between points, update the mapping accordingly, and use it to estimate where to find the most likely correspondences that will be used in the next step. To make the computation tractable for large graphs, the set of new potential matches considered at each iteration is not selected at random as in many RANSAC-based algorithms. Instead, we introduce a so-called Active Testing Search strategy that performs a priority search to favor the most likely matches and speed-up the process. We demonstrate the effectiveness of our approach first on synthetic cases and then on angiography data, retinal fundus images, and microscopy image stacks acquired at very different resolutions.

2025

Interoperability requires the resolution of syntactic and semantic variations among system data models. To address this problem, we developed the Intelligent Mapping Toolkit (IMT), which employs a distributed multi-agent architecture to enable the mixed-initiative mapping of metadata and instances. This architecture includes a novel federation of service-encapsulated matching agents that leverage casebased reasoning methods. We recently used the IMT matching service to develop several domain-specific search applications in addition to the IMT mapping application.

2025

The paper presents a methodology for the development of robot software controllers, based on actual software component approaches and robot control architectures. This methodology defines a process that guides developers from the analysis of a robot controller to its execution. A proposed generic software controller architecture, useful for analysis and integration, and a dedicated component-based language, focusing on modularity, reusability, scalability and upgradeability of controller architectures parts during design and implementation steps, are briefly presented.

2025

This paper presents an overview of the current image processing techniques used to solve various problems, especially in the field of image indexing/retrieval. We aim to provide a solid, comprehensive reference source for other researchers involved in the image processing field. We will be describe the search spaces, the most common techniques, their advantages and drawbacks and the alternatives proposed by various researchers in the community.

2025

English. In this work we present a methodology for the annotation of Attribution Relations (ARs) in speech which we apply to create a pilot corpus of spoken informal dialogues. This represents the first step towards the creation of a resource for the analysis of ARs in speech and the development of automatic extraction systems. Despite its relevance for speech recognition systems and spoken language understanding, the relation holding between quotations and opinions and their source has been studied and extracted only in written corpora, characterized by a formal register (news, literature, scientific articles). The shift to the informal register and to a spoken corpus widens our view of this relation and poses new challenges. Our hypothesis is that the decreased reliability of the linguistic cues found for written corpora in the fragmented structure of speech could be overcome by including prosodic clues in the system. The analysis of SARC confirms the hypothesis showing the crucial role played by the acoustic level in providing the missing lexical clues.

2025, National Conference on Artificial Intelligence

We present a system for textual inference (the task of inferring whether a sentence follows from another text) that uses learning and a logical-formula semantic representation of the text. More precisely, our system begins by parsing and then transforming sentences into a logical formula-like representation similar to the one used by . An abductive theorem prover then tries to find the minimum "cost" set of assumptions necessary to show that one statement follows from the other. These costs reflect how likely different assumptions are, and are learned automatically using information from syntactic/semantic features and from linguistic resources such as WordNet. If one sentence follows from the other given only highly plausible, low cost assumptions, then we conclude that it can be inferred. Our approach can be viewed as combining statistical machine learning and classical logical reasoning, in the hope of marrying the robustness and scalability of learning with the preciseness and elegance of logical theorem proving. We give experimental results from the recent PASCAL RTE 2005 challenge competition on recognizing textual inferences, where a system using this inference algorithm achieved the highest confidence weighted score.

2025, Document Analysis and Recognition

A spatial relation graph (SRG) and its partial matching method are proposed for online composite graphics representation and recognition. The SRGbased approach emphasizes three characteristics of online graphics recognition: partial, structural, and independent of stroke order and stroke number. A constrained partial permutation strategy is also proposed to reduce the computational cost of matching two SRGs, which is originally an NP-complete problem as is graph isomorphism. Experimental results show that our proposed SRG-based approach is both efficient and effective for online composite graphics recognition in our sketchbased graphics input system -SmartSketchpad.

2025, Lecture Notes in Computer Science

ID/IDREF is an important and widely used feature in XML documents for eliminating data redundancy. Most existing algorithms consider an XML document with ID references as a graph and perform graph matching for queries involving ID references. Graph matching naturally brings higher complexity compared with original tree matching algorithms that process XML queries. In this paper, we make use of semantics of ID/IDREF to reduce graph matching to tree matching to process queries involving ID references. Using our approach, an XML document with ID/IDREF is not treated as a graph, and a general query with ID references will be decomposed and processed using tree pattern matching techniques, which are more efficient than graph matching. Furthermore, our approach is able to handle complex ID references, such as cyclic references and sequential references, which cannot be handled efficiently by existing approaches. The experimental results show that our approach is 20-50% faster than MonetDB, an XQuery engine, and at least 100 times faster than TwigStackD, an existing graph matching algorithm.

2025, Journal of Robotic Systems

This article addresses the problem of determining the 3‐dimensional locations of salient points in the environment of a moving camera based on a monocular image sequence obtained by the camera. The camera's translational and rotational velocities are assumed to be known approximately via inertial sensors. The motion of the camera is represented by a constant velocity model. Salient points in the image sequence are extracted using Gabor wavelets and tracked using labeled graph matching. The 3‐D positions of the selected environmental points relative to the camera are then estimated recursively using an extended Kalman filter (EKF), after initialization by two‐frame motion stereo. The motion parameters of the camera are also refined simultaneously. Experimental results on real data are given. © 1992 John Wiley & Sons, Inc.

2025, IEEE access

The increasing age of our society is connected to a rising number of people suffering from disorders. One such disorder is Parkinson's disease (PD). Predictions indicate that the number of individuals affected by PD will more, than double in the future. Neurologists and data scientists consider handwriting as one of the motor symptoms of PD and recognize it as a valuable resource for detecting this disorder. Within this framework, we introduce an innovative system for Parkinson's disease detection, which encompasses several key stages. The process commences with data augmentation and preprocessing, subsequently leading to the segmentation of online handwriting into Beta strokes. Following that, feature extraction is carried out utilizing the Beta-elliptical approach and the fuzzy perceptual detector. Finally, we employ bidirectional long short-term memory (BLSTM) for the classification task. To assess the performance of our system, we created a new online Arabic handwriting dataset designed for detecting Parkinson's disease. The results we obtained affirm the efficacy of our proposed system. Through comprehensive evaluations conducted on the PaHaW dataset, we achieved good accuracy, thereby highlighting that our system surpasses the performance of existing systems.

2025

The objective of this work is to develop a general structure for semantic image analysis that is suitable for content-based image retrieval in medical applications and an architecture for its efficient implementation. Stepwise content analysis of medical images results in six layers of information modeling (raw data layer, registered data layer, feature layer, scheme layer, object layer, knowledge layer). Medical expert knowledge is incorporated into several layers. In the registered data layer, a reference database with 10,000 images categorized according to the image modality, orientation, body region examined, and biological system imaged is used. By means of prototypes in each category, identification of objects and their geometrical or temporal relationships are handled in the object and the knowledge layer, respectively. Depending on the complexity of the query, it is processed on the higher layers starting with the scheme layer, where a hierarchical blob representation of image content is provided. Here, local image similarity is assessed by graph matching. The multilayer processing is implemented using a distributed system designed with only three core elements: (i) the central database holds program sources, processing scheme descriptions, images, features, blob trees, and administrative information about the workstation cluster; (ii) the scheduler balances distributed computing by addressing daemons running on all connected workstations; and (iii) the web server provides graphical user interfaces for data entry and retrieval, which can be easily adapted to a variety of applications for content-based image retrieval in medicine. Since manual labeling of reference data is still in progress, the system was used so far for processing primitive queries, i.e. queries regarding the category. However, since all feature transformations in all semantic layers are based the same implemented mechanism, this is sufficient to validate the overall system concept. The leaving-oneout experiments were distributed by the scheduler and controlled via corresponding job lists. The experiments have shown that the IRMA framework offers transparency regarding the viewpoint of a distributed system and the user, such as (i) location and access transparency for data and program sources; (ii) replication transparency for programs in development; (iii) concurrency transparency for job processing and feature extraction; (iv) system transparency at method implementation time; and (v) job distribution transparency when issuing a query. The proposed architecture is suitable for content-based image retrieval in medical applications. It improves current picture archiving and communication systems that still rely on alphanumerical descriptions, which are insufficient for image retrieval of high recall and precision.

2025, HAL (Le Centre pour la Communication Scientifique Directe)

Extract the features for a multi-touch gesture is difficult due to the complex temporal and motion relations between multiple trajectories. In this paper we present a new generic graph model to quantify the shape, temporal and motion information from multi-touch gesture. To make a comparison between graph, we also propose a specific graph matching method based on graph edit distance. Results prove that our graph model can be fruitfully used for multi-touch gesture pattern recognition purpose with the classifier of graph embedding and SVM.

2025

A maximum stable set in a graph G is a stable set of maximum size. S is a local maximum stable set of G, and we write S ∈ Ψ(G), if S is a maximum stable set of the subgraph spanned by S ∪ N (S), where N (S) is the neighborhood of S. A matching M is uniquely restricted if its saturated vertices induce a subgraph which has a unique perfect matching, namely M itself. Nemhauser and Trotter Jr. , proved that any S ∈ Ψ(G) is a subset of a maximum stable set of G. In we have shown that the family Ψ(T ) of a forest T forms a greedoid on its vertex set. In this paper we demonstrate that for a bipartite graph G, Ψ(G) is a greedoid on its vertex set if and only if all its maximum matchings are uniquely restricted.

2025, Discrete Applied Mathematics

A matching M is uniquely restricted in a graph G if its saturated vertices induce a subgraph which has a unique perfect matching, namely M itself [M.C. Golumbic, T. Hirst, M. Lewenstein, Uniquely restricted matchings, Algorithmica 31 (2001) 139-154]. G is a König-Egerváry graph provided (G) + (G) = |V (G)| [R.W. Deming, Independence numbers of graphs-an extension of the König-Egerváry theorem, Discrete Math. 27 (1979) 23-33; F. Sterboul, A characterization of the graphs in which the transversal number equals the matching number, J. Combin. Theory Ser. B 27 (1979) 228-229], where (G) is the size of a maximum matching and (G) is the cardinality of a maximum stable set. S is a local maximum stable set of G, and we write S ∈ (G), if S is a maximum stable set of the subgraph spanned by S ∪ N(S), where N(S) is the neighborhood of S. Nemhauser and Trotter [Vertex packings: structural properties and algorithms, Math. Programming 8 (1975) 232-248], proved that any S ∈ (G) is a subset of a maximum stable set of G. In [V.E. Levit, E. Mandrescu, Local maximum stable sets in bipartite graphs with uniquely restricted maximum matchings, Discrete Appl. Math. 132 (2003) 163-174] we have proved that for a bipartite graph G, (G) is a greedoid on its vertex set if and only if all its maximum matchings are uniquely restricted. In this paper we demonstrate that if G is a triangle-free graph, then (G) is a greedoid if and only if all its maximum matchings are uniquely restricted and for any S ∈ (G), the subgraph spanned by S ∪ N(S) is a König-Egerváry graph.

2025, Concepts, Methodologies, Tools, and Applications

To annotate the biological function of a protein molecule, it is essential to have information on its 3D structure. Many successful methods for function prediction are based on determining structurally conserved regions because the functional residues are proved to be more conservative than others in protein evolution. Since the 3D conformation of a protein can be represented by a contact map graph, graph matching, algorithms are often employed to identify the conserved residues in weakly homologous protein pairs. However, the general graph matching algorithm is computationally expensive because graph similarity searching is essentially a NP-hard problem. Parallel implementations of the graph matching are often exploited to speed up the process. In this chapter,the authors review theoretical and computational approaches of graph theory and the recently developed graph matching algorithms for protein function prediction.

2025, International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems

Given that exact pair-wise graph matching has a high computational cost, different representational schemes and matching methods have been devised in order to make matching more efficient. Such methods include representing the graphs as tree structures, transforming the structures into strings and then calculating the edit distance between those strings. However many coding schemes are complex and are computationally expensive. In this paper, we present a novel coding scheme for unlabeled graphs and perform some empirical experiments to evaluate its precision and cost for the matching of neighborhood subgraphs in online social networks. We call our method OSG-L (Ordered String Graph-Levenshtein). Some key advantages of the pre-processing phase are its simplicity, compactness and lower execution time. Furthermore, our method is able to match both non-isomorphisms (near matches) and isomorphisms (exact matches), also taking into account the degrees of the neighbors, which is adequate ...

2025, Sensors (Basel, Switzerland)

In the field of ambient assisted living, the best results are achieved with systems that are less intrusive and more intelligent, that can easily integrate both formal and informal caregivers and that can easily adapt to the changes in the situation of the elderly or disabled person. This paper presents a graph-based representation for context information and a simple and intuitive method for situation recognition. Both the input and the results are easy to visualize, understand and use. Experiments have been performed on several AAL-specific scenarios.

2025, Physica D: Nonlinear Phenomena

In this paper, we consider comparing dynamical systems by using graph matching method either between the graphs representing the underlying symbolic dynamics, or graphs approximating the action of the systems on a fine but otherwise non generating partition. For conjugate systems, the graphs are isomorphic and we show that the permutation matrices that relate the adjacency matrices coincides with the solution of Monge's mass transport problem. We use the underlying Earth Mover's Distance (EMD) to generate the "approximate" matching matrix to illustrate the association of graphs which are derived from equal-distance partitioning of the phase spaces of systems. In addition, for one system which embeds into the other, we show that the comparison of these two systems by our method is an issue of subgraph matching.

2025

It is shown that for any positive integer k there exists a constant N = N (k) such that every 7-connected graph of order at least N contains K 3,k as a minor.

2025

This paper presents a computational toolkit developed for configurative architectural design, i.e. a computational design process, equipped with real-time space syntax analyses in a parametric CAD environment, which begins with defining the desired spatial configuration in form of a bubble diagram. The syntactic design methodology put forward by this toolkit is aimed at bridging the gap between space syntax as an analytic theory of architecture and architectural design practice. The toolkit has been made in an attempt to investigate the possibility of deriving at plan layout patterns through sketching spatial configuration using an ‘interactive bubble diagram’ that represents a spatial connectivity graph. In other words, we have worked on a way of reaching at concrete plan layouts from an abstract connectivity pattern as a graph. Beginning the design process with a graph allows for real-time feedback of Space Syntax measures such as integration, choice and difference factor. Besides...

2025, Standford Phd thesis, May

The ideas and results contained in this document are part of my thesis, which will be published as a Stanford computer science technical report in June 1999. ... I thank Madirakshi Das from the FOCUS project at University of... more

2025, HAL (Le Centre pour la Communication Scientifique Directe)

The capability to easily find useful services (software applications, software components, scientific computations) becomes increasingly critical in several fields. Current approaches for components retrieval are mostly limited to the matching of their inputs/outputs. To go beyond the limits of these approaches, a substantial effort has been done by different works on semantic web and ontologies by exploiting more knowledge on the semantics of the components. However, this effort still remains insufficient and does not fulfill user needs as many functional or quality aspects are hidden within the specification of components behavior. In this paper we argue that, in many situations, the component discovery process should be based on the specification of this behavior, that is the process model which describes each component. The idea behind is to develop matching techniques that operate on process models and allow delivery of partial matches and evaluation of semantic distance between these matches and the user requirements. Consequently, even if a service satisfying exactly the user requirements does not exist, the most similar ones will be retrieved and proposed for reuse by extension or modification. To do so, we reduce the problem of service behavioral matching to a graph matching problem and we adapt existing algorithms for this purpose.

2025, HAL (Le Centre pour la Communication Scientifique Directe)

The capability to easily find useful services (software applications, software components, scientific computations) becomes increasingly critical in several fields. Current approaches for services retrieval are mostly limited to the matching of their inputs/outputs. Recent works have demonstrated that this approach is not sufficient to discover relevant components. In this paper we argue that, in many situations, the service discovery should be based on the specification of service behavior (in particular, the conversation protocol). The idea behind is to develop matching techniques that operate on behavior models and allow delivery of partial matches and evaluation of semantic distance between these matches and the user requirements. Consequently, even if a service satisfying exactly the user requirements does not exist, the most similar ones will be retrieved and proposed for reuse by extension or modification. To do so, we reduce the problem of behavioral matching to a graph matching problem and we adapt existing algorithms for this purpose. A prototype is presented (available as a web service) which takes as input two conversation protocols and evaluates the semantic distance between them; the prototype provides also the script of edit operations that can be used to alter the first model to render it identical with the second one.

2025, Discrete Mathematics

In this paper we present a characterization of connected graphs of order (k + 1)n with k-covering number n, a characterization of trees in which the k-packing and k-covering numbers are the same, and we prove that the smallest number of subgraphs most k which cover the vertices of a block graph equals the k-packing number. of diameter at * This research was partially supported by the Heinrich Hertz Foundation and it was carried out while the author was visiting the Technical University of Aachen.

2025, 2010 IEEE Computer Society Conference on Computer Vision and Pattern Recognition

In this paper, we propose a high-order graph matching formulation to address non-rigid surface matching. The singleton terms capture the geometric and appearance similarities (e.g., curvature and texture) while the high-order terms model the intrinsic embedding energy. The novelty of this paper includes: 1) casting 3D surface registration into a graph matching problem that combines both geometric and appearance similarities and intrinsic embedding information, 2) the first implementation of high-order graph matching algorithm that solves a non-convex optimization problem, and 3) an efficient two-stage optimization approach to constrain the search space for dense surface registration. Our method is validated through a series of experiments demonstrating its accuracy and efficiency, notably in challenging cases of large and/or non-isometric deformations, or meshes that are partially occluded.

2025, Discrete Mathematics

Consider the family of all finite graphs with maximum degree ∆(G) < d and matching number ν(G) < m. In this paper we give a new proof to obtain the exact upper bound for the number of edges in such graphs and also characterize all the cases when the maximal graph is unique. We also provide a new proof of Gallai's lemma concerning factor critical graphs.

2025, Lecture Notes in Computer Science

This paper describes a complete system allowing automatic recognition of the main sulci of the human cortex. This system relies on a preprocessing of MR images leading to abstract structural representations of the cortical folding. The representation nodes are cortical folds, which are given a sulcus name by a contextual pattern recognition method. This method can be interpreted as a graph matching approach, which is driven by the minimization of a global function made up of local potentials. Each potential is a measure of the likelihood of the labelling of a restricted area. This potential is given by a multi-layer perceptron trained on a learning database. A base of 26 brains manually labelled by a neuroanatomist is used to validate our approach. The whole system developed for the right hemisphere is made up of 265 neural networks.

2025, 2010 20th International Conference on Pattern Recognition

In the context of unsupervised clustering, a new algorithm for the domain of graphs is introduced. In this paper, the key idea is to adapt the mean-shift clustering and its variants proposed for the domain of feature vectors to graph clustering. These algorithms have been applied successfully in image analysis and computer vision domains. The proposed algorithm works in an iterative manner by shifting each graph towards the median graph in a neighborhood. Both the set median graph and the generalized median graph are tested for the shifting procedure. In the experiment part, a set of cluster validation indices are used to evaluate our clustering algorithm and a comparison with the well-known Kmeans algorithm is provided.

2025

L’alignement de phrases à partir de textes bilingues consiste à reconnaître les phrases qui sont traductions les unes des autres. Cet article présente une nouvelle approche pour aligner les phrases d’un corpus parallèle. Cette approche est basée sur la recherche crosslingue d’information et consiste à construire une base de données des phrases du texte cible et considérer chaque phrase du texte source comme une requête à cette base. La recherche crosslingue utilise un analyseur linguistique et un moteur de recherche. L’analyseur linguistique traite aussi bien les documents à indexer que les requêtes et produit un ensemble de lemmes normalisés, un ensemble d’entités nommées et un ensemble de mots composés avec leurs étiquettes morpho-syntaxiques. Le moteur de recherche construit les fichiers inversés des documents en se basant sur leur analyse linguistique et retrouve les documents pertinents à partir de leur indexes. L’aligneur de phrases a été évalué sur un corpus parallèle Arabe-F...

2025

Dans cet article, nous nous intéressons à l'utilisation de la translittération arabe pour l'amélioration des résultats d'une approche linguistique d'alignement de mots simples et composés à partir de corpus de textes parallèles français-arabe. Cette approche utilise, d'une part, un lexique bilingue et les caractéristiques linguistiques des entités nommées et des cognats pour l'alignement de mots simples, et d'autre part, les relations de dépendance syntaxique pour aligner les mots composés. Nous avons évalué l'aligneur de mots simples et composés intégrant la translittération arabe en utilisant deux procédés : une évaluation de la qualité d'alignement à l'aide d'un alignement de référence construit manuellement et une évaluation de l'impact de cet alignement sur la qualité de la traduction en faisant appel au système de traduction automatique statistique Moses. Les résultats obtenus montrent que la translittération améliore aussi bien la qualité de l'alignement que celle de la traduction.

2025, Research Square (Research Square)

Over the past era, subgraph mining from a large collection of graph database is a crucial problem. Existing works on subgraph mining is based on the threshold value, which returns similar graphs for a query graph. However, the number of graphs in the answer set for the same threshold can vary in terms of structure and context. In addition, scalability is another big problem due to insufficient storage.Further, it can suffer from security issues. In a distributed environment, since more queries come from different users, it is possible for the attackers to access the graph. These three problems highly exist in the current subgraph mining. To address this downside, our proposed work introduces aBlockchain-based Triune Layered Architecture for authenticated query search in the large scale dynamic graphs. The two fold process is handled in BTLA-LSDG: graph indexing and authenticated query search (query processing), which are implemented in triune layers (Data Generation Layer, Data Storage Layer, and Service Layer). Initially, data owners are authenticated to blockchain using Four-Q-Curve algorithm. The graph index is constructed by data owners and merged graph index is constructed by service providers. Based on the uploaded graph index, hash index is constructed using SHA-3. The hash index is fed into blockchain and form Dendrimer -Fractal Index. On the other hand, data user submits query with authentication. For every authenticated query, the four fold process is handled. Firstly, Multi-Constraint based Belief Entropy function is used for feature sets computation for a given query. Then Dual Similarity based MapReduce helps inmapping and reducing the relevant subgraphs with the use of optimal feature sets. Thirdly, Recurrent Neural Network (RNN)is used for subgraph isomorphic testing. Finally, graph index refinement process is undertaken to improve the query results. For this, query error is computed for each user's query at the end of retrieval. With respect to query error, fuzzy logic is used to refine the index of graph dynamically. This experiment is implemented using Hadoop environment and the results show better efficiency in terms of Scalability, Security and Storage. Further, it is tested with Precision, Recall, F-measure, Accuracy, Error Rate, Query Response Time and Positive Results.

2025, IEEE Transactions on Robotics

2025, Mémoire Master Informatique

The continuous growth of data on the Web and the increasing number of heterogeneous databases pose significant integration challenges. These databases are often distributed and structured differently (structural heterogeneity) or... more

2025, IEEE Transactions on Information Theory

We present a theory for constructing linear subspace approximations to face recognition algorithms and empirically demonstrate that a surprisingly diverse set of face recognition approaches can be approximated well using a linear model. A linear model, built using a training set of face images, is specified in terms of a linear subspace spanned by, possibly non-orthogonal, vectors. We divide the linear transformation used to project face images into

2025

through the course of my PhD. Above all and the most needed, he provided me unflinching encouragement and support in numerous ways. His truly scientific intuition and passion towards research inspires and enriches my growth as a student and a researcher. I am indebted to him more than he knows. I gratefully acknowledge Prof. Rangachar Kasturi for his supervision, support and often crucial advice to this dissertation and my overall research. His involvement and originality has triggered and nourished my intellectual maturity that I will benefit from for a long time to come. I am extraordinarily fortunate in having Prof. Rangachar Kasturi as my co-major professor. I am deeply indebted to Prof. Dmitry Goldgof, Prof. Ravi Sankar, and Prof. Dmitry Khavinson for their constructive comments on this dissertation. I am thankful that in the midst of all their activities, they accepted to be members of my PhD committee. It was a pleasure and honor to work with my committee members. I am also thankful to Vasant Manohar, Himanshu Vajaria, Tanmoy Islam, Dr. Padmanabhan Soundararajan and other colleagues for their helpful and willing interactions during the numerous discussions in our lab. Warm acknowledgments are also owed to many friends at the University of South Florida, Tampa, whose presence and encouragement was not only helpful and memorable, but kept me refreshed and dedicated to this task. Furthermore, I would like to thank the friendly and helpful staff of Computer Science department for providing me a smooth working environment. Finally, I would like to extend my deepest gratitude to my dad and brother and my friends for always being there in perplexing situations and adding color to the life through their love and affection.

2024

Selective attention is one of the tasks humans solve with great ease, still in computer simulations of human cognition this is a very complicated problem. In humanoid research it even becomes more complicated due to physical restrictions of hardware. Compared to a human, camera's, e.g., have small visual fields and low resolution while motion causes a lot of noise, which makes audition a more complicated task. Combining vision and audition in humanoids is beneficial for both cues: vision because it does not suffer from noise, while audition is not restricted to an approximately 40 • × 40 • receptive field area, neither to partly or fully occluded objects. Low localization accuracy of both human (±8 • ) and artificial (±10 • ) audition systems can be compensated for by using vision. In this paper we propose a model that simulates selective attention by integrating vision and audition. A learning mechanism is incorporated as well to make the model adaptive to any arbitrary scene. The input of the model is formed by specific and robust features that are extracted from a huge amount of sensor data, hence part of the paper will focus on feature extraction. Audition is employed to improve selective attention because objects can be occluded or outside the visual field of a camera or human vision. Visual fields can be made wider by lenses, but never reach the full 360 degrees, hence a map is needed. This map contains information about all recognized objects over time, where objects are represented by features in a symbolic description. This map, in fact, represents a kind of artificial (temporal) memory. The location information of the objects (given by real world coordinates) is stored in the map as well. Also features from both vision and audition cues are integrated in this map. Storing information over time in such a map facilitates and speeds up the selective attention model. The map can be easily extended to incorporate extracted features from other types of sensors. In a simple natural environment the functionality of the model as well as the symbiosis between vision and audition are illustrated. The scenario will show that interaction between vision and audition is beneficial which is found rarely in literature. Promising results of the scenario show that audition was needed to localize an initially invisible object, while vision after that was used to accurately localize the object.

2024, arXiv (Cornell University)

A theta graph, denoted θ a,b,c , is a graph of order a + b + c -1 consisting of a pair of vertices and three independent paths between them of lengths a, b, and c. We provide a complete characterization of graphs that do not contain a large θ a,b,c as a topological minor. More specifically, we describe the structure of θ 1,2,t -, θ 2,2,t -, θ 1,t,t -, θ 2,t,t -, and θ t,t,t -free graphs where t is large. The main result is a characterization of θ t,t,t -free graphs for large t. The 3-connected θ t,t,t -free graphs are formed by 3-summing graphs without a long path to certain planar graphs. The 2-connected θ t,t,t -free graphs are then built up in a similar fashion by 2-and 3-sums. This result implies a well-known theorem of Robertson and Chakravarti on graphs that do not have a bond containing three specified edges.

2024, FUDMA JOURNAL OF SCIENCES

This paper reviews the theory of matrices and determinants. Matrix and determinant are nowadays considered inseparable to some extent, but the determinant was discovered over two centuries before the term matrix was coined. Our review associate determinant with the matrix as part of linear systems but not with polynomials. Thus, the paper first gives the background on matrix with vast applications in all fields of study and then reviews the history of determinants which is based on its major contributors in chronological order from the sixteenth century to the twenty-first century

2024, Mathematics Interdisciplinary Research

Consider a graph G = (V (G), E(G)), where a perfect matching in G is defined as a subset of independent edges with |V (G)| 2 elements. A global forcing set is a subset S of E such that no two disjoint perfect matchings of G coincide on it. The minimum cardinality of global forcing sets of G is called the global forcing number (GFN for short). This paper addresses the NP-hard problem of determining the global forcing number for perfect matchings. The focus is on a Genetic Algorithm (GA) that utilizes binary encoding and standard genetic operators to solve this problem. The proposed algorithm is implemented on some chemical graphs to illustrate the validity of the algorithm. The solutions obtained by the GA are compared with the results from other methods that have been presented in the literature. The presented algorithm can be applied to various bipartite graphs, particularly hexagonal systems. Additionally, the results of the GA improve some results that have already been presented for finding GFN.

2024, HAL (Le Centre pour la Communication Scientifique Directe)

Les utilisateurs d'une base de connaissances sont confrontés à un grand volume de données dont ils peuvent ignorer la structure sous-jacente. Ainsi, ils peuvent commettre des erreurs dans la formulation de leurs requêtes et obtenir des réponses non satisfaisantes. Nous nous intéressons ici au cas particulier du problème des réponses pléthoriques, où une requête produit beaucoup plus de résultats que n'attendait l'utilisateur. L'approche la plus connue pour traiter ce problème, la méthode dite top-K, consiste à classer les résultats pour ne retourner que les meilleures réponses. Cependant, si la requête comporte de mauvaises préconceptions, cette stratégie ne règle pas la source du problème et donc ne constitue pas une solution satisfaisante. Nous proposons donc une nouvelle méthode coopérative, permettant aux utilisateurs de comprendre l'origine des réponses pléthoriques de leur requête. Pour cela nous fournissons deux informations : (i) les parties minimales de la requête entraînant des réponses pléthoriques, et (ii) les parties maximales de la requête dont les réponses ne sont pas pléthoriques. Pour identifier ces deux informations, nous proposons deux algorithmes et montrons leur efficacité par rapport à une méthode naïve en utilisant des données synthétiques et réelles.

2024, Pattern Recognition

This paper presents a new method of filtering graphs to check exact graph isomorphism and extracting their mapping. Each graph is modeled by a resistive electrical circuit using the Conductance Electrical Model (CEM). By using this model, a necessary condition to check the isomorphism of two graphs is that their equivalent resistances have the same values, but this is not enough, and we have to look for their mapping to find the sufficient condition. We can compute the isomorphism between two graphs in O(N 3), where N is the order of the graph, if their star resistance values are different, otherwise the computational time is exponential, but only with respect to the number of repeated star resistance values, which usually is very small. We can use this technique to filter graphs that are not isomorphic and in case that they are, we can obtain their node mapping. A distinguishing feature over other methods is that, even if there exits repeated star resistance values, we can extract a partial node mapping (of all the nodes except the repeated ones and their neighbors) in O(N 3). The paper presents the method and its application to detect isomorphic graphs in two well know graph databases, where some graphs have more than 600 nodes.

2024, Lecture Notes in Computer Science

The aim of this article is to purpose a distance measure between Attributed Graphs (AGs) and Second-Order Random Graphs (SORGs) for recognition and classification proposes. The basic feature of SORGs is that they include both marginal probability functions and joint probability functions of graph elements (vertices or arcs). This allows a more precise description of both the structural and semantic information contents in a set (or cluster) of AGs and, consequently, an expected improvement in graph matching and object recognition. The distance measure is derived from the probability of instantiating a SORG into an AG. SORGs are shown to improve the performance of other random graph models such as FORGs and FDGs and also the direct AG-to-AG matching in two experimental recognition tasks.

2024

In this paper we consider two existing methods to generate a representative of a given set of graphs, that satisfy the following two conditions. On the one hand, that they are applicable to graphs with any kind of labels in nodes and edges and on the other hand, that they can handle relatively large amount of data. Namely, the approximated algorithms to compute the Median Graph via graph embedding and a new method to compute the Barycenter Graph. Our contribution is to give a new algorithm for the barycenter computation and to compare it to the median Graph. To compare these two representatives, we take into account algorithmic considerations and experimental results on the quality of the representative and its robustness, on several datasets.

2024, IEEE Data(base) Engineering Bulletin

Similarity search is a general class of problems in which a given object, called a query object, is compared against a collection of objects in order to retrieve those that most closely resemble the query object. This paper reviews recent work on an instance of this class of problems, where the objects in question are business process models. The goal is to identify process models in a repository that most closely resemble a given process model or a fragment thereof.

2024, Applied Mathematics and Computation

The eccentricity of a vertex is the maximum distance from it to another vertex, and the average eccentricity of a graph is the mean eccentricity of a vertex. In this paper we introduce average edge and average vertex-edge mean eccentricities of a graph. Moreover, relations among these eccentricities for trees are provided as well as formulas for line graphs and cartesian product of graphs.

2024, Tetrahedron Computer Methodology

In the context of automatic knowledge acquisition for computer-assisted synthesis planning, this paper presents an efficient algorithm for the identification of the maximal common substructures between reaction graphs. The terms of the problem are first completely specified. Then, the method used to solve it is presented and developed step by step. The formal algorithm is proposed as an appendix.

2024

This paper presents an I/O efficient algorithm for graph pattern matching problem. It is based on decision tree approach proposed by B. T. Messmer and H. Bunke. In that paper, if the time needed for preprocessing is neglected, the computational complexity of their approach is only polynomial in the number of input graph vertices. However, the decision tree is of exponential size. It's not practical for the graphs with large size.. In the new algorithm, we increases the preprocessing time as well as space complexity, it can remarkably reduces the n umber of I/Os and keeps the same time complexity. The algorithm is improved here to reduce its I/O complexity and to achieve a better performance on large graphs.

2024, Arxiv preprint arXiv:1002.0286

In the problem Max Lin, we are given a system $ Az= b $ of $ m $ linear equations with $ n $ variables over mathbbF_2\ mathbb {F} _2 mathbbF_2 in which each equation is assigned a positive weight and we wish to find an assignment of values to the variables in order to maximize the total weight of satisfied equations. Max Lin Above Average (MLAA) is a parameterized version of Max Lin introduced by Mahajan et al.(Proc. IWPEC'06 and J. Comput. Syst. Sci. 75, 2009). In MLAA all weights are integral and we wish to decide whether there is an ...

2024, Applied Mathematics Letters

We outline a class of graph similarity measures that uses the structural similarity of local neighborhoods to derive pairwise similarity scores for the nodes of two different graphs, and present a related similarity measure that uses a linear update to generate both node and edge similarity scores. This measure is then applied to the task of graph matching.