Search

The large number of scientific publications around the world is increasing at a rate of approximately 4%–5% per year. This fact has resulted in the need for tools that deal with relevant and high-quality publications. To address this necessity, search and reference management tools that include some recommendation algorithms have been developed. However, many of these solutions are proprietary tools and the full potential of recommender systems is rarely exploited. There are some solutions which provide recommendations for specific domains, by using ad-hoc resources. Furthermore, some other systems do not consider any personalization strategy to generate the recommendations. This paper presents ArZiGo , a web-based full prototype system for the search, management, and recommendation of scientific articles, which feeds on the Semantic Scholar Open Research Corpus, a corpus that is growing continually with more than 190M papers from all fields of science so far. ArZiGo combines different recommendation approaches within a hybrid system, in a configurable way, to recommend those papers that best suit the preferences of the users. A group of 30 human experts has participated in the evaluation of 500 recommendations in 10 research areas, 7 of which belong to the area of Computer Science and 3 to the area of Medicine, obtaining quite satisfactory results. Besides the appropriateness of the articles recommended, the execution time of the implemented algorithms has also been analyzed. • A web system for the search, management, and recommendation of scientific articles. • A hybrid and multidisciplinary scientific article recommendation system. • A modular and scalable recommendation system. • Use of the Semantic Scholar Open Research Corpus as a corpus of articles. [ABSTRACT FROM AUTHOR]

In this paper, we discuss methods to assess the interestingness of a query in an environment of data cubes. We assume a hierarchical multidimensional database, storing data cubes and level hierarchies. We start with a comprehensive review of related work in the fields of human behavior studies and computer science. We define the interestingness of a query as a vector of scores along different aspects, like novelty, relevance, surprise and peculiarity and complement this definition with a taxonomy of the information that can be used to assess each of these aspects of interestingness. We provide both syntactic (result-independent) and extensional (result-dependent) checks, measures and algorithms for assessing the different aspects of interestingness in a quantitative fashion. We also report our findings from a user study that we conducted, analyzing the significance of each aspect, its evolution over time and the behavior of the study's participants. [ABSTRACT FROM AUTHOR]

Event sequence data is increasingly available. Many business operations are supported by information systems that record transactions, events, state changes, message exchanges, and similar elements. This observation also applies to various industries, including production, logistics, healthcare, financial services, and education. The variety of application areas explains that techniques for event sequence data analysis have been developed rather independently in different fields of computer science. Most prominent are contributions from information visualization and from process mining. So far, the contributions from these two fields have neither been compared nor have they been mapped to an integrated framework. Such intransparency is problematic since it bears the risk of opportunities of integration are missed and concepts established in one field are independently reinvented in the other one. In this paper, we develop the Event Sequence Visualization framework (ESeVis) that gives due credit to the traditions of both fields. Our mapping study provides an integrated perspective on both fields and identifies potential for synergies for future research. • We propose the ESeVis Framework to categorize visualizations of event sequence data. • We review the literature of event sequence data visualizations. • Instance representations of event sequences are mostly from information visualization. • Process mining focuses on generating formal models. • Potential for synergy of process mining and information visualization. [ABSTRACT FROM AUTHOR]

In this paper we propose, motivate and solve multiple bichromatic mutual nearest neighbor queries in the plane considering multiplicative weighted Euclidean distances. Given two sets of facilities of different types, a multiple bichromatic mutual ( k , k ′ ) -nearest neighbor query finds pairs of points, one of each set, such that the point of the first set is a k -nearest neighbor of the point of the second set and, at the same time, the point of the second set is a k ′ -nearest neighbor of the point of the first set. These queries find applications in collaborative marketing and prospective data analysis, where facilities of one type cooperate with facilities of the other type to obtain reciprocal benefits. We present a sequential and a parallel algorithm, to be run on the CPU and on a Graphics Processing Unit, respectively, for solving multiple bichromatic mutual nearest neighbor queries. We also present the time and space complexity analysis of both algorithms, together with their theoretical comparison. Finally, we provide and discuss experimental results obtained with the implementation of the proposed sequential and a parallel algorithm. [ABSTRACT FROM AUTHOR]

Abstract: Many recent applications involve processing and analyzing uncertain data. In this paper, we combine the feature of top-k objects with that of skyline to model the problem of top-k skyline objects against uncertain data. The problem of efficiently computing top-k skyline objects on large uncertain datasets is challenging in both discrete and continuous cases. In this paper, firstly an efficient exact algorithm for computing the top-k skyline objects is developed for discrete cases. To address applications where each object may have a massive set of instances or a continuous probability density function, we also develop an efficient randomized algorithm with an guarantee. Moreover, our algorithms can be immediately extended to efficiently compute p-skyline; that is, retrieving the uncertain objects with skyline probabilities above a given threshold. Our extensive experiments on synthetic and real data demonstrate the efficiency of both algorithms and the randomized algorithm is highly accurate. They also show that our techniques significantly outperform the existing techniques for computing p-skyline. [Copyright &y& Elsevier]

Abstract: A suffix tree is a fundamental data structure for string searching algorithms. Unfortunately, when it comes to the use of suffix trees in real-life applications, the current methods for constructing suffix trees do not scale for large inputs. As suffix trees are larger than the input sequences and quickly outgrow the main memory, the first attempts at building large suffix trees focused on algorithms which avoid massive random access to the trees being built. However, all the existing practical algorithms perform random access to the input string, thus requiring in essence that the input be small enough to be kept in main memory. The constantly growing pool of string data, especially biological sequences, requires us to build suffix trees for much larger strings. We are the first to present an algorithm which is able to construct suffix trees for input sequences significantly larger than the size of the available main memory. Both the input string and the suffix tree are kept on disk and the algorithm is designed to avoid multiple random I/Os to both of them. 1 [1] The preliminary version of this paper was presented as a short paper at CIKM 2009 conference. As a proof of concept, we show that our method allows to build the suffix tree for 12GB of real DNA sequences in 26h on a single machine with 2GB of RAM. This input is four times the size of the Human Genome, and the construction of suffix trees for inputs of such magnitude was never reported before. [Copyright &y& Elsevier]

Abstract: A visible k nearest neighbor (Vk NN) query retrieves k objects that are visible and nearest to the query object, where “visible” means that there is no obstacle between an object and the query object. Existing studies on the Vk NN query have focused on static data objects. In this paper we investigate how to process the query on moving objects continuously. We propose an effective filtering-and-refinement framework for evaluating this type of queries. We exploit spatial proximity and visibility properties between the query object and data objects to prune search space under this framework. A detailed cost analysis and a comprehensive experimental study are conducted on the proposed framework. The results validate the effectiveness of the pruning techniques and verify the efficiency of the proposed framework. The proposed framework outperforms a straightforward solution by an order of magnitude in terms of both communication and computation costs. [Copyright &y& Elsevier]

Abstract: An efficient and universal similarity search solution is a holy grail for multimedia information retrieval. Most similarity indexes work by mapping the original multimedia objects into simpler representations, which are then searched by proximity using a suitable distance function. In this paper we introduce a novel representation of the objects as sets of integers, with a distance that is computed using set operations. This allows us to use compressed inverted indexes, which have become a mature technology that excels in this type of search. Such indexes allow processing queries in main memory even for very large databases, so that the disk is accessed only to verify a few candidates and present the results. We show that our technique achieves very good speed/compression/recall tradeoffs. As an example, to reach 92% recall in 30-nearest neighbor searches, an index using 1 to 2.5bytes per object inspects less than 0.6% of the actual objects. Furthermore, the ratio between the distances to the actual nearest neighbors and those reported by our algorithm is very close to 1. [Copyright &y& Elsevier]

Influence Maximization Problem (IMP) is selecting a seed set of nodes in the social network to spread the influence as widely as possible. It has many applications in multiple domains, e.g., viral marketing is frequently used for new products or activities advertisement. While it is a classic and well-studied problem in computer science, unfortunately, all those proposed techniques are compromising among time efficiency, memory consumption, and result quality. In this paper, we conduct comprehensive experimental studies on the state-of-the-art IMP approximate approaches to reveal the underlying trade-off strategies. Interestingly, we find that even the state-of-the-art approaches are impractical when the propagation probability of the network have been taken into consideration. With the findings of existing approaches, we propose a novel residual-based approach (i.e., RCELF) for IMP , which (i) overcomes the deficiencies of existing approximate approaches, and (ii) provides theoretical guaranteed results with high efficiency in both time- and space-perspectives. We demonstrate the superiority of our proposal by extensive experimental evaluation on real datasets. • We reveal the trade-off strategies among the approximate approaches for IMP. • An effective and efficient approximate algorithm called RCELF is proposed. • The performance of RCELF is extensively evaluated on 5 real-world datasets. [ABSTRACT FROM AUTHOR]

Abstract: Companies have to adhere to compliance requirements. The compliance analysis of business operations is typically a joint effort of business experts and compliance experts. Those experts need to create a common understanding of business processes to effectively conduct compliance management. In this paper, we present a technique that aims at supporting this process. We argue that process templates generated out of compliance requirements provide a basis for negotiation among business and compliance experts. We introduce a semi-automated and iterative approach to the synthesis of such process templates from compliance requirements expressed in Linear Temporal Logic (LTL). We show how generic constraints related to business process execution are incorporated and present criteria that point at underspecification. Further, we outline how such underspecification may be resolved to iteratively build up a complete specification. For the synthesis, we leverage existing work on process mining and process restructuring. However, our approach is not limited to the control-flow perspective, but also considers direct and indirect data-flow dependencies. Finally, we elaborate on the application of the derived process templates and present an implementation of our approach. [Copyright &y& Elsevier]

Abstract: In recent years, the research community has introduced various methods for processing skyline queries in road networks. A skyline query retrieves the skyline points that are not dominated by others in terms of static and dynamic attributes (i.e., the road distance). This paper addresses the issue of efficiently processing continuous skyline queries in road networks. Two novel and important distance-based skyline queries are presented, namely, the continuous query () and the continuous k nearest neighbor-skyline query (Cknn-SQ). A grid index is first designed to effectively manage the information of data objects and then two algorithms are proposed, the algorithm and the algorithm, which are combined with the grid index to answer the . Similarly, the Cknn-SQ algorithm and the Cknn-SQ + algorithm are developed to efficiently process the Cknn-SQ. Extensive experiments using real road network datasets demonstrate the effectiveness and the efficiency of the proposed algorithms. [Copyright &y& Elsevier]

Abstract: Open ontology learning is the process of extracting a domain ontology from a knowledge source in an unsupervised way. Due to its unsupervised nature, it requires filtering mechanisms to rate the importance and correctness of the extracted knowledge. This paper presents OntoCmaps, a domain-independent and open ontology learning tool that extracts deep semantic representations from corpora. OntoCmaps generates rich conceptual representations in the form of concept maps and proposes an innovative filtering mechanism based on metrics from graph theory. Our results show that using metrics such as Betweenness, PageRank, Hits and Degree centrality outperforms the results of standard text-based metrics (TF-IDF, term frequency) for concept identification. We propose voting schemes based on these metrics that provide a good performance in relationship identification, which again provides better results (in terms of precision and F-measure) than other traditional metrics such as frequency of co-occurrences. The approach is evaluated against a gold standard and is compared to the ontology learning tool Text2Onto. The OntoCmaps generated ontology is more expressive than Text2Onto ontology especially in conceptual relationships and leads to better results in terms of precision, recall and F-measure. [Copyright &y& Elsevier]

Abstract: Modularization is a widely advocated mechanism to manage a business process model''s size and complexity. However, the widespread use of subprocesses in models does not rest on solid evidence for its benefits to enhance their comprehension, nor are the criteria clear how to identify subprocesses. In this paper, we describe an empirical investigation to test the effectiveness of using subprocesses in real-life process models. Our results suggest that subprocesses may foster the understanding of a complex business process model by their “information hiding” quality. Furthermore, we explored different categories of criteria that can be used to automatically derive process fragments that seem suitable to capture as subprocesses. From this exploration, approaches that consider the connectedness of subprocesses seem most attractive to pursue. This insight can be used to develop tool support for the modularization of business process models. [Copyright &y& Elsevier]

Abstract: Numerous privacy-preserving data publishing algorithms were proposed to achieve privacy guarantees such as . Many of them, however, were recently found to be vulnerable to algorithm-based disclosure—i.e., privacy leakage incurred by an adversary who is aware of the privacy-preserving algorithm being used. This paper describes generic techniques for correcting the design of existing privacy-preserving data publishing algorithms to eliminate algorithm-based disclosure. We first show that algorithm-based disclosure is more prevalent and serious than previously studied. Then, we strictly define Algorithm-SAfe Publishing (ASAP) to capture and eliminate threats from algorithm-based disclosure. To correct the problems of existing data publishing algorithms, we propose two generic tools to be integrated in their design: global look-ahead and local look-ahead. To enhance data utility, we propose another generic tool called stratified pick-up. We demonstrate the effectiveness of our tools by applying them to several popular algorithms: Mondrian, Hilb, and MASK. We conduct extensive experiments to demonstrate the effectiveness of our tools in terms of data utility and efficiency. [Copyright &y& Elsevier]

Abstract: In this paper, we study the problem of keyword proximity search in XML documents. We take the disjunctive semantics among the keywords into consideration and find top-k relevant compact connected trees (CCTrees) as the answers of keyword proximity queries. We first introduce the notions of compact lowest common ancestor (CLCA) and maximal CLCA (MCLCA), and then propose compact connected trees and maximal CCTrees (MCCTrees) to efficiently and effectively answer keyword proximity queries. We give the theoretical upper bounds of the numbers of CLCAs, MCLCAs, CCTrees and MCCTrees, respectively. We devise an efficient algorithm to generate all MCCTrees, and propose a ranking mechanism to rank MCCTrees. Our extensive experimental study shows that our method achieves both high efficiency and effectiveness, and outperforms existing state-of-the-art approaches significantly. [Copyright &y& Elsevier]

Abstract: Information technology is evolving from focusing on local systems to encompassing a more global interaction among multiple systems in enterprises and communities. On the one hand, new advances in the area of network communications have facilitated in some way the intercommunication among heterogeneous information systems located at different places. However, what is still missing is the possibility of a real and efficient interoperation among those systems in an open environment as the one favoured by Internet. On the other hand, agent technology provides platforms where cooperative work of information systems is concernable because of the software agents working on behalf of these information systems. But, nowadays that cooperation is in general restricted and requires a laborious a priori preparation. In this paper we present the features of a formal ontology that can play a relevant role in the development of a new kind of information systems interoperation frameworks. The ontology includes classes and properties for describing communication acts among agents. We claim that the communication acts ontology provides interoperability support due to the recognition of communication acts from one Agent Communication Language (acl) as instances of communication acts in another acl. Sometimes the comprehension will not be complete, but partial comprehension of the communication may be useful and preferable to the “not understood” answer given nowadays. Terms of the ontology are described as classes or properties using the Web Ontology Language owl. [Copyright &y& Elsevier]

Abstract: The notion of context appears in computer science, as well as in several other disciplines, in various forms. In this paper, we present a general framework for representing the notion of context in information modeling. First, we define a context as a set of objects, within which each object has a set of names and possibly a reference: the reference of the object is another context which “hides” detailed information about the object. Then, we introduce the possibility of structuring the contents of a context through the traditional abstraction mechanisms, i.e., classification, generalization, and attribution. We show that, depending on the application, our notion of context can be used as an independent abstraction mechanism, either in an alternative or a complementary capacity with respect to the traditional abstraction mechanisms. We also study the interactions between contextualization and the traditional abstraction mechanisms, as well as the constraints that govern such interactions. Finally, we present a theory for contextualized information bases. The theory includes a set of validity constraints, a model theory, as well as a set of sound and complete inference rules. We show that our core theory can be easily extended to support embedding of particular information models in our contextualization framework. [Copyright &y& Elsevier]

Specialization has been used in object-oriented technologies to provide a number of powerful benefits such as modularity, maintainability, and comprehensibility. For the most part, however, system behavior continues to be modeled using traditional tools such as state diagrams and dataflow diagrams, which remain outside the scope of the specialization hierarchy used to such advantage with objects. This paper presents a framework for extending the notion of specialization to these process representations by identifying a set of transformations which, when applied to a process description, always result in specialization. We then use this framework to define specialization for dataflow diagrams. We illustrate with specific examples that such a use of specialization is not only theoretically possible, but shows promise as a method for categorizing and analyzing processes. [Copyright &y& Elsevier]