Fundamenta Informaticae - Volume 138, issue 3

Authors: Armano, Giuliano

Article Type: Research Article

Abstract: Progressive filtering is a simple way to perform hierarchical classification, inspired by the behavior that most humans put into practice while attempting to categorize an item according to an underlying taxonomy. Each node of the taxonomy being associated with a different category, one may visualize the categorization process by looking at the item going downwards through all the nodes that accept it as belonging to the corresponding category. This paper is aimed at modeling the progressive filtering technique from a probabilistic perspective. As a result, the designer of a system based on progressive filtering should be facilitated in the task …of devising, training, and testing it. Show more

Keywords: Hierarchical Classification, Information Filtering

DOI: 10.3233/FI-2015-1213

Citation: Fundamenta Informaticae, vol. 138, no. 3, pp. 285-320, 2015

Authors: Bera, Sahadev | Biswas, Arindam | Bhattacharya, Bhargab B.

Article Type: Research Article

Abstract: Granular object segmentation is an important area of image processing, which has several practical applications in agriculture, food industry, geology, and forensics. In this paper, we present a simple algorithm for the analysis of granulometric images that consist of touching or overlapping convex objects such as coffee bean, food grain, nuts, blood cell, or cookies. The algorithm is based on certain underlying digital-geometric features embedded in their binary snapshots. The concept of an outer isothetic cover and the property of geometric convexity are used to extract the joining points (or concavity points) from the ensemble of objects. Next, a combinatorial …technique is employed to determine the separator of two overlapping or neighboring objects. This technique is fully automated and it needs only integer-domain computation. The termination time of the algorithm can be traded-off with the quality of segmentation by changing the resolution parameter. Experimental results for a variety of objects chosen from different application domains such as cell image, coffee-bean image and others demonstrate the efficiency and robustness of the proposed method compared to earlier watershed-based algorithms. Show more

Keywords: Granulometric image analysis, Digital geometry, Outer isothetic cover, Coffee bean segmentation, Combinatorial image analysis

DOI: 10.3233/FI-2015-1214

Citation: Fundamenta Informaticae, vol. 138, no. 3, pp. 321-338, 2015

Authors: Dąbrowski, Robert | Plandowski, Wojciech

Article Type: Research Article

Abstract: We describe an intersection of the family of expressible relations and another natural family of relations. This is the first result of this kind existing in the literature. To obtain it we extend a tool for proving nonexpressibility of languages to a tool for proving nonexpressibility of relations.

Keywords: combinatorics on words, word equations, expressible relations

DOI: 10.3233/FI-2015-1215

Citation: Fundamenta Informaticae, vol. 138, no. 3, pp. 339-350, 2015

Authors: Lang, Guangming | Li, Qingguo | Guo, Lankun

Article Type: Research Article

Abstract: The introduction of information system homomorphisms has made a substantial contribution to attribute reduction. However, the efforts made on homomorphisms are far from sufficient. This paper further investigates homomorphisms between covering approximation spaces. First, we introduce the concepts of upper and lower homomorphisms as well as homomorphisms in order to study the relationship between covering approximation spaces. Then we present the notions of covering approximation subspaces and product spaces. We also compress covering approximation spaces and covering information systems with the aim of attribute reduction. Afterwards, by utilizing the compressions of the original spaces and systems we compress the dynamic …covering approximation spaces and dynamic covering information systems. Several illustrative examples are employed to demonstrate that the homomorphisms provide an effective approach for compressing covering approximation spaces and covering information systems. Show more

Keywords: Compression, Covering approximation space, Covering information system, Homomorphism

DOI: 10.3233/FI-2015-1216

Citation: Fundamenta Informaticae, vol. 138, no. 3, pp. 351-371, 2015

Authors: Pham, Thi-Thiet

Article Type: Research Article

Abstract: Mining long frequent sequences that contain a combinatorial number of frequent subsequences or using very low support thresholds to mine sequential patterns is usually both time- and memory-consuming. The mining of closed sequential patterns, sequential generator patterns, and maximum sequences has been proposed to overcome this problem. Sequential generator patterns, when used together with closed sequential patterns, can provide additional information that closed sequential patterns alone cannot provide. Mining sequential generator patterns is thus an important task in data mining as well. This paper proposes an algorithm called MSGP-PreTree for mining all sequential generator patterns based on the prefix-tree structure. …The algorithm uses the characteristics of sequential generator patterns and sequence extensions to efficiently perform a depth-first search on a prefix tree. It also uses a vertical approach to list and count the supports of sequences based on the prime block encoding approach for representing candidate sequences and determining the frequencies of candidates. Besides, the search space of the MSGP-PreTree algorithm is much smaller than those of other algorithms because two pruning strategies are applied. Experimental results conducted on synthetic and real databases show that the proposed algorithm is effective than a previous one. Show more

Keywords: sequential pattern, sequential generator pattern, sequence database, prefix tree

DOI: 10.3233/FI-2015-1217

Citation: Fundamenta Informaticae, vol. 138, no. 3, pp. 373-386, 2015