Informatica

Semantic-based storage and retrieval of multimedia data requires accurate annotation of the data. Annotation can be done either manually or automatically. The retrieval performance of the manual annotation based approaches is quite good, as compared to approaches based on automatic annotation. However, manual annotation is time consuming and labor extensive. Therefore, it is quite difficult to apply this technique on huge volume of multimedia data. On the other hand, automatic annotation is commonly used to annotate the multimedia data based on low level features, which obviously lacks the semantic nature of the multimedia data. Yet, we have not come across with any such system which automatically annotate the multimedia data based on the extracted semantics accurately. In this paper, we have performed automatic annotation of the images by extracting their semantics (high level features) with the help of semantic libraries. Semantic libraries use semantic graphs. Each graph consists of related concepts along with their relationships. We have also demonstrated with the help of a case study that our proposed approach ensures an improvement in the semantic based retrieval of multimedia data.

The advance of the Web has significantly and rapidly changed the way of information organization, sharing and distribution. The next generation of the web, the semantic web, seeks to make information more usable by machines by introducing a more rigorous structure based on ontologies. In this context we try to propose a novel and integrated approach for a semi-automated extraction of ontology-based semantic web from data-intensive web application and thus, make the web content machine-understandable. Our approach is based on the idea that semantics can be extracted by applying a reverse engineering technique on the structures and the instances of HTML-forms which are the most convenient interface to communicate with relational databases on the current data-intensive web application. This semantics is exploited to produce over several steps, a personalised ontology.

In 2004, Abe et al. proposed a threshold signer-ambiguous signature scheme from variety of keys. Their scheme is a generalized case of the ring signature scheme, and it allows the key types to be based on the trapdoor one-way permutations (TOWP) or sigma-protocols including Schnorr's signature scheme. However, the signed message is public for all, which may result in disputes. In this paper, we present a novel threshold signer-ambiguous signature scheme, having the signed message concealed and keeping who the receivers are secret from variety of keys.

A modified version of the Bellare and Rogaway (1993) adversarial model is encoded using Asynchronous Product Automata (APA). A model checker tool, Simple Homomorphism Verification Tool (SHVT), is then used to perform state-space analysis on the Automata in the setting of planning problem. The three-party identity-based secret public key protocol (3P-ID-SPK) protocol of Lim and Paterson (2006), which claims to provide explicit key authentication, is used as a case study. We then refute its heuristic security argument by revealing a previously unpublished flaw in the protocol using SHVT. We then show how our approach can automatically repair the protocol. This is, to the best of our knowledge, the first work that integrates an adversarial model from the computational complexity paradigm with an automated tool from the computer security paradigm to analyse protocols in an artificial intelligence problem setting – planning problem – and, more importantly, to repair protocols.

In the paper, a cross-layer optimization between application layer and fabric layer is proposed. The aim is to optimize the end-to-end quality of the dynamic grid application as well as efficiently utilizing the grid resources. The application layer QoS and fabric layer QoS are closely interrelated in Grids since the upper layer service is based on the lower level's capabilities. A fabric level and application level QoS scheduling algorithm is proposed. We formulate the integrated design of resource allocation and user QoS satisfaction control into a constrained optimization problem. The optimization framework provides a layered approach to the sum utility maximization problem. The application layer adaptively adjusts user's resource demand based on the current resource conditions, while the fabric layer adaptively allocates CPU, storage and bandwidth required by the upper layer.

Business process engineering is an important part of the advanced enterprise engineering. One of the still open issues is the question how in the enterprise system design to reuse ontological knowledge about business processes. The paper proposes to consider a family of similar business processes as a generic process and to represent knowledge about generic processes in a domain independent way. It describes the main scheme for reuse of such a domain independent knowledge when developing enterprise-wide information systems (IS). The main attention is paid to the process configuration problem. In order to solve this problem, a configurator (human being or machine) must find a set of components that fit together to satisfy the problem specification. An approach based on Description Logics is proposed for this aim. The main contribution of the paper is the proposed process configuration technique.

The paper considers application of stochastic optimization to system of automatic recognition of ischemic stroke area on computed tomography (CT) images. The algorithm of recognition depends on five inputs that influence the results of automatic detection. The quality of recognition is measured by size of conjunction of ethalone image and the image calculated by the program of automatic detection. The method of Simultaneous Perturbation Stohastic Approximation algorithm with the Metropolis rule has been applied to the optimization of the quality of image recognition. The Monte-Carlo simulation experiment was performed in order to evaluate the properties of developed algorithm.

This paper proposes a reversible data hiding method for error diffused halftone images. It employs statistics feature of pixel block patterns to embed data, and utilizes the HVS characteristics to reduce the introduced visual distortion. The watermarked halftone image can be perfectly recovered if it is intact, only a secret key is required. The method is suitable for the applications where the content accuracy of the original halftone image must be guaranteed, and it is easily extended to the field of halftone image authentication.