Informatica

Glaucoma is one of the most insidious eye diseases the occurrence and progression of which a human does not feel. This article provides a brief overview of the eye nerve parameterization methods and algorithms. Parameterization itself is an important task that provides and uniquely defines the structure of the optic nerve disc and further can be used in disease detection or other studies that require a parametric estimate of the eye fundus pattern. So far, planimetric completely automated parameterization of excavation from eye fundus images has not been investigated in detail in the scientific literature. In this article, the authors describe an automated excavation and parameterization algorithm and make the correlation analysis of parameters obtained by both automated and interactive techniques. The obtained results are then compared with those produced by Optical Coherence and Heidelberg Retina Tomography. Finally, the article discusses glaucoma disease detection abilities using the estimated parameters of the eye fundus structures, obtained by different parameterization techniques.

In sport tournaments where teams compete in match play format, the pairing of players in matches is critical to the final outcomes. This paper presents simulation models using only commonplace spreadsheet software to analyze and compare strategies in such pairings based on actual or estimated performance of individual players. The approach can be a useful decision support tool for captains and coaches of competing teams in collegiate conferences, club leagues, or international sport tournaments.

Nowadays, ontologies play a central role in many computer science problems such as data modelling, data exchange, integration of heterogeneous data and models or software reuse. Yet, if many methods of ontology based conceptual data modelling have been proposed, only few attempts have been made to ontology axioms based modelling of business rules, which make an integral part of each conceptual data model. In this paper, we present the approach how ontology axioms can be used for business rules implementation. Our proposal we apply for the transformation of PAL (Protege Axiom Language) constraints (ontology axioms), which is based on KIF (Knowledge Interchange Format) and is part of KIF ontology, into OCL (Object Constraint Language) constraints, which are part of a UML class diagram. Z language is used to formalise the proposal and describe the transformation. The Axiom2OCL plug-in is created for automation of the transformation and a case study is carried out.

The article describes multi-function system testing based on fusion (or revelation) of clique-like structures. The following sets are considered: (i) subsystems (system parts or units/components/modules), (ii) system functions and a subset of system components for each system function, and (iii) function clusters (some groups of system functions which are used jointly). Test procedures (as units testing) are used for each subsystem. The procedures lead to an ordinal result (states, colors) for each component (e.g., ‘out of service’, ‘major faults’, ‘minor faults’, ‘trouble free service’). For each system function a graph over corresponding system components is examined while taking into account ordinal estimates/colors of the components. Further, an integrated graph for each function cluster is considered (this graph integrates the graphs for corresponding system functions). For the integrated graph structure revelation problems are under examination (revelation of some subgraphs which can lead to system faults). Numerical examples illustrate the approach and problems.

The paper deals with the problem of high-school time-tabling that is important in applications, but hard for solving. The algorithm is presented for timetabling based on Multi-start and Simulated Annealing with parameters adapted using the Bayes approach. The algorithm proposed is compared with other timetabling algorithms using the web-based software. A multi-start algorithm is a simple way to provide the convergence, if the number of uniformly distributed starting points is large. A disadvantage is slow convergence.

In this paper, we consider piecewise linear aggregates (PLA) and a possibility to use a linear temporal logic for analysis of their performance over finite structures (finite linear temporal logic (LTL)). We describe a calculus where the search is performed with respect to a context of the formula. An important aspect of finite LTL is the simplicity of its model of time and actions. PLA is used for description of numerous complex systems. The answers about the behavior of the aggregate are got by finding an interpretation in which all the formulas describing the work of the aggregate are true. This is illustrated by formalizing alternative bit protocol (ABP) task. We describe the ABP by putting it in the form of a planning problem. From the obtained model, we can find a finite sequence of actions to be executed in order to achieve the goal. In addition, an alternative bit protocol problem is described using the planning domain description language (PDDL). We report the results of experiments conducted using the LPG-TD planner.

Multisignature scheme allows a group of signers to generate a compact signature on a common document that certifies they endorsed the message. However, the existing state of the art multisignatures often suffers from the following problems: impractical key setup assumptions, loose security reductions and inefficient signature verification. In this paper, we propose a non-interactive multisignature scheme with tight security reduction in the random oracle model. Our proposed multisignatures address the above three problems by achieving: provable security in the plain public key model; tight security reduction under the standard Computational Diffie–Hellman (CDH) assumption and 𝒪(1) computational time for signature verification through pre-computation. Hence, our non-interactive multisignatures are of great use in routing authentication of networks.

Three main approaches presently dominate preferences derivation or evaluation process in decision analysis (selecting, ranking or sorting options, alternatives, actions or decisions): value type approach (a value function or an utility measure is derived for each alternative to represent its adequacy with decision goal); outranking methods (a pair comparison of alternatives are carried up under each attribute or criteria to derive a pre-order on the alternatives set); and decision rules approach (a set of decision rules are derived by a learning process from a decision table with possible missing data). All these approaches suppose to have a single decision objective to satisfy and all alternatives characterized by a common set of attributes or criteria. In this paper we adopt an approach that highlights bipolar nature of attributes with regards to objectives that we consider to be inherent to any decision analysis problem. We, therefore, introduce supporting and rejecting notions to describ attributes and objectives relationships leading to an evaluation model in terms of two measures or indices (selectability and rejectability) for each alternative in the framework of satisficing game theory. Supporting or rejecting degree of an attribute with regard to an objective is assessed using known techniques such as analytic hierarchy process (AHP). This model allows alternatives to be characterized by heteregeneous attributes and incomparability between alternatives in terms of Pareto-equilibria.

Revocation problem is a critical issue for key management of public key systems. Any certificate-based or identity (ID)-based public key systems must provide a revocation method to revoke misbehaving/compromised users from the public key systems. In the past, there was little work on studying the revocation problem of ID-based public key systems. Most recently, Tseng and Tsai presented a novel ID-based public key system with efficient revocation using a public channel, and proposed a practical revocable ID-based encryption (called RIBE). They proved that the proposed RIBE is semantically secure in the random oracle model. Although the ID-based encryption schemes based on the random oracle model can offer better performance, the resulting schemes could be insecure when random oracles are instantiated with concrete hash functions. In this paper, we employ Tseng and Tsai's revocable concept to propose a new RIBE without random oracles to provide full security. We demonstrate that the proposed RIBE is semantically secure against adaptive-ID attacks in the standard model.