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Lutess is a testing environment designed for synchronous software specified with Lustre, a synchronous data-flow language. It makes possible to automatically generate test input sequences in conformance with a specification of the software external behavior and of guiding directives such as operational profiles and behavioral patterns. Lutess deals with software and specifications involving only boolean inputs and outputs. In this paper we propose an extension of Lutess, using Constraint Logic Programming (CLP), making possible to deal with numeric inputs and outputs. In particular, we define an appropriate execution model for test input generation and show how test data generation according to the main guiding facilities of Lutess can still be performed. Furthermore, operational profile based generation becomes more powerful thanks to the introduction of CLP solvers capabilities which make possible to associate occurrence probabilities to any boolean expression.

Lutess is a testing environment designed for synchronous software specified with Lustre, a synchronous data-flow language widely used in safety critical domains such as avionics, energy and transport. Lutess automatically transforms the formal description of the program environment and properties to test generators that feed, on the fly, the program under test. A new version of Lutess has been recently developed, using Constraint Logic Programming. In this version, it is possible to take into account numeric input and output variables and to introduce hypotheses on the program under test. The input language of Lutess has been consequently extended. In this paper we present the new set of operators of the language and illustrate their execution semantics on a simple example.

The service which enables us to use computing as a service across a product is known as cloud computing. Nowadays the cloud computing paradigm has been receiving significant excitement and attention in technological sphere. Cloud computing shares different resources and information between different devices which are located in different places always based on internet connection. According to this, a cloud DBMS is a database management system which acts through cloud computing. It is worth mentioning that the number of these DBMS which act through cloud computing is expected to increase in the future. Based on related research and results, there is an increment of interest in outsourcing of DBMS tasks to third parties that can afford these tasks with low and cheap cost. In this paper, we discuss about DBMS as a cloud service, advantages and disadvantages, opportunities and limitations, and we focus on the way how to offer a cloud DBMS as one of the best services. We focus on three main characteristics of cloud computing which are considered as the most worried issues of cloud platform. We review cloud database challenges such as: internet speed, multi-tenancy, privacy and security. We also focus on the way how to opposite these challenges in order to provide a successful cloud database. At the end of this paper we explain a specific architecture of cloud DBMS which is known as SCALEDB. We focus on its layer which this architecture contains and the way how these layers works. We thus express the need for a new DBMS, designed specifically for cloud computing environments.

The security of message transmission is usually a challenge for its participants. Many available programs that work with audio data claim to enable secured communication, but usually do not show the details of the methods used for data encryption. For end users to be confident, it is essential to be aware of the methods and techniques used for data encryption and decryption. Elliptic curve cryptography, an approach to public key cryptography, is now commonly used in cryptosystems. Hence, in this paper we present a method for using elliptic curve cryptography in order to secure audio data communications. Furthermore, we present a tool that implements this method for encrypting an audio file, transmitting it through the network and decrypting the file at the other end.