Formal Verification and Performance Evaluation of User Query Pattern-Based Relational Schema-to-XML Schema Translation Algorithm

This paper proposes a new query pattern-based relational schema-to-XML schema translation (QP-T) algorithm to resolve implicit referential integrity issue. Various translation methods have been introduced on structural aspects and/or semantic aspects. However, most of conventional methods consider only explicit referential integrities specified by relational schema. It causes several problems such as incorrect transformation, abnormal relational model transition and so on. Researches about syntactic/semantic structure extraction also have been executed in reverse-engineering part. Many systems or algorithms suggested in Reverse Engineering researches are so complicate and not proper to RDB-to-XML translation. Some of them just consider syntactic structure extraction and others reflect every structure and constraints. That is, most of methods in reverse engineering part include unnecessary part. The QP-T algorithm analyzes query pattern and extract implicit referential integrities through equi-join between columns. The QP-T algorithm was based on a concept that columns related to equi-join in relational schema can have referential integrity. The most distinct contribution of QP-T algorithm was to enhance extraction of referential integrity relation information for translation. Therefore, the QP-T algorithm reflects not only explicit referential integrities but also implicit referential integrities during RDB-to-XML translation.

Fundamental notions of relative information capacity between database structures are studied in the context of the relational model. Four progressively less restrictive formal definitions of "dominance" between pairs of relational database schemata are given. Each of these is shown to capture intuitively appealing, semantically meaningful properties which are natural for measures of relative information capacity between schemata. Relational schemata, both with and without key dependencies, are studied using these notions. A significant intuitive conclusion concerns the informal notion of relative information capacity often suggested in the conceptual database literature, which is based on accessability of data via queries. Results here indicate that this notion is too general to accurately measure whether an underlying semantic connection exists between database schemata. Another important result of the paper shows that under any natural notion of information capacity equivalence, two relational schemata (with no dependencies) are equivalent if and only if they are identical (up to re-ordering of the attributes and relations). The approach and definitions used here can form part of the foundation for a rigorous investigation of a variety of important database problems involving data relativism, including those of schema integration and schema translation.

This paper proposes a new methodology for system engineering. It provides an integrated approach covering formal specification and performance evaluation. Therefore it associates the advantages of formal techniques that allow formal proof and automatic implementation with the benefits of performance evaluation. The basic idea is to abstract the relevant features of the system in the formal specification (structure, functional description), enhance it with relevant information for performance modeling (quality of service, operating load, processing architecture and processing constraints), and map them into a performance evaluation environment. In this paper, we develop the suitable extensions for the formal language SDL and apply them to an example: Transmission Control Protocol (TCP).

The main objective of congestion control is to best exploit the available network resources while preventing sustained overloads of network nodes and links. Appropriate congestion control mechanisms are essential to provide effcient operation of a network. Ensuring congestion control within vehicular ad hoc networks faces special challenges, due to the specificities of such environment (High mobility of nodes, high rate of topology changes, high variability in nodes density and neighborhood configuration, broadcast/geocast communication nature, etc.). In this context, we present in this paper a cooperative and fully distributed congestion control approach, based on dynamic scheduling and transmission of priority-based messages, to ensure reliable and safe communication architecture within VANET. Messages priorities are dynamically evaluated according to their types, the network context, and the neighboring nodes configuration. Considering the context of high reliability and real-time response required for intervehicular communications (including emergency breaking notification for example), we propose a complete validation method of our congestion control algorithms, taking into account reliability, temporal, and operational aspects.

A crucial component of quality management is assessment of personnel competency. Obtaining reliable results from the testing personnel in the andrology laboratory, often referred to as “andrologists,” requires attention to hiring, training, and performance evaluation. The perfect fit for an andrology laboratory may not be the most experienced individual but relies on character traits, including teamwork, integrity, confidence, and analytical thinking. Training the new employee begins with instructions covering the laboratory’s policies, chain of command, safety, compliance with regulations, and reliance on standard operating procedures. Approval of the technician to perform patient testing requires observation of trained andrologists, side-by-side testing, practice with semen, and testing under close supervision. Benchmarks of successful training are important in this process. Continuing education throughout a technician’s career will ensure that the knowledge base in the laboratory keeps up with modern methodology. Evaluation of personnel competence begins during training and is continuous throughout the andrologist’s career. Quality control (QC) of technical performance includes intra-laboratory evaluation of inter-technician variation, interlaboratory evaluation to ensure uniform results, and formal performance evaluation with goals for improved performance. This chapter discusses these aspects of personnel competency assessment, giving examples of personnel forms and QC results.

The rapid progress of quantum computing now poses a substantial security risk to the information infrastructures of various nations, which are fundamentally reliant on classical cryptographic systems. Encryption algorithms such as RSA, ECC, and, notably, Satyamani’s, Shor, and Grover algorithms are vulnerable to quantum attacks; indeed, these algorithms can compromise code creation and encryption protocols within seconds when subjected to powerful quantum computing devices. In response to this emerging threat, this paper presents the design and evaluation of a quantum-resilient cryptographic protocol suite intended for national information systems security. The proposed version integrates lattice-based key exchange and hash-based digital signatures, rendering it post-quantum and compatible with the existing Public Key Infrastructure (PKI) and network protocol stack. Formal security analysis and performance evaluation were conducted using simulated nationwide network environments. Experimental results demonstrate that the proposed scheme achieves a computational latency reduction of up to 45% compared to baseline post-quantum algorithms, while maintaining high resilience against both classical and quantum adversaries. The scalability test indicates that quantum-resilient cryptography can be deployed across various government apparatuses, promoting national cybersecurity and digital autonomy, while maintaining security and interoperability

Perspectives from the Bar: Attorney Attitudes on the Implementation of a Federal Judicial Evaluation Program

A class-based scheme for E-commerce web servers: Formal specification and performance evaluation

In this paper we constructed a formal performance model for a secure and scalable e-voting scheme known as DRE-i voting scheme. The well-known formal stochastic performance evaluation process algebra (PEPA) language and PEPA Eclipse plug-in were used to represent the voting scheme and analyse its performance characteristics. Timely responses of remote electronic voting protocols are important to increase voters’ confidence in e-voting systems. Therefore we evaluated the average response time that voters may observe when they cast their votes using remote electronic voting systems, such as DRE-i, and we also evaluated the throughput and queue length of the DRE-i server’s actions for different number of voters inside the DRE-i e-voting system. The performance evaluation of the DRE-i scheme reveals that PEPA language is efficient in investigating the performance properties of large scale e-voting schemes.

Why is the snowflake schema a good data warehouse design?

11 - Relational Languages

Optimising harvest strategies over multiple objectives and stakeholder preferences

The situation of telecommunications systems is rapidly evolving towards a state characterized by the presence of a multitude of services integrated in a single network structure. In order to ease their integration, it is important to provide an unambiguous description of the organization, of the functionality, and of the relationships existing among services. Since it is not possible to completely foresee the situation of services in the future, the description should be modular, so that the task of adding new services to an existing environment is simplified. Formal description techniques are languages designed to handle such descriptions. Their goal is to produce correct and unambiguous specifications, understanding and modeling the system and the domain within which it operates. Their input is a set of required statements and a conceptual overview of the system. Their output is a formal representation that captures the functional behavior. On the other hand, the throughput of physical networks is constantly growing, reaching the order of Gbit/s. In the meantime, services needing high throughput, like multimedia conferencing systems are being designed, creating a need for flexible, high performance communication systems. An important feature of new high speed services is their increased need for guarantees. Therefore, the use of powerful performance modeling techniques becomes of prime importance. Their goal is to obtain some notion of how the system will perform under a given set of conditions. Performance evaluation theorists have long been using system specifications to make a heuristic model of the system and then an analysis of the model. When system specifications exist, the question arises whether a more direct path to performance analysis can be found. Our scope is to provide a methodology that fully and consistently integrates formal specification and performance evaluation. A problem is that many of the bottlenecks and impediments to smooth data flow have to do with implementation issues not directly dealt within the system specification itself. Therefore, prior to generating a performance model, the formal specification should be enhanced with the relevant non-functional information. It is essential to assure a smooth specification of the non-functional information. Thus, it is necessary to consistently add this information to the formal specification. Besides, the extended formal method should focus on conserving the semantics of the original one, and on providing a coherent extension of the semantics and syntax for the new concepts. Since all relevant required information is integrated within the formal extended representation, we provide a mapping technique that translates the extended formal representation into a performance modeling conserving the properties of the formal model. In parallel to the development of a performance model, the formal model can be validated and verified, and their implementation can be tested for conformance towards the original formal model. Finally, the performance modelling is implemented in a programming language, and then simulated. The results from simulation can be reused as inputs for the optimization of the formal specification (functional optimization) or the extended formal model (design optimization). To sum up, the goal of this work is to: Define extensions to current formal methods that allow to enhance the formal specification with performance modeling related information. Develop a method to translate the extended formal specification into a performance modeling. Develop rules and guidelines to automatically implement the performance modeling for the purpose of a performance evaluation (we use the commercial tool Opnet). Develop a consistent and coherent methodology for the integration of performance modeling and formal specification.

In this paper, we develop techniques to produce interoperable queries with object and relational databases. A user poses a local query in a local query language, against a local object or relational schema. We transparently produce appropriate queries with respect to a remote target object or relational schema, corresponding to some remote database which contains data relevant to the user's query. Mapping knowledge to resolve representational heterogeneities in local and remote schemas is expressed in a canonical representation, CRmapping, and is independent of the particular data model. A canonical representation CRquery is also used to resolve heterogeneities of query languages. A set of heterogeneous transformation algorithms define the appropriate transformations from the local queries to the remote queries. The use of canonical representations (CR) allows us to represent queries independent of the particular query language, and to resolve representational conflicts in a uniform manner, independent of models and query languages.

Mirror reflections offer an intuitive and realistic Mixed Reality (MR) experience comparable to other MR interfaces. Their high visual fidelity, and the sensorimotor contingency from the reflected moving body, make the mirror an ideal instrument for MR movement guidance. The translucent two-way mirror display enables users to follow a virtual humanoid instructor’s movement accurately by visually matching it with their reflections. In this work, we conduct the first formal evaluation of movement acquisition performance with simple motor tasks, using visual guidance from an MR mirror and a humanoid virtual instructor. Our results of performance and subjective ratings indicate that, comparing with simulated virtual mirror and with traditional screen-based movement guidance, the real MR mirror yields better acquisition performance and stronger sense of embodiment with the reflection, for upper-body movement. But the benefits diminish with larger-range head movements. We provide design guidelines for future mirror movement guidance interfaces and MR mirror experiences at large.