104 research outputs found

    Contributions to the ecology of the Benthic macrofauna of the Bot River Estuary

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    This thesis forms part of a multi-disciplinary study of the Bot River estuary, situated between Kleinmond and Hawston on the southwest coast of the Cape Province, and falls within the framework of the investigation of all Cape estuaries, initiated by SANCOR and co-ordinated by the Estuarine and Coastal Research Unit of the CSIR. The motivation for the research program on the Bot River estuary, in particular, was the need to obtain detailed knowledge of its dynamics in order to be able to address its unique management problems

    Inconsistency-Tolerant Integrity Checking

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    All methods for efficient integrity checking require all integrity constraints to be totally satisfied, before any update is executed. However, a certain amount of inconsistency is the rule, rather than the exception in databases. In this paper, we close the gap between theory and practice of integrity checking, i.e., between the unrealistic theoretical requirement of total integrity and the practical need for inconsistency tolerance, which we define for integrity checking methods. We show that most of them can still be used to check whether updates preserve integrity, even if the current state is inconsistent. Inconsistency-tolerant integrity checking proves beneficial both for integrity preservation and query answering. Also, we show that it is useful for view updating, repairs, schema evolution, and other applications.Hendrik Decker has been supported by FEDER and the Spanish MEC grant TIN2006-14738-C02-01. Davide Martinenghi has been supported by the Search Computing (SeCo) project, funded by ERC under the 2008 Call for "IDEAS Advanced Grants." The authors also wish to thank Davide Barbieri for his valuable contribution to the experimental evaluation.Decker, H.; Martinenghi, D. (2011). Inconsistency-Tolerant Integrity Checking. IEEE Transactions on Knowledge and Data Engineering. 23(2):218-234. https://doi.org/10.1109/TKDE.2010.87S21823423

    Inconsistency-tolerant business rules in distributed information systems

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    The final publication is available at Springer via http://10.1007/978-3-642-41033-8_41Business rules enhance the integrity of information systems. However, their maintenance does not scale up easily to distributed systems with concurrent transactions. To a large extent, that is due to two problematic exigencies: the postulates of total and isolated business rule satisfaction. For overcoming these problems, we outline a measure-based inconsistency-tolerant approach to business rules maintenance.Supported by ERDF/FEDER and MEC grants TIN2009-14460-C03, TIN2010-17139, TIN2012-37719-C03-01.Decker, H.; Muñoz Escoí, FD. (2013). Inconsistency-tolerant business rules in distributed information systems. En On the Move to Meaningful Internet Systems: OTM 2013 Workshops. Springer Verlag (Germany). 8186:322-331. https://doi.org/10.1007/978-3-642-41033-8_41S3223318186Abiteboul, S., Hull, R., Vianu, V.: Foundations of Databases. Addison-Wesley (1995)Berenson, H., Bernstein, P., Gray, J., Melton, J., O’Neil, E., O’Neil, P.: A critique of ANSI SQL isolation levels. In: Proc. SIGMOD 1995, pp. 1–10. ACM Press (1995)Bernstein, P., Hadzilacos, V., Goodman, N.: Concurrency Control and Recovery in Database Systems. Addison-Wesley (1987)Butleris, R., Kapocius, K.: The Business Rules Repository for Information Systems Design. In: Proc. 6th ADBIS, vol. 2, pp. 64–77. Slovak Univ. of Technology, Bratislava (2002)Davis, C.T.: Data Processing sphere of control. IBM Systems Journal 17(2), 179–198 (1978)Decker, H.: Partial Repairs that Tolerante Inconsistency. In: Eder, J., Bielikova, M., Tjoa, A.M. (eds.) ADBIS 2011. LNCS, vol. 6909, pp. 389–400. Springer, Heidelberg (2011)Decker, H.: Causes of the violation of integrity constraints for supporting the quality of databases. In: Murgante, B., Gervasi, O., Iglesias, A., Taniar, D., Apduhan, B.O. (eds.) ICCSA 2011, Part V. LNCS, vol. 6786, pp. 283–292. Springer, Heidelberg (2011)Decker, H.: New measures for maintaining the quality of databases. In: Murgante, B., Gervasi, O., Misra, S., Nedjah, N., Rocha, A.M.A.C., Taniar, D., Apduhan, B.O. (eds.) ICCSA 2012, Part IV. LNCS, vol. 7336, pp. 170–185. Springer, Heidelberg (2012)Decker, H.: Controlling the Consistency of the Evolution of Database Systems. In: Proc. 24th ICSSEA, Paris (2012)Decker, H., Martinenghi, D.: Inconsistency-tolerant Integrity Checking. IEEE Transactions on Knowledge and Data Engineering 23(2), 218–234 (2011)Decker, H., Muñoz-Escoí, F.D.: Revisiting and Improving a Result on Integrity Preservation by Concurrent Transactions. In: Meersman, R., Dillon, T., Herrero, P. (eds.) OTM 2010 Workshops. LNCS, vol. 6428, pp. 297–306. Springer, Heidelberg (2010)Eswaran, K., Gray, J., Lorie, R., Traiger, I.: The Notions of Consistency and Predicate Locks in a Database System. CACM 19(11), 624–633 (1976)Gilbert, S., Lynch, N.: Brewer’s Conjecture and the feasibility of Consistent, Available, Partition-tolerant Web Services. ACM SIGACT News 33(2), 51–59 (2002)Ibrahim, H.: Checking Integrity Constraints - How it Differs in Centralized, Distributed and Parallel Databases. In: Proc. 17th DEXA Workshops, pp. 563–568. IEEE (2006)Lynch, N., Blaustein, B., Siegel, M.: Correctness Conditions for Highly Available Replicated Databases. In: Proc. 5th PODC, pp. 11–28. ACM Press (1986)Martinenghi, D., Christiansen, H.: Transaction Management with Integrity Checking. In: Andersen, K.V., Debenham, J., Wagner, R. (eds.) DEXA 2005. LNCS, vol. 3588, pp. 606–615. Springer, Heidelberg (2005)Christiansen, H., Decker, H.: Integrity checking and maintenance in relational and deductive databases and beyond. In: Ma, Z. (ed.) Intelligent Databases: Technologies and Applications, pp. 238–285. Idea Group (2006)Morgan, T.: Business Rules and Information Systems - Aligning IT with Business Goals. Addison-Wesley (2002)Muñoz-Escoí, F.D., Ruiz-Fuertes, M.I., Decker, H., Armendáriz-Íñigo, J.E., de Mendívil, J.R.G.: Extending Middleware Protocols for Database Replication with Integrity Support. In: Meersman, R., Tari, Z. (eds.) OTM 2008, Part I. LNCS, vol. 5331, pp. 607–624. Springer, Heidelberg (2008)Nicolas, J.-M.: Logic for improving integrity checking in relational data bases. Acta Informatica 18, 227–253 (1982)Novakovic, I., Deletic, V.: Structuring of Business Rules in Information System Design and Architecture. Facta Universitatis Nis, Ser. Elec. Energ. 22(3), 305–312 (2009)Pipino, L., Lee, Y., Yang, R.: Data Quality Assessment. CACM 45(4), 211–218 (2002)Stonebraker, M.: Errors in Database Systems, Eventual Consistency, and the CAP Theorem (2010), http://cacm.acm.org/blog/blog-cacm/83396-errors-in-database-systems-eventual-consistency-and-the-cap-theoremStonebraker, M.: In search of database consistency. CACM 53(10), 8–9 (2010)Stonebraker, M.: Technical perspective - One size fits all: an idea whose time has come and gone. Commun. ACM 51(12), 76 (2008)Taveter, K.: Business Rules’ Approach to the Modelling, Design and Implementation of Agent-Oriented Information Systems. In: Proc. CAiSE workshop AOIS, Heidelberg (1999)Vidyasankar, K.: Serializability. In: Liu, L., Özu, T. (eds.) Encyclopedia of Database Systems, pp. 2626–2632. Springer (2009)Weikum, G., Vossen, G.: Transactional Information Systems. Morgan Kaufmann (2002)Vogels, W.: Eventually Consistent. ACM Queue 6(6), 14–19 (2008)Pereira Ziwich, P., Procpio Duarte, E., Pessoa Albini, L.: Distributed Integrity Checking for Systems with Replicated Data. In: Proc. ICPADS, vol. 1, pp. 363–369. IEEE CSP (2005

    Capturing and Scaling Up Concurrent Transactions in Uncertain Databases

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-42017-7_6[EN] This chapter provides a framework for capturing and scaling up concurrent transactions in uncertain databases. Models and methods proposed in the context of this framework for managing data uncertainty are innovative as previous studies have not considered the specific case of concurrent transactions, which may worsen the uncertainty of database management activities beyond the simplest case of isolated transactions. Indeed, as this chapter demonstrates, inconsistency tolerance of integrity management, constraint checking and repairing easily scale up to concurrent transactions in a natural way, and query answers in concurrent transactions over uncertain data remain certain in the presence of uncertainty. This analytical contribution is enriched by means of a reference architecture for uncertain database management under concurrent transactions that strictly adheres to models and methods that are the main contributions of this research.The second and the third author have been supported by FEDER and the Spanish grants TIN2009-14460-C03, TIN2010-17139.Cuzzocrea, A.; Decker, H.; Muñoz-Escoí, FD. (2013). Capturing and Scaling Up Concurrent Transactions in Uncertain Databases. Communications in Computer and Information Science. 246:70-85. https://doi.org/10.1007/978-3-642-42017-7_6S708524

    Numerical Simulation Approach for a Dynamically Operated Sorption-Enhanced Water-Gas Shift Reactor

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    A dynamically operated sorption-enhanced water–gas shift reactor is modelled to leverage its performance by means of model-based process design. This reactor shall provide CO₂-free synthesis gas for e-fuel production from pure CO. The nonlinear model equations describing simultaneous adsorption and reaction are solved with three numerical approaches in MATLAB: a built-in solver for partial differential equations, a semi-discretization method in combination with an ordinary differential equation solver, and an advanced graphic implementation of the latter method in Simulink. The novel implementation in Simulink offers various advantages for dynamic simulations and is expanded to a process model with six reaction chambers. The continuous conditions in the reaction chambers and the discrete states of the valves, which enable switching between reactive adsorption and regeneration, lead to a hybrid system. Controlling the discrete states in a finite-state machine in Stateflow enables automated switching between reactive adsorption and regeneration depending on predefined conditions, such as a time span or a concentration threshold in the product gas. The established chemical reactor simulation approach features unique possibilities in terms of simulation-driven development of operating procedures for intensified reactor operation. In a base case simulation, the sorbent usage for serial operation with adjusted switching times is increased by almost 15%

    Scalable Uncertainty-tolerant Business Rules

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-07617-1_16Business rules are of key importance for maintaining the correctness of business processes and the reliability of business data. When they take the form of integrity constraints, business rules also can help to contain the amount of uncertainty associated to business data and decisions based on those data. However, business rule enforcement may not scale up easily to systems with concurrent transactions. To a large extent, the problem is due to two common exigencies: the postulates of total and of isolated business rule satisfaction. In order to limit the accumulation of business rule violations, and thus of uncertainty, we are going to outline how a measure-based uncertainty-tolerant approach to business rules maintenance scales up to concurrent transactions. The scale-up is achieved by refraining from the postulates of total and isolated business rule satisfaction.Supported by ERDF/FEDER and the MEC grant TIN2012-37719-C03-01.Cuzzocrea, A.; Decker, H.; Muñoz-Escoí, FD. (2014). Scalable Uncertainty-tolerant Business Rules. En Hybrid Artificial Intelligence Systems: 9th International Conference, HAIS 2014, Salamanca, Spain, June 11-13, 2014. Proceedings. Springer Verlag (Germany). 179-190. https://doi.org/10.1007/978-3-319-07617-1_16S179190Abiteboul, S., Hull, R., Vianu, V.: Foundations of Databases. Addison-Wesley (1995)Abraham, A.: Hybrid approaches for approximate reasoning. Journal of Intelligent and Fuzzy Systems 23(2-3), 41–42 (2012)Bayer, R.: Integrity, concurrency, and recovery in databases. In: Samelson, K. (ed.) ECI 1976. LNCS, vol. 44, pp. 79–106. Springer, Heidelberg (1976)Berenson, H., Bernstein, P.A., Gray, J., Melton, J., O’Neil, E.J., O’Neil, P.E.: A critique of ansi sql isolation levels. In: SIGMOD Conference, pp. 1–10 (1995)Bernstein, P.A., Hadzilacos, V., Goodman, N.: Concurrency Control and Recovery in Database Systems. Addison-Wesley (1987)Cuzzocrea, A.: Optimization issues of querying and evolving sensor and stream databases. Information Systems 39, 196–198 (2014)Cuzzocrea, A., Leung, C.K.-S., Tanbeer, S.K.: Mining of Diverse Social Entities from Linked Data. In: Selçuk Candan, K., Amer-Yahia, S., Schweikardt, N., Christophides, V., Leroy, V. (eds.) Proc. Workshops of the EDBT/ICDT 2014 Joint Conference. CEUR Workshop Proceedings, pp. 269–274 (2014)Cuzzocrea, A., de Juan Marín, R., Decker, H., Muñoz-Escoí, F.D.: Managing uncertainty in databases and scaling it up to concurrent transactions. In: Hüllermeier, E., Link, S., Fober, T., Seeger, B. (eds.) SUM 2012. LNCS, vol. 7520, pp. 30–43. Springer, Heidelberg (2012)Date, C.J.: What not how: the business rules approach to application development. Addison-Wesley Longman Publishing Co., Inc., Boston (2000)Decan, A., Pijcke, F., Wijsen, J.: Certain conjunctive query answering in SQL. In: Hüllermeier, E., Link, S., Fober, T., Seeger, B. (eds.) SUM 2012. LNCS, vol. 7520, pp. 154–167. Springer, Heidelberg (2012)Decker, H.: Causes for inconsistency-tolerant schema update management. In: ICDE Workshops, pp. 157–161 (2011)Decker, H.: Causes of the violation of integrity constraints for supporting the quality of databases. In: Murgante, B., Gervasi, O., Iglesias, A., Taniar, D., Apduhan, B.O. (eds.) ICCSA 2011, Part V. LNCS, vol. 6786, pp. 283–292. Springer, Heidelberg (2011)Decker, H.: Partial repairs that tolerate inconsistency. In: Eder, J., Bielikova, M., Tjoa, A.M. (eds.) ADBIS 2011. LNCS, vol. 6909, pp. 389–400. Springer, Heidelberg (2011)Decker, H.: Answers that have quality. In: Murgante, B., Misra, S., Carlini, M., Torre, C.M., Nguyen, H.-Q., Taniar, D., Apduhan, B.O., Gervasi, O. (eds.) ICCSA 2013, Part II. LNCS, vol. 7972, pp. 543–558. Springer, Heidelberg (2013)Decker, H., Martinenghi, D.: Inconsistency-tolerant integrity checking. IEEE Trans. Knowl. Data Eng. 23(2), 218–234 (2011)Decker, H., Muñoz-Escoí, F.D.: Revisiting and improving a result on integrity preservation by concurrent transactions. In: Meersman, R., Dillon, T., Herrero, P. (eds.) OTM 2010. LNCS, vol. 6428, pp. 297–306. Springer, Heidelberg (2010)Eswaran, K.P., Chamberlin, D.D.: Functional specifications of subsystem for database integrity. In: Kerr, D.S. (ed.) Proceedings of the International Conference on Very Large Data Bases, Framingham, Massachusetts, USA, September 22-24, pp. 48–68. ACM (1975)Eswaran, K.P., Gray, J., Lorie, R.A., Traiger, I.L.: The notions of consistency and predicate locks in a database system. Commun. ACM 19(11), 624–633 (1976)Gardarin, G.: Integrity, consistency, concurrency, reliability in distributed database management systems. 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In: DEXA Workshops, pp. 563–568 (2006)Lynch, N.A., Blaustein, B.T., Siegel, M.: Correctness conditions for highly available replicated databases. In: PODC, pp. 11–28 (1986)Martinenghi, D., Christiansen, H., Decker, H.: Integrity checking and maintenance in relational and deductive databases and beyond. In: Ma, Z. (ed.) Intelligent Databases: Technologies and Applications, pp. 238–285. Idea Group Publishing (2006)Morgan, T.: Business Rules and Information Systems: Aligning IT with Business Goals (Unisys Series). Addison-Wesley Professional (2002)Muñoz-Escoí, F.D., Ruiz-Fuertes, M.I., Decker, H., Armendáriz-Íñigo, J.E., de Mendívil, J.R.G.: Extending middleware protocols for database replication with integrity support. In: Meersman, R., Tari, Z. (eds.) OTM 2008, Part I. LNCS, vol. 5331, pp. 607–624. Springer, Heidelberg (2008)Nicolas, J.-M.: Logic for improving integrity checking in relational data bases. 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    Recovery Protocols for Replicated Databases--A Survey

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    The main goal of replication is to increase dependabil-ity. Recovery protocols are a critical building block for re-alizing this goal. In this survey, we present an analysis of recovery protocols proposed in recent years. In particu-lar, we relate these protocols to the replication protocols that use them, and discuss their main advantages and dis-advantages. We classify replication and recovery protocols by several characteristics and point out interrelationships between them

    Complex matching of RDF datatype properties

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    Property mapping is a fundamental component of ontology matching, and yet there is little support that goes beyond the identification of single property matches. Real data often requires some degree of composition, trivially exemplified by the mapping of "first name" and "last name" to "full name" on one end, to complex matchings, such as parsing and pairing symbol/digit strings to SSN numbers, at the other end of the spectrum. In this paper, we propose a two-phase instance-based technique for complex datatype property matching. Phase 1 computes the Estimate Mutual Information matrix of the property values to (1) find simple, 1:1 matches, and (2) compute a list of possible complex matches. Phase 2 applies Genetic Programming to the much reduced search space of candidate matches to find complex matches. We conclude with experimental results that illustrate how the technique works. Furthermore, we show that the proposed technique greatly improves results over those obtained if the Estimate Mutual Information matrix or the Genetic Programming techniques were to be used independently. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-40285-2_18
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