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Pedro Alípio

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Paulo Roberto de Carvalho

Universidade Federal do Amazonas

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University of Ljubljana

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University of Patras

BORDEAUX INP

George Kormentzas

Júlio César Royer

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Papers by Pedro Alípio

An ontology for network services

Most of the network service specifications use XML based models. However, as XML imposes a hierar... more Most of the network service specifications use XML based models. However, as XML imposes a hierarchical structure, several types of relations may not be modeled. Therefore, richer specification languages are required in order to specify all network services vocabulary and how it relates with management tasks and with network configuration. This paper presents an ontology based model for network services, overcoming those semantic gaps and creating a better ground for reasoning over services fostering their self-configuration.

An Ontology for Network Services

Springer eBooks, 2006

Most of the network service specifications use XML based models. However, as XML imposes a hierar... more Most of the network service specifications use XML based models. However, as XML imposes a hierarchical structure, several types of relations may not be modeled. Therefore, richer specification languages are required in order to specify all network services vocabulary and how it relates with management tasks and with network configuration. This paper presents an ontology based model for network services, overcoming those semantic gaps and creating a better ground for reasoning over services fostering their self-configuration.

Automatic Detection of SLS Violation Using Knowledge based Systems

Abstract. Self-Management of multiservice network domains must include automatic detection of ser... more Abstract. Self-Management of multiservice network domains must include automatic detection of service quality violations in order to perform appropriate and timely responses, fostering the fulfillment of the service agreements committed with cus-tomers, or other ISPs. As knowledge based systems are capable of emulating human knowledge, they are presented here as convenient tools to specify heuristics for QoS violation detection. In this paper, the implementation of a service violation detection agent is described and an illustrative scenario of its use is also presented.

A Logic-based Approach for IP Network Services Management and Configuration

— Most of the network service management systems rely on informal specifications, hard-coded prog... more — Most of the network service management systems rely on informal specifications, hard-coded programming and relational databases to store and manage network services. As a result, such systems may not be correct facing their requirements and they may not be flexible enough to perform network service management efficiently. This paper presents ongoing work toward an innovative approach, based on knowledge representation, to formally specify the contractual, administrative and technical contents of Service Level Agreements, and the network service management processes and their orchestration promoting network service autonomic management and configuration. By using a knowledge based formal framework and an inference engine capable of reasoning over concepts, relations and changes of state, it is possible to create a more flexible and robust ground for specifying and implementing autonomic and adaptive management tasks. I.

An Ontology for Network Services

Abstract. Most of the network service specifications are implemented using relational databases o... more Abstract. Most of the network service specifications are implemented using relational databases or XML schemas. However, those specifications are not flexible and expressive enough to be extended with new service classes, different corporate policies, network configurations and deployment strategies; thus, most of the QoS management operations are implemented as hard-coded software components. This paper presents a novel approach in the specification of IP network services, using F-logic knowledge representation framework, aiming to include, in the same specification, the high-level service requirements, the network model and the necessary operations for the deployment of multiple network services.

Automatic Detection of SLS Violation Using Knowledge Based Systems

Self-Management of multiservice network domains must include automatic detection of service quali... more Self-Management of multiservice network domains must include automatic detection of service quality violations in order to perform appropriate and timely responses, fostering the fulfillment of the service agreements committed with customers, or other ISPs. As knowledge based systems are capable of emulating human knowledge, they are presented here as convenient tools to specify heuristics for QoS violation detection. In this paper, the implementation of a service violation detection agent is described and an illustrative scenario of its use is also presented.

A Logic-based Approach for IP Network Services Management and Configuration

Most of the network service management systems rely on informal specifications, hard-coded progra... more Most of the network service management systems rely on informal specifications, hard-coded programming and relational databases to store and manage network services. As a result, such systems may not be correct facing their requirements and they may not be flexible enough to perform network service management efficiently. This paper presents ongoing work toward an innovative approach, based on knowledge representation, to formally specify the contractual, administrative and technical contents of Service Level Agreements, and the network service management processes and their orchestration promoting network service autonomic management and configuration. By using a knowledge based formal framework and an inference engine capable of reasoning over concepts, relations and changes of state, it is possible to create a more flexible and robust ground for specifying and implementing autonomic and adaptive management tasks.

A unified metric for quality of service quantification

Internet service providers usually express the quality of network services through a set of value... more Internet service providers usually express the quality of network services through a set of values determined according to several network performance parameters periodically collected or measured. However, for common end-users, these values do not give an overall idea of the quality of the network services as they stand for different units and evaluate different perspectives of each service quality. In this context, this paper proposes the definition of a serviceoriented unified metric which quantifies a global Quality of Service (QoS) indication by processing standard QoS parameters through a fuzzy controller. The proposed methodology, based on fuzzy logic and tested on Xfuzzy 3.0 platform, allows to close the gap between a high-level QoS perspective and the effective QoS measurements at lower protocolar levels. The definition of a single per-service QoS metric can be useful to simplify control tasks such as QoS routing, SLA negotiation and auditing.

Using CLIPS to Detect Network Intrusions

This paper shows how to build a network intrusion detection system by slightly modifying NASA’s C... more This paper shows how to build a network intrusion detection system by slightly modifying NASA’s CLIPS source code, introducing features such as single and multiple string pattern matching, certainty factors and time-stamp operators. Several Snort functions and plugins were adapted and used for packet decoding and preprocessing to provide the basic requirements for such a system. The integration of CLIPS and Snort features allows the specification of complex stateful network intrusion detection heuristics which can model abstract attack scenarios. The results show that CLIPS can be useful to follow and correlate intruder activities by monitoring network traffic.

An Ontology for Network Services

Computing and Informatics / Computers and Artificial Intelligence, 2006

Most of the network service specifications use XML based models. However, as XML imposes a hierar... more Most of the network service specifications use XML based models. However, as XML imposes a hierarchical structure, several types of relations may not be modeled. Therefore, richer specification languages are required in order to specify all network services vocabulary and how it relates with management tasks and with network configuration. This paper presents an ontology based model for network services,

Influence of the region of origin on the mycobiota of grapes with emphasis on Aspergillus and Penicillium species

Mycological Research, 2006

A three-year study was undertaken to investigate the fungal species present on the surface of gra... more A three-year study was undertaken to investigate the fungal species present on the surface of grape berries from Portuguese vineyards in four winemaking regions. Emphasis was given to Aspergillus and Penicillium species due to their relevance for mycotoxin production. From the 3517 fungal strains detected 27 genera were identified. The region of origin markedly influenced the spoilage fungal population to which berries are exposed. The main differences found were in the incidence of A. niger aggregate, Botryis cinerea and Penicillium species (P. brevicompactum, P. citrinum, P. glabrum/spinulosum, P. expansum, P. implicatum and P. thomii). In more humid climates, Botrytis seems to be the main pathogen and spoiling agent, and the incidence of black Aspergillus is minimal. The most important mycotoxin-producing species found was A. carbonarius, which is an ochratoxin A producer. The present study provides a detailed description of the fungi found on the berry surface of Portuguese grapes and shows the Aspergillus and Penicillium species, which vary significantly by geographic origin. This is of crucial importance to understand fungal hazards for grapes and wine and to the knowledge of field ecology of the species.

XML Service Level Specification and Validation

This paper addresses the problem of formalizing Service Level Specifications (SLSs) as a first st... more This paper addresses the problem of formalizing Service Level Specifications (SLSs) as a first step to simplify and automate the configuration and management of multiservice IP networks. A formal representation of SLSs will allow their automatic validation and processing, fostering the dynamic negotiation of SLSs and the interoperability among service management entities. In this way, taking advantage of XML extensibility and portability, a Schema is presented describing XML SLSs sections and their contents. In addition, an XML validator tool was built to check if SLSs are correctly specified. An XML SLS for an IP telephony service is used to exemplify this proposal expressiveness.

An ontology for network services

Most of the network service specifications use XML based models. However, as XML imposes a hierar... more Most of the network service specifications use XML based models. However, as XML imposes a hierarchical structure, several types of relations may not be modeled. Therefore, richer specification languages are required in order to specify all network services vocabulary and how it relates with management tasks and with network configuration. This paper presents an ontology based model for network services, overcoming those semantic gaps and creating a better ground for reasoning over services fostering their self-configuration.

An Ontology for Network Services

Springer eBooks, 2006

Most of the network service specifications use XML based models. However, as XML imposes a hierar... more Most of the network service specifications use XML based models. However, as XML imposes a hierarchical structure, several types of relations may not be modeled. Therefore, richer specification languages are required in order to specify all network services vocabulary and how it relates with management tasks and with network configuration. This paper presents an ontology based model for network services, overcoming those semantic gaps and creating a better ground for reasoning over services fostering their self-configuration.

Automatic Detection of SLS Violation Using Knowledge based Systems

Abstract. Self-Management of multiservice network domains must include automatic detection of ser... more Abstract. Self-Management of multiservice network domains must include automatic detection of service quality violations in order to perform appropriate and timely responses, fostering the fulfillment of the service agreements committed with cus-tomers, or other ISPs. As knowledge based systems are capable of emulating human knowledge, they are presented here as convenient tools to specify heuristics for QoS violation detection. In this paper, the implementation of a service violation detection agent is described and an illustrative scenario of its use is also presented.

A Logic-based Approach for IP Network Services Management and Configuration

— Most of the network service management systems rely on informal specifications, hard-coded prog... more — Most of the network service management systems rely on informal specifications, hard-coded programming and relational databases to store and manage network services. As a result, such systems may not be correct facing their requirements and they may not be flexible enough to perform network service management efficiently. This paper presents ongoing work toward an innovative approach, based on knowledge representation, to formally specify the contractual, administrative and technical contents of Service Level Agreements, and the network service management processes and their orchestration promoting network service autonomic management and configuration. By using a knowledge based formal framework and an inference engine capable of reasoning over concepts, relations and changes of state, it is possible to create a more flexible and robust ground for specifying and implementing autonomic and adaptive management tasks. I.

An Ontology for Network Services

Abstract. Most of the network service specifications are implemented using relational databases o... more Abstract. Most of the network service specifications are implemented using relational databases or XML schemas. However, those specifications are not flexible and expressive enough to be extended with new service classes, different corporate policies, network configurations and deployment strategies; thus, most of the QoS management operations are implemented as hard-coded software components. This paper presents a novel approach in the specification of IP network services, using F-logic knowledge representation framework, aiming to include, in the same specification, the high-level service requirements, the network model and the necessary operations for the deployment of multiple network services.

Automatic Detection of SLS Violation Using Knowledge Based Systems

Self-Management of multiservice network domains must include automatic detection of service quali... more Self-Management of multiservice network domains must include automatic detection of service quality violations in order to perform appropriate and timely responses, fostering the fulfillment of the service agreements committed with customers, or other ISPs. As knowledge based systems are capable of emulating human knowledge, they are presented here as convenient tools to specify heuristics for QoS violation detection. In this paper, the implementation of a service violation detection agent is described and an illustrative scenario of its use is also presented.

A Logic-based Approach for IP Network Services Management and Configuration

Most of the network service management systems rely on informal specifications, hard-coded progra... more Most of the network service management systems rely on informal specifications, hard-coded programming and relational databases to store and manage network services. As a result, such systems may not be correct facing their requirements and they may not be flexible enough to perform network service management efficiently. This paper presents ongoing work toward an innovative approach, based on knowledge representation, to formally specify the contractual, administrative and technical contents of Service Level Agreements, and the network service management processes and their orchestration promoting network service autonomic management and configuration. By using a knowledge based formal framework and an inference engine capable of reasoning over concepts, relations and changes of state, it is possible to create a more flexible and robust ground for specifying and implementing autonomic and adaptive management tasks.

A unified metric for quality of service quantification

Internet service providers usually express the quality of network services through a set of value... more Internet service providers usually express the quality of network services through a set of values determined according to several network performance parameters periodically collected or measured. However, for common end-users, these values do not give an overall idea of the quality of the network services as they stand for different units and evaluate different perspectives of each service quality. In this context, this paper proposes the definition of a serviceoriented unified metric which quantifies a global Quality of Service (QoS) indication by processing standard QoS parameters through a fuzzy controller. The proposed methodology, based on fuzzy logic and tested on Xfuzzy 3.0 platform, allows to close the gap between a high-level QoS perspective and the effective QoS measurements at lower protocolar levels. The definition of a single per-service QoS metric can be useful to simplify control tasks such as QoS routing, SLA negotiation and auditing.

Using CLIPS to Detect Network Intrusions

This paper shows how to build a network intrusion detection system by slightly modifying NASA’s C... more This paper shows how to build a network intrusion detection system by slightly modifying NASA’s CLIPS source code, introducing features such as single and multiple string pattern matching, certainty factors and time-stamp operators. Several Snort functions and plugins were adapted and used for packet decoding and preprocessing to provide the basic requirements for such a system. The integration of CLIPS and Snort features allows the specification of complex stateful network intrusion detection heuristics which can model abstract attack scenarios. The results show that CLIPS can be useful to follow and correlate intruder activities by monitoring network traffic.

An Ontology for Network Services

Computing and Informatics / Computers and Artificial Intelligence, 2006

Most of the network service specifications use XML based models. However, as XML imposes a hierar... more Most of the network service specifications use XML based models. However, as XML imposes a hierarchical structure, several types of relations may not be modeled. Therefore, richer specification languages are required in order to specify all network services vocabulary and how it relates with management tasks and with network configuration. This paper presents an ontology based model for network services,

Influence of the region of origin on the mycobiota of grapes with emphasis on Aspergillus and Penicillium species

Mycological Research, 2006

A three-year study was undertaken to investigate the fungal species present on the surface of gra... more A three-year study was undertaken to investigate the fungal species present on the surface of grape berries from Portuguese vineyards in four winemaking regions. Emphasis was given to Aspergillus and Penicillium species due to their relevance for mycotoxin production. From the 3517 fungal strains detected 27 genera were identified. The region of origin markedly influenced the spoilage fungal population to which berries are exposed. The main differences found were in the incidence of A. niger aggregate, Botryis cinerea and Penicillium species (P. brevicompactum, P. citrinum, P. glabrum/spinulosum, P. expansum, P. implicatum and P. thomii). In more humid climates, Botrytis seems to be the main pathogen and spoiling agent, and the incidence of black Aspergillus is minimal. The most important mycotoxin-producing species found was A. carbonarius, which is an ochratoxin A producer. The present study provides a detailed description of the fungi found on the berry surface of Portuguese grapes and shows the Aspergillus and Penicillium species, which vary significantly by geographic origin. This is of crucial importance to understand fungal hazards for grapes and wine and to the knowledge of field ecology of the species.

XML Service Level Specification and Validation

This paper addresses the problem of formalizing Service Level Specifications (SLSs) as a first st... more This paper addresses the problem of formalizing Service Level Specifications (SLSs) as a first step to simplify and automate the configuration and management of multiservice IP networks. A formal representation of SLSs will allow their automatic validation and processing, fostering the dynamic negotiation of SLSs and the interoperability among service management entities. In this way, taking advantage of XML extensibility and portability, a Schema is presented describing XML SLSs sections and their contents. In addition, an XML validator tool was built to check if SLSs are correctly specified. An XML SLS for an IP telephony service is used to exemplify this proposal expressiveness.