In this paper, the values of received signal strength indicator (RSSI) are studied for various deployment environments in wireless sensor networks. The accurate RSSI estimation can improve the accuracy of several algorithms used in localization, mobility, and routing. The experiments are conducted to investigate the variation in RSSI values with respect to: a) distance between transmitter and receiver, b) non-circular radio communication, and c) alignment of transmitter and receiver. The results show that because of a non-circular radio communication model and proper alignment techniques, the overall energy consumption of a sensor network can be reduced by 43%.
{"title":"Using Received Signal Strength Variation for Energy Efficient Data Dissemination in Wireless Sensor Networks","authors":"S. Erdogan, S. Hussain","doi":"10.1109/DEXA.2007.70","DOIUrl":"https://doi.org/10.1109/DEXA.2007.70","url":null,"abstract":"In this paper, the values of received signal strength indicator (RSSI) are studied for various deployment environments in wireless sensor networks. The accurate RSSI estimation can improve the accuracy of several algorithms used in localization, mobility, and routing. The experiments are conducted to investigate the variation in RSSI values with respect to: a) distance between transmitter and receiver, b) non-circular radio communication, and c) alignment of transmitter and receiver. The results show that because of a non-circular radio communication model and proper alignment techniques, the overall energy consumption of a sensor network can be reduced by 43%.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121957040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The growing use of radio frequency identification (RFID) technology to enhance ubiquitous computing environments has only begun to be realized. It allows for the identification of objects and/or subjects remotely using attached RFID tags via a radio frequency channel, hence identification is achieved in a contactless manner. This paper presents issues concerning security and privacy of RFID systems which are heavily discussed in public and introduces authentication protocol for a RFID security protocol which serves as a proof of concept for authentication an RFID tag to a reader device using the vernam and standard encryption as a cryptographic primitive. To verify our protocol, we use model checking methodology, that is, Casper (a compiler for security protocol), CSP (communicating sequential processes) and then verify security properties such as secrecy and authentication using FDR (failure divergence refinement) tool.
{"title":"The Design and Verification of RFID Authentication Protocol for Ubiquitous Computing","authors":"Hyun Seok Kim, Jin-Young Choi","doi":"10.1109/DEXA.2007.6","DOIUrl":"https://doi.org/10.1109/DEXA.2007.6","url":null,"abstract":"The growing use of radio frequency identification (RFID) technology to enhance ubiquitous computing environments has only begun to be realized. It allows for the identification of objects and/or subjects remotely using attached RFID tags via a radio frequency channel, hence identification is achieved in a contactless manner. This paper presents issues concerning security and privacy of RFID systems which are heavily discussed in public and introduces authentication protocol for a RFID security protocol which serves as a proof of concept for authentication an RFID tag to a reader device using the vernam and standard encryption as a cryptographic primitive. To verify our protocol, we use model checking methodology, that is, Casper (a compiler for security protocol), CSP (communicating sequential processes) and then verify security properties such as secrecy and authentication using FDR (failure divergence refinement) tool.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116588888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Archiving, organizing, and searching multimedia data in an appropriate fashion is a task of increasing importance. The ontology theory may be appropriately extended in order to face this challenging issue. In this paper we propose an extension of an Image Database model based on NF2 with an Ontology model. We first describe NF2 and the main concepts of Image Ontologies, then we propose a general architecture for supporting creation and management of multimedia objects.
{"title":"Towards a definition of an Image Ontology","authors":"Antonio Penta, A. Picariello, L. Tanca","doi":"10.1109/DEXA.2007.83","DOIUrl":"https://doi.org/10.1109/DEXA.2007.83","url":null,"abstract":"Archiving, organizing, and searching multimedia data in an appropriate fashion is a task of increasing importance. The ontology theory may be appropriately extended in order to face this challenging issue. In this paper we propose an extension of an Image Database model based on NF2 with an Ontology model. We first describe NF2 and the main concepts of Image Ontologies, then we propose a general architecture for supporting creation and management of multimedia objects.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121515987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mildrey Carbonell Castro, J. M. Sierra, J. Márquez, Antonio Izquierdo Manzanares
Most of the electronic payment proposals found in the scientific literature are focused on a traditional two-domain business model: customer and merchant. However, an enhanced payment model with an intermediary entity could be considered, with the goal of providing additional advantages for the parties in the e-commerce scenario. In this article, we will show the utility of intermediary inside the payment process describing a service of centralization of the payment system (different to a gateway, IIP or connection broker) in a multi-party payment scenario. We illustrate how this service improves Internet selling applications security, which currently need an effort for facing the weaknesses of the different payments models.
{"title":"Security analysis of a new multi-party payment protocol with intermediary service.","authors":"Mildrey Carbonell Castro, J. M. Sierra, J. Márquez, Antonio Izquierdo Manzanares","doi":"10.1109/DEXA.2007.130","DOIUrl":"https://doi.org/10.1109/DEXA.2007.130","url":null,"abstract":"Most of the electronic payment proposals found in the scientific literature are focused on a traditional two-domain business model: customer and merchant. However, an enhanced payment model with an intermediary entity could be considered, with the goal of providing additional advantages for the parties in the e-commerce scenario. In this article, we will show the utility of intermediary inside the payment process describing a service of centralization of the payment system (different to a gateway, IIP or connection broker) in a multi-party payment scenario. We illustrate how this service improves Internet selling applications security, which currently need an effort for facing the weaknesses of the different payments models.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122743372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper describes the ESIDE-Depian intrusion detection and prevention system, which uses Bayesian structural and parametric learning and also evidence propagation and adaptation, in order to improve the accuracy and manageability of network intrusion detection systems (NIDS). Current NIDS do not consider the two main detection paradigms, i.e. misuse detection and anomaly detection, in an unified style, so the analysis is not inherently complete. Besides, historical data are not generally used, neither for analysis nor for sequential adaptation of the knowledge representation models used for detection; hence this wealthy information about the essence and the potential trends of the target system is not commonly considered. Thus, by the generalized use of Bayesian belief networks, ESIDE-Depian achieves the main goal of detecting and preventing both well-known and also zero-day attacks with excellent results, by means of unified real-time analysis of network traffic.
{"title":"Intensive Use of Bayesian Belief Networks for the Unified, Flexible and Adaptable Analysis of Misuses and Anomalies in Network Intrusion Detection and Prevention Systems","authors":"P. G. Bringas","doi":"10.1109/DEXA.2007.38","DOIUrl":"https://doi.org/10.1109/DEXA.2007.38","url":null,"abstract":"This paper describes the ESIDE-Depian intrusion detection and prevention system, which uses Bayesian structural and parametric learning and also evidence propagation and adaptation, in order to improve the accuracy and manageability of network intrusion detection systems (NIDS). Current NIDS do not consider the two main detection paradigms, i.e. misuse detection and anomaly detection, in an unified style, so the analysis is not inherently complete. Besides, historical data are not generally used, neither for analysis nor for sequential adaptation of the knowledge representation models used for detection; hence this wealthy information about the essence and the potential trends of the target system is not commonly considered. Thus, by the generalized use of Bayesian belief networks, ESIDE-Depian achieves the main goal of detecting and preventing both well-known and also zero-day attacks with excellent results, by means of unified real-time analysis of network traffic.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130793623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. R. Luaces, J. Paramá, Oscar Pedreira, Diego Seco, J. Viqueira
Both geographic information systems and information retrieval have been very active research fields in the last decades. Lately, a new research field called geographic information retrieval has appeared from the intersection of these two fields. The main goal of this field is to define index structures and techniques to efficiently store and retrieve documents using both the text and the geographic references contained within the text. We present in this paper the architecture of a system for geographic information retrieval. It defines a workflow for the extraction of the geographic references in the document. In addition, a new index structure is defined that combines an inverted index, a spatial index, and an ontology. This structure improves the query capabilities of other proposals.
{"title":"An Index Structure To Retrieve Documents With Geographic Information","authors":"M. R. Luaces, J. Paramá, Oscar Pedreira, Diego Seco, J. Viqueira","doi":"10.1109/DEXA.2007.35","DOIUrl":"https://doi.org/10.1109/DEXA.2007.35","url":null,"abstract":"Both geographic information systems and information retrieval have been very active research fields in the last decades. Lately, a new research field called geographic information retrieval has appeared from the intersection of these two fields. The main goal of this field is to define index structures and techniques to efficiently store and retrieve documents using both the text and the geographic references contained within the text. We present in this paper the architecture of a system for geographic information retrieval. It defines a workflow for the extraction of the geographic references in the document. In addition, a new index structure is defined that combines an inverted index, a spatial index, and an ontology. This structure improves the query capabilities of other proposals.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130343176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose an approach to formalize the patterns and to automatically apply the formalized patterns. In our case, we use the pattern paradigm to refine security policies of a workflow. A policy refinement process derives low- level workflow policies from high-level and abstract policies specified by stakeholders. Such refinement process requires domain-specific expertise knowledge, which will be captured by using the pattern paradigm. These refinement patterns are formalized by using both description logic and temporal logic formalisms.
{"title":"Using patterns paradigm to refine workflow policies","authors":"T. Rochaeli, C. Eckert","doi":"10.1109/DEXA.2007.63","DOIUrl":"https://doi.org/10.1109/DEXA.2007.63","url":null,"abstract":"We propose an approach to formalize the patterns and to automatically apply the formalized patterns. In our case, we use the pattern paradigm to refine security policies of a workflow. A policy refinement process derives low- level workflow policies from high-level and abstract policies specified by stakeholders. Such refinement process requires domain-specific expertise knowledge, which will be captured by using the pattern paradigm. These refinement patterns are formalized by using both description logic and temporal logic formalisms.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127097221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dynamic taxonomies integrated into e-learning tools play a double role: on the one hand they are a powerful retrieval system in the usually large content base of an e-learning environment, on the other hand they allow and strongly encourage orthogonal visits of available learning resources by exploiting associations the user would not have thought of (and which are the specific contribution of dynamic taxonomies). These two roles are of interest both for teachers, who may use the search engine to retrieve hints for presentations, assignments, etc., and for students, who may explore the whole learning environment in a new profitable way, which makes, for example, immediately available for a same subject different aspects dealt with in different courses. In the paper we describe the integration of dynamic taxonomies into Moodle, a course management system for cooperative learning.
{"title":"E-learning: Coupling Course Management Systems and Dynamic Taxonomies","authors":"B. Demo, Alessio Angius","doi":"10.1109/DEXA.2007.89","DOIUrl":"https://doi.org/10.1109/DEXA.2007.89","url":null,"abstract":"Dynamic taxonomies integrated into e-learning tools play a double role: on the one hand they are a powerful retrieval system in the usually large content base of an e-learning environment, on the other hand they allow and strongly encourage orthogonal visits of available learning resources by exploiting associations the user would not have thought of (and which are the specific contribution of dynamic taxonomies). These two roles are of interest both for teachers, who may use the search engine to retrieve hints for presentations, assignments, etc., and for students, who may explore the whole learning environment in a new profitable way, which makes, for example, immediately available for a same subject different aspects dealt with in different courses. In the paper we describe the integration of dynamic taxonomies into Moodle, a course management system for cooperative learning.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134038475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The problem of efficiently evaluating XPath and XQuery queries has become increasingly significant since more and more XML data is stored in its native form. We propose a novel optimisation technique for XML queries that is based on the semantic properties exhibited by XML data. In sharp contrast to previous studies on selectivity estimation we propose to specify bounds on the number of element nodes in an XML tree that form the root of isomorphic subtrees. It turns out that efficient reasoning about these constraints provides effective means to predict the number of XPath and XQuery query answers, to predict the number of updates using the XQuery update facility, to predict the number of en(de)cryptions using XML encryption, and to optimise XML queries.
{"title":"XML Query Optimisation: Specify your Selectivity","authors":"Sven Hartmann, Sebastian Link","doi":"10.1109/DEXA.2007.19","DOIUrl":"https://doi.org/10.1109/DEXA.2007.19","url":null,"abstract":"The problem of efficiently evaluating XPath and XQuery queries has become increasingly significant since more and more XML data is stored in its native form. We propose a novel optimisation technique for XML queries that is based on the semantic properties exhibited by XML data. In sharp contrast to previous studies on selectivity estimation we propose to specify bounds on the number of element nodes in an XML tree that form the root of isomorphic subtrees. It turns out that efficient reasoning about these constraints provides effective means to predict the number of XPath and XQuery query answers, to predict the number of updates using the XQuery update facility, to predict the number of en(de)cryptions using XML encryption, and to optimise XML queries.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122492474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Brisaboa, Yolanda Cillero, A. Fariña, Susana Ladra, Oscar Pedreira
The development of applications that manage large text collections needs indexing methods which allow efficient retrieval over text. Several indexes have been proposed which try to reach a good trade-off between the space needed to store both the text and the index, and its search efficiency. Self-indexes are becoming more and more popular. Not only they index the text, but they keep enough information to recover any portion of it without the need of keeping it explicitly. Therefore, they actually replace the text. In this paper, we focus in a self-index known as wavelet tree. Being originally organized as a binary tree, it was designed to index the characters from a text. We present three variants of this method that aim at reducing its size, while keeping a good trade-off between space and performance, as well as making it well-suited for indexing natural language texts. The first approach we describe joins Huffman compression and wavelet trees. The other two new variants index words instead of characters and use two different word-based compressors.
{"title":"A New Approach for Document Indexing UsingWavelet Trees","authors":"N. Brisaboa, Yolanda Cillero, A. Fariña, Susana Ladra, Oscar Pedreira","doi":"10.1109/DEXA.2007.118","DOIUrl":"https://doi.org/10.1109/DEXA.2007.118","url":null,"abstract":"The development of applications that manage large text collections needs indexing methods which allow efficient retrieval over text. Several indexes have been proposed which try to reach a good trade-off between the space needed to store both the text and the index, and its search efficiency. Self-indexes are becoming more and more popular. Not only they index the text, but they keep enough information to recover any portion of it without the need of keeping it explicitly. Therefore, they actually replace the text. In this paper, we focus in a self-index known as wavelet tree. Being originally organized as a binary tree, it was designed to index the characters from a text. We present three variants of this method that aim at reducing its size, while keeping a good trade-off between space and performance, as well as making it well-suited for indexing natural language texts. The first approach we describe joins Huffman compression and wavelet trees. The other two new variants index words instead of characters and use two different word-based compressors.","PeriodicalId":314834,"journal":{"name":"18th International Workshop on Database and Expert Systems Applications (DEXA 2007)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122884166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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