PerLa Project Politecnico di Milano
PerLa Project
"Declarative language and middleware
for pervasive systems"
Papers
Here is the up to date list of the PerLa related publications:
 
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Context-aware Self Adapting Systems: a Ground for the Cooperation of Data, Software, and Services
Fabio A. Schreiber, Emanuele Panigati
International Journal of Next-Generation Computing
Vol. 8, No. 1, March 2017
 
Abstract: Modern technologies related to Pervasive and Ubiquitous computing require software to self adapt to different operating environments and situations, in a word, to different contexts. Several approaches have been proposed to solve this problem both in the Data Management and in the Programming Languages communities, however these efforts have proceeded along separate paths with little, if no interaction. We claim that there are complementary features which can bring different paradigms in the Data Management and Programming Languages domains to a fruitful cooperation in building Adaptive Systems. In fact, data collected by sensor networks can be directly used by application programs as well as used to determine the context the application is working in, so attaining a context-aware behavior obtained by triggering the execution of specific program modules or the connection to relevant web services. In this paper, we use the PerLa pervasive data management language and JCop Context-Oriented Programming Java language extension to show the feasibility of this approach applied to the classical case of keeping an office room climate comfortable under several environmental constraints and to the management of a ski resort.
 
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Data Management in Pervasive Systems
Colace, F., De Santo, M., Moscato, V., Picariello, A., Schreiber, F.A., Tanca, L. (Eds.)

Springer Cham, Heidelberg, (DOI 10.1007/978-3-319-20062-0), pp XXII+368, 2015
 
Abstract: This book contributes to illustrating the methodological and technological issues of data management in Pervasive Systems by using the DataBenc project as the running case study for a variety of research contributions: sensor data management, user-originated data operation and reasoning, multimedia data management, data analytics and reasoning for event detection and decision making, context modelling and control, automatic data and service tailoring for personalization and recommendation. The book is organized into the following main parts: i) multimedia information management; ii) sensor data streams and storage; iii) social networks as information sources; iv) context awareness and personalization. The case study is used throughout the book as a reference example.
 
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Sensors and Wireless Sensor Networks as Data Sources: Models and Languages
F. A. Schreiber, M. Roveri
Chapter 4 in F. Colace et Al.- Data Management in Pervasive Systems - Springer Cham, Heidelberg

 
Abstract: A complete pervasive application is composed of several architectural layers requiring different abilities, from low level hardware programming to the design of high level abstractions. Physical integration is achieved operating on low level layers, while spontaneous interoperability is mostly related to the highest levels. Moreover, merging modern pervasive system frameworks with the concept of context is a fundamental cornerstone that must achieved. The sensors of the network can be used to characterize and discover possible contexts, and for defining suitable actions accordingly. This chapter mainly focuses on the issues related to the heterogeneity of the different devices composing a WSN abstracted by means of conceptual models. This allows to query and send commands to the devices using a single database-style language. Examples will be shown using PerLa, a declarative SQL-like language and infrastructure for data management in pervasive systems, mainly oriented to monitoring applications, but, with its context management extension, also suitable as a support substratum for the deployment of autonomic systems.
 
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Data Streams and Data Stream Management Systems and Languages
E. Panigati, F. A. Schreiber, C. Zaniolo
Chapter 5 in F. Colace et Al.- Data Management in Pervasive Systems - Springer Cham, Heidelberg

 
Abstract: The massive usage of Data Streams dates back to the artificial satellites information processing systems and to their commercial applications exploitation in the early seventies, such as Telecommunications switching, Land Monitoring, Meteorological surveillance, etc.. Today they are extensively used also in monitoring systems applications based on wired and wireless sensor networks, in social networks and in the Internet of Things. The main functional goals of Data Stream Management Systems (DSMSs) are: \emph{(a)} results must be pushed to the output promptly and eagerly, while input tuples continue to arrive; \emph{(b)} because of the unbounded and massive nature of the data streams, all past tuples cannot be memorized for future uses. Only synopses can be kept in memory and the rest must be discarded. A key research issue for DSMSs is deciding which data model and query language should be used. A wide spectrum of different solutions have in fact been proposed, including operator-based graphical interfaces, programming language extensions, and an assortment of other solutions provided in publish/subscribe systems. In this chapter, the main features and architectural issues will be examined for DSMSs as an introduction to the following chapters, which detail their usage in different application areas.
 
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Pervasive Systems Architecture and the Main Related Technologies
F. Colace, M. De Santo, V. Moscato, A. Picariello, F. A. Schreiber, L. Tanca
Chapter 2 in F. Colace et Al.- Data Management in Pervasive Systems - Springer Cham, Heidelberg

 
Abstract: After introducing the main architectural issues concerning Pervasive Systems, this chapter deals with the essential technological aspects involved in their implementation and deployment. Being it focused on Data Management, we shall introduce the main problems and solutions related to Real-Time Data and the usage of Main-memory Database Management Systems. We will quickly review also some typical advanced data management topics that are useful prerequisites for the subsequent chapters: aspects of Big Data management, Linked Open Data, generalities of information integration including multimedia information management, issues related to the mobility of both users and information sources (e. g.: object tracking, dynamic environmental changes, etc.), the usage of social networks (Facebook, Twitter and others) as information sources and, last but not least, aspects related to the dependability of the system mainly focusing on security and privacy. The material in this chapter will be introductory and will make extensive reference to the existing literature on the different topics.
 
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Context-Aware Software Approaches: a Comparison and an Integration Proposal (discussion paper)
Panigati E., Schreiber F. A.
Proceedings of the 22nd Italian Symposium on Advanced database Systems SEBD 2014 pp. 175 - 184, 2014

 
Abstract: In this paper, we claim that there are complementary features which can bring different paradigms in the DM and PL domains to a fruitful cooperation in building Adaptive Systems. The data tailoring capabilities embedded in the PerLa sensor data management language have been extended, thus applying context-awareness to generic system operations; these operations, in turn, can be expressed as Layers in a Context Oriented Programming language.
 
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Extracting Data from WSNs: A Data-Oriented Approach
Schreiber F.A., Camplani R., Rota G.
Cap. 18 in Anastasi, G.; Bellini, E.; Elisabetta, D.N.; Ghezzi, C.; Tanca, L.; Zimeo, E. (Eds.) Methodologies and Technologies for Networked Enterprises
LNCS, Vol. 7200, Springer, (DOI: 10.1007/978-3-642-31739-2), pp. 357-372, 2012
 
Abstract: The PerLa language and the related middleware have been developed to ease the task of querying heterogeneous devices in pervasive systems. This paper presents, in a detailed way, some of the main features of the PerLa language by showing how it can be applied to the wine production process.
 
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Experiments and analysis of quality and Energy-aware data aggregation approaches in WSNs
Cappiello C., Schreiber F.A.
10th International Workshop on Quality in Databases QDB 2012 (Co-located with VLDB 2012)
Istanbul, Aug. 26, 2012, pp. 1-8
 
Abstract: A wireless sensor network consists of autonomous devices able to collect various data from the area that surrounds them. However, the resources associated with sensors are limited and, thus, in order to guarantee a longer life of all the network components, it is necessary to adopt energy-savings methods. This paper, considering that the transmission phase is the main cause of energy dissipation, presents an approach aimed to save energy by capturing and aggregating signals instead of sending them in raw form. Anyway, aggregation should not imply the loss of useful data. For this reason, information about possible outliers is preserved and the aggregated values have to satisfy data quality (i.e., accuracy, precision, and timeliness) requirements. In order to show the correctness and validity of the proposed method, it has been tested on a real case study and its performance has been compared with two other consolidated approaches.
 
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Pushing context-awareness down to the core: more flexibility for the PerLa language
Schreiber F. A., Tanca L., Camplani R., Vigano D.
Electronic Proceedings of the 6th PersDB 2012 Workshop (Co-located with VLDB 2012)
Istanbul, Aug. 31, 2012, pp. 1-6,
 
Abstract: Information technology is increasingly pervading our environment, making real Mark Weiser's vision of a "disappearing technology". The work described in this paper focuses on using context to enable pervasive system personalization, allowing context-aware sensor-data tailoring. Since sensor networks, besides data collection, are also able to produce active behaviours, the tailoring capabilities are also extended to these, thus applying context-awareness to generic system operations. Moreover, because the number of pos- sible context can grow rapidly with the complexity of the application, the design phase is also supported by the possi- bility to speed-up and modularize the definition of the data and operations associated with each specific context, pro- ducing a support tool that eases the job of the designers of modern context-aware pervasive systems.
 
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Towards autonomic pervasive systems: the PerLa context language
F. A. Schreiber, L. Tanca, R. Camplani, D. Vigano'
Proceedings of the 6th International Workshop on Networking Meets Databases Co-located with SIGMOD 2011
Athens, June 12-16, 2011
 
Abstract: The property of context-awareness, inherent to a Pervasive System, requires a clear definition of context and of how the context parameter values must be extracted from the real world. Since often the same variables are common to the operational system and to the context it operates into, the usage of the same language to manage both the application and the context can lead to substantial savings in application development time and costs. In this paper we propose a context-management extension to the PerLa language and middleware that allows for declarative gathering of context data from the environment, feeding this data to the internal context model and, once a context is active, acting on the relevant resources of the pervasive system, according to the chosen contextual policy.
 
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Managing and using context information within the PerLa language
F. A. Schreiber, L. Tanca, R. Camplani, D. Vigano'
Proceedings of the 19th Italian Symposium on Advanced database Systems SEBD 2011
Maratea, June 26-29, 2011 pp. 111 - 118
 
Abstract: Self-adaptability in pervasive real-world applications can be achieved by adopting a context-aware middleware. In this paper, we pro- pose a context-management extension to the PerLa language and mid- dleware, which allows for: (i) gathering of data from the environment, (ii) feeding this data to the internal context model and, (iii) once a con- text is active, acting on the relevant resources of the pervasive system, according to the chosen contextual policy.
 
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Context Modelling and Context Awareness: steps forward in the Context-ADDICT project
Cristiana Bolchini and Giorgio Orsi and Elisa Quintarelli and Fabio A. Schreiber and Letizia Tanca
Bulletin of the Technical Committee on Data Engineering
June 2011
 
Abstract: We give an account of the researches on context-aware information tailoring which are going on within the PEDiGREE group at Politecnico di Milano, starting from a foundational framework for the lifecycle of context-aware information systems, in which the system design and management activities consider context as an orthogonal, first-class citizen. The design-time and run-time activities involved in this life-cycle provide material for stimulating research, summarized in this paper
 
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Design of PerLa, a Declarative Language and a Middleware Architecture for Pervasive Systems
Fabio A. Schreiber, Romolo Camplani, Marco Fortunato, Marco Marelli, Guido Rota
Politecnico di Milano
Project FIRB Art-Deco Deliverable R.A. 11.1b, pp. 1-141
 
Abstract: This project aims at defining a completely declarative language to deal with wireless sensor networks and, more generally, with pervasive systems. In this work the main problems to be considered for the design of such a language are presented and discussed. Then, a software architecture for pervasive systems is introduced and a language proposal is presented. They allow to collect data from different nodes of a pervasive system and managing them, hiding the complexity due to the large underlying heterogeneity of devices, which can span from passive RFID(s) to ad-hoc sensor boards and to portable computers. An important feature of the presented middleware is to make the integration of new technologies in the system easy, through the use of device self-description. Finally, some simple examples are reported to show how the language can be used by a final user. The considered case study is related to the monitoring of the wine production process from the vineyard to the table.
 
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PerLa: A Language and Middleware Architecture for Data Management and Integration in Pervasive Information Systems
Fabio A. Schreiber, Romolo Camplani, Marco Fortunato, Marco Marelli, Guido Rota
IEEE Transactions on Software Engineering
http://doi.ieeecomputersociety.org/10.1109/TSE.2011.25
 
Abstract: A declarative SQL-like language and a middleware infrastructure are presented for collecting data from different nodes of a pervasive system. Data management is performed by hiding the complexity due to the large underlying heterogeneity of devices, which can span from passive RFID(s) to ad-hoc sensor boards to portable computers. An important feature of the presented middleware is to make the integration of new device types in the system easy, through the use of device self-description. Two case studies are described for PerLa usage, and a survey is made for comparing our approach with other projects in the area
 
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Data Management in Pervasive Systems
Schreiber F.A. (invited)
Scirus Topic Pages, Electronic publication, Elsevier
2008
 
Abstract: In a very short time, the interest for Wireless Sensors Networks and their applications has grown both within the academic community and, even if with some cautions [1], in the world of actual users. At the same time, the complexity of the envisaged WSN-based systems grew from a handful of homogeneous sensors to hundreds or thousands of devices differing as to their capabilities, architectures, and languages. The result of this inflationary expansion is the difficulty an application programmer encounters in dealing with the languages and protocols, which characterize different portions of the system, and in optimizing sampling, storage and transmission strategies in order to save as much as possible power in the batteries, which are the most critical components in a system of mostly unattended small devices.
 
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Quality- and Energy-Aware Data Compression by Aggregation in WSN Data Streams
Cinzia Cappiello, Fabio A. Schreiber
Proc. of the Seventh Annual IEEE International Conference on Pervasive Computing and Communications (PerCom 2009)
Galveston (Tx), pp. 634-639, 2009
 
Abstract: Sensor networks consist of autonomous devices that cooperatively monitor an environment. Sensors are equipped with capabilities to store information in memory, process information and communicate with neighbors and with a base station. However, due to the sensors' size, their associated resources are limited. In such a context, the main cause of energy dissipation is the use of the wireless link. Solutions that minimize communication are needed. In this paper a framework to manage efficiently data streams is presented. The proposed approach aims at saving energy by capturing signals and compress them instead of sending them in raw form. The algorithm also guarantees that the compressed representation satisfies quality requirements specified in terms of accuracy, precision, and timeliness.
 
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PERLA: A Declarative Language and Middleware for Pervasive Systems
Schreiber F.A., Camplani R., Fortunato M., Marelli M.
Adjunct Proceedings - Posters and Demo Abstracts, 3rd EuroSSC
Zurich, 2008, pp. 19-20
 
Abstract: The system presented in this paper aims at managing, with a unique language, data sampled from different nodes of a pervasive system, providing them to the final user. It is composed of three elements: the nodes are heterogeneous devices equipped with sensors, which collect data and send them through the network managed by the middleware; PERLA (PERvasive LAnguage) is the SQL like language used to query logical objects, that are abstractions of the nodes; the middleware is a stack of software layers providing an implementation of the logical object abstraction. Answers to the queries take into account the context the system operates within, in order to provide the user with data appropriate to different environmental conditions.
 
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PERLA: a Data Language for Pervasive Systems
Schreiber F.A., Camplani R., Fortunato M., Marelli M., Pacifici F.
Proc. of the Sixth Annual IEEE International Conference on Pervasive Computing and Communications (PerCom 2008)
Hong Kong, 2008, pp. 282-287
 
Abstract: A language is presented for managing data in highly pervasive systems made of very different devices as to their technology and functional capabilities. Functional and nonfunctional requirements are dealt with in a transparent mode by a SQL like interface. In this paper the most relevant features of the language, the related data structures and some query examples are briefly introduced.
 
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Automatic Generation of Sensor Queries in a WSN for Environmental Monitoring
Schreiber F.A.
Proc. 4th Int. ISCRAM Conference
Delft, May 2007, pp. 245-254
 
Abstract: The design of a WSN for environmental data monitoring is a largely ad-hoc human process. In this paper, we propose the automatic generation of queries for sensor data extraction, based on the collection of a number of parameters concerning the physical phenomenon to be controlled, the relevant physical variables, the types of sensors to be deployed and their allocation, the data collection frequencies, and other features.