Analytical study and computational modeling of statistical methods for data mining

Today, there is tremendous increase of the information available on electronic form. Day by day it is increasing massively. There are enough opportunities for research to retrieve knowledge from the data available in this information. Data mining and app

Modelling Web Usage in a Changing Environment

Eiben, A.E. [Promotor]Kowalczyk, W. [Copromotor

HIDE: User centred Domotic evolution toward Ambient Intelligence

Pervasive Computing and Ambient Intelligence (AmI) visions are still far from being achieved, especially with regard to Domotics and home applications. According to the vision of Ambient Intelligence (AmI), the most advanced technologies are those that disappear: at maturity, computer technology should become invisible. All the objects surrounding us must possess sufficient computing capacity to interact with users, the surroundings and each other. The entire physical environment in which users are immersed should thus be a hidden computer system equipped with the appropriate software in order to exhibit intelligent behavior. Even though many implementations have started to appear in several contexts, few applications have been made available for the home environment and the general public. This is mainly due to the segmentation of standards and proprietary solutions, which are currently confusing the market with a sparse offer of uninteroperable devices and systems. Although modern houses are equipped with smart technological appliances, still very few of these appliances can be seamlessly connected to each other. The objective of this research work is to take steps in these directions by proposing, on the one hand, a software system designed to make today’s heterogeneous, mostly incompatible domotic systems fully interoperable and, on the other hand, a feasible software application able to learn the behavior and habits of home inhabitants in order to actively contribute to anticipating user needs, and preventing emergency situations for his health. By applying machine learning techniques, the system offers a complete, ready-to-use practical application that learns through interaction with the user in order to improve life quality in a technological living environment, such as a house, a smart city and so on. The proposed solution, besides making life more comfortable for users without particular needs, represents an opportunity to provide greater autonomy and safety to disabled and elderly occupants, especially the critically ill ones. The prototype has been developed and is currently running at the Pisa CNR laboratory, where a home environment has been faithfully recreated

Efficient Learning Machines

Computer scienc

System-level functional and extra-functional characterization of SoCs through assertion mining

Virtual prototyping is today an essential technology for modeling, verification, and re-design of full HW/SW platforms. This allows a fast prototyping of platforms with a higher and higher complexity, which precludes traditional verification approaches based on the static analysis of the source code. Consequently, several technologies based on the analysis of simulation traces have proposed to efficiently validate the entire system from both the functional and extra-functional point of view. From the functional point of view, different approaches based on invariant and assertion mining have been proposed in literature to validate the functionality of a system under verification (SUV). Dynamic mining of invariants is a class of approaches to extract logic formulas with the purpose of expressing stable conditions in the behavior of the SUV. The mined formulas represent likely invariants for the SUV, which certainly hold on the considered traces. A large set of representative execution traces must be analyzed to increase the probability that mined invariants are generally true. However, this is extremely time-consuming for current sequential approaches when long execution traces and large set of SUV's variables are considered. Dynamic mining of assertions is instead a class of approaches to extract temporal logic formulas with the purpose of expressing temporal relations among the variables of a SUV. However, in most cases, existing tools can only mine assertions compliant with a limited set of pre-defined templates. Furthermore, they tend to generate a huge amount of assertions, while they still lack an effective way to measure their coverage in terms of design behaviors. Moreover, the security vulnerability of a firmware running on a HW/SW platforms is becoming ever more critical in the functional verification of a SUV. Current approaches in literature focus only on raising an error as soon as an assertion monitoring the SUV fails. No approach was proposed to investigate the issue that this set of assertions could be incomplete and that different, unusual behaviors could remain not investigated. From the extra-functional point of view of a SUV, several approaches based on power state machines (PSMs) have been proposed for modeling and simulating the power consumption of an IP at system-level. However, while they focus on the use of PSMs as the underlying formalism for implementing dynamic power management techniques of a SoC, they generally do not deal with the basic problem of how to generate a PSM. In this context, the thesis aims at exploiting dynamic assertion mining to improve the current approaches for the characterization of functional and extra-functional properties of a SoC with the final goal of providing an efficient and effective system-level virtual prototyping environment. In detail, the presented methodologies focus on: efficient extraction of invariants from execution traces by exploiting GP-GPU architectures; extraction of human-readable temporal assertions by combining user-defined assertion templates, data mining and coverage analysis; generation of assertions pinpointing the unlike execution paths of a firmware to guide the analysis of the security vulnerabilities of a SoC; and last but not least, automatic generation of PSMs for the extra-functional characterization of the SoC

Combining SOA and BPM Technologies for Cross-System Process Automation

This paper summarizes the results of an industry case study that introduced a cross-system business process automation solution based on a combination of SOA and BPM standard technologies (i.e., BPMN, BPEL, WSDL). Besides discussing major weaknesses of the existing, custom-built, solution and comparing them against experiences with the developed prototype, the paper presents a course of action for transforming the current solution into the proposed solution. This includes a general approach, consisting of four distinct steps, as well as specific action items that are to be performed for every step. The discussion also covers language and tool support and challenges arising from the transformation

Empirical Studies of Android API Usage: Suggesting Related API Calls and Detecting License Violations.

We mine the API method calls used by Android App developers to (1)suggest related API calls based on the version history of Apps, (2) suggest related API calls based on StackOverflow posts, and (3) find potential App copyright and license vio- lations based the similarity of API calls made by them. Zimmermann et al suggested that �Programmers who changed these functions also changed� functions that could be mined from previous groupings of functions found in the version history of a system. Our first contribution is to expand this approach to a community of Apps. Android developers use a set of API calls when creating Apps. These API methods are used in similar ways across multiple applications. Clustering co-changing API methods used by 230 Android Apps, we are able to predict the changes to API methods that individual App developers will make to their application with an average precision of 73% and recall of 25%. Our second contribution can be characterized as �Programmers who discussed these functions were also interested in these functions.� Informal discussion on Stack- Overflow provides a rich source of related API methods as developers provide solu- tions to common problems. Clustering salient API methods in the same highly ranked posts, we are able to create rules that predict the changes App developers will make with an average precision of 64% and recall of 15%. Our last contribution is to find out whether proprietary Apps copy code from open source Apps, thereby violating the open source license. We have provided a set of techniques that determines how similar two Apps are based on the API calls they make. These techniques include android API calls matching, API calls coverage, App categories, Method/Class clusters and released size of Apps. To validate this approach we conduct a case study of 150 open source project and 950 proprietary projects