Nadia Bennani

A distributed coordination platform for home care: analysis, framework and prototype

Good cooperation between health care (HC) professionals, patient, and family is indispensable during homecare as mentioned in reports and analyses from different countries. In a French National project named coordination for the quality of care (COQUAS), we aimed to address the problem of improving such cooperation with current tools and techniques. We hypothesized that, as in some other domains, a better integration of use and users in informatics systems could improve the usefulness of the cooperative tool. The first part of this paper is devoted to the cognitive analysis of the homecare process and highlights the requirements which should be met according to this analysis. We describe some specific features of asynchronous cooperation and some communication issues in the cooperation of HC workers. We then detail the analysis of the homecare process: methodology, description of the processes, cognitive activity analyses, and of the requirements which flow from this analysis. The second part of this paper proposes a framework and then describes a modular system prototype, designed to take into account these requirements, including aspects of both cooperation and interoperability. It uses a meta-description of actions and information derived from a cognitive study to build dynamically the interface settings; it respects the current trend in distributed architecture and uses XML communication of messages, manages complex coordination with a workflow and allows mobile work. The last part of the paper presents the evaluation which has been done with the implemented prototype, with actual homecare users.

A Survey on User Modeling in Multi-application Environments

Sharing heterogeneous data among distributed environments in a user-centric way represents today the main challenge for personalization. In recent years several techniques have been proposed to support user modeling for cross-system personalization, following two main approaches. A first group of researchers base their solutions on the use of a top-down approach, involving standard ontologies or unified user models (standardization-based user modeling); in a second research direction, a bottom-up approach based on mappings between different user model representations is the envisaged solution (mediation-based user modeling). The aim of this paper is to discuss general problems connected to user modeling in multiapplication environments and to provide a short survey on current research in this field. Based on this, we briefly draw out some further research.

A Discussion of Privacy Challenges in User Profiling with Big Data Techniques: The EEXCESS Use Case

User profiling is the process of collecting information about a user in order to construct their profile. The information in a user profile may include various attributes of a user such as geographical location, academic and professional background, membership in groups, interests, preferences, opinions, etc. Big data techniques enable collecting accurate and rich information for user profiles, in particular due to their ability to process unstructured as well as structured information in high volumes from multiple sources. Accurate and rich user profiles are important for applications such as recommender systems, which try to predict elements that a user has not yet considered but may find useful. The information contained in user profiles is personal and thus there are privacy issues related to user profiling. In this position paper, we discuss user profiling with big data techniques and the associated privacy challenges. We also discuss the ongoing EU-funded EEXCESS project as a concrete example of constructing user profiles with big data techniques and the approaches being considered for preserving user privacy.

Toward Cloud-Based Key Management for Outsourced Databases

A major drawback of implementing Database-as-a-Service (DaaS) on untrusted servers is the complexity of key management required for handling revocation. In this paper we put forward the idea of using the cloud for decoupling the management of local, user-specific encryption keys from the one of role-specific protection keys, obtaining simple key management and revocation schemes.Compact reactive lumped-element circuits fabricated using a single thick metal-layer deep X-ray lithography process are presented. Vertically oriented capacitive features are combined with inductive features in >0.25-mm-thick metal layers to realize lumped-element filter and coupler microstructures operating at up to 12 GHz. Measurements for separate thick metal reactive structures are also presented, including variable capacitors and single-turn square loop inductors. Devices feature impressive vertical structure, including a 77:1 aspect ratio, 1.3-μm-wide cantilever gap structure in 100-μm-thick photoresist. A 0.6-pF capacitor has -factors of 95 at 5.6 GHz and 214 at 3.5 GHz, and a structurally compatible 1.2-nH loop inductor has a -factor of 47 at 6.8 GHz and a self-resonant frequency of 18.8 GHz. Together, these types of devices could form the building blocks for various integrated reactive lumped-element-based circuits.

Distributed Key Management in Dynamic Outsourced Databases: A Trie-Based Approach

The decision to outsource databases is strategic in many organizations due to the increasing costs of internally managing large volumes of information. The sensitive nature of this information raises the need for powerful mechanisms to protect it against unauthorized disclosure. Centralized encryption to access control at the data owner level has been proposed as one way of handling this issue. However, its prohibitive costs renders it impractical and inflexible. A distributed cryptographic approach has been suggested as a promising alternative, where keys are distributed to users on the basis of their assigned privileges. But in this case, key management becomes problematic in the face of frequent database updates and remains an open issue. In this paper, we present a novel approach based on Binary Tries. By exploiting the intrinsic properties of these data structures, key management complexity, and thus its cost, is significantly reduced. Changes to the Binary Trie structure remain limited in the face of frequent updates. Preliminary experimental analysis demonstrates the validity and the effectiveness of our approach.

CoFFee: Cooperative and inFrastructure-Free peer-to-peer system for VANET

Peer-to-peer systems in vehicular ad hoc networks are the scope of intensive research in last few years. Several proposed content sharing systems in the literature are based on a hybrid infrastructure containing static gateways that manage the file sharing between the vehicles. In this paper, we present CoFFee, a Cooperative and inFrastructure-Free peer-to-peer system, where the network do not rely on a preexisting infrastructure. The cooperative behavior of the nodes during the file sharing process is the main contribution of CoFFee. We evaluated CoFFee using OMNET++ simulation environment. The first simulation results when applying our content distribution algorithm are very promising.

CReaM: User-Centric Replication Model for Mobile Environments

Data replication can improve data availability in mobile networks; but due to typical resource limitations in such environments, specific replication mechanisms are needed. In this paper, we propose CReaM, user-Centric REplicAtion Model for mobile environment. This model puts users at the centre by letting them determine the amount of resources they are willing to share. CReaM is suitable for dynamic environments where each node needs a certain level of decision autonomy. In this paper, we present CReaMs general principles and focus on one of its core function, which is its autonomic behavior that generates replication requests based on resources monitoring and user settings.

Multi-application profile updates propagation: a semantic layer to improve mapping between applications

In the field of multi-application personalization, several techniques have been proposed to support user modeling for user data management across different applications. Many of them are based on data reconciliation techniques often implying the concepts of static ontologies and generic user data models. None of them have sufficiently investigated two main issues related to user modeling: (1) profile definition in order to allow every application to build their own view of users while promoting the sharing of these profiles and (2) profile evolution over time in order to avoid data inconsistency and the subsequent loss of income for web-site users and companies. In this paper, we conduct work and propose separated solutions for every issue. We propose a flexible user modeling system, not imposing any fixed user model whom different applications should conform to, but based on the concept of mapping among applications (and mapping functions among their user attributes). We focus in particular on the management of user profile data propagation, as a way to reduce the amount of inconsistent user profile information over several applications. A second goal of this paper is to illustrate, in this context, the benefit obtained by the integration of a Semantic Layer that can help application designers to automatically identify potential user attribute mappings between applications. This paper so illustrates a work-in-progress work where two complementary approaches are integrated to improve a main goal: managing multi-application user profiles in a semi-automatic manner.

Performance Evaluation for CReaM: User-Centric Replication Model

The deployment of applications in mobile networks is hindered by limited resources and frequent network disconnection. Data replication can improve data availability in mobile networks but also introduces the problem of adequately disseminating data without abusing user and network resources. In this context, we present CReaM, a user-Centric REplicAtion Model for mobile environment that privileges the users by letting them determine the amount of resources they assign to the system. In this paper, we focus on CReaMs autonomic behavior that generates replication requests based on resource monitoring and user settings. Then, we present a simulation-based evaluation of CReaM, which shows the efficiency of the model.

A distributed and privacy-preserving method for network intrusion detection

Organizations security becomes increasingly more difficult to obtain due to the fact that information technology and networking resources are dispersed across organizations. Network intrusion attacks are more and more difficult to detect even if the most sophisticated security tools are used. To address this problem, researchers and vendors have proposed alert correlation, an analysis process that takes the events produced by the monitoring components and produces compact reports on the security status of the organization under monitoring. Centralized solutions imply to gather from distributed resources by a third party the global state of the network in order to evaluate risks of attacks but neglect the honest but curious behaviors. In this paper, we focus on this issue and propose a set of solutions able to give a coarse or a fine grain global state depending on the system needs and on the privacy level requested by the involved organizations.