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2010, Lamjed Ben Said, , ,
Toward a Privacy Enhancing Framework in E-government.
In : CAiSE Forum. 2010., 2010
Abstract
E-government involves data sharing between different partners such
as citizens and government agencies. Thus, the use of personal data in such
cooperative environment must be done in legal ways and for legal purposes. In
this context, issues related to data protection, such as privacy, have to be
considered. This paper adopts a multi-agent based approach to manage privacy
concerns in e-government systems. The proposed model provides a mechanism
for e-government systems to evaluate trust degree reached by digital
government processes. For this purpose, concepts of responsibility proposed in
multi-agent systems and access rights used in security models, are integrated in
this work. The research provides an evaluative framework for trust degree
related to e-government process.Mohamed Hmiden, Lamjed Ben Said,A two-step transshipment model with fuzzy demands and service level constraints
International journal of simulation modelling, 9(1), 40-52., 2010
Abstract
We consider a distribution network composed of one supplier and several non-identical locations characterized by fuzzy customer demands and service level constraints. These locations could cooperate together via product transfer known as transshipment. The transshipment problem consists in determining the replenishment quantities that minimize the total inventory cost where a specific transfer policy is practiced. Our objectives in this paper are to identify an inter-location transfer policy that participates to satisfy the service level constraints and to determine the approximate replenishment quantities. To achieve these objectives we propose:(1) a new transshipment model based on the chance constrained programming,(2) a two-step transshipment policy that differs from classic ones by product transfer from locations in need to others also in need and (3) a hybrid algorithm based on fuzzy simulation and genetic algorithms to approximate replenishment quantities.
, Lamjed Ben Said,ABC: A new Privacy Enhancing Model for eGovernment
In ECEG2010-Proceedings of the 10th European Conference on E-Government: National Center for Taxation Studies University of Limerick, Ireland 17-18 June 2010 (p. 207). Academic Conferences Limited., 2010
Abstract
The use of eGovernment systems requires the collection of a big amount of personal data of citizens in every transaction. In such context, issues related to privacy, such as data collection and disclosure of personal information without any predefined purpose, have to be considered. In this paper, we propose a new multi-agent based model, called ABC, and used to handle privacy issues in eGovernment. The proposed model offers the possibility to statistically assess trust degree for a given eGovernment process. Also, a case study is used to simulate and to illustrate the applicability of the proposed model.
, Lamjed Ben Said, ,Multi-agent based simulation of animal food selective behavior in a pastoral system
In: Jędrzejowicz, P., Nguyen, N.T., Howlet, R.J., Jain, L.C. (eds) Agent and Multi-Agent Systems: Technologies and Applications. KES-AMSTA 2010. Lecture Notes in Computer Science(), vol 6070. Springer, Berlin, Heidelberg., 2010
Abstract
Pastoral systems are considered as complex systems, given the number of entities and the multitude of interactions and levels of granularity. To conduct a study of such system taking into account the interactions and their results, analytical approaches are not adequate. In this paper, we present an agent-based model of the animal behavior in the pastoral system taking into account the selective food aspect. This model has been validated using a multi-agent based simulation implemented on the simulation platform Cormas. The obtained results reflect the importance of this aspect in the animal behavior and its effects on vegetation cover.
Meriam Jemel, Nadia Ben Azzouna,Towards a dynamic access control model for e-government web services
In Proceedings of the 2010 IEEE Asia-Pacific Services Computing Conference (APSCC'10), December 6-10 2010, Hangzhou, China, pages 433-440, IEEE Computer Society, 2010
Abstract
The need of interoperable e-government services is addressed through the use of web services where sensitive services need to be granted to only authorized subjects from different organizations. In this paper, we propose a Trust and Dynamic Role Based Access Control model (TDRBAC) which deals with the specific requirements of e-government services. It effectively enhances the access control level since it is based on the trust level notion. The trust level evaluation is based on contextual attributes to assign to user role the appropriate view during the active session. The TDRBAC model is sensitive to the internal or external arisen events and it incorporates them in the access decision which makes it suitable for e-government dynamic environment.
Kalthoum RezguiHow to Support Disabled and Non-disabled Learners with the ACCLIP Information Model
-, 2010
Abstract
Although the extent and the nature of difficulties in learning are more severe for disabled students, non-disabled students may also have similar requirements and want to give them the ability to express preferences about display, control and content. In this paper, we propose using the IMS Accessibility for LIP (ACCLIP) specification to express accessibility preferences and needs of learners. This specification allows describing accessibility needs other than those just for learners with physical disabilities to ensure that all learners can define preferences.
Saoussen Bel Haj Kacem, ,Approximate Reasoning based on Linguistic Modifiers in a Learning System
ICSOFT (2). 2010., 2010
Abstract
Approximate reasoning, initially introduced in fuzzy logic context, allows reasoning with imperfect knowledge. We have proposed in a previous work an approximate reasoning based on linguistic modifiers in a symbolic context. To apply such reasoning, a base of rules is needed. We propose in this paper to use a supervised learning system named SUCRAGE, that automatically generates multi-valued classification rules. Our reasoning is used with this rule base to classify new objects. Experimental tests and comparative study with two initial reasoning modes of SUCRAGE are presented. This application of approximate reasoning based on linguistic modifiers gives satisfactory results. Besides, it provides a comfortable linguistic interpretation to the human mind thanks to the use of linguistic modifiers.
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2009Wassim Ayadi, ,
A biclustering algorithm based on a Bicluster Enumeration Tree: application to DNA microarray data
BioData mining Volume 2 Numéro 1, 2009
Abstract
Background
In a number of domains, like in DNA microarray data analysis, we need to cluster simultaneously rows (genes) and columns (conditions) of a data matrix to identify groups of rows coherent with groups of columns. This kind of clustering is called biclustering. Biclustering algorithms are extensively used in DNA microarray data analysis. More effective biclustering algorithms are highly desirable and needed.
Methods
We introduce BiMine, a new enumeration algorithm for biclustering of DNA microarray data. The proposed algorithm is based on three original features. First, BiMine relies on a new evaluation function called Average Spearman’s rho (ASR). Second, BiMine uses a new tree structure, called Bicluster Enumeration Tree (BET), to represent the different biclusters discovered during the enumeration process. Third, to avoid the combinatorial explosion of the search tree, BiMine introduces a parametric rule that allows the enumeration process to cut tree branches that cannot lead to good biclusters.
Results
The performance of the proposed algorithm is assessed using both synthetic and real DNA microarray data. The experimental results show that BiMine competes well with several other biclustering methods. Moreover, we test the biological significance using a gene annotation web-tool to show that our proposed method is able to produce biologically relevant biclusters. The software is available upon request from the authors to academic users.
, Lamjed Ben Said,Evolutionary optimization of the multiobjective transshipment problem with limited storage capacity
In Winter Simulation Conference (pp. 2375-2383)., 2009
Abstract
In situations where some sellers have surplus stock while others, belonging to the same firm, are stocked out, it may be desirable to share the unsold units to fulfill more unmet demands and avoid holding costs. Such practice is named Transshipment. It ensures cost reduction and service level improvement. In this paper, we present a multiobjective study of a multi-location transshipment inventory which optimizes three objectives: (1) the aggregate cost, (2) the fill rate, and (3) the shared inventory quantity (SIQ), in the presence of different storage capacity constraints. Simulation is needed to evaluate the expected value of the problem stochastic objective functions. Two reference evolutionary multiobjective algorithms (SPEA2 and NSGA-II) are used to solve instances of the problem. Based on the obtained Pareto fronts, it is shown that both low aggregate cost and high fill rate levels could be ensured, while the shared inventory quantity is considerably increased.
Mohamed Hmiden, Lamjed Ben Said,Transshipment problem with uncertain customer demands and transfer lead time
In 2009 International Conference on Computers & Industrial Engineering (pp. 476-481). IEEE., 2009
Abstract
This paper deals with the transshipment problem characterized by the uncertainty relative to customer demands and transfer lead time. We consider a distribution network of one supplier and N locations selling an innovative product. The customer demands and the transfer lead time are evaluated based on expert judgments and they are consequently represented by fuzzy sets. Our aims in this work are: (1) to identify a transshipment policy that takes into account the fuzziness of customer demands and transfer lead times and (2) to determine the approximate replenishment quantities which minimize the total inventory cost. In order to achieve these aims, we propose a new transshipment policy where the transshipment decision is made within the period and the possible transshipment decision moments belong to a fuzzy set. We consider the decision maker behavior types (pessimistic and optimistic) to determine the precise transshipment decision moment and the transshipment quantity. We propose a hybrid algorithm based on fuzzy simulation and genetic algorithm to approximate the optimal replenishment quantities.
