Article de revue avec comité de lecture (8)
GRAIET Mohamed, MAMMAR Amel, BOUBAKER Souha, GAALOUL Walid
Towards correct cloud resource allocation in business processes. IEEE transactions on services computing, january 2017, vol. 10, n° 1, pp. 23-36
abstract
Cloud environments are being increasingly used for deploying and executing business processes to provide a high level of performance with low operating cost. Nevertheless, due to the lack of an explicit and formal description of the resource perspective in the existing business processes, the correctness of Cloud resources management can not be verified. The aim of the present work is to offer a formal definition of the resource perspective in business processes as a step towards ensuring a correct and consistent Cloud resource allocation in business process modeling. Concretely, we propose a formalism based on the Event-B language for specifying Cloud resource allocation policies in business process models. This formal specification is used to formally validate the consistency of Cloud resource allocation for process modeling at design time, and to analyze and check its correctness according to user requirements and resource capabilities. In order to show its feasibility, our approach has been tested using a real use case study from an industrial partner.
MAMMAR Amel, LALEAU Régine
Modeling a landing gear system in Event-B. International journal on software tools for technology, april 2017, vol. 19, n° 2, pp. 167-186
abstract
This article describes the Event-B modeling of a landing gear system of an aircraft. This real-life case study has been proposed by the ABZ'2014 track that took place in Toulouse, the European capital of the aeronautic industry. Our modeling is based on the Parnas and Madey's 4-Variable Model that permits to consider the different parts of a system. These parts are incrementally introduced using the Event-B refinement technique. The entire development has been carried out with the Rodin toolset. To ensure the correctness of the different components, we use several verification techniques (animation, model-checking and proof) depending on the complexity and the kind of the properties to verify. Basically, prior to the proof phase that can be tedious and complex, we use the animator AnimB and the model checker ProB that permit to discover some trivial inconsistencies. Once no error is reported, we start the proof phase by using the Atelier B and SMT provers which we installed on Rodin. We conclude the article by drawing up some key findings of and lessons learned from this experience
QI Chengming , ZHOU Zhangbing , SUN Yunchuan , SONG Houbing , HU Lishuan , WANG Qun
Feature selection and multiple kernel boosting framework based on PSO with mutation mechanism for hyperspectral classification. Neurocomputing, january 2017, vol. 220, pp. 181-190
abstract
Hyperspectral remote sensing sensors can capture hundreds of contiguous spectral images and provide plenty of valuable information. Feature selection and classification play a key role in the field of HyperSpectral Image (HSI) analysis. This paper addresses the problem of HSI classification from the following three aspects. First, we present a novel criterion by standard deviation, Kullback-Leibler distance, and correlation coefficient for feature selection. Second, we optimize the SVM classifier design by searching for the most appropriate value of the parameters using particle swarm optimization (PSO) with mutation mechanism. Finally, we propose an ensemble learning framework, which applies the boosting technique to learn multiple kernel classifiers for classification problems. Experiments are conducted on benchmark HSI classification data sets. The evaluation results show that the proposed approach can achieve better accuracy and efficiency than state-of-the-art methods.
WANG Leye, ZHANG Daqing, XIONG Haoyi, GIBSON John Paul, CHEN Chao, XIE Bing
ecoSense: minimize participants' total 3G data cost in mobile crowdsensing using opportunistic relays. IEEE transactions on systems, man, and cybernetics. Systems, june 2017, vol. 47, n° 6, pp. 965-978
abstract
In mobile crowdsensing, one of the participants' main concerns is the cost for 3G data usage, which affects their willingness to participate in a crowdsensing task. In this paper, we present the design and implementation of a mobile crowdsensing data uploading mechanism - ecoSense - to help reduce additional 3G data cost incurred by the whole crowd of sensing participants. By considering the two most-common real-life 3G price plans - Unlimited Data Plan (UnDP) and Pay As You Go (PAYG), ecoSense partitions all the users into two groups corresponding to these two price plans at the beginning of each month, with the objective of minimizing the total refunding budget for all participants. The partitioning is based on predicting users' mobility patterns and sensed data size. The ecoSense mechanism is designed inspired by the observation that during the data uploading cycles, UnDP users could opportunistically relay PAYG users' data to the crowdsensing server without extra 3G cost, provided the two types of users are able to "meet" on a common local cost- free network (e.g. Bluetooth or WiFi Direct). We conduct our experiments using both the MIT Reality Mining and the SWIM simulation datasets. Evaluation results show that ecoSense could reduce total 3G data cost by up to ∼50%, when compared to the direct-assignment method that assigns each participant to UnDP or PAYG directly according to the size of her sensed data
XIANG Jianming , ZHOU Zhangbing , SHU Lei , RAHMAN Taj , WANG Qun
A mechanism filling sensing holes for detecting the boundary of continuous objects in hybrid sparse wireless sensor networks. IEEE access, january 2017, vol. 5, pp. 7922-7935
abstract
Nowadays, the rapidly developed Internet of Things require the ability handling information efficiently to deal with the intelligent applications. Wireless sensor networks (WSNs), which act as an important interface between physical environment and Internet of Things, have been applied in numerous applications. As a kind of important application of WSNs, the continuous objects boundary detection is popular in industry. However, the long-term maintenance for the traditional WSNs, which are used to monitor the leakage of continuous objects, is expensive. Thus, we use sparse WSNs to address this issue. But, the inaccuracy of the sparse network is a big problem while the information of continuous objects is used to arrange retreat path for people. To access this problem, we propose our mechanism which used hybrid network to compromise the accuracy and cost of maintenance. The sensing holes will be detected by using Voronoi diagram, before the network starts to work. After the static sensor nodes get the value of the toxic air, the mechanism can calculate the high variation location, which give weights to the sensing holes, in the static sensor networks. Thus, the sensing holes which selected by both spatial and data variation factors will be list in a target nodes list for the mobile sensor node. Finally, the optimal path considering both distance and priority for the mobile sensor will be plan out. Experimental evaluation shows that there is an optimal amount of the static nodes decided by the sensing radius and the size of area. And it reduces the energy consumption by the static networks.
ZHOU Zhangbing , CHENG Zehui, ZHANG Liang-Jie, GAALOUL Walid, NING Ke
Scientific workflow clustering and recommendation leveraging layer hierarchical analysis. IEEE transactions on services computing, 2017, pp. 1-14 (document in press - published online 16 Mar 2016)
abstract
This article proposes an approach for identifying and recommending scientific workflows for reuse and repurposing. Specifically, a scientific work- flow is represented as a layer hierarchy, which specifies hierarchical relations between this workflow, its subworkflows, and activities. Semantic similarity is calculated between layer hierarchies of workflows. A graphskeleton based clustering technique is adopted for grouping layer hierarchies into clusters. Barycenters in each cluster are identified, which refer to core workflows in this cluster, for facilitating cluster identification and workflow ranking and recommendation. Experimental evaluation shows that our technique is efficient and accurate on ranking and recommending appropriate clusters and scientific workflows with respect to specific requirements of scientific experiments.
ZHOU Zhangbing , ZHAO Deng, HANCKE Gerhard , SHU Lei , SUN Yunchuan
Cache-aware query optimization in multi-application sharing wireless sensor networks. IEEE transactions on systems, man, and cybernetics. Systems, 2017, pp. 1-17 (document in press - published online 24 Aug 2016)
abstract
Hosting multiple applications in a shared infrastructure of wireless sensor networks is a trend nowadays, and sharing sensory data for answering concurrent applications is a promising and energy-efficient strategy. To address this challenge, this paper proposes an energy-efficient query optimization mechanism for supporting multiple concurrent applications leveraging our two-tier cooperative caching mechanism. Specifically, query requests for concurrent applications are represented as binary strings, which are reduced to a single one for avoiding the reprocessing of shared subquery requests. This reduced query request is answered through our cooperative caching mechanism, where sensory data, which are highly possible to be reused for answering forthcoming query requests, are cached at the sink node (SN). Besides, the gray model GM(1, 1) is adopted for forecasting sensory data units which may be interested mostly by forthcoming query requests. These units of sensory data may be prefetched from the network and cached at the SN. Experimental evaluation shows that this approach can reduce the energy consumption significantly, and improve the network capacity to an extent, especially when the number of concurrent query requests is relatively large
ZUO Liyun , SHU Lei , DONG Shoubin , ZHU Chunsheng , ZHOU Zhangbing
Dynamically weighted load evaluation method based on self-adaptive threshold in cloud computing. Mobile Networks & Applications, february 2017, vol. 22, n° 1, pp. 4-18
abstract
Cloud resources and their loads possess dynamic characteristics. Current research methods have utilized certain physical indicators and fixed thresholds to evaluate cloud resources, which cannot meet the dynamic needs of cloud resources or accurately reflect their resource states. To address this challenge, this paper proposes a Self-adaptive threshold based Dynamically Weighted load evaluation Method (termed SDWM). It evaluates the load state of the resource through a dynamically weighted evaluation method. First, the work proposes some dynamic evaluation indicators in order to evaluate the resource state more accurately. Second, SDWM divided the resource load into three states, including Overload, Normal and Idle using the self-adaptive threshold. It then migrated those overload resources to a balance load, and releases the idle resources whose idle times exceeded a threshold to save energy, which could effectively improve system utilization. Finally, SDWM leveraged an energy evaluation model to describe energy quantitatively using the migration amount of the resource request. The parameters of the energy model were obtained from a linear regression model according to the actual experimental environment. Experimental results showed that SDWM is superior to other methods in energy conservation, task response time, and resource utilization, and the improvements are 31.5 %, 50 %, 50.8 %, respectively. These results demonstrate the positive effect of the dynamic self-adaptive threshold. More specially, SDWM shows great adaptability when resources dynamically join or exit
Communication dans une conférence à comité de lecture (4)
EL RACHKIDI Elie, AGOULMINE Nazim, BELAID Djamel, CHENDEB Nada
Towards an efficient service provisioning in Cloud of Things (CoT). GLOBECOM 2016 : IEEE Global Communications Conference, Los Alamitos : IEEE Computer Society, 04-08 december 2016, Washington, Dc, United States, 2017, pp. 1-6, ISBN 978-1-5090-1328-9
abstract
The Cloud offers virtually unlimited resources and the ability to scale up or down applications as needed on the fly. Hence, the Cloud emerged as a suitable solution for large-scale IoT applications to cope with the rapidly increasing devices and data volume. Furthermore, IoT broadened the scope of the Cloud to the real world and enabled new service models such as the Sensing as a Service model. The convergence of both technologies stimulated innovations in both fields, we refer to this convergence as the Cloud of Things. The Cloud of Things enables users to request a complex IoT service (IoT application composed of several interconnected micro services) and deploy it seamlessly. However, deploying a complex IoT service in the Cloud of Things infrastructure is a difficult process due to the different types of physical nodes (Cloud data centers, IoT devices, gateways, etc.) and multiple architectures to collect and process data. Furthermore, network usage largely depends on the placement of different services across the network. In this paper, we present an efficient provisioning model of IoT services formulated as a Mixed Integer Problem. The objective is to minimize the cost of the deployment of IoT services in Cloud of Things infrastructure, through optimizing resources usage across physical nodes and bandwidth consumption over the network
HUYNH Nghi, FRAPPIER Marc, MAMMAR Amel, LALEAU Régine
Verification of SGAC access control policies using Alloy and ProB. HASE 2017 : 18th International Symposium on High Assurance Systems Engineering, Los Alamitos : IEEE Computer Society, 12-14 january 2017, Singapore, Singapore, 2017, pp. 120-123, ISBN 978-1-5090-4636-2
abstract
This paper investigates the verification ofaccess control policies for SGAC, a new healthcare access-control model, using Alloy and ProB, two first orderlogic model checkers based on distinct technologies.SGAC supports permission and prohibition, ruleinheritance among subjects and resources and conflictsresolution. In order to protect patient privacy while ensuringeffective caregiving in safety-critical situations, we check different properties such as accessibility, ineffectiverule detection. Our performance results showthat ProB performs two orders of magnitude betterthan Alloy. Results are promising enough to considerProB for verifying patient policies in SGAC
SUTRA Pierre, RIVIÈRE Etienne, COTES Cristian, SÁNCHEZ ARTIGAS Marc, GARCIA LOPEZ Pedro , BERNARD Emmanuel, BURNS William, ZAMARREÑO Galder
CRESON: Callable and Replicated Shared Objects over NoSQL. ICDCS 2017 : IEEE 37th International Conference on Distributed Computing Systems, Los Alamitos : IEEE Computer Society, 05-08 june 2017, Atlanta, United States, 2017, pp. 115-128, ISBN 978-1-5386-1792-2
abstract
In a Cloud environment, the ability to share and persist objects simplifies the design of applications. Storing objects in a NoSQL database ensures their availability and provides scalability to applications. When Object-NoSQL Mapping is performed at the client side, objects that are accessed by several clients are repeatedly converted between their in-memory and serialized representations. This negatively impacts performance and increases replication costs. In this paper, we describe the design of CRESON, a system supporting callable objects over NoSQL, in which application objects are mapped and instantiated directly on the storage nodes. CRESON supports composition by reference and ensures strong consistency. Objects are replicated and maintained coherent using State Machine Replication. The implementation of CRESON leverages the support of a listenable key-value store (LKVS), a novel NoSQL storage abstraction that we introduce in this paper. We discuss the performance and complexity of CRESON with the example of the portage of a personal cloud storage service, initially developed using an object-relational mapping over a sharded PostgreSQL database. Our results show that CRESON offers a simpler programming experience both in terms of learning time and lines of code, while performing better on average and being more scalable
VORON Gauthier, THOMAS Gaël, QUÉMA Vivien, SENS Pierre
An interface to implement NUMA policies in the Xen hypervisor. EuroSys 2017 : 12th European Conference on Computer Systems, New-York : ACM, 23-26 april 2017, Belgrade, Serbia, 2017, pp. 453-467, ISBN 978-1-4503-4938-3
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abstract
While virtualization only introduces a small overhead on machines with few cores, this is not the case on larger ones. Most of the overhead on the latter machines is caused by the Non-Uniform Memory Access (NUMA) architecture they are using. In order to reduce this overhead, this paper shows how NUMA placement heuristics can be implemented inside Xen. With an evaluation of 29 applications on a 48-core machine, we show that the NUMA placement heuristics can multiply the performance of 9 applications by more than 2
Modifié le 2 octobre 2012
