An applied mathematics perspective on stochastic modelling for climate

Systematic strategies from applied mathematics for stochastic modelling in climate are reviewed here. One of the topics discussed is the stochastic modelling of mid-latitude low-frequency variability through a few teleconnection patterns, including the central role and physical mechanisms responsible for multiplicative noise. A new low-dimensional stochastic model is developed here, which mimics key features of atmospheric general circulation models, to test the fidelity of stochastic mode reduction procedures. The second topic discussed here is the systematic design of stochastic lattice models to capture irregular and highly intermittent features that are not resolved by a deterministic parametrization. A recent applied mathematics design principle for stochastic column modelling with intermittency is illustrated in an idealized setting for deep tropical convection; the practical effect of this stochastic model in both slowing down convectively coupled waves and increasing their fluctuations is presented here.     

MtScript: A Multi Lingual Text Editor

This paper describes the multilingual text editor MtScript developed in the framework of the MULTEXT project.MtScript enables the use of many differentwriting systems in the same document (Latin, Arabic,Cyrillic, Hebrew, Chinese, Japanese, etc.). Editingfunctions enable the insertion or deletion of textzones even if they have opposite writing directions.In addition, the languages in the text can be marked,customized keyboard input rules can be associated witheach language and different character coding systems(one or two bytes) can be combined. MtScript isbased on a portable environment (Tcl/Tk). MtScript.1.1version has been developed underUnix/X-Windows (Solaris, Linux systems) and otherversions are planned to be ported to the Windows andMacintosh environments. The current 1.1 versionpresents several limits that will be fixed in futureversions, such as the justification of bi-directionaltexts, printing support, and text import/exportsupport. Future versions will use SGML and TEI norms,which offer ways of encoding multilingual texts andare to a large extent meant for interchange.     

Dynamic Restructuring of E-Catalog Communities Based on User Interaction Patterns

Since e-catalogs are dynamic, autonomous, and heterogeneous, the integration of a potentially large number of dynamic e-catalogs is a delicate and time-consuming task. In this paper, we describe the design and the implementation of a system through which existing on-line product catalogs can be integrated, and the resulting integrated catalogs can be continuously adapted and personalized within a dynamic environment. The integration framework originates from a previous project on integration of Web data, called WebFINDIT. Using the framework, we propose a methodology for adaptation of integrated catalogs based on the observation of customers' interaction patterns.     

Classification of radar echoes with a textural–fuzzy approach: an application for the removal of ground clutter observed in Sétif (Algeria) and Bordeaux (France) sites

This work deals with the classification of radar echoes and the removal of clutter caused by the Earth’s surface. Two incoherent radar sites are considered, which are the regions of Sétif (Algeria) and Bordeaux (France) where different climates and landforms prevail. To perform this task, we used a combination of textural and fuzzy approaches. For the textural technique, we applied grey-level co-occurrence matrices that are widely used in the analysis of texture images. We have shown that among nine parameters, only energy and local homogeneity are considered to be effective in discriminating between precipitation echoes and clutter. Then, these parameters are used as inputs for the fuzzy system, while the two radar echo types are its output classes. Image processing done by using this approach has reduced ground echoes by more than 93.5% for Sétif and 92.3% for Bordeaux sites, while more than 97.6% of precipitation echoes are stored at both sites. In addition, over 96% of the anomalous propagations observed only in Bordeaux site are removed. The proposed approach gives a filtering average rate that is 94.5% higher than that obtained for the textural technique alone, which is 91.5%.     

ProcessAtlas: A scalable and extensible platform for business process analytics

In today's knowledge‐, service‐, and cloud‐based economy, an overwhelming amount of business‐related data are being generated at a fast rate daily from a wide range of sources. These data increasingly show all the typical properties of big data: wide physical distribution, diversity of formats, nonstandard data models, and independently managed and heterogeneous semantics. In this context, there is a need for new scalable and process‐aware services for querying, exploration, and analysis of process data in the enterprise because (1) process data analysis services should be capable of processing and querying large amount of data effectively and efficiently and, therefore, have to be able to scale well with the infrastructure's scale and (2) the querying services need to enable users to express their data analysis and querying needs using process‐aware abstractions rather than other lower‐level abstractions. In this paper, we introduce ProcessAtlas, ie, an extensible large‐scale process data querying and analysis platform for analyzing process data in the enterprise. The ProcessAtlas platform offers an extensible architecture by adopting a service‐based model so that new analytical services can be plugged into the platform. In ProcessAtlas, we present a domain‐specific model for representing process knowledge, ie, process‐level entities, abstractions, and the relationships among them modeled as graphs. We provide services for discovering, extracting, and analyzing process data. We provide efficient mapping and execution of process‐level queries into graph‐level queries by using scalable process query services to deal with the process data size growth and with the infrastructure's scale. We have implemented ProcessAtlas as a MapReduce‐based prototype and report on experiments performed on both synthetic and real‐world datasets.     

A Survey on Expert Recommendation in Community Question Answering

Community question answering (CQA) represents the type of Web applications where people can exchange knowledge via asking and answering questions. One significant challenge of most real-world CQA systems is the lack of effective matching between questions and the potential good answerers, which adversely affects the efficient knowledge acquisition and circulation. On the one hand, a requester might experience many low-quality answers without receiving a quality response in a brief time; on the other hand, an answerer might face numerous new questions without being able to identify the questions of interest quickly. Under this situation, expert recommendation emerges as a promising technique to address the above issues. Instead of passively waiting for users to browse and find their questions of interest, an expert recommendation method raises the attention of users to the appropriate questions actively and promptly. The past few years have witnessed considerable efforts that address the expert recommendation problem from different perspectives. These methods all have their issues that need to be resolved before the advantages of expert recommendation can be fully embraced. In this survey, we first present an overview of the research efforts and state-of-the-art techniques for the expert recommendation in CQA. We next summarize and compare the existing methods concerning their advantages and shortcomings, followed by discussing the open issues and future research directions.     

Self-adapting recovery nets for policy-driven exception handling in business processes

In this paper, we propose Self-Adapting Recovery Net (SARN), an extended Petri net model, for specifying exceptional behavior in business processes. SARN adapts the structure of the underlying Petri net at run time to handle exceptions while keeping the Petri net design easy. The proposed framework caters for the specification of high-level recovery policies that are incorporated either with a single task or a set of tasks, called a Recovery Region. These recovery policies are generic directives that model exceptions at design time together with a set of primitive operations used at run time to handle the occurrence of exceptions. We identified a set of recovery policies that are useful and commonly needed in many practical situations. A tool has been developed to illustrate the viability of the proposed exception handling technique. B. Medjahed’s work is supported by a grant from the University of Michigan’s OVPR.     

The evolution of transverse stresses in hybrid composites under hygrothermal loading

This paper presents a hygrothermal analysis of the hybrid composites under the effect of the cyclic environmental conditions in order to determine the transient transverse stresses of the [θ/−θ]_S stacking sequences. Hybrid composite is used to consider an appropriate isolation against the cyclic environmental conditions, as well as the reduction of the hygrothermal transverse stresses at both edges of the plate. To reach this aim, we used initially, the computer code W8gain developed by Springer for the determination of the moisture concentration at the end of each cycle. Thereafter, a computer code is developed to compute the hygrothermal transient stresses with implicit variation of temperature and moisture concentration after each cycle. To reduce the transverse stresses, some cases of hybrid composites are proposed. For each case, the thickness of each material constituting the hybrid plate (T300/5208 or AS/3501-5) is gradually varied, but the total thickness of our plate remains unchanged. This thickness variation enables us to find an appropriate hybrid plate which predicts an optimal reduction of hygrothermal transverse stresses; consequently an increase in durability of our hybrid plate.     

Effect of thermomechanical loads on the propagation of crack near the interface brittle/ductile

The purpose of this paper is to understand the combined effect of thermal and mechanical loading on the initiation and behaviour of sub-interface crack in the ceramic. In this study a 2D finite element model has been used to simulated mixed mode crack propagation near the bimaterial interface. The assembly ceramometalic is subjected simultaneously to thermomechanical stress field. The extent of a plastic zone deformation in the vicinity of the crack-tip has a significant influence on the rate of its propagation. The crack growth at the joint specimen under four-point bending (4PB) loading and the influence of residual stresses was also evaluated by the maximum tensile stress criterion. The J-integral at the crack tip is generally expressed by the thermomechanical local stresses. The results obtained show the effect of the temperature gradient ΔT, the size of the crack and the applied stresses on the J-integral.     

Deriving Protocol Models from Imperfect Service Conversation Logs

Understanding the business (interaction) protocol supported by a service is very important for both clients and service providers: it allows developers to know how to write clients that interact with a service, and it allows development tools and runtime middleware to deliver functionality that simplifies the service development lifecycle. It also greatly facilitates the monitoring, visualization, and aggregation of interaction data. This paper presents an approach for discovering protocol definitions from real-world service interaction logs. It first describes the challenges in protocol discovery in such a context. Then, it presents a novel discovery algorithm, which is widely applicable, robust to different kinds of imperfections often present in realworld service logs, and able to derive protocols of small sizes, also thanks to heuristics. As finding the most precise and the smallest model is algorithmically not feasible from imperfect service logs, finally, the paper presents an approach to refine the discovered protocol via user interaction, to compensate for possible imprecision introduced in the discovered model. The approach has been implemented and experimental results show its viability on both synthetic and real-world datasets.