A QoS-driven approach for cloud computing addressing attributes of performance and security

In recent years, cloud computing has been one of the most widely discussed topics in the field of Information Technology. Owing to the popularity of services offered by cloud environments, several critical aspects of security have aroused interest in the academic and industrial world, where there is a concern to provide efficient mechanisms to combat a wide range of threats. As is well known, the application of security techniques and methodologies has a direct influence on the performance of the system, since security and performance are two quantities that are inversely proportional. This means that if the service providers fail to manage their computing infrastructure efficiently, the demand for services may not be met with the quality required by clients, including security and performance requirements, and the computational resources may be used inefficiently. The aim of this paper was to define QoS-driven approaches for cloud environments on the basis of the results of a performance evaluation of a service in which different security mechanisms are employed. These mechanisms impose additional overhead on the performance of the service, and to counter this, an attempt was made to change computational resources dynamically and on-the-fly. On the basis of the results, it could be shown that in a cloud environment, it is possible to maintain the performance of the service even with the overhead imposed by the security mechanisms, through an alteration in the virtualized computational resources. However, this change in the amount of resources had a direct effect on the response variables.     

A survey of methods for the extraction of information from Web resources

Earlier surveys of research in the field of extracting structured data from Web-pages are analyzed, and a scheme for the classification of the available approaches based on the extent of their application is proposed.     

Consecutive multiline addressing: A scheme for addressing PMOLEDs

Abstract— Consecutive multiline addressing (CMLA) has been developed to increase a PMOLED display's lifetime, resolution, and power efficiency. Mathematically, it decomposes an image matrix into a set of multiline matrices and a residual single‐line matrix. The decomposition is lossless and implemented by a combinatorial algorithm allowing small chip size for the logic and high processing speed, e.g., for video applications. The additional memory needed for CMLA is just a fraction of the graphic data memory (GDRAM). The printed‐circuit‐board (PCB) prototype with a field programmable gate array (FPGA) proves that the CMLA produces images of the same visual quality as the conventional single‐line addressing (SLA), while the power efficiency is substantially higher.     

Interchanging lexical resources on the Semantic Web

Lexica and terminology databases play a vital role in many NLP applications, but currently most such resources are published in application-specific formats, or with custom access interfaces, leading to the problem that much of this data is in “data silos” and hence difficult to access. The Semantic Web and in particular the Linked Data initiative provide effective solutions to this problem, as well as possibilities for data reuse by inter-lexicon linking, and incorporation of data categories by dereferencable URIs. The Semantic Web focuses on the use of ontologies to describe semantics on the Web, but currently there is no standard for providing complex lexical information for such ontologies and for describing the relationship between the lexicon and the ontology. We present our model, lemon, which aims to address these gaps while building on existing work, in particular the Lexical Markup Framework, the ISOcat Data Category Registry, SKOS (Simple Knowledge Organization System) and the LexInfo and LIR ontology-lexicon models.     

Detecting trends on the Web: A multidisciplinary approach

This paper introduces a framework for trend modeling and detection on the Web through the usage of Opinion Mining and Topic Modeling tools based on the fusion of freely available information. This framework consists of a four step model that runs periodically: crawl a set of predefined sources of documents; search for potential sources and extract topics from the retrieved documents; retrieve opinionated documents from social networks for each detected topic and extract sentiment information from them. The proposed framework was applied to a set of 20 sources of documents over a period of 8 months. After the analysis period and that the proposed experiments were run, an F-Measure of 0.56 was obtained for the detection of significant events, implying that the proposed framework is a feasible model of how trends could be represented through the analysis of documents freely available on the Web.     

Making Web services tradable: A policy-based approach for specifying preferences on Web service properties

In service-oriented architectures, applications are developed by incorporating services which are often provided by different organizations. Since a service might be offered under different configurations by various different organizations, sophisticated service selection and negotiation algorithms are required. Policies capture the conditions under which services are offered or requested and thereby constrain the negotiation space. However, current policy languages are ill-suited to realize beneficial trade-offs within a negotiation, since they support only Boolean decisions and cannot capture all relevant service information.Therefore, we present a novel policy language in this work that provides two main contributions: (i) we enable the specification of constraints on functional as well as non-functional properties of Web services. The functional properties include data objects and the behaviour, whereas the non-functional properties include QoS attributes. (ii) Given such constraints, we show how the concept of utility function policies can be used to define cardinal preferences over functional as well as non-functional properties. This is required to rank Web service offers, define their prices, and consequently to realize automated negotiations between service providers and requesters.     

基于本体的Web资源个性化推荐算法

为提高Web资源推荐的准确度,提出基于本体的Web资源个性化推荐算法(BO-RM)。设计Web资源主题抽取算法和相似性度量方法,利用本体语义推理机制实现资源聚类,在推荐过程中通过实时分析用户浏览行为捕获用户个性化偏好的变化,动态实时推荐内容。与基于情境的协同过滤算法（CFR-RM）和基于模型的个性化预测算法（BM-RM）进行对比,结果显示BO-RM的时间开销相对稳定,在平均排序倒数(MRR)和平均准确率(MAP)上均取得了较好的效果。实验结果表明:BO-RM离线完成海量Web资源的分析聚类,有效提高了运行效率,实用性比较强;BO-RM实时捕捉用户兴趣变化,动态更新推荐列表,更加贴近用户的真实需求。     

基于向量空间的Web服务发现模糊方法

Web服务已逐渐发展成为重要的分布式计算范式。在综合分析了现有的Web服务描述文档的基础上,提出了一种基于模糊集的服务特征项集选取算法以及Web服务向量空间的生成方法。利用生成的向量空间,对Web服务进行模糊聚类。基于此,文中给出了向量空间中进行Web服务发现的模糊方法。所提出的方法只需利用现有的Web服务描述信息,保证了服务发现的有效性。     

A bootstrapping approach to entity linkage on the Semantic Web

In the Big Data era, ever-increasing RDF data have reached a scale in billions of entities and brought challenges to the problem of entity linkage on the Semantic Web. Although millions of entities, typically denoted by URIs, have been explicitly linked with owl:sameAs, potentially coreferent ones are still numerous. Existing automatic approaches address this problem mainly from two perspectives: one is via equivalence reasoning, which infers semantically coreferent entities but probably misses many potentials; the other is by similarity computation between property-values of entities, which is not always accurate and do not scale well. In this paper, we introduce a bootstrapping approach by leveraging these two kinds of methods for entity linkage. Given an entity, our approach first infers a set of semantically coreferent entities. Then, it iteratively expands this entity set using discriminative property-value pairs. The discriminability is learned with a statistical measure, which does not only identify important property-values in the entity set, but also takes matched properties into account. Frequent property combinations are also mined to improve linkage accuracy. We develop an online entity linkage search engine, and show its superior precision and recall by comparing with representative approaches on a large-scale and two benchmark datasets.     

Open annotations on multimedia Web resources

Many Web portals allow users to associate additional information with existing multimedia resources such as images, audio, and video. However, these portals are usually closed systems and user-generated annotations are almost always kept locked up and remain inaccessible to the Web of Data. We believe that an important step to take is the integration of multimedia annotations and the Linked Data principles. We present the current state of the Open Annotation Model, explain our design rationale, and describe how the model can represent user annotations on multimedia Web resources. Applying this model in Web portals and devices, which support user annotations, should allow clients to easily publish and consume, thus exchange annotations on multimedia Web resources via common Web standards.     

分布式资源的Web服务组合机制

单个资源的服务往往不能满足任务需求,而多个服务的组合却可以派生出新的服务。为此,模拟迷宫求解的思路,设计了一套通用服务组合算法,将分布式资源提供的可用服务看作为迷宫中的条条道路,而将服务组合方案看作为连接迷宫入口和出口的一条通路,通过服务与服务、服务与需求之间的功能性关联,自动生成满足任务需求的服务组合方案。模拟实验验证了方法的有效性。     

A reverse engineering approach for automatic annotation of Web pages

The Semantic Web is gaining increasing interest to fulfill the need of sharing, retrieving, and reusing information. Since Web pages are designed to be read by people, not machines, searching and reusing information on the Web is a difficult task without human participation. To this aim adding semantics (i.e meaning) to a Web page would help the machines to understand Web contents and better support the Web search process. One of the latest developments in this field is Google’s Rich Snippets, a service for Web site owners to add semantics to their Web pages. In this paper we provide a structured approach to automatically annotate a Web page with Rich Snippets RDFa tags. Exploiting a data reverse engineering method, combined with several heuristics, and a named entity recognition technique, our method is capable of recognizing and annotating a subset of Rich Snippets’ vocabulary, i.e., all the attributes of its Review concept, and the names of the Person and Organization concepts. We implemented tools and services and evaluated the accuracy of the approach on real E-commerce Web sites.     

A policy-based approach for strong mobility of composed Web services

This paper presents a flexible, portable, and transparent solution for strong mobility of composed Web services relying on policy-oriented techniques. The proposed approach provides a checkpoint solution based on automatic code instrumentation using correct source code transformation rules. This checkpoint technique permits to save the execution state of a mobile orchestration process as well as the execution states of its orchestrated partners. Thus, after migration, only non-executed codes will be resumed. In addition, our approach enables dynamic adaptation of the employed checkpointing and mobility techniques using aspects. For that, we use policies allowing dynamic selection of the used checkpointing and mobility techniques according to the execution context. Moreover, the proposed solution includes a module allowing the determination of the checkpointing interval satisfying QoS requirements. Experimentations show the efficiency of the proposed solution.     

Organising access to Evidence-Based Medicine resources on the Web

The continuing education is a challenge for health care professionals, considering the growing amount and variable quality of information in this field. In this context, we developed a method allowing clinicians to have a centralised access to the best current medical evidence supporting medical decision-making. Relevant data has been gathered according to the rules stated for Evidence-Based Medicine (EBM) and organised in a free-of-charge Web site, created by using common software applications. The general aim of our study was to encourage individual practice of EBM by providing tutorials as well as a selection of free access tools for searching medical information on the Web. In addition to the education part, we provided clinicians, through a Web interface, with up-to-date, accurate and quality data obtained from heterogeneous sources and presented in a full text format when available. The developed methodology has been applied to human prostate cancer. URL address: http://www.ebm.lib.ulg.ac.be/prostate/index.htm.     

A patterned approach for linking knowledge-based systems to external resources

Knowledge-based systems (KBSs) have been developed and used in industry and government as assistance systems, voting partner systems, and embedded applications. As web-based systems change the face of software implementations, these closed, internal KBSs need to be integrated into multicomponent applications that provide updated and extensible services. Therefore, KBSs must be adapted to an environment in which data and control are exchanged with external processes and resources; complementing other participating systems or using them to refine its own results. This integration can be a daunting task. If improperly done, it can result in an inefficient and unmanageable composite application. One approach to simplifying this task is the use of architectural patterns for integration. These patterns are assembled from functional entities that resolve component interoperability conflicts. In this paper, we describe an architectural pattern called the Knowledge Director pattern, which directs the integration of a closed KBS into a broader application environment.     

An automated approach for merging business process fragments

In the field of business process management, adopting efficient building strategies can improve the quality of companies’ business processes. The reuse of existing business processes or even fragments of them is a practical approach to build complete business processes or coarser-grained process fragments. In the present paper, we deal with the merge of a set of business process fragments for the construction of new complete processes. Our merge mechanism relies on a particular path matrix, that we call gateway path matrix. We use gateway path matrices to represent business process fragments to systematically compose shared components with individual ones. Moreover, our approach ensures that the resulting business process fragments subsume the behavior of initial ones and allows for adding new execution scenarios while controlling undesirable ones. In fact, we detect newly generated behaviors, and alert process designers of undesirable ones through behavioral constraints. We provide extensive experimental results derived from an implementation of our approach applied on a well-known industrial library of business process fragments.     

A business model for deploying Web services:A data-centric approach based on factual dependencies

The standards XML, SOAP, WSDL and UDDI allow (i) services to be accessed and executed via the Web; and (ii) a loose coupling of these services. Thanks to these standards, Web services technology is becoming not only a de facto integration standard, but also a de facto Internet standard instance of the SOA architecture. However, the deployment of such a technology is still hindered by some technical as well as methodological issues. This paper proposes a business model with multiple interfaced abstraction levels as a framework to methodologically deploy Web services technology with respect to SOA architecture. The attributes describing the business objects and coordination artifacts as described in the highest abstraction level of the business model, i.e. the universe of discourse, are aggregated according to a time/space constraint called factual dependency. Each aggregation of factually dependent attributes is validated with regard to an actual business event. The aggregation is then interfaced to lead to a well-specified Web service. The resulting comprehensive set of consistent Web services are then registered in a public or a private UDDI to be discovered and invoked by any business process. The proposed Web services generation process aims at unlocking and turning informational assets into actions. It differs from the current IT perspective approaches that generate Web services directly from redundant and inconsistent elements in the enterprise information systems.