Astrocomp: web technologies for high performance computing on a network of supercomputers

Astrocomp is a project developed by the INAF-Astrophysical Observatory of Catania, University of Roma La Sapienza and Enea in collaboration with Oneiros s.r.l. The project has the goal of building a web-based user-friendly interface which allows the international community to run some parallel codes on a set of high-performance computing (HPC) resources, with no need for specific knowledge about Unix and Operating Systems commands. Astrocomp provides CPU times, on parallel systems, available to the authorized user. The portal makes codes for astronomy available: FLY code, a cosmological code for studying three-dimensional collisionless self-gravitating systems with periodic boundary conditions [Becciani, Antonuccio, Comput. Phys. Comm. 136 (2001) 54]. ATD treecode, a parallel tree-code for the simulation of the dynamics of self-gravitating systems [Miocchi, Capuzzo Dolcetta, A&A 382 (2002) 758]. MARA a code for stellar light curves analysis [Rodonò et al., A&A 371 (2001) 174]. Other codes will be added to the portal in the future.     

Time-constrained services: a framework for using real-time web services in industrial automation

The use of web services in industrial automation, e.g. in fully automated production processes like car manufacturing, promises simplified interaction among the manufacturing devices due to standardized protocols and increased flexibility with respect to process implementation and reengineering. Moreover, the adoption of web services as a seamless communication backbone within the overall industrial enterprise has additional benefits, such as simplified interaction with suppliers and customers (i.e. horizontal integration) and avoidance of a break in the communication paradigm within the enterprise (i.e. vertical integration). The Time-Constrained Services (TiCS) framework is a development and execution environment that empowers automation engineers to develop, deploy, publish, compose, and invoke time-constrained web services. TiCS consists of four functional layers—tool support layer, real-time infrastructural layer, real-time service layer, and hardware layer—which contain several components to meet the demands of a web service based automation infrastructure. This article gives an overview of the TiCS framework. More precisely, the general design considerations and an architectural blueprint of the TiCS framework are presented. Subsequently, selected key components of the TiCS framework are discussed in detail: the SOAP4PLC engine for equipping programmable logic controllers with a web service interface, the SOAP4IPC engine for processing web services in real-time on industrial PCs, the WS-TemporalPolicy language for describing time constraints, and the TiCS Modeler for composing time-constrained web services into a time-constrained BPEL4WS workflow.     

Remote rendering solutions using web technologies

Remote rendering is a well-known solution to the issue of running high-performance applications requiring complex visualizations on less capable hardware/software platforms or when client access to the data source for visualization is undesired or prohibitive in terms of required bandwidth. Visualizing the output of these remote rendering applications is typically achieved through native applications or, when considering a browser environment, through plug-ins. In this paper, several solutions are presented that enable deployment of these applications on standard web browsers, even those from the pre-HTML5 era. The focus in this paper is on two specific use case scenarios, taking into account that the proposed solutions are generic enough to be applied to a range of similar applications. The technologies presented cover the entire range of sub-processes contained in a complete remote rendering solution, such as the establishment of interaction feedback channels and delivery of images as part of the rendering pipeline. Depending on factors such as application requirements, developer preferences, feature availability in the web browser or raw performance figures, a custom solution can be composed from the options discussed in this paper. This is illustrated by applying them to the two aforementioned use cases, each with specific requirements and challenges, and benchmarking these example setups in terms of performance. A comparison of advantages and disadvantages is presented to guide developers in applying the technologies under real-life conditions.     

Dependency management for digital preservation using semantic web technologies

The preservation of digital objects is a topic of prominent importance for archives and digital libraries. In this article, we focus on the problem of preserving the intelligibility of digital objects. We formalize the problem in terms of dependencies and specify a number of basic intelligibility-related tasks. In parallel, we introduce a preservation scenario as a means for clarifying the pros and cons of various representation and modeling languages that are used for the problem at hand, which reveals the benefits of adopting Semantic Web (SW) languages as a representation framework. To this end, we propose a minimal core ontology for representing intelligibility-related dependencies along with methodological hints for extending it. Finally, we report empirical and experimental results from applying the proposed approach on real data sets. It is worth mentioning that this approach can be used not only on SW-based repositories or archives, but also on those that are based on conventional approaches and languages (like EAST, DEDSL, XFDU/SAFE).     

A denotational framework for data flow analysis

Summary It is shown how to express data flow analysis in a denotational framework by means of abstract interpretation. A continuation style formulation naturally leads to the MOP (Meet Over all Paths) solution, whereas a direct style formulation leads to the MFP (Maximal Fixed Point) solution.     

A unifying passivity framework for network flow control

Network flow control regulates the traffic between sources and links based on congestion, and plays a critical role in ensuring satisfactory performance. In recent studies, global stability has been shown for several flow control schemes. By using a passivity approach, this paper presents a unifying framework which encompasses these stability results as special cases. In addition, the new approach significantly expands the current classes of stable flow controllers by augmenting the source and link update laws with passive dynamic systems. This generality offers the possibility of optimizing the controllers, for example, to improve robustness in stability and performance with respect to time delays, unmodeled flows, and capacity variation.     

RMAP: a system for visualizing data in multidimensional relevance space

exact relevance measures of the objects are not significant. We flatten the multidimensionality of the feature space into a 2D relevance map, capturing the inter-relations among the features. The prototype, extract information from the World Wide Web from query engines, automatically categorizes and clusters the information and allow the user to visualize.     

Methods and framework for visualizing higher-order finite elements

The finite element method is an important, widely used numerical technique for solving partial differential equations. This technique utilizes basis functions for approximating the geometry and the variation of the solution field over finite regions, or elements, of the domain. These basis functions are generally formed by combinations of polynomials. In the past, the polynomial order of the basis has been low-typically of linear and quadratic order. However, in recent years so-called p and hp methods have been developed, which may elevate the order of the basis to arbitrary levels with the aim of accelerating the convergence of the numerical solution. The increasing complexity of numerical basis functions poses a significant challenge to visualization systems. In the past, such systems have been loosely coupled to simulation packages, exchanging data via file transfer, and internally reimplementing the basis functions in order to perform interpolation and implement visualization algorithms. However, as the basis functions become more complex and, in some cases, proprietary in nature, it becomes increasingly difficult if not impossible to reimplement them within the visualization system. Further, most visualization systems typically process linear primitives, in part to take advantage of graphics hardware and, in part, due to the inherent simplicity of the resulting algorithms. Thus, visualization of higher-order finite elements requires tessellating the basis to produce data compatible with existing visualization systems. In this paper, we describe adaptive methods that automatically tessellate complex finite element basis functions using a flexible and extensible software framework. These methods employ a recursive, edge-based subdivision algorithm driven by a set of error metrics including geometric error, solution error, and error in image space. Further, we describe advanced pretessellation techniques that guarantees capture of the critical points of the polynomial basis. The framework has been designed using the adaptor design pattern, meaning that the visualization system need not reimplement basis functions, rather it communicates with the simulation package via simple programmatic queries. We demonstrate our method on several examples, and have implemented the framework in the open-source visualization system VTK.     

Computer animation for visualizing terrain data

Until recently, the study of terrain data gathered by satellites has meant the time-consuming analysis of hundreds of still images. An attempt to use computer animation to analyze such images more effectively is described. A simulated fly-by created by computer animation allows scientists to study many different perspective views of the data quickly. Using this technique, scientists can often detect features they might otherwise have missed     

STGMN: A gated multi-graph convolutional network framework for traffic flow prediction

Applied Intelligence - Accurate traffic flow prediction is crucial for the development of intelligent transportation. It can not only effectively avoid traffic congestion and other traffic...     

behaviorism: a framework for dynamic data visualization

While a number of information visualization software frameworks exist, creating new visualizations, especially those that involve novel visualization metaphors, interaction techniques, data analysis strategies, and specialized rendering algorithms, is still often a difficult process. To facilitate the creation of novel visualizations we present a new software framework, behaviorism, which provides a wide range of flexibility when working with dynamic information on visual, temporal, and ontological levels, but at the same time providing appropriate abstractions which allow developers to create prototypes quickly which can then easily be turned into robust systems. The core of the framework is a set of three interconnected graphs, each with associated operators: a scene graph for high-performance 3D rendering, a data graph for different layers of semantically linked heterogeneous data, and a timing graph for sophisticated control of scheduling, interaction, and animation. In particular, the timing graph provides a unified system to add behaviors to both data and visual elements, as well as to the behaviors themselves. To evaluate the framework we look briefly at three different projects all of which required novel visualizations in different domains, and all of which worked with dynamic data in different ways: an interactive ecological simulation, an information art installation, and an information visualization technique.     

ST-Hadoop: a MapReduce framework for spatio-temporal data

This paper presents ST-Hadoop; the first full-fledged open-source MapReduce framework with a native support for spatio-temporal data. ST-Hadoop is a comprehensive extension to Hadoop and SpatialHadoop that injects spatio-temporal data awareness inside each of their layers, mainly, language, indexing, and operations layers. In the language layer, ST-Hadoop provides built in spatio-temporal data types and operations. In the indexing layer, ST-Hadoop spatiotemporally loads and divides data across computation nodes in Hadoop Distributed File System in a way that mimics spatio-temporal index structures, which result in achieving orders of magnitude better performance than Hadoop and SpatialHadoop when dealing with spatio-temporal data and queries. In the operations layer, ST-Hadoop shipped with support for three fundamental spatio-temporal queries, namely, spatio-temporal range, top-k nearest neighbor, and join queries. Extensibility of ST-Hadoop allows others to extend features and operations easily using similar approaches described in the paper. Extensive experiments conducted on large-scale dataset of size 10 TB that contains over 1 Billion spatio-temporal records, to show that ST-Hadoop achieves orders of magnitude better performance than Hadoop and SpaitalHadoop when dealing with spatio-temporal data and operations. The key idea behind the performance gained in ST-Hadoop is its ability in indexing spatio-temporal data within Hadoop Distributed File System.     

A predictor-corrector technique for visualizing unsteady flow

Presents a method for visualizing unsteady flow by displaying its vortices. The vortices are identified by using a vorticity-predictor pressure-corrector scheme that follows vortex cores. The cross-sections of a vortex at each point along the core can be represented by a Fourier series. A vortex can be faithfully reconstructed from the series as a simple quadrilateral mesh, or its reconstruction can be enhanced to indicate helical motion. The mesh can reduce the representation of the flow features by a factor of 1000 or more compared with the volumetric dataset. With this amount of reduction, it is possible to implement an interactive system on a graphics workstation to permit a viewer to examine, in 3D, the evolution of the vortical structures in a complex, unsteady flow     

Format-independent and metadata-driven media resource adaptation using semantic web technologies

Adaptation of media resources is an emerging field due to the growing amount of multimedia content on the one hand and an increasing diversity in usage environments on the other hand. Furthermore, to deal with a plethora of coding and metadata formats, format-independent adaptation systems are important. In this paper, we present a new format-independent adaptation system. The proposed adaptation system relies on a model that takes into account the structural metadata, semantic metadata, and scalability information of media bitstreams. The model is implemented using the web ontology language. Existing coding formats are mapped to the structural part of the model, while existing metadata standards can be linked to the semantic part of the model. Our new adaptation technique, which is called RDF-driven content adaptation, is based on executing SPARQL Protocol and RDF Query Language queries over instances of the model for media bitstreams. Using different criteria, RDF-driven content adaptation is compared to other adaptation techniques. Next to real-time execution times, RDF-driven content adaptation provides a high abstraction level for the definition of adaptations and allows a seamless integration with existing semantic metadata standards.     

S-MRST: a novel framework for indexing uncertain data

This paper studies the problem of probabilistic range query over uncertain data. Although existing solutions could support such query, it still has space for improvement. In this paper, we firstly propose a novel index called S-MRST for indexing uncertain data. For one thing, via using an irregular shape for bounding uncertain data, it has a stronger space pruning ability. For another, by taking the gradient of probability density function into consideration, S-MRST is also powerful in terms of probability pruning ability. More important, S-MRST is a general index which could support multiple types of probabilistic queries. Theoretical analysis and extensive experimental results demonstrate the effectiveness and efficiency of the proposed index.     

Deep knowledge-aware framework for web service recommendation

The Journal of Supercomputing - Web services are products in the era of service-oriented computing and cloud computing. Considering the information overload problem arising from the task of...     

Developing a practical framework for ERP readiness assessment using fuzzy analytic network process

Previous studies report unusually high failure in enterprise resource planning (ERP) projects. Thus, it is necessary to perform an assessment at the initial stage of an ERP implementation program to identify weaknesses or problems which may lead to project failure. No definite practical solution could be found for these kinds of problems in the literature. In this paper, a new look at the determinants of a firm’s readiness to implement an ERP project is presented and using fuzzy analytic network process a practical framework is developed. The firm’s current conditions regarding ERP project can be determined and necessary changes prior to implementation of ERP system can be specified. The readiness for ERP implementation is decomposed into project management, organizational, and change management areas and the assessment factors are identified after comprehensive study of critical success factors on ERP implementation. The proposed framework is applied to a real case and the advantages are illustrated.     

基于Web数据仓库构建GSM网络优化系统

分析了移动网络优化的工作内容和工作流程,对网络中产生的海量数据进行了科学地分析与处理,提出了应用Web数据仓库和OLAP(联机分析处理)技术为手段构建GSM网络优化系统.详细说明了数据仓库的主题设计、维度和层次、度量指标和多维数据模型设计,利用SQL Server 2000实现了数据仓库的建设,并使用前端分析工具实现对数据的多维分析,从而实现为网优人员提供数据分析.