A scalable framework for mobile real-time group communication services

A scalable framework for mobile real-time group communication services is developed in this paper. Examples for possible applications of this framework are mobile social networks, mobile conference calls, mobile instant messaging services, and mobile multi-player on-line games. A key requirement for enabling a real-time group communication service is the tight constraint imposed on the call delivery delay. Since establishing such communication service for a group of independent mobile users under a tight delay constraint is NP-hard, a two-tier architecture is proposed, that can meet the delay constraint imposed by the real-time service requirement for many independent mobile clients in a scalable manner. This goal is achieved by two dimensional partition of the space, first by organization and then geographically. Both the time and memory complexity associated with the location management of N mobile users are O(N) for the location management provided by the proposed framework, while a distributed scheme requires O(N²) for both time and memory complexity.     

Chameleon – a group communication framework for smartphones

This paper reports about our experience in designing and developing Chameleon, a highly portable and adaptable group communication framework for smartphones. Chameleon owes its level of portability to several design choices, including the following: (i) a layered architecture, where the headers of each layer have a standard XML‐based format, enabling automatic, error‐resistant generation of efficient serialization code in any platform; (ii) reliance only on the J2ME library, which serves as least common denominator for Java dialects and facilitates automatic translation to.NET; (iii) having flexible membership models; and (iv) supporting multiple concurrent protocol stacks.Through a single codebase, Chameleon is currently available as an open‐source project for J2ME, J2SE, Android,.NET CF, and.NET. Chameleon is easily extendable and is bundled with tools, configurations, and third‐party code tuned in a way that lifts some of the burden normally associated with multiplatform development for smartphones. Both the header generation from XML and automatic translation to.NET features of Chameleon are readily available to any application that is based on it. Chameleon's threading model separates between execution of internal layers and application's code and by that protects one from the other. As we describe in the paper, it simplifies layers' development and allows the protocol stack to easily block application calls when this is required by internal algorithms. Additionally, this model simplifies testing, and an extensive testing framework is supplied along with Chameleon, which is also usable for testing of application‐specific layers. Copyright © 2014 John Wiley & Sons, Ltd.     

An architecture for Java-based real-time distributed visualization

In this paper, we present a Java-based software architecture for real-time visualization that utilizes a cluster of conventional PCs to generate high-quality interactive graphics. Normally, a large multiprocessor computer would be needed for interactive visualization tasks requiring more processing power than a single PC can provide. By using clusters of PCs, enormous cost savings can be realized, and proprietary "high-end" hardware is no longer necessary for these tasks. Our architecture minimizes the amount of synchronization needed between PCs, resulting in excellent scalability. It provides a modular framework that can accommodate a wide variety of rendering algorithms and data formats, provided that the rendering algorithms can generate pixels individually and the data is duplicated on each PC. Demonstration modules that implement ray tracing, fractal rendering, and volume rendering algorithms were developed to evaluate the architecture. Results are encouraging-using 15 PCs connected to a standard 100 Megabit/s Ethernet network, the system can interactively render simple to moderately complex data sets at modest resolution. Excellent scalability is achieved; however, our tests were limited to a cluster of 15 PCs. Results also demonstrate that Java is a viable platform for real-time distributed visualization.     

ConClass: a framework for real-time distributed knowledge-basedprocessing

We have developed a problem-solving framework, called ConClass, that is capable of classifying continuous real-time problems dynamically and concurrently on a distributed system. ConClass provides an efficient development environment for describing and decomposing a classification problem and synthesizing solutions. In ConClass, decomposed concurrent subproblems specified by the application developer effectively correspond to the actual distributed hardware elements. This scheme is useful for designing and implementing efficient distributed processing, making it easier to anticipate and evaluate system behavior. The ConClass system provides an object replication feature that prevents any particular object from being overloaded. In order to deal with an indeterminate amount of problem data, ConClass dynamically creates object networks that justify hypothesized solutions, and thus achieves a dynamic load distribution. A number of efficient execution mechanisms that manage a variety of asynchronous aspects of distributed processing have been implemented without using schedulers or synchronization schemes that are liable to develop bottlenecks. We have confirmed the efficiency of parallel distributed processing and load balancing of ConClass with an experimental application     

Web上基于Java的数据库应用研究

该文分析了传统的Ｗｅｂ上基于ＣＧＩ的数据库解决方案存在的问题,针对存在的问题提出了一种基于Ｊａｖａ的新的数据库解决方案,并实现了一个Ｗｅｂ在线购物系统。     

IDSRadar: a real-time visualization framework for IDS alerts

Intrusion Detection Systems(IDS) is an automated cyber security monitoring system to sense malicious activities.Unfortunately,IDS often generates both a considerable number of alerts and false positives in IDS logs.Information visualization allows users to discover and analyze large amounts of information through visual exploration and interaction efficiently.Even with the aid of visualization,identifying the attack patterns and recognizing the false positives from a great number of alerts are still challenges.In this paper,a novel visualization framework,IDSRadar,is proposed for IDS alerts,which can monitor the network and perceive the overall view of the security situation by using radial graph in real-time.IDSRadar utilizes five categories of entropy functions to quantitatively analyze the irregular behavioral patterns,and synthesizes interactions,filtering and drill-down to detect the potential intrusions.In conclusion,IDSRadar is used to analyze the mini-challenges of the VAST challenge 2011 and 2012.     

FRWSC: a framework for robust Web service composition

The deployment of Web services in a highly dynamic environment brings about a number of research challenges. In dynamic Web services composition, failures and changes to atomic services cannot be detected before invocation. Hence, the failure or even the change in an atomic service may lead to the overall failure of the composite service. In addition, SOAP error code is not sufficient for the client to analyze the failure reason and handle it. In this work, we introduce a framework to deal with unexpected failures during runtime composition. The proposed framework is built on top of composite services stack as an interface between the composite service and its external service partners. The evaluation results show that by using the proposed framework, it is possible to avoid composite service failures that are caused by changes or failures in atomic services.     

BASAR: a framework for integrating agents in the World Wide Web

At GMD's Human Computer Interaction Research Division, we are working on a system called BASAR (Building Agents Supporting Adaptive Retrieval). BASAR, a Smalltalk-based program that runs on Unix platforms, involves intelligent agents that actively support construction and management of a user's personal information space. Possible agent tasks include supporting navigation and browsing; simplifying information retrieval; sorting, organizing, and indexing user-jobs; and filtering information from large databases. BASAR's interface is based on the concept of indirect management. That is, computer agents support human users in a cooperative process where both agents and users can initiate communication, monitor events, and perform tasks     

Java-based framework for processing and displaying short-echo-time magnetic resonance spectroscopy signals

Magnetic resonance spectroscopy (MRS) can be used to determine in a non-invasive way the concentrations of certain chemical substances, also called metabolites. The spectra of MRS signals contain peaks that correspond to the metabolites of interest. Short-echo-time signals are characterized by heavily overlapping metabolite peaks and require sophisticated processing methods. To be useful in a clinical environment tools are needed that can process those signals in an accurate and fast way. Therefore, we developed novel processing methods and we designed a freely available and open-source framework (http://www.esat.kuleuven.ac.be/sista/members/biomed) in which the processing methods can be integrated. The framework has a set of abstract classes, called hot spots, and its goal is to provide a general structure and determine the control flow of the program. It provides building blocks or components in order to help developers with integrating their methods in the framework via a plug-in system. The framework is designed with the unified modeling language (UML) and implemented in Java. When a developer implements the framework he gets an application that acts like a simple and user-friendly graphical user interface (GUI) for processing MRS data. This article describes in detail the structure and implementation of the framework and the integration of our processing methods in it.     

TDCS: a new scheduling framework for real-time multimedia OS

ABSTRACT

The emerging real-time hyper-physical system (CPS), such as autonomous vehicle and live interactive media application, requires time deterministic behaviour. This is challenging to achieve by using the traditional general purpose operating system (GPOS). This paper presents a new design of the real-time operating system (OS) scheduling mechanism called ‘time deterministic cyclic scheduling’ (TDCS) mainly for live multimedia tasks processing. This new scheduler shares a similar philosophy as classic cyclic execution but with flexibility and dynamic configuration. This hybrid design is based on both time-reserved based cyclic execution and priority-based pre-emptive scheduling for mixed criticality applications. The simulation results show that this scheduling scheme can achieve predictable timing behaviour of task delay and jitter under high CPU utilisation. This shows that the proposed scheme is promising for low latency high-performance multimedia censoring tasks that occur in a periodic manner.     

Virtual Visual Servoing: a framework for real-time augmented reality

This paper presents a framework to achieve real‐time augmented reality applications. We propose a framework based on the visual servoing approach well known in robotics. We consider pose or viewpoint computation as a similar problem to visual servoing. It allows one to take advantage of all the research that has been carried out in this domain in the past. The proposed method features simplicity, accuracy, efficiency, and scalability wrt. to the camera model as well as wrt. the features extracted from the image. We illustrate the efficiency of our approach on augmented reality applications with various real image sequences.     

The Web: a communication medium for health care

The World Wide Web is a relatively inexpensive and pervasive communication channel that could feasibly let doctors and nurses continuously monitor the progress of thousands of patients throughout the world. Reducing medical research costs and enabling communication between patients and care providers is especially important for rare diseases because they often have limited research funds and a relatively small number of patients in each country. I describe four case studies that show how the Internet can streamline the clinical trial process and monitor patients remotely, rather than act merely as a search engine. The Web could reduce health-care costs and decrease the heath-care systems' response time in high-risk situations.     

网络信息检索中相关反馈技术的Java实现

介绍了相关反馈技术的基本思想,设计了网络信息检索中相关反馈系统的功能与结构,探索如何在现有的公共网络搜索引擎基础上,利用Java语言实现具有相关反馈功能的搜索引擎接口.     

基于时间触发机制的实时通信架构研究与设计

为解决多核架构分布式系统的硬实时问题,在Barrelfish基础框架上设计并实现一个时间触发实时操作系统的消息通信服务,使其可应用于SMP系统、NoC网络和其它支持时间触发的网络中。为解决Multikernel无法使用并行多线程的缺点,提出一种基于Barrelfish的动态SMP子系统,减少整个系统内独立分区的数目,降低系统设计和调度的难度,使实时应用可在Multikernel架构上充分利用硬件并行能力,设计相应的消息调度表生成算法。实验结果表明了该通信框架的可行性。     

rIBIS: a real-time group hypertext system

This paper describes rIBIS, a real-time group hypertext system, which allows a distributed set of users to simultaneously browse and edit multiple views of a hypertext network. At any time, rIBIS users can switch back and forth between tightly coupled and loosely coupled interaction modes. The paper describes the high-level architecture and user interface of the rIBIS system. Early use of the rIBIS system by a software system design team suggests that users' acceptance increases as they continue to use the tool. We conclude that rIBIS effectiveness is affected by both people and implementation issues.     

Common: A framework for the functional enhancement of a simple real-time system

Computer control of experiments may often be organized as a set of cooperating processes in a single user environment, A framework for the functional enhancement of a simple foreground/background operating system is given. Implementation features such as transparent, stream-oriented input/output, additional software concurrency, and the use of micro-computer satellites for instrument control are described. Synchronization and scheduling is discussed in terms of condition-event nets. Finally, the conditions necessary for implementing COMMON are stated and it is shown that they are fulfilled in our implementation.     

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.     

Mobile Web services: a new agent-based framework

Mobile devices and server applications often run on different platforms, which can make integration problematic. Web services might offer a solution, but they typically include XML protocols that are too "heavy" for mobile devices. In this article, we describe agent-based mobile services framework. It uses wireless portal networks and eliminates XML processing on mobile clients. It also offers dynamic service selection and rapid application development and deployment for Web service providers.     

Garden: a real-time processing framework for continuous top-k trajectory similarity search

Knowledge and Information Systems - Continuous top-k trajectory similarity Search (CkSearch) is now commonly required in real-time large-scale trajectory analysis, enabling the distributed stream...     

RFES: a real-time fire evacuation system for Mobile Web3D

Frontiers of Information Technology & Electronic Engineering - There are many bottlenecks that limit the computing power of the Mobile Web3D and they need to be solved before implementing a...