Exotica/FMDC: A workflow management system for mobile and disconnected clients

Workflow Management Systems (WFMSs) automate the execution of business processes in environments encompassing large numbers of users distributed over a wide geographic area and using heterogeneous resources. Current implementations allow the definition and controlled execution of complex and long lived business processes as the basis for an enterprise-wide collaborative system but, in most cases, the autonomy of the users is greatly restricted due to architectural and design considerations. In particular, existing systems are built around a centralized server. As a result, users need to maintain an uninterrupted connection with the server to perform the different tasks assigned to them. This is a severe restriction, especially when considering the emergence of mobile computing, and the increase in use of laptops and small computers which are connected to the network only occasionally and which will, undoubtedly, be the tool of choice for many users. This paper addresses the problem of supporting disconnected workflow clients in large workflow management systems while still preserving the correctness of the overall execution and allowing coordinated interactions between the different users regardless of their location.Recommended by: Daniel Barbara, Ravi Jain, Narayanan Krishnakumar     

Oasis: an architecture for simplified data management and disconnected operation

Oasis is an asymmetric peer-to-peer data management system tailored to the requirements of pervasive computing. Drawing upon applications from the literature, we motivate three high-level requirements: availability, manageability, and programmability. Oasis addresses these requirements by employing a peer-to-peer network of weighted replicas and performing background self-tuning. In this paper, we describe our architecture, our consistency-control mechanism, and an initial implementation. Our performance evaluation and the implementation of three applications suggest that Oasis offers good availability and performance while providing a simple API and a familiar consistency model.     

ID-Services: an RFID middleware architecture for mobile applications

The use of RFID middleware to support application development for and integration of RFID hardware into information systems has become quite common in RFID applications where reader devices remain stationary, which currently represents the largest part of all RFID applications in use. Another field for applying RFID technology which is offering a huge set of novel possibilities and applications are mobile applications, where readers are no longer fixed. In order to address the specific issues of mobile RFID-enabled applications and to support developers in rapid application development, we present ID-Services, an architecture for an RFID middleware that is designed to support mobile applications. The ID-Services approach has been used to implement MoVIS (Mobile Visitor Information System), a mobile application which allows museum visitors to request individually adapted multimedia information about exhibits in an intuitive way.     

面向集团企业的服务工作流系统架构研究

集团企业必须适应动态的业务组织方式,以响应瞬息万变的市场需求。在服务相关知识的基础上,对服务工作流进行分析和定义,并构建基于服务工作流的引擎执行框架。针对服务工作流在组合过程中的不足,对服务进行语义信息扩展,建立动态的服务调度机制。提出一种面向集团企业的服务工作流系统体系架构,为集团企业在新环境下实现按需整合业务和优化资源配置提供解决方案。最后通过具体的集团制造应用实例说明该架构的实施方法。     

A distributed control architecture for an autonomous mobile robot

This paper describes a Distributed Control Architecture for an autonomous mobile robot. We start by characterizing the Conceptual Levels into which the various problem-solving activities of a mobile robot can be classified. In sequence, we discuss a Distributed Control System that provides scheduling and coordination of multiple concurrent activities on a mobile robot. Multiple Expert Modules are responsible for the various tasks and communicate through messages and over a Blackboard. As a testbed, the architecture of a specific system for Sonar-Based Mapping and Navigation is presented, and a distributed implementation is described.     

构造可扩展工作流的语义机制模型*

为了提高复杂多样的应用环境下的工作流性能,基于Petri网构建块定义了工作流元对象模型和工作流领域本体OWLW,在传统工作流系统中引入了元对象协议,构造了一种新的面向语义的工作流模型;在此基础上讨论了一种基于多agent的软件架构来实现面向语义的工作流机制,说明了面向语义的工作流对于提高传统工作流的灵活性和可扩展性是有效的。     

基于移动代理的工作流原型研究与设计

快速发展的移动代理和网格技术给工作流提供了新的集成各种分布式资源的计算环境。传统的工作流架构有很多弱点,比如在动态环境中缺少灵活性等。提出了一个集成Web Services,网格,工作流和移动代理技术的分布式工作流架构,可以通过移动代理间的通讯来达到工作流之间协同工作,而且这个架构增强了工作流的灵活性和可靠性,以这个新的模型为基础实现了一个具体的工作流工作站,且可实现系统的安全使用。     

Conceptual framework and architecture for service mediating workflow management

This paper proposes a three-layer workflow concept framework to realize workflow enactment flexibility by dynamically binding activities to their implementations at run time. A service mediating layer is added to bridge business process definition and its implementation. Based on this framework, we propose an extended workflow management systems architecture, in which service contracting layer, service binding layer and service invocation layer are extensions to support the proposed service mediating concept. According to an enactment specification, different instances of the same activity can be bound to different services to achieve enactment flexibility. The conceptual framework and architecture together provide a comprehensive approach to flexible service enactment in B2B collaborative settings.     

DAMN: a distributed architecture for mobile navigation

An architecture is presented in which distributed task-achieving modules, or behaviours, cooperatively determine a mobile robot's path by voting for each of various possible actions. An arbiter then performs command fusion and selects that action which best satisfies the prioritized goals of the system, as expressed by these votes, without the need to average commands. Command fusion allows multiple goals and constraints to be considered simultaneously. Examples of implemented systems are given, and future research directions in command fusion are discussed.     

Beobot 2.0: Cluster architecture for mobile robotics

With the recent proliferation of robust but computationally demanding robotic algorithms, there is now a need for a mobile robot platform equipped with powerful computing facilities. In this paper, we present the design and implementation of Beobot 2.0, an affordable research‐level mobile robot equipped with a cluster of 16 2.2‐GHz processing cores. Beobot 2.0 uses compact Computer on Module (COM) processors with modest power requirements, thus accommodating various robot design constraints while still satisfying the requirement for computationally intensive algorithms. We discuss issues involved in utilizing multiple COM Express modules on a mobile platform, such as interprocessor communication, power consumption, cooling, and protection from shocks, vibrations, and other environmental hazards such as dust and moisture. We have applied Beobot 2.0 to the following computationally demanding tasks: laser‐based robot navigation, scale‐invariant feature transform (SIFT) object recognition, finding objects in a cluttered scene using visual saliency, and vision‐based localization, wherein the robot has to identify landmarks from a large database of images in a timely manner. For the last task, we tested the localization system in three large‐scale outdoor environments, which provide 3,583, 6,006, and 8,823 test frames, respectively. The localization errors for the three environments were 1.26, 2.38, and 4.08 m, respectively. The per‐frame processing times were 421.45, 794.31, and 884.74 ms respectively, representing speedup factors of 2.80, 3.00, and 3.58 when compared to a single dual‐core computer performing localization. © 2010 Wiley Periodicals, Inc.     

Cooperative localization for disconnected sensor networks and a mobile robot in friendly environments

Localization for a disconnected sensor network is highly unlikely to be achieved by its own sensor nodes, since accessibility of the information between any pair of sensor nodes cannot be guaranteed. In this paper, a mobile robot (or a mobile sensor node) is introduced to establish correlations among sparsely distributed sensor nodes which are disconnected, even isolated. The robot and the sensor network operate in a friendly manner, in which they can cooperate to perceive each other for achieving more accurate localization, rather than trying to avoid being detected by each other. The mobility of the robot allows for the stationary and internally disconnected sensor nodes to be dynamically connected and correlated. On one hand, the robot performs simultaneous localization and mapping (SLAM) based on the constrained local submap filter (CLSF). The robot creates a local submap composed of the sensor nodes present in its immediate vicinity. The locations of these nodes and the pose (position and orientation angle) of the robot are estimated within the local submap. On the other hand, the sensor nodes in the submap estimate the pose of the robot. A parallax-based robot pose estimation and tracking (PROPET) algorithm, which uses the relationship between two successive measurements of the robot's range and bearing, is proposed to continuously track the robot's pose with each sensor node. Then, tracking results of the robot's pose from different sensor nodes are fused by the Kalman filter (KF). The multi-node fusion result are further integrated with the robot's SLAM result within the local submap to achieve more accurate localization for the robot and the sensor nodes. Finally, the submap is projected and fused into the global map by the CLSF to generate localization results represented in the global frame of reference. Simulation and experimental results are presented to show the performances of the proposed method for robot-sensor network cooperative localization. Especially, if the robot (or the mobile sensor node) has the same sensing ability as the stationary sensor nodes, the localization accuracy can be significantly enhanced using the proposed method.     

An architecture for workflow scheduling under resource allocation constraints

Research on specification and scheduling of workflows has concentrated on temporal and causality constraints, which specify existence and order dependencies among tasks. However, another set of constraints that specify resource allocation is also equally important. The resources in a workflow environment are agents such as person, machine, software, etc. that execute the task. Execution of a task has a cost and this may vary depending on the resources allocated in order to execute that task. Resource allocation constraints define restrictions on how to allocate resources, and scheduling under resource allocation constraints provide proper resource allocation to tasks. In this work, we provide an architecture to specify and to schedule workflows under resource allocation constraints as well as under the temporal and causality constraints. A specification language with the ability to express resources and resource allocation constraints and a scheduler module that contains a constraint solver in order to find correct resource assignments are core and novel parts of this architecture.     

Adaptation in mobile workflow management systems

Workflow management systems (WFMS) are an emerging technology for supporting the coordinated execution of business processes by a group of users. One goal of introducing a WFMS into an enterprise is to integrate all personnel working on a business process into the system. This article describes a new approach to the integration of mobile users into a WFMS. This is of special interest because key personnel such as sales representatives and executives are often travelling and can only be integrated into the WFMS through mobile computing technologies. After introducing an architecture for mobile WFMS, we focus on the handling of one specific feature of mobile systems: the high diversity of environments in which mobile users operate. For handling this feature we have to implement adaptable software systems. In our approach, we start by introducing a formal model of mobile systems. This model offers a basis for the use of optimisation techniques to realise an adaptive mobile WFMS.     

MARS: a programmable coordination architecture for mobile agents

Mobile agents offer much promise, but agent mobility and Internet openness make coordination more difficult. Mobile Agent Reactive Spaces (MARS), a Linda-like coordination architecture with programming features, can handle a heterogeneous network while still allowing simple and flexible application design     

基于动态模型的系统架构及建模平台实现

传统的基于静态模型的系统开发方法难以解决业务规则的快速扩展及变更带来的资源浪费等问题,工作流支持对工作内容进行良好的划分,并进行具体部署。结合SOA架构的业务流程再造能力,提出一种新的以三层模型为核心的支持快速、平滑、可重用的应用系统开发架构,对流程引擎和建模平台完成详细描述和设计,完成建模平台搭建工作,并以卡银行业务为例进行了基于三层模型的建模。结果表明,该系统开发架构具有很好的业务流程再造能力,可保证业务系统的持续稳定,达到提高生产组织水平和工作效率的目的。     

A model-driven software engineering workflow and tool architecture for servitised manufacturing

Modern manufacturing businesses increasingly engage in servitisation, by offering advanced services along with physical products, and creating “product–service systems”. Information Technology infrastructures, and especially software, are a critical part of modern service provision. However, software development in this context has not been investigated and there are no development methods or tools specifically adapted to the task of creating software for servitised businesses in general, or manufacturing in particular. In this paper, we define the requirements for software engineering in servitised manufacturing. Based on these, we describe a model-driven software engineering workflow for servitised manufacturing, supporting both structural and behavioural modelling of the service system. Furthermore, we elaborate on the architecture of an appropriate model-driven Integrated Development Environment (IDE). The proposed workflow and a prototype implementation of the IDE were evaluated in a set of industrial pilots, demonstrating improved communication and collaboration between participants in the software engineering process.     

Robust architecture for distributed intelligence in an IP-based mobile wide-area surveillance system

Modern IP-based wide-area surveillance systems often build on networks of multi-modal, intelligent and mobile sensor units. Detection of complex events is performed on intelligent sensors and fusing input in the sensor units or centralized control room components. The domain of surveillance and public safety creates requirement for robustness and fault-tolerance. This article will present an automated intelligence architecture for mobile surveillance, which provides capabilities for combining on-board event detection in sensor units, centralized decision making on the server side, and automated exploitation of mobile surveillance unit positioning data. This architecture must be very reliable to provide services in the face of challenges such as natural disasters and fire, potentially damaging the infrastructure of the surveillance system. To increase its reliability and robustness, we study the introduction of a self-healing system into the architecture and examine the combined system’s operation in three case studies.     

Control architecture for mobile robot operation and navigation

This paper presents the navigation and operation system (NOS) for a multipurpose industrial autonomous mobile robot for both indoor and outdoor environments. This architecture supports task specification in terms of an event-driven state-based machine that provides high quality mission performance in uncertain environments. All processes in the NOS have been integrated in a distributed architecture designed to consider the real-time constraints of each control level of the system. Particular task models obtained from the system requirements specifications are integrated at the highest level of the architecture so that the rest of the levels remain unchanged for a wide range of industrial applications, such as transportation and operation with onboard devices.     

面向Web服务架构的协同工作流模型

为了提高分布式工作流在当前异构网络环境下的灵活性和普适性,解决分布式工作流系统中各异构子工作流系统之间的互操作问题,提出了面向Web服务架构的协同工作流模型。采用了Web服务技术的组织架构,将分布式工作流系统中的各个子工作流系统进行Web服务封装,使得各个子工作流系统能以Web服务方式向其它子工作流系统提供服务,并使用服务自适应恢复机制来保证分布式工作流系统的QoS。     

移动边缘环境下面向工作流管理的计算迁移方法

针对移动边缘环境下移动设备大量的能源消耗问题，为了优化移动设备的能源消耗，提出一种能耗感知的工作流计算迁移（EOW）方法。首先，基于排队论分析边缘设备中计算任务的平均等待时间，建立了移动设备的时间模型和能耗模型；然后，基于非支配排序算法（NSGA-Ⅲ）提出对应的计算迁移方法，对工作流的计算任务进行合理的分配，将一部分计算任务留在移动设备处理，或者迁移到边缘计算平台和远程云端，实现每个移动设备的节能目标；最后，通过CloudSim仿真平台对提出的计算迁移方法进行仿真和对比实验。实验结果表明，EOW方法能够明显地减少每个移动设备的能源消耗，同时满足每一个工作流的截止时间的要求。