Connectivity Infrastructure and Components for POCT Environments - Overall Infrastructure

Connectivity infrastructure, hardware and software components for point-of-care testing (POCT) environments at medium-to-large sized hospitals with expected number of POCT instruments in the order of hundreds or thousands are described. The instruments include both network-ready and non-network-ready devices. The latter are connected to the network by means of a hardware-based Instrument Network Adapter. Instrument messages are converted to standardized form and, depending on message content, are routed and delivered to appropriate destinations by a software-based Message Routing System consisting of a Message Router and a Delivery Agent. Target information systems consist of departmental and central information systems.     

An ATM-Based Connection Management Architecture for Telecommunications Services

New open service architectures are now emerging.An important part of these architectures is theconnection management function. It enables theestablishment, control and release of semipermanentconnections requested by telecommunications services suchas virtual private networks. This paper presents thespecification, design and implementation of thisconnection management function in our OAMS Open Service Architecture. The proposed architecture isdeployed over a distributed processingenvironment.     

19—CAPSTAN FRICTION FOR POLYMER MONOFILAMENTS WITH RIGIDITY

It has been shown that the conventional analysis of the capstan-friction behaviour of textile materials is innaccurate for two reasons: firstly, because it ignores the fact that such materials do not as a rule obey Amontons's Law, and. secondly, because the effect of the rigidity of the body passing round the capstan has been neglected. These effects have been analysed separately in a series of papers, but in this paper an attempt is made to take both effects into account. To do this it is necessary to obtain the relationship between the friction constants for localized- and distributed-force systems. This is done, and the resulting equations are shown to give predictions that are in agreement with experimental findings.     

An Architecture for Building Scalable, Web-Based Management Services

We present the architecture of Marvel, adistributed computing environment for building scalablemanagement services using intelligent agents and theworld-wide web. Marvel is based on an information model that generates computed views of managementinformation and a distributed computing model that makesthese views available to a variety of clientapplications. Computed views consist of monitoring,control and event views of information collected fromnetwork elements and subsequently aggregated using aseries of spatial and temporal filters. Marvel does notreplace existing element management agents but rather builds on top of them a hierarchy ofservers that generate computed views and present them toclient applications in a number of formats, includingJava-enriched web pages. It uses a distributed persistent store to reduce the cost associatedwith centralized network management systems and mobileagent technology to: (a) support thin clients byuploading the necessary code to access Marvel services; and (b) extend its functionality dynamically bydownloading code that incorporates new objects andservices. A prototype implementation in Java ispresented together with results from its firstapplication on a residential broadband access system usingcable modems.     

Analyzing Asynchronous Pipeline Schedules

Asynchronous pipelining is a form of parallelism that is useful in both distributed and shared memory systems. We show that asynchronous pipeline schedules are a generalization of both noniterative DAG (directed acyclic graph) schedules as well as simpler pipeline schedules, unifying these two types of scheduling. We generalize previous work on determining if a pipeline schedule will deadlock, and generalize Reiter's well-known formula for determining the iteration interval of a deadlock-free schedule, which is the primary measure of the execution time of a schedule. Our generalizations account for nonzero communication times (easy) and the assignment of multiple tasks to processors (nontrivial). A key component of our generalized approach to pipeline schedule analysis is the use of pipeline scheduling edges with potentially negative data dependence distances. We also discuss implementation of an asynchronous pipeline schedule at runtime; show how to efficiently simulate pipeline execution on a sequential processor; define and derive bounds on the startup time of a schedule, which is a secondary schedule performance measure; and describe a new algorithm for evaluating the iteration interval formula.     

A Flexible and Robust Peer-to-Peer Architecture with XML-Based Open Communication for Laboratory Automation

Traditional lab automation systems are highly centralized: dispatch and coordination of activities are mediated by a system controller, usually via a single, monolithic control procedure. This approach, while conceptually simple, makes changes to the system difficult; adding or removing instruments and functionality can be a daunting task. In addition, most automated systems are tied to particular development languages and protocols, making operation in heterogeneous environments (i.e., the real world) problematic, since instrument software comes in many different implementations.We present a peer-to-peer architecture for lab automation, using an XML-based communication protocol. The architecture consists of peer instrument servers, an XML communication layer, and an open control center. Each instrument peer can control, be controlled by, and communicate information to other instrument peers to fulfill the automation task. Our protocol is based on XML-RPC, a lightweight communication standard built atop HTTP.This provides an open and flexible means of peer-to-peer interfacing. The control center serves as a convenient, Web-based interface to manage the instruments. The automated procedure can be distributed across all available instrument peers (each instrument assigned a set of responsibilities); the controller implements a limited set of high-level instructions. The software components included in our prototype system are implemented in various programming languages, including Java, C/C++, Visual Basic, and LabVIEW. Our approach facilitates rapid development of laboratory automation systems.     

A Survey of Distributed Enterprise Network and Systems Management Paradigms

Since the mid 1990s, network and systemsmanagement has steadily evolved from centralizedparadigms, where the management application runs on asingle management station, to distributed paradigms,where it is distributed over many nodes. In thissurvey, our goal is to classify all these paradigms,especially the new ones, in order to help network andsystems administrators design a management application, and choose between mobile code, distributedobjects, intelligent agents, etc. Step by step, we buildan enhanced taxonomy based on four criteria: thedelegation granularity, the semantic richness of the information model, the degree of specificationof a task, and the degree of automation ofmanagement.     

Using the Concept of Intelligent Agents in Fault Management of Distributed Services

This paper proposes the application of conceptsfrom the area of intelligent agents to overcomedeficiencies of existing management architecturesregarding distribution of functionality and flexibility. Its main contribution is the proposal of amethodology for a flexible, distributed realization ofcomplex management tasks. The main application areas aredistributed services which are complex pieces of software, distributed across variousheterogeneous end systems in a network. Mostly, theyrely on the provision of other services as well. Theapproach relies on well-known concepts, such ascooperative distributed problem solving and intelligentagents, and offers a framework to combine these twoconcepts, providing a step on the roadmap to a flexible,distributed management architecture. The assessment of the approach is displayed throughout thepaper by scenarios from the area of nontime criticalfault management.     

A programming environment for real-time control of distributed multiple robotic systems

In recent years there has been great interest in robot software control architectures. However, although many interesting solutions have been presented, most of the research problems tackled related to a single robot perception, navigation and action in everyday environments. Instead, most of the practical applications of mobile robotics for service tasks in civilian environments consist of systems composed of multiple robots communicating with each other, with external sensing and actuating devices, and with external supervising workstations. RoboCup offers a great opportunity to deal with this problem. In fact the software architecture of a robot soccer player must allow successful intra-robot integration of the different activities (visual perception, path planning, strategy planning, motion control, etc.) spanning many different types of representation (raw sensor data, images, symbolic plans, etc.) and it must also guarantee successful inter-robot integration by supporting communication and cooperation. This paper focuses on this problem, presenting ETHNOS-IV - a programming environment for the design of a real-time control system composed of different robots, devices and external supervising or control stations - which has been successfully used within the Italian ART robot team in the RoboCup-99 competition. ETHNOS provides support from three main point of views which will be addressed in detail: inter-robot and intra-robot communication, realtime task scheduling, and software engineering and code reuse. Experimental results illustrating the advantages of this approach will also be presented.