109 research outputs found

    Application of Asynchronous Transfer Mode (Atm) technology to Picture Archiving and Communication Systems (Pacs): A survey

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    Broadband Integrated Services Digital Network (R-ISDN) provides a range of narrowband and broad-band services for voice, video, and multimedia. Asynchronous Transfer Mode (ATM) has been selected by the standards bodies as the transfer mode for implementing B-ISDN; The ability to digitize images has lead to the prospect of reducing the physical space requirements, material costs, and manual labor of traditional film handling tasks in hospitals. The system which handles the acquisition, storage, and transmission of medical images is called a Picture Archiving and Communication System (PACS). The transmission system will directly impact the speed of image transfer. Today the most common transmission means used by acquisition and display station products is Ethernet. However, when considering network media, it is important to consider what the long term needs will be. Although ATM is a new standard, it is showing signs of becoming the next logical step to meet the needs of high speed networks; This thesis is a survey on ATM, and PACS. All the concepts involved in developing a PACS are presented in an orderly manner. It presents the recent developments in ATM, its applicability to PACS and the issues to be resolved for realising an ATM-based complete PACS. This work will be useful in providing the latest information, for any future research on ATM-based networks, and PACS

    Evaluation Of Abstract Syntax Notation One For Distributed Interactive Simulation: Part 2, The Single Host And Network Models

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    Report documents the second part of an evaluation of the suitability of Abstract Syntax Notation One (ASN.1) for real-time simulation networks

    The development of a discovery and control environment for networked audio devices based on a study of current audio control protocols

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    This dissertation develops a standard device model for networked audio devices and introduces a novel discovery and control environment that uses the developed device model. The proposed standard device model is derived from a study of current audio control protocols. Both the functional capabilities and design principles of audio control protocols are investigated with an emphasis on Open Sound Control, SNMP and IEC-62379, AES64, CopperLan and UPnP. An abstract model of networked audio devices is developed, and the model is implemented in each of the previously mentioned control protocols. This model is also used within a novel discovery and control environment designed around a distributed associative memory termed an object space. This environment challenges the accepted notions of the functionality provided by a control protocol. The study concludes by comparing the salient features of the different control protocols encountered in this study. Different approaches to control protocol design are considered, and several design heuristics for control protocols are proposed

    Interfacing IEC 61850-9-2 Process Bus Data to a Simulation Environment

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    IEC 61850 – Communication and networks in substations is the standard for building communication infrastructure between the different Intelligent Electronic devices (IEDs) in the substation automation system. It consists of several parts which include Specific Communication and Service Mapping for the transmission of sampled values (defined in part 9–2 of the standard). The Sampled value communication is a high speed, time critical Ethernet based communication for the transfer of data over the network. It defines the sampling rate and time synchronization requirement of the system. The main purpose of this thesis is to extract sampled value data (four voltages, four currents) from a PCAP data file captured over the network in the ‘Sundom Smart Grid’ environment and convert the data into the format needed for analysis on PSCAD simulation tool. This thesis serves as an interface between the real Smart Grid environment and the test environment in the University of Vaasa. This thesis explains fundamental concepts that relate to IEC 61850, and the Sampled Value in particular. It describes the frame structure of sampled value and a software application has been developed based on WinPcap Application Program Interface (API) to extract the data points needed and fulfill the data format requirement of the PSCAD which is adaptable for use in MATLAB.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

    Modeling and Analysis of Automotive Cyber-physical Systems: Formal Approaches to Latency Analysis in Practice

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    Based on advances in scheduling analysis in the 1970s, a whole area of research has evolved: formal end-to-end latency analysis in real-time systems. Although multiple approaches from the scientific community have successfully been applied in industrial practice, a gap is emerging between the means provided by formally backed approaches and the need of the automotive industry where cyber-physical systems have taken over from classic embedded systems. They are accompanied by a shift to heterogeneous platforms build upon multicore architectures. Scien- tific techniques are often still based on too simple system models and estimations on important end-to-end latencies have only been tightened recently. To this end, we present an expressive system model and formally describe the problem of end-to-end latency analysis in modern automotive cyber-physical systems. Based on this we examine approaches to formally estimate tight end-to-end latencies in Chapter 4 and Chapter 5. The de- veloped approaches include a wide range of relevant systems. We show that our approach for the estimation of latencies of task chains dominates existing approaches in terms of tightness of the results. In the last chapter we make a brief digression to measurement analysis since measuring and simulation is an important part of verification in current industrial practice

    Network management and security for Unix

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    Design of an X.25 co-processor

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