物件導向軟體之架構(Object-Oriented Software Construction)探討

The convergence of Web technology, wireless networks, and portable client devices provides new design opportunities for computer/communications systems. In the HP Labs' Cooltown project we have been exploring these opportunities through an infrastructure to support Web presence for people, places and things. We put Web servers into things like printers and put information into Web servers about things like artwork; we group physically related things into places embodied in Web servers. Using URLs for addressing, physical URL beaconing and sensing of URLs for discovery, and localized Web servers for directories, we can create a location-aware but ubiquitous system to support nomadic users. On top of this infrastructure we can leverage Internet connectivity to support communications services. Web presence bridges the World Wide Web and the physical world we inhabit, providing a model for supporting nomadic users without a central control point.

http://www.hpl.hp.com/techreports/2001/HPL-2001-279.pdf

People, places, things: Web presence for the real world

Methods and apparatus associated with a plurality of serial devices designed to communicate with a bus master in either a daisy chain or a normal configuration are provided. One method includes the step of serially providing a command sequence having a channel identifier to a given device of a plurality of daisy chained devices. The channel identifier is modified as it passes thru each daisy chained device. A specific device is identified or enabled when the channel identifier it receives matches a pre-determined value.

Serial device daisy chaining method and apparatus

The emergence of massive datasets in a clinical setting presents both challenges and opportunities in data storage and analysis. This so called “big data” challenges traditional analytic tools and will increasingly require novel solutions adapted from other fields. Advances in information and communication technology present the most viable solutions to big data analysis in terms of efficiency and scalability. It is vital those big data solutions are multithreaded and that data access approaches be precisely tailored to large volumes of semi-structured/unstructured data. The MapReduce programming framework uses two tasks common in functional programming: Map and Reduce. MapReduce is a new parallel processing framework and Hadoop is its open-source implementation on a single computing node or on clusters. Compared with existing parallel processing paradigms (e.g. grid computing and graphical processing unit (GPU)), MapReduce and Hadoop have two advantages: 1) fault-tolerant storage resulting in reliable data processing by replicating the computing tasks, and cloning the data chunks on different computing nodes across the computing cluster; 2) high-throughput data processing via a batch processing framework and the Hadoop distributed file system (HDFS). Data are stored in the HDFS and made available to the slave nodes for computation. In this paper, we review the existing applications of the MapReduce programming framework and its implementation platform Hadoop in clinical big data and related medical health informatics fields. The usage of MapReduce and Hadoop on a distributed system represents a significant advance in clinical big data processing and utilization, and opens up new opportunities in the emerging era of big data analytics. The objective of this paper is to summarize the state-of-the-art efforts in clinical big data analytics and highlight what might be needed to enhance the outcomes of clinical big data analytics tools. This paper is concluded by summarizing the potential usage of the MapReduce programming framework and Hadoop platform to process huge volumes of clinical data in medical health informatics related fields.

/pdf/applications-of-the-mapreduce-programming-framework-to-4lm0m4mle7.pdf

Applications of the MapReduce programming framework to clinical big data analysis: current landscape and future trends.

We propose a new, media-independent protocol for including program timing, structure and identity information in Internet media streams. The protocol uses signaling messages called cues to indicate events whose timing is significant to receivers, such as the start or stop time of a media program. We describe the implementation and operation of a prototype Internet radio station which transmits program cues in audio broadcasts using the Real-Time Transport Protocol. A collection of simple yet powerful stream processing applications we implemented demonstrate how application creation is greatly eased when media streams are enriched with program cues.

http://www.hpl.hp.com/techreports/2000/HPL-2000-173.pdf

Enhancing Internet streaming media with cueing protocols

Distributed Systems: Concepts and Design (4th Edition) (International Computer Science)

The use of multimedia in distributed systems has begun to include such complex and mission-critical domains as digital television production, ‘video-ondemand’ services, medical and security systems. These applications impose more stringent requirements on the support mechanisms provided by underlying networks and operating systems than most currently deployed continuous media applications. This paper describes the Djinn multimedia programming framework, which is designed to support the construction and dynamic reconfiguration of distributed multimedia applications. We motivate the benefits of a runtime model of the quality of service and other characteristics of multimedia applications, and demonstrate a generic algorithm for scheduling dynamic reconfigurations that maintains QoS guarantees. QoS characteristics are modelled as piecewise-linear or quadratic relations, which are solved using standard constraint programming techniques. During reconfigurations, updates to active components are scheduled so as to maintain temporal constraints on the media streams. We illustrate our approach using experimental results from a real-world application domain.

/pdf/a-qos-support-framework-for-dynamically-reconfigurable-4n2b3iuw3g.pdf

A QoS support framework for dynamically reconfigurable multimedia applications

This paper reports on a study of clinicians who care for diabetic patients, and on the design of an application to support their work. The clinicians' long-term activity is rooted in a series of private sessions with the patient. Clinicians exchange information but the timeliness, specificity and other salient features of the communication are often unsatisfactory. Problems consequently arise such as the omission or duplication of tests. We describe a conceptual framework to account for the effectiveness of knowledge-sharing in groups such as these, and use it to motivate an application aimed at improving the clinicians' levels of communication and coordination.

Supporting the shared care of diabetic patients

Distributed multimedia systems are potentially subject to frequent and ongoing evolution of application structures. In such systems it is often unacceptable for reconfigurations to fail or to only partially succeed. This paper describes the reconfiguration architecture of the DJINN multimedia programming framework. We introduce the concept of multimedia transactions for structuring changes into atomic units that preserve application consistency and extend these with the smoothness condition to maintain temporal as well as data integrity across reconfigurations. We present a technique for scheduling configuration changes that trades off the perceived level of smoothness against the available resources and the desired timeliness of the reconfiguration.

/pdf/dynamically-reconfiguring-multimedia-components-a-model-1upmr4kgle.pdf

Dynamically reconfiguring multimedia components: a model-based approach

This paper reports on the Mushroom project. The project is developing a software framework for collaborative working and user interaction on the Internet. The paper illustrates some of the required features in the context of an application scenario and outlines those aspects of the Mushroom system architecture that support the sharing of information. The project's motivation is to address the problems of coordinated user interaction, distribution and privacy. Mrooms are interactive environments for groups of collaborating users. They provide a shared space in which users are aware of one another while working on shared objects. Their boundaries provide a triggering mechanism for consistency and privacy checks. In contrast to other systems with room-based metaphors, Mushroom focuses on a scalable and flexible system architecture using replicated state, group communication and event-based updates.

Tim Kindberg

Papers

Distributed Systems: Concepts and Design (4th Edition) (International Computer Science)

A QoS support framework for dynamically reconfigurable multimedia applications

Supporting the shared care of diabetic patients

Dynamically reconfiguring multimedia components: a model-based approach

Sharing objects over the Internet: the Mushroom approach