416,857 research outputs found

    Fault recovery in process control

    Get PDF
    Fault Recovery in process control requires effective fault detection, diagnosis and recovery schemes, and a fault-tolPi-ant system design. Fault detection and diagnosis involves creating a realistic model of the process, and using this model to analyse for fault conditions. The fault detection principles include feature extraction and pattern recognition, and analogue value limits and rate cf change limits. Fault recovery scheme? cover the realisation of redundancy ana back-up sub-systems, and state restoration techniques in the form of complete shutdowns, backward and forward recovery to a safe operating state. System design concepts include for the development of process control systems towards *hierarchical, level based distribution of functions. The level-based discussion is used as the basis for effective fault tolerant system design. Two case studies are included to show how fault recovery schemes were effected in a single process computer and in a distributed control system. Abstrac

    Depression-related difficulties disengaging from negative faces are associated with sustained attention to negative feedback during social evaluation and predict stress recovery

    Get PDF
    The present study aimed to clarify: 1) the presence of depression-related attention bias related to a social stressor, 2) its association with depression-related attention biases as measured under standard conditions, and 3) their association with impaired stress recovery in depression. A sample of 39 participants reporting a broad range of depression levels completed a standard eye-tracking paradigm in which they had to engage/disengage their gaze with/from emotional faces. Participants then underwent a stress induction (i.e., giving a speech), in which their eye movements to false emotional feedback were measured, and stress reactivity and recovery were assessed. Depression level was associated with longer times to engage/disengage attention with/from negative faces under standard conditions and with sustained attention to negative feedback during the speech. These depression-related biases were associated and mediated the association between depression level and self-reported stress recovery, predicting lower recovery from stress after giving the speech

    What is Product-Service Systems (PSS)? A Review on PSS Researches and Relevant Policies

    Get PDF
    In order to achieve sustainable society, it is necessary to transform industrial structure to the one that does not reduce the Earth's resources. Under this circumstance, a business model of "not selling goods, but selling services" has been expected as a measure of co-existence of business and the environment. This idea, which is called as "Product-Service Systems: PSS" or "Servicizing" etc., has been studied in Europe, the United States and international organisations, and is now studied in Japan. However, the idea of PSS is still not effectively used for policy development.One of the major reasons is that PSS concept itself is under-developed. Under the unclear concept of PSS, researchers are working towards more scientific understanding while policy makers are trying to develop new policy measures, and there is confusion in those communities. In order to develop policy measures, it is necessary to make clear the position of PSS in socio-economic system. This paper overviews previous PSS researches and relevant policy measures conducted in Japan, the US and EU, and tries to grasp the context of researches and policy activities and to find out the agenda of the current status. The characteristics of PSS rest on the innovative relationship between producer and consumer. However, PSS researches are stuck at measurement of environmental loads, and relevant policies tend to be rest on the ones targeting producers. In order to get out of this situation, it is necessary to ask question what is PSS and to make it clear where PSS can be positioned in socio-economic system. PSS is important, because PSS has an element of creating sufficiency as well as eco-efficiency. It is recommended that PSS concept needs to be examined as a research effort, and environmentally sound product policy needs to be systematically organised

    Instant restore after a media failure

    Full text link
    Media failures usually leave database systems unavailable for several hours until recovery is complete, especially in applications with large devices and high transaction volume. Previous work introduced a technique called single-pass restore, which increases restore bandwidth and thus substantially decreases time to repair. Instant restore goes further as it permits read/write access to any data on a device undergoing restore--even data not yet restored--by restoring individual data segments on demand. Thus, the restore process is guided primarily by the needs of applications, and the observed mean time to repair is effectively reduced from several hours to a few seconds. This paper presents an implementation and evaluation of instant restore. The technique is incrementally implemented on a system starting with the traditional ARIES design for logging and recovery. Experiments show that the transaction latency perceived after a media failure can be cut down to less than a second and that the overhead imposed by the technique on normal processing is minimal. The net effect is that a few "nines" of availability are added to the system using simple and low-overhead software techniques
    corecore