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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Monitoring Device for Early Warning Signs of Operator Fatigue in Open Cut Mines

NMabbott@iinet.net.au, Nicholas Mabbott January 2005 (has links)
An investigation into technologies to detect impaired performance due to driver fatigue was undertaken. From this, a new forced-choice stimulus-reaction device was developed specifically to detect driver impairment in operators of haul trucks in open cut mines. The device was developed in conjunction with personnel from the mining industry to suit the harsh conditions of the mining environment. The technology was trialled in three open cut mines and in a driving simulator at Murdoch University in Western Australia. Data were collected on the performance of drivers and analysed to validate the technology. A significant positive correlation was found between measures of reduced operator reaction performance and measures of eye closure. It was found that the device detected few false alarms and missed few bouts of tiredness as indicated by eye closures. It is suggested that the device would be a useful tool to assist with the detection of driver fatigue in open cut mining environments. The forced-choice reaction-monitoring device was used to assess the performance of drivers in a gold mine in Kalgoorlie, Western Australia. The fly-in-fly-out haul truck drivers worked 14 consecutive 12-hour night shifts, had a day off, then worked 13 consecutive 12-hour day shifts. A total of more than 3,500 hours of real-time objective performance data were collected and analysed. The main findings were that the objective performance data showed patterns of low performance that did not fit some of the performance data that would be expected from examination of past literature. Many findings are discussed in light of these anomalies. Another important finding is that the subject’s background and sleep pathology is a possible predictor for poor performance on the forced-choice reaction task. The system was also used to measure the performance of drivers with rising blood alcohol levels in a driving simulator. Subjects drank vodka with a mixer while driving for two hours starting at both 20:00 hrs and 22:00 hrs, with a week in between the two trials. The fatigue monitor detected reaction times slower than 3 SD of baseline performance at low levels of BAC. Performance at 22:00 hrs was marginally more impaired than performance at 20:00 hrs. Drivers at low BAC levels tended to compensate easier on the reaction task at 20:00 hrs compared to at 22:00 hrs. The ARRB fatigue monitor shows good capacity to detect poor performance due to low and medium measures of BAC. The research undertaken within this thesis has provided data that challenges contemporary research that generally suggests that time on task is one of the largest influences of fatigue at work. It appears that both circadian influences and individual lifestyle habits will have an equal or greater impact on fatigue risk at work.
2

System for Predictive Life cycle Management of Buildings and Infrastructures

Hallberg, Daniel January 2009 (has links)
The Life Cycle Management System (LMS) aims at supporting decision-makers and engineers in their efforts to achieve a more optimised proactive life cycle design and maintenance management strategy. LMS is an open and integrative system, which has to be adapted and developed in order to meet the needs and requirements of users. This process should be geared to and governed by the clients. The Architecture, Engineering, Construction and Facility Management (AEC/FM) sector includes all varieties of clients and stakeholders, all of them having different qualifications, possibilities and requirements for implementing, or increasing the feature of predictive maintenance management and optimised proactive strategies. The possibilities of adopting predictive maintenance management are dependent on the availability of performance-over-time and service life forecasting models and methods. The relevance of these models and methods depends on the required level of detailing. Furthermore, the use of the models and methods depends on the availability of reliable input data, such as material data and environmental exposure/in-use condition data. The thesis aims at analysing the possibilities of implementing predictivity in different fields of applications and at evaluating relevant tools facilitating management of information associated with predictive maintenance management systems. The thesis includes studies of three different clients and fields of application; Swedish Road Administration – management of bridges, Locum AB – management of hospital buildings, and Gävle Energi AB – management of district heating distribution systems. While the Swedish Road Administration is responsible to ensure an economically efficient, sustainable transport system for the society throughout the country, Locum AB and Gävle Energi AB compete on an "open" market. The Swedish Road Administration have gathered information about their bridges since 1944, for what reason their bridge management system includes a large amount of valuable data for performance-over- time analyses and service life forecasting. Locum AB has recently begun to systematically gather condition data, why the amount of data is limited. However, since the performance of buildings generally is well known, it is assumed that possibilities of implementing predictive maintenance management tools are rather good. Since district heating pipes are buried into the ground, it is difficult to assess the condition. Therefore, data for service life estimation rely mainly on damage reports. Environmental exposure data on macro or meso level can be obtained from meteorological and environmental institutes, thus making it possible to apply available dose-response and damage functions. Environmental exposure data on a micro level are lacking. Guidelines, methods and tools for environmental measuring and modelling on a micro level are therefore strongly needed. Efficient management of information plays an important role in predictive life cycle management systems. The ongoing development and implementation of open Building Information Model (BIM) tools in the AEC/FM sector is a promising progress of making the information management more cost effective and valuable, especially when open BIM solutions being fully integrated into the AEC/FM business. Geographical Information Systems (GIS) are tools for efficient handling of spatial positioned information. GIS provide possibilities of processing and presenting, e.g., environmental exposure data and environmental risk factors. / QC 20100716
3

UML basierte Zeitmodellierung für eingebettete Echtzeitsysteme

Dimitrow, Wassil 30 June 2006 (has links) (PDF)
Die Arbeit stellt eine Methodik zur modellbasierten Spezifikation und Analyse des Zeitverhaltens eines Systems mit UML (Unified Modeling Language) vor. Durch Stereotypen und Tags des Profile for Schedulability, Performance and Time (SPT) werden die erforderlichen Eigenschaften beschrieben. Als Eingangsinformation dient das UML-Modell des zu entwerfenden Systems. Die Analyse liefert eine Aussage über die Einhaltung von Zeitconstraints als Ganzes. Bei Verletzungen erfolgen elementbezogene Kommentare. Damit wird mit standardisierten Mitteln eine Analyse des zeitbezogenen Systemverhaltens vor den Partitionierungsentscheidungen möglich. Die Modellierung erfolgt im Tool Real-time Studio (RtS) der Firma Artisan Software Tools, Inc.
4

Exploiting Flow Relationships to Improve the Performance of Distributed Applications

Shang, Hao 06 April 2006 (has links)
Application performance continues to be an issue even with increased Internet bandwidth. There are many reasons for poor application performance including unpredictable network conditions, long round trip times, inadequate transmission mechanisms, or less than optimal application designs. In this work, we propose to exploit flow relationships as a general means to improve Internet application performance. We define a relationship to exist between two flows if the flows exhibit temporal proximity within the same scope, where a scope may either be between two hosts or between two clusters of hosts. Temporal proximity can either be in parallel or near-term sequential. As part of this work, we first observe that flow relationships are plentiful and they can be exploited to improve application performance. Second, we establish a framework on possible techniques to exploit flow relationships. In this framework, we summarize the improvements that can be brought by these techniques into several types and also use a taxonomy to break Internet applications into different categories based on their traffic characteristics and performance concerns. This approach allows us to investigate how a technique helps a group of applications rather than a particular one. Finally, we investigate several specific techniques under the framework and use them to illustrate how flow relationships are exploited to achieve a variety of improvements. We propose and evaluate a list of techniques including piggybacking related domain names, data piggybacking, enhanced TCP ACKs, packet aggregation, and critical packet piggybacking. We use them as examples to show how particular flow relationships can be used to improve applications in different ways such as reducing round trips, providing better quality of information, reducing the total number of packets, and avoiding timeouts. Results show that the technique of piggybacking related domain names can significantly reduce local cache misses and also reduce the same number of domain name messages. The data piggybacking technique can provide packet-efficient throughput in the reverse direction of a TCP connection without sacrificing forward throughput. The enhanced ACK approach provides more detailed and complete information about the state of the forward direction that could be used by a TCP implementation to obtain better throughput under different network conditions. Results for packet aggregation show only a marginal gain of packet savings due to the current traffic patterns. Finally, results for critical packet piggybacking demonstrate a big potential in using related flows to send duplicate copies to protect performance-critical packets from loss.
5

UML basierte Zeitmodellierung für eingebettete Echtzeitsysteme

Dimitrow, Wassil 30 June 2006 (has links)
Die Arbeit stellt eine Methodik zur modellbasierten Spezifikation und Analyse des Zeitverhaltens eines Systems mit UML (Unified Modeling Language) vor. Durch Stereotypen und Tags des Profile for Schedulability, Performance and Time (SPT) werden die erforderlichen Eigenschaften beschrieben. Als Eingangsinformation dient das UML-Modell des zu entwerfenden Systems. Die Analyse liefert eine Aussage über die Einhaltung von Zeitconstraints als Ganzes. Bei Verletzungen erfolgen elementbezogene Kommentare. Damit wird mit standardisierten Mitteln eine Analyse des zeitbezogenen Systemverhaltens vor den Partitionierungsentscheidungen möglich. Die Modellierung erfolgt im Tool Real-time Studio (RtS) der Firma Artisan Software Tools, Inc.
6

Power efficient and power attacks resistant system design and analysis using aggressive scaling with timing speculation

Rathnala, Prasanthi January 2017 (has links)
Growing usage of smart and portable electronic devices demands embedded system designers to provide solutions with better performance and reduced power consumption. Due to the new development of IoT and embedded systems usage, not only power and performance of these devices but also security of them is becoming an important design constraint. In this work, a novel aggressive scaling based on timing speculation is proposed to overcome the drawbacks of traditional DVFS and provide security from power analysis attacks at the same time. Dynamic voltage and frequency scaling (DVFS) is proven to be the most suitable technique for power efficiency in processor designs. Due to its promising benefits, the technique is still getting researchers attention to trade off power and performance of modern processor designs. The issues of traditional DVFS are: 1) Due to its pre-calculated operating points, the system is not able to suit to modern process variations. 2) Since Process Voltage and Temperature (PVT) variations are not considered, large timing margins are added to guarantee a safe operation in the presence of variations. The research work presented here addresses these issues by employing aggressive scaling mechanisms to achieve more power savings with increased performance. This approach uses in-situ timing error monitoring and recovering mechanisms to reduce extra timing margins and to account for process variations. A novel timing error detection and correction mechanism, to achieve more power savings or high performance, is presented. This novel technique has also been shown to improve security of processors against differential power analysis attacks technique. Differential power analysis attacks can extract secret information from embedded systems without knowing much details about the internal architecture of the device. Simulated and experimental data show that the novel technique can provide a performance improvement of 24% or power savings of 44% while occupying less area and power overhead. Overall, the proposed aggressive scaling technique provides an improvement in power consumption and performance while increasing the security of processors from power analysis attacks.
7

Vytipování genetické predispozice ovlivňující sportovní výkon se zaměřením na anaerobní aktivitu kosterní svalové činnosti / Identifying a genetic predisposition affecting sports performance, focusing on anaerobic activity of skeletal muscle activity

Balkó, Iva January 2017 (has links)
Title Identifying of genetic predisposition affecting sports performance focusing on anaerobic activity of skeletal muscle activity Problem Inborn predispositions of every individual are mainly influenced by the inherited genetic information in their DNA with the addition of external environmental factors. Based on the high variability of the inborn predictions in the form of phenotypic differences in the anatomy or physiology of an individual, it can be deduced on the connection between genetics and a specific sport talent. According to current scientific knowledge, anaerobic performance of the skeletal muscle tissue seems to be more genetically influenced. Anatomic and functional properties of the skeletal muscle are mainly influenced by genes, which have effect on the muscle fibre structure, blood storage, metabolism, neurotransmission, and muscle regeneration, etc. Fencing is a complex sport discipline where predispositions to speed and dynamic force play a key role. The sport performance in fencing, regardless of the type of weapon, is directly dependent on the interactions between the reaction of the fencer to the surrounding stimuli (visual, tactile), accuracy, tactical and technical skills, level of anticipation and overall physical a psychological readiness of the fencer. This work is...
8

Vytipování genetické predispozice ovlivňující sportovní výkon se zaměřením na anaerobní aktivitu kosterní svalové činnosti / Identifying a genetic predisposition affecting sports performance, focusing on anaerobic activity of skeletal muscle activity

Balkó, Iva January 2017 (has links)
Title Identifying of genetic predisposition affecting sports performance focusing on anaerobic activity of skeletal muscle activity Problem Inborn predispositions of every individual are mainly influenced by the inherited genetic information in their DNA with the addition of external environmental factors. Based on the high variability of the inborn predictions in the form of phenotypic differences in the anatomy or physiology of an individual, it can be deduced on the connection between genetics and a specific sport talent. According to current scientific knowledge, anaerobic performance of the skeletal muscle tissue seems to be more genetically influenced. Anatomic and functional properties of the skeletal muscle are mainly influenced by genes, which have effect on the muscle fibre structure, blood storage, metabolism, neurotransmission, and muscle regeneration, etc. Fencing is a complex sport discipline where predispositions to speed and dynamic force play a key role. The sport performance in fencing, regardless of the type of weapon, is directly dependent on the interactions between the reaction of the fencer to the surrounding stimuli (visual, tactile), accuracy, tactical and technical skills, level of anticipation and overall physical a psychological readiness of the fencer. This work is...
9

200 MBPS TO 1 GBPS DATA ACQUISITION & CAPTURE USING RACEWAY

O’Connell, Richard 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / For many years VME has been the platform of choice for high-performance, real-time data acquisition systems. VME’s longevity has been made possible in part by timely enhancements which have expanded system bandwidth and allowed systems to support ever increasing throughput. One of the most recent ANSI-standard extensions of the VME specification defines RACEway, a system of dynamically switched, 160 Mbyte/second board-to-board interconnects. In typical systems RACEway increases the internal bandwidth of a VME system by an order of magnitude. Since this bandwidth is both scaleable and deterministic, it is particularly well suited to high-performance, real-time systems. The potential of RACEway for very high-performance (200 Mbps to 1 Gbps) real-time systems has been recognized by both the VME industry and a growing number of system integrators. This recognition has yielded many new RACEway-ready VME products from more than a dozen vendors. In fact many significant real-time data acquisition systems that consist entirely of commercial-off-the-shelf (COTS) RACEway products are being developed and fielded today. This paper provides an overview of RACEway technology, identifies the types of RACEway equipment currently available, discusses how RACEway can be applied in high-performance data acquisition systems, and briefly describes two systems that acquiring and capturing real-time data streams at rates from 200 Mbps to 1 Gbps using RACEway.

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