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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.
11

Reliability evaluation of the two bus interface controllers in the Darlington simulator

Le, Dong Khanh 01 January 2010 (has links)
The Darlington simulator is now two decades old and, in common with any nuclear simulator of a similar age, suffers the problem of parts aging and obsolescence. In the past, replacement parts were available from the original vendor, Canadian Aviation Electronics. This is no longer an option, as the vendor has shown no interest in continuing to supply spare parts. Over the years, the Simulator Services Department has undertaken several projects. These projects were carried out aiming at different goals: (i) solving the problem with spare parts scarcity, (ii) modifying the simulator to adapt it to increased usage requirements, or (iii) upgrading the simulator to improve its reliability. One such project is the re-design of the Bus Interface Controller used in the I/O system of the simulator. The Bus Interface Controller is probably the most important piece of hardware in the whole I/O system. As such, it is important that reliability evaluation of the new design be carried out. Reliability has become increasingly important in the design of engineering systems. The key factor driving this is the demand of the customers [6]. The Darlington simulator usage time has always been consistently high, sometimes reaching the level of continuous use during some periods of the past years. The increase usage requirement creates a demand for higher availability, while the allocated maintenance time has been cut back substantially. The only way to meet this demand is to have better designs, where reliability consideration and evaluation are incorporated into the design cycle. Following this design methodology, during the early design cycle of the new Ethernet Bus Interface Controller, an analysis was done to evaluate its reliability. This report presents the details of the analysis and compares the reliability of the new design with the existing one. / UOIT
12

Design and Implementation of a simulator in support of WirelessHART-based control systems development

Shah, Kunjesh January 2009 (has links)
In Industrial automated process plants, the wired communication system is being replacing by the newly developed wireless communication system as it is easy to use, scalable, simple, reliable, and provide more flexibility for installing and operating process automation equipments. The WirelessHART network is becoming popular for wireless communication system in industrial automation plant system. However this network works on the TDMA bus arbitration technique. Each network device needs to be scheduled by the user (network operator) to allow the communications between the field devices and a gateway. Some companies like DUST have already manufactured the device hardware to implement this wireless communication system on industrial automation plant. A Simulator of this system is necessary to imitate the system performance on computer using the computer programming to simulate the result of each timeslot. Purpose of designing this simulator is to use the timeslots more efficiently and to offer collision free communications between network devices. It is may be time taking process to build the simulator in the beginning but at the end it provides cost and time effective solutions.  This report describes how the simulator has been designed for the system at various phases e.g. architecture, design, and implementation etc.
13

Simulating peer-to-peer networks

Ting, Nyik San 25 August 2006 (has links)
Peer-to-Peer (P2P) systems are emerging as a new form of distributed computing with a strong emphasis on self-organization, decentralization, and autonomy of the participating nodes. The characteristics of self-organization, autonomy, and decentralization allow for highly adaptive, robust, and scalable networks, making P2P an increasingly interesting way to design distributed systems. <p>Since the deployment of P2P systems involves significant resources, e.g., hundreds of hosts and users, it is often not possible to run realistic tests prior to the rollout of the system. Consequently, simulation is the only realistic approach for testing or predicting the behavior of large P2P networks. However, the majority of the existing simulators tend to provide limited flexibility in simulating the details of the users, application, protocol, and physical network. <p>In this research, the impact of user behavior, protocol, and physical network characteristic on the overall P2P system are being observed. The aim is to investigate the importance of simulating P2P systems in such detail.
14

The use of a rainfall simulator for brush control research on the Edwards Plateau region of Texas

Porter, Shane Courtney 12 April 2006 (has links)
The thicketization of the semi-arid region of the United States has resulted in a dramatic change allowing invasive woody species to dominate the landscape with an unknown impact to the water budget. This landscape transformation has created a need to study the hydrology of the region and in particular the effects of increased brush on the water cycle. To study the effects of invasive brush on the water budget, a portable abovecanopy rainfall simulator was developed for plot scale hydrologic research. The rainfall simulator was tested at various field locations, including within the Edwards Plateau, to replicate natural rainfall events on typical hillslope-scale plots. The rainfall simulator was used to quantify aspects of the water budget for a 7 m by 14 m research plot on the Edwards Plateau in Texas. Three rainfall simulation dates were selected for detailed hydrologic analysis. Overall, throughfall accounted for 74% of the water applied to the plot, while 26% of applied water was in the form of stemflow. Lateral subsurface flow represented 33% of the water measured leaving the research plot. A notable result of rainfall simulations was extensive lateral subsurface flow and no surface runoff. The rainfall simulator has proven to be a cost-effective and efficient research tool for replicating natural rainfall in arid and semi-arid environments.
15

Foam drilling simulator

Paknejad, Amir Saman 25 April 2007 (has links)
Although the use of compressible drilling fluids is experiencing growth, the flow behavior and stability properties of drilling foams are more complicated than those of conventional fluids. In contrast with conventional mud, the physical properties of foam change along the wellbore. Foam physical and thermal properties are strongly affected by pressure and temperature. Many problems associated with field applications still exist, and a precise characterization of the rheological properties of these complex systems needs to be performed. The accurate determination of the foam properties in circulating wells helps to achieve better estimation of foam rheology and pressure. A computer code is developed to process the data and closely simulate the pressure during drilling a well. The model also offers a detailed discussion of many aspects of foam drilling operations and enables the user to generate many comparative graphs and tables. The effects of some important parameters such as: back-pressure, rate of penetration, cuttings concentration, cuttings size, and formation water influx on pressure, injection rate, and velocity are presented in tabular and graphical form. A discretized heat transfer model is formulated with an energy balance on a control volume in the flowing fluid. The finite difference model (FDM) is used to write the governing heat transfer equations in discretized form. A detailed discussion on the determination of heat transfer coefficients and the solution approach is presented. Additional research is required to analyze the foam heat transfer coefficient and thermal conductivity.
16

Design and Implementation of a simulator in support of WirelessHART-based control systems development

Shah, Kunjesh January 2009 (has links)
<p>In Industrial automated process plants, the wired communication system is being replacing by the newly developed wireless communication system as it is easy to use, scalable, simple, reliable, and provide more flexibility for installing and operating process automation equipments. The <strong>WirelessHART</strong> network is becoming popular for wireless communication system in industrial automation plant system. However this network works on the TDMA bus arbitration technique. Each network device needs to be scheduled by the user (network operator) to allow the communications between the field devices and a gateway. Some companies like DUST have already manufactured the device hardware to implement this wireless communication system on industrial automation plant. A Simulator of this system is necessary to imitate the system performance on computer using the computer programming to simulate the result of each timeslot. Purpose of designing this simulator is to use the timeslots more efficiently and to offer collision free communications between network devices. It is may be time taking process to build the simulator in the beginning but at the end it provides cost and time effective solutions. </p><p>This report describes how the simulator has been designed for the system at various phases e.g. architecture, design, and implementation etc.</p>
17

Beitrag zur Entwicklung komplexer medizinischer Trainings-Simulatoren am Beispiel der Geburtshilfe

Obst, Tobias January 2009 (has links)
Zugl.: München, Techn. Univ., Diss., 2009
18

Simulating Dialysis : Concept Evaluation of a PC Training Simulator for Nurses

Holm, Malin January 2013 (has links)
Nurses at a haemodialysis clinic are required to handle complex technological equipment in a stressful environment, with the patients’ lives at risk. A training needs analysis (TNA) that was made at Karolinska University Hospital Huddinge in 2010 identifies the nurses’ need to practice alarm situations in the safe environment of a computer-based training simulator. This project builds on the conclusions of the TNA and the aim is to evaluate the concept of a training simulator by developing and evaluating a prototype program. The simulation model used is the prototype is based on a problem solving approach with virtual patient scenarios. During the entire development process continuous input has been gathered from nurses who work with dialysis. The project was completed by structured user test focusing on evaluating the usability and realism of the prototype. The conclusion of the project is that nurses working with dialysis need to practice alarm situations and that a training simulator could meet this need. The report is written in English.
19

An evaluation of the forces applied by physiotherapists during manipulation of the spine

McCrea, Jonathan T. January 2000 (has links)
No description available.
20

SPAcENoCs : A Scalable Platform for FPGA Accelerated Emulator of NoCs

Chen, Guangming 03 October 2013 (has links)
The majority of modern high performance computing systems have employed on-chip multi-processors. As the number of on-chip cores soars, the traditional non- scalable communication infrastructures, commonly observed as shared buses or cross- bars, no longer accommodate the increasing communication demand by the modern multi-core chips. The newly emerging Network-On-Chip (NoC) interconnection scheme has provided a scalable, robust and power-efficient solution that also satisfies the requirements on both bandwidth and latency. A tool that enables swift exploration of the vast NoC design space is then in great demand to meet the stiff time pressure over research and development. Based on the work of AcENoCs, an NoC simulator designed on the basis of software and hardware codesign seeking for a large simulatable network size, the SPAcENoCs (Scalable Platform for FPGA Accelerated Emulator of NoCs) employs the Time-Division Multiplexing (TDM) techniques to implement a simulator for even larger NoCs without sacrificing simulation speed and cycle accuracy which have been highlighted in the work of AcENoCs. This paper will focus on re-organization of the given software/hardware codesigned frameworks so that the TDM techniques may be applied. While both frameworks require re-design, the major efforts involve re- construction of the hardware framework by adding data buffers and affiliated logic to ensure the data generated in different time divisions are properly preserved and trans- mitted. Various design tradeoffs over hardware budget and simulation performance are also discussed and attempted in this paper. During the development process, the techniques of device virtualization and generic programming are introduced to overcome the verification challenges that are commonly seen in software/hardware codesigned systems. The synthesis results of various design options suggested that the simulation of a 9 × 6 network, more than twice the size of largest applicable size in AcENoCs, can be accommodated by the device. Based on the simulation result of AcENoCs, the estimated speedup of SPAcENoCs over software simulator for the 9 × 6 NoC is around 28-94X, twice the one achieved by AcENoCs in a smaller network.

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