• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 120
  • 36
  • 29
  • 13
  • 7
  • 7
  • 5
  • 5
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 262
  • 262
  • 92
  • 60
  • 57
  • 42
  • 40
  • 37
  • 35
  • 34
  • 32
  • 28
  • 27
  • 25
  • 23
  • 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.
61

On the Performance of the Solaris Operating System under the Xen Security-enabled Hypervisor

Bavelski, Alexei January 2007 (has links)
<p>This thesis presents an evaluation of the Solaris version of the Xen virtual machine monitor and a comparison of its performance to the performance of Solaris Containers under similar conditions. Xen is a virtual machine monitor, based on the paravirtualization approach, which provides an instruction set different to the native machine environment and therefore requires modifications to the guest operating systems. Solaris Zones is an operating system-level virtualization technology that is part of the Solaris OS. Furthermore, we provide a basic performance evaluation of the security modules for Xen and Zones, known as sHype and Solaris Trusted Extensions, respectively.</p><p>We evaluate the control domain (know as Domain-0) and the user domain performance as the number of user domains increases. Testing Domain-0 with an increasing number of user domains allows us to evaluate how much overhead virtual operating systems impose in the idle state and how their number influences the overall system performance. Testing one user domain and increasing the number of idle domains allows us to evaluate how the number of domains influences operating system performance. Testing concurrently loaded increasing numbers of user domains we investigate total system efficiency and load balancing dependent on the number of running systems.</p><p>System performance was limited by CPU, memory, and hard drive characteristics. In the case of CPU-bound tests Xen exhibited performance close to the performance of Zones and to the native Solaris performance, loosing 2-3% due to the virtualization overhead. In case of memory-bound and hard drive-bound tests Xen showed 5 to 10 times worse performance.</p>
62

THE EVALUATION OF TINYOS WITH WIRELESS SENSOR NODE OPERATING SYSTEMS

Famoriyo, Olusola January 2007 (has links)
<p>Wireless Sensor nodes fall somewhere in between the single application devices that do</p><p>not need an operating system, and the more capable, general purpose devices with the</p><p>resources to run a traditional embedded operating system. Sensor node operating system</p><p>such as TinyOS, Contiki, MantisOS and SOS which is discussed in this paper exhibit</p><p>characteristics of both traditional embedded systems and general-purpose operating systems</p><p>providing a limited number of common services for application developers linking</p><p>software and hardware.</p><p>These common services typically include platform support, hardware management of sensors,</p><p>radios, and I/O buses and application construction etc. They also provide services</p><p>needed by applications which include task coordination, power management, adaptation</p><p>to resource constraints, and networking. The evaluation was concentrated on TinyOS</p><p>including an analysis on version 1.x and 2.x resource management and flexibility and its</p><p>operation with the other wireless sensor node operating systems.</p>
63

Design and development of a novel omni-directional platform

Bemis, Steven 01 August 2009 (has links)
This thesis presents the design and development of a unique omni-directional platform known as the Omnibot which was built in the Mechatronic and Robotic Systems Laboratory at UOIT. The Omnibot's layout is novel because its drive axes do not intersect with the geometric center of the body, which is typical for omni-directional platforms using segmented omni-directional wheels. This design enables the center of mass to be lower in the design and increases the stability. A suspension system was designed for each of the four wheels to limit vibrations and to ensure contact between the wheels and operating surface. The Omnibot was built to modularly support many systems, including a robot arm, without altering the mechanical design of the frame. Two control modes were developed: local and global. Commands to drive the Omnibot can be received from either a joystick that can be directly interfaced with the controller or with commands that are sent from other systems that are either on or o of the Omnibot. Both control modes require encoder feedback to ensure commanded velocities are being executed as specified. Global control requires feedback from an indoor localization system to determine the Omnibot's pose. Early implementation of the localization system is discussed. An open source robotics software, known as Robot Operating System (ROS) was selected for implementation of the Omnibot systems. ROS serves as a middleware which allows components, such as the localization system and remote desktop, to communicate with each other through a decoupled messaging system. ROS is modular and exible, allowing for easy adaptation of future components. Test results of the Omnibot in operation are presented.
64

Simultaneous Localization And Mapping Using a Kinect In a Sparse Feature Indoor Environment / Simultan lokalisering och kartering med hjälp av en Kinect i en inomhusmiljö med få landmärken

Hjelmare, Fredrik, Rangsjö, Jonas January 2012 (has links)
Localization and mapping are two of the most central tasks when it comes to autonomous robots. It has often been performed using expensive, accurate sensors but the fast development of consumer electronics has made similar sensors available at a more affordable price. In this master thesis a TurtleBot, robot and a Microsoft Kinect, camera are used to perform Simultaneous Localization And Mapping, SLAM. The thesis presents modifications to an already existing open source SLAM algorithm. The original algorithm, based on visual odometry, is extended so that it can also make use of measurements from wheel odometry and asingle axis gyro. Measurements are fused using an Extended Kalman Filter, EKF, operating in a multirate fashion. Both the SLAM algorithm and the EKF are implemented in C++ using the framework Robot Operating System, ROS. The implementation is evaluated on two different data sets. One set is recorded in an ordinary office room which constitutes an environment with many landmarks. The other set is recorded in a conference room where one of the walls is flat and white. This gives a partially sparse featured environment. The result by providing additional sensor information is a more robust algorithm. Periods without credible visual information does not make the algorithm lose its track and the algorithm can thus be used in a larger variety of environments including such where the possibility to extract landmarks is low. The result also shows that the visual odometry can cancel out drift introduced by wheel odometry and gyro sensors.
65

A PC-based data acquisition system for sub-atomic physics measurements

Chabot, Daron 23 July 2008
Modern particle physics measurements are heavily dependent upon automated data acquisition systems (DAQ) to collect and process experiment-generated information. One research group from the University of Saskatchewan utilizes a DAQ known as the Lucid data acquisition and analysis system. This thesis examines the project undertaken to upgrade the hardware and software components of Lucid. To establish the effectiveness of the system upgrades, several performance metrics were obtained including the system's dead time and input/output bandwidth.<p>Hardware upgrades to Lucid consisted of replacing its aging digitization equipment with modern, faster-converting Versa-Module Eurobus (VME) technology and replacing the instrumentation processing platform with common, PC hardware. The new processor platform is coupled to the instrumentation modules via a fiber-optic bridging-device, the sis1100/3100 from Struck Innovative Systems.<p>The software systems of Lucid were also modified to follow suit with the new hardware. Originally constructed to utilize a proprietary real-time operating system, the data acquisition application was ported to run under the freely available Real-Time Executive for Multiprocessor Systems (RTEMS). The device driver software provided with sis1100/3100 interface also had to be ported for use under the RTEMS-based system. <p>Performance measurements of the upgraded DAQ indicate that the dead time has been reduced from being on the order of milliseconds to being on the order of several tens of microseconds. This increased capability means that Lucid's users may acquire significantly more data in a shorter period of time, thereby decreasing both the statistical uncertainties and data collection duration associated with a given experiment.
66

Intelligent Voice Assistant

Song, Qunying, Shen, Hui January 2012 (has links)
This project includes an implementation of an intelligent voice recognition assistant for Android where functionality on current existing applications on other platforms is compared. Until this day, there has not been any good alternative for Android, so this project aims to implement a voice assistant for the Android platform while describing the difficulties and challenges that lies in this task.
67

Simultaneous Localization And Mapping Using a Kinect in a Sparse Feature Indoor Environment / Simultan lokalisering och kartering med hjälp av en Kinect i en inomhusmiljö med få landmärken

Hjelmare, Fredrik, Rangsjö, Jonas January 2012 (has links)
Localization and mapping are two of the most central tasks when it comes toautonomous robots. It has often been performed using expensive, accurate sensorsbut the fast development of consumer electronics has made similar sensorsavailable at a more affordable price. In this master thesis a TurtleBot\texttrademark\, robot and a MicrosoftKinect\texttrademark\, camera are used to perform Simultaneous Localization AndMapping, SLAM. The thesis presents modifications to an already existing opensource SLAM algorithm. The original algorithm, based on visual odometry, isextended so that it can also make use of measurements from wheel odometry and asingle axis gyro. Measurements are fused using an Extended Kalman Filter,EKF, operating in a multirate fashion. Both the SLAM algorithm and the EKF areimplemented in C++ using the framework Robot Operating System, ROS. The implementation is evaluated on two different data sets. One set isrecorded in an ordinary office room which constitutes an environment with manylandmarks. The other set is recorded in a conference room where one of the wallsis flat and white. This gives a partially sparse featured environment. The result by providing additional sensor information is a more robust algorithm.Periods without credible visual information does not make the algorithm lose itstrack and the algorithm can thus be used in a larger variety of environmentsincluding such where the possibility to extract landmarks is low. The resultalso shows that the visual odometry can cancel out drift introduced bywheel odometry and gyro sensors.
68

A PC-based data acquisition system for sub-atomic physics measurements

Chabot, Daron 23 July 2008 (has links)
Modern particle physics measurements are heavily dependent upon automated data acquisition systems (DAQ) to collect and process experiment-generated information. One research group from the University of Saskatchewan utilizes a DAQ known as the Lucid data acquisition and analysis system. This thesis examines the project undertaken to upgrade the hardware and software components of Lucid. To establish the effectiveness of the system upgrades, several performance metrics were obtained including the system's dead time and input/output bandwidth.<p>Hardware upgrades to Lucid consisted of replacing its aging digitization equipment with modern, faster-converting Versa-Module Eurobus (VME) technology and replacing the instrumentation processing platform with common, PC hardware. The new processor platform is coupled to the instrumentation modules via a fiber-optic bridging-device, the sis1100/3100 from Struck Innovative Systems.<p>The software systems of Lucid were also modified to follow suit with the new hardware. Originally constructed to utilize a proprietary real-time operating system, the data acquisition application was ported to run under the freely available Real-Time Executive for Multiprocessor Systems (RTEMS). The device driver software provided with sis1100/3100 interface also had to be ported for use under the RTEMS-based system. <p>Performance measurements of the upgraded DAQ indicate that the dead time has been reduced from being on the order of milliseconds to being on the order of several tens of microseconds. This increased capability means that Lucid's users may acquire significantly more data in a shorter period of time, thereby decreasing both the statistical uncertainties and data collection duration associated with a given experiment.
69

The Research of Brand Image and Involvement Affect Brand Royalty in Smart Phone Market

Kao, Wei-Chun 15 July 2011 (has links)
The global shipments of smartphones will be more than four hundred fifty million, and it will overtake handset and become the mainstream in 2011. The fact is that there are more and more choices for customers to choose. It not only many brands, but also varieties of operating systems are provided with consumers.In this trend, is brand image still important factor that contributes to the consumers choosing the smartphones? For customers having had smartphones, how the brand image affects their loyalty? Therefore, this study attempts to find out the linear relationship between brand image and brand loyalty, In addition, it takes involvement and the operating systems into consideration. The research also intends to focus on whether the effects of the involvement adjust this or not and look for a difference of linear relationship between the two operating systems-android and ios. The scope of this research includes the customers owning smartphones in Taiwan. Moreover, the method of the study is sending on-line and paper questionnaires at the same time, and the number of the valid questionnaires is 261.In this study, brand image are divided into three perspectives by factorial analysis, functional benefits, symbolic benefits, experiential benefits. Brand loyalty consists of behavioral loyalty and attitudinal loyalty. The involvement is composed of importance, symbolic value, and risk.The research uses regression analysis to verify the linear relationship between brand image and brand loyalty. Furthermore, put brand image, brand loyalty, involvement into the regression analysis, and through multiple stepwise regression analysis to find out the factors which contribute to linear relationship. The result reveals that there is a linear relationship between the brand image and brand loyalty. In addition, linear relationship between different operating systems is also different, and especially the functional brand influences significantly on brand loyalty.
70

The Linux Porting and Integration Verification of An Academic 32-bit Processor

Chen, Chien-Chih 10 September 2012 (has links)
For improving the performance and application of microprocessor, it is necessary to integrate pipelined core, exception control unit, cache unit and memory management unit (MMU). The operating system is an effective way for microprocessor integration verification. However, it is not a feasible debugging methodology to detect the exact design bug while operating system booting crash. We found the main execution features of operating system are the data transfer and exception handling. We propose an integration verification methodology based on these execution features. The methodology is to verify concurrent cache transfer operation, consecutive cache transfer operation, external interrupt exception handling, page fault exception handling and multiple interrupt exception handling for microprocessor integration. We utilize ARM7-Like developed by our laboratory to do the experiment. It is effective to detect the design bugs in RTL simulation by the software-based verification methodology proposed by us. The modified ARM7-Like microprocessor is able to successfully boot Linux kernel and execute user applications in FPGA.

Page generated in 0.1063 seconds