• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 60
  • 11
  • 7
  • 5
  • 4
  • 3
  • 2
  • 1
  • 1
  • Tagged with
  • 124
  • 30
  • 27
  • 26
  • 24
  • 23
  • 22
  • 16
  • 16
  • 15
  • 14
  • 11
  • 11
  • 10
  • 9
  • 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.
81

Requirements, specifications and deployment models for autonomous jobsite safety proximity monitoring

Luo, Xiaowei 24 July 2013 (has links)
Construction has a higher injury and fatality rate than most of the other industries. Given this situation, existing research has studied various issues and factors affecting construction safety management and has attempted to use all available methods to improve the construction safety performance. However, the construction accident rate remains among the highest in the United States and the world. The primary objective of this research is to advance autonomous proximity monitoring and hence provide a safer environment for construction workers. In particular, I seek to advance current evaluations of proximity warning technologies to a more robust engineering approach to the design and deployment of autonomous safety monitoring systems. The contributions of the research are demonstrated through specifications, deployments, and testing of proximity monitoring systems for crane loads and falling from height. My research advances current knowledge in three areas. First, I develop specifications for proximity safety monitoring in a sensed environment, built from existing guidelines and expert interviews. Second, I translate the specifications to computer interpretable rules and deploy them in a distributed computing environment. This demonstrates the feasibility of a systems approach and reusability of components to speed deployment. Third, I evaluate the accuracy of the specifications and systems under imperfect data. I further evaluate some approaches to dealing with imperfect data. Collectively, these advances move existing proximity warning research from evaluation of specific systems to an engineering approach to development and deployment of distributed systems with reusable components that explicitly treats imperfect data. / text
82

Seamless Handover between CDMA2000 and 802.11 WLAN using mSCTP

Deng, Feng January 2006 (has links)
With the deployment of 3G networks and gradual implementation of wireless networks, seamless handover between these wireless networks is becoming an increasingly desirable. mSCTP (Mobile Stream Control Transmission Protocol) is a new protocol developed from SCTP (Stream Control Transmission Protocol) to provide seamless handover based on IP networks. This thesis studies how to use this new protocol to handle handovers on transport level between CDMA2000 and WLAN networks. A survey of recently proposed and used mobility protocols is presented, comparing three common handover protocols operating on different layers: MIP (mobile IP) for the network layer, mSCTP for the transport layer and SIP (Session Initial Protocol) for the session layer. The results show mSCTP is the future for mobility support. Lastly, I will present a detailed procedure on how to set up handover testbed between CDMA2000 network and 802.11 WLAN based on mSCTP and the results show that the handover performed between these two networks is fast and smooth but it is affected by the signal strength of the CDMA2000.
83

A distributed system testing framework

Warman, Fiona K 29 January 2009 (has links)
Distributed systems are becoming increasingly common. However, the testing of these systems is difficult due to their non-linear, stochastic and dynamic behaviours, and limited application-level testing support. In this thesis, a prototype cluster computing-based test harness has been developed that can be used for performance testing on a variety of distributed systems. Its usefulness is demonstrated through tests conducted on an example distributed system, including using the test harness to perform a parameter search on the system in an iterative fashion.
84

A distributed system testing framework

Warman, Fiona K 29 January 2009 (has links)
Distributed systems are becoming increasingly common. However, the testing of these systems is difficult due to their non-linear, stochastic and dynamic behaviours, and limited application-level testing support. In this thesis, a prototype cluster computing-based test harness has been developed that can be used for performance testing on a variety of distributed systems. Its usefulness is demonstrated through tests conducted on an example distributed system, including using the test harness to perform a parameter search on the system in an iterative fashion.
85

A TinyOS Testbed for CC2420 Transceivers

Jamal, Muhammad Asif January 2013 (has links)
Wireless Sensor Networks (WSNs) have gained significant consideration these days, as opposed to wired sensor networks, by introducing multi-functional wireless nodes, which are smaller in size. The main advan-tage is that its wireless, so it costs less to install, maintain and reconfig-ure. These sensor nodes are used in various application areas. For ex-ample: residential, industrial, environmental and military application areas. However WSNs communication is prone to negative influences from the physical environment, such as physical obstacles and interfer-ence. Algorithms must be developed for handling these problems and also to investigate the channel properties. The purpose of this work is to design a testbed, which enables the communication of wireless sensor nodes, to capture the properties of the channel, which will, in the long run, enable better solutions to be designed which are, more appropriate to the errors in the channel. In this testbed, one channel, from the IEEE 802.15.4 channels spectrum, is dedicated as an emergency channel, which is used for handshaking and to handle channel/external interfer-ence or hardware failure between the communication of Transmitter (TX) and Receiver (RX) nodes. The remaining 15 channels are called data channels and are used for actual data transmission and control signals. Peer to Peer transmission of a transmitter-receiver pair is achieved with the introducing of beacons and acknowledgment (ACK) packets. The testbed also has the property of dual reception and data logging on a single PC by maeans of two RX nodes simultaneously from a single TX node. The dependency of the packet on the “Frame Length” byte(in the Frame header) during the reception is eliminated so that if the “Frame Length” byte is compromised, it will replace the programmer defined value with the “Frame Length” byte which helps to investigate the actual packets byte sent from the TX. Also, the Received Signal Strength (RSS) is calculated at the maximum sample rate of the channel. Power consumption is not considered in this testbed. The work is conducted on both the IEEE 802.15.4 physical and the application layers. Linux based TinyOS-2.x is used as an operating system for low power sensor devices. New algorithms are designed for each step in the development of the testbed. MICAz motes are used as nodes and an MIB520 programming board is used for burning the codes and for the purpose of gateways.
86

Komunikační hardware pro I4.0 Barman / Communication hardware for I4.0 Barman

Kubíček, Richard January 2020 (has links)
This thesis deals with description and implementation of AAS module. This thesis describes the selection of individual components of device. This module will be a part of the testbed Barman project. This project is implemented in accordance with Industry 4.0 trends. Device will be work as reader of information and ingredients from NFC tags placed on a glass. With this information, parent cell can make decision which action will be done with glass. In this thesis, software for hardware operation with AAS module will be created and described. This program will further communicate with the parent program controlling the functionality of the cell itself.
87

Real-Time Waveform Prototyping

Danneberg, Martin 01 March 2022 (has links)
Mobile Netzwerke der fünften Generation zeichen sich aus durch vielfältigen Anforderungen und Einsatzszenarien. Drei unterschiedliche Anwendungsfälle sind hierbei besonders relevant: 1) Industrie-Applikationen fordern Echtzeitfunkübertragungen mit besonders niedrigen Ausfallraten. 2) Internet-of-things-Anwendungen erfordern die Anbindung einer Vielzahl von verteilten Sensoren. 3) Die Datenraten für Anwendung wie z.B. der Übermittlung von Videoinhalten sind massiv gestiegen. Diese zum Teil gegensätzlichen Erwartungen veranlassen Forscher und Ingenieure dazu, neue Konzepte und Technologien für zukünftige drahtlose Kommunikationssysteme in Betracht zu ziehen. Ziel ist es, aus einer Vielzahl neuer Ideen vielversprechende Kandidatentechnologien zu identifizieren und zu entscheiden, welche für die Umsetzung in zukünftige Produkte geeignet sind. Die Herausforderungen, diese Anforderungen zu erreichen, liegen jedoch jenseits der Möglichkeiten, die eine einzelne Verarbeitungsschicht in einem drahtlosen Netzwerk bieten kann. Daher müssen mehrere Forschungsbereiche Forschungsideen gemeinsam nutzen. Diese Arbeit beschreibt daher eine Plattform als Basis für zukünftige experimentelle Erforschung von drahtlosen Netzwerken unter reellen Bedingungen. Es werden folgende drei Aspekte näher vorgestellt: Zunächst erfolgt ein Überblick über moderne Prototypen und Testbed-Lösungen, die auf großes Interesse, Nachfrage, aber auch Förderungsmöglichkeiten stoßen. Allerdings ist der Entwicklungsaufwand nicht unerheblich und richtet sich stark nach den gewählten Eigenschaften der Plattform. Der Auswahlprozess ist jedoch aufgrund der Menge der verfügbaren Optionen und ihrer jeweiligen (versteckten) Implikationen komplex. Daher wird ein Leitfaden anhand verschiedener Beispiele vorgestellt, mit dem Ziel Erwartungen im Vergleich zu den für den Prototyp erforderlichen Aufwänden zu bewerten. Zweitens wird ein flexibler, aber echtzeitfähiger Signalprozessor eingeführt, der auf einer software-programmierbaren Funkplattform läuft. Der Prozessor ermöglicht die Rekonfiguration wichtiger Parameter der physikalischen Schicht während der Laufzeit, um eine Vielzahl moderner Wellenformen zu erzeugen. Es werden vier Parametereinstellungen 'LLC', 'WiFi', 'eMBB' und 'IoT' vorgestellt, um die Anforderungen der verschiedenen drahtlosen Anwendungen widerzuspiegeln. Diese werden dann zur Evaluierung der die in dieser Arbeit vorgestellte Implementierung herangezogen. Drittens wird durch die Einführung einer generischen Testinfrastruktur die Einbeziehung externer Partner aus der Ferne ermöglicht. Das Testfeld kann hier für verschiedenste Experimente flexibel auf die Anforderungen drahtloser Technologien zugeschnitten werden. Mit Hilfe der Testinfrastruktur wird die Leistung des vorgestellten Transceivers hinsichtlich Latenz, erreichbarem Durchsatz und Paketfehlerraten bewertet. Die öffentliche Demonstration eines taktilen Internet-Prototypen, unter Verwendung von Roboterarmen in einer Mehrbenutzerumgebung, konnte erfolgreich durchgeführt und bei mehreren Gelegenheiten präsentiert werden.:List of figures List of tables Abbreviations Notations 1 Introduction 1.1 Wireless applications 1.2 Motivation 1.3 Software-Defined Radio 1.4 State of the art 1.5 Testbed 1.6 Summary 2 Background 2.1 System Model 2.2 PHY Layer Structure 2.3 Generalized Frequency Division Multiplexing 2.4 Wireless Standards 2.4.1 IEEE 802.15.4 2.4.2 802.11 WLAN 2.4.3 LTE 2.4.4 Low Latency Industrial Wireless Communications 2.4.5 Summary 3 Wireless Prototyping 3.1 Testbed Examples 3.1.1 PHY - focused Testbeds 3.1.2 MAC - focused Testbeds 3.1.3 Network - focused testbeds 3.1.4 Generic testbeds 3.2 Considerations 3.3 Use cases and Scenarios 3.4 Requirements 3.5 Methodology 3.6 Hardware Platform 3.6.1 Host 3.6.2 FPGA 3.6.3 Hybrid 3.6.4 ASIC 3.7 Software Platform 3.7.1 Testbed Management Frameworks 3.7.2 Development Frameworks 3.7.3 Software Implementations 3.8 Deployment 3.9 Discussion 3.10 Conclusion 4 Flexible Transceiver 4.1 Signal Processing Modules 4.1.1 MAC interface 4.1.2 Encoding and Mapping 4.1.3 Modem 4.1.4 Post modem processing 4.1.5 Synchronization 4.1.6 Channel Estimation and Equalization 4.1.7 Demapping 4.1.8 Flexible Configuration 4.2 Analysis 4.2.1 Numerical Precision 4.2.2 Spectral analysis 4.2.3 Latency 4.2.4 Resource Consumption 4.3 Discussion 4.3.1 Extension to MIMO 4.4 Summary 5 Testbed 5.1 Infrastructure 5.2 Automation 5.3 Software Defined Radio Platform 5.4 Radio Frequency Front-end 5.4.1 Sub 6 GHz front-end 5.4.2 26 GHz mmWave front-end 5.5 Performance evaluation 5.6 Summary 6 Experiments 6.1 Single Link 6.1.1 Infrastructure 6.1.2 Single Link Experiments 6.1.3 End-to-End 6.2 Multi-User 6.3 26 GHz mmWave experimentation 6.4 Summary 7 Key lessons 7.1 Limitations Experienced During Development 7.2 Prototyping Future 7.3 Open points 7.4 Workflow 7.5 Summary 8 Conclusions 8.1 Future Work 8.1.1 Prototyping Workflow 8.1.2 Flexible Transceiver Core 8.1.3 Experimental Data-sets 8.1.4 Evolved Access Point Prototype For Industrial Networks 8.1.5 Testbed Standardization A Additional Resources A.1 Fourier Transform Blocks A.2 Resource Consumption A.3 Channel Sounding using Chirp sequences A.3.1 SNR Estimation A.3.2 Channel Estimation A.4 Hardware part list / The demand to achieve higher data rates for the Enhanced Mobile Broadband scenario and novel fifth generation use cases like Ultra-Reliable Low-Latency and Massive Machine-type Communications drive researchers and engineers to consider new concepts and technologies for future wireless communication systems. The goal is to identify promising candidate technologies among a vast number of new ideas and to decide, which are suitable for implementation in future products. However, the challenges to achieve those demands are beyond the capabilities a single processing layer in a wireless network can offer. Therefore, several research domains have to collaboratively exploit research ideas. This thesis presents a platform to provide a base for future applied research on wireless networks. Firstly, by giving an overview of state-of-the-art prototypes and testbed solutions. Secondly by introducing a flexible, yet real-time physical layer signal processor running on a software defined radio platform. The processor enables reconfiguring important parameters of the physical layer during run-time in order to create a multitude of modern waveforms. Thirdly, by introducing a generic test infrastructure, which can be tailored to prototype diverse wireless technology and which is remotely accessible in order to invite new ideas by third parties. Using the test infrastructure, the performance of the flexible transceiver is evaluated regarding latency, achievable throughput and packet error rates.:List of figures List of tables Abbreviations Notations 1 Introduction 1.1 Wireless applications 1.2 Motivation 1.3 Software-Defined Radio 1.4 State of the art 1.5 Testbed 1.6 Summary 2 Background 2.1 System Model 2.2 PHY Layer Structure 2.3 Generalized Frequency Division Multiplexing 2.4 Wireless Standards 2.4.1 IEEE 802.15.4 2.4.2 802.11 WLAN 2.4.3 LTE 2.4.4 Low Latency Industrial Wireless Communications 2.4.5 Summary 3 Wireless Prototyping 3.1 Testbed Examples 3.1.1 PHY - focused Testbeds 3.1.2 MAC - focused Testbeds 3.1.3 Network - focused testbeds 3.1.4 Generic testbeds 3.2 Considerations 3.3 Use cases and Scenarios 3.4 Requirements 3.5 Methodology 3.6 Hardware Platform 3.6.1 Host 3.6.2 FPGA 3.6.3 Hybrid 3.6.4 ASIC 3.7 Software Platform 3.7.1 Testbed Management Frameworks 3.7.2 Development Frameworks 3.7.3 Software Implementations 3.8 Deployment 3.9 Discussion 3.10 Conclusion 4 Flexible Transceiver 4.1 Signal Processing Modules 4.1.1 MAC interface 4.1.2 Encoding and Mapping 4.1.3 Modem 4.1.4 Post modem processing 4.1.5 Synchronization 4.1.6 Channel Estimation and Equalization 4.1.7 Demapping 4.1.8 Flexible Configuration 4.2 Analysis 4.2.1 Numerical Precision 4.2.2 Spectral analysis 4.2.3 Latency 4.2.4 Resource Consumption 4.3 Discussion 4.3.1 Extension to MIMO 4.4 Summary 5 Testbed 5.1 Infrastructure 5.2 Automation 5.3 Software Defined Radio Platform 5.4 Radio Frequency Front-end 5.4.1 Sub 6 GHz front-end 5.4.2 26 GHz mmWave front-end 5.5 Performance evaluation 5.6 Summary 6 Experiments 6.1 Single Link 6.1.1 Infrastructure 6.1.2 Single Link Experiments 6.1.3 End-to-End 6.2 Multi-User 6.3 26 GHz mmWave experimentation 6.4 Summary 7 Key lessons 7.1 Limitations Experienced During Development 7.2 Prototyping Future 7.3 Open points 7.4 Workflow 7.5 Summary 8 Conclusions 8.1 Future Work 8.1.1 Prototyping Workflow 8.1.2 Flexible Transceiver Core 8.1.3 Experimental Data-sets 8.1.4 Evolved Access Point Prototype For Industrial Networks 8.1.5 Testbed Standardization A Additional Resources A.1 Fourier Transform Blocks A.2 Resource Consumption A.3 Channel Sounding using Chirp sequences A.3.1 SNR Estimation A.3.2 Channel Estimation A.4 Hardware part list
88

Multiwavelength Study of Pulsation and Dust Production in Mira Variables Using Optical Interferometry for Constraints

Creech-Eakman, M. J., Hora, J., Ivezic, Z., Jurgenson, C., Luttermoser, D., Marengo, M., Speck, A., Stencel, R., Thompson, R. R. 01 December 2009 (has links)
Optical interferometry is a technique by which the diameters and indeed the direct pulsations of stars are routinely being measured. As a follow-on to a 7 year interferometric campaign to measure the pulsations of over 100 mira variables, our team has been using the Spitzer Space Telescope to obtain 95 mid-infrared spectra of 25 miras during their pulsations over one year while simultaneously ascertaining their near-infrared diameters using the Palomar Testbed Interferometer. These data will then be combined with modeling from NLTE and radiative transfer codes to place hard constraints on our understanding of these stars and their circumstellar environments. We present some initial results from this work and discuss the next steps toward fully characterizing the atmosphere, molecular photosphere and dust production in mira variables.
89

Development and Implementation of Control Strategies for Effective Management of Distributed Energy Resources

Kini, Roshan Laxman January 2019 (has links)
No description available.
90

Application of Deep Learning in Deep Space Wireless Signal Identification for Intelligent Channel Sensing

Kabir, Md Faisal January 2020 (has links)
No description available.

Page generated in 0.0194 seconds