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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.
111

The design and development of multi-agent based RFID middleware system for data and devices management

Massawe, Libe Valentine January 2012 (has links)
Thesis (D. Tech. (Electrical Engineering)) - Central University of technology, Free State, 2012 / Radio frequency identification technology (RFID) has emerged as a key technology for automatic identification and promises to revolutionize business processes. While RFID technology adoption is improving rapidly, reliable and widespread deployment of this technology still faces many significant challenges. The key deployment challenges include how to use the simple, unreliable raw data generated by RFID deployments to make business decisions; and how to manage a large number of deployed RFID devices. In this thesis, a multi-agent based RFID middleware which addresses some of the RFID data and device management challenges was developed. The middleware developed abstracts the auto-identification applications from physical RFID device specific details and provides necessary services such as device management, data cleaning, event generation, query capabilities and event persistence. The use of software agent technology offers a more scalable and distributed system architecture for the proposed middleware. As part of a multi-agent system, application-independent domain ontology for RFID devices was developed. This ontology can be used or extended in any application interested with RFID domain ontology. In order to address the event processing tasks within the proposed middleware system, a temporal-based RFID data model which considers both applications’ temporal and spatial granules in the data model itself for efficient event processing was developed. The developed data model extends the conventional Entity-Relationship constructs by adding a time attribute to the model. By maintaining the history of events and state changes, the data model captures the fundamental RFID application logic within the data model. Hence, this new data model supports efficient generation of application level events, updating, querying and analysis of both recent and historical events. As part of the RFID middleware, an adaptive sliding-window based data cleaning scheme for reducing missed readings from RFID data streams (called WSTD) was also developed. The WSTD scheme models the unreliability of the RFID readings by viewing RFID streams as a statistical sample of tags in the physical world, and exploits techniques grounded in sampling theory to drive its cleaning processes. The WSTD scheme is capable of efficiently coping with both environmental variations and tag dynamics by automatically and continuously adapting its cleaning window size, based on observed readings.
112

Cryptography for Ultra-Low Power Devices

Kaps, Jens-Peter E 04 May 2006 (has links)
Ubiquitous computing describes the notion that computing devices will be everywhere: clothing, walls and floors of buildings, cars, forests, deserts, etc. Ubiquitous computing is becoming a reality: RFIDs are currently being introduced into the supply chain. Wireless distributed sensor networks (WSN) are already being used to monitor wildlife and to track military targets. Many more applications are being envisioned. For most of these applications some level of security is of utmost importance. Common to WSN and RFIDs are their severely limited power resources, which classify them as ultra-low power devices. Early sensor nodes used simple 8-bit microprocessors to implement basic communication, sensing and computing services. Security was an afterthought. The main power consumer is the RF-transceiver, or radio for short. In the past years specialized hardware for low-data rate and low-power radios has been developed. The new bottleneck are security services which employ computationally intensive cryptographic operations. Customized hardware implementations hold the promise of enabling security for severely power constrained devices. Most research groups are concerned with developing secure wireless communication protocols, others with designing efficient software implementations of cryptographic algorithms. There has not been a comprehensive study on hardware implementations of cryptographic algorithms tailored for ultra-low power applications. The goal of this dissertation is to develop a suite of cryptographic functions for authentication, encryption and integrity that is specifically fashioned to the needs of ultra-low power devices. This dissertation gives an introduction to the specific problems that security engineers face when they try to solve the seemingly contradictory challenge of providing lightweight cryptographic services that can perform on ultra-low power devices and shows an overview of our current work and its future direction.
113

Reliable middleware framework for RFID system

Ahmed, Nova 29 April 2010 (has links)
The reliability of RFID systems depends on a number of factors including: RF interference, deployment environment, configuration of the readers, and placement of readers and tags. While RFID technology is improving rapidly, a reliable deployment of this technology is still a significant challenge impeding wide-spread adoption. This research investigates system software solutions for achieving a highly reliable deployment that mitigates inherent unreliability in RFID technology. We have considered two different problem domains for large scale RFID deployment. One is item tracking and the other is guidance-monitoring. Item tracking considers applications that have statically placed RFID readers to observe the RFID tagged objects in motion. An airport scenario to observe the tagged baggage or warehouse scenarios to track the tagged goods are examples of item tracking applications. A self guided tour, search and rescue scenario or a visually impaired person looking for direction and guidance in a tagged environment are examples of item location applications. It is observed that there is a notion of path that follows the direction and flow of the mobile items in the item tracking applications and a path gets created along the direction and flow of the mobile object in item location applications. A system level knowledge of the data flow can benefit the system in different aspects such as improved reliability, resource management and real time response. We have designed and implemented an RFID middleware for item tracking: RF²ID (Reliable Framework for Radio Frequency Identification) to organize and support queries over data streams in an efficient manner. We have developed (1) a virtual reader abstraction to improve the potentially error-prone nature of reader generated data (2) a novel path abstraction to capture the logical flow of information among virtual readers. Prototype implementation using both RFID readers and simulated readers using an empirical model of RFID readers show that RF²ID is able to provide high reliability, support path-based object detection and use efficient resource management techniques. We propose a middleware solution that takes into account the data flow information for item location application that requires real time response. The guidance-monitoring scenario considers mobile RFID readers that traverse in a tagged environment. We consider the scenario of an Assisted Living Center for elderly residents as a motivating guidance-monitoring application. The solution for guidance-monitoring system is called GuardianAngel. The application scenario considers a tagged indoor environment with residents having their own RFID readers to provide them with adequate information about the surroundings. The guidance and monitoring requirement can be conflicting. The guidance information requires very fine grain information about the environment to make proper decisions. On the other hand, the monitoring system must not have a fine grain knowledge which can introduce concerns such as privacy concerns. We consider this aspect during the design and implementation. The system is a two layered infrastructure that has the upper layer which is the monitoring layer. This layer is in charge of monitoring of the actors in the environment. The monitoring layer is physically a set of distributed virtual stations that have the knowledge about the environment. The environment itself is equipped with RFID tags. The residents of the environment have the mobile object that has a sensing element and a computing element (e.g., handhold device with a portable RFID reader) - the guidance server runs on this mobile object. The guidance server is in charge of making local decisions to the users. It is resource limited and asks for new information from the virtual stations as needed. The guidance server also provides the monitoring server with the information regarding the status of the mobile object. But the status information is not fine grain information - the guidance server wraps up the information over a period of time and over a larger region to hide the detailed information of the users.The system uses the logical path based abstraction to guide the users. We have implemented the real testbed using grid structured RFID devices along with scalability study using emulated RFID readers. The basic contribution of our work is based on providing novel middleware solution that is able to serve the application taking into account the inherent unreliability of RFID technology. Our path abstraction that uses the physical flow of data as an ally to generate a logical system level flow enhances the performance in many ways.
114

Leveraging radio frequency technology identification for productivity analysis in high-rise construction

Sedehi, Arya John 12 April 2010 (has links)
Until recent developments, labor productivity had been analyzed manually requiring time-consuming work and the possibility of human error. Past research has shown the multitude of benefits obtained from implementing radio frequency identification technology within various construction sites including asset tracking, inventory management, and on-site security upgrades. Additional construction improvements can be identified in terms of productivity analysis of work crews, material transport, and the overall approach to a project to determine whether the construction process is operating at maximum efficiency or can be adjusted to improve its effectiveness. This paper presents the results of implementing radio-frequency identification technology and provides a study of labor productivity analysis for a window replacement project on a high-rise construction site. This extensive study tracks the efficiency of a buck hoist worker and material lift system for transportation and illustrates the applicability of the technology despite the presence of numerous signal impeding obstacles located throughout the site. These issues are resolved with an effective automated location and time tracking system that work in both an indoor and outdoor environment simultaneously with a data recording software and database. The in-house development of the database allows for timely information retrieval of various items of interest in this study and requires less The experimental results show that RFID technology has the capacity to work and produce useful data for labor productivity purposes in an ever-changing construction environment. The research further recognizes relevant information regarding system optimization and worker feedback for future use.
115

Conductive inkjet printed antennas on flexible low-cost paper-based substrates for RFID and WSN applications

Rida, Amin H. 31 March 2009 (has links)
This thesis investigates inkjet-printed flexible antennas fabricated on paper substrates as a system-level solution for ultra-low-cost and mass production of RF structures. These modules are designed for the UHF Radio Frequency Identification (RFID) Tags and Wireless Sensor Nodes (WSN); however the approach could be easily extended to other microwave and wireless applications. Chapter 1 serves as an introduction to RFID technology and its capabilities while listing the major challenges that could potentially hinder RFID practical implementation. Chapter 2 discusses the benefits of using paper as a substrate for high-frequency applications, reporting its very good electrical/dielectric performance up to at least 1 GHz. The dielectric properties are studied by using the microstrip ring resonator. Brief discussion on Liquid Crystal Polymer (LCP) is also given in this chapter. Chapter 3 gives details about the inkjet printing technology, including the characterization of the conductive ink, which consists of nano-silver-particles, while highlighting the importance of this technology as a fast and simple fabrication technique especially on flexible organic (e.g.LCP) or paper-based substrates. Chapter 4 focuses on antenna designs. Four examples are given to provide: i) matching techniques to complex IC impedance, ii) proof of concept of inkjet printing on paper substrate through measurement results, iii) demonstration of a fully-integrated wireless sensor modules on paper and show a 2D sensor integration with an RFID tag module on paper. Chapter 5 concludes the thesis by explaining the importance of this work in creating a first step towards an environmentally friendly generation of "green" RF electronics and modules.
116

The development of a generic model for choosing a suitable traceability system for use in a manufacturing environment

Riley, Gareth 03 1900 (has links)
Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2009. / Traceability systems are capable of both tracking and tracing parts. They offer many benefits to an organisation from assisting with recall applications to monitoring the everyday workings of a production line or supply chain. There are numerous methods able to act as traceability systems but only a few can be regarded as automatic and unique identifiers. Automatic traceability of individual entities is the future. It is already widely used by a number of leading companies throughout different business sectors and wide mass adoption is imminent. At present, they are slightly more expensive than the simpler technologies but once mass produced, the cost will come down. To completely understand how traceability systems are implemented, practical experience is required. When starting a traceability project, there are a lot of different options. The different systems offer their own set of advantages and some don’t work in certain environments. It was for this reason that The Decision Making Model was developed to assist users through the difficult initial stages of traceability implementation (i.e. choosing the system most suitable to a particular environment). This model was programmed in Excel and supplies the user with a number of questions regarding the environment the system would work in as well as the user’s requirements. The answers to these questions help the user work through the different types of traceability options to eliminate unsuitable choices. The result is an easy to use program designed with the ability to be upgraded as the technologies evolve.
117

Automatic student attendance registration using radio frequency identification (RFID)

Kuriakose, Rengith Baby 03 1900 (has links)
Thesis (M. Tech.) - Central University of Technology, Free State, 2010 / The main aim of this research was to automate student attendance registration, thereby reducing human involvement in the whole process. This was made possible using Radio Frequency Identification (RFID) technology. The Central University of Technology uses student cards that are compatible for use with RFID technology. As a result, no initial investment (except for the existing personal computer’s and the constructed RFID reader) in infrastructure was required for this project. The basic working of the project was as follows. The students belonging to a specific class had their vital educational data (Student number, Name) entered into a database table at the time of registration. A student card containing a serial number, with reference to the data contained in the database table, was given to the students after registration. The students walk into their respective classes and scan their student cards with the RFID reader. The serial number stored in the student card is transferred to the reader and from there wirelessly to the main server using ZigBee technology. In the main server, using Java programming language, the card serial number is sent to the Integrated Development Environment (IDE). In this project the Netbeans IDE (Java platform) was used. The Netbeans IDE is connected to the Apache Derby database using Java Database Connector (JDBC), so the serial number (which is referenced to the educational data of the students) from the student card is automatically compared with the original database created at the time of registration. Once a match is confirmed between the two entries, the data is entered into a separate database table which serves as the basic attendance sheet for a specific day.
118

Performance analyses of Slotted ALOHA protocol in a Weibull fading environment

Unknown Date (has links)
In past and recent literature, random access protocols have been investigated with growing interest. In particular, the Slotted ALOHA protocol has been extensively used in satellite communications, and has also attracted considerable attention in many areas of wireless communication systems, especially in the cellular mobile environment. In this thesis, we investigate the performance of Slotted ALOHA, an effective random access protocol, in a Weibull fading environment. We study the performance metrics based on the signal-to-interference-and-noise ratio (SINR) model, in a cellular network system, assuming two captures models. The capture effect, also called co-channel interference tolerance, is the ability to correctly receive a strong signal from one transmitter despite significant interference from other transmitters. We derive closed-formed expressions and numerical evaluations for both the capture probability and the system throughput. he analytical results will be validated with computer simulations. Finally, to mitigate the effects of Weibull fading channel we also consider the effect of dual selection diversity that will increase the capture probability and the system throughput. / by Jean N. Rene. / Thesis (M.S.C.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
119

Utilising radio-frequency identification technologies as knowledge management enablers in academic libraries: a case study of the University of South Africa

Mogiba, Ntombizandile Cynthia 27 July 2018 (has links)
The quest to generate, preserve and utilise knowledge is driving firms and organisations towards a knowledge-based approach to managing organisational knowledge assets. Therefore, knowledge management (KM) is becoming increasingly important for organisations such as academic libraries to enhance their competitive edge in performance, to become more effective and to keep the organisation’s knowledge for future use. The importance of KM cannot be overemphasised in terms of how academic libraries can find meaningful and effective ways to manage knowledge resources to improve the services rendered to information users. Pressure is mounting for academic libraries to attain, retain and share knowledge for strategic planning, decision-making and remaining competitive. The adoption of radio-frequency identification (RFID) technologies is one of the preferred approaches to managing organisational knowledge assets; therefore, this was the motivation for undertaking this study in order to understand how these new technologies can change the knowledge management landscape in academic libraries. A qualitative research methodology, informed by the interpretivist research philosophy, was adopted in this study. Data were collected from a sample of 12 participants using non-probability purposive and convenience sampling techniques. The use of purposive and convenience techniques was ideal for this study because the participants were readily available and possessed the relevant data required to address the research questions and research problem of the study. Open-ended questions were designed to form an interview guide, which was the main data collection instrument. Annual reports, system manuals and user manuals were consulted to augment the primary data collected to address the problem at hand. The findings from the study showed that RFID technologies improved efficiency, tracking and tracing, inventory management and assisted with planning. It was revealed that users of RFID technologies required further training and development to fully utilise these systems for the benefit of the organisation. The study was conducted using a small sample of 12 participants; therefore, it was recommended that further studies could be conducted with large sample sizes using different research strategies. It was suggested that further research should be conducted to establish how change programmes have been managed before in other departments or sections and how the staff exodus was managed. An organisation-wide research would be recommended to ascertain the views and opinions of a larger population so that findings can be generalisable. / Information Science / M. Inf. (Information Science)
120

Design of high performance RFID systems for metallic item identification.

Ng, Mun Leng January 2008 (has links)
Although the origins of Radio Frequency Identification (RFID) technology can be traced back for many years, it is only recently that RFID has experienced rapid growth. That growth is mainly due to the increasing application of this technology in various supply chains. The widening of the implementation of RFID technology in supply chains has posed many challenges and one of the biggest is the degradation of the RFID system performance when tagging metallic objects, or when the RFID system operates in a metallic environment. This thesis focuses on tackling the issue of having metallic objects in an Ultra High Frequency (UHF) RFID system. The work presented in this thesis contributes to the research on UHF RFID systems involving metallic objects in several ways: (a) the development of novel RFID tags that range from a simple tag for general applications to tags suitable for metallic object identification; (b) the tag designs target the criteria of minimal tag size and cost to embrace the vision of item level tagging; and (c) the analysis of the performance (through theoretical predictions and practical measurements) of an RFID tag near metallic structures of various shapes and sizes. The early part of this thesis provides a brief introduction to RFID and reviews the background information related to metallic object identification for UHF RFID systems. The process of designing a basic tag, and additional information and work done related to the process, are outlined in the early part of this thesis. As part of this fundamental research process, and before proceeding to the designing of tags specifically for metallic objects, a small and low cost RFID tag for general applications was developed. Details of the design of this tag, with the application of this tag for animal identification, are presented. In the later parts of the work, different tag design approaches were explored and this has generated three rather different RFID tags suitable for attaching to metallic objects. The aim of this research is not just to design tags for metallic objects but also to tackle the constraints of having tags that are small in size, cost effective and suited in size to some familiar objects. Hence, in the later part of this research, the work took a step further where one of the three tags designed for metallic objects addressed the challenge of identifying individual small metallic beverage cans. RFID involves tagging of different types of objects and a tag may be required to be located in a depression of a metallic object. In the final part of this research, the read range performance of one of the RFID tags designed for metallic objects was analysed when the tag was located in metallic depressions of various shapes and sizes. The analysis was performed from a combination of theoretical calculation and simulation perspectives, and also through practical real-life measurements. Metallic objects are very common around us. Their presence is unavoidable and so to identify them, having the appropriate RFID tags suitable for operation on metallic surfaces is essential. Frequently the tags must be small in size and low in cost to allow identification at item level of individual small metallic objects. Understanding and being aware of the potential effects of metallic structures of various shapes and sizes on the tag performance is thus important. The research in this thesis into all the above can bring the industry further towards full deployment of RFID down to item level tagging. / Thesis (Ph.D.) - University of Adelaide, School of Electrical and Electronic Engineering, 2008

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