published_or_final_version / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

Throughout North America, many species of aerial insectivorous birds – birds that capture flying insects – have exhibited sharp declines, with tree swallows (Tachycineta bicolor) experiencing a 2.8% annual decline in Canada since 1989. The timing of these declines coincides with major changes in agriculture, perhaps signaling a potential causal link. Declines may be influenced indirectly by agriculturally-driven reductions in the abundance of the swallow’s main diet of aerial insects through increased agrochemical use, wetland drainage and cropping intensity. My objectives were to determine how aerial insect abundance and biomass vary across an agricultural landscape in the Canadian Prairies, and determine how breeding tree swallows respond in terms of (i) foraging behaviours and return rates, (ii) body condition, and (iii) selected physiological responses (i.e. oxidative stress and feather corticosterone). Artificial nest-boxes were erected at each of 5 sites with varying levels of agricultural intensification in south-central Saskatchewan, 2012-2014. Insect abundance and biomass were monitored daily using passive aerial samplers at each of the sites throughout the breeding season. Tree swallows adults (n = 596) and nestlings (n = 1107) from each nest were captured, banded, measured and blood and feather sampled to determine condition and physiological status. In 2014, radio frequency identification (RFID) technology was employed at a subset of nest-boxes to determine adult foraging rates and durations. Despite strong differences in land use characteristics among sites, insect abundance and biomass varied by year but were similar between heavily cropped and grassland references sites. Regardless, birds responded to temporal changes in prey abundance and differences were found in measurements of foraging behavior and physiological measures of oxidative stress. Adult foraging rate (number of nest visits/hour) was primarily influenced by wind and nestling age, but was also positively related to daily insect biomass. Foraging intervals (i.e., length of time spent on each trip) differed between agricultural intensities; birds on agricultural sites spent more time away from the nest box, presumably foraging, suggesting reduced nest attentiveness. Return rates were primarily predicted by body condition and brood size from the previous breeding season, but were also higher on grassland sites, suggesting that agricultural sites may be less favorable. Older adults (based on banding records) and females displayed a higher body condition than did younger individuals and males, respectively. Measures of physiology (i.e. total antioxidant counts and oxidative damage) in both adult and nestling swallows were primarily driven by temporal changes in insect biomass and abundance. Similarly, adult body mass and physiology were related to local insect availability, but not land use (agriculture/grassland). Measures of nestling feather corticosterone were unrelated to any of the explanatory variables. These results provide valuable information pertaining to components of individual quality, foraging behaviour, and return status in response to prey availability under differing agricultural land use regimes, which may help to inform conservation strategies for a variety of insectivorous bird species of conservation concern.

One of the main problems that affect the data integrity of passive RFID systems is the collision between the tags. A popular anticollision algorithm which dominates the standards in HF and UHF passive RFID systems is Framed Slotted Aloha (FSA) and some variations of FSA. Throughput and Average time delay of the RFID system which determines the performance/efficiency of the system are reduced rapidly when the number of tags inside the interrogation zone is increased. Using larger frame sizes is not always the solution. This thesis discusses and compares the existing protocols, and proposes a variation of FSA, called Progressing Scanning (PS) algorithm. The PS algorithm divides the tags in the interrogation zone into smaller groups, and gives the ability to the reader to communicate each time with one of them. For performance analysis, the PS algorithm was evaluated with the parameters of a typical passive RFID system at 2.45 GHz . The results showed that the PS algorithm can improve the efficiency of the RFID system and provide a reliable solution for cases with a high density of tags in the area (over 800 tags ).

A inovação é um meio utilizado pelas empresas para se manterem no mercado, crescerem economicamente e gerarem vantagens competitivas. Seja a inovação referente a processo, produto, ou melhorias incrementais ou radicais, é importante estabelecer os fatores que devem ser levados em consideração no processo de adoção. Contudo, os gestores enfrentam dificuldades neste processo, dada a carência de ferramentas ou modelos que possam auxiliálos, oferecendo-lhes uma abordagem sistêmica dos fatores envolvidos. Desse modo, os objetivos desta pesquisa são identificar e analisar: 1) os fatores que devem ser levados em consideração na decisão de adotar-se a tecnologia RFID, Radio Frequency Identification, nas empresas e 2) as barreiras e facilitadores à implantação da tecnologia RFID na manufatura. Descoberta em 1935, pelo físico escocês Robert Alexander Watson-Watt, esta tecnologia foi utilizada inicialmente na Segunda Guerra Mundial para identificação de aviões inimigos. Entretanto, também pode ser empregada para rastreamento na cadeia de suprimentos, monitoramento de pessoas, verificação de autenticidade, identificação de pessoas em áreas de segurança e controle eletrônico, entre outros. O modelo apresenta quatro fatores (ambiente externo, ambiente interno, redes de inovação e tecnologia), todos passíveis de desdobramento em subfatores. Esta pesquisa limitou-se a apenas um grupo de subfatores, tendo partido da revisão bibliográfica sobre inovação tecnológica, adoção de inovação, tecnologia RFID, redes de inovação e manufatura. Na etapa seguinte, foram elaborados um questionário e um roteiro de entrevista para coleta de dados e informações. Para validá-los, foram realizados pré-testes e em seguida as modificações sugeridas pelo teste, chegando-se ao modelo conceitual final. Este foi aplicado com base na metodologia de estudos de casos múltiplos em um grupo de quatro empresas, duas das quais localizadas nos EUA e as demais no Brasil. O estudo demonstrou a utilidade dos modelos na decisão da adoção da tecnologia RFID e para a identificação das barreiras e facilitadores à sua implantação na manufatura. Por se tratar de uma tecnologia nova e dada a escassez de estudos já completados nesta área de gestão, sugere-se pesquisar elementos adicionais aos abordados nesta pesquisa. Estes incluem fatores relativos à especialidade ocupacional do indivíduo que irá operar a tecnologia, perfil, cultura e porte da empresa, influência do processo de comunicação e mensuração do retorno do investimento, bem como nível de centralização e modelo de gestão da empresa, além de outros fatores envolvidos nas redes de inovação, como governança, desenvolvimento de competências, tipo de relacionamento entre os integrantes e a sua influência no processo de internacionalização de empresas. A metodologia adotada não permite a generalização das conclusões. / Innovation is one of the means companies resort to, in order to safeguard their market position, grow financially and gain competitive advantages. Regardless of whether the innovation concerns process, product, and incremental or radical improvements, it is important to establish the factors that must be taken into account in the process of adopting it. Managers, however, have difficulty in this process, because of the lack of tools or models capable of helping them and of providing a systemic approach to the factors involved. Thus, the objectives of this research study are to identify and analyze (1) the factors that must be taken into account when deciding whether to adopt the Radio Frequency Identification (RFID) technology within a firm and (2) the barriers and facilitating elements for the implementation of RFID in manufacturing. Discovered in 1935 by the Scottish physicists Robert Alexander Watson-Watt, this technology was first used during World War II, to identify enemy aircraft. However, it can also be used to track the elements of a supply chain, monitor individuals, verify authenticity, identify people in security areas, or conduct electronic control, among other possibilities. Our model presents four factors (external environment, internal environment, innovation networks and technology), all of which can be broken down into sub-factors. This study focused on one sub-factors group. The research starting point was a bibliographical review of technological innovation, innovation adoption, RFID technology, innovation networks and manufacturing. The next stage consisted of developing a questionnaire and interview guidelines for data and information collection. These tools were then pretested for validation, which led to their adjustment and to the final conceptual model. This was then applied, based on the multiple case studies methodology, to a group of four enterprises, two of which were in the USA and the other in Brazil. The study showed the usefulness of the models for the decision of adopting RFID technology and for the identification of the barriers and facilitators connected with the implementation of RFID in manufacturing. Because it is a new technology, and given the scarcity of completed studies in this management area, we suggest researching other elements besides those addressed in our research, including those that concern the occupational specialization of the individual that will operate the technology, the profile, culture and size of the firm, the influence of the communication process and the return on investment metrics, as well as the enterprises level of centralization and management model, in addition to other factors involved in innovation networks, such as governance, development of competencies, type of relations among the network members and influence on the enterprises internationalization process. The methodology used, however, does not allow one to generalize the studys conclusions.

[pt] Esta dissertação propõe um framework de sistemas multi- agentes para aplicações do domínio de Radio Frequency Identification (RFID). Esta tecnologia de identificação automática de objetos vem se desenvolvendo rapidamente e promete substituir brevemente a tecnologia atual de identificação de produtos: código de barras. Além de promover o desenvolvimento de hardware para etiquetas e leitoras RFID, novos padrões de identificação estão sendo propostos, desafiando os desenvolvedores de software a produzirem novas soluções para lidar com o novo e maior volume de dados e com a natureza distribuída das leitoras e leituras de objetos. Esta dissertação propõe um framework projetado utilizando-se a abordagem de sistemas multi-agentes (SMA) capaz de instanciar SMA distribuídos que: - Interagem com a infra-estrutura RFID existente (leitoras, etiquetas e middlewares); - Facilitam a geração de informações com semântica de negócios a partir de dados crus gerados por esta infra-estrutura, e; - Facilitam a implementação de novas funcionalidades decorrentes do leque de aplicações vislumbradas pelo surgimento de RFID. / [en] Radio Frequency Identification (RFID) technology along with the Electronic Product Code (EPC) created a new complex environment for warehouses systems and supply chain systems in general. The EPC specification created one more level of identification: the product instance. This new level of identification had blown the volume of data being managed by applications. That fact, along with the deployment of distributed RFID readers, causes the necessity of new applications capable of interacting with this infrastructure and capable of processing, filtering and interpreting these new data. This work proposes a framework for distributed multi-agent systems capable of interacting with a deployed RFID infrastructure.

This document reports on a hands-on project aimed at learning and experiencing the concept of system-of-systems. The motivation behind this project is to study and implement the concept of System of Systems in the generation of a RF-based communication and control complex system. The goal of this project is to develop a multi-level integrated and complete system in which the vehicles that belong to a same network can become aware of their location, communicate with nearby vehicles (sometimes with no visible line of sight), be notified of the presence of different objects located in their immediate vicinity (obstacles, such as abundant vehicles), and generate a two dimensional representation of the vehicles’ location for a remote user. In addition, this system will be able to transmit back messages from the remote user to a specific or to all local vehicles. The end result is a demonstration of a complex, functional, and robust system built and tested for other projects to use and learn from. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection

近十年來，無線通訊技術、流動電話服務以及無線網絡的發展一日千里。不單止為社會帶來很多新的技術及先進的設備，更加帶來了許多新穎的應用構想。其中最被廣泛討論的要數室內無線實時定位系統。室內定位，顧名思義就是一種對一個或多個室內目標進行定位及追蹤的技術。這種技術的潛在應用非常多元化，例如倉庫管理、人力資源調配等等。透過這種技術可以使一些室內位置信息相關的服務更加自動化，從而提升服務效率。正因為市場狂熱的需求，近年來室內無線實時定位系統一直都是一個熱門的研究課題。 / 本論文的上半部主要是討論一種基於無線射頻識別技術的室內無線實時定位系統。這個系統的特點是在閱讀器的天線上應用了模擬一維綫相控陣列天線。系統的定位原理是基於三角測距法，透過相控陣的主波束掃描配合信號強度測量去估算出信號入射角。比較其他入射角測量的方法，應用這種方法的硬件成本更低而且能確保一定的精度。整個系統的開發包括有無線射頻標籤、閱讀器、模擬一維綫相控陣列天線、網絡控制器、數據庫、圖像應用界面及一種有效壓抑室內多徑問題的定位算法。這個系統的最大好處就是它不像其他一些現存的定位系統一樣，在安裝後需要進行大量的離線實地校準。我們進行了大量的實驗去客觀地驗證系統的定位性能，實驗的結果指出系統的定位誤差平均值小於一米。 / 為了控制系統的硬件成本，上述所提及到的模擬一維綫相控陣列天線會採用一種非常便宜的板材：FR4。但是FR4這種板材便宜的代價便是它相對較高的介質損耗。較高的介質損耗對模擬一維綫相控陣列天線的實現存在着一個重要的難題：模擬360º移相器的插入損耗相對電壓變化不平滑。有見及止，本論文的下半部會討論一種新穎而有效壓抑因高介質損耗而導致插入損耗不平滑的反射式移相器。新的移相器設計包含兩種壓抑插入損耗不平滑的技術。在仿真結果中，新的設計把傳統設計的插入損耗不平滑從1.4分貝大幅降低至0.3分貝。實驗的結果指出，在360o 的移相範圍內只存在着0.6分貝的插入損耗不平滑。 / 最後在此作一個總結。本論文主要是討論一種高效、低成本、基於無線射頻識別技術及模擬一維綫相控陣列天線技術的室內無線實時定位系統。大量的實驗數據證明了它良好的定位性能。而且系統的網絡設計使到它可以更彈性地應用到不同的場所。 / In recent years, the rapid development in wireless communication technologies, mobile computing devices and wireless networks has stimulated a fast growing interest in various location-aware systems that can provide real time information of physical locations of objects or persons. In this thesis, an active radio frequency identification (RFID) indoor positioning system utilizing analog linear phased array antenna (PAA) technology has been proposed and demonstrated. By using beam steering of an analog linear PAA and measuring the corresponding received signal strength indicator (RSSI), one can determine the angle of arrival (AoA) of the transmitted signal from a tag. In this work, a complete locationing system has been built, which includes RFID tag, reader integrated PAA, network controller and database with event driven functions. Besides that, a novel positioning algorithm that can effectively overcome indoor multipath effect is also proposed. The major advantage of the proposed system is that it doesn’t require any on-site calibration. Therefore, the setup of the proposed system is scenario-independent. A large number of experiments and results have demonstrated that the probabilities of spatial errors of less than 1 meter and 1.5 meters of the proposed system are about 80% and 95% respectively. / In order to have a cost-effective system, those analog linear PAAs are fabricated in FR4 substrate, with which constant insertion loss under phase steering of a 360º analog phase shifter is difficult to realize due to the substrate loss. In order to overcome this difficulty, a novel loss-compensated microstrip 360º reflection-type diode phase shifter with constant insertion loss has been proposed and concept proven. In this regard, two techniques have been investigated to reduce the insertion loss variation which is caused by using lossy substrate. As compared with the conventional design, simulation results have shown a considerable improvement on the insertion loss variation from 1.4dB to 0.3dB. Measurement results have demonstrated a 0.6dB insertion loss variation over 360º phase steering range. / In conclusion, a low-cost but with moderate performance RFID indoor locationing system based on analog linear PAA technology has been proposed and experimentally demonstrated. The prototype system has shown its high accuracy, flexibility in network deployment, and scenario-independent operation. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Hung, Wing Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 85-87). / Abstracts also in Chinese. / ABSTRACT --- p.I / 論文摘要 --- p.III / ACKNOWLEDGEMENT --- p.V / TABLE OF CONTENT --- p.VI / LIST OF FIGURES --- p.IX / LIST OF TABLES --- p.XIII / LIST OF ABBREVIATIONS --- p.XIV / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1. --- RESEARCH MOTIVATION --- p.1 / Chapter 1.2. --- OVERVIEW OF THE THESIS ORGANIZATION --- p.5 / Chapter CHAPTER 2 --- FUNDAMENTALS IN LINEAR PHASED ARRAY ANTENNA AND REFLECTION-TYPE PHASE SHIFTER --- p.6 / Chapter 2.1. --- LINEAR PHASED ARRAY ANTENNA --- p.6 / Chapter 2.1.1. --- Operating Principle --- p.7 / Chapter 2.1.2. --- Simulation Example --- p.9 / Chapter 2.2. --- REFLECTION-TYPE PHASE SHIFTER --- p.10 / Chapter 2.2.1. --- Operating Principle --- p.10 / Chapter 2.2.2. --- Simulation Example --- p.12 / Chapter CHAPTER 3 --- CONVENTIONAL INDOOR POSITIONING METHODOLOGIES --- p.15 / Chapter 3.1. --- RSSI RANGING --- p.15 / Chapter 3.1.1. --- Radio Fingerprint --- p.15 / Chapter 3.1.2. --- Radio Propagation Model --- p.17 / Chapter 3.1.3. --- Reference Tags --- p.18 / Chapter 3.1.4. --- Ordered Signal Strength Sequence --- p.19 / Chapter 3.2. --- UWB RANGING --- p.20 / Chapter 3.3. --- NEAR FIELD ELECTROMAGNETIC RANGING (NFER) --- p.21 / Chapter CHAPTER 4 --- CONVENTIONAL 360º REFLECTION-TYPE PHASE SHIFTER DESIGNS --- p.23 / Chapter 4.1. --- PARALLELING TWO SERIES-RESONANT VARACTOR CIRCUIT --- p.23 / Chapter 4.1.1. --- 360º Phase Shift --- p.24 / Chapter 4.1.2. --- Constant Insertion Loss --- p.24 / Chapter 4.1.3. --- Performance --- p.25 / Chapter 4.2. --- PARALLELING TWO ARMS HAVING 180O PHASE CHANGE WITH 90º OUT OF PHASE --- p.27 / Chapter 4.2.1. --- Linearity and 180º Phase Shift --- p.27 / Chapter 4.2.2. --- Constant Insertion Loss --- p.29 / Chapter 4.2.3. --- 360º Phase Shift --- p.29 / Chapter 4.2.4. --- Performance --- p.30 / Chapter 4.3. --- CONNECTING TWO ARMS HAVING 180O PHASE CHANGE WITH 90O OUT OF PHASE IN-SERIES --- p.31 / Chapter 4.3.1. --- Constant Insertion Loss --- p.31 / Chapter 4.3.2. --- 360º Phase Shift --- p.32 / Chapter 4.3.3. --- Performance --- p.32 / Chapter CHAPTER 5 --- AN ACTIVE RFID INDOOR POSITIONING SYSTEM UTILIZING ANALOG LINEAR PHASED ARRAY --- p.34 / Chapter 5.1. --- POSITIONING METHODOLOGY --- p.35 / Chapter 5.2. --- SYSTEM ARCHITECTURE --- p.37 / Chapter 5.2.1. --- Analog Linear Phased Array Antenna --- p.39 / Chapter 5.3. --- POSITIONING ALGORITHM --- p.51 / Chapter 5.3.1. --- Zone Decision --- p.51 / Chapter 5.3.2. --- Point Location --- p.52 / Chapter 5.4. --- EXPERIMENTAL RESULT --- p.58 / Chapter CHAPTER 6 --- NOVEL 360º REFLECTION-TYPE DIODE PHASE SHIFTER WITH CONSTANT INSERTION LOSS UNDER LOSSY SUBSTRATE --- p.65 / Chapter 6.1. --- REVIEW --- p.66 / Chapter 6.2. --- PROBLEMS --- p.68 / Chapter 6.3. --- PROPOSED SOLUTIONS --- p.71 / Chapter 6.3.1. --- Closed Reflection Coefficient Circle --- p.71 / Chapter 6.3.2. --- Centered Reflection Coefficient Circle --- p.74 / Chapter 6.4. --- SIMULATION AND MEASUREMENT RESULT --- p.77 / Chapter CHAPTER 7 --- CONCLUSION --- p.83 / REFERENCES --- p.85 / AUTHOR’S PUBLICATIONS --- p.88 / Chapter APPENDIX 1: --- DESIGN OF RFID TAG --- p.89 / Chapter APPENDIX 2: --- DESIGN OF RFID READER --- p.98 / Chapter APPENDIX 3: --- DESIGN OF RFID CONTROLLER --- p.100

A realistic comparative performance evaluation of indoor Geolocation systems is a complex and challenging problem facing the research community. This is due to the fact that performance of these systems depends on the statistical variations of the fading multipath characteristics of the wireless channel, the density and distribution of the access points in the area, and the number of the training points used by the positioning algorithm. This problem, in particular, becomes more challenging when we address RFID devices, because the RFID tags and the positioning algorithm are implemented in two separate devices. In this thesis, we have designed and implemented a testbed for comparative performance evaluation of RFID localization systems in a controlled and repeatable laboratory environment. The testbed consists of a real-time RF channel simulator, several WiFi 802.11 access points, commercial RFID tags, and a laptop loaded with the positioning algorithm and its associated user interface. In the real-time channel simulator the fading multipath characteristics of the wireless channel between the access points and the RFID tags is modeled by a modified site-specific IEEE 802.11 channel model which combines this model with the correlation model of shadow fading existing in the literature. The testbed is first used to compare the performance of the modified IEEE 802.11 channel model and the Ray Tracing channel model previously reported in the literature. Then, the testbed with the new channel model is used for comparative performance evaluation of two different WiFi RFID devices.

When we forget things, we feel anxious which can impact our day negatively. Some individuals believe they are forgetful, so emphatically, it disrupts their day. There has been little discussion about perceived forgetfulness in design and HCI, combined with few studied smart objects to aid with memory. However, embedded systems, radio frequency identification (RFID) and HCI research provides inspiration towards creating a solution. Challenges of creating a day-to-day smart object that can enhance a user's lifestyle are explored and recommended design guidelines for creating a smart object in a specific domain are the focus of this thesis. Using an experience-centred approach, 'Message Bag' and 'Tag Along' are two purpose built object-based memory aids that have emerged as a result of investigating the design processes for smart objects. The work examines smart objects in the context of forgetting what items to pack in a bag. A solution presented is a device consisting of an RFID system involving (a) pre-tagging essential items; (b) scanning those tagged items and; (c) viewing a corresponding light illuminate, to communicate to the user. Although the conceptual model is simple, success depends on a combination of technical design, usability and aesthetics. These scanning interactions result in a person feeling more confident as suggested through autoethnography reporting, real-world, third person engagements - single user walkouts, conference demos, professional critiques, and residential weekends with potential users (focus group) studies conducted. My work involved extensive autobiographical research and design-led enquiries. Testing was undertaken with investigative prototypes, followed by field testing high-fidelity prototypes. This involved an in-the-wild comparative study involving six users over several months. Results show that people feel more confident and respondents claim no longer needing to continually check items are packed, thus 'gaining time', and feeling less forgetful. Although the application of RFID is not new to ubiquitous computing, this implementation, styling and system immediacy is novel. This thesis presents the development of ten prototypes as well as design guidelines. The research provides a solid base for further exploration, and includes discovery of the importance of a user's style universe and extreme ease-of-use. I conclude with the presentation of early positive results including; (i) the unique form factor becomes a reminder itself and; (ii) usability coupled with the intuitive nature of the system is shown to be essential. We found that when you are creating a smart object, usability and an intuitive nature is even more important than in a standard system. When dealing within the domain of forgetfulness, this is paramount.

Radio Frequency Identification (RFID) has received a great deal of attention in past decades. It is an automatic identification system by replying and retrieving data remotely using RFID transponders. Basically, RFID systems can be divided into three main categories: short transmission range, medium transmission range, and long transmission range. / Short and medium range RFIDs generally are passive transponders while long range RFID is of either passive or active type. In this thesis, a short transmission range RFID transponder is presented. This is a passive transponder which generates power for internal circuitry by inductive coupling. For automatic identification applications such as electronic money tickets, the requirements of endurance, weight, size as well as cost appeal to use passive transponder rather than active transponder. Researches on the passive transponders have created a great challenge for engineers in terms of the tradeoff between power constraints, processing power and data transmission range. / The presented RFID transponder system adheres to the ISO 14443 standard Type B specification communication interface, which operates at 13.56MHz carrier frequency with a maximum read range around 50 mm. This research implemented a low power, high security, and long read range RFID transponder. For the analog RF interface, a series of novel architectures are adopted to improve the data transmission range. The digital core in the presented crypto-processor for data security. The asynchronous architecture has the advantages of fast computation time, low power consumption and small area. These are the attractive reasons to implement the core processing units using an asynchronous architecture. / This RFID system was fabricated with a 0.35um two-poly four-metal standard CMOS process with the silicon area of 1516 um x 1625 um. The measurement results show that the analog RF interface can generate a maximum 5.45mW power while the digital core circuit consumes only 2.77mW. In the wireless communication tests, the transponder read range can reach as far as 50 mm. / Leung, Pak Keung. / "June 2008." / Adviser: Choy Chin Sing. / Source: Dissertation Abstracts International, Volume: 70-03, Section: B, page: 1847. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.