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An experimental and analytical investigation was conducted to study the behavior of diagonal knee moment end-plate connections and a multiple row extended moment end-plate connection. Diagonal knee moment end-plate connections differ from typical moment end-plate connections because of the large pitch distance required between the top flange and first row of tension bolts. The large pitch distance is outside of the geometric parameters of all previous research. Design solutions are presented for five moment end-plate connections with provisions added to accommodate these parameters. The analytical investigation focused on the limit states of end-plate yielding and bolt rupture. Yield-line analysis was used to predicted end-plate yielding and a simplified Kennedy method proposed by Borgsmiller and Murray (1995) was used to predict bolt rupture including and excluding prying forces. An experimental investigation was conducted to verify the design solutions. Five knee area specimens and one plate girder specimen were tested in this study. The analytical and experimental results are analyzed and compared. For the test specimens that failed in the connection, the predicted results proved to be conservative. Recommendations are presented at the end of the study as well as sample calculations. / Master of Science

In online service systems, delay experienced by a user from the service request to the service completion is one of the most critical performance metrics. To improve user delay experience, in this thesis, we investigate a novel aspect of system design: proactive serving, where the system can predict future user request arrivals and allocate its capacity to serve these upcoming requests proactively. This approach is complementary to the conventional capacity boosting mechanism and is motivated by recent industrial and academic advances. In particular, we investigate the fundamentals of proactive serving from a queuing theory perspective. / First, most importantly, we show that under proactive serving the average user delay decreases exponentially (in the prediction window size) for a wide range of queuing models. Furthermore, the delay reduction is robust against prediction errors. We also show that both the variance of user delay and the tail of user delay decrease exponentially under proactive serving, which are also important user delay experience metrics. / We then show that proactive serving is more effective in decreasing user delay than capacity boosting in light workload regime. In particular, the average user delay decays inverse-proportionally in system capacity, but exponentially in the prediction window size in proactive serving. / Finally we demonstrate how to leverage proactive serving in system design from a optimization point of view, e.g., how many resources are dedicated to proactive serving. The results provide useful engineering insights to system designers. / Our trace-driven simulation results demonstrate the practical power of proactive serving: for example, under the YouTube data trace of 1000 different videos, the average user delay can be decreased by 50% when the system predicts 100 seconds ahead. Our results provide useful insights for proactive serving and justify its increasing applications in practical systems. / 對於在線服務系統，由於系統服務造成的用戶延遲是衡量系統性能的重要指標。提高用戶的延遲體驗的傳統方法是提高系統中服務器的性能。在本論文中，我們研究一種新穎的叫做“前瞻性服務”的方法用來提高用戶的延遲體驗。前瞻性服務是指系統在預測用戶需求的基礎上，在用戶產生需求之前，系統已經將服務送到用戶手中。前瞻性服務是傳統方法的有力補充。我們從排隊論的角度研究前瞻性服務對用戶的延遲的提高。 / 首先，對於多种排隊系統，我們證明前瞻性服務能夠指數性降低用戶的平均延遲。而且前瞻性服務對於用戶需求預測的誤差具有魯棒性。我們同時也證明了前瞻性服務能夠指數性降低用戶的延遲方差和尾概率。 / 然後，我們證明前瞻性服務在系统低负载时比傳統方法在降低用戶的平均延遲上更加有效。前瞻性服務能夠指數性降低用戶的平均延遲。而通過提高系統服務器性能，只能反比例降低用戶的平均延遲。 / 最後，我們從優化的角度分析怎樣在系統設計中利用前瞻性服務，給系統設計者提供有用的建議。 / 我們基於實際數據的仿真結果驗證了前瞻性服務在實際系統的作用。例如，基於Youtube數據的仿真表明，如果系統能提前一百秒預測用戶的需求，那麼前瞻性服務能夠降低一半的用戶延遲。 / Zhang, Shaoquan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 103-108). / Abstracts also in Chinese. / Title from PDF title page (viewed on 02, December, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

What formal guarantees should a secure messaging application provide? Do the most widely-used protocols provide them? Can we do better? In this thesis we answer these questions and with them give a formal study of modern secure messaging protocols, which encrypt the personal messages of billions of users. We give definitions and analyses of two protocols: one existing (Signal) and one new (ART). For Signal, we begin by extending and generalising classic computational models, in order to apply them to its complex ratcheting key derivations. With a threat model in mind we also define a security property, capturing strong secrecy and authentication guarantees including a new one which we call "post-compromise security". We instantiate Signal as a protocol in our model, stating its security theorem and sketching a computational reduction. Signal only supports encrypting messages between two devices, and so most implementers have built custom protocols on top of it to support group conversations. These protocols usually provide weaker security guarantees, and in particular usually do not have post-compromise security. We propose a new protocol called ART, whose goal is to bring Signal's strong security properties to conversations with multiple users and devices. We give a design rationale and a precise definition of ART, and again generalise existing computational models in order to formally specify its security properties and sketch a security reduction. ART has enjoyed widespread interest from industry, and we aim to turn it into an open standard for secure messaging. To that end, we have brought it to the IETF and formed a working group called Messaging Layer Security, with representatives from academia as well as Facebook, Google, Twitter, Wire, Cisco and more. Through MLS, we hope to bring ART's strong guarantees to practical implementations across industry. After concluding our analyses we pause for a moment, and start looking towards the future. We argue that for complex protocols like Signal and ART we are reaching the limits of computational methods, and that the future for their analysis lies with symbolic verification tools. To that end we return to the symbolic model and give a number of case studies, in each one showing how a traditional limitation of symbolic models can in fact be seen as a modelling artefact.

The city of Melbourne in Victoria, Australia has been recognised as having high quality drinking water, but like other urban cities in the world, its growing population means increasing water demand. Melbourne is also already on its eight year of dry climatic conditions and is currently experiencing a drought that forced water authorities to impose water restrictions after 20 years of unrestricted supply. The current drought, dwindling supplies and possible impact of climate change highlight the importance of making better use of this precious resource. The Water Resources Strategy has been developed for Melbourne, which serve as the basis for the Victorian Government to set per capita consumption reduction targets of 15%, 25% and 30% by 2010, 2015 and 2020 respectively. The strategy was developed to ensure a continuation of a safe, reliable and cost effective water supply that is environmentally sustainable in the long term. This is in recognition that population growth and water consumption will eventually require additional supplies of water (Water Resources Strategy Committee for the Melbourne Area 2002). One of the key findings of the National Land and Water Resources Audit's Australian Water Resources Assessment 2000 is the lack of detailed knowledge about the end use (Australian Water Association 2001). The

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User development of applications provides end users with an alternative to the traditional process of systems development by allowing them to solve job related problems by developing their own software applications. User developed applications (UDAs) support decision making and organisational processes in the majority of organisations, and the ability to develop small applications forms part of the job requirements for many positions. Despite its pervasiveness, there are many risks associated with user development of applications. These risks result primarily from decreases in application quality that arise when end users have had little training and do not follow system development methodologies. The primary aim of the research described in this thesis is to gain a better understanding of UDA success. In particular, the thesis considers the role of system quality in UDA success and the ability of end user developers to judge whether the applications they develop will have a positive impact on their performance of tasks. The research also investigates factors that might impact upon this ability. The research objectives were addressed through two empirical studies. Two possible models of UDA success provided the starting point for Study 1. The first model is DeLone and McLean’s (1992) model of IS success, and the second model is a version of this model that was modified to address concerns about the DeLone and McLean model and to reflect current research about UDA success. The models were tested using data from a field study involving business people participating in a business policy simulation, where they developed spreadsheet applications to assist in decision making. Structural equation modelling was used to test the models. Neither of the models was well supported by the data. However, the analysis provided strong support for relationships between perceived system quality and user satisfaction, information quality and user satisfaction, user satisfaction and intended use, and user satisfaction and individual impact. It is notable that the model paths that were supported in Study 1 were primarily those that reflect user perceptions rather than objective measures. This study highlighted that user perceptions of information systems success play a significant role in the UDA domain. The results did, however, suggest that there might be a direct relationship between system quality and individual impact. Study 2 was a laboratory experiment and the participants were end users from a range of organisations. A revised research model was developed based on the findings of Study 1, and structural equation modelling was again used to test the model. The model paths that were supported suggest that for small to moderate applications, increases in spreadsheet development knowledge lead to increases in system quality and consequently the development of better quality spreadsheets. They also suggest that for these kinds of applications, end users have realistic perceptions of system quality and hence that user satisfaction may be an appropriate measure of UDA success. The results of Study 2 also provided insight into the role of user involvement in end user development, clarifying the process by which benefits are obtained. The study also provided insight into the importance of spreadsheet development knowledge for successful use (as well as development) of a spreadsheet application. The results described in this thesis have practical implications for the management of user development of applications. They highlight the need either to increase end user levels of development knowledge via training so that end users can cope with applications of greater complexity, or to provide other forms of support for development. The role of organisational standards and guidelines is also be considered in the thesis and it is suggested that there is a particular need for guidelines on what kinds of applications are suitable for end user development.

Nowadays, computer networks have always been complicated deployment for both the scientific and industry groups as they attempt to comprehend and analyze network performance as well as design efficient procedures for their operation. In software-defined networking (SDN), predicting latency (delay) is essential for enhancing performance, power consumption and resource utilization in meeting its significant latency requirements. In this thesis, we present a graph-based formulation of Abilene Network and other topologies and apply a Graph Neural Network (GNN)-based model, Spatial-Temporal Graph Convolutional Network (STGCN), to predict end-to-end packet delay on this formulation. The evaluation uses STGCN to compare with other machine learning methods: Multiple Linear Regression (MLR), Extreme Gradient Boosting (XGBOOST), Random Forest (RF), and Neural Network (NN). Datasets in use include Abilene, 15-node scale-free, 24-node GEANT2, and 50-node networks. Notably, our GNN-based methodology can achieve 97.0%, 95.9%, 96.1%, and 63.1% less root mean square error (RMSE) in the most complex network situation than the baseline predictor, MLR, XGBOOST and RF, respectively. All the experiments show that STGCN has good prediction performance with small and stable prediction errors. This thesis illustrates the feasibility and benefits of a GNN approach in predicting end-to-end delay in software-defined networks.

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The purpose of this quasi-experimental study was to assess the ongoing impact of the End-of-Life Nursing Education Consortium (ELNEC) training program on registered nurses’ death anxiety, concerns about dying, and knowledge of the dying process utilizing the principles of The Comfort Theory and Practice by Kolcaba (2003) at the institutional level. The research hypothesis was upon completion of the ELNEC training, registered nurses would have decreased death anxiety, less concerns about dying, and increased knowledge of the dying process. The Revised Death Anxiety Scale (RDAS) was used to measure death anxiety which is a 25 item self-report questionnaire. The Concerns about Dying Instrument (CAD) was used to measure death attitude or concerns about dying which includes three distinct but related areas for providers: general concern about death, spirituality, and concerns about working with dying patients. Participant's perceived knowledge of dying was measured using a self report 5-point Likert format with “0“ indicating no level of knowledge to “4“ reflecting complete knowledge of death and dying. Pre-tests of all dependent variables were administered to both a treatment and control group. Post-tests were administered two weeks after the two day ELNEC training, at 6 months, and finally at 12 months to both groups in order to study its lasting efficiency upon participants at one primary care medical center. Thirty eight participants completed all four questionnaires with 27 participants in the control group and 11 participants in the experimental group. Matched pair analysis with 11 participants in each group was conducted with statistical significance found for perceived knowledge about dying at post two weeks and 12 months (p= 0.01) for the intervention group. Death anxiety and concerns about dying were not found to be statistically significant at any testing interval, but mean scores of the treatment group revealed less death anxiety and concerns about dying. Recommendations included offering the ELNEC training on a routine basis to all registered nurses who care for dying patients. Additionally, clinicians and administrators were encouraged to seek out additional funding opportunities to plan more robust studies with larger samples, incentives, and research method triangulation addressing the qualitative aspects of palliative care. / Ph. D.