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Drawing on the theoretical literature on L2 Motivational Self System (Dörnyei, 2005, 2009) and multilingual future self-guides (Henry, 2017, 2020), this PhD project is a mixed-method study on university students' motivation to learn multiple foreign languages in China. Three overarching research aims guided the research: - To uncover the motivational profiles of multilingual future self-guides for learners of multiple foreign languages in China - To identify personal and contextual factors that contribute to the specific configurations of the motivation profiles - To examine the longitudinal effects of the multilingual future self-guides The research adopted a three-stage mixed-methods design, with the first stage and part of the second stage following an explanatory sequential design, and part of the second stage and the third stage following an exploratory sequential design. In Stage 1, 523 students who were studying English and a language other than English simultaneously were recruited from four universities in eastern China to participate in the survey study. Latent profile analysis was conducted to identify the motivational profiles of future self-guides, including both the ideal multilingual self and language-specific ideal and ought-to selves. Four motivational profiles were identified, namely Unmotivated, Obligated, English Dominant and Multilingual. The four profiles were compared in terms of behavioural and affective engagement, intended effort and self-perceived competence. Results point to Multilingual as the best performing group and Unmotivated the worst performing group, with the performance of English Dominant and Obligated being somewhere in between. To better understand the factors contributing to these motivational configurations and their corresponding outcomes, representative participants were purposively sampled from each group for follow-up semi-structured interviews in Stage 2. Specifically, 23 participants were recruited from the four groups, based on their probabilistic group membership. Interview questions were focused on the students' multilingual learning experience as well as their perceptions of multilingualism. The interview data were subject to thematic analysis, following a procedure adapted from reflexive thematic analysis (Braun & Clarke, 2016, 2013). Four common themes with six sub-themes were identified as reflecting the commonality across the four groups of learners. Eleven group-specific themes, which included six sub-themes, were identified to capture the unique characteristics of each profile. A new motivational construct, labelled as ought-to multilingual self, was discovered from the interview data and informed the measure of this construct used in Stage 3. Stage 3 is a longitudinal quantitative survey research aiming to examine the longitudinal effects of multilingual future self-guides, including the new construct from the Stage 2 findings. Two hundred and fifty-two students who were concurrently learning English and another foreign language at two universities in China were surveyed at the beginning, middle and end of an academic semester. Cross-lagged panel models were fit to the data to assess effects of multilingual future self-guides on intended effort to learn languages and their relationships with language-specific future self-guides. Findings suggest that both the ideal multilingual self and the ought-to multilingual self are relevant to multilingual learning, while operating according to different mechanisms. Combining a variety of complementary perspectives - person-centred and variable-centred, quantitative and qualitative, cross-sectional and longitudinal, this research project contributed to a deeper and more nuanced understanding of multilingual future self-guides. New insights were generated with regards to the interconnections between different types of future self-guides (e.g., motivational profiles), the longitudinal effects of higher-order future self-guides, the different mechanisms according to which the multilingual future self-guides operate, as well as the enablers of and barriers to multilingual motivation. The project also made methodological contributions to the literature, in terms of construct validity, replication research, person-centred and longitudinal quantitative techniques, and sequential mixed-methods design. The findings generated by this research could provide guidance on customised intervention, motivational strategy training, reflexive activities to address contextual barriers to multilingual motivation, as well as the development of a multilingual pedagogy from a motivational perspective.

The growth of the Internet has opened up tremendous opportunities for cooperative computations where the results depend on the private data inputs of distributed participating parties. In most cases, such computations are performed by multiple mutually untrusting parties. This has led the research community into studying methods for performing computation across the Internet securely and efficiently. This thesis investigates security methods in the search for an optimum solution to privacy- preserving distributed statistical computation problems. For this purpose, the nonparametric sign test algorithm is chosen as a case for study to demonstrate our research methodology. Two privacy-preserving protocol suites using data perturbation techniques and cryptographic primitives are designed. The first protocol suite, i.e. the P22NSTP, is based on five novel data perturbation building blocks, i.e. the random probability density function generation protocol (RpdfGP), the data obscuring protocol (DOP), the secure two-party comparison protocol (STCP), the data extraction protocol (DEP) and the permutation reverse protocol (PRP). This protocol suite enables two parties to efficiently and securely perform the sign test computation without the use of a third party. The second protocol suite, i.e. the P22NSTC, uses an additively homomorphic encryption scheme and two novel building blocks, i.e. the data separation protocol (DSP) and data randomization protocol (DRP). With some assistance from an on-line STTP, this protocol suite provides an alternative solution for two parties to achieve a secure privacy-preserving nonparametric sign test computation. These two protocol suites have been implemented using MATLAB software. Their implementations are evaluated and compared against the sign test computation algorithm on an ideal trusted third party model (TTP-NST) in terms of security, computation and communication overheads and protocol execution times. By managing the level of noise data item addition, the P22NSTP can achieve specific levels of privacy protection to fit particular computation scenarios. Alternatively, the P22NSTC provides a more secure solution than the P22NSTP by employing an on-line STTP. The level of privacy protection relies on the use of an additively homomorphic encryption scheme, DSP and DRP. A four-phase privacy-preserving transformation methodology has also been demonstrated; it includes data privacy definition, statistical algorithm decomposition, solution design and solution implementation.

At UCLA Center for Heterogeneous Integration and Performance Scaling (CHIPS), we have been developing a fine pitch heterogeneous wafer-scale platform with a single level of hierarchy called the silicon interconnect fabric (Si-IF). The Si-IF is a platform for heterogeneous integration of different bare dies at fine pitch (2 to 10 �m) and close proximity (

The elderly requires special care, especially those who live in China and living alone. This age group faces physical, mental and emotional challenges, one of which is loneliness. This paper explores the help people age 65-75 in China need to reduce their loneliness due to their children living away from them. The proposed solution is to encourage them to meet new people and keep them busy; then reducing their isolation. One such solution, a bench, is designed to curb the loneliness of elders by providing a platform to connect with each other and promoting their health through physical exercise, comfort, and safety.

Phase II clinical trials aim to potentially screen out ineffective and identify effective therapies to move forward to randomized phase III trials. Single-arm studies remain the most utilized design in phase II oncology trials, especially in scenarios where a randomized design is simply not practical. Due to concerns regarding excessive toxicity or ineffective new treatment strategies, interim analyses are typically incorporated in the trial, and the choice of statistical methods mainly depends on the type of primary endpoints. For oncology trials, the most common primary objectives in phase II trials include tumor response rate (binary endpoint) and progression disease-free survival (time-to-event endpoint). Interim strategies are well-developed for both endpoints in single-arm phase II trials. The advent of molecular targeted therapies, often with lower toxicity profiles from traditional cytotoxic treatments, has shifted the drug development paradigm into establishing evidence of biological activity, target modulation and pharmacodynamics effects of these therapies in early phase trials. As such, these trials need to address simultaneous evaluation of safety as well as proof-of-concept of biological marker activity or changes in continuous tumor size instead of binary response rates. In this dissertation, we extend a predictive probability design for binary outcomes in the single-arm clinical trial setting and develop two interim designs for continuous endpoints, such as continuous tumor shrinkage or change in a biomarker over time. The two-stage design mainly focuses on the futility stopping strategies, while it also has the capacity of early stopping for efficacy. Both optimal and minimax designs are presented for this two-stage design. The multi-stage design has the flexibility of stopping the trial early either due to futility or efficacy. Due to the intense computation and searching strategy we adopt, only the minimax design is presented for this multi-stage design. The multi-stage design allows for up to 40 interim looks with continuous monitoring possible for large and moderate effect sizes, requiring an overall sample size less than 40. The stopping boundaries for both designs are based on predictive probability with normal likelihood and its conjugated prior distributions, while the design itself satisfies the pre-specified type I and type II error rate constraints. From simulation results, when compared with binary endpoints, both designs well preserve statistical properties across different effect sizes with reduced sample size. We also develop an R package, PPSC, and detail it in chapter four, so that both designs can be freely accessible for use in future phase II clinical trials with the collaborative efforts of biostatisticians. Clinical investigators and biostatisticians have the flexibility to specify the parameters from the hypothesis testing framework, searching ranges of the boundaries for predictive probabilities, the number of interim looks involved and if the continuous monitoring is preferred and so on.

Highway construction projects serve as a good example where society can benefit from fast completion. A+B auctions, a type of innovative scoring auctions, address this concern by incentivizing timely completion through scores that combine price and time incentives. In the first part of the dissertation, I investigate in A+B auctions by building a theory of A+B bidding that incorporates incentives and production uncertainty, as well as structurally estimating bidding behaviors and auction performance using data from the California Department of Transportation (Caltran). I find that, in equilibrium, bidders skew the days bid below the true planned construction target days to raise the price bids. Moreover, self-selected construction time that is different from the expected social-optimal time causes ex post efficiency loss and the auction mechanism can fail at picking the socially-efficient bidders ex ante. Counterfactual analysis suggests that procuring schemes with lower incentives or even conversion back to traditional contracts are likely to yield better social outcomes. Usually, highway procurement auctions across the U.S. take the form of Unit-Price Contracts (UPCs), where the department of transportation (DOT) gives quantity estimates for different tasks of the project and the bidders attach unit-price bids on each of the tasks and form a single total bid. During the construction phase, the DOT makes progress payments, usually monthly, to the contractor for tasks completed in the previous month. Moreover, the payments are determined by the actual quantities incurred although the total bids ex ante are evaluated based on the DOT estimates. A forward-looking contractor would want to maximize the expected total present value by shifting more weight toward early tasks and tasks that the bidders believe to overrun compared to the DOT estimates. These two types of bid skewing lead to what is generally known in the industry as 'unbalanced bids', which I empirically test and quantify in the second part of the dissertation.

This thesis explores the ethical rules and regulations bloggers employ to protect their online communities. Rather than analyzing actual blog posts, as done by previous research, this paper focuses on comment policies in 100 feminist blogs to see how these policies reflect the ethical norms bloggers endorse and the ethical violations they encounter in the comments. Additionally, a survey of 113 feminist bloggers reveals how this subgroup of bloggers defines, communicates, and enforces the norms established in their comment policies. By comparing and contrasting the findings with existing research and theories, this study aims at answering the question of how comment policies get translated into reality and whether they appropriately address the moral dilemmas in this area. While the policies generally deal with relevant ethical violations, this study’s findings suggest that policies should particularly emphasize bigotry, prejudice based on privilege, and fat/slut/victim shaming.