211 research outputs found
Nonparametric and semiparametric regression, missing data, and related algorithms:
No full textThis dissertation consists of two chapters: Chapter 1 develops nonparametric and semiparametric regression methodologies which relate the group testing responses to the individual covariates information. In this chapter, we extend the parametric regression model of Xie (2001) for binary group testing data to the nonparametric and semiparametric models. We fit nonparametric and semiparametric models and obtain estimators of the parameters by maximizing penalized likelihood function. For implementation, we apply EM algorithm considering the individual responses as complete data and the group testing responses as observed data. Simulation studies are performed to illustrate the methodologies and to evaluate the finite sample performance of our methods. In general, group testing involves a large number of subjects, hence, the computational aspect is also discussed. The results show that our estimation methods perform well for estimating both the individual probability of positive outcome and the prevalence rate in the population.
Chapter 2 studies a partially linear regression model with missing response variable and develops semiparametric efficient inference for the parametric component of the model. The missingness considered here includes a broad range of missing patterns. For the estimation method, we use the concept of least favorable curve, least favorable direction and the generalized profile likelihood in Severini and Wong (1992). Asymptotic distributions for the estimators of the parametric components are obtained. It is shown that the estimators are asymptotically normally distributed under some conditions. Furthermore, we prove that the asymptotic covariance of the estimators achieves the semiparametric lower bound under the regularity conditions and additional conditions given in the appendix.
We also propose an algorithm which runs iteratively between fitting parametric components and fitting nonparametric components while holding the other fixed. EM algorithms are used in estimating the parametric components by a semiparametric estimating equation and in estimating the nonparametric components by smoothing methods. It is proved that the estimators from this iterative algorithm equal to the conditional expectations (conditioned on observed data) of the semiparametric efficient estimators from complete data. The methodology is illustrated and evaluated by numerical examples.Ph.D.Includes bibliographical referencesby Mingyu L
sj-pdf-1-ajs-10.1177_03635465231198501 – Supplemental material for Inhibition of IKKβ via a DNA-Based In Situ Delivery System Improves Achilles Tendinopathy Healing in a Rat Model
No full textSupplemental material, sj-pdf-1-ajs-10.1177_03635465231198501 for Inhibition of IKKβ via a DNA-Based In Situ Delivery System Improves Achilles Tendinopathy Healing in a Rat Model by Zilu Ge, Mingyu Yang, Danfeng Wei, Dong Wang, Renliang Zhao, Xiangtian Deng, Yunfeng Tang, Qian Fang, Zhencheng Xiong, Chengshi Wang, Guanglin Wang, Wei Li and Kanglai Tang in The American Journal of Sports Medicine</p
GE-mini: a mobile APP for large-scale gene expression visualization
No full textThe Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) projects produced large-scale RNA sequencing data, which provides an opportunity for performing integrated expression analysis for all genes across tens of thousands of tumor and normal tissue specimens. Rapid access to and easy visualization of such valuable data could facilitate research in a wide biological area. Here, we present the GE-mini APP for smart phones, a mobile visualization tool for integrated gene expression data based on both TCGA and GTEx. This gene-centric expression viewer provides a convenient method for displaying expression profiles of all available tumor and tissue types, while allowing drilling down to detailed views for specific tissue types.National Natural Science Foundation of China [31530036, 81573022]; Key Technologies RD Program [2016YFC0900100]SCI(E)ARTICLE6941-9433
Comparative Study of Vortex-Induced Vibration of FRP Composite Risers with Large Length to Diameter Ratio Under Different Environmental Situations
No full textThe increasing attraction of crude resources on the ocean floor leads to the development of risers, which are an indispensable component of an offshore oil and gas exploitation structure. High-grade steel is normally utilized for risers, however, fiber reinforced polymer (FRP) composite risers have become a feasible and economical alternative due to the desirable properties of the material. A comparative study of vortex-induced vibration (VIV) of FRP composite risers with two designed geometries were conducted and an X80 steel riser was used as the benchmark. The length to diameter ratios of all three risers were set to 100 and their VIV responses under different environmental situations, including the natural frequencies, global displacements, global stresses and the stress distributions in every composite layers, were obtained using computational fluid dynamics (CFD) simulation with coupled fluid–structure interaction. The VIV characteristics of both FRP composite risers and their distinction compared with that of steel risers were analyzed and discussed. From this paper, the dynamic characteristics in different environmental situations of VIV for FRP composite risers can be further understood.</jats:p
Experimental Study on Vortex-Induced Vibration of Risers Considering the Effects of Different Design Parameters
No full textRisers are an indispensable component of offshore oil and gas exploitation structures, and they are vulnerable to vortex-induced vibration (VIV). Although many studies have been conducted to investigate the VIV characteristics of risers, the effects of combination of multiple parameters and the relative significance of each parameter on the risers’ VIV characteristics have rarely been considered. In this paper, 36 experimental cases were investigated to study the risers’ VIV characteristics due to the combination of multiple parameters. The natural frequencies, response microstrains and frequencies of VIV for the risers were obtained. Meanwhile, the effect of each parameter and the relative significance of these parameters on the amplitude of VIV in risers were calculated using grey relational analysis (GRA). The results show that all the parameters considered—i.e., material property (modulus and density), end condition, top tension force and flow velocity—affect risers’ VIV response, and the grey relational grade of these parameters are: r 02 ( velocity ) > r 04 ( constraints ) > r 05 ( density ) > r 03 ( tension ) > r 01 ( modulus ) .</jats:p
[[alternative]]The Transmission of Western Learning and the Evidential Studies of Natural Knowledge in Laye Ming : The Case of Xiong Mingyu on the Generation of Hail
No full text[[abstract]]明末耶穌會士來華傳教，引入與中國傳統不同的另類自然知識，不僅開始行程兩種文化中自然知識的競爭，也促使士人以西學為鏡來省思傳統中國的自然知識，並加以考證或考據。本文以熊明遇（1579-1649）在《則草》與《格致草》中處理冰雹生成為例，來檢視他對留存於文獻中的自然知識進行考據與反應。
筆者發現，朱熹理學在建立「格物窮理」時，將「物各有理」擴及奇異的蜥蜴生雹，肯定蜥蜴生雹有其理。此一見解從宋流傳到明末。在亞里斯多德自然則學衝擊下，熊明遇是首位關注耶穌會士對冰雹的形成與朱熹理學對蜥蜴生雹解說不一致的士人。他不但質疑儒者「雹理不明」，並將蜥蜴生雹的「奇異」貶入繆論之中，即為思索儒學（或理學）與科學進的關係提供一個異例，也為名戴自然知識的考據，提供一個堅實的佳例。熊明遇無疑是西學影響下明代自然知識考據學的先驅者。
In late Ming, while Jesuits came to propagate Christianity in China, they also transmitted alternative natural knowledge which is different from that of Chinese. This paper aims at investigating the evidential studies of traditional natural knowledge in terms of that of western learning done by Xiong Mingyu (1579-1649) in his works of Ze cao 則草 and Gezhi cao格致草.The author finds that, in Song dynasty Zhu Xi believed that hail was generated by lizards. This view became popular from Song to the end of Ming. Nevertheless, in the context of "gewu qiongli," it implies that the bizarre case of hail generated by lizards has its own reason. Under the impact of Aristotelian natural philosophy, Xiong Mingyu found that the reasons put forth to explain the generation of hail in Chinese traditions were different from that of Aristotelian philosophers. Through his evidential study on this case, he contended that the reasons offered by Confucians are not clear; especially, he considered the generation of hail by lizards to be groundless. It became a very solid case of the relation between Neo-Confucianism and science, showing that Xiong Mingyu was a pioneer of the evidential studies of natural knowledge in the encounter of western natural philosophy and Neo-Confucianism.[[fileno]]JA01_2007_p11
Equity-Based Crowdfunding in China: Beginning with the First Crowdfunding Financing Case
No full textAbstractAlthough the legality of equity-based crowdfunding was determined from a judicial point of view in the “first crowdfunding financing case” in 2015, there is no formal law, regulation, or rule released to regulate the crowdfunding financing. From a micro-perspective, determining the nature and workings of equity-based crowdfunding are two preconditions for determining the legal framework for and supervision of equity-based crowdfunding. The “Open, Public, Small-sum” characteristics defined the nature of public offering to the equity-based crowdfunding; therefore, it should be distinguished from private equity financing as a different category of online equity financing. Based on the original purpose of “financing facility” and the nature of “grassroots finance,” fundraisers shall enjoy exemptions on small sums, and the threshold of investors shall also be appropriately restricted, while the intermediary platform shall be the regulatory focus. From a macro point of view, the supervision of equity-based crowdfunding should seek a balance between “financial innovation” and “risk control.” Equity-based crowdfunding should not simply be considered a financing method. Rather, its positive effects on mass entrepreneurship and innovation should be emphasized so as to make it a particularly important “booster” to promote economic and social development.</jats:p
Enhancing Mobility around Schiphol Airport for International Passengers
No full textThis study presents the process and results of the graduation project: Enhancing Mobility Experience around Schiphol Airport for International passengers.This project is part of this project Optimaliseren Mobiliteit rondom Schiphol (in English Optimise Mobility around Schiphol). Within its broad scope, this graduation focuses on Chinese passengers, who arrive at Schiphol Airport for the first time. It is aiming to create a care-free and seamless transport journey from/to Schiphol from their perspective. The project took place in five phases, Research&Analysis phase, Ideation phase, Conceptualisation phase, Embodiment phase and Verification phase. The Research&Analysis phase consisted of desk research, field research and analysis. The Research&Analysis phase revealed the existing ecosystem: a well-developed transport system in the Netherlands, and the potential of the Chinese outbound tourism market. This phase also showed the real experience of first-time passengers: difficulty on getting information, making a choice and feeling the sense of safety. Last but not least, it defined the design goals for the design phases: enable passengers to plan their trips based on the needs easily, and make them feel confident, supportive all the time.The Ideation phase and Conceptualisation phase developed the final concept according to the design brief established at the end of Research&Analysis phase. During this phase, several iteration cycles were conducted to develop and refine the concept. The final design is a digital platform, in the form of a WeChat Mini Program, a light application embedded in WeChat (one of the most frequently used digital product in China). It supports the users from planning their transport before leaving to conducting their transport plan after arrival by fulfilling people’s needs on choosing route, tickets, getting information and finding the right spot for boarding.In the last two phases Embodiment phase and Verification phase, a high-fidelity interactive prototype was built and tested. The user test shows the final design almost meet the design goals. Passengers feel supported during the process of choosing routes and tickets, and feel easier on completing the tasks of finding the spot and getting on the vehicle in an unfamiliar environment. However, the role of the Mini Program in a visitor's journey of visiting the Netherlands is not clearly defined. For the final design, it is recommended to accomplish the service beyond the phone screen. For Schiphol Airport and other transport operators, it is recommended to use WeChat Mini Program as the carrier of service. The final design could be a starting point of the future development of the digital platform as a Mini Program. Those conclusions from Research&Analysis stage might also be a reference for them.Design for Interactio
Probabilistic Testing for Weak Memory Concurrency
No full textThe Probabilistic Concurrency Testing (PCT) algorithm provides theoretical guarantees for the probability of detecting concurrency bugs in a sequential consistency memory model, but its theoretical guarantees do not apply to weak memory concurrency. The weak memory concurrency refers to the modern compiler’s optimization that relaxes the sequential consistency requirements. The PCT approach is based on the sequential consistency interleaving semantics, which does not hold for weak memory concurrency. It is because weak memory concurrency allows additional behaviors that cannot be produced by any interleaving execution.Based on the PCT algorithm transforming the concurrency bug to the ordering constraints(bug depth), this thesis presents Probabilistic Concurrency Testing for Weak Memory (PCTWM) to capture the concurrency behavior in weak memory programs, further revising the notion of the bug depth to the constraints of communication relations between events.We implement both the PCT and PCTWM algorithms on top of the state-of-the-art weak memory testing tool - C11Tester. We empirically evaluate the bug detection ability of the PCTWM on a set of well-known weak memory program benchmarks. Our results show that PCTWM can detect concurrency bugs more frequently than C11Tester.Computer Scienc
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