Regression analysis of clustered interval-censored failure time data

Title from PDF of title page (University of Missouri--Columbia, viewed on July 29, 2013).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. (Tony) Jianguo SunIncludes bibliographical references.Vita.Ph. D. University of Missouri--Columbia 2012."June, 2012"Clustered failure time data occur when the failure times of interest are clustered into small groups, while interval censoring occurs when the event of interest cannot be observed directly and is only known to have occurred over a time interval. Clustered failure time data often arise together with interval-censoring, which leads to the clustered interval-censored failure time data. In this dissertation, we will focus on the regression analysis of such data. In the first part of the dissertation, a regression analysis under a Cox frailty model is discussed by employing a sieve estimation procedure. In particular, a two-step algorithm is developed for the regression parameter estimation and the asymptotic properties of the resulting sieve maximum likelihood estimates are established. The second part of this dissertation proposes an estimating equation-based approach for the additive hazards model. A major advantage of the proposed method is that it does not involve estimation of any baseline hazard function. Both asymptotic and finite sample properties of the proposed estimates of regression parameters are established and the method is illustrated by the data arising from a lymphatic filariasis study. The last part of the dissertation considers the regression analysis of the same type of data in the context of the linear transformation models. For the inference about the regression parameters, a marginal model approach based on within-cluster resampling (WCR) method is proposed and its large sample properties are also established.Includes bibliographical reference

Self-prompted Chain-of-Thought on Large Language Models for Open-domain Multi-hop Reasoning

In open-domain question-answering (ODQA), most existing questions require single-hop reasoning on commonsense. To further extend this task, we officially introduce open-domain multi-hop reasoning (ODMR) by answering multi-hop questions with explicit reasoning steps in open-domain setting. Recently, large language models (LLMs) have found significant utility in facilitating ODQA without external corpus. Furthermore, chain-of-thought (CoT) prompting boosts the reasoning capability of LLMs to a greater extent with manual or automated paradigms. However, existing automated methods lack of quality assurance, while manual approaches suffer from limited scalability and poor diversity, hindering the capabilities of LLMs. In this paper, we propose Self-prompted Chain-of-Thought (SP-CoT), an automated framework to mass-produce high quality CoTs of LLMs, by LLMs and for LLMs. SP-CoT introduces an automated generation pipeline of high quality ODMR datasets, an adaptive sampler for in-context CoT selection and self-prompted inference via in-context learning. Extensive experiments on four multi-hop question-answering benchmarks show that our proposed SP-CoT not only significantly surpasses the previous SOTA methods on large-scale (175B) LLMs, but also nearly doubles the zero-shot performance of small-scale (13B) LLMs. Further analysis reveals the remarkable capability of SP-CoT to elicit direct and concise intermediate reasoning steps by recalling $\sim$50\% of intermediate answers on MuSiQue-Ans dataset.Comment: Accepted by Findings of EMNLP202

Nanofabrication of 3 Dimensional Taper Structures for Nanofocusing Purposes

We have demonstrated experimentally a highly efficient on-chip three-dimensional (3D) linearly tapered metal-insulator-metal (MIM) nanoplasmonic photon compressor (3D NPC) with a final aperture size of 14 x 80nm^2. An optimized and linearly tapered MIM gap plasmon waveguide could theoretically reduce the excessive losses that would occur during nanofocusing processes. This nanofocusing concept has existed for some time, yet researchers had difficulty in realizing structures based on the concept because precisely fabricating the nanoscale waveguides that taper in three dimensions had been very challenging. In simulation study, this approach could enable nanofocusing into a 2 X 5nm^2 area with the coupling loss and maximum E^2 enhancement of 2.5 dB and 3.0x10^4, respectively. We fabricated the 3D NPC on a chip employing electron beam-induced deposition and demonstrated its highly localized light confinement using a two-photon photoluminescence (TPPL) technique. From the TPPL measurements, we experimentally estimated an intensity enhancement of 400 within a 14x80nm^2 crosssectional area and a coupling efficiency of -1.3dB (or 74% transmittance)

Research on vibration displacement test method for large-caliber artillery muzzle

In order to solve the problem of muzzle vibration displacement test of large caliber under high elevation, this paper presents a test method by two high-speed photography. The method fully considers the influence of the muzzle torsion on the measurement results, and accurately obtains the three-dimensional vibration displacement of the muzzle of the large caliber artillery. Finally, through the result analysis, the accuracy of the measurement results can reach 0.1 mm, which shows the advantage of the sub-pixel-based high-speed camera processing method in the muzzle vibration displacement test of the conventional artillery. This paper proposes an innovative test method that accurately measures the vibration displacement of the muzzle using a non-contact method

Further Development of the Improved QMD Model and its Applications to Fusion Reaction near Barrier

The Improved Quantum Molecular Dynamics model is further developed by introducing new parameters in interaction potential energy functional based on Skyrme interaction of SkM$^{*}$ and SLy series. The properties of ground states of selected nuclei can be reproduced very well. The Coulomb barriers for a series of reaction systems are studied and compared with the results of the proximity potential. The fusion excitation functions for a series of fusion reactions are calculated and the results are in good agreement with experimental data.Comment: 17 pages, 10 figures, PRC accepte

Spatial variation of perceived equity and its determinants in a gateway community of Giant Panda National Park, China

Unidad de excelencia María de Maeztu CEX2019-000940-MSocial equity is essential in the governance of protected areas (PAs), as ignoring such consideration can lead to resistance and jeopardize conservation objectives. However, more research is required to understand the spatial heterogeneity of perceived social equity and its underlying spatial factors. Using a survey of 361 respondents, we presented spatial distribution patterns of perceived equity by kernel density estimation (KDE) in Giant Panda National Park, China. The regression analysis showed that local residents who live closer to the PA boundary are more likely to develop negative responses and those who with easy access to tourism spots have more positive procedural and distributional perceptions. Notably, the proximity to the PA authority decreases locals' perceptions of fairness in all aspects, which is potentially due to the opaque participative channels provided by the PA authority. We argue that those spatial differentials in fairness perceptions are driven by the intrinsic discrepancy of biodiversity protection requirements and the unevenly distributed consequences of management policies. Key steps to advance social equity considerations include multi-industry guidance, extending participative channels, and co-producing better compensation plans. Herein, this study appeals to a greater focus on the spatial aspect of social equity issues in PAs

A Novel Reputation Management Mechanism with Forgiveness in P2P File Sharing Networks

AbstractIn peer-to-peer (P2P) file sharing networks, it is common practice to manage each peer using reputation systems. A reputation system systematically tracks the reputation of each peer and punishes peers for malicious behaviors (like uploading bad file, or virus, etc). However, current reputation systems could hurt the normal peers, since they might occasionally make mistakes. Therefore, in this paper, we introduce forgiveness mechanism into the EigenTrust reputation system to reduce such malicious treatments and give them opportunities to gain reputation back. Particularly, we take four motivations (the severity of current offence, the frequency of offences, the compensation and the reciprocity of the offender) into consideration to measure forgiveness. The simulation work shows that the forgiveness model can repair the direct trust breakdown caused by unintentional mistakes and lead to less invalid downloads, which improves the performance of P2P file sharing systems