Outlier Detection for Cognitive Diagnosis Models

HonorsStatisticsUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/169432/1/xinyuez.pd

An Exploration of MALL for Enhancing College Students’ Oral English Proficiency

Mobile-Assisted Language Learning (MALL) has emerged as a promising tool within language education, presenting distinctive prospects for enhancing oral proficiency. This paper starts off by analyzing the current status of oral English learning among college-level English as a Foreign Language (EFL) learners in China in such aspects as syllabus emphasis, classroom dynamics, examination focus, and language anxiety. It then shifts focus to MALL and its potential to enhance students’ English speaking skills, particularly in a flexible and self-paced manner. Through a synthesis of existing studies and the proposition of effective pedagogical strategies, this paper seeks to elucidate the transformative capacity of MALL in reshaping oral English learning experiences within higher education contexts. Furthermore, practical recommendations for language educators, curriculum designers, and college students are provided to adapt oral English teaching methodologies, thereby fostering a more efficient and learner-centered language learning environment

The Impact of Time Delay in a Tumor Model

We consider a free boundary tumor growth model with a time delay in cell proliferation and study how time delay affects the stability and the size of the tumor. The model consists of a coupled system of an elliptic equation, a parabolic equation and an ordinary differential equation to describe the cell location under the presence of time delay, with the tumor boundary as a free boundary. A parameter $\mu$ in the model is proportional to the “aggressiveness” of the tumor. It is proved that there exists a unique classical radially symmetric stationary solution $(\sigma_*,p_*,R_*)$ which is stable for any $\mu\u3e0$ with respect to all radially symmetric perturbations [S. Xu, Q. Zhou, and M. Bai, Qualitative analysis of a time-delayed free boundary problem for tumor growth under the action of external inhibitors]. However, under non-radially symmetric perturbations, we prove that there exists a critical number $\mu_*$ such that if $\mu\mu_*$ then the stationary solution is unstable. It is actually unrealistic to expect the problem to be stable for large tumor aggressiveness parameter, therefore our result is more reasonable. Furthermore, it is also proved by the authors that adding the time delay in the model would result in a larger tumor, and if $\mu$ is larger, then the time delay would have a greater impact on the size of the tumor

Generalization of nonlocally related partial differential equation systems: unknown symmetric properties and analytical solutions

Symmetry, which describes invariance, is an eternal concern in mathematics and physics, especially in the investigation of solutions to the partial differential equation (PDE). A PDE's nonlocally related PDE systems provide excellent approaches to search for various symmetries that expand the range of its known solutions. They composed of potential systems based on conservation laws and inverse potential systems (IPS) based on differential invariants. Our study is devoted to generalizing their construction and application in three-dimensional circumstances. Concretely, the potential of the algebraic gauge-constrained potential system is simplified without weakening its solution space. The potential system is extended via nonlocal conservation laws and double reductions. Afterwards, nonlocal symmetries are identified in the IPS.\@ The IPS is extended by the solvable Lie algebra and type \Rmnum{2} hidden symmetries. Besides, systems among equations can be connected via Cole-Hopf transformation.\@ Ultimately, established and extended systems embody rich symmetric properties and unprecedented analytical solutions, and may even further facilitate general coordinate-independent analysis in qualitative, numerical, perturbation, etc., this can be illustrated by several Burgers-type equations

Imagens do oriente em contos e lendas de Macau

Mestrado em Línguas, Literaturas e CulturasA chegada a Macau dos navegadores portugueses, em meados do séc. XVI, lançou as bases de quase cinco séculos de contacto ininterrupto entre o Ocidente e o Oriente. Macau é, muitas vezes, caracterizado como um ponto de encontro, de coexistência harmoniosa e de intercâmbio multicultural (principalmente entre a cultura oriental e portuguesa). Existe variada literatura que tem Macau como objeto de reflexão, nomeadamente no subsistema infantojuvenil. Este trabalho pretende, por meio de uma análise sistemática de uma coletânea de contos infantojuvenis de temática oriental, da autoria de Alice Vieira e com ilustrações de Alain Corbel, caracterizar as representações do Oriente que surgem no contexto da literatura portuguesa contemporânea para a infância, refletindo sobre as imagens mais recorrentes e as simbologias mais significativas.The arrival of Portuguese Navigators in Macau in the middle of the 16th century marked the start of almost five centuries of continuous contact between the Orient and Western Europe. Macau is often characterized as a meeting point of cultures, harmonious co-existence and intercultural exchange (particularly between Oriental and Portuguese culture). There is a wide range of publications about Macau, especially in the area of children ’ s literature. The aim of this dissertation is to carry out an in-depth analysis of a collection of stories for young adults written by Alice Vieira which include reference to the Orient. They contain representations of the Orient within the context of contemporary Portuguese children ’ s literature and reflect some of the most common depictions and significant symbols of the local culture

Research on the Integrated Development Mode of Pastoral Agriculture

As an emerging thing different from traditional agriculture, the pastoral complex covers a wide range. This paper mainly designs the agricultural landscape under the concept of the pastoral complex to create a more attractive park, attract more tourists to travel and consume here, develop the local economy, improve local income, and promote the implementation of the rural revitalization strategy in the local area. This paper combines theory with practice, broadens the application methods and theoretical framework of the design of rural complexes, has specific reference value for the research of the design of rural complexes, is conducive to the construction of rural landscapes and the protection of rural ecology, arouses people’s re-examination of the construction of rural landscape, and has specific theoretical and practical significance for the development of rural landscape and the implementation of rural revitalization strategy

Exploring f(T)f(T) Gravity via strongly lensed fast radio bursts

This study aims to investigate the strong gravitational lensing effects in $f(T)$ gravity. We present the theoretical analytic expressions for the lensing effects in $f(T)$ gravity, including deflection angle, magnification, and time delay. On this basis, we also take the plasma lensing effect into consideration. We compare the lensing effects between the General Relativity in a vacuum environment and the $f(T)$ gravity in a plasma environment. From a strongly lensed fast radio burst, the results indicate that in a plasma environment, General Relativity and $f(T)$ gravity can generate indistinguishable image positions, but the magnification and time delay on these positions are significantly different, which can be distinguished by current facilities in principle. Therefore, the discrepancies between observational results and theoretical expectations can serve as clues for a modified gravity theory and provide constraints on $f(T)$ gravity