743 research outputs found

    Phonon anharmonicity of rutile TiO_2 studied by Raman spectrometry and molecular dynamics simulations

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    Raman spectra of rutile titanium dioxide (TiO_2) were measured at temperatures from 100 to 1150 K. Each Raman mode showed unique changes with temperature. Beyond the volume-dependent quasiharmonicity, the explicit anharmonicity was large. A new method was developed to fit the thermal broadenings and shifts of Raman peaks with a full calculation of the kinematics of three-phonon and four-phonon processes, allowing the cubic and quartic components of the anharmonicity to be identified for each Raman mode. A dominant role of phonon-phonon kinematics on phonon shifts and broadenings is reported. Force-field molecular dynamics calculations with the Fourier-transformed velocity autocorrelation method were also used to perform a quantitative study of anharmonic effects, successfully accounting for the anomalous phonon anharmonicity of the B_1_(g) mode

    Construction of Big Data Analysis Platform for College Students’ Sports Training Driven by Wireless Communication Network

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    College students’ physical training is an important aspect of their studies and lives. In light of the existing issues with the accuracy of the physical training evaluation index for college students and other issues. Based on the theory of wireless communication networks, model definition and stability analysis methods are used to optimize the original model. The optimization model of a wireless communication network is obtained by considering the data output control theory, trained by college students. This model can analyze the big data of college students’ physical training and construct the corresponding data platform. Through calculations, the rules for data changes under different indicators can be obtained. Finally, the accuracy of the optimized model is verified by comparing it with the original model. Related studies show that the variable parameters in the control system include model parameters, network upper limit, and corresponding control system parameters. On the whole, the model parameters exhibit a consistent trend of change, while the upper limit of the network displays a characteristic three-stage linear pattern. The control system first increases rapidly and then exhibits a gradual decline in exponential function type. The control system and the switching system can be switched using model calculations. The two different change curves exhibit obvious symmetry characteristics when influenced by the output times. It shows that the two change systems have opposite effects on the model, and the overall volatility is relatively high. The wireless communication network model can analyze and build a platform for collecting college students’ sports training data. According to the model calculation, it can be seen that the changes in different indexes exhibit clear linear characteristics. Among them, the concepts of sports, personalized training, and basic training show linearly increasing changes. However, the training structure and content exhibit a typical linear decline. Finally, the advantages of the wireless communication network model are illustrated with the experimental data. This study can provide guidance and ideas for the construction of a data platform for college students’ physical training

    Evaluation of Plant Metaphors in A Dream of Red Mansions

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    This work attempts to evaluate the plant metaphors used in A Dream of Red Mansions, aiming at: 1) Identifying the metaphorical expressions associated with plant used in the book; 2) finding out the correlation between plant metaphors and their evaluation; 3) exploring the experiential bases of the operational model of abstract reason in Chinese embodied in A Dream of Red Mansions, achieved via metaphor mapping the concrete concept – PLANT onto the abstract concept? How is it achieved? The results indicate that the cognitive approach to metaphor postulates that all conventional conceptual metaphors are grounded in our bodily and physical experience. Once a metaphorical mapping is set up, it will impose its structure on real life through the creation of new correspondences in experience. If the metaphor is the message, the conceptual metaphor provides a method of representation through which we may identify its salient features. As a result, the evaluation of the plant metaphors can contribute significantly to our understanding of the plant metaphors within Chinese culture.Key words: Plant metaphors; Cognitive analysis; Experiential groundin

    Cognitive Analysis of A Dream of Red Mansions: A Case of “Root” Conceptual Metaphor

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    The thesis is an analysis of the samples of “root” conceptual metaphor taken from A Dream of Red Mansions. Special attention has been paid to the mapping process from the source domain to the target domain, and also to the experiential grounding of those metaphorical expressions and to their realizations in A Dream of Red Mansions.Key words: A Dream of Red Mansions; Plant Metaphors; Cognitive Analysis; Roo

    Large-scale consensus with endo-confidence under probabilistic linguistic circumstance and its application

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    In real decision-making problems, decision makers (DMs) usually select the most potential project from several ones. However, they unconsciously show different confidence levels in decisionmaking process because they come from various backgrounds and have different experiences, etc., which affects the decision results. Moreover, the probabilistic linguistic term set, which not only includes the linguistic expressions used by DMs in their daily life but also contains the probability for each linguistic term, can well portray the real perceptions of DMs for the projects. Furthermore, large-scale consensus has gradually been a popular way to effectively solve complex decision-making problems. To sum up, in this paper, we are dedicated to constructing a largescale consensus model considering the confidence levels of DMs under probabilistic linguistic circumstance. Firstly, the endo-confidence is defined and measured by DM’s probabilistic linguistic information. Then, the DMs are clustered according to the similarities of both evaluation information and the endo-confidence levels. Both evaluation of the non-consensus cluster and evaluation integrated by the clusters with higher endo-confidence level than this non-consensus cluster are used as the reference to adjust its evaluation information. Then, a case study and the comparative analysis are carried out. Finally, some conclusions and future work are given

    Fault detection in discrete dynamic systems with uncertainty based on interval optimization

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    The imprecision and the uncertainty of many systems can be expressed with interval models. This paper presents a method for fault detection in uncertain discrete dynamic systems. First, the discrete dynamic system with uncertain parameters is formulated as an interval optimization model. In this model, we also assume that there are some errors of observation values of the inputs/outputs. Then, M. HladĂ­k's newly proposed algorithm is exploited for this model. Some numerical examples are also included to illustrate the method efficiency
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