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Finite element modeling assumptions impact on seismic response demands of MRF-buildings 被引量:4
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作者 Shehata E Abdel Raheem Ahmed K Abdel Zaher Ahmed MA Taha 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2018年第4期821-834,共14页
Recent seismic events have raised concerns over the safety and vulnerability of reinforced concrete moment resisting frame "RC-MRF" buildings. The seismic response of such buildings is greatly dependent on the compu... Recent seismic events have raised concerns over the safety and vulnerability of reinforced concrete moment resisting frame "RC-MRF" buildings. The seismic response of such buildings is greatly dependent on the computational tools used and the inherent assumptions in the modelling process. Thus, it is essential to investigate the sensitivity of the response demands to the corresponding modelling assumption. Many parameters and assumptions are justified to generate effective structural finite element(FE) models of buildings to simulate lateral behaviour and evaluate seismic design demands. As such, the present study focuses on the development of reliable FE models with various levels of refinement. The effects of the FE modelling assumptions on the seismic response demands on the design of buildings are investigated. the predictive ability of a FE model is tied to the accuracy of numerical analysis; a numerical analysis is performed for a series of symmetric buildings in active seismic zones. The results of the seismic response demands are presented in a comparative format to confirm drift and strength limits requirements. A proposed model is formulated based on a simplified modeling approach, where the most refined model is used to calibrate the simplified model. 展开更多
关键词 RC-MRF buildings design codes provisions seismic design finite element modeling modeling assumptions response demands
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Unsuspected implications arising from assumptions in simulations: insights from recasting a forest growth model in system dynamics 被引量:2
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《Forestry Studies in China》 CAS 2014年第1期-,共10页
Background:Familiarity with a simulation platform can seduce modellers into accepting untested assumptions for convenience of implementation.These assumptions may have consequences greater than commonly suspected,and ... Background:Familiarity with a simulation platform can seduce modellers into accepting untested assumptions for convenience of implementation.These assumptions may have consequences greater than commonly suspected,and it is important that modellers remain mindful of assumptions and remain diligent with sensitivity testing.Methods:Familiarity with a technique can lead to complacency,and alternative approaches and software can reveal untested assumptions.Visual modelling environments based on system dynamics may help to make critical assumptions more evident by offering an accessible visual overview and empowering a focus on representational rather than computational efficiency.This capacity is illustrated using a cohort-based forest growth model developed for mixed species forest.Results:The alternative model implementation revealed that untested assumptions in the original model could have substantial influence on simulated outcomes.Conclusions:An important implication is that modellers should remain conscious of all assumptions,consider alternative implementations that reveal assumptions more clearly,and conduct sensitivity tests to inform decisions. 展开更多
关键词 Forest growth model Validity of assumptions Visual modelling environment FORTRAN SIMILE System dynamics Swindle
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APPROXIMATION THEORY OF THREE DIMENSIONAL ELASTIC PLATES AND ITS BOUNDARY CONDITIONS WITHOUT USING KIRCHHOFF-LOVE ASSUMPTIONS
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作者 钱伟长 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1995年第3期203-224,共16页
The classical small deflection theory of elastic plates id based on the Kirchhoff-Lore assumptions ̄[1,2].Ther are used on the basis of the thinness of plate and the smallness of deflection.In terms of Cartesian tens... The classical small deflection theory of elastic plates id based on the Kirchhoff-Lore assumptions ̄[1,2].Ther are used on the basis of the thinness of plate and the smallness of deflection.In terms of Cartesian tensor coordinates x_i(i=0, 12)these basic assumptions are:(1)the transversal normal strain may be neglected i.e._(00)=0;(2)the transversal shear strain may be neglected i.e.e_(0α)=0(α= 1, 2)(3)the transversal normal stress may be neglected i.e.. σ_(00)=0 .In classical theory of elastic plates,the strain-displacement relations and the corresponding stress-displacement relations are established on the basis of these assumptions. And the equations of the classical theory for a set of undetermined quantities defined on the middle surface are established through integrating the three dimensional equations of equilibrium of stress over the thickness.In the previous papers ̄[3,4,5],an approximation theory is given on the basis of Ihree dimensional theory of elastic plates without using Kirchhoff-Love assumptions。However,no uniqueness study is given,and also the boundary conditions have never been studied. In this paper.the same problems are studied on the basis of generalizedvariational principle of the three dimensional theory of elastic bodies ̄[6].The stationary conditions of variation give an unique and complete set of field equations and the related boundary conditions for the approximation theory.In this paper,the first order approximation theory is studied in detail. 展开更多
关键词 three dimensional elastic plates. Kirchhoff-Love assumptions.Cartesian TENSOR COORDINATES
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Preliminary Report on the Theory of Elastic Circular Plate with no Kirchhoff-Love Assumptions
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作者 钱伟长 茹学萍 《Advances in Manufacturing》 SCIE CAS 1997年第1期1-14,共14页
In this paper, the theory of elastic circular plate with no classical Kirchhoff-Love assumptions is established on the basis of a previous paper. In this theory, no classical Kirchhoff-Love assumptions are pre-assumed... In this paper, the theory of elastic circular plate with no classical Kirchhoff-Love assumptions is established on the basis of a previous paper. In this theory, no classical Kirchhoff-Love assumptions are pre-assumed and the axial symmetrical analytic solution of fixed circular plate under the action of uniform pressure is obtained. Comparison of this solution and the known classical solution shows that this new solution agrees better than classical solution with the experiment measurement.This gives also the quantitative effect of the thickness on the deflection of circular plate with moderate thickness. 展开更多
关键词 theory of elasticity 3-D theory of small deflection of circular plate Kirchhoff-Love assumptions
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The Development of Managerial Assumptions about Human Nature in China: A Tale from Quanzhou
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作者 Yi-BingZhang Siew-Huat Kong 《Cultural and Religious Studies》 2017年第12期703-716,共14页
How managers’ knowledge and beliefs of human nature are formed and manifested has not been fully explored in the context of Chinese society going through rapid transition nowadays. And yet this could be the missing l... How managers’ knowledge and beliefs of human nature are formed and manifested has not been fully explored in the context of Chinese society going through rapid transition nowadays. And yet this could be the missing link in our discourse on Chinese managers. Based on a qualitative study conducted in Quanzhou, China, this study found certain assumptions of human nature that are deeply embedded in their managers’ intellectual framework, which in turn guide their managerial behaviours in diverse aspects of their work. Unless the managers are prepared to examine their own thoughts, especially those at the sub-conscious level, they would remain prisoners of their own thought, and all the efforts directed at transforming managers would be seriously compromised. 展开更多
关键词 assumptions China human nature manager’s intellectual framework Quanzhou
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Formally Deriving the Third Newton’s Law from a Pair of Nontrivial Assumptions in a Formal Axiomatic Theory “Sigma-V” 被引量:1
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作者 Vladimir O. Lobovikov 《Journal of Applied Mathematics and Physics》 2022年第5期1561-1586,共26页
The article is devoted to hitherto never undertaken applying an almost unknown logically formalized axiomatic epistemology-and-axiology system called “Sigma-V” to the Third Newton’s Law of mechanics. The author has... The article is devoted to hitherto never undertaken applying an almost unknown logically formalized axiomatic epistemology-and-axiology system called “Sigma-V” to the Third Newton’s Law of mechanics. The author has continued investigating the extraordinary (paradigm-breaking) hypothesis of formal-axiological interpreting Newton’s mathematical principles of natural philosophy and, thus, has arrived to discrete mathematical modeling a system of formal axiology of nature by extracting and systematical studying its proper algebraic aspect. Along with the proper algebraic machinery, the axiomatic (hypothetic-deductive) method is exploited in this investigation systematically. The research results are the followings. 1) The Third Newton’s Law of mechanics has been modeled by a formal-axiological equation of two-valued algebraic system of metaphysics as formal axiology. (Precise defining the algebraic system is provided.) The formal-axiological equation has been established (and examined) in this algebraic system by accurate computing compositions of relevant evaluation-functions. Precise tabular definitions of the evaluation-functions are given. 2) The wonderful formula representing the Third Newton’s Law (in the relevant physical interpretation of the formal theory Sigma-V) has been derived logically in Sigma-V from the presumption of a-priori-ness of knowledge. A precise axiomatic definition of the nontrivial notion “a-priori-ness of knowledge” is given. The formal derivation is implemented in strict accordance with the rigor standard of D. Hilbert’s formalism;hence, checking the formal derivation submitted in this article is not a difficult task. With respect to proper theoretical physics, the formal inference is a nontrivial scientific novelty which has not been discussed and published elsewhere yet. 展开更多
关键词 Third Law of Newton’s Mechanics Logically Formalized Axiomatic Theory Σ-V Two Valued Algebraic System of Metaphysics as Formal Axiology A-Priori Knowledge Formal Derivation from Assumption
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A FURTHER STUDY OF THE THEORY OF ELASTIC CIRCULAR PLATES WITH NON-KIRCHHOFF-LOVE ASSUMPTIONS
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作者 钱伟长 茹学萍 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1995年第2期101-113,共13页
Based on the general theory of elastic plates which abandons Kirchhoff-Loveassunption in the classical theory. this paper establishes a first order approximationtheory of elastic circular plates with non-Kirchhoff-Lov... Based on the general theory of elastic plates which abandons Kirchhoff-Loveassunption in the classical theory. this paper establishes a first order approximationtheory of elastic circular plates with non-Kirchhoff-Love assumption, and presents ananalytic solution to the axisymmetric problem of elastic circular plates with clampedboundary under uniformly distributed load. By comparing with the classical solution ofthe thin circular plates, it is verified that the new solution is closer to the experimentresults than the classical solution. By virtue of the new theory. the influence of thediameter-to=thickness ratio upon the precision of the classical theory is examined. 展开更多
关键词 ELASTICITY circular plates Kirchhoff-Love assumption
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A Comparison of Closed World Assumptions
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作者 沈一栋 《Journal of Computer Science & Technology》 SCIE EI CSCD 1992年第3期243-246,共4页
In this paper, we introduce a notion of the family of closed world assumptions and compare several well-known closed world approaches in the family to the extent to which an incomplete database is com- pleted.
关键词 DB A Comparison of Closed World assumptions World
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Thermal behavior of friction clutch disc based on uniform pressure and uniform wear assumptions 被引量:9
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作者 Oday I.ABDULLAH Josef SCHLATTMANN 《Friction》 CSCD 2016年第3期228-237,共10页
关键词 dry friction clutch thermal analysis finite element analysis uniform wear assumption uniform pressure assumption
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Tightly Secure Public-Key Cryptographic Schemes from One-More Assumptions
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作者 Ge Wu Jian-Chang Lai +2 位作者 Fu-Chun Guo Willy Susilo Fu-Tai Zhang 《Journal of Computer Science & Technology》 SCIE EI CSCD 2019年第6期1366-1379,共14页
A tightly secure cryptographic scheme refers to a construction with a tight security reduction to a hardness assumption,where the reduction loss is a small constant.A scheme with tight security is preferred in practic... A tightly secure cryptographic scheme refers to a construction with a tight security reduction to a hardness assumption,where the reduction loss is a small constant.A scheme with tight security is preferred in practice since it could be implemented using a smaller parameter to improve efficiency.Recently,Bader et al.(EUROCRYPT 2016)have proposed a comprehensive study on the impossible tight security reductions for certain(e.g.,key-unique)public-key cryptographic schemes in the multi-user with adaptive corruptions(MU-C)setting built upon non-interactive assumptions.The assumptions of one-more version,such as one-more computational Diffie-Hellman(n-CDH),are variants of the standard assumptions and have found various applications.However,whether it is possible to have tightly secure key-unique schemes from the one-more assumptions or the impossible tight reduction results also hold for these assumptions remains unknown.In this paper,we give affirmative answers to the above question,i.e.,we can have efficient key-unique public-key cryptographic schemes with tight security built upon the one-more assumptions.Specifically,we propose a digital signature scheme and an encryption scheme,both of which are key-unique and have tight MU-C security under the one-more computational Diffie-Hellman(n-CDH)assumption.Our results also reflect from another aspect that there indeed exists a gap between the standard assumptions and their one-more version counterparts. 展开更多
关键词 public-key CRYPTOGRAPHY MULTI-USER setting TIGHT security one-more ASSUMPTION
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Classification of knowledge graph completeness measurement techniques
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作者 ZHANG Ying XIAO Gang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2024年第1期154-162,共9页
At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissi... At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissions and errors.Quality assessment and control,as an important means to ensure the quality of knowledge,can make the applications based on knowledge graphs more complete and more accurate by reasonably assessing the knowledge graphs and fixing and improving the quality problems at the same time.Therefore,as an indispensable part of the knowledge graph construction process,the results of quality assessment and control determine the usefulness of the knowledge graph.Among them,the assessment and enhancement of completeness,as an important part of the assessment and control phase,determine whether the knowledge graph can fully reflect objective phenomena and reveal potential connections among entities.In this paper,we review specific techniques of completeness assessment and classify completeness assessment techniques in terms of closed world assumptions,open world assumptions,and partial completeness assumptions.The purpose of this paper is to further promote the development of knowledge graph quality control and to lay the foundation for subsequent research on the completeness assessment of knowledge graphs by reviewing and classifying completeness assessment techniques. 展开更多
关键词 quality assessment completeness assessment closed world assumptions open world assumption partial completeness assumption
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Zeno and the Wrong Understanding of Motion—A Philosophical-Mathematical Inquiry into the Concept of Finitude as a Peculiarity of Infinity
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作者 Andreas Herberg-Rothe 《Journal of Applied Mathematics and Physics》 2024年第3期912-929,共18页
In contrast to the solutions of applied mathematics to Zeno’s paradoxes, I focus on the concept of motion and show that, by distinguishing two different forms of motion, Zeno’s apparent paradoxes are not paradoxical... In contrast to the solutions of applied mathematics to Zeno’s paradoxes, I focus on the concept of motion and show that, by distinguishing two different forms of motion, Zeno’s apparent paradoxes are not paradoxical at all. Zeno’s paradoxes indirectly prove that distances are not composed of extensionless points and, in general, that a higher dimension cannot be completely composed of lower ones. Conversely, lower dimensions can be understood as special cases of higher dimensions. To illustrate this approach, I consider Cantor’s only apparent proof that the real numbers are uncountable. However, his widely accepted indirect proof has the disadvantage that it depends on whether there is another way to make the real numbers countable. Cantor rightly assumes that there can be no smallest number between 0 and 1, and therefore no beginning of counting. For this reason he arbitrarily lists the real numbers in order to show with his diagonal method that this list can never be complete. The situation is different if we start with the largest number between 0 and 1 (0.999…) and use the method of an inverted triangle, which can be understood as a special fractal form. Here we can construct a vertical and a horizontal stratification with which it is actually possible to construct all real numbers between 0 and 1 without exception. Each column is infinite, and each number in that column is the starting point of a new triangle, while each row is finite. Even in a simple sine curve, we experience finiteness with respect to the y-axis and infinity with respect to the x-axis. The first parts of this article show that Zeno’s assumptions contradict the concept of motion as such, so it is not surprising that this misconstruction leads to contradictions. In the last part, I discuss Cantor’s diagonal method and explain the method of an inverted triangle that is internally structured like a fractal by repeating this inverted triangle at each column. The consequence is that we encounter two very different methods of counting. Vertically it is continuous, horizontally it is discrete. While Frege, Tarski, Cantor, Gödel and the Vienna Circle tried to derive the higher dimension from the lower, a procedure that always leads to new contradictions and antinomies (Tarski, Russell), I take the opposite approach here, in which I derive the lower dimension from the higher. This perspective seems to fail because Tarski, Russell, Wittgenstein, and especially the Vienna Circle have shown that the completeness of the absolute itself is logically contradictory. For this reason, we agree with Hegel in assuming that we can never fully comprehend the Absolute, but only its particular manifestations—otherwise we would be putting ourselves in the place of the Absolute, or even God. Nevertheless, we can understand the Absolute in its particular expressions, as I will show with the modest example of the triangle proof of the combined horizontal and vertical countability of the real numbers, which I developed in rejection of Cantor’s diagonal proof. . 展开更多
关键词 Zeno False assumptions about Motion Finitude INFINITY Cantor’s Diagonal Method Inverted Triangle as a Different Method Vertical and Horizontal Dimensions Quantum Theory Relativity of Space and Time Depending on Velocity
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Changes in the Boreal Summer Intraseasonal Oscillation under Global Warming in CMIP6 Models
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作者 Zhefan GAO Chaoxia YUAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第10期1984-1998,共15页
Changes in the activities of the Boreal Summer Intraseasonal Oscillation(BSISO)at the end of 21st century under the SSP5-8.5 scenario are assessed by adopting 17 CMIP6 models and the weak-temperature-gradient assumpti... Changes in the activities of the Boreal Summer Intraseasonal Oscillation(BSISO)at the end of 21st century under the SSP5-8.5 scenario are assessed by adopting 17 CMIP6 models and the weak-temperature-gradient assumption.Results show that the intraseasonal variations become more structured.The BSISO-related precipitation anomaly shows a larger zonal scale and propagates further northward.However,there is no broad agreement among models on the changes in the eastward and northward propagation speeds and the frequency of individual phases.In the western North Pacific(WNP),the BSISO precipitation variance is significantly increased,at 4.62%K^(−1),due to the significantly increased efficiency of vertical moisture transport per unit of BSISO apparent heating.The vertical velocity variance is significantly decreased,at−3.51%K^(−1),in the middle troposphere,due to the significantly increased mean-state static stability.Changes in the lower-level zonal wind variance are relatively complex,with a significant increase stretching from the northwestern to southeastern WNP,but the opposite in other regions.This is probably due to the combined impacts of the northeastward shift of the BSISO signals and the reduced BSISO vertical velocity variance under global warming.Changes in strong and normal BSISO events in the WNP are also compared.They show same-signed changes in precipitation and large-scale circulation anomalies but opposite changes in the vertical velocity anomalies.This is probably because the precipitation anomaly of strong(normal)events changes at a rate much larger(smaller)than that of the meanstate static stability,causing enhanced(reduced)vertical motion. 展开更多
关键词 Boreal Summer Intraseasonal Oscillation global warming CMIP6 weak-temperature-gradient assumption
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Heterophilic Graph Neural Network Based on Spatial and Frequency Domain Adaptive Embedding Mechanism
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作者 Lanze Zhang Yijun Gu Jingjie Peng 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1701-1731,共31页
Graph Neural Networks(GNNs)play a significant role in tasks related to homophilic graphs.Traditional GNNs,based on the assumption of homophily,employ low-pass filters for neighboring nodes to achieve information aggre... Graph Neural Networks(GNNs)play a significant role in tasks related to homophilic graphs.Traditional GNNs,based on the assumption of homophily,employ low-pass filters for neighboring nodes to achieve information aggregation and embedding.However,in heterophilic graphs,nodes from different categories often establish connections,while nodes of the same category are located further apart in the graph topology.This characteristic poses challenges to traditional GNNs,leading to issues of“distant node modeling deficiency”and“failure of the homophily assumption”.In response,this paper introduces the Spatial-Frequency domain Adaptive Heterophilic Graph Neural Networks(SFA-HGNN),which integrates adaptive embedding mechanisms for both spatial and frequency domains to address the aforementioned issues.Specifically,for the first problem,we propose the“Distant Spatial Embedding Module”,aiming to select and aggregate distant nodes through high-order randomwalk transition probabilities to enhance modeling capabilities.For the second issue,we design the“Proximal Frequency Domain Embedding Module”,constructing adaptive filters to separate high and low-frequency signals of nodes,and introduce frequency-domain guided attention mechanisms to fuse the relevant information,thereby reducing the noise introduced by the failure of the homophily assumption.We deploy the SFA-HGNN on six publicly available heterophilic networks,achieving state-of-the-art results in four of them.Furthermore,we elaborate on the hyperparameter selection mechanism and validate the performance of each module through experimentation,demonstrating a positive correlation between“node structural similarity”,“node attribute vector similarity”,and“node homophily”in heterophilic networks. 展开更多
关键词 Heterophilic graph graph neural network graph representation learning failure of the homophily assumption
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Training for Vessel Collision Prevention:Circumstances and Causes of Near-Miss Incidents
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作者 Yoshiaki Kunieda Akihiro Nunome +1 位作者 Kotaro Ito Naruphun Chotechaung 《Journal of Traffic and Transportation Engineering》 2024年第6期264-275,共12页
Among the near-miss incidents related to the operation of training ship of the JMETS(Japan Agency of Maritime Education and Training for Seafarers),three characteristic cases were analyzed,extracting their circumstanc... Among the near-miss incidents related to the operation of training ship of the JMETS(Japan Agency of Maritime Education and Training for Seafarers),three characteristic cases were analyzed,extracting their circumstances and near-miss factors.Based on the results of these analyses,measures to prevent vessel collisions were studied,from which we proposed collision prevention training.The training entails(1)lookout training,(2)navigation planning training,(3)resource management training,and(4)false assumption prevention training.In future research,we aim to verify the effectiveness of the proposed training,improve the training’s effectiveness,and contribute to the development of effective anti-collision support devices. 展开更多
关键词 Collision prevention near-miss incidents collision prevention measures false assumption
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Textbook Evaluation
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作者 王熙 马朝光 吴彩灵 《海外英语》 2015年第11期105-106,168,共3页
More and more researchers realized that what happened in classrooms was deeply influenced by the social and culturalcontexts outside and various articles and researches have been written or done to address this proble... More and more researchers realized that what happened in classrooms was deeply influenced by the social and culturalcontexts outside and various articles and researches have been written or done to address this problem.The essay evaluates a teach-ing material from the perspectives of culture,society and politics by suggesting a few adaptations to the teaching material to make itmore culturally appropriate for Chinese learners. 展开更多
关键词 TEXTBOOK EVALUATION COMMUNICATIVE competences CULTURAL assumptions LANGUAGE TEACHING
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Statistical Research on S-Wave Incident Angle 被引量:24
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作者 Jin Xing and Liao ZhenpengInstitute of Engineering Mechanics,SSB,Harbin,Heilongjiang 150080,China 《Earthquake Research in China》 1994年第1期124-134,共11页
In this paper,the following assumptions are made:1) seismic source is a point one;2) the near-fieid.seismic waves are body ones:3) the medium of the earth is a half-space which is homogeneous and elastic.Yccording to ... In this paper,the following assumptions are made:1) seismic source is a point one;2) the near-fieid.seismic waves are body ones:3) the medium of the earth is a half-space which is homogeneous and elastic.Yccording to the above-mentioned assumptions,this paper obtains a theoretical formula to estimate S-wave incident angle by using the record of strong ground motion.During the process of calculations,the paper also presents a method of getting in-plane and inti-plane motions from the record of strong ground motion.By making use of 214 records of strong ground motion in the western America,this paper gives a statistical relation among S-wave incident angle,epicentral distance and frequency.The results show that the average value of S-wave incident angle is about 57,and has little to do with the epicentral distance. 展开更多
关键词 RECORD INCIDENT assumptions Angle GETTING COORDINATES MAGNITUDE deviation extreme mentioned
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The penetrating depth analysis of Lunar Penetrating Radar onboard Chang'e-3 rover 被引量:6
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作者 Shu-Guo Xing Yan Su +4 位作者 Jian-Qing Feng Shun Dai Yuan Xiao Chun-Yu Ding Chun-Lai Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2017年第5期79-90,共12页
Lunar Penetrating Radar(LPR) has successfully been used to acquire a large amount of scientific data during its in-situ detection. The analysis of penetrating depth can help to determine whether the target is within... Lunar Penetrating Radar(LPR) has successfully been used to acquire a large amount of scientific data during its in-situ detection. The analysis of penetrating depth can help to determine whether the target is within the effective detection range and contribute to distinguishing useful echoes from noise.First, this study introduces two traditional methods, both based on a radar transmission equation, to calculate the penetrating depth. The only difference between the two methods is that the first method adopts system calibration parameters given in the calibration report and the second one uses high-voltage-off radar data. However, some prior knowledge and assumptions are needed in the radar equation and the accuracy of assumptions will directly influence the final results. Therefore, a new method termed the Correlation Coefficient Method(CCM) is provided in this study, which is only based on radar data without any a priori assumptions. The CCM can obtain the penetrating depth according to the different correlation between reflected echoes and noise. To be exact, there is a strong correlation in the useful reflected echoes and a random correlation in the noise between adjacent data traces. In addition, this method can acquire a variable penetrating depth along the profile of the rover, but only one single depth value can be obtained from traditional methods. Through a simulation, the CCM has been verified as an effective method to obtain penetration depth. The comparisons and analysis of the calculation results of these three methods are also implemented in this study. Finally, results show that the ultimate penetrating depth of Channel 1 and the estimated penetrating depth of Channel 2 range from 136.9 m to 165.5 m(ε_r = 6.6) and from 13.0 m to 17.5 m(ε_r = 2.3), respectively. 展开更多
关键词 penetrating Lunar rover lunar assumptions calibration ultimate traces Correlation verified
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Approximate analytical solution for seepage field of drained tunnel in vertically stratified phreatic aquifer 被引量:1
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作者 MENG Wei HE Chuan +5 位作者 WU Fang-yin YANG Wen-bo KOU Hao ZHOU Zi-han GUO De-ping MENG Hai-long 《Journal of Mountain Science》 SCIE CSCD 2022年第5期1437-1455,共19页
To explore the water table and water inflow after tunnel excavation in a vertically stratified phreatic aquifer,approximate analytical solutions for the steady-state water table and water inflow of a drained tunnel in... To explore the water table and water inflow after tunnel excavation in a vertically stratified phreatic aquifer,approximate analytical solutions for the steady-state water table and water inflow of a drained tunnel in a vertically stratified phreatic aquifer were obtained based on the Dupuit assumptions and the integral method.By comparing the approximate analytical solutions with numerical solutions,it was found that the relative error of the approximate analytical solution for the water table elevation is less than 10%,and the relative error of the approximate analytical solution for the water inflow is approximately 25%.The sources of the above errors are as follows:(1)At the lateral boundary of water replenishment,the water surface should be tangent to the horizontal line,but the water surface for the approximate analytical solutions has a gradient.(2)At the vertical boundaries near the tunnel,the total head is variable,but the total head for the approximate analytical solutions is assumed to be constant.(3)The Dupuit assumptions are applied in the flow domain near the tunnel.Although the relative errors of the approximate analytical solutions for the water table elevation and water inflow are evident,the lowered water table is reflected in the approximate analytical solutions. 展开更多
关键词 Dupuit assumptions Water table Water inflow Tunnel engineering Equipotential line Integral method
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SOLVABILITY RESULTS OF A CONDITIONAL INPUT-OUTPUT EQUATION BASED ON A TYPE OF NONLINEAR LEONTIEF MODEL
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作者 胡问鸣 刘颖范 沙春林 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期224-229,共6页
A class of nonlinear and continuous type Leontief model and its corresponding conditional input-output equation are introduced, and two basic problems under the so called positive or negative boundary assumption are p... A class of nonlinear and continuous type Leontief model and its corresponding conditional input-output equation are introduced, and two basic problems under the so called positive or negative boundary assumption are presented. By approaches of nonlinear analysis some solvability results of this equation and continuous perturbation properties of the relative solution sets are obtained, and some economic significance are illustrated by the remark. 展开更多
关键词 conditional Leontief model input-output equation positive (negative) boundary assumption nonlinear analysis SOLVABILITY continuous disturbance
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