Precision of Earthwork Computation by Grid

2011 ◽  
Vol 243-249 ◽  
pp. 5864-5868
Author(s):  
Hong Hu Wei ◽  
Yan Bao
Keyword(s):  
Theoretical Calculation ◽  
Relative Error ◽  
Grid Method ◽  
Theoretical Models ◽  
Basic Relationship ◽  
Terrain Parameters

Based on theoretical models,the accuracy is analyzed to earthwork calculation in grid method under different terrain rolling rates, different grid widths.And the basic relationship between relative error of theoretical calculation and grid and terrain parameters is obtained, which can be used for evaluation of practical earthwork calculation.

scholarly journals A Wet Gas Metering System Based on the Extended-Throat Venturi Tube

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2120
Author(s):  
Haobai Xue ◽  
Peining Yu ◽  
Maomao Zhang ◽  
Haifeng Zhang ◽  
Encheng Wang ◽  
...  
Keyword(s):  
Relative Error ◽  
Theoretical Models ◽  
Venturi Tube ◽  
Iteration Algorithm ◽  
Liquid Content ◽  
Wet Gas ◽  
Error Distributions ◽  
Relative Errors ◽  
Throat Section ◽  
The Relationship

Although the use of a classical Venturi tube for wet gas metering has been extensively studied in the literature, the use of an extended-throat Venturi (ETV) tube has rarely been reported since its first proposal by J. R. Fincke in 1999. The structure of an ETV is very simple, but due to the complexity of multiphase flow, its theoretical model has not been fully established yet. Therefore, in this paper theoretical models have been developed for the convergent and throat sections of an ETV, and the gradients of front and rear differential pressures are derived analytically. Several flowrate algorithms have been proposed and compared with the existing ones. Among them, the iteration algorithm is found to be the best. A reasonable explanation is provided for its performance. The relationship between the differential pressure gradient and the flowrate relative error is also studied, such that the relative error distributions varying with ETV measured flowrates can be derived. The gas flowrate error of ETV increases with the liquid content whilst the liquid flowrate error of ETV decreases with the liquid content, and the relative errors of liquid flowrate are generally 2 to 3 times larger than that of the gas flowrate. Finally, the ETV tends to be more accurate than the classical Venturi tube. The ETV can be designed more compact under the same signal intensity due to its significantly higher velocity in the throat section.

Calculating Failure Pressure Under Different Failure Modes in the Roof-to-Shell of a Vaulted Tank

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Yuqi Ding ◽  
Jubao Liu ◽  
Zengtao Chen ◽  
Feng Qiu ◽  
Qifa Lu
Keyword(s):  
Finite Element ◽  
Theoretical Calculation ◽  
Relative Error ◽  
Failure Criterion ◽  
Failure Modes ◽  
Maximum Relative Error ◽  
Failure Pressure ◽  
Compression Ring ◽  
Strength Failure ◽  
Ring Section

In this study, two failure modes, yield buckling of the compression ring section and strength failure in the roof-to-shell of the tank, have been proposed for a vertical vaulted tank. The failure criteria of the two failure modes in the roof-to-shell of vault tanks are established via finite element analysis of three tanks of 640 m3, 3200 m3, and 6800 m3 in volume. The finite element models are built with axisymmetric elements and spatial multi-elements. Based on the strength failure criterion, the failure pressure formula in the vaulted tank roof-to-shell is derived. The maximum relative error between the theoretical calculation and numerical simulation is 9.7%. Finally, we verify the strength failure criterion through a tank failure test; the maximum relative error between the test and theoretical calculation is 9.6%. The failure pressure of both failure modes has been compared and analyzed. The failure pressure of the yield buckling in the compression ring section is about 1.65 times that of the strength failure in the roof-to-shell of the tank.

scholarly journals Theoretical calculation of transmission loss of noise panels

2018 ◽  
Vol 19 (12) ◽  
pp. 553-556
Author(s):  
Leszek Majkut ◽  
Ryszard Olszewski
Keyword(s):  
Theoretical Calculation ◽  
Thin Plate ◽  
Transmission Loss ◽  
Theoretical Models ◽  
Flexible Body ◽  
Plate Model ◽  
Loss Calculation ◽  
Flexible Models

In the paper basic theoretical models of transmission loss calculation are described. Here only single homogeneous isotropic panels are analysed. Three impedance values of one rigid and two flexible body models of panel are described and analysed. As flexible models the thin plate (Kirchhoff-Love plate model) i thick (Mindlin – Reissner model) are analysed.

Theoretical Simulation of Temperature Field of Coaxial Powder Stream in Laser Cladding

2008 ◽  
Vol 392-394 ◽  
pp. 245-249
Author(s):  
Z. Dong ◽  
Xi Chen Yang
Keyword(s):  
Temperature Field ◽  
Theoretical Calculation ◽  
Laser Cladding ◽  
Ccd Camera ◽  
Theoretical Models ◽  
Experimental Results ◽  
Powder Flow ◽  
Flow Temperature ◽  
Theoretical Simulation ◽  
Theoretical Results

Theoretical models of temperature field are presented from Beer-Lambert law. This paper uses Beer-Lambert law to calculate powder flow on the absorption of energy and applies the law of the conservation of the energy to calculate the temperature of powder stream. This paper analyzes the effect of the various factors on the temperature field of powder flow. Temperature field of powder stream is measured by CCD camera. Finally the comparison of the theoretical results and the experimental results indicates the accuracy of the theoretical calculation.

Research on Spiral Teeth Volume of Driven Rotor with Fixed Cross Rolling

2013 ◽  
Vol 431 ◽  
pp. 93-98
Author(s):  
Guang Yang ◽  
Kang Sheng Zhang
Keyword(s):  
Theoretical Calculation ◽  
Relative Error ◽  
Significant Influence ◽  
Satisfactory Result ◽  
General Equation ◽  
Sectional Area ◽  
Cross Rolling ◽  
Screw Rotor

Profile of the screw rotor comprised of varieties of curves is characterized by complexity and asymmetry. Determination of the billet diameter has a significant influence on the quality of the driven rotor formed by fixed cross rolling. Owing to this the general equation to determine the area of the complex tooth has been presented. Then detailed calculations of the spiral teeth volume and the sectional area of the driven rotor have been carried out. Satisfactory result that the relative error is less than 0.002% has been demonstrated by comparison of theoretical calculation and measurement result to verify the accuracy of the proposed theoretical calculation.

Analytical Electron Microscopy of Surface-Modified Ceramics

1985 ◽  
Vol 43 ◽  
pp. 276-279
Author(s):  
P. S. Sklad
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Theoretical Models ◽  
Ceramic Materials ◽  
Solute Concentration ◽  
Second Phase ◽  
Analytical Electron ◽  
Implantation Techniques ◽  
Lattice Damage ◽  
Surface Modified

Over the past several years, it has become increasingly evident that materials for proposed advanced energy systems will be required to operate at high temperatures and in aggressive environments. These constraints make structural ceramics attractive materials for these systems. However it is well known that the condition of the specimen surface of ceramic materials is often critical in controlling properties such as fracture toughness, oxidation resistance, and wear resistance. Ion implantation techniques offer the potential of overcoming some of the surface related limitations.While the effects of implantation on surface sensitive properties may be measured indpendently, it is important to understand the microstructural evolution leading to these changes. Analytical electron microscopy provides a useful tool for characterizing the microstructures produced in terms of solute concentration profiles, second phase formation, lattice damage, crystallinity of the implanted layer, and annealing behavior. Such analyses allow correlations to be made with theoretical models, property measurements, and results of complimentary techniques.

On the Relationship Between General Auditory Sensitivity and Speech Perception: An Examination of Pitch and Lexical Tone Perception in 4- to 6-Year-Old Children

2020 ◽  
Vol 63 (2) ◽  
pp. 487-498
Author(s):  
Puisan Wong ◽  
Man Wai Cheng
Keyword(s):  
Speech Perception ◽  
Theoretical Models ◽  
Developmental Trajectory ◽  
Auditory Sensitivity ◽  
Pitch Discrimination ◽  
Lexical Tone ◽  
Perceptual Training ◽  
Lexical Tones ◽  
Tone Perception ◽  
Tone Discrimination

Purpose Theoretical models and substantial research have proposed that general auditory sensitivity is a developmental foundation for speech perception and language acquisition. Nonetheless, controversies exist about the effectiveness of general auditory training in improving speech and language skills. This research investigated the relationships among general auditory sensitivity, phonemic speech perception, and word-level speech perception via the examination of pitch and lexical tone perception in children. Method Forty-eight typically developing 4- to 6-year-old Cantonese-speaking children were tested on the discrimination of the pitch patterns of lexical tones in synthetic stimuli, discrimination of naturally produced lexical tones, and identification of lexical tone in familiar words. Results The findings revealed that accurate lexical tone discrimination and identification did not necessarily entail the accurate discrimination of nonlinguistic stimuli that followed the pitch levels and pitch shapes of lexical tones. Although pitch discrimination and tone discrimination abilities were strongly correlated, accuracy in pitch discrimination was lower than that in tone discrimination, and nonspeech pitch discrimination ability did not precede linguistic tone discrimination in the developmental trajectory. Conclusions Contradicting the theoretical models, the findings of this study suggest that general auditory sensitivity and speech perception may not be causally or hierarchically related. The finding that accuracy in pitch discrimination is lower than that in tone discrimination suggests that comparable nonlinguistic auditory perceptual ability may not be necessary for accurate speech perception and language learning. The results cast doubt on the use of nonlinguistic auditory perceptual training to improve children's speech, language, and literacy abilities.

Positive Arousal Enhances the Consolidation of Item Memory

2015 ◽  
Vol 74 (2) ◽  
pp. 91-104 ◽  
Author(s):  
Bo Wang
Keyword(s):  
Episodic Memory ◽  
Memory Consolidation ◽  
Source Memory ◽  
Emotional Arousal ◽  
Theoretical Models ◽  
Memory Test ◽  
Learning Phase ◽  
Item Memory ◽  
Memory Tests ◽  
Immediate Memory

Emotional arousal induced after learning has been shown to modulate memory consolidation. However, it is unclear whether the effect of postlearning arousal can extend to different aspects of memory. This study examined the effect of postlearning positive arousal on both item memory and source memory. Participants learned a list of neutral words and took an immediate memory test. Then they watched a positive or a neutral videoclip and took delayed memory tests after either 25 minutes or 1 week had elapsed after the learning phase. In both delay conditions, positive arousal enhanced consolidation of item memory as measured by overall recognition. Furthermore, positive arousal enhanced consolidation of familiarity but not recollection. However, positive arousal appeared to have no effect on consolidation of source memory. These findings have implications for building theoretical models of the effect of emotional arousal on consolidation of episodic memory and for applying postlearning emotional arousal as a technique of memory intervention.

The Role of Distress Disclosure Tendencies in the Experience and Expression of Laboratory-Induced Sadness

2017 ◽  
Vol 38 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Jeffrey H. Kahn ◽  
Daniel W. Cox ◽  
A. Myfanwy Bakker ◽  
Julia I. O’Loughlin ◽  
Agnieszka M. Kotlarczyk
Keyword(s):  
Individual Differences ◽  
Emotional Reactivity ◽  
Subjective Experience ◽  
Negative Emotion ◽  
Theoretical Models ◽  
Laboratory Research ◽  
Emotion Words ◽  
Distress Disclosure ◽  
Computerized Text Analysis

Abstract. The benefits of talking with others about unpleasant emotions have been thoroughly investigated, but individual differences in distress disclosure tendencies have not been adequately integrated within theoretical models of emotion. The purpose of this laboratory research was to determine whether distress disclosure tendencies stem from differences in emotional reactivity or differences in emotion regulation. After completing measures of distress disclosure tendencies, social desirability, and positive and negative affect, 84 participants (74% women) were video recorded while viewing a sadness-inducing film clip. Participants completed post-film measures of affect and were then interviewed about their reactions to the film; these interviews were audio recorded for later coding and computerized text analysis. Distress disclosure tendencies were not predictive of the subjective experience of emotion, but they were positively related to facial expressions of sadness and happiness. Distress disclosure tendencies also predicted judges’ ratings of the verbal disclosure of emotion during the interview, but self-reported disclosure and use of positive and negative emotion words were not associated with distress disclosure tendencies. The authors present implications of this research for integrating individual differences in distress disclosure with models of emotion.

Convergent and Predictive Validity of Implicit and Explicit Anxiety Measures as a Function of Specificity Similarity and Content Similarity

2008 ◽  
Vol 24 (4) ◽  
pp. 254-262 ◽  
Author(s):  
Tobias Gschwendner ◽  
Wilhelm Hofmann ◽  
Manfred Schmitt
Keyword(s):  
Implicit Association Test ◽  
Theoretical Models ◽  
Implicit Measures ◽  
Speech Anxiety ◽  
Behavioral Indicators ◽  
General Anxiety ◽  
Anxious Behavior ◽  
Content Similarity ◽  
Implicit And Explicit ◽  
Validation Strategy

In the present study we applied a validation strategy for implicit measures like the IAT, which complements multitrait-multimethod (MTMM) analyses. As the measurement method (implicit vs. explicit) and underlying representation format (associative vs. propositional) are often confounded, the validation of implicit measures has to go beyond MTMM analysis and requires substantive theoretical models. In the present study (N = 133), we employed such a model ( Hofmann, Gschwendner, Nosek, & Schmitt, 2005 ) and investigated two moderator constructs in the realm of anxiety: specificity similarity and content similarity. In the first session, different general and specific anxiety measures were administered, among them an Implicit Association Test (IAT) general anxiety, an IAT-spider anxiety, and an IAT that assesses speech anxiety. In the second session, participants had to deliver a speech and behavioral indicators of speech anxiety were measured. Results showed that (a) implicit and explicit anxiety measures correlated significantly only on the same specification level and if they measured the same content, and (b) specific anxiety measures best predicted concrete anxious behavior. These results are discussed regarding the validation of implicit measures.

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