A new model for predicting three-dimensional beach changes by expanding Hsu and Evans' equation

A cross-sectionally averaged one-dimensional long-wave model is developed. Three-dimensional equations of motion for inviscid and incompressible fluid are first integrated over a channel cross-section. To express the resulting one-dimensional equations in terms of the cross-sectional-averaged longitudinal velocity and spanwise-averaged free-surface elevation, the characteristic depth and width of the channel cross-section are assumed to be smaller than the typical wavelength, resulting in Boussinesq-type equations. Viscous effects are also considered. The new model is, therefore, adequate for describing weakly nonlinear and weakly dispersive wave propagation along a non-uniform channel with arbitrary cross-section. More specifically, the new model has the following new properties: (i) the arbitrary channel cross-section can be asymmetric with respect to the direction of wave propagation, (ii) the channel cross-section can change appreciably within a wavelength, (iii) the effects of viscosity inside the bottom boundary layer can be considered, and (iv) the three-dimensional flow features can be recovered from the perturbation solutions. Analytical and numerical examples for uniform channels, channels where the cross-sectional geometry changes slowly and channels where the depth and width variation is appreciable within the wavelength scale are discussed to illustrate the validity and capability of the present model. With the consideration of viscous boundary layer effects, the present theory agrees reasonably well with experimental results presented by Chang et al. (J. Fluid Mech., vol. 95, 1979, pp. 401–414) for converging/diverging channels and those of Liu et al. (Coast. Engng, vol. 53, 2006, pp. 181–190) for a uniform channel with a sloping beach. The numerical results for a solitary wave propagating in a channel where the width variation is appreciable within a wavelength are discussed.

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The Efficiency of Tidal Fences: A Brief Review and Further Discussion on the Effect of Wake Mixing

Volume 8: Ocean Renewable Energy ◽

10.1115/omae2013-10207 ◽

2013 ◽

Cited By ~ 2

Author(s):

Takafumi Nishino ◽

Richard H. J. Willden

Keyword(s):

Energy Balance ◽

Theoretical Investigation ◽

Three Dimensional ◽

Physical Factors ◽

Balance Equations ◽

Order Model ◽

Near Wake ◽

New Model ◽

Actuator Disk ◽

Limiting Efficiency

Recent discoveries on the limiting efficiency of tidal fences are reviewed, followed by a new theoretical investigation into the effect of wake mixing on the efficiency of ‘full’ tidal fences (i.e. turbines arrayed regularly across an entire channel span). The new model is based on the momentum and energy balance equations but includes several unclosed terms, which depend on the actual (three-dimensional) characteristics of turbine near-wake mixing and therefore need to be modelled empirically. The new model agrees well with three-dimensional actuator disk simulations when those unclosed terms are assessed based on the simulations themselves, suggesting that this low-order model could serve as a basis to analyse how various physical factors (such as the design of turbines) affect the limiting efficiency of tidal fences via changes in those terms describing the characteristics of turbine near-wake mixing. Also discussed is the effect of wake mixing on the efficiency of ‘partial’ tidal fences.

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A new model-based framework for lung tissue segmentation in three-dimensional thoracic CT images

Signal Image and Video Processing ◽

10.1007/s11760-017-1163-y ◽

2017 ◽

Vol 12 (2) ◽

pp. 339-346 ◽

Cited By ~ 1

Author(s):

Zeinab Naseri Samaghcheh ◽

Fatemeh Abdoli ◽

Hamid Abrishami Moghaddam ◽

Mohammadreza Modaresi ◽

Neda Pak

Keyword(s):

Lung Tissue ◽

Three Dimensional ◽

Ct Images ◽

Tissue Segmentation ◽

New Model ◽

Model Based ◽

Thoracic Ct

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A new model of conflict analysis — the three dimensional graph model

European Journal of Operational Research ◽

10.1016/0377-2217(94)00345-9 ◽

1996 ◽

Vol 90 (3) ◽

pp. 619-624 ◽

Cited By ~ 1

Author(s):

Yuhua Wu ◽

Dewen Cheng ◽

M. Wolfe

Keyword(s):

Three Dimensional ◽

Graph Model ◽

Conflict Analysis ◽

New Model ◽

Dimensional Graph

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A simulation study with a new residual ionospheric error model for GPS radio occultation climatologies

Atmospheric Measurement Techniques ◽

10.5194/amt-8-3395-2015 ◽

2015 ◽

Vol 8 (8) ◽

pp. 3395-3404 ◽

Cited By ~ 15

Author(s):

J. Danzer ◽

S. B. Healy ◽

I. D. Culverwell

Keyword(s):

Simulation Study ◽

Radio Occultation ◽

Three Dimensional ◽

Error Model ◽

Residual Error ◽

New Model ◽

Gps Radio Occultation ◽

Two Factors ◽

Set Up ◽

L1 And L2

Abstract. In this study, a new model was explored which corrects for higher order ionospheric residuals in Global Positioning System (GPS) radio occultation (RO) data. Recently, the theoretical basis of this new "residual ionospheric error model" has been outlined (Healy and Culverwell, 2015). The method was tested in simulations with a one-dimensional model ionosphere. The proposed new model for computing the residual ionospheric error is the product of two factors, one of which expresses its variation from profile to profile and from time to time in terms of measurable quantities (the L1 and L2 bending angles), while the other describes the weak variation with altitude. A simple integral expression for the residual error (Vorob’ev and Krasil’nikova, 1994) has been shown to be in excellent numerical agreement with the exact value, for a simple Chapman layer ionosphere. In this case, the "altitudinal" element of the residual error varies (decreases) by no more than about 25 % between ~10 and ~100 km for physically reasonable Chapman layer parameters. For other simple model ionospheres the integral can be evaluated exactly, and results are in reasonable agreement with those of an equivalent Chapman layer. In this follow-up study the overall objective was to explore the validity of the new residual ionospheric error model for more detailed simulations, based on modeling through a complex three-dimensional ionosphere. The simulation study was set up, simulating day and night GPS RO profiles for the period of a solar cycle with and without an ionosphere. The residual ionospheric error was studied, the new error model was tested, and temporal and spatial variations of the model were investigated. The model performed well in the simulation study, capturing the temporal variability of the ionospheric residual. Although it was not possible, due to high noise of the simulated bending-angle profiles at mid- to high latitudes, to perform a thorough latitudinal investigation of the performance of the model, first positive and encouraging results were found at low latitudes. Furthermore, first application tests of the model on the data showed a reduction in temperature level of the ionospheric residual at 40 km from about −2.2 to −0.2 K.

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A simulation study with a new residual ionospheric error model for GPS radio occultation climatologies

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-8-1151-2015 ◽

2015 ◽

Vol 8 (1) ◽

pp. 1151-1176 ◽

Cited By ~ 1

Author(s):

J. Danzer ◽

S. B. Healy ◽

I. D. Culverwell

Keyword(s):

Simulation Study ◽

Radio Occultation ◽

Three Dimensional ◽

Error Model ◽

Residual Error ◽

New Model ◽

Gps Radio Occultation ◽

Two Factors ◽

Set Up ◽

L1 And L2

Abstract. In this study, a new model was explored, which corrects for higher order ionospheric residuals in global positioning system (GPS) radio occultation (RO) data. Recently, the theoretical basis of this new "residual ionospheric error model" has been outlined (Healy and Culverwell, 2015). The method was tested in simulations with a one-dimensional model ionosphere. The proposed new model for computing the residual ionospheric error is the product of two factors, one of which expresses its variation from profile-to-profile and from time-to-time in terms of measurable quantities (the L1 and L2 bending angles), the other of which describes the weak variation with altitude. A simple integral expression for the residual error (Vorob’ev and Krasil’nikova, 1994) has been shown to be in excellent numerical agreement with the exact value, for a simple Chapman layer ionosphere. In this case, the "altitudinal" element of the residual error varies (decreases) by no more than about 25% between ~10 and ~100 km for physically reasonable Chapman layer parameters. For other simple model ionospheres the integral can be evaluated exactly, and results are in reasonable agreement with those of an equivalent Chapman layer. In this follow-up study the overall objective was to explore the validity of the new residual ionospheric error model for more detailed simulations, based on modelling through a complex three-dimensional ionosphere. The simulation study was set up, simulating day and night GPS RO profiles for the period of a solar cycle with and without an ionosphere. The residual ionospheric error was studied, the new error model was tested, and temporal and spatial variations of the model were investigated. The model performed well in the simulation study, capturing the temporal variability of the ionospheric residual. Although, it was not possible, due to high noise of the simulated bending angle profiles at mid to high latitudes, to perform a thorough latitudinal investigation of the performance of the model, first positive and encouraging results were found at low latitudes. Furthermore, first application tests of the model on the data showed a reduction on temperature level of the ionospheric residual at 40 km from about −2.2 to −0.2 K.

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Evaluation of the Validity, Reliability, and Kinematic Characteristics of Multi-Segment Foot Models in Motion Capture

Sensors ◽

10.3390/s20164415 ◽

2020 ◽

Vol 20 (16) ◽

pp. 4415

Author(s):

Yuka Sekiguchi ◽

Takanori Kokubun ◽

Hiroki Hanawa ◽

Hitomi Shono ◽

Ayumi Tsuruta ◽

...

Keyword(s):

Motion Capture ◽

Three Dimensional ◽

Validity And Reliability ◽

New Model ◽

Living Body ◽

Kinematic Characteristics ◽

Foot Motion ◽

Drop Jumps ◽

Foot Model ◽

True Values

This study aimed to evaluate the validity and reliability of our new multi-segment foot model by measuring a dummy foot, and examine the kinematic characteristics of our new multi-segment foot model by measuring the living body. Using our new model and the Rizzoli model, we conducted two experiments with a dummy foot that was moved within a range from −90 to 90 degrees in all planes; for the living body, 24 participants performed calf raises, gait, and drop jumps. Most three-dimensional (3D) rotation angles calculated according to our new models were strongly positively correlated with true values (r > 0.8, p < 0.01). Most 3D rotation angles had fixed biases; however, most of them were in the range of the limits of agreement. Temporal patterns of foot motion, such as those in the Rizzoli model, were observed in our new model during all dynamic tasks. We concluded that our new multi-segment foot model was valid for motion analysis and was useful for analyzing the foot motion using 3D motion capture during dynamic tasks.

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New Model Material for Three-Dimensional Stress Analysis

Journal of Testing and Evaluation ◽

10.1520/jte10177j ◽

1975 ◽

Vol 3 (5) ◽

pp. 368 ◽

Cited By ~ 2

Author(s):

SF Etris ◽

YR Fiorini ◽

KC Lieb ◽

IC Moore ◽

AL Batik ◽

...

Keyword(s):

Stress Analysis ◽

Three Dimensional ◽

Model Material ◽

New Model

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A New Model for Nuclear Envelope Breakdown

Molecular Biology of the Cell ◽

10.1091/mbc.12.2.503 ◽

2001 ◽

Vol 12 (2) ◽

pp. 503-510 ◽

Cited By ~ 73

Author(s):

Mark Terasaki ◽

Paul Campagnola ◽

Melissa M. Rolls ◽

Pascal A. Stein ◽

Jan Ellenberg ◽

...

Keyword(s):

Nuclear Envelope ◽

Fluorescent Protein ◽

Three Dimensional ◽

Nuclear Pore ◽

Permeability Barrier ◽

Second Phase ◽

New Model ◽

Nuclear Envelope Breakdown ◽

Two Phases ◽

Green Fluorescent

Nuclear envelope breakdown was investigated during meiotic maturation of starfish oocytes. Fluorescent 70-kDa dextran entry, as monitored by confocal microscopy, consists of two phases, a slow uniform increase and then a massive wave. From quantitative analysis of the first phase of dextran entry, and from imaging of green fluorescent protein chimeras, we conclude that nuclear pore disassembly begins several minutes before nuclear envelope breakdown. The best fit for the second phase of entry is with a spreading disruption of the membrane permeability barrier determined by three-dimensional computer simulations of diffusion. We propose a new model for the mechanism of nuclear envelope breakdown in which disassembly of the nuclear pores leads to a fenestration of the nuclear envelope double membrane.

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