scholarly journals Comparing Sky Shape Skeletons for the Analysis of Visual Dynamics along Routes

2007 ◽  
Vol 34 (5) ◽  
pp. 840-857 ◽  
Author(s):  
François Sarradin ◽  
Daniel Siret ◽  
Michel Couprie ◽  
Jacques Teller
Keyword(s):  
Visual Field ◽  
Real Field ◽  
Open Spaces ◽  
New Approach ◽  
Contour Lines ◽  
Shape Skeletons

The motion of an observer in a given space produces a particular perception called motion perspective. This has been defined by Gibson as the gradual changes in the rate of displacements of contour lines in the visual field of the observer. This paper describes a new approach intended for analysing the motion perspective in order to quantify the morphology of urban open spaces along routes. It is based on spherical projections, which provide the shape of the sky boundary around the observer. The projections are studied through their skeletons, which are continuous sets of curves obtained by a progressive thinning down of the shapes around their main saliencies. The proposed method uses these skeletons to follow the variations in the shape of the sky boundary between the successive views. Measures of these variations have been developed and applied in a range of simplified theoretical examples and a real field example in order to show that they succeeded in capturing significant variations in spherical projections.

Alternative Environmental Contours for Marine Structural Design: A Comparison Study

2014 ◽  
Author(s):  
Erik Vanem ◽  
Elzbieta M. Bitner-Gregersen
Keyword(s):  
Structural Design ◽  
Joint Distribution ◽  
Traditional Approach ◽  
Physical Space ◽  
Probability Density Functions ◽  
Density Functions ◽  
Comparison Study ◽  
New Approach ◽  
Contour Lines ◽  
Wind Sea

A new approach to estimating environmental contours has recently been proposed, where the contours are estimated in the original physical space by Monte Carlo simulations from the joint distribution directly rather than applying the Rosenblatt transformation. In this paper, the new and the traditional approach to estimating the contours are presented and the assumptions on which they are based are discussed. The different results given by these two methods are then compared in a number of case studies. Simultaneous probability density functions are fitted to the joint distribution of significant wave height and wave period for selected ocean locations and, for each area, environmental contours are estimated for both methods. The chosen locations are characterised by different wave climates. Thus, the practical consequences of the choice of approach are assessed. Particular attention is given to mixed sea systems, i.e. a combination of wind sea and swell. In these situations, the new approach for environmental contours may fail to identify realistic conditions along some parts of the contours while for other wave conditions the contours are quite similar. The paper also briefly discusses possible ways of amending the new approach to estimating the contours to obtain more realistic conditions all along the contour lines.

scholarly journals A New Approach for Determining the Control Volumes of Production Wells considering Irregular Well Distribution and Heterogeneous Reservoir Properties

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Cheng Lu ◽  
Ling Chen ◽  
Xiaodong Wang ◽  
Wanjing Luo ◽  
Yue Peng ◽  
...  
Keyword(s):  
Control Volume ◽  
Computational Cost ◽  
Real Field ◽  
Well Performance ◽  
Production Well ◽  
Reservoir Model ◽  
Reservoir Properties ◽  
New Approach ◽  
Production Wells ◽  
Control Volumes

The oil and gas fields are commonly developed with a group of production wells. Therefore, it can be essential for the industries to predict the performance of the production wells in order to optimize the development strategies. In practice, it frequently happens that we only hope to study the performance of a single production well. In such cases, it can be time consuming to run the reservoir simulation with the entire reservoir model to study the well performance. Hence, it can be preferred to determine the control volume (or drainage volume) of the target well from the entire reservoir and run the simulation with the small control volume to reduce the simulation cost. However, an irregular layout of the production wells and the heterogeneity of reservoir properties, which can be commonly observed in real field cases, can induce a stringent barrier for one to determine the control volumes. At present, we are still lacking a method to determine the control volumes of the production wells considering well distribution and reservoir heterogeneities. In order to overcome such a barrier, the authors proposed a new approach to divide the entire reservoir into small control volumes on the basis of the fast marching method (FMM). This approach is validated by comparing the simulation outputs of the target well calculated only with the determined control volume to those calculated with the entire reservoir model. The calculated results show that using the control volume that is determined with the proposed method to calculate the well performance can yield results that agree well with the results that are calculated with the entire reservoir model. This indicates that this proposed method is reliable to determine the control volume of the production wells. In addition, the calculated results in this work show that changing fracture length exerts a slight influence on the control volumes if the length of all fractures is increased, whereas, if only one of the fracture lengths is increased, the control volume of the corresponding well will be significantly increased. The number of the production wells and the distribution of the production well can noticeably influence the control volumes of the production wells. The findings of this study can help for optimizing the well spacing, estimating the ultimate recovery, and reducing the computational cost.

scholarly journals Elastic plastic analysis of shallow shells—a new approach

2005 ◽  
Vol 47 (1) ◽  
pp. 121-130
Author(s):  
J. Mazumdar ◽  
A. Ghosh ◽  
J. S. Hewitt ◽  
P. K. Bhattacharya
Keyword(s):  
Plastic Deformation ◽  
Efficient Method ◽  
Plastic Bending ◽  
New Approach ◽  
Shallow Shells ◽  
Elastic Plastic ◽  
Aspect Ratios ◽  
Contour Lines ◽  
Plastic Analysis

AbstractA simple and efficient method for the analysis of the elastic-plastic bending of shallow shells is presented. The method is based upon the concept of contour lines of equal deflection on the surface of the shell, and uses Illyushin's theory of plastic deformation. As an illustration of the method, a technically interesting example of a shallow elliptic elastic dome is examined. Results are obtained for increasing loads and varying aspect ratios, and are illustrated graphically. The application of the method to other shell geometries is quite straightforward.

scholarly journals Sonhos e esperanças de cortesia espiritual: Um desafio para a Igreja Católica no século XXI

2019 ◽  
Vol 65 (260) ◽  
pp. 817
Author(s):  
Faustino Teixeira
Keyword(s):  
Catholic Church ◽  
Religious Pluralism ◽  
Open Spaces ◽  
New Approach ◽  
Institutional Dynamics ◽  
Religious Traditions ◽  
The Church ◽  
The Catholic Church

Um dos sinais mais significativos de nosso tempo é o pluralismo religioso. A Igreja Católica é hoje convocada a perscrutar este sinal e disponibilizar-se a captar o seu significado mais profundo no desígnio salvífico de Deus. A trajetória recente da Igreja esteve pontuada por ambigüidades a respeito da abertura às religiões. Há o peso de uma dinâmica institucional mais reticente ao tema, mas há também gestos geradores de futuro, que abrem espaços para uma trajetória alternativa. Impõe-se hoje uma nova aproximação às diversas tradições religiosas, que possa estar animada pela cortesia espiritual e pela hospitalidade. Não há possibilidade de um crescimento eclesial cerrado ao desafio imprescindível da abertura ao outro.Abstract: One of the most significant signs of our time is religious pluralism. Nowadays the Catholic Church is summoned to probe into this sign, and capture its deeper meaning in the saving design of God. The recent trajectory of the Church has been full of ambiguities regarding the opening to other religions. There has been the weight of a more reticent institutional dynamics to the theme, but there have also been future generating gestures, that open spaces for an alternative trajectory. Today it is fundamental to have a new approach to the several religious traditions, encouraged by spiritual courtesy and hospitality. There cannot be an ecclesiastic growth without the indispensable challenge of being open to others.

scholarly journals New approach to estimating variability in visual field data using an image processing technique.

1995 ◽  
Vol 79 (3) ◽  
pp. 213-217 ◽  
Author(s):  
D P Crabb ◽  
D F Edgar ◽  
F W Fitzke ◽  
A I McNaught ◽  
H P Wynn
Keyword(s):  
Image Processing ◽  
Visual Field ◽  
Field Data ◽  
Processing Technique ◽  
Image Processing Technique ◽  
New Approach

scholarly journals PENDEKATAN BARU PEMETAAN BATHIMETRIC MENGGUNAKAN DATA PENGINDERAAN JAUH SPOT STUDI KASUS: TELUK PERIGI DAN TELUK POPOH (THE NEW APPROACH TO MAPPING BATHIMETRIC USING SPOT REMOTE SENSING DATA CASE STUDY: THE BAY AND POPOH GULF)

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Muchlisin Arief
Keyword(s):  
Remote Sensing ◽  
Water Depth ◽  
Remote Sensing Data ◽  
Depth Map ◽  
Quadratic Equation ◽  
Empirical Formulas ◽  
New Approach ◽  
Contour Lines ◽  
Shallow Water Depth

Bathymetric mapping derived from remote sensing have been carried out researchers, in order to determine the depth of the shallow waters especially sallow water depth. Bathymetric relief map shows the earth/terrain depicted by contour lines is called the isobath. Usually bathymetric determination using exponential function of depth. While in this paper described a new approach to calculate the depth of seawater derived from SPOT-4 satellite data using empirical formulas functions of logarithmic or quadratic equation built through correlasi the depth map obtained from DIHIDROS (Navy) with Digital Number or the reflectance values of SPOT band-1. This experience has been tested at Perigi bay in Trenggalek district and Popoh bay in Tulung Agung district. Based on the calculations, the spread of sallow water depth on Perigi and popoh bay about 5 – 70 meters Key words: Bathymetric, SPOT, Isobaths, Shallow water depth. correlation

scholarly journals UBathy: A New Approach for Bathymetric Inversion from Video Imagery

2019 ◽  
Vol 11 (23) ◽  
pp. 2722 ◽  
Author(s):  
Gonzalo Simarro ◽  
Daniel Calvete ◽  
Pau Luque ◽  
Alejandro Orfila ◽  
Francesca Ribas
Keyword(s):  
Wave Propagation ◽  
Principal Component ◽  
Wave Theory ◽  
Wave Dispersion ◽  
Complex Case ◽  
Real Field ◽  
Type Model ◽  
Linear Wave ◽  
Nonlinear Wave Propagation ◽  
New Approach

A new approach to infer the bathymetry from coastal video monitoring systems is presented. The methodology uses principal component analysis of the Hilbert transform of video images to obtain the components of the wave propagation field and their corresponding frequency and wavenumber. Incident and reflected constituents and subharmonics components are also found. Local water depth is then successfully estimated through wave dispersion relationship. The method is first applied to monochromatic and polychromatic synthetic wave trains propagated using linear wave theory over an alongshore uniform bathymetry in order to analyze the influence of different parameters on the results. To assess the ability of the approach to infer the bathymetry under more realistic conditions and to explore the influence of other parameters, nonlinear wave propagation is also performed using a fully nonlinear Boussinesq-type model over a complex bathymetry. In the synthetic cases, the relative root mean square error obtained in bathymetry recovery (for water depths 0.75 m ⩽ h ⩽ 8.0 m ) ranges from ∼1% to ∼3% for infinitesimal-amplitude wave cases (monochromatic or polychromatic) to ∼15% in the most complex case (nonlinear polychromatic waves). Finally, the new methodology is satisfactorily validated through a real field site video.

Dynamic Steam-Trap-Control Simulation Technique: Formulation, Implementation, and Performance Analysis

SPE Journal ◽  
2018 ◽  
Vol 23 (06) ◽  
pp. 2015-2025 ◽  
Author(s):  
M.. Heidari ◽  
Long X. Nghiem
Keyword(s):  
Mathematical Formulation ◽  
Saturation Temperature ◽  
Control Technique ◽  
Thermodynamic Approach ◽  
Real Field ◽  
Total Production ◽  
Production Well ◽  
New Approach ◽  
Steam Trap ◽  
Run Time

Summary Steam-trap subcool is a technique that is used to maintain the energy efficiency of the steam-assisted-gravity-drainage (SAGD) process by most heavy-oil producers in Canada. The concept is rather simple (i.e., create a liquid pool around the production well to prevent steam from escaping from the steam chamber into the production well). A numerical steam trap based on a thermodynamic approach was implemented by Edmunds (2000), and it has been used in simulations with different types of wellbore models in commercial codes. In this approach, a thermodynamic relationship is solved as a well-residual equation to guarantee that the bottomhole temperature (BHT) is less than the saturation temperature of water at the hottest location along the wellbore. The location of the hottest spot along the wellbore is static in time. Steam trap is a dynamic process, and inflow temperatures can vary significantly along the wellbore according to the local fluid and rock properties along the well. It is highly possible that the location of the hottest spot along the well changes frequently with time during the SAGD operation. In this study, the simulation of a dynamic steam-trap-control technique is provided. The location of the hottest spot along the wellbore is scanned at every timestep. Severe numerical instabilities are observed when the thermodynamic approach is used. A new constraint based on the total production rate at reservoir condition is introduced. Details of the mathematical formulation and the numerical behavior of the new method are discussed in this paper. Several real field models with different wellbore designs (multiple tubing strings) are simulated, and the results of the new approach are compared with the thermodynamic approach. Simulation results show that the numerical performance of this new approach is significantly more stable. We also compared the run time of simulation between cases with new well constraint and thermodynamic steam-trap control, and results show a significant improvement in simulation run time.

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