Stacking apertures and estimation strategies for reflection and diffraction enhancement

Geophysics ◽  
2016 ◽  
Vol 81 (4) ◽  
pp. V271-V282 ◽  
Author(s):  
Jorge H. Faccipieri ◽  
Tiago A. Coimbra ◽  
Leiv-J. Gelius ◽  
Martin Tygel
Keyword(s):  
Fresnel Zone ◽  
Careful Selection ◽  
Time Migration ◽  
Key Factor ◽  
Common Reflection Surface ◽  
Good Potential ◽  
Image Quality Improvement ◽  
The Common ◽  
Selection Of

It is well known that the quality of stacking results (e.g., noise reduction, event enhancement, and continuity) can be greatly influenced not only by the traveltime operator chosen but also by the apertures used. We have considered two so-called diffraction-stack traveltimes, together with the corresponding apertures, designed to enhance reflections and diffractions, respectively. The first one is the common-reflection-surface (CRS) diffraction traveltime that is obtained from the general CRS traveltime upon the condition that the target reflector reduced to a point, which we refer to as the diffraction CRS (DCRS) traveltime. The second one is the double-square-root (DSR) traveltime, well established in time migration. We have observed that the DCRS and DSR traveltimes depend on fewer parameters (two in 2D and five in 3D) than the full CRS traveltime (three in 2D and eight in 3D). For the DCRS and DSR traveltimes, we have proposed specific apertures based on the projected Fresnel zone, which are able to produce high-quality stacked sections using less parameters to be estimated. The key factor in that approach lies in the choice of traveltime operators together with careful selection of stacking apertures. In particular, suitable choices of operators and apertures lead to stacking volumes in which reflections are enhanced (and the diffractions are attenuated) or the corresponding ones in which diffractions are enhanced (and reflections are attenuated). Synthetic and field data confirm the proposed approach has good potential for image-quality improvement.

Velocity-estimation improvements and migration/demigration using the common-reflection surface with continuing deconvolution in the time domain

Geophysics ◽  
2019 ◽  
Vol 84 (4) ◽  
pp. S229-S238 ◽  
Author(s):  
Martina Glöckner ◽  
Sergius Dell ◽  
Benjamin Schwarz ◽  
Claudia Vanelle ◽  
Dirk Gajewski
Keyword(s):  
Model Building ◽  
Velocity Model ◽  
Velocity Estimation ◽  
Initial Time ◽  
Model Errors ◽  
Imaging Methods ◽  
Time Migration ◽  
Common Reflection Surface ◽  
The Common ◽  
And Migration

To obtain an image of the earth’s subsurface, time-imaging methods can be applied because they are reasonably fast, are less sensitive to velocity model errors than depth-imaging methods, and are usually easy to parallelize. A powerful tool for time imaging consists of a series of prestack time migrations and demigrations. We have applied multiparameter stacking techniques to obtain an initial time-migration velocity model. The velocity model building proposed here is based on the kinematic wavefield attributes of the common-reflection surface (CRS) method. A subsequent refinement of the velocities uses a coherence filter that is based on a predetermined threshold, followed by an interpolation and smoothing. Then, we perform a migration deconvolution to obtain the final time-migrated image. The migration deconvolution consists of one iteration of least-squares migration with an estimated Hessian. We estimate the Hessian by nonstationary matching filters, i.e., in a data-driven fashion. The model building uses the framework of the CRS, and the migration deconvolution is fully automated. Therefore, minimal user interaction is required to carry out the velocity model refinement and the image update. We apply the velocity refinement and migration deconvolution approaches to complex synthetic and field data.

scholarly journals A CONCEPTUAL REVIEW ON TREATMENT MODALITIES FOR RAKTAPRADAR W.S.R. TO DUB

2021 ◽  
Vol 9 (12) ◽  
pp. 3038-3048
Author(s):  
Himani Gupta ◽  
Poonam Bamola ◽  
Nikita Jaiswal
Keyword(s):  
Quality Of Life ◽  
Sustainable Development ◽  
Iron Deficiency ◽  
Treatment Modalities ◽  
Deficiency Anemia ◽  
Common Cause ◽  
The Family ◽  
Key Factor ◽  
The Common

Women are the pioneers and key to sustainable development and quality of life in the family. Hindu culture respects women as Goddess due to this power of creativity of life inside her womb. This energy of procreation starts with menarche and ends with menopause. Ayurveda focusses on preventive and curative measures of female health. Acharya Charak mentioned “Yonishu Shuddhasu Garbham Vindati Yoshitaha” i.e., normal healthy status of Yoni (vagina) is the key factor for achieving the conception. Various gynaecological disorders like Yoni Rogas, Artava Doshas and Raktapradar hampers the achievement of conception. Raktapradar i.e., excessive excretion of men- strual blood, either in quantity or in duration is explained in Ayurvedic Classics. It is the common cause of Iron deficiency anemia & general debility. Ayurvedic intervention mentioned can be recommended as safer, feasible and effective therapy for management of Raktapradar. Keywords: Shudha Yoni, Yoni Roga, Artava Dosha, Raktapradar.

scholarly journals Does ENaC Work as Sodium Taste Receptor in Humans?

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1195 ◽  
Author(s):  
Albertino Bigiani
Keyword(s):  
Taste Receptor ◽  
Taste System ◽  
Physiological Processes ◽  
Salty Taste ◽  
Key Factor ◽  
Taste Reception ◽  
The Common ◽  
Preference Responses ◽  
Selection Of ◽  
Epithelial Sodium Channel Enac

Taste reception is fundamental for the proper selection of food and beverages. Among the several chemicals recognized by the human taste system, sodium ions (Na+) are of particular relevance. Na+ represents the main extracellular cation and is a key factor in many physiological processes. Na+ elicits a specific sensation, called salty taste, and low-medium concentrations of table salt (NaCl, the common sodium-containing chemical we use to season foods) are perceived as pleasant and appetitive. How we detect this cation in foodstuffs is scarcely understood. In animal models, such as the mouse and the rat, the epithelial sodium channel (ENaC) has been proposed as a key protein for recognizing Na+ and for mediating preference responses to low-medium salt concentrations. Here, I will review our current understanding regarding the possible involvement of ENaC in the detection of food Na+ by the human taste system.

scholarly journals Development of a Competency Model for Selection of Human Resources in the Mining and Quarrying Sector in Bulgaria

2019 ◽  
Vol 105 ◽  
pp. 04029
Author(s):  
Milena Tepavicharova ◽  
Lyudmila Dikova ◽  
Vitolds Zahars
Keyword(s):  
Human Resources ◽  
Resource Selection ◽  
Mining Industry ◽  
Competency Model ◽  
Extractive Industries ◽  
The Common ◽  
Personal Skills ◽  
Personal Orientation ◽  
Selection Of

The sophistication of technology, the globalization and the prolongation of active work age in recent decades require continuous adaptation of the workers’ personal skills and professional abilities. This is associated with a number of changes and challenges in the professional development. At present, in the mining industry organizations, the issue of lifelong careers is becoming more and more relevant, requiring a broad set of skills and knowledge. They provide the opportunity for a person to successfully find work, adapt and develop at their workplace, to cope with the professional tasks and to feel satisfaction and receive adequate remuneration for their work. Building a competency model for human resource selection requires targeted actions to improve certain skills and abilities. They represent the common language used by employers and employees, showing the quality of the individual’s social and personal orientation in the organizations. The purpose of this article is to identify the set of competencies and on this basis to create a competent model for the management of the human resources selection in the extractive industries in Bulgaria.

Seismic modeling and expression of common fold-thrust structures

2020 ◽  
Vol 8 (1) ◽  
pp. T55-T65
Author(s):  
Jianjun Li ◽  
Shankar Mitra
Keyword(s):  
Velocity Model ◽  
Fault Geometry ◽  
Seismic Modeling ◽  
Fault Propagation ◽  
Lateral Velocity ◽  
Slip Ratio ◽  
Velocity Models ◽  
Time Migration ◽  
The Common

We have conducted seismic modeling of common fold-thrust structures to understand the common geologic parameters influencing seismic data and to understand the common pitfalls associated with interpreting prestack time migration (PSTM) and prestack depth migration (PSDM) data. Mode 1 fault-bend folds are generally well-imaged in PSTM data, provided the correct migration velocities are used for the dipping back and front limbs. Seismic pull-ups of the footwall related to lateral velocity variations can result in problems in interpreting the fault geometry and the subthrust area underlying the crest. Fault-tip fault-propagation folds also show significant footwall pull-ups and show poor to no imaging of the steep front limbs. The geometry of trishear fault-propagation folds is dependent on the maximum slip on the fault (S) and the fault propagation to slip ratio (P/S ratio). We found that the slip has a strong influence on the dip of the front limb and therefore the quality of imaging whereas the P/S ratio, which controls the degree of folding versus thrust faulting, has only a secondary effect. For the front limb, only the area near the synclinal axial plan is well-imaged, so that the fault geometry and extent of propagation are typically difficult to interpret. The front limb dips are also sensitive to the accuracy of the rms velocity model used for migration. Lower velocities result in steeper dipping reflectors, whereas higher velocities result in shallower dips. In general, PSDM provides better imaging of the structures; however, the accuracy and quality of the image are dependent on the velocity models and interpretation derived from the PSTM data.

scholarly journals The selection of Islamic capitals: causes and motives

2018 ◽  
Vol 26 (2) ◽  
pp. 275-296
Author(s):  
Athary Ibraheam Alshuaibi Athary Ibraheam Alshuaibi
Keyword(s):  
Common Factors ◽  
Islamic History ◽  
Self Sufficiency ◽  
Geographic Factor ◽  
Key Factor ◽  
The Common ◽  
Military Politics ◽  
Basic Features ◽  
Islamic Civilization ◽  
Selection Of

Choosing a capital for any country or nation is a key factor in its organizational and economical composition. It also gives an impression about its social status and political vision. Most of the motives in choosing a capital for any country are usually unannounced. Researchers have to study that and link it to previous and next events to fully understand the reasons for choosing the capital of any nation. There were many states which ruled and led the Islamic nation world-wide or region-wide. Each of these states had a new capital usually made by them and different from the states before them. This process requires searching and studying from researchers for the motives of choosing the capital of any state. It also needs to be analyzed to discover the common reasons in choosing a capital in these states. For these reasons this study came to discuss the motives and to identify the common factors in choosing the capitals for the Islamic states. As a result, the researcher chose four capitals as a selected sample for the main Islamic caliphates and countries. These capitals are: Kufa, Damascus, Baghdad, and Cairo. The researcher divided the paper into four major parts, and tried through that to study the advantages of these capitals in different areas. These areas are : geography, strategy, military, politics, and economy. The researcher ended the paper with a conclusion which discussed the main results. Overall, the results show that the geographic factor is the most important reason in choosing a capital. Self-sufficiency in economic and food supply was also essential in choosing a capital so the capital does not require any help or support in general. The rulers did not ignore to choose a capital which is a center for their supporters or at least close to them. So, it is clear that choosing the Islamic capitals was done with a lot of efforts and planning. There were some basic features in choosing the capital which gave these states: political strength, and provided military, and economic importance to these states which allowed the capital to stay strong and thriving for long periods. key words: Islamic history - Islamic capitals - Islamic civilization.

scholarly journals Identification of the competences and skills of the good professional who works with older people via Deplhi technique

2015 ◽  
Vol 6 (1) ◽  
pp. 37-46
Author(s):  
Marga Vives ◽  
Carmen Orte ◽  
Lydia Sánchez
Keyword(s):  
Health Services ◽  
Older People ◽  
Health Professional ◽  
Health Professionals ◽  
Best Practice ◽  
Good Health ◽  
Health Area ◽  
Key Factor ◽  
Selection Of

Several handbooks and best practice guides, also scientific reference documents focus on the good treatment of the health services for older people take into account professionals as a key factor. However, there are few studies have been dedicated exclusively to them. This article is the result of a debate of a sample of health professionals who works with older people and of older people users of this health services using Deplhi methodology. Through different questionnaires we focus our attention in skills and competences that must have the good professional who attend to older people. The combination of the different point of views (professionals and users) enable us not only to get a proposal of these competences and skills that the “good” health professional must have and use, also these results could improve the selection of these professionals, improve the relationships between health professional and user and, ultimately improve the quality of the health service or program offered. The aim of this paper is to analyze the competences and basic skills of a good professional who works in health area with older people.

scholarly journals Factors Affecting Cost Overrun in Construction Projects

2019 ◽  
Vol 9 (2) ◽  
pp. 4831-4833
Keyword(s):  
Construction Projects ◽  
Basic Problem ◽  
Cost Overrun ◽  
Quality Cost ◽  
Factors Affecting ◽  
Critical Elements ◽  
Key Factor ◽  
The Common ◽  
The Cost

Cost overrun is observed as one of the common and basic problem which took place in different construction projects and affects its progress. Construction cost can be considered as the key factor to tell whether a project is successful or not. The cost of any project may be within, under or overrun. Among these cost overrun affects the project progress directly. Since it affects profit of the contractor, financial problems, delay in completion time, compromise on the material quality. Cost overrun can push the particular company to bankruptcy. Therefore various factors influencing the cost overrun must be thoroughly analyzed in order to reduce the cost overrun in such projects without compromising the quality of the project. The need of this research is to recognize the critical elements that lead to cost overrun in such projects.

scholarly journals Evaluating the Effect of Various Doses of Magnesium Sulfate on Quality of Cataract Intra Operative Sedation and Recovery

2017 ◽  
Vol 2 (2) ◽  
Keyword(s):  
Cataract Surgery ◽  
Magnesium Sulfate ◽  
Respiratory Effects ◽  
Patients Satisfaction ◽  
Significant Difference ◽  
The Common ◽  
Respiratory Variables ◽  
Selection Of ◽  
Narcotic Drugs

Background: The selection of sedative method for cataract surgery which is mostly done for adults is more favored. In this study, we compared various doses of magnesium sulfate for improving the quality of anesthesia and recovery during Cataract surgery. Materials and Methods: In this clinical trial, 150 patients candidate for Cataract surgery were studied in five groups of 30 individuals that 0(group 0), 10(group 10), 20(group 20), 30(group 30) and 40(group 40) mg/kg intravenous Magnesium Sulfate were added to the first to fifth groups at the onset of anesthesia in the common anesthetic method, respectively. The consumption doses of sedatives and narcotics (Midazolam, Fentanyl and Propofol), hemodynamic and respiratory variables during the surgery, and the incidence rate of pain, shivering, nausea and vomiting and the level of surgeon and patients’ satisfaction were studied in all groups. Results: 1) Demographic, hemodynamic and respiratory variables had no significant difference between the five groups. In the group 30 and 40, the consumption does of Midazolam, Propofol and Fentanyl was considerably less than that in other groups (P <0.001). 2) The highest and lowest levels of satisfaction in patients and physicians were recorded in the group 30 and respectively (P<0.001). 3) None of the patients suffered from postoperative shivering. 4) The incidence of other complications including nausea, vomiting and pain at time of discharging from the operating room had no significant difference between the 5 groups. Conclusions: Using Magnesium Sulfate, especially with the dose of 30 and 40mg/kg caused a significant reduction in need for sedative and narcotic drugs and increased satisfaction in patients and surgeons as well as minimal hemodynamic and respiratory effects during and after cataract surgery.

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