Minimum apertures and Fresnel zones in migration and demigration

Geophysics ◽  
1997 ◽  
Vol 62 (1) ◽  
pp. 183-194 ◽  
Author(s):  
Jörg Schleicher ◽  
Peter Hubral ◽  
Martin Tygel ◽  
Makky S. Jaya
Keyword(s):  
Fresnel Zone ◽  
Prestack Migration ◽  
Common Opinion ◽  
Correct Determination ◽  
The Common ◽  
The Cost ◽  
Fresnel Zones ◽  
Selection Of

The size of the aperture has an important influence on the results of (Kirchhoff‐type) migration and demigration. For true‐amplitude imaging, it is crucial not to have apertures below a certain size. For both the minimum migration and demigration apertures, theoretical expressions are established. Both minimum apertures depend on each other and, although a time‐domain concept, are closely related to the frequency‐dependent Fresnel zone on the searched‐for subsurface reflector. This relationship sheds new light on the role of Fresnel zones in the seismic imaging of subsurface reflectors by showing that Fresnel zones are not only important in resolution studies but also for the correct determination of migration amplitudes. It further helps to better understand the intrinsic interconnection between prestack migration and demigration as inverse procedures of the same type. In contrast to the common opinion that it is always the greatest possible aperture that yields the best signal‐to‐noise enhancement, it is in fact the selection of a minimum aperture that should be desired in order to (a) enhance the computational efficiency and reduce the cost of the summation, (b) improve the image quality by minimizing the noise on account of summing the smallest number of traces, and (c) to have a better control over boundary effects. This paper demonstrates these features rather than addressing the question of how to achieve them technically.

Determination of the minimum number of technological bases of a part

2020 ◽  
pp. 73-75
Author(s):  
B.M. Bazrov ◽  
T.M. Gaynutdinov
Keyword(s):  
Cost Price ◽  
Labor Input ◽  
Part Surface ◽  
Technological Base ◽  
Size Accuracy ◽  
Minimum Number ◽  
The Cost ◽  
Input Cost ◽  
Selection Of

The selection of technological bases is considered before the choice of the type of billet and the development of the route of the technological process. A technique is proposed for selecting the minimum number of sets of technological bases according to the criterion of equality in the cost price of manufacturing the part according to the principle of unity and combination of bases at this stage. Keywords: part, surface, coordinating size, accuracy, design and technological base, labor input, cost price. [email protected]

scholarly journals Role of Scaling Factor in Robust Digital Watermarking

2019 ◽  
Vol 8 (11) ◽  
pp. 1658-1669
Keyword(s):  
Digital Watermarking ◽  
Scaling Factor ◽  
Digital Data ◽  
Efficient Tool ◽  
The Cost ◽  
Human Eyes ◽  
The Empirical Analysis ◽  
Copyright Authentication ◽  
Selection Of

Digital watermarking has been identified as an efficient tool to provide copyright authentication and protection of digital data. Robustness and Imperceptibility are the two key parameters in designing of watermarking system. It is always desired to design a watermarking system that provides excellent robustness to malicious attacks and the watermark is invisible to human eyes. The robustness and imperceptibility can be controlled by choosing an effective scaling factor. Scaling factor decides on the amount of insertion of watermark in the host image. Higher the value of scaling factor more visible the watermark will be in watermarked image, this leads to poor imperceptibility. However the increase in scaling factor leads to a more robust watermarking system. Finding a trade-off among both is the key issue of research in this area. This paper aims at describing the effect of selection of scaling factor on robustness and imperceptibility by taking different values of scaling factor during each watermarking process. The empirical analysis done in this work shows robustness can be improved at the cost of imperceptibility and vice-versa.

Organizational and methodological aspects of the selection of a wheelchair for children with cerebral palsy

2021 ◽  
Vol 88 (2) ◽  
pp. 17-19
Author(s):  
Ye.V. Markelova ◽  
◽  
N.K. Zulina ◽  
O.I. Tomina ◽  
◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Rehabilitation Program ◽  
Children With Cerebral Palsy ◽  
Primary Disability ◽  
Correct Determination ◽  
Methodological Aspects ◽  
The City ◽  
Additional Fixation ◽  
Selection Of

The article gives definitions to the concepts of "rehabilitation", "habilitation", "individual rehabilitation program", "technical means of rehabilitation". The statistical data on primary disability of children with cerebral palsy in the city of Khabarovsk for the period 2016–2020 are presented. The characteristics of a wheelchair with additional fixation for patients with cerebral palsy are given. The requirements for the provision of disabled people with technical means of rehabilitation (wheelchairs) are noted, the principles of selection and the tasks that must be solved when using them are indicated. The method of correct determination of the parameters of the wheelchair is presented to help doctors of medical organizations in the preparation of referral documents for medical and social examination

Parametric Optimization of Structures Under Combined Base Motion Direct Forces and Static Loading

1998 ◽  
Vol 124 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Izhak Bucher
Keyword(s):  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Operating Conditions ◽  
Design Parameters ◽  
Power Spectral ◽  
Loading Patterns ◽  
The Cost ◽  
Selection Of ◽  
Eigenvectors And Eigenvalues

This paper deals with the optimization of vibrating structures as a mean for minimizing unwanted vibration. Presented in this work is a method for automatic determination of a set of preselected design parameters affecting the geometrical layout or shape of the structure. The parameters are selected to minimize the dynamic response to external forcing or base motion. The presented method adjusts the structural parameters by solving an optimization problem in which the constraints are dictated by engineering considerations. Several constraints are defined so that the static deflection, the stress levels and the total weight of the structure are kept within bounds. The dynamic loading acting upon the structure is described in this work by its power spectral density, with this representation the structure can be tailored to specific operating conditions. The uncertain nature of the excitation is overcome by combining all possible spectra into one PSD encompassing all possible loading patterns. An important feature of the presented method is its numerical efficiency. This feature is essential for any reasonably sized problem as such problems are usually described by thousands of degrees of freedom arising from a finite-element idealization of the structure. In this paper, efficient, closed form expressions, for the cost function and its gradients are derived. Those are computed with a partial set of eigenvectors and eigenvalues thus increasing the efficiency further. Several numerical examples are presented where both shape optimization and the selection of discrete components are illustrated.

INTERPRETATION OF THE RESULTS OF IMMUNOHEMATOLOGICAL TESTS IN HEMATOLOGICAL PATIENTS

2019 ◽  
Vol 64 (4) ◽  
pp. 221-224
Author(s):  
A. V. Yovdiy ◽  
E. V. Butina ◽  
E. A. Poponina ◽  
G. A. Zaitseva ◽  
N. V. Minaeva
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Blood Components ◽  
Blood Types ◽  
Hematological Patients ◽  
Correct Determination ◽  
Double Population ◽  
Transfusion Complications ◽  
Selection Of

The correct determination of the blood types of the recipient and the donor is very importante for the choice of blood components for transfusion. As a result of the study, it was established that 18.0% of patients, admitted to the hematology clinic, have difficulties in interpreting of the results of immunohematological tests. Most often, a double population of red blood cells was detected when determining antigens of the Rhesus system (10.9%), auto- (3.9%) and alloantibodies (2.8%). The proposed algorithm for the selection of donor red blood cells in difficult diagnostic cases helps to prevent the development of post-transfusion complications.

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.

scholarly journals Role of the esc+ gene product in ensuring the selective expression of segment-specific homeotic genes in Drosophila

Development ◽  
1983 ◽  
Vol 76 (1) ◽  
pp. 297-331
Author(s):  
Gary Struhl
Keyword(s):  
Gene Product ◽  
The Body ◽  
Homeotic Genes ◽  
Bithorax Complex ◽  
Sex Combs Reduced ◽  
Sex Combs ◽  
Correct Determination ◽  
Correct Expression

The product of the extra sex combs+ (esc+) gene is required during embryogenesis for the correct determination of segments in Drosophila. If this product is absent, most segments develop like the normal eighth abdominal segment. Here, I extend previous results (Struhl, 1981a) showing that this phenotype results in large part from indiscriminate expression of the bithorax-complex genes which are normally active only in particular segments of the thorax and abdomen. In addition, I test whether the esc+ gene product is required for the correct expression of other homeotic genes. First, I have examined two genes of the Antennapedia-complex (Sex combs reduced+ and Antennapedia+): I find that both genes are normally required in only some of the body segments, but that in the absence of the esc+ gene product, both appear to function adventitiously in other segments. Second, comparing esc+ and esc− embryos lacking both these genes as well as the bithorax-complex, I find that additional homeotic genes (possibly those normally involved in specifying head segments) appear to be expressed indiscriminately when the esc+ gene product is absent. Finally, I present evidence that the products of the esc+ gene and the Polycomb+ gene (a second gene required for the correct regulation of the bithorax-complex) act independently. On the basis of these results, I propose a tentative outline of the roles and realms of action of all of these genes.

scholarly journals The cost of evolved constitutive lac gene expression is usually, but not always, maintained during evolution of generalist populations

2021 ◽  
Author(s):  
Kelly Phillips ◽  
Tim Cooper
Keyword(s):  
Lac Operon ◽  
Beneficial Mutation ◽  
General Adaptation ◽  
Genetic Perturbations ◽  
Compensatory Mutations ◽  
Escherichia Coli Bacteria ◽  
The One ◽  
The Cost

Beneficial mutations can become costly following an environmental change. Compensatory mutations can relieve these costs, while not affecting the selected function, so that the benefits are retained if the environment shifts back to be similar to the one in which the beneficial mutation was originally selected. Compensatory mutations have been extensively studied in the context of antibiotic resistance, responses to specific genetic perturbations and in the determination of interacting gene network components. Few studies have focused on the role of compensatory mutations during more general adaptation, especially as the result of selection in fluctuating environments where adaptations to different environment components may often involve tradeoffs. We examine if costs of a mutation in lacI, which deregulated expression of the lac operon in evolving populations of Escherichia coli bacteria, was compensated. This mutation occurred in multiple replicate populations selected in environments that fluctuated between growth on lactose, where the mutation was beneficial, and on glucose, where it was deleterious. We found that compensation for the cost of the lacI mutation was rare, but, when it did occur, it did not negatively affect the selected benefit. Compensation was not more likely to occur in a particular evolution environment. Compensation has the potential to remove pleiotropic costs of adaptation, but its rarity indicates that the circumstances to bring about the phenomenon may be peculiar to each individual or impeded by other selected mutations.

scholarly journals Role of the PNPase enzyme in the transport of mtRNA in lymphatic cancer: Bibliographic review

2021 ◽  
pp. 99-112
Author(s):  
Myriam Lizanda Piqueras ◽  
Ignacio Ventura González
Keyword(s):  
Lymphatic System ◽  
Common Type ◽  
Mitochondrial Rna ◽  
Scientific Publications ◽  
Genetic Characteristics ◽  
H Index ◽  
Mitochondrial Defects ◽  
Selection Of

Lymphoma is the most common type of blood cancer today and, as its name suggests, it begins in the lymphatic system. The origin of this disease is related to mitochondrial defects, generated by mutations in the PNPase enzyme or polynucleotide phosphorylase, whose main functions are to import and degradation mitochondrial RNA. For this reason, the main objective of the present work was to carry out a bibliographic review of scientific publications that made the role of this enzyme relevant, in relation to mitochondria as the cause of lymphatic cancer. The methodology used consisted of a bibliometric analysis based on the use of different databases, in which search equations formed from keywords were introduced. Then, the selection of articles related to the study topic and published in the last 20 years was carried out. Subsequently, the journals were analyzed, based on the H index, in order to observe which supported the hypothesis of the role of PNPase in lymphoma and which stated the opposite. The results showed that a total of 441,288 scientific publications were obtained, of which 133 were selected to carry out this work. As for the journals, those with the highest H index were Nature and Cell. It can be concluded that PNPase plays a very important role in the transport of mitochondrial RNA, and that the factor NF-Y is involved in the control of cell growth, therefore, both have a crucial role in the development of this disease. Therefore, research on both PNPase and NF-Y is essential to establish the specific genetic characteristics that define the early lesions of lymphatic cancer and the consequent determination of their treatment.

scholarly journals KERAGAAN AGROINDUSTRI DAN POSISI PRODUK BERDASARKAN SIKLUS HIDUP PRODUK PADA SOSIS GULUNG VARIAN NOODLE DI CV CUCURUTUKU CERIA

2021 ◽  
Vol 9 (4) ◽  
pp. 561
Author(s):  
Meliani Indah Sari ◽  
Dyah Aring Hepiana Lestari ◽  
Wuryaningsih Dwi Sayekti
Keyword(s):  
Life Cycle ◽  
Product Life Cycle ◽  
Production Costs ◽  
Selling Price ◽  
Long Time ◽  
The Government ◽  
The Cost

This study aims to analyze the process production of sausage noodle roll, the income and production costs, the marketing action and determine the position based on the life cycle of sausage noodle roll as well learn the role of supporting service for sausage noodle roll in CV Cucurutuku Ceria. This research method is a case study. The determination of consumer samples is taken by Convenience Sampling. Analysis of the data used in this research is descriptive qualitative and quantitative analysis. The data of this study was collected in May 2019 until June 2019. The results showed that the value R/C>1, that means sausage noodle roll business was profitable. Calculation of the cost of production on sausage rolls noodles amounted to Rp1,046.53. The BEP unit calculation has been achieved for a long time, in the amount of 42,791 units from the BEP calculation of 604 units. The noodle rolls sausage has also obtained a profit from the selling price of Rp ,000.00 per pcs from the calculation of the BEP price of Rp1,238.58 per pcs. The marketing mix that has been utilized by CV Cucurutuku Ceria is collaboration with e-commerce companies namely gofood and grabfood to facilitate consumers in the ordering process and CV Cucurutuku Ceria has utilized social media as promotional activities for sausage noodle roll product. In the product life cycle, sausage noodle roll are in a stage of decline. CV Cucurutuku Ceria has not fully utilized the government policies regarding the protection and empowerment of Micro, Small and Medium Enterprises.Keywords: cost, noodle, position, and sausage

Sign in / Sign up

Export Citation Format

Share Document