scholarly journals Diffractive Sensor Elements for Registration of Long-Term Instability at Writing of Computer-Generated Holograms

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6635
Author(s):  
Ruslan V. Shimansky ◽  
Dmitrij A. Belousov ◽  
Victor P. Korolkov ◽  
Roman I. Kuts
Keyword(s):  
Mathematical Modeling ◽  
Research And Development ◽  
Experimental Test ◽  
Writing Systems ◽  
Laser Writing ◽  
Computer Generated Holograms ◽  
Errors Estimation ◽  
Writing Errors ◽  
Orthogonal Coordinates

The research and development of methods using of the specialized diffractive microstructure sensors embedded in the pattern of computer-generated holograms (CGH) manufactured on circular and X-Y laser writing systems is discussed. These microstructures consist of two parts: one of which is written before the CGH in the field of future hologram and the second one is written during the long-term writing of the CGH. The shift between the first and second part of the microstructure is the trace of the writing errors and allows one to determine and calculate the error of CGH fabrication along both orthogonal coordinates. The developed method is based on the principle of diffraction-based overlay with 1D and 2D built-in diffractive microstructure-sensors. Mathematical modeling and results of experimental test writings of such diffractive microstructure sensors are described. The efficiency of using these types of build-in sensors for the writing errors estimation for CGHs is demonstrated.

Controlling the accuracy of fabricating computer-generated holograms on circular and X-Y laser writing systems

2021 ◽  
Author(s):  
Ruslan V. Shimansky ◽  
Dmitrij A. Belousov ◽  
Roman I. Kuts ◽  
Victor P. Korolkov
Keyword(s):  
Writing Systems ◽  
Laser Writing ◽  
Computer Generated Holograms

Application of the method of mathematical modeling for forecasting channel deformations at the underwater crossing of the main pipeline

2020 ◽  
Vol 10 (6) ◽  
pp. 599-609
Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Roughness Coefficient ◽  
Computational Domain ◽  
Channel Deformations ◽  
Geological Surveys ◽  
Kuban River ◽  
The Stability ◽  
Protective Structures

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.

scholarly journals A long-term, spatially replicated experimental test of the effect of marine reserves on local fish yields

2005 ◽  
Vol 62 (1) ◽  
pp. 98-108 ◽  
Author(s):  
Angel C Alcala ◽  
Garry R Russ ◽  
Aileen P Maypa ◽  
Hilconida P Calumpong
Keyword(s):  
Coral Reefs ◽  
Experimental Test ◽  
Marine Reserves ◽  
Fish Biomass ◽  
Total Catch ◽  
Target Fish ◽  
Fish Yields

Do no-take marine reserves affect fishery yields? Manipulations of reserve status, and yield estimates, were made at two Philippine islands over two decades. Twenty-five percent and ten percent, respectively, of the coral reefs at Sumilon and Apo islands were made no-take reserves in 1974 and 1982. Biomass of target fish increased inside the no-take reserves 3- to 4.5-fold over 9–18 years. Biomass did not increase outside each reserve. Protection of the Sumilon reserve ceased in 1984. Biomass of targeted fish in the reserve and trap and gillnet catches of these fish declined by 42.7% and 40%, respectively, by 1985. The reserve was reprotected from 1987 to 1991 and from 1995 to 2001. Fish biomass increased in the reserve by 27.2%. Trap and gillnet catches outside the reserve increased 26.9% by 2001. The Apo reserve was protected from 1982 to 2001. Total catch of major fish families was significantly higher after (1985–2001) than before (1981) reserve establishment at Apo, increasing 41.3% between 1981 and 1998–2001. These experiments, plus spillover evidence, suggest that marine reserves may help maintain, or even enhance, local fishery yields in the long-term.

Mathematical modeling of fluid movement inside the eyeball during intravitreal injection

2021 ◽  
pp. 106-109
Author(s):  
D.V. Lipatov ◽  
◽  
S.A. Skladchikov ◽  
N.P. Savenkova ◽  
V.V. Novoderezkin ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Residence Time ◽  
Complex Structure ◽  
Posterior Vitreous Detachment ◽  
Vitreous Body ◽  
Complete Removal ◽  
Intravitreal Injections ◽  
The World

Background. The avalanche-like growth of intravitreal injections in the world has significantly increased interest in the hemodynamics of the processes that occur in the eye when a drug is injected into the vitreous cavity. Every year, the number of intravitreally used drugs and promising areas in which they can be used is growing. This also applies to the creation of new combined medicines and the development of drugs with a long-term therapeutic effect. Aims. Create mathematical model of eyeball to evaluate the movement of the drug substance in it; to estimate the time of the drug's presence in the eye cavity before its complete removal, to characterize the ways of its removal from the eye cavity; to assess the significance of posterior vitreous detachment during the time when the drug is present in the eye cavity; to evaluate the effect on the hydrodynamics of the depth of drug administration. Results. When the drug is administered closer to the center of the eyeball, its residence time increases in comparison with the parietal administration. With a complete posterior detachment of the vitreous body, the time of finding the drug in the eye is prolonged compared to its absence. The obtained results of mathematical modeling of the movement of the drug administered intravitreally cannot be mechanically transferred to the human eye, due to the more complex structure of the latter. Key words: intravitreal injections, vitreous body, mathematic computing.

BIOMEDICAL RESEARCH PAYS OFF

PEDIATRICS ◽  
1977 ◽  
Vol 59 (6) ◽  
pp. 832-832
Author(s):  
J. H. Comroe ◽  
R. D. Dripps
Keyword(s):  
Research And Development ◽  
Biomedical Research ◽  
Basic Research ◽  
The Other ◽  
Human Diseases ◽  
Different Types ◽  
Living Organisms

Our analysis showed . . . 41% of all work judged to be essential for later clinical advance was not clinically oriented at the time it was done. The scientists responsible for these key articles sought knowledge for the sake of knowledge. . . . Our data show that clinical advance requires different types of research and development and not one to the exclusion of the other. . . . Our data compel us to conclude (1) that a generous portion of the nation's biomedical research dollar should be used to identify and then provide long term support for creative scientists whose main goal is to learn how living organisms function, without regard to the immediate relation of their research to specific human diseases; and (2) that basic research, as we have defined it, pays off in terms of key discoveries almost twice as handsomely as other types of research and development combined.

Investing for Growth and Security

2019 ◽  
pp. 193-206
Author(s):  
William G. Gale
Keyword(s):  
United States ◽  
Research And Development ◽  
Interest Rates ◽  
Federal Government ◽  
The United States ◽  
Federal Spending ◽  
President Obama ◽  
Transit Systems ◽  
Historical Levels

Besides its investment in people, the federal government makes critical investments in infrastructure and research and development. Because federal spending in these areas has fallen significantly in recent years and interest rates are low relative to historical levels, this chapter proposes sizable increases for both categories. The increases in infrastructure spending will provide the resources needed to restore and update aging roads, bridges, and public transit systems, while the increases in research and development will help the United States to explore cutting-edge technologies. Policymakers should also fund the military’s long-term plans through 2032, as outlined by President Obama, and let spending grow modestly afterward. That would allow for a continuing presence overseas. If a new war broke out, policymakers presumably would provide the additional temporary funds to ensure that America achieved its mission and emerged victorious.

Phase Analysis in Computer-Generated Hologram Induced by Direct Laser Writing Systems with Orthogonality Error

2016 ◽  
Vol 36 (10) ◽  
pp. 1012005 ◽  
Author(s):  
郑立功 Zheng Ligong ◽  
郝腾 Hao Teng ◽  
国成立 Guo Chengli ◽  
王若秋 Wang Ruoqiu ◽  
张志宇 Zhang Zhiyu
Keyword(s):  
Phase Analysis ◽  
Direct Laser Writing ◽  
Writing Systems ◽  
Laser Writing ◽  
Computer Generated Hologram ◽  
Direct Laser
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