Limitation of m.t.i. improvement factor due to oscillator instability

1973 ◽  
Vol 9 (20) ◽  
pp. 470
Author(s):  
R. Nitzberg
2001 ◽  
Vol 7 (S2) ◽  
pp. 148-149
Author(s):  
C.D. Poweleit ◽  
J Menéndez

Oil immersion lenses have been used in optical microscopy for a long time. The light’s wavelength is decreased by the oil’s index of refraction n and this reduces the minimum spot size. Additionally, the oil medium allows a larger collection angle, thereby increasing the numerical aperture. The SIL is based on the same principle, but offers more flexibility because the higher index material is solid. in particular, SILs can be deployed in cryogenic environments. Using a hemispherical glass the spatial resolution is improved by a factor n with respect to the resolution obtained with the microscope’s objective lens alone. The improvement factor is equal to n2 for truncated spheres.As shown in Fig. 1, the hemisphere SIL is in contact with the sample and does not affect the position of the focal plane. The focused rays from the objective strike the lens at normal incidence, so that no refraction takes place.


2013 ◽  
Vol 11 (1) ◽  
pp. 8-13
Author(s):  
V. Behar ◽  
V. Bogdanova

Abstract In this paper the use of a set of nonlinear edge-preserving filters is proposed as a pre-processing stage with the purpose to improve the quality of hyperspectral images before object detection. The capability of each nonlinear filter to improve images, corrupted by spatially and spectrally correlated Gaussian noise, is evaluated in terms of the average Improvement factor in the Peak Signal to Noise Ratio (IPSNR), estimated at the filter output. The simulation results demonstrate that this pre-processing procedure is efficient only in case the spatial and spectral correlation coefficients of noise do not exceed the value of 0.6


Author(s):  
V. G. Bartenev ◽  
M. V. Bartenev ◽  
V. K. Bityukov

The comparative analysis of the effectiveness of methods for implementing adaptive systems moving target based on autoregression approach. AR model correlated noise can effectively deal with clutter, without resorting to the algorithm based on the correlation matrix inversion. Considered several methods of weight factor of adaptive systems moving target, which is used as the coefficients of the autoregression. One of the main parameters that determine the effectiveness of the systems being compared, is the improvement factor, which was used in this study.


2019 ◽  
Vol 12 (4) ◽  
pp. 503-513 ◽  
Author(s):  
Torkild Eriksen ◽  
Øystein Helleren ◽  
Andreas Nordmo Skauen ◽  
Frode A. S. Storesund ◽  
Anders Bjørnevik ◽  
...  

AbstractTwo Norwegian AIS-satellites, NorSat-1 and NorSat-2, were launched in July 2017. Both are equipped with the ASR x50, the latest space-AIS receiver developed by Kongsberg Seatex AS, offering advanced signal processing and continuous operation on all four AIS channels. The NorSat-satellites collect ~ 1.5 million messages from ~ 50,000 ships per day (24 h) each, which is a factor ~ 2.8 increase in the number of messages compared to the ASR 100 on-board AISSat-1 and AISSat-2. The improvements of the AIS-satellites can be attributed to three developments: the performance of the receiver, the use of antenna diversity, and the use of frequency channel diversity. Daily statistics for February 2018 over the Mediterranean Sea illustrate the improvements: The median value of the number of messages received with NorSat-1 using only one antenna is 2.3 times higher than for AISSat-1. When both NorSat-1 antennas are used, the improvement factor becomes 4.1, and finally, when two additional receiver channels are used to collect long-range AIS messages, the total improvement becomes 8.2 times. In terms of ships detected, the factors are 1.8, 2.7, and 4.4 for the respective steps. Long-range AIS messages amount to just 5% of the total AIS messages received by NorSat-1 in August 2017, but it allows to detect 20% more ships on a global scale, and as much as 10 times more ships in a the high-traffic area in the North Sea.


1992 ◽  
Vol 114 (4) ◽  
pp. 459-463 ◽  
Author(s):  
Yuan Mao Huang

The one-dimensional, unsteady flow in an air-to-air heat exchanger is studied. The governing equations are derived and the method of characteristics with the uniform interval scheme is used in the analysis. The effect of the fin improvement factor on the air temperature in the heat exchanger and the heat transfer rate of the heat exchanger, and air properties in the heat exchanger are analyzed. The numerical results are compared and show good agreement with the available data.


2005 ◽  
Author(s):  
Kenji Morita ◽  
Kazuki Shimamura ◽  
Gen Sugiyama ◽  
Masahiko Hori ◽  
Yukihiko Itai ◽  
...  

2011 ◽  
Vol 19 (3) ◽  
pp. 17-21 ◽  
Author(s):  
J. Pivarč

Stone Columns - Determination of the soil improvement factorA stone column is one of the soil stabilizing methods that is used to increase strength, decrease the compressibility of soft and loose fine graded soils, accelerate a consolidation effect and reduce the liquefaction potential of soils. The columns consist of compacted gravel or crushed stone arranged by a vibrator. This paper deals with Priebe's theory (1976) on the design of an improvement factor, which belongs among the most used analytical methods and also describes the numerical and laboratory models of stone columns. The improvement factors calculated from numerical and laboratory models are compared with the improvement factors resulting from Priebe's theory.


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