Deterministic IMAC revisited: Constant-gap capacity in the weak interference case

Two experiments were conducted in order to determine the nature of the difficulties encountered by learning disabled (LD) adolescents in the resolution of multiplication problems ( a b, where a and b vary between 2 and 9). A response production task (Experiment 1) revealed that the incorrect responses generally belonged to the table of one of the two operands, and that the order of difficulty of the problems was the same for the LDs as for normal children, adolescents, and educated adults as reported in the literature. This result suggests that the difficulties are not solely due to memory problems. Experiment 2 tested the hypothesis that these difficulties were caused by a problem in inhibiting the incorrect responses from a set of possible responses. Subjects completed a multiple response task in which the correct response was presented along with three distractors. The level of interference between the correct response and the distractors was varied by manipulating the nature of the distractors (Null Interference, NI: numbers that did not belong to the multiplication table; Weak Interference, WI: numbers belonging to other tables than those of a and b; Strong Interference, SI: numbers belonging to the tables of either a or b). The SI condition resulted in a higher level of errors than the NI and WI conditions and there was no difference between these latter two conditions. This result suggests that the main difficulty encountered by LD subjects is associated with inefficient inhibition of incorrect responses. Thus, the mobilisation of inhibitory processes seems to be an important stage in the development of multiplication skills.

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Research on multi-channel weak interference signal detection circuit of Fourier transform infrared spectrometer

10.1117/12.2606960 ◽

2021 ◽

Author(s):

Ruilin Ding ◽

Huiqin Shu ◽

Peizhong Zhang ◽

Jian Cui ◽

Zhaoyang Guan ◽

...

Keyword(s):

Fourier Transform ◽

Signal Detection ◽

Fourier Transform Infrared ◽

Interference Signal ◽

Detection Circuit ◽

Fourier Transform Infrared Spectrometer ◽

Infrared Spectrometer ◽

Weak Interference

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A Preliminary System to Predict Snow Instability using Acoustic Emissions

Journal of Glaciology ◽

10.1017/s002214300001114x ◽

1980 ◽

Vol 26 (94) ◽

pp. 520

Author(s):

R. A. Sommerfeld

Keyword(s):

Narrow Band ◽

Signal To Noise Ratio ◽

Acoustic Emissions ◽

Digital Data ◽

Signal To Noise ◽

Data Manipulation ◽

Wide Range ◽

Stressed Region ◽

Power Line Noise ◽

Weak Interference

Abstract Results From the last four winters’ studies on acoustic emissions from snow slopes have shown that periods of higher noise in the frequency band 5 to 125 Hz are associated with periods of instability, but that the phenomenon of acoustic emissions from unstable snow is very weak. Interference with the acoustic emissions from extraneous sources such as chairlifts, trucks, and airplanes causes ambiguities in the data which interfere with the straightforward prediction of instability. Spectra of the noises were examined, with the idea that filters might improve the signal-to-noise ratio. It was found that the noise generated by unstable snow can occur over a fairly wide range of frequencies and that there is no band of frequencies which is unique to unstable snow. It was found that the noise from the chairlift had a very stable spectrum and that it had a band from 50 to 65 Hz which was pronounced and in which the snow noise was fairly low. The r.m.s. voltage in the band 5 to 125 Hz can therefore be reduced by subtracting a proportion of the r.m.s. output of a narrow-band 55 Hz filter. By adjusting the constant of proportionality, it was possible to eliminate interference from the chairlift almost entirely, and this will be used. Spectral analyses have also shown that ambiguities are generated by variations in the 60 Hz power-line noise. It is possible to suppress this with the use of filters, but without complex digital data manipulation, it is not possible to eliminate it. The fact that the snow noise does not transmit over large distances means that events of interest should not occur simultaneously on two, widely spaced geophones. The system will include a geophone in an unstressed region whose r.m.s. voltage will be subtracted from that of the geophone in the stressed region to eliminate signals which are common to both. It is hoped that this technique will eliminate ambiguities caused by extraneous sources such as trucks and airplanes.

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Supplementary notes on the mineral Kaolinite

Mineralogical Magazine and Journal of the Mineralogical Society ◽

10.1180/minmag.1908.015.69.03 ◽

1908 ◽

Vol 15 (69) ◽

pp. 124-127 ◽

Cited By ~ 3

Author(s):

Allan B. Dick

Keyword(s):

Basal Plane ◽

Numerical Aperture ◽

Angular Aperture ◽

Axial Angle ◽

Oil Immersion ◽

Mineralogical Society ◽

Weak Interference

In the year 1888 I gave before the Mineralogical Society an account of the forms and optical characters of some minute crystals of kaolinite from Anglesey. At that time I was unable to ascertain whether the mineral was optically positive or negative, and it was stated that the axial angle 2V would approximate to 90°. Subsequently, by the aid of oil-immersion lenses and condensers of high angular aperture (numerical aperture=1.25), it was found that the mineral is optically positive and that the acute bisectrix is normal to the clinopinacoid (the obtuse negative bisectrix emerging through the basal plane). The optic axial angle in air was determined with an eyepiece micrometer to be 2E = 121°, with a possible error of one or two degrees, due to the small size of the crystals and the consequent weak interference-figures.

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Analysis of Capacity Bound on Two-User Transmitter Preprocessing Weak Interference MIMO Channels

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.694-697.2564 ◽

2013 ◽

Vol 694-697 ◽

pp. 2564-2567

Author(s):

Mang Liao ◽

Meng Xing Wang ◽

Ling Xu Jin

Keyword(s):

Information Theory ◽

Open Problem ◽

Interference Channels ◽

Capacity Region ◽

Mimo Channels ◽

Sum Rate ◽

Simulation Results ◽

Capacity Bound ◽

Weak Interference

In information theory (IT), it is an open problem for thirty years to establish an entire capacity bound of two-user Gaussian weak interference network. Under the assumption that channel situation information (CSI) is known at transmitter, we analyze the effects of three methods of transmitter preprocessing on performance of weak interference MIMO channels. Due to treat weak interference as noise, the bounds on the capacity region of two-user Gaussian weak interference channels (ICs) with the three transmitter preprocessing methods are derived. Compared with the performance without transmitter preprocessing, the sum rate in our system is larger. Finally the simulation results are proposed to be consistent with the theorem.

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