Search

I give a simple analysis of the game that I previously published in Scientific American which shows the paradoxical behavior whereby two losing games randomly combine to form a winning game. The game, modeled on a random walk, requires only two states and is described by a first-order Markov process.

We consider the problem of identifying multivariable finite dimensional linear time-invariant systems from noisy input/output measurements. Apart from the fact that both the measured input and output are corrupted by additive white noise, the output may also be contaminated by a term which is caused by a white input process noise; furthermore, all these noise processes are allowed to be correlated with each other. We shall develop a solution to this problem in the framework of subspace identification and we shall show that our algorithms give consistent estimates when the system is operating in open- or closed-loop. Two realistic simulation studies are presented to demonstrate the practical applicability of the proposed algorithms. © 1997 Elsevier Science Ltd.

Low-frequency noise caused by intestinal gas, bone, or high-contrast subjects on roentgenographs often makes them difficult to read. The plantodorsal projection of the calcaneus taken by the conventional method has low-frequency noise because of its own high contrast for the long axis. Even if a higher X-ray tube voltage is used to reduce the low-frequency noise, middle- or high-frequency signals such as those of bone trabeculae are also reduced. We investigated a new method that takes into consideration the subject contrast between the part of the posterior calcanean articulation and distal part on the calcaneus projection, the spectrum of bone trabeculae, and the scatter fraction. The technique we introduced has some merit compared with the conventional method in that it reduces image distortion, provides low contrast for the long axis, and sharpens trabeculae images and articulations.

Glitches and errors within digital media technology are hardly ever greeted gladly. Hardware failures, signal losses, and corrupt files have the potential to be personally and professionally catast...

Two-phase flow exists in many industrial components. To avoid costly vibration problems, sound technology in the area of two-phase flow-induced vibration is required. This paper is an overview of the principal mechanisms governing vibration in two-phase flow. Dynamic parameters such as hydrodynamic mass and damping are discussed. Vibration excitation mechanisms in axial flow are outlined. These include fluidelastic instability, phase-change noise, and random excitation. Vibration excitation mechanisms in cross-flow, such as fluidelastic instability, periodic wake shedding, and random excitation, are reviewed.

A dynamic model for basis weight variations in paper machines is established and estimated recursively from scanned measurements using a combination of an exponential forgetting and resetting least squares estimator and an extended Kalman filter. The algorithm provides online estimation of basis weight variations in both cross-machine direction and machine direction, as well as estimates of the dynamic parameters and noise characteristics of the process. >

Children with listening difficulties, but normal audiometry, may be diagnosed with APD. The diagnosis is typically based on poor performance on tests of perception of both non-speech and speech stimuli. However, non-speech test results correlate only weakly with evaluations of speech-in-noise processing, cognitive skills, and caregiver evaluations of listening ability. The interpretation of speech test results is confounded by the involvement of language processing mechanisms. Overall, listening ability is associated more with higher-level, cognitive and analytic processing than with lower-level sensory processing. Current diagnosis of a child with APD, rather than another problem (e.g. language impairment, LI), is determined more by the referral route than by the symptoms. Co-occurrence with other learning problems suggests that APD may be a symptom of a more varied neurodevelopmental disorder. Alternately, APD has been proposed as a cause of language-based disorders, but there is no one-to-one mapping between listening and language among individuals. Screening for APD may be most appropriately based on a well-validated, caregiver questionnaire that captures the fundamental problem of listening difficulties and identifies areas for further assessment and management. This approach has proved successful for LI, and may in future serve as a metric to help assess other, objective testing methods.

In this paper, the performances and limitations related to the high frequency noise properties of SOI MOSFET Technology are investigated. The study is conducted through powerful analytical noise parameters calculation, experimental data, and physical based drift-diffusion noise modeling. In addition to the noise generated by the inner part of the active device, the influence of access resistances, overlap/fringing capacitances, tunneling gate current are discussed qualitatively and quantitatively. The paper ends up with a critical discussion related to the "New Era SOI Technology" to come and its influence on the noise performance.

Introduction This study planned to investigate the occurrence time of noise induced hearing loss (NRHL) among workers in a loud work environment. Material and Methods For this study, the data of 70 workers who work in different departments of a paper factory was examined retrospectively. Workers were allocated in two groups as A (environment’s noise level is under 80 dB) and B (over 85 dB) according to their departments’ noise level. The workers with noise induced hearing loss were determined with the last Pure Tone Audiogram results. Results The median age was 36.98 of 70 workers included 2 females and 68 males. 15 workers with hearing loss were determined. Group B showed twice as many hearing loss results compared to the group A (5 in A and 10 in B groups), however, these results were not found to be statistically significant (p: 0.244). In the examination of the number of workers with noise induced hearing loss distributed by the years spent in this workplace, 14 of the workers who have been working in the factory over 10 years had hearing loss while only 1 worker in the group with up to 10 years of experience was affected. The difference of this distribution was statistically significant (p: 0.002). Conclusion The data of this study shows that there is a positive correlation between hearing loss incidence and years of service in a loud workplace. Particularly, individuals with over 10 years of experience show distinctive increase of hearing loss. Years spent in a loud workplace and accordingly, the amount of time being exposed to loud noise, increase the noise induced hearing loss.

A highly manufacturable 25nm 64Gb NAND technology has been developed. Many physical and electrical scaling challenges were overcome. Severe scaling challenges have to be overcome to continue NAND scaling.

Acoustic emission or crackling noise is measured from an experiment on splitting or peeling of paper. The energy of the events follows a power-law, with an exponent $\beta \sim 1.8\pm 0.2$. The event intervals have a wide range, but superposed on scale-free statistics there is a time-scale, related to the typical spatial scale of the microstructure (a bond between two fibers). Since the peeling takes place via steady-state crack propagation, correlations can be studied with ease and shown to exist in the series of acoustic events., Comment: one separate figure

This paper considers identification of the cross-directional (CD) response of the paper machine from the input-output data. In particular, the paper is devoted to identification of the mapping between the CD actuators and the scanned profiles of the paper properties taking into account effects of paper shrinkage and misalignment. We describe a novel approach to identification of alignment and shrinkage using advanced optimization technology. The approach allows us to achieve reliable identification of alignment and shrinkage within 10-20 scans of the profile data, despite the process noise. Instead of averaging only in machine direction (MD), as it is commonly done for classic bump tests to determine bump centers, we compute model fit error for the entire array of data. Such design of the algorithms effectively averages out the noise in both MD and CD which results in much better noise rejection, improved accuracy, and much shorter required test interval than classical bump test methods.

The problem of estimating state variables and parameters is considered for discrete-time systems in the presence of random disturbances and measurement noise. The solution of the linear problem is given and an approximation technique is developed for nonlinear systems. A dynamic programming formulation of the estimation problem is also developed.

Functional requirements for modern narrow-band and wide-band wireless and lightwave communication systems place stringent demands on speed and noise behavior of circuits and devices used to design them. MOS technology in the nanometer regime continues to be the low-cost high-performance workhorse driving innovations for these applications. In this paper, we trace the developments in the modeling of noise in MOS transistors as the device channel lengths shrink by a factor or a thousand from tens of micrometers to tens of nanometers. The impact of scaling on classical noise mechanisms is explained. Also, generation of new noise sources as a result of scaling are also described. This leads to a better physical understanding of the noise behavior of these devices. Methods of eliminating some of these noise sources by suitable choice of materials and modifications in device structure are explained. Application of this understanding to the practical design and layout of low-noise high-performance circuits is illustrated. As a result, the noise performance of MOS devices has improved by almost an order of magnitude making them an ideal choice for low-noise communication electronics design. Research continues as the channel lengths shrink further.

QFT is an engineering design theory devoted to the practical design of feedback control systems. The foundation of QFT is that feedback is needed in control only when plant (P), parameter and/or disturbance (D) uncertainties (sets P; = {P}, D = {D}) exceed the acceptable (A) system performance uncertainty (set A ={A}). The principal properties of QFT are as follows. (1) The amount of feedback needed is tuned to the (P,D,A); sets. If A/ 'exceeds’ (P,D)feedback is not needed at all. (2) The simplest modelling is used: (a) command, disturbance and sensor noise inputs, and (b) the available sensing points and the defined outputs. No special controllability test is needed in either linear or non-linear plants. It is inherent in the design procedure. There is no observability problem because uncertainty is included. The number of independent sensors determines the number of independent loop transmissions (Li,,), the functions which provide the benefits of feedback. (3) The simplest mathematical tools h...

In assessing the status of acoustics in Nigeria, efforts have been made to review the work of researchers of various nationalities, appraise the role of some countries of the world vis-a-vis that of the Federal Republic of Nigeria in promoting anti-noise laws, ordinances and other governmental acoustical matters that bother on noise. Expounded in this study are the published works of many Nigerians in acoustical physics as pioneered by Professor Alex I. Menkiti, the honoree. The different areas are architectural and room acoustics, environmental noise pollution and control, traffic noise, community and indoor noise, industrial and occupational noise, and atmospheric and jungle acoustics. Results have shown characteristics of some available local materials that could find application in vibration and structure-borne noise isolation. Most of the results in environmental acoustics have also characterized cities where the investigations were conducted with remarkable consistency with those of early surveys with similar features. It is believed that acoustical research in Nigeria will be given more attention and greater impetus in future. Keywords : Acoustics, Nigeria, traffic noise, environmental acoustics and jungle acoustics. Nigerian Journal of Physics Vol. 19 (1) 2007: pp. 139-180

Finished wrapping all your Christmas presents? Still have some paper to spare? Don’t throw it away – your child will love to play with it, enjoying the feel of it in their hands and the noise it makes

Acoustic emission experiments in paper, a disordered material, give evidence for power‐law probability distributions of statistical quantities as event energies or intervals. Two setups, usual mode I tensile tests and a nip‐in‐peel one have been studied in our work. In both cases, even using the same material, we observe “criticality”. This has wide implications for theories of statistical fracture.

The silent dryer drive (SDD) concept is described. The concept involves driving the dryers through the fabric, thus eliminating the large gear cases and decreasing the noise in the dryer section. The benefits of the SDD include: (1) simplified-framing; (2) equal baseplate loading, front and back; (3) improved air flow around the dryers; (4) broke removal improvements; (5) restoration of normal machine speed and maintenance practice; (6) greater uniformity of interdryer draws; (7) noise reduction; (8) tight tuning due to lack of gear backlash; (9) better acceleration and deceleration; and (10) improved lubrication system operation. >

A dynamic model for basis weight variations in paper machines is established and estimated recursively from scanned measurements using a combination of an exponential forgetting and resetting least squares estimator and an extended Kalman filter. The algorithm provides online estimation of basis weight variations in cross-machine direction and machine direction, as well as estimates of the dynamic parameters and noise characteristics of the process. >

This paper considers the effect of noise on the quality of convergence of genetic algorithms (GAs). A population-sizing equation is derived to ensure that minimum signal-to-noise ratios are favorable to the discrimination of the best building blocks required to solve a problem of bounded deception. In five test problems of varying degrees of nonlinearity, nonuniform scaling, and nondeterminism, the sizing relation proves to be a conservative predictor of average correct convergence. These results suggest how the sizing equation may be viewed as a coarse delineation of a boundary between two distinct types of GA behavior. Besides discussing a number of extensions of this work, the paper discusses how these results may one day lead to rigorous proofs of convergence for recombinative GAs operating on problems of bounded deception.

A dynamic model for basis weight variations in paper machines has been developed. The model is identified recursively from scanned measurements, and so provides an online estimation of basis weight variations in both cross-machine direction and machine direction, as well as estimates of the dynamic parameters and noise characteristics of the process. Here the approach is extended to include the adaptive generalized prediction control (GPC) algorithm for machine direction variations of the basis weight process. The adaptive controller is designed to overcome shortcomings of the nonadaptive traditional controllers being used. >

We show how the semiclassical Langevin method can be extended to calculations of higher-than-second cumulants of noise. These cumulants are affected by indirect correlations between the fluctuations, which may be considered as "noise of noise." We formulate simple diagrammatic rules for calculating the higher cumulants and apply them to mesoscopic diffusive contacts and chaotic cavities. As one of the application of the method, we analyze the frequency dependence of the third cumulant of current in these systems and show that it contains additional peculiarities as compared to the second cumulant. The effects of environmental feedback in measurements of the third cumulant are also discussed in terms of this method.

We have previously advocated the deliberate addition of noise to cochlear implant signals to enhance the speech comprehension of cochlear implant users. The function of the additive noise is to mimic noise sources that are present in a healthy ear (originating, for example, from Brownian motion of the hair cells and the fluctuations induced by the opening and closing of ion channels) but are largely absent in a deafened ear where the hair cells have been damaged or destroyed. The normal ear, however, also contains multiplicative noise sources that result from the quantal nature of synaptic transmission between the inner hair-cells and the cochlear nerve. These noise synaptic noise sources are also largely absent in the deafened ear. Given that previous studies suggest that additive noise can enhance information coding by sensory systems, we have investigated whether multiplicative noise also enhances coding in a model of electrical stimulation of the cochlear nerve by a cochlear implant. The model was based on leaky integrate-and-fire dynamics and modelled refractory and accommodation effects by a threshold dependency derived from the sodium-inactivation dynamics of the Frankenhauser-Huxley equations for myelinated nerves. We show that multiplicative noise leads to a fundamental change in the coding mechanism and can lead to a marked increase in the transmitted information compared with additive noise or a control condition with no noise. These results suggest that multiplicative noise in the normal aud itory system might have a functional role. Keywords: cochlear implant, stochastic resonance, multiplicative noise, information rate

We will describe keyed communication in quantum noise (KCQ) and how it can be used for either data encryption or key generation. Specifically, we will focus on the AlphaEta protocol for data encryption where the role of quantum noise will be discussed. Additionally, the potential of using classical noise to enhance security via deliberate signal randomization (DSR) will be investigated. We will also investigate the effect of unwanted impairments, such as nonlinearities in a wavelength-division-multiplexed fiber transmission system, and how they affect the ultimate allowable propagation distance. Our simulations and experiments suggest that AlphaEta-protocol based physical-layer encryption is compatible with long-haul optical transmission systems operating at Gb/s data rates.

We consider the following general problem of applied stochastic nonlinear dynamics. We observe a time series of signals y(t) = y(t0+hn) corrupted by noise. The actual state and the nonlinear vector field of the dynamical system is not known. The question is how and with what accuracy can we determine x(t) and functional form of f(x). In this talk we discuss a novel approach to the solution of this problem based on the application of the path-integral approach to the full Bayesian inference. We demonstrate a reconstruction of a dynamical state of a system from corrupted by noise measurements. Next we reconstruct the corresponding nonlinear vector field. The emphasis are on the theoretical analysis. The results are compared with the results of earlier research.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.