Presence Of Noise Sources Research Articles

Assessment of Neonatal Intensive Care Unit Sound Exposure Using a Smartphone Application.

This study aimed to determine the impact of neonatal intensive care unit (NICU) design and environmental factors on neonatal sound exposures. We hypothesized that monitoring with a smartphone application would identify modifiable environmental factors in different NICU design formats. Minimum, maximum, and peak decibel (dB) recordings were obtained using the Decibel X phone app, and the presence of noise sources was recorded in each patient space at three NICUs over a 6-month period (December 2017 to May 2018). Data were analyzed by Student's t-test and ANOVA with Bonferroni correction. Data were collected at the University of Maryland Medical Center single family room (SFR) level IV and St. Agnes Healthcare hybrid pod/single family room level III NICU, Baltimore, MD and at Prince George's Hospital Center open-pod design Level III NICU, Cheverly, MD. All recordings in the three NICUs exceeded the American Academy of Pediatrics (AAP) recommended <45 dB level. The maximum and peak dB were highest in the open pod format level III NICU. Conversations/music alone and combined with other factors contributed to increased sound exposure. Sound exposure varied by day/night shift, with higher day exposures at the level III hybrid and open pod NICUs and higher night exposures at the level IV SFR NICU. Although sound exposure varied by NICU design, all recordings exceeded the AAP recommendation due, in part, to potentially modifiable environmental factors. A smartphone application may be useful for auditing NICU sound exposure in quality improvements efforts to minimize environmental sound exposure. · Smartphone application was used to assess NICU sound exposure.. · All cases of sound exposure exceed recommendations.. · A smartphone application was used to identify modifiable factors..

Circular Gate Tunnel FET: Optimization and Noise Analysis

This paper proposes a Silicon Tunnel Field Effect Transistor (TFET) with circular gate, and optimizes the structure for better performance. Two steps of performance optimization are adopted: reduction in ambipolar current and increase in on-off current ratio. The former objective is accomplished through introduction of gate-drain underlap, and the latter through gate-source overlap. The components of gate capacitance are analyzed and reported for the optimized structure. Furthermore, the behavior of the optimized device is observed in presence of noise sources and interface traps at two frequencies: 1MHz and 10GHz. Three noise sources, namely, Flicker Noise, Diffusion Noise and Generation-Recombination Noise are considered along with Gaussian traps of maximum concentration 1014 eV-1 cm-2.

Optimised diffusion spots’ locations for simultaneous improvement in SNR and delay spread

In this paper, two recent global optimisation techniques: particle swarm optimisation and central force optimisation are considered for optimising the location of the diffusion spots, which are used as transmitters in an indoor optical wireless communications system. The diffusion spots are uniformly distributed along a circle on the ceiling of the communications environment. The location of the diffusion spots is optimised for maximising the signal-to-noise ratio and minimising the root-mean-square delay spread at the receivers in the presence of noise sources. A performance comparison between the central located position of the spots and the optimised positions for three different scenarios is considered to validate and show the strengths of the applied optimisation techniques in solving this sort of problems. The used techniques can provide the communication system with the ability to adapt to changes in the surrounding environment, which will benefit future switching towards real-time intelligent systems.

Noise- and stimulus-dependence of the optimal encoding nonlinearities in a simple ON/OFF retinal circuit model

Encoding of stimuli in the retina depends on the statistical properties of the input stimuli, neural noise, and circuit nonlinearities. Here, we present a simple model of a two-path ON/OFF RGC circuit (figure ​(figure1A).1A). We use variational methods to analytically calculate the optimal encoding nonlinearities in the presence of noise sources with two key biophysical properties: they have separate components that corrupt the stimulus (pre-nonlinearity) and the responses (post-nonlinearity), and they may be correlated across cells. We study qualitatively the effects of the competition between the stimulus and noise sources on the form of the encoding nonlinearities. We find that when both pre- and post-nonlinearity noises are low, the ON and OFF pathways each encode roughly half of the stimulus distribution (figure ​(figure1B).1B). However, the optimal nonlinearities rearrange at higher noise levels, introducing redundancy in signal encoding (figure ​(figure1C).1C). For very large post-nonlinearity noise, the best the circuit can do is encode the sign of the received stimulus (figure ​(figure1D).1D). The results of related studies are consistent with behavior observed in specific parameter regimes of the broad framework encompassed by this model [1,2]. Figure 1 A. Simple two-pathway retinal circuit model. A stimulus (s) is presented and transmitted to separate ON and OFF pathways, which receive correlated corrupting noises η+ and η-, respectively. The signals are passed through encoding nonlinearities ...

Modelling Bacterial Dynamics in Food Products: Role of Environmental Noise and Interspecific Competition

In this paper we review some results obtained within the context of the predictive microbiology, which is a specific field of the population dynamics. In particular we discuss three models, which exploit tools of statistical mechanics, for bacterial dynamics in food of animal origin. In the first model, the random fluctuating behaviour, experimentally measured, of the temperature is considered. In the second model stochastic differential equations are introduced to take into account the influence of physical and chemical variables, such as temperature, pH and activity water, subject to deterministic and random variations. The third model, which is an extended version of the second one, neglects the environmental fluctuations, and concentrates on the role of the interspecific bacterial interactions. The comparison between expected results and observed data indicates that the presence of noise sources and interspecific bacterial interactions improves the predictive features of the models analyzed.

Entanglement Distillation by Dissipation and Continuous Quantum Repeaters

Even though entanglement is very vulnerable to interactions with the environment, it can be created by purely dissipative processes. Yet, the attainable degree of entanglement is profoundly limited in the presence of noise sources. We show that distillation can also be realized dissipatively, such that a highly entangled steady state is obtained. The schemes put forward here display counterintuitive phenomena, such as improved performance if noise is added to the system. We also show how dissipative distillation can be employed in a continuous quantum repeater architecture, in which the resources scale polynomially with the distance.

Breathing Detection: Towards a Miniaturized, Wearable, Battery-Operated Monitoring System

This paper analyzes the main challenges associated with noninvasive, continuous, wearable, and long-term breathing monitoring. The characteristics of an acoustic breathing signal from a miniature sensor are studied in the presence of sources of noise and interference artifacts that affect the signal. Based on these results, an algorithm has been devised to detect breathing. It is possible to implement the algorithm on a single integrated circuit, making it suitable for a miniature sensor device. The algorithm is tested in the presence of noise sources on five subjects and shows an average success rate of 91.3% (combined true positives and true negatives).