25,244 results
Search Results
2. The Quantum Illumination Story : (Invited Paper)
- Author
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Jeffrey H. Shapiro
- Subjects
Superposition principle ,Noise ,law ,Computer science ,Quantum radar ,Quantum illumination ,Quantum Physics ,Statistical physics ,Quantum entanglement ,Radar ,Classical physics ,Quantum ,law.invention - Abstract
Superposition and entanglement, the quintessential characteristics of quantum physics, have been shown to provide communication, computation, and sensing capabilities that go beyond what classical physics will permit. It is natural, therefore, to explore their application to radar, despite the fact that decoherence—caused by the loss and noise encountered in radar sensing—destroys these fragile quantum properties. This paper tells the story of “quantum illumination”, an entanglement-based approach to quantum radar, from its inception to its current understanding. Remarkably, despite loss and noise that destroys its initial entanglement, quantum illumination does offer a target-detection performance improvement over a classical radar of the same transmitted energy. A realistic assessment of that improvement’s utility, however, shows that its value is severely limited. Nevertheless, the fact that entanglement can be of value on an entanglement-breaking channel—the meta-lesson of the quantum illumination story—should spur continued research on quantum radar.
- Published
- 2019
3. POSITION PAPER: Countering the Noise-Induced Critical Path Problem
- Author
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Rogelio Long and Shirley Moore
- Subjects
Noise ,Noise induced ,Computer science ,Distributed computing ,Electronic engineering ,Position paper ,Critical path method ,Power (physics) - Abstract
As the number of cores grow in HPC systems, so does the effect of system noise on applications running on these systems. With the knowledge that future large-scale parallel computer systems, including exascale systems, will operate under an overall power bound, we claim to have found a solution that can counter the effects of noise. We present two methods that estimate the effects of noise on an application and then optimally redistributes power among nodes, such that the effects of noise are "hidden".
- Published
- 2016
4. [Regular Paper] Stochastic Non-minimal State Space Control with Application to Automated Drug Delivery
- Author
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C. James Taylor, Quentin Clairon, and Emma Wilson
- Subjects
Stochastic control ,0209 industrial biotechnology ,State variable ,Computer science ,0211 other engineering and technologies ,State vector ,02 engineering and technology ,Kalman filter ,Noise ,020901 industrial engineering & automation ,Control theory ,Control system ,021105 building & construction ,State space - Abstract
This paper shows how a standard proportional-integral-plus controller, based on a non-minimal state space (NMSS) design, can be extended to reduce the effects of measurement noise and so yield smoother control inputs for automated drug delivery control applications. Use of a NMSS model for state variable feedback control design, in which all the states are based on the directly measured input and output variables, removes the need for state estimation. Nonetheless, a stochastic NMSS form, with a Kalman filter, can optionally be introduced to reduce the effect of measurement noise and so yield smoother control inputs. In this case, the Kalman filter attenuates measurement noise but does not address state disturbances. In this article, we propose a modification to the stochastic NMSS control system to enable the elimination of such state disturbances. This involves further extending the non–minimal state vector to include additional terms based on the innovations. We compare the deterministic, stochastic and extended stochastic NMSS controllers via a simulation of the control of anaesthesia using propofol.
- Published
- 2018
5. Meeting the Conflicting Goals of Low-Power and Resiliency Using Emerging Memories : (Invited Paper)
- Author
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Karthikeyan Nagarajan, Sina Sayyah Ensan, Swaroop Ghosh, Mohammad Nasim Imtiaz Khan, and Abdullah Ash-Saki
- Subjects
010302 applied physics ,Hardware_MEMORYSTRUCTURES ,Computer science ,media_common.quotation_subject ,02 engineering and technology ,Leakage power ,01 natural sciences ,020202 computer hardware & architecture ,Power (physics) ,Reliability engineering ,Footprint ,Noise ,CMOS ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Psychological resilience ,media_common - Abstract
Emerging non-volatile memory (NVM) technologies are being aggressively explored to replace and/or assist conventional CMOS technology. Although NVMs can cut down leakage power, achieve low footprint and allow compute capability along with storage, they suffer from new sources of variability. We review the noise sources associated with NVMs and describe resilience enhancement techniques for both memory and computing. We also present security applications where noise and variability is desirable.
- Published
- 2019
6. Multiple input multiple output Dirty paper coding: System design and performance
- Author
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Dinesh Rajan and Zouhair Al-qudah
- Subjects
Space–time block code ,Noise ,Convolutional code ,Electronic engineering ,Dirty paper coding ,Data_CODINGANDINFORMATIONTHEORY ,Low-density parity-check code ,Antenna diversity ,Algorithm ,Decoding methods ,Coding gain ,Computer Science::Information Theory ,Mathematics - Abstract
In this paper, a practical multiple input multiple output Dirty paper coding (MIMO-DPC) scheme is designed to cancel the effect of additive interference that is known perfectly to the transmitter. The proposed system uses a trio of encoders — a LDPC code, a vector quantizer implemented as a convolutional decoder and an Orthogonal space time block code (STBC) to achieve temporal coding gain, interference cancelation and spatial diversity, respectively. First, we derive the equivalent noise seen by the receiver using an equivalent lattice based dirty paper code. Then the optimal value of the power inflation factor, which is one of the key system parameters used to minimize the equivalent noise seen by the receiver is derived. Furthermore, we analytically prove that the equivalent noise seen by the receiver tends to 0 for large number of receive antennas. Performance results in the case of various number of receiver antennas are presented and show that significant reduction in bit error probabilities can be obtained over a system that uses no interference cancelation.
- Published
- 2012
7. Carbon Copying Onto Dirty Paper.
- Author
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Khisti, Ashish, Erez, Uri, Lapidoth, Amos, and Wornell, Gregory W.
- Subjects
- *
WIRELESS communications , *MULTICASTING (Computer networks) , *NOISE , *ANTENNAS (Electronics) , *GAUSSIAN processes , *NUMERICAL analysis , *MATHEMATICAL analysis , *ELECTRICAL engineering - Abstract
A generalization of the problem of writing on dirty paper is considered in which one transmitter sends a common message to multiple receivers. Each receiver experiences on its link an additive interference (in addition to the additive noise), which is known noncausally to the transmitter but not to any of the receivers. Applications range from wireless multiple-antenna multicasting to robust dirty paper coding. We develop results for memoryless channels in Gaussian and binary special cases. In most cases, we observe that the availability of side information at the transmitter increases capacity relative to systems without such side information, and that the lack of side information at the receivers decreases capacity relative to systems with such side information. For the noiseless binary case, we establish the capacity when there are two receivers. When there are many receivers, we show that the transmitter side information provides a vanishingly small benefit. When the interference is large and independent across the users, we show that time sharing is optimal. For the Gaussian case, we present a coding scheme and establish its optimality in the high signal-to-interference-plus-noise limit when there are two receivers. When the interference power is large and independent across all the receivers, we show that time-sharing is again optimal. Connections to the problem of robust dirty paper coding are also discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
8. On the application of neural networks modelling to a wet end chemical process in paper making
- Author
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B. Oyebande and Hong Wang
- Subjects
Recursive least squares filter ,Engineering ,business.product_category ,Artificial neural network ,Time delay neural network ,business.industry ,Process (computing) ,Control engineering ,Sizing ,Noise ,Paper machine ,Knot (unit) ,business ,Algorithm - Abstract
This paper presents a novel approach and its application to the modelling of non-linear unknown systems via B-spline neural networks. The system is assumed to be described by a NARMAX model, which is subjected to coloured noise. A new regression formula is constructed and it has been shown that the generalised RLS algorithm can be directly applied to train the weights and produce a desirable estimate on the various modes of the noise. The selection of the knots distribution of B-spline neural networks is also considered. An algorithm has been developed which produces an optimal knot distribution for an input axis using training data. Finally, the method developed is applied to build up a local model for a paper machine wet end, which represents the relationship between added chemicals (rosin and alum) and the sizing of the resulting paper. Desired results are obtained.
- Published
- 2002
9. A paper clock prediction model for UTC(TL)
- Author
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Shinn-Yan Lin
- Subjects
business.industry ,020208 electrical & electronic engineering ,Mathematical analysis ,Frequency drift ,02 engineering and technology ,White noise ,01 natural sciences ,Exponential function ,Weighting ,010309 optics ,Noise ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Physics::Atomic Physics ,Allan variance ,Telecommunications ,business ,Frequency modulation ,Caesium standard ,Mathematics - Abstract
A modified paper clock timescale weighted after removing the linearized frequency drift of each cesium clock in TL's 12-cesium-clock ensemble is used to be the mid-term prediction reference before the next coming BIPM Circular T announcement. After removing the frequency drift pattern according to Circular T announcements, the noise type of each cesium clock in ensemble is dominated by white noise when the average time was less than about 100 days. To achieve approximately equal weighting and rational upper limit, an inversely exponential weighting procedure is also used to weight each cesium clock according to the inversely exponential function of their Allan variance; for our 12-cesium-clock ensemble, a 4 years test shows the phase error of the paper clock time scale is less than 10 ns in 45 days prediction.
- Published
- 2016
10. Entropy Amplification Property and the Loss for Writing on Dirty Paper.
- Author
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Cohen, Aaron S. and Zamir, Ram
- Subjects
- *
ENTROPY , *NOISE , *DISTRIBUTION (Probability theory) , *PROBABILITY theory , *RISK , *DIFFERENCE sets - Abstract
Costa's celebrated "writing on dirty paper" (WDP) shows that the power-constrained channel Y = X + S + Z, with Gaussian Z, has the same capacity as the standard AWGN channel Y = X + Z, provided that the "interference" S (no matter how strong it is) is known at the transmitter. While this ability for perfect interference cancelation is very appealing, it relies heavily on the Gaussianity of the (unknown) noise Z. We construct an example of "bad" noise for writing on dirty paper, namely, "difference set noise". If the interference S is strong, then difference-set noise limits the WDP capacity to at most 2 bits. At the same time, like in the AWGN case, the zero-interference capacity grows without bound with the input constraint. Thus almost 100% of the available capacity is lost in WDP in the presence of difference-set noise. This high capacity loss is due to the "entropy amplification property" (EAP) of noise with an aperiodic probability distribution. Using the EAP and the duality between WDP and Wyner--Ziv source coding, we also give an example of dramatic rate-loss in quantizing encrypted source. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
11. Dirty-Paper Coding Versus TDMA for MIMO Broadcast Channels.
- Author
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Jindal, Nihar and Goldsmith, Andrea
- Subjects
- *
COMPARISON (Philosophy) , *BROADCASTING industry , *NOISE , *INVESTIGATIONS , *INFORMATION theory , *DIGITAL electronics - Abstract
We compare the capacity of dirty-paper coding (DPC) to that of time-division multiple access (TDMA) for a multiple-antenna (multiple- input multiple-output (MIMO)) Gaussian broadcast channel (BC). We find that the sum-rate capacity (achievable using DPC) of the multiple-antenna BC Is at most min(M, K) times the largest single-user capacity (i.e., the TDMA sum-rate) in the system, where M is the number of transmit antennas and K is the number of receivers. This result is Independent of the number of receive antennas and the channel gain matrix, and is valid at all signal-to-noise ratios (SNRs). We investigate the tightness of this bound In a time-varying channel (assuming perfect channel knowledge at receivers and transmitters) where the channel experiences uncorrelated Rayleigh fading and In some situations we find that the dirty paper gain is upper-bounded by the ratio of transmit-to-receive antennas. We also show that min(M, K) upper-bounds the sum-rate gain of successive decoding over TDMA for the uplink channel, where M is the number of receive antennas at the base station and K is the number of transmitters. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
12. Dirty-Paper Coding for the Gaussian Multiaccess Channel With Conferencing.
- Author
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Bross, Shraga I., Lapidoth, Amos, and Wigger, Michèle
- Subjects
- *
GAUSSIAN processes , *TRANSMITTERS (Communication) , *RANDOM noise theory , *CODE division multiple access , *CODING theory , *SIGNAL processing , *BIT error rate - Abstract
We derive the capacity region of the two-user dirty-paper Gaussian multiaccess channel (MAC) with conferencing encoders. In this MAC, prior to each transmission block, the transmitters can hold a conference in which they can communicate with each other over error-free bit pipes of given capacities. The received signal suffers not only from additive Gaussian noise but also from additive interference, which is known noncausally to the transmitters but not to the receiver. The additive interference is modeled as Gaussian or uniform over a sphere. We show that the interference can be perfectly mitigated, i.e., that the capacity region without interference can also be achieved in its presence. This holds irrespective of whether the transmitters learn the interference before or after the conference. It follows as a corollary that also for the MAC with degraded message sets, the interference can be perfectly mitigated if it is known noncausally to the transmitters. To derive our results, we generalize Costa's single-user writing-on-dirty-paper achievability result to channels with dependent interference and not-necessarily Gaussian noise. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
13. Application of cluster validity criteria to Rock-Paper-Scissors game judgment.
- Author
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Matsumoto, Yui, Yamamoto, Takeshi, Honda, Katsuhiro, Notsu, Akira, and Ichihashi, Hidetomo
- Abstract
This paper considers an application of cluster validity indexes to automated judgment in Rock-Paper-Scissors (RPS) game. In the task, the number and the locations of hands in RPS pictures are first estimated by c-Means-type clustering in conjunction with cluster validity measures. Then, the judgment of winner/loser is performed considering the difference among compactness of clusters. After preprocessing of extracting hand region coordinates from RPS pictures, Hard c-Means (HCM) and Fuzzy c-Means (FCM) is applied in conjunction with cluster validity measures for searching for the optimal number and locations of hands, and the applicability of noise rejection is compared in several experiments. The compactness of clusters is also measured by the same concept used in cluster validity measures. The experimental results imply that FCM with noise rejection used with cluster validity measures works better in RPS game judgment without following complex image processing. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
14. 25nm 64Gb MLC NAND technology and scaling challenges invited paper
- Author
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Krishna K. Parat and Kirk D. Prall
- Subjects
Noise ,Hardware_MEMORYSTRUCTURES ,Logic synthesis ,Hardware_GENERAL ,business.industry ,Computer science ,Logic gate ,Electrical engineering ,Electronic engineering ,NAND gate ,business ,Capacitance ,Scaling - Abstract
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.
- Published
- 2010
15. Automated identification of web shrinkage and alignment in paper and film machines
- Author
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C. Hagart-Alexander, D. Gorinevsky, M. Heaven, and C. Lynch
- Subjects
Noise ,Identification (information) ,Computer science ,Algorithm design ,Interval (mathematics) ,Algorithm ,Noise shaping ,Simulation ,Shrinkage - Abstract
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.
- Published
- 2002
16. On the Estimation of State Variables and Parameters for Noisy Dynamic SystemsReceived November 7, 1963. The work described in this paper is based on a dissertation submitted in partial fulfillment of the requirements for the Sc.D. degree in the Department of Electrical Engineering, Massachusetts Institute of Technology, Cambridge
- Author
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Harry L. Van Trees and Kristine L. Bell
- Subjects
Estimation ,Dynamic programming ,Nonlinear system ,Work (thermodynamics) ,Mathematical optimization ,Engineering ,State variable ,Noise ,Degree (graph theory) ,Operations research ,business.industry ,Linear problem ,business - Abstract
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.
- Published
- 2009
17. Han–Kobayashi and Dirty-Paper Coding for Superchannel Optical Communications.
- Author
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Koike-Akino, Toshiaki, Kojima, Keisuke, Millar, David S., Parsons, Kieran, Kametani, Soichiro, Sugihara, Takashi, Yoshida, Tsuyoshi, Ishida, Kazuyuki, Miyata, Yoshikuni, Matsumoto, Wataru, and Mizuochi, Takashi
- Abstract
Superchannel transmission is a candidate to realize Tb/s-class high-speed optical communications. In order to achieve higher spectrum efficiency, the channel spacing shall be as narrow as possible. However, densely allocated channels can cause non-negligible inter-channel interference (ICI) especially when the channel spacing is close to or below the Nyquist bandwidth. In this paper, we consider joint decoding to cancel the ICI in dense superchannel transmission. To further improve the spectrum efficiency, we propose the use of Han–Kobayashi superposition coding. In addition, for the case when neighboring subchannel transmitters can share data, we introduce dirty-paper coding for pre-cancelation of the ICI. We analytically evaluate the potential gains of these methods when ICI is present for sub-Nyquist channel spacing. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
18. Silent dryer drive concept for paper machines
- Author
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J.G. Miller
- Subjects
Noise ,Engineering ,Acceleration ,business.industry ,Noise reduction ,Airflow ,Lubrication ,Electrical engineering ,business ,Automotive engineering ,Backlash - Abstract
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. >
- Published
- 2003
19. On-line estimation of a dynamic model for basis weight variations in paper machines
- Author
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X.G. Wang, Guy A. Dumont, and M.S. Davies
- Subjects
Estimation ,Noise ,Extended Kalman filter ,Basis (linear algebra) ,Computer science ,Control theory ,Stochastic process ,Line (geometry) ,Process (computing) ,Kalman filter - Abstract
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. >
- Published
- 2003
20. Adaptive basis weight control in paper machines
- Author
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X.G. Wang, Guy A. Dumont, and M.S. Davies
- Subjects
Noise ,Model predictive control ,Adaptive control ,Basis (linear algebra) ,Computer science ,Control theory ,Process (computing) ,Weight control - Abstract
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. >
- Published
- 2002
21. Computation Alignment: Capacity Approximation Without Noise Accumulation.
- Author
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Niesen, Urs, Nazer, Bobak, and Whiting, Phil
- Subjects
- *
WIRELESS communications , *PAPER arts , *MATHEMATICS , *STATISTICS , *NOISE - Abstract
Consider several source nodes communicating across a wireless network to a destination node with the help of several layers of relay nodes. Recent work by Avestimehr has approximated the capacity of this network up to an additive gap. The communication scheme achieving this capacity approximation is based on compress-and-forward, resulting in noise accumulation as the messages traverse the network. As a consequence, the approximation gap increases linearly with the network depth. This paper develops a computation alignment strategy that can approach the capacity of a class of layered, time-varying wireless relay networks up to an approximation gap that is independent of the network depth. This strategy is based on the compute-and-forward framework, which enables relays to decode deterministic functions of the transmitted messages. Alone, compute-and-forward is insufficient to approach the capacity as it incurs a penalty for approximating the wireless channel with complex-valued coefficients by a channel with integer coefficients. Here, this penalty is circumvented by carefully matching channel realizations across time slots to create integer-valued effective channels that are well suited to compute-and-forward. Unlike prior constant gap results, the approximation gap obtained in this paper also depends closely on the fading statistics, which are assumed to be i.i.d. Rayleigh. [ABSTRACT FROM PUBLISHER]
- Published
- 2013
- Full Text
- View/download PDF
22. A Hands-Free Unit with Noise Reduction by Using Adaptive Beamformer.
- Author
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Kobayashi, Kazunori, Haneda, Yoichi, Furuya, Ken'ichi, and Kataoka, Akitoshi
- Subjects
- *
NOISE , *PAPER , *NUMERICAL analysis , *COMPUTER simulation , *SIMULATION methods & models , *ELECTROMECHANICAL analogies , *COMPUTERS , *MATHEMATICAL models , *SOUND - Abstract
This paper presents an implementation of an ~daptive beamformer in a hands-free unit. The proposec~ ~daptive beamformer suppresses stationary noise an~ nterference sound. The adaptive beamformer and acoustic `cho canceller were implemented in a compact hands-free mit with a low-cost DSP. Experimental results demonstrate he noise reduction performance of the hands-free unit'. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
23. Approximate Sparsity Pattern Recovery: Information-Theoretic Lower Bounds.
- Author
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Reeves, Galen and Gastpar, Michael C.
- Subjects
- *
ERRORS , *PAPER arts , *NOISE , *REMOTE sensing , *INFORMATION theory - Abstract
Recovery of the sparsity pattern (or support) of an unknown sparse vector from a small number of noisy linear measurements is an important problem in compressed sensing. In this paper, the high-dimensional setting is considered. It is shown that if the measurement rate and per-sample signal-to-noise ratio (SNR) are finite constants independent of the length of the vector, then the optimal sparsity pattern estimate will have a constant fraction of errors. Lower bounds on the measurement rate needed to attain a desired fraction of errors are given in terms of the SNR and various key parameters of the unknown vector. The tightness of the bounds in a scaling sense, as a function of the SNR and the fraction of errors, is established by comparison with existing achievable bounds. Near optimality is shown for a wide variety of practically motivated signal models. [ABSTRACT FROM PUBLISHER]
- Published
- 2013
- Full Text
- View/download PDF
24. Precision Metrology at the University of Western Australia invited paper.
- Author
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Tobar, Michael E., Ivanov, Eugene N., Creedon, Daniel L., le Floch, Jean-Michel, Benmessai, Karim, Fan, Yaohui, Farr, Warrick, Reshitnyk, Yarema, Duty, Timothy L., and Martinis, John M.
- Abstract
The Frequency Standards and Metrology Research Group at the University of Western Australia have been developing some of the world's most ultra-precise measurements at microwave frequencies since the 1990s. This paper reviews past and intended future work with applications to low temperatures where quantum effects become important. [ABSTRACT FROM PUBLISHER]
- Published
- 2011
25. Variance-Minimization Iterative Matching Method for Free-Form Surfaces—Part II: Experiment and Analysis.
- Author
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Xie, He, Li, Wen-long, Yin, Zhou-Ping, and Ding, Han
- Subjects
SPARE parts ,RANDOM noise theory ,MANUFACTURING processes ,NOISE ,MAGNETIC flux leakage ,AREA measurement ,MACHINING - Abstract
In the first part of this paper, a free-form surface matching method called variance-minimization matching (VMM) was proposed to address uneven/open point distributions and measuring noise. The convergence property and sensitivity to measuring defects were theoretically studied. In the second part of this paper, a series of experiments are presented to verify the feasibility of the proposed method in free-form surface matching. The experiments are divided into four sets: a measuring defects experiment, a noise experiment, a convergence experiment, and an artificial experiment. In the first set of experiments, the existing methods are prone to becoming trapped in a local optimum affected by uneven/open point distributions, which shows that measured points incline toward dense areas. However, in VMM, there is little inclination regardless of the increase in the number of measuring defects. In the second set of experiments, sensitivity to varying noise is tested. The results show that VMM helps prevent unstable sliding in the presence of Gaussian noise. In the third set of experiments, we compare convergence speed and convergence stability under different initial positions. It is verified that VMM exhibits the quadratic convergence. Finally, a set of artificial experiments is implemented, revealing that the proposed method is appropriate for use in automated manufacturing processes such as geometric inspection and allowance distribution. Note to Practitioners—Measuring defects usually occur when using a scanning device to obtain the measured points of a workpiece. Weakening the effect of measuring defects on matching results is critical to promoting manufacturing automation. This paper proposes a new method called variance-minimization matching (VMM) that considers measuring defects. In the first part of this paper, the modeling and theoretical analysis of VMM were introduced. In the second part of this paper, simulated experiments are performed to verify the feasibility of VMM in addressing uneven/open point distributions, measuring noise, and large initial positions. Next, artificial experiments employing VMM in geometric inspection and allowance distribution are presented. The proposed method also applies to other automated manufacturing processes, such as workpiece localization, deformation analysis, and complex parts repair. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
26. Performance Impacts of Analog ReRAM Non-ideality on Neuromorphic Computing.
- Author
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Lin, Yu-Hsuan, Wang, Chao-Hung, Lee, Ming-Hsiu, Lee, Dai-Ying, Lin, Yu-Yu, Lee, Feng-Min, Lung, Hsiang-Lan, Wang, Keh-Chung, Tseng, Tseung-Yuen, and Lu, Chih-Yuan
- Subjects
NONVOLATILE random-access memory ,ARTIFICIAL neural networks ,ELECTRIC admittance ,ELECTRIC resistance ,NONVOLATILE memory - Abstract
Resistive random access memory (ReRAM) is often considered as a strong candidate for storing the weights in non-von Neumann neuromorphic computing systems. This paper studies how nonideal memory characteristics, which include programing error, read fluctuation, and retention, affect the inference accuracy of the analog ReRAM neural networks by incorporating memory characteristics extracted from 1-Mb ReRAM into a simulated inference-only neural network. This paper also shows that the different layer in the network can tolerate different amount of such imperfects. We learned four key points: 1) the conductance range of memory with less relative fluctuation is preferred for designing the weight-conductance mapping; 2) the control of programing error is essential for high inference accuracy; 3) retention-induced conductance drift can be fatal to the neuromorphic system. A compensation scheme is proposed in this paper which can effectively recover the inference accuracy; and 4) for multilayer networks, avoiding weight errors in the front layers can help to maintain the inference accuracy by reducing calculation error which may otherwise accumulate and pass down the networks. The concepts and approaches of this paper can also be applied to evaluate other types of nonvolatile memories for artificial neural networks. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
27. Novel Solution to Back Flashovers on High Voltage Transmission Lines: The Embedded Ground Conductor.
- Author
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Rizk, Farouk A. M.
- Subjects
ELECTRIC lines ,FLASHOVER ,LIGHTNING ,DIELECTRICS ,NOISE - Abstract
It is well known that for high voltage transmission lines in the range of 245 kV–525 kV, particularly in regions of high ground resistivity, lightning back flashover problems could be a major concern. Line arresters have been used successfully to address the problem. Underbuilt ground wires have been proposed as a viable alternative. The present paper shows that the full potential of additional ground wires could be achieved by optimizing their position on the tower. Such optimization often results in a preferred position at the level, or higher than the attachment height of the lower phase conductors; therefore the designation Embedded Ground Conductor. An essential requirement is that such positioning does not infringe in any way on the dielectric integrity of the electrical clearances and, under the influence of induced charge, does not become a source of positive streamers that may lead to additional radio or audible noise. It is found that a streamer- inhibited conductor, when properly placed, fully satisfies the above requirements. It is determined that for 245 kV, 345 kV and 420 kV lines, a streamer-inhibited embedded conductor could improve the back flashover rate by a factor of 10 or more [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
28. Noise Adaptation Generative Adversarial Network for Medical Image Analysis.
- Author
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Zhang, Tianyang, Cheng, Jun, Fu, Huazhu, Gu, Zaiwang, Xiao, Yuting, Zhou, Kang, Gao, Shenghua, Zheng, Rui, and Liu, Jiang
- Subjects
IMAGE analysis ,DIAGNOSTIC imaging ,OPTICAL coherence tomography ,NOISE ,PHYSIOLOGICAL adaptation - Abstract
Machine learning has been widely used in medical image analysis under an assumption that the training and test data are under the same feature distributions. However, medical images from difference devices or the same device with different parameter settings are often contaminated with different amount and types of noises, which violate the above assumption. Therefore, the models trained using data from one device or setting often fail to work for that from another. Moreover, it is very expensive and tedious to label data and re-train models for all different devices or settings. To overcome this noise adaptation issue, it is necessary to leverage on the models trained with data from one device or setting for new data. In this paper, we reformulate this noise adaptation task as an image-to-image translation task such that the noise patterns from the test data are modified to be similar to those from the training data while the contents of the data are unchanged. In this paper, we propose a novel Noise Adaptation Generative Adversarial Network (NAGAN), which contains a generator and two discriminators. The generator aims to map the data from source domain to target domain. Among the two discriminators, one discriminator enforces the generated images to have the same noise patterns as those from the target domain, and the second discriminator enforces the content to be preserved in the generated images. We apply the proposed NAGAN on both optical coherence tomography (OCT) images and ultrasound images. Results show that the method is able to translate the noise style. In addition, we also evaluate our proposed method with segmentation task in OCT and classification task in ultrasound. The experimental results show that the proposed NAGAN improves the analysis outcome. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
29. Factors affecting polarization and depolarization current measurements on insulation of transformers.
- Author
-
Flora, S. Daisy, Divekar, Mohan S., and Rajan, J. Sundara
- Subjects
POLARIZATION (Electricity) ,TRANSFORMER insulation ,ELECTRIC current measurement ,ELECTRIC resistors ,ELECTRIC noise - Abstract
Polarization and depolarization current measurements are promising on-site, off-line, non-destructive, non-invasive diagnostic tool for condition assessment of paper-oil insulation of transformers. Interpretation of the results of polarization and depolarization current is complex and hence not practiced as a routine diagnostic method for condition monitoring of transformers. This paper discusses various factors affecting polarization and depolarization current measurements with a deeper insight into the theoretical and practical aspects of this technique. Some of the concerns of PDC measurement are explained with support from simulation and experimental studies on paper oil insulation of a laboratory model transformer. Few case studies are discussed to highlight the difficulties in interpretation of results. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
30. Learning-Based Noise Component Map Estimation for Image Denoising.
- Author
-
Bahnemiri, Sheyda Ghanbaralizadeh, Ponomarenko, Mykola, and Egiazarian, Karen
- Subjects
IMAGE denoising ,ARTIFICIAL neural networks ,ADDITIVE white Gaussian noise ,CONVOLUTIONAL neural networks ,RANDOM noise theory ,NOISE - Abstract
A problem of image denoising, when images are corrupted by a non-stationary noise, is considered in this paper. Since, in practice, no a priori information on noise is available, noise statistics should be pre-estimated prior to image denoising. In this paper, deep convolutional neural network (CNN) based method for estimation of a map of local, patch-wise, standard deviations of noise (so-called sigma-map) is proposed. It achieves the state-of-the-art performance in accuracy of estimation of sigma-map for the case of non-stationary noise, as well as estimation of a noise variance for the case of an additive white Gaussian noise. Extensive experiments on image denoising using estimated sigma-maps demonstrate that our method outperforms recent CNN-based blind image denoising methods by up to 6 dB in PSNR, as well as other state-of-the-art methods based on sigma-map estimation by up to 0.5 dB, providing, at the same time, better usage flexibility. A comparison with the ideal case, when denoising is applied using ground-truth sigma-map, shows that a difference of corresponding PSNR values for the most of noise levels is within 0.1-0.2 dB, and does not exceed 0.6 dB. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
31. Subsampling Mismatch Noise Cancellation for High-Speed Continuous-Time DACs.
- Author
-
Kong, Derui and Galton, Ian
- Subjects
DIGITAL-to-analog converters ,TECHNOLOGY convergence ,FINITE impulse response filters ,NOISE - Abstract
Clock skew and component mismatches in continuous-time DACs introduce two types of error: static error and dynamic error. Both types of error typically limit the performance of practical, high-resolution, and continuous-time DACs, but most prior calibration techniques primarily reduce only static error. An exception is a recently published mismatch noise cancellation (MNC) technique that adaptively measures and cancels both types of error over the DAC’s first Nyquist band. However, a disadvantage of the technique is that it requires an oversampling ADC that operates at several times the DAC’s Nyquist rate to prevent convergence error that would otherwise be caused by aliasing. This paper presents a sub-sampling version of the MNC technique that avoids this limitation at the expense of a lower calibration convergence rate. As proven in the paper, the subsampling MNC technique allows aliasing to occur, but in such a way that convergence error is avoided. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
32. Sub-1-dB and Wideband SiGe BiCMOS Low-Noise Amplifiers for $X$ -Band Applications.
- Author
-
Chliskan, Can, Kalyoncu, Ilker, Yazici, Melik, and Gurbuz, Yasar
- Subjects
LOW noise amplifiers ,DIGITAL-to-analog converters ,KEY performance indicators (Management) ,BROADBAND amplifiers ,DESIGN techniques ,NOISE measurement - Abstract
In this paper, a design methodology for SiGe HBT-based low-noise amplifiers (LNAs) is proposed that can be utilized for both sub-1-dB noise figure (NF) and wide bandwidth as an alternative to the conventional simultaneous input noise and power matching technique. This paper focuses on the removal of the series base inductor and the inclusion of an output matching network as a design parameter that can be used to achieve both sub-1dB NF and wide bandwidth. The effects of the mentioned design parameters on NF and bandwidth are described and analyzed, including the comparison of results with the conventional design technique. To demonstrate the validity of the analysis and impact of utilizing base-to-collector capacitance on LNA performance metrics, two different LNAs implemented in a 0.13- $\mu \text{m}$ SiGe technology. The first LNA achieves a lower than 1-dB NF with 26-dB gain at 8.5 GHz, and the second LNA exhibits wideband operation, with a better than 10-dB return losses in the range of 8–35 GHz and lower than 3-dB NF from 6 to 20 GHz. The sub-1-dB LNA reaches −17.3 dBm of input-referred compression point (IP1dB), with a power consumption of 62 mW and an area of 0.795 mm2. The wideband LNA achieves 17.6 dB of peak gain with a 48.5-mW power consumption and 0.69-mm2 chip area. To the best of our knowledge, this paper achieves the best NF performance in the literature utilizing a SiGe technology, while the wideband LNA exhibits the best operational bandwidth, together with a reasonable low-noise performance. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
33. A Family of ΔΣ Modulators With High Spur Immunity and Low Folded Nonlinearity Noise When Used in Fractional- Frequency Synthesizers.
- Author
-
Mazzaro, Valerio and Kennedy, Michael Peter
- Subjects
FREQUENCY synthesizers ,ELECTRONIC modulators ,PHASE-locked loops ,NOISE ,IMMUNITY - Abstract
Phase locked loops for fractional frequency synthesis typically use Digital $\Delta \Sigma $ Modulators (DDSMs) as their divider controllers. Different types and configurations of DDSMs have been presented in the past which have distinctive characteristics in terms of spectral shaping of their quantization errors, spur immunity and implementation costs. This paper presents a family of DDSMs that have provably high spur immunity and low folded noise when used in fractional- ${N}$ frequency synthesizers with polynomial nonlinearities. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
34. Noise Aware L₂-LP Decomposition-Based Enhancement in Extremely Low Light Conditions With Web Application.
- Author
-
Singh, Neha and Bhandari, Ashish Kumar
- Subjects
IMAGE denoising ,WEB-based user interfaces ,NOISE ,IMAGE color analysis ,HISTOGRAMS ,GAMMA functions - Abstract
In this article, an algorithm is introduced which not only focuses on enhancing low light images but also denoises images to produce more visually pleasing outputs. It is observed that various methods ignore noise during enhancement processes. This causes, enhancement of noise which leads to significant information lost. The paper projected a novel framework for low light images that performs enhancement and denoising jointly. The proposed paper uses $L_{2}$ - $L_{P}$ image decomposition to obtain reflectance and illumination concurrently. The illumination layer is corrected using the proposed weighting distribution and generates enhanced output. Further to this, noise suppressed bilateral filter is employed here for denoising process and gamma function is applied in subsequent step for additional contrast improvement. Experimental trials illustrate that the proposed method yields result with good contrast and brightness when it is compared to various enhancement techniques. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Artificial Noise Scheme for Correlated MISO Wiretap Channels.
- Author
-
Yun, Sangseok, Kim, Il-Min, and Ha, Jeongseok
- Subjects
WIRETAPPING ,NOISE ,TRANSMITTING antennas ,SECRECY - Abstract
This correspondence paper studies how correlation of the wiretap channel affects the secrecy rate of the artificial noise (AN) scheme. To this end, we first develop a simple but tight lower bound on the ergodic secrecy rate of the AN scheme on correlated multiple-input single-output wiretap channels. Then, utilizing the derived bound, we investigate the influence of correlation on the secrecy rate, which explicitly manifests how the channel correlation affects the optimal power allocation. Ultimately, this paper answers two fundamental questions: when is the AN signal beneficial? and how much power should be allocated for the AN signal to achieve a higher ergodic secrecy rate? in terms of channel correlation. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
36. Signal and Noise Performance of a 110-nm CMOS Technology for Photon Science Applications.
- Author
-
Traversi, Gianluca, Dinapoli, Roberto, Manghisoni, Massimo, Mozzanica, Aldo, and Riceputi, Elisa
- Subjects
NOISE ,COMPLEMENTARY metal oxide semiconductors ,ANALOG circuits ,SYNCHROTRONS ,FREE electron lasers - Abstract
This paper presents a study of the noise behavior of MOSFET devices belonging to a 110-nm CMOS technology in view of applications to the design of low-noise, low-power analog circuits in X-ray detection at free electron lasers (FELs) and the next generation of synchrotrons. The goal of this paper is to provide a valuable and cost-effective option, with respect to more scaled and expensive technology nodes, to designers of the detection systems of FELs and next-generation synchrotron sources. The white component of the noise voltage spectrum and the 1/ $f$ noise contribution is experimentally characterized by noise measurements in a wide frequency range. Data extracted from the characterization have been studied as a function of the bias condition and the gate dimensions (length and width). A comparison of the main parameters with less and more scaled CMOS generations is also provided. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
37. High-Frequency Noise Characterization and Modeling of SiGe HBTs.
- Author
-
Cheng, Peng and Shichijo, Hisashi
- Subjects
HETEROJUNCTION bipolar transistors ,NOISE ,AUDIO frequency ,SILICON ,GERMANIUM ,ADMITTANCE parameters (Electric networks) ,SCIENTIFIC models - Abstract
For heterojunction bipolar transistors (HBTs), the noise correlation influences the noise parameters and is therefore relevant for transistor modeling, especially at sufficiently high frequencies. In order to predict the noise correlation, it is necessary to determine the noise transit time in the noise transport model. In this paper, the noise correlation and noise transit time are predicted from the high current model without measured noise data. The four noise parameters are calculated based on the predicted noise transit time and the Y-parameter noise calculation methodology. The extracted noise transit time is validated by the measured result over bias and temperature, which is determined by fitting NFmin of the silicon-germanium (SiGe) HBT between Y-parameter noise calculation methodology and tuner-based noise measurement. It was found that the noise transit time is independent of frequency but dependent on bias and temperature. Also, the results indicate that the calculated four noise parameters based on the extracted noise transit time have a good agreement with the tuner-based noise measurement. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
38. Mass Tuning Reduction Method for Vibration and Audible Noise of HVDC Filter Capacitors.
- Author
-
Zhu, Lingyu, Gao, Lu, Li, Jinyu, Jiang, Zhitong, Yang, Hang, and Ji, Shengchang
- Subjects
CAPACITORS ,NOISE control ,FREQUENCIES of oscillating systems ,CONTINUUM mechanics ,NOISE - Abstract
Filter capacitors are among the most serious noise sources in HVDC converter stations, and there are still no satisfactory noise reduction measures. This paper proposes the use of the mass tuning (MT) method to adjust the vibration frequency response characteristics and to realize vibration control and noise reduction. First, the theoretical model of the MT structure is developed based on continuum mechanics. Based on the theoretical model, it is revealed that inserting an MT component into the capacitor element package will cause a decrease in the resonant frequencies and antiresonant frequencies. Furthermore, the movement degree of the resonant frequencies increases as the position of the MT component becomes closer to the package end, while the movement degree of the antiresonant frequency is the largest when the MT component is located in the middle of the package model. The vibrations and the noise levels of an example MT capacitor are then compared with the results of an original capacitor. The comparison results show that the MT scheme designed in this paper can achieve a noise reduction effect of 12–15 dB(A). The proposed reduction method is proven to be both effective and efficient. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
39. Smart Transformer for Smart Grid—Intelligent Framework and Techniques for Power Transformer Asset Management.
- Author
-
Ma, Hui, Saha, Tapan K., Ekanayake, Chandima, and Martin, Daniel
- Abstract
Condition monitoring and diagnosis have become an essential part of power transformer asset management. A variety of online and offline measurements have been performed in utilities for evaluating different aspects of transformers’ conditions. However, properly processing measurement data and explicitly correlating these data to transformer condition is not a trivial task. This paper proposes an intelligent framework for condition monitoring and assessment of power transformer. Within this framework, various signal processing and pattern recognition techniques are applied for automatically denoising sensor acquired signals, extracting representative characteristics from raw data, and identifying types of faults in transformers. This paper provides case studies to demonstrate the effectiveness of the proposed framework and techniques for power transformer asset management. The hardware and software platform for implementing the proposed intelligent framework will also be presented in this paper. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
40. Contributions to Differences Between On-Site and Factory-Measured Noise Levels of Power Transformers.
- Author
-
Girgis, R. and Bernesjo, M.
- Subjects
SOUND measurement ,ELECTRIC transformers ,SPECTRUM allocation ,POWER transformers ,NOISE pollution - Abstract
Over the years, there have been a number of cases where users experienced higher noise levels of transformers on-site versus what was measured in the factory acceptance tests. In some of these cases, measurements have shown that a power transformer can have significantly different noise characteristics (both noise level and frequency spectrum) on-site compared to what was measured in the factory. This difference can range from a few decibels to more than 10 dB in some cases. Some of these differences are found to be caused by local environmental factors that influenced the on-site measurements. Others were caused by operating conditions on-site that are different from those of the factory tests. This paper presents results of investigations and measurements performed, over the past several years, on the main contributors to this difference. For each of these contributors, data are presented that demonstrate the impact of this contributor as well as quantify typical magnitudes of this impact. It is hoped that the material presented in this paper will assist users in: 1) understanding some of the pitfalls of on-site measurement of transformer noise; 2) how operating conditions contribute to the noise performance of transformers on-site; and 3) how significantly higher on-site noise levels can, in some cases, indicate an issue with the transformer or any of its components/accessories. It is also hoped that the material in this paper will contribute to industry standards/application guides on noise determination and abatement. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
41. Probability of Error Derivatives for Binary and Chaos-Based CDMA Systems in Wide-Band Channels.
- Author
-
Berber, Stevan M.
- Abstract
This paper presents detailed mathematical models of DS-CDMA systems based on binary and chaotic spreading sequences. These systems have been well investigated in the case of flat fading and noise presence in the channel. However, a comprehensive analysis of the systems operating in a wide-band channel does not exist. Therefore, in this paper, the systems are analyzed in detail, and expressions for the probability of error are derived in closed form assuming a wide-band transmission channel. Using both the signal representation in pure discrete time domain and the theory of discrete time stochastic processes, which have not been practically used before, the probability of error expressions are derived in closed form for single- and multi-user binary and chaos based DS-CDMA systems. The improvements in the probability of bit error due to multipath channel nature are quantified in dependence of the random delay and the number of users in the system. The wide-band channel is based on the Saleh-Valenzuela model proposed for the modern wireless networks. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
42. Spectrum Sensing Based on Maximum Generalized Correntropy Under Symmetric Alpha Stable Noise.
- Author
-
Liu, Mingqian, Zhao, Nan, Li, Junfang, and Leung, Victor C. M.
- Subjects
RECEIVING antennas ,NOISE ,SIGNAL-to-noise ratio - Abstract
In this corresponence paper, we address the spectrum sensing problem under the non-Gaussian noise scenario characterized by the symmetric alpha stable ($\text{S}\alpha \text{S}$) model. In this paper, a novel spectrum sensing method is proposed using the maximum generalized correntropy, aimed at improving the spectrum sensing performance in low generalized signal-to-noise ratio conditions. To further enhance the robustness of the proposed method, multiple receive antennas are applied to carry out cooperative spectrum sensing. Besides, a modified conjugate gradient algorithm is used to optimize the sparse vector for cooperative spectrum sensing. Finally, simulation results are presented to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
43. FRF Measurements Subject to Missing Data: Quantification of Noise, Nonlinear Distortion, and Time-Varying Effects.
- Author
-
Pintelon, Rik, Lataire, John, and Vandersteen, Gerd
- Subjects
WIRELESS sensor networks ,MISSING data (Statistics) ,PARAMETRIC modeling ,NOISE - Abstract
Quantifying the level of nonlinear distortions and time-varying effects in frequency response function measurements is a first step toward the selection of an appropriate parametric model structure. In this paper, we tackle this problem in the presence of missing data, which is an important issue in large-scale low-cost wireless sensor networks. The proposed method is based on one experiment with a special class of periodic excitation signals. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. Runway Detection and Tracking for Unmanned Aerial Vehicle Based on an Improved Canny Edge Detection Algorithm.
- Author
-
Wang, Xiaobing, Li, Baokui, and Geng, Qingbo
- Abstract
A new method based on an improved canny edge detection algorithm for the runway detection and tracking was presented in this paper. Though the traditional Canny Operator has high edge detection capability, it still can be interfered by grave image noise, as its detection accuracy cannot reach single pixel. This paper presented one method that combined Canny Operator with mean filter to represent the runway edge accurately. Then Hough Transform and Chain-Code was used for runway tracking. Experimental results show that this method can have better detection and tracking effect, besides the processing speed is also improved, that laid a favorable foundation for UAV visual navigation. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
45. The Theory of Special Noise Invariants.
- Author
-
Spasaro, Michele, Alimenti, Federico, and Zito, Domenico
- Subjects
LOW noise amplifiers ,NOISE ,RECIPROCALS (Mathematics) ,PORT districts ,NOISE measurement ,THEORY ,IMPEDANCE matching - Abstract
This paper reports a novel systematic theory of the noise invariants of two-port linear noisy networks under lossless reciprocal input and output impedance transformations. The theory clarifies the relationship between the circuit theory of linear noisy networks and the theory of four noise parameters, which are widely applied in the design of low-noise amplifiers (LNAs). In particular, we prove that the fundamental noise invariants under input and output impedance transformations are the eigenvalues of a permuted version of the noise correlation matrix and that there is no feedback operation that preserves them. Known invariants, such as the minimum equivalent noise temperature ${T}_{{N}{min}}$ and ${N}$ , may be expressed in terms of such eigenvalues. In addition, we provide a complete characterization of the four noise parameters of two-port passive dissipative networks in terms of their gain parameters and derive the condition under which the invariant ${4N}{T}_{{0}}{/}{T}_{{N}{min}}$ of passive nonreciprocal networks is lower than two. We also extend the theory of special noise invariants to LNAs with lossy input matching network. Overall, the impact of the findings emerging from the theory is highlighted through theorems, remarks, circuit examples, and studies on widespread design methodologies. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
46. Noise Filtering and Linearization of Single-Ended Sampled-Data Circuits.
- Author
-
He, Tao, Kareppagoudr, Manjunath, Zhang, Yi, Caceres, Emanuel, Moon, Un-Ku, and Temes, Gabor C.
- Subjects
ANALOG integrated circuits ,NOISE ,ANALOG circuits ,HARBOR management - Abstract
The performance of analog integrated circuits is often limited by the noise generated in its components. Several circuit techniques exist for mitigating the effects of the low-frequency noise. In this paper, a novel approach is described, which can also reduce even-order distortion, another major limitation of analog circuits. It may also allow the use of single-ended circuits in applications where usually differential structures are needed. In most cases, the resulting single-ended circuit will be much simpler than the fully or pseudo-differential one. It does not require common-mode feedback circuitry, nor single-ended-to-differential and differential-to-single-ended conversions at the input and output ports. The amplifiers may be single-ended, using, e.g., inverter-based circuits, and the use of baluns can be avoided. The number of pins and pads of the chip can be reduced. In addition, the single-ended opamps of the circuit may require less power than differential ones. These factors and the omission of the common-mode feedback circuits as well as the single-ended/differential converters will usually allow significant power savings. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
47. ASNI: Attenuated Signature Noise Injection for Low-Overhead Power Side-Channel Attack Immunity.
- Author
-
Das, Debayan, Maity, Shovan, Nasir, Saad Bin, Ghosh, Santosh, Raychowdhury, Arijit, and Sen, Shreyas
- Subjects
NOISE ,ELECTRIC potential - Abstract
Computationally-secure cryptographic algorithms implemented on a physical platform leak significant “side-channel” information through their power supplies. Correlational power attack is an efficient power side-channel attack (SCA) technique, which analyzes the statistical correlation between the estimated and the measured supply current traces to extract the secret key. The existing power SCA countermeasures are mainly based on reducing the SNR of the leaked information, power balancing, or gate-level masking, each of which introduces significant power, area or performance overheads, which calls for an efficient generic countermeasure. This paper presents ASNI: Attenuated Signature Noise Injection, which is an energy-efficient generic countermeasure, and shows SCA resistance on the AES-128 encryption as an application. ASNI uses a shunt low-drop-out (LDO) regulator to suppress the AES current signature by ${>}200 \times $ in the supply current traces. The shunt LDO has been fabricated and validated in 130 nm CMOS technology. System-level implementation of the ASNI, with the AES-128 core operating at 40 MHz, shows that the system remains secure even after 1 M encryptions, with $\sim 25 \times $ reduction in power overhead compared to that of noise addition alone. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
48. A Novel Three-Dimensional Analytical Approach for Acoustic Noise Modeling in Switched Reluctance Machines.
- Author
-
Liang, Jianbin, Callegaro, Alan Dorneles, Bilgin, Berker, and Emadi, Ali
- Subjects
NOISE ,ACOUSTIC models ,SWITCHED reluctance motors ,ACOUSTIC vibrations ,ACOUSTIC emission - Abstract
Acoustic noise modeling, analysis, and reduction are critical in the design of switched reluctance machines for noise-sensitive applications. Although the analytical method can provide a fast simulation of the acoustic noise, it is generally less accurate compared to the numerical method. In order to improve the simulation accuracy, a novel analytical method is presented in this paper. The proposed method considers the excitation of the high-axial-order vibration modes to simulate the vibration behavior and the acoustic noise in the three-dimensional (3D) domain. Methods of obtaining the input data for the 3D analytical simulations are presented. The acoustic noise results obtained from the numerical simulations and experiments from an 8/6 switched reluctance motor drive are used to validate the analytical method presented in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
49. Unsupervised Domain Adaptation of Deep Networks for ToF Depth Refinement.
- Author
-
Agresti, Gianluca, Schafer, Henrik, Sartor, Piergiorgio, Incesu, Yalcin, and Zanuttigh, Pietro
- Subjects
NOISE control ,DEEP learning ,MACHINE learning ,FREQUENCY-domain analysis ,NOISE ,MACHINE translating - Abstract
Depth maps acquired with ToF cameras have a limited accuracy due to the high noise level and to the multi-path interference. Deep networks can be used for refining ToF depth, but their training requires real world acquisitions with ground truth, which is complex and expensive to collect. A possible workaround is to train networks on synthetic data, but the domain shift between the real and synthetic data reduces the performances. In this paper, we propose three approaches to perform unsupervised domain adaptation of a depth denoising network from synthetic to real data. These approaches are respectively acting at the input, at the feature and at the output level of the network. The first approach uses domain translation networks to transform labeled synthetic ToF data into a representation closer to real data, that is then used to train the denoiser. The second approach tries to align the network internal features related to synthetic and real data. The third approach uses an adversarial loss, implemented with a discriminator trained to recognize the ground truth statistic, to train the denoiser on unlabeled real data. Experimental results show that the considered approaches are able to outperform other state-of-the-art techniques and achieve superior denoising performances. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
50. Full-Chip Signal Integrity Analysis and Optimization of 3-D ICs.
- Author
-
Song, Taigon, Liu, Chang, Peng, Yarui, and Lim, Sung Kyu
- Subjects
THROUGH-silicon via ,SIGNAL integrity (Electronics) ,SIGNAL theory ,INTEGRATED circuits ,MAGNETIC coupling ,VIA (Electricity) - Abstract
Through-silicon-via (TSV)-to-TSV coupling is a new phenomenon in 3-D ICs, and it becomes a significant source of signal integrity problems. The existing studies on its extraction and analysis, however, become inaccurate when handling more than two TSVs on full-chip scale. In this paper, we investigate the multiple TSV-to-TSV coupling issue and propose a model that can be efficiently used for full-chip extraction. Then, we perform an analysis on the impact of TSV parasitics on coupling and delay. Unlike the common belief that only the closest neighboring TSVs affect the victim, this paper shows that nonneighboring aggressors also cause nonnegligible coupling noise. Based on these observations, we propose an effective method of reducing the overall coupling level. [ABSTRACT FROM PUBLISHER]
- Published
- 2016
- Full Text
- View/download PDF
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