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Johnson noise thermometry near the zinc freezing point using resistance-based scaling

Johnson noise thermometry near the zinc freezing point using...

16th symposium on Thermophysical Properties/19th international Conference on Chemical Thermodynamics/61st Calorimetry Conference

作者： Tew, W. L. Labenski, J. R. Nam, S. W. Benz, S. P. dresselhaus, P. d. Burroughs, C. J. NIST Proc Measurement Div Gaithersburg MD 20899 USA Natl Inst Stand & Technol Div Optoelect Boulder CO 80303 USA Natl Inst Stand & Technol Quantum Elect Metrol Div Boulder CO 80303 USA

Johnson noise thermometry (JNT) is a primary method of measuring temperature which can be applied over wide ranges. The National Institute of Standards and Technology (NIST) is currently using JNT to determine the deviations of the international Temperature Scale of 1990 (ITS-90) from the thermodynamic temperature in the range of 505-933 K, overlapping the ranges of both acoustic gas-based and radiation-based thermometry. Advances in digital electronics have now made viable the computationally intensive and data-volume-intensive processing required for JNT using noise-voltage correlation in the frequency domain. The spectral noise power, and consequently the thermodynamic temperature T, of a high-temperature JNT probe is determined relative to a known reference spectrum using a switched-input digital noise-voltage correlator and simple resistance-scaling relationships. Comparison of the JNT results with standard platinum resistance thermometers calibrated on the ITS-90 gives the deviation of the thermodynamic temperature from the temperature on the ITS-90, T - T-90. Statistical uncertainties under 50 mu K center dot K-1 are achievable in less than 1 day of integration by fitting the effects of transmission-line time constants over bandwidths of 450 kHz. The methods and results in a 3 K interval near the zinc freezing point (T (90-ZnFP) equivalent to 692.677 K) are described. Preliminary results show agreement between the JNT-derived temperatures and the ITS-90.

关键词： ITS-90 Johnson noise noise thermometry temperature

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Privacy-preserving reputation management in fully decentralized systems: Challenges and opportunities

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The Joint international symposium on Artificial Intelligence and Natural Language processing, iSAI-NLP 2017

作者： Tran, Ngoc Hong Bahri, Leila Nguyen, Binh Quoc Vietnamese German University Thủ Dầu Một Viet Nam Koc University Istanbul Turkey

ISBN: (纸本)9783319947020

Reputation is one of crucial personal information strongly attached to each person, so it affects directly to its owner in whatever way it is used. Any form of reputation violation can carry a serious consequence to its owner. Therefore, reputation needs to be managed in a secure way. Moreover, reputation management is a substantial process as it plays a key role in building up a certain trust level, among just-met users. Thus just-met users can base on reputation scores to make a decision on starting up their communication. In addition, reputation management reduces risks of leaking user privacy and losing data security. So far, several works on managing reputation in online social network have been studied, mostly using the Internet for data transmission. In this work, reputation management is placed into the context of fully decentralized environment. Under the more harsh conditions which the decentralized mobile environment carries, such as no central node, frequently changed user location, and restrictions of energy, power, memory, etc., and the security requirement, methods of reputation management get more challenged. Various security problems of managing reputation are still open to be solved. In this work, we make a discussion about recent works on privacy-preserving reputation management in a decentralized environment. We then present challenges, and conclude the open problems as well as possible solutions in reputation management. © Springer Nature Switzerland AG 2019.

关键词： Environmental management

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Space Time Adaptive processing (STAP) using two dimensional array of real elements based on direct data domain Least Squares (d3LS) approach

Space Time Adaptive Processing (STAP) using two dimensional ...

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URSI international symposium on Signals, Systems, and Electronics (ISSSE)

作者： Hassan M. Elkamchouchi darwish A. E. Mohamed Wael A. E. Ali Department of Electrical Engineering Alexandria University Alexandria Egypt Department of Electronics and Communications Engineering AAST Alexandria Egypt

In this paper, STAP applied on signals from planar array of real elements using d 3 LS. The estimation of complex amplitude of Signal of Interest (SOI) will be difficult due to the strong mutual coupling between real elements. We have to eliminate the mutual coupling that exists between the antenna elements by using the transformation matrix. The transformation matrix converts the voltages that are induced at the loads corresponding to the feed point of the array elements to an equivalent set of voltages that will be induced by the same incident wave in Uniform Linear Virtual Array (ULVA) of isotropic point sources. A direct data domain Least Squares (d 3 LS) Space Time Adaptive processing (STAP) approach is presented for adaptively enhancing signals in a nonhomogeneous environment and will be applied on compensated voltages from transformation matrix. Numerical simulations are done using the three main methods of d 3 LS namely forward, backward, and forward-backward methods.

关键词： Arrays transmission line matrix methods Moment methods Interference Mutual coupling Planar arrays

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Frequency domain Signal-to-Noise Ratio Pre-processing for Fault Classification in Planetary Gear Systems Using Audio data

Frequency Domain Signal-to-Noise Ratio Pre-Processing for Fa...

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international symposium on Instrumentation Systems, Circuits and Transducers (INSCIT)

作者： Gustavo T. Gialluca Gabriel T. Gialluca Mateus Giesbrecht Fabiano Fruett DEEB FEEC University of Campinas (UNICAMP) Campinas Brazil University of Campinas (UNICAMP) Campinas Brazil

ISBN: (数字)9798350350869

ISBN: (纸本)9798350350876

Rotating machines commonly used in industries, such as planetary gears transmission systems, emit acoustic signals that contain significant information relating to the equipment's condition. Thus, the acquisition, processing and analysis of these signals are interesting procedures to enable the machine's working state monitoring. Given this scenario, we propose a technique for fault classification of planetary gear systems, based on a Frequency domain Signal-to-Noise Ratio (FdSNR) pre-processing algorithm, applied over the audio signals emitted from the gear system. The processing procedure feeds Supervised Machine Learning models such as Artificial Neural Networks and XGBoost. For our practical experiment, a planetary gear system was built in the laboratory, using a set of 3d-printed plastic gears and physical components and structures used for fixation and assembling purposes. By printing some anomalous gears, we could make replacements to alternate ordinary gears with anomalous ones, providing three different conditions for the apparatus: one normal configuration, and two anomalous conditions induced by a mass imbalance caused by the defective gears. Our final approach used: a microphone and an audio interface for acoustic capturing and audio recording; acoustic processing techniques that extract the key features from the audio files; and machine learning models that use these features to perform fault classification. The final experiment using the approach achieved a peak accuracy of 98% with an XGBoost model.

关键词： Accuracy Transducers Gears Frequency-domain analysis Machine learning Feature extraction Acoustics data models Circuit faults Signal to noise ratio

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Comparison of 3-d display and depth enhancement techniques

Proceedings of the SID

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Proceedings of the SId 1991年第1期32卷 25-29页

作者： Adelson, Stephen J. Badre, Albert N. Hodges, Larry F. Georgia Inst of Technology Atlanta United States

In scientific visualization, we often must model data with which we have little experience in the real world, such as simulating atmospheric turbulence or identifying stress points in a structure. In these models, it is important to be able to represent depth in an easily recognizable and unambiguous manner. In different applications, various methods are used to create the illusion of depth. We have tested five of these methods for their ability to facilitate depth perception and shape discrimination. Our results suggest that binary parallax is a superior technique and that vibration techniques are neither easy to use nor perceived as being helpful by users.

关键词： Image processing

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Time frequency and Kalman filter based baud rate estimator

Time frequency and Kalman filter based baud rate estimator

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international symposium on Image and Signal processing and Analysis

作者： d. Boulinguez C. Garnier Y. ves delignon L. Clavier ISEN/IEMN UMR CNRS 8520 Lille France ENIC/IEMN UMR CNRS 8520 Villeneuve d’ Ascq France CitB Scientifique-rue Marconi ENIC/IEMN UMR CNRS 8520 Villeneuve France

With the rising number of modulation types used in multiuser communication systems, we need to find efficient methods to discriminate them. Indeed, modulation recognition has become important in wireless communications for both civilian and military applications. Traditionally, to classify modulation types, most studies assume abundant a priori knowledge about modulated signals such as binary data rate, baud rate or carrier frequency. However, new transmission receiver systems need to classify automatically digital modulations without specific information. In the course of making decision on modulation type, these parameters may have to be estimated in order to perform efficient demodulation. This paper proposes a new way of estimating baud rate of digital modulated signals. This approach is based on abrupt changes detection in time-frequency plane and on abrupt change periodicity analysis using Kalman filtering.

关键词： Time frequency analysis Frequency estimation Signal analysis digital modulation data mining Information analysis Performance analysis Signal processing Image analysis Additive white noise

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Gaussian scale-space dense disparity estimation with anisotropic disparity-field diffusion

Gaussian scale-space dense disparity estimation with anisotr...

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international Conference on 3d Imaging, Modeling, processing, visualization and transmission (3dIMPVT)

作者： Jangheon Kim T. Sikora Department of Communication Systems Technical University Berlin Berlin Germany

We present a new reliable dense disparity estimation algorithm which employs Gaussian scale-space with anisotropic disparity-field diffusion. This algorithm estimates edge-preserving dense disparity vectors using a diffusive method on iteratively Gaussian-filtered images with a scale, i.e. the Gaussian scale-space. While a Gaussian filter kernel generates a coarser resolution from stereo image pairs, only strong and meaningful boundaries are adoptively selected on the resolution of the filtered images. Then, coarse global disparity vectors are initialized using the boundary constraint. The per-pixel disparity vectors are iteratively obtained by the local adjustment of the global disparity vectors using an energy-minimization framework. The proposed algorithm preserves the boundaries while inner regions are smoothed using anisotropic disparity-field diffusion. In this work, the Gaussian scale-space efficiently avoids illegal matching on a large baseline by the restriction of the range. Moreover, it prevents the computation from iterating into local minima of ill-posed diffusion on large gradient areas e.g. shadow and texture region, etc. The experimental results prove the excellent localization performance preserving the disparity discontinuity of each object.

关键词： Anisotropic magnetoresistance Iterative algorithms Energy resolution Gaussian processes Kernel Image resolution Adaptive filters data mining Feature extraction Computer vision

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Massive Parallel Fluid Flow Simulations Using Hierarchical data Format Version 5 (HdF5)

Massive Parallel Fluid Flow Simulations Using Hierarchical D...

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international symposium on Parallel and distributed Computing

作者： Christoph Ertl Jérôme Frisch Ralf-Peter Mundani Computation in Engineering Technical University of Munich Germany Institute of Energy Efficiency and Sustainable Building E3D RWTH Aachen University Germany

ISBN: (纸本)9781509041534

More and more massive parallel codes running on several hundreds of thousands of cores enter the computational science and engineering domain, allowing high-fidelity computations up to trillions of unknowns for very detailed analyses of the underlying problems. during such runs, typically gigabytes of data are being produced, hindering both efficient storage and (interactive) data exploration. Here, advanced approaches based on inherently distributed data formats such as HdF5 become necessary in order to avoid long latencies when storing the data and to support fast (random) access when retrieving the data for visual processing. Avoiding file locking and using collective buffering, we achieved write bandwiths to a single file close to the theoretical peak on a modern supercomputing cluster. The structure of our output file supports a very fast interactive visualisation and introduces additional steering functionality.

关键词： Mathematical model data structures visualization Servers distributed databases Computational modeling

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Key/Value-Enabled Flash Memory for Complex Scientific Workflows with On-Line Analysis and visualization

Key/Value-Enabled Flash Memory for Complex Scientific Workfl...

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international symposium on Parallel and distributed processing (IPdPS)

作者： Stefan Eilemann Fabien delalondre Jon Bernard Judit Planas Felix Schuermann John Biddiscombe Costas Bekas Alessandro Curioni Bernard Metzler Peter Kaltstein Peter Morjan Joachim Fenkes Ralph Bellofatto Lars Schneidenbach T. J. Christopher Ward Blake G. Fitch Blue Brain Project Ecole Polytechnique Fédérale de Lausanne Geneva Switzerland Ecole Polytechnique Federale de Lausanne Lausanne VD CH CSCS Swiss Nat. Supercomput. Centre Lugano Switzerland IBM Research Zurich Rueschlikon Switzerland IBM Deutschland Research & Development GmbH Boblingen Germany IBM Thomas J Watson Research Center Yorktown Heights NY US IBM T.J. Watson Research Center Yorktown Heights NY USA IBM Software Group Hursley U.K.

ISBN: (纸本)9781509021413

Scientific workflows are often composed of compute-intensive simulations and data-intensive analysis and visualization, both equally important for productivity. High-performance computers run the compute-intensive phases efficiently, but data-intensive processing is still getting less attention. dense non-volatile memory integrated into super-computers can help address this problem. In addition to density, it offers significantly finer-grained I/O than disk-based I/O systems. We present a way to exploit the fundamental capabilities of Storage-Class Memories (SCM), such as Flash, by using scalable key-value (KV) I/O methods instead of traditional file I/O calls commonly used in HPC systems. Our objective is to enable higher performance for on-line and near-line storage for analysis and visualization of very high resolution, but correspondingly transient, simulation results. In this paper, we describe 1) the adaptation of a scalable key-value store to a BlueGene/Q system with integrated Flash memory, 2) a novel key-value aggregation module which implements coalesced, function-shipped calls between the clients and the servers, and 3) the refactoring of a scientific workflow to use application-relevant keys for fine-grained data subsets. The resulting implementation is analogous to function-shipping of POSIX I/O calls but shows an order of magnitude increase in read and a factor 2.5x increase in write IOPS performance (11 million read IOPS, 2.5 million write IOPS from 4096 compute nodes) when compared to a classical file system on the same system. It represents an innovative approach for the integration of SCM within an HPC system at scale.

关键词： Ions Flash memories Software data visualization Servers Electronic mail Nonvolatile memory

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Haptic Identification of Stiffness and Force Magnitude

Haptic Identification of Stiffness and Force Magnitude

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international symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (HAPTICS)

作者： Steven A. Cholewiak Hong Z. Tan david S. Ebert Haptic Interface Research Laboratory Purdue University West Lafayette IN USA Renderin & Perceptualization Laboratory Purdue University West Lafayette IN USA

As haptics becomes an integral component of scientific data visualization systems, there is a growing need to study "haptic glyphs" (building blocks for displaying information through the sense of touch) and quantify their information transmission capability. The present study investigated the channel capacity for transmitting information through stiffness or force magnitude. Specifically, we measured the number of stiffness or force- magnitude levels that can be reliably identified in an absolute identification paradigm. The range of stiffness and force magnitude used in the present study, 0.2-3.0 N/mm and 0.1-5.0 N, respectively, was typical of the parameter values encountered in most virtual reality or data visualization applications. Ten individuals participated in a stiffness identification experiment, each completing 250 trials. Subsequently, four of these individuals and six additional participants completed 250 trials in a force-magnitude identification experiment. A custom-designed 3 degrees-of-freedom force-feedback device, the ministick, was used for stimulus delivery. The results showed an average information transfer of 1.46 bits for stiffness identification, or equivalently, 2.8 correctly-identifiable stiffness levels. The average information transfer for force magnitude was 1.54 bits, or equivalently, 2.9 correctly-identifiable force magnitudes. Therefore, on average, the participants could only reliably identify 2-3 stiffness levels in the range of 0.2-3.0 N/mm, and 2-3 force- magnitude levels in the range of 0.1-5.0 N. Individual performance varied from 1 to 4 correctly-identifiable stiffness levels and 2 to 4 correctly-identifiable force-magnitude levels. Our results are consistent with reported information transfers for haptic stimuli. Based on the present study, it is recommended that 2 stiffness or force-magnitude levels (i.e., high and low) be used with haptic glyphs in a data visualization system, with an additional third level (medium) for mo

关键词： Haptic interfaces data visualization Signal processing Channel capacity Laboratories Rendering (computer graphics) Information analysis Auditory displays Feedback Guidelines

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