Additional Data Reduction Research Articles

Exploring the Impact of Youtube on Public Administration Students’ Communication Skills

The transition from traditional classroom-based language learning to online learning outside the classroom particularly in response to the global Covid-19 pandemic has transformed the way educators and learners approach teaching and learning activities. This research provides insights into the views of twelve Public Administration students on the use of YouTube videos for learning English digitally outside the classroom in their speaking class. The investigators utilized a qualitative research approach, conducting thorough in-depth interviews and observations. The initial step in analyzing the data of Public Administration students’ perception was data reduction, which was subsequently followed by additional data reduction and the drawing of conclusions. The results revealed that many of the participants concurred that YouTube had a substantial impact on their speaking class. Despite a small number of students encountering network-related issues, such as quota limitations or Fair Usage Policy (FUP) and advertisements, the study also demonstrated that this web application provided a free supplementary learning course for the speaking class.

Four-dimensional particle tracking velocimetry measurements of unsteady three-dimensional vortex onset and progression for 5415 straight ahead, static drift, and pure sway

Large-scale towed system four-dimensional particle tracking velocimetry (4DPTV) implementation and measurements are presented for towing tank tests for a naval combatant 5415 ship model for straight ahead, static drift β = 10°, and pure sway βmax = 10° conditions. The results, for the first time, provide instantaneous volumetric flow field data around the ship model including near the hull surface, and a complete description of the sonar dome 3D unsteady vortex separation onset and progression due to the 4DPTV larger measurement volume and higher data rates in comparison with previous results using tomographic particle image velocimetry (TPIV); thereby, providing the essential data required for the assessment of current hybrid Reynolds-averaged Navier–Stokes/large eddy simulation turbulence modeling capabilities and guidance for the necessary modeling improvements. The 4DPTV system is summarized and compared with the previous TPIV, including the camera calibration procedures, trigger systems, and synchronization with the sway motion. Analysis procedures, including data reduction procedures and the 3D vortex core detection and voxel labeling techniques, are described. The identification of the complex vortex separations and breakdown is aided using complementary detached eddy simulations. The vortex–vortex interaction process is visualized from instantaneous volumetric datasets. The pros and cons of the 4DPTV vs TPIV, the comparison between the second- and third-generation vortex visualization technique, and the statistical convergence error analysis of sonar dome port vortex for β = 10° are discussed. Plans for increased spatial resolution of the 4DPTV system and additional data reduction techniques for detailed turbulence analysis are also discussed.

An experimental analysis of the end-notched flexure composite laminates beams with elastic couplings

This paper presents an experimental study of the composite beams with elastic couplings subjected to the end-notched flexure (ENF) test. The object of research were carbon/epoxy composite laminates with specific stacking sequences exhibiting the bending–extension and the bending–twisting couplings. In addition, multidirectional laminates with different delamination interfaces were tested. Influence of elastic coupling phenomena on behavior of laminates subjected to the bending moment as well as on fracture toughness and delamination surfaces after the ENF tests was discussed. All experiments were performed according to the ASTM D7905 Standard. Determination of crack initiation was supported by the acoustic emission technique. Data analysis of the ENF test was performed by using both the direct beam theory and the corrected beam theory. Results obtained by using the classical data reduction schemes were compared with the compliance-based beam method (CBBM). Greater values of the fracture toughness obtained by using the non-standardized methods can be explained by the effect of the fracture process zone which was taken into account in the CBBM calculation scheme. Delamination surfaces of coupled laminates after the ENF tests were investigated by using the scanning electron microscopy. Results revealed that the effect of elastic couplings might influenced on intense bridging phenomena, more extensive fracture process zone and contribution of the mode III in total delamination resistance. Nevertheless, application of the standardized ENF procedure to determination of the fracture toughness of laminates exhibiting elastic couplings is still possible, provided assistance of additional data reduction schemes and techniques or numerical analysis.

Fast and accurate fuzzy C‐means algorithm for MR brain image segmentation

ABSTRACTFuzzy theory based intelligent techniques are widely preferred for medical applications because of high accuracy. Among the fuzzy based techniques, Fuzzy C‐Means (FCM) algorithm is popular than the other approaches due to the availability of expert knowledge. But, one of the hidden facts is that the computational complexity of the FCM algorithm is significantly high. Since medical applications need to be time effective, suitable modifications must be made in this algorithm for practical feasibility. In this study, necessary changes are included in the FCM approach to make the approach time effective without compromising the segmentation efficiency. An additional data reduction approach is performed in the conventional FCM to minimize the computational complexity and the convergence rate. A comparative analysis with the conventional FCM algorithm and the proposed Fast and Accurate FCM (FAFCM) is also given to show the superior nature of the proposed approach. These techniques are analyzed in terms of segmentation efficiency and convergence rate. Experimental results show promising results for the proposed approach. © 2016 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 188–195, 2016

Neuroimaging measures of error-processing: Extracting reliable signals from event-related potentials and functional magnetic resonance imaging

Error-related brain activity has become an increasingly important focus of cognitive neuroscience research utilizing both event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI). Given the significant time and resources required to collect these data, it is important for researchers to plan their experiments such that stable estimates of error-related processes can be achieved efficiently. Reliability of error-related brain measures will vary as a function of the number of error trials and the number of participants included in the averages. Unfortunately, systematic investigations of the number of events and participants required to achieve stability in error-related processing are sparse, and none have addressed variability in sample size. Our goal here is to provide data compiled from a large sample of healthy participants (n=180) performing a Go/NoGo task, resampled iteratively to demonstrate the relative stability of measures of error-related brain activity given a range of sample sizes and event numbers included in the averages. We examine ERP measures of error-related negativity (ERN/Ne) and error positivity (Pe), as well as event-related fMRI measures locked to False Alarms. We find that achieving stable estimates of ERP measures required four to six error trials and approximately 30 participants; fMRI measures required six to eight trials and approximately 40 participants. Fewer trials and participants were required for measures where additional data reduction techniques (i.e., principal component analysis and independent component analysis) were implemented. Ranges of reliability statistics for various sample sizes and numbers of trials are provided. We intend this to be a useful resource for those planning or evaluating ERP or fMRI investigations with tasks designed to measure error-processing.

Transparent Composite Model for DCT Coefficients: Design and Analysis

The distributions of discrete cosine transform (DCT) coefficients of images are revisited on a per image base. To better handle, the heavy tail phenomenon commonly seen in the DCT coefficients, a new model dubbed a transparent composite model (TCM) is proposed and justified for both modeling accuracy and an additional data reduction capability. Given a sequence of the DCT coefficients, a TCM first separates the tail from the main body of the sequence. Then, a uniform distribution is used to model the DCT coefficients in the heavy tail, whereas a different parametric distribution is used to model data in the main body. The separate boundary and other parameters of the TCM can be estimated via maximum likelihood estimation. Efficient online algorithms are proposed for parameter estimation and their convergence is also proved. Experimental results based on Kullback-Leibler divergence and χ(2) test show that for real-valued continuous ac coefficients, the TCM based on truncated Laplacian offers the best tradeoff between modeling accuracy and complexity. For discrete or integer DCT coefficients, the discrete TCM based on truncated geometric distributions (GMTCM) models the ac coefficients more accurately than pure Laplacian models and generalized Gaussian models in majority cases while having simplicity and practicality similar to those of pure Laplacian models. In addition, it is demonstrated that the GMTCM also exhibits a good capability of data reduction or feature extraction-the DCT coefficients in the heavy tail identified by the GMTCM are truly outliers, and these outliers represent an outlier image revealing some unique global features of the image. Overall, the modeling performance and the data reduction feature of the GMTCM make it a desirable choice for modeling discrete or integer DCT coefficients in the real-world image or video applications, as summarized in a few of our further studies on quantization design, entropy coding design, and image understanding and management.

Development of High Level Trigger Software for Belle II at SuperKEKB

The Belle collaboration has been trying for 10 years to reveal the mystery of the current matter-dominated universe. However, much more statistics is required to search for New Physics through quantum loops in decays of B mesons. In order to increase the experimental sensitivity, the next generation B-factory, SuperKEKB, is planned. The design luminosity of SuperKEKB is 8 x 1035cm−2s−1 a factor 40 above KEKB's peak luminosity. At this high luminosity, the level 1 trigger of the Belle II experiment will stream events of 300 kB size at a 30 kHz rate. To reduce the data flow to a manageable level, a high-level trigger (HLT) is needed, which will be implemented using the full offline reconstruction on a large scale PC farm. There, physics level event selection is performed, reducing the event rate by ∼ 10 to a few kHz. To execute the reconstruction the HLT uses the offline event processing framework basf2, which has parallel processing capabilities used for multi-core processing and PC clusters. The event data handling in the HLT is totally object oriented utilizing ROOT I/O with a new method of object passing over the UNIX socket connection. Also under consideration is the use of the HLT output as well to reduce the pixel detector event size by only saving hits associated with a track, resulting in an additional data reduction of ∼ 100 for the pixel detector. In this contribution, the design and implementation of the Belle II HLT are presented together with a report of preliminary testing results.

Qualitative JPEG 2000 Compression in Digital Mammography – Evaluation Using 480 Mammograms of the CDMAM Phantom

The DICOM standard supports both quantitative and qualitative lossy compression of mammograms.The purpose of this study was to investigate qualitative JPEG 2000 lossy compression and how different factors such as object thickness, radiation dose, and lossy compression levels affect image quality. The CDMAM phantom Artinis 3.4 was radiographed with 4 different object thicknesses and 5 different doses. The images were compressed at 10 different compression levels. The image quality was assessed by the software interpolated IQFinv value. Lossy 90 resulted in 89% data reduction, lossy 70 in 95% data reduction and lossy 60 in 96% data reduction. At higher compression levels (lossy 30), the resulting image quality ranged from 80-36%, and at low compression levels (lossy 90), it ranged from 89-93%. The object thickness was found to significantly interact with the compression level with regard to the resulting image quality: a higher object thickness resulted in increasingly poor image quality at increasing compression levels (p<0.05). Higher qualitative JPEG 2000 compression levels contribute only little additional data reduction, while the resulting image quality cannot be reliably predicted. Factors affecting image quality such as radiation dose and object thickness should be taken into account when performing image compression. Large object thicknesses should be compressed with caution because the loss of image quality is greater when intelligent data compression algorithms are used.

An overall MWPC-readout system based on chamber mounted ASICs

At the Julich Cooler Synchrotron, COSY, the magnetic spectrometer ANKE (Apparatus for Studies of Nucleon and Kaon Ejectils) is installed. Reaction products emitted by an internal target in the forward direction are measured. About 11000 channels are read out. This requirement justified the design of a VLSI based readout system. For this, an analog chip (RAL 118)-a low power high speed eight channel amplifier and discriminator-is used. Digital delay, zero suppression and address encoding are performed by the digital chip RAL 111 from the Rutherford Appleton Laboratory. A scalable and flexible array of chamber mounted front end boards may be adapted to instrument detectors of any size. Readout is performed by serializing hit addresses over a high speed optical link to a CAMAC readout module which serves for additional data reduction, subevent building and a number of test functions. Furthermore, subevent data are transferred using a front panel ECLbus (FERAbus*) to a crate controller with PCI-interface. An industrial PC with diskless UNIX-compatible operating system (NetBSD) is responsible for controlling the CAMAC crate, processing the event data and connecting to a central event builder.

Temperature effects on DC potential drop measurements made on a zirconium alloy plate specimen : Jones, K.I.; Frise, P.R. Insight, Vol. 38, No. 5, pp. 341–345 (May 1996)

A program to develop a DCPD crack measurement system for use on irradiated zirconium-niobium alloy nuclear reactor pressure-tube samples at high temperatures has required a series of tests to investigate the effect of high temperatures on the measurement system and data. The equipment and the test program are described, along with the results obtained. The tests have demonstrated that the DC system can function at the required temperatures (up to 250°C) but that some additional data reduction is required to remove or decrease the effect of the specimen temperature on the measurements.

A METHOD TO REDUCE THE SCATTER IN FATIGUE CRACK GROWTH RATE DATA

Abstract—The scatter in experimentally determined fatigue crack growth rates is dependent, in part, on the data reduction process applied to the paired values of crack length and number of cycles recorded in crack growth tests. An additional data reduction process is proposed which replaces the original test data by a smooth curve. Analysis of mid‐range growth rate data for Udimet 720 shows that the introduction of this additional data reduction procedure reduces the scatter in the calculated growth rates, increases the effectiveness of Walker's method in accounting for the effects of stress ratio, and leads to more accurate predictions of the experimental crack propagation lives of test specimens.

Observations on the Tearing of Elastomers

Abstract 1. Frequency distributions of stick-slip tear arrest and initiation energies have different standard deviations; initiation values show greater variance. Tear arrest frequency distributions are symmetrical and have been described by a normal distribution. The tear-initiation distribution is skewed and has been modeled using both the extreme value and Weibull distributions. As a result, it is concluded that two separate mechanisms are responsible for the creation of the force minima and maxima observed in stick-slip tearing. Consequently, data reduction methods which average these values to estimate tear energy are inappropriate. 2. The direction of skewness of the tear-initiation energies indicates a distribution of the largest extreme. This has been contrasted with constant-rate tensile-rupture data which are distributed according to the smallest extreme. As a result, it is concluded that the process responsible for tear initiation is not a weakest link mechanism, but, rather, depends on a process which structurally inhibits tear propagation. A mechanism of anisotropic tear-tip reinforcement caused by large regional deformation has been discussed as a possible explanation. 3. Tear energies calculated from tear-initiation forces have been shown to be dependent upon the energy stored in simple tensile extension and the volume of material available to be extended. This type of behavior shows that the tear-initiation energy is perhaps a reasonable indicator of strength but does not meet the criterion for an inherent material property. Tear-arrest values have been shown to be independent of these features and are considered unbiased estimators of inherent material tear energies. 4. It has been shown that for experimental purposes, stick-slip tearing can be eliminated and tear-tip diameter can be held constant using a constrained trouser-tear test. This is in agreement with earlier work by Gent and Henry. It has also been shown that the constrained tear energy thus measured is an inherent feature of stick-slip tearing results, requiring only additional data reduction to extract. Consequently, the constrained tear energy can be estimated from stick-slip tearing, and conversely, the magnitude of stick-slip tearing is predictable from a constrained tear energy and simple tensile extension data.