DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, S; Zhu, X; Zhang, M

Purpose Half-beam block is a field matching technique frequently used in radiotherapy. With no setup error, a well calibrated linac, and no internal organ motion, two photon fields can be matched seamlessly dosimetry-wise with their central axes passing the match line. However, in actual clinical situations, internal organ motion is often inevitable. This study was conducted to investigate its influence on radiation dose to patient internal points directly under the matching line. Methods A clinical setting is modeled as two half-space (x<0 and x<0) radiation fields that are turned on sequentially with a time gap of integer times of themore » patient internal organ motion period (T{sub 0}). Our point of interest moves with patient internal organs periodically and evenly in and out of the radiation fields, resulting in an average location at x=0. When the fields are delivered without any motion management, the initial phase of the point’s movement is unknown. Statistical methods are used to compute the expected value () and variance (σ) of the point dose given the uncertainty. Results Analytical solutions are obtained for and s of dose received by a point directly under the match line. is proportional to the total beam-on time (T1), and σ demonstrates previously unknown periodic behavior. /« less

Direct migration motion estimation and mode decision to decoder for a low-complexity decoder Wyner-Ziv video coding

NASA Astrophysics Data System (ADS)

Lei, Ted Chih-Wei; Tseng, Fan-Shuo

2017-07-01

This paper addresses the problem of high-computational complexity decoding in traditional Wyner-Ziv video coding (WZVC). The key focus is the migration of two traditionally high-computationally complex encoder algorithms, namely motion estimation and mode decision. In order to reduce the computational burden in this process, the proposed architecture adopts the partial boundary matching algorithm and four flexible types of block mode decision at the decoder. This approach does away with the need for motion estimation and mode decision at the encoder. The experimental results show that the proposed padding block-based WZVC not only decreases decoder complexity to approximately one hundredth that of the state-of-the-art DISCOVER decoding but also outperforms DISCOVER codec by up to 3 to 4 dB.

Dictionary learning-based spatiotemporal regularization for 3D dense speckle tracking

NASA Astrophysics Data System (ADS)

Lu, Allen; Zontak, Maria; Parajuli, Nripesh; Stendahl, John C.; Boutagy, Nabil; Eberle, Melissa; O'Donnell, Matthew; Sinusas, Albert J.; Duncan, James S.

2017-03-01

Speckle tracking is a common method for non-rigid tissue motion analysis in 3D echocardiography, where unique texture patterns are tracked through the cardiac cycle. However, poor tracking often occurs due to inherent ultrasound issues, such as image artifacts and speckle decorrelation; thus regularization is required. Various methods, such as optical flow, elastic registration, and block matching techniques have been proposed to track speckle motion. Such methods typically apply spatial and temporal regularization in a separate manner. In this paper, we propose a joint spatiotemporal regularization method based on an adaptive dictionary representation of the dense 3D+time Lagrangian motion field. Sparse dictionaries have good signal adaptive and noise-reduction properties; however, they are prone to quantization errors. Our method takes advantage of the desirable noise suppression, while avoiding the undesirable quantization error. The idea is to enforce regularization only on the poorly tracked trajectories. Specifically, our method 1.) builds data-driven 4-dimensional dictionary of Lagrangian displacements using sparse learning, 2.) automatically identifies poorly tracked trajectories (outliers) based on sparse reconstruction errors, and 3.) performs sparse reconstruction of the outliers only. Our approach can be applied on dense Lagrangian motion fields calculated by any method. We demonstrate the effectiveness of our approach on a baseline block matching speckle tracking and evaluate performance of the proposed algorithm using tracking and strain accuracy analysis.

Speeding up 3D speckle tracking using PatchMatch

NASA Astrophysics Data System (ADS)

Zontak, Maria; O'Donnell, Matthew

2016-03-01

Echocardiography provides valuable information to diagnose heart dysfunction. A typical exam records several minutes of real-time cardiac images. To enable complete analysis of 3D cardiac strains, 4-D (3-D+t) echocardiography is used. This results in a huge dataset and requires effective automated analysis. Ultrasound speckle tracking is an effective method for tissue motion analysis. It involves correlation of a 3D kernel (block) around a voxel with kernels in later frames. The search region is usually confined to a local neighborhood, due to biomechanical and computational constraints. For high strains and moderate frame-rates, however, this search region will remain large, leading to a considerable computational burden. Moreover, speckle decorrelation (due to high strains) leads to errors in tracking. To solve this, spatial motion coherency between adjacent voxels should be imposed, e.g., by averaging their correlation functions.1 This requires storing correlation functions for neighboring voxels, thus increasing memory demands. In this work, we propose an efficient search using PatchMatch, 2 a powerful method to find correspondences between images. Here we adopt PatchMatch for 3D volumes and radio-frequency signals. As opposed to an exact search, PatchMatch performs random sampling of the search region and propagates successive matches among neighboring voxels. We show that: 1) Inherently smooth offset propagation in PatchMatch contributes to spatial motion coherence without any additional processing or memory demand. 2) For typical scenarios, PatchMatch is at least 20 times faster than the exact search, while maintaining comparable tracking accuracy.

A motion compensation technique using sliced blocks and its application to hybrid video coding

NASA Astrophysics Data System (ADS)

Kondo, Satoshi; Sasai, Hisao

2005-07-01

This paper proposes a new motion compensation method using "sliced blocks" in DCT-based hybrid video coding. In H.264 ? MPEG-4 Advance Video Coding, a brand-new international video coding standard, motion compensation can be performed by splitting macroblocks into multiple square or rectangular regions. In the proposed method, on the other hand, macroblocks or sub-macroblocks are divided into two regions (sliced blocks) by an arbitrary line segment. The result is that the shapes of the segmented regions are not limited to squares or rectangles, allowing the shapes of the segmented regions to better match the boundaries between moving objects. Thus, the proposed method can improve the performance of the motion compensation. In addition, adaptive prediction of the shape according to the region shape of the surrounding macroblocks can reduce overheads to describe shape information in the bitstream. The proposed method also has the advantage that conventional coding techniques such as mode decision using rate-distortion optimization can be utilized, since coding processes such as frequency transform and quantization are performed on a macroblock basis, similar to the conventional coding methods. The proposed method is implemented in an H.264-based P-picture codec and an improvement in bit rate of 5% is confirmed in comparison with H.264.

Rotational waves in geodynamics

NASA Astrophysics Data System (ADS)

Gerus, Artyom; Vikulin, Alexander

2015-04-01

The rotation model of a geoblock with intrinsic momentum was constructed by A.V. Vikulin and A.G. Ivanchin [9, 10] to describe seismicity within the Pacific Ocean margin. It is based on the idea of a rotational motion of geoblocks as the parts of the rotating body of the Earth that generates rotary deformation waves. The law of the block motion was derived in the form of the sine-Gordon equation (SG) [5, 9]; the dimensionless form of the equation is: δ2θ δ2θ δξ2 - δη2 = sinθ, (1) where θ = β/2, ξ = k0z and η = v0k0t are dimensionless coordinates, z - length of the chain of masses (blocks), t - time, β - turn angle, ν0 - representative velocity of the process, k0 - wave number. Another case analyzed was a chain of nonuniformly rotating blocks, with deviation of force moments from equilibrium positions μ, considering friction forces α along boundaries, which better matched a real-life seismic process. As a result, the authors obtained the law of motion for a block in a chain in the form of the modified SG equation [8]: δ2θ δ2θ δθ- δξ2 - δ η2 = sin θ+ α δη + μδ(ξ)sin θ (2)

Seismic motion in urban sites consisting of blocks in welded contact with a soft layer overlying a hard half-space

NASA Astrophysics Data System (ADS)

Groby, Jean-Philippe; Wirgin, Armand

2008-02-01

We address the problem of the response to a seismic wave of an urban site consisting of Nb blocks overlying a soft layer underlain by a hard substratum. The results of a theoretical analysis, appealing to a space-frequency mode-matching (MM) technique, are compared to those obtained by a space-time finite-element (FE) technique. The two methods are shown to give rise to the same prediction of the seismic response for Nb = 1, 2 and 40 blocks. The mechanism of the interaction between blocks and the ground, as well as that of the mutual interaction between blocks, are studied. It is shown, in the first part of this paper, that the presence of a small number of blocks modifies the seismic disturbance in a manner which evokes qualitatively, but not quantitatively, what was observed during the 1985 Michoacan earthquake in Mexico City. Anomalous earthquake response at a much greater level, in terms of duration, peak and cumulative amplitude of motion, is shown, by a theoretical and numerical analysis in the second part of this paper, to be induced by the presence of a large (>=10) number of identical equi-spaced blocks that are present in certain districts of many cities.

SU-G-JeP1-07: Development of a Programmable Motion Testbed for the Validation of Ultrasound Tracking Algorithms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shepard, A; Matrosic, C; Zagzebski, J

Purpose: To develop an advanced testbed that combines a 3D motion stage and ultrasound phantom to optimize and validate 2D and 3D tracking algorithms for real-time motion management during radiation therapy. Methods: A Siemens S2000 Ultrasound scanner utilizing a 9L4 transducer was coupled with the Washington University 4D Phantom to simulate patient motion. The transducer was securely fastened to the 3D stage and positioned to image three cylinders of varying contrast in a Gammex 404GS LE phantom. The transducer was placed within a water bath above the phantom in order to maintain sufficient coupling for the entire range of simulatedmore » motion. A programmed motion sequence was used to move the transducer during image acquisition and a cine video was acquired for one minute to allow for long sequence tracking. Images were analyzed using a normalized cross-correlation block matching tracking algorithm and compared to the known motion of the transducer relative to the phantom. Results: The setup produced stable ultrasound motion traces consistent with those programmed into the 3D motion stage. The acquired ultrasound images showed minimal artifacts and an image quality that was more than suitable for tracking algorithm verification. Comparisons of a block matching tracking algorithm with the known motion trace for the three features resulted in an average tracking error of 0.59 mm. Conclusion: The high accuracy and programmability of the 4D phantom allows for the acquisition of ultrasound motion sequences that are highly customizable; allowing for focused analysis of some common pitfalls of tracking algorithms such as partial feature occlusion or feature disappearance, among others. The design can easily be modified to adapt to any probe such that the process can be extended to 3D acquisition. Further development of an anatomy specific phantom better resembling true anatomical landmarks could lead to an even more robust validation. This work is partially funded by NIH grant R01CA190298.« less

Edge-driven microplate kinematics

USGS Publications Warehouse

Schouten, Hans; Klitgord, Kim D.; Gallo, David G.

1993-01-01

It is known from plate tectonic reconstructions that oceanic microplates undergo rapid rotation about a vertical axis and that the instantaneous rotation axes describing the microplate's motion relative to the bounding major plates are frequently located close to its margins with those plates, close to the tips of propagating rifts. We propose a class of edge-driven block models to illustrate how slip across the microplate margins, block rotation, and propagation of rifting may be related to the relative motion of the plates on either side. An important feature of these edge-driven models is that the instantaneous rotation axes are always located on the margins between block and two bounding plates. According to those models the pseudofaults or traces of disrupted seafloor resulting from the propagation of rifting between microplate and major plates may be used independently to approximately trace the continuous kinematic evolution of the microplate back in time. Pseudofault geometries and matching rotations of the Easter microplate show that for most of its 5 m.y. history, block rotation could be driven by the drag of the Nazca and Pacific plates on the microplate's edges rather than by a shear flow of mantle underneath.

New Directions in the Digital Signal Processing of Image Data.

DTIC Science & Technology

1987-05-01

and identify by block number) FIELD GROUP SUB-GROUP Object detection and idLntification 12 01 restoration of photon noise limited imagery 15 04 image...from incomplete information, restoration of blurred images in additive and multiplicative noise , motion analysis with fast hierarchical algorithms...different resolutions. As is well known, the solution to the matched filter problem under additive white noise conditions is the correlation receiver

Novel true-motion estimation algorithm and its application to motion-compensated temporal frame interpolation.

PubMed

Dikbas, Salih; Altunbasak, Yucel

2013-08-01

In this paper, a new low-complexity true-motion estimation (TME) algorithm is proposed for video processing applications, such as motion-compensated temporal frame interpolation (MCTFI) or motion-compensated frame rate up-conversion (MCFRUC). Regular motion estimation, which is often used in video coding, aims to find the motion vectors (MVs) to reduce the temporal redundancy, whereas TME aims to track the projected object motion as closely as possible. TME is obtained by imposing implicit and/or explicit smoothness constraints on the block-matching algorithm. To produce better quality-interpolated frames, the dense motion field at interpolation time is obtained for both forward and backward MVs; then, bidirectional motion compensation using forward and backward MVs is applied by mixing both elegantly. Finally, the performance of the proposed algorithm for MCTFI is demonstrated against recently proposed methods and smoothness constraint optical flow employed by a professional video production suite. Experimental results show that the quality of the interpolated frames using the proposed method is better when compared with the MCFRUC techniques.

Acceleration of block-matching algorithms using a custom instruction-based paradigm on a Nios II microprocessor

NASA Astrophysics Data System (ADS)

González, Diego; Botella, Guillermo; García, Carlos; Prieto, Manuel; Tirado, Francisco

2013-12-01

This contribution focuses on the optimization of matching-based motion estimation algorithms widely used for video coding standards using an Altera custom instruction-based paradigm and a combination of synchronous dynamic random access memory (SDRAM) with on-chip memory in Nios II processors. A complete profile of the algorithms is achieved before the optimization, which locates code leaks, and afterward, creates a custom instruction set, which is then added to the specific design, enhancing the original system. As well, every possible memory combination between on-chip memory and SDRAM has been tested to achieve the best performance. The final throughput of the complete designs are shown. This manuscript outlines a low-cost system, mapped using very large scale integration technology, which accelerates software algorithms by converting them into custom hardware logic blocks and showing the best combination between on-chip memory and SDRAM for the Nios II processor.

SU-G-BRA-02: Development of a Learning Based Block Matching Algorithm for Ultrasound Tracking in Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shepard, A; Bednarz, B

Purpose: To develop an ultrasound learning-based tracking algorithm with the potential to provide real-time motion traces of anatomy-based fiducials that may aid in the effective delivery of external beam radiation. Methods: The algorithm was developed in Matlab R2015a and consists of two main stages: reference frame selection, and localized block matching. Immediately following frame acquisition, a normalized cross-correlation (NCC) similarity metric is used to determine a reference frame most similar to the current frame from a series of training set images that were acquired during a pretreatment scan. Segmented features in the reference frame provide the basis for the localizedmore » block matching to determine the feature locations in the current frame. The boundary points of the reference frame segmentation are used as the initial locations for the block matching and NCC is used to find the most similar block in the current frame. The best matched block locations in the current frame comprise the updated feature boundary. The algorithm was tested using five features from two sets of ultrasound patient data obtained from MICCAI 2014 CLUST. Due to the lack of a training set associated with the image sequences, the first 200 frames of the image sets were considered a valid training set for preliminary testing, and tracking was performed over the remaining frames. Results: Tracking of the five vessel features resulted in an average tracking error of 1.21 mm relative to predefined annotations. The average analysis rate was 15.7 FPS with analysis for one of the two patients reaching real-time speeds. Computations were performed on an i5-3230M at 2.60 GHz. Conclusion: Preliminary tests show tracking errors comparable with similar algorithms at close to real-time speeds. Extension of the work onto a GPU platform has the potential to achieve real-time performance, making tracking for therapy applications a feasible option. This work is partially funded by NIH grant R01CA190298.« less

High Performance Compression of Science Data

NASA Technical Reports Server (NTRS)

Storer, James A.; Carpentieri, Bruno; Cohn, Martin

1994-01-01

Two papers make up the body of this report. One presents a single-pass adaptive vector quantization algorithm that learns a codebook of variable size and shape entries; the authors present experiments on a set of test images showing that with no training or prior knowledge of the data, for a given fidelity, the compression achieved typically equals or exceeds that of the JPEG standard. The second paper addresses motion compensation, one of the most effective techniques used in interframe data compression. A parallel block-matching algorithm for estimating interframe displacement of blocks with minimum error is presented. The algorithm is designed for a simple parallel architecture to process video in real time.

Joint range of motion after total shoulder arthroplasty with and without a continuous interscalene nerve block: a retrospective, case-control study.

PubMed

Ilfeld, Brian M; Wright, Thomas W; Enneking, F Kayser; Morey, Timothy E

2005-01-01

Although a continuous interscalene nerve block (CISB) has been shown to provide potent analgesia after major shoulder surgery, its potential effects on postoperative rehabilitation remain uninvestigated. Therefore, this retrospective case-control study was undertaken to determine the association between CISB and joint range-of-motion after total shoulder arthroplasty (TSA). The medical records for patients who underwent TSA at our institution in the previous 3 years were examined. Each patient with a CISB (cases) was matched with a patient without a CISB (controls) for the following variables: age, gender, and TSA type (primary v revision). Data collected included maximum shoulder elevation and external rotation (primary endpoints), along with pre- and postoperative pain scores. Of 134 charts reviewed, 25 cases were matched with an equal number of controls. On postoperative day 1, patients with or without a CISB achieved a median (5th-95th percentiles) of 85% (51-100) and 33% (11-56) of their surgeon-defined goal for elevation (P = .048), respectively, and attained 100% (33-100) and 17% (-81-68) for external rotation (P < .001), respectively. The median numeric rating pain score (NRS) during shoulder movement for patients with CISB was 2.0 (0.0-8.7) versus 8.5 (1.8-10.0) for patients without CISB (P < .001). Least, median, and highest resting NRS for the 24 hours after surgery were 0.0 (0.0-5.8), 1.0 (0.0-6.4), and 3.0 (0.0-9.0) for patients with CISB, respectively, versus 2.0 (0.0-7.7), 6.0 (0.3-9.6), and 8.0 (0.0-10.0) for patients without CISB (P = .030, P < .001, and P < .001 between groups, respectively). The day after TSA, a CISB is associated with increased shoulder range of motion, most likely resulting from the potent analgesia these nerve blocks provide.

High performance compression of science data

NASA Technical Reports Server (NTRS)

Storer, James A.; Cohn, Martin

1994-01-01

Two papers make up the body of this report. One presents a single-pass adaptive vector quantization algorithm that learns a codebook of variable size and shape entries; the authors present experiments on a set of test images showing that with no training or prior knowledge of the data, for a given fidelity, the compression achieved typically equals or exceeds that of the JPEG standard. The second paper addresses motion compensation, one of the most effective techniques used in the interframe data compression. A parallel block-matching algorithm for estimating interframe displacement of blocks with minimum error is presented. The algorithm is designed for a simple parallel architecture to process video in real time.

Unsupervised motion-based object segmentation refined by color

NASA Astrophysics Data System (ADS)

Piek, Matthijs C.; Braspenning, Ralph; Varekamp, Chris

2003-06-01

For various applications, such as data compression, structure from motion, medical imaging and video enhancement, there is a need for an algorithm that divides video sequences into independently moving objects. Because our focus is on video enhancement and structure from motion for consumer electronics, we strive for a low complexity solution. For still images, several approaches exist based on colour, but these lack in both speed and segmentation quality. For instance, colour-based watershed algorithms produce a so-called oversegmentation with many segments covering each single physical object. Other colour segmentation approaches exist which somehow limit the number of segments to reduce this oversegmentation problem. However, this often results in inaccurate edges or even missed objects. Most likely, colour is an inherently insufficient cue for real world object segmentation, because real world objects can display complex combinations of colours. For video sequences, however, an additional cue is available, namely the motion of objects. When different objects in a scene have different motion, the motion cue alone is often enough to reliably distinguish objects from one another and the background. However, because of the lack of sufficient resolution of efficient motion estimators, like the 3DRS block matcher, the resulting segmentation is not at pixel resolution, but at block resolution. Existing pixel resolution motion estimators are more sensitive to noise, suffer more from aperture problems or have less correspondence to the true motion of objects when compared to block-based approaches or are too computationally expensive. From its tendency to oversegmentation it is apparent that colour segmentation is particularly effective near edges of homogeneously coloured areas. On the other hand, block-based true motion estimation is particularly effective in heterogeneous areas, because heterogeneous areas improve the chance a block is unique and thus decrease the chance of the wrong position producing a good match. Consequently, a number of methods exist which combine motion and colour segmentation. These methods use colour segmentation as a base for the motion segmentation and estimation or perform an independent colour segmentation in parallel which is in some way combined with the motion segmentation. The presented method uses both techniques to complement each other by first segmenting on motion cues and then refining the segmentation with colour. To our knowledge few methods exist which adopt this approach. One example is te{meshrefine}. This method uses an irregular mesh, which hinders its efficient implementation in consumer electronics devices. Furthermore, the method produces a foreground/background segmentation, while our applications call for the segmentation of multiple objects. NEW METHOD As mentioned above we start with motion segmentation and refine the edges of this segmentation with a pixel resolution colour segmentation method afterwards. There are several reasons for this approach: + Motion segmentation does not produce the oversegmentation which colour segmentation methods normally produce, because objects are more likely to have colour discontinuities than motion discontinuities. In this way, the colour segmentation only has to be done at the edges of segments, confining the colour segmentation to a smaller part of the image. In such a part, it is more likely that the colour of an object is homogeneous. + This approach restricts the computationally expensive pixel resolution colour segmentation to a subset of the image. Together with the very efficient 3DRS motion estimation algorithm, this helps to reduce the computational complexity. + The motion cue alone is often enough to reliably distinguish objects from one another and the background. To obtain the motion vector fields, a variant of the 3DRS block-based motion estimator which analyses three frames of input was used. The 3DRS motion estimator is known for its ability to estimate motion vectors which closely resemble the true motion. BLOCK-BASED MOTION SEGMENTATION As mentioned above we start with a block-resolution segmentation based on motion vectors. The presented method is inspired by the well-known K-means segmentation method te{K-means}. Several other methods (e.g. te{kmeansc}) adapt K-means for connectedness by adding a weighted shape-error. This adds the additional difficulty of finding the correct weights for the shape-parameters. Also, these methods often bias one particular pre-defined shape. The presented method, which we call K-regions, encourages connectedness because only blocks at the edges of segments may be assigned to another segment. This constrains the segmentation method to such a degree that it allows the method to use least squares for the robust fitting of affine motion models for each segment. Contrary to te{parmkm}, the segmentation step still operates on vectors instead of model parameters. To make sure the segmentation is temporally consistent, the segmentation of the previous frame will be used as initialisation for every new frame. We also present a scheme which makes the algorithm independent of the initially chosen amount of segments. COLOUR-BASED INTRA-BLOCK SEGMENTATION The block resolution motion-based segmentation forms the starting point for the pixel resolution segmentation. The pixel resolution segmentation is obtained from the block resolution segmentation by reclassifying pixels only at the edges of clusters. We assume that an edge between two objects can be found in either one of two neighbouring blocks that belong to different clusters. This assumption allows us to do the pixel resolution segmentation on each pair of such neighbouring blocks separately. Because of the local nature of the segmentation, it largely avoids problems with heterogeneously coloured areas. Because no new segments are introduced in this step, it also does not suffer from oversegmentation problems. The presented method has no problems with bifurcations. For the pixel resolution segmentation itself we reclassify pixels such that we optimize an error norm which favour similarly coloured regions and straight edges. SEGMENTATION MEASURE To assist in the evaluation of the proposed algorithm we developed a quality metric. Because the problem does not have an exact specification, we decided to define a ground truth output which we find desirable for a given input. We define the measure for the segmentation quality as being how different the segmentation is from the ground truth. Our measure enables us to evaluate oversegmentation and undersegmentation seperately. Also, it allows us to evaluate which parts of a frame suffer from oversegmentation or undersegmentation. The proposed algorithm has been tested on several typical sequences. CONCLUSIONS In this abstract we presented a new video segmentation method which performs well in the segmentation of multiple independently moving foreground objects from each other and the background. It combines the strong points of both colour and motion segmentation in the way we expected. One of the weak points is that the segmentation method suffers from undersegmentation when adjacent objects display similar motion. In sequences with detailed backgrounds the segmentation will sometimes display noisy edges. Apart from these results, we think that some of the techniques, and in particular the K-regions technique, may be useful for other two-dimensional data segmentation problems.

Language comprehension warps the mirror neuron system.

PubMed

Zarr, Noah; Ferguson, Ryan; Glenberg, Arthur M

2013-01-01

Is the mirror neuron system (MNS) used in language understanding? According to embodied accounts of language comprehension, understanding sentences describing actions makes use of neural mechanisms of action control, including the MNS. Consequently, repeatedly comprehending sentences describing similar actions should induce adaptation of the MNS thereby warping its use in other cognitive processes such as action recognition and prediction. To test this prediction, participants read blocks of multiple sentences where each sentence in the block described transfer of objects in a direction away or toward the reader. Following each block, adaptation was measured by having participants predict the end-point of videotaped actions. The adapting sentences disrupted prediction of actions in the same direction, but (a) only for videos of biological motion, and (b) only when the effector implied by the language (e.g., the hand) matched the videos. These findings are signatures of the MNS.

Language comprehension warps the mirror neuron system

PubMed Central

Zarr, Noah; Ferguson, Ryan; Glenberg, Arthur M.

2013-01-01

Is the mirror neuron system (MNS) used in language understanding? According to embodied accounts of language comprehension, understanding sentences describing actions makes use of neural mechanisms of action control, including the MNS. Consequently, repeatedly comprehending sentences describing similar actions should induce adaptation of the MNS thereby warping its use in other cognitive processes such as action recognition and prediction. To test this prediction, participants read blocks of multiple sentences where each sentence in the block described transfer of objects in a direction away or toward the reader. Following each block, adaptation was measured by having participants predict the end-point of videotaped actions. The adapting sentences disrupted prediction of actions in the same direction, but (a) only for videos of biological motion, and (b) only when the effector implied by the language (e.g., the hand) matched the videos. These findings are signatures of the MNS. PMID:24381553

Storm Motion Tracking Over The Arno River Basin Through Multiscale Radar Reflectivity Classification and Correlation

NASA Astrophysics Data System (ADS)

Facheris, L.; Tanelli, S.; Giuli, D.

A method is presented for analyzing the storm motion through the application of a nowcasting technique based on radar echoes tracking through multiscale correlation. The application of the correlation principle to weather radar image processing - the so called TREC (Tracking Radar Echoes by Correlation) and derived algorithms - is de- scribed in [1] and in references cited therein. The block matching approach exploited there is typical of video compression applications, whose purpose is to remove the temporal correlation between two subsequent frames of a sequence of images. In par- ticular, the wavelet decomposition approach to motion estimation seems particularly suitable for weather radar maps. In fact, block matching is particularly efficient when the images have a sufficient level of contrast. Though this does not hold for original resolution radar maps, it can be easily obtained by changing the resolution level by means of the wavelet decomposition. The technique first proposed in [2] (TREMC - Tracking of Radar Echoes by means of Multiscale Correlation) adopts a multiscale, multiresolution, and partially overlapped, block grid which adapts to the radar reflec- tivity pattern. Multiresolution decomposition is performed through 2D wavelet based filtering. Correlation coefficients are calculated taking after preliminary screening of unreliable data (e.g. those affected by ground clutter or beam shielding), so as to avoid strong undesired motion estimation biases due to the presence of stationary features. Such features are detected by a previous analysis carried out as discussed in [2]. In this paper, motion fields obtained by analyzing precipitation events over the Arno river basin are compared to the related Doppler velocity fields in order to identify growth and decay areas and orographic effects. Data presented have been collected by the weather radar station POLAR 55C sited in Montagnana (Firenze-Italy), a polarimetric C-band system providing absolute and differential reflectivity maps, mean Doppler velocity and Doppler spread maps with a resolution of 125/250 m [3]. [1] Li L. Schmid W. and Joss J., Nowcasting of motion and growth of precipitation with radar over a complex orography Journal of Applied Meteorology, vol. 34, pp. 1286-1300, 1995. [2] L.Facheris, S. Tanelli, F. Argenti, D.Giuli, SWavelet Applica- & cedil;tions to Multiparameter Weather Radar AnalysisT, to be published on SInformation & cedil;Processing for Remote SensingT, Prof. C.H. Chen Ed. for World Scientific Publish- 1 ing Co., pagg. 187-207, 1999 [3] Scarchilli G. Gorgucci E. Giuli D. Facheris L. Freni A. and Vezzani G., Arno Project: Radar System and objectives., Proceedings 25th In- ternational Conference on Radar Meteorology, Paris, France, 24-28 June 1991, pp. 805-808 2

Slip-spring model of entangled rod-coil block copolymers

NASA Astrophysics Data System (ADS)

Wang, Muzhou; Likhtman, Alexei E.; Olsen, Bradley D.

2015-03-01

Understanding the dynamics of rod-coil block copolymers is important for optimal design of functional nanostructured materials for organic electronics and biomaterials. Recently, we proposed a reptation theory of entangled rod-coil block copolymers, predicting the relaxation mechanisms of activated reptation and arm retraction that slow rod-coil dynamics relative to coil and rod homopolymers, respectively. In this work, we introduce a coarse-grained slip-spring model of rod-coil block copolymers to further explore these mechanisms. First, parameters of the coarse-grained model are tuned to match previous molecular dynamics simulation results for coils, rods, and block copolymers. For activated reptation, rod-coil copolymers are shown to disfavor configurations where the rod occupies curved portions of the entanglement tube of randomly varying curvature created by the coil ends. The effect of these barriers on diffusion is quantitatively captured by considering one-dimensional motion along an entanglement tube with a rough free energy potential. Finally, we analyze the crossover between the two mechanisms. The resulting dynamics from both mechanisms acting in combination is faster than from each one individually.

Block matching and Wiener filtering approach to optical turbulence mitigation and its application to simulated and real imagery with quantitative error analysis

NASA Astrophysics Data System (ADS)

Hardie, Russell C.; Rucci, Michael A.; Dapore, Alexander J.; Karch, Barry K.

2017-07-01

We present a block-matching and Wiener filtering approach to atmospheric turbulence mitigation for long-range imaging of extended scenes. We evaluate the proposed method, along with some benchmark methods, using simulated and real-image sequences. The simulated data are generated with a simulation tool developed by one of the authors. These data provide objective truth and allow for quantitative error analysis. The proposed turbulence mitigation method takes a sequence of short-exposure frames of a static scene and outputs a single restored image. A block-matching registration algorithm is used to provide geometric correction for each of the individual input frames. The registered frames are then averaged, and the average image is processed with a Wiener filter to provide deconvolution. An important aspect of the proposed method lies in how we model the degradation point spread function (PSF) for the purposes of Wiener filtering. We use a parametric model that takes into account the level of geometric correction achieved during image registration. This is unlike any method we are aware of in the literature. By matching the PSF to the level of registration in this way, the Wiener filter is able to fully exploit the reduced blurring achieved by registration. We also describe a method for estimating the atmospheric coherence diameter (or Fried parameter) from the estimated motion vectors. We provide a detailed performance analysis that illustrates how the key tuning parameters impact system performance. The proposed method is relatively simple computationally, yet it has excellent performance in comparison with state-of-the-art benchmark methods in our study.

Microplate model for the present-day deformation of Tibet

USGS Publications Warehouse

Thatcher, W.

2007-01-01

Site velocities from 349 Global Positioning System (GPS) stations are used to construct an 11-element quasi-rigid block model of the Tibetan Plateau and its surroundings. Rigid rotations of five major blocks are well determined, and average translation velocities of six smaller blocks can be constrained. Where data are well distributed the velocity field can be explained well by rigid block motion and fault slip across block boundaries. Residual misfits average 1.6 mm/yr compared to typical one standard deviation velocity uncertainties of 1.3 mm/yr. Any residual internal straining of the blocks is small and heterogeneous. However, residual substructure might well represent currently unresolved motions of smaller blocks. Although any smaller blocks must move at nearly the same rate as the larger blocks within which they lie, undetected relative motions between them could be significant, particularly where there are gaps in GPS coverage. Predicted relative motions between major blocks agree with the observed sense of slip and along-strike partitioning of motion across major faults. However, predicted slip rates across Tibet's major strike-slip faults are low, only 5-12 mm/yr, a factor of 2-3 smaller than most rates estimated from fault offset features dated by radiometric methods as ???2000 to ???100,000 year old. Previous work has suggested that both GPS data and low fault slip rates are incompatible with rigid block motions of Tibet. The results reported here overcome these objections.

Rotation of vertically oriented objects during earthquakes

NASA Astrophysics Data System (ADS)

Hinzen, Klaus-G.

2012-10-01

Vertically oriented objects, such as tombstones, monuments, columns, and stone lanterns, are often observed to shift and rotate during earthquake ground motion. Such observations are usually limited to the mesoseismal zone. Whether near-field rotational ground motion components are necessary in addition to pure translational movements to explain the observed rotations is an open question. We summarize rotation data from seven earthquakes between 1925 and 2009 and perform analog and numeric rotation testing with vertically oriented objects. The free-rocking motion of a marble block on a sliding table is disturbed by a pulse in the direction orthogonal to the rocking motion. When the impulse is sufficiently strong and occurs at the `right' moment, it induces significant rotation of the block. Numeric experiments of a free-rocking block show that the initiation of vertical block rotation by a cycloidal acceleration pulse applied orthogonal to the rocking axis depends on the amplitude of the pulse and its phase relation to the rocking cycle. Rotation occurs when the pulse acceleration exceeds the threshold necessary to provoke rocking of a resting block, and the rocking block approaches its equilibrium position. Experiments with blocks subjected to full 3D strong motion signals measured during the 2009 L'Aquila earthquake confirm the observations from the tests with analytic ground motions. Significant differences in the rotational behavior of a monolithic block and two stacked blocks exist.

A complete system for head tracking using motion-based particle filter and randomly perturbed active contour

NASA Astrophysics Data System (ADS)

Bouaynaya, N.; Schonfeld, Dan

2005-03-01

Many real world applications in computer and multimedia such as augmented reality and environmental imaging require an elastic accurate contour around a tracked object. In the first part of the paper we introduce a novel tracking algorithm that combines a motion estimation technique with the Bayesian Importance Sampling framework. We use Adaptive Block Matching (ABM) as the motion estimation technique. We construct the proposal density from the estimated motion vector. The resulting algorithm requires a small number of particles for efficient tracking. The tracking is adaptive to different categories of motion even with a poor a priori knowledge of the system dynamics. Particulary off-line learning is not needed. A parametric representation of the object is used for tracking purposes. In the second part of the paper, we refine the tracking output from a parametric sample to an elastic contour around the object. We use a 1D active contour model based on a dynamic programming scheme to refine the output of the tracker. To improve the convergence of the active contour, we perform the optimization over a set of randomly perturbed initial conditions. Our experiments are applied to head tracking. We report promising tracking results in complex environments.

Sprint Start Kinetics of Amputee and Non-Amputee Sprinters

PubMed Central

Willwacher, Steffen; Herrmann, Volker; Heinrich, Kai; Funken, Johannes; Strutzenberger, Gerda; Goldmann, Jan-Peter; Braunstein, Björn; Brazil, Adam; Irwin, Gareth; Potthast, Wolfgang; Brüggemann, Gert-Peter

2016-01-01

The purpose of this study was to explore the relationship between the forces applied to the starting blocks and the start performances (SPs) of amputee sprinters (ASs) and non-amputee sprinters (NASs). SPs of 154 male and female NASs (100-m personal records [PRs], 9.58–14.00 s) and 7 male ASs (3 unilateral above knee, 3 unilateral below knee, 1 bilateral below knee; 100 m PRs, 11.70–12.70 s) with running specific prostheses (RSPs) were analysed during full-effort sprint starts using instrumented starting blocks that measured the applied forces in 3D. Using the NAS dataset and a combination of factor analysis and multiple regression techniques, we explored the relationship between force characteristics and SP (quantified by normalized average horizontal block power). Start kinetics were subsequently compared between ASs and NASs who were matched based on their absolute 100 m PR and their 100 m PR relative to the world record in their starting class. In NASs, 86% of the variance in SP was shared with five latent factors on which measured parameters related to force application to the rear and front blocks and the respective push-off directions in the sagittal plane of motion were loaded. Mediolateral force application had little influence on SP. The SP of ASs was significantly reduced compared to that of NASs matched on the basis of relative 100-m PR (−33.8%; d = 2.11, p < 0.001), while a non-significant performance reduction was observed when absolute 100-m PRs were used (−17.7%; d = 0.79, p = 0.09). These results are at least partially explained by the fact that force application to the rear block was clearly impaired in the affected legs of ASs. PMID:27846241

Sprint Start Kinetics of Amputee and Non-Amputee Sprinters.

PubMed

Willwacher, Steffen; Herrmann, Volker; Heinrich, Kai; Funken, Johannes; Strutzenberger, Gerda; Goldmann, Jan-Peter; Braunstein, Björn; Brazil, Adam; Irwin, Gareth; Potthast, Wolfgang; Brüggemann, Gert-Peter

2016-01-01

The purpose of this study was to explore the relationship between the forces applied to the starting blocks and the start performances (SPs) of amputee sprinters (ASs) and non-amputee sprinters (NASs). SPs of 154 male and female NASs (100-m personal records [PRs], 9.58-14.00 s) and 7 male ASs (3 unilateral above knee, 3 unilateral below knee, 1 bilateral below knee; 100 m PRs, 11.70-12.70 s) with running specific prostheses (RSPs) were analysed during full-effort sprint starts using instrumented starting blocks that measured the applied forces in 3D. Using the NAS dataset and a combination of factor analysis and multiple regression techniques, we explored the relationship between force characteristics and SP (quantified by normalized average horizontal block power). Start kinetics were subsequently compared between ASs and NASs who were matched based on their absolute 100 m PR and their 100 m PR relative to the world record in their starting class. In NASs, 86% of the variance in SP was shared with five latent factors on which measured parameters related to force application to the rear and front blocks and the respective push-off directions in the sagittal plane of motion were loaded. Mediolateral force application had little influence on SP. The SP of ASs was significantly reduced compared to that of NASs matched on the basis of relative 100-m PR (-33.8%; d = 2.11, p < 0.001), while a non-significant performance reduction was observed when absolute 100-m PRs were used (-17.7%; d = 0.79, p = 0.09). These results are at least partially explained by the fact that force application to the rear block was clearly impaired in the affected legs of ASs.

Efficient low-bit-rate adaptive mesh-based motion compensation technique

NASA Astrophysics Data System (ADS)

Mahmoud, Hanan A.; Bayoumi, Magdy A.

2001-08-01

This paper proposes a two-stage global motion estimation method using a novel quadtree block-based motion estimation technique and an active mesh model. In the first stage, motion parameters are estimated by fitting block-based motion vectors computed using a new efficient quadtree technique, that divides a frame into equilateral triangle blocks using the quad-tree structure. Arbitrary partition shapes are achieved by allowing 4-to-1, 3-to-1 and 2-1 merge/combine of sibling blocks having the same motion vector . In the second stage, the mesh is constructed using an adaptive triangulation procedure that places more triangles over areas with high motion content, these areas are estimated during the first stage. finally the motion compensation is achieved by using a novel algorithm that is carried by both the encoder and the decoder to determine the optimal triangulation of the resultant partitions followed by affine mapping at the encoder. Computer simulation results show that the proposed method gives better performance that the conventional ones in terms of the peak signal-to-noise ration (PSNR) and the compression ratio (CR).

Caffeine ingestion changes time-motion and technical-tactical aspects in simulated boxing matches: A randomized double-blind PLA-controlled crossover study.

PubMed

Coswig, Victor Silveira; Gentil, Paulo; Irigon, Francine; Del Vecchio, Fabrício Boscolo

2018-05-08

The number of offensive actions and glycolytic energy in combat sports both increase with caffeine (CAF) ingestion. In addition, the effects of CAF on technical-tactical and time-motion analysis and physiological parameters in boxing are unknown. This study aimed to investigate the effects of CAF ingestion on physiological parameters and the notational analysis of boxing matches. Ten male boxers were recruited; the participants ingested 6 mg kg -1 BM of CAF or placebo (PLA) 30 min prior to the match in a crossover design. Heart rate (HR) and rate of perceived exertion (RPE) were collected before and after each of three 2 min rounds, interspersed by 1-min recovery; the matches were recorded for notational analysis. A two-way ANOVA for repeated measures was used for the physiological variables, and a three-way ANOVA with repeated measures was used for technical-tactical and time-motion variables. Statistical differences were found for HR and RPE between rounds (F (6, 54)  = 131.3, p = .001; [Formula: see text] = 0.93 and F (2, 18)  = 40.6, p = .001; [Formula: see text] = 0.81, respectively) but not between conditions (F (1, 9)  = 0.46; p = .51; [Formula: see text] = 0.05 and F (1, 9)  = 0.02, p = .89; [Formula: see text] = 0.002, respectively). The CAF condition induced a greater duration of interaction blocks (CAF = 6.5 ± 1.8 s; PLA = 4.4 ± 0.9 s; p = .01). Effort:pause ratio was 4.4 s:8.7 s (approx. 1:2) for PLA and 6.5 s:9.4 s (1:1.44) for CAF, which were significantly different (p < .05). In conclusion, 6 mg kg -1 BM of CAF prior to simulated boxing matches induces a greater duration of high-intensity actions, with no effects on internal load markers.

A fast hybrid algorithm combining regularized motion tracking and predictive search for reducing the occurrence of large displacement errors.

PubMed

Jiang, Jingfeng; Hall, Timothy J

2011-04-01

A hybrid approach that inherits both the robustness of the regularized motion tracking approach and the efficiency of the predictive search approach is reported. The basic idea is to use regularized speckle tracking to obtain high-quality seeds in an explorative search that can be used in the subsequent intelligent predictive search. The performance of the hybrid speckle-tracking algorithm was compared with three published speckle-tracking methods using in vivo breast lesion data. We found that the hybrid algorithm provided higher displacement quality metric values, lower root mean squared errors compared with a locally smoothed displacement field, and higher improvement ratios compared with the classic block-matching algorithm. On the basis of these comparisons, we concluded that the hybrid method can further enhance the accuracy of speckle tracking compared with its real-time counterparts, at the expense of slightly higher computational demands. © 2011 IEEE

Detecting dominant motion patterns in crowds of pedestrians

NASA Astrophysics Data System (ADS)

Saqib, Muhammad; Khan, Sultan Daud; Blumenstein, Michael

2017-02-01

As the population of the world increases, urbanization generates crowding situations which poses challenges to public safety and security. Manual analysis of crowded situations is a tedious job and usually prone to errors. In this paper, we propose a novel technique of crowd analysis, the aim of which is to detect different dominant motion patterns in real-time videos. A motion field is generated by computing the dense optical flow. The motion field is then divided into blocks. For each block, we adopt an Intra-clustering algorithm for detecting different flows within the block. Later on, we employ Inter-clustering for clustering the flow vectors among different blocks. We evaluate the performance of our approach on different real-time videos. The experimental results show that our proposed method is capable of detecting distinct motion patterns in crowded videos. Moreover, our algorithm outperforms state-of-the-art methods.

Nonrigid Image Registration in Digital Subtraction Angiography Using Multilevel B-Spline

PubMed Central

2013-01-01

We address the problem of motion artifact reduction in digital subtraction angiography (DSA) using image registration techniques. Most of registration algorithms proposed for application in DSA, have been designed for peripheral and cerebral angiography images in which we mainly deal with global rigid motions. These algorithms did not yield good results when applied to coronary angiography images because of complex nonrigid motions that exist in this type of angiography images. Multiresolution and iterative algorithms are proposed to cope with this problem, but these algorithms are associated with high computational cost which makes them not acceptable for real-time clinical applications. In this paper we propose a nonrigid image registration algorithm for coronary angiography images that is significantly faster than multiresolution and iterative blocking methods and outperforms competing algorithms evaluated on the same data sets. This algorithm is based on a sparse set of matched feature point pairs and the elastic registration is performed by means of multilevel B-spline image warping. Experimental results with several clinical data sets demonstrate the effectiveness of our approach. PMID:23971026

Example-Based Automatic Music-Driven Conventional Dance Motion Synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Songhua; Fan, Rukun; Geng, Weidong

We introduce a novel method for synthesizing dance motions that follow the emotions and contents of a piece of music. Our method employs a learning-based approach to model the music to motion mapping relationship embodied in example dance motions along with those motions' accompanying background music. A key step in our method is to train a music to motion matching quality rating function through learning the music to motion mapping relationship exhibited in synchronized music and dance motion data, which were captured from professional human dance performance. To generate an optimal sequence of dance motion segments to match with amore » piece of music, we introduce a constraint-based dynamic programming procedure. This procedure considers both music to motion matching quality and visual smoothness of a resultant dance motion sequence. We also introduce a two-way evaluation strategy, coupled with a GPU-based implementation, through which we can execute the dynamic programming process in parallel, resulting in significant speedup. To evaluate the effectiveness of our method, we quantitatively compare the dance motions synthesized by our method with motion synthesis results by several peer methods using the motions captured from professional human dancers' performance as the gold standard. We also conducted several medium-scale user studies to explore how perceptually our dance motion synthesis method can outperform existing methods in synthesizing dance motions to match with a piece of music. These user studies produced very positive results on our music-driven dance motion synthesis experiments for several Asian dance genres, confirming the advantages of our method.« less

The successively temporal error concealment algorithm using error-adaptive block matching principle

NASA Astrophysics Data System (ADS)

Lee, Yu-Hsuan; Wu, Tsai-Hsing; Chen, Chao-Chyun

2014-09-01

Generally, the temporal error concealment (TEC) adopts the blocks around the corrupted block (CB) as the search pattern to find the best-match block in previous frame. Once the CB is recovered, it is referred to as the recovered block (RB). Although RB can be the search pattern to find the best-match block of another CB, RB is not the same as its original block (OB). The error between the RB and its OB limits the performance of TEC. The successively temporal error concealment (STEC) algorithm is proposed to alleviate this error. The STEC procedure consists of tier-1 and tier-2. The tier-1 divides a corrupted macroblock into four corrupted 8 × 8 blocks and generates a recovering order for them. The corrupted 8 × 8 block with the first place of recovering order is recovered in tier-1, and remaining 8 × 8 CBs are recovered in tier-2 along the recovering order. In tier-2, the error-adaptive block matching principle (EA-BMP) is proposed for the RB as the search pattern to recover remaining corrupted 8 × 8 blocks. The proposed STEC outperforms sophisticated TEC algorithms on average PSNR by 0.3 dB on the packet error rate of 20% at least.

Motion compensated shape error concealment.

PubMed

Schuster, Guido M; Katsaggelos, Aggelos K

2006-02-01

The introduction of Video Objects (VOs) is one of the innovations of MPEG-4. The alpha-plane of a VO defines its shape at a given instance in time and hence determines the boundary of its texture. In packet-based networks, shape, motion, and texture are subject to loss. While there has been considerable attention paid to the concealment of texture and motion errors, little has been done in the field of shape error concealment. In this paper we propose a post-processing shape error concealment technique that uses the motion compensated boundary information of the previously received alpha-plane. The proposed approach is based on matching received boundary segments in the current frame to the boundary in the previous frame. This matching is achieved by finding a maximally smooth motion vector field. After the current boundary segments are matched to the previous boundary, the missing boundary pieces are reconstructed by motion compensation. Experimental results demonstrating the performance of the proposed motion compensated shape error concealment method, and comparing it with the previously proposed weighted side matching method are presented.

Video compression of coronary angiograms based on discrete wavelet transform with block classification.

PubMed

Ho, B T; Tsai, M J; Wei, J; Ma, M; Saipetch, P

1996-01-01

A new method of video compression for angiographic images has been developed to achieve high compression ratio (~20:1) while eliminating block artifacts which leads to loss of diagnostic accuracy. This method adopts motion picture experts group's (MPEGs) motion compensated prediction to takes advantage of frame to frame correlation. However, in contrast to MPEG, the error images arising from mismatches in the motion estimation are encoded by discrete wavelet transform (DWT) rather than block discrete cosine transform (DCT). Furthermore, the authors developed a classification scheme which label each block in an image as intra, error, or background type and encode it accordingly. This hybrid coding can significantly improve the compression efficiency in certain eases. This method can be generalized for any dynamic image sequences applications sensitive to block artifacts.

Crustal block motion model and interplate coupling along Ecuador-Colombia trench based on GNSS observation network

NASA Astrophysics Data System (ADS)

Ito, T.; Mora-Páez, H.; Peláez-Gaviria, J. R.; Kimura, H.; Sagiya, T.

2017-12-01

IntroductionEcuador-Colombia trench is located at the boundary between South-America plate, Nazca Plate and Caribrian plate. This region is very complexes such as subducting Caribrian plate and Nazca plate, and collision between Panama and northern part of the Andes mountains. The previous large earthquakes occurred along the subducting boundary of Nazca plate, such as 1906 (M8.8) and 1979 (M8.2). And also, earthquakes occurred inland, too. So, it is important to evaluate earthquake potentials for preparing huge damage due to large earthquake in near future. GNSS observation In the last decade, the GNSS observation was established in Columbia. The GNSS observation is called by GEORED, which is operated by servicing Geologico Colomiano. The purpose of GEORED is research of crustal deformation. The number of GNSS site of GEORED is consist of 60 continuous GNSS observation site at 2017 (Mora et al., 2017). The sampling interval of almost GNSS site is 30 seconds. These GNSS data were processed by PPP processing using GIPSY-OASYS II software. GEORED can obtain the detailed crustal deformation map in whole Colombia. In addition, we use 100 GNSS data at Ecuador-Peru region (Nocquet et al. 2014). Method We developed a crustal block movements model based on crustal deformation derived from GNSS observation. Our model considers to the block motion with pole location and angular velocity and the interplate coupling between each block boundaries, including subduction between the South-American plate and the Nazca plate. And also, our approach of estimation of crustal block motion and coefficient of interplate coupling are based on MCMC method. The estimated each parameter is obtained probably density function (PDF). Result We tested 11 crustal block models based on geological data, such as active fault trace at surface. The optimal number of crustal blocks is 11 for based on geological and geodetic data using AIC. We use optimal block motion model. And also, we estimate interplate coupling along the plate interface and rigid block motion. We can evaluate to contribution of elastic deformation and rigid motion. In result, weak plate coupling was found northern part of 3 degree in latitude. Almost crustal deformation are explained by rigid block motion.

A 2d Block Model For Landslide Simulation: An Application To The 1963 Vajont Case

NASA Astrophysics Data System (ADS)

Tinti, S.; Zaniboni, F.; Manucci, A.; Bortolucci, E.

A 2D block model to study the motion of a sliding mass is presented. The slide is par- titioned into a matrix of blocks the basis of which are quadrilaterals. The blocks move on a specified sliding surface and follow a trajectory that is computed by the model. The forces acting on the blocks are gravity, basal friction, buoyancy in case of under- water motion, and interaction with neighbouring blocks. At any time step, the position of the blocks on the sliding surface is determined in curvilinear (local) co-ordinates by computing the position of the vertices of the quadrilaterals and the position of the block centre of mass. Mathematically, the topology of the system is invariant during the motion, which means that the number of blocks is constant and that each block has always the same neighbours. Physically, this means that blocks are allowed to change form, but not to penetrate into each other, not to coalesce, not to split. The change of form is compensated by the change of height, under the computational assumption that the block volume is constant during motion: consequently lateral expansion or contraction yield respectively height reduction or increment of the blocks. This model is superior to the analogous 1D model where the mass is partitioned into a chain of interacting blocks. 1D models require the a-priori specification of the sliding path, that is of the trajectory of the blocks, which the 2D block model supplies as one of its output. In continuation of previous studies on the catastrophic slide of Vajont that occurred in 1963 in northern Italy and caused more than 2000 victims, the 2D block model has been applied to the Vajont case. The results are compared to the outcome of the 1D model, and more importantly to the observational data concerning the deposit position and morphology. The agreement between simulation and data is found to be quite good.

Active Tectonics of the Far North Pacific Observed with GPS

NASA Astrophysics Data System (ADS)

Elliott, J.; Freymueller, J. T.; Jiang, Y.; Leonard, L. J.; Hyndman, R. D.; Mazzotti, S.

2017-12-01

The idea that the tectonics of the northeastern Pacific is defined by relatively discrete deformation along the boundary between the Pacific and North American plates has given way to a more complex picture of broad plate boundary zones and distributed deformation. This is due in large part to the Plate Boundary Observatory and several focused GPS studies, which have greatly increased the density of high-quality GPS data throughout the region. We will present an updated GPS velocity field in a consistent reference frame as well as a new, integrated block model that sheds light on regional tectonics and provides improved estimates of motion along faults and their potential seismic hazard. Crustal motions in southern Alaska are strongly influenced by the collision and flat-slab subduction of the Yakutat block along the central Gulf of Alaska margin. In the area nearest to the collisional front, small blocks showing evidence of internal deformation are required. East of the front, block motions show clockwise rotation into the Canadian Cordillera while west of the front there are counterclockwise rotations that extend along the Alaska forearc, suggesting crustal extrusion. Farther from the convergent margin, the crust appears to move as rigid blocks, with uniform motion over large areas. In western Alaska, block motions show a southwesterly rotation into the Bering Sea. Arctic Alaska displays southeasterly motions that gradually transition into easterly motion in Canada. Much of the southeastern Alaska panhandle and coastal British Columbia exhibit northwesterly motions. Although the relative plate motions are mainly accommodated along major faults systems, including the Fairweather-Queen Charlotte transform system, the St. Elias fold-and-thrust belt, the Denali-Totschunda system, and the Alaska-Aleutian subduction zone, a number of other faults accommodate lesser but still significant amounts of motion in the model. These faults include the eastern Denali/Duke River system, the Castle Mountain fault, the western Denali fault, the Kaltag fault, and the Kobuk fault. Based on the expanded GPS data set, locked or partially locked sections of the Alaska subduction zone may extend as far north and east as the eastern Alaska Range.

The Statistical Power of the Cluster Randomized Block Design with Matched Pairs--A Simulation Study

ERIC Educational Resources Information Center

Dong, Nianbo; Lipsey, Mark

2010-01-01

This study uses simulation techniques to examine the statistical power of the group- randomized design and the matched-pair (MP) randomized block design under various parameter combinations. Both nearest neighbor matching and random matching are used for the MP design. The power of each design for any parameter combination was calculated from…

Color Image Classification Using Block Matching and Learning

NASA Astrophysics Data System (ADS)

Kondo, Kazuki; Hotta, Seiji

In this paper, we propose block matching and learning for color image classification. In our method, training images are partitioned into small blocks. Given a test image, it is also partitioned into small blocks, and mean-blocks corresponding to each test block are calculated with neighbor training blocks. Our method classifies a test image into the class that has the shortest total sum of distances between mean blocks and test ones. We also propose a learning method for reducing memory requirement. Experimental results show that our classification outperforms other classifiers such as support vector machine with bag of keypoints.

Computing global minimizers to a constrained B-spline image registration problem from optimal l1 perturbations to block match data

PubMed Central

Castillo, Edward; Castillo, Richard; Fuentes, David; Guerrero, Thomas

2014-01-01

Purpose: Block matching is a well-known strategy for estimating corresponding voxel locations between a pair of images according to an image similarity metric. Though robust to issues such as image noise and large magnitude voxel displacements, the estimated point matches are not guaranteed to be spatially accurate. However, the underlying optimization problem solved by the block matching procedure is similar in structure to the class of optimization problem associated with B-spline based registration methods. By exploiting this relationship, the authors derive a numerical method for computing a global minimizer to a constrained B-spline registration problem that incorporates the robustness of block matching with the global smoothness properties inherent to B-spline parameterization. Methods: The method reformulates the traditional B-spline registration problem as a basis pursuit problem describing the minimal l1-perturbation to block match pairs required to produce a B-spline fitting error within a given tolerance. The sparsity pattern of the optimal perturbation then defines a voxel point cloud subset on which the B-spline fit is a global minimizer to a constrained variant of the B-spline registration problem. As opposed to traditional B-spline algorithms, the optimization step involving the actual image data is addressed by block matching. Results: The performance of the method is measured in terms of spatial accuracy using ten inhale/exhale thoracic CT image pairs (available for download at www.dir-lab.com) obtained from the COPDgene dataset and corresponding sets of expert-determined landmark point pairs. The results of the validation procedure demonstrate that the method can achieve a high spatial accuracy on a significantly complex image set. Conclusions: The proposed methodology is demonstrated to achieve a high spatial accuracy and is generalizable in that in can employ any displacement field parameterization described as a least squares fit to block match generated estimates. Thus, the framework allows for a wide range of image similarity block match metric and physical modeling combinations. PMID:24694135

Precise Aperture-Dependent Motion Compensation with Frequency Domain Fast Back-Projection Algorithm.

PubMed

Zhang, Man; Wang, Guanyong; Zhang, Lei

2017-10-26

Precise azimuth-variant motion compensation (MOCO) is an essential and difficult task for high-resolution synthetic aperture radar (SAR) imagery. In conventional post-filtering approaches, residual azimuth-variant motion errors are generally compensated through a set of spatial post-filters, where the coarse-focused image is segmented into overlapped blocks concerning the azimuth-dependent residual errors. However, image domain post-filtering approaches, such as precise topography- and aperture-dependent motion compensation algorithm (PTA), have difficulty of robustness in declining, when strong motion errors are involved in the coarse-focused image. In this case, in order to capture the complete motion blurring function within each image block, both the block size and the overlapped part need necessary extension leading to degeneration of efficiency and robustness inevitably. Herein, a frequency domain fast back-projection algorithm (FDFBPA) is introduced to deal with strong azimuth-variant motion errors. FDFBPA disposes of the azimuth-variant motion errors based on a precise azimuth spectrum expression in the azimuth wavenumber domain. First, a wavenumber domain sub-aperture processing strategy is introduced to accelerate computation. After that, the azimuth wavenumber spectrum is partitioned into a set of wavenumber blocks, and each block is formed into a sub-aperture coarse resolution image via the back-projection integral. Then, the sub-aperture images are straightforwardly fused together in azimuth wavenumber domain to obtain a full resolution image. Moreover, chirp-Z transform (CZT) is also introduced to implement the sub-aperture back-projection integral, increasing the efficiency of the algorithm. By disusing the image domain post-filtering strategy, robustness of the proposed algorithm is improved. Both simulation and real-measured data experiments demonstrate the effectiveness and superiority of the proposal.

Serotonergic mechanisms in emesis

NASA Technical Reports Server (NTRS)

Lucot, J. B.; Crampton, G. H.

1988-01-01

The observation that the cerebrospinal fluid of cats which are susceptible to motion sickness contained lower baseline levels of 5-hydroxyindoleacetic acid, among other constituents, led to the hypothesis that serotonin inhibits emesis. The hypothesis was tested by administration of the serotonin-1A agonists buspirone and 8-OH-DPAT before motion testing in cats susceptible to motion sickness. Both drugs blocked motion sickness in a dose-dependent fashion. To determine if these drugs blocked emesis elicited by other stimuli, they were administered before subcutaneous administration of the alpha-2 noradrenergic agonist, xylazine. Both drugs also blocked xylazine-induced emesis. It was concluded that the stimulation of serotonin-1A receptors inhibits emesis elicited by the two stimuli and that this mechanism may exert a general antiemetic effect.

Gallium arsenide processing elements for motion estimation full-search algorithm

NASA Astrophysics Data System (ADS)

Lopez, Jose F.; Cortes, P.; Lopez, S.; Sarmiento, Roberto

2001-11-01

The Block-Matching motion estimation algorithm (BMA) is the most popular method for motion-compensated coding of image sequence. Among the several possible searching methods to compute this algorithm, the full-search BMA (FBMA) has obtained great interest from the scientific community due to its regularity, optimal solution and low control overhead which simplifies its VLSI realization. On the other hand, its main drawback is the demand of an enormous amount of computation. There are different ways of overcoming this factor, being the use of advanced technologies, such as Gallium Arsenide (GaAs), the one adopted in this article together with different techniques to reduce area overhead. By exploiting GaAs properties, improvements can be obtained in the implementation of feasible systems for real time video compression architectures. Different primitives used in the implementation of processing elements (PE) for a FBMA scheme are presented. As a result, Pes running at 270 MHz have been developed in order to study its functionality and performance. From these results, an implementation for MPEG applications is proposed, leading to an architecture running at 145 MHz with a power dissipation of 3.48 W and an area of 11.5 mm2.

2-D Myocardial Deformation Imaging Based on RF-Based Nonrigid Image Registration.

PubMed

Chakraborty, Bidisha; Liu, Zhi; Heyde, Brecht; Luo, Jianwen; D'hooge, Jan

2018-06-01

Myocardial deformation imaging is a well-established echocardiographic technique for the assessment of myocardial function. Although some solutions make use of speckle tracking of the reconstructed B-mode images, others apply block matching (BM) on the underlying radio frequency (RF) data in order to increase sensitivity to small interframe motion and deformation. However, for both approaches, lateral motion estimation remains a challenge due to the relatively poor lateral resolution of the ultrasound image in combination with the lack of phase information in this direction. Hereto, nonrigid image registration (NRIR) of B-mode images has previously been proposed as an attractive solution. However, hereby, the advantages of RF-based tracking were lost. The aim of this paper was, therefore, to develop an NRIR motion estimator adapted to RF data sets. The accuracy of this estimator was quantified using synthetic data and was contrasted against a state-of-the-art BM solution. The results show that RF-based NRIR outperforms BM in terms of tracking accuracy, particularly, as hypothesized, in the lateral direction. Finally, this RF-based NRIR algorithm was applied clinically, illustrating its ability to estimate both in-plane velocity components in vivo.

A Method of Calculating Motion Error in a Linear Motion Bearing Stage

PubMed Central

Khim, Gyungho; Park, Chun Hong; Oh, Jeong Seok

2015-01-01

We report a method of calculating the motion error of a linear motion bearing stage. The transfer function method, which exploits reaction forces of individual bearings, is effective for estimating motion errors; however, it requires the rail-form errors. This is not suitable for a linear motion bearing stage because obtaining the rail-form errors is not straightforward. In the method described here, we use the straightness errors of a bearing block to calculate the reaction forces on the bearing block. The reaction forces were compared with those of the transfer function method. Parallelism errors between two rails were considered, and the motion errors of the linear motion bearing stage were measured and compared with the results of the calculations, revealing good agreement. PMID:25705715

Motion Evaluation for Rehabilitation Training of the Disabled

NASA Astrophysics Data System (ADS)

Kim, Tae-Young; Park, Jun; Lim, Cheol-Su

In this paper, a motion evaluation technique for rehabilitation training is introduced. Motion recognition technologies have been developed for determining matching motions in the training set. However, we need to measure how well and how much of the motion has been followed for training motion evaluation. We employed a Finite State Machine as a framework of motion evaluation. For similarity analysis, we used weighted angular value differences although any template matching algorithm may be used. For robustness under illumination changes, IR LED's and cameras with IR-pass filter were used. Developed technique was successfully used for rehabilitation training of the disabled. Therapists appraised the system as practically useful.

Non-rigid, but not rigid, motion interferes with the processing of structural face information in developmental prosopagnosia.

PubMed

Maguinness, Corrina; Newell, Fiona N

2015-04-01

There is growing evidence to suggest that facial motion is an important cue for face recognition. However, it is poorly understood whether motion is integrated with facial form information or whether it provides an independent cue to identity. To provide further insight into this issue, we compared the effect of motion on face perception in two developmental prosopagnosics and age-matched controls. Participants first learned faces presented dynamically (video), or in a sequence of static images, in which rigid (viewpoint) or non-rigid (expression) changes occurred. Immediately following learning, participants were required to match a static face image to the learned face. Test face images varied by viewpoint (Experiment 1) or expression (Experiment 2) and were learned or novel face images. We found similar performance across prosopagnosics and controls in matching facial identity across changes in viewpoint when the learned face was shown moving in a rigid manner. However, non-rigid motion interfered with face matching across changes in expression in both individuals with prosopagnosia compared to the performance of control participants. In contrast, non-rigid motion did not differentially affect the matching of facial expressions across changes in identity for either prosopagnosics (Experiment 3). Our results suggest that whilst the processing of rigid motion information of a face may be preserved in developmental prosopagnosia, non-rigid motion can specifically interfere with the representation of structural face information. Taken together, these results suggest that both form and motion cues are important in face perception and that these cues are likely integrated in the representation of facial identity. Copyright © 2015 Elsevier Ltd. All rights reserved.

A multistage motion vector processing method for motion-compensated frame interpolation.

PubMed

Huang, Ai- Mei; Nguyen, Truong Q

2008-05-01

In this paper, a novel, low-complexity motion vector processing algorithm at the decoder is proposed for motion-compensated frame interpolation or frame rate up-conversion. We address the problems of having broken edges and deformed structures in an interpolated frame by hierarchically refining motion vectors on different block sizes. Our method explicitly considers the reliability of each received motion vector and has the capability of preserving the structure information. This is achieved by analyzing the distribution of residual energies and effectively merging blocks that have unreliable motion vectors. The motion vector reliability information is also used as a prior knowledge in motion vector refinement using a constrained vector median filter to avoid choosing identical unreliable one. We also propose using chrominance information in our method. Experimental results show that the proposed scheme has better visual quality and is also robust, even in video sequences with complex scenes and fast motion.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, G; Trakul, N; Chang, E

Purpose: To evaluate the reproducibility of target position using moderate voluntary breath-hold during liver stereotactic ablative radiotherapy (SABR). Methods: Two patients who underwent liver SABR on a Varian TrueBeam STx linac were used for this study. Fiducial markers were placed in and around the target in the liver as surrogates for the target position and motion. GTVs were contoured by assessing tumor extent on contrast enhanced CT. The PTV was created from the GTV by adding 2 mm margins to account for the residual motion during breath-holds. A portable biofeedback system was used to facilitate the breath-hold to a reproduciblemore » position. The Varian RPM system was used for gating the linac. Proceeding each treatment, orthogonal kV pairs were taken, and alignment to nearby bony anatomy was performed. Then the breath-hold CBCT was acquired to align the fiducial markers. On-line fluoroscopy was used to fine-tune the breath-hold gating thresholds to correlate with the positions of the fiducial markers. The inter-fraction reproducibility of the target was evaluated by the offsets of the daily breath-hold CBCTs from the paired kV matches as a direct measure of the target position relative to the bony anatomy. The intra-fraction reproducibility of the target position was assessed by the gated window of the RPM marker block for each fraction. Results: The absolute mean offsets between the CBCT and paired kV matches in the vertical, longitudinal, and lateral directions were 0.06 cm, 0.10 cm, and 0.06 cm for patient 1, and 0.37 cm, 0.62 cm, and 0.09 cm for patient 2. The gated window of the RPM marker block for the breath-hold for each fraction was within 0.63 ± 0.16 cm and 0.59 ± 0.12 cm for patients 1 and 2, respectively. Conclusion: Moderate voluntary breath-hold showed good inter- and intra-fraction reproducibility of target position during liver SABR.« less

SOGRA - Supporting Optimized GNSS Research in Africa

DTIC Science & Technology

2014-12-08

velocities of the tectonic blocks in Africa, namely around the East African Rift. Figure 3 shows the recent results obtained for the relative...motion with respect to the neighboring tectonic blocks: (red) NUBI wrt SMLA; (white) NUBI and SMLA wrt VICT; (green) NUBI, SMLA, and VICT wrt RVMA. The...relative motions between the different blocks are small, in the order of few mm/yr for most of the plate boundaries. The major values are obtained in

Active Deformation of the Northern Cordillera Observed with GPS

NASA Astrophysics Data System (ADS)

Elliott, J.; Jiang, Y.; Leonard, L. J.; Hyndman, R. D.; Freymueller, J.; Mazzotti, S.

2017-12-01

The Northern Cordillera, which encompasses western Canada and eastern Alaska, is a complex tectonic puzzle. Past terrane accretions, the present collision of the Yakutat block, large-scale plate motions, and past and present glacier change have created a tectonic landscape that includes a major transform system, most of the highest peaks in North America, and far-flung ongoing distributed deformation. We present an updated GPS velocity field as well as a new integrated tectonic block model for the region. The style of deformation varies through the region. Surrounding the Yakutat collision, the model includes a number of small blocks that indicate rotations to the east, north, and west as material moves away from the collisional front. These small blocks also show evidence of internal deformation. Farther from the collisional front, blocks are larger and appear to behave more rigidly. In the south, northwestward motion resulting in a prominent band of coastal shear extends from Vancouver Island to Glacier Bay. In the Arctic, small southeastward motions in Alaska transition to easterly motion in Canada that extends to the Mackenize Mountains near the Cordillera-craton boundary. A number of faults and fault systems accommodate relative Pacific-North America plate motion in the region, although the significant majority is along the Fairweather-Queen Charlotte transform system and the St. Elias fold-and-thrust belt. Along the Fairweather-Queen Charlotte system, the motion is dominantly dextral with increasing oblique transpression to the south corresponding to a change in margin trend. At the northern end of the transform system, motion is distributed onto multiple faults. Roughly 75% of the Fairweather motion is transferred west into the St. Elias fold-and-thrust belt, which accommodates 30 mm/yr of convergence. The remaining 25% is transferred north towards the dextral Denali-Totschunda system. The eastern Denali fault presently plays a minor role in accommodating relative plate motion, with 2-3 mm/yr of transpression. Based on a sequence of earthquakes in May 2017, this motion may be distributed along multiple fault strands.

The Sundaland Block in SE Asia: A Tectonic Entity Surrounded by Earthquake Hazards

NASA Astrophysics Data System (ADS)

Simons, W. J.; Vigny, C.; Socquet, A.; Ambrosius, B. A.; Naeije, M. C.

2007-12-01

The present-day crustal deformation of SE Asia results from the convergent motion between the Sundaland (SU) block, which covers most of SE Asia, and the adjacent Philippine (PH), Australian (AU) and Indian (IN) tectonic plates in highly active subduction zones. To the north, SU is disconnected from the 'stable' Eurasian (EU) plate by the IN-EU collision which shaped the crustal deformation zones in and around the Himalayan Region. The oblique relative motion between IN/AU and SU caused the 2004 Sumatra-Andaman earthquake/tsunami disaster. A unique (100+ points) GPS velocity field (in ITRF2000 and ITRF2005) that spans the entire SE Asia region, based on a decade of regional measurements (1994-2004), was exploited to resolve Sundaland's motion and boundaries and perform a detailed study of the inter-seismic intraplate deformation [1]. This revealed previously undetected deformation patterns on Java, North Borneo and North Thailand and the much larger subduction deformation zone extending (>600 ~km) from the Sumatra trench towards Peninsular Malaysia and South Thailand. There far-field data implies a ~220~km wide locked trench fault plane below SU at shallow (≤gslant 13°) dip angle and full coupling on the subduction. This matches the very large magnitude of the 26/12/2004 earthquake and the subsequently recorded wide-spread co-seismic deformations throughout the network also provided the first unambiguous evidence of the rupture plane length [2]. The post-seismic motions (both at spatial and temporal scales) of ~50 GPS sites (2005-2006) provide information on the contribution of various mechanisms (aftershocks/afterslip, visco-elastic relaxation and poro- elasticity). These post-seismic motions are very significant in the far-field, e.g. the island of Phuket additionally moved ~1.5 times the initial 2004 and 2005 co-seismic displacements. References: [1] Simons, W.J.F, et al al.(2007), J .Geophys. Res., 112, B06420, doi:10.1029/2005JB003868. [2] Vigny, C. et al.(2005), Nature, 436, 201-206, doi: 10.1038/nature03937

Action verbs are processed differently in metaphorical and literal sentences depending on the semantic match of visual primes

PubMed Central

Troyer, Melissa; Curley, Lauren B.; Miller, Luke E.; Saygin, Ayse P.; Bergen, Benjamin K.

2014-01-01

Language comprehension requires rapid and flexible access to information stored in long-term memory, likely influenced by activation of rich world knowledge and by brain systems that support the processing of sensorimotor content. We hypothesized that while literal language about biological motion might rely on neurocognitive representations of biological motion specific to the details of the actions described, metaphors rely on more generic representations of motion. In a priming and self-paced reading paradigm, participants saw video clips or images of (a) an intact point-light walker or (b) a scrambled control and read sentences containing literal or metaphoric uses of biological motion verbs either closely or distantly related to the depicted action (walking). We predicted that reading times for literal and metaphorical sentences would show differential sensitivity to the match between the verb and the visual prime. In Experiment 1, we observed interactions between the prime type (walker or scrambled video) and the verb type (close or distant match) for both literal and metaphorical sentences, but with strikingly different patterns. We found no difference in the verb region of literal sentences for Close-Match verbs after walker or scrambled motion primes, but Distant-Match verbs were read more quickly following walker primes. For metaphorical sentences, the results were roughly reversed, with Distant-Match verbs being read more slowly following a walker compared to scrambled motion. In Experiment 2, we observed a similar pattern following still image primes, though critical interactions emerged later in the sentence. We interpret these findings as evidence for shared recruitment of cognitive and neural mechanisms for processing visual and verbal biological motion information. Metaphoric language using biological motion verbs may recruit neurocognitive mechanisms similar to those used in processing literal language but be represented in a less-specific way. PMID:25538604

SU-D-17A-07: Development and Evaluation of a Prototype Ultrasonography Respiratory Monitoring System for 4DCT Reconstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, P; Cheng, S; Chao, C

Purpose: Respiratory motion artifacts are commonly seen in the abdominal and thoracic CT images. A Real-time Position Management (RPM) system is integrated with CT simulator using abdominal surface as a surrogate for tracking the patient respiratory motion. The respiratory-correlated four-dimensional computed tomography (4DCT) is then reconstructed by GE advantage software. However, there are still artifacts due to inaccurate respiratory motion detecting and sorting methods. We developed an Ultrasonography Respiration Monitoring (URM) system which can directly monitor diaphragm motion to detect respiratory cycles. We also developed a new 4DCT sorting and motion estimation method to reduce the respiratory motion artifacts. Themore » new 4DCT system was compared with RPM and the GE 4DCT system. Methods: Imaging from a GE CT scanner was simultaneously correlated with both the RPM and URM to detect respiratory motion. A radiation detector, Blackcat GM-10, recorded the X-ray on/off and synchronized with URM. The diaphragm images were acquired with Ultrasonix RP system. The respiratory wave was derived from diaphragm images and synchronized with CT scanner. A more precise peaks and valleys detection tool was developed and compared with RPM. The motion is estimated for the slices which are not in the predefined respiratory phases by using block matching and optical flow method. The CT slices were then sorted into different phases and reconstructed, compared with the images reconstructed from GE Advantage software using respiratory wave produced from RPM system. Results: The 4DCT images were reconstructed for eight patients. The discontinuity at the diaphragm level due to an inaccurate identification of phases by the RPM was significantly improved by URM system. Conclusion: Our URM 4DCT system was evaluated and compared with RPM and GE 4DCT system. The new system is user friendly and able to reduce motion artifacts. It also has the potential to monitor organ motion during therapy.« less

Quality evaluation of motion-compensated edge artifacts in compressed video.

PubMed

Leontaris, Athanasios; Cosman, Pamela C; Reibman, Amy R

2007-04-01

Little attention has been paid to an impairment common in motion-compensated video compression: the addition of high-frequency (HF) energy as motion compensation displaces blocking artifacts off block boundaries. In this paper, we employ an energy-based approach to measure this motion-compensated edge artifact, using both compressed bitstream information and decoded pixels. We evaluate the performance of our proposed metric, along with several blocking and blurring metrics, on compressed video in two ways. First, ordinal scales are evaluated through a series of expectations that a good quality metric should satisfy: the objective evaluation. Then, the best performing metrics are subjectively evaluated. The same subjective data set is finally used to obtain interval scales to gain more insight. Experimental results show that we accurately estimate the percentage of the added HF energy in compressed video.

Illusory motion reveals velocity matching, not foveation, drives smooth pursuit of large objects

PubMed Central

Ma, Zheng; Watamaniuk, Scott N. J.; Heinen, Stephen J.

2017-01-01

When small objects move in a scene, we keep them foveated with smooth pursuit eye movements. Although large objects such as people and animals are common, it is nonetheless unknown how we pursue them since they cannot be foveated. It might be that the brain calculates an object's centroid, and then centers the eyes on it during pursuit as a foveation mechanism might. Alternatively, the brain merely matches the velocity by motion integration. We test these alternatives with an illusory motion stimulus that translates at a speed different from its retinal motion. The stimulus was a Gabor array that translated at a fixed velocity, with component Gabors that drifted with motion consistent or inconsistent with the translation. Velocity matching predicts different pursuit behaviors across drift conditions, while centroid matching predicts no difference. We also tested whether pursuit can segregate and ignore irrelevant local drifts when motion and centroid information are consistent by surrounding the Gabors with solid frames. Finally, observers judged the global translational speed of the Gabors to determine whether smooth pursuit and motion perception share mechanisms. We found that consistent Gabor motion enhanced pursuit gain while inconsistent, opposite motion diminished it, drawing the eyes away from the center of the stimulus and supporting a motion-based pursuit drive. Catch-up saccades tended to counter the position offset, directing the eyes opposite to the deviation caused by the pursuit gain change. Surrounding the Gabors with visible frames canceled both the gain increase and the compensatory saccades. Perceived speed was modulated analogous to pursuit gain. The results suggest that smooth pursuit of large stimuli depends on the magnitude of integrated retinal motion information, not its retinal location, and that the position system might be unnecessary for generating smooth velocity to large pursuit targets. PMID:29090315

A Motion Detection Algorithm Using Local Phase Information

PubMed Central

Lazar, Aurel A.; Ukani, Nikul H.; Zhou, Yiyin

2016-01-01

Previous research demonstrated that global phase alone can be used to faithfully represent visual scenes. Here we provide a reconstruction algorithm by using only local phase information. We also demonstrate that local phase alone can be effectively used to detect local motion. The local phase-based motion detector is akin to models employed to detect motion in biological vision, for example, the Reichardt detector. The local phase-based motion detection algorithm introduced here consists of two building blocks. The first building block measures/evaluates the temporal change of the local phase. The temporal derivative of the local phase is shown to exhibit the structure of a second order Volterra kernel with two normalized inputs. We provide an efficient, FFT-based algorithm for implementing the change of the local phase. The second processing building block implements the detector; it compares the maximum of the Radon transform of the local phase derivative with a chosen threshold. We demonstrate examples of applying the local phase-based motion detection algorithm on several video sequences. We also show how the locally detected motion can be used for segmenting moving objects in video scenes and compare our local phase-based algorithm to segmentation achieved with a widely used optic flow algorithm. PMID:26880882

The Mobile Margin of (Far) North America: GPS Constraints on Active Deformation in Alaska and the Role of the Yakutat Block

NASA Astrophysics Data System (ADS)

Elliott, J.; Freymueller, J. T.; Larsen, C. F.; Motyka, R. J.

2010-12-01

GPS data from southern Alaska and the northern Canadian Cordillera have helped redefine the region’s tectonic landscape. Instead of a comparatively simple interaction between the Pacific and North American plates, with relative motion accommodated on a single boundary fault, we find a margin made up of a number of small blocks and deformation zones with relative motion distributed across a variety of structures. Much of this complexity can be attributed to the Yakutat block, an allochthonous terrane that has been colliding with southern Alaska since the Miocene. We present a GPS-derived tectonic model for the Yakutat block collision and its effects on southern Alaska and eastern Canada. The Yakutat block moves NNW at a rate of 50 mm/a, resulting in ~ 45 mm/a of NW-directed convergence with southern Alaska. Along its eastern edge, the Yakutat block is deforming, represented in our model by two small northwesterly moving blocks outboard of the Fairweather fault. Part of the strain from the collision is transferred east of the Fairweather - Queen Charlotte fault system, causing the region inboard of the Fairweather fault to undergo a distinct clockwise rotation into the northern Canadian Cordillera. Further south, the region directly east of the Queen Charlotte fault displays a much slower clockwise rotation, suggesting that it is at least partially pulled along by the northern block motion. About 5% of the relative motion is transferred even further east, causing small northeasterly motions well into the northern Cordillera. The northwestern edge of the Yakutat block marks the main deformation front between that block and southern Alaska. Multiple narrow, northwesterly moving blocks bounded by N- to NW-dipping thrust faults are required to explain the GPS data between the Malaspina Glacier and the Bagley Ice Valley. These “blocks” may be more aptly termed crustal slivers or deformation zones due to their size and because their bounding faults may sole out into a main thrust instead of cutting through the lithosphere. In contrast with the region to the east, relative convergence is accommodated over a fairly short distance across the St. Elias Mountains. West of the deformation front, the en echelon blocks and faults continue until the vicinity of the Bering Glacier, where the GPS data reveal a rotation towards the north as the tectonic regime transitions from the collision and accretion of the Yakutat block to subduction along the Aleutian Megathrust. North of the Chugach and St. Elias Ranges, the Southern Alaska block rotates counterclockwise.

MR Image Reconstruction Using Block Matching and Adaptive Kernel Methods.

PubMed

Schmidt, Johannes F M; Santelli, Claudio; Kozerke, Sebastian

2016-01-01

An approach to Magnetic Resonance (MR) image reconstruction from undersampled data is proposed. Undersampling artifacts are removed using an iterative thresholding algorithm applied to nonlinearly transformed image block arrays. Each block array is transformed using kernel principal component analysis where the contribution of each image block to the transform depends in a nonlinear fashion on the distance to other image blocks. Elimination of undersampling artifacts is achieved by conventional principal component analysis in the nonlinear transform domain, projection onto the main components and back-mapping into the image domain. Iterative image reconstruction is performed by interleaving the proposed undersampling artifact removal step and gradient updates enforcing consistency with acquired k-space data. The algorithm is evaluated using retrospectively undersampled MR cardiac cine data and compared to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT reconstruction. Evaluation of image quality and root-mean-squared-error (RMSE) reveal improved image reconstruction for up to 8-fold undersampled data with the proposed approach relative to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT. In conclusion, block matching and kernel methods can be used for effective removal of undersampling artifacts in MR image reconstruction and outperform methods using standard compressed sensing and ℓ1-regularized parallel imaging methods.

On the road to somewhere: Brain potentials reflect language effects on motion event perception.

PubMed

Flecken, Monique; Athanasopoulos, Panos; Kuipers, Jan Rouke; Thierry, Guillaume

2015-08-01

Recent studies have identified neural correlates of language effects on perception in static domains of experience such as colour and objects. The generalization of such effects to dynamic domains like motion events remains elusive. Here, we focus on grammatical differences between languages relevant for the description of motion events and their impact on visual scene perception. Two groups of native speakers of German or English were presented with animated videos featuring a dot travelling along a trajectory towards a geometrical shape (endpoint). English is a language with grammatical aspect in which attention is drawn to trajectory and endpoint of motion events equally. German, in contrast, is a non-aspect language which highlights endpoints. We tested the comparative perceptual saliency of trajectory and endpoint of motion events by presenting motion event animations (primes) followed by a picture symbolising the event (target): In 75% of trials, the animation was followed by a mismatching picture (both trajectory and endpoint were different); in 10% of trials, only the trajectory depicted in the picture matched the prime; in 10% of trials, only the endpoint matched the prime; and in 5% of trials both trajectory and endpoint were matching, which was the condition requiring a response from the participant. In Experiment 1 we recorded event-related brain potentials elicited by the picture in native speakers of German and native speakers of English. German participants exhibited a larger P3 wave in the endpoint match than the trajectory match condition, whereas English speakers showed no P3 amplitude difference between conditions. In Experiment 2 participants performed a behavioural motion matching task using the same stimuli as those used in Experiment 1. German and English participants did not differ in response times showing that motion event verbalisation cannot readily account for the difference in P3 amplitude found in the first experiment. We argue that, even in a non-verbal context, the grammatical properties of the native language and associated sentence-level patterns of event encoding influence motion event perception, such that attention is automatically drawn towards aspects highlighted by the grammar. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Deformation Styles Along the Southern Alaska Margin Constrained by GPS

NASA Astrophysics Data System (ADS)

Elliott, J.; Freymueller, J. T.; Larsen, C. F.

2009-12-01

The present-day deformation observed in southcentral and southeast Alaska and the adjacent region of Canada is controlled by two main factors: ~ 50 mm/yr relative motion between the Pacific plate and North America and the Yakutat block’s collision with and accretion to southern Alaska. Over 45 mm/yr of NW-SE directed convergence from the collision is currently accommodated within the St. Elias orogen. The Fairweather, St. Elias, and Chugach ranges show the spectacular consequences of the relative tectonic motions, but the details of the plate interactions have not been well understood. Here we present GPS data from a network of over 170 campaign sites across the region. We use the data to constrain block models and forward models that characterize the nature and extent of the tectonic deformation along the Pacific-Yakutat-North America boundary. Tectonics in southeast Alaska can be described by block motion, with the Pacific plate bounding the region to the west. The fastest block motions occur along the coastal regions. The Yakutat block has a velocity of 51 ± 2.7 mm/yr towards N22 ± 2.5 deg W relative to North America. This velocity has a magnitude almost identical to that of the Pacific plate, but the azimuth is more westerly. The northeastern edge of the Yaktuat block is deforming, represented in our model by two small blocks outboard of the Fairweather fault. East of that fault, the Fairweather block rotates clockwise relative to North America, resulting in transpression along the Duke River and Eastern Denali faults. There is a clear transfer of strain from the coastal region hundreds of kilometers eastward into the Northern Cordillera block, confirming earlier suggestions that the effects of the Yakutat collision are far-reaching along its eastern margin. In contrast, deformation along the leading edge of the Yakutat collision is relatively narrowly focused within the southern half of the St. Elias orogen. The current deformation front of the Yakutat block with southern Alaska is in the vicinity of Icy Bay, where strain rates approach -1 microstrain/yr. The Malaspina thrust likely forms the northern boundary of the Yakutat block. Between Icy Bay and the Mt. St. Elias area, the tectonics cannot easily be described by block motion. The GPS data require the relative convergence to be partitioned onto multiple N-NW dipping thrust faults, resulting in a 50-70-km wide zone of deformation. This zone continues around the western side of Icy Bay into the Yakataga fold and thrust belt. North of the Mt. St. Elias area and the Bagley ice valley, roughly 100 km from the deformation front, GPS velocities are consistent with predictions of the motion of the southern Alaska block.

Ultraprecision XY stage using a hybrid bolt-clamped Langevin-type ultrasonic linear motor for continuous motion.

PubMed

Lee, Dong-Jin; Lee, Sun-Kyu

2015-01-01

This paper presents a design and control system for an XY stage driven by an ultrasonic linear motor. In this study, a hybrid bolt-clamped Langevin-type ultrasonic linear motor was manufactured and then operated at the resonance frequency of the third longitudinal and the sixth lateral modes. These two modes were matched through the preload adjustment and precisely tuned by the frequency matching method based on the impedance matching method with consideration of the different moving weights. The XY stage was evaluated in terms of position and circular motion. To achieve both fine and stable motion, the controller consisted of a nominal characteristics trajectory following (NCTF) control for continuous motion, dead zone compensation, and a switching controller based on the different NCTFs for the macro- and micro-dynamics regimes. The experimental results showed that the developed stage enables positioning and continuous motion with nanometer-level accuracy.

Motion facilitates face perception across changes in viewpoint and expression in older adults.

PubMed

Maguinness, Corrina; Newell, Fiona N

2014-12-01

Faces are inherently dynamic stimuli. However, face perception in younger adults appears to be mediated by the ability to extract structural cues from static images and a benefit of motion is inconsistent. In contrast, static face processing is poorer and more image-dependent in older adults. We therefore compared the role of facial motion in younger and older adults to assess whether motion can enhance perception when static cues are insufficient. In our studies, older and younger adults learned faces presented in motion or in a sequence of static images, containing rigid (viewpoint) or nonrigid (expression) changes. Immediately following learning, participants matched a static test image to the learned face which varied by viewpoint (Experiment 1) or expression (Experiment 2) and was either learned or novel. First, we found an age effect with better face matching performance in younger than in older adults. However, we observed face matching performance improved in the older adult group, across changes in viewpoint and expression, when faces were learned in motion relative to static presentation. There was no benefit for facial (nonrigid) motion when the task involved matching inverted faces (Experiment 3), suggesting that the ability to use dynamic face information for the purpose of recognition reflects motion encoding which is specific to upright faces. Our results suggest that ageing may offer a unique insight into how dynamic cues support face processing, which may not be readily observed in younger adults' performance. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

SU-G-BRA-14: Dose in a Rigidly Moving Phantom with Jaw and MLC Compensation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, E; Lucas, D

Purpose: To validate dose calculation for a rigidly moving object with jaw motion and MLC shifts to compensate for the motion in a TomoTherapy™ treatment delivery. Methods: An off-line version of the TomoTherapy dose calculator was extended to perform dose calculations for rigidly moving objects. A variety of motion traces were added to treatment delivery plans, along with corresponding jaw compensation and MLC shift compensation profiles. Jaw compensation profiles were calculated by shifting the jaws such that the center of the treatment beam moved by an amount equal to the motion in the longitudinal direction. Similarly, MLC compensation profiles weremore » calculated by shifting the MLC leaves by an amount that most closely matched the motion in the transverse direction. The same jaw and MLC compensation profiles were used during simulated treatment deliveries on a TomoTherapy system, and film measurements were obtained in a rigidly moving phantom. Results: The off-line TomoTherapy dose calculator accurately predicted dose profiles for a rigidly moving phantom along with jaw motion and MLC shifts to compensate for the motion. Calculations matched film measurements to within 2%/1 mm. Jaw and MLC compensation substantially reduced the discrepancy between the delivered dose distribution and the calculated dose with no motion. For axial motion, the compensated dose matched the no-motion dose within 2%/1mm. For transverse motion, the dose matched within 2%/3mm (approximately half the width of an MLC leaf). Conclusion: The off-line TomoTherapy dose calculator accurately computes dose delivered to a rigidly moving object, and accurately models the impact of moving the jaws and shifting the MLC leaf patterns to compensate for the motion. Jaw tracking and MLC leaf shifting can effectively compensate for the dosimetric impact of motion during a TomoTherapy treatment delivery.« less

Blocking landing techniques in volleyball and the possible association with anterior cruciate ligament injury.

PubMed

Zahradnik, David; Jandacka, Daniel; Holcapek, Michal; Farana, Roman; Uchytil, Jaroslav; Hamill, Joseph

2018-04-01

The number and type of landings performed after blocking during volleyball matches has been related to the potential risk of ACL injury. The aim of the present study was to determine whether gender affects the frequency of specific blocking landing techniques with potential risk of ACL injury from the perspective of foot contact and subsequent movement after the block used by volleyball players during competitive matches. Three matches involving four female volleyball teams (fourteen sets) and three matches involving four male volleyball teams (thirteen sets) in the Czech Republic were analyzed for this study. A Pearson chi-square test of independence was used to detect the relationship between gender and different blocking techniques. The results of the present study showed that gender affected single-leg landings with subsequent movement in lateral direction and double-leg landings. Although the total number of landings was lower for male athletes than for female athletes, a larger portion of male athletes demonstrated single leg landings with a subsequent movement than female athletes. Single leg landings with a subsequent movement have a higher potential risk of ACL injury.

Steady rotation of the Cascade arc

USGS Publications Warehouse

Wells, Ray E.; McCaffrey, Robert

2013-01-01

Displacement of the Miocene Cascade volcanic arc (northwestern North America) from the active arc is in the same sense and at nearly the same rate as the present clockwise block motions calculated from GPS velocities in a North American reference frame. Migration of the ancestral arc over the past 16 m.y. can be explained by clockwise rotation of upper-plate blocks at 1.0°/m.y. over a linear melting source moving westward 1–4.5 km/m.y. due to slab rollback. Block motion and slab rollback are in opposite directions in the northern arc, but both are westerly in the southern extensional arc, where rollback may be enhanced by proximity to the edge of the Juan de Fuca slab. Similarities between post–16 Ma arc migration, paleomagnetic rotation, and modern GPS block motions indicate that the secular block motions from decadal GPS can be used to calculate long-term strain rates and earthquake hazards. Northwest-directed Basin and Range extension of 140 km is predicted behind the southern arc since 16 Ma, and 70 km of shortening is predicted in the northern arc. The GPS rotation poles overlie a high-velocity slab of the Siletzia terrane dangling into the mantle beneath Idaho (United States), which may provide an anchor for the rotations.

Sub-block motion derivation for merge mode in HEVC

NASA Astrophysics Data System (ADS)

Chien, Wei-Jung; Chen, Ying; Chen, Jianle; Zhang, Li; Karczewicz, Marta; Li, Xiang

2016-09-01

The new state-of-the-art video coding standard, H.265/HEVC, has been finalized in 2013 and it achieves roughly 50% bit rate saving compared to its predecessor, H.264/MPEG-4 AVC. In this paper, two additional merge candidates, advanced temporal motion vector predictor and spatial-temporal motion vector predictor, are developed to improve motion information prediction scheme under the HEVC structure. The proposed method allows each Prediction Unit (PU) to fetch multiple sets of motion information from multiple blocks smaller than the current PU. By splitting a large PU into sub-PUs and filling motion information for all the sub-PUs of the large PU, signaling cost of motion information could be reduced. This paper describes above-mentioned techniques in detail and evaluates their coding performance benefits based on the common test condition during HEVC development. Simulation results show that 2.4% performance improvement over HEVC can be achieved.

Water Polo Game-Related Statistics in Women’s International Championships: Differences and Discriminatory Power

PubMed Central

Escalante, Yolanda; Saavedra, Jose M.; Tella, Victor; Mansilla, Mirella; García-Hermoso, Antonio; Dominguez, Ana M.

2012-01-01

The aims of this study were (i) to compare women’s water polo game-related statistics by match outcome (winning and losing teams) and phase (preliminary, classificatory, and semi-final/bronze medal/gold medal), and (ii) identify characteristics that discriminate performances for each phase. The game-related statistics of the 124 women’s matches played in five International Championships (World and European Championships) were analyzed. Differences between winning and losing teams in each phase were determined using the chi-squared. A discriminant analysis was then performed according to context in each of the three phases. It was found that the game-related statistics differentiate the winning from the losing teams in each phase of an international championship. The differentiating variables were both offensive (centre goals, power-play goals, counterattack goal, assists, offensive fouls, steals, blocked shots, and won sprints) and defensive (goalkeeper-blocked shots, goalkeeper-blocked inferiority shots, and goalkeeper-blocked 5-m shots). The discriminant analysis showed the game-related statistics to discriminate performance in all phases: preliminary, classificatory, and final phases (92%, 90%, and 83%, respectively). Two variables were discriminatory by match outcome (winning or losing teams) in all three phases: goals and goalkeeper-blocked shots. Key pointsThe preliminary phase that more than one variable was involved in this differentiation, including both offensive and defensive aspects of the game.The game-related statistics were found to have a high discriminatory power in predicting the result of matches with shots and goalkeeper-blocked shots being discriminatory variables in all three phases.Knowledge of the characteristics of women’s water polo game-related statistics of the winning teams and their power to predict match outcomes will allow coaches to take these characteristics into account when planning training and match preparation. PMID:24149356

Motion Event Similarity Judgments in One or Two Languages: An Exploration of Monolingual Speakers of English and Chinese vs. L2 Learners of English.

PubMed

Ji, Yinglin

2017-01-01

Languages differ systematically in how to encode a motion event. English characteristically expresses manner in verb root and path in verb particle; in Chinese, varied aspects of motion, such as manner, path and cause, can be simultaneously encoded in a verb compound. This study investigates whether typological differences, as such, influence how first and second language learners conceptualize motion events, as suggested by behavioral evidences. Specifically, the performance of Chinese learners of English, at three proficiencies, was compared to that of two groups of monolingual speakers in a triads matching task. The first set of analyses regarding categorisation preferences indicates that participants across groups preferred the path-matched (rather than manner-matched) screens. However, the second set of analyses regarding reaction time suggests, firstly, that English monolingual speakers reacted significantly more quickly in selecting the manner-matched scenes compared with monolingual speakers of Chinese, who tended to use an approximately equal amount of time in making manner- and path-matched decisions, a finding that can arguably be mapped onto the typological difference between the two languages. Secondly, the pattern of response latency in low-level L2 learners looked more like that of monolingual speakers of Chinese. Only at intermediate and advanced levels of acquisition did the behavioral pattern of L2 learners become target-like, thus suggesting language-specific constraints from the L1 at an early stage of acquisition. Overall, our results suggest that motion event cognition may be linked to, among other things, the linguistic structure of motion description in particular languages.

Human silhouette matching based on moment invariants

NASA Astrophysics Data System (ADS)

Sun, Yong-Chao; Qiu, Xian-Jie; Xia, Shi-Hong; Wang, Zhao-Qi

2005-07-01

This paper aims to apply the method of silhouette matching based on moment invariants to infer the human motion parameters from video sequences of single monocular uncalibrated camera. Currently, there are two ways of tracking human motion: Marker and Markerless. While a hybrid framework is introduced in this paper to recover the input video contents. A standard 3D motion database is built up by marker technique in advance. Given a video sequences, human silhouettes are extracted as well as the viewpoint information of the camera which would be utilized to project the standard 3D motion database onto the 2D one. Therefore, the video recovery problem is formulated as a matching issue of finding the most similar body pose in standard 2D library with the one in video image. The framework is applied to the special trampoline sport where we can obtain the complicated human motion parameters in the single camera video sequences, and a lot of experiments are demonstrated that this approach is feasible in the field of monocular video-based 3D motion reconstruction.

Ultraprecision XY stage using a hybrid bolt-clamped Langevin-type ultrasonic linear motor for continuous motion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Dong-Jin; Lee, Sun-Kyu, E-mail: skyee@gist.ac.kr

2015-01-15

This paper presents a design and control system for an XY stage driven by an ultrasonic linear motor. In this study, a hybrid bolt-clamped Langevin-type ultrasonic linear motor was manufactured and then operated at the resonance frequency of the third longitudinal and the sixth lateral modes. These two modes were matched through the preload adjustment and precisely tuned by the frequency matching method based on the impedance matching method with consideration of the different moving weights. The XY stage was evaluated in terms of position and circular motion. To achieve both fine and stable motion, the controller consisted of amore » nominal characteristics trajectory following (NCTF) control for continuous motion, dead zone compensation, and a switching controller based on the different NCTFs for the macro- and micro-dynamics regimes. The experimental results showed that the developed stage enables positioning and continuous motion with nanometer-level accuracy.« less

Metaphors are Embodied, and so are Their Literal Counterparts

PubMed Central

Santana, Eduardo; de Vega, Manuel

2011-01-01

This study investigates whether understanding up/down metaphors as well as semantically homologous literal sentences activates embodied representations online. Participants read orientational literal sentences (e.g., she climbed up the hill), metaphors (e.g., she climbed up in the company), and abstract sentences with similar meaning to the metaphors (e.g., she succeeded in the company). In Experiments 1 and 2, participants were asked to perform a speeded upward or downward hand motion while they were reading the sentence verb. The hand motion either matched or mismatched the direction connoted by the sentence. The results showed a meaning-action effect for metaphors and literals, that is, faster hand motion responses in the matching conditions. Notably, the matching advantage was also found for homologous abstract sentences, indicating that some abstract ideas are conceptually organized in the vertical dimension, even when they are expressed by means of literal sentences. In Experiment 3, participants responded to an upward or downward visual motion associated with the sentence verb by pressing a single key. In this case, the facilitation effect for matching visual motion-sentence meaning faded, indicating that the visual motion component is less important than the action component in conceptual metaphors. Most up and down metaphors convey emotionally positive and negative information, respectively. We suggest that metaphorical meaning elicits upward/downward movements because they are grounded on the bodily expression of the corresponding emotions. PMID:21687459

4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

NASA Astrophysics Data System (ADS)

O'Shea, Tuathan P.; Garcia, Leo J.; Rosser, Karen E.; Harris, Emma J.; Evans, Philip M.; Bamber, Jeffrey C.

2014-04-01

This study investigates the use of a mechanically-swept 3D ultrasound (3D-US) probe for soft-tissue displacement monitoring during prostate irradiation, with emphasis on quantifying the accuracy relative to CyberKnife® x-ray fiducial tracking. An US phantom, implanted with x-ray fiducial markers was placed on a motion platform and translated in 3D using five real prostate motion traces acquired using the Calypso system. Motion traces were representative of all types of motion as classified by studying Calypso data for 22 patients. The phantom was imaged using a 3D swept linear-array probe (to mimic trans-perineal imaging) and, subsequently, the kV x-ray imaging system on CyberKnife. A 3D cross-correlation block-matching algorithm was used to track speckle in the ultrasound data. Fiducial and US data were each compared with known phantom displacement. Trans-perineal 3D-US imaging could track superior-inferior (SI) and anterior-posterior (AP) motion to ≤0.81 mm root-mean-square error (RMSE) at a 1.7 Hz volume rate. The maximum kV x-ray tracking RMSE was 0.74 mm, however the prostate motion was sampled at a significantly lower imaging rate (mean: 0.04 Hz). Initial elevational (right-left RL) US displacement estimates showed reduced accuracy but could be improved (RMSE <2.0 mm) using a correlation threshold in the ultrasound tracking code to remove erroneous inter-volume displacement estimates. Mechanically-swept 3D-US can track the major components of intra-fraction prostate motion accurately but exhibits some limitations. The largest US RMSE was for elevational (RL) motion. For the AP and SI axes, accuracy was sub-millimetre. It may be feasible to track prostate motion in 2D only. 3D-US also has the potential to improve high tracking accuracy for all motion types. It would be advisable to use US in conjunction with a small (˜2.0 mm) centre-of-mass displacement threshold in which case it would be possible to take full advantage of the accuracy and high imaging rate capability.

ESTCP Live Site Demonstrations Former Camp Beale

DTIC Science & Technology

2012-03-01

Mode Tx Mode Hold-Off Time (µs) Block Period (s) Rep Fctr Dec Fctr (%) Stk Const Base Freq (Hz) Decay Time (us) No. Gates Sample...contained in the AcqParams block of the TEM data file. It is not used for static data interpretation. Sample Period: The Block Time * Stk Constant...Analyze returned a 0.8016 confidence metric match between target BE-1500 and a 105mm projectile, the polarizability curves did not visually match those

Motion-Compensated Compression of Dynamic Voxelized Point Clouds.

PubMed

De Queiroz, Ricardo L; Chou, Philip A

2017-05-24

Dynamic point clouds are a potential new frontier in visual communication systems. A few articles have addressed the compression of point clouds, but very few references exist on exploring temporal redundancies. This paper presents a novel motion-compensated approach to encoding dynamic voxelized point clouds at low bit rates. A simple coder breaks the voxelized point cloud at each frame into blocks of voxels. Each block is either encoded in intra-frame mode or is replaced by a motion-compensated version of a block in the previous frame. The decision is optimized in a rate-distortion sense. In this way, both the geometry and the color are encoded with distortion, allowing for reduced bit-rates. In-loop filtering is employed to minimize compression artifacts caused by distortion in the geometry information. Simulations reveal that this simple motion compensated coder can efficiently extend the compression range of dynamic voxelized point clouds to rates below what intra-frame coding alone can accommodate, trading rate for geometry accuracy.

Which skills and factors better predict winning and losing in high-level men's volleyball?

PubMed

Peña, Javier; Rodríguez-Guerra, Jorge; Buscà, Bernat; Serra, Núria

2013-09-01

The aim of this study was to determine which skills and factors better predicted the outcomes of regular season volleyball matches in the Spanish "Superliga" and were significant for obtaining positive results in the game. The study sample consisted of 125 matches played during the 2010-11 Spanish men's first division volleyball championship. Matches were played by 12 teams composed of 148 players from 17 different nations from October 2010 to March 2011. The variables analyzed were the result of the game, team category, home/away court factors, points obtained in the break point phase, number of service errors, number of service aces, number of reception errors, percentage of positive receptions, percentage of perfect receptions, reception efficiency, number of attack errors, number of blocked attacks, attack points, percentage of attack points, attack efficiency, and number of blocks performed by both teams participating in the match. The results showed that the variables of team category, points obtained in the break point phase, number of reception errors, and number of blocked attacks by the opponent were significant predictors of winning or losing the matches. Odds ratios indicated that the odds of winning a volleyball match were 6.7 times greater for the teams belonging to higher rankings and that every additional point in Complex II increased the odds of winning a match by 1.5 times. Every reception and blocked ball error decreased the possibility of winning by 0.6 and 0.7 times, respectively.

Matching Speaking to Singing Voices and the Influence of Content.

PubMed

Peynircioğlu, Zehra F; Rabinovitz, Brian E; Repice, Juliana

2017-03-01

We tested whether speaking voices of unfamiliar people could be matched to their singing voices, and, if so, whether the content of the utterances would influence this matching performance. Our hypothesis was that enough acoustic features would remain the same between speaking and singing voices such that their identification as belonging to the same or different individuals would be possible even upon a single hearing. We also hypothesized that the contents of the utterances would influence this identification process such that voices uttering words would be easier to match than those uttering vowels. We used a within-participant design with blocked stimuli that were counterbalanced using a Latin square design. In one block, mode (speaking vs singing) was manipulated while content was held constant; in another block, content (word vs syllable) was manipulated while mode was held constant, and in the control block, both mode and content were held constant. Participants indicated whether the voices in any given pair of utterances belonged to the same person or to different people. Cross-mode matching was above chance level, although mode-congruent performance was better. Further, only speaking voices were easier to match when uttering words. We can identify speaking and singing voices as the same or different even on just a single hearing. However, content interacts with mode such that words benefit matching of speaking voices but not of singing voices. Results are discussed within an attentional framework. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Evolutionary Fuzzy Block-Matching-Based Camera Raw Image Denoising.

PubMed

Yang, Chin-Chang; Guo, Shu-Mei; Tsai, Jason Sheng-Hong

2017-09-01

An evolutionary fuzzy block-matching-based image denoising algorithm is proposed to remove noise from a camera raw image. Recently, a variance stabilization transform is widely used to stabilize the noise variance, so that a Gaussian denoising algorithm can be used to remove the signal-dependent noise in camera sensors. However, in the stabilized domain, the existed denoising algorithm may blur too much detail. To provide a better estimate of the noise-free signal, a new block-matching approach is proposed to find similar blocks by the use of a type-2 fuzzy logic system (FLS). Then, these similar blocks are averaged with the weightings which are determined by the FLS. Finally, an efficient differential evolution is used to further improve the performance of the proposed denoising algorithm. The experimental results show that the proposed denoising algorithm effectively improves the performance of image denoising. Furthermore, the average performance of the proposed method is better than those of two state-of-the-art image denoising algorithms in subjective and objective measures.

Motion Event Similarity Judgments in One or Two Languages: An Exploration of Monolingual Speakers of English and Chinese vs. L2 Learners of English

PubMed Central

Ji, Yinglin

2017-01-01

Languages differ systematically in how to encode a motion event. English characteristically expresses manner in verb root and path in verb particle; in Chinese, varied aspects of motion, such as manner, path and cause, can be simultaneously encoded in a verb compound. This study investigates whether typological differences, as such, influence how first and second language learners conceptualize motion events, as suggested by behavioral evidences. Specifically, the performance of Chinese learners of English, at three proficiencies, was compared to that of two groups of monolingual speakers in a triads matching task. The first set of analyses regarding categorisation preferences indicates that participants across groups preferred the path-matched (rather than manner-matched) screens. However, the second set of analyses regarding reaction time suggests, firstly, that English monolingual speakers reacted significantly more quickly in selecting the manner-matched scenes compared with monolingual speakers of Chinese, who tended to use an approximately equal amount of time in making manner- and path-matched decisions, a finding that can arguably be mapped onto the typological difference between the two languages. Secondly, the pattern of response latency in low-level L2 learners looked more like that of monolingual speakers of Chinese. Only at intermediate and advanced levels of acquisition did the behavioral pattern of L2 learners become target-like, thus suggesting language-specific constraints from the L1 at an early stage of acquisition. Overall, our results suggest that motion event cognition may be linked to, among other things, the linguistic structure of motion description in particular languages. PMID:28638355

Audio–visual interactions for motion perception in depth modulate activity in visual area V3A

PubMed Central

Ogawa, Akitoshi; Macaluso, Emiliano

2013-01-01

Multisensory signals can enhance the spatial perception of objects and events in the environment. Changes of visual size and auditory intensity provide us with the main cues about motion direction in depth. However, frequency changes in audition and binocular disparity in vision also contribute to the perception of motion in depth. Here, we presented subjects with several combinations of auditory and visual depth-cues to investigate multisensory interactions during processing of motion in depth. The task was to discriminate the direction of auditory motion in depth according to increasing or decreasing intensity. Rising or falling auditory frequency provided an additional within-audition cue that matched or did not match the intensity change (i.e. intensity-frequency (IF) “matched vs. unmatched” conditions). In two-thirds of the trials, a task-irrelevant visual stimulus moved either in the same or opposite direction of the auditory target, leading to audio–visual “congruent vs. incongruent” between-modalities depth-cues. Furthermore, these conditions were presented either with or without binocular disparity. Behavioral data showed that the best performance was observed in the audio–visual congruent condition with IF matched. Brain imaging results revealed maximal response in visual area V3A when all cues provided congruent and reliable depth information (i.e. audio–visual congruent, IF-matched condition including disparity cues). Analyses of effective connectivity revealed increased coupling from auditory cortex to V3A specifically in audio–visual congruent trials. We conclude that within- and between-modalities cues jointly contribute to the processing of motion direction in depth, and that they do so via dynamic changes of connectivity between visual and auditory cortices. PMID:23333414

Analysis of ground state in random bipartite matching

NASA Astrophysics Data System (ADS)

Shi, Gui-Yuan; Kong, Yi-Xiu; Liao, Hao; Zhang, Yi-Cheng

2016-02-01

Bipartite matching problems emerge in many human social phenomena. In this paper, we study the ground state of the Gale-Shapley model, which is the most popular bipartite matching model. We apply the Kuhn-Munkres algorithm to compute the numerical ground state of the model. For the first time, we obtain the number of blocking pairs which is a measure of the system instability. We also show that the number of blocking pairs formed by each person follows a geometric distribution. Furthermore, we study how the connectivity in the bipartite matching problems influences the instability of the ground state.

An SRRC elliptically polarizing undulator prototype to examine mechanical design feasibility and magnetic field performance.

PubMed

Chang, C H; Hwang, C S; Fan, T C; Chen, K H; Pan, K T; Lin, F Y; Wang, C; Chang, L H; Chen, H H; Lin, M C; Yeh, S

1998-05-01

In this work, a 1 m long Sasaki-type elliptically polarizing undulator (EPU) prototype with 5.6 cm period length is used to examine the mechanical design feasibility as well as magnetic field performance. The magnetic field characteristics of the EPU5.6 prototype at various phase shifts and gap motion are described. The field errors from mechanical tolerances, magnet block errors, end field effects and phase/gap motion effects are analysed. The procedures related to correcting the field with the block position tuning, iron shimming and the trim blocks at both ends are outlined.

A Proper-Motion Corrected, Cross-Matched Catalog Of M Dwarfs In SDSS And FIRST

NASA Astrophysics Data System (ADS)

Arai, Erin; West, A. A.; Thyagarajan, N.; Agüeros, M.; Helfand, D.

2011-05-01

We present a preliminary analysis of M dwarfs identified in both the Sloan Digital Sky Survey (SDSS) and the Very Large Array's (VLA) Faint Images of the Radio Sky at Twenty-centimeters survey (FIRST). The presence of magnetic fields is often associated with indirect magnetic activity measurements, such as H-alpha or X-ray emission. Radio emission, in contrast, is directly proportional to the magnetic field strength in addition to being another measure of activity. We search for stellar radio emission by cross-matching the SDSS DR7 M dwarf sample with the FIRST catalog. The SDSS data allow us to examine the spectra of our objects and correlate the magnetic activity (H-alpha) with the magnetic field strength (radio emission). Accurate positions and proper motions are important for obtaining a complete list of overlapping targets. Positions in FIRST and SDSS need to be proper motion corrected in order to ensure unique target matches since nearby M dwarfs can have significant proper motions (up to 1'' per year). Some previous studies have neglected the significance of proper motions in identifying overlapping targets between SDSS and FIRST; we correct for some of these previous oversights. In addition the FIRST data were taken in multiple epochs; individual images need to be proper motion corrected before the images can be co-added. Our cross-match catalog puts important constraints on models of magnetic field generation in low-mass stars in addition to the true habitability of attending planets.

Molecular dynamics simulation of square graphene-nanoflake oscillator on graphene nanoribbon.

PubMed

Kang, Jeong Won; Lee, Kang Whan

2014-12-01

Graphene nanoflakes (GNFs) have been of interest for a building block in order to develop electromechanical devices on a nanometer scale. Here, we present the oscillation motions of a square GNF oscillator on graphene nanoribbon (GNR) in the retracting-motions by performing classical molecular dynamics simulations. The simulation results showed that the GNF oscillators can be considered as a building block for nanoelectromechanical systems such as carbon-nanotube (CNT) oscillators. The oscillation dynamics of the GNF oscillator were similar to those of the CNT oscillators. When the square GNF had an initial velocity as impulse dynamics, its oscillation motions on the GNR were achieved from its self-retracting van der Waals force. For low initial velocity, its translational motions were dominant in its motions rather than its rotational motions. The kinetic energy damping ratio rapidly decreased as initial velocity increased and the kinetic energy for the translational motion of the GNF oscillator rapidly transferred into that for its rotational motion. The oscillation frequency of the GNF oscillator was dependent on its initial velocity.

Markov prior-based block-matching algorithm for superdimension reconstruction of porous media

NASA Astrophysics Data System (ADS)

Li, Yang; He, Xiaohai; Teng, Qizhi; Feng, Junxi; Wu, Xiaohong

2018-04-01

A superdimension reconstruction algorithm is used for the reconstruction of three-dimensional (3D) structures of a porous medium based on a single two-dimensional image. The algorithm borrows the concepts of "blocks," "learning," and "dictionary" from learning-based superresolution reconstruction and applies them to the 3D reconstruction of a porous medium. In the neighborhood-matching process of the conventional superdimension reconstruction algorithm, the Euclidean distance is used as a criterion, although it may not really reflect the structural correlation between adjacent blocks in an actual situation. Hence, in this study, regular items are adopted as prior knowledge in the reconstruction process, and a Markov prior-based block-matching algorithm for superdimension reconstruction is developed for more accurate reconstruction. The algorithm simultaneously takes into consideration the probabilistic relationship between the already reconstructed blocks in three different perpendicular directions (x , y , and z ) and the block to be reconstructed, and the maximum value of the probability product of the blocks to be reconstructed (as found in the dictionary for the three directions) is adopted as the basis for the final block selection. Using this approach, the problem of an imprecise spatial structure caused by a point simulation can be overcome. The problem of artifacts in the reconstructed structure is also addressed through the addition of hard data and by neighborhood matching. To verify the improved reconstruction accuracy of the proposed method, the statistical and morphological features of the results from the proposed method and traditional superdimension reconstruction method are compared with those of the target system. The proposed superdimension reconstruction algorithm is confirmed to enable a more accurate reconstruction of the target system while also eliminating artifacts.

MPEG-1 low-cost encoder solution

NASA Astrophysics Data System (ADS)

Grueger, Klaus; Schirrmeister, Frank; Filor, Lutz; von Reventlow, Christian; Schneider, Ulrich; Mueller, Gerriet; Sefzik, Nicolai; Fiedrich, Sven

1995-02-01

A solution for real-time compression of digital YCRCB video data to an MPEG-1 video data stream has been developed. As an additional option, motion JPEG and video telephone streams (H.261) can be generated. For MPEG-1, up to two bidirectional predicted images are supported. The required computational power for motion estimation and DCT/IDCT, memory size and memory bandwidth have been the main challenges. The design uses fast-page-mode memory accesses and requires only one single 80 ns EDO-DRAM with 256 X 16 organization for video encoding. This can be achieved only by using adequate access and coding strategies. The architecture consists of an input processing and filter unit, a memory interface, a motion estimation unit, a motion compensation unit, a DCT unit, a quantization control, a VLC unit and a bus interface. For using the available memory bandwidth by the processing tasks, a fixed schedule for memory accesses has been applied, that can be interrupted for asynchronous events. The motion estimation unit implements a highly sophisticated hierarchical search strategy based on block matching. The DCT unit uses a separated fast-DCT flowgraph realized by a switchable hardware unit for both DCT and IDCT operation. By appropriate multiplexing, only one multiplier is required for: DCT, quantization, inverse quantization, and IDCT. The VLC unit generates the video-stream up to the video sequence layer and is directly coupled with an intelligent bus-interface. Thus, the assembly of video, audio and system data can easily be performed by the host computer. Having a relatively low complexity and only small requirements for DRAM circuits, the developed solution can be applied to low-cost encoding products for consumer electronics.

Noninvasive evaluation of contractile behavior of cardiomyocyte monolayers based on motion vector analysis.

PubMed

Hayakawa, Tomohiro; Kunihiro, Takeshi; Dowaki, Suguru; Uno, Hatsume; Matsui, Eriko; Uchida, Masashi; Kobayashi, Seiji; Yasuda, Akio; Shimizu, Tatsuya; Okano, Teruo

2012-01-01

A noninvasive method for the characterization of cardiomyocyte contractile behavior is presented. Light microscopic video images of cardiomyocytes were captured with a high-speed camera, and motion vectors (which have a velocity dimension) were calculated with a high spatiotemporal resolution using a block-matching algorithm. This method could extract contraction and relaxation motions of cardiomyocytes separately and evaluate characteristics such as the beating rate, orientation of contraction, beating cooperativity/homogeneity in the monolayer, and wave propagation of impulses. Simultaneous phase-contrast imaging and calcium (Ca2+) fluorescence measurements confirmed that the timing of the maximum shortening velocity of cardiomyocytes correlated well with intracellular Ca2+ transients. Based on our analysis, gap junction inhibitors, 1-heptanol (2 mM) or 18-β-glycyrrhetinic acid (30 μM), resulted in clear changes in beating cooperativity and the propagation pattern of impulses in the cardiomyocyte monolayer. Additionally, the time dependence of the motion vector length indicated a prolonged relaxation process in the presence of potassium (K+) channel blockers, dl-sotalol (1 μM), E-4031 (100 nM), or terfenadine (100 nM), reflecting the prolonged QT (Q wave and T wave) interval of cardiomyocytes. Effects of autonomic agents (acetylcholine or epinephrine [EPI]) or EPI and propranolol on cardiomyocytes were clearly detected by the alterations of beating rate and the motion vector length in contraction and relaxation processes. This method was noninvasive and could sensitively evaluate the contractile behavior of cardiomyocytes; therefore, it may be used to study and/or monitor cardiomyocyte tissue during prolonged culture periods and in screens for drugs that may alter the contraction of cardiomyocytes.

A Hybrid Program for Fitting Rotationally Resolved Spectra of Floppy Molecules with One Large-Amplitude Rotatory Motion and One Large-Amplitude Oscillatory Motion

PubMed Central

Kleiner, Isabelle; Hougen, Jon T.

2015-01-01

A new hybrid-model fitting program for methylamine-like molecules has been developed, based on an effective Hamiltonian in which the ammonia-like inversion motion is treated using a tunneling formalism, while the internal-rotation motion is treated using an explicit kinetic energy operator and potential energy function. The Hamiltonian in the computer program is set up as a 2×2 partitioned matrix, where each diagonal block contains a traditional torsion-rotation Hamiltonian (as in the earlier program BELGI), and the two off-diagonal blocks contain tunneling terms. This hybrid formulation permits the use of the permutation-inversion group G6 (isomorphic to C3v) for terms in the two diagonal blocks, but requires G12 for terms in the off-diagonal blocks. The first application of the new program is to 2-methylmalonaldehyde. Microwave data for this molecule were previously fit using an all-tunneling Hamiltonian formalism to treat both large-amplitude-motions. For 2-methylmalonaldehyde, the hybrid program achieves the same quality of fit as was obtained with the all-tunneling program, but fits with the hybrid program eliminate a large discrepancy between internal rotation barriers in the OH and OD isotopologs of 2-methylmalonaldehyde that arose in fits with the all-tunneling program. This large isotopic shift in internal rotation barrier is thus almost certainly an artifact of the all-tunneling model. Other molecules for application of the hybrid program are mentioned. PMID:26439709

Coding tools investigation for next generation video coding based on HEVC

NASA Astrophysics Data System (ADS)

Chen, Jianle; Chen, Ying; Karczewicz, Marta; Li, Xiang; Liu, Hongbin; Zhang, Li; Zhao, Xin

2015-09-01

The new state-of-the-art video coding standard, H.265/HEVC, has been finalized in 2013 and it achieves roughly 50% bit rate saving compared to its predecessor, H.264/MPEG-4 AVC. This paper provides the evidence that there is still potential for further coding efficiency improvements. A brief overview of HEVC is firstly given in the paper. Then, our improvements on each main module of HEVC are presented. For instance, the recursive quadtree block structure is extended to support larger coding unit and transform unit. The motion information prediction scheme is improved by advanced temporal motion vector prediction, which inherits the motion information of each small block within a large block from a temporal reference picture. Cross component prediction with linear prediction model improves intra prediction and overlapped block motion compensation improves the efficiency of inter prediction. Furthermore, coding of both intra and inter prediction residual is improved by adaptive multiple transform technique. Finally, in addition to deblocking filter and SAO, adaptive loop filter is applied to further enhance the reconstructed picture quality. This paper describes above-mentioned techniques in detail and evaluates their coding performance benefits based on the common test condition during HEVC development. The simulation results show that significant performance improvement over HEVC standard can be achieved, especially for the high resolution video materials.

Can CT-based patient-matched instrumentation achieve consistent rotational alignment in knee arthroplasty?

PubMed

Tibesku, C O; Innocenti, B; Wong, P; Salehi, A; Labey, L

2012-02-01

Long-term success of contemporary total knee replacements relies to a large extent on proper implant alignment. This study was undertaken to test whether specimen-matched cutting blocks based on computed axial tomography (CT) scans could provide accurate rotational alignment of the femoral component. CT scans of five fresh frozen full leg cadaver specimens, equipped with infrared reflective markers, were used to produce a specimen-matched femoral cutting block. Using those blocks, the bone cuts were made to implant a bi-compartmental femoral component. Rotational alignment of the components in the horizontal plane was determined using an optical measurement system and compared with all relevant rotational reference axes identified on the CT scans. Average rotational alignment for the bi-compartmental component in the horizontal plane was 1.9° (range 0°-6.3°; standard deviation 2.6°). One specimen that showed the highest deviation from the planned alignment also featured a completely degraded medial articular surface. The CT-based specimen-matched cutting blocks achieved good rotational alignment accuracy except for one specimen with badly damaged cartilage. In such cases, imaging techniques that visualize the cartilage layer might be more suitable to design cutting blocks, as they will provide a better fit and increased surface support.

Termites live in a material world: exploration of their ability to differentiate between food sources.

PubMed

Inta, Ra; Lai, Joseph C S; Fu, Eugene W; Evans, Theodore A

2007-08-22

Drywood termites are able to assess wood size using vibratory signals, although the exact mechanism behind this assessment ability is not known. Important vibratory characteristics such as the modal frequencies of a wooden block depend on its geometry and boundary conditions; however, they are also dependent on the material characteristics of the block, such as mass, density and internal damping. We report here on choice experiments that tested the ability of the drywood termite Cryptotermes secundus to assess wooden block size using a solid wooden block paired with a composite block, the latter made of either wood and aluminium or wood and rubber. Each composite block was constructed to match mass or low-frequency vibratory modes (i.e. fundamental frequency) of the solid wooden block. The termites always chose the blocks with more wood; they moved to the solid wooden blocks usually within a day and then tunnelled further into the solid wooden block by the end of the experiment. Termites offered composite blocks of wood and rubber matched for mass were the slowest to show a preference for the solid wooden block and this preference was the least definitive of any treatment, which indicated that mass and/or damping may play a role in food assessment. This result clearly shows that the termites were not fooled by composite blocks matched for mass or frequency, which implies that they probably employ more than a single simple measure in their food assessment strategy. This implies a degree of sophistication in their ability to assess their environment hitherto unknown. The potential importance of alternative features in the vibrational signals is discussed.

A review of the paleomagnetic data from Cretaceous to lower Tertiary rocks from Vietnam, Indochina and South China, and their implications for Cenozoic tectonism in Vietnam and adjacent areas

NASA Astrophysics Data System (ADS)

Cung, Thu'ọ'ng Chí; Geissman, John W.

2013-09-01

Available paleomagnetic data from rock formations of Cretaceous age from Vietnam, Indochina and South China are compiled and reviewed in the context of their tectonic importance in a common reference frame with respect to Eurasia's coeval paleopoles. Key factors that play an important role in determining the reliability of a paleomagnetic result for utilization in tectonic studies have been taken into consideration and include the absence of evidence of remagnetization, which is a feature common to many rocks in this region. Overall, the Cretaceous paleomagnetic data from the South China Block show that the present geographic position of the South China Block has been relatively stable with respect to Eurasia since the mid-Cretaceous and that the paleomagnetically detected motion of a coherent lithospheric block must be based on the representative data obtained from different specific localities across the block in order to separate more localized, smaller scale deformation from true lithosphere scale motion (translation and/or rotation) of a tectonic block. Cretaceous to early Tertiary paleomagnetic data from the Indochina-Shan Thai Block reveal complex patterns of intra-plate deformation in response to the India-Eurasia collision. Paleomagnetically detected motions from the margins of tectonic blocks are interpreted to mainly reflect displacement of upper crustal blocks due to folding and faulting processes. Rigid, lithosphere scale block rotation is not necessarily supported by the paleomagnetic data. The paleomagnetic results from areas east and south of the Red River fault system suggest that this major transcurrent fault system has had a complicated slip history through much of the Cenozoic and that it does not demarcate completely non-rotated and significantly rotated parts of the crust in this area. However, most paleomagnetic results from areas east and south of the Red River fault system at the latitude of Yunnan Province are consistent with a very modest (about 800 km+-), yet paleomagnetically resolvable southward component of latitudinal translation. Accordingly, given the difficulty in separating actual lithosphere-scale plate motions from those of relatively thin, upper crustal blocks, we advocate extreme caution in interpreting paleomagnetic data from regions such as Indochina where block interaction and strong deformation are known to have occurred.

Needle detection in ultrasound using the spectral properties of the displacement field: a feasibility study

NASA Astrophysics Data System (ADS)

Beigi, Parmida; Salcudean, Tim; Rohling, Robert; Lessoway, Victoria A.; Ng, Gary C.

2015-03-01

This paper presents a new needle detection technique for ultrasound guided interventions based on the spectral properties of small displacements arising from hand tremour or intentional motion. In a block-based approach, the displacement map is computed for each block of interest versus a reference frame, using an optical flow technique. To compute the flow parameters, the Lucas-Kanade approach is used in a multiresolution and regularized form. A least-squares fit is used to estimate the flow parameters from the overdetermined system of spatial and temporal gradients. Lateral and axial components of the displacement are obtained for each block of interest at consecutive frames. Magnitude-squared spectral coherency is derived between the median displacements of the reference block and each block of interest, to determine the spectral correlation. In vivo images were obtained from the tissue near the abdominal aorta to capture the extreme intrinsic body motion and insertion images were captured from a tissue-mimicking agar phantom. According to the analysis, both the involuntary and intentional movement of the needle produces coherent displacement with respect to a reference window near the insertion site. Intrinsic body motion also produces coherent displacement with respect to a reference window in the tissue; however, the coherency spectra of intrinsic and needle motion are distinguishable spectrally. Blocks with high spectral coherency at high frequencies are selected, estimating a channel for needle trajectory. The needle trajectory is detected from locally thresholded absolute displacement map within the initial estimate. Experimental results show the RMS localization accuracy of 1:0 mm, 0:7 mm, and 0:5 mm for hand tremour, vibrational and rotational needle movements, respectively.

The Presence of Thyroid-Stimulation Blocking Antibody Prevents High Bone Turnover in Untreated Premenopausal Patients with Graves' Disease.

PubMed

Cho, Sun Wook; Bae, Jae Hyun; Noh, Gyeong Woon; Kim, Ye An; Moon, Min Kyong; Park, Kyoung Un; Song, Junghan; Yi, Ka Hee; Park, Do Joon; Chung, June-Key; Cho, Bo Youn; Park, Young Joo

2015-01-01

Osteoporosis-related fractures are one of the complications of Graves' disease. This study hypothesized that the different actions of thyroid-stimulating hormone receptor (TSHR) antibodies, both stimulating and blocking activities in Graves' disease patients might oppositely impact bone turnover. Newly diagnosed premenopausal Graves' disease patients were enrolled (n = 93) and divided into two groups: patients with TSHR antibodies with thyroid-stimulating activity (stimulating activity group, n = 83) and patients with TSHR antibodies with thyroid-stimulating activity combined with blocking activity (blocking activity group, n = 10). From the stimulating activity group, patients who had matched values for free T4 and TSH binding inhibitor immunoglobulin (TBII) to the blocking activity group were further classified as stimulating activity-matched control (n = 11). Bone turnover markers BS-ALP, Osteocalcin, and C-telopeptide were significantly lower in the blocking activity group than in the stimulating activity or stimulating activity-matched control groups. The TBII level showed positive correlations with BS-ALP and osteocalcin levels in the stimulating activity group, while it had a negative correlation with the osteocalcin level in the blocking activity group. In conclusion, the activation of TSHR antibody-activated TSH signaling contributes to high bone turnover, independent of the actions of thyroid hormone, and thyroid-stimulation blocking antibody has protective effects against bone metabolism in Graves' disease.

The Matching Criterion Purification for Differential Item Functioning Analyses in a Large-Scale Assessment

ERIC Educational Resources Information Center

Lee, HyeSun; Geisinger, Kurt F.

2016-01-01

The current study investigated the impact of matching criterion purification on the accuracy of differential item functioning (DIF) detection in large-scale assessments. The three matching approaches for DIF analyses (block-level matching, pooled booklet matching, and equated pooled booklet matching) were employed with the Mantel-Haenszel…

Dislocation model for aseismic fault slip in the transverse ranges of Southern California

NASA Technical Reports Server (NTRS)

Cheng, A.; Jackson, D. D.; Matsuura, M.

1985-01-01

Geodetic data at a plate boundary can reveal the pattern of subsurface displacements that accompany plate motion. These displacements are modelled as the sum of rigid block motion and the elastic effects of frictional interaction between blocks. The frictional interactions are represented by uniform dislocation on each of several rectangular fault patches. The block velocities and fault parameters are then estimated from geodetic data. Bayesian inversion procedure employs prior estimates based on geological and seismological data. The method is applied to the Transverse Ranges, using prior geological and seismological data and geodetic data from the USGS trilateration networks. Geodetic data imply a displacement rate of about 20 mm/yr across the San Andreas Fault, while the geologic estimates exceed 30 mm/yr. The prior model and the final estimates both imply about 10 mm/yr crustal shortening normal to the trend of the San Andreas Fault. Aseismic fault motion is a major contributor to plate motion. The geodetic data can help to identify faults that are suffering rapid stress accumulation; in the Transverse Ranges those faults are the San Andreas and the Santa Susana.

On Integral Invariants for Effective 3-D Motion Trajectory Matching and Recognition.

PubMed

Shao, Zhanpeng; Li, Youfu

2016-02-01

Motion trajectories tracked from the motions of human, robots, and moving objects can provide an important clue for motion analysis, classification, and recognition. This paper defines some new integral invariants for a 3-D motion trajectory. Based on two typical kernel functions, we design two integral invariants, the distance and area integral invariants. The area integral invariants are estimated based on the blurred segment of noisy discrete curve to avoid the computation of high-order derivatives. Such integral invariants for a motion trajectory enjoy some desirable properties, such as computational locality, uniqueness of representation, and noise insensitivity. Moreover, our formulation allows the analysis of motion trajectories at a range of scales by varying the scale of kernel function. The features of motion trajectories can thus be perceived at multiscale levels in a coarse-to-fine manner. Finally, we define a distance function to measure the trajectory similarity to find similar trajectories. Through the experiments, we examine the robustness and effectiveness of the proposed integral invariants and find that they can capture the motion cues in trajectory matching and sign recognition satisfactorily.

Vision-Based UAV Flight Control and Obstacle Avoidance

DTIC Science & Technology

2006-01-01

denoted it by Vb = (Vb1, Vb2 , Vb3). Fig. 2 shows the block diagram of the proposed vision-based motion analysis and obstacle avoidance system. We denote...structure analysis often involve computation- intensive computer vision tasks, such as feature extraction and geometric modeling. Computation-intensive...First, we extract a set of features from each block. 2) Second, we compute the distance between these two sets of features. In conventional motion

A coarse-to-fine kernel matching approach for mean-shift based visual tracking

NASA Astrophysics Data System (ADS)

Liangfu, L.; Zuren, F.; Weidong, C.; Ming, J.

2009-03-01

Mean shift is an efficient pattern match algorithm. It is widely used in visual tracking fields since it need not perform whole search in the image space. It employs gradient optimization method to reduce the time of feature matching and realize rapid object localization, and uses Bhattacharyya coefficient as the similarity measure between object template and candidate template. This thesis presents a mean shift algorithm based on coarse-to-fine search for the best kernel matching. This paper researches for object tracking with large motion area based on mean shift. To realize efficient tracking of such an object, we present a kernel matching method from coarseness to fine. If the motion areas of the object between two frames are very large and they are not overlapped in image space, then the traditional mean shift method can only obtain local optimal value by iterative computing in the old object window area, so the real tracking position cannot be obtained and the object tracking will be disabled. Our proposed algorithm can efficiently use a similarity measure function to realize the rough location of motion object, then use mean shift method to obtain the accurate local optimal value by iterative computing, which successfully realizes object tracking with large motion. Experimental results show its good performance in accuracy and speed when compared with background-weighted histogram algorithm in the literature.

A MEMS scanner with lateral and axial scanning capability for dual axes confocal endomicroscopic in-vivo imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Li, Haijun; Li, Gaoming; Duan, Xiyu; Wang, Thomas D.

2017-02-01

Aimed to build a dual-axes confocal endomicroscope with an outer diameter of 5.5mm for in-vivo imaging applications, an electrostatic MEMS scanner has been developed to enable two dimensional (2D) light scanning in either horizontal plane or vertical cross-sectional plane. The device has a compact structure design to match the dual axes confocal architecture in the probe without blocking the collimated light beams of excitation and collection, and a cutting-free silicon-on-insulator(SOI) micromachining process is used for the fabrication. A novel lever-based gimbal-like mechanism is employed to enable three degrees of freedom motions for lateral and axial light scanning, and its geometry is optimized for achieving large deflection with high scanning speed. Based on parametric excitation, the device can work in resonant modes. Testing result shows that, up to +/-27° optical deflection angle for inner axis torsion motion with a frequency of 4.9kHz, up to +/-28.5° optical deflection angle for outer axis torsion motion with a frequency of 0.65kHz and 360μm stroke for out-of-plane translation motion with a frequency of 0.53kHz are achieved with <60V driving voltage. Based on these results, 2D imaging with frame rate of 5 10Hz and large field of view (1000μm x 1000μm in horizontal plane and 1000μm x 400μm in vertical plane) can be enabled by this scanner.

A Multi-Scale Settlement Matching Algorithm Based on ARG

NASA Astrophysics Data System (ADS)

Yue, Han; Zhu, Xinyan; Chen, Di; Liu, Lingjia

2016-06-01

Homonymous entity matching is an important part of multi-source spatial data integration, automatic updating and change detection. Considering the low accuracy of existing matching methods in dealing with matching multi-scale settlement data, an algorithm based on Attributed Relational Graph (ARG) is proposed. The algorithm firstly divides two settlement scenes at different scales into blocks by small-scale road network and constructs local ARGs in each block. Then, ascertains candidate sets by merging procedures and obtains the optimal matching pairs by comparing the similarity of ARGs iteratively. Finally, the corresponding relations between settlements at large and small scales are identified. At the end of this article, a demonstration is presented and the results indicate that the proposed algorithm is capable of handling sophisticated cases.

Contrast effects on speed perception for linear and radial motion.

PubMed

Champion, Rebecca A; Warren, Paul A

2017-11-01

Speed perception is vital for safe activity in the environment. However, considerable evidence suggests that perceived speed changes as a function of stimulus contrast, with some investigators suggesting that this might have meaningful real-world consequences (e.g. driving in fog). In the present study we investigate whether the neural effects of contrast on speed perception occur at the level of local or global motion processing. To do this we examine both speed discrimination thresholds and contrast-dependent speed perception for two global motion configurations that have matched local spatio-temporal structure. Specifically we compare linear and radial configurations, the latter of which arises very commonly due to self-movement. In experiment 1 the stimuli comprised circular grating patches. In experiment 2, to match stimuli even more closely, motion was presented in multiple local Gabor patches equidistant from central fixation. Each patch contained identical linear motion but the global configuration was either consistent with linear or radial motion. In both experiments 1 and 2, discrimination thresholds and contrast-induced speed biases were similar in linear and radial conditions. These results suggest that contrast-based speed effects occur only at the level of local motion processing, irrespective of global structure. This result is interpreted in the context of previous models of speed perception and evidence suggesting differences in perceived speed of locally matched linear and radial stimuli. Copyright © 2017 Elsevier Ltd. All rights reserved.

Parallel implementation and evaluation of motion estimation system algorithms on a distributed memory multiprocessor using knowledge based mappings

NASA Technical Reports Server (NTRS)

Choudhary, Alok Nidhi; Leung, Mun K.; Huang, Thomas S.; Patel, Janak H.

1989-01-01

Several techniques to perform static and dynamic load balancing techniques for vision systems are presented. These techniques are novel in the sense that they capture the computational requirements of a task by examining the data when it is produced. Furthermore, they can be applied to many vision systems because many algorithms in different systems are either the same, or have similar computational characteristics. These techniques are evaluated by applying them on a parallel implementation of the algorithms in a motion estimation system on a hypercube multiprocessor system. The motion estimation system consists of the following steps: (1) extraction of features; (2) stereo match of images in one time instant; (3) time match of images from different time instants; (4) stereo match to compute final unambiguous points; and (5) computation of motion parameters. It is shown that the performance gains when these data decomposition and load balancing techniques are used are significant and the overhead of using these techniques is minimal.

Development and validation of real-time simulation of X-ray imaging with respiratory motion.

PubMed

Vidal, Franck P; Villard, Pierre-Frédéric

2016-04-01

We present a framework that combines evolutionary optimisation, soft tissue modelling and ray tracing on GPU to simultaneously compute the respiratory motion and X-ray imaging in real-time. Our aim is to provide validated building blocks with high fidelity to closely match both the human physiology and the physics of X-rays. A CPU-based set of algorithms is presented to model organ behaviours during respiration. Soft tissue deformation is computed with an extension of the Chain Mail method. Rigid elements move according to kinematic laws. A GPU-based surface rendering method is proposed to compute the X-ray image using the Beer-Lambert law. It is provided as an open-source library. A quantitative validation study is provided to objectively assess the accuracy of both components: (i) the respiration against anatomical data, and (ii) the X-ray against the Beer-Lambert law and the results of Monte Carlo simulations. Our implementation can be used in various applications, such as interactive medical virtual environment to train percutaneous transhepatic cholangiography in interventional radiology, 2D/3D registration, computation of digitally reconstructed radiograph, simulation of 4D sinograms to test tomography reconstruction tools. Copyright © 2015 Elsevier Ltd. All rights reserved.

Facial motion parameter estimation and error criteria in model-based image coding

NASA Astrophysics Data System (ADS)

Liu, Yunhai; Yu, Lu; Yao, Qingdong

2000-04-01

Model-based image coding has been given extensive attention due to its high subject image quality and low bit-rates. But the estimation of object motion parameter is still a difficult problem, and there is not a proper error criteria for the quality assessment that are consistent with visual properties. This paper presents an algorithm of the facial motion parameter estimation based on feature point correspondence and gives the motion parameter error criteria. The facial motion model comprises of three parts. The first part is the global 3-D rigid motion of the head, the second part is non-rigid translation motion in jaw area, and the third part consists of local non-rigid expression motion in eyes and mouth areas. The feature points are automatically selected by a function of edges, brightness and end-node outside the blocks of eyes and mouth. The numbers of feature point are adjusted adaptively. The jaw translation motion is tracked by the changes of the feature point position of jaw. The areas of non-rigid expression motion can be rebuilt by using block-pasting method. The estimation approach of motion parameter error based on the quality of reconstructed image is suggested, and area error function and the error function of contour transition-turn rate are used to be quality criteria. The criteria reflect the image geometric distortion caused by the error of estimated motion parameters properly.

Global form and motion processing in healthy ageing.

PubMed

Agnew, Hannah C; Phillips, Louise H; Pilz, Karin S

2016-05-01

The ability to perceive biological motion has been shown to deteriorate with age, and it is assumed that older adults rely more on the global form than local motion information when processing point-light walkers. Further, it has been suggested that biological motion processing in ageing is related to a form-based global processing bias. Here, we investigated the relationship between older adults' preference for form information when processing point-light actions and an age-related form-based global processing bias. In a first task, we asked older (>60years) and younger adults (19-23years) to sequentially match three different point-light actions; normal actions that contained local motion and global form information, scrambled actions that contained primarily local motion information, and random-position actions that contained primarily global form information. Both age groups overall performed above chance in all three conditions, and were more accurate for actions that contained global form information. For random-position actions, older adults were less accurate than younger adults but there was no age-difference for normal or scrambled actions. These results indicate that both age groups rely more on global form than local motion to match point-light actions, but can use local motion on its own to match point-light actions. In a second task, we investigated form-based global processing biases using the Navon task. In general, participants were better at discriminating the local letters but faster at discriminating global letters. Correlations showed that there was no significant linear relationship between performance in the Navon task and biological motion processing, which suggests that processing biases in form- and motion-based tasks are unrelated. Copyright © 2016. Published by Elsevier B.V.

Software Design Document SAF Simulation Host CSCI (8). Volume 1, Sections 1.0 - 2.7

DTIC Science & Technology

1991-06-01

list for the patch, testing edges matching grid-loc-woni for intervisibility blocks. Calls Function IWhere Described Icheck edges Sec. 2.6.7.1.8 Table...edges matching grid-loc-word for intervisibility blocks. Calls Function Where Described check box Sec. 2.6.7.1.31 treelines Sec. 2.6.7.1.16 Icheck edges

Automated extraction of temporal motor activity signals from video recordings of neonatal seizures based on adaptive block matching.

PubMed

Karayiannis, Nicolaos B; Sami, Abdul; Frost, James D; Wise, Merrill S; Mizrahi, Eli M

2005-04-01

This paper presents an automated procedure developed to extract quantitative information from video recordings of neonatal seizures in the form of motor activity signals. This procedure relies on optical flow computation to select anatomical sites located on the infants' body parts. Motor activity signals are extracted by tracking selected anatomical sites during the seizure using adaptive block matching. A block of pixels is tracked throughout a sequence of frames by searching for the most similar block of pixels in subsequent frames; this search is facilitated by employing various update strategies to account for the changing appearance of the block. The proposed procedure is used to extract temporal motor activity signals from video recordings of neonatal seizures and other events not associated with seizures.

A Coarse-to-Fine Geometric Scale-Invariant Feature Transform for Large Size High Resolution Satellite Image Registration

PubMed Central

Chang, Xueli; Du, Siliang; Li, Yingying; Fang, Shenghui

2018-01-01

Large size high resolution (HR) satellite image matching is a challenging task due to local distortion, repetitive structures, intensity changes and low efficiency. In this paper, a novel matching approach is proposed for the large size HR satellite image registration, which is based on coarse-to-fine strategy and geometric scale-invariant feature transform (SIFT). In the coarse matching step, a robust matching method scale restrict (SR) SIFT is implemented at low resolution level. The matching results provide geometric constraints which are then used to guide block division and geometric SIFT in the fine matching step. The block matching method can overcome the memory problem. In geometric SIFT, with area constraints, it is beneficial for validating the candidate matches and decreasing searching complexity. To further improve the matching efficiency, the proposed matching method is parallelized using OpenMP. Finally, the sensing image is rectified to the coordinate of reference image via Triangulated Irregular Network (TIN) transformation. Experiments are designed to test the performance of the proposed matching method. The experimental results show that the proposed method can decrease the matching time and increase the number of matching points while maintaining high registration accuracy. PMID:29702589

Contextual effects on preattentive processing of sound motion as revealed by spatial MMN.

PubMed

Shestopalova, L B; Petropavlovskaia, E A; Vaitulevich, S Ph; Nikitin, N I

2015-04-01

The magnitude of spatial distance between sound stimuli is critically important for their preattentive discrimination, yet the effect of stimulus context on auditory motion processing is not clear. This study investigated the effects of acoustical change and stimulus context on preattentive spatial change detection. Auditory event-related potentials (ERPs) were recorded for stationary midline noises and two patterns of sound motion produced by linear or abrupt changes of interaural time differences. Each of the three types of stimuli was used as standard or deviant in different blocks. Context effects on mismatch negativity (MMN) elicited by stationary and moving sound stimuli were investigated by reversing the role of standard and deviant stimuli, while the acoustical stimulus parameters were kept the same. That is, MMN amplitudes were calculated by subtracting ERPs to identical stimuli presented as standard in one block and deviant in another block. In contrast, effects of acoustical change on MMN amplitudes were calculated by subtracting ERPs of standards and deviants presented within the same block. Preattentive discrimination of moving and stationary sounds indexed by MMN was strongly dependent on the stimulus context. Higher MMNs were produced in oddball configurations where deviance represented increments of the sound velocity, as compared to configurations with velocity decrements. The effect of standard-deviant reversal was more pronounced with the abrupt sound displacement than with gradual sound motion. Copyright © 2015 Elsevier B.V. All rights reserved.

Global image registration using a symmetric block-matching approach

PubMed Central

Modat, Marc; Cash, David M.; Daga, Pankaj; Winston, Gavin P.; Duncan, John S.; Ourselin, Sébastien

2014-01-01

Abstract. Most medical image registration algorithms suffer from a directionality bias that has been shown to largely impact subsequent analyses. Several approaches have been proposed in the literature to address this bias in the context of nonlinear registration, but little work has been done for global registration. We propose a symmetric approach based on a block-matching technique and least-trimmed square regression. The proposed method is suitable for multimodal registration and is robust to outliers in the input images. The symmetric framework is compared with the original asymmetric block-matching technique and is shown to outperform it in terms of accuracy and robustness. The methodology presented in this article has been made available to the community as part of the NiftyReg open-source package. PMID:26158035

SU-C-207B-07: Deep Convolutional Neural Network Image Matching for Ultrasound Guidance in Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, N; Najafi, M; Hancock, S

Purpose: Robust matching of ultrasound images is a challenging problem as images of the same anatomy often present non-trivial differences. This poses an obstacle for ultrasound guidance in radiotherapy. Thus our objective is to overcome this obstacle by designing and evaluating an image blocks matching framework based on a two channel deep convolutional neural network. Methods: We extend to 3D an algorithmic structure previously introduced for 2D image feature learning [1]. To obtain the similarity between two 3D image blocks A and B, the 3D image blocks are divided into 2D patches Ai and Bi. The similarity is then calculatedmore » as the average similarity score of Ai and Bi. The neural network was then trained with public non-medical image pairs, and subsequently evaluated on ultrasound image blocks for the following scenarios: (S1) same image blocks with/without shifts (A and A-shift-x); (S2) non-related random block pairs; (S3) ground truth registration matched pairs of different ultrasound images with/without shifts (A-i and A-reg-i-shift-x). Results: For S1 the similarity scores of A and A-shift-x were 32.63, 18.38, 12.95, 9.23, 2.15 and 0.43 for x=ranging from 0 mm to 10 mm in 2 mm increments. For S2 the average similarity score for non-related block pairs was −1.15. For S3 the average similarity score of ground truth registration matched blocks A-i and A-reg-i-shift-0 (1≤i≤5) was 12.37. After translating A-reg-i-shift-0 by 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm, the average similarity scores of A-i and A-reg-i-shift-x were 11.04, 8.42, 4.56, 2.27, and 0.29 respectively. Conclusion: The proposed method correctly assigns highest similarity to corresponding 3D ultrasound image blocks despite differences in image content and thus can form the basis for ultrasound image registration and tracking.[1] Zagoruyko, Komodakis, “Learning to compare image patches via convolutional neural networks', IEEE CVPR 2015,pp.4353–4361.« less

Discriminating Rigid from Nonrigid Motion

DTIC Science & Technology

1989-07-31

motion can be given a three-dimensional interpretation using a constraint of rigidity. Kruppa’s result and others (Faugeras & Maybank , 1989; Huang...Experimental Psychology: Human Perception and Performance, 10, 1-11. Faugeras, 0., & Maybank , S. (1989). Motion from point matches: multiplicity of

Neural Correlates of Coherent and Biological Motion Perception in Autism

ERIC Educational Resources Information Center

Koldewyn, Kami; Whitney, David; Rivera, Susan M.

2011-01-01

Recent evidence suggests those with autism may be generally impaired in visual motion perception. To examine this, we investigated both coherent and biological motion processing in adolescents with autism employing both psychophysical and fMRI methods. Those with autism performed as well as matched controls during coherent motion perception but…

Coherence Motion Perception in Developmental Dyslexia: A Meta-Analysis of Behavioral Studies

ERIC Educational Resources Information Center

Benassi, Mariagrazia; Simonelli, Letizia; Giovagnoli, Sara; Bolzani, Roberto

2010-01-01

The magnitude of the association between developmental dyslexia (DD) and motion sensitivity is evaluated in 35 studies, which investigated coherence motion perception in DD. A first analysis is conducted on the differences between DD groups and age-matched control (C) groups. In a second analysis, the relationship between motion coherence…

An Efficient Method to Detect Mutual Overlap of a Large Set of Unordered Images for Structure-From

NASA Astrophysics Data System (ADS)

Wang, X.; Zhan, Z. Q.; Heipke, C.

2017-05-01

Recently, low-cost 3D reconstruction based on images has become a popular focus of photogrammetry and computer vision research. Methods which can handle an arbitrary geometric setup of a large number of unordered and convergent images are of particular interest. However, determining the mutual overlap poses a considerable challenge. We propose a new method which was inspired by and improves upon methods employing random k-d forests for this task. Specifically, we first derive features from the images and then a random k-d forest is used to find the nearest neighbours in feature space. Subsequently, the degree of similarity between individual images, the image overlaps and thus images belonging to a common block are calculated as input to a structure-from-motion (sfm) pipeline. In our experiments we show the general applicability of the new method and compare it with other methods by analyzing the time efficiency. Orientations and 3D reconstructions were successfully conducted with our overlap graphs by sfm. The results show a speed-up of a factor of 80 compared to conventional pairwise matching, and of 8 and 2 compared to the VocMatch approach using 1 and 4 CPU, respectively.

Block Tectonic Motion on Venus

NASA Astrophysics Data System (ADS)

Byrne, P. K.; Ghail, R.; Sengor, A. M. C.; Klimczak, C.; Solomon, S. C.

2017-12-01

Despite close similarities in mass and bulk composition to Earth, Venus apparently shows no evidence for Earth-like plate tectonics, except perhaps for limited plume-induced subduction. We use Magellan radar data to survey numerous examples of low-lying areas infilled with plains lavas and delimited by networks of narrow belts of substantial tectonic deformation; such sites include those at Lavinia and Llorona Planitiæ and to the north of Helen Planitia. This deformation is locally extensional or shortening in style but very often also includes structures that denote substantial lateral motion. Cross-cutting relations suggest that this motion occurred both before and after the lavas were emplaced. Together, these observations imply that many of the belt-bounded areas have acted as relatively rigid blocks that experienced considerable horizontal movement relative to each other, in a manner similar to blocks that constitute parts of the Terran continental lithosphere. On Earth, continental deformation is enabled by the low strength of the lower crust and/or upper mantle. On Venus, the shallow brittle-ductile transition (BDT), a result of the planet's elevated surface temperature, likely acts in a similar way to decouple the upper and lower crust. Subcrustal lid rejuvenation, a recently proposed mechanism for renewal of the mantle portion of Venus' stagnant lithospheric lid through thinning and recycling, could drive the horizontal movement of these rigid blocks. It may be, then, that the blocks move as continental blocks do on Earth, with mantle motion transferred to the surface and manifest as narrow zones of tectonic deformation akin to, for example, the Tian Shan and Altin Tagh ranges that bound the Tarim Basin in northwestern China. The shallow BDT on Venus precludes the blocks from subducting, and so their fate is to shorten, lengthen, or retain their geometry at the expense of adjacent blocks. We suggest that this behavior is analogous to plate-tectonic-driven continental deformation on Earth, and that this activity has operated in the regions documented on Venus since the time of emplacement of the local plains material.

Estimation of interplate coupling along Nankai trough considering the block motion model based on onland GNSS and seafloor GPS/A observation data using MCMC method

NASA Astrophysics Data System (ADS)

Kimura, H.; Ito, T.; Tadokoro, K.

2017-12-01

Introduction In southwest Japan, Philippine sea plate is subducting under the overriding plate such as Amurian plate, and mega interplate earthquakes has occurred at about 100 years interval. There is no occurrence of mega interplate earthquakes in southwest Japan, although it has passed about 70 years since the last mega interplate earthquakes: 1944 and 1946 along Nankai trough, meaning that the strain has been accumulated at plate interface. Therefore, it is essential to reveal the interplate coupling more precisely for predicting or understanding the mechanism of next occurring mega interplate earthquake. Recently, seafloor geodetic observation revealed the detailed interplate coupling distribution in expected source region of Nankai trough earthquake (e.g., Yokota et al. [2016]). In this study, we estimated interplate coupling in southwest Japan, considering block motion model and using seafloor geodetic observation data as well as onland GNSS observation data, based on Markov Chain Monte Carlo (MCMC) method. Method Observed crustal deformation is assumed that sum of rigid block motion and elastic deformation due to coupling at block boundaries. We modeled this relationship as a non-linear inverse problem that the unknown parameters are Euler pole of each block and coupling at each subfault, and solved them simultaneously based on MCMC method. Input data we used in this study are 863 onland GNSS observation data and 24 seafloor GPS/A observation data. We made some block division models based on the map of active fault tracing and selected the best model based on Akaike's Information Criterion (AIC): that is consist of 12 blocks. Result We find that the interplate coupling along Nankai trough has heterogeneous spatial distribution, strong at the depth of 0 to 20km at off Tokai region, and 0 to 30km at off Shikoku region. Moreover, we find that observed crustal deformation at off Tokai region is well explained by elastic deformation due to subducting Izu Micro Plate. We will present more details of our result, and discuss about not only interplate coupling but also rigid block motion, elastic deformation due to inland fault coupling, and resolution of estimated parameters.

Nonuniformity correction for an infrared focal plane array based on diamond search block matching.

PubMed

Sheng-Hui, Rong; Hui-Xin, Zhou; Han-Lin, Qin; Rui, Lai; Kun, Qian

2016-05-01

In scene-based nonuniformity correction algorithms, artificial ghosting and image blurring degrade the correction quality severely. In this paper, an improved algorithm based on the diamond search block matching algorithm and the adaptive learning rate is proposed. First, accurate transform pairs between two adjacent frames are estimated by the diamond search block matching algorithm. Then, based on the error between the corresponding transform pairs, the gradient descent algorithm is applied to update correction parameters. During the process of gradient descent, the local standard deviation and a threshold are utilized to control the learning rate to avoid the accumulation of matching error. Finally, the nonuniformity correction would be realized by a linear model with updated correction parameters. The performance of the proposed algorithm is thoroughly studied with four real infrared image sequences. Experimental results indicate that the proposed algorithm can reduce the nonuniformity with less ghosting artifacts in moving areas and can also overcome the problem of image blurring in static areas.

Competing with lower level opponents decreases intra-team movement synchronization and time-motion demands during pre-season soccer matches.

PubMed

Folgado, Hugo; Duarte, Ricardo; Fernandes, Orlando; Sampaio, Jaime

2014-01-01

This study aimed to quantify the time-motion demands and intra-team movement synchronization during the pre-season matches of a professional soccer team according to the opposition level. Positional data from 20 players were captured during the first half of six pre-season matches of a Portuguese first league team. Time-motion demands were measured by the total distance covered and distance covered at different speed categories. Intra-team coordination was measured by calculating the relative phase of all pairs of outfield players. Afterwards, the percentage of time spent in the -30° to 30° bin (near-in-phase mode of coordination) was calculated for each dyad as a measure of space-time movement synchronization. Movement synchronization data were analyzed for the whole team, according to each dyad average speed and by groups of similar dyadic synchronization tendencies. Then, these data were compared according to the opponent team level (first league; second league; amateurs). Time-motion demands showed no differences in total distance covered per opposition levels, while matches opposing teams of superior level revealed more distance covered at very high intensity. Competing against superior level teams implied more time in synchronized behavior for the overall displacements and displacements at higher intensities. These findings suggest that playing against higher-level opponents (1st league teams) increased time-motion demands at high intensities in tandem with intra-team movement synchronization tendencies.

FANS-3D Users Guide (ESTEP Project ER 201031)

DTIC Science & Technology

2016-08-01

governing laminar and turbulent flows in body-fitted curvilinear grids. The code employs multi-block overset ( chimera ) grids, including fully matched...governing incompressible flow in body-fitted grids. The code allows for multi-block overset ( chimera ) grids, which can be fully matched, arbitrarily...interested reader may consult the Chimera Overset Structured Mesh-Interpolation Code (COSMIC) Users’ Manual (Chen, 2009). The input file used for

Color properties of the motion detectors projecting to the goldfish tectum: I. A color matching study.

PubMed

Maximov, Vadim; Maximova, Elena; Damjanović, Ilija; Maximov, Paul

2014-09-01

Responses of direction-selective and orientation-selective motion detectors were recorded extracellularly from the axon terminals of ganglion cells in the superficial layers of the tectum opticum of immobilized goldfish, Carassius gibelio (Bloch, 1782). Color stripes or edges moving on some color background (presented on the CRT monitor with known emission spectra of its phosphors) served as stimuli. It was shown that stimuli of any color can be more or less matched with the background by varying their intensities what is indicative of color blindness of the motion detectors. Sets of stimuli which matched the background proved to represent planes in the three-dimensional color space of the goldfish. A relative contribution of different types of cones to the spectral sensitivity was estimated according to orientation of the plane of color matches. The spectral sensitivity of any motion detector was shown to be determined mainly by long-wave cones with a weak negative (opponent) contributions of middle-wave and/or short-wave ones. This resulted in reduced sensitivity in the blue-green end of the spectrum, what may be considered as an adaptation to the aquatic environment where, because of the substantial light scattering of a blue-green light, acute vision is possible only in a red region of the spectrum.

Novel techniques for data decomposition and load balancing for parallel processing of vision systems: Implementation and evaluation using a motion estimation system

NASA Technical Reports Server (NTRS)

Choudhary, Alok Nidhi; Leung, Mun K.; Huang, Thomas S.; Patel, Janak H.

1989-01-01

Computer vision systems employ a sequence of vision algorithms in which the output of an algorithm is the input of the next algorithm in the sequence. Algorithms that constitute such systems exhibit vastly different computational characteristics, and therefore, require different data decomposition techniques and efficient load balancing techniques for parallel implementation. However, since the input data for a task is produced as the output data of the previous task, this information can be exploited to perform knowledge based data decomposition and load balancing. Presented here are algorithms for a motion estimation system. The motion estimation is based on the point correspondence between the involved images which are a sequence of stereo image pairs. Researchers propose algorithms to obtain point correspondences by matching feature points among stereo image pairs at any two consecutive time instants. Furthermore, the proposed algorithms employ non-iterative procedures, which results in saving considerable amounts of computation time. The system consists of the following steps: (1) extraction of features; (2) stereo match of images in one time instant; (3) time match of images from consecutive time instants; (4) stereo match to compute final unambiguous points; and (5) computation of motion parameters.

A Bayesian model of stereopsis depth and motion direction discrimination.

PubMed

Read, J C A

2002-02-01

The extraction of stereoscopic depth from retinal disparity, and motion direction from two-frame kinematograms, requires the solution of a correspondence problem. In previous psychophysical work [Read and Eagle (2000) Vision Res 40: 3345-3358], we compared the performance of the human stereopsis and motion systems with correlated and anti-correlated stimuli. We found that, although the two systems performed similarly for narrow-band stimuli, broadband anti-correlated kinematograms produced a strong perception of reversed motion, whereas the stereograms appeared merely rivalrous. I now model these psychophysical data with a computational model of the correspondence problem based on the known properties of visual cortical cells. Noisy retinal images are filtered through a set of Fourier channels tuned to different spatial frequencies and orientations. Within each channel, a Bayesian analysis incorporating a prior preference for small disparities is used to assess the probability of each possible match. Finally, information from the different channels is combined to arrive at a judgement of stimulus disparity. Each model system--stereopsis and motion--has two free parameters: the amount of noise they are subject to, and the strength of their preference for small disparities. By adjusting these parameters independently for each system, qualitative matches are produced to psychophysical data, for both correlated and anti-correlated stimuli, across a range of spatial frequency and orientation bandwidths. The motion model is found to require much higher noise levels and a weaker preference for small disparities. This makes the motion model more tolerant of poor-quality reverse-direction false matches encountered with anti-correlated stimuli, matching the strong perception of reversed motion that humans experience with these stimuli. In contrast, the lower noise level and tighter prior preference used with the stereopsis model means that it performs close to chance with anti-correlated stimuli, in accordance with human psychophysics. Thus, the key features of the experimental data can be reproduced assuming that the motion system experiences more effective noise than the stereoscopy system and imposes a less stringent preference for small disparities.

Deformation of the Western Caribbean: Insights from Block and Geodynamic Models of Geodetic, Seismic and Geologic Data

NASA Astrophysics Data System (ADS)

La Femina, P. C.; Geirsson, H.; Kobayashi, D.

2012-12-01

Cocos - Caribbean convergence along the Middle America Trench, including subduction of the Cocos Ridge and seamount domain, and Nazca - Caribbean oblique convergence along the South Panama Deformed Belt have resulted in complex plate boundary zone deformation since Miocene - Pliocene time. Plate boundary evolution and upper plate deformation in the western Caribbean is well studied and indicates, 1) Quaternary migration of the volcanic arc toward the back-arc northwest of the Cocos Ridge; 2) Pleistocene to present northwestward motion of the Central American Fore Arc (CAFA); 3) Quaternary to present deformation within the Central Costa Rica Deformed Belt; 4) Miocene-Pliocene cessation of volcanism and uplift of the Cordillera de Talamanca inboard the ridge; 5) Quaternary to present shortening across the fore-arc Fila Costeña fold and thrust belt and back-arc North Panama Deformed Belt (NPDB); 6) Quaternary to present outer fore-arc uplift above the seamount domain (Nicoya Peninsula), and above (Osa Peninsula) and flanking (Burica Peninsula) the ridge; and 7) Quaternary to present faulting along the Sona-Azuero and Canal Discontinuity fault systems. We investigate the dynamic effects of Cocos and Nazca convergence along the entire Central American margin, and the implications on western Caribbean plate boundary evolution with a new GPS derived three-dimensional (horizontal and vertical) velocity field and kinematic block and geodynamic models. Specifically, we test the hypotheses that the Cocos Ridge is the main driver for upper plate deformation and that there is an independent Panama block. Our model results provide new Euler vectors for the CAFA and Panama block, rates of relative plate and block motions in the region, and constraints on interseismic coupling along the Middle America Trench and other major block bounding fault systems. These results are compared to existing geophysical and geologic data for the region and add insights into the rates of deformation across the regions listed above. We demonstrate that Cocos Ridge collision drives northwest-directed motion of the CAFA and the northeast-directed motion of the Panama region. The Panama region is driven into the Caribbean across the NPDB and into the Choco and North Andes blocks of northwestern South America, which are also converging with the Panama region, pushing it toward the west-northwest. Motion of the Panama region can be fit by an Euler vector suggesting that it is a rigid block, however, this is not in agreement with Quaternary faulting across the isthmus.

The JPL near-real-time VLBI system and its application to clock synchronization and earth orientation measurements

NASA Technical Reports Server (NTRS)

Callahan, P. S.; Eubanks, T. M.; Roth, M. G.; Steppe, J. A.; Esposito, P. B.

1983-01-01

The JPL near-real-time VLBI system called Block I is discussed. The hardware and software of the system are described, and the Time and Earth Motion Precision Observations (TEMPO) which utilize Block I are discussed. These observations are designed to provide interstation clock synchronization to 10 nsec and to determine earth orientation (UT1 and polar motion - UTPM) to 30 cm or better in each component. TEMPO results for clock synchronization and UTPM are presented with data from the July 1980-August 1981 analyzed using the most recent JPL solution software and source catalog. Future plans for TEMPO and Block I are discussed.

A blur-invariant local feature for motion blurred image matching

NASA Astrophysics Data System (ADS)

Tong, Qiang; Aoki, Terumasa

2017-07-01

Image matching between a blurred (caused by camera motion, out of focus, etc.) image and a non-blurred image is a critical task for many image/video applications. However, most of the existing local feature schemes fail to achieve this work. This paper presents a blur-invariant descriptor and a novel local feature scheme including the descriptor and the interest point detector based on moment symmetry - the authors' previous work. The descriptor is based on a new concept - center peak moment-like element (CPME) which is robust to blur and boundary effect. Then by constructing CPMEs, the descriptor is also distinctive and suitable for image matching. Experimental results show our scheme outperforms state of the art methods for blurred image matching

Motion-Matching: A Challenge Game to Generate Motion Concepts

ERIC Educational Resources Information Center

Schuster, David; Adams, Betty; Brookes, David; Milner-Bolotin, Marina; Undreiu, Adriana

2009-01-01

Motion is a topic that is taught from elementary grades through to university at various levels of sophistication. It is an area that can be challenging for learning in a conceptually meaningful way, and formal kinematics instruction can sometimes seem dry and boring. Thus, the nature of students' initial introduction to motion is important in…

Three-Dimensional Motion Estimation Using Shading Information in Multiple Frames

DTIC Science & Technology

1989-09-01

j. Threle-D.imensionai GO Motion Estimation U sing, Shadin g Ilnformation in Multiple Frames- IJean-Pierre Schotf MIT Artifi -cial intelligence...vision 3-D structure 3-D vision- shape from shading multiple frames 20. ABSTRACT (Cofrn11,00 an reysrf* OWd Of Rssss00n7 Ad 4111111& F~ block f)nseq See...motion and shading have been treated as two disjoint problems. On the one hand, researchers studying motion or structure from motion often assume

Scene-aware joint global and local homographic video coding

NASA Astrophysics Data System (ADS)

Peng, Xiulian; Xu, Jizheng; Sullivan, Gary J.

2016-09-01

Perspective motion is commonly represented in video content that is captured and compressed for various applications including cloud gaming, vehicle and aerial monitoring, etc. Existing approaches based on an eight-parameter homography motion model cannot deal with this efficiently, either due to low prediction accuracy or excessive bit rate overhead. In this paper, we consider the camera motion model and scene structure in such video content and propose a joint global and local homography motion coding approach for video with perspective motion. The camera motion is estimated by a computer vision approach, and camera intrinsic and extrinsic parameters are globally coded at the frame level. The scene is modeled as piece-wise planes, and three plane parameters are coded at the block level. Fast gradient-based approaches are employed to search for the plane parameters for each block region. In this way, improved prediction accuracy and low bit costs are achieved. Experimental results based on the HEVC test model show that up to 9.1% bit rate savings can be achieved (with equal PSNR quality) on test video content with perspective motion. Test sequences for the example applications showed a bit rate savings ranging from 3.7 to 9.1%.

Dynamic photoinduced realignment processes in photoresponsive block copolymer films: effects of the chain length and block copolymer architecture.

PubMed

Sano, Masami; Shan, Feng; Hara, Mitsuo; Nagano, Shusaku; Shinohara, Yuya; Amemiya, Yoshiyuki; Seki, Takahiro

2015-08-07

A series of block copolymers composed of an amorphous poly(butyl methacrylate) (PBMA) block connected with an azobenzene (Az)-containing liquid crystalline (PAz) block were synthesized by changing the chain length and polymer architecture. With these block copolymer films, the dynamic realignment process of microphase separated (MPS) cylinder arrays of PBMA in the PAz matrix induced by irradiation with linearly polarized light was studied by UV-visible absorption spectroscopy, and time-resolved grazing incidence small angle X-ray scattering (GI-SAXS) measurements using a synchrotron beam. Unexpectedly, the change in the chain length hardly affected the realignment rate. In contrast, the architecture of the AB-type diblock or the ABA-type triblock essentially altered the realignment feature. The strongly cooperative motion with an induction period before realignment was characteristic only for the diblock copolymer series, and the LPL-induced alignment change immediately started for triblock copolymers and the PAz homopolymer. Additionally, a marked acceleration in the photoinduced dynamic motions was unveiled in comparison with a thermal randomization process.

A High Spatial Resolution Depth Sensing Method Based on Binocular Structured Light

PubMed Central

Yao, Huimin; Ge, Chenyang; Xue, Jianru; Zheng, Nanning

2017-01-01

Depth information has been used in many fields because of its low cost and easy availability, since the Microsoft Kinect was released. However, the Kinect and Kinect-like RGB-D sensors show limited performance in certain applications and place high demands on accuracy and robustness of depth information. In this paper, we propose a depth sensing system that contains a laser projector similar to that used in the Kinect, and two infrared cameras located on both sides of the laser projector, to obtain higher spatial resolution depth information. We apply the block-matching algorithm to estimate the disparity. To improve the spatial resolution, we reduce the size of matching blocks, but smaller matching blocks generate lower matching precision. To address this problem, we combine two matching modes (binocular mode and monocular mode) in the disparity estimation process. Experimental results show that our method can obtain higher spatial resolution depth without loss of the quality of the range image, compared with the Kinect. Furthermore, our algorithm is implemented on a low-cost hardware platform, and the system can support the resolution of 1280 × 960, and up to a speed of 60 frames per second, for depth image sequences. PMID:28397759

Disparity, motion, and color information improve gloss constancy performance.

PubMed

Wendt, Gunnar; Faul, Franz; Ekroll, Vebjørn; Mausfeld, Rainer

2010-09-01

S. Nishida and M. Shinya (1998) found that observers have only a limited ability to recover surface-reflectance properties under changes in surface shape. Our aim in the present study was to investigate how the degree of surface-reflectance constancy depends on the availability of information that may help to infer the reflectance and shape properties of surfaces. To this end, we manipulated the availability of (i) motion-induced information (static vs. dynamic presentation), (ii) disparity information (with the levels "monocular," "surface disparity," and "surface + highlight disparity"), and (iii) color information (grayscale stimuli vs. hue differences between diffuse and specular reflections). The task of the subjects was to match the perceived lightness and glossiness between two surfaces with different spatial frequency and amplitude by manipulating the diffuse component and the exponent of the Phong lighting model in one of the surfaces. Our results indicate that all three types of information improve the constancy of glossiness matches--both in isolation and in combination. The lightness matching data only revealed an influence of motion and color information. Our results indicate, somewhat counterintuitively, that motion information has a detrimental effect on lightness constancy.

Ball catching in children with developmental coordination disorder: control of degrees of freedom.

PubMed

Utley, Andrea; Steenbergen, Bert; Astill, Sarah Louise

2007-01-01

This study investigated two-handed catching in eight children (four males, four females) aged 7 to 8 years (mean 7y 4mo [SD 3mo]) with developmental coordination disorder (DCD) and their age-matched controls (AMCs). Kinematic data were collected to examine Bernstein's (1967) notion of freezing and releasing degrees of freedom (DF). Participants were asked to catch a ball 30 times, delivered in three blocks of 10 trials. Video analysis showed that children with DCD caught significantly fewer balls than their AMCs (p< or =0.001) counterparts. Kinematic analyses showed that children with DCD exhibited smaller ranges of motion and less variable angular excursions of the elbow joints than their AMCs, and that their elbows are more rigidly coupled (p< or =0.001). These data suggest that children with DCD rigidly fix and couple their limbs to reduce the number of DF actively involved in the task.

3D noise-resistant segmentation and tracking of unknown and occluded objects using integral imaging

NASA Astrophysics Data System (ADS)

Aloni, Doron; Jung, Jae-Hyun; Yitzhaky, Yitzhak

2017-10-01

Three dimensional (3D) object segmentation and tracking can be useful in various computer vision applications, such as: object surveillance for security uses, robot navigation, etc. We present a method for 3D multiple-object tracking using computational integral imaging, based on accurate 3D object segmentation. The method does not employ object detection by motion analysis in a video as conventionally performed (such as background subtraction or block matching). This means that the movement properties do not significantly affect the detection quality. The object detection is performed by analyzing static 3D image data obtained through computational integral imaging With regard to previous works that used integral imaging data in such a scenario, the proposed method performs the 3D tracking of objects without prior information about the objects in the scene, and it is found efficient under severe noise conditions.

Learned perceptual associations influence visuomotor programming under limited conditions: kinematic consistency.

PubMed

Haffenden, Angela M; Goodale, Melvyn A

2002-12-01

Previous findings have suggested that visuomotor programming can make use of learned size information in experimental paradigms where movement kinematics are quite consistent from trial to trial. The present experiment was designed to test whether or not this conclusion could be generalized to a different manipulation of kinematic variability. As in previous work, an association was established between the size and colour of square blocks (e.g. red = large; yellow = small, or vice versa). Associating size and colour in this fashion has been shown to reliably alter the perceived size of two test blocks halfway in size between the large and small blocks: estimations of the test block matched in colour to the group of large blocks are smaller than estimations of the test block matched to the group of small blocks. Subjects grasped the blocks, and on other trials estimated the size of the blocks. These changes in perceived block size were incorporated into grip scaling only when movement kinematics were highly consistent from trial to trial; that is, when the blocks were presented in the same location on each trial. When the blocks were presented in different locations grip scaling remained true to the metrics of the test blocks despite the changes in perceptual estimates of block size. These results support previous findings suggesting that kinematic consistency facilitates the incorporation of learned perceptual information into grip scaling.

Heat Capacity of Spider Silk-like Block Copolymers

PubMed Central

Huang, Wenwen; Krishnaji, Sreevidhya; Hu, Xiao; Kaplan, David; Cebe, Peggy

2012-01-01

We synthesized and characterized a new family of di-block copolymers based on the amino acid sequences of Nephila clavipes major ampulate dragline spider silk, having the form HABn and HBAn (n=1–3), comprising an alanine-rich hydrophobic block, A, a glycine-rich hydrophilic block, B, and a histidine tag, H. The reversing heat capacities, Cp(T), for temperatures below and above the glass transition, Tg, were measured by temperature modulated differential scanning calorimetry. For the solid state, we then calculated the heat capacities of our novel block copolymers based on the vibrational motions of the constituent poly(amino acid)s, whose heat capacities are known or can be estimated from the ATHAS Data Bank. For the liquid state, the heat capacity was estimated by using the rotational and translational motions in the polymer chain. Excellent agreement was found between the measured and calculated values of the heat capacity, showing that this method can serve as a standard by which to assess the Cp for other biologically inspired block copolymers. The fraction of beta sheet crystallinity of spider silk block copolymers was also determined by using the predicted Cp, and was verified by wide angle X-ray diffraction and Fourier transform infrared spectroscopy. The glass transition temperatures of spider silk block copolymer were fitted by Kwei’s equation and the results indicate that attractive interaction exists between the A-block and B-block. PMID:23869111

Self-Paced Physics, Segment 18.

ERIC Educational Resources Information Center

New York Inst. of Tech., Old Westbury.

Eighty-seven problems are included in this volume which is arranged to match study segments 2 through 14. The subject matter is related to projectiles, simple harmonic motion, kinetic friction, multiple pulley arrangements, motion on inclined planes, circular motion, potential energy, kinetic energy, center of mass, Newton's laws, elastic and…

A novel fractal image compression scheme with block classification and sorting based on Pearson's correlation coefficient.

PubMed

Wang, Jianji; Zheng, Nanning

2013-09-01

Fractal image compression (FIC) is an image coding technology based on the local similarity of image structure. It is widely used in many fields such as image retrieval, image denoising, image authentication, and encryption. FIC, however, suffers from the high computational complexity in encoding. Although many schemes are published to speed up encoding, they do not easily satisfy the encoding time or the reconstructed image quality requirements. In this paper, a new FIC scheme is proposed based on the fact that the affine similarity between two blocks in FIC is equivalent to the absolute value of Pearson's correlation coefficient (APCC) between them. First, all blocks in the range and domain pools are chosen and classified using an APCC-based block classification method to increase the matching probability. Second, by sorting the domain blocks with respect to APCCs between these domain blocks and a preset block in each class, the matching domain block for a range block can be searched in the selected domain set in which these APCCs are closer to APCC between the range block and the preset block. Experimental results show that the proposed scheme can significantly speed up the encoding process in FIC while preserving the reconstructed image quality well.

Weighted bi-prediction for light field image coding

NASA Astrophysics Data System (ADS)

Conti, Caroline; Nunes, Paulo; Ducla Soares, Luís.

2017-09-01

Light field imaging based on a single-tier camera equipped with a microlens array - also known as integral, holoscopic, and plenoptic imaging - has currently risen up as a practical and prospective approach for future visual applications and services. However, successfully deploying actual light field imaging applications and services will require developing adequate coding solutions to efficiently handle the massive amount of data involved in these systems. In this context, self-similarity compensated prediction is a non-local spatial prediction scheme based on block matching that has been shown to achieve high efficiency for light field image coding based on the High Efficiency Video Coding (HEVC) standard. As previously shown by the authors, this is possible by simply averaging two predictor blocks that are jointly estimated from a causal search window in the current frame itself, referred to as self-similarity bi-prediction. However, theoretical analyses for motion compensated bi-prediction have suggested that it is still possible to achieve further rate-distortion performance improvements by adaptively estimating the weighting coefficients of the two predictor blocks. Therefore, this paper presents a comprehensive study of the rate-distortion performance for HEVC-based light field image coding when using different sets of weighting coefficients for self-similarity bi-prediction. Experimental results demonstrate that it is possible to extend the previous theoretical conclusions to light field image coding and show that the proposed adaptive weighting coefficient selection leads to up to 5 % of bit savings compared to the previous self-similarity bi-prediction scheme.

Adaptive temporal compressive sensing for video with motion estimation

NASA Astrophysics Data System (ADS)

Wang, Yeru; Tang, Chaoying; Chen, Yueting; Feng, Huajun; Xu, Zhihai; Li, Qi

2018-04-01

In this paper, we present an adaptive reconstruction method for temporal compressive imaging with pixel-wise exposure. The motion of objects is first estimated from interpolated images with a designed coding mask. With the help of motion estimation, image blocks are classified according to the degree of motion and reconstructed with the corresponding dictionary, which was trained beforehand. Both the simulation and experiment results show that the proposed method can obtain accurate motion information before reconstruction and efficiently reconstruct compressive video.

Plate convergence at the westernmost Philippine Sea Plate

NASA Astrophysics Data System (ADS)

Wu, Wen-Nan; Hsu, Shu-Kun; Lo, Chung-Liang; Chen, How-Wei; Ma, Kuo-Fong

2009-03-01

To understand the convergent characteristics of the westernmost plate boundary between the Philippine Sea Plate (PSP) and Eurasian Plate (EP), we have calculated the stress states of plate motion by focal mechanisms. Cataloged by the Harvard centroid moment tensor solutions (Harvard CMT) and the Broadband Array in Taiwan (BATS) moment tensor, 251 focal mechanisms are used to determine the azimuths of the principal stress axes. We first used all the data to derive the mean stress tensor of the study area. The inversion result shows that the stress regime has a maximum compression along the direction of azimuth N299°. This result is consistent with the general direction of the rigid plate motion between the PSP and EP in the study area. In order to understand the spatial variation of the regional stress pattern, we divided the study area into six sub-areas (blocks A to F) based on the feature of the free-air gravity anomaly. We compare the compressive directions obtained from the stress inversion with the plate motions calculated by the Euler pole and the Global Positioning System (GPS) analysis. As a result, the azimuth of the maximum stress axis, σ1, generally agrees with the directions of the theoretical plate motion and GPS velocity vectors except block C (Lanhsu region) and block F (Ilan plain region). The discrepancy of convergent direction near the Ilan plain region is probably caused by the rifting of the Okinawa Trough. The deviation of the σ1 azimuth in the Lanhsu region could be attributed to a southwestward extrusion of the Luzon Arc (LA) block between 21°N and 22°N whose northern boundary may be associated with the right-lateral NE-SW trending fault (i.e. Huatung Fault, HF) along the Taitung Canyon. Comparing the σ1 stress patterns between block C and block D, great strain energy along HF may not be completely released yet. Alternatively, the upper crust of block C may significantly have decoupled from its lower crust or uppermost mantle.

Counterrotating prop-fan simulations which feature a relative-motion multiblock grid decomposition enabling arbitrary time-steps

NASA Technical Reports Server (NTRS)

Janus, J. Mark; Whitfield, David L.

1990-01-01

Improvements are presented of a computer algorithm developed for the time-accurate flow analysis of rotating machines. The flow model is a finite volume method utilizing a high-resolution approximate Riemann solver for interface flux definitions. The numerical scheme is a block LU implicit iterative-refinement method which possesses apparent unconditional stability. Multiblock composite gridding is used to orderly partition the field into a specified arrangement of blocks exhibiting varying degrees of similarity. Block-block relative motion is achieved using local grid distortion to reduce grid skewness and accommodate arbitrary time step selection. A general high-order numerical scheme is applied to satisfy the geometric conservation law. An even-blade-count counterrotating unducted fan configuration is chosen for a computational study comparing solutions resulting from altering parameters such as time step size and iteration count. The solutions are compared with measured data.

In-season training periodization of professional soccer players

PubMed Central

Mendez-Villanueva, A; Martínez-Santos, R

2017-01-01

The aim of this study was to quantify the seasonal perceived respiratory and muscular training loads (i.e., sRPEres-TL and sRPEmus-TL) completed by elite-oriented young professional soccer players. Twenty-four players (20.3 ± 2.0 years) belonging to the same reserve team of a Spanish La Liga club participated in this study. Only the players that were available to train for a whole week with the team and also to play the weekly game were considered: Starters, players that participated in the match for at least 45 min and Non-Starters, players that did not participate or played less than 45 minutes in the match. The competitive period was analysed after the division into 5x6-8 week blocks and 35x1 week microcycles. Data were also analysed with respect to number of days before the immediate match. Weekly TL variation across the in-season blocks was trivial-small for both groups except between Block 2 and Block 3 (ES= moderate). Substantial TL differences (ES= small–very likely) were found between training days, the TL pattern being a progressive increase up to MD-3 followed by a decrease until MD-1. Except for the match, sRPEres-/sRPEmus-TL was very similar between Starters and Non-Starters. In summary, perceived TL across the season displayed limited variation. Coaches periodized training contents to attain the highest weekly TL 72 hours before the match to progressively unload the players between MD-3 and the match day. The data revealed that the TL arising from the weekly game was solely responsible for the observed higher weekly TL of Starters in comparison with Non-Starters. PMID:28566808

Structure from Motion

DTIC Science & Technology

1988-11-17

NOTATION 17. COSATI CODES 18. SUBJECT TERMS (Continue on reverse if ntcestary and identify by block number) FIELD GROUP SUB-GROUP ,-.:image...ambiguity in the recognition of partially occluded objects. V 1 , t : ., , ’ -, L: \\ : _ 20. DISTRIBUTION/AVAILABILITY OF ABSTRACT 21. ABSTRACT...constraints involved in the problem. More information can be found in [ 1 ]. Motion-based segmentation. Edge detection algorithms based on visual motion

Method and apparatus for biological sequence comparison

DOEpatents

Marr, T.G.; Chang, W.I.

1997-12-23

A method and apparatus are disclosed for comparing biological sequences from a known source of sequences, with a subject (query) sequence. The apparatus takes as input a set of target similarity levels (such as evolutionary distances in units of PAM), and finds all fragments of known sequences that are similar to the subject sequence at each target similarity level, and are long enough to be statistically significant. The invention device filters out fragments from the known sequences that are too short, or have a lower average similarity to the subject sequence than is required by each target similarity level. The subject sequence is then compared only to the remaining known sequences to find the best matches. The filtering member divides the subject sequence into overlapping blocks, each block being sufficiently large to contain a minimum-length alignment from a known sequence. For each block, the filter member compares the block with every possible short fragment in the known sequences and determines a best match for each comparison. The determined set of short fragment best matches for the block provide an upper threshold on alignment values. Regions of a certain length from the known sequences that have a mean alignment value upper threshold greater than a target unit score are concatenated to form a union. The current block is compared to the union and provides an indication of best local alignment with the subject sequence. 5 figs.

Method and apparatus for biological sequence comparison

DOEpatents

Marr, Thomas G.; Chang, William I-Wei

1997-01-01

A method and apparatus for comparing biological sequences from a known source of sequences, with a subject (query) sequence. The apparatus takes as input a set of target similarity levels (such as evolutionary distances in units of PAM), and finds all fragments of known sequences that are similar to the subject sequence at each target similarity level, and are long enough to be statistically significant. The invention device filters out fragments from the known sequences that are too short, or have a lower average similarity to the subject sequence than is required by each target similarity level. The subject sequence is then compared only to the remaining known sequences to find the best matches. The filtering member divides the subject sequence into overlapping blocks, each block being sufficiently large to contain a minimum-length alignment from a known sequence. For each block, the filter member compares the block with every possible short fragment in the known sequences and determines a best match for each comparison. The determined set of short fragment best matches for the block provide an upper threshold on alignment values. Regions of a certain length from the known sequences that have a mean alignment value upper threshold greater than a target unit score are concatenated to form a union. The current block is compared to the union and provides an indication of best local alignment with the subject sequence.

Motion-compensated compressed sensing for dynamic contrast-enhanced MRI using regional spatiotemporal sparsity and region tracking: Block LOw-rank Sparsity with Motion-guidance (BLOSM)

PubMed Central

Chen, Xiao; Salerno, Michael; Yang, Yang; Epstein, Frederick H.

2014-01-01

Purpose Dynamic contrast-enhanced MRI of the heart is well-suited for acceleration with compressed sensing (CS) due to its spatiotemporal sparsity; however, respiratory motion can degrade sparsity and lead to image artifacts. We sought to develop a motion-compensated CS method for this application. Methods A new method, Block LOw-rank Sparsity with Motion-guidance (BLOSM), was developed to accelerate first-pass cardiac MRI, even in the presence of respiratory motion. This method divides the images into regions, tracks the regions through time, and applies matrix low-rank sparsity to the tracked regions. BLOSM was evaluated using computer simulations and first-pass cardiac datasets from human subjects. Using rate-4 acceleration, BLOSM was compared to other CS methods such as k-t SLR that employs matrix low-rank sparsity applied to the whole image dataset, with and without motion tracking, and to k-t FOCUSS with motion estimation and compensation that employs spatial and temporal-frequency sparsity. Results BLOSM was qualitatively shown to reduce respiratory artifact compared to other methods. Quantitatively, using root mean squared error and the structural similarity index, BLOSM was superior to other methods. Conclusion BLOSM, which exploits regional low rank structure and uses region tracking for motion compensation, provides improved image quality for CS-accelerated first-pass cardiac MRI. PMID:24243528

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peryshkin, A. Yu., E-mail: alexb700@yandex.ru; Makarov, P. V., E-mail: bacardi@ispms.ru; Eremin, M. O., E-mail: bacardi@ispms.ru

An evolutionary approach proposed in [1, 2] combining the achievements of traditional macroscopic theory of solid mechanics and basic ideas of nonlinear dynamics is applied in a numerical simulation of present-day tectonic plates motion and seismic process in Central Asia. Relative values of strength parameters of rigid blocks with respect to the soft zones were characterized by the δ parameter that was varied in the numerical experiments within δ = 1.1–1.8 for different groups of the zonal-block divisibility. In general, the numerical simulations of tectonic block motion and accompanying seismic process in the model geomedium indicate that the numerical solutionsmore » of the solid mechanics equations characterize its deformation as a typical behavior of a nonlinear dynamic system under conditions of self-organized criticality.« less

Observation and analysis of high-speed human motion with frequent occlusion in a large area

NASA Astrophysics Data System (ADS)

Wang, Yuru; Liu, Jiafeng; Liu, Guojun; Tang, Xianglong; Liu, Peng

2009-12-01

The use of computer vision technology in collecting and analyzing statistics during sports matches or training sessions is expected to provide valuable information for tactics improvement. However, the measurements published in the literature so far are either unreliably documented to be used in training planning due to their limitations or unsuitable for studying high-speed motion in large area with frequent occlusions. A sports annotation system is introduced in this paper for tracking high-speed non-rigid human motion over a large playing area with the aid of motion camera, taking short track speed skating competitions as an example. The proposed system is composed of two sub-systems: precise camera motion compensation and accurate motion acquisition. In the video registration step, a distinctive invariant point feature detector (probability density grads detector) and a global parallax based matching points filter are used, to provide reliable and robust matching across a large range of affine distortion and illumination change. In the motion acquisition step, a two regions' relationship constrained joint color model and Markov chain Monte Carlo based joint particle filter are emphasized, by dividing the human body into two relative key regions. Several field tests are performed to assess measurement errors, including comparison to popular algorithms. With the help of the system presented, the system obtains position data on a 30 m × 60 m large rink with root-mean-square error better than 0.3975 m, velocity and acceleration data with absolute error better than 1.2579 m s-1 and 0.1494 m s-2, respectively.

A new UKIDSS proper motion survey and key early results, including new benchmark systems

NASA Astrophysics Data System (ADS)

Smith, L.; Lucas, P.; Burningham, B.; Jones, H.; Pinfield, D.; Smart, R.; Andrei, A.

We present a proper motion catalogue for the 1500 deg2 of 2 epoch J-band UKIDSS Large Area Survey (LAS) data, which includes 120,000 stellar sources with motions detected above the 5sigma level. Our upper limit on proper motion detection is 3\\farcs3 yr-1 and typical uncertainties are of order 10 mas yr-1 for bright sources from data with a modest 1.8-7.0 year epoch baseline. We developed a bespoke proper motion pipeline which applies a source-unique second order polynomial transformation to UKIDSS array coordinates to counter potential local non-uniformity in the focal plane. Our catalogue agrees well with the proper motion data supplied in the current WFCAM Science Archive (WSA) tenth data release (DR10) catalogue where there is overlap, and in various optical catalogues, but it benefits from some improvements, such as a larger matching radius and relative to absolute proper motion correction. We present proper motion results for 128 T dwarfs in the UKIDSS LAS and key early results of projects utilising our catalogue, in particular searches for brown dwarf benchmark systems through cross matches with existing proper motion catalogues. We report the discovery of two new T dwarf benchmark systems.

Sustained attention to objects' motion sharpens position representations: Attention to changing position and attention to motion are distinct.

PubMed

Howard, Christina J; Rollings, Victoria; Hardie, Amy

2017-06-01

In tasks where people monitor moving objects, such the multiple object tracking task (MOT), observers attempt to keep track of targets as they move amongst distracters. The literature is mixed as to whether observers make use of motion information to facilitate performance. We sought to address this by two means: first by superimposing arrows on objects which varied in their informativeness about motion direction and second by asking observers to attend to motion direction. Using a position monitoring task, we calculated mean error magnitudes as a measure of the precision with which target positions are represented. We also calculated perceptual lags versus extrapolated reports, which are the times at which positions of targets best match position reports. We find that the presence of motion information in the form of superimposed arrows made no difference to position report precision nor perceptual lag. However, when we explicitly instructed observers to attend to motion, we saw facilitatory effects on position reports and in some cases reports that best matched extrapolated rather than lagging positions for small set sizes. The results indicate that attention to changing positions does not automatically recruit attention to motion, showing a dissociation between sustained attention to changing positions and attention to motion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Patch-based frame interpolation for old films via the guidance of motion paths

NASA Astrophysics Data System (ADS)

Xia, Tianran; Ding, Youdong; Yu, Bing; Huang, Xi

2018-04-01

Due to improper preservation, traditional films will appear frame loss after digital. To deal with this problem, this paper presents a new adaptive patch-based method of frame interpolation via the guidance of motion paths. Our method is divided into three steps. Firstly, we compute motion paths between two reference frames using optical flow estimation. Then, the adaptive bidirectional interpolation with holes filled is applied to generate pre-intermediate frames. Finally, using patch match to interpolate intermediate frames with the most similar patches. Since the patch match is based on the pre-intermediate frames that contain the motion paths constraint, we show a natural and inartificial frame interpolation. We test different types of old film sequences and compare with other methods, the results prove that our method has a desired performance without hole or ghost effects.

Dry friction avalanches: experiment and theory.

PubMed

Buldyrev, Sergey V; Ferrante, John; Zypman, Fredy R

2006-12-01

Experimental evidence and theoretical models are presented supporting the conjecture that dry friction stick-slip is described by self-organized criticality. We use the data, obtained with a pin-on-disk tribometer set to measure lateral force, to examine the variation of the friction force as a function of time. We study nominally flat surfaces of matching aluminum and steel. The probability distribution of force drops follows a negative power law with exponents mu in the range 3.2-3.5. The frequency power spectrum follows a 1/f alpha pattern with alpha in the range 1-1.8. We first compare these experimental results with the well-known Robin Hood model of self-organized criticality. We find good agreement between theory and experiment for the force-drop distribution but not for the power spectrum. We explain this on a physical basis and propose a model which takes explicitly into account the stiffness and inertia of the tribometer. Specifically, we numerically solve the equation of motion of a block on a friction surface pulled by a spring and show that for certain spring constants the motion is characterized by the same power law spectrum as in experiments. We propose a physical picture relating the fluctuations of the force drops to the microscopic geometry of the surface.

Toward enhancing the distributed video coder under a multiview video codec framework

NASA Astrophysics Data System (ADS)

Lee, Shih-Chieh; Chen, Jiann-Jone; Tsai, Yao-Hong; Chen, Chin-Hua

2016-11-01

The advance of video coding technology enables multiview video (MVV) or three-dimensional television (3-D TV) display for users with or without glasses. For mobile devices or wireless applications, a distributed video coder (DVC) can be utilized to shift the encoder complexity to decoder under the MVV coding framework, denoted as multiview distributed video coding (MDVC). We proposed to exploit both inter- and intraview video correlations to enhance side information (SI) and improve the MDVC performance: (1) based on the multiview motion estimation (MVME) framework, a categorized block matching prediction with fidelity weights (COMPETE) was proposed to yield a high quality SI frame for better DVC reconstructed images. (2) The block transform coefficient properties, i.e., DCs and ACs, were exploited to design the priority rate control for the turbo code, such that the DVC decoding can be carried out with fewest parity bits. In comparison, the proposed COMPETE method demonstrated lower time complexity, while presenting better reconstructed video quality. Simulations show that the proposed COMPETE can reduce the time complexity of MVME to 1.29 to 2.56 times smaller, as compared to previous hybrid MVME methods, while the image peak signal to noise ratios (PSNRs) of a decoded video can be improved 0.2 to 3.5 dB, as compared to H.264/AVC intracoding.

The role of motion analysis in elite soccer: contemporary performance measurement techniques and work rate data.

PubMed

Carling, Christopher; Bloomfield, Jonathan; Nelsen, Lee; Reilly, Thomas

2008-01-01

The optimal physical preparation of elite soccer (association football) players has become an indispensable part of the professional game, especially due to the increased physical demands of match-play. The monitoring of players' work rate profiles during competition is now feasible through computer-aided motion analysis. Traditional methods of motion analysis were extremely labour intensive and were largely restricted to university-based research projects. Recent technological developments have meant that sophisticated systems, capable of quickly recording and processing the data of all players' physical contributions throughout an entire match, are now being used in elite club environments. In recognition of the important role that motion analysis now plays as a tool for measuring the physical performance of soccer players, this review critically appraises various motion analysis methods currently employed in elite soccer and explores research conducted using these methods. This review therefore aims to increase the awareness of both practitioners and researchers of the various motion analysis systems available, and identify practical implications of the established body of knowledge, while highlighting areas that require further exploration.

Representation of deformable motion for compression of dynamic cardiac image data

NASA Astrophysics Data System (ADS)

Weinlich, Andreas; Amon, Peter; Hutter, Andreas; Kaup, André

2012-02-01

We present a new approach for efficient estimation and storage of tissue deformation in dynamic medical image data like 3-D+t computed tomography reconstructions of human heart acquisitions. Tissue deformation between two points in time can be described by means of a displacement vector field indicating for each voxel of a slice, from which position in the previous slice at a fixed position in the third dimension it has moved to this position. Our deformation model represents the motion in a compact manner using a down-sampled potential function of the displacement vector field. This function is obtained by a Gauss-Newton minimization of the estimation error image, i. e., the difference between the current and the deformed previous slice. For lossless or lossy compression of volume slices, the potential function and the error image can afterwards be coded separately. By assuming deformations instead of translational motion, a subsequent coding algorithm using this method will achieve better compression ratios for medical volume data than with conventional block-based motion compensation known from video coding. Due to the smooth prediction without block artifacts, particularly whole-image transforms like wavelet decomposition as well as intra-slice prediction methods can benefit from this approach. We show that with discrete cosine as well as with Karhunen-Lo`eve transform the method can achieve a better energy compaction of the error image than block-based motion compensation while reaching approximately the same prediction error energy.

A Low Cost Matching Motion Estimation Sensor Based on the NIOS II Microprocessor

PubMed Central

González, Diego; Botella, Guillermo; Meyer-Baese, Uwe; García, Carlos; Sanz, Concepción; Prieto-Matías, Manuel; Tirado, Francisco

2012-01-01

This work presents the implementation of a matching-based motion estimation sensor on a Field Programmable Gate Array (FPGA) and NIOS II microprocessor applying a C to Hardware (C2H) acceleration paradigm. The design, which involves several matching algorithms, is mapped using Very Large Scale Integration (VLSI) technology. These algorithms, as well as the hardware implementation, are presented here together with an extensive analysis of the resources needed and the throughput obtained. The developed low-cost system is practical for real-time throughput and reduced power consumption and is useful in robotic applications, such as tracking, navigation using an unmanned vehicle, or as part of a more complex system. PMID:23201989

A new dry hypothesis for the formation of Martian linear gullies

USGS Publications Warehouse

Diniega, Serina; Hansen, Candice J.; McElwaine, Jim N.; Hugenholtz, C.H.; Dundas, Colin M.; McEwen, Alfred S.; Bourke, Mary C.

2013-01-01

Long, narrow grooves found on the slopes of martian sand dunes have been cited as evidence of liquid water via the hypothesis that melt-water initiated debris flows eroded channels and deposited lateral levées. However, this theory has several short-comings for explaining the observed morphology and activity of these linear gullies. We present an alternative hypothesis that is consistent with the observed morphology, location, and current activity: that blocks of CO2 ice break from over-steepened cornices as sublimation processes destabilize the surface in the spring, and these blocks move downslope, carving out levéed grooves of relatively uniform width and forming terminal pits. To test this hypothesis, we describe experiments involving water and CO2 blocks on terrestrial dunes and then compare results with the martian features. Furthermore, we present a theoretical model of the initiation of block motion due to sublimation and use this to quantitatively compare the expected behavior of blocks on the Earth and Mars. The model demonstrates that CO2 blocks can be expected to move via our proposed mechanism on the Earth and Mars, and the experiments show that the motion of these blocks will naturally create the main morphological features of linear gullies seen on Mars.

Influence of Playing a Prolonged Tennis Match on Shoulder Internal Range of Motion.

PubMed

Martin, Caroline; Kulpa, Richard; Ezanno, Felix; Delamarche, Paul; Bideau, Benoit

2016-08-01

Shoulder range of motion (ROM) deficits have been identified as an injury risk factor among tennis players. It is well known that shoulder internal rotation deficit increases with age and years of play, but there is a lack of knowledge regarding the influence of a prolonged tennis match on shoulder ROM. To examine changes in shoulder ROM during a prolonged tennis match. Descriptive laboratory study. Shoulder passive internal and external rotation ROM were measured on 8 male tennis players before, every 30 minutes during, and just after a 3-hour tennis match. Total ROM was calculated as the combination of shoulder internal and external rotations. Ball velocity on the serve was measured with a radar gun before, at midmatch, and just after the match. Decreases in shoulder internal rotation (-20.8°; P = .005), total ROM (-24.6°; P = .001), and serve velocity (-1.8 m/s; P = .002) were observed at the end of the match. No statistically significant difference was observed for shoulder external rotation after the match (P = .460). Passive shoulder internal rotation and total ROM are significantly decreased during a 3-hour tennis match. The results show that a prolonged tennis match play can modify values of shoulder ROM. © 2016 The Author(s).

A High-Speed Target-Free Vision-Based Sensor for Bus Rapid Transit Viaduct Vibration Measurements Using CMT and ORB Algorithms.

PubMed

Hu, Qijun; He, Songsheng; Wang, Shilong; Liu, Yugang; Zhang, Zutao; He, Leping; Wang, Fubin; Cai, Qijie; Shi, Rendan; Yang, Yuan

2017-06-06

Bus Rapid Transit (BRT) has become an increasing source of concern for public transportation of modern cities. Traditional contact sensing techniques during the process of health monitoring of BRT viaducts cannot overcome the deficiency that the normal free-flow of traffic would be blocked. Advances in computer vision technology provide a new line of thought for solving this problem. In this study, a high-speed target-free vision-based sensor is proposed to measure the vibration of structures without interrupting traffic. An improved keypoints matching algorithm based on consensus-based matching and tracking (CMT) object tracking algorithm is adopted and further developed together with oriented brief (ORB) keypoints detection algorithm for practicable and effective tracking of objects. Moreover, by synthesizing the existing scaling factor calculation methods, more rational approaches to reducing errors are implemented. The performance of the vision-based sensor is evaluated through a series of laboratory tests. Experimental tests with different target types, frequencies, amplitudes and motion patterns are conducted. The performance of the method is satisfactory, which indicates that the vision sensor can extract accurate structure vibration signals by tracking either artificial or natural targets. Field tests further demonstrate that the vision sensor is both practicable and reliable.

A High-Speed Target-Free Vision-Based Sensor for Bus Rapid Transit Viaduct Vibration Measurements Using CMT and ORB Algorithms

PubMed Central

Hu, Qijun; He, Songsheng; Wang, Shilong; Liu, Yugang; Zhang, Zutao; He, Leping; Wang, Fubin; Cai, Qijie; Shi, Rendan; Yang, Yuan

2017-01-01

Bus Rapid Transit (BRT) has become an increasing source of concern for public transportation of modern cities. Traditional contact sensing techniques during the process of health monitoring of BRT viaducts cannot overcome the deficiency that the normal free-flow of traffic would be blocked. Advances in computer vision technology provide a new line of thought for solving this problem. In this study, a high-speed target-free vision-based sensor is proposed to measure the vibration of structures without interrupting traffic. An improved keypoints matching algorithm based on consensus-based matching and tracking (CMT) object tracking algorithm is adopted and further developed together with oriented brief (ORB) keypoints detection algorithm for practicable and effective tracking of objects. Moreover, by synthesizing the existing scaling factor calculation methods, more rational approaches to reducing errors are implemented. The performance of the vision-based sensor is evaluated through a series of laboratory tests. Experimental tests with different target types, frequencies, amplitudes and motion patterns are conducted. The performance of the method is satisfactory, which indicates that the vision sensor can extract accurate structure vibration signals by tracking either artificial or natural targets. Field tests further demonstrate that the vision sensor is both practicable and reliable. PMID:28587275

How to push a block along a wall

NASA Technical Reports Server (NTRS)

Mason, Matthew T.

1989-01-01

Some robot tasks require manipulation of objects that may be touching other fixed objects. The effects of friction and kinematic constraint must be anticipated, and may even be exploited to accomplish the task. An example task, a dynamic analysis, and appropriate effector motions are presented. The goal is to move a rectangular block along a wall, so that one side of the block maintains contact with the wall. Two solutions that push the block along the wall are discussed.

Dynamics of Disordered PI-PtBS Diblock Copolymer

NASA Astrophysics Data System (ADS)

Watanabe, Hiroshi

2009-03-01

Viscoelastic (G^*) and dielectric (ɛ'') data were examined for a LCST-type diblock copolymer composed of polyisoprene (PI; M = 53K) and poly(p-tert- butyl styrene) (PtBS; M = 42K) blocks disordered at T <=120 C^o. Only PI had the type-A dipole parallel along the chain backbone. Thus, the ɛ'' data reflected the global motion of the PI block, while the G^* data detected the motion of the copolymer chain as a whole. Comparison of these data indicated that the PI block relaxed much faster than the PtBS block at low T and the dynamic heterogeneity due to PtBS was effectively quenched to give a frictional nonuniformity for the PI block relaxation. The ɛ'' data were thermo-rheologically complex at low T, partly due to this nonuniformity. However, the block connectivity could have also led to the complexity. For testing this effect, the ɛ'' data were reduced at the iso- frictional state defined with respect to bulk PI. In this state, the ɛ'' data of the copolymer at low and high T, respectively, were close to the data for the star-branched and linear bulk PI. Thus, the PI block appeared to be effectively tethered in space at low T thereby behaving similarly to the star arm while the PI block tended to move cooperatively with the PtBS block at high T to behave similarly to the linear PI, which led to the complexity of the ɛ'' data. The PtBS block also exhibited the complexity (noted from the G^* data), which was well correlated with the complexity of the PI block.

Blocking Strategies for Performing Entity Resolution in a Distributed Computing Environment

ERIC Educational Resources Information Center

Wang, Pei

2016-01-01

Entity resolution (ER) is an O(n[superscript 2]) problem where n is the number of records to be processed. The pair-wise nature of ER makes it impractical to perform on large datasets without the use of a technique called blocking. In blocking the records are separated into groups (called blocks) in such a way the records most likely to match are…

Domain decomposition and matching for time-domain analysis of motions of ships advancing in head sea

NASA Astrophysics Data System (ADS)

Tang, Kai; Zhu, Ren-chuan; Miao, Guo-ping; Fan, Ju

2014-08-01

A domain decomposition and matching method in the time-domain is outlined for simulating the motions of ships advancing in waves. The flow field is decomposed into inner and outer domains by an imaginary control surface, and the Rankine source method is applied to the inner domain while the transient Green function method is used in the outer domain. Two initial boundary value problems are matched on the control surface. The corresponding numerical codes are developed, and the added masses, wave exciting forces and ship motions advancing in head sea for Series 60 ship and S175 containership, are presented and verified. A good agreement has been obtained when the numerical results are compared with the experimental data and other references. It shows that the present method is more efficient because of the panel discretization only in the inner domain during the numerical calculation, and good numerical stability is proved to avoid divergence problem regarding ships with flare.

Poster — Thur Eve — 29: Characterization of Patient Immobilization for Head and Neck Cancer Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Courneyea, L; Mullins, J; Howard, M

2014-08-15

Purpose: Evaluate an immobilization system to determine its adequacy for the reduced margins required for proton therapy. Methods: Twelve head-and-neck cancer patients were immobilized for conventional photon radiotherapy and imaged with pre- and post-treatment cone beam CTs (CBCTs) for each treatment fraction. To quantify the patient positioning reproducibility, each CBCT was registered to the simulation CT offline. Registrations were performed using auto-match tools and a matching volume-of-interest (VOI) consisting of a 5mm expansion around the mandible, occipital bone, C1/C2 and C7/T1. For each registration, the bony anatomy in the VOI was evaluated for agreement with the simulation position using 3more » and 5mm margins. Registrations were initially restricted to translational corrections. If the bony anatomy did not agree with the simulation position to within 3mm or 5mm, the auto-match was repeated with 3 additional rotational corrections. Intrafraction motion was calculated as the difference between the pre- and post-treatment CBCT matches. Results: Pre-treatment patient positioning agreed with the simulation CT to within 3mm/5mm for 62%/86% of fractions using translational matching and 84%/100% of fractions when rotations were included. Intrafraction motion averaged 1.1±0.8mm, with 12% of fractions having >2mm intrafraction motion. Post-treatment positioning accuracy was 57%/84% and 80%/100% for registrations without/with rotations. For the mandible, positioning accuracy dropped from 93% pre-treatment to 82% post-treatment. Conclusion: If rotational corrections are available, the immobilization system studied created reproducible patient positioning to within 3mm for 84% of fractions. However, intrafraction motion caused additional anatomy to fall outside the 3mm margin by the end of treatment.« less

Personal Identification Using Fingernail Image Based on Correlation of Density Block

NASA Astrophysics Data System (ADS)

Noda, Mayumi; Saitoh, Fumihiko

This paper proposes an authentication using fingernail images by using the block segmentation matching. A fingernail is assumed to be a new physical character that is used for biometrics authentication. The proposed system is more effective than fingerprint authentication where psychological resistance and conformability are required. Since the block segmentation matching is useful for occlusion of an object, it is assumed to be robust to a partial change of fingernail. It is expected to enhance the difference of fingernails between persons. The experimental images of various lengths of fingernail and painted manicure were used for evaluation of system performance. The experimental results show that the proposed system obtains the sufficient accuracy to certificate individuals.

Lung motion estimation using dynamic point shifting: An innovative model based on a robust point matching algorithm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi, Jianbing, E-mail: yijianbing8@163.com; Yang, Xuan, E-mail: xyang0520@263.net; Li, Yan-Ran, E-mail: lyran@szu.edu.cn

2015-10-15

Purpose: Image-guided radiotherapy is an advanced 4D radiotherapy technique that has been developed in recent years. However, respiratory motion causes significant uncertainties in image-guided radiotherapy procedures. To address these issues, an innovative lung motion estimation model based on a robust point matching is proposed in this paper. Methods: An innovative robust point matching algorithm using dynamic point shifting is proposed to estimate patient-specific lung motion during free breathing from 4D computed tomography data. The correspondence of the landmark points is determined from the Euclidean distance between the landmark points and the similarity between the local images that are centered atmore » points at the same time. To ensure that the points in the source image correspond to the points in the target image during other phases, the virtual target points are first created and shifted based on the similarity between the local image centered at the source point and the local image centered at the virtual target point. Second, the target points are shifted by the constrained inverse function mapping the target points to the virtual target points. The source point set and shifted target point set are used to estimate the transformation function between the source image and target image. Results: The performances of the authors’ method are evaluated on two publicly available DIR-lab and POPI-model lung datasets. For computing target registration errors on 750 landmark points in six phases of the DIR-lab dataset and 37 landmark points in ten phases of the POPI-model dataset, the mean and standard deviation by the authors’ method are 1.11 and 1.11 mm, but they are 2.33 and 2.32 mm without considering image intensity, and 1.17 and 1.19 mm with sliding conditions. For the two phases of maximum inhalation and maximum exhalation in the DIR-lab dataset with 300 landmark points of each case, the mean and standard deviation of target registration errors on the 3000 landmark points of ten cases by the authors’ method are 1.21 and 1.04 mm. In the EMPIRE10 lung registration challenge, the authors’ method ranks 24 of 39. According to the index of the maximum shear stretch, the authors’ method is also efficient to describe the discontinuous motion at the lung boundaries. Conclusions: By establishing the correspondence of the landmark points in the source phase and the other target phases combining shape matching and image intensity matching together, the mismatching issue in the robust point matching algorithm is adequately addressed. The target registration errors are statistically reduced by shifting the virtual target points and target points. The authors’ method with consideration of sliding conditions can effectively estimate the discontinuous motion, and the estimated motion is natural. The primary limitation of the proposed method is that the temporal constraints of the trajectories of voxels are not introduced into the motion model. However, the proposed method provides satisfactory motion information, which results in precise tumor coverage by the radiation dose during radiotherapy.« less

Lung motion estimation using dynamic point shifting: An innovative model based on a robust point matching algorithm.

PubMed

Yi, Jianbing; Yang, Xuan; Chen, Guoliang; Li, Yan-Ran

2015-10-01

Image-guided radiotherapy is an advanced 4D radiotherapy technique that has been developed in recent years. However, respiratory motion causes significant uncertainties in image-guided radiotherapy procedures. To address these issues, an innovative lung motion estimation model based on a robust point matching is proposed in this paper. An innovative robust point matching algorithm using dynamic point shifting is proposed to estimate patient-specific lung motion during free breathing from 4D computed tomography data. The correspondence of the landmark points is determined from the Euclidean distance between the landmark points and the similarity between the local images that are centered at points at the same time. To ensure that the points in the source image correspond to the points in the target image during other phases, the virtual target points are first created and shifted based on the similarity between the local image centered at the source point and the local image centered at the virtual target point. Second, the target points are shifted by the constrained inverse function mapping the target points to the virtual target points. The source point set and shifted target point set are used to estimate the transformation function between the source image and target image. The performances of the authors' method are evaluated on two publicly available DIR-lab and POPI-model lung datasets. For computing target registration errors on 750 landmark points in six phases of the DIR-lab dataset and 37 landmark points in ten phases of the POPI-model dataset, the mean and standard deviation by the authors' method are 1.11 and 1.11 mm, but they are 2.33 and 2.32 mm without considering image intensity, and 1.17 and 1.19 mm with sliding conditions. For the two phases of maximum inhalation and maximum exhalation in the DIR-lab dataset with 300 landmark points of each case, the mean and standard deviation of target registration errors on the 3000 landmark points of ten cases by the authors' method are 1.21 and 1.04 mm. In the EMPIRE10 lung registration challenge, the authors' method ranks 24 of 39. According to the index of the maximum shear stretch, the authors' method is also efficient to describe the discontinuous motion at the lung boundaries. By establishing the correspondence of the landmark points in the source phase and the other target phases combining shape matching and image intensity matching together, the mismatching issue in the robust point matching algorithm is adequately addressed. The target registration errors are statistically reduced by shifting the virtual target points and target points. The authors' method with consideration of sliding conditions can effectively estimate the discontinuous motion, and the estimated motion is natural. The primary limitation of the proposed method is that the temporal constraints of the trajectories of voxels are not introduced into the motion model. However, the proposed method provides satisfactory motion information, which results in precise tumor coverage by the radiation dose during radiotherapy.

Motion of a curved vortex filament with decaying vortical core and axial velocity

NASA Technical Reports Server (NTRS)

Callegari, A. J.; Ting, L.

1978-01-01

The motion and decay of a curved vortex filament having large axial and circumferential velocity components in a three-dimensional stream are analyzed by using the method of matched asymptotic expansions of the incompressible Navier-Stokes equations. The small parameter is the square root of the ratio of the kinematic viscosity to the circulation. The outer region is analyzed by the classical Biot-Savart law, and its solution is matched to that of the inner region, where viscous effects are important. Equations describing the coupling between the inner vortex structure and the motion of the vortex filament as well as the time evolution of the inner vortex structure are obtained. Equations are derived for the motion of the vortex filament and for the change and decay in time and space of the leading-order circumferential and axial velocity and vorticity components. Solutions are constructed for these components in terms of initial data.

Balancing the plate motion budget in the South Island, New Zealand using GPS, geological and seismological data

NASA Astrophysics Data System (ADS)

Wallace, Laura M.; Beavan, John; McCaffrey, Robert; Berryman, Kelvin; Denys, Paul

2007-01-01

The landmass of New Zealand exists as a consequence of transpressional collision between the Australian and Pacific plates, providing an excellent opportunity to quantify the kinematics of deformation at this type of tectonic boundary. We interpret GPS, geological and seismological data describing the active deformation in the South Island, New Zealand by using an elastic, rotating block approach that automatically balances the Pacific/Australia relative plate motion budget. The data in New Zealand are fit to within uncertainty when inverted simultaneously for angular velocities of rotating tectonic blocks and the degree of coupling on faults bounding the blocks. We find that most of the plate motion budget has been accounted for in previous geological studies, although we suggest that the Porter's Pass/Amberley fault zone in North Canterbury, and a zone of faults in the foothills of the Southern Alps may have slip rates about twice that of the geological estimates. Up to 5 mm yr-1 of active deformation on faults distributed within the Southern Alps <100 km to the east of the Alpine Fault is possible. The role of tectonic block rotations in partitioning plate boundary deformation is less pronounced in the South Island compared to the North Island. Vertical axis rotation rates of tectonic blocks in the South Island are similar to that of the Pacific Plate, suggesting that edge forces dominate the block kinematics there. The southward migrating Chatham Rise exerts a major influence on the evolution of the New Zealand plate boundary; we discuss a model for the development of the Marlborough fault system and Hikurangi subduction zone in the context of this migration.

Dynamic Simulation and Static Matching for Action Prediction: Evidence from Body Part Priming

ERIC Educational Resources Information Center

Springer, Anne; Brandstadter, Simone; Prinz, Wolfgang

2013-01-01

Accurately predicting other people's actions may involve two processes: internal real-time simulation (dynamic updating) and matching recently perceived action images (static matching). Using a priming of body parts, this study aimed to differentiate the two processes. Specifically, participants played a motion-controlled video game with…

Reminder about potentially serious problems with a type of blocked ANOVA analysis

Treesearch

Steve Verrill; David E. Kretschmann

2017-01-01

A type of blocked experiment has the potential of being poorly designed and/or analyzed. Verrill (1993, 1999) and Verrill et al. (2004) referred to such an experiment as a “predictor sort” experiment. David and Gunnink (1997) described the procedure as “artificial pairing.” In textbooks it is sometimes referred to as a “matched pair” or a “matched...

Feasibility Study to Evaluate Candidate Materials of Nanofilled Block Copolymers for Use in Ultra High Density Pulsed Power Capacitors

DTIC Science & Technology

2015-10-26

grafting block copolymer (BCP) to nanoparticles (BCP-g-NPs) to chemically match the corona of NPs with BCP matrix has resulted in a highly dispersed BCP...strategy of grafting BCP to nanoparticles in order to chemically match the corona of nanoparticles with BCP matrix has resulted in a highly dispersed...fast energy storage and discharge capabilities. However, the energy storage density of these capacitors is limited by the dielectric properties of

Impedance Matched Absorptive Thermal Blocking Filters

NASA Technical Reports Server (NTRS)

Wollack, E. J.; Chuss, D. T.; U-Yen, K.; Rostem, K.

2014-01-01

We have designed, fabricated and characterized absorptive thermal blocking filters for cryogenic microwave applications. The transmission line filter's input characteristic impedance is designed to match 50 Omega and its response has been validated from 0-to-50GHz. The observed return loss in the 0-to-20GHz design band is greater than 20 dB and shows graceful degradation with frequency. Design considerations and equations are provided that enable this approach to be scaled and modified for use in other applications.

Impedance Matched Absorptive Thermal Blocking Filters

NASA Technical Reports Server (NTRS)

Wollack, E. J.; Chuss, D. T.; Rostem, K.; U-Yen, K.

2014-01-01

We have designed, fabricated and characterized absorptive thermal blocking filters for cryogenic microwave applications. The transmission line filter's input characteristic impedance is designed to match 50O and its response has been validated from 0-to-50GHz. The observed return loss in the 0-to-20GHz design band is greater than 20 dB and shows graceful degradation with frequency. Design considerations and equations are provided that enable this approach to be scaled and modified for use in other applications.

Recognizing human actions by learning and matching shape-motion prototype trees.

PubMed

Jiang, Zhuolin; Lin, Zhe; Davis, Larry S

2012-03-01

A shape-motion prototype-based approach is introduced for action recognition. The approach represents an action as a sequence of prototypes for efficient and flexible action matching in long video sequences. During training, an action prototype tree is learned in a joint shape and motion space via hierarchical K-means clustering and each training sequence is represented as a labeled prototype sequence; then a look-up table of prototype-to-prototype distances is generated. During testing, based on a joint probability model of the actor location and action prototype, the actor is tracked while a frame-to-prototype correspondence is established by maximizing the joint probability, which is efficiently performed by searching the learned prototype tree; then actions are recognized using dynamic prototype sequence matching. Distance measures used for sequence matching are rapidly obtained by look-up table indexing, which is an order of magnitude faster than brute-force computation of frame-to-frame distances. Our approach enables robust action matching in challenging situations (such as moving cameras, dynamic backgrounds) and allows automatic alignment of action sequences. Experimental results demonstrate that our approach achieves recognition rates of 92.86 percent on a large gesture data set (with dynamic backgrounds), 100 percent on the Weizmann action data set, 95.77 percent on the KTH action data set, 88 percent on the UCF sports data set, and 87.27 percent on the CMU action data set.

Biological Motion Primes the Animate/Inanimate Distinction in Infancy

PubMed Central

Poulin-Dubois, Diane; Crivello, Cristina; Wright, Kristyn

2015-01-01

Given that biological motion is both detected and preferred early in life, we tested the hypothesis that biological motion might be instrumental to infants’ differentiation of animate and inanimate categories. Infants were primed with either point-light displays of realistic biological motion, random motion, or schematic biological motion of an unfamiliar shape. After being habituated to these displays, 12-month-old infants categorized animals and vehicles as well as furniture and vehicles with the sequential touching task. The findings indicated that infants primed with point-light displays of realistic biological motion showed better categorization of animates than those exposed to random or schematic biological motion. These results suggest that human biological motion might be one of the motion cues that provide the building blocks for infants’ concept of animacy. PMID:25659077

30 CFR 56.14105 - Procedures during repairs or maintenance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14105 Procedures during repairs or maintenance. Repairs or maintenance of machinery or equipment shall be performed only after the power is off, and the machinery or equipment blocked against hazardous motion. Machinery or equipment motion or...

30 CFR 56.14105 - Procedures during repairs or maintenance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14105 Procedures during repairs or maintenance. Repairs or maintenance of machinery or equipment shall be performed only after the power is off, and the machinery or equipment blocked against hazardous motion. Machinery or equipment motion or...

30 CFR 56.14105 - Procedures during repairs or maintenance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14105 Procedures during repairs or maintenance. Repairs or maintenance of machinery or equipment shall be performed only after the power is off, and the machinery or equipment blocked against hazardous motion. Machinery or equipment motion or...

30 CFR 56.14105 - Procedures during repairs or maintenance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14105 Procedures during repairs or maintenance. Repairs or maintenance of machinery or equipment shall be performed only after the power is off, and the machinery or equipment blocked against hazardous motion. Machinery or equipment motion or...

30 CFR 56.14105 - Procedures during repairs or maintenance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14105 Procedures during repairs or maintenance. Repairs or maintenance of machinery or equipment shall be performed only after the power is off, and the machinery or equipment blocked against hazardous motion. Machinery or equipment motion or...

Influence of Visual Motion, Suggestion, and Illusory Motion on Self-Motion Perception in the Horizontal Plane.

PubMed

Rosenblatt, Steven David; Crane, Benjamin Thomas

2015-01-01

A moving visual field can induce the feeling of self-motion or vection. Illusory motion from static repeated asymmetric patterns creates a compelling visual motion stimulus, but it is unclear if such illusory motion can induce a feeling of self-motion or alter self-motion perception. In these experiments, human subjects reported the perceived direction of self-motion for sway translation and yaw rotation at the end of a period of viewing set visual stimuli coordinated with varying inertial stimuli. This tested the hypothesis that illusory visual motion would influence self-motion perception in the horizontal plane. Trials were arranged into 5 blocks based on stimulus type: moving star field with yaw rotation, moving star field with sway translation, illusory motion with yaw, illusory motion with sway, and static arrows with sway. Static arrows were used to evaluate the effect of cognitive suggestion on self-motion perception. Each trial had a control condition; the illusory motion controls were altered versions of the experimental image, which removed the illusory motion effect. For the moving visual stimulus, controls were carried out in a dark room. With the arrow visual stimulus, controls were a gray screen. In blocks containing a visual stimulus there was an 8s viewing interval with the inertial stimulus occurring over the final 1s. This allowed measurement of the visual illusion perception using objective methods. When no visual stimulus was present, only the 1s motion stimulus was presented. Eight women and five men (mean age 37) participated. To assess for a shift in self-motion perception, the effect of each visual stimulus on the self-motion stimulus (cm/s) at which subjects were equally likely to report motion in either direction was measured. Significant effects were seen for moving star fields for both translation (p = 0.001) and rotation (p<0.001), and arrows (p = 0.02). For the visual motion stimuli, inertial motion perception was shifted in the direction consistent with the visual stimulus. Arrows had a small effect on self-motion perception driven by a minority of subjects. There was no significant effect of illusory motion on self-motion perception for either translation or rotation (p>0.1 for both). Thus, although a true moving visual field can induce self-motion, results of this study show that illusory motion does not.

Molecular Dynamics Study of Polystyrene-b-poly(ethylene oxide) Asymmetric Diblock Copolymer Systems.

PubMed

Dobies, M; Makrocka-Rydzyk, M; Jenczyk, J; Jarek, M; Spontak, R J; Jurga, S

2017-09-12

Two polystyrene-b-poly(ethylene oxide) (PS-b-PEO) diblock copolymers differing in molecular mass (49 and 78 kDa) but possessing the same PEO cylindrical morphology are examined to elucidate their molecular dynamics. Of particular interest here is the molecular motion of the PEO blocks involved in the rigid amorphous fraction (RAF). An analysis of complementary thermal calorimetry and X-ray scattering data confirms the presence of microphase-separated morphology as well as semicrystalline structure in each copolymer. Molecular motion within the copolymer systems is monitored by dielectric and nuclear magnetic resonance spectroscopies. The results reported herein reveal the existence of two local Arrhenius-type processes attributed to the noncooperative local motion of PEO segments involved in fully amorphous and rigid amorphous PEO microphases. In both systems, two structural relaxations governed by glass-transition phenomena are identified and assigned to cooperative segmental motion in the fully amorphous phase (the α process) and the RAF (the α c process). We measure the temperature dependence of the dynamics associated with all of the processes mentioned above and propose that these local processes are associated with corresponding cooperative segmental motion in both copolymer systems. In marked contrast to the thermal activation of the α process as discerned in both copolymers, the α c process appears to be a sensitive probe of the copolymer nanostructure. That is, the copolymer with shorter PEO blocks exhibits more highly restricted cooperative dynamics of PEO segments in the RAF, which can be explained in terms of the greater constraint imposed by the glassy PS matrix on the PEO blocks comprising smaller cylindrical microdomains.

Northward migration of the Cascadia forearc in the northwestern U.S. and implications for subduction deformation

USGS Publications Warehouse

Wells, R.E.; Simpson, R.W.

2001-01-01

Geologic and paleomagnetic data from the Cascadia forearc indicate long-term northward migration and clockwise rotation of an Oregon coastal block with respect to North America. Paleomagnetic rotation of coastal Oregon is linked by a Klamath Mountains pole to geodetically and geologically determined motion of the Sierra Nevada block to derive a new Oregon Coast-North America (OC-NA) pole of rotation and velocity field. This long-term velocity field, which is independent of Pacific Northwest GPS data, is interpreted to be the result of Basin-Range extension and Pacific-North America dextral shear. The resulting Oregon Coast pole compares favorably to those derived solely from GPS data, although uncertainties are large. Subtracting the long-term motion from forearc GPS velocities reveals ENE motion with respect to an OC reference frame that is parallel to the direction of Juan de Fuca-OC convergence and decreases inland. We interpret this to be largely the result of subduction-related deformation. The adjusted mean GPS velocities are generally subparallel to those predicted from elastic dislocation models for Cascadia, but more definitive interpretations await refinement of the present large uncertainty in the Sierra Nevada block motion. Copyright ?? The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences.

Design and analysis of multihypothesis motion-compensated prediction (MHMCP) codec for error-resilient visual communications

NASA Astrophysics Data System (ADS)

Kung, Wei-Ying; Kim, Chang-Su; Kuo, C.-C. Jay

2004-10-01

A multi-hypothesis motion compensated prediction (MHMCP) scheme, which predicts a block from a weighted superposition of more than one reference blocks in the frame buffer, is proposed and analyzed for error resilient visual communication in this research. By combining these reference blocks effectively, MHMCP can enhance the error resilient capability of compressed video as well as achieve a coding gain. In particular, we investigate the error propagation effect in the MHMCP coder and analyze the rate-distortion performance in terms of the hypothesis number and hypothesis coefficients. It is shown that MHMCP suppresses the short-term effect of error propagation more effectively than the intra refreshing scheme. Simulation results are given to confirm the analysis. Finally, several design principles for the MHMCP coder are derived based on the analytical and experimental results.

Automatic generation of endocardial surface meshes with 1-to-1 correspondence from cine-MR images

NASA Astrophysics Data System (ADS)

Su, Yi; Teo, S.-K.; Lim, C. W.; Zhong, L.; Tan, R. S.

2015-03-01

In this work, we develop an automatic method to generate a set of 4D 1-to-1 corresponding surface meshes of the left ventricle (LV) endocardial surface which are motion registered over the whole cardiac cycle. These 4D meshes have 1- to-1 point correspondence over the entire set, and is suitable for advanced computational processing, such as shape analysis, motion analysis and finite element modelling. The inputs to the method are the set of 3D LV endocardial surface meshes of the different frames/phases of the cardiac cycle. Each of these meshes is reconstructed independently from border-delineated MR images and they have no correspondence in terms of number of vertices/points and mesh connectivity. To generate point correspondence, the first frame of the LV mesh model is used as a template to be matched to the shape of the meshes in the subsequent phases. There are two stages in the mesh correspondence process: (1) a coarse matching phase, and (2) a fine matching phase. In the coarse matching phase, an initial rough matching between the template and the target is achieved using a radial basis function (RBF) morphing process. The feature points on the template and target meshes are automatically identified using a 16-segment nomenclature of the LV. In the fine matching phase, a progressive mesh projection process is used to conform the rough estimate to fit the exact shape of the target. In addition, an optimization-based smoothing process is used to achieve superior mesh quality and continuous point motion.

Slicing up the San Francisco Bay Area: Block kinematics and fault slip rates from GPS-derived surface velocities

USGS Publications Warehouse

d'Alessio, M. A.; Johanson, I.A.; Burgmann, R.; Schmidt, D.A.; Murray, M.H.

2005-01-01

Observations of surface deformation allow us to determine the kinematics of faults in the San Francisco Bay Area. We present the Bay Area velocity unification (BA??VU??, "bay view"), a compilation of over 200 horizontal surface velocities computed from campaign-style and continuous Global Positioning System (GPS) observations from 1993 to 2003. We interpret this interseismic velocity field using a three-dimensional block model to determine the relative contributions of block motion, elastic strain accumulation, and shallow aseismic creep. The total relative motion between the Pacific plate and the rigid Sierra Nevada/Great Valley (SNGV) microplate is 37.9 ?? 0.6 mm yr-1 directed toward N30.4??W ?? 0.8?? at San Francisco (??2??). Fault slip rates from our preferred model are typically within the error bounds of geologic estimates but provide a better fit to geodetic data (notable right-lateral slip rates in mm yr-1: San Gregorio fault, 2.4 ?? 1.0; West Napa fault, 4.0 ?? 3.0; zone of faulting along the eastern margin of the Coast Range, 5.4 ?? 1.0; and Mount Diablo thrust, 3.9 ?? 1.0 of reverse slip and 4.0 ?? 0.2 of right-lateral strike slip). Slip on the northern Calaveras is partitioned between both the West Napa and Concord/ Green Valley fault systems. The total convergence across the Bay Area is negligible. Poles of rotation for Bay Area blocks progress systematically from the North America-Pacific to North America-SNGV poles. The resulting present-day relative motion cannot explain the strike of most Bay Area faults, but fault strike does loosely correlate with inferred plate motions at the time each fault initiated. Copyright 2005 by the American Geophysical Union.

Simultaneous two-view epipolar geometry estimation and motion segmentation by 4D tensor voting.

PubMed

Tong, Wai-Shun; Tang, Chi-Keung; Medioni, Gérard

2004-09-01

We address the problem of simultaneous two-view epipolar geometry estimation and motion segmentation from nonstatic scenes. Given a set of noisy image pairs containing matches of n objects, we propose an unconventional, efficient, and robust method, 4D tensor voting, for estimating the unknown n epipolar geometries, and segmenting the static and motion matching pairs into n independent motions. By considering the 4D isotropic and orthogonal joint image space, only two tensor voting passes are needed, and a very high noise to signal ratio (up to five) can be tolerated. Epipolar geometries corresponding to multiple, rigid motions are extracted in succession. Only two uncalibrated frames are needed, and no simplifying assumption (such as affine camera model or homographic model between images) other than the pin-hole camera model is made. Our novel approach consists of propagating a local geometric smoothness constraint in the 4D joint image space, followed by global consistency enforcement for extracting the fundamental matrices corresponding to independent motions. We have performed extensive experiments to compare our method with some representative algorithms to show that better performance on nonstatic scenes are achieved. Results on challenging data sets are presented.

Dissociation between Semantic Representations for Motion and Action Verbs: Evidence from Patients with Left Hemisphere Lesions

PubMed Central

Taylor, Lawrence J.; Evans, Carys; Greer, Joanna; Senior, Carl; Coventry, Kenny R.; Ietswaart, Magdalena

2017-01-01

This multiple single case study contrasted left hemisphere stroke patients (N = 6) to healthy age-matched control participants (N = 15) on their understanding of action (e.g., holding, clenching) and motion verbs (e.g., crumbling, flowing). The tasks required participants to correctly identify the matching verb or associated picture. Dissociations on action and motion verb content depending on lesion site were expected. As predicted for verbs containing an action and/or motion content, modified t-tests confirmed selective deficits in processing motion verbs in patients with lesions involving posterior parietal and lateral occipitotemporal cortex. In contrast, deficits in verbs describing motionless actions were found in patients with more anterior lesions sparing posterior parietal and lateral occipitotemporal cortex. These findings support the hypotheses that semantic representations for action and motion are behaviorally and neuro-anatomically dissociable. The findings clarify the differential and critical role of perceptual and motor regions in processing modality-specific semantic knowledge as opposed to a supportive but not necessary role. We contextualize these results within theories from both cognitive psychology and cognitive neuroscience that make claims over the role of sensory and motor information in semantic representation. PMID:28261070

The Effect of a Commercial Game on Children's Block Design Scores on the WISC-R IQ Test.

ERIC Educational Resources Information Center

Dirks, Jean

1982-01-01

Relatively brief interactions with a commercial game that involved blocks and matching patterns are shown to cause a significant improvement in children's performances on the WISC-R Block Design subtest. Two experiments are described using 10-year-old children in game and no-game conditions. (Author/CM)

Incompressible Deformation Estimation Algorithm (IDEA) from Tagged MR Images

PubMed Central

Liu, Xiaofeng; Abd-Elmoniem, Khaled Z.; Stone, Maureen; Murano, Emi Z.; Zhuo, Jiachen; Gullapalli, Rao P.; Prince, Jerry L.

2013-01-01

Measuring the three-dimensional motion of muscular tissues, e.g., the heart or the tongue, using magnetic resonance (MR) tagging is typically carried out by interpolating the two-dimensional motion information measured on orthogonal stacks of images. The incompressibility of muscle tissue is an important constraint on the reconstructed motion field and can significantly help to counter the sparsity and incompleteness of the available motion information. Previous methods utilizing this fact produced incompressible motions with limited accuracy. In this paper, we present an incompressible deformation estimation algorithm (IDEA) that reconstructs a dense representation of the three-dimensional displacement field from tagged MR images and the estimated motion field is incompressible to high precision. At each imaged time frame, the tagged images are first processed to determine components of the displacement vector at each pixel relative to the reference time. IDEA then applies a smoothing, divergence-free, vector spline to interpolate velocity fields at intermediate discrete times such that the collection of velocity fields integrate over time to match the observed displacement components. Through this process, IDEA yields a dense estimate of a three-dimensional displacement field that matches our observations and also corresponds to an incompressible motion. The method was validated with both numerical simulation and in vivo human experiments on the heart and the tongue. PMID:21937342

The Effects of Opposition and Gender on Knee Kinematics and Ground Reaction Force during Landing from Volleyball Block Jumps

ERIC Educational Resources Information Center

Hughes, Gerwyn; Watkins, James; Owen, Nick

2010-01-01

The aim of this study was to examine the effect of opposition and gender on knee kinematics and ground reaction force during landing from a volleyball block jump. Six female and six male university volleyball players performed two landing tasks: (a) an unopposed and (b) an opposed volleyball block jump and landing. A 12-camera motion analysis…

Validation of an inertial measurement unit for the measurement of jump count and height.

PubMed

MacDonald, Kerry; Bahr, Roald; Baltich, Jennifer; Whittaker, Jackie L; Meeuwisse, Willem H

2017-05-01

To validate the use of an inertial measurement unit (IMU) for the collection of total jump count and assess the validity of an IMU for the measurement of jump height against 3-D motion analysis. Cross sectional validation study. 3D motion-capture laboratory and field based settings. Thirteen elite adolescent volleyball players. Participants performed structured drills, played a 4 set volleyball match and performed twelve counter movement jumps. Jump counts from structured drills and match play were validated against visual count from recorded video. Jump height during the counter movement jumps was validated against concurrent 3-D motion-capture data. The IMU device captured more total jumps (1032) than visual inspection (977) during match play. During structured practice, device jump count sensitivity was strong (96.8%) while specificity was perfect (100%). The IMU underestimated jump height compared to 3D motion-capture with mean differences for maximal and submaximal jumps of 2.5 cm (95%CI: 1.3 to 3.8) and 4.1 cm (3.1-5.1), respectively. The IMU offers a valid measuring tool for jump count. Although the IMU underestimates maximal and submaximal jump height, our findings demonstrate its practical utility for field-based measurement of jump load. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermoreversible networks for moldable photo-responsive elastomers (Presentation Recording)

NASA Astrophysics Data System (ADS)

Kornfield, Julia A.; Kurji, Zuleikha

2015-10-01

Soft-solids that retain the responsive optical anisotropy of liquid crystals (LC) can be used as mechano-optical, electro-optical and electro-mechanical elements. We use self-assembly of block copolymers to create reversible LC gels and elastomers that flow at elevated temperatures and physically cross link upon cooling. In the melt, they can be spun, coated or molded. Segregation of the end-blocks forms uniform and uniformly spaced crosslinks. Matched sets of block copolymers are synthesized from a single "prepolymer." Specifically, we begin with polymers having polystyrene (PS) end blocks and a poly(1,2-butadiene) midblock. The pendant vinyl groups along the backbone of the midblock are used to graft mesogens, converting it to a side-group LC polymer (SGLCP). In the present case, cyanobiphenyl groups are used as the nonphotoresponsive mesogens and azobenzene groups are used as photoresponsive mesogens. Here we show that matched pairs of block copolymers, with and without photo-responsive mesogens, provide model systems in which the optical density can be adjusted while holding other properties fixed (cross-link density, modulus, birefringence, isotropic-nematic transition temperature). For example, a triblock in which the SGLCP block has 95% cyanobiphenyl and 5% azo side groups is miscible with one having 100% cyanobiphenyl side groups. Simply blending the two gives a series of LC elastomers that have from 0 to 5% azo, while having all other physical properties matched. Results will be presented that show the outcomesof this approach to systematic and largely independent control of optical density and photo-mechanical sensitivity.

30 CFR 75.1725 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... machinery until the power is off and the machinery is blocked against motion, except where machinery motion... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machinery and equipment; operation and....1725 Machinery and equipment; operation and maintenance. (a) Mobile and stationary machinery and...

30 CFR 77.404 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the power is off and the machinery is blocked against motion, except where machinery motion is... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Machinery and equipment; operation and... OF UNDERGROUND COAL MINES Safeguards for Mechanical Equipment § 77.404 Machinery and equipment...

30 CFR 75.1725 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... machinery until the power is off and the machinery is blocked against motion, except where machinery motion... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Machinery and equipment; operation and....1725 Machinery and equipment; operation and maintenance. (a) Mobile and stationary machinery and...

30 CFR 75.1725 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... machinery until the power is off and the machinery is blocked against motion, except where machinery motion... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Machinery and equipment; operation and....1725 Machinery and equipment; operation and maintenance. (a) Mobile and stationary machinery and...

30 CFR 75.1725 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... machinery until the power is off and the machinery is blocked against motion, except where machinery motion... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Machinery and equipment; operation and....1725 Machinery and equipment; operation and maintenance. (a) Mobile and stationary machinery and...

30 CFR 77.404 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the power is off and the machinery is blocked against motion, except where machinery motion is... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machinery and equipment; operation and... OF UNDERGROUND COAL MINES Safeguards for Mechanical Equipment § 77.404 Machinery and equipment...

30 CFR 75.1725 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... machinery until the power is off and the machinery is blocked against motion, except where machinery motion... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Machinery and equipment; operation and....1725 Machinery and equipment; operation and maintenance. (a) Mobile and stationary machinery and...

30 CFR 77.404 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the power is off and the machinery is blocked against motion, except where machinery motion is... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Machinery and equipment; operation and... OF UNDERGROUND COAL MINES Safeguards for Mechanical Equipment § 77.404 Machinery and equipment...

30 CFR 77.404 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the power is off and the machinery is blocked against motion, except where machinery motion is... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Machinery and equipment; operation and... OF UNDERGROUND COAL MINES Safeguards for Mechanical Equipment § 77.404 Machinery and equipment...

30 CFR 77.404 - Machinery and equipment; operation and maintenance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the power is off and the machinery is blocked against motion, except where machinery motion is... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Machinery and equipment; operation and... OF UNDERGROUND COAL MINES Safeguards for Mechanical Equipment § 77.404 Machinery and equipment...

Position-Dependent Cardiovascular Response and Time-Motion Analysis During Training Drills and Friendly Matches in Elite Male Basketball Players.

PubMed

Torres-Ronda, Lorena; Ric, Angel; Llabres-Torres, Ivan; de Las Heras, Bernat; Schelling I Del Alcazar, Xavi

2016-01-01

The purpose of this study was to measure differences in the cardiovascular workload (heart rate [HR]) and time-motion demands between positional groups, during numerous basketball training drills, and compare the results with in-game competition demands. A convenience sample of 14 top-level professional basketball players from the same club (Spanish First Division, ACB) participated in the study. A total of 146 basketball exercises per player (performed over an 8-week period in 32 team training sessions throughout the competitive season) and 7 friendly matches (FM) played during the preparatory phase were analyzed. The results reveal that HRavg and HRpeak were the highest in FM (158 ± 10; 198 ± 9 b · min(-1), respectively). Time-motion analysis showed 1v1 to be the most demanding drill (53 ± 8 and 46 ± 12 movements per minute for full and half court, respectively). During FM, players performed 33 ± 7 movements per minute. Positional differences exist for both HR and time-motion demands, ranging from moderate to very large for all basketball drills compared with FM. Constraints such as number of players, court size, work-to-rest ratios, and coach intervention are key factors influencing cardiovascular responses and time-motion demands during basketball training sessions. These results demonstrate that systematic monitoring of the physical demands and physiological responses during training and competition can inform and potentially improve coaching strategy, basketball-specific training drills, and ultimately, match performance.

A Comprehensive Motion Estimation Technique for the Improvement of EIS Methods Based on the SURF Algorithm and Kalman Filter.

PubMed

Cheng, Xuemin; Hao, Qun; Xie, Mengdi

2016-04-07

Video stabilization is an important technology for removing undesired motion in videos. This paper presents a comprehensive motion estimation method for electronic image stabilization techniques, integrating the speeded up robust features (SURF) algorithm, modified random sample consensus (RANSAC), and the Kalman filter, and also taking camera scaling and conventional camera translation and rotation into full consideration. Using SURF in sub-pixel space, feature points were located and then matched. The false matched points were removed by modified RANSAC. Global motion was estimated by using the feature points and modified cascading parameters, which reduced the accumulated errors in a series of frames and improved the peak signal to noise ratio (PSNR) by 8.2 dB. A specific Kalman filter model was established by considering the movement and scaling of scenes. Finally, video stabilization was achieved with filtered motion parameters using the modified adjacent frame compensation. The experimental results proved that the target images were stabilized even when the vibrating amplitudes of the video become increasingly large.

Triggered dynamics in a model of different fault creep regimes

PubMed Central

Kostić, Srđan; Franović, Igor; Perc, Matjaž; Vasović, Nebojša; Todorović, Kristina

2014-01-01

The study is focused on the effect of transient external force induced by a passing seismic wave on fault motion in different creep regimes. Displacement along the fault is represented by the movement of a spring-block model, whereby the uniform and oscillatory motion correspond to the fault dynamics in post-seismic and inter-seismic creep regime, respectively. The effect of the external force is introduced as a change of block acceleration in the form of a sine wave scaled by an exponential pulse. Model dynamics is examined for variable parameters of the induced acceleration changes in reference to periodic oscillations of the unperturbed system above the supercritical Hopf bifurcation curve. The analysis indicates the occurrence of weak irregular oscillations if external force acts in the post-seismic creep regime. When fault motion is exposed to external force in the inter-seismic creep regime, one finds the transition to quasiperiodic- or chaos-like motion, which we attribute to the precursory creep regime and seismic motion, respectively. If the triggered acceleration changes are of longer duration, a reverse transition from inter-seismic to post-seismic creep regime is detected on a larger time scale. PMID:24954397

Too Deep or Not Too Deep?: A Propensity-Matched Comparison of the Analgesic Effects of a Superficial Versus Deep Serratus Fascial Plane Block for Ambulatory Breast Cancer Surgery.

PubMed

Abdallah, Faraj W; Cil, Tulin; MacLean, David; Madjdpour, Caveh; Escallon, Jaime; Semple, John; Brull, Richard

2018-07-01

Serratus fascial plane block can reduce pain following breast surgery, but the question of whether to inject the local anesthetic superficial or deep to the serratus muscle has not been answered. This cohort study compares the analgesic benefits of superficial versus deep serratus plane blocks in ambulatory breast cancer surgery patients at Women's College Hospital between February 2014 and December 2016. We tested the joint hypothesis that deep serratus block is noninferior to superficial serratus block for postoperative in-hospital (pre-discharge) opioid consumption and pain severity. One hundred sixty-six patients were propensity matched among 2 groups (83/group): superficial and deep serratus blocks. The cohort was used to evaluate the effect of blocks on postoperative oral morphine equivalent consumption and area under the curve for rest pain scores. We considered deep serratus block to be noninferior to superficial serratus block if it were noninferior for both outcomes, within 15 mg morphine and 4 cm·h units margins. Other outcomes included intraoperative fentanyl requirements, time to first analgesic request, recovery room stay, and incidence of postoperative nausea and vomiting. Deep serratus block was associated with postoperative morphine consumption and pain scores area under the curve that were noninferior to those of the superficial serratus block. Intraoperative fentanyl requirements, time to first analgesic request, recovery room stay, and postoperative nausea and vomiting were not different between blocks. The postoperative in-hospital analgesia associated with deep serratus block is as effective (within an acceptable margin) as superficial serratus block following ambulatory breast cancer surgery. These new findings are important to inform both current clinical practices and future prospective studies.

A hint of Poincaré dodecahedral topology in the WMAP first year sky map

NASA Astrophysics Data System (ADS)

Roukema, B. F.; Lew, B.; Cechowska, M.; Marecki, A.; Bajtlik, S.

2004-09-01

It has recently been suggested by Luminet et al. (\\cite{LumNat03}) that the WMAP data are better matched by a geometry in which the topology is that of a Poincaré dodecahedral model and the curvature is ``slightly'' spherical, rather than by an (effectively) infinite flat model. A general back-to-back matched circles analysis by Cornish et al. (\\cite{CSSK03}) for angular radii in the range 25-90 °, using a correlation statistic for signal detection, failed to support this. In this paper, a matched circles analysis specifically designed to detect dodecahedral patterns of matched circles is performed over angular radii in the range 1-40\\ddeg on the one-year WMAP data. Signal detection is attempted via a correlation statistic and an rms difference statistic. Extreme value distributions of these statistics are calculated for one orientation of the 36\\ddeg ``screw motion'' (Clifford translation) when matching circles, for the opposite screw motion, and for a zero (unphysical) rotation. The most correlated circles appear for circle radii of \\alpha =11 ± 1 \\ddeg, for the left-handed screw motion, but not for the right-handed one, nor for the zero rotation. The favoured six dodecahedral face centres in galactic coordinates are (\\lII,\\bII) ≈ (252\\ddeg,+65\\ddeg), (51\\ddeg,+51\\ddeg), (144\\ddeg,+38\\ddeg), (207\\ddeg,+10\\ddeg), (271\\ddeg,+3\\ddeg), (332\\ddeg,+25\\ddeg) and their opposites. The six pairs of circles independently each favour a circle angular radius of 11 ± 1\\ddeg. The temperature fluctuations along the matched circles are plotted and are clearly highly correlated. Whether or not these six circle pairs centred on dodecahedral faces match via a 36\\ddeg rotation only due to unexpected statistical properties of the WMAP ILC map, or whether they match due to global geometry, it is clear that the WMAP ILC map has some unusual statistical properties which mimic a potentially interesting cosmological signal.

Multibuilding Block Janus Synthesized by Seed-Mediated Self-Assembly for Enhanced Photothermal Effects and Colored Brownian Motion in an Optical Trap.

PubMed

Sansanaphongpricha, Kanokwan; DeSantis, Michael C; Chen, Hongwei; Cheng, Wei; Sun, Kai; Wen, Bo; Sun, Duxin

2017-02-01

The asymmetrical features and unique properties of multibuilding block Janus nanostructures (JNSs) provide superior functions for biomedical applications. However, their production process is very challenging. This problem has hampered the progress of JNS research and the exploration of their applications. In this study, an asymmetrical multibuilding block gold/iron oxide JNS has been generated to enhance photothermal effects and display colored Brownian motion in an optical trap. JNS is formed by seed-mediated self-assembly of nanoparticle-loaded thermocleavable micelles, where the hydrophobic backbones of the polymer are disrupted at high temperatures, resulting in secondary self-assembly and structural rearrangement. The JNS significantly enhances photothermal effects compared to their homogeneous counterpart after near-infrared (NIR) light irradiation. The asymmetrical distribution of gold and iron oxide within JNS also generates uneven thermophoretic force to display active colored Brownian rotational motion in a single-beam gradient optical trap. These properties indicate that the asymmetrical JNS could be employed as a strong photothermal therapy mediator and a fuel-free nanoscale Janus motor under NIR light. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Player Load, Acceleration, and Deceleration During Forty-Five Competitive Matches of Elite Soccer.

PubMed

Dalen, Terje; Ingebrigtsen, Jørgen; Ettema, Gertjan; Hjelde, Geir Havard; Wisløff, Ulrik

2016-02-01

The use of time-motion analysis has advanced our understanding of position-specific work rate profiles and the physical requirements of soccer players. Still, many of the typical soccer activities can be neglected, as these systems only examine activities measured by distance and speed variables. This study used triaxial accelerometer and time-motion analysis to obtain new knowledge about elite soccer players' match load. Furthermore, we determined acceleration/deceleration profiles of elite soccer players and their contribution to the players' match load. The data set includes every domestic home game (n = 45) covering 3 full seasons (2009, 2010, and 2011) for the participating team (Rosenborg FC), and includes 8 central defenders (n = 68), 9 fullbacks (n = 83), 9 central midfielders (n = 70), 7 wide midfielders (n = 39), and 5 attackers (A, n = 50). A novel finding was that accelerations contributed to 7-10% of the total player load for all player positions, whereas decelerations contributed to 5-7%. Furthermore, the results indicate that other activities besides the high-intensity movements contribute significantly to the players' total match workload. Therefore, motion analysis alone may underestimate player load because many high-intensity actions are without a change in location at the pitch or they are classified as low-speed activity according to current standards. This new knowledge may help coaches to better understand the different ways players achieve match load and could be used in developing individualized programs that better meet the "positional physical demands" in elite soccer.

Neural mechanisms of motion sickness

NASA Technical Reports Server (NTRS)

Crampton, G. H.; Daunton, N. G.

1983-01-01

The possibility that there might be a neuro-homoral cerebrospinal fluid link in motion sickness was directly tested by blocking the flow of CSF from the third into the fourth ventricle in cats. Evidence obtained thus far is consistent with the hypothesis. Cats with demonstrably sound plugs did not vomit in response to an accelerative motion sickness stimulus, whereas cats with imperfect 'leaky' plugs vomited with little or no delay in latency. Althoough there are several putative candidates, the identification of a humoral motion sickness substance is a matter of conjecture.

An Investigation of Synthetic Aperture Radar Autofocus,

DTIC Science & Technology

1985-04-01

uniform straight line motion of the aircraft. Unknown aircraft motions alter the matched filter required for processing . Autofocussing involves determi...REFERENCES APPENDIX 1 RESOLUTION OF SAR APPENDIX 2 AIRCRAFT MOTION TOLERANCE APPENDIX 3 INITIAL RESOLUTION FOR FOLLOW-DOWN PROCESSING APPENDIX 4 DEPENDENCE OF...Range resolution is achieved using on-board pulse-compression techniques, while azimuth processing is currently done at RSRE on a Marconi hardware

Launch Lock Assemblies Including Axial Gap Amplification Devices and Spacecraft Isolation Systems Including the Same

NASA Technical Reports Server (NTRS)

Barber, Tim Daniel (Inventor); Hindle, Timothy (Inventor); Young, Ken (Inventor); Davis, Torey (Inventor)

2014-01-01

Embodiments of a launch lock assembly are provided, as are embodiments of a spacecraft isolation system including one or more launch lock assemblies. In one embodiment, the launch lock assembly includes first and second mount pieces, a releasable clamp device, and an axial gap amplification device. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement; and, when actuated, releases the first and second mount pieces from clamped engagement to allow relative axial motion there between. The axial gap amplification device normally residing in a blocking position wherein the gap amplification device obstructs relative axial motion between the first and second mount pieces. The axial gap amplification device moves into a non-blocking position when the first and second mount pieces are released from clamped engagement to increase the range of axial motion between the first and second mount pieces.

Parallel algorithm for determining motion vectors in ice floe images by matching edge features

NASA Technical Reports Server (NTRS)

Manohar, M.; Ramapriyan, H. K.; Strong, J. P.

1988-01-01

A parallel algorithm is described to determine motion vectors of ice floes using time sequences of images of the Arctic ocean obtained from the Synthetic Aperture Radar (SAR) instrument flown on-board the SEASAT spacecraft. Researchers describe a parallel algorithm which is implemented on the MPP for locating corresponding objects based on their translationally and rotationally invariant features. The algorithm first approximates the edges in the images by polygons or sets of connected straight-line segments. Each such edge structure is then reduced to a seed point. Associated with each seed point are the descriptions (lengths, orientations and sequence numbers) of the lines constituting the corresponding edge structure. A parallel matching algorithm is used to match packed arrays of such descriptions to identify corresponding seed points in the two images. The matching algorithm is designed such that fragmentation and merging of ice floes are taken into account by accepting partial matches. The technique has been demonstrated to work on synthetic test patterns and real image pairs from SEASAT in times ranging from .5 to 0.7 seconds for 128 x 128 images.

Cross Matching as Strategy to Find Radio Stars

NASA Astrophysics Data System (ADS)

Christian, Tiffany; Kimball, Amy

2018-01-01

Using cross-matching between the FIRST (20cm) and GPS1 (optical) catalogs, we identified possible radio star candidates. This is an extension of earlier work by Kimball et al. (2009), who sought to identify radiostar candidates by cross-matching the FIRST (radio)and SDSS (optical) catalogs, but did not include the consideration of stellar proper motions. We used proper motions from GPS1 to match with FIRST radio sources; the region of sky where they overlap contains ~900,000 FIRST sources and several million GPS1 sources. We used WISE near-infrared and PanSTARRS optical information to identify matches that have stellar colors. Our selection constraints identified 6 stars (spectroscopically confirmed) as radio star candidates. They are faint in the radio (<1 mJy) indicating we may be searching at the limits of the radio survey. Other candidates had no spectral confirmation or object type identification in SIMBAD, which would make them ideal for follow up radio observations. However, random analysis indicated that many other possible candidates were random associations, which may also be true for these 6 stars.

Does grammatical aspect affect motion event cognition? A cross-linguistic comparison of English and Swedish speakers.

PubMed

Athanasopoulos, Panos; Bylund, Emanuel

2013-03-01

In this article, we explore whether cross-linguistic differences in grammatical aspect encoding may give rise to differences in memory and cognition. We compared native speakers of two languages that encode aspect differently (English and Swedish) in four tasks that examined verbal descriptions of stimuli, online triads matching, and memory-based triads matching with and without verbal interference. Results showed between-group differences in verbal descriptions and in memory-based triads matching. However, no differences were found in online triads matching and in memory-based triads matching with verbal interference. These findings need to be interpreted in the context of the overall pattern of performance, which indicated that both groups based their similarity judgments on common perceptual characteristics of motion events. These results show for the first time a cross-linguistic difference in memory as a function of differences in grammatical aspect encoding, but they also contribute to the emerging view that language fine tunes rather than shapes perceptual processes that are likely to be universal and unchanging. Copyright © 2012 Cognitive Science Society, Inc.

Tunnelling from non-localised initial states

NASA Technical Reports Server (NTRS)

Bowcock, Peter; Gregory, Ruth

1991-01-01

An approach for calculating tunneling amplitudes from a nonlocalized initial state is presented. Generalizing the matching conditions and equations of motion to allow for complex momentum permits a description of tunneling in the presence of so-called classical motion. Possible applications of the method are presented.

Volumetric laser endomicroscopy in Barrett's esophagus: a feasibility study on histological correlation.

PubMed

Swager, A; Boerwinkel, D F; de Bruin, D M; Weusten, B L; Faber, D J; Meijer, S L; van Leeuwen, T G; Curvers, W L; Bergman, J J

2016-08-01

Volumetric laser endomicroscopy (VLE) is a novel balloon-based optical coherence tomography (OCT) imaging technique that may improve detection of early neoplasia in Barrett's esophagus (BE). Most OCT studies lack a direct correlation between histology and OCT images. The aim is to investigate the optimal approach for achieving one-to-one correlation of ex-vivo VLE images of endoscopic resection (ER) specimens with histology. BE patients with and without early neoplasia underwent ER after delineating areas with electrocoagulation markers (ECM). After ER, specimens underwent additional ex-vivo marking with several different markers (ink, pin, Gold Probe) followed by ex-vivo VLE scanning. ER specimens were carefully sectioned into tissue blocks guided by the markers. Histology and VLE slides were considered a match if ≥ 2 markers were visible on both modalities and mucosal patterns aside from these markers matched on both histology and VLE. From 16 ER specimens 120 tissue blocks were sectioned of which 23 contained multiple markers. Fourteen histology-VLE matches were identified. ECMs and ink markers proved to be the most effective combination for matching. The last 6/16 ER specimens yielded 9/14 matches, demonstrating a learning curve due to methodological improvements in marker placement and tissue block sectioning. One-to-one correlation of VLE and histology is complex but feasible. The groundwork laid in this study will provide high-quality histology-VLE correlations that will allow further research on VLE features of early neoplasia in BE. © 2015 International Society for Diseases of the Esophagus.

Visual motion combined with base of support width reveals variable field dependency in healthy young adults.

PubMed

Streepey, Jefferson W; Kenyon, Robert V; Keshner, Emily A

2007-01-01

We previously reported responses to induced postural instability in young healthy individuals viewing visual motion with a narrow (25 degrees in both directions) and wide (90 degrees and 55 degrees in the horizontal and vertical directions) field of view (FOV) as they stood on different sized blocks. Visual motion was achieved using an immersive virtual environment that moved realistically with head motion (natural motion) and translated sinusoidally at 0.1 Hz in the fore-aft direction (augmented motion). We observed that a subset of the subjects (steppers) could not maintain continuous stance on the smallest block when the virtual environment was in motion. We completed a posteriori analyses on the postural responses of the steppers and non-steppers that may inform us about the mechanisms underlying these differences in stability. We found that when viewing augmented motion with a wide FOV, there was a greater effect on the head and whole body center of mass and ankle angle root mean square (RMS) values of the steppers than of the non-steppers. FFT analyses revealed greater power at the frequency of the visual stimulus in the steppers compared to the non-steppers. Whole body COM time lags relative to the augmented visual scene revealed that the time-delay between the scene and the COM was significantly increased in the steppers. The increased responsiveness to visual information suggests a greater visual field-dependency of the steppers and suggests that the thresholds for shifting from a reliance on visual information to somatosensory information can differ even within a healthy population.

Time-Motion and Biological Responses in Simulated Mixed Martial Arts Sparring Matches.

PubMed

Coswig, Victor S; Ramos, Solange de P; Del Vecchio, Fabrício B

2016-08-01

Coswig, VS, Ramos, SdP, and Del Vecchio, FB. Time-motion and biological responses in simulated mixed martial arts sparring matches. J Strength Cond Res 30(8): 2156-2163, 2016-Simulated matches are a relevant component of training for mixed martial arts (MMA) athletes. This study aimed to characterize time-motion responses and investigate physiological stress and neuromuscular changes related to MMA sparring matches. Thirteen athletes with an average age of 25 ± 5 years, body mass of 81.3 ± 9.5 kg, height of 176.2 ± 5.5 cm, and time of practice in MMA of 39 ± 25 months participated in the study. The fighters executed three 5-minute rounds with 1-minute intervals. Blood and salivary samples were collected and physical tests and psychometric questionnaires administered at 3 time points: before (PRE), immediately after (POST), and 48 hours after the combat (48 h). Statistical analysis applied analysis of variance for repeated measurements. In biochemical analysis, significant changes (p ≤ 0.05) were identified between PRE and POST (glucose: 80.3 ± 12.7 to 156.5 ± 19.1 mg·ml; lactate: 4 ± 1.7 to 15.6 ± 4.8 mmol·dl), POST and 48 hours (glucose: 156.5 ± 19.1 to 87.6 ± 15.5 mg·ml; lactate: 15.6 ± 4.8 to 2.9 ± 3.5 mmol·dl; urea: 44.1 ± 8.9 to 36.3 ± 7.8 mg·ml), and PRE and 48 hours (creatine kinase [CK]: 255.8 ± 137.4 to 395.9 ± 188.7 U/L). In addition, time-motion analyses showed a total high:low intensity of 1:2 and an effort:pause ratio of 1:3. In conclusion, simulated MMA sparring matches feature moderate to high intensity and a low degree of musculoskeletal damage, which can be seen by absence of physical performance and decrease in CK. Results of the study indicate that sparring training could be introduced into competitive microcycles to improve technical and tactical aspects of MMA matches, due to the high motor specificity and low muscle damage.

North-South contraction of the mojave block and strike-slip tectonics in southern california.

PubMed

Bartley, J M; Glazner, A F; Schermer, E R

1990-06-15

The Mojave block of southern California has undergone significant late Cenozoic north-south contraction. This previously unappreciated deformation may account for part of the discrepancy between neotectonic and plate-tectonic estimates of Pacific-North American plate motion, and for part of the Big Bend in the San Andreas fault. In the eastern Mojave block, contraction is superimposed on early Miocene crustal extension. In the western Mojave block, contractional folds and reverse faults have been mistaken for extensional structures. The three-dimensional complexity of the contractional structures may mean that rigid-block tectonic models of the region based primarily on paleomagnetic data are unreliable.

Video error concealment using block matching and frequency selective extrapolation algorithms

NASA Astrophysics Data System (ADS)

P. K., Rajani; Khaparde, Arti

2017-06-01

Error Concealment (EC) is a technique at the decoder side to hide the transmission errors. It is done by analyzing the spatial or temporal information from available video frames. It is very important to recover distorted video because they are used for various applications such as video-telephone, video-conference, TV, DVD, internet video streaming, video games etc .Retransmission-based and resilient-based methods, are also used for error removal. But these methods add delay and redundant data. So error concealment is the best option for error hiding. In this paper, the error concealment methods such as Block Matching error concealment algorithm is compared with Frequency Selective Extrapolation algorithm. Both the works are based on concealment of manually error video frames as input. The parameter used for objective quality measurement was PSNR (Peak Signal to Noise Ratio) and SSIM(Structural Similarity Index). The original video frames along with error video frames are compared with both the Error concealment algorithms. According to simulation results, Frequency Selective Extrapolation is showing better quality measures such as 48% improved PSNR and 94% increased SSIM than Block Matching Algorithm.

An unrecognized major collision of the Okhotomorsk Block with East Asia during the Late Cretaceous, constraints on the plate reorganization of the Northwest Pacific

NASA Astrophysics Data System (ADS)

Yang, Yong-Tai

2013-11-01

Interactions at plate boundaries induce stresses that constitute critical controls on the structural evolution of intraplate regions. However, the traditional tectonic model for the East Asian margin during the Mesozoic, invoking successive episodes of paleo-Pacific oceanic subduction, does not provide an adequate context for important Late Cretaceous dynamics across East Asia, including: continental-scale orogenic processes, significant sinistral strike-slip faulting, and several others. The integration of numerous documented field relations requires a new tectonic model, as proposed here. The Okhotomorsk continental block, currently residing below the Okhotsk Sea in Northeast Asia, was located in the interior of the Izanagi Plate before the Late Cretaceous. It moved northwestward with the Izanagi Plate and collided with the South China Block at about 100 Ma. The indentation of the Okhotomorsk Block within East Asia resulted in the formation of a sinistral strike-slip fault system in South China, formation of a dextral strike-slip fault system in North China, and regional northwest-southeast shortening and orogenic uplift in East Asia. Northeast-striking mountain belts over 500 km wide extended from Southeast China to Southwest Japan and South Korea. The peak metamorphism at about 89 Ma of the Sanbagawa high-pressure metamorphic belt in Southwest Japan was probably related to the continental subduction of the Okhotomorsk Block beneath the East Asian margin. Subsequently, the north-northwestward change of motion direction of the Izanagi Plate led to the northward movement of the Okhotomorsk Block along the East Asian margin, forming a significant sinistral continental transform boundary similar to the San Andreas fault system in California. Sanbagawa metamorphic rocks in Southwest Japan were rapidly exhumed through the several-kilometer wide ductile shear zone at the lower crust and upper mantle level. Accretionary complexes successively accumulated along the East Asian margin during the Jurassic-Early Cretaceous were subdivided into narrow and subparallel belts by the upper crustal strike-slip fault system. The departure of the Okhotomorsk Block from the northeast-striking Asian margin resulted in the occurrence of an extensional setting and formation of a wide magmatic belt to the west of the margin. In the Campanian, the block collided with the Siberian margin, in Northeast Asia. At about 77 Ma, a new oceanic subduction occurred to the south of the Okhotomorsk Block, ending its long-distance northward motion. Based on the new tectonic model, the abundant Late Archean to Early Proterozoic detrital zircons in the Cretaceous sandstones in Kamchatka, Southwest Japan, and Taiwan are interpreted to have been sourced from the Okhotomorsk Block basement which possibly formed during the Late Archean and Early Proterozoic. The new model suggests a rapidly northward-moving Okhotomorsk Block at an average speed of 22.5 cm/yr during 89-77 Ma. It is hypothesized that the Okhotomorsk-East Asia collision during 100-89 Ma slowed down the northwestward motion of the Izanagi Plate, while slab pull forces produced from the subducting Izanagi Plate beneath the Siberian margin redirected the plate from northwestward to north-northwestward motion at about 90-89 Ma.

On the Geometry of Visual Correspondence

DTIC Science & Technology

1994-07-01

from point and line matches. In Proc. International Conference on Computer Vision, pages 25-34, 1987. [11] 0. Faugeras and S. Maybank . Motion from...image. Proceed- ings of the Royal Society, London B, 208:385-397, 1980. (23] S. Maybank . Theory of Reconstruction from Image Motion. Springer, Berlin

Simulation of tectonic evolution of the Kanto Basin of Japan since 1 Ma due to subduction of the Pacific and Philippine Sea plates and the collision of the Izu-Bonin arc

NASA Astrophysics Data System (ADS)

Hashima, Akinori; Sato, Toshinori; Sato, Hiroshi; Asao, Kazumi; Furuya, Hiroshi; Yamamoto, Shuji; Kameo, Koji; Miyauchi, Takahiro; Ito, Tanio; Tsumura, Noriko; Kaneda, Heitaro

2016-06-01

The Kanto Basin, the largest lowland in Japan, developed by flexure as a result of (1) the subduction of the Philippine Sea (PHS) and the Pacific (PAC) plates and (2) the repeated collision of the Izu-Bonin arc fragments with the Japanese island arc. Geomorphological, geological, and thermochronological data on vertical movements over the last 1 My suggest that subsidence initially affected the entire basin after which the area of subsidence gradually narrowed until, finally, the basin began to experience uplift. In this study, we modeled the tectonic evolution of the Kanto Basin following the method of Matsu'ura and Sato (1989) for a kinematic subduction model with dislocations, in order to quantitatively assess the effects of PHS and PAC subduction. We include the steady slip-rate deficit (permanent locking rate at the plate interface) in our model to account for collision process. We explore how the latest collision of the Izu Peninsula block has been affected by a westerly shift in the PHS plate motion vector with respect to the Eurasian plate, thought to have occurred between 1.0-0.5 Ma, using long-term vertical deformation data to constrain extent of the locked zone on the plate interface. We evaluated the change in vertical deformation rate for two scenarios: (1) a synchronous shift in the orientation of the locked zone as PHS plate motion shifts and (2) a delayed shift in the orientation of the locked zone following the shift in plate motion. Observed changes in the uplift/subsidence pattern are better explained by scenario (2), suggesting that recent (< 1 My) deformation in the Kanto Basin shows a lag in crustal response to the plate motion shift. We also calculated stress accumulation rates and found a good match with observed earthquake mechanisms, which shows that intraplate earthquakes serve to release stress accumulated through long-term plate interactions.

The kinematics of crustal deformation in Java from GPS observations: Implications for fault slip partitioning

NASA Astrophysics Data System (ADS)

Koulali, A.; McClusky, S.; Susilo, S.; Leonard, Y.; Cummins, P.; Tregoning, P.; Meilano, I.; Efendi, J.; Wijanarto, A. B.

2017-01-01

Our understanding of seismic risk in Java has been focused primarily on the subduction zone, where the seismic records during the last century have shown the occurrence of a number of tsunami earthquakes. However, the potential of the existence of active crustal structures within the island of Java itself is less well known. Historical archives show the occurrence of several devastating earthquake ruptures north of the volcanic arc in west Java during the 18th and the 19th centuries, suggesting the existence of active faults that need to be identified in order to guide seismic hazard assessment. Here we use geodetic constraints from the Global Positioning System (GPS) to quantify the present day crustal deformation in Java. The GPS velocities reveal a homogeneous counterclockwise rotation of the Java Block independent of Sunda Block, consistent with a NE-SW convergence between the Australian Plate and southeast Asia. Continuous GPS observations show a time-dependent change in the linear rate of surface motion in west Java, which we interpret as an ongoing long-term post-seismic deformation following the 2006 Mw 7.7 Java earthquake. We use an elastic block model in combination with a viscoelastic model to correct for this post-seismic transient and derive the long-term inter-seismic velocity, which we interpret as a combination of tectonic block motions and crustal faults strain related deformation. There is a north-south gradient in the resulting velocity field with a decrease in the magnitude towards the North across the Kendeng Thrust in the east and the Baribis Thrust in the west. We suggest that the Baribis Thrust is active and accommodating a slow relative motion between Java and the Sunda Block at about 5 ± 0.2 mm /yr. We propose a kinematic model of convergence of the Australian Plate and the Sunda Block, involving a slip partitioning between the Java Trench and a left-lateral structure extending E-W along Java with most of the convergence being accommodated by the Java megathrust, and a much smaller parallel motion accommodated along the Baribis (∼ 5 ± 0.2 mm /yr) and Kendeng (∼ 2.3 ± 0.7 mm /yr) Thrusts. Our study highlights a correlation between the geodetically inferred active faults and historical seismic catalogs, emphasizing the importance of considering crustal fault activity within Java in future seismic assessments.

Conveying Movement in Music and Prosody

PubMed Central

Hedger, Stephen C.; Nusbaum, Howard C.; Hoeckner, Berthold

2013-01-01

We investigated whether acoustic variation of musical properties can analogically convey descriptive information about an object. Specifically, we tested whether information from the temporal structure in music interacts with perception of a visual image to form an analog perceptual representation as a natural part of music perception. In Experiment 1, listeners heard music with an accelerating or decelerating temporal pattern, and then saw a picture of a still or moving object and decided whether it was animate or inanimate – a task unrelated to the patterning of the music. Object classification was faster when musical motion matched visually depicted motion. In Experiment 2, participants heard spoken sentences that were accompanied by accelerating or decelerating music, and then were presented with a picture of a still or moving object. When motion information in the music matched motion information in the picture, participants were similarly faster to respond. Fast and slow temporal patterns without acceleration and deceleration, however, did not make participants faster when they saw a picture depicting congruent motion information (Experiment 3), suggesting that understanding temporal structure information in music may depend on specific metaphors about motion in music. Taken together, these results suggest that visuo-spatial referential information can be analogically conveyed and represented by music and can be integrated with speech or influence the understanding of speech. PMID:24146920

Improving Sector Hash Carving with Rule-Based and Entropy-Based Non-Probative Block Filters

DTIC Science & Technology

2015-03-01

0x20 exceeds the histogram rule’s threshold of 256 instances of a single 4-byte value. The 0x20 bytes are part of an Extensible Metadata Platform (XMP...block consists of data separated by NULL bytes of padding. The histogram rule is triggered for the block because the block contains more than 256 4...sdash can reduce the rate of false positive matches. After characteristic features have been selected, the features are hashed using SHA -1, which creates

Experimental scheme and restoration algorithm of block compression sensing

NASA Astrophysics Data System (ADS)

Zhang, Linxia; Zhou, Qun; Ke, Jun

2018-01-01

Compressed Sensing (CS) can use the sparseness of a target to obtain its image with much less data than that defined by the Nyquist sampling theorem. In this paper, we study the hardware implementation of a block compression sensing system and its reconstruction algorithms. Different block sizes are used. Two algorithms, the orthogonal matching algorithm (OMP) and the full variation minimum algorithm (TV) are used to obtain good reconstructions. The influence of block size on reconstruction is also discussed.

Minutia Tensor Matrix: A New Strategy for Fingerprint Matching

PubMed Central

Fu, Xiang; Feng, Jufu

2015-01-01

Establishing correspondences between two minutia sets is a fundamental issue in fingerprint recognition. This paper proposes a new tensor matching strategy. First, the concept of minutia tensor matrix (simplified as MTM) is proposed. It describes the first-order features and second-order features of a matching pair. In the MTM, the diagonal elements indicate similarities of minutia pairs and non-diagonal elements indicate pairwise compatibilities between minutia pairs. Correct minutia pairs are likely to establish both large similarities and large compatibilities, so they form a dense sub-block. Minutia matching is then formulated as recovering the dense sub-block in the MTM. This is a new tensor matching strategy for fingerprint recognition. Second, as fingerprint images show both local rigidity and global nonlinearity, we design two different kinds of MTMs: local MTM and global MTM. Meanwhile, a two-level matching algorithm is proposed. For local matching level, the local MTM is constructed and a novel local similarity calculation strategy is proposed. It makes full use of local rigidity in fingerprints. For global matching level, the global MTM is constructed to calculate similarities of entire minutia sets. It makes full use of global compatibility in fingerprints. Proposed method has stronger description ability and better robustness to noise and nonlinearity. Experiments conducted on Fingerprint Verification Competition databases (FVC2002 and FVC2004) demonstrate the effectiveness and the efficiency. PMID:25822489

Modular support blocks for fluid lines

NASA Technical Reports Server (NTRS)

Dimino, J. M.; Deskin, R. D.

1974-01-01

Modular line block comprises matched modular elements machined to accept fluid lines of different diameters. Modules can support different fluid-line configurations. Top and bottom surfaces are machined to accept dovetail strip used for holding modules together. End modules have holes drilled through to accept fastening screws.

Geological interpretation of combined Seabeam, Gloria and seismic data from Anegada Passage (Virgin Islands, north Caribbean)

USGS Publications Warehouse

Jany, I.; Scanlon, Kathryn M.; Mauffret, A.

1990-01-01

The Anegada Passage (sensu lato) includes several basins and ridges from Southeast of Puerto Rico to the corner of the Virgin Islands Platform. Seabeam (Seacarib I) and Gloria long-range sidescan sonar surveys were carried out in this area. These new data allow us to propose an interpretation of the Anegada Passage. Most of the features described are related to wrench faulting: (a) St Croix and Virgin Islands Basins are pull-apart basins created in a right-lateral strike-slip environment based on their rhomboidal shape and seismic data (e.g. the flower structure). These two pull-aparts are divided into two sub-basins by a curvilinear normal fault in the Virgin Islands Basin and a right-lateral strike-slip fault in the St Croix Basin. (b) Tortola Ridge and a 'dog's leg' shaped structure are inferred to be restraining bends between two right-lateral strike-slip faults. (c) We identified two ENE-WSW volcanic lineaments in the eastern area and one volcano lying between Virgin Islands and St Croix Basins. (d) As shown by the seismic activity main wrench motion occurs along the north slope of Virgin Islands Basin and through Anegada Passage. A branching of this main fault transmits the transtensional motion to St Croix Basin. A two-stage story is proposed for the creation of the basins. A first extensional event during Eocene(?)-Oligocene-lower Miocene time created Virgin Islands, St Croix Basins and the tilted blocks of St Croix Ridge. A second transtensional event from Pliocene to Recent gave the present day pattern to this area. However, the displacement along the strike-slip faults is no more than 15 km long. The proposed geodynamic model is based on the separation of the northeastern Caribbean boundary into two blocks. In the West, the indenter of Beata Ridge gives a northeastern motion to Hispaniola Block. In the East, as a result of Hispaniola Block's motion, the Puerto Rico-Virgin Islands Block could escape in an east-northeast direction. 

Horizontal ridge reconstruction of the anterior maxilla using customized allogeneic bone blocks with a minimally invasive technique - a case series.

PubMed

Venet, Laurent; Perriat, Michel; Mangano, Francesco Guido; Fortin, Thomas

2017-12-08

Different surgical procedures have been proposed to achieve horizontal ridge reconstruction of the anterior maxilla; all these procedures, however, require bone replacement materials to be adapted to the bone defect at the time of implantation, resulting in complex and time-consuming procedures. The purpose of this study was to describe how to use a 3D printed hardcopy model of the maxilla to prepare customized milled bone blocks, to be adapted on the bone defect areas using a minimally invasive subperiosteal tunneling technique. Cone beam computed tomography (CBCT) images of the atrophic maxilla of six patients were acquired and modified into 3D reconstruction models. Data were transferred to a 3D printer and solid models were fabricated using autoclavable nylon polyamide. Before the surgery, freeze-dried cortico-cancellous blocks were manually milled and adapted on the 3D printed hardcopy models of the maxillary bone, in order to obtain customized allogeneic bone blocks. In total, eleven onlay customized allogeneic bone grafts were prepared and implanted in 6 patients, using a minimally invasive subperiosteal tunneling technique. The scaffolds closely matched the shape of the defects: this reduced the operation time and contributed to good healing. The patients did not demonstrate adverse events such as inflammation, dehiscence or flap re-opening during the recovery period; however, one patient experienced scaffold resorption, which was likely caused by uncontrolled motion of the removable provisional prosthesis. Following a 6 month healing period, CBCT was used to assess graft integration, which was followed by insertion of implants into the augmented areas. Prosthetic restorations were placed 4 months later. These observations suggest that customized bone allografts can be successfully used for horizontal ridge reconstruction of the anterior maxilla: patients demonstrated reduced morbidity and decreased total surgery time. Further studies on a larger sample of patients, with histologic evaluation and longer follow-up are needed to confirm the present observations.

SU-E-J-115: Correlation of Displacement Vector Fields Calculated by Deformable Image Registration Algorithms with Motion Parameters of CT Images with Well-Defined Targets and Controlled-Motion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaskowiak, J; Ahmad, S; Ali, I

Purpose: To investigate correlation of displacement vector fields (DVF) calculated by deformable image registration algorithms with motion parameters in helical axial and cone-beam CT images with motion artifacts. Methods: A mobile thorax phantom with well-known targets with different sizes that were made from water-equivalent material and inserted in foam to simulate lung lesions. The thorax phantom was imaged with helical, axial and cone-beam CT. The phantom was moved with a cyclic motion with different motion amplitudes and frequencies along the superior-inferior direction. Different deformable image registration algorithms including demons, fast demons, Horn-Shunck and iterative-optical-flow from the DIRART software were usedmore » to deform CT images for the phantom with different motion patterns. The CT images of the mobile phantom were deformed to CT images of the stationary phantom. Results: The values of displacement vectors calculated by deformable image registration algorithm correlated strongly with motion amplitude where large displacement vectors were calculated for CT images with large motion amplitudes. For example, the maximal displacement vectors were nearly equal to the motion amplitudes (5mm, 10mm or 20mm) at interfaces between the mobile targets lung tissue, while the minimal displacement vectors were nearly equal to negative the motion amplitudes. The maximal and minimal displacement vectors matched with edges of the blurred targets along the Z-axis (motion-direction), while DVF’s were small in the other directions. This indicates that the blurred edges by phantom motion were shifted largely to match with the actual target edge. These shifts were nearly equal to the motion amplitude. Conclusions: The DVF from deformable-image registration algorithms correlated well with motion amplitude of well-defined mobile targets. This can be used to extract motion parameters such as amplitude. However, as motion amplitudes increased, image artifacts increased significantly and that limited image quality and poor correlation between the motion amplitude and DVF was obtained.« less

Energy & Motion. Science Syllabus for Middle and Junior High Schools. Block G.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Bureau of Curriculum Development.

Listed in this science syllabus are concepts and understandings in eight major areas: (1) forces, motion, and work; (2) introduction to energy; (3) mechanical energy and machines; (4) sound energy; (5) electromagnetic energy and light energy; (6) heat energy; (7) electric and magnetic energy; and (8) nuclear energy. The booklet also includes…

Cell block samples from malignant pleural effusion might be valid alternative samples for anaplastic lymphoma kinase detection in patients with advanced non-small-cell lung cancer.

PubMed

Zhou, Jianya; Yao, Hongtian; Zhao, Jing; Zhang, Shumeng; You, Qihan; Sun, Ke; Zou, Yinying; Zhou, Caicun; Zhou, Jianying

2015-06-01

To evaluate the clinical value of cell block samples from malignant pleural effusion (MPE) as alternative samples to tumour tissue for anaplastic lymphoma kinase (ALK) detection in patients with advanced non-small-cell lung cancer (NSCLC). Fifty-two matched samples were eligible for analysis. ALK status was detected by Ventana immunohistochemistry (IHC) (with the D5F3 clone), reverse transcription polymerase chain reaction (RT-PCR) and fluorescence in-situ hybridization (FISH) in MPE cell block samples, and by FISH in tumour tissue block samples. In total, ALK FISH results were obtained for 52 tumour tissue samples and 41 MPE cell block samples. Eight cases (15.4%) were ALK-positive in tumour tissue samples by FISH, and among matched MPE cell block samples, five were ALK-positive by FISH, seven were ALK-positive by RT-PCR, and eight were ALK-positive by Ventana IHC. The ALK status concordance rates between tumour tissue and MPE cell block samples were 78.9% by FISH, 98.1% by RT-PCR, and 100% by Ventana IHC. In MPE cell block samples, the sensitivity and specificity of Ventana IHC (100% and 100%) and RT-PCR (87.5% and 100%) were higher than those of FISH (62.5% and 100%). Malignant pleural effusion cell block samples had a diagnostic performance for ALK detection in advanced NSCLC that was comparable to that of tumour tissue samples. MPE cell block samples might be valid alternative samples for ALK detection when tissue is not available. Ventana IHC could be the most suitable method for ALK detection in MPE cell block samples. © 2014 John Wiley & Sons Ltd.

Motion Perception and Driving: Predicting Performance Through Testing and Shortening Braking Reaction Times Through Training

DTIC Science & Technology

2013-12-01

brake reaction time on the EB test from pre-post while there was no significant change for the control group : t(38)=2.24, p=0.03. Tests of 3D motion...0.61). In experiment 2, the motion perception training group had a significant decrease in brake reaction time on the EB test from pre- to...the following. The experiment was divided into 8 phases: a pretest , six training blocks (once per week), and a posttest . Participants were allocated

A Methodology for the Evaluation of Alternative Offshore Container Discharge Systems.

DTIC Science & Technology

1982-04-01

effects of sea induced motions . These in- clude the use of larger capacity cranes to withstand the extra loads , structural modifications or add-on...relative motion between ships at sea. (39,40) Solutions include: a) Accelerometers mounted in the load block, crane boom tip, and on the deck of the...between the vertical motion of the crane boom and the load has the char- I acteristics of a high pass filter. That is, low frequency excursions of

Effects of Simulated Ship Motion on the Performance of Underway Officer of the Deck.

DTIC Science & Technology

1986-03-01

BURI ’ AU MIROCOPY RESOLUI p. ( NAVAL POSTGRADUATE SCHOOL N Monterey, California 00 I1ITIC iELECTiII THESIS EFFECTS OF SIMULATED SHIP MOTION ON THE...CODESj 16 SUBJECT TERMS (Continue on reverse if necessary and identify by block number) GROUP SUBGROUP,, ~~’A-’TSTS PAQ , Surface Warfare, Ship Motion...Analysis Questionnaire ( PAQ ) was used to analyze the duties of the 000, and the important areas so identified were tested using the Automated Portable Test

Behavior Matching in Multimodal Communication Is Synchronized

ERIC Educational Resources Information Center

Louwerse, Max M.; Dale, Rick; Bard, Ellen G.; Jeuniaux, Patrick

2012-01-01

A variety of theoretical frameworks predict the resemblance of behaviors between two people engaged in communication, in the form of coordination, mimicry, or alignment. However, little is known about the time course of the behavior matching, even though there is evidence that dyads synchronize oscillatory motions (e.g., postural sway). This study…

Preferences for Verb Interpretation in Children with Specific Language Impairment.

ERIC Educational Resources Information Center

Kelly, Donna J.; Rice, Mabel L.

1994-01-01

This study examined initial preferences for verb interpretation by 15 5-year-old children with specific language impairment, 15 language-matched children, and 15 age-matched children. Children indicated preferred interpretations of novel verbs from videotapes of motion and change-of-state activity scenes. Findings suggested that children's verb…

Visual Odometry Based on Structural Matching of Local Invariant Features Using Stereo Camera Sensor

PubMed Central

Núñez, Pedro; Vázquez-Martín, Ricardo; Bandera, Antonio

2011-01-01

This paper describes a novel sensor system to estimate the motion of a stereo camera. Local invariant image features are matched between pairs of frames and linked into image trajectories at video rate, providing the so-called visual odometry, i.e., motion estimates from visual input alone. Our proposal conducts two matching sessions: the first one between sets of features associated to the images of the stereo pairs and the second one between sets of features associated to consecutive frames. With respect to previously proposed approaches, the main novelty of this proposal is that both matching algorithms are conducted by means of a fast matching algorithm which combines absolute and relative feature constraints. Finding the largest-valued set of mutually consistent matches is equivalent to finding the maximum-weighted clique on a graph. The stereo matching allows to represent the scene view as a graph which emerge from the features of the accepted clique. On the other hand, the frame-to-frame matching defines a graph whose vertices are features in 3D space. The efficiency of the approach is increased by minimizing the geometric and algebraic errors to estimate the final displacement of the stereo camera between consecutive acquired frames. The proposed approach has been tested for mobile robotics navigation purposes in real environments and using different features. Experimental results demonstrate the performance of the proposal, which could be applied in both industrial and service robot fields. PMID:22164016

Survey of Motion Tracking Methods Based on Inertial Sensors: A Focus on Upper Limb Human Motion

PubMed Central

Filippeschi, Alessandro; Schmitz, Norbert; Miezal, Markus; Bleser, Gabriele; Ruffaldi, Emanuele; Stricker, Didier

2017-01-01

Motion tracking based on commercial inertial measurements units (IMUs) has been widely studied in the latter years as it is a cost-effective enabling technology for those applications in which motion tracking based on optical technologies is unsuitable. This measurement method has a high impact in human performance assessment and human-robot interaction. IMU motion tracking systems are indeed self-contained and wearable, allowing for long-lasting tracking of the user motion in situated environments. After a survey on IMU-based human tracking, five techniques for motion reconstruction were selected and compared to reconstruct a human arm motion. IMU based estimation was matched against motion tracking based on the Vicon marker-based motion tracking system considered as ground truth. Results show that all but one of the selected models perform similarly (about 35 mm average position estimation error). PMID:28587178

The performance of matched-field track-before-detect methods using shallow-water Pacific data.

PubMed

Tantum, Stacy L; Nolte, Loren W; Krolik, Jeffrey L; Harmanci, Kerem

2002-07-01

Matched-field track-before-detect processing, which extends the concept of matched-field processing to include modeling of the source dynamics, has recently emerged as a promising approach for maintaining the track of a moving source. In this paper, optimal Bayesian and minimum variance beamforming track-before-detect algorithms which incorporate a priori knowledge of the source dynamics in addition to the underlying uncertainties in the ocean environment are presented. A Markov model is utilized for the source motion as a means of capturing the stochastic nature of the source dynamics without assuming uniform motion. In addition, the relationship between optimal Bayesian track-before-detect processing and minimum variance track-before-detect beamforming is examined, revealing how an optimal tracking philosophy may be used to guide the modification of existing beamforming techniques to incorporate track-before-detect capabilities. Further, the benefits of implementing an optimal approach over conventional methods are illustrated through application of these methods to shallow-water Pacific data collected as part of the SWellEX-1 experiment. The results show that incorporating Markovian dynamics for the source motion provides marked improvement in the ability to maintain target track without the use of a uniform velocity hypothesis.

Convolutional auto-encoder for image denoising of ultra-low-dose CT.

PubMed

Nishio, Mizuho; Nagashima, Chihiro; Hirabayashi, Saori; Ohnishi, Akinori; Sasaki, Kaori; Sagawa, Tomoyuki; Hamada, Masayuki; Yamashita, Tatsuo

2017-08-01

The purpose of this study was to validate a patch-based image denoising method for ultra-low-dose CT images. Neural network with convolutional auto-encoder and pairs of standard-dose CT and ultra-low-dose CT image patches were used for image denoising. The performance of the proposed method was measured by using a chest phantom. Standard-dose and ultra-low-dose CT images of the chest phantom were acquired. The tube currents for standard-dose and ultra-low-dose CT were 300 and 10 mA, respectively. Ultra-low-dose CT images were denoised with our proposed method using neural network, large-scale nonlocal mean, and block-matching and 3D filtering. Five radiologists and three technologists assessed the denoised ultra-low-dose CT images visually and recorded their subjective impressions of streak artifacts, noise other than streak artifacts, visualization of pulmonary vessels, and overall image quality. For the streak artifacts, noise other than streak artifacts, and visualization of pulmonary vessels, the results of our proposed method were statistically better than those of block-matching and 3D filtering (p-values < 0.05). On the other hand, the difference in the overall image quality between our proposed method and block-matching and 3D filtering was not statistically significant (p-value = 0.07272). The p-values obtained between our proposed method and large-scale nonlocal mean were all less than 0.05. Neural network with convolutional auto-encoder could be trained using pairs of standard-dose and ultra-low-dose CT image patches. According to the visual assessment by radiologists and technologists, the performance of our proposed method was superior to that of large-scale nonlocal mean and block-matching and 3D filtering.

Analgesic Choice in Management of Rib Fractures: Paravertebral Block or Epidural Analgesia?

PubMed

Malekpour, Mahdi; Hashmi, Ammar; Dove, James; Torres, Denise; Wild, Jeffrey

2017-06-01

Rib fractures are commonly encountered in the setting of trauma. The aim of this study was to assess the association between the clinical outcome of rib fracture and epidural analgesia (EA) versus paravertebral block (PVB) using the National Trauma Data Bank (NTDB). Using the 2011 and 2012 versions of the NTDB, we retrieved completed records for all patients above 18 years of age who were admitted with rib fractures. Primary outcome was in-hospital mortality. Secondary outcomes were length of stay (LOS), intensive care unit (ICU) admission, ICU LOS, mechanical ventilation, duration of mechanical ventilation, development of pneumonia, and development of any other complication. Clinical outcomes were first compared between propensity score-matched EA and PVB patients. Then, EA and PVB patients were combined into the procedure group and the outcomes were compared with propensity score-matched patients that received neither intervention (no-procedure group). A total of 194,766 patients were included in the study with 1073 patients having EA, 1110 patients having PVB, and 192,583 patients having neither procedure. After propensity score matching, comparison of primary and secondary outcomes between EA and PVB patients showed no difference. Comparison of propensity score-matched procedure and no-procedure patients showed prolonged LOS and more frequent ICU admissions in patients receiving a procedure (both P < .0001), yet having no procedure was associated with a significantly increased odds of mortality (odds ratio: 2.25; 95% confidence interval, 1.14-3.84; P = .002). Using the NTDB, EA and PVB were not found to be significantly different in management of rib fractures. There was an association between use of a block and improved outcome, but this could be explained by selection of healthier patients to receive a block. Prospective study of this association is recommended.

Dynamic Response-by-Response Models of Matching Behavior in Rhesus Monkeys

PubMed Central

Lau, Brian; Glimcher, Paul W

2005-01-01

We studied the choice behavior of 2 monkeys in a discrete-trial task with reinforcement contingencies similar to those Herrnstein (1961) used when he described the matching law. In each session, the monkeys experienced blocks of discrete trials at different relative-reinforcer frequencies or magnitudes with unsignalled transitions between the blocks. Steady-state data following adjustment to each transition were well characterized by the generalized matching law; response ratios undermatched reinforcer frequency ratios but matched reinforcer magnitude ratios. We modelled response-by-response behavior with linear models that used past reinforcers as well as past choices to predict the monkeys' choices on each trial. We found that more recently obtained reinforcers more strongly influenced choice behavior. Perhaps surprisingly, we also found that the monkeys' actions were influenced by the pattern of their own past choices. It was necessary to incorporate both past reinforcers and past choices in order to accurately capture steady-state behavior as well as the fluctuations during block transitions and the response-by-response patterns of behavior. Our results suggest that simple reinforcement learning models must account for the effects of past choices to accurately characterize behavior in this task, and that models with these properties provide a conceptual tool for studying how both past reinforcers and past choices are integrated by the neural systems that generate behavior. PMID:16596980

2 CFR 200.101 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-01-01

... authorized under the Child Care and Development Block Grant Act of 1990, as amended: (i) Child Care and Development Block Grant (42 U.S.C. 9858) (ii) Child Care Mandatory and Matching Funds of the Child Care and... programs: (i) Special Supplemental Nutrition Program for Women, Infants and Children (section 17 of the...

In vivo quantification of motion in liver parenchyma and its application in shistosomiasis tissue characterization

NASA Astrophysics Data System (ADS)

Badawi, Ahmed M.; Hashem, Ahmed M.; Youssef, Abou-Bakr M.; Abdel-Wahab, Mohamed F.

1995-03-01

Schistosomiasis is a major problem in Egypt, despite an active control program it is estimated to exist in about 1/3 of the population. Deposition of less functioning fibrous tissues in the liver is the major contributory factor to the hepatic pathology. Fibrous tissues consist of a complex array of connective matrix material and a variety of collagen isotopes. As a result of an increased stromal density (collagen content), the parenchyma became more ectogenic and less elastic (hard). In this study we investigated the effect of cardiac mechanical impulses from the heart and aorta on the kinetics of the liver parenchyma. Under conditions of controlled patient movements and suspended respiration, a 30 frame per second of 588 X 512 ultrasound images (cineloop, 32 pels per cm) are captured from an aTL ultrasound machine then digitized. The image acquisition is triggered by the R wave of the ECG of the patient. The motion that has a forced oscillation form in the liver parenchyma is quantified by tracking of small box (20 - 30 pels) in 16 directions for all the successive 30 frames. The tracking was done using block matching techniques (the max correlation between boxes in time, frequency domains, and the minimum SAD (sum absolute difference) between boxes). The motion is quantified for many regions at different positions within the liver parenchyma for 80 cases of variable degrees of schisto., cirrhotic livers, and for normal livers. The velocity of the tissue is calculated from the displacement (quantified motion), time between frames, and the scan time for the ultrasound scanner. We found that the motion in liver parenchyma is small in the order of very few millimeters, and the attenuation of the mechanical wave for one ECG cycle is higher in the schisto. and cirrhotic livers than in the normal ones. Finally quantification of motion in liver parenchyma due to cardiac impulses under controlled limb movement and respiration may be of value in the characterization of schisto. (elasticity based not scattering based). This value could be used together with the wide varieties of quantitative tissue characterization parameters for pathology differentiation and for differentiating subclasses of cirrhosis as well as the determination of the extent of bilharzial affection.

Differences in kinematic control of ankle joint motions in people with chronic ankle instability.

PubMed

Kipp, Kristof; Palmieri-Smith, Riann M

2013-06-01

People with chronic ankle instability display different ankle joint motions compared to healthy people. The purpose of this study was to investigate the strategies used to control ankle joint motions between a group of people with chronic ankle instability and a group of healthy, matched controls. Kinematic data were collected from 11 people with chronic ankle instability and 11 matched control subjects as they performed a single-leg land-and-cut maneuver. Three-dimensional ankle joint angles were calculated from 100 ms before, to 200 ms after landing. Kinematic control of the three rotational ankle joint degrees of freedom was investigated by simultaneously examining the three-dimensional co-variation of plantarflexion/dorsiflexion, toe-in/toe-out rotation, and inversion/eversion motions with principal component analysis. Group differences in the variance proportions of the first two principal components indicated that the angular co-variation between ankle joint motions was more linear in the control group, but more planar in the chronic ankle instability group. Frontal and transverse plane motions, in particular, contributed to the group differences in the linearity and planarity of angular co-variation. People with chronic ankle instability use a different kinematic control strategy to coordinate ankle joint motions during a single-leg landing task. Compared to the healthy group, the chronic ankle instability group's control strategy appeared to be more complex and involved joint-specific contributions that would tend to predispose this group to recurring episodes of instability. Copyright © 2013 Elsevier Ltd. All rights reserved.

Neurophysiological and Behavioural Correlates of Coherent Motion Perception in Dyslexia

ERIC Educational Resources Information Center

Taroyan, Naira A.; Nicolson, Roderick I.; Buckley, David

2011-01-01

Coherent motion perception was tested in nine adolescents with dyslexia and 10 control participants matched for age and IQ using low contrast stimuli with three levels of coherence (10%, 25% and 40%). Event-related potentials (ERPs) and behavioural performance data were obtained. No significant between-group differences were found in performance…

Young Children Can Extend Motion Verbs to Point-Light Displays.

ERIC Educational Resources Information Center

Golinkoff, Roberta Michnick; Chung, He Len; Hirsh-Pasek, Kathy; Liu, Jing; Bertenthal, Bennett I.; Brand, Rebecca; Maguire, Mandy J.; Hennon, Elizabeth

2002-01-01

Used point-light displays (lights corresponding to the joints of the human body) to examine 3-year-olds' understanding of verbs. Found that children could extend familiar motion verbs (walking, dancing) to videotaped point-light actions shown in an intermodal preferential looking paradigm. Children watched the action matching the requested verb…

Low cognitive load and reduced arousal impede practice effects on executive functioning, metacognitive confidence and decision making.

PubMed

Jackson, Simon A; Kleitman, Sabina; Aidman, Eugene

2014-01-01

The present study investigated the effects of low cognitive workload and the absence of arousal induced via external physical stimulation (motion) on practice-related improvements in executive (inhibitory) control, short-term memory, metacognitive monitoring and decision making. A total of 70 office workers performed low and moderately engaging passenger tasks in two successive 20-minute simulated drives and repeated a battery of decision making and inhibitory control tests three times—before, between and after these drives. For half the participants, visual simulation was synchronised with (moderately arousing) motion generated through LAnd Motion Platform, with vibration levels corresponding to a well-maintained unsealed road. The other half performed the same simulated drive without motion. Participants' performance significantly improved over the three test blocks, which is indicative of typical practice effects. The magnitude of these improvements was the highest when both motion and moderate cognitive load were present. The same effects declined either in the absence of motion (low arousal) or following a low cognitive workload task, thus suggesting two distinct pathways through which practice-related improvements in cognitive performance may be hampered. Practice, however, degraded certain aspects of metacognitive performance, as participants became less likely to detect incorrect decisions in the decision-making test with each subsequent test block. Implications include consideration of low cognitive load and arousal as factors responsible for performance decline and targets for the development of interventions/strategies in low load/arousal conditions such as autonomous vehicle operations and highway driving.

Validation of GATE Monte Carlo simulations of the GE Advance/Discovery LS PET scanners.

PubMed

Schmidtlein, C Ross; Kirov, Assen S; Nehmeh, Sadek A; Erdi, Yusuf E; Humm, John L; Amols, Howard I; Bidaut, Luc M; Ganin, Alex; Stearns, Charles W; McDaniel, David L; Hamacher, Klaus A

2006-01-01

The recently developed GATE (GEANT4 application for tomographic emission) Monte Carlo package, designed to simulate positron emission tomography (PET) and single photon emission computed tomography (SPECT) scanners, provides the ability to model and account for the effects of photon noncollinearity, off-axis detector penetration, detector size and response, positron range, photon scatter, and patient motion on the resolution and quality of PET images. The objective of this study is to validate a model within GATE of the General Electric (GE) Advance/Discovery Light Speed (LS) PET scanner. Our three-dimensional PET simulation model of the scanner consists of 12 096 detectors grouped into blocks, which are grouped into modules as per the vendor's specifications. The GATE results are compared to experimental data obtained in accordance with the National Electrical Manufactures Association/Society of Nuclear Medicine (NEMA/SNM), NEMA NU 2-1994, and NEMA NU 2-2001 protocols. The respective phantoms are also accurately modeled thus allowing us to simulate the sensitivity, scatter fraction, count rate performance, and spatial resolution. In-house software was developed to produce and analyze sinograms from the simulated data. With our model of the GE Advance/Discovery LS PET scanner, the ratio of the sensitivities with sources radially offset 0 and 10 cm from the scanner's main axis are reproduced to within 1% of measurements. Similarly, the simulated scatter fraction for the NEMA NU 2-2001 phantom agrees to within less than 3% of measured values (the measured scatter fractions are 44.8% and 40.9 +/- 1.4% and the simulated scatter fraction is 43.5 +/- 0.3%). The simulated count rate curves were made to match the experimental curves by using deadtimes as fit parameters. This resulted in deadtime values of 625 and 332 ns at the Block and Coincidence levels, respectively. The experimental peak true count rate of 139.0 kcps and the peak activity concentration of 21.5 kBq/cc were matched by the simulated results to within 0.5% and 0.1% respectively. The simulated count rate curves also resulted in a peak NECR of 35.2 kcps at 10.8 kBq/cc compared to 37.6 kcps at 10.0 kBq/cc from averaged experimental values. The spatial resolution of the simulated scanner matched the experimental results to within 0.2 mm.

Efficient Generation of Dancing Animation Synchronizing with Music Based on Meta Motion Graphs

NASA Astrophysics Data System (ADS)

Xu, Jianfeng; Takagi, Koichi; Sakazawa, Shigeyuki

This paper presents a system for automatic generation of dancing animation that is synchronized with a piece of music by re-using motion capture data. Basically, the dancing motion is synthesized according to the rhythm and intensity features of music. For this purpose, we propose a novel meta motion graph structure to embed the necessary features including both rhythm and intensity, which is constructed on the motion capture database beforehand. In this paper, we consider two scenarios for non-streaming music and streaming music, where global search and local search are required respectively. In the case of the former, once a piece of music is input, the efficient dynamic programming algorithm can be employed to globally search a best path in the meta motion graph, where an objective function is properly designed by measuring the quality of beat synchronization, intensity matching, and motion smoothness. In the case of the latter, the input music is stored in a buffer in a streaming mode, then an efficient search method is presented for a certain amount of music data (called a segment) in the buffer with the same objective function, resulting in a segment-based search approach. For streaming applications, we define an additional property in the above meta motion graph to deal with the unpredictable future music, which guarantees that there is some motion to match the unknown remaining music. A user study with totally 60 subjects demonstrates that our system outperforms the stat-of-the-art techniques in both scenarios. Furthermore, our system improves the synthesis speed greatly (maximal speedup is more than 500 times), which is essential for mobile applications. We have implemented our system on commercially available smart phones and confirmed that it works well on these mobile phones.

Solution of the exact equations for three-dimensional atmospheric entry using directly matched asymptotic expansions

NASA Technical Reports Server (NTRS)

Busemann, A.; Vinh, N. X.; Culp, R. D.

1976-01-01

The problem of determining the trajectories, partially or wholly contained in the atmosphere of a spherical, nonrotating planet, is considered. The exact equations of motion for three-dimensional, aerodynamically affected flight are derived. Modified Chapman variables are introduced and the equations are transformed into a set suitable for analytic integration using asymptotic expansions. The trajectory is solved in two regions: the outer region, where the force may be considered a gravitational field with aerodynamic perturbations, and the inner region, where the force is predominantly aerodynamic, with gravity as a perturbation. The two solutions are matched directly. A composite solution, valid everywhere, is constructed by additive composition. This approach of directly matched asymptotic expansions applied to the exact equations of motion couched in terms of modified Chapman variables yields an analytical solution which should prove to be a powerful tool for aerodynamic orbit calculations.

Visual Occlusion Decreases Motion Sickness in a Flight Simulator.

PubMed

Ishak, Shaziela; Bubka, Andrea; Bonato, Frederick

2018-05-01

Sensory conflict theories of motion sickness (MS) assert that symptoms may result when incoming sensory inputs (e.g., visual and vestibular) contradict each other. Logic suggests that attenuating input from one sense may reduce conflict and hence lessen MS symptoms. In the current study, it was hypothesized that attenuating visual input by blocking light entering the eye would reduce MS symptoms in a motion provocative environment. Participants sat inside an aircraft cockpit mounted onto a motion platform that simultaneously pitched, rolled, and heaved in two conditions. In the occluded condition, participants wore "blackout" goggles and closed their eyes to block light. In the control condition, participants opened their eyes and had full view of the cockpit's interior. Participants completed separate Simulator Sickness Questionnaires before and after each condition. The posttreatment total Simulator Sickness Questionnaires and subscores for nausea, oculomotor, and disorientation in the control condition were significantly higher than those in the occluded condition. These results suggest that under some conditions attenuating visual input may delay the onset of MS or weaken the severity of symptoms. Eliminating visual input may reduce visual/nonvisual sensory conflict by weakening the influence of the visual channel, which is consistent with the sensory conflict theory of MS.

Micro-valve using induced-charge electrokinetic motion of Janus particle.

PubMed

Daghighi, Yasaman; Li, Dongqing

2011-09-07

A new micro-valve using the electrokinetic motion of a Janus particle is introduced in this paper. A Janus particle with a conducting hemisphere and a non-conducting hemisphere is placed in a junction of several microchannels. Under an applied electric field, the induced-charge electrokinetic flow around the conducting side of the Janus particle forms vortices. The vortices push the particle moving forwards to block the entrance of a microchannel. By switching the direction of the applied electric field, the motion of the Janus particle can be changed to block different microchannels. This paper develops a theoretical model and conducts numerical simulations of the three-dimensional transient motion of the Janus particle. The results show that this Janus particle-based micro-valve is feasible for switching and controlling the flow rate in a microfluidic chip. This method is simple in comparison with other types of micro-valve methods. It is easy for fabrication, for operation control, and has a fast response time. To better understand the micro-valve functions, comparisons with a non-conducting particle and a fully conducting particle were made. Results proved that only a Janus particle can fulfill the requirements of such a micro-valve.

Origami building blocks: Generic and special four-vertices

NASA Astrophysics Data System (ADS)

Waitukaitis, Scott; van Hecke, Martin

2016-02-01

Four rigid panels connected by hinges that meet at a point form a four-vertex, the fundamental building block of origami metamaterials. Most materials designed so far are based on the same four-vertex geometry, and little is known regarding how different geometries affect folding behavior. Here we systematically categorize and analyze the geometries and resulting folding motions of Euclidean four-vertices. Comparing the relative sizes of sector angles, we identify three types of generic vertices and two accompanying subtypes. We determine which folds can fully close and the possible mountain-valley assignments. Next, we consider what occurs when sector angles or sums thereof are set equal, which results in 16 special vertex types. One of these, flat-foldable vertices, has been studied extensively, but we show that a wide variety of qualitatively different folding motions exist for the other 15 special and 3 generic types. Our work establishes a straightforward set of rules for understanding the folding motion of both generic and special four-vertices and serves as a roadmap for designing origami metamaterials.

Origami building blocks: Generic and special four-vertices.

PubMed

Waitukaitis, Scott; van Hecke, Martin

2016-02-01

Four rigid panels connected by hinges that meet at a point form a four-vertex, the fundamental building block of origami metamaterials. Most materials designed so far are based on the same four-vertex geometry, and little is known regarding how different geometries affect folding behavior. Here we systematically categorize and analyze the geometries and resulting folding motions of Euclidean four-vertices. Comparing the relative sizes of sector angles, we identify three types of generic vertices and two accompanying subtypes. We determine which folds can fully close and the possible mountain-valley assignments. Next, we consider what occurs when sector angles or sums thereof are set equal, which results in 16 special vertex types. One of these, flat-foldable vertices, has been studied extensively, but we show that a wide variety of qualitatively different folding motions exist for the other 15 special and 3 generic types. Our work establishes a straightforward set of rules for understanding the folding motion of both generic and special four-vertices and serves as a roadmap for designing origami metamaterials.

Training industrial robots with gesture recognition techniques

NASA Astrophysics Data System (ADS)

Piane, Jennifer; Raicu, Daniela; Furst, Jacob

2013-01-01

In this paper we propose to use gesture recognition approaches to track a human hand in 3D space and, without the use of special clothing or markers, be able to accurately generate code for training an industrial robot to perform the same motion. The proposed hand tracking component includes three methods: a color-thresholding model, naïve Bayes analysis and Support Vector Machine (SVM) to detect the human hand. Next, it performs stereo matching on the region where the hand was detected to find relative 3D coordinates. The list of coordinates returned is expectedly noisy due to the way the human hand can alter its apparent shape while moving, the inconsistencies in human motion and detection failures in the cluttered environment. Therefore, the system analyzes the list of coordinates to determine a path for the robot to move, by smoothing the data to reduce noise and looking for significant points used to determine the path the robot will ultimately take. The proposed system was applied to pairs of videos recording the motion of a human hand in a „real‟ environment to move the end-affector of a SCARA robot along the same path as the hand of the person in the video. The correctness of the robot motion was determined by observers indicating that motion of the robot appeared to match the motion of the video.

BEHAVIORAL COACHING TO IMPROVE OFFENSIVE LINE PASS-BLOCKING SKILLS OF HIGH SCHOOL FOOTBALL ATHLETES

PubMed Central

Stokes, John V; Luiselli, James K; Reed, Derek D; Fleming, Richard K

2010-01-01

We evaluated several behavioral coaching procedures for improving offensive line pass-blocking skills with 5 high school varsity football players. Pass blocking was measured during practice drills and games, and our intervention included descriptive feedback with and without video feedback and teaching with acoustical guidance (TAG). Intervention components and pass blocking were evaluated in a multiple baseline design, which showed that video feedback and TAG were the most effective procedures. For all players, improved pass blocking matched a standard derived by observing more experienced linemen and was evident in games. Additional intervention was required to maintain pass-blocking proficiency. Issues pertinent to behavioral coaching and sport psychology research are discussed. PMID:21358905

Schematic and realistic biological motion identification in children with high-functioning autism spectrum disorder

PubMed Central

Wright, Kristyn; Kelley, Elizabeth; Poulin-Dubois, Diane

2014-01-01

Research investigating biological motion perception in children with ASD has revealed conflicting findings concerning whether impairments in biological motion perception exist. The current study investigated how children with high-functioning ASD (HF-ASD) performed on two tasks of biological motion identification: a novel schematic motion identification task and a point-light biological motion identification task. Twenty-two HFASD children were matched with 21 TD children on gender, non-verbal mental, and chronological, age (M years = 6.72). On both tasks, HF-ASD children performed with similar accuracy as TD children. Across groups, children performed better on animate than on inanimate trials of both tasks. These findings suggest that HF-ASD children's identification of both realistic and schematic biological motion identification is unimpaired. PMID:25395988

A rate-constrained fast full-search algorithm based on block sum pyramid.

PubMed

Song, Byung Cheol; Chun, Kang-Wook; Ra, Jong Beom

2005-03-01

This paper presents a fast full-search algorithm (FSA) for rate-constrained motion estimation. The proposed algorithm, which is based on the block sum pyramid frame structure, successively eliminates unnecessary search positions according to rate-constrained criterion. This algorithm provides the identical estimation performance to a conventional FSA having rate constraint, while achieving considerable reduction in computation.

Standard Methodology for Assessment of Range of Motion While Wearing Body Armor

DTIC Science & Technology

2013-09-30

8 Figure 14: Meter stick (with close up...the tester to place against the measurement scale. A variety of rulers, meter sticks (Figure 14), and T square rulers (Figure 15) were used as well...All rulers and meter sticks had cm and mm marks on them. Figure 12: 20 cm block Figure 13: Measuring block Figure 14: Meter stick

Ergonomic evaluation of masons laying concrete masonry units and autoclaved aerated concrete.

PubMed

Hess, Jennifer A; Kincl, Laurel; Amasay, Tal; Wolfe, Peter

2010-05-01

Masons working with concrete masonry unit block have high rates of work-related musculoskeletal disorders to the low back and shoulders associated with repetitively lifting and buttering heavy block. A new material, autoclaved aerated concrete, may reduce the risk of shoulder and back injury but, ergonomic evaluation is needed. This study evaluated shoulder exposure parameters, low back stress, and worker perceptions in two groups of journey level masons, one using CMU and the other using AAC block. Results indicate that for the left arm AAC masons spent significantly more time than CMU masons in static (38.2% versus 31.1%, respectively), and less time in slow motions (48.2% versus 52.2%, respectively) and faster motions (13.6% versus 16.7%, respectively) (p<0.05). CMU masons had significantly greater shoulder and low back pain (p=0.009) and they held block significantly longer than AAC masons (p<0.001). Low back compressive forces were high for both materials. Masons handling AAC demonstrated less left upper extremity stress but both materials were estimated to be hazardous to the low back. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Local infiltration analgesia is comparable to femoral nerve block after anterior cruciate ligament reconstruction with hamstring tendon graft: a randomised controlled trial.

PubMed

Kristensen, Pia Kjær; Pfeiffer-Jensen, Mogens; Storm, Jens Ole; Thillemann, Theis Muncholm

2014-02-01

Arthroscopic anterior cruciate ligament (ACL) reconstruction is a painful procedure requiring intensive postoperative pain management. Femoral nerve block is widely used in ACL surgery. However, femoral nerve block does not cover the donor site of the hamstring tendons. Local infiltration analgesia is a simple technique that has proven effective in postoperative pain management after total knee arthroplasty. Further, local infiltration analgesia covers the donor site and is associated with few complications. It was hypothesised that local infiltration analgesia at the donor site and wounds would decrease pain and opioid consumption after ACL reconstruction with hamstring tendon graft. Sixty patients undergoing primary ACL surgery with hamstring tendon graft were randomised to receive either local infiltration analgesia or femoral nerve block. Pain was scored on the numeric rating scale, and use of opioid, range of motion and adverse effects were assessed at the postoperative recovery unit (0 h), 3, 24 and 48 h, postoperatively. There were no significant differences between the groups in pain intensity or total opioid consumption at any of the follow-up points. Further, there were no differences between groups concerning side effects and range of motion. Local infiltration analgesia and femoral nerve block are similar in the management of postoperative pain after ACL reconstruction with hamstring tendon graft. Until randomised studies have investigated femoral nerve block combined with infiltration at the donor site, we recommend local infiltration analgesia in ACL reconstruction with hamstring tendon graft.

Reconstructing mantle heterogeneity with data assimilation based on the back-and-forth nudging method: Implications for mantle-dynamic fitting of past plate motions

NASA Astrophysics Data System (ADS)

Glišović, Petar; Forte, Alessandro

2016-04-01

The paleo-distribution of density variations throughout the mantle is unknown. To address this question, we reconstruct 3-D mantle structure over the Cenozoic era using a data assimilation method that implements a new back-and-forth nudging algorithm. For this purpose, we employ convection models for a compressible and self-gravitating mantle that employ 3-D mantle structure derived from joint seismic-geodynamic tomography as a starting condition. These convection models are then integrated backwards in time and are required to match geologic estimates of past plate motions derived from marine magnetic data. Our implementation of the nudging algorithm limits the difference between a reconstruction (backward-in-time solution) and a prediction (forward-in-time solution) on over a sequence of 5-million-year time windows that span the Cenozoic. We find that forward integration of reconstructed mantle heterogeneity that is constrained to match past plate motions delivers relatively poor fits to the seismic-tomographic inference of present-day mantle heterogeneity in the upper mantle. We suggest that uncertainties in the past plate motions, related for example to plate reorganization episodes, could partly contribute to the poor match between predicted and observed present-day heterogeneity. We propose that convection models that allow tectonic plates to evolve freely in accord with the buoyancy forces and rheological structure in the mantle could provide additional constraints on geologic estimates of paleo-configurations of the major tectonic plates.

Interpreting physical performance in professional soccer match-play: should we be more pragmatic in our approach?

PubMed

Carling, Christopher

2013-08-01

Academic and practitioner interest in the physical performance of male professional soccer players in the competition setting determined via time-motion analyses has grown substantially over the last four decades leading to a substantial body of published research and aiding development of a more systematic evidence-based framework for physical conditioning. Findings have forcibly shaped contemporary opinions in the sport with researchers and practitioners frequently emphasising the important role that physical performance plays in match outcomes. Time-motion analyses have also influenced practice as player conditioning programmes can be tailored according to the different physical demands identified across individual playing positions. Yet despite a more systematic approach to physical conditioning, data indicate that even at the very highest standards of competition, the contemporary player is still susceptible to transient and end-game fatigue. Over the course of this article, the author suggests that a more pragmatic approach to interpreting the current body of time-motion analysis data and its application in the practical setting is nevertheless required. Examples of this are addressed using findings in the literature to examine (a) the association between competitive physical performance and 'success' in professional soccer, (b) current approaches to interpreting differences in time-motion analysis data across playing positions, and (c) whether data can realistically be used to demonstrate the occurrence of fatigue in match-play. Gaps in the current literature and directions for future research are also identified.

Deformed Palmprint Matching Based on Stable Regions.

PubMed

Wu, Xiangqian; Zhao, Qiushi

2015-12-01

Palmprint recognition (PR) is an effective technology for personal recognition. A main problem, which deteriorates the performance of PR, is the deformations of palmprint images. This problem becomes more severe on contactless occasions, in which images are acquired without any guiding mechanisms, and hence critically limits the applications of PR. To solve the deformation problems, in this paper, a model for non-linearly deformed palmprint matching is derived by approximating non-linear deformed palmprint images with piecewise-linear deformed stable regions. Based on this model, a novel approach for deformed palmprint matching, named key point-based block growing (KPBG), is proposed. In KPBG, an iterative M-estimator sample consensus algorithm based on scale invariant feature transform features is devised to compute piecewise-linear transformations to approximate the non-linear deformations of palmprints, and then, the stable regions complying with the linear transformations are decided using a block growing algorithm. Palmprint feature extraction and matching are performed over these stable regions to compute matching scores for decision. Experiments on several public palmprint databases show that the proposed models and the KPBG approach can effectively solve the deformation problem in palmprint verification and outperform the state-of-the-art methods.

Recognition of Facial Expressions of Emotion in Adults with Down Syndrome

ERIC Educational Resources Information Center

Virji-Babul, Naznin; Watt, Kimberley; Nathoo, Farouk; Johnson, Peter

2012-01-01

Research on facial expressions in individuals with Down syndrome (DS) has been conducted using photographs. Our goal was to examine the effect of motion on perception of emotional expressions. Adults with DS, adults with typical development matched for chronological age (CA), and children with typical development matched for developmental age (DA)…

Motion versus position in the perception of head-centred movement.

PubMed

Freeman, Tom C A; Sumnall, Jane H

2002-01-01

Abstract. Observers can recover motion with respect to the head during an eye movement by comparing signals encoding retinal motion and the velocity of pursuit. Evidently there is a mismatch between these signals because perceived head-centred motion is not always veridical. One example is the Filehne illusion, in which a stationary object appears to move in the opposite direction to pursuit. Like the motion aftereffect, the phenomenal experience of the Filehne illusion is one in which the stimulus moves but does not seem to go anywhere. This raises problems when measuring the illusion by motion nulling because the more traditional technique confounds perceived motion with changes in perceived position. We devised a new nulling technique using global-motion stimuli that degraded familiar position cues but preserved cues to motion. Stimuli consisted of random-dot patterns comprising signal and noise dots that moved at the same retinal 'base' speed. Noise moved in random directions. In an eye-stationary speed-matching experiment we found noise slowed perceived retinal speed as 'coherence strength' (ie percentage of signal) was reduced. The effect occurred over the two-octave range of base speeds studied and well above direction threshold. When the same stimuli were combined with pursuit, observers were able to null the Filehne illusion by adjusting coherence. A power law relating coherence to retinal base speed fit the data well with a negative exponent. Eye-movement recordings showed that pursuit was quite accurate. We then tested the hypothesis that the stimuli found at the null-points appeared to move at the same retinal speed. Two observers supported the hypothesis, a third partially, and a fourth showed a small linear trend. In addition, the retinal speed found by the traditional Filehne technique was similar to the matches obtained with the global-motion stimuli. The results provide support for the idea that speed is the critical cue in head-centred motion perception.

Application of constrained k-means clustering in ground motion simulation validation

NASA Astrophysics Data System (ADS)

Khoshnevis, N.; Taborda, R.

2017-12-01

The validation of ground motion synthetics has received increased attention over the last few years due to the advances in physics-based deterministic and hybrid simulation methods. Unlike for low frequency simulations (f ≤ 0.5 Hz), for which it has become reasonable to expect a good match between synthetics and data, in the case of high-frequency simulations (f ≥ 1 Hz) it is not possible to match results on a wiggle-by-wiggle basis. This is mostly due to the various complexities and uncertainties involved in earthquake ground motion modeling. Therefore, in order to compare synthetics with data we turn to different time series metrics, which are used as a means to characterize how the synthetics match the data on qualitative and statistical sense. In general, these metrics provide GOF scores that measure the level of similarity in the time and frequency domains. It is common for these scores to be scaled from 0 to 10, with 10 representing a perfect match. Although using individual metrics for particular applications is considered more adequate, there is no consensus or a unified method to classify the comparison between a set of synthetic and recorded seismograms when the various metrics offer different scores. We study the relationship among these metrics through a constrained k-means clustering approach. We define 4 hypothetical stations with scores 3, 5, 7, and 9 for all metrics. We put these stations in the category of cannot-link constraints. We generate the dataset through the validation of the results from a deterministic (physics-based) ground motion simulation for a moderate magnitude earthquake in the greater Los Angeles basin using three velocity models. The maximum frequency of the simulation is 4 Hz. The dataset involves over 300 stations and 11 metrics, or features, as they are understood in the clustering process, where the metrics form a multi-dimensional space. We address the high-dimensional feature effects with a subspace-clustering analysis, generate a final labeled dataset of stations, and discuss the within-class statistical characteristics of each metric. Labeling these stations is the first step towards developing a unified metric to evaluate ground motion simulations in an application-independent manner.

Task demands determine the specificity of the search template.

PubMed

Bravo, Mary J; Farid, Hany

2012-01-01

When searching for an object, an observer holds a representation of the target in mind while scanning the scene. If the observer repeats the search, performance may become more efficient as the observer hones this target representation, or "search template," to match the specific demands of the search task. An effective search template must have two characteristics: It must reliably discriminate the target from the distractors, and it must tolerate variability in the appearance of the target. The present experiment examined how the tolerance of the search template is affected by the search task. Two groups of 18 observers trained on the same set of stimuli blocked either by target image (block-by-image group) or by target category (block-by-category group). One or two days after training, both groups were tested on a related search task. The pattern of test results revealed that the two groups of observers had developed different search templates, and that the templates of the block-by-category observers better captured the general characteristics of the category. These results demonstrate that observers match their search templates to the demands of the search task.

Measurement of left ventricular torsion using block-matching-based speckle tracking for two-dimensional echocardiography

NASA Astrophysics Data System (ADS)

Sun, Feng-Rong; Wang, Xiao-Jing; Wu, Qiang; Yao, Gui-Hua; Zhang, Yun

2013-01-01

Left ventricular (LV) torsion is a sensitive and global index of LV systolic and diastolic function, but how to noninvasively measure it is challenging. Two-dimensional echocardiography and the block-matching based speckle tracking method were used to measure LV torsion. Main advantages of the proposed method over the previous ones are summarized as follows: (1) The method is automatic, except for manually selecting some endocardium points on the end-diastolic frame in initialization step. (2) The diamond search strategy is applied, with a spatial smoothness constraint introduced into the sum of absolute differences matching criterion; and the reference frame during the search is determined adaptively. (3) The method is capable of removing abnormal measurement data automatically. The proposed method was validated against that using Doppler tissue imaging and some preliminary clinical experimental studies were presented to illustrate clinical values of the proposed method.

Inertial navigation sensor integrated motion analysis for autonomous vehicle navigation

NASA Technical Reports Server (NTRS)

Roberts, Barry; Bhanu, Bir

1992-01-01

Recent work on INS integrated motion analysis is described. Results were obtained with a maximally passive system of obstacle detection (OD) for ground-based vehicles and rotorcraft. The OD approach involves motion analysis of imagery acquired by a passive sensor in the course of vehicle travel to generate range measurements to world points within the sensor FOV. INS data and scene analysis results are used to enhance interest point selection, the matching of the interest points, and the subsequent motion-based computations, tracking, and OD. The most important lesson learned from the research described here is that the incorporation of inertial data into the motion analysis program greatly improves the analysis and makes the process more robust.

Dynamic code block size for JPEG 2000

NASA Astrophysics Data System (ADS)

Tsai, Ping-Sing; LeCornec, Yann

2008-02-01

Since the standardization of the JPEG 2000, it has found its way into many different applications such as DICOM (digital imaging and communication in medicine), satellite photography, military surveillance, digital cinema initiative, professional video cameras, and so on. The unified framework of the JPEG 2000 architecture makes practical high quality real-time compression possible even in video mode, i.e. motion JPEG 2000. In this paper, we present a study of the compression impact using dynamic code block size instead of fixed code block size as specified in the JPEG 2000 standard. The simulation results show that there is no significant impact on compression if dynamic code block sizes are used. In this study, we also unveil the advantages of using dynamic code block sizes.

Televised Whorf: Cognitive Restructuring in Advanced Foreign Language Learners as a Function of Audiovisual Media Exposure

ERIC Educational Resources Information Center

Bylund, Emanuel; Athanasopoulos, Panos

2015-01-01

The encoding of goal-oriented motion events varies across different languages. Speakers of languages without grammatical aspect (e.g., Swedish) tend to mention motion endpoints when describing events (e.g., "two nuns walk to a house") and attach importance to event endpoints when matching scenes from memory. Speakers of aspect languages…

MotorSense: Using Motion Tracking Technology to Support the Identification and Treatment of Gross-Motor Dysfunction.

PubMed

Arnedillo-Sánchez, Inmaculada; Boyle, Bryan; Bossavit, Benoît

2017-01-01

MotorSense is a motion detection and tracking technology that can be implemented across a range of environments to assist in detecting delays in gross-motor skills development. The system utilises the motion tracking functionality of Microsoft's Kinect™. It features games that require children to perform graded gross-motor tasks matched with their chronological and developmental ages. This paper describes the rationale for MotorSense, provides an overview of the functionality of the system and illustrates sample activities.

Stereomotion speed perception is contrast dependent

NASA Technical Reports Server (NTRS)

Brooks, K.

2001-01-01

The effect of contrast on the perception of stimulus speed for stereomotion and monocular lateral motion was investigated for successive matches in random-dot stimuli. The familiar 'Thompson effect'--that a reduction in contrast leads to a reduction in perceived speed--was found in similar proportions for both binocular images moving in depth, and for monocular images translating laterally. This result is consistent with the idea that the monocular motion system has a significant input to the stereomotion system, and dominates the speed percept for approaching motion.

Oncoplastic round block technique has comparable operative parameters as standard wide local excision: a matched case-control study.

PubMed

Lim, Geok-Hoon; Allen, John Carson; Ng, Ruey Pyng

2017-08-01

Although oncoplastic breast surgery is used to resect larger tumors with lower re-excision rates compared to standard wide local excision (sWLE), criticisms of oncoplastic surgery include a longer-albeit, well concealed-scar, longer operating time and hospital stay, and increased risk of complications. Round block technique has been reported to be very suitable for patients with relatively smaller breasts and minimal ptosis. We aim to determine if round block technique will result in operative parameters comparable with sWLE. Breast cancer patients who underwent a round block procedure from 1st May 2014 to 31st January 2016 were included in the study. These patients were then matched for the type of axillary procedure, on a one to one basis, with breast cancer patients who had undergone sWLE from 1st August 2011 to 31st January 2016. The operative parameters between the 2 groups were compared. 22 patients were included in the study. Patient demographics and histologic parameters were similar in the 2 groups. No complications were reported in either group. The mean operating time was 122 and 114 minutes in the round block and sWLE groups, respectively (P=0.64). Length of stay was similar in the 2 groups (P=0.11). Round block patients had better cosmesis and lower re-excision rates. A higher rate of recurrence was observed in the sWLE group. The round block technique has comparable operative parameters to sWLE with no evidence of increased complications. Lower re-excision rate and better cosmesis were observed in the round block patients suggesting that the round block technique is not only comparable in general, but may have advantages to sWLE in selected cases.

Ten days of simulated live high:train low altitude training increases Hbmass in elite water polo players.

PubMed

Garvican-Lewis, Laura A; Clark, Sally A; Polglaze, Ted; McFadden, Greg; Gore, Christopher J

2013-12-01

Water polo requires high aerobic power to meet the demands of match play. Live high:train low (LHTL) may enhance aerobic capacity at sea level. Before the Olympics, the Australian women's water polo team utilised LHTL in an attempt to enhance aerobic fitness. Over 6 months, 11 players completed three normobaric LHTL exposures (block 1:11 days at 3000 m; block 2+3:9 days at 2500 m, 11 days normoxia, 10 days at 2800 m). Haemoglobin mass (Hbmass) was measured through carbon monoxide-rebreathing. Before each block, the relationship between Hbmass and water polo-specific aerobic fitness was investigated using the Multistage Shuttle Swim Test (MSST). Effect size statistics were adopted with likely, highly likely and almost certainly results being >75%, >95%, >99%, respectively. A Pearson product moment correlation was used to characterise the association between pooled data of Hbmass and MSST. Hbmass (mean ± SD, pre 721 ± 66 g) likely increased after block 1 and almost certainly after block 2+3 (% change; 90% confidence limits: block 1: 3.7%; 1.3-6.2%, block 2+3: 4.5%; 3.8-5.1%) and the net effect was almost certainly higher after block 2+3 than before block 1 (pre) by 8.5%; 7.3-9.7%. There was a very large correlation between Hbmass (g/kg) and MSST score (r=0.73). LHTL exposures of <2 weeks induced approximately 4% increase in Hbmass of water polo players. Extra Hbmass may increase aerobic power, but since match performance is nuanced by many factors it is impossible to ascertain whether the increased Hbmass contributed to Australia's Bronze medal.

Consensus of satellite cluster flight using an energy-matching optimal control method

NASA Astrophysics Data System (ADS)

Luo, Jianjun; Zhou, Liang; Zhang, Bo

2017-11-01

This paper presents an optimal control method for consensus of satellite cluster flight under a kind of energy matching condition. Firstly, the relation between energy matching and satellite periodically bounded relative motion is analyzed, and the satellite energy matching principle is applied to configure the initial conditions. Then, period-delayed errors are adopted as state variables to establish the period-delayed errors dynamics models of a single satellite and the cluster. Next a novel satellite cluster feedback control protocol with coupling gain is designed, so that the satellite cluster periodically bounded relative motion consensus problem (period-delayed errors state consensus problem) is transformed to the stability of a set of matrices with the same low dimension. Based on the consensus region theory in the research of multi-agent system consensus issues, the coupling gain can be obtained to satisfy the requirement of consensus region and decouple the satellite cluster information topology and the feedback control gain matrix, which can be determined by Linear quadratic regulator (LQR) optimal method. This method can realize the consensus of satellite cluster period-delayed errors, leading to the consistency of semi-major axes (SMA) and the energy-matching of satellite cluster. Then satellites can emerge the global coordinative cluster behavior. Finally the feasibility and effectiveness of the present energy-matching optimal consensus for satellite cluster flight is verified through numerical simulations.

Predicting 2D target velocity cannot help 2D motion integration for smooth pursuit initiation.

PubMed

Montagnini, Anna; Spering, Miriam; Masson, Guillaume S

2006-12-01

Smooth pursuit eye movements reflect the temporal dynamics of bidimensional (2D) visual motion integration. When tracking a single, tilted line, initial pursuit direction is biased toward unidimensional (1D) edge motion signals, which are orthogonal to the line orientation. Over 200 ms, tracking direction is slowly corrected to finally match the 2D object motion during steady-state pursuit. We now show that repetition of line orientation and/or motion direction does not eliminate the transient tracking direction error nor change the time course of pursuit correction. Nonetheless, multiple successive presentations of a single orientation/direction condition elicit robust anticipatory pursuit eye movements that always go in the 2D object motion direction not the 1D edge motion direction. These results demonstrate that predictive signals about target motion cannot be used for an efficient integration of ambiguous velocity signals at pursuit initiation.

Dynamic Response-by-Response Models of Matching Behavior in Rhesus Monkeys

ERIC Educational Resources Information Center

Lau, Brian; Glimcher, Paul W.

2005-01-01

We studied the choice behavior of 2 monkeys in a discrete-trial task with reinforcement contingencies similar to those Herrnstein (1961) used when he described the matching law. In each session, the monkeys experienced blocks of discrete trials at different relative-reinforcer frequencies or magnitudes with unsignalled transitions between the…

How the continents deform: The evidence from tectonic geodesy

USGS Publications Warehouse

Thatcher, Wayne R.

2009-01-01

Space geodesy now provides quantitative maps of the surface velocity field within tectonically active regions, supplying constraints on the spatial distribution of deformation, the forces that drive it, and the brittle and ductile properties of continental lithosphere. Deformation is usefully described as relative motions among elastic blocks and is block-like because major faults are weaker than adjacent intact crust. Despite similarities, continental block kinematics differs from global plate tectonics: blocks are much smaller, typically ∼100–1000 km in size; departures from block rigidity are sometimes measurable; and blocks evolve over ∼1–10 Ma timescales, particularly near their often geometrically irregular boundaries. Quantitatively relating deformation to the forces that drive it requires simplifying assumptions about the strength distribution in the lithosphere. If brittle/elastic crust is strongest, interactions among blocks control the deformation. If ductile lithosphere is the stronger, its flow properties determine the surface deformation, and a continuum approach is preferable.

Short-term Clinical Results of Manipulation Under Ultrasound-Guided Brachial Plexus Block in Patients with Idiopathic Frozen Shoulder and Diabetic Secondary Frozen Shoulder.

PubMed

Ando, Akira; Hamada, Junichiro; Hagiwara, Yoshihiro; Sekiguchi, Takuya; Koide, Masashi; Itoi, Eiji

2018-01-01

This study examined the effectiveness of manipulation under ultrasound-guided brachial plexus block in patients with recalcitrant idiopathic frozen shoulder and diabetic secondary frozen shoulder (diabetic frozen shoulder). Forty-four idiopathic frozen shoulders and 10 diabetic frozen shoulders with failed conservative treatment for at least 3 months were included in this study. The manipulation was performed under ultrasound-guided brachial plexus block and visual analogue scale, range of motion, and Constant scores were measured before manipulation and at the last follow-up examination. No major complications were observed during the procedure. Sufficient improvement was not obtained in two patients during the procedure and to avoid complications, the procedure was discontinued and subsequently arthroscopic capsular release was performed. Visual analogue scale, range of motion towards all directions, and Constant scores were significantly improved after the manipulation in both the idiopathic frozen shoulder and diabetic frozen shoulder groups, however the diabetic group showed inferior results compared with those of the idiopathic group. This manipulation was effective and shortened the duration of symptoms in most of the idiopathic and diabetic frozen shoulders without major complications during the procedure. Diabetic frozen shoulder showed inferior clinical results and difficulty in recovery in range of motion, which indicated that diabetic frozen shoulder should be discussed as a different entity.

Back-arc spreading of the northern Izu-Ogasawara (Bonin) Islands arc clarified by GPS data

NASA Astrophysics Data System (ADS)

Nishimura, Takuya

2011-11-01

We examined GPS data in the northwestern Pacific region, which includes the Izu-Ogasawara (Bonin)-Mariana (IBM) arc and the Japan arc. GPS velocity vectors on the Izu Islands, including Hachijo-jima and Aoga-shima, show systematic eastward movement deviating from that predicted by the rigid rotation of the Philippine Sea plate; this deviation supports the active back-arc spreading model suggested by previous geological studies. The results of a statistical F-test analysis with 99% confidence level showed that the forearc of the Izu Islands arc has an independent motion with respect to the rigid part of the Philippine Sea plate. We developed a kinematic block-fault model to estimate both rigid rotations of crustal blocks and elastic deformation due to locked faults on the block boundaries. The model suggests that the back-arc opening rate along the Izu back-arc rift zone ranges from 2 mm/yr at its southern end to 9 mm/yr near Miyake-jima, its northern end. It also predicts 23-28 mm/yr of relative motion along the Sagami Trough in the direction of ~ N25°W, where the Izu forearc subducts beneath central Japan. The orientation of this motion is supported by slip vectors of recent medium-size earthquakes, repeated slow-slip events, and the 1923 M = 7.9 Kanto earthquake.

Integration of visual and non-visual self-motion cues during voluntary head movements in the human brain.

PubMed

Schindler, Andreas; Bartels, Andreas

2018-05-15

Our phenomenological experience of the stable world is maintained by continuous integration of visual self-motion with extra-retinal signals. However, due to conventional constraints of fMRI acquisition in humans, neural responses to visuo-vestibular integration have only been studied using artificial stimuli, in the absence of voluntary head-motion. We here circumvented these limitations and let participants to move their heads during scanning. The slow dynamics of the BOLD signal allowed us to acquire neural signal related to head motion after the observer's head was stabilized by inflatable aircushions. Visual stimuli were presented on head-fixed display goggles and updated in real time as a function of head-motion that was tracked using an external camera. Two conditions simulated forward translation of the participant. During physical head rotation, the congruent condition simulated a stable world, whereas the incongruent condition added arbitrary lateral motion. Importantly, both conditions were precisely matched in visual properties and head-rotation. By comparing congruent with incongruent conditions we found evidence consistent with the multi-modal integration of visual cues with head motion into a coherent "stable world" percept in the parietal operculum and in an anterior part of parieto-insular cortex (aPIC). In the visual motion network, human regions MST, a dorsal part of VIP, the cingulate sulcus visual area (CSv) and a region in precuneus (Pc) showed differential responses to the same contrast. The results demonstrate for the first time neural multimodal interactions between precisely matched congruent versus incongruent visual and non-visual cues during physical head-movement in the human brain. The methodological approach opens the path to a new class of fMRI studies with unprecedented temporal and spatial control over visuo-vestibular stimulation. Copyright © 2018 Elsevier Inc. All rights reserved.

Minimization of Retinal Slip Cannot Explain Human Smooth-Pursuit Eye Movements

NASA Technical Reports Server (NTRS)

Stone, Leland S.; Beutter, Brent R.; Null, Cynthia H. (Technical Monitor)

1998-01-01

Existing models assume that pursuit attempts a direct minimization of retinal image motion or "slip" (e.g. Robinson et al., 1986; Krauzlis & Weisberger, 1989). Using occluded line-figure stimuli, we have previously shown that humans can accurately pursue stimuli for which perfect tracking does not zero retinal slip (Neurologic ARCO). These findings are inconsistent with the standard control strategy of matching eye motion to a target-motion signal reconstructed by adding retinal slip and eye motion, but consistent with a visual front-end which estimates target motion via a global spatio-temporal integration for pursuit and perception. Another possible explanation is that pursuit simply attempts to minimize slip perpendicular to the segments (and neglects parallel "sliding" motion). To resolve this, 4 observers (3 naive) were asked to pursue the center of 2 types of stimuli with identical velocity-space descriptions and matched motion energy. The line-figure "diamond" stimulus was viewed through 2 invisible 3 deg-wide vertical apertures (38 cd/m2 equal to background) such that only the sinusoidal motion of 4 oblique line segments (44 cd/m2 was visible. The "cross" was identical except that the segments exchanged positions. Two trajectories (8's and infinity's) with 4 possible initial directions were randomly interleaved (1.25 cycles, 2.5s period, Ax = Ay = 1.4 deg). In 91% of trials, the diamond appeared rigid. Correspondingly, pursuit was vigorous (mean Again: 0.74) with a V/H aspect ratio approx. 1 (mean: 0.9). Despite a valid rigid solution, the cross however appeared rigid in 8% of trials. Correspondingly, pursuit was weaker (mean Hgain: 0.38) with an incorrect aspect ratio (mean: 1.5). If pursuit were just minimizing perpendicular slip, performance would be the same in both conditions.

Fault locking, block rotation and crustal deformation in the Pacific Northwest

USGS Publications Warehouse

McCaffrey, R.; Qamar, A.I.; King, R.W.; Wells, R.; Khazaradze, G.; Williams, C.A.; Stevens, C.W.; Vollick, J.J.; Zwick, P.C.

2007-01-01

We interpret Global Positioning System (GPS) measurements in the northwestern United States and adjacent parts of western Canada to describe relative motions of crustal blocks, locking on faults and permanent deformation associated with convergence between the Juan de Fuca and North American plates. To estimate angular velocities of the oceanic Juan de Fuca and Explorer plates and several continental crustal blocks, we invert the GPS velocities together with seafloor spreading rates, earthquake slip vector azimuths and fault slip azimuths and rates. We also determine the degree to which faults are either creeping aseismically or, alternatively, locked on the block-bounding faults. The Cascadia subduction thrust is locked mainly offshore, except in central Oregon, where locking extends inland. Most of Oregon and southwest Washington rotate clockwise relative to North America at rates of 0.4-1.0?? Myr-1. No shear or extension along the Cascades volcanic arc has occurred at the mm/yr level during the past decade, suggesting that the shear deformation extending northward from the Walker Lane and eastern California shear zone south of Oregon is largely accommodated by block rotation in Oregon. The general agreement of vertical axis rotation rates derived from GPS velocities with those estimated from palaeomagnetic declination anomalies suggests that the rotations have been relatively steady for 10-15 Ma. Additional permanent dextral shear is indicated within the Oregon Coast Range near the coast. Block rotations in the Pacific Northwest do not result in net westward flux of crustal material - the crust is simply spinning and not escaping. On Vancouver Island, where the convergence obliquity is less than in Oregon and Washington, the contractional strain at the coast is more aligned with Juan de Fuca-North America motion. GPS velocities are fit significantly better when Vancouver Island and the southern Coast Mountains move relative to North America in a block-like fashion. The relative motions of the Oregon, western Washington and Vancouver Island crustal blocks indicate that the rate of permanent shortening, the type that causes upper plate earthquakes, across the Puget Sound region is 4.4 ?? 0.3 mm yr-1. This shortening is likely distributed over several faults but GPS data alone cannot determine the partitioning of slip on them. The transition from predominantly shear deformation within the continent south of the Mendocino Triple Junction to predominantly block rotations north of it is similar to changes in tectonic style at other transitions from shear to subduction. This similarity suggests that crustal block rotations are enhanced in the vicinity of subduction zones possibly due to lower resisting stress. ?? 2007 The Authors Journal compilation ?? 2007 RAS.

Self-similarity and self-inversion of quasicrystals

NASA Astrophysics Data System (ADS)

Madison, A. E.

2014-08-01

The discovery of quasicrystals played a revolutionary role in the condensed matter science and forced to renounce the dogma of the classical crystallography that the regular filling of the space by identical blocks is reduced solely to the Fedorov space groups. It is shown that aperiodic crystals, apart from the similarity, exhibit the self-inversion property. In a broadened sense, the self-inversion implies the possible composition of the inversion with translations, rotations, and homothety, whereas pure reflection by itself in a circle can be absent as an independent symmetry element. It is demonstrated that the symmetry of aperiodic tilings is described by Schottky groups (which belong to a particular type of Kleinian groups generated by the linear fractional Möbius transformations); in the theory of aperiodic crystals, the Schottky groups play the same role that the Fedorov groups play in the theory of crystal lattices. The local matching rules for the Penrose fractal tiling are derived, the problem of choice of the fundamental region of the group of motions of a quasicrystal is discussed, and the relation between the symmetry of aperiodic tilings and the symmetry of constructive fractals is analyzed.

Pilot-Induced Oscillation Prediction With Three Levels of Simulation Motion Displacement

NASA Technical Reports Server (NTRS)

Schroeder, Jeffery A.; Chung, William W. Y.; Tran, Duc T.; Laforce, Soren; Bengford, Norman J.

2001-01-01

Simulator motion platform characteristics were examined to determine if the amount of motion affects pilot-induced oscillation (PIO) prediction. Five test pilots evaluated how susceptible 18 different sets of pitch dynamics were to PIOs with three different levels of simulation motion platform displacement: large, small, and none. The pitch dynamics were those of a previous in-flight experiment, some of which elicited PIOs These in-flight results served as truth data for the simulation. As such, the in-flight experiment was replicated as much as possible. Objective and subjective data were collected and analyzed With large motion, PIO and handling qualities ratings matched the flight data more closely than did small motion or no motion. Also, regardless of the aircraft dynamics, large motion increased pilot confidence in assigning handling qualifies ratings, reduced safety pilot trips, and lowered touchdown velocities. While both large and small motion provided a pitch rate cue of high fidelity, only large motion presented the pilot with a high fidelity vertical acceleration cue.

Neural correlates of coherent and biological motion perception in autism.

PubMed

Koldewyn, Kami; Whitney, David; Rivera, Susan M

2011-09-01

Recent evidence suggests those with autism may be generally impaired in visual motion perception. To examine this, we investigated both coherent and biological motion processing in adolescents with autism employing both psychophysical and fMRI methods. Those with autism performed as well as matched controls during coherent motion perception but had significantly higher thresholds for biological motion perception. The autism group showed reduced posterior Superior Temporal Sulcus (pSTS), parietal and frontal activity during a biological motion task while showing similar levels of activity in MT+/V5 during both coherent and biological motion trials. Activity in MT+/V5 was predictive of individual coherent motion thresholds in both groups. Activity in dorsolateral prefrontal cortex (DLPFC) and pSTS was predictive of biological motion thresholds in control participants but not in those with autism. Notably, however, activity in DLPFC was negatively related to autism symptom severity. These results suggest that impairments in higher-order social or attentional networks may underlie visual motion deficits observed in autism. © 2011 Blackwell Publishing Ltd.

Neural correlates of coherent and biological motion perception in autism

PubMed Central

Koldewyn, Kami; Whitney, David; Rivera, Susan M.

2011-01-01

Recent evidence suggests those with autism may be generally impaired in visual motion perception. To examine this, we investigated both coherent and biological motion processing in adolescents with autism employing both psychophysical and fMRI methods. Those with autism performed as well as matched controls during coherent motion perception but had significantly higher thresholds for biological motion perception. The autism group showed reduced posterior Superior Temporal Sulcus (pSTS), parietal and frontal activity during a biological motion task while showing similar levels of activity in MT+/V5 during both coherent and biological motion trials. Activity in MT+/V5 was predictive of individual coherent motion thresholds in both groups. Activity in dorsolateral prefrontal cortex (DLPFC) and pSTS was predictive of biological motion thresholds in control participants but not in those with autism. Notably, however, activity in DLPFC was negatively related to autism symptom severity. These results suggest that impairments in higher-order social or attentional networks may underlie visual motion deficits observed in autism. PMID:21884323

Decoding Actions and Emotions in Deaf Children: Evidence from a Biological Motion Task

ERIC Educational Resources Information Center

Ludlow, Amanda Katherine; Heaton, Pamela; Deruelle, Christine

2013-01-01

This study aimed to explore the recognition of emotional and non-emotional biological movements in children with severe and profound deafness. Twenty-four deaf children, together with 24 control children matched on mental age and 24 control children matched on chronological age, were asked to identify a person's actions, subjective states,…

Autogenic-feedback training exercise is superior to promethazine for control of motion sickness symptoms

NASA Technical Reports Server (NTRS)

Cowings, P. S.; Toscano, W. B.

2000-01-01

Motion sickness symptoms affect approximately 50% of the crew during space travel and are commonly treated with intramuscular injections of promethazine. The purpose of this paper is to compare the effectiveness of three treatments for motion sickness: intramuscular injections (i.m.) of promethazine, a physiological training method (autogenic-feedback training exercise [AFTE]), and a no-treatment control. An earlier study tested the effects of promethazine on cognitive and psychomotor performance and motion sickness tolerance in a rotating chair. For the present paper, motion sickness tolerance, symptom reports, and physiological responses of these subjects were compared to matched subjects selected from an existing database who received either AFTE or no treatment. Three groups of 11 men, between the ages of 33 and 40 years, were matched on the number of rotations tolerated during their initial rotating-chair motion sickness test. The motion sickness test procedures and the 7-day interval between tests were the same for all subjects. The drug group was tested under four treatment conditions: baseline (no injections), a 25 mg dose of promethazine, a 50 mg dose of promethazine, and a placebo of sterile saline. AFTE subjects were given four 30-minute AFTE sessions before their second, third, and fourth motion sickness tests (6 hours total). The no-treatment control subjects were only given the four rotating-chair tests. Motion sickness tolerance was significantly increased after 4 hours of AFTE when compared to either 25 mg (p < 0.00003) or 50 mg (p < 0.00001) of promethazine. The control and promethazine groups did not differ. AFTE subjects reported fewer or no symptoms at higher rotational velocities than subjects in the control or promethazine groups. The primary physiological effect of promethazine was an inhibition of skin conductance level. The AFTE group showed significantly less heart rate and skin conductance variability during motion sickness tests administered after training.

Autogenic-feedback training exercise is superior to promethazine for control of motion sickness symptoms.

PubMed

Cowings, P S; Toscano, W B

2000-10-01

Motion sickness symptoms affect approximately 50% of the crew during space travel and are commonly treated with intramuscular injections of promethazine. The purpose of this paper is to compare the effectiveness of three treatments for motion sickness: intramuscular injections (i.m.) of promethazine, a physiological training method (autogenic-feedback training exercise [AFTE]), and a no-treatment control. An earlier study tested the effects of promethazine on cognitive and psychomotor performance and motion sickness tolerance in a rotating chair. For the present paper, motion sickness tolerance, symptom reports, and physiological responses of these subjects were compared to matched subjects selected from an existing database who received either AFTE or no treatment. Three groups of 11 men, between the ages of 33 and 40 years, were matched on the number of rotations tolerated during their initial rotating-chair motion sickness test. The motion sickness test procedures and the 7-day interval between tests were the same for all subjects. The drug group was tested under four treatment conditions: baseline (no injections), a 25 mg dose of promethazine, a 50 mg dose of promethazine, and a placebo of sterile saline. AFTE subjects were given four 30-minute AFTE sessions before their second, third, and fourth motion sickness tests (6 hours total). The no-treatment control subjects were only given the four rotating-chair tests. Motion sickness tolerance was significantly increased after 4 hours of AFTE when compared to either 25 mg (p < 0.00003) or 50 mg (p < 0.00001) of promethazine. The control and promethazine groups did not differ. AFTE subjects reported fewer or no symptoms at higher rotational velocities than subjects in the control or promethazine groups. The primary physiological effect of promethazine was an inhibition of skin conductance level. The AFTE group showed significantly less heart rate and skin conductance variability during motion sickness tests administered after training.

Low Cognitive Load and Reduced Arousal Impede Practice Effects on Executive Functioning, Metacognitive Confidence and Decision Making

PubMed Central

Jackson, Simon A.; Kleitman, Sabina; Aidman, Eugene

2014-01-01

The present study investigated the effects of low cognitive workload and the absence of arousal induced via external physical stimulation (motion) on practice-related improvements in executive (inhibitory) control, short-term memory, metacognitive monitoring and decision making. A total of 70 office workers performed low and moderately engaging passenger tasks in two successive 20-minute simulated drives and repeated a battery of decision making and inhibitory control tests three times – before, between and after these drives. For half the participants, visual simulation was synchronised with (moderately arousing) motion generated through LAnd Motion Platform, with vibration levels corresponding to a well-maintained unsealed road. The other half performed the same simulated drive without motion. Participants’ performance significantly improved over the three test blocks, which is indicative of typical practice effects. The magnitude of these improvements was the highest when both motion and moderate cognitive load were present. The same effects declined either in the absence of motion (low arousal) or following a low cognitive workload task, thus suggesting two distinct pathways through which practice-related improvements in cognitive performance may be hampered. Practice, however, degraded certain aspects of metacognitive performance, as participants became less likely to detect incorrect decisions in the decision-making test with each subsequent test block. Implications include consideration of low cognitive load and arousal as factors responsible for performance decline and targets for the development of interventions/strategies in low load/arousal conditions such as autonomous vehicle operations and highway driving. PMID:25549327

Tectonic movements along the Anegada Passage derived from GPS Observations (2008-2017)

NASA Astrophysics Data System (ADS)

Liu, H.; Wang, G.

2017-12-01

The Anegada Passage system, mainly includes the Virgin Islands Basin (VIB), Anegada Gap, and the Sombrero Basin, are located within the tectonically complex plate boundary zone between the North America and Caribbean plates. It separated the Puerto Rico and Northern Virgin Islands (PRNVI) block from St. Croix and Anguilla. Long-term seismic observations indicated that this region still faces high risk from earthquakes. This study used current GPS geodesy infrastructure in the Northeastern Caribbean region, which includes high densely GPS stations on PRNVI block and northern Lesser Antilles and a stable PRNVI reference frame (SPRNVIRF). Current GPS geodesy infrastructure in the PRVI region makes it possible to precisely delineate minor tectonic motions (1 to 2 mm/year) within the northeastern Caribbean region. The carrier phase Double-Difference (DD) and Precise Point Positioning (PPP) post-processing methods are both used to processing GPS data. Over ten years of GPS observations indicate that the St. Croix Island is moving away from the PRVI block toward southeast with a velocity of 1.8 ± 0.2 mm/year; there is not considerable relative motions between the Saint Martin Island and the PRVI block. The Saint Martin Island is located at the south side of the Anegada Gap. The GPS and seismic observations along the two sides of the Anegada passage suggest that the west segment (VIB) of the passage retains active, while the east segment is presently inactive. The Virgin Islands basin presently experiences left-lateral motion in a nearly east-west direction with a velocity of about 1.2 mm/year and an extension in a nearly north-south direction with a velocity of about 1.3 mm/year. The quantitative measurements derived from GPS observations would improve seismic hazard assessment in the Anegada Passage region.

Physics Notes

ERIC Educational Resources Information Center

School Science Review, 1972

1972-01-01

Short articles describe a method of introducing the study of simple harmonic motion, and suggest models that are analogues for impedence matching, electrical transformers, and birefringent crystals. (AL)

Preliminary deformation model for National Seismic Hazard map of Indonesia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meilano, Irwan; Gunawan, Endra; Sarsito, Dina

Preliminary deformation model for the Indonesia’s National Seismic Hazard (NSH) map is constructed as the block rotation and strain accumulation function at the elastic half-space. Deformation due to rigid body motion is estimated by rotating six tectonic blocks in Indonesia. The interseismic deformation due to subduction is estimated by assuming coupling on subduction interface while deformation at active fault is calculated by assuming each of the fault‘s segment slips beneath a locking depth or in combination with creeping in a shallower part. This research shows that rigid body motion dominates the deformation pattern with magnitude more than 15 mm/year, except inmore » the narrow area near subduction zones and active faults where significant deformation reach to 25 mm/year.« less

Emergence of collective motion in bacterial suspensions

NASA Astrophysics Data System (ADS)

Liu, Song

It is well known that bacterial suspensions will exhibit collective motion at high concentrations, in which both steric and hydrodynamic interactions play important roles. We aim to investigate whether steric and hydrodynamic interactions are of equal importance to the emergence of collective motion. Here we will present our efforts to experimentally tune the relative strength of these interactions in bacterial suspensions. Our preliminary results suggest that the transition to collective motion may depend on the interplay between steric and hydrodynamic interactions. Mailing address: Room 306 Science Centre North Block, The Chinese University of Hong Kong, Shatin, N.T. Hong Kong SAR. Phone: +852-3943-6354. Fax: +852-2603-5204. E-mail: songliuphy@gmail.com.

Robust image matching via ORB feature and VFC for mismatch removal

NASA Astrophysics Data System (ADS)

Ma, Tao; Fu, Wenxing; Fang, Bin; Hu, Fangyu; Quan, Siwen; Ma, Jie

2018-03-01

Image matching is at the base of many image processing and computer vision problems, such as object recognition or structure from motion. Current methods rely on good feature descriptors and mismatch removal strategies for detection and matching. In this paper, we proposed a robust image match approach based on ORB feature and VFC for mismatch removal. ORB (Oriented FAST and Rotated BRIEF) is an outstanding feature, it has the same performance as SIFT with lower cost. VFC (Vector Field Consensus) is a state-of-the-art mismatch removing method. The experiment results demonstrate that our method is efficient and robust.

Identification of pre-impact conditions of a cyclist involved in a vehicle-bicycle accident using an optimized MADYMO reconstruction combined with motion capture.

PubMed

Sun, Jie; Li, Zhengdong; Pan, Shaoyou; Feng, Hao; Shao, Yu; Liu, Ningguo; Huang, Ping; Zou, Donghua; Chen, Yijiu

2018-05-01

The aim of the present study was to develop an improved method, using MADYMO multi-body simulation software combined with an optimization method and three-dimensional (3D) motion capture, for identifying the pre-impact conditions of a cyclist (walking or cycling) involved in a vehicle-bicycle accident. First, a 3D motion capture system was used to analyze coupled motions of a volunteer while walking and cycling. The motion capture results were used to define the posture of the human model during walking and cycling simulations. Then, cyclist, bicycle and vehicle models were developed. Pre-impact parameters of the models were treated as unknown design variables. Finally, a multi-objective genetic algorithm, the nondominated sorting genetic algorithm II, was used to find optimal solutions. The objective functions of the walk parameter were significantly lower than cycle parameter; thus, the cyclist was more likely to have been walking with the bicycle than riding the bicycle. In the most closely matched result found, all observed contact points matched and the injury parameters correlated well with the real injuries sustained by the cyclist. Based on the real accident reconstruction, the present study indicates that MADYMO multi-body simulation software, combined with an optimization method and 3D motion capture, can be used to identify the pre-impact conditions of a cyclist involved in a vehicle-bicycle accident. Copyright © 2018. Published by Elsevier Ltd.

Differences in shoaling behavior in two species of freshwater fish (Danio rerio and Hyphessobrycon herbertaxelrodi).

PubMed

Gimeno, Elisabet; Quera, Vicenç; Beltran, Francesc S; Dolado, Ruth

2016-11-01

Fish can gain significant adaptive advantages when living in a group and they exhibit a wide variety of types of collective motion. The scientific literature recognizes 2 main patterns: shoals (aggregations of individuals that remain close to each other), and schools (aggregations of aligned, or polarized, individuals). We analyzed the collective motion of 2 social fish species, zebrafish (Danio rerio) and black neon tetra (Hyphessobrycon herbertaxelrodi), and compared their patterns of movement and the effect of group size and environmental constraints such as water column height and tank geometry on the collective motion of both species. We recorded the movement of groups of fish (n = 10 and n = 20) using 2 tank geometries: a rectangular shape and a rectangular shape with rounded corners; and we also manipulated the water column height (15 and 25 cm). We extracted the individual fish trajectories and calculated indices of cohesion, coordination, group density and group shape. The results showed that the 2 species had different types of collective motion: the zebrafish's global motion matched that of a shoal, while the black neon tetra's motion matched that of a school. Indirect evidence indicated that the 2 species tended to occupy the vertical space differently while swimming in a group. Finally, we found that tank geometry did not affect group polarization, whereas group size had an effect on black neon tetra density, which was higher in small group sizes than in large ones. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Day Care and Federal Funding: Current Problems and Possible Solutions.

ERIC Educational Resources Information Center

Dail, Paula W.

The current policy of consolidating funding for all Title XX programs into block grants presents problems for day care users who increasingly must begin to explore alternatives to federally funded day care services. The block grants are problematic because they (1) are undesignated and can be used as the state wills, (2) have no matching fund…

Searching for High Proper Motion Sources Towards the Galactic Center using Convolution Neural Networks

NASA Astrophysics Data System (ADS)

Giongo Fernandes, Alexandre; Benjamin, Robert A.; Babler, Brian

2018-01-01

Two sets of infrared images of the Galactic Center region (|L|< 1 degree and |B| < 0.75 degrees) taken by the Spitzer Space Telescope in IRAC 3.6 micron and 4.5 micron bands are searched for high proper motion objects (> 100 mas/year). The two image sets come from GALCEN observations in 2005 and GLIMPSE proper observations in 2015 with matched observation modes. We use three different methods to search for these objects in extremely crowded fields: (1) comparing matched point source lists, (2) crowd sourcing by several college introductory astronomy classes in the state of Wisconsin (700 volunteers), and (3) convolutional neural networks trained using objects from the previous two methods. Before our search six high proper objects were known, four of which were found by the VVV near-infrared Galactic plane survey. We compare and describe our methods for this search, and present a preliminary catalog of high proper motions objects.

Contemporary horizontal crustal movement estimation for northwestern Vietnam inferred from repeated GPS measurements

NASA Astrophysics Data System (ADS)

Duong, Nguyen Anh; Sagiya, Takeshi; Kimata, Fumiaki; To, Tran Dinh; Hai, Vy Quoc; Cong, Duong Chi; Binh, Nguyen Xuan; Xuyen, Nguyen Dinh

2013-12-01

We present a horizontal velocity field determined from a GPS network with 22 sites surveyed from 2001 to 2012 in northwestern Vietnam. The velocity is accurately estimated at each site by fitting a linear trend to each coordinate time series, after accounting for coseismic displacements caused by the 2004 Sumatra and the 2011 Tohoku earthquakes using static fault models. Considering the coseismic effects of the earthquakes, the motion of northwestern Vietnam is 34.3 ± 0.7 mm/yr at an azimuth of N108° ± 0.7°E in ITRF2008. This motion is close to, but slightly different from, that of the South China block. The area is in a transition zone between this block, the Sundaland block, and the Baoshan sub-block. At the local scale, a detailed estimation of the crustal deformation across major fault zones is geodetically revealed for the first time. We identify a locking depth of 15.3 ± 9.8 km with an accumulating left-lateral slip rate of 1.8 ± 0.3 mm/yr for the Dien Bien Phu fault, and a shallow locking depth with a right-lateral slip rate of 1.0 ± 0.6 mm/yr for the Son La and Da River faults.

Plate tectonics and crustal deformation around the Japanese Islands

NASA Technical Reports Server (NTRS)

Hashimoto, Manabu; Jackson, David D.

1993-01-01

We analyze over a century of geodetic data to study crustal deformation and plate motion around the Japanese Islands, using the block-fault model for crustal deformation developed by Matsu'ura et al. (1986). We model the area including the Japanese Islands with 19 crustal blocks and 104 faults based on the distribution of active faults and seismicity. Geodetic data are used to obtain block motions and average slip rates of faults. This geodetic model predicts that the Pacific plate moves N deg 69 +/- 2 deg W at about 80 +/- 3 mm/yr relative to the Eurasian plate which is much lower than that predicted in geologic models. Substantial aseismic slip occurs on the subduction boundaries. The block containing the Izu Peninsula may be separated from the rigid part of the Philippine Sea plate. The faults on the coast of Japan Sea and the western part of the Median Tectonic Line have slip rates exceeding 4 mm/yr, while the Fossa Magna does not play an important role in the tectonics of the central Japan. The geodetic model requires the division of northeastern Japan, contrary to the hypothesis that northeastern Japan is a part of the North American plate. Owing to rapid convergence, the seismic risk in the Nankai trough may be larger than that of the Tokai gap.

Long-Term Interference at the Semantic Level: Evidence from Blocked-Cyclic Picture Matching

ERIC Educational Resources Information Center

Wei, Tao; Schnur, Tatiana T.

2016-01-01

Processing semantically related stimuli creates interference across various domains of cognition, including language and memory. In this study, we identify the locus and mechanism of interference when retrieving meanings associated with words and pictures. Subjects matched a probe stimulus (e.g., cat) to its associated target picture (e.g., yarn)…

An active-optics image-motion compensation technology application for high-speed searching and infrared detection system

NASA Astrophysics Data System (ADS)

Wu, Jianping; Lu, Fei; Zou, Kai; Yan, Hong; Wan, Min; Kuang, Yan; Zhou, Yanqing

2018-03-01

An ultra-high angular velocity and minor-caliber high-precision stably control technology application for active-optics image-motion compensation, is put forward innovatively in this paper. The image blur problem due to several 100°/s high-velocity relative motion between imaging system and target is theoretically analyzed. The velocity match model of detection system and active optics compensation system is built, and active optics image motion compensation platform experiment parameters are designed. Several 100°/s high-velocity high-precision control optics compensation technology is studied and implemented. The relative motion velocity is up to 250°/s, and image motion amplitude is more than 20 pixel. After the active optics compensation, motion blur is less than one pixel. The bottleneck technology of ultra-high angular velocity and long exposure time in searching and infrared detection system is successfully broke through.

Fast antibody fragment motion: flexible linkers act as entropic spring

PubMed Central

Stingaciu, Laura R.; Ivanova, Oxana; Ohl, Michael; Biehl, Ralf; Richter, Dieter

2016-01-01

A flexible linker region between three fragments allows antibodies to adjust their binding sites to an antigen or receptor. Using Neutron Spin Echo Spectroscopy we observed fragment motion on a timescale of 7 ns with motional amplitudes of about 1 nm relative to each other. The mechanistic complexity of the linker region can be described by a spring model with Brownian motion of the fragments in a harmonic potential. Displacements, timescale, friction and force constant of the underlying dynamics are accessed. The force constant exhibits a similar strength to an entropic spring, with friction of the fragment matching the unbound state. The observed fast motions are fluctuations in pre-existing equilibrium configurations. The Brownian motion of domains in a harmonic potential is the appropriate model to examine functional hinge motions dependent on the structural topology and highlights the role of internal forces and friction to function. PMID:27020739

Scaling earthquake ground motions for performance-based assessment of buildings

USGS Publications Warehouse

Huang, Y.-N.; Whittaker, A.S.; Luco, N.; Hamburger, R.O.

2011-01-01

The impact of alternate ground-motion scaling procedures on the distribution of displacement responses in simplified structural systems is investigated. Recommendations are provided for selecting and scaling ground motions for performance-based assessment of buildings. Four scaling methods are studied, namely, (1)geometric-mean scaling of pairs of ground motions, (2)spectrum matching of ground motions, (3)first-mode-period scaling to a target spectral acceleration, and (4)scaling of ground motions per the distribution of spectral demands. Data were developed by nonlinear response-history analysis of a large family of nonlinear single degree-of-freedom (SDOF) oscillators that could represent fixed-base and base-isolated structures. The advantages and disadvantages of each scaling method are discussed. The relationship between spectral shape and a ground-motion randomness parameter, is presented. A scaling procedure that explicitly considers spectral shape is proposed. ?? 2011 American Society of Civil Engineers.

Fast antibody fragment motion: flexible linkers act as entropic spring

DOE PAGES

Stingaciu, Laura R.; Ivanova, Oxana; Ohl, Michael; ...

2016-03-29

A flexible linker region between three fragments allows antibodies to adjust their binding sites to an antigen or receptor. Using Neutron Spin Echo Spectroscopy we observed fragment motion on a timescale of 7 ns with motional amplitudes of about 1 nm relative to each other. The mechanistic complexity of the linker region can be described by a spring model with Brownian motion of the fragments in a harmonic potential. Displacements, timescale, friction and force constant of the underlying dynamics are accessed. The force constant exhibits a similar strength to an entropic spring, with friction of the fragment matching the unboundmore » state. The observed fast motions are fluctuations in pre-existing equilibrium configurations. In conclusion, the Brownian motion of domains in a harmonic potential is the appropriate model to examine functional hinge motions dependent on the structural topology and highlights the role of internal forces and friction to function.« less

Fast antibody fragment motion: flexible linkers act as entropic spring.

PubMed

Stingaciu, Laura R; Ivanova, Oxana; Ohl, Michael; Biehl, Ralf; Richter, Dieter

2016-03-29

A flexible linker region between three fragments allows antibodies to adjust their binding sites to an antigen or receptor. Using Neutron Spin Echo Spectroscopy we observed fragment motion on a timescale of 7 ns with motional amplitudes of about 1 nm relative to each other. The mechanistic complexity of the linker region can be described by a spring model with Brownian motion of the fragments in a harmonic potential. Displacements, timescale, friction and force constant of the underlying dynamics are accessed. The force constant exhibits a similar strength to an entropic spring, with friction of the fragment matching the unbound state. The observed fast motions are fluctuations in pre-existing equilibrium configurations. The Brownian motion of domains in a harmonic potential is the appropriate model to examine functional hinge motions dependent on the structural topology and highlights the role of internal forces and friction to function.

Moving Object Detection Using a Parallax Shift Vector Algorithm

NASA Astrophysics Data System (ADS)

Gural, Peter S.; Otto, Paul R.; Tedesco, Edward F.

2018-07-01

There are various algorithms currently in use to detect asteroids from ground-based observatories, but they are generally restricted to linear or mildly curved movement of the target object across the field of view. Space-based sensors in high inclination, low Earth orbits can induce significant parallax in a collected sequence of images, especially for objects at the typical distances of asteroids in the inner solar system. This results in a highly nonlinear motion pattern of the asteroid across the sensor, which requires a more sophisticated search pattern for detection processing. Both the classical pattern matching used in ground-based asteroid search and the more sensitive matched filtering and synthetic tracking techniques, can be adapted to account for highly complex parallax motion. A new shift vector generation methodology is discussed along with its impacts on commonly used detection algorithms, processing load, and responsiveness to asteroid track reporting. The matched filter, template generator, and pattern matcher source code for the software described herein are available via GitHub.

Matching visual and nonvisual signals: evidence for a mechanism to discount optic flow during locomotion

NASA Astrophysics Data System (ADS)

Thurrell, Adrian; Pelah, Adar

2005-03-01

We report on recent experiments to investigate the Arthrovisual Locomotor Effect (ALE), a mechanism based on non-visual signals postulated to discount or remove the self-generated visual motion signals during locomotion. It is shown that perceptual matches made by standing subjects to a constant motion optic flow stimulus that is viewed while walking on a treadmill are linearly reduced by walking speed, a measure of the reported ALE. The degree of reduction in perceived speed depends on the similarity of the motor activity to natural locomotion, thus for the four activities tested, ALE strength is ranked as follows: Walking > Cycling > Hand Pedalling > Finger Tapping = 0. Other variations and important controls for the ALE are described.

Performance of sand and shredded rubber tire mixture as a natural base isolator for earthquake protection

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Srijit; Sengupta, Aniruddha; Reddy, G. R.

2015-12-01

The performance of a well-designed layer of sand, and composites like layer of sand mixed with shredded rubber tire (RSM) as low cost base isolators, is studied in shake table tests in the laboratory. The building foundation is modeled by a 200 mm by 200 mm and 40 mm thick rigid plexi-glass block. The block is placed in the middle of a 1m by 1m tank filled with sand. The selected base isolator is placed between the block and the sand foundation. Accelerometers are placed on top of the footing and foundation sand layer. The displacement of the footing is also measured by LVDT. The whole setup is mounted on a shake table and subjected to sinusoidal motions with varying amplitude and frequency. Sand is found to be effective only at very high amplitude (> 0.65 g) of motions. The performance of a composite consisting of sand and 50% shredded rubber tire placed under the footing is found to be most promising as a low-cost effective base isolator.

The contribution of visual and proprioceptive information to the perception of leaning in a dynamic motorcycle simulator.

PubMed

Lobjois, Régis; Dagonneau, Virginie; Isableu, Brice

2016-11-01

Compared with driving or flight simulation, little is known about self-motion perception in riding simulation. The goal of this study was to examine whether or not continuous roll motion supports the sensation of leaning into bends in dynamic motorcycle simulation. To this end, riders were able to freely tune the visual scene and/or motorcycle simulator roll angle to find a pattern that matched their prior knowledge. Our results revealed idiosyncrasy in the combination of visual and proprioceptive information. Some subjects relied more on the visual dimension, but reported increased sickness symptoms with the visual roll angle. Others relied more on proprioceptive information, tuning the direction of the visual scenery to match three possible patterns. Our findings also showed that these two subgroups tuned the motorcycle simulator roll angle in a similar way. This suggests that sustained inertially specified roll motion have contributed to the sensation of leaning in spite of the occurrence of unexpected gravito-inertial stimulation during the tilt. Several hypotheses are discussed. Practitioner Summary: Self-motion perception in motorcycle simulation is a relatively new research area. We examined how participants combined visual and proprioceptive information. Findings revealed individual differences in the visual dimension. However, participants tuned the simulator roll angle similarly, supporting the hypothesis that sustained inertially specified roll motion contributes to a leaning sensation.

Physiological demands of women's rugby union: time-motion analysis and heart rate response.

PubMed

Virr, Jody Lynn; Game, Alex; Bell, Gordon John; Syrotuik, Daniel

2014-01-01

The aim of this study was to determine the physical demands of women's rugby union match play using time-motion analysis and heart rate (HR) response. Thirty-eight premier club level female rugby players, ages 18-34 years were videotaped and HRs monitored for a full match. Performances were coded into 12 different movement categories: 5 speeds of locomotion (standing, walking, jogging, striding, sprinting), 4 forms of intensive non-running exertion (ruck/maul/tackle, pack down, scrum, lift) and 3 discrete activities (kick, jump, open field tackle). The main results revealed that backs spend significantly more time sprinting and walking whereas forwards spend more time in intensive non-running exertion and jogging. Forwards also had a significantly higher total work frequency compared to the backs, but a higher total rest frequency compared to the backs. In terms of HR responses, forwards displayed higher mean HRs throughout the match and more time above 80% of their maximum HR than backs. In summary, women's rugby union is characterised by intermittent bursts of high-intensity activity, where forwards and backs have similar anaerobic energy demands, but different specific match demands.

Launch window analysis in a new perspective with examples of departures from Earth to Mars

NASA Technical Reports Server (NTRS)

Thibodeau, J. R., III; Bond, V. R.

1972-01-01

Earth-departure windows are investigated for two round trip stopover missions to Mars. These are the 1981 inbound Venus swingby mission and the 1986 direct minimum-energy mission. The secular effects of planetary oblateness are used to predict the motion of the parking orbit. A procedure is developed for matching the motion of the parking orbit and the escape asymptote. Earth-departure velocity penalties, caused by orbital plane misalinement, are reduced by synchronizing the motion of the parking orbit and the escape trajectory.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackrel, Sara L.; Owens, Sarah M.; Gilbert, Jack A.

Plants in terrestrial and aquatic environments contain a diverse microbiome. Yet, the chloroplast and mitochondria organelles of the plant eukaryotic cell originate from free-living cyanobacteria and Rickettsiales. This represents a challenge for sequencing the plant microbiome with universal primers, as ~99% of 16S rRNA sequences may consist of chloroplast and mitochondrial sequences. Peptide nucleic acid clamps offer a potential solution by blocking amplification of host-associated sequences. We assessed the efficacy of chloroplast and mitochondria-blocking clamps against a range of microbial taxa from soil, freshwater and marine environments. While we found that the mitochondrial blocking clamps appear to be a robustmore » method for assessing animal-associated microbiota, Proteobacterial 16S rRNA binds to the chloroplast-blocking clamp, resulting in a strong sequencing bias against this group. We attribute this bias to a conserved 14-bp sequence in the Proteobacteria that matches the 17-bp chloroplast-blocking clamp sequence. By scanning the Greengenes database, we provide a reference list of nearly 1500 taxa that contain this 14-bp sequence, including 48 families such as the Rhodobacteraceae, Phyllobacteriaceae, Rhizobiaceae, Kiloniellaceae and Caulobacteraceae. To determine where these taxa are found in nature, we mapped this taxa reference list against the Earth Microbiome Project database. These taxa are abundant in a variety of environments, particularly aquatic and semiaquatic freshwater and marine habitats. To facilitate informed decisions on effective use of organelle-blocking clamps, we provide a searchable database of microbial taxa in the Greengenes and Silva databases matching various n-mer oligonucleotides of each PNA sequence.« less

Interactive Block Games for Assessing Children's Cognitive Skills: Design and Preliminary Evaluation.

PubMed

Lee, Kiju; Jeong, Donghwa; Schindler, Rachael C; Hlavaty, Laura E; Gross, Susan I; Short, Elizabeth J

2018-01-01

Background: This paper presents design and results from preliminary evaluation of Tangible Geometric Games (TAG-Games) for cognitive assessment in young children. The TAG-Games technology employs a set of sensor-integrated cube blocks, called SIG-Blocks, and graphical user interfaces for test administration and real-time performance monitoring. TAG-Games were administered to children from 4 to 8 years of age for evaluating preliminary efficacy of this new technology-based approach. Methods: Five different sets of SIG-Blocks comprised of geometric shapes, segmented human faces, segmented animal faces, emoticons, and colors, were used for three types of TAG-Games, including Assembly, Shape Matching, and Sequence Memory. Computational task difficulty measures were defined for each game and used to generate items with varying difficulty. For preliminary evaluation, TAG-Games were tested on 40 children. To explore the clinical utility of the information assessed by TAG-Games, three subtests of the age-appropriate Wechsler tests (i.e., Block Design, Matrix Reasoning, and Picture Concept) were also administered. Results: Internal consistency of TAG-Games was evaluated by the split-half reliability test. Weak to moderate correlations between Assembly and Block Design, Shape Matching and Matrix Reasoning, and Sequence Memory and Picture Concept were found. The computational measure of task complexity for each TAG-Game showed a significant correlation with participants' performance. In addition, age-correlations on TAG-Game scores were found, implying its potential use for assessing children's cognitive skills autonomously.

Interactive Block Games for Assessing Children's Cognitive Skills: Design and Preliminary Evaluation

PubMed Central

Lee, Kiju; Jeong, Donghwa; Schindler, Rachael C.; Hlavaty, Laura E.; Gross, Susan I.; Short, Elizabeth J.

2018-01-01

Background: This paper presents design and results from preliminary evaluation of Tangible Geometric Games (TAG-Games) for cognitive assessment in young children. The TAG-Games technology employs a set of sensor-integrated cube blocks, called SIG-Blocks, and graphical user interfaces for test administration and real-time performance monitoring. TAG-Games were administered to children from 4 to 8 years of age for evaluating preliminary efficacy of this new technology-based approach. Methods: Five different sets of SIG-Blocks comprised of geometric shapes, segmented human faces, segmented animal faces, emoticons, and colors, were used for three types of TAG-Games, including Assembly, Shape Matching, and Sequence Memory. Computational task difficulty measures were defined for each game and used to generate items with varying difficulty. For preliminary evaluation, TAG-Games were tested on 40 children. To explore the clinical utility of the information assessed by TAG-Games, three subtests of the age-appropriate Wechsler tests (i.e., Block Design, Matrix Reasoning, and Picture Concept) were also administered. Results: Internal consistency of TAG-Games was evaluated by the split-half reliability test. Weak to moderate correlations between Assembly and Block Design, Shape Matching and Matrix Reasoning, and Sequence Memory and Picture Concept were found. The computational measure of task complexity for each TAG-Game showed a significant correlation with participants' performance. In addition, age-correlations on TAG-Game scores were found, implying its potential use for assessing children's cognitive skills autonomously. PMID:29868520

Torque exerted on the side of crustal blocks controls the kinematics of Ethiopian Rift

NASA Astrophysics Data System (ADS)

Muluneh, Ameha A.; Kidane, Tesfaye; Cuffaro, Marco; Doglioni, Carlo

2016-04-01

Plate tectonic stress at active plate boundary can arises from 1) a torque applied on the side of lithospheric blocks and 2) a torque at the base of the lithosphere due to the flow of the underlying mantle. In this paper we use a simple force balance analysis to compare side and basal shear stresses and their contribution in driving kinematics and deformation in the Ethiopian Rift (ER), in the northern part of the East African Rift System (EARS). Assuming the constraints of the ER given by the dimension of the lithospheric blocks, the strain rate, the viscosity of the low velocity zone (LVZ) and the depth of the brittle-ductile transition zone, the lateral torque is several orders of magnitude higher than the basal torque. The minor contribution of basal torque might be due to low viscosity in the LVZ. Both Africa and Somalia plates are moving to the ;west; relative to the mantle and there are not slabs that can justify this pull and consequent motion. Therefore, we invoke that westerly oriented tidal torque on Africa and Somalia plates in providing the necessary side torque in the region. This plate motion predicts significant sinistral transtension along the ER and rift parallel strike-slip faulting similar to the estimated angular velocity vector for tectonic blocks and GPS observations. Vertical axis block rotations are observed in areas where the lithospheric mantle is removed and strain is widely distributed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chi, Y; Rezaeian, N Hassan; Hannan, R

Purpose: Intra-fractional prostate motion leads uncertainty on delivered dose in radiotherapy and may cause significant dose deviation from the planned dose distribution. This is especially a concern in scenarios with a high dose per fraction and hence a long delivery time, e.g. stereotactic body radiotherapy. Knowledge about intra-fractional prostate motion is valuable to address this problem, e.g. by reconstructing delivered dose and performing adaptation. This study proposes a new approach to determine intra-fractional prostate motion in VMAT via 2D/3D maker registration. Methods: At our institution, each patient has three markers implanted in the prostate. During treatment delivery, kV triggered imagesmore » were taken every three seconds to acquire 2D projection of 3D anatomy at the direction orthogonal to the therapeutic beam. Projected marker locations were identified on each projection image using template matching with geometric constraints. 3D prostate translation and rotation for each triggered image were obtained by solving an optimization problem, such that the calculated marker locations match the measured ones. Inter-image motion smoothness was employed as a constraint. We tested this method in simulation studies with five realistic prostate motion trajectories acquired via Calypso and in real phantom experiments. Results: For the simulation case, the motion range for these patients was 0.5∼6.0 mm. Root mean square (RMS) error of calculated motion along left-right (LR), anterior-posterior (AP) and cranial-caudal (CC) directions were 0.26mm, 0.36mm, and 0.016mm, respectively. The motion range in the phantom study along LR, AP, and CC directions were 15mm, 20mm and 10mm. The mean RMS errors along these directions were 1.99mm, 1.37mm and 0.22mm. Conclusion: A new prostate motion tracking algorithm based on kV triggered images has been developed and validated. Clinically acceptable accuracy has been achieved.« less

Testing long-period ground-motion simulations of scenario earthquakes using the Mw 7.2 El Mayor-Cucapah mainshock: Evaluation of finite-fault rupture characterization and 3D seismic velocity models

USGS Publications Warehouse

Graves, Robert W.; Aagaard, Brad T.

2011-01-01

Using a suite of five hypothetical finite-fault rupture models, we test the ability of long-period (T>2.0 s) ground-motion simulations of scenario earthquakes to produce waveforms throughout southern California consistent with those recorded during the 4 April 2010 Mw 7.2 El Mayor-Cucapah earthquake. The hypothetical ruptures are generated using the methodology proposed by Graves and Pitarka (2010) and require, as inputs, only a general description of the fault location and geometry, event magnitude, and hypocenter, as would be done for a scenario event. For each rupture model, two Southern California Earthquake Center three-dimensional community seismic velocity models (CVM-4m and CVM-H62) are used, resulting in a total of 10 ground-motion simulations, which we compare with recorded ground motions. While the details of the motions vary across the simulations, the median levels match the observed peak ground velocities reasonably well, with the standard deviation of the residuals generally within 50% of the median. Simulations with the CVM-4m model yield somewhat lower variance than those with the CVM-H62 model. Both models tend to overpredict motions in the San Diego region and underpredict motions in the Mojave desert. Within the greater Los Angeles basin, the CVM-4m model generally matches the level of observed motions, whereas the CVM-H62 model tends to overpredict the motions, particularly in the southern portion of the basin. The variance in the peak velocity residuals is lowest for a rupture that has significant shallow slip (<5 km depth), whereas the variance in the residuals is greatest for ruptures with large asperities below 10 km depth. Overall, these results are encouraging and provide confidence in the predictive capabilities of the simulation methodology, while also suggesting some regions in which the seismic velocity models may need improvement.

Temporal regularization of ultrasound-based liver motion estimation for image-guided radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

O’Shea, Tuathan P., E-mail: tuathan.oshea@icr.ac.uk; Bamber, Jeffrey C.; Harris, Emma J.

Purpose: Ultrasound-based motion estimation is an expanding subfield of image-guided radiation therapy. Although ultrasound can detect tissue motion that is a fraction of a millimeter, its accuracy is variable. For controlling linear accelerator tracking and gating, ultrasound motion estimates must remain highly accurate throughout the imaging sequence. This study presents a temporal regularization method for correlation-based template matching which aims to improve the accuracy of motion estimates. Methods: Liver ultrasound sequences (15–23 Hz imaging rate, 2.5–5.5 min length) from ten healthy volunteers under free breathing were used. Anatomical features (blood vessels) in each sequence were manually annotated for comparison withmore » normalized cross-correlation based template matching. Five sequences from a Siemens Acuson™ scanner were used for algorithm development (training set). Results from incremental tracking (IT) were compared with a temporal regularization method, which included a highly specific similarity metric and state observer, known as the α–β filter/similarity threshold (ABST). A further five sequences from an Elekta Clarity™ system were used for validation, without alteration of the tracking algorithm (validation set). Results: Overall, the ABST method produced marked improvements in vessel tracking accuracy. For the training set, the mean and 95th percentile (95%) errors (defined as the difference from manual annotations) were 1.6 and 1.4 mm, respectively (compared to 6.2 and 9.1 mm, respectively, for IT). For each sequence, the use of the state observer leads to improvement in the 95% error. For the validation set, the mean and 95% errors for the ABST method were 0.8 and 1.5 mm, respectively. Conclusions: Ultrasound-based motion estimation has potential to monitor liver translation over long time periods with high accuracy. Nonrigid motion (strain) and the quality of the ultrasound data are likely to have an impact on tracking performance. A future study will investigate spatial uniformity of motion and its effect on the motion estimation errors.« less

Architecture design of motion estimation for ITU-T H.263

NASA Astrophysics Data System (ADS)

Ku, Chung-Wei; Lin, Gong-Sheng; Chen, Liang-Gee; Lee, Yung-Ping

1997-01-01

Digitalized video and audio system has become the trend of the progress in multimedia, because it provides great performance in quality and feasibility of processing. However, as the huge amount of information is needed while the bandwidth is limitted, data compression plays an important role in the system. Say, for a 176 x 144 monochromic sequence with 10 frames/sec frame rate, the bandwidth is about 2Mbps. This wastes much channel resource and limits the applications. MPEG (moving picttre ezpert groip) standardizes the video codec scheme, and it performs high compression ratio while providing good quality. MPEG-i is used for the frame size about 352 x 240 and 30 frames per second, and MPEG-2 provides scalibility and can be applied on scenes with higher definition, say HDTV (high definition television). On the other hand, some applications concerns the very low bit-rate, such as videophone and video-conferencing. Because the channel bandwidth is much limitted in telephone network, a very high compression ratio must be required. ITU-T announced the H.263 video coding standards to meet the above requirements.8 According to the simulation results of TMN-5,22 it outperforms 11.263 with little overhead of complexity. Since wireless communication is the trend in the near future, low power design of the video codec is an important issue for portable visual telephone. Motion estimation is the most computation consuming parts in the whole video codec. About 60% of the computation is spent on this parts for the encoder. Several architectures were proposed for efficient processing of block matching algorithms. In this paper, in order to meet the requirements of 11.263 and the expectation of low power consumption, a modified sandwich architecture in21 is proposed. Based on the parallel processing philosophy, low power is expected and the generation of either one motion vector or four motion vectors with half-pixel accuracy is achieved concurrently. In addition, we will present our solution how to solve the other addition modes in 11.263 with the proposed architecture.

Efficient structure from motion for oblique UAV images based on maximal spanning tree expansion

NASA Astrophysics Data System (ADS)

Jiang, San; Jiang, Wanshou

2017-10-01

The primary contribution of this paper is an efficient Structure from Motion (SfM) solution for oblique unmanned aerial vehicle (UAV) images. First, an algorithm, considering spatial relationship constraints between image footprints, is designed for match pair selection with the assistance of UAV flight control data and oblique camera mounting angles. Second, a topological connection network (TCN), represented by an undirected weighted graph, is constructed from initial match pairs, which encodes the overlap areas and intersection angles into edge weights. Then, an algorithm, termed MST-Expansion, is proposed to extract the match graph from the TCN, where the TCN is first simplified by a maximum spanning tree (MST). By further analysis of the local structure in the MST, expansion operations are performed on the vertices of the MST for match graph enhancement, which is achieved by introducing critical connections in the expansion directions. Finally, guided by the match graph, an efficient SfM is proposed. Under extensive analysis and comparison, its performance is verified by using three oblique UAV datasets captured with different multi-camera systems. Experimental results demonstrate that the efficiency of image matching is improved, with speedup ratios ranging from 19 to 35, and competitive orientation accuracy is achieved from both relative bundle adjustment (BA) without GCPs (Ground Control Points) and absolute BA with GCPs. At the same time, images in the three datasets are successfully oriented. For the orientation of oblique UAV images, the proposed method can be a more efficient solution.

Translation and rotation of small crustal blocks in the southernmost Atlantic-Weddell Sea region prior to seafloor spreading: in search of a mechanism

NASA Astrophysics Data System (ADS)

Dalziel, I. W. D.; Norton, I. O.; Lawver, L. A.; Lavier, L.; Davis, J. K.; Gahagan, L.

2016-12-01

Geological and paleomagnetic data indicate that initial fragmentation of the Gondwanaland supercontinent in the southernmost Atlantic-Weddell Sea region involved translation and rotation of two small crustal blocks. The Falkland/Malvinas block on the South American plate (F/M) and the Ellsworth-Whitmore mountains block in West Antarctica (EWM) both contain segments of the earliest Mesozoic Gondwana fold belt. The blocks originated in the Natal embayment between the Cape Mountains of southernmost Africa and the Pensacola Mountains of the East Antarctic craton margin. Shortly after emplacement of the Karoo-Ferrar large igneous province (LIP) at ca. 182Ma, the F/M block was rotated clockwise 150 ° and the EWM block counter¬clockwise 90°, while both were translated several hundred kilometers towards the Panthalassic/Pacific Ocean. As indicated by absence of shortening in the sedimentary basins of the F/M Plateau and Weddell embayment, the motions of the crustal blocks relative to the major continents happened during extreme extension accompanied by widespread silicic magmatism that preceded seafloor spreading. We propose a new reconstruction of the Gondwana craton margin, suggesting an original embayment between the Kalahari and East Antarctic cratons, and subsequent mirror-image clockwise (South America-F/M) and counterclockwise (Antarctic Peninsula-EWM) rotations prior to seafloor spreading in the Weddell Sea and South Atlantic.What geodynamic processes were involved in the significant rotations and translations of continental lithosphere prior to ocean basin formation? Our conclusion, based on the geologic and geophysical data and on geodynamic modeling, is that the motions were driven by the distributed crustal thinning of warm continental lithosphere and by mantle flow towards a retreating Panthalassic margin subduction zone associated with the formation of the Karoo-Ferrar Large Igneous Province between the East Antarctic, Kalahari and Rio de la Plata cratons.

Block design reconstruction skills: not a good candidate for an endophenotypic marker in autism research.

PubMed

de Jonge, Maretha; Kemner, Chantal; Naber, Fabienne; van Engeland, Herman

2009-04-01

Superior performance on block design tasks is reported in autistic individuals, although it is not consistently found in high-functioning individuals or individuals with Asperger Syndrome. It is assumed to reflect weak central coherence: an underlying cognitive deficit, which might also be part of the genetic makeup of the disorder. We assessed block design reconstruction skills in high-functioning individuals with autism spectrum disorders (ASD) from multi-incidence families and in their parents. Performance was compared to relevant matched control groups. We used a task that was assumed to be highly sensitive to subtle performance differences. We did not find individuals with ASD to be significantly faster on this task than the matched control group, not even when the difference between reconstruction time of segmented and pre-segmented designs was compared. However, we found individuals with ASD to make fewer errors during the process of reconstruction which might indicate some dexterity in mental segmentation. However, parents of individuals with ASD did not perform better on the task than control parents. Therefore, based on our data, we conclude that mental segmentation ability as measured with a block design reconstruction task is not a neurocognitive marker or endophenotype useful in genetic studies.

Motion of David Glacier in East Antarctica Observed by COSMO-SkyMed Differential SAR Interferometry

NASA Astrophysics Data System (ADS)

Han, H.; Lee, H.

2011-12-01

David glacier, located in Victoria Land, East Antarctica (75°20'S, 161°15'E), is an outlet glacier of 13 km width near the grounding line and 50 km long from the source to the grounding line. David glacier flows into Ross Sea forming Drygalski Ice Tongue, 100 km long and 23 km wide. In this study, we extracted a surface displacement map of David by applying differential SAR interferometry (DInSAR) to one-day tandem pairs obtained from COSMO-SkyMed satellites on April 28-29 (descending orbit) and May 5-6 (ascending orbit), 2011, respectively. Terra ASTER global digital elevation model (GDEM) is used to remove the topographic effect from the COSMO-SkyMed interferograms. David glacier showed maximum displacement of 35 cm during April 28-29 and 20 cm during May 5-6 in the direction of radar line of sight. The glacier can be divided into several blocks by the disparities of displacement between the different sliding zone. Surface displacement map contains errors originated from orbit data, atmospheric conditions, DEM error. GDEM is generated from the ASTER optical images acquired from 2000 to 2008. It has the vertical accuracy of about 20 m at 95% confidence with the 30 m of horizontal posting. The accuracy of GDEM reduces when cloud cover is included in the ASTER image. Particularly in the snow and ice area, GDEM is inaccurate due to whiteout effect during stereo matching. The inaccuracy of GDEM could be a reason of the observed glacier motion in the opposite direction of gravity. This problem can be solved by using TanDEM-X DEM. Bistatic acquisition of SAR images from the constellation of TerraSAR-X and TanDEM-X will generate a global DEM with the vertical accuracy better than 2 m and the horizontal posting of 12 m. We plan to perform DInSAR of COSMO-SkyMed one-day tandem pairs again when the high-accuracy TanDEM-X DEM is available in the near future. As a conclusion, we could analyze the displacement of David glacier in East Antarctica. The glacier showed very fast motion forming a block of streamlines with different flow velocity. For more accurate analysis, we will use TanDEM-X DEM to perform the DInSAR. The flow characteristics, ice mass balance, ice discharge rate of David glacier remains as an ongoing research.

MIMO channel estimation and evaluation for airborne traffic surveillance in cellular networks

NASA Astrophysics Data System (ADS)

Vahidi, Vahid; Saberinia, Ebrahim

2018-01-01

A channel estimation (CE) procedure based on compressed sensing is proposed to estimate the multiple-input multiple-output sparse channel for traffic data transmission from drones to ground stations. The proposed procedure consists of an offline phase and a real-time phase. In the offline phase, a pilot arrangement method, which considers the interblock and block mutual coherence simultaneously, is proposed. The real-time phase contains three steps. At the first step, it obtains the priori estimate of the channel by block orthogonal matching pursuit; afterward, it utilizes that estimated channel to calculate the linear minimum mean square error of the received pilots. Finally, the block compressive sampling matching pursuit utilizes the enhanced received pilots to estimate the channel more accurately. The performance of the CE procedure is evaluated by simulating the transmission of traffic data through the communication channel and evaluating its fidelity for car detection after demodulation. Simulation results indicate that the proposed CE technique enhances the performance of the car detection in a traffic image considerably.

Modelling of the Human Knee Joint Supported by Active Orthosis

NASA Astrophysics Data System (ADS)

Musalimov, V.; Monahov, Y.; Tamre, M.; Rõbak, D.; Sivitski, A.; Aryassov, G.; Penkov, I.

2018-02-01

The article discusses motion of a healthy knee joint in the sagittal plane and motion of an injured knee joint supported by an active orthosis. A kinematic scheme of a mechanism for the simulation of a knee joint motion is developed and motion of healthy and injured knee joints are modelled in Matlab. Angles between links, which simulate the femur and tibia are controlled by Simulink block of Model predictive control (MPC). The results of simulation have been compared with several samples of real motion of the human knee joint obtained from motion capture systems. On the basis of these analyses and also of the analysis of the forces in human lower limbs created at motion, an active smart orthosis is developed. The orthosis design was optimized to achieve an energy saving system with sufficient anatomy, necessary reliability, easy exploitation and low cost. With the orthosis it is possible to unload the knee joint, and also partially or fully compensate muscle forces required for the bending of the lower limb.

Motion Cueing Algorithm Development: New Motion Cueing Program Implementation and Tuning

NASA Technical Reports Server (NTRS)

Houck, Jacob A. (Technical Monitor); Telban, Robert J.; Cardullo, Frank M.; Kelly, Lon C.

2005-01-01

A computer program has been developed for the purpose of driving the NASA Langley Research Center Visual Motion Simulator (VMS). This program includes two new motion cueing algorithms, the optimal algorithm and the nonlinear algorithm. A general description of the program is given along with a description and flowcharts for each cueing algorithm, and also descriptions and flowcharts for subroutines used with the algorithms. Common block variable listings and a program listing are also provided. The new cueing algorithms have a nonlinear gain algorithm implemented that scales each aircraft degree-of-freedom input with a third-order polynomial. A description of the nonlinear gain algorithm is given along with past tuning experience and procedures for tuning the gain coefficient sets for each degree-of-freedom to produce the desired piloted performance. This algorithm tuning will be needed when the nonlinear motion cueing algorithm is implemented on a new motion system in the Cockpit Motion Facility (CMF) at the NASA Langley Research Center.

The determination of high-resolution spatio-temporal glacier motion fields from time-lapse sequences

NASA Astrophysics Data System (ADS)

Schwalbe, Ellen; Maas, Hans-Gerd

2017-12-01

This paper presents a comprehensive method for the determination of glacier surface motion vector fields at high spatial and temporal resolution. These vector fields can be derived from monocular terrestrial camera image sequences and are a valuable data source for glaciological analysis of the motion behaviour of glaciers. The measurement concepts for the acquisition of image sequences are presented, and an automated monoscopic image sequence processing chain is developed. Motion vector fields can be derived with high precision by applying automatic subpixel-accuracy image matching techniques on grey value patterns in the image sequences. Well-established matching techniques have been adapted to the special characteristics of the glacier data in order to achieve high reliability in automatic image sequence processing, including the handling of moving shadows as well as motion effects induced by small instabilities in the camera set-up. Suitable geo-referencing techniques were developed to transform image measurements into a reference coordinate system.The result of monoscopic image sequence analysis is a dense raster of glacier surface point trajectories for each image sequence. Each translation vector component in these trajectories can be determined with an accuracy of a few centimetres for points at a distance of several kilometres from the camera. Extensive practical validation experiments have shown that motion vector and trajectory fields derived from monocular image sequences can be used for the determination of high-resolution velocity fields of glaciers, including the analysis of tidal effects on glacier movement, the investigation of a glacier's motion behaviour during calving events, the determination of the position and migration of the grounding line and the detection of subglacial channels during glacier lake outburst floods.

Tectonics and Relative Plate Motions Around the Andaman Sea and Sumatra

NASA Astrophysics Data System (ADS)

Eguchi, T.; Murakoshi, T.

2005-12-01

There are several R-F-R models of the active back-arc opening system in the Andaman Sea proposed by authors, e.g., Curray et al. (1978), Eguchi et al. (1979), Eguchi (1991), Mantovani et al. (2001) and Nielsen et al. (2004). Most of the previous authors, except Eguchi et al. (1978) and Eguchi (1991), documented NW-SE or NNW-SSE striking relative plate motion at the Central Andaman Rift. Recent multi-beam bathymetry study by GEODYSSEA Project group confirmed the detailed configuration of the ENE-WSW striking Central Andaman Rift and adjacent transcurrent faults. All of data from the marine survey and recent shallow earthquakes as well as their strike-slip type focal mechanisms along the N-S striking fault segment at 95.2E from 11N to 12.5N support the approximate N-S opening at the adjacent Central Andaman Rift. The magnetic anomaly survey data of Curray et al. (1978) suggest that, in the case of N-S opening, the rate becomes 4.0 cm/y, although Curray et al. (1978) proposed the total rate of 3.7 cm/y in the case of NNW-SSE opening. We then studied the realistic geometry of plate boundaries from Sumatra through the Andaman sea including the Central Andaman Rift to Myanmar, using recent seismological data and GPS studies. As is important, the Sundaland is not part of the Eurasia plate as revealed by recent GPS surveys. Furthermore, based on data of GPS velocity vectors w.r.t. Eurasia plate (e.g., Pradirodirdjo et al., 1997; Michel et. al., 2001), we can recognize some differential motion within the NW-SE striking fore-arc block, which is bounded by the Sumatra transcurrent fault and Java trench. The GPS data indicate 'differential motion' in both the trench-parallel and trench-normal directions within the NW-SE striking fore-arc block. We must resolve whether such kind differential movement within the fore-arc block is steady or not, to investigate the detailed spatio-temporal nature of dynamic coupling at the subduction zones with intermittent activity of larger interplate seismic events. We have constrained 'plate motion polygons' at selected points by modifying the result of Eguchi (1991). For example, by assuming the NUVEL 1 model and introducing the shear faulting with the averaged rate of 2.6 cm/y along the Sumatra fault system, we obtained the ENE-WSW plate convergence with the rate of 1.2 cm/y at 12N and the convergence of 3.0 +- 0.3 cm/y at 5N, between the Indo-Australia plate and the fore-arc block at the western Java trench subduction zone. We, however, cannot constrain the instantaneous rotation vectors of the relative plate motions, mainly because of limited observation data.

Dynamics of a magnetic skyrmionium driven by spin waves

NASA Astrophysics Data System (ADS)

Li, Sai; Xia, Jing; Zhang, Xichao; Ezawa, Motohiko; Kang, Wang; Liu, Xiaoxi; Zhou, Yan; Zhao, Weisheng

2018-04-01

A magnetic skyrmionium is a skyrmion-like structure, but carries a zero net skyrmion number which can be used as a building block for non-volatile information processing devices. Here, we study the dynamics of a magnetic skyrmionium driven by propagating spin waves. It is found that the skyrmionium can be effectively driven into motion by spin waves showing a tiny skyrmion Hall effect, whose mobility is much better than that of the skyrmion at the same condition. We also show that the skyrmionium mobility depends on the nanotrack width and the damping coefficient and can be controlled by an external out-of-plane magnetic field. In addition, we demonstrate that the skyrmionium motion driven by spin waves is inertial. Our results indicate that the skyrmionium is a promising building block for building spin-wave spintronic devices.

Slip distribution and tectonic implication of the 1999 Chi-Chi, Taiwan, earthquake

USGS Publications Warehouse

Ji, C.; Helmberger, D.V.; Song, T.-R.A.; Ma, K.-F.; Wald, D.J.

2001-01-01

We report on the fault complexity of the large (Mw = 7.6) Chi-Chi earthquake obtained by inverting densely and well-distributed static measurements consisting of 119 GPS and 23 doubly integrated strong motion records. We show that the slip of the Chi-Chi earthquake was concentrated on the surface of a "wedge shaped" block. The inferred geometric complexity explains the difference between the strike of the fault plane determined by long period seismic data and surface break observations. When combined with other geophysical and geological observations, the result provides a unique snapshot of tectonic deformation taking place in the form of very large (>10m) displacements of a massive wedge-shaped crustal block which may relate to the changeover from over-thrusting to subducting motion between the Philippine Sea and the Eurasian plates.

Direction detection thresholds of passive self-motion in artistic gymnasts.

PubMed

Hartmann, Matthias; Haller, Katia; Moser, Ivan; Hossner, Ernst-Joachim; Mast, Fred W

2014-04-01

In this study, we compared direction detection thresholds of passive self-motion in the dark between artistic gymnasts and controls. Twenty-four professional female artistic gymnasts (ranging from 7 to 20 years) and age-matched controls were seated on a motion platform and asked to discriminate the direction of angular (yaw, pitch, roll) and linear (leftward-rightward) motion. Gymnasts showed lower thresholds for the linear leftward-rightward motion. Interestingly, there was no difference for the angular motions. These results show that the outstanding self-motion abilities in artistic gymnasts are not related to an overall higher sensitivity in self-motion perception. With respect to vestibular processing, our results suggest that gymnastic expertise is exclusively linked to superior interpretation of otolith signals when no change in canal signals is present. In addition, thresholds were overall lower for the older (14-20 years) than for the younger (7-13 years) participants, indicating the maturation of vestibular sensitivity from childhood to adolescence.

Phi-s correlation and dynamic time warping - Two methods for tracking ice floes in SAR images

NASA Technical Reports Server (NTRS)

Mcconnell, Ross; Kober, Wolfgang; Kwok, Ronald; Curlander, John C.; Pang, Shirley S.

1991-01-01

The authors present two algorithms for performing shape matching on ice floe boundaries in SAR (synthetic aperture radar) images. These algorithms quickly produce a set of ice motion and rotation vectors that can be used to guide a pixel value correlator. The algorithms match a shape descriptor known as the Phi-s curve. The first algorithm uses normalized correlation to match the Phi-s curves, while the second uses dynamic programming to compute an elastic match that better accommodates ice floe deformation. Some empirical data on the performance of the algorithms on Seasat SAR images are presented.

Canal–Otolith Interactions and Detection Thresholds of Linear and Angular Components During Curved-Path Self-Motion

PubMed Central

MacNeilage, Paul R.; Turner, Amanda H.

2010-01-01

Gravitational signals arising from the otolith organs and vertical plane rotational signals arising from the semicircular canals interact extensively for accurate estimation of tilt and inertial acceleration. Here we used a classical signal detection paradigm to examine perceptual interactions between otolith and horizontal semicircular canal signals during simultaneous rotation and translation on a curved path. In a rotation detection experiment, blindfolded subjects were asked to detect the presence of angular motion in blocks where half of the trials were pure nasooccipital translation and half were simultaneous translation and yaw rotation (curved-path motion). In separate, translation detection experiments, subjects were also asked to detect either the presence or the absence of nasooccipital linear motion in blocks, in which half of the trials were pure yaw rotation and half were curved path. Rotation thresholds increased slightly, but not significantly, with concurrent linear velocity magnitude. Yaw rotation detection threshold, averaged across all conditions, was 1.45 ± 0.81°/s (3.49 ± 1.95°/s2). Translation thresholds, on the other hand, increased significantly with increasing magnitude of concurrent angular velocity. Absolute nasooccipital translation detection threshold, averaged across all conditions, was 2.93 ± 2.10 cm/s (7.07 ± 5.05 cm/s2). These findings suggest that conscious perception might not have independent access to separate estimates of linear and angular movement parameters during curved-path motion. Estimates of linear (and perhaps angular) components might instead rely on integrated information from canals and otoliths. Such interaction may underlie previously reported perceptual errors during curved-path motion and may originate from mechanisms that are specialized for tilt-translation processing during vertical plane rotation. PMID:20554843

Visuospatial, visuoperceptual, and visuoconstructive abilities in congenital hypothyroidism.

PubMed

Simic, Nevena; Khan, Sarah; Rovet, Joanne

2013-11-01

Individuals with congenital hypothyroidism (CH), even those diagnosed and treated early, experience selective cognitive deficits, the most striking of which involves the visuocognitive domain. However, the range and nature of their visuocognitive disturbances is not fully understood. We assessed a range of higher-order visuocognitive abilities in 19 children and adolescents with CH and 19 age- and sex-matched typically developing peers (TD) using a battery of neuropsychological tests and a novel self-report measure of sense of direction. CH scored lower than TD on direct tests of visuocognitive function (judging line orientation, parts-to-whole localization, copying three-dimensional block towers, discriminating designs, and matching unfamiliar faces in ¾ profile-view) as well as on self-reported problems in spatial ability. Visuocognitive problems were not global as CH and TD did not differ at copying two-dimensional block designs, mentally rotating and matching abstract shapes, or at matching unfamiliar front-view faces, design features, or designs that engaged either figure-ground segregation, visual constancy, or closure. Early and concurrent thyroid stimulating hormone (TSH) levels were associated with visuocognitive ability, although attention and working memory were not. Individuals with CH exhibit selective visuocognitive weaknesses, some of which are related to early and concurrent TSH levels.

Block Adjustment and Image Matching of WORLDVIEW-3 Stereo Pairs and Accuracy Evaluation

NASA Astrophysics Data System (ADS)

Zuo, C.; Xiao, X.; Hou, Q.; Li, B.

2018-05-01

WorldView-3, as a high-resolution commercial earth observation satellite, which is launched by Digital Global, provides panchromatic imagery of 0.31 m resolution. The positioning accuracy is less than 3.5 meter CE90 without ground control, which can use for large scale topographic mapping. This paper presented the block adjustment for WorldView-3 based on RPC model and achieved the accuracy of 1 : 2000 scale topographic mapping with few control points. On the base of stereo orientation result, this paper applied two kinds of image matching algorithm for DSM extraction: LQM and SGM. Finally, this paper compared the accuracy of the point cloud generated by the two image matching methods with the reference data which was acquired by an airborne laser scanner. The results showed that the RPC adjustment model of WorldView-3 image with small number of GCPs could satisfy the requirement of Chinese Surveying and Mapping regulations for 1 : 2000 scale topographic maps. And the point cloud result obtained through WorldView-3 stereo image matching had higher elevation accuracy, the RMS error of elevation for bare ground area is 0.45 m, while for buildings the accuracy can almost reach 1 meter.

Optimization of incremental structure from motion combining a random k-d forest and pHash for unordered images in a complex scene

NASA Astrophysics Data System (ADS)

Zhan, Zongqian; Wang, Chendong; Wang, Xin; Liu, Yi

2018-01-01

On the basis of today's popular virtual reality and scientific visualization, three-dimensional (3-D) reconstruction is widely used in disaster relief, virtual shopping, reconstruction of cultural relics, etc. In the traditional incremental structure from motion (incremental SFM) method, the time cost of the matching is one of the main factors restricting the popularization of this method. To make the whole matching process more efficient, we propose a preprocessing method before the matching process: (1) we first construct a random k-d forest with the large-scale scale-invariant feature transform features in the images and combine this with the pHash method to obtain a value of relatedness, (2) we then construct a connected weighted graph based on the relatedness value, and (3) we finally obtain a planned sequence of adding images according to the principle of the minimum spanning tree. On this basis, we attempt to thin the minimum spanning tree to reduce the number of matchings and ensure that the images are well distributed. The experimental results show a great reduction in the number of matchings with enough object points, with only a small influence on the inner stability, which proves that this method can quickly and reliably improve the efficiency of the SFM method with unordered multiview images in complex scenes.

Assessing breathing motion by shape matching of lung and diaphragm surfaces

NASA Astrophysics Data System (ADS)

Urschler, Martin; Bischof, Horst

2005-04-01

Studying complex thorax breating motion is an important research topic for accurate fusion of functional and anatomical data, radiotherapy planning or reduction of breathing motion artifacts. We investigate segmented CT lung, airway and diaphragm surfaces at several different breathing states between Functional Residual and Total Lung Capacity. In general, it is hard to robustly derive corresponding shape features like curvature maxima from lung and diaphragm surfaces since diaphragm and rib cage muscles tend to deform the elastic lung tissue such that e.g. ridges might disappear. A novel registration method based on the shape context approach for shape matching is presented where we extend shape context to 3D surfaces. The shape context approach was reported as a promising method for matching 2D shapes without relying on extracted shape features. We use the point correspondences for a non-rigid thin-plate-spline registration to get deformation fields that describe the movement of lung and diaphragm. Our validation consists of experiments on phantom and real sheep thorax data sets. Phantom experiments make use of shapes that are manipulated with known transformations that simulate breathing behaviour. Real thorax data experiments use a data set showing lungs and diaphragm at 5 distinct breathing states, where we compare subsets of the data sets and qualitatively and quantitatively asses the registration performance by using manually identified corresponding landmarks.

Emittance preservation in plasma-based accelerators with ion motion

DOE PAGES

Benedetti, C.; Schroeder, C. B.; Esarey, E.; ...

2017-11-01

In a plasma-accelerator-based linear collider, the density of matched, low-emittance, high-energy particle bunches required for collider applications can be orders of magnitude above the background ion density, leading to ion motion, perturbation of the focusing fields, and, hence, to beam emittance growth. By analyzing the response of the background ions to an ultrahigh density beam, analytical expressions, valid for nonrelativistic ion motion, are derived for the transverse wakefield and for the final (i.e., after saturation) bunch emittance. Analytical results are validated against numerical modeling. Initial beam distributions are derived that are equilibrium solutions, which require head-to-tail bunch shaping, enabling emittancemore » preservation with ion motion.« less

A prospective double blinded randomized study of anterior cruciate ligament reconstruction with hamstrings tendon and spinal anesthesia with or without femoral nerve block.

PubMed

Astur, Diego Costa; Aleluia, Vinicius; Veronese, Ciro; Astur, Nelson; Oliveira, Saulo Gomes; Arliani, Gustavo Gonçalves; Badra, Ricardo; Kaleka, Camila Cohen; Amaro, Joicemar Tarouco; Cohen, Moisés

2014-10-01

Current literature supports the thought that anesthesia and analgesia administered perioperatively for an anterior cruciate ligament (ACL) reconstruction have a great influence on time to effective rehabilitation during the first week after hospital discharge. The aim of this study is to answer the research question is there a difference in clinical outcomes between the use of a femoral nerve block with spinal anesthesia versus spinal analgesia alone for people undergoing ACL reconstruction? ACL reconstruction with spinal anesthesia and patient sedation (Group one); and spinal anesthesia with patient sedation and an additional femoral nerve block (Group two). Patients were re-evaluated for pain, range of motion (ROM), active contraction of the quadriceps, and a Functional Independence Measure (FIM) scoring scale. Spinal anesthesia with a femoral nerve block demonstrates pain relief 6h after surgery (VAS 0.37; p=0.007). From the third (VAS=4.56; p=0.028) to the seventh (VAS=2.87; p=0.05) days after surgery, this same nerve blockage delivered higher pain scores. Patients had a similar progressive improvement on knee joint range of motion with or without femoral nerve block (p<0.002). Group one and two had 23.75 and 24.29° 6h after surgery and 87.81 and 85.36° of knee flexion after 48h post op. Spinal anesthesia associated with a femoral nerve block had no additional benefits on pain control after the third postoperative day. There were no differences between groups concerning ability for knee flexion and to complete daily activities during postoperative period. Randomized Clinical Trial Level I. Copyright © 2014 Elsevier B.V. All rights reserved.

Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

ERIC Educational Resources Information Center

Vescovi, Jason D.

2016-01-01

Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,…

SU-E-J-108: Template Matching Based On Multiple Templates Can Improve the Tumor Tracking Performance When There Is Large Tumor Deformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, X; Lin, J; Diwanji, T

2014-06-01

Purpose: Recently, template matching has been shown to be able to track tumor motion on cine-MRI images. However, artifacts such as deformation, rotation, and/or out-of-plane movement could seriously degrade the performance of this technique. In this work, we demonstrate the utility of multiple templates derived from different phases of tumor motion in reducing the negative effects of artifacts and improving the accuracy of template matching methods. Methods: Data from 2 patients with large tumors and significant tumor deformation were analyzed from a group of 12 patients from an earlier study. Cine-MRI (200 frames) imaging was performed while the patients weremore » instructed to breathe normally. Ground truth tumor position was established on each frame manually by a radiation oncologist. Tumor positions were also automatically determined using template matching with either single or multiple (5) templates. The tracking errors, defined as the absolute differences in tumor positions determined by the manual and automated methods, when using either single or multiple templates were compared in both the AP and SI directions, respectively. Results: Using multiple templates reduced the tracking error of template matching. In the SI direction where the tumor movement and deformation were significant, the mean tracking error decreased from 1.94 mm to 0.91 mm (Patient 1) and from 6.61 mm to 2.06 mm (Patient 2). In the AP direction where the tumor movement was small, the reduction of the mean tracking error was significant in Patient 1 (from 3.36 mm to 1.04 mm), but not in Patient 2 ( from 3.86 mm to 3.80 mm). Conclusion: This study shows the effectiveness of using multiple templates in improving the performance of template matching when artifacts like large tumor deformation or out-of-plane motion exists. Accurate tumor tracking capabilities can be integrated with MRI guided radiation therapy systems. This work was supported in part by grants from NIH/NCI CA 124766 and Varian Medical Systems, Palo Alto, CA.« less

Human Actions Analysis: Templates Generation, Matching and Visualization Applied to Motion Capture of Highly-Skilled Karate Athletes

PubMed Central

Piekarczyk, Marcin; Ogiela, Marek R.

2017-01-01

The aim of this paper is to propose and evaluate the novel method of template generation, matching, comparing and visualization applied to motion capture (kinematic) analysis. To evaluate our approach, we have used motion capture recordings (MoCap) of two highly-skilled black belt karate athletes consisting of 560 recordings of various karate techniques acquired with wearable sensors. We have evaluated the quality of generated templates; we have validated the matching algorithm that calculates similarities and differences between various MoCap data; and we have examined visualizations of important differences and similarities between MoCap data. We have concluded that our algorithms works the best when we are dealing with relatively short (2–4 s) actions that might be averaged and aligned with the dynamic time warping framework. In practice, the methodology is designed to optimize the performance of some full body techniques performed in various sport disciplines, for example combat sports and martial arts. We can also use this approach to generate templates or to compare the correct performance of techniques between various top sportsmen in order to generate a knowledge base of reference MoCap videos. The motion template generated by our method can be used for action recognition purposes. We have used the DTW classifier with angle-based features to classify various karate kicks. We have performed leave-one-out action recognition for the Shorin-ryu and Oyama karate master separately. In this case, 100% actions were correctly classified. In another experiment, we used templates generated from Oyama master recordings to classify Shorin-ryu master recordings and vice versa. In this experiment, the overall recognition rate was 94.2%, which is a very good result for this type of complex action. PMID:29125560

Clinical Study of Orthogonal-View Phase-Matched Digital Tomosynthesis for Lung Tumor Localization.

PubMed

Zhang, You; Ren, Lei; Vergalasova, Irina; Yin, Fang-Fang

2017-01-01

Compared to cone-beam computed tomography, digital tomosynthesis imaging has the benefits of shorter scanning time, less imaging dose, and better mechanical clearance for tumor localization in radiation therapy. However, for lung tumors, the localization accuracy of the conventional digital tomosynthesis technique is affected by the lack of depth information and the existence of lung tumor motion. This study investigates the clinical feasibility of using an orthogonal-view phase-matched digital tomosynthesis technique to improve the accuracy of lung tumor localization. The proposed orthogonal-view phase-matched digital tomosynthesis technique benefits from 2 major features: (1) it acquires orthogonal-view projections to improve the depth information in reconstructed digital tomosynthesis images and (2) it applies respiratory phase-matching to incorporate patient motion information into the synthesized reference digital tomosynthesis sets, which helps to improve the localization accuracy of moving lung tumors. A retrospective study enrolling 14 patients was performed to evaluate the accuracy of the orthogonal-view phase-matched digital tomosynthesis technique. Phantom studies were also performed using an anthropomorphic phantom to investigate the feasibility of using intratreatment aggregated kV and beams' eye view cine MV projections for orthogonal-view phase-matched digital tomosynthesis imaging. The localization accuracy of the orthogonal-view phase-matched digital tomosynthesis technique was compared to that of the single-view digital tomosynthesis techniques and the digital tomosynthesis techniques without phase-matching. The orthogonal-view phase-matched digital tomosynthesis technique outperforms the other digital tomosynthesis techniques in tumor localization accuracy for both the patient study and the phantom study. For the patient study, the orthogonal-view phase-matched digital tomosynthesis technique localizes the tumor to an average (± standard deviation) error of 1.8 (0.7) mm for a 30° total scan angle. For the phantom study using aggregated kV-MV projections, the orthogonal-view phase-matched digital tomosynthesis localizes the tumor to an average error within 1 mm for varying magnitudes of scan angles. The pilot clinical study shows that the orthogonal-view phase-matched digital tomosynthesis technique enables fast and accurate localization of moving lung tumors.

An ice-motion tracking system at the Alaska SAR facility

NASA Technical Reports Server (NTRS)

Kwok, Ronald; Curlander, John C.; Pang, Shirley S.; Mcconnell, Ross

1990-01-01

An operational system for extracting ice-motion information from synthetic aperture radar (SAR) imagery is being developed as part of the Alaska SAR Facility. This geophysical processing system (GPS) will derive ice-motion information by automated analysis of image sequences acquired by radars on the European ERS-1, Japanese ERS-1, and Canadian RADARSAT remote sensing satellites. The algorithm consists of a novel combination of feature-based and area-based techniques for the tracking of ice floes that undergo translation and rotation between imaging passes. The system performs automatic selection of the image pairs for input to the matching routines using an ice-motion estimator. It is designed to have a daily throughput of ten image pairs. A description is given of the GPS system, including an overview of the ice-motion-tracking algorithm, the system architecture, and the ice-motion products that will be available for distribution to geophysical data users.

Bias to experience approaching motion in a three-dimensional virtual environment.

PubMed

Lewis, Clifford F; McBeath, Michael K

2004-01-01

We used two-frame apparent motion in a three-dimensional virtual environment to test whether observers had biases to experience approaching or receding motion in depth. Observers viewed a tunnel of tiles receding in depth, that moved ambiguously either toward or away from them. We found that observers exhibited biases to experience approaching motion. The strengths of the biases were decreased when stimuli pointed away, but size of the display screen had no effect. Tests with diamond-shaped tiles that varied in the degree of pointing asymmetry resulted in a linear trend in which the bias was strongest for stimuli pointing toward the viewer, and weakest for stimuli pointing away. We show that the overall bias to experience approaching motion is consistent with a computational strategy of matching corresponding features between adjacent foreshortened stimuli in consecutive visual frames. We conclude that there are both adaptational and geometric reasons to favor the experience of approaching motion.

Sensor for In-Motion Continuous 3D Shape Measurement Based on Dual Line-Scan Cameras

PubMed Central

Sun, Bo; Zhu, Jigui; Yang, Linghui; Yang, Shourui; Guo, Yin

2016-01-01

The acquisition of three-dimensional surface data plays an increasingly important role in the industrial sector. Numerous 3D shape measurement techniques have been developed. However, there are still limitations and challenges in fast measurement of large-scale objects or high-speed moving objects. The innovative line scan technology opens up new potentialities owing to the ultra-high resolution and line rate. To this end, a sensor for in-motion continuous 3D shape measurement based on dual line-scan cameras is presented. In this paper, the principle and structure of the sensor are investigated. The image matching strategy is addressed and the matching error is analyzed. The sensor has been verified by experiments and high-quality results are obtained. PMID:27869731

Ecologically Valid Carbohydrate Intake during Soccer-Specific Exercise Does Not Affect Running Performance in a Fed State

PubMed Central

Funnell, Mark P.; Dykes, Nick R.; Owen, Elliot J.; Mears, Stephen A.; Rollo, Ian; James, Lewis J.

2017-01-01

This study assessed the effect of carbohydrate intake on self-selected soccer-specific running performance. Sixteen male soccer players (age 23 ± 4 years; body mass 76.9 ± 7.2 kg; predicted VO2max = 54.2 ± 2.9 mL∙kg−1∙min−1; soccer experience 13 ± 4 years) completed a progressive multistage fitness test, familiarisation trial and two experimental trials, involving a modified version of the Loughborough Intermittent Shuttle Test (LIST) to simulate a soccer match in a fed state. Subjects completed six 15 min blocks (two halves of 45 min) of intermittent shuttle running, with a 15-min half-time. Blocks 3 and 6, allowed self-selection of running speeds and sprint times, were assessed throughout. Subjects consumed 250 mL of either a 12% carbohydrate solution (CHO) or a non-caloric taste matched placebo (PLA) before and at half-time of the LIST. Sprint times were not different between trials (CHO 2.71 ± 0.15 s, PLA 2.70 ± 0.14 s; p = 0.202). Total distance covered in self-selected blocks (block 3: CHO 2.07 ± 0.06 km; PLA 2.09 ± 0.08 km; block 6: CHO 2.04 ± 0.09 km; PLA 2.06 ± 0.08 km; p = 0.122) was not different between trials. There was no difference between trials for distance covered (p ≥ 0.297) or mean speed (p ≥ 0.172) for jogging or cruising. Blood glucose concentration was greater (p < 0.001) at the end of half-time during the CHO trial. In conclusion, consumption of 250 mL of 12% CHO solution before and at half-time of a simulated soccer match does not affect self-selected running or sprint performance in a fed state. PMID:28067762

Ecologically Valid Carbohydrate Intake during Soccer-Specific Exercise Does Not Affect Running Performance in a Fed State.

PubMed

Funnell, Mark P; Dykes, Nick R; Owen, Elliot J; Mears, Stephen A; Rollo, Ian; James, Lewis J

2017-01-05

This study assessed the effect of carbohydrate intake on self-selected soccer-specific running performance. Sixteen male soccer players (age 23 ± 4 years; body mass 76.9 ± 7.2 kg; predicted VO 2max = 54.2 ± 2.9 mL∙kg -1 ∙min -1 ; soccer experience 13 ± 4 years) completed a progressive multistage fitness test, familiarisation trial and two experimental trials, involving a modified version of the Loughborough Intermittent Shuttle Test (LIST) to simulate a soccer match in a fed state. Subjects completed six 15 min blocks (two halves of 45 min) of intermittent shuttle running, with a 15-min half-time. Blocks 3 and 6, allowed self-selection of running speeds and sprint times, were assessed throughout. Subjects consumed 250 mL of either a 12% carbohydrate solution (CHO) or a non-caloric taste matched placebo (PLA) before and at half-time of the LIST. Sprint times were not different between trials (CHO 2.71 ± 0.15 s, PLA 2.70 ± 0.14 s; p = 0.202). Total distance covered in self-selected blocks (block 3: CHO 2.07 ± 0.06 km; PLA 2.09 ± 0.08 km; block 6: CHO 2.04 ± 0.09 km; PLA 2.06 ± 0.08 km; p = 0.122) was not different between trials. There was no difference between trials for distance covered ( p ≥ 0.297) or mean speed ( p ≥ 0.172) for jogging or cruising. Blood glucose concentration was greater ( p < 0.001) at the end of half-time during the CHO trial. In conclusion, consumption of 250 mL of 12% CHO solution before and at half-time of a simulated soccer match does not affect self-selected running or sprint performance in a fed state.

Solid rocket motor fire tests: Phases 1 and 2

NASA Astrophysics Data System (ADS)

Chang, Yale; Hunter, Lawrence W.; Han, David K.; Thomas, Michael E.; Cain, Russell P.; Lennon, Andrew M.

2002-01-01

JHU/APL conducted a series of open-air burns of small blocks (3 to 10 kg) of solid rocket motor (SRM) propellant at the Thiokol Elkton MD facility to elucidate the thermal environment under burning propellant. The propellant was TP-H-3340A for the STAR 48 motor, with a weight ratio of 71/18/11 for the ammonium perchlorate, aluminum, and HTPB binder. Combustion inhibitor applied on the blocks allowed burning on the bottom and/or sides only. Burns were conducted on sand and concrete to simulate near-launch pad surfaces, and on graphite to simulate a low-recession surface. Unique test fixturing allowed propellant self-levitation while constraining lateral motion. Optics instrumentation consisted of a longwave infrared imaging pyrometer, a midwave spectroradiometer, and a UV/visible spectroradiometer. In-situ instrumentation consisted of rod calorimeters, Gardon gauges, elevated thermocouples, flush thermocouples, a two-color pyrometer, and Knudsen cells. Witness materials consisted of yttria, ceria, alumina, tungsten, iridium, and platinum/rhodium. Objectives of the tests were to determine propellant burn characteristics such as burn rate and self-levitation, to determine heat fluxes and temperatures, and to carry out materials analyses. A summary of qualitative results: alumina coated almost all surfaces, the concrete spalled, sand moisture content matters, the propellant self-levitated, the test fixtures worked as designed, and bottom-burning propellant does not self-extinguish. A summary of quantitative results: burn rate averaged 1.15 mm/s, thermocouples peaked at 2070 C, pyrometer readings matched MWIR data at about 2400 C, the volume-averaged plume temperatures were 2300-2400 C with peaks of 2400-2600 C, and the heat fluxes peaked at 125 W/cm2. These results are higher than other researchers' measurements of top-burning propellant in chimneys, and will be used, along with Phase 3 test results, to analyze hardware response to these environments, including General Purpose Heat Sources (GPHS) and Radioisotope Heater Units (RHU). Follow-on Phase 3 tests burning propellant blocks up to 90 kg will be briefly described. .

A comparison of colour, shape, and flash induced illusory line motion.

PubMed

Hamm, Jeff P

2017-04-01

When a bar suddenly appears between two boxes, the bar will appear to shoot away from the box that matches it in colour or in shape-a phenomenon referred to as attribute priming of illusory line motion (ILM; colour ILM and shape ILM, respectively). If the two boxes are identical, ILM will still occur away from a box if it changes luminance shortly before the presentation of the bar ( flash ILM). This flash condition has been suggested to produce the illusory motion due to the formation of an attentional gradient surrounding the flashed location. However, colour ILM and shape ILM cannot be explained by an attentional gradient as there is no way for attention to select the matching box prior to the presentation of the bar. These findings challenge the attentional gradient explanation for ILM, but only if it is assumed that ILM arises for the same underlying reason. Two experiments are presented that address the question of whether or not flash ILM is the same as colour ILM or shape ILM. The results suggest that while colour ILM and shape ILM reflect a common illusion, flash ILM arises for a different reason. Therefore, the attentional gradient explanation for flash ILM is not refuted by the occurrence of colour ILM or shape ILM, which may reflect transformational apparent motion (TAM).

Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques.

PubMed

Monezi, Lucas Antônio; Magalhães, Thiago Pinguelli; Morato, Márcio Pereira; Mercadante, Luciano Allegretti; Furtado, Otávio Luis Piva da Cunha; Misuta, Milton Shoiti

2018-03-26

In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players' movement patterns during goalball matches that can be used to plan more effective training.

Vertical motion simulator familiarization guide

NASA Technical Reports Server (NTRS)

Danek, George L.

1993-01-01

The Vertical Motion Simulator Familiarization Guide provides a synoptic description of the Vertical Motion Simulator (VMS) and descriptions of the various simulation components and systems. The intended audience is the community of scientists and engineers who employ the VMS for research and development. The concept of a research simulator system is introduced and the building block nature of the VMS is emphasized. Individual sections describe all the hardware elements in terms of general properties and capabilities. Also included are an example of a typical VMS simulation which graphically illustrates the composition of the system and shows the signal flow among the elements and a glossary of specialized terms, abbreviations, and acronyms.

Interactions between motion and form processing in the human visual system.

PubMed

Mather, George; Pavan, Andrea; Bellacosa Marotti, Rosilari; Campana, Gianluca; Casco, Clara

2013-01-01

The predominant view of motion and form processing in the human visual system assumes that these two attributes are handled by separate and independent modules. Motion processing involves filtering by direction-selective sensors, followed by integration to solve the aperture problem. Form processing involves filtering by orientation-selective and size-selective receptive fields, followed by integration to encode object shape. It has long been known that motion signals can influence form processing in the well-known Gestalt principle of common fate; texture elements which share a common motion property are grouped into a single contour or texture region. However, recent research in psychophysics and neuroscience indicates that the influence of form signals on motion processing is more extensive than previously thought. First, the salience and apparent direction of moving lines depends on how the local orientation and direction of motion combine to match the receptive field properties of motion-selective neurons. Second, orientation signals generated by "motion-streaks" influence motion processing; motion sensitivity, apparent direction and adaptation are affected by simultaneously present orientation signals. Third, form signals generated by human body shape influence biological motion processing, as revealed by studies using point-light motion stimuli. Thus, form-motion integration seems to occur at several different levels of cortical processing, from V1 to STS.

Interactions between motion and form processing in the human visual system

PubMed Central

Mather, George; Pavan, Andrea; Bellacosa Marotti, Rosilari; Campana, Gianluca; Casco, Clara

2013-01-01

The predominant view of motion and form processing in the human visual system assumes that these two attributes are handled by separate and independent modules. Motion processing involves filtering by direction-selective sensors, followed by integration to solve the aperture problem. Form processing involves filtering by orientation-selective and size-selective receptive fields, followed by integration to encode object shape. It has long been known that motion signals can influence form processing in the well-known Gestalt principle of common fate; texture elements which share a common motion property are grouped into a single contour or texture region. However, recent research in psychophysics and neuroscience indicates that the influence of form signals on motion processing is more extensive than previously thought. First, the salience and apparent direction of moving lines depends on how the local orientation and direction of motion combine to match the receptive field properties of motion-selective neurons. Second, orientation signals generated by “motion-streaks” influence motion processing; motion sensitivity, apparent direction and adaptation are affected by simultaneously present orientation signals. Third, form signals generated by human body shape influence biological motion processing, as revealed by studies using point-light motion stimuli. Thus, form-motion integration seems to occur at several different levels of cortical processing, from V1 to STS. PMID:23730286

3D Volume and Morphology of Perennial Cave Ice and Related Geomorphological Models at Scăriloara Ice Cave, Romania, from Structure from Motion, Ground Penetrating Radar and Total Station Surveys

NASA Astrophysics Data System (ADS)

Hubbard, J.; Onac, B. P.; Kruse, S.; Forray, F. L.

2017-12-01

Research at Scăriloara Ice Cave has proceeded for over 150 years, primarily driven by the presence and paleoclimatic importance of the large perennial ice block and various ice speleothems located within its galleries. Previous observations of the ice block led to rudimentary volume estimates of 70,000 to 120,000 cubic meters (m3), prospectively placing it as one of the world's largest cave ice deposits. The cave morphology and the surface of the ice block are now recreated in a total station survey-validated 3D model, produced using Structure from Motion (SfM) software. With the total station survey and the novel use of ArcGIS tools, the SfM validation process is drastically simplified to produce a scaled, georeferenced, and photo-texturized 3D model of the cave environment with a root-mean-square error (RMSE) of 0.24 m. Furthermore, ground penetrating radar data was collected and spatially oriented with the total station survey to recreate the ice block basal surface and was combined with the SfM model to create a model of the ice block itself. The resulting ice block model has a volume of over 118,000 m3 with an uncertainty of 9.5%, with additional volumes left un-surveyed. The varying elevation of the ice block basal surface model reflect specific features of the cave roof, such as areas of enlargement, shafts, and potential joints, which offer further validation and inform theories on cave and ice genesis. Specifically, a large depression area was identified as a potential area of initial ice growth. Finally, an ice thickness map was produced that will aid in the designing of future ice coring projects. This methodology presents a powerful means to observe and accurately characterize and measure cave and cave ice morphologies with ease and affordability. Results further establish the significance of Scăriloara's ice block to paleoclimate research, provide insights into cave and ice block genesis, and aid future study design.

On the use of INS to improve Feature Matching

NASA Astrophysics Data System (ADS)

Masiero, A.; Guarnieri, A.; Vettore, A.; Pirotti, F.

2014-11-01

The continuous technological improvement of mobile devices opens the frontiers of Mobile Mapping systems to very compact systems, i.e. a smartphone or a tablet. This motivates the development of efficient 3D reconstruction techniques based on the sensors typically embedded in such devices, i.e. imaging sensors, GPS and Inertial Navigation System (INS). Such methods usually exploits photogrammetry techniques (structure from motion) to provide an estimation of the geometry of the scene. Actually, 3D reconstruction techniques (e.g. structure from motion) rely on use of features properly matched in different images to compute the 3D positions of objects by means of triangulation. Hence, correct feature matching is of fundamental importance to ensure good quality 3D reconstructions. Matching methods are based on the appearance of features, that can change as a consequence of variations of camera position and orientation, and environment illumination. For this reason, several methods have been developed in recent years in order to provide feature descriptors robust (ideally invariant) to such variations, e.g. Scale-Invariant Feature Transform (SIFT), Affine SIFT, Hessian affine and Harris affine detectors, Maximally Stable Extremal Regions (MSER). This work deals with the integration of information provided by the INS in the feature matching procedure: a previously developed navigation algorithm is used to constantly estimate the device position and orientation. Then, such information is exploited to estimate the transformation of feature regions between two camera views. This allows to compare regions from different images but associated to the same feature as seen by the same point of view, hence significantly easing the comparison of feature characteristics and, consequently, improving matching. SIFT-like descriptors are used in order to ensure good matching results in presence of illumination variations and to compensate the approximations related to the estimation process.

Phase-linking and the perceived motion during off-vertical axis rotation.

PubMed

Holly, Jan E; Wood, Scott J; McCollum, Gin

2010-01-01

Human off-vertical axis rotation (OVAR) in the dark typically produces perceived motion about a cone, the amplitude of which changes as a function of frequency. This perception is commonly attributed to the fact that both the OVAR and the conical motion have a gravity vector that rotates about the subject. Little-known, however, is that this rotating-gravity explanation for perceived conical motion is inconsistent with basic observations about self-motion perception: (a) that the perceived vertical moves toward alignment with the gravito-inertial acceleration (GIA) and (b) that perceived translation arises from perceived linear acceleration, as derived from the portion of the GIA not associated with gravity. Mathematically proved in this article is the fact that during OVAR these properties imply mismatched phase of perceived tilt and translation, in contrast to the common perception of matched phases which correspond to conical motion with pivot at the bottom. This result demonstrates that an additional perceptual rule is required to explain perception in OVAR. This study investigates, both analytically and computationally, the phase relationship between tilt and translation at different stimulus rates-slow (45 degrees /s) and fast (180 degrees /s), and the three-dimensional shape of predicted perceived motion, under different sets of hypotheses about self-motion perception. We propose that for human motion perception, there is a phase-linking of tilt and translation movements to construct a perception of one's overall motion path. Alternative hypotheses to achieve the phase match were tested with three-dimensional computational models, comparing the output with published experimental reports. The best fit with experimental data was the hypothesis that the phase of perceived translation was linked to perceived tilt, while the perceived tilt was determined by the GIA. This hypothesis successfully predicted the bottom-pivot cone commonly reported and a reduced sense of tilt during fast OVAR. Similar considerations apply to the hilltop illusion often reported during horizontal linear oscillation. Known response properties of central neurons are consistent with this ability to phase-link translation with tilt. In addition, the competing "standard" model was mathematically proved to be unable to predict the bottom-pivot cone regardless of the values used for parameters in the model.

Structure and Dynamics of Ionic Block Copolymer Melts: Computational Study

DOE PAGES

Aryal, Dipak; Agrawal, Anupriya; Perahia, Dvora; ...

2017-09-06

Structure and dynamics of melts of copolymers with an ABCBA topology, where C is an ionizable block, have been studied by fully atomistic molecular dynamics (MD) simulations. Introducing an ionizable block for functionality adds a significant element to the coupled set of interactions that determine the structure and dynamics of the macromolecule. The polymer consists of a randomly sulfonated polystyrene C block tethered to a flexible poly(ethylene-r-propylene) bridge B and end-capped with poly(tert-butylstyrene) A. The chemical structure and topology of these polymers constitute a model for incorporation of ionic blocks within a framework that provides tactility and mechanical stability. Heremore » in this paper we resolve the structure and dynamics of a structured polymer on the nanoscale constrained by ionic clusters. We find that the melts form intertwined networks of the A and C blocks independent of the degree of sulfonation of the C block with no long-range order. The cluster cohesiveness and morphology affect both macroscopic translational motion and segmental dynamics of all the blocks.« less

Structure and Dynamics of Ionic Block Copolymer Melts: Computational Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aryal, Dipak; Agrawal, Anupriya; Perahia, Dvora

Structure and dynamics of melts of copolymers with an ABCBA topology, where C is an ionizable block, have been studied by fully atomistic molecular dynamics (MD) simulations. Introducing an ionizable block for functionality adds a significant element to the coupled set of interactions that determine the structure and dynamics of the macromolecule. The polymer consists of a randomly sulfonated polystyrene C block tethered to a flexible poly(ethylene-r-propylene) bridge B and end-capped with poly(tert-butylstyrene) A. The chemical structure and topology of these polymers constitute a model for incorporation of ionic blocks within a framework that provides tactility and mechanical stability. Heremore » in this paper we resolve the structure and dynamics of a structured polymer on the nanoscale constrained by ionic clusters. We find that the melts form intertwined networks of the A and C blocks independent of the degree of sulfonation of the C block with no long-range order. The cluster cohesiveness and morphology affect both macroscopic translational motion and segmental dynamics of all the blocks.« less

Bayesian Decision Tree for the Classification of the Mode of Motion in Single-Molecule Trajectories

PubMed Central

Türkcan, Silvan; Masson, Jean-Baptiste

2013-01-01

Membrane proteins move in heterogeneous environments with spatially (sometimes temporally) varying friction and with biochemical interactions with various partners. It is important to reliably distinguish different modes of motion to improve our knowledge of the membrane architecture and to understand the nature of interactions between membrane proteins and their environments. Here, we present an analysis technique for single molecule tracking (SMT) trajectories that can determine the preferred model of motion that best matches observed trajectories. The method is based on Bayesian inference to calculate the posteriori probability of an observed trajectory according to a certain model. Information theory criteria, such as the Bayesian information criterion (BIC), the Akaike information criterion (AIC), and modified AIC (AICc), are used to select the preferred model. The considered group of models includes free Brownian motion, and confined motion in 2nd or 4th order potentials. We determine the best information criteria for classifying trajectories. We tested its limits through simulations matching large sets of experimental conditions and we built a decision tree. This decision tree first uses the BIC to distinguish between free Brownian motion and confined motion. In a second step, it classifies the confining potential further using the AIC. We apply the method to experimental Clostridium Perfingens -toxin (CPT) receptor trajectories to show that these receptors are confined by a spring-like potential. An adaptation of this technique was applied on a sliding window in the temporal dimension along the trajectory. We applied this adaptation to experimental CPT trajectories that lose confinement due to disaggregation of confining domains. This new technique adds another dimension to the discussion of SMT data. The mode of motion of a receptor might hold more biologically relevant information than the diffusion coefficient or domain size and may be a better tool to classify and compare different SMT experiments. PMID:24376584

SU-F-303-11: Implementation and Applications of Rapid, SIFT-Based Cine MR Image Binning and Region Tracking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazur, T; Wang, Y; Fischer-Valuck, B

2015-06-15

Purpose: To develop a novel and rapid, SIFT-based algorithm for assessing feature motion on cine MR images acquired during MRI-guided radiotherapy treatments. In particular, we apply SIFT descriptors toward both partitioning cine images into respiratory states and tracking regions across frames. Methods: Among a training set of images acquired during a fraction, we densely assign SIFT descriptors to pixels within the images. We cluster these descriptors across all frames in order to produce a dictionary of trackable features. Associating the best-matching descriptors at every frame among the training images to these features, we construct motion traces for the features. Wemore » use these traces to define respiratory bins for sorting images in order to facilitate robust pixel-by-pixel tracking. Instead of applying conventional methods for identifying pixel correspondences across frames we utilize a recently-developed algorithm that derives correspondences via a matching objective for SIFT descriptors. Results: We apply these methods to a collection of lung, abdominal, and breast patients. We evaluate the procedure for respiratory binning using target sites exhibiting high-amplitude motion among 20 lung and abdominal patients. In particular, we investigate whether these methods yield minimal variation between images within a bin by perturbing the resulting image distributions among bins. Moreover, we compare the motion between averaged images across respiratory states to 4DCT data for these patients. We evaluate the algorithm for obtaining pixel correspondences between frames by tracking contours among a set of breast patients. As an initial case, we track easily-identifiable edges of lumpectomy cavities that show minimal motion over treatment. Conclusions: These SIFT-based methods reliably extract motion information from cine MR images acquired during patient treatments. While we performed our analysis retrospectively, the algorithm lends itself to prospective motion assessment. Applications of these methods include motion assessment, identifying treatment windows for gating, and determining optimal margins for treatment.« less

The Tonalá fault in southeastern Mexico: Evidence that the Central America forearc sliver is not being detached?

NASA Astrophysics Data System (ADS)

Guzman-Speziale, M.; Molina-Garza, R. S.

2012-12-01

The Tonalá fault is a NW-SE oriented feature that flanks the Chiapas Massif on its southwestern side. Several authors coincide that the fault originally developed as a right-lateral structure in the Jurassic, but was reactivated as a left-lateral fault in the Miocene. Seismicity along the fault is low: Only one earthquake with magnitude 5.0 or larger is reported along the Tonalá fault in the years 1964 to present. Fault-plane solutions determined by the Mexican Seismological Survey for earthquakes along the fault show left-lateral, strike-slip faulting. The Tonalá fault lies on the northwestern continuation of the Central America volcanic arc. The volcanic arc is the site of medium-sized (magnitudes up to 6.5) shallow, right-lateral, strike-slip earthquakes. This has led several workers to propose that the forearc sliver is being detached from the Caribbean plate along the arc, moving northward. GPS studies have confirmed relative motion between the Chortis block and the forearc sliver. Recent and current motion along the Tonalá fault is in contradiction with motion and detachment of the forearc sliver along the Central America volcanic arc. Left-lateral motion along it cannot accomodate northwest displacement of the forearc sliver. Motion of the Central America forearc would require NW directed compression between the continental shelf of Chiapas and the forearc itself, which is not observed. Therefore, either another fault (or faults) accomodates right-lateral motion and detachment of the forearc sliver, or the sliver is not being detached and relative motion between the forearc sliver and the Chortis block corresponds to displacement of the latter. We suggest that, as proposed by previous authors, the Tonalá fault is instead part of a fault system that runs from the state of Oaxaca (the Valle Nacional fault), forming an arc concave to the northeast, and running perpendicular to the maximum slope of subduction in the area.

Simulation of ground motion using the stochastic method

USGS Publications Warehouse

Boore, D.M.

2003-01-01

A simple and powerful method for simulating ground motions is to combine parametric or functional descriptions of the ground motion's amplitude spectrum with a random phase spectrum modified such that the motion is distributed over a duration related to the earthquake magnitude and to the distance from the source. This method of simulating ground motions often goes by the name "the stochastic method." It is particularly useful for simulating the higher-frequency ground motions of most interest to engineers (generally, f>0.1 Hz), and it is widely used to predict ground motions for regions of the world in which recordings of motion from potentially damaging earthquakes are not available. This simple method has been successful in matching a variety of ground-motion measures for earthquakes with seismic moments spanning more than 12 orders of magnitude and in diverse tectonic environments. One of the essential characteristics of the method is that it distills what is known about the various factors affecting ground motions (source, path, and site) into simple functional forms. This provides a means by which the results of the rigorous studies reported in other papers in this volume can be incorporated into practical predictions of ground motion.

SOSlope: a new slope stability model for vegetated hillslopes

NASA Astrophysics Data System (ADS)

Cohen, D.; Schwarz, M.

2016-12-01

Roots contribute to increase soil strength but forces mobilized by roots depend on soil relative displacement. This effect is not included in models of slope stability. Here we present a new numerical model of shallow landslides for vegetated hillslopes that uses a strain-step loading approach for force redistributions within a soil mass including the effects of root strength in both tension and compression. The hillslope is discretized into a two-dimensional array of blocks connected by bonds. During a rainfall event the blocks's mass increases and the soil shear strength decreases. At each time step, we compute a factor of safety for each block. If the factor of safety of one or more blocks is less than one, those blocks are moved in the direction of the local active force by a predefined amount and the factor of safety is recalculated for all blocks. Because of the relative motion between blocks that have moved and those that remain stationary, mechanical bond forces between blocks that depend on relative displacement change, modifying the force balance. This relative motion triggers instantaneous force redistributions across the entire hillslope similar to a self-organized critical system. Looping over blocks and moving those that are unstable is repeated until all blocks are stable and the system reaches a new equilibrium, or, some blocks have failed causing a landslide. Spatial heterogeneity of vegetation is included by computing the root density and distribution as a function of distance form trees. A simple subsurface hydrological model based on dual permeability concepts is used to compute the temporal evolution of water content, pore-water pressure, suction stress, and soil shear strength. Simulations for a conceptual slope indicates that forces mobilized in tension and compression both contribute to the stability of the slope. However, the maximum tensional and compressional forces imparted by roots do not contribute simultaneously to the stability of the soil mass, in contrast to what is commonly assumed in models. Simulations with different tree sizes (different magnitude of root reinforcement) indicate that there is a threshold in tree spacing (or tree diameter) above (or below) which root density and root sizes no longer provide sufficient reinforcement to keep the slope stable during a rainfall event.

The importance of phrenic nerve preservation and its effect on long-term postoperative lung function after pneumonectomy.

PubMed

Kocher, Gregor J; Poulson, Jannie Lysgaard; Blichfeldt-Eckhardt, Morten Rune; Elle, Bo; Schmid, Ralph A; Licht, Peter B

2016-04-01

The importance of phrenic nerve preservation during pneumonectomy remains controversial. We previously demonstrated that preservation of the phrenic nerve in the immediate postoperative period preserved lung function by 3-5% but little is known about its long-term effects. We, therefore, decided to investigate the effect of temporary ipsilateral cervical phrenic nerve block on dynamic lung volumes in mid- to long-term pneumonectomy patients. We investigated 14 patients after a median of 9 years post pneumonectomy (range: 1-15 years). Lung function testing (spirometry) and fluoroscopic and/or sonographic assessment of diaphragmatic motion on the pneumonectomy side were performed before and after ultrasonographic-guided ipsilateral cervical phrenic nerve block by infiltration with lidocaine. Ipsilateral phrenic nerve block was successfully achieved in 12 patients (86%). In the remaining 2 patients, diaphragmatic motion was already paradoxical before the nerve block. We found no significant difference on dynamic lung function values (FEV1 'before' 1.39 ± 0.44 vs FEV1 'after' 1.38 ± 0.40; P = 0.81). Induction of a temporary diaphragmatic palsy did not significantly influence dynamic lung volumes in mid- to long-term pneumonectomy patients, suggesting that preservation of the phrenic nerve is of greater importance in the immediate postoperative period after pneumonectomy. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Broadscale postseismic deformation and lower crustal relaxation in the central Bayankala Block (central Tibetan Plateau) observed using InSAR data

NASA Astrophysics Data System (ADS)

Zhao, Dezheng; Qu, Chunyan; Shan, Xinjian; Zuo, Ronghu; Liu, Yunhua; Gong, Wenyu; Zhang, Guohong

2018-04-01

We have generated a more than 500 km long postseismic deformation rate map and cumulative displacement time series in the central Bayankala Block of the Tibetan Plateau using ENVISAT/ASAR data from 2003 to 2010 by the π-RATE stacking algorithm. This rate map spans a period of ∼7.2 years and reveals that postseismic motion of 2001 Kokoxili earthquake exhibits a striking signal, dominating crustal deformation of the central Bayankala Block with a cross-fault magnitude ∼9-11 mm/yr in line of sight (LOS) (∼93.1°E). The southern and northern parts of the postseismic deformation field exhibit different patterns and variable magnitudes, reflecting asymmetry of the displacement distribution. Postseismic motion affects eastward extrusion of the central Bayankala Block, which reaches ∼15 km north of the Ganzi-Yushu fault. To further investigate viscoelastic relaxation of the lower crust in this area after approximately two years, E-M, E-M-M and E-S models are constructed. The result shows that the best fit viscosity for the lower crust is about 1 × 1019 Pa·s. Comparison between cumulative displacements resolved by these three models shows that viscoelastic relaxation of the lower crust makes the most significant contribution to postseismic stress relaxation after 2001 event.

Incorrect Match Detection Method for Arctic Sea-Ice Reconstruction Using Uav Images

NASA Astrophysics Data System (ADS)

Kim, J.-I.; Kim, H.-C.

2018-05-01

Shapes and surface roughness, which are considered as key indicators in understanding Arctic sea-ice, can be measured from the digital surface model (DSM) of the target area. Unmanned aerial vehicle (UAV) flying at low altitudes enables theoretically accurate DSM generation. However, the characteristics of sea-ice with textureless surface and incessant motion make image matching difficult for DSM generation. In this paper, we propose a method for effectively detecting incorrect matches before correcting a sea-ice DSM derived from UAV images. The proposed method variably adjusts the size of search window to analyze the matching results of DSM generated and distinguishes incorrect matches. Experimental results showed that the sea-ice DSM produced large errors along the textureless surfaces, and that the incorrect matches could be effectively detected by the proposed method.

Models for extracting vertical crustal movements from leveling data

NASA Technical Reports Server (NTRS)

Holdahl, S. H.

1978-01-01

Various adjustment strategies are being used in North America to obtain vertical crustal movements from repeated leveling. The more successful models utilize polynomials or multiquadric analysis to describe elevation change with a velocity surface. Other features permit determination of nonlinear motions, motions associated with earthquakes or episodes, and vertical motions of blocks where boundaries are prespecified. The preferred models for estimating crustal motions permit the use of detached segments of releveling to govern the shape of a velocity surface and allow for input from nonleveling sources such as tide gages and paired lake gages. Some models for extracting vertical crustal movements from releveling data are also excellent for adjusting leveling networks, and permit mixing old and new data in areas exhibiting vertical motion. The new adjustment techniques are more general than older static models and will undoubtedly be used routinely in the future as the constitution of level networks becomes mainly relevelings.

Emulation of rocket trajectory based on a six degree of freedom model

NASA Astrophysics Data System (ADS)

Zhang, Wenpeng; Li, Fan; Wu, Zhong; Li, Rong

2008-10-01

In this paper, a 6-DOF motion mathematical model is discussed. It is consisted of body dynamics and kinematics block, aero dynamics block and atmosphere block. Based on Simulink, the whole rocket trajectory mathematical model is developed. In this model, dynamic system simulation becomes easy and visual. The method of modularization design gives more convenience to transplant. At last, relevant data is given to be validated by Monte Carlo means. Simulation results show that the flight trajectory of the rocket can be simulated preferably by means of this model, and it also supplies a necessary simulating tool for the development of control system.

Effects of Badminton Expertise on Representational Momentum: A Combination of Cross-Sectional and Longitudinal Studies

PubMed Central

Jin, Hua; Wang, Pin; Fang, Zhuo; Di, Xin; Ye, Zhuo’er; Xu, Guiping; Lin, Huiyan; Cheng, Yongmin; Li, Yongjie; Xu, Yong; Rao, Hengyi

2017-01-01

Representational momentum (RM) has been found to be magnified in experts (e.g., sport players) with respect to both real and implied motion in expert-familiar domains. However, it remains unclear whether similar effects can be achieved in expert-unfamiliar domains, especially within the context of implied motion. To answer this question, we conducted two independent experiments using an implied motion paradigm and examined the expert effects of badminton training on RM in both adult and child players. In Experiment 1, we used a cross-sectional design and compared RM between adult professional badminton players and matched controls. The results revealed significantly enhanced RM for adult players, supporting the expert effect in expert-unfamiliar domains for implied motion. However, cross-sectional studies could not ascertain whether the observed expert effect was due to innate factors or expertise acquirement. Therefore, in Experiment 2, we used a longitudinal design and compared RM between two groups of child participants, naming child players who had enrolled professional badminton training program at a sports school and age-matched peer non-players who attended an ordinary primary school without sports training. Before training, there were no differences in RM among child players, their non-player peers, and adult non-players. However, after 4 years of badminton training, child players demonstrated significantly enhanced RM compared to themselves prior to training. The increased RM observed in both adult and child players suggests that badminton expertise modulates implied motion RM. PMID:28970810

Real-Time Tracking by Double Templates Matching Based on Timed Motion History Image with HSV Feature

PubMed Central

Li, Zhiyong; Li, Pengfei; Yu, Xiaoping; Hashem, Mervat

2014-01-01

It is a challenge to represent the target appearance model for moving object tracking under complex environment. This study presents a novel method with appearance model described by double templates based on timed motion history image with HSV color histogram feature (tMHI-HSV). The main components include offline template and online template initialization, tMHI-HSV-based candidate patches feature histograms calculation, double templates matching (DTM) for object location, and templates updating. Firstly, we initialize the target object region and calculate its HSV color histogram feature as offline template and online template. Secondly, the tMHI-HSV is used to segment the motion region and calculate these candidate object patches' color histograms to represent their appearance models. Finally, we utilize the DTM method to trace the target and update the offline template and online template real-timely. The experimental results show that the proposed method can efficiently handle the scale variation and pose change of the rigid and nonrigid objects, even in illumination change and occlusion visual environment. PMID:24592185

Analysis of the orbit distortion by the use of the wavelet transform

NASA Astrophysics Data System (ADS)

Matsushita, T.; Agui, A.; Yoshigoe, A.; Takao, M.; Aoyagi, H.; Takeuchi, M.; Nakatani, T.; Tanaka, H.

2004-05-01

We have adopted matching pursuit algorithm of discrete wavelet transform (DWT) for the analysis of the beam position shift correlated with the motion of insertion device(ID). The beam position data measured by the rf beam position monitors have included high-frequency `noises' and fluctuation of background level. Precise evaluation of the electron beam position shift correlated with the motion of the ID is required for estimation of the steering magnet currents in order to suppress the closed orbit distortion (COD). The DWT is a powerful tool for frequency analysis and data processing. The analysis of DWT was applied to the beam position shift correlated with the phase motion of APPLE-2 type undulator (ID23) in SPring-8. The result of the analysis indicated that `noises' are mainly composed of the components of 50 ˜ 6.25Hz and < 0.1Hz. We carried out the data processing to remove the `noises' by the matching pursuit algorithm. Then we have succeeded in suppressing the COD within 2 μm by the use of the steering magnet currents calculated from the processed data.

A neural model of motion processing and visual navigation by cortical area MST.

PubMed

Grossberg, S; Mingolla, E; Pack, C

1999-12-01

Cells in the dorsal medial superior temporal cortex (MSTd) process optic flow generated by self-motion during visually guided navigation. A neural model shows how interactions between well-known neural mechanisms (log polar cortical magnification, Gaussian motion-sensitive receptive fields, spatial pooling of motion-sensitive signals and subtractive extraretinal eye movement signals) lead to emergent properties that quantitatively simulate neurophysiological data about MSTd cell properties and psychophysical data about human navigation. Model cells match MSTd neuron responses to optic flow stimuli placed in different parts of the visual field, including position invariance, tuning curves, preferred spiral directions, direction reversals, average response curves and preferred locations for stimulus motion centers. The model shows how the preferred motion direction of the most active MSTd cells can explain human judgments of self-motion direction (heading), without using complex heading templates. The model explains when extraretinal eye movement signals are needed for accurate heading perception, and when retinal input is sufficient, and how heading judgments depend on scene layouts and rotation rates.

Spatial resolution properties of motion-compensated tomographic image reconstruction methods.

PubMed

Chun, Se Young; Fessler, Jeffrey A

2012-07-01

Many motion-compensated image reconstruction (MCIR) methods have been proposed to correct for subject motion in medical imaging. MCIR methods incorporate motion models to improve image quality by reducing motion artifacts and noise. This paper analyzes the spatial resolution properties of MCIR methods and shows that nonrigid local motion can lead to nonuniform and anisotropic spatial resolution for conventional quadratic regularizers. This undesirable property is akin to the known effects of interactions between heteroscedastic log-likelihoods (e.g., Poisson likelihood) and quadratic regularizers. This effect may lead to quantification errors in small or narrow structures (such as small lesions or rings) of reconstructed images. This paper proposes novel spatial regularization design methods for three different MCIR methods that account for known nonrigid motion. We develop MCIR regularization designs that provide approximately uniform and isotropic spatial resolution and that match a user-specified target spatial resolution. Two-dimensional PET simulations demonstrate the performance and benefits of the proposed spatial regularization design methods.

Crab Pulsar Astrometry and Spin-Velocity Alignment

NASA Astrophysics Data System (ADS)

Romani, Roger W.; Ng, C.-Y.

2009-01-01

The proper motion of the Crab pulsar and its orientation with respect to the PWN symmetry axis is interesting for testing models of neutron star birth kicks. A number of authors have measured the Crab's motion using archival HST images. The most detailed study by Kaplan et al. (2008) compares a wide range of WFPC and ACS images to obtain an accurate proper motion measurement. However, they concluded that a kick comparison is fundamentally limited by the uncertainty in the progenitor's motion. Here we report on new HST images matched to 1994 and 1995 data frames, providing independent proper motion measurement with over 13 year time base and minimal systematic errors. The new observations also allow us to estimate the systematic errors due to CCD saturation. Our preliminary result indicates a proper motion consistent with Kaplan et al.'s finding. We discuss a model for the progenitor's motion, suggesting that the pulsar spin is much closer to alignment than previously suspected.

The prehistoric Vajont rockslide: An updated geological model

NASA Astrophysics Data System (ADS)

Paronuzzi, Paolo; Bolla, Alberto

2012-10-01

This study presents the detailed reconstruction of the entire structure of the prehistoric Vajont rockslide (about 270-300 million m3 of rocks and debris) for the first time, describing the complex geometry and the characteristic superimposition of distinct rigid blocks on a very thick shear zone. The prehistoric Vajont rockslide was characterized by an enormous 'en masse' motion of a rigid overlying rock mass (100-130 m thick) that moved downslope, sliding onto a very thick shear zone (40-50 m thick, on average) made up of a chaotic assemblage of blocks, limestone angular gravel, and high plasticity clays (montmorillonitic clays). Coarse loose sediments, still exposed on the 9 October 1963 detachment surface, are always associated with large blocks made of strongly fractured rock masses (Fonzaso Formation: middle-upper Jurassic) preserving the stratification. The blocks of stratified and folded limestone sequences appear to be 'sheared off' from the underlying bedrock and can be considered as displaced rock masses planed off by the motion of the overlying rigid rock mass ('rock mass shavings'). The prehistoric Vajont rockslide was characterized by a multistage failure with a marked retrogressive evolution. The first rupture (Pian del Toc block) rapidly destabilized the upper slope, mobilizing a second rock mass block (Pian della Pozza block) that, in turn, determined the multiple rupture of the revealed shear zone material (Massalezza lobe). Even if the exact timing of the different phases is not known, the entire multistaged failure process was very rapid. At the end of the multistage retrogressive failure, the slope morphology of the northern toe of Mt. Toc was drastically changed and the large failed rock mass settled into the preexisting Vajont Valley assuming the unusual chair-like geometry. The Vajont rockslide represents a very significant example on how a complex geological situation, if not adequately analyzed and reconstructed, can lead to dangerous misinterpretations or even to erroneous engineering-geological and geotechnical models. Accurate fieldwork and modern technologies can be fundamental in solving such a very intriguing 'geological puzzle.'

Focal mechanisms and the stress regime in NE and SW Tanzania, East Africa

NASA Astrophysics Data System (ADS)

Brazier, Richard A.; Nyblade, Andrew A.; Florentin, Juliette

2005-07-01

We report 12 new focal mechanisms from earthquakes in NE and SW Tanzania where the stress regime within the East African rift system is not well constrained. Focal mechanisms for events at the intersection of the Lake Tanganyika and Rukwa rifts in SW Tanzania indicate a complicated stress pattern with possible dextral strike-slip motion on some faults but oblique motion on others (either sinistral on NW striking faults or dextral on NE striking faults). Within the Rukwa rift, focal mechanisms indicate normal dip-slip motion with NE-SW opening. In NE Tanzania where the Eastern rift impinges on the margin of the Tanzania Craton, fault motions are consistent with a zone of distributed block faults and sub E-W extension. All twelve earthquakes likely nucleated within the crust.

Swimming invariant manifolds and the motion of bacteria in a fluid flow

NASA Astrophysics Data System (ADS)

Yoest, Helena; Mitchell, Kevin; Solomon, Tom

2017-11-01

We present experiments on the motion of both wild-type and smooth-swimming bacillus subtilis in a hyperbolic, microfluidic fluid flow. Passive invariant manifolds crossing the fixed point in the flow act as barriers that block inert tracers in the flow. Self-propelled tracers can cross these passive manifolds, but are blocked by and attracted to swimming invariant manifolds (SWIMs) that split from the passive manifolds with larger and larger non-dimensional swimming speed v0 ≡V0 / U , where V0 is the swimming speed in the absence of a flow and U is a characteristic flos speed. We present the theory that predicts these SWIMs for smooth-swimming tracers, along with experiments that we are conducting to test these theories. We also discuss potential effects of rheotaxis and chemotaxis on the phenomena. Supported by NSF Grant DMR-1361881.

The Role of Perceived Speed in Vection: Does Perceived Speed Modulate the Jitter and Oscillation Advantages?

PubMed Central

Apthorp, Deborah; Palmisano, Stephen

2014-01-01

Illusory self-motion (‘vection’) in depth is strongly enhanced when horizontal/vertical simulated viewpoint oscillation is added to optic flow inducing displays; a similar effect is found for simulated viewpoint jitter. The underlying cause of these oscillation and jitter advantages for vection is still unknown. Here we investigate the possibility that perceived speed of motion in depth (MID) plays a role. First, in a 2AFC procedure, we obtained MID speed PSEs for briefly presented (vertically oscillating and smooth) radial flow displays. Then we examined the strength, duration and onset latency of vection induced by oscillating and smooth radial flow displays matched either for simulated or perceived MID speed. The oscillation advantage was eliminated when displays were matched for perceived MID speed. However, when we tested the jitter advantage in the same manner, jittering displays were found to produce greater vection in depth than speed-matched controls. In summary, jitter and oscillation advantages were the same across experiments, but slower MID speed was required to match jittering than oscillating stimuli. Thus, to the extent that vection is driven by perceived speed of MID, this effect is greater for oscillating than for jittering stimuli, which suggests that the two effects may arise from separate mechanisms. PMID:24651861

Differential responses in dorsal visual cortex to motion and disparity depth cues

PubMed Central

Arnoldussen, David M.; Goossens, Jeroen; van den Berg, Albert V.

2013-01-01

We investigated how interactions between monocular motion parallax and binocular cues to depth vary in human motion areas for wide-field visual motion stimuli (110 × 100°). We used fMRI with an extensive 2 × 3 × 2 factorial blocked design in which we combined two types of self-motion (translational motion and translational + rotational motion), with three categories of motion inflicted by the degree of noise (self-motion, distorted self-motion, and multiple object-motion), and two different view modes of the flow patterns (stereo and synoptic viewing). Interactions between disparity and motion category revealed distinct contributions to self- and object-motion processing in 3D. For cortical areas V6 and CSv, but not the anterior part of MT+ with bilateral visual responsiveness (MT+/b), we found a disparity-dependent effect of rotational flow and noise: When self-motion perception was degraded by adding rotational flow and moderate levels of noise, the BOLD responses were reduced compared with translational self-motion alone, but this reduction was cancelled by adding stereo information which also rescued the subject's self-motion percept. At high noise levels, when the self-motion percept gave way to a swarm of moving objects, the BOLD signal strongly increased compared to self-motion in areas MT+/b and V6, but only for stereo in the latter. BOLD response did not increase for either view mode in CSv. These different response patterns indicate different contributions of areas V6, MT+/b, and CSv to the processing of self-motion perception and the processing of multiple independent motions. PMID:24339808

Fault Structural Control on Earthquake Strong Ground Motions: The 2008 Wenchuan Earthquake as an Example

NASA Astrophysics Data System (ADS)

Zhang, Yan; Zhang, Dongli; Li, Xiaojun; Huang, Bei; Zheng, Wenjun; Wang, Yuejun

2018-02-01

Continental thrust faulting earthquakes pose severe threats to megacities across the world. Recent events show the possible control of fault structures on strong ground motions. The seismogenic structure of the 2008 Wenchuan earthquake is associated with high-angle listric reverse fault zones. Its peak ground accelerations (PGAs) show a prominent feature of fault zone amplification: the values within the 30- to 40-km-wide fault zone block are significantly larger than those on both the hanging wall and the footwall. The PGA values attenuate asymmetrically: they decay much more rapidly in the footwall than in the hanging wall. The hanging wall effects can be seen on both the vertical and horizontal components of the PGAs, with the former significantly more prominent than the latter. All these characteristics can be adequately interpreted by upward extrusion of the high-angle listric reverse fault zone block. Through comparison with a low-angle planar thrust fault associated with the 1999 Chi-Chi earthquake, we conclude that different fault structures might have controlled different patterns of strong ground motion, which should be taken into account in seismic design and construction.

Stochastic point-source modeling of ground motions in the Cascadia region

USGS Publications Warehouse

Atkinson, G.M.; Boore, D.M.

1997-01-01

A stochastic model is used to develop preliminary ground motion relations for the Cascadia region for rock sites. The model parameters are derived from empirical analyses of seismographic data from the Cascadia region. The model is based on a Brune point-source characterized by a stress parameter of 50 bars. The model predictions are compared to ground-motion data from the Cascadia region and to data from large earthquakes in other subduction zones. The point-source simulations match the observations from moderate events (M 100 km). The discrepancy at large magnitudes suggests further work on modeling finite-fault effects and regional attenuation is warranted. In the meantime, the preliminary equations are satisfactory for predicting motions from events of M < 7 and provide conservative estimates of motions from larger events at distances less than 100 km.

Generating Concise Rules for Human Motion Retrieval

NASA Astrophysics Data System (ADS)

Mukai, Tomohiko; Wakisaka, Ken-Ichi; Kuriyama, Shigeru

This paper proposes a method for retrieving human motion data with concise retrieval rules based on the spatio-temporal features of motion appearance. Our method first converts motion clip into a form of clausal language that represents geometrical relations between body parts and their temporal relationship. A retrieval rule is then learned from the set of manually classified examples using inductive logic programming (ILP). ILP automatically discovers the essential rule in the same clausal form with a user-defined hypothesis-testing procedure. All motions are indexed using this clausal language, and the desired clips are retrieved by subsequence matching using the rule. Such rule-based retrieval offers reasonable performance and the rule can be intuitively edited in the same language form. Consequently, our method enables efficient and flexible search from a large dataset with simple query language.

Robotic follow system and method

DOEpatents

Bruemmer, David J [Idaho Falls, ID; Anderson, Matthew O [Idaho Falls, ID

2007-05-01

Robot platforms, methods, and computer media are disclosed. The robot platform includes perceptors, locomotors, and a system controller, which executes instructions for a robot to follow a target in its environment. The method includes receiving a target bearing and sensing whether the robot is blocked front. If the robot is blocked in front, then the robot's motion is adjusted to avoid the nearest obstacle in front. If the robot is not blocked in front, then the method senses whether the robot is blocked toward the target bearing and if so, sets the rotational direction opposite from the target bearing, and adjusts the rotational velocity and translational velocity. If the robot is not blocked toward the target bearing, then the rotational velocity is adjusted proportional to an angle of the target bearing and the translational velocity is adjusted proportional to a distance to the nearest obstacle in front.

WE-AB-303-01: FEATURED PRESENTATION: A Dual-Detector Phase-Matched Digital Tomosynthesis (DTS) Imaging Scheme Using Aggregated KV and MV Projections for Intra-Treatment Lung Tumor Tracking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Y; Yin, F; Mao, R

2015-06-15

Purpose: To develop a dual-detector phase-matched DTS technique for continuous and fast intra-treatment lung tumor localization. Methods: Tumor localization accuracy of limited-angle DTS imaging is affected by low inter-slice resolution. The dual-detector DTS technique aims to overcome this limitation through combining orthogonally acquired beam’s eye view MV projections and kV projections for intra-treatment DTS reconstruction and localization. To aggregate the kV and MV projections for reconstruction, the MV projections were linearly converted to synthesize corresponding kV projections. To further address the lung motion induced localization errors, this technique uses respiratory phase-matching to match the motion information between on-board DTS andmore » reference DTS to offset the adverse effects of motion blurriness in tumor localization.A study was performed using the CIRS008A lung phantom to simulate different on-board target variation scenarios for localization. The intra-treatment kV and MV acquisition was achieved through the Varian TrueBeam Developer Mode. Four methods were compared for their localization accuracy: 1. the proposed dual-detector phase-matched DTS technique; 2. the single-detector phase-matched DTS technique; 3. the dual-detector 3D-DTS technique without phase-matching; and 4. the single-detector 3D-DTS technique without phase-matching. Results: For scan angles of 2.5°, 5°, 10°, 20° and 30°, the dual-detector phase-matched DTS technique localized the tumor with average(±standard deviations) errors of 0.4±0.3 mm, 0.5±0.3 mm, 0.6±0.2 mm, 0.9±0.4 mm and 1.0±0.3 mm, respectively. The corresponding values of single-detector phase-matched DTS technique were 4.0±2.5 mm, 2.7±1.1 mm, 1.7±1.2 mm, 2.2±0.9 mm and 1.5±0.8 mm, respectively. The values of dual-detector 3D-DTS technique were 6.2±1.7 mm, 6.3±1.2 mm, 5.3±1.3 mm, 2.0±2.2 mm and 1.5±0.5 mm, respectively. And the values of single-detector 3D-DTS technique were 9.7±8.9 mm, 9.8±8.8 mm, 10.0±9.7 mm, 3.9±2.7 mm and 2.2±1.3 mm, respectively. Conclusion: The dual-detector phase-matched DTS technique substantially improves the tumor localization accuracy, which can be applied to real-time intra-treatment lung tumor localization. The research was funded by the National Institutes of Health Grant No. R01-CA184173 and a grant from Varian Medical Systems.« less

Bohm-criterion approximation versus optimal matched solution for a cylindrical probe in radial-motion theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Din, Alif

2016-08-15

The theory of positive-ion collection by a probe immersed in a low-pressure plasma was reviewed and extended by Allen et al. [Proc. Phys. Soc. 70, 297 (1957)]. The numerical computations for cylindrical and spherical probes in a sheath region were presented by F. F. Chen [J. Nucl. Energy C 7, 41 (1965)]. Here, in this paper, the sheath and presheath solutions for a cylindrical probe are matched through a numerical matching procedure to yield “matched” potential profile or “M solution.” The solution based on the Bohm criterion approach “B solution” is discussed for this particular problem. The comparison of cylindricalmore » probe characteristics obtained from the correct potential profile (M solution) and the approximated Bohm-criterion approach are different. This raises questions about the correctness of cylindrical probe theories relying only on the Bohm-criterion approach. Also the comparison between theoretical and experimental ion current characteristics shows that in an argon plasma the ions motion towards the probe is almost radial.« less

Incidence of Changes in Respiration-Induced Tumor Motion and Its Relationship With Respiratory Surrogates During Individual Treatment Fractions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malinowski, Kathleen; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD; McAvoy, Thomas J.

2012-04-01

Purpose: To determine how frequently (1) tumor motion and (2) the spatial relationship between tumor and respiratory surrogate markers change during a treatment fraction in lung and pancreas cancer patients. Methods and Materials: A Cyberknife Synchrony system radiographically localized the tumor and simultaneously tracked three respiratory surrogate markers fixed to a form-fitting vest. Data in 55 lung and 29 pancreas fractions were divided into successive 10-min blocks. Mean tumor positions and tumor position distributions were compared across 10-min blocks of data. Treatment margins were calculated from both 10 and 30 min of data. Partial least squares (PLS) regression models ofmore » tumor positions as a function of external surrogate marker positions were created from the first 10 min of data in each fraction; the incidence of significant PLS model degradation was used to assess changes in the spatial relationship between tumors and surrogate markers. Results: The absolute change in mean tumor position from first to third 10-min blocks was >5 mm in 13% and 7% of lung and pancreas cases, respectively. Superior-inferior and medial-lateral differences in mean tumor position were significantly associated with the lobe of lung. In 61% and 54% of lung and pancreas fractions, respectively, margins calculated from 30 min of data were larger than margins calculated from 10 min of data. The change in treatment margin magnitude for superior-inferior motion was >1 mm in 42% of lung and 45% of pancreas fractions. Significantly increasing tumor position prediction model error (mean {+-} standard deviation rates of change of 1.6 {+-} 2.5 mm per 10 min) over 30 min indicated tumor-surrogate relationship changes in 63% of fractions. Conclusions: Both tumor motion and the relationship between tumor and respiratory surrogate displacements change in most treatment fractions for patient in-room time of 30 min.« less

Incidence of changes in respiration-induced tumor motion and its relationship with respiratory surrogates during individual treatment fractions.

PubMed

Malinowski, Kathleen; McAvoy, Thomas J; George, Rohini; Dietrich, Sonja; D'Souza, Warren D

2012-04-01

To determine how frequently (1) tumor motion and (2) the spatial relationship between tumor and respiratory surrogate markers change during a treatment fraction in lung and pancreas cancer patients. A Cyberknife Synchrony system radiographically localized the tumor and simultaneously tracked three respiratory surrogate markers fixed to a form-fitting vest. Data in 55 lung and 29 pancreas fractions were divided into successive 10-min blocks. Mean tumor positions and tumor position distributions were compared across 10-min blocks of data. Treatment margins were calculated from both 10 and 30 min of data. Partial least squares (PLS) regression models of tumor positions as a function of external surrogate marker positions were created from the first 10 min of data in each fraction; the incidence of significant PLS model degradation was used to assess changes in the spatial relationship between tumors and surrogate markers. The absolute change in mean tumor position from first to third 10-min blocks was >5 mm in 13% and 7% of lung and pancreas cases, respectively. Superior-inferior and medial-lateral differences in mean tumor position were significantly associated with the lobe of lung. In 61% and 54% of lung and pancreas fractions, respectively, margins calculated from 30 min of data were larger than margins calculated from 10 min of data. The change in treatment margin magnitude for superior-inferior motion was >1 mm in 42% of lung and 45% of pancreas fractions. Significantly increasing tumor position prediction model error (mean ± standard deviation rates of change of 1.6 ± 2.5 mm per 10 min) over 30 min indicated tumor-surrogate relationship changes in 63% of fractions. Both tumor motion and the relationship between tumor and respiratory surrogate displacements change in most treatment fractions for patient in-room time of 30 min. Copyright © 2012. Published by Elsevier Inc.

Block versus continuum deformation in the Western United States

USGS Publications Warehouse

King, G.; Oppenheimer, D.; Amelung, F.

1994-01-01

The relative role of block versus continuum deformation of continental lithosphere is a current subject of debate. Continuous deformation is suggested by distributed seismicity at continental plate margins and by cumulative seismic moment sums which yield slip estimates that are less than estimates from plate motion studies. In contrast, block models are favored by geologic studies of displacement in places like Asia. A problem in this debate is a lack of data from which unequivocal conclusions may be reached. In this paper we apply the techniques of study used in regions such as the Alpine-Himalayan belt to an area with a wealth of instrumental data-the Western United States. By comparing plate rates to seismic moment release rates and assuming a typical seismogenic layer thickness of 15 km it appears that since 1850 about 60% of the Pacific-North America motion across the plate boundary in California and Nevada has occurred seismically and 40% aseismically. The San Francisco Bay area shows similar partitioning between seismic and aseismic deformation, and it can be shown that within the seismogenic depth range aseismic deformation is concentrated near the surface and at depth. In some cases this deformation can be located on creeping surface faults, but elsewhere it is spread over a several kilometer wide zone adjacent to the fault. These superficial creeping deformation zones may be responsible for the palaeomagnetic rotations that have been ascribed elsewhere to the surface expression of continuum deformation in the lithosphere. Our results support the dominant role of non-continuum deformation processes with the implication that deformation localization by strain softening must occur in the lower crust and probably the upper mantle. Our conclusions apply only to the regions where the data are good, and even within the Western United States (i.e., the Basin and Range) deformation styles remain poorly resolved. Nonetheless, we maintain that block motion is the deformation style of choice for those continental regions where the data are best. ?? 1994.

Effects of Grip-Force, Contact, and Acceleration Feedback on a Teleoperated Pick-and-Place Task.

PubMed

Khurshid, Rebecca P; Fitter, Naomi T; Fedalei, Elizabeth A; Kuchenbecker, Katherine J

2017-01-01

The multifaceted human sense of touch is fundamental to direct manipulation, but technical challenges prevent most teleoperation systems from providing even a single modality of haptic feedback, such as force feedback. This paper postulates that ungrounded grip-force, fingertip-contact-and-pressure, and high-frequency acceleration haptic feedback will improve human performance of a teleoperated pick-and-place task. Thirty subjects used a teleoperation system consisting of a haptic device worn on the subject's right hand, a remote PR2 humanoid robot, and a Vicon motion capture system to move an object to a target location. Each subject completed the pick-and-place task 10 times under each of the eight haptic conditions obtained by turning on and off grip-force feedback, contact feedback, and acceleration feedback. To understand how object stiffness affects the utility of the feedback, half of the subjects completed the task with a flexible plastic cup, and the others used a rigid plastic block. The results indicate that the addition of grip-force feedback with gain switching enables subjects to hold both the flexible and rigid objects more stably, and it also allowed subjects who manipulated the rigid block to hold the object more delicately and to better control the motion of the remote robot's hand. Contact feedback improved the ability of subjects who manipulated the flexible cup to move the robot's arm in space, but it deteriorated this ability for subjects who manipulated the rigid block. Contact feedback also caused subjects to hold the flexible cup less stably, but the rigid block more securely. Finally, adding acceleration feedback slightly improved the subject's performance when setting the object down, as originally hypothesized; interestingly, it also allowed subjects to feel vibrations produced by the robot's motion, causing them to be more careful when completing the task. This study supports the utility of grip-force and high-frequency acceleration feedback in teleoperation systems and motivates further improvements to fingertip-contact-and-pressure feedback.

Seismicity of the Earth 1900–2010 Middle East and vicinity

USGS Publications Warehouse

Jenkins, Jennifer; Turner, Bethan; Turner, Rebecca; Hayes, Gavin P.; Davies, Sian; Dart, Richard L.; Tarr, Arthur C.; Villaseñor, Antonio; Benz, Harley M.

2013-01-01

No fewer than four major tectonic plates (Arabia, Eurasia, India, and Africa) and one smaller tectonic block (Anatolia) are responsible for seismicity and tectonics in the Middle East and surrounding region. Geologic development of the region is a consequence of a number of first-order plate tectonic processes that include subduction, large-scale transform faulting, compressional mountain building, and crustal extension. In the east, tectonics are dominated by the collision of the India plate with Eurasia, driving the uplift of the Himalaya, Karakorum, Pamir and Hindu Kush mountain ranges. Beneath the Pamir‒Hindu Kush Mountains of northern Afghanistan, earthquakes occur to depths as great as 200 km as a result of remnant lithospheric subduction. Along the western margin of the India plate, relative motions between India and Eurasia are accommodated by strike-slip, reverse, and oblique-slip faulting, resulting in the complex Sulaiman Range fold and thrust belt, and the major translational Chaman Fault in Afghanistan. Off the south coasts of Pakistan and Iran, the Makran trench is the surface expression of active subduction of the Arabia plate beneath Eurasia. Northwest of this subduction zone, collision between the two plates forms the approximately 1,500-km-long fold and thrust belts of the Zagros Mountains, which cross the whole of western Iran and extend into northeastern Iraq. Tectonics in the eastern Mediterranean region are dominated by complex interactions between the Africa, Arabia, and Eurasia plates, and the Anatolia block. Dominant structures in this region include: the Red Sea Rift, the spreading center between the Africa and Arabia plates; the Dead Sea Transform, a major strike-slip fault, also accommodating Africa-Arabia relative motions; the North Anatolia Fault, a right-lateral strike-slip structure in northern Turkey accommodating much of the translational motion of the Anatolia block westwards with respect to Eurasia and Africa; and the Cyprian Arc, a convergent boundary between the Africa plate to the south, and Anatolia Block to the north.

Active crustal deformation of the El Salvador Fault Zone by integrating geodetic, seismological and geological data: application in seismic hazard assessment

NASA Astrophysics Data System (ADS)

Staller, A.; Benito, B.; Martínez-Díaz, J.; Hernández, D.; Hernández-Rey, R.

2013-05-01

El Salvador, Central America, is part of the Chortis block in the northwestern boundary of the Caribbean plate. This block is interacting with a diffuse triple junction point with the Cocos and North American plates. Among the structures that cut the Miocene to Pleistocene volcanic deposits stands out the El Salvador Fault Zone (ESFZ): It is oriented in N90-100E direction, and it is composed of several structural segments that deform Quaternary deposits with right-lateral and oblique slip motions. The ESFZ is seismically active and capable of producing earthquakes such as the February 13, 2001 with Mw 6.6 (Martínez-Díaz et al., 2004), that seriously affected the population, leaving many casualties. This structure plays an important role in the tectonics of the Chortis block, since its motion is directly related to the drift of the Caribbean plate to the east and not with the partitioning of the deformation of the Cocos subduction (here not coupled) (Álvarez-Gómez et al., 2008). Together with the volcanic arc of El Salvador, this zone constitutes a weakness area that allows the motion of forearc block toward the NW. The geometry and the degree of activity of the ESFZ are not studied enough. However their knowledge is essential to understand the seismic hazard associated to this important seismogenic structure. For this reason, since 2007 a GPS dense network was established along the ESFZ (ZFESNet) in order to obtain GPS velocity measurements which are later used to explain the nature of strain accumulation on major faults along the ESFZ. The current work aims at understanding active crustal deformation of the ESFZ through kinematic model. The results provide significant information to be included in a new estimation of seismic hazard taking into account the major structures in ESFZ.

Active crustal deformation of the El Salvador Fault Zone (ESFZ) using GPS data: Implications in seismic hazard assessment

NASA Astrophysics Data System (ADS)

Staller, Alejandra; Benito, Belen; Jesús Martínez-Díaz, José; Hernández, Douglas; Hernández-Rey, Román; Alonso-Henar, Jorge

2014-05-01

El Salvador, Central America, is part of the Chortis block in the northwestern boundary of the Caribbean plate. This block is interacting with a diffuse triple junction point with the Cocos and North American plates. Among the structures that cut the Miocene to Pleistocene volcanic deposits stands out the El Salvador Fault Zone (ESFZ): It is oriented in N90º-100ºE direction, and it is composed of several structural segments that deform Quaternary deposits with right-lateral and oblique slip motions. The ESFZ is seismically active and capable of producing earthquakes such as the February 13, 2001 with Mw 6.6 (Martínez-Díaz et al., 2004), that seriously affected the population, leaving many casualties. This structure plays an important role in the tectonics of the Chortis block, since its motion is directly related to the drift of the Caribbean plate to the east and not with the partitioning of the deformation of the Cocos subduction (here not coupled) (Álvarez-Gómez et al., 2008). Together with the volcanic arc of El Salvador, this zone constitutes a weakness area that allows the motion of forearc block toward the NW. The geometry and the degree of activity of the ESFZ are not studied enough. However their knowledge is essential to understand the seismic hazard associated to this important seismogenic structure. For this reason, since 2007 a GPS dense network was established along the ESFZ (ZFESNet) in order to obtain GPS velocity measurements which are later used to explain the nature of strain accumulation on major faults along the ESFZ. The current work aims at understanding active crustal deformation of the ESFZ through kinematic model. The results provide significant information to be included in a new estimation of seismic hazard taking into account the major structures in ESFZ.

Quadrature errors in the partical derivatives required for the direct recovery of gravity anomalies from satellite observations

NASA Technical Reports Server (NTRS)

Hajela, D. P.

1972-01-01

The equations of motion of a geodetic satellite in the earth's gravitational field expressed by gravity anomalies require the evaluation, amongst others, of the partial derivatives of the disturbing force with respect to individual gravity anomalies. Data are discussed on how anomaly blocks should be subdivided so that the partial derivatives may be numerically evaluated for each subdivision, and then finally meaned to give the value representative of the whole blocks, with accuracies better than 2 to 3 percent for all blocks. The number of subdivisions is large for the blocks nearest to the satellite subpoint and decreases away from it. The actual values of this spherical distance and the actual subdivision of the mean gravity anomaly blocks was determined numerically for 184 15 deg x 15 deg equal area blocks. Satellite heights above the earth of 400 km, 800 km and 1600 km were considered. The computer times for the suggested scheme were compared with alternative solutions.

A generic method for projecting and valuing domestic water uses, application to the Mediterranean basin at the 2050 horizon.

NASA Astrophysics Data System (ADS)

Neverre, Noémie; Dumas, Patrice

2014-05-01

The aim is to be able to assess future domestic water demands in a region with heterogeneous levels of economic development. This work offers an original combination of a quantitative projection of demands (similar to WaterGAP methodology) and an estimation of the marginal benefit of water. This method is applicable to different levels of economic development and usable for large-scale hydroeconomic modelling. The global method consists in building demand functions taking into account the impact of both the price of water and the level of equipment, proxied by economic development, on domestic water demand. Our basis is a 3-blocks inverse demand function: the first block consists of essential water requirements for food and hygiene; the second block matches intermediate needs; and the last block corresponds to additional water consumption, such as outdoor uses, which are the least valued. The volume of the first block is fixed to match recommended basic water requirements from the literature, but we assume that the volume limits of blocks 2 and 3 depend on the level of household equipment and therefore evolve with the level of GDP per capita (structural change), with a saturation. For blocks 1 and 2 we determine the value of water from elasticity, price and quantity data from the literature, using the point-extension method. For block 3, we use a hypothetical zero-cost demand and maximal demand with actual water costs to linearly interpolate the inverse demand function. These functions are calibrated on the 24 countries part of the Mediterranean basin using data from SIMEDD, and are used for the projection and valuation of domestic water demands at the 2050 horizon. They enable to project total water demand, and also the respective shares of the different categories of demand (basic demand, intermediate demand and additional uses). These projections are performed under different combined scenarios of population, GDP and water costs.

A mixed molecular building block strategy for the design of nested polyhedron metal-organic frameworks.

PubMed

Tian, Dan; Chen, Qiang; Li, Yue; Zhang, Ying-Hui; Chang, Ze; Bu, Xian-He

2014-01-13

A mixed molecular building block (MBB) strategy for the synthesis of double-walled cage-based porous metal-organic frameworks (MOFs) is presented. By means of this method, two isostructural porous MOFs built from unprecedented double-walled metal-organic octahedron were obtained by introducing two size-matching C3 -symmetric molecular building blocks with different rigidities. With their unique framework structures, these MOFs provide, to the best of our knowledge, the first examples of double-walled octahedron-based MOFs. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An octahedral shear strain-based measure of SNR for 3D MR elastography

NASA Astrophysics Data System (ADS)

McGarry, M. D. J.; Van Houten, E. E. W.; Perriñez, P. R.; Pattison, A. J.; Weaver, J. B.; Paulsen, K. D.

2011-07-01

A signal-to-noise ratio (SNR) measure based on the octahedral shear strain (the maximum shear strain in any plane for a 3D state of strain) is presented for magnetic resonance elastography (MRE), where motion-based SNR measures are commonly used. The shear strain, γ, is directly related to the shear modulus, μ, through the definition of shear stress, τ = μγ. Therefore, noise in the strain is the important factor in determining the quality of motion data, rather than the noise in the motion. Motion and strain SNR measures were found to be correlated for MRE of gelatin phantoms and the human breast. Analysis of the stiffness distributions of phantoms reconstructed from the measured motion data revealed a threshold for both strain and motion SNR where MRE stiffness estimates match independent mechanical testing. MRE of the feline brain showed significantly less correlation between the two SNR measures. The strain SNR measure had a threshold above which the reconstructed stiffness values were consistent between cases, whereas the motion SNR measure did not provide a useful threshold, primarily due to rigid body motion effects.

Impaired visual recognition of biological motion in schizophrenia.

PubMed

Kim, Jejoong; Doop, Mikisha L; Blake, Randolph; Park, Sohee

2005-09-15

Motion perception deficits have been suggested to be an important feature of schizophrenia but the behavioral consequences of such deficits are unknown. Biological motion refers to the movements generated by living beings. The human visual system rapidly and effortlessly detects and extracts socially relevant information from biological motion. A deficit in biological motion perception may have significant consequences for detecting and interpreting social information. Schizophrenia patients and matched healthy controls were tested on two visual tasks: recognition of human activity portrayed in point-light animations (biological motion task) and a perceptual control task involving detection of a grouped figure against the background noise (global-form task). Both tasks required detection of a global form against background noise but only the biological motion task required the extraction of motion-related information. Schizophrenia patients performed as well as the controls in the global-form task, but were significantly impaired on the biological motion task. In addition, deficits in biological motion perception correlated with impaired social functioning as measured by the Zigler social competence scale [Zigler, E., Levine, J. (1981). Premorbid competence in schizophrenia: what is being measured? Journal of Consulting and Clinical Psychology, 49, 96-105.]. The deficit in biological motion processing, which may be related to the previously documented deficit in global motion processing, could contribute to abnormal social functioning in schizophrenia.

Are Current Physical Match Performance Metrics in Elite Soccer Fit for Purpose or is the Adoption of an Integrated Approach Needed?

PubMed

Bradley, Paul S; Ade, Jack D

2018-01-18

Time-motion analysis is a valuable data-collection technique used to quantify the physical match performance of elite soccer players. For over 40 years researchers have adopted a 'traditional' approach when evaluating match demands by simply reporting the distance covered or time spent along a motion continuum of walking through to sprinting. This methodology quantifies physical metrics in isolation without integrating other factors and this ultimately leads to a one-dimensional insight into match performance. Thus, this commentary proposes a novel 'integrated' approach that focuses on a sensitive physical metric such as high-intensity running but contextualizes this in relation to key tactical activities for each position and collectively for the team. In the example presented, the 'integrated' model clearly unveils the unique high-intensity profile that exists due to distinct tactical roles, rather than one-dimensional 'blind' distances produced by 'traditional' models. Intuitively this innovative concept may aid the coaches understanding of the physical performance in relation to the tactical roles and instructions given to the players. Additionally, it will enable practitioners to more effectively translate match metrics into training and testing protocols. This innovative model may well aid advances in other team sports that incorporate similar intermittent movements with tactical purpose. Evidence of the merits and application of this new concept are needed before the scientific community accepts this model as it may well add complexity to an area that conceivably needs simplicity.

The Shock and Vibration Digest. Volume 17, Number 2

DTIC Science & Technology

1985-02-01

phenomena relative to A computer program has been developed to -.- buildings, bridges, dams, and other struc- simulate the motions of bodies subjected to...1982). (57) Ikushima, T., Honma, T., and Ishiz- uka, H., "Seismic Research on Block-Type (47) Kadle, D.S. and Chwang, A.T., "Hy- HTGR Core ," Nucl...T., "A Seismic Study of High Temperature Gas-Cooled Reactor Core - (48) Yang, C.Y., Chiarito, V., and Dressel, with Block-Type Fuel ; 2nd Rept: An Ana

Seismic analysis and design of bridge abutments considering sliding and rotation

DOT National Transportation Integrated Search

1997-09-15

Current displacement based seismic design of gravity retaining walls utilizes a sliding block idealization, and considers only a translation mode of deformation. Authors update and extend the coupled equations of motion that appear in the literature....

Dynamics of landslide model with time delay and periodic parameter perturbations

NASA Astrophysics Data System (ADS)

Kostić, Srđan; Vasović, Nebojša; Franović, Igor; Jevremović, Dragutin; Mitrinovic, David; Todorović, Kristina

2014-09-01

In present paper, we analyze the dynamics of a single-block model on an inclined slope with Dieterich-Ruina friction law under the variation of two new introduced parameters: time delay Td and initial shear stress μ. It is assumed that this phenomenological model qualitatively simulates the motion along the infinite creeping slope. The introduction of time delay is proposed to mimic the memory effect of the sliding surface and it is generally considered as a function of history of sliding. On the other hand, periodic perturbation of initial shear stress emulates external triggering effect of long-distant earthquakes or some non-natural vibration source. The effects of variation of a single observed parameter, Td or μ, as well as their co-action, are estimated for three different sliding regimes: β < 1, β = 1 and β > 1, where β stands for the ratio of long-term to short-term stress changes. The results of standard local bifurcation analysis indicate the onset of complex dynamics for very low values of time delay. On the other side, numerical approach confirms an additional complexity that was not observed by local analysis, due to the possible effect of global bifurcations. The most complex dynamics is detected for β < 1, with a complete Ruelle-Takens-Newhouse route to chaos under the variation of Td, or the co-action of both parameters Td and μ. These results correspond well with the previous experimental observations on clay and siltstone with low clay fraction. In the same regime, the perturbation of only a single parameter, μ, renders the oscillatory motion of the block. Within the velocity-independent regime, β = 1, the inclusion and variation of Td generates a transition to equilibrium state, whereas the small oscillations of μ induce oscillatory motion with decreasing amplitude. The co-action of both parameters, in the same regime, causes the decrease of block's velocity. As for β > 1, highly-frequent, limit-amplitude oscillations of initial stress give rise to oscillatory motion. Also for β > 1, in case of perturbing only the initial shear stress, with smaller amplitude, velocity of the block changes exponentially fast. If the time delay is introduced, besides the stress perturbation, within the same regime, the co-action of Td (Td < 0.1) and small oscillations of μ induce the onset of deterministic chaos.

Ion Motion Induced Emittance Growth of Matched Electron Beams in Plasma Wakefields.

PubMed

An, Weiming; Lu, Wei; Huang, Chengkun; Xu, Xinlu; Hogan, Mark J; Joshi, Chan; Mori, Warren B

2017-06-16

Plasma-based acceleration is being considered as the basis for building a future linear collider. Nonlinear plasma wakefields have ideal properties for accelerating and focusing electron beams. Preservation of the emittance of nano-Coulomb beams with nanometer scale matched spot sizes in these wakefields remains a critical issue due to ion motion caused by their large space charge forces. We use fully resolved quasistatic particle-in-cell simulations of electron beams in hydrogen and lithium plasmas, including when the accelerated beam has different emittances in the two transverse planes. The projected emittance initially grows and rapidly saturates with a maximum emittance growth of less than 80% in hydrogen and 20% in lithium. The use of overfocused beams is found to dramatically reduce the emittance growth. The underlying physics that leads to the lower than expected emittance growth is elucidated.

Efficient structure from motion on large scenes using UAV with position and pose information

NASA Astrophysics Data System (ADS)

Teng, Xichao; Yu, Qifeng; Shang, Yang; Luo, Jing; Wang, Gang

2018-04-01

In this paper, we exploit prior information from global positioning systems and inertial measurement units to speed up the process of large scene reconstruction from images acquired by Unmanned Aerial Vehicles. We utilize weak pose information and intrinsic parameter to obtain the projection matrix for each view. As compared to unmanned aerial vehicles' flight altitude, topographic relief can usually be ignored, we assume that the scene is flat and use weak perspective camera to get projective transformations between two views. Furthermore, we propose an overlap criterion and select potentially matching view pairs between projective transformed views. A robust global structure from motion method is used for image based reconstruction. Our real world experiments show that the approach is accurate, scalable and computationally efficient. Moreover, projective transformations between views can also be used to eliminate false matching.

Unimpaired perception of social and physical causality, but impaired perception of animacy in high functioning children with autism.

PubMed

Congiu, Sara; Schlottmann, Anne; Ray, Elizabeth

2010-01-01

We investigated perception of social and physical causality and animacy in simple motion events, for high-functioning children with autism (CA = 13, VMA = 9.6). Children matched 14 different animations to pictures showing physical, social or non-causality. In contrast to previous work, children with autism performed at a high level similar to VMA-matched controls, recognizing physical causality in launch and social causality in reaction events. The launch deficit previously found in younger children with autism, possibly related to attentional/verbal difficulties, is apparently overcome with age. Some events involved squares moving non-rigidly, like animals. Children with autism had difficulties recognizing this, extending the biological motion literature. However, animacy prompts amplified their attributions of social causality. Thus children with autism may overcome their animacy perception deficit strategically.

a Robust Method for Stereo Visual Odometry Based on Multiple Euclidean Distance Constraint and Ransac Algorithm

NASA Astrophysics Data System (ADS)

Zhou, Q.; Tong, X.; Liu, S.; Lu, X.; Liu, S.; Chen, P.; Jin, Y.; Xie, H.

2017-07-01

Visual Odometry (VO) is a critical component for planetary robot navigation and safety. It estimates the ego-motion using stereo images frame by frame. Feature points extraction and matching is one of the key steps for robotic motion estimation which largely influences the precision and robustness. In this work, we choose the Oriented FAST and Rotated BRIEF (ORB) features by considering both accuracy and speed issues. For more robustness in challenging environment e.g., rough terrain or planetary surface, this paper presents a robust outliers elimination method based on Euclidean Distance Constraint (EDC) and Random Sample Consensus (RANSAC) algorithm. In the matching process, a set of ORB feature points are extracted from the current left and right synchronous images and the Brute Force (BF) matcher is used to find the correspondences between the two images for the Space Intersection. Then the EDC and RANSAC algorithms are carried out to eliminate mismatches whose distances are beyond a predefined threshold. Similarly, when the left image of the next time matches the feature points with the current left images, the EDC and RANSAC are iteratively performed. After the above mentioned, there are exceptional remaining mismatched points in some cases, for which the third time RANSAC is applied to eliminate the effects of those outliers in the estimation of the ego-motion parameters (Interior Orientation and Exterior Orientation). The proposed approach has been tested on a real-world vehicle dataset and the result benefits from its high robustness.

Numerical Upscaling of Solute Transport in Fractured Porous Media Based on Flow Aligned Blocks

NASA Astrophysics Data System (ADS)

Leube, P.; Nowak, W.; Sanchez-Vila, X.

2013-12-01

High-contrast or fractured-porous media (FPM) pose one of the largest unresolved challenges for simulating large hydrogeological systems. The high contrast in advective transport between fast conduits and low-permeability rock matrix, including complex mass transfer processes, leads to the typical complex characteristics of early bulk arrivals and long tailings. Adequate direct representation of FPM requires enormous numerical resolutions. For large scales, e.g. the catchment scale, and when allowing for uncertainty in the fracture network architecture or in matrix properties, computational costs quickly reach an intractable level. In such cases, multi-scale simulation techniques have become useful tools. They allow decreasing the complexity of models by aggregating and transferring their parameters to coarser scales and so drastically reduce the computational costs. However, these advantages come at a loss of detail and accuracy. In this work, we develop and test a new multi-scale or upscaled modeling approach based on block upscaling. The novelty is that individual blocks are defined by and aligned with the local flow coordinates. We choose a multi-rate mass transfer (MRMT) model to represent the remaining sub-block non-Fickian behavior within these blocks on the coarse scale. To make the scale transition simple and to save computational costs, we capture sub-block features by temporal moments (TM) of block-wise particle arrival times to be matched with the MRMT model. By predicting spatial mass distributions of injected tracers in a synthetic test scenario, our coarse-scale solution matches reasonably well with the corresponding fine-scale reference solution. For predicting higher TM-orders (such as arrival time and effective dispersion), the prediction accuracy steadily decreases. This is compensated to some extent by the MRMT model. If the MRMT model becomes too complex, it loses its effect. We also found that prediction accuracy is sensitive to the choice of the effective dispersion coefficients and on the block resolution. A key advantage of the flow-aligned blocks is that the small-scale velocity field is reproduced quite accurately on the block-scale through their flow alignment. Thus, the block-scale transverse dispersivities remain in the similar magnitude as local ones, and they do not have to represent macroscopic uncertainty. Also, the flow-aligned blocks minimize numerical dispersion when solving the large-scale transport problem.

Matching by linear programming and successive convexification.

PubMed

Jiang, Hao; Drew, Mark S; Li, Ze-Nian

2007-06-01

We present a novel convex programming scheme to solve matching problems, focusing on the challenging problem of matching in a large search range and with cluttered background. Matching is formulated as metric labeling with L1 regularization terms, for which we propose a novel linear programming relaxation method and an efficient successive convexification implementation. The unique feature of the proposed relaxation scheme is that a much smaller set of basis labels is used to represent the original label space. This greatly reduces the size of the searching space. A successive convexification scheme solves the labeling problem in a coarse to fine manner. Importantly, the original cost function is reconvexified at each stage, in the new focus region only, and the focus region is updated so as to refine the searching result. This makes the method well-suited for large label set matching. Experiments demonstrate successful applications of the proposed matching scheme in object detection, motion estimation, and tracking.

8-OH-DPAT suppresses vomiting in the cat elicited by motion, cisplatin or xylazine

NASA Technical Reports Server (NTRS)

Lucot, James B.; Crampton, George H.

1989-01-01

Vomiting was suppressed in cats pretreated with 8-OH-DPAT and then challenged with an emetic stimulus; motion, xylazine or cisplatin. The antiemetic effect is likely due to stimulation of postsynaptic serotonin-1A receptors. The most parsimonious explanation is that it acts at a convergent structure, presumably at or near the vomiting center. If so, 8-OH-DPAT may block emesis elicited by virtually any other stimulus. A supplementary experiment revealed that lorazepam suppressed motion sickness at a dose that produced ataxia, but did not suppress xylazine-induced emesis. These results do not support the possibility that the antiemetic effects of 8-OH-DPAT were the result of anxiolytic activity.

Schematic construction of flanged nanobearings from double-walled carbon nanotubes.

PubMed

Shenai, Prathamesh Mahesh; Zhao, Yang

2010-08-01

The performance of nanobearings constructed from double walled carbon nanotubes is considered to be crucially dependent on the initial rotational speed. Wearless rotation ceases for a nanobearing operating beyond a certain angular velocity. We propose a new design of nanobearings by manipulation of double walled carbon nanotubes leading to a flanged structure which possesses a built-in hindrance to the intertube oscillation without obstructing rotational motion. Through blocking the possible leakage path for rotational kinetic energy to the intertube oscillatory motion, the flanged bearing lowers its dissipative tendency when set into motion. Using molecular dynamics, it is shown that on account of its distinctive structure, the flanged bearing has superior operating characteristics and a broader working domain.

Geo-Referenced Dynamic Pushbroom Stereo Mosaics for 3D and Moving Target Extraction - A New Geometric Approach

DTIC Science & Technology

2009-12-01

facilitating reliable stereo matching, occlusion handling, accurate 3D reconstruction and robust moving target detection . We use the fact that all the...a moving platform, we will have to naturally and effectively handle obvious motion parallax and object occlusions in order to be able to detect ...facilitating reliable stereo matching, occlusion handling, accurate 3D reconstruction and robust moving target detection . Based on the above two

New Constraints on Baja California-North America Relative Plate Motion Since 11 Ma

NASA Astrophysics Data System (ADS)

Bennett, S. E.; Skinner, L. A.; Darin, M. H.; Umhoefer, P. J.; Oskin, M. E.; Dorsey, R. J.

2013-12-01

Tectonic reconstructions of the Pacific-North America (PAC-NAM) plate boundary across the Gulf of California and Salton Trough (GCAST) constrain the controversial magnitude of Baja California microplate-North America (BCM-NAM) relative motion since middle Miocene time. We use estimates of total PAC-NAM relative dextral-oblique motion from the updated global plate-circuit model (Atwater and Stock, 2013; GSA Cordilleran Mtg) to resolve the proportion of this motion on faults east of the BCM. Modern GPS studies and offset of late Miocene cross-gulf geologic tie points both suggest that BCM has never been completely coupled to the Pacific plate. Thus, our preferred GCAST reconstruction uses 93% BCM-PAC coupling from the present back to 6 Ma. We assume BCM-PAC coupling of 60% between 6 and 7 Ma, and 25% between 7 and 11 Ma, to avoid unacceptable overlap of continental crustal blocks between Baja California and the Sierra Madre Occidental (on stable NAM). Using these coupling ratios and PAC-NAM stage Euler poles, we determine the azimuth and velocity of individual points on the BCM in 1 million year increments back to 11 Ma. This procedure accounts for minor clockwise rotation of BCM that occurred during oblique rifting, and shows how total BCM-NAM relative motion increases from north to south due to greater distance from the Euler pole. Finer-scale restoration of tectonic blocks along significant (>1 km offset) faults, across extensional (e.g. pull-apart and half-graben) basins, and by vertical-axis rotation is constrained by local geologic and marine-geophysical datasets and accomplished via the open-source Tectonic Reconstruct ArcGIS tool. We find that restoration across the Gulf of California completely closes marine basins and their terrestrial predecessors between 6 and 9 Ma. Latest Miocene opening of these basins was coincident with a ~10° clockwise azimuthal change from 8 to 6 Ma in PAC-NAM relative motion, as revealed by the global plate circuit model. The coupling ratios used in our reconstruction produce important changes in BCM-NAM relative motion, where a point at the latitude of the Guaymas rift corridor experienced a ~10° clockwise azimuthal change from ~119° to ~129° between 8 and 6 Ma, and a ~27 mm/yr rifting rate increase from ~13 to ~40 mm/yr between 9 and 6 Ma. This increase in obliquity and rate of rifting likely drove localization of plate boundary strain into the North American continent and ultimately formed the Gulf of California. Initiation of these basins ca. 9 Ma requires that the residual ~20 - 40 km of dextral-oblique motion from 9 to 11 Ma occurred immediately offshore or east of the present-day Sonora-Sinaloa shoreline on as-yet undocumented structures. Total preferred BCM-NAM dextral-oblique motion since 11 Ma varies from ~385 km in the southern Gulf of California to ~365 km at the Midriff Islands. These values and the south-north gradient are consistent with recent estimates of ~340 × 40 km of relative dextral plate motion across southern California and the Eastern California Shear Zone. Attempts to restore larger amounts (e.g. 450 - 500 km) of BCM-NAM motion require a higher percent of late Miocene BCM-PAC coupling and result in unacceptable overlap between continental tectonic blocks in western Sonora and Sinaloa and submerged, extended continental crust in the southern Gulf of California.

Channel Estimation and Pilot Design for Massive MIMO Systems with Block-Structured Compressive Sensing

NASA Astrophysics Data System (ADS)

Lv, ZhuoKai; Yang, Tiejun; Zhu, Chunhua

2018-03-01

Through utilizing the technology of compressive sensing (CS), the channel estimation methods can achieve the purpose of reducing pilots and improving spectrum efficiency. The channel estimation and pilot design scheme are explored during the correspondence under the help of block-structured CS in massive MIMO systems. The block coherence property of the aggregate system matrix can be minimized so that the pilot design scheme based on stochastic search is proposed. Moreover, the block sparsity adaptive matching pursuit (BSAMP) algorithm under the common sparsity model is proposed so that the channel estimation can be caught precisely. Simulation results are to be proved the proposed design algorithm with superimposed pilots design and the BSAMP algorithm can provide better channel estimation than existing methods.

3D Tracking of Diatom Motion in Turbulent Flow

NASA Astrophysics Data System (ADS)

Variano, E. A.; Brandt, L.; Sardina, G.; Ardekani, M.; Pujara, N.; Ayers, S.; Du Clos, K.; Karp-Boss, L.; Jumars, P. A.

2016-02-01

We present laboratory measurements of single-celled and chain forming diatom motion in a stirred turbulence tank. The overarching goal is to explore whether diatoms track flow with fidelity (passive tracers) or whether interactions with cell density and shape result in biased trajectories that alter settling velocities. Diatom trajectories are recorded in 3D using a stereoscopic, calibrated tracking tool. Turbulence is created in a novel stirred tank, designed to create motions that match those found in the ocean surface mixed layer at scales less than 10 cm. The data are analyzed for evidence of enhanced particle clustering, an indicator of turbulently altered settling rates

Traveling waves in a spring-block chain sliding down a slope

NASA Astrophysics Data System (ADS)

Morales, J. E.; James, G.; Tonnelier, A.

2017-07-01

Traveling waves are studied in a spring slider-block model. We explicitly construct front waves (kinks) for a piecewise-linear spinodal friction force. Pulse waves are obtained as the matching of two traveling fronts with identical speeds. Explicit formulas are obtained for the wavespeed and the wave form in the anticontinuum limit. The link with localized waves in a Burridge-Knopoff model of an earthquake fault is briefly discussed.

Traveling waves in a spring-block chain sliding down a slope.

PubMed

Morales, J E; James, G; Tonnelier, A

2017-07-01

Traveling waves are studied in a spring slider-block model. We explicitly construct front waves (kinks) for a piecewise-linear spinodal friction force. Pulse waves are obtained as the matching of two traveling fronts with identical speeds. Explicit formulas are obtained for the wavespeed and the wave form in the anticontinuum limit. The link with localized waves in a Burridge-Knopoff model of an earthquake fault is briefly discussed.

SLAMMER: Seismic LAndslide Movement Modeled using Earthquake Records

USGS Publications Warehouse

Jibson, Randall W.; Rathje, Ellen M.; Jibson, Matthew W.; Lee, Yong W.

2013-01-01

This program is designed to facilitate conducting sliding-block analysis (also called permanent-deformation analysis) of slopes in order to estimate slope behavior during earthquakes. The program allows selection from among more than 2,100 strong-motion records from 28 earthquakes and allows users to add their own records to the collection. Any number of earthquake records can be selected using a search interface that selects records based on desired properties. Sliding-block analyses, using any combination of rigid-block (Newmark), decoupled, and fully coupled methods, are then conducted on the selected group of records, and results are compiled in both graphical and tabular form. Simplified methods for conducting each type of analysis are also included.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zawisza, I; Yan, H; Yin, F

Purpose: To assure that tumor motion is within the radiation field during high-dose and high-precision radiosurgery, real-time imaging and surrogate monitoring are employed. These methods are useful in providing real-time tumor/surrogate motion but no future information is available. In order to anticipate future tumor/surrogate motion and track target location precisely, an algorithm is developed and investigated for estimating surrogate motion multiple-steps ahead. Methods: The study utilized a one-dimensional surrogate motion signal divided into three components: (a) training component containing the primary data including the first frame to the beginning of the input subsequence; (b) input subsequence component of the surrogatemore » signal used as input to the prediction algorithm: (c) output subsequence component is the remaining signal used as the known output of the prediction algorithm for validation. The prediction algorithm consists of three major steps: (1) extracting subsequences from training component which best-match the input subsequence according to given criterion; (2) calculating weighting factors from these best-matched subsequence; (3) collecting the proceeding parts of the subsequences and combining them together with assigned weighting factors to form output. The prediction algorithm was examined for several patients, and its performance is assessed based on the correlation between prediction and known output. Results: Respiratory motion data was collected for 20 patients using the RPM system. The output subsequence is the last 50 samples (∼2 seconds) of a surrogate signal, and the input subsequence was 100 (∼3 seconds) frames prior to the output subsequence. Based on the analysis of correlation coefficient between predicted and known output subsequence, the average correlation is 0.9644±0.0394 and 0.9789±0.0239 for equal-weighting and relative-weighting strategies, respectively. Conclusion: Preliminary results indicate that the prediction algorithm is effective in estimating surrogate motion multiple-steps in advance. Relative-weighting method shows better prediction accuracy than equal-weighting method. More parameters of this algorithm are under investigation.« less

Direct Estimation of Structure and Motion from Multiple Frames

DTIC Science & Technology

1990-03-01

sequential frames in an image sequence. As a consequence, the information that can be extracted from a single optical flow field is limited to a snapshot of...researchers have developed techniques that extract motion and structure inform.4tion without computation of the optical flow. Best known are the "direct...operated iteratively on a sequence of images to recover structure. It required feature extraction and matching. Broida and Chellappa [9] suggested the use of

2D/3D Visual Tracker for Rover Mast

NASA Technical Reports Server (NTRS)

Bajracharya, Max; Madison, Richard W.; Nesnas, Issa A.; Bandari, Esfandiar; Kunz, Clayton; Deans, Matt; Bualat, Maria

2006-01-01

A visual-tracker computer program controls an articulated mast on a Mars rover to keep a designated feature (a target) in view while the rover drives toward the target, avoiding obstacles. Several prior visual-tracker programs have been tested on rover platforms; most require very small and well-estimated motion between consecutive image frames a requirement that is not realistic for a rover on rough terrain. The present visual-tracker program is designed to handle large image motions that lead to significant changes in feature geometry and photometry between frames. When a point is selected in one of the images acquired from stereoscopic cameras on the mast, a stereo triangulation algorithm computes a three-dimensional (3D) location for the target. As the rover moves, its body-mounted cameras feed images to a visual-odometry algorithm, which tracks two-dimensional (2D) corner features and computes their old and new 3D locations. The algorithm rejects points, the 3D motions of which are inconsistent with a rigid-world constraint, and then computes the apparent change in the rover pose (i.e., translation and rotation). The mast pan and tilt angles needed to keep the target centered in the field-of-view of the cameras (thereby minimizing the area over which the 2D-tracking algorithm must operate) are computed from the estimated change in the rover pose, the 3D position of the target feature, and a model of kinematics of the mast. If the motion between the consecutive frames is still large (i.e., 3D tracking was unsuccessful), an adaptive view-based matching technique is applied to the new image. This technique uses correlation-based template matching, in which a feature template is scaled by the ratio between the depth in the original template and the depth of pixels in the new image. This is repeated over the entire search window and the best correlation results indicate the appropriate match. The program could be a core for building application programs for systems that require coordination of vision and robotic motion.

Hybrid markerless tracking of complex articulated motion in golf swings.

PubMed

Fung, Sim Kwoh; Sundaraj, Kenneth; Ahamed, Nizam Uddin; Kiang, Lam Chee; Nadarajah, Sivadev; Sahayadhas, Arun; Ali, Md Asraf; Islam, Md Anamul; Palaniappan, Rajkumar

2014-04-01

Sports video tracking is a research topic that has attained increasing attention due to its high commercial potential. A number of sports, including tennis, soccer, gymnastics, running, golf, badminton and cricket have been utilised to display the novel ideas in sports motion tracking. The main challenge associated with this research concerns the extraction of a highly complex articulated motion from a video scene. Our research focuses on the development of a markerless human motion tracking system that tracks the major body parts of an athlete straight from a sports broadcast video. We proposed a hybrid tracking method, which consists of a combination of three algorithms (pyramidal Lucas-Kanade optical flow (LK), normalised correlation-based template matching and background subtraction), to track the golfer's head, body, hands, shoulders, knees and feet during a full swing. We then match, track and map the results onto a 2D articulated human stick model to represent the pose of the golfer over time. Our work was tested using two video broadcasts of a golfer, and we obtained satisfactory results. The current outcomes of this research can play an important role in enhancing the performance of a golfer, provide vital information to sports medicine practitioners by providing technically sound guidance on movements and should assist to diminish the risk of golfing injuries. Copyright © 2013 Elsevier Ltd. All rights reserved.

Wave excited motion of a body floating on water confined between two semi-infinite ice sheets

NASA Astrophysics Data System (ADS)

Ren, K.; Wu, G. X.; Thomas, G. A.

2016-12-01

The wave excited motion of a body floating on water confined between two semi-infinite ice sheets is investigated. The ice sheet is treated as an elastic thin plate and water is treated as an ideal and incompressible fluid. The linearized velocity potential theory is adopted in the frequency domain and problems are solved by the method of matched eigenfunctions expansion. The fluid domain is divided into sub-regions and in each sub-region the velocity potential is expanded into a series of eigenfunctions satisfying the governing equation and the boundary conditions on horizontal planes including the free surface and ice sheets. Matching is conducted at the interfaces of two neighbouring regions to ensure the continuity of the pressure and velocity, and the unknown coefficients in the expressions are obtained as a result. The behaviour of the added mass and damping coefficients of the floating body with the effect of the ice sheets and the excitation force are analysed. They are found to vary oscillatorily with the wave number, which is different from that for a floating body in the open sea. The motion of the body confined between ice sheets is investigated, in particular its resonant behaviour with extremely large motion found to be possible under certain conditions. Standing waves within the polynya are also observed.

Research on sparse feature matching of improved RANSAC algorithm

NASA Astrophysics Data System (ADS)

Kong, Xiangsi; Zhao, Xian

2018-04-01

In this paper, a sparse feature matching method based on modified RANSAC algorithm is proposed to improve the precision and speed. Firstly, the feature points of the images are extracted using the SIFT algorithm. Then, the image pair is matched roughly by generating SIFT feature descriptor. At last, the precision of image matching is optimized by the modified RANSAC algorithm,. The RANSAC algorithm is improved from three aspects: instead of the homography matrix, this paper uses the fundamental matrix generated by the 8 point algorithm as the model; the sample is selected by a random block selecting method, which ensures the uniform distribution and the accuracy; adds sequential probability ratio test(SPRT) on the basis of standard RANSAC, which cut down the overall running time of the algorithm. The experimental results show that this method can not only get higher matching accuracy, but also greatly reduce the computation and improve the matching speed.

Hand gesture recognition by analysis of codons

NASA Astrophysics Data System (ADS)

Ramachandra, Poornima; Shrikhande, Neelima

2007-09-01

The problem of recognizing gestures from images using computers can be approached by closely understanding how the human brain tackles it. A full fledged gesture recognition system will substitute mouse and keyboards completely. Humans can recognize most gestures by looking at the characteristic external shape or the silhouette of the fingers. Many previous techniques to recognize gestures dealt with motion and geometric features of hands. In this thesis gestures are recognized by the Codon-list pattern extracted from the object contour. All edges of an image are described in terms of sequence of Codons. The Codons are defined in terms of the relationship between maxima, minima and zeros of curvature encountered as one traverses the boundary of the object. We have concentrated on a catalog of 24 gesture images from the American Sign Language alphabet (Letter J and Z are ignored as they are represented using motion) [2]. The query image given as an input to the system is analyzed and tested against the Codon-lists, which are shape descriptors for external parts of a hand gesture. We have used the Weighted Frequency Indexing Transform (WFIT) approach which is used in DNA sequence matching for matching the Codon-lists. The matching algorithm consists of two steps: 1) the query sequences are converted to short sequences and are assigned weights and, 2) all the sequences of query gestures are pruned into match and mismatch subsequences by the frequency indexing tree based on the weights of the subsequences. The Codon sequences with the most weight are used to determine the most precise match. Once a match is found, the identified gesture and corresponding interpretation are shown as output.

Self-organizing neural integration of pose-motion features for human action recognition

PubMed Central

Parisi, German I.; Weber, Cornelius; Wermter, Stefan

2015-01-01

The visual recognition of complex, articulated human movements is fundamental for a wide range of artificial systems oriented toward human-robot communication, action classification, and action-driven perception. These challenging tasks may generally involve the processing of a huge amount of visual information and learning-based mechanisms for generalizing a set of training actions and classifying new samples. To operate in natural environments, a crucial property is the efficient and robust recognition of actions, also under noisy conditions caused by, for instance, systematic sensor errors and temporarily occluded persons. Studies of the mammalian visual system and its outperforming ability to process biological motion information suggest separate neural pathways for the distinct processing of pose and motion features at multiple levels and the subsequent integration of these visual cues for action perception. We present a neurobiologically-motivated approach to achieve noise-tolerant action recognition in real time. Our model consists of self-organizing Growing When Required (GWR) networks that obtain progressively generalized representations of sensory inputs and learn inherent spatio-temporal dependencies. During the training, the GWR networks dynamically change their topological structure to better match the input space. We first extract pose and motion features from video sequences and then cluster actions in terms of prototypical pose-motion trajectories. Multi-cue trajectories from matching action frames are subsequently combined to provide action dynamics in the joint feature space. Reported experiments show that our approach outperforms previous results on a dataset of full-body actions captured with a depth sensor, and ranks among the best results for a public benchmark of domestic daily actions. PMID:26106323

Hydrogen transport membranes

DOEpatents

Mundschau, Michael V.

2005-05-31

Composite hydrogen transport membranes, which are used for extraction of hydrogen from gas mixtures are provided. Methods are described for supporting metals and metal alloys which have high hydrogen permeability, but which are either too thin to be self supporting, too weak to resist differential pressures across the membrane, or which become embrittled by hydrogen. Support materials are chosen to be lattice matched to the metals and metal alloys. Preferred metals with high permeability for hydrogen include vanadium, niobium, tantalum, zirconium, palladium, and alloys thereof. Hydrogen-permeable membranes include those in which the pores of a porous support matrix are blocked by hydrogen-permeable metals and metal alloys, those in which the pores of a porous metal matrix are blocked with materials which make the membrane impervious to gases other than hydrogen, and cermets fabricated by sintering powders of metals with powders of lattice-matched ceramic.

Leveraging pattern matching to solve SRAM verification challenges at advanced nodes

NASA Astrophysics Data System (ADS)

Kan, Huan; Huang, Lucas; Yang, Legender; Zou, Elaine; Wan, Qijian; Du, Chunshan; Hu, Xinyi; Liu, Zhengfang; Zhu, Yu; Zhang, Recoo; Huang, Elven; Muirhead, Jonathan

2018-03-01

Memory is a critical component in today's system-on-chip (SoC) designs. Static random-access memory (SRAM) blocks are assembled by combining intellectual property (IP) blocks that come from SRAM libraries developed and certified by the foundries for both functionality and a specific process node. Customers place these SRAM IP in their designs, adjusting as necessary to achieve DRC-clean results. However, any changes a customer makes to these SRAM IP during implementation, whether intentionally or in error, can impact yield and functionality. Physical verification of SRAM has always been a challenge, because these blocks usually contain smaller feature sizes and spacing constraints compared to traditional logic or other layout structures. At advanced nodes, critical dimension becomes smaller and smaller, until there is almost no opportunity to use optical proximity correction (OPC) and lithography to adjust the manufacturing process to mitigate the effects of any changes. The smaller process geometries, reduced supply voltages, increasing process variation, and manufacturing uncertainty mean accurate SRAM physical verification results are not only reaching new levels of difficulty, but also new levels of criticality for design success. In this paper, we explore the use of pattern matching to create an SRAM verification flow that provides both accurate, comprehensive coverage of the required checks and visual output to enable faster, more accurate error debugging. Our results indicate that pattern matching can enable foundries to improve SRAM manufacturing yield, while allowing designers to benefit from SRAM verification kits that can shorten the time to market.

A method of depth image based human action recognition

NASA Astrophysics Data System (ADS)

Li, Pei; Cheng, Wanli

2017-05-01

In this paper, we propose an action recognition algorithm framework based on human skeleton joint information. In order to extract the feature of human motion, we use the information of body posture, speed and acceleration of movement to construct spatial motion feature that can describe and reflect the joint. On the other hand, we use the classical temporal pyramid matching algorithm to construct temporal feature and describe the motion sequence variation from different time scales. Then, we use bag of words to represent these actions, which is to present every action in the histogram by clustering these extracted feature. Finally, we employ Hidden Markov Model to train and test the extracted motion features. In the experimental part, the correctness and effectiveness of the proposed model are comprehensively verified on two well-known datasets.

Strain transformation between tectonic extrusion and crustal thickening in the growth of the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Liu, M.; Li, Y.; Sun, Y.; Shen, X.

2017-12-01

The Indo-Eurasian continental collision since 50 Ma has thickened the crust to raise the Himalayan-Tibetan Plateau and driven lateral extrusion of Asian lithospheric blocks to affect Cenozoic tectonics in central and east Asia. The relative roles of crustal thickening and tectonic extrusion, and the strain partitioning between them over time and space, remain controversial. We have analyzed the strain rates using GPS velocities, and correlated the results with vertical motion derived from precise leveling. We found that tectonic extrusion largely transforms to crustal thickening near the margins of the Tibetan Plateau. Near the NW margin of the Tibetan Plateau, the shear stain transforms to compressive strain, consistent with neotectonic studies that indicate crustal shortening and uplift. Around the SE margin, shear stain largely terminates in the southern Yunnan province of China. The present-day crustal motion in SE Tibetan Plateau can be well explained by gravitational spreading without invoking plate-edge push as envisioned in the tectonic extrusion model. Using data collected from local seismic arrays, we derived receiver functions to image the lithospheric structures across the Tibetan Plateau and the Alashan block to its north and the Ordos block to its east. Our results indicate that the mantle lithosphere of these bounding Asian blocks has not been reworked by Tibetan tectonics; instead they have acted as restrictive walls to the growing Tibetan Plateau. Our finite element modeling shows that crustal deformation along the margins of the Tibetan Plateau are consistent with the notion that the east- and southeastward extrusion of the Tibetan lithosphere is largely confined to the Tibetan Plateau because of the restrictive bounding blocks of the Asian lithosphere. Thus the tectonic impact of the Indo-Eurasian collision on the Cenozoic Asian tectonics may not be as extensive as previously thought.

Euler-Vector Clustering of GPS Velocities Defines Microplate Geometry in Southwest Japan

NASA Astrophysics Data System (ADS)

Savage, J. C.

2018-02-01

I have used Euler-vector clustering to assign 469 GEONET stations in southwest Japan to k clusters (k = 2, 3,..., 9) so that, for any k, the velocities of stations within each cluster are most consistent with rigid-block motion on a sphere. That is, I attempt to explain the raw (i.e., uncorrected for strain accumulation), 1996-2006 velocities of those 469 Global Positioning System stations by rigid motion of k clusters on the surface of a spherical Earth. Because block geometry is maintained as strain accumulates, Euler-vector clustering may better approximate the block geometry than the values of the associated Euler vectors. The microplate solution for each k is constructed by merging contiguous clusters that have closely similar Euler vectors. The best solution consists of three microplates arranged along the Nankaido Trough-Ryukyu Trench between the Amurian and Philippine Sea Plates. One of these microplates, the South Kyushu Microplate (an extension of the Ryukyu forearc into the southeast corner of Kyushu), had previously been identified from paleomagnetic rotations. Relative to ITRF2000 the three microplates rotate at different rates about neighboring poles located close to the northwest corner of Shikoku. The microplate model is identical to that proposed in the block model of Wallace et al. (2009, https://doi.org/10.1130/G2522A.1) except in southernmost Kyushu. On Shikoku and Honshu, but not Kyushu, the microplate model is consistent with that proposed in the block models of Nishimura and Hashimoto (2006, https://doi.org/10.1016/j.tecto.2006.04.017) and Loveless and Meade (2010, https://doi.org/10.1029/2008JB006248) without the low-slip-rate boundaries proposed in the latter.

Phase-linking and the perceived motion during off-vertical axis rotation

PubMed Central

Wood, Scott J.; McCollum, Gin

2010-01-01

Human off-vertical axis rotation (OVAR) in the dark typically produces perceived motion about a cone, the amplitude of which changes as a function of frequency. This perception is commonly attributed to the fact that both the OVAR and the conical motion have a gravity vector that rotates about the subject. Little-known, however, is that this rotating-gravity explanation for perceived conical motion is inconsistent with basic observations about self-motion perception: (a) that the perceived vertical moves toward alignment with the gravito-inertial acceleration (GIA) and (b) that perceived translation arises from perceived linear acceleration, as derived from the portion of the GIA not associated with gravity. Mathematically proved in this article is the fact that during OVAR these properties imply mismatched phase of perceived tilt and translation, in contrast to the common perception of matched phases which correspond to conical motion with pivot at the bottom. This result demonstrates that an additional perceptual rule is required to explain perception in OVAR. This study investigates, both analytically and computationally, the phase relationship between tilt and translation at different stimulus rates—slow (45°/s) and fast (180°/s), and the three-dimensional shape of predicted perceived motion, under different sets of hypotheses about self-motion perception. We propose that for human motion perception, there is a phase-linking of tilt and translation movements to construct a perception of one’s overall motion path. Alternative hypotheses to achieve the phase match were tested with three-dimensional computational models, comparing the output with published experimental reports. The best fit with experimental data was the hypothesis that the phase of perceived translation was linked to perceived tilt, while the perceived tilt was determined by the GIA. This hypothesis successfully predicted the bottom-pivot cone commonly reported and a reduced sense of tilt during fast OVAR. Similar considerations apply to the hilltop illusion often reported during horizontal linear oscillation. Known response properties of central neurons are consistent with this ability to phase-link translation with tilt. In addition, the competing “standard” model was mathematically proved to be unable to predict the bottom-pivot cone regardless of the values used for parameters in the model. PMID:19937069

VizieR Online Data Catalog: NIR proper motion catalogue from UKIDSS-LAS (Smith+, 2014)

NASA Astrophysics Data System (ADS)

Smith, L.; Lucas, P. W.; Burningham, B.; Jones, H. R. A.; Smart, R. L.; Andrei, A. H.; Catalan, S.; Pinfield, D. J.

2015-07-01

We constructed two epoch catalogues for each pointing by matching sources within the pairs of multiframes using the Starlink Tables Infrastructure Library Tool Set (STILTS; Taylor 2006, ASP conf. Ser. 351, 666). We required pairs of sources to be uniquely paired to their closest match within 6-arcsec, and we required the J band magnitudes for the two epochs to agree within 0.5mag, to minimize mismatches. (1 data file).

Present-day Kinematics of Papua New Guinea from GPS campaign measurements

NASA Astrophysics Data System (ADS)

Koulali Idrissi, A.; McClusky, S.; Tregoning, P.

2013-12-01

Papua New Guinea (PNG) is a complex tectonic region located in the convergence zone between the Australian and Pacific Plate. It occupies arguably one of the most tectonically complicated regions of the world, and its geodynamic evolution involves micro-plate rotation, lithospheric rupture forming ocean basins, arc-continent collision, subduction polarity reversal, collisional orogenesis, ophiolite obduction, and exhumation of high-pressure metamorphic (ultramafic) rocks. In this study we present a GPS derived velocity field based on 1993-2008 survey mode observations at 30 GPS sites. We combine our results with previously published GPS velocities to investigate the deformation in northern and northwestern Papua New Guinea. We use an elastic block model to invert the regional GPS velocities as well as earthquake slip vectors for poles of rotation of several micro-plates. The micro-plate block boundary fault geometry is based on geological mapping and regional seismicity. The results show that fault system north of the Highlands fold and thrust belt is the major boundary between the rigid Australian Plate and the north Highlands block, with convergence occurring at rates of between ~ 6 and 11.5 mm/yr. The relative motion across the northern Highlands block increases to the north to ~ 21-24 mm/yr, meaning that the New Guinea trench is likely accumulating elastic strain and confirming that the new Guinea Trench is an active inter-plate boundary. Our results also show, that the north New Guinea Highlands and the Papuan peninsula are best modelled as two blocks separated by a boundary through the Aure Fold belt Belt complex. This block boundary today is accommodating an estimated 4-5 mm/yr dextral motion. Our model also confirms previous results showing that the Ramu-Markham fault accommodates the deformation associated with the Finisterre arc-continent collision. This new GPS velocity field provides fresh insights into the details of the kinematics of the PNG present-day deformation.

Scatter correction using a primary modulator on a clinical angiography C-arm CT system.

PubMed

Bier, Bastian; Berger, Martin; Maier, Andreas; Kachelrieß, Marc; Ritschl, Ludwig; Müller, Kerstin; Choi, Jang-Hwan; Fahrig, Rebecca

2017-09-01

Cone beam computed tomography (CBCT) suffers from a large amount of scatter, resulting in severe scatter artifacts in the reconstructions. Recently, a new scatter correction approach, called improved primary modulator scatter estimation (iPMSE), was introduced. That approach utilizes a primary modulator that is inserted between the X-ray source and the object. This modulation enables estimation of the scatter in the projection domain by optimizing an objective function with respect to the scatter estimate. Up to now the approach has not been implemented on a clinical angiography C-arm CT system. In our work, the iPMSE method is transferred to a clinical C-arm CBCT. Additional processing steps are added in order to compensate for the C-arm scanner motion and the automatic X-ray tube current modulation. These challenges were overcome by establishing a reference modulator database and a block-matching algorithm. Experiments with phantom and experimental in vivo data were performed to evaluate the method. We show that scatter correction using primary modulation is possible on a clinical C-arm CBCT. Scatter artifacts in the reconstructions are reduced with the newly extended method. Compared to a scan with a narrow collimation, our approach showed superior results with an improvement of the contrast and the contrast-to-noise ratio for the phantom experiments. In vivo data are evaluated by comparing the results with a scan with a narrow collimation and with a constant scatter correction approach. Scatter correction using primary modulation is possible on a clinical CBCT by compensating for the scanner motion and the tube current modulation. Scatter artifacts could be reduced in the reconstructions of phantom scans and in experimental in vivo data. © 2017 American Association of Physicists in Medicine.

Which way and how far? Tracking of translation and rotation information for human path integration.

PubMed

Chrastil, Elizabeth R; Sherrill, Katherine R; Hasselmo, Michael E; Stern, Chantal E

2016-10-01

Path integration, the constant updating of the navigator's knowledge of position and orientation during movement, requires both visuospatial knowledge and memory. This study aimed to develop a systems-level understanding of human path integration by examining the basic building blocks of path integration in humans. To achieve this goal, we used functional imaging to examine the neural mechanisms that support the tracking and memory of translational and rotational components of human path integration. Critically, and in contrast to previous studies, we examined movement in translation and rotation tasks with no defined end-point or goal. Navigators accumulated translational and rotational information during virtual self-motion. Activity in hippocampus, retrosplenial cortex (RSC), and parahippocampal cortex (PHC) increased during both translation and rotation encoding, suggesting that these regions track self-motion information during path integration. These results address current questions regarding distance coding in the human brain. By implementing a modified delayed match to sample paradigm, we also examined the encoding and maintenance of path integration signals in working memory. Hippocampus, PHC, and RSC were recruited during successful encoding and maintenance of path integration information, with RSC selective for tasks that required processing heading rotation changes. These data indicate distinct working memory mechanisms for translation and rotation, which are essential for updating neural representations of current location. The results provide evidence that hippocampus, PHC, and RSC flexibly track task-relevant translation and rotation signals for path integration and could form the hub of a more distributed network supporting spatial navigation. Hum Brain Mapp 37:3636-3655, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Ion Motion Induced Emittance Growth of Matched Electron Beams in Plasma Wakefields

DOE Office of Scientific and Technical Information (OSTI.GOV)

An, Weiming; Lu, Wei; Huang, Chengkun

2017-06-14

Plasma-based acceleration is being considered as the basis for building a future linear collider. Nonlinear plasma wakefields have ideal properties for accelerating and focusing electron beams. Preservation of the emittance of nano-Coulomb beams with nanometer scale matched spot sizes in these wakefields remains a critical issue due to ion motion caused by their large space charge forces. We use fully resolved quasistatic particle-in-cell simulations of electron beams in hydrogen and lithium plasmas, including when the accelerated beam has different emittances in the two transverse planes. The projected emittance initially grows and rapidly saturates with a maximum emittance growth of lessmore » than 80% in hydrogen and 20% in lithium. The use of overfocused beams is found to dramatically reduce the emittance growth. In conclusion, the underlying physics that leads to the lower than expected emittance growth is elucidated.« less

Combined Feature Based and Shape Based Visual Tracker for Robot Navigation

NASA Technical Reports Server (NTRS)

Deans, J.; Kunz, C.; Sargent, R.; Park, E.; Pedersen, L.

2005-01-01

We have developed a combined feature based and shape based visual tracking system designed to enable a planetary rover to visually track and servo to specific points chosen by a user with centimeter precision. The feature based tracker uses invariant feature detection and matching across a stereo pair, as well as matching pairs before and after robot movement in order to compute an incremental 6-DOF motion at each tracker update. This tracking method is subject to drift over time, which can be compensated by the shape based method. The shape based tracking method consists of 3D model registration, which recovers 6-DOF motion given sufficient shape and proper initialization. By integrating complementary algorithms, the combined tracker leverages the efficiency and robustness of feature based methods with the precision and accuracy of model registration. In this paper, we present the algorithms and their integration into a combined visual tracking system.

Matching multiple rigid domain decompositions of proteins

PubMed Central

Flynn, Emily; Streinu, Ileana

2017-01-01

We describe efficient methods for consistently coloring and visualizing collections of rigid cluster decompositions obtained from variations of a protein structure, and lay the foundation for more complex setups that may involve different computational and experimental methods. The focus here is on three biological applications: the conceptually simpler problems of visualizing results of dilution and mutation analyses, and the more complex task of matching decompositions of multiple NMR models of the same protein. Implemented into the KINARI web server application, the improved visualization techniques give useful information about protein folding cores, help examining the effect of mutations on protein flexibility and function, and provide insights into the structural motions of PDB proteins solved with solution NMR. These tools have been developed with the goal of improving and validating rigidity analysis as a credible coarse-grained model capturing essential information about a protein’s slow motions near the native state. PMID:28141528

The Risk of Achilles or Biceps Tendon Rupture in New Statin Users: A Propensity Score-Matched Sequential Cohort Study.

PubMed

Spoendlin, Julia; Layton, J Bradley; Mundkur, Mallika; Meier, Christian; Jick, Susan S; Meier, Christoph R

2016-12-01

Case reports and pharmacovigilance data reported cases of tendon ruptures in statin users, but evidence from observational studies is scarce and inconclusive. We aimed to assess the association between new statin use and tendon rupture. We performed a propensity score (PS)-matched sequential cohort study, using data from the Clinical Practice Research Datalink. Patients aged ≥45 years with at least one new statin prescription between 1995 and 2014 were PS-matched within 2-year entry blocks to patients without a statin prescription during the block. We followed patients until they had a recorded Achilles or biceps tendon rupture, completed 5 years of follow-up, or were censored for change in exposure status or another censoring criterion. We calculated hazard ratios (HRs) with 95 % confidence intervals (CIs), applying Cox proportional hazard analyses in the overall cohort (crude and multivariable) and in the PS-matched cohort. We performed subgroup analyses by sex, age, treatment duration, and statin dose. We observed a crude HR of 1.32 (95 % CI 1.21-1.44) in the overall cohort, which attenuated after multivariable adjustment (HR 1.02, 95 % CI 0.92-1.12) and after PS-matching (HR 0.95, 95 % CI 0.84-1.08). Crude HRs were higher in women than in men, but remained around null in both sexes after multivariable adjustment and PS-matching. Subgroup analyses by age, treatment duration, and statin dose revealed null results across all subgroups. The results of this cohort study suggest that statin use does not increase the risk of tendon rupture, irrespective of gender, age, statin dose, or treatment duration.

Retractable barrier strip

DOEpatents

Marts, Donna J.; Barker, Stacey G.; Wowczuk, Andrew; Vellenoweth, Thomas E.

2002-01-01

A portable barrier strip having retractable tire-puncture spikes for puncturing a vehicle tire. The tire-puncture spikes have an armed position for puncturing a tire and a retracted position for not puncturing a tire. The strip comprises a plurality of barrier blocks having the tire-puncture spikes removably disposed in a shaft that is rotatably disposed in each barrier block. The plurality of barrier blocks hare hingedly interconnected by complementary hinges integrally formed into the side of each barrier block which allow the strip to be rolled for easy storage and retrieval, but which prevent irregular or back bending of the strip. The shafts of adjacent barrier blocks are pivotally interconnected via a double hinged universal joint to accommodate irregularities in a roadway surface and to transmit torsional motion of the shaft from block to block. A single flexshaft cable is connected to the shaft of an end block to allow a user to selectively cause the shafts of a plurality of adjacently connected barrier blocks to rotate the tire-puncture spikes to the armed position for puncturing a vehicle tire, and to the retracted position for not puncturing the tire. The flexshaft is provided with a resiliently biased retracting mechanism, and a release latch for allowing the spikes to be quickly retracted after the intended vehicle tire is punctured.

Neotectonic Geomorphology of the Owen Stanley Oblique-slip Fault System, Eastern Papua New Guinea

NASA Astrophysics Data System (ADS)

Watson, L.; Mann, P.; Taylor, F.

2003-12-01

Previous GPS studies have shown that the Australia-Woodlark plate boundary bisects the Papuan Peninsula of Papua New Guinea and that interplate motion along the boundary varies from about 19 mm/yr of orthogonal opening in the area of the western Woodlark spreading center and D'Entrecasteaux Islands, to about 12 mm/yr of highly oblique opening in the central part of the peninsula, to about 10 mm/yr of transpressional motion on the western part of the peninsula. We have compiled a GIS database for the peninsula that includes a digital elevation model, geologic map, LANDSAT and radar imagery, and earthquake focal mechanisms. This combined data set demonstrates the regional importance of the 600-km-long Owen Stanley fault system (OSFS) in accommodating interplate motion and controlling the geomorphology and geologic exposures of the peninsula. The OSFS originated as a NE-dipping, reactivated Oligocene-Early Miocene age ophiolitic suture zone between an Australian continental margin and the Melanesian arc system. Pliocene to recent motion on the plate boundary has reactivated motion on the former NE-dipping thrust fault either as a NE-dipping normal fault in the eastern area or as a more vertical strike-slip fault in the western area. The broadly arcuate shape of the OSFS is probably an inherited feature from the original thrust fault. Faults in the eastern area (east of 148° E) exhibit characteristics expected for normal and oblique slip faults including: discontinuous fault traces bounding an upthrown highland block and a downthrown coastal plain or submarine block, transfer faults parallel to the opening direction, scarps facing to both the northeast and southwest, and spatial association with recent volcanism. Faults in the western area (west of 148° E) exibit characteristics expected for left-lateral strike-slip faults including: linear and continuous fault trace commonly confined to a deep, intermontane valley and sinistral offsets and deflections of rivers and streams by 0.5 to 1.2 km. The northern edge of the OSFS merges with the Ramu-Markham strike-slip fault near Lae. SW tilting of the footwall block (Papuan Peninsula) is responsible for the asymmetrical topographic profile of the peninsula and drowned topography along the southern coast of the peninsula.

Three-dimensional modeling of pull-apart basins: implications for the tectonics of the Dead Sea Basin

USGS Publications Warehouse

Katzman, Rafael; ten Brink, Uri S.; Lin, Jian

1995-01-01

We model the three-dimensional (3-D) crustal deformation in a deep pull-apart basin as a result of relative plate motion along a transform system and compare the results to the tectonics of the Dead Sea Basin. The brittle upper crust is modeled by a boundary element technique as an elastic block, broken by two en echelon semi-infinite vertical faults. The deformation is caused by a horizontal displacement that is imposed everywhere at the bottom of the block except in a stress-free “shear zone” in the vicinity of the fault zone. The bottom displacement represents the regional relative plate motion. Results show that the basin deformation depends critically on the width of the shear zone and on the amount of overlap between basin-bounding faults. As the width of the shear zone increases, the depth of the basin decreases, the rotation around a vertical axis near the fault tips decreases, and the basin shape (the distribution of subsidence normalized by the maximum subsidence) becomes broader. In contrast, two-dimensional plane stress modeling predicts a basin shape that is independent of the width of the shear zone. Our models also predict full-graben profiles within the overlapped region between bounding faults and half-graben shapes elsewhere. Increasing overlap also decreases uplift near the fault tips and rotation of blocks within the basin. We suggest that the observed structure of the Dead Sea Basin can be described by a 3-D model having a large overlap (more than 30 km) that probably increased as the basin evolved as a result of a stable shear motion that was distributed laterally over 20 to 40 km.

Slope-scale dynamic states of rockfalls

NASA Astrophysics Data System (ADS)

Agliardi, F.; Crosta, G. B.

2009-04-01

Rockfalls are common earth surface phenomena characterised by complex dynamics at the slope scale, depending on local block kinematics and slope geometry. We investigated the nature of this slope-scale dynamics by parametric 3D numerical modelling of rockfalls over synthetic slopes with different inclination, roughness and spatial resolution. Simulations were performed through an original code specifically designed for rockfall modeling, incorporating kinematic and hybrid algorithms with different damping functions available to model local energy loss by impact and pure rolling. Modelling results in terms of average velocity profiles suggest that three dynamic regimes (i.e. decelerating, steady-state and accelerating), previously recognized in the literature through laboratory experiments on granular flows, can set up at the slope scale depending on slope average inclination and roughness. Sharp changes in rock fall kinematics, including motion type and lateral dispersion of trajectories, are associated to the transition among different regimes. Associated threshold conditions, portrayed in "phase diagrams" as slope-roughness critical lines, were analysed depending on block size, impact/rebound angles, velocity and energy, and model spatial resolution. Motion in regime B (i.e. steady state) is governed by a slope-scale "viscous friction" with average velocity linearly related to the sine of slope inclination. This suggest an analogy between rockfall motion in regime B and newtonian flow, whereas in regime C (i.e. accelerating) an analogy with a dilatant flow was observed. Thus, although local behavior of single falling blocks is well described by rigid body dynamics, the slope scale dynamics of rockfalls seem to statistically approach that of granular media. Possible outcomes of these findings include a discussion of the transition from rockfall to granular flow, the evaluation of the reliability of predictive models, and the implementation of criteria for a preliminary evaluation of hazard assessment and countermeasure planning.

NASA Tech Briefs, July 2012

NASA Technical Reports Server (NTRS)

2012-01-01

Topics covered include: Instrument Suite for Vertical Characterization of the Ionosphere-Thermosphere System; Terahertz Radiation Heterodyne Detector Using Two-Dimensional Electron Gas in a GaN Heterostructure; Pattern Recognition Algorithm for High-Sensitivity Odorant Detection in Unknown Environments; Determining Performance Acceptability of Electrochemical Oxygen Sensors; Versatile Controller for Infrared Lamp and Heater Arrays; High-Speed Scanning Interferometer Using CMOS Image Sensor and FPGA Based on Multifrequency Phase-Tracking Detection; Ultra-Low-Power MEMS Selective Gas Sensors; Compact Receiver Front Ends for Submillimeter-Wave Applications; Dynamically Reconfigurable Systolic Array Accelerator; Blocking Losses With a Photon Counter; Motion-Capture-Enabled Software for Gestural Control of 3D Mod; Orbit Software Suite; CoNNeCT Baseband Processor Module Boot Code SoftWare (BCSW); Trajectory Software With Upper Atmosphere Model; ALSSAT Version 6.0; Employing a Grinding Technology to Assess the Microbial Density for Encapsulated Organisms; Demonstration of Minimally Machined Honeycomb Silicon Carbide Mirrors; Polyimide Aerogel Thin Films; Nanoengineered Thermal Materials Based on Carbon Nanotube Array Composites; Composite Laminate With Coefficient of Thermal Expansion Matching D263 Glass; Robust Tensioned Kevlar Suspension Design; Focal Plane Alignment Utilizing Optical CMM; Purifying, Separating, and Concentrating Cells From a Sample Low in Biomass; Virtual Ultrasound Guidance for Inexperienced Operators; Beat-to-Beat Blood Pressure Monitor; Non-Contact Conductivity Measurement for Automated Sample Processing Systems; An MSK Radar Waveform; Telescope Alignment From Sparsely Sampled Wavefront Measurements Over Pupil Subapertures; Method to Remove Particulate Matter from Dusty Gases at Low Pressures; Terahertz Quantum Cascade Laser With Efficient Coupling and Beam Profile; Measurement Via Optical Near-Nulling and Subaperture Stitching; 885-nm Pumped Ceramic Nd:YAG Master Oscillator Power Amplifier Laser System; Airborne Hyperspectral Imaging System; Heat Shield Employing Cured Thermal Protection Material Blocks Bonded in a Large-Cell Honeycomb Matrix; and Asymmetric Supercapacitor for Long-Duration Power Storage.

Architectures and algorithms for digital image processing; Proceedings of the Meeting, Cannes, France, December 5, 6, 1985

NASA Technical Reports Server (NTRS)

Duff, Michael J. B. (Editor); Siegel, Howard J. (Editor); Corbett, Francis J. (Editor)

1986-01-01

The conference presents papers on the architectures, algorithms, and applications of image processing. Particular attention is given to a very large scale integration system for image reconstruction from projections, a prebuffer algorithm for instant display of volume data, and an adaptive image sequence filtering scheme based on motion detection. Papers are also presented on a simple, direct practical method of sensing local motion and analyzing local optical flow, image matching techniques, and an automated biological dosimetry system.

Initial Assessment of Human Performance Using the Gaiter Interaction Technique to Control Locomotion in Fully Immersive Virtual Environments

DTIC Science & Technology

2004-06-30

virtual space, as well as to match specific attributes of natural locomotion, such as perceived velocity and caloric expenditure . Moreover, the...wide range of postural motions (e.g., crouching, jumping , and bending to look around objects) with gestural stepping motions. The attributes of in...approximately 8 ¥ 8 ¥ 8 ft. The harness itself was an initial design made out of PVC pipe at the waist and above the head, with rope connecting the

Erosional Reduction of an Orogenic Wedge: Structural Response to Neogene Climate Change within the St. Elias Orogen, Alaska

NASA Astrophysics Data System (ADS)

Berger, A. L.; Spotila, J. A.; Chapman, J. B.; Pavlis, T. L.; Enkelmann, E.; Buscher, J. T.

2007-12-01

The kinematics and architecture of orogenic systems may be heavily influenced by climate, but little research has focused on the long term effects of glacial erosion on orogenesis. Apatite and zircon (U-Th)/He thermochronometry on >75 bedrock samples across the St. Elias orogen, one of the best examples of a glaciated orogenic wedge, is the basis for a new kinematic model and demonstrates an association between glacial denudation and orogenic architecture. The spatial pattern of low temperature cooling indicates that exhumation and deformation are focused within a thin-skinned fold and thrust belt on the windward flank, whereas the leeward flank of the orogen functions as a deformational backstop. A previously unrecognized structure beneath the Bagley ice field must separate these domains with south-side-up motion. We propose this structure is a backthrust making the orogen doubly-vergent. Suggestive of accelerated backthrust motion in response to climate change, cooling rates within the hanging wall block and across the entire windward flank of the orogen accelerated ten-fold coeval with enhanced glaciation. As backthrust motion increased, glacial unroofing also coincided with a regional shift in deformation away from prominent forethrusts including the North American-Yakutat terrane suture (Chugach St. Elias fault) and the seaward deformation front (Pamplona zone). Across the windward flank of the orogen, exhumation, at rates of up to 5 mm/yr, is focused within a narrow zone, where the glacial equilibrium line altitude (ELA) intersects the orogenic wedge. This zone of rapid exhumation, not present prior to the onset of enhanced glaciation, cuts across the structural trend of the orogen and is more narrowly focused than orographic precipitation. Accelerated denudation at the ELA thus appears to have redistributed strain along a series of forethrusts that lie at the zone of heaviest glacial flux, while the backthrust progressively truncates the southward-vergent forethrusts. In a cause and effect response, the expansion of glaciers therefore appears to have resulted in a narrowing of the orogenic wedge due to increased backthrust motion and a landward propagation of deformation in order to preserve topographic slope. This focusing of long- term glacial erosion and deformation at the ELA matches predictions from analytical models of orogenic wedges (i.e. Tomkin and Braun, 2002) and implies a high degree of coupling between climate and tectonics in this glacially-dominated orogen.

Radial polar histogram: obstacle avoidance and path planning for robotic cognition and motion control

NASA Astrophysics Data System (ADS)

Wang, Po-Jen; Keyawa, Nicholas R.; Euler, Craig

2012-01-01

In order to achieve highly accurate motion control and path planning for a mobile robot, an obstacle avoidance algorithm that provided a desired instantaneous turning radius and velocity was generated. This type of obstacle avoidance algorithm, which has been implemented in California State University Northridge's Intelligent Ground Vehicle (IGV), is known as Radial Polar Histogram (RPH). The RPH algorithm utilizes raw data in the form of a polar histogram that is read from a Laser Range Finder (LRF) and a camera. A desired open block is determined from the raw data utilizing a navigational heading and an elliptical approximation. The left and right most radii are determined from the calculated edges of the open block and provide the range of possible radial paths the IGV can travel through. In addition, the calculated obstacle edge positions allow the IGV to recognize complex obstacle arrangements and to slow down accordingly. A radial path optimization function calculates the best radial path between the left and right most radii and is sent to motion control for speed determination. Overall, the RPH algorithm allows the IGV to autonomously travel at average speeds of 3mph while avoiding all obstacles, with a processing time of approximately 10ms.

Forced pitch motion of wind turbines

NASA Astrophysics Data System (ADS)

Leble, V.; Barakos, G.

2016-09-01

The possibility of a wind turbine entering vortex ring state during pitching oscillations is explored in this paper. The aerodynamic performance of the rotor was computed using the Helicopter Multi-Block flow solver. This code solves the Navier-Stokes equations in integral form using the arbitrary Lagrangian-Eulerian formulation for time-dependent domains with moving boundaries. A 10-MW wind turbine was put to perform yawing and pitching oscillations suggesting the partial vortex ring state during pitching motion. The results also show the strong effect of the frequency and amplitude of oscillations on the wind turbine performance.

Assessment of Simulated Ground Motions in Earthquake Engineering Practice: A Case Study for Duzce (Turkey)

NASA Astrophysics Data System (ADS)

Karimzadeh, Shaghayegh; Askan, Aysegul; Yakut, Ahmet

2017-09-01

Simulated ground motions can be used in structural and earthquake engineering practice as an alternative to or to augment the real ground motion data sets. Common engineering applications of simulated motions are linear and nonlinear time history analyses of building structures, where full acceleration records are necessary. Before using simulated ground motions in such applications, it is important to assess those in terms of their frequency and amplitude content as well as their match with the corresponding real records. In this study, a framework is outlined for assessment of simulated ground motions in terms of their use in structural engineering. Misfit criteria are determined for both ground motion parameters and structural response by comparing the simulated values against the corresponding real values. For this purpose, as a case study, the 12 November 1999 Duzce earthquake is simulated using stochastic finite-fault methodology. Simulated records are employed for time history analyses of frame models of typical residential buildings. Next, the relationships between ground motion misfits and structural response misfits are studied. Results show that the seismological misfits around the fundamental period of selected buildings determine the accuracy of the simulated responses in terms of their agreement with the observed responses.

Incremental Dynamic Analysis of Koyna Dam under Repeated Ground Motions

NASA Astrophysics Data System (ADS)

Zainab Nik Azizan, Nik; Majid, Taksiah A.; Nazri, Fadzli Mohamed; Maity, Damodar; Abdullah, Junaidah

2018-03-01

This paper discovers the incremental dynamic analysis (IDA) of concrete gravity dam under single and repeated earthquake loadings to identify the limit state of the dam. Seven ground motions with horizontal and vertical direction as seismic input considered in the nonlinear dynamic analysis based on the real repeated earthquake in the worldwide. All the ground motions convert to respond spectrum and scaled according to the developed elastic respond spectrum in order to match the characteristic of the ground motion to the soil type. The scaled was depends on the fundamental period, T1 of the dam. The Koyna dam has been selected as a case study for the purpose of the analysis by assuming that no sliding and rigid foundation, has been estimated. IDA curves for Koyna dam developed for single and repeated ground motions and the performance level of the dam identifies. The IDA curve of repeated ground motion shown stiffer rather than single ground motion. The ultimate state displacement for a single event is 45.59mm and decreased to 39.33mm under repeated events which are decreased about 14%. This showed that the performance level of the dam based on seismic loadings depend on ground motion pattern.

Edge-Driven Block Rotations Interpreted From New GPS Results: Papua New Guinea

NASA Astrophysics Data System (ADS)

Wallace, L.

2001-12-01

An ongoing discussion in plate tectonics involves whether microplate motions are driven by plate edge forces or by flow at the base of the lithosphere. We present results from a GPS network of 40 sites spanning much of the mainland of Papua New Guinea (PNG). Most of the sites are concentrated in the region of the active Finisterre arc-continent collision and have been observed on multiple campaigns from 1993-2001. Significant portions of the Ramu-Markham fault are locked, which has implications for seismic hazard assessment in the Markham Valley region. Additionally, we find that out-of-sequence thrusting is important in emplacement of the Finisterre arc terrane onto the PNG mainland. Site velocities derived from these GPS data have helped to delineate the major tectonic blocks in the region. We model site velocities by simultaneously dealing with rigid block rotation and elastic strain. We find that the mainland of PNG consists of four distinct tectonic plates: the Australian, South Bismarck and Woodlark plates (in agreement with previous studies), and a previously unrecognized New Guinea Highlands plate. The relative rotation poles for at least two of these plate pairs plot on their respective boundaries, indicating that microplate motion in PNG may be dominantly edge-driven, as predicted for this region by Schouten and Benes (1993).

Earthquake nucleation in a stochastic fault model of globally coupled units with interaction delays

NASA Astrophysics Data System (ADS)

Vasović, Nebojša; Kostić, Srđan; Franović, Igor; Todorović, Kristina

2016-09-01

In present paper we analyze dynamics of fault motion by considering delayed interaction of 100 all-to-all coupled blocks with rate-dependent friction law in presence of random seismic noise. Such a model sufficiently well describes a real fault motion, whose prevailing stochastic nature is implied by surrogate data analysis of available GPS measurements of active fault movement. Interaction of blocks in an analyzed model is studied as a function of time delay, observed both for dynamics of individual faults and phenomenological models. Analyzed model is examined as a system of all-to-all coupled blocks according to typical assumption of compound faults as complex of globally coupled segments. We apply numerical methods to show that there are local bifurcations from equilibrium state to periodic oscillations, with an occurrence of irregular aperiodic behavior when initial conditions are set away from the equilibrium point. Such a behavior indicates a possible existence of a bi-stable dynamical regime, due to effect of the introduced seismic noise or the existence of global attractor. The latter assumption is additionally confirmed by analyzing the corresponding mean-field approximated model. In this bi-stable regime, distribution of event magnitudes follows Gutenberg-Richter power law with satisfying statistical accuracy, including the b-value within the real observed range.

Estimating material viscoelastic properties based on surface wave measurements: A comparison of techniques and modeling assumptions

PubMed Central

Royston, Thomas J.; Dai, Zoujun; Chaunsali, Rajesh; Liu, Yifei; Peng, Ying; Magin, Richard L.

2011-01-01

Previous studies of the first author and others have focused on low audible frequency (<1 kHz) shear and surface wave motion in and on a viscoelastic material comprised of or representative of soft biological tissue. A specific case considered has been surface (Rayleigh) wave motion caused by a circular disk located on the surface and oscillating normal to it. Different approaches to identifying the type and coefficients of a viscoelastic model of the material based on these measurements have been proposed. One approach has been to optimize coefficients in an assumed viscoelastic model type to match measurements of the frequency-dependent Rayleigh wave speed. Another approach has been to optimize coefficients in an assumed viscoelastic model type to match the complex-valued frequency response function (FRF) between the excitation location and points at known radial distances from it. In the present article, the relative merits of these approaches are explored theoretically, computationally, and experimentally. It is concluded that matching the complex-valued FRF may provide a better estimate of the viscoelastic model type and parameter values; though, as the studies herein show, there are inherent limitations to identifying viscoelastic properties based on surface wave measurements. PMID:22225067

RADIO-ACTIVE TRANSDUCER

DOEpatents

Wanetick, S.

1962-03-01

ABS>ure the change in velocity of a moving object. The transducer includes a radioactive source having a collimated beam of radioactive particles, a shield which can block the passage of the radioactive beam, and a scintillation detector to measure the number of radioactive particles in the beam which are not blocked by the shield. The shield is operatively placed across the radioactive beam so that any motion normal to the beam will cause the shield to move in the opposite direction thereby allowing more radioactive particles to reach the detector. The number of particles detected indicates the acceleration. (AEC)

Internal graphite moderator forces study, C and K Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooley, D.E.

1963-10-28

The purpose of this study was to determine the maximum forces that can be imposed by the graphite moderator on prospective VSR channel sleeves. In order to do this, both the origins and modes of transmission of the forces were determined. Forces in the moderator stack that are capable of acting on a block or group of blocks may originate from any of the following primary effects: Contraction of graphite due to irradiation; thermal expansion of graphite; frictional resistance to motion; resistance from keys; gravity; and other.

Real-Time Tracking of Implanted Markers During Radiation Treatment by Use of Simultaneous kV and MV Imaging

DTIC Science & Technology

2009-03-01

the MV–kV correlation method by sinusoidally moving a block of solid water (measuring 5 × 5× 10 cm3) containing three embedded BB metallic markers (3 mm...in diameter). A 4D motion platform (Washington University, St Louis, MO) holding the block of solid water (figure 1) was programmed to produce the...Varian Medical Systems, Palo Alto, CA). The SS-IMRT plans were delivered to either the moving pelvic phantom or the cube of solid water attached to the

Motion compensation via redundant-wavelet multihypothesis.

PubMed

Fowler, James E; Cui, Suxia; Wang, Yonghui

2006-10-01

Multihypothesis motion compensation has been widely used in video coding with previous attention focused on techniques employing predictions that are diverse spatially or temporally. In this paper, the multihypothesis concept is extended into the transform domain by using a redundant wavelet transform to produce multiple predictions that are diverse in transform phase. The corresponding multiple-phase inverse transform implicitly combines the phase-diverse predictions into a single spatial-domain prediction for motion compensation. The performance advantage of this redundant-wavelet-multihypothesis approach is investigated analytically, invoking the fact that the multiple-phase inverse involves a projection that significantly reduces the power of a dense-motion residual modeled as additive noise. The analysis shows that redundant-wavelet multihypothesis is capable of up to a 7-dB reduction in prediction-residual variance over an equivalent single-phase, single-hypothesis approach. Experimental results substantiate the performance advantage for a block-based implementation.

Exploitation of Ubiquitous Wi-Fi Devices as Building Blocks for Improvised Motion Detection Systems.

PubMed

Soldovieri, Francesco; Gennarelli, Gianluca

2016-02-27

This article deals with a feasibility study on the detection of human movements in indoor scenarios based on radio signal strength variations. The sensing principle exploits the fact that the human body interacts with wireless signals, introducing variations of the radiowave fields due to shadowing and multipath phenomena. As a result, human motion can be inferred from fluctuations of radiowave power collected by a receiving terminal. In this paper, we investigate the potentialities of widely available wireless communication devices in order to develop an improvised motion detection system (IMDS). Experimental tests are performed in an indoor environment by using a smartphone as a Wi-Fi access point and a laptop with dedicated software as a receiver. Simple detection strategies tailored for real-time operation are implemented to process the received signal strength measurements. The achieved results confirm the potentialities of the simple system here proposed to reliably detect human motion in operational conditions.

14 CFR 33.97 - Thrust reversers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.97 Thrust reversers. (a) If the... this subpart must be run with the reverser installed. In complying with this section, the power control... regimes of control operations are incorporated necessitating scheduling of the power-control lever motion...

14 CFR 33.97 - Thrust reversers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.97 Thrust reversers. (a) If the... this subpart must be run with the reverser installed. In complying with this section, the power control... regimes of control operations are incorporated necessitating scheduling of the power-control lever motion...

Impulse Pump

DTIC Science & Technology

2016-06-17

APPLICATIONS [0002] None. BACKGROUND OF THE INVENTION (1) Field of the Invention [0003] The present invention relates to an impulse pump for generating...impulse pump 15. The sleeve bearings 98 are affixed to the head block 90 to ease axial motion while the plunger 72 is under torsional loads. [0041

Newly velocity field of Sulawesi Island from GPS observation

NASA Astrophysics Data System (ADS)

Sarsito, D. A.; Susilo, Simons, W. J. F.; Abidin, H. Z.; Sapiie, B.; Triyoso, W.; Andreas, H.

2017-07-01

Sulawesi microplate Island is located at famous triple junction area of the Eurasian, India-Australian, and Philippine Sea plates. Under the influence of the northward moving Australian plate and the westward motion of the Philippine plate, the island at Eastern part of Indonesia is collide and with the Eurasian plate and Sunda Block. Those recent microplate tectonic motions can be quantitatively determine by GNSS-GPS measurement. We use combine GNSS-GPS observation types (campaign type and continuous type) from 1997 to 2015 to derive newly velocity field of the area. Several strategies are applied and tested to get the optimum result, and finally we choose regional strategy to reduce error propagation contribution from global multi baseline processing using GAMIT/GLOBK 10.5. Velocity field are analyzed in global reference frame ITRF 2008 and local reference frame by fixing with respect alternatively to Eurasian plate - Sunda block, India-Australian plate and Philippine Sea plates. Newly results show dense distribution of velocity field. This information is useful for tectonic deformation studying in geospatial era.