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.

Distance Estimation Using Handheld Devices

DTIC Science & Technology

2013-06-01

each and all centered in the pin that marks the location of the device. ................................47 Figure 21. Form interface where the UFO ...SIFT Scale-invariant feature transform SURF Speed up Robust Features SAD Sum of Absolute Distance UFOs Untrained Forward Observers WHATWG Web...Forward Observers ( UFOs ) to make a successful call for fire. This chapter presents the solution from different aspects and is organized as follows

On analyzing colour constancy approach for improving SURF detector performance

NASA Astrophysics Data System (ADS)

Zulkiey, Mohd Asyraf; Zaki, Wan Mimi Diyana Wan; Hussain, Aini; Mustafa, Mohd. Marzuki

2012-04-01

Robust key point detector plays a crucial role in obtaining a good tracking feature. The main challenge in outdoor tracking is the illumination change due to various reasons such as weather fluctuation and occlusion. This paper approaches the illumination change problem by transforming the input image through colour constancy algorithm before applying the SURF detector. Masked grey world approach is chosen because of its ability to perform well under local as well as global illumination change. Every image is transformed to imitate the canonical illuminant and Gaussian distribution is used to model the global change. The simulation results show that the average number of detected key points have increased by 69.92%. Moreover, the average of improved performance cases far out weight the degradation case where the former is improved by 215.23%. The approach is suitable for tracking implementation where sudden illumination occurs frequently and robust key point detection is needed.

Real-time UAV trajectory generation using feature points matching between video image sequences

NASA Astrophysics Data System (ADS)

Byun, Younggi; Song, Jeongheon; Han, Dongyeob

2017-09-01

Unmanned aerial vehicles (UAVs), equipped with navigation systems and video capability, are currently being deployed for intelligence, reconnaissance and surveillance mission. In this paper, we present a systematic approach for the generation of UAV trajectory using a video image matching system based on SURF (Speeded up Robust Feature) and Preemptive RANSAC (Random Sample Consensus). Video image matching to find matching points is one of the most important steps for the accurate generation of UAV trajectory (sequence of poses in 3D space). We used the SURF algorithm to find the matching points between video image sequences, and removed mismatching by using the Preemptive RANSAC which divides all matching points to outliers and inliers. The inliers are only used to determine the epipolar geometry for estimating the relative pose (rotation and translation) between image sequences. Experimental results from simulated video image sequences showed that our approach has a good potential to be applied to the automatic geo-localization of the UAVs system

Military personnel recognition system using texture, colour, and SURF features

NASA Astrophysics Data System (ADS)

Irhebhude, Martins E.; Edirisinghe, Eran A.

2014-06-01

This paper presents an automatic, machine vision based, military personnel identification and classification system. Classification is done using a Support Vector Machine (SVM) on sets of Army, Air Force and Navy camouflage uniform personnel datasets. In the proposed system, the arm of service of personnel is recognised by the camouflage of a persons uniform, type of cap and the type of badge/logo. The detailed analysis done include; camouflage cap and plain cap differentiation using gray level co-occurrence matrix (GLCM) texture feature; classification on Army, Air Force and Navy camouflaged uniforms using GLCM texture and colour histogram bin features; plain cap badge classification into Army, Air Force and Navy using Speed Up Robust Feature (SURF). The proposed method recognised camouflage personnel arm of service on sets of data retrieved from google images and selected military websites. Correlation-based Feature Selection (CFS) was used to improve recognition and reduce dimensionality, thereby speeding the classification process. With this method success rates recorded during the analysis include 93.8% for camouflage appearance category, 100%, 90% and 100% rates of plain cap and camouflage cap categories for Army, Air Force and Navy categories, respectively. Accurate recognition was recorded using SURF for the plain cap badge category. Substantial analysis has been carried out and results prove that the proposed method can correctly classify military personnel into various arms of service. We show that the proposed method can be integrated into a face recognition system, which will recognise personnel in addition to determining the arm of service which the personnel belong. Such a system can be used to enhance the security of a military base or facility.

The Rotated Speeded-Up Robust Features Algorithm (R-SURF)

DTIC Science & Technology

2014-06-01

blue color model YUV one luminance two chrominance color model xviii THIS PAGE INTENTIONALLY LEFT BLANK xix EXECUTIVE SUMMARY Automatic...256 256 3  color scheme with an uncompressed image is used, each visual pixel has a possibility of 3256 combinations 2 [5]. There are...Portugal, 2009. [41] J. Sivic and A. Zisserman, “Efficient visual search of videos cast as text retrieval,” IEEE Transactions on Pattern Analysis and

Face recognition from unconstrained three-dimensional face images using multitask sparse representation

NASA Astrophysics Data System (ADS)

Bentaieb, Samia; Ouamri, Abdelaziz; Nait-Ali, Amine; Keche, Mokhtar

2018-01-01

We propose and evaluate a three-dimensional (3D) face recognition approach that applies the speeded up robust feature (SURF) algorithm to the depth representation of shape index map, under real-world conditions, using only a single gallery sample for each subject. First, the 3D scans are preprocessed, then SURF is applied on the shape index map to find interest points and their descriptors. Each 3D face scan is represented by keypoints descriptors, and a large dictionary is built from all the gallery descriptors. At the recognition step, descriptors of a probe face scan are sparsely represented by the dictionary. A multitask sparse representation classification is used to determine the identity of each probe face. The feasibility of the approach that uses the SURF algorithm on the shape index map for face identification/authentication is checked through an experimental investigation conducted on Bosphorus, University of Milano Bicocca, and CASIA 3D datasets. It achieves an overall rank one recognition rate of 97.75%, 80.85%, and 95.12%, respectively, on these datasets.

An improved feature extraction algorithm based on KAZE for multi-spectral image

NASA Astrophysics Data System (ADS)

Yang, Jianping; Li, Jun

2018-02-01

Multi-spectral image contains abundant spectral information, which is widely used in all fields like resource exploration, meteorological observation and modern military. Image preprocessing, such as image feature extraction and matching, is indispensable while dealing with multi-spectral remote sensing image. Although the feature matching algorithm based on linear scale such as SIFT and SURF performs strong on robustness, the local accuracy cannot be guaranteed. Therefore, this paper proposes an improved KAZE algorithm, which is based on nonlinear scale, to raise the number of feature and to enhance the matching rate by using the adjusted-cosine vector. The experiment result shows that the number of feature and the matching rate of the improved KAZE are remarkably than the original KAZE algorithm.

High resolution satellite image indexing and retrieval using SURF features and bag of visual words

NASA Astrophysics Data System (ADS)

Bouteldja, Samia; Kourgli, Assia

2017-03-01

In this paper, we evaluate the performance of SURF descriptor for high resolution satellite imagery (HRSI) retrieval through a BoVW model on a land-use/land-cover (LULC) dataset. Local feature approaches such as SIFT and SURF descriptors can deal with a large variation of scale, rotation and illumination of the images, providing, therefore, a better discriminative power and retrieval efficiency than global features, especially for HRSI which contain a great range of objects and spatial patterns. Moreover, we combine SURF and color features to improve the retrieval accuracy, and we propose to learn a category-specific dictionary for each image category which results in a more discriminative image representation and boosts the image retrieval performance.

Uncalibrated stereo rectification and disparity range stabilization: a comparison of different feature detectors

NASA Astrophysics Data System (ADS)

Luo, Xiongbiao; Jayarathne, Uditha L.; McLeod, A. Jonathan; Pautler, Stephen E.; Schlacta, Christopher M.; Peters, Terry M.

2016-03-01

This paper studies uncalibrated stereo rectification and stable disparity range determination for surgical scene three-dimensional (3-D) reconstruction. Stereoscopic endoscope calibration sometimes is not available and also increases the complexity of the operating-room environment. Stereo from uncalibrated endoscopic cameras is an alternative to reconstruct the surgical field visualized by binocular endoscopes within the body. Uncalibrated rectification is usually performed on the basis of a number of matched feature points (semi-dense correspondence) between the left and the right images of stereo pairs. After uncalibrated rectification, the corresponding feature points can be used to determine the proper disparity range that helps to improve the reconstruction accuracy and reduce the computational time of disparity map estimation. Therefore, the corresponding or matching accuracy and robustness of feature point descriptors is important to surgical field 3-D reconstruction. This work compares four feature detectors: (1) scale invariant feature transform (SIFT), (2) speeded up robust features (SURF), (3) affine scale invariant feature transform (ASIFT), and (4) gauge speeded up robust features (GSURF) with applications to uncalibrated rectification and stable disparity range determination. We performed our experiments on surgical endoscopic video images that were collected during robotic prostatectomy. The experimental results demonstrate that ASIFT outperforms other feature detectors in the uncalibrated stereo rectification and also provides a stable stable disparity range for surgical scene reconstruction.

SKL algorithm based fabric image matching and retrieval

NASA Astrophysics Data System (ADS)

Cao, Yichen; Zhang, Xueqin; Ma, Guojian; Sun, Rongqing; Dong, Deping

2017-07-01

Intelligent computer image processing technology provides convenience and possibility for designers to carry out designs. Shape analysis can be achieved by extracting SURF feature. However, high dimension of SURF feature causes to lower matching speed. To solve this problem, this paper proposed a fast fabric image matching algorithm based on SURF K-means and LSH algorithm. By constructing the bag of visual words on K-Means algorithm, and forming feature histogram of each image, the dimension of SURF feature is reduced at the first step. Then with the help of LSH algorithm, the features are encoded and the dimension is further reduced. In addition, the indexes of each image and each class of image are created, and the number of matching images is decreased by LSH hash bucket. Experiments on fabric image database show that this algorithm can speed up the matching and retrieval process, the result can satisfy the requirement of dress designers with accuracy and speed.

A robust method for estimating motorbike count based on visual information learning

NASA Astrophysics Data System (ADS)

Huynh, Kien C.; Thai, Dung N.; Le, Sach T.; Thoai, Nam; Hamamoto, Kazuhiko

2015-03-01

Estimating the number of vehicles in traffic videos is an important and challenging task in traffic surveillance, especially with a high level of occlusions between vehicles, e.g.,in crowded urban area with people and/or motorbikes. In such the condition, the problem of separating individual vehicles from foreground silhouettes often requires complicated computation [1][2][3]. Thus, the counting problem is gradually shifted into drawing statistical inferences of target objects density from their shape [4], local features [5], etc. Those researches indicate a correlation between local features and the number of target objects. However, they are inadequate to construct an accurate model for vehicles density estimation. In this paper, we present a reliable method that is robust to illumination changes and partial affine transformations. It can achieve high accuracy in case of occlusions. Firstly, local features are extracted from images of the scene using Speed-Up Robust Features (SURF) method. For each image, a global feature vector is computed using a Bag-of-Words model which is constructed from the local features above. Finally, a mapping between the extracted global feature vectors and their labels (the number of motorbikes) is learned. That mapping provides us a strong prediction model for estimating the number of motorbikes in new images. The experimental results show that our proposed method can achieve a better accuracy in comparison to others.

Fuzzy based finger vein recognition with rotation invariant feature matching

NASA Astrophysics Data System (ADS)

Ezhilmaran, D.; Joseph, Rose Bindu

2017-11-01

Finger vein recognition is a promising biometric with commercial applications which is explored widely in the recent years. In this paper, a finger vein recognition system is proposed using rotation invariant feature descriptors for matching after enhancing the finger vein images with an interval type-2 fuzzy method. SIFT features are extracted and matched using a matching score based on Euclidian distance. Rotation invariance of the proposed method is verified in the experiment and the results are compared with SURF matching and minutiae matching. It is seen that rotation invariance is verified and the poor quality issues are solved efficiently with the designed system of finger vein recognition during the analysis. The experiments underlines the robustness and reliability of the interval type-2 fuzzy enhancement and SIFT feature matching.

Gender Recognition from Human-Body Images Using Visible-Light and Thermal Camera Videos Based on a Convolutional Neural Network for Image Feature Extraction

PubMed Central

Nguyen, Dat Tien; Kim, Ki Wan; Hong, Hyung Gil; Koo, Ja Hyung; Kim, Min Cheol; Park, Kang Ryoung

2017-01-01

Extracting powerful image features plays an important role in computer vision systems. Many methods have previously been proposed to extract image features for various computer vision applications, such as the scale-invariant feature transform (SIFT), speed-up robust feature (SURF), local binary patterns (LBP), histogram of oriented gradients (HOG), and weighted HOG. Recently, the convolutional neural network (CNN) method for image feature extraction and classification in computer vision has been used in various applications. In this research, we propose a new gender recognition method for recognizing males and females in observation scenes of surveillance systems based on feature extraction from visible-light and thermal camera videos through CNN. Experimental results confirm the superiority of our proposed method over state-of-the-art recognition methods for the gender recognition problem using human body images. PMID:28335510

Gender Recognition from Human-Body Images Using Visible-Light and Thermal Camera Videos Based on a Convolutional Neural Network for Image Feature Extraction.

PubMed

Nguyen, Dat Tien; Kim, Ki Wan; Hong, Hyung Gil; Koo, Ja Hyung; Kim, Min Cheol; Park, Kang Ryoung

2017-03-20

Extracting powerful image features plays an important role in computer vision systems. Many methods have previously been proposed to extract image features for various computer vision applications, such as the scale-invariant feature transform (SIFT), speed-up robust feature (SURF), local binary patterns (LBP), histogram of oriented gradients (HOG), and weighted HOG. Recently, the convolutional neural network (CNN) method for image feature extraction and classification in computer vision has been used in various applications. In this research, we propose a new gender recognition method for recognizing males and females in observation scenes of surveillance systems based on feature extraction from visible-light and thermal camera videos through CNN. Experimental results confirm the superiority of our proposed method over state-of-the-art recognition methods for the gender recognition problem using human body images.

Uniform competency-based local feature extraction for remote sensing images

NASA Astrophysics Data System (ADS)

Sedaghat, Amin; Mohammadi, Nazila

2018-01-01

Local feature detectors are widely used in many photogrammetry and remote sensing applications. The quantity and distribution of the local features play a critical role in the quality of the image matching process, particularly for multi-sensor high resolution remote sensing image registration. However, conventional local feature detectors cannot extract desirable matched features either in terms of the number of correct matches or the spatial and scale distribution in multi-sensor remote sensing images. To address this problem, this paper proposes a novel method for uniform and robust local feature extraction for remote sensing images, which is based on a novel competency criterion and scale and location distribution constraints. The proposed method, called uniform competency (UC) local feature extraction, can be easily applied to any local feature detector for various kinds of applications. The proposed competency criterion is based on a weighted ranking process using three quality measures, including robustness, spatial saliency and scale parameters, which is performed in a multi-layer gridding schema. For evaluation, five state-of-the-art local feature detector approaches, namely, scale-invariant feature transform (SIFT), speeded up robust features (SURF), scale-invariant feature operator (SFOP), maximally stable extremal region (MSER) and hessian-affine, are used. The proposed UC-based feature extraction algorithms were successfully applied to match various synthetic and real satellite image pairs, and the results demonstrate its capability to increase matching performance and to improve the spatial distribution. The code to carry out the UC feature extraction is available from href="https://www.researchgate.net/publication/317956777_UC-Feature_Extraction.

Detection of Perlger-Huet anomaly based on augmented fast marching method and speeded up robust features.

PubMed

Sun, Minglei; Yang, Shaobao; Jiang, Jinling; Wang, Qiwei

2015-01-01

Pelger-Huet anomaly (PHA) and Pseudo Pelger-Huet anomaly (PPHA) are neutrophil with abnormal morphology. They have the bilobed or unilobed nucleus and excessive clumping chromatin. Currently, detection of this kind of cell mainly depends on the manual microscopic examination by a clinician, thus, the quality of detection is limited by the efficiency and a certain subjective consciousness of the clinician. In this paper, a detection method for PHA and PPHA is proposed based on karyomorphism and chromatin distribution features. Firstly, the skeleton of the nucleus is extracted using an augmented Fast Marching Method (AFMM) and width distribution is obtained through distance transform. Then, caryoplastin in the nucleus is extracted based on Speeded Up Robust Features (SURF) and a K-nearest-neighbor (KNN) classifier is constructed to analyze the features. Experiment shows that the sensitivity and specificity of this method achieved 87.5% and 83.33%, which means that the detection accuracy of PHA is acceptable. Meanwhile, the detection method should be helpful to the automatic morphological classification of blood cells.

Spatio-temporal features for tracking and quadruped/biped discrimination

NASA Astrophysics Data System (ADS)

Rickman, Rick; Copsey, Keith; Bamber, David C.; Page, Scott F.

2012-05-01

Techniques such as SIFT and SURF facilitate efficient and robust image processing operations through the use of sparse and compact spatial feature descriptors and show much potential for defence and security applications. This paper considers the extension of such techniques to include information from the temporal domain, to improve utility in applications involving moving imagery within video data. In particular, the paper demonstrates how spatio-temporal descriptors can be used very effectively as the basis of a target tracking system and as target discriminators which can distinguish between bipeds and quadrupeds. Results using sequences of video imagery of walking humans and dogs are presented, and the relative merits of the approach are discussed.

A scale-invariant keypoint detector in log-polar space

NASA Astrophysics Data System (ADS)

Tao, Tao; Zhang, Yun

2017-02-01

The scale-invariant feature transform (SIFT) algorithm is devised to detect keypoints via the difference of Gaussian (DoG) images. However, the DoG data lacks the high-frequency information, which can lead to a performance drop of the algorithm. To address this issue, this paper proposes a novel log-polar feature detector (LPFD) to detect scale-invariant blubs (keypoints) in log-polar space, which, in contrast, can retain all the image information. The algorithm consists of three components, viz. keypoint detection, descriptor extraction and descriptor matching. Besides, the algorithm is evaluated in detecting keypoints from the INRIA dataset by comparing with the SIFT algorithm and one of its fast versions, the speed up robust features (SURF) algorithm in terms of three performance measures, viz. correspondences, repeatability, correct matches and matching score.

Long-term scale adaptive tracking with kernel correlation filters

NASA Astrophysics Data System (ADS)

Wang, Yueren; Zhang, Hong; Zhang, Lei; Yang, Yifan; Sun, Mingui

2018-04-01

Object tracking in video sequences has broad applications in both military and civilian domains. However, as the length of input video sequence increases, a number of problems arise, such as severe object occlusion, object appearance variation, and object out-of-view (some portion or the entire object leaves the image space). To deal with these problems and identify the object being tracked from cluttered background, we present a robust appearance model using Speeded Up Robust Features (SURF) and advanced integrated features consisting of the Felzenszwalb's Histogram of Oriented Gradients (FHOG) and color attributes. Since re-detection is essential in long-term tracking, we develop an effective object re-detection strategy based on moving area detection. We employ the popular kernel correlation filters in our algorithm design, which facilitates high-speed object tracking. Our evaluation using the CVPR2013 Object Tracking Benchmark (OTB2013) dataset illustrates that the proposed algorithm outperforms reference state-of-the-art trackers in various challenging scenarios.

Low-power coprocessor for Haar-like feature extraction with pixel-based pipelined architecture

NASA Astrophysics Data System (ADS)

Luo, Aiwen; An, Fengwei; Fujita, Yuki; Zhang, Xiangyu; Chen, Lei; Jürgen Mattausch, Hans

2017-04-01

Intelligent analysis of image and video data requires image-feature extraction as an important processing capability for machine-vision realization. A coprocessor with pixel-based pipeline (CFEPP) architecture is developed for real-time Haar-like cell-based feature extraction. Synchronization with the image sensor’s pixel frequency and immediate usage of each input pixel for the feature-construction process avoids the dependence on memory-intensive conventional strategies like integral-image construction or frame buffers. One 180 nm CMOS prototype can extract the 1680-dimensional Haar-like feature vectors, applied in the speeded up robust features (SURF) scheme, using an on-chip memory of only 96 kb (kilobit). Additionally, a low power dissipation of only 43.45 mW at 1.8 V supply voltage is achieved during VGA video procession at 120 MHz frequency with more than 325 fps. The Haar-like feature-extraction coprocessor is further evaluated by the practical application of vehicle recognition, achieving the expected high accuracy which is comparable to previous work.

Comparison of k-means related clustering methods for nuclear medicine images segmentation

NASA Astrophysics Data System (ADS)

Borys, Damian; Bzowski, Pawel; Danch-Wierzchowska, Marta; Psiuk-Maksymowicz, Krzysztof

2017-03-01

In this paper, we evaluate the performance of SURF descriptor for high resolution satellite imagery (HRSI) retrieval through a BoVW model on a land-use/land-cover (LULC) dataset. Local feature approaches such as SIFT and SURF descriptors can deal with a large variation of scale, rotation and illumination of the images, providing, therefore, a better discriminative power and retrieval efficiency than global features, especially for HRSI which contain a great range of objects and spatial patterns. Moreover, we combine SURF and color features to improve the retrieval accuracy, and we propose to learn a category-specific dictionary for each image category which results in a more discriminative image representation and boosts the image retrieval performance.

Pose Estimation of a Mobile Robot Based on Fusion of IMU Data and Vision Data Using an Extended Kalman Filter.

PubMed

Alatise, Mary B; Hancke, Gerhard P

2017-09-21

Using a single sensor to determine the pose estimation of a device cannot give accurate results. This paper presents a fusion of an inertial sensor of six degrees of freedom (6-DoF) which comprises the 3-axis of an accelerometer and the 3-axis of a gyroscope, and a vision to determine a low-cost and accurate position for an autonomous mobile robot. For vision, a monocular vision-based object detection algorithm speeded-up robust feature (SURF) and random sample consensus (RANSAC) algorithms were integrated and used to recognize a sample object in several images taken. As against the conventional method that depend on point-tracking, RANSAC uses an iterative method to estimate the parameters of a mathematical model from a set of captured data which contains outliers. With SURF and RANSAC, improved accuracy is certain; this is because of their ability to find interest points (features) under different viewing conditions using a Hessain matrix. This approach is proposed because of its simple implementation, low cost, and improved accuracy. With an extended Kalman filter (EKF), data from inertial sensors and a camera were fused to estimate the position and orientation of the mobile robot. All these sensors were mounted on the mobile robot to obtain an accurate localization. An indoor experiment was carried out to validate and evaluate the performance. Experimental results show that the proposed method is fast in computation, reliable and robust, and can be considered for practical applications. The performance of the experiments was verified by the ground truth data and root mean square errors (RMSEs).

Pose Estimation of a Mobile Robot Based on Fusion of IMU Data and Vision Data Using an Extended Kalman Filter

PubMed Central

Hancke, Gerhard P.

2017-01-01

Using a single sensor to determine the pose estimation of a device cannot give accurate results. This paper presents a fusion of an inertial sensor of six degrees of freedom (6-DoF) which comprises the 3-axis of an accelerometer and the 3-axis of a gyroscope, and a vision to determine a low-cost and accurate position for an autonomous mobile robot. For vision, a monocular vision-based object detection algorithm speeded-up robust feature (SURF) and random sample consensus (RANSAC) algorithms were integrated and used to recognize a sample object in several images taken. As against the conventional method that depend on point-tracking, RANSAC uses an iterative method to estimate the parameters of a mathematical model from a set of captured data which contains outliers. With SURF and RANSAC, improved accuracy is certain; this is because of their ability to find interest points (features) under different viewing conditions using a Hessain matrix. This approach is proposed because of its simple implementation, low cost, and improved accuracy. With an extended Kalman filter (EKF), data from inertial sensors and a camera were fused to estimate the position and orientation of the mobile robot. All these sensors were mounted on the mobile robot to obtain an accurate localization. An indoor experiment was carried out to validate and evaluate the performance. Experimental results show that the proposed method is fast in computation, reliable and robust, and can be considered for practical applications. The performance of the experiments was verified by the ground truth data and root mean square errors (RMSEs). PMID:28934102

Design and implementation of a vision-based hovering and feature tracking algorithm for a quadrotor

NASA Astrophysics Data System (ADS)

Lee, Y. H.; Chahl, J. S.

2016-10-01

This paper demonstrates an approach to the vision-based control of the unmanned quadrotors for hover and object tracking. The algorithms used the Speed Up Robust Features (SURF) algorithm to detect objects. The pose of the object in the image was then calculated in order to pass the pose information to the flight controller. Finally, the flight controller steered the quadrotor to approach the object based on the calculated pose data. The above processes was run using standard onboard resources found in the 3DR Solo quadrotor in an embedded computing environment. The obtained results showed that the algorithm behaved well during its missions, tracking and hovering, although there were significant latencies due to low CPU performance of the onboard image processing system.

Compact and Hybrid Feature Description for Building Extraction

NASA Astrophysics Data System (ADS)

Li, Z.; Liu, Y.; Hu, Y.; Li, P.; Ding, Y.

2017-05-01

Building extraction in aerial orthophotos is crucial for various applications. Currently, deep learning has been shown to be successful in addressing building extraction with high accuracy and high robustness. However, quite a large number of samples is required in training a classifier when using deep learning model. In order to realize accurate and semi-interactive labelling, the performance of feature description is crucial, as it has significant effect on the accuracy of classification. In this paper, we bring forward a compact and hybrid feature description method, in order to guarantees desirable classification accuracy of the corners on the building roof contours. The proposed descriptor is a hybrid description of an image patch constructed from 4 sets of binary intensity tests. Experiments show that benefiting from binary description and making full use of color channels, this descriptor is not only computationally frugal, but also accurate than SURF for building extraction.

Clinical and magnetic resonance imaging findings in patients with Leigh syndrome and SURF1 mutations.

PubMed

Sonam, Kothari; Khan, Nahid Akthar; Bindu, Parayil Sankaran; Taly, Arun B; Gayathri, N; Bharath, M M Srinivas; Govindaraju, C; Arvinda, H R; Nagappa, Madhu; Sinha, Sanjib; Thangaraj, K

2014-10-01

Mutation in the SURF1 is one of the most common nuclear mutations associated with Leigh syndrome and cytochrome c oxidase deficiency. This study aims to describe the phenotypic and imaging features in four patients with Leigh syndrome and novel SURF1 mutation. The study included four patients with Leigh syndrome and SURF1 mutations identified from a cohort of 25 children with Leigh syndrome seen over a period of six years (2006-2012). All the patients underwent a detailed neurological assessment, muscle biopsy, and sequencing of the complete mitochondrial genome and SURF1. Three patients had classical presentation of Leigh syndrome. The fourth patient had a later age of onset with ataxia as the presenting manifestation and a stable course. Hypertrichosis, facial dysmorphism and hypopigmentation were the additional phenotypic features noted. On magnetic resonance imaging all patients had brainstem and cerebellar involvement and two had basal ganglia involvement in addition. The bilateral symmetrical hypertrophic olivary degeneration in these patients was striking. The SURF1 analysis identified previously unreported mutations in all the patients. On follow-up three patients expired and one had a stable course. Patients with Leigh syndrome and SURF1 mutation often have skin and hair abnormalities. Bilateral symmetrical hypertrophic olivary degeneration was a consistent finding on magnetic resonance imaging in these patients. Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Infrared and visible images registration with adaptable local-global feature integration for rail inspection

NASA Astrophysics Data System (ADS)

Tang, Chaoqing; Tian, Gui Yun; Chen, Xiaotian; Wu, Jianbo; Li, Kongjing; Meng, Hongying

2017-12-01

Active thermography provides infrared images that contain sub-surface defect information, while visible images only reveal surface information. Mapping infrared information to visible images offers more comprehensive visualization for decision-making in rail inspection. However, the common information for registration is limited due to different modalities in both local and global level. For example, rail track which has low temperature contrast reveals rich details in visible images, but turns blurry in the infrared counterparts. This paper proposes a registration algorithm called Edge-Guided Speeded-Up-Robust-Features (EG-SURF) to address this issue. Rather than sequentially integrating local and global information in matching stage which suffered from buckets effect, this algorithm adaptively integrates local and global information into a descriptor to gather more common information before matching. This adaptability consists of two facets, an adaptable weighting factor between local and global information, and an adaptable main direction accuracy. The local information is extracted using SURF while the global information is represented by shape context from edges. Meanwhile, in shape context generation process, edges are weighted according to local scale and decomposed into bins using a vector decomposition manner to provide more accurate descriptor. The proposed algorithm is qualitatively and quantitatively validated using eddy current pulsed thermography scene in the experiments. In comparison with other algorithms, better performance has been achieved.

Automated detection of microaneurysms using robust blob descriptors

NASA Astrophysics Data System (ADS)

Adal, K.; Ali, S.; Sidibé, D.; Karnowski, T.; Chaum, E.; Mériaudeau, F.

2013-03-01

Microaneurysms (MAs) are among the first signs of diabetic retinopathy (DR) that can be seen as round dark-red structures in digital color fundus photographs of retina. In recent years, automated computer-aided detection and diagnosis (CAD) of MAs has attracted many researchers due to its low-cost and versatile nature. In this paper, the MA detection problem is modeled as finding interest points from a given image and several interest point descriptors are introduced and integrated with machine learning techniques to detect MAs. The proposed approach starts by applying a novel fundus image contrast enhancement technique using Singular Value Decomposition (SVD) of fundus images. Then, Hessian-based candidate selection algorithm is applied to extract image regions which are more likely to be MAs. For each candidate region, robust low-level blob descriptors such as Speeded Up Robust Features (SURF) and Intensity Normalized Radon Transform are extracted to characterize candidate MA regions. The combined features are then classified using SVM which has been trained using ten manually annotated training images. The performance of the overall system is evaluated on Retinopathy Online Challenge (ROC) competition database. Preliminary results show the competitiveness of the proposed candidate selection techniques against state-of-the art methods as well as the promising future for the proposed descriptors to be used in the localization of MAs from fundus images.

Stopover habitats of spring migrating surf scoters in southeast Alaska

USGS Publications Warehouse

Lok, E.K.; Esler, Daniel N.; Takekawa, John Y.; De La Cruz, S.W.; Sean, Boyd W.; Nysewander, D.R.; Evenson, J.R.; Ward, D.H.

2011-01-01

Habitat conditions and nutrient reserve levels during spring migration have been suggested as important factors affecting population declines in waterfowl, emphasizing the need to identify key sites used during spring and understand habitat features and resource availability at stopover sites. We used satellite telemetry to identify stopover sites used by surf scoters migrating through southeast Alaska during spring. We then contrasted habitat features of these sites to those of random sites to determine habitat attributes corresponding to use by migrating scoters. We identified 14 stopover sites based on use by satellite tagged surf scoters from several wintering sites. We identified Lynn Canal as a particularly important stopover site for surf scoters originating throughout the Pacific winter range; approximately half of tagged coastally migrating surf scoters used this site, many for extended periods. Stopover sites were farther from the mainland coast and closer to herring spawn sites than random sites, whereas physical shoreline habitat attributes were generally poor predictors of site use. The geography and resource availability within southeast Alaska provides unique and potentially critical stopover habitat for spring migrating surf scoters. Our work identifies specific sites and habitat resources that deserve conservation and management consideration. Aggregations of birds are vulnerable to human activity impacts such as contaminant spills and resource management decisions. This information is of value to agencies and organizations responsible for emergency response planning, herring fisheries management, and bird and ecosystem conservation.

Euro Banknote Recognition System for Blind People.

PubMed

Dunai Dunai, Larisa; Chillarón Pérez, Mónica; Peris-Fajarnés, Guillermo; Lengua Lengua, Ismael

2017-01-20

This paper presents the development of a portable system with the aim of allowing blind people to detect and recognize Euro banknotes. The developed device is based on a Raspberry Pi electronic instrument and a Raspberry Pi camera, Pi NoIR (No Infrared filter) dotted with additional infrared light, which is embedded into a pair of sunglasses that permit blind and visually impaired people to independently handle Euro banknotes, especially when receiving their cash back when shopping. The banknote detection is based on the modified Viola and Jones algorithms, while the banknote value recognition relies on the Speed Up Robust Features (SURF) technique. The accuracies of banknote detection and banknote value recognition are 84% and 97.5%, respectively.

Euro Banknote Recognition System for Blind People

PubMed Central

Dunai Dunai, Larisa; Chillarón Pérez, Mónica; Peris-Fajarnés, Guillermo; Lengua Lengua, Ismael

2017-01-01

This paper presents the development of a portable system with the aim of allowing blind people to detect and recognize Euro banknotes. The developed device is based on a Raspberry Pi electronic instrument and a Raspberry Pi camera, Pi NoIR (No Infrared filter) dotted with additional infrared light, which is embedded into a pair of sunglasses that permit blind and visually impaired people to independently handle Euro banknotes, especially when receiving their cash back when shopping. The banknote detection is based on the modified Viola and Jones algorithms, while the banknote value recognition relies on the Speed Up Robust Features (SURF) technique. The accuracies of banknote detection and banknote value recognition are 84% and 97.5%, respectively. PMID:28117703

A Method for Counting Moving People in Video Surveillance Videos

NASA Astrophysics Data System (ADS)

Conte, Donatello; Foggia, Pasquale; Percannella, Gennaro; Tufano, Francesco; Vento, Mario

2010-12-01

People counting is an important problem in video surveillance applications. This problem has been faced either by trying to detect people in the scene and then counting them or by establishing a mapping between some scene feature and the number of people (avoiding the complex detection problem). This paper presents a novel method, following this second approach, that is based on the use of SURF features and of an [InlineEquation not available: see fulltext.]-SVR regressor provide an estimate of this count. The algorithm takes specifically into account problems due to partial occlusions and to perspective. In the experimental evaluation, the proposed method has been compared with the algorithm by Albiol et al., winner of the PETS 2009 contest on people counting, using the same PETS 2009 database. The provided results confirm that the proposed method yields an improved accuracy, while retaining the robustness of Albiol's algorithm.

Robust feature estimation by non-rigid hierarchical image registration and its application in disparity measurement

NASA Astrophysics Data System (ADS)

Badshah, Amir; Choudhry, Aadil Jaleel; Ullah, Shan

2017-03-01

Industries are moving towards automation in order to increase productivity and ensure quality. Variety of electronic and electromagnetic systems are being employed to assist human operator in fast and accurate quality inspection of products. Majority of these systems are equipped with cameras and rely on diverse image processing algorithms. Information is lost in 2D image, therefore acquiring accurate 3D data from 2D images is an open issue. FAST, SURF and SIFT are well-known spatial domain techniques for features extraction and henceforth image registration to find correspondence between images. The efficiency of these methods is measured in terms of the number of perfect matches found. A novel fast and robust technique for stereo-image processing is proposed. It is based on non-rigid registration using modified normalized phase correlation. The proposed method registers two images in hierarchical fashion using quad-tree structure. The registration process works through global to local level resulting in robust matches even in presence of blur and noise. The computed matches can further be utilized to determine disparity and depth for industrial product inspection. The same can be used in driver assistance systems. The preliminary tests on Middlebury dataset produced satisfactory results. The execution time for a 413 x 370 stereo-pair is 500ms approximately on a low cost DSP.

The Evolution of Technology: A Decade of Surfing the Net

ERIC Educational Resources Information Center

Berger, Sandra

2005-01-01

The world was a different place when "Understanding Our Gifted" introduced "Surfing the Net" in 1994 as a regular feature. Since then, technology and the Internet have become part of people's culture, permeating almost every aspect of their lives. The Internet has greatly changed the way they conduct business and communicate with friends, it helps…

Medical surfing.

PubMed

Khan, L A; Khan, S A

2001-11-01

The Internet has revolutionized information technology. Vast amounts of latest information are available on the Internet to medical professionals. Medical surfing is fast becoming part of a doctor's profession. But the way to approach the Internet and retrieve useful information from myriads of medical websites seems a daunting task to many. This review aims to help the newcomer, the medical students and doctors in obtaining fruitful medical information while surfing. It will prevent them from the feeling of getting drowned in the ocean of medical information. As medical information is not restricted to books and journals, providing Internet addresses of different medical bodies with few salient features, will go a long way in helping attain the required information without wasting time. The Internet will soon become a universal library. Medical surfing should be included in the curriculum of all medical schools and universities.

Iris features-based heart disease diagnosis by computer vision

NASA Astrophysics Data System (ADS)

Nguchu, Benedictor A.; Li, Li

2017-07-01

The study takes advantage of several new breakthroughs in computer vision technology to develop a new mid-irisbiomedical platform that processes iris image for early detection of heart-disease. Guaranteeing early detection of heart disease provides a possibility of having non-surgical treatment as suggested by biomedical researchers and associated institutions. However, our observation discovered that, a clinical practicable solution which could be both sensible and specific for early detection is still lacking. Due to this, the rate of majority vulnerable to death is highly increasing. The delayed diagnostic procedures, inefficiency, and complications of available methods are the other reasons for this catastrophe. Therefore, this research proposes the novel IFB (Iris Features Based) method for diagnosis of premature, and early stage heart disease. The method incorporates computer vision and iridology to obtain a robust, non-contact, nonradioactive, and cost-effective diagnostic tool. The method analyzes abnormal inherent weakness in tissues, change in color and patterns, of a specific region of iris that responds to impulses of heart organ as per Bernard Jensen-iris Chart. The changes in iris infer the presence of degenerative abnormalities in heart organ. These changes are precisely detected and analyzed by IFB method that includes, tensor-based-gradient(TBG), multi orientations gabor filters(GF), textural oriented features(TOF), and speed-up robust features(SURF). Kernel and Multi class oriented support vector machines classifiers are used for classifying normal and pathological iris features. Experimental results demonstrated that the proposed method, not only has better diagnostic performance, but also provides an insight for early detection of other diseases.

Investigation of kinematic features for dismount detection and tracking

NASA Astrophysics Data System (ADS)

Narayanaswami, Ranga; Tyurina, Anastasia; Diel, David; Mehra, Raman K.; Chinn, Janice M.

2012-05-01

With recent changes in threats and methods of warfighting and the use of unmanned aircrafts, ISR (Intelligence, Surveillance and Reconnaissance) activities have become critical to the military's efforts to maintain situational awareness and neutralize the enemy's activities. The identification and tracking of dismounts from surveillance video is an important step in this direction. Our approach combines advanced ultra fast registration techniques to identify moving objects with a classification algorithm based on both static and kinematic features of the objects. Our objective was to push the acceptable resolution beyond the capability of industry standard feature extraction methods such as SIFT (Scale Invariant Feature Transform) based features and inspired by it, SURF (Speeded-Up Robust Feature). Both of these methods utilize single frame images. We exploited the temporal component of the video signal to develop kinematic features. Of particular interest were the easily distinguishable frequencies characteristic of bipedal human versus quadrupedal animal motion. We examine limits of performance, frame rates and resolution required for human, animal and vehicles discrimination. A few seconds of video signal with the acceptable frame rate allow us to lower resolution requirements for individual frames as much as by a factor of five, which translates into the corresponding increase of the acceptable standoff distance between the sensor and the object of interest.

Study on Low Illumination Simultaneous Polarization Image Registration Based on Improved SURF Algorithm

NASA Astrophysics Data System (ADS)

Zhang, Wanjun; Yang, Xu

2017-12-01

Registration of simultaneous polarization images is the premise of subsequent image fusion operations. However, in the process of shooting all-weather, the polarized camera exposure time need to be kept unchanged, sometimes polarization images under low illumination conditions due to too dark result in SURF algorithm can not extract feature points, thus unable to complete the registration, therefore this paper proposes an improved SURF algorithm. Firstly, the luminance operator is used to improve overall brightness of low illumination image, and then create integral image, using Hession matrix to extract the points of interest to get the main direction of characteristic points, calculate Haar wavelet response in X and Y directions to get the SURF descriptor information, then use the RANSAC function to make precise matching, the function can eliminate wrong matching points and improve accuracy rate. And finally resume the brightness of the polarized image after registration, the effect of the polarized image is not affected. Results show that the improved SURF algorithm can be applied well under low illumination conditions.

Surf zone entrainment, along-shore transport, and human health implications of pollution from tidal outlets

NASA Astrophysics Data System (ADS)

Grant, S. B.; Kim, J. H.; Jones, B. H.; Jenkins, S. A.; Wasyl, J.; Cudaback, C.

2005-10-01

Field experiments and modeling studies were carried out to characterize the surf zone entrainment and along-shore transport of pollution from two tidal outlets that drain into Huntington Beach and Newport Beach, popular public beaches in southern California. The surf zone entrainment and near-shore transport of pollutants from these tidal outlets appears to be controlled by prevailing wave conditions and coastal currents, and fine-scale features of the flow field around the outlets. An analysis of data from dye experiments and fecal indicator bacteria monitoring studies reveals that the along-shore flux of surf zone water is at least 50 to 300 times larger than the cross-shore flux of surf zone water. As a result, pollutants entrained in the surf zone hug the shore, where they travel significant distances parallel to the beach before diluting to extinction. Under the assumption that all surf zone pollution at Huntington Beach originates from two tidal outlets, the Santa Ana River and Talbert Marsh outlets, models of mass and momentum transport in the surf zone approximately capture the observed tidal phasing and magnitude of certain fecal indicator bacteria groups (total coliform) but not others (Escherichia coli and enterococci), implying the existence of multiple sources of, and/or multiple transport pathways for, fecal pollution at this site. The intersection of human recreation and near-shore pollution pathways implies that, from a human health perspective, special care should be taken to reduce the discharge of harmful pollutants from land-side sources of surface water runoff, such as tidal outlets and storm drains.

New Analysis Method Application in Metallographic Images through the Construction of Mosaics Via Speeded Up Robust Features and Scale Invariant Feature Transform

PubMed Central

Rebouças Filho, Pedro Pedrosa; Moreira, Francisco Diego Lima; Xavier, Francisco Geilson de Lima; Gomes, Samuel Luz; dos Santos, José Ciro; Freitas, Francisco Nélio Costa; Freitas, Rodrigo Guimarães

2015-01-01

In many applications in metallography and analysis, many regions need to be considered and not only the current region. In cases where there are analyses with multiple images, the specialist should also evaluate neighboring areas. For example, in metallurgy, welding technology is derived from conventional testing and metallographic analysis. In welding, these tests allow us to know the features of the metal, especially in the Heat-Affected Zone (HAZ); the region most likely for natural metallurgical problems to occur in welding. The expanse of the Heat-Affected Zone exceeds the size of the area observed through a microscope and typically requires multiple images to be mounted on a larger picture surface to allow for the study of the entire heat affected zone. This image stitching process is performed manually and is subject to all the inherent flaws of the human being due to results of fatigue and distraction. The analyzing of grain growth is also necessary in the examination of multiple regions, although not necessarily neighboring regions, but this analysis would be a useful tool to aid a specialist. In areas such as microscopic metallography, which study metallurgical products with the aid of a microscope, the assembly of mosaics is done manually, which consumes a lot of time and is also subject to failures due to human limitations. The mosaic technique is used in the construct of environment or scenes with corresponding characteristics between themselves. Through several small images, and with corresponding characteristics between themselves, a new model is generated in a larger size. This article proposes the use of Digital Image Processing for the automatization of the construction of these mosaics in metallographic images. The use of this proposed method is meant to significantly reduce the time required to build the mosaic and reduce the possibility of failures in assembling the final image; therefore increasing efficiency in obtaining results and expediting the decision making process. Two different methods are proposed: One using the transformed Scale Invariant Feature Transform (SIFT), and the second using features extractor Speeded Up Robust Features (SURF). Although slower, the SIFT method is more stable and has a better performance than the SURF method and can be applied to real applications. The best results were obtained using SIFT with Peak Signal-to-Noise Ratio = 61.38, Mean squared error = 0.048 and mean-structural-similarity = 0.999, and processing time of 4.91 seconds for mosaic building. The methodology proposed shows be more promissory in aiding specialists during analysis of metallographic images. PMID:28793412

Automatic orientation and 3D modelling from markerless rock art imagery

NASA Astrophysics Data System (ADS)

Lerma, J. L.; Navarro, S.; Cabrelles, M.; Seguí, A. E.; Hernández, D.

2013-02-01

This paper investigates the use of two detectors and descriptors on image pyramids for automatic image orientation and generation of 3D models. The detectors and descriptors replace manual measurements and are used to detect, extract and match features across multiple imagery. The Scale-Invariant Feature Transform (SIFT) and the Speeded Up Robust Features (SURF) will be assessed based on speed, number of features, matched features, and precision in image and object space depending on the adopted hierarchical matching scheme. The influence of applying in addition Area Based Matching (ABM) with normalised cross-correlation (NCC) and least squares matching (LSM) is also investigated. The pipeline makes use of photogrammetric and computer vision algorithms aiming minimum interaction and maximum accuracy from a calibrated camera. Both the exterior orientation parameters and the 3D coordinates in object space are sequentially estimated combining relative orientation, single space resection and bundle adjustment. The fully automatic image-based pipeline presented herein to automate the image orientation step of a sequence of terrestrial markerless imagery is compared with manual bundle block adjustment and terrestrial laser scanning (TLS) which serves as ground truth. The benefits of applying ABM after FBM will be assessed both in image and object space for the 3D modelling of a complex rock art shelter.

Feature Detection of Curve Traffic Sign Image on The Bandung - Jakarta Highway

NASA Astrophysics Data System (ADS)

Naseer, M.; Supriadi, I.; Supangkat, S. H.

2018-03-01

Unsealed roadside and problems with the road surface are common causes of road crashes, particularly when those are combined with curves. Curve traffic sign is an important component for giving early warning to driver on traffic, especially on high-speed traffic like on the highway. Traffic sign detection has became a very interesting research now, and in this paper will be discussed about the detection of curve traffic sign. There are two types of curve signs are discussed, namely the curve turn to the left and the curve turn to the right and the all data sample used are the curves taken / recorded from some signs on the Bandung - Jakarta Highway. Feature detection of the curve signs use Speed Up Robust Feature (SURF) method, where the detected scene image is 800x450. From 45 curve turn to the right images, the system can detect the feature well to 35 images, where the success rate is 77,78%, while from the 45 curve turn to the left images, the system can detect the feature well to 34 images and the success rate is 75,56%, so the average accuracy in the detection process is 76,67%. While the average time for the detection process is 0.411 seconds.

Understanding successful and unsuccessful landings of aerial maneuver variations in professional surfing.

PubMed

Forsyth, J R; Riddiford-Harland, D L; Whitting, J W; Sheppard, J M; Steele, J R

2018-05-01

Although performing aerial maneuvers can increase wave score and winning potential in competitive surfing, the critical features underlying successful aerial performance have not been systematically investigated. This study aimed to analyze highly skilled aerial maneuver performance and to identify the critical features associated with successful or unsuccessful landing. Using video recordings of the World Surf League's Championship Tour, every aerial performed during the quarterfinal, semifinal, and final heats from the 11 events in the 2015 season was viewed. From this, 121 aerials were identified with the Frontside Air (n = 15) and Frontside Air Reverse (n = 67) being selected to be qualitatively assessed. Using chi-squared analyses, a series of key critical features, including landing over the center of the surfboard (FS Air χ 2  = 14.00, FS Air Reverse χ 2  = 26.61; P < .001) and landing with the lead ankle in dorsiflexion (FS Air χ 2  = 3.90, FS Air Reverse χ 2  = 13.64; P < .05), were found to be associated with successful landings. These critical features help surfers land in a stable position, while maintaining contact with the surfboard. The results of this study provide coaches with evidence to adjust the technique of their athletes to improve their winning potential. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

SURF Model Calibration Strategy

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

Menikoff, Ralph

2017-03-10

SURF and SURFplus are high explosive reactive burn models for shock initiation and propagation of detonation waves. They are engineering models motivated by the ignition & growth concept of high spots and for SURFplus a second slow reaction for the energy release from carbon clustering. A key feature of the SURF model is that there is a partial decoupling between model parameters and detonation properties. This enables reduced sets of independent parameters to be calibrated sequentially for the initiation and propagation regimes. Here we focus on a methodology for tting the initiation parameters to Pop plot data based on 1-Dmore » simulations to compute a numerical Pop plot. In addition, the strategy for tting the remaining parameters for the propagation regime and failure diameter is discussed.« less

Wave Dissipation over Nearshore Beach Morphology: Insights from High-Resolution LIDAR Observations and the SWASH Wave Model

NASA Astrophysics Data System (ADS)

Mulligan, R. P.; Gomes, E.; McNinch, J.; Brodie, K. L.

2016-02-01

Numerical modelling of the nearshore zone can be computationally intensive due to the complexity of wave breaking, and the need for high temporal and spatial resolution. In this study we apply the SWASH non-hydrostatic wave-flow model that phase-resolves the free surface and fluid motions in the water column at high resolution. The model is forced using observed directional energy spectra, and results are compared to wave observations during moderate storm events. Observations are collected outside the surf zone using acoustic wave and currents sensors, and inside the surf zone over a 100 m transect using high-resolution LIDAR measurements of the sea surface from a sensor mounted on a tower on the beach dune at the Field Research Facility in Duck, NC. The model is applied to four cases with different wave conditions and bathymetry, and used to predict the spatial variability in wave breaking, and correlation between energy dissipation and morphologic features. Model results compare well with observations of spectral evolution outside the surf zone, and with the remotely sensed observations of wave transformation inside the surf zone. The results indicate the importance of nearshore bars, rip-channels, and larger features (major scour depression under the pier following large waves from Hurricane Irene) on the location of wave breaking and alongshore variability in wave energy dissipation.

Movements of wintering surf scoters: Predator responses to different prey landscapes

USGS Publications Warehouse

Kirk, M.; Esler, Daniel N.; Iverson, S.A.; Boyd, W.S.

2008-01-01

The distribution of predators is widely recognized to be intimately linked to the distribution of their prey. Foraging theory suggests that predators will modify their behaviors, including movements, to optimize net energy intake when faced with variation in prey attributes or abundance. While many studies have documented changes in movement patterns of animals in response to temporal changes in food, very few have contrasted movements of a single predator species naturally occurring in dramatically different prey landscapes. We documented variation in the winter movements, foraging range size, site fidelity, and distribution patterns of a molluscivorous sea duck, the surf scoter (Melanitta perspicillata), in two areas of coastal British Columbia with very different shellfish prey features. Baynes Sound has extensive tidal flats with abundant clams, which are high-quality and temporally stable prey for scoters. Malaspina Inlet is a rocky fjord-like inlet where scoters consume mussels that are superabundant and easily accessible in some patches but are heavily depleted over the course of winter. We used radio telemetry to track surf scoter movements in both areas and found that in the clam habitats of Baynes Sound, surf scoters exhibited limited movement, small winter ranges, strong foraging site fidelity, and very consistent distribution patterns. By contrast, in mussel habitats in the Malaspina Inlet, surf scoters displayed more movement, larger ranges, little fidelity to specific foraging sites, and more variable distribution patterns. We conclude that features associated with the different prey types, particularly the higher depletion rates of mussels, strongly influenced seasonal space use patterns. These findings are consistent with foraging theory and confirm that predator behavior, specifically movements, is environmentally mediated. ?? 2008 Springer-Verlag.

Shock Detector for SURF model

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

Menikoff, Ralph

2016-01-11

SURF and its extension SURFplus are reactive burn models aimed at shock initiation and propagation of detonation waves in high explosives. A distinctive feature of these models is that the burn rate depends on the lead shock pressure. A key part of the models is an algorithm to detect the lead shock. Typically, shock capturing hydro algorithms have small oscillations behind a shock. Here we investigate how well the shock detection algorithm works for a nearly steady propagating detonation wave in one-dimension using the Eulerian xRage code.

Deep Learning for Lowtextured Image Matching

NASA Astrophysics Data System (ADS)

Kniaz, V. V.; Fedorenko, V. V.; Fomin, N. A.

2018-05-01

Low-textured objects pose challenges for an automatic 3D model reconstruction. Such objects are common in archeological applications of photogrammetry. Most of the common feature point descriptors fail to match local patches in featureless regions of an object. Hence, automatic documentation of the archeological process using Structure from Motion (SfM) methods is challenging. Nevertheless, such documentation is possible with the aid of a human operator. Deep learning-based descriptors have outperformed most of common feature point descriptors recently. This paper is focused on the development of a new Wide Image Zone Adaptive Robust feature Descriptor (WIZARD) based on the deep learning. We use a convolutional auto-encoder to compress discriminative features of a local path into a descriptor code. We build a codebook to perform point matching on multiple images. The matching is performed using the nearest neighbor search and a modified voting algorithm. We present a new "Multi-view Amphora" (Amphora) dataset for evaluation of point matching algorithms. The dataset includes images of an Ancient Greek vase found at Taman Peninsula in Southern Russia. The dataset provides color images, a ground truth 3D model, and a ground truth optical flow. We evaluated the WIZARD descriptor on the "Amphora" dataset to show that it outperforms the SIFT and SURF descriptors on the complex patch pairs.

Rotation invariant fast features for large-scale recognition

NASA Astrophysics Data System (ADS)

Takacs, Gabriel; Chandrasekhar, Vijay; Tsai, Sam; Chen, David; Grzeszczuk, Radek; Girod, Bernd

2012-10-01

We present an end-to-end feature description pipeline which uses a novel interest point detector and Rotation- Invariant Fast Feature (RIFF) descriptors. The proposed RIFF algorithm is 15× faster than SURF1 while producing large-scale retrieval results that are comparable to SIFT.2 Such high-speed features benefit a range of applications from Mobile Augmented Reality (MAR) to web-scale image retrieval and analysis.

Robust pedestrian detection and tracking from a moving vehicle

NASA Astrophysics Data System (ADS)

Tuong, Nguyen Xuan; Müller, Thomas; Knoll, Alois

2011-01-01

In this paper, we address the problem of multi-person detection, tracking and distance estimation in a complex scenario using multi-cameras. Specifically, we are interested in a vision system for supporting the driver in avoiding any unwanted collision with the pedestrian. We propose an approach using Histograms of Oriented Gradients (HOG) to detect pedestrians on static images and a particle filter as a robust tracking technique to follow targets from frame to frame. Because the depth map requires expensive computation, we extract depth information of targets using Direct Linear Transformation (DLT) to reconstruct 3D-coordinates of correspondent points found by running Speeded Up Robust Features (SURF) on two input images. Using the particle filter the proposed tracker can efficiently handle target occlusions in a simple background environment. However, to achieve reliable performance in complex scenarios with frequent target occlusions and complex cluttered background, results from the detection module are integrated to create feedback and recover the tracker from tracking failures due to the complexity of the environment and target appearance model variability. The proposed approach is evaluated on different data sets both in a simple background scenario and a cluttered background environment. The result shows that, by integrating detector and tracker, a reliable and stable performance is possible even if occlusion occurs frequently in highly complex environment. A vision-based collision avoidance system for an intelligent car, as a result, can be achieved.

An anti-disturbing real time pose estimation method and system

NASA Astrophysics Data System (ADS)

Zhou, Jian; Zhang, Xiao-hu

2011-08-01

Pose estimation relating two-dimensional (2D) images to three-dimensional (3D) rigid object need some known features to track. In practice, there are many algorithms which perform this task in high accuracy, but all of these algorithms suffer from features lost. This paper investigated the pose estimation when numbers of known features or even all of them were invisible. Firstly, known features were tracked to calculate pose in the current and the next image. Secondly, some unknown but good features to track were automatically detected in the current and the next image. Thirdly, those unknown features which were on the rigid and could match each other in the two images were retained. Because of the motion characteristic of the rigid object, the 3D information of those unknown features on the rigid could be solved by the rigid object's pose at the two moment and their 2D information in the two images except only two case: the first one was that both camera and object have no relative motion and camera parameter such as focus length, principle point, and etc. have no change at the two moment; the second one was that there was no shared scene or no matched feature in the two image. Finally, because those unknown features at the first time were known now, pose estimation could go on in the followed images in spite of the missing of known features in the beginning by repeating the process mentioned above. The robustness of pose estimation by different features detection algorithms such as Kanade-Lucas-Tomasi (KLT) feature, Scale Invariant Feature Transform (SIFT) and Speed Up Robust Feature (SURF) were compared and the compact of the different relative motion between camera and the rigid object were discussed in this paper. Graphic Processing Unit (GPU) parallel computing was also used to extract and to match hundreds of features for real time pose estimation which was hard to work on Central Processing Unit (CPU). Compared with other pose estimation methods, this new method can estimate pose between camera and object when part even all known features are lost, and has a quick response time benefit from GPU parallel computing. The method present here can be used widely in vision-guide techniques to strengthen its intelligence and generalization, which can also play an important role in autonomous navigation and positioning, robots fields at unknown environment. The results of simulation and experiments demonstrate that proposed method could suppress noise effectively, extracted features robustly, and achieve the real time need. Theory analysis and experiment shows the method is reasonable and efficient.

Performance analysis of a multispectral framing camera for detecting mines in the littoral zone and beach zone

NASA Astrophysics Data System (ADS)

Louchard, Eric; Farm, Brian; Acker, Andrew

2008-04-01

BAE Systems Sensor Systems Identification & Surveillance (IS) has developed, under contract with the Office of Naval Research, a multispectral airborne sensor system and processing algorithms capable of detecting mine-like objects in the surf zone and land mines in the beach zone. BAE Systems has used this system in a blind test at a test range established by the Naval Surface Warfare Center - Panama City Division (NSWC-PCD) at Eglin Air Force Base. The airborne and ground subsystems used in this test are described, with graphical illustrations of the detection algorithms. We report on the performance of the system configured to operate with a human operator analyzing data on a ground station. A subsurface (underwater bottom proud mine in the surf zone and moored mine in shallow water) mine detection capability is demonstrated in the surf zone. Surface float detection and proud land mine detection capability is also demonstrated. Our analysis shows that this BAE Systems-developed multispectral airborne sensor provides a robust technical foundation for a viable system for mine counter-measures, and would be a valuable asset for use prior to an amphibious assault.

Nontraumatic Myelopathy Associated With Surfing

PubMed Central

Avilés-Hernández, Israel; García-Zozaya, Inigo; DeVillasante, Jorge M

2007-01-01

Background/Objective: Ischemic nontraumatic spinal cord injury associated with surfing is a novel diagnosis believed to be related to prolonged spine hyperextension while lying prone on the surfboard. Only 9 cases have been documented. This report features possible risk factors, etiology, diagnostic imaging, and outcomes of surfer's myelopathy. Design: Case report. Results: A 37-year-old man developed T11 American Spinal Injury Association (ASIA) A paraplegia shortly after surfing. The clinical history and magnetic resonance imaging findings were compatible with an ischemic insult to the distal thoracic spinal cord. Our patient did not have any of the proposed risk factors associated with this condition, and, contrary to most reports, he sustained a complete spinal cord lesion without neurological recovery by 8 weeks post injury. Conclusions: Surfer's myelopathy, because of its proposed mechanism of injury, is amenable to medical intervention. Increased awareness of this condition may lead to early recognition and treatment, which should contribute to improved neurological outcomes. PMID:17684897

A novel point cloud registration using 2D image features

NASA Astrophysics Data System (ADS)

Lin, Chien-Chou; Tai, Yen-Chou; Lee, Jhong-Jin; Chen, Yong-Sheng

2017-01-01

Since a 3D scanner only captures a scene of a 3D object at a time, a 3D registration for multi-scene is the key issue of 3D modeling. This paper presents a novel and an efficient 3D registration method based on 2D local feature matching. The proposed method transforms the point clouds into 2D bearing angle images and then uses the 2D feature based matching method, SURF, to find matching pixel pairs between two images. The corresponding points of 3D point clouds can be obtained by those pixel pairs. Since the corresponding pairs are sorted by their distance between matching features, only the top half of the corresponding pairs are used to find the optimal rotation matrix by the least squares approximation. In this paper, the optimal rotation matrix is derived by orthogonal Procrustes method (SVD-based approach). Therefore, the 3D model of an object can be reconstructed by aligning those point clouds with the optimal transformation matrix. Experimental results show that the accuracy of the proposed method is close to the ICP, but the computation cost is reduced significantly. The performance is six times faster than the generalized-ICP algorithm. Furthermore, while the ICP requires high alignment similarity of two scenes, the proposed method is robust to a larger difference of viewing angle.

Ranking Highlights in Personal Videos by Analyzing Edited Videos.

PubMed

Sun, Min; Farhadi, Ali; Chen, Tseng-Hung; Seitz, Steve

2016-11-01

We present a fully automatic system for ranking domain-specific highlights in unconstrained personal videos by analyzing online edited videos. A novel latent linear ranking model is proposed to handle noisy training data harvested online. Specifically, given a targeted domain such as "surfing," our system mines the YouTube database to find pairs of raw and their corresponding edited videos. Leveraging the assumption that an edited video is more likely to contain highlights than the trimmed parts of the raw video, we obtain pair-wise ranking constraints to train our model. The learning task is challenging due to the amount of noise and variation in the mined data. Hence, a latent loss function is incorporated to mitigate the issues caused by the noise. We efficiently learn the latent model on a large number of videos (about 870 min in total) using a novel EM-like procedure. Our latent ranking model outperforms its classification counterpart and is fairly competitive compared with a fully supervised ranking system that requires labels from Amazon Mechanical Turk. We further show that a state-of-the-art audio feature mel-frequency cepstral coefficients is inferior to a state-of-the-art visual feature. By combining both audio-visual features, we obtain the best performance in dog activity, surfing, skating, and viral video domains. Finally, we show that impressive highlights can be detected without additional human supervision for seven domains (i.e., skating, surfing, skiing, gymnastics, parkour, dog activity, and viral video) in unconstrained personal videos.

Automated ortho-rectification of UAV-based hyperspectral data over an agricultural field using frame RGB imagery

DOE PAGES

Habib, Ayman; Han, Youkyung; Xiong, Weifeng; ...

2016-09-24

Low-cost Unmanned Airborne Vehicles (UAVs) equipped with consumer-grade imaging systems have emerged as a potential remote sensing platform that could satisfy the needs of a wide range of civilian applications. Among these applications, UAV-based agricultural mapping and monitoring have attracted significant attention from both the research and professional communities. The interest in UAV-based remote sensing for agricultural management is motivated by the need to maximize crop yield. Remote sensing-based crop yield prediction and estimation are primarily based on imaging systems with different spectral coverage and resolution (e.g., RGB and hyperspectral imaging systems). Due to the data volume, RGB imaging ismore » based on frame cameras, while hyperspectral sensors are primarily push-broom scanners. To cope with the limited endurance and payload constraints of low-cost UAVs, the agricultural research and professional communities have to rely on consumer-grade and light-weight sensors. However, the geometric fidelity of derived information from push-broom hyperspectral scanners is quite sensitive to the available position and orientation established through a direct geo-referencing unit onboard the imaging platform (i.e., an integrated Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS). This paper presents an automated framework for the integration of frame RGB images, push-broom hyperspectral scanner data and consumer-grade GNSS/INS navigation data for accurate geometric rectification of the hyperspectral scenes. The approach relies on utilizing the navigation data, together with a modified Speeded-Up Robust Feature (SURF) detector and descriptor, for automating the identification of conjugate features in the RGB and hyperspectral imagery. The SURF modification takes into consideration the available direct geo-referencing information to improve the reliability of the matching procedure in the presence of repetitive texture within a mechanized agricultural field. Identified features are then used to improve the geometric fidelity of the previously ortho-rectified hyperspectral data. Lastly, experimental results from two real datasets show that the geometric rectification of the hyperspectral data was improved by almost one order of magnitude.« less

Automated ortho-rectification of UAV-based hyperspectral data over an agricultural field using frame RGB imagery

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

Habib, Ayman; Han, Youkyung; Xiong, Weifeng

Low-cost Unmanned Airborne Vehicles (UAVs) equipped with consumer-grade imaging systems have emerged as a potential remote sensing platform that could satisfy the needs of a wide range of civilian applications. Among these applications, UAV-based agricultural mapping and monitoring have attracted significant attention from both the research and professional communities. The interest in UAV-based remote sensing for agricultural management is motivated by the need to maximize crop yield. Remote sensing-based crop yield prediction and estimation are primarily based on imaging systems with different spectral coverage and resolution (e.g., RGB and hyperspectral imaging systems). Due to the data volume, RGB imaging ismore » based on frame cameras, while hyperspectral sensors are primarily push-broom scanners. To cope with the limited endurance and payload constraints of low-cost UAVs, the agricultural research and professional communities have to rely on consumer-grade and light-weight sensors. However, the geometric fidelity of derived information from push-broom hyperspectral scanners is quite sensitive to the available position and orientation established through a direct geo-referencing unit onboard the imaging platform (i.e., an integrated Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS). This paper presents an automated framework for the integration of frame RGB images, push-broom hyperspectral scanner data and consumer-grade GNSS/INS navigation data for accurate geometric rectification of the hyperspectral scenes. The approach relies on utilizing the navigation data, together with a modified Speeded-Up Robust Feature (SURF) detector and descriptor, for automating the identification of conjugate features in the RGB and hyperspectral imagery. The SURF modification takes into consideration the available direct geo-referencing information to improve the reliability of the matching procedure in the presence of repetitive texture within a mechanized agricultural field. Identified features are then used to improve the geometric fidelity of the previously ortho-rectified hyperspectral data. Lastly, experimental results from two real datasets show that the geometric rectification of the hyperspectral data was improved by almost one order of magnitude.« less

A Learning Based Fiducial-driven Registration Scheme for Evaluating Laser Ablation Changes in Neurological Disorders.

PubMed

Wan, Tao; Bloch, B Nicolas; Danish, Shabbar; Madabhushi, Anant

2014-11-20

In this work, we present a novel learning based fiducial driven registration (LeFiR) scheme which utilizes a point matching technique to identify the optimal configuration of landmarks to better recover deformation between a target and a moving image. Moreover, we employ the LeFiR scheme to model the localized nature of deformation introduced by a new treatment modality - laser induced interstitial thermal therapy (LITT) for treating neurological disorders. Magnetic resonance (MR) guided LITT has recently emerged as a minimally invasive alternative to craniotomy for local treatment of brain diseases (such as glioblastoma multiforme (GBM), epilepsy). However, LITT is currently only practised as an investigational procedure world-wide due to lack of data on longer term patient outcome following LITT. There is thus a need to quantitatively evaluate treatment related changes between post- and pre-LITT in terms of MR imaging markers. In order to validate LeFiR, we tested the scheme on a synthetic brain dataset (SBD) and in two real clinical scenarios for treating GBM and epilepsy with LITT. Four experiments under different deformation profiles simulating localized ablation effects of LITT on MRI were conducted on 286 pairs of SBD images. The training landmark configurations were obtained through 2000 iterations of registration where the points with consistently best registration performance were selected. The estimated landmarks greatly improved the quality metrics compared to a uniform grid (UniG) placement scheme, a speeded-up robust features (SURF) based method, and a scale-invariant feature transform (SIFT) based method as well as a generic free-form deformation (FFD) approach. The LeFiR method achieved average 90% improvement in recovering the local deformation compared to 82% for the uniform grid placement, 62% for the SURF based approach, and 16% for the generic FFD approach. On the real GBM and epilepsy data, the quantitative results showed that LeFiR outperformed UniG by 28% improvement in average.

Nearshore shore-oblique bars, gravel outcrops, and their correlation to shoreline change

USGS Publications Warehouse

Schupp, C.A.; McNinch, J.E.; List, J.H.

2006-01-01

This study demonstrates the physical concurrence of shore-oblique bars and gravel outcrops in the surf zone along the northern Outer Banks of North Carolina. These subaqueous features are spatially correlated with shoreline change at a range of temporal and spatial scales. Previous studies have noted the existence of beach-surf zone interactions, but in general, relationships between nearshore geological features and coastal change are poorly understood. These new findings should be considered when exploring coastal zone dynamics and developing predictive engineering models.The surf zone and nearshore region of the Outer Banks is predominantly planar and sandy, but there are several discrete regions with shore-oblique bars and interspersed gravel outcrops. These bar fields have relief up to 3 m, are several kilometers wide, and were relatively stationary over a 1.5 year survey period; however, the shoreward component of the bar field does exhibit change during this time frame. All gravel outcrops observed in the study region, a 40 km longshore length, were located adjacent to a shore-oblique bar, in a trough that had width and length similar to that of the associated bar. Seismic surveys show that the outcrops are part of a gravel stratum underlying the active surface sand layer.Cross-correlation analyses demonstrate high correlation of monthly and multi-decadal shoreline change rates with the adjacent surf-zone bathymetry and sediment distribution. Regionally, areas with shore-oblique bars and gravel outcrops are correlated with on-shore areas of high short-term shoreline variability and high long-term shoreline change rates. The major peaks in long-term shoreline erosion are onshore of shore-oblique bars, but not all areas with high rates of long-term shoreline change are associated with shore-oblique bars and troughs.

Identification and location of catenary insulator in complex background based on machine vision

NASA Astrophysics Data System (ADS)

Yao, Xiaotong; Pan, Yingli; Liu, Li; Cheng, Xiao

2018-04-01

It is an important premise to locate insulator precisely for fault detection. Current location algorithms for insulator under catenary checking images are not accurate, a target recognition and localization method based on binocular vision combined with SURF features is proposed. First of all, because of the location of the insulator in complex environment, using SURF features to achieve the coarse positioning of target recognition; then Using binocular vision principle to calculate the 3D coordinates of the object which has been coarsely located, realization of target object recognition and fine location; Finally, Finally, the key is to preserve the 3D coordinate of the object's center of mass, transfer to the inspection robot to control the detection position of the robot. Experimental results demonstrate that the proposed method has better recognition efficiency and accuracy, can successfully identify the target and has a define application value.

Future treatments for Parkinson's disease: surfing the PD pipeline.

PubMed

Hauser, Robert A

2011-01-01

Our current wish list for the treatment of Parkinson's disease (PD) includes therapies that will provide robust and sustained antiparkinsonian benefit through the day, ameliorate or prevent dyskinesia, and slow or prevent the progression of the disease. In this article, I review selected new therapies in clinical development for motor features or treatment complications of PD, and some that may slow disease progression. These include adenosine 2a (A2a) antagonists (istradefylline, preladenant, and SYN115), levodopa/carbidopa intestinal gel (LCIG), IPX066--an extended-release formulation of carbidopa/levodopa, XP21279--a sustained-release levodopa prodrug, ND0611--a carbidopa subcutaneous patch, safinamide--a mixed mechanism of action medication that may provide both MAO-B and glutamate inhibition, PMY50028--an oral neurotrophic factor inducer, antidyskinesia medications (AFQ056 and fipamezole), and gene therapies (AAV2-neurturin and glutamic acid decarboxylase gene transfer). Some of these therapies will never be proven efficacious and will not come to market while others may play a key role in the future treatment of PD.

Synchrotron radiation calibration of the EUVE variable line-spaced diffraction gratings at the NBS SURF II facility

NASA Technical Reports Server (NTRS)

Jelinsky, P.; Jelinsky, S. R.; Miller, A.; Vallerga, J.; Malina, R. F.

1988-01-01

The Extreme Ultraviolet Explorer (EUVE) has a spectrometer which utilizes variable line-spaced, plane diffraction gratings in the converging beam of a Wolter-Schwarzschild type II mirror. The gratings, microchannel plate detector, and thin film filters have been calibrated with continuum radiation provided by the NBS SURF II facility. These were calibrated in a continuum beam to find edges or other sharp spectral features in the transmission of the filters, quantum efficiency of the microchannel plate detector, and efficiency of the gratings. The details of the calibration procedure and the results of the calibration are presented.

ConSurf 2016: an improved methodology to estimate and visualize evolutionary conservation in macromolecules

PubMed Central

Ashkenazy, Haim; Abadi, Shiran; Martz, Eric; Chay, Ofer; Mayrose, Itay; Pupko, Tal; Ben-Tal, Nir

2016-01-01

The degree of evolutionary conservation of an amino acid in a protein or a nucleic acid in DNA/RNA reflects a balance between its natural tendency to mutate and the overall need to retain the structural integrity and function of the macromolecule. The ConSurf web server (http://consurf.tau.ac.il), established over 15 years ago, analyses the evolutionary pattern of the amino/nucleic acids of the macromolecule to reveal regions that are important for structure and/or function. Starting from a query sequence or structure, the server automatically collects homologues, infers their multiple sequence alignment and reconstructs a phylogenetic tree that reflects their evolutionary relations. These data are then used, within a probabilistic framework, to estimate the evolutionary rates of each sequence position. Here we introduce several new features into ConSurf, including automatic selection of the best evolutionary model used to infer the rates, the ability to homology-model query proteins, prediction of the secondary structure of query RNA molecules from sequence, the ability to view the biological assembly of a query (in addition to the single chain), mapping of the conservation grades onto 2D RNA models and an advanced view of the phylogenetic tree that enables interactively rerunning ConSurf with the taxa of a sub-tree. PMID:27166375

Maternal segmental disomy in Leigh syndrome with cytochrome c oxidase deficiency caused by homozygous SURF1 mutation.

PubMed

van Riesen, A K J; Antonicka, H; Ohlenbusch, A; Shoubridge, E A; Wilichowski, E K G

2006-04-01

Cytochrome c oxidase deficiency (COX) is the most frequent cause of Leigh syndrome (LS), a mitochondrial subacute necrotizing encephalomyelopathy. Most of these LS (COX-) patients show mutations in SURF1 on chromosome 9 (9q34), which encodes a protein essential for the assembly of the COX complex. We describe a family whose first-born boy developed characteristic features of LS. Severe COX deficiency in muscle was caused by a novel homozygous nonsense mutation in SURF1. Segregation analysis of this mutation in the family was incompatible with autosomal recessive inheritance but consistent with a maternal disomy. Haplotype analysis of microsatellite markers confirmed isodisomy involving nearly the complete long arm of chromosome 9 (9q21-9tel). No additional physical abnormalities were present in the boy, suggesting that there are no imprinted genes on the long arm of chromosome 9 which are crucial for developmental processes. This case of segmental isodisomy illustrates that genotyping of parents is crucial for correct genetic counseling.

The Effect of a Single Bout of Surfing on Exercise-Induced Affect.

PubMed

Pittsinger, Ryan; Kress, Jeff; Crussemeyer, Jill

2017-01-01

Exercise-induced affect (EIA) has been well documented and is often composed of positive affect, negative affect, tranquility, and fatigue. Research on EIA has focused on mainstream sports such as running, walking, or cycling; however, no research has evaluated the influence of action sports participation in activities such surfing on EIA. The current study examined the effect of a single 30-min surfing bout on EIA in 107 adult volunteers. An additional purpose was if change in affect was similar based on surfing history, surfing frequency, and surfing skill level. To assess EIA, each participant completed the Physical Activity Affect Scale (PAAS) prior to and immediately following the 30-min surf session. Dependent t -tests were used to examine differences between pre- and post-test EIA. For the secondary purpose, a change score (PAAS posttest-PAAS pretest) was computed for each subscale. One-way ANOVAs were performed to determine differences among comparisons of surfing history, surfing frequency, and surfing skill level, and the change score for each of the 4 subscales. EIA was significantly altered by surfing, with significant improvements in positive affect and tranquility, and significant reductions in negative affect and fatigue. There were no significant differences among surfing history, surfing frequency, and surfing skill level, and positive affect, negative affect or tranquility. However, there were significant differences between fatigue and surfing history, surfing frequency, and surfing skill level. The results indicate that a single 30-min surfing bout may provide positive benefits for the participant. Implications for future surfing research and EIA are discussed.

The Effect of a Single Bout of Surfing on Exercise-Induced Affect

PubMed Central

PITTSINGER, RYAN; KRESS, JEFF; CRUSSEMEYER, JILL

2017-01-01

Exercise-induced affect (EIA) has been well documented and is often composed of positive affect, negative affect, tranquility, and fatigue. Research on EIA has focused on mainstream sports such as running, walking, or cycling; however, no research has evaluated the influence of action sports participation in activities such surfing on EIA. The current study examined the effect of a single 30-min surfing bout on EIA in 107 adult volunteers. An additional purpose was if change in affect was similar based on surfing history, surfing frequency, and surfing skill level. To assess EIA, each participant completed the Physical Activity Affect Scale (PAAS) prior to and immediately following the 30-min surf session. Dependent t-tests were used to examine differences between pre- and post-test EIA. For the secondary purpose, a change score (PAAS posttest-PAAS pretest) was computed for each subscale. One-way ANOVAs were performed to determine differences among comparisons of surfing history, surfing frequency, and surfing skill level, and the change score for each of the 4 subscales. EIA was significantly altered by surfing, with significant improvements in positive affect and tranquility, and significant reductions in negative affect and fatigue. There were no significant differences among surfing history, surfing frequency, and surfing skill level, and positive affect, negative affect or tranquility. However, there were significant differences between fatigue and surfing history, surfing frequency, and surfing skill level. The results indicate that a single 30-min surfing bout may provide positive benefits for the participant. Implications for future surfing research and EIA are discussed. PMID:29170700

Integral Images: Efficient Algorithms for Their Computation and Storage in Resource-Constrained Embedded Vision Systems

PubMed Central

Ehsan, Shoaib; Clark, Adrian F.; ur Rehman, Naveed; McDonald-Maier, Klaus D.

2015-01-01

The integral image, an intermediate image representation, has found extensive use in multi-scale local feature detection algorithms, such as Speeded-Up Robust Features (SURF), allowing fast computation of rectangular features at constant speed, independent of filter size. For resource-constrained real-time embedded vision systems, computation and storage of integral image presents several design challenges due to strict timing and hardware limitations. Although calculation of the integral image only consists of simple addition operations, the total number of operations is large owing to the generally large size of image data. Recursive equations allow substantial decrease in the number of operations but require calculation in a serial fashion. This paper presents two new hardware algorithms that are based on the decomposition of these recursive equations, allowing calculation of up to four integral image values in a row-parallel way without significantly increasing the number of operations. An efficient design strategy is also proposed for a parallel integral image computation unit to reduce the size of the required internal memory (nearly 35% for common HD video). Addressing the storage problem of integral image in embedded vision systems, the paper presents two algorithms which allow substantial decrease (at least 44.44%) in the memory requirements. Finally, the paper provides a case study that highlights the utility of the proposed architectures in embedded vision systems. PMID:26184211

Integral Images: Efficient Algorithms for Their Computation and Storage in Resource-Constrained Embedded Vision Systems.

PubMed

Ehsan, Shoaib; Clark, Adrian F; Naveed ur Rehman; McDonald-Maier, Klaus D

2015-07-10

The integral image, an intermediate image representation, has found extensive use in multi-scale local feature detection algorithms, such as Speeded-Up Robust Features (SURF), allowing fast computation of rectangular features at constant speed, independent of filter size. For resource-constrained real-time embedded vision systems, computation and storage of integral image presents several design challenges due to strict timing and hardware limitations. Although calculation of the integral image only consists of simple addition operations, the total number of operations is large owing to the generally large size of image data. Recursive equations allow substantial decrease in the number of operations but require calculation in a serial fashion. This paper presents two new hardware algorithms that are based on the decomposition of these recursive equations, allowing calculation of up to four integral image values in a row-parallel way without significantly increasing the number of operations. An efficient design strategy is also proposed for a parallel integral image computation unit to reduce the size of the required internal memory (nearly 35% for common HD video). Addressing the storage problem of integral image in embedded vision systems, the paper presents two algorithms which allow substantial decrease (at least 44.44%) in the memory requirements. Finally, the paper provides a case study that highlights the utility of the proposed architectures in embedded vision systems.

Taking Wave Prediction to New Levels: Wavewatch 3

DTIC Science & Technology

2016-01-01

features such as surf and rip currents , conditions that affect special operations, amphibious assaults, and logistics over the shore. Changes in...The Navy’s current version of WAVEWATCH Ill features the capability of operating with gridded domains of multiple resolution simultaneously, ranging...Netherlands. Its current form, WAVEWATCH Ill, was developed at NOAA’s National Center for Environmental Prediction. The model is free and open source

On the influence of reflection over a rhythmic swash zone on surf zone dynamics

NASA Astrophysics Data System (ADS)

Almar, Rafael; Nicolae Lerma, Alexandre; Castelle, Bruno; Scott, Timothy

2018-05-01

The reflection of incident gravity waves over an irregular swash zone morphology and the resulting influence on surf zone dynamics remains mostly unexplored. The wave-phase resolving SWASH model is applied to investigate this feedback using realistic low-tide terraced beach morphology with well-developed beach cusps. The rhythmic reflection generates a standing wave that mimics a subharmonic edge wave, from the superimposition of incident and two-dimensional reflected waves. This mechanism is enhanced by shore-normal, narrow-banded waves in both direction and frequency. Our study suggests that wave reflection over steep beaches could be a mechanism for the development of rhythmic morphological features such as beach cusps and rip currents.

Determination of feature generation methods for PTZ camera object tracking

NASA Astrophysics Data System (ADS)

Doyle, Daniel D.; Black, Jonathan T.

2012-06-01

Object detection and tracking using computer vision (CV) techniques have been widely applied to sensor fusion applications. Many papers continue to be written that speed up performance and increase learning of artificially intelligent systems through improved algorithms, workload distribution, and information fusion. Military application of real-time tracking systems is becoming more and more complex with an ever increasing need of fusion and CV techniques to actively track and control dynamic systems. Examples include the use of metrology systems for tracking and measuring micro air vehicles (MAVs) and autonomous navigation systems for controlling MAVs. This paper seeks to contribute to the determination of select tracking algorithms that best track a moving object using a pan/tilt/zoom (PTZ) camera applicable to both of the examples presented. The select feature generation algorithms compared in this paper are the trained Scale-Invariant Feature Transform (SIFT) and Speeded Up Robust Features (SURF), the Mixture of Gaussians (MoG) background subtraction method, the Lucas- Kanade optical flow method (2000) and the Farneback optical flow method (2003). The matching algorithm used in this paper for the trained feature generation algorithms is the Fast Library for Approximate Nearest Neighbors (FLANN). The BSD licensed OpenCV library is used extensively to demonstrate the viability of each algorithm and its performance. Initial testing is performed on a sequence of images using a stationary camera. Further testing is performed on a sequence of images such that the PTZ camera is moving in order to capture the moving object. Comparisons are made based upon accuracy, speed and memory.

Image feature detection and extraction techniques performance evaluation for development of panorama under different light conditions

NASA Astrophysics Data System (ADS)

Patil, Venkat P.; Gohatre, Umakant B.

2018-04-01

The technique of obtaining a wider field-of-view of an image to get high resolution integrated image is normally required for development of panorama of a photographic images or scene from a sequence of part of multiple views. There are various image stitching methods developed recently. For image stitching five basic steps are adopted stitching which are Feature detection and extraction, Image registration, computing homography, image warping and Blending. This paper provides review of some of the existing available image feature detection and extraction techniques and image stitching algorithms by categorizing them into several methods. For each category, the basic concepts are first described and later on the necessary modifications made to the fundamental concepts by different researchers are elaborated. This paper also highlights about the some of the fundamental techniques for the process of photographic image feature detection and extraction methods under various illumination conditions. The Importance of Image stitching is applicable in the various fields such as medical imaging, astrophotography and computer vision. For comparing performance evaluation of the techniques used for image features detection three methods are considered i.e. ORB, SURF, HESSIAN and time required for input images feature detection is measured. Results obtained finally concludes that for daylight condition, ORB algorithm found better due to the fact that less tome is required for more features extracted where as for images under night light condition it shows that SURF detector performs better than ORB/HESSIAN detectors.

Facial dysmorphism in Leigh syndrome with SURF-1 mutation and COX deficiency.

PubMed

Yüksel, Adnan; Seven, Mehmet; Cetincelik, Umran; Yeşil, Gözde; Köksal, Vedat

2006-06-01

Leigh syndrome is an inherited, progressive neurodegenerative disorder of infancy and childhood. Mutations in the nuclear SURF-1 gene are specifically associated with cytochrome C oxidase-deficient Leigh syndrome. This report describes two patients with similar facial features. One of them was a 2(1/2)-year-old male, and the other was a 3-year-old male with a mutation in SURF-1 gene and facial dysmorphism including frontal bossing, brachycephaly, hypertrichosis, lateral displacement of inner canthi, esotropia, maxillary hypoplasia, hypertrophic gums, irregularly placed teeth, upturned nostril, low-set big ears, and retrognathi. The first patient's magnetic resonance imaging at 15 months of age indicated mild symmetric T2 prolongation involving the subthalamic nuclei. His second magnetic resonance imaging at 2 years old revealed a symmetric T2 prolongation involving the subthalamic nuclei, substantia nigra, and medulla lesions. In the second child, at the age of 2 the first magnetic resonance imaging documented heavy brainstem and subthalamic nuclei involvement. A second magnetic resonance imaging, performed when he was 3 years old, revealed diffuse involvement of the substantia nigra and hyperintense lesions of the central tegmental tract in addition to previous lesions. Facial dysmorphism and magnetic resonance imaging findings, observed in these cases, can be specific findings in Leigh syndrome patients with cytochrome C oxidase deficiency. SURF-1 gene mutations must be particularly reviewed in such patients.

Shear-wave velocity model from Rayleigh wave group velocities centered on the Sacramento/San Joaquin Delta

USGS Publications Warehouse

Fletcher, Jon Peter B.; Erdem, Jemile

2017-01-01

Rayleigh wave group velocities obtained from ambient noise tomography are inverted for an upper crustal model of the Central Valley, California, centered on the Sacramento/San Joaquin Delta. Two methods were tried; the first uses SURF96, a least-squares routine. It provides a good fit to the data, but convergence is dependent on the starting model. The second uses a genetic algorithm, whose starting model is random. This method was tried at several nodes in the model and compared to the output from SURF96. The genetic code is run five times and the variance of the output of all five models can be used to obtain an estimate of error. SURF96 produces a more regular solution mostly because it is typically run with a smoothing constraint. Models from the genetic code are generally consistent with the SURF96 code sometimes producing lower velocities at depth. The full model, calculated using SURF96, employed a 2-pass strategy, which used a variable damping scheme in the first pass. The resulting model shows low velocities near the surface in the Central Valley with a broad asymmetrical sedimentary basin located close to the western edge of the Central Valley near 122°W longitude. At shallow depths the Rio Vista Basin is found nestled between the Pittsburgh/Kirby Hills and Midland faults, but a significant basin also seems to exist to the west of the Kirby Hills fault. There are other possible correlations between fast and slow velocities in the Central Valley and geologic features such as the Stockton Arch, oil or gas producing regions and the fault-controlled western boundary of the Central Valley.

Shear-wave Velocity Model from Rayleigh Wave Group Velocities Centered on the Sacramento/San Joaquin Delta

NASA Astrophysics Data System (ADS)

Fletcher, Jon B.; Erdem, Jemile

2017-10-01

Rayleigh wave group velocities obtained from ambient noise tomography are inverted for an upper crustal model of the Central Valley, California, centered on the Sacramento/San Joaquin Delta. Two methods were tried; the first uses SURF96, a least squares routine. It provides a good fit to the data, but convergence is dependent on the starting model. The second uses a genetic algorithm, whose starting model is random. This method was tried at several nodes in the model and compared to the output from SURF96. The genetic code is run five times and the variance of the output of all five models can be used to obtain an estimate of error. SURF96 produces a more regular solution mostly because it is typically run with a smoothing constraint. Models from the genetic code are generally consistent with the SURF96 code sometimes producing lower velocities at depth. The full model, calculated using SURF96, employed a 2-pass strategy, which used a variable damping scheme in the first pass. The resulting model shows low velocities near the surface in the Central Valley with a broad asymmetrical sedimentary basin located close to the western edge of the Central Valley near 122°W longitude. At shallow depths, the Rio Vista Basin is found nestled between the Pittsburgh/Kirby Hills and Midland faults, but a significant basin also seems to exist to the west of the Kirby Hills fault. There are other possible correlations between fast and slow velocities in the Central Valley and geologic features such as the Stockton Arch, oil or gas producing regions and the fault-controlled western boundary of the Central Valley.

Littoral assessment of mine burial signatures (LAMBS): buried landmine/background spectral-signature analyses

NASA Astrophysics Data System (ADS)

Kenton, Arthur C.; Geci, Duane M.; Ray, Kristofer J.; Thomas, Clayton M.; Salisbury, John W.; Mars, John C.; Crowley, James K.; Witherspoon, Ned H.; Holloway, John H., Jr.

2004-09-01

The objective of the Office of Naval Research (ONR) Rapid Overt Reconnaissance (ROR) program and the Airborne Littoral Reconnaissance Technologies (ALRT) project's LAMBS effort is to determine if electro-optical spectral discriminants exist that are useful for the detection of land mines in littoral regions. Statistically significant buried mine overburden and background signature data were collected over a wide spectral range (0.35 to 14 μm) to identify robust spectral features that might serve as discriminants for new airborne sensor concepts. LAMBS has expanded previously collected databases to littoral areas - primarily dry and wet sandy soils - where tidal, surf, and wind conditions can severely modify spectral signatures. At AeroSense 2003, we reported completion of three buried mine collections at an inland bay, Atlantic and Gulf of Mexico beach sites. We now report LAMBS spectral database analyses results using metrics which characterize the detection performance of general types of spectral detection algorithms. These metrics include mean contrast, spectral signal-to-clutter, covariance, information content, and spectral matched filter analyses. Detection performance of the buried land mines was analyzed with regard to burial age, background type, and environmental conditions. These analyses considered features observed due to particle size differences, surface roughness, surface moisture, and compositional differences.

Littoral Assessment of Mine Burial Signatures (LAMBS) buried land mine/background spectral signature analyses

USGS Publications Warehouse

Kenton, A.C.; Geci, D.M.; Ray, K.J.; Thomas, C.M.; Salisbury, J.W.; Mars, J.C.; Crowley, J.K.; Witherspoon, N.H.; Holloway, J.H.; Harmon R.S.Broach J.T.Holloway, Jr. J.H.

2004-01-01

The objective of the Office of Naval Research (ONR) Rapid Overt Reconnaissance (ROR) program and the Airborne Littoral Reconnaissance Technologies (ALRT) project's LAMBS effort is to determine if electro-optical spectral discriminants exist that are useful for the detection of land mines in littoral regions. Statistically significant buried mine overburden and background signature data were collected over a wide spectral range (0.35 to 14 ??m) to identify robust spectral features that might serve as discriminants for new airborne sensor concepts. LAMBS has expanded previously collected databases to littoral areas - primarily dry and wet sandy soils - where tidal, surf, and wind conditions can severely modify spectral signatures. At AeroSense 2003, we reported completion of three buried mine collections at an inland bay, Atlantic and Gulf of Mexico beach sites.1 We now report LAMBS spectral database analyses results using metrics which characterize the detection performance of general types of spectral detection algorithms. These metrics include mean contrast, spectral signal-to-clutter, covariance, information content, and spectral matched filter analyses. Detection performance of the buried land mines was analyzed with regard to burial age, background type, and environmental conditions. These analyses considered features observed due to particle size differences, surface roughness, surface moisture, and compositional differences.

Modification of the Undertow and Turbulence by Submerged Vegetation in a Laboratory Surf Zone

NASA Astrophysics Data System (ADS)

Mandel, T.; Suckale, J.; Marras, S.; Maldonado, S.; Koseff, J. R.

2016-12-01

Breaking waves in the surf zone are a dominant factor shaping the evolution of our coastlines. The turbulence generated by wave breaking causes sediment resuspension, while wave runup, rundown, and the undertow transport this sediment along and across the shore (Longo et al., 2002). Coastal hazard models must now address the added complications of climate change, including sea level rise, stronger storm events, and ecosystem degradation (Arkema et al., 2013). A robust theoretical understanding of surf zone dynamics is therefore imperative to considering the magnitude and implications of these potential changes. However, little work has been done to extend our current theoretical understanding to realistic beach faces, with aquatic vegetation, reefs, and other roughness elements that might mitigate scour and sedimentation. Clarifying these relationships will help scientists and policy-makers decide where to focus ecosystem restoration and preservation efforts, in order to maximize their protective benefits to infrastructure and economic activity on the coast. In order to evaluate the role of vegetation in coastal protection, we conducted a series of experiments in an idealized laboratory surf zone. We examine the impact of submerged model vegetation on the undertow profile, wave orbital velocities, turbulent kinetic energy, and wave-induced stresses, and compare these results to theoretical formulations that model these quantities. We find that vegetation reduces the wave energy available to be converted to turbulent kinetic energy during breaking, indicating a mechanism to mitigate suspension of sediment. Vegetation also reduces the magnitude of the undertow, likely reducing transport of sediment offshore. These results suggest that vegetation provides significant protective benefits for coastal communities at risk from erosion beyond its well-characterized ability to attenuate wave height, and motivate further work to incorporate these effects into models of near-shore hydrodynamics. Longo S, Petti M, Losada IJ. 2002. Turbulence in the swash and surf zones: a review. Coast Eng 45:129-147. Arkema KK, Guannel G, Verutes G, Wood SA, Guerry A, Ruckelshaus M, Kareiva P, Lacayo M, Silver JM. Coastal habitats shield people and property from sea-level rise and storms. Nat Clim Change 3:913-918.

A fast and mobile system for registration of low-altitude visual and thermal aerial images using multiple small-scale UAVs

NASA Astrophysics Data System (ADS)

Yahyanejad, Saeed; Rinner, Bernhard

2015-06-01

The use of multiple small-scale UAVs to support first responders in disaster management has become popular because of their speed and low deployment costs. We exploit such UAVs to perform real-time monitoring of target areas by fusing individual images captured from heterogeneous aerial sensors. Many approaches have already been presented to register images from homogeneous sensors. These methods have demonstrated robustness against scale, rotation and illumination variations and can also cope with limited overlap among individual images. In this paper we focus on thermal and visual image registration and propose different methods to improve the quality of interspectral registration for the purpose of real-time monitoring and mobile mapping. Images captured by low-altitude UAVs represent a very challenging scenario for interspectral registration due to the strong variations in overlap, scale, rotation, point of view and structure of such scenes. Furthermore, these small-scale UAVs have limited processing and communication power. The contributions of this paper include (i) the introduction of a feature descriptor for robustly identifying corresponding regions of images in different spectrums, (ii) the registration of image mosaics, and (iii) the registration of depth maps. We evaluated the first method using a test data set consisting of 84 image pairs. In all instances our approach combined with SIFT or SURF feature-based registration was superior to the standard versions. Although we focus mainly on aerial imagery, our evaluation shows that the presented approach would also be beneficial in other scenarios such as surveillance and human detection. Furthermore, we demonstrated the advantages of the other two methods in case of multiple image pairs.

Stereo Refractive Imaging of Breaking Free-Surface Waves in the Surf Zone

NASA Astrophysics Data System (ADS)

Mandel, Tracy; Weitzman, Joel; Koseff, Jeffrey; Environmental Fluid Mechanics Laboratory Team

2014-11-01

Ocean waves drive the evolution of coastlines across the globe. Wave breaking suspends sediments, while wave run-up, run-down, and the undertow transport this sediment across the shore. Complex bathymetric features and natural biotic communities can influence all of these dynamics, and provide protection against erosion and flooding. However, our knowledge of the exact mechanisms by which this occurs, and how they can be modeled and parameterized, is limited. We have conducted a series of controlled laboratory experiments with the goal of elucidating these details. These have focused on quantifying the spatially-varying characteristics of breaking waves and developing more accurate techniques for measuring and predicting wave setup, setdown, and run-up. Using dynamic refraction stereo imaging, data on free-surface slope and height can be obtained over an entire plane. Wave evolution is thus obtained with high spatial precision. These surface features are compared with measures of instantaneous turbulence and mean currents within the water column. We then use this newly-developed ability to resolve three-dimensional surface features over a canopy of seagrass mimics, in order to validate theoretical formulations of wave-vegetation interactions in the surf zone.

Platforms for hyperspectral imaging, in-situ optical and acoustical imaging in urbanized regions

NASA Astrophysics Data System (ADS)

Bostater, Charles R.; Oney, Taylor

2016-10-01

Hyperspectral measurements of the water surface of urban coastal waters are presented. Oblique bidirectional reflectance factor imagery was acquired made in a turbid coastal sub estuary of the Indian River Lagoon, Florida and along coastal surf zone waters of the nearby Atlantic Ocean. Imagery was also collected using a pushbroom hyperspectral imager mounted on a fixed platform with a calibrated circular mechatronic rotation stage. Oblique imagery of the shoreline and subsurface features clearly shows subsurface bottom features and rip current features within the surf zone water column. In-situ hyperspectral optical signatures were acquired from a vessel as a function of depth to determine the attenuation spectrum in Palm Bay. A unique stationary platform methodology to acquire subsurface acoustic images showing the presence of moving bottom boundary nephelometric layers passing through the acoustic fan beam. The acoustic fan beam imagery indicated the presence of oscillatory subsurface waves in the urbanized coastal estuary. Hyperspectral imaging using the fixed platform techniques are being used to collect hyperspectral bidirectional reflectance factor (BRF) measurements from locations at buildings and bridges in order to provide new opportunities to advance our scientific understanding of aquatic environments in urbanized regions.

Pathogenicity of missense mutations in SURF1 deficiency inducing the Leigh syndrome. Importance in diagnosis.

PubMed

Dubot, A; Hervouet, E; Mandon, G; Zabot, M T; Godinot, C

2004-06-01

Leigh syndrome with cytochrome oxidase (COX) deficiency has been associated with SURF1 mutations. For patient diagnosis, distinction between neutral polymorphisms and pathogenic missense SURF1 mutations in Leigh syndrome is essential. We show that several missense SURF1 mutations did not allow a stable protein to be expressed. Absence of immunologically reactive SURF1 is, therefore, helpful to demonstrate their pathogenicity. In addition, we show that out of two previously described missense mutations housed by the same allele, only one, the T737 C was pathogenic. Indeed, transfection of T737 C mutated SURF1 in SURF1-deficient cells did not restore normal SURF1 stability and COX activity. On the contrary, the G604 C-mutated SURF1 did it and, hence, is a neutral variant.

Characterization of Activity and Cardiovascular Responses During Surfing in Recreational Male Surfers Between the Ages of 18 and 75 Years Old.

PubMed

LaLanne, Christine L; Cannady, Michael S; Moon, Joseph F; Taylor, Danica L; Nessler, Jeff A; Crocker, George H; Newcomer, Sean C

2017-04-01

Participation in surfing has evolved to include all age groups. Therefore, the purpose of this study was to determine whether activity levels and cardiovascular responses to surfing change with age. Surfing time and heart rate (HR) were measured for the total surfing session and within each activity of surfing (paddling, sitting, wave riding, and miscellaneous). Peak oxygen consumption (VO 2peak ) was also measured during laboratory-based simulated surfboard paddling on a modified swim bench ergometer. VO 2peak decreased with age during simulated paddling (r = -.455, p < .001, n = 68). Total time surfing (p = .837) and time spent within each activity of surfing did not differ with age (n = 160). Mean HR during surfing significantly decreased with age (r = -.231, p = .004). However, surfing HR expressed as a percent of age-predicted maximum increased significantly with age. Therefore, recreational surfers across the age spectrum are achieving intensities and durations that are consistent with guidelines for cardiovascular health.

Planktonic Subsidies to Surf-Zone and Intertidal Communities

NASA Astrophysics Data System (ADS)

Morgan, Steven G.; Shanks, Alan L.; MacMahan, Jamie H.; Reniers, Ad J. H. M.; Feddersen, Falk

2018-01-01

Plankton are transported onshore, providing subsidies of food and new recruits to surf-zone and intertidal communities. The transport of plankton to the surf zone is influenced by wind, wave, and tidal forcing, and whether they enter the surf zone depends on alongshore variation in surf-zone hydrodynamics caused by the interaction of breaking waves with coastal morphology. Areas with gently sloping shores and wide surf zones typically have orders-of-magnitude-higher concentrations of plankton in the surf zone and dense larval settlement in intertidal communities because of the presence of bathymetric rip currents, which are absent in areas with steep shores and narrow surf zones. These striking differences in subsidies have profound consequences; areas with greater subsidies support more productive surf-zone communities and possibly more productive rocky intertidal communities. Recognition of the importance of spatial subsidies for rocky community dynamics has recently advanced ecological theory, and incorporating surf-zone hydrodynamics would be an especially fruitful line of investigation.

The nucleolar protein SURF-6 is essential for viability in mouse NIH/3T3 cells.

PubMed

Polzikov, Mikhail; Magoulas, Charalambos; Zatsepina, Olga

2007-09-01

SURF-6 is a bona fide nucleolar protein comprising an evolutionary conserved family that extends from human to yeast. The expression of the mammalian SURF-6 has been recently found to be regulated during the cell cycle. In order to determine the importance of SURF-6 in mammalian cells, we applied the Tet-On system to regulate conditionally, in response to tetracycline, the expression of an antisense RNA (asRNA) that targets Surf-6 mRNA in mouse NIH/3T3 cells. Induced Surf-6 asRNA caused an effective depletion of SURF-6 protein resulted in cell death and in an apparent arrest in the G1 phase of the cell cycle. These results provide for the first time evidence that expression of SURF-6 is essential for mammalian cell viability, and suggest that SURF-6 might participate in the progression of cell cycle.

Neural network-based feature point descriptors for registration of optical and SAR images

NASA Astrophysics Data System (ADS)

Abulkhanov, Dmitry; Konovalenko, Ivan; Nikolaev, Dmitry; Savchik, Alexey; Shvets, Evgeny; Sidorchuk, Dmitry

2018-04-01

Registration of images of different nature is an important technique used in image fusion, change detection, efficient information representation and other problems of computer vision. Solving this task using feature-based approaches is usually more complex than registration of several optical images because traditional feature descriptors (SIFT, SURF, etc.) perform poorly when images have different nature. In this paper we consider the problem of registration of SAR and optical images. We train neural network to build feature point descriptors and use RANSAC algorithm to align found matches. Experimental results are presented that confirm the method's effectiveness.

Architecture of Pd-Au bimetallic nanoparticles in sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles as investigated by X-ray absorption spectroscopy.

PubMed

Chen, Ching-Hsiang; Sarma, Loka Subramanyam; Chen, Jium-Ming; Shih, Shou-Chu; Wang, Guo-Rung; Liu, Din-Goa; Tang, Mau-Tsu; Lee, Jyh-Fu; Hwang, Bing-Joe

2007-09-01

In this study, we demonstrate the unique application of X-ray absorption spectroscopy (XAS) as a fundamental characterization tool to help in designing and controlling the architecture of Pd-Au bimetallic nanoparticles within a water-in-oil microemulsion system of water/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/n-heptane. Structural insights obtained from the in situ XAS measurements recorded at each step during the formation process revealed that Pd-Au bimetallic clusters with various Pd-Au atomic stackings are formed by properly performing hydrazine reduction and redox transmetalation reactions sequentially within water-in-oil microemulsions. A structural model is provided to explain reasonably each reaction step and to give detailed insight into the nucleation and growth mechanism of Pd-Au bimetallic clusters. The combination of in situ XAS analysis at both the Pd K-edge and the Au L(III)-edge and UV-vis absorption spectral features confirms that the formation of Pd-Au bimetallic clusters follows a (Pd(nuclei)-Au(stack))-Pd(surf) stacking. This result further implies that the thickness of Au(stack) and Pd(surf) layers may be modulated by varying the dosage of the Au precursor and hydrazine, respectively. In addition, a bimetallic (Pd-Au)(alloy) nanocluster with a (Pd(nuclei)-Au(stack))-(Pd-Au(alloy))(surf) stacking was also designed and synthesized in order to check the feasibility of Pd(surf) layer modification. The result reveals that the Pd(surf) layer of the stacked (Pd(nuclei)-Au)(stack) bimetallic clusters can be successfully modified to form a (Au-Pd alloy)(surf) layer by a co-reduction of Pd and Au ions by hydrazine. Further, we demonstrate the alloying extent or atomic distribution of Pd and Au in Pd-Au bimetallic nanoparticles from the derived XAS structural parameters. The complete XAS-based methodology, demonstrated here on the Pd-Au bimetallic system, can easily be extended to design and control the alloying extent or atomic distribution, atomic stacking, and electronic structure to construct many other types of bimetallic systems for interesting applications.

50 CFR 648.72 - Minimum surf clam size.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.72 Minimum surf clam size. (a) Minimum length. The minimum length for surf clams is 4.75 inches (12.065 cm). (b) Determination of compliance. No more than 50... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Minimum surf clam size. 648.72 Section 648...

Study on the traditional pattern retrieval method of minorities in Gansu province

NASA Astrophysics Data System (ADS)

Zheng, Gang; Wang, Beizhan; Sun, Yuchun; Xu, Jin

2018-03-01

The traditional patterns of ethnic minorities in gansu province are ethnic arts with strong ethnic characteristics. It is the crystallization of the hard work and wisdom of minority nationalities in gansu province. Unique traditional patterns of ethnic minorities in Gansu province with rich ethnic folk arts, is the crystallization of geographical environment in Gansu minority diligence and wisdom. By using the Surf feature point identification algorithm, the feature point extractor in OpenCV is used to extract the feature points. And the feature points are applied to compare the pattern features to find patterns similar to the artistic features. The application of this method can quickly or efficiently extract pattern information in a database.

Climatic impact on community of filamentous macroalgae in the Neva estuary (eastern Baltic Sea).

PubMed

Gubelit, Yulia I

2015-02-15

In presented study the impact of climatic factors and North Atlantic Oscillation (NAO) on macroalgal community was analysed. Also the factors influencing algal community were defined with help of Principal Component and Classification analysis. It was found that climatic impact may depend on habitat features and that on different sites biomass of macroalgae correlated with different weather factors. Wind and surf may affect biomass of macroalgae adversely on some sites and at the same time on other sites they may accumulate biomass, transferring it is from adjacent areas. High direct correlation with temperature was found on sites which were protected from surf and had no stagnant events. Seasonal biomass inversely significantly correlated with average seasonal wind speed and annual NAO-index. Copyright © 2014 Elsevier Ltd. All rights reserved.

Information surfing with the JHU/APL coherent imager

NASA Astrophysics Data System (ADS)

Ratto, Christopher R.; Shipley, Kara R.; Beagley, Nathaniel; Wolfe, Kevin C.

2015-05-01

The ability to perform remote forensics in situ is an important application of autonomous undersea vehicles (AUVs). Forensics objectives may include remediation of mines and/or unexploded ordnance, as well as monitoring of seafloor infrastructure. At JHU/APL, digital holography is being explored for the potential application to underwater imaging and integration with an AUV. In previous work, a feature-based approach was developed for processing the holographic imagery and performing object recognition. In this work, the results of the image processing method were incorporated into a Bayesian framework for autonomous path planning referred to as information surfing. The framework was derived assuming that the location of the object of interest is known a priori, but the type of object and its pose are unknown. The path-planning algorithm adaptively modifies the trajectory of the sensing platform based on historical performance of object and pose classification. The algorithm is called information surfing because the direction of motion is governed by the local information gradient. Simulation experiments were carried out using holographic imagery collected from submerged objects. The autonomous sensing algorithm was compared to a deterministic sensing CONOPS, and demonstrated improved accuracy and faster convergence in several cases.

Vision Based SLAM in Dynamic Scenes

DTIC Science & Technology

2012-12-20

the correct relative poses between cameras at frame F. For this purpose, we detect and match SURF features between cameras in dilierent groups, and...all cameras in s uch a challenging case. For a compa rison, we disabled the ’ inte r-camera pose estimation’ and applied the ’ intra-camera pose esti

Surf Reports reported to the Hawaiian Forecast Office

Science.gov Websites

CONTROLLED. Surf Reports from Kauai RSS Feed LOCATION TIME SURF HEIGHT DIR PER REMARKS Kee Haena 130 PM 2-4 RSS Feed LOCATION TIME SURF HEIGHT DIR PER WIND REMARKS Diamond Head Waikiki 315 PM 2-3 NE 10-15 from Maui RSS Feed LOCATION TIME SURF HEIGHT DIR WIND REMARKS Kanaha Baldwin Shor 1035 AM 2-3 NE 10-15

Inner Surf/Swash Zone Morphodynamic Numerical Model Simulation of an Accreting Ridge during Low-Energy Wave Conditions

NASA Astrophysics Data System (ADS)

Song, Youn Kyung; Figlus, Jens; Chardón-Maldonado, Patricia; Puleo, Jack A.

2017-04-01

The inner surf/swash zone of a coastal beach is characterized as an intermittently wet and dry zone in the nearshore that often develops a variety of morphological features including intertidal bars and ridge-runnel (RR) systems. The cross-shore morphodynamic numerical model CSHORE is used to simulate the beach recovery observed during a field experiment carried out at South Bethany Beach, Delaware, a nourished, high-gradient meso-tidal sandy beach along the U. S. Coast. The field campaign was conducted from February 12 to February 25, 2014 to measure bed profile morphology change and sediment characteristics along with detailed hydrodynamic forcing parameters at six cross-shore stations, closely spaced over approximately 50 m in the inner surf and swash zone. On February 13, 2014 a Nor'easter eroded significant portions of the beach leading to formation of a pronounced RR system on the beach face that subsequently accreted in the recovery process after the storm. Bed profile changes, surf and swash velocity profiles, water free surface elevation and suspended sediment concentrations recorded during the recovery at the cross-shore measuring locations on the seaward face of the accreting ridge are compared with CSHORE simulation results. During post-storm recovery, CSHORE demonstrates shoreward migration of the ridge and slight accretion on the beach face by the end of the simulation period on February 25, 2014. This trend was also observed in the field, where accretion at the ridge crest was up to 1.0 m with respect to the post-storm profile. The CSHORE parameters critical to improving model performance in reproducing measured morphodynamics and hydrodynamics during the ridge accretion process are examined and calibrated. Initial results show promise in using this type of efficient, process-based model to reproduce morphological evolution and depth-averaged hydrodynamics as a result of the complex surf and swash zone dynamics associated with beach accretion and RR system mobilization.

Real-time human versus animal classification using pyro-electric sensor array and Hidden Markov Model

NASA Astrophysics Data System (ADS)

Hossen, Jakir; Jacobs, Eddie L.; Chari, Srikant

2014-03-01

In this paper, we propose a real-time human versus animal classification technique using a pyro-electric sensor array and Hidden Markov Model. The technique starts with the variational energy functional level set segmentation technique to separate the object from background. After segmentation, we convert the segmented object to a signal by considering column-wise pixel values and then finding the wavelet coefficients of the signal. HMMs are trained to statistically model the wavelet features of individuals through an expectation-maximization learning process. Human versus animal classifications are made by evaluating a set of new wavelet feature data against the trained HMMs using the maximum-likelihood criterion. Human and animal data acquired-using a pyro-electric sensor in different terrains are used for performance evaluation of the algorithms. Failures of the computationally effective SURF feature based approach that we develop in our previous research are because of distorted images produced when the object runs very fast or if the temperature difference between target and background is not sufficient to accurately profile the object. We show that wavelet based HMMs work well for handling some of the distorted profiles in the data set. Further, HMM achieves improved classification rate over the SURF algorithm with almost the same computational time.

Remote sensing of the correlation between breakpoint oscillations and infragravity waves in the surf and swash zone

NASA Astrophysics Data System (ADS)

Moura, T.; Baldock, T. E.

2017-04-01

A novel remote sensing methodology to determine the dominant infragravity mechanism in the inner surf and swash zone in the field is presented. Video observations of the breakpoint motion are correlated with the shoreline motion and inner surf zone water levels to determine the relationship between the time-varying breakpoint oscillations and the shoreline motion. The results of 13 field data sets collected from three different beaches indicate that, inside the surf zone, the dominance of bound wave or breakpoint forcing is strongly dependent on the surf zone width and the type of short wave breaking. Infragravity generation by bound wave release was stronger for conditions with relatively narrow surf zones and plunging waves; breakpoint forcing was dominant for wider surf zones and spilling breaker conditions.

Sequence conservation from human to prokaryotes of Surf1, a protein involved in cytochrome c oxidase assembly, deficient in Leigh syndrome.

PubMed

Poyau, A; Buchet, K; Godinot, C

1999-12-03

The human SURF1 gene encoding a protein involved in cytochrome c oxidase (COX) assembly, is mutated in most patients presenting Leigh syndrome associated with COX deficiency. Proteins homologous to the human Surf1 have been identified in nine eukaryotes and six prokaryotes using database alignment tools, structure prediction and/or cDNA sequencing. Their sequence comparison revealed a remarkable Surf1 conservation during evolution and put forward at least four highly conserved domains that should be essential for Surf1 function. In Paracoccus denitrificans, the Surf1 homologue is found in the quinol oxidase operon, suggesting that Surf1 is associated with a primitive quinol oxidase which belongs to the same superfamily as cytochrome oxidase.

Performance Analysis of Surfing: A Review.

PubMed

Farley, Oliver R L; Abbiss, Chris R; Sheppard, Jeremy M

2017-01-01

Farley, ORL, Abbiss, CR, and Sheppard, JM. Performance Analysis of Surfing: A Review. J Strength Cond Res 31(1): 260-271, 2017-Despite the increased professionalism and substantial growth of surfing worldwide, there is limited information available to practitioners and coaches in terms of key performance analytics that are common in other field-based sports. Indeed, research analyzing surfing performance is limited to a few studies examining male surfers' heart rates, surfing activities through time-motion analysis (TMA) using video recordings and Global Positioning Satellite (GPS) data during competition and recreational surfing. These studies have indicated that specific activities undertaken during surfing are unique with a variety of activities (i.e., paddling, resting, wave riding, breath holding, and recovery of surfboard in the surf). Furthermore, environmental and wave conditions also seem to influence the physical demands of competition surfing. It is due to these demands that surfers are required to have a high cardiorespiratory fitness, high muscular endurance, and considerable strength and anaerobic power, particular within the upper torso. By exploring various methods of performance analysis used within other sports, it is possible to improve our understanding of surfing demands. In so doing this will assist in the development of protocols and strategies to assess physiological characteristics of surfers, monitor athlete performance, improve training prescription, and identify talent. Therefore, this review explores the current literature to provide insights into methodological protocols, delimitations of research into athlete analysis and an overview of surfing dynamics. Specifically, this review will describe and review the use of TMA, GPS, and other technologies (i.e., HR) that are used in external and internal load monitoring as they pertain to surfing.

Neurological injuries from car surfing.

PubMed

Wang, Arthur; Cohen, Alan R; Robinson, Shenandoah

2009-11-01

Trauma secondary to car surfing is a unique mechanism of head and spinal injury in children and adolescents. In this study, the authors present their experience with neurological injuries resulting from car surfing and describe the growing national trend of car-surfing injuries and the increasing portrayal of this activity in the media. A retrospective study of the Rainbow Babies and Children's Hospital trauma database was conducted to identify all cases of neurological injuries secondary to car surfing. Between January 1995 and December 2008, 7 patients

Surfing the web and parkinson's law.

PubMed

Baldwin, F D

1996-05-01

The World Wide Web accounts for much of the popular interest in the Internet and offers a rich and variegated source of medical information. It's where you'll find online attractions ranging from "The Visible Human" to collections of lawyer jokes, as well as guides to clinical materials. Here's a basic introduction to the Web, its features, and its vocabulary.

Prevalence of Pterygia in Hawaii: Examining Cumulative Surfing Hours as a Risk Factor.

PubMed

Lin, Alexander D; Miles, Ku'ulei; Brinks, Mitchel V

2016-08-01

To examine the association between surfing and pterygium prevalence in Hawaii. A convenience sampling was performed at four beaches on the island of Oahu, Hawaii. A total of 169 individuals were interviewed and underwent penlight examination to assess grade and extent of pterygium. Of 169 participants aged 18-80 years, 88 non-surfers, 41 occasional surfers, 15 recreational surfers and 25 surfing enthusiasts were identified based on their lifetime surfing hours. Overall, 19 participants were found to have pterygia (28 pterygia total) including two non-surfers (2.3%), five occasional surfers (12.2%), three recreational surfers (20.0%), and nine enthusiast surfers (36.0%). Variables associated with pterygium prevalence were lifetime surfing hours (p < 0.0001), outdoor occupation (p = 0.04), Hawaiian residence (p = 0.009), and Hawaiian/Pacific Islander ethnicity (p = 0.002). Multiple logistic regression with the outcome of pterygium was performed, along with multiple linear regression for the continuous outcomes of corneal extent, chord length, and apex-visual axis gap, with lifetime surfing hours as the primary explanatory variable. After adjustment for confounders, a significant linear relationship was observed between chord length and lifetime surfing hours (p = 0.01). Surfing was associated with an increased pterygium prevalence and trend towards an association with increased pterygium severity. Increased risk of exposure to wind, particle irritation, and ultraviolet (UV) radiation while surfing may contribute to pterygium development. Implications for public health include promoting UV protective eyewear during surfing, in addition to raising awareness about the association of pterygia and the sport of surfing.

The greenscape shapes surfing of resource waves in a large migratory herbivore

USGS Publications Warehouse

Aikens, Ellen O.; Kauffman, Matthew J.; Merkle, Jerod A.; Dwinnell, Samantha P.H.; Fralick, Gary L.; Monteith, Kevin L.

2017-01-01

The Green Wave Hypothesis posits that herbivore migration manifests in response to waves of spring green-up (i.e. green-wave surfing). Nonetheless, empirical support for the Green Wave Hypothesis is mixed, and a framework for understanding variation in surfing is lacking. In a population of migratory mule deer (Odocoileus hemionus), 31% surfed plant phenology in spring as well as a theoretically perfect surfer, and 98% surfed better than random. Green-wave surfing varied among individuals and was unrelated to age or energetic state. Instead, the greenscape, which we define as the order, rate and duration of green-up along migratory routes, was the primary factor influencing surfing. Our results indicate that migratory routes are more than a link between seasonal ranges, and they provide an important, but often overlooked, foraging habitat. In addition, the spatiotemporal configuration of forage resources that propagate along migratory routes shape animal movement and presumably, energy gains during migration.

Scale invariant SURF detector and automatic clustering segmentation for infrared small targets detection

NASA Astrophysics Data System (ADS)

Zhang, Haiying; Bai, Jiaojiao; Li, Zhengjie; Liu, Yan; Liu, Kunhong

2017-06-01

The detection and discrimination of infrared small dim targets is a challenge in automatic target recognition (ATR), because there is no salient information of size, shape and texture. Many researchers focus on mining more discriminative information of targets in temporal-spatial. However, such information may not be available with the change of imaging environments, and the targets size and intensity keep changing in different imaging distance. So in this paper, we propose a novel research scheme using density-based clustering and backtracking strategy. In this scheme, the speeded up robust feature (SURF) detector is applied to capture candidate targets in single frame at first. And then, these points are mapped into one frame, so that target traces form a local aggregation pattern. In order to isolate the targets from noises, a newly proposed density-based clustering algorithm, fast search and find of density peak (FSFDP for short), is employed to cluster targets by the spatial intensive distribution. Two important factors of the algorithm, percent and γ , are exploited fully to determine the clustering scale automatically, so as to extract the trace with highest clutter suppression ratio. And at the final step, a backtracking algorithm is designed to detect and discriminate target trace as well as to eliminate clutter. The consistence and continuity of the short-time target trajectory in temporal-spatial is incorporated into the bounding function to speed up the pruning. Compared with several state-of-arts methods, our algorithm is more effective for the dim targets with lower signal-to clutter ratio (SCR). Furthermore, it avoids constructing the candidate target trajectory searching space, so its time complexity is limited to a polynomial level. The extensive experimental results show that it has superior performance in probability of detection (Pd) and false alarm suppressing rate aiming at variety of complex backgrounds.

Surfing wave climate variability

NASA Astrophysics Data System (ADS)

Espejo, Antonio; Losada, Iñigo J.; Méndez, Fernando J.

2014-10-01

International surfing destinations are highly dependent on specific combinations of wind-wave formation, thermal conditions and local bathymetry. Surf quality depends on a vast number of geophysical variables, and analyses of surf quality require the consideration of the seasonal, interannual and long-term variability of surf conditions on a global scale. A multivariable standardized index based on expert judgment is proposed for this purpose. This index makes it possible to analyze surf conditions objectively over a global domain. A summary of global surf resources based on a new index integrating existing wave, wind, tides and sea surface temperature databases is presented. According to general atmospheric circulation and swell propagation patterns, results show that west-facing low to middle-latitude coasts are more suitable for surfing, especially those in the Southern Hemisphere. Month-to-month analysis reveals strong seasonal variations in the occurrence of surfable events, enhancing the frequency of such events in the North Atlantic and the North Pacific. Interannual variability was investigated by comparing occurrence values with global and regional modes of low-frequency climate variability such as El Niño and the North Atlantic Oscillation, revealing their strong influence at both the global and the regional scale. Results of the long-term trends demonstrate an increase in the probability of surfable events on west-facing coasts around the world in recent years. The resulting maps provide useful information for surfers, the surf tourism industry and surf-related coastal planners and stakeholders.

Habitat use by larval fishes in a temperate South African surf zone

NASA Astrophysics Data System (ADS)

Watt-Pringle, Peter; Strydom, Nadine A.

2003-12-01

Larval fishes were sampled in the Kwaaihoek surf zone on the south east coast of South Africa. On six occasions between February and May 2002, larval fishes were collected in two habitat types identified in the inner surf zone using a modified beach-seine net. The surf zone habitats were classified as either sheltered trough areas or adjacent exposed surf areas. Temperature, depth and current measurements were taken at all sites. Trough habitats consisted of a depression in surf topography characterised by reduced current velocities and greater average depth than adjacent surf areas. In total, 325 larval fishes were collected. Of these, 229 were collected in trough and 96 in surf habitats. At least 22 families and 37 species were represented in the catch. Dominant families were the Mugilidae, Sparidae, Atherinidae, and Engraulidae. Dominant species included Liza tricuspidens and Liza richardsonii (Mugilidae), Rhabdosargus holubi and Sarpa salpa (Sparidae), Atherina breviceps (Atherinidae) and Engraulis japonicus (Engraulide). Mean CPUE of postflexion larvae of estuary-dependent species was significantly greater in trough areas. The proportion of postflexion larval fishes in trough habitat was significantly greater than that of preflexion stages, a result that was not apparent in surf habitat sampled. CPUE of postflexion larvae of estuary-dependent fishes was negatively correlated with current magnitude and positively correlated with habitat depth. Mean body length of larval fishes was significantly greater in trough than in surf habitats. These results provide evidence that the CPUE of postflexion larvae of estuary-dependent fishes is higher in trough habitat in the surf zone and this may be indicative of active habitat selection for areas of reduced current velocity/wave action. The implications of this behaviour for estuarine recruitment processes are discussed.

Delineation of surf scoter habitat in Chesapeake Bay, Maryland: macrobenthic and sediment composition of surf scoter feeding sites

USGS Publications Warehouse

Kidwell, D.M.; Perry, M.C.

2005-01-01

Surveys of surf scoters (Melanitta perspicillata) along the Atlantic coast of the United States have shown population declines in recent decades. The Chesapeake Bay has traditionally been a key wintering area for surf scoters. Past and present research has shown that bivalves constitute a major food item for seaducks in the Chesapeake Bay, with surf scoters feeding primarily on hooked mussel (Ischadium recurvum) and dwarf surf clam (Mulinia lateralis). Degraded water quality conditions in the Chesapeake Bay have been well documented and have been shown to greatly influence the composition of benthic communities. Large concentrations of feeding surf scoters (>500 individuals) in the Bay were determined through monthly boat surveys. Locations consistently lacking surf scoters were also determined. Macrobenthos were seasonally sampled at 3 locations containing scoters and 3 locations without scoters. A 1 kilometer square grid was superimposed over each location using GIS and sampling sites within the square were randomly chosen. Benthos were sampled at each site using SCUBA and a meter square quadrat. Biomass and size class estimates were determined for all bivalves within each kilometer square. Results indicated that scoter feeding sites contained significantly greater biomass of M. lateralis, I. recurvum, and Gemma gemma than locations where no scoters were present. Substrate differences were also detected, with scoter feeding sites being composed of a sand/shell mix while non-scoter sites consisted primarily of mud. This data indicates that surf scoters in the Chesapeake Bay are selecting areas with high densities of preferred food items, potentially maximizing there foraging energetics. In addition, two scoter feeding sites also contained a patchwork of eastern oyster (Crassostrea virginica) and oyster shell, on which much of the I. recurvum was attached. This suggests the possibility that surf scoters utilize eastern oyster habitat and the dramatic depletion of oysters in the Bay could be a possible factor in surf scoter decline. More research is needed into the possible relationship between surf scoters and the eastern oyster.

76 FR 8651 - Special Local Regulation; Mavericks Surf Competition, Half Moon Bay, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

...-AA08 Special Local Regulation; Mavericks Surf Competition, Half Moon Bay, CA AGENCY: Coast Guard, DHS... regulation on certain navigable waters of Half Moon Bay in support of the Mavericks Surf Competition. This...,000 yard radius of Pillar Point in Half Moon Bay. The Mavericks Surf Competition will occur in the...

Survival of mutations arising during invasions.

PubMed

Miller, Judith R

2010-03-01

When a neutral mutation arises in an invading population, it quickly either dies out or 'surfs', i.e. it comes to occupy almost all the habitat available at its time of origin. Beneficial mutations can also surf, as can deleterious mutations over finite time spans. We develop descriptive statistical models that quantify the relationship between the probability that a mutation will surf and demographic parameters for a cellular automaton model of surfing. We also provide a simple analytic model that performs well at predicting the probability of surfing for neutral and beneficial mutations in one dimension. The results suggest that factors - possibly including even abiotic factors - that promote invasion success may also increase the probability of surfing and associated adaptive genetic change, conditioned on such success.

Safe trajectory estimation at a pedestrian crossing to assist visually impaired people.

PubMed

Alghamdi, Saleh; van Schyndel, Ron; Khalil, Ibrahim

2012-01-01

The aim of this paper is to present a service for blind and people with low vision to assist them to cross the street independently. The presented approach provides the user with significant information such as detection of pedestrian crossing signal from any point of view, when the pedestrian crossing signal light is green, the detection of dynamic and fixed obstacles, predictions of the movement of fellow pedestrians and information on objects which may intersect his path. Our approach is based on capturing multiple frames using a depth camera which is attached to a user's headgear. Currently a testbed system is built on a helmet and is connected to a laptop in the user's backpack. In this paper, we discussed efficiency of using Speeded-Up Robust Features (SURF) algorithm for object recognition for purposes of blind people assistance. The system predicts the movement of objects of interest to provide the user with information on the safest path to navigate and information on the surrounding area. Evaluation of this approach on real sequence video frames provides 90% of human detection and more than 80% for recognition of other related objects.

Nonlinear surge motions of a ship in bi-chromatic following waves

NASA Astrophysics Data System (ADS)

Spyrou, Kostas J.; Themelis, Nikos; Kontolefas, Ioannis

2018-03-01

Unintended motions of a ship operating in steep and long following waves are investigated. A well-known such case is ;surf-riding; where a ship is carried forward by a single wave, an event invoking sometimes lateral instability and even capsize. The dynamics underlying this behavior has been clarified earlier for monochromatic waves. However, the unsteadiness of the phase space associated with ship behavior in a multichromatic sea, combined with the intrinsically strong system nonlinearity, pose new challenges. Here, current theory is extended to cover surging and surf-riding behavior in unidirectional bi-chromatic waves encountering a ship from the stern. Excitation is provided by two unidirectional harmonic wave components having their lengths comparable to the ship length and their frequencies in rational ratio. The techniques applied include (a) continuation analysis; (b) tracking of Lagrangian coherent structures in phase space, approximated through a finite-time Lyapunov exponents' calculation; and (c) large scale simulation. A profound feature of surf-riding in bi-chromatic waves is that it is turned oscillatory. Initially it appears as a frequency-locked motion, ruled by the harmonic wave component dominating the excitation. Transformations of oscillatory surf-riding are realized as the waves become steeper. In particular, heteroclinic tanglings are identified, governing abrupt transitions between qualitatively different motions. Chaotic transients, as well as long-term chaotic motions, exist near to these events. Some extraordinary patterns of ship motion are discovered. These include a counterintuitive low speed motion at very high wave excitation level; and a hybrid motion characterized by a wildly fluctuating velocity. Due to the quite generic nature of the core mathematical model of our investigation, the current results are believed to offer clues about the behavior of a class of nonlinear dynamical systems having in their modeling some analogy with a perturbed pendulum with bias.

Real-time pose invariant logo and pattern detection

NASA Astrophysics Data System (ADS)

Sidla, Oliver; Kottmann, Michal; Benesova, Wanda

2011-01-01

The detection of pose invariant planar patterns has many practical applications in computer vision and surveillance systems. The recognition of company logos is used in market studies to examine the visibility and frequency of logos in advertisement. Danger signs on vehicles could be detected to trigger warning systems in tunnels, or brand detection on transport vehicles can be used to count company-specific traffic. We present the results of a study on planar pattern detection which is based on keypoint detection and matching of distortion invariant 2d feature descriptors. Specifically we look at the keypoint detectors of type: i) Lowe's DoG approximation from the SURF algorithm, ii) the Harris Corner Detector, iii) the FAST Corner Detector and iv) Lepetit's keypoint detector. Our study then compares the feature descriptors SURF and compact signatures based on Random Ferns: we use 3 sets of sample images to detect and match 3 logos of different structure to find out which combinations of keypoint detector/feature descriptors work well. A real-world test tries to detect vehicles with a distinctive logo in an outdoor environment under realistic lighting and weather conditions: a camera was mounted on a suitable location for observing the entrance to a parking area so that incoming vehicles could be monitored. In this 2 hour long recording we can successfully detect a specific company logo without false positives.

The greenscape shapes surfing of resource waves in a large migratory herbivore.

PubMed

Aikens, Ellen O; Kauffman, Matthew J; Merkle, Jerod A; Dwinnell, Samantha P H; Fralick, Gary L; Monteith, Kevin L

2017-06-01

The Green Wave Hypothesis posits that herbivore migration manifests in response to waves of spring green-up (i.e. green-wave surfing). Nonetheless, empirical support for the Green Wave Hypothesis is mixed, and a framework for understanding variation in surfing is lacking. In a population of migratory mule deer (Odocoileus hemionus), 31% surfed plant phenology in spring as well as a theoretically perfect surfer, and 98% surfed better than random. Green-wave surfing varied among individuals and was unrelated to age or energetic state. Instead, the greenscape, which we define as the order, rate and duration of green-up along migratory routes, was the primary factor influencing surfing. Our results indicate that migratory routes are more than a link between seasonal ranges, and they provide an important, but often overlooked, foraging habitat. In addition, the spatiotemporal configuration of forage resources that propagate along migratory routes shape animal movement and presumably, energy gains during migration. © 2017 John Wiley & Sons Ltd/CNRS.

Physical linkages between an offshore canyon and surf zone morphologic change

NASA Astrophysics Data System (ADS)

Hansen, Jeff E.; Raubenheimer, Britt; Elgar, Steve; List, Jeffrey H.; Lippmann, Thomas C.

2017-04-01

The causes of surf zone morphologic changes observed along a sandy beach onshore of a submarine canyon were investigated using field observations and a numerical model (Delft3D/SWAN). Numerically simulated morphologic changes using four different sediment transport formulae reproduce the temporal and spatial patterns of net cross-shore integrated (between 0 and 6.5 m water depths) accretion and erosion observed in a ˜300 m alongshore region, a few hundred meters from the canyon head. The observations and simulations indicate that the accretion or erosion results from converging or diverging alongshore currents driven primarily by breaking waves and alongshore pressure gradients. The location of convergence or divergence depends on the direction of the offshore waves that refract over the canyon, suggesting that bathymetric features on the inner shelf can have first-order effects on short-term nearshore morphologic change.

Aetiology of injuries and the need for protective equipment for surfers in the UK.

PubMed

Woodacre, Timothy; Waydia, Shree Eesh; Wienand-Barnett, Sophie

2015-01-01

Surfing is a popular UK water-sport. Previous studies investigating surfing injuries have been principally based on trauma from large waves and reef breaks in the US and Australia. Subsequent conclusions and recommendations for the use of protective equipment in surfing may therefore not be relevant in the UK. This study examines the aetiology of surfing injuries in the UK. Data was collected in 2012 using a web-based survey distributed to UK surfing clubs. Surfers recorded time/experience as a surfer, number of episodes spent surfing per month, different breaks surfed and type, frequency and method of any injuries sustained whilst surfing in the UK, including treatment received. Completed surveys were obtained from 130 individuals, M:F division 85:45, median age 28 (range 17-65). 122 surfers reported a total of 335 injuries. Head injuries were the most common (24%) followed by ankle (19%), knee (13%), back (10%), hand/wrist (9%), elbow/shoulder (7%), trunk (7%), neck (4%), hip (4%) and genitalia (3%) injuries. Surfers collided most often with their own boards (31%). The other collisions were with rocks/coral (15%), the sea (11%), other surf boards (10%) the sea bed (7%), other water vessels (2%) and by paddle-boards (1%). Of 327 injuries, cuts/lacerations (31%) were the commonest type of injury, followed by bruises/peri-orbital ecchymoses (24%), joint/ligament sprains (15%), muscle or tendon tears/ruptures (9%), concussion (5%), fractures (3%) and teeth injuries (1%). The remaining 8 injuries were not categorized. 65% of the surfers never required professional medical treatment for their differing injuries. There were no skull fractures and no head injuries required neurosurgical intervention. Surfing injuries in the UK are common. They appear of a similar aetiology to those reported in the literature in countries with a high surfing population, but generally of a lower severity, with few requiring professional treatment, hospital admission or operative intervention. Concussion appears rare and in this study there were no head injuries that required neurosurgical intervention. Surfing helmets aim to prevent such serious head injuries; whilst they should be considered for injury prevention their routine use is unlikely to be warranted whilst surfing in the UK. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of structure of fatty acid collectors on the adsorption of fluorapatite (0 0 1) surface: A first-principles calculations

NASA Astrophysics Data System (ADS)

Xie, Jun; Li, Xianhai; Mao, Song; Li, Longjiang; Ke, Baolin; Zhang, Qin

2018-06-01

Effects of carbon chain length, carbon chain isomerism, Cdbnd C double bonds number on fatty acid adsorption on FAP (0 0 1) surface have been investigated based on DFT. The results revealed that fatty acid collector can form stable adsorption configuration at Ca1 (surf) site. Chemical adsorption was formed between O (mole) of fatty acid collector and the Ca1 (surf) of fluorapatite (0 0 1) surface; hydrogen bond adsorption was formed between the H (mole) of fatty acid and the O (surf) of-[PO4]- of FAP (0 0 1) surface. Fatty acid collectors and FAP (0 0 1) surface are bonding by means of the hybridization of O (mole) 2p and Ca (surf) 4d orbitals, H (mole) 1s and O (surf) 2p orbital. The analysis of adsorption energy, DOS, electron density, Mulliken charge population and Mulliken bond population revealed that with the carbon chain growing within certain limits, the absolute value of the adsorption energy and the overlapping area between the DOS curve of O (mole) and Ca (surf) was greater, while that of H (mole) 1s and O (surf) 2p basically remained unchanged. As Cdbnd C double bonds of fatty acids increased within certain limits, the adsorption energy and the overlapping area between the state density curve of O (mole) and Ca (surf), H (mole) and O (surf) basically remained unchanged. The substituent groups of fatty acid changed, the absolute value of the adsorption energy and the overlapping area between the state density curve had a major change. The influence of fatty acids adsorption on FAP (0 0 1) surface depends mainly on the interaction between O (mole) and Ca (surf).

Nearshore bars and the break-point hypothesis

USGS Publications Warehouse

Sallenger, A.H.; Howd, P.A.

1989-01-01

The set of hypotheses calling for bar formation at the break point was tested with field data. During two different experiments, waves were measured across the surf zone coincident with the development of a nearshore bar. We use a criterion, based on the wave height to depth ratio, to determine the offshore limit of the inner surf zone. During the first experiment, the bar became better developed and migrated offshore while remaining well within the inner surf zone. During the second experiment, the surf zone was narrower and we cannot rule out the possibility of break point processes contributing to bar development. We conclude that bars are not necessarily coupled with the break point and can become better developed and migrate offshore while being in the inner surf zone landward from initial wave breaking in the outer surf zone. ?? 1989.

Injuries resulting from car surfing--United States, 1990-2008.

PubMed

2008-10-17

"Car surfing" is a term introduced in the mid-1980s to describe a thrill-seeking activity that involves riding on the exterior of a moving motor vehicle while it is being driven by another person. Although reports of car-surfing injuries have been published in the United States, no study to date has analyzed these events from a national perspective. Because traditional public health datasets do not collect morbidity or mortality data on this practice, CDC searched U.S. newspaper reports to provide an initial characterization of car-surfing injuries on a national scale. That analysis identified 58 reports of car-surfing deaths and 41 reports of nonfatal injury from 1990 through August 2008. Most reports of car-surfing injuries came from newspapers in the Midwest and South (75%), and most of the injuries were among males (70%) and persons aged 15-19 years (69%). The first identified newspaper reports about car-surfing injuries were published in the early 1990s, and new reports have been published every year since then. Parents and teens should be aware of the potentially lethal consequences of car surfing, which can occur even at low vehicle speeds, sometimes resulting from unanticipated movements of the vehicle, such as swerving or braking.

Youth Homelessness and Vulnerability: How Does Couch Surfing Fit?

PubMed

Curry, Susanna R; Morton, Matthew; Matjasko, Jennifer L; Dworsky, Amy; Samuels, Gina M; Schlueter, David

2017-09-01

Youth homelessness is a problem characterized by high levels of vulnerability. The extent to which couch surfing - moving from one temporary housing arrangement to another - is part of youth homelessness is not well understood. Chapin Hall's Voices of Youth Count, a national research initiative, involves a multicomponent approach to studying youth homelessness. This study reports emerging findings regarding couch surfing and homelessness primarily from a national survey of 13,113 adults with youth ages 13-25 in their households or who are themselves ages 18-25. Findings suggest that couch surfing is relatively common, particularly among the older age group. Among households with 13- to 17-year-olds and 18- to 25-year-olds, 4.0% and 20.5%, respectively, reported that any of them had couch surfed in the last 12 months. There are notable social, economic, and educational differences, on average, between youth reporting homelessness and those reporting only couch surfing. However, most youth who report experiencing homelessness also report couch surfing, and these youth who experience both circumstances present high levels of socioeconomic vulnerability. Couch surfing encompasses a range of experiences, some of which likely include need for services. Interviews currently in the field, and expanded analysis of data, will contribute more nuanced policy insights. © Society for Community Research and Action 2017.

Multiple template-based image matching using alpha-rooted quaternion phase correlation

NASA Astrophysics Data System (ADS)

DelMarco, Stephen

2010-04-01

In computer vision applications, image matching performed on quality-degraded imagery is difficult due to image content distortion and noise effects. State-of-the art keypoint based matchers, such as SURF and SIFT, work very well on clean imagery. However, performance can degrade significantly in the presence of high noise and clutter levels. Noise and clutter cause the formation of false features which can degrade recognition performance. To address this problem, previously we developed an extension to the classical amplitude and phase correlation forms, which provides improved robustness and tolerance to image geometric misalignments and noise. This extension, called Alpha-Rooted Phase Correlation (ARPC), combines Fourier domain-based alpha-rooting enhancement with classical phase correlation. ARPC provides tunable parameters to control the alpha-rooting enhancement. These parameter values can be optimized to tradeoff between high narrow correlation peaks, and more robust wider, but smaller peaks. Previously, we applied ARPC in the radon transform domain for logo image recognition in the presence of rotational image misalignments. In this paper, we extend ARPC to incorporate quaternion Fourier transforms, thereby creating Alpha-Rooted Quaternion Phase Correlation (ARQPC). We apply ARQPC to the logo image recognition problem. We use ARQPC to perform multiple-reference logo template matching by representing multiple same-class reference templates as quaternion-valued images. We generate recognition performance results on publicly-available logo imagery, and compare recognition results to results generated from standard approaches. We show that small deviations in reference templates of sameclass logos can lead to improved recognition performance using the joint matching inherent in ARQPC.

Modeling and Simulation for a Surf Zone Robot

DTIC Science & Technology

2012-12-14

of-freedom surf zone robot is developed and tested with a physical test platform and with a simulated robot in Robot Operating System . Derived from...terrain. The application of the model to future platforms is analyzed and a broad examination of the current state of surf zone robotic systems is...public release; distribution is unlimited MODELING AND SIMULATION FOR A SURF ZONE ROBOT Eric Shuey Lieutenant, United States Navy B.S., Systems

Allele Surfing Promotes Microbial Adaptation from Standing Variation

PubMed Central

Gralka, Matti; Stiewe, Fabian; Farrell, Fred; Möbius, Wolfram; Waclaw, Bartek; Hallatschek, Oskar

2016-01-01

The coupling of ecology and evolution during range expansions enables mutations to establish at expanding range margins and reach high frequencies. This phenomenon, called allele surfing, is thought to have caused revolutions in the gene pool of many species, most evidently in microbial communities. It has remained unclear, however, under which conditions allele surfing promotes or hinders adaptation. Here, using microbial experiments and simulations, we show that, starting with standing adaptive variation, range expansions generate a larger increase in mean fitness than spatially uniform population expansions. The adaptation gain results from ‘soft’ selective sweeps emerging from surfing beneficial mutations. The rate of these surfing events is shown to sensitively depend on the strength of genetic drift, which varies among strains and environmental conditions. More generally, allele surfing promotes the rate of adaptation per biomass produced, which could help developing biofilms and other resource-limited populations to cope with environmental challenges. PMID:27307400

User's Manual for Space Debris Surfaces (SD_SURF)

NASA Technical Reports Server (NTRS)

Elfer, N. C.

1996-01-01

A unique collection of computer codes, Space Debris Surfaces (SD_SURF), have been developed to assist in the design and analysis of space debris protection systems. SD_SURF calculates and summarizes a vehicle's vulnerability to space debris as a function of impact velocity and obliquity. An SD_SURF analysis will show which velocities and obliquities are the most probable to cause a penetration. This determination can help the analyst select a shield design which is best suited to the predominant penetration mechanism. The analysis also indicates the most suitable parameters for development or verification testing. The SD_SURF programs offer the option of either FORTRAN programs and Microsoft EXCEL spreadsheets and macros. The FORTRAN programs work with BUMPERII version 1.2a or 1.3 (Cosmic released). The EXCEL spreadsheets and macros can be used independently or with selected output from the SD_SURF FORTRAN programs.

Surfing into spirituality and a new, aquatic nature religion.

PubMed

Taylor, Bron

2007-01-01

"Soul surfers" consider surfing to be a profoundly meaningful practice that brings physical, psychological, and spiritual benefits. They generally agree on where surfing initially developed, that it assumed a religious character, was suppressed for religious reasons, has been undergoing a revival, and enjoins reverence for and protection of nature. This subset of the global surfing community should be understood as a new religious movement-a globalizing, hybridized, and increasingly influential example of what I call aquatic nature religion. For these individuals, surfing is a religious form in which a specific sensual practice constitutes its sacred center, and the corresponding experiences are constructed in a way that leads to a belief in nature as powerful, transformative, healing, and sacred. I advance this argument by analyzing these experiences, as well as the myths, rites, symbols, terminology, technology, material culture, and ethical mores that are found within surfing subcultures.

Composition, shell strength, and metabolizable energy of Mulinia lateralis and Ischadium recurvum as food for wintering surf scoters (Melanitta perspicillata)

USGS Publications Warehouse

Berlin, Alicia; Perry, Matthew C.; Kohn, R.A.; Paynter, K.T.; Ottinger, Mary Ann

2015-01-01

Decline in surf scoter (Melanitta perspicillata) waterfowl populations wintering in the Chesapeake Bay has been associated with changes in the availability of benthic bivalves. The Bay has become more eutrophic, causing changes in the benthos available to surf scoters. The subsequent decline in oyster beds (Crassostrea virginica) has reduced the hard substrate needed by the hooked mussel (Ischadium recurvum), one of the primary prey items for surf scoters, causing the surf scoter to switch to a more opportune species, the dwarf surfclam (Mulinia lateralis). The composition (macronutrients, minerals, and amino acids), shell strength (N), and metabolizable energy (kJ) of these prey items were quantified to determine the relative foraging values for wintering scoters. Pooled samples of each prey item were analyzed to determine composition. Shell strength (N) was measured using a shell crack compression test. Total collection digestibility trials were conducted on eight captive surf scoters. For the prey size range commonly consumed by surf scoters (6-12 mm for M. lateralis and 18-24 mm for I. recurvum), I. recurvum contained higher ash, protein, lipid, and energy per individual organism than M. lateralis. I. recurvum required significantly greater force to crack the shell relative to M. lateralis. No difference in metabolized energy was observed for these prey items in wintering surf scoters, despite I. recurvum's higher ash content and harder shell than M. lateralis. Therefore, wintering surf scoters were able to obtain the same amount of energy from each prey item, implying that they can sustain themselves if forced to switch prey.

Composition, Shell Strength, and Metabolizable Energy of Mulinia lateralis and Ischadium recurvum as Food for Wintering Surf Scoters (Melanitta perspicillata)

PubMed Central

Wells-Berlin, Alicia M.; Perry, Matthew C.; Kohn, Richard A.; Paynter, Kennedy T.; Ottinger, Mary Ann

2015-01-01

Decline in surf scoter (Melanitta perspicillata) waterfowl populations wintering in the Chesapeake Bay has been associated with changes in the availability of benthic bivalves. The Bay has become more eutrophic, causing changes in the benthos available to surf scoters. The subsequent decline in oyster beds (Crassostrea virginica) has reduced the hard substrate needed by the hooked mussel (Ischadium recurvum), one of the primary prey items for surf scoters, causing the surf scoter to switch to a more opportune species, the dwarf surfclam (Mulinia lateralis). The composition (macronutrients, minerals, and amino acids), shell strength (N), and metabolizable energy (kJ) of these prey items were quantified to determine the relative foraging values for wintering scoters. Pooled samples of each prey item were analyzed to determine composition. Shell strength (N) was measured using a shell crack compression test. Total collection digestibility trials were conducted on eight captive surf scoters. For the prey size range commonly consumed by surf scoters (6–12 mm for M. lateralis and 18–24 mm for I. recurvum), I. recurvum contained higher ash, protein, lipid, and energy per individual organism than M. lateralis. I. recurvum required significantly greater force to crack the shell relative to M. lateralis. No difference in metabolized energy was observed for these prey items in wintering surf scoters, despite I. recurvum’s higher ash content and harder shell than M. lateralis. Therefore, wintering surf scoters were able to obtain the same amount of energy from each prey item, implying that they can sustain themselves if forced to switch prey. PMID:25978636

Forcing a three-dimensional, hydrostatic, primitive-equation model for application in the surf zone: 2. Application to DUCK94

NASA Astrophysics Data System (ADS)

Newberger, P. A.; Allen, J. S.

2007-08-01

A three-dimensional primitive-equation model for application to the nearshore surf zone has been developed. This model, an extension of the Princeton Ocean Model (POM), predicts the wave-averaged circulation forced by breaking waves. All of the features of the original POM are retained in the extended model so that applications can be made to regions where breaking waves, stratification, rotation, and wind stress make significant contributions to the flow behavior. In this study we examine the effects of breaking waves and wind stress. The nearshore POM circulation model is embedded within the NearCom community model and is coupled with a wave model. This combined modeling system is applied to the nearshore surf zone off Duck, North Carolina, during the DUCK94 field experiment of October 1994. Model results are compared to observations from this experiment, and the effects of parameter choices are examined. A process study examining the effects of tidal depth variation on depth-dependent wave-averaged currents is carried out. With identical offshore wave conditions and model parameters, the strength and spatial structure of the undertow and of the alongshore current vary systematically with water depth. Some three-dimensional solutions show the development of shear instabilities of the alongshore current. Inclusion of wave-current interactions makes an appreciable difference in the characteristics of the instability.

A Structured and Unstructured grid Relocatable ocean platform for Forecasting (SURF)

NASA Astrophysics Data System (ADS)

Trotta, Francesco; Fenu, Elisa; Pinardi, Nadia; Bruciaferri, Diego; Giacomelli, Luca; Federico, Ivan; Coppini, Giovanni

2016-11-01

We present a numerical platform named Structured and Unstructured grid Relocatable ocean platform for Forecasting (SURF). The platform is developed for short-time forecasts and is designed to be embedded in any region of the large-scale Mediterranean Forecasting System (MFS) via downscaling. We employ CTD data collected during a campaign around the Elba island to calibrate and validate SURF. The model requires an initial spin up period of a few days in order to adapt the initial interpolated fields and the subsequent solutions to the higher-resolution nested grids adopted by SURF. Through a comparison with the CTD data, we quantify the improvement obtained by SURF model compared to the coarse-resolution MFS model.

Risk behaviors and self-reported illnesses among Pacific Northwest surfers.

PubMed

Harding, Anna K; Stone, David L; Cardenas, Andres; Lesser, Virginia

2015-03-01

Although surfers have high incidental exposure to marine waters, no studies have investigated if surfer risk behaviors (such as surfing during advisories, near an outfall, during a rain event, or use of personal protective equipment) increase or decrease the risk of acquiring waterborne illnesses. We used a web-based survey to assess the association between risk-based behaviors and self-reported illnesses among Pacific Northwest surfers. Commonly reported illnesses include: ear infection or discharge (38%), sore throat or a cough (28%), diarrhea (16%), fever (10.5%), and vomiting (7%). Surfing often during rain events was associated with an increased likelihood of diarrhea (OR = 2.7; 95% CI: 1.4-5.47), sore throat (OR = 1.26; 95% CI: 1.01-2.05), and ear infection (OR = 1.39; 95% CI: 1.01-2.32). Surfing during a health advisory was associated with increased likelihood of diarrhea (OR = 1.94; 95% CI: 1.03-4.64) and sore throat (OR = 2.32; 95% CI: 1.23-4.40). Other behaviors associated with increased illnesses include body surfing, surfing near an outfall, frequency of surfing, and use of ear plugs. Approximately 40% of surfers were unaware if they had surfed during an active health advisory and 29% knowingly surfed during advisories, suggesting the need to engage this population about potential harm and behaviors that may increase health risk.

Leigh syndrome in Drosophila melanogaster: morphological and biochemical characterization of Surf1 post-transcriptional silencing.

PubMed

Da-Rè, Caterina; von Stockum, Sophia; Biscontin, Alberto; Millino, Caterina; Cisotto, Paola; Zordan, Mauro A; Zeviani, Massimo; Bernardi, Paolo; De Pittà, Cristiano; Costa, Rodolfo

2014-10-17

Leigh Syndrome (LS) is the most common early-onset, progressive mitochondrial encephalopathy usually leading to early death. The single most prevalent cause of LS is occurrence of mutations in the SURF1 gene, and LS(Surf1) patients show a ubiquitous and specific decrease in the activity of mitochondrial respiratory chain complex IV (cytochrome c oxidase, COX). SURF1 encodes an inner membrane mitochondrial protein involved in COX assembly. We established a Drosophila melanogaster model of LS based on the post-transcriptional silencing of CG9943, the Drosophila homolog of SURF1. Knockdown of Surf1 was induced ubiquitously in larvae and adults, which led to lethality; in the mesodermal derivatives, which led to pupal lethality; or in the central nervous system, which allowed survival. A biochemical characterization was carried out in knockdown individuals, which revealed that larvae unexpectedly displayed defects in all complexes of the mitochondrial respiratory chain and in the F-ATP synthase, while adults had a COX-selective impairment. Silencing of Surf1 expression in Drosophila S2R(+) cells led to selective loss of COX activity associated with decreased oxygen consumption and respiratory reserve. We conclude that Surf1 is essential for COX activity and mitochondrial function in D. melanogaster, thus providing a new tool that may help clarify the pathogenic mechanisms of LS. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Assessing Counselor Supervisee Contribution

ERIC Educational Resources Information Center

Stark, Marcella D.

2017-01-01

This article describes the revision of Vespia, Heckman-Stone, and Delworth's (2002) Supervision Utilization Rating Form (SURF) and validation of the resulting Adapted SURF. The Adapted SURF is designed to provide supervisors with a cleaner measure of supervisee behaviors that contribute to effective supervision.

Goofy vs. Regular: Laterality effects in surfing.

PubMed

Furley, Philip; Dörr, Jannik; Loffing, Florian

2018-02-01

The aim of the present study was to test if lateral preferences of surfers are associated with behaviour and performance depending on the direction of a breaking wave. We hypothesized that wave direction and surf stance interact in creating favourable or debilitative performance demands as surfers are either facing the wave (frontside) or the wave is breaking in the back of the surfers (backside). Study 1 was an online survey collecting self-report data of recreational surfers (n = 394). In Study 2, we analysed all wave scores (n = 2,552) and laterality of professional surfers during the season of 2014. Study 1 demonstrated that recreational surfers preferred surfing frontside and described themselves as more skilful when surfing frontside as this is facilitative for picking up visual information. Study 2 did not provide clear evidence that professional surfers on average scored higher during contests when surfing frontside, but when professional surfers had a choice of surfing frontside vs. backside, they were more likely to surf frontside. We discuss the diverging findings between Study 1 and Study 2 from the "circumvention-of-limits" argumentation within the expertise literature as professional surfers most likely have acquired skills allowing them to compensate for debilitative individual and environmental circumstances.

Simple estimate of entrainment rate of pollutants from a coastal discharge into the surf zone.

PubMed

Wong, Simon H C; Monismith, Stephen G; Boehm, Alexandria B

2013-10-15

Microbial pollutants from coastal discharges can increase illness risks for swimmers and cause beach advisories. There is presently no predictive model for estimating the entrainment of pollution from coastal discharges into the surf zone. We present a novel, quantitative framework for estimating surf zone entrainment of pollution at a wave-dominant open beach. Using physical arguments, we identify a dimensionless parameter equal to the quotient of the surf zone width l(sz) and the cross-flow length scale of the discharge la = M(j) (1/2)/U(sz), where M(j) is the discharge's momentum flux and U(sz) is a representative alongshore velocity in the surf zone. We conducted numerical modeling of a nonbuoyant discharge at an alongshore uniform beach with constant slope using a wave-resolving hydrodynamic model. Using results from 144 numerical experiments we develop an empirical relationship between the surf zone entrainment rate α and l(sz)/(la). The empirical relationship can reasonably explain seven measurements of surf zone entrainment at three diverse coastal discharges. This predictive relationship can be a useful tool in coastal water quality management and can be used to develop predictive beach water quality models.

Summary of Research 1998, Interdisciplinary Academic Groups

DTIC Science & Technology

1999-08-01

Seismic Sonar, Biosonar SEISMO ACOUSTIC DETECTION OF MINES BURIED IN THE SURF ZONE Thomas Muir, Chair of Mine Warfare Undersea Warfare Academic Group...Mine Warfare KEYWORDS: Mining, Mine Countermeasures, Surf Zone, Seismic Sonar, Biosonar PHYSICS OF SEISMIC INTERFACE WAVES IN THE SURF ZONE

Mining and Querying Multimedia Data

DTIC Science & Technology

2011-09-29

able to capture more subtle spatial variations such as repetitiveness. Local feature descriptors such as SIFT [74] and SURF [12] have also been widely...empirically set to s = 90%, r = 50%, K = 20, where small variations lead to little perturbation of the output. The pseudo-code of the algorithm is...by constructing a three-layer graph based on clustering outputs, and executing a slight variation of random walk with restart algorithm. It provided

Using MountainsMap (Digital Surf) surface analysis software as an analysis tool for x-ray mirror optical metrology data

NASA Astrophysics Data System (ADS)

Duffy, Alan; Yates, Brian; Takacs, Peter

2012-09-01

The Optical Metrology Facility at the Canadian Light Source (CLS) has recently purchased MountainsMap surface analysis software from Digital Surf and we report here our experiences with this package and its usefulness as a tool for examining metrology data of synchrotron x-ray mirrors. The package has a number of operators that are useful for determining surface roughness and slope error including compliance with ISO standards (viz. ISO 4287 and ISO 25178). The software is extensible with MATLAB scripts either by loading an m-file or by a user written script. This makes it possible to apply a custom operator to measurement data sets. Using this feature we have applied the simple six-line MATLAB code for the direct least square fitting of ellipses developed by Fitzgibbon et. al. to investigate the residual slope error of elliptical mirrors upon the removal of the best-fit-ellipse. The software includes support for many instruments (e.g. Zygo, MicroMap, etc...) and can import ASCII data (e.g. LTP data). The stitching module allows the user to assemble overlapping images and we report on our experiences with this feature applied to MicroMap surface roughness data. The power spectral density function was determined for the stitched and unstitched data and compared.

50 CFR 648.1 - Purpose and scope.

Code of Federal Regulations, 2011 CFR

2011-10-01

... fishery (Scallop FMP); the Atlantic surf clam and ocean quahog fisheries (Atlantic Surf Clam and Ocean... clam” and “Surf Clam” and adding “surfclam” and “Surfclam” in their place, respectively, effective... fishery management plans (FMPs) for the Atlantic mackerel, squid, and butterfish fisheries (Atlantic...

Factors affecting surf zone phytoplankton production in Southeastern North Carolina, USA

NASA Astrophysics Data System (ADS)

Cahoon, Lawrence B.; Bugica, Kalman; Wooster, Michael K.; Dickens, Amanda Kahn

2017-09-01

The biomass and productivity of primary producers in the surf zone of the ocean beach at Wrightsville Beach, North Carolina, USA, were measured during all seasons, along with environmental parameters and nutrient levels. Variation in biomass (chlorophyll a) was associated with temperature. Primary production (PP), measured by in situ 14-C incubations, was a function of chlorophyll a, tide height at the start of incubations, and rainfall in the preceding 24-hr period. Biomass-normalized production (PB) was also a function of tide height and rainfall in the preceding 24-hr period. We interpreted these results as evidence of surf production 1) as combined contributions of phytoplankton and suspended benthic microalgae, which may confound application of simple P-E models to surf zone production, and 2) being regulated by nutrient source/supply fluctuations independently from other factors. Surf zone biomass and production levels are intermediate between relatively high estuarine values and much lower coastal ocean values. Surf zone production may represent an important trophic connection between these two important ecosystems.

Reductions in Sprint Paddling Ability and Countermovement Jump Performance After Surfing Training.

PubMed

Secomb, Josh L; Sheppard, Jeremy M; Dascombe, Ben J

2015-07-01

The present study aimed to determine whether any meaningful change in a surfer's sprint paddling ability and countermovement jump (CMJ) performance developed after a 2-hour surfing training session and also whether any physical demands of the surfing session were related to the resultant changes in the capacities. Fifteen competitive male surfing athletes (age, 22.1 ± 3.9 years; height, 175.4 ± 6.4 cm; body mass, 72.5 ± 7.7 kg) performed a 2-hour surfing training session, with 15-m sprint paddle and CMJ trials performed both before and after the surfing session. Pre- to posttesting measures were analyzed using magnitude-based inferences. Likely declines were observed in the velocity achieved at the 5-, 10-, and 15-m splits of the 15-m sprint paddle, as well as peak velocity. Similarly, likely declines were calculated for CMJ peak force, relative peak force, and jump height. Furthermore, large correlations were calculated between presurfing session peak velocity and the change in 5, 10, 15 m, and peak velocity of the 15-m sprint paddle and total distance covered, wave riding bouts, and success rate. Surfing athletes and coaches may need to consider implementing shorter duration training sessions to reduce the decline in sprint paddling ability and CMJ performance. Furthermore, surfing athletes should possess highly developed sprint paddling ability because this may allow them to undertake a greater workload and catch more waves, which will increase the opportunity for technical refinement of maneuvers and skill acquisition.

An analytical model for non-conservative pollutants mixing in the surf zone.

PubMed

Ki, Seo Jin; Hwang, Jin Hwan; Kang, Joo-Hyon; Kim, Joon Ha

2009-01-01

Accurate simulation of the surf zone is a prerequisite to improve beach management as well as to understand the fundamentals of fate and transport of contaminants. In the present study, a diagnostic model modified from a classic solute model is provided to illuminate non-conservative pollutants behavior in the surf zone. To readily understand controlling processes in the surf zone, a new dimensionless quantity is employed with index of kappa number (K, a ratio of inactivation rate to transport rate of microbial pollutant in the surf zone), which was then evaluated under different environmental frames during a week simulation period. The sensitivity analysis showed that hydrodynamics and concentration gradients in the surf zone mostly depend on n (number of rip currents), indicating that n should be carefully adjusted in the model. The simulation results reveal, furthermore, that large deviation typically occurs in the daytime, signifying inactivation of fecal indicator bacteria is the main process to control surf zone water quality during the day. Overall, the analytical model shows a good agreement between predicted and synthetic data (R(2) = 0.51 and 0.67 for FC and ENT, respectively) for the simulated period, amplifying its potential use in the surf zone modelling. It is recommended that when the dimensionless index is much larger than 0.5, the present modified model can predict better than the conventional model, but if index is smaller than 0.5, the conventional model is more efficient with respect to time and cost.

Animation control of surface motion capture.

PubMed

Tejera, Margara; Casas, Dan; Hilton, Adrian

2013-12-01

Surface motion capture (SurfCap) of actor performance from multiple view video provides reconstruction of the natural nonrigid deformation of skin and clothing. This paper introduces techniques for interactive animation control of SurfCap sequences which allow the flexibility in editing and interactive manipulation associated with existing tools for animation from skeletal motion capture (MoCap). Laplacian mesh editing is extended using a basis model learned from SurfCap sequences to constrain the surface shape to reproduce natural deformation. Three novel approaches for animation control of SurfCap sequences, which exploit the constrained Laplacian mesh editing, are introduced: 1) space–time editing for interactive sequence manipulation; 2) skeleton-driven animation to achieve natural nonrigid surface deformation; and 3) hybrid combination of skeletal MoCap driven and SurfCap sequence to extend the range of movement. These approaches are combined with high-level parametric control of SurfCap sequences in a hybrid surface and skeleton-driven animation control framework to achieve natural surface deformation with an extended range of movement by exploiting existing MoCap archives. Evaluation of each approach and the integrated animation framework are presented on real SurfCap sequences for actors performing multiple motions with a variety of clothing styles. Results demonstrate that these techniques enable flexible control for interactive animation with the natural nonrigid surface dynamics of the captured performance and provide a powerful tool to extend current SurfCap databases by incorporating new motions from MoCap sequences.

Influence of the Surf Zone on the Marine Aerosol Concentration in a Coastal Area

NASA Astrophysics Data System (ADS)

Tedeschi, Gilles; van Eijk, Alexander M. J.; Piazzola, Jacques; Kusmierczyk-Michulec, Jolanta T.

2017-01-01

Sea-salt aerosol concentrations in the coastal zone are assessed with the numerical aerosol-transport model MACMod that applies separate aerosol source functions for open ocean and the surf zone near the sea-land transition. Numerical simulations of the aerosol concentration as a function of offshore distance from the surf zone compare favourably with experimental data obtained during a surf-zone aerosol experiment in Duck, North Carolina in autumn 2007. Based on numerical simulations, the effect of variations in aerosol production (source strength) and transport conditions (wind speed, air-sea temperature difference), we show that the surf-zone aerosols are replaced by aerosols generated over the open ocean as the airmass advects out to sea. The contribution from the surf-generated aerosol is significant during high wind speeds and high wave events, and is significant up to 30 km away from the production zone. At low wind speeds, the oceanic component dominates, except within 1-5 km of the surf zone. Similar results are obtained for onshore flow, where no further sea-salt aerosol production occurs as the airmass advects out over land. The oceanic aerosols that are well-mixed throughout the boundary layer are then more efficiently transported inland than are the surf-generated aerosols, which are confined to the first few tens of metres above the surface, and are therefore also more susceptible to the type of surface (trees or grass) that determines the deposition velocity.

Global assessment of surfing conditions: seasonal, interannual and long-term variability

NASA Astrophysics Data System (ADS)

Espejo, A.; Losada, I.; Mendez, F.

2012-12-01

International surfing destinations owe a great debt to specific combinations of wind-wave, thermal conditions and local bathymetry. As surf quality depends on a vast number of geophysical variables, a multivariable standardized index on the basis of expert judgment is proposed to analyze surf resource in a worldwide domain. Data needed is obtained by combining several datasets (reanalyses): 60-year satellite-calibrated spectral wave hindcast (GOW, WaveWatchIII), wind fields from NCEP/NCAR, global sea surface temperature from ERSST.v3b, and global tides from TPXO7.1. A summary of the global surf resource is presented, which highlights the high degree of variability in surfable events. According to general atmospheric circulation, results show that west facing low to middle latitude coasts are more suitable for surfing, especially those in Southern Hemisphere. Month to month analysis reveals strong seasonal changes in the occurrence of surfable events, enhancing those in North Atlantic or North Pacific. Interannual variability is investigated by comparing occurrence values with global and regional climate patterns showing a great influence at both, global and regional scales. Analysis of long term trends shows an increase in the probability of surfable events over the west facing coasts on the planet (i.e. + 30 hours/year in California). The resulting maps provide useful information for surfers and surf related stakeholders, coastal planning, education, and basic research.; Figure 1. Global distribution of medium quality (a) and high quality surf conditions probability (b).

50 CFR 648.6 - Dealer/processor permits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... deep-sea red crab, spiny dogfish, summer flounder, Atlantic surf clam, ocean quahog, Atlantic mackerel, squid, butterfish, scup, bluefish, tilefish, and black sea bass; Atlantic surf clam and ocean quahog... business if applying for a surf clam and ocean quahog permit), mailing address(es) and telephone number(s...

Parents' Perspectives on Surf Therapy for Children with Disabilities

ERIC Educational Resources Information Center

Moore, Adam M.; Clapham, Emily D.; Deeney, Theresa A.

2018-01-01

This qualitative study was designed to understand parents' perceptions of their children's participation in an inclusive surf therapy programme in the United States. Ten parents and one caregiver were interviewed about theirs and their children's experience in the surf programme. Parent discussions centred on the child, parent/caregiver,…

Medical Aspects of Surfing.

ERIC Educational Resources Information Center

Renneker, Mark

1987-01-01

The medical aspects of surfing include ear and eye injuries and sprains and strains of the lower back and neck, as well as skin cancer from exposure to the sun. Treatment, rehabilitation, and prevention of these problems are discussed. Surfing is recommended as part of an exercise program for reasonably healthy people. (Author/MT)

Getting started with package sampSurf

Treesearch

Jeffrey H. Gove

2014-01-01

The sampSurf package is designed to facilitate the comparison of new and existing areal sampling methods through simulation. The package is thoroughly documented in several vignettes as mentioned below. This document is meant to point you in the right direction in finding the needed information to get started using sampSurf.

Liquid Ice Surfers--The Construction of Surfer Identities in Norway

ERIC Educational Resources Information Center

Langseth, Tommy

2012-01-01

Surfing is getting increasingly popular in Norway as well as other countries that have a coastline with rideable waves. As surfing gains in popularity, however, the boundaries of the surfing subculture become increasingly guarded. Through ethnography and qualitative interviews, this study examines identity construction on an individual and group…

50 CFR 648.72 - Minimum surf clam size.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.72 Minimum surf clam size. Link to an amendment... quahog specifications. (a) Establishing catch quotas. The amount of surfclams or ocean quahogs that may... paragraph (b) of this section. The amount of surfclams available for harvest annually must be specified...

Women in wetsuits: revolting bodies in lesbian surf culture.

PubMed

Roy, Georgina

2013-01-01

The article unpicks the notion of lesbian bodies as revolting through an analysis of how "women in wetsuits" are experienced as both disgusting and desirable by lesbian surfers. Based on ethnographic research carried out within British surf culture, I consider how lesbian surfing bodies come to be experienced and embodied as disgusting, desirable, and revolting. Informed by interview data and personal reflections I suggest that the affective power of lesbian desire might offer ways in which to disrupt the cultural processes that shame bodies and in doing so enable surfing bodies to revolt.

Survival of mutations arising during invasions

PubMed Central

Miller, Judith R

2010-01-01

When a neutral mutation arises in an invading population, it quickly either dies out or ‘surfs’, i.e. it comes to occupy almost all the habitat available at its time of origin. Beneficial mutations can also surf, as can deleterious mutations over finite time spans. We develop descriptive statistical models that quantify the relationship between the probability that a mutation will surf and demographic parameters for a cellular automaton model of surfing. We also provide a simple analytic model that performs well at predicting the probability of surfing for neutral and beneficial mutations in one dimension. The results suggest that factors – possibly including even abiotic factors – that promote invasion success may also increase the probability of surfing and associated adaptive genetic change, conditioned on such success. PMID:25567912

New splicing-site mutations in the SURF1 gene in Leigh syndrome patients.

PubMed

Pequignot, M O; Desguerre, I; Dey, R; Tartari, M; Zeviani, M; Agostino, A; Benelli, C; Fouque, F; Prip-Buus, C; Marchant, D; Abitbol, M; Marsac, C

2001-05-04

The gene SURF1 encodes a factor involved in the biogenesis of cytochrome c oxidase, the last complex in the respiratory chain. Mutations of the SURF1 gene result in Leigh syndrome and severe cytochrome c oxidase deficiency. Analysis of seven unrelated patients with cytochrome c oxidase deficiency and typical Leigh syndrome revealed different SURF1 mutations in four of them. Only these four cases had associated demyelinating neuropathy. Three mutations were novel splicing-site mutations that lead to the excision of exon 6. Two different novel heterozygous mutations were found at the same guanine residue at the donor splice site of intron 6; one was a deletion, whereas the other was a transition [588+1G>A]. The third novel splicing-site mutation was a homozygous [516-2_516-1delAG] in intron 5. One patient only had a homozygous polymorphism in the middle of the intron 8 [835+25C>T]. Western blot analysis showed that Surf1 protein was absent in all four patients harboring mutations. Our studies confirm that the SURF1 gene is an important nuclear gene involved in the cytochrome c oxidase deficiency. We also show that Surf1 protein is not implicated in the assembly of other respiratory chain complexes or the pyruvate dehydrogenase complex.

Efficient hybrid monocular-stereo approach to on-board video-based traffic sign detection and tracking

NASA Astrophysics Data System (ADS)

Marinas, Javier; Salgado, Luis; Arróspide, Jon; Camplani, Massimo

2012-01-01

In this paper we propose an innovative method for the automatic detection and tracking of road traffic signs using an onboard stereo camera. It involves a combination of monocular and stereo analysis strategies to increase the reliability of the detections such that it can boost the performance of any traffic sign recognition scheme. Firstly, an adaptive color and appearance based detection is applied at single camera level to generate a set of traffic sign hypotheses. In turn, stereo information allows for sparse 3D reconstruction of potential traffic signs through a SURF-based matching strategy. Namely, the plane that best fits the cloud of 3D points traced back from feature matches is estimated using a RANSAC based approach to improve robustness to outliers. Temporal consistency of the 3D information is ensured through a Kalman-based tracking stage. This also allows for the generation of a predicted 3D traffic sign model, which is in turn used to enhance the previously mentioned color-based detector through a feedback loop, thus improving detection accuracy. The proposed solution has been tested with real sequences under several illumination conditions and in both urban areas and highways, achieving very high detection rates in challenging environments, including rapid motion and significant perspective distortion.

Surfer's ear: external auditory exostoses are more prevalent in cold water surfers.

PubMed

Kroon, David F; Lawson, M Louise; Derkay, Craig S; Hoffmann, Karen; McCook, Joe

2002-05-01

The study goal was to demonstrate the prevalence and severity of external auditory exostoses (EAEs) in a population of surfers and to examine the relationship between these lesions and the length of time surfed as well as water temperature in which the swimmers surfed. It was hypothesized that subjects who predominantly surfed in colder waters had more frequent and more severe exostoses. Two hundred two avid surfers (91% male and 9% female, median age 17 years) were included in the study. EAEs were graded based on the extent of external auditory canal patency; grades of normal (100% patency), mild (66% to 99% patency), and moderate-severe (<66% patency) were assigned. Otoscopic findings were correlated with data collected via questionnaires that detailed surfing habits. There was a 38% overall prevalence of EAEs, with 69% of lesions graded as mild and 31% graded as moderate-severe. Professional surfers (odds ratio 3.8) and those subjects who surfed predominantly in colder waters (odds ratio 5.8) were found to be at a significantly increased risk for the development of EAEs. The number of years surfed was also found to be significant, increasing one's risk for developing an exostosis by 12% per year and for developing more severe lesions by 10% per year. Individuals who had moderate-severe EAEs were significantly more likely to be willing to surf in colder waters than were those who had mild EAEs (odds ratio 4.3). EAEs are more prevalent in cold water surfers, and additional years surfing increase one's risk not only for developing an EAE but also for developing more severe lesions.

The Rate of Beneficial Mutations Surfing on the Wave of a Range Expansion

PubMed Central

Lehe, Rémi; Hallatschek, Oskar; Peliti, Luca

2012-01-01

Many theoretical and experimental studies suggest that range expansions can have severe consequences for the gene pool of the expanding population. Due to strongly enhanced genetic drift at the advancing frontier, neutral and weakly deleterious mutations can reach large frequencies in the newly colonized regions, as if they were surfing the front of the range expansion. These findings raise the question of how frequently beneficial mutations successfully surf at shifting range margins, thereby promoting adaptation towards a range-expansion phenotype. Here, we use individual-based simulations to study the surfing statistics of recurrent beneficial mutations on wave-like range expansions in linear habitats. We show that the rate of surfing depends on two strongly antagonistic factors, the probability of surfing given the spatial location of a novel mutation and the rate of occurrence of mutations at that location. The surfing probability strongly increases towards the tip of the wave. Novel mutations are unlikely to surf unless they enjoy a spatial head start compared to the bulk of the population. The needed head start is shown to be proportional to the inverse fitness of the mutant type, and only weakly dependent on the carrying capacity. The precise location dependence of surfing probabilities is derived from the non-extinction probability of a branching process within a moving field of growth rates. The second factor is the mutation occurrence which strongly decreases towards the tip of the wave. Thus, most successful mutations arise at an intermediate position in the front of the wave. We present an analytic theory for the tradeoff between these factors that allows to predict how frequently substitutions by beneficial mutations occur at invasion fronts. We find that small amounts of genetic drift increase the fixation rate of beneficial mutations at the advancing front, and thus could be important for adaptation during species invasions. PMID:22479175

Clinical and laboratory survey of 65 Chinese patients with Leigh syndrome.

PubMed

Yang, Yan-ling; Sun, Fang; Zhang, Yao; Qian, Ning; Yuan, Yun; Wang, Zhao-xia; Qi, Yu; Xiao, Jiang-xi; Wang, Xiao-ying; Qi, Zhao-yue; Zhang, Yue-hua; Jiang, Yu-wu; Bao, Xin-hua; Qin, Jiong; Wu, Xi-ru

2006-03-05

Leigh syndrome is an inherited neurodegenerative disease that emerges in infancy and childhood and presents with a clinically heterogeneous variety of neuromuscular and non-neuromuscular disorders. It can result from the inheritance of mutations in either nuclear or mitochondrial DNA. In the current study, we performed a retrospective study in 65 patients in order to investigate the clinical and genetic characteristics of Leigh syndrome in Chinese patients. Sixty-five unrelated cases (35 men and 30 women) who were hospitalized in the past 12 years were reviewed. Diagnosis was based on both the clinical presentation and the characteristic neuropathologic findings of bilateral symmetric necrotizing lesions in the basal ganglia and brain stem as detected using cranial computed tomography (CT) scan or magnetic resonance imaging (MRI). The differential diagnosis of organic acidurias and fatty acid beta-oxidation defects were performed. Specific point mutations and deletions in mitochondrial DNA (T8993G, T8993C, T9176C, A8344G, A3243G) were screened by PCR-restriction analysis and Southern blot. The SURF1 gene was sequenced. Skeletal muscle biopsies were performed in 17 (26.2%) of the patients. The diagnosis was confirmed by autopsy in 6 (9.2%) patients. The patients had various forms of metabolic encephalomyopathy. Fifty-nine (90.8%) of the patients had the typical neuroradiological features of Leigh syndrome, including symmetrical necrotizing lesions scattered within the basal ganglia, thalamus and brain stem. Twenty (30.8%) patients were confirmed by genetic, biochemical analysis and autopsy. Specific point mutations in mitochondrial DNA were found in 5 cases (7.7%). Of these, the A8344G mutation was detected in 2 patients. The T8993G, T8993C, and A3243G point mutations were identified in 3 other patients, respectively. SURF1 mutations associated with cytochrome c oxidase deficiency were identified in 8 (12.3%) families by DNA sequencing. A G604C mutation was identified in 6 (9.2%) patients. The genotypes of 52 patients remained unknown. Leigh syndrome presents as a diverse array of clinical features and can result from specific mutations in nuclear or mitochondrial DNA. In this study, SURF1 mutations associated with cytochrome c oxidase deficiency were identified in 8 (12.3%) out of 65 patients with Leigh syndrome. It indicates that SURF1 mutations might be a common cause of Leigh syndrome in China. The etiology of Leigh syndrome in Chinese patients represents a persistent challenge to clinicians.

Genome Surfing As Driver of Microbial Genomic Diversity.

PubMed

Choudoir, Mallory J; Panke-Buisse, Kevin; Andam, Cheryl P; Buckley, Daniel H

2017-08-01

Historical changes in population size, such as those caused by demographic range expansions, can produce nonadaptive changes in genomic diversity through mechanisms such as gene surfing. We propose that demographic range expansion of a microbial population capable of horizontal gene exchange can result in genome surfing, a mechanism that can cause widespread increase in the pan-genome frequency of genes acquired by horizontal gene exchange. We explain that patterns of genetic diversity within Streptomyces are consistent with genome surfing, and we describe several predictions for testing this hypothesis both in Streptomyces and in other microorganisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

MindSurf: a pilot study to assess the usability and acceptability of a smartphone app designed to promote contentment, wellbeing, and goal achievement.

PubMed

Carey, Timothy A; Haviland, Jennifer; Tai, Sara J; Vanags, Thea; Mansell, Warren

2016-12-12

The Method of Levels (MOL) is a transdiagnostic cognitive therapy that promotes contentment, wellbeing, and goal achievement through the resolution of internal conflicts underlying psychological distress. MOL, based on Perceptual Control Theory (PCT), was developed in routine clinical practice and has been used effectively across different health services by different practitioners. Access to MOL-style questions through a smartphone app could, potentially, help both the general public maintain robust mental health, and also be a useful adjunct to therapy for clinical populations. The app is called MindSurf because of its focus on helping people explore their thinking. Prior to developing the app and using it with different populations it was necessary to determine whether such an idea would be usable for and acceptable to potential app users. Therefore, a pilot study was conducted with a non-clinical sample to assess the usability and acceptability of the app including monitoring whether the questions delivered in this way were associated with any adverse events. A pilot study using quantitative as well as qualitative methods and incorporating a repeated measures, A-B design was conducted. The 23 participants were healthy adult volunteers who were all either undergraduate students, postgraduate students, or staff of the University of Manchester. They received MOL-style questions on their mobile phones over a 1-week period. Qualitative results were encouraging and indicated that the format and style of questioning were acceptable to participants and did not lead to increased worry or concern. A one-way, repeated measures ANOVA indicated that there was a nonsignificant decrease in scores on the 21-item Depression, Anxiety, and Stress Scale (DASS21) over a 2 week period. The results of the pilot study justified development of MindSurf and further testing once it is available for use. A power analysis indicated that the pilot study was underpowered to detect significant effects but provided important information regarding the appropriate sample size for future research. The pilot study also indicated that future research should investigate the effects of receiving more than three questions per day. Results of the pilot study indicate that MindSurf will be a usable and acceptable app. Its benefits should be further explored through longer studies with larger sample of both the general population as well as clinical populations.

Surfing depth on a behaviour change website: predictors and effects on behaviour.

PubMed

Jacobs, Nele; De Bourdeaudhuij, Ilse; Claes, Neree

2010-03-01

The primary objectives of the present study were to gain insight into website use and to predict the surfing depth on a behaviour change website and its effect on behaviour. Two hundred eight highly educated adults from the intervention condition of a randomised trial received access to a medical intervention, individual coaching (by e-mail, post, telephone or face-to-face) and a behaviour change website. Website use (e.g. surfing depth, page view duration) was registered. Online questionnaires for physical activity and fat intake were filled out at baseline and after 6 months. Hierarchical linear regression was used to predict surfing depth and its effect on behaviour. Seventy-five per cent of the participants visited the website. Fifty-one and fifty-six per cent consulted the physical activity and fat intake feedback, respectively. The median surfing depth was 2. The total duration of interventions by e-mail predicted deeper surfing (beta=0.36; p<0.001). Surfing depth did not predict changes in fat intake (beta=-0.07; p=0.45) or physical activity (beta=-0.03; p=0.72). Consulting the physical activity feedback led to more physical activity (beta=0.23; p=0.01). The findings from the present study can be used to guide future website development and improve the information architecture of behaviour change websites.

Characterization of breeding habitats for black and surf scoters in the eastern boreal forest and subarctic regions of Canada

USGS Publications Warehouse

Perry, M.C.; Kidwell, D.M.; Wells, A.M.; Lohnes, E.J.R.; Osenton, P.C.; Altmann, S.H.; Hanson, Alan; Kerekes, Joseph; Paquet, Julie

2006-01-01

We analyzed characteristics of wetland habitats used by breeding black scoters (Melanitta nigra) and surf scoters (M. perspicillata) in the eastern boreal forest and subarctic regions of Canada based on satellite telemetry data collected in the spring and summer. During 2002 and 2004, nine black scoters (four males, five females) were tracked to breeding areas in Quebec, Manitoba, and Northwest Territories. In addition, in 2001?04, seven surf scoters (three males, four females) were tracked to breeding areas in Labrador, Quebec, Northwest Territories, and Nunavut. Based on satellite telemetry data, locations of black and surf scoters in breeding areas were not significantly different in regard to latitude and longitude. Presumed breeding areas were manually plotted on topographic maps and percent cover type and water were estimated. Breeding habitat of black scoters was significantly different than that for surf scoters, with black scoters mainly using open (tundra) areas (44%) and surf scoters using mainly forest areas (66%). Surf scoters presumed breeding areas were at significantly higher elevations than areas used by black scoters. Some breeding areas were associated with islands, but the role of islands for breeding areas is equivocal. These results aid in the identification of potentially critical breeding areas and provide a baseline classification of breeding habitats used by these two species.

Quality analysis, miceller behavior, and environmental impact of some laundry detergents available in Bangladesh.

PubMed

Nur-E-Alam, M; Islam, M Monirul; Islam, M Nazrul; Rima, Farhana Rahman; Islam, M Nurul

2016-03-01

The cleansing efficiencies of laundry detergents depend on composition and variation of ingredients such as surfactants, phosphate, and co-builders. Among these ingredients, surfactants and phosphate are considered as hazardous materials. Knowledge on compositions and micellar behavior is very useful for understanding their cleansing efficiencies and environmental impact. With this view, composition, critical micelle concentration, and dissolved oxygen level in aqueous solution of some laundry detergents available in Bangladesh such as keya, Wheel Power White, Tibet, Surf Excel, and Chaka were determined. Surfactant and phosphate were found to be maximum in Surf Excel and Wheel Power White, respectively, while both of the ingredients were found to be minimum in Tibet. The critical micelle concentration decreased with increasing surfactant content. The amount of laundry detergents required for efficient cleansing was found to be minimum for Surf Excel and maximum for Chaka; however, cleansing cost was the highest for Surf Excel and the lowest for Tibet. The maximum amount of surfactants and phosphate was discharged by Surf Excel and Wheel Power White, respectively, while discharges of both of the ingredients were minimum for Tibet. The maximum decrease of dissolved oxygen level was caused by Surf Excel and the minimum by Tibet. Therefore, it can be concluded that Tibet is cost-effective and environment friendly, whereas Surf Excel and Wheel Power White are expensive and pose a threat to water environment.

Surfing on the Spectrum

ERIC Educational Resources Information Center

Apel, Laura

2007-01-01

Israel Paskowitz loves surfing. As a former competitive surfer, he has spent much of his life in the ocean and absorbed in a community of athletes that share a special connection with the water. Surfing is often thought of as a spiritual hobby that brings peace and relaxation to those who experience it. However, it was not until Israel's son,…

Complex IV Deficient Surf1−/− Mice Initiate Mitochondrial Stress Responses

PubMed Central

Pulliam, Daniel A.; Deepa, Sathyaseelan S.; Liu, Yuhong; Hill, Shauna; Lin, Ai-Ling; Bhattacharya, Arunabh; Shi, Yun; Sloane, Lauren; Viscomi, Carlo; Zeviani, Massimo; Van Remmen, Holly

2014-01-01

Summary Mutations in SURF1 cytochrome c oxidase (COX) assembly protein are associated with Leigh’s syndrome, a human mitochondrial disorder that manifests as severe mitochondrial phenotypes and early lethality. In contrast, mice lacking the Surf1 protein (Surf1−/−) are viable and were previously shown to have enhanced longevity and a greater than 50% reduction in COX activity. We measured mitochondrial function in heart and skeletal muscle, and despite the significant reduction in COX activity, we found little or no difference in reactive oxygen species (ROS) generation, membrane potential, ATP production or respiration in isolated mitochondria from Surf1−/− mice compared to wild-type. However, blood lactate levels are elevated and Surf1−/− mice have reduced running endurance, suggesting compromised mitochondrial energy metabolism in vivo. Decreased COX activity in Surf1−/− mice is associated with increased markers of mitochondrial biogenesis (PGC-1α and VDAC) in both heart and skeletal muscle. While mitochondrial biogenesis is a common response in the two tissues, skeletal muscle have an up-regulation of the mitochondrial unfolded protein response (UPRMT) and heart exhibits induction of the Nrf2 antioxidant response pathway. These data are the first to report induction of the UPRMT in a mammalian model of diminished COX activity. In addition our results suggest that impaired mitochondrial function can lead to induction of mitochondrial stress pathways to confer protective effects on cellular homeostasis. Loss of complex IV assembly factor Surf1 in mice results in compensatory responses including mitochondrial biogenesis, the nrf2 pathway and the mitochondrial unfolded protein response. This compensatory response may contribute to the lack of deleterious phenotypes under basal conditions. PMID:24911525

Green‐wave surfing increases fat gain in a migratory ungulate

USGS Publications Warehouse

Middleton, Arthur D.; Merkle, Jerod A.; McWhirter, Douglas E.; Cook, John G.; Cook, Rachel C.; White, P.J.; Kauffman, Matthew J.

2018-01-01

Each spring, migratory herbivores around the world track or ‘surf’ green waves of newly emergent vegetation to distant summer or wet‐season ranges. This foraging tactic may help explain the great abundance of migratory herbivores on many seasonal landscapes. However, the underlying fitness benefits of this life‐history strategy remain poorly understood. A fundamental prediction of the green‐wave hypothesis is that migratory herbivores obtain fitness benefits from surfing waves of newly emergent vegetation more closely than their resident counterparts. Here we evaluate whether this behavior increases body‐fat levels – a critically important correlate of reproduction and survival for most ungulates – in elk Cervus elaphus of the Greater Yellowstone Ecosystem. Using satellite imagery and GPS tracking data, we found evidence that migrants (n = 23) indeed surfed the green wave, occupying sites 12.7 days closer to peak green‐up than residents (n = 16). Importantly, individual variation in surfing may help account for up to 6 kg of variation in autumn body‐fat levels. Our findings point to a pathway for anthropogenic changes to the green wave (e.g. climate change) or migrants’ ability to surf it (e.g. development) to impact migratory populations. To explore this possibility, we evaluated potential population‐level consequences of constrained surfing with a heuristic model. If green‐wave surfing deteriorates by 5–15 days from observed, our model predicts up to a 20% decrease in pregnancy rates, a 2.5% decrease in population growth, and a 30% decrease in abundance over 50 years. By linking green‐wave surfing to fitness and illustrating potential effects on population growth, our study provides new insights into the evolution of migratory behavior and the prospects for the persistence of migratory ungulate populations in a changing world.

A role for Heparan Sulfate in Viral Surfing

PubMed Central

Oh, Myung-Jin; Akhtar, Jihan; Desai, Prashant; Shukla, Deepak

2009-01-01

Heparan sulfate (HS) moieties on cell surfaces are known to provide attachment sites for many viruses including herpes simplex virus type-1 (HSV-1). Here we demonstrate that cells respond to HSV-1 infection by promoting filopodia formation. Filopodia express HS and are subsequently utilized for the transport of HSV-1 virions to cell bodies in a surfing-like phenomenon, which is facilitated by the underlying actin cytoskeleton and is regulated by transient activation of a small Rho GTPase, Cdc42. We also demonstrate that interaction between a highly conserved herpesvirus envelope glycoprotein B (gB) and HS is required for surfing. A HSV-1 mutant that lacks gB fails to surf and quantum-dots conjugated with gB demonstrate surfing-like movements. Our data demonstrates a novel use of a common receptor, HS, which could also be exploited by multiple viruses and quite possibly, many additional ligands for transport along the plasma membrane. PMID:19909728

Multichannel imager for littoral zone characterization

NASA Astrophysics Data System (ADS)

Podobna, Yuliya; Schoonmaker, Jon; Dirbas, Joe; Sofianos, James; Boucher, Cynthia; Gilbert, Gary

2010-04-01

This paper describes an approach to utilize a multi-channel, multi-spectral electro-optic (EO) system for littoral zone characterization. Advanced Coherent Technologies, LLC (ACT) presents their EO sensor systems for the surf zone environmental assessment and potential surf zone target detection. Specifically, an approach is presented to determine a Surf Zone Index (SZI) from the multi-spectral EO sensor system. SZI provides a single quantitative value of the surf zone conditions delivering an immediate understanding of the area and an assessment as to how well an airborne optical system might perform in a mine countermeasures (MCM) operation. Utilizing consecutive frames of SZI images, ACT is able to measure variability over time. A surf zone nomograph, which incorporates targets, sensor, and environmental data, including the SZI to determine the environmental impact on system performance, is reviewed in this work. ACT's electro-optical multi-channel, multi-spectral imaging system and test results are presented and discussed.

Social Networking Sites' Influence on Travelers' Authentic Experience a Case Study of Couch Surfing

ERIC Educational Resources Information Center

Liu, Xiao

2013-01-01

This study explored travelers' experiences in the era of network hospitality 2.0 using CouchSurfing.org as a case study. The following research questions guided this study: 1) what experience does CouchSurfing create for travelers before, during and after their travel? 2) how does couch surfers' experience relate to authenticity in context of…

Strong regularities in world wide web surfing

PubMed

Huberman; Pirolli; Pitkow; Lukose

1998-04-03

One of the most common modes of accessing information in the World Wide Web is surfing from one document to another along hyperlinks. Several large empirical studies have revealed common patterns of surfing behavior. A model that assumes that users make a sequence of decisions to proceed to another page, continuing as long as the value of the current page exceeds some threshold, yields the probability distribution for the number of pages that a user visits within a given Web site. This model was verified by comparing its predictions with detailed measurements of surfing patterns. The model also explains the observed Zipf-like distributions in page hits observed at Web sites.

Integration of heterogeneous features for remote sensing scene classification

NASA Astrophysics Data System (ADS)

Wang, Xin; Xiong, Xingnan; Ning, Chen; Shi, Aiye; Lv, Guofang

2018-01-01

Scene classification is one of the most important issues in remote sensing (RS) image processing. We find that features from different channels (shape, spectral, texture, etc.), levels (low-level and middle-level), or perspectives (local and global) could provide various properties for RS images, and then propose a heterogeneous feature framework to extract and integrate heterogeneous features with different types for RS scene classification. The proposed method is composed of three modules (1) heterogeneous features extraction, where three heterogeneous feature types, called DS-SURF-LLC, mean-Std-LLC, and MS-CLBP, are calculated, (2) heterogeneous features fusion, where the multiple kernel learning (MKL) is utilized to integrate the heterogeneous features, and (3) an MKL support vector machine classifier for RS scene classification. The proposed method is extensively evaluated on three challenging benchmark datasets (a 6-class dataset, a 12-class dataset, and a 21-class dataset), and the experimental results show that the proposed method leads to good classification performance. It produces good informative features to describe the RS image scenes. Moreover, the integration of heterogeneous features outperforms some state-of-the-art features on RS scene classification tasks.

Qualitative task analysis to enhance sports characterization: a surfing case study.

PubMed

Moreira, Miguel; Peixoto, César

2014-09-29

The aim of this study was to develop a Matrix of Analysis for Sports Tasks (MAST), regardless of the sports activity, based on practice classification and task analysis. Being this a qualitative research our main question was: in assessing sports' structure is it possible to make the characterization of any discipline through context and individuals' behaviours? The sample was within a surf discipline in a competition flowing having 5 of the top 16 Portuguese surfers training together. Based on a qualitative method, studying the surf as the main activity was an interpretative study case. The MAST was applied in four phases: taxonomy; tasks and context description; task analysis; teaching and performance strategies. Its application allowed the activities' characterization through the observation, surfer's opinions and bibliographical support. The triangulation of the data was used as an information data treatment. The elements were classified by the challenges proposed to the practitioners and the taxonomy was constituted by the sport activities, group, modality and discipline. Surf is a discipline of surfing which is a sliding sport modality, therefore, a nature sport. In the context description, we had the wave's components and constraints and the surfboards' qualities. Through task analysis we obtained a taxonomy of surf manoeuvres. The structural and functional analysis allowed finding solutions for learning of surf techniques with trampoline and skateboards because these fit in sliding sports. MAST makes possible the development of strategies that benefit teaching and performance intervention.

Estuary-dependence of larval fishes in a non-estuary associated South African surf zone: evidence for continuity of surf assemblages

NASA Astrophysics Data System (ADS)

Strydom, Nadine A.; d'Hotman, Bruce D.

2005-04-01

Larval fishes were collected in the Cape Padrone surf zone on the southeast coast of South Africa, using a modified small-mesh seine net. The aim of the study was to assess the composition of fish larvae, with respect to their association with estuaries, in a surf zone that was not in close proximity to an estuary (>5 km). Sampling took place bimonthly during diurnal spring low tides between March and July 2003. In total, 544 fish were caught in the surf zone, comprising 14 families represented by 19 positively identified species, as well as an additional two species that were differentiated but remain unidentified. The families Mugilidae (65%) and Sparidae (26%) dominated the larval catch. The majority of larval fishes caught were in the postflexion stage of development, although some early juveniles were also caught. Body lengths of fish larvae ranged between 2 and 28 mm, with the majority of larvae at the recruitment size for the species. A high proportion of the fish species caught were estuary-dependent. Estuary-dependent marine fish larvae (categories I, II and IV) comprised 68% of total catch by species and 98% by number of individuals. Exclusively marine species (category III) were encountered in low numbers in the surf. The present study provides evidence for continuity in temperate South African surf zones in terms of domination by estuary-dependent larvae and reasons for this pattern are discussed.

Qualitative Task Analysis to Enhance Sports Characterization: A Surfing Case Study

PubMed Central

Moreira, Miguel; Peixoto, César

2014-01-01

The aim of this study was to develop a Matrix of Analysis for Sports Tasks (MAST), regardless of the sports activity, based on practice classification and task analysis. Being this a qualitative research our main question was: in assessing sports’ structure is it possible to make the characterization of any discipline through context and individuals’ behaviours? The sample was within a surf discipline in a competition flowing having 5 of the top 16 Portuguese surfers training together. Based on a qualitative method, studying the surf as the main activity was an interpretative study case. The MAST was applied in four phases: taxonomy; tasks and context description; task analysis; teaching and performance strategies. Its application allowed the activities’ characterization through the observation, surfer’s opinions and bibliographical support. The triangulation of the data was used as an information data treatment. The elements were classified by the challenges proposed to the practitioners and the taxonomy was constituted by the sport activities, group, modality and discipline. Surf is a discipline of surfing which is a sliding sport modality, therefore, a nature sport. In the context description, we had the wave’s components and constraints and the surfboards’ qualities. Through task analysis we obtained a taxonomy of surf manoeuvres. The structural and functional analysis allowed finding solutions for learning of surf techniques with trampoline and skateboards because these fit in sliding sports. MAST makes possible the development of strategies that benefit teaching and performance intervention. PMID:25414757

DARLA: Data Assimilation and Remote Sensing for Littoral Applications

DTIC Science & Technology

2011-09-30

measurements from the Surf Zone Optics (SZO) experiment in September, 2011. Since optical reflectance saturates for surf zone bubble depths greater than...Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents...pilot experiment at Duck, NC during the Surf Zone Optics DRI Experiment in September, 2010 and participated in planning of the upcoming RIVET DRI

Adaptive Highlighting of Links to Assist Surfing on the Internet

DTIC Science & Technology

2002-01-01

search engines do not offer a satisfactory solution, their indexing cycle is long and creates a time lag of about one month. Moreover, sometimes search engines offer a huge amount of documents, which is hard to constrain and to increase the ratio of relevant information. A novel AI-assisted surfing method, which highlights links during surfing is studied here. The method makes use

76 FR 55566 - Safety Zones; Fireworks Displays and Surfing Events in Captain of the Port Long Island Sound Zone

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-08

...-AA00 Safety Zones; Fireworks Displays and Surfing Events in Captain of the Port Long Island Sound Zone... zones for marine events within the Captain of the Port (COTP) Long Island Sound Zone for a surfing event... unless authorized by the COTP Sector Long Island Sound. DATES: This rule is effective in the CFR on...

SURF: Taking Sustainable Remediation from Concept to Standard Operating Procedure (Invited)

NASA Astrophysics Data System (ADS)

Smith, L. M.; Wice, R. B.; Torrens, J.

2013-12-01

Over the last decade, many sectors of industrialized society have been rethinking behavior and re-engineering practices to reduce consumption of energy and natural resources. During this time, green and sustainable remediation (GSR) has evolved from conceptual discussions to standard operating procedure for many environmental remediation practitioners. Government agencies and private sector entities have incorporated GSR metrics into their performance criteria and contracting documents. One of the early think tanks for the development of GSR was the Sustainable Remediation Forum (SURF). SURF brings together representatives of government, industry, consultancy, and academia to parse the means and ends of incorporating societal and economic considerations into environmental cleanup projects. Faced with decades-old treatment programs with high energy outputs and no endpoints in sight, a small group of individuals published the institutional knowledge gathered in two years of ad hoc meetings into a 2009 White Paper on sustainable remediation drivers, practices, objectives, and case studies. Since then, SURF has expanded on those introductory topics, publishing its Framework for Integrating Sustainability into Remediation Projects, Guidance for Performing Footprint Analyses and Life-Cycle Assessments for the Remediation Industry, a compendium of metrics, and a call to improve the integration of land remediation and reuse. SURF's research and members have also been instrumental in the development of additional guidance through ASTM International and the Interstate Technology and Regulatory Council. SURF's current efforts focus on water reuse, the international perspective on GSR (continuing the conversations that were the basis of SURF's December 2012 meeting at the National Academy of Sciences in Washington, DC), and ways to capture and evaluate the societal benefits of site remediation. SURF also promotes and supports student chapters at universities across the US, encouraging the incorporation of sustainability concepts into environmental science and engineering in undergraduate curricula and graduate research, and student participation at professional conferences. This presentation will provide an overview of the evolution of GSR to-date and a history of SURF's technical and outreach work. Examples will be provided--using both qualitative and quantitative metrics--that document and support the benefits of GSR.

Habitats used by black and surf scoters in eastern North America as determined by satellite radio telemetry

USGS Publications Warehouse

Perry, M.C.; Kidwell, D.M.; Wells-Berlin, A. M.; Lohnes, E.J.R.; Olsen, Glenn H.; Osenton, P.C.

2005-01-01

Satellite radio telemetry was used to determine the movements and habitats of black scoters (Melanitta nigra) and surf scoters (Melanitta perspicillata) in eastern North America. A total of 21 surf scoters were instrumented during five years (2001-05) and 32 black scoters were instrumented during three years (2002-04) with implanted PTT 100 satellite transmitters (39 g) with external antenna. Nesting habitat of black scoters was more open than surf scoters (44% vs. 11%), whereas nesting habitat for surf scoters was located in more forested areas (66% vs. 20%). Locations of black scoters in breeding areas on average were at significantly higher latitude and lower elevations than sites used by surf scoters. Satellite telemetry determined that James Bay was the major molting area for male black and surf scoters, although some males molted along the coast of Labrador-Newfoundland. Black scoters instrumented on the Restigouche River, which is a major staging area, were widely distributed along the Atlantic Coast from Cape Cod to Georgia during winter. Major wintering areas for black scoters were Cape Cod (Martha's Vineyard and Nantucket Island), Long Island, and New Jersey. In these northern marine wintering areas, black scoters were located farther from shore (4.2 km) and in deeper water (8.3 m) than black scoters in more southern estuarine areas, where distance from shore was 3.1 km and water depth was 5.2 m. Surf scoters instrumented in Chesapeake Bay in late winter showed a strong tendency to return to the Bay the following winter after they had migrated to and from breeding areas. In Chesapeake Bay, black scoters and surf scoters were located mostly in mesohaline areas that had similar water depths (5.1 m vs. 7.5 m) and distances from shore (3.0 km vs. 2.9 km). Distance from shore and depth of water increased over time during the winter for both species. Updated information from the ARGOS Systems aboard the NOAA satellites on scoter movements was made accessible on the Patuxent Website.

Robust digital image watermarking using distortion-compensated dither modulation

NASA Astrophysics Data System (ADS)

Li, Mianjie; Yuan, Xiaochen

2018-04-01

In this paper, we propose a robust feature extraction based digital image watermarking method using Distortion- Compensated Dither Modulation (DC-DM). Our proposed local watermarking method provides stronger robustness and better flexibility than traditional global watermarking methods. We improve robustness by introducing feature extraction and DC-DM method. To extract the robust feature points, we propose a DAISY-based Robust Feature Extraction (DRFE) method by employing the DAISY descriptor and applying the entropy calculation based filtering. The experimental results show that the proposed method achieves satisfactory robustness under the premise of ensuring watermark imperceptibility quality compared to other existing methods.

Australian surf life-saving and the "forgotten members".

PubMed

Jaggard, E

1999-01-01

The history and mythology of Australia's surf life-saving movement portray the surf life-saver as an inter and postwar national symbol, an image of manhood often regarded as the successor to that of the bushman and the digger. According to this viewpoint, women had no place on the beaches, being supportive fundraisers and social organisers. In fact, almost from surf life-saving's commencement in 1906, many women refused to be confined to these roles; they participated in their own competitions, were proficient in rescue techniques and were proud to belong to the movement, thus contradicting the widely shared belief that their active involvement began only in 1980 when they were granted full membership.

Assessing the Prevalence of Traumatic Head Injury amongst Recreational Surfers in the United States.

PubMed

Swinney, Christian

2015-12-01

Surfing is a popular recreational sport that carries a substantial risk of injury. Although head injuries are frequently documented in the surfing population, an in depth assessment of the prevalence of surfing-related head injury has not been reported. A web-based survey was conducted in May of 2015. Participants were asked a series of questions regarding surfing-related injuries and demographic characteristics. A total of 50 responses were obtained, of which 35 (70%) reported sustaining a head injury. The most common injury was laceration of the head/face (n=27), followed by concussion (n=13). Other injuries, such as skull fracture and broken nose, were also reported. Only 2 of the 50 participants reported wearing a protective helmet. Neurosurgical intervention was required in 2 instances. Increased emphasis on preventative measures by the medical community may reduce the future incidence of such injuries. Medical professionals should be aware of the most common forms of injury sustained by the surfing population in order to better recognize and treat these conditions.

Space Debris Surfaces (Computer Code): Probability of No Penetration Versus Impact Velocity and Obliquity

NASA Technical Reports Server (NTRS)

Elfer, N.; Meibaum, R.; Olsen, G.

1995-01-01

A unique collection of computer codes, Space Debris Surfaces (SD_SURF), have been developed to assist in the design and analysis of space debris protection systems. SD_SURF calculates and summarizes a vehicle's vulnerability to space debris as a function of impact velocity and obliquity. An SD_SURF analysis will show which velocities and obliquities are the most probable to cause a penetration. This determination can help the analyst select a shield design that is best suited to the predominant penetration mechanism. The analysis also suggests the most suitable parameters for development or verification testing. The SD_SURF programs offer the option of either FORTRAN programs or Microsoft-EXCEL spreadsheets and macros. The FORTRAN programs work with BUMPERII. The EXCEL spreadsheets and macros can be used independently or with selected output from the SD_SURF FORTRAN programs. Examples will be presented of the interaction between space vehicle geometry, the space debris environment, and the penetration and critical damage ballistic limit surfaces of the shield under consideration.

A role for heparan sulfate in viral surfing

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

Oh, Myung-Jin; Akhtar, Jihan; Desai, Prashant

2010-01-01

Heparan sulfate (HS) moieties on cell surfaces are known to provide attachment sites for many viruses including herpes simplex virus type-1 (HSV-1). Here, we demonstrate that cells respond to HSV-1 infection by enhancing filopodia formation. Filopodia express HS and are subsequently utilized for the transport of HSV-1 virions to cell bodies in a surfing-like phenomenon, which is facilitated by the underlying actin cytoskeleton and is regulated by transient activation of a small Rho GTPase, Cdc42. We also demonstrate that interaction between a highly conserved herpesvirus envelope glycoprotein B (gB) and HS is required for surfing. A HSV-1 mutant that lacksmore » gB fails to surf and quantum dots conjugated with gB demonstrate surfing-like movements. Our data demonstrates a novel use of a common receptor, HS, which could also be exploited by multiple viruses and quite possibly, many additional ligands for transport along the plasma membrane.« less

The effects of surfing and the natural environment on the well-being of combat veterans.

PubMed

Caddick, Nick; Smith, Brett; Phoenix, Cassandra

2015-01-01

Although researchers have identified the benefits of physical activity on well-being, there is little evidence concerning the effects of nature-based physical activity. We investigated the effect of one nature-based activity-surfing-on the well-being of combat veterans experiencing posttraumatic stress disorder (PTSD). We conducted interviews and participant observations with a group of combat veterans belonging to a United Kingdom-based veterans' surfing charity. Our primary analytical approach was dialogical narrative analysis. Based on our rigorous analysis and findings, we suggest that surfing facilitated a sense of respite from PTSD. Respite was a fully embodied feeling of release from suffering that was cultivated through surfing and shaped by the stories veterans told of their experiences. We significantly extend previous knowledge on physical activity, combat veterans, and PTSD by highlighting how nature-based physical activity, encapsulated in the conceptual notion of the "blue gym," can promote well-being among combat veterans. © The Author(s) 2014.

a Performance Comparison of Feature Detectors for Planetary Rover Mapping and Localization

NASA Astrophysics Data System (ADS)

Wan, W.; Peng, M.; Xing, Y.; Wang, Y.; Liu, Z.; Di, K.; Teng, B.; Mao, X.; Zhao, Q.; Xin, X.; Jia, M.

2017-07-01

Feature detection and matching are key techniques in computer vision and robotics, and have been successfully implemented in many fields. So far there is no performance comparison of feature detectors and matching methods for planetary mapping and rover localization using rover stereo images. In this research, we present a comprehensive evaluation and comparison of six feature detectors, including Moravec, Förstner, Harris, FAST, SIFT and SURF, aiming for optimal implementation of feature-based matching in planetary surface environment. To facilitate quantitative analysis, a series of evaluation criteria, including distribution evenness of matched points, coverage of detected points, and feature matching accuracy, are developed in the research. In order to perform exhaustive evaluation, stereo images, simulated under different baseline, pitch angle, and interval of adjacent rover locations, are taken as experimental data source. The comparison results show that SIFT offers the best overall performance, especially it is less sensitive to changes of image taken at adjacent locations.

SERDP and ESTCP Workshop on Technology Needs for the Characterization, Management, and Remediation of Military Munitions in Underwater Environments

DTIC Science & Technology

2007-10-01

5.3.1.1 Study of Surf Zone Environment........................................... 5-6 5.3.2 Research Needs: High Priority...Detection of Smaller Munitions Items Study of Surf Zone Environment Improve Navigation Error Analysis Develop Cooperative Cued Platforms...towbodies, AUVs, ROVs, HOVs, and divers. Surveys in high energy surf zones present unique difficulties. Finally, participants stressed that the survey

Analysis of injuries' prevalence in surfers from Paraná seacoast

PubMed Central

de Moraes, Gabriela Chueiri; Guimarães, Ana Tereza Bittencourt; Gomes, Anna Raquel Silveira

2013-01-01

OBJECTIVE: to analyze the prevalence of musculoskeletal injuries of surfers from the Paraná's seacoast. METHODS: Sixty men (27 ± 6 years) completed a surf semi structured questionnaire (category, time of daily practice, frequency and exercises performed before and/or after surfing) and characteristics of injuries induced by this sport. A descriptive analysis of the data on distribution of the relative frequency was performed. RESULTS: It was found that 70% of the respondents practiced surfing as a relaxing activity, 28% were amateurs and 2% were professionals, who were surfing for 10 years or more. Most of them surfed between 2 to 4 times a week during 2 to 4 hours a day. The most common exercise performed before surfing was upper and lower limbs stretching and no exercises at all was done after practice. The most common injury was contusion (29%), lower limb was the most affected segment (46%) and the most common cause of injury was due to contact with the board (52%). The interruption period mostly reported was 1-3 months and the most frequent treatment was taking medicines. CONCLUSIONS: Recreational was the predominant category of surfers with lower limb's contusion as the most common musculoskeletal injury, resulting from contact with the board, being treated with medication and rest. Level of Evidence II, Retrospective Study. PMID:24453671

Clinical methods to quantify trunk mobility in an elite male surfing population.

PubMed

Furness, James; Climstein, Mike; Sheppard, Jeremy M; Abbott, Allan; Hing, Wayne

2016-05-01

Thoracic mobility in the sagittal and horizontal planes are key requirements in the sport of surfing; however to date the normal values of these movements have not yet been quantified in a surfing population. To develop a reliable method to quantify thoracic mobility in the sagittal plane; to assess the reliability of an existing thoracic rotation method, and quantify thoracic mobility in an elite male surfing population. Clinical Measurement, reliability and comparative study. A total of 30 subjects were used to determine the reliability component. 15 elite surfers were used as part of a comparative analysis with age and gender matched controls. Intraclass correlation coefficient values ranged between 0.95-0.99 (95% CI; 0.89-0.99) for both thoracic methods. The elite surfing group had significantly (p ≤ 0.05) greater rotation than the comparative group (mean rotation 63.57° versus 40.80°, respectively). This study has illustrated reliable methods to assess the thoracic spine in the sagittal plane and thoracic rotation. It has also quantified ROM in a surfing cohort; identifying thoracic rotation as a key movement. This information may provide clinicians, coaches and athletic trainers with imperative information regarding the importance of maintaining adequate thoracic rotation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterisation of regional skin temperatures in recreational surfers wearing a 2-mm wetsuit.

PubMed

Corona, Luis J; Simmons, Grant H; Nessler, Jeff A; Newcomer, Sean C

2018-05-01

The purpose of this study was to investigate skin temperatures across surfers' bodies while wearing a wetsuit during recreational surfing. Forty-six male recreational surfers participated in this study. Participants were instrumented with eight wireless iButton thermal sensors for the measurement of skin temperature, a Polar RCX5 heart rate monitor and a 2-mm full wetsuit. Following instrumentation, participants were instructed to engage in recreational surfing activities as normal. Significant differences (p < 0.001) in skin temperature (T sk ) were found across the body while wearing a wetsuit during recreational surfing. In addition, regional skin temperature changed across the session for several regions of the body (p < 0.001), and the magnitude of these changes varied significantly between regions. We show for the first time that significant differences exist in skin temperature across the body while wearing a wetsuit during a typical recreational surfing session. These findings may have implications for future wetsuit design. Practitioner Summary: This study investigated the impact of wearing a wetsuit during recreational surfing on regional skin temperatures. Results from this study suggest that skin temperatures differ significantly across the body while wearing a 2-mm wetsuit during recreational surfing. These findings may have implications for future wetsuit design.

Peripheral neuropathy in genetically characterized patients with mitochondrial disorders: A study from south India.

PubMed

Bindu, Parayil Sankaran; Govindaraju, Chikanna; Sonam, Kothari; Nagappa, Madhu; Chiplunkar, Shwetha; Kumar, Rakesh; Gayathri, Narayanappa; Bharath, M M Srinivas; Arvinda, Hanumanthapura R; Sinha, Sanjib; Khan, Nahid Akthar; Govindaraj, Periyasamy; Nunia, Vandana; Paramasivam, Arumugam; Thangaraj, Kumarasamy; Taly, Arun B

2016-03-01

There are relatively few studies, which focus on peripheral neuropathy in large cohorts of genetically characterized patients with mitochondrial disorders. This study sought to analyze the pattern of peripheral neuropathy in a cohort of patients with mitochondrial disorders. The study subjects were derived from a cohort of 52 patients with a genetic diagnosis of mitochondrial disorders seen over a period of 8 years (2006-2013). All patients underwent nerve conduction studies and those patients with abnormalities suggestive of peripheral neuropathy were included in the study. Their phenotypic features, genotype, pattern of peripheral neuropathy and nerve conduction abnormalities were analyzed retrospectively. The study cohort included 18 patients (age range: 18 months-50 years, M:F- 1.2:1).The genotype included mitochondrial DNA point mutations (n=11), SURF1 mutations (n=4) and POLG1(n=3). Axonal neuropathy was noted in 12 patients (sensori-motor:n=4; sensory:n=4; motor:n=4) and demyelinating neuropathy in 6. Phenotype-genotype correlations revealed predominant axonal neuropathy in mtDNA point mutations and demyelinating neuropathy in SURF1. Patients with POLG related disorders had both sensory ataxic neuropathy and axonal neuropathy. A careful analysis of the family history, clinical presentation, biochemical, histochemical and structural analysis may help to bring out the mitochondrial etiology in patients with peripheral neuropathy and may facilitate targeted gene testing. Presence of demyelinating neuropathy in Leigh's syndrome may suggest underlying SURF1 mutations. Sensory ataxic neuropathy with other mitochondrial signatures should raise the possibility of POLG related disorder. Copyright © 2015. Published by Elsevier B.V.

SurF: an innovative framework in biosecurity and animal health surveillance evaluation.

PubMed

Muellner, Petra; Watts, Jonathan; Bingham, Paul; Bullians, Mark; Gould, Brendan; Pande, Anjali; Riding, Tim; Stevens, Paul; Vink, Daan; Stärk, Katharina Dc

2018-05-16

Surveillance for biosecurity hazards is being conducted by the New Zealand Competent Authority, the Ministry for Primary Industries (MPI) to support New Zealand's biosecurity system. Surveillance evaluation should be an integral part of the surveillance life cycle, as it provides a means to identify and correct problems and to sustain and enhance the existing strengths of a surveillance system. The surveillance evaluation Framework (SurF) presented here was developed to provide a generic framework within which the MPI biosecurity surveillance portfolio, and all of its components, can be consistently assessed. SurF is an innovative, cross-sectoral effort that aims to provide a common umbrella for surveillance evaluation in the animal, plant, environment and aquatic sectors. It supports the conduct of the following four distinct components of an evaluation project: (i) motivation for the evaluation, (ii) scope of the evaluation, (iii) evaluation design and implementation and (iv) reporting and communication of evaluation outputs. Case studies, prepared by MPI subject matter experts, are included in the framework to guide users in their assessment. Three case studies were used in the development of SurF in order to assure practical utility and to confirm usability of SurF across all included sectors. It is anticipated that the structured approach and information provided by SurF will not only be of benefit to MPI but also to other New Zealand stakeholders. Although SurF was developed for internal use by MPI, it could be applied to any surveillance system in New Zealand or elsewhere. © 2018 2018 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

Research on three-dimensional reconstruction method based on binocular vision

NASA Astrophysics Data System (ADS)

Li, Jinlin; Wang, Zhihui; Wang, Minjun

2018-03-01

As the hot and difficult issue in computer vision, binocular stereo vision is an important form of computer vision,which has a broad application prospects in many computer vision fields,such as aerial mapping,vision navigation,motion analysis and industrial inspection etc.In this paper, a research is done into binocular stereo camera calibration, image feature extraction and stereo matching. In the binocular stereo camera calibration module, the internal parameters of a single camera are obtained by using the checkerboard lattice of zhang zhengyou the field of image feature extraction and stereo matching, adopted the SURF operator in the local feature operator and the SGBM algorithm in the global matching algorithm are used respectively, and the performance are compared. After completed the feature points matching, we can build the corresponding between matching points and the 3D object points using the camera parameters which are calibrated, which means the 3D information.

Analysis to feature-based video stabilization/registration techniques within application of traffic data collection

NASA Astrophysics Data System (ADS)

Sadat, Mojtaba T.; Viti, Francesco

2015-02-01

Machine vision is rapidly gaining popularity in the field of Intelligent Transportation Systems. In particular, advantages are foreseen by the exploitation of Aerial Vehicles (AV) in delivering a superior view on traffic phenomena. However, vibration on AVs makes it difficult to extract moving objects on the ground. To partly overcome this issue, image stabilization/registration procedures are adopted to correct and stitch multiple frames taken of the same scene but from different positions, angles, or sensors. In this study, we examine the impact of multiple feature-based techniques for stabilization, and we show that SURF detector outperforms the others in terms of time efficiency and output similarity.

The calibration of photographic and spectroscopic films. The utilization of the digital image processor in the determination of aging of the surf clam (Spisula solidissima)

NASA Technical Reports Server (NTRS)

Peters, Kevin A.; Hammond, Ernest C., Jr.

1987-01-01

The age of the surf clam (Spisula solidissima) can be determined with the use of the Digital Image Processor. This technique is used in conjunction with a modified method for aging, refined by John Ropes of the Woods Hole Laboratory, Massachusetts. This method utilizes a thinned sectioned chondrophore of the surf clam which contains annual rings. The rings of the chondrophore are then counted to determine age. By digitizing the chondrophore, the Digital Image Processor is clearly able to separate these annual rings more accurately. This technique produces an easier and more efficient way to count annual rings to determine the age of the surf clam.

Littoral assessment of mine burial signatures (LAMBS): buried-landmine hyperspectral data collections

NASA Astrophysics Data System (ADS)

Kenton, Arthur C.; Geci, Duane M.; McDonald, James A.; Ray, Kristofer J.; Thomas, Clayton M.; Holloway, John H., Jr.; Petee, Danny A.; Witherspoon, Ned H.

2003-09-01

The objective of the Office of Naval Research (ONR) Rapid Overt Reconnaissance (ROR) program and the Airborne Littoral Reconnaissance Technologies project's Littoral Assessment of Mine Burial Signatures (LAMBS) contract is to determine if electro-optical spectral discriminants exist that are useful for the detection of land mines located in littoral regions. Statistically significant buried mine overburden and background signature data were collected over a wide spectral range (0.35 to 14 μm) to identify robust spectral features that might serve as discriminants for new airborne sensor concepts. The LAMBS program further expands the hyperspectral database previously collected and analyzed on the U.S. Army's Hyperspectral Mine Detection Phenomenology program [see "Detection of Land Mines with Hyperspectral Data," and "Hyperspectral Mine Detection Phenomenology Program," Proc. SPIE Vol. 3710, pp 917-928 and 819-829, AeroSense April 1999] to littoral areas where tidal, surf, and wind action can additionally modify spectral signatures. This work summarizes the LAMBS buried mine collections conducted at three beach sites - an inland bay beach site (Eglin AFB, FL, Site A-22), an Atlantic beach site (Duck, NC), and a Gulf beach site (Eglin AFB, FL, Site A-15). Characteristics of the spectral signatures of the various dry and damp beach sands are presented. These are then compared to buried land mine signatures observed for the tested background types, burial ages, and environmental conditions experienced.

Mutations in SURF1 are important genetic causes of Leigh syndrome in Slovak patients.

PubMed

Danis, Daniel; Brennerova, Katarina; Skopkova, Martina; Kurdiova, Timea; Ukropec, Jozef; Stanik, Juraj; Kolnikova, Miriam; Gasperikova, Daniela

2018-04-01

Leigh syndrome is a progressive early onset neurodegenerative disease typically presenting with psychomotor regression, signs of brainstem and/or basal ganglia disease, lactic acidosis, and characteristic magnetic resonance imaging findings. At molecular level, deficiency of respiratory complexes and/or pyruvate dehydrogenase complex is usually observed. Nuclear gene SURF1 encodes an assembly factor for cytochrome c-oxidase complex of the respiratory chain and autosomal recessive mutations in SURF1 are one of the most frequent causes of cytochrome c-oxidase-related Leigh syndrome cases. Here, we aimed to elucidate the genetic basis of Leigh syndrome in three Slovak families. Three probands presenting with Leigh syndrome were selected for DNA analysis. The first proband, presenting with atypical LS onset without abnormal basal ganglia magnetic resonance imaging findings, was analyzed with whole exome sequencing. In the two remaining probands, SURF1 was screened by Sanger sequencing. Four different heterozygous mutations were identified in SURF1: c.312_321delinsAT:p.(Pro104Profs*1), c.588+1G>A, c.823_833+7del:p. (?) and c.845_846del:p.(Ser282Cysfs*9). All the mutations are predicted to have a loss-of-function effect. We identified disease-causing mutations in all three probands, which points to the important role of SURF1 gene in etiology of Leigh syndrome in Slovakia. Our data showed that patients with atypical Leigh syndrome phenotype without lesions in basal ganglia may benefit from the whole exome sequencing method. In the case of probands presenting the typical phenotype, Sanger sequencing of the SURF1 gene seems to be an effective method of DNA analysis.

surf3d: A 3-D finite-element program for the analysis of surface and corner cracks in solids subjected to mode-1 loadings

NASA Technical Reports Server (NTRS)

Raju, I. S.; Newman, J. C., Jr.

1993-01-01

A computer program, surf3d, that uses the 3D finite-element method to calculate the stress-intensity factors for surface, corner, and embedded cracks in finite-thickness plates with and without circular holes, was developed. The cracks are assumed to be either elliptic or part eliptic in shape. The computer program uses eight-noded hexahedral elements to model the solid. The program uses a skyline storage and solver. The stress-intensity factors are evaluated using the force method, the crack-opening displacement method, and the 3-D virtual crack closure methods. In the manual the input to and the output of the surf3d program are described. This manual also demonstrates the use of the program and describes the calculation of the stress-intensity factors. Several examples with sample data files are included with the manual. To facilitate modeling of the user's crack configuration and loading, a companion program (a preprocessor program) that generates the data for the surf3d called gensurf was also developed. The gensurf program is a three dimensional mesh generator program that requires minimal input and that builds a complete data file for surf3d. The program surf3d is operational on Unix machines such as CRAY Y-MP, CRAY-2, and Convex C-220.

Ichthyoplankton in a southern african surf zone: Nursery area for the postlarvae of estuarine associated fish species?

NASA Astrophysics Data System (ADS)

Whitfield, A. K.

1989-12-01

The surf zone ichthyoplankton of Swartvlei Bay was studied between February 1986 and June 1987, with particular emphasis on its potential role as a nursery area for estuarine associated marine fish species. Larvae and/or postlarvae of 16 families were identified from the surf zone, with the Gobiidae, Soleidae, Sparidae and Mugilidae comprising 85·7% of all teleosts sampled. The postlarvae of several taxa (including the six most common species), which utilize the Swartvlei estuary as a juvenile nursery area, were abundant in the surf zone. Conversely, species which are common in nearshore marine waters as juveniles and adults, but seldom enter estuaries, totalled less than 8% of the surf zone ichthyoplankton assemblage. Larval and postlarval densities peaked during summer when water temperatures exceeded 19°C and the estuary mouth was open. Concentrations of ichthyoplankton were highest at those sampling stations closest to the estuary mouth during the summer period. Diel changes in total catches revealed no significant difference between day and night densities; but of the four major taxa, the Mugilidae and Sparidae tended to be more abundant during the day, the Gobiidae at night and the Soleidae showed no distinct pattern. Results from a 24 h sampling session indicated that tidal phase may also be important in governing ichthyoplankton abundance in the surf zone.

Advancing Bag-of-Visual-Words Representations for Lesion Classification in Retinal Images

PubMed Central

Pires, Ramon; Jelinek, Herbert F.; Wainer, Jacques; Valle, Eduardo; Rocha, Anderson

2014-01-01

Diabetic Retinopathy (DR) is a complication of diabetes that can lead to blindness if not readily discovered. Automated screening algorithms have the potential to improve identification of patients who need further medical attention. However, the identification of lesions must be accurate to be useful for clinical application. The bag-of-visual-words (BoVW) algorithm employs a maximum-margin classifier in a flexible framework that is able to detect the most common DR-related lesions such as microaneurysms, cotton-wool spots and hard exudates. BoVW allows to bypass the need for pre- and post-processing of the retinographic images, as well as the need of specific ad hoc techniques for identification of each type of lesion. An extensive evaluation of the BoVW model, using three large retinograph datasets (DR1, DR2 and Messidor) with different resolution and collected by different healthcare personnel, was performed. The results demonstrate that the BoVW classification approach can identify different lesions within an image without having to utilize different algorithms for each lesion reducing processing time and providing a more flexible diagnostic system. Our BoVW scheme is based on sparse low-level feature detection with a Speeded-Up Robust Features (SURF) local descriptor, and mid-level features based on semi-soft coding with max pooling. The best BoVW representation for retinal image classification was an area under the receiver operating characteristic curve (AUC-ROC) of 97.8% (exudates) and 93.5% (red lesions), applying a cross-dataset validation protocol. To assess the accuracy for detecting cases that require referral within one year, the sparse extraction technique associated with semi-soft coding and max pooling obtained an AUC of 94.22.0%, outperforming current methods. Those results indicate that, for retinal image classification tasks in clinical practice, BoVW is equal and, in some instances, surpasses results obtained using dense detection (widely believed to be the best choice in many vision problems) for the low-level descriptors. PMID:24886780

Comparison of recreational health risks associated with surfing and swimming in dry weather and post-storm conditions at Southern California beaches using quantitative microbial risk assessment (QMRA).

PubMed

Tseng, Linda Y; Jiang, Sunny C

2012-05-01

Southern California is an increasingly urbanized hotspot for surfing, thus it is of great interest to assess the human illness risks associated with this popular ocean recreational water sport from exposure to fecal bacteria contaminated coastal waters. Quantitative microbial risk assessments were applied to eight popular Southern California beaches using readily available enterococcus and fecal coliform data and dose-response models to compare health risks associated with surfing during dry weather and storm conditions. The results showed that the level of gastrointestinal illness risks from surfing post-storm events was elevated, with the probability of exceeding the US EPA health risk guideline up to 28% of the time. The surfing risk was also elevated in comparison with swimming at the same beach due to ingestion of greater volume of water. The study suggests that refinement of dose-response model, improving monitoring practice and better surfer behavior surveillance will improve the risk estimation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessing the Prevalence of Traumatic Head Injury amongst Recreational Surfers in the United States

PubMed Central

2015-01-01

Surfing is a popular recreational sport that carries a substantial risk of injury. Although head injuries are frequently documented in the surfing population, an in depth assessment of the prevalence of surfing-related head injury has not been reported. A web-based survey was conducted in May of 2015. Participants were asked a series of questions regarding surfing-related injuries and demographic characteristics. A total of 50 responses were obtained, of which 35 (70%) reported sustaining a head injury. The most common injury was laceration of the head/face (n=27), followed by concussion (n=13). Other injuries, such as skull fracture and broken nose, were also reported. Only 2 of the 50 participants reported wearing a protective helmet. Neurosurgical intervention was required in 2 instances. Increased emphasis on preventative measures by the medical community may reduce the future incidence of such injuries. Medical professionals should be aware of the most common forms of injury sustained by the surfing population in order to better recognize and treat these conditions. PMID:26668771

Non-Hydrostatic Modelling of Waves and Currents over Subtle Bathymetric Features

NASA Astrophysics Data System (ADS)

Gomes, E.; Mulligan, R. P.; McNinch, J.

2014-12-01

Localized areas with high rates of shoreline erosion on beaches, referred to as erosional hotspots, can occur near clusters of relict shore-oblique sandbars. Wave transformation and wave-driven currents over these morphological features could provide an understanding of the hydrodynamic-morphologic coupling mechanism that connects them to the occurrence of erosional hotspots. To investigate this, we use the non-hydrostatic SWASH model that phase-resolves the free surface and fluid motions throughout the water column, allowing for high resolution of wave propagation and breaking processes. In this study we apply a coupled system of nested models including SWAN over a large domain of the North Carolina shelf with smaller nested SWASH domains in areas of interest to determine the hydrodynamic processes occurring over shore oblique bars. In this presentation we focus on a high resolution grid (10 vertical layers, 10 m horizontal resolution) applied to the Duck region with model validation from acoustic wave and current data, and observations from the Coastal Lidar And Radar Imaging System (CLARIS). By altering the bathymetry input for each model run based on bathymetric surveys and comparing the predicted and observed wave heights and current profiles, the effects of subtle bathymetric perturbations have on wave refraction, wave breaking, surf zone currents and vorticity are investigated. The ability to predict wave breaking and hydrodynamics with a non-hydrostatic model may improve our understanding of surf zone dynamics in relation to morphologic conditions.

Forcing and variability of nonstationary rip currents

USGS Publications Warehouse

Long, Joseph W.; H.T. Özkan-Haller,

2016-01-01

Surface wave transformation and the resulting nearshore circulation along a section of coast with strong alongshore bathymetric gradients outside the surf zone are modeled for a consecutive 4 week time period. The modeled hydrodynamics are compared to in situ measurements of waves and currents collected during the Nearshore Canyon Experiment and indicate that for the entire range of observed conditions, the model performance is similar to other studies along this stretch of coast. Strong alongshore wave height gradients generate rip currents that are observed by remote sensing data and predicted qualitatively well by the numerical model. Previous studies at this site have used idealized scenarios to link the rip current locations to undulations in the offshore bathymetry but do not explain the dichotomy between permanent offshore bathymetric features and intermittent rip current development. Model results from the month‐long simulation are used to track the formation and location of rip currents using hourly statistics, and results show that the direction of the incoming wave energy strongly controls whether rip currents form. In particular, most of the offshore wave spectra were bimodal and we find that the ratio of energy contained in each mode dictates rip current development, and the alongshore rip current position is controlled by the incident wave period. Additionally, model simulations performed with and without updating the nearshore morphology yield no significant change in the accuracy of the predicted surf zone hydrodyanmics indicating that the large‐scale offshore features (e.g., submarine canyon) predominately control the nearshore wave‐circulation system.

Atypical amyoplasia congenita in an infant with Leigh syndrome: a mitochondrial cause of severe contractures?

PubMed

Wilnai, Yael; Seaver, Laurie H; Enns, Gregory M

2012-09-01

Amyoplasia congenita is a distinct form of arthrogryposis with characteristic features including internally rotated and adducted shoulders, extended elbows, flexion, and ulnar deviation of the wrists, and adducted thumbs. Fetal hypokinesia, secondary to a variety of genetic conditions, neuromuscular disorders, and environmental agents, is associated with contractures. In order to increase our understanding of the phenotypic spectrum associated with SURF 1 deficiency, a common cause of mitochondrial respiratory chain complex IV deficiency and Leigh syndrome, we describe a now 6-year-old boy who presented in the neonatal period with amyoplasia congenita. His development was normal until age 10.5 months, at which time he developed severe hypotonia and choreoathetosis following an episode of viral gastroenteritis. Following the onset of neurological symptoms, he gradually developed severe kyphosis and lower limb contractures. Blood and cerebrospinal fluid lactate levels were elevated and head imaging showed characteristic features of Leigh syndrome. He was found to harbor two pathogenic heterozygous mutations in the SURF 1 gene. In this case, mitochondrial dysfunction and the resultant energy deficiency may have played a role in causing abnormal neuronal development during embryogenesis, causing arthrogryposis. A variety of mitochondrial respiratory chain complex deficiencies have been associated with contractures of varying severity. Therefore, mitochondrial disorders should be considered in the differential diagnosis of neonatal arthrogryposis, especially if other characteristic findings such as lactic acidemia or basal ganglia abnormalities are present. Copyright © 2012 Wiley Periodicals, Inc.

A pilot study of cognitive behaviour therapy for panic disorder augmented by panic surfing.

PubMed

Lamplugh, Claire; Berle, David; Milicevic, Denise; Starcevic, Vladan

2008-01-01

This pilot study reports the outcome of cognitive behaviour therapy for panic disorder augmented by panic surfing. This treatment approach encourages acceptance of feelings rather than control of symptoms and anxiety, at the same time also targeting catastrophic misinterpretations, bodily vigilance and safety-seeking behaviours. Eighteen participants completed a brief group treatment for panic disorder incorporating psychoeducation, panic surfing, interoceptive exposure, graded exposure and cognitive restructuring. Significant improvements occurred over the course of this treatment and were maintained at a 1-month follow-up. Results suggest that cognitive behaviour therapy augmented by panic surfing may be effective in the treatment of panic disorder, but there is a need for controlled studies and investigation of the relative contribution of its various components. 2008 John Wiley & Sons, Ltd.

Chest injuries related to surfing.

PubMed

Sano, Atsushi; Yotsumoto, Takuma

2015-09-01

Surfing is a popular sport in coastal areas, which can be associated with chest injuries. Between 2008 and 2013, 6 patients were referred to our hospital with chest injuries sustained during surfing. Clinical data were collected from their medical records and analyzed retrospectively. Patient age ranged from 35 to 52 years. Five of the 6 patients were male. Four patients were injured in August, and the other two were injured in September and October. Rib fractures were observed in 3 of the 6 patients. The other 3 patients were diagnosed with chest contusions only. Hemothorax occurred in one patient. No lacerations were observed in any of the 6 patients. Chest injuries associated with surfing are usually blunt chest injuries; however, they may occasionally be life-threatening. © The Author(s) 2015.

Identification of a novel deletion in SURF1 gene: Heterogeneity in Leigh syndrome with COX deficiency.

PubMed

Ribeiro, Carolina; do Carmo Macário, Maria; Viegas, Ana Teresa; Pratas, João; Santos, Maria João; Simões, Marta; Mendes, Cândida; Bacalhau, Mafalda; Garcia, Paula; Diogo, Luísa; Grazina, Manuela

2016-11-01

Leigh syndrome (LS) is a rare, progressive neurodegenerative mitochondrial disorder of infancy. It is a genetically heterogeneous disease. The mutations in SURF1 gene are the most frequently known cause. Here two cases of LS likely caused by SURF1 gene variants are reported: a 39-year-old male patient with a novel homozygous deletion (c.-11_13del), and a case of a 6-year-old boy with the same deletion and a nonsense mutation (c.868dupT), both in heterozygosity. Blue native PAGE showed absence of assembled complex IV. This is the first report of a variant that may abolish the SURF1 gene initiation codon in two LS patients. Copyright © 2016 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

Car surfing: an uncommon cause of traumatic injury.

PubMed

Peterson, T; Timberlake, G; Yeager, A; Jadali, M; Royer, K

1999-02-01

Car surfing is an infrequent cause of traumatic injuries treated by emergency physicians. This very dangerous activity can result in serious injury or death. We report 5 cases of injuries caused by car surfing seen at our hospital during 1996 and 1997. All involved head injuries after a fall from a moving motor vehicle. There were 3 male and 2 female patients, and 3 cases were fatal. Health care providers should be aware of this type of injury and support efforts to prevent it.

50 CFR 648.76 - Maine mahogany quahog zone.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.76 Maine mahogany quahog zone. (a) Landing requirements... Advisory Panel shall make recommendations, through the Surf Clam and Ocean Quahog Committee of the Council...

Polyelectrolyte-Surfactant Complexes: A New Class of Organogelators

NASA Astrophysics Data System (ADS)

Cavicchi, Kevin; Liu, Yuqing; Guzman, Gustavo

2011-03-01

Polyelectrolyte-surfactant complexes (PE-SURFs) are a class of polymers generated by neutralizing a polyelectrolyte with an oppositely charged surfactant. It has been found that PE-SURFs composed of polystyrene sulfonate and long chain alkyl dimethyl amines act as good organogelators for a range of hydrophobic, organic solvents. Thermo-reversible organogels are formed by heating and cooling PE-SURF/solvent solutions. The gel transition temperature is influenced by the degree of polymerization, the length of the alkyl side-chain, the solubility parameter of the solvent, and the concentration of the gelator. Freeze-drying and scanning electron microscopy characterization of the resultant xerogels shows the formation of rod- and plate-like network morphologies depending on the system parameters. This behavior is consistent with gelation driven by the self-assembly of the amphiphilic PE-SURFs into micellar networks.

Shock waves raised by explosions in space as sources of ultra-high-energy cosmic rays

NASA Astrophysics Data System (ADS)

Kichigin, Gennadiy

2015-03-01

The paper discusses the possibility of particle acceleration up to ultrahigh energies in the relativistic waves generated by various explosive processes in the interstellar medium. We propose to use the surfatron mechanism of acceleration (surfing) of charged particles trapped in the front of relativistic waves as a generator of high-energy cosmic rays (CRs). Conditions under which surfing in these waves can be made are studied thoroughly. Ultra-high-energy CRs (up to 10^20 eV) are shown to be obtained due to the surfing in the relativistic plane and spherical waves. Surfing is supposed to take place in nonlinear Langmuir waves excited by powerful electromagnetic radiation or relativistic beams of charged particles, as well as in strong shock waves generated by relativistic jets or spherical formations that expand fast (fireballs).

Gradient changes in structural condition of the B2 phase of NiTi surface layers after electron-beam treatments

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

Meisner, Ludmila L., E-mail: llm@ispms.tsc.ru, E-mail: egu@ispms.tsc.ru; Gudimova, Ekaterina Yu., E-mail: llm@ispms.tsc.ru, E-mail: egu@ispms.tsc.ru; Ostapenko, Marina G., E-mail: artifact@ispms.tsc.ru

2014-11-14

Structural conditions of the B2 phase of the Ti{sub 49.5}Ni{sub 50.5} alloy surface layers before and after electron-beam treatments (pulse duration τ = 150 μs, number of pulses n = 5, beam energy density E ≤ 20 J/cm{sup 2}) were studied by X-ray diffraction analysis. Analysis of the X-ray patterns demonstrates that surface layers modified by electron beam treatment contain phase with B2{sup surf} structure. It is revealed that the lattice parameter of the B2{sup surf} phase in the surface (modified) layer is also higher than the lattice parameter of the B2 phase in the underlying layer (a{sub B2} = 3.0159±0.0005). Themore » values of lattice parameter of phase B2{sup surf} amounted a{sub B2}{sup surf} = 3.0316±0.0005 Å and a{sub B2}{sup surf} = 3.0252±0.0005 Å, for the specimens after electron-beam treatment at E{sub 1} = 15 J/cm{sup 2} and E{sub 2} = 20 J/cm{sup 2}, respectively. Inflated lattice parameters a{sub B2}{sup surf} are associated with changes in the chemical composition and the presence of residual stresses in the surface region of the samples after electron-beam treatments.« less

Effects of image charges, interfacial charge discreteness, and surface roughness on the zeta potential of spherical electric double layers.

PubMed

Gan, Zecheng; Xing, Xiangjun; Xu, Zhenli

2012-07-21

We investigate the effects of image charges, interfacial charge discreteness, and surface roughness on spherical electric double layer structures in electrolyte solutions with divalent counterions in the setting of the primitive model. By using Monte Carlo simulations and the image charge method, the zeta potential profile and the integrated charge distribution function are computed for varying surface charge strengths and salt concentrations. Systematic comparisons were carried out between three distinct models for interfacial charges: (1) SURF1 with uniform surface charges, (2) SURF2 with discrete point charges on the interface, and (3) SURF3 with discrete interfacial charges and finite excluded volume. By comparing the integrated charge distribution function and the zeta potential profile, we argue that the potential at the distance of one ion diameter from the macroion surface is a suitable location to define the zeta potential. In SURF2 model, we find that image charge effects strongly enhance charge inversion for monovalent interfacial charges, and strongly suppress charge inversion for multivalent interfacial charges. For SURF3, the image charge effect becomes much smaller. Finally, with image charges in action, we find that excluded volumes (in SURF3) suppress charge inversion for monovalent interfacial charges and enhance charge inversion for multivalent interfacial charges. Overall, our results demonstrate that all these aspects, i.e., image charges, interfacial charge discreteness, their excluding volumes, have significant impacts on zeta potentials of electric double layers.

Image segmentation-based robust feature extraction for color image watermarking

NASA Astrophysics Data System (ADS)

Li, Mianjie; Deng, Zeyu; Yuan, Xiaochen

2018-04-01

This paper proposes a local digital image watermarking method based on Robust Feature Extraction. The segmentation is achieved by Simple Linear Iterative Clustering (SLIC) based on which an Image Segmentation-based Robust Feature Extraction (ISRFE) method is proposed for feature extraction. Our method can adaptively extract feature regions from the blocks segmented by SLIC. This novel method can extract the most robust feature region in every segmented image. Each feature region is decomposed into low-frequency domain and high-frequency domain by Discrete Cosine Transform (DCT). Watermark images are then embedded into the coefficients in the low-frequency domain. The Distortion-Compensated Dither Modulation (DC-DM) algorithm is chosen as the quantization method for embedding. The experimental results indicate that the method has good performance under various attacks. Furthermore, the proposed method can obtain a trade-off between high robustness and good image quality.

Deleterious mutations can surf to high densities on the wave front of an expanding population.

PubMed

Travis, Justin M J; Münkemüller, Tamara; Burton, Olivia J; Best, Alex; Dytham, Calvin; Johst, Karin

2007-10-01

There is an increasing recognition that evolutionary processes play a key role in determining the dynamics of range expansion. Recent work demonstrates that neutral mutations arising near the edge of a range expansion sometimes surf on the expanding front leading them rather than that leads to reach much greater spatial distribution and frequency than expected in stationary populations. Here, we extend this work and examine the surfing behavior of nonneutral mutations. Using an individual-based coupled-map lattice model, we confirm that, regardless of its fitness effects, the probability of survival of a new mutation depends strongly upon where it arises in relation to the expanding wave front. We demonstrate that the surfing effect can lead to deleterious mutations reaching high densities at an expanding front, even when they have substantial negative effects on fitness. Additionally, we highlight that this surfing phenomenon can occur for mutations that impact reproductive rate (i.e., number of offspring produced) as well as mutations that modify juvenile competitive ability. We suggest that these effects are likely to have important consequences for rates of spread and the evolution of spatially expanding populations.

Surfing-related ocular injuries.

PubMed

Kim, J W; McDonald, H R; Rubsamen, P E; Luttrull, J K; Drouilhet, J H; Frambach, D A; Boyer, D S; Lambrou, F H; Hendrick, A; Weiss, J N; Engstrom, R E; Ing, M

1998-01-01

This report evaluates the clinical characteristics of surfing-related ocular trauma to learn the nature of such injuries and propose possible preventive measures. The authors reviewed 11 cases of surfing-related eye injuries caused by direct trauma from the surfboard, studying their mechanism of injury, the associated ocular complications, and the anatomic and visual outcomes of surgical repair. Surfing-related ocular injuries occurred exclusively in young males (mean age, 24.8 years; range, 14-37 years). The mechanism of injury most frequently responsible was impact with the sharp nose of the surfboard following a fall. Serious posterior segment complications were observed in all 11 patients, with nine patients suffering ruptured globes. Despite immediate medical attention, five patients did not recover ambulatory levels of visual acuity (>5/200). Surfing-related ocular trauma presenting to the retinal specialist typically leaves the patient with a permanent visual disability. Important factors contributing to these high-velocity injuries include the sharply pointed nose of the surfboard and the leash keeping the surfer in close proximity to the board following a fall. A simple modification in surfboard design such as blunting the sharp nose of the surfboard, or appropriate protective guards fitted over the surfboard nose, should lessen the severity of such injuries.

Seabed Gradient Controlling Onshore Transport Rates of Surf Sand during Beach Retreat by Sea Level Rise

NASA Astrophysics Data System (ADS)

Lee, Hee Jun; Yi, Hi-Il

2018-03-01

A simple relationship is proposed for the onshore transport rates of surf-zone sand to evaluate the beach retreat caused by sea level rise. It suggests that the preservation potential of surf sand is proportional inversely to the seabed gradient during beach retreat. According to this relationship, the erosional remnants of surf sand would be more readily developed on a gentler shelf collectively as transgressive sand sheets. This finding may explain the previous studies regarding the Korean shelves that proposed that the Holocene transgressive sand sheets (HTSS) occur not in the steep eastern shelf but in the gentle western shelf. In line with such presence/absence of the HTSS are the results from some coastal seismic profiles obtained in the present study. The profiles indicate that sand deposits are restricted within the nearshore in the eastern coast, whereas they are persistently traceable to the offshore HTSS in the western coast. Tide is proven to have a negligible influence on the total duration of surf-zone processes. This study may be useful in predicting the consequences of the beach retreat that takes place worldwide as sea levels rise as a result of global warming.

The incidence of inflatable rescue boat injuries in Queensland surf lifesavers.

PubMed

Bigby, K J; McClure, R J; Green, A C

2000-05-15

To estimate the current incidence of serious injuries in Queensland surf lifesavers related to inflatable rescue boat (IRB) use, and to describe the nature of the injuries. Descriptive study. The 3050 members of Queensland's 57 surf life saving clubs who drove or crewed an IRB in Queensland between July 1997 and June 1998. Incidence of serious IRB-related injuries that resulted in claims for workers compensation in 1997-1998, and type and anatomical location of injury. Thirty-six IRB-related injuries were lodged with WorkCover Queensland by surf lifesavers during 1997-1998, giving an estimated crude incidence of 1.2%. Sixty-one per cent of injuries affected the right side of the body; two-thirds of these involved the knee, leg and ankle. IRB injuries occurred most often during patrol duty (39% of cases) and it was usually the crewperson (86% of cases) who was injured. Fracture and fracture-dislocations constituted a third of the injuries, with 75% occurring in the right leg and ankle. Despite the known incomplete reporting of these injuries, our findings suggest that IRB-related injury caused substantial morbidity among volunteer surf lifesavers. The pattern of injuries suggests biomechanically preventable causes.

An efficient direct method for image registration of flat objects

NASA Astrophysics Data System (ADS)

Nikolaev, Dmitry; Tihonkih, Dmitrii; Makovetskii, Artyom; Voronin, Sergei

2017-09-01

Image alignment of rigid surfaces is a rapidly developing area of research and has many practical applications. Alignment methods can be roughly divided into two types: feature-based methods and direct methods. Known SURF and SIFT algorithms are examples of the feature-based methods. Direct methods refer to those that exploit the pixel intensities without resorting to image features and image-based deformations are general direct method to align images of deformable objects in 3D space. Nevertheless, it is not good for the registration of images of 3D rigid objects since the underlying structure cannot be directly evaluated. In the article, we propose a model that is suitable for image alignment of rigid flat objects under various illumination models. The brightness consistency assumptions used for reconstruction of optimal geometrical transformation. Computer simulation results are provided to illustrate the performance of the proposed algorithm for computing of an accordance between pixels of two images.

Radar signal return from near-shore surface and shallow subsurface features, Darien Province, Panama

NASA Technical Reports Server (NTRS)

Hanson, B. C.; Dellwig, L. F.

1973-01-01

The AN/APQ-97 radar imagery over eastern Panama is analyzed. The imagery was directed toward extraction of geologic and engineering data and the establishment of operational parameters. Subsequent investigations emphasized landform identification and vegetation distribution. The parameters affecting the observed return signal strength from such features are considered. Near-shore ocean phenomena were analyzed. Tidal zone features such as mud flats and reefs were identified in the near range, but were not detectable in the far range. Surface roughness dictated the nature of reflected energy (specular or diffuse). In surf zones, changes in wave train orientation relative to look direction, the slope of the surface, and the physical character of the wave must be considered. It is concluded that the establishment of the areal extent of the tidal flats, distributary channels, and reefs is practical only in the near to intermediate range under minimal low tide conditions.

SU-F-R-31: Identification of Robust Normal Lung CT Texture Features for the Prediction of Radiation-Induced Lung Disease

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

Choi, W; Riyahi, S; Lu, W

Purpose: Normal lung CT texture features have been used for the prediction of radiation-induced lung disease (radiation pneumonitis and radiation fibrosis). For these features to be clinically useful, they need to be relatively invariant (robust) to tumor size and not correlated with normal lung volume. Methods: The free-breathing CTs of 14 lung SBRT patients were studied. Different sizes of GTVs were simulated with spheres placed at the upper lobe and lower lobe respectively in the normal lung (contralateral to tumor). 27 texture features (9 from intensity histogram, 8 from grey-level co-occurrence matrix [GLCM] and 10 from grey-level run-length matrix [GLRM])more » were extracted from [normal lung-GTV]. To measure the variability of a feature F, the relative difference D=|Fref -Fsim|/Fref*100% was calculated, where Fref was for the entire normal lung and Fsim was for [normal lung-GTV]. A feature was considered as robust if the largest non-outlier (Q3+1.5*IQR) D was less than 5%, and considered as not correlated with normal lung volume when their Pearson correlation was lower than 0.50. Results: Only 11 features were robust. All first-order intensity-histogram features (mean, max, etc.) were robust, while most higher-order features (skewness, kurtosis, etc.) were unrobust. Only two of the GLCM and four of the GLRM features were robust. Larger GTV resulted greater feature variation, this was particularly true for unrobust features. All robust features were not correlated with normal lung volume while three unrobust features showed high correlation. Excessive variations were observed in two low grey-level run features and were later identified to be from one patient with local lung diseases (atelectasis) in the normal lung. There was no dependence on GTV location. Conclusion: We identified 11 robust normal lung CT texture features that can be further examined for the prediction of radiation-induced lung disease. Interestingly, low grey-level run features identified normal lung diseases. This work was supported in part by the National Cancer Institute Grants R01CA172638.« less

Heart Rate Responses of High School Students Participating in Surfing Physical Education.

PubMed

Bravo, Michelle M; Cummins, Kevin M; Nessler, Jeff A; Newcomer, Sean C

2016-06-01

Despite the nation's rising epidemic of childhood obesity and diabetes, schools struggle to promote physical activities that help reduce risks for cardiovascular disease. Emerging data suggest that adopting novel activities into physical education (PE) curriculum may serve as an effective strategy for increasing physical activity in children. The purpose of this investigation was to characterize activity in the water and heart rates (HRs) of high school students participating in surf PE courses. Twenty-four male (n = 20) and female (n = 4) high school students (mean age = 16.7 ± 1.0 years) who were enrolled in surf PE courses at 2 high schools participated in this investigation. Daily measurements of surfing durations, average HR, and maximum HR were made on the students with HR monitors (PolarFT1) over an 8-week period. In addition, HR and activity in the water was evaluated during a single session in a subset of students (n = 11) using a HR monitor (PolarRCX5) and a video camera (Canon HD). Activity and HR were synchronized and evaluated in 5-second intervals during data analyses. The average duration that PE students participated in surfing during class was 61.7 ± 1.0 minutes. Stationary, paddling, wave riding, and miscellaneous activities comprised 42.7 ± 9.5, 36.7 ± 7.9, 2.9 ± 1.4, and 17.8 ± 11.4 percent of the surf session, respectively. The average and maximum HRs during these activities were 131.1 ± 0.9 and 177.2 ± 1.0 b·min, respectively. These data suggest that high school students participating in surf PE attained HRs and durations that are consistent with recommendations with cardiovascular fitness and health. In the future, PE programs should consider incorporating other action sports into their curriculum to enhance cardiovascular health.

Car surfing: an underreported mechanism of serious injury in children and adolescents.

PubMed

Geiger, J D; Newsted, J; Drongowski, R A; Lelli, J L

2001-01-01

Car surfing, in which participants stand on top of a moving vehicle as though it were a surfboard, has been reported as a cause of traumatic injury in only 5 cases in the literature. Over the last 8 years, however, the authors have treated 26 children, primarily adolescents, for injuries resulting from car surfing. This report describes the injuries and outcomes of this potentially underreported mechanism of injury. Medical records of 26 patients treated for car surfing injuries between 1991 and 1999 were reviewed. Demographics, hospital course, and type and severity of injuries were analyzed. Eighteen boys (69%) and 8 girls (31%) with an average age of 15.7+/-3.4 years (range, 6 to 22) have presented with injuries related to car surfing. All patients had fallen from the hood, roof, or trunk of a moving motor vehicle, the majority falling from the hood (n = 13; 50%). Injury severity was evaluated using the Injury Severity Scores (ISS; 12.4+/-6.5), Revised Trauma Score (RTS; 7.5+/- 1.1) and Glasgow Coma Score (GCS; 13.5+/-3.2). Injury severity was equivalent between boys and girls (P>.05). Central nervous system injuries predominated, with closed head injuries occurring in 22 (85%) and loss of consciousness in 10 (39%). Skull fractures occurred in 11 (42%) and intracranial bleeding in 9 (35%). Long-term cognitive rehabilitation was necessary in 22 (85%) patients. Three patients (12%) had spinal column fractures, with 2 (8%) suffering permanent paralysis. Two extremity (8%) and 3 (11.7%) pelvic fractures occurred. Most patients (73%) suffered significant skin and soft tissue injuries. Two patients (8%) presented with solid visceral injuries, and 1 child died. Car surfing is an extremely high-risk behavior in children and adolescents that leads to significant morbidity, long-term disability, and is potentially fatal. The incidence of car surfing may be greater than has been reported previously; therefore, prevention programs aimed at discouraging this high-risk behavior in children and adolescents should be considered.

50 CFR 648.77 - Framework adjustments to management measures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Management Measures for the Atlantic Surf Clam and Ocean Quahog Fisheries § 648.77 Framework adjustments to... add or adjust management measures within the Atlantic Surf Clam and Ocean Quahog FMP if it finds that...

The State of stress in the Sanford Underground Research Facility (SURF) in Lead South Dakota

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

Lee, Moo Y.

2016-10-01

As a part of the U.S. Department of Energy (DOE) SubTER (Subsurface Technology and Engineering Research, Development and Demonstration) initiative, University of Wisconsin- Madison, Sandia National Laboratories, and Lawrence Berkeley National Laboratory conducted the Permeability (k) and Induced Seismicity Management for Energy Technologies (kISMET) project. The objectives of the project are to define the in situ status of stress in the Sanford Underground Research Facility (SURF) in Lead, South Dakota and to establish the relations between in situ stress and induced fracture through hydraulically stimulating the fracture. (SURF) in Lead, South Dakota. In situ tests are conducted in a 7.6more » cm diameter and 100 long vertical borehole located in the 4850 Level West Access Drift near Davies Campus of SURF (Figure 1). The borehole is located in the zone of Precambrian Metamorphic Schist.« less

The Sanford Underground Research Facility at Homestake (SURF)

DOE PAGES

Lesko, K. T.

2015-03-24

The former Homestake gold mine in Lead, South Dakota is being transformed into a dedicated laboratory to pursue underground research in rare-process physics, as well as offering research opportunities in other disciplines. A key component of the Sanford Underground Research Facility (SURF) is the Davis Campus, which is in operation at the 4850-foot level (4300 m.w.e) and currently hosts three projects: the LUX dark matter experiment, the Majorana Demonstrator neutrinoless double-beta decay experiment and the Berkeley and CUBED low-background counters. Plans for possible future experiments at SURF are well underway and include long baseline neutrino oscillation experiments, future dark mattermore » experiments as well as nuclear astrophysics accelerators. Facility upgrades to accommodate some of these future projects have already started. SURF is a dedicated facility with significant expansion capability. These plans include a Generation-2 Dark Matter experiment and the US flagship neutrino experiment, LBNE.« less

Robustness of radiomic breast features of benign lesions and luminal A cancers across MR magnet strengths

NASA Astrophysics Data System (ADS)

Whitney, Heather M.; Drukker, Karen; Edwards, Alexandra; Papaioannou, John; Giger, Maryellen L.

2018-02-01

Radiomics features extracted from breast lesion images have shown potential in diagnosis and prognosis of breast cancer. As clinical institutions transition from 1.5 T to 3.0 T magnetic resonance imaging (MRI), it is helpful to identify robust features across these field strengths. In this study, dynamic contrast-enhanced MR images were acquired retrospectively under IRB/HIPAA compliance, yielding 738 cases: 241 and 124 benign lesions imaged at 1.5 T and 3.0 T and 231 and 142 luminal A cancers imaged at 1.5 T and 3.0 T, respectively. Lesions were segmented using a fuzzy C-means method. Extracted radiomic values for each group of lesions by cancer status and field strength of acquisition were compared using a Kolmogorov-Smirnov test for the null hypothesis that two groups being compared came from the same distribution, with p-values being corrected for multiple comparisons by the Holm-Bonferroni method. Two shape features, one texture feature, and three enhancement variance kinetics features were found to be potentially robust. All potentially robust features had areas under the receiver operating characteristic curve (AUC) statistically greater than 0.5 in the task of distinguishing between lesion types (range of means 0.57-0.78). The significant difference in voxel size between field strength of acquisition limits the ability to affirm more features as robust or not robust according to field strength alone, and inhomogeneities in static field strength and radiofrequency field could also have affected the assessment of kinetic curve features as robust or not. Vendor-specific image scaling could have also been a factor. These findings will contribute to the development of radiomic signatures that use features identified as robust across field strength.

Car surfing: case studies of a growing dangerous phenomenon.

PubMed

Clark, Steven; Mangram, Alicia; Dunn, Ernest

2008-03-01

Car surfing is a dangerous new pastime for American youth. Car surfing is an activity that is defined as standing (or lying) on a vehicle while it is being driven. This activity frequently results in severe injuries that often require significant surgical intervention. Despite its destructive nature, however, there are many Internet sites that encourage this behavior and view it as amusing. As a result, car surfing is becoming increasingly popular. We conducted a retrospective chart review of all patients injured as a result of car surfing over the last 4 years at our Urban Level II trauma center. Data collected included Injury Severity Score (ISS), Revised Trauma Score (RTS), age, gender, injury pattern, surgical intervention, and length of stay. Eight car surfers were identified. The average age was 17. The average Revised Trauma Score was 6.8 with an average Injury Severity Score of 16.9. Five patients were admitted to the intensive care unit. Four of these five patients needed to be intubated for ventilatory support. Five of the eight patients had significant intracranial injuries. Two patients had epidural hematomas that required evacuation. Two other patients had subdural hematomas that were treated nonoperatively, and one patient had a subarachnoid hemorrhage that was also treated nonoperatively. Four of the eight patients required surgical intervention. There were no deaths in this study. Car surfing leads to severe injuries that can result in significant morbidity. American youth have access to Internet sites that project this activity as an acceptable behavior. Five of our eight patients had a significant intracranial injury. Trauma surgeons need to be more aware of this injury phenomenon.

The ssWavelets package

Treesearch

Jeffrey H. Gove

2017-01-01

This package adds several classes, generics and associated methods as well as a few various functions to help with wavelet decomposition of sampling surfaces generated using sampSurf. As such, it can be thought of as an extension to sampSurf for wavelet analysis.

Surfer's myelopathy: case report and review.

PubMed

Karabegovic, Amna; Strachan-Jackman, Shirley; Carr, David

2011-09-01

Nontraumatic spinal cord injury from surfing is a new entity first described in 2004 and likely of ischemic etiology. We report the case of a 25-year-old man who presented to the emergency department with a 2-week history of lower extremity weakness after surfing in Indonesia. The patient reported developing low back pain, lower extremity weakness, sensory changes, and urinary retention shortly after his first surfing lesson. The patient was subsequently diagnosed with surfer's myelopathy. The purpose of this report is to review the clinical presentation, etiology, risk factors, and management of this increasingly described entity.

Women's Recreational Surfing: A Patronising Experience

ERIC Educational Resources Information Center

Olive, Rebecca; McCuaig, Louise; Phillips, Murray G.

2015-01-01

Research analysing the operation of power within sport and physical activity has exposed the marginalisation and exclusion of women's sport in explicit and institutionalised ways. However, for women in recreational and alternative physical activities like surfing, sporting experiences lie outside institutionalised structures, thus requiring…

Genome surfing as driver of microbial genomic diversity

USDA-ARS?s Scientific Manuscript database

Historical changes in population size, such as those caused by demographic range expansions, can produce nonadaptive changes in genomic diversity through mechanisms such as gene surfing. We propose that demographic range expansion of a microbial population capable of horizontal gene exchange can res...

77 FR 43236 - Proposed Information Collection; Comment Request; SURF Program Student Applicant Information

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-24

... DEPARTMENT OF COMMERCE National Institute of Standards and Technology Proposed Information Collection; Comment Request; SURF Program Student Applicant Information AGENCY: National Institute of Standards and Technology (NIST), Commerce. ACTION: Notice. SUMMARY: The Department of Commerce, as part of...

WATERSHED INFORMATION - SURF YOUR WATERSHED

EPA Science Inventory

Surf Your Watershed is both a database of urls to world wide web pages associated with the watershed approach of environmental management and also data sets of relevant environmental information that can be queried. It is designed for citizens and decision makers across the count...

SU-E-J-131: Augmenting Atlas-Based Segmentation by Incorporating Image Features Proximal to the Atlas Contours

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

Li, Dengwang; Liu, Li; Kapp, Daniel S.

2015-06-15

Purpose: For facilitating the current automatic segmentation, in this work we propose a narrow-shell strategy to enhance the information of each contour in the library and to improve the accuracy of the exiting atlas-based approach. Methods: In setting up an atlas-based library, we include not only the coordinates of contour points, but also the image features adjacent to the contour. 139 planning CT scans with normal appearing livers obtained during their radiotherapy treatment planning were used to construct the library. The CT images within the library were registered each other using affine registration. A nonlinear narrow shell with the regionalmore » thickness determined by the distance between two vertices alongside the contour. The narrow shell was automatically constructed both inside and outside of the liver contours. The common image features within narrow shell between a new case and a library case were first selected by a Speed-up Robust Features (SURF) strategy. A deformable registration was then performed using a thin plate splines (TPS) technique. The contour associated with the library case was propagated automatically onto the images of the new patient by exploiting the deformation field vectors. The liver contour was finally obtained by employing level set based energy function within the narrow shell. The performance of the proposed method was evaluated by comparing quantitatively the auto-segmentation results with that delineated by a physician. Results: Application of the technique to 30 liver cases suggested that the technique was capable of reliably segment organs such as the liver with little human intervention. Compared with the manual segmentation results by a physician, the average and discrepancies of the volumetric overlap percentage (VOP) was found to be 92.43%+2.14%. Conclusion: Incorporation of image features into the library contours improves the currently available atlas-based auto-contouring techniques and provides a clinically practical solution for auto-segmentation. This work is supported by NIH/NIBIB (1R01-EB016777), National Natural Science Foundation of China (No.61471226 and No.61201441), Research funding from Shandong Province (No.BS2012DX038 and No.J12LN23), and Research funding from Jinan City (No.201401221 and No.20120109)« less

Factors influencing fish and macrocrustacean communities in the surf zone of sandy beaches in Belgium: temporal variation

NASA Astrophysics Data System (ADS)

Beyst, Bregje; Hostens, Kris; Mees, Jan

2001-12-01

Monthly samples were taken in the surf zone of sandy beaches along the Belgian coast from May 1996 until July 1997 at four selected stations. Temporal patterns of the macrocrustacean and fish species residing the surf zone were investigated, as well as the abiotic variables structuring the community. In total 34 species were recorded belonging to caridean shrimps (3), anomuran and brachyuran crabs (5), cephalopods (2) and fish (24). The brown shrimp Crangon crangon dominated almost all samples (>80%). Total densities often exceeded 400 ind per 100 m2, and if C. crangon was excluded 10 ind per 100 m2. Notwithstanding the harsh hydrodynamic conditions, the surf zone of Belgian sandy beaches is used intensively by a number of epibenthic macro-crustaceans and demersal fish species. Seven resident and ten migrant species were identified. As mainly juvenile fishes were present, the surf zone of the Belgian sandy beaches may act as a nursery for longer (e.g. plaice Pleuronectes platessa) or shorter (e.g. brill Scophthalmus rhombus) periods. However, its nursery function should be studied in more detail, since the highly dynamic circumstances and more specifically wave height and wind speed may be important structuring factors for the epibenthic communities. The surf zone of Belgian sandy beaches also seems to function as a transient area to other nurseries (e.g. bass Dicentrarchus labrax) or between a nursery and the true marine environment (e.g. dab Limanda limanda). Temporal variation in community structure was greatly masked by spatial differences between sites. Although variables such as salinity and hydrodynamic factors may have influenced the data, clear temperature-related, seasonal patterns occur. Most likely, extreme winter conditions and subsequent migration of organisms to deeper waters caused a decline in winter in both density and diversity.

Observations of storm morphodynamics using Coastal Lidar and Radar Imaging System (CLARIS): Importance of wave refraction and dissipation over complex surf-zone morphology at a shoreline erosional hotspot

NASA Astrophysics Data System (ADS)

Brodie, Katherine L.

Elevated water levels and large waves during storms cause beach erosion, overwash, and coastal flooding, particularly along barrier island coastlines. While predictions of storm tracks have greatly improved over the last decade, predictions of maximum water levels and variations in the extent of damage along a coastline need improvement. In particular, physics based models still cannot explain why some regions along a relatively straight coastline may experience significant erosion and overwash during a storm, while nearby locations remain seemingly unchanged. Correct predictions of both the timing of erosion and variations in the magnitude of erosion along the coast will be useful to both emergency managers and homeowners preparing for an approaching storm. Unfortunately, research on the impact of a storm to the beach has mainly been derived from "pre" and "post" storm surveys of beach topography and nearshore bathymetry during calm conditions. This has created a lack of data during storms from which to ground-truth model predictions and test hypotheses that explain variations in erosion along a coastline. We have developed Coastal Lidar and Radar Imaging System (CLARIS), a mobile system that combines a terrestrial scanning laser and an X-band marine radar system using precise motion and location information. CLARIS can operate during storms, measuring beach topography, nearshore bathymetry (from radar-derived wave speed measurements), surf-zone wave parameters, and maximum water levels remotely. In this dissertation, we present details on the development, design, and testing of CLARIS and then use CLARIS to observe a 10 km section of coastline in Kitty Hawk and Kill Devil Hills on the Outer Banks of North Carolina every 12 hours during a Nor'Easter (peak wave height in 8 m of water depth = 3.4 m). High decadal rates of shoreline change as well as heightened erosion during storms have previously been documented to occur within the field site. In addition, complex bathymetric features that traverse the surf-zone into the nearshore are present along the southern six kilometers of the field site. In addition to the CLARIS observations, we model wave propagation over the complex nearshore bathymetry for the same storm event. Data reveal that the complex nearshore bathymetry is mirrored by kilometer scale undulations in the shoreline, and that both morphologies persist during storms, contrary to common observations of shoreline and surf-zone linearization by large storm waves. We hypothesize that wave refraction over the complex nearshore bathymetry forces flow patterns which may enhance or stabilize the shoreline and surf-zone morphology during storms. In addition, our semi-daily surveys of the beach indicate that spatial and temporal patterns of erosion are strongly correlated to the steepness of the waves. Along more than half the study site, fifty percent or more of the erosion that occurred during the first 12 hours of the storm was recovered within 24 hours of the peak of the storm as waves remained large (>2.5 m), but transitioned to long period swell. In addition, spatial variations in the amount of beach volume change during the building portion of the storm were strongly correlated with observed wave dissipation within the inner surf zone, as opposed to predicted inundation elevations or alongshore variations in wave height.

The ConSurf-DB: pre-calculated evolutionary conservation profiles of protein structures.

PubMed

Goldenberg, Ofir; Erez, Elana; Nimrod, Guy; Ben-Tal, Nir

2009-01-01

ConSurf-DB is a repository for evolutionary conservation analysis of the proteins of known structures in the Protein Data Bank (PDB). Sequence homologues of each of the PDB entries were collected and aligned using standard methods. The evolutionary conservation of each amino acid position in the alignment was calculated using the Rate4Site algorithm, implemented in the ConSurf web server. The algorithm takes into account the phylogenetic relations between the aligned proteins and the stochastic nature of the evolutionary process explicitly. Rate4Site assigns a conservation level for each position in the multiple sequence alignment using an empirical Bayesian inference. Visual inspection of the conservation patterns on the 3D structure often enables the identification of key residues that comprise the functionally important regions of the protein. The repository is updated with the latest PDB entries on a monthly basis and will be rebuilt annually. ConSurf-DB is available online at http://consurfdb.tau.ac.il/

The ConSurf-DB: pre-calculated evolutionary conservation profiles of protein structures

PubMed Central

Goldenberg, Ofir; Erez, Elana; Nimrod, Guy; Ben-Tal, Nir

2009-01-01

ConSurf-DB is a repository for evolutionary conservation analysis of the proteins of known structures in the Protein Data Bank (PDB). Sequence homologues of each of the PDB entries were collected and aligned using standard methods. The evolutionary conservation of each amino acid position in the alignment was calculated using the Rate4Site algorithm, implemented in the ConSurf web server. The algorithm takes into account the phylogenetic relations between the aligned proteins and the stochastic nature of the evolutionary process explicitly. Rate4Site assigns a conservation level for each position in the multiple sequence alignment using an empirical Bayesian inference. Visual inspection of the conservation patterns on the 3D structure often enables the identification of key residues that comprise the functionally important regions of the protein. The repository is updated with the latest PDB entries on a monthly basis and will be rebuilt annually. ConSurf-DB is available online at http://consurfdb.tau.ac.il/ PMID:18971256

Drones at the Beach - Surf Zone Monitoring Using Rotary Wing Unmanned Aerial Vehicles

NASA Astrophysics Data System (ADS)

Rynne, P.; Brouwer, R.; de Schipper, M. A.; Graham, F.; Reniers, A.; MacMahan, J. H.

2014-12-01

We investigate the potential of rotary wing Unmanned Aerial Vehicles (UAVs) to monitor the surf zone. In recent years, the arrival of lightweight, high-capacity batteries, low-power electronics and compact high-definition cameras has driven the development of commercially available UAVs for hobbyists. Moreover, the low operation costs have increased their potential for scientific research as these UAVs are extremely flexible surveying platforms. The UAVs can fly for ~12 min with a mean loiter radius of 1 - 3.5 m and a mean loiter error of 0.75 - 4.5 m, depending on the environmental conditions, flying style, battery type and vehicle type. Our experiments using multiple, alternating UAVs show that it is possible to have near continuous imagery data with similar Fields Of View. The images obtained from the UAVs (Fig. 1a), and in combination with surveyed Ground Control Points (GCPs) (Fig. 1b, red squares and white circles), can be geo-rectified (Fig. 1c) to pixel resolution between 0.01 - 1 m and a reprojection error, i.e. the difference between the surveyed GPS location of a GCP and the location of the GCP obtained from the geo-rectified image, of O(1 m). These geo-rectified images provide data on a variety of coastal aspects, such as beach width (Wb(x,t)), surf zone width (Wsf(x,t)), wave breaking location (rectangle B), beach usage (circle C) and location of dune vegegation (rectangle D), amongst others. Additionally, the possibility to have consecutive, high frequency (up to 2 Hz) rectified images makes the UAVs a great data instrument for spatially and temporally variable systems, such as the surf zone. Our first observations with the UAVs reveal the potential to quickly obtain surf zone and beach characteristics in response to storms or for day to day beach information, as well as the scientific pursuits of surf zone kinematics on different spatial and temporal scales, and dispersion and advection estimates of pollutants/dye. A selection of findings from several field experiments and using multiple optical instruments will be showed at the meeting, discussing the new possibilities rotary wing UAVs can offer for surf zone research.

Comparing Four Instructional Techniques for Promoting Robust Knowledge

ERIC Educational Resources Information Center

Richey, J. Elizabeth; Nokes-Malach, Timothy J.

2015-01-01

Robust knowledge serves as a common instructional target in academic settings. Past research identifying characteristics of experts' knowledge across many domains can help clarify the features of robust knowledge as well as ways of assessing it. We review the expertise literature and identify three key features of robust knowledge (deep,…

Surfing Global Change: Negotiating Sustainable Solutions

ERIC Educational Resources Information Center

Ahamer, Gilbert

2006-01-01

SURFING GLOBAL CHANGE (SGC) serves as a procedural shell for attaining sustainable solutions for any interdisciplinary issue and is intended for use in advanced university courses. The participants' activities evolve through five levels from individual argumentation to molding one's own views for the "common good." The paradigm of…

SURF's Up: An Outline of an Innovative Framework for Teaching Mental Computation to Students in the Early Years of Schooling

ERIC Educational Resources Information Center

Russo, James

2015-01-01

In this article James Russo presents the Strategies, Understanding, Reading and Fast Facts Framework (SURF) for mental computation. He explains how this framework can be used to deepen mathematical understanding and build mental flexibility.

Surf zone fish diet as an indicator of environmental and anthropogenic influences

NASA Astrophysics Data System (ADS)

Costa, Leonardo Lopes; Zalmon, Ilana Rosental

2017-10-01

Changes in species' abundance have been used as indicators of environmental and anthropogenic disturbances. However, sublethal, e.g., diet, changes should be detected before some alterations in the composition and structure of fish assemblages occur as a result of ecological negative impacts. The objective of the present study was to assess possible changes in surf zone fish diet in response to environmental and anthropogenic disturbances. Surf zone fish were sampled and their stomach contents were analyzed on two sandy beaches under different levels of human pressure in Southeastern Brazil. Habitat variables related to seasonality, food availability, anthropogenic disturbance, upwelling and river influence were measured as follows: (1) wave height; (2) water temperature; (3) intertidal macroinvertebrates abundance; (4) solid waste amount; (5) salinity; (6) particulate organic carbon (POC) and (7) chlorophyll a (Chl a). Our results showed the influence of seasonality, prey abundance and hydrodynamics in prey selection, and diet overlap between typical surf zone residents. A literature search was also performed and it shows that insects and Emerita brasiliensis eggs, which were the main food item consumed by some surf zone fish at urbanized Brazilian beaches, are unusual worldwide. Furthermore, solid waste was related to high consumption of insects by pompanos fish in urbanized areas, suggesting that this fish diet could be a sublethal indicator of human impact on sandy beaches.

The Ocean as a Unique Therapeutic Environment: Developing a Surfing Program

ERIC Educational Resources Information Center

Clapham, Emily D.; Armitano, Cortney N.; Lamont, Linda S.; Audette, Jennifer G.

2014-01-01

Educational aquatic programming offers necessary physical activity opportunities to children with disabilities and the benefits of aquatic activities are more pronounced for children with disabilities than for their able-bodied peers. Similar benefits could potentially be derived from surfing in the ocean. This article describes an adapted surfing…

Safety Strategies While Surfing Online in the Classroom.

ERIC Educational Resources Information Center

Demirbilek, Muhammet; Cilesiz, Sebnem; Tozoglu, Dogan

The Internet has become an indispensable medium of the 21st century. Millions of people are using the Internet for exchanging information, surfing for information on virtually any topic, communicating all over the world, participating in discussion groups, shopping, traveling, and many other online activities. The World Wide Web is constantly…

Feature Selection and Pedestrian Detection Based on Sparse Representation.

PubMed

Yao, Shihong; Wang, Tao; Shen, Weiming; Pan, Shaoming; Chong, Yanwen; Ding, Fei

2015-01-01

Pedestrian detection have been currently devoted to the extraction of effective pedestrian features, which has become one of the obstacles in pedestrian detection application according to the variety of pedestrian features and their large dimension. Based on the theoretical analysis of six frequently-used features, SIFT, SURF, Haar, HOG, LBP and LSS, and their comparison with experimental results, this paper screens out the sparse feature subsets via sparse representation to investigate whether the sparse subsets have the same description abilities and the most stable features. When any two of the six features are fused, the fusion feature is sparsely represented to obtain its important components. Sparse subsets of the fusion features can be rapidly generated by avoiding calculation of the corresponding index of dimension numbers of these feature descriptors; thus, the calculation speed of the feature dimension reduction is improved and the pedestrian detection time is reduced. Experimental results show that sparse feature subsets are capable of keeping the important components of these six feature descriptors. The sparse features of HOG and LSS possess the same description ability and consume less time compared with their full features. The ratios of the sparse feature subsets of HOG and LSS to their full sets are the highest among the six, and thus these two features can be used to best describe the characteristics of the pedestrian and the sparse feature subsets of the combination of HOG-LSS show better distinguishing ability and parsimony.

Collection and corrections of oblique multiangle hyperspectral bidirectional reflectance imagery of the water surface

NASA Astrophysics Data System (ADS)

Bostater, Charles R.; Oney, Taylor S.

2017-10-01

Hyperspectral images of coastal waters in urbanized regions were collected from fixed platform locations. Surf zone imagery, images of shallow bays, lagoons and coastal waters are processed to produce bidirectional reflectance factor (BRF) signatures corrected for changing viewing angles. Angular changes as a function of pixel location within a scene are used to estimate changes in pixel size and ground sampling areas. Diffuse calibration targets collected simultaneously from within the image scene provides the necessary information for calculating BRF signatures of the water surface and shorelines. Automated scanning using a pushbroom hyperspectral sensor allows imagery to be collected on the order of one minute or less for different regions of interest. Imagery is then rectified and georeferenced using ground control points within nadir viewing multispectral imagery via image to image registration techniques. This paper demonstrates the above as well as presenting how spectra can be extracted along different directions in the imagery. The extraction of BRF spectra along track lines allows the application of derivative reflectance spectroscopy for estimating chlorophyll-a, dissolved organic matter and suspended matter concentrations at or near the water surface. Imagery is presented demonstrating the techniques to identify subsurface features and targets within the littoral and surf zones.

Genotypes and clinical phenotypes in children with cytochrome-c oxidase deficiency.

PubMed

Darin, N; Moslemi, A-R; Lebon, S; Rustin, P; Holme, E; Oldfors, A; Tulinius, M

2003-12-01

Cytochrome c oxidase (COX) deficiency has been associated with a wide spectrum of clinical features and may be caused by mutations in different genes of both the mitochondrial and the nuclear DNA. In an attempt to correlate the clinical phenotype with the genotype in 16 childhood cases, mtDNA was analysed for deletion, depletion, and mutations in the three genes encoding COX subunits and the 22 tRNA genes. Furthermore, nuclear DNA was analysed for mutations in the SURF1, SCO2, COX10, and COX17 genes and cases with mtDNA depletion were analysed for mutations in the TK2 gene. SURF1-mutations were identified in three out of four cases with Leigh syndrome while a mutation in the mitochondrial tRNA (trp) gene was identified in the fourth. One case with mtDNA depletion had mutations in the TK2 gene. In two cases with leukoencephalopathy, one case with encephalopathy, five cases with fatal infantile myopathy and cardiomyopathy, two cases with benign infantile myopathy, and one case with mtDNA depletion, no mutations were identified. We conclude that COX deficiency in childhood should be suspected in a wide range of clinical settings and although an increasing number of genetic defects have been identified, the underlying mutations remain unclear in the majority of the cases.

The effects of variations in parameters and algorithm choices on calculated radiomics feature values: initial investigations and comparisons to feature variability across CT image acquisition conditions

NASA Astrophysics Data System (ADS)

Emaminejad, Nastaran; Wahi-Anwar, Muhammad; Hoffman, John; Kim, Grace H.; Brown, Matthew S.; McNitt-Gray, Michael

2018-02-01

Translation of radiomics into clinical practice requires confidence in its interpretations. This may be obtained via understanding and overcoming the limitations in current radiomic approaches. Currently there is a lack of standardization in radiomic feature extraction. In this study we examined a few factors that are potential sources of inconsistency in characterizing lung nodules, such as 1)different choices of parameters and algorithms in feature calculation, 2)two CT image dose levels, 3)different CT reconstruction algorithms (WFBP, denoised WFBP, and Iterative). We investigated the effect of variation of these factors on entropy textural feature of lung nodules. CT images of 19 lung nodules identified from our lung cancer screening program were identified by a CAD tool and contours provided. The radiomics features were extracted by calculating 36 GLCM based and 4 histogram based entropy features in addition to 2 intensity based features. A robustness index was calculated across different image acquisition parameters to illustrate the reproducibility of features. Most GLCM based and all histogram based entropy features were robust across two CT image dose levels. Denoising of images slightly improved robustness of some entropy features at WFBP. Iterative reconstruction resulted in improvement of robustness in a fewer times and caused more variation in entropy feature values and their robustness. Within different choices of parameters and algorithms texture features showed a wide range of variation, as much as 75% for individual nodules. Results indicate the need for harmonization of feature calculations and identification of optimum parameters and algorithms in a radiomics study.

Actin- and myosin-driven movement of viruses along filopodia precedes their entry into cells.

PubMed

Lehmann, Maik J; Sherer, Nathan M; Marks, Carolyn B; Pypaert, Marc; Mothes, Walther

2005-07-18

Viruses have often been observed in association with the dense microvilli of polarized epithelia as well as the filopodia of nonpolarized cells, yet whether interactions with these structures contribute to infection has remained unknown. Here we show that virus binding to filopodia induces a rapid and highly ordered lateral movement, "surfing" toward the cell body before cell entry. Virus cell surfing along filopodia is mediated by the underlying actin cytoskeleton and depends on functional myosin II. Any disruption of virus cell surfing significantly reduces viral infection. Our results reveal another example of viruses hijacking host machineries for efficient infection by using the inherent ability of filopodia to transport ligands to the cell body.

Degree of anisotropy as an automated indicator of rip channels in high resolution bathymetric models

NASA Astrophysics Data System (ADS)

Trimble, S. M.; Houser, C.; Bishop, M. P.

2017-12-01

A rip current is a concentrated seaward flow of water that forms in the surf zone of a beach as a result of alongshore variations in wave breaking. Rips can carry swimmers swiftly into deep water, and they are responsible for hundreds of fatal drownings and thousands of rescues worldwide each year. These currents form regularly alongside hard structures like piers and jetties, and can also form along sandy coasts when there is a three dimensional bar morphology. This latter rip type tends to be variable in strength and location, making them arguably the most dangerous to swimmers and most difficult to identify. These currents form in characteristic rip channels in surf zone bathymetry, in which the primary axis of self-similarity is oriented shore-normal. This paper demonstrates a new method for automating identification of such rip channels in bathymetric digital surface models (DSMs) using bathymetric data collected by various remote sensing methods. Degree of anisotropy is used to detect rip channels and distinguishes between sandbars, rip channels, and other beach features. This has implications for coastal geomorphology theory and safety practices. As technological advances increase access and accuracy of topobathy mapping methods in the surf zone, frequent nearshore bathymetric DSMs could be more easily captured and processed, then analyzed with this method to result in localized, automated, and frequent detection of rip channels. This could ultimately reduce rip-related fatalities worldwide (i) in present mitigation, by identifying the present location of rip channels, (ii) in forecasting, by tracking the channel's evolution through multiple DSMs, and (iii) in rip education by improving local lifeguard knowledge of the rip hazard. Although this paper on applies analysis of degree of anisotropy to the identification of rip channels, this parameter can be applied to multiple facets of barrier island morphological analysis.

Surfzone Currents Over Irregular Bathymetry: Drifter Observations and Numerical Model Results

NASA Astrophysics Data System (ADS)

Schmidt, W. E.; Slinn, D. N.; Guza, R. T.

2002-12-01

Surfzone currents on alongshore variable bathymetry were observed with recently developed GPS-tracked drifters and numerically modeled with the time-dependent, nonlinear shallow water equations. These currents, forced by alongshore inhomogeneous pressure and radiation stress gradients, contain flow features difficult to resolve with fixed instrument arrays, such as rips, eddies, and meanders. Drifters were repeatedly released and recovered near Scripps Beach, La Jolla, California, in July 2000, 2001, and 2002. The most recent deployment of 10 drifters yielded about 32 hours of drifter data for each 5 hour deployment day. Offshore wave heights were moderate, between 0.3-1.0 m. The bathymetry, measured over a 600-700 m alongshore span with a GPS- and sonar-equipped jetski (2001 and 2002 deployments), was alongshore inhomogeneous primarily where an irregularly shaped bar-trough feature spanned the surf zone. The model simulations suggest that the alongshore inhomogeneous bathymetry strongly influences the location and strength of the observed flow features. Research supported by the California Sea Grant College Program and the Office of Naval Research.

Internet Surfing for Kindergarten Children: A Feasibility Study

ERIC Educational Resources Information Center

Loo, Alfred

2012-01-01

The Internet is an effective learning tool for gifted children because it allows them to independently select the areas in which they have talent. The Internet also enables children to discover and maximize their potential. However, younger children might not have a large enough vocabulary to surf the Internet, even if they are gifted. For…

Examining Risk-Taking Behavior and Sensation Seeking Requirement in Extreme Athletes

ERIC Educational Resources Information Center

Agilonu, Ali; Bastug, Gulsum; Mutlu, Tonguc Osman; Pala, Adem

2017-01-01

Extreme sports are sport branches which include actions, adventures, risks and difficulties more rather than other sports. Special materials are used in sport branches such as surfing, kite surfing, sailing, snowboarding, paragliding, diving, mountaineering, motor sports and adrenaline release is more rather than in other sport branches. On the…

50 CFR 648.77 - Framework adjustments to management measures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Management Measures for the Atlantic Surf Clam and Ocean Quahog Fisheries § 648.77 Framework adjustments to... the Atlantic Surf Clam and Ocean Quahog FMP if it finds that action is necessary to meet or be... fishing permit for surfclams and ocean quahogs: (a) Tagging. Before offloading, all cages that contain...

Promoting Internet Safety in Greek Primary Schools: the Teacher's Role

ERIC Educational Resources Information Center

Anastasiades, Panagiotes S.; Vitalaki, Elena

2011-01-01

The introduction of the Internet at schools has raised new pedagogical challenges facing educators trying to ensure children's awareness of the possible dangers when surfing the Web. This article aims to investigate how teachers evaluate the possible dangers that students might face when surfing the Net for various educational or interpersonal…

Two Japanese patients with Leigh syndrome caused by novel SURF1 mutations.

PubMed

Tanigawa, Junpei; Kaneko, Kaori; Honda, Masakazu; Harashima, Hiroko; Murayama, Kei; Wada, Takahito; Takano, Kyoko; Iai, Mizue; Yamashita, Sumimasa; Shimbo, Hiroko; Aida, Noriko; Ohtake, Akira; Osaka, Hitoshi

2012-11-01

We report two patients with Leigh syndrome that showed a combination of facial dysmorphism and MRI imaging indicating an SURF1 deficiency, which was confirmed by sequence analysis. Case 1 is a 3-year-old girl with failure to thrive and developmental delay. She presented with tachypnea at rest and displayed facial dysmorphism including frontal bossing, lateral displacement of inner canthi, esotropia, maxillary hypoplasia, slightly upturned nostril, and hypertrichosis dominant on the forehead and extremities. Case 2 is an 8-year-old boy with respiratory failure. He had been diagnosed as selective complex IV deficiency. Case 2 displayed facial dysmorphism and hypertrichosis. Since both patients displayed characteristic facial dysmorphism and MRI findings, we sequenced the SURF1 gene and identified two heterozygous mutations; c.49+1 G>T and c.752_753del in Case 1, and homozygous c.743 C>A in Case 2. For patients with Leigh syndrome showing these facial dysmorphism and hypertrichosis, sequence analysis of the SURF1 gene may be useful. Copyright © 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Mutations in the SURF1 gene associated with Leigh syndrome and cytochrome C oxidase deficiency.

PubMed

Péquignot, M O; Dey, R; Zeviani, M; Tiranti, V; Godinot, C; Poyau, A; Sue, C; Di Mauro, S; Abitbol, M; Marsac, C

2001-05-01

Cytochrome c oxidase (COX) deficiency is one of the major causes of Leigh Syndrome (LS), a fatal encephalopathy of infancy or childhood, characterized by symmetrical lesions in the basal ganglia and brainstem. Mutations in the nuclear genes encoding COX subunits have not been found in patients with LS and COX deficiency, but mutations have been identified in SURF1. SURF1 encodes a factor involved in COX biogenesis. To date, 30 different mutations have been reported in 40 unrelated patients. We aim to provide an overview of all known mutations in SURF1, and to propose a common nomenclature. Twelve of the mutations were insertion/deletion mutations in exons 1, 4, 6, 8, and 9; 10 were missense/nonsense mutations in exons 2, 4, 5, 7, and 8; and eight were detected at splicing sites in introns 3 to 7. The most frequent mutation was 312_321del 311_312insAT which was found in 12 patients out of 40. Twenty mutations have been described only once. We also list all polymorphisms discovered to date. Copyright 2001 Wiley-Liss, Inc.

Parenchymal texture analysis in digital mammography: robust texture feature identification and equivalence across devices.

PubMed

Keller, Brad M; Oustimov, Andrew; Wang, Yan; Chen, Jinbo; Acciavatti, Raymond J; Zheng, Yuanjie; Ray, Shonket; Gee, James C; Maidment, Andrew D A; Kontos, Despina

2015-04-01

An analytical framework is presented for evaluating the equivalence of parenchymal texture features across different full-field digital mammography (FFDM) systems using a physical breast phantom. Phantom images (FOR PROCESSING) are acquired from three FFDM systems using their automated exposure control setting. A panel of texture features, including gray-level histogram, co-occurrence, run length, and structural descriptors, are extracted. To identify features that are robust across imaging systems, a series of equivalence tests are performed on the feature distributions, in which the extent of their intersystem variation is compared to their intrasystem variation via the Hodges-Lehmann test statistic. Overall, histogram and structural features tend to be most robust across all systems, and certain features, such as edge enhancement, tend to be more robust to intergenerational differences between detectors of a single vendor than to intervendor differences. Texture features extracted from larger regions of interest (i.e., [Formula: see text]) and with a larger offset length (i.e., [Formula: see text]), when applicable, also appear to be more robust across imaging systems. This framework and observations from our experiments may benefit applications utilizing mammographic texture analysis on images acquired in multivendor settings, such as in multicenter studies of computer-aided detection and breast cancer risk assessment.

Robust extrema features for time-series data analysis.

PubMed

Vemulapalli, Pramod K; Monga, Vishal; Brennan, Sean N

2013-06-01

The extraction of robust features for comparing and analyzing time series is a fundamentally important problem. Research efforts in this area encompass dimensionality reduction using popular signal analysis tools such as the discrete Fourier and wavelet transforms, various distance metrics, and the extraction of interest points from time series. Recently, extrema features for analysis of time-series data have assumed increasing significance because of their natural robustness under a variety of practical distortions, their economy of representation, and their computational benefits. Invariably, the process of encoding extrema features is preceded by filtering of the time series with an intuitively motivated filter (e.g., for smoothing), and subsequent thresholding to identify robust extrema. We define the properties of robustness, uniqueness, and cardinality as a means to identify the design choices available in each step of the feature generation process. Unlike existing methods, which utilize filters "inspired" from either domain knowledge or intuition, we explicitly optimize the filter based on training time series to optimize robustness of the extracted extrema features. We demonstrate further that the underlying filter optimization problem reduces to an eigenvalue problem and has a tractable solution. An encoding technique that enhances control over cardinality and uniqueness is also presented. Experimental results obtained for the problem of time series subsequence matching establish the merits of the proposed algorithm.

Low-frequency electrical properties of peat

NASA Astrophysics Data System (ADS)

Comas, Xavier; Slater, Lee

2004-12-01

Electrical resistivity/induced polarization (0.1-1000 Hz) and vertical hydraulic conductivity (Kv) measurements of peat samples extracted from different depths (0-11 m) in a peatland in Maine were obtained as a function of pore fluid conductivity (σw) between 0.001 and 2 S/m. Hydraulic conductivity increased with σw (Kv ∝ σw0.3 between 0.001 and 2 S/m), indicating that pore dilation occurs due to the reaction of NaCl with organic functional groups as postulated by previous workers. Electrical measurements were modeled by assuming that "bulk" electrolytic conduction through the interconnected pore space and surface conduction in the electrical double layer (EDL) at the organic sediment-fluid interface act in parallel. This analysis suggests that pore space dilation causes a nonlinear relationship between the "bulk" electrolytic conductivity (σel) and σw (σel ∝ σw1.3). The Archie equation predicts a linear dependence of σel on σw and thus appears inappropriate for organic sediments. Induced polarization (IP) measurements of the imaginary part (σ″surf) of the surface conductivity (σ*surf) show that σ″surf is greater and more strongly σw-dependent (σ″surf ∝ σw0.5 between 0.001 and 2 S/m) than observed for inorganic sediments. By assuming a linear relationship between the real (σ'surf) and the imaginary part (σ″surf) of the surface conductivity, we develop an empirical model relating the resistivity and induced polarization measurements to σw in peat. We demonstrate the use of this model to predict (a) σw and (b) the change in Kv due to an incremental change in σw from resistivity and induced polarization measurements on organic sediments. Our study has implications for noninvasive geophysical characterization of σw and Kv with potential to benefit studies of carbon cycling and greenhouse gas fluxes as well as nutrient supply dynamics in peatlands.

Dispersal of fine sediment in nearshore coastal waters

USGS Publications Warehouse

Warrick, Jonathan A.

2013-01-01

Fine sediment (silt and clay) plays an important role in the physical, ecological, and environmental conditions of coastal systems, yet little is known about the dispersal and fate of fine sediment across coastal margin settings outside of river mouths. Here I provide simple physical scaling and detailed monitoring of a beach nourishment project near Imperial Beach, California, with a high portion of fines (40% silt and clay by weight). These results provide insights into the pathways and residence times of fine sediment transport across a wave-dominated coastal margin. Monitoring of the project used physical, optical, acoustic, and remote sensing techniques to track the fine portion of the nourishment sediment. The initial transport of fine sediment from the beach was influenced strongly by longshore currents of the surf zone that were established in response to the approach angles of the waves. The mean residence time of fine sediment in the surf zone—once it was suspended—was approximately 1 hour, and rapid decreases in surf zone fine sediment concentrations along the beach resulted from mixing and offshore transport in turbid rip heads. For example, during a day with oblique wave directions and surf zone longshore currents of approximately 25 cm/s, the offshore losses of fine sediment in rips resulted in a 95% reduction in alongshore surf zone fine sediment flux within 1 km of the nourishment site. However, because of the direct placement of nourishment sediment on the beach, fine suspended-sediment concentrations in the swash zone remained elevated for several days after nourishment, while fine sediment was winnowed from the beach. Once offshore of the surf zone, fine sediment settled downward in the water column and was observed to transport along and across the inner shelf. Vertically sheared currents influenced the directions and rates of fine sediment transport on the shelf. Sedimentation of fine sediment was greatest on the seafloor directly offshore of the nourishment site. However, a mass balance of sediment suggests that the majority of the fine sediment moved far away (over 2 km) from the nourishment site or to water depths greater than 10 m, where fine sediment represents a substantial portion of the bed material. Thus, the fate of fine sediment in nearshore waters was influenced strongly by wave conditions, surf zone and rip current transport, and the vertical density and flow conditions of coastal waters.

Northern Hemisphere Nitrous Oxide Morphology during the 1989 AASE and the 1991-1992 AASE 2 Campaigns

NASA Technical Reports Server (NTRS)

Podolske, James R.; Loewenstein, Max; Weaver, Alex; Strahan, Susan; Chan, K. Roland

1993-01-01

Nitrous oxide vertical profiles and latitudinal distributions for the 1989 AASE and 1992 AASE II northern polar winters are developed from the ATLAS N2O dataset, using both potential temperature and pressure as vertical coordinates. Morphologies show strong descent occurring poleward of the polar jet. The AASE II morphology shows a mid latitude 'surf zone,' characterized by strong horizontal mixing, and a horizontal gradient south of 30 deg N due to the sub-tropical jet. These features are similar to those produced by two-dimensional photochemical models which include coupling between transport, radiation, and chemistry.

Northern hemisphere nitrous oxide morphology during the 1989 AASE and the 1991-1992 AASE 2 campaigns

NASA Technical Reports Server (NTRS)

Podolske, James R.; Loewenstein, Max; Weaver, Alex; Strahan, Susan E.; Chan, K. Roland

1993-01-01

Nitrous oxide vertical profiles and latitudinal distributions for the 1989 Airborne Antarctic Ozone Experiment (AASE) and 1992 AASE 2 northern polar winters are developed from the ATLAS N2O dataset, using both potential temperature and pressure as vertical coordinates. Morphologies show strong descent occuring poleward of the polar jet. The AASE 2 morphology shows a mid latitude 'surf zone', characterized by strong horizontal mixing, and a horizontal gradient south of 30 deg N due to the sub-tropical jet. These features are similar to those produced by two-dimensional photochemical models which include coupling between transport, radiation, and chemistry.

The Web Surfer: What (Literacy) Skills Does It Take to Surf Anyway?

ERIC Educational Resources Information Center

Blackburn, Jessie

2010-01-01

This article looks closely at some of the lingering stereotypes that Composition Studies holds toward Web surfing and queries the resulting literacy hierarchy against our students' reading and writing practices that take place online. This article claims that while good progress has been made in the way of revising twenty-first century definitions…

A user's guide to the ssWavelets package

Treesearch

J.H. ​Gove

2017-01-01

ssWavelets is an R package that is meant to be used in conjunction with the sampSurf package (Gove, 2012) to perform wavelet decomposition on the results of a sampling surface simulation. In general, the wavelet filter decomposes the sampSurf simulation results by scale (distance), with each scale corresponding to a different level of the...

Modeling Water Waves with Smoothed Particle Hydrodynamics

DTIC Science & Technology

2013-09-30

SPH Model for Water Waves and Other Free Surface Flows ...Lagrangian nature of SPH allows the modeling of wave breaking, surf zones, ship waves, and wave-structure interaction, where the free surface becomes...proving to be a competent modeling scheme for free surface flows in three dimensions including the complex flows of the surf zone. As the GPU

The SCUBA map reduction cookbook

NASA Astrophysics Data System (ADS)

Sandell, G.; Jessop, N.; Jenness, T.

This cookbook tells you how to reduce and analyze maps obtained with SCUBA using the off-line SCUBA reduction package, SURF, and the Starlink KAPPA, Figaro, GAIA and CONVERT applications. The easiest way of using these packages is to run-up ORAC-DR, a general purpose pipeline for reducing data from any telescope. A set of data reduction recipes are available to ORAC-DR for use when working with scuba maps, these recipes utilize the SURF and KAPPA packages. This cookbook makes no attempts to explain why and how, for that there is a comprehensive Starlink User Note 216 which properly documents all the software tasks in SURF, which should be consulted for those who need to know details of a task, or how the task really works.

Littoral transport in the surf zone elucidated by an Eulerian sediment tracer.

USGS Publications Warehouse

Duane, D.B.; James, W.R.

1980-01-01

An Eulerian, or time integration, sand tracer experiment was designed and carried out in the surf zone near Pt. Mugu, California on April 19, 1972. Data indicate that conditions of stationarity and finite boundaries required for proper application of Eulerian tracer theory exist for short time periods in the surf zone. Grain counts suggest time required for tracer sand to attain equilibrium concentration is on the order of 30-60 minutes. Grain counts also indicate transport (discharge) was strongly dependent upon grain size, with the maximum rate occurring in the size 2.5-2.75 phi, decreasing to both finer and coarser sizes. The measured instantaneous transport was at the annual rate of 2.4 x 106 m3/yr.- Authors

InterProSurf: a web server for predicting interacting sites on protein surfaces

PubMed Central

Negi, Surendra S.; Schein, Catherine H.; Oezguen, Numan; Power, Trevor D.; Braun, Werner

2009-01-01

Summary A new web server, InterProSurf, predicts interacting amino acid residues in proteins that are most likely to interact with other proteins, given the 3D structures of subunits of a protein complex. The prediction method is based on solvent accessible surface area of residues in the isolated subunits, a propensity scale for interface residues and a clustering algorithm to identify surface regions with residues of high interface propensities. Here we illustrate the application of InterProSurf to determine which areas of Bacillus anthracis toxins and measles virus hemagglutinin protein interact with their respective cell surface receptors. The computationally predicted regions overlap with those regions previously identified as interface regions by sequence analysis and mutagenesis experiments. PMID:17933856

Model comparisons of the reactive burn model SURF in three ASC codes

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

Whitley, Von Howard; Stalsberg, Krista Lynn; Reichelt, Benjamin Lee

A study of the SURF reactive burn model was performed in FLAG, PAGOSA and XRAGE. In this study, three different shock-to-detonation transition experiments were modeled in each code. All three codes produced similar model results for all the experiments modeled and at all resolutions. Buildup-to-detonation time, particle velocities and resolution dependence of the models was notably similar between the codes. Given the current PBX 9502 equations of state and SURF calibrations, each code is equally capable of predicting the correct detonation time and distance when impacted by a 1D impactor at pressures ranging from 10-16 GPa, as long as themore » resolution of the mesh is not too coarse.« less

A Preliminary Assessment of the SURF Reactive Burn Model Implementation in FLAG

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

Johnson, Carl Edward; McCombe, Ryan Patrick; Carver, Kyle

Properly validated and calibrated reactive burn models (RBM) can be useful engineering tools for assessing high explosive performance and safety. Experiments with high explosives are expensive. Inexpensive RBM calculations are increasingly relied on for predictive analysis for performance and safety. This report discusses the validation of Menikoff and Shaw’s SURF reactive burn model, which has recently been implemented in the FLAG code. The LANL Gapstick experiment is discussed as is its’ utility in reactive burn model validation. Data obtained from pRad for the LT-63 series is also presented along with FLAG simulations using SURF for both PBX 9501 and PBXmore » 9502. Calibration parameters for both explosives are presented.« less

Collective bubble oscillations as a component of surf infrasound.

PubMed

Park, Joseph; Garcés, Milton; Fee, David; Pawlak, Geno

2008-05-01

Plunging surf is a known generator of infrasound, though the mechanisms have not been clearly identified. A model based on collective bubble oscillations created by demise of the initially entrained air pocket is examined. Computed spectra are compared to infrasound data from the island of Kauai during periods of medium, large, and extreme surf. Model results suggest that bubble oscillations generated by plunging waves are plausible generators of infrasound, and that dynamic bubble plume evolution on a temporal scale comparable to the breaking wave period may contribute to the broad spectral lobe of dominant infrasonic energy observed in measured data. Application of an inverse model has potential to characterize breaking wave size distributions, energy, and temporal changes in seafloor morphology based on remotely sensed infrasound.

E-O Propagation, Signature and System Performance Under Adverse Meteorological Conditions Considering Out-of-Area Operations (La Propagation, la Signature et les performances des Systemes optroniques dans des Conditions Meteorologiques Defavorables, compte Tenu des Operations hors Zone)

DTIC Science & Technology

1998-09-01

distribution CSAS-100-HV 7 m (Surf-2) 0.16-32 .gm PMS2 CSASP-200 Base of Pier 15 m (Surf-1,3) Aerosol size distribution 11.2 m (Surf-2) 0.2-20 pm PMS3 CSASP-100...270 4 180 V ~C2 go 1P-2 PMS3.(6m..) PM.Sl.(12.) PMS2 in.)... ...... Reference -2- ....... .... ..... ............... kn - .2 25 26 27 28 Day number...1 (12 in) are presently available do not allow for a more sophisticated 3 ..... PMS2 (15 m) approach. 2 The horizontal aerosol flux downwind from the

Biological robustness.

PubMed

Kitano, Hiroaki

2004-11-01

Robustness is a ubiquitously observed property of biological systems. It is considered to be a fundamental feature of complex evolvable systems. It is attained by several underlying principles that are universal to both biological organisms and sophisticated engineering systems. Robustness facilitates evolvability and robust traits are often selected by evolution. Such a mutually beneficial process is made possible by specific architectural features observed in robust systems. But there are trade-offs between robustness, fragility, performance and resource demands, which explain system behaviour, including the patterns of failure. Insights into inherent properties of robust systems will provide us with a better understanding of complex diseases and a guiding principle for therapy design.

Robust photometric invariant features from the color tensor.

PubMed

van de Weijer, Joost; Gevers, Theo; Smeulders, Arnold W M

2006-01-01

Luminance-based features are widely used as low-level input for computer vision applications, even when color data is available. The extension of feature detection to the color domain prevents information loss due to isoluminance and allows us to exploit the photometric information. To fully exploit the extra information in the color data, the vector nature of color data has to be taken into account and a sound framework is needed to combine feature and photometric invariance theory. In this paper, we focus on the structure tensor, or color tensor, which adequately handles the vector nature of color images. Further, we combine the features based on the color tensor with photometric invariant derivatives to arrive at photometric invariant features. We circumvent the drawback of unstable photometric invariants by deriving an uncertainty measure to accompany the photometric invariant derivatives. The uncertainty is incorporated in the color tensor, hereby allowing the computation of robust photometric invariant features. The combination of the photometric invariance theory and tensor-based features allows for detection of a variety of features such as photometric invariant edges, corners, optical flow, and curvature. The proposed features are tested for noise characteristics and robustness to photometric changes. Experiments show that the proposed features are robust to scene incidental events and that the proposed uncertainty measure improves the applicability of full invariants.

Automatic discrimination of color retinal images using the bag of words approach

NASA Astrophysics Data System (ADS)

Sadek, I.; Sidibé, D.; Meriaudeau, F.

2015-03-01

Diabetic retinopathy (DR) and age related macular degeneration (ARMD) are among the major causes of visual impairment all over the world. DR is mainly characterized by small red spots, namely microaneurysms and bright lesions, specifically exudates. However, ARMD is mainly identified by tiny yellow or white deposits called drusen. Since exudates might be the only visible signs of the early diabetic retinopathy, there is an increase demand for automatic diagnosis of retinopathy. Exudates and drusen may share similar appearances; as a result discriminating between them plays a key role in improving screening performance. In this research, we investigative the role of bag of words approach in the automatic diagnosis of retinopathy diabetes. Initially, the color retinal images are preprocessed in order to reduce the intra and inter patient variability. Subsequently, SURF (Speeded up Robust Features), HOG (Histogram of Oriented Gradients), and LBP (Local Binary Patterns) descriptors are extracted. We proposed to use single-based and multiple-based methods to construct the visual dictionary by combining the histogram of word occurrences from each dictionary and building a single histogram. Finally, this histogram representation is fed into a support vector machine with linear kernel for classification. The introduced approach is evaluated for automatic diagnosis of normal and abnormal color retinal images with bright lesions such as drusen and exudates. This approach has been implemented on 430 color retinal images, including six publicly available datasets, in addition to one local dataset. The mean accuracies achieved are 97.2% and 99.77% for single-based and multiple-based dictionaries respectively.

Logo recognition using alpha-rooted phase correlation in the radon transform domain

NASA Astrophysics Data System (ADS)

DelMarco, Stephen

2009-08-01

Alpha-rooted phase correlation (ARPC) is a recently-developed variant of classical phase correlation that includes a Fourier domain image enhancement operation. ARPC combines classical phase correlation with alpha-rooting to provide tunable image enhancement. The alpha-rooting parameters may be adjusted to provide a tradeoff between height and width of the ARPC main lobe. A high narrow main lobe peak provides high matching accuracy for aligned images, but reduced matching performance for misaligned logos. A lower, wider peak trades matching accuracy on aligned logos, for improved matching performance on misaligned imagery. Previously, we developed ARPC and used it in the spatial domain for logo recognition as part of an overall automated document analysis problem. However, spatial domain ARPC performance can be sensitive to logo misalignments, including rotational misalignment. In this paper we use ARPC as a match metric in the radon transform domain for logo recognition. In the radon transform domain, rotational misalignments correspond to translations in the radon transform angle parameter. These translations are captured by ARPC, thereby producing rotation-invariant logo matching. In the paper, we first present an overview of ARPC, and then describe the logo matching algorithm. We present numerical performance results demonstrating matching tolerance to rotational misalignments. We demonstrate robustness of the radon transform domain rotation estimation to noise. We present logo verification and recognition performance results using the proposed approach on a public domain logo database. We compare performance results to performance obtained using spatial domain ARPC, and state-of-the-art SURF features, for logos in salt-and-pepper noise.

Robust kernel representation with statistical local features for face recognition.

PubMed

Yang, Meng; Zhang, Lei; Shiu, Simon Chi-Keung; Zhang, David

2013-06-01

Factors such as misalignment, pose variation, and occlusion make robust face recognition a difficult problem. It is known that statistical features such as local binary pattern are effective for local feature extraction, whereas the recently proposed sparse or collaborative representation-based classification has shown interesting results in robust face recognition. In this paper, we propose a novel robust kernel representation model with statistical local features (SLF) for robust face recognition. Initially, multipartition max pooling is used to enhance the invariance of SLF to image registration error. Then, a kernel-based representation model is proposed to fully exploit the discrimination information embedded in the SLF, and robust regression is adopted to effectively handle the occlusion in face images. Extensive experiments are conducted on benchmark face databases, including extended Yale B, AR (A. Martinez and R. Benavente), multiple pose, illumination, and expression (multi-PIE), facial recognition technology (FERET), face recognition grand challenge (FRGC), and labeled faces in the wild (LFW), which have different variations of lighting, expression, pose, and occlusions, demonstrating the promising performance of the proposed method.

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.

SURF IA Conflict Detection and Resolution Algorithm Evaluation

NASA Technical Reports Server (NTRS)

Jones, Denise R.; Chartrand, Ryan C.; Wilson, Sara R.; Commo, Sean A.; Barker, Glover D.

2012-01-01

The Enhanced Traffic Situational Awareness on the Airport Surface with Indications and Alerts (SURF IA) algorithm was evaluated in a fast-time batch simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center. SURF IA is designed to increase flight crew situation awareness of the runway environment and facilitate an appropriate and timely response to potential conflict situations. The purpose of the study was to evaluate the performance of the SURF IA algorithm under various runway scenarios, multiple levels of conflict detection and resolution (CD&R) system equipage, and various levels of horizontal position accuracy. This paper gives an overview of the SURF IA concept, simulation study, and results. Runway incursions are a serious aviation safety hazard. As such, the FAA is committed to reducing the severity, number, and rate of runway incursions by implementing a combination of guidance, education, outreach, training, technology, infrastructure, and risk identification and mitigation initiatives [1]. Progress has been made in reducing the number of serious incursions - from a high of 67 in Fiscal Year (FY) 2000 to 6 in FY2010. However, the rate of all incursions has risen steadily over recent years - from a rate of 12.3 incursions per million operations in FY2005 to a rate of 18.9 incursions per million operations in FY2010 [1, 2]. The National Transportation Safety Board (NTSB) also considers runway incursions to be a serious aviation safety hazard, listing runway incursion prevention as one of their most wanted transportation safety improvements [3]. The NTSB recommends that immediate warning of probable collisions/incursions be given directly to flight crews in the cockpit [4].

Missense mutations in SURF1 associated with deficient cytochrome c oxidase assembly in Leigh syndrome patients.

PubMed

Poyau, A; Buchet, K; Bouzidi, M F; Zabot, M T; Echenne, B; Yao, J; Shoubridge, E A; Godinot, C

2000-02-01

We have studied the fibroblasts of three patients suffering from Leigh syndrome associated with cytochrome c oxidase deficiency (LS-COX-). Their mitochondrial DNA was functional and all nuclear COX subunits had a normal sequence. The expression of transcripts encoding mitochondrial and nuclear COX subunits was normal or slightly increased. Similarly, the OXA1 transcript coding for a protein involved in COX assembly was increased. However, several COX-protein subunits were severely depressed, indicating deficient COX assembly. Surf1, a factor involved in COX biogenesis, was recently reported as mutated in LS-COX- patients, all mutations predicting a truncated protein. Sequence analysis of SURF1 gene in our three patients revealed seven heterozygous mutations, six of which were new : an insertion, a nonsense mutation, a splicing mutation of intron 7 in addition to three missense mutations. The mutation G385 A (Gly124-->Glu) changes a Gly that is strictly conserved in Surfl homologs of 12 species. The substitution G618 C (Asp202-->His), changing an Asp that is conserved only in mammals, appears to be a polymorphism. The mutation T751 C changes Ile246 to Thr, a position at which a hydrophobic amino acid is conserved in all eukaryotic and some bacterial species. Replacing Ile246 by Thr disrupts a predicted beta sheet structure present in all higher eukaryotes. COX activity could be restored in fibroblasts of the three patients by complementation with a retroviral vector containing normal SURF1 cDNA. These mutations identify domains essential to Surf1 protein structure and/or function.

Miniature Extreme Ultraviolet Solar Radiometers

NASA Astrophysics Data System (ADS)

McMullin, D. R.; Seely, J. F.; Bremer, J.; Jones, A. R.; Vest, R.; Sakdinawat, A.

2015-12-01

Free-standing zone plates for use in EUV solar radiometers have been fabricated using electron beam lithography and calibrated at the NIST SURF synchrotron facility. The radiometers that we are developing use zone plates (ZPs) to focus the total solar irradiance in narrow EUV spectral bands and measure it with negligible sensitivity to field angle and polarization, and with greater accuracy and greater long-term stability than radiometers that have alternative architectures. These radiometers are easy to accommodate on spacecraft due to their small size, low mass, low power requirements, low data rates, and modest pointing requirements. A proto-type instrument will be presented with performance characteristics and spacecraft resource requirements for hosting these new instruments. The compact size of the optical train make these zone plates attractive for small CubeSats. The robustness of the compact design makes these radiometers available for a large variety of applications.

Oceanography and Mine Warfare

DTIC Science & Technology

2000-03-13

of breaking waves , the position and strength of surface currents, and the propagation of the tide into very shallow waters. In the surf zone...6) sediment properties determine shock wave propagation , a method for mine neutralization in the surf zone. 48 OCEANOGRAPHY AND MINE WARFARE...mines will be buried in the sediments, sedimentary explosive shock wave propagation is critical for determining operational performance. Presently, we

Injuries of the spine sustained whilst surfboard riding.

PubMed

Dimmick, Simon; Brazier, Daivd; Wilson, Peter; Anderson, Suzanne E

2013-01-01

Surfboard riding is a popular sport worldwide. Although surfing is considered a 'safe' pastime, significant injuries do occur, particularly to the head and cervical spine. Spinal injuries most commonly occur when the surfer's head strikes the seafloor. This case series identifies the spectrum of spinal pathologies sustained whilst surfing and their imaging appearances. No similar study has previously been published.

Strengths Classification of Social Relationships among Cybermothers Raising Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Zeman, Laura Dreuth; Swanke, Jayme; Doktor, Judy

2011-01-01

Children with Autism Spectrum Disorders (ASD) and their families are different. Parents often surf the Internet in search of supportive solutions to the unique challenges they face. One source of insight for parents raising children with ASD comes from blog writers and the parents who surf the net to read their blogs, or cyberparents. The study…

Access Without Authentication: How and Why We Let Anyone Surf Our Wireless

ERIC Educational Resources Information Center

Watkins, Donna

2006-01-01

Wireless hotspots are popping up in local coffee shops everywhere. Anyone with a wireless-ready laptop or PDA can surf the Internet at one of these hotspots. The same is now true for all 32 branches of the Orange County Public Library (OCPL) in California. Though many public library systems are moving toward wireless access, most require patrons…

Mechanical interactions in bacterial colonies and the surfing probability of beneficial mutations.

PubMed

Farrell, Fred D; Gralka, Matti; Hallatschek, Oskar; Waclaw, Bartlomiej

2017-06-01

Bacterial conglomerates such as biofilms and microcolonies are ubiquitous in nature and play an important role in industry and medicine. In contrast to well-mixed cultures routinely used in microbial research, bacteria in a microcolony interact mechanically with one another and with the substrate to which they are attached. Here, we use a computer model of a microbial colony of rod-shaped cells to investigate how physical interactions between cells determine their motion in the colony and how this affects biological evolution. We show that the probability that a faster-growing mutant 'surfs' at the colony's frontier and creates a macroscopic sector depends on physical properties of cells (shape, elasticity and friction). Although all these factors contribute to the surfing probability in seemingly different ways, their effects can be summarized by two summary statistics that characterize the front roughness and cell alignment. Our predictions are confirmed by experiments in which we measure the surfing probability for colonies of different front roughness. Our results show that physical interactions between bacterial cells play an important role in biological evolution of new traits, and suggest that these interactions may be relevant to processes such as de novo evolution of antibiotic resistance. © 2017 The Author(s).

Does human pressure affect the community structure of surf zone fish in sandy beaches?

NASA Astrophysics Data System (ADS)

Costa, Leonardo Lopes; Landmann, Júlia G.; Gaelzer, Luiz R.; Zalmon, Ilana R.

2017-01-01

Intense tourism and human activities have resulted in habitat destruction in sandy beach ecosystems with negative impacts on the associated communities. To investigate whether urbanized beaches affect surf zone fish communities, fish and their benthic macrofaunal prey were collected during periods of low and high human pressure at two beaches on the Southeastern Brazilian coast. A BACI experimental design (Before-After-Control-Impact) was adapted for comparisons of tourism impact on fish community composition and structure in urbanized, intermediate and non-urbanized sectors of each beach. At the end of the summer season, we observed a significant reduction in fish richness, abundance, and diversity in the high tourist pressure areas. The negative association between visitors' abundance and the macrofaunal density suggests that urbanized beaches are avoided by surf zone fish due to higher human pressure and the reduction of food availability. Our results indicate that surf zone fish should be included in environmental impact studies in sandy beaches, including commercial species, e.g., the bluefish Pomatomus saltatrix. The comparative results from the less urbanized areas suggest that environmental zoning and visitation limits should be used as effective management and preservation strategies on beaches with high conservation potential.

Wave groupiness variations in the nearshore

USGS Publications Warehouse

List, J.H.

1991-01-01

This paper proposes a new definition of the groupiness factor, GF, based on the envelope of the incident-wave time series. It is shown that an envelope-based GF has several important advantages over the SIWEH-based groupiness factor, including objective criteria for determining the accuracy of the envelope function and well-defined numerical limits. Using this new GF, the variability of incident wave groupiness in the field is examined both temporally, in unbroken waves at a fixed location, and spatially, in a cross-shore array through the surf zone. Contrary to previous studies using the SIWEH-based GF, results suggest that incident wave groupiness may not be an independent parameter in unbroken waves; through a wide range of spectral shapes, from swell to storm waves, the groupiness did not vary significantly. As expected, the groupiness decreases rapidly as waves break through the surf zone, although significant wave height variability persists even through a saturated surf zone. The source of this inner surf zone groupiness is not identified; however, this observation implies that models of long wave generation must account for nonsteady radiation stress gradients landward of some narrow zone near the mean breakpoint. ?? 1991.

Temporal and spatial patterns for surf zone bacteria before and after disinfection of the orange county sanitation district effluent

USGS Publications Warehouse

Robertson, G.L.; Noble, M.A.; Xu, J. P.; Rosenfeld, L.K.; McGee, C.D.

2005-01-01

Data from pre- and post-disinfection fecal indicator bacteria (FIB) samples from final effluent, an offshore ocean outfall, and surf zone stations off Huntington Beach, CA were compared. Analysis of the results from these data sets confirmed that the ocean outfall was not the FIB source responsible for the postings and closures of local beaches that have occurred each summer since 1999. While FIB counts in the final effluent and offshore showed several order of magnitude reductions after disinfection, there were no significant reductions at the nearby surf zone stations. Additionally, the FIB spectral patterns suggest different sources. The dominant fortnightly cycle suggested that the source was related to the wetting and draining of the land from large spring tide tidal excursions.

Cytochrome C oxydase deficiency: SURF1 gene investigation in patients with Leigh syndrome.

PubMed

Maalej, Marwa; Kammoun, Thouraya; Alila-Fersi, Olfa; Kharrat, Marwa; Ammar, Marwa; Felhi, Rahma; Mkaouar-Rebai, Emna; Keskes, Leila; Hachicha, Mongia; Fakhfakh, Faiza

2018-03-18

Leigh syndrome (LS) is a rare progressive neurodegenerative disorder occurring in infancy. The most common clinical signs reported in LS are growth retardation, optic atrophy, ataxia, psychomotor retardation, dystonia, hypotonia, seizures and respiratory disorders. The paper reported a manifestation of 3 Tunisian patients presented with LS syndrome. The aim of this study is the MT[HYPHEN]ATP6 and SURF1 gene screening in Tunisian patients affected with classical Leigh syndrome and the computational investigation of the effect of detected mutations on its structure and functions by clinical and bioinformatics analyses. After clinical investigations, three Tunisian patients were tested for mutations in both MT-ATP6 and SURF1 genes by direct sequencing followed by in silico analyses to predict the effects of sequence variation. The result of mutational analysis revealed the absence of mitochondrial mutations in MT-ATP6 gene and the presence of a known homozygous splice site mutation c.516-517delAG in sibling patients added to the presence of a novel double het mutations in LS patient (c.752-18 A > C/c. c.751 + 16G > A). In silico analyses of theses intronic variations showed that it could alters splicing processes as well as SURF1 protein translation. Leigh syndrome (LS) is a rare progressive neurodegenerative disorder occurring in infancy. The most common clinical signs reported in LS are growth retardation, optic atrophy, ataxia, psychomotor retardation, dystonia, hypotonia, seizures and respiratory disorders. The paper reported a manifestation of 3 Tunisian patients presented with LS syndrome. The aim of this study is MT-ATP6 and SURF1 genes screening in Tunisian patients affected with classical Leigh syndrome and the computational investigation of the effect of detected mutations on its structure and functions. After clinical investigations, three Tunisian patients were tested for mutations in both MT-ATP6 and SURF1 genes by direct sequencing followed by in silico analysis to predict the effects of sequence variation. The result of mutational analysis revealed the absence of mitochondrial mutations in MT-ATP6 gene and the presence of a known homozygous splice site mutation c.516-517delAG in sibling patients added to the presence of a novel double het mutations in LS patient (c.752-18 A>C/ c.751+16G>A). In silico analysis of theses intronic vaiations showed that it could alters splicing processes as well as SURF1 protein translation. Copyright © 2018 Elsevier Inc. All rights reserved.

Automatic Image Registration of Multimodal Remotely Sensed Data with Global Shearlet Features

NASA Technical Reports Server (NTRS)

Murphy, James M.; Le Moigne, Jacqueline; Harding, David J.

2015-01-01

Automatic image registration is the process of aligning two or more images of approximately the same scene with minimal human assistance. Wavelet-based automatic registration methods are standard, but sometimes are not robust to the choice of initial conditions. That is, if the images to be registered are too far apart relative to the initial guess of the algorithm, the registration algorithm does not converge or has poor accuracy, and is thus not robust. These problems occur because wavelet techniques primarily identify isotropic textural features and are less effective at identifying linear and curvilinear edge features. We integrate the recently developed mathematical construction of shearlets, which is more effective at identifying sparse anisotropic edges, with an existing automatic wavelet-based registration algorithm. Our shearlet features algorithm produces more distinct features than wavelet features algorithms; the separation of edges from textures is even stronger than with wavelets. Our algorithm computes shearlet and wavelet features for the images to be registered, then performs least squares minimization on these features to compute a registration transformation. Our algorithm is two-staged and multiresolution in nature. First, a cascade of shearlet features is used to provide a robust, though approximate, registration. This is then refined by registering with a cascade of wavelet features. Experiments across a variety of image classes show an improved robustness to initial conditions, when compared to wavelet features alone.

Automatic Image Registration of Multi-Modal Remotely Sensed Data with Global Shearlet Features

PubMed Central

Murphy, James M.; Le Moigne, Jacqueline; Harding, David J.

2017-01-01

Automatic image registration is the process of aligning two or more images of approximately the same scene with minimal human assistance. Wavelet-based automatic registration methods are standard, but sometimes are not robust to the choice of initial conditions. That is, if the images to be registered are too far apart relative to the initial guess of the algorithm, the registration algorithm does not converge or has poor accuracy, and is thus not robust. These problems occur because wavelet techniques primarily identify isotropic textural features and are less effective at identifying linear and curvilinear edge features. We integrate the recently developed mathematical construction of shearlets, which is more effective at identifying sparse anisotropic edges, with an existing automatic wavelet-based registration algorithm. Our shearlet features algorithm produces more distinct features than wavelet features algorithms; the separation of edges from textures is even stronger than with wavelets. Our algorithm computes shearlet and wavelet features for the images to be registered, then performs least squares minimization on these features to compute a registration transformation. Our algorithm is two-staged and multiresolution in nature. First, a cascade of shearlet features is used to provide a robust, though approximate, registration. This is then refined by registering with a cascade of wavelet features. Experiments across a variety of image classes show an improved robustness to initial conditions, when compared to wavelet features alone. PMID:29123329

A short feature vector for image matching: The Log-Polar Magnitude feature descriptor

PubMed Central

Hast, Anders; Wählby, Carolina; Sintorn, Ida-Maria

2017-01-01

The choice of an optimal feature detector-descriptor combination for image matching often depends on the application and the image type. In this paper, we propose the Log-Polar Magnitude feature descriptor—a rotation, scale, and illumination invariant descriptor that achieves comparable performance to SIFT on a large variety of image registration problems but with much shorter feature vectors. The descriptor is based on the Log-Polar Transform followed by a Fourier Transform and selection of the magnitude spectrum components. Selecting different frequency components allows optimizing for image patterns specific for a particular application. In addition, by relying only on coordinates of the found features and (optionally) feature sizes our descriptor is completely detector independent. We propose 48- or 56-long feature vectors that potentially can be shortened even further depending on the application. Shorter feature vectors result in better memory usage and faster matching. This combined with the fact that the descriptor does not require a time-consuming feature orientation estimation (the rotation invariance is achieved solely by using the magnitude spectrum of the Log-Polar Transform) makes it particularly attractive to applications with limited hardware capacity. Evaluation is performed on the standard Oxford dataset and two different microscopy datasets; one with fluorescence and one with transmission electron microscopy images. Our method performs better than SURF and comparable to SIFT on the Oxford dataset, and better than SIFT on both microscopy datasets indicating that it is particularly useful in applications with microscopy images. PMID:29190737

"Sub-Surf Rocks"! An A-Level Resource Developed through an Industry-Education Collaboration

ERIC Educational Resources Information Center

Mather, Hazel

2012-01-01

A free internet resource called "Sub-Surf Rocks"! was launched in 2010. Its aim is to use seismic data obtained by the oil industry for enhancing the teaching of structural and economic geology at A-level (ages 16-18) in the UK. Seismic data gives a unique insight into the sub-surface and the many high-quality images coupled with…

Simulation of Pores Sealing During Homoepitaxy on Si(111) Surface

DTIC Science & Technology

2000-06-23

Yonehara, Jpn. J. Appi. Phys. 37, P2, N11B, 1354 (1998). [5] T. Ito, T. Yasumatsu and A. Hiraki , Appi. Surf Sci. 44, 97 (1990). [6] Y Yasumatsu, T. Ito...H. Nishizawa and A. Hiraki , Appl. Surf Sci. 48/49, 414 (199 1). [7] A. V. Zverev, 1. G. Neizvestny, N. L. Shwartz and Z. Sh. Yanovitskaya, Izv. RAS (Russian) 63, 356 (2000).

Surf zone fauna of Ecuadorian sandy beaches: Spatial and temporal patterns

NASA Astrophysics Data System (ADS)

Marin Jarrin, J. R.; Vanaverbeke, J.; Fockedey, N.; de Grunauer, M. del P. Cornejo R.; Dominguez-Granda, L.

2017-02-01

Sandy beaches and their surf zones are the most common open shoreline habitat; however, surf zone fauna in the tropics is one of the least studied communities in the world. In the current study, we tested the hypothesis that Ecuadorian surf zone hyperbenthos (invertebrates and vertebrates 1-5 mm in length) and epibenthos (fish and macrocrustaceans > 5 mm in length) vary among beaches and seasons. Therefore, the fauna was described and related to environmental variables. In addition, indicator taxa were identified. The hyperbenthos was divided into holo- and mero-hyperbenthos depending on whether taxa were present during their entire life or only early life stages, respectively. Samples were collected at eight different beaches during the wet, dry and intermediate or transitional season during the low spring tide, from 1999 to 2000, using a hyperbenthic sledge and epibenthic trawl. A total of 447 hyperbenthic and 30 epibenthic taxa were collected, most of which were crustaceans and fish, respectively (52 and 60% of taxa). The mysid, Metamysidopsis sp., was the most abundant member of the hyperbenthos (average ± SD: 14,425 ± 40,039 ind. 100 m- 2, present in 92% of samples collected), and the swimming blue crab, Areneus mexicanus, was the most encountered species among the epibenthos (1 ± 1 ind. 100 m- 2, 97% of samples collected). All faunal groups varied among beaches, while the holo-hyperbenthos and less strongly the epibenthos varied among seasons. Variability in the three faunas among beaches, distance from the continental slope and the Guayas estuarine system, and beach water physical characteristics were all strongly correlated suggesting adjacent habitats can influence surf zone biological communities and water physical characteristics. Seasonal effects were related to changes in water physical characteristics among seasons potentially reflecting changes in oceanic currents. These results suggest that, similarly to other beaches around the world, Ecuadorian surf zone fauna is abundant, diverse, and vary among beaches and, for some faunal groups, among seasons, potentially due to the influence of adjacent habitats and seasonal changes in oceanic currents.

Research on improving image recognition robustness by combining multiple features with associative memory

NASA Astrophysics Data System (ADS)

Guo, Dongwei; Wang, Zhe

2018-05-01

Convolutional neural networks (CNN) achieve great success in computer vision, it can learn hierarchical representation from raw pixels and has outstanding performance in various image recognition tasks [1]. However, CNN is easy to be fraudulent in terms of it is possible to produce images totally unrecognizable to human eyes that CNNs believe with near certainty are familiar objects. [2]. In this paper, an associative memory model based on multiple features is proposed. Within this model, feature extraction and classification are carried out by CNN, T-SNE and exponential bidirectional associative memory neural network (EBAM). The geometric features extracted from CNN and the digital features extracted from T-SNE are associated by EBAM. Thus we ensure the recognition of robustness by a comprehensive assessment of the two features. In our model, we can get only 8% error rate with fraudulent data. In systems that require a high safety factor or some key areas, strong robustness is extremely important, if we can ensure the image recognition robustness, network security will be greatly improved and the social production efficiency will be extremely enhanced.

Acute injury and chronic disability resulting from surfboard riding.

PubMed

Taylor, D McD; Bennett, D; Carter, M; Garewal, D; Finch, C F

2004-12-01

We undertook a cross-sectional survey of surfers at eight Victorian beaches between February and May 2003 and analysed acute injury and chronic disability sustained while surfing during the preceding 12 months. Significant injuries were defined as requiring medical attention or time off surfing/work. 646 surfers were enrolled (90.2% male, median age 27 years, median years of surfing 10). 145 surfers sustained 168 significant acute injuries in the preceding 12 months (0.26 injuries/surfer/year, 95% CI 0.22-0.30). Most were caused by striking a surfboard or another surfer (45.2%, 95% CI 37.6-53.1), "wiping out" (36.3%, 95% CI 29.1-44.1) or striking the seabed (17.9%, 95% CI 12.6-24.7). Injuries included lacerations (46.4%, 95% CI 38.8-54.3), sprains (28.6%, 95% CI 22.0-36.1), dislocations (10.7%, 95% CI 6.7-16.6) and fractures (8.9%, 95% CI 5.3-14.6). Body parts most frequently injured were the lower limb (45.8%, 95% CI 38.2-53.7) and the head/face (26.2%, 95% CI 19.9-33.6). Surfing injuries that were treated in Victorian emergency departments over a six year period revealed a similar pattern, although there was a greater proportion of head/face injuries (42.0%, 95% CI 36.0-48.1, p = 0.001). 20 surfers reported long-term effects from acute injuries, mainly unstable/stiff/painful joints. 136 surfers reported chronic health problems not related to acute injury including chronic/recurrent otitis externa and exostoses, muscle and joint pain/stiffness and pterygium. Significant injury while surfing is not uncommon. Although head injury accounts for a considerable proportion, very few surfers wear protective headgear. Greater use of protective headgear should be considered.

Injuries in recreational and competitive surfers: a nationwide study in Portugal.

PubMed

Minghelli, Beatriz; Nunes, Carla; Oliveira, Raul

2017-10-24

Surfers are subjected to external factors (ocean currents, wind orientation, wave size, contact with the board and other surfers) that require quick and efficient adaptations, increasing the risk of injury while riding waves. This study aimed to determine the incidence of injuries over a 12-month period in Portuguese surfers and to analyse the associated factors. The sample included 1,016 Portuguese surfers, aged between 8 and 64 years; 853 (84%) were male. A questionnaire was administered during the stages of the Regional Circuit Surf of Portugal. Three hundred and one (29.6%) surfers had an injury in the previous year, with a total of 398 injuries. There were 1.23 injuries per 1,000 hours of surfing. The most common injuries were lacerations (23.5%), located in the knee and leg (16.7%). Impacts of the board (27.1%), and injuries during paddling (17.9%) were the most prevalent injury mechanisms. Competitor surfers presented a higher risk of sustaining surfing- related injuries than recreational surfers (odds ratio= 1.81; 95%CI: 1.26-2.62; p=0.002). Individuals who had surfed for less than five years were at 1.65 more risk (95%CI: 1.13- 2.39; p=0.009) than those who had surfed for more than 10 years; surfers who trained at least three times a week had 1.42 the risk (95%CI: 1.08-1.87; p=0.011) than those who trained less. Injuries were frequent among Portuguese surfers, with specific affected body areas, mainly caused by impact with the board. It ́s necessary to create injury prevention strategies, including specific trainings and the use of protection material.

Remote Sensing Characterization of Two-dimensional Wave Forcing in the Surf Zone

NASA Astrophysics Data System (ADS)

Carini, R. J.; Chickadel, C. C.; Jessup, A. T.

2016-02-01

In the surf zone, breaking waves drive longshore currents, transport sediment, shape bathymetry, and enhance air-sea gas and particle exchange. Furthermore, wave group forcing influences the generation and duration of rip currents. Wave breaking exhibits large gradients in space and time, making it challenging to measure in situ. Remote sensing technologies, specifically thermal infrared (IR) imagery, can provide detailed spatial and temporal measurements of wave breaking at the water surface. We construct two-dimensional maps of active wave breaking from IR imagery collected during the Surf Zone Optics Experiment in September 2010 at the US Army Corps of Engineers' Field Research Facility in Duck, NC. For each breaker identified in the camera's field of view, the crest-perpendicular length of the aerated breaking region (roller length) and wave direction are estimated and used to compute the wave energy dissipation rate. The resultant dissipation rate maps are analyzed over different time scales: peak wave period, infragravity wave period, and tidal wave period. For each time scale, spatial maps of wave breaking are used to characterize wave forcing in the surf zone for a variety of wave conditions. The following phenomena are examined: (1) wave dissipation rates over the bar (location of most intense breaking) have increased variance in infragravity wave frequencies, which are different from the peak frequency of the incoming wave field and different from the wave forcing variability at the shoreline, and (2) wave forcing has a wider spatial distribution during low tide than during high tide due to depth-limited breaking over the barred bathymetry. Future work will investigate the response of the variability in wave setup, longshore currents and rip currents, to the variability in wave forcing in the surf zone.

Time Pattern Locking Scheme for Secure Multimedia Contents in Human-Centric Device

PubMed Central

Kim, Hyun-Woo; Kim, Jun-Ho; Park, Jong Hyuk; Jeong, Young-Sik

2014-01-01

Among the various smart multimedia devices, multimedia smartphones have become the most widespread due to their convenient portability and real-time information sharing, as well as various other built-in features. Accordingly, since personal and business activities can be carried out using multimedia smartphones without restrictions based on time and location, people have more leisure time and convenience than ever. However, problems such as loss, theft, and information leakage because of convenient portability have also increased proportionally. As a result, most multimedia smartphones are equipped with various built-in locking features. Pattern lock, personal identification numbers, and passwords are the most used locking features on current smartphones, but these are vulnerable to shoulder surfing and smudge attacks, allowing malicious users to bypass the security feature easily. In particular, the smudge attack technique is a convenient way to unlock multimedia smartphones after they have been stolen. In this paper, we propose the secure locking screen using time pattern (SLSTP) focusing on improved security and convenience for users to support human-centric multimedia device completely. The SLSTP can provide a simple interface to users and reduce the risk factors pertaining to security leakage to malicious third parties. PMID:25202737

Time pattern locking scheme for secure multimedia contents in human-centric device.

PubMed

Kim, Hyun-Woo; Kim, Jun-Ho; Park, Jong Hyuk; Jeong, Young-Sik

2014-01-01

Among the various smart multimedia devices, multimedia smartphones have become the most widespread due to their convenient portability and real-time information sharing, as well as various other built-in features. Accordingly, since personal and business activities can be carried out using multimedia smartphones without restrictions based on time and location, people have more leisure time and convenience than ever. However, problems such as loss, theft, and information leakage because of convenient portability have also increased proportionally. As a result, most multimedia smartphones are equipped with various built-in locking features. Pattern lock, personal identification numbers, and passwords are the most used locking features on current smartphones, but these are vulnerable to shoulder surfing and smudge attacks, allowing malicious users to bypass the security feature easily. In particular, the smudge attack technique is a convenient way to unlock multimedia smartphones after they have been stolen. In this paper, we propose the secure locking screen using time pattern (SLSTP) focusing on improved security and convenience for users to support human-centric multimedia device completely. The SLSTP can provide a simple interface to users and reduce the risk factors pertaining to security leakage to malicious third parties.

SurfKin: an ab initio kinetic code for modeling surface reactions.

PubMed

Le, Thong Nguyen-Minh; Liu, Bin; Huynh, Lam K

2014-10-05

In this article, we describe a C/C++ program called SurfKin (Surface Kinetics) to construct microkinetic mechanisms for modeling gas-surface reactions. Thermodynamic properties of reaction species are estimated based on density functional theory calculations and statistical mechanics. Rate constants for elementary steps (including adsorption, desorption, and chemical reactions on surfaces) are calculated using the classical collision theory and transition state theory. Methane decomposition and water-gas shift reaction on Ni(111) surface were chosen as test cases to validate the code implementations. The good agreement with literature data suggests this is a powerful tool to facilitate the analysis of complex reactions on surfaces, and thus it helps to effectively construct detailed microkinetic mechanisms for such surface reactions. SurfKin also opens a possibility for designing nanoscale model catalysts. Copyright © 2014 Wiley Periodicals, Inc.

Lack of robustness of textural measures obtained from 3D brain tumor MRIs impose a need for standardization.

PubMed

Molina, David; Pérez-Beteta, Julián; Martínez-González, Alicia; Martino, Juan; Velasquez, Carlos; Arana, Estanislao; Pérez-García, Víctor M

2017-01-01

Textural measures have been widely explored as imaging biomarkers in cancer. However, their robustness under dynamic range and spatial resolution changes in brain 3D magnetic resonance images (MRI) has not been assessed. The aim of this work was to study potential variations of textural measures due to changes in MRI protocols. Twenty patients harboring glioblastoma with pretreatment 3D T1-weighted MRIs were included in the study. Four different spatial resolution combinations and three dynamic ranges were studied for each patient. Sixteen three-dimensional textural heterogeneity measures were computed for each patient and configuration including co-occurrence matrices (CM) features and run-length matrices (RLM) features. The coefficient of variation was used to assess the robustness of the measures in two series of experiments corresponding to (i) changing the dynamic range and (ii) changing the matrix size. No textural measures were robust under dynamic range changes. Entropy was the only textural feature robust under spatial resolution changes (coefficient of variation under 10% in all cases). Textural measures of three-dimensional brain tumor images are not robust neither under dynamic range nor under matrix size changes. Standards should be harmonized to use textural features as imaging biomarkers in radiomic-based studies. The implications of this work go beyond the specific tumor type studied here and pose the need for standardization in textural feature calculation of oncological images.

Design of a Multi-Sensor Cooperation Travel Environment Perception System for Autonomous Vehicle

PubMed Central

Chen, Long; Li, Qingquan; Li, Ming; Zhang, Liang; Mao, Qingzhou

2012-01-01

This paper describes the environment perception system designed for intelligent vehicle SmartV-II, which won the 2010 Future Challenge. This system utilizes the cooperation of multiple lasers and cameras to realize several necessary functions of autonomous navigation: road curb detection, lane detection and traffic sign recognition. Multiple single scan lasers are integrated to detect the road curb based on Z-variance method. Vision based lane detection is realized by two scans method combining with image model. Haar-like feature based method is applied for traffic sign detection and SURF matching method is used for sign classification. The results of experiments validate the effectiveness of the proposed algorithms and the whole system.

Marine Life Study

NASA Technical Reports Server (NTRS)

1988-01-01

As a result of widespread ocean dumping and other pollution problems, marine scientists at Morgan State University are studying the populations of various marine organisms to determine the effects of pollution. They are also compiling data on the aging of marine organisms. There now exists a new method of determining the age of the surf clam. They are applying digital image processing to clam aging investigations. Computer creates digitized images of clam sections with annual rings. The image is enhanced -- manipulated to emphasize certain features in order to improve and amplify the information that can be extracted from the image. Also useful in other marine organisms that have growth bands making it easier to get an accurate count.

Evaluation of a Surfing Programme Designed to Increase Personal Well-Being and Connectedness to the Natural Environment among "At Risk" Young People

ERIC Educational Resources Information Center

Hignett, Amanda; White, Mathew P.; Pahl, Sabine; Jenkin, Rebecca; Froy, Mod Le

2018-01-01

Outdoor activities can be an important complement to classroom learning, especially for children/young people excluded, or at risk of exclusion, from mainstream schooling. The current research explored the impact of a 12-week surfing programme among such a group in the UK. Pre-post data on physiological health (heart rate (HR)/blood pressure),…

[Cytochrome c oxydase-deficient Leigh syndrome with homozygous mutation in SURF1 gene].

PubMed

Monnot, S; Chabrol, B; Cano, A; Pellissier, J F; Collignon, P; Montfort, M F; Paquis-Flucklinger, V

2005-05-01

Leigh syndrome is a heterogeneous disorder, usually due to a defect in oxidative metabolism. Mutations in SURF1 gene have been identified in patients with cytochrome c oxidase deficiency. We report a homozygous splice site deletion [516-2_516-1delAG] in a young girl presenting with cytochrome c oxidase-deficient Leigh syndrome. Identification of molecular defect is indispensable for genetic counselling and prenatal diagnosis.

Nanostructures: Physics and Technology International Symposium (8th) Held in St. Petersburg, Russia on June 19-23, 2000 Proceedings

DTIC Science & Technology

2000-06-23

Jpn. J. Appl. Phys. 37, P2, N11B, 1354 (1998). [5] T. Ito, T. Yasumatsu and A. Hiraki , Appl. Surf. Sci. 44, 97 (1990). [6] Y. Yasumatsu, T. Ito, H...Nishizawa and A. Hiraki , Appl. Surf. Sci. 48/49, 414 (1991). [7] A. V. Zverev, I. G. Neizvestny, N. L. Shwartz and Z. Sh. Yanovitskaya, Izv. RAS

Short-crested waves in the surf zone

NASA Astrophysics Data System (ADS)

Wei, Zhangping; Dalrymple, Robert A.; Xu, Munan; Garnier, Roland; Derakhti, Morteza

2017-05-01

This study investigates short-crested waves in the surf zone by using the mesh-free Smoothed Particle Hydrodynamics model, GPUSPH. The short-crested waves are created by generating intersecting wave trains in a numerical wave basin with a beach. We first validate the numerical model for short-crested waves by comparison with large-scale laboratory measurements. Then short-crested wave breaking over a planar beach is studied comprehensively. We observe rip currents as discussed in Dalrymple (1975) and undertow created by synchronous intersecting waves. The wave breaking of the short-crested wavefield created by the nonlinear superposition of intersecting waves and wave-current interaction result in the formation of isolated breakers at the ends of breaking wave crests. Wave amplitude diffraction at these isolated breakers gives rise to an increase in the alongshore wave number in the inner surf zone. Moreover, 3-D vortices and multiple circulation cells with a rotation frequency much lower than the incident wave frequency are observed across the outer surf zone to the beach. Finally, we investigate vertical vorticity generation under short-crested wave breaking and find that breaking of short-crested waves generates vorticity as pointed out by Peregrine (1998). Vorticity generation is not only observed under short-crested waves with a limited number of wave components but also under directional wave spectra.

Phenology and duration of remigial moult in Surf Scoters (Melanitta perspicillata) and White-winged Scoters (Melanitta fusca) on the Pacific coast of North America

USGS Publications Warehouse

Dickson, Rian D.; Esler, Daniel N.; Hupp, Jerry W.; Anderson, E.M.; Evenson, J.R.; Barrett, J.

2012-01-01

By quantifying phenology and duration of remigial moult in Surf Scoters (Melanitta perspicillata (L., 1758)) and White-winged Scoters (Melanitta fusca (L., 1758)), we tested whether timing of moult is dictated by temporal optima or constraints. Scoters (n = 3481) were captured during moult in Alaska, British Columbia, and Washington, and remigial emergence dates were determined. We provide evidence for a pre-emergence interval of 7.3 days that occurs after old primaries are shed and before new ones become visible. All age and sex classes of both scoter species exhibited a wide range of emergence dates (Surf Scoters: 26 June to 22 September; White-winged Scoters: 6 July to 21 September) suggestive of a lack of strong temporal optima for remigial moult. For both species, timing of moult was influenced by site, year, age, and sex. Relative to other waterfowl species, scoters have typical remigial growth rates (Surf Scoters: 3.9 mm·day–1; White-winged Scoters: 4.3 mm·day–1) but a long flightless period (34–49 days), in part because their relatively high wing-loading requires a greater proportion of feather regrowth to regain flight. Our data suggest that moulting scoters are not under strong selective pressure to complete moult quickly.

Vertical structure of mean cross-shore currents across a barred surf zone

USGS Publications Warehouse

Haines, John W.; Sallenger, Asbury H.

1994-01-01

Mean cross-shore currents observed across a barred surf zone are compared to model predictions. The model is based on a simplified momentum balance with a turbulent boundary layer at the bed. Turbulent exchange is parameterized by an eddy viscosity formulation, with the eddy viscosity Aυ independent of time and the vertical coordinate. Mean currents result from gradients due to wave breaking and shoaling, and the presence of a mean setup of the free surface. Descriptions of the wave field are provided by the wave transformation model of Thornton and Guza [1983]. The wave transformation model adequately reproduces the observed wave heights across the surf zone. The mean current model successfully reproduces the observed cross-shore flows. Both observations and predictions show predominantly offshore flow with onshore flow restricted to a relatively thin surface layer. Successful application of the mean flow model requires an eddy viscosity which varies horizontally across the surf zone. Attempts are made to parameterize this variation with some success. The data does not discriminate between alternative parameterizations proposed. The overall variability in eddy viscosity suggested by the model fitting should be resolvable by field measurements of the turbulent stresses. Consistent shortcomings of the parameterizations, and the overall modeling effort, suggest avenues for further development and data collection.

Robust Feature Selection Technique using Rank Aggregation.

PubMed

Sarkar, Chandrima; Cooley, Sarah; Srivastava, Jaideep

2014-01-01

Although feature selection is a well-developed research area, there is an ongoing need to develop methods to make classifiers more efficient. One important challenge is the lack of a universal feature selection technique which produces similar outcomes with all types of classifiers. This is because all feature selection techniques have individual statistical biases while classifiers exploit different statistical properties of data for evaluation. In numerous situations this can put researchers into dilemma as to which feature selection method and a classifiers to choose from a vast range of choices. In this paper, we propose a technique that aggregates the consensus properties of various feature selection methods to develop a more optimal solution. The ensemble nature of our technique makes it more robust across various classifiers. In other words, it is stable towards achieving similar and ideally higher classification accuracy across a wide variety of classifiers. We quantify this concept of robustness with a measure known as the Robustness Index (RI). We perform an extensive empirical evaluation of our technique on eight data sets with different dimensions including Arrythmia, Lung Cancer, Madelon, mfeat-fourier, internet-ads, Leukemia-3c and Embryonal Tumor and a real world data set namely Acute Myeloid Leukemia (AML). We demonstrate not only that our algorithm is more robust, but also that compared to other techniques our algorithm improves the classification accuracy by approximately 3-4% (in data set with less than 500 features) and by more than 5% (in data set with more than 500 features), across a wide range of classifiers.

Robust Segmentation of Planar and Linear Features of Terrestrial Laser Scanner Point Clouds Acquired from Construction Sites.

PubMed

Maalek, Reza; Lichti, Derek D; Ruwanpura, Janaka Y

2018-03-08

Automated segmentation of planar and linear features of point clouds acquired from construction sites is essential for the automatic extraction of building construction elements such as columns, beams and slabs. However, many planar and linear segmentation methods use scene-dependent similarity thresholds that may not provide generalizable solutions for all environments. In addition, outliers exist in construction site point clouds due to data artefacts caused by moving objects, occlusions and dust. To address these concerns, a novel method for robust classification and segmentation of planar and linear features is proposed. First, coplanar and collinear points are classified through a robust principal components analysis procedure. The classified points are then grouped using a new robust clustering method, the robust complete linkage method. A robust method is also proposed to extract the points of flat-slab floors and/or ceilings independent of the aforementioned stages to improve computational efficiency. The applicability of the proposed method is evaluated in eight datasets acquired from a complex laboratory environment and two construction sites at the University of Calgary. The precision, recall, and accuracy of the segmentation at both construction sites were 96.8%, 97.7% and 95%, respectively. These results demonstrate the suitability of the proposed method for robust segmentation of planar and linear features of contaminated datasets, such as those collected from construction sites.

Robust Segmentation of Planar and Linear Features of Terrestrial Laser Scanner Point Clouds Acquired from Construction Sites

PubMed Central

Maalek, Reza; Lichti, Derek D; Ruwanpura, Janaka Y

2018-01-01

Automated segmentation of planar and linear features of point clouds acquired from construction sites is essential for the automatic extraction of building construction elements such as columns, beams and slabs. However, many planar and linear segmentation methods use scene-dependent similarity thresholds that may not provide generalizable solutions for all environments. In addition, outliers exist in construction site point clouds due to data artefacts caused by moving objects, occlusions and dust. To address these concerns, a novel method for robust classification and segmentation of planar and linear features is proposed. First, coplanar and collinear points are classified through a robust principal components analysis procedure. The classified points are then grouped using a new robust clustering method, the robust complete linkage method. A robust method is also proposed to extract the points of flat-slab floors and/or ceilings independent of the aforementioned stages to improve computational efficiency. The applicability of the proposed method is evaluated in eight datasets acquired from a complex laboratory environment and two construction sites at the University of Calgary. The precision, recall, and accuracy of the segmentation at both construction sites were 96.8%, 97.7% and 95%, respectively. These results demonstrate the suitability of the proposed method for robust segmentation of planar and linear features of contaminated datasets, such as those collected from construction sites. PMID:29518062

Alternative Pop-Up for Surfers with Low Back Pain

PubMed Central

Loubert, Peter V.

2010-01-01

Surfing is enjoyed by many people around the world. A common problem in surfers is back pain during the “take-off,” specifically the “pop-up.” This article describes each part of the “take-off, and introduces an alternative to the “prone pop up” - called the “knee pop-up.” This alternative is a suggested technique to alleviate the stress in the lumbar spine during surfing. PMID:21509154

Terrorist Precursor Crimes: Issues and Options for Congress

DTIC Science & Technology

2007-05-24

iterated by the purported comments of Abu Bakar Bashir, spiritual leader of the al Qaeda-linked Jemaah Islamiyah (JI), an Islamist group in Indonesia ...and law enforcement in recent years.61 In August 2006, Abdel-Ilah Elmardoudi was convicted for operating a phone card “shoulder surfing ” scheme in...identification fraud charges and the fourth defendant was cleared of all charges.64 Beyond calling card surfing , there has been increasing concern

A Climatological Oil Spill Planning Guide. Number 2. Gulf of Maine/Georges Bank,

DTIC Science & Technology

1981-06-01

95 73 Shellfish Distribution: Surf clams and soft clams . . . . . 97 74 Shellfish Distribution: Ocean Quahogs and hard clams . . . . 98 75...have been included in the analysis. - 96 - 716 709 69’ No’ 670 No’ ILI Surf Clam Distribution ..... 45’ * Soft Clam Majo Concontraitln45 44 44’ N..w...18 7 Prevailing winter and summer pressure patterns in the North Atlantic . . . . . . .. .. . . . . . . . . . . . . . . 24 8 Storm tracks, winter

The positive impact of structured surfing courses on the wellbeing of vulnerable young people.

PubMed

Godfrey, Cath; Devine-Wright, Hannah; Taylor, Joe

2015-01-01

Involvement in positive leisure activities is a key way for young people to develop resilience and social and emotional skills. This paper outlines the evaluation of a six-week surfing intervention, the Wave Project, which aimed to boost wellbeing and confidence among 84 young people aged eight to 18, all of whom faced mental health issues or social exclusion. The intervention resulted in a significant and sustained increase in wellbeing. One year later, 70% of clients regularly attend a surf club and many have become trained as session volunteers. Parents and referrers noticed an increase in positive attitude and better communication, as well as improved self-management and behaviour at both home and school It is concluded that the Wave Project provides a demonstrable and cost-effective way to deliver mental health care, mentoring and social integration of young people. Further service evaluation of accessibility and long-term outcomes is also recommended.

[Athletic injuries in wind surfing].

PubMed

Mettler, R; Biener, K

1991-12-01

We made an anamnesis of sports related injuries for 189 members of the Swiss Wind Surfing Federation. This data enabled us to calculate an yearly incidence of 0.02 injuries per athlete. By comparison, this frequency amounts to 0.03 for tennis players, to 0.24 in football and 2.30 for competitive cyclists. Feet injuries made up for 36.5% of all cases, whereas legs were affected for 23.5%. The athlete had to stop his training for 25.2 days on average. His work had to be interrupted for 10.2 days and his mean hospital stay was of 2.0 days. One third of all injuries were due to board contact events, 20% happened on the shore and 19% were ascribed to falls on/of the mast. Bruises and other wounds were mainly due to the lack of surf-shoes and/or other protective clothing items.

Surf zone Exchange on a Rip Channeled Beach

NASA Astrophysics Data System (ADS)

Reniers, A.; Macmahan, J.

2008-12-01

The dispersion and surf zone exchange of GPS-equipped surface drifters observed during the Rip Current EXperiment (RCEX) is examined with help of Lagrangian Coherent Structures (LCSs). LCSs allow for the detection of transport barriers in unsteady flows and are typically applied to shelf-scale circulation systems. Here LCSs are specifically computed to detect the effects of surfzone-originated Very Low Frequency motions (VLFs) with O(10) minute time scale on the cross-shore exchange of floating material using numerical model calculations of the Lagrangian surface velocity at the wave group timescale. After verification with RCEX field observations, the model is run for a range of environmental conditions experienced during the field experiment to assess the effects of VLFs on the cross-shore surf zone exchange. Results are relevant for (but not restricted to) sediment and nutrient exchange, human health, water clarity, and swimmer safety.

Blind Channel Equalization Using Constrained Generalized Pattern Search Optimization and Reinitialization Strategy

NASA Astrophysics Data System (ADS)

Zaouche, Abdelouahib; Dayoub, Iyad; Rouvaen, Jean Michel; Tatkeu, Charles

2008-12-01

We propose a global convergence baud-spaced blind equalization method in this paper. This method is based on the application of both generalized pattern optimization and channel surfing reinitialization. The potentially used unimodal cost function relies on higher- order statistics, and its optimization is achieved using a pattern search algorithm. Since the convergence to the global minimum is not unconditionally warranted, we make use of channel surfing reinitialization (CSR) strategy to find the right global minimum. The proposed algorithm is analyzed, and simulation results using a severe frequency selective propagation channel are given. Detailed comparisons with constant modulus algorithm (CMA) are highlighted. The proposed algorithm performances are evaluated in terms of intersymbol interference, normalized received signal constellations, and root mean square error vector magnitude. In case of nonconstant modulus input signals, our algorithm outperforms significantly CMA algorithm with full channel surfing reinitialization strategy. However, comparable performances are obtained for constant modulus signals.

Archeological Survey and Testing in the Holy Cross Historic District, New Orleans, Louisiana. Volume 2

DTIC Science & Technology

1992-02-01

467 Table 4 Personal Items from Shovel Tests, 160R130. SURF SURF SURF N15 N5 NO NO $5 S5 1 2 3 W20 El5 E20 W10 E20 EO Bone button, Type B-5 Ceramic...Table 4 . Personal Items from Shovel Tests, 160R130. S15 S20 S20 S25 S25 S30 S30 S30 S32.5 E5 E35 E20 E50 E25 E50 E35 E20 E35 Bone button, Type B-5...1 1 1 7 1 471 Table 4 Personal Items from Shovel Tests, 160R130. S30 S34 S35 S45 S50 TOTAL El0 E35 E30 E30 E55 Bone button, Type B-5 1 1 Ceramic

Distinguishing high surf from volcanic long-period earthquakes

USGS Publications Warehouse

Lyons, John; Haney, Matt; Fee, David; Paskievitch, John F.

2014-01-01

Repeating long-period (LP) earthquakes are observed at active volcanoes worldwide and are typically attributed to unsteady pressure fluctuations associated with fluid migration through the volcanic plumbing system. Nonvolcanic sources of LP signals include ice movement and glacial outburst floods, and the waveform characteristics and frequency content of these events often make them difficult to distinguish from volcanic LP events. We analyze seismic and infrasound data from an LP swarm recorded at Pagan volcano on 12–14 October 2013 and compare the results to ocean wave data from a nearby buoy. We demonstrate that although the events show strong similarity to volcanic LP signals, the events are not volcanic but due to intense surf generated by a passing typhoon. Seismo-acoustic methods allow for rapid distinction of volcanic LP signals from those generated by large surf and other sources, a critical task for volcano monitoring.

Large-scale Atmospheric Transport Processes

NASA Technical Reports Server (NTRS)

Plumb, R. Alan

2004-01-01

Continuing earlier work, we continued an investigation of the seasonal behavior of the edges of the stratospheric surf zone. These edges form a barrier between the rapidly mixed surf zone and the relatively isolated tropics. In collaboration with Dr Lynn Sparling at GSFC, we used a statistical analysis of HALOE and CLAES trace gas data from UARS to identify and locate these edges during each UARS observing period. We found that the edges on both sides of the equator are present all year (a fact that is important for conceptual models of stratospheric transport), though that on the summer side of the equator is much less sharp than the winter edge. The edges migrate seasonally into the summer hemisphere. Their location also shows influence of the QBO, together with the SAO at higher altitudes. Comparisons with effective diffusivities, and the edge locations, suggest that the edge is sustained by surf zone entrainment during winter, but by the residual circulation during summer.

Invited Article: Refined analysis of synchrotron radiation for NIST's SURF III facility

NASA Astrophysics Data System (ADS)

Shirley, Eric L.; Furst, Mitchell; Arp, Uwe

2018-04-01

We have developed a new method for the exact calculation of synchrotron radiation for the National Institute of Standards and Technology Synchrotron Ultraviolet Radiation Facility, SURF III. Instead of using the Schwinger formula, which is only an approximation, we develop formulae based on Graf's addition theorem for Bessel functions and accurate asymptotic expansions for Hankel functions and Bessel functions. By measuring the radiation intensity profile at two distances from the storage ring, we also confirm an apparent vertical emittance that is consistent with the vertical betatron oscillations that are intentionally introduced to extend beam lifetime by spreading the electron beam spatially. Finally, we determine how much diffraction by beamline apertures enhances the spectral irradiance at an integrating sphere entrance port at the end station. This should eliminate small but treatable components of the uncertainty budget that one should consider when using SURF III or similar synchrotrons as standard, calculable sources of ultraviolet and other radiation.

Augmenting atlas-based liver segmentation for radiotherapy treatment planning by incorporating image features proximal to the atlas contours

NASA Astrophysics Data System (ADS)

Li, Dengwang; Liu, Li; Chen, Jinhu; Li, Hongsheng; Yin, Yong; Ibragimov, Bulat; Xing, Lei

2017-01-01

Atlas-based segmentation utilizes a library of previously delineated contours of similar cases to facilitate automatic segmentation. The problem, however, remains challenging because of limited information carried by the contours in the library. In this studying, we developed a narrow-shell strategy to enhance the information of each contour in the library and to improve the accuracy of the exiting atlas-based approach. This study presented a new concept of atlas based segmentation method. Instead of using the complete volume of the target organs, only information along the organ contours from the atlas images was used for guiding segmentation of the new image. In setting up an atlas-based library, we included not only the coordinates of contour points, but also the image features adjacent to the contour. In this work, 139 CT images with normal appearing livers collected for radiotherapy treatment planning were used to construct the library. The CT images within the library were first registered to each other using affine registration. The nonlinear narrow shell was generated alongside the object contours of registered images. Matching voxels were selected inside common narrow shell image features of a library case and a new case using a speed-up robust features (SURF) strategy. A deformable registration was then performed using a thin plate splines (TPS) technique. The contour associated with the library case was propagated automatically onto the new image by exploiting the deformation field vectors. The liver contour was finally obtained by employing level set based energy optimization within the narrow shell. The performance of the proposed method was evaluated by comparing quantitatively the auto-segmentation results with that delineated by physicians. A novel atlas-based segmentation technique with inclusion of neighborhood image features through the introduction of a narrow-shell surrounding the target objects was established. Application of the technique to 30 liver cases suggested that the technique was capable to reliably segment liver cases from CT, 4D-CT, and CBCT images with little human interaction. The accuracy and speed of the proposed method are quantitatively validated by comparing automatic segmentation results with the manual delineation results. The Jaccard similarity metric between the automatically generated liver contours obtained by the proposed method and the physician delineated results are on an average 90%-96% for planning images. Incorporation of image features into the library contours improves the currently available atlas-based auto-contouring techniques and provides a clinically practical solution for auto-segmentation. The proposed mountainous narrow shell atlas based method can achieve efficient automatic liver propagation for CT, 4D-CT and CBCT images with following treatment planning and should find widespread application in future treatment planning systems.

Augmenting atlas-based liver segmentation for radiotherapy treatment planning by incorporating image features proximal to the atlas contours.

PubMed

Li, Dengwang; Liu, Li; Chen, Jinhu; Li, Hongsheng; Yin, Yong; Ibragimov, Bulat; Xing, Lei

2017-01-07

Atlas-based segmentation utilizes a library of previously delineated contours of similar cases to facilitate automatic segmentation. The problem, however, remains challenging because of limited information carried by the contours in the library. In this studying, we developed a narrow-shell strategy to enhance the information of each contour in the library and to improve the accuracy of the exiting atlas-based approach. This study presented a new concept of atlas based segmentation method. Instead of using the complete volume of the target organs, only information along the organ contours from the atlas images was used for guiding segmentation of the new image. In setting up an atlas-based library, we included not only the coordinates of contour points, but also the image features adjacent to the contour. In this work, 139 CT images with normal appearing livers collected for radiotherapy treatment planning were used to construct the library. The CT images within the library were first registered to each other using affine registration. The nonlinear narrow shell was generated alongside the object contours of registered images. Matching voxels were selected inside common narrow shell image features of a library case and a new case using a speed-up robust features (SURF) strategy. A deformable registration was then performed using a thin plate splines (TPS) technique. The contour associated with the library case was propagated automatically onto the new image by exploiting the deformation field vectors. The liver contour was finally obtained by employing level set based energy optimization within the narrow shell. The performance of the proposed method was evaluated by comparing quantitatively the auto-segmentation results with that delineated by physicians. A novel atlas-based segmentation technique with inclusion of neighborhood image features through the introduction of a narrow-shell surrounding the target objects was established. Application of the technique to 30 liver cases suggested that the technique was capable to reliably segment liver cases from CT, 4D-CT, and CBCT images with little human interaction. The accuracy and speed of the proposed method are quantitatively validated by comparing automatic segmentation results with the manual delineation results. The Jaccard similarity metric between the automatically generated liver contours obtained by the proposed method and the physician delineated results are on an average 90%-96% for planning images. Incorporation of image features into the library contours improves the currently available atlas-based auto-contouring techniques and provides a clinically practical solution for auto-segmentation. The proposed mountainous narrow shell atlas based method can achieve efficient automatic liver propagation for CT, 4D-CT and CBCT images with following treatment planning and should find widespread application in future treatment planning systems.

Variability and robustness of scatterers in HRR/ISAR ground target data and its influence on the ATR performance

NASA Astrophysics Data System (ADS)

Schumacher, R.; Schimpf, H.; Schiller, J.

2011-06-01

The most challenging problem of Automatic Target Recognition (ATR) is the extraction of robust and independent target features which describe the target unambiguously. These features have to be robust and invariant in different senses: in time, between aspect views (azimuth and elevation angle), between target motion (translation and rotation) and between different target variants. Especially for ground moving targets in military applications an irregular target motion is typical, so that a strong variation of the backscattered radar signal with azimuth and elevation angle makes the extraction of stable and robust features most difficult. For ATR based on High Range Resolution (HRR) profiles and / or Inverse Synthetic Aperture Radar (ISAR) images it is crucial that the reference dataset consists of stable and robust features, which, among others, will depend on the target aspect and depression angle amongst others. Here it is important to find an adequate data grid for an efficient data coverage in the reference dataset for ATR. In this paper the variability of the backscattered radar signals of target scattering centers is analyzed for different HRR profiles and ISAR images from measured turntable datasets of ground targets under controlled conditions. Especially the dependency of the features on the elevation angle is analyzed regarding to the ATR of large strip SAR data with a large range of depression angles by using available (I)SAR datasets as reference. In this work the robustness of these scattering centers is analyzed by extracting their amplitude, phase and position. Therefore turntable measurements under controlled conditions were performed targeting an artificial military reference object called STANDCAM. Measures referring to variability, similarity, robustness and separability regarding the scattering centers are defined. The dependency of the scattering behaviour with respect to azimuth and elevation variations is analyzed. Additionally generic types of features (geometrical, statistical), which can be derived especially from (I)SAR images, are applied to the ATR-task. Therefore subsequently the dependence of individual feature values as well as the feature statistics on aspect (i.e. azimuth and elevation) are presented. The Kolmogorov-Smirnov distance will be used to show how the feature statistics is influenced by varying elevation angles. Finally, confusion matrices are computed between the STANDCAM target at all eleven elevation angles. This helps to assess the robustness of ATR performance under the influence of aspect angle deviations between training set and test set.

Lack of robustness of textural measures obtained from 3D brain tumor MRIs impose a need for standardization

PubMed Central

Pérez-Beteta, Julián; Martínez-González, Alicia; Martino, Juan; Velasquez, Carlos; Arana, Estanislao; Pérez-García, Víctor M.

2017-01-01

Purpose Textural measures have been widely explored as imaging biomarkers in cancer. However, their robustness under dynamic range and spatial resolution changes in brain 3D magnetic resonance images (MRI) has not been assessed. The aim of this work was to study potential variations of textural measures due to changes in MRI protocols. Materials and methods Twenty patients harboring glioblastoma with pretreatment 3D T1-weighted MRIs were included in the study. Four different spatial resolution combinations and three dynamic ranges were studied for each patient. Sixteen three-dimensional textural heterogeneity measures were computed for each patient and configuration including co-occurrence matrices (CM) features and run-length matrices (RLM) features. The coefficient of variation was used to assess the robustness of the measures in two series of experiments corresponding to (i) changing the dynamic range and (ii) changing the matrix size. Results No textural measures were robust under dynamic range changes. Entropy was the only textural feature robust under spatial resolution changes (coefficient of variation under 10% in all cases). Conclusion Textural measures of three-dimensional brain tumor images are not robust neither under dynamic range nor under matrix size changes. Standards should be harmonized to use textural features as imaging biomarkers in radiomic-based studies. The implications of this work go beyond the specific tumor type studied here and pose the need for standardization in textural feature calculation of oncological images. PMID:28586353

Integrated Low-Rank-Based Discriminative Feature Learning for Recognition.

PubMed

Zhou, Pan; Lin, Zhouchen; Zhang, Chao

2016-05-01

Feature learning plays a central role in pattern recognition. In recent years, many representation-based feature learning methods have been proposed and have achieved great success in many applications. However, these methods perform feature learning and subsequent classification in two separate steps, which may not be optimal for recognition tasks. In this paper, we present a supervised low-rank-based approach for learning discriminative features. By integrating latent low-rank representation (LatLRR) with a ridge regression-based classifier, our approach combines feature learning with classification, so that the regulated classification error is minimized. In this way, the extracted features are more discriminative for the recognition tasks. Our approach benefits from a recent discovery on the closed-form solutions to noiseless LatLRR. When there is noise, a robust Principal Component Analysis (PCA)-based denoising step can be added as preprocessing. When the scale of a problem is large, we utilize a fast randomized algorithm to speed up the computation of robust PCA. Extensive experimental results demonstrate the effectiveness and robustness of our method.

Robust Radar Emitter Recognition Based on the Three-Dimensional Distribution Feature and Transfer Learning

PubMed Central

Yang, Zhutian; Qiu, Wei; Sun, Hongjian; Nallanathan, Arumugam

2016-01-01

Due to the increasing complexity of electromagnetic signals, there exists a significant challenge for radar emitter signal recognition. To address this challenge, multi-component radar emitter recognition under a complicated noise environment is studied in this paper. A novel radar emitter recognition approach based on the three-dimensional distribution feature and transfer learning is proposed. The cubic feature for the time-frequency-energy distribution is proposed to describe the intra-pulse modulation information of radar emitters. Furthermore, the feature is reconstructed by using transfer learning in order to obtain the robust feature against signal noise rate (SNR) variation. Last, but not the least, the relevance vector machine is used to classify radar emitter signals. Simulations demonstrate that the approach proposed in this paper has better performances in accuracy and robustness than existing approaches. PMID:26927111

Robust Radar Emitter Recognition Based on the Three-Dimensional Distribution Feature and Transfer Learning.

PubMed

Yang, Zhutian; Qiu, Wei; Sun, Hongjian; Nallanathan, Arumugam

2016-02-25

Due to the increasing complexity of electromagnetic signals, there exists a significant challenge for radar emitter signal recognition. To address this challenge, multi-component radar emitter recognition under a complicated noise environment is studied in this paper. A novel radar emitter recognition approach based on the three-dimensional distribution feature and transfer learning is proposed. The cubic feature for the time-frequency-energy distribution is proposed to describe the intra-pulse modulation information of radar emitters. Furthermore, the feature is reconstructed by using transfer learning in order to obtain the robust feature against signal noise rate (SNR) variation. Last, but not the least, the relevance vector machine is used to classify radar emitter signals. Simulations demonstrate that the approach proposed in this paper has better performances in accuracy and robustness than existing approaches.

a Photogrammetric Pipeline for the 3d Reconstruction of Cassis Images on Board Exomars Tgo

NASA Astrophysics Data System (ADS)

Simioni, E.; Re, C.; Mudric, T.; Pommerol, A.; Thomas, N.; Cremonese, G.

2017-07-01

CaSSIS (Colour and Stereo Surface Imaging System) is the stereo imaging system onboard the European Space Agency and ROSCOSMOS ExoMars Trace Gas Orbiter (TGO) that has been launched on 14 March 2016 and entered a Mars elliptical orbit on 19 October 2016. During the first bounded orbits, CaSSIS returned its first multiband images taken on 22 and 26 November 2016. The telescope acquired 11 images, each composed by 30 framelets, of the Martian surface near Hebes Chasma and Noctis Labyrithus regions reaching at closest approach at a distance of 250 km from the surface. Despite of the eccentricity of this first orbit, CaSSIS has provided one stereo pair with a mean ground resolution of 6 m from a mean distance of 520 km. The team at the Astronomical Observatory of Padova (OAPD-INAF) is involved into different stereo oriented missions and it is realizing a software for the generation of Digital Terrain Models from the CaSSIS images. The SW will be then adapted also for other projects involving stereo camera systems. To compute accurate 3D models, several sequential methods and tools have been developed. The preliminary pipeline provides: the generation of rectified images from the CaSSIS framelets, a matching core and post-processing methods. The software includes in particular: an automatic tie points detection by the Speeded Up Robust Features (SURF) operator, an initial search for the correspondences through Normalize Cross Correlation (NCC) algorithm and the Adaptive Least Square Matching (LSM) algorithm in a hierarchical approach. This work will show a preliminary DTM generated by the first CaSSIS stereo images.

Separable spectro-temporal Gabor filter bank features: Reducing the complexity of robust features for automatic speech recognition.

PubMed

Schädler, Marc René; Kollmeier, Birger

2015-04-01

To test if simultaneous spectral and temporal processing is required to extract robust features for automatic speech recognition (ASR), the robust spectro-temporal two-dimensional-Gabor filter bank (GBFB) front-end from Schädler, Meyer, and Kollmeier [J. Acoust. Soc. Am. 131, 4134-4151 (2012)] was de-composed into a spectral one-dimensional-Gabor filter bank and a temporal one-dimensional-Gabor filter bank. A feature set that is extracted with these separate spectral and temporal modulation filter banks was introduced, the separate Gabor filter bank (SGBFB) features, and evaluated on the CHiME (Computational Hearing in Multisource Environments) keywords-in-noise recognition task. From the perspective of robust ASR, the results showed that spectral and temporal processing can be performed independently and are not required to interact with each other. Using SGBFB features permitted the signal-to-noise ratio (SNR) to be lowered by 1.2 dB while still performing as well as the GBFB-based reference system, which corresponds to a relative improvement of the word error rate by 12.8%. Additionally, the real time factor of the spectro-temporal processing could be reduced by more than an order of magnitude. Compared to human listeners, the SNR needed to be 13 dB higher when using Mel-frequency cepstral coefficient features, 11 dB higher when using GBFB features, and 9 dB higher when using SGBFB features to achieve the same recognition performance.

SU-F-R-40: Robustness Test of Computed Tomography Textures of Lung Tissues to Varying Scanning Protocols Using a Realistic Phantom Environment

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

Lee, S; Markel, D; Hegyi, G

2016-06-15

Purpose: The reliability of computed tomography (CT) textures is an important element of radiomics analysis. This study investigates the dependency of lung CT textures on different breathing phases and changes in CT image acquisition protocols in a realistic phantom setting. Methods: We investigated 11 CT texture features for radiation-induced lung disease from 3 categories (first-order, grey level co-ocurrence matrix (GLCM), and Law’s filter). A biomechanical swine lung phantom was scanned at two breathing phases (inhale/exhale) and two scanning protocols set for PET/CT and diagnostic CT scanning. Lung volumes acquired from the CT images were divided into 2-dimensional sub-regions with amore » grid spacing of 31 mm. The distribution of the evaluated texture features from these sub-regions were compared between the two scanning protocols and two breathing phases. The significance of each factor on feature values were tested at 95% significance level using analysis of covariance (ANCOVA) model with interaction terms included. Robustness of a feature to a scanning factor was defined as non-significant dependence on the factor. Results: Three GLCM textures (variance, sum entropy, difference entropy) were robust to breathing changes. Two GLCM (variance, sum entropy) and 3 Law’s filter textures (S5L5, E5L5, W5L5) were robust to scanner changes. Moreover, the two GLCM textures (variance, sum entropy) were consistent across all 4 scanning conditions. First-order features, especially Hounsfield unit intensity features, presented the most drastic variation up to 39%. Conclusion: Amongst the studied features, GLCM and Law’s filter texture features were more robust than first-order features. However, the majority of the features were modified by either breathing phase or scanner changes, suggesting a need for calibration when retrospectively comparing scans obtained at different conditions. Further investigation is necessary to identify the sensitivity of individual image acquisition parameters.« less

Small-Scale Surf Zone Geometric Roughness

DTIC Science & Technology

2017-12-01

and an image of the tie points can be seen (Figure 6). 23 Figure 6. Screen Shot of Alignment Process On the left side is the workspace which...rest of the points, producing the 3D surface. 24 Figure 7. Screen Shot of Dense Cloud Process On the left side is the workspace which...maximum 200 words) Measurements of small-scale (O(mm)) geometric roughness (kf) associated with breaking wave foam were obtained within the surf zone on

Rip currents and alongshore flows in single channels dredged in the surf zone

NASA Astrophysics Data System (ADS)

Moulton, Melissa; Elgar, Steve; Raubenheimer, Britt; Warner, John C.; Kumar, Nirnimesh

2017-05-01

To investigate the dynamics of flows near nonuniform bathymetry, single channels (on average 30 m wide and 1.5 m deep) were dredged across the surf zone at five different times, and the subsequent evolution of currents and morphology was observed for a range of wave and tidal conditions. In addition, circulation was simulated with the numerical modeling system COAWST, initialized with the observed incident waves and channel bathymetry, and with an extended set of wave conditions and channel geometries. The simulated flows are consistent with alongshore flows and rip-current circulation patterns observed in the surf zone. Near the offshore-directed flows that develop in the channel, the dominant terms in modeled momentum balances are wave-breaking accelerations, pressure gradients, advection, and the vortex force. The balances vary spatially, and are sensitive to wave conditions and the channel geometry. The observed and modeled maximum offshore-directed flow speeds are correlated with a parameter based on the alongshore gradient in breaking-wave-driven-setup across the nonuniform bathymetry (a function of wave height and angle, water depths in the channel and on the sandbar, and a breaking threshold) and the breaking-wave-driven alongshore flow speed. The offshore-directed flow speed increases with dissipation on the bar and reaches a maximum (when the surf zone is saturated) set by the vertical scale of the bathymetric variability.

Rip currents and alongshore flows in single channels dredged in the surf zone

USGS Publications Warehouse

Moulton, Melissa; Elgar, Steve; Raubenheimer, Britt; Warner, John C.; Kumar, Nirnimesh

2017-01-01

To investigate the dynamics of flows near nonuniform bathymetry, single channels (on average 30 m wide and 1.5 m deep) were dredged across the surf zone at five different times, and the subsequent evolution of currents and morphology was observed for a range of wave and tidal conditions. In addition, circulation was simulated with the numerical modeling system COAWST, initialized with the observed incident waves and channel bathymetry, and with an extended set of wave conditions and channel geometries. The simulated flows are consistent with alongshore flows and rip-current circulation patterns observed in the surf zone. Near the offshore-directed flows that develop in the channel, the dominant terms in modeled momentum balances are wave-breaking accelerations, pressure gradients, advection, and the vortex force. The balances vary spatially, and are sensitive to wave conditions and the channel geometry. The observed and modeled maximum offshore-directed flow speeds are correlated with a parameter based on the alongshore gradient in breaking-wave-driven-setup across the nonuniform bathymetry (a function of wave height and angle, water depths in the channel and on the sandbar, and a breaking threshold) and the breaking-wave-driven alongshore flow speed. The offshore-directed flow speed increases with dissipation on the bar and reaches a maximum (when the surf zone is saturated) set by the vertical scale of the bathymetric variability.

A Robust Shape Reconstruction Method for Facial Feature Point Detection.

PubMed

Tan, Shuqiu; Chen, Dongyi; Guo, Chenggang; Huang, Zhiqi

2017-01-01

Facial feature point detection has been receiving great research advances in recent years. Numerous methods have been developed and applied in practical face analysis systems. However, it is still a quite challenging task because of the large variability in expression and gestures and the existence of occlusions in real-world photo shoot. In this paper, we present a robust sparse reconstruction method for the face alignment problems. Instead of a direct regression between the feature space and the shape space, the concept of shape increment reconstruction is introduced. Moreover, a set of coupled overcomplete dictionaries termed the shape increment dictionary and the local appearance dictionary are learned in a regressive manner to select robust features and fit shape increments. Additionally, to make the learned model more generalized, we select the best matched parameter set through extensive validation tests. Experimental results on three public datasets demonstrate that the proposed method achieves a better robustness over the state-of-the-art methods.

Efficient and robust model-to-image alignment using 3D scale-invariant features.

PubMed

Toews, Matthew; Wells, William M

2013-04-01

This paper presents feature-based alignment (FBA), a general method for efficient and robust model-to-image alignment. Volumetric images, e.g. CT scans of the human body, are modeled probabilistically as a collage of 3D scale-invariant image features within a normalized reference space. Features are incorporated as a latent random variable and marginalized out in computing a maximum a posteriori alignment solution. The model is learned from features extracted in pre-aligned training images, then fit to features extracted from a new image to identify a globally optimal locally linear alignment solution. Novel techniques are presented for determining local feature orientation and efficiently encoding feature intensity in 3D. Experiments involving difficult magnetic resonance (MR) images of the human brain demonstrate FBA achieves alignment accuracy similar to widely-used registration methods, while requiring a fraction of the memory and computation resources and offering a more robust, globally optimal solution. Experiments on CT human body scans demonstrate FBA as an effective system for automatic human body alignment where other alignment methods break down. Copyright © 2012 Elsevier B.V. All rights reserved.

Efficient and Robust Model-to-Image Alignment using 3D Scale-Invariant Features

PubMed Central

Toews, Matthew; Wells, William M.

2013-01-01

This paper presents feature-based alignment (FBA), a general method for efficient and robust model-to-image alignment. Volumetric images, e.g. CT scans of the human body, are modeled probabilistically as a collage of 3D scale-invariant image features within a normalized reference space. Features are incorporated as a latent random variable and marginalized out in computing a maximum a-posteriori alignment solution. The model is learned from features extracted in pre-aligned training images, then fit to features extracted from a new image to identify a globally optimal locally linear alignment solution. Novel techniques are presented for determining local feature orientation and efficiently encoding feature intensity in 3D. Experiments involving difficult magnetic resonance (MR) images of the human brain demonstrate FBA achieves alignment accuracy similar to widely-used registration methods, while requiring a fraction of the memory and computation resources and offering a more robust, globally optimal solution. Experiments on CT human body scans demonstrate FBA as an effective system for automatic human body alignment where other alignment methods break down. PMID:23265799

An effect of couterion in STM imaging process of DNA on Cu(111)

NASA Astrophysics Data System (ADS)

Furukawa, Masashi; Nishimura, Makoto; Tanaka, Hiroyuki; Kawai, Tomoji

2002-03-01

In order to elucidate electrical conduction mechanism of DNA, which is still under debate over the last decade, we have performed local electronic structure measurement of single- and double-stranded DNA molecules adsorbed onto Cu(111) surfaces using scanning tunneling microscope (STM). Bias-voltage-dependent STM images (from -5 V to +5 V) have shown that the molecular corrugation height in STM increases gradually at positive bias voltage region (empty state). Despite the theoretical assumption in which their 1st-LUMO states are localized at π plane of DNA bases, one cannot conclude its origin as the existence of their LUMO states, based on the results of relevant control measurements, DNA base molecules/Cu(111) [1] and NaCl/Cu(111). In fact, we found almost identical bias dependencies in the latter case (NaCl/Cu(111)), indicating that the feature of π* states of DNA bases should be buried in an additional channel that opens up by the onset of its unoccupied overlayer state in the tunneling process [2]. This study implies a potential difficulty in direct comparison of the obtained data with those characterized by XAS, in which π* states is located at ca. -1 eV relative to the Fermi level [3]. [1]M. Furukawa et al., submitted to Surf. Sci. [2] J. Kliewer et al., Surf. Sci. 477 (2001) 250.; A. Carlsson et al., Phys. Rev. B. 56 (1997) 1593. [3] M. Furukawa et al., submitted to Phys. Rev. B.

PredictProtein—an open resource for online prediction of protein structural and functional features

PubMed Central

Yachdav, Guy; Kloppmann, Edda; Kajan, Laszlo; Hecht, Maximilian; Goldberg, Tatyana; Hamp, Tobias; Hönigschmid, Peter; Schafferhans, Andrea; Roos, Manfred; Bernhofer, Michael; Richter, Lothar; Ashkenazy, Haim; Punta, Marco; Schlessinger, Avner; Bromberg, Yana; Schneider, Reinhard; Vriend, Gerrit; Sander, Chris; Ben-Tal, Nir; Rost, Burkhard

2014-01-01

PredictProtein is a meta-service for sequence analysis that has been predicting structural and functional features of proteins since 1992. Queried with a protein sequence it returns: multiple sequence alignments, predicted aspects of structure (secondary structure, solvent accessibility, transmembrane helices (TMSEG) and strands, coiled-coil regions, disulfide bonds and disordered regions) and function. The service incorporates analysis methods for the identification of functional regions (ConSurf), homology-based inference of Gene Ontology terms (metastudent), comprehensive subcellular localization prediction (LocTree3), protein–protein binding sites (ISIS2), protein–polynucleotide binding sites (SomeNA) and predictions of the effect of point mutations (non-synonymous SNPs) on protein function (SNAP2). Our goal has always been to develop a system optimized to meet the demands of experimentalists not highly experienced in bioinformatics. To this end, the PredictProtein results are presented as both text and a series of intuitive, interactive and visually appealing figures. The web server and sources are available at http://ppopen.rostlab.org. PMID:24799431

Efficient and robust computation of PDF features from diffusion MR signal.

PubMed

Assemlal, Haz-Edine; Tschumperlé, David; Brun, Luc

2009-10-01

We present a method for the estimation of various features of the tissue micro-architecture using the diffusion magnetic resonance imaging. The considered features are designed from the displacement probability density function (PDF). The estimation is based on two steps: first the approximation of the signal by a series expansion made of Gaussian-Laguerre and Spherical Harmonics functions; followed by a projection on a finite dimensional space. Besides, we propose to tackle the problem of the robustness to Rician noise corrupting in-vivo acquisitions. Our feature estimation is expressed as a variational minimization process leading to a variational framework which is robust to noise. This approach is very flexible regarding the number of samples and enables the computation of a large set of various features of the local tissues structure. We demonstrate the effectiveness of the method with results on both synthetic phantom and real MR datasets acquired in a clinical time-frame.

The Internet as a source of health information among Singaporeans: prevalence, patterns of health surfing and impact on health behaviour.

PubMed

Siow, T R; Soh, I P; Sreedharan, S; Das De, S; Tan, P P; Seow, A; Lun, K C

2003-11-01

The Internet is an increasingly popular source of healthcare information. This study describes the prevalence of health surfers in Singapore and their health-surfing patterns. It also assesses their confidence in online health information and the impact the Internet has on health-seeking behaviour. A cross-sectional survey using a standardised questionnaire was carried out among residents aged 13 to 55 years in 1852 units in Bishan North. These units were selected by single-stage simple random cluster sampling method. The household response rate was 51% (n = 950) and the individual response rate was 69% (n = 1646). Responding and non-responding households were similar in terms of ethnicity and housing type. Of the responders, 62.9% surfed the Internet and 37.7% have surfed for health information. Health surfers tended to be younger (20 to 39 years) and have higher education status. Indians were also more likely than other ethnic groups to surf for health. Professional health-related sites comprised the majority (68%) of sites visited, and the most common search keywords concern chronic degenerative diseases, e.g. hypertension. The top preferred sources of health information were doctors (25.9%), the Internet (25.3%) and the traditional mass media (20.5%). Almost half (45.1%) considered online health information trustworthy if it was from a professional source or if the website displayed the source, while 10.6% trusted the information if it concurred with the doctors' advice. The vast majority (91.7%) had taken some action in response to the information. The Internet is being used as an accessible source of health information by a substantial proportion of the lay public. While this can facilitate greater partnership in healthcare, it underlines the need for doctors to be pro-active in the practice of evidence-based medicine, and for guidelines to enable patients to use this tool in a discerning manner.

Fatal accidents due to train surfing in Berlin.

PubMed

Strauch, H; Wirth, I; Geserick, G

1998-06-08

This study was undertaken for the purpose of analysing under the aspect of legal medicine, fatal accidents due to train surfing in the local transport system of Berlin (S-Bahn and underground). The period of investigation was from 1989 through 1995, with 41 train surfing accidents, among them 18 with fatal outcome. Evaluation included those 14 deaths which were forensically autopsied. It was based on autopsy records of Berlin-based university institutes (Humboldt University and Free University) as well as the Brandenburg State Institute of Legal Medicine. Also used were data obtained from the Berlin Transport Police Record. The casualties were aged between 13 and 25 years, most of them between 16 and 20. The male-female gender ratio was 13:1. Accidents occurred above all in the warmer season of the year, most of them between 20:00 h and midnight. More than 50% of all cases were affected by alcohol, but centrally acting medicaments or other addictive drugs were not noticed at all. Most of the fatal accidents occurred to users of the Berlin S-Bahn network. Older train models were the preferred surfing objects due to their structural peculiarities. Collision with close-to-track obstacles and slipping from the train proved to be the major sources of danger. An analysis of injuries revealed polytraumatisation but for one exception, with craniocerebral injuries being the most common and severest events. The longest survival time amounted to 24 h. As the psychosocial causes of high-risk behaviour of adolescents will hardly be controllable, withdrawal of technical, that is structural design possibilities appears to be the most important approach to prevention of accidents in the future. This demand is met by the new series of the Berlin S-Bahn. The model of the old series, suitable for surfing, still accounts for about 10% of the rolling stock and is to be decommissioned in 1998.

Nearshore circulation on a sea breeze dominated beach during intense wind events

NASA Astrophysics Data System (ADS)

Torres-Freyermuth, Alec; Puleo, Jack A.; DiCosmo, Nick; Allende-Arandía, Ma. Eugenia; Chardón-Maldonado, Patricia; López, José; Figueroa-Espinoza, Bernardo; de Alegria-Arzaburu, Amaia Ruiz; Figlus, Jens; Roberts Briggs, Tiffany M.; de la Roza, Jacobo; Candela, Julio

2017-12-01

A field experiment was conducted on the northern Yucatan coast from April 1 to April 12, 2014 to investigate the role of intense wind events on coastal circulation from the inner shelf to the swash zone. The study area is characterized by a micro-tidal environment, low-energy wave conditions, and a wide and shallow continental shelf. Furthermore, easterly trade winds, local breezes, and synoptic-scale events, associated with the passage of cold-fronts known as Nortes, are ubiquitous in this region. Currents were measured concurrently at different cross-shore locations during both local and synoptic-scale intense wind events to investigate the influence of different forcing mechanisms (i.e., large-scale currents, winds, tides, and waves) on the nearshore circulation. Field observations revealed that nearshore circulation across the shelf is predominantly alongshore-directed (westward) during intense winds. However, the mechanisms responsible for driving instantaneous spatial and temporal current variability depend on the weather conditions and the across-shelf location. During local strong sea breeze events (W > 10 m s-1 from the NE) occurring during spring tide, westward circulation is controlled by the tides, wind, and waves at the inner-shelf, shallow waters, and inside the surf/swash zone, respectively. The nearshore circulation is relaxed during intense land breeze events (W ≈ 9 m s-1 from the SE) associated with the low atmospheric pressure system that preceded a Norte event. During the Norte event (Wmax≈ 15 m s-1 from the NNW), westward circulation dominated outside the surf zone and was correlated to the Yucatan Current, whereas wave breaking forces eastward currents inside the surf/swash zone. The latter finding implies the existence of large alongshore velocity shear at the offshore edge of the surf zone during the Norte event, which enhances mixing between the surf zone and the inner shelf. These findings suggest that both sea breezes and Nortes play an important role in sediment and pollutant transport along/across the nearshore of the Yucatan shelf.

On the Potential of Surfers to Monitor Environmental Indicators in the Coastal Zone.

PubMed

Brewin, Robert J W; de Mora, Lee; Jackson, Thomas; Brewin, Thomas G; Shutler, Jamie

2015-01-01

The social and economic benefits of the coastal zone make it one of the most treasured environments on our planet. Yet it is vulnerable to increasing anthropogenic pressure and climate change. Coastal management aims to mitigate these pressures while augmenting the socio-economic benefits the coastal region has to offer. However, coastal management is challenged by inadequate sampling of key environmental indicators, partly due to issues relating to cost of data collection. Here, we investigate the use of recreational surfers as platforms to improve sampling coverage of environmental indicators in the coastal zone. We equipped a recreational surfer, based in the south west United Kingdom (UK), with a temperature sensor and Global Positioning System (GPS) device that they used when surfing for a period of one year (85 surfing sessions). The temperature sensor was used to derive estimates of sea-surface temperature (SST), an important environmental indicator, and the GPS device used to provide sample location and to extract information on surfer performance. SST data acquired by the surfer were compared with data from an oceanographic station in the south west UK and with satellite observations. Our results demonstrate: (i) high-quality SST data can be acquired by surfers using low cost sensors; and (ii) GPS data can provide information on surfing performance that may help motivate data collection by surfers. Using recent estimates of the UK surfing population, and frequency of surfer participation, we speculate around 40 million measurements on environmental indicators per year could be acquired at the UK coastline by surfers. This quantity of data is likely to enhance coastal monitoring and aid UK coastal management. Considering surfing is a world-wide sport, our results have global implications and the approach could be expanded to other popular marine recreational activities for coastal monitoring of environmental indicators.

On the Potential of Surfers to Monitor Environmental Indicators in the Coastal Zone

PubMed Central

Brewin, Robert J. W.; de Mora, Lee; Jackson, Thomas; Brewin, Thomas G.; Shutler, Jamie

2015-01-01

The social and economic benefits of the coastal zone make it one of the most treasured environments on our planet. Yet it is vulnerable to increasing anthropogenic pressure and climate change. Coastal management aims to mitigate these pressures while augmenting the socio-economic benefits the coastal region has to offer. However, coastal management is challenged by inadequate sampling of key environmental indicators, partly due to issues relating to cost of data collection. Here, we investigate the use of recreational surfers as platforms to improve sampling coverage of environmental indicators in the coastal zone. We equipped a recreational surfer, based in the south west United Kingdom (UK), with a temperature sensor and Global Positioning System (GPS) device that they used when surfing for a period of one year (85 surfing sessions). The temperature sensor was used to derive estimates of sea-surface temperature (SST), an important environmental indicator, and the GPS device used to provide sample location and to extract information on surfer performance. SST data acquired by the surfer were compared with data from an oceanographic station in the south west UK and with satellite observations. Our results demonstrate: (i) high-quality SST data can be acquired by surfers using low cost sensors; and (ii) GPS data can provide information on surfing performance that may help motivate data collection by surfers. Using recent estimates of the UK surfing population, and frequency of surfer participation, we speculate around 40 million measurements on environmental indicators per year could be acquired at the UK coastline by surfers. This quantity of data is likely to enhance coastal monitoring and aid UK coastal management. Considering surfing is a world-wide sport, our results have global implications and the approach could be expanded to other popular marine recreational activities for coastal monitoring of environmental indicators. PMID:26154173

Self-organisation of adsorbed nitrogen on (100) and (410) copper faces: a SPA-LEED study

NASA Astrophysics Data System (ADS)

Sotto, M.; Croset, B.

2000-08-01

The self-organisation of nitrogen nanostructures at different coverages on a (100) copper surface is studied by spot profile analysing low energy electron diffraction (SPA-LEED). The existence of two surface states with a domain of coverage leading to coexistence of the two states as already observed by scanning tunneling microscopy (STM) [Leibsle and Robinson, Phys. Rev. B 47 (1993) 15 865; Leibsle et al., Surf. Sci. 317 (1994) 309; Leibsle, Surf. Sci. 440 (1999) L835] and low energy electron diffraction (LEED) [Sotto et al., Surf. Sci. 371 (1997) 36] is confirmed. In the first state, the surface is organised in square shape islands separated by bare copper <100> rows. This work shows that the surface periodicity depends on the preparation of the nitrogen overlayer. When nitrogen coverage is obtained by adsorption with a sample temperature near 320°C, the periodicity does not vary with coverage and is found to be equal to 55±2 Å. At coverages below 0.75±0.05 and if the nitrogen is deposited at room temperature followed by an anneal at 320°C, during long periods of time, the periodicity evolves to large values (˜97±3 Å). During thermal desorption, the long range order with decreasing coverage is maintained but the surface periodicity also evolves continuously to large values (˜100 Å). However, a surface periodicity of 55±2 Å seems to be a characteristic length of this system. The second surface state corresponds to large c(2×2)N domains separated by <110> trenches [Leibsle and Robinson, Phys. Rev. B 47 (1993) 15 865; Leibsle et al., Surf. Sci. 317 (1994) 309; Leibsle, Surf. Sci. 440 (1999) L835]. Nitrogen adsorption on a (410) stepped face induces a reconstruction into a (810) face with double step height. The complex behaviour of this film growth is discussed in the light of existing theories about the driving force leading to nanostructuration.

An Optimal Mean Based Block Robust Feature Extraction Method to Identify Colorectal Cancer Genes with Integrated Data.

PubMed

Liu, Jian; Cheng, Yuhu; Wang, Xuesong; Zhang, Lin; Liu, Hui

2017-08-17

It is urgent to diagnose colorectal cancer in the early stage. Some feature genes which are important to colorectal cancer development have been identified. However, for the early stage of colorectal cancer, less is known about the identity of specific cancer genes that are associated with advanced clinical stage. In this paper, we conducted a feature extraction method named Optimal Mean based Block Robust Feature Extraction method (OMBRFE) to identify feature genes associated with advanced colorectal cancer in clinical stage by using the integrated colorectal cancer data. Firstly, based on the optimal mean and L 2,1 -norm, a novel feature extraction method called Optimal Mean based Robust Feature Extraction method (OMRFE) is proposed to identify feature genes. Then the OMBRFE method which introduces the block ideology into OMRFE method is put forward to process the colorectal cancer integrated data which includes multiple genomic data: copy number alterations, somatic mutations, methylation expression alteration, as well as gene expression changes. Experimental results demonstrate that the OMBRFE is more effective than previous methods in identifying the feature genes. Moreover, genes identified by OMBRFE are verified to be closely associated with advanced colorectal cancer in clinical stage.

Solar Surfing-Phase I and Solar Surfing - How Close to the Sun Can We Get?

NASA Technical Reports Server (NTRS)

Youngquist, Robert; Nurge, Mark; Williams, Bruce

2017-01-01

The NASA Innovative Advanced Concept (NIAC) program has been funding work at KSC on a novel coating that should allow a future spacecraft to come close to the Sun. The NIAC Symposium will be the last week of September and it is a requirement that the funded material be presented both orally and at a poster session. This DAA submission is requesting approval to go public with both the presentation and the poster.

Importance of Antecedent Beach and Surf-Zone Morphology to Wave Runup Predictions

DTIC Science & Technology

2016-10-01

position on the dune, the laser reflects well off of the water surface when foam is present (blue dots, Figure 1B). Maximum range of measurement...depends upon the amount of breaking and foam present in the surf-zone at any given time, but rarely exceeds 150 m for this laser scanner. Drawbacks to...determined by reverse-shoaling data from the FRF’s 11 m Acoustic Wave and Current (AWAC) profiler to deep water values. Local water levels (tide and surge

A User’s Manual for the Revised Defense Translator Model

DTIC Science & Technology

1990-06-01

22.0 TRANSPORT Of THINGS 631034 23.0 RENT/COHN/UTILITIES 932789 24.0 PRINTING & REPRO 59420 25.0 PAYMENTS PORN NAT’L 1144413 25.0 PUR. INDUSTRIAL FUND...SUPPLIES 0.02103 374 MUSICL INSTRUMENTS & PARTS 0.00111 I 376 OFFICE & ARTISTS’ MATERIALS 0.00481 378 BROOMS,BRUSH, HD SURF FLR. COV. 0.00069 379 MISC...BROOMSBRUSH, HD SURF FLR. COV. 0.00037 379 MISC. MFGING, DURABLE GOODS. 0.06812 380 RAILROADS & RAIL-RELATED SERV. 0.68903 I 381 PASSENGER

Unexploded Ordnance Clearance: A Coordinated Approach to Requirements and Technology Development.

DTIC Science & Technology

1997-03-25

ID #23) Clear mines and obstacles in a 50-meter-wide lane through the surf H N N N N zone and beach in order to land Landing Craft Air Cushion (LCAC...ID #33) Clear the surf zone (SZ) and beach zone (BZ) of mines and H N L N N obstacles in order to land LCAC during amphibious assaults and...Range Clearance All areas Commercial Off The Shelf (COTS) or military adapted -equipment, EOD technicians, DoD civilians, locally hired service

An automatic multi-atlas prostate segmentation in MRI using a multiscale representation and a label fusion strategy

NASA Astrophysics Data System (ADS)

Álvarez, Charlens; Martínez, Fabio; Romero, Eduardo

2015-01-01

The pelvic magnetic Resonance images (MRI) are used in Prostate cancer radiotherapy (RT), a process which is part of the radiation planning. Modern protocols require a manual delineation, a tedious and variable activity that may take about 20 minutes per patient, even for trained experts. That considerable time is an important work ow burden in most radiological services. Automatic or semi-automatic methods might improve the efficiency by decreasing the measure times while conserving the required accuracy. This work presents a fully automatic atlas- based segmentation strategy that selects the more similar templates for a new MRI using a robust multi-scale SURF analysis. Then a new segmentation is achieved by a linear combination of the selected templates, which are previously non-rigidly registered towards the new image. The proposed method shows reliable segmentations, obtaining an average DICE Coefficient of 79%, when comparing with the expert manual segmentation, under a leave-one-out scheme with the training database.

Performance analysis of a multispectral system for mine detection in the littoral zone

NASA Astrophysics Data System (ADS)

Hargrove, John T.; Louchard, Eric

2004-09-01

Science & Technology International (STI) has developed, under contract with the Office of Naval Research, a system of multispectral airborne sensors and processing algorithms capable of detecting mine-like objects in the surf zone. STI has used this system to detect mine-like objects in a littoral environment as part of blind tests at Kaneohe Marine Corps Base Hawaii, and Panama City, Florida. The airborne and ground subsystems are described. The detection algorithm is graphically illustrated. We report on the performance of the system configured to operate without a human in the loop. A subsurface (underwater bottom proud mine in the surf zone and moored mine in shallow water) mine detection capability is demonstrated in the surf zone, and in shallow water with wave spillage and foam. Our analysis demonstrates that this STI-developed multispectral airborne mine detection system provides a technical foundation for a viable mine counter-measures system for use prior to an amphibious assault.

Verification Test of the SURF and SURFplus Models in xRage: Part III Affect of Mesh Alignment

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

Menikoff, Ralph

The previous studies used an underdriven detonation wave in 1-dimension (steady ZND reaction zone profile followed by a scale-invariant rarefaction wave) for PBX 9502 as a verification test of the implementation of the SURF and SURFplus models in the xRage code. Since the SURF rate is a function of the lead shock pressure, the question arises as to the effect on accuracy of variations in the detected shock pressure due to the alignment of the shock front with the mesh. To study the effect of mesh alignment we simulate a cylindrically diverging detonation wave using a planar 2-D mesh. Themore » leading issue is the magnitude of azimuthal asymmetries in the numerical solution. The 2-D test case does not have an exact analytic solution. To quantify the accuracy, the 2-D solution along rays through the origin are compared to a highly resolved 1-D simulation in cylindrical geometry.« less

Fast traffic sign recognition with a rotation invariant binary pattern based feature.

PubMed

Yin, Shouyi; Ouyang, Peng; Liu, Leibo; Guo, Yike; Wei, Shaojun

2015-01-19

Robust and fast traffic sign recognition is very important but difficult for safe driving assistance systems. This study addresses fast and robust traffic sign recognition to enhance driving safety. The proposed method includes three stages. First, a typical Hough transformation is adopted to implement coarse-grained location of the candidate regions of traffic signs. Second, a RIBP (Rotation Invariant Binary Pattern) based feature in the affine and Gaussian space is proposed to reduce the time of traffic sign detection and achieve robust traffic sign detection in terms of scale, rotation, and illumination. Third, the techniques of ANN (Artificial Neutral Network) based feature dimension reduction and classification are designed to reduce the traffic sign recognition time. Compared with the current work, the experimental results in the public datasets show that this work achieves robustness in traffic sign recognition with comparable recognition accuracy and faster processing speed, including training speed and recognition speed.

Fast Traffic Sign Recognition with a Rotation Invariant Binary Pattern Based Feature

PubMed Central

Yin, Shouyi; Ouyang, Peng; Liu, Leibo; Guo, Yike; Wei, Shaojun

2015-01-01

Robust and fast traffic sign recognition is very important but difficult for safe driving assistance systems. This study addresses fast and robust traffic sign recognition to enhance driving safety. The proposed method includes three stages. First, a typical Hough transformation is adopted to implement coarse-grained location of the candidate regions of traffic signs. Second, a RIBP (Rotation Invariant Binary Pattern) based feature in the affine and Gaussian space is proposed to reduce the time of traffic sign detection and achieve robust traffic sign detection in terms of scale, rotation, and illumination. Third, the techniques of ANN (Artificial Neutral Network) based feature dimension reduction and classification are designed to reduce the traffic sign recognition time. Compared with the current work, the experimental results in the public datasets show that this work achieves robustness in traffic sign recognition with comparable recognition accuracy and faster processing speed, including training speed and recognition speed. PMID:25608217

Discovery of 5R-lipoxygenase activity in oocytes of the surf clam, Spisula solidissima.

PubMed

Hada, T; Swift, L L; Brash, A R

1997-06-02

Arachidonic acid and 5-hydroxyeicosatetraenoic acid (5-HETE) are reported to induce reinitiation of meiosis in oocytes of the surf clam Spisula sachalinensis from the Sea of Japan (Varaksin et al., Comp. Biochem. Physiol. 101C, 627-630 (1992). As the Atlantic surf clam Spisula solidissima is a commonly used model for the study of meiosis reinitiation, we examined these cells for the possible occurrence of lipoxygenases and for the bioactivity of the products. Incubation of [14C]arachidonic acid with homogenates of S. solidissima oocytes led to the formation of two major metabolites: 5R-HETE, a novel lipoxygenase product, and 8R-HETE. The products were identified by HPLC, uv spectroscopy, and GC-MS. The corresponding hydroperoxy fatty acids, the primary lipoxygenase products, were isolated from incubations of ammonium sulfate fractionated oocyte cytosol. Arachidonic and eicosapentaenoic acids were identified as constituents of S. solidissima oocyte lipids and the free acids were equally good lipoxygenase substrates. We examined the activity of C18 and C20 polyunsaturated fatty acids and their lipoxygenase products on meiosis reinitiation in Spisula solidissima oocytes, using serotonin and ionophore A23187 as positive controls. The fatty acids and their derivatives were inactive. We conclude that in the surf clam, (as in starfish), there are responding and non-responding species in regard to the maturation-inducing activity of the oocyte lipoxygenase products, and that the lipoxygenase has another, as yet uncharacterized, function in oocyte physiology.

The effects of exposure in sandy beach surf zones on larval fishes.

PubMed

Pattrick, P; Strydom, N A

2014-05-01

The influence of wind and wave exposure on larval fish assemblages within a large bay system was investigated. Larval fishes were sampled from two areas with vastly different exposure to waves and wind, namely the windward and leeward sectors of Algoa Bay. In total, 5702 larval fishes were collected using a modified larval seine. Of these, 4391 were collected in the leeward and 1311 in the windward sector of the bay, representing a total of 23 families and 57 species. Dominant fish families included Clinidae, Engraulidae, Kyphosidae, Mugilidae, Soleidae and Sparidae, similar to the situation elsewhere, highlighting continuity in the composition of larval fish assemblages and the utilization of surf zones by a specific group of larval fishes. Nineteen estuary-associated marine species occurred within the surf zones of Algoa Bay and dominated catches (86·7%) in terms of abundance. Postflexion larvae comprised > 80% of the catch, indicating the importance of the seemingly inhospitable surf zone environment for the early life stages of many fish species. The greatest species diversity was observed within the windward sector of the bay. Distance-based linear modelling identified wave period as the environmental variable explaining the largest proportion of the significant variation in the larval fish assemblage. The physical disturbance generated by breaking waves could create a suitable environment for fish larvae, sheltered from predators and with an abundance of food resources. © 2014 The Fisheries Society of the British Isles.

Robust image features: concentric contrasting circles and their image extraction

NASA Astrophysics Data System (ADS)

Gatrell, Lance B.; Hoff, William A.; Sklair, Cheryl W.

1992-03-01

Many computer vision tasks can be simplified if special image features are placed on the objects to be recognized. A review of special image features that have been used in the past is given and then a new image feature, the concentric contrasting circle, is presented. The concentric contrasting circle image feature has the advantages of being easily manufactured, easily extracted from the image, robust extraction (true targets are found, while few false targets are found), it is a passive feature, and its centroid is completely invariant to the three translational and one rotational degrees of freedom and nearly invariant to the remaining two rotational degrees of freedom. There are several examples of existing parallel implementations which perform most of the extraction work. Extraction robustness was measured by recording the probability of correct detection and the false alarm rate in a set of images of scenes containing mockups of satellites, fluid couplings, and electrical components. A typical application of concentric contrasting circle features is to place them on modeled objects for monocular pose estimation or object identification. This feature is demonstrated on a visually challenging background of a specular but wrinkled surface similar to a multilayered insulation spacecraft thermal blanket.

Coding visual features extracted from video sequences.

PubMed

Baroffio, Luca; Cesana, Matteo; Redondi, Alessandro; Tagliasacchi, Marco; Tubaro, Stefano

2014-05-01

Visual features are successfully exploited in several applications (e.g., visual search, object recognition and tracking, etc.) due to their ability to efficiently represent image content. Several visual analysis tasks require features to be transmitted over a bandwidth-limited network, thus calling for coding techniques to reduce the required bit budget, while attaining a target level of efficiency. In this paper, we propose, for the first time, a coding architecture designed for local features (e.g., SIFT, SURF) extracted from video sequences. To achieve high coding efficiency, we exploit both spatial and temporal redundancy by means of intraframe and interframe coding modes. In addition, we propose a coding mode decision based on rate-distortion optimization. The proposed coding scheme can be conveniently adopted to implement the analyze-then-compress (ATC) paradigm in the context of visual sensor networks. That is, sets of visual features are extracted from video frames, encoded at remote nodes, and finally transmitted to a central controller that performs visual analysis. This is in contrast to the traditional compress-then-analyze (CTA) paradigm, in which video sequences acquired at a node are compressed and then sent to a central unit for further processing. In this paper, we compare these coding paradigms using metrics that are routinely adopted to evaluate the suitability of visual features in the context of content-based retrieval, object recognition, and tracking. Experimental results demonstrate that, thanks to the significant coding gains achieved by the proposed coding scheme, ATC outperforms CTA with respect to all evaluation metrics.

A novel feature extraction approach for microarray data based on multi-algorithm fusion

PubMed Central

Jiang, Zhu; Xu, Rong

2015-01-01

Feature extraction is one of the most important and effective method to reduce dimension in data mining, with emerging of high dimensional data such as microarray gene expression data. Feature extraction for gene selection, mainly serves two purposes. One is to identify certain disease-related genes. The other is to find a compact set of discriminative genes to build a pattern classifier with reduced complexity and improved generalization capabilities. Depending on the purpose of gene selection, two types of feature extraction algorithms including ranking-based feature extraction and set-based feature extraction are employed in microarray gene expression data analysis. In ranking-based feature extraction, features are evaluated on an individual basis, without considering inter-relationship between features in general, while set-based feature extraction evaluates features based on their role in a feature set by taking into account dependency between features. Just as learning methods, feature extraction has a problem in its generalization ability, which is robustness. However, the issue of robustness is often overlooked in feature extraction. In order to improve the accuracy and robustness of feature extraction for microarray data, a novel approach based on multi-algorithm fusion is proposed. By fusing different types of feature extraction algorithms to select the feature from the samples set, the proposed approach is able to improve feature extraction performance. The new approach is tested against gene expression dataset including Colon cancer data, CNS data, DLBCL data, and Leukemia data. The testing results show that the performance of this algorithm is better than existing solutions. PMID:25780277

A novel feature extraction approach for microarray data based on multi-algorithm fusion.

PubMed

Jiang, Zhu; Xu, Rong

2015-01-01

Feature extraction is one of the most important and effective method to reduce dimension in data mining, with emerging of high dimensional data such as microarray gene expression data. Feature extraction for gene selection, mainly serves two purposes. One is to identify certain disease-related genes. The other is to find a compact set of discriminative genes to build a pattern classifier with reduced complexity and improved generalization capabilities. Depending on the purpose of gene selection, two types of feature extraction algorithms including ranking-based feature extraction and set-based feature extraction are employed in microarray gene expression data analysis. In ranking-based feature extraction, features are evaluated on an individual basis, without considering inter-relationship between features in general, while set-based feature extraction evaluates features based on their role in a feature set by taking into account dependency between features. Just as learning methods, feature extraction has a problem in its generalization ability, which is robustness. However, the issue of robustness is often overlooked in feature extraction. In order to improve the accuracy and robustness of feature extraction for microarray data, a novel approach based on multi-algorithm fusion is proposed. By fusing different types of feature extraction algorithms to select the feature from the samples set, the proposed approach is able to improve feature extraction performance. The new approach is tested against gene expression dataset including Colon cancer data, CNS data, DLBCL data, and Leukemia data. The testing results show that the performance of this algorithm is better than existing solutions.

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

Fried, D; Meier, J; Mawlawi, O

Purpose: Use a NEMA-IEC PET phantom to assess the robustness of FDG-PET-based radiomics features to changes in reconstruction parameters across different scanners. Methods: We scanned a NEMA-IEC PET phantom on 3 different scanners (GE Discovery VCT, GE Discovery 710, and Siemens mCT) using a FDG source-to-background ratio of 10:1. Images were retrospectively reconstructed using different iterations (2–3), subsets (21–24), Gaussian filter widths (2, 4, 6mm), and matrix sizes (128,192,256). The 710 and mCT used time-of-flight and point-spread-functions in reconstruction. The axial-image through the center of the 6 active spheres was used for analysis. A region-of-interest containing all spheres was ablemore » to simulate a heterogeneous lesion due to partial volume effects. Maximum voxel deviations from all retrospectively reconstructed images (18 per scanner) was compared to our standard clinical protocol. PET Images from 195 non-small cell lung cancer patients were used to compare feature variation. The ratio of a feature’s standard deviation from the patient cohort versus the phantom images was calculated to assess for feature robustness. Results: Across all images, the percentage of voxels differing by <1SUV and <2SUV ranged from 61–92% and 88–99%, respectively. Voxel-voxel similarity decreased when using higher resolution image matrices (192/256 versus 128) and was comparable across scanners. Taking the ratio of patient and phantom feature standard deviation was able to identify features that were not robust to changes in reconstruction parameters (e.g. co-occurrence correlation). Metrics found to be reasonably robust (standard deviation ratios > 3) were observed for routinely used SUV metrics (e.g. SUVmean and SUVmax) as well as some radiomics features (e.g. co-occurrence contrast, co-occurrence energy, standard deviation, and uniformity). Similar standard deviation ratios were observed across scanners. Conclusions: Our method enabled a comparison of feature variability across scanners and was able to identify features that were not robust to changes in reconstruction parameters.« less

A Temporal and Spatial Analysis of Wave-Generated Foam Patterns in the Surf Zone

DTIC Science & Technology

2017-01-10

region, rectange B depicts the gap region, rectangle C is the plunging breaker, circle D represents a foam hole, rectangle E depict a top box...structures: The hidden skeleton of fluid flows . Phys. Today, 66, 41–47. 35 V. CONCLUSION Unique surf zone imagery, acquired from a UAV at Sand City...MacMahan, J. H., E . B . Thornton, T. P. Stanton, and A. J. H. M. Reniers, 2005: RIPEX: Observations of a rip current system. Mar. Geol., 218, 113–134

RealSurf - A Tool for the Interactive Visualization of Mathematical Models

NASA Astrophysics Data System (ADS)

Stussak, Christian; Schenzel, Peter

For applications in fine art, architecture and engineering it is often important to visualize and to explore complex mathematical models. In former times there were static models of them collected in museums respectively in mathematical institutes. In order to check their properties for esthetical reasons it could be helpful to explore them interactively in 3D in real time. For the class of implicitly given algebraic surfaces we developed the tool RealSurf. Here we give an introduction to the program and some hints for the design of interesting surfaces.

Space Debris Surfaces - Probability of no penetration versus impact velocity and obliquity

NASA Technical Reports Server (NTRS)

Elfer, N.; Meibaum, R.; Olsen, G.

1992-01-01

A collection of computer codes called Space Debris Surfaces (SD-SURF), have been developed to assist in the design and analysis of space debris protection systems. An SD-SURF analysis will show which obliquities and velocities are most likely to cause a penetration to help the analyst select a shield design best suited to the predominant penetration mechanism. Examples of the interaction between space vehicle geometry, the space debris environment, and the penetration and critical damage ballistic limit surfaces of the shield under consideration are presented.

Wind machines. [aerodynamics of sailwing vehicles

NASA Technical Reports Server (NTRS)

Lissaman, P. B. S.

1973-01-01

The basic elements of the air/water momentum exchange are described by the environment, the potential, the air and water subsystems, the total system, and the rule. Many of these topics have direct analogues in aerogenerator design. Aspects of optimal sail design and of waveless hulls are briefly outlined. A wind driven vehicle capable of moving directly downwind faster than the wind, is reported. The lecture is illustrated with slides and movie clips showing surfing catamarans, land and water versions of the Bauer vehicle, hang gliding, land sailing, and wind surfing.

A robust dataset-agnostic heart disease classifier from Phonocardiogram.

PubMed

Banerjee, Rohan; Dutta Choudhury, Anirban; Deshpande, Parijat; Bhattacharya, Sakyajit; Pal, Arpan; Mandana, K M

2017-07-01

Automatic classification of normal and abnormal heart sounds is a popular area of research. However, building a robust algorithm unaffected by signal quality and patient demography is a challenge. In this paper we have analysed a wide list of Phonocardiogram (PCG) features in time and frequency domain along with morphological and statistical features to construct a robust and discriminative feature set for dataset-agnostic classification of normal and cardiac patients. The large and open access database, made available in Physionet 2016 challenge was used for feature selection, internal validation and creation of training models. A second dataset of 41 PCG segments, collected using our in-house smart phone based digital stethoscope from an Indian hospital was used for performance evaluation. Our proposed methodology yielded sensitivity and specificity scores of 0.76 and 0.75 respectively on the test dataset in classifying cardiovascular diseases. The methodology also outperformed three popular prior art approaches, when applied on the same dataset.

A Lagrangian analysis of a sudden stratospheric warming - Comparison of a model simulation and LIMS observations

NASA Technical Reports Server (NTRS)

Pierce, R. B.; Remsberg, Ellis E.; Fairlie, T. D.; Blackshear, W. T.; Grose, William L.; Turner, Richard E.

1992-01-01

Lagrangian area diagnostics and trajectory techniques are used to investigate the radiative and dynamical characteristics of a spontaneous sudden warming which occurred during a 2-yr Langley Research Center model simulation. The ability of the Langley Research Center GCM to simulate the major features of the stratospheric circulation during such highly disturbed periods is illustrated by comparison of the simulated warming to the observed circulation during the LIMS observation period. The apparent sink of vortex area associated with Rossby wave-breaking accounts for the majority of the reduction of the size of the vortex and also acts to offset the radiatively driven increase in the area occupied by the 'surf zone'. Trajectory analysis of selected material lines substantiates the conclusions from the area diagnostics.

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

Menikoff, Ralph

SURFplus is a reactive burn model for high explosives aimed at modelling shock initiation and propagation of detonation waves. It utilizes the SURF model for the fast hot-spot reaction plus a slow reaction for the energy released by carbon clustering. A feature of the SURF model is that there is a partially decoupling between burn rate parameters and detonation wave properties. Previously, parameters for PBX 9502 that control shock ini- tiation had been calibrated to Pop plot data (distance-of-run to detonation as a function of shock pressure initiating the detonation). Here burn rate parameters for the high pres- sure regimemore » are adjusted to t the failure diameter and the limiting detonation speed just above the failure diameter. Simulated results are shown for an uncon ned rate stick when the 9502 diameter is slightly above and slightly below the failure diameter. Just above the failure diameter, in the rest frame of the detonation wave, the front is sonic at the PBX/air interface. As a consequence, the lead shock in the neighborhood of the interface is supported by the detonation pressure in the interior of the explosive rather than the reaction immediately behind the front. In the interior, the sonic point occurs near the end of the fast hot-spot reaction. Consequently, the slow carbon clustering reaction can not a ect the failure diameter. Below the failure diameter, the radial extent of the detonation front decreases starting from the PBX/air interface. That is, the failure starts at the PBX boundary and propagates inward to the axis of the rate stick.« less

Low-grazing angle laser scans of foreshore topography, swash and inner surf-zone wave heights, and mean water level: validation and storm response

NASA Astrophysics Data System (ADS)

Brodie, K. L.; McNinch, J. E.; Forte, M.; Slocum, R.

2010-12-01

Accurately predicting beach evolution during storms requires models that correctly parameterize wave runup and inner surf-zone processes, the principle drivers of sediment exchange between the beach and surf-zone. Previous studies that aimed at measuring wave runup and swash zone water levels have been restricted to analyzing water-elevation time series of (1) the shoreward-most swash excursion using video imaging or near-bed resistance wires, or (2) the free water surface at a particular location on the foreshore using pressure sensors. These data are often compared with wave forcing parameters in deeper water as well as with beach topography observed at finite intervals throughout the time series to identify links between foreshore evolution, wave spectra, and water level variations. These approaches have lead to numerous parameterizations and empirical equations for wave runup but have difficulty providing adequate data to quantify and understand short-term spatial and temporal variations in foreshore evolution. As a result, modeling shoreline response and changes in sub-aerial beach volume during storms remains a substantial challenge. Here, we demonstrate a novel technique in which a terrestrial laser scanner is used to continuously measure beach and foreshore topography as well as water elevation (and wave height) in the swash and inner surf-zone during storms. The terrestrial laser scanner is mounted 2-m above the dune crest at the Field Research Facility in Duck, NC in line with cross-shore wave gauges located at 2-m, 3-m, 5-m, 6-m, and 8-m of water depth. The laser is automated to collect hourly, two-dimensional, 20-minute time series of data along a narrow swath in addition to an hourly three-dimensional laser scan of beach and dune topography +/- 250m alongshore from the laser. Low grazing-angle laser scans are found to reflect off of the surface of the water, providing spatially (e.g. dx <= 0.1 m) and temporally (e.g. dt = 3Hz) dense elevation data of the foreshore, swash, and inner-surf zone bore heights. Foreshore elevation precision is observed to be < 0.01m. Sea surface elevation data is confined to the breaking region and is more extensive in rough, fully-dissipative surf zones, with the fronts of breaking waves and dissipated bores resolved most clearly. Time series of swash front (runup) data will be compared with simultaneously collected video-imaged swash timestacks, and wave height data of the inner surf zone will be compared with wave data from an aquadopp in 2m of water depth. In addition, analysis of the water level time series data at 10 cm intervals across the profile enables reconstruction of the shoreline setup profile as well as cross-shore variations in 1D wave spectra. Foreshore beach morphology evolution is analyzed using both the 2D cross-shore profile data, as well as the 3D topographic data during multiple storm events. Potential sources of error in the measurements, such as shadowing of the wave troughs or reflectance off of wave spray is identified and quantified.

Robust tumor morphometry in multispectral fluorescence microscopy

NASA Astrophysics Data System (ADS)

Tabesh, Ali; Vengrenyuk, Yevgen; Teverovskiy, Mikhail; Khan, Faisal M.; Sapir, Marina; Powell, Douglas; Mesa-Tejada, Ricardo; Donovan, Michael J.; Fernandez, Gerardo

2009-02-01

Morphological and architectural characteristics of primary tissue compartments, such as epithelial nuclei (EN) and cytoplasm, provide important cues for cancer diagnosis, prognosis, and therapeutic response prediction. We propose two feature sets for the robust quantification of these characteristics in multiplex immunofluorescence (IF) microscopy images of prostate biopsy specimens. To enable feature extraction, EN and cytoplasm regions were first segmented from the IF images. Then, feature sets consisting of the characteristics of the minimum spanning tree (MST) connecting the EN and the fractal dimension (FD) of gland boundaries were obtained from the segmented compartments. We demonstrated the utility of the proposed features in prostate cancer recurrence prediction on a multi-institution cohort of 1027 patients. Univariate analysis revealed that both FD and one of the MST features were highly effective for predicting cancer recurrence (p <= 0.0001). In multivariate analysis, an MST feature was selected for a model incorporating clinical and image features. The model achieved a concordance index (CI) of 0.73 on the validation set, which was significantly higher than the CI of 0.69 for the standard multivariate model based solely on clinical features currently used in clinical practice (p < 0.0001). The contributions of this work are twofold. First, it is the first demonstration of the utility of the proposed features in morphometric analysis of IF images. Second, this is the largest scale study of the efficacy and robustness of the proposed features in prostate cancer prognosis.

Geometrically robust image watermarking by sector-shaped partitioning of geometric-invariant regions.

PubMed

Tian, Huawei; Zhao, Yao; Ni, Rongrong; Cao, Gang

2009-11-23

In a feature-based geometrically robust watermarking system, it is a challenging task to detect geometric-invariant regions (GIRs) which can survive a broad range of image processing operations. Instead of commonly used Harris detector or Mexican hat wavelet method, a more robust corner detector named multi-scale curvature product (MSCP) is adopted to extract salient features in this paper. Based on such features, disk-like GIRs are found, which consists of three steps. First, robust edge contours are extracted. Then, MSCP is utilized to detect the centers for GIRs. Third, the characteristic scale selection is performed to calculate the radius of each GIR. A novel sector-shaped partitioning method for the GIRs is designed, which can divide a GIR into several sector discs with the help of the most important corner (MIC). The watermark message is then embedded bit by bit in each sector by using Quantization Index Modulation (QIM). The GIRs and the divided sector discs are invariant to geometric transforms, so the watermarking method inherently has high robustness against geometric attacks. Experimental results show that the scheme has a better robustness against various image processing operations including common processing attacks, affine transforms, cropping, and random bending attack (RBA) than the previous approaches.

Content-based audio authentication using a hierarchical patchwork watermark embedding

NASA Astrophysics Data System (ADS)

Gulbis, Michael; Müller, Erika

2010-05-01

Content-based audio authentication watermarking techniques extract perceptual relevant audio features, which are robustly embedded into the audio file to protect. Manipulations of the audio file are detected on the basis of changes between the original embedded feature information and the anew extracted features during verification. The main challenges of content-based watermarking are on the one hand the identification of a suitable audio feature to distinguish between content preserving and malicious manipulations. On the other hand the development of a watermark, which is robust against content preserving modifications and able to carry the whole authentication information. The payload requirements are significantly higher compared to transaction watermarking or copyright protection. Finally, the watermark embedding should not influence the feature extraction to avoid false alarms. Current systems still lack a sufficient alignment of watermarking algorithm and feature extraction. In previous work we developed a content-based audio authentication watermarking approach. The feature is based on changes in DCT domain over time. A patchwork algorithm based watermark was used to embed multiple one bit watermarks. The embedding process uses the feature domain without inflicting distortions to the feature. The watermark payload is limited by the feature extraction, more precisely the critical bands. The payload is inverse proportional to segment duration of the audio file segmentation. Transparency behavior was analyzed in dependence of segment size and thus the watermark payload. At a segment duration of about 20 ms the transparency shows an optimum (measured in units of Objective Difference Grade). Transparency and/or robustness are fast decreased for working points beyond this area. Therefore, these working points are unsuitable to gain further payload, needed for the embedding of the whole authentication information. In this paper we present a hierarchical extension of the watermark method to overcome the limitations given by the feature extraction. The approach is a recursive application of the patchwork algorithm onto its own patches, with a modified patch selection to ensure a better signal to noise ratio for the watermark embedding. The robustness evaluation was done by compression (mp3, ogg, aac), normalization, and several attacks of the stirmark benchmark for audio suite. Compared on the base of same payload and transparency the hierarchical approach shows improved robustness.

Observation of wave celerity evolution in the nearshore using digital video imagery

NASA Astrophysics Data System (ADS)

Yoo, J.; Fritz, H. M.; Haas, K. A.; Work, P. A.; Barnes, C. F.; Cho, Y.

2008-12-01

Celerity of incident waves in the nearshore is observed from oblique video imagery collected at Myrtle Beach, S.C.. The video camera covers the field view of length scales O(100) m. Celerity of waves propagating in shallow water including the surf zone is estimated by applying advanced image processing and analysis methods to the individual video images sampled at 3 Hz. Original image sequences are processed through video image frame differencing, directional low-pass image filtering to reduce the noise arising from foam in the surf zone. The breaking wave celerity is computed along a cross-shore transect from the wave crest tracks extracted by a Radon transform-based line detection method. The observed celerity from the nearshore video imagery is larger than the linear wave celerity computed from the measured water depths over the entire surf zone. Compared to the nonlinear shallow water wave equation (NSWE)-based celerity computed using the measured depths and wave heights, in general, the video-based celerity shows good agreements over the surf zone except the regions across the incipient wave breaking locations. In the regions across the breaker points, the observed wave celerity is even larger than the NSWE-based celerity due to the transition of wave crest shapes. The observed celerity using the video imagery can be used to monitor the nearshore geometry through depth inversion based on the nonlinear wave celerity theories. For this purpose, the exceeding celerity across the breaker points needs to be corrected accordingly compared to a nonlinear wave celerity theory applied.

Effects of beach morphology and waves on onshore larval transport

NASA Astrophysics Data System (ADS)

Fujimura, A.; Reniers, A.; Paris, C. B.; Shanks, A.; MacMahan, J.; Morgan, S.

2015-12-01

Larvae of intertidal species grow offshore, and migrate back to the shore when they are ready to settle on their adult substrates. In order to reach the habitat, they must cross the surf zone, which is characterized as a semi-permeable barrier. This is accomplished through physical forcing (i.e., waves and current) as well as their own behavior. Two possible scenarios of onshore larval transport are proposed: Negatively buoyant larvae stay in the bottom boundary layer because of turbulence-dependent sinking behavior, and are carried toward the shore by streaming of the bottom boundary layer; positively buoyant larvae move to the shore during onshore wind events, and sink to the bottom once they encounter high turbulence (i.e., surf zone edge), where they are carried by the bottom current toward the shore (Fujimura et al. 2014). Our biophysical Lagrangian particle tracking model helps to explain how beach morphology and wave conditions affect larval distribution patterns and abundance. Model results and field observations show that larval abundance in the surf zone is higher at mildly sloped, rip-channeled beaches than at steep pocket beaches. Beach attributes are broken up to examine which and how beach configuration factors affect larval abundance. Modeling with alongshore uniform beaches with variable slopes reveal that larval populations in the surf zone are negatively correlated with beach steepness. Alongshore variability enhances onshore larval transport because of increased cross-shore water exchange by rip currents. Wave groups produce transient rip currents and enhance cross-shore exchange. Effects of other wave components, such as wave height and breaking wave rollers are also considered.

Prediction and assimilation of surf-zone processes using a Bayesian network: Part I: Forward models

USGS Publications Warehouse

Plant, Nathaniel G.; Holland, K. Todd

2011-01-01

Prediction of coastal processes, including waves, currents, and sediment transport, can be obtained from a variety of detailed geophysical-process models with many simulations showing significant skill. This capability supports a wide range of research and applied efforts that can benefit from accurate numerical predictions. However, the predictions are only as accurate as the data used to drive the models and, given the large temporal and spatial variability of the surf zone, inaccuracies in data are unavoidable such that useful predictions require corresponding estimates of uncertainty. We demonstrate how a Bayesian-network model can be used to provide accurate predictions of wave-height evolution in the surf zone given very sparse and/or inaccurate boundary-condition data. The approach is based on a formal treatment of a data-assimilation problem that takes advantage of significant reduction of the dimensionality of the model system. We demonstrate that predictions of a detailed geophysical model of the wave evolution are reproduced accurately using a Bayesian approach. In this surf-zone application, forward prediction skill was 83%, and uncertainties in the model inputs were accurately transferred to uncertainty in output variables. We also demonstrate that if modeling uncertainties were not conveyed to the Bayesian network (i.e., perfect data or model were assumed), then overly optimistic prediction uncertainties were computed. More consistent predictions and uncertainties were obtained by including model-parameter errors as a source of input uncertainty. Improved predictions (skill of 90%) were achieved because the Bayesian network simultaneously estimated optimal parameters while predicting wave heights.

Emergent relation between surface vapor conductance and relative humidity profiles yields evaporation rates from weather data.

PubMed

Salvucci, Guido D; Gentine, Pierre

2013-04-16

The ability to predict terrestrial evapotranspiration (E) is limited by the complexity of rate-limiting pathways as water moves through the soil, vegetation (roots, xylem, stomata), canopy air space, and the atmospheric boundary layer. The impossibility of specifying the numerous parameters required to model this process in full spatial detail has necessitated spatially upscaled models that depend on effective parameters such as the surface vapor conductance (C(surf)). C(surf) accounts for the biophysical and hydrological effects on diffusion through the soil and vegetation substrate. This approach, however, requires either site-specific calibration of C(surf) to measured E, or further parameterization based on metrics such as leaf area, senescence state, stomatal conductance, soil texture, soil moisture, and water table depth. Here, we show that this key, rate-limiting, parameter can be estimated from an emergent relationship between the diurnal cycle of the relative humidity profile and E. The relation is that the vertical variance of the relative humidity profile is less than would occur for increased or decreased evaporation rates, suggesting that land-atmosphere feedback processes minimize this variance. It is found to hold over a wide range of climate conditions (arid-humid) and limiting factors (soil moisture, leaf area, energy). With this relation, estimates of E and C(surf) can be obtained globally from widely available meteorological measurements, many of which have been archived since the early 1900s. In conjunction with precipitation and stream flow, long-term E estimates provide insights and empirical constraints on projected accelerations of the hydrologic cycle.

Turbulent stresses in the surf-zone: Which way is up?

USGS Publications Warehouse

Haines, John W.; Gelfenbaum, Guy; Edge, B.L

1997-01-01

Velocity observations from a vertical stack of three-component Acoustic Doppler Velocimeters (ADVs) within the energetic surf-zone are presented. Rapid temporal sampling and small sampling volume provide observations suitable for investigation of the role of turbulent fluctuations in surf-zone dynamics. While sensor performance was good, failure to recover reliable measures of tilt from the vertical compromise the data value. We will present some cursory observations supporting the ADV performance, and examine the sensitivity of stress estimates to uncertainty in the sensor orientation. It is well known that turbulent stress estimates are highly sensitive to orientation relative to vertical when wave motions are dominant. Analyses presented examine the potential to use observed flow-field characteristics to constrain sensor orientation. Results show that such an approach may provide a consistent orientation to a fraction of a degree, but the inherent sensitivity of stress estimates requires a still more restrictive constraint. Regardless, the observations indicate the degree to which stress estimates are dependent on orientation, and provide some indication of the temporal variability in time-averaged stress estimates.

A model for the generation of two-dimensional surf beat

USGS Publications Warehouse

List, Jeffrey H.

1992-01-01

A finite difference model predicting group-forced long waves in the nearshore is constructed with two interacting parts: an incident wave model providing time-varying radiation stress gradients across the nearshore, and a long-wave model which solves the equations of motion for the forcing imposed by the incident waves. Both shallow water group-bound long waves and long waves generated by a time-varying breakpoint are simulated. Model-generated time series are used to calculate the cross correlation between wave groups and long waves through the surf zone. The cross-correlation signal first observed by Tucker (1950) is well predicted. For the first time, this signal is decomposed into the contributions from the two mechanisms of leaky mode forcing. Results show that the cross-correlation signal can be explained by bound long waves which are amplified, though strongly modified, through the surf zone before reflection from the shoreline. The breakpoint-forced long waves are added to the bound long waves at a phase of pi/2 and are a secondary contribution owing to their relatively small size.

Verification Test of the SURF and SURFplus Models in xRage: Part II

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

Menikoff, Ralph

2016-06-20

The previous study used an underdriven detonation wave (steady ZND reaction zone profile followed by a scale invariant rarefaction wave) for PBX 9502 as a validation test of the implementation of the SURF and SURFplus models in the xRage code. Even with a fairly fine uniform mesh (12,800 cells for 100mm) the detonation wave profile had limited resolution due to the thin reaction zone width (0.18mm) for the fast SURF burn rate. Here we study the effect of finer resolution by comparing results of simulations with cell sizes of 8, 2 and 1 μm, which corresponds to 25, 100 andmore » 200 points within the reaction zone. With finer resolution the lead shock pressure is closer to the von Neumann spike pressure, and there is less noise in the rarefaction wave due to fluctuations within the reaction zone. As a result the average error decreases. The pointwise error is still dominated by the smearing the pressure kink in the vicinity of the sonic point which occurs at the end of the reaction zone.« less

Phonological Feature Re-Assembly and the Importance of Phonetic Cues

ERIC Educational Resources Information Center

Archibald, John

2009-01-01

It is argued that new phonological features can be acquired in second languages, but that both feature acquisition and feature re-assembly are affected by the robustness of phonetic cues in the input.

Learning deep similarity in fundus photography

NASA Astrophysics Data System (ADS)

Chudzik, Piotr; Al-Diri, Bashir; Caliva, Francesco; Ometto, Giovanni; Hunter, Andrew

2017-02-01

Similarity learning is one of the most fundamental tasks in image analysis. The ability to extract similar images in the medical domain as part of content-based image retrieval (CBIR) systems has been researched for many years. The vast majority of methods used in CBIR systems are based on hand-crafted feature descriptors. The approximation of a similarity mapping for medical images is difficult due to the big variety of pixel-level structures of interest. In fundus photography (FP) analysis, a subtle difference in e.g. lesions and vessels shape and size can result in a different diagnosis. In this work, we demonstrated how to learn a similarity function for image patches derived directly from FP image data without the need of manually designed feature descriptors. We used a convolutional neural network (CNN) with a novel architecture adapted for similarity learning to accomplish this task. Furthermore, we explored and studied multiple CNN architectures. We show that our method can approximate the similarity between FP patches more efficiently and accurately than the state-of- the-art feature descriptors, including SIFT and SURF using a publicly available dataset. Finally, we observe that our approach, which is purely data-driven, learns that features such as vessels calibre and orientation are important discriminative factors, which resembles the way how humans reason about similarity. To the best of authors knowledge, this is the first attempt to approximate a visual similarity mapping in FP.

Multiscale Region-Level VHR Image Change Detection via Sparse Change Descriptor and Robust Discriminative Dictionary Learning

PubMed Central

Xu, Yuan; Ding, Kun; Huo, Chunlei; Zhong, Zisha; Li, Haichang; Pan, Chunhong

2015-01-01

Very high resolution (VHR) image change detection is challenging due to the low discriminative ability of change feature and the difficulty of change decision in utilizing the multilevel contextual information. Most change feature extraction techniques put emphasis on the change degree description (i.e., in what degree the changes have happened), while they ignore the change pattern description (i.e., how the changes changed), which is of equal importance in characterizing the change signatures. Moreover, the simultaneous consideration of the classification robust to the registration noise and the multiscale region-consistent fusion is often neglected in change decision. To overcome such drawbacks, in this paper, a novel VHR image change detection method is proposed based on sparse change descriptor and robust discriminative dictionary learning. Sparse change descriptor combines the change degree component and the change pattern component, which are encoded by the sparse representation error and the morphological profile feature, respectively. Robust change decision is conducted by multiscale region-consistent fusion, which is implemented by the superpixel-level cosparse representation with robust discriminative dictionary and the conditional random field model. Experimental results confirm the effectiveness of the proposed change detection technique. PMID:25918748

High-resolution, vacuum-ultraviolet absorption spectrum of boron trifluoride

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

Hughes, Patrick P.; Thompson, Alan K.; Vest, Robert E.

2014-11-21

In the course of investigations of thermal neutron detection based on mixtures of {sup 10}BF{sub 3} with other gases, knowledge was required of the photoabsorption cross sections of {sup 10}BF{sub 3} for wavelengths between 135 and 205 nm. Large discrepancies in the values reported in existing literature led to the absolute measurements reported in this communication. The measurements were made at the SURF III Synchrotron Ultraviolet Radiation Facility at the National Institute of Standards and Technology. The measured absorption cross sections vary from 10{sup −20} cm{sup 2} at 135 nm to less than 10{sup −21} cm{sup 2} in the regionmore » from 165 to 205 nm. Three previously unreported absorption features with resolvable structure were found in the regions 135–145 nm, 150–165 nm, and 190–205 nm. Quantum mechanical calculations, using the TD-B3LYP/aug-cc-pVDZ variant of time-dependent density functional theory implemented in Gaussian 09, suggest that the observed absorption features arise from symmetry-changing adiabatic transitions.« less

A fully convolutional networks (FCN) based image segmentation algorithm in binocular imaging system

NASA Astrophysics Data System (ADS)

Long, Zourong; Wei, Biao; Feng, Peng; Yu, Pengwei; Liu, Yuanyuan

2018-01-01

This paper proposes an image segmentation algorithm with fully convolutional networks (FCN) in binocular imaging system under various circumstance. Image segmentation is perfectly solved by semantic segmentation. FCN classifies the pixels, so as to achieve the level of image semantic segmentation. Different from the classical convolutional neural networks (CNN), FCN uses convolution layers instead of the fully connected layers. So it can accept image of arbitrary size. In this paper, we combine the convolutional neural network and scale invariant feature matching to solve the problem of visual positioning under different scenarios. All high-resolution images are captured with our calibrated binocular imaging system and several groups of test data are collected to verify this method. The experimental results show that the binocular images are effectively segmented without over-segmentation. With these segmented images, feature matching via SURF method is implemented to obtain regional information for further image processing. The final positioning procedure shows that the results are acceptable in the range of 1.4 1.6 m, the distance error is less than 10mm.

Cultural boundary surfing in mental health nursing: a creative narration.

PubMed

Kidd, Jacquie

2010-01-01

In the mental health context, nurses navigate multifaceted boundaries every day in an effort to develop and maintain the therapeutic relationship; an endeavour that is breathtaking in its complexity. In this paper, I adopt an unconventional form of writing to explore the individual nature of cultural boundaries, and uncover hidden messages that impact on our efforts to build connections across cultures and ethnicities in mental health settings. Presented as a play, the conversation between protagonists explores cultural competence alongside the notion of 'discovery', and the potential of the Tidal Model to provide a vehicle for successful cultural boundary surfing.

Surfing surface gravity waves

NASA Astrophysics Data System (ADS)

Pizzo, Nick

2017-11-01

A simple criterion for water particles to surf an underlying surface gravity wave is presented. It is found that particles travelling near the phase speed of the wave, in a geometrically confined region on the forward face of the crest, increase in speed. The criterion is derived using the equation of John (Commun. Pure Appl. Maths, vol. 6, 1953, pp. 497-503) for the motion of a zero-stress free surface under the action of gravity. As an example, a breaking water wave is theoretically and numerically examined. Implications for upper-ocean processes, for both shallow- and deep-water waves, are discussed.

Adventure and Extreme Sports.

PubMed

Gomez, Andrew Thomas; Rao, Ashwin

2016-03-01

Adventure and extreme sports often involve unpredictable and inhospitable environments, high velocities, and stunts. These activities vary widely and include sports like BASE jumping, snowboarding, kayaking, and surfing. Increasing interest and participation in adventure and extreme sports warrants understanding by clinicians to facilitate prevention, identification, and treatment of injuries unique to each sport. This article covers alpine skiing and snowboarding, skateboarding, surfing, bungee jumping, BASE jumping, and whitewater sports with emphasis on epidemiology, demographics, general injury mechanisms, specific injuries, chronic injuries, fatality data, and prevention. Overall, most injuries are related to overuse, trauma, and environmental or microbial exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

Generalized Sheet Transition Condition FDTD Simulation of Metasurface

NASA Astrophysics Data System (ADS)

Vahabzadeh, Yousef; Chamanara, Nima; Caloz, Christophe

2018-01-01

We propose an FDTD scheme based on Generalized Sheet Transition Conditions (GSTCs) for the simulation of polychromatic, nonlinear and space-time varying metasurfaces. This scheme consists in placing the metasurface at virtual nodal plane introduced between regular nodes of the staggered Yee grid and inserting fields determined by GSTCs in this plane in the standard FDTD algorithm. The resulting update equations are an elegant generalization of the standard FDTD equations. Indeed, in the limiting case of a null surface susceptibility ($\\chi_\\text{surf}=0$), they reduce to the latter, while in the next limiting case of a time-invariant metasurface $[\\chi_\\text{surf}\

Robust evaluation of time series classification algorithms for structural health monitoring

NASA Astrophysics Data System (ADS)

Harvey, Dustin Y.; Worden, Keith; Todd, Michael D.

2014-03-01

Structural health monitoring (SHM) systems provide real-time damage and performance information for civil, aerospace, and mechanical infrastructure through analysis of structural response measurements. The supervised learning methodology for data-driven SHM involves computation of low-dimensional, damage-sensitive features from raw measurement data that are then used in conjunction with machine learning algorithms to detect, classify, and quantify damage states. However, these systems often suffer from performance degradation in real-world applications due to varying operational and environmental conditions. Probabilistic approaches to robust SHM system design suffer from incomplete knowledge of all conditions a system will experience over its lifetime. Info-gap decision theory enables nonprobabilistic evaluation of the robustness of competing models and systems in a variety of decision making applications. Previous work employed info-gap models to handle feature uncertainty when selecting various components of a supervised learning system, namely features from a pre-selected family and classifiers. In this work, the info-gap framework is extended to robust feature design and classifier selection for general time series classification through an efficient, interval arithmetic implementation of an info-gap data model. Experimental results are presented for a damage type classification problem on a ball bearing in a rotating machine. The info-gap framework in conjunction with an evolutionary feature design system allows for fully automated design of a time series classifier to meet performance requirements under maximum allowable uncertainty.

A Self-Adaptive Dynamic Recognition Model for Fatigue Driving Based on Multi-Source Information and Two Levels of Fusion

PubMed Central

Sun, Wei; Zhang, Xiaorui; Peeta, Srinivas; He, Xiaozheng; Li, Yongfu; Zhu, Senlai

2015-01-01

To improve the effectiveness and robustness of fatigue driving recognition, a self-adaptive dynamic recognition model is proposed that incorporates information from multiple sources and involves two sequential levels of fusion, constructed at the feature level and the decision level. Compared with existing models, the proposed model introduces a dynamic basic probability assignment (BPA) to the decision-level fusion such that the weight of each feature source can change dynamically with the real-time fatigue feature measurements. Further, the proposed model can combine the fatigue state at the previous time step in the decision-level fusion to improve the robustness of the fatigue driving recognition. An improved correction strategy of the BPA is also proposed to accommodate the decision conflict caused by external disturbances. Results from field experiments demonstrate that the effectiveness and robustness of the proposed model are better than those of models based on a single fatigue feature and/or single-source information fusion, especially when the most effective fatigue features are used in the proposed model. PMID:26393615

The analysis of image feature robustness using cometcloud

PubMed Central

Qi, Xin; Kim, Hyunjoo; Xing, Fuyong; Parashar, Manish; Foran, David J.; Yang, Lin

2012-01-01

The robustness of image features is a very important consideration in quantitative image analysis. The objective of this paper is to investigate the robustness of a range of image texture features using hematoxylin stained breast tissue microarray slides which are assessed while simulating different imaging challenges including out of focus, changes in magnification and variations in illumination, noise, compression, distortion, and rotation. We employed five texture analysis methods and tested them while introducing all of the challenges listed above. The texture features that were evaluated include co-occurrence matrix, center-symmetric auto-correlation, texture feature coding method, local binary pattern, and texton. Due to the independence of each transformation and texture descriptor, a network structured combination was proposed and deployed on the Rutgers private cloud. The experiments utilized 20 randomly selected tissue microarray cores. All the combinations of the image transformations and deformations are calculated, and the whole feature extraction procedure was completed in 70 minutes using a cloud equipped with 20 nodes. Center-symmetric auto-correlation outperforms all the other four texture descriptors but also requires the longest computational time. It is roughly 10 times slower than local binary pattern and texton. From a speed perspective, both the local binary pattern and texton features provided excellent performance for classification and content-based image retrieval. PMID:23248759

CNN universal machine as classificaton platform: an art-like clustering algorithm.

PubMed

Bálya, David

2003-12-01

Fast and robust classification of feature vectors is a crucial task in a number of real-time systems. A cellular neural/nonlinear network universal machine (CNN-UM) can be very efficient as a feature detector. The next step is to post-process the results for object recognition. This paper shows how a robust classification scheme based on adaptive resonance theory (ART) can be mapped to the CNN-UM. Moreover, this mapping is general enough to include different types of feed-forward neural networks. The designed analogic CNN algorithm is capable of classifying the extracted feature vectors keeping the advantages of the ART networks, such as robust, plastic and fault-tolerant behaviors. An analogic algorithm is presented for unsupervised classification with tunable sensitivity and automatic new class creation. The algorithm is extended for supervised classification. The presented binary feature vector classification is implemented on the existing standard CNN-UM chips for fast classification. The experimental evaluation shows promising performance after 100% accuracy on the training set.

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.

The imbalanced surfing-life of humanity to survival in the global changes

NASA Astrophysics Data System (ADS)

Kontar, V. A.

2013-12-01

We have written many times about the imbalance of Nature as the cause of the global change. Here, we offer some method for the humanity survival in the face of global change of the imbalanced anisotropic real Nature. There are two logics of understanding the real Nature: the traditional balanced, and the new imbalanced. The balanced logic presupposes that Nature is balanced, isotropic, etc. The imbalanced logic presupposes opposite that Nature is imbalanced, anisotropic, etc. Respectively can be two styles of the people life: balanced and imbalanced. The image of the flat earth corresponds well with the balanced lifestyle of people. On the balanced life people spend activities to achieve the balance by reducing the change, stabilization, leveling any level changes, etc. If there is a mountain on the road, it must be align the track or make the tunnel. If there is a ravine on the road, then it need backfilled or to build a bridge. If someone is in restless, it must be calm, etc. As example of the happiness in the balanced life is the stability, balance, and therefore the global changes of Nature are perceived as a catastrophe. In the balanced lifestyle people can easily decide to use force, especially if there is not enough knowledge. But Nature has power which in billions times greater than the forces of humanity. Therefore, humanity will beaten in struggle with Nature and disappear. The imbalanced lifestyle is the fundamentally different. The imbalanced lifestyle complies with the surface of the ocean, which always changes, but sometimes can be and flat. But the flat calm ocean surface is inconvenient for the imbalanced life. You need to pull boat yourself because is no wind in the sails. The anisotropic imbalanced Nature has gradients in all parameters. At a certain level of knowledge and experience, people can use this multi-dimensional gradient essence of the real Nature for human's discretion. The imbalanced life is like a surfing. If properly understood Nature, you can find a route slip through the waves of Nature, which will bring closer the person to the desired goals. Of course, the changeable ocean is much more complicated than a flat surface. The imbalanced logic also is much more complex than the simplified balanced logic. As the calm ocean is like the flat surface, so same the balanced logic solutions are sometimes looks like as the truth, but only in the calm weather. At the normal ocean weather the balanced solutions are incorrect and mislead people. The river can be as image of the imbalanced surfing life. The river starts as small stream and running through all the obstacles to ocean. The water of river is flowing at the bottom of the potential trench of the Earth gravity and the Coriolis acceleration. For the imbalanced surfing life is most important not a steamroller of force, but the knowledge and perseverance in the search for the best path to the desirable goals. The example of happiness in the surfing imbalanced life can be joy from successfully usage the suitable trends of the anisotropic imbalanced real Nature. At the imbalanced surfing life should be the main guide: Nature doesn't have the bad weather. The global changes it is not catastrophe, but the normal state of the real anisotropic imbalanced Nature. Just everybody has to choose the weather which will be good for their personal surfing.

Temporal assessment of radiomic features on clinical mammography in a high-risk population

NASA Astrophysics Data System (ADS)

Mendel, Kayla R.; Li, Hui; Lan, Li; Chan, Chun-Wai; King, Lauren M.; Tayob, Nabihah; Whitman, Gary; El-Zein, Randa; Bedrosian, Isabelle; Giger, Maryellen L.

2018-02-01

Extraction of high-dimensional quantitative data from medical images has become necessary in disease risk assessment, diagnostics and prognostics. Radiomic workflows for mammography typically involve a single medical image for each patient although medical images may exist for multiple imaging exams, especially in screening protocols. Our study takes advantage of the availability of mammograms acquired over multiple years for the prediction of cancer onset. This study included 841 images from 328 patients who developed subsequent mammographic abnormalities, which were confirmed as either cancer (n=173) or non-cancer (n=155) through diagnostic core needle biopsy. Quantitative radiomic analysis was conducted on antecedent FFDMs acquired a year or more prior to diagnostic biopsy. Analysis was limited to the breast contralateral to that in which the abnormality arose. Novel metrics were used to identify robust radiomic features. The most robust features were evaluated in the task of predicting future malignancies on a subset of 72 subjects (23 cancer cases and 49 non-cancer controls) with mammograms over multiple years. Using linear discriminant analysis, the robust radiomic features were merged into predictive signatures by: (i) using features from only the most recent contralateral mammogram, (ii) change in feature values between mammograms, and (iii) ratio of feature values over time, yielding AUCs of 0.57 (SE=0.07), 0.63 (SE=0.06), and 0.66 (SE=0.06), respectively. The AUCs for temporal radiomics (ratio) statistically differed from chance, suggesting that changes in radiomics over time may be critical for risk assessment. Overall, we found that our two-stage process of robustness assessment followed by performance evaluation served well in our investigation on the role of temporal radiomics in risk assessment.

Spatiotemporal associations between Pacific herring spawn and surf scoter spring migration: evaluating a "silver wave" hypothesis

USGS Publications Warehouse

Lok, E.K.; Esler, Daniel N.; Takekawa, John Y.; De La Cruz, S.W.; Boyd, W.S.; Nysewander, D.R.; Evenson, J.R.; Ward, D.H.

2012-01-01

Surf scoters Melanitta perspicillata are sea ducks that aggregate at spawning events of Pacific herring Clupea pallasi and forage on the eggs, which are deposited in abundance during spring at discrete sites. We evaluated whether migrating scoters followed a ‘silver wave’ of resource availability, analogous to the ‘green wave’ of high-quality foraging conditions that herbivorous waterfowl follow during spring migration. We confirmed that herring spawning activity began later in the year at higher latitudes, creating a northward-progressing wave of short-term localized food availability. Using satellite telemetry and aerial surveys, we documented the chronology of scoter spring migration and the use of stopover locations in relation to herring spawn timing and locations. We found that the migration chronology paralleled the northward progression of herring spawning events. Although there was considerable variability in the timing of both scoter migration and the initiation of herring spawning, the processes were related beyond a coincidental northward progression. During migration, 60% of the tracked scoters visited at least 1 spawn site, and those that used spawn sites were located on spawn sites for approximately one-third of their migration locations. Surf scoters showed close spatiotemporal associations with herring spawning events, confirming that the presence of herring spawn was a factor determining habitat use for many individuals. Surf scoters showed close spatiotemporal associations with herring spawning events, confirming that the presence of herring spawn was a factor determining habitat use for many individuals, a conclusion that is consistent with previous studies which used physiologically based metrics to evaluate the importance of herring spawn.

Vertical distribution of phytoplankton communities in open ocean: An assessment based on surface chlorophyll

NASA Astrophysics Data System (ADS)

Uitz, Julia; Claustre, Hervé; Morel, André; Hooker, Stanford B.

2006-08-01

The present study examines the potential of using the near-surface chlorophyll a concentration ([Chla]surf), as it can be derived from ocean color observation, to infer the column-integrated phytoplankton biomass, its vertical distribution, and ultimately the community composition. Within this context, a large High-Performance Liquid Chromatography (HPLC) pigment database was analyzed. It includes 2419 vertical pigment profiles, sampled in case 1 waters with various trophic states (0.03-6 mg Chla m-3). The relationships between [Chla]surf and the chlorophyll a vertical distribution, as previously derived by Morel and Berthon (1989), are fully confirmed. This agreement makes it possible to go further and to examine if similar relationships between [Chla]surf and the phytoplankton assemblage composition along the vertical can be derived. Thanks to the detailed pigment composition, and use of specific pigment biomarkers, the contribution to the local chlorophyll a concentration of three phytoplankton groups can be assessed. With some cautions, these groups coincide with three size classes, i.e., microplankton, nanoplankton and picoplankton. Corroborating previous regional findings (e.g., large species dominate in eutrophic environments, whereas tiny phytoplankton prevail in oligotrophic zones), the present results lead to an empirical parameterization applicable to most oceanic waters. The predictive skill of this parameterization is satisfactorily tested on a separate data set. With such a tool, the vertical chlorophyll a profiles of each group can be inferred solely from the knowledge of [Chla]surf. By combining this tool with satellite ocean color data, it becomes possible to quantify on a global scale the phytoplankton biomass associated with each of the three algal assemblages.

Spatial and temporal variability in surf zone fish assemblages on the coast of northern New Jersey

NASA Astrophysics Data System (ADS)

Wilber, D. H.; Clarke, D. G.; Burlas, M. H.; Ruben, H.; Will, R. J.

2003-02-01

The surf zone fish community along 15 km of northern New Jersey shoreline was sampled every 2 weeks by beach seine in the late summers and early falls of 1995-1999 in conjunction with monitoring of a beach nourishment project. Fifty-seven species representing 30 families were collected during the course of the study. Over 90% of each sampling period's catch was composed of five taxa or less. These taxa included Atlantic and rough silversides, Menidia menidia and Membras martinica, bluefish, Pomatomus saltatrix, and bay and striped anchovies, Anchoa mitchilli and Anchoa hepsetus, with the relative contributions of these taxa varying among years. Both bluefish and anchovy abundances varied by an order of magnitude among years. Size-frequency distributions indicate summer-spawned bluefish recruit to the surf zone habitat as two cohorts in August and October, respectively. Fish abundance and richness were greater at substations closest to rock groins. Taxonomic richness declined along with decreasing water temperature in the fall, but was not correlated with turbidity or tide stage (measured as minutes before or after low tide). The extensive sampling effort undertaken in this study, 2190 seine hauls that captured 295 868 fish, was examined in relation to the number and relative proportions of taxa collected. Species accumulation curves and percent similarity calculations were used to investigate the adequacy of a reduced sampling protocol in characterizing the taxonomic composition of the surf zone fish community. Calculations from eight complete sampling periods (84 seine hauls each) indicate that a reduction in sampling effort by one-half would have yielded on average 75% of the total number of species captured with approximately 85% similarity in relative species composition.

Assessment of surf zone environmental variables in a southwestern Atlantic sandy beach (Monte Hermoso, Argentina).

PubMed

Menéndez, M Clara; Fernández Severini, Melisa D; Buzzi, Natalia S; Piccolo, M Cintia; Perillo, Gerardo M E

2016-08-01

The aim of this study was to investigate the temporal dynamics (monthly/tidal) of water temperature, salinity, chlorophyll-a (chlo-a), suspended particulate matter (SPM), particulate organic carbon (POC), and dissolved nutrients in the surf zone of Monte Hermoso sandy beach, Argentina. We also aimed to understand the underlying mechanisms responsible for the observed variability. Sampling was carried out approximately monthly (September 2009-November 2010), and all samples were collected in a fixed station during high and low tide. Water temperature showed a clear seasonal variability (July: 9 °C-December: 26.5 °C) and a thermal amplitude of 17.5 °C. Salinity ranged from 33 to 37, without a pronounced seasonality. SPM (10-223 mg L(-1)) and POC concentrations (399-6445 mg C m(-3)) were high in surf zone waters. Chlo-a (0.05-9.16 μg L(-1)) was low and did not evidence the occurrence of surf diatom accumulations. Dissolved nutrient concentration was quite fluctuating. None of the variables seemed to be affected by tidal stage. The results showed how fluctuating the physico-chemical and biological variables can be in this particular system. The observed variability can be related with local beach conditions but also with regional processes. The study area is highly influenced by a neighbor estuary and as a consequence, could be vulnerable to their seasonal and inter-annual dynamics. All of these characteristics must be considered for further studies and planning of the uses of natural resources and should be taken into account in any environmental monitoring program conducted in a similar beach system.

Evaluation of a 3% surf solution (surf field mastitis test) for the diagnosis of subclinical bovine and bubaline mastitis.

PubMed

Muhammad, Ghulam; Naureen, Abeera; Asi, Muhammad Nadeem; Saqib, Muhammad; Fazal-ur-Rehman

2010-03-01

To evaluate a 3% solution of household detergent viz., Surf Excel (Surf field mastitis test, SFMT) vis-à-vis California mastitis test (CMT), Whiteside test (WST), somatic cell counts (SCC; cut off limit = 5 x 10(5) cells per millilitre) and bacteriological cultures for the detection of subclinical mastitis in quarter foremilk samples (n=800) of dairy cows and buffaloes. Culture and SCC were used as gold standards. All tests were evaluated parallel and serial patterns. The sensitivities of SFMT, SCC, culture, CMT and WST in parallel testing were 72.82, 81.55, 87.38, 75.73 and 54.37%, respectively in cows, while 66.22, 79.73, 82.43, 70.27 and 50.00, respectively in buffaloes. SFMT was significantly (p<0.05) more sensitive than WST and comparable to CMT in both species. In serial testing, percent specificity of SFMT (87.12 in cow; 85.16 in buffaloes) was significantly (P<0.05) higher than that of CMT (83.33 in cow; 80.64 in buffaloes). The negative predictive values of SFMT (93.50 in cow; 96.35 in buffaloes) differed non-significantly from that of CMT (94.02 in cow; 96.15 in buffaloes). The kappa index between the tests was moderate to perfect both in parallel (0.54 to >0.80) and serial (0.58 to >0.8) testing. On the basis of closely similar diagnostic efficiency of SFMT to CMT in terms of sensitivity, specificity, predictive values and kappa index together with inexpensive and ready availability of SFMT reagent, it tempting to suggest that SFMT can be use as a cheaper, user-friendly alternative animal-side subclinical mastitis diagnostic test in poor countries.

Simultaneous Observations of Beach and Surf-Zone Topography from a sUAS

NASA Astrophysics Data System (ADS)

Slocum, R. K.; Brodie, K. L.; Spore, N.

2016-02-01

Beaches and surf-zones can vary rapidly in time and space, necessitating frequent, spatially extensive observations for up-to-date knowledge on their current condition. Traditional surveying methods are expensive, can be dangerous in large wave conditions, and can lack sufficient spatial density. Existing remote sensing technologies have focused on both active sensing (airborne lidar, X-band radar) or passive sensing (electro-optical or infrared imagery) to either directly measure elevations of the beach and seafloor or exploit the optical signal of refracting and breaking waves in the surf-zone. These methods, however, can be prohibitively expensive for widespread, high temporal frequency use, or lack the spatial coverage required to quantify a large stretch of beach. UAS offer an affordable and accessible alternative, but existing COTS UAS sensor suites are not optimized for generation of bathymetry and topography at the same time. Here, we present a new approach using an inexpensive, custom multi-camera sensor designed with a wide field of view for integration on either a fixed wing of multirotor UAS platform. We introduce a processing methodology and workflow to generate a topographic pointcloud and rectified imagery of the water surface using structure from motion algorithms. The topographic pointcloud data is processed to generate a DSM of the beach and extract morphologic parameters (beach slope, dune toe, etc). Rectified imagery of the water surface is used to quantify sandbar location as well as perform a celerity based bathymetric inversion. Accuracy of this methodology is calculated by comparing processed data to lidar pointclouds, as well as photo identifiable targets on the beach and jetted into the surf zone. Funded by the USACE Military Engineering POD:A&U Program and Coastal Field Data Collection Program.

From Surface Chlorophyll a to Phytoplankton Community Composition in Oceanic Waters

NASA Technical Reports Server (NTRS)

Uitz, Julia; Claustre, Herve; Morel, Andre; Hooker, Stanford B.

2004-01-01

The objective of the present study is to examine the potential of using the near-surface total chlorophyll a concentration (C(sub surf)), as it can be derived from ocean color observation, to infer the column-integrated and the vertical distribution of the phytoplanktonic biomass, both in a quantitative way and in a qualitative way (z.e., in terms of community structure). Within this context, a large HPLC (High Performance Liquid Chromatography) pigment database has been analyzed. It includes 2419 vertical pigment profiles, all sampled in Case-1 waters with various trophic states. The relationshps between C(sub surf) and the total chlorophyll alpha vertical distribution, as previously derived by Morel and Berthon, are fully confirmed, as the present results coincide with the previous ones. This agreement allows to go further, namely to examine the possibility of extracting relationships between C(sub surf) and the vertical composition of the algal assemblages. Thanks to the detailed pigment composition available from HPLC measurements, the contribution of three size classes (micro-, nano-, and pico-phytoplankton) to the local total chlorophyll a concentration can be assessed. Corroborating previous findings (e.g., large species dominate in eutrophc environments, whereas tiny phytoplankton prevail in oligotrophic zones), the results lead to a statistically based parameterization. The predictive skill of this parameterization is successfully tested on a separate data set. With such a tool, the vertical total chlorophyll a profiles associated with each size class can be inferred from the sole knowledge of C(sub surf). By combining this tool with satellite ocean color data, it becomes conceivable to quantify on a global scale the phytoplankton biomass associated with each of the three size classes.

Observational Data Analysis and Numerical Model Assessment of the Seafloor Interaction and Mobility of Sand and Weathered Oil Agglomerates (Surface Residual Balls) in the Surf Zone

NASA Astrophysics Data System (ADS)

Dalyander, S.; Long, J.; Plant, N. G.; Penko, A.; Calantoni, J.; Thompson, D.; Mclaughlin, M. K.

2014-12-01

When weathered oil is transported ashore, such as during the Deepwater Horizon oil spill, it can mix with suspended sediment in the surf zone to create heavier-than-water sand and oil agglomerates in the form of mats several centimeters thick and tens of meters long. Broken off pieces of these mats and smaller agglomerates formed in situ (called Surface Residual Balls, SRBs) can cause beach re-oiling months to years after the initial spill. The physical dynamics of these SRBs in the nearshore, where they are larger (cm-scale) and less dense than natural sediment, are poorly understood. In the current study, SRB mobility and seafloor interaction is investigated through a combination of laboratory and field experiments with pseudo-SRBs developed to be physically stable proxies for genuine agglomerates. Formulations for mobility prediction based on comparing estimated shear stress to the critical Shields and modified Shields parameters developed for mixed sediment beds are assessed against observations. Processes such as burial, exhumation, and interaction with bedforms (e.g., migrating ripples) are also explored. The observations suggest that incipient motion estimates based on a modified Shields parameter have some skill in predicting SRB movement, but that other forcing mechanisms such as pressure gradients may be important under some conditions. Additionally, burial and exhumation due to the relatively high mobility of sand grains are confirmed as key processes controlling SRB dynamics in the surf zone. This work has broad implications for understanding surf zone sediment transport at the short timescale associated with mobilizing sand grains and SRBs as well as at the longer timescales associated with net transport patterns, sediment budgets, and bed elevation changes.

High volume medical web sites.

PubMed

Elliott, B; Elliott, G

2000-01-01

In 1998, 22 million individuals reported surfing the web for medical information, and this number will increase to over 30 million by 2000. Fifteen of the highest volume medical web sites are described in this paper. Sponsorship and/or ownership of the fifteen sites varied. The government sponsors one, and some are the products of well-known educational institutions. One site is supported by a consumer health organization, and the American Medical Association was in the top 15. However, the most common owners are commercial, for-profit businesses. Attributes of the ideal site were categorized, and include a robust privacy and disclosure statement with an emphasis on education and an appropriate role for advertising. The covering of Complementary and Alternative Medicine (CAM) should be in a balanced and unbiased manner. There has to be an emphasis on knowledge based evidence as opposed to testimonials, and sources should be timely and reviewed. Bibliographies of authors need to be available. Hyperlinking to other web resources is valuable, as even the largest of sites cannot come close to covering all of medicine.

Internet dynamics

NASA Astrophysics Data System (ADS)

Lukose, Rajan Mathew

The World Wide Web and the Internet are rapidly expanding spaces, of great economic and social significance, which offer an opportunity to study many phenomena, often previously inaccessible, on an unprecedented scale and resolution with relative ease. These phenomena are measurable on the scale of tens of millions of users and hundreds of millions of pages. By virtue of nearly complete electronic mediation, it is possible in principle to observe the time and ``spatial'' evolution of nearly all choices and interactions. This cyber-space therefore provides a view into a number of traditional research questions (from many academic disciplines) and creates its own new phenomena accessible for study. Despite its largely self-organized and dynamic nature, a number of robust quantitative regularities are found in the aggregate statistics of interesting and useful quantities. These regularities can be understood with the help of models that draw on ideas from statistical physics as well as other fields such as economics, psychology and decision theory. This thesis develops models that can account for regularities found in the statistics of Internet congestion and user surfing patterns and discusses some practical consequences. practical consequences.

[Mitochondrial diseases in children including Leigh syndrome--biochemical and molecular background].

PubMed

Pronicka, Ewa; Piekutowska-Abramczuk, Dorota; Pronicki, Maciej

2008-01-01

Mitochondrial diseases in children are more frequently caused by mutations in nuclear DNA then in mtDNA. Special clinical phenotypes are associated with the mutations in SURF1 gene, in SCO2 gene and with mtDNA depletion syndromes. Leigh syndrome is the most common clinical presentation of various mitochondrial disorders during childhood. Elevation of lactate in blood, cerebrospinal fluid and urine is a simple biochemical marker of mitochondrial disorders but its specificity and sensitivity are low. Biochemical investigation of muscle biopsy and search for mitochondrial mutations remain a gold standard in the diagnosis. The standarized diagnostic criteria to establish level of diagnostic certainty (possible, probable, definite) are proposed to be used in practice; these include clinical features, neuroimaging and muscle biopsy investigations. Further research directions to improve our understanding of mitochondrial pathologies in children are suggested.

P04.19 Recommendations for computation of textural measures obtained from 3D brain tumor MRIs: A robustness analysis points out the need for standardization.

PubMed Central

Molina, D.; Pérez-Beteta, J.; Martínez-González, A.; Velásquez, C.; Martino, J.; Luque, B.; Revert, A.; Herruzo, I.; Arana, E.; Pérez-García, V. M.

2017-01-01

Abstract Introduction: Textural analysis refers to a variety of mathematical methods used to quantify the spatial variations in grey levels within images. In brain tumors, textural features have a great potential as imaging biomarkers having been shown to correlate with survival, tumor grade, tumor type, etc. However, these measures should be reproducible under dynamic range and matrix size changes for their clinical use. Our aim is to study this robustness in brain tumors with 3D magnetic resonance imaging, not previously reported in the literature. Materials and methods: 3D T1-weighted images of 20 patients with glioblastoma (64.80 ± 9.12 years-old) obtained from a 3T scanner were analyzed. Tumors were segmented using an in-house semi-automatic 3D procedure. A set of 16 3D textural features of the most common types (co-occurrence and run-length matrices) were selected, providing regional (run-length based measures) and local information (co-ocurrence matrices) on the tumor heterogeneity. Feature robustness was assessed by means of the coefficient of variation (CV) under both dynamic range (16, 32 and 64 gray levels) and/or matrix size (256x256 and 432x432) changes. Results: None of the textural features considered were robust under dynamic range changes. The textural co-occurrence matrix feature Entropy was the only textural feature robust (CV < 10%) under spatial resolution changes. Conclusions: In general, textural measures of three-dimensional brain tumor images are neither robust under dynamic range nor under matrix size changes. Thus, it becomes mandatory to fix standards for image rescaling after acquisition before the textural features are computed if they are to be used as imaging biomarkers. For T1-weighted images a dynamic range of 16 grey levels and a matrix size of 256x256 (and isotropic voxel) is found to provide reliable and comparable results and is feasible with current MRI scanners. The implications of this work go beyond the specific tumor type and MRI sequence studied here and pose the need for standardization in textural feature calculation of oncological images. FUNDING: James S. Mc. Donnell Foundation (USA) 21st Century Science Initiative in Mathematical and Complex Systems Approaches for Brain Cancer [Collaborative award 220020450 and planning grant 220020420], MINECO/FEDER [MTM2015-71200-R], JCCM [PEII-2014-031-P].

Robustness of Radiomic Features in [11C]Choline and [18F]FDG PET/CT Imaging of Nasopharyngeal Carcinoma: Impact of Segmentation and Discretization.

PubMed

Lu, Lijun; Lv, Wenbing; Jiang, Jun; Ma, Jianhua; Feng, Qianjin; Rahmim, Arman; Chen, Wufan

2016-12-01

Radiomic features are increasingly utilized to evaluate tumor heterogeneity in PET imaging and to enable enhanced prediction of therapy response and outcome. An important ingredient to success in translation of radiomic features to clinical reality is to quantify and ascertain their robustness. In the present work, we studied the impact of segmentation and discretization on 88 radiomic features in 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) and [ 11 C]methyl-choline ([ 11 C]choline) positron emission tomography/X-ray computed tomography (PET/CT) imaging of nasopharyngeal carcinoma. Forty patients underwent [ 18 F]FDG PET/CT scans. Of these, nine patients were imaged on a different day utilizing [ 11 C]choline PET/CT. Tumors were delineated using reference manual segmentation by the consensus of three expert physicians, using 41, 50, and 70 % maximum standardized uptake value (SUV max ) threshold with background correction, Nestle's method, and watershed and region growing methods, and then discretized with fixed bin size (0.05, 0.1, 0.2, 0.5, and 1) in units of SUV. A total of 88 features, including 21 first-order intensity features, 10 shape features, and 57 second- and higher-order textural features, were extracted from the tumors. The robustness of the features was evaluated via the intraclass correlation coefficient (ICC) for seven kinds of segmentation methods (involving all 88 features) and five kinds of discretization bin size (involving the 57 second- and higher-order features). Forty-four (50 %) and 55 (63 %) features depicted ICC ≥0.8 with respect to segmentation as obtained from [ 18 F]FDG and [ 11 C]choline, respectively. Thirteen (23 %) and 12 (21 %) features showed ICC ≥0.8 with respect to discretization as obtained from [ 18 F]FDG and [ 11 C]choline, respectively. Six features were obtained from both [ 18 F]FDG and [ 11 C]choline having ICC ≥0.8 for both segmentation and discretization, five of which were gray-level co-occurrence matrix (GLCM) features (SumEntropy, Entropy, DifEntropy, Homogeneity1, and Homogeneity2) and one of which was an neighborhood gray-tone different matrix (NGTDM) feature (Coarseness). Discretization generated larger effects on features than segmentation in both tracers. Features extracted from [ 11 C]choline were more robust than [ 18 F]FDG for segmentation. Discretization had very similar effects on features extracted from both tracers.

Mutational robustness accelerates the origin of novel RNA phenotypes through phenotypic plasticity.

PubMed

Wagner, Andreas

2014-02-18

Novel phenotypes can originate either through mutations in existing genotypes or through phenotypic plasticity, the ability of one genotype to form multiple phenotypes. From molecules to organisms, plasticity is a ubiquitous feature of life, and a potential source of exaptations, adaptive traits that originated for nonadaptive reasons. Another ubiquitous feature is robustness to mutations, although it is unknown whether such robustness helps or hinders the origin of new phenotypes through plasticity. RNA is ideal to address this question, because it shows extensive plasticity in its secondary structure phenotypes, a consequence of their continual folding and unfolding, and these phenotypes have important biological functions. Moreover, RNA is to some extent robust to mutations. This robustness structures RNA genotype space into myriad connected networks of genotypes with the same phenotype, and it influences the dynamics of evolving populations on a genotype network. In this study I show that both effects help accelerate the exploration of novel phenotypes through plasticity. My observations are based on many RNA molecules sampled at random from RNA sequence space, and on 30 biological RNA molecules. They are thus not only a generic feature of RNA sequence space but are relevant for the molecular evolution of biological RNA. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Neurophysiological profile of peripheral neuropathy associated with childhood mitochondrial disease.

PubMed

Menezes, Manoj P; Rahman, Shamima; Bhattacharya, Kaustuv; Clark, Damian; Christodoulou, John; Ellaway, Carolyn; Farrar, Michelle; Pitt, Matthew; Sampaio, Hugo; Ware, Tyson L; Wedatilake, Yehani; Thorburn, David R; Ryan, Monique M; Ouvrier, Robert

2016-09-01

Peripheral nerve involvement is common in mitochondrial disease but often unrecognised due to the prominent central nervous system features. Identification of the underlying neuropathy may assist syndrome classification, targeted genetic testing and rehabilitative interventions. Clinical data and the results of nerve conduction studies were obtained retrospectively from the records of four tertiary children's hospital metabolic disease, neuromuscular or neurophysiology services. Nerve conductions studies were also performed prospectively on children attending a tertiary metabolic disease service. Results were classified and analysed according to the underlying genetic cause. Nerve conduction studies from 27 children with mitochondrial disease were included in the study (mitochondrial DNA (mtDNA) - 7, POLG - 7, SURF1 - 10, PDHc deficiency - 3). Four children with mtDNA mutations had a normal study while three had mild abnormalities in the form of an axonal sensorimotor neuropathy when not acutely unwell. One child with MELAS had a severe acute axonal motor neuropathy during an acute stroke-like episode that resolved over 12months. Five children with POLG mutations and disease onset beyond infancy had a sensory ataxic neuropathy with an onset in the second decade of life, while the two infants with POLG mutations had a demyelinating neuropathy. Seven of the 10 children with SURF1 mutations had a demyelinating neuropathy. All three children with PDHc deficiency had an axonal sensorimotor neuropathy. Unlike CMT, the neuropathy associated with mitochondrial disease was not length-dependent. This is the largest study to date of peripheral neuropathy in genetically- classified childhood mitochondrial disease. Characterising the underlying neuropathy may assist with the diagnosis of the mitochondrial syndrome and should be an integral part of the assessment of children with suspected mitochondrial disease. Copyright © 2016 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

A founder mutation in PET100 causes isolated complex IV deficiency in Lebanese individuals with Leigh syndrome.

PubMed

Lim, Sze Chern; Smith, Katherine R; Stroud, David A; Compton, Alison G; Tucker, Elena J; Dasvarma, Ayan; Gandolfo, Luke C; Marum, Justine E; McKenzie, Matthew; Peters, Heidi L; Mowat, David; Procopis, Peter G; Wilcken, Bridget; Christodoulou, John; Brown, Garry K; Ryan, Michael T; Bahlo, Melanie; Thorburn, David R

2014-02-06

Leigh syndrome (LS) is a severe neurodegenerative disorder with characteristic bilateral lesions, typically in the brainstem and basal ganglia. It usually presents in infancy and is genetically heterogeneous, but most individuals with mitochondrial complex IV (or cytochrome c oxidase) deficiency have mutations in the biogenesis factor SURF1. We studied eight complex IV-deficient LS individuals from six families of Lebanese origin. They differed from individuals with SURF1 mutations in having seizures as a prominent feature. Complementation analysis suggested they had mutation(s) in the same gene but targeted massively parallel sequencing (MPS) of 1,034 genes encoding known mitochondrial proteins failed to identify a likely candidate. Linkage and haplotype analyses mapped the location of the gene to chromosome 19 and targeted MPS of the linkage region identified a homozygous c.3G>C (p.Met1?) mutation in C19orf79. Abolishing the initiation codon could potentially still allow initiation at a downstream methionine residue but we showed that this would not result in a functional protein. We confirmed that mutation of this gene was causative by lentiviral-mediated phenotypic correction. C19orf79 was recently renamed PET100 and predicted to encode a complex IV biogenesis factor. We showed that it is located in the mitochondrial inner membrane and forms a ∼300 kDa subcomplex with complex IV subunits. Previous proteomic analyses of mitochondria had overlooked PET100 because its small size was below the cutoff for annotating bona fide proteins. The mutation was estimated to have arisen at least 520 years ago, explaining how the families could have different religions and different geographic origins within Lebanon. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

LRPPRC mutations cause a phenotypically distinct form of Leigh syndrome with cytochrome c oxidase deficiency.

PubMed

Debray, François-Guillaume; Morin, Charles; Janvier, Annie; Villeneuve, Josée; Maranda, Bruno; Laframboise, Rachel; Lacroix, Jacques; Decarie, Jean-Claude; Robitaille, Yves; Lambert, Marie; Robinson, Brian H; Mitchell, Grant A

2011-03-01

The natural history of all known patients with French-Canadian Leigh disease (Saguenay-Lac-St-Jean cytochrome c oxidase deficiency, MIM220111, SLSJ-COX), the largest known cohort of patients with a genetically homogeneous, nuclear encoded congenital lactic acidosis, was studied. 55 of 56 patients were homozygous for the A354V mutation in LRPPRC. One was a genetic compound (A354V/C1277Xdel8). Clinical features included developmental delay, failure to thrive, characteristic facial appearance and, in 90% of patients, acute crises that have not previously been detailed, either metabolic (fulminant lactic acidosis) and/or neurological (Leigh syndrome and/or stroke-like episodes). Survival ranged from 5 days to >30 years. 46/56 patients (82%) died, at a median age of 1.6 years. Of 73 crises, 38 (52%) were fatal. The immediate causes of death were multiple organ failure and/or Leigh disease. Major predictors of mortality during crises (p<0.005) were hyperglycaemia, hepatic cytolysis, and altered consciousness at admission. Compared to a group of SURF1-deficient Leigh syndrome patients assembled from the literature, SLSJ-COX is distinct by the occurrence of metabolic crises, leading to earlier and higher mortality (p=0.001). SLSJ-COX is clinically distinct, with acute fatal acidotic crises on a backdrop of chronic moderate developmental delay and hyperlactataemia. Leigh syndrome is common. Stroke-like episodes can occur. The Leigh syndrome of SLSJ-COX differs from that of SURF1-related COX deficiency. SLSJ-COX has a different spectrum of associated abnormalities, acidotic crises being particularly suggestive of LRPPRC related Leigh syndrome. Even among A354V homozygotes, pronounced differences in survival and severity occur, showing that other genetic and/or environmental factors can influence outcome.

Comparison Between Surf and Multi-Shock Forest Fire High Explosive Burn Models

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

Greenfield, Nicholas Alexander

PAGOSA1 has several different burn models used to model high explosive detonation. Two of these, Multi-Shock Forest Fire and Surf, are capable of modeling shock initiation. Accurately calculating shock initiation of a high explosive is important because it is a mechanism for detonation in many accident scenarios (i.e. fragment impact). Comparing the models to pop-plot data give confidence that the models are accurately calculating detonation or lack thereof. To compare the performance of these models, pop-plots2 were created from simulations where one two cm block of PBX 9502 collides with another block of PBX 9502.

Mechanical interactions in bacterial colonies and the surfing probability of beneficial mutations

PubMed Central

Farrell, Fred D.

2017-01-01

Bacterial conglomerates such as biofilms and microcolonies are ubiquitous in nature and play an important role in industry and medicine. In contrast to well-mixed cultures routinely used in microbial research, bacteria in a microcolony interact mechanically with one another and with the substrate to which they are attached. Here, we use a computer model of a microbial colony of rod-shaped cells to investigate how physical interactions between cells determine their motion in the colony and how this affects biological evolution. We show that the probability that a faster-growing mutant ‘surfs’ at the colony's frontier and creates a macroscopic sector depends on physical properties of cells (shape, elasticity and friction). Although all these factors contribute to the surfing probability in seemingly different ways, their effects can be summarized by two summary statistics that characterize the front roughness and cell alignment. Our predictions are confirmed by experiments in which we measure the surfing probability for colonies of different front roughness. Our results show that physical interactions between bacterial cells play an important role in biological evolution of new traits, and suggest that these interactions may be relevant to processes such as de novo evolution of antibiotic resistance. PMID:28592660

Respiratory Problems Associated with Surfing in Coastal Waters.

PubMed

O'Halloran, Chris; Silver, Mary W; Lahiff, Maureen; Colford, John

2017-03-01

A pilot project was conducted to examine the health status and possible adverse health effects associated with seawater exposure (microbial water-quality indicators and phytoplankton abundance and their toxins) of surfers in Monterey Bay, Central California coastal waters. Forty-eight surfers enrolled in the study and completed an initial health background survey and weekly health surveys online using Survey Monkey. Descriptive statistics and generalized estimating equation, a regression technique, were used to identify longitudinal and correlated results. The surfers were predominately Caucasian, male, and physically active. They surfed approximately 4 h a week. Their average age was 34 years. The data indicated that the surfers were generally "healthy," with a low prevalence of diabetes, high cholesterol, and hypertension. Their most common health problems were allergies and asthma. During the study, 10% of the surfers reported gastrointestinal symptoms and 29% reported upper respiratory symptoms. This study suggests surfers were significantly more likely to report upper respiratory symptoms when they had a history of allergies, housemates with upper respiratory symptoms, and/or a history of previous adverse health symptoms while surfing during a "red tide" (an event often associated with the presence of phytoplankton toxins). Additionally, female surfers reported upper respiratory symptoms more than males.

Adverse health effects and unhealthy behaviors among medical students using Facebook.

PubMed

Al-Dubai, Sami Abdo Radman; Ganasegeran, Kurubaran; Al-Shagga, Mustafa Ahmed Mahdi; Yadav, Hematram; Arokiasamy, John T

2013-01-01

Little is known about the relationships between adverse health effects and unhealthy behaviors among medical students using Facebook. The aim of this study was to determine the associations between adverse health effects and unhealthy behaviors with Facebook use. A cross-sectional study was conducted in a private university in Malaysia among 316 medical students. A self-administered questionnaire was used. It included questions on sociodemographics, pattern of Facebook use, social relationship, unhealthy behaviors, and health effects. Mean age was 20.5 (±2.7) years. All students had a Facebook account. The average daily Facebook surfing hours were 2.5 (±1.7). Significant associations were found between average hours of Facebook surfing and the following factors: isolation from family members and community, refusing to answer calls, musculoskeletal pain, headache, and eye irritation (P < 0.005). The average hours spent on Facebook were significantly associated with holding urination and defecation while online, surfing Facebook until midnight, and postponing, forgetting, or skipping meals (P < 0.005). The average hours spent on Facebook were associated with adverse health effects and unhealthy behaviors among medical students, as well as social isolation from the family and community.

Rapid overt airborne reconnaissance (ROAR) for mines and obstacles in very shallow water, surf zone, and beach

NASA Astrophysics Data System (ADS)

Moran, Steven E.; Austin, William L.; Murray, James T.; Roddier, Nicolas A.; Bridges, Robert; Vercillo, Richard; Stettner, Roger; Phillips, Dave; Bisbee, Al; Witherspoon, Ned H.

2003-09-01

Under the Office of Naval Research's Organic Mine Countermeasures Future Naval Capabilities (OMCM FNC) program, Lite Cycles, Inc. is developing an innovative and highly compact airborne active sensor system for mine and obstacle detection in very shallow water (VSW), through the surf-zone (SZ) and onto the beach. The system uses an innovative LCI proprietary integrated scanner, detector, and telescope (ISDT) receiver architecture. The ISD tightly couples all receiver components and LIDAR electronics to achieve the system compaction required for tactical UAVintegration while providing a large aperture. It also includes an advanced compact multifunction laser transmitter; an industry-first high-resolution, compact 3-D camera, a scanning function for wide area search, and temporally displaced multiple looks on the fly over the ocean surface for clutter reduction. Additionally, the laser will provide time-multiplexed multi-color output to perform day/night multispectral imaging for beach surveillance. New processing algorithms for mine detection in the very challenging surf-zone clutter environment are under development, which offer the potential for significant processing gains in comparison to the legacy approaches. This paper reviews the legacy system approaches, describes the mission challenges, and provides an overview of the ROAR system architecture.

Adverse Health Effects and Unhealthy Behaviors among Medical Students Using Facebook

PubMed Central

Al-Dubai, Sami Abdo Radman; Al-Shagga, Mustafa Ahmed Mahdi; Yadav, Hematram; Arokiasamy, John T.

2013-01-01

Little is known about the relationships between adverse health effects and unhealthy behaviors among medical students using Facebook. The aim of this study was to determine the associations between adverse health effects and unhealthy behaviors with Facebook use. A cross-sectional study was conducted in a private university in Malaysia among 316 medical students. A self-administered questionnaire was used. It included questions on sociodemographics, pattern of Facebook use, social relationship, unhealthy behaviors, and health effects. Mean age was 20.5 (±2.7) years. All students had a Facebook account. The average daily Facebook surfing hours were 2.5 (±1.7). Significant associations were found between average hours of Facebook surfing and the following factors: isolation from family members and community, refusing to answer calls, musculoskeletal pain, headache, and eye irritation (P < 0.005). The average hours spent on Facebook were significantly associated with holding urination and defecation while online, surfing Facebook until midnight, and postponing, forgetting, or skipping meals (P < 0.005). The average hours spent on Facebook were associated with adverse health effects and unhealthy behaviors among medical students, as well as social isolation from the family and community. PMID:24453859

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

Heise, J.

The former Homestake gold mine in Lead, South Dakota, has been transformed into a dedicated facility to pursue underground research in rare-process physics, as well as offering research opportunities in other disciplines such as biology, geology and engineering. A key component of the Sanford Underground Research Facility (SURF) is the Davis Campus, which is in operation at the 4850-foot level (4300 m.w.e.) and currently hosts two main physics projects: the LUX dark matter experiment and the MAJORANA DEMONSTRATOR neutrinoless double-beta decay experiment. In addition, two low-background counters currently operate at the Davis Campus in support of current and future experiments. Expansionmore » of the underground laboratory space is underway at the 4850L Ross Campus in order to maintain and enhance low-background assay capabilities as well as to host a unique nuclear astrophysics accelerator facility. Plans to accommodate other future experiments at SURF are also underway and include the next generation of direct-search dark matter experiments and the Fermilab-led international long-baseline neutrino program. Planning to understand the infrastructure developments necessary to accommodate these future projects is well advanced and in some cases have already started. SURF is a dedicated research facility with significant expansion capability.« less

Acute injuries in recreational and competitive surfers: incidence, severity, location, type, and mechanism.

PubMed

Furness, James; Hing, Wayne; Walsh, Joe; Abbott, Allan; Sheppard, Jeremy M; Climstein, Mike

2015-05-01

There are an estimated 37 million surfers worldwide, with 2.5 million recreational surfers in Australia. The recreational activity and sport of surfing has grown dramatically since the 1960s, but scientific research has been poorly mirrored in comparison with most other mainstream sports. To identify the incidence, severity, location, type, and mechanism of acute injuries in recreational and competitive surfers over a 12-month period. Descriptive epidemiology study. An online survey using an open-source survey application was utilized. The survey consisted of 2 primary sections: Section 1 included demographic information and participation levels (age, height, weight, hours surfed, competitive level); section 2 incorporated injury type, mechanism, severity, and injury management. A total of 1348 participants (91.3% males; 43.1% competitive surfers) were included in data analysis. A total of 512 acute injuries were classified as major, providing an incidence proportion of 0.38 (CI, 0.35-0.41) acute injuries per year. The incidence rate was calculated to be 1.79 (CI, 1.67-1.92) major injuries per 1000 hours of surfing. The shoulder, ankle, and head/face regions had the highest frequencies of acute injury, representing 16.4%, 14.6%, and 13.3%, respectively. Injuries were predominantly of muscular, joint, and skin origin, representing 30.3%, 27.7%, and 18.9%, respectively. Skin injuries were primarily a result of direct trauma, while joint and muscular injuries were mainly a result of maneuvers performed and repetitive actions. Key risk factors that increased the incidence of sustaining an acute injury included competitive status, hours surfed (>6.5 hours/week), and the ability to perform aerial maneuvers. The incidence proportion for surfers completing aerial maneuvers was calculated to be 0.48 (CI, 0.39-0.58) major injuries per year, this being the highest incidence proportion irrespective of competitive status. This is the largest surfing-specific survey that included both recreational and competitive surfers conducted in Australia to date. The shoulder, ankle, head, and face were identified as the key regions where acute injuries occur in surfers. This research may aid in reducing the occurrence of injury through musculoskeletal screening in these key injury-prone regions and through the use of sport-specific strength training and conditioning. © 2015 The Author(s).

Optimized feature-detection for on-board vision-based surveillance

NASA Astrophysics Data System (ADS)

Gond, Laetitia; Monnin, David; Schneider, Armin

2012-06-01

The detection and matching of robust features in images is an important step in many computer vision applications. In this paper, the importance of the keypoint detection algorithms and their inherent parameters in the particular context of an image-based change detection system for IED detection is studied. Through extensive application-oriented experiments, we draw an evaluation and comparison of the most popular feature detectors proposed by the computer vision community. We analyze how to automatically adjust these algorithms to changing imaging conditions and suggest improvements in order to achieve more exibility and robustness in their practical implementation.

Identifying in vivo DCE MRI markers associated with microvessel architecture and gleason grades of prostate cancer.

PubMed

Singanamalli, Asha; Rusu, Mirabela; Sparks, Rachel E; Shih, Natalie N C; Ziober, Amy; Wang, Li-Ping; Tomaszewski, John; Rosen, Mark; Feldman, Michael; Madabhushi, Anant

2016-01-01

To identify computer extracted in vivo dynamic contrast enhanced (DCE) MRI markers associated with quantitative histomorphometric (QH) characteristics of microvessels and Gleason scores (GS) in prostate cancer. This study considered retrospective data from 23 biopsy confirmed prostate cancer patients who underwent 3 Tesla multiparametric MRI before radical prostatectomy (RP). Representative slices from RP specimens were stained with vascular marker CD31. Tumor extent was mapped from RP sections onto DCE MRI using nonlinear registration methods. Seventy-seven microvessel QH features and 18 DCE MRI kinetic features were extracted and evaluated for their ability to distinguish low from intermediate and high GS. The effect of temporal sampling on kinetic features was assessed and correlations between those robust to temporal resolution and microvessel features discriminative of GS were examined. A total of 12 microvessel architectural features were discriminative of low and intermediate/high grade tumors with area under the receiver operating characteristic curve (AUC) > 0.7. These features were most highly correlated with mean washout gradient (WG) (max rho = -0.62). Independent analysis revealed WG to be moderately robust to temporal resolution (intraclass correlation coefficient [ICC] = 0.63) and WG variance, which was poorly correlated with microvessel features, to be predictive of low grade tumors (AUC = 0.77). Enhancement ratio was the most robust (ICC = 0.96) and discriminative (AUC = 0.78) kinetic feature but was moderately correlated with microvessel features (max rho = -0.52). Computer extracted features of prostate DCE MRI appear to be correlated with microvessel architecture and may be discriminative of low versus intermediate and high GS. © 2015 Wiley Periodicals, Inc.

Iris Matching Based on Personalized Weight Map.

PubMed

Dong, Wenbo; Sun, Zhenan; Tan, Tieniu

2011-09-01

Iris recognition typically involves three steps, namely, iris image preprocessing, feature extraction, and feature matching. The first two steps of iris recognition have been well studied, but the last step is less addressed. Each human iris has its unique visual pattern and local image features also vary from region to region, which leads to significant differences in robustness and distinctiveness among the feature codes derived from different iris regions. However, most state-of-the-art iris recognition methods use a uniform matching strategy, where features extracted from different regions of the same person or the same region for different individuals are considered to be equally important. This paper proposes a personalized iris matching strategy using a class-specific weight map learned from the training images of the same iris class. The weight map can be updated online during the iris recognition procedure when the successfully recognized iris images are regarded as the new training data. The weight map reflects the robustness of an encoding algorithm on different iris regions by assigning an appropriate weight to each feature code for iris matching. Such a weight map trained by sufficient iris templates is convergent and robust against various noise. Extensive and comprehensive experiments demonstrate that the proposed personalized iris matching strategy achieves much better iris recognition performance than uniform strategies, especially for poor quality iris images.

Similarity preserving low-rank representation for enhanced data representation and effective subspace learning.

PubMed

Zhang, Zhao; Yan, Shuicheng; Zhao, Mingbo

2014-05-01

Latent Low-Rank Representation (LatLRR) delivers robust and promising results for subspace recovery and feature extraction through mining the so-called hidden effects, but the locality of both similar principal and salient features cannot be preserved in the optimizations. To solve this issue for achieving enhanced performance, a boosted version of LatLRR, referred to as Regularized Low-Rank Representation (rLRR), is proposed through explicitly including an appropriate Laplacian regularization that can maximally preserve the similarity among local features. Resembling LatLRR, rLRR decomposes given data matrix from two directions by seeking a pair of low-rank matrices. But the similarities of principal and salient features can be effectively preserved by rLRR. As a result, the correlated features are well grouped and the robustness of representations is also enhanced. Based on the outputted bi-directional low-rank codes by rLRR, an unsupervised subspace learning framework termed Low-rank Similarity Preserving Projections (LSPP) is also derived for feature learning. The supervised extension of LSPP is also discussed for discriminant subspace learning. The validity of rLRR is examined by robust representation and decomposition of real images. Results demonstrated the superiority of our rLRR and LSPP in comparison to other related state-of-the-art algorithms. Copyright © 2014 Elsevier Ltd. All rights reserved.

On the contributions of topological features to transcriptional regulatory network robustness

PubMed Central

2012-01-01

Background Because biological networks exhibit a high-degree of robustness, a systemic understanding of their architecture and function requires an appraisal of the network design principles that confer robustness. In this project, we conduct a computational study of the contribution of three degree-based topological properties (transcription factor-target ratio, degree distribution, cross-talk suppression) and their combinations on the robustness of transcriptional regulatory networks. We seek to quantify the relative degree of robustness conferred by each property (and combination) and also to determine the extent to which these properties alone can explain the robustness observed in transcriptional networks. Results To study individual properties and their combinations, we generated synthetic, random networks that retained one or more of the three properties with values derived from either the yeast or E. coli gene regulatory networks. Robustness of these networks were estimated through simulation. Our results indicate that the combination of the three properties we considered explains the majority of the structural robustness observed in the real transcriptional networks. Surprisingly, scale-free degree distribution is, overall, a minor contributor to robustness. Instead, most robustness is gained through topological features that limit the complexity of the overall network and increase the transcription factor subnetwork sparsity. Conclusions Our work demonstrates that (i) different types of robustness are implemented by different topological aspects of the network and (ii) size and sparsity of the transcription factor subnetwork play an important role for robustness induction. Our results are conserved across yeast and E Coli, which suggests that the design principles examined are present within an array of living systems. PMID:23194062

Indirect Correspondence-Based Robust Extrinsic Calibration of LiDAR and Camera

PubMed Central

Sim, Sungdae; Sock, Juil; Kwak, Kiho

2016-01-01

LiDAR and cameras have been broadly utilized in computer vision and autonomous vehicle applications. However, in order to convert data between the local coordinate systems, we must estimate the rigid body transformation between the sensors. In this paper, we propose a robust extrinsic calibration algorithm that can be implemented easily and has small calibration error. The extrinsic calibration parameters are estimated by minimizing the distance between corresponding features projected onto the image plane. The features are edge and centerline features on a v-shaped calibration target. The proposed algorithm contributes two ways to improve the calibration accuracy. First, we use different weights to distance between a point and a line feature according to the correspondence accuracy of the features. Second, we apply a penalizing function to exclude the influence of outliers in the calibration datasets. Additionally, based on our robust calibration approach for a single LiDAR-camera pair, we introduce a joint calibration that estimates the extrinsic parameters of multiple sensors at once by minimizing one objective function with loop closing constraints. We conduct several experiments to evaluate the performance of our extrinsic calibration algorithm. The experimental results show that our calibration method has better performance than the other approaches. PMID:27338416

Curve Set Feature-Based Robust and Fast Pose Estimation Algorithm

PubMed Central

Hashimoto, Koichi

2017-01-01

Bin picking refers to picking the randomly-piled objects from a bin for industrial production purposes, and robotic bin picking is always used in automated assembly lines. In order to achieve a higher productivity, a fast and robust pose estimation algorithm is necessary to recognize and localize the randomly-piled parts. This paper proposes a pose estimation algorithm for bin picking tasks using point cloud data. A novel descriptor Curve Set Feature (CSF) is proposed to describe a point by the surface fluctuation around this point and is also capable of evaluating poses. The Rotation Match Feature (RMF) is proposed to match CSF efficiently. The matching process combines the idea of the matching in 2D space of origin Point Pair Feature (PPF) algorithm with nearest neighbor search. A voxel-based pose verification method is introduced to evaluate the poses and proved to be more than 30-times faster than the kd-tree-based verification method. Our algorithm is evaluated against a large number of synthetic and real scenes and proven to be robust to noise, able to detect metal parts, more accurately and more than 10-times faster than PPF and Oriented, Unique and Repeatable (OUR)-Clustered Viewpoint Feature Histogram (CVFH). PMID:28771216

Robust object matching for persistent tracking with heterogeneous features.

PubMed

Guo, Yanlin; Hsu, Steve; Sawhney, Harpreet S; Kumar, Rakesh; Shan, Ying

2007-05-01

This paper addresses the problem of matching vehicles across multiple sightings under variations in illumination and camera poses. Since multiple observations of a vehicle are separated in large temporal and/or spatial gaps, thus prohibiting the use of standard frame-to-frame data association, we employ features extracted over a sequence during one time interval as a vehicle fingerprint that is used to compute the likelihood that two or more sequence observations are from the same or different vehicles. Furthermore, since our domain is aerial video tracking, in order to deal with poor image quality and large resolution and quality variations, our approach employs robust alignment and match measures for different stages of vehicle matching. Most notably, we employ a heterogeneous collection of features such as lines, points, and regions in an integrated matching framework. Heterogeneous features are shown to be important. Line and point features provide accurate localization and are employed for robust alignment across disparate views. The challenges of change in pose, aspect, and appearances across two disparate observations are handled by combining a novel feature-based quasi-rigid alignment with flexible matching between two or more sequences. However, since lines and points are relatively sparse, they are not adequate to delineate the object and provide a comprehensive matching set that covers the complete object. Region features provide a high degree of coverage and are employed for continuous frames to provide a delineation of the vehicle region for subsequent generation of a match measure. Our approach reliably delineates objects by representing regions as robust blob features and matching multiple regions to multiple regions using Earth Mover's Distance (EMD). Extensive experimentation under a variety of real-world scenarios and over hundreds of thousands of Confirmatory Identification (CID) trails has demonstrated about 95 percent accuracy in vehicle reacquisition with both visible and Infrared (IR) imaging cameras.

AutoCellSeg: robust automatic colony forming unit (CFU)/cell analysis using adaptive image segmentation and easy-to-use post-editing techniques.

PubMed

Khan, Arif Ul Maula; Torelli, Angelo; Wolf, Ivo; Gretz, Norbert

2018-05-08

In biological assays, automated cell/colony segmentation and counting is imperative owing to huge image sets. Problems occurring due to drifting image acquisition conditions, background noise and high variation in colony features in experiments demand a user-friendly, adaptive and robust image processing/analysis method. We present AutoCellSeg (based on MATLAB) that implements a supervised automatic and robust image segmentation method. AutoCellSeg utilizes multi-thresholding aided by a feedback-based watershed algorithm taking segmentation plausibility criteria into account. It is usable in different operation modes and intuitively enables the user to select object features interactively for supervised image segmentation method. It allows the user to correct results with a graphical interface. This publicly available tool outperforms tools like OpenCFU and CellProfiler in terms of accuracy and provides many additional useful features for end-users.

Robust Learning of High-dimensional Biological Networks with Bayesian Networks

NASA Astrophysics Data System (ADS)

Nägele, Andreas; Dejori, Mathäus; Stetter, Martin

Structure learning of Bayesian networks applied to gene expression data has become a potentially useful method to estimate interactions between genes. However, the NP-hardness of Bayesian network structure learning renders the reconstruction of the full genetic network with thousands of genes unfeasible. Consequently, the maximal network size is usually restricted dramatically to a small set of genes (corresponding with variables in the Bayesian network). Although this feature reduction step makes structure learning computationally tractable, on the downside, the learned structure might be adversely affected due to the introduction of missing genes. Additionally, gene expression data are usually very sparse with respect to the number of samples, i.e., the number of genes is much greater than the number of different observations. Given these problems, learning robust network features from microarray data is a challenging task. This chapter presents several approaches tackling the robustness issue in order to obtain a more reliable estimation of learned network features.

Robust Video Stabilization Using Particle Keypoint Update and l1-Optimized Camera Path

PubMed Central

Jeon, Semi; Yoon, Inhye; Jang, Jinbeum; Yang, Seungji; Kim, Jisung; Paik, Joonki

2017-01-01

Acquisition of stabilized video is an important issue for various type of digital cameras. This paper presents an adaptive camera path estimation method using robust feature detection to remove shaky artifacts in a video. The proposed algorithm consists of three steps: (i) robust feature detection using particle keypoints between adjacent frames; (ii) camera path estimation and smoothing; and (iii) rendering to reconstruct a stabilized video. As a result, the proposed algorithm can estimate the optimal homography by redefining important feature points in the flat region using particle keypoints. In addition, stabilized frames with less holes can be generated from the optimal, adaptive camera path that minimizes a temporal total variation (TV). The proposed video stabilization method is suitable for enhancing the visual quality for various portable cameras and can be applied to robot vision, driving assistant systems, and visual surveillance systems. PMID:28208622

Image ratio features for facial expression recognition application.

PubMed

Song, Mingli; Tao, Dacheng; Liu, Zicheng; Li, Xuelong; Zhou, Mengchu

2010-06-01

Video-based facial expression recognition is a challenging problem in computer vision and human-computer interaction. To target this problem, texture features have been extracted and widely used, because they can capture image intensity changes raised by skin deformation. However, existing texture features encounter problems with albedo and lighting variations. To solve both problems, we propose a new texture feature called image ratio features. Compared with previously proposed texture features, e.g., high gradient component features, image ratio features are more robust to albedo and lighting variations. In addition, to further improve facial expression recognition accuracy based on image ratio features, we combine image ratio features with facial animation parameters (FAPs), which describe the geometric motions of facial feature points. The performance evaluation is based on the Carnegie Mellon University Cohn-Kanade database, our own database, and the Japanese Female Facial Expression database. Experimental results show that the proposed image ratio feature is more robust to albedo and lighting variations, and the combination of image ratio features and FAPs outperforms each feature alone. In addition, we study asymmetric facial expressions based on our own facial expression database and demonstrate the superior performance of our combined expression recognition system.

Reframing video gaming and internet use addiction: empirical cross-national comparison of heavy use over time and addiction scales among young users.

PubMed

Baggio, Stéphanie; Dupuis, Marc; Studer, Joseph; Spilka, Stanislas; Daeppen, Jean-Bernard; Simon, Olivier; Berchtold, André; Gmel, Gerhard

2016-03-01

Evidence-based and reliable measures of addictive disorders are needed in general population-based assessments. One study suggested that heavy use over time (UOT) should be used instead of self-reported addiction scales (AS). This study compared UOT and AS regarding video gaming and internet use empirically, using associations with comorbid factors. Cross-sectional data from the 2011 French Survey on Health and Consumption on Call-up and Preparation for Defence-Day (ESCAPAD), cross-sectional data from the 2012 Swiss ado@internet.ch study and two waves of longitudinal data (2010-13) of the Swiss Longitudinal Cohort Study on Substance Use Risk Factors (C-SURF). Three representative samples from the general population of French and Swiss adolescents and young Swiss men, aged approximately 17, 14 and 20 years, respectively. ESCAPAD: n =22 945 (47.4% men); ado@internet.ch: n =3049 (50% men); C-SURF: n =4813 (baseline + follow-up, 100% men). We assessed video gaming/internet UOT ESCAPAD and ado@internet.ch: number of hours spent online per week, C-SURF: latent score of time spent gaming/using internet] and AS (ESCAPAD: Problematic Internet Use Questionnaire, ado@internet.ch: Internet Addiction Test, C-SURF: Gaming AS). Comorbidities were assessed with health outcomes (ESCAPAD: physical health evaluation with a single item, suicidal thoughts, and appointment with a psychiatrist; ado@internet.ch: WHO-5 and somatic health problems; C-SURF: Short Form 12 (SF-12 Health Survey) and Major Depression Inventory (MDI). UOT and AS were correlated moderately (ESCAPAD: r = 0.40, ado@internet.ch: r = 0.53 and C-SURF: r = 0.51). Associations of AS with comorbidity factors were higher than those of UOT in cross-sectional (AS: .005 ≤ |b| ≤ 2.500, UOT: 0.001 ≤ |b| ≤ 1.000) and longitudinal analyses (AS: 0.093 ≤ |b| ≤ 1.079, UOT: 0.020 ≤ |b| ≤ 0.329). The results were similar across gender in ESCAPAD and ado@internet.ch (men: AS: 0.006 ≤ |b| ≤ 0.211, UOT: 0.001 ≤ |b| ≤ 0.061; women: AS: 0.004 ≤ |b| ≤ 0.155, UOT: 0.001 ≤ |b| ≤ 0.094). The measurement of heavy use over time captures part of addictive video gaming/internet use without overlapping to a large extent with the results of measuring by self-reported addiction scales (AS). Measuring addictive video gaming/internet use via self-reported addiction scales relates more strongly to comorbidity factors than heavy use over time. © 2015 Society for the Study of Addiction.

A method of plane geometry primitive presentation

NASA Astrophysics Data System (ADS)

Jiao, Anbo; Luo, Haibo; Chang, Zheng; Hui, Bin

2014-11-01

Point feature and line feature are basic elements in object feature sets, and they play an important role in object matching and recognition. On one hand, point feature is sensitive to noise; on the other hand, there are usually a huge number of point features in an image, which makes it complex for matching. Line feature includes straight line segment and curve. One difficulty in straight line segment matching is the uncertainty of endpoint location, the other is straight line segment fracture problem or short straight line segments joined to form long straight line segment. While for the curve, in addition to the above problems, there is another difficulty in how to quantitatively describe the shape difference between curves. Due to the problems of point feature and line feature, the robustness and accuracy of target description will be affected; in this case, a method of plane geometry primitive presentation is proposed to describe the significant structure of an object. Firstly, two types of primitives are constructed, they are intersecting line primitive and blob primitive. Secondly, a line segment detector (LSD) is applied to detect line segment, and then intersecting line primitive is extracted. Finally, robustness and accuracy of the plane geometry primitive presentation method is studied. This method has a good ability to obtain structural information of the object, even if there is rotation or scale change of the object in the image. Experimental results verify the robustness and accuracy of this method.

Variability in CT lung-nodule quantification: Effects of dose reduction and reconstruction methods on density and texture based features.

PubMed

Lo, P; Young, S; Kim, H J; Brown, M S; McNitt-Gray, M F

2016-08-01

To investigate the effects of dose level and reconstruction method on density and texture based features computed from CT lung nodules. This study had two major components. In the first component, a uniform water phantom was scanned at three dose levels and images were reconstructed using four conventional filtered backprojection (FBP) and four iterative reconstruction (IR) methods for a total of 24 different combinations of acquisition and reconstruction conditions. In the second component, raw projection (sinogram) data were obtained for 33 lung nodules from patients scanned as a part of their clinical practice, where low dose acquisitions were simulated by adding noise to sinograms acquired at clinical dose levels (a total of four dose levels) and reconstructed using one FBP kernel and two IR kernels for a total of 12 conditions. For the water phantom, spherical regions of interest (ROIs) were created at multiple locations within the water phantom on one reference image obtained at a reference condition. For the lung nodule cases, the ROI of each nodule was contoured semiautomatically (with manual editing) from images obtained at a reference condition. All ROIs were applied to their corresponding images reconstructed at different conditions. For 17 of the nodule cases, repeat contours were performed to assess repeatability. Histogram (eight features) and gray level co-occurrence matrix (GLCM) based texture features (34 features) were computed for all ROIs. For the lung nodule cases, the reference condition was selected to be 100% of clinical dose with FBP reconstruction using the B45f kernel; feature values calculated from other conditions were compared to this reference condition. A measure was introduced, which the authors refer to as Q, to assess the stability of features across different conditions, which is defined as the ratio of reproducibility (across conditions) to repeatability (across repeat contours) of each feature. The water phantom results demonstrated substantial variability among feature values calculated across conditions, with the exception of histogram mean. Features calculated from lung nodules demonstrated similar results with histogram mean as the most robust feature (Q ≤ 1), having a mean and standard deviation Q of 0.37 and 0.22, respectively. Surprisingly, histogram standard deviation and variance features were also quite robust. Some GLCM features were also quite robust across conditions, namely, diff. variance, sum variance, sum average, variance, and mean. Except for histogram mean, all features have a Q of larger than one in at least one of the 3% dose level conditions. As expected, the histogram mean is the most robust feature in their study. The effects of acquisition and reconstruction conditions on GLCM features vary widely, though trending toward features involving summation of product between intensities and probabilities being more robust, barring a few exceptions. Overall, care should be taken into account for variation in density and texture features if a variety of dose and reconstruction conditions are used for the quantification of lung nodules in CT, otherwise changes in quantification results may be more reflective of changes due to acquisition and reconstruction conditions than in the nodule itself.

Multiclass feature selection for improved pediatric brain tumor segmentation

NASA Astrophysics Data System (ADS)

Ahmed, Shaheen; Iftekharuddin, Khan M.

2012-03-01

In our previous work, we showed that fractal-based texture features are effective in detection, segmentation and classification of posterior-fossa (PF) pediatric brain tumor in multimodality MRI. We exploited an information theoretic approach such as Kullback-Leibler Divergence (KLD) for feature selection and ranking different texture features. We further incorporated the feature selection technique with segmentation method such as Expectation Maximization (EM) for segmentation of tumor T and non tumor (NT) tissues. In this work, we extend the two class KLD technique to multiclass for effectively selecting the best features for brain tumor (T), cyst (C) and non tumor (NT). We further obtain segmentation robustness for each tissue types by computing Bay's posterior probabilities and corresponding number of pixels for each tissue segments in MRI patient images. We evaluate improved tumor segmentation robustness using different similarity metric for 5 patients in T1, T2 and FLAIR modalities.

How do patients between the age of 65 and 75 use a web-based decision aid for treatment choice in localized prostate cancer?

PubMed

Schrijvers, Jessie; Vanderhaegen, Joke; Van Poppel, Hendrik; Haustermans, Karin; Van Audenhove, Chantal

2013-08-01

This study was designed to evaluate the use of a web-based decision aid by a 65plus patient group in their decision-making process for treatment of localized prostate cancer. Of particular interest was the use of technology features such as patients' statements, comparative tables, and a values clarification tool. One hundred men from the University Hospital of Leuven campus, Gasthuisberg, were invited to use the web-based decision aid in their decision-making process. Twenty-six men were excluded based on non- or limited use of the decision aid. Of the remaining 74 men, user specifications, decision aid surfing characteristics by means of web-log data, and especially the use of technology features were analyzed. Men spent on average 30 minutes on the web-based decision aid. Most time was spent on the pages with information on treatment options. These pages were also most frequently accessed. The use of the feature 'comparative tables' was the highest, followed by the 'values clarification tool'. According to age (<70 or >70 years) differences were observed for the time spent on the decision aid, the pages accessed, and the use of the technology features. Despite concerns about the usability of a web-based decision aid for elderly patients, these results indicated that the majority of 65plus persons with good internet skills use a web-based decision aid as well as its incorporated technology features. © 2013 Wiley Publishing Asia Pty Ltd and Chinese Cochrane Center, West China Hospital of Sichuan University.

Automatic tracking of cells for video microscopy in patch clamp experiments

PubMed Central

2014-01-01

Background Visualisation of neurons labeled with fluorescent proteins or compounds generally require exposure to intense light for a relatively long period of time, often leading to bleaching of the fluorescent probe and photodamage of the tissue. Here we created a technique to drastically shorten light exposure and improve the targeting of fluorescent labeled cells that is specially useful for patch-clamp recordings. We applied image tracking and mask overlay to reduce the time of fluorescence exposure and minimise mistakes when identifying neurons. Methods Neurons are first identified according to visual criteria (e.g. fluorescence protein expression, shape, viability etc.) and a transmission microscopy image Differential Interference Contrast (DIC) or Dodt contrast containing the cell used as a reference for the tracking algorithm. A fluorescence image can also be acquired later to be used as a mask (that can be overlaid on the target during live transmission video). As patch-clamp experiments require translating the microscope stage, we used pattern matching to track reference neurons in order to move the fluorescence mask to match the new position of the objective in relation to the sample. For the image processing we used the Open Source Computer Vision (OpenCV) library, including the Speeded-Up Robust Features (SURF) for tracking cells. The dataset of images (n = 720) was analyzed under normal conditions of acquisition and with influence of noise (defocusing and brightness). Results We validated the method in dissociated neuronal cultures and fresh brain slices expressing Enhanced Yellow Fluorescent Protein (eYFP) or Tandem Dimer Tomato (tdTomato) proteins, which considerably decreased the exposure to fluorescence excitation, thereby minimising photodamage. We also show that the neuron tracking can be used in differential interference contrast or Dodt contrast microscopy. Conclusion The techniques of digital image processing used in this work are an important addition to the set of microscopy tools used in modern electrophysiology, specially in experiments with neuron cultures and brain slices. PMID:24946774

Automatic tracking of cells for video microscopy in patch clamp experiments.

PubMed

Peixoto, Helton M; Munguba, Hermany; Cruz, Rossana M S; Guerreiro, Ana M G; Leao, Richardson N

2014-06-20

Visualisation of neurons labeled with fluorescent proteins or compounds generally require exposure to intense light for a relatively long period of time, often leading to bleaching of the fluorescent probe and photodamage of the tissue. Here we created a technique to drastically shorten light exposure and improve the targeting of fluorescent labeled cells that is specially useful for patch-clamp recordings. We applied image tracking and mask overlay to reduce the time of fluorescence exposure and minimise mistakes when identifying neurons. Neurons are first identified according to visual criteria (e.g. fluorescence protein expression, shape, viability etc.) and a transmission microscopy image Differential Interference Contrast (DIC) or Dodt contrast containing the cell used as a reference for the tracking algorithm. A fluorescence image can also be acquired later to be used as a mask (that can be overlaid on the target during live transmission video). As patch-clamp experiments require translating the microscope stage, we used pattern matching to track reference neurons in order to move the fluorescence mask to match the new position of the objective in relation to the sample. For the image processing we used the Open Source Computer Vision (OpenCV) library, including the Speeded-Up Robust Features (SURF) for tracking cells. The dataset of images (n = 720) was analyzed under normal conditions of acquisition and with influence of noise (defocusing and brightness). We validated the method in dissociated neuronal cultures and fresh brain slices expressing Enhanced Yellow Fluorescent Protein (eYFP) or Tandem Dimer Tomato (tdTomato) proteins, which considerably decreased the exposure to fluorescence excitation, thereby minimising photodamage. We also show that the neuron tracking can be used in differential interference contrast or Dodt contrast microscopy. The techniques of digital image processing used in this work are an important addition to the set of microscopy tools used in modern electrophysiology, specially in experiments with neuron cultures and brain slices.

Attributing Contributions of Climate Feedbacks to the Seasonal Cycle of Surface Warming due to CO2 Increase

NASA Astrophysics Data System (ADS)

Sejas, S.; Cai, M.

2012-12-01

Surfing warming due to CO2 doubling is a robust feature of coupled general circulation models (GCM), as noted in the IPCC AR4 assessment report. In this study, the contributions of different climate feedbacks to the magnitude, spatial distribution, and seasonality of the surface warming is examined using data from NCAR's CCSM4. In particular, a focus is placed on polar regions to see which feedbacks play a role in polar amplification and its seasonal pattern. A new climate feedback analysis method is used to isolate the surface warming or cooling contributions of both radiative and non-radiative (dynamical) climate feedbacks to the total (actual) surface temperature change given by the CCSM4. These contributions (or partial surface temperature changes) are additive and their total is approximately equal to the actual surface temperature change. What is found is that the effects of CO2 doubling alone warms the surface throughout with a maximum in polar regions, which indicates the CO2 forcing alone has a degree of polar warming amplification. Water vapor feedback is a positive feedback throughout but is most responsible for the surface warming found in the tropics. Polar warming amplification is found to be strongest away from summer (especially in NH), which is primarily caused by a positive feedback due to cloud feedbacks but with the surface temperature change due to the CO2 forcing alone and the ocean dynamics and storage feedback also playing an important role. Contrary to popular belief, surface albedo feedback (SAF) does not account for much of the polar amplification. SAF tries to amplify polar warming, but in summer. No major polar amplification is seen in summer for the actual surface temperature, so SAF is not the feedback responsible for polar amplification. This is actually a consequence of the ocean dynamics and storage feedback, which negates the effects of SAF to a large degree.

Compressed multi-block local binary pattern for object tracking

NASA Astrophysics Data System (ADS)

Li, Tianwen; Gao, Yun; Zhao, Lei; Zhou, Hao

2018-04-01

Both robustness and real-time are very important for the application of object tracking under a real environment. The focused trackers based on deep learning are difficult to satisfy with the real-time of tracking. Compressive sensing provided a technical support for real-time tracking. In this paper, an object can be tracked via a multi-block local binary pattern feature. The feature vector was extracted based on the multi-block local binary pattern feature, which was compressed via a sparse random Gaussian matrix as the measurement matrix. The experiments showed that the proposed tracker ran in real-time and outperformed the existed compressive trackers based on Haar-like feature on many challenging video sequences in terms of accuracy and robustness.

Automated Image Registration Using Morphological Region of Interest Feature Extraction

NASA Technical Reports Server (NTRS)

Plaza, Antonio; LeMoigne, Jacqueline; Netanyahu, Nathan S.

2005-01-01

With the recent explosion in the amount of remotely sensed imagery and the corresponding interest in temporal change detection and modeling, image registration has become increasingly important as a necessary first step in the integration of multi-temporal and multi-sensor data for applications such as the analysis of seasonal and annual global climate changes, as well as land use/cover changes. The task of image registration can be divided into two major components: (1) the extraction of control points or features from images; and (2) the search among the extracted features for the matching pairs that represent the same feature in the images to be matched. Manual control feature extraction can be subjective and extremely time consuming, and often results in few usable points. Automated feature extraction is a solution to this problem, where desired target features are invariant, and represent evenly distributed landmarks such as edges, corners and line intersections. In this paper, we develop a novel automated registration approach based on the following steps. First, a mathematical morphology (MM)-based method is used to obtain a scale-orientation morphological profile at each image pixel. Next, a spectral dissimilarity metric such as the spectral information divergence is applied for automated extraction of landmark chips, followed by an initial approximate matching. This initial condition is then refined using a hierarchical robust feature matching (RFM) procedure. Experimental results reveal that the proposed registration technique offers a robust solution in the presence of seasonal changes and other interfering factors. Keywords-Automated image registration, multi-temporal imagery, mathematical morphology, robust feature matching.

A wireless modular multi-modal multi-node patch platform for robust biosignal monitoring.

PubMed

Pantelopoulos, Alexandros; Saldivar, Enrique; Roham, Masoud

2011-01-01

In this paper a wireless modular, multi-modal, multi-node patch platform is described. The platform comprises low-cost semi-disposable patch design aiming at unobtrusive ambulatory monitoring of multiple physiological parameters. Owing to its modular design it can be interfaced with various low-power RF communication and data storage technologies, while the data fusion of multi-modal and multi-node features facilitates measurement of several biosignals from multiple on-body locations for robust feature extraction. Preliminary results of the patch platform are presented which illustrate the capability to extract respiration rate from three different independent metrics, which combined together can give a more robust estimate of the actual respiratory rate.

Feature selection methods for object-based classification of sub-decimeter resolution digital aerial imagery

USDA-ARS?s Scientific Manuscript database

Due to the availability of numerous spectral, spatial, and contextual features, the determination of optimal features and class separabilities can be a time consuming process in object-based image analysis (OBIA). While several feature selection methods have been developed to assist OBIA, a robust c...

Vehicle logo recognition using multi-level fusion model

NASA Astrophysics Data System (ADS)

Ming, Wei; Xiao, Jianli

2018-04-01

Vehicle logo recognition plays an important role in manufacturer identification and vehicle recognition. This paper proposes a new vehicle logo recognition algorithm. It has a hierarchical framework, which consists of two fusion levels. At the first level, a feature fusion model is employed to map the original features to a higher dimension feature space. In this space, the vehicle logos become more recognizable. At the second level, a weighted voting strategy is proposed to promote the accuracy and the robustness of the recognition results. To evaluate the performance of the proposed algorithm, extensive experiments are performed, which demonstrate that the proposed algorithm can achieve high recognition accuracy and work robustly.

Software For Least-Squares And Robust Estimation

NASA Technical Reports Server (NTRS)

Jeffreys, William H.; Fitzpatrick, Michael J.; Mcarthur, Barbara E.; Mccartney, James

1990-01-01

GAUSSFIT computer program includes full-featured programming language facilitating creation of mathematical models solving least-squares and robust-estimation problems. Programming language designed to make it easy to specify complex reduction models. Written in 100 percent C language.

Surfers ankle: a bony spur of the talar neck

PubMed Central

Brooks, Francis Michael; Williams, Paul; Carpenter, E C

2009-01-01

A 27-year-old competitive surfer presented with a history of a painful right ankle. He was able to recall an injury to his right ankle 4–5 years previously, sustained while surfing. The mechanism described was that he had dropped a considerable height during take-off, sustaining an impact injury from the board. He recalled immediate pain and swelling followed by 2–3 weeks of pain and a limp; he continued to surf, albeit with difficulty, despite this. Investigations found him to have a bony spur on the anterolateral part of the talus. This case shows how this injury is similar to those observed in other sports. PMID:21709829

Health issues for surfers.

PubMed

Zoltan, Todd B; Taylor, Kenneth S; Achar, Suraj A

2005-06-15

Surfers are prone to acute injuries as well as conditions resulting from chronic environmental exposure. Sprains, lacerations, strains, and fractures are the most common types of trauma. Injury from the rider's own surfboard may be the prevailing mechanism. Minor wound infections can be treated on an outpatient basis with ciprofloxacin or trimethoprim-sulfamethoxazole. Jellyfish stings are common and may be treated with heat application. Other treatment regimens have had mixed results. Seabather's eruption is a pruritic skin reaction caused by exposure to nematocyst-containing coelenterate larvae. Additional surfing hazards include stingrays, coral reefs, and, occasionally, sharks. Otologic sequelae of surfing include auditory exostoses, tympanic membrane rupture, and otitis externa. Sun exposure and skin cancer risk are inherent dangers of this sport.

General Multivariate Linear Modeling of Surface Shapes Using SurfStat

PubMed Central

Chung, Moo K.; Worsley, Keith J.; Nacewicz, Brendon, M.; Dalton, Kim M.; Davidson, Richard J.

2010-01-01

Although there are many imaging studies on traditional ROI-based amygdala volumetry, there are very few studies on modeling amygdala shape variations. This paper present a unified computational and statistical framework for modeling amygdala shape variations in a clinical population. The weighted spherical harmonic representation is used as to parameterize, to smooth out, and to normalize amygdala surfaces. The representation is subsequently used as an input for multivariate linear models accounting for nuisance covariates such as age and brain size difference using SurfStat package that completely avoids the complexity of specifying design matrices. The methodology has been applied for quantifying abnormal local amygdala shape variations in 22 high functioning autistic subjects. PMID:20620211

Delamination-restacking behaviour of surfactant intercalated layered hydroxy double salts, M 3Zn 2(OH) 8(surf) 2ṡ2H 2O [M = Ni, Co and surf = dodecyl sulphate (DS), dodecyl benzene sulphonate (DBS)

NASA Astrophysics Data System (ADS)

Rajamathi, Jacqueline T.; Ravishankar, N.; Rajamathi, Michael

2005-02-01

Surfactant anion intercalated nickel-zinc and cobalt-zinc layered hydroxy double salts were prepared through a modified acetate hydrolysis route. These organo-inorganic hybrids delaminate readily in alcohols such as 1-butanol to give stable translucent colloids. The extent of delamination and the stability of the colloids obtained are comparable to what has been observed in the case of layered double hydroxides (LDHs). The original layered solid could be obtained either by evaporation of the colloid or precipitation by the addition of a polar solvent such as acetone.

Modification of Surf Zone Turbulence and the Undertow by a Submerged Canopy

NASA Astrophysics Data System (ADS)

Mandel, T.; Koseff, J. R.; Rosenzweig, I.; Suckale, J.; Zarama, F. J.

2016-02-01

As sea level rise and stronger storm events threaten our coastlines, coastal vegetation has come under consideration as a potentially resilient, financially viable tool to mitigate flooding and erosion. However, the actual role of this "green infrastructure" in the near-shore region is not fully understood. In order to evaluate the role of vegetation in coastal protection, a series of experiments were conducted in a simulated laboratory surf zone. We examine the impact of canopy location and submergence on the undertow profile, turbulent kinetic energy, and Reynolds stress for varying Reynolds number and Keulegan-Carpenter number, and compare these results to theoretical formulations that utilize a depth-averaged undertow and highly simplified eddy viscosity.

Status of the LBNF Cryogenic System

DOE PAGES

Montanari, D.; Adamowski, M.; Bremer, J.; ...

2017-12-30

We present that the Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 tons of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An internationalmore » engineering team will design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the modes of operations, layout and main features of the LBNF cryogenic system. Lastly, the expected performance, the functional requirements and the status of the design are also highlighted.« less

Status of the LBNF Cryogenic System

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

Montanari, D.; Adamowski, M.; Bremer, J.

We present that the Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 tons of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An internationalmore » engineering team will design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the modes of operations, layout and main features of the LBNF cryogenic system. Lastly, the expected performance, the functional requirements and the status of the design are also highlighted.« less

Status of the LBNF Cryogenic System

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

Montanari, D.; Adamowski, M.; Bremer, J.

2017-01-01

The Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 ton of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An international engineering team willmore » design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the models of operations, layout and main features of the LBNF cryogenic system. The expected performance, the functional requirements and the status of the design are also highlighted.« less

Status of the LBNF Cryogenic System

NASA Astrophysics Data System (ADS)

Montanari, D.; Adamowski, M.; Bremer, J.; Delaney, M.; Diaz, A.; Doubnik, R.; Haaf, K.; Hentschel, S.; Norris, B.; Voirin, E.

2017-12-01

The Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 tons of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An international engineering team will design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the modes of operations, layout and main features of the LBNF cryogenic system. The expected performance, the functional requirements and the status of the design are also highlighted.

Robust spike classification based on frequency domain neural waveform features.

PubMed

Yang, Chenhui; Yuan, Yuan; Si, Jennie

2013-12-01

We introduce a new spike classification algorithm based on frequency domain features of the spike snippets. The goal for the algorithm is to provide high classification accuracy, low false misclassification, ease of implementation, robustness to signal degradation, and objectivity in classification outcomes. In this paper, we propose a spike classification algorithm based on frequency domain features (CFDF). It makes use of frequency domain contents of the recorded neural waveforms for spike classification. The self-organizing map (SOM) is used as a tool to determine the cluster number intuitively and directly by viewing the SOM output map. After that, spike classification can be easily performed using clustering algorithms such as the k-Means. In conjunction with our previously developed multiscale correlation of wavelet coefficient (MCWC) spike detection algorithm, we show that the MCWC and CFDF detection and classification system is robust when tested on several sets of artificial and real neural waveforms. The CFDF is comparable to or outperforms some popular automatic spike classification algorithms with artificial and real neural data. The detection and classification of neural action potentials or neural spikes is an important step in single-unit-based neuroscientific studies and applications. After the detection of neural snippets potentially containing neural spikes, a robust classification algorithm is applied for the analysis of the snippets to (1) extract similar waveforms into one class for them to be considered coming from one unit, and to (2) remove noise snippets if they do not contain any features of an action potential. Usually, a snippet is a small 2 or 3 ms segment of the recorded waveform, and differences in neural action potentials can be subtle from one unit to another. Therefore, a robust, high performance classification system like the CFDF is necessary. In addition, the proposed algorithm does not require any assumptions on statistical properties of the noise and proves to be robust under noise contamination.

Registration using natural features for augmented reality systems.

PubMed

Yuan, M L; Ong, S K; Nee, A Y C

2006-01-01

Registration is one of the most difficult problems in augmented reality (AR) systems. In this paper, a simple registration method using natural features based on the projective reconstruction technique is proposed. This method consists of two steps: embedding and rendering. Embedding involves specifying four points to build the world coordinate system on which a virtual object will be superimposed. In rendering, the Kanade-Lucas-Tomasi (KLT) feature tracker is used to track the natural feature correspondences in the live video. The natural features that have been tracked are used to estimate the corresponding projective matrix in the image sequence. Next, the projective reconstruction technique is used to transfer the four specified points to compute the registration matrix for augmentation. This paper also proposes a robust method for estimating the projective matrix, where the natural features that have been tracked are normalized (translation and scaling) and used as the input data. The estimated projective matrix will be used as an initial estimate for a nonlinear optimization method that minimizes the actual residual errors based on the Levenberg-Marquardt (LM) minimization method, thus making the results more robust and stable. The proposed registration method has three major advantages: 1) It is simple, as no predefined fiducials or markers are used for registration for either indoor and outdoor AR applications. 2) It is robust, because it remains effective as long as at least six natural features are tracked during the entire augmentation, and the existence of the corresponding projective matrices in the live video is guaranteed. Meanwhile, the robust method to estimate the projective matrix can obtain stable results even when there are some outliers during the tracking process. 3) Virtual objects can still be superimposed on the specified areas, even if some parts of the areas are occluded during the entire process. Some indoor and outdoor experiments have been conducted to validate the performance of this proposed method.

Robustly Aligning a Shape Model and Its Application to Car Alignment of Unknown Pose.

PubMed

Li, Yan; Gu, Leon; Kanade, Takeo

2011-09-01

Precisely localizing in an image a set of feature points that form a shape of an object, such as car or face, is called alignment. Previous shape alignment methods attempted to fit a whole shape model to the observed data, based on the assumption of Gaussian observation noise and the associated regularization process. However, such an approach, though able to deal with Gaussian noise in feature detection, turns out not to be robust or precise because it is vulnerable to gross feature detection errors or outliers resulting from partial occlusions or spurious features from the background or neighboring objects. We address this problem by adopting a randomized hypothesis-and-test approach. First, a Bayesian inference algorithm is developed to generate a shape-and-pose hypothesis of the object from a partial shape or a subset of feature points. For alignment, a large number of hypotheses are generated by randomly sampling subsets of feature points, and then evaluated to find the one that minimizes the shape prediction error. This method of randomized subset-based matching can effectively handle outliers and recover the correct object shape. We apply this approach on a challenging data set of over 5,000 different-posed car images, spanning a wide variety of car types, lighting, background scenes, and partial occlusions. Experimental results demonstrate favorable improvements over previous methods on both accuracy and robustness.

Robust Classification and Segmentation of Planar and Linear Features for Construction Site Progress Monitoring and Structural Dimension Compliance Control

NASA Astrophysics Data System (ADS)

Maalek, R.; Lichti, D. D.; Ruwanpura, J.

2015-08-01

The application of terrestrial laser scanners (TLSs) on construction sites for automating construction progress monitoring and controlling structural dimension compliance is growing markedly. However, current research in construction management relies on the planned building information model (BIM) to assign the accumulated point clouds to their corresponding structural elements, which may not be reliable in cases where the dimensions of the as-built structure differ from those of the planned model and/or the planned model is not available with sufficient detail. In addition outliers exist in construction site datasets due to data artefacts caused by moving objects, occlusions and dust. In order to overcome the aforementioned limitations, a novel method for robust classification and segmentation of planar and linear features is proposed to reduce the effects of outliers present in the LiDAR data collected from construction sites. First, coplanar and collinear points are classified through a robust principal components analysis procedure. The classified points are then grouped using a robust clustering method. A method is also proposed to robustly extract the points belonging to the flat-slab floors and/or ceilings without performing the aforementioned stages in order to preserve computational efficiency. The applicability of the proposed method is investigated in two scenarios, namely, a laboratory with 30 million points and an actual construction site with over 150 million points. The results obtained by the two experiments validate the suitability of the proposed method for robust segmentation of planar and linear features in contaminated datasets, such as those collected from construction sites.

Preventing Shoulder-Surfing Attack with the Concept of Concealing the Password Objects' Information

PubMed Central

Ho, Peng Foong; Kam, Yvonne Hwei-Syn; Wee, Mee Chin

2014-01-01

Traditionally, picture-based password systems employ password objects (pictures/icons/symbols) as input during an authentication session, thus making them vulnerable to “shoulder-surfing” attack because the visual interface by function is easily observed by others. Recent software-based approaches attempt to minimize this threat by requiring users to enter their passwords indirectly by performing certain mental tasks to derive the indirect password, thus concealing the user's actual password. However, weaknesses in the positioning of distracter and password objects introduce usability and security issues. In this paper, a new method, which conceals information about the password objects as much as possible, is proposed. Besides concealing the password objects and the number of password objects, the proposed method allows both password and distracter objects to be used as the challenge set's input. The correctly entered password appears to be random and can only be derived with the knowledge of the full set of password objects. Therefore, it would be difficult for a shoulder-surfing adversary to identify the user's actual password. Simulation results indicate that the correct input object and its location are random for each challenge set, thus preventing frequency of occurrence analysis attack. User study results show that the proposed method is able to prevent shoulder-surfing attack. PMID:24991649

Room temperature deposition of gold onto the diffuse and sharp diffraction spot Si(111)-( 3 × 3) R30° Au surfaces

NASA Astrophysics Data System (ADS)

Plass, Richard; Marks, Laurence D.

1996-06-01

Room temperature gold depositions onto Si(111)-( 3 × 3) R30° Au surfaces with diffuse and sharp diffraction spots [Surf. Sci. 242 (1991) 73] (diffuse and sharp 3 × 3 Au hereafter) under UHV conditions has been monitored using transmission electron diffraction (TED). Both systems display an increase in surface structure diffraction spot intensities up to the completion of 1.0 monolayer (ML) after which the surface beams display an exponential decrease in intensity with coverage. The exponential decay rate decreases after roughly 1.33 ML. These results can be attributed to gold initially diffusing to and filling 3 × 3 Au gold trimer sites in vacancy type surface domain walls [Surf. Sci. 342 (1995) 233], then filling one of three possible sites on the 3 × 3 Au structure with essentially no surface diffusion, disrupting nearby gold trimers. Gold deposition onto the diffuse type structure caused the formation and expansion of satellite arcs around the strongest 3 × 3 beams similar to those seen by others [Surf. Sci. 242 (1991) 73; Jpn. J. Appl. Phys. 16 (1977) 891; J. Vac. Sci. Technol. A 10 (1992) 3486] at elevated temperatures while the sharp structure displayed only a modest shoulder formation near the strongest 3 × 3 beams.

Advancements in non-contact metrology of asphere and diffractive optics

NASA Astrophysics Data System (ADS)

DeFisher, Scott

2017-11-01

Advancements in optical manufacturing technology allow optical designers to implement steep aspheric or high departure surfaces into their systems. Measuring these surfaces with profilometers or CMMs can be difficult due to large surface slopes or sharp steps in the surface. OptiPro has developed UltraSurf to qualify the form and figure of steep aspheric and diffractive optics. UltraSurf is a computer controlled, non-contact coordinate measuring machine. It incorporates five air-bearing axes, linear motors, high-resolution feedback, and a non-contact probe. The measuring probe is scanned over the optical surface while maintaining perpendicularity and a constant focal offset. Multiple probe technologies are available on UltraSurf. Each probe has strengths and weaknesses relative to the material properties, surface finish, and figure error of an optical component. The measuring probes utilize absolute distance to resolve step heights and diffractive surface patterns. The non-contact scanning method avoids common pitfalls with stylus contact instruments. Advancements in measuring speed and precision has enabled fast and accurate non-contact metrology of diffractive and steep aspheric surfaces. The benefits of data sampling with twodimensional profiles and three-dimensional topography maps will be presented. In addition, accuracy, repeatability, and machine qualification will be discussed with regards to aspheres and diffractive surfaces.

Robust Tomato Recognition for Robotic Harvesting Using Feature Images Fusion

PubMed Central

Zhao, Yuanshen; Gong, Liang; Huang, Yixiang; Liu, Chengliang

2016-01-01

Automatic recognition of mature fruits in a complex agricultural environment is still a challenge for an autonomous harvesting robot due to various disturbances existing in the background of the image. The bottleneck to robust fruit recognition is reducing influence from two main disturbances: illumination and overlapping. In order to recognize the tomato in the tree canopy using a low-cost camera, a robust tomato recognition algorithm based on multiple feature images and image fusion was studied in this paper. Firstly, two novel feature images, the  a*-component image and the I-component image, were extracted from the L*a*b* color space and luminance, in-phase, quadrature-phase (YIQ) color space, respectively. Secondly, wavelet transformation was adopted to fuse the two feature images at the pixel level, which combined the feature information of the two source images. Thirdly, in order to segment the target tomato from the background, an adaptive threshold algorithm was used to get the optimal threshold. The final segmentation result was processed by morphology operation to reduce a small amount of noise. In the detection tests, 93% target tomatoes were recognized out of 200 overall samples. It indicates that the proposed tomato recognition method is available for robotic tomato harvesting in the uncontrolled environment with low cost. PMID:26840313

Robust feature tracking for endoscopic pose estimation and structure recovery

NASA Astrophysics Data System (ADS)

Speidel, S.; Krappe, S.; Röhl, S.; Bodenstedt, S.; Müller-Stich, B.; Dillmann, R.

2013-03-01

Minimally invasive surgery is a highly complex medical discipline with several difficulties for the surgeon. To alleviate these difficulties, augmented reality can be used for intraoperative assistance. For visualization, the endoscope pose must be known which can be acquired with a SLAM (Simultaneous Localization and Mapping) approach using the endoscopic images. In this paper we focus on feature tracking for SLAM in minimally invasive surgery. Robust feature tracking and minimization of false correspondences is crucial for localizing the endoscope. As sensory input we use a stereo endoscope and evaluate different feature types in a developed SLAM framework. The accuracy of the endoscope pose estimation is validated with synthetic and ex vivo data. Furthermore we test the approach with in vivo image sequences from da Vinci interventions.

Chinese License Plates Recognition Method Based on A Robust and Efficient Feature Extraction and BPNN Algorithm

NASA Astrophysics Data System (ADS)

Zhang, Ming; Xie, Fei; Zhao, Jing; Sun, Rui; Zhang, Lei; Zhang, Yue

2018-04-01

The prosperity of license plate recognition technology has made great contribution to the development of Intelligent Transport System (ITS). In this paper, a robust and efficient license plate recognition method is proposed which is based on a combined feature extraction model and BPNN (Back Propagation Neural Network) algorithm. Firstly, the candidate region of the license plate detection and segmentation method is developed. Secondly, a new feature extraction model is designed considering three sets of features combination. Thirdly, the license plates classification and recognition method using the combined feature model and BPNN algorithm is presented. Finally, the experimental results indicate that the license plate segmentation and recognition both can be achieved effectively by the proposed algorithm. Compared with three traditional methods, the recognition accuracy of the proposed method has increased to 95.7% and the consuming time has decreased to 51.4ms.

A comparison of three feature selection methods for object-based classification of sub-decimeter resolution UltraCam-L imagery

USDA-ARS?s Scientific Manuscript database

The availability of numerous spectral, spatial, and contextual features with object-based image analysis (OBIA) renders the selection of optimal features a time consuming and subjective process. While several feature election methods have been used in conjunction with OBIA, a robust comparison of th...

Nearshore Coastal Dynamics on a Sea-Breeze Dominated Micro-Tidal Beach (NCSAL)

NASA Astrophysics Data System (ADS)

Torres-Freyermuth, A.; Puleo, J. A.; Ruiz de Alegría-Arzaburu, A.; Figlus, J.; Mendoza, T.; Pintado-Patino, J. C.; Pieterse, A.; Chardon-Maldonado, P.; DiCosmo, N. R.; Wellman, N.; Garcia-Nava, H.; Palemón-Arcos, L.; Roberts, T.; López-González, J.; Bravo, M.; Ojeda, E.; Medellín, G.; Appendini, C. M.; Figueroa, B.; González-Leija, M.; Enriquez, C.; Pedrozo-Acuña, A.; Salles, P.

2014-12-01

A comprehensive field experiment devoted to the study of coastal processes on a micro-tidal beach was conducted from March 30th to April 12th 2014 in Sisal, Yucatán México. Wave conditions in the study area are controlled by local (i.e., sea-breezes) and meso-scale (i.e., Nortes) meteorological events. Simultaneous measurements of waves, tides, winds, currents, sediment transport, runup, and beach morphology were obtained in this experiment. Very dense nearshore instrumentation arrays allow us the study of the cross-/along- shore variability of surf/swash zone dynamics during different forcing conditions. Strong sea-breeze wind events produced a diurnal cycle with a maximum wind speed of 14 m/s. The persistent sea-breeze system forces small-amplitude (Hs<1 m) short-period (Tp<4 s) NE waves approaching with a high incidence wave angle. These wave conditions drive westward alongshore currents of up to 0.6 m/s in the inner surf zone and hence produce an active sediment transport in the swash zone. On the other hand, the more energetic (Hs>1 m) Norte event, lasting 48 hours, reached the coast on April 8th generating a long-period swell (Tp>10 s) arriving from the NNW. This event induced an eastward net sediment transport across a wide surf zone. However, long-term observations of sand impoundment at a groin located near the study area suggests that the net sediment transport in the northern Yucatan peninsula is controlled by sea-breeze events and hence swash zone dynamics play an important role in the net sediment budget of this region. A comparative study of surf and swash zone dynamics during both sea-breeze and Norte events will be presented. The Institute of Engineering of UNAM, throughout an International Collaborative Project with the University of Delaware, and CONACYT (CB-167692) provided financial support. The first author acknowledges ONR Global for providing financial support throughout the Visiting Scientist Program.

sUAS for Rapid Pre-Storm Coastal Characterization and Vulnerability Assessment

NASA Astrophysics Data System (ADS)

Brodie, K. L.; Slocum, R. K.; Spore, N.

2015-12-01

Open coast beaches and surf-zones are dynamic three-dimensional environments that can evolve rapidly on the time-scale of hours in response to changing environmental conditions. Up-to-date knowledge about the pre-storm morphology of the coast can be instrumental in making accurate predictions about coastal change and damage during large storms like Hurricanes and Nor'Easters. For example, alongshore variations in the shape of ephemeral sandbars along the coastline can focus wave energy, subjecting different stretches of coastline to significantly higher waves. Variations in beach slope and width can also alter wave runup, causing higher wave-induced water levels which can cause overwash or inlet breaching. Small Unmanned Aerial Systems (sUAS) offer a new capability to rapidly and inexpensively map vulnerable coastlines in advance of approaching storms. Here we present results from a prototype system that maps coastal topography and surf-zone morphology utilizing a multi-camera sensor. Structure-from-motion algorithms are used to generate topography and also constrain the trajectory of the sUAS. These data, in combination with mount boresight information, are used to rectify images from ocean-facing cameras. Images from all cameras are merged to generate a wide field of view allowing up to 5 minutes of continuous imagery time-series to be collected as the sUAS transits the coastline. Water imagery is then analyzed using wave-kinematics algorithms to provide information on surf-zone bathymetry. To assess this methodology, the absolute and relative accuracy of topographic data are evaluated in relation to simultaneously collected terrestrial lidar data. Ortho-rectification of water imagery is investigated using visible fixed targets installed in the surf-zone, and through comparison to stationary tower-based imagery. Future work will focus on evaluating how topographic and bathymetric data from this sUAS approach can be used to update forcing parameters in both empirical and numerical models predicting coast inundation and erosion in advance of storms.

Physical factors influencing immature-fish communities in the surf zones of sandy beaches in northwestern Kyushu Island, Japan

NASA Astrophysics Data System (ADS)

Inui, Ryutei; Nishida, Takashi; Onikura, Norio; Eguchi, Katsuhisa; Kawagishi, Motoyoshi; Nakatani, Masaya; Oikawa, Shin

2010-02-01

We aim to understand the relationships between physical conditions and characteristics of the immature-fish community in surf zones of sandy beaches. Therefore, we obtained fish samples between March 2007 and February 2008 and analyzed certain physical conditions in the surf zones of 21 sandy beaches on the coastline of the northwestern Kyushu Island, Japan. We collected a total of 83 species and 6458 immature individuals. In a BIO-ENV analysis, the highest correlation was observed between fish assemblage and S20 (i.e., the slope from the shoreline to the sites where the depth was 20 m) and current velocity (CV) values. Stepwise multiple linear regression analyses revealed that the number of species and individuals decrease with an increase in the S20 and CV values. These results show that species richness and the abundance of immature-fish increase under shelving and calm conditions. Thus, immature-fish assemblages are strongly influenced by the prevailing physical conditions. Moreover, in six of the 10 dominant species, a negative correlation was observed between CV and abundance. On the other hand, S20 was found to be the explanatory variable only in the case of the most dominant species, i.e., Gymnogobius breunigii. Furthermore, a positive correlation was observed between S1 (i.e., the slope from the shoreline to the sites where the depth was 1.0 m at the mean tidal level) and median particle size (i.e., MPS of the sediments) and the abundances of Sillago japonica and Favonigobius gymnauchen, respectively, and a negative correlation with salinity, in the case of Acanthogobius lactipes. We conclude that the characteristics of the fish community in surf zones on sandy beaches are determined by not only the shelving and calm conditions, which influence fish assemblages and abundances, but also the habitat diversity, which influences the diversity of fish species.

a Robust Descriptor Based on Spatial and Frequency Structural Information for Visible and Thermal Infrared Image Matching

NASA Astrophysics Data System (ADS)

Fu, Z.; Qin, Q.; Wu, C.; Chang, Y.; Luo, B.

2017-09-01

Due to the differences of imaging principles, image matching between visible and thermal infrared images still exist new challenges and difficulties. Inspired by the complementary spatial and frequency information of geometric structural features, a robust descriptor is proposed for visible and thermal infrared images matching. We first divide two different spatial regions to the region around point of interest, using the histogram of oriented magnitudes, which corresponds to the 2-D structural shape information to describe the larger region and the edge oriented histogram to describe the spatial distribution for the smaller region. Then the two vectors are normalized and combined to a higher feature vector. Finally, our proposed descriptor is obtained by applying principal component analysis (PCA) to reduce the dimension of the combined high feature vector to make our descriptor more robust. Experimental results showed that our proposed method was provided with significant improvements in correct matching numbers and obvious advantages by complementing information within spatial and frequency structural information.

The Speech multi features fusion perceptual hash algorithm based on tensor decomposition

NASA Astrophysics Data System (ADS)

Huang, Y. B.; Fan, M. H.; Zhang, Q. Y.

2018-03-01

With constant progress in modern speech communication technologies, the speech data is prone to be attacked by the noise or maliciously tampered. In order to make the speech perception hash algorithm has strong robustness and high efficiency, this paper put forward a speech perception hash algorithm based on the tensor decomposition and multi features is proposed. This algorithm analyses the speech perception feature acquires each speech component wavelet packet decomposition. LPCC, LSP and ISP feature of each speech component are extracted to constitute the speech feature tensor. Speech authentication is done by generating the hash values through feature matrix quantification which use mid-value. Experimental results showing that the proposed algorithm is robust for content to maintain operations compared with similar algorithms. It is able to resist the attack of the common background noise. Also, the algorithm is highly efficiency in terms of arithmetic, and is able to meet the real-time requirements of speech communication and complete the speech authentication quickly.