WorldWideScience

Sample records for single-perspective pose estimation

  1. A New Pose Estimation Algorithm Using a Perspective-Ray-Based Scaled Orthographic Projection with Iteration.

    Directory of Open Access Journals (Sweden)

    Pengfei Sun

    Full Text Available Pose estimation aims at measuring the position and orientation of a calibrated camera using known image features. The pinhole model is the dominant camera model in this field. However, the imaging precision of this model is not accurate enough for an advanced pose estimation algorithm. In this paper, a new camera model, called incident ray tracking model, is introduced. More importantly, an advanced pose estimation algorithm based on the perspective ray in the new camera model, is proposed. The perspective ray, determined by two positioning points, is an abstract mathematical equivalent of the incident ray. In the proposed pose estimation algorithm, called perspective-ray-based scaled orthographic projection with iteration (PRSOI, an approximate ray-based projection is calculated by a linear system and refined by iteration. Experiments on the PRSOI have been conducted, and the results demonstrate that it is of high accuracy in the six degrees of freedom (DOF motion. And it outperforms three other state-of-the-art algorithms in terms of accuracy during the contrast experiment.

  2. Multi-view 3D human pose estimation combining single-frame recovery, temporal integration and model adaptation

    NARCIS (Netherlands)

    Hofmann, K.M.; Gavrilla, D.M.

    2009-01-01

    We present a system for the estimation of unconstrained 3D human upper body movement from multiple cameras. Its main novelty lies in the integration of three components: single frame pose recovery, temporal integration and model adaptation. Single frame pose recovery consists of a hypothesis

  3. Multi-view 3D Human Pose Estimation in Complex Environment

    NARCIS (Netherlands)

    Hofmann, K.M.; Gavrila, D.M.

    2012-01-01

    We introduce a framework for unconstrained 3D human upper body pose estimation from multiple camera views in complex environment. Its main novelty lies in the integration of three components: single-frame pose recovery, temporal integration and model texture adaptation. Single-frame pose recovery

  4. Single-frame 3D human pose recovery from multiple views

    NARCIS (Netherlands)

    Hofmann, M.; Gavrila, D.M.

    2009-01-01

    We present a system for the estimation of unconstrained 3D human upper body pose from multi-camera single-frame views. Pose recovery starts with a shape detection stage where candidate poses are generated based on hierarchical exemplar matching in the individual camera views. The hierarchy used in

  5. Fast human pose estimation using 3D Zernike descriptors

    Science.gov (United States)

    Berjón, Daniel; Morán, Francisco

    2012-03-01

    Markerless video-based human pose estimation algorithms face a high-dimensional problem that is frequently broken down into several lower-dimensional ones by estimating the pose of each limb separately. However, in order to do so they need to reliably locate the torso, for which they typically rely on time coherence and tracking algorithms. Their losing track usually results in catastrophic failure of the process, requiring human intervention and thus precluding their usage in real-time applications. We propose a very fast rough pose estimation scheme based on global shape descriptors built on 3D Zernike moments. Using an articulated model that we configure in many poses, a large database of descriptor/pose pairs can be computed off-line. Thus, the only steps that must be done on-line are the extraction of the descriptors for each input volume and a search against the database to get the most likely poses. While the result of such process is not a fine pose estimation, it can be useful to help more sophisticated algorithms to regain track or make more educated guesses when creating new particles in particle-filter-based tracking schemes. We have achieved a performance of about ten fps on a single computer using a database of about one million entries.

  6. Tridimensional pose estimation of a person head

    International Nuclear Information System (INIS)

    Perez Berenguer, Elisa; Soria, Carlos; Nasisi, Oscar; Mut, Vicente

    2007-01-01

    In this work, we present a method for estimating 3-D motion parameters; this method provides an alternative way for 3D head pose estimation from image sequence in the current computer vision literature. This method is robust over extended sequences and large head motions and accurately extracts the orientation angles of head from a single view. Experimental results show that this tracking system works well for development a human-computer interface for people that possess severe motor incapacity

  7. Statistical Model-Based Face Pose Estimation

    Institute of Scientific and Technical Information of China (English)

    GE Xinliang; YANG Jie; LI Feng; WANG Huahua

    2007-01-01

    A robust face pose estimation approach is proposed by using face shape statistical model approach and pose parameters are represented by trigonometric functions. The face shape statistical model is firstly built by analyzing the face shapes from different people under varying poses. The shape alignment is vital in the process of building the statistical model. Then, six trigonometric functions are employed to represent the face pose parameters. Lastly, the mapping function is constructed between face image and face pose by linearly relating different parameters. The proposed approach is able to estimate different face poses using a few face training samples. Experimental results are provided to demonstrate its efficiency and accuracy.

  8. Real-Time Head Pose Estimation on Mobile Platforms

    Directory of Open Access Journals (Sweden)

    Jianfeng Ren

    2010-06-01

    Full Text Available Many computer vision applications such as augmented reality require head pose estimation. As far as the real-time implementation of head pose estimation on relatively resource limited mobile platforms is concerned, it is required to satisfy real-time constraints while maintaining reasonable head pose estimation accuracy. The introduced head pose estimation approach in this paper is an attempt to meet this objective. The approach consists of the following components: Viola-Jones face detection, color-based face tracking using an online calibration procedure, and head pose estimation using Hu moment features and Fisher linear discriminant. Experimental results running on an actual mobile device are reported exhibiting both the real- time and accuracy aspects of the developed approach.

  9. Head pose estimation algorithm based on deep learning

    Science.gov (United States)

    Cao, Yuanming; Liu, Yijun

    2017-05-01

    Head pose estimation has been widely used in the field of artificial intelligence, pattern recognition and intelligent human-computer interaction and so on. Good head pose estimation algorithm should deal with light, noise, identity, shelter and other factors robustly, but so far how to improve the accuracy and robustness of attitude estimation remains a major challenge in the field of computer vision. A method based on deep learning for pose estimation is presented. Deep learning with a strong learning ability, it can extract high-level image features of the input image by through a series of non-linear operation, then classifying the input image using the extracted feature. Such characteristics have greater differences in pose, while they are robust of light, identity, occlusion and other factors. The proposed head pose estimation is evaluated on the CAS-PEAL data set. Experimental results show that this method is effective to improve the accuracy of pose estimation.

  10. Pose Estimation of Interacting People using Pictorial Structures

    DEFF Research Database (Denmark)

    Fihl, Preben; Moeslund, Thomas B.

    2010-01-01

    Pose estimation of people have had great progress in recent years but so far research has dealt with single persons. In this paper we address some of the challenges that arise when doing pose estimation of interacting people. We build on the pictorial structures framework and make important...... contributions by combining color-based appearance and edge information using a measure of the local quality of the appearance feature. In this way we not only combine the two types of features but dynamically find the optimal weighting of them. We further enable the method to handle occlusions by searching...... a foreground mask for possible occluded body parts and then applying extra strong kinematic constraints to find the true occluded body parts. The effect of applying our two contributions are show through both qualitative and quantitative tests and show a clear improvement on the ability to correctly localize...

  11. Coupled multiview autoencoders with locality sensitivity for three-dimensional human pose estimation

    Science.gov (United States)

    Yu, Jialin; Sun, Jifeng; Luo, Shasha; Duan, Bichao

    2017-09-01

    Estimating three-dimensional (3D) human poses from a single camera is usually implemented by searching pose candidates with image descriptors. Existing methods usually suppose that the mapping from feature space to pose space is linear, but in fact, their mapping relationship is highly nonlinear, which heavily degrades the performance of 3D pose estimation. We propose a method to recover 3D pose from a silhouette image. It is based on the multiview feature embedding (MFE) and the locality-sensitive autoencoders (LSAEs). On the one hand, we first depict the manifold regularized sparse low-rank approximation for MFE and then the input image is characterized by a fused feature descriptor. On the other hand, both the fused feature and its corresponding 3D pose are separately encoded by LSAEs. A two-layer back-propagation neural network is trained by parameter fine-tuning and then used to map the encoded 2D features to encoded 3D poses. Our LSAE ensures a good preservation of the local topology of data points. Experimental results demonstrate the effectiveness of our proposed method.

  12. Person-Independent Head Pose Estimation Using Biased Manifold Embedding

    Directory of Open Access Journals (Sweden)

    Sethuraman Panchanathan

    2008-02-01

    Full Text Available Head pose estimation has been an integral problem in the study of face recognition systems and human-computer interfaces, as part of biometric applications. A fine estimate of the head pose angle is necessary and useful for several face analysis applications. To determine the head pose, face images with varying pose angles can be considered to be lying on a smooth low-dimensional manifold in high-dimensional image feature space. However, when there are face images of multiple individuals with varying pose angles, manifold learning techniques often do not give accurate results. In this work, we propose a framework for a supervised form of manifold learning called Biased Manifold Embedding to obtain improved performance in head pose angle estimation. This framework goes beyond pose estimation, and can be applied to all regression applications. This framework, although formulated for a regression scenario, unifies other supervised approaches to manifold learning that have been proposed so far. Detailed studies of the proposed method are carried out on the FacePix database, which contains 181 face images each of 30 individuals with pose angle variations at a granularity of 1∘. Since biometric applications in the real world may not contain this level of granularity in training data, an analysis of the methodology is performed on sparsely sampled data to validate its effectiveness. We obtained up to 2∘ average pose angle estimation error in the results from our experiments, which matched the best results obtained for head pose estimation using related approaches.

  13. Pose estimation of industrial objects towards robot operation

    Science.gov (United States)

    Niu, Jie; Zhou, Fuqiang; Tan, Haishu; Cao, Yu

    2017-10-01

    With the advantages of wide range, non-contact and high flexibility, the visual estimation technology of target pose has been widely applied in modern industry, robot guidance and other engineering practices. However, due to the influence of complicated industrial environment, outside interference factors, lack of object characteristics, restrictions of camera and other limitations, the visual estimation technology of target pose is still faced with many challenges. Focusing on the above problems, a pose estimation method of the industrial objects is developed based on 3D models of targets. By matching the extracted shape characteristics of objects with the priori 3D model database of targets, the method realizes the recognition of target. Thus a pose estimation of objects can be determined based on the monocular vision measuring model. The experimental results show that this method can be implemented to estimate the position of rigid objects based on poor images information, and provides guiding basis for the operation of the industrial robot.

  14. Gaussian particle filter based pose and motion estimation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Determination of relative three-dimensional (3D) position, orientation, and relative motion between two reference frames is an important problem in robotic guidance, manipulation, and assembly as well as in other fields such as photogrammetry.A solution to pose and motion estimation problem that uses two-dimensional (2D) intensity images from a single camera is desirable for real-time applications. The difficulty in performing this measurement is that the process of projecting 3D object features to 2D images is a nonlinear transformation. In this paper, the 3D transformation is modeled as a nonlinear stochastic system with the state estimation providing six degrees-of-freedom motion and position values, using line features in image plane as measuring inputs and dual quaternion to represent both rotation and translation in a unified notation. A filtering method called the Gaussian particle filter (GPF) based on the particle filtering concept is presented for 3D pose and motion estimation of a moving target from monocular image sequences. The method has been implemented with simulated data, and simulation results are provided along with comparisons to the extended Kalman filter (EKF) and the unscented Kalman filter (UKF) to show the relative advantages of the GPF. Simulation results showed that GPF is a superior alternative to EKF and UKF.

  15. Drogue pose estimation for unmanned aerial vehicle autonomous aerial refueling system based on infrared vision sensor

    Science.gov (United States)

    Chen, Shanjun; Duan, Haibin; Deng, Yimin; Li, Cong; Zhao, Guozhi; Xu, Yan

    2017-12-01

    Autonomous aerial refueling is a significant technology that can significantly extend the endurance of unmanned aerial vehicles. A reliable method that can accurately estimate the position and attitude of the probe relative to the drogue is the key to such a capability. A drogue pose estimation method based on infrared vision sensor is introduced with the general goal of yielding an accurate and reliable drogue state estimate. First, by employing direct least squares ellipse fitting and convex hull in OpenCV, a feature point matching and interference point elimination method is proposed. In addition, considering the conditions that some infrared LEDs are damaged or occluded, a missing point estimation method based on perspective transformation and affine transformation is designed. Finally, an accurate and robust pose estimation algorithm improved by the runner-root algorithm is proposed. The feasibility of the designed visual measurement system is demonstrated by flight test, and the results indicate that our proposed method enables precise and reliable pose estimation of the probe relative to the drogue, even in some poor conditions.

  16. Improving head and body pose estimation through semi-supervised manifold alignment

    KAUST Repository

    Heili, Alexandre

    2014-10-27

    In this paper, we explore the use of a semi-supervised manifold alignment method for domain adaptation in the context of human body and head pose estimation in videos. We build upon an existing state-of-the-art system that leverages on external labelled datasets for the body and head features, and on the unlabelled test data with weak velocity labels to do a coupled estimation of the body and head pose. While this previous approach showed promising results, the learning of the underlying manifold structure of the features in the train and target data and the need to align them were not explored despite the fact that the pose features between two datasets may vary according to the scene, e.g. due to different camera point of view or perspective. In this paper, we propose to use a semi-supervised manifold alignment method to bring the train and target samples closer within the resulting embedded space. To this end, we consider an adaptation set from the target data and rely on (weak) labels, given for example by the velocity direction whenever they are reliable. These labels, along with the training labels are used to bias the manifold distance within each manifold and to establish correspondences for alignment.

  17. Pose estimation for mobile robots working on turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Ma, X.D.; Chen, Q.; Liu, J.J.; Sun, Z.G.; Zhang, W.Z. [Tsinghua Univ., Beijing (China). Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Dept. of Mechanical Engineering

    2009-03-11

    This paper discussed a features point detection and matching task technique for mobile robots used in wind turbine blade applications. The vision-based scheme used visual information from the robot's surrounding environment to match successive image frames. An improved pose estimation algorithm based on a scale invariant feature transform (SIFT) was developed to consider the characteristics of local images of turbine blades, pose estimation problems, and conditions. The method included a pre-subsampling technique for reducing computation and bidirectional matching for improving precision. A random sample consensus (RANSAC) method was used to estimate the robot's pose. Pose estimation conditions included a wide pose range; the distance between neighbouring blades; and mechanical, electromagnetic, and optical disturbances. An experimental platform was used to demonstrate the validity of the proposed algorithm. 20 refs., 6 figs.

  18. Robust head pose estimation via supervised manifold learning.

    Science.gov (United States)

    Wang, Chao; Song, Xubo

    2014-05-01

    Head poses can be automatically estimated using manifold learning algorithms, with the assumption that with the pose being the only variable, the face images should lie in a smooth and low-dimensional manifold. However, this estimation approach is challenging due to other appearance variations related to identity, head location in image, background clutter, facial expression, and illumination. To address the problem, we propose to incorporate supervised information (pose angles of training samples) into the process of manifold learning. The process has three stages: neighborhood construction, graph weight computation and projection learning. For the first two stages, we redefine inter-point distance for neighborhood construction as well as graph weight by constraining them with the pose angle information. For Stage 3, we present a supervised neighborhood-based linear feature transformation algorithm to keep the data points with similar pose angles close together but the data points with dissimilar pose angles far apart. The experimental results show that our method has higher estimation accuracy than the other state-of-art algorithms and is robust to identity and illumination variations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. An improved silhouette for human pose estimation

    Science.gov (United States)

    Hawes, Anthony H.; Iftekharuddin, Khan M.

    2017-08-01

    We propose a novel method for analyzing images that exploits the natural lines of a human poses to find areas where self-occlusion could be present. Errors caused by self-occlusion cause several modern human pose estimation methods to mis-identify body parts, which reduces the performance of most action recognition algorithms. Our method is motivated by the observation that, in several cases, occlusion can be reasoned using only boundary lines of limbs. An intelligent edge detection algorithm based on the above principle could be used to augment the silhouette with information useful for pose estimation algorithms and push forward progress on occlusion handling for human action recognition. The algorithm described is applicable to computer vision scenarios involving 2D images and (appropriated flattened) 3D images.

  20. Perspective projection for variance pose face recognition from camera calibration

    Science.gov (United States)

    Fakhir, M. M.; Woo, W. L.; Chambers, J. A.; Dlay, S. S.

    2016-04-01

    Variance pose is an important research topic in face recognition. The alteration of distance parameters across variance pose face features is a challenging. We provide a solution for this problem using perspective projection for variance pose face recognition. Our method infers intrinsic camera parameters of the image which enable the projection of the image plane into 3D. After this, face box tracking and centre of eyes detection can be identified using our novel technique to verify the virtual face feature measurements. The coordinate system of the perspective projection for face tracking allows the holistic dimensions for the face to be fixed in different orientations. The training of frontal images and the rest of the poses on FERET database determine the distance from the centre of eyes to the corner of box face. The recognition system compares the gallery of images against different poses. The system initially utilises information on position of both eyes then focuses principally on closest eye in order to gather data with greater reliability. Differentiation between the distances and position of the right and left eyes is a unique feature of our work with our algorithm outperforming other state of the art algorithms thus enabling stable measurement in variance pose for each individual.

  1. A combined vision-inertial fusion approach for 6-DoF object pose estimation

    Science.gov (United States)

    Li, Juan; Bernardos, Ana M.; Tarrío, Paula; Casar, José R.

    2015-02-01

    The estimation of the 3D position and orientation of moving objects (`pose' estimation) is a critical process for many applications in robotics, computer vision or mobile services. Although major research efforts have been carried out to design accurate, fast and robust indoor pose estimation systems, it remains as an open challenge to provide a low-cost, easy to deploy and reliable solution. Addressing this issue, this paper describes a hybrid approach for 6 degrees of freedom (6-DoF) pose estimation that fuses acceleration data and stereo vision to overcome the respective weaknesses of single technology approaches. The system relies on COTS technologies (standard webcams, accelerometers) and printable colored markers. It uses a set of infrastructure cameras, located to have the object to be tracked visible most of the operation time; the target object has to include an embedded accelerometer and be tagged with a fiducial marker. This simple marker has been designed for easy detection and segmentation and it may be adapted to different service scenarios (in shape and colors). Experimental results show that the proposed system provides high accuracy, while satisfactorily dealing with the real-time constraints.

  2. Head pose estimation from a 2D face image using 3D face morphing with depth parameters.

    Science.gov (United States)

    Kong, Seong G; Mbouna, Ralph Oyini

    2015-06-01

    This paper presents estimation of head pose angles from a single 2D face image using a 3D face model morphed from a reference face model. A reference model refers to a 3D face of a person of the same ethnicity and gender as the query subject. The proposed scheme minimizes the disparity between the two sets of prominent facial features on the query face image and the corresponding points on the 3D face model to estimate the head pose angles. The 3D face model used is morphed from a reference model to be more specific to the query face in terms of the depth error at the feature points. The morphing process produces a 3D face model more specific to the query image when multiple 2D face images of the query subject are available for training. The proposed morphing process is computationally efficient since the depth of a 3D face model is adjusted by a scalar depth parameter at feature points. Optimal depth parameters are found by minimizing the disparity between the 2D features of the query face image and the corresponding features on the morphed 3D model projected onto 2D space. The proposed head pose estimation technique was evaluated on two benchmarking databases: 1) the USF Human-ID database for depth estimation and 2) the Pointing'04 database for head pose estimation. Experiment results demonstrate that head pose estimation errors in nodding and shaking angles are as low as 7.93° and 4.65° on average for a single 2D input face image.

  3. Human action recognition based on estimated weak poses

    Science.gov (United States)

    Gong, Wenjuan; Gonzàlez, Jordi; Roca, Francesc Xavier

    2012-12-01

    We present a novel method for human action recognition (HAR) based on estimated poses from image sequences. We use 3D human pose data as additional information and propose a compact human pose representation, called a weak pose, in a low-dimensional space while still keeping the most discriminative information for a given pose. With predicted poses from image features, we map the problem from image feature space to pose space, where a Bag of Poses (BOP) model is learned for the final goal of HAR. The BOP model is a modified version of the classical bag of words pipeline by building the vocabulary based on the most representative weak poses for a given action. Compared with the standard k-means clustering, our vocabulary selection criteria is proven to be more efficient and robust against the inherent challenges of action recognition. Moreover, since for action recognition the ordering of the poses is discriminative, the BOP model incorporates temporal information: in essence, groups of consecutive poses are considered together when computing the vocabulary and assignment. We tested our method on two well-known datasets: HumanEva and IXMAS, to demonstrate that weak poses aid to improve action recognition accuracies. The proposed method is scene-independent and is comparable with the state-of-art method.

  4. Point Cloud Based Relative Pose Estimation of a Satellite in Close Range

    Directory of Open Access Journals (Sweden)

    Lujiang Liu

    2016-06-01

    Full Text Available Determination of the relative pose of satellites is essential in space rendezvous operations and on-orbit servicing missions. The key problems are the adoption of suitable sensor on board of a chaser and efficient techniques for pose estimation. This paper aims to estimate the pose of a target satellite in close range on the basis of its known model by using point cloud data generated by a flash LIDAR sensor. A novel model based pose estimation method is proposed; it includes a fast and reliable pose initial acquisition method based on global optimal searching by processing the dense point cloud data directly, and a pose tracking method based on Iterative Closest Point algorithm. Also, a simulation system is presented in this paper in order to evaluate the performance of the sensor and generate simulated sensor point cloud data. It also provides truth pose of the test target so that the pose estimation error can be quantified. To investigate the effectiveness of the proposed approach and achievable pose accuracy, numerical simulation experiments are performed; results demonstrate algorithm capability of operating with point cloud directly and large pose variations. Also, a field testing experiment is conducted and results show that the proposed method is effective.

  5. Pose estimation for augmented reality applications using genetic algorithm.

    Science.gov (United States)

    Yu, Ying Kin; Wong, Kin Hong; Chang, Michael Ming Yuen

    2005-12-01

    This paper describes a genetic algorithm that tackles the pose-estimation problem in computer vision. Our genetic algorithm can find the rotation and translation of an object accurately when the three-dimensional structure of the object is given. In our implementation, each chromosome encodes both the pose and the indexes to the selected point features of the object. Instead of only searching for the pose as in the existing work, our algorithm, at the same time, searches for a set containing the most reliable feature points in the process. This mismatch filtering strategy successfully makes the algorithm more robust under the presence of point mismatches and outliers in the images. Our algorithm has been tested with both synthetic and real data with good results. The accuracy of the recovered pose is compared to the existing algorithms. Our approach outperformed the Lowe's method and the other two genetic algorithms under the presence of point mismatches and outliers. In addition, it has been used to estimate the pose of a real object. It is shown that the proposed method is applicable to augmented reality applications.

  6. An anti-disturbing real time pose estimation method and system

    Science.gov (United States)

    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

  7. Head Pose Estimation on Eyeglasses Using Line Detection and Classification Approach

    Science.gov (United States)

    Setthawong, Pisal; Vannija, Vajirasak

    This paper proposes a unique approach for head pose estimation of subjects with eyeglasses by using a combination of line detection and classification approaches. Head pose estimation is considered as an important non-verbal form of communication and could also be used in the area of Human-Computer Interface. A major improvement of the proposed approach is that it allows estimation of head poses at a high yaw/pitch angle when compared with existing geometric approaches, does not require expensive data preparation and training, and is generally fast when compared with other approaches.

  8. Pose Estimation and Adaptive Robot Behaviour for Human-Robot Interaction

    DEFF Research Database (Denmark)

    Svenstrup, Mikael; Hansen, Søren Tranberg; Andersen, Hans Jørgen

    2009-01-01

    Abstract—This paper introduces a new method to determine a person’s pose based on laser range measurements. Such estimates are typically a prerequisite for any human-aware robot navigation, which is the basis for effective and timeextended interaction between a mobile robot and a human. The robot......’s pose. The resulting pose estimates are used to identify humans who wish to be approached and interacted with. The interaction motion of the robot is based on adaptive potential functions centered around the person that respect the persons social spaces. The method is tested in experiments...

  9. Head Pose Estimation Using Multilinear Subspace Analysis for Robot Human Awareness

    Science.gov (United States)

    Ivanov, Tonislav; Matthies, Larry; Vasilescu, M. Alex O.

    2009-01-01

    Mobile robots, operating in unconstrained indoor and outdoor environments, would benefit in many ways from perception of the human awareness around them. Knowledge of people's head pose and gaze directions would enable the robot to deduce which people are aware of the its presence, and to predict future motions of the people for better path planning. To make such inferences, requires estimating head pose on facial images that are combination of multiple varying factors, such as identity, appearance, head pose, and illumination. By applying multilinear algebra, the algebra of higher-order tensors, we can separate these factors and estimate head pose regardless of subject's identity or image conditions. Furthermore, we can automatically handle uncertainty in the size of the face and its location. We demonstrate a pipeline of on-the-move detection of pedestrians with a robot stereo vision system, segmentation of the head, and head pose estimation in cluttered urban street scenes.

  10. A pose estimation method for unmanned ground vehicles in GPS denied environments

    Science.gov (United States)

    Tamjidi, Amirhossein; Ye, Cang

    2012-06-01

    This paper presents a pose estimation method based on the 1-Point RANSAC EKF (Extended Kalman Filter) framework. The method fuses the depth data from a LIDAR and the visual data from a monocular camera to estimate the pose of a Unmanned Ground Vehicle (UGV) in a GPS denied environment. Its estimation framework continuy updates the vehicle's 6D pose state and temporary estimates of the extracted visual features' 3D positions. In contrast to the conventional EKF-SLAM (Simultaneous Localization And Mapping) frameworks, the proposed method discards feature estimates from the extended state vector once they are no longer observed for several steps. As a result, the extended state vector always maintains a reasonable size that is suitable for online calculation. The fusion of laser and visual data is performed both in the feature initialization part of the EKF-SLAM process and in the motion prediction stage. A RANSAC pose calculation procedure is devised to produce pose estimate for the motion model. The proposed method has been successfully tested on the Ford campus's LIDAR-Vision dataset. The results are compared with the ground truth data of the dataset and the estimation error is ~1.9% of the path length.

  11. 6-DOF Pose Estimation of a Robotic Navigation Aid by Tracking Visual and Geometric Features.

    Science.gov (United States)

    Ye, Cang; Hong, Soonhac; Tamjidi, Amirhossein

    2015-10-01

    This paper presents a 6-DOF Pose Estimation (PE) method for a Robotic Navigation Aid (RNA) for the visually impaired. The RNA uses a single 3D camera for PE and object detection. The proposed method processes the camera's intensity and range data to estimates the camera's egomotion that is then used by an Extended Kalman Filter (EKF) as the motion model to track a set of visual features for PE. A RANSAC process is employed in the EKF to identify inliers from the visual feature correspondences between two image frames. Only the inliers are used to update the EKF's state. The EKF integrates the egomotion into the camera's pose in the world coordinate system. To retain the EKF's consistency, the distance between the camera and the floor plane (extracted from the range data) is used by the EKF as the observation of the camera's z coordinate. Experimental results demonstrate that the proposed method results in accurate pose estimates for positioning the RNA in indoor environments. Based on the PE method, a wayfinding system is developed for localization of the RNA in a home environment. The system uses the estimated pose and the floorplan to locate the RNA user in the home environment and announces the points of interest and navigational commands to the user through a speech interface. This work was motivated by the limitations of the existing navigation technology for the visually impaired. Most of the existing methods use a point/line measurement sensor for indoor object detection. Therefore, they lack capability in detecting 3D objects and positioning a blind traveler. Stereovision has been used in recent research. However, it cannot provide reliable depth data for object detection. Also, it tends to produce a lower localization accuracy because its depth measurement error quadratically increases with the true distance. This paper suggests a new approach for navigating a blind traveler. The method uses a single 3D time-of-flight camera for both 6-DOF PE and 3D object

  12. Relative Pose Estimation Algorithm with Gyroscope Sensor

    Directory of Open Access Journals (Sweden)

    Shanshan Wei

    2016-01-01

    Full Text Available This paper proposes a novel vision and inertial fusion algorithm S2fM (Simplified Structure from Motion for camera relative pose estimation. Different from current existing algorithms, our algorithm estimates rotation parameter and translation parameter separately. S2fM employs gyroscopes to estimate camera rotation parameter, which is later fused with the image data to estimate camera translation parameter. Our contributions are in two aspects. (1 Under the circumstance that no inertial sensor can estimate accurately enough translation parameter, we propose a translation estimation algorithm by fusing gyroscope sensor and image data. (2 Our S2fM algorithm is efficient and suitable for smart devices. Experimental results validate efficiency of the proposed S2fM algorithm.

  13. Teach it Yourself - Fast Modeling of Industrial Objects for 6D Pose Estimation

    DEFF Research Database (Denmark)

    Sølund, Thomas; Rajeeth Savarimuthu, Thiusius; Glent Buch, Anders

    2015-01-01

    In this paper, we present a vision system that allows a human to create new 3D models of novel industrial parts by placing the part in two different positions in the scene. The two shot modeling framework generates models with a precision that allows the model to be used for 6D pose estimation wi....... In addition, the models are applied in a pose estimation application, evaluated with 37 different scenes with 61 unique object poses. The pose estimation results show a mean translation error on 4.97 mm and a mean rotation error on 3.38 degrees....

  14. Perturbation-Based Regularization for Signal Estimation in Linear Discrete Ill-posed Problems

    KAUST Repository

    Suliman, Mohamed Abdalla Elhag; Ballal, Tarig; Al-Naffouri, Tareq Y.

    2016-01-01

    Estimating the values of unknown parameters from corrupted measured data faces a lot of challenges in ill-posed problems. In such problems, many fundamental estimation methods fail to provide a meaningful stabilized solution. In this work, we propose a new regularization approach and a new regularization parameter selection approach for linear least-squares discrete ill-posed problems. The proposed approach is based on enhancing the singular-value structure of the ill-posed model matrix to acquire a better solution. Unlike many other regularization algorithms that seek to minimize the estimated data error, the proposed approach is developed to minimize the mean-squared error of the estimator which is the objective in many typical estimation scenarios. The performance of the proposed approach is demonstrated by applying it to a large set of real-world discrete ill-posed problems. Simulation results demonstrate that the proposed approach outperforms a set of benchmark regularization methods in most cases. In addition, the approach also enjoys the lowest runtime and offers the highest level of robustness amongst all the tested benchmark regularization methods.

  15. Perturbation-Based Regularization for Signal Estimation in Linear Discrete Ill-posed Problems

    KAUST Repository

    Suliman, Mohamed Abdalla Elhag

    2016-11-29

    Estimating the values of unknown parameters from corrupted measured data faces a lot of challenges in ill-posed problems. In such problems, many fundamental estimation methods fail to provide a meaningful stabilized solution. In this work, we propose a new regularization approach and a new regularization parameter selection approach for linear least-squares discrete ill-posed problems. The proposed approach is based on enhancing the singular-value structure of the ill-posed model matrix to acquire a better solution. Unlike many other regularization algorithms that seek to minimize the estimated data error, the proposed approach is developed to minimize the mean-squared error of the estimator which is the objective in many typical estimation scenarios. The performance of the proposed approach is demonstrated by applying it to a large set of real-world discrete ill-posed problems. Simulation results demonstrate that the proposed approach outperforms a set of benchmark regularization methods in most cases. In addition, the approach also enjoys the lowest runtime and offers the highest level of robustness amongst all the tested benchmark regularization methods.

  16. A multi-camera system for real-time pose estimation

    Science.gov (United States)

    Savakis, Andreas; Erhard, Matthew; Schimmel, James; Hnatow, Justin

    2007-04-01

    This paper presents a multi-camera system that performs face detection and pose estimation in real-time and may be used for intelligent computing within a visual sensor network for surveillance or human-computer interaction. The system consists of a Scene View Camera (SVC), which operates at a fixed zoom level, and an Object View Camera (OVC), which continuously adjusts its zoom level to match objects of interest. The SVC is set to survey the whole filed of view. Once a region has been identified by the SVC as a potential object of interest, e.g. a face, the OVC zooms in to locate specific features. In this system, face candidate regions are selected based on skin color and face detection is accomplished using a Support Vector Machine classifier. The locations of the eyes and mouth are detected inside the face region using neural network feature detectors. Pose estimation is performed based on a geometrical model, where the head is modeled as a spherical object that rotates upon the vertical axis. The triangle formed by the mouth and eyes defines a vertical plane that intersects the head sphere. By projecting the eyes-mouth triangle onto a two dimensional viewing plane, equations were obtained that describe the change in its angles as the yaw pose angle increases. These equations are then combined and used for efficient pose estimation. The system achieves real-time performance for live video input. Testing results assessing system performance are presented for both still images and video.

  17. Improving head and body pose estimation through semi-supervised manifold alignment

    KAUST Repository

    Heili, Alexandre; Varadarajan, Jagannadan; Ghanem, Bernard; Ahuja, Narendra; Odobez, Jean-Marc

    2014-01-01

    structure of the features in the train and target data and the need to align them were not explored despite the fact that the pose features between two datasets may vary according to the scene, e.g. due to different camera point of view or perspective

  18. Probabilistic Mapping of Human Visual Attention from Head Pose Estimation

    Directory of Open Access Journals (Sweden)

    Andrea Veronese

    2017-10-01

    Full Text Available Effective interaction between a human and a robot requires the bidirectional perception and interpretation of actions and behavior. While actions can be identified as a directly observable activity, this might not be sufficient to deduce actions in a scene. For example, orienting our face toward a book might suggest the action toward “reading.” For a human observer, this deduction requires the direction of gaze, the object identified as a book and the intersection between gaze and book. With this in mind, we aim to estimate and map human visual attention as directed to a scene, and assess how this relates to the detection of objects and their related actions. In particular, we consider human head pose as measurement to infer the attention of a human engaged in a task and study which prior knowledge should be included in such a detection system. In a user study, we show the successful detection of attention to objects in a typical office task scenario (i.e., reading, working with a computer, studying an object. Our system requires a single external RGB camera for head pose measurements and a pre-recorded 3D point cloud of the environment.

  19. A deep learning approach for pose estimation from volumetric OCT data.

    Science.gov (United States)

    Gessert, Nils; Schlüter, Matthias; Schlaefer, Alexander

    2018-05-01

    Tracking the pose of instruments is a central problem in image-guided surgery. For microscopic scenarios, optical coherence tomography (OCT) is increasingly used as an imaging modality. OCT is suitable for accurate pose estimation due to its micrometer range resolution and volumetric field of view. However, OCT image processing is challenging due to speckle noise and reflection artifacts in addition to the images' 3D nature. We address pose estimation from OCT volume data with a new deep learning-based tracking framework. For this purpose, we design a new 3D convolutional neural network (CNN) architecture to directly predict the 6D pose of a small marker geometry from OCT volumes. We use a hexapod robot to automatically acquire labeled data points which we use to train 3D CNN architectures for multi-output regression. We use this setup to provide an in-depth analysis on deep learning-based pose estimation from volumes. Specifically, we demonstrate that exploiting volume information for pose estimation yields higher accuracy than relying on 2D representations with depth information. Supporting this observation, we provide quantitative and qualitative results that 3D CNNs effectively exploit the depth structure of marker objects. Regarding the deep learning aspect, we present efficient design principles for 3D CNNs, making use of insights from the 2D deep learning community. In particular, we present Inception3D as a new architecture which performs best for our application. We show that our deep learning approach reaches errors at our ground-truth label's resolution. We achieve a mean average error of 14.89 ± 9.3 µm and 0.096 ± 0.072° for position and orientation learning, respectively. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Monocular-Based 6-Degree of Freedom Pose Estimation Technology for Robotic Intelligent Grasping Systems

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2017-02-01

    Full Text Available Industrial robots are expected to undertake ever more advanced tasks in the modern manufacturing industry, such as intelligent grasping, in which robots should be capable of recognizing the position and orientation of a part before grasping it. In this paper, a monocular-based 6-degree of freedom (DOF pose estimation technology to enable robots to grasp large-size parts at informal poses is proposed. A camera was mounted on the robot end-flange and oriented to measure several featured points on the part before the robot moved to grasp it. In order to estimate the part pose, a nonlinear optimization model based on the camera object space collinearity error in different poses is established, and the initial iteration value is estimated with the differential transformation. Measuring poses of the camera are optimized based on uncertainty analysis. Also, the principle of the robotic intelligent grasping system was developed, with which the robot could adjust its pose to grasp the part. In experimental tests, the part poses estimated with the method described in this paper were compared with those produced by a laser tracker, and results show the RMS angle and position error are about 0.0228° and 0.4603 mm. Robotic intelligent grasping tests were also successfully performed in the experiments.

  1. Single leg balancing in ballet: effects of shoe conditions and poses.

    Science.gov (United States)

    Lobo da Costa, Paula H; Azevedo Nora, Fernanda G S; Vieira, Marcus Fraga; Bosch, Kerstin; Rosenbaum, Dieter

    2013-03-01

    The purpose of this study was to describe the effects of lower limb positioning and shoe conditions on stability levels of selected single leg ballet poses performed in demi-pointe position. Fourteen female non-professional ballet dancers (mean age of 18.4±2.8 years and mean body mass index of 21.5±2.8kg/m(2)) who had practiced ballet for at least seven years, without any musculoskeletal impairment volunteered to participate in this study. A capacitive pressure platform allowed for the assessment of center of pressure variables related to the execution of three single leg ballet poses in demi pointé position: attitude devant, attitude derriére, and attitude a la second. Peak pressures, contact areas, COP oscillation areas, anterior-posterior and medio-lateral COP oscillations and velocities were compared between two shoe conditions (barefoot versus slippers) and among the different poses. Barefoot performances produced more stable poses with significantly higher plantar contact areas, smaller COP oscillation areas and smaller anterior-posterior COP oscillations. COP oscillation areas, anterior-posterior COP oscillations and medio-lateral COP velocities indicated that attitude a la second is the least challenging and attitude derriére the most challenging pose. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Combining Front Vehicle Detection with 3D Pose Estimation for a Better Driver Assistance

    Directory of Open Access Journals (Sweden)

    Yu Peng

    2012-09-01

    Full Text Available Driver assistant systems enhance traffic safety and efficiency. The accurate 3D pose of a front vehicle can help a driver to make the right decision on the road. We propose a novel real-time system to estimate the 3D pose of the front vehicle. This system consists of two parallel threads: vehicle rear tracking and mapping. The vehicle rear is first identified in the video captured by an onboard camera, after license plate localization and foreground extraction. The 3D pose estimation technique is then employed with respect to the extracted vehicle rear. Most current 3D pose estimation techniques need prior models or a stereo initialization with user cooperation. It is extremely difficult to obtain prior models due to the varying appearance of vehicles' rears. Moreover, it is unsafe to ask for drivers' cooperation when a vehicle is running. In our system, two initial keyframes for stereo algorithms are automatically extracted by vehicle rear detection and tracking. Map points are defined as a collection of point features extracted from the vehicle's rear with their 3D information. These map points are inferences that relate the 2D features detected in following vehicles' rears with the 3D world. The relative 3D pose of the onboard camera to the front vehicle rear is then estimated through matching the map points with point features detected on the front vehicle rear. We demonstrate the capabilities of our system by testing on real-time and synthesized videos. In order to make the experimental analysis visible, we demonstrated an estimated 3D pose through augmented reality, which needs accurate and real-time 3D pose estimation.

  3. The investigation and implementation of real-time face pose and direction estimation on mobile computing devices

    Science.gov (United States)

    Fu, Deqian; Gao, Lisheng; Jhang, Seong Tae

    2012-04-01

    The mobile computing device has many limitations, such as relative small user interface and slow computing speed. Usually, augmented reality requires face pose estimation can be used as a HCI and entertainment tool. As far as the realtime implementation of head pose estimation on relatively resource limited mobile platforms is concerned, it is required to face different constraints while leaving enough face pose estimation accuracy. The proposed face pose estimation method met this objective. Experimental results running on a testing Android mobile device delivered satisfactory performing results in the real-time and accurately.

  4. A new benchmark for pose estimation with ground truth from virtual reality

    DEFF Research Database (Denmark)

    Schlette, Christian; Buch, Anders Glent; Aksoy, Eren Erdal

    2014-01-01

    The development of programming paradigms for industrial assembly currently gets fresh impetus from approaches in human demonstration and programming-by-demonstration. Major low- and mid-level prerequisites for machine vision and learning in these intelligent robotic applications are pose estimation......, stereo reconstruction and action recognition. As a basis for the machine vision and learning involved, pose estimation is used for deriving object positions and orientations and thus target frames for robot execution. Our contribution introduces and applies a novel benchmark for typical multi...

  5. Hierarchical graphical-based human pose estimation via local multi-resolution convolutional neural network

    Science.gov (United States)

    Zhu, Aichun; Wang, Tian; Snoussi, Hichem

    2018-03-01

    This paper addresses the problems of the graphical-based human pose estimation in still images, including the diversity of appearances and confounding background clutter. We present a new architecture for estimating human pose using a Convolutional Neural Network (CNN). Firstly, a Relative Mixture Deformable Model (RMDM) is defined by each pair of connected parts to compute the relative spatial information in the graphical model. Secondly, a Local Multi-Resolution Convolutional Neural Network (LMR-CNN) is proposed to train and learn the multi-scale representation of each body parts by combining different levels of part context. Thirdly, a LMR-CNN based hierarchical model is defined to explore the context information of limb parts. Finally, the experimental results demonstrate the effectiveness of the proposed deep learning approach for human pose estimation.

  6. Hierarchical graphical-based human pose estimation via local multi-resolution convolutional neural network

    Directory of Open Access Journals (Sweden)

    Aichun Zhu

    2018-03-01

    Full Text Available This paper addresses the problems of the graphical-based human pose estimation in still images, including the diversity of appearances and confounding background clutter. We present a new architecture for estimating human pose using a Convolutional Neural Network (CNN. Firstly, a Relative Mixture Deformable Model (RMDM is defined by each pair of connected parts to compute the relative spatial information in the graphical model. Secondly, a Local Multi-Resolution Convolutional Neural Network (LMR-CNN is proposed to train and learn the multi-scale representation of each body parts by combining different levels of part context. Thirdly, a LMR-CNN based hierarchical model is defined to explore the context information of limb parts. Finally, the experimental results demonstrate the effectiveness of the proposed deep learning approach for human pose estimation.

  7. Full Body Pose Estimation During Occlusion using Multiple Cameras

    DEFF Research Database (Denmark)

    Fihl, Preben; Cosar, Serhan

    people is a very challenging problem for methods based on pictorials structure as for any other monocular pose estimation method. In this report we present work on a multi-view approach based on pictorial structures that integrate low level information from multiple calibrated cameras to improve the 2D...

  8. Temporal subtraction of chest radiographs compensating pose differences

    Science.gov (United States)

    von Berg, Jens; Dworzak, Jalda; Klinder, Tobias; Manke, Dirk; Kreth, Adrian; Lamecker, Hans; Zachow, Stefan; Lorenz, Cristian

    2011-03-01

    Temporal subtraction techniques using 2D image registration improve the detectability of interval changes from chest radiographs. Although such methods are well known for some time they are not widely used in radiologic practice. The reason is the occurrence of strong pose differences between two acquisitions with a time interval of months to years in between. Such strong perspective differences occur in a reasonable number of cases. They cannot be compensated by available image registration methods and thus mask interval changes to be undetectable. In this paper a method is proposed to estimate a 3D pose difference by the adaptation of a 3D rib cage model to both projections. The difference between both is then compensated for, thus producing a subtraction image with virtually no change in pose. The method generally assumes that no 3D image data is available from the patient. The accuracy of pose estimation is validated with chest phantom images acquired under controlled geometric conditions. A subtle interval change simulated by a piece of plastic foam attached to the phantom becomes visible in subtraction images generated with this technique even at strong angular pose differences like an anterior-posterior inclination of 13 degrees.

  9. Head Pose Estimation on Top of Haar-Like Face Detection: A Study Using the Kinect Sensor

    Directory of Open Access Journals (Sweden)

    Anwar Saeed

    2015-08-01

    Full Text Available Head pose estimation is a crucial initial task for human face analysis, which is employed in several computer vision systems, such as: facial expression recognition, head gesture recognition, yawn detection, etc. In this work, we propose a frame-based approach to estimate the head pose on top of the Viola and Jones (VJ Haar-like face detector. Several appearance and depth-based feature types are employed for the pose estimation, where comparisons between them in terms of accuracy and speed are presented. It is clearly shown through this work that using the depth data, we improve the accuracy of the head pose estimation. Additionally, we can spot positive detections, faces in profile views detected by the frontal model, that are wrongly cropped due to background disturbances. We introduce a new depth-based feature descriptor that provides competitive estimation results with a lower computation time. Evaluation on a benchmark Kinect database shows that the histogram of oriented gradients and the developed depth-based features are more distinctive for the head pose estimation, where they compare favorably to the current state-of-the-art approaches. Using a concatenation of the aforementioned feature types, we achieved a head pose estimation with average errors not exceeding 5:1; 4:6; 4:2 for pitch, yaw and roll angles, respectively.

  10. Robotic-surgical instrument wrist pose estimation.

    Science.gov (United States)

    Fabel, Stephan; Baek, Kyungim; Berkelman, Peter

    2010-01-01

    The Compact Lightweight Surgery Robot from the University of Hawaii includes two teleoperated instruments and one endoscope manipulator which act in accord to perform assisted interventional medicine. The relative positions and orientations of the robotic instruments and endoscope must be known to the teleoperation system so that the directions of the instrument motions can be controlled to correspond closely to the directions of the motions of the master manipulators, as seen by the the endoscope and displayed to the surgeon. If the manipulator bases are mounted in known locations and all manipulator joint variables are known, then the necessary coordinate transformations between the master and slave manipulators can be easily computed. The versatility and ease of use of the system can be increased, however, by allowing the endoscope or instrument manipulator bases to be moved to arbitrary positions and orientations without reinitializing each manipulator or remeasuring their relative positions. The aim of this work is to find the pose of the instrument end effectors using the video image from the endoscope camera. The P3P pose estimation algorithm is used with a Levenberg-Marquardt optimization to ensure convergence. The correct transformations between the master and slave coordinate frames can then be calculated and updated when the bases of the endoscope or instrument manipulators are moved to new, unknown, positions at any time before or during surgical procedures.

  11. The relative pose estimation of aircraft based on contour model

    Science.gov (United States)

    Fu, Tai; Sun, Xiangyi

    2017-02-01

    This paper proposes a relative pose estimation approach based on object contour model. The first step is to obtain a two-dimensional (2D) projection of three-dimensional (3D)-model-based target, which will be divided into 40 forms by clustering and LDA analysis. Then we proceed by extracting the target contour in each image and computing their Pseudo-Zernike Moments (PZM), thus a model library is constructed in an offline mode. Next, we spot a projection contour that resembles the target silhouette most in the present image from the model library with reference of PZM; then similarity transformation parameters are generated as the shape context is applied to match the silhouette sampling location, from which the identification parameters of target can be further derived. Identification parameters are converted to relative pose parameters, in the premise that these values are the initial result calculated via iterative refinement algorithm, as the relative pose parameter is in the neighborhood of actual ones. At last, Distance Image Iterative Least Squares (DI-ILS) is employed to acquire the ultimate relative pose parameters.

  12. Robust Pose Estimation using the SwissRanger SR-3000 Camera

    DEFF Research Database (Denmark)

    Gudmundsson, Sigurjon Arni; Larsen, Rasmus; Ersbøll, Bjarne Kjær

    2007-01-01

    In this paper a robust method is presented to classify and estimate an objects pose from a real time range image and a low dimensional model. The model is made from a range image training set which is reduced dimensionally by a nonlinear manifold learning method named Local Linear Embedding (LLE)......). New range images are then projected to this model giving the low dimensional coordinates of the object pose in an efficient manner. The range images are acquired by a state of the art SwissRanger SR-3000 camera making the projection process work in real-time....

  13. Relative Pose Estimation and Accuracy Verification of Spherical Panoramic Image

    Directory of Open Access Journals (Sweden)

    XIE Donghai

    2017-11-01

    Full Text Available This paper improves the method of the traditional 5-point relative pose estimation algorithm, and proposes a relative pose estimation algorithm which is suitable for spherical panoramic images. The algorithm firstly computes the essential matrix, then decomposes the essential matrix to obtain the rotation matrix and the translation vector using SVD, and finally the reconstructed three-dimensional points are used to eliminate the error solution. The innovation of the algorithm lies the derivation of panorama epipolar formula and the use of the spherical distance from the point to the epipolar plane as the error term for the spherical panorama co-planarity function. The simulation experiment shows that when the random noise of the image feature points is within the range of pixel, the error of the three Euler angles is about 0.1°, and the error between the relative translational displacement and the simulated value is about 1.5°. The result of the experiment using the data obtained by the vehicle panorama camera and the POS shows that:the error of the roll angle and pitch angle can be within 0.2°, the error of the heading angle can be within 0.4°, and the error between the relative translational displacement and the POS can be within 2°. The result of our relative pose estimation algorithm is used to generate the spherical panoramic epipolar images, then we extract the key points between the spherical panoramic images and calculate the errors in the column direction. The result shows that the errors is less than 1 pixel.

  14. The Pose Estimation of Mobile Robot Based on Improved Point Cloud Registration

    Directory of Open Access Journals (Sweden)

    Yanzi Miao

    2016-03-01

    Full Text Available Due to GPS restrictions, an inertial sensor is usually used to estimate the location of indoor mobile robots. However, it is difficult to achieve high-accuracy localization and control by inertial sensors alone. In this paper, a new method is proposed to estimate an indoor mobile robot pose with six degrees of freedom based on an improved 3D-Normal Distributions Transform algorithm (3D-NDT. First, point cloud data are captured by a Kinect sensor and segmented according to the distance to the robot. After the segmentation, the input point cloud data are processed by the Approximate Voxel Grid Filter algorithm in different sized voxel grids. Second, the initial registration and precise registration are performed respectively according to the distance to the sensor. The most distant point cloud data use the 3D-Normal Distributions Transform algorithm (3D-NDT with large-sized voxel grids for initial registration, based on the transformation matrix from the odometry method. The closest point cloud data use the 3D-NDT algorithm with small-sized voxel grids for precise registration. After the registrations above, a final transformation matrix is obtained and coordinated. Based on this transformation matrix, the pose estimation problem of the indoor mobile robot is solved. Test results show that this method can obtain accurate robot pose estimation and has better robustness.

  15. Estimation de pose omnidirectionnelle dans un contexte de réalité augmentée

    OpenAIRE

    Poirier, Stéphane

    2012-01-01

    Estimer la pose de la caméra est un défi fondamental en réalité augmentée et permet la superposition d’un modèle à la réalité. Estimer précisément la pose est souvent critique en ingénierie d’infrastructures. Les images omnidirectionnelles ont un champ de vision supérieur aux images planaires communément utilisées en RA. Cette propriété peut bénéficier à l’estimation de la pose. Or, aucun travail ne présente de résultats montrant clairement un gain de précision. Notre objectif est de quantifi...

  16. An Improved Method of Pose Estimation for Lighthouse Base Station Extension.

    Science.gov (United States)

    Yang, Yi; Weng, Dongdong; Li, Dong; Xun, Hang

    2017-10-22

    In 2015, HTC and Valve launched a virtual reality headset empowered with Lighthouse, the cutting-edge space positioning technology. Although Lighthouse is superior in terms of accuracy, latency and refresh rate, its algorithms do not support base station expansion, and is flawed concerning occlusion in moving targets, that is, it is unable to calculate their poses with a small set of sensors, resulting in the loss of optical tracking data. In view of these problems, this paper proposes an improved pose estimation algorithm for cases where occlusion is involved. Our algorithm calculates the pose of a given object with a unified dataset comprising of inputs from sensors recognized by all base stations, as long as three or more sensors detect a signal in total, no matter from which base station. To verify our algorithm, HTC official base stations and autonomous developed receivers are used for prototyping. The experiment result shows that our pose calculation algorithm can achieve precise positioning when a few sensors detect the signal.

  17. Camera pose estimation for augmented reality in a small indoor dynamic scene

    Science.gov (United States)

    Frikha, Rawia; Ejbali, Ridha; Zaied, Mourad

    2017-09-01

    Camera pose estimation remains a challenging task for augmented reality (AR) applications. Simultaneous localization and mapping (SLAM)-based methods are able to estimate the six degrees of freedom camera motion while constructing a map of an unknown environment. However, these methods do not provide any reference for where to insert virtual objects since they do not have any information about scene structure and may fail in cases of occlusion of three-dimensional (3-D) map points or dynamic objects. This paper presents a real-time monocular piece wise planar SLAM method using the planar scene assumption. Using planar structures in the mapping process allows rendering virtual objects in a meaningful way on the one hand and improving the precision of the camera pose and the quality of 3-D reconstruction of the environment by adding constraints on 3-D points and poses in the optimization process on the other hand. We proposed to benefit from the 3-D planes rigidity motion in the tracking process to enhance the system robustness in the case of dynamic scenes. Experimental results show that using a constrained planar scene improves our system accuracy and robustness compared with the classical SLAM systems.

  18. Towards real-time body pose estimation for presenters in meeting environments

    NARCIS (Netherlands)

    Poppe, Ronald Walter; Heylen, Dirk K.J.; Nijholt, Antinus; Poel, Mannes

    2005-01-01

    This paper describes a computer vision-based approach to body pose estimation. The algorithm can be executed in real-time and processes low resolution, monocular image sequences. A silhouette is extracted and matched against a projection of a 16 DOF human body model. In addition, skin color is used

  19. Automated pose estimation of objects using multiple ID devices for handling and maintenance task in nuclear fusion reactor

    International Nuclear Information System (INIS)

    Umetani, Tomohiro; Morioka, Jun-ichi; Tamura, Yuichi; Inoue, Kenji; Arai, Tatsuo; Mae, Yasusi

    2011-01-01

    This paper describes a method for the automated estimation of three-dimensional pose (position and orientation) of objects by autonomous robots, using multiple identification (ID) devices. Our goal is to estimate the object pose for assembly or maintenance tasks in a real nuclear fusion reactor system, with autonomous robots cooperating in a virtual assembly system. The method estimates the three-dimensional pose for autonomous robots. This paper discusses a method of motion generation for ID acquisition using the sensory data acquired by the measurement system attached to the robots and from the environment. Experimental results show the feasibility of the proposed method. (author)

  20. Body-part templates for recovery of 2D human poses under occlusion

    NARCIS (Netherlands)

    Poppe, Ronald Walter; Poel, Mannes; Perales, F.J.; Fisher, R.B.

    2008-01-01

    Detection of humans and estimation of their 2D poses from a single image are challenging tasks. This is especially true when part of the observation is occluded. However, given a limited class of movements, poses can be recovered given the visible body-parts. To this end, we propose a novel template

  1. NUI framework based on real-time head pose estimation and hand gesture recognition

    Directory of Open Access Journals (Sweden)

    Kim Hyunduk

    2016-01-01

    Full Text Available The natural user interface (NUI is used for the natural motion interface without using device or tool such as mice, keyboards, pens and markers. In this paper, we develop natural user interface framework based on two recognition module. First module is real-time head pose estimation module using random forests and second module is hand gesture recognition module, named Hand gesture Key Emulation Toolkit (HandGKET. Using the head pose estimation module, we can know where the user is looking and what the user’s focus of attention is. Moreover, using the hand gesture recognition module, we can also control the computer using the user’s hand gesture without mouse and keyboard. In proposed framework, the user’s head direction and hand gesture are mapped into mouse and keyboard event, respectively.

  2. Using Online Modelled Spatial Constraints for Pose Estimation in an Industrial Setting

    DEFF Research Database (Denmark)

    Meyer, Kenneth Korsgaard; Wolniakowski, Adam; Hagelskjær, Frederik

    2017-01-01

    We introduce a vision system that is able to on-line learn spatial constraints to improve pose estimation in terms of correct recognition as well as computational speed. By making use of a simulated industrial robot system performing various pick and place tasks, we show the effect of model...

  3. 3D head pose estimation and tracking using particle filtering and ICP algorithm

    KAUST Repository

    Ben Ghorbel, Mahdi; Baklouti, Malek; Couvet, Serge

    2010-01-01

    This paper addresses the issue of 3D head pose estimation and tracking. Existing approaches generally need huge database, training procedure, manual initialization or use face feature extraction manually extracted. We propose a framework for estimating the 3D head pose in its fine level and tracking it continuously across multiple Degrees of Freedom (DOF) based on ICP and particle filtering. We propose to approach the problem, using 3D computational techniques, by aligning a face model to the 3D dense estimation computed by a stereo vision method, and propose a particle filter algorithm to refine and track the posteriori estimate of the position of the face. This work comes with two contributions: the first concerns the alignment part where we propose an extended ICP algorithm using an anisotropic scale transformation. The second contribution concerns the tracking part. We propose the use of the particle filtering algorithm and propose to constrain the search space using ICP algorithm in the propagation step. The results show that the system is able to fit and track the head properly, and keeps accurate the results on new individuals without a manual adaptation or training. © Springer-Verlag Berlin Heidelberg 2010.

  4. Voxel-based registration of simulated and real patient CBCT data for accurate dental implant pose estimation

    Science.gov (United States)

    Moreira, António H. J.; Queirós, Sandro; Morais, Pedro; Rodrigues, Nuno F.; Correia, André Ricardo; Fernandes, Valter; Pinho, A. C. M.; Fonseca, Jaime C.; Vilaça, João. L.

    2015-03-01

    The success of dental implant-supported prosthesis is directly linked to the accuracy obtained during implant's pose estimation (position and orientation). Although traditional impression techniques and recent digital acquisition methods are acceptably accurate, a simultaneously fast, accurate and operator-independent methodology is still lacking. Hereto, an image-based framework is proposed to estimate the patient-specific implant's pose using cone-beam computed tomography (CBCT) and prior knowledge of implanted model. The pose estimation is accomplished in a threestep approach: (1) a region-of-interest is extracted from the CBCT data using 2 operator-defined points at the implant's main axis; (2) a simulated CBCT volume of the known implanted model is generated through Feldkamp-Davis-Kress reconstruction and coarsely aligned to the defined axis; and (3) a voxel-based rigid registration is performed to optimally align both patient and simulated CBCT data, extracting the implant's pose from the optimal transformation. Three experiments were performed to evaluate the framework: (1) an in silico study using 48 implants distributed through 12 tridimensional synthetic mandibular models; (2) an in vitro study using an artificial mandible with 2 dental implants acquired with an i-CAT system; and (3) two clinical case studies. The results shown positional errors of 67+/-34μm and 108μm, and angular misfits of 0.15+/-0.08° and 1.4°, for experiment 1 and 2, respectively. Moreover, in experiment 3, visual assessment of clinical data results shown a coherent alignment of the reference implant. Overall, a novel image-based framework for implants' pose estimation from CBCT data was proposed, showing accurate results in agreement with dental prosthesis modelling requirements.

  5. Utilizing Semantic Interpretation of Junctions for 3D-2D Pose Estimation

    DEFF Research Database (Denmark)

    Pilz, Florian; Yan, Shi; Grest, Daniel

    2007-01-01

    In this paper we investigate the quality of 3D-2D pose estimates using hand labeled line and point correspondences. We select point correspondences from junctions in the image, allowing to construct a meaningful interpretation about how the junction is formed, as proposed in e.g. [1], [2], [3]. W...

  6. Robustness of Input features from Noisy Silhouettes in Human Pose Estimation

    DEFF Research Database (Denmark)

    Gong, Wenjuan; Fihl, Preben; Gonzàlez, Jordi

    2014-01-01

    . In this paper, we explore this problem. First, We compare performances of several image features widely used for human pose estimation and explore their performances against each other and select one with best performance. Second, iterative closest point algorithm is introduced for a new quantitative...... of silhouette samples of different noise levels and compare with the selected feature on a public dataset: Human Eva dataset....

  7. Estimation of G-renewal process parameters as an ill-posed inverse problem

    International Nuclear Information System (INIS)

    Krivtsov, V.; Yevkin, O.

    2013-01-01

    Statistical estimation of G-renewal process parameters is an important estimation problem, which has been considered by many authors. We view this problem from the standpoint of a mathematically ill-posed, inverse problem (the solution is not unique and/or is sensitive to statistical error) and propose a regularization approach specifically suited to the G-renewal process. Regardless of the estimation method, the respective objective function usually involves parameters of the underlying life-time distribution and simultaneously the restoration parameter. In this paper, we propose to regularize the problem by decoupling the estimation of the aforementioned parameters. Using a simulation study, we show that the resulting estimation/extrapolation accuracy of the proposed method is considerably higher than that of the existing methods

  8. Regularization parameter selection methods for ill-posed Poisson maximum likelihood estimation

    International Nuclear Information System (INIS)

    Bardsley, Johnathan M; Goldes, John

    2009-01-01

    In image processing applications, image intensity is often measured via the counting of incident photons emitted by the object of interest. In such cases, image data noise is accurately modeled by a Poisson distribution. This motivates the use of Poisson maximum likelihood estimation for image reconstruction. However, when the underlying model equation is ill-posed, regularization is needed. Regularized Poisson likelihood estimation has been studied extensively by the authors, though a problem of high importance remains: the choice of the regularization parameter. We will present three statistically motivated methods for choosing the regularization parameter, and numerical examples will be presented to illustrate their effectiveness

  9. 3D pose estimation and motion analysis of the articulated human hand-forearm limb in an industrial production environment

    Science.gov (United States)

    Hahn, Markus; Barrois, Björn; Krüger, Lars; Wöhler, Christian; Sagerer, Gerhard; Kummert, Franz

    2010-09-01

    This study introduces an approach to model-based 3D pose estimation and instantaneous motion analysis of the human hand-forearm limb in the application context of safe human-robot interaction. 3D pose estimation is performed using two approaches: The Multiocular Contracting Curve Density (MOCCD) algorithm is a top-down technique based on pixel statistics around a contour model projected into the images from several cameras. The Iterative Closest Point (ICP) algorithm is a bottom-up approach which uses a motion-attributed 3D point cloud to estimate the object pose. Due to their orthogonal properties, a fusion of these algorithms is shown to be favorable. The fusion is performed by a weighted combination of the extracted pose parameters in an iterative manner. The analysis of object motion is based on the pose estimation result and the motion-attributed 3D points belonging to the hand-forearm limb using an extended constraint-line approach which does not rely on any temporal filtering. A further refinement is obtained using the Shape Flow algorithm, a temporal extension of the MOCCD approach, which estimates the temporal pose derivative based on the current and the two preceding images, corresponding to temporal filtering with a short response time of two or at most three frames. Combining the results of the two motion estimation stages provides information about the instantaneous motion properties of the object. Experimental investigations are performed on real-world image sequences displaying several test persons performing different working actions typically occurring in an industrial production scenario. In all example scenes, the background is cluttered, and the test persons wear various kinds of clothes. For evaluation, independently obtained ground truth data are used. [Figure not available: see fulltext.

  10. Surgical fiducial segmentation and tracking for pose estimation based on ultrasound B-mode images.

    Science.gov (United States)

    Lei Chen; Kuo, Nathanael; Aalamifar, Fereshteh; Narrow, David; Coon, Devin; Prince, Jerry; Boctor, Emad M

    2016-08-01

    Doppler ultrasound is a non-invasive diagnostic tool for the quantitative measurement of blood flow. However, given that it provides velocity data that is dependent on the location and angle of measurement, repeat measurements to detect problems over time may require an expert to return to the same location. We therefore developed an image-guidance system based on ultrasound B-mode images that enables an inexperienced user to position the ultrasound probe at the same site repeatedly in order to acquire a comparable time series of Doppler readings. The system utilizes a bioresorbable fiducial and complementing software composed of the fiducial detection, key points tracking, probe pose estimation, and graphical user interface (GUI) modules. The fiducial is an echogenic marker that is implanted at the surgical site and can be detected and tracked during ultrasound B-mode screening. The key points on the marker can next be used to determine the pose of the ultrasound probe with respect to the marker. The 3D representation of the probe with its position and orientation are then displayed in the GUI for the user guidance. The fiducial detection has been tested on the data sets collected from three animal studies. The pose estimation algorithm was validated by five data sets collected by a UR5 robot. We tested the system on a plastisol phantom and showed that it can detect and track the fiducial marker while displaying the probe pose in real-time.

  11. Marker detection evaluation by phantom and cadaver experiments for C-arm pose estimation pattern

    Science.gov (United States)

    Steger, Teena; Hoßbach, Martin; Wesarg, Stefan

    2013-03-01

    C-arm fluoroscopy is used for guidance during several clinical exams, e.g. in bronchoscopy to locate the bronchoscope inside the airways. Unfortunately, these images provide only 2D information. However, if the C-arm pose is known, it can be used to overlay the intrainterventional fluoroscopy images with 3D visualizations of airways, acquired from preinterventional CT images. Thus, the physician's view is enhanced and localization of the instrument at the correct position inside the bronchial tree is facilitated. We present a novel method for C-arm pose estimation introducing a marker-based pattern, which is placed on the patient table. The steel markers form a pattern, allowing to deduce the C-arm pose by use of the projective invariant cross-ratio. Simulations show that the C-arm pose estimation is reliable and accurate for translations inside an imaging area of 30 cm x 50 cm and rotations up to 30°. Mean error values are 0.33 mm in 3D space and 0.48 px in the 2D imaging plane. First tests on C-arm images resulted in similarly compelling accuracy values and high reliability in an imaging area of 30 cm x 42.5 cm. Even in the presence of interfering structures, tested both with anatomy phantoms and a turkey cadaver, high success rates over 90% and fully satisfying execution times below 4 sec for 1024 px × 1024 px images could be achieved.

  12. Methods of RVD object pose estimation and experiments

    Science.gov (United States)

    Shang, Yang; He, Yan; Wang, Weihua; Yu, Qifeng

    2007-11-01

    Methods of measuring a RVD (rendezvous and docking) cooperative object's pose from monocular and binocular images respectively are presented. The methods solve the initial values first and optimize the object pose parameters by bundle adjustment. In the disturbance-rejecting binocular method, chosen measurement system parameters of one camera's exterior parameters are modified simultaneously. The methods need three or more cooperative target points to measure the object's pose accurately. Experimental data show that the methods converge quickly and stably, provide accurate results and do not need accurate initial values. Even when the chosen measurement system parameters are subjected to some amount of disturbance, the binocular method manages to provide fairly accurate results.

  13. Camera-pose estimation via projective Newton optimization on the manifold.

    Science.gov (United States)

    Sarkis, Michel; Diepold, Klaus

    2012-04-01

    Determining the pose of a moving camera is an important task in computer vision. In this paper, we derive a projective Newton algorithm on the manifold to refine the pose estimate of a camera. The main idea is to benefit from the fact that the 3-D rigid motion is described by the special Euclidean group, which is a Riemannian manifold. The latter is equipped with a tangent space defined by the corresponding Lie algebra. This enables us to compute the optimization direction, i.e., the gradient and the Hessian, at each iteration of the projective Newton scheme on the tangent space of the manifold. Then, the motion is updated by projecting back the variables on the manifold itself. We also derive another version of the algorithm that employs homeomorphic parameterization to the special Euclidean group. We test the algorithm on several simulated and real image data sets. Compared with the standard Newton minimization scheme, we are now able to obtain the full numerical formula of the Hessian with a 60% decrease in computational complexity. Compared with Levenberg-Marquardt, the results obtained are more accurate while having a rather similar complexity.

  14. Segmentation, classification, and pose estimation of military vehicles in low resolution laser radar images

    Science.gov (United States)

    Neulist, Joerg; Armbruster, Walter

    2005-05-01

    Model-based object recognition in range imagery typically involves matching the image data to the expected model data for each feasible model and pose hypothesis. Since the matching procedure is computationally expensive, the key to efficient object recognition is the reduction of the set of feasible hypotheses. This is particularly important for military vehicles, which may consist of several large moving parts such as the hull, turret, and gun of a tank, and hence require an eight or higher dimensional pose space to be searched. The presented paper outlines techniques for reducing the set of feasible hypotheses based on an estimation of target dimensions and orientation. Furthermore, the presence of a turret and a main gun and their orientations are determined. The vehicle parts dimensions as well as their error estimates restrict the number of model hypotheses whereas the position and orientation estimates and their error bounds reduce the number of pose hypotheses needing to be verified. The techniques are applied to several hundred laser radar images of eight different military vehicles with various part classifications and orientations. On-target resolution in azimuth, elevation and range is about 30 cm. The range images contain up to 20% dropouts due to atmospheric absorption. Additionally some target retro-reflectors produce outliers due to signal crosstalk. The presented algorithms are extremely robust with respect to these and other error sources. The hypothesis space for hull orientation is reduced to about 5 degrees as is the error for turret rotation and gun elevation, provided the main gun is visible.

  15. Exemplar-based human action pose correction.

    Science.gov (United States)

    Shen, Wei; Deng, Ke; Bai, Xiang; Leyvand, Tommer; Guo, Baining; Tu, Zhuowen

    2014-07-01

    The launch of Xbox Kinect has built a very successful computer vision product and made a big impact on the gaming industry. This sheds lights onto a wide variety of potential applications related to action recognition. The accurate estimation of human poses from the depth image is universally a critical step. However, existing pose estimation systems exhibit failures when facing severe occlusion. In this paper, we propose an exemplar-based method to learn to correct the initially estimated poses. We learn an inhomogeneous systematic bias by leveraging the exemplar information within a specific human action domain. Furthermore, as an extension, we learn a conditional model by incorporation of pose tags to further increase the accuracy of pose correction. In the experiments, significant improvements on both joint-based skeleton correction and tag prediction are observed over the contemporary approaches, including what is delivered by the current Kinect system. Our experiments for the facial landmark correction also illustrate that our algorithm can improve the accuracy of other detection/estimation systems.

  16. Simulation-Based Optimization of Camera Placement in the Context of Industrial Pose Estimation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Bo; Iversen, Thorbjørn Mosekjær; Lindvig, Anders Prier

    2018-01-01

    In this paper, we optimize the placement of a camera in simulation in order to achieve a high success rate for a pose estimation problem. This is achieved by simulating 2D images from a stereo camera in a virtual scene. The stereo images are then used to generate 3D point clouds based on two diff...

  17. Neuro-fuzzy model for estimating race and gender from geometric distances of human face across pose

    Science.gov (United States)

    Nanaa, K.; Rahman, M. N. A.; Rizon, M.; Mohamad, F. S.; Mamat, M.

    2018-03-01

    Classifying human face based on race and gender is a vital process in face recognition. It contributes to an index database and eases 3D synthesis of the human face. Identifying race and gender based on intrinsic factor is problematic, which is more fitting to utilizing nonlinear model for estimating process. In this paper, we aim to estimate race and gender in varied head pose. For this purpose, we collect dataset from PICS and CAS-PEAL databases, detect the landmarks and rotate them to the frontal pose. After geometric distances are calculated, all of distance values will be normalized. Implementation is carried out by using Neural Network Model and Fuzzy Logic Model. These models are combined by using Adaptive Neuro-Fuzzy Model. The experimental results showed that the optimization of address fuzzy membership. Model gives a better assessment rate and found that estimating race contributing to a more accurate gender assessment.

  18. Feature and Pose Constrained Visual Aided Inertial Navigation for Computationally Constrained Aerial Vehicles

    Science.gov (United States)

    Williams, Brian; Hudson, Nicolas; Tweddle, Brent; Brockers, Roland; Matthies, Larry

    2011-01-01

    A Feature and Pose Constrained Extended Kalman Filter (FPC-EKF) is developed for highly dynamic computationally constrained micro aerial vehicles. Vehicle localization is achieved using only a low performance inertial measurement unit and a single camera. The FPC-EKF framework augments the vehicle's state with both previous vehicle poses and critical environmental features, including vertical edges. This filter framework efficiently incorporates measurements from hundreds of opportunistic visual features to constrain the motion estimate, while allowing navigating and sustained tracking with respect to a few persistent features. In addition, vertical features in the environment are opportunistically used to provide global attitude references. Accurate pose estimation is demonstrated on a sequence including fast traversing, where visual features enter and exit the field-of-view quickly, as well as hover and ingress maneuvers where drift free navigation is achieved with respect to the environment.

  19. An investigation into multi-dimensional prediction models to estimate the pose error of a quadcopter in a CSP plant setting

    Science.gov (United States)

    Lock, Jacobus C.; Smit, Willie J.; Treurnicht, Johann

    2016-05-01

    The Solar Thermal Energy Research Group (STERG) is investigating ways to make heliostats cheaper to reduce the total cost of a concentrating solar power (CSP) plant. One avenue of research is to use unmanned aerial vehicles (UAVs) to automate and assist with the heliostat calibration process. To do this, the pose estimation error of each UAV must be determined and integrated into a calibration procedure. A computer vision (CV) system is used to measure the pose of a quadcopter UAV. However, this CV system contains considerable measurement errors. Since this is a high-dimensional problem, a sophisticated prediction model must be used to estimate the measurement error of the CV system for any given pose measurement vector. This paper attempts to train and validate such a model with the aim of using it to determine the pose error of a quadcopter in a CSP plant setting.

  20. Challenges Posed by Novel Psychoactive Substances – Middle East Perspective

    Directory of Open Access Journals (Sweden)

    Maciej J. Bogusz

    2017-04-01

    Full Text Available New psychoactive substances (NPS are defined as substances of abuse, either in a pure form or a preparation, that are not controlled by the 1961 Single Convention on Narcotic Drugs or the 1971 Convention on Psychotropic Substances, but which may pose a public health threat. In this context, the term “new” does not necessarily refer to new inventions but to substances that have recently become available or popular in a given society or country. This definition indicates that the problem of NPS is not new; however, the availability of any information via new communication technologies in the 21st century has enabled the spread of unwanted and socially harmful information, like information on the commercial availability of various NPS, offered in rising amounts and brands.

  1. Hardware in the Loop Performance Assessment of LIDAR-Based Spacecraft Pose Determination.

    Science.gov (United States)

    Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele

    2017-09-24

    In this paper an original, easy to reproduce, semi-analytic calibration approach is developed for hardware-in-the-loop performance assessment of pose determination algorithms processing point cloud data, collected by imaging a non-cooperative target with LIDARs. The laboratory setup includes a scanning LIDAR, a monocular camera, a scaled-replica of a satellite-like target, and a set of calibration tools. The point clouds are processed by uncooperative model-based algorithms to estimate the target relative position and attitude with respect to the LIDAR. Target images, acquired by a monocular camera operated simultaneously with the LIDAR, are processed applying standard solutions to the Perspective- n -Points problem to get high-accuracy pose estimates which can be used as a benchmark to evaluate the accuracy attained by the LIDAR-based techniques. To this aim, a precise knowledge of the extrinsic relative calibration between the camera and the LIDAR is essential, and it is obtained by implementing an original calibration approach which does not need ad-hoc homologous targets (e.g., retro-reflectors) easily recognizable by the two sensors. The pose determination techniques investigated by this work are of interest to space applications involving close-proximity maneuvers between non-cooperative platforms, e.g., on-orbit servicing and active debris removal.

  2. An Inertial and Optical Sensor Fusion Approach for Six Degree-of-Freedom Pose Estimation

    Science.gov (United States)

    He, Changyu; Kazanzides, Peter; Sen, Hasan Tutkun; Kim, Sungmin; Liu, Yue

    2015-01-01

    Optical tracking provides relatively high accuracy over a large workspace but requires line-of-sight between the camera and the markers, which may be difficult to maintain in actual applications. In contrast, inertial sensing does not require line-of-sight but is subject to drift, which may cause large cumulative errors, especially during the measurement of position. To handle cases where some or all of the markers are occluded, this paper proposes an inertial and optical sensor fusion approach in which the bias of the inertial sensors is estimated when the optical tracker provides full six degree-of-freedom (6-DOF) pose information. As long as the position of at least one marker can be tracked by the optical system, the 3-DOF position can be combined with the orientation estimated from the inertial measurements to recover the full 6-DOF pose information. When all the markers are occluded, the position tracking relies on the inertial sensors that are bias-corrected by the optical tracking system. Experiments are performed with an augmented reality head-mounted display (ARHMD) that integrates an optical tracking system (OTS) and inertial measurement unit (IMU). Experimental results show that under partial occlusion conditions, the root mean square errors (RMSE) of orientation and position are 0.04° and 0.134 mm, and under total occlusion conditions for 1 s, the orientation and position RMSE are 0.022° and 0.22 mm, respectively. Thus, the proposed sensor fusion approach can provide reliable 6-DOF pose under long-term partial occlusion and short-term total occlusion conditions. PMID:26184191

  3. Extended 3D Line Segments from RGB-D Data for Pose Estimation

    DEFF Research Database (Denmark)

    Buch, Anders Glent; Jessen, Jeppe Barsøe; Kraft, Dirk

    2013-01-01

    We propose a method for the extraction of complete and rich symbolic line segments in 3D based on RGB-D data. Edges are detected by combining cues from the RGB image and the aligned depth map. 3D line segments are then reconstructed by back-projecting 2D line segments and intersecting this with l...... this with local surface patches computed from the 3D point cloud. Different edge types are classified using the new enriched representation and the potential of this representation for the task of pose estimation is demonstrated....

  4. A Comparison of Iterative 2D-3D Pose Estimation Methods for Real-Time Applications

    DEFF Research Database (Denmark)

    Grest, Daniel; Krüger, Volker; Petersen, Thomas

    2009-01-01

    This work compares iterative 2D-3D Pose Estimation methods for use in real-time applications. The compared methods are available for public as C++ code. One method is part of the openCV library, namely POSIT. Because POSIT is not applicable for planar 3Dpoint congurations, we include the planar P...

  5. Human Pose Estimation and Activity Recognition from Multi-View Videos

    DEFF Research Database (Denmark)

    Holte, Michael Boelstoft; Tran, Cuong; Trivedi, Mohan

    2012-01-01

    approaches which have been proposed to comply with these requirements. We report a comparison of the most promising methods for multi-view human action recognition using two publicly available datasets: the INRIA Xmas Motion Acquisition Sequences (IXMAS) Multi-View Human Action Dataset, and the i3DPost Multi......–computer interaction (HCI), assisted living, gesture-based interactive games, intelligent driver assistance systems, movies, 3D TV and animation, physical therapy, autonomous mental development, smart environments, sport motion analysis, video surveillance, and video annotation. Next, we review and categorize recent......-View Human Action and Interaction Dataset. To compare the proposed methods, we give a qualitative assessment of methods which cannot be compared quantitatively, and analyze some prominent 3D pose estimation techniques for application, where not only the performed action needs to be identified but a more...

  6. Comparison of different methods for gender estimation from face image of various poses

    Science.gov (United States)

    Ishii, Yohei; Hongo, Hitoshi; Niwa, Yoshinori; Yamamoto, Kazuhiko

    2003-04-01

    Recently, gender estimation from face images has been studied for frontal facial images. However, it is difficult to obtain such facial images constantly in the case of application systems for security, surveillance and marketing research. In order to build such systems, a method is required to estimate gender from the image of various facial poses. In this paper, three different classifiers are compared in appearance-based gender estimation, which use four directional features (FDF). The classifiers are linear discriminant analysis (LDA), Support Vector Machines (SVMs) and Sparse Network of Winnows (SNoW). Face images used for experiments were obtained from 35 viewpoints. The direction of viewpoints varied +/-45 degrees horizontally, +/-30 degrees vertically at 15 degree intervals respectively. Although LDA showed the best performance for frontal facial images, SVM with Gaussian kernel was found the best performance (86.0%) for the facial images of 35 viewpoints. It is considered that SVM with Gaussian kernel is robust to changes in viewpoint when estimating gender from these results. Furthermore, the estimation rate was quite close to the average estimation rate at 35 viewpoints respectively. It is supposed that the methods are reasonable to estimate gender within the range of experimented viewpoints by learning face images from multiple directions by one class.

  7. 6DoF object pose measurement by a monocular manifold-based pattern recognition technique

    International Nuclear Information System (INIS)

    Kouskouridas, Rigas; Charalampous, Konstantinos; Gasteratos, Antonios

    2012-01-01

    In this paper, a novel solution to the compound problem of object recognition and 3D pose estimation is presented. An accurate measurement of the geometrical configuration of a recognized target, relative to a known coordinate system, is of fundamental importance and constitutes a prerequisite for several applications such as robot grasping or obstacle avoidance. The proposed method lays its foundations on the following assumptions: (a) the same object captured under varying viewpoints and perspectives represents data that could be projected onto a well-established and highly distinguishable subspace; (b) totally different objects observed under the same viewpoints and perspectives share identical 3D pose that can be sufficiently modeled to produce a generalized model. Toward this end, we propose an advanced architecture that allows both recognizing patterns and providing efficient solution for 6DoF pose estimation. We employ a manifold modeling architecture that is grounded on a part-based representation of an object, which in turn, is accomplished via an unsupervised clustering of the extracted visual cues. The main contributions of the proposed framework are: (a) the proposed part-based architecture requires minimum supervision, compared to other contemporary solutions, whilst extracting new features encapsulating both appearance and geometrical attributes of the objects; (b) contrary to related projects that extract high-dimensional data, thus, increasing the complexity of the system, the proposed manifold modeling approach makes use of low dimensionality input vectors; (c) the formulation of a novel input–output space mapping that outperforms the existing dimensionality reduction schemes. Experimental results justify our theoretical claims and demonstrate the superiority of our method comparing to other related contemporary projects. (paper)

  8. Head Pose Estimation from Passive Stereo Images

    DEFF Research Database (Denmark)

    Breitenstein, Michael D.; Jensen, Jeppe; Høilund, Carsten

    2009-01-01

    function. Our algorithm incorporates 2D and 3D cues to make the system robust to low-quality range images acquired by passive stereo systems. It handles large pose variations (of ±90 ° yaw and ±45 ° pitch rotation) and facial variations due to expressions or accessories. For a maximally allowed error of 30...

  9. Soft tissue navigation for laparoscopic prostatectomy: evaluation of camera pose estimation for enhanced visualization

    Science.gov (United States)

    Baumhauer, M.; Simpfendörfer, T.; Schwarz, R.; Seitel, M.; Müller-Stich, B. P.; Gutt, C. N.; Rassweiler, J.; Meinzer, H.-P.; Wolf, I.

    2007-03-01

    We introduce a novel navigation system to support minimally invasive prostate surgery. The system utilizes transrectal ultrasonography (TRUS) and needle-shaped navigation aids to visualize hidden structures via Augmented Reality. During the intervention, the navigation aids are segmented once from a 3D TRUS dataset and subsequently tracked by the endoscope camera. Camera Pose Estimation methods directly determine position and orientation of the camera in relation to the navigation aids. Accordingly, our system does not require any external tracking device for registration of endoscope camera and ultrasonography probe. In addition to a preoperative planning step in which the navigation targets are defined, the procedure consists of two main steps which are carried out during the intervention: First, the preoperatively prepared planning data is registered with an intraoperatively acquired 3D TRUS dataset and the segmented navigation aids. Second, the navigation aids are continuously tracked by the endoscope camera. The camera's pose can thereby be derived and relevant medical structures can be superimposed on the video image. This paper focuses on the latter step. We have implemented several promising real-time algorithms and incorporated them into the Open Source Toolkit MITK (www.mitk.org). Furthermore, we have evaluated them for minimally invasive surgery (MIS) navigation scenarios. For this purpose, a virtual evaluation environment has been developed, which allows for the simulation of navigation targets and navigation aids, including their measurement errors. Besides evaluating the accuracy of the computed pose, we have analyzed the impact of an inaccurate pose and the resulting displacement of navigation targets in Augmented Reality.

  10. Face pose tracking using the four-point algorithm

    Science.gov (United States)

    Fung, Ho Yin; Wong, Kin Hong; Yu, Ying Kin; Tsui, Kwan Pang; Kam, Ho Chuen

    2017-06-01

    In this paper, we have developed an algorithm to track the pose of a human face robustly and efficiently. Face pose estimation is very useful in many applications such as building virtual reality systems and creating an alternative input method for the disabled. Firstly, we have modified a face detection toolbox called DLib for the detection of a face in front of a camera. The detected face features are passed to a pose estimation method, known as the four-point algorithm, for pose computation. The theory applied and the technical problems encountered during system development are discussed in the paper. It is demonstrated that the system is able to track the pose of a face in real time using a consumer grade laptop computer.

  11. Single snapshot DOA estimation

    Science.gov (United States)

    Häcker, P.; Yang, B.

    2010-10-01

    In array signal processing, direction of arrival (DOA) estimation has been studied for decades. Many algorithms have been proposed and their performance has been studied thoroughly. Yet, most of these works are focused on the asymptotic case of a large number of snapshots. In automotive radar applications like driver assistance systems, however, only a small number of snapshots of the radar sensor array or, in the worst case, a single snapshot is available for DOA estimation. In this paper, we investigate and compare different DOA estimators with respect to their single snapshot performance. The main focus is on the estimation accuracy and the angular resolution in multi-target scenarios including difficult situations like correlated targets and large target power differences. We will show that some algorithms lose their ability to resolve targets or do not work properly at all. Other sophisticated algorithms do not show a superior performance as expected. It turns out that the deterministic maximum likelihood estimator is a good choice under these hard conditions.

  12. Stereovision-based pose and inertia estimation of unknown and uncooperative space objects

    Science.gov (United States)

    Pesce, Vincenzo; Lavagna, Michèle; Bevilacqua, Riccardo

    2017-01-01

    Autonomous close proximity operations are an arduous and attractive problem in space mission design. In particular, the estimation of pose, motion and inertia properties of an uncooperative object is a challenging task because of the lack of available a priori information. This paper develops a novel method to estimate the relative position, velocity, angular velocity, attitude and the ratios of the components of the inertia matrix of an uncooperative space object using only stereo-vision measurements. The classical Extended Kalman Filter (EKF) and an Iterated Extended Kalman Filter (IEKF) are used and compared for the estimation procedure. In addition, in order to compute the inertia properties, the ratios of the inertia components are added to the state and a pseudo-measurement equation is considered in the observation model. The relative simplicity of the proposed algorithm could be suitable for an online implementation for real applications. The developed algorithm is validated by numerical simulations in MATLAB using different initial conditions and uncertainty levels. The goal of the simulations is to verify the accuracy and robustness of the proposed estimation algorithm. The obtained results show satisfactory convergence of estimation errors for all the considered quantities. The obtained results, in several simulations, shows some improvements with respect to similar works, which deal with the same problem, present in literature. In addition, a video processing procedure is presented to reconstruct the geometrical properties of a body using cameras. This inertia reconstruction algorithm has been experimentally validated at the ADAMUS (ADvanced Autonomous MUltiple Spacecraft) Lab at the University of Florida. In the future, this different method could be integrated to the inertia ratios estimator to have a complete tool for mass properties recognition.

  13. Vision-Based Pose Estimation for Robot-Mediated Hand Telerehabilitation

    Directory of Open Access Journals (Sweden)

    Giuseppe Airò Farulla

    2016-02-01

    Full Text Available Vision-based Pose Estimation (VPE represents a non-invasive solution to allow a smooth and natural interaction between a human user and a robotic system, without requiring complex calibration procedures. Moreover, VPE interfaces are gaining momentum as they are highly intuitive, such that they can be used from untrained personnel (e.g., a generic caregiver even in delicate tasks as rehabilitation exercises. In this paper, we present a novel master–slave setup for hand telerehabilitation with an intuitive and simple interface for remote control of a wearable hand exoskeleton, named HX. While performing rehabilitative exercises, the master unit evaluates the 3D position of a human operator’s hand joints in real-time using only a RGB-D camera, and commands remotely the slave exoskeleton. Within the slave unit, the exoskeleton replicates hand movements and an external grip sensor records interaction forces, that are fed back to the operator-therapist, allowing a direct real-time assessment of the rehabilitative task. Experimental data collected with an operator and six volunteers are provided to show the feasibility of the proposed system and its performances. The results demonstrate that, leveraging on our system, the operator was able to directly control volunteers’ hands movements.

  14. Multi-task pose-invariant face recognition.

    Science.gov (United States)

    Ding, Changxing; Xu, Chang; Tao, Dacheng

    2015-03-01

    Face images captured in unconstrained environments usually contain significant pose variation, which dramatically degrades the performance of algorithms designed to recognize frontal faces. This paper proposes a novel face identification framework capable of handling the full range of pose variations within ±90° of yaw. The proposed framework first transforms the original pose-invariant face recognition problem into a partial frontal face recognition problem. A robust patch-based face representation scheme is then developed to represent the synthesized partial frontal faces. For each patch, a transformation dictionary is learnt under the proposed multi-task learning scheme. The transformation dictionary transforms the features of different poses into a discriminative subspace. Finally, face matching is performed at patch level rather than at the holistic level. Extensive and systematic experimentation on FERET, CMU-PIE, and Multi-PIE databases shows that the proposed method consistently outperforms single-task-based baselines as well as state-of-the-art methods for the pose problem. We further extend the proposed algorithm for the unconstrained face verification problem and achieve top-level performance on the challenging LFW data set.

  15. Driver head pose tracking with thermal camera

    Science.gov (United States)

    Bole, S.; Fournier, C.; Lavergne, C.; Druart, G.; Lépine, T.

    2016-09-01

    Head pose can be seen as a coarse estimation of gaze direction. In automotive industry, knowledge about gaze direction could optimize Human-Machine Interface (HMI) and Advanced Driver Assistance Systems (ADAS). Pose estimation systems are often based on camera when applications have to be contactless. In this paper, we explore uncooled thermal imagery (8-14μm) for its intrinsic night vision capabilities and for its invariance versus lighting variations. Two methods are implemented and compared, both are aided by a 3D model of the head. The 3D model, mapped with thermal texture, allows to synthesize a base of 2D projected models, differently oriented and labeled in yaw and pitch. The first method is based on keypoints. Keypoints of models are matched with those of the query image. These sets of matchings, aided with the 3D shape of the model, allow to estimate 3D pose. The second method is a global appearance approach. Among all 2D models of the base, algorithm searches the one which is the closest to the query image thanks to a weighted least squares difference.

  16. A robust statistical estimation (RoSE) algorithm jointly recovers the 3D location and intensity of single molecules accurately and precisely

    Science.gov (United States)

    Mazidi, Hesam; Nehorai, Arye; Lew, Matthew D.

    2018-02-01

    In single-molecule (SM) super-resolution microscopy, the complexity of a biological structure, high molecular density, and a low signal-to-background ratio (SBR) may lead to imaging artifacts without a robust localization algorithm. Moreover, engineered point spread functions (PSFs) for 3D imaging pose difficulties due to their intricate features. We develop a Robust Statistical Estimation algorithm, called RoSE, that enables joint estimation of the 3D location and photon counts of SMs accurately and precisely using various PSFs under conditions of high molecular density and low SBR.

  17. Trajectory Planning with Pose Feedback for a Dual-Arm Space Robot

    Directory of Open Access Journals (Sweden)

    Yicheng Liu

    2016-01-01

    Full Text Available In order to obtain high precision path tracking for a dual-arm space robot, a trajectory planning method with pose feedback is proposed to be introduced into the design process in this paper. Firstly, pose error kinematic models are derived from the related kinematics and desired pose command for the end-effector and the base, respectively. On this basis, trajectory planning with pose feedback is proposed from a control perspective. Theoretical analyses show that the proposed trajectory planning algorithm can guarantee that pose error converges to zero exponentially for both the end-effector and the base when the robot is out of singular configuration. Compared with the existing algorithms, the proposed algorithm can lead to higher precision path tracking for the end-effector. Furthermore, the algorithm renders the system good anti-interference property for the base. Simulation results demonstrate the effectiveness of the proposed trajectory planning algorithm.

  18. Perspectives on Modelling BIM-enabled Estimating Practices

    Directory of Open Access Journals (Sweden)

    Willy Sher

    2014-12-01

    Full Text Available BIM-enabled estimating processes do not replace or provide a substitute for the traditional approaches used in the architecture, engineering and construction industries. This paper explores the impact of BIM on these traditional processes.  It identifies differences between the approaches used with BIM and other conventional methods, and between the various construction professionals that prepare estimates. We interviewed 17 construction professionals from client organizations, contracting organizations, consulting practices and specialist-project firms. Our analyses highlight several logical relationships between estimating processes and BIM attributes. Estimators need to respond to the challenges BIM poses to traditional estimating practices. BIM-enabled estimating circumvents long-established conventions and traditional approaches, and focuses on data management.  Consideration needs to be given to the model data required for estimating, to the means by which these data may be harnessed when exported, to the means by which the integrity of model data are protected, to the creation and management of tools that work effectively and efficiently in multi-disciplinary settings, and to approaches that narrow the gap between virtual reality and actual reality.  Areas for future research are also identified in the paper.

  19. POSING THE HISTORICAL JESUS QUESTION AND THE GOAL OF ...

    African Journals Online (AJOL)

    mycl

    ... study recommended that. African scholars be allowed to develop and pose the Historical Jesus ... he is seen as the starting point for modern critical study of Jesus. (Burer). ... African anthropology and culture and the data of revelation, and how this theology ... Man” from two perspectives: that of a biblical culture in the first.

  20. Baseline Face Detection, Head Pose Estimation, and Coarse Direction Detection for Facial Data in the SHRP2 Naturalistic Driving Study

    Energy Technology Data Exchange (ETDEWEB)

    Paone, Jeffrey R [ORNL; Bolme, David S [ORNL; Ferrell, Regina Kay [ORNL; Aykac, Deniz [ORNL; Karnowski, Thomas Paul [ORNL

    2015-01-01

    Keeping a driver focused on the road is one of the most critical steps in insuring the safe operation of a vehicle. The Strategic Highway Research Program 2 (SHRP2) has over 3,100 recorded videos of volunteer drivers during a period of 2 years. This extensive naturalistic driving study (NDS) contains over one million hours of video and associated data that could aid safety researchers in understanding where the driver s attention is focused. Manual analysis of this data is infeasible, therefore efforts are underway to develop automated feature extraction algorithms to process and characterize the data. The real-world nature, volume, and acquisition conditions are unmatched in the transportation community, but there are also challenges because the data has relatively low resolution, high compression rates, and differing illumination conditions. A smaller dataset, the head pose validation study, is available which used the same recording equipment as SHRP2 but is more easily accessible with less privacy constraints. In this work we report initial head pose accuracy using commercial and open source face pose estimation algorithms on the head pose validation data set.

  1. Hand Pose Estimation by Fusion of Inertial and Magnetic Sensing Aided by a Permanent Magnet.

    Science.gov (United States)

    Kortier, Henk G; Antonsson, Jacob; Schepers, H Martin; Gustafsson, Fredrik; Veltink, Peter H

    2015-09-01

    Tracking human body motions using inertial sensors has become a well-accepted method in ambulatory applications since the subject is not confined to a lab-bounded volume. However, a major drawback is the inability to estimate relative body positions over time because inertial sensor information only allows position tracking through strapdown integration, but does not provide any information about relative positions. In addition, strapdown integration inherently results in drift of the estimated position over time. We propose a novel method in which a permanent magnet combined with 3-D magnetometers and 3-D inertial sensors are used to estimate the global trunk orientation and relative pose of the hand with respect to the trunk. An Extended Kalman Filter is presented to fuse estimates obtained from inertial sensors with magnetic updates such that the position and orientation between the human hand and trunk as well as the global trunk orientation can be estimated robustly. This has been demonstrated in multiple experiments in which various hand tasks were performed. The most complex task in which simultaneous movements of both trunk and hand were performed resulted in an average rms position difference with an optical reference system of 19.7±2.2 mm whereas the relative trunk-hand and global trunk orientation error was 2.3±0.9 and 8.6±8.7 deg respectively.

  2. Recovering the 3d Pose and Shape of Vehicles from Stereo Images

    Science.gov (United States)

    Coenen, M.; Rottensteiner, F.; Heipke, C.

    2018-05-01

    The precise reconstruction and pose estimation of vehicles plays an important role, e.g. for autonomous driving. We tackle this problem on the basis of street level stereo images obtained from a moving vehicle. Starting from initial vehicle detections, we use a deformable vehicle shape prior learned from CAD vehicle data to fully reconstruct the vehicles in 3D and to recover their 3D pose and shape. To fit a deformable vehicle model to each detection by inferring the optimal parameters for pose and shape, we define an energy function leveraging reconstructed 3D data, image information, the vehicle model and derived scene knowledge. To minimise the energy function, we apply a robust model fitting procedure based on iterative Monte Carlo model particle sampling. We evaluate our approach using the object detection and orientation estimation benchmark of the KITTI dataset (Geiger et al., 2012). Our approach can deal with very coarse pose initialisations and we achieve encouraging results with up to 82 % correct pose estimations. Moreover, we are able to deliver very precise orientation estimation results with an average absolute error smaller than 4°.

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

    Science.gov (United States)

    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).

  4. Pose estimation and tracking of non-cooperative rocket bodies using Time-of-Flight cameras

    Science.gov (United States)

    Gómez Martínez, Harvey; Giorgi, Gabriele; Eissfeller, Bernd

    2017-10-01

    This paper presents a methodology for estimating the position and orientation of a rocket body in orbit - the target - undergoing a roto-translational motion, with respect to a chaser spacecraft, whose task is to match the target dynamics for a safe rendezvous. During the rendezvous maneuver the chaser employs a Time-of-Flight camera that acquires a point cloud of 3D coordinates mapping the sensed target surface. Once the system identifies the target, it initializes the chaser-to-target relative position and orientation. After initialization, a tracking procedure enables the system to sense the evolution of the target's pose between frames. The proposed algorithm is evaluated using simulated point clouds, generated with a CAD model of the Cosmos-3M upper stage and the PMD CamCube 3.0 camera specifications.

  5. Web-based Visualisation of Head Pose and Facial Expressions Changes:

    DEFF Research Database (Denmark)

    Kalliatakis, Grigorios; Vidakis, Nikolaos; Triantafyllidis, Georgios

    2016-01-01

    Despite significant recent advances in the field of head pose estimation and facial expression recognition, raising the cognitive level when analysing human activity presents serious challenges to current concepts. Motivated by the need of generating comprehensible visual representations from...... and accurately estimate head pose changes in unconstrained environment. In order to complete the secondary process of recognising four universal dominant facial expressions (happiness, anger, sadness and surprise), emotion recognition via facial expressions (ERFE) was adopted. After that, a lightweight data...

  6. Single-Molecule Electronics: Chemical and Analytical Perspectives.

    Science.gov (United States)

    Nichols, Richard J; Higgins, Simon J

    2015-01-01

    It is now possible to measure the electrical properties of single molecules using a variety of techniques including scanning probe microcopies and mechanically controlled break junctions. Such measurements can be made across a wide range of environments including ambient conditions, organic liquids, ionic liquids, aqueous solutions, electrolytes, and ultra high vacuum. This has given new insights into charge transport across molecule electrical junctions, and these experimental methods have been complemented with increasingly sophisticated theory. This article reviews progress in single-molecule electronics from a chemical perspective and discusses topics such as the molecule-surface coupling in electrical junctions, chemical control, and supramolecular interactions in junctions and gating charge transport. The article concludes with an outlook regarding chemical analysis based on single-molecule conductance.

  7. Discriminating Projections for Estimating Face Age in Wild Images

    Energy Technology Data Exchange (ETDEWEB)

    Tokola, Ryan A [ORNL; Bolme, David S [ORNL; Ricanek, Karl [ORNL; Barstow, Del R [ORNL; Boehnen, Chris Bensing [ORNL

    2014-01-01

    We introduce a novel approach to estimating the age of a human from a single uncontrolled image. Current face age estimation algorithms work well in highly controlled images, and some are robust to changes in illumination, but it is usually assumed that images are close to frontal. This bias is clearly seen in the datasets that are commonly used to evaluate age estimation, which either entirely or mostly consist of frontal images. Using pose-specific projections, our algorithm maps image features into a pose-insensitive latent space that is discriminative with respect to age. Age estimation is then performed using a multi-class SVM. We show that our approach outperforms other published results on the Images of Groups dataset, which is the only age-related dataset with a non-trivial number of off-axis face images, and that we are competitive with recent age estimation algorithms on the mostly-frontal FG-NET dataset. We also experimentally demonstrate that our feature projections introduce insensitivity to pose.

  8. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications.

    Science.gov (United States)

    Musleh, Basam; Martín, David; Armingol, José María; de la Escalera, Arturo

    2016-09-14

    Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels) and the vehicle environment (meters) depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments.

  9. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications

    Science.gov (United States)

    Musleh, Basam; Martín, David; Armingol, José María; de la Escalera, Arturo

    2016-01-01

    Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels) and the vehicle environment (meters) depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments. PMID:27649178

  10. Landscape mapping MAV using single image perspective cues

    CSIR Research Space (South Africa)

    Tekane, YC

    2015-01-01

    Full Text Available in order to do mapping, our method does require a 3D model. Instead, our method first classifies the type of site the MAV is in, and the uses vision algorithms based on perspective cues to estimate the landscape location and the do mapping. We tested our...

  11. Attribute And-Or Grammar for Joint Parsing of Human Pose, Parts and Attributes.

    Science.gov (United States)

    Park, Seyoung; Nie, Xiaohan; Zhu, Song-Chun

    2017-07-25

    This paper presents an attribute and-or grammar (A-AOG) model for jointly inferring human body pose and human attributes in a parse graph with attributes augmented to nodes in the hierarchical representation. In contrast to other popular methods in the current literature that train separate classifiers for poses and individual attributes, our method explicitly represents the decomposition and articulation of body parts, and account for the correlations between poses and attributes. The A-AOG model is an amalgamation of three traditional grammar formulations: (i)Phrase structure grammar representing the hierarchical decomposition of the human body from whole to parts; (ii)Dependency grammar modeling the geometric articulation by a kinematic graph of the body pose; and (iii)Attribute grammar accounting for the compatibility relations between different parts in the hierarchy so that their appearances follow a consistent style. The parse graph outputs human detection, pose estimation, and attribute prediction simultaneously, which are intuitive and interpretable. We conduct experiments on two tasks on two datasets, and experimental results demonstrate the advantage of joint modeling in comparison with computing poses and attributes independently. Furthermore, our model obtains better performance over existing methods for both pose estimation and attribute prediction tasks.

  12. Pose-invariant face recognition using Markov random fields.

    Science.gov (United States)

    Ho, Huy Tho; Chellappa, Rama

    2013-04-01

    One of the key challenges for current face recognition techniques is how to handle pose variations between the probe and gallery face images. In this paper, we present a method for reconstructing the virtual frontal view from a given nonfrontal face image using Markov random fields (MRFs) and an efficient variant of the belief propagation algorithm. In the proposed approach, the input face image is divided into a grid of overlapping patches, and a globally optimal set of local warps is estimated to synthesize the patches at the frontal view. A set of possible warps for each patch is obtained by aligning it with images from a training database of frontal faces. The alignments are performed efficiently in the Fourier domain using an extension of the Lucas-Kanade algorithm that can handle illumination variations. The problem of finding the optimal warps is then formulated as a discrete labeling problem using an MRF. The reconstructed frontal face image can then be used with any face recognition technique. The two main advantages of our method are that it does not require manually selected facial landmarks or head pose estimation. In order to improve the performance of our pose normalization method in face recognition, we also present an algorithm for classifying whether a given face image is at a frontal or nonfrontal pose. Experimental results on different datasets are presented to demonstrate the effectiveness of the proposed approach.

  13. Problem Posing

    OpenAIRE

    Šilhavá, Marie

    2009-01-01

    This diploma thesis concentrates on problem posing from the students' point of view. Problem posing can be either seen as a teaching method which can be used in the class, or it can be used as a tool for researchers or teachers to assess the level of students' understanding of the topic. In my research, I compare three classes, one mathematics specialist class and two generalist classes, in their ability of problem posing. As an assessment tool it seemed that mathemathics specialists were abl...

  14. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications

    Directory of Open Access Journals (Sweden)

    Basam Musleh

    2016-09-01

    Full Text Available Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels and the vehicle environment (meters depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments.

  15. Pose-Invariant Face Recognition via RGB-D Images.

    Science.gov (United States)

    Sang, Gaoli; Li, Jing; Zhao, Qijun

    2016-01-01

    Three-dimensional (3D) face models can intrinsically handle large pose face recognition problem. In this paper, we propose a novel pose-invariant face recognition method via RGB-D images. By employing depth, our method is able to handle self-occlusion and deformation, both of which are challenging problems in two-dimensional (2D) face recognition. Texture images in the gallery can be rendered to the same view as the probe via depth. Meanwhile, depth is also used for similarity measure via frontalization and symmetric filling. Finally, both texture and depth contribute to the final identity estimation. Experiments on Bosphorus, CurtinFaces, Eurecom, and Kiwi databases demonstrate that the additional depth information has improved the performance of face recognition with large pose variations and under even more challenging conditions.

  16. Kernel PLS Estimation of Single-trial Event-related Potentials

    Science.gov (United States)

    Rosipal, Roman; Trejo, Leonard J.

    2004-01-01

    Nonlinear kernel partial least squaes (KPLS) regressior, is a novel smoothing approach to nonparametric regression curve fitting. We have developed a KPLS approach to the estimation of single-trial event related potentials (ERPs). For improved accuracy of estimation, we also developed a local KPLS method for situations in which there exists prior knowledge about the approximate latency of individual ERP components. To assess the utility of the KPLS approach, we compared non-local KPLS and local KPLS smoothing with other nonparametric signal processing and smoothing methods. In particular, we examined wavelet denoising, smoothing splines, and localized smoothing splines. We applied these methods to the estimation of simulated mixtures of human ERPs and ongoing electroencephalogram (EEG) activity using a dipole simulator (BESA). In this scenario we considered ongoing EEG to represent spatially and temporally correlated noise added to the ERPs. This simulation provided a reasonable but simplified model of real-world ERP measurements. For estimation of the simulated single-trial ERPs, local KPLS provided a level of accuracy that was comparable with or better than the other methods. We also applied the local KPLS method to the estimation of human ERPs recorded in an experiment on co,onitive fatigue. For these data, the local KPLS method provided a clear improvement in visualization of single-trial ERPs as well as their averages. The local KPLS method may serve as a new alternative to the estimation of single-trial ERPs and improvement of ERP averages.

  17. Pose Estimation using a Hierarchical 3D Representation of Contours and Surfaces

    DEFF Research Database (Denmark)

    Buch, Anders Glent; Kraft, Dirk; Kämäräinen, Joni-Kristian

    2013-01-01

    We present a system for detecting the pose of rigid objects using texture and contour information. From a stereo image view of a scene, a sparse hierarchical scene representation is reconstructed using an early cognitive vision system. We define an object model in terms of a simple context...

  18. Pose Estimation with a Kinect for Ergonomic Studies: Evaluation of the Accuracy Using a Virtual Mannequin

    Directory of Open Access Journals (Sweden)

    Pierre Plantard

    2015-01-01

    Full Text Available Analyzing human poses with a Kinect is a promising method to evaluate potentials risks of musculoskeletal disorders at workstations. In ecological situations, complex 3D poses and constraints imposed by the environment make it difficult to obtain reliable kinematic information. Thus, being able to predict the potential accuracy of the measurement for such complex 3D poses and sensor placements is challenging in classical experimental setups. To tackle this problem, we propose a new evaluation method based on a virtual mannequin. In this study, we apply this method to the evaluation of joint positions (shoulder, elbow, and wrist, joint angles (shoulder and elbow, and the corresponding RULA (a popular ergonomics assessment grid upper-limb score for a large set of poses and sensor placements. Thanks to this evaluation method, more than 500,000 configurations have been automatically tested, which would be almost impossible to evaluate with classical protocols. The results show that the kinematic information obtained by the Kinect software is generally accurate enough to fill in ergonomic assessment grids. However inaccuracy strongly increases for some specific poses and sensor positions. Using this evaluation method enabled us to report configurations that could lead to these high inaccuracies. As a supplementary material, we provide a software tool to help designers to evaluate the expected accuracy of this sensor for a set of upper-limb configurations. Results obtained with the virtual mannequin are in accordance with those obtained from a real subject for a limited set of poses and sensor placements.

  19. Comparison On Matching Methods Used In Pose Tracking For 3D Shape Representation

    Directory of Open Access Journals (Sweden)

    Khin Kyu Kyu Win

    2017-01-01

    Full Text Available In this work three different algorithms such as Brute Force Delaunay Triangulation and k-d Tree are analyzed on matching comparison for 3D shape representation. It is intended for developing the pose tracking of moving objects in video surveillance. To determine 3D pose of moving objects some tracking system may require full 3D pose estimation of arbitrarily shaped objects in real time. In order to perform 3D pose estimation in real time each step in the tracking algorithm must be computationally efficient. This paper presents method comparison for the computationally efficient registration of 3D shapes including free-form surfaces. Matching of free-form surfaces are carried out by using geometric point matching algorithm ICP. Several aspects of the ICP algorithm are investigated and analyzed by using specified surface setup. The surface setup processed in this system is represented by simple geometric primitive dealing with objects of free-from shape. Considered representations are a cloud of points.

  20. LEVELING STUDENTS’ CREATIVE THINKING IN SOLVING AND POSING MATHEMATICAL PROBLEM

    Directory of Open Access Journals (Sweden)

    Tatag Yuli Eko Siswono

    2010-07-01

    Full Text Available Many researchers assume that people are creative, but their degree ofcreativity is different. The notion of creative thinking level has beendiscussed .by experts. The perspective of mathematics creative thinkingrefers to a combination of logical and divergent thinking which is basedon intuition but has a conscious aim. The divergent thinking is focusedon flexibility, fluency, and novelty in mathematical problem solving andproblem posing. As students have various backgrounds and differentabilities, they possess different potential in thinking patterns,imagination, fantasy and performance; therefore, students have differentlevels of creative thinking. A research study was conducted in order todevelop a framework for students’ levels of creative thinking inmathematics. This research used a qualitative approach to describe thecharacteristics of the levels of creative thinking. Task-based interviewswere conducted to collect data with ten 8thgrade junior secondary schoolstudents. The results distinguished five levels of creative thinking,namely level 0 to level 4 with different characteristics in each level.These differences are based on fluency, flexibility, and novelty inmathematical problem solving and problem posing.Keywords: student’s creative thinking, problem posing, flexibility,fluency, novelty DOI: http://dx.doi.org/10.22342/jme.1.1.794.17-40

  1. Yoga Poses Increase Subjective Energy and State Self-Esteem in Comparison to 'Power Poses'.

    Science.gov (United States)

    Golec de Zavala, Agnieszka; Lantos, Dorottya; Bowden, Deborah

    2017-01-01

    Research on beneficial consequences of yoga focuses on the effects of yogic breathing and meditation. Less is known about the psychological effects of performing yoga postures. The present study investigated the effects of yoga poses on subjective sense of energy and self-esteem. The effects of yoga postures were compared to the effects of 'power poses,' which arguably increase the sense of power and self-confidence due to their association with interpersonal dominance (Carney et al., 2010). The study tested the novel prediction that yoga poses, which are not associated with interpersonal dominance but increase bodily energy, would increase the subjective feeling of energy and therefore increase self-esteem compared to 'high power' and 'low power' poses. A two factorial, between participants design was employed. Participants performed either two standing yoga poses with open front of the body ( n = 19), two standing yoga poses with covered front of the body ( n = 22), two expansive, high power poses ( n = 21), or two constrictive, low power poses ( n = 20) for 1-min each. The results showed that yoga poses in comparison to 'power poses' increased self-esteem. This effect was mediated by an increased subjective sense of energy and was observed when baseline trait self-esteem was controlled for. These results suggest that the effects of performing open, expansive body postures may be driven by processes other than the poses' association with interpersonal power and dominance. This study demonstrates that positive effects of yoga practice can occur after performing yoga poses for only 2 min.

  2. An algebraic perspective to single-transponder underwater navigation

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Reger, Johann

    This paper studies the position estimation of an underwater vehicle using a single acoustic transponder. The chosen estimation approach is based on nonlinear differential algebraic methods which allow to express very simply conditions for observability. These are then used in combination with an ...... with an integrator-based time-derivative estimation technique to design an algebraic estimator, which, contrary to asymptotic observers, does not require sometimes tedious convergence verification. Simple simulation results are presented to illustrate the approach....

  3. Inclusion estimation from a single electrostatic boundary measurement

    DEFF Research Database (Denmark)

    Karamehmedovic, Mirza; Knudsen, Kim

    2013-01-01

    We present a numerical method for the detection and estimation of perfectly conducting inclusions in conducting homogeneous host media in . The estimation is based on the evaluation of an indicator function that depends on a single pair of Cauchy data (electric potential and current) given at the...

  4. Multi-Task Convolutional Neural Network for Pose-Invariant Face Recognition

    Science.gov (United States)

    Yin, Xi; Liu, Xiaoming

    2018-02-01

    This paper explores multi-task learning (MTL) for face recognition. We answer the questions of how and why MTL can improve the face recognition performance. First, we propose a multi-task Convolutional Neural Network (CNN) for face recognition where identity classification is the main task and pose, illumination, and expression estimations are the side tasks. Second, we develop a dynamic-weighting scheme to automatically assign the loss weight to each side task, which is a crucial problem in MTL. Third, we propose a pose-directed multi-task CNN by grouping different poses to learn pose-specific identity features, simultaneously across all poses. Last but not least, we propose an energy-based weight analysis method to explore how CNN-based MTL works. We observe that the side tasks serve as regularizations to disentangle the variations from the learnt identity features. Extensive experiments on the entire Multi-PIE dataset demonstrate the effectiveness of the proposed approach. To the best of our knowledge, this is the first work using all data in Multi-PIE for face recognition. Our approach is also applicable to in-the-wild datasets for pose-invariant face recognition and achieves comparable or better performance than state of the art on LFW, CFP, and IJB-A datasets.

  5. Boneless Pose Editing and Animation

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Hansen, Kristian Evers; Erleben, Kenny

    2007-01-01

    In this paper, we propose a pose editing and animation method for triangulated surfaces based on a user controlled partitioning of the model into deformable parts and rigid parts which are denoted handles. In our pose editing system, the user can sculpt a set of poses simply by transforming...... the handles for each pose. Using Laplacian editing, the deformable parts are deformed to match the handles. In our animation system the user can constrain one or several handles in order to define a new pose. New poses are interpolated from the examples poses, by solving a small non-linear optimization...... problem in order to obtain the interpolation weights. While the system can be used simply for building poses, it is also an animation system. The user can specify a path for a given constraint and the model is animated correspondingly....

  6. IMU-based Real-time Pose Measurement system for Anterior Pelvic Plane in Total Hip Replacement Surgeries.

    Science.gov (United States)

    Zhe Cao; Shaojie Su; Hao Tang; Yixin Zhou; Zhihua Wang; Hong Chen

    2017-07-01

    With the aging of population, the number of Total Hip Replacement Surgeries (THR) increased year by year. In THR, inaccurate position of the implanted prosthesis may lead to the failure of the operation. In order to reduce the failure rate and acquire the real-time pose of Anterior Pelvic Plane (APP), we propose a measurement system in this paper. The measurement system includes two parts: Initial Pose Measurement Instrument (IPMI) and Real-time Pose Measurement Instrument (RPMI). IPMI is used to acquire the initial pose of the APP, and RPMI is used to estimate the real-time pose of the APP. Both are composed of an Inertial Measurement Unit (IMU) and magnetometer sensors. To estimate the attitude of the measurement system, the Extended Kalman Filter (EKF) is adopted in this paper. The real-time pose of the APP could be acquired together with the algorithm designed in the paper. The experiment results show that the Root Mean Square Error (RMSE) is within 1.6 degrees, which meets the requirement of THR operations.

  7. ONKALO POSE experiment. Phase 3: execution and monitoring

    International Nuclear Information System (INIS)

    Valli, J.; Hakala, M.; Wanne, T.; Kantia, P.; Siren, T.

    2014-01-01

    In-depth knowledge of the in situ stress state at the Olkiluoto site is critical for stability assessment both prior to and after deposition of spent nuclear fuel in order to understand and avoid potential damage to the rock at the site. Posiva's Olkiluoto Spalling Experiment (POSE) was designed specifically for this purpose with three primary goals: establish the in situ spalling/damage strength of Olkiluoto migmatitic gneiss, establish the state of in situ stress at the -345 m depth level and act as a Prediction-Outcome (P-O) exercise. Phases 1 and 2 of POSE are outlined in WR 2012-60. The objectives of the third phase of the POSE experiment are the same as the original objectives outlined above. This report outlines the execution and results of the third phase of the POSE experiment. The third phase of the experiment involved internally heating the third experimental hole (ONK-EH3) of the POSE niche in order to cause a symmetrical thermal stress increase around the hole due to the thermal expansion of rock. This thermomechanically induced stress increase, coupled with the estimated existing in situ stress state, should cause the maximum principal stress around the hole to exceed the predicted spalling strength of the rock around the hole. ONK-EH3 is located almost completely in pegmatitic granite. Four fractures near the top of the hole were mapped after boring ONK-EH3, and a tensile failure located at the contact between mica-rich gneiss and pegmatitic granite was observed 18 months after boring, prior to the experiment. Based on predictive calculations and the estimated in situ state of stress, the maximum principal stress magnitude should reach ca. 100 MPa when the temperature was just below 100 deg C after 12 weeks of heating. There were problems with the heater control unit at the beginning of the experiment, after which heating proceeded according to plan. The crack damage threshold of pegmatitic granite has been determined to be 85 ±17 MPa at Olkiluoto

  8. Single-snapshot DOA estimation by using Compressed Sensing

    Science.gov (United States)

    Fortunati, Stefano; Grasso, Raffaele; Gini, Fulvio; Greco, Maria S.; LePage, Kevin

    2014-12-01

    This paper deals with the problem of estimating the directions of arrival (DOA) of multiple source signals from a single observation vector of an array data. In particular, four estimation algorithms based on the theory of compressed sensing (CS), i.e., the classical ℓ 1 minimization (or Least Absolute Shrinkage and Selection Operator, LASSO), the fast smooth ℓ 0 minimization, and the Sparse Iterative Covariance-Based Estimator, SPICE and the Iterative Adaptive Approach for Amplitude and Phase Estimation, IAA-APES algorithms, are analyzed, and their statistical properties are investigated and compared with the classical Fourier beamformer (FB) in different simulated scenarios. We show that unlike the classical FB, a CS-based beamformer (CSB) has some desirable properties typical of the adaptive algorithms (e.g., Capon and MUSIC) even in the single snapshot case. Particular attention is devoted to the super-resolution property. Theoretical arguments and simulation analysis provide evidence that a CS-based beamformer can achieve resolution beyond the classical Rayleigh limit. Finally, the theoretical findings are validated by processing a real sonar dataset.

  9. Perspectives about family meals from single-headed and dual-headed households: a qualitative analysis.

    Science.gov (United States)

    Berge, Jerica M; Hoppmann, Caroline; Hanson, Carrie; Neumark-Sztainer, Dianne

    2013-12-01

    Cross-sectional and longitudinal research has shown that family meals are protective for adolescent healthful eating behaviors. However, little is known about what parents think of these findings and whether parents from single- vs dual-headed households have differing perspectives about the findings. In addition, parents' perspectives regarding barriers to applying the findings on family meals in their own homes and suggestions for more widespread adoption of the findings are unknown. The current study aimed to identify single- and dual-headed household parents' perspectives regarding the research findings on family meals, barriers to applying the findings in their own homes, and suggestions for helping families have more family meals. The current qualitative study included 59 parents who participated in substudy of two linked multilevel studies-EAT 2010 (Eating and Activity in Teens) and Families and Eating and Activity in Teens (F-EAT). Parents (91.5% female) were racially/ethnically and socioeconomically diverse. Data were analyzed using a grounded theory approach. Results from the current study suggest that parents from both single- and dual-headed households have similar perspectives regarding why family meals are protective for healthful eating habits for adolescents (eg, provides structure/routine, opportunities for communication, connection), but provide similar and different reasons for barriers to family meals (eg, single-headed=cost vs dual-headed=lack of creativity) and ideas and suggestions for how to increase the frequency of family meals (eg, single-headed=give fewer options vs dual-headed=include children in the meal preparation). Findings can help inform public health intervention researchers and providers who work with adolescents and their families to understand how to approach discussions regarding reasons for having family meals, barriers to carrying out family meals, and ways to increase family meals depending on family structure. Copyright

  10. Cloud computing approaches for prediction of ligand binding poses and pathways.

    Science.gov (United States)

    Lawrenz, Morgan; Shukla, Diwakar; Pande, Vijay S

    2015-01-22

    We describe an innovative protocol for ab initio prediction of ligand crystallographic binding poses and highly effective analysis of large datasets generated for protein-ligand dynamics. We include a procedure for setup and performance of distributed molecular dynamics simulations on cloud computing architectures, a model for efficient analysis of simulation data, and a metric for evaluation of model convergence. We give accurate binding pose predictions for five ligands ranging in affinity from 7 nM to > 200 μM for the immunophilin protein FKBP12, for expedited results in cases where experimental structures are difficult to produce. Our approach goes beyond single, low energy ligand poses to give quantitative kinetic information that can inform protein engineering and ligand design.

  11. "You're dealing with an emotionally charged individual...": an industry perspective on the challenges posed by medical tourists' informal caregiver-companions.

    Science.gov (United States)

    Casey, Victoria; Crooks, Valorie A; Snyder, Jeremy; Turner, Leigh

    2013-07-26

    Patients engage in medical tourism when they privately obtain a medical care abroad. Previous research shows that many medical tourists travel abroad with friends and family members who provide support and assistance. Meanwhile, very little is known about this important stakeholder group, referred to here as caregiver-companions. In this article we examine the challenges that can be posed by caregiver-companions and the overall practice of informal caregiving in medical tourism from an industry perspective. Specifically, we report on the findings of interviews conducted with international patient coordinators (IPCs) who work at destination facilities. IPCs come into regular contact with caregiver-companions in their professional positions and thus are ideally suited to comment on trends they have observed among this stakeholder group as well as the challenges they can pose to medical tourists, health workers, and facilities. We conducted 20 semi-structured interviews with 21 IPCs from 16 different facilities across nine countries. Topics probed in the interviews included caregiver-companion roles, IPCs' and others' interaction with caregiver-companions, and potential health and safety risks posed to medical tourists and caregiver-companions. Thematic analysis of the verbatim transcripts was employed. Although most participants encouraged medical tourists to travel with a caregiver-companion, many challenges associated with caregiver-companions were identified. Three themes best characterize the challenges that emerged: (1) caregiver-companions require time, attention and resources; (2) caregiver-companions can disrupt the provision of quality care; and (3) caregiver-companions can be exposed to risks. IPCs pointed out that caregiver-companions may, for example, have a negative impact on the patient through cost of accompaniment or inadequate care provision. Caregiver-companions may also create unanticipated or extra work for IPCs, as additional clients and by

  12. A review of cooperative and uncooperative spacecraft pose determination techniques for close-proximity operations

    Science.gov (United States)

    Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele

    2017-08-01

    The capability of an active spacecraft to accurately estimate its relative position and attitude (pose) with respect to an active/inactive, artificial/natural space object (target) orbiting in close-proximity is required to carry out various activities like formation flying, on-orbit servicing, active debris removal, and space exploration. According to the specific mission scenario, the pose determination task involves both theoretical and technological challenges related to the search for the most suitable algorithmic solution and sensor architecture, respectively. As regards the latter aspect, electro-optical sensors represent the best option as their use is compatible with mass and power limitation of micro and small satellites, and their measurements can be processed to estimate all the pose parameters. Overall, the degree of complexity of the challenges related to pose determination largely varies depending on the nature of the targets, which may be actively/passively cooperative, uncooperative but known, or uncooperative and unknown space objects. In this respect, while cooperative pose determination has been successfully demonstrated in orbit, the uncooperative case is still under study by universities, research centers, space agencies and private companies. However, in both the cases, the demand for space applications involving relative navigation maneuvers, also in close-proximity, for which pose determination capabilities are mandatory, is significantly increasing. In this framework, a review of state-of-the-art techniques and algorithms developed in the last decades for cooperative and uncooperative pose determination by processing data provided by electro-optical sensors is herein presented. Specifically, their main advantages and drawbacks in terms of achieved performance, computational complexity, and sensitivity to variability of pose and target geometry, are highlighted.

  13. An overview of age estimation in forensic anthropology: perspectives and practical considerations.

    Science.gov (United States)

    Márquez-Grant, Nicholas

    2015-01-01

    Information on methods of age estimation in physical anthropology, in particular with regard to age-at-death from human skeletal remains, is widely available in the literature. However, the practicalities and real challenges faced in forensic casework are not always highlighted. To provide a practitioner's perspective, regarding age estimation in forensic anthropology (both in the living as well as the dead), with an emphasis on the types of cases, the value of such work and its challenges and limitations. The paper reviews the current literature on age estimation with a focus on forensic anthropology, but it also brings the author's personal perspective derived from a number of forensic cases. Although much is known about what methods to use, but not always how to apply them, little attention has been given in the literature to the real practicalities faced by forensic anthropologists, for example: the challenges in different types of scenarios; how to report age estimations; responsibilities; and ethical concerns. This paper gathers some of these aspects into one overview which includes the value of such work and the practical challenges, not necessarily with the methods themselves, but also with regard to how these are applied in the different cases where age estimation is required.

  14. The art of problem posing

    CERN Document Server

    Brown, Stephen I

    1990-01-01

    Updated and expanded, this second edition satisfies the same philosophical objective as the first -- to show the importance of problem posing. Although interest in mathematical problem solving increased during the past decade, problem posing remained relatively ignored. The Art of Problem Posing draws attention to this equally important act and is the innovator in the field. Special features include: * an exploration ofthe logical relationship between problem posing and problem solving * a special chapter devoted to teaching problem posing as a separate course * sketches, drawings, diagrams, and cartoons that illustrate the schemes proposed * a special section on writing in mathematics.

  15. A Quality Evaluation of Single and Multiple Camera Calibration Approaches for an Indoor Multi Camera Tracking System

    Directory of Open Access Journals (Sweden)

    M. Adduci

    2014-06-01

    Full Text Available Human detection and tracking has been a prominent research area for several scientists around the globe. State of the art algorithms have been implemented, refined and accelerated to significantly improve the detection rate and eliminate false positives. While 2D approaches are well investigated, 3D human detection and tracking is still an unexplored research field. In both 2D/3D cases, introducing a multi camera system could vastly expand the accuracy and confidence of the tracking process. Within this work, a quality evaluation is performed on a multi RGB-D camera indoor tracking system for examining how camera calibration and pose can affect the quality of human tracks in the scene, independently from the detection and tracking approach used. After performing a calibration step on every Kinect sensor, state of the art single camera pose estimators were evaluated for checking how good the quality of the poses is estimated using planar objects such as an ordinate chessboard. With this information, a bundle block adjustment and ICP were performed for verifying the accuracy of the single pose estimators in a multi camera configuration system. Results have shown that single camera estimators provide high accuracy results of less than half a pixel forcing the bundle to converge after very few iterations. In relation to ICP, relative information between cloud pairs is more or less preserved giving a low score of fitting between concatenated pairs. Finally, sensor calibration proved to be an essential step for achieving maximum accuracy in the generated point clouds, and therefore in the accuracy of the produced 3D trajectories, from each sensor.

  16. A single model procedure for tank calibration function estimation

    International Nuclear Information System (INIS)

    York, J.C.; Liebetrau, A.M.

    1995-01-01

    Reliable tank calibrations are a vital component of any measurement control and accountability program for bulk materials in a nuclear reprocessing facility. Tank volume calibration functions used in nuclear materials safeguards and accountability programs are typically constructed from several segments, each of which is estimated independently. Ideally, the segments correspond to structural features in the tank. In this paper the authors use an extension of the Thomas-Liebetrau model to estimate the entire calibration function in a single step. This procedure automatically takes significant run-to-run differences into account and yields an estimate of the entire calibration function in one operation. As with other procedures, the first step is to define suitable calibration segments. Next, a polynomial of low degree is specified for each segment. In contrast with the conventional practice of constructing a separate model for each segment, this information is used to set up the design matrix for a single model that encompasses all of the calibration data. Estimation of the model parameters is then done using conventional statistical methods. The method described here has several advantages over traditional methods. First, modeled run-to-run differences can be taken into account automatically at the estimation step. Second, no interpolation is required between successive segments. Third, variance estimates are based on all the data, rather than that from a single segment, with the result that discontinuities in confidence intervals at segment boundaries are eliminated. Fourth, the restrictive assumption of the Thomas-Liebetrau method, that the measured volumes be the same for all runs, is not required. Finally, the proposed methods are readily implemented using standard statistical procedures and widely-used software packages

  17. An Updated Perspective of Single Event Gate Rupture and Single Event Burnout in Power MOSFETs

    Science.gov (United States)

    Titus, Jeffrey L.

    2013-06-01

    Studies over the past 25 years have shown that heavy ions can trigger catastrophic failure modes in power MOSFETs [e.g., single-event gate rupture (SEGR) and single-event burnout (SEB)]. In 1996, two papers were published in a special issue of the IEEE Transaction on Nuclear Science [Johnson, Palau, Dachs, Galloway and Schrimpf, “A Review of the Techniques Used for Modeling Single-Event Effects in Power MOSFETs,” IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 546-560, April. 1996], [Titus and Wheatley, “Experimental Studies of Single-Event Gate Rupture and Burnout in Vertical Power MOSFETs,” IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 533-545, Apr. 1996]. Those two papers continue to provide excellent information and references with regard to SEB and SEGR in vertical planar MOSFETs. This paper provides updated references/information and provides an updated perspective of SEB and SEGR in vertical planar MOSFETs as well as provides references/information to other device types that exhibit SEB and SEGR effects.

  18. Mixture of Regression Models with Single-Index

    OpenAIRE

    Xiang, Sijia; Yao, Weixin

    2016-01-01

    In this article, we propose a class of semiparametric mixture regression models with single-index. We argue that many recently proposed semiparametric/nonparametric mixture regression models can be considered special cases of the proposed model. However, unlike existing semiparametric mixture regression models, the new pro- posed model can easily incorporate multivariate predictors into the nonparametric components. Backfitting estimates and the corresponding algorithms have been proposed for...

  19. Application of structured support vector machine backpropagation to a convolutional neural network for human pose estimation.

    Science.gov (United States)

    Witoonchart, Peerajak; Chongstitvatana, Prabhas

    2017-08-01

    In this study, for the first time, we show how to formulate a structured support vector machine (SSVM) as two layers in a convolutional neural network, where the top layer is a loss augmented inference layer and the bottom layer is the normal convolutional layer. We show that a deformable part model can be learned with the proposed structured SVM neural network by backpropagating the error of the deformable part model to the convolutional neural network. The forward propagation calculates the loss augmented inference and the backpropagation calculates the gradient from the loss augmented inference layer to the convolutional layer. Thus, we obtain a new type of convolutional neural network called an Structured SVM convolutional neural network, which we applied to the human pose estimation problem. This new neural network can be used as the final layers in deep learning. Our method jointly learns the structural model parameters and the appearance model parameters. We implemented our method as a new layer in the existing Caffe library. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Pose Space Surface Manipulation

    Directory of Open Access Journals (Sweden)

    Yusuke Yoshiyasu

    2012-01-01

    Full Text Available Example-based mesh deformation techniques produce natural and realistic shapes by learning the space of deformations from examples. However, skeleton-based methods cannot manipulate a global mesh structure naturally, whereas the mesh-based approaches based on a translational control do not allow the user to edit a local mesh structure intuitively. This paper presents an example-driven mesh editing framework that achieves both global and local pose manipulations. The proposed system is built with a surface deformation method based on a two-step linear optimization technique and achieves direct manipulations of a model surface using translational and rotational controls. With the translational control, the user can create a model in natural poses easily. The rotational control can adjust the local pose intuitively by bending and twisting. We encode example deformations with a rotation-invariant mesh representation which handles large rotations in examples. To incorporate example deformations, we infer a pose from the handle translations/rotations and perform pose space interpolation, thereby avoiding involved nonlinear optimization. With the two-step linear approach combined with the proposed multiresolution deformation method, we can edit models at interactive rates without losing important deformation effects such as muscle bulging.

  1. Motion Estimation Using the Single-row Superposition-type Planar Compound-like Eye

    Directory of Open Access Journals (Sweden)

    Gwo-Long Lin

    2007-06-01

    Full Text Available How can the compound eye of insects capture the prey so accurately andquickly? This interesting issue is explored from the perspective of computer vision insteadof from the viewpoint of biology. The focus is on performance evaluation of noiseimmunity for motion recovery using the single-row superposition-type planar compound-like eye (SPCE. The SPCE owns a special symmetrical framework with tremendousamount of ommatidia inspired by compound eye of insects. The noise simulates possibleambiguity of image patterns caused by either environmental uncertainty or low resolutionof CCD devices. Results of extensive simulations indicate that this special visualconfiguration provides excellent motion estimation performance regardless of themagnitude of the noise. Even when the noise interference is serious, the SPCE is able todramatically reduce errors of motion recovery of the ego-translation without any type offilters. In other words, symmetrical, regular, and multiple vision sensing devices of thecompound-like eye have statistical averaging advantage to suppress possible noises. Thisdiscovery lays the basic foundation in terms of engineering approaches for the secret of thecompound eye of insects.

  2. Consistently Showing Your Best Side? Intra-individual Consistency in #Selfie Pose Orientation

    Science.gov (United States)

    Lindell, Annukka K.

    2017-01-01

    Painted and photographic portraits of others show an asymmetric bias: people favor their left cheek. Both experimental and database studies confirm that the left cheek bias extends to selfies. To date all such selfie studies have been cross-sectional; whether individual selfie-takers tend to consistently favor the same pose orientation, or switch between multiple poses, remains to be determined. The present study thus examined intra-individual consistency in selfie pose orientations. Two hundred selfie-taking participants (100 male and 100 female) were identified by searching #selfie on Instagram. The most recent 10 single-subject selfies for the each of the participants were selected and coded for type of selfie (normal; mirror) and pose orientation (left, midline, right), resulting in a sample of 2000 selfies. Results indicated that selfie-takers do tend to consistently adopt a preferred pose orientation (α = 0.72), with more participants showing an overall left cheek bias (41%) than would be expected by chance (overall right cheek bias = 31.5%; overall midline bias = 19.5%; no overall bias = 8%). Logistic regression modellng, controlling for the repeated measure of participant identity, indicated that sex did not affect pose orientation. However, selfie type proved a significant predictor when comparing left and right cheek poses, with a stronger left cheek bias for mirror than normal selfies. Overall, these novel findings indicate that selfie-takers show intra-individual consistency in pose orientation, and in addition, replicate the previously reported left cheek bias for selfies and other types of portrait, confirming that the left cheek bias also presents within individuals’ selfie corpora. PMID:28270790

  3. Extended Kalman filter-based methods for pose estimation using visual, inertial and magnetic sensors: comparative analysis and performance evaluation.

    Science.gov (United States)

    Ligorio, Gabriele; Sabatini, Angelo Maria

    2013-02-04

    In this paper measurements from a monocular vision system are fused with inertial/magnetic measurements from an Inertial Measurement Unit (IMU) rigidly connected to the camera. Two Extended Kalman filters (EKFs) were developed to estimate the pose of the IMU/camera sensor moving relative to a rigid scene (ego-motion), based on a set of fiducials. The two filters were identical as for the state equation and the measurement equations of the inertial/magnetic sensors. The DLT-based EKF exploited visual estimates of the ego-motion using a variant of the Direct Linear Transformation (DLT) method; the error-driven EKF exploited pseudo-measurements based on the projection errors from measured two-dimensional point features to the corresponding three-dimensional fiducials. The two filters were off-line analyzed in different experimental conditions and compared to a purely IMU-based EKF used for estimating the orientation of the IMU/camera sensor. The DLT-based EKF was more accurate than the error-driven EKF, less robust against loss of visual features, and equivalent in terms of computational complexity. Orientation root mean square errors (RMSEs) of 1° (1.5°), and position RMSEs of 3.5 mm (10 mm) were achieved in our experiments by the DLT-based EKF (error-driven EKF); by contrast, orientation RMSEs of 1.6° were achieved by the purely IMU-based EKF.

  4. Optical neural network system for pose determination of spinning satellites

    Science.gov (United States)

    Lee, Andrew; Casasent, David

    1990-01-01

    An optical neural network architecture and algorithm based on a Hopfield optimization network are presented for multitarget tracking. This tracker utilizes a neuron for every possible target track, and a quadratic energy function of neural activities which is minimized using gradient descent neural evolution. The neural net tracker is demonstrated as part of a system for determining position and orientation (pose) of spinning satellites with respect to a robotic spacecraft. The input to the system is time sequence video from a single camera. Novelty detection and filtering are utilized to locate and segment novel regions from the input images. The neural net multitarget tracker determines the correspondences (or tracks) of the novel regions as a function of time, and hence the paths of object (satellite) parts. The path traced out by a given part or region is approximately elliptical in image space, and the position, shape and orientation of the ellipse are functions of the satellite geometry and its pose. Having a geometric model of the satellite, and the elliptical path of a part in image space, the three-dimensional pose of the satellite is determined. Digital simulation results using this algorithm are presented for various satellite poses and lighting conditions.

  5. Multiple linear regression to estimate time-frequency electrophysiological responses in single trials.

    Science.gov (United States)

    Hu, L; Zhang, Z G; Mouraux, A; Iannetti, G D

    2015-05-01

    Transient sensory, motor or cognitive event elicit not only phase-locked event-related potentials (ERPs) in the ongoing electroencephalogram (EEG), but also induce non-phase-locked modulations of ongoing EEG oscillations. These modulations can be detected when single-trial waveforms are analysed in the time-frequency domain, and consist in stimulus-induced decreases (event-related desynchronization, ERD) or increases (event-related synchronization, ERS) of synchrony in the activity of the underlying neuronal populations. ERD and ERS reflect changes in the parameters that control oscillations in neuronal networks and, depending on the frequency at which they occur, represent neuronal mechanisms involved in cortical activation, inhibition and binding. ERD and ERS are commonly estimated by averaging the time-frequency decomposition of single trials. However, their trial-to-trial variability that can reflect physiologically-important information is lost by across-trial averaging. Here, we aim to (1) develop novel approaches to explore single-trial parameters (including latency, frequency and magnitude) of ERP/ERD/ERS; (2) disclose the relationship between estimated single-trial parameters and other experimental factors (e.g., perceived intensity). We found that (1) stimulus-elicited ERP/ERD/ERS can be correctly separated using principal component analysis (PCA) decomposition with Varimax rotation on the single-trial time-frequency distributions; (2) time-frequency multiple linear regression with dispersion term (TF-MLRd) enhances the signal-to-noise ratio of ERP/ERD/ERS in single trials, and provides an unbiased estimation of their latency, frequency, and magnitude at single-trial level; (3) these estimates can be meaningfully correlated with each other and with other experimental factors at single-trial level (e.g., perceived stimulus intensity and ERP magnitude). The methods described in this article allow exploring fully non-phase-locked stimulus-induced cortical

  6. “You’re dealing with an emotionally charged individual…”: an industry perspective on the challenges posed by medical tourists’ informal caregiver-companions

    Science.gov (United States)

    2013-01-01

    Background Patients engage in medical tourism when they privately obtain a medical care abroad. Previous research shows that many medical tourists travel abroad with friends and family members who provide support and assistance. Meanwhile, very little is known about this important stakeholder group, referred to here as caregiver-companions. In this article we examine the challenges that can be posed by caregiver-companions and the overall practice of informal caregiving in medical tourism from an industry perspective. Specifically, we report on the findings of interviews conducted with international patient coordinators (IPCs) who work at destination facilities. IPCs come into regular contact with caregiver-companions in their professional positions and thus are ideally suited to comment on trends they have observed among this stakeholder group as well as the challenges they can pose to medical tourists, health workers, and facilities. Methods We conducted 20 semi-structured interviews with 21 IPCs from 16 different facilities across nine countries. Topics probed in the interviews included caregiver-companion roles, IPCs’ and others’ interaction with caregiver-companions, and potential health and safety risks posed to medical tourists and caregiver-companions. Thematic analysis of the verbatim transcripts was employed. Results Although most participants encouraged medical tourists to travel with a caregiver-companion, many challenges associated with caregiver-companions were identified. Three themes best characterize the challenges that emerged: (1) caregiver-companions require time, attention and resources; (2) caregiver-companions can disrupt the provision of quality care; and (3) caregiver-companions can be exposed to risks. IPCs pointed out that caregiver-companions may, for example, have a negative impact on the patient through cost of accompaniment or inadequate care provision. Caregiver-companions may also create unanticipated or extra work for IPCs, as

  7. Dynamic Human Body Modeling Using a Single RGB Camera.

    Science.gov (United States)

    Zhu, Haiyu; Yu, Yao; Zhou, Yu; Du, Sidan

    2016-03-18

    In this paper, we present a novel automatic pipeline to build personalized parametric models of dynamic people using a single RGB camera. Compared to previous approaches that use monocular RGB images, our system can model a 3D human body automatically and incrementally, taking advantage of human motion. Based on coarse 2D and 3D poses estimated from image sequences, we first perform a kinematic classification of human body parts to refine the poses and obtain reconstructed body parts. Next, a personalized parametric human model is generated by driving a general template to fit the body parts and calculating the non-rigid deformation. Experimental results show that our shape estimation method achieves comparable accuracy with reconstructed models using depth cameras, yet requires neither user interaction nor any dedicated devices, leading to the feasibility of using this method on widely available smart phones.

  8. Single-Channel Noise Reduction using Unified Joint Diagonalization and Optimal Filtering

    DEFF Research Database (Denmark)

    Nørholm, Sidsel Marie; Benesty, Jacob; Jensen, Jesper Rindom

    2014-01-01

    consider two cases, where, respectively, no distortion and distortion are incurred on the desired signal. The former can be achieved when the covariance matrix of the desired signal is rank deficient, which is the case, for example, for voiced speech. In the latter case, the covariance matrix......In this paper, the important problem of single-channel noise reduction is treated from a new perspective. The problem is posed as a filtering problem based on joint diagonalization of the covariance matrices of the desired and noise signals. More specifically, the eigenvectors from the joint...

  9. Automatic generation of statistical pose and shape models for articulated joints.

    Science.gov (United States)

    Xin Chen; Graham, Jim; Hutchinson, Charles; Muir, Lindsay

    2014-02-01

    Statistical analysis of motion patterns of body joints is potentially useful for detecting and quantifying pathologies. However, building a statistical motion model across different subjects remains a challenging task, especially for a complex joint like the wrist. We present a novel framework for simultaneous registration and segmentation of multiple 3-D (CT or MR) volumes of different subjects at various articulated positions. The framework starts with a pose model generated from 3-D volumes captured at different articulated positions of a single subject (template). This initial pose model is used to register the template volume to image volumes from new subjects. During this process, the Grow-Cut algorithm is used in an iterative refinement of the segmentation of the bone along with the pose parameters. As each new subject is registered and segmented, the pose model is updated, improving the accuracy of successive registrations. We applied the algorithm to CT images of the wrist from 25 subjects, each at five different wrist positions and demonstrated that it performed robustly and accurately. More importantly, the resulting segmentations allowed a statistical pose model of the carpal bones to be generated automatically without interaction. The evaluation results show that our proposed framework achieved accurate registration with an average mean target registration error of 0.34 ±0.27 mm. The automatic segmentation results also show high consistency with the ground truth obtained semi-automatically. Furthermore, we demonstrated the capability of the resulting statistical pose and shape models by using them to generate a measurement tool for scaphoid-lunate dissociation diagnosis, which achieved 90% sensitivity and specificity.

  10. Pengenalan Pose Tangan Menggunakan HuMoment

    Directory of Open Access Journals (Sweden)

    Dina Budhi Utami

    2017-02-01

    Full Text Available Computer vision yang didasarkan pada pengenalan bentuk memiliki banyak potensi dalam interaksi manusia dan komputer. Pose tangan dapat dijadikan simbol interaksi manusia dengan komputer seperti halnya pada penggunaan berbagai pose tangan pada bahasa isyarat. Berbagai pose tangan dapat digunakan untuk menggantikan fungsi mouse, untuk mengendalikan robot, dan sebagainya. Penelitian ini difokuskan pada pembangunan sistem pengenalan pose tangan menggunakan HuMoment. Proses pengenalan pose tangan dimulai dengan melakukan segmentasi citra masukan untuk menghasilkan citra ROI (Region of Interest yaitu area telapak tangan. Selanjutnya dilakukan proses deteksi tepi. Kemudian dilakukan ekstraksi nilai HuMoment. Nilai HuMoment dikuantisasikan ke dalam bukukode yang dihasilkan dari proses pelatihan menggunakan K-Means. Proses kuantisasi dilakukan dengan menghitung nilai Euclidean Distance terkecil antara nilai HuMomment citra masukan dan bukukode. Berdasarkan hasil penelitian, nilai akurasi sistem dalam mengenali pose tangan adalah 88.57%.

  11. A Single Camera Motion Capture System for Human-Computer Interaction

    Science.gov (United States)

    Okada, Ryuzo; Stenger, Björn

    This paper presents a method for markerless human motion capture using a single camera. It uses tree-based filtering to efficiently propagate a probability distribution over poses of a 3D body model. The pose vectors and associated shapes are arranged in a tree, which is constructed by hierarchical pairwise clustering, in order to efficiently evaluate the likelihood in each frame. Anew likelihood function based on silhouette matching is proposed that improves the pose estimation of thinner body parts, i. e. the limbs. The dynamic model takes self-occlusion into account by increasing the variance of occluded body-parts, thus allowing for recovery when the body part reappears. We present two applications of our method that work in real-time on a Cell Broadband Engine™: a computer game and a virtual clothing application.

  12. Estimating accidental coincidences for pixelated PET detectors and singles list-mode acquisition

    International Nuclear Information System (INIS)

    Rafecas, M.; Torres, I.; Spanoudaki, V.; McElroy, D.P.; Ziegler, S.I.

    2007-01-01

    We have studied the validity of random estimation techniques for various low energy thresholds (LETs) and single list-mode data sets in small animal PET. While a LET below 255 keV helps to increase the sensitivity, it also results in an increase of random coincidences and inter-crystal scatter (ICS). The study is carried out for MADPET-II, a dual-layer positron emission tomography (PET) scanner prototype consisting of LSO crystals read out individually by APDs. The data are acquired in singles list-mode format, and coincidences are computed post-acquisition. To estimate randoms, we have used the delayed coincidence window method (DW), and the singles rate model (SR). Various phantoms were simulated using GATE. For LETs under 255 keV, the number of random events R, estimated using the SR and the DW methods, is larger than the number of randoms which was directly computed from GATE simulations, and R(SR)>R(DW)>R(GATE). The higher the LET, the smaller the overestimation. For LETs >255 keV, R(DW)/R(GATE) ∼1. If scattered singles were excluded from the file, this discrepancy between R(DW or SR) and R(GATE) significantly diminished. This fact points out to ICS as the effect responsible for the mismatch, since for LETs lower than 255 keV, all singles related to an ICS event can be detected independently, thus altering the singles rate. Therefore, if low LETs are used, random estimation techniques should account for ICS

  13. A cross docking pipeline for improving pose prediction and virtual screening performance

    Science.gov (United States)

    Kumar, Ashutosh; Zhang, Kam Y. J.

    2018-01-01

    Pose prediction and virtual screening performance of a molecular docking method depend on the choice of protein structures used for docking. Multiple structures for a target protein are often used to take into account the receptor flexibility and problems associated with a single receptor structure. However, the use of multiple receptor structures is computationally expensive when docking a large library of small molecules. Here, we propose a new cross-docking pipeline suitable to dock a large library of molecules while taking advantage of multiple target protein structures. Our method involves the selection of a suitable receptor for each ligand in a screening library utilizing ligand 3D shape similarity with crystallographic ligands. We have prospectively evaluated our method in D3R Grand Challenge 2 and demonstrated that our cross-docking pipeline can achieve similar or better performance than using either single or multiple-receptor structures. Moreover, our method displayed not only decent pose prediction performance but also better virtual screening performance over several other methods.

  14. Estimating single molecule conductance from spontaneous evolution of a molecular contact

    Science.gov (United States)

    Gil, M.; Malinowski, T.; Iazykov, M.; Klein, H. R.

    2018-03-01

    We present an original method to estimate the conductivity of a single molecule anchored to nanometric-sized metallic electrodes, using a Mechanically Controlled Break Junction operated at room temperature in the liquid. We record the conductance through the metal/molecules/metal nanocontact while keeping the metallic electrodes at a fixed distance. Taking advantage of thermal diffusion and electromigration, we let the contact naturally explore the more stable configurations around a chosen conductance value. The conductance of a single molecule is estimated from a statistical analysis of raw conductance and conductance standard deviation data for molecular contacts containing up to 14 molecules. The single molecule conductance values are interpreted as time-averaged conductance of an ensemble of conformers at thermal equilibrium.

  15. Realtime Reconstruction of an Animating Human Body from a Single Depth Camera.

    Science.gov (United States)

    Chen, Yin; Cheng, Zhi-Quan; Lai, Chao; Martin, Ralph R; Dang, Gang

    2016-08-01

    We present a method for realtime reconstruction of an animating human body,which produces a sequence of deforming meshes representing a given performance captured by a single commodity depth camera. We achieve realtime single-view mesh completion by enhancing the parameterized SCAPE model.Our method, which we call Realtime SCAPE, performs full-body reconstruction without the use of markers.In Realtime SCAPE, estimations of body shape parameters and pose parameters, needed for reconstruction, are decoupled. Intrinsic body shape is first precomputed for a given subject, by determining shape parameters with the aid of a body shape database. Subsequently, per-frame pose parameter estimation is performed by means of linear blending skinning (LBS); the problem is decomposed into separately finding skinning weights and transformations. The skinning weights are also determined offline from the body shape database,reducing online reconstruction to simply finding the transformations in LBS. Doing so is formulated as a linear variational problem;carefully designed constraints are used to impose temporal coherence and alleviate artifacts. Experiments demonstrate that our method can produce full-body mesh sequences with high fidelity.

  16. DeepQA: improving the estimation of single protein model quality with deep belief networks.

    Science.gov (United States)

    Cao, Renzhi; Bhattacharya, Debswapna; Hou, Jie; Cheng, Jianlin

    2016-12-05

    Protein quality assessment (QA) useful for ranking and selecting protein models has long been viewed as one of the major challenges for protein tertiary structure prediction. Especially, estimating the quality of a single protein model, which is important for selecting a few good models out of a large model pool consisting of mostly low-quality models, is still a largely unsolved problem. We introduce a novel single-model quality assessment method DeepQA based on deep belief network that utilizes a number of selected features describing the quality of a model from different perspectives, such as energy, physio-chemical characteristics, and structural information. The deep belief network is trained on several large datasets consisting of models from the Critical Assessment of Protein Structure Prediction (CASP) experiments, several publicly available datasets, and models generated by our in-house ab initio method. Our experiments demonstrate that deep belief network has better performance compared to Support Vector Machines and Neural Networks on the protein model quality assessment problem, and our method DeepQA achieves the state-of-the-art performance on CASP11 dataset. It also outperformed two well-established methods in selecting good outlier models from a large set of models of mostly low quality generated by ab initio modeling methods. DeepQA is a useful deep learning tool for protein single model quality assessment and protein structure prediction. The source code, executable, document and training/test datasets of DeepQA for Linux is freely available to non-commercial users at http://cactus.rnet.missouri.edu/DeepQA/ .

  17. Inverse Free Iterative Methods for Nonlinear Ill-Posed Operator Equations

    Directory of Open Access Journals (Sweden)

    Ioannis K. Argyros

    2014-01-01

    ill-posed operator equation F(x=y. The proposed method is a modified form of Tikhonov gradient (TIGRA method considered by Ramlau (2003. The regularization parameter is chosen according to the balancing principle considered by Pereverzev and Schock (2005. The error estimate is derived under a general source condition and is of optimal order. Some numerical examples involving integral equations are also given in this paper.

  18. Velocity estimation of an airplane through a single satellite image

    Institute of Scientific and Technical Information of China (English)

    Zhuxin Zhao; Gongjian Wen; Bingwei Hui; Deren Li

    2012-01-01

    The motion information of a moving target can be recorded in a single image by a push-broom satellite. A push-broom satellite image is composed of many image lines sensed at different time instants. A method to estimate the velocity of a flying airplane from a single image based on the imagery model of the linear push-broom sensor is proposed. Some key points on the high-resolution image of the plane are chosen to determine the velocity (speed and direction). The performance of the method is tested and verified by experiments using a WorldView-1 image.%The motion information of a moving target can be recorded in a single image by a push-broom satellite.A push-broom satellite image is composed of many image lines sensed at different time instants.A method to estimate the velocity of a flying airplane from a single image based on the imagery model of the linear push-broom sensor is proposed.Some key points on the high-resolution image of the plane are chosen to determine the velocity (speed and direction).The performance of the method is tested and verified by experiments using a WorldView-1 image.

  19. Problem posing reflections and applications

    CERN Document Server

    Brown, Stephen I

    2014-01-01

    As a result of the editors' collaborative teaching at Harvard in the late 1960s, they produced a ground-breaking work -- The Art Of Problem Posing -- which related problem posing strategies to the already popular activity of problem solving. It took the concept of problem posing and created strategies for engaging in that activity as a central theme in mathematics education. Based in part upon that work and also upon a number of articles by its authors, other members of the mathematics education community began to apply and expand upon their ideas. This collection of thirty readings is a tes

  20. An extended set-value observer for position estimation using single range measurements

    DEFF Research Database (Denmark)

    Marcal, Jose; Jouffroy, Jerome; Fossen, Thor I.

    the observability of the system is briefly discussed and an extended set-valued observer is presented, with some discussion about the effect of the measurements noise on the final solution. This observer estimates bounds in the errors assuming that the exogenous signals are bounded, providing a safe region......The ability of estimating the position of an underwater vehicle from single range measurements is important in applications where one transducer marks an important geographical point, when there is a limitation in the size or cost of the vehicle, or when there is a failure in a system...... of transponders. The knowledge of the bearing of the vehicle and the range measurements from a single location can provide a solution which is sensitive to the trajectory that the vehicle is following, since there is no complete constraint on the position estimate with a single beacon. In this paper...

  1. Perspectives on radiation dose estimates for A-bomb survivors

    International Nuclear Information System (INIS)

    Loewe, W.E.

    1987-01-01

    For decades after the actual events, quantitative characterization of the radiation fields at Hiroshima and Nagasaki continues to be sought, with high accuracy a goal justified by the unique contribution to radiation protection standards that is represented by the medical records of exposed survivors. The most recent effort is distinguished by its reliance on computer modelling and concomitant detail, and by its decentralized direction, both internationally and internally to the U.S. and Japan, with resultant ongoing peer review and wide scope of inquiry. A new system for individual dose estimation has been agreed upon, and its scientific basis has been elaborated in the literature as well as in a comprehensive treatise to be published in the Spring of 1987. In perspective, this new system appears to be an unusually successful achievement that offers the expectation of reliable estimates with the desired accuracy. Some aspects leading to this expectation, along with a caveat, are discussed here

  2. Perspectives on radiation dose estimates for A-bomb survivors

    International Nuclear Information System (INIS)

    Loewe, W.E.

    1986-12-01

    Four decades after the actual events, quantitative characterization of the radiation fields at Hiroshima and Nagasaki continues to be sought, with high accuracy a goal justified by the unique contribution to radiation protection standards that is represented by the medical records of exposed survivors. The most recent effort is distinguished by its reliance on computer modeling and concomitant detail, and by its decentralized direction, both internationally and internally to the US and Japan, with resultant ongoing peer review and wide scope of inquiry. A new system for individual dose estimation has been agreed upon, and its scientific basis has been elaborated in the literature as well as in a comprehensive treatise to be published in the Spring of 1987. In perspective, this new system appears to be an unusually successful achievement that offers the expectation of reliable estimates with the desired accuracy. Some aspects leading to this expectation, along with a caveat, are discussed here. 4 refs., 8 figs., 3 tabs

  3. Web-based visualisation of head pose and facial expressions changes: monitoring human activity using depth data

    OpenAIRE

    Kalliatakis, Grigorios; Vidakis, Nikolaos; Triantafyllidis, Georgios

    2017-01-01

    Despite significant recent advances in the field of head pose estimation and facial expression recognition, raising the cognitive level when analysing human activity presents serious challenges to current concepts. Motivated by the need of generating comprehensible visual representations from different sets of data, we introduce a system capable of monitoring human activity through head pose and facial expression changes, utilising an affordable 3D sensing technology (Microsoft Kinect sensor)...

  4. Estimating intrinsic and extrinsic noise from single-cell gene expression measurements

    Science.gov (United States)

    Fu, Audrey Qiuyan; Pachter, Lior

    2017-01-01

    Gene expression is stochastic and displays variation (“noise”) both within and between cells. Intracellular (intrinsic) variance can be distinguished from extracellular (extrinsic) variance by applying the law of total variance to data from two-reporter assays that probe expression of identically regulated gene pairs in single cells. We examine established formulas [Elowitz, M. B., A. J. Levine, E. D. Siggia and P. S. Swain (2002): “Stochastic gene expression in a single cell,” Science, 297, 1183–1186.] for the estimation of intrinsic and extrinsic noise and provide interpretations of them in terms of a hierarchical model. This allows us to derive alternative estimators that minimize bias or mean squared error. We provide a geometric interpretation of these results that clarifies the interpretation in [Elowitz, M. B., A. J. Levine, E. D. Siggia and P. S. Swain (2002): “Stochastic gene expression in a single cell,” Science, 297, 1183–1186.]. We also demonstrate through simulation and re-analysis of published data that the distribution assumptions underlying the hierarchical model have to be satisfied for the estimators to produce sensible results, which highlights the importance of normalization. PMID:27875323

  5. GAGG:ce single crystalline films: New perspective scintillators for electron detection in SEM.

    Science.gov (United States)

    Bok, Jan; Lalinský, Ondřej; Hanuš, Martin; Onderišinová, Zuzana; Kelar, Jakub; Kučera, Miroslav

    2016-04-01

    Single crystal scintillators are frequently used for electron detection in scanning electron microscopy (SEM). We report gadolinium aluminum gallium garnet (GAGG:Ce) single crystalline films as a new perspective scintillators for the SEM. For the first time, the epitaxial garnet films were used in a practical application: the GAGG:Ce scintillator was incorporated into a SEM scintillation electron detector and it showed improved image quality. In order to prove the GAGG:Ce quality accurately, the scintillation properties were examined using electron beam excitation and compared with frequently used scintillators in the SEM. The results demonstrate excellent emission efficiency of the GAGG:Ce single crystalline films together with their very fast scintillation decay useful for demanding SEM applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Handheld pose tracking using vision-inertial sensors with occlusion handling

    Science.gov (United States)

    Li, Juan; Slembrouck, Maarten; Deboeverie, Francis; Bernardos, Ana M.; Besada, Juan A.; Veelaert, Peter; Aghajan, Hamid; Casar, José R.; Philips, Wilfried

    2016-07-01

    Tracking of a handheld device's three-dimensional (3-D) position and orientation is fundamental to various application domains, including augmented reality (AR), virtual reality, and interaction in smart spaces. Existing systems still offer limited performance in terms of accuracy, robustness, computational cost, and ease of deployment. We present a low-cost, accurate, and robust system for handheld pose tracking using fused vision and inertial data. The integration of measurements from embedded accelerometers reduces the number of unknown parameters in the six-degree-of-freedom pose calculation. The proposed system requires two light-emitting diode (LED) markers to be attached to the device, which are tracked by external cameras through a robust algorithm against illumination changes. Three data fusion methods have been proposed, including the triangulation-based stereo-vision system, constraint-based stereo-vision system with occlusion handling, and triangulation-based multivision system. Real-time demonstrations of the proposed system applied to AR and 3-D gaming are also included. The accuracy assessment of the proposed system is carried out by comparing with the data generated by the state-of-the-art commercial motion tracking system OptiTrack. Experimental results show that the proposed system has achieved high accuracy of few centimeters in position estimation and few degrees in orientation estimation.

  7. Privilege as a Social Determinant of Health in Medical Education: A Single Class Session Can Change Privilege Perspective.

    Science.gov (United States)

    Witten, Nash A K; Maskarinec, Gregory G

    2015-09-01

    Accredited medical schools are required to prepare students to recognize the social determinants of health, such as privilege, yet privilege education has been overlooked in medical school curricula. The purpose of this study is to determine whether a single class session on privilege, within a social justice elective offered to first and second year medical students, is sufficient to change the perspective of medical students concerning their own personal privilege. A pre-class survey, followed by a class session on privilege, and post-class survey were conducted. Thirteen of the 18 students enrolled in the elective completed the pre-class survey. Ten students completed the post-class survey, although only 9 completed both the pre- and post-class surveys. The demographic profile of the participants was 93% Asian and 7% White ethnicity, with 57% identifying as being culturally American. There was no significant difference between average male and female or between age groups' self-assessed privilege amounts. For all characteristics tested, except hair color, participants had an increased self-assessed privilege perspective following the class. Three participants had an overall positive difference in privilege perspective, three participants had an overall negative difference in privilege perspective, and three participants had only a minimal change in privilege perspective. The absolute total difference in privilege perspective was 25 units of change. The single class session on privilege was sufficient to change significantly the perspective of medical students on their own personal privilege; however, future studies with larger groups of medical students are needed to elucidate other findings suggested by this study.

  8. Satellite markers: a simple method for ground truth car pose on stereo video

    Science.gov (United States)

    Gil, Gustavo; Savino, Giovanni; Piantini, Simone; Pierini, Marco

    2018-04-01

    Artificial prediction of future location of other cars in the context of advanced safety systems is a must. The remote estimation of car pose and particularly its heading angle is key to predict its future location. Stereo vision systems allow to get the 3D information of a scene. Ground truth in this specific context is associated with referential information about the depth, shape and orientation of the objects present in the traffic scene. Creating 3D ground truth is a measurement and data fusion task associated with the combination of different kinds of sensors. The novelty of this paper is the method to generate ground truth car pose only from video data. When the method is applied to stereo video, it also provides the extrinsic camera parameters for each camera at frame level which are key to quantify the performance of a stereo vision system when it is moving because the system is subjected to undesired vibrations and/or leaning. We developed a video post-processing technique which employs a common camera calibration tool for the 3D ground truth generation. In our case study, we focus in accurate car heading angle estimation of a moving car under realistic imagery. As outcomes, our satellite marker method provides accurate car pose at frame level, and the instantaneous spatial orientation for each camera at frame level.

  9. A note on the conditional density estimate in single functional index model

    OpenAIRE

    2010-01-01

    Abstract In this paper, we consider estimation of the conditional density of a scalar response variable Y given a Hilbertian random variable X when the observations are linked with a single-index structure. We establish the pointwise and the uniform almost complete convergence (with the rate) of the kernel estimate of this model. As an application, we show how our result can be applied in the prediction problem via the conditional mode estimate. Finally, the estimation of the funct...

  10. Students’ Creativity: Problem Posing in Structured Situation

    Science.gov (United States)

    Amalina, I. K.; Amirudin, M.; Budiarto, M. T.

    2018-01-01

    This is a qualitative research concerning on students’ creativity on problem posing task. The study aimed at describing the students’ creative thinking ability to pose the mathematics problem in structured situations with varied condition of given problems. In order to find out the students’ creative thinking ability, an analysis of mathematics problem posing test based on fluency, novelty, and flexibility and interview was applied for categorizing students’ responses on that task. The data analysis used the quality of problem posing and categorized in 4 level of creativity. The results revealed from 29 secondary students grade 8, a student in CTL (Creative Thinking Level) 1 met the fluency. A student in CTL 2 met the novelty, while a student in CTL 3 met both fluency and novelty and no one in CTL 4. These results are affected by students’ mathematical experience. The findings of this study highlight that student’s problem posing creativity are dependent on their experience in mathematics learning and from the point of view of which students start to pose problem.

  11. Multiparameter estimation with single photons—linearly-optically generated quantum entanglement beats the shotnoise limit

    Science.gov (United States)

    You, Chenglong; Adhikari, Sushovit; Chi, Yuxi; LaBorde, Margarite L.; Matyas, Corey T.; Zhang, Chenyu; Su, Zuen; Byrnes, Tim; Lu, Chaoyang; Dowling, Jonathan P.; Olson, Jonathan P.

    2017-12-01

    It was suggested in (Motes et al 2015 Phys. Rev. Lett. 114 170802) that optical networks with relatively inexpensive overheads—single photon Fock states, passive optical elements, and single photon detection—can show significant improvements over classical strategies for single-parameter estimation, when the number of modes in the network is small (ncompute the quantum Cramér-Rao bound to show these networks can have a constant-factor quantum advantage in multi-parameter estimation for even large number of modes. Additionally, we provide a simplified measurement scheme using only single-photon (on-off) detectors that is capable of approximately obtaining this sensitivity for a small number of modes.

  12. Current Source Density Estimation for Single Neurons

    Directory of Open Access Journals (Sweden)

    Dorottya Cserpán

    2014-03-01

    Full Text Available Recent developments of multielectrode technology made it possible to measure the extracellular potential generated in the neural tissue with spatial precision on the order of tens of micrometers and on submillisecond time scale. Combining such measurements with imaging of single neurons within the studied tissue opens up new experimental possibilities for estimating distribution of current sources along a dendritic tree. In this work we show that if we are able to relate part of the recording of extracellular potential to a specific cell of known morphology we can estimate the spatiotemporal distribution of transmembrane currents along it. We present here an extension of the kernel CSD method (Potworowski et al., 2012 applicable in such case. We test it on several model neurons of progressively complicated morphologies from ball-and-stick to realistic, up to analysis of simulated neuron activity embedded in a substantial working network (Traub et al, 2005. We discuss the caveats and possibilities of this new approach.

  13. Improvement of Source Number Estimation Method for Single Channel Signal.

    Directory of Open Access Journals (Sweden)

    Zhi Dong

    Full Text Available Source number estimation methods for single channel signal have been investigated and the improvements for each method are suggested in this work. Firstly, the single channel data is converted to multi-channel form by delay process. Then, algorithms used in the array signal processing, such as Gerschgorin's disk estimation (GDE and minimum description length (MDL, are introduced to estimate the source number of the received signal. The previous results have shown that the MDL based on information theoretic criteria (ITC obtains a superior performance than GDE at low SNR. However it has no ability to handle the signals containing colored noise. On the contrary, the GDE method can eliminate the influence of colored noise. Nevertheless, its performance at low SNR is not satisfactory. In order to solve these problems and contradictions, the work makes remarkable improvements on these two methods on account of the above consideration. A diagonal loading technique is employed to ameliorate the MDL method and a jackknife technique is referenced to optimize the data covariance matrix in order to improve the performance of the GDE method. The results of simulation have illustrated that the performance of original methods have been promoted largely.

  14. GAGG:ce single crystalline films: New perspective scintillators for electron detection in SEM

    International Nuclear Information System (INIS)

    Bok, Jan; Lalinský, Ondřej; Hanuš, Martin; Onderišinová, Zuzana; Kelar, Jakub; Kučera, Miroslav

    2016-01-01

    Single crystal scintillators are frequently used for electron detection in scanning electron microscopy (SEM). We report gadolinium aluminum gallium garnet (GAGG:Ce) single crystalline films as a new perspective scintillators for the SEM. For the first time, the epitaxial garnet films were used in a practical application: the GAGG:Ce scintillator was incorporated into a SEM scintillation electron detector and it showed improved image quality. In order to prove the GAGG:Ce quality accurately, the scintillation properties were examined using electron beam excitation and compared with frequently used scintillators in the SEM. The results demonstrate excellent emission efficiency of the GAGG:Ce single crystalline films together with their very fast scintillation decay useful for demanding SEM applications. - Highlights: • First practical application of epitaxial garnet films demonstrated in SEM. • Improved image quality of SEM equipped with GAGG:Ce single crystalline thin film scintillator. • Scintillation properties of GAGG:Ce films compared with standard bulk crystal scintillators.

  15. Single-cell entropy for accurate estimation of differentiation potency from a cell's transcriptome

    Science.gov (United States)

    Teschendorff, Andrew E.; Enver, Tariq

    2017-01-01

    The ability to quantify differentiation potential of single cells is a task of critical importance. Here we demonstrate, using over 7,000 single-cell RNA-Seq profiles, that differentiation potency of a single cell can be approximated by computing the signalling promiscuity, or entropy, of a cell's transcriptome in the context of an interaction network, without the need for feature selection. We show that signalling entropy provides a more accurate and robust potency estimate than other entropy-based measures, driven in part by a subtle positive correlation between the transcriptome and connectome. Signalling entropy identifies known cell subpopulations of varying potency and drug resistant cancer stem-cell phenotypes, including those derived from circulating tumour cells. It further reveals that expression heterogeneity within single-cell populations is regulated. In summary, signalling entropy allows in silico estimation of the differentiation potency and plasticity of single cells and bulk samples, providing a means to identify normal and cancer stem-cell phenotypes. PMID:28569836

  16. Estimation of perspective errors in 2D2C-PIV measurements for 3D concentrated vortices

    Science.gov (United States)

    Ma, Bao-Feng; Jiang, Hong-Gang

    2018-06-01

    Two-dimensional planar PIV (2D2C) is still extensively employed in flow measurement owing to its availability and reliability, although more advanced PIVs have been developed. It has long been recognized that there exist perspective errors in velocity fields when employing the 2D2C PIV to measure three-dimensional (3D) flows, the magnitude of which depends on out-of-plane velocity and geometric layouts of the PIV. For a variety of vortex flows, however, the results are commonly represented by vorticity fields, instead of velocity fields. The present study indicates that the perspective error in vorticity fields relies on gradients of the out-of-plane velocity along a measurement plane, instead of the out-of-plane velocity itself. More importantly, an estimation approach to the perspective error in 3D vortex measurements was proposed based on a theoretical vortex model and an analysis on physical characteristics of the vortices, in which the gradient of out-of-plane velocity is uniquely determined by the ratio of the maximum out-of-plane velocity to maximum swirling velocity of the vortex; meanwhile, the ratio has upper limits for naturally formed vortices. Therefore, if the ratio is imposed with the upper limits, the perspective error will only rely on the geometric layouts of PIV that are known in practical measurements. Using this approach, the upper limits of perspective errors of a concentrated vortex can be estimated for vorticity and other characteristic quantities of the vortex. In addition, the study indicates that the perspective errors in vortex location, vortex strength, and vortex radius can be all zero for axisymmetric vortices if they are calculated by proper methods. The dynamic mode decomposition on an oscillatory vortex indicates that the perspective errors of each DMD mode are also only dependent on the gradient of out-of-plane velocity if the modes are represented by vorticity.

  17. Estimating envelope thermal characteristics from single point in time thermal images

    Science.gov (United States)

    Alshatshati, Salahaldin Faraj

    Energy efficiency programs implemented nationally in the U.S. by utilities have rendered savings which have cost on average 0.03/kWh. This cost is still well below generation costs. However, as the lowest cost energy efficiency measures are adopted, this the cost effectiveness of further investment declines. Thus there is a need to more effectively find the most opportunities for savings regionally and nationally, so that the greatest cost effectiveness in implementing energy efficiency can be achieved. Integral to this process. are at scale energy audits. However, on-site building energy audits process are expensive, in the range of US1.29/m2-$5.37/m2 and there are an insufficient number of professionals to perform the audits. Energy audits that can be conducted at-scale and at low cost are needed. Research is presented that addresses at community-wide scales characterization of building envelope thermal characteristics via drive-by and fly-over GPS linked thermal imaging. A central question drives this research: Can single point-in-time thermal images be used to infer U-values and thermal capacitances of walls and roofs? Previous efforts to use thermal images to estimate U-values have been limited to rare steady exterior weather conditions. The approaches posed here are based upon the development two models first is a dynamic model of a building envelope component with unknown U-value and thermal capacitance. The weather conditions prior to the thermal image are used as inputs to the model. The model is solved to determine the exterior surface temperature, ultimately predicted the temperature at the thermal measurement time. The model U-value and thermal capacitance are tuned in order to force the error between the predicted surface temperature and the measured surface temperature from thermal imaging to be near zero. This model is developed simply to show that such a model cannot be relied upon to accurately estimate the U-value. The second is a data

  18. Assessing exposure risks for aquatic organisms posed by Tamiflu use under seasonal influenza and pandemic conditions

    International Nuclear Information System (INIS)

    Chen, Wei-Yu; Lin, Chia-Jung; Liao, Chung-Min

    2014-01-01

    Environmental pollution by anti-influenza drugs is increasingly recognized as a threat to aquatic environments. However, little is known about empirical data on risk effects posed by environmentally relevant concentrations of anti-influenza drug based on recently published ecotoxicological researches in Taiwan. Here we linked ecotoxicology models with an epidemiological scheme to assess exposure risks of aquatic organisms and environmental hazards posed by antiviral oseltamivir (Tamiflu) use in Taiwan. Built on published bioassays, we used probabilistic risk assessment model to estimate potential threats of environmentally relevant hazards on algae, daphnid, and zerbrafish. We found that Tamiflu use was unlikely to pose a significant chronic environmental risk to daphnia and zebrafish during seasonal influenza. However, the chronic environmental risk posed by Tamiflu use during pandemic was alarming. We conclude that no significant risk to algal growth was found during seasonal influenza and high pandemic Tamiflu use. -- Highlights: • Environmentally relevant concentrations of anti-influenza drug have ecotoxicologically important effects. • Tamiflu is unlikely to pose a significant chronic environmental risk during seasonal influenza. • Chronic environmental risk posed by Tamiflu during pandemic is alarming. • Tertiary process in sewage treatment plants is crucial in mitigating Tamiflu exposure risk. -- A probabilistic framework can be used for assessing exposure risks posed by environmentally relevant concentrations of anti-influenza drug in aquatic ecosystems

  19. Single-Trial Evoked Potential Estimating Based on Sparse Coding under Impulsive Noise Environment

    Directory of Open Access Journals (Sweden)

    Nannan Yu

    2018-01-01

    Full Text Available Estimating single-trial evoked potentials (EPs corrupted by the spontaneous electroencephalogram (EEG can be regarded as signal denoising problem. Sparse coding has significant success in signal denoising and EPs have been proven to have strong sparsity over an appropriate dictionary. In sparse coding, the noise generally is considered to be a Gaussian random process. However, some studies have shown that the background noise in EPs may present an impulsive characteristic which is far from Gaussian but suitable to be modeled by the α-stable distribution 1<α≤2. Consequently, the performances of general sparse coding will degrade or even fail. In view of this, we present a new sparse coding algorithm using p-norm optimization in single-trial EPs estimating. The algorithm can track the underlying EPs corrupted by α-stable distribution noise, trial-by-trial, without the need to estimate the α value. Simulations and experiments on human visual evoked potentials and event-related potentials are carried out to examine the performance of the proposed approach. Experimental results show that the proposed method is effective in estimating single-trial EPs under impulsive noise environment.

  20. Numerical methods for the design of large-scale nonlinear discrete ill-posed inverse problems

    International Nuclear Information System (INIS)

    Haber, E; Horesh, L; Tenorio, L

    2010-01-01

    Design of experiments for discrete ill-posed problems is a relatively new area of research. While there has been some limited work concerning the linear case, little has been done to study design criteria and numerical methods for ill-posed nonlinear problems. We present an algorithmic framework for nonlinear experimental design with an efficient numerical implementation. The data are modeled as indirect, noisy observations of the model collected via a set of plausible experiments. An inversion estimate based on these data is obtained by a weighted Tikhonov regularization whose weights control the contribution of the different experiments to the data misfit term. These weights are selected by minimization of an empirical estimate of the Bayes risk that is penalized to promote sparsity. This formulation entails a bilevel optimization problem that is solved using a simple descent method. We demonstrate the viability of our design with a problem in electromagnetic imaging based on direct current resistivity and magnetotelluric data

  1. Pose Planning for the Feed Support System of FAST

    Directory of Open Access Journals (Sweden)

    Rui Yao

    2014-01-01

    Full Text Available A six-cable driven parallel manipulator and an A-B rotator in the feed support system of the Five-hundred-meter Aperture Spherical radio Telescope (FAST are adopted for realizing the position and pose of nine feeds. The six-cable driven parallel manipulator is a flexible mechanism, which may not be stably controlled due to a small cable tension. The A-B rotator is a rigid mechanism, and its stability and accuracy can be improved by small pose angle. Based on the different characteristics, a pose planning function is presented. The optimization target of the pose planning function is to get the smallest pose angle of the A-B rotator, and the constraint condition can reflect the controllability of the six-cable driven parallel manipulator. Then, the pose planning realization process of the feed support system is proposed. Based on the pose planning method, optimized pose angles of the feed support system for the nine feeds are obtained, which suggests that the pose angle of the six-cable driven parallel manipulator changes from 0° to 14° and the pose angle of the A-B rotator changes from 0° to 26.4°.

  2. 2D Methods for pose invariant face recognition

    CSIR Research Space (South Africa)

    Mokoena, Ntabiseng

    2016-12-01

    Full Text Available The ability to recognise face images under random pose is a task that is done effortlessly by human beings. However, for a computer system, recognising face images under varying poses still remains an open research area. Face recognition across pose...

  3. The nucleolus is well-posed

    Science.gov (United States)

    Fragnelli, Vito; Patrone, Fioravante; Torre, Anna

    2006-02-01

    The lexicographic order is not representable by a real-valued function, contrary to many other orders or preorders. So, standard tools and results for well-posed minimum problems cannot be used. We prove that under suitable hypotheses it is however possible to guarantee the well-posedness of a lexicographic minimum over a compact or convex set. This result allows us to prove that some game theoretical solution concepts, based on lexicographic order are well-posed: in particular, this is true for the nucleolus.

  4. Solving ill-posed control problems by stabilized finite element methods: an alternative to Tikhonov regularization

    Science.gov (United States)

    Burman, Erik; Hansbo, Peter; Larson, Mats G.

    2018-03-01

    Tikhonov regularization is one of the most commonly used methods for the regularization of ill-posed problems. In the setting of finite element solutions of elliptic partial differential control problems, Tikhonov regularization amounts to adding suitably weighted least squares terms of the control variable, or derivatives thereof, to the Lagrangian determining the optimality system. In this note we show that the stabilization methods for discretely ill-posed problems developed in the setting of convection-dominated convection-diffusion problems, can be highly suitable for stabilizing optimal control problems, and that Tikhonov regularization will lead to less accurate discrete solutions. We consider some inverse problems for Poisson’s equation as an illustration and derive new error estimates both for the reconstruction of the solution from the measured data and reconstruction of the source term from the measured data. These estimates include both the effect of the discretization error and error in the measurements.

  5. Open-Lake Experimental Investigation of Azimuth Angle Estimation Using a Single Acoustic Vector Sensor

    Directory of Open Access Journals (Sweden)

    Anbang Zhao

    2018-01-01

    Full Text Available Five well-known azimuth angle estimation methods using a single acoustic vector sensor (AVS are investigated in open-lake experiments. A single AVS can measure both the acoustic pressure and acoustic particle velocity at a signal point in space and output multichannel signals. The azimuth angle of one source can be estimated by using a single AVS in a passive sonar system. Open-lake experiments are carried out to evaluate how these different techniques perform in estimating azimuth angle of a source. The AVS that was applied in these open-lake experiments is a two-dimensional accelerometer structure sensor. It consists of two identical uniaxial velocity sensors in orthogonal orientations, plus a pressure sensor—all in spatial collocation. These experimental results indicate that all these methods can effectively realize the azimuth angle estimation using only one AVS. The results presented in this paper reveal that AVS can be applied in a wider range of application in distributed underwater acoustic systems for passive detection, localization, classification, and so on.

  6. Multi-person localization and orientation estimation in volumetric scene reconstructions

    NARCIS (Netherlands)

    Liem, M.C.

    2014-01-01

    Accurate localization of persons and estimation of their pose are important topics in current-day computer vision research. As part of the pose estimation, estimating the body orientation of a person (i.e. rotation around torso major axis) conveys important information about the person's current

  7. In-the-wild facial expression recognition in extreme poses

    Science.gov (United States)

    Yang, Fei; Zhang, Qian; Zheng, Chi; Qiu, Guoping

    2018-04-01

    In the computer research area, facial expression recognition is a hot research problem. Recent years, the research has moved from the lab environment to in-the-wild circumstances. It is challenging, especially under extreme poses. But current expression detection systems are trying to avoid the pose effects and gain the general applicable ability. In this work, we solve the problem in the opposite approach. We consider the head poses and detect the expressions within special head poses. Our work includes two parts: detect the head pose and group it into one pre-defined head pose class; do facial expression recognize within each pose class. Our experiments show that the recognition results with pose class grouping are much better than that of direct recognition without considering poses. We combine the hand-crafted features, SIFT, LBP and geometric feature, with deep learning feature as the representation of the expressions. The handcrafted features are added into the deep learning framework along with the high level deep learning features. As a comparison, we implement SVM and random forest to as the prediction models. To train and test our methodology, we labeled the face dataset with 6 basic expressions.

  8. Quantifying cannabis: A field study of marijuana quantity estimation.

    Science.gov (United States)

    Prince, Mark A; Conner, Bradley T; Pearson, Matthew R

    2018-05-17

    The assessment of marijuana use quantity poses unique challenges. These challenges have limited research efforts on quantity assessments. However, quantity estimates are critical to detecting associations between marijuana use and outcomes. We examined accuracy of marijuana users' estimations of quantities of marijuana they prepared to ingest and predictors of both how much was prepared for a single dose and the degree of (in)accuracy of participants' estimates. We recruited a sample of 128 regular-to-heavy marijuana users for a field study wherein they prepared and estimated quantities of marijuana flower in a joint or a bowl as well as marijuana concentrate using a dab tool. The vast majority of participants overestimated the quantity of marijuana that they used in their preparations. We failed to find robust predictors of estimation accuracy. Self-reported quantity estimates are inaccurate, which has implications for studying the link between quantity and marijuana use outcomes. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  9. Skill Levels of Prospective Physics Teachers on Problem Posing

    Science.gov (United States)

    Cildir, Sema; Sezen, Nazan

    2011-01-01

    Problem posing is one of the topics which the educators thoroughly accentuate. Problem posing skill is defined as an introvert activity of a student's learning. In this study, skill levels of prospective physics teachers on problem posing were determined and their views on problem posing were evaluated. To this end, prospective teachers were given…

  10. Perspectives on health.

    Science.gov (United States)

    Huch, M H

    1991-01-01

    On May 12, 1989, in Pittsburgh, six nurse leaders participated in a panel discussion on health at Discovery International, Inc.'s Nurse Theorist Conference. The participants were Imogene King, Nola Pender, Betty Neuman, Martha E. Rogers, Afaf Meleis and Rosemarie Rizzo Parse. The goal of the conferences was to present views on the meaning of health from different perspectives. The panel discussion provided the nurse leaders with an opportunity to engage in a dialogue about health. Five of the participants answered the questions posed and the conference keynote speaker Afaf Meleis responded. Four questions were posed to the panel relating to the meaning of health, the uniqueness of nursing, and nurse-person relationships. The dialogue of the panel discussion follows.

  11. A Layered Approach for Robust Spatial Virtual Human Pose Reconstruction Using a Still Image

    Directory of Open Access Journals (Sweden)

    Chengyu Guo

    2016-02-01

    Full Text Available Pedestrian detection and human pose estimation are instructive for reconstructing a three-dimensional scenario and for robot navigation, particularly when large amounts of vision data are captured using various data-recording techniques. Using an unrestricted capture scheme, which produces occlusions or breezing, the information describing each part of a human body and the relationship between each part or even different pedestrians must be present in a still image. Using this framework, a multi-layered, spatial, virtual, human pose reconstruction framework is presented in this study to recover any deficient information in planar images. In this framework, a hierarchical parts-based deep model is used to detect body parts by using the available restricted information in a still image and is then combined with spatial Markov random fields to re-estimate the accurate joint positions in the deep network. Then, the planar estimation results are mapped onto a virtual three-dimensional space using multiple constraints to recover any deficient spatial information. The proposed approach can be viewed as a general pre-processing method to guide the generation of continuous, three-dimensional motion data. The experiment results of this study are used to describe the effectiveness and usability of the proposed approach.

  12. Implications of a consumer-based perspective for the estimation of GHG emissions. The illustrative case of Luxembourg

    International Nuclear Information System (INIS)

    Caro, Dario; Rugani, Benedetto; Pulselli, Federico Maria; Benetto, Enrico

    2015-01-01

    The Kyoto protocol has established an accounting system for national greenhouse gas (GHG) emissions according to a geographic criterion (producer perspective), such as that proposed by the IPCC guidelines for national GHG inventories. However, the representativeness of this approach is still being debated, because the role of final consumers (consumer perspective) is not considered in the emission allocation system. This paper explores the usefulness of a hybrid analysis, including input–output (IO) and process inventory data, as a complementary tool for estimating and allocating national GHG emissions according to both consumer- and producer-based perspectives. We assess the historical GHG impact profile (from 1995 to 2009) of Luxembourg, which is taken as a case study. The country's net consumption over time is estimated to generate about 28,700 Gg CO 2 e/year on average. Compared to the conventional IPCC inventory, the IO-based framework typically shows much higher emission estimations. This relevant discrepancy is mainly due to the different points of view obtained from the hybrid model, in particular with regard to the contribution of imported goods and services. Detailing the GHG inventory by economic activity and considering a wider system boundary make the hybrid IO method advantageous as compared to the IPCC approach, but its effective implementation is still limited by the relatively complex modeling system, as well as the lack of coordination and scarce availability of datasets at the national level. - Highlights: • GHG emissions for Luxembourg are assessed using hybrid input–output (IO) modeling. • Consumer and producer perspectives are compared for the period 1995–2009. • IO-based GHG profiles are remarkably higher than traditional IPCC inventorying. • IO-based GHG accounting presents some advantages but is limited in implementation. • Key-aspects of IPCC and IO-based methods are extensively investigated and compared

  13. Implications of a consumer-based perspective for the estimation of GHG emissions. The illustrative case of Luxembourg

    Energy Technology Data Exchange (ETDEWEB)

    Caro, Dario, E-mail: caro2@unisi.it [Ecodynamics Group/DEEPS, Department of Environment, Earth and Physical Sciences, University of Siena, Via A. Moro, 2, I-53100 Siena (Italy); Department of Animal Science, University of California, Davis, CA 95616 (United States); Rugani, Benedetto [Public Research Centre Henri Tudor (CRPHT), Resource Centre for Environmental Technologies (CRTE), 6A, avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette (Luxembourg); Pulselli, Federico Maria [Ecodynamics Group/DEEPS, Department of Environment, Earth and Physical Sciences, University of Siena, Via A. Moro, 2, I-53100 Siena (Italy); Benetto, Enrico [Public Research Centre Henri Tudor (CRPHT), Resource Centre for Environmental Technologies (CRTE), 6A, avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette (Luxembourg)

    2015-03-01

    The Kyoto protocol has established an accounting system for national greenhouse gas (GHG) emissions according to a geographic criterion (producer perspective), such as that proposed by the IPCC guidelines for national GHG inventories. However, the representativeness of this approach is still being debated, because the role of final consumers (consumer perspective) is not considered in the emission allocation system. This paper explores the usefulness of a hybrid analysis, including input–output (IO) and process inventory data, as a complementary tool for estimating and allocating national GHG emissions according to both consumer- and producer-based perspectives. We assess the historical GHG impact profile (from 1995 to 2009) of Luxembourg, which is taken as a case study. The country's net consumption over time is estimated to generate about 28,700 Gg CO{sub 2}e/year on average. Compared to the conventional IPCC inventory, the IO-based framework typically shows much higher emission estimations. This relevant discrepancy is mainly due to the different points of view obtained from the hybrid model, in particular with regard to the contribution of imported goods and services. Detailing the GHG inventory by economic activity and considering a wider system boundary make the hybrid IO method advantageous as compared to the IPCC approach, but its effective implementation is still limited by the relatively complex modeling system, as well as the lack of coordination and scarce availability of datasets at the national level. - Highlights: • GHG emissions for Luxembourg are assessed using hybrid input–output (IO) modeling. • Consumer and producer perspectives are compared for the period 1995–2009. • IO-based GHG profiles are remarkably higher than traditional IPCC inventorying. • IO-based GHG accounting presents some advantages but is limited in implementation. • Key-aspects of IPCC and IO-based methods are extensively investigated and compared.

  14. Single event upset threshold estimation based on local laser irradiation

    International Nuclear Information System (INIS)

    Chumakov, A.I.; Egorov, A.N.; Mavritsky, O.B.; Yanenko, A.V.

    1999-01-01

    An approach for estimation of ion-induced SEU threshold based on local laser irradiation is presented. Comparative experiment and software simulation research were performed at various pulse duration and spot size. Correlation of single event threshold LET to upset threshold laser energy under local irradiation was found. The computer analysis of local laser irradiation of IC structures was developed for SEU threshold LET estimation. The correlation of local laser threshold energy with SEU threshold LET was shown. Two estimation techniques were suggested. The first one is based on the determination of local laser threshold dose taking into account the relation of sensitive area to local irradiated area. The second technique uses the photocurrent peak value instead of this relation. The agreement between the predicted and experimental results demonstrates the applicability of this approach. (authors)

  15. Local Feature Learning for Face Recognition under Varying Poses

    DEFF Research Database (Denmark)

    Duan, Xiaodong; Tan, Zheng-Hua

    2015-01-01

    In this paper, we present a local feature learning method for face recognition to deal with varying poses. As opposed to the commonly used approaches of recovering frontal face images from profile views, the proposed method extracts the subject related part from a local feature by removing the pose...... related part in it on the basis of a pose feature. The method has a closed-form solution, hence being time efficient. For performance evaluation, cross pose face recognition experiments are conducted on two public face recognition databases FERET and FEI. The proposed method shows a significant...... recognition improvement under varying poses over general local feature approaches and outperforms or is comparable with related state-of-the-art pose invariant face recognition approaches. Copyright ©2015 by IEEE....

  16. To Strike a Pose: No Stereotype Backlash for Power Posing Women

    Directory of Open Access Journals (Sweden)

    Miriam Rennung

    2016-09-01

    Full Text Available Power posing, the adoption of open and powerful postures, has effects that parallel those of actual social power. This study explored the social evaluation of adopting powerful versus powerless body postures in men and women regarding perceived warmth, competence, and the likelihood of eliciting admiration, envy, pity, and contempt. Previous findings suggest that the display of power by women may have side effects due to gender stereotyping, namely reduced warmth ratings and negative emotional reactions. An experiment (N = 2,473 asked participants to rate pictures of men and women who adopted high-power or low-power body postures. High-power posers were rated higher on competence, admiration, envy, and contempt compared to low-power posers, whereas the opposite was true for pity. There was no impact of power posing on perceived warmth. Contrary to expectations, the poser’s gender did not moderate any of the effects. These findings suggest that nonverbal displays of power do influence fundamental dimensions of social perception and their accompanying emotional reactions but result in comparably positive and negative evaluations for both genders.

  17. Best-basis estimates of solubility of selected radionuclides in sludges in Hanford single-shell tanks

    International Nuclear Information System (INIS)

    HARMSEN, R.W.

    1999-01-01

    The Hanford Defined Waste (HDW) model (Rev. 4) (Agnew et al. 1997) projects inventories (as of January 1, 1994) of 46 radionuclides in the Hanford Site underground waste storage tanks. To model the distribution of the 46 radionuclides among the 177 tanks, it was necessary for Agnew et al. to estimate the solubility of each radionuclide in the various waste types originally added to the single-shell tanks. Previous editions of the HDW model used single-point solubility estimates. The work described in this report was undertaken to provide more accurate estimates of the solubility of all 46 radionuclides in the various wastes

  18. Best-basis estimates of solubility of selected radionuclides in sludges in Hanford single-shell tanks

    Energy Technology Data Exchange (ETDEWEB)

    HARMSEN, R.W.

    1999-02-24

    The Hanford Defined Waste (HDW) model (Rev. 4) (Agnew et al. 1997) projects inventories (as of January 1, 1994) of 46 radionuclides in the Hanford Site underground waste storage tanks. To model the distribution of the 46 radionuclides among the 177 tanks, it was necessary for Agnew et al. to estimate the solubility of each radionuclide in the various waste types originally added to the single-shell tanks. Previous editions of the HDW model used single-point solubility estimates. The work described in this report was undertaken to provide more accurate estimates of the solubility of all 46 radionuclides in the various wastes.

  19. A new framework for estimating return levels using regional frequency analysis

    Science.gov (United States)

    Winter, Hugo; Bernardara, Pietro; Clegg, Georgina

    2017-04-01

    We propose a new framework for incorporating more spatial and temporal information into the estimation of extreme return levels. Currently, most studies use extreme value models applied to data from a single site; an approach which is inefficient statistically and leads to return level estimates that are less physically realistic. We aim to highlight the benefits that could be obtained by using methodology based upon regional frequency analysis as opposed to classic single site extreme value analysis. This motivates a shift in thinking, which permits the evaluation of local and regional effects and makes use of the wide variety of data that are now available on high temporal and spatial resolutions. The recent winter storms over the UK during the winters of 2013-14 and 2015-16, which have caused wide-ranging disruption and damaged important infrastructure, provide the main motivation for the current work. One of the most impactful natural hazards is flooding, which is often initiated by extreme precipitation. In this presentation, we focus on extreme rainfall, but shall discuss other meteorological variables alongside potentially damaging hazard combinations. To understand the risks posed by extreme precipitation, we need reliable statistical models which can be used to estimate quantities such as the T-year return level, i.e. the level which is expected to be exceeded once every T-years. Extreme value theory provides the main collection of statistical models that can be used to estimate the risks posed by extreme precipitation events. Broadly, at a single site, a statistical model is fitted to exceedances of a high threshold and the model is used to extrapolate to levels beyond the range of the observed data. However, when we have data at many sites over a spatial domain, fitting a separate model for each separate site makes little sense and it would be better if we could incorporate all this information to improve the reliability of return level estimates. Here

  20. Method for Estimating Evaporative Potential (IM/CLO) from ASTM Standard Single Wind Velocity Measures

    Science.gov (United States)

    2016-08-10

    IM/CLO) FROM ASTM STANDARD SINGLE WIND VELOCITY MEASURES DISCLAIMER The opinions or assertions contained herein are the private views of the...USARIEM TECHNICAL REPORT T16-14 METHOD FOR ESTIMATING EVAPORATIVE POTENTIAL (IM/CLO) FROM ASTM STANDARD SINGLE WIND VELOCITY... ASTM STANDARD SINGLE WIND VELOCITY MEASURES Adam W. Potter Biophysics and Biomedical Modeling Division U.S. Army Research Institute of Environmental

  1. A self-organizing state-space-model approach for parameter estimation in hodgkin-huxley-type models of single neurons.

    Directory of Open Access Journals (Sweden)

    Dimitrios V Vavoulis

    Full Text Available Traditional approaches to the problem of parameter estimation in biophysical models of neurons and neural networks usually adopt a global search algorithm (for example, an evolutionary algorithm, often in combination with a local search method (such as gradient descent in order to minimize the value of a cost function, which measures the discrepancy between various features of the available experimental data and model output. In this study, we approach the problem of parameter estimation in conductance-based models of single neurons from a different perspective. By adopting a hidden-dynamical-systems formalism, we expressed parameter estimation as an inference problem in these systems, which can then be tackled using a range of well-established statistical inference methods. The particular method we used was Kitagawa's self-organizing state-space model, which was applied on a number of Hodgkin-Huxley-type models using simulated or actual electrophysiological data. We showed that the algorithm can be used to estimate a large number of parameters, including maximal conductances, reversal potentials, kinetics of ionic currents, measurement and intrinsic noise, based on low-dimensional experimental data and sufficiently informative priors in the form of pre-defined constraints imposed on model parameters. The algorithm remained operational even when very noisy experimental data were used. Importantly, by combining the self-organizing state-space model with an adaptive sampling algorithm akin to the Covariance Matrix Adaptation Evolution Strategy, we achieved a significant reduction in the variance of parameter estimates. The algorithm did not require the explicit formulation of a cost function and it was straightforward to apply on compartmental models and multiple data sets. Overall, the proposed methodology is particularly suitable for resolving high-dimensional inference problems based on noisy electrophysiological data and, therefore, a

  2. Penalized linear regression for discrete ill-posed problems: A hybrid least-squares and mean-squared error approach

    KAUST Repository

    Suliman, Mohamed Abdalla Elhag

    2016-12-19

    This paper proposes a new approach to find the regularization parameter for linear least-squares discrete ill-posed problems. In the proposed approach, an artificial perturbation matrix with a bounded norm is forced into the discrete ill-posed model matrix. This perturbation is introduced to enhance the singular-value (SV) structure of the matrix and hence to provide a better solution. The proposed approach is derived to select the regularization parameter in a way that minimizes the mean-squared error (MSE) of the estimator. Numerical results demonstrate that the proposed approach outperforms a set of benchmark methods in most cases when applied to different scenarios of discrete ill-posed problems. Jointly, the proposed approach enjoys the lowest run-time and offers the highest level of robustness amongst all the tested methods.

  3. University Students' Problem Posing Abilities and Attitudes towards Mathematics.

    Science.gov (United States)

    Grundmeier, Todd A.

    2002-01-01

    Explores the problem posing abilities and attitudes towards mathematics of students in a university pre-calculus class and a university mathematical proof class. Reports a significant difference in numeric posing versus non-numeric posing ability in both classes. (Author/MM)

  4. Students’ Mathematical Creative Thinking through Problem Posing Learning

    Science.gov (United States)

    Ulfah, U.; Prabawanto, S.; Jupri, A.

    2017-09-01

    The research aims to investigate the differences in enhancement of students’ mathematical creative thinking ability of those who received problem posing approach assisted by manipulative media and students who received problem posing approach without manipulative media. This study was a quasi experimental research with non-equivalent control group design. Population of this research was third-grade students of a primary school in Bandung city in 2016/2017 academic year. Sample of this research was two classes as experiment class and control class. The instrument used is a test of mathematical creative thinking ability. Based on the results of the research, it is known that the enhancement of the students’ mathematical creative thinking ability of those who received problem posing approach with manipulative media aid is higher than the ability of those who received problem posing approach without manipulative media aid. Students who get learning problem posing learning accustomed in arranging mathematical sentence become matter of story so it can facilitate students to comprehend about story

  5. Manifolds for pose tracking from monocular video

    Science.gov (United States)

    Basu, Saurav; Poulin, Joshua; Acton, Scott T.

    2015-03-01

    We formulate a simple human-pose tracking theory from monocular video based on the fundamental relationship between changes in pose and image motion vectors. We investigate the natural embedding of the low-dimensional body pose space into a high-dimensional space of body configurations that behaves locally in a linear manner. The embedded manifold facilitates the decomposition of the image motion vectors into basis motion vector fields of the tangent space to the manifold. This approach benefits from the style invariance of image motion flow vectors, and experiments to validate the fundamental theory show reasonable accuracy (within 4.9 deg of the ground truth).

  6. The lighter side of advertising: investigating posing and lighting biases.

    Science.gov (United States)

    Thomas, Nicole A; Burkitt, Jennifer A; Patrick, Regan E; Elias, Lorin J

    2008-11-01

    People tend to display the left cheek when posing for a portrait; however, this effect does not appear to generalise to advertising. The amount of body visible in the image and the sex of the poser might also contribute to the posing bias. Portraits also exhibit lateral lighting biases, with most images being lit from the left. This effect might also be present in advertisements. A total of 2801 full-page advertisements were sampled and coded for posing direction, lighting direction, sex of model, and amount of body showing. Images of females showed an overall leftward posing bias, but the biases in males depended on the amount of body visible. Males demonstrated rightward posing biases for head-only images. Overall, images tended to be lit from the top left corner. The two factors of posing and lighting biases appear to influence one another. Leftward-lit images had more leftward poses than rightward, while the opposite occurred for rightward-lit images. Collectively, these results demonstrate that the posing biases in advertisements are dependent on the amount of body showing in the image, and that biases in lighting direction interact with these posing biases.

  7. Novelty Detection for Interactive Pose Recognition by a Social Robot

    Directory of Open Access Journals (Sweden)

    Victor Gonzalez-Pacheco

    2015-04-01

    Full Text Available Active robot learners take an active role in their own learning by making queries to their human teachers when they receive new data. However, not every received input is useful for the robot, and asking for non-informative inputs or asking too many questions might worsen the user's perception of the robot. We present a novelty detection system that enables a robot to ask labels for new stimuli only when they seem both novel and interesting. Our system separates the decision process into two steps: first, it discriminates novel from known stimuli, and second, it estimates if these stimuli are likely to happen again. Our approach uses the notion of curiosity, which controls the eagerness with which the robot asks questions to the user. We evaluate our approach in the domain of pose learning by training our robot with a set of pointing poses able to detect up to 84%, 79%, and 78% of the observed novelties in three different experiments. Our approach enables robots to keep learning continuously, even after training is finished. The introduction of the curiosity parameter allows tuning, for the conditions in which the robot should want to learn more.

  8. Effective dose to staff from interventional procedures: Estimations from single and double dosimetry

    International Nuclear Information System (INIS)

    Kuipers, G.; Velders, X. L.

    2009-01-01

    The exposure of 11 physicians performing interventional procedures was measured by means of two personal dosemeters. One personal dosemeter was worn outside the lead apron and an additional under the lead apron. The study was set up in order to determine the added value of a dosemeter worn under the lead apron. With the doses measured, the effective doses of the physicians were estimated using an algorithm for single dosimetry and two algorithms for double dosimetry. The effective doses calculated with the single dosimetry algorithm ranged from 0.11 to 0.85 mSv in 4 weeks. With the double dosimetry algorithms, the effective doses ranged from 0.02 mSv to 0.47 mSv. The statistical analysis revealed no significant differences in the accuracy of the effective doses calculated with single or double dosimetry algorithms. It was concluded that the effective dose cannot be considered a more accurate estimate when two dosemeters are used instead of one. (authors)

  9. Coupled bias-variance tradeoff for cross-pose face recognition.

    Science.gov (United States)

    Li, Annan; Shan, Shiguang; Gao, Wen

    2012-01-01

    Subspace-based face representation can be looked as a regression problem. From this viewpoint, we first revisited the problem of recognizing faces across pose differences, which is a bottleneck in face recognition. Then, we propose a new approach for cross-pose face recognition using a regressor with a coupled bias-variance tradeoff. We found that striking a coupled balance between bias and variance in regression for different poses could improve the regressor-based cross-pose face representation, i.e., the regressor can be more stable against a pose difference. With the basic idea, ridge regression and lasso regression are explored. Experimental results on CMU PIE, the FERET, and the Multi-PIE face databases show that the proposed bias-variance tradeoff can achieve considerable reinforcement in recognition performance.

  10. Animated pose templates for modeling and detecting human actions.

    Science.gov (United States)

    Yao, Benjamin Z; Nie, Bruce X; Liu, Zicheng; Zhu, Song-Chun

    2014-03-01

    This paper presents animated pose templates (APTs) for detecting short-term, long-term, and contextual actions from cluttered scenes in videos. Each pose template consists of two components: 1) a shape template with deformable parts represented in an And-node whose appearances are represented by the Histogram of Oriented Gradient (HOG) features, and 2) a motion template specifying the motion of the parts by the Histogram of Optical-Flows (HOF) features. A shape template may have more than one motion template represented by an Or-node. Therefore, each action is defined as a mixture (Or-node) of pose templates in an And-Or tree structure. While this pose template is suitable for detecting short-term action snippets in two to five frames, we extend it in two ways: 1) For long-term actions, we animate the pose templates by adding temporal constraints in a Hidden Markov Model (HMM), and 2) for contextual actions, we treat contextual objects as additional parts of the pose templates and add constraints that encode spatial correlations between parts. To train the model, we manually annotate part locations on several keyframes of each video and cluster them into pose templates using EM. This leaves the unknown parameters for our learning algorithm in two groups: 1) latent variables for the unannotated frames including pose-IDs and part locations, 2) model parameters shared by all training samples such as weights for HOG and HOF features, canonical part locations of each pose, coefficients penalizing pose-transition and part-deformation. To learn these parameters, we introduce a semi-supervised structural SVM algorithm that iterates between two steps: 1) learning (updating) model parameters using labeled data by solving a structural SVM optimization, and 2) imputing missing variables (i.e., detecting actions on unlabeled frames) with parameters learned from the previous step and progressively accepting high-score frames as newly labeled examples. This algorithm belongs to a

  11. Estimation of single-year-of-age counts of live births, fetal losses, abortions, and pregnant women for counties of Texas.

    Science.gov (United States)

    Singh, Bismark; Meyers, Lauren Ancel

    2017-05-08

    We provide a methodology for estimating counts of single-year-of-age live-births, fetal-losses, abortions, and pregnant women from aggregated age-group counts. As a case study, we estimate counts for the 254 counties of Texas for the year 2010. We use interpolation to estimate counts of live-births, fetal-losses, and abortions by women of each single-year-of-age for all Texas counties. We then use these counts to estimate the numbers of pregnant women for each single-year-of-age, which were previously available only in aggregate. To support public health policy and planning, we provide single-year-of-age estimates of live-births, fetal-losses, abortions, and pregnant women for all Texas counties in the year 2010, as well as the estimation method source code.

  12. Navigation Aiding by a Hybrid Laser-Camera Motion Estimator for Micro Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Jamal Atman

    2016-09-01

    Full Text Available Micro Air Vehicles (MAVs equipped with various sensors are able to carry out autonomous flights. However, the self-localization of autonomous agents is mostly dependent on Global Navigation Satellite Systems (GNSS. In order to provide an accurate navigation solution in absence of GNSS signals, this article presents a hybrid sensor. The hybrid sensor is a deep integration of a monocular camera and a 2D laser rangefinder so that the motion of the MAV is estimated. This realization is expected to be more flexible in terms of environments compared to laser-scan-matching approaches. The estimated ego-motion is then integrated in the MAV’s navigation system. However, first, the knowledge about the pose between both sensors is obtained by proposing an improved calibration method. For both calibration and ego-motion estimation, 3D-to-2D correspondences are used and the Perspective-3-Point (P3P problem is solved. Moreover, the covariance estimation of the relative motion is presented. The experiments show very accurate calibration and navigation results.

  13. Navigation Aiding by a Hybrid Laser-Camera Motion Estimator for Micro Aerial Vehicles.

    Science.gov (United States)

    Atman, Jamal; Popp, Manuel; Ruppelt, Jan; Trommer, Gert F

    2016-09-16

    Micro Air Vehicles (MAVs) equipped with various sensors are able to carry out autonomous flights. However, the self-localization of autonomous agents is mostly dependent on Global Navigation Satellite Systems (GNSS). In order to provide an accurate navigation solution in absence of GNSS signals, this article presents a hybrid sensor. The hybrid sensor is a deep integration of a monocular camera and a 2D laser rangefinder so that the motion of the MAV is estimated. This realization is expected to be more flexible in terms of environments compared to laser-scan-matching approaches. The estimated ego-motion is then integrated in the MAV's navigation system. However, first, the knowledge about the pose between both sensors is obtained by proposing an improved calibration method. For both calibration and ego-motion estimation, 3D-to-2D correspondences are used and the Perspective-3-Point (P3P) problem is solved. Moreover, the covariance estimation of the relative motion is presented. The experiments show very accurate calibration and navigation results.

  14. Formulas in inverse and ill-posed problems

    CERN Document Server

    Anikonov, Yu E

    1997-01-01

    The Inverse and Ill-Posed Problems Series is a series of monographs publishing postgraduate level information on inverse and ill-posed problems for an international readership of professional scientists and researchers. The series aims to publish works which involve both theory and applications in, e.g., physics, medicine, geophysics, acoustics, electrodynamics, tomography, and ecology.

  15. Estimation of single plane unbalance parameters of a rotor-bearing system using Kalman filtering based force estimation technique

    Science.gov (United States)

    Shrivastava, Akash; Mohanty, A. R.

    2018-03-01

    This paper proposes a model-based method to estimate single plane unbalance parameters (amplitude and phase angle) in a rotor using Kalman filter and recursive least square based input force estimation technique. Kalman filter based input force estimation technique requires state-space model and response measurements. A modified system equivalent reduction expansion process (SEREP) technique is employed to obtain a reduced-order model of the rotor system so that limited response measurements can be used. The method is demonstrated using numerical simulations on a rotor-disk-bearing system. Results are presented for different measurement sets including displacement, velocity, and rotational response. Effects of measurement noise level, filter parameters (process noise covariance and forgetting factor), and modeling error are also presented and it is observed that the unbalance parameter estimation is robust with respect to measurement noise.

  16. The Single Cigarette Economy in India--a Back of the Envelope Survey to Estimate its Magnitude.

    Science.gov (United States)

    Lal, Pranay; Kumar, Ravinder; Ray, Shreelekha; Sharma, Narinder; Bhattarcharya, Bhaktimay; Mishra, Deepak; Sinha, Mukesh K; Christian, Anant; Rathinam, Arul; Singh, Gurbinder

    2015-01-01

    Sale of single cigarettes is an important factor for early experimentation, initiation and persistence of tobacco use and a vital factor in the smoking epidemic in India as it is globally. Single cigarettes also promote the sale of illicit cigarettes and neutralises the effect of pack warnings and effective taxation, making tobacco more accessible and affordable to minors. This is the first study to our knowledge which estimates the size of the single stick market in India. In February 2014, a 10 jurisdiction survey was conducted across India to estimate the sale of cigarettes in packs and sticks, by brands and price over a full business day. We estimate that nearly 75% of all cigarettes are sold as single sticks annually, which translates to nearly half a billion US dollars or 30 percent of the India's excise revenues from all cigarettes. This is the price which the consumers pay but is not captured through tax and therefore pervades into an informal economy. Tracking the retail price of single cigarettes is an efficient way to determine the willingness to pay by cigarette smokers and is a possible method to determine the tax rates in the absence of any other rationale.

  17. Transfer between Pose and Illumination Training in Face Recognition

    Science.gov (United States)

    Liu, Chang Hong; Bhuiyan, Md. Al-Amin; Ward, James; Sui, Jie

    2009-01-01

    The relationship between pose and illumination learning in face recognition was examined in a yes-no recognition paradigm. The authors assessed whether pose training can transfer to a new illumination or vice versa. Results show that an extensive level of pose training through a face-name association task was able to generalize to a new…

  18. Estimation of Single-Crystal Elastic Constants of Polycrystalline Materials from Back-Scattered Grain Noise

    International Nuclear Information System (INIS)

    Haldipur, P.; Margetan, F. J.; Thompson, R. B.

    2006-01-01

    Single-crystal elastic stiffness constants are important input parameters for many calculations in material science. There are well established methods to measure these constants using single-crystal specimens, but such specimens are not always readily available. The ultrasonic properties of metal polycrystals, such as velocity, attenuation, and backscattered grain noise characteristics, depend in part on the single-crystal elastic constants. In this work we consider the estimation of elastic constants from UT measurements and grain-sizing data. We confine ourselves to a class of particularly simple polycrystalline microstructures, found in some jet-engine Nickel alloys, which are single-phase, cubic, equiaxed, and untextured. In past work we described a method to estimate the single-crystal elastic constants from measured ultrasonic velocity and attenuation data accompanied by metallographic analysis of grain size. However, that methodology assumes that all attenuation is due to grain scattering, and thus is not valid if appreciable absorption is present. In this work we describe an alternative approach which uses backscattered grain noise data in place of attenuation data. Efforts to validate the method using a pure copper specimen are discussed, and new results for two jet-engine Nickel alloys are presented

  19. New perspective on single-radiator multiple-port antennas for adaptive beamforming applications.

    Science.gov (United States)

    Byun, Gangil; Choo, Hosung

    2017-01-01

    One of the most challenging problems in recent antenna engineering fields is to achieve highly reliable beamforming capabilities in an extremely restricted space of small handheld devices. In this paper, we introduce a new perspective on single-radiator multiple-port (SRMP) antenna to alter the traditional approach of multiple-antenna arrays for improving beamforming performances with reduced aperture sizes. The major contribution of this paper is to demonstrate the beamforming capability of the SRMP antenna for use as an extremely miniaturized front-end component in more sophisticated beamforming applications. To examine the beamforming capability, the radiation properties and the array factor of the SRMP antenna are theoretically formulated for electromagnetic characterization and are used as complex weights to form adaptive array patterns. Then, its fundamental performance limits are rigorously explored through enumerative studies by varying the dielectric constant of the substrate, and field tests are conducted using a beamforming hardware to confirm the feasibility. The results demonstrate that the new perspective of the SRMP antenna allows for improved beamforming performances with the ability of maintaining consistently smaller aperture sizes compared to the traditional multiple-antenna arrays.

  20. New perspective on single-radiator multiple-port antennas for adaptive beamforming applications.

    Directory of Open Access Journals (Sweden)

    Gangil Byun

    Full Text Available One of the most challenging problems in recent antenna engineering fields is to achieve highly reliable beamforming capabilities in an extremely restricted space of small handheld devices. In this paper, we introduce a new perspective on single-radiator multiple-port (SRMP antenna to alter the traditional approach of multiple-antenna arrays for improving beamforming performances with reduced aperture sizes. The major contribution of this paper is to demonstrate the beamforming capability of the SRMP antenna for use as an extremely miniaturized front-end component in more sophisticated beamforming applications. To examine the beamforming capability, the radiation properties and the array factor of the SRMP antenna are theoretically formulated for electromagnetic characterization and are used as complex weights to form adaptive array patterns. Then, its fundamental performance limits are rigorously explored through enumerative studies by varying the dielectric constant of the substrate, and field tests are conducted using a beamforming hardware to confirm the feasibility. The results demonstrate that the new perspective of the SRMP antenna allows for improved beamforming performances with the ability of maintaining consistently smaller aperture sizes compared to the traditional multiple-antenna arrays.

  1. Composite Estimation for Single-Index Models with Responses Subject to Detection Limits

    KAUST Repository

    Tang, Yanlin; Wang, Huixia Judy; Liang, Hua

    2017-01-01

    We propose a semiparametric estimator for single-index models with censored responses due to detection limits. In the presence of left censoring, the mean function cannot be identified without any parametric distributional assumptions, but the quantile function is still identifiable at upper quantile levels. To avoid parametric distributional assumption, we propose to fit censored quantile regression and combine information across quantile levels to estimate the unknown smooth link function and the index parameter. Under some regularity conditions, we show that the estimated link function achieves the non-parametric optimal convergence rate, and the estimated index parameter is asymptotically normal. The simulation study shows that the proposed estimator is competitive with the omniscient least squares estimator based on the latent uncensored responses for data with normal errors but much more efficient for heavy-tailed data under light and moderate censoring. The practical value of the proposed method is demonstrated through the analysis of a human immunodeficiency virus antibody data set.

  2. Composite Estimation for Single-Index Models with Responses Subject to Detection Limits

    KAUST Repository

    Tang, Yanlin

    2017-11-03

    We propose a semiparametric estimator for single-index models with censored responses due to detection limits. In the presence of left censoring, the mean function cannot be identified without any parametric distributional assumptions, but the quantile function is still identifiable at upper quantile levels. To avoid parametric distributional assumption, we propose to fit censored quantile regression and combine information across quantile levels to estimate the unknown smooth link function and the index parameter. Under some regularity conditions, we show that the estimated link function achieves the non-parametric optimal convergence rate, and the estimated index parameter is asymptotically normal. The simulation study shows that the proposed estimator is competitive with the omniscient least squares estimator based on the latent uncensored responses for data with normal errors but much more efficient for heavy-tailed data under light and moderate censoring. The practical value of the proposed method is demonstrated through the analysis of a human immunodeficiency virus antibody data set.

  3. Non-standard and improperly posed problems

    CERN Document Server

    Straughan, Brian; Ames, William F

    1997-01-01

    Written by two international experts in the field, this book is the first unified survey of the advances made in the last 15 years on key non-standard and improperly posed problems for partial differential equations.This reference for mathematicians, scientists, and engineers provides an overview of the methodology typically used to study improperly posed problems. It focuses on structural stability--the continuous dependence of solutions on the initial conditions and the modeling equations--and on problems for which data are only prescribed on part of the boundary.The book addresses continuou

  4. Method of orthogonally splitting imaging pose measurement

    Science.gov (United States)

    Zhao, Na; Sun, Changku; Wang, Peng; Yang, Qian; Liu, Xintong

    2018-01-01

    In order to meet the aviation's and machinery manufacturing's pose measurement need of high precision, fast speed and wide measurement range, and to resolve the contradiction between measurement range and resolution of vision sensor, this paper proposes an orthogonally splitting imaging pose measurement method. This paper designs and realizes an orthogonally splitting imaging vision sensor and establishes a pose measurement system. The vision sensor consists of one imaging lens, a beam splitter prism, cylindrical lenses and dual linear CCD. Dual linear CCD respectively acquire one dimensional image coordinate data of the target point, and two data can restore the two dimensional image coordinates of the target point. According to the characteristics of imaging system, this paper establishes the nonlinear distortion model to correct distortion. Based on cross ratio invariability, polynomial equation is established and solved by the least square fitting method. After completing distortion correction, this paper establishes the measurement mathematical model of vision sensor, and determines intrinsic parameters to calibrate. An array of feature points for calibration is built by placing a planar target in any different positions for a few times. An terative optimization method is presented to solve the parameters of model. The experimental results show that the field angle is 52 °, the focus distance is 27.40 mm, image resolution is 5185×5117 pixels, displacement measurement error is less than 0.1mm, and rotation angle measurement error is less than 0.15°. The method of orthogonally splitting imaging pose measurement can satisfy the pose measurement requirement of high precision, fast speed and wide measurement range.

  5. Joint Center Estimation Using Single-Frame Optimization: Part 1: Numerical Simulation.

    Science.gov (United States)

    Frick, Eric; Rahmatalla, Salam

    2018-04-04

    The biomechanical models used to refine and stabilize motion capture processes are almost invariably driven by joint center estimates, and any errors in joint center calculation carry over and can be compounded when calculating joint kinematics. Unfortunately, accurate determination of joint centers is a complex task, primarily due to measurements being contaminated by soft-tissue artifact (STA). This paper proposes a novel approach to joint center estimation implemented via sequential application of single-frame optimization (SFO). First, the method minimizes the variance of individual time frames’ joint center estimations via the developed variance minimization method to obtain accurate overall initial conditions. These initial conditions are used to stabilize an optimization-based linearization of human motion that determines a time-varying joint center estimation. In this manner, the complex and nonlinear behavior of human motion contaminated by STA can be captured as a continuous series of unique rigid-body realizations without requiring a complex analytical model to describe the behavior of STA. This article intends to offer proof of concept, and the presented method must be further developed before it can be reasonably applied to human motion. Numerical simulations were introduced to verify and substantiate the efficacy of the proposed methodology. When directly compared with a state-of-the-art inertial method, SFO reduced the error due to soft-tissue artifact in all cases by more than 45%. Instead of producing a single vector value to describe the joint center location during a motion capture trial as existing methods often do, the proposed method produced time-varying solutions that were highly correlated ( r > 0.82) with the true, time-varying joint center solution.

  6. Joint Center Estimation Using Single-Frame Optimization: Part 1: Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Eric Frick

    2018-04-01

    Full Text Available The biomechanical models used to refine and stabilize motion capture processes are almost invariably driven by joint center estimates, and any errors in joint center calculation carry over and can be compounded when calculating joint kinematics. Unfortunately, accurate determination of joint centers is a complex task, primarily due to measurements being contaminated by soft-tissue artifact (STA. This paper proposes a novel approach to joint center estimation implemented via sequential application of single-frame optimization (SFO. First, the method minimizes the variance of individual time frames’ joint center estimations via the developed variance minimization method to obtain accurate overall initial conditions. These initial conditions are used to stabilize an optimization-based linearization of human motion that determines a time-varying joint center estimation. In this manner, the complex and nonlinear behavior of human motion contaminated by STA can be captured as a continuous series of unique rigid-body realizations without requiring a complex analytical model to describe the behavior of STA. This article intends to offer proof of concept, and the presented method must be further developed before it can be reasonably applied to human motion. Numerical simulations were introduced to verify and substantiate the efficacy of the proposed methodology. When directly compared with a state-of-the-art inertial method, SFO reduced the error due to soft-tissue artifact in all cases by more than 45%. Instead of producing a single vector value to describe the joint center location during a motion capture trial as existing methods often do, the proposed method produced time-varying solutions that were highly correlated (r > 0.82 with the true, time-varying joint center solution.

  7. Metal surface corrosion grade estimation from single image

    Science.gov (United States)

    Chen, Yijun; Qi, Lin; Sun, Huyuan; Fan, Hao; Dong, Junyu

    2018-04-01

    Metal corrosion can cause many problems, how to quickly and effectively assess the grade of metal corrosion and timely remediation is a very important issue. Typically, this is done by trained surveyors at great cost. Assisting them in the inspection process by computer vision and artificial intelligence would decrease the inspection cost. In this paper, we propose a dataset of metal surface correction used for computer vision detection and present a comparison between standard computer vision techniques by using OpenCV and deep learning method for automatic metal surface corrosion grade estimation from single image on this dataset. The test has been performed by classifying images and calculating the accuracy for the two different approaches.

  8. Lavrentiev regularization method for nonlinear ill-posed problems

    International Nuclear Information System (INIS)

    Kinh, Nguyen Van

    2002-10-01

    In this paper we shall be concerned with Lavientiev regularization method to reconstruct solutions x 0 of non ill-posed problems F(x)=y o , where instead of y 0 noisy data y δ is an element of X with absolut(y δ -y 0 ) ≤ δ are given and F:X→X is an accretive nonlinear operator from a real reflexive Banach space X into itself. In this regularization method solutions x α δ are obtained by solving the singularly perturbed nonlinear operator equation F(x)+α(x-x*)=y δ with some initial guess x*. Assuming certain conditions concerning the operator F and the smoothness of the element x*-x 0 we derive stability estimates which show that the accuracy of the regularized solutions is order optimal provided that the regularization parameter α has been chosen properly. (author)

  9. Gradient-based stochastic estimation of the density matrix

    Science.gov (United States)

    Wang, Zhentao; Chern, Gia-Wei; Batista, Cristian D.; Barros, Kipton

    2018-03-01

    Fast estimation of the single-particle density matrix is key to many applications in quantum chemistry and condensed matter physics. The best numerical methods leverage the fact that the density matrix elements f(H)ij decay rapidly with distance rij between orbitals. This decay is usually exponential. However, for the special case of metals at zero temperature, algebraic decay of the density matrix appears and poses a significant numerical challenge. We introduce a gradient-based probing method to estimate all local density matrix elements at a computational cost that scales linearly with system size. For zero-temperature metals, the stochastic error scales like S-(d+2)/2d, where d is the dimension and S is a prefactor to the computational cost. The convergence becomes exponential if the system is at finite temperature or is insulating.

  10. Addressing Single and Multiple Bad Data in the Modern PMU-based Power System State Estimation

    DEFF Research Database (Denmark)

    Khazraj, Hesam; Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2017-01-01

    utilization in state estimation can detect and identify single and multiple bad data in redundant and critical measurements. To validate simulations, IEEE 30 bus system are implemented in PowerFactory and Matlab is used to solve proposed state estimation using postprocessing of PMUs and mixed methods. Bad...

  11. Contactless and pose invariant biometric identification using hand surface.

    Science.gov (United States)

    Kanhangad, Vivek; Kumar, Ajay; Zhang, David

    2011-05-01

    This paper presents a novel approach for hand matching that achieves significantly improved performance even in the presence of large hand pose variations. The proposed method utilizes a 3-D digitizer to simultaneously acquire intensity and range images of the user's hand presented to the system in an arbitrary pose. The approach involves determination of the orientation of the hand in 3-D space followed by pose normalization of the acquired 3-D and 2-D hand images. Multimodal (2-D as well as 3-D) palmprint and hand geometry features, which are simultaneously extracted from the user's pose normalized textured 3-D hand, are used for matching. Individual matching scores are then combined using a new dynamic fusion strategy. Our experimental results on the database of 114 subjects with significant pose variations yielded encouraging results. Consistent (across various hand features considered) performance improvement achieved with the pose correction demonstrates the usefulness of the proposed approach for hand based biometric systems with unconstrained and contact-free imaging. The experimental results also suggest that the dynamic fusion approach employed in this work helps to achieve performance improvement of 60% (in terms of EER) over the case when matching scores are combined using the weighted sum rule.

  12. Poppy Crop Height and Capsule Volume Estimation from a Single UAS Flight

    Directory of Open Access Journals (Sweden)

    Faheem Iqbal

    2017-06-01

    Full Text Available The objective of this study was to estimate poppy plant height and capsule volume with remote sensing using an Unmanned Aircraft System (UAS. Data were obtained from field measurements and UAS flights over two poppy crops at Cambridge and Cressy in Tasmania. Imagery acquired from the UAS was used to produce dense point clouds using structure from motion (SfM and multi-view stereopsis (MVS techniques. Dense point clouds were used to generate a digital surface model (DSM and orthophoto mosaic. An RGB index was derived from the orthophoto to extract the bare ground spaces. This bare ground space mask was used to filter the points on the ground, and a digital terrain model (DTM was interpolated from these points. Plant height values were estimated by subtracting the DSM and DTM to generate a Crop Height Model (CHM. UAS-derived plant height (PH and field measured PH in Cambridge were strongly correlated with R2 values ranging from 0.93 to 0.97 for Transect 1 and Transect 2, respectively, while at Cressy results from a single flight provided R2 of 0.97. Therefore, the proposed method can be considered an important step towards crop surface model (CSM generation from a single UAS flight in situations where a bare ground DTM is unavailable. High correlations were found between UAS-derived PH and poppy capsule volume (CV at capsule formation stage (R2 0.74, with relative error of 19.62%. Results illustrate that plant height can be reliably estimated for poppy crops based on a single UAS flight and can be used to predict opium capsule volume at capsule formation stage.

  13. Robust Manhattan Frame Estimation From a Single RGB-D Image

    KAUST Repository

    Bernard Ghanem; Heilbron, Fabian Caba; Niebles, Juan Carlos; Thabet, Ali Kassem

    2015-01-01

    This paper proposes a new framework for estimating the Manhattan Frame (MF) of an indoor scene from a single RGB-D image. Our technique formulates this problem as the estimation of a rotation matrix that best aligns the normals of the captured scene to a canonical world axes. By introducing sparsity constraints, our method can simultaneously estimate the scene MF, the surfaces in the scene that are best aligned to one of three coordinate axes, and the outlier surfaces that do not align with any of the axes. To test our approach, we contribute a new set of annotations to determine ground truth MFs in each image of the popular NYUv2 dataset. We use this new benchmark to experimentally demonstrate that our method is more accurate, faster, more reliable and more robust than the methods used in the literature. We further motivate our technique by showing how it can be used to address the RGB-D SLAM problem in indoor scenes by incorporating it into and improving the performance of a popular RGB-D SLAM method.

  14. Robust Manhattan Frame Estimation From a Single RGB-D Image

    KAUST Repository

    Bernard Ghanem

    2015-06-02

    This paper proposes a new framework for estimating the Manhattan Frame (MF) of an indoor scene from a single RGB-D image. Our technique formulates this problem as the estimation of a rotation matrix that best aligns the normals of the captured scene to a canonical world axes. By introducing sparsity constraints, our method can simultaneously estimate the scene MF, the surfaces in the scene that are best aligned to one of three coordinate axes, and the outlier surfaces that do not align with any of the axes. To test our approach, we contribute a new set of annotations to determine ground truth MFs in each image of the popular NYUv2 dataset. We use this new benchmark to experimentally demonstrate that our method is more accurate, faster, more reliable and more robust than the methods used in the literature. We further motivate our technique by showing how it can be used to address the RGB-D SLAM problem in indoor scenes by incorporating it into and improving the performance of a popular RGB-D SLAM method.

  15. Nanoelectronics: The perspective in microelectronics

    International Nuclear Information System (INIS)

    Mutihac, R.; Mutihac, R.C.; Cicuttin, A.; Colavita, A.A.

    2001-10-01

    The present survey briefly presents the-state-of-the-art in microelectronics, invokes physical considerations in estimating the intrinsic limits of present microelectronic devices, and highlights the future trends in the perspectives of the incoming nanoscale technologies. In order to design artificial systems with molecular precision, molecular brand new engineering methods must be developed, that is, to hold, position, and assemble nanoscale parts in compliance with the laws of physics. In the framework of the nanoscale technologies, the thermodynamically reversible single electron switching systems are considered as ultimate evolutionary end point of electronic logic devices built up at molecular level. (author)

  16. Rhythmic Extended Kalman Filter for Gait Rehabilitation Motion Estimation and Segmentation.

    Science.gov (United States)

    Joukov, Vladimir; Bonnet, Vincent; Karg, Michelle; Venture, Gentiane; Kulic, Dana

    2018-02-01

    This paper proposes a method to enable the use of non-intrusive, small, wearable, and wireless sensors to estimate the pose of the lower body during gait and other periodic motions and to extract objective performance measures useful for physiotherapy. The Rhythmic Extended Kalman Filter (Rhythmic-EKF) algorithm is developed to estimate the pose, learn an individualized model of periodic movement over time, and use the learned model to improve pose estimation. The proposed approach learns a canonical dynamical system model of the movement during online observation, which is used to accurately model the acceleration during pose estimation. The canonical dynamical system models the motion as a periodic signal. The estimated phase and frequency of the motion also allow the proposed approach to segment the motion into repetitions and extract useful features, such as gait symmetry, step length, and mean joint movement and variance. The algorithm is shown to outperform the extended Kalman filter in simulation, on healthy participant data, and stroke patient data. For the healthy participant marching dataset, the Rhythmic-EKF improves joint acceleration and velocity estimates over regular EKF by 40% and 37%, respectively, estimates joint angles with 2.4° root mean squared error, and segments the motion into repetitions with 96% accuracy.

  17. A RD-ESPRIT algorithm for coherent DOA estimation in monostatic MIMO radar using a single pulse

    Science.gov (United States)

    Chen, Chen; Zhang, Xiaofei

    2014-08-01

    This paper discusses the problem of coherent direction of arrival (DOA) estimation in a monostatic multi-input multi-output (MIMO) radar using a single pulse, and proposes a reduced dimension (RD)-estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm. We reconstruct the received data and then utilise it to construct a set of Toeplitz matrices. After that, we use RD-ESPRIT to obtain the DOAs of the sources. The proposed algorithm is effective for coherent angle estimation based on a single pulse, and it has much better angle estimation performance than the forward backward spatial smoothing (FBSS)-ESPRIT algorithm and the ESPRIT-like of Li, as well as very close angle estimation performance to the ESPRIT-like of Han. For complexity comparison, our algorithm has very close complexity to the FBSS-ESPRIT algorithm, and lower complexity than the ESPRIT-like of Han and the ESPRIT-like of Li. Simulation results present the effectiveness and improvement of our approach.

  18. Turkish Primary School Teachers' Opinions about Problem Posing

    Science.gov (United States)

    Kilic, Cigdem

    2013-01-01

    Problem posing is one of the most important topics in a mathematics education. Through problem posing, students gain mathematical abilities and concepts and teachers can evaluate their students and arrange adequate learning environments. The aim of the present study is to investigate Turkish primary school teachers' opinions about problem posing…

  19. Standard diffusive systems are well-posed linear systems

    NARCIS (Netherlands)

    Matignon, Denis; Zwart, Heiko J.

    2004-01-01

    The class of well-posed linear systems as introduced by Salamon has become a well-understood class of systems, see e.g. the work of Weiss and the book of Staffans. Many partial partial differential equations with boundary control and point observation can be formulated as a well-posed linear system.

  20. Comparison of single-grain and small-aliquot OSL dose estimates in <3000 years old river sediments from South India

    International Nuclear Information System (INIS)

    Thomas, P.J.; Jain, M.; Juyal, N.; Singhvi, A.K.

    2005-01-01

    We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples, there was an underestimation in the single-aliquot dose estimates as compared to those from the single grain-the difference between average dose estimates determined by the two methods ranged from ∼1% to 31%. Such a dose underestimation was not detectable in poorly bleached samples. Various possible reasons for the discrepancy between single-grain and small-aliquot dose estimates are discussed. Although there is no satisfactory explanation for this discrepancy, we speculate that the difference in the stimulation wavelengths, 470+/-30nm in the case of single-aliquot and 532nm in the case of single grains, could perhaps be one of the reasons; this may occur because the stimulation wavelength affects the proportion of the medium and slow components in the initial signal

  1. Single point estimation of phenytoin dosing: a reappraisal.

    Science.gov (United States)

    Koup, J R; Gibaldi, M; Godolphin, W

    1981-11-01

    A previously proposed method for estimation of phenytoin dosing requirement using a single serum sample obtained 24 hours after intravenous loading dose (18 mg/Kg) has been re-evaluated. Using more realistic values for the volume of distribution of phenytoin (0.4 to 1.2 L/Kg), simulations indicate that the proposed method will fail to consistently predict dosage requirements. Additional simulations indicate that two samples obtained during the 24 hour interval following the iv loading dose could be used to more reliably predict phenytoin dose requirement. Because of the nonlinear relationship which exists between phenytoin dose administration rate (RO) and the mean steady state serum concentration (CSS), small errors in prediction of the required RO result in much larger errors in CSS.

  2. Posing Problems to Understand Children's Learning of Fractions

    Science.gov (United States)

    Cheng, Lu Pien

    2013-01-01

    In this study, ways in which problem posing activities aid our understanding of children's learning of addition of unlike fractions and product of proper fractions was examined. In particular, how a simple problem posing activity helps teachers take a second, deeper look at children's understanding of fraction concepts will be discussed. The…

  3. Extrapolated HPGe efficiency estimates based on a single calibration measurement

    International Nuclear Information System (INIS)

    Winn, W.G.

    1994-01-01

    Gamma spectroscopists often must analyze samples with geometries for which their detectors are not calibrated. The effort to experimentally recalibrate a detector for a new geometry can be quite time consuming, causing delay in reporting useful results. Such concerns have motivated development of a method for extrapolating HPGe efficiency estimates from an existing single measured efficiency. Overall, the method provides useful preliminary results for analyses that do not require exceptional accuracy, while reliably bracketing the credible range. The estimated efficiency element-of for a uniform sample in a geometry with volume V is extrapolated from the measured element-of 0 of the base sample of volume V 0 . Assuming all samples are centered atop the detector for maximum efficiency, element-of decreases monotonically as V increases about V 0 , and vice versa. Extrapolation of high and low efficiency estimates element-of h and element-of L provides an average estimate of element-of = 1/2 [element-of h + element-of L ] ± 1/2 [element-of h - element-of L ] (general) where an uncertainty D element-of = 1/2 (element-of h - element-of L ] brackets limits for a maximum possible error. The element-of h and element-of L both diverge from element-of 0 as V deviates from V 0 , causing D element-of to increase accordingly. The above concepts guided development of both conservative and refined estimates for element-of

  4. Estimating perception of scene layout properties from global image features.

    Science.gov (United States)

    Ross, Michael G; Oliva, Aude

    2010-01-08

    The relationship between image features and scene structure is central to the study of human visual perception and computer vision, but many of the specifics of real-world layout perception remain unknown. We do not know which image features are relevant to perceiving layout properties, or whether those features provide the same information for every type of image. Furthermore, we do not know the spatial resolutions required for perceiving different properties. This paper describes an experiment and a computational model that provides new insights on these issues. Humans perceive the global spatial layout properties such as dominant depth, openness, and perspective, from a single image. This work describes an algorithm that reliably predicts human layout judgments. This model's predictions are general, not specific to the observers it trained on. Analysis reveals that the optimal spatial resolutions for determining layout vary with the content of the space and the property being estimated. Openness is best estimated at high resolution, depth is best estimated at medium resolution, and perspective is best estimated at low resolution. Given the reliability and simplicity of estimating the global layout of real-world environments, this model could help resolve perceptual ambiguities encountered by more detailed scene reconstruction schemas.

  5. Pose and Motion Estimation Using Dual Quaternion-Based Extended Kalman Filtering

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, J.S.; Abidi, M.A.

    1998-06-01

    A solution to the remote three-dimensional (3-D) measurement problem is presented for a dynamic system given a sequence of two-dimensional (2-D) intensity images of a moving object. The 3-D transformation is modeled as a nonlinear stochastic system with the state estimate providing the six-degree-of-freedom motion and position values as well as structure. The stochastic model uses the iterated extended Kalman filter (IEKF) as a nonlinear estimator and a screw representation of the 3-D transformation based on dual quaternions. Dual quaternions, whose elements are dual numbers, provide a means to represent both rotation and translation in a unified notation. Linear object features, represented as dual vectors, are transformed using the dual quaternion transformation and are then projected to linear features in the image plane. The method has been implemented and tested with both simulated and actual experimental data. Simulation results are provided, along with comparisons to a point-based IEKF method using rotation and translation, to show the relative advantages of this method. Experimental results from testing using a camera mounted on the end effector of a robot arm are also given.

  6. The application of particle filters in single trial event-related potential estimation

    International Nuclear Information System (INIS)

    Mohseni, Hamid R; Nazarpour, Kianoush; Sanei, Saeid; Wilding, Edward L

    2009-01-01

    In this paper, an approach for the estimation of single trial event-related potentials (ST-ERPs) using particle filters (PFs) is presented. The method is based on recursive Bayesian mean square estimation of ERP wavelet coefficients using their previous estimates as prior information. To enable a performance evaluation of the approach in the Gaussian and non-Gaussian distributed noise conditions, we added Gaussian white noise (GWN) and real electroencephalogram (EEG) signals recorded during rest to the simulated ERPs. The results were compared to that of the Kalman filtering (KF) approach demonstrating the robustness of the PF over the KF to the added GWN noise. The proposed method also outperforms the KF when the assumption about the Gaussianity of the noise is violated. We also applied this technique to real EEG potentials recorded in an odd-ball paradigm and investigated the correlation between the amplitude and the latency of the estimated ERP components. Unlike the KF method, for the PF there was a statistically significant negative correlation between amplitude and latency of the estimated ERPs, matching previous neurophysiological findings

  7. Reliable Dual Tensor Model Estimation in Single and Crossing Fibers Based on Jeffreys Prior

    Science.gov (United States)

    Yang, Jianfei; Poot, Dirk H. J.; Caan, Matthan W. A.; Su, Tanja; Majoie, Charles B. L. M.; van Vliet, Lucas J.; Vos, Frans M.

    2016-01-01

    Purpose This paper presents and studies a framework for reliable modeling of diffusion MRI using a data-acquisition adaptive prior. Methods Automated relevance determination estimates the mean of the posterior distribution of a rank-2 dual tensor model exploiting Jeffreys prior (JARD). This data-acquisition prior is based on the Fisher information matrix and enables the assessment whether two tensors are mandatory to describe the data. The method is compared to Maximum Likelihood Estimation (MLE) of the dual tensor model and to FSL’s ball-and-stick approach. Results Monte Carlo experiments demonstrated that JARD’s volume fractions correlated well with the ground truth for single and crossing fiber configurations. In single fiber configurations JARD automatically reduced the volume fraction of one compartment to (almost) zero. The variance in fractional anisotropy (FA) of the main tensor component was thereby reduced compared to MLE. JARD and MLE gave a comparable outcome in data simulating crossing fibers. On brain data, JARD yielded a smaller spread in FA along the corpus callosum compared to MLE. Tract-based spatial statistics demonstrated a higher sensitivity in detecting age-related white matter atrophy using JARD compared to both MLE and the ball-and-stick approach. Conclusions The proposed framework offers accurate and precise estimation of diffusion properties in single and dual fiber regions. PMID:27760166

  8. State estimation for a hexapod robot

    CSIR Research Space (South Africa)

    Lubbe, Estelle

    2015-09-01

    Full Text Available This paper introduces a state estimation methodology for a hexapod robot that makes use of proprioceptive sensors and a kinematic model of the robot. The methodology focuses on providing reliable full pose state estimation for a commercially...

  9. Creativity of Field-dependent and Field-independent Students in Posing Mathematical Problems

    Science.gov (United States)

    Azlina, N.; Amin, S. M.; Lukito, A.

    2018-01-01

    This study aims at describing the creativity of elementary school students with different cognitive styles in mathematical problem-posing. The posed problems were assessed based on three components of creativity, namely fluency, flexibility, and novelty. The free-type problem posing was used in this study. This study is a descriptive research with qualitative approach. Data collections were conducted through written task and task-based interviews. The subjects were two elementary students. One of them is Field Dependent (FD) and the other is Field Independent (FI) which were measured by GEFT (Group Embedded Figures Test). Further, the data were analyzed based on creativity components. The results show thatFD student’s posed problems have fulfilled the two components of creativity namely fluency, in which the subject posed at least 3 mathematical problems, and flexibility, in whichthe subject posed problems with at least 3 different categories/ideas. Meanwhile,FI student’s posed problems have fulfilled all three components of creativity, namely fluency, in which thesubject posed at least 3 mathematical problems, flexibility, in which thesubject posed problems with at least 3 different categories/ideas, and novelty, in which the subject posed problems that are purely the result of her own ideas and different from problems they have known.

  10. Single-Gender Education: Educators' Perspective

    Science.gov (United States)

    Fry, John P.

    2009-01-01

    The examination of educator's views regarding single-gender education was the basis of this study. The significance of the intended study is to show the educator's view of single-gender education as it relates to student academic achievement and behavioral incidents. A quantitative study was conducted utilizing a sample population of regular and…

  11. Is supergravity well-posed?

    International Nuclear Information System (INIS)

    Isenberg, J.; Bao, D.; Yasskin, P.B.

    1983-01-01

    One rather fundamental question concerning supergravity remains unresolved: Is supergravity a well-posed field theory? That is, does a set of certain (Cauchy) data specified on some initial spacelike surface determine a unique, causally propagating spacetime solution of the supergravity field equations (at least in some finite neighborhood of the initial surface)? In this paper, the authors give a very brief report on work directed towards answering this question. (Auth.)

  12. Spontaneous and posed facial expression in Parkinson's disease.

    Science.gov (United States)

    Smith, M C; Smith, M K; Ellgring, H

    1996-09-01

    Spontaneous and posed emotional facial expressions in individuals with Parkinson's disease (PD, n = 12) were compared with those of healthy age-matched controls (n = 12). The intensity and amount of facial expression in PD patients were expected to be reduced for spontaneous but not posed expressions. Emotional stimuli were video clips selected from films, 2-5 min in duration, designed to elicit feelings of happiness, sadness, fear, disgust, or anger. Facial movements were coded using Ekman and Friesen's (1978) Facial Action Coding System (FACS). In addition, participants rated their emotional experience on 9-point Likert scales. The PD group showed significantly less overall facial reactivity than did controls when viewing the films. The predicted Group X Condition (spontaneous vs. posed) interaction effect on smile intensity was found when PD participants with more severe disease were compared with those with milder disease and with controls. In contrast, ratings of emotional experience were similar for both groups. Depression was positively associated with emotion rating but not with measures of facial activity. Spontaneous facial expression appears to be selectively affected in PD, whereas posed expression and emotional experience remain relatively intact.

  13. Novel Position and Speed Estimator for PM Single Phase Brushless D.C. Motor Drives

    DEFF Research Database (Denmark)

    Lepure, Liviu I.; Andreescu, Gheorghe-Daniel; Iles, Doris

    2010-01-01

    A novel position and speed estimator for single phase permanent magnet brushless d.c. (PMBLDC) motor drives, based on flux integration and prior knowledge of ΨPM (θ) is proposed here and an adequate correction algorithm is adopted in order to increase the robustness to noise and to reduce...... the sensitivity to accuracy of flux linkage estimation. A speed and current close loop control is employed based on the Hall signal and the motor is controlled at different speeds in order to validate the proposed estimation algorithm with satisfying results. The position correction effect is analyzed...

  14. Informing Sexual Health Intervention Development in India: Perspectives of Daughters, Mothers, and Service Providers in Mumbai

    Science.gov (United States)

    Adelson, Emiliya; Maitra, Shubhada; Nastasi, Bonnie K.

    2017-01-01

    In India, girls face many challenges that pose a threat to their sexual health and psychological well-being. The authors explore sexual health from the perspectives of adolescent girls, mothers of adolescent girls, and service providers. Focus groups and interview data were analyzed to understand the unique and shared perspectives of stakeholders.…

  15. DeepQA: Improving the estimation of single protein model quality with deep belief networks

    OpenAIRE

    Cao, Renzhi; Bhattacharya, Debswapna; Hou, Jie; Cheng, Jianlin

    2016-01-01

    Background Protein quality assessment (QA) useful for ranking and selecting protein models has long been viewed as one of the major challenges for protein tertiary structure prediction. Especially, estimating the quality of a single protein model, which is important for selecting a few good models out of a large model pool consisting of mostly low-quality models, is still a largely unsolved problem. Results We introduce a novel single-model quality assessment method DeepQA based on deep belie...

  16. Post processing of protein-compound docking for fragment-based drug discovery (FBDD): in-silico structure-based drug screening and ligand-binding pose prediction.

    Science.gov (United States)

    Fukunishi, Yoshifumi

    2010-01-01

    For fragment-based drug development, both hit (active) compound prediction and docking-pose (protein-ligand complex structure) prediction of the hit compound are important, since chemical modification (fragment linking, fragment evolution) subsequent to the hit discovery must be performed based on the protein-ligand complex structure. However, the naïve protein-compound docking calculation shows poor accuracy in terms of docking-pose prediction. Thus, post-processing of the protein-compound docking is necessary. Recently, several methods for the post-processing of protein-compound docking have been proposed. In FBDD, the compounds are smaller than those for conventional drug screening. This makes it difficult to perform the protein-compound docking calculation. A method to avoid this problem has been reported. Protein-ligand binding free energy estimation is useful to reduce the procedures involved in the chemical modification of the hit fragment. Several prediction methods have been proposed for high-accuracy estimation of protein-ligand binding free energy. This paper summarizes the various computational methods proposed for docking-pose prediction and their usefulness in FBDD.

  17. Monte Carlo uncertainty analysis of dose estimates in radiochromic film dosimetry with single-channel and multichannel algorithms.

    Science.gov (United States)

    Vera-Sánchez, Juan Antonio; Ruiz-Morales, Carmen; González-López, Antonio

    2018-03-01

    To provide a multi-stage model to calculate uncertainty in radiochromic film dosimetry with Monte-Carlo techniques. This new approach is applied to single-channel and multichannel algorithms. Two lots of Gafchromic EBT3 are exposed in two different Varian linacs. They are read with an EPSON V800 flatbed scanner. The Monte-Carlo techniques in uncertainty analysis provide a numerical representation of the probability density functions of the output magnitudes. From this numerical representation, traditional parameters of uncertainty analysis as the standard deviations and bias are calculated. Moreover, these numerical representations are used to investigate the shape of the probability density functions of the output magnitudes. Also, another calibration film is read in four EPSON scanners (two V800 and two 10000XL) and the uncertainty analysis is carried out with the four images. The dose estimates of single-channel and multichannel algorithms show a Gaussian behavior and low bias. The multichannel algorithms lead to less uncertainty in the final dose estimates when the EPSON V800 is employed as reading device. In the case of the EPSON 10000XL, the single-channel algorithms provide less uncertainty in the dose estimates for doses higher than four Gy. A multi-stage model has been presented. With the aid of this model and the use of the Monte-Carlo techniques, the uncertainty of dose estimates for single-channel and multichannel algorithms are estimated. The application of the model together with Monte-Carlo techniques leads to a complete characterization of the uncertainties in radiochromic film dosimetry. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  18. Estimating skin sensitization potency from a single dose LLNA.

    Science.gov (United States)

    Roberts, David W

    2015-04-01

    Skin sensitization is an important aspect of safety assessment. The mouse local lymph node assay (LLNA) developed in the 1990 s is an in vivo test used for skin sensitization hazard identification and characterization. More recently a reduced version of the LLNA (rLLNA) has been developed as a means of identifying, but not quantifying, sensitization hazard. The work presented here is aimed at enabling rLLNA data to be used to give quantitative potency information that can be used, inter alia, in modeling and read-across approaches to non-animal based potency estimation. A probit function has been derived enabling estimation of EC3 from a single dose. This has led to development of a modified version of the rLLNA, whereby as a general principle the SI value at 10%, or at a lower concentration if 10% is not testable, is used to calculate the EC3. This version of the rLLNA has been evaluated against a selection of chemicals for which full LLNA data are available, and has been shown to give EC3 values in good agreement with those derived from the full LLNA. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Real-time stop sign detection and distance estimation using a single camera

    Science.gov (United States)

    Wang, Wenpeng; Su, Yuxuan; Cheng, Ming

    2018-04-01

    In modern world, the drastic development of driver assistance system has made driving a lot easier than before. In order to increase the safety onboard, a method was proposed to detect STOP sign and estimate distance using a single camera. In STOP sign detection, LBP-cascade classifier was applied to identify the sign in the image, and the principle of pinhole imaging was based for distance estimation. Road test was conducted using a detection system built with a CMOS camera and software developed by Python language with OpenCV library. Results shows that that the proposed system reach a detection accuracy of maximum of 97.6% at 10m, a minimum of 95.00% at 20m, and 5% max error in distance estimation. The results indicate that the system is effective and has the potential to be used in both autonomous driving and advanced driver assistance driving systems.

  20. Taking into account latency, amplitude, and morphology: improved estimation of single-trial ERPs by wavelet filtering and multiple linear regression.

    Science.gov (United States)

    Hu, L; Liang, M; Mouraux, A; Wise, R G; Hu, Y; Iannetti, G D

    2011-12-01

    Across-trial averaging is a widely used approach to enhance the signal-to-noise ratio (SNR) of event-related potentials (ERPs). However, across-trial variability of ERP latency and amplitude may contain physiologically relevant information that is lost by across-trial averaging. Hence, we aimed to develop a novel method that uses 1) wavelet filtering (WF) to enhance the SNR of ERPs and 2) a multiple linear regression with a dispersion term (MLR(d)) that takes into account shape distortions to estimate the single-trial latency and amplitude of ERP peaks. Using simulated ERP data sets containing different levels of noise, we provide evidence that, compared with other approaches, the proposed WF+MLR(d) method yields the most accurate estimate of single-trial ERP features. When applied to a real laser-evoked potential data set, the WF+MLR(d) approach provides reliable estimation of single-trial latency, amplitude, and morphology of ERPs and thereby allows performing meaningful correlations at single-trial level. We obtained three main findings. First, WF significantly enhances the SNR of single-trial ERPs. Second, MLR(d) effectively captures and measures the variability in the morphology of single-trial ERPs, thus providing an accurate and unbiased estimate of their peak latency and amplitude. Third, intensity of pain perception significantly correlates with the single-trial estimates of N2 and P2 amplitude. These results indicate that WF+MLR(d) can be used to explore the dynamics between different ERP features, behavioral variables, and other neuroimaging measures of brain activity, thus providing new insights into the functional significance of the different brain processes underlying the brain responses to sensory stimuli.

  1. Efficient structure from motion on large scenes using UAV with position and pose information

    Science.gov (United States)

    Teng, Xichao; Yu, Qifeng; Shang, Yang; Luo, Jing; Wang, Gang

    2018-04-01

    In this paper, we exploit prior information from global positioning systems and inertial measurement units to speed up the process of large scene reconstruction from images acquired by Unmanned Aerial Vehicles. We utilize weak pose information and intrinsic parameter to obtain the projection matrix for each view. As compared to unmanned aerial vehicles' flight altitude, topographic relief can usually be ignored, we assume that the scene is flat and use weak perspective camera to get projective transformations between two views. Furthermore, we propose an overlap criterion and select potentially matching view pairs between projective transformed views. A robust global structure from motion method is used for image based reconstruction. Our real world experiments show that the approach is accurate, scalable and computationally efficient. Moreover, projective transformations between views can also be used to eliminate false matching.

  2. Challenging Preservice Teacher Perspectives: Immigration, Equitable Opportunity, and Advocacy

    Science.gov (United States)

    Nino, Mary Catherine

    2012-01-01

    In this conceptual article, I use five questions that were posed in 1936 about immigration and the education of immigrant children as a lens to examine contemporary perspectives on immigration and the education of immigrant children. Dispelling myths about immigrant students and English learners has been a consistent concern in our country. These…

  3. Bias Corrections for Standardized Effect Size Estimates Used with Single-Subject Experimental Designs

    Science.gov (United States)

    Ugille, Maaike; Moeyaert, Mariola; Beretvas, S. Natasha; Ferron, John M.; Van den Noortgate, Wim

    2014-01-01

    A multilevel meta-analysis can combine the results of several single-subject experimental design studies. However, the estimated effects are biased if the effect sizes are standardized and the number of measurement occasions is small. In this study, the authors investigated 4 approaches to correct for this bias. First, the standardized effect…

  4. Assessing the risk posed by natural hazards to infrastructures

    Science.gov (United States)

    Eidsvig, Unni Marie K.; Kristensen, Krister; Vidar Vangelsten, Bjørn

    2017-03-01

    This paper proposes a model for assessing the risk posed by natural hazards to infrastructures, with a focus on the indirect losses and loss of stability for the population relying on the infrastructure. The model prescribes a three-level analysis with increasing level of detail, moving from qualitative to quantitative analysis. The focus is on a methodology for semi-quantitative analyses to be performed at the second level. The purpose of this type of analysis is to perform a screening of the scenarios of natural hazards threatening the infrastructures, identifying the most critical scenarios and investigating the need for further analyses (third level). The proposed semi-quantitative methodology considers the frequency of the natural hazard, different aspects of vulnerability, including the physical vulnerability of the infrastructure itself, and the societal dependency on the infrastructure. An indicator-based approach is applied, ranking the indicators on a relative scale according to pre-defined ranking criteria. The proposed indicators, which characterise conditions that influence the probability of an infrastructure malfunctioning caused by a natural event, are defined as (1) robustness and buffer capacity, (2) level of protection, (3) quality/level of maintenance and renewal, (4) adaptability and quality of operational procedures and (5) transparency/complexity/degree of coupling. Further indicators describe conditions influencing the socio-economic consequences of the infrastructure malfunctioning, such as (1) redundancy and/or substitution, (2) cascading effects and dependencies, (3) preparedness and (4) early warning, emergency response and measures. The aggregated risk estimate is a combination of the semi-quantitative vulnerability indicators, as well as quantitative estimates of the frequency of the natural hazard, the potential duration of the infrastructure malfunctioning (e.g. depending on the required restoration effort) and the number of users of

  5. A Support System for the Electric Appliance Control Using Pose Recognition

    Science.gov (United States)

    Kawano, Takuya; Yamamoto, Kazuhiko; Kato, Kunihito; Hongo, Hitoshi

    In this paper, we propose an electric appliance control support system for aged and bedridden people using pose recognition. We proposed a pose recognition system that distinguishes between seven poses of the user on the bed. First, the face and arm regions of the user are detected by using the skin color. Our system focuses a recognition region surrounding the face region. Next, the higher order local autocorrelation features within the region are extracted. The linear discriminant analysis creates the coefficient matrix that can optimally distinguish among training data from the seven poses. Our algorithm can recognize the seven poses even if the subject wears different clothes and slightly shifts or slants on the bed. From the experimental results, our system achieved an accuracy rate of over 99 %. Then, we show that it possibles to construct one of a user-friendly system.

  6. Patient-specific parameter estimation in single-ventricle lumped circulation models under uncertainty

    Science.gov (United States)

    Schiavazzi, Daniele E.; Baretta, Alessia; Pennati, Giancarlo; Hsia, Tain-Yen; Marsden, Alison L.

    2017-01-01

    Summary Computational models of cardiovascular physiology can inform clinical decision-making, providing a physically consistent framework to assess vascular pressures and flow distributions, and aiding in treatment planning. In particular, lumped parameter network (LPN) models that make an analogy to electrical circuits offer a fast and surprisingly realistic method to reproduce the circulatory physiology. The complexity of LPN models can vary significantly to account, for example, for cardiac and valve function, respiration, autoregulation, and time-dependent hemodynamics. More complex models provide insight into detailed physiological mechanisms, but their utility is maximized if one can quickly identify patient specific parameters. The clinical utility of LPN models with many parameters will be greatly enhanced by automated parameter identification, particularly if parameter tuning can match non-invasively obtained clinical data. We present a framework for automated tuning of 0D lumped model parameters to match clinical data. We demonstrate the utility of this framework through application to single ventricle pediatric patients with Norwood physiology. Through a combination of local identifiability, Bayesian estimation and maximum a posteriori simplex optimization, we show the ability to automatically determine physiologically consistent point estimates of the parameters and to quantify uncertainty induced by errors and assumptions in the collected clinical data. We show that multi-level estimation, that is, updating the parameter prior information through sub-model analysis, can lead to a significant reduction in the parameter marginal posterior variance. We first consider virtual patient conditions, with clinical targets generated through model solutions, and second application to a cohort of four single-ventricle patients with Norwood physiology. PMID:27155892

  7. Flexible Polyhedral Surfaces with Two Flat Poses

    Directory of Open Access Journals (Sweden)

    Hellmuth Stachel

    2015-05-01

    Full Text Available We present three types of polyhedral surfaces, which are continuously flexible and have not only an initial pose, where all faces are coplanar, but pass during their self-motion through another pose with coplanar faces (“flat pose”. These surfaces are examples of so-called rigid origami, since we only admit exact flexions, i.e., each face remains rigid during the motion; only the dihedral angles vary. We analyze the geometry behind Miura-ori and address Kokotsakis’ example of a flexible tessellation with the particular case of a cyclic quadrangle. Finally, we recall Bricard’s octahedra of Type 3 and their relation to strophoids.

  8. Review of the Risks Posed to Drinking Water by Man-Made Nanoparticels

    DEFF Research Database (Denmark)

    Tiede, K.; Westerhoff, P.; Hansen, Steffen Foss

    an estimate of the amount of exposure to a range of ENPs from drinking water as well as a relative qualitative risk of exposure to ENPs from drinking water compared to other routes. A range of metal, metal oxide and organic-based ENPs were identified that have the potential to contaminate drinking waters...... drinking waters. In order to address these concerns, the U.K. Drinking Water Inspectorate (DWI) has published a "Review of the risks posed to drinking water by man-made nanoparticles"(DWI 70/2/246). The study, which was funded by the Department for Food and Rural Affairs (Defra), was undertaken by the Food...... (such as ENPs that are produced in large quantities or are used in a free form) were identified and categorised. The classification was based on a categorisation framework to aid exposure assessment of nanomaterials in consumer products. A conservative approach was then used to estimate worst case...

  9. Inverse and Ill-posed Problems Theory and Applications

    CERN Document Server

    Kabanikhin, S I

    2011-01-01

    The text demonstrates the methods for proving the existence (if et all) and finding of inverse and ill-posed problems solutions in linear algebra, integral and operator equations, integral geometry, spectral inverse problems, and inverse scattering problems. It is given comprehensive background material for linear ill-posed problems and for coefficient inverse problems for hyperbolic, parabolic, and elliptic equations. A lot of examples for inverse problems from physics, geophysics, biology, medicine, and other areas of application of mathematics are included.

  10. Pose and Shape Reconstruction of a Noncooperative Spacecraft Using Camera and Range Measurements

    Directory of Open Access Journals (Sweden)

    Renato Volpe

    2017-01-01

    Full Text Available Recent interest in on-orbit proximity operations has pushed towards the development of autonomous GNC strategies. In this sense, optical navigation enables a wide variety of possibilities as it can provide information not only about the kinematic state but also about the shape of the observed object. Various mission architectures have been either tested in space or studied on Earth. The present study deals with on-orbit relative pose and shape estimation with the use of a monocular camera and a distance sensor. The goal is to develop a filter which estimates an observed satellite’s relative position, velocity, attitude, and angular velocity, along with its shape, with the measurements obtained by a camera and a distance sensor mounted on board a chaser which is on a relative trajectory around the target. The filter’s efficiency is proved with a simulation on a virtual target object. The results of the simulation, even though relevant to a simplified scenario, show that the estimation process is successful and can be considered a promising strategy for a correct and safe docking maneuver.

  11. Determining the Performances of Pre-Service Primary School Teachers in Problem Posing Situations

    Science.gov (United States)

    Kilic, Cigdem

    2013-01-01

    This study examined the problem posing strategies of pre-service primary school teachers in different problem posing situations (PPSs) and analysed the issues they encounter while posing problems. A problem posing task consisting of six PPSs (two free, two structured, and two semi-structured situations) was delivered to 40 participants.…

  12. Direction of Arrival Estimation with a Novel Single-Port Smart Antenna

    Directory of Open Access Journals (Sweden)

    Chen Sun

    2004-08-01

    Full Text Available A novel direction of arrival (DOA estimation technique that uses the conventional multiple-signal classification (MUSIC algorithm with periodic signals is applied to a single-port smart antenna. Results show that the proposed method gives a high-resolution (1 degree DOA estimation in an uncorrelated signal environment. The novelty lies in that the MUSIC algorithm is applied to a simplified antenna configuration. Only 1 analogue-to-digital converter (ADC is used in this antenna, which features low power consumption, low cost, and ease of fabrication. Modifications to the conventional MUSIC algorithm do not bring much additional complexity. The proposed technique is also free from the negative influence by the mutual coupling among antenna elements. Therefore, it offers an economical way to extensively implement smart antennas into the existing wireless mobile communications systems, especially at the power consumption limited mobile terminals such as laptops in wireless networks.

  13. Tooth display and lip position during spontaneous and posed smiling in adults.

    Science.gov (United States)

    Van Der Geld, Pieter; Oosterveld, Paul; Berge, Stefaan J; Kuijpers-Jagtman, Anne M

    2008-08-01

    To analyze differences in tooth display, lip-line height, and smile width between the posed smiling record, traditionally produced for orthodontic diagnosis, and the spontaneous (Duchenne) smile of joy. The faces of 122 male participants were each filmed during spontaneous and posed smiling. Spontaneous smiles were elicited through the participants watching a comical movie. Maxillary and mandibular lip-line heights, tooth display, and smile width were measured using a digital videographic method for smile analysis. Paired sample t-tests were used to compare measurements of posed and spontaneous smiling. Maxillary lip-line heights during spontaneous smiling were significantly higher than during posed smiling. Compared to spontaneous smiling, tooth display in the (pre)molar area during posed smiling decreased by up to 30%, along with a significant reduction of smile width. During posed smiling, also mandibular lip-line heights changed and the teeth were more covered by the lower lip than during spontaneous smiling. Reduced lip-line heights, tooth display, and smile width on a posed smiling record can have implications for the diagnostics of lip-line height, smile arc, buccal corridors, and plane of occlusion. Spontaneous smiling records next to posed smiling records are therefore recommended for diagnostic purposes. Because of the dynamic nature of spontaneous smiling, it is proposed to switch to dynamic video recording of the smile.

  14. Compensating Pose Uncertainties through Appropriate Gripper Finger Cutouts

    Directory of Open Access Journals (Sweden)

    Wolniakowski Adam

    2018-03-01

    Full Text Available The gripper finger design is a recurring problem in many robotic grasping platforms used in industry. The task of switching the gripper configuration to accommodate for a new batch of objects typically requires engineering expertise, and is a lengthy and costly iterative trial-and-error process. One of the open challenges is the need for the gripper to compensate for uncertainties inherent to the workcell, e.g. due to errors in calibration, inaccurate pose estimation from the vision system, or object deformation. In this paper, we present an analysis of gripper uncertainty compensating capabilities in a sample industrial object grasping scenario for a finger that was designed using an automated simulation-based geometry optimization method (Wolniakowski et al., 2013, 2015. We test the developed gripper with a set of grasps subjected to structured perturbation in a simulation environment and in the real-world setting. We provide a comparison of the data obtained by using both of these approaches. We argue that the strong correspondence observed in results validates the use of dynamic simulation for the gripper finger design and optimization.

  15. Relative and single particle diffusion estimates determined from smoke plume photographs

    International Nuclear Information System (INIS)

    Nappo, C.J. Jr.

    1978-01-01

    The formula given by Gifford (1959) for obtaining space-varying values of particle dispersion parameters from photographs of smoke puffs and plumes has been applied to high-altitude U-2 photographs of a long smoke plume generated at the Idaho National Engineering Laboratory near Idaho Falls. The turbulence time scale derived from the photographs was found to be in good agreement with estimates obtained within the framework of single- and two-particle diffusion theory applied to wind speed and direction data from a tower near the smoke source

  16. Compressive Video Recovery Using Block Match Multi-Frame Motion Estimation Based on Single Pixel Cameras

    Directory of Open Access Journals (Sweden)

    Sheng Bi

    2016-03-01

    Full Text Available Compressive sensing (CS theory has opened up new paths for the development of signal processing applications. Based on this theory, a novel single pixel camera architecture has been introduced to overcome the current limitations and challenges of traditional focal plane arrays. However, video quality based on this method is limited by existing acquisition and recovery methods, and the method also suffers from being time-consuming. In this paper, a multi-frame motion estimation algorithm is proposed in CS video to enhance the video quality. The proposed algorithm uses multiple frames to implement motion estimation. Experimental results show that using multi-frame motion estimation can improve the quality of recovered videos. To further reduce the motion estimation time, a block match algorithm is used to process motion estimation. Experiments demonstrate that using the block match algorithm can reduce motion estimation time by 30%.

  17. Audiovisual Head Orientation Estimation with Particle Filtering in Multisensor Scenarios

    Directory of Open Access Journals (Sweden)

    Javier Hernando

    2007-07-01

    Full Text Available This article presents a multimodal approach to head pose estimation of individuals in environments equipped with multiple cameras and microphones, such as SmartRooms or automatic video conferencing. Determining the individuals head orientation is the basis for many forms of more sophisticated interactions between humans and technical devices and can also be used for automatic sensor selection (camera, microphone in communications or video surveillance systems. The use of particle filters as a unified framework for the estimation of the head orientation for both monomodal and multimodal cases is proposed. In video, we estimate head orientation from color information by exploiting spatial redundancy among cameras. Audio information is processed to estimate the direction of the voice produced by a speaker making use of the directivity characteristics of the head radiation pattern. Furthermore, two different particle filter multimodal information fusion schemes for combining the audio and video streams are analyzed in terms of accuracy and robustness. In the first one, fusion is performed at a decision level by combining each monomodal head pose estimation, while the second one uses a joint estimation system combining information at data level. Experimental results conducted over the CLEAR 2006 evaluation database are reported and the comparison of the proposed multimodal head pose estimation algorithms with the reference monomodal approaches proves the effectiveness of the proposed approach.

  18. Prospective elementary school teachers’ ways of making sense of mathematical problem posing (Modos en que futuros profesores de primaria dan sentido a la invención de problemas matemáticos

    Directory of Open Access Journals (Sweden)

    Olive Chapman

    2012-06-01

    Full Text Available The study tackled prospective teachers’ sense-making of mathematical problem posing and the impact of posing different contextual problems on their learning. Focus was on the generation of new problems and reformulation of given problems. Participants were 40 prospective elementary teachers. The findings provide insights into possible ways these teachers could make sense of problem posing of contextual mathematical problems and the learning afforded by posing diverse problems. Highlighted are five perspectives and nine categories of problem posing tasks to support development of proficiency in problem-posing knowledge for teaching. El estudio indagó sobre los modos en que futuros profesores de primaria dan sentido a la invención de problemas matemáticos y el impacto de plantear diferentes problemas contextualizados en su aprendizaje. El foco fue la invención de nuevos problemas y la reformulación de otros dados. Los participantes fueron 40 futuros maestros de primaria. Los resultados proporcionan elementos sobre posibles modos en que estos maestros dan sentido a la invención de problemas matemáticos y el aprendizaje que ofrece plantear diversos problemas. Se destacan cinco perspectivas y nueve categorías de tareas en la invención de problemas para apoyar el desarrollo de la competencia de plantear problemas en la enseñanza.

  19. Hysteresis and Phase Transitions in a Lattice Regularization of an Ill-Posed Forward-Backward Diffusion Equation

    Science.gov (United States)

    Helmers, Michael; Herrmann, Michael

    2018-03-01

    We consider a lattice regularization for an ill-posed diffusion equation with a trilinear constitutive law and study the dynamics of phase interfaces in the parabolic scaling limit. Our main result guarantees for a certain class of single-interface initial data that the lattice solutions satisfy asymptotically a free boundary problem with a hysteretic Stefan condition. The key challenge in the proof is to control the microscopic fluctuations that are inevitably produced by the backward diffusion when a particle passes the spinodal region.

  20. Estimating brain connectivity when few data points are available: Perspectives and limitations.

    Science.gov (United States)

    Antonacci, Yuri; Toppi, Jlenia; Caschera, Stefano; Anzolin, Alessandra; Mattia, Donatella; Astolfi, Laura

    2017-07-01

    Methods based on the use of multivariate autoregressive modeling (MVAR) have proved to be an accurate and flexible tool for the estimation of brain functional connectivity. The multivariate approach, however, implies the use of a model whose complexity (in terms of number of parameters) increases quadratically with the number of signals included in the problem. This can often lead to an underdetermined problem and to the condition of multicollinearity. The aim of this paper is to introduce and test an approach based on Ridge Regression combined with a modified version of the statistics usually adopted for these methods, to broaden the estimation of brain connectivity to those conditions in which current methods fail, due to the lack of enough data points. We tested the performances of this new approach, in comparison with the classical approach based on ordinary least squares (OLS), by means of a simulation study implementing different ground-truth networks, under different network sizes and different levels of data points. Simulation results showed that the new approach provides better performances, in terms of accuracy of the parameters estimation and false positives/false negatives rates, in all conditions related to a low data points/model dimension ratio, and may thus be exploited to estimate and validate estimated patterns at single-trial level or when short time data segments are available.

  1. Locating binding poses in protein-ligand systems using reconnaissance metadynamics

    Science.gov (United States)

    Söderhjelm, Pär; Tribello, Gareth A.; Parrinello, Michele

    2012-01-01

    A molecular dynamics-based protocol is proposed for finding and scoring protein-ligand binding poses. This protocol uses the recently developed reconnaissance metadynamics method, which employs a self-learning algorithm to construct a bias that pushes the system away from the kinetic traps where it would otherwise remain. The exploration of phase space with this algorithm is shown to be roughly six to eight times faster than unbiased molecular dynamics and is only limited by the time taken to diffuse about the surface of the protein. We apply this method to the well-studied trypsin–benzamidine system and show that we are able to refind all the poses obtained from a reference EADock blind docking calculation. These poses can be scored based on the length of time the system remains trapped in the pose. Alternatively, one can perform dimensionality reduction on the output trajectory and obtain a map of phase space that can be used in more expensive free-energy calculations. PMID:22440749

  2. Mathematical Thinking and Creativity through Mathematical Problem Posing and Solving

    Directory of Open Access Journals (Sweden)

    María F. Ayllón

    2016-04-01

    Full Text Available This work shows the relationship between the development of mathematical thinking and creativity with mathematical problem posing and solving. Creativity and mathematics are disciplines that do not usually appear together. Both concepts constitute complex processes sharing elements, such as fluency (number of ideas, flexibility (range of ideas, novelty (unique idea and elaboration (idea development. These factors contribute, among others, to the fact that schoolchildren are competent in mathematics. The problem solving and posing are a very powerful evaluation tool that shows the mathematical reasoning and creative level of a person. Creativity is part of the mathematics education and is a necessary ingredient to perform mathematical assignments. This contribution presents some important research works about problem posing and solving related to the development of mathematical knowledge and creativity. To that end, it is based on various beliefs reflected in the literature with respect to notions of creativity, problem solving and posing.

  3. A Grasp-Pose Generation Method Based on Gaussian Mixture Models

    Directory of Open Access Journals (Sweden)

    Wenjia Wu

    2015-11-01

    Full Text Available A Gaussian Mixture Model (GMM-based grasp-pose generation method is proposed in this paper. Through offline training, the GMM is set up and used to depict the distribution of the robot's reachable orientations. By dividing the robot's workspace into small 3D voxels and training the GMM for each voxel, a look-up table covering all the workspace is built with the x, y and z positions as the index and the GMM as the entry. Through the definition of Task Space Regions (TSR, an object's feasible grasp poses are expressed as a continuous region. With the GMM, grasp poses can be preferentially sampled from regions with high reachability probabilities in the online grasp-planning stage. The GMM can also be used as a preliminary judgement of a grasp pose's reachability. Experiments on both a simulated and a real robot show the superiority of our method over the existing method.

  4. Estimation of bias with the single-zone assumption in measurement of residential air exchange using the perfluorocarbon tracer gas method.

    Science.gov (United States)

    Van Ryswyk, K; Wallace, L; Fugler, D; MacNeill, M; Héroux, M È; Gibson, M D; Guernsey, J R; Kindzierski, W; Wheeler, A J

    2015-12-01

    Residential air exchange rates (AERs) are vital in understanding the temporal and spatial drivers of indoor air quality (IAQ). Several methods to quantify AERs have been used in IAQ research, often with the assumption that the home is a single, well-mixed air zone. Since 2005, Health Canada has conducted IAQ studies across Canada in which AERs were measured using the perfluorocarbon tracer (PFT) gas method. Emitters and detectors of a single PFT gas were placed on the main floor to estimate a single-zone AER (AER(1z)). In three of these studies, a second set of emitters and detectors were deployed in the basement or second floor in approximately 10% of homes for a two-zone AER estimate (AER(2z)). In total, 287 daily pairs of AER(2z) and AER(1z) estimates were made from 35 homes across three cities. In 87% of the cases, AER(2z) was higher than AER(1z). Overall, the AER(1z) estimates underestimated AER(2z) by approximately 16% (IQR: 5-32%). This underestimate occurred in all cities and seasons and varied in magnitude seasonally, between homes, and daily, indicating that when measuring residential air exchange using a single PFT gas, the assumption of a single well-mixed air zone very likely results in an under prediction of the AER. The results of this study suggest that the long-standing assumption that a home represents a single well-mixed air zone may result in a substantial negative bias in air exchange estimates. Indoor air quality professionals should take this finding into consideration when developing study designs or making decisions related to the recommendation and installation of residential ventilation systems. © 2014 Her Majesty the Queen in Right of Canada. Indoor Air published by John Wiley & Sons Ltd Reproduced with the permission of the Minister of Health Canada.

  5. Investigation of Problem-Solving and Problem-Posing Abilities of Seventh-Grade Students

    Science.gov (United States)

    Arikan, Elif Esra; Ünal, Hasan

    2015-01-01

    This study aims to examine the effect of multiple problem-solving skills on the problem-posing abilities of gifted and non-gifted students and to assess whether the possession of such skills can predict giftedness or affect problem-posing abilities. Participants' metaphorical images of problem posing were also explored. Participants were 20 gifted…

  6. Lightning stroke distance estimation from single station observation and validation with WWLLN data

    Directory of Open Access Journals (Sweden)

    V. Ramachandran

    2007-07-01

    Full Text Available A simple technique to estimate the distance of the lightning strikes d with a single VLF electromagnetic wave receiver at a single station is described. The technique is based on the recording of oscillatory waveforms of the electric fields of sferics. Even though the process of estimating d using the waveform is a rather classical one, a novel and simple procedure for finding d is proposed in this paper. The procedure adopted provides two independent estimates of the distance of the stroke. The accuracy of measurements has been improved by employing high speed (333 ns sampling rate signal processing techniques. GPS time is used as the reference time, which enables us to compare the calculated distances of the lightning strikes, by both methods, with those calculated from the data obtained by the World-Wide Lightning Location Network (WWLLN, which uses a multi-station technique. The estimated distances of the lightning strikes (77, whose times correlated, ranged from ~3000–16 250 km. When dd compared with those calculated with the multi-station lightning location system is ~4.7%, while for all the strokes it was ~8.8%. One of the lightnings which was recorded by WWLLN, whose field pattern was recorded and the spectrogram of the sferic was also recorded at the site, is analyzed in detail. The deviations in d calculated from the field pattern and from the arrival time of the sferic were 3.2% and 1.5%, respectively, compared to d calculated from the WWLLN location. FFT analysis of the waveform showed that only a narrow band of frequencies is received at the site, which is confirmed by the intensity of the corresponding sferic in the spectrogram.

  7. Comparison of single-grain and small-aliquot OSL dose estimates in < 3000 years old river sediments from South India

    DEFF Research Database (Denmark)

    Thomas, P.J.; Jain, M.; Juyal, N.

    2005-01-01

    We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples, there wa......We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples......, there was an underestimation in the single-aliquot dose estimates as compared to those from the single grain-the difference between average dose estimates determined by the two methods ranged from similar to 1% to 31%. Such a dose underestimation was not detectable in poorly bleached samples. Various possible reasons...... perhaps be one of the reasons; this may occur because the stimulation wavelength affects the proportion of the medium and slow components in the initial signal. (c) 2004 Elsevier Ltd. All rights reserved....

  8. Preparatory power posing affects nonverbal presence and job interview performance.

    Science.gov (United States)

    Cuddy, Amy J C; Wilmuth, Caroline A; Yap, Andy J; Carney, Dana R

    2015-07-01

    The authors tested whether engaging in expansive (vs. contractive) "power poses" before a stressful job interview--preparatory power posing--would enhance performance during the interview. Participants adopted high-power (i.e., expansive, open) poses or low-power (i.e., contractive, closed) poses, and then prepared and delivered a speech to 2 evaluators as part of a mock job interview. All interview speeches were videotaped and coded for overall performance and hireability and for 2 potential mediators: verbal content (e.g., structure, content) and nonverbal presence (e.g., captivating, enthusiastic). As predicted, those who prepared for the job interview with high- (vs. low-) power poses performed better and were more likely to be chosen for hire; this relation was mediated by nonverbal presence, but not by verbal content. Although previous research has focused on how a nonverbal behavior that is enacted during interactions and observed by perceivers affects how those perceivers evaluate and respond to the actor, this experiment focused on how a nonverbal behavior that is enacted before the interaction and unobserved by perceivers affects the actor's performance, which, in turn, affects how perceivers evaluate and respond to the actor. This experiment reveals a theoretically novel and practically informative result that demonstrates the causal relation between preparatory nonverbal behavior and subsequent performance and outcomes. (c) 2015 APA, all rights reserved).

  9. Inline state of health estimation of lithium-ion batteries using state of charge calculation

    Science.gov (United States)

    Sepasi, Saeed; Ghorbani, Reza; Liaw, Bor Yann

    2015-12-01

    The determination of state-of-health (SOH) and state-of-charge (SOC) is challenging and remains as an active research area in academia and industry due to its importance for Li-ion battery applications. The estimation process poses more challenges after substantial battery aging. This paper presents an inline SOH and SOC estimation method for Li-ion battery packs, specifically for those based on LiFePO4 chemistry. This new hybridized SOC and SOH estimator can be used for battery packs. Inline estimated model parameters were used in a compounded SOC + SOH estimator consisting of the SOC calculation based on coulomb counting method as an expedient approach and an SOH observer using an extended Kalman filter (EKF) technique for calibrating the estimates from the coulomb counting method. The algorithm's low SOC and SOH estimation error, fast response time, and less-demanding computational requirement make it practical for on-board estimations. The simulation and experimental results, along with the test bed structure, are presented to validate the proposed methodology on a single cell and a 3S1P LiFePO4 battery pack.

  10. Multiscale analysis for ill-posed problems with semi-discrete Tikhonov regularization

    International Nuclear Information System (INIS)

    Zhong, Min; Lu, Shuai; Cheng, Jin

    2012-01-01

    Using compactly supported radial basis functions of varying radii, Wendland has shown how a multiscale analysis can be applied to the approximation of Sobolev functions on a bounded domain, when the available data are discrete and noisy. Here, we examine the application of this analysis to the solution of linear moderately ill-posed problems using semi-discrete Tikhonov–Phillips regularization. As in Wendland’s work, the actual multiscale approximation is constructed by a sequence of residual corrections, where different support radii are employed to accommodate different scales. The convergence of the algorithm for noise-free data is given. Based on the Morozov discrepancy principle, a posteriori parameter choice rule and error estimates for the noisy data are derived. Two numerical examples are presented to illustrate the appropriateness of the proposed method. (paper)

  11. Functional Perspectives on Emotion, Behavior, and Cognition

    OpenAIRE

    Logan A. Berg; Kathleen E. Darbor; Heather C. Lench

    2013-01-01

    This Editorial reviews the challenges and advantages posed by a functional perspective on the relationships among emotion, behavior, and cognition. We identify the core themes among the articles published as part of this Special Issue. The articles generally address two important questions: (1) are emotions functional and what is their impact on behavioral and cognitive processes, and (2) how do the interactions among emotion, cognition, and behavior play out in particular situations that pre...

  12. Greedy solution of ill-posed problems: error bounds and exact inversion

    International Nuclear Information System (INIS)

    Denis, L; Lorenz, D A; Trede, D

    2009-01-01

    The orthogonal matching pursuit (OMP) is a greedy algorithm to solve sparse approximation problems. Sufficient conditions for exact recovery are known with and without noise. In this paper we investigate the applicability of the OMP for the solution of ill-posed inverse problems in general, and in particular for two deconvolution examples from mass spectrometry and digital holography, respectively. In sparse approximation problems one often has to deal with the problem of redundancy of a dictionary, i.e. the atoms are not linearly independent. However, one expects them to be approximatively orthogonal and this is quantified by the so-called incoherence. This idea cannot be transferred to ill-posed inverse problems since here the atoms are typically far from orthogonal. The ill-posedness of the operator probably causes the correlation of two distinct atoms to become huge, i.e. that two atoms look much alike. Therefore, one needs conditions which take the structure of the problem into account and work without the concept of coherence. In this paper we develop results for the exact recovery of the support of noisy signals. In the two examples, mass spectrometry and digital holography, we show that our results lead to practically relevant estimates such that one may check a priori if the experimental setup guarantees exact deconvolution with OMP. Especially in the example from digital holography, our analysis may be regarded as a first step to calculate the resolution power of droplet holography

  13. An Improved Azimuth Angle Estimation Method with a Single Acoustic Vector Sensor Based on an Active Sonar Detection System.

    Science.gov (United States)

    Zhao, Anbang; Ma, Lin; Ma, Xuefei; Hui, Juan

    2017-02-20

    In this paper, an improved azimuth angle estimation method with a single acoustic vector sensor (AVS) is proposed based on matched filtering theory. The proposed method is mainly applied in an active sonar detection system. According to the conventional passive method based on complex acoustic intensity measurement, the mathematical and physical model of this proposed method is described in detail. The computer simulation and lake experiments results indicate that this method can realize the azimuth angle estimation with high precision by using only a single AVS. Compared with the conventional method, the proposed method achieves better estimation performance. Moreover, the proposed method does not require complex operations in frequencydomain and achieves computational complexity reduction.

  14. An Improved Azimuth Angle Estimation Method with a Single Acoustic Vector Sensor Based on an Active Sonar Detection System

    Directory of Open Access Journals (Sweden)

    Anbang Zhao

    2017-02-01

    Full Text Available In this paper, an improved azimuth angle estimation method with a single acoustic vector sensor (AVS is proposed based on matched filtering theory. The proposed method is mainly applied in an active sonar detection system. According to the conventional passive method based on complex acoustic intensity measurement, the mathematical and physical model of this proposed method is described in detail. The computer simulation and lake experiments results indicate that this method can realize the azimuth angle estimation with high precision by using only a single AVS. Compared with the conventional method, the proposed method achieves better estimation performance. Moreover, the proposed method does not require complex operations in frequencydomain and achieves computational complexity reduction.

  15. Experimental Results for Direction of Arrival Estimation with a Single Acoustic Vector Sensor in Shallow Water

    Directory of Open Access Journals (Sweden)

    Alper Bereketli

    2015-01-01

    Full Text Available We study the performances of several computationally efficient and simple techniques for estimating direction of arrival (DOA of an underwater acoustic source using a single acoustic vector sensor (AVS in shallow water. Underwater AVS is a compact device, which consists of one hydrophone and three accelerometers in a packaged form, measuring scalar pressure and three-dimensional acceleration simultaneously at a single position. A very controlled experimental setup is prepared to test how well-known techniques, namely, arctan-based, intensity-based, time domain beamforming, and frequency domain beamforming methods, perform in estimating DOA of a source in different circumstances. Experimental results reveal that for almost all cases beamforming techniques perform best. Moreover, arctan-based method, which is the simplest of all, provides satisfactory results for practical purposes.

  16. Cultural adaptations to the differential threats posed by hot versus cold climates.

    Science.gov (United States)

    Murray, Damian R

    2013-10-01

    Hot and cold climates have posed differential threats to human survival throughout history. Cold temperatures can pose direct threats to survival in themselves, whereas hot temperatures may pose threats indirectly through higher prevalence of infectious disease. These differential threats yield convergent predictions for the relationship between more demanding climates and freedom of expression, but divergent predictions for freedom from discrimination.

  17. Conceiving Human Interaction by Visualising Depth Data of Head Pose Changes and Emotion Recognition via Facial Expressions

    Directory of Open Access Journals (Sweden)

    Grigorios Kalliatakis

    2017-07-01

    Full Text Available Affective computing in general and human activity and intention analysis in particular comprise a rapidly-growing field of research. Head pose and emotion changes present serious challenges when applied to player’s training and ludology experience in serious games, or analysis of customer satisfaction regarding broadcast and web services, or monitoring a driver’s attention. Given the increasing prominence and utility of depth sensors, it is now feasible to perform large-scale collection of three-dimensional (3D data for subsequent analysis. Discriminative random regression forests were selected in order to rapidly and accurately estimate head pose changes in an unconstrained environment. In order to complete the secondary process of recognising four universal dominant facial expressions (happiness, anger, sadness and surprise, emotion recognition via facial expressions (ERFE was adopted. After that, a lightweight data exchange format (JavaScript Object Notation (JSON is employed, in order to manipulate the data extracted from the two aforementioned settings. Motivated by the need to generate comprehensible visual representations from different sets of data, in this paper, we introduce a system capable of monitoring human activity through head pose and emotion changes, utilising an affordable 3D sensing technology (Microsoft Kinect sensor.

  18. Problem Posing with Realistic Mathematics Education Approach in Geometry Learning

    Science.gov (United States)

    Mahendra, R.; Slamet, I.; Budiyono

    2017-09-01

    One of the difficulties of students in the learning of geometry is on the subject of plane that requires students to understand the abstract matter. The aim of this research is to determine the effect of Problem Posing learning model with Realistic Mathematics Education Approach in geometry learning. This quasi experimental research was conducted in one of the junior high schools in Karanganyar, Indonesia. The sample was taken using stratified cluster random sampling technique. The results of this research indicate that the model of Problem Posing learning with Realistic Mathematics Education Approach can improve students’ conceptual understanding significantly in geometry learning especially on plane topics. It is because students on the application of Problem Posing with Realistic Mathematics Education Approach are become to be active in constructing their knowledge, proposing, and problem solving in realistic, so it easier for students to understand concepts and solve the problems. Therefore, the model of Problem Posing learning with Realistic Mathematics Education Approach is appropriately applied in mathematics learning especially on geometry material. Furthermore, the impact can improve student achievement.

  19. Squeezeposenet: Image Based Pose Regression with Small Convolutional Neural Networks for Real Time Uas Navigation

    Science.gov (United States)

    Müller, M. S.; Urban, S.; Jutzi, B.

    2017-08-01

    The number of unmanned aerial vehicles (UAVs) is increasing since low-cost airborne systems are available for a wide range of users. The outdoor navigation of such vehicles is mostly based on global navigation satellite system (GNSS) methods to gain the vehicles trajectory. The drawback of satellite-based navigation are failures caused by occlusions and multi-path interferences. Beside this, local image-based solutions like Simultaneous Localization and Mapping (SLAM) and Visual Odometry (VO) can e.g. be used to support the GNSS solution by closing trajectory gaps but are computationally expensive. However, if the trajectory estimation is interrupted or not available a re-localization is mandatory. In this paper we will provide a novel method for a GNSS-free and fast image-based pose regression in a known area by utilizing a small convolutional neural network (CNN). With on-board processing in mind, we employ a lightweight CNN called SqueezeNet and use transfer learning to adapt the network to pose regression. Our experiments show promising results for GNSS-free and fast localization.

  20. Pose and Solve Varignon Converse Problems

    Science.gov (United States)

    Contreras, José N.

    2014-01-01

    The activity of posing and solving problems can enrich learners' mathematical experiences because it fosters a spirit of inquisitiveness, cultivates their mathematical curiosity, and deepens their views of what it means to do mathematics. To achieve these goals, a mathematical problem needs to be at the appropriate level of difficulty,…

  1. Gas hydrates and clathrates. Flow assurance, environmental and economic perspectives and the Nigerian liquefied natural gas project

    International Nuclear Information System (INIS)

    Gbaruko, B.C.; Igwe, J.C.; Nwokeoma, R.C.; Gbaruko, P.N.

    2007-01-01

    Gas hydrates are nonstoichiometric crystalline compounds that belong to the inclusion group known as clathrates. They occur when water molecules attach themselves together through hydrogen bonding and form cavities which can be occupied by a single gas or volatile liquid molecule. Gas hydrates, asphaltenes and waxes are three major threats to flow assurance that must be well assessed by design team uptime. Gas hydrates are also looked upon as a future energy source and as a potential climate hazard. The purpose of this review is to show the chemistry and mechanism of gas hydrate formation, the problems they pose, especially to flow assurance, their system implications, their environmental and economic perspectives with respect to their prospects as storage and transport alternative to the liquefied natural gas technology. (author)

  2. Estimates of the Spectral Aerosol Single Sea Scattering Albedo and Aerosol Radiative Effects during SAFARI 2000

    Science.gov (United States)

    Bergstrom, Robert W.; Pilewskie, Peter; Schmid, Beat; Russell, Philip B.

    2003-01-01

    Using measurements of the spectral solar radiative flux and optical depth for 2 days (24 August and 6 September 2000) during the SAFARI 2000 intensive field experiment and a detailed radiative transfer model, we estimate the spectral single scattering albedo of the aerosol layer. The single scattering albedo is similar on the 2 days even though the optical depth for the aerosol layer was quite different. The aerosol single scattering albedo was between 0.85 and 0.90 at 350 nm, decreasing to 0.6 in the near infrared. The magnitude and decrease with wavelength of the single scattering albedo are consistent with the absorption properties of small black carbon particles. We estimate the uncertainty in the single scattering albedo due to the uncertainty in the measured fractional absorption and optical depths. The uncertainty in the single scattering albedo is significantly less on the high-optical-depth day (6 September) than on the low-optical-depth day (24 August). On the high-optical-depth day, the uncertainty in the single scattering albedo is 0.02 in the midvisible whereas on the low-optical-depth day the uncertainty is 0.08 in the midvisible. On both days, the uncertainty becomes larger in the near infrared. We compute the radiative effect of the aerosol by comparing calculations with and without the aerosol. The effect at the top of the atmosphere (TOA) is to cool the atmosphere by 13 W/sq m on 24 August and 17 W/sq m on 6 September. The effect on the downward flux at the surface is a reduction of 57 W/sq m on 24 August and 200 W/sq m on 6 September. The aerosol effect on the downward flux at the surface is in good agreement with the results reported from the Indian Ocean Experiment (INDOEX).

  3. Categorization of questions posed before and after inquiry-based learning

    Directory of Open Access Journals (Sweden)

    Sandra Milena García González

    2014-07-01

    Full Text Available Posing research questions is the central ability of the scientific thought. This article examines the ability of sixth grade children to pose researchable questions before and after a three months’ work on a didactic sequence based on the inquiry school model. According to their purpose, the questions asked by children, after reading a text, were classified into researchable questions -susceptible to be empirically explored-, questions about a cause, and questions on a piece of data. The results show that the amount and the type of questions the students were able to pose during the intervention changed, from most of questions on data or information, to most of researchable questions, subsequently, the importance of designing teaching approaches to foster this ability was proved.

  4. Trans-Pacific ENSO teleconnections pose a correlated risk to global agriculture

    Science.gov (United States)

    Anderson, W. B.; Seager, R.; Cane, M. A.; Baethgen, W.

    2017-12-01

    The El Niño Southern Oscillation (ENSO) is a major source of interannual climate variability, particularly in the Pacific Basin. ENSO life-cycles tend to evolve over multiple years, as do the associated trans-Pacific ENSO teleconnections. This analysis, however, represents the first attempt to characterize the structure of the risk posed by ENSO to wheat, maize and soybean production across the Pacific Basin. Our results indicate that most ENSO teleconnections relevant for crop flowering seasons are the result of a single trans-Pacific circulation anomaly that develops in boreal summer and persists through the spring. During the late summer and early fall of a developing ENSO event, the tropical Pacific forces an atmospheric anomaly in the midlatitudes that spans the Pacific Basin. This teleconnection directly links the soybean and maize growing seasons of the US, Mexico and China. It also connects the wheat growing seasons of Argentina, southern Brazil and Australia. The ENSO event peaks in boreal winter, when the atmospheric circulation anomalies intensify and affect maize and soybeans in southeast South America. As the event decays, the ENSO-induced circulation anomalies persist through the wheat flowering seasons in China and the US. While the prospect of ENSO forcing simultaneous droughts in major food producing regions seems disastrous, there may be a silver lining from the perspective of global food security: trans-Pacific ENSO teleconnections to yields are often offsetting between major producing regions in the eastern and western portions of the Pacific Basin. El Niños tend to create good maize and soybean growing conditions in the US and southeast South America, but poor growing conditions in China, Mexico and northeast Brazil. The opposite is true during La Niña. Wheat growing conditions in southeast South America generally have the opposite sign of those in Australia. Finally, we investigate how trade networks interact with this structure of ENSO

  5. Camelid Single-Domain Antibodies: Historical Perspective and Future Outlook

    Directory of Open Access Journals (Sweden)

    Mehdi Arbabi-Ghahroudi

    2017-11-01

    Full Text Available Tremendous effort has been expended over the past two and a half decades to understand many aspects of camelid heavy chain antibodies, from their biology, evolution, and immunogenetics to their potential applications in various fields of research and medicine. In this article, I present a historical perspective on the development of camelid single-domain antibodies (sdAbs or VHHs, also widely known as nanobodies since their discovery and discuss the advantages and disadvantages of these unique molecules in various areas of research, industry, and medicine. Commercialization of camelid sdAbs exploded in 2001 with a flurry of patents issued to the Vrije Universiteit Brussel (VUB and later taken on by the Vlaams Interuniversitair Instituut voor Biotechnologie (VIB and, after 2002, the VIB-founded spin-off company, Ablynx. While entrepreneurial spirit has certainly catalyzed the exploration of nanobodies as marketable products, IP restrictions may be partially responsible for the relatively long time span between the discovery of these biomolecules and their entry into the pharmaceutical market. It is now anticipated that the first VHH-based antibody drug, Caplacizumab, a bivalent anti-vWF antibody for treating rare blood clotting disorders, may be approved and commercialized in 2018 or shortly thereafter. This elusive first approval, along with the expiry of key patents, may substantially alter the scientific and biomedical landscape surrounding camelid sdAbs and pave the way for their emergence as mainstream biotherapeutics.

  6. Fast Kalman Filtering for Relative Spacecraft Position and Attitude Estimation for the Raven ISS Hosted Payload

    Science.gov (United States)

    Galante, Joseph M.; Van Eepoel, John; D'Souza, Chris; Patrick, Bryan

    2016-01-01

    The Raven ISS Hosted Payload will feature several pose measurement sensors on a pan/tilt gimbal which will be used to autonomously track resupply vehicles as they approach and depart the International Space Station. This paper discusses the derivation of a Relative Navigation Filter (RNF) to fuse measurements from the different pose measurement sensors to produce relative position and attitude estimates. The RNF relies on relative translation and orientation kinematics and careful pose sensor modeling to eliminate dependence on orbital position information and associated orbital dynamics models. The filter state is augmented with sensor biases to provide a mechanism for the filter to estimate and mitigate the offset between the measurements from different pose sensors

  7. A residual-based a posteriori error estimator for single-phase Darcy flow in fractured porous media

    KAUST Repository

    Chen, Huangxin

    2016-12-09

    In this paper we develop an a posteriori error estimator for a mixed finite element method for single-phase Darcy flow in a two-dimensional fractured porous media. The discrete fracture model is applied to model the fractures by one-dimensional fractures in a two-dimensional domain. We consider Raviart–Thomas mixed finite element method for the approximation of the coupled Darcy flows in the fractures and the surrounding porous media. We derive a robust residual-based a posteriori error estimator for the problem with non-intersecting fractures. The reliability and efficiency of the a posteriori error estimator are established for the error measured in an energy norm. Numerical results verifying the robustness of the proposed a posteriori error estimator are given. Moreover, our numerical results indicate that the a posteriori error estimator also works well for the problem with intersecting fractures.

  8. Retrieval of LAI and leaf chlorophyll content from remote sensing data by agronomy mechanism knowledge to solve the ill-posed inverse problem

    Science.gov (United States)

    Li, Zhenhai; Nie, Chenwei; Yang, Guijun; Xu, Xingang; Jin, Xiuliang; Gu, Xiaohe

    2014-10-01

    Leaf area index (LAI) and LCC, as the two most important crop growth variables, are major considerations in management decisions, agricultural planning and policy making. Estimation of canopy biophysical variables from remote sensing data was investigated using a radiative transfer model. However, the ill-posed problem is unavoidable for the unique solution of the inverse problem and the uncertainty of measurements and model assumptions. This study focused on the use of agronomy mechanism knowledge to restrict and remove the ill-posed inversion results. For this purpose, the inversion results obtained using the PROSAIL model alone (NAMK) and linked with agronomic mechanism knowledge (AMK) were compared. The results showed that AMK did not significantly improve the accuracy of LAI inversion. LAI was estimated with high accuracy, and there was no significant improvement after considering AMK. The validation results of the determination coefficient (R2) and the corresponding root mean square error (RMSE) between measured LAI and estimated LAI were 0.635 and 1.022 for NAMK, and 0.637 and 0.999 for AMK, respectively. LCC estimation was significantly improved with agronomy mechanism knowledge; the R2 and RMSE values were 0.377 and 14.495 μg cm-2 for NAMK, and 0.503 and 10.661 μg cm-2 for AMK, respectively. Results of the comparison demonstrated the need for agronomy mechanism knowledge in radiative transfer model inversion.

  9. Application of Shape Similarity in Pose Selection and Virtual Screening in CSARdock2014 Exercise.

    Science.gov (United States)

    Kumar, Ashutosh; Zhang, Kam Y J

    2016-06-27

    To evaluate the applicability of shape similarity in docking-based pose selection and virtual screening, we participated in the CSARdock2014 benchmark exercise for identifying the correct docking pose of inhibitors targeting factor XA, spleen tyrosine kinase, and tRNA methyltransferase. This exercise provides a valuable opportunity for researchers to test their docking programs, methods, and protocols in a blind testing environment. In the CSARdock2014 benchmark exercise, we have implemented an approach that uses ligand 3D shape similarity to facilitate docking-based pose selection and virtual screening. We showed here that ligand 3D shape similarity between bound poses could be used to identify the native-like pose from an ensemble of docking-generated poses. Our method correctly identified the native pose as the top-ranking pose for 73% of test cases in a blind testing environment. Moreover, the pose selection results also revealed an excellent correlation between ligand 3D shape similarity scores and RMSD to X-ray crystal structure ligand. In the virtual screening exercise, the average RMSD for our pose prediction was found to be 1.02 Å, and it was one of the top performances achieved in CSARdock2014 benchmark exercise. Furthermore, the inclusion of shape similarity improved virtual screening performance of docking-based scoring and ranking. The coefficient of determination (r(2)) between experimental activities and docking scores for 276 spleen tyrosine kinase inhibitors was found to be 0.365 but reached 0.614 when the ligand 3D shape similarity was included.

  10. Remote-controlled flexible pose measurement system and method for a moving target in wind tunnel

    Directory of Open Access Journals (Sweden)

    Wei LIU

    2018-01-01

    Full Text Available The measurement of position and attitude parameters for the isolated target from a high-speed aircraft is a great challenge in the field of wind tunnel simulation technology. This paper proposes a remote-controlled flexible pose measurement system in wind tunnel conditions for the separation of a target from an aircraft. The position and attitude parameters of a moving object are obtained by utilizing a single camera with a focal length and camera orientation that can be changed based on different measurement conditions. Using this proposed system and method, both the flexibility and efficiency of the pose measurement system can be enhanced in wind tunnel conditions to meet the measurement requirements of different objects and experiments, which is also useful for the development of an intelligent position and attitude measurement system. The position and the focal length of the camera also can be controlled remotely during measurements to enlarge both the vertical and horizontal measurement range of this system. Experiments are conducted in the laboratory to measure the position and attitude of moving objects with high flexibility and efficiency, and the measurement precision of the measurement system is also verified through experiments.

  11. Model calibration and parameter estimation for environmental and water resource systems

    CERN Document Server

    Sun, Ne-Zheng

    2015-01-01

    This three-part book provides a comprehensive and systematic introduction to the development of useful models for complex systems. Part 1 covers the classical inverse problem for parameter estimation in both deterministic and statistical frameworks, Part 2 is dedicated to system identification, hyperparameter estimation, and model dimension reduction, and Part 3 considers how to collect data and construct reliable models for prediction and decision-making. For the first time, topics such as multiscale inversion, stochastic field parameterization, level set method, machine learning, global sensitivity analysis, data assimilation, model uncertainty quantification, robust design, and goal-oriented modeling, are systematically described and summarized in a single book from the perspective of model inversion, and elucidated with numerical examples from environmental and water resources modeling. Readers of this book will not only learn basic concepts and methods for simple parameter estimation, but also get famili...

  12. Updated Drainable Interstitial Liquid Volume Estimates for 119 Single Shell Tanks (SST) Declared Stabilized

    International Nuclear Information System (INIS)

    FIELD, J.G.

    2000-01-01

    This document assesses the volume of drainable interstitial liquid (DIL) and pumpable liquid remaining in 119 single-shell tanks (SSTs) that were previously stabilized. Based on the methodology and assumptions presented, the DIL exceeded the stabilization criterion of less than 50,000 gal in two of the 119 SSTs. Tank 241-C-102 had an estimated DIL of 62,000 gal, and the estimated DIL for tank 241-BY-103 was 58,000 gal. In addition, tanks 241-BX-103, 241-T-102, and 241-T-112 appear to exceed the stabilization criterion of 5,000 gal supernatant. An assessment of the source of the supernatant in these tanks is beyond the scope of this document. The actual DIL and pumpable liquid remaining volumes for each tank may vary significantly from estimated volumes as a result of specific tank waste characteristics that are not currently measured or defined. Further refinement to the pumpable liquid and DIL volume estimates may be needed as additional tank waste information is obtained

  13. Estimation of technetium 99m mercaptoacetyltriglycine plasma clearance by use of one single plasma sample

    International Nuclear Information System (INIS)

    Mueller-Suur, R.; Magnusson, G.; Karolinska Inst., Stockholm; Bois-Svensson, I.; Jansson, B.

    1991-01-01

    Recent studies have shown that technetium 99m mercaptoacetyltriglycine (MAG-3) is a suitable replacement for iodine 131 or 123 hippurate in gamma-camera renography. Also, the determination of its clearance is of value, since it correlates well with that of hippurate and thus may be an indirect measure of renal plasma flow. In order to simplify the clearance method we developed formulas for the estimation of plasma clearance of MAG-3 based on a single plasma sample and compared them with the multiple sample method based on 7 plasma samples. The correlation to effective renal plasma flow (ERPF) (according to Tauxe's method, using iodine 123 hippurate), which ranged from 75 to 654 ml/min per 1.73 m 2 , was determined in these patients. Using the developed regression equations the error of estimate for the simplified clearance method was acceptably low (18-14 ml/min), when the single plasma sample was taken 44-64 min post-injection. Formulas for different sampling times at 44, 48, 52, 56, 60 and 64 min are given, and we recommend 60 min as optimal, with an error of estimate of 15.5 ml/min. The correlation between the MAG-3 clearances and ERPF was high (r=0.90). Since normal values for MAG-3 clearance are not yet available, transformation to estimated ERPF values by the regression equation (ERPF=1.86xC MAG-3 +4.6) could be of clinical value in order to compare it with the normal values for ERPF given in the literature. (orig.)

  14. The effects of single bit quantization on direction of arrival estimation of UHF RFID tags

    NARCIS (Netherlands)

    Huiting, J.; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria

    2016-01-01

    Phased arrays can be used to estimate the direction-of-arrival (DOA) of UHF RFID tags. To save on energy consumption and hardware costs, in this paper we explore the possibility of using single bit analog-to-digital converters for our phased array setup. This setup consists of an off-the-shelf

  15. Enhancing students’ mathematical problem posing skill through writing in performance tasks strategy

    Science.gov (United States)

    Kadir; Adelina, R.; Fatma, M.

    2018-01-01

    Many researchers have studied the Writing in Performance Task (WiPT) strategy in learning, but only a few paid attention on its relation to the problem-posing skill in mathematics. The problem-posing skill in mathematics covers problem reformulation, reconstruction, and imitation. The purpose of the present study was to examine the effect of WiPT strategy on students’ mathematical problem-posing skill. The research was conducted at a Public Junior Secondary School in Tangerang Selatan. It used a quasi-experimental method with randomized control group post-test. The samples were 64 students consists of 32 students of the experiment group and 32 students of the control. A cluster random sampling technique was used for sampling. The research data were obtained by testing. The research shows that the problem-posing skill of students taught by WiPT strategy is higher than students taught by a conventional strategy. The research concludes that the WiPT strategy is more effective in enhancing the students’ mathematical problem-posing skill compared to the conventional strategy.

  16. Molecular magnetism, status and perspectives

    Science.gov (United States)

    Gatteschi, Dante; Bogani, Lapo; Cornia, Andrea; Mannini, Matteo; Sorace, Lorenzo; Sessoli, Roberta

    2008-12-01

    A short review is made of molecular magnetism, trying to discuss what is alive and well, with perspectives for the future. All the main fields of activity are mentioned, ranging from the so-called spin cross-over systems to the quest for organic (molecular) ferromagnets. Particular attention is devoted to some of the recent advances in these fields, highlighting also the opportunities for the development of applications. Low dimensional magnets are perhaps the best opportunity to use molecules, and the status of single-molecule and single chain magnets is discussed. The last part is devoted to the organization of magnetic molecules and to the development of techniques which allow to measure the magnetic properties of thin layers and, in perspective, of single molecules.

  17. Economic evaluations of occupational health interventions from a company's perspective: A systematic review of methods to estimate the cost of health-related productivity loss

    NARCIS (Netherlands)

    Uegaki, K.; Bruijne, M.C. de; Beek, A.J. van der; Mechelen, W. van; Tulder, M.W. van

    2011-01-01

    Objectives: To investigate the methods used to estimate the indirect costs of health-related productivity in economic evaluations from a company's perspective. Methods: The primary literature search was conducted in Medline and Embase. Supplemental searches were conducted in the Cochrane NHS

  18. Perspectives of Single-Wall Carbon Nano-tube Production in the Arc Discharge Process

    International Nuclear Information System (INIS)

    Krestinin, A.V.; Kiselev, N.A.; Raevskii, A.V; Ryabenko, A.G.; Zakharov, D.N.; Zvereva, G.I.

    2003-01-01

    Single-wall carbon nano tubes (SWNTs) promise wide applications in many technical fields. As a result purified SWNT material is sold now on the West market at more than 1000 dollars per 1 gram. Thus developing an effective technology for SWNTs production rises to a very important sintofene problem. The perspectives of three existing methods providing raw material in the technology of SWNT production have been analyzed. They are i) pulsed laser evaporation of graphite/metal composites, ii) evaporation of graphite electrodes with metal content in the are discharge process, and iii) catalytic decomposition of the mixture of CO and metal carbonyl catalyst precursor. The observed dynamites of SWNT market points to replacing the laser method of SWNTs production by the are process. The conclusion has been made that the technology based on the are process will be the major one for the fabrication of purified SWNTs at least for the next five years. A reliable estimation of a low price limit of SWNTs was derived from a comparison of two technologies based on the are discharge process: the first one is the production of SWNTs and the second one is the production of a fullerene mixture C 6 0 + C 7 0. The main conclusion was made that the price of purified SWNTs should always be more by 2-3 times the price of fullerene mixture. The parameters of a lab-scale technology for the production of purified SWNTs are listed. A large-scale application of the developed technology is expected to reduce the price of purified SWNTs by approximately ten times. The methods now employed for the characterization of products containing SWNTs are briefly observed. It is concluded that electron microscopy, thermogravimetric analysis, absorption and Raman spectroscopy, measurement of the specific surface aria, optical microscopy - each in separation is not enough for extensive characterization of a sample containing SWNTs, and all these methods should be used together. (author)

  19. Noise Estimation for Single-Slice Sinogram of Low-Dose X-Ray Computed Tomography Using Homogenous Patch

    Directory of Open Access Journals (Sweden)

    Zhiwu Liao

    2012-01-01

    Full Text Available We present a new method to estimate noise for a single-slice sinogram of low-dose CT based on the homogenous patches centered at a special pixel, called center point, which has the smallest variance among all sinogram pixels. The homogenous patch, composed by homogenous points, is formed by the points similar to the center point using similarity sorting, similarity decreasing searching, and variance analysis in a very large neighborhood (VLN to avoid manual selection of parameter for similarity measures.Homogenous pixels in the VLN allow us find the largest number of samples, who have the highest similarities to the center point, for noise estimation, and the noise level can be estimated according to unbiased estimation.Experimental results show that for the simulated noisy sinograms, the method proposed in this paper can obtain satisfied noise estimation results, especially for sinograms with relatively serious noises.

  20. Laser cost experience and estimation

    International Nuclear Information System (INIS)

    Shofner, F.M.; Hoglund, R.L.

    1977-01-01

    This report addresses the question of estimating the capital and operating costs for LIS (Laser Isotope Separation) lasers, which have performance requirements well beyond the state of mature art. This question is seen with different perspectives by political leaders, ERDA administrators, scientists, and engineers concerned with reducing LIS to economically successful commercial practice, on a timely basis. Accordingly, this report attempts to provide ''ballpark'' estimators for capital and operating costs and useful design and operating information for lasers based on mature technology, and their LIS analogs. It is written very basically and is intended to respond about equally to the perspectives of administrators, scientists, and engineers. Its major contributions are establishing the current, mature, industrialized laser track record (including capital and operating cost estimators, reliability, types of application, etc.) and, especially, evolution of generalized estimating procedures for capital and operating cost estimators for new laser design

  1. Teachers Implementing Mathematical Problem Posing in the Classroom: Challenges and Strategies

    Science.gov (United States)

    Leung, Shuk-kwan S.

    2013-01-01

    This paper reports a study about how a teacher educator shared knowledge with teachers when they worked together to implement mathematical problem posing (MPP) in the classroom. It includes feasible methods for getting practitioners to use research-based tasks aligned to the curriculum in order to encourage children to pose mathematical problems.…

  2. ?You?re dealing with an emotionally charged individual??: an industry perspective on the challenges posed by medical tourists? informal caregiver-companions

    OpenAIRE

    Casey, Victoria; Crooks, Valorie A; Snyder, Jeremy; Turner, Leigh

    2013-01-01

    Background Patients engage in medical tourism when they privately obtain a medical care abroad. Previous research shows that many medical tourists travel abroad with friends and family members who provide support and assistance. Meanwhile, very little is known about this important stakeholder group, referred to here as caregiver-companions. In this article we examine the challenges that can be posed by caregiver-companions and the overall practice of informal caregiving in medical tourism ...

  3. Wegner estimate and localization for alloy-type models with sign-changing exponentially decaying single-site potentials

    Science.gov (United States)

    Leonhardt, Karsten; Peyerimhoff, Norbert; Tautenhahn, Martin; Veselić, Ivan

    2015-05-01

    We study Schrödinger operators on L2(ℝd) and ℓ2(ℤd) with a random potential of alloy-type. The single-site potential is assumed to be exponentially decaying but not necessarily of fixed sign. In the continuum setting, we require a generalized step-function shape. Wegner estimates are bounds on the average number of eigenvalues in an energy interval of finite box restrictions of these types of operators. In the described situation, a Wegner estimate, which is polynomial in the volume of the box and linear in the size of the energy interval, holds. We apply the established Wegner estimate as an ingredient for a localization proof via multiscale analysis.

  4. Consistent Estimation of Pricing Kernels from Noisy Price Data

    OpenAIRE

    Vladislav Kargin

    2003-01-01

    If pricing kernels are assumed non-negative then the inverse problem of finding the pricing kernel is well-posed. The constrained least squares method provides a consistent estimate of the pricing kernel. When the data are limited, a new method is suggested: relaxed maximization of the relative entropy. This estimator is also consistent. Keywords: $\\epsilon$-entropy, non-parametric estimation, pricing kernel, inverse problems.

  5. The Use of Articles in L2 English: A Phraseological Perspective

    Science.gov (United States)

    Lesniewska, Justyna

    2016-01-01

    While it is a well-known fact that speakers of article-less mother tongues, such as Polish, experience problems with articles in English, this study seeks to investigate the problem from a different perspective. Namely, it poses the question of whether the correct use of the article system of the L2 is indeed a purely grammatical task (as it is…

  6. Teaching Human Poses Interactively to a Social Robot

    Science.gov (United States)

    Gonzalez-Pacheco, Victor; Malfaz, Maria; Fernandez, Fernando; Salichs, Miguel A.

    2013-01-01

    The main activity of social robots is to interact with people. In order to do that, the robot must be able to understand what the user is saying or doing. Typically, this capability consists of pre-programmed behaviors or is acquired through controlled learning processes, which are executed before the social interaction begins. This paper presents a software architecture that enables a robot to learn poses in a similar way as people do. That is, hearing its teacher's explanations and acquiring new knowledge in real time. The architecture leans on two main components: an RGB-D (Red-, Green-, Blue- Depth) -based visual system, which gathers the user examples, and an Automatic Speech Recognition (ASR) system, which processes the speech describing those examples. The robot is able to naturally learn the poses the teacher is showing to it by maintaining a natural interaction with the teacher. We evaluate our system with 24 users who teach the robot a predetermined set of poses. The experimental results show that, with a few training examples, the system reaches high accuracy and robustness. This method shows how to combine data from the visual and auditory systems for the acquisition of new knowledge in a natural manner. Such a natural way of training enables robots to learn from users, even if they are not experts in robotics. PMID:24048336

  7. Teaching Human Poses Interactively to a Social Robot

    Directory of Open Access Journals (Sweden)

    Miguel A. Salichs

    2013-09-01

    Full Text Available The main activity of social robots is to interact with people. In order to do that, the robot must be able to understand what the user is saying or doing. Typically, this capability consists of pre-programmed behaviors or is acquired through controlled learning processes, which are executed before the social interaction begins. This paper presents a software architecture that enables a robot to learn poses in a similar way as people do. That is, hearing its teacher’s explanations and acquiring new knowledge in real time. The architecture leans on two main components: an RGB-D (Red-, Green-, Blue- Depth -based visual system, which gathers the user examples, and an Automatic Speech Recognition (ASR system, which processes the speech describing those examples. The robot is able to naturally learn the poses the teacher is showing to it by maintaining a natural interaction with the teacher. We evaluate our system with 24 users who teach the robot a predetermined set of poses. The experimental results show that, with a few training examples, the system reaches high accuracy and robustness. This method shows how to combine data from the visual and auditory systems for the acquisition of new knowledge in a natural manner. Such a natural way of training enables robots to learn from users, even if they are not experts in robotics.

  8. An Investigation of Eighth Grade Students' Problem Posing Skills (Turkey Sample)

    Science.gov (United States)

    Arikan, Elif Esra; Ünal, Hasan

    2015-01-01

    To pose a problem refers to the creative activity for mathematics education. The purpose of the study was to explore the eighth grade students' problem posing ability. Three learning domains such as requiring four operations, fractions and geometry were chosen for this reason. There were two classes which were coded as class A and class B. Class A…

  9. Analyzing Pre-Service Primary Teachers' Fraction Knowledge Structures through Problem Posing

    Science.gov (United States)

    Kilic, Cigdem

    2015-01-01

    In this study it was aimed to determine pre-service primary teachers' knowledge structures of fraction through problem posing activities. A total of 90 pre-service primary teachers participated in this study. A problem posing test consisting of two questions was used and the participants were asked to generate as many as problems based on the…

  10. Single neuron computation

    CERN Document Server

    McKenna, Thomas M; Zornetzer, Steven F

    1992-01-01

    This book contains twenty-two original contributions that provide a comprehensive overview of computational approaches to understanding a single neuron structure. The focus on cellular-level processes is twofold. From a computational neuroscience perspective, a thorough understanding of the information processing performed by single neurons leads to an understanding of circuit- and systems-level activity. From the standpoint of artificial neural networks (ANNs), a single real neuron is as complex an operational unit as an entire ANN, and formalizing the complex computations performed by real n

  11. Using physics-based pose predictions and free energy perturbation calculations to predict binding poses and relative binding affinities for FXR ligands in the D3R Grand Challenge 2

    Science.gov (United States)

    Athanasiou, Christina; Vasilakaki, Sofia; Dellis, Dimitris; Cournia, Zoe

    2018-01-01

    Computer-aided drug design has become an integral part of drug discovery and development in the pharmaceutical and biotechnology industry, and is nowadays extensively used in the lead identification and lead optimization phases. The drug design data resource (D3R) organizes challenges against blinded experimental data to prospectively test computational methodologies as an opportunity for improved methods and algorithms to emerge. We participated in Grand Challenge 2 to predict the crystallographic poses of 36 Farnesoid X Receptor (FXR)-bound ligands and the relative binding affinities for two designated subsets of 18 and 15 FXR-bound ligands. Here, we present our methodology for pose and affinity predictions and its evaluation after the release of the experimental data. For predicting the crystallographic poses, we used docking and physics-based pose prediction methods guided by the binding poses of native ligands. For FXR ligands with known chemotypes in the PDB, we accurately predicted their binding modes, while for those with unknown chemotypes the predictions were more challenging. Our group ranked #1st (based on the median RMSD) out of 46 groups, which submitted complete entries for the binding pose prediction challenge. For the relative binding affinity prediction challenge, we performed free energy perturbation (FEP) calculations coupled with molecular dynamics (MD) simulations. FEP/MD calculations displayed a high success rate in identifying compounds with better or worse binding affinity than the reference (parent) compound. Our studies suggest that when ligands with chemical precedent are available in the literature, binding pose predictions using docking and physics-based methods are reliable; however, predictions are challenging for ligands with completely unknown chemotypes. We also show that FEP/MD calculations hold predictive value and can nowadays be used in a high throughput mode in a lead optimization project provided that crystal structures of

  12. Improving attitudes toward mathematics learning with problem posing in class VIII

    Science.gov (United States)

    Vionita, Alfha; Purboningsih, Dyah

    2017-08-01

    This research is classroom action research which is collaborated to improve student's behavior toward math and mathematics learning at class VIII by using problem posing approach. The subject of research is all of students grade VIIIA which consist of 32 students. This research has been held on two period, first period is about 3 times meeting, and second period is about 4 times meeting. The instrument of this research is implementation of learning observation's guidance by using problem posing approach. Cycle test has been used to measure cognitive competence, and questionnaire to measure the students' behavior in mathematics learning process. The result of research shows the students' behavior has been improving after using problem posing approach. It is showed by the behavior's criteria of students that has increasing result from the average in first period to high in second period. Furthermore, the percentage of test result is also improve from 68,75% in first period to 78,13% in second period. On the other hand, the implementation of learning observation by using problem posing approach has also improving and it is showed by the average percentage of teacher's achievement in first period is 89,2% and student's achievement 85,8%. These results get increase in second period for both teacher and students' achievement which are 94,4% and 91,11%. As a result, students' behavior toward math learning process in class VIII has been improving by using problem posing approach.

  13. Measuring Single Event Upsets in the ATLAS Inner Tracker

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    When the HL-LHC starts collecting data, the electronics inside will be subject to massive amounts of radiation. As a result, single event upsets could pose a threat to the ATLAS readout chain. The ABC130, a prototype front-end ASIC for the ATLAS inner tracker, must be tested for its susceptibility to single event upsets.

  14. CC-MUSIC: An Optimization Estimator for Mutual Coupling Correction of L-Shaped Nonuniform Array with Single Snapshot

    Directory of Open Access Journals (Sweden)

    Yuguan Hou

    2015-01-01

    Full Text Available For the case of the single snapshot, the integrated SNR gain could not be obtained without the multiple snapshots, which degrades the mutual coupling correction performance under the lower SNR case. In this paper, a Convex Chain MUSIC (CC-MUSIC algorithm is proposed for the mutual coupling correction of the L-shaped nonuniform array with single snapshot. It is an online self-calibration algorithm and does not require the prior knowledge of the correction matrix initialization and the calibration source with the known position. An optimization for the approximation between the no mutual coupling covariance matrix without the interpolated transformation and the covariance matrix with the mutual coupling and the interpolated transformation is derived. A global optimization problem is formed for the mutual coupling correction and the spatial spectrum estimation. Furthermore, the nonconvex optimization problem of this global optimization is transformed as a chain of the convex optimization, which is basically an alternating optimization routine. The simulation results demonstrate the effectiveness of the proposed method, which improve the resolution ability and the estimation accuracy of the multisources with the single snapshot.

  15. Yoga Poses Increase Subjective Energy and State Self-Esteem in Comparison to ‘Power Poses’

    Directory of Open Access Journals (Sweden)

    Agnieszka Golec de Zavala

    2017-05-01

    Full Text Available Research on beneficial consequences of yoga focuses on the effects of yogic breathing and meditation. Less is known about the psychological effects of performing yoga postures. The present study investigated the effects of yoga poses on subjective sense of energy and self-esteem. The effects of yoga postures were compared to the effects of ‘power poses,’ which arguably increase the sense of power and self-confidence due to their association with interpersonal dominance (Carney et al., 2010. The study tested the novel prediction that yoga poses, which are not associated with interpersonal dominance but increase bodily energy, would increase the subjective feeling of energy and therefore increase self-esteem compared to ‘high power’ and ‘low power’ poses. A two factorial, between participants design was employed. Participants performed either two standing yoga poses with open front of the body (n = 19, two standing yoga poses with covered front of the body (n = 22, two expansive, high power poses (n = 21, or two constrictive, low power poses (n = 20 for 1-min each. The results showed that yoga poses in comparison to ‘power poses’ increased self-esteem. This effect was mediated by an increased subjective sense of energy and was observed when baseline trait self-esteem was controlled for. These results suggest that the effects of performing open, expansive body postures may be driven by processes other than the poses’ association with interpersonal power and dominance. This study demonstrates that positive effects of yoga practice can occur after performing yoga poses for only 2 min.

  16. Ant-inspired density estimation via random walks.

    Science.gov (United States)

    Musco, Cameron; Su, Hsin-Hao; Lynch, Nancy A

    2017-10-03

    Many ant species use distributed population density estimation in applications ranging from quorum sensing, to task allocation, to appraisal of enemy colony strength. It has been shown that ants estimate local population density by tracking encounter rates: The higher the density, the more often the ants bump into each other. We study distributed density estimation from a theoretical perspective. We prove that a group of anonymous agents randomly walking on a grid are able to estimate their density within a small multiplicative error in few steps by measuring their rates of encounter with other agents. Despite dependencies inherent in the fact that nearby agents may collide repeatedly (and, worse, cannot recognize when this happens), our bound nearly matches what would be required to estimate density by independently sampling grid locations. From a biological perspective, our work helps shed light on how ants and other social insects can obtain relatively accurate density estimates via encounter rates. From a technical perspective, our analysis provides tools for understanding complex dependencies in the collision probabilities of multiple random walks. We bound the strength of these dependencies using local mixing properties of the underlying graph. Our results extend beyond the grid to more general graphs, and we discuss applications to size estimation for social networks, density estimation for robot swarms, and random walk-based sampling for sensor networks.

  17. Lead and Cadmium: Priorities for action from UNEP’s perspective for addressing risks posed by these two heavy metals

    Directory of Open Access Journals (Sweden)

    Piper D.

    2013-04-01

    Full Text Available The United Nations Environment Programme (UNEP has been focusing on actions with regard to lead and cadmium since 2001 when the work of the Partnership for Clean Fuels and Vehicles (PCFV was initiated. The development and finalization of the reviews of scientific information on lead and cadmium facilitated discussions among Governments in relation to the need for global action with regard to these heavy metals. UNEP continues to address priority areas for focusing to reduce risks posed by lead and cadmium. The Global Alliance to Eliminate Lead Paint (GAELP is a clear example for addressing those risks; however more work is expected to be done in relation to these key issues.

  18. Estimation of wave directional spreading in shallow water

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Deo, M.C.; Anand, N.M.; Chandramohan, P.

    loads on offshore structures, long- term estimation of waves and estimation of sediment transport. According to the principle of superposition of linear waves, the sea state is com- posed of a large number of individual wave components, each having a..., who were involved in the data collection programme. NIO Contribution number 2569. References Benoit, M., 1992. Practical comparative performance survey of methods used for estimating directional wave spectra from heave–pitch–roll data. Proceedings...

  19. Estimating the burden of antimicrobial resistance: a systematic literature review.

    Science.gov (United States)

    Naylor, Nichola R; Atun, Rifat; Zhu, Nina; Kulasabanathan, Kavian; Silva, Sachin; Chatterjee, Anuja; Knight, Gwenan M; Robotham, Julie V

    2018-01-01

    Accurate estimates of the burden of antimicrobial resistance (AMR) are needed to establish the magnitude of this global threat in terms of both health and cost, and to paramaterise cost-effectiveness evaluations of interventions aiming to tackle the problem. This review aimed to establish the alternative methodologies used in estimating AMR burden in order to appraise the current evidence base. MEDLINE, EMBASE, Scopus, EconLit, PubMed and grey literature were searched. English language studies evaluating the impact of AMR (from any microbe) on patient, payer/provider and economic burden published between January 2013 and December 2015 were included. Independent screening of title/abstracts followed by full texts was performed using pre-specified criteria. A study quality score (from zero to one) was derived using Newcastle-Ottawa and Philips checklists. Extracted study data were used to compare study method and resulting burden estimate, according to perspective. Monetary costs were converted into 2013 USD. Out of 5187 unique retrievals, 214 studies were included. One hundred eighty-seven studies estimated patient health, 75 studies estimated payer/provider and 11 studies estimated economic burden. 64% of included studies were single centre. The majority of studies estimating patient or provider/payer burden used regression techniques. 48% of studies estimating mortality burden found a significant impact from resistance, excess healthcare system costs ranged from non-significance to $1 billion per year, whilst economic burden ranged from $21,832 per case to over $3 trillion in GDP loss. Median quality scores (interquartile range) for patient, payer/provider and economic burden studies were 0.67 (0.56-0.67), 0.56 (0.46-0.67) and 0.53 (0.44-0.60) respectively. This study highlights what methodological assumptions and biases can occur dependent on chosen outcome and perspective. Currently, there is considerable variability in burden estimates, which can lead in

  20. Performance of a procedure for yield estimation in fruit orchards

    DEFF Research Database (Denmark)

    Aravena Zamora, Felipe; Potin, Camila; Wulfsohn, Dvora-Laio

    Early estimation of expected fruit tree yield is important for the market planning and for growers and exporters to plan for labour and boxes. Large variations in tree yield may be found, posing a challenge for accurate yield estimation. We evaluated a multilevel systematic sampling procedure...

  1. Multispectral embedding-based deep neural network for three-dimensional human pose recovery

    Science.gov (United States)

    Yu, Jialin; Sun, Jifeng

    2018-01-01

    Monocular image-based three-dimensional (3-D) human pose recovery aims to retrieve 3-D poses using the corresponding two-dimensional image features. Therefore, the pose recovery performance highly depends on the image representations. We propose a multispectral embedding-based deep neural network (MSEDNN) to automatically obtain the most discriminative features from multiple deep convolutional neural networks and then embed their penultimate fully connected layers into a low-dimensional manifold. This compact manifold can explore not only the optimum output from multiple deep networks but also the complementary properties of them. Furthermore, the distribution of each hierarchy discriminative manifold is sufficiently smooth so that the training process of our MSEDNN can be effectively implemented only using few labeled data. Our proposed network contains a body joint detector and a human pose regressor that are jointly trained. Extensive experiments conducted on four databases show that our proposed MSEDNN can achieve the best recovery performance compared with the state-of-the-art methods.

  2. Optimal Estimation of Diffusion Coefficients from Noisy Time-Lapse-Recorded Single-Particle Trajectories

    DEFF Research Database (Denmark)

    Vestergaard, Christian Lyngby

    2012-01-01

    . The standard method for estimating diusion coecients from single-particle trajectories is based on leastsquares tting to the experimentally measured mean square displacements. This method is highly inecient, since it ignores the high correlations inherent in these. We derive the exact maximum likelihood...... of diusion coecients of hOgg1 repair proteins diusing on stretched uctuating DNA from data previously analyzed using a suboptimal method. Our analysis shows that the proteins have dierent eective diusion coecients and that their diusion coecients are correlated with their residence time on DNA. These results...

  3. Exact results in nonequilibrium statistical mechanics: Formalism and applications in chemical kinetics and single-molecule free energy estimation

    Science.gov (United States)

    Adib, Artur B.

    In the last two decades or so, a collection of results in nonequilibrium statistical mechanics that departs from the traditional near-equilibrium framework introduced by Lars Onsager in 1931 has been derived, yielding new fundamental insights into far-from-equilibrium processes in general. Apart from offering a more quantitative statement of the second law of thermodynamics, some of these results---typified by the so-called "Jarzynski equality"---have also offered novel means of estimating equilibrium quantities from nonequilibrium processes, such as free energy differences from single-molecule "pulling" experiments. This thesis contributes to such efforts by offering three novel results in nonequilibrium statistical mechanics: (a) The entropic analog of the Jarzynski equality; (b) A methodology for estimating free energies from "clamp-and-release" nonequilibrium processes; and (c) A directly measurable symmetry relation in chemical kinetics similar to (but more general than) chemical detailed balance. These results share in common the feature of remaining valid outside Onsager's near-equilibrium regime, and bear direct applicability in protein folding kinetics as well as in single-molecule free energy estimation.

  4. Methods for intraoperative, sterile pose-setting of patient-specific microstereotactic frames

    Science.gov (United States)

    Vollmann, Benjamin; Müller, Samuel; Kundrat, Dennis; Ortmaier, Tobias; Kahrs, Lüder A.

    2015-03-01

    This work proposes new methods for a microstereotactic frame based on bone cement fixation. Microstereotactic frames are under investigation for minimal invasive temporal bone surgery, e.g. cochlear implantation, or for deep brain stimulation, where products are already on the market. The correct pose of the microstereotactic frame is either adjusted outside or inside the operating room and the frame is used for e.g. drill or electrode guidance. We present a patientspecific, disposable frame that allows intraoperative, sterile pose-setting. Key idea of our approach is bone cement between two plates that cures while the plates are positioned with a mechatronics system in the desired pose. This paper includes new designs of microstereotactic frames, a system for alignment and first measurements to analyze accuracy and applicable load.

  5. Making 2D face recognition more robust using AAMs for pose compensation

    NARCIS (Netherlands)

    Huisman, Peter; Munster, Ruud; Moro-Ellenberger, Stephanie; Veldhuis, Raymond N.J.; Bazen, A.M.

    2006-01-01

    The problem of pose in 2D face recognition is widely acknowledged. Commercial systems are limited to near frontal face images and cannot deal with pose deviations larger than 15 degrees from the frontal view. This is a problem, when using face recognition for surveillance applications in which

  6. Integrating Worked Examples into Problem Posing in a Web-Based Learning Environment

    Science.gov (United States)

    Hsiao, Ju-Yuan; Hung, Chun-Ling; Lan, Yu-Feng; Jeng, Yoau-Chau

    2013-01-01

    Most students always lack of experience and perceive difficult regarding problem posing. The study hypothesized that worked examples may have benefits for supporting students' problem posing activities. A quasi-experiment was conducted in the context of a business mathematics course for examining the effects of integrating worked examples into…

  7. Research on Single Base-Station Distance Estimation Algorithm in Quasi-GPS Ultrasonic Location System

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, X C; Su, S J; Wang, Y K; Du, J B [Instrument Department, College of Mechatronics Engineering and Automation, National University of Defense Technology, ChangSha, Hunan, 410073 (China)

    2006-10-15

    In order to identify each base-station in quasi-GPS ultrasonic location system, a unique pseudo-random code is assigned to each base-station. This article primarily studies the distance estimation problem between Autonomous Guide Vehicle (AGV) and single base-station, and then the ultrasonic spread-spectrum distance measurement Time Delay Estimation (TDE) model is established. Based on the above model, the envelope correlation fast TDE algorithm based on FFT is presented and analyzed. It shows by experiments that when the m sequence used in the received signal is as same as the reference signal, there will be a sharp correlation value in their envelope correlation function after they are processed by the above algorithm; otherwise, the will be no prominent correlation value. So, the AGV can identify each base-station easily.

  8. Research on Single Base-Station Distance Estimation Algorithm in Quasi-GPS Ultrasonic Location System

    International Nuclear Information System (INIS)

    Cheng, X C; Su, S J; Wang, Y K; Du, J B

    2006-01-01

    In order to identify each base-station in quasi-GPS ultrasonic location system, a unique pseudo-random code is assigned to each base-station. This article primarily studies the distance estimation problem between Autonomous Guide Vehicle (AGV) and single base-station, and then the ultrasonic spread-spectrum distance measurement Time Delay Estimation (TDE) model is established. Based on the above model, the envelope correlation fast TDE algorithm based on FFT is presented and analyzed. It shows by experiments that when the m sequence used in the received signal is as same as the reference signal, there will be a sharp correlation value in their envelope correlation function after they are processed by the above algorithm; otherwise, the will be no prominent correlation value. So, the AGV can identify each base-station easily

  9. A Hybrid Estimator for Active/Reactive Power Control of Single-Phase Distributed Generation Systems with Energy Storage

    DEFF Research Database (Denmark)

    Pahlevani, Majid; Eren, Suzan; Guerrero, Josep M.

    2016-01-01

    This paper presents a new active/reactive power closed-loop control system for a hybrid renewable energy generation system used for single-phase residential/commercial applications. The proposed active/reactive control method includes a hybrid estimator, which is able to quickly and accurately es...

  10. DFT-based channel estimation and noise variance estimation techniques for single-carrier FDMA

    OpenAIRE

    Huang, G; Nix, AR; Armour, SMD

    2010-01-01

    Practical frequency domain equalization (FDE) systems generally require knowledge of the channel and the noise variance to equalize the received signal in a frequency-selective fading channel. Accurate channel estimate and noise variance estimate are thus desirable to improve receiver performance. In this paper we investigate the performance of the denoise channel estimator and the approximate linear minimum mean square error (A-LMMSE) channel estimator with channel power delay profile (PDP) ...

  11. Winkler's single-parameter subgrade model from the perspective of ...

    African Journals Online (AJOL)

    ... tensor are taken into consideration, whereas the shear stresses are intentionally dropped with the purpose of providing a useful perspective, with which Winkler's model and its associated coefficient of subgrade reaction can be viewed. The formulation takes into account the variation of the elasticity modulus with depth.

  12. Attempts at estimating mixed venous carbon dioxide tension by the single-breath method.

    Science.gov (United States)

    Ohta, H; Takatani, O; Matsuoka, T

    1989-01-01

    The single-breath method was originally proposed by Kim et al. [1] for estimating the blood carbon dioxide tension and cardiac output. Its reliability has not been proven. The present study was undertaken, using dogs, to compare the mixed venous carbon dioxide tension (PVCO2) calculated by the single-breath method with the PVCO2 measured in mixed venous blood, and to evaluate the influence of variations in the exhalation duration and the volume of expired air usually discarded from computations as the deadspace. Among the exhalation durations of 15, 30 and 45 s tested, the 15 s duration was found to be too short to obtain an analyzable O2-CO2 curve, but at either 30 or 45 s, the calculated values of PVCO2 were comparable to the measured PVCO2. A significant agreement between calculated and measured PVCO2 was obtained when the expired gas with PCO2 less than 22 Torr was considered as deadspace gas.

  13. Improved pose and affinity predictions using different protocols tailored on the basis of data availability

    Science.gov (United States)

    Prathipati, Philip; Nagao, Chioko; Ahmad, Shandar; Mizuguchi, Kenji

    2016-09-01

    The D3R 2015 grand drug design challenge provided a set of blinded challenges for evaluating the applicability of our protocols for pose and affinity prediction. In the present study, we report the application of two different strategies for the two D3R protein targets HSP90 and MAP4K4. HSP90 is a well-studied target system with numerous co-crystal structures and SAR data. Furthermore the D3R HSP90 test compounds showed high structural similarity to existing HSP90 inhibitors in BindingDB. Thus, we adopted an integrated docking and scoring approach involving a combination of both pharmacophoric and heavy atom similarity alignments, local minimization and quantitative structure activity relationships modeling, resulting in the reasonable prediction of pose [with the root mean square deviation (RMSD) values of 1.75 Å for mean pose 1, 1.417 Å for the mean best pose and 1.85 Å for the mean all poses] and affinity (ROC AUC = 0.702 at 7.5 pIC50 cut-off and R = 0.45 for 180 compounds). The second protein, MAP4K4, represents a novel system with limited SAR and co-crystal structure data and little structural similarity of the D3R MAP4K4 test compounds to known MAP4K4 ligands. For this system, we implemented an exhaustive pose and affinity prediction protocol involving docking and scoring using the PLANTS software which considers side chain flexibility together with protein-ligand fingerprints analysis assisting in pose prioritization. This protocol through fares poorly in pose prediction (with the RMSD values of 4.346 Å for mean pose 1, 4.69 Å for mean best pose and 4.75 Å for mean all poses) and produced reasonable affinity prediction (AUC = 0.728 at 7.5 pIC50 cut-off and R = 0.67 for 18 compounds, ranked 1st among 80 submissions).

  14. Anticancer drugs in Portuguese surface waters - Estimation of concentrations and identification of potentially priority drugs.

    Science.gov (United States)

    Santos, Mónica S F; Franquet-Griell, Helena; Lacorte, Silvia; Madeira, Luis M; Alves, Arminda

    2017-10-01

    Anticancer drugs, used in chemotherapy, have emerged as new water contaminants due to their increasing consumption trends and poor elimination efficiency in conventional water treatment processes. As a result, anticancer drugs have been reported in surface and even drinking waters, posing the environment and human health at risk. However, the occurrence and distribution of anticancer drugs depend on the area studied and the hydrological dynamics, which determine the risk towards the environment. The main objective of the present study was to evaluate the risk of anticancer drugs in Portugal. This work includes an extensive analysis of the consumption trends of 171 anticancer drugs, sold or dispensed in Portugal between 2007 and 2015. The consumption data was processed aiming at the estimation of predicted environmental loads of anticancer drugs and 11 compounds were identified as potentially priority drugs based on an exposure-based approach (PEC b > 10 ng L -1 and/or PEC c > 1 ng L -1 ). In a national perspective, mycophenolic acid and mycophenolate mofetil are suspected to pose high risk to aquatic biota. Moderate and low risk was also associated to cyclophosphamide and bicalutamide exposition, respectively. Although no evidences of risk exist yet for the other anticancer drugs, concerns may be associated with long term effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Aquatic concentrations of chemical analytes compared to ecotoxicity estimates

    Data.gov (United States)

    U.S. Environmental Protection Agency — We describe screening level estimates of potential aquatic toxicity posed by 227 chemical analytes that were measured in 25 ambient water samples collected as part...

  16. The urban perspectives of acid rain

    International Nuclear Information System (INIS)

    Tonn, B.E.

    1993-01-01

    This report documents discussions held during a workshop an Urban Perspective of Acid Rain. The workshop was sponsored by the Office of the Director, National Acid Precipitation Assessment Program (NAPAP). NAPAP anticipates giving increased emphasis to the benefits in urban areas of emissions reductions. The goal of this informal, exploratory workshop was to serve as a first step towards identifying pollutant monitoring, and research and assessment needs to help answer, from an urban perspective, the two key questions posed to NAPAP by Congress: (1) what are the costs, benefits, and effectiveness of the acid rain control program, and (2) what reductions in deposition, rates are needed in order to prevent adverse effects? The workshop addressed research activities needed to respond to these questions. The discussions focused. sequentially, on data needs, data and model availability, and data and modeling gaps. The discussions concentrated on four areas of effects: human health, materials, urban forests, and visibility

  17. Time perception and psychopathology: Influence of time perspective on quality of life of severe mental illness.

    Science.gov (United States)

    Oyanadel, Cristián; Buela-Casal, Gualberto

    2014-01-01

    The study of time perception and mental illness has given priority to time estimation over time perspective. Considering Zimbardo’s theory on five dimensions of time perspective, and balanced time perspective profile, this study has aimed to compare people with severe mental illness (SMI) and healthy people, with measurements of time perspective and time estimation and to assess whether the time perspective profile influences the quality of life in people with SMI. Using a quasi-experimental design, a clinical group (n=167) corresponding to four samples of severe mental disorders (major depression, bipolar disorder, schizophrenia and personality disorders) and healthy people (n=167) were compared in their performance regarding time perspective and time estimation. After, the clinical sample was grouped according to their deviation from the balanced time perspective profile (DBTP) and negative profile (DNTP). These groups were evaluated with health measures and time estimation tasks. Through the ANOVA, it can be seen that the time perspective profile affects health measurements. There are significant differences between the clinical sample and controls regarding time perspective and time estimation. Within the group of patients, it was observed that those who were closer to the BTP profile had better physical health, and less hopelessness (ptime perspective in the assessment, treatment and quality of life of people with SMI.

  18. Problem-Posing in Education: Transformation of the Practice of the Health Professional.

    Science.gov (United States)

    Casagrande, L. D. R.; Caron-Ruffino, M.; Rodrigues, R. A. P.; Vendrusculo, D. M. S.; Takayanagui, A. M. M.; Zago, M. M. F.; Mendes, M. D.

    1998-01-01

    Studied the use of a problem-posing model in health education. The model based on the ideas of Paulo Freire is presented. Four innovative experiences of teaching-learning in environmental and occupational health and patient education are reported. Notes that the problem-posing model has the capability to transform health-education practice.…

  19. Error variation in OSL palaeodose estimates from single aliquots of quartz: a factorial experiment

    International Nuclear Information System (INIS)

    Galbraith, R.F.; Roberts, R.G.; Yoshida, H.

    2005-01-01

    We use a factorial experiment to study systematic and random differences between measured OSL palaeodoses for a variety of quartz samples. These include samples that have absorbed either a large or small natural or laboratory-induced radiation dose, either with or without prior heating or bleaching. The systematic factors studied are the size of the test dose, the preheat temperature and the number of quartz grains in each multi-grain aliquot. Palaeodoses were estimated using a single-aliquot regenerative-dose protocol. The main parameter of interest is the amount of random variation, over and above that due to photon counting statistics, to be expected between estimates from aliquots that have received the same radiation dose. This over-dispersion is generally larger for natural samples than for artificially bleached ones, and it varies from about 1% in the most favourable cases to about 18% for small aliquots of a sample that had received a natural dose of about 46 Gy. The latter is comparable to the over-dispersion reported for single grains of natural quartz that are thought to have been well-bleached at the time of deposition. The factorial experiment also revealed a number of systematic effects. In particular, measured palaeodoses using a preheat temperature of 260 deg. C were systematically lower than those using 180 deg. C, by up to about 5% in some cases

  20. Collaborative Random Faces-Guided Encoders for Pose-Invariant Face Representation Learning.

    Science.gov (United States)

    Shao, Ming; Zhang, Yizhe; Fu, Yun

    2018-04-01

    Learning discriminant face representation for pose-invariant face recognition has been identified as a critical issue in visual learning systems. The challenge lies in the drastic changes of facial appearances between the test face and the registered face. To that end, we propose a high-level feature learning framework called "collaborative random faces (RFs)-guided encoders" toward this problem. The contributions of this paper are three fold. First, we propose a novel supervised autoencoder that is able to capture the high-level identity feature despite of pose variations. Second, we enrich the identity features by replacing the target values of conventional autoencoders with random signals (RFs in this paper), which are unique for each subject under different poses. Third, we further improve the performance of the framework by incorporating deep convolutional neural network facial descriptors and linking discriminative identity features from different RFs for the augmented identity features. Finally, we conduct face identification experiments on Multi-PIE database, and face verification experiments on labeled faces in the wild and YouTube Face databases, where face recognition rate and verification accuracy with Receiver Operating Characteristic curves are rendered. In addition, discussions of model parameters and connections with the existing methods are provided. These experiments demonstrate that our learning system works fairly well on handling pose variations.

  1. Estimation of high-pT Jet Energy Scale Uncertainty from single hadron response with the ATLAS detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00534683; The ATLAS collaboration

    2016-01-01

    The jet energy scale (JES) uncertainty is estimated using different methods at different pT ranges. In situ techniques exploiting the pT balance between a jet and a reference object (e.g. Z or gamma) are used at lower pT, but at very high pT (> 2.5 TeV) there is not enough statistics for in-situ techniques. The JES uncertainty at high-pT is important in several searches for new phenomena, e.g. the dijet resonance and angular searches. In the highest pT range, the JES uncertainty is estimated using the calorimeter response to single hadrons. In this method, jets are treated as a superposition of energy depositions of single particles. An uncertainty is applied to each energy depositions belonging to the particles within the jet, and propagated to the final jet energy scale. This poster presents the JES uncertainty found with this method at sqrt(s) = 8 TeV and its developments.

  2. Generalized Hough transform based time invariant action recognition with 3D pose information

    Science.gov (United States)

    Muench, David; Huebner, Wolfgang; Arens, Michael

    2014-10-01

    Human action recognition has emerged as an important field in the computer vision community due to its large number of applications such as automatic video surveillance, content based video-search and human robot interaction. In order to cope with the challenges that this large variety of applications present, recent research has focused more on developing classifiers able to detect several actions in more natural and unconstrained video sequences. The invariance discrimination tradeoff in action recognition has been addressed by utilizing a Generalized Hough Transform. As a basis for action representation we transform 3D poses into a robust feature space, referred to as pose descriptors. For each action class a one-dimensional temporal voting space is constructed. Votes are generated from associating pose descriptors with their position in time relative to the end of an action sequence. Training data consists of manually segmented action sequences. In the detection phase valid human 3D poses are assumed as input, e.g. originating from 3D sensors or monocular pose reconstruction methods. The human 3D poses are normalized to gain view-independence and transformed into (i) relative limb-angle space to ensure independence of non-adjacent joints or (ii) geometric features. In (i) an action descriptor consists of the relative angles between limbs and their temporal derivatives. In (ii) the action descriptor consists of different geometric features. In order to circumvent the problem of time-warping we propose to use a codebook of prototypical 3D poses which is generated from sample sequences of 3D motion capture data. This idea is in accordance with the concept of equivalence classes in action space. Results of the codebook method are presented using the Kinect sensor and the CMU Motion Capture Database.

  3. The Effects of Problem Posing on Student Mathematical Learning: A Meta-Analysis

    Science.gov (United States)

    Rosli, Roslinda; Capraro, Mary Margaret; Capraro, Robert M.

    2014-01-01

    The purpose of the study was to meta-synthesize research findings on the effectiveness of problem posing and to investigate the factors that might affect the incorporation of problem posing in the teaching and learning of mathematics. The eligibility criteria for inclusion of literature in the meta-analysis was: published between 1989 and 2011,…

  4. Comparison of Single-Point and Continuous Sampling Methods for Estimating Residential Indoor Temperature and Humidity.

    Science.gov (United States)

    Johnston, James D; Magnusson, Brianna M; Eggett, Dennis; Collingwood, Scott C; Bernhardt, Scott A

    2015-01-01

    Residential temperature and humidity are associated with multiple health effects. Studies commonly use single-point measures to estimate indoor temperature and humidity exposures, but there is little evidence to support this sampling strategy. This study evaluated the relationship between single-point and continuous monitoring of air temperature, apparent temperature, relative humidity, and absolute humidity over four exposure intervals (5-min, 30-min, 24-hr, and 12-days) in 9 northern Utah homes, from March-June 2012. Three homes were sampled twice, for a total of 12 observation periods. Continuous data-logged sampling was conducted in homes for 2-3 wks, and simultaneous single-point measures (n = 114) were collected using handheld thermo-hygrometers. Time-centered single-point measures were moderately correlated with short-term (30-min) data logger mean air temperature (r = 0.76, β = 0.74), apparent temperature (r = 0.79, β = 0.79), relative humidity (r = 0.70, β = 0.63), and absolute humidity (r = 0.80, β = 0.80). Data logger 12-day means were also moderately correlated with single-point air temperature (r = 0.64, β = 0.43) and apparent temperature (r = 0.64, β = 0.44), but were weakly correlated with single-point relative humidity (r = 0.53, β = 0.35) and absolute humidity (r = 0.52, β = 0.39). Of the single-point RH measures, 59 (51.8%) deviated more than ±5%, 21 (18.4%) deviated more than ±10%, and 6 (5.3%) deviated more than ±15% from data logger 12-day means. Where continuous indoor monitoring is not feasible, single-point sampling strategies should include multiple measures collected at prescribed time points based on local conditions.

  5. Functional Perspectives on Emotion, Behavior, and Cognition

    Directory of Open Access Journals (Sweden)

    Logan A. Berg

    2013-10-01

    Full Text Available This Editorial reviews the challenges and advantages posed by a functional perspective on the relationships among emotion, behavior, and cognition. We identify the core themes among the articles published as part of this Special Issue. The articles generally address two important questions: (1 are emotions functional and what is their impact on behavioral and cognitive processes, and (2 how do the interactions among emotion, cognition, and behavior play out in particular situations that present adaptive challenges? We also identify two core questions raised by the articles included in this Special Issue. Future research must address the extent to which emotions are best represented as discrete emotional constructs (e.g., anger, sadness, fear versus emotions that vary along dimensions, such as valence and arousal. Functional perspectives would also be facilitated by identification of situations or environments that are likely to elicit particular emotions and reactions.

  6. Functional perspectives on emotion, behavior, and cognition.

    Science.gov (United States)

    Lench, Heather C; Darbor, Kathleen E; Berg, Logan A

    2013-12-01

    This Editorial reviews the challenges and advantages posed by a functional perspective on the relationships among emotion, behavior, and cognition. We identify the core themes among the articles published as part of this Special Issue. The articles generally address two important questions: (1) are emotions functional and what is their impact on behavioral and cognitive processes, and (2) how do the interactions among emotion, cognition, and behavior play out in particular situations that present adaptive challenges? We also identify two core questions raised by the articles included in this Special Issue. Future research must address the extent to which emotions are best represented as discrete emotional constructs (e.g., anger, sadness, fear) versus emotions that vary along dimensions, such as valence and arousal. Functional perspectives would also be facilitated by identification of situations or environments that are likely to elicit particular emotions and reactions.

  7. Trotting Gait of a Quadruped Robot Based on the Time-Pose Control Method

    Directory of Open Access Journals (Sweden)

    Cai RunBin

    2013-02-01

    Full Text Available We present the Time-Pose control method for the trotting gait of a quadruped robot on flat ground and up a slope. The method, with brief control structure, real-time operation ability and high adaptability, divides quadruped robot control into gait control and pose control. Virtual leg and intuitive controllers are introduced to simplify the model and generate the trajectory of mass centre and location of supporting legs in gait control, while redundancy optimization is used for solving the inverse kinematics in pose control. The models both on flat ground and up a slope are fully analysed, and different kinds of optimization methods are compared using the manipulability measure in order to select the best option. Simulations are performed, which prove that the Time-Pose control method is realizable for these two kinds of environment.

  8. Fundamental limits to frequency estimation: a comprehensive microscopic perspective

    Science.gov (United States)

    Haase, J. F.; Smirne, A.; Kołodyński, J.; Demkowicz-Dobrzański, R.; Huelga, S. F.

    2018-05-01

    We consider a metrology scenario in which qubit-like probes are used to sense an external field that affects their energy splitting in a linear fashion. Following the frequency estimation approach in which one optimizes the state and sensing time of the probes to maximize the sensitivity, we provide a systematic study of the attainable precision under the impact of noise originating from independent bosonic baths. Specifically, we invoke an explicit microscopic derivation of the probe dynamics using the spin-boson model with weak coupling of arbitrary geometry. We clarify how the secular approximation leads to a phase-covariant (PC) dynamics, where the noise terms commute with the field Hamiltonian, while the inclusion of non-secular contributions breaks the PC. Moreover, unless one restricts to a particular (i.e., Ohmic) spectral density of the bath modes, the noise terms may contain relevant information about the frequency to be estimated. Thus, by considering general evolutions of a single probe, we study regimes in which these two effects have a non-negligible impact on the achievable precision. We then consider baths of Ohmic spectral density yet fully accounting for the lack of PC, in order to characterize the ultimate attainable scaling of precision when N probes are used in parallel. Crucially, we show that beyond the semigroup (Lindbladian) regime the Zeno limit imposing the 1/N 3/2 scaling of the mean squared error, recently derived assuming PC, generalises to any dynamics of the probes, unless the latter are coupled to the baths in the direction perfectly transversal to the frequency encoding—when a novel scaling of 1/N 7/4 arises. As our microscopic approach covers all classes of dissipative dynamics, from semigroup to non-Markovian ones (each of them potentially non-phase-covariant), it provides an exhaustive picture, in which all the different asymptotic scalings of precision naturally emerge.

  9. Inferring Perspective Versus Getting Perspective: Underestimating the Value of Being in Another Person's Shoes.

    Science.gov (United States)

    Zhou, Haotian; Majka, Elizabeth A; Epley, Nicholas

    2017-04-01

    People use at least two strategies to solve the challenge of understanding another person's mind: inferring that person's perspective by reading his or her behavior (theorization) and getting that person's perspective by experiencing his or her situation (simulation). The five experiments reported here demonstrate a strong tendency for people to underestimate the value of simulation. Predictors estimated a stranger's emotional reactions toward 50 pictures. They could either infer the stranger's perspective by reading his or her facial expressions or simulate the stranger's perspective by watching the pictures he or she viewed. Predictors were substantially more accurate when they got perspective through simulation, but overestimated the accuracy they had achieved by inferring perspective. Predictors' miscalibrated confidence stemmed from overestimating the information revealed through facial expressions and underestimating the similarity in people's reactions to a given situation. People seem to underappreciate a useful strategy for understanding the minds of others, even after they gain firsthand experience with both strategies.

  10. Resource Discovery and Universal Access: Understanding Enablers and Barriers from the User Perspective

    OpenAIRE

    Beyene, Wondwossen

    2016-01-01

    Resource discovery tools are keys to explore, find , and retrieve resources from multitudes of collections hosted by library and information systems. Modern resource discovery tools provide facet - rich interfaces that provide multiple alternatives to ex pose resources for their potential users and help them navigate to the resources they need. This paper examines one of those tools from the perspective of universal access, ...

  11. Binary classification posed as a quadratically constrained quadratic ...

    Indian Academy of Sciences (India)

    Binary classification is posed as a quadratically constrained quadratic problem and solved using the proposed method. Each class in the binary classification problem is modeled as a multidimensional ellipsoid to forma quadratic constraint in the problem. Particle swarms help in determining the optimal hyperplane or ...

  12. Developing teachers' subject didactic competence through problem posing

    Czech Academy of Sciences Publication Activity Database

    Tichá, Marie; Hošpesová, A.

    2013-01-01

    Roč. 83, č. 1 (2013), s. 133-143 ISSN 0013-1954 Institutional support: RVO:67985840 Keywords : professional development * primary school teachers * problem posing Subject RIV: AM - Education Impact factor: 0.639, year: 2013 http://link.springer.com/article/10.1007%2Fs10649-012-9455-1

  13. Current status and future perspectives in laparoendoscopic single-site and natural orifice transluminal endoscopic urological surgery.

    Science.gov (United States)

    Autorino, Riccardo; Stein, Robert J; Lima, Estevão; Damiano, Rocco; Khanna, Rakesh; Haber, Georges-Pascal; White, Michael A; Kaouk, Jihad H

    2010-05-01

    Objective of this study is to provide an evidence-based analysis of the current status and future perspectives of scarless urological surgery. A PubMed search has been performed for all relevant urological literature regarding natural orifice transluminal endoscopic surgery (NOTES) and laparoendoscopic single-site surgery (LESS). In addition, experience with LESS and NOTES at our own institution has been considered. All clinical and investigative reports for LESS and NOTES procedures in the urological literature have been considered. A wide variety of clinical procedures in urology have been successfully completed by using LESS techniques. Thus far, experience with NOTES has largely been investigational, although early clinical reports are emerging. Further development of instrumentation and platforms is necessary for both techniques to become more widely adopted throughout the urological community.

  14. Inertial measurement unit–based iterative pose compensation algorithm for low-cost modular manipulator

    Directory of Open Access Journals (Sweden)

    Yunhan Lin

    2016-01-01

    Full Text Available It is a necessary mean to realize the accurate motion control of the manipulator which uses end-effector pose correction method and compensation method. In this article, first, we established the kinematic model and error model of the modular manipulator (WUST-ARM, and then we discussed the measurement methods and precision of the inertial measurement unit sensor. The inertial measurement unit sensor is mounted on the end-effector of modular manipulator, to get the real-time pose of the end-effector. At last, a new inertial measurement unit–based iterative pose compensation algorithm is proposed. By applying this algorithm in the pose compensation experiment of modular manipulator which is composed of low-cost rotation joints, the results show that the inertial measurement unit can obtain a higher precision when in static state; it will accurately feedback to the control system with an accurate error compensation angle after a brief delay when the end-effector moves to the target point, and after compensation, the precision errors of roll angle, pitch angle, and yaw angle are reached at 0.05°, 0.01°, and 0.27° respectively. It proves that this low-cost method provides a new solution to improve the end-effector pose of low-cost modular manipulator.

  15. Estimation by limiting dilution analysis of human IL 2-secreting T cells: detection of IL 2 produced by single lymphokine-secreting T cells

    International Nuclear Information System (INIS)

    Vie, H.; Miller, R.A.

    1986-01-01

    We present here a culture method for the estimation, in human blood, of the number of lymphocytes that can respond to mitogen by producing interleukin 2 (IL 2). T cells are cultured at limiting dilutions with PHA or Con A in the presence of Epstein Barr virus-transformed human lymphoblastoid cells (EB-LCL), and supernatants are tested 3 days later for IL 2 content by a cell proliferation assay. The distribution of negative wells follows the expected Poisson single-hit relationship, suggesting that the assay is sensitive to single cells of a single limiting cell type. On average, 16.3% of peripheral blood mononuclear cells can produce IL 2 in such clonal cultures (mean of 12 determinations; SD = 5.6%). Surprisingly, irradiation (up to 2000 rad) of the titrated responder cell population diminishes the estimated frequencies by less than 50%. The ability to detect IL 2 levels in cultures containing only a single, nonproliferating T lymphocyte allows us to estimate the amount of IL 2 generated by an individual effector cell during a 3-day culture interval after mitogen stimulation. The average responding, irradiated T cell generates 0.92 pg of IL 2 (median) within 3 days. The method presented provides a straightforward way to provide independent estimates of responding cell number and of lymphokine production per cell in a variety of clinical situations

  16. Absorbed dose estimates from a single measurement one to three days after the administration of 177Lu-DOTATATE/-TOC.

    Science.gov (United States)

    Hänscheid, Heribert; Lapa, Constantin; Buck, Andreas K; Lassmann, Michael; Werner, Rudolf A

    2017-01-01

    To retrospectively analyze the accuracy of absorbed dose estimates from a single measurement of the activity concentrations in tumors and relevant organs one to three days after the administration of 177 Lu-DOTA-TATE/TOC assuming tissue specific effective half-lives. Activity kinetics in 54 kidneys, 30 neuroendocrine tumor lesions, 25 livers, and 27 spleens were deduced from series of planar images in 29 patients. After adaptation of mono- or bi-exponential fit functions to the measured data, it was analyzed for each fit function how precise the time integral can be estimated from fixed tissue-specific half-lives and a single measurement at 24, 48, or 72 h after the administration. For the kidneys, assuming a fixed tissue-specific half-life of 50 h, the deviations of the estimate from the actual integral were median (5 % percentile, 95 % percentile): -3 °% (-15 %>; +16 °%) for measurements after 24 h, +2 %> (-9 %>; +12 %>) for measurements after 48 h, and 0 % (-2 %; +12 %) for measurements after 72 h. The corresponding values for the other tissues, assuming fixed tissue-specific half-lives of 67 h for liver and spleen and 77 h for tumors, were +2 % (-25 %; +20 %) for measurements after 24 h, +2 °% (-16 %>; +17 %>) for measurements after 48 h, and +2 %> (-11 %>; +10 %>) for measurements after 72 h. Especially for the kidneys, which often represent the dose limiting organ, but also for liver, spleen, and neuroendocrine tumors, a meaningful absorbed dose estimate is possible from a single measurement after 2, more preferably 3 days after the administration of 177 Lu-DOTA-TATE/-TOC assuming fixed tissue specific effective half-lives. Schattauer GmbH.

  17. THE LICK AGN MONITORING PROJECT: RECALIBRATING SINGLE-EPOCH VIRIAL BLACK HOLE MASS ESTIMATES

    Energy Technology Data Exchange (ETDEWEB)

    Park, Daeseong; Woo, Jong-Hak [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Treu, Tommaso; Bennert, Vardha N. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Barth, Aaron J.; Walsh, Jonelle [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697-4575 (United States); Bentz, Misty C. [Department of Physics and Astronomy, Georgia State University Atlanta, GA 30303 (United States); Canalizo, Gabriela [Department of Physics and Astronomy, University of California, Riverside, 900 University Ave., Riverside, CA 92521 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Gates, Elinor [Lick Observatory, P.O. Box 85, Mount Hamilton, CA 95140 (United States); Greene, Jenny E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Malkan, Matthew A., E-mail: woo@astro.snu.ac.kr [Department of Physics and Astronomy, University of California, Los Angeles, CA 90024 (United States)

    2012-03-01

    We investigate the calibration and uncertainties of black hole (BH) mass estimates based on the single-epoch (SE) method, using homogeneous and high-quality multi-epoch spectra obtained by the Lick Active Galactic Nucleus (AGN) Monitoring Project for nine local Seyfert 1 galaxies with BH masses <10{sup 8} M{sub Sun }. By decomposing the spectra into their AGNs and stellar components, we study the variability of the SE H{beta} line width (full width at half-maximum intensity, FWHM{sub H{beta}} or dispersion, {sigma}{sub H{beta}}) and of the AGN continuum luminosity at 5100 A (L{sub 5100}). From the distribution of the 'virial products' ({proportional_to} FWHM{sub H{beta}}{sup 2} L{sup 0.5}{sub 5100} or {sigma}{sub H{beta}}{sup 2} L{sup 0.5}{sub 5100}) measured from SE spectra, we estimate the uncertainty due to the combined variability as {approx}0.05 dex (12%). This is subdominant with respect to the total uncertainty in SE mass estimates, which is dominated by uncertainties in the size-luminosity relation and virial coefficient, and is estimated to be {approx}0.46 dex (factor of {approx}3). By comparing the H{beta} line profile of the SE, mean, and root-mean-square (rms) spectra, we find that the H{beta} line is broader in the mean (and SE) spectra than in the rms spectra by {approx}0.1 dex (25%) for our sample with FWHM{sub H{beta}} <3000 km s{sup -1}. This result is at variance with larger mass BHs where the difference is typically found to be much less than 0.1 dex. To correct for this systematic difference of the H{beta} line profile, we introduce a line-width dependent virial factor, resulting in a recalibration of SE BH mass estimators for low-mass AGNs.

  18. Health Issues: Do Cell Phones Pose a Health Hazard?

    Science.gov (United States)

    ... Procedures Home, Business, and Entertainment Products Cell Phones Health Issues Share Tweet Linkedin Pin it More sharing ... it Email Print Do cell phones pose a health hazard? Many people are concerned that cell phone ...

  19. Pose Self-Measurement of Noncooperative Spacecraft Based on Solar Panel Triangle Structure

    Directory of Open Access Journals (Sweden)

    Jingzhou Song

    2015-01-01

    Full Text Available Aiming at the recognition and location of noncooperative spacecraft, this paper presents a monocular vision pose measurement method based on solar triangle structure. First of all, an autonomous recognition algorithm of feature structure based on sliding window Hough transformation (SWHT and inscribed circle of a triangle is proposed, and the image coordinates of feature points on the triangle can be obtained relying on this algorithm, combined with the P4P algorithm and the structure of spacecraft, calculating the relative pose of target expressed by rotation and translation matrix. The whole algorithm can be loaded into the prewritten onboard program, which will get the autocomplete feature structure extraction and relative pose measurement without human intervention, and this method does not need to mount any markers on the target. Then compare the measured values with the accurate value of the laser tracker, so that a conclusion can be drawn that the maximum position error is lower than 5% and the rotation error is lower than 4%, which meets the requirements of noncooperative spacecraft’s pose measurement for observations, tracking, and docking in the final rendezvous phase.

  20. Mining Key Skeleton Poses with Latent SVM for Action Recognition

    Directory of Open Access Journals (Sweden)

    Xiaoqiang Li

    2017-01-01

    Full Text Available Human action recognition based on 3D skeleton has become an active research field in recent years with the recently developed commodity depth sensors. Most published methods analyze an entire 3D depth data, construct mid-level part representations, or use trajectory descriptor of spatial-temporal interest point for recognizing human activities. Unlike previous work, a novel and simple action representation is proposed in this paper which models the action as a sequence of inconsecutive and discriminative skeleton poses, named as key skeleton poses. The pairwise relative positions of skeleton joints are used as feature of the skeleton poses which are mined with the aid of the latent support vector machine (latent SVM. The advantage of our method is resisting against intraclass variation such as noise and large nonlinear temporal deformation of human action. We evaluate the proposed approach on three benchmark action datasets captured by Kinect devices: MSR Action 3D dataset, UTKinect Action dataset, and Florence 3D Action dataset. The detailed experimental results demonstrate that the proposed approach achieves superior performance to the state-of-the-art skeleton-based action recognition methods.

  1. Pose measurement method with six parameters for microassembly based on an optical micrometer

    Science.gov (United States)

    Ye, Xin; Wang, Qiang; Zhang, Zhi-jing; Sun, Yuan; Zhang, Xiao-feng

    2009-07-01

    This paper presents a new pose measurement method of microminiature parts that is capable of transforming one dimension (1D) contour size obtained by optical micrometer to three dimension (3D) data with six parameters for microassembly. Pose measurement is one of the most important processes for microminiature parts' alignment and insertion in microassembly. During the past few years, researchers have developed their microassembly systems focusing on visual identification to obtain two or three dimension data with no more than three parameters. Scanning electronic microscope (SEM), optical microscope, and stereomicroscope are applied in their systems. However, as structures of microminiature parts become increasingly complex, six parameters to represent their position and orientation are specifically needed. Firstly, The pose measurement model is established based on the introduction of measuring objects and measuring principle of optical micrometer. The measuring objects are microminiature parts with complex 3D structure. Two groups of two dimension (2D) data are gathered at two different measurement positions. Then part pose with 6 parameters is calculated, including 3 position parameters of feature point of the part and 3 orientation parameters of the part axis. Secondly, pose measurement process for a small shaft, vertical orientation determination, and position parameters obtaining are presented. 2D data is gathered by scanning the generatrix of the part, and valid data is extracted and saved in arrays. A vertical orientation criterion is proposed to determine whether the part is parallel to the Z-axis of the coordinate. If not, 2D data will be fixed into a linear equation using least square algorithm. Then orientation parameters are calculated. Center of Part End (CPE) is selected as feature point of the part, and its position parameters are extracted form two group of 2D data. Finally, a fast pose measurement device is developed and representative

  2. Asynchronous vehicle pose correction using visual detection of ground features

    International Nuclear Information System (INIS)

    Harnarinesingh, Randy E S; Syan, Chanan S

    2014-01-01

    The inherent noise associated with odometry manifests itself as errors in localization for autonomous vehicles. Visual odometry has been previously used in order to supplement classical vehicle odometry. However, visual odometry is limited in its ability to reduce errors in localization for large travel distances that entail the cumulative summing of individual frame-to-frame image errors. In this paper, a novel machine vision approach for tiled surfaces is proposed to address this problem. Tile edges in a laboratory environment are used to define a travel trajectory for the Quansar Qbot (autonomous vehicle) built on the iRobot iRoomba platform with a forward facing camera. Tile intersections are used to enable asynchronous error recovery for vehicle position and orientation. The proposed approach employs real-time image classification and is feasible for error mitigation for large travel distances. The average position error for an 8m travel distance using classical odometry was measured to be 0.28m. However, implementation of the proposed approach resulted in an error of 0.028m. The proposed approach therefore significantly reduces pose estimation error and could be used to supplement existing modalities such as GPS and Laser-based range sensors

  3. Perbedaan Keterampilan Pemecahan Masalah pada Pembelajaran Fisika Menggunakan Metode Problem Posing dan Problem Solving

    OpenAIRE

    Rahman, Adetya; Hartini, Sri; An'nur, Syubhan

    2015-01-01

    Teachers should be able to choose the method of learning that can help students in learning physics, namely the method of problem posing and problem solving method. The purposes of this study are : (1) describe the learning physics skills by using problem posing method, (2) describe the learning physics skills by using problem solving method, and (3) know difference between learning physics skills by using problem posing method and problem solving method in class XI of Science SMAN 6 Banjarma...

  4. Limitations of the equivalence between spatial and ensemble estimators in the case of a single-tone excitation.

    Science.gov (United States)

    Monsef, Florian; Cozza, Andrea

    2011-10-01

    The ensemble-average value of the mean-square pressure is often assessed by using the spatial-average technique, underlying an equivalence principle between spatial and ensemble estimators. Using the ideal-diffuse-field model, the accuracy of the spatial-average method has been studied theoretically forty years ago in the case of a single-tone excitation. This study is revisited in the present work on the basis of a more realistic description of the sound field accounting for a finite number of plane waves. The analysis of the spatial-average estimator is based on the study of its convergence rate. Using experimental data from practical examples, it is shown that the classical expression underestimates the estimator uncertainty even for frequencies greater than Schroeder's frequency, and that the number of plane waves may act as lower bound on the spatial-average estimator accuracy. The comparison of the convergence rate with an ensemble-estimator shows that the two statistics cannot be regarded as equivalent in a general case. © 2011 Acoustical Society of America

  5. Estimates for Genetic Variance Components in Reciprocal Recurrent Selection in Populations Derived from Maize Single-Cross Hybrids

    Directory of Open Access Journals (Sweden)

    Matheus Costa dos Reis

    2014-01-01

    Full Text Available This study was carried out to obtain the estimates of genetic variance and covariance components related to intra- and interpopulation in the original populations (C0 and in the third cycle (C3 of reciprocal recurrent selection (RRS which allows breeders to define the best breeding strategy. For that purpose, the half-sib progenies of intrapopulation (P11 and P22 and interpopulation (P12 and P21 from populations 1 and 2 derived from single-cross hybrids in the 0 and 3 cycles of the reciprocal recurrent selection program were used. The intra- and interpopulation progenies were evaluated in a 10×10 triple lattice design in two separate locations. The data for unhusked ear weight (ear weight without husk and plant height were collected. All genetic variance and covariance components were estimated from the expected mean squares. The breakdown of additive variance into intrapopulation and interpopulation additive deviations (στ2 and the covariance between these and their intrapopulation additive effects (CovAτ found predominance of the dominance effect for unhusked ear weight. Plant height for these components shows that the intrapopulation additive effect explains most of the variation. Estimates for intrapopulation and interpopulation additive genetic variances confirm that populations derived from single-cross hybrids have potential for recurrent selection programs.

  6. Communication perspectives on social networking and citizen journalism challenges to traditional newspapers

    OpenAIRE

    Katz, James E.

    2011-01-01

    Communication perspectives are presented on the challenges posed to traditional newspapers by social media and citizen journalism, with special reference to the United States. This is an important topic given the critical role investigative reporting, long the domain of newspapers, plays in fostering democratic practices. New Media and social networking technology are evaluated in terms of their impact on the newspaper enterprise. Alternative scenarios for future developments are examined as ...

  7. The Effect of Problem Solving and Problem Posing Models and Innate Ability to Students Achievement

    Directory of Open Access Journals (Sweden)

    Ratna Kartika Irawati

    2015-04-01

    Full Text Available Pengaruh Model Problem Solving dan Problem Posing serta Kemampuan Awal terhadap Hasil Belajar Siswa   Abstract: Chemistry concepts understanding features abstract quality and requires higher order thinking skills. Yet, the learning on chemistry has not boost the higher order thinking skills of the students. The use of the learning model of Problem Solving and Problem Posing in observing the innate ability of the student is expected to resolve the issue. This study aims to determine the learning model which is effective to improve the study of the student with different level of innate ability. This study used the quasi-experimental design. The research data used in this research is the quiz/test of the class which consist of 14 multiple choice questions and 5 essay questions. The data analysis used is ANOVA Two Ways. The results showed that Problem Posing is more effective to improve the student compared to Problem Solving, students with high level of innate ability have better outcomes in learning rather than the students with low level of innate ability after being applied with the Problem solving and Problem posing model, further, Problem Solving and Problem Posing is more suitable to be applied to the students with high level of innate ability. Key Words: problem solving, problem posing, higher order thinking skills, innate ability, learning outcomes   Abstrak: Pemahaman konsep-konsep kimia yang bersifat abstrak membutuhkan keterampilan berpikir tingkat tinggi. Pembelajaran kimia belum mendorong siswa melakukan keterampilan berpikir tingkat tinggi. Penggunaan model pembelajaran Problem Solving dan Problem Posing dengan memperhatikan kemampuan awal siswa diduga dapat mengatasi masalah tersebut. Penelitian ini bertujuan untuk mengetahui model pembelajaran yang efektif dalam meningkatkan hasil belajar dengan kemampuan awal siswa yang berbeda. Penelitian ini menggunakan rancangan eksperimen semu. Data penelitian menggunakan tes hasil belajar

  8. Fraction Multiplication and Division Word Problems Posed by Different Years of Pre-Service Elementary Mathematics Teachers

    Directory of Open Access Journals (Sweden)

    Tuba Aydogdu Iskenderoglu

    2018-04-01

    Full Text Available It is important for pre-service teachers to know the conceptual difficulties they have experienced regarding the concepts of multiplication and division in fractions and problem posing is a way to learn these conceptual difficulties. Problem posing is a synthetic activity that fundamentally has multiple answers. The purpose of this study is to analyze the multiplication and division of fractions problems posed by pre-service elementary mathematics teachers and to investigate how the problems posed change according to the year of study the pre-service teachers are in. The study employed developmental research methods. A total of 213 pre-service teachers enrolled in different years of the Elementary Mathematics Teaching program at a state university in Turkey took part in the study. The “Problem Posing Test” was used as the data collecting tool. In this test, there are 3 multiplication and 3 division operations. The data were analyzed using qualitative descriptive analysis. The findings suggest that, regardless of the year, pre-service teachers had more conceptual difficulties in problem posing about the division of fractions than in problem posing about the multiplication of fractions.

  9. Robust Estimation for a CSTR Using a High Order Sliding Mode Observer and an Observer-Based Estimator

    Directory of Open Access Journals (Sweden)

    Esteban Jiménez-Rodríguez

    2016-12-01

    Full Text Available This paper presents an estimation structure for a continuous stirred-tank reactor, which is comprised of a sliding mode observer-based estimator coupled with a high-order sliding-mode observer. The whole scheme allows the robust estimation of the state and some parameters, specifically the concentration of the reactive mass, the heat of reaction and the global coefficient of heat transfer, by measuring the temperature inside the reactor and the temperature inside the jacket. In order to verify the results, the convergence proof of the proposed structure is done, and numerical simulations are presented with noiseless and noisy measurements, suggesting the applicability of the posed approach.

  10. Meanings Given to Algebraic Symbolism in Problem-Posing

    Science.gov (United States)

    Cañadas, María C.; Molina, Marta; del Río, Aurora

    2018-01-01

    Some errors in the learning of algebra suggest that students might have difficulties giving meaning to algebraic symbolism. In this paper, we use problem posing to analyze the students' capacity to assign meaning to algebraic symbolism and the difficulties that students encounter in this process, depending on the characteristics of the algebraic…

  11. Estimated radiation doses to different organs among patients treated for ankylosing spondylitis with a single course of X rays

    International Nuclear Information System (INIS)

    Lewis, C.A.; Smith, P.G.; Stratton, I.M.; Darby, S.C.; Doll, R.

    1988-01-01

    A follow-up study of over 14000 patients treated with a single course of X rays for ankylosing spondylitis demonstrated substantial excess risk of developing cancer. Previously the excess risk of leukaemia has been related to the estimated mean radiation dose to active bone marrow but detailed estimates were not made of the radiation doses to other organs. Data extracted from the original treatment records of a random sample of one in 15 patients have been used to make dose estimates, using Monte Carlo methods, for 30 specific organs or body regions and 12 bone marrow sites. Estimates of mean and median organ doses, standard deviations and ranges have been tabulated. Detailed distributions are presented for six organs (lung, bronchi, stomach, oesophagus, active bone marrow and total body). Comparison with the earlier bone marrow estimates and more recent theoretical estimates shows good agreement. (author)

  12. A fast and reliable method for simultaneous waveform, amplitude and latency estimation of single-trial EEG/MEG data.

    Directory of Open Access Journals (Sweden)

    Wouter D Weeda

    Full Text Available The amplitude and latency of single-trial EEG/MEG signals may provide valuable information concerning human brain functioning. In this article we propose a new method to reliably estimate single-trial amplitude and latency of EEG/MEG signals. The advantages of the method are fourfold. First, no a-priori specified template function is required. Second, the method allows for multiple signals that may vary independently in amplitude and/or latency. Third, the method is less sensitive to noise as it models data with a parsimonious set of basis functions. Finally, the method is very fast since it is based on an iterative linear least squares algorithm. A simulation study shows that the method yields reliable estimates under different levels of latency variation and signal-to-noise ratioÕs. Furthermore, it shows that the existence of multiple signals can be correctly determined. An application to empirical data from a choice reaction time study indicates that the method describes these data accurately.

  13. The rarity of "unusual" [corrected] dispositions of victim bodies: staging and posing.

    Science.gov (United States)

    Keppel, Robert D; Weis, Joseph G

    2004-11-01

    The act of leaving a victim's body in an unusual position is a conscious criminal action by an offender to thwart an investigation, shock the finder and investigators of the crime scene, or give perverted pleasure to the killer. The unusual position concepts of posing and staging a murder victim have been documented thoroughly and have been accepted by the courts as a definable phenomenon. One staging case and one posing case are outlined and reveal characteristics of those homicides. From the Washington State Attorney General's Homicide Investigation and Tracking System's database on murder covering the years 1981-2000 (a total of 5,224 cases), the relative frequency of unusual body dispositions is revealed as a very rare occurrence. Only 1.3% of victims are left in an unusual position, with 0.3% being posed and 0.1% being staged. The characteristics of these types of murders also set them apart: compared to all other murders, in staged murders the victims and killers are, on average, older. All victims and offenders in the staged murders are white, with victims being disproportionately white in murders with any kind of unusual body disposition. Likewise, females stand out as victims when the body is posed, staged, or left in other unusual positions. Whereas posed bodies are more likely to include sexual assault, often in serial murders, there is no evidence of either in the staged cases. Lastly, when a body is left in an unusual position, binding is more likely, as well as the use of more "hands on" means of killing the victim, such as stabbing or cutting weapons, bludgeons, ligatures, or hands and feet.

  14. Event-based state estimation a stochastic perspective

    CERN Document Server

    Shi, Dawei; Chen, Tongwen

    2016-01-01

    This book explores event-based estimation problems. It shows how several stochastic approaches are developed to maintain estimation performance when sensors perform their updates at slower rates only when needed. The self-contained presentation makes this book suitable for readers with no more than a basic knowledge of probability analysis, matrix algebra and linear systems. The introduction and literature review provide information, while the main content deals with estimation problems from four distinct angles in a stochastic setting, using numerous illustrative examples and comparisons. The text elucidates both theoretical developments and their applications, and is rounded out by a review of open problems. This book is a valuable resource for researchers and students who wish to expand their knowledge and work in the area of event-triggered systems. At the same time, engineers and practitioners in industrial process control will benefit from the event-triggering technique that reduces communication costs ...

  15. Cross-disciplinary Science and the Structure of Scientific Perspectives

    DEFF Research Database (Denmark)

    Alrøe, Hugo Fjelsted; Noe, Egon

    2014-01-01

    of science, focusing on the synchronic structure of scientific perspectives across disciplines and not on the diachronic, historical structure of shifting perspectives within single disciplines that has been widely discussed since Kuhn and Feyerabend. We show what kinds of cross-disciplinary disagreement...

  16. Estimation of the LET threshold of single event upset of microelectronics in experiments with Cf-252

    International Nuclear Information System (INIS)

    Kuznetsov, N.V.; Nymmik, R.A.

    1996-01-01

    A method is proposed for analyzing single event upsets (SEU) in large scale integration circuits of random access memory (RAM) when exposed to Cf-252 fission fragments. The method makes is possible to find the RAM linear energy transfer (LET) threshold to be used for estimations of RAM SEU rates in space. The method is illustrated by analyzing experimental data for the 2 x 8 kbit CMOS/bulk RAM. (author)

  17. Predicting binding poses and affinities for protein - ligand complexes in the 2015 D3R Grand Challenge using a physical model with a statistical parameter estimation

    Science.gov (United States)

    Grudinin, Sergei; Kadukova, Maria; Eisenbarth, Andreas; Marillet, Simon; Cazals, Frédéric

    2016-09-01

    The 2015 D3R Grand Challenge provided an opportunity to test our new model for the binding free energy of small molecules, as well as to assess our protocol to predict binding poses for protein-ligand complexes. Our pose predictions were ranked 3-9 for the HSP90 dataset, depending on the assessment metric. For the MAP4K dataset the ranks are very dispersed and equal to 2-35, depending on the assessment metric, which does not provide any insight into the accuracy of the method. The main success of our pose prediction protocol was the re-scoring stage using the recently developed Convex-PL potential. We make a thorough analysis of our docking predictions made with AutoDock Vina and discuss the effect of the choice of rigid receptor templates, the number of flexible residues in the binding pocket, the binding pocket size, and the benefits of re-scoring. However, the main challenge was to predict experimentally determined binding affinities for two blind test sets. Our affinity prediction model consisted of two terms, a pairwise-additive enthalpy, and a non pairwise-additive entropy. We trained the free parameters of the model with a regularized regression using affinity and structural data from the PDBBind database. Our model performed very well on the training set, however, failed on the two test sets. We explain the drawback and pitfalls of our model, in particular in terms of relative coverage of the test set by the training set and missed dynamical properties from crystal structures, and discuss different routes to improve it.

  18. Zebra Mussels Pose a Threat to Virginia's Waters

    OpenAIRE

    Helfrich, Louis A. (Louis Anthony), 1942-; Weigmann, Diana L.; Speenburgh, Renee M.; Neves, Richard J.; Kitchel, Lisie; Bruenderman, Sue A., 1962-

    2005-01-01

    Provides an brief introduction to the invasion of the zebra mussel into American waters, explains the economic consequences they pose, and discusses if Virginia will inherit the problem, what the public can do to help, the general lifecycle of the zebra mussel and if they can be controlled, and who is working on the zebra mussel problem.

  19. Winners, losers, and posers: The effect of power poses on testosterone and risk-taking following competition.

    Science.gov (United States)

    Smith, Kristopher M; Apicella, Coren L

    2017-06-01

    A contribution to a special issue on Hormones and Human Competition. The effect of postural power displays (i.e. power poses) on hormone levels and decision-making has recently been challenged. While Carney et al. (2010) found that holding brief postural displays of power leads to increased testosterone, decreased cortisol and greater economic risk taking, this failed to replicate in a recent high-powered study (Ranehill et al. 2015). It has been put forward that subtle differences in social context may account for the differences in results. Power displays naturally occur within the context of competitions, as do changes in hormones, and researchers have yet to examine the effects of poses within this ecologically relevant context. Using a large sample of 247 male participants, natural winners and losers of a physical competition were randomly assigned to hold a low, neutral or high-power postural display. We found no main effect of pose type on testosterone, cortisol, risk or feelings of power. Winners assigned to a high-power pose had a relative, albeit small, rise in testosterone compared to winners who held neutral or low-power poses. For losers, we found little evidence that high-power poses lead to increased testosterone relative to those holding neutral or low-powered poses. If anything, the reverse was observed - losers had a reduction in testosterone after holding high-power poses. To the extent that changes in testosterone modulate social behaviors adaptively, it is possible that the relative reduction in testosterone observed in losers taking high-powered poses is designed to inhibit further "winner-like" behavior that could result in continued defeat and harm. Still, effects were small, multiple comparisons were made, and the results ran counter to our predictions. We thus treat these conclusions as preliminary. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. State estimation for large-scale wastewater treatment plants.

    Science.gov (United States)

    Busch, Jan; Elixmann, David; Kühl, Peter; Gerkens, Carine; Schlöder, Johannes P; Bock, Hans G; Marquardt, Wolfgang

    2013-09-01

    Many relevant process states in wastewater treatment are not measurable, or their measurements are subject to considerable uncertainty. This poses a serious problem for process monitoring and control. Model-based state estimation can provide estimates of the unknown states and increase the reliability of measurements. In this paper, an integrated approach is presented for the optimization-based sensor network design and the estimation problem. Using the ASM1 model in the reference scenario BSM1, a cost-optimal sensor network is designed and the prominent estimators EKF and MHE are evaluated. Very good estimation results for the system comprising 78 states are found requiring sensor networks of only moderate complexity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Economic evaluation of single-tooth replacement: dental implant versus fixed partial denture.

    Science.gov (United States)

    Kim, Younhee; Park, Joo-Yeon; Park, Sun-Young; Oh, Sung-Hee; Jung, YeaJi; Kim, Ji-Min; Yoo, Soo-Yeon; Kim, Seong-Kyun

    2014-01-01

    This study assessed the cost-effectiveness from a societal perspective of a dental implant compared with a three-unit tooth-supported fixed partial denture (FPD) for the replacement of a single tooth in 2010. A decision tree was developed to estimate cost-effectiveness over a 10-year period. The survival rates of single-tooth implants and FPDs were extracted from a meta-analysis of single-arm studies. Medical costs included initial treatment costs, maintenance costs, and costs to treat complications. Patient surveys were used to obtain the costs of the initial single-tooth implant or FPD. Maintenance costs and costs to treat complications were based on surveys of seven clinical experts at dental clinics or hospitals. Transportation costs were calculated based on the number of visits for implant or FPD treatment. Patient time costs were estimated using the number of visits and time required, hourly wage, and employment rate. Future costs were discounted by 5% to convert to present values. The results of a 10-year period model showed that a single dental implant cost US $261 (clinic) to $342 (hospital) more than an FPD and had an average survival rate that was 10.4% higher. The incremental cost-effectiveness ratio was $2,514 in a clinic and $3,290 in a hospital for a prosthesis in situ for 10 years. The sensitivity analysis showed that initial treatment costs and survival rate influenced the cost-effectiveness. If the cost of an implant were reduced to 80% of the current cost, the implant would become the dominant intervention. Although the level of evidence for effectiveness is low, and some aspects of single-tooth implants or FPDs, such as satisfaction, were not considered, this study will help patients requiring single-tooth replacement to choose the best treatment option.

  2. Adaptive relative pose control of spacecraft with model couplings and uncertainties

    Science.gov (United States)

    Sun, Liang; Zheng, Zewei

    2018-02-01

    The spacecraft pose tracking control problem for an uncertain pursuer approaching to a space target is researched in this paper. After modeling the nonlinearly coupled dynamics for relative translational and rotational motions between two spacecraft, position tracking and attitude synchronization controllers are developed independently by using a robust adaptive control approach. The unknown kinematic couplings, parametric uncertainties, and bounded external disturbances are handled with adaptive updating laws. It is proved via Lyapunov method that the pose tracking errors converge to zero asymptotically. Spacecraft close-range rendezvous and proximity operations are introduced as an example to validate the effectiveness of the proposed control approach.

  3. Single Tree Vegetation Depth Estimation Tool for Satellite Services Link Design

    Directory of Open Access Journals (Sweden)

    Z. Hasirci

    2016-04-01

    Full Text Available Attenuation caused by tree shadowing is an important factor for describing the propagation channel of satellite services. Thus, vegetation effects should be determined by experimental studies or empirical formulations. In this study, tree types in the Black Sea Region of Turkey are classified based on their geometrical shapes into four groups such as conic, ellipsoid, spherical and hemispherical. The variations of the vegetation depth according to different tree shapes are calculated with ray tracing method. It is showed that different geometrical shapes have different vegetation depths even if they have same foliage volume for different elevation angles. The proposed method is validated with the related literature in terms of average single tree attenuation. On the other hand, due to decrease system requirements (speed, memory usage etc. of ray tracing method, an artificial neural network is proposed as an alternative. A graphical user interface is created for the above processes in MATLAB environment named vegetation depth estimation tool (VdET.

  4. ESPRIT: Exercise Sensing and Pose Recovery Inference Tool, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop ESPRIT: an Exercise Sensing and Pose Recovery Inference Tool, in support of NASA's effort in developing crew exercise technologies for...

  5. Reliability Estimation for Single-unit Ceramic Crown Restorations

    Science.gov (United States)

    Lekesiz, H.

    2014-01-01

    The objective of this study was to evaluate the potential of a survival prediction method for the assessment of ceramic dental restorations. For this purpose, fast-fracture and fatigue reliabilities for 2 bilayer (metal ceramic alloy core veneered with fluorapatite leucite glass-ceramic, d.Sign/d.Sign-67, by Ivoclar; glass-infiltrated alumina core veneered with feldspathic porcelain, VM7/In-Ceram Alumina, by Vita) and 3 monolithic (leucite-reinforced glass-ceramic, Empress, and ProCAD, by Ivoclar; lithium-disilicate glass-ceramic, Empress 2, by Ivoclar) single posterior crown restorations were predicted, and fatigue predictions were compared with the long-term clinical data presented in the literature. Both perfectly bonded and completely debonded cases were analyzed for evaluation of the influence of the adhesive/restoration bonding quality on estimations. Material constants and stress distributions required for predictions were calculated from biaxial tests and finite element analysis, respectively. Based on the predictions, In-Ceram Alumina presents the best fast-fracture resistance, and ProCAD presents a comparable resistance for perfect bonding; however, ProCAD shows a significant reduction of resistance in case of complete debonding. Nevertheless, it is still better than Empress and comparable with Empress 2. In-Ceram Alumina and d.Sign have the highest long-term reliability, with almost 100% survivability even after 10 years. When compared with clinical failure rates reported in the literature, predictions show a promising match with clinical data, and this indicates the soundness of the settings used in the proposed predictions. PMID:25048249

  6. Pose tracking for augmented reality applications in outdoor archaeological sites

    Science.gov (United States)

    Younes, Georges; Asmar, Daniel; Elhajj, Imad; Al-Harithy, Howayda

    2017-01-01

    In recent years, agencies around the world have invested huge amounts of effort toward digitizing many aspects of the world's cultural heritage. Of particular importance is the digitization of outdoor archaeological sites. In the spirit of valorization of this digital information, many groups have developed virtual or augmented reality (AR) computer applications themed around a particular archaeological object. The problem of pose tracking in outdoor AR applications is addressed. Different positional systems are analyzed, resulting in the selection of a monocular camera-based user tracker. The limitations that challenge this technique from map generation, scale, anchoring, to lighting conditions are analyzed and systematically addressed. Finally, as a case study, our pose tracking system is implemented within an AR experience in the Byblos Roman theater in Lebanon.

  7. A simple tool for estimating city-wide annual electrical energy savings from cooler surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pomerantz, Melvin; Rosado, Pablo J.; Levinson, Ronnen

    2015-12-01

    We present a simple method to estimate the maximum possible electrical energy saving that might be achieved by increasing the albedo of surfaces in a large city. We restrict this to the “indirect effect”, the cooling of outside air that lessens the demand for air conditioning (AC). Given the power demand of the electric utilities and data about the city, we can use a single linear equation to estimate the maximum savings. For example, the result for an albedo change of 0.2 of pavements in a typical warm city in California, such as Sacramento, is that the saving is less than about 2 kWh per m2 per year. This may help decision makers choose which heat island mitigation techniques are economical from an energy-saving perspective.

  8. Deformation-specific and deformation-invariant visual object recognition: pose vs identity recognition of people and deforming objects

    Directory of Open Access Journals (Sweden)

    Tristan J Webb

    2014-04-01

    Full Text Available When we see a human sitting down, standing up, or walking, we can recognise one of these poses independently of the individual, or we can recognise the individual person, independently of the pose. The same issues arise for deforming objects. For example, if we see a flag deformed by the wind, either blowing out or hanging languidly, we can usually recognise the flag, independently of its deformation; or we can recognise the deformation independently of the identity of the flag. We hypothesize that these types of recognition can be implemented by the primate visual system using temporo-spatial continuity as objects transform as a learning principle. In particular, we hypothesize that pose or deformation can be learned under conditions in which large numbers of different people are successively seen in the same pose, or objects in the same deformation. We also hypothesize that person-specific representations that are independent of pose, and object-specific representations that are independent of deformation and view, could be built, when individual people or objects are observed successively transforming from one pose or deformation and view to another. These hypotheses were tested in a simulation of the ventral visual system, VisNet, that uses temporal continuity, implemented in a synaptic learning rule with a short-term memory trace of previous neuronal activity, to learn invariant representations. It was found that depending on the statistics of the visual input, either pose-specific or deformation-specific representations could be built that were invariant with respect to individual and view; or that identity-specific representations could be built that were invariant with respect to pose or deformation and view. We propose that this is how pose-specific and pose-invariant, and deformation-specific and deformation-invariant, perceptual representations are built in the brain.

  9. Climate change adaptation strategies for federal forests of the Pacific Northwest, USA: ecological, policy, and socio-economic perspectives

    Science.gov (United States)

    Thomas A. Spies; Thomas W. Giesen; Frederick J. Swanson; Jerry F. Franklin; Denise Lach; K. Norman. Johnson

    2010-01-01

    Conserving biological diversity in a changing climate poses major challenges for land managers and society. Effective adaptive strategies for dealing with climate change require a socioecological systems perspective. We highlight some of the projected ecological responses to climate change in the Pacific Northwest, U.S.A and identify possible adaptive actions that...

  10. Muscle utilization patterns vary by skill levels of the practitioners across specific yoga poses (asanas).

    Science.gov (United States)

    Ni, Meng; Mooney, Kiersten; Balachandran, Anoop; Richards, Luca; Harriell, Kysha; Signorile, Joseph F

    2014-08-01

    To compare muscle activation patterns in 14 dominant side muscles during different yoga poses across three skill levels. Mixed repeated-measures descriptive study. University neuromuscular research laboratory, Miami, US. A group of 36 yoga practitioners (9 M/27 F; mean ± SD, 31.6 ± 12.6 years) with at least 3 months yoga practice experience. Each of the 11 surya namaskar poses A and B was performed separately for 15s and the surface electromyography for 14 muscles were recorded. Normalized root mean square of the electromyographic signal (NrmsEMG) for 14 muscles (5 upper body, 4 trunk, 5 lower body). There were significant main effects of pose for all fourteen muscles except middle trapezius (p<.02) and of skill level for the vastus medialis; p=.027). A significant skill level × pose interaction existed for five muscles (pectoralis major sternal head, anterior deltoid, medial deltoid, upper rectus abdominis and gastrocnemius lateralis; p<.05). Post hoc analyses using Bonferroni comparisons indicated that different poses activated specific muscle groups; however, this varied by skill level. Our results indicate that different poses can produce specific muscle activation patterns which may vary due to practitioners' skill levels. This information can be used in designing rehabilitation and training programs and for cuing during yoga training. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Blended learning experience in teacher education: the trainees´ perspective

    Directory of Open Access Journals (Sweden)

    Monika Černá

    2009-03-01

    Full Text Available The article deals with blended learning in the context of pre-graduate English language teacher education. Firstly, the concept of blended learning is defined, then, the attention is focused on the online component of a blend, namely on the issue of interpersonal interaction including the challenges, which learning through online networking poses. Finally, results of a small–scale research are provided to offer insights into teacher trainees´ perspective of the blended learning experience at the University of Pardubice, Czech Republic.

  12. A Maximum Likelihood Estimation of Vocal-Tract-Related Filter Characteristics for Single Channel Speech Separation

    Directory of Open Access Journals (Sweden)

    Dansereau Richard M

    2007-01-01

    Full Text Available We present a new technique for separating two speech signals from a single recording. The proposed method bridges the gap between underdetermined blind source separation techniques and those techniques that model the human auditory system, that is, computational auditory scene analysis (CASA. For this purpose, we decompose the speech signal into the excitation signal and the vocal-tract-related filter and then estimate the components from the mixed speech using a hybrid model. We first express the probability density function (PDF of the mixed speech's log spectral vectors in terms of the PDFs of the underlying speech signal's vocal-tract-related filters. Then, the mean vectors of PDFs of the vocal-tract-related filters are obtained using a maximum likelihood estimator given the mixed signal. Finally, the estimated vocal-tract-related filters along with the extracted fundamental frequencies are used to reconstruct estimates of the individual speech signals. The proposed technique effectively adds vocal-tract-related filter characteristics as a new cue to CASA models using a new grouping technique based on an underdetermined blind source separation. We compare our model with both an underdetermined blind source separation and a CASA method. The experimental results show that our model outperforms both techniques in terms of SNR improvement and the percentage of crosstalk suppression.

  13. A Maximum Likelihood Estimation of Vocal-Tract-Related Filter Characteristics for Single Channel Speech Separation

    Directory of Open Access Journals (Sweden)

    Mohammad H. Radfar

    2006-11-01

    Full Text Available We present a new technique for separating two speech signals from a single recording. The proposed method bridges the gap between underdetermined blind source separation techniques and those techniques that model the human auditory system, that is, computational auditory scene analysis (CASA. For this purpose, we decompose the speech signal into the excitation signal and the vocal-tract-related filter and then estimate the components from the mixed speech using a hybrid model. We first express the probability density function (PDF of the mixed speech's log spectral vectors in terms of the PDFs of the underlying speech signal's vocal-tract-related filters. Then, the mean vectors of PDFs of the vocal-tract-related filters are obtained using a maximum likelihood estimator given the mixed signal. Finally, the estimated vocal-tract-related filters along with the extracted fundamental frequencies are used to reconstruct estimates of the individual speech signals. The proposed technique effectively adds vocal-tract-related filter characteristics as a new cue to CASA models using a new grouping technique based on an underdetermined blind source separation. We compare our model with both an underdetermined blind source separation and a CASA method. The experimental results show that our model outperforms both techniques in terms of SNR improvement and the percentage of crosstalk suppression.

  14. Sustained employability of workers in a production environment: design of a stepped wedge trial to evaluate effectiveness and cost-benefit of the POSE program.

    Science.gov (United States)

    van Holland, Berry J; de Boer, Michiel R; Brouwer, Sandra; Soer, Remko; Reneman, Michiel F

    2012-11-20

    Sustained employability and health are generating awareness of employers in an aging and more complex work force. To meet these needs, employers may offer their employees health surveillance programs, to increase opportunities to work on health and sustained employability. However, evidence for these health surveillance programs is lacking. The FLESH study (Functional Labour Evaluation for Sustained Health and employment) was developed to evaluate a comprehensive workers' health promotion program on its effectiveness, cost-benefit, and process of the intervention. The study is designed as a cluster randomised stepped wedge trial with randomisation at company plant level and is carried out in a large meat processing company. Every contracted employee is offered the opportunity to participate in the POSE program (Promotion Of Sustained Employability). The main goals of the POSE program are 1) providing employee's insight into their current employability and health status, 2) offering opportunities to improve employability and decrease health risks and 3) improving employability and health sustainably in order to keep them healthy at work. The program consists of a broad assessment followed by a counselling session and, if needed, a tailored intervention. Measurements will be performed at baseline and will be followed up at 20, 40, 60, 80, 106 and 132 weeks. The primary outcome measures are work ability, productivity and absenteeism. Secondary outcomes include health status, vitality, and psychosocial workload. A cost-benefit study will be conducted from the employers' perspective. A process evaluation will be conducted and the satisfaction of employer and employees with the program will be assessed. This study provides information on the effectiveness of the POSE program on sustained employment. When the program proves to be effective, employees benefit by improved work ability, and health. Employers benefit from healthier employees, reduced sick leave (costs) and

  15. Structural interface parameters are discriminatory in recognising near-native poses of protein-protein interactions.

    Directory of Open Access Journals (Sweden)

    Sony Malhotra

    Full Text Available Interactions at the molecular level in the cellular environment play a very crucial role in maintaining the physiological functioning of the cell. These molecular interactions exist at varied levels viz. protein-protein interactions, protein-nucleic acid interactions or protein-small molecules interactions. Presently in the field, these interactions and their mechanisms mark intensively studied areas. Molecular interactions can also be studied computationally using the approach named as Molecular Docking. Molecular docking employs search algorithms to predict the possible conformations for interacting partners and then calculates interaction energies. However, docking proposes number of solutions as different docked poses and hence offers a serious challenge to identify the native (or near native structures from the pool of these docked poses. Here, we propose a rigorous scoring scheme called DockScore which can be used to rank the docked poses and identify the best docked pose out of many as proposed by docking algorithm employed. The scoring identifies the optimal interactions between the two protein partners utilising various features of the putative interface like area, short contacts, conservation, spatial clustering and the presence of positively charged and hydrophobic residues. DockScore was first trained on a set of 30 protein-protein complexes to determine the weights for different parameters. Subsequently, we tested the scoring scheme on 30 different protein-protein complexes and native or near-native structure were assigned the top rank from a pool of docked poses in 26 of the tested cases. We tested the ability of DockScore to discriminate likely dimer interactions that differ substantially within a homologous family and also demonstrate that DOCKSCORE can distinguish correct pose for all 10 recent CAPRI targets.

  16. Pose and Wind Estimation for Autonomous Parafoils

    Science.gov (United States)

    2014-09-01

    Precision Airdrop System LIDAR light detection and ranging LOP line of position MCADS Maritime Craft Air Delivery System MEMS micro-electro-mechanical...least squares SLAM simultaneous localization and mapping SPS standard positioning service TIP Turn Initiation Point TMA target motion analysis TNT...improvements and further testing on the WindPack [45]. Most recently, Herrmann proposed the use of a ground-based lidar wind measurement system to transmit

  17. Personal privacy, information assurance, and the threat posed by malware techology

    Science.gov (United States)

    Stytz, Martin R.; Banks, Sheila B.

    2006-04-01

    In spite of our best efforts to secure the cyber world, the threats posed to personal privacy by attacks upon networks and software continue unabated. While there are many reasons for this state of affairs, clearly one of the reasons for continued vulnerabilities in software is the inability to assess their security properties and test their security systems while they are in development. A second reason for this growing threat to personal privacy is the growing sophistication and maliciousness of malware coupled with the increasing difficulty of detecting malware. The pervasive threat posed by malware coupled with the difficulties faced when trying to detect its presence or an attempted intrusion make addressing the malware threat one of the most pressing issues that must be solved in order to insure personal privacy to users of the internet. In this paper, we will discuss the threat posed by malware, the types of malware found in the wild (outside of computer laboratories), and current techniques that are available for from a successful malware penetration. The paper includes a discussion of anti-malware tools and suggestions for future anti-malware efforts.

  18. Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Geoffrey Ivan Scott

    2016-04-01

    Full Text Available ABSTRACTMonitoring programs have traditionally monitored legacy contaminants but are shifting focus to Contaminants of Emerging Concern (CECs. CECs present many challenges for monitoring and assessment, because measurement methods don't always exist nor have toxicological studies been fully conducted to place results in proper context. Also some CECs affect metabolic pathways to produce adverse outcomes that are not assessed through traditional toxicological evaluations. Antibiotics are CECs that pose significant environmental risks including development of both toxic effects at high doses and antibiotic resistance at doses well below the Minimum Inhibitory Concentration (MIC which kill bacteria and have been found in nearly half of all sites monitored in the US. Antimicrobial resistance has generally been attributed to the use of antibiotics in medicine for humans and livestock as well as aquaculture operations. The objective of this study was to assess the extent and magnitude of antibiotics in the environment and estimate their potential hazards in the environment. Antibiotics concentrations were measured in a number of monitoring studies which included Waste Water Treatment Plants (WWTP effluent, surface waters, sediments and biota. A number of studies reported levels of Antibiotic Resistant Microbes (ARM in surface waters and some studies found specific ARM genes (e.g. the blaM-1 gene in E. coli which may pose additional environmental risk. High levels of this gene were found to survive WWTP disinfection and accumulated in sediment at levels 100-1000 times higher than in the sewerage effluent, posing potential risks for gene transfer to other bacteria.in aquatic and marine ecosystems. Antibiotic risk assessment approaches were developed based on the use of MICs and MIC Ratios [High (Antibiotic Resistant/Low (Antibiotic Sensitive MIC] for each antibiotic indicating the range of bacterial adaptability to each antibiotic to help define the No

  19. Introduced organisms pose the most significant threat to the ...

    African Journals Online (AJOL)

    spamer

    Introduced organisms pose the most significant threat to the conservation status of oceanic islands (e.g.. Williamson 1996). Subantarctic Prince Edward Island, the smaller of the two islands in the Prince Edward. Island group, has few introduced organisms; it is cur- rently known to support only three introduced animals.

  20. Morozov-type discrepancy principle for nonlinear ill-posed problems ...

    Indian Academy of Sciences (India)

    For proving the existence of a regularization parameter under a Morozov-type discrepancy principle for Tikhonov regularization of nonlinear ill-posed problems, it is required to impose additional nonlinearity assumptions on the forward operator. Lipschitz continuity of the Freéchet derivative and requirement of the Lipschitz ...

  1. Morozov-type discrepancy principle for nonlinear ill-posed problems ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... For proving the existence of a regularization parameter under a Morozov-type discrepancy principle for Tikhonov regularization of nonlinear ill-posed problems, it is required to impose additional nonlinearity assumptions on the forward operator. Lipschitz continuity of the Freéchet derivative and requirement ...

  2. Estimating Single and Multiple Target Locations Using K-Means Clustering with Radio Tomographic Imaging in Wireless Sensor Networks

    Science.gov (United States)

    2015-03-26

    clustering is an algorithm that has been used in data mining applications such as machine learning applications , pattern recognition, hyper-spectral imagery...42 3.7.2 Application of K-means Clustering . . . . . . . . . . . . . . . . . 42 3.8 Experiment Design...Tomographic Imaging WLAN Wireless Local Area Networks WSN Wireless Sensor Network xx ESTIMATING SINGLE AND MULTIPLE TARGET LOCATIONS USING K-MEANS CLUSTERING

  3. Estimation of absolute microglial cell numbers in mouse fascia dentata using unbiased and efficient stereological cell counting principles

    DEFF Research Database (Denmark)

    Wirenfeldt, Martin; Dalmau, Ishar; Finsen, Bente

    2003-01-01

    Stereology offers a set of unbiased principles to obtain precise estimates of total cell numbers in a defined region. In terms of microglia, which in the traumatized and diseased CNS is an extremely dynamic cell population, the strength of stereology is that the resultant estimate is unaffected...... of microglia, although with this thickness, the intensity of the staining is too high to distinguish single cells. Lectin histochemistry does not visualize microglia throughout the section and, accordingly, is not suited for the optical fractionator. The mean total number of Mac-1+ microglial cells...... in the unilateral dentate gyrus of the normal young adult male C57BL/6 mouse was estimated to be 12,300 (coefficient of variation (CV)=0.13) with a mean coefficient of error (CE) of 0.06. The perspective of estimating microglial cell numbers using stereology is to establish a solid basis for studying the dynamics...

  4. Estimation of 131J-Jodohippurateclearance by a simplified method using a single plasma sample

    International Nuclear Information System (INIS)

    Botsch, H.; Golde, G.; Kampf, D.

    1980-01-01

    Theoretical volumes calculated from the reciprocal of the plasma concentration of 131 J-Jodohippurate were compared in 95 patients with clearance values calculated by the 2-compartment-method and in 18 patients with conventional PAH-clearance. For estimating Hippurate-clearance from a single blood sampling the most favorable time is 45 min. after injection (r = 0.96; clearance 400/ml/min.: r = 0.98). Clearance values may be derived from the formula: C = 0.4 + 7.26 V - 0.021 x V 2 (V = injected activity/activity per l plasma taken 45 min. after injection). The simplicity, precision and reproducibility of the above mentioned clearance-method is emphasized. (orig.) [de

  5. Microfluidic Impedance Flow Cytometry Enabling High-Throughput Single-Cell Electrical Property Characterization

    Science.gov (United States)

    Chen, Jian; Xue, Chengcheng; Zhao, Yang; Chen, Deyong; Wu, Min-Hsien; Wang, Junbo

    2015-01-01

    This article reviews recent developments in microfluidic impedance flow cytometry for high-throughput electrical property characterization of single cells. Four major perspectives of microfluidic impedance flow cytometry for single-cell characterization are included in this review: (1) early developments of microfluidic impedance flow cytometry for single-cell electrical property characterization; (2) microfluidic impedance flow cytometry with enhanced sensitivity; (3) microfluidic impedance and optical flow cytometry for single-cell analysis and (4) integrated point of care system based on microfluidic impedance flow cytometry. We examine the advantages and limitations of each technique and discuss future research opportunities from the perspectives of both technical innovation and clinical applications. PMID:25938973

  6. Economic Estimation of the Losses Caused by Surface Water Pollution Accidents in China From the Perspective of Water Bodies’ Functions

    Science.gov (United States)

    Yao, Hong; You, Zhen; Liu, Bo

    2016-01-01

    The number of surface water pollution accidents (abbreviated as SWPAs) has increased substantially in China in recent years. Estimation of economic losses due to SWPAs has been one of the focuses in China and is mentioned many times in the Environmental Protection Law of China promulgated in 2014. From the perspective of water bodies’ functions, pollution accident damages can be divided into eight types: damage to human health, water supply suspension, fishery, recreational functions, biological diversity, environmental property loss, the accident’s origin and other indirect losses. In the valuation of damage to people’s life, the procedure for compensation of traffic accidents in China was used. The functional replacement cost method was used in economic estimation of the losses due to water supply suspension and loss of water’s recreational functions. Damage to biological diversity was estimated by recovery cost analysis and damage to environmental property losses were calculated using pollutant removal costs. As a case study, using the proposed calculation procedure the economic losses caused by the major Songhuajiang River pollution accident that happened in China in 2005 have been estimated at 2263 billion CNY. The estimated economic losses for real accidents can sometimes be influenced by social and political factors, such as data authenticity and accuracy. Besides, one or more aspects in the method might be overestimated, underrated or even ignored. The proposed procedure may be used by decision makers for the economic estimation of losses in SWPAs. Estimates of the economic losses of pollution accidents could help quantify potential costs associated with increased risk sources along lakes/rivers but more importantly, highlight the value of clean water to society as a whole. PMID:26805869

  7. Economic Estimation of the Losses Caused by Surface Water Pollution Accidents in China From the Perspective of Water Bodies' Functions.

    Science.gov (United States)

    Yao, Hong; You, Zhen; Liu, Bo

    2016-01-22

    The number of surface water pollution accidents (abbreviated as SWPAs) has increased substantially in China in recent years. Estimation of economic losses due to SWPAs has been one of the focuses in China and is mentioned many times in the Environmental Protection Law of China promulgated in 2014. From the perspective of water bodies' functions, pollution accident damages can be divided into eight types: damage to human health, water supply suspension, fishery, recreational functions, biological diversity, environmental property loss, the accident's origin and other indirect losses. In the valuation of damage to people's life, the procedure for compensation of traffic accidents in China was used. The functional replacement cost method was used in economic estimation of the losses due to water supply suspension and loss of water's recreational functions. Damage to biological diversity was estimated by recovery cost analysis and damage to environmental property losses were calculated using pollutant removal costs. As a case study, using the proposed calculation procedure the economic losses caused by the major Songhuajiang River pollution accident that happened in China in 2005 have been estimated at 2263 billion CNY. The estimated economic losses for real accidents can sometimes be influenced by social and political factors, such as data authenticity and accuracy. Besides, one or more aspects in the method might be overestimated, underrated or even ignored. The proposed procedure may be used by decision makers for the economic estimation of losses in SWPAs. Estimates of the economic losses of pollution accidents could help quantify potential costs associated with increased risk sources along lakes/rivers but more importantly, highlight the value of clean water to society as a whole.

  8. Economic Estimation of the Losses Caused by Surface Water Pollution Accidents in China From the Perspective of Water Bodies’ Functions

    Directory of Open Access Journals (Sweden)

    Hong Yao

    2016-01-01

    Full Text Available The number of surface water pollution accidents (abbreviated as SWPAs has increased substantially in China in recent years. Estimation of economic losses due to SWPAs has been one of the focuses in China and is mentioned many times in the Environmental Protection Law of China promulgated in 2014. From the perspective of water bodies’ functions, pollution accident damages can be divided into eight types: damage to human health, water supply suspension, fishery, recreational functions, biological diversity, environmental property loss, the accident’s origin and other indirect losses. In the valuation of damage to people’s life, the procedure for compensation of traffic accidents in China was used. The functional replacement cost method was used in economic estimation of the losses due to water supply suspension and loss of water’s recreational functions. Damage to biological diversity was estimated by recovery cost analysis and damage to environmental property losses were calculated using pollutant removal costs. As a case study, using the proposed calculation procedure the economic losses caused by the major Songhuajiang River pollution accident that happened in China in 2005 have been estimated at 2263 billion CNY. The estimated economic losses for real accidents can sometimes be influenced by social and political factors, such as data authenticity and accuracy. Besides, one or more aspects in the method might be overestimated, underrated or even ignored. The proposed procedure may be used by decision makers for the economic estimation of losses in SWPAs. Estimates of the economic losses of pollution accidents could help quantify potential costs associated with increased risk sources along lakes/rivers but more importantly, highlight the value of clean water to society as a whole.

  9. Multifactor Analysis of Roadheader’s Body Pose Responses during the Horizontal Cutting Process

    Directory of Open Access Journals (Sweden)

    Kai Zong

    2018-01-01

    Full Text Available Based on the Lagrange equation in system dynamics, aiming at the horizontal cutting process, the dynamical coupling model of boom-type roadheader’s body pose was established. According to input problem of solving the model, a calculation method of the cutting head load was proposed, and the relationship between the cutting head load and pressure of the driving cylinders and swing angle of the cutting arm was obtained through simulating analysis. The simulation model was established to solve the dynamical coupling model. The cutting head load, horizontal swing angle of the cutting arm, and dip angle of coal seam were regarded as independent variables to perform changing parameter analysis in variations of the body pose. The field experiment was carried out, and the measured data is basically consistent with the simulation values. The results show that lateral displacement of the body can reach up to 6.5 cm, backward displacement can reach up to 5.2 cm, floor-based quantity can reach up to 11 cm, pitch angle of the body can reach up to 7.8°, and roll angle can reach up to 2.1°. Variations of the body pose parameters are influenced greatly by the cutting head load, while the influence from horizontal swing angle of the cutting arm and dip angle of coal seam is slighter. Among the pose parameters, floor-based quantity and pitch angle of the body vary relatively greatly, which tend to seriously influence forming quality of the roadway and should be mainly considered in deviation rectification of the roadheader’s body pose.

  10. A Simple Interface for 3D Position Estimation of a Mobile Robot with Single Camera.

    Science.gov (United States)

    Chao, Chun-Tang; Chung, Ming-Hsuan; Chiou, Juing-Shian; Wang, Chi-Jo

    2016-03-25

    In recent years, there has been an increase in the number of mobile robots controlled by a smart phone or tablet. This paper proposes a visual control interface for a mobile robot with a single camera to easily control the robot actions and estimate the 3D position of a target. In this proposal, the mobile robot employed an Arduino Yun as the core processor and was remote-controlled by a tablet with an Android operating system. In addition, the robot was fitted with a three-axis robotic arm for grasping. Both the real-time control signal and video transmission are transmitted via Wi-Fi. We show that with a properly calibrated camera and the proposed prototype procedures, the users can click on a desired position or object on the touchscreen and estimate its 3D coordinates in the real world by simple analytic geometry instead of a complicated algorithm. The results of the measurement verification demonstrates that this approach has great potential for mobile robots.

  11. Single-Arc IMRT?

    International Nuclear Information System (INIS)

    Bortfeld, Thomas; Webb, Steve

    2009-01-01

    The idea of delivering intensity-modulated radiation therapy (IMRT) with a multileaf collimator in a continuous dynamic mode during a single rotation of the gantry has recently gained momentum both in research and industry. In this note we investigate the potential of this Single-Arc IMRT technique at a conceptual level. We consider the original theoretical example case from Brahme et al that got the field of IMRT started. Using analytical methods, we derive deliverable intensity 'landscapes' for Single-Arc as well as standard IMRT and Tomotherapy. We find that Tomotherapy provides the greatest flexibility in shaping intensity landscapes and that it allows one to deliver IMRT in a way that comes close to the ideal case in the transverse plane. Single-Arc and standard IMRT make compromises in different areas. Only in relatively simple cases that do not require substantial intensity modulation will Single-Arc be dosimetrically comparable to Tomotherapy. Compared with standard IMRT, Single-Arc could be dosimetrically superior in certain cases if one is willing to accept the spreading of low dose values over large volumes of normal tissue. In terms of treatment planning, Single-Arc poses a more challenging optimization problem than Tomotherapy or standard IMRT. We conclude that Single-Arc holds potential as an efficient IMRT technique especially for relatively simple cases. In very complex cases, Single-Arc may unduly compromise the quality of the dose distribution, if one tries to keep the treatment time below 2 min or so. As with all IMRT techniques, it is important to explore the tradeoff between plan quality and the efficiency of its delivery carefully for each individual case. (note)

  12. A single-probe heat pulse method for estimating sap velocity in trees.

    Science.gov (United States)

    López-Bernal, Álvaro; Testi, Luca; Villalobos, Francisco J

    2017-10-01

    Available sap flow methods are still far from being simple, cheap and reliable enough to be used beyond very specific research purposes. This study presents and tests a new single-probe heat pulse (SPHP) method for monitoring sap velocity in trees using a single-probe sensor, rather than the multi-probe arrangements used up to now. Based on the fundamental conduction-convection principles of heat transport in sapwood, convective velocity (V h ) is estimated from the temperature increase in the heater after the application of a heat pulse (ΔT). The method was validated against measurements performed with the compensation heat pulse (CHP) technique in field trees of six different species. To do so, a dedicated three-probe sensor capable of simultaneously applying both methods was produced and used. Experimental measurements in the six species showed an excellent agreement between SPHP and CHP outputs for moderate to high flow rates, confirming the applicability of the method. In relation to other sap flow methods, SPHP presents several significant advantages: it requires low power inputs, it uses technically simpler and potentially cheaper instrumentation, the physical damage to the tree is minimal and artefacts caused by incorrect probe spacing and alignment are removed. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  13. Plant DNA barcodes can accurately estimate species richness in poorly known floras.

    Science.gov (United States)

    Costion, Craig; Ford, Andrew; Cross, Hugh; Crayn, Darren; Harrington, Mark; Lowe, Andrew

    2011-01-01

    Widespread uptake of DNA barcoding technology for vascular plants has been slow due to the relatively poor resolution of species discrimination (∼70%) and low sequencing and amplification success of one of the two official barcoding loci, matK. Studies to date have mostly focused on finding a solution to these intrinsic limitations of the markers, rather than posing questions that can maximize the utility of DNA barcodes for plants with the current technology. Here we test the ability of plant DNA barcodes using the two official barcoding loci, rbcLa and matK, plus an alternative barcoding locus, trnH-psbA, to estimate the species diversity of trees in a tropical rainforest plot. Species discrimination accuracy was similar to findings from previous studies but species richness estimation accuracy proved higher, up to 89%. All combinations which included the trnH-psbA locus performed better at both species discrimination and richness estimation than matK, which showed little enhanced species discriminatory power when concatenated with rbcLa. The utility of the trnH-psbA locus is limited however, by the occurrence of intraspecific variation observed in some angiosperm families to occur as an inversion that obscures the monophyly of species. We demonstrate for the first time, using a case study, the potential of plant DNA barcodes for the rapid estimation of species richness in taxonomically poorly known areas or cryptic populations revealing a powerful new tool for rapid biodiversity assessment. The combination of the rbcLa and trnH-psbA loci performed better for this purpose than any two-locus combination that included matK. We show that although DNA barcodes fail to discriminate all species of plants, new perspectives and methods on biodiversity value and quantification may overshadow some of these shortcomings by applying barcode data in new ways.

  14. Evaluating EIV, OLS, and SEM Estimators of Group Slope Differences in the Presence of Measurement Error: The Single-Indicator Case

    Science.gov (United States)

    Culpepper, Steven Andrew

    2012-01-01

    Measurement error significantly biases interaction effects and distorts researchers' inferences regarding interactive hypotheses. This article focuses on the single-indicator case and shows how to accurately estimate group slope differences by disattenuating interaction effects with errors-in-variables (EIV) regression. New analytic findings were…

  15. Morozov-type discrepancy principle for nonlinear ill-posed problems ...

    Indian Academy of Sciences (India)

    [3] Engl H W, Kunisch K and Neubauer A, Convergence rates for Tikhonov regularization of nonliner problems, Inverse Problems 5 (1989) 523–540. [4] Hanke M, Neubauer A and Scherzer O, A convergence analysis of Landweber iteration for nonlinear ill-posed problems, Numer. Math. 72 (1995) 21–37. [5] Hofmann B and ...

  16. Enhancing Students' Communication Skills through Problem Posing and Presentation

    Science.gov (United States)

    Sugito; E. S., Sri Mulyani; Hartono; Supartono

    2017-01-01

    This study was to explore how enhance communication skill through problem posing and presentation method. The subjects of this research were the seven grade students Junior High School, including 20 male and 14 female. This research was conducted in two cycles and each cycle consisted of four steps, they were: planning, action, observation, and…

  17. Sparse deconvolution for the large-scale ill-posed inverse problem of impact force reconstruction

    Science.gov (United States)

    Qiao, Baijie; Zhang, Xingwu; Gao, Jiawei; Liu, Ruonan; Chen, Xuefeng

    2017-01-01

    Most previous regularization methods for solving the inverse problem of force reconstruction are to minimize the l2-norm of the desired force. However, these traditional regularization methods such as Tikhonov regularization and truncated singular value decomposition, commonly fail to solve the large-scale ill-posed inverse problem in moderate computational cost. In this paper, taking into account the sparse characteristic of impact force, the idea of sparse deconvolution is first introduced to the field of impact force reconstruction and a general sparse deconvolution model of impact force is constructed. Second, a novel impact force reconstruction method based on the primal-dual interior point method (PDIPM) is proposed to solve such a large-scale sparse deconvolution model, where minimizing the l2-norm is replaced by minimizing the l1-norm. Meanwhile, the preconditioned conjugate gradient algorithm is used to compute the search direction of PDIPM with high computational efficiency. Finally, two experiments including the small-scale or medium-scale single impact force reconstruction and the relatively large-scale consecutive impact force reconstruction are conducted on a composite wind turbine blade and a shell structure to illustrate the advantage of PDIPM. Compared with Tikhonov regularization, PDIPM is more efficient, accurate and robust whether in the single impact force reconstruction or in the consecutive impact force reconstruction.

  18. 3D Facial Landmarking under Expression, Pose, and Occlusion Variations

    NARCIS (Netherlands)

    H. Dibeklioğ lu; A.A. Salah (Albert Ali); L. Akarun

    2008-01-01

    htmlabstractAutomatic localization of 3D facial features is important for face recognition, tracking, modeling and expression analysis. Methods developed for 2D images were shown to have problems working across databases acquired with different illumination conditions. Expression variations, pose

  19. Did Buddha turn the other cheek too? A comparison of posing biases between Jesus and Buddha.

    Science.gov (United States)

    Duerksen, Kari N; Friedrich, Trista E; Elias, Lorin J

    2015-10-02

    People tend to exhibit a leftward bias in posing. Various studies suggest that posing to the left portrays a stronger emotion, whereas posing to the right portrays a more neutral emotion. Religions such as Christianity emphasize the role of strong emotions in religious experience, whereas religions such as Buddhism emphasize the calming of emotions as being important. In the present study, we investigated if the emphasis on emotionality of a religion influences the depiction of their religious figures. Specifically, we coded 484 paintings of Jesus and Buddha from online art databases for whether the deity exhibited a left bias, right bias, or central face presentation. The posing biases were analysed to discover whether paintings of Jesus would more frequently depict a leftward bias than paintings of Buddha. Jesus is more commonly depicted with a leftward bias than Buddha, and Buddha is more commonly depicted with a central face presentation than Jesus. These findings support the idea that the amount of emotionality that is to be conveyed in artwork influences the whether the subject is posed with a leftward bias.

  20. Single-Channel Blind Estimation of Reverberation Parameters

    DEFF Research Database (Denmark)

    Doire, C.S.J.; Brookes, M. D.; Naylor, P. A.

    2015-01-01

    The reverberation of an acoustic channel can be characterised by two frequency-dependent parameters: the reverberation time and the direct-to-reverberant energy ratio. This paper presents an algorithm for blindly determining these parameters from a single-channel speech signal. The algorithm uses...

  1. Estimating the Relative Water Content of Single Leaves from Optical Polarization Measurements

    Science.gov (United States)

    Vanderbilt, Vern; Daughtry, Craig; Dahlgren, Robert

    2016-01-01

    Remotely sensing the water status of plants and the water content of canopies remain long-term goals of remote sensing research. For monitoring canopy water status, existing approaches such as the Crop Water Stress Index and the Equivalent Water Thickness have limitations. The CWSI does not work well in humid regions, requires estimates of the vapor pressure deficit near the canopy during the remote sensing over-flight and, once stomata close, provides little information regarding the canopy water status. The EWI is based upon the physics of water-light interaction, not plant physiology. In this research, we applied optical polarization techniques to monitor the VISNIR light reflected from the leaf interior, R, as well as the leaf transmittance, T, as the relative water content (RWC) of corn (Zea mays) leaves decreased. Our results show that R and T both changed nonlinearly as each leaf dried, R increasing and T decreasing. Our results tie changes in the VISNIR R and T to leaf physiological changes linking the light scattered out of the drying leaf interior to its relative water content and to changes in leaf cellular structure and pigments. Our results suggest remotely sensing the physiological water status of a single leaf and perhaps of a plant canopy might be possible in the future. However, using our approach to estimate the water status of a leaf does not appear possible at present, because our results display too much variability that we do not yet understand.

  2. Longitudinal Single-Bunch Instability in the ILC Damping Rings: Estimate of Current Threshold

    International Nuclear Information System (INIS)

    Venturini, Marco; Venturini, Marco

    2008-01-01

    Characterization of single-bunch instabilities in the International Linear Collider (ILC) damping rings (DRs) has been indicated as a high-priority activity toward completion of an engineering design. In this paper we report on a first estimate of the current thresholds for the instability using numerical and analytical models of the wake potentials associated with the various machine components. The numerical models were derived (upon appropriate scaling) from designs of the corresponding components installed in existing machines. The current thresholds for instabilities were determined by numerical solution of the Vlasov equation for the longitudinal dynamics. For the DR baseline lattice as of Feb. 2007 we find the critical current for instability to be safely above the design specifications leaving room for further optimization of the choice of the momentum compaction

  3. Sequential estimation of intrinsic activity and synaptic input in single neurons by particle filtering with optimal importance density

    Science.gov (United States)

    Closas, Pau; Guillamon, Antoni

    2017-12-01

    This paper deals with the problem of inferring the signals and parameters that cause neural activity to occur. The ultimate challenge being to unveil brain's connectivity, here we focus on a microscopic vision of the problem, where single neurons (potentially connected to a network of peers) are at the core of our study. The sole observation available are noisy, sampled voltage traces obtained from intracellular recordings. We design algorithms and inference methods using the tools provided by stochastic filtering that allow a probabilistic interpretation and treatment of the problem. Using particle filtering, we are able to reconstruct traces of voltages and estimate the time course of auxiliary variables. By extending the algorithm, through PMCMC methodology, we are able to estimate hidden physiological parameters as well, like intrinsic conductances or reversal potentials. Last, but not least, the method is applied to estimate synaptic conductances arriving at a target cell, thus reconstructing the synaptic excitatory/inhibitory input traces. Notably, the performance of these estimations achieve the theoretical lower bounds even in spiking regimes.

  4. Control and System Theory, Optimization, Inverse and Ill-Posed Problems

    Science.gov (United States)

    1988-09-14

    Justlfleatlen Distribut ion/ Availability Codes # AFOSR-87-0350 Avat’ and/or1987-1988 Dist Special *CONTROL AND SYSTEM THEORY , ~ * OPTIMIZATION, * INVERSE...considerable va- riety of research investigations within the grant areas (Control and system theory , Optimization, and Ill-posed problems]. The

  5. Estimation of mechanical properties of single wall carbon nanotubes ...

    Indian Academy of Sciences (India)

    Molecular mechanics; single wall carbon nanotube; mechanical proper- ... Fracture Mechanics); Rossi & Meo 2009). Furthermore, the work carried out by Natsuki & Endo. (2004), Xiao et al (2005) and Sun & Zhao (2005) in the direction of ..... Jin Y and Yuan F G 2003 Simulation of elastic properties of single walled carbon ...

  6. A population-based Bayesian approach to the minimal model of glucose and insulin homeostasis

    DEFF Research Database (Denmark)

    Andersen, Kim Emil; Højbjerre, Malene

    2005-01-01

    -posed estimation problem, where the reconstruction most often has been done by non-linear least squares techniques separately for each entity. The minmal model was originally specified for a single individual and does not combine several individuals with the advantage of estimating the metabolic portrait...... to a population-based model. The estimation of the parameters are efficiently implemented in a Bayesian approach where posterior inference is made through the use of Markov chain Monte Carlo techniques. Hereby we obtain a powerful and flexible modelling framework for regularizing the ill-posed estimation problem...

  7. Estimating the cost of blood: past, present, and future directions.

    Science.gov (United States)

    Shander, Aryeh; Hofmann, Axel; Gombotz, Hans; Theusinger, Oliver M; Spahn, Donat R

    2007-06-01

    Understanding the costs associated with blood products requires sophisticated knowledge about transfusion medicine and is attracting the attention of clinical and administrative healthcare sectors worldwide. To improve outcomes, blood usage must be optimized and expenditures controlled so that resources may be channeled toward other diagnostic, therapeutic, and technological initiatives. Estimating blood costs, however, is a complex undertaking, surpassing simple supply versus demand economics. Shrinking donor availability and application of a precautionary principle to minimize transfusion risks are factors that continue to drive the cost of blood products upward. Recognizing that historical accounting attempts to determine blood costs have varied in scope, perspective, and methodology, new approaches have been initiated to identify all potential cost elements related to blood and blood product administration. Activities are also under way to tie these elements together in a comprehensive and practical model that will be applicable to all single-donor blood products without regard to practice type (e.g., academic, private, multi- or single-center clinic). These initiatives, their rationale, importance, and future directions are described.

  8. ULTOR(Registered TradeMark) Passive Pose and Position Engine For Spacecraft Relative Navigation

    Science.gov (United States)

    Hannah, S. Joel

    2008-01-01

    The ULTOR(Registered TradeMark) Passive Pose and Position Engine (P3E) technology, developed by Advanced Optical Systems, Inc (AOS), uses real-time image correlation to provide relative position and pose data for spacecraft guidance, navigation, and control. Potential data sources include a wide variety of sensors, including visible and infrared cameras. ULTOR(Registered TradeMark) P3E has been demonstrated on a number of host processing platforms. NASA is integrating ULTOR(Registerd TradeMark) P3E into its Relative Navigation System (RNS), which is being developed for the upcoming Hubble Space Telescope (HST) Servicing Mission 4 (SM4). During SM4 ULTOR(Registered TradeMark) P3E will perform realtime pose and position measurements during both the approach and departure phases of the mission. This paper describes the RNS implementation of ULTOR(Registered TradeMark) P3E, and presents results from NASA's hardware-in-the-loop simulation testing against the HST mockup.

  9. A problem-posing approach to teaching the topic of radioactivity

    NARCIS (Netherlands)

    Klaassen, C.W.J.M.

    1995-01-01

    This thesis highlights a problem-posing approach to science education. By this is meant an approach that explicitly aims at providing students with content-related motives for extending their existing conceptual resources, experiential base and belief system in a certain direction, such that a

  10. Effects of pose and image resolution on automatic face recognition

    NARCIS (Netherlands)

    Mahmood, Zahid; Ali, Tauseef; Khan, Samee U.

    The popularity of face recognition systems have increased due to their use in widespread applications. Driven by the enormous number of potential application domains, several algorithms have been proposed for face recognition. Face pose and image resolutions are among the two important factors that

  11. Regularization theory for ill-posed problems selected topics

    CERN Document Server

    Lu, Shuai

    2013-01-01

    Thismonograph is a valuable contribution to thehighly topical and extremly productive field ofregularisationmethods for inverse and ill-posed problems. The author is an internationally outstanding and acceptedmathematicianin this field. In his book he offers a well-balanced mixtureof basic and innovative aspects.He demonstrates new,differentiatedviewpoints, and important examples for applications. The bookdemontrates thecurrent developments inthe field of regularization theory,such as multiparameter regularization and regularization in learning theory. The book is written for graduate and PhDs

  12. The influence of the design matrix on treatment effect estimates in the quantitative analyses of single-subject experimental design research.

    Science.gov (United States)

    Moeyaert, Mariola; Ugille, Maaike; Ferron, John M; Beretvas, S Natasha; Van den Noortgate, Wim

    2014-09-01

    The quantitative methods for analyzing single-subject experimental data have expanded during the last decade, including the use of regression models to statistically analyze the data, but still a lot of questions remain. One question is how to specify predictors in a regression model to account for the specifics of the design and estimate the effect size of interest. These quantitative effect sizes are used in retrospective analyses and allow synthesis of single-subject experimental study results which is informative for evidence-based decision making, research and theory building, and policy discussions. We discuss different design matrices that can be used for the most common single-subject experimental designs (SSEDs), namely, the multiple-baseline designs, reversal designs, and alternating treatment designs, and provide empirical illustrations. The purpose of this article is to guide single-subject experimental data analysts interested in analyzing and meta-analyzing SSED data. © The Author(s) 2014.

  13. A single model procedure for estimating tank calibration equations

    International Nuclear Information System (INIS)

    Liebetrau, A.M.

    1997-10-01

    A fundamental component of any accountability system for nuclear materials is a tank calibration equation that relates the height of liquid in a tank to its volume. Tank volume calibration equations are typically determined from pairs of height and volume measurements taken in a series of calibration runs. After raw calibration data are standardized to a fixed set of reference conditions, the calibration equation is typically fit by dividing the data into several segments--corresponding to regions in the tank--and independently fitting the data for each segment. The estimates obtained for individual segments must then be combined to obtain an estimate of the entire calibration function. This process is tedious and time-consuming. Moreover, uncertainty estimates may be misleading because it is difficult to properly model run-to-run variability and between-segment correlation. In this paper, the authors describe a model whose parameters can be estimated simultaneously for all segments of the calibration data, thereby eliminating the need for segment-by-segment estimation. The essence of the proposed model is to define a suitable polynomial to fit to each segment and then extend its definition to the domain of the entire calibration function, so that it (the entire calibration function) can be expressed as the sum of these extended polynomials. The model provides defensible estimates of between-run variability and yields a proper treatment of between-segment correlations. A portable software package, called TANCS, has been developed to facilitate the acquisition, standardization, and analysis of tank calibration data. The TANCS package was used for the calculations in an example presented to illustrate the unified modeling approach described in this paper. With TANCS, a trial calibration function can be estimated and evaluated in a matter of minutes

  14. Remaining useful life estimation for deteriorating systems with time-varying operational conditions and condition-specific failure zones

    Directory of Open Access Journals (Sweden)

    Li Qi

    2016-06-01

    Full Text Available Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life (RUL for the deteriorating systems. This paper presents a method based on probabilistic and stochastic approaches to estimate system RUL for periodically monitored degradation processes with dynamic time-varying operational conditions and condition-specific failure zones. The method assumes that the degradation rate is influenced by specific operational condition and moreover, the transition between different operational conditions plays the most important role in affecting the degradation process. These operational conditions are assumed to evolve as a discrete-time Markov chain (DTMC. The failure thresholds are also determined by specific operational conditions and described as different failure zones. The 2008 PHM Conference Challenge Data is utilized to illustrate our method, which contains mass sensory signals related to the degradation process of a commercial turbofan engine. The RUL estimation method using the sensor measurements of a single sensor was first developed, and then multiple vital sensors were selected through a particular optimization procedure in order to increase the prediction accuracy. The effectiveness and advantages of the proposed method are presented in a comparison with existing methods for the same dataset.

  15. Extrinsic Parameter Calibration for Line Scanning Cameras on Ground Vehicles with Navigation Systems Using a Calibration Pattern

    Directory of Open Access Journals (Sweden)

    Alexander Wendel

    2017-10-01

    Full Text Available Line scanning cameras, which capture only a single line of pixels, have been increasingly used in ground based mobile or robotic platforms. In applications where it is advantageous to directly georeference the camera data to world coordinates, an accurate estimate of the camera’s 6D pose is required. This paper focuses on the common case where a mobile platform is equipped with a rigidly mounted line scanning camera, whose pose is unknown, and a navigation system providing vehicle body pose estimates. We propose a novel method that estimates the camera’s pose relative to the navigation system. The approach involves imaging and manually labelling a calibration pattern with distinctly identifiable points, triangulating these points from camera and navigation system data and reprojecting them in order to compute a likelihood, which is maximised to estimate the 6D camera pose. Additionally, a Markov Chain Monte Carlo (MCMC algorithm is used to estimate the uncertainty of the offset. Tested on two different platforms, the method was able to estimate the pose to within 0.06 m/1.05 ∘ and 0.18 m/2.39 ∘ . We also propose several approaches to displaying and interpreting the 6D results in a human readable way.

  16. A Simple Interface for 3D Position Estimation of a Mobile Robot with Single Camera

    Directory of Open Access Journals (Sweden)

    Chun-Tang Chao

    2016-03-01

    Full Text Available In recent years, there has been an increase in the number of mobile robots controlled by a smart phone or tablet. This paper proposes a visual control interface for a mobile robot with a single camera to easily control the robot actions and estimate the 3D position of a target. In this proposal, the mobile robot employed an Arduino Yun as the core processor and was remote-controlled by a tablet with an Android operating system. In addition, the robot was fitted with a three-axis robotic arm for grasping. Both the real-time control signal and video transmission are transmitted via Wi-Fi. We show that with a properly calibrated camera and the proposed prototype procedures, the users can click on a desired position or object on the touchscreen and estimate its 3D coordinates in the real world by simple analytic geometry instead of a complicated algorithm. The results of the measurement verification demonstrates that this approach has great potential for mobile robots.

  17. Sustained employability of workers in a production environment: design of a stepped wedge trial to evaluate effectiveness and cost-benefit of the POSE program

    Directory of Open Access Journals (Sweden)

    van Holland Berry J

    2012-11-01

    Full Text Available Abstract Background Sustained employability and health are generating awareness of employers in an aging and more complex work force. To meet these needs, employers may offer their employees health surveillance programs, to increase opportunities to work on health and sustained employability. However, evidence for these health surveillance programs is lacking. The FLESH study (Functional Labour Evaluation for Sustained Health and employment was developed to evaluate a comprehensive workers’ health promotion program on its effectiveness, cost-benefit, and process of the intervention. Methods The study is designed as a cluster randomised stepped wedge trial with randomisation at company plant level and is carried out in a large meat processing company. Every contracted employee is offered the opportunity to participate in the POSE program (Promotion Of Sustained Employability. The main goals of the POSE program are 1 providing employee’s insight into their current employability and health status, 2 offering opportunities to improve employability and decrease health risks and 3 improving employability and health sustainably in order to keep them healthy at work. The program consists of a broad assessment followed by a counselling session and, if needed, a tailored intervention. Measurements will be performed at baseline and will be followed up at 20, 40, 60, 80, 106 and 132 weeks. The primary outcome measures are work ability, productivity and absenteeism. Secondary outcomes include health status, vitality, and psychosocial workload. A cost-benefit study will be conducted from the employers’ perspective. A process evaluation will be conducted and the satisfaction of employer and employees with the program will be assessed. Discussion This study provides information on the effectiveness of the POSE program on sustained employment. When the program proves to be effective, employees benefit by improved work ability, and health. Employers benefit

  18. PRA has many faces - can the safety goal be well-posed

    International Nuclear Information System (INIS)

    Bargmann, H.

    1983-01-01

    The question is discussed whether probabilistic reliability problems can, principally, be well-posed in practical situations. The problem is reduced to the question whether an underlying probabilistic experiment which is, essentially, the set of outcomes can be precisely specified such that the solution of the problem is unique. Upon reexamination of a classical paradox due to Bertrand and consideration of a typical problem of structural reliability we conclude that the possibility of well-posing a reliability problem should be considered illusory, for fundamental reasons which are inherent in practical situations. In particular, it should not be assumed that a quantitative safety goal could be verified. Generally, a probabilistic assessment should be considered as a quantitative method for establishing rational results which should, however, not be viewed as quantitative measures but as qualitative guides

  19. Pose Measurement Method and Experiments for High-Speed Rolling Targets in a Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Zhenyuan Jia

    2014-12-01

    Full Text Available High-precision wind tunnel simulation tests play an important role in aircraft design and manufacture. In this study, a high-speed pose vision measurement method is proposed for high-speed and rolling targets in a supersonic wind tunnel. To obtain images with high signal-to-noise ratio and avoid impacts on the aerodynamic shape of the rolling targets, a high-speed image acquisition method based on ultrathin retro-reflection markers is presented. Since markers are small-sized and some of them may be lost when the target is rolling, a novel markers layout with which markers are distributed evenly on the surface is proposed based on a spatial coding method to achieve highly accurate pose information. Additionally, a pose acquisition is carried out according to the mentioned markers layout after removing mismatching points by Case Deletion Diagnostics. Finally, experiments on measuring the pose parameters of high-speed targets in the laboratory and in a supersonic wind tunnel are conducted to verify the feasibility and effectiveness of the proposed method. Experimental results indicate that the position measurement precision is less than 0.16 mm, the pitching and yaw angle precision less than 0.132° and the roll angle precision 0.712°.

  20. Pose measurement method and experiments for high-speed rolling targets in a wind tunnel.

    Science.gov (United States)

    Jia, Zhenyuan; Ma, Xin; Liu, Wei; Lu, Wenbo; Li, Xiao; Chen, Ling; Wang, Zhengqu; Cui, Xiaochun

    2014-12-12

    High-precision wind tunnel simulation tests play an important role in aircraft design and manufacture. In this study, a high-speed pose vision measurement method is proposed for high-speed and rolling targets in a supersonic wind tunnel. To obtain images with high signal-to-noise ratio and avoid impacts on the aerodynamic shape of the rolling targets, a high-speed image acquisition method based on ultrathin retro-reflection markers is presented. Since markers are small-sized and some of them may be lost when the target is rolling, a novel markers layout with which markers are distributed evenly on the surface is proposed based on a spatial coding method to achieve highly accurate pose information. Additionally, a pose acquisition is carried out according to the mentioned markers layout after removing mismatching points by Case Deletion Diagnostics. Finally, experiments on measuring the pose parameters of high-speed targets in the laboratory and in a supersonic wind tunnel are conducted to verify the feasibility and effectiveness of the proposed method. Experimental results indicate that the position measurement precision is less than 0.16 mm, the pitching and yaw angle precision less than 0.132° and the roll angle precision 0.712°.

  1. Estimates of ambient groundwater velocity in the alluvium south of Yucca Mountain from single-well tracer tests

    International Nuclear Information System (INIS)

    Reimus, P.W.; Umari, M.J.; Roback, R.; Earle, John; Darnell, Jon; Farnham, Irene

    2002-01-01

    The saturated alluvium located south of Yucca Mountain, Nevada is expected to serve as the final barrier to radionuclide transport from the proposed high-level nuclear waste repository at Yucca Mountain. The alluvium will act as a barrier if radionuclides breach the engineered barriers in the repository, move through the unsaturated zone beneath the repository to the water table, and then migrate through saturated volcanic tuffs to the alluvium. Three single-well injection-withdrawal tracer tests were conducted between December 2000 and April 2001 in the saturated alluviuni at NC-EWDP-19D1, a Nye County-Early Warning Drilling Program well located about 18 km south of Yucca Mountain. The tests had the objectives of (1) distinguishing between a single- and a dual-porosity conceptual radionuclide transport model for the alluvium, and (2) obtaining estimates of ambient groundwater velocity in the alluvium.

  2. Segmental Bayesian estimation of gap-junctional and inhibitory conductance of inferior olive neurons from spike trains with complicated dynamics

    Directory of Open Access Journals (Sweden)

    Huu eHoang

    2015-05-01

    Full Text Available The inverse problem for estimating model parameters from brain spike data is an ill-posed problem because of a huge mismatch in the system complexity between the model and the brain as well as its non-stationary dynamics, and needs a stochastic approach that finds the most likely solution among many possible solutions. In the present study, we developed a segmental Bayesian method to estimate the two parameters of interest, the gap-junctional (gc and inhibitory conductance (gi from inferior olive spike data. Feature vectors were estimated for the spike data in a segment-wise fashion to compensate for the non-stationary firing dynamics. Hierarchical Bayesian estimation was conducted to estimate the gc and gi for every spike segment using a forward model constructed in the principal component analysis (PCA space of the feature vectors, and to merge the segmental estimates into single estimates for every neuron. The segmental Bayesian estimation gave smaller fitting errors than the conventional Bayesian inference, which finds the estimates once across the entire spike data, or the minimum error method, which directly finds the closest match in the PCA space. The segmental Bayesian inference has the potential to overcome the problem of non-stationary dynamics and resolve the ill-posedness of the inverse problem because of the mismatch between the model and the brain under the constraints based, and it is a useful tool to evaluate parameters of interest for neuroscience from experimental spike train data.

  3. Mathematical Thinking and Creativity through Mathematical Problem Posing and Solving

    Science.gov (United States)

    Ayllón, María F.; Gómez, Isabel A.; Ballesta-Claver, Julio

    2016-01-01

    This work shows the relationship between the development of mathematical thinking and creativity with mathematical problem posing and solving. Creativity and mathematics are disciplines that do not usually appear together. Both concepts constitute complex processes sharing elements, such as fluency (number of ideas), flexibility (range of ideas),…

  4. Kinematic Measurement of Knee Prosthesis from Single-Plane Projection Images

    Science.gov (United States)

    Hirokawa, Shunji; Ariyoshi, Shogo; Takahashi, Kenji; Maruyama, Koichi

    In this paper, the measurement of 3D motion from 2D perspective projections of knee prosthesis is described. The technique reported by Banks and Hodge was further developed in this study. The estimation was performed in two steps. The first-step estimation was performed on the assumption of orthogonal projection. Then, the second-step estimation was subsequently carried out based upon the perspective projection to accomplish more accurate estimation. The simulation results have demonstrated that the technique archived sufficient accuracies of position/orientation estimation for prosthetic kinematics. Then we applied our algorithm to the CCD images, thereby examining the influences of various artifacts, possibly incorporated through an imaging process, on the estimation accuracies. We found that accuracies in the experiment were influenced mainly by the geometric discrepancies between the prosthesis component and computer generated model and by the spacial inconsistencies between the coordinate axes of the positioner and that of the computer model. However, we verified that our algorithm could achieve proper and consistent estimation even for the CCD images.

  5. Decision From Indecision: Conservation of Thangka Significance, Perspectives and Approaches

    Directory of Open Access Journals (Sweden)

    Jacinta Boon Nee Loh

    2002-11-01

    Full Text Available Art may be entwined with religion, encompassing a spiritual message beyond artistic form and design. The thangka is one such sacred art in this world. Each thangka is created for a specific purpose and will always be different from other ones. It is for this reason and other values that they are conserved for the present and the future. The thangka poses complex challenges for conservators because of its composite nature and the wealth of values it embodies. It demands a balanced approach that looks into its material and conceptual integrity. Each of us has different aesthetic standards in interpretation of the thangka. This research explores the approaches and perspectives of thangka conservation, in particular embroidered/ appliqué thangkas and the influence of their significance in the decision-making process of their conservation. Through this investigation, the author establishes a framework of decision-making and her perspectives to thangka conservation.

  6. A novel method to estimate the impact parameter on a drift cell by using the information of single ionization clusters

    Energy Technology Data Exchange (ETDEWEB)

    Signorelli, G., E-mail: giovanni.signorelli@pi.infn.it [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); D' Onofrio, A. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Università di Pisa, Dipartimento di Fisica, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Venturini, M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy)

    2016-07-11

    Measuring the time of each ionization cluster in drift chambers has been proposed to improve the single hit resolution, especially for very low mass tracking systems. Ad hoc formulae have been developed to combine the information from the single clusters. We show that the problem falls in a wide category of problems that can be solved with an algorithm called Maximum Possible Spacing (MPS) which has been demonstrated to find the optimal estimator. We show that the MPS approach is applicable and gives the expected results. Its application in a real tracking device, namely the MEG II cylindrical drift chamber, is discussed.

  7. Parameters estimation of the single and double diode photovoltaic models using a Gauss–Seidel algorithm and analytical method: A comparative study

    International Nuclear Information System (INIS)

    Et-torabi, K.; Nassar-eddine, I.; Obbadi, A.; Errami, Y.; Rmaily, R.; Sahnoun, S.; El fajri, A.; Agunaou, M.

    2017-01-01

    Highlights: • Comparative study of two methods: a Gauss Seidel method and an analytical method. • Five models are implemented to estimate the five parameters for single diode. • Two models are used to estimate the seven parameters for double diode. • The parameters are estimated under changing environmental conditions. • To choose method/model combination more adequate for each PV module technology. - Abstract: In the photovoltaic (PV) panels modeling field, this paper presents a comparative study of two parameter estimation methods: the iterative method called Gauss Seidel, applied on the single diode model, and the analytical method used on the double diode model. These parameter estimation methods are based on the manufacturer's datasheets. They are also tested on three PV modules of different technologies: multicrystalline (kyocera KC200GT), monocrystalline (Shell SQ80), and thin film (Shell ST40). For the iterative method, five existing mathematical models classified from 1 to 5 are used to estimate the parameters of these PV modules under varying environmental conditions. Only two models of them are used for the analytical method. Each model is based on the combination of the photocurrent and the reverse saturation current’s expressions in terms of temperature and irradiance. In addition, the results of the models’ simulation are compared with the experimental data obtained from the PV modules’ datasheets, in order to evaluate the accuracy of the models. The simulation shows that the I-V characteristics obtained are matching to the experimental data. In order to validate the reliability of the two methods, both the Absolute Error (AE) and the Root Mean Square Error (RMSE) were calculated. The results suggest that the analytical method can be very useful for monocrystalline and multicrystalline modules, but for the thin film module, the iterative method is the most suitable.

  8. Geophysical Tools, Challenges and Perspectives Related to Natural Hazards, Climate Change and Food Security

    Science.gov (United States)

    Fucugauchi, J. U.

    2013-05-01

    In the coming decades a changing climate and natural hazards will likely increase the vulnerability of agricultural and other food production infrastructures, posing increasing treats to industrialized and developing economies. While food security concerns affect us globally, the huge differences among countries in stocks, population size, poverty levels, economy, technologic development, transportation, health care systems and basic infrastructure will pose a much larger burden on populations in the developing and less developed world. In these economies, increase in the magnitude, duration and frequency of droughts, floods, hurricanes, rising sea levels, heat waves, thunderstorms, freezing events and other phenomena will pose severe costs on the population. For this presentation, we concentrate on a geophysical perspective of the problems, tools available, challenges and short and long-term perspectives. In many instances, a range of natural hazards are considered as unforeseen catastrophes, which suddenly affect without warning, resulting in major losses. Although the forecasting capacity in the different situations arising from climate change and natural hazards is still limited, there are a range of tools available to assess scenarios and forecast models for developing and implementing better mitigation strategies and prevention programs. Earth observation systems, geophysical instrumental networks, satellite observatories, improved understanding of phenomena, expanded global and regional databases, geographic information systems, higher capacity for computer modeling, numerical simulations, etc provide a scientific-technical framework for developing strategies. Hazard prevention and mitigation programs will result in high costs globally, however major costs and challenges concentrate on the less developed economies already affected by poverty, famines, health problems, social inequalities, poor infrastructure, low life expectancy, high population growth

  9. STS-95 Payload Specialist Glenn and his wife pose before their return flight to JSC

    Science.gov (United States)

    1998-01-01

    At the Skid Strip at Cape Canaveral Air Station, STS-95 Payload Specialist John H. Glenn Jr., a senator from Ohio and one of the original seven Project Mercury astronauts, poses with his wife Annie before their return flight to the Johnson Space Center in Houston, Texas. The STS-95 mission ended with landing at Kennedy Space Center's Shuttle Landing Facility at 12:04 p.m. EST on Nov. 7. The STS-95 crew also includes Mission Commander Curtis L. Brown Jr.; Pilot Steven W. Lindsey; Mission Specialist Scott E. Parazynski; Mission Specialist Stephen K. Robinson; Mission Specialist Pedro Duque, with the European Space Agency (ESA); and Payload Specialist Chiaki Mukai, with the National Space Development Agency of Japan (NASDA). The mission included research payloads such as the Spartan-201 solar-observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as a SPACEHAB single module with experiments on space flight and the aging process.

  10. Absolute stability results for well-posed infinite-dimensional systems with applications to low-gain integral control

    NARCIS (Netherlands)

    Logemann, H; Curtain, RF

    2000-01-01

    We derive absolute stability results for well-posed infinite-dimensional systems which, in a sense, extend the well-known circle criterion to the case that the underlying linear system is the series interconnection of an exponentially stable well-posed infinite-dimensional system and an integrator

  11. Precise 3D Lug Pose Detection Sensor for Automatic Robot Welding Using a Structured-Light Vision System

    Directory of Open Access Journals (Sweden)

    Il Jae Lee

    2009-09-01

    Full Text Available In this study, we propose a precise 3D lug pose detection sensor for automatic robot welding of a lug to a huge steel plate used in shipbuilding, where the lug is a handle to carry the huge steel plate. The proposed sensor consists of a camera and four laser line diodes, and its design parameters are determined by analyzing its detectable range and resolution. For the lug pose acquisition, four laser lines are projected on both lug and plate, and the projected lines are detected by the camera. For robust detection of the projected lines against the illumination change, the vertical threshold, thinning, Hough transform and separated Hough transform algorithms are successively applied to the camera image. The lug pose acquisition is carried out by two stages: the top view alignment and the side view alignment. The top view alignment is to detect the coarse lug pose relatively far from the lug, and the side view alignment is to detect the fine lug pose close to the lug. After the top view alignment, the robot is controlled to move close to the side of the lug for the side view alignment. By this way, the precise 3D lug pose can be obtained. Finally, experiments with the sensor prototype are carried out to verify the feasibility and effectiveness of the proposed sensor.

  12. Estimation of Faults in DC Electrical Power System

    Science.gov (United States)

    Gorinevsky, Dimitry; Boyd, Stephen; Poll, Scott

    2009-01-01

    This paper demonstrates a novel optimization-based approach to estimating fault states in a DC power system. Potential faults changing the circuit topology are included along with faulty measurements. Our approach can be considered as a relaxation of the mixed estimation problem. We develop a linear model of the circuit and pose a convex problem for estimating the faults and other hidden states. A sparse fault vector solution is computed by using 11 regularization. The solution is computed reliably and efficiently, and gives accurate diagnostics on the faults. We demonstrate a real-time implementation of the approach for an instrumented electrical power system testbed, the ADAPT testbed at NASA ARC. The estimates are computed in milliseconds on a PC. The approach performs well despite unmodeled transients and other modeling uncertainties present in the system.

  13. Swiss Energy Perspectives 2035 - Management summary

    International Nuclear Information System (INIS)

    2007-01-01

    This management summary issued by the Swiss Federal Office of Energy (SFOE) summarises the Swiss Energy Perspectives 2035 - a five-part synthesis report published in 2007. The report presents no prognoses but provides an 'if-then' overview of a set of four scenarios that examined ways in which Swiss energy demands could be met by the year 2035. National and international boundary conditions taken into account are reviewed and the four scenarios are introduced and briefly described. These include the reference scenario 'Business as Usual', 'Increased Co-operation' between politics and business, 'New Priorities' with goals set to reduce energy consumption and CO 2 emissions and 'On the Way to a 2000-Watt Society'. Risks posed and chances provided are discussed, as are the options for taking action

  14. Metals and metalloids in PM10 in Nandan County, Guangxi, China, and the health risks posed.

    Science.gov (United States)

    Guo, Guanghui; Song, Bo; Xia, Deshang; Yang, Zijie; Wang, Fopeng

    2018-03-16

    Intense mining, smelting, and tailing activities of polymetallic ore deposits have affected the environment in Nandan County, Guangxi, China. Samples of particulates with aerodynamic diameters low or equal 10 μm (PM 10 ) were collected in Nandan County to investigate the concentrations of and health risks posed by 17 metals and metalloids in the PM 10 . The metal and metalloid concentrations were lower than those found in other industrial cities. The mean Cr concentration was 7.48 ng/m 3 . Significant higher metal and metalloid concentrations were found in PM 10 from mining areas (Dachang and Chehe) than from the control area (Liuzhai) (p metalloids in PM 10 at all the sites were low, but the non-carcinogenic risks posed to children by all the metals and metalloids together exceeded the safe level (i.e., risk value > 1). The carcinogenic risks posed by Cd, Ni, and Pb were negligible at all sites, while As, Co, and Cr posed potential carcinogenic risks to the residents.

  15. Pain from the life cycle perspective: Evaluation and Measurement through psychophysical methods of category estimation and magnitude estimation.

    Science.gov (United States)

    Sousa, Fátima Aparecida Emm Faleiros; Silva, Talita de Cássia Raminelli da; Siqueira, Hilze Benigno de Oliveira Moura; Saltareli, Simone; Gomez, Rodrigo Ramon Falconi; Hortense, Priscilla

    2016-08-18

    to describe acute and chronic pain from the perspective of the life cycle. participants: 861 people in pain. The Multidimensional Pain Evaluation Scale (MPES) was used. in the category estimation method the highest descriptors of chronic pain for children/ adolescents were "Annoying" and for adults "Uncomfortable". The highest descriptors of acute pain for children/adolescents was "Complicated"; and for adults was "Unbearable". In magnitude estimation method, the highest descriptors of chronic pain was "Desperate" and for descriptors of acute pain was "Terrible". the MPES is a reliable scale it can be applied during different stages of development. descrever a dor aguda e a crônica na perspectiva do ciclo vital. Métodos: participaram 861 pessoas com dor. Foi utilizada a Escala Multidimensional de Avaliação da Dor (EMADOR). Resultados: no método da estimação de categoria o descritor da dor crônica de maior atribuição para crianças e adolescentes foi "Chata" e para adultos foi "Desconfortável". Os descritores de maior atribuição para dor aguda em crianças e adolescentes foram "Complicada" e em adultos "Insuportável". No método de estimação de magnitude, o descritor de maior atribuição na dor crônica foi "Atormentadora" e na dor aguda foi "Terrível". a EMADOR é uma escala confiável e pode ser utilizada nas diferentes etapas do desenvolvimento humano. la descripción del dolor agudo y crónico desde las perspectiva del ciclo de vida. participaron 861 personas con dolor. Se utilizó la Escala Multidimensional de Evaluación del Dolor (EMEDOR). en el método de estimación de categoría el descriptor de dolor crónico más alto para niños y adolescentes fue de Molesto y para adultos fue Incómodo. Los descriptores mayores de dolor agudo para niños y adolescentes fueron Complejo y para adultos Insoportable. En el método de estimación de magnitud, el mayor descriptor de dolor crónico fueron Atormentador y el mayor de dolor agudo fue Terrible

  16. A circular feature-based pose measurement method for metal part grasping

    International Nuclear Information System (INIS)

    Wu, Chenrui; He, Zaixing; Zhang, Shuyou; Zhao, Xinyue

    2017-01-01

    The grasping of circular metal parts such as bearings and flanges is a common task in industry. Limited by low texture and repeated features, the point-feature-based method is not applicable in pose measurement of these parts. In this paper, we propose a novel pose measurement method for grasping circular metal parts. This method is based on cone degradation and involves a monocular camera. To achieve higher measurement accuracy, a position-based visual servoing method is presented to continuously control an eye-in-hand, six-degrees-of-freedom robot arm to grasp the part. The uncertainty of the part’s coordinate frame during the control process is solved by defining a fixed virtual coordinate frame. Experimental results are provided to illustrate the effectiveness of the proposed method and the factors that affect measurement accuracy are analyzed. (paper)

  17. Multimedia approach to estimating target cleanup levels for soils at hazardous waste sites

    International Nuclear Information System (INIS)

    Hwang, S.T.

    1990-04-01

    Contaminated soils at hazardous and nuclear waste sites pose a potential threat to human health via transport through environmental media and subsequent human intake. To minimize health risks, it is necessary to identify those risks and ensure that appropriate actions are taken to protect public health. The regulatory process may typically include identification of target cleanup levels and evaluation of the effectiveness of remedial alternatives and the corresponding reduction in risks at a site. The US Environmental Protection Agency (EPA) recommends that exposure assessments be combined with toxicity information to quantify the health risk posed by a specific site. This recommendation then forms the basis for establishing target cleanup levels. An exposure assessment must first identify the chemical concentration in a specific medium (soil, water, air, or food), estimate the exposure potential based on human intake from that media, and then combined with health criteria to estimate the upperbound health risks for noncarcinogens and carcinogens. Estimation of target cleanup levels involves the use of these same principles but can occur in reverse order. The procedure starts from establishing a permissible health effect level and ends with an estimated target cleanup level through an exposure assessment process. 17 refs

  18. Real-time gaze estimation via pupil center tracking

    Directory of Open Access Journals (Sweden)

    Cazzato Dario

    2018-02-01

    Full Text Available Automatic gaze estimation not based on commercial and expensive eye tracking hardware solutions can enable several applications in the fields of human computer interaction (HCI and human behavior analysis. It is therefore not surprising that several related techniques and methods have been investigated in recent years. However, very few camera-based systems proposed in the literature are both real-time and robust. In this work, we propose a real-time user-calibration-free gaze estimation system that does not need person-dependent calibration, can deal with illumination changes and head pose variations, and can work with a wide range of distances from the camera. Our solution is based on a 3-D appearance-based method that processes the images from a built-in laptop camera. Real-time performance is obtained by combining head pose information with geometrical eye features to train a machine learning algorithm. Our method has been validated on a data set of images of users in natural environments, and shows promising results. The possibility of a real-time implementation, combined with the good quality of gaze tracking, make this system suitable for various HCI applications.

  19. The STS-95 crew poses with a Mercury capsule model before returning to JSC

    Science.gov (United States)

    1998-01-01

    Before returning to the Johnson Space Center in Houston, Texas, members of the STS-95 crew pose with a model of a Mercury capsule following a media briefing at the Kennedy Space Center Press Site Auditorium . From left to right are Payload Specialist Chiaki Mukai, with the National Space Development Agency of Japan (NASDA); Pilot Steven W. Lindsey; Mission Commander Curtis L. Brown Jr.; Friendship 7; Payload Specialist John H. Glenn Jr., a senator from Ohio and one of the original seven Project Mercury astronauts; Mission Specialist Scott E. Parazynski; and Mission Specialist Pedro Duque, with the European Space Agency (ESA). Also on the crew is Mission Specialist and Payload Commander Stephen K. Robinson (not shown). The STS-95 mission ended with landing at Kennedy Space Center's Shuttle Landing Facility at 12:04 p.m. EST on Nov. 7. The mission included research payloads such as the Spartan-201 solar-observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as a SPACEHAB single module with experiments on space flight and the aging process.

  20. Single molecule SERS: Perspectives of analytical applications

    Czech Academy of Sciences Publication Activity Database

    Vlčková, B.; Pavel, I.; Sládková, M.; Šišková, K.; Šlouf, Miroslav

    834-836, - (2007), s. 42-47 ISSN 0022-2860. [European Congress on Molecular Spectroscopy /28./. Istanbul, 03.09.2006-08.09.2006] R&D Projects: GA ČR GA203/04/0688 Institutional research plan: CEZ:AV0Z40500505 Keywords : surface-enhanced Raman scattering (SERS) * surface-enhanced resonance Raman (SERRS) * single molecule SERS Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.486, year: 2007

  1. Estimated risk from exposure to radon decay products in US homes

    International Nuclear Information System (INIS)

    Nero, A.V. Jr.

    1986-05-01

    Recent analyses now permit direct estimation of the risks of lung cancer from radon decay products in US homes. Analysis of data from indoor monitoring in single-family homes yields a tentative frequency distribution of annual-average 222 Rn concentrations averaging 55 Bq m -3 and having 2% of homes exceeding 300 Bq m -3 . Application of the results of occupational epidemiological studies, either directly or using recent advances in lung dosimetry, to indoor exposures suggests that the average indoor concentration entails a lifetime risk of lung cancer of 0.3% or about 10% of the total risk of lung cancer. The risk to individuals occupying the homes with 300 Bq m -3 or more for their lifetimes is estimated to exceed 2%, with risks from the homes with thousands of Bq m -3 correspondingly higher, even exceeding the total risk of premature death due to cigarette smoking. The potential for such average and high-level risks in ordinary homes forces development of a new perspective on environmental exposures

  2. Penalized Maximum Likelihood Estimation for univariate normal mixture distributions

    International Nuclear Information System (INIS)

    Ridolfi, A.; Idier, J.

    2001-01-01

    Due to singularities of the likelihood function, the maximum likelihood approach for the estimation of the parameters of normal mixture models is an acknowledged ill posed optimization problem. Ill posedness is solved by penalizing the likelihood function. In the Bayesian framework, it amounts to incorporating an inverted gamma prior in the likelihood function. A penalized version of the EM algorithm is derived, which is still explicit and which intrinsically assures that the estimates are not singular. Numerical evidence of the latter property is put forward with a test

  3. Penalized linear regression for discrete ill-posed problems: A hybrid least-squares and mean-squared error approach

    KAUST Repository

    Suliman, Mohamed Abdalla Elhag; Ballal, Tarig; Kammoun, Abla; Al-Naffouri, Tareq Y.

    2016-01-01

    This paper proposes a new approach to find the regularization parameter for linear least-squares discrete ill-posed problems. In the proposed approach, an artificial perturbation matrix with a bounded norm is forced into the discrete ill-posed model

  4. Effects of ionizing radiation on cell-matrix interactions at the single molecule level

    Energy Technology Data Exchange (ETDEWEB)

    Lauer, Florian

    2015-04-20

    Single molecule microscopy is a technology that allows for accurate assessment of the location and motion of single fluorescent molecules, even in the context of observations on living biological samples. In the present thesis, a flexible analysis tool for single molecule data as obtained in biological experiments was established. The development of a tool to faithfully detect and localize diffraction-limited images of individual fluorescent probes was necessary since data acquired under cell cultivation conditions that account for a three-dimensional microenvironment as experienced physiologically by cells in native tissue poses a challenge not faced ordinarily. After design, implementation, quantitative tests using simulations for comparisons and verification, and evaluation of the different steps of the analysis procedure including local background estimation, local noise estimation, de-noising approaches, detection, localization, and post-processing, analysis capabilities were utilized to evaluate the impact of x-ray irradiation on the plasma membrane architecture of U2OS human osteosarcoma cells as assessed by tracking individual fluorescent lipid-mimetic dye molecules diffusing in the outer membrane leaflet. It was shown that lateral diffusion in the plasma membrane is well described as two-phase anomalous subdiffusion and presence of 3D extracellular matrix leads to lower anomalous exponents of the fast fraction in comparison to monolayer cell culture. Interestingly, even high single-dose (25 Gy) treatments known to induce membrane-mediated apoptosis in tumor microvessel endothelium via membrane viscosity enhancing ceramide generation were not observed to alter membrane architecture in U2OS cells which can be related to amplifying, feedback-driven redox-signaling in the endothelium absent in U2OS. In summary, the sensitive and accurate framework developed in this thesis to assess minute changes of plasma membrane located dynamic processes did not uncover a

  5. Effects of ionizing radiation on cell-matrix interactions at the single molecule level

    International Nuclear Information System (INIS)

    Lauer, Florian

    2015-01-01

    Single molecule microscopy is a technology that allows for accurate assessment of the location and motion of single fluorescent molecules, even in the context of observations on living biological samples. In the present thesis, a flexible analysis tool for single molecule data as obtained in biological experiments was established. The development of a tool to faithfully detect and localize diffraction-limited images of individual fluorescent probes was necessary since data acquired under cell cultivation conditions that account for a three-dimensional microenvironment as experienced physiologically by cells in native tissue poses a challenge not faced ordinarily. After design, implementation, quantitative tests using simulations for comparisons and verification, and evaluation of the different steps of the analysis procedure including local background estimation, local noise estimation, de-noising approaches, detection, localization, and post-processing, analysis capabilities were utilized to evaluate the impact of x-ray irradiation on the plasma membrane architecture of U2OS human osteosarcoma cells as assessed by tracking individual fluorescent lipid-mimetic dye molecules diffusing in the outer membrane leaflet. It was shown that lateral diffusion in the plasma membrane is well described as two-phase anomalous subdiffusion and presence of 3D extracellular matrix leads to lower anomalous exponents of the fast fraction in comparison to monolayer cell culture. Interestingly, even high single-dose (25 Gy) treatments known to induce membrane-mediated apoptosis in tumor microvessel endothelium via membrane viscosity enhancing ceramide generation were not observed to alter membrane architecture in U2OS cells which can be related to amplifying, feedback-driven redox-signaling in the endothelium absent in U2OS. In summary, the sensitive and accurate framework developed in this thesis to assess minute changes of plasma membrane located dynamic processes did not uncover a

  6. The role of nanotechnology in single-cell detection: a review.

    Science.gov (United States)

    Wang, Changling; Zhang, Yuxiang; Xia, Mingdian; Zhu, Xingxi; Qi, Shitao; Shen, Huaqiang; Liu, Tiebing; Tang, Liming

    2014-10-01

    Biological processes in single cells, such as signal transduction, DNA duplication, and protein synthesis and trafficking, occur in subcellular compartments at nanoscale level. Achieving high spatial-temporal resolution, high sensitivity, and high specificity in single-cell detection poses a great challenge. Nanotechnology, which has been widely applied in the fields of medicine, electronics, biomaterials, and energy production, has the potential to provide solutions for single-cell detection. Here we present a review of the use of nanotechnology in single-cell detection over the past two decades. First, we review the main areas of scientific interest, including morphology, ion concentration, DNA, RNA, protein, intracellular temperature, elements, and mechanical properties. Second, four categories of application of nanotechnology to single-cell detection are described: nanomanipulation, nanodevices, nanomaterials as labels, and nano Secondary ion mass spectrometry. Finally, the prospects and future trends in single-cell detection and analysis are discussed.

  7. Robotic single port cholecystectomy: current data and future perspectives.

    Science.gov (United States)

    Angelou, Anastasios; Skarmoutsos, Athanasios; Margonis, Georgios A; Moris, Demetrios; Tsigris, Christos; Pikoulis, Emmanouil

    2017-04-01

    Minimally invasive techniques are used more and more frequently. Since conventional laparoscopic approach has been the gold standard, surgeons in their effort to further reduce the invasiveness of conventional laparoscopic cholecystectomy have adopted Single Incision approach. The widespread adoption of robotics has led to the inevitable hybridization of robotic technology with laparoendoscopic single-site surgery (LESS). As a result, employment of the da Vinci surgical system may allow greater surgical maneuverability, improving ergonomics. A review of the English literature was conducted to evaluate all robotic single port cholecystectomy performed till today. Demographic data, operative parameters, postoperative outcomes and materials used for the operation were collected and assessed. A total of 12 studies, including 501 patients were analyzed. Demographics and clinical characteristics of the patients was heterogeneous, but in most studies a mean BMI port cholecystectomy is a safe and feasible alternative to conventional multiport laparoscopic or manual robotic approach. However, current data do not suggest a superiority of robotic SILC over other established methods.

  8. Solution of linear ill-posed problems using overcomplete dictionaries

    OpenAIRE

    Pensky, Marianna

    2016-01-01

    In the present paper we consider application of overcomplete dictionaries to solution of general ill-posed linear inverse problems. Construction of an adaptive optimal solution for such problems usually relies either on a singular value decomposition or representation of the solution via an orthonormal basis. The shortcoming of both approaches lies in the fact that, in many situations, neither the eigenbasis of the linear operator nor a standard orthonormal basis constitutes an appropriate co...

  9. Theoretical implications for the estimation of dinitrogen fixation by large perennial plant species using isotope dilution

    Science.gov (United States)

    Dwight D. Baker; Maurice Fried; John A. Parrotta

    1995-01-01

    Estimation of symbiotic N2 fixation associated with large perennial plant species, especially trees, poses special problems because the process must be followed over a potentially long period of time to integrate the total amount of fixation. Estimations using isotope dilution methodology have begun to be used for trees in field studies. Because...

  10. Robust subspace estimation using low-rank optimization theory and applications

    CERN Document Server

    Oreifej, Omar

    2014-01-01

    Various fundamental applications in computer vision and machine learning require finding the basis of a certain subspace. Examples of such applications include face detection, motion estimation, and activity recognition. An increasing interest has been recently placed on this area as a result of significant advances in the mathematics of matrix rank optimization. Interestingly, robust subspace estimation can be posed as a low-rank optimization problem, which can be solved efficiently using techniques such as the method of Augmented Lagrange Multiplier. In this book,?the authors?discuss fundame

  11. A Geology-Based Estimate of Connate Water Salinity Distribution

    Science.gov (United States)

    2014-09-01

    poses serious environmental concerns if connate water is mobilized into shallow aquifers or surface water systems. Estimating the distribution of...groundwater flow and salinity transport near the Herbert Hoover Dike (HHD) surrounding Lake Okeechobee in Florida . The simulations were conducted using the...on the geologic configuration at equilibrium, and the horizontal salinity distribution is strongly linked to aquifer connectivity because

  12. Lessons in Outbreak a Consumer perspective

    NARCIS (Netherlands)

    Fischer, A.R.H.

    2008-01-01

    Lessons in Outbreak a Consumer perspective. Arnout Fischer Consumer risk perceptions is not necessarily the same as an economic weighing of risks and benefits. Consumers tend to be risk averse, tend to estimate catastrophic, unnatural or involuntary risks as larger, while personal lifestyle risks

  13. Health risks posed to infants in rural China by exposure to short- and medium-chain chlorinated paraffins in breast milk.

    Science.gov (United States)

    Xia, Dan; Gao, Li-Rong; Zheng, Ming-Hui; Li, Jing-Guang; Zhang, Lei; Wu, Yong-Ning; Qiao, Lin; Tian, Qi-Chang; Huang, Hui-Ting; Liu, Wen-Bin; Su, Gui-Jin; Liu, Guo-Rui

    2017-06-01

    Chlorinated paraffins (CPs) are complex mixtures of synthetic chemicals found widely in environmental matrices. Short-chain CPs (SCCPs) are candidate persistent organic pollutants under the Stockholm Convention. There should be great concern about human exposure to SCCPs. Data on CP concentrations in human breast milk is scarce. This is the first study in which background SCCP and medium-chain CP (MCCP) body burdens in the general rural population of China have been estimated and health risks posed to nursing infants by CPs in breast milk assessed. The concentrations of 48 SCCP and MCCP formula congeners were determined in 24 pooled human milk samples produced from 1412 individual samples from eight provinces in 2007 and 16 provinces in 2011. The samples were analyzed by comprehensive two-dimensional gas chromatography electron capture negative ionization high-resolution time-of-flight mass spectrometry. The median SCCP and MCCP concentrations were 303 and 35.7ngg -1 lipid weight, respectively, for the 2007 samples and 360 and 45.4ngg -1 lipid weight, respectively, for the 2011 samples. The C 10 and C 14 homologs were the dominant CP carbon-chain-length groups, contributing 51% and 82% of the total SCCP and MCCP concentrations, respectively. There are probably multiple CP sources to the general Chinese population and numerous exposure pathways. The median estimated daily SCCP and MCCP intakes for nursing infants were 1310 and 152ngkg -1 d -1 , respectively, in 2007 and 1520 and 212ngkg -1 d -1 , respectively, in 2011. SCCPs do not currently pose significant risks to infants in China. However, it is necessary to continuously monitor CP concentrations and health risks because CP concentrations in Chinese human breast milk are increasing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A Single Image Deblurring Algorithm for Nonuniform Motion Blur Using Uniform Defocus Map Estimation

    Directory of Open Access Journals (Sweden)

    Chia-Feng Chang

    2017-01-01

    Full Text Available One of the most common artifacts in digital photography is motion blur. When capturing an image under dim light by using a handheld camera, the tendency of the photographer’s hand to shake causes the image to blur. In response to this problem, image deblurring has become an active topic in computational photography and image processing in recent years. From the view of signal processing, image deblurring can be reduced to a deconvolution problem if the kernel function of the motion blur is assumed to be shift invariant. However, the kernel function is not always shift invariant in real cases; for example, in-plane rotation of a camera or a moving object can blur different parts of an image according to different kernel functions. An image that is degraded by multiple blur kernels is called a nonuniform blur image. In this paper, we propose a novel single image deblurring algorithm for nonuniform motion blur images that is blurred by moving object. First, a proposed uniform defocus map method is presented for measurement of the amounts and directions of motion blur. These blurred regions are then used to estimate point spread functions simultaneously. Finally, a fast deconvolution algorithm is used to restore the nonuniform blur image. We expect that the proposed method can achieve satisfactory deblurring of a single nonuniform blur image.

  15. Pose estimation for mobile devices and augmented reality

    NARCIS (Netherlands)

    Caarls, J.

    2009-01-01

    In this thesis we introduce the reader to the field of Augmented Reality (AR) and describe aspects of an AR system. We show the current uses in treatment of phobias, games, sports and industry. We present the challenges for Optical See-Through Augmented Reality in which the real world is perceived

  16. Correcting estimators of theta and Tajima's D for ascertainment biases caused by the single-nucleotide polymorphism discovery process

    DEFF Research Database (Denmark)

    Ramírez-Soriano, Anna; Nielsen, Rasmus

    2009-01-01

    Most single-nucleotide polymorphism (SNP) data suffer from an ascertainment bias caused by the process of SNP discovery followed by SNP genotyping. The final genotyped data are biased toward an excess of common alleles compared to directly sequenced data, making standard genetic methods of analysis...... the variances and covariances of these estimators and provide a corrected version of Tajima's D statistic. We reanalyze a human genomewide SNP data set and find substantial differences in the results with or without ascertainment bias correction....

  17. Non-fatal disease burden for subtypes of depressive disorder: population-based epidemiological study.

    Science.gov (United States)

    Biesheuvel-Leliefeld, Karolien E M; Kok, Gemma D; Bockting, Claudi L H; de Graaf, Ron; Ten Have, Margreet; van der Horst, Henriette E; van Schaik, Anneke; van Marwijk, Harm W J; Smit, Filip

    2016-05-12

    Major depression is the leading cause of non-fatal disease burden. Because major depression is not a homogeneous condition, this study estimated the non-fatal disease burden for mild, moderate and severe depression in both single episode and recurrent depression. All estimates were assessed from an individual and a population perspective and presented as unadjusted, raw estimates and as estimates adjusted for comorbidity. We used data from the first wave of the second Netherlands-Mental-Health-Survey-and-Incidence-Study (NEMESIS-2, n = 6646; single episode Diagnostic and Statistical Manual (DSM)-IV depression, n = 115; recurrent depression, n = 246). Disease burden from an individual perspective was assessed as 'disability weight * time spent in depression' for each person in the dataset. From a population perspective it was assessed as 'disability weight * time spent in depression *number of people affected'. The presence of mental disorders was assessed with the Composite International Diagnostic Interview (CIDI) 3.0. Single depressive episodes emerged as a key driver of disease burden from an individual perspective. From a population perspective, recurrent depressions emerged as a key driver. These findings remained unaltered after adjusting for comorbidity. The burden of disease differs between the subtype of depression and depends much on the choice of perspective. The distinction between an individual and a population perspective may help to avoid misunderstandings between policy makers and clinicians.

  18. Effects of the Problem-Posing Approach on Students' Problem Solving Skills and Metacognitive Awareness in Science Education

    Science.gov (United States)

    Akben, Nimet

    2018-05-01

    The interrelationship between mathematics and science education has frequently been emphasized, and common goals and approaches have often been adopted between disciplines. Improving students' problem-solving skills in mathematics and science education has always been given special attention; however, the problem-posing approach which plays a key role in mathematics education has not been commonly utilized in science education. As a result, the purpose of this study was to better determine the effects of the problem-posing approach on students' problem-solving skills and metacognitive awareness in science education. This was a quasi-experimental based study conducted with 61 chemistry and 40 physics students; a problem-solving inventory and a metacognitive awareness inventory were administered to participants both as a pre-test and a post-test. During the 2017-2018 academic year, problem-solving activities based on the problem-posing approach were performed with the participating students during their senior year in various university chemistry and physics departments throughout the Republic of Turkey. The study results suggested that structured, semi-structured, and free problem-posing activities improve students' problem-solving skills and metacognitive awareness. These findings indicated not only the usefulness of integrating problem-posing activities into science education programs but also the need for further research into this question.

  19. Foreign-funded M&A Poses No Threatto China’s Economic Security

    Institute of Scientific and Technical Information of China (English)

    王志乐

    2007-01-01

    Foreign funded M■A(Mergers ■ Acquisitions) activity is becoming increasingly common in China.In this article Wang Zhile assesses the effects and risks associated with M■A,finding that foreign funded M■A activity is immensely beneficial to China and poses no threat to economic security.

  20. Multi-annual forward estimate - gas 2017

    International Nuclear Information System (INIS)

    2017-01-01

    GRDF, GRTgaz, SPEGNN and TIGF gas transport and distribution operators have the responsibility to publish a reference document about the multi-annual forward estimate of gas consumption evolution and renewable gas production. This document is the second joint forecast report published by the 4 French gas operators. It presents, first, the situation, hypotheses, analysis and perspectives of the 4 main sectoral gas markets (residential, tertiary, industrial, mobility), then, the centralized power generation and cogeneration, next, the production of renewable gas (different sectors, hypotheses, analysis and perspectives), and finally, a multi-sectorial vision according to 3 different scenarios