Space moving target detection using time domain feature

Science.gov (United States)

Wang, Min; Chen, Jin-yong; Gao, Feng; Zhao, Jin-yu

2018-01-01

The traditional space target detection methods mainly use the spatial characteristics of the star map to detect the targets, which can not make full use of the time domain information. This paper presents a new space moving target detection method based on time domain features. We firstly construct the time spectral data of star map, then analyze the time domain features of the main objects (target, stars and the background) in star maps, finally detect the moving targets using single pulse feature of the time domain signal. The real star map target detection experimental results show that the proposed method can effectively detect the trajectory of moving targets in the star map sequence, and the detection probability achieves 99% when the false alarm rate is about 8×10-5, which outperforms those of compared algorithms.

Camouflage, detection and identification of moving targets.

Science.gov (United States)

Hall, Joanna R; Cuthill, Innes C; Baddeley, Roland; Shohet, Adam J; Scott-Samuel, Nicholas E

2013-05-07

Nearly all research on camouflage has investigated its effectiveness for concealing stationary objects. However, animals have to move, and patterns that only work when the subject is static will heavily constrain behaviour. We investigated the effects of different camouflages on the three stages of predation-detection, identification and capture-in a computer-based task with humans. An initial experiment tested seven camouflage strategies on static stimuli. In line with previous literature, background-matching and disruptive patterns were found to be most successful. Experiment 2 showed that if stimuli move, an isolated moving object on a stationary background cannot avoid detection or capture regardless of the type of camouflage. Experiment 3 used an identification task and showed that while camouflage is unable to slow detection or capture, camouflaged targets are harder to identify than uncamouflaged targets when similar background objects are present. The specific details of the camouflage patterns have little impact on this effect. If one has to move, camouflage cannot impede detection; but if one is surrounded by similar targets (e.g. other animals in a herd, or moving background distractors), then camouflage can slow identification. Despite previous assumptions, motion does not entirely 'break' camouflage.

A Review of Ground Target Detection and Classification Techniques in Forward Scattering Radars

Directory of Open Access Journals (Sweden)

M. E. A. Kanona

2018-06-01

Full Text Available This paper presents a review of target detection and classification in forward scattering radar (FSR which is a special state of bistatic radars, designed to detect and track moving targets in the narrow region along the transmitter-receiver base line. FSR has advantages and incredible features over other types of radar configurations. All previous studies proved that FSR can be used as an alternative system for ground target detection and classification. The radar and FSR fundamentals were addressed and classification algorithms and techniques were debated. On the other hand, the current and future applications and the limitations of FSR were discussed.

Pilots' Attention Distributions Between Chasing a Moving Target and a Stationary Target.

Science.gov (United States)

Li, Wen-Chin; Yu, Chung-San; Braithwaite, Graham; Greaves, Matthew

2016-12-01

Attention plays a central role in cognitive processing; ineffective attention may induce accidents in flight operations. The objective of the current research was to examine military pilots' attention distributions between chasing a moving target and a stationary target. In the current research, 37 mission-ready F-16 pilots participated. Subjects' eye movements were collected by a portable head-mounted eye-tracker during tactical training in a flight simulator. The scenarios of chasing a moving target (air-to-air) and a stationary target (air-to-surface) consist of three operational phases: searching, aiming, and lock-on to the targets. The findings demonstrated significant differences in pilots' percentage of fixation during the searching phase between air-to-air (M = 37.57, SD = 5.72) and air-to-surface (M = 33.54, SD = 4.68). Fixation duration can indicate pilots' sustained attention to the trajectory of a dynamic target during air combat maneuvers. Aiming at the stationary target resulted in larger pupil size (M = 27,105, SD = 6565), reflecting higher cognitive loading than aiming at the dynamic target (M = 23,864, SD = 8762). Pilots' visual behavior is not only closely related to attention distribution, but also significantly associated with task characteristics. Military pilots demonstrated various visual scan patterns for searching and aiming at different types of targets based on the research settings of a flight simulator. The findings will facilitate system designers' understanding of military pilots' cognitive processes during tactical operations. They will assist human-centered interface design to improve pilots' situational awareness. The application of an eye-tracking device integrated with a flight simulator is a feasible and cost-effective intervention to improve the efficiency and safety of tactical training.Li W-C, Yu C-S, Braithwaite G, Greaves M. Pilots' attention distributions between chasing a moving target and a stationary target. Aerosp Med

Schema generation in recurrent neural nets for intercepting a moving target.

Science.gov (United States)

Fleischer, Andreas G

2010-06-01

The grasping of a moving object requires the development of a motor strategy to anticipate the trajectory of the target and to compute an optimal course of interception. During the performance of perception-action cycles, a preprogrammed prototypical movement trajectory, a motor schema, may highly reduce the control load. Subjects were asked to hit a target that was moving along a circular path by means of a cursor. Randomized initial target positions and velocities were detected in the periphery of the eyes, resulting in a saccade toward the target. Even when the target disappeared, the eyes followed the target's anticipated course. The Gestalt of the trajectories was dependent on target velocity. The prediction capability of the motor schema was investigated by varying the visibility range of cursor and target. Motor schemata were determined to be of limited precision, and therefore visual feedback was continuously required to intercept the moving target. To intercept a target, the motor schema caused the hand to aim ahead and to adapt to the target trajectory. The control of cursor velocity determined the point of interception. From a modeling point of view, a neural network was developed that allowed the implementation of a motor schema interacting with feedback control in an iterative manner. The neural net of the Wilson type consists of an excitation-diffusion layer allowing the generation of a moving bubble. This activation bubble runs down an eye-centered motor schema and causes a planar arm model to move toward the target. A bubble provides local integration and straightening of the trajectory during repetitive moves. The schema adapts to task demands by learning and serves as forward controller. On the basis of these model considerations the principal problem of embedding motor schemata in generalized control strategies is discussed.

Cooperative Robots to Observe Moving Targets: Review.

Science.gov (United States)

Khan, Asif; Rinner, Bernhard; Cavallaro, Andrea

2018-01-01

The deployment of multiple robots for achieving a common goal helps to improve the performance, efficiency, and/or robustness in a variety of tasks. In particular, the observation of moving targets is an important multirobot application that still exhibits numerous open challenges, including the effective coordination of the robots. This paper reviews control techniques for cooperative mobile robots monitoring multiple targets. The simultaneous movement of robots and targets makes this problem particularly interesting, and our review systematically addresses this cooperative multirobot problem for the first time. We classify and critically discuss the control techniques: cooperative multirobot observation of multiple moving targets, cooperative search, acquisition, and track, cooperative tracking, and multirobot pursuit evasion. We also identify the five major elements that characterize this problem, namely, the coordination method, the environment, the target, the robot and its sensor(s). These elements are used to systematically analyze the control techniques. The majority of the studied work is based on simulation and laboratory studies, which may not accurately reflect real-world operational conditions. Importantly, while our systematic analysis is focused on multitarget observation, our proposed classification is useful also for related multirobot applications.

Moving target detection based on temporal-spatial information fusion for infrared image sequences

Science.gov (United States)

Toing, Wu-qin; Xiong, Jin-yu; Zeng, An-jun; Wu, Xiao-ping; Xu, Hao-peng

2009-07-01

Moving target detection and localization is one of the most fundamental tasks in visual surveillance. In this paper, through analyzing the advantages and disadvantages of the traditional approaches about moving target detection, a novel approach based on temporal-spatial information fusion is proposed for moving target detection. The proposed method combines the spatial feature in single frame and the temporal properties within multiple frames of an image sequence of moving target. First, the method uses the spatial image segmentation for target separation from background and uses the local temporal variance for extracting targets and wiping off the trail artifact. Second, the logical "and" operator is used to fuse the temporal and spatial information. In the end, to the fusion image sequence, the morphological filtering and blob analysis are used to acquire exact moving target. The algorithm not only requires minimal computation and memory but also quickly adapts to the change of background and environment. Comparing with other methods, such as the KDE, the Mixture of K Gaussians, etc., the simulation results show the proposed method has better validity and higher adaptive for moving target detection, especially in infrared image sequences with complex illumination change, noise change, and so on.

Forward Models for Following a Moving Target with the Puma 560 Robot Manipulator

Directory of Open Access Journals (Sweden)

Daniel Fernando Tello Gamarra

2015-12-01

Full Text Available This paper describes how a forward model could be applied in a manipulator robot to accomplish the task of following a moving target. The forward model has been implemented in the puma 560 robot manipulator in simulation after a babbling motor phase using ANFIS neural networks. The forward model delivers a rough estimation of the position in the operational space of a moving target. Using this information a Cartesian controller tracks the moving target. An implementation of the proposed architecture and the Piepmeir algorithm for the problem of following a moving target is also shown in the paper. The control architecture proposed in this paper was also tested with MLP and RBF neural networks. Results and simulations are shown to demonstrate the applicability of our proposed architecture for tracking a moving target.

Distributed Cooperative Search Control Method of Multiple UAVs for Moving Target

Directory of Open Access Journals (Sweden)

Chang-jian Ru

2015-01-01

Full Text Available To reduce the impact of uncertainties caused by unknown motion parameters on searching plan of moving targets and improve the efficiency of UAV’s searching, a novel distributed Multi-UAVs cooperative search control method for moving target is proposed in this paper. Based on detection results of onboard sensors, target probability map is updated using Bayesian theory. A Gaussian distribution of target transition probability density function is introduced to calculate prediction probability of moving target existence, and then target probability map can be further updated in real-time. A performance index function combining with target cost, environment cost, and cooperative cost is constructed, and the cooperative searching problem can be transformed into a central optimization problem. To improve computational efficiency, the distributed model predictive control method is presented, and thus the control command of each UAV can be obtained. The simulation results have verified that the proposed method can avoid the blindness of UAV searching better and improve overall efficiency of the team effectively.

Estimation of direction of arrival of a moving target using subspace based approaches

Science.gov (United States)

Ghosh, Ripul; Das, Utpal; Akula, Aparna; Kumar, Satish; Sardana, H. K.

2016-05-01

In this work, array processing techniques based on subspace decomposition of signal have been evaluated for estimation of direction of arrival of moving targets using acoustic signatures. Three subspace based approaches - Incoherent Wideband Multiple Signal Classification (IWM), Least Square-Estimation of Signal Parameters via Rotation Invariance Techniques (LS-ESPRIT) and Total Least Square- ESPIRIT (TLS-ESPRIT) are considered. Their performance is compared with conventional time delay estimation (TDE) approaches such as Generalized Cross Correlation (GCC) and Average Square Difference Function (ASDF). Performance evaluation has been conducted on experimentally generated data consisting of acoustic signatures of four different types of civilian vehicles moving in defined geometrical trajectories. Mean absolute error and standard deviation of the DOA estimates w.r.t. ground truth are used as performance evaluation metrics. Lower statistical values of mean error confirm the superiority of subspace based approaches over TDE based techniques. Amongst the compared methods, LS-ESPRIT indicated better performance.

Computing proton dose to irregularly moving targets

International Nuclear Information System (INIS)

Phillips, Justin; Gueorguiev, Gueorgui; Grassberger, Clemens; Dowdell, Stephen; Paganetti, Harald; Sharp, Gregory C; Shackleford, James A

2014-01-01

Purpose: While four-dimensional computed tomography (4DCT) and deformable registration can be used to assess the dose delivered to regularly moving targets, there are few methods available for irregularly moving targets. 4DCT captures an idealized waveform, but human respiration during treatment is characterized by gradual baseline shifts and other deviations from a periodic signal. This paper describes a method for computing the dose delivered to irregularly moving targets based on 1D or 3D waveforms captured at the time of delivery. Methods: The procedure uses CT or 4DCT images for dose calculation, and 1D or 3D respiratory waveforms of the target position at time of delivery. Dose volumes are converted from their Cartesian geometry into a beam-specific radiological depth space, parameterized in 2D by the beam aperture, and longitudinally by the radiological depth. In this new frame of reference, the proton doses are translated according to the motion found in the 1D or 3D trajectory. These translated dose volumes are weighted and summed, then transformed back into Cartesian space, yielding an estimate of the dose that includes the effect of the measured breathing motion. The method was validated using a synthetic lung phantom and a single representative patient CT. Simulated 4DCT was generated for the phantom with 2 cm peak-to-peak motion. Results: A passively-scattered proton treatment plan was generated using 6 mm and 5 mm smearing for the phantom and patient plans, respectively. The method was tested without motion, and with two simulated breathing signals: a 2 cm amplitude sinusoid, and a 2 cm amplitude sinusoid with 3 cm linear drift in the phantom. The tumor positions were equally weighted for the patient calculation. Motion-corrected dose was computed based on the mid-ventilation CT image in the phantom and the peak exhale position in the patient. Gamma evaluation was 97.8% without motion, 95.7% for 2 cm sinusoidal motion, 95.7% with 3 cm drift in

Research on moving target defense based on SDN

Science.gov (United States)

Chen, Mingyong; Wu, Weimin

2017-08-01

An address mutation strategy was proposed. This strategy provided an unpredictable change in address, replacing the real address of the packet forwarding process and path mutation, thus hiding the real address of the host and path. a mobile object defense technology based on Spatio-temporal Mutation on this basis is proposed, Using the software Defined Network centralized control architecture advantage combines sFlow traffic monitoring technology and Moving Target Defense. A mutated time period which can be changed in real time according to the network traffic is changed, and the destination address is changed while the controller abruptly changes the address while the data packet is transferred between the switches to construct a moving target, confusing the host within the network, thereby protecting the host and network.

Saccadic interception of a moving visual target after a spatiotemporal perturbation.

Science.gov (United States)

Fleuriet, Jérome; Goffart, Laurent

2012-01-11

Animals can make saccadic eye movements to intercept a moving object at the right place and time. Such interceptive saccades indicate that, despite variable sensorimotor delays, the brain is able to estimate the current spatiotemporal (hic et nunc) coordinates of a target at saccade end. The present work further tests the robustness of this estimate in the monkey when a change in eye position and a delay are experimentally added before the onset of the saccade and in the absence of visual feedback. These perturbations are induced by brief microstimulation in the deep superior colliculus (dSC). When the microstimulation moves the eyes in the direction opposite to the target motion, a correction saccade brings gaze back on the target path or very near. When it moves the eye in the same direction, the performance is more variable and depends on the stimulated sites. Saccades fall ahead of the target with an error that increases when the stimulation is applied more caudally in the dSC. The numerous cases of compensation indicate that the brain is able to maintain an accurate and robust estimate of the location of the moving target. The inaccuracies observed when stimulating the dSC that encodes the visual field traversed by the target indicate that dSC microstimulation can interfere with signals encoding the target motion path. The results are discussed within the framework of the dual-drive and the remapping hypotheses.

CHAOS: An SDN-Based Moving Target Defense System

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Yuan Shi

2017-01-01

Full Text Available Moving target defense (MTD has provided a dynamic and proactive network defense to reduce or move the attack surface that is available for exploitation. However, traditional network is difficult to realize dynamic and active security defense effectively and comprehensively. Software-defined networking (SDN points out a brand-new path for building dynamic and proactive defense system. In this paper, we propose CHAOS, an SDN-based MTD system. Utilizing the programmability and flexibility of SDN, CHAOS obfuscates the attack surface including host mutation obfuscation, ports obfuscation, and obfuscation based on decoy servers, thereby enhancing the unpredictability of the networking environment. We propose the Chaos Tower Obfuscation (CTO method, which uses the Chaos Tower Structure (CTS to depict the hierarchy of all the hosts in an intranet and define expected connection and unexpected connection. Moreover, we develop fast CTO algorithms to achieve a different degree of obfuscation for the hosts in each layer. We design and implement CHAOS as an application of SDN controller. Our approach makes it very easy to realize moving target defense in networks. Our experimental results show that a network protected by CHAOS is capable of decreasing the percentage of information disclosure effectively to guarantee the normal flow of traffic.

Moving finite element method for ICF target implosion

Science.gov (United States)

Furuta, J.; Kawata, S.; Niu, K.

1985-03-01

One dimensional hydrodynamic codes for the analysis of internal confinement fusion (ICF) target implosion which include various effects were developed, but most of them utilize the artificial viscosity (e.g., Von Neumann's viscosity) which cannot reveal accurately the shock waves. A gain of ICF target implosion is much due to the dissipation at the shock fronts, so it is necessary to express correctly the shock waves which are affected by the viscosity. The width of the shock waves is usually a few times as large as the length of mean free path, therefore the meshes for the shock waves must be set to about 10 to the 4th to 10 to the 5th power. It is a serious problem because of the computational memories or CPU time. In the moving finite element (MPE) method, both nodal amplitudes and nodal positions move continuously with time in such a way as to satisfy simultaneous ordinary differential equations (OPDs) which minimize partial differential equation (PDE) residuals.

Numerical simulation on range of high-energy electron moving in accelerator target

International Nuclear Information System (INIS)

Shao Wencheng; Sun Punan; Dai Wenjiang

2008-01-01

In order to determine the range of high-energy electron moving in accelerator target, the range of electron with the energy range of 1 to 100 MeV moving in common target material of accelerator was calculated by Monte-Carlo method. Comparison between the calculated result and the published data were performed. The results of Monte-Carlo calculation are in good agreement with the published data. Empirical formulas were obtained for the range of high-energy electron with the energy range of 1 to 100 MeV in common target material by curve fitting, offering a series of referenced data for the design of targets in electron accelerator. (authors)

Moving target tracking through distributed clustering in directional sensor networks.

Science.gov (United States)

Enayet, Asma; Razzaque, Md Abdur; Hassan, Mohammad Mehedi; Almogren, Ahmad; Alamri, Atif

2014-12-18

The problem of moving target tracking in directional sensor networks (DSNs) introduces new research challenges, including optimal selection of sensing and communication sectors of the directional sensor nodes, determination of the precise location of the target and an energy-efficient data collection mechanism. Existing solutions allow individual sensor nodes to detect the target's location through collaboration among neighboring nodes, where most of the sensors are activated and communicate with the sink. Therefore, they incur much overhead, loss of energy and reduced target tracking accuracy. In this paper, we have proposed a clustering algorithm, where distributed cluster heads coordinate their member nodes in optimizing the active sensing and communication directions of the nodes, precisely determining the target location by aggregating reported sensing data from multiple nodes and transferring the resultant location information to the sink. Thus, the proposed target tracking mechanism minimizes the sensing redundancy and maximizes the number of sleeping nodes in the network. We have also investigated the dynamic approach of activating sleeping nodes on-demand so that the moving target tracking accuracy can be enhanced while maximizing the network lifetime. We have carried out our extensive simulations in ns-3, and the results show that the proposed mechanism achieves higher performance compared to the state-of-the-art works.

Cooperative multi-robot observation of multiple moving targets

International Nuclear Information System (INIS)

Parker, L.E.; Emmons, B.A.

1997-01-01

An important issue that arises in the automation of many security, surveillance, and reconnaissance tasks is that of monitoring, or observing, the movements of targets navigating in a bounded area of interest. A key research issue in these problems is that of sensor placement--determining where sensors should be located to maintain the targets in view. In complex applications of this type, the use of multiple sensors dynamically moving over time is required. In this paper, the authors investigate the sue of a cooperative team of autonomous sensor-based robots for multi-robot observation of multiple moving targets. They focus primarily on developing the distributed control strategies that allow the robot team to attempt to maximize the collective tie during which each object is being observed by at least one robot in the area of interest. The initial efforts in this problem address the aspects of distributed control in homogeneous robot teams with equivalent sensing and movement capabilities working in an uncluttered, bounded area. This paper first formalizes the problem, discusses related work, and then shows that this problem is NP-hard. They then present a distributed approximate approach to solving this problem that combines low-level multi-robot control with higher-level control

The Building Blocks of Life Move from Ground to Tree to Animal and Back to Ground

Science.gov (United States)

Davidson, E. A.

2015-12-01

I generally use combinations of big words to describe my science, such as biogeochemistry, ecosystem ecology, nutrient cycling, stoichiometry, tropical deforestation, land-use change, agricultural intensification, eutrophication, greenhouse gas emissions, and sustainable development. I didn't expect to use any of these words, but I was surprised that I couldn't use some others that seem simple enough to me, such as farm, plant, soil, and forest. I landed on "building blocks" as my metaphor for the forms of carbon, nitrogen, phosphorus, and other elements that I study as they cycle through and among ecosystems. I study what makes trees and other kinds of life grow. We all know that they need the sun and that they take up water from the ground, but what else do trees need from the ground? What do animals that eat leaves and wood get from the trees? Just as we need building blocks to grow our bodies, trees and animals also need building blocks for growing their bodies. Trees get part of their building blocks from the ground and animals get theirs from what they eat. When animals poop and when leaves fall, some of their building blocks return to the ground. When they die, their building blocks also go back to the ground. I also study what happens to the ground, the water, and the air when we cut down trees, kill or shoo away the animals, and make fields to grow our food. Can we grow enough food and still keep the ground, water, and air clean? I think the answer is yes, but it will take better understanding of how all of those building blocks fit together and move around, from ground to tree to animal and back to ground.

Artificial ground motion compatible with specified peak ground displacement and target multi-damping response spectra

International Nuclear Information System (INIS)

Zhang Yushan; Zhao Fengxin

2010-01-01

With respect to the design ground motion of nuclear power plant (NPP), the Regular Guide 1.60 of the US not only defined the standard multi-damping response spectra, i.e. the RG1.60 spectra, but also definitely prescribed the peak ground displacement (PGD) value corresponding to the standard spectra. However, in the engineering practice of generating multi-damping-spectra-compatible artificial ground motion for the seismic design of NPP, the PGD value had been neglected. Addressing this issue, this paper proposed a synthesizing method which generates the artificial ground motion compatible with not only the target multi-damping response spectra but also the specified PGD value. Firstly, by the transfer formula between the power spectrum and the response spectrum, an initial uniformly modulated acceleration time history is synthesized by multiplying the stationary Gaussian process with the prescribed intensity envelope to simulate the amplitude-non-stationarity of earthquake ground motion. And then by superimposing a series of narrow-band time histories in the time domain, the initial time history is modified in the iterative manner to match the target PGD as well as the target multi-damping spectra with the pre-specified matching precisions. Numerical examples are provided to demonstrate the matching precisions of the proposed method to the target values.

Moving Target Tracking through Distributed Clustering in Directional Sensor Networks

Directory of Open Access Journals (Sweden)

Asma Enayet

2014-12-01

Full Text Available The problem of moving target tracking in directional sensor networks (DSNs introduces new research challenges, including optimal selection of sensing and communication sectors of the directional sensor nodes, determination of the precise location of the target and an energy-efficient data collection mechanism. Existing solutions allow individual sensor nodes to detect the target’s location through collaboration among neighboring nodes, where most of the sensors are activated and communicate with the sink. Therefore, they incur much overhead, loss of energy and reduced target tracking accuracy. In this paper, we have proposed a clustering algorithm, where distributed cluster heads coordinate their member nodes in optimizing the active sensing and communication directions of the nodes, precisely determining the target location by aggregating reported sensing data from multiple nodes and transferring the resultant location information to the sink. Thus, the proposed target tracking mechanism minimizes the sensing redundancy and maximizes the number of sleeping nodes in the network. We have also investigated the dynamic approach of activating sleeping nodes on-demand so that the moving target tracking accuracy can be enhanced while maximizing the network lifetime. We have carried out our extensive simulations in ns-3, and the results show that the proposed mechanism achieves higher performance compared to the state-of-the-art works.

A moving target for accelerated charged particle induced X-ray measurement

International Nuclear Information System (INIS)

Chuang, L.S.; Shima, K.; Ebihara, H.; Seki, R.; Mikumo, T.

1980-01-01

To attain good reproducibility as well as to enable an absolute determination in the measurement of X-ray fluorescences, resulting from bombardment of a heterogeneous sample by accelerated charged particles, a moving-target mechanism incorporating an electronic remote control system has been devised. The system is designed to scan the whole sample area with a chosen constant linear speed, by a fixed particle beam with a cross-sectional area a small fraction of that of the sample. Using 16 MeV protons and 40 MeV oxygen-ion beams, test runs of this system showed that the attempted objectives are attainable with good accuracies: reproducibility of the data for a given target is better than 3%, the linearity of the calibration curve is in good agreement, within the weighing errors of the standard elements and the uncertainty due to beam current fluctuation, with the expected values, and the results of absolute determinations using both metal foils and heterogeneous powder samples are in good agreement with accepted results using different methods. Detailed accounts of the moving-target system, and the test for reproducibility and linearity are presented. An absolute determination of the quantities related to accelerated charged-particle induced X-ray fluorescence (PIXE) using the moving target is presented for samples in different forms. (orig./HP)

The application of unattended ground sensors to stationary targets

International Nuclear Information System (INIS)

Sleefe, G.E.; Peglow, S.; Hamrick, R.

1997-01-01

The unattended sensing of stationary (i.e. non-mobile) targets is important in applications ranging from counter-proliferation to law enforcement. With stationary targets, sources of seismic, acoustic, and electro-magnetic emissions can potentially be used to detect, identify, and locate the target. Stationary targets have considerably different sensing requirements than the traditional mobile-target unattended ground sensor applications. This paper presents the novel features and requirements of a system for sensing stationary targets. In particular, issues associated with long-listen time signal processing for signal detection, and array processing techniques for signal localization are presented. Example data and signal processing outputs from a stationary target will be used to illustrate these issues. The impact on sensor, electronic signal processing, battery subsystem, and communication requirements will also be discussed. The paper will conclude with a detailed comparison between mobile-target and stationary-target unattended ground sensor architectures

Does the Brain Extrapolate the Position of a Transient Moving Target?

Science.gov (United States)

Quinet, Julie; Goffart, Laurent

2015-08-26

When an object moves in the visual field, its motion evokes a streak of activity on the retina and the incoming retinal signals lead to robust oculomotor commands because corrections are observed if the trajectory of the interceptive saccade is perturbed by a microstimulation in the superior colliculus. The present study complements a previous perturbation study by investigating, in the head-restrained monkey, the generation of saccades toward a transient moving target (100-200 ms). We tested whether the saccades land on the average of antecedent target positions or beyond the location where the target disappeared. Using target motions with different speed profiles, we also examined the sensitivity of the process that converts time-varying retinal signals into saccadic oculomotor commands. The results show that, for identical overall target displacements on the visual display, saccades toward a faster target land beyond the endpoint of saccades toward a target moving slower. The rate of change in speed matters in the visuomotor transformation. Indeed, in response to identical overall target displacements and durations, the saccades have smaller amplitude when they are made in response to an accelerating target than to a decelerating one. Moreover, the motion-related signals have different weights depending upon their timing relative to the target onset: early signals are more influential in the specification of saccade amplitude than later signals. We discuss the "predictive" properties of the visuo-saccadic system and the nature of this location where the saccades land, after providing some critical comments to the "hic-et-nunc" hypothesis (Fleuriet and Goffart, 2012). Complementing the work of Fleuriet and Goffart (2012), this study is a contribution to the more general scientific research aimed at understanding how ongoing action is dynamically and adaptively adjusted to the current spatiotemporal aspects of its goal. Using the saccadic eye movement as a probe

Moving Target Detection and Active Tracking with a Multicamera Network

Directory of Open Access Journals (Sweden)

Long Zhao

2014-01-01

Full Text Available We propose a systematic framework for Intelligence Video Surveillance System (IVSS with a multicamera network. The proposed framework consists of low-cost static and PTZ cameras, target detection and tracking algorithms, and a low-cost PTZ camera feedback control algorithm based on target information. The target detection and tracking is realized by fixed cameras using a moving target detection and tracking algorithm; the PTZ camera is manoeuvred to actively track the target from the tracking results of the static camera. The experiments are carried out using practical surveillance system data, and the experimental results show that the systematic framework and algorithms presented in this paper are efficient.

The search for an alerted moving target; 2005BU2-OA

NARCIS (Netherlands)

Vermeulen, J.F.J.; Brink, M. van den

2005-01-01

We investigate a two-sided, multi-stage search problem where a continuous search effort is made by one or more search units to detect a moving target in a continuous target space, under noisy detection conditions. A specific example of this problem is hunting for an enemy submarine by naval forces.

Saccadic foveation of a moving visual target in the rhesus monkey.

Science.gov (United States)

Fleuriet, Jérome; Hugues, Sandrine; Perrinet, Laurent; Goffart, Laurent

2011-02-01

When generating a saccade toward a moving target, the target displacement that occurs during the period spanning from its detection to the saccade end must be taken into account to accurately foveate the target and to initiate its pursuit. Previous studies have shown that these saccades are characterized by a lower peak velocity and a prolonged deceleration phase. In some cases, a second peak eye velocity appears during the deceleration phase, presumably reflecting the late influence of a mechanism that compensates for the target displacement occurring before saccade end. The goal of this work was to further determine in the head restrained monkey the dynamics of this putative compensatory mechanism. A step-ramp paradigm, where the target motion was orthogonal to a target step occurring along the primary axes, was used to estimate from the generated saccades: a component induced by the target step and another one induced by the target motion. Resulting oblique saccades were compared with saccades to a static target with matched horizontal and vertical amplitudes. This study permitted to estimate the time taken for visual motion-related signals to update the programming and execution of saccades. The amplitude of the motion-related component was slightly hypometric with an undershoot that increased with target speed. Moreover, it matched with the eccentricity that the target had 40-60 ms before saccade end. The lack of significant difference in the delay between the onsets of the horizontal and vertical components between saccades directed toward a static target and those aimed at a moving target questions the late influence of the compensatory mechanism. The results are discussed within the framework of the "dual drive" and "remapping" hypotheses.

DMPD: Fifty years of interferon research: aiming at a moving target. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available mmunity. 2006 Sep;25(3):343-8. (.png) (.svg) (.html) (.csml) Show Fifty years of interferon research: aiming at a moving target. Pubm...edID 16979566 Title Fifty years of interferon research: aiming at a moving target.

IMRT delivery to a moving target by dynamic MLC tracking: delivery for targets moving in two dimensions in the beam's eye view

International Nuclear Information System (INIS)

McQuaid, D; Webb, S

2006-01-01

A new modification of the dynamic multileaf collimator (dMLC) delivery technique for intensity-modulated therapy (IMRT) is outlined. This technique enables the tracking of a target moving through rigid-body translations in a 2D trajectory in the beam's eye view. The accuracy of the delivery versus that of deliveries with no tracking and of 1D tracking techniques is quantified with clinically derived intensity-modulated beams (IMBs). Leaf trajectories calculated in the target-reference frame were iteratively synchronized assuming regular target motion. This allowed the leaves defined in the lab-reference frame to simultaneously follow the target motion and to deliver the required IMB without violation of the leaf maximum-velocity constraint. The leaves are synchronized until the gradient of the leaf position at every instant is less than a calculated maximum. The delivered fluence in the target-reference frame was calculated with a simple primary-fluence model. The new 2D tracking technique was compared with the delivered fluence produced by no-tracking deliveries and by 1D tracking deliveries for 33 clinical IMBs. For the clinical IMBs normalized to a maximum fluence of 200 MUs, the rms difference between the desired and the delivered IMB was 15.6 ± 3.3 MU for the case of a no-tracking delivery, 7.9 ± 1.6 MU for the case where only the primary component of motion was corrected and 5.1 ± 1.1 MU for the 2D tracking delivery. The residual error is due to interpolation and sampling effects. The 2D tracking delivery technique requires an increase in the delivery time evaluated as between 0 and 50% of the unsynchronized delivery time for each beam with a mean increase of 13% for the IMBs tested. The 2D tracking dMLC delivery technique allows an optimized IMB to be delivered to moving targets with increased accuracy and with acceptable increases in delivery time. When combined with real-time knowledge of the target motion at delivery time, this technique facilitates

An indirect adaptive neural control of a visual-based quadrotor robot for pursuing a moving target.

Science.gov (United States)

Shirzadeh, Masoud; Amirkhani, Abdollah; Jalali, Aliakbar; Mosavi, Mohammad R

2015-11-01

This paper aims to use a visual-based control mechanism to control a quadrotor type aerial robot which is in pursuit of a moving target. The nonlinear nature of a quadrotor, on the one hand, and the difficulty of obtaining an exact model for it, on the other hand, constitute two serious challenges in designing a controller for this UAV. A potential solution for such problems is the use of intelligent control methods such as those that rely on artificial neural networks and other similar approaches. In addition to the two mentioned problems, another problem that emerges due to the moving nature of a target is the uncertainty that exists in the target image. By employing an artificial neural network with a Radial Basis Function (RBF) an indirect adaptive neural controller has been designed for a quadrotor robot in search of a moving target. The results of the simulation for different paths show that the quadrotor has efficiently tracked the moving target. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Moving Target Techniques: Cyber Resilience throught Randomization, Diversity, and Dynamism

Science.gov (United States)

2017-03-03

attacks. Simply put, these techniques turn systems into moving targets that will be hard for cyber attackers to compromise. MT techniques leverage...been diversified, they can attack it as if it was not diversified at all. Dynamic Data: Techniques in the dynamic data domain change the format

Neuromorphic Modeling of Moving Target Detection in Insects

Science.gov (United States)

2007-12-31

Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39, 18 Grants FA9550-04-1-0283 and FA9550-04-1-0294 Neuromorphic Modeling of Moving Target Detection...natural for neuromorphic sensory processing. We developed visual motion detection circuitry, including photodetectors, early vision, and models for both...Lincoln Labs 3DM2 run, Tanner Research reserved and utilized space corresponding to two MOSIS ’tiny chips ’ (2mm square each), each with three interconnected

Taking aim at a moving target: designing drugs to inhibit drug-resistant HIV-1 reverse transcriptases.

Science.gov (United States)

Sarafianos, Stefan G; Das, Kalyan; Hughes, Stephen H; Arnold, Eddy

2004-12-01

HIV undergoes rapid genetic variation; this variation is caused primarily by the enormous number of viruses produced daily in an infected individual. Because of this variation, HIV presents a moving target for drug and vaccine development. The variation within individuals has led to the generation of diverse HIV-1 subtypes, which further complicates the development of effective drugs and vaccines. In general, it is more difficult to hit a moving target than a stationary target. Two broad strategies for hitting a moving target (in this case, HIV replication) are to understand the movement and to aim at the portions that move the least. In the case of anti-HIV drug development, the first option can be addressed by understanding the mechanism(s) of drug resistance and developing drugs that effectively inhibit mutant viruses. The second can be addressed by designing drugs that interact with portions of the viral machinery that are evolutionarily conserved, such as enzyme active sites.

Moving target feature phenomenology data collection at China Lake

Science.gov (United States)

Gross, David C.; Hill, Jeff; Schmitz, James L.

2002-08-01

This paper describes the DARPA Moving Target Feature Phenomenology (MTFP) data collection conducted at the China Lake Naval Weapons Center's Junction Ranch in July 2001. The collection featured both X-band and Ku-band radars positioned on top of Junction Ranch's Parrot Peak. The test included seven targets used in eleven configurations with vehicle motion consisting of circular, straight-line, and 90-degree turning motion. Data was collected at 10-degree and 17-degree depression angles. Key parameters in the collection were polarization, vehicle speed, and road roughness. The collection also included a canonical target positioned at Junction Ranch's tilt-deck turntable. The canonical target included rotating wheels (military truck tire and civilian pick-up truck tire) and a flat plate with variable positioned corner reflectors. The canonical target was also used to simulate a rotating antenna and a vibrating plate. The target vehicles were instrumented with ARDS pods for differential GPS and roll, pitch and yaw measurements. Target motion was also documented using a video camera slaved to the X-band radar antenna and by a video camera operated near the target site.

Application of Fractional Fourier Transform to Moving Target Indication via Along-Track Interferometry

Directory of Open Access Journals (Sweden)

Chiu Shen

2005-01-01

Full Text Available A relatively unknown yet powerful technique, the so-called fractional Fourier transform (FrFT, is applied to SAR along-track interferometry (SAR-ATI in order to estimate moving target parameters. By mapping a target's signal onto a fractional Fourier axis, the FrFT permits a constant-velocity target to be focused in the fractional Fourier domain thereby affording orders of magnitude improvement in SCR. Moving target velocity and position parameters are derived and expressed in terms of an optimum fractional angle and a measured fractional Fourier position , allowing a target to be accurately repositioned and its velocity components computed without actually forming an SAR image. The new estimation algorithm is compared with the matched filter bank approach, showing some of the advantages of the FrFT method. The proposed technique is applied to the data acquired by the two-aperture CV580 airborne radar system configured in its along-track mode. Results show that the method is effective in estimating target velocity and position parameters.

Wideband Radar Echo Frequency-domain Simulation and Analysis for High Speed Moving Targets

Directory of Open Access Journals (Sweden)

Ning Chao

2014-04-01

Full Text Available A frequency-domain method is proposed for wideband radar echo simulation of high-speed moving targets. Based on the physical process of electromagnetic waves observing a moving target, a frequency-domain echo model of wideband radar is constructed, and the block diagram of the radar echo simulation in frequency-domain is presented. Then, the impacts of radial velocity and slant range on the matching filtering of LFM radar are analyzed, and some quantitative conclusions on the shift and expansion of the radar profiles are obtained. Simulation results illustrate the correctness and efficiency of the proposed method.

Ultrasound image based visual servoing for moving target ablation by high intensity focused ultrasound.

Science.gov (United States)

Seo, Joonho; Koizumi, Norihiro; Mitsuishi, Mamoru; Sugita, Naohiko

2017-12-01

Although high intensity focused ultrasound (HIFU) is a promising technology for tumor treatment, a moving abdominal target is still a challenge in current HIFU systems. In particular, respiratory-induced organ motion can reduce the treatment efficiency and negatively influence the treatment result. In this research, we present: (1) a methodology for integration of ultrasound (US) image based visual servoing in a HIFU system; and (2) the experimental results obtained using the developed system. In the visual servoing system, target motion is monitored by biplane US imaging and tracked in real time (40 Hz) by registration with a preoperative 3D model. The distance between the target and the current HIFU focal position is calculated in every US frame and a three-axis robot physically compensates for differences. Because simultaneous HIFU irradiation disturbs US target imaging, a sophisticated interlacing strategy was constructed. In the experiments, respiratory-induced organ motion was simulated in a water tank with a linear actuator and kidney-shaped phantom model. Motion compensation with HIFU irradiation was applied to the moving phantom model. Based on the experimental results, visual servoing exhibited a motion compensation accuracy of 1.7 mm (RMS) on average. Moreover, the integrated system could make a spherical HIFU-ablated lesion in the desired position of the respiratory-moving phantom model. We have demonstrated the feasibility of our US image based visual servoing technique in a HIFU system for moving target treatment. © 2016 The Authors The International Journal of Medical Robotics and Computer Assisted Surgery Published by John Wiley & Sons Ltd.

Spot Weight Adaptation for Moving Target in Spot Scanning Proton Therapy.

Science.gov (United States)

Morel, Paul; Wu, Xiaodong; Blin, Guillaume; Vialette, Stéphane; Flynn, Ryan; Hyer, Daniel; Wang, Dongxu

2015-01-01

This study describes a real-time spot weight adaptation method in spot-scanning proton therapy for moving target or moving patient, so that the resultant dose distribution closely matches the planned dose distribution. The method proposed in this study adapts the weight (MU) of the delivering pencil beam to that of the target spot; it will actually hit during patient/target motion. The target spot that a certain delivering pencil beam may hit relies on patient monitoring and/or motion modeling using four-dimensional (4D) CT. After the adapted delivery, the required total weight [Monitor Unit (MU)] for this target spot is then subtracted from the planned value. With continuous patient motion and continuous spot scanning, the planned doses to all target spots will eventually be all fulfilled. In a proof-of-principle test, a lung case was presented with realistic temporal and motion parameters; the resultant dose distribution using spot weight adaptation was compared to that without using this method. The impact of the real-time patient/target position tracking or prediction was also investigated. For moderate motion (i.e., mean amplitude 0.5 cm), D95% to the planning target volume (PTV) was only 81.5% of the prescription (RX) dose; with spot weight adaptation PTV D95% achieves 97.7% RX. For large motion amplitude (i.e., 1.5 cm), without spot weight adaptation PTV D95% is only 42.9% of RX; with spot weight adaptation, PTV D95% achieves 97.7% RX. Larger errors in patient/target position tracking or prediction led to worse final target coverage; an error of 3 mm or smaller in patient/target position tracking is preferred. The proposed spot weight adaptation method was able to deliver the planned dose distribution and maintain target coverage when patient motion was involved. The successful implementation of this method would rely on accurate monitoring or prediction of patient/target motion.

Spot Weight Adaptation for Moving Target in Spot Scanning Proton Therapy

Directory of Open Access Journals (Sweden)

Paul eMorel

2015-05-01

Full Text Available Purpose: This study describes a real-time spot weight adaptation method in spot-scanning proton therapy for moving target or moving patient, so that the resultant dose distribution closely matches the planned dose distribution. Materials and Methods: The method proposed in this study adapts the weight (MU of the delivering pencil beam to that of the target spot it will actually hit during patient/target motion. The target spot a certain delivering pencil beam may hit relies on patient monitoring and/or motion modeling using four-dimensional (4D CT. After the adapted delivery, the required total weight (MU for this target spot is then subtracted from the planned value. With continuous patient motion and continuous spot scanning, the planned doses to all target spots will eventually be all fulfilled. In a proof-of-principle test, a lung case was presented with realistic temporal and motion parameters; the resultant dose distribution using spot weight adaptation was compared to that without using this method. The impact of the real-time patient/target position tracking or prediction was also investigated.Results: For moderate motion (i.e., mean amplitude 0.5 cm, D95% to the planning target volume (PTV was only 81.5% of the prescription (RX dose; with spot weight adaptation PTV D95% achieves 97.7%RX. For large motion amplitude (i.e., 1.5 cm, without spot weight adaptation PTV D95% is only 42.9% of RX; with spot weight adaptation, PTV D95% achieves 97.7%RX. Larger errors in patient/target position tracking or prediction led to worse final target coverage; an error of 3mm or smaller in patient/target position tracking is preferred. Conclusion: The proposed spot weight adaptation method was able to deliver the planned dose distribution and maintain target coverage when patient motion was involved. The successful implementation of this method would rely on accurate monitoring or prediction of patient/target motion.

Study on moving target detection to passive radar based on FM broadcast transmitter

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Target detection by a noncooperative illuminator is a topic of general interest in the electronic warfare field.First of all,direct-path interference(DPI)suppression which is the technique of bottleneck of moving target detection by a noncooperative frequency modulation(FM) broadcast transmitter is analyzed in this article;Secondly,a space-time-frequency domain synthetic solution to this problem is introduced:Adaptive nulling array processing is considered in the space domain,DPI cancellation based on adaptive fractional delay interpolation(AFDI)technique is used in planned time domain,and long-time coherent integration is utilized in the frequency domain;Finally,an experimental system is planned by considering FM broadcast transmitter as a noncooperative illuminator,Simulation results by real collected data show that the proposed method has a better performance of moving target detection.

Vision-Based Target Finding and Inspection of a Ground Target Using a Multirotor UAV System.

Science.gov (United States)

Hinas, Ajmal; Roberts, Jonathan M; Gonzalez, Felipe

2017-12-17

In this paper, a system that uses an algorithm for target detection and navigation and a multirotor Unmanned Aerial Vehicle (UAV) for finding a ground target and inspecting it closely is presented. The system can also be used for accurate and safe delivery of payloads or spot spraying applications in site-specific crop management. A downward-looking camera attached to a multirotor is used to find the target on the ground. The UAV descends to the target and hovers above the target for a few seconds to inspect the target. A high-level decision algorithm based on an OODA (observe, orient, decide, and act) loop was developed as a solution to address the problem. Navigation of the UAV was achieved by continuously sending local position messages to the autopilot via Mavros. The proposed system performed hovering above the target in three different stages: locate, descend, and hover. The system was tested in multiple trials, in simulations and outdoor tests, from heights of 10 m to 40 m. Results show that the system is highly reliable and robust to sensor errors, drift, and external disturbance.

Tracking and Recognition of Multiple Human Targets Moving in a Wireless Pyroelectric Infrared Sensor Network

Directory of Open Access Journals (Sweden)

Ji Xiong

2014-04-01

Full Text Available With characteristics of low-cost and easy deployment, the distributed wireless pyroelectric infrared sensor network has attracted extensive interest, which aims to make it an alternate infrared video sensor in thermal biometric applications for tracking and identifying human targets. In these applications, effectively processing signals collected from sensors and extracting the features of different human targets has become crucial. This paper proposes the application of empirical mode decomposition and the Hilbert-Huang transform to extract features of moving human targets both in the time domain and the frequency domain. Moreover, the support vector machine is selected as the classifier. The experimental results demonstrate that by using this method the identification rates of multiple moving human targets are around 90%.

Slower resting alpha frequency is associated with superior localisation of moving targets.

Science.gov (United States)

Howard, Christina J; Arnold, Craig P A; Belmonte, Matthew K

2017-10-01

We examined the neurophysiological underpinnings of individual differences in the ability to maintain up-to-date representations of the positions of moving objects. In two experiments similar to the multiple object tracking (MOT) task, we asked observers to monitor continuously one or several targets as they moved unpredictably for a semi-random period. After all objects disappeared, observers were immediately prompted to report the perceived final position of one queried target. Precision of these position reports declined with attentional load, and reports tended to best resemble positions occupied by the queried target between 0 and 30ms in the past. Measurement of event-related potentials showed a contralateral delay activity over occipital scalp, maximal in the right hemisphere. The peak power-spectral frequency of observers' eyes-closed resting occipital alpha oscillations reliably predicted performance, such that lower-frequency alpha was associated with superior spatial localisation. Slower resting alpha might be associated with a cognitive style that depends less on memory-related processing and instead emphasises attention to changing stimuli. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Multiple operating system rotation environment moving target defense

Science.gov (United States)

Evans, Nathaniel; Thompson, Michael

2016-03-22

Systems and methods for providing a multiple operating system rotation environment ("MORE") moving target defense ("MTD") computing system are described. The MORE-MTD system provides enhanced computer system security through a rotation of multiple operating systems. The MORE-MTD system increases attacker uncertainty, increases the cost of attacking the system, reduces the likelihood of an attacker locating a vulnerability, and reduces the exposure time of any located vulnerability. The MORE-MTD environment is effectuated by rotation of the operating systems at a given interval. The rotating operating systems create a consistently changing attack surface for remote attackers.

Familiar trajectories facilitate the interpretation of physical forces when intercepting a moving target.

Science.gov (United States)

Mijatović, Antonija; La Scaleia, Barbara; Mercuri, Nicola; Lacquaniti, Francesco; Zago, Myrka

2014-12-01

Familiarity with the visual environment affects our expectations about the objects in a scene, aiding in recognition and interaction. Here we tested whether the familiarity with the specific trajectory followed by a moving target facilitates the interpretation of the effects of underlying physical forces. Participants intercepted a target sliding down either an inclined plane or a tautochrone. Gravity accelerated the target by the same amount in both cases, but the inclined plane represented a familiar trajectory whereas the tautochrone was unfamiliar to the participants. In separate sessions, the gravity field was consistent with either natural gravity or artificial reversed gravity. Target motion was occluded from view over the last segment. We found that the responses in the session with unnatural forces were systematically delayed relative to those with natural forces, but only for the inclined plane. The time shift is consistent with a bias for natural gravity, in so far as it reflects an a priori expectation that a target not affected by natural forces will arrive later than one accelerated downwards by gravity. Instead, we did not find any significant time shift with unnatural forces in the case of the tautochrone. We argue that interception of a moving target relies on the integration of the high-level cue of trajectory familiarity with low-level cues related to target kinematics.

VHF/UHF imagery and RCS measurements of ground targets in forested terrain

Science.gov (United States)

Gatesman, Andrew J.; Beaudoin, Christopher J.; Giles, Robert H.; Waldman, Jerry; Nixon, William E.

2002-08-01

The monostatic VV and HH-polarized radar signatures of several targets and trees have been measured at foliage penetration frequencies (VHF/UHF) by using 1/35th scale models and an indoor radar range operating at X-band. An array of high-fidelity scale model ground vehicles and test objects as well as scaled ground terrain and trees have been fabricated for the study. Radar measurement accuracy has been confirmed by comparing the signature of a test object with a method of moments radar cross section prediction code. In addition to acquiring signatures of targets located on a smooth, dielectric ground plane, data have also been acquired with targets located in simulated wooded terrain that included scaled tree trunks and tree branches. In order to assure the correct backscattering behavior, all dielectric properties of live tree wood and moist soil were scaled properly to match the complex dielectric constant of the full-scale materials. The impact of the surrounding tree clutter on the VHF/UHF radar signatures of ground vehicles was accessed. Data were processed into high-resolution, polar-formatted ISAR imagery and signature comparisons are made between targets in open-field and forested scenarios.

Hic-Et-Nunc (Here-and-Now Encoding of a Moving Target for its Saccadic Foveation

Directory of Open Access Journals (Sweden)

Laurent Goffart

2012-10-01

Full Text Available The neural representation of a moving target undergoes a spatiotemporal “diffusion” while the associated retinal activity propagates toward the motor centers and recruits the appropriate muscles for its interception in the external world. Indeed, the divergent projections within the visual system and the transmissions of signals through multiple relays, with diverse conduction velocities and integration times, lead to activities that are spatially and temporally distributed across several brain regions. In spite of this neural “blurring”, accurate saccadic eye movements can be made to bring the image of a moving target onto the fovea. Such a performance indicates that the brain is able to rapidly estimate the current spatiotemporal coordinates of the target, at least at the time of saccade landing. We tested in the monkey the robustness of this estimate when a change in eye position and a delay are experimentally added before the animal launches a saccade toward a moving target and in the absence of visual feedback. These spatiotemporal perturbations were induced by a brief microstimulation in the deep superior colliculus. The results show that the interceptive saccades can remain accurate and relatively independent of the time taken to react and to foveate the target. We propose that the brain builds an estimate of the expected and current spatiotemporal (hic-et-nunc coordinates of the target and that this signal feeds the same local feedback loop as the mechanism proposed for guiding saccades toward a stationary target (Fleuriet and Goffart, 2012 Journal of Neuroscience 32 452–461.

DMLC motion tracking of moving targets for intensity modulated arc therapy treatment

DEFF Research Database (Denmark)

Zimmerman, Jens; Korreman, Stine; Persson, Gitte

2009-01-01

(DMLC). The aim of this work was to evaluate the dose delivered to moving targets using the RapidArc (Varian Medical Systems, Inc.) technology with and without a DMLC tracking algorithm. MATERIAL AND METHODS: A Varian Clinac iX was equipped with a preclinical RapidArc and a 3D DMLC tracking application......) and state (1). CONCLUSIONS: DMLC tracking together with RapidArc make a feasible combination and is capable of improving the dose distribution delivered to a moving target. It seems to be of importance to minimize noise influencing the tracking, to gain the full benefit from the application........ A motion platform was placed on the couch, with the detectors on top: a PTW seven29 and a Scandidos Delta4. One lung plan and one prostate plan were delivered. Motion was monitored using a Real-time Position Management (RPM) system. Reference measurements were performed for both plans with both detectors...

Moving Target Photometry Using WISE and NEOWISE

Science.gov (United States)

Wright, Edward L.

2015-01-01

WISE band 1 observations have a significant noise contribution from confusion. The image subtraction done on W0855-0714 by Wright et al. (2014) shows that this noise source can be eliminated for sources that move by much more than the beamsize. This paper describes an analysis that includes a pattern of celestially fixed flux plus a source moving with a known trajectory. This technique allows the confusion noise to be modeled with nuisance parameters and removed even for sources that have not moved by many beamwidths. However, the detector noise is magnified if the motion is too small. Examples of the method applied to fast moving Y dwarfs and slow moving planets will be shown.

Research on Ground Motion Metal Target Based on Rocket Projectile by Using Millimeter Wave Radiometer Technology

Directory of Open Access Journals (Sweden)

Zhang Dongyang

2014-06-01

Full Text Available How to detect the ground motion metal target effectively is an important guarantee for precision strike in the process of Rocket Projectile flight. Accordingly and in view of the millimeter- wave radiation characteristic of the ground motion metal target, a mathematical model was established based on Rocket Projectile about millimeter-wave detection to the ground motion metal target. Through changing various parameters in the process of Rocket Projectile flight, the detection model was studied by simulation. The parameters variation and effective range of millimeter wave radiometer were obtained in the process of rotation and horizontal flight. So a certain theoretical basis was formed for the precision strike to the ground motion metal target.

3D range-gated super-resolution imaging based on stereo matching for moving platforms and targets

Science.gov (United States)

Sun, Liang; Wang, Xinwei; Zhou, Yan

2017-11-01

3D range-gated superresolution imaging is a novel 3D reconstruction technique for target detection and recognition with good real-time performance. However, for moving targets or platforms such as airborne, shipborne, remote operated vehicle and autonomous vehicle, 3D reconstruction has a large error or failure. In order to overcome this drawback, we propose a method of stereo matching for 3D range-gated superresolution reconstruction algorithm. In experiment, the target is a doll of Mario with a height of 38cm at the location of 34m, and we obtain two successive frame images of the Mario. To confirm our method is effective, we transform the original images with translation, rotation, scale and perspective, respectively. The experimental result shows that our method has a good result of 3D reconstruction for moving targets or platforms.

An Adaptive Moving Target Imaging Method for Bistatic Forward-Looking SAR Using Keystone Transform and Optimization NLCS.

Science.gov (United States)

Li, Zhongyu; Wu, Junjie; Huang, Yulin; Yang, Haiguang; Yang, Jianyu

2017-01-23

Bistatic forward-looking SAR (BFSAR) is a kind of bistatic synthetic aperture radar (SAR) system that can image forward-looking terrain in the flight direction of an aircraft. Until now, BFSAR imaging theories and methods for a stationary scene have been researched thoroughly. However, for moving-target imaging with BFSAR, the non-cooperative movement of the moving target induces some new issues: (I) large and unknown range cell migration (RCM) (including range walk and high-order RCM); (II) the spatial-variances of the Doppler parameters (including the Doppler centroid and high-order Doppler) are not only unknown, but also nonlinear for different point-scatterers. In this paper, we put forward an adaptive moving-target imaging method for BFSAR. First, the large and unknown range walk is corrected by applying keystone transform over the whole received echo, and then, the relationships among the unknown high-order RCM, the nonlinear spatial-variances of the Doppler parameters, and the speed of the mover, are established. After that, using an optimization nonlinear chirp scaling (NLCS) technique, not only can the unknown high-order RCM be accurately corrected, but also the nonlinear spatial-variances of the Doppler parameters can be balanced. At last, a high-order polynomial filter is applied to compress the whole azimuth data of the moving target. Numerical simulations verify the effectiveness of the proposed method.

An Adaptive Moving Target Imaging Method for Bistatic Forward-Looking SAR Using Keystone Transform and Optimization NLCS

Directory of Open Access Journals (Sweden)

Zhongyu Li

2017-01-01

Full Text Available Bistatic forward-looking SAR (BFSAR is a kind of bistatic synthetic aperture radar (SAR system that can image forward-looking terrain in the flight direction of an aircraft. Until now, BFSAR imaging theories and methods for a stationary scene have been researched thoroughly. However, for moving-target imaging with BFSAR, the non-cooperative movement of the moving target induces some new issues: (I large and unknown range cell migration (RCM (including range walk and high-order RCM; (II the spatial-variances of the Doppler parameters (including the Doppler centroid and high-order Doppler are not only unknown, but also nonlinear for different point-scatterers. In this paper, we put forward an adaptive moving-target imaging method for BFSAR. First, the large and unknown range walk is corrected by applying keystone transform over the whole received echo, and then, the relationships among the unknown high-order RCM, the nonlinear spatial-variances of the Doppler parameters, and the speed of the mover, are established. After that, using an optimization nonlinear chirp scaling (NLCS technique, not only can the unknown high-order RCM be accurately corrected, but also the nonlinear spatial-variances of the Doppler parameters can be balanced. At last, a high-order polynomial filter is applied to compress the whole azimuth data of the moving target. Numerical simulations verify the effectiveness of the proposed method.

Deployment Design of Wireless Sensor Network for Simple Multi-Point Surveillance of a Moving Target

Science.gov (United States)

Tsukamoto, Kazuya; Ueda, Hirofumi; Tamura, Hitomi; Kawahara, Kenji; Oie, Yuji

2009-01-01

In this paper, we focus on the problem of tracking a moving target in a wireless sensor network (WSN), in which the capability of each sensor is relatively limited, to construct large-scale WSNs at a reasonable cost. We first propose two simple multi-point surveillance schemes for a moving target in a WSN and demonstrate that one of the schemes can achieve high tracking probability with low power consumption. In addition, we examine the relationship between tracking probability and sensor density through simulations, and then derive an approximate expression representing the relationship. As the results, we present guidelines for sensor density, tracking probability, and the number of monitoring sensors that satisfy a variety of application demands. PMID:22412326

Margin estimation and disturbances of irradiation field in layer-stacking carbon-ion beams for respiratory moving targets.

Science.gov (United States)

Tajiri, Shinya; Tashiro, Mutsumi; Mizukami, Tomohiro; Tsukishima, Chihiro; Torikoshi, Masami; Kanai, Tatsuaki

2017-11-01

Carbon-ion therapy by layer-stacking irradiation for static targets has been practised in clinical treatments. In order to apply this technique to a moving target, disturbances of carbon-ion dose distributions due to respiratory motion have been studied based on the measurement using a respiratory motion phantom, and the margin estimation given by the square root of the summation Internal margin2+Setup margin2 has been assessed. We assessed the volume in which the variation in the ratio of the dose for a target moving due to respiration relative to the dose for a static target was within 5%. The margins were insufficient for use with layer-stacking irradiation of a moving target, and an additional margin was required. The lateral movement of a target converts to the range variation, as the thickness of the range compensator changes with the movement of the target. Although the additional margin changes according to the shape of the ridge filter, dose uniformity of 5% can be achieved for a spherical target 93 mm in diameter when the upward range variation is limited to 5 mm and the additional margin of 2.5 mm is applied in case of our ridge filter. Dose uniformity in a clinical target largely depends on the shape of the mini-peak as well as on the bolus shape. We have shown the relationship between range variation and dose uniformity. In actual therapy, the upper limit of target movement should be considered by assessing the bolus shape. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

An efficient method of fuel ice formation in moving free-standing ICF/IFE targets

Science.gov (United States)

Aleksandrova, I. V.; Bazdenkov, S. V.; Chtcherbakov, V. I.; Gromov, A. I.; Koresheva, E. R.; Koshelev, E. A.; Osipov, I. E.; Yaguzinskiy, L. S.

2004-04-01

Currently, research fields related to the elaboration of efficient layering methods for ICF/IFE applications are rapidly expanding. Significant progress has been made in the technology development based on rapid fuel layering inside moving free-standing targets (FST) which is referred to as the FST layering method. This paper presents our new results obtained in this area and describes technologically elegant solutions towards demonstrating a credible pathway for mass production of IFE cryogenic targets.

An efficient method of fuel ice formation in moving free-standing ICF/IFE targets

International Nuclear Information System (INIS)

Aleksandrova, I V; Bazdenkov, S V; Chtcherbakov, V I; Gromov, A I; Koresheva, E R; Koshelev, E A; Osipov, I E; Yaguzinskiy, L S

2004-01-01

Currently, research fields related to the elaboration of efficient layering methods for ICF/IFE applications are rapidly expanding. Significant progress has been made in the technology development based on rapid fuel layering inside moving free-standing targets (FST) which is referred to as the FST layering method. This paper presents our new results obtained in this area and describes technologically elegant solutions towards demonstrating a credible pathway for mass production of IFE cryogenic targets

Autonomous Landing on Moving Platforms

KAUST Repository

Mendoza Chavez, Gilberto

2016-08-01

This thesis investigates autonomous landing of a micro air vehicle (MAV) on a nonstationary ground platform. Unmanned aerial vehicles (UAVs) and micro air vehicles (MAVs) are becoming every day more ubiquitous. Nonetheless, many applications still require specialized human pilots or supervisors. Current research is focusing on augmenting the scope of tasks that these vehicles are able to accomplish autonomously. Precise autonomous landing on moving platforms is essential for self-deployment and recovery of MAVs, but it remains a challenging task for both autonomous and piloted vehicles. Model Predictive Control (MPC) is a widely used and effective scheme to control constrained systems. One of its variants, output-feedback tube-based MPC, ensures robust stability for systems with bounded disturbances under system state reconstruction. This thesis proposes a MAV control strategy based on this variant of MPC to perform rapid and precise autonomous landing on moving targets whose nominal (uncommitted) trajectory and velocity are slowly varying. The proposed approach is demonstrated on an experimental setup.

Engaging a moving target: Adapting to rates of climate change

Science.gov (United States)

Shayegh, S.; Caldeira, K.; Moreno-Cruz, J.

2015-12-01

Climate change is affecting the planet and its human and natural systems at an increasing rate. As temperatures continue to rise, the international community has increasingly been considering adaptation measures to prepare for future climate change. However, most discussion around adaptation strategies has focused on preparedness for some expected amount of climate change impacts, e.g. 2 meters sea level rise. In this study, we discuss adaptation to rates of change as an alternative conceptual framework for thinking about adaptation. Adaptation is not only about adapting to amounts of change, but the rate at which these changes occur is also critically important. We ground our discussion with an example of optimal coastal investment in the face of ongoing sea level rise. Sea level rise threatens coastal assets. Finite resources could be devoted to building infrastructure further inland or to building coastal defense systems. A possible policy response could be to create a "no-build" coastal buffer zone that anticipates a future higher sea level. We present a quantitative model that illustrates the interplay among various important factors (rate of sea level rise, discount rate, capital depreciation rate, attractiveness of coastal land, etc). For some cases, strategies that combine periodic defensive investments (e.g. dikes) with planned retreat can maximize welfare when adapting to rates of climate change. In other cases, planned retreat may be optimal. It is important to prepare for ongoing increasing amounts of climate change. Preparing for a fixed amount of climate change can lead to a suboptimal solution. Climate is likely to continue changing throughout this century and beyond. To reduce adverse climate impacts, ecosystems and human systems will need to continuously adapt to a moving target.

Final Report for Bio-Inspired Approaches to Moving-Target Defense Strategies

Energy Technology Data Exchange (ETDEWEB)

Fink, Glenn A.; Oehmen, Christopher S.

2012-09-01

This report records the work and contributions of the NITRD-funded Bio-Inspired Approaches to Moving-Target Defense Strategies project performed by Pacific Northwest National Laboratory under the technical guidance of the National Security Agency’s R6 division. The project has incorporated a number of bio-inspired cyber defensive technologies within an elastic framework provided by the Digital Ants. This project has created the first scalable, real-world prototype of the Digital Ants Framework (DAF)[11] and integrated five technologies into this flexible, decentralized framework: (1) Ant-Based Cyber Defense (ABCD), (2) Behavioral Indicators, (3) Bioinformatic Clas- sification, (4) Moving-Target Reconfiguration, and (5) Ambient Collaboration. The DAF can be used operationally to decentralize many such data intensive applications that normally rely on collection of large amounts of data in a central repository. In this work, we have shown how these component applications may be decentralized and may perform analysis at the edge. Operationally, this will enable analytics to scale far beyond current limitations while not suffering from the bandwidth or computational limitations of centralized analysis. This effort has advanced the R6 Cyber Security research program to secure digital infrastructures by developing a dynamic means to adaptively defend complex cyber systems. We hope that this work will benefit both our client’s efforts in system behavior modeling and cyber security to the overall benefit of the nation.

Optical angular constancy is maintained as a navigational control strategy when pursuing robots moving along complex pathways.

Science.gov (United States)

Wang, Wei; McBeath, Michael K; Sugar, Thomas G

2015-03-24

The optical navigational control strategy used to intercept moving targets was explored using a real-world object that travels along complex, evasive pathways. Fielders ran across a gymnasium attempting to catch a moving robot that varied in speed and direction, while ongoing position was measured using an infrared motion-capture system. Fielder running paths were compared with the predictions of three lateral control models, each based on maintaining a particular optical angle relative to the robotic target: (a) constant alignment angle (CAA), (b) constant eccentricity angle (CEA), and (c) linear optical trajectory (LOT). Findings reveal that running pathways were most consistent with maintenance of LOT and least consistent with CEA. This supports that fielders use the same optical control strategy of maintaining angular constancy using a LOT when navigating toward targets moving along complex pathways as when intercepting simple ballistic trajectories. In those cases in which a target dramatically deviates from its optical path, fielders appear to simply reset LOT parameters using a new constant angle value. Maintenance of such optical angular constancy has now been shown to work well with ballistic, complex, and evasive moving targets, confirming the LOT strategy as a robust, general-purpose optical control mechanism for navigating to intercept catchable targets, both airborne and ground based. © 2015 ARVO.

Detection of Fast Moving and Accelerating Targets Compensating Range and Doppler Migration

Science.gov (United States)

2014-06-01

TR–2978 UNCLASSIFIED the chirp bandwidth is changed from pulse to pulse to realise the range migration com- pensation. Also, Dai et. al. [11] proposed...injected at different closing velocities and acceleration values . Figure 1(a) shows the range-Doppler map of a non-accelarating target moving at 100 knots...increase the noise floor. Hence, consideration must be given to establish a criteria for the combination processing to achieve a net SNR improvement for a

Catching moving targets: cancer stem cell hierarchies, therapy-resistance & considerations for clinical intervention.

LENUS (Irish Health Repository)

Gasch, Claudia

2017-01-01

It is widely believed that targeting the tumour-initiating cancer stem cell (CSC) component of malignancy has great therapeutic potential, particularly in therapy-resistant disease. However, despite concerted efforts, CSC-targeting strategies have not been efficiently translated to the clinic. This is partly due to our incomplete understanding of the mechanisms underlying CSC therapy-resistance. In particular, the relationship between therapy-resistance and the organisation of CSCs as Stem-Progenitor-Differentiated cell hierarchies has not been widely studied. In this review we argue that modern clinical strategies should appreciate that the CSC hierarchy is a dynamic target that contains sensitive and resistant components and expresses a collection of therapy-resisting mechanisms. We propose that the CSC hierarchy at primary presentation changes in response to clinical intervention, resulting in a recurrent malignancy that should be targeted differently. As such, addressing the hierarchical organisation of CSCs into our bench-side theory should expedite translation of CSC-targeting to bed-side practice. In conclusion, we discuss strategies through which we can catch these moving clinical targets to specifically compromise therapy-resistant disease.

Moving-Target Position Estimation Using GPU-Based Particle Filter for IoT Sensing Applications

Directory of Open Access Journals (Sweden)

Seongseop Kim

2017-11-01

Full Text Available A particle filter (PF has been introduced for effective position estimation of moving targets for non-Gaussian and nonlinear systems. The time difference of arrival (TDOA method using acoustic sensor array has normally been used to for estimation by concealing the location of a moving target, especially underwater. In this paper, we propose a GPU -based acceleration of target position estimation using a PF and propose an efficient system and software architecture. The proposed graphic processing unit (GPU-based algorithm has more advantages in applying PF signal processing to a target system, which consists of large-scale Internet of Things (IoT-driven sensors because of the parallelization which is scalable. For the TDOA measurement from the acoustic sensor array, we use the generalized cross correlation phase transform (GCC-PHAT method to obtain the correlation coefficient of the signal using Fast Fourier Transform (FFT, and we try to accelerate the calculations of GCC-PHAT based TDOA measurements using FFT with GPU compute unified device architecture (CUDA. The proposed approach utilizes a parallelization method in the target position estimation algorithm using GPU-based PF processing. In addition, it could efficiently estimate sudden movement change of the target using GPU-based parallel computing which also can be used for multiple target tracking. It also provides scalability in extending the detection algorithm according to the increase of the number of sensors. Therefore, the proposed architecture can be applied in IoT sensing applications with a large number of sensors. The target estimation algorithm was verified using MATLAB and implemented using GPU CUDA. We implemented the proposed signal processing acceleration system using target GPU to analyze in terms of execution time. The execution time of the algorithm is reduced by 55% from to the CPU standalone operation in target embedded board, NVIDIA Jetson TX1. Also, to apply large

Verification of target motion effects on SAR imagery using the Gotcha GMTI challenge dataset

Science.gov (United States)

Hack, Dan E.; Saville, Michael A.

2010-04-01

This paper investigates the relationship between a ground moving target's kinematic state and its SAR image. While effects such as cross-range offset, defocus, and smearing appear well understood, their derivations in the literature typically employ simplifications of the radar/target geometry and assume point scattering targets. This study adopts a geometrical model for understanding target motion effects in SAR imagery, termed the target migration path, and focuses on experimental verification of predicted motion effects using both simulated and empirical datasets based on the Gotcha GMTI challenge dataset. Specifically, moving target imagery is generated from three data sources: first, simulated phase history for a moving point target; second, simulated phase history for a moving vehicle derived from a simulated Mazda MPV X-band signature; and third, empirical phase history from the Gotcha GMTI challenge dataset. Both simulated target trajectories match the truth GPS target position history from the Gotcha GMTI challenge dataset, allowing direct comparison between all three imagery sets and the predicted target migration path. This paper concludes with a discussion of the parallels between the target migration path and the measurement model within a Kalman filtering framework, followed by conclusions.

Infrared Small Moving Target Detection via Saliency Histogram and Geometrical Invariability

Directory of Open Access Journals (Sweden)

Minjie Wan

2017-06-01

Full Text Available In order to detect both bright and dark small moving targets effectively in infrared (IR video sequences, a saliency histogram and geometrical invariability based method is presented in this paper. First, a saliency map that roughly highlights the salient regions of the original image is obtained by tuning its amplitude spectrum in the frequency domain. Then, a saliency histogram is constructed by means of averaging the accumulated saliency value of each gray level in the map, through which bins corresponding to bright target and dark target are assigned with large values in the histogram. Next, single-frame detection of candidate targets is accomplished by a binarized segmentation using an adaptive threshold, and their centroid coordinates with sub-pixel accuracy are calculated through a connected components labeling method as well as a gray-weighted criterion. Finally, considering the motion characteristics in consecutive frames, an inter-frame false alarm suppression method based on geometrical invariability is developed to improve the precision rate further. Quantitative analyses demonstrate the detecting precision of this proposed approach can be up to 97% and Receiver Operating Characteristic (ROC curves further verify our method outperforms other state-of-the-arts methods in both detection rate and false alarm rate.

Dynamic-MLC leaf control utilizing on-flight intensity calculations: A robust method for real-time IMRT delivery over moving rigid targets

International Nuclear Information System (INIS)

McMahon, Ryan; Papiez, Lech; Rangaraj, Dharanipathy

2007-01-01

An algorithm is presented that allows for the control of multileaf collimation (MLC) leaves based entirely on real-time calculations of the intensity delivered over the target. The algorithm is capable of efficiently correcting generalized delivery errors without requiring the interruption of delivery (self-correcting trajectories), where a generalized delivery error represents anything that causes a discrepancy between the delivered and intended intensity profiles. The intensity actually delivered over the target is continually compared to its intended value. For each pair of leaves, these comparisons are used to guide the control of the following leaf and keep this discrepancy below a user-specified value. To demonstrate the basic principles of the algorithm, results of corrected delivery are shown for a leading leaf positional error during dynamic-MLC (DMLC) IMRT delivery over a rigid moving target. It is then shown that, with slight modifications, the algorithm can be used to track moving targets in real time. The primary results of this article indicate that the algorithm is capable of accurately delivering DMLC IMRT over a rigid moving target whose motion is (1) completely unknown prior to delivery and (2) not faster than the maximum MLC leaf velocity over extended periods of time. These capabilities are demonstrated for clinically derived intensity profiles and actual tumor motion data, including situations when the target moves in some instances faster than the maximum admissible MLC leaf velocity. The results show that using the algorithm while calculating the delivered intensity every 50 ms will provide a good level of accuracy when delivering IMRT over a rigid moving target translating along the direction of MLC leaf travel. When the maximum velocities of the MLC leaves and target were 4 and 4.2 cm/s, respectively, the resulting error in the two intensity profiles used was 0.1±3.1% and -0.5±2.8% relative to the maximum of the intensity profiles. For

Modified linear predictive coding approach for moving target tracking by Doppler radar

Science.gov (United States)

Ding, Yipeng; Lin, Xiaoyi; Sun, Ke-Hui; Xu, Xue-Mei; Liu, Xi-Yao

2016-07-01

Doppler radar is a cost-effective tool for moving target tracking, which can support a large range of civilian and military applications. A modified linear predictive coding (LPC) approach is proposed to increase the target localization accuracy of the Doppler radar. Based on the time-frequency analysis of the received echo, the proposed approach first real-time estimates the noise statistical parameters and constructs an adaptive filter to intelligently suppress the noise interference. Then, a linear predictive model is applied to extend the available data, which can help improve the resolution of the target localization result. Compared with the traditional LPC method, which empirically decides the extension data length, the proposed approach develops an error array to evaluate the prediction accuracy and thus, adjust the optimum extension data length intelligently. Finally, the prediction error array is superimposed with the predictor output to correct the prediction error. A series of experiments are conducted to illustrate the validity and performance of the proposed techniques.

A signature correlation study of ground target VHF/UHF ISAR imagery

Science.gov (United States)

Gatesman, Andrew J.; Beaudoin, Christopher J.; Giles, Robert H.; Kersey, William T.; Waldman, Jerry; Carter, Steve; Nixon, William E.

2003-09-01

VV and HH-polarized radar signatures of several ground targets were acquired in the VHF/UHF band (171-342 MHz) by using 1/35th scale models and an indoor radar range operating from 6 to 12 GHz. Data were processed into medianized radar cross sections as well as focused, ISAR imagery. Measurement validation was confirmed by comparing the radar cross section of a test object with a method of moments radar cross section prediction code. The signatures of several vehicles from three vehicle classes (tanks, trunks, and TELs) were measured and a signature cross-correlation study was performed. The VHF/UHF band is currently being exploited for its foliage penetration ability, however, the coarse image resolution which results from the relatively long radar wavelengths suggests a more challenging target recognition problem. One of the study's goals was to determine the amount of unique signature content in VHF/UHF ISAR imagery of military ground vehicles. Open-field signatures are compared with each other as well as with simplified shapes of similar size. Signatures were also acquired on one vehicle in a variety of configurations to determine the impact of monitor target variations on the signature content at these frequencies.

Management of the interplay effect when using dynamic MLC sequences to treat moving targets

International Nuclear Information System (INIS)

Court, Laurence E.; Wagar, Matthew; Ionascu, Dan; Berbeco, Ross; Chin, Lee

2008-01-01

Interplay between organ motion and leaf motion has been shown to generally have a small dosimetric impact for most clinical intensity-modulated radiation therapy treatments. However, it has also been shown that for some MLC sequences there can be large daily variations in the delivered dose, depending on details of patient motion or the number of fractions. This study investigates guidelines for dynamic MLC sequences that will keep daily dose variations due to the interplay between organ motion and leaf motion within 10%. Dose distributions for a range of MLC separations (0.2-5.0 cm) and displacements between adjacent MLCs (0-1.5 cm) were exported from ECLIPSE to purpose-written software, which simulated the dose distribution delivered to a moving target. Target motion parallel and perpendicular to the MLC motion was investigated for a range of amplitudes (0.5-4.0 cm), periods (1.5-10 s), and MLC speeds (0.1-3.0 cm/s) with target motions modeled as sin 6 . Results were confirmed experimentally by measuring the dose delivered to an ion chamber array in a moving phantom for different MLC sequences. The simulation results were used to identify MLC sequences that kept dose variations within 10% compared to the dose delivered with no motion. The maximum allowable MLC speed, when target motion is parallel to the MLC motion, was found to be a simple function of target period and MLC separation. When the target motion is perpendicular to MLC motion, the maximum allowable MLC speed can be described as a function of MLC separation and the displacement of adjacent MLCs. These guidelines were successfully applied to two-dimensional motion, and a simple program was written to import MLC sequence files and evaluate whether the maximum daily dose discrepancy caused by the interplay effect will be larger than 10%. This software was experimentally evaluated, and found to conservatively predict whether a given MLC sequence could give large daily dose discrepancies

A neurocomputational model of figure-ground discrimination and target tracking.

Science.gov (United States)

Sun, H; Liu, L; Guo, A

1999-01-01

A neurocomputational model is presented for figureground discrimination and target tracking. In the model, the elementary motion detectors of the correlation type, the computational modules of saccadic and smooth pursuit eye movement, an oscillatory neural-network motion perception module and a selective attention module are involved. It is shown that through the oscillatory amplitude and frequency encoding, and selective synchronization of phase oscillators, the figure and the ground can be successfully discriminated from each other. The receptive fields developed by hidden units of the networks were surprisingly similar to the actual receptive fields and columnar organization found in the primate visual cortex. It is suggested that equivalent mechanisms may exist in the primate visual cortex to discriminate figure-ground in both temporal and spatial domains.

Experimental investigation of a moving averaging algorithm for motion perpendicular to the leaf travel direction in dynamic MLC target tracking

Energy Technology Data Exchange (ETDEWEB)

Yoon, Jai-Woong; Sawant, Amit; Suh, Yelin; Cho, Byung-Chul; Suh, Tae-Suk; Keall, Paul [Department of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul, Korea 131-700 and Research Institute of Biomedical Engineering, Catholic University of Korea, Seoul, 131-700 (Korea, Republic of); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States) and Department of Radiation Oncology, Asan Medical Center, Seoul, 138-736 (Korea, Republic of); Department of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul, 131-700 and Research Institute of Biomedical Engineering, Catholic University of Korea, Seoul, 131-700 (Korea, Republic of); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States) and Radiation Physics Laboratory, Sydney Medical School, University of Sydney, 2006 (Australia)

2011-07-15

Purpose: In dynamic multileaf collimator (MLC) motion tracking with complex intensity-modulated radiation therapy (IMRT) fields, target motion perpendicular to the MLC leaf travel direction can cause beam holds, which increase beam delivery time by up to a factor of 4. As a means to balance delivery efficiency and accuracy, a moving average algorithm was incorporated into a dynamic MLC motion tracking system (i.e., moving average tracking) to account for target motion perpendicular to the MLC leaf travel direction. The experimental investigation of the moving average algorithm compared with real-time tracking and no compensation beam delivery is described. Methods: The properties of the moving average algorithm were measured and compared with those of real-time tracking (dynamic MLC motion tracking accounting for both target motion parallel and perpendicular to the leaf travel direction) and no compensation beam delivery. The algorithm was investigated using a synthetic motion trace with a baseline drift and four patient-measured 3D tumor motion traces representing regular and irregular motions with varying baseline drifts. Each motion trace was reproduced by a moving platform. The delivery efficiency, geometric accuracy, and dosimetric accuracy were evaluated for conformal, step-and-shoot IMRT, and dynamic sliding window IMRT treatment plans using the synthetic and patient motion traces. The dosimetric accuracy was quantified via a {gamma}-test with a 3%/3 mm criterion. Results: The delivery efficiency ranged from 89 to 100% for moving average tracking, 26%-100% for real-time tracking, and 100% (by definition) for no compensation. The root-mean-square geometric error ranged from 3.2 to 4.0 mm for moving average tracking, 0.7-1.1 mm for real-time tracking, and 3.7-7.2 mm for no compensation. The percentage of dosimetric points failing the {gamma}-test ranged from 4 to 30% for moving average tracking, 0%-23% for real-time tracking, and 10%-47% for no compensation

Experimental investigation of a moving averaging algorithm for motion perpendicular to the leaf travel direction in dynamic MLC target tracking.

Science.gov (United States)

Yoon, Jai-Woong; Sawant, Amit; Suh, Yelin; Cho, Byung-Chul; Suh, Tae-Suk; Keall, Paul

2011-07-01

In dynamic multileaf collimator (MLC) motion tracking with complex intensity-modulated radiation therapy (IMRT) fields, target motion perpendicular to the MLC leaf travel direction can cause beam holds, which increase beam delivery time by up to a factor of 4. As a means to balance delivery efficiency and accuracy, a moving average algorithm was incorporated into a dynamic MLC motion tracking system (i.e., moving average tracking) to account for target motion perpendicular to the MLC leaf travel direction. The experimental investigation of the moving average algorithm compared with real-time tracking and no compensation beam delivery is described. The properties of the moving average algorithm were measured and compared with those of real-time tracking (dynamic MLC motion tracking accounting for both target motion parallel and perpendicular to the leaf travel direction) and no compensation beam delivery. The algorithm was investigated using a synthetic motion trace with a baseline drift and four patient-measured 3D tumor motion traces representing regular and irregular motions with varying baseline drifts. Each motion trace was reproduced by a moving platform. The delivery efficiency, geometric accuracy, and dosimetric accuracy were evaluated for conformal, step-and-shoot IMRT, and dynamic sliding window IMRT treatment plans using the synthetic and patient motion traces. The dosimetric accuracy was quantified via a tgamma-test with a 3%/3 mm criterion. The delivery efficiency ranged from 89 to 100% for moving average tracking, 26%-100% for real-time tracking, and 100% (by definition) for no compensation. The root-mean-square geometric error ranged from 3.2 to 4.0 mm for moving average tracking, 0.7-1.1 mm for real-time tracking, and 3.7-7.2 mm for no compensation. The percentage of dosimetric points failing the gamma-test ranged from 4 to 30% for moving average tracking, 0%-23% for real-time tracking, and 10%-47% for no compensation. The delivery efficiency of

Detection of Moving Targets Based on Doppler Spectrum Analysis Technique for Passive Coherent Radar

Directory of Open Access Journals (Sweden)

Zhao Yao-dong

2013-06-01

Full Text Available A novel method of moving targets detection taking Doppler spectrum analysis technique for Passive Coherent Radar (PCR is provided. After dividing the receiving signals into segments as pulse series, it utilizes the technique of pulse compress and Doppler processing to detect and locate the targets. Based on the algorithm for Pulse-Doppler (PD radar, the equipollence between continuous and pulsed wave in match filtering is proved and details of this method are introduced. To compare it with the traditional method of Cross-Ambiguity Function (CAF calculation, the relationship and mathematical modes of them are analyzed, with some suggestions on parameters choosing. With little influence to the gain of targets, the method can greatly promote the processing efficiency. The validity of the proposed method is demonstrated by offline processing real collected data sets and simulation results.

Study on the Detection of Moving Target in the Mining Method Based on Hybrid Algorithm for Sports Video Analysis

Directory of Open Access Journals (Sweden)

Huang Tian

2014-10-01

Full Text Available Moving object detection and tracking is the computer vision and image processing is a hot research direction, based on the analysis of the moving target detection and tracking algorithm in common use, focus on the sports video target tracking non rigid body. In sports video, non rigid athletes often have physical deformation in the process of movement, and may be associated with the occurrence of moving target under cover. Media data is surging to fast search and query causes more difficulties in data. However, the majority of users want to be able to quickly from the multimedia data to extract the interested content and implicit knowledge (concepts, rules, rules, models and correlation, retrieval and query quickly to take advantage of them, but also can provide the decision support problem solving hierarchy. Based on the motion in sport video object as the object of study, conducts the system research from the theoretical level and technical framework and so on, from the layer by layer mining between low level motion features to high-level semantic motion video, not only provides support for users to find information quickly, but also can provide decision support for the user to solve the problem.

Infrared dim moving target tracking via sparsity-based discriminative classifier and convolutional network

Science.gov (United States)

Qian, Kun; Zhou, Huixin; Wang, Bingjian; Song, Shangzhen; Zhao, Dong

2017-11-01

Infrared dim and small target tracking is a great challenging task. The main challenge for target tracking is to account for appearance change of an object, which submerges in the cluttered background. An efficient appearance model that exploits both the global template and local representation over infrared image sequences is constructed for dim moving target tracking. A Sparsity-based Discriminative Classifier (SDC) and a Convolutional Network-based Generative Model (CNGM) are combined with a prior model. In the SDC model, a sparse representation-based algorithm is adopted to calculate the confidence value that assigns more weights to target templates than negative background templates. In the CNGM model, simple cell feature maps are obtained by calculating the convolution between target templates and fixed filters, which are extracted from the target region at the first frame. These maps measure similarities between each filter and local intensity patterns across the target template, therefore encoding its local structural information. Then, all the maps form a representation, preserving the inner geometric layout of a candidate template. Furthermore, the fixed target template set is processed via an efficient prior model. The same operation is applied to candidate templates in the CNGM model. The online update scheme not only accounts for appearance variations but also alleviates the migration problem. At last, collaborative confidence values of particles are utilized to generate particles' importance weights. Experiments on various infrared sequences have validated the tracking capability of the presented algorithm. Experimental results show that this algorithm runs in real-time and provides a higher accuracy than state of the art algorithms.

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.

Knowledge-Base Application to Ground Moving Target Detection

National Research Council Canada - National Science Library

Adve, R

2001-01-01

This report summarizes a multi-year in-house effort to apply knowledge-base control techniques and advanced Space-Time Adaptive Processing algorithms to improve detection performance and false alarm...

Moving Target Detection With Compact Laser Doppler Radar

Science.gov (United States)

Sepp, G.; Breining, A.; Eisfeld, W.; Knopp, R.; Lill, E.; Wagner, D.

1989-12-01

This paper describes an experimental integrated optronic system for detection and tracking of moving objects. The system is based on a CO2 waveguide laser Doppler ra-dar with homodyne receiver and galvanometer mirror beam scanner. A "hot spot" seeker consisting of a thermal imager with image processor transmits the coordinates of IR-emitting, i.e. potentially powered, objects to the laser radar scanner. The scanner addresses these "hot" locations operating in a large field-of-view (FOV) random ac-cess mode. Hot spots exhibiting a Doppler shifted laser signal are indicated in the thermal image by velocity-to-colour encoded markers. After switching to a small FOV scanning mode, the laser Doppler radar is used to track fast moving objects. Labora-tory and field experiments with moving objects including rotating discs, automobiles and missiles are described.

Robust Detection of Moving Human Target in Foliage-Penetration Environment Based on Hough Transform

Directory of Open Access Journals (Sweden)

P. Lei

2014-04-01

Full Text Available Attention has been focused on the robust moving human target detection in foliage-penetration environment, which presents a formidable task in a radar system because foliage is a rich scattering environment with complex multipath propagation and time-varying clutter. Generally, multiple-bounce returns and clutter are additionally superposed to direct-scatter echoes. They obscure true target echo and lead to poor visual quality time-range image, making target detection particular difficult. Consequently, an innovative approach is proposed to suppress clutter and mitigate multipath effects. In particular, a clutter suppression technique based on range alignment is firstly applied to suppress the time-varying clutter and the instable antenna coupling. Then entropy weighted coherent integration (EWCI algorithm is adopted to mitigate the multipath effects. In consequence, the proposed method effectively reduces the clutter and ghosting artifacts considerably. Based on the high visual quality image, the target trajectory is detected robustly and the radial velocity is estimated accurately with the Hough transform (HT. Real data used in the experimental results are provided to verify the proposed method.

Evaluating Moving Target Defense with PLADD

Energy Technology Data Exchange (ETDEWEB)

Jones, Stephen T. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Outkin, Alexander V. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Gearhart, Jared Lee [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hobbs, Jacob Aaron [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Siirola, John Daniel [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Phillips, Cynthia A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Verzi, Stephen Joseph [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Tauritz, Daniel [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Mulder, Samuel A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Naugle, Asmeret Bier [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

2015-09-15

This project evaluates the effectiveness of moving target defense (MTD) techniques using a new game we have designed, called PLADD, inspired by the game FlipIt [28]. PLADD extends FlipIt by incorporating what we believe are key MTD concepts. We have analyzed PLADD and proven the existence of a defender strategy that pushes a rational attacker out of the game, demonstrated how limited the strategies available to an attacker are in PLADD, and derived analytic expressions for the expected utility of the game’s players in multiple game variants. We have created an algorithm for finding a defender’s optimal PLADD strategy. We show that in the special case of achieving deterrence in PLADD, MTD is not always cost effective and that its optimal deployment may shift abruptly from not using MTD at all to using it as aggressively as possible. We believe our effort provides basic, fundamental insights into the use of MTD, but conclude that a truly practical analysis requires model selection and calibration based on real scenarios and empirical data. We propose several avenues for further inquiry, including (1) agents with adaptive capabilities more reflective of real world adversaries, (2) the presence of multiple, heterogeneous adversaries, (3) computational game theory-based approaches such as coevolution to allow scaling to the real world beyond the limitations of analytical analysis and classical game theory, (4) mapping the game to real-world scenarios, (5) taking player risk into account when designing a strategy (in addition to expected payoff), (6) improving our understanding of the dynamic nature of MTD-inspired games by using a martingale representation, defensive forecasting, and techniques from signal processing, and (7) using adversarial games to develop inherently resilient cyber systems.

An ML-Based Radial Velocity Estimation Algorithm for Moving Targets in Spaceborne High-Resolution and Wide-Swath SAR Systems

Directory of Open Access Journals (Sweden)

Tingting Jin

2017-04-01

Full Text Available Multichannel synthetic aperture radar (SAR is a significant breakthrough to the inherent limitation between high-resolution and wide-swath (HRWS compared with conventional SAR. Moving target indication (MTI is an important application of spaceborne HRWS SAR systems. In contrast to previous studies of SAR MTI, the HRWS SAR mainly faces the problem of under-sampled data of each channel, causing single-channel imaging and processing to be infeasible. In this study, the estimation of velocity is equivalent to the estimation of the cone angle according to their relationship. The maximum likelihood (ML based algorithm is proposed to estimate the radial velocity in the existence of Doppler ambiguities. After that, the signal reconstruction and compensation for the phase offset caused by radial velocity are processed for a moving target. Finally, the traditional imaging algorithm is applied to obtain a focused moving target image. Experiments are conducted to evaluate the accuracy and effectiveness of the estimator under different signal-to-noise ratios (SNR. Furthermore, the performance is analyzed with respect to the motion ship that experiences interference due to different distributions of sea clutter. The results verify that the proposed algorithm is accurate and efficient with low computational complexity. This paper aims at providing a solution to the velocity estimation problem in the future HRWS SAR systems with multiple receive channels.

Conceptualising the management of packaging within new product development:a grounded investigation in the UK fast moving consumer goods industry

OpenAIRE

Simms, Chris; Trott, Paul

2014-01-01

Purpose- The purpose of this study is to: (i) contribute to existing models of new product development (NPD), and provide new understanding of how a new product’s packaging is managed and integrated into the NPD process of fast moving consumer goods firms; and (ii) build on prior research suggesting that firms lack a pipeline of new packaging innovations by uncovering the factors that influence this pipeline issue. Design/methodology/approach- A grounded theory methodology was adopted. Resear...

Numerical methods for analysis of structure and ground vibration from moving loads

DEFF Research Database (Denmark)

Andersen, L.; Nielsen, S.R.K.; Krenk, Steen

2007-01-01

An overview of the main theoretical aspects of finite-element and boundary-element modelling of the response to moving loads is given. The moving loads represent sources of noise and vibration generated by moving vehicles, and the analysis describes the propagation of the disturbances generated i...

Low velocity target detection based on time-frequency image for high frequency ground wave radar

Institute of Scientific and Technical Information of China (English)

YAN Songhua; WU Shicai; WEN Biyang

2007-01-01

The Doppler spectral broadening resulted from non-stationary movement of target and radio-frequency interference will decrease the veracity of target detection by high frequency ground wave(HEGW)radar.By displaying the change of signal energy on two dimensional time-frequency images based on time-frequency analysis,a new mathematical morphology method to distinguish target from nonlinear time-frequency curves is presented.The analyzed results from the measured data verify that with this new method the target can be detected correctly from wide Doppler spectrum.

Calibrated infrared ground/air radiometric spectrometer

Science.gov (United States)

Silk, J. K.; Schildkraut, Elliot Robert; Bauldree, Russell S.; Goodrich, Shawn M.

1996-06-01

The calibrated infrared ground/air radiometric spectrometer (CIGARS) is a new high performance, multi-purpose, multi- platform Fourier transform spectrometer (FPS) sensor. It covers the waveband from 0.2 to 12 micrometer, has spectral resolution as fine as 0.3 cm-1, and records over 100 spectra per second. Two CIGARS units are being used for observations of target signatures in the air or on the ground from fixed or moving platforms, including high performance jet aircraft. In this paper we describe the characteristics and capabilities of the CIGARS sensor, which uses four interchangeable detector modules (Si, InGaAs, InSb, and HgCdTe) and two optics modules, with internal calibration. The data recording electronics support observations of transient events, even without precise information on the timing of the event. We present test and calibration data on the sensitivity, spectral resolution, stability, and spectral rate of CIGARS, and examples of in- flight observations of real targets. We also discuss plans for adapting CIGARS for imaging spectroscopy observations, with simultaneous spectral and spatial data, by replacing the existing detectors with a focal plane array (FPA).

Through-the-Wall Localization of a Moving Target by Two Independent Ultra Wideband (UWB Radar Systems

Directory of Open Access Journals (Sweden)

Jana Rovňáková

2013-09-01

Full Text Available In the case of through-the-wall localization of moving targets by ultra wideband (UWB radars, there are applications in which handheld sensors equipped only with one transmitting and two receiving antennas are applied. Sometimes, the radar using such a small antenna array is not able to localize the target with the required accuracy. With a view to improve through-the-wall target localization, cooperative positioning based on a fusion of data retrieved from two independent radar systems can be used. In this paper, the novel method of the cooperative localization referred to as joining intersections of the ellipses is introduced. This method is based on a geometrical interpretation of target localization where the target position is estimated using a properly created cluster of the ellipse intersections representing potential positions of the target. The performance of the proposed method is compared with the direct calculation method and two alternative methods of cooperative localization using data obtained by measurements with the M-sequence UWB radars. The direct calculation method is applied for the target localization by particular radar systems. As alternative methods of cooperative localization, the arithmetic average of the target coordinates estimated by two single independent UWB radars and the Taylor series method is considered.

Systematic analysis of neutron yields from thick targets bombarded by heavy ions and protons with moving source model

Energy Technology Data Exchange (ETDEWEB)

Kato, Takashi; Kurosawa, Tadahiro; Nakamura, Takashi E-mail: nakamura@cyric.tohoku.ac.jp

2002-03-21

A simple phenomenological analysis using the moving source model has been performed on the neutron energy spectra produced by bombarding thick targets with high energy heavy ions which have been systematically measured at the Heavy-Ion Medical Accelerator (HIMAC) facility (located in Chiba, Japan) of the National Institute of Radiological Sciences (NIRS). For the bombardment of both heavy ions and protons in the energy region of 100-500 MeV per nucleon, the moving source model incorporating the knock-on process could be generally successful in reproducing the measured neutron spectra within a factor of two margin of accuracy. This phenomenological analytical equation is expressed having several parameters as functions of atomic number Z{sub p}, mass number A{sub p}, energy per nucleon E{sub p} for projectile, and atomic number Z{sub T}, mass number A{sub T} for target. By inputting these basic data for projectile and target into this equation we can easily estimate the secondary neutron energy spectra at an emission angle of 0-90 deg. for bombardment with heavy ions and protons in the aforementioned energy region. This method will be quite useful to estimate the neutron source term in the neutron shielding design of high energy proton and heavy ion accelerators.

Low Complexity Moving Target Parameter Estimation for MIMO Radar using 2D-FFT

KAUST Repository

Jardak, Seifallah

2017-06-16

In multiple-input multiple-output radar, to localize a target and estimate its reflection coefficient, a given cost function is usually optimized over a grid of points. The performance of such algorithms is directly affected by the grid resolution. Increasing the number of grid points enhances the resolution of the estimator but also increases its computational complexity exponentially. In this work, two reduced complexity algorithms are derived based on Capon and amplitude and phase estimation (APES) to estimate the reflection coefficient, angular location and, Doppler shift of multiple moving targets. By exploiting the structure of the terms, the cost-function is brought into a form that allows us to apply the two-dimensional fast-Fourier-transform (2D-FFT) and reduce the computational complexity of estimation. Using low resolution 2D-FFT, the proposed algorithm identifies sub-optimal estimates and feeds them as initial points to the derived Newton gradient algorithm. In contrast to the grid-based search algorithms, the proposed algorithm can optimally estimate on- and off-the-grid targets in very low computational complexity. A new APES cost-function with better estimation performance is also discussed. Generalized expressions of the Cramér-Rao lower bound are derived to asses the performance of the proposed algorithm.

Low Complexity Moving Target Parameter Estimation for MIMO Radar using 2D-FFT

KAUST Repository

Jardak, Seifallah; Ahmed, Sajid; Alouini, Mohamed-Slim

2017-01-01

In multiple-input multiple-output radar, to localize a target and estimate its reflection coefficient, a given cost function is usually optimized over a grid of points. The performance of such algorithms is directly affected by the grid resolution. Increasing the number of grid points enhances the resolution of the estimator but also increases its computational complexity exponentially. In this work, two reduced complexity algorithms are derived based on Capon and amplitude and phase estimation (APES) to estimate the reflection coefficient, angular location and, Doppler shift of multiple moving targets. By exploiting the structure of the terms, the cost-function is brought into a form that allows us to apply the two-dimensional fast-Fourier-transform (2D-FFT) and reduce the computational complexity of estimation. Using low resolution 2D-FFT, the proposed algorithm identifies sub-optimal estimates and feeds them as initial points to the derived Newton gradient algorithm. In contrast to the grid-based search algorithms, the proposed algorithm can optimally estimate on- and off-the-grid targets in very low computational complexity. A new APES cost-function with better estimation performance is also discussed. Generalized expressions of the Cramér-Rao lower bound are derived to asses the performance of the proposed algorithm.

Location detection and tracking of moving targets by a 2D IR-UWB radar system.

Science.gov (United States)

Nguyen, Van-Han; Pyun, Jae-Young

2015-03-19

In indoor environments, the Global Positioning System (GPS) and long-range tracking radar systems are not optimal, because of signal propagation limitations in the indoor environment. In recent years, the use of ultra-wide band (UWB) technology has become a possible solution for object detection, localization and tracking in indoor environments, because of its high range resolution, compact size and low cost. This paper presents improved target detection and tracking techniques for moving objects with impulse-radio UWB (IR-UWB) radar in a short-range indoor area. This is achieved through signal-processing steps, such as clutter reduction, target detection, target localization and tracking. In this paper, we introduce a new combination consisting of our proposed signal-processing procedures. In the clutter-reduction step, a filtering method that uses a Kalman filter (KF) is proposed. Then, in the target detection step, a modification of the conventional CLEAN algorithm which is used to estimate the impulse response from observation region is applied for the advanced elimination of false alarms. Then, the output is fed into the target localization and tracking step, in which the target location and trajectory are determined and tracked by using unscented KF in two-dimensional coordinates. In each step, the proposed methods are compared to conventional methods to demonstrate the differences in performance. The experiments are carried out using actual IR-UWB radar under different scenarios. The results verify that the proposed methods can improve the probability and efficiency of target detection and tracking.

Student-Centered Coaching: The Moves

Science.gov (United States)

Sweeney, Diane; Harris, Leanna S.

2017-01-01

Student-centered coaching is a highly-effective, evidence-based coaching model that shifts the focus from "fixing" teachers to collaborating with them to design instruction that targets student outcomes. But what does this look like in practice? "Student-Centered Coaching: The Moves" shows you the day-to-day coaching moves that…

Location Detection and Tracking of Moving Targets by a 2D IR-UWB Radar System

Directory of Open Access Journals (Sweden)

Van-Han Nguyen

2015-03-01

Full Text Available In indoor environments, the Global Positioning System (GPS and long-range tracking radar systems are not optimal, because of signal propagation limitations in the indoor environment. In recent years, the use of ultra-wide band (UWB technology has become a possible solution for object detection, localization and tracking in indoor environments, because of its high range resolution, compact size and low cost. This paper presents improved target detection and tracking techniques for moving objects with impulse-radio UWB (IR-UWB radar in a short-range indoor area. This is achieved through signal-processing steps, such as clutter reduction, target detection, target localization and tracking. In this paper, we introduce a new combination consisting of our proposed signal-processing procedures. In the clutter-reduction step, a filtering method that uses a Kalman filter (KF is proposed. Then, in the target detection step, a modification of the conventional CLEAN algorithm which is used to estimate the impulse response from observation region is applied for the advanced elimination of false alarms. Then, the output is fed into the target localization and tracking step, in which the target location and trajectory are determined and tracked by using unscented KF in two-dimensional coordinates. In each step, the proposed methods are compared to conventional methods to demonstrate the differences in performance. The experiments are carried out using actual IR-UWB radar under different scenarios. The results verify that the proposed methods can improve the probability and efficiency of target detection and tracking.

Dosimetric evaluation of a moving tumor target in intensity-modulated radiation therapy (IMRT) for lung cancer patients

Science.gov (United States)

Kim, Sung Kyu; Kang, Min Kyu; Yea, Ji Woon; Oh, Se An

2013-07-01

Immobilization plays an important role in intensity-modulated radiation therapy (IMRT). The application of IMRT in lung cancer patients is very difficult due to the movement of the tumor target. Patient setup in radiation treatment demands high accuracy because IMRT employs a treatment size of a 1mm pixel unit. Hence, quality assurance of the dose delivered to patients must be at its highest. The radiation dose was evaluated for breathing rates of 9, 14, and 18 breaths per minute (bpm) for tumor targets moving up and down by 1.0 cm and 1.5 cm. The dose of the moving planned target volume (PTV) was measured by using a thermo-luminescent dosimeter (TLD) and Gafchromic™ EBT film. The measurement points were 1.0 cm away from the top, the bottom and the left and the right sides of the PTV center. The evaluated dose differences ranged from 94.2 to 103.8%, from 94.4 to 105.4%, and from 90.7 to 108.5% for 9, 14 and 18 bpm, respectively, for a tumor movement of 1.0 cm. The mean values of the doses were 101.4, 99.9, and 99.5% for 9, 14 and 18 bpm, respectively, for a tumor movement of 1.0 cm. Meanwhile, the evaluated dose differences ranged from 93.6 to 105.8%, from 95.9 to 111.5%, and from 96.2 to 111.7% for 9, 14 and 18 bpm, respectively, for a tumor movement of 1.5 cm. The mean values of the doses were 102.3, 103.4, and 103.1% for 9, 14 and 18 bpm, respectively, for a tumor movement of 1.5 cm. Therefore, we suggest that IMRT can be used in the treatment of lung cancer patients with vertical target movements within the range of 1.0 to 1.5 cm.

Useful variational principle for the scattering length for the target ground-state wave function imprecisely known

International Nuclear Information System (INIS)

Blau, R.; Rosenberg, L.; Spruch, L.

1977-01-01

A minimum principle for the calculation of the scattering length, applicable when the ground-state wave function of the target system is known precisely, has been available for some time. When, as is almost always the case, the target wave function is imprecisely known, a minimum principle is available but the simple minimum principle noted above is not applicable. Further, as recent calculations show, numerical instabilities usually arise which severely limit the utility of even an ordinary variational approach. The difficulty, which can be traced to the appearance of singularities in the variational construction, is here removed through the introduction of a minimum principle, not for the true scattering length, but for one associated with a closely connected problem. This guarantees that no instability difficulties can arise as the trial scattering wave function and the trial target wave function are improved. The calculations are little different from those required when the target ground-state wave function is known, and, in fact, the original version of the minimum principle is recovered as the trial target wave function becomes exact. A careful discussion is given of the types of problems to which the method can be applied. In particular, the effects of the Pauli principle, and the existence of a finite number of composite bound states, can be accounted for

Tumor trailing strategy for intensity-modulated radiation therapy of moving targets

International Nuclear Information System (INIS)

Trofimov, Alexei; Vrancic, Christian; Chan, Timothy C. Y.; Sharp, Gregory C.; Bortfeld, Thomas

2008-01-01

Internal organ motion during the course of radiation therapy of cancer affects the distribution of the delivered dose and, generally, reduces its conformality to the targeted volume. Previously proposed approaches aimed at mitigating the effect of internal motion in intensity-modulated radiation therapy (IMRT) included expansion of the target margins, motion-correlated delivery (e.g., respiratory gating, tumor tracking), and adaptive treatment plan optimization employing a probabilistic description of motion. We describe and test the tumor trailing strategy, which utilizes the synergy of motion-adaptive treatment planning and delivery methods. We regard the (rigid) target motion as a superposition of a relatively fast cyclic component (e.g., respiratory) and slow aperiodic trends (e.g., the drift of exhalation baseline). In the trailing approach, these two components of motion are decoupled and dealt with separately. Real-time motion monitoring is employed to identify the 'slow' shifts, which are then corrected by applying setup adjustments. The delivery does not track the target position exactly, but trails the systematic trend due to the delay between the time a shift occurs, is reliably detected, and, subsequently, corrected. The ''fast'' cyclic motion is accounted for with a robust motion-adaptive treatment planning, which allows for variability in motion parameters (e.g., mean and extrema of the tidal volume, variable period of respiration, and expiratory duration). Motion-surrogate data from gated IMRT treatments were used to provide probability distribution data for motion-adaptive planning and to test algorithms that identified systematic trends in the character of motion. Sample IMRT fields were delivered on a clinical linear accelerator to a programmable moving phantom. Dose measurements were performed with a commercial two-dimensional ion-chamber array. The results indicate that by reducing intrafractional motion variability, the trailing strategy

Satisfaction in motion: Subsequent search misses are more likely in moving search displays.

Science.gov (United States)

Stothart, Cary; Clement, Andrew; Brockmole, James R

2018-02-01

People often conduct visual searches in which multiple targets are possible (e.g., medical X-rays can contain multiple abnormalities). In this type of search, observers are more likely to miss a second target after having found a first one (a subsequent search miss). Recent evidence has suggested that this effect may be due to a depletion of cognitive resources from tracking the identities and locations of found targets. Given that tracking moving objects is resource-demanding, would finding a moving target further increase the chances of missing a subsequent one? To address this question, we had participants search for one or more targets hidden among distractors. Subsequent search misses were more likely when the targets and distractors moved throughout the display than when they remained stationary. However, when the found targets were highlighted in a unique color, subsequent search misses were no more likely in moving displays. Together, these results suggest that the effect of movement is likely due to the increased cognitive demands of tracking moving targets. Overall, our findings reveal that activities that involve searching for moving targets (e.g., driving) are more susceptible to subsequent search misses than are those that involve searching for stationary targets (e.g., baggage screening).

Seismic Target Classification Using a Wavelet Packet Manifold in Unattended Ground Sensors Systems

Directory of Open Access Journals (Sweden)

Enliang Song

2013-07-01

Full Text Available One of the most challenging problems in target classification is the extraction of a robust feature, which can effectively represent a specific type of targets. The use of seismic signals in unattended ground sensor (UGS systems makes this problem more complicated, because the seismic target signal is non-stationary, geology-dependent and with high-dimensional feature space. This paper proposes a new feature extraction algorithm, called wavelet packet manifold (WPM, by addressing the neighborhood preserving embedding (NPE algorithm of manifold learning on the wavelet packet node energy (WPNE of seismic signals. By combining non-stationary information and low-dimensional manifold information, WPM provides a more robust representation for seismic target classification. By using a K nearest neighbors classifier on the WPM signature, the algorithm of wavelet packet manifold classification (WPMC is proposed. Experimental results show that the proposed WPMC can not only reduce feature dimensionality, but also improve the classification accuracy up to 95.03%. Moreover, compared with state-of-the-art methods, WPMC is more suitable for UGS in terms of recognition ratio and computational complexity.

A Novel Method for Proximity Detection of Moving Targets Using a Large-Scale Planar Capacitive Sensor System

Directory of Open Access Journals (Sweden)

Yong Ye

2016-05-01

Full Text Available A novel method for proximity detection of moving targets (with high dielectric constants using a large-scale (the size of each sensor is 31 cm × 19 cm planar capacitive sensor system (PCSS is proposed. The capacitive variation with distance is derived, and a pair of electrodes in a planar capacitive sensor unit (PCSU with a spiral shape is found to have better performance on sensitivity distribution homogeneity and dynamic range than three other shapes (comb shape, rectangular shape, and circular shape. A driving excitation circuit with a Clapp oscillator is proposed, and a capacitance measuring circuit with sensitivity of 0.21 V p − p / pF is designed. The results of static experiments and dynamic experiments demonstrate that the voltage curves of static experiments are similar to those of dynamic experiments; therefore, the static data can be used to simulate the dynamic curves. The dynamic range of proximity detection for three projectiles is up to 60 cm, and the results of the following static experiments show that the PCSU with four neighboring units has the highest sensitivity (the sensitivities of other units are at least 4% lower; when the attack angle decreases, the intensity of sensor signal increases. This proposed method leads to the design of a feasible moving target detector with simple structure and low cost, which can be applied in the interception system.

Research on measurement method of optical camouflage effect of moving object

Science.gov (United States)

Wang, Juntang; Xu, Weidong; Qu, Yang; Cui, Guangzhen

2016-10-01

Camouflage effectiveness measurement as an important part of the camouflage technology, which testing and measuring the camouflage effect of the target and the performance of the camouflage equipment according to the tactical and technical requirements. The camouflage effectiveness measurement of current optical band is mainly aimed at the static target which could not objectively reflect the dynamic camouflage effect of the moving target. This paper synthetical used technology of dynamic object detection and camouflage effect detection, the digital camouflage of the moving object as the research object, the adaptive background update algorithm of Surendra was improved, a method of optical camouflage effect detection using Lab-color space in the detection of moving-object was presented. The binary image of moving object is extracted by this measurement technology, in the sequence diagram, the characteristic parameters such as the degree of dispersion, eccentricity, complexity and moment invariants are constructed to construct the feature vector space. The Euclidean distance of moving target which through digital camouflage was calculated, the results show that the average Euclidean distance of 375 frames was 189.45, which indicated that the degree of dispersion, eccentricity, complexity and moment invariants of the digital camouflage graphics has a great difference with the moving target which not spray digital camouflage. The measurement results showed that the camouflage effect was good. Meanwhile with the performance evaluation module, the correlation coefficient of the dynamic target image range 0.1275 from 0.0035, and presented some ups and down. Under the dynamic condition, the adaptability of target and background was reflected. In view of the existing infrared camouflage technology, the next step, we want to carry out the camouflage effect measurement technology of the moving target based on infrared band.

A moving experience !

CERN Document Server

2005-01-01

The Transport Service pulled out all the stops and, more specifically, its fleet of moving and lifting equipment for the Discovery Monday on 6 June - a truly moving experience for all the visitors who took part ! Visitors could play at being machine operator, twiddling the controls of a lift truck fitted with a jib to lift a dummy magnet into a wooden mock-up of a beam-line.They had to show even greater dexterity for this game of lucky dip...CERN-style.Those with a head for heights took to the skies 20 m above ground in a telescopic boom lift.Children were allowed to climb up into the operator's cabin - this is one of the cranes used to move the LHC magnets around. Warm thanks to all members of the Transport Service for their participation, especially B. Goicoechea, T. Ilkei, R. Bihery, S. Prodon, S. Pelletier, Y. Bernard, A.  Sallot, B. Pigeard, S. Guinchard, B. Bulot, J. Berrez, Y. Grandjean, A. Bouakkaz, M. Bois, F. Stach, T. Mazzarino and S. Fumey.

Terrestrial carbon storage dynamics: Chasing a moving target

Science.gov (United States)

Luo, Y.; Shi, Z.; Jiang, L.; Xia, J.; Wang, Y.; Kc, M.; Liang, J.; Lu, X.; Niu, S.; Ahlström, A.; Hararuk, O.; Hastings, A.; Hoffman, F. M.; Medlyn, B. E.; Rasmussen, M.; Smith, M. J.; Todd-Brown, K. E.; Wang, Y.

2015-12-01

Terrestrial ecosystems have been estimated to absorb roughly 30% of anthropogenic CO2 emissions. Past studies have identified myriad drivers of terrestrial carbon storage changes, such as fire, climate change, and land use changes. Those drivers influence the carbon storage change via diverse mechanisms, which have not been unified into a general theory so as to identify what control the direction and rate of terrestrial carbon storage dynamics. Here we propose a theoretical framework to quantitatively determine the response of terrestrial carbon storage to different exogenous drivers. With a combination of conceptual reasoning, mathematical analysis, and numeric experiments, we demonstrated that the maximal capacity of an ecosystem to store carbon is time-dependent and equals carbon input (i.e., net primary production, NPP) multiplying by residence time. The capacity is a moving target toward which carbon storage approaches (i.e., the direction of carbon storage change) but usually does not attain. The difference between the capacity and the carbon storage at a given time t is the unrealized carbon storage potential. The rate of the storage change is proportional to the magnitude of the unrealized potential. We also demonstrated that a parameter space of NPP, residence time, and carbon storage potential can well characterize carbon storage dynamics quantified at six sites ranging from tropical forests to tundra and simulated by two versions (carbon-only and coupled carbon-nitrogen) of the Australian Community Atmosphere-Biosphere Land Ecosystem (CABLE) Model under three climate change scenarios (CO2 rising only, climate warming only, and RCP8.5). Overall this study reveals the unified mechanism unerlying terrestrial carbon storage dynamics to guide transient traceability analysis of global land models and synthesis of empirical studies.

Is perception of self-motion speed a necessary condition for intercepting a moving target while walking?

Science.gov (United States)

Morice, Antoine H P; Wallet, Grégory; Montagne, Gilles

2014-04-30

While it has been shown that the Global Optic Flow Rate (GOFR) is used in the control of self-motion speed, this study examined its relevance in the control of interceptive actions while walking. We asked participants to intercept approaching targets by adjusting their walking speed in a virtual environment, and predicted that the influence of the GOFR depended on their interception strategy. Indeed, unlike the Constant Bearing Angle (CBA), the Modified Required Velocity (MRV) strategy relies on the perception of self-displacement speed. On the other hand, the CBA strategy involves specific speed adjustments depending on the curvature of the target's trajectory, whereas the MRV does not. We hypothesized that one strategy is selected among the two depending on the informational content of the environment. We thus manipulated the curvature and display of the target's trajectory, and the relationship between physical walking speed and the GOFR (through eye height manipulations). Our results showed that when the target trajectory was not displayed, walking speed profiles were affected by curvature manipulations. Otherwise, walking speed profiles were less affected by curvature manipulations and were affected by the GOFR manipulations. Taken together, these results show that the use of the GOFR for intercepting a moving target while walking depends on the informational content of the environment. Finally we discuss the complementary roles of these two perceptual-motor strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Efficient moving target analysis for inverse synthetic aperture radar images via joint speeded-up robust features and regular moment

Science.gov (United States)

Yang, Hongxin; Su, Fulin

2018-01-01

We propose a moving target analysis algorithm using speeded-up robust features (SURF) and regular moment in inverse synthetic aperture radar (ISAR) image sequences. In our study, we first extract interest points from ISAR image sequences by SURF. Different from traditional feature point extraction methods, SURF-based feature points are invariant to scattering intensity, target rotation, and image size. Then, we employ a bilateral feature registering model to match these feature points. The feature registering scheme can not only search the isotropic feature points to link the image sequences but also reduce the error matching pairs. After that, the target centroid is detected by regular moment. Consequently, a cost function based on correlation coefficient is adopted to analyze the motion information. Experimental results based on simulated and real data validate the effectiveness and practicability of the proposed method.

SAR image dataset of military ground targets with multiple poses for ATR

Science.gov (United States)

Belloni, Carole; Balleri, Alessio; Aouf, Nabil; Merlet, Thomas; Le Caillec, Jean-Marc

2017-10-01

Automatic Target Recognition (ATR) is the task of automatically detecting and classifying targets. Recognition using Synthetic Aperture Radar (SAR) images is interesting because SAR images can be acquired at night and under any weather conditions, whereas optical sensors operating in the visible band do not have this capability. Existing SAR ATR algorithms have mostly been evaluated using the MSTAR dataset.1 The problem with the MSTAR is that some of the proposed ATR methods have shown good classification performance even when targets were hidden,2 suggesting the presence of a bias in the dataset. Evaluations of SAR ATR techniques are currently challenging due to the lack of publicly available data in the SAR domain. In this paper, we present a high resolution SAR dataset consisting of images of a set of ground military target models taken at various aspect angles, The dataset can be used for a fair evaluation and comparison of SAR ATR algorithms. We applied the Inverse Synthetic Aperture Radar (ISAR) technique to echoes from targets rotating on a turntable and illuminated with a stepped frequency waveform. The targets in the database consist of four variants of two 1.7m-long models of T-64 and T-72 tanks. The gun, the turret position and the depression angle are varied to form 26 different sequences of images. The emitted signal spanned the frequency range from 13 GHz to 18 GHz to achieve a bandwidth of 5 GHz sampled with 4001 frequency points. The resolution obtained with respect to the size of the model targets is comparable to typical values obtained using SAR airborne systems. Single polarized images (Horizontal-Horizontal) are generated using the backprojection algorithm.3 A total of 1480 images are produced using a 20° integration angle. The images in the dataset are organized in a suggested training and testing set to facilitate a standard evaluation of SAR ATR algorithms.

Transonic and supersonic ground effect aerodynamics

Science.gov (United States)

Doig, G.

2014-08-01

A review of recent and historical work in the field of transonic and supersonic ground effect aerodynamics has been conducted, focussing on applied research on wings and aircraft, present and future ground transportation, projectiles, rocket sleds and other related bodies which travel in close ground proximity in the compressible regime. Methods for ground testing are described and evaluated, noting that wind tunnel testing is best performed with a symmetry model in the absence of a moving ground; sled or rail testing is ultimately preferable, though considerably more expensive. Findings are reported on shock-related ground influence on aerodynamic forces and moments in and accelerating through the transonic regime - where force reversals and the early onset of local supersonic flow is prevalent - as well as more predictable behaviours in fully supersonic to hypersonic ground effect flows.

Figure-ground representation and its decay in primary visual cortex.

Science.gov (United States)

Strother, Lars; Lavell, Cheryl; Vilis, Tutis

2012-04-01

We used fMRI to study figure-ground representation and its decay in primary visual cortex (V1). Human observers viewed a motion-defined figure that gradually became camouflaged by a cluttered background after it stopped moving. V1 showed positive fMRI responses corresponding to the moving figure and negative fMRI responses corresponding to the static background. This positive-negative delineation of V1 "figure" and "background" fMRI responses defined a retinotopically organized figure-ground representation that persisted after the figure stopped moving but eventually decayed. The temporal dynamics of V1 "figure" and "background" fMRI responses differed substantially. Positive "figure" responses continued to increase for several seconds after the figure stopped moving and remained elevated after the figure had disappeared. We propose that the sustained positive V1 "figure" fMRI responses reflected both persistent figure-ground representation and sustained attention to the location of the figure after its disappearance, as did subjects' reports of persistence. The decreasing "background" fMRI responses were relatively shorter-lived and less biased by spatial attention. Our results show that the transition from a vivid figure-ground percept to its disappearance corresponds to the concurrent decay of figure enhancement and background suppression in V1, both of which play a role in form-based perceptual memory.

The Moving Group Targets of the SEEDS High-contrast Imaging Survey of Exoplanets and Disks: Results and Observations from the First Three Years

NARCIS (Netherlands)

Brandt, T.D.; et al., [Unknown; Thalmann, C.

2014-01-01

We present results from the first three years of observations of moving group (MG) targets in the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) high-contrast imaging survey of exoplanets and disks using the Subaru telescope. We achieve typical contrasts of ~105 at 1'' and ~106

Mechanisms in wing-in-ground effect aerodynamics

Science.gov (United States)

Jones, Marvin Alan

An aircraft in low-level flight experiences a large increase in lift and a marked reduction in drag, compared with flight at altitude. This phenomenon is termed the 'wing-in-ground' effect. In these circumstances a region of high pressure is created beneath the aerofoil, and a pressure difference is set up between its upper and lower surfaces. A pressure difference is not permitted at the trailing edge and therefore a mechanism must exist which allows the pressures above and below to adjust themselves to produce a continuous pressure field in the wake. It is the study of this mechanism and its role in the aerodynamics of low-level flight that forms the basis of our investigation. We begin in Chapter 2 by considering the flow past a thin aero-foil moving at moderate distances from the ground, the typical ground clearance a being of order unity. The aforementioned mechanism is introduced and described in detail in the context of this inviscid problem. Chapter 3 considers the same flow for large and small ground clearances and in the later case shows that the flow solution beneath the aerofoil takes on a particularly simple form. In this case the lift is shown to increase as a-1. In Chapter 4 we focus on the flow past the trailing edge of an aerofoil moving even nearer the ground, with the ground just outside the boundary layer. We show that in this case our asymptotic theory for small a is consistent with a 'triple-deck' approach to the problem which incorporates ground effects via a new pressure-displacement law. The triple-deck ground-interference problem is stated and solved. In Chapter 5 we investigate the case where the aerofoil is so near the ground that the ground is inside the boundary layer. Here the moving ground interacts with the aerofoil in a fully viscous way and the non-linear boundary layer equations hold along the entire length of the aerofoil. Again a pressure difference at the trailing edge is not permitted and this produces upstream adjustment

Reduced complexity FFT-based DOA and DOD estimation for moving target in bistatic MIMO radar

KAUST Repository

Ali, Hussain

2016-06-24

In this paper, we consider a bistatic multiple-input multiple-output (MIMO) radar. We propose a reduced complexity algorithm to estimate the direction-of-arrival (DOA) and direction-of-departure (DOD) for moving target. We show that the calculation of parameter estimation can be expressed in terms of one-dimensional fast-Fourier-transforms which drastically reduces the complexity of the optimization algorithm. The performance of the proposed algorithm is compared with the two-dimension multiple signal classification (2D-MUSIC) and reduced-dimension MUSIC (RD-MUSIC) algorithms. It is shown by simulations, our proposed algorithm has better estimation performance and lower computational complexity compared to the 2D-MUSIC and RD-MUSIC algorithms. Moreover, simulation results also show that the proposed algorithm achieves the Cramer-Rao lower bound. © 2016 IEEE.

Enhanced spatial resolution on figures versus grounds.

Science.gov (United States)

Hecht, Lauren N; Cosman, Joshua D; Vecera, Shaun P

2016-07-01

Much is known about the cues that determine figure-ground assignment, but less is known about the consequences of figure-ground assignment on later visual processing. Previous work has demonstrated that regions assigned figural status are subjectively more shape-like and salient than background regions. The increase in subjective salience of figural regions could be caused by a number of processes, one of which may be enhanced perceptual processing (e.g., an enhanced neural representation) of figures relative to grounds. We explored this hypothesis by having observers perform a perceptually demanding spatial resolution task in which targets appeared on either figure or ground regions. To rule out a purely attentional account of figural salience, observers discriminated targets on the basis of a region's color (red or green), which was equally likely to define the figure or the ground. The results of our experiments showed that targets appearing on figures were discriminated more accurately than those appearing in ground regions. In addition, targets appearing on figures were discriminated better than those presented in regions considered figurally neutral, but targets appearing within ground regions were discriminated more poorly than those appearing in figurally neutral regions. Taken together, our findings suggest that when two regions share a contour, regions assigned as figure are perceptually enhanced, whereas regions assigned as ground are perceptually suppressed.

Enhanced spatial resolution on figures versus grounds

Science.gov (United States)

Hecht, Lauren N.; Cosman, Joshua D.; Vecera, Shaun P.

2016-01-01

Much is known about the cues that determine figure-ground assignment, but less is known about the consequences of figure-ground assignment on later visual processing. Previous work has demonstrated that regions assigned figural status are subjectively more shape-like and salient than background regions. The increase in subjective salience of figural regions could be caused by a number of processes, one of which may be enhanced perceptual processing (e.g., an enhanced neural representation) of figures relative to grounds. We explored this hypothesis by having observers perform a perceptually demanding spatial resolution task in which targets appeared either on figure or ground regions. To rule out a purely attentional account of figural salience, observers discriminated targets on the basis of a region’s color (red or green), which was equally likely to define the figure or the ground. The results of our experiments show that targets appearing on figures were discriminated more accurately than those appearing in ground regions. In addition, targets appearing on figures were discriminated better than those presented in regions considered figurally neutral, but targets appearing within ground regions were discriminated more poorly than those appearing in figurally neutral regions. Taken together, our findings suggest that when two regions share a contour, regions assigned as figure are perceptually enhanced, whereas regions assigned as grounds are perceptually suppressed. PMID:27048441

Laser Guidestar Satellite for Ground-based Adaptive Optics Imaging of Geosynchronous Satellites and Astronomical Targets

Science.gov (United States)

Marlow, W. A.; Cahoy, K.; Males, J.; Carlton, A.; Yoon, H.

2015-12-01

Real-time observation and monitoring of geostationary (GEO) satellites with ground-based imaging systems would be an attractive alternative to fielding high cost, long lead, space-based imagers, but ground-based observations are inherently limited by atmospheric turbulence. Adaptive optics (AO) systems are used to help ground telescopes achieve diffraction-limited seeing. AO systems have historically relied on the use of bright natural guide stars or laser guide stars projected on a layer of the upper atmosphere by ground laser systems. There are several challenges with this approach such as the sidereal motion of GEO objects relative to natural guide stars and limitations of ground-based laser guide stars; they cannot be used to correct tip-tilt, they are not point sources, and have finite angular sizes when detected at the receiver. There is a difference between the wavefront error measured using the guide star compared with the target due to cone effect, which also makes it difficult to use a distributed aperture system with a larger baseline to improve resolution. Inspired by previous concepts proposed by A.H. Greenaway, we present using a space-based laser guide starprojected from a satellite orbiting the Earth. We show that a nanosatellite-based guide star system meets the needs for imaging GEO objects using a low power laser even from 36,000 km altitude. Satellite guide star (SGS) systemswould be well above atmospheric turbulence and could provide a small angular size reference source. CubeSatsoffer inexpensive, frequent access to space at a fraction of the cost of traditional systems, and are now being deployed to geostationary orbits and on interplanetary trajectories. The fundamental CubeSat bus unit of 10 cm cubed can be combined in multiple units and offers a common form factor allowing for easy integration as secondary payloads on traditional launches and rapid testing of new technologies on-orbit. We describe a 6U CubeSat SGS measuring 10 cm x 20 cm x

Wake Shield Target Protection

International Nuclear Information System (INIS)

Valmianski, Emanuil I.; Petzoldt, Ronald W.; Alexander, Neil B.

2003-01-01

The heat flux from both gas convection and chamber radiation on a direct drive target must be limited to avoid target damage from excessive D-T temperature increase. One of the possibilities of protecting the target is a wake shield flying in front of the target. A shield will also reduce drag force on the target, thereby facilitating target tracking and position prediction. A Direct Simulation Monte Carlo (DSMC) code was used to calculate convection heat loads as boundary conditions input into ANSYS thermal calculations. These were used for studying the quality of target protection depending on various shapes of shields, target-shield distance, and protective properties of the shield moving relative to the target. The results show that the shield can reduce the convective heat flux by a factor of 2 to 5 depending on pressure, temperature, and velocity. The protective effect of a shield moving relative to the target is greater than the protective properties of a fixed shield. However, the protective effect of a shield moving under the drag force is not sufficient for bringing the heat load on the target down to the necessary limit. Some other ways of diminishing heat flux using a protective shield are discussed

Nonholonomic feedback control among moving obstacles

Science.gov (United States)

Armstrong, Stephen Gregory

A feedback controller is developed for navigating a nonholonomic vehicle in an area with multiple stationary and possibly moving obstacles. Among other applications the developed algorithms can be used for automatic parking of a passenger car in a parking lot with complex configuration or a ground robot in cluttered environment. Several approaches are explored which combine nonholonomic systems control based on sliding modes and potential field methods.

Robust Ground Target Detection by SAR and IR Sensor Fusion Using Adaboost-Based Feature Selection

Science.gov (United States)

Kim, Sungho; Song, Woo-Jin; Kim, So-Hyun

2016-01-01

Long-range ground targets are difficult to detect in a noisy cluttered environment using either synthetic aperture radar (SAR) images or infrared (IR) images. SAR-based detectors can provide a high detection rate with a high false alarm rate to background scatter noise. IR-based approaches can detect hot targets but are affected strongly by the weather conditions. This paper proposes a novel target detection method by decision-level SAR and IR fusion using an Adaboost-based machine learning scheme to achieve a high detection rate and low false alarm rate. The proposed method consists of individual detection, registration, and fusion architecture. This paper presents a single framework of a SAR and IR target detection method using modified Boolean map visual theory (modBMVT) and feature-selection based fusion. Previous methods applied different algorithms to detect SAR and IR targets because of the different physical image characteristics. One method that is optimized for IR target detection produces unsuccessful results in SAR target detection. This study examined the image characteristics and proposed a unified SAR and IR target detection method by inserting a median local average filter (MLAF, pre-filter) and an asymmetric morphological closing filter (AMCF, post-filter) into the BMVT. The original BMVT was optimized to detect small infrared targets. The proposed modBMVT can remove the thermal and scatter noise by the MLAF and detect extended targets by attaching the AMCF after the BMVT. Heterogeneous SAR and IR images were registered automatically using the proposed RANdom SAmple Region Consensus (RANSARC)-based homography optimization after a brute-force correspondence search using the detected target centers and regions. The final targets were detected by feature-selection based sensor fusion using Adaboost. The proposed method showed good SAR and IR target detection performance through feature selection-based decision fusion on a synthetic database generated

Robust Ground Target Detection by SAR and IR Sensor Fusion Using Adaboost-Based Feature Selection

Directory of Open Access Journals (Sweden)

Sungho Kim

2016-07-01

Full Text Available Long-range ground targets are difficult to detect in a noisy cluttered environment using either synthetic aperture radar (SAR images or infrared (IR images. SAR-based detectors can provide a high detection rate with a high false alarm rate to background scatter noise. IR-based approaches can detect hot targets but are affected strongly by the weather conditions. This paper proposes a novel target detection method by decision-level SAR and IR fusion using an Adaboost-based machine learning scheme to achieve a high detection rate and low false alarm rate. The proposed method consists of individual detection, registration, and fusion architecture. This paper presents a single framework of a SAR and IR target detection method using modified Boolean map visual theory (modBMVT and feature-selection based fusion. Previous methods applied different algorithms to detect SAR and IR targets because of the different physical image characteristics. One method that is optimized for IR target detection produces unsuccessful results in SAR target detection. This study examined the image characteristics and proposed a unified SAR and IR target detection method by inserting a median local average filter (MLAF, pre-filter and an asymmetric morphological closing filter (AMCF, post-filter into the BMVT. The original BMVT was optimized to detect small infrared targets. The proposed modBMVT can remove the thermal and scatter noise by the MLAF and detect extended targets by attaching the AMCF after the BMVT. Heterogeneous SAR and IR images were registered automatically using the proposed RANdom SAmple Region Consensus (RANSARC-based homography optimization after a brute-force correspondence search using the detected target centers and regions. The final targets were detected by feature-selection based sensor fusion using Adaboost. The proposed method showed good SAR and IR target detection performance through feature selection-based decision fusion on a synthetic

Convexities move because they contain matter.

Science.gov (United States)

Barenholtz, Elan

2010-09-22

Figure-ground assignment to a contour is a fundamental stage in visual processing. The current paper introduces a novel, highly general dynamic cue to figure-ground assignment: "Convex Motion." Across six experiments, subjects showed a strong preference to assign figure and ground to a dynamically deforming contour such that the moving contour segment was convex rather than concave. Experiments 1 and 2 established the preference across two different kinds of deformational motion. Additional experiments determined that this preference was not due to fixation (Experiment 3) or attentional mechanisms (Experiment 4). Experiment 5 found a similar, but reduced bias for rigid-as opposed to deformational-motion, and Experiment 6 demonstrated that the phenomenon depends on the global motion of the effected contour. An explanation of this phenomenon is presented on the basis of typical natural deformational motion, which tends to involve convex contour projections that contain regions consisting of physical "matter," as opposed to concave contour indentations that contain empty space. These results highlight the fundamental relationship between figure and ground, perceived shape, and the inferred physical properties of an object.

An autonomous robot inspired by insect neurophysiology pursues moving features in natural environments

Science.gov (United States)

Bagheri, Zahra M.; Cazzolato, Benjamin S.; Grainger, Steven; O'Carroll, David C.; Wiederman, Steven D.

2017-08-01

Objective. Many computer vision and robotic applications require the implementation of robust and efficient target-tracking algorithms on a moving platform. However, deployment of a real-time system is challenging, even with the computational power of modern hardware. Lightweight and low-powered flying insects, such as dragonflies, track prey or conspecifics within cluttered natural environments, illustrating an efficient biological solution to the target-tracking problem. Approach. We used our recent recordings from ‘small target motion detector’ neurons in the dragonfly brain to inspire the development of a closed-loop target detection and tracking algorithm. This model exploits facilitation, a slow build-up of response to targets which move along long, continuous trajectories, as seen in our electrophysiological data. To test performance in real-world conditions, we implemented this model on a robotic platform that uses active pursuit strategies based on insect behaviour. Main results. Our robot performs robustly in closed-loop pursuit of targets, despite a range of challenging conditions used in our experiments; low contrast targets, heavily cluttered environments and the presence of distracters. We show that the facilitation stage boosts responses to targets moving along continuous trajectories, improving contrast sensitivity and detection of small moving targets against textured backgrounds. Moreover, the temporal properties of facilitation play a useful role in handling vibration of the robotic platform. We also show that the adoption of feed-forward models which predict the sensory consequences of self-movement can significantly improve target detection during saccadic movements. Significance. Our results provide insight into the neuronal mechanisms that underlie biological target detection and selection (from a moving platform), as well as highlight the effectiveness of our bio-inspired algorithm in an artificial visual system.

A study on repainting strategies for treating moderately moving targets with proton pencil beam scanning at the new Gantry 2 at PSI

International Nuclear Information System (INIS)

Zenklusen, S M; Pedroni, E; Meer, D

2010-01-01

Treating moving targets using a scanning gantry for proton therapy is a promising but very challenging, not yet clinically demonstrated treatment modality. The interference of organ motion with the sequence of the beam delivery produces uncontrolled dose inhomogeneities within the target. One promising approach to overcome this difficulty is to increase the speed of scanning in order to apply the dose repeatedly (so-called repainting). To obtain sufficiently high scanning speeds a new, technologically improved gantry-Gantry 2-has been designed and is currently under construction at PSI. As there are many possible repainting strategies, the way repainting will be implemented on Gantry 2 will depend on the result of a careful analysis of the various treatment delivery strategies available. To achieve this aim, and prior to the start of experimental work with Gantry 2, simulations of dose distribution errors due to organ motion under various beam delivery strategies were investigated. The effects of motion on the dose distribution were studied for moderate motion amplitudes (5 mm) for spherical target volumes in a homogeneous medium and with homogeneous dose. In total over 200 000 dose distributions have been simulated and analyzed and selected results are discussed. From the obtained results we are confident to be able to treat moderately moving targets on Gantry 2 using repainted pencil-beam spot scanning. Continuous line scanning seems to be the most elegant solution; it provides higher repainting rates and produces superior results but is probably more difficult to realize. For larger motion amplitudes, continuous line scanning still shows good results, but we plan anyways to use a gating system for these cases, not only to reduce the inhomogeneity within the target volume but also to reduce safety margins.

The registration of non-cooperative moving targets laser point cloud in different view point

Science.gov (United States)

Wang, Shuai; Sun, Huayan; Guo, Huichao

2018-01-01

Non-cooperative moving target multi-view cloud registration is the key technology of 3D reconstruction of laser threedimension imaging. The main problem is that the density changes greatly and noise exists under different acquisition conditions of point cloud. In this paper, firstly, the feature descriptor is used to find the most similar point cloud, and then based on the registration algorithm of region segmentation, the geometric structure of the point is extracted by the geometric similarity between point and point, The point cloud is divided into regions based on spectral clustering, feature descriptors are created for each region, searching to find the most similar regions in the most similar point of view cloud, and then aligning the pair of point clouds by aligning their minimum bounding boxes. Repeat the above steps again until registration of all point clouds is completed. Experiments show that this method is insensitive to the density of point clouds and performs well on the noise of laser three-dimension imaging.

Moving a House by Moved Participants

DEFF Research Database (Denmark)

Axel, Erik

himself in controlling every detail of the shape of the concrete slaps. He pushed all the other participants of the meetings, asking for details, information, the change of drawings etc. He explained the technical issues he was pursuing, was prepared for problems at the meetings, was well informed, always......? The participant observer believed it was a matter of changing coordinates, but the engineers immediately saw it was an issue of pipes in the ground, could they be moved and still function as planned? To decide the possibility of this suggestion the engineer was given the task of investigating the consequences...... they saw him as a bit pushy. On the other hand they understood why he was so since his firm would be fined if the concrete slabs did not meet specifications. The case will be the basis for a discussion of double motivation of the engineer, his evident interest in his professional work, and the wish...

A Novel Detection Method for Underwater Moving Targets by Measuring Their ELF Emissions with Inductive Sensors

Directory of Open Access Journals (Sweden)

Jinhong Wang

2017-07-01

Full Text Available In this article, we propose a novel detection method for underwater moving targets by detecting their extremely low frequency (ELF emissions with inductive sensors. The ELF field source of the targets is modeled by a horizontal electric dipole at distances more than several times of the targets’ length. The formulas for the fields produced in air are derived with a three-layer model (air, seawater and seafloor and are evaluated with a complementary numerical integration technique. A proof of concept measurement is presented. The ELF emissions from a surface ship were detected by inductive electronic and magnetic sensors as the ship was leaving a harbor. ELF signals are of substantial strength and have typical characteristic of harmonic line spectrum, and the fundamental frequency has a direct relationship with the ship’s speed. Due to the high sensitivity and low noise level of our sensors, it is capable of resolving weak ELF signals at long distance. In our experiment, a detection distance of 1300 m from the surface ship above the sea surface was realized, which shows that this method would be an appealing complement to the usual acoustic detection and magnetic anomaly detection capability.

Section 10: Ground Water - Waste Characteristics & Targets

Science.gov (United States)

HRS Training. The waste characteristics factor category in the ground water pathway is made up of two components: the toxicity/mobility of the most hazardous substance associated with the site and the hazardous waste quantity at the site.

Competition-strength-dependent ground suppression in figure-ground perception.

Science.gov (United States)

Salvagio, Elizabeth; Cacciamani, Laura; Peterson, Mary A

2012-07-01

Figure-ground segregation is modeled as inhibitory competition between objects that might be perceived on opposite sides of borders. The winner is the figure; the loser is suppressed, and its location is perceived as shapeless ground. Evidence of ground suppression would support inhibitory competition models and would contribute to explaining why grounds are shapeless near borders shared with figures, yet such evidence is scarce. We manipulated whether competition from potential objects on the ground side of figures was high (i.e., portions of familiar objects were potentially present there) or low (novel objects were potentially present). We predicted that greater competition would produce more ground suppression. The results of two experiments in which suppression was assessed via judgments of the orientation of target bars confirmed this prediction; a third experiment showed that ground suppression is short-lived. Our findings support inhibitory competition models of figure assignment, in particular, and models of visual perception entailing feedback, in general.

Novel Method of Unambiguous Moving Target Detection in Pulse-Doppler Radar with Random Pulse Repetition Interval

Directory of Open Access Journals (Sweden)

Liu Zhen

2012-03-01

Full Text Available Blind zones and ambiguities in range and velocity measurement are two important issues in traditional pulse-Doppler radar. By generating random deviations with respect to a mean Pulse Repetition Interval (PRI, this paper proposes a novel algorithm of Moving Target Detection (MTD based on the Compressed Sensing (CS theory, in which the random deviations of the PRIare converted to the Restricted Isometry Property (RIP of the observing matrix. The ambiguities of range and velocity are eliminated by designing the signal parameters. The simulation results demonstrate that this scheme has high performance of detection, and there is no ambiguity and blind zones as well. It can also shorten the coherent processing interval compared to traditional staggered PRI mode because only one pulse train is needed instead of several trains.

Tracking a convoy of multiple targets using acoustic sensor data

Science.gov (United States)

Damarla, T. R.

2003-08-01

In this paper we present an algorithm to track a convoy of several targets in a scene using acoustic sensor array data. The tracking algorithm is based on template of the direction of arrival (DOA) angles for the leading target. Often the first target is the closest target to the sensor array and hence the loudest with good signal to noise ratio. Several steps were used to generate a template of the DOA angle for the leading target, namely, (a) the angle at the present instant should be close to the angle at the previous instant and (b) the angle at the present instant should be within error bounds of the predicted value based on the previous values. Once the template of the DOA angles of the leading target is developed, it is used to predict the DOA angle tracks of the remaining targets. In order to generate the tracks for the remaining targets, a track is established if the angles correspond to the initial track values of the first target. Second the time delay between the first track and the remaining tracks are estimated at the highest correlation points between the first track and the remaining tracks. As the vehicles move at different speeds the tracks either compress or expand depending on whether a target is moving fast or slow compared to the first target. The expansion and compression ratios are estimated and used to estimate the predicted DOA angle values of the remaining targets. Based on these predicted DOA angles of the remaining targets the DOA angles obtained from the MVDR or Incoherent MUSIC will be appropriately assigned to proper tracks. Several other rules were developed to avoid mixing the tracks. The algorithm is tested on data collected at Aberdeen Proving Ground with a convoy of 3, 4 and 5 vehicles. Some of the vehicles are tracked and some are wheeled vehicles. The tracking algorithm results are found to be good. The results will be presented at the conference and in the paper.

Dynamical scene analysis with a moving camera: mobile targets detection system

International Nuclear Information System (INIS)

Hennebert, Christine

1996-01-01

This thesis work deals with the detection of moving objects in monocular image sequences acquired with a mobile camera. We propose a method able to detect small moving objects in visible or infrared images of real outdoor scenes. In order to detect objects of very low apparent motion, we consider an analysis on a large temporal interval. We have chosen to compensate for the dominant motion due to the camera displacement for several consecutive images in order to form a sub-sequence of images for which the camera seems virtually static. We have also developed a new approach allowing to extract the different layers of a real scene in order to deal with cases where the 2D motion due to the camera displacement cannot be globally compensated for. To this end, we use a hierarchical model with two levels: the local merging step and the global merging one. Then, an appropriate temporal filtering is applied to registered image sub-sequence to enhance signals corresponding to moving objects. The detection issue is stated as a labeling problem within a statistical regularization based on Markov Random Fields. Our method has been validated on numerous real image sequences depicting complex outdoor scenes. Finally, the feasibility of an integrated circuit for mobile object detection has been proved. This circuit could lead to an ASIC creation. (author) [fr

The Confined Hydrogen Atom with a Moving Nucleus

Science.gov (United States)

Fernandez, Francisco M.

2010-01-01

We study the hydrogen atom confined to a spherical box with impenetrable walls but, unlike earlier pedagogical articles on the subject, we assume that the nucleus also moves. We obtain the ground-state energy approximately by means of first-order perturbation theory and show that it is greater than that for the case in which the nucleus is clamped…

Running the figure to the ground: figure-ground segmentation during visual search.

Science.gov (United States)

Ralph, Brandon C W; Seli, Paul; Cheng, Vivian O Y; Solman, Grayden J F; Smilek, Daniel

2014-04-01

We examined how figure-ground segmentation occurs across multiple regions of a visual array during a visual search task. Stimuli consisted of arrays of black-and-white figure-ground images in which roughly half of each image depicted a meaningful object, whereas the other half constituted a less meaningful shape. The colours of the meaningful regions of the targets and distractors were either the same (congruent) or different (incongruent). We found that incongruent targets took longer to locate than congruent targets (Experiments 1, 2, and 3) and that this segmentation-congruency effect decreased when the number of search items was reduced (Experiment 2). Furthermore, an analysis of eye movements revealed that participants spent more time scrutinising the target before confirming its identity on incongruent trials than on congruent trials (Experiment 3). These findings suggest that the distractor context influences target segmentation and detection during visual search. Copyright © 2014 Elsevier B.V. All rights reserved.

A semiotics of comedy: Moving figures and shifting grounds of Chapayeka ritual clown performance

DEFF Research Database (Denmark)

Keisalo, Marianna Päivikki

2016-01-01

This article develops an analytic approach to comedic performance by examining the performance of the Chapayeka ritual clowns as a series of semiotic shifts and reversals: the Chapayekas play with images and contexts, introducing unpredictable figures to effectively shift the grounding conditions...... to function as both symbolic figures in the ritual and self-contained contextual grounds, which enables them to produce further signs and manipulate figure-ground relations within and beyond the ritual. The analytic view developed here is informed by the complex and multilayered semiotics of comedic...

Time-Correlated Single-Photon Counting Range Profiling of Moving Objects

Directory of Open Access Journals (Sweden)

Hedborg Julia

2016-01-01

TCSPC is a statistic method that requires an acquisition time and therefore the range profile of a non-stationary object (target may be corrupted. Here, we present results showing that it is possible to reconstruct the range profile of a moving target and calculate the velocity of the target.

Learning the trajectory of a moving visual target and evolution of its tracking in the monkey

Science.gov (United States)

Bourrelly, Clara; Quinet, Julie; Cavanagh, Patrick

2016-01-01

An object moving in the visual field triggers a saccade that brings its image onto the fovea. It is followed by a combination of slow eye movements and catch-up saccades that try to keep the target image on the fovea as long as possible. The accuracy of this ability to track the “here-and-now” location of a visual target contrasts with the spatiotemporally distributed nature of its encoding in the brain. We show in six experimentally naive monkeys how this performance is acquired and gradually evolves during successive daily sessions. During the early exposure, the tracking is mostly saltatory, made of relatively large saccades separated by low eye velocity episodes, demonstrating that accurate (here and now) pursuit is not spontaneous and that gaze direction lags behind its location most of the time. Over the sessions, while the pursuit velocity is enhanced, the gaze is more frequently directed toward the current target location as a consequence of a 25% reduction in the number of catch-up saccades and a 37% reduction in size (for the first saccade). This smoothing is observed at several scales: during the course of single trials, across the set of trials within a session, and over successive sessions. We explain the neurophysiological processes responsible for this combined evolution of saccades and pursuit in the absence of stringent training constraints. More generally, our study shows that the oculomotor system can be used to discover the neural mechanisms underlying the ability to synchronize a motor effector with a dynamic external event. PMID:27683886

Study of intense pulse irradiation effects on silicon targets considered as ground matter for optical detectors

International Nuclear Information System (INIS)

Muller, O.

1994-12-01

This study aim was centered on morphological and structural alterations induced by laser irradiation on silicon targets considered as ground matter for optical detectors. First we recalled the main high light intensity effects on the condensed matter. Then we presented the experimental aspects. The experimental studies were achieved on two sample types: SiO 2 /Si and Si. Two topics were studied: the defect chronology according to wavelength and pulse length, and the crystalline quality as well as the structure defects of irradiated zones by Raman spectroscopy. Finally, irradiation of Si targets by intense pulsed beams may lead to material fusion. This phenomenon is particularly easy when the material is absorbent, when the pulse is short and when the material is superficially oxidized. (MML). 204 refs., 93 figs., 21 tabs., 1 appendix

Target size matters: target errors contribute to the generalization of implicit visuomotor learning.

Science.gov (United States)

Reichenthal, Maayan; Avraham, Guy; Karniel, Amir; Shmuelof, Lior

2016-08-01

The process of sensorimotor adaptation is considered to be driven by errors. While sensory prediction errors, defined as the difference between the planned and the actual movement of the cursor, drive implicit learning processes, target errors (e.g., the distance of the cursor from the target) are thought to drive explicit learning mechanisms. This distinction was mainly studied in the context of arm reaching tasks where the position and the size of the target were constant. We hypothesize that in a dynamic reaching environment, where subjects have to hit moving targets and the targets' dynamic characteristics affect task success, implicit processes will benefit from target errors as well. We examine the effect of target errors on learning of an unnoticed perturbation during unconstrained reaching movements. Subjects played a Pong game, in which they had to hit a moving ball by moving a paddle controlled by their hand. During the game, the movement of the paddle was gradually rotated with respect to the hand, reaching a final rotation of 25°. Subjects were assigned to one of two groups: The high-target error group played the Pong with a small ball, and the low-target error group played with a big ball. Before and after the Pong game, subjects performed open-loop reaching movements toward static targets with no visual feedback. While both groups adapted to the rotation, the postrotation reaching movements were directionally biased only in the small-ball group. This result provides evidence that implicit adaptation is sensitive to target errors. Copyright © 2016 the American Physiological Society.

Flash trajectory imaging of target 3D motion

Science.gov (United States)

Wang, Xinwei; Zhou, Yan; Fan, Songtao; He, Jun; Liu, Yuliang

2011-03-01

We present a flash trajectory imaging technique which can directly obtain target trajectory and realize non-contact measurement of motion parameters by range-gated imaging and time delay integration. Range-gated imaging gives the range of targets and realizes silhouette detection which can directly extract targets from complex background and decrease the complexity of moving target image processing. Time delay integration increases information of one single frame of image so that one can directly gain the moving trajectory. In this paper, we have studied the algorithm about flash trajectory imaging and performed initial experiments which successfully obtained the trajectory of a falling badminton. Our research demonstrates that flash trajectory imaging is an effective approach to imaging target trajectory and can give motion parameters of moving targets.

SmoothMoves : Smooth pursuits head movements for augmented reality

NARCIS (Netherlands)

Esteves, Augusto; Verweij, David; Suraiya, Liza; Islam, Rasel; Lee, Youryang; Oakley, Ian

2017-01-01

SmoothMoves is an interaction technique for augmented reality (AR) based on smooth pursuits head movements. It works by computing correlations between the movements of on-screen targets and the user's head while tracking those targets. The paper presents three studies. The first suggests that head

Exploration of a Polarized Surface Bidirectional Reflectance Model Using the Ground-Based Multiangle SpectroPolarimetric Imager

Directory of Open Access Journals (Sweden)

David J. Diner

2012-12-01

Full Text Available Accurate characterization of surface reflection is essential for retrieval of aerosols using downward-looking remote sensors. In this paper, observations from the Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI are used to evaluate a surface polarized bidirectional reflectance distribution function (PBRDF model. GroundMSPI is an eight-band spectropolarimetric camera mounted on a rotating gimbal to acquire pushbroom imagery of outdoor landscapes. The camera uses a very accurate photoelastic-modulator-based polarimetric imaging technique to acquire Stokes vector measurements in three of the instrument’s bands (470, 660, and 865 nm. A description of the instrument is presented, and observations of selected targets within a scene acquired on 6 January 2010 are analyzed. Data collected during the course of the day as the Sun moved across the sky provided a range of illumination geometries that facilitated evaluation of the surface model, which is comprised of a volumetric reflection term represented by the modified Rahman-Pinty-Verstraete function plus a specular reflection term generated by a randomly oriented array of Fresnel-reflecting microfacets. While the model is fairly successful in predicting the polarized reflection from two grass targets in the scene, it does a poorer job for two manmade targets (a parking lot and a truck roof, possibly due to their greater degree of geometric organization. Several empirical adjustments to the model are explored and lead to improved fits to the data. For all targets, the data support the notion of spectral invariance in the angular shape of the unpolarized and polarized surface reflection. As noted by others, this behavior provides valuable constraints on the aerosol retrieval problem, and highlights the importance of multiangle observations.

Kinesthetic information facilitates saccades towards proprioceptive-tactile targets.

Science.gov (United States)

Voudouris, Dimitris; Goettker, Alexander; Mueller, Stefanie; Fiehler, Katja

2016-05-01

Saccades to somatosensory targets have longer latencies and are less accurate and precise than saccades to visual targets. Here we examined how different somatosensory information influences the planning and control of saccadic eye movements. Participants fixated a central cross and initiated a saccade as fast as possible in response to a tactile stimulus that was presented to either the index or the middle fingertip of their unseen left hand. In a static condition, the hand remained at a target location for the entire block of trials and the stimulus was presented at a fixed time after an auditory tone. Therefore, the target location was derived only from proprioceptive and tactile information. In a moving condition, the hand was first actively moved to the same target location and the stimulus was then presented immediately. Thus, in the moving condition additional kinesthetic information about the target location was available. We found shorter saccade latencies in the moving compared to the static condition, but no differences in accuracy or precision of saccadic endpoints. In a second experiment, we introduced variable delays after the auditory tone (static condition) or after the end of the hand movement (moving condition) in order to reduce the predictability of the moment of the stimulation and to allow more time to process the kinesthetic information. Again, we found shorter latencies in the moving compared to the static condition but no improvement in saccade accuracy or precision. In a third experiment, we showed that the shorter saccade latencies in the moving condition cannot be explained by the temporal proximity between the relevant event (auditory tone or end of hand movement) and the moment of the stimulation. Our findings suggest that kinesthetic information facilitates planning, but not control, of saccadic eye movements to proprioceptive-tactile targets. Copyright © 2016 Elsevier Ltd. All rights reserved.

An investigation of the challenges in reconstructing PET images of a freely moving animal

International Nuclear Information System (INIS)

Akhtar, Mahmood; Kyme, Andre; Meikle, Steven; Zhou, Victor; Fulton, Roger

2013-01-01

Imaging the brain of a freely moving small animal using positron emission tomography (PET) while simultaneously observing its behaviour is an important goal for neuroscience. While we have successfully demonstrated the use of line-of-response (LOR) rebinning to correct the head motion of confined animals, a large proportion of events may need to be discarded because they either 'miss' the detector array after transformation or fall out of the acceptance range of a sinogram. The proportion of events that would have been measured had motion not occurred, so-called 'lost events', is expected to be even larger for freely moving animals. Moreover, the data acquisition in the case of a freely moving animal is further complicated by a complex attenuation field. The aims of this study were (a) to characterise the severity of 'lost events' problem for the freely moving animal scenario, and (b) to investigate the relative impact of attenuation correction errors on quantitative accuracy of reconstructed images. A phantom study was performed to simulate the uncorrelated motion of a target and non-target source volume. A small animal PET scanner was used to acquire list-mode data for different sets of phantom positions. The list-mode data were processed using the standard LOR rebinning approach, and multiple frame variants of this designed to reduce discarded events. We found that LOR rebinning caused up to 86 % 'lost events', and artifacts that we attribute to incomplete projections, when applied to a freely moving target. This fraction was reduced by up to 18 % using the variant approaches, resulting in slightly reduced image artifacts. The effect of the non-target compartment on attenuation correction of the target volume was surprisingly small. However, for certain poses where the target and non-target volumes are aligned transaxially in the field-of-view, the attenuation problem becomes more complex and sophisticated correction methods will be required. We conclude that

Random walk of passive tracers among randomly moving obstacles.

Science.gov (United States)

Gori, Matteo; Donato, Irene; Floriani, Elena; Nardecchia, Ilaria; Pettini, Marco

2016-04-14

This study is mainly motivated by the need of understanding how the diffusion behavior of a biomolecule (or even of a larger object) is affected by other moving macromolecules, organelles, and so on, inside a living cell, whence the possibility of understanding whether or not a randomly walking biomolecule is also subject to a long-range force field driving it to its target. By means of the Continuous Time Random Walk (CTRW) technique the topic of random walk in random environment is here considered in the case of a passively diffusing particle among randomly moving and interacting obstacles. The relevant physical quantity which is worked out is the diffusion coefficient of the passive tracer which is computed as a function of the average inter-obstacles distance. The results reported here suggest that if a biomolecule, let us call it a test molecule, moves towards its target in the presence of other independently interacting molecules, its motion can be considerably slowed down.

Synthesis of High-Frequency Ground Motion Using Information Extracted from Low-Frequency Ground Motion

Science.gov (United States)

Iwaki, A.; Fujiwara, H.

2012-12-01

Broadband ground motion computations of scenario earthquakes are often based on hybrid methods that are the combinations of deterministic approach in lower frequency band and stochastic approach in higher frequency band. Typical computation methods for low-frequency and high-frequency (LF and HF, respectively) ground motions are the numerical simulations, such as finite-difference and finite-element methods based on three-dimensional velocity structure model, and the stochastic Green's function method, respectively. In such hybrid methods, LF and HF wave fields are generated through two different methods that are completely independent of each other, and are combined at the matching frequency. However, LF and HF wave fields are essentially not independent as long as they are from the same event. In this study, we focus on the relation among acceleration envelopes at different frequency bands, and attempt to synthesize HF ground motion using the information extracted from LF ground motion, aiming to propose a new method for broad-band strong motion prediction. Our study area is Kanto area, Japan. We use the K-NET and KiK-net surface acceleration data and compute RMS envelope at four frequency bands: 0.5-1.0 Hz, 1.0-2.0 Hz, 2.0-4.0 Hz, .0-8.0 Hz, and 8.0-16.0 Hz. Taking the ratio of the envelopes of adjacent bands, we find that the envelope ratios have stable shapes at each site. The empirical envelope-ratio characteristics are combined with low-frequency envelope of the target earthquake to synthesize HF ground motion. We have applied the method to M5-class earthquakes and a M7 target earthquake that occurred in the vicinity of Kanto area, and successfully reproduced the observed HF ground motion of the target earthquake. The method can be applied to a broad band ground motion simulation for a scenario earthquake by combining numerically-computed low-frequency (~1 Hz) ground motion with the empirical envelope ratio characteristics to generate broadband ground motion

Artifacts in Radar Imaging of Moving Targets

Science.gov (United States)

2012-09-01

CA, USA, 2007. [11] B. Borden, Radar imaging of airborne targets: A primer for Applied mathematicians and Physicists . New York, NY: Taylor and... Project (0704–0188) Washington DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 21 September 2012 3. REPORT TYPE AND DATES COVERED...CW Continuous Wave DAC Digital to Analog Convertor DFT Discrete Fourier Transform FBP Filtered Back Projection FFT Fast Fourier Transform GPS

Introduction. Leave no stone unturned: Perspectives on ground stone artefact research

OpenAIRE

Danny Rosenberg; Yorke Rowan; Tatjana Gluhak

2016-01-01

Ground stone tools served in many physical and social contexts through millennia, reflecting a wide variety of functions. Although ground stone tool studies were neglected for much of early archaeology, the last few decades witnessed a notable international uptick in the way archaeologists confront this multifaceted topic. Today, with the advance of archaeology as a discipline, research into ground stone artefacts is moving into a new phase that integrates high resolution documentation with n...

Automatic target classification of man-made objects in synthetic aperture radar images using Gabor wavelet and neural network

Science.gov (United States)

Vasuki, Perumal; Roomi, S. Mohamed Mansoor

2013-01-01

Processing of synthetic aperture radar (SAR) images has led to the development of automatic target classification approaches. These approaches help to classify individual and mass military ground vehicles. This work aims to develop an automatic target classification technique to classify military targets like truck/tank/armored car/cannon/bulldozer. The proposed method consists of three stages via preprocessing, feature extraction, and neural network (NN). The first stage removes speckle noise in a SAR image by the identified frost filter and enhances the image by histogram equalization. The second stage uses a Gabor wavelet to extract the image features. The third stage classifies the target by an NN classifier using image features. The proposed work performs better than its counterparts, like K-nearest neighbor (KNN). The proposed work performs better on databases like moving and stationary target acquisition and recognition against the earlier methods by KNN.

Water budget for SRP burial ground area

International Nuclear Information System (INIS)

Hubbard, J.E.; Emslie, R.H.

1984-01-01

Radionuclide migration from the SRP burial ground for solid low-level waste has been studied extensively. Most of the buried radionuclides are fixed on the soil and show negligible movement. The major exception is tritium, which when leached from the waste by percolating rainfall, forms tritiated water and moves with the groundwater. The presence of tritium has been useful in tracing groundwater flow paths to outcrop. A subsurface tritium plume moving from the southwest corner of the burial ground toward an outcrop near Four Mile Creek has been defined. Groundwater movement is so slow that much of the tritium decays before reaching the outcrop. The burial ground tritium plume defined to date is virtually all in the uppermost sediment layer, the Barnwell Formation. The purpose of the study reported in this memorandum was to investigate the hypothesis that deeper flow paths, capable of carrying substantial amounts of tritium, may exist in the vicinity of the burial ground. As a first step in seeking deeper flow paths, a water budget was constructed for the burial ground site. The water budget, a materials balance used by hydrologists, is expressed in annual area inches of rainfall. Components of the water budget for the burial ground area were analyzed to determine whether significant flow paths may exist below the tan clay. Mean annual precipitation was estimated as 47 inches, with evapotranspiration, run-off, and groundwater recharge estimated as 30, 2, and 15 inches, respectively. These estimates, when combined with groundwater discharge data, suggest that 5 inches of the groundwater recharge flow above the tan clay and that 10 inches flow below the tan clay. Therefore, two-thirds of the groundwater recharge appears to follow flow paths that are deeper than those previously found. 13 references, 10 figures, 5 tables

Masking interrupts figure-ground signals in V1.

Science.gov (United States)

Lamme, Victor A F; Zipser, Karl; Spekreijse, Henk

2002-10-01

In a backward masking paradigm, a target stimulus is rapidly (figure-ground segregation can be recorded. Here, we recorded from awake macaque monkeys, engaged in a task where they had to detect figures from background in a pattern backward masking paradigm. We show that the V1 figure-ground signals are selectively and fully suppressed at target-mask intervals that psychophysically result in the target being invisible. Initial response transients, signalling the features that make up the scene, are not affected. As figure-ground modulations depend on feedback from extrastriate areas, these results suggest that masking selectively interrupts the recurrent interactions between V1 and higher visual areas.

Evaluation of the interplay effect when using RapidArc to treat targets moving in the craniocaudal or right-left direction

International Nuclear Information System (INIS)

Court, Laurence; Wagar, Matthew; Berbeco, Ross; Reisner, Adam; Winey, Brian; Schofield, Debbie; Ionascu, Dan; Allen, Aaron M.; Popple, Richard; Lingos, Tania

2010-01-01

Purpose: We have investigated the dosimetric errors caused by the interplay between the motions of the LINAC and the tumor during the delivery of a volume modulated arc therapy treatment. This includes the development of an IMRT QA technique, applied here to evaluate RapidArc plans of varying complexity. Methods: An IMRT QA technique was developed, which involves taking a movie of the delivered dose (0.2 s frames) using a 2D ion chamber array. Each frame of the movie is then moved according to a respiratory trace and the cumulative dose calculated. The advantage of this approach is that the impact of turning the beam on at different points in the respiratory trace, and of different types of motion, can be evaluated using data from a single irradiation. We evaluated this technique by comparing with the results when we actually moved the phantom during irradiation. RapidArc plans were created to treat a 62 cc spherical tumor in a lung phantom (16 plans) and a 454 cc irregular tumor in an actual patient (five plans). The complexity of each field was controlled by adjusting the MU (312-966 MU). Each plan was delivered to a phantom, and a movie of the delivered dose taken using a 2D ion chamber array. Patient motion was modeled by shifting each dose frame according to a respiratory trace, starting the motion at different phases. The expected dose distribution was calculated by blurring the static dose distribution with the target motion. The dose error due to the interplay effect was then calculated by comparing the delivered dose with the expected dose distribution. Peak-to-peak motion of 0.5, 1.0, and 2.0 cm in the craniocaudal and right-left directions, with target periods of 3 and 5 s, were evaluated for each plan (252 different target motion/plan combinations). Results: The daily dose error due to the interplay effect was less than 10% for 98.4% of all pixels in the target for all plans investigated. The percentage of pixels for which the daily dose error could be

Impacts on terrestrial biodiversity of moving from a 2°C to a 1.5°C target

Science.gov (United States)

Smith, Pete; Price, Jeff; Molotoks, Amy; Warren, Rachel; Malhi, Yadvinder

2018-05-01

We applied a recently developed tool to examine the reduction in climate risk to biodiversity in moving from a 2°C to a 1.5°C target. We then reviewed the recent literature examining the impact of (a) land-based mitigation options and (b) land-based greenhouse gas removal options on biodiversity. We show that holding warming to 1.5°C versus 2°C can significantly reduce the number of species facing a potential loss of 50% of their climatic range. Further, there would be an increase of 5.5-14% of the globe that could potentially act as climatic refugia for plants and animals, an area equivalent to the current global protected area network. Efforts to meet the 1.5°C target through mitigation could largely be consistent with biodiversity protection/enhancement. For impacts of land-based greenhouse gas removal technologies on biodiversity, some (e.g. soil carbon sequestration) could be neutral or positive, others (e.g. bioenergy with carbon capture and storage) are likely to lead to conflicts, while still others (e.g. afforestation/reforestation) are context-specific, when applied at scales necessary for meaningful greenhouse gas removal. Additional effort to meet the 1.5°C target presents some risks, particularly if inappropriately managed, but it also presents opportunities. This article is part of the theme issue `The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.

Moving Shadow Detection in Video Using Cepstrum

Directory of Open Access Journals (Sweden)

Fuat Cogun

2013-01-01

Full Text Available Moving shadows constitute problems in various applications such as image segmentation and object tracking. The main cause of these problems is the misclassification of the shadow pixels as target pixels. Therefore, the use of an accurate and reliable shadow detection method is essential to realize intelligent video processing applications. In this paper, a cepstrum-based method for moving shadow detection is presented. The proposed method is tested on outdoor and indoor video sequences using well-known benchmark test sets. To show the improvements over previous approaches, quantitative metrics are introduced and comparisons based on these metrics are made.

Detection and identification of human targets in radar data

Science.gov (United States)

Gürbüz, Sevgi Z.; Melvin, William L.; Williams, Douglas B.

2007-04-01

Radar offers unique advantages over other sensors, such as visual or seismic sensors, for human target detection. Many situations, especially military applications, prevent the placement of video cameras or implantment seismic sensors in the area being observed, because of security or other threats. However, radar can operate far away from potential targets, and functions during daytime as well as nighttime, in virtually all weather conditions. In this paper, we examine the problem of human target detection and identification using single-channel, airborne, synthetic aperture radar (SAR). Human targets are differentiated from other detected slow-moving targets by analyzing the spectrogram of each potential target. Human spectrograms are unique, and can be used not just to identify targets as human, but also to determine features about the human target being observed, such as size, gender, action, and speed. A 12-point human model, together with kinematic equations of motion for each body part, is used to calculate the expected target return and spectrogram. A MATLAB simulation environment is developed including ground clutter, human and non-human targets for the testing of spectrogram-based detection and identification algorithms. Simulations show that spectrograms have some ability to detect and identify human targets in low noise. An example gender discrimination system correctly detected 83.97% of males and 91.11% of females. The problems and limitations of spectrogram-based methods in high clutter environments are discussed. The SNR loss inherent to spectrogram-based methods is quantified. An alternate detection and identification method that will be used as a basis for future work is proposed.

Figure-ground segregation can rely on differences in motion direction.

Science.gov (United States)

Kandil, Farid I; Fahle, Manfred

2004-12-01

If the elements within a figure move synchronously while those in the surround move at a different time, the figure is easily segregated from the surround and thus perceived. Lee and Blake (1999) [Visual form created solely from temporal structure. Science, 284, 1165-1168] demonstrated that this figure-ground separation may be based not only on time differences between motion onsets, but also on the differences between reversals of motion direction. However, Farid and Adelson (2001) [Synchrony does not promote grouping in temporally structured displays. Nature Neuroscience, 4, 875-876] argued that figure-ground segregation in the motion-reversal experiment might have been based on a contrast artefact and concluded that (a)synchrony as such was 'not responsible for the perception of form in these or earlier displays'. Here, we present experiments that avoid contrast artefacts but still produce figure-ground segregation based on purely temporal cues. Our results show that subjects can segregate figure from ground even though being unable to use motion reversals as such. Subjects detect the figure when either (i) motion stops (leading to contrast artefacts), or (ii) motion directions differ between figure and ground. Segregation requires minimum delays of about 15 ms. We argue that whatever the underlying cues and mechanisms, a second stage beyond motion detection is required to globally compare the outputs of local motion detectors and to segregate figure from ground. Since analogous changes take place in both figure and ground in rapid succession, this second stage has to detect the asynchrony with high temporal precision.

Developing a Leadership Identity: A Grounded Theory

Science.gov (United States)

Komives, Susan R.; Owen, Julie E; Longerbeam, Susan D.; Mainella, Felicia C.; Osteen, Laura

2005-01-01

This grounded theory study on developing a leadership identity revealed a 6-stage developmental process. The thirteen diverse students in this study described their leadership identity as moving from a leader-centric view to one that embraced leadership as a collaborative, relational process. Developing a leadership identity was connected to the…

Heavy water jet target and a beryllium target for production of fast neutrons

International Nuclear Information System (INIS)

Logan, C.M.; Anderson, J.D.; Barschall, H.H.; Davis, J.C.

1975-01-01

A limitation on the neutron flux obtainable from proton or deuteron induced reactions is the heating of the target by the accelerated charged particles. The heat can be removed more easily if the target moves. The possibility of using a rotating Be target and a heavy water jet as a target for bombardment by 35-MeV deuterons was studied. In a thick Be metal target moving at 10 m/sec through such a beam of 1 cm diameter a temperature pulse of about 300 0 C will be produced by the 0.3 MW beam. The Be target should be able to withstand such a temperature pulse. A Be target suitable for 3 MW of power in a 1 cm diameter beam would require internal cooling and a higher velocity. A free jet of heavy water is also a possible target. Laser photographs of water jets in vacuum show small angles of divergence. The effect of heating by a 0.3 MW beam is probably not important because the temperature rise produced by the beam is small compared to the absolute temperature of the unheated jet. (auth)

Close-up of primary and secondary asteroseismic CoRoT targets and the ground-based follow-up observations

Energy Technology Data Exchange (ETDEWEB)

Uytterhoeven, K; Poretti, E; Rainer, M; Mantegazza, L [INAF-Brera Astronomical Observatory, Via E. Bianchi 46, 23807 Merate (Italy); Zima, W; Aerts, C; Morel, T; Lefever, K [Institute of Astronomy, KULeuven, Celestijnenlaan 200D, 3001 Leuven (Belgium); Miglio, A [Institut d' Astrophysique et de Geophysique de l' Universite de Liege, Allee du 6 Aout 17, 4000 Liege (Belgium); Amado, P J; MartIn-Ruiz, S [Instituto de AstrofIsica de AndalucIa (CSIC), Apartado 3004, 18080 Granada (Spain); Mathias, P; Valtier, J C [Observatoire de la Cote d' Azur, GEMINI, CNRS, Universite Nice Sophia-Antipolis, BP 4229, 06304 Nice Cedex 4 (France); Paparo, M; Benkoe, J M [Konkoly Observatory, PO Box 67, 1525 Budapest (Hungary)], E-mail: katrien.uytterhoeven@brera.inaf.it

2008-10-15

To optimise the science results of the asteroseismic part of the CoRoT satellite mission a complementary simultaneous ground-based observational campaign is organised for selected CoRoT targets. The observations include both high-resolution spectroscopic and multicolour photometric data. We present the preliminary results of the analysis of the ground-based observations of three targets. A line-profile analysis of 216 high-resolution FEROS spectra of the {delta} Sct star HD 50844 reveals more than ten pulsation frequencies in the frequency range 5-18 d{sup -1}, including possibly one radial fundamental mode (6.92 d{sup -1}). Based on more than 600 multi-colour photometric datapoints of the {beta} Cep star HD 180642, spanning about three years and obtained with different telescopes and different instruments, we confirm the presence of a dominant radial mode {nu}{sub 1} = 5.48695 d{sup -1}, and detect also its first two harmonics. We find evidence for a second mode {nu}{sub 2} = 0.3017 d{sup -1}, possibly a g-mode, and indications for two more frequencies in the 7-8 d{sup -1} domain. From Stromgren photometry we find evidence for the hybrid 5 Sct/{gamma} Dor character of the F0 star HD 44195, as frequencies near 3 d{sup -1} and 21 d{sup -1} are detected simultaneously in the different filters.

Dynamic tire pressure sensor for measuring ground vibration.

Science.gov (United States)

Wang, Qi; McDaniel, James Gregory; Wang, Ming L

2012-11-07

This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application.

Advanced LWIR hyperspectral sensor for on-the-move proximal detection of liquid/solid contaminants on surfaces

Science.gov (United States)

Giblin, Jay P.; Dixon, John; Dupuis, Julia R.; Cosofret, Bogdan R.; Marinelli, William J.

2017-05-01

Sensor technologies capable of detecting low vapor pressure liquid surface contaminants, as well as solids, in a noncontact fashion while on-the-move continues to be an important need for the U.S. Army. In this paper, we discuss the development of a long-wave infrared (LWIR, 8-10.5 μm) spatial heterodyne spectrometer coupled with an LWIR illuminator and an automated detection algorithm for detection of surface contaminants from a moving vehicle. The system is designed to detect surface contaminants by repetitively collecting LWIR reflectance spectra of the ground. Detection and identification of surface contaminants is based on spectral correlation of the measured LWIR ground reflectance spectra with high fidelity library spectra and the system's cumulative binary detection response from the sampled ground. We present the concepts of the detection algorithm through a discussion of the system signal model. In addition, we present reflectance spectra of surfaces contaminated with a liquid CWA simulant, triethyl phosphate (TEP), and a solid simulant, acetaminophen acquired while the sensor was stationary and on-the-move. Surfaces included CARC painted steel, asphalt, concrete, and sand. The data collected was analyzed to determine the probability of detecting 800 μm diameter contaminant particles at a 0.5 g/m2 areal density with the SHSCAD traversing a surface.

Impacts on terrestrial biodiversity of moving from a 2°C to a 1.5°C target

Science.gov (United States)

Price, Jeff; Molotoks, Amy; Warren, Rachel

2018-01-01

We applied a recently developed tool to examine the reduction in climate risk to biodiversity in moving from a 2°C to a 1.5°C target. We then reviewed the recent literature examining the impact of (a) land-based mitigation options and (b) land-based greenhouse gas removal options on biodiversity. We show that holding warming to 1.5°C versus 2°C can significantly reduce the number of species facing a potential loss of 50% of their climatic range. Further, there would be an increase of 5.5–14% of the globe that could potentially act as climatic refugia for plants and animals, an area equivalent to the current global protected area network. Efforts to meet the 1.5°C target through mitigation could largely be consistent with biodiversity protection/enhancement. For impacts of land-based greenhouse gas removal technologies on biodiversity, some (e.g. soil carbon sequestration) could be neutral or positive, others (e.g. bioenergy with carbon capture and storage) are likely to lead to conflicts, while still others (e.g. afforestation/reforestation) are context-specific, when applied at scales necessary for meaningful greenhouse gas removal. Additional effort to meet the 1.5°C target presents some risks, particularly if inappropriately managed, but it also presents opportunities. This article is part of the theme issue ‘The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'. PMID:29610386

Target Tracking in 3-D Using Estimation Based Nonlinear Control Laws for UAVs

Directory of Open Access Journals (Sweden)

Mousumi Ahmed

2016-02-01

Full Text Available This paper presents an estimation based backstepping like control law design for an Unmanned Aerial Vehicle (UAV to track a moving target in 3-D space. A ground-based sensor or an onboard seeker antenna provides range, azimuth angle, and elevation angle measurements to a chaser UAV that implements an extended Kalman filter (EKF to estimate the full state of the target. A nonlinear controller then utilizes this estimated target state and the chaser’s state to provide speed, flight path, and course/heading angle commands to the chaser UAV. Tracking performance with respect to measurement uncertainty is evaluated for three cases: (1 stationary white noise; (2 stationary colored noise and (3 non-stationary (range correlated white noise. Furthermore, in an effort to improve tracking performance, the measurement model is made more realistic by taking into consideration range-dependent uncertainties in the measurements, i.e., as the chaser closes in on the target, measurement uncertainties are reduced in the EKF, thus providing the UAV with more accurate control commands. Simulation results for these cases are shown to illustrate target state estimation and trajectory tracking performance.

Detection of range migrating targets in compound-Gaussian clutter

NARCIS (Netherlands)

Petrov, N.; le Chevalier, F.; Yarovyi, O.

2018-01-01

This paper deals with the problem of coherent radar detection of fast moving targets in a high range resolution mode. In particular, we are focusing on the spiky clutter modeled as a compound Gaussian process with rapidly varying power along range. Additionally, a fast moving target of interest has

Electromagnetic modelling of Ground Penetrating Radar responses to complex targets

Science.gov (United States)

Pajewski, Lara; Giannopoulos, Antonis

2014-05-01

defined through a constant real value, or else its frequency-dispersion properties can be taken into account by incorporating into the model Debye approximations. The electromagnetic source can be represented as a simple line of current (in the case of two-dimensional models), a Hertzian dipole, a bow tie antenna, or else, the realistic description of a commercial antenna can be included in the model [2]. Preliminary results for some of the proposed cells are presented, obtained by using GprMax [3], a freeware tool which solves Maxwell's equations by using a second order in space and time Finite-Difference Time-Domain algorithm. B-Scans and A-Scans are calculated at 1.5 GHz, for the total electric field and for the field back-scattered by targets embedded in the cells. A detailed description of the structures, together with the relevant numerical results obtained to date, are available for the scientific community on the website of COST Action TU1208, www.GPRadar.eu. Research groups working on the development of electromagnetic forward- and inverse-scattering techniques, as well as on imaging methods, might test and compare the accuracy and applicability of their approaches on the proposed set of scenarios. The aim of this initiative is not that of identifying the best methods, but more properly to indicate the range of reliability of each approach, highlighting its advantages and drawbacks. In the future, the realisation of the proposed concrete cells and the acquisition of GPR experimental data would allow a very effective benchmark for forward and inverse scattering methods. References [1] R. Yelf, A. Ward, "Nine steps to concrete wisdom." Proc. 13th International Conference on Ground Penetrating Radar, Lecce, Italy, 21-25 June 2010, pp. 1-8. [2] C. Warren, A. Giannopoulos, "Creating FDTD models of commercial GPR antennas using Taguchi's optimisation method." Geophysics (2011), 76, article ID G37. [3] A. Giannopoulos, "Modelling ground penetrating radar by GPRMAX

Plug and Play Realtime Diagnosis for Ground Processing System Integration, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA's "Ground Systems Development and Operations Program" is moving towards transforming parts of the Kennedy Space Center from a historically government-only...

The Moving Group Targets of the Seeds High-Contrast Imaging Survey of Exoplanets and Disks: Results and Observations from the First Three Years

Science.gov (United States)

Brandt, Timothy D.; Kuzuhara, Masayuki; McElwain, Michael W.; Schlieder, Joshua E.; Wisniewski, John P.; Turner, Edwin L.; Carson, J.; Matsuo, T.; Biller, B.; Bonnefoy, M.;

Error Analysis of Relative Calibration for RCS Measurement on Ground Plane Range

Directory of Open Access Journals (Sweden)

Wu Peng-fei

2012-03-01

Full Text Available Ground plane range is a kind of outdoor Radar Cross Section (RCS test range used for static measurement of full-size or scaled targets. Starting from the characteristics of ground plane range, the impact of environments on targets and calibrators is analyzed during calibration in the RCS measurements. The error of relative calibration produced by the different illumination of target and calibrator is studied. The relative calibration technique used in ground plane range is to place the calibrator on a fixed and auxiliary pylon somewhere between the radar and the target under test. By considering the effect of ground reflection and antenna pattern, the relationship between the magnitude of echoes and the position of calibrator is discussed. According to the different distances between the calibrator and target, the difference between free space and ground plane range is studied and the error of relative calibration is calculated. Numerical simulation results are presented with useful conclusions. The relative calibration error varies with the position of calibrator, frequency and antenna beam width. In most case, set calibrator close to the target may keep the error under control.

Introducing Grounded Theory into translation studies | Wehrmeyer ...

African Journals Online (AJOL)

This article introduces tenets of Grounded Theory into a reception-oriented model for translation studies, in which the basis of comparison (tertium comparationis) between source and target texts is constructed from target audience expectancy norms. The model is primarily designed for projects where conformity to target ...

High-Capacity Free-Space Optical Communications Between a Ground Transmitter and a Ground Receiver via a UAV Using Multiplexing of Multiple Orbital-Angular-Momentum Beams.

Science.gov (United States)

Li, Long; Zhang, Runzhou; Zhao, Zhe; Xie, Guodong; Liao, Peicheng; Pang, Kai; Song, Haoqian; Liu, Cong; Ren, Yongxiong; Labroille, Guillaume; Jian, Pu; Starodubov, Dmitry; Lynn, Brittany; Bock, Robert; Tur, Moshe; Willner, Alan E

2017-12-12

We explore the use of orbital-angular-momentum (OAM)-multiplexing to increase the capacity of free-space data transmission to moving platforms, with an added potential benefit of decreasing the probability of data intercept. Specifically, we experimentally demonstrate and characterize the performance of an OAM-multiplexed, free-space optical (FSO) communications link between a ground transmitter and a ground receiver via a moving unmanned-aerial-vehicle (UAV). We achieve a total capacity of 80 Gbit/s up to 100-m-roundtrip link by multiplexing 2 OAM beams, each carrying a 40-Gbit/s quadrature-phase-shift-keying (QPSK) signal. Moreover, we investigate for static, hovering, and moving conditions the effects of channel impairments, including: misalignments, propeller-induced airflows, power loss, intermodal crosstalk, and system bit error rate (BER). We find the following: (a) when the UAV hovers in the air, the power on the desired mode fluctuates by 2.1 dB, while the crosstalk to the other mode is -19 dB below the power on the desired mode; and (b) when the UAV moves in the air, the power fluctuation on the desired mode increases to 4.3 dB and the crosstalk to the other mode increases to -10 dB. Furthermore, the channel crosstalk decreases with an increase in OAM mode spacing.

X-ray determination of charge states of ions moving in solids

International Nuclear Information System (INIS)

Fortner, R.J.; Matthews, D.L.

1974-02-01

The first part of this work discusses previous measurements of x-ray spectra and thick-target yields for Ar ions moving in solid graphite targets. These data are strongly affected by ''solid target effects.'' There are some rather serious limitations in the above measurements. This proposal solicits funds to expand the program to eliminate the limitations. The second part of the proposal contains a more detailed presentation of three types of measurements. These involve the extension of work to other collision systems, the development of an Auger electron spectrometer, and the use of a 7-m grazing-incidence spectrograph for x-ray spectroscopy. These measurements will enable testing of current pictures describing ions moving in solids and shed light on the feasibility of producing a beam of ions which could give rise to amplified stimulated x-ray emission (x-ray laser). (11 figures) (U.S.)

Strategies used to walk through a moving aperture.

Science.gov (United States)

Cinelli, Michael E; Patla, Aftab E; Allard, Fran

2008-05-01

The objectives of the study were to determine what strategy (pursuit or interception) individuals used to pass through an oscillating target and to determine if individuals walked towards where they were looking. Kinematic and gaze behaviour data was collected from seven healthy female participants as they started at one of five different starting positions and walked 7 m towards an oscillating target. The target was a two-dimensional 70 cm aperture made by two-76 cm wide doors and oscillated between two end posts that were 300 cm apart. In order to quantify the objectives, target-heading angles [Fajen BR, Warren WH. Behavioral dynamics of steering, obstacle avoidance, and route selection. J Exp Psychol Hum Percept Perform 2003;29(2):343-62; Fajen BR, Warren WH. Visual guidance of intercepting a moving target on foot. Perception 2004;33:689-715] were calculated. Results showed that the participants used neither an interception nor a pursuit strategy to successfully pass through the moving aperture. The participants steered towards the middle of the pathway prior to passing through the middle of the aperture. A cross correlation between the horizontal gaze locations and the medial/lateral (M/L) location of the participants' center of mass (COM) was performed. The results from the cross correlation show that during the final 2s prior to crossing the aperture, the participants walked where they were looking. The findings from this study suggest that individuals simplify a task by decreasing the perceptual load until the final stages. In this way the final stages of this task were visually driven.

Planar Near-Field Measurements of Ground Penetrating Radar Antennas

DEFF Research Database (Denmark)

Meincke, Peter; Hansen, Thorkild

2004-01-01

Planar near-field measurements are formulated for a general ground penetrating radar (GPR) antenna. A total plane-wave scattering matrix is defined for the system consisting of the GPR antenna and the planar air-soil interface. The transmitting spectrum of the GPR antenna is expressed in terms...... of measurements obtained with a buried probe as the GPR antenna moves over a scan plane on the ground. A numerical example in which the scan plane is finite validates the expressions for the spectrum of the GPR antenna....

Moving Target Techniques: Leveraging Uncertainty for Cyber Defense

Science.gov (United States)

2015-12-15

program’s source code and is not possible with proprietary, third - party software for which source code is not made available. Furthermore, ensuring...implemented in most modern operating systems including Linux, Windows, Mac OSX, Android , and iOS. By randomizing the addresses, ASLR makes exploit...applications, and software versions that are running on the target machine to develop an attack against it. During the third phase, the attacker

Space imaging measurement system based on fixed lens and moving detector

Science.gov (United States)

Akiyama, Akira; Doshida, Minoru; Mutoh, Eiichiro; Kumagai, Hideo; Yamada, Hirofumi; Ishii, Hiromitsu

2006-08-01

We have developed the Space Imaging Measurement System based on the fixed lens and fast moving detector to the control of the autonomous ground vehicle. The space measurement is the most important task in the development of the autonomous ground vehicle. In this study we move the detector back and forth along the optical axis at the fast rate to measure the three-dimensional image data. This system is just appropriate to the autonomous ground vehicle because this system does not send out any optical energy to measure the distance and keep the safety. And we use the digital camera of the visible ray range. Therefore it gives us the cost reduction of the three-dimensional image data acquisition with respect to the imaging laser system. We can combine many pieces of the narrow space imaging measurement data to construct the wide range three-dimensional data. This gives us the improvement of the image recognition with respect to the object space. To develop the fast movement of the detector, we build the counter mass balance in the mechanical crank system of the Space Imaging Measurement System. And then we set up the duct to prevent the optical noise due to the ray not coming through lens. The object distance is derived from the focus distance which related to the best focused image data. The best focused image data is selected from the image of the maximum standard deviation in the standard deviations of series images.

Volume rendering in treatment planning for moving targets

Energy Technology Data Exchange (ETDEWEB)

Gemmel, Alexander [GSI-Biophysics, Darmstadt (Germany); Massachusetts General Hospital, Boston (United States); Wolfgang, John A.; Chen, George T.Y. [Massachusetts General Hospital, Boston (United States)

2009-07-01

Advances in computer technologies have facilitated the development of tools for 3-dimensional visualization of CT-data sets with volume rendering. The company Fovia has introduced a high definition volume rendering engine (HDVR trademark by Fovia Inc., Palo Alto, USA) that is capable of representing large CT data sets with high user interactivity even on standard PCs. Fovia provides a software development kit (SDK) that offers control of all the features of the rendering engine. We extended the SDK by functionalities specific to the task of treatment planning for moving tumors. This included navigation of the patient's anatomy in beam's eye view, fast point-and-click measurement of lung tumor trajectories as well as estimation of range perturbations due to motion by calculation of (differential) water equivalent path lengths for protons and carbon ions on 4D-CT data sets. We present patient examples to demonstrate the advantages and disadvantages of volume rendered images as compared to standard 2-dimensional axial plane images. Furthermore, we show an example of a range perturbation analysis. We conclude that volume rendering is a powerful technique for the representation and analysis of large time resolved data sets in treatment planning.

Timescale Halo: Average-Speed Targets Elicit More Positive and Less Negative Attributions than Slow or Fast Targets

Science.gov (United States)

Hernandez, Ivan; Preston, Jesse Lee; Hepler, Justin

2014-01-01

Research on the timescale bias has found that observers perceive more capacity for mind in targets moving at an average speed, relative to slow or fast moving targets. The present research revisited the timescale bias as a type of halo effect, where normal-speed people elicit positive evaluations and abnormal-speed (slow and fast) people elicit negative evaluations. In two studies, participants viewed videos of people walking at a slow, average, or fast speed. We find evidence for a timescale halo effect: people walking at an average-speed were attributed more positive mental traits, but fewer negative mental traits, relative to slow or fast moving people. These effects held across both cognitive and emotional dimensions of mind and were mediated by overall positive/negative ratings of the person. These results suggest that, rather than eliciting greater perceptions of general mind, the timescale bias may reflect a generalized positivity toward average speed people relative to slow or fast moving people. PMID:24421882

"Slow-scanning" in Ground-based Mid-infrared Observations

Science.gov (United States)

Ohsawa, Ryou; Sako, Shigeyuki; Miyata, Takashi; Kamizuka, Takafumi; Okada, Kazushi; Mori, Kiyoshi; Uchiyama, Masahito S.; Yamaguchi, Junpei; Fujiyoshi, Takuya; Morii, Mikio; Ikeda, Shiro

2018-04-01

Chopping observations with a tip-tilt secondary mirror have conventionally been used in ground-based mid-infrared observations. However, it is not practical for next generation large telescopes to have a large tip-tilt mirror that moves at a frequency larger than a few hertz. We propose an alternative observing method, a "slow-scanning" observation. Images are continuously captured as movie data, while the field of view is slowly moved. The signal from an astronomical object is extracted from the movie data by a low-rank and sparse matrix decomposition. The performance of the "slow-scanning" observation was tested in an experimental observation with Subaru/COMICS. The quality of a resultant image in the "slow-scanning" observation was as good as in a conventional chopping observation with COMICS, at least for a bright point-source object. The observational efficiency in the "slow-scanning" observation was better than that in the chopping observation. The results suggest that the "slow-scanning" observation can be a competitive method for the Subaru telescope and be of potential interest to other ground-based facilities to avoid chopping.

Feature Extraction in Radar Target Classification

Directory of Open Access Journals (Sweden)

Z. Kus

1999-09-01

Full Text Available This paper presents experimental results of extracting features in the Radar Target Classification process using the J frequency band pulse radar. The feature extraction is based on frequency analysis methods, the discrete-time Fourier Transform (DFT and Multiple Signal Characterisation (MUSIC, based on the detection of Doppler effect. The analysis has turned to the preference of DFT with implemented Hanning windowing function. We assumed to classify targets-vehicles into two classes, the wheeled vehicle and tracked vehicle. The results show that it is possible to classify them only while moving. The feature of the class results from a movement of moving parts of the vehicle. However, we have not found any feature to classify the wheeled and tracked vehicles while non-moving, although their engines are on.

A search asymmetry reversed by figure-ground assignment.

Science.gov (United States)

Humphreys, G W; Müller, H

2000-05-01

We report evidence demonstrating that a search asymmetry favoring concave over convex targets can be reversed by altering the figure-ground assignment of edges in shapes. Visual search for a concave target among convex distractors is faster than search for a convex target among concave distractors (a search asymmetry). By using shapes with ambiguous local figure-ground relations, we demonstrated that search can be efficient (with search slopes around 10 ms/item) or inefficient (with search slopes around 30-40 ms/item) with the same stimuli, depending on whether edges are assigned to concave or convex "figures." This assignment process can operate in a top-down manner, according to the task set. The results suggest that attention is allocated to spatial regions following the computation of figure-ground relations in parallel across the elements present. This computation can also be modulated by top-down processes.

A Basic Fourier Transform Pair for Slant Range-Doppler Modeling of Moving Scatterers for SAR Applications: Theory

National Research Council Canada - National Science Library

Sabry, R

2007-01-01

Considering the exploitation needs associated with the Synthetic Aperture Radar (SAR) applications involving moving and non-stationary targets, a fundamental spectral domain model for moving point and distribution of scatterers is presented...

Moving Beyond Motive-based categories of Targeted Violence

Energy Technology Data Exchange (ETDEWEB)

Weine, Stevan [Univ. of Illinois, Chicago, IL (United States); Cohen, John [Rutgers Univ., New Brunswick, NJ (United States); Brannegan, David [Argonne National Lab. (ANL), Argonne, IL (United States)

2015-10-01

Today’s categories for responding to targeted violence are motive-based and tend to drive policies, practices, training, media coverage, and research. These categories are based on the assumption that there are significant differences between ideological and non-ideological actors and between domestic and international actors. We question the reliance on these categories and offer an alternative way to frame the response to multiple forms of targeted violence. We propose adopting a community-based multidisciplinary approach to assess risk and provide interventions that are focused on the pre-criminal space. We describe four capabilities that should be implemented locally by establishing and maintaining multidisciplinary response teams that combine community and law-enforcement components: (1) community members are educated, making them better able to identify and report patterns associated with elevated risk for violence; (2) community-based professionals are trained to assess the risks for violent behavior posed by individuals; (3) community-based professionals learn to implement strategies that directly intervene in causal factors for those individuals who are at elevated risk; and (4) community-based professionals learn to monitor and assess an individual’s risk for violent behaviors on an ongoing basis. Community-based multidisciplinary response teams have the potential to identify and help persons in the pre-criminal space and to reduce barriers that have traditionally impeded community/law-enforcement collaboration.

Moving Stimuli Facilitate Synchronization But Not Temporal Perception.

Science.gov (United States)

Silva, Susana; Castro, São Luís

2016-01-01

Recent studies have shown that a moving visual stimulus (e.g., a bouncing ball) facilitates synchronization compared to a static stimulus (e.g., a flashing light), and that it can even be as effective as an auditory beep. We asked a group of participants to perform different tasks with four stimulus types: beeps, siren-like sounds, visual flashes (static) and bouncing balls. First, participants performed synchronization with isochronous sequences (stimulus-guided synchronization), followed by a continuation phase in which the stimulus was internally generated (imagery-guided synchronization). Then they performed a perception task, in which they judged whether the final part of a temporal sequence was compatible with the previous beat structure (stimulus-guided perception). Similar to synchronization, an imagery-guided variant was added, in which sequences contained a gap in between (imagery-guided perception). Balls outperformed flashes and matched beeps (powerful ball effect) in stimulus-guided synchronization but not in perception (stimulus- or imagery-guided). In imagery-guided synchronization, performance accuracy decreased for beeps and balls, but not for flashes and sirens. Our findings suggest that the advantages of moving visual stimuli over static ones are grounded in action rather than perception, and they support the hypothesis that the sensorimotor coupling mechanisms for auditory (beeps) and moving visual stimuli (bouncing balls) overlap.

Small UAS Analysis of Laser Designation and Search and Target Acquisition Capabilities in an Urban Environment

National Research Council Canada - National Science Library

Harclerode, Eric

2008-01-01

Conclusions: -Small UAS has extreme difficulty lasing moving targets in high density urban environments -Lasing moving targets in medium density terrain is possible but not certain -Lasing of stationary targets...

A neural model of visual figure-ground segregation from kinetic occlusion.

Science.gov (United States)

Barnes, Timothy; Mingolla, Ennio

2013-01-01

Freezing is an effective defense strategy for some prey, because their predators rely on visual motion to distinguish objects from their surroundings. An object moving over a background progressively covers (deletes) and uncovers (accretes) background texture while simultaneously producing discontinuities in the optic flow field. These events unambiguously specify kinetic occlusion and can produce a crisp edge, depth perception, and figure-ground segmentation between identically textured surfaces--percepts which all disappear without motion. Given two abutting regions of uniform random texture with different motion velocities, one region appears to be situated farther away and behind the other (i.e., the ground) if its texture is accreted or deleted at the boundary between the regions, irrespective of region and boundary velocities. Consequently, a region with moving texture appears farther away than a stationary region if the boundary is stationary, but it appears closer (i.e., the figure) if the boundary is moving coherently with the moving texture. A computational model of visual areas V1 and V2 shows how interactions between orientation- and direction-selective cells first create a motion-defined boundary and then signal kinetic occlusion at that boundary. Activation of model occlusion detectors tuned to a particular velocity results in the model assigning the adjacent surface with a matching velocity to the far depth. A weak speed-depth bias brings faster-moving texture regions forward in depth in the absence of occlusion (shearing motion). These processes together reproduce human psychophysical reports of depth ordering for key cases of kinetic occlusion displays. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ground movements associated with gas hydrate production

International Nuclear Information System (INIS)

Siriwardane, H.J.; Kutuk, B.

1992-03-01

This report deals with a study directed towards a modeling effort on production related ground movements and subsidence resulting from hydrate dissociation. The goal of this research study was to evaluate whether there could be subsidence related problems that could be an impediment to hydrate production. During the production of gas from a hydrate reservoir, it is expected that porous reservoir matrix becomes more compressible which may cause reservoir compression (compaction) under the influence of overburden weight. The overburden deformations can propagate its influence upwards causing subsidence near the surface where production equipment will be located. In the present study, the reservoir compaction is modeled by using the conventional ''stress equilibrium'' approach. In this approach, the overburden strata move under the influence of body force (i.e. self weight) in response to the ''cavity'' generated by reservoir depletion. The present study is expected to provide a ''lower bound'' solution to the subsidence caused by hydrate reservoir depletion. The reservoir compaction anticipated during hydrate production was modeled by using the finite element method, which is a powerful computer modeling technique. The ground movements at the reservoir roof (i.e. reservoir compression) cause additional stresses and disturbance in the overburden strata. In this study, the reservoir compaction was modeled by using the conventional ''stress equilibrium'' approach. In this approach, the overburden strata move under the influence of body force (i.e. self weight) in response to the ''cavity'' generated by reservoir depletion. The resulting stresses and ground movements were computed by using the finite element method. Based on the parameters used in this investigation, the maximum ground subsidence could vary anywhere from 0.50 to 6.50 inches depending on the overburden depth and the size of the depleted hydrate reservoir

The influence of pore-fluid in the soil on ground vibrations from a tunnel embedded in a layered half-space

Science.gov (United States)

Yuan, Zonghao; Cao, Zhigang; Boström, Anders; Cai, Yuanqiang

2018-04-01

A computationally efficient semi-analytical solution for ground-borne vibrations from underground railways is proposed and used to investigate the influence of hydraulic boundary conditions at the scattering surfaces and the moving ground water table on ground vibrations. The arrangement of a dry soil layer with varying thickness resting on a saturated poroelastic half-space, which includes a circular tunnel subject to a harmonic load at the tunnel invert, creates the scenario of a moving water table for research purposes in this paper. The tunnel is modelled as a hollow cylinder, which is made of viscoelastic material and buried in the half-space below the ground water table. The wave field in the dry soil layer consists of up-going and down-going waves while the wave field in the tunnel wall consists of outgoing and regular cylindrical waves. The complete solution for the saturated half-space with a cylindrical hole is composed of down-going plane waves and outgoing cylindrical waves. By adopting traction-free boundary conditions on the ground surface and continuity conditions at the interfaces of the two soil layers and of the tunnel and the surrounding soil, a set of algebraic equations can be obtained and solved in the transformed domain. Numerical results show that the moving ground water table can cause an uncertainty of up to 20 dB for surface vibrations.

Moving In, Moving Through, and Moving Out: The Transitional Experiences of Foster Youth College Students

Science.gov (United States)

Gamez, Sara I.

2017-01-01

The purpose of this qualitative study was to explore the transitional experiences of foster youth college students. The study explored how foster youth experienced moving into, moving through, and moving out of the college environment and what resources and strategies they used to thrive during their college transitions. In addition, this study…

Sensing across large-scale cognitive radio networks: Data processing, algorithms, and testbed for wireless tomography and moving target tracking

Science.gov (United States)

Bonior, Jason David

As the use of wireless devices has become more widespread so has the potential for utilizing wireless networks for remote sensing applications. Regular wireless communication devices are not typically designed for remote sensing. Remote sensing techniques must be carefully tailored to the capabilities of these networks before they can be applied. Experimental verification of these techniques and algorithms requires robust yet flexible testbeds. In this dissertation, two experimental testbeds for the advancement of research into sensing across large-scale cognitive radio networks are presented. System architectures, implementations, capabilities, experimental verification, and performance are discussed. One testbed is designed for the collection of scattering data to be used in RF and wireless tomography research. This system is used to collect full complex scattering data using a vector network analyzer (VNA) and amplitude-only data using non-synchronous software-defined radios (SDRs). Collected data is used to experimentally validate a technique for phase reconstruction using semidefinite relaxation and demonstrate the feasibility of wireless tomography. The second testbed is a SDR network for the collection of experimental data. The development of tools for network maintenance and data collection is presented and discussed. A novel recursive weighted centroid algorithm for device-free target localization using the variance of received signal strength for wireless links is proposed. The signal variance resulting from a moving target is modeled as having contours related to Cassini ovals. This model is used to formulate recursive weights which reduce the influence of wireless links that are farther from the target location estimate. The algorithm and its implementation on this testbed are presented and experimental results discussed.

Researches in increase of efficiency of electrokinetic process of ground cleaning from radionuclides

International Nuclear Information System (INIS)

Prozorov, L.B.; Shcheglov, M.Y.; Nikolaevsky, V.B.; Tkachenko, A.V.

2003-01-01

Potentially perspective method of decontamination of ground is electrokinetic method, which basic advantage consists in an opportunity of its application for clearing ground with low filtering by ability directly on a place of local contaminated (in situ). Thus moving the large volumes of the contaminated ground is excluded. Base of this method is the processes of electromigration and electro-osmotic, proceeding in a contaminated ground lay at imposing an electrical field of a constant current. Electrokinetic method of cleaning of ground from radionuclides provides their transfer in water-soluble, mobile form, carry as positive or negative ions under influence of an electrical field into electrode chambers with their subsequent recycling.Electrokinetic method in practice can be realized as follows: in the contaminated ground establish special electrode devices, fill their electrolyte and connect to a source of a constant current. Formed in the anode device as a result of electrochemical decomposition of water the ions of hydrogen under action of an electrical field move to the cathode, thus cooperate with a ground and superside cations of radioactive elements. Desorbed cations of contaminate act in catholyte, which periodically or continuously is exposed to clearing, for example, on sorption column. Last years the experts MosNPO Radon carry out complex researches directed on development of electrokinetic technology of cleaning ground from radionuclides and heavy metals. To the present time laboratory and bench tests of electrokinetic method are carried out. The basic attention at study of process of cleaning was given to objects contaminated Cs-137, most difficult recovery an element, which is strongly fixed by clay minerals and can enter into crystal structure. (authors)

A Benchmark for Evaluating Moving Object Indexes

DEFF Research Database (Denmark)

Chen, Su; Jensen, Christian Søndergaard; Lin, Dan

2008-01-01

that targets techniques for the indexing of the current and near-future positions of moving objects. This benchmark enables the comparison of existing and future indexing techniques. It covers important aspects of such indexes that have not previously been covered by any benchmark. Notable aspects covered......Progress in science and engineering relies on the ability to measure, reliably and in detail, pertinent properties of artifacts under design. Progress in the area of database-index design thus relies on empirical studies based on prototype implementations of indexes. This paper proposes a benchmark...... include update efficiency, query efficiency, concurrency control, and storage requirements. Next, the paper applies the benchmark to half a dozen notable moving-object indexes, thus demonstrating the viability of the benchmark and offering new insight into the performance properties of the indexes....

Tracking target objects orbiting earth using satellite-based telescopes

Science.gov (United States)

De Vries, Willem H; Olivier, Scot S; Pertica, Alexander J

2014-10-14

A system for tracking objects that are in earth orbit via a constellation or network of satellites having imaging devices is provided. An object tracking system includes a ground controller and, for each satellite in the constellation, an onboard controller. The ground controller receives ephemeris information for a target object and directs that ephemeris information be transmitted to the satellites. Each onboard controller receives ephemeris information for a target object, collects images of the target object based on the expected location of the target object at an expected time, identifies actual locations of the target object from the collected images, and identifies a next expected location at a next expected time based on the identified actual locations of the target object. The onboard controller processes the collected image to identify the actual location of the target object and transmits the actual location information to the ground controller.

Figure/ground segregation from temporal delay is best at high spatial frequencies

OpenAIRE

Kojima, Haruyuki

1998-01-01

Two experiments investigated the role of spatial frequency in performance of a figure/ground segregation task based on temporal cues. Figure orientation was much easier to judge when figure and ground portions of the target were defined exclusively by random texture composed entirely of high spatial frequencies. When target components were defined by low spatial frequencies only, the task was nearly impossible except with long temporal delay between figure and ground. These results are incons...

Attention and competition in figure-ground perception.

Science.gov (United States)

Peterson, Mary A; Salvagio, Elizabeth

2009-01-01

What are the roles of attention and competition in determining where objects lie in the visual field, a phenomenon known as figure-ground perception? In this chapter, we review evidence that attention and other high-level factors such as familiarity affect figure-ground perception, and we discuss models that implement these effects. Next, we consider the Biased Competition Model of Attention in which attention is used to resolve the competition for neural representation between two nearby stimuli; in this model the response to the stimulus that loses the competition is suppressed. In the remainder of the chapter we discuss recent behavioral evidence that figure-ground perception entails between-object competition in which the response to the shape of the losing competitor is suppressed. We also describe two experiments testing whether more attention is drawn to resolve greater figure-ground competition, as would be expected if the Biased Competition Model of Attention extends to figure-ground perception. In these experiments we find that responses to targets on the location of a losing strong competitor are slowed, consistent with the idea that the location of the losing competitor is suppressed, but responses to targets on the winning competitor are not speeded, which is inconsistent with the hypothesis that attention is used to resolve figure-ground competition. In closing, we discuss evidence that attention can operate by suppression as well as by facilitation.

A search for southern ultracool dwarfs in young moving groups

Directory of Open Access Journals (Sweden)

Deacon N.R.

2011-07-01

Full Text Available We have constructed an 800-strong red object catalogue by cross-referencing optical and infrared catalogues with an extensive proper motion catalogue compiled for red objects in the southern sky to obtain proper motions. We have applied astrometric and photometric constraints to the catalogue in order to select ultracool dwarf moving group candidates. 132 objects were found to be candidates of a moving group. From this candidate list we present initial results. Using spectroscopy we have obtained reliable spectral types and space motions, and by association with moving groups we can infer an age and composition. the further study of the remainder of our candidates will provide a large sample of young brown dwarfs and confirmed members will provide benchmark ultracool dwarfs. These will make suitable targets of AO planet searches.

Research on application of LADAR in ground vehicle recognition

Science.gov (United States)

Lan, Jinhui; Shen, Zhuoxun

2009-11-01

For the requirement of many practical applications in the field of military, the research of 3D target recognition is active. The representation that captures the salient attributes of a 3D target independent of the viewing angle will be especially useful to the automatic 3D target recognition system. This paper presents a new approach of image generation based on Laser Detection and Ranging (LADAR) data. Range image of target is obtained by transformation of point cloud. In order to extract features of different ground vehicle targets and to recognize targets, zernike moment properties of typical ground vehicle targets are researched in this paper. A technique of support vector machine is applied to the classification and recognition of target. The new method of image generation and feature representation has been applied to the outdoor experiments. Through outdoor experiments, it can be proven that the method of image generation is stability, the moments are effective to be used as features for recognition, and the LADAR can be applied to the field of 3D target recognition.

Job Surfing: Move On to Move Up.

Science.gov (United States)

Martin, Justin

1997-01-01

Looks at the process of switching jobs and changing careers. Discusses when to consider options and make the move as well as the need to be flexible and open minded. Provides a test for determining the chances of promotion and when to move on. (JOW)

Purely temporal figure-ground segregation.

Science.gov (United States)

Kandil, F I; Fahle, M

2001-05-01

Visual figure-ground segregation is achieved by exploiting differences in features such as luminance, colour, motion or presentation time between a figure and its surround. Here we determine the shortest delay times required for figure-ground segregation based on purely temporal features. Previous studies usually employed stimulus onset asynchronies between figure- and ground-containing possible artefacts based on apparent motion cues or on luminance differences. Our stimuli systematically avoid these artefacts by constantly showing 20 x 20 'colons' that flip by 90 degrees around their midpoints at constant time intervals. Colons constituting the background flip in-phase whereas those constituting the target flip with a phase delay. We tested the impact of frequency modulation and phase reduction on target detection. Younger subjects performed well above chance even at temporal delays as short as 13 ms, whilst older subjects required up to three times longer delays in some conditions. Figure-ground segregation can rely on purely temporal delays down to around 10 ms even in the absence of luminance and motion artefacts, indicating a temporal precision of cortical information processing almost an order of magnitude lower than the one required for some models of feature binding in the visual cortex [e.g. Singer, W. (1999), Curr. Opin. Neurobiol., 9, 189-194]. Hence, in our experiment, observers are unable to use temporal stimulus features with the precision required for these models.

COLOR INFLUENCES IDENTIFICATION OF THE MOVING OBJECTS MORE THAN SHAPE

Directory of Open Access Journals (Sweden)

Suncica Zdravkovic

2009-02-01

Full Text Available When people track moving objects, they concentrate on different characteristics.Recent results show that people more often concentrate on spatiotemporalthan featural properties of the objects. In other words, location and directionof motion seem to be more informative properties than the stable featuralcharacteristics. This finding contradicts some of our knowledge about cognitivesystem. Current research was done in attempt to specify the effect of featuralcharacteristics, especially color and shape. In Experiment 1, subjects were askedto track four mobile targets presented with another four moving objects. Afterthe motion has stopped, they had to mark the initial four targets. Our resultshave shown that participants pay more attention to the featural properties thanto spatiotemporal characteristics. Since our task was more difficult than thetasks typically reported in the literature, the results might be interpreted as if thesubjects relied mostly on attentional processes. The task in Experiment 2 wasmade even more difficult: the subjects were asked to direct attention on identityof every target. Consequently, the task demanded more complex cognitiveprocesses and emphasizing effects of featural properties. Results suggest thatcolor and shape does not have the same influences on multiple object tracking,but that color has more significant effect.

Determination of the number density of excited and ground Zn atoms during rf magnetron sputtering of ZnO target

Energy Technology Data Exchange (ETDEWEB)

Maaloul, L.; Gangwar, R. K.; Stafford, L., E-mail: luc.stafford@umontreal.ca [Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7 (Canada)

2015-07-15

A combination of optical absorption spectroscopy (OAS) and optical emission spectroscopy measurements was used to monitor the number density of Zn atoms in excited 4s4p ({sup 3}P{sub 2} and {sup 3}P{sub 0}) metastable states as well as in ground 4s{sup 2} ({sup 1}S{sub 0}) state in a 5 mTorr Ar radio-frequency (RF) magnetron sputtering plasma used for the deposition of ZnO-based thin films. OAS measurements revealed an increase by about one order of magnitude of Zn {sup 3}P{sub 2} and {sup 3}P{sub 0} metastable atoms by varying the self-bias voltage on the ZnO target from −115 to −300 V. Over the whole range of experimental conditions investigated, the triplet-to-singlet metastable density ratio was 5 ± 1, which matches the statistical weight ratio of these states in Boltzmann equilibrium. Construction of a Boltzmann plot using all Zn I emission lines in the 200–500 nm revealed a constant excitation temperature of 0.33 ± 0.04 eV. In combination with measured populations of Zn {sup 3}P{sub 2} and {sup 3}P{sub 0} metastable atoms, this temperature was used to extrapolate the absolute number density of ground state Zn atoms. The results were found to be in excellent agreement with those obtained previously by actinometry on Zn atoms using Ar as the actinometer gas [L. Maaloul and L. Stafford, J. Vac. Sci. Technol., A 31, 061306 (2013)]. This set of data was then correlated to spectroscopic ellipsometry measurements of the deposition rate of Zn atoms on a Si substrate positioned at 12 cm away from the ZnO target. The deposition rate scaled linearly with the number density of Zn atoms. In sharp contrast with previous studies on RF magnetron sputtering of Cu targets, these findings indicate that metastable atoms play a negligible role on the plasma deposition dynamics of Zn-based coatings.

Tunnel flexibility effect on the ground surface acceleration response

Science.gov (United States)

Baziar, Mohammad Hassan; Moghadam, Masoud Rabeti; Choo, Yun Wook; Kim, Dong-Soo

2016-09-01

Flexibility of underground structures relative to the surrounding medium, referred to as the flexibility ratio, is an important factor that influences their dynamic interaction. This study investigates the flexibility effect of a box-shaped subway tunnel, resting directly on bedrock, on the ground surface acceleration response using a numerical model verified against dynamic centrifuge test results. A comparison of the ground surface acceleration response for tunnel models with different flexibility ratios revealed that the tunnels with different flexibility ratios influence the acceleration response at the ground surface in different ways. Tunnels with lower flexibility ratios have higher acceleration responses at short periods, whereas tunnels with higher flexibility ratios have higher acceleration responses at longer periods. The effect of the flexibility ratio on ground surface acceleration is more prominent in the high range of frequencies. Furthermore, as the flexibility ratio of the tunnel system increases, the acceleration response moves away from the free field response and shifts towards the longer periods. Therefore, the flexibility ratio of the underground tunnels influences the peak ground acceleration (PGA) at the ground surface, and may need to be considered in the seismic zonation of urban areas.

Analysis on Target Detection and Classification in LTE Based Passive Forward Scattering Radar

Directory of Open Access Journals (Sweden)

Raja Syamsul Azmir Raja Abdullah

2016-09-01

Full Text Available The passive bistatic radar (PBR system can utilize the illuminator of opportunity to enhance radar capability. By utilizing the forward scattering technique and procedure into the specific mode of PBR can provide an improvement in target detection and classification. The system is known as passive Forward Scattering Radar (FSR. The passive FSR system can exploit the peculiar advantage of the enhancement in forward scatter radar cross section (FSRCS for target detection. Thus, the aim of this paper is to show the feasibility of passive FSR for moving target detection and classification by experimental analysis and results. The signal source is coming from the latest technology of 4G Long-Term Evolution (LTE base station. A detailed explanation on the passive FSR receiver circuit, the detection scheme and the classification algorithm are given. In addition, the proposed passive FSR circuit employs the self-mixing technique at the receiver; hence the synchronization signal from the transmitter is not required. The experimental results confirm the passive FSR system’s capability for ground target detection and classification. Furthermore, this paper illustrates the first classification result in the passive FSR system. The great potential in the passive FSR system provides a new research area in passive radar that can be used for diverse remote monitoring applications.

Analysis on Target Detection and Classification in LTE Based Passive Forward Scattering Radar.

Science.gov (United States)

Raja Abdullah, Raja Syamsul Azmir; Abdul Aziz, Noor Hafizah; Abdul Rashid, Nur Emileen; Ahmad Salah, Asem; Hashim, Fazirulhisyam

2016-09-29

The passive bistatic radar (PBR) system can utilize the illuminator of opportunity to enhance radar capability. By utilizing the forward scattering technique and procedure into the specific mode of PBR can provide an improvement in target detection and classification. The system is known as passive Forward Scattering Radar (FSR). The passive FSR system can exploit the peculiar advantage of the enhancement in forward scatter radar cross section (FSRCS) for target detection. Thus, the aim of this paper is to show the feasibility of passive FSR for moving target detection and classification by experimental analysis and results. The signal source is coming from the latest technology of 4G Long-Term Evolution (LTE) base station. A detailed explanation on the passive FSR receiver circuit, the detection scheme and the classification algorithm are given. In addition, the proposed passive FSR circuit employs the self-mixing technique at the receiver; hence the synchronization signal from the transmitter is not required. The experimental results confirm the passive FSR system's capability for ground target detection and classification. Furthermore, this paper illustrates the first classification result in the passive FSR system. The great potential in the passive FSR system provides a new research area in passive radar that can be used for diverse remote monitoring applications.

Limits to Clutter Cancellation in Multi-Aperture GMTI Data

Energy Technology Data Exchange (ETDEWEB)

Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bickel, Douglas L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-03-01

Multi-aperture or multi-subaperture antennas are fundamental to Ground Moving Target Indicator (GMTI) radar systems in order to detect slow-moving targets with Doppler characteristics similar to clutter. Herein we examine the performance of several subaperture architectures for their clutter cancelling performance. Significantly, more antenna phase centers isn’t always better, and in fact is sometimes worse, for detecting targets.

Interplanetary magnetic field rotations followed from L1 to the ground: the response of the Earth's magnetosphere as seen by multi-spacecraft and ground-based observations

Directory of Open Access Journals (Sweden)

M. Volwerk

2011-09-01

Full Text Available A study of the interaction of solar wind magnetic field rotations with the Earth's magnetosphere is performed. For this event there is, for the first time, a full coverage over the dayside magnetosphere with multiple (multispacecraft missions from dawn to dusk, combined with ground magnetometers, radar and an auroral camera, this gives a unique coverage of the response of the Earth's magnetosphere. After a long period of southward IMF Bz and high dynamic pressure of the solar wind, the Earth's magnetosphere is eroded and compressed and reacts quickly to the turning of the magnetic field. We use data from the solar wind monitors ACE and Wind and from magnetospheric missions Cluster, THEMIS, DoubleStar and Geotail to investigate the behaviour of the magnetic rotations as they move through the bow shock and magnetosheath. The response of the magnetosphere is investigated through ground magnetometers and auroral keograms. It is found that the solar wind magnetic field drapes over the magnetopause, while still co-moving with the plasma flow at the flanks. The magnetopause reacts quickly to IMF Bz changes, setting up field aligned currents, poleward moving aurorae and strong ionospheric convection. Timing of the structures between the solar wind, magnetosheath and the ground shows that the advection time of the structures, using the solar wind velocity, correlates well with the timing differences between the spacecraft. The reaction time of the magnetopause and the ionospheric current systems to changes in the magnetosheath Bz seem to be almost immediate, allowing for the advection of the structure measured by the spacecraft closest to the magnetopause.

c-Raf in KRas Mutant Cancers: A Moving Target.

Science.gov (United States)

McCormick, Frank

2018-02-12

Therapies for KRas cancers remain a major clinical need. In the current issue of Cancer Cell, Sanclemente and coworkers in Mariano Barbacid's group validate c-Raf as a prime target for these cancers. c-Raf ablation caused regression of advanced KRas G12V /Trp53 tumors, without obvious systemic toxicity and without affecting MAPK signaling. Copyright © 2018 Elsevier Inc. All rights reserved.

Moving the Journey Towards Independence: Adolescents Transitioning to Successful Diabetes Self-Management.

Science.gov (United States)

Babler, Elizabeth; Strickland, Carolyn June

2015-01-01

To gain a greater understanding of adolescent's experiences living with Type 1 diabetes mellitus (T1DM) and create a theoretical paradigm. Grounded theory as described by Glaser was used. Fifteen in-depth interviews were conducted with adolescent's ages 11-15 with T1DM. Symbolic interactionism is the theoretical framework for grounded theory. Data were collected; transcribed, coded, and analyzed simultaneously using constant comparative analysis and findings were grounded in the words of participants. A theoretical model was created with the concept of "normalizing". Normalizing was defined as the ability to integrate diabetes into one's daily life to make diabetes 'part of me'. Phase four of the model, and the focus of this manuscript was "Moving the Journey towards Independence" and included: 1) taking over care, 2) experiencing conflict with parents, and 3) realizing diabetes is hard. The major task for adolescents in this phase was separating from parents to independently manage diabetes. The normalizing task for this phase was: "taking on the burden of care". Adolescents described challenges with independent care and increased parental conflict including: fearing needles, forgetting insulin, feeling embarrassed and believing that diabetes was a burden in their life. Additionally, juggling the multiple responsibilities of home, school and work along with managing a chronic illness during adolescence is challenging. Transitioning to diabetes self-management is a challenge for adolescents. This model advances understanding of the moving processes in adolescents transitioning; additionally, hypotheses are presented that may be used for developing interventions to promote success in self-management. Copyright © 2015 Elsevier Inc. All rights reserved.

Moving targets. Economic competitiveness of nuclear power

International Nuclear Information System (INIS)

Rogner, H.H.; Langlois, L.

2000-01-01

Most world electricity markets are now moving towards greater competition, driven in part by technology, low fuel prices, and experience that competitive markets are more self-sustaining. Electric power is being sold in a number of markets in member countries of the Organization for Economic Cooperation and Development (OECD) for around US $0.02 per kilowatt-hour (kWh). Can nuclear generation match such prices? If not, can it be made to do so? Electricity companies are now in the business of selling a commodity (kWh) and commercial services instead of a strategic good. Excess capacity, low demand growth and lower product prices in major industrialized countries have forced power generators and their suppliers to be more concerned with the costs of their operations and profitability of their investments. These companies increasingly need a commercial, profit-oriented approach if they are to survive and prosper. Even more, they will need to make substantial cost reductions over the next few years. The nuclear industry is no exception. How does nuclear power stack up in this environment? The IAEA Planning and Economic Studies Section is doing a series of studies on precisely these questions, divided into issues affecting the near, medium and long-term future of nuclear power. This corresponds roughly to matters affecting existing plants, upgrades and life extensions, or new plants. In general, the studies find that nuclear power has the potential to be competitive in all three markets. But realizing that potential will require significant changes on the part of the industry and its regulators. This article focuses on the prevailing market situation in many industrialized countries. Several lessons also are applicable to developing countries, particularly in cases where the financing of electric power projects is expected to come from international capital markets. The overall situation is distinctly different for developing countries. Typically the capacity there for

Targeted Learning

CERN Document Server

van der Laan, Mark J

2011-01-01

The statistics profession is at a unique point in history. The need for valid statistical tools is greater than ever; data sets are massive, often measuring hundreds of thousands of measurements for a single subject. The field is ready to move towards clear objective benchmarks under which tools can be evaluated. Targeted learning allows (1) the full generalization and utilization of cross-validation as an estimator selection tool so that the subjective choices made by humans are now made by the machine, and (2) targeting the fitting of the probability distribution of the data toward the targe

Moving related to separation : who moves and to what distance

NARCIS (Netherlands)

Mulder, Clara H.; Malmberg, Gunnar

We address the issue of moving from the joint home on the occasion of separation. Our research question is: To what extent can the occurrence of moves related to separation, and the distance moved, be explained by ties to the location, resources, and other factors influencing the likelihood of

Figure ground segregation modulates perceived direction of ambiguous moving gratings and plaids.

Science.gov (United States)

Tommasi, L; Vallortigara, G

1999-02-01

A translating oriented grating viewed through a circular aperture with an occluding area in the middle appeared to move alternately in an oblique or in a vertical direction depending on the foreground/background assignment on the central occluding area. The effect occurred even when the central area was simply removed from the display, thus giving rise to a 'subjective' occluder. Parametric studies revealed that the probability of seeing oblique or vertical motion was affected by the size of the central area but not by its contrast relationships with the grating. Similar phenomena of ambiguous motion direction were observed using changes in colour along a translating grating that produced neon colour spreading effects, or using oriented edge discontinuities that collapsed into subjective plaids composed of two one-dimensional gratings. These results are discussed with respect to the hypothesis that surface segmentation mechanisms play a crucial part in the interpretation of motion signals.

Contamination and UV ageing of diffuser targets used in satellite inflight and ground reference test site calibrations

Science.gov (United States)

Vaskuri, Anna; Greenwell, Claire; Hessey, Isabel; Tompkins, Jordan; Woolliams, Emma

2018-02-01

Diffuser reflectance targets are key components in in-orbit calibrations and for verifying ground reference test sites. In this work, Spectralon, Diffusil, and Heraeus diffusers were exposed to exhaust gases and ultraviolet (UV) radiation in the ambient air conditions and their degradations were monitored by measuring changes in spectral reflectances. Spectralon is a state-of-the-art diffuser made of polytetrafluoroethylene, and Diffusil and Heraeus diffusers are made of fused silica with gas bubbles inside. Based on the contamination tests, Spectralon degrades faster than fused silica diffusers. For the samples exposed to contamination for 20 minutes, the 250 nm - 400 nm total diffuse spectral reflectance of Spectralon degraded 3-5 times more when exposed to petrol-like emission and 16-23 times more when exposed to diesel-like emission, compared with Diffusil. When the reflectance changes of Spectralon were compared with those of Heraeus, Spectralon degraded 3-4 times more when exposed to petrol-like emission for 20 minutes and 5-7 times more when exposed to diesel-like emission for 7.5 minutes. When the samples contaminated were exposed to UV radiation in the ambient air, their reflectance gradually restored back to the original level. In conclusion, fused silica diffusers are more resistant to hydrocarbon contaminants present in ground reference test sites, and thus more stable under UV radiation in the air.

Figure-ground segmentation can occur without attention.

Science.gov (United States)

Kimchi, Ruth; Peterson, Mary A

2008-07-01

The question of whether or not figure-ground segmentation can occur without attention is unresolved. Early theorists assumed it can, but the evidence is scant and open to alternative interpretations. Recent research indicating that attention can influence figure-ground segmentation raises the question anew. We examined this issue by asking participants to perform a demanding change-detection task on a small matrix presented on a task-irrelevant scene of alternating regions organized into figures and grounds by convexity. Independently of any change in the matrix, the figure-ground organization of the scene changed or remained the same. Changes in scene organization produced congruency effects on target-change judgments, even though, when probed with surprise questions, participants could report neither the figure-ground status of the region on which the matrix appeared nor any change in that status. When attending to the scene, participants reported figure-ground status and changes to it highly accurately. These results clearly demonstrate that figure-ground segmentation can occur without focal attention.

Quality of clinical trials: A moving target

Science.gov (United States)

Bhatt, Arun

2011-01-01

Quality of clinical trials depends on data integrity and subject protection. Globalization, outsourcing and increasing complexicity of clinical trials have made the target of achieving global quality challenging. The quality, as judged by regulatory inspections of the investigator sites, sponsors/contract research organizations and Institutional Review Board, has been of concern to the US Food and Drug Administration, as there has been hardly any change in frequency and nature of common deficiencies. To meet the regulatory expectations, the sponsors need to improve quality by developing systems with specific standards for each clinical trial process. The quality systems include: personnel roles and responsibilities, training, policies and procedures, quality assurance and auditing, document management, record retention, and reporting and corrective and preventive action. With an objective to improve quality, the FDA has planned new inspection approaches such as risk-based inspections, surveillance inspections, real-time oversight, and audit of sponsor quality systems. The FDA has partnered with Duke University for Clinical Trials Transformation Initiative, which will conduct research projects on design principles, data quality and quantity including monitoring, study start-up, and adverse event reporting. These recent initiatives will go a long way in improving quality of clinical trials. PMID:22145122

The importance of surrounding tissues and window settings for contouring of moving targets

Energy Technology Data Exchange (ETDEWEB)

Borm, Kai Joachim [Technische Universitaet Muenchen, Medical School, Munich (Germany); Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany); Oechsner, Markus; Berndt, Johannes; Combs, Stephanie Elisabeth; Molls, Michael; Duma, Marciana Nona [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany)

2015-09-15

The aim of the study was to assess the importance of surrounding tissues for the delineation of moving targets in tissue-specific phantoms and to find optimal settings for lung, soft tissue, and liver tumors. Tumor movement was simulated by a water-filled table tennis ball (target volume, TV). Three phantoms were created: corkboards to simulate lung tissue (lung phantom, LunPh), animal fat as fatty soft tissue (fatty tissue phantom, FatPh), and water enhanced with contrast medium as the liver tissue (liver phantom, LivPh). Slow planning three-dimensional compute tomography images (3D-CTs) were acquired with and without phantom movements. One-dimensional tumor movement (1D), three-dimensional tumor movement (3D), as well as a real patient's tumor trajectories were simulated. The TV was contoured using two lung window settings, two soft-tissue window settings, and one liver window setting. The volumes were compared to mathematical calculated values. TVs were underestimated in all phantoms due to movement. The use of soft-tissue windows in the LivPh led to a significantunderestimation of the TV (70.8 % of calculated TV). When common window settings [LunPh + 200 HU/-1,000 HU (upper window/lower window threshold); FatPh: + 240 HU/-120 HU; LivPh: + 175 HU/+ 50 HU] were used, the contoured TVs were: LivPh, 84.0 %; LunPh, 93.2 %, and FatPh, 92.8 %. The lower window threshold had a significant impact on the size of the delineated TV, whereas changes of the upper threshold led only to small differences. The decisive factor for window settings is the lower window threshold (for adequate TV delineation in the lung and fatty-soft tissue it should be lower than density values of surrounding tissue). The use of a liver window should be considered. (orig.) [German] Das Ziel dieser Arbeit war es, den Einfluss des umgebenden Gewebes auf die Konturierung bewegter Objekte zu untersuchen. Um die optimalen CT-Fensterungen fuer Lungen-, Weichteil- und Lebertumoren zu bestimmen

Autonomous Aerial Refueling Ground Test Demonstration—A Sensor-in-the-Loop, Non-Tracking Method

Directory of Open Access Journals (Sweden)

Chao-I Chen

2015-05-01

Full Text Available An essential capability for an unmanned aerial vehicle (UAV to extend its airborne duration without increasing the size of the aircraft is called the autonomous aerial refueling (AAR. This paper proposes a sensor-in-the-loop, non-tracking method for probe-and-drogue style autonomous aerial refueling tasks by combining sensitivity adjustments of a 3D Flash LIDAR camera with computer vision based image-processing techniques. The method overcomes the inherit ambiguity issues when reconstructing 3D information from traditional 2D images by taking advantage of ready to use 3D point cloud data from the camera, followed by well-established computer vision techniques. These techniques include curve fitting algorithms and outlier removal with the random sample consensus (RANSAC algorithm to reliably estimate the drogue center in 3D space, as well as to establish the relative position between the probe and the drogue. To demonstrate the feasibility of the proposed method on a real system, a ground navigation robot was designed and fabricated. Results presented in the paper show that using images acquired from a 3D Flash LIDAR camera as real time visual feedback, the ground robot is able to track a moving simulated drogue and continuously narrow the gap between the robot and the target autonomously.

Ground glass hepatocytes provide targets for therapy or prevention of hepatitis B virus-related hepatocellular carcinoma

Directory of Open Access Journals (Sweden)

Hong-Yi Chang

2018-03-01

Full Text Available Ground glass hepatocyte (GGH represents a histologic hallmark of chronic hepatitis B virus (HBV infection and is characterized by the accumulation of pre-S mutant surface antigens in the endoplasmic reticulum (ER. In the past decade, GGHs have been recognized as pre-neoplastic lesions of hepatocellular carcinoma (HCC. The accumulation of pre-S mutant protein in ER may induce a misfolded protein response or ER stress signals with activation of VEGF/Akt/mTOR and COX-2/NF-κB signals, leading to oxidative DNA damage, aneuploidy, and genomic instability. Molecular studies revealed clonal HBV DNA integration in type II GGHs which continue to express and secrete surface antigens, representing the sustained surface antigens in the serum after NA antiviral treatment. The persistence of GGHs in the liver after anti-viral therapy not only constitute the challenge to eliminate HBV infection but also carry the high risk to develop HCC. DNA chip and ELISA kit are designing to detect the pre-S mutants in serum. Novel or second generation anti-HBV drugs are under phase II development and include the combination of anti-virals, immunomodulators, agents for host DNA damage, and siRNA to target at the transcription of HBsAg gene in cccDNA or integrated HBV DNA. In the past years, we explored the possibility to provide drugs or natural agents targeting at ER stress signals in GGHs to prevent HCC development. In a transgenic mice model of pre-S mutant and HBx, a combination of silymarin and resveratrol targeting at mTOR and NF-κB signals could reduce a 80% of HCC development. In a pilot clinical trial, liposomal curcumin (Meriva® combined with anti-virals and immumodulators P1101 have been designed and attempted to eliminate the serum surface antigen and hence the recurrence of HCC after surgical resection. Therefore, the detection of pre-S mutants in serum or GGHs in the liver should provide rational target design for therapy or prevention of HCC in these high

Fabrication of cryogenic inertial-confinement-fusion targets using target free-fall technique. Report No. 2-82

International Nuclear Information System (INIS)

Kim, K.; Murphy, M.J.

1982-04-01

Techniques for fabricating cryogenic inertial confinement fusion targets (i.e., spherical shells containing a uniform layer of DT ice) are investigated using target free-fall concept. Detection and characterization of the moving targets are effected by optoelectronic means, of which the principal is an RF ac-interferometer. This interferometer system demonstrates, for the first time, the speed capabilities of the phase-modulation ac-interferometry. New techiques developed for handling, holding, launching, and transporting targets are also described. Results obtained at both room and cryogenic temperatures are presented

76 FR 11297 - New Regional Ground Service for Parcels

Science.gov (United States)

2011-03-01

... 3015.2.\\1\\ The proposed changes establish a new ``Regional Ground'' price category within the Parcel... Governors' Decision No. 11-2, February 17, 2011 (Notice). Regional Ground service targets higher-volume business-to-consumer Parcel Select packages delivered within the first three postal zones (300 miles) from...

Examination of earthquake Ground Motion in the deep underground environment of Japan

International Nuclear Information System (INIS)

Goto, J.; Tsuchi, H.; Mashimo, M.

2009-01-01

Among the possible impacts of earthquakes on the geological disposal system, ground motion is not included in the criteria for selecting a candidate repository site because, in general, ground motion deep underground is considered to be smaller than at the surface. Also, after backfilling/closure, the repository moves together with the surrounding rock. We have carried out a detailed examination of earthquake ground motion deep underground using extensive data from recent observation networks to support the above assumption. As a result, it has been reconfirmed that earthquake ground motion deep underground is relatively smaller than at the surface. Through detailed analysis of data, we have identified the following important parameters for evaluating earthquake ground motion deep underground: depth and velocity distribution of the rock formations of interest, the intensity of the short period component of earthquakes and incident angle of seismic waves to the rock formations. (authors)

Research on Strong Clutter Suppression for Gaofen-3 Dual-Channel SAR/GMTI

Directory of Open Access Journals (Sweden)

Mingjie Zheng

2018-03-01

Full Text Available In spaceborne synthetic aperture radar (SAR, moving targets are almost buried in ground clutter due to the wide clutter Doppler spectrum and the restricted pulse repetition frequency (PRF, which increases the difficulty of moving target detection. Clutter suppression is one of the key issues in the spaceborne SAR moving target indicator operation. In this paper, we describe the clutter suppression principle and analyze the influence of amplitude and phase error on clutter suppression. In the following, a novel dual-channel SAR clutter suppression algorithm is proposed, which is suitable for the Gaofen-3(GF-3 SAR sensor. The proposed algorithm consists of three technique steps, namely adaptive two-dimensional (2D channel calibration, refined amplitude error correction and refined phase error correction. After channel error is corrected by these procedures, the clutter component, especially a strong clutter component, can be well suppressed. The validity of the proposed algorithm is verified by GF-3 SAR real data which demonstrates the ground moving-target indication (GMTI capability of GF-3 SAR sensor.

Research on target tracking in coal mine based on optical flow method

Science.gov (United States)

Xue, Hongye; Xiao, Qingwei

2015-03-01

To recognize, track and count the bolting machine in coal mine video images, a real-time target tracking method based on the Lucas-Kanade sparse optical flow is proposed in this paper. In the method, we judge whether the moving target deviate from its trajectory, predicate and correct the position of the moving target. The method solves the problem of failure to track the target or lose the target because of the weak light, uneven illumination and blocking. Using the VC++ platform and Opencv lib we complete the recognition and tracking. The validity of the method is verified by the result of the experiment.

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.

Move up,Move out

Institute of Scientific and Technical Information of China (English)

Guo Yan

2007-01-01

@@ China has already become the world's largest manufacturer of cement,copper and steel.Chinese producers have moved onto the world stage and dominated the global consumer market from textiles to electronics with amazing speed and efficiency.

Nova target diagnostics control system

International Nuclear Information System (INIS)

Severyn, J.R.

1985-01-01

During the past year the Nova target diagnostics control system was finished and put in service. The diagnostics loft constructed to the north of the target room provides the environmental conditions required to collect reliable target diagnostic data. These improvements include equipment cooling and isolation of the power source with strict control of instrumentation grounds to eliminate data corruption due to electromagnetic pulses from the laser power-conditioning system or from target implosion effects

An optimisation algorithm for determination of treatment margins around moving and deformable targets

International Nuclear Information System (INIS)

Redpath, Anthony Thomas; Muren, Ludvig Paul

2005-01-01

Purpose: Determining treatment margins for inter-fractional motion of moving and deformable clinical target volumes (CTVs) remains a major challenge. This paper describes and applies an optimisation algorithm designed to derive such margins. Material and methods: The algorithm works by expanding the CTV, as determined from a pre-treatment or planning scan, to enclose the CTV positions observed during treatment. CTV positions during treatment may be obtained using, for example, repeat CT scanning and/or repeat electronic portal imaging (EPI). The algorithm can be applied to both individual patients and to a set of patients. The margins derived will minimise the excess volume outside the envelope that encloses all observed CTV positions (the CTV envelope). Initially, margins are set such that the envelope is more than adequately covered when the planning CTV is expanded. The algorithm uses an iterative method where the margins are sampled randomly and are then either increased or decreased randomly. The algorithm is tested on a set of 19 bladder cancer patients that underwent weekly repeat CT scanning and EPI throughout their treatment course. Results: From repeated runs on individual patients, the algorithm produces margins within a range of ±2 mm that lie among the best results found with an exhaustive search approach, and that agree within 3 mm with margins determined by a manual approach on the same data. The algorithm could be used to determine margins to cover any specified geometrical uncertainty, and allows for the determination of reduced margins by relaxing the coverage criteria, for example disregarding extreme CTV positions, or an arbitrarily selected volume fraction of the CTV envelope, and/or patients with extreme geometrical uncertainties. Conclusion: An optimisation approach to margin determination is found to give reproducible results within the accuracy required. The major advantage with this algorithm is that it is completely empirical, and it is

Variable beam dose rate and DMLC IMRT to moving body anatomy

International Nuclear Information System (INIS)

Papiez, Lech; Abolfath, Ramin M.

2008-01-01

Derivation of formulas relating leaf speeds and beam dose rates for delivering planned intensity profiles to static and moving targets in dynamic multileaf collimator (DMLC) intensity modulated radiation therapy (IMRT) is presented. The analysis of equations determining algorithms for DMLC IMRT delivery under a variable beam dose rate reveals a multitude of possible delivery strategies for a given intensity map and for any given target motion patterns. From among all equivalent delivery strategies for DMLC IMRT treatments specific subclasses of strategies can be selected to provide deliveries that are particularly suitable for clinical applications providing existing delivery devices are used. Special attention is devoted to the subclass of beam dose rate variable DMLC delivery strategies to moving body anatomy that generalize existing techniques of such deliveries in Varian DMLC irradiation methodology to static body anatomy. Few examples of deliveries from this subclass of DMLC IMRT irradiations are investigated to illustrate the principle and show practical benefits of proposed techniques.

Variable beam dose rate and DMLC IMRT to moving body anatomy

Energy Technology Data Exchange (ETDEWEB)

Papiez, Lech; Abolfath, Ramin M. [Department of Radiation Oncology, UTSouthwestern Medical Center, Dallas, Texas 75390 (United States)

2008-11-15

Derivation of formulas relating leaf speeds and beam dose rates for delivering planned intensity profiles to static and moving targets in dynamic multileaf collimator (DMLC) intensity modulated radiation therapy (IMRT) is presented. The analysis of equations determining algorithms for DMLC IMRT delivery under a variable beam dose rate reveals a multitude of possible delivery strategies for a given intensity map and for any given target motion patterns. From among all equivalent delivery strategies for DMLC IMRT treatments specific subclasses of strategies can be selected to provide deliveries that are particularly suitable for clinical applications providing existing delivery devices are used. Special attention is devoted to the subclass of beam dose rate variable DMLC delivery strategies to moving body anatomy that generalize existing techniques of such deliveries in Varian DMLC irradiation methodology to static body anatomy. Few examples of deliveries from this subclass of DMLC IMRT irradiations are investigated to illustrate the principle and show practical benefits of proposed techniques.

Quality of clinical trials: A moving target

Directory of Open Access Journals (Sweden)

Arun Bhatt

2011-01-01

Full Text Available Quality of clinical trials depends on data integrity and subject protection. Globalization, outsourcing and increasing complexicity of clinical trials have made the target of achieving global quality challenging. The quality, as judged by regulatory inspections of the investigator sites, sponsors/contract research organizations and Institutional Review Board, has been of concern to the US Food and Drug Administration, as there has been hardly any change in frequency and nature of common deficiencies. To meet the regulatory expectations, the sponsors need to improve quality by developing systems with specific standards for each clinical trial process. The quality systems include: personnel roles and responsibilities, training, policies and procedures, quality assurance and auditing, document management, record retention, and reporting and corrective and preventive action. With an objective to improve quality, the FDA has planned new inspection approaches such as risk-based inspections, surveillance inspections, real-time oversight, and audit of sponsor quality systems. The FDA has partnered with Duke University for Clinical Trials Transformation Initiative, which will conduct research projects on design principles, data quality and quantity including monitoring, study start-up, and adverse event reporting. These recent initiatives will go a long way in improving quality of clinical trials.

Piecewise affine control for fast unmanned ground vehicles

OpenAIRE

Benine Neto , André; Grand , Christophe

2012-01-01

International audience; Unmanned ground vehicles (UGV) may experience skidding when moving at high speeds, and therefore have its safety jeopardized. For this reason the nonlinear dynamics of lateral tire forces must be taken into account into the design of steering controllers for autonomous vehicles. This paper presents the design of a state feedback piecewise affine controller applied to an UGV to coordinate the steering and torque distribution inputs in order to reduce vehicle skidding on...

Postural control of elderly: moving to predictable and unpredictable targets.

NARCIS (Netherlands)

Jongman, Vera; Lamoth, Claudine J C; van Keeken, Helco; Caljouw, Simone R

2012-01-01

Impaired postural control with muscle weakness is an important predictor of falls within the elderly population.Particular daily activities that require weight shifting in order to be able to reach a specific target (a cup on a table) require continuous adjustments to keep the body's center of mass

Role of moving planes and moving spheres following Dupin cyclides

KAUST Repository

Jia, Xiaohong

2014-03-01

We provide explicit representations of three moving planes that form a μ-basis for a standard Dupin cyclide. We also show how to compute μ-bases for Dupin cyclides in general position and orientation from their implicit equations. In addition, we describe the role of moving planes and moving spheres in bridging between the implicit and rational parametric representations of these cyclides. © 2014 Elsevier B.V.

Role of moving planes and moving spheres following Dupin cyclides

KAUST Repository

Jia, Xiaohong

2014-01-01

We provide explicit representations of three moving planes that form a μ-basis for a standard Dupin cyclide. We also show how to compute μ-bases for Dupin cyclides in general position and orientation from their implicit equations. In addition, we describe the role of moving planes and moving spheres in bridging between the implicit and rational parametric representations of these cyclides. © 2014 Elsevier B.V.

Developing Performance Measures for Manned-Unmanned Teaming Skills

Science.gov (United States)

2015-02-01

Moves aircraft to safe area Utilize standardized radio communication and signal operating procedures Perform BDA Utilize Standard report formats...UAS does not conduct BDA ; assumes target is destroyed without verification UAS evaluates target; reports BDA to engaging aircraft (or...ground unit) after prompting UAS evaluates target; proactively reports BDA to engaging aircraft (or ground unit) 1 2 3 4 5 1 2 3 4 5 B

Ground Source Geothermal District Heating and Cooling System

Energy Technology Data Exchange (ETDEWEB)

Lowe, James William [Ball State Univ., Muncie, IN (United States)

2016-10-21

Ball State University converted its campus from a coal-fired steam boiler district heating system to a ground source heat pump geothermal district system that produces simultaneously hot water for heating and chilled water for cooling. This system will include the installation of 3,600 four hundred feet deep vertical closed loop boreholes making it the largest ground source geothermal district system in the country. The boreholes will act as heat exchangers and transfer heat by virtue of the earth’s ability to maintain an average temperature of 55 degree Fahrenheit. With growing international concern for global warming and the need to reduce worldwide carbon dioxide loading of the atmosphere geothermal is poised to provide the means to help reduce carbon dioxide emissions. The shift from burning coal to utilizing ground source geothermal will increase electrical consumption but an overall decrease in energy use and reduction in carbon dioxide output will be achieved. This achievement is a result of coupling the ground source geothermal boreholes with large heat pump chiller technology. The system provides the thermodynamic means to move large amounts of energy with limited energy input. Ball State University: http://cms.bsu.edu/About/Geothermal.aspx

Identifying New Members of Nearby Moving Groups

Science.gov (United States)

Holmbeck, Erika; Vican, Laura

2014-06-01

Our group has assembled a sample of 14,000 stars of spectral types B9-M9 with measured UVW Galactic space velocities and lying within 125 pc of Earth. We have identified candidate members of three nearby young (less than 100 Myr) moving groups. For stars of spectral types G5 and later, we have used the Kast spectrometer on the Shane 3m telescope at Lick Observatory to measure lithium abundance in order to determine stellar ages. With the data we have obtained from this run, we will be able to establish whether our candidates are bona fide members of the moving groups in question. I will be presenting the preliminary results from this survey, including spectra of the ~50 stars observed thus far. These nearby young stars will make excellent targets for direct imaging followup surveys, since any giant planets around young stars will still be warm, and will therefore be bright enough to detect with instruments like GPI.

Biomarkers for immunotherapy in bladder cancer: a moving target.

Science.gov (United States)

Aggen, David H; Drake, Charles G

2017-11-21

Treatment options for metastatic urothelial carcinoma (mUC) remained relative unchanged over the last 30 years with combination chemotherapy as the mainstay of treatment. Within the last year the landscape for mUC has seismically shifted following the approval of five therapies targeting the programmed cell death protein (PD-1)/programmed cell death ligand 1 (PD-L1) axis. Notably, the anti-PD-1 antibody pembrolizumab demonstrated improved OS relative to chemotherapy in a randomized phase III study for second line treatment of mUC; this level 1 evidence led to approval from the U.S. Food and Drug Administration (FDA). The PD-1 antibody nivolumab also demonstrated an overall survival benefit, in this case in comparison to historical controls. Similarly, antibodies targeting PD-L1 including atezolizumab, durvalumab, and avelumab have now received accelerated approval from the FDA as second line treatments for mUC, with durable response lasting more than 1 year in some patients. Some of these agents are approved in the first line setting as well - based on single-arm phase II studies atezolizumab and pembrolizumab received accelerated approval for first-line treatment of cisplatin ineligible patients. Despite these multiple approvals, the development of clinically useful biomarkers to determine the optimal treatment for patients remains somewhat elusive. In this review, we examine key clinical trial results with anti-PD1/PD-L1 antibodies and discuss progress towards developing novel biomarkers beyond PD-L1 expression.

Automatic Moving Object Segmentation for Freely Moving Cameras

Directory of Open Access Journals (Sweden)

Yanli Wan

2014-01-01

Full Text Available This paper proposes a new moving object segmentation algorithm for freely moving cameras which is very common for the outdoor surveillance system, the car build-in surveillance system, and the robot navigation system. A two-layer based affine transformation model optimization method is proposed for camera compensation purpose, where the outer layer iteration is used to filter the non-background feature points, and the inner layer iteration is used to estimate a refined affine model based on the RANSAC method. Then the feature points are classified into foreground and background according to the detected motion information. A geodesic based graph cut algorithm is then employed to extract the moving foreground based on the classified features. Unlike the existing global optimization or the long term feature point tracking based method, our algorithm only performs on two successive frames to segment the moving foreground, which makes it suitable for the online video processing applications. The experiment results demonstrate the effectiveness of our algorithm in both of the high accuracy and the fast speed.

Measure of Effectiveness for JSTARS Ground Moving Target Indicator: A Value Focused Thinking Approach

Science.gov (United States)

2011-03-01

while minimizing cost. Clearly, these objectives conflict with each other, but DA gives us tools to make trade -offs when dealing with multiple...provide 25 solutions to problems, instead it is an information source that provides insight about a situation, uncertainty, objectives, and trade -offs...index.htm Shoviak, M. J. (2001). Decision Analysis Methodology to Evaluate Intergrated Solid Waste Management Alternatives for a Remote Alaskan

Moving event and moving participant in aspectual conceptions

Directory of Open Access Journals (Sweden)

Izutsu Katsunobu

2016-06-01

Full Text Available This study advances an analysis of the event conception of aspectual forms in four East Asian languages: Ainu, Japanese, Korean, and Ryukyuan. As earlier studies point out, event conceptions can be divided into two major types: the moving-event type and the moving-participant type, respectively. All aspectual forms in Ainu and Korean, and most forms in Japanese and Ryukyuan are based on that type of event conception. Moving-participant oriented Ainu and movingevent oriented Japanese occupy two extremes, between which Korean and Ryukyuan stand. Notwithstanding the geographical relationships among the four languages, Ryukyuan is closer to Ainu than to Korean, whereas Korean is closer to Ainu than to Japanese.

Figure/ground segregation from temporal delay is best at high spatial frequencies.

Science.gov (United States)

Kojima, H

1998-12-01

Two experiments investigated the role of spatial frequency in performance of a figure/ground segregation task based on temporal cues. Figure orientation was much easier to judge when figure and ground portions of the target were defined exclusively by random texture composed entirely of high spatial frequencies. When target components were defined by low spatial frequencies only, the task was nearly impossible except with long temporal delay between figure and ground. These results are inconsistent with the hypothesis that M-cell activity is primarily responsible for figure/ground segregation from temporal delay. Instead, these results point to a distinction between temporal integration and temporal differentiation. Additionally, the present results can be related to recent work on the binding of spatial features over time.

Neurons Forming Optic Glomeruli Compute Figure–Ground Discriminations in Drosophila

Science.gov (United States)

Aptekar, Jacob W.; Keleş, Mehmet F.; Lu, Patrick M.; Zolotova, Nadezhda M.

2015-01-01

Many animals rely on visual figure–ground discrimination to aid in navigation, and to draw attention to salient features like conspecifics or predators. Even figures that are similar in pattern and luminance to the visual surroundings can be distinguished by the optical disparity generated by their relative motion against the ground, and yet the neural mechanisms underlying these visual discriminations are not well understood. We show in flies that a diverse array of figure–ground stimuli containing a motion-defined edge elicit statistically similar behavioral responses to one another, and statistically distinct behavioral responses from ground motion alone. From studies in larger flies and other insect species, we hypothesized that the circuitry of the lobula—one of the four, primary neuropiles of the fly optic lobe—performs this visual discrimination. Using calcium imaging of input dendrites, we then show that information encoded in cells projecting from the lobula to discrete optic glomeruli in the central brain group these sets of figure–ground stimuli in a homologous manner to the behavior; “figure-like” stimuli are coded similar to one another and “ground-like” stimuli are encoded differently. One cell class responds to the leading edge of a figure and is suppressed by ground motion. Two other classes cluster any figure-like stimuli, including a figure moving opposite the ground, distinctly from ground alone. This evidence demonstrates that lobula outputs provide a diverse basis set encoding visual features necessary for figure detection. PMID:25972183

A moving target--incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations.

Science.gov (United States)

Cooke, Steven J; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Power, Michael; Doka, Susan E; Dettmers, John M; Crook, David A; Lucas, Martyn C; Holbrook, Christopher M; Krueger, Charles C

2016-04-01

Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions.

A game theory approach to target tracking in sensor networks.

Science.gov (United States)

Gu, Dongbing

2011-02-01

In this paper, we investigate a moving-target tracking problem with sensor networks. Each sensor node has a sensor to observe the target and a processor to estimate the target position. It also has wireless communication capability but with limited range and can only communicate with neighbors. The moving target is assumed to be an intelligent agent, which is "smart" enough to escape from the detection by maximizing the estimation error. This adversary behavior makes the target tracking problem more difficult. We formulate this target estimation problem as a zero-sum game in this paper and use a minimax filter to estimate the target position. The minimax filter is a robust filter that minimizes the estimation error by considering the worst case noise. Furthermore, we develop a distributed version of the minimax filter for multiple sensor nodes. The distributed computation is implemented via modeling the information received from neighbors as measurements in the minimax filter. The simulation results show that the target tracking algorithm proposed in this paper provides a satisfactory result.

Inertial-confinement-fusion targets

International Nuclear Information System (INIS)

Hendricks, C.D.

1982-01-01

Much of the research in laser fusion has been done using simple ball on-stalk targets filled with a deuterium-tritium mixture. The targets operated in the exploding pusher mode in which the laser energy was delivered in a very short time (approx. 100 ps or less) and was absorbed by the glass wall of the target. The high energy density in the glass literally exploded the shell with the inward moving glass compressing the DT fuel to high temperatures and moderate densities. Temperatures achieved were high enough to produce DT reactions and accompanying thermonuclear neutrons and alpha particles. The primary criteria imposed on the target builders were: (1) wall thickness, (2) sphere diameter, and (3) fuel in the sphere

Shadow detection of moving objects based on multisource information in Internet of things

Science.gov (United States)

Ma, Zhen; Zhang, De-gan; Chen, Jie; Hou, Yue-xian

2017-05-01

Moving object detection is an important part in intelligent video surveillance under the banner of Internet of things. The detection of moving target's shadow is also an important step in moving object detection. On the accuracy of shadow detection will affect the detection results of the object directly. Based on the variety of shadow detection method, we find that only using one feature can't make the result of detection accurately. Then we present a new method for shadow detection which contains colour information, the invariance of optical and texture feature. Through the comprehensive analysis of the detecting results of three kinds of information, the shadow was effectively determined. It gets ideal effect in the experiment when combining advantages of various methods.

A comparison of moving object detection methods for real-time moving object detection

Science.gov (United States)

Roshan, Aditya; Zhang, Yun

2014-06-01

Moving object detection has a wide variety of applications from traffic monitoring, site monitoring, automatic theft identification, face detection to military surveillance. Many methods have been developed across the globe for moving object detection, but it is very difficult to find one which can work globally in all situations and with different types of videos. The purpose of this paper is to evaluate existing moving object detection methods which can be implemented in software on a desktop or laptop, for real time object detection. There are several moving object detection methods noted in the literature, but few of them are suitable for real time moving object detection. Most of the methods which provide for real time movement are further limited by the number of objects and the scene complexity. This paper evaluates the four most commonly used moving object detection methods as background subtraction technique, Gaussian mixture model, wavelet based and optical flow based methods. The work is based on evaluation of these four moving object detection methods using two (2) different sets of cameras and two (2) different scenes. The moving object detection methods have been implemented using MatLab and results are compared based on completeness of detected objects, noise, light change sensitivity, processing time etc. After comparison, it is observed that optical flow based method took least processing time and successfully detected boundary of moving objects which also implies that it can be implemented for real-time moving object detection.

Efficient characterization of labeling uncertainty in closely-spaced targets tracking

NARCIS (Netherlands)

Moreno Leon, Carlos; Moreno Leon, Carlos; Driessen, Hans; Mandal, Pranab K.

2016-01-01

In this paper we propose a novel solution to the labeled multi-target tracking problem. The method presented is specially effective in scenarios where the targets have once moved in close proximity. When this is the case, disregarding the labeling uncertainty present in a solution (after the targets

Target-Searching on Percolation

International Nuclear Information System (INIS)

Yang Shijie

2005-01-01

We study target-searching processes on a percolation, on which a hunter tracks a target by smelling odors it emits. The odor intensity is supposed to be inversely proportional to the distance it propagates. The Monte Carlo simulation is performed on a 2-dimensional bond-percolation above the threshold. Having no idea of the location of the target, the hunter determines its moves only by random attempts in each direction. For lager percolation connectivity p ∼> 0.90, it reveals a scaling law for the searching time versus the distance to the position of the target. The scaling exponent is dependent on the sensitivity of the hunter. For smaller p, the scaling law is broken and the probability of finding out the target significantly reduces. The hunter seems trapped in the cluster of the percolation and can hardly reach the goal.

Fast Preparation of Critical Ground States Using Superluminal Fronts

Science.gov (United States)

Agarwal, Kartiek; Bhatt, R. N.; Sondhi, S. L.

2018-05-01

We propose a spatiotemporal quench protocol that allows for the fast preparation of ground states of gapless models with Lorentz invariance. Assuming the system initially resides in the ground state of a corresponding massive model, we show that a superluminally moving "front" that locally quenches the mass, leaves behind it (in space) a state arbitrarily close to the ground state of the gapless model. Importantly, our protocol takes time O (L ) to produce the ground state of a system of size ˜Ld (d spatial dimensions), while a fully adiabatic protocol requires time ˜O (L2) to produce a state with exponential accuracy in L . The physics of the dynamical problem can be understood in terms of relativistic rarefaction of excitations generated by the mass front. We provide proof of concept by solving the proposed quench exactly for a system of free bosons in arbitrary dimensions, and for free fermions in d =1 . We discuss the role of interactions and UV effects on the free-theory idealization, before numerically illustrating the usefulness of the approach via simulations on the quantum Heisenberg spin chain.

Neurons forming optic glomeruli compute figure-ground discriminations in Drosophila.

Science.gov (United States)

Aptekar, Jacob W; Keleş, Mehmet F; Lu, Patrick M; Zolotova, Nadezhda M; Frye, Mark A

2015-05-13

Many animals rely on visual figure-ground discrimination to aid in navigation, and to draw attention to salient features like conspecifics or predators. Even figures that are similar in pattern and luminance to the visual surroundings can be distinguished by the optical disparity generated by their relative motion against the ground, and yet the neural mechanisms underlying these visual discriminations are not well understood. We show in flies that a diverse array of figure-ground stimuli containing a motion-defined edge elicit statistically similar behavioral responses to one another, and statistically distinct behavioral responses from ground motion alone. From studies in larger flies and other insect species, we hypothesized that the circuitry of the lobula--one of the four, primary neuropiles of the fly optic lobe--performs this visual discrimination. Using calcium imaging of input dendrites, we then show that information encoded in cells projecting from the lobula to discrete optic glomeruli in the central brain group these sets of figure-ground stimuli in a homologous manner to the behavior; "figure-like" stimuli are coded similar to one another and "ground-like" stimuli are encoded differently. One cell class responds to the leading edge of a figure and is suppressed by ground motion. Two other classes cluster any figure-like stimuli, including a figure moving opposite the ground, distinctly from ground alone. This evidence demonstrates that lobula outputs provide a diverse basis set encoding visual features necessary for figure detection. Copyright © 2015 the authors 0270-6474/15/357587-13$15.00/0.

General strategy for the protection of organs at risk in IMRT therapy of a moving body

International Nuclear Information System (INIS)

Abolfath, Ramin M.; Papiez, Lech

2009-01-01

We investigated protection strategies of organs at risk (OARs) in intensity modulated radiation therapy (IMRT). These strategies apply to delivery of IMRT to moving body anatomies that show relative displacement of OAR in close proximity to a tumor target. We formulated an efficient genetic algorithm which makes it possible to search for global minima in a complex landscape of multiple irradiation strategies delivering a given, predetermined intensity map to a target. The optimal strategy was investigated with respect to minimizing the dose delivered to the OAR. The optimization procedure developed relies on variability of all parameters available for control of radiation delivery in modern linear accelerators, including adaptation of leaf trajectories and simultaneous modification of beam dose rate during irradiation. We showed that the optimization algorithms lead to a significant reduction in the dose delivered to OAR in cases where organs at risk move relative to a treatment target.

General strategy for the protection of organs at risk in IMRT therapy of a moving body

Energy Technology Data Exchange (ETDEWEB)

Abolfath, Ramin M.; Papiez, Lech [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390 (United States)

2009-07-15

We investigated protection strategies of organs at risk (OARs) in intensity modulated radiation therapy (IMRT). These strategies apply to delivery of IMRT to moving body anatomies that show relative displacement of OAR in close proximity to a tumor target. We formulated an efficient genetic algorithm which makes it possible to search for global minima in a complex landscape of multiple irradiation strategies delivering a given, predetermined intensity map to a target. The optimal strategy was investigated with respect to minimizing the dose delivered to the OAR. The optimization procedure developed relies on variability of all parameters available for control of radiation delivery in modern linear accelerators, including adaptation of leaf trajectories and simultaneous modification of beam dose rate during irradiation. We showed that the optimization algorithms lead to a significant reduction in the dose delivered to OAR in cases where organs at risk move relative to a treatment target.

Adding Theoretical Grounding to Grounded Theory: Toward Multi-Grounded Theory

OpenAIRE

Göran Goldkuhl; Stefan Cronholm

2010-01-01

The purpose of this paper is to challenge some of the cornerstones of the grounded theory approach and propose an extended and alternative approach for data analysis and theory development, which the authors call multi-grounded theory (MGT). A multi-grounded theory is not only empirically grounded; it is also grounded in other ways. Three different grounding processes are acknowledged: theoretical, empirical, and internal grounding. The authors go beyond the pure inductivist approach in GT an...

Asteroseismology of solar-type stars with Kepler: III. Ground-based data

DEFF Research Database (Denmark)

Karoff, Christoffer; Molenda-Żakowicz , J.

2010-01-01

We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler Asteroseis......We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler...

Cerenkov radiation simulation in the Auger water ground detector

International Nuclear Information System (INIS)

Le Van Ngoc; Vo Van Thuan; Dang Quang Thieu

2003-01-01

The simulation of response of the Auger water Cerenkov ground detector to atmospheric shower muons in practically needed for the experimental research of cosmic rays at extreme energies. We consider here a simulation model for the process of emission and diffusion of Cerenkov photons concerned with muons moving through the detector volume with the velocity greater than the phase velocity of light in the water on purpose to define photons producing signal in the detector. (author)

Sea Ice Thickness Measurement by Ground Penetrating Radar for Ground Truth of Microwave Remote Sensing Data

Science.gov (United States)

Matsumoto, M.; Yoshimura, M.; Naoki, K.; Cho, K.; Wakabayashi, H.

2018-04-01

Observation of sea ice thickness is one of key issues to understand regional effect of global warming. One of approaches to monitor sea ice in large area is microwave remote sensing data analysis. However, ground truth must be necessary to discuss the effectivity of this kind of approach. The conventional method to acquire ground truth of ice thickness is drilling ice layer and directly measuring the thickness by a ruler. However, this method is destructive, time-consuming and limited spatial resolution. Although there are several methods to acquire ice thickness in non-destructive way, ground penetrating radar (GPR) can be effective solution because it can discriminate snow-ice and ice-sea water interface. In this paper, we carried out GPR measurement in Lake Saroma for relatively large area (200 m by 300 m, approximately) aiming to obtain grand truth for remote sensing data. GPR survey was conducted at 5 locations in the area. The direct measurement was also conducted simultaneously in order to calibrate GPR data for thickness estimation and to validate the result. Although GPR Bscan image obtained from 600MHz contains the reflection which may come from a structure under snow, the origin of the reflection is not obvious. Therefore, further analysis and interpretation of the GPR image, such as numerical simulation, additional signal processing and use of 200 MHz antenna, are required to move on thickness estimation.

Semi-autonomous unmanned ground vehicle control system

Science.gov (United States)

Anderson, Jonathan; Lee, Dah-Jye; Schoenberger, Robert; Wei, Zhaoyi; Archibald, James

2006-05-01

Unmanned Ground Vehicles (UGVs) have advantages over people in a number of different applications, ranging from sentry duty, scouting hazardous areas, convoying goods and supplies over long distances, and exploring caves and tunnels. Despite recent advances in electronics, vision, artificial intelligence, and control technologies, fully autonomous UGVs are still far from being a reality. Currently, most UGVs are fielded using tele-operation with a human in the control loop. Using tele-operations, a user controls the UGV from the relative safety and comfort of a control station and sends commands to the UGV remotely. It is difficult for the user to issue higher level commands such as patrol this corridor or move to this position while avoiding obstacles. As computer vision algorithms are implemented in hardware, the UGV can easily become partially autonomous. As Field Programmable Gate Arrays (FPGAs) become larger and more powerful, vision algorithms can run at frame rate. With the rapid development of CMOS imagers for consumer electronics, frame rate can reach as high as 200 frames per second with a small size of the region of interest. This increase in the speed of vision algorithm processing allows the UGVs to become more autonomous, as they are able to recognize and avoid obstacles in their path, track targets, or move to a recognized area. The user is able to focus on giving broad supervisory commands and goals to the UGVs, allowing the user to control multiple UGVs at once while still maintaining the convenience of working from a central base station. In this paper, we will describe a novel control system for the control of semi-autonomous UGVs. This control system combines a user interface similar to a simple tele-operation station along with a control package, including the FPGA and multiple cameras. The control package interfaces with the UGV and provides the necessary control to guide the UGV.

Anticipatory changes in control of swing foot and lower limb joints when walking onto a moving surface traveling at constant speed.

Science.gov (United States)

Hsu, Wei-Chun; Wang, Ting-Ming; Lu, Hsuan-Lun; Lu, Tung-Wu

2015-01-01

Adapting to a predictable moving surface such as an escalator is a crucial part of daily locomotor tasks in modern cities. However, the associated biomechanics have remained unexplored. In a gait laboratory, fifteen young adults walked from the ground onto a moving or a static surface while their kinematic and kinetic data were obtained for calculating foot and pelvis motions, as well as the angles and moments of the lower limb joints. Between-surface-condition comparisons were performed using a paired t-test (α = 0.05). The results showed that anticipatory locomotor adjustments occurred at least a stride before successfully walking onto the moving surface, including increasing step length and speed in the trailing step (p moving surface (p > 0.05), mainly through reduced extension of the trailing hip but increased pelvic anterior tilt and leading swing ankle plantarflexion (p moving surfaces such as escalators. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of Ground Water Near Sidney, Western Nebraska, 2004-05

Science.gov (United States)

Steele, G.V.; Sibray, S.S.; Quandt, K.A.

2007-01-01

from the Ogallala and the Brule sand. Median concentrations of nitrate varied by aquifer-2.6 milligrams per liter (Ogallala), 2.1 milligrams per liter (Brule), and 1.3 milligrams per liter (Brule sand). The chemistry of the ground water in the study area indicates that ground water flows from recharge areas in both the tableland areas and Lodgepole Creek Valley to discharge areas beyond the study area. Recharging water that percolates into the Ogallala in the tableland areas either enters the Ogallala aquifer, flows along the Ogallala-Brule contact, or enters Brule fractures or sand. Although limited in amount, ground water flowing along the Ogallala-Brule contact or in the Brule fractures or sand appears to be the predominant means by which water moves from the tableland areas to Lodgepole Creek Valley. Apparent ground-water ages from chlorofluorocarbon and sulfur hexafluoride data generally were similar. Age of ground water for most monitoring wells located in Lodgepole Creek Valley ranged from the mid- to late 1960s to the early 1990s. Ages of ground water in samples from monitoring wells located in tableland draw areas ranged from the mid-1980s to the early 1990s. Water in the Brule (areas without known secondary permeability structures) or deeper Brule sand aquifer was substantially older than water in the Ogallala aquifer and probably was recharged between 10,000 to 30,000 years before present. The stable isotopic data indicate that the ground water in the study area probably originated from precipitation. Ground water in Lodgepole Creek and the tableland areas are similar in chemistry. However, there appears to be limited interaction between ground water within the Ogallala to the north of Sidney and Lodgepole Creek Valley. Available data indicate that although some of the ground water in the Ogallala likely flows across the Ogallala-Brule contact, most of it does not move toward Lodgepole Creek.

Target tracking using DMLC for volumetric modulated arc therapy: A simulation study

Energy Technology Data Exchange (ETDEWEB)

Sun Baozhou; Rangaraj, Dharanipathy; Papiez, Lech; Oddiraju, Swetha; Yang Deshan; Li, H. Harold [Department of Radiation Oncology, School of Medicine, Washington University, 4921 Parkview Place, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, Southwestern Medical Center, University of Texas, Dallas, Texas 75390 (United States); Department of Radiation Oncology, School of Medicine, Washington University, 4921 Parkview Place, St. Louis, Missouri 63110 (United States)

2010-12-15

Purpose: Target tracking using dynamic multileaf collimator (DMLC) is a promising approach for intrafraction motion management in radiation therapy. The purpose of this work is to develop a DMLC tracking algorithm capable of delivering volumetric-modulated arc therapy (VMAT) to the targets that experience two-dimensional (2D) rigid motion in the beam's eye view. Methods: The problem of VMAT delivery to moving targets is formulated as a control problem with constraints. The relationships between gantry speed, gantry acceleration, MLC leaf-velocity, dose rate, and target motion are derived. An iterative search algorithm is developed to find numerical solutions for efficient delivery of a specific VMAT plan to the moving target using 2D DMLC tracking. The delivery of five VMAT lung plans is simulated. The planned and delivered fluence maps in the target-reference frame are calculated and compared. Results: The simulation demonstrates that the 2D tracking algorithm is capable of delivering the VMAT plan to a moving target fast and accurately without violating the machine constraints and the integrity of the treatment plan. The average delivery time is only 29 s longer than that of no-tracking delivery, 101 versus 72 s, respectively. The fluence maps are normalized to 200 MU and the average root-mean-square error between the desired and the delivered fluence is 2.1 MU, compared to 14.8 MU for no-tracking and 3.6 MU for one-dimensional tracking. Conclusions: A locally optimal MLC tracking algorithm for VMAT delivery is proposed, aiming at shortest delivery time while maintaining treatment plan invariant. The inconsequential increase of treatment time due to DMLC tracking is clinically desirable, which makes VMAT with DMLC tracking attractive in treating moving tumors.

Target Trailing With Safe Navigation for Maritime Autonomous Surface Vehicles

Science.gov (United States)

Wolf, Michael; Kuwata, Yoshiaki; Zarzhitsky, Dimitri V.

2013-01-01

This software implements a motion-planning module for a maritime autonomous surface vehicle (ASV). The module trails a given target while also avoiding static and dynamic surface hazards. When surface hazards are other moving boats, the motion planner must apply International Regulations for Avoiding Collisions at Sea (COLREGS). A key subset of these rules has been implemented in the software. In case contact with the target is lost, the software can receive and follow a "reacquisition route," provided by a complementary system, until the target is reacquired. The programmatic intention is that the trailed target is a submarine, although any mobile naval platform could serve as the target. The algorithmic approach to combining motion with a (possibly moving) goal location, while avoiding local hazards, may be applicable to robotic rovers, automated landing systems, and autonomous airships. The software operates in JPL s CARACaS (Control Architecture for Robotic Agent Command and Sensing) software architecture and relies on other modules for environmental perception data and information on the predicted detectability of the target, as well as the low-level interface to the boat controls.

Automatic target detection using binary template matching

Science.gov (United States)

Jun, Dong-San; Sun, Sun-Gu; Park, HyunWook

2005-03-01

This paper presents a new automatic target detection (ATD) algorithm to detect targets such as battle tanks and armored personal carriers in ground-to-ground scenarios. Whereas most ATD algorithms were developed for forward-looking infrared (FLIR) images, we have developed an ATD algorithm for charge-coupled device (CCD) images, which have superior quality to FLIR images in daylight. The proposed algorithm uses fast binary template matching with an adaptive binarization, which is robust to various light conditions in CCD images and saves computation time. Experimental results show that the proposed method has good detection performance.

Node Depth Adjustment Based Target Tracking in UWSNs Using Improved Harmony Search

Directory of Open Access Journals (Sweden)

Meiqin Liu

2017-12-01

Full Text Available Underwater wireless sensor networks (UWSNs can provide a promising solution to underwater target tracking. Due to the limited computation and bandwidth resources, only a small part of nodes are selected to track the target at each interval. How to improve tracking accuracy with a small number of nodes is a key problem. In recent years, a node depth adjustment system has been developed and applied to issues of network deployment and routing protocol. As far as we know, all existing tracking schemes keep underwater nodes static or moving with water flow, and node depth adjustment has not been utilized for underwater target tracking yet. This paper studies node depth adjustment method for target tracking in UWSNs. Firstly, since a Fisher Information Matrix (FIM can quantify the estimation accuracy, its relation to node depth is derived as a metric. Secondly, we formulate the node depth adjustment as an optimization problem to determine moving depth of activated node, under the constraint of moving range, the value of FIM is used as objective function, which is aimed to be minimized over moving distance of nodes. Thirdly, to efficiently solve the optimization problem, an improved Harmony Search (HS algorithm is proposed, in which the generating probability is modified to improve searching speed and accuracy. Finally, simulation results are presented to verify performance of our scheme.

Embodied affectivity: On moving and being moved

Directory of Open Access Journals (Sweden)

Thomas eFuchs

2014-06-01

Full Text Available There is a growing body of research indicating that bodily sensation and behaviour strongly influences one’s emotional reaction towards certain situations or objects. On this background, a framework model of embodied affectivity is suggested: we regard emotions as resulting from the circular interaction between affective qualities or affordances in the environment and the subject’s bodily resonance, be it in the form of sensations, postures, expressive movements or movement tendencies. Motion and emotion are thus intrinsically connected: one is moved by movement (perception; impression; affection and moved to move (action; expression; e-motion. Through its resonance, the body functions as a medium of emotional perception: it colours or charges self-experience and the environment with affective valences while it remains itself in the background of one’s own awareness. This model is then applied to emotional social understanding or interaffectivity which is regarded as an intertwinement of two cycles of embodied affectivity, thus continuously modifying each partner’s affective affordances and bodily resonance. We conclude with considerations of how embodied affectivity is altered in psychopathology and can be addressed in psychotherapy of the embodied self.

Successful range-expanding plants experience less above-ground and below-ground enemy impact.

Science.gov (United States)

Engelkes, Tim; Morriën, Elly; Verhoeven, Koen J F; Bezemer, T Martijn; Biere, Arjen; Harvey, Jeffrey A; McIntyre, Lauren M; Tamis, Wil L M; van der Putten, Wim H

2008-12-18

Many species are currently moving to higher latitudes and altitudes. However, little is known about the factors that influence the future performance of range-expanding species in their new habitats. Here we show that range-expanding plant species from a riverine area were better defended against shoot and root enemies than were related native plant species growing in the same area. We grew fifteen plant species with and without non-coevolved polyphagous locusts and cosmopolitan, polyphagous aphids. Contrary to our expectations, the locusts performed more poorly on the range-expanding plant species than on the congeneric native plant species, whereas the aphids showed no difference. The shoot herbivores reduced the biomass of the native plants more than they did that of the congeneric range expanders. Also, the range-expanding plants developed fewer pathogenic effects in their root-zone soil than did the related native species. Current predictions forecast biodiversity loss due to limitations in the ability of species to adjust to climate warming conditions in their range. Our results strongly suggest that the plants that shift ranges towards higher latitudes and altitudes may include potential invaders, as the successful range expanders may experience less control by above-ground or below-ground enemies than the natives.

A parallel spatiotemporal saliency and discriminative online learning method for visual target tracking in aerial videos.

Science.gov (United States)

Aghamohammadi, Amirhossein; Ang, Mei Choo; A Sundararajan, Elankovan; Weng, Ng Kok; Mogharrebi, Marzieh; Banihashem, Seyed Yashar

2018-01-01

Visual tracking in aerial videos is a challenging task in computer vision and remote sensing technologies due to appearance variation difficulties. Appearance variations are caused by camera and target motion, low resolution noisy images, scale changes, and pose variations. Various approaches have been proposed to deal with appearance variation difficulties in aerial videos, and amongst these methods, the spatiotemporal saliency detection approach reported promising results in the context of moving target detection. However, it is not accurate for moving target detection when visual tracking is performed under appearance variations. In this study, a visual tracking method is proposed based on spatiotemporal saliency and discriminative online learning methods to deal with appearance variations difficulties. Temporal saliency is used to represent moving target regions, and it was extracted based on the frame difference with Sauvola local adaptive thresholding algorithms. The spatial saliency is used to represent the target appearance details in candidate moving regions. SLIC superpixel segmentation, color, and moment features can be used to compute feature uniqueness and spatial compactness of saliency measurements to detect spatial saliency. It is a time consuming process, which prompted the development of a parallel algorithm to optimize and distribute the saliency detection processes that are loaded into the multi-processors. Spatiotemporal saliency is then obtained by combining the temporal and spatial saliencies to represent moving targets. Finally, a discriminative online learning algorithm was applied to generate a sample model based on spatiotemporal saliency. This sample model is then incrementally updated to detect the target in appearance variation conditions. Experiments conducted on the VIVID dataset demonstrated that the proposed visual tracking method is effective and is computationally efficient compared to state-of-the-art methods.

Detection and localization of multiple short range targets using FMCW radar signal

KAUST Repository

Jardak, Seifallah

2016-07-26

In this paper, a 24 GHz frequency-modulated continuous wave radar is used to detect and localize both stationary and moving targets. Depending on the application, the implemented software offers different modes of operation. For example, it can simply output raw data samples for advanced offline processing or directly carry out a two dimensional fast Fourier transform to estimate the location and velocity of multiple targets. To suppress clutter and detect only moving targets, two methods based on the background reduction and the slow time processing techniques are implemented. A trade-off between the two methods is presented based on their performance and the required processing time. © 2016 IEEE.

Method and apparatus for a combination moving bed thermal treatment reactor and moving bed filter

Energy Technology Data Exchange (ETDEWEB)

Badger, Phillip C.; Dunn, Jr., Kenneth J.

2015-09-01

A moving bed gasification/thermal treatment reactor includes a geometry in which moving bed reactor particles serve as both a moving bed filter and a heat carrier to provide thermal energy for thermal treatment reactions, such that the moving bed filter and the heat carrier are one and the same to remove solid particulates or droplets generated by thermal treatment processes or injected into the moving bed filter from other sources.

Diffusion of dust particles from a point-source above ground level

International Nuclear Information System (INIS)

Hassan, M.H.A.; Eltayeb, I.A.

1998-10-01

A pollutant of small particles is emitted by a point source at a height h above ground level in an atmosphere in which a uni-directional wind speed, U, is prevailing. The pollutant is subjected to diffusion in all directions in the presence of advection and settling due to gravity. The equation governing the concentration of the pollutant is studied with the wind speed and the different components of diffusion tensor are proportional to the distance above ground level and the source has a uniform strength. Adopting a Cartesian system of coordinates in which the x-axis lies along the direction of the wind velocity, the z-axis is vertically upwards and the y-axis completes the right-hand triad, the solution for the concentration c(x,y,z) is obtained in closed form. The relative importance of the components of diffusion along the three axes is discussed. It is found that for any plane y=constant (=A), c(x,y,z) is concentrated along a curve of ''extensive pollution''. In the plane A=0, the concentration decreases along the line of extensive pollution as we move away from the source. However, for planes A≅0, the line of extensive pollution possesses a point of accumulation, which lies at a nonzero value of x. As we move away from the plane A=0, the point of accumulation moves laterally away from the plane x=0 and towards the plane z=0. The presence of the point of accumulation is entirely due to the presence of lateral diffusion. (author)

Speciation and transport of radionuclides in ground water

International Nuclear Information System (INIS)

Robertson, D.E.; Toste, A.P.; Abel, K.H.; Cowan, C.E.; Jenne, E.A.; Thomas, C.W.

1984-01-01

Studies of the chemical speciation of a number of radionuclides migrating in a slightly contaminated ground water plume are identifying the most mobile species and providing an opportunity to test and/or validate geochemical models of radionuclide transport in ground waters. Results to date have shown that most of the migrating radionuclides are present in anionic or nonionic forms. These include anionic forms of 55 Fe, 60 Co, /sup 99m/Tc, 106 Ru, 131 I, and nonionic forms of 63 Ni and 125 Sb. Strontium-70 and a small fraction of the mobile 60 Co are the only cationic radionuclides which have been detected moving in the ground water plume beyond 30 meters from the source. A comparison of the observed chemical forms with the predicted species calculated from modeling thermodynamic data and ground water chemical parameters has indicated a good agreement for most of the radioelements in the system, including Tc, Np, Cs, Sr, Ce, Ru, Sb, Zn, and Mn. The discrepancies between observed and calculated solutions species were noted for Fe, Co, Ni and I. Traces of Fe, Co, and Ni were observed to migrate in anionic or nonionic forms which the calculations failed to predict. These anionic/nonionic species may be organic complexes having enhanced mobility in ground waters. The radioiodine, for example, was shown to behave totally as an anion but further investigation revealed that 49-57% of this anionic iodine was organically bound. The ground water and aqueous extracts of trench sediments contain a wide variety of organic compounds, some of which could serve as complexing agents for the radionuclides. These results indicate the need for further research at a variety of field sites in defining precisely the chemical forms of the mobile radionuclide species, and in better understanding the role of dissolved organic materials in ground water transport of radionuclides

Mitigation of Traffic-Induced Ground Vibration by Inclined Wave Barriers

DEFF Research Database (Denmark)

Andersen, Lars; Augustesen, Anders Hust

2009-01-01

Double sheet pile walls can be used as wave barriers in order to mitigate ground vibrations from railways. The present analysis concerns the efficiency of such barriers, especially with regard to the influence of the barrier inclination and the backfill between the walls. Thus, the screening capa...... of reference following the load. This allows a computation of the steady state response to a harmonically varying point source moving at different speeds typical for a train....

GMTI Direction of Arrival Measurements from Multiple Phase Centers.

Energy Technology Data Exchange (ETDEWEB)

Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bickel, Douglas L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-03-01

Ground Moving Target Indicator (GMTI) radar attempts to detect and locate targets with unknown motion. Very slow-moving targets are difficult to locate in the presence of surrounding clutter. This necessitates multiple antenna phase centers (or equivalent) to offer independent Direction of Arrival (DOA) measurements. DOA accuracy and precision generally remains dependent on target Signal-to-Noise Ratio (SNR), Clutter-toNoise Ratio (CNR), scene topography, interfering signals, and a number of antenna parameters. This is true even for adaptive techniques like Space-Time-AdaptiveProcessing (STAP) algorithms.

Analysis of the Dose Distribution of Moving Organ using a Moving Phantom System

International Nuclear Information System (INIS)

Kim, Yon Lae; Park, Byung Moon; Bae, Yong Ki; Kang, Min Young; Bang, Dong Wan; Lee, Gui Won

2006-01-01

Few researches have been performed on the dose distribution of the moving organ for radiotherapy so far. In order to simulate the organ motion caused by respiratory function, multipurpose phantom and moving device was used and dosimetric measurements for dose distribution of the moving organs were conducted in this study. The purpose of our study was to evaluate how dose distributions are changed due to respiratory motion. A multipurpose phantom and a moving device were developed for the measurement of the dose distribution of the moving organ due to respiratory function. Acryl chosen design of the phantom was considered the most obvious choice for phantom material. For construction of the phantom, we used acryl and cork with density of 1.14 g/cm 3 , 0.32 g/cm 3 respectively. Acryl and cork slab in the phantom were used to simulate the normal organ and lung respectively. The moving phantom system was composed of moving device, moving control system, and acryl and cork phantom. Gafchromic film and EDR2 film were used to measure dose distributions. The moving device system may be driven by two directional step motors and able to perform 2 dimensional movements (x, z axis), but only 1 dimensional movement(z axis) was used for this study. Larger penumbra was shown in the cork phantom than in the acryl phantom. The dose profile and isodose curve of Gafchromic EBT film were not uniform since the film has small optical density responding to the dose. As the organ motion was increased, the blurrings in penumbra, flatness, and symmetry were increased. Most of measurements of dose distributions, Gafchromic EBT film has poor flatness and symmetry than EDR2 film, but both penumbra distributions were more or less comparable. The Gafchromic EBT film is more useful as it does not need development and more radiation dose could be exposed than EDR2 film without losing film characteristics. But as response of the optical density of Gafchromic EBT film to dose is low, beam profiles

A fiber Bragg grating acceleration sensor for ground surveillance

Science.gov (United States)

Jiang, Shaodong; Zhang, Faxiang; Lv, Jingsheng; Ni, Jiasheng; Wang, Chang

2017-10-01

Ground surveillance system is a kind of intelligent monitoring equipment for detecting and tracking the ground target. This paper presents a fiber Bragg grating (FBG) acceleration sensor for ground surveillance, which has the characteristics of no power supply, anti-electromagnetic interference, easy large-scale networking, and small size. Which make it able to achieve the advantage of the ground surveillance system while avoiding the shortcoming of the electric sensing. The sensor has a double cantilever beam structure with a sensitivity of 1000 pm/g. Field experiment has been carried out on a flood beach to examine the sensor performance. The result shows that the detection distance on the walking of personnel reaches 70m, and the detection distance on the ordinary motor vehicle reaches 200m. The performance of the FBG sensor can satisfy the actual needs of the ground surveillance system.

Figure-Ground Processing: A Reassessment of Gelb and Granit.

Science.gov (United States)

Nelson, Rolf; Hebda, Nicholas

2018-03-01

In 1923, Adhemar Gelb and Ragnar Granit, two prominent researchers in early Gestalt perceptual theory, reported a lower threshold for detection of a target (a small colored dot) on the ground region of an image than on an adjacent figural region. Although their results had a wide influence on the understanding of figure-ground perception, they are at odds with more recent investigations in which figural regions appear to have a processing advantage over ground regions. The two present studies replicated Gelb and Granit's experiment using a similar figure-ground stimulus albeit with a two-alternative forced choice procedure rather than their original method of adjustment. Experiment 1 found that, contrary to Gelb and Granit's findings, a detection advantage was found for the figural over the ground region. Experiment 2 indicated that explicit contours might have played a role in detection.

The Rover Environmental Monitoring Station Ground Temperature Sensor: A Pyrometer for Measuring Ground Temperature on Mars

Directory of Open Access Journals (Sweden)

Miguel Ramos

2010-10-01

Full Text Available We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS Ground Temperature Sensor (GTS, an instrument aboard NASA’s Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor’s main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight calibration system that permits sensor recalibration when sensor sensitivity has been degraded by deposition of dust over the optics. This paper provides the first results of a GTS engineering model working in a Martian-like, extreme environment.

Random walk of passive tracers among randomly moving obstacles

OpenAIRE

Gori, Matteo; Donato, Irene; Floriani, Elena; Nardecchia, Ilaria; Pettini, Marco

2016-01-01

Background: This study is mainly motivated by the need of understanding how the diffusion behaviour of a biomolecule (or even of a larger object) is affected by other moving macromolecules, organelles, and so on, inside a living cell, whence the possibility of understanding whether or not a randomly walking biomolecule is also subject to a long-range force field driving it to its target. Method: By means of the Continuous Time Random Walk (CTRW) technique the topic of random walk in random en...

Numerical Investigation of Aerodynamic Braking for a Ground Vehicle

Science.gov (United States)

Devanuri, Jaya Krishna

2018-06-01

The purpose of this article is to observe the effect of an air brake on the aerodynamics of a ground vehicle and also to study the influence of change in the parameters like the velocity of the vehicle, the angle of inclination, height, and position of the air brake on the aerodynamics of the vehicle body. The test subject used is an Ahmed body which is a generic 3D car body as it retains all the aerodynamic characteristics of a ground vehicle. Numerical investigation has been carried out by RNG k-ɛ turbulence model. Results are presented in terms of streamlines and drag coefficient to understand the influence of pertinent parameters on flow physics. It is found that with the use of an air brake, though the drag coefficient remains more or less constant with velocity, it increases with the increase in height and angle of inclination of the air brake. But the effect of position of air brake on the coefficient of drag is surprising since for certain heights of the air brake the drag coefficient is maximum at the foremost point and as the air brake moves towards the rear it is first observed to decrease and then increase. It is also observed that with the increase in height of the air brake the drag coefficient monotonically decreases as the position of the air brake is moved towards the rear. Taguchi method has been employed with L16 orthogonal array to obtain the optimal configuration for the air brake. For each of the selected parameters, four different levels have been chosen to obtain the maximum drag coefficient value. The study could provide an invaluable database for the optimal design of an airbrake for a ground vehicle.

Familiar shapes attract attention in figure-ground displays.

Science.gov (United States)

Nelson, Rolf A; Palmer, Stephen E

2007-04-01

We report five experiments that explore the effect of figure-ground factors on attention. We hypothesized that figural cues, such as familiar shape, would draw attention to the figural side in an attentional cuing task using bipartite figure-ground displays. The first two experiments used faces in profile as the familiar shape and found a perceptual advantage for targets presented on the meaningful side of the central contour in detection speed (Experiment 1) and discrimination accuracy (Experiment 2). The third experiment demonstrated the figural advantage in response time (RT) with nine other familiar shapes (including a sea horse, a guitar, a fir tree, etc.), but only when targets appeared in close proximity to the contour. A fourth experiment obtained a figural advantage in a discrimination task with the larger set of familiar shapes. The final experiment ruled out eye movements as a possible confounding factor by replicating the RT advantage for targets on the figural side of face displays when all trials containing eye movements were eliminated. The results are discussed in terms of ecological influences on attention, and are cast within the framework of Yantis and Jonides's hypothesis that attention is exogenously drawn to the onset of new perceptual objects. We argue that the figural side constitutes an "object" whereas the ground side does not, and that figural cues such as shape familiarity are effective in determining which areas represent objects.

Detection of moving objects from a moving platform in urban scenes

NARCIS (Netherlands)

Haar, F.B. ter; Hollander, R.J.M. den; Dijk, J.

2010-01-01

Moving object detection in urban scenes is important for the guidance of autonomous vehicles, robot navigation, and monitoring. In this paper moving objects are automatically detected using three sequential frames and tracked over a longer period. To this extend we modify the plane+parallax,

Improving Dorsal Stream Function in Dyslexics by Training Figure/Ground Motion Discrimination Improves Attention, Reading Fluency, and Working Memory.

Science.gov (United States)

Lawton, Teri

2016-01-01

There is an ongoing debate about whether the cause of dyslexia is based on linguistic, auditory, or visual timing deficits. To investigate this issue three interventions were compared in 58 dyslexics in second grade (7 years on average), two targeting the temporal dynamics (timing) of either the auditory or visual pathways with a third reading intervention (control group) targeting linguistic word building. Visual pathway training in dyslexics to improve direction-discrimination of moving test patterns relative to a stationary background (figure/ground discrimination) significantly improved attention, reading fluency, both speed and comprehension, phonological processing, and both auditory and visual working memory relative to controls, whereas auditory training to improve phonological processing did not improve these academic skills significantly more than found for controls. This study supports the hypothesis that faulty timing in synchronizing the activity of magnocellular with parvocellular visual pathways is a fundamental cause of dyslexia, and argues against the assumption that reading deficiencies in dyslexia are caused by phonological deficits. This study demonstrates that visual movement direction-discrimination can be used to not only detect dyslexia early, but also for its successful treatment, so that reading problems do not prevent children from readily learning.

Targets with thin ferromagnetic layers for transient field experiments

International Nuclear Information System (INIS)

Gallant, J.L.; Dmytrenko, P.

1982-01-01

Multilayer targets containing a central layer sufficiently thin so that all recoil nuclei can traverse it and subsequently stop in a suitable cubic environment have been prepared. Such targets are required in experiments making use of a magnetic field acting on an ion moving through a ferromagnetic material. The preparation and annealing of the ferromagnetic foils (iron and gadolinium) and the fabrication of the multilayer targets are described. (orig.)

Multi-Model Estimation Based Moving Object Detection for Aerial Video

Directory of Open Access Journals (Sweden)

Yanning Zhang

2015-04-01

Full Text Available With the wide development of UAV (Unmanned Aerial Vehicle technology, moving target detection for aerial video has become a popular research topic in the computer field. Most of the existing methods are under the registration-detection framework and can only deal with simple background scenes. They tend to go wrong in the complex multi background scenarios, such as viaducts, buildings and trees. In this paper, we break through the single background constraint and perceive the complex scene accurately by automatic estimation of multiple background models. First, we segment the scene into several color blocks and estimate the dense optical flow. Then, we calculate an affine transformation model for each block with large area and merge the consistent models. Finally, we calculate subordinate degree to multi-background models pixel to pixel for all small area blocks. Moving objects are segmented by means of energy optimization method solved via Graph Cuts. The extensive experimental results on public aerial videos show that, due to multi background models estimation, analyzing each pixel’s subordinate relationship to multi models by energy minimization, our method can effectively remove buildings, trees and other false alarms and detect moving objects correctly.

Identification of moving vehicle forces on bridge structures via moving average Tikhonov regularization

Science.gov (United States)

Pan, Chu-Dong; Yu, Ling; Liu, Huan-Lin

2017-08-01

Traffic-induced moving force identification (MFI) is a typical inverse problem in the field of bridge structural health monitoring. Lots of regularization-based methods have been proposed for MFI. However, the MFI accuracy obtained from the existing methods is low when the moving forces enter into and exit a bridge deck due to low sensitivity of structural responses to the forces at these zones. To overcome this shortcoming, a novel moving average Tikhonov regularization method is proposed for MFI by combining with the moving average concepts. Firstly, the bridge-vehicle interaction moving force is assumed as a discrete finite signal with stable average value (DFS-SAV). Secondly, the reasonable signal feature of DFS-SAV is quantified and introduced for improving the penalty function (∣∣x∣∣2 2) defined in the classical Tikhonov regularization. Then, a feasible two-step strategy is proposed for selecting regularization parameter and balance coefficient defined in the improved penalty function. Finally, both numerical simulations on a simply-supported beam and laboratory experiments on a hollow tube beam are performed for assessing the accuracy and the feasibility of the proposed method. The illustrated results show that the moving forces can be accurately identified with a strong robustness. Some related issues, such as selection of moving window length, effect of different penalty functions, and effect of different car speeds, are discussed as well.

A parallel spatiotemporal saliency and discriminative online learning method for visual target tracking in aerial videos

Science.gov (United States)

2018-01-01

Visual tracking in aerial videos is a challenging task in computer vision and remote sensing technologies due to appearance variation difficulties. Appearance variations are caused by camera and target motion, low resolution noisy images, scale changes, and pose variations. Various approaches have been proposed to deal with appearance variation difficulties in aerial videos, and amongst these methods, the spatiotemporal saliency detection approach reported promising results in the context of moving target detection. However, it is not accurate for moving target detection when visual tracking is performed under appearance variations. In this study, a visual tracking method is proposed based on spatiotemporal saliency and discriminative online learning methods to deal with appearance variations difficulties. Temporal saliency is used to represent moving target regions, and it was extracted based on the frame difference with Sauvola local adaptive thresholding algorithms. The spatial saliency is used to represent the target appearance details in candidate moving regions. SLIC superpixel segmentation, color, and moment features can be used to compute feature uniqueness and spatial compactness of saliency measurements to detect spatial saliency. It is a time consuming process, which prompted the development of a parallel algorithm to optimize and distribute the saliency detection processes that are loaded into the multi-processors. Spatiotemporal saliency is then obtained by combining the temporal and spatial saliencies to represent moving targets. Finally, a discriminative online learning algorithm was applied to generate a sample model based on spatiotemporal saliency. This sample model is then incrementally updated to detect the target in appearance variation conditions. Experiments conducted on the VIVID dataset demonstrated that the proposed visual tracking method is effective and is computationally efficient compared to state-of-the-art methods. PMID:29438421

Ground-water monitoring at the Hanford Site, January-December 1984

Energy Technology Data Exchange (ETDEWEB)

Cline, C.S.; Rieger, J.T.; Raymond, J.R.

1985-09-01

This program is designed to evaluate existing and potential pathways of exposure to radioactivity and hazardous chemicals from site operations. This document contains an evaluation of data collected during CY 1984. During 1984, 339 monitoring wells were sampled at various times for radioactive and nonradioactive constituents. Two of these constituents, specifically, tritium and nitrate, have been selected for detailed discussion in this report. Tritium and nitrate in the primary plumes originating from the 200 Areas continue to move generally eastward toward the Columbia River in the direction of ground-water flow. The movement within these plumes is indicated by changes in trends within the analytical data from the monitoring wells. No discernible impact on ground water has yet been observed from the start-up of the PUREX plant in December 1983. The shape of the present tritium plume is similar to those described in previous ground-water monitoring reports, although slight changes on the outer edges have been noted. Radiological impacts from two potential pathways for radionuclide transport in ground water to the environment are discussed in this report. The pathways are: (1) human consumption of ground water from onsite wells, and (2) seepage of ground water into the Columbia River. Concentrations of tritium in spring samples that were collected and analyzed in 1983, and in wells sampled adjacent to the Columbia River in 1984 confirmed that constituents in the ground water are entering the river via springs and subsurface flow. The primary areas where radionuclides enter the Columbia River via ground-water flow are the 100-N and 300 Areas and the shoreline adjacent to the Hanford Townsite. 44 refs., 25 figs., 11 tabs.

Ground-penetrating radar observations for estimating the vertical displacement of rotational landslides

OpenAIRE

C. Lissak; O. Maquaire; J.-P. Malet; F. Lavigne; C. Virmoux; C. Gomez; R. Davidson

2014-01-01

The objective of this paper is to demonstrate the applicability of Ground Penetrating Radar (GPR) for monitoring the displacement of slow-moving landslides. GPR data is used to estimate the vertical movement of rotational slides in combination with other surveying techniques. The experimental site is located along the Normandy coast (North East France) here several rotational landslides are continuously affected by a seasonal kinematic pattern (low displacem...

Tracking and Interception of Ground-Based RF Sources Using Autonomous Guided Munitions with Passive Bearings-Only Sensors and Tracking Algorithms

National Research Council Canada - National Science Library

Ezal, Kenan; Agate, Craig

2006-01-01

This paper considers the problem of tracking and intercepting a potentially moving ground-based RF source with an autonomous guided munition that has a passive bearings-only sensor located on its nose...

SEA ICE THICKNESS MEASUREMENT BY GROUND PENETRATING RADAR FOR GROUND TRUTH OF MICROWAVE REMOTE SENSING DATA

Directory of Open Access Journals (Sweden)

M. Matsumoto

2018-04-01

Full Text Available Observation of sea ice thickness is one of key issues to understand regional effect of global warming. One of approaches to monitor sea ice in large area is microwave remote sensing data analysis. However, ground truth must be necessary to discuss the effectivity of this kind of approach. The conventional method to acquire ground truth of ice thickness is drilling ice layer and directly measuring the thickness by a ruler. However, this method is destructive, time-consuming and limited spatial resolution. Although there are several methods to acquire ice thickness in non-destructive way, ground penetrating radar (GPR can be effective solution because it can discriminate snow-ice and ice-sea water interface. In this paper, we carried out GPR measurement in Lake Saroma for relatively large area (200 m by 300 m, approximately aiming to obtain grand truth for remote sensing data. GPR survey was conducted at 5 locations in the area. The direct measurement was also conducted simultaneously in order to calibrate GPR data for thickness estimation and to validate the result. Although GPR Bscan image obtained from 600MHz contains the reflection which may come from a structure under snow, the origin of the reflection is not obvious. Therefore, further analysis and interpretation of the GPR image, such as numerical simulation, additional signal processing and use of 200 MHz antenna, are required to move on thickness estimation.

Signal Processing of Ground Penetrating Radar Using Spectral Estimation Techniques to Estimate the Position of Buried Targets

Directory of Open Access Journals (Sweden)

Shanker Man Shrestha

2003-11-01

Full Text Available Super-resolution is very important for the signal processing of GPR (ground penetration radar to resolve closely buried targets. However, it is not easy to get high resolution as GPR signals are very weak and enveloped by the noise. The MUSIC (multiple signal classification algorithm, which is well known for its super-resolution capacity, has been implemented for signal and image processing of GPR. In addition, conventional spectral estimation technique, FFT (fast Fourier transform, has also been implemented for high-precision receiving signal level. In this paper, we propose CPM (combined processing method, which combines time domain response of MUSIC algorithm and conventional IFFT (inverse fast Fourier transform to obtain a super-resolution and high-precision signal level. In order to support the proposal, detailed simulation was performed analyzing SNR (signal-to-noise ratio. Moreover, a field experiment at a research field and a laboratory experiment at the University of Electro-Communications, Tokyo, were also performed for thorough investigation and supported the proposed method. All the simulation and experimental results are presented.

Concentration Fluctuations in Smoke Plumes Released Near the Ground

DEFF Research Database (Denmark)

Ejsing Jørgensen, Hans; Mikkelsen, Torben; Pécseli, H.L.

2010-01-01

results are tested against these hypotheses. We find strong evidence for a simple scaling of the standard deviation, skewness and kurtosis with the average concentrations at the downwind distances observed in our experiments. Near-ground concentration fluctuations in fixed as well as moving frames...... of references are investigated. The scaling is supported by data from several experimental sites and different atmospheric stability conditions. One conclusion of the study is that relatively accurate estimates for the standard deviation, skewness and kurtosis can be obtained for the concentration fluctuations...

Agricultural Land Use Determines the Trait Composition of Ground Beetle Communities.

Directory of Open Access Journals (Sweden)

Helena I Hanson

Full Text Available In order to improve biological control of agricultural pests, it is fundamental to understand which factors influence the composition of natural enemies in agricultural landscapes. In this study, we aimed to understand how agricultural land use affects a number of different traits in ground beetle communities to better predict potential consequences of land-use change for ecosystem functioning. We studied ground beetles in fields with different agricultural land use ranging from frequently managed sugar beet fields, winter wheat fields to less intensively managed grasslands. The ground beetles were collected in emergence tents that catch individuals overwintering locally in different life stages and with pitfall traps that catch individuals that could have a local origin or may have dispersed into the field. Community weighted mean values for ground beetle traits such as body size, flight ability and feeding preference were estimated for each land-use type and sampling method. In fields with high land-use intensity the average body length of emerging ground beetle communities was lower than in the grasslands while the average body length of actively moving communities did not differ between the land-use types. The proportion of ground beetles with good flight ability or a carnivorous diet was higher in the crop fields as compared to the grasslands. Our study highlights that increasing management intensity reduces the average body size of emerging ground beetles and the proportion of mixed feeders. Our results also suggest that the dispersal ability of ground beetles enables them to compensate for local management intensities.

Agricultural Land Use Determines the Trait Composition of Ground Beetle Communities.

Science.gov (United States)

Hanson, Helena I; Palmu, Erkki; Birkhofer, Klaus; Smith, Henrik G; Hedlund, Katarina

2016-01-01

In order to improve biological control of agricultural pests, it is fundamental to understand which factors influence the composition of natural enemies in agricultural landscapes. In this study, we aimed to understand how agricultural land use affects a number of different traits in ground beetle communities to better predict potential consequences of land-use change for ecosystem functioning. We studied ground beetles in fields with different agricultural land use ranging from frequently managed sugar beet fields, winter wheat fields to less intensively managed grasslands. The ground beetles were collected in emergence tents that catch individuals overwintering locally in different life stages and with pitfall traps that catch individuals that could have a local origin or may have dispersed into the field. Community weighted mean values for ground beetle traits such as body size, flight ability and feeding preference were estimated for each land-use type and sampling method. In fields with high land-use intensity the average body length of emerging ground beetle communities was lower than in the grasslands while the average body length of actively moving communities did not differ between the land-use types. The proportion of ground beetles with good flight ability or a carnivorous diet was higher in the crop fields as compared to the grasslands. Our study highlights that increasing management intensity reduces the average body size of emerging ground beetles and the proportion of mixed feeders. Our results also suggest that the dispersal ability of ground beetles enables them to compensate for local management intensities.

Cooperative motion control for multi-target observation

Energy Technology Data Exchange (ETDEWEB)

Parker, L.E.

1997-08-01

An important issue that arises in the automation of many security, surveillance, and reconnaissance tasks is that of monitoring (or observing) the movements of targets navigating in a bounded area of interest. A key research issue in these problems is that of sensor placement--determining where sensors should be located to maintain the targets in view. In complex applications involving limited-range sensors, the use of multiple sensors dynamically moving over time is required. In this paper, the author investigates the use of a cooperative team of autonomous sensor-based robots for the observation of multiple moving targets. The focus is primarily on developing the distributed control strategies that allow the robot team to attempt to minimize the total time in which targets escape observation by some robot team member in the area of interest. This paper first formalizes the problem and discusses related work. The author then presents a distributed approximate approach to solving this problem that combines low-level multi-robot control with higher-level reasoning control based on the ALLIANCE formalism. The effectiveness of the approach is analyzed by comparing it to three other feasible algorithms for cooperative control, showing the superiority of the approach for a large class of problems.

Cooperative motion control for multi-target observation

International Nuclear Information System (INIS)

Parker, L.E.

1997-01-01

An important issue that arises in the automation of many security, surveillance, and reconnaissance tasks is that of monitoring (or observing) the movements of targets navigating in a bounded area of interest. A key research issue in these problems is that of sensor placement--determining where sensors should be located to maintain the targets in view. In complex applications involving limited-range sensors, the use of multiple sensors dynamically moving over time is required. In this paper, the author investigates the use of a cooperative team of autonomous sensor-based robots for the observation of multiple moving targets. The focus is primarily on developing the distributed control strategies that allow the robot team to attempt to minimize the total time in which targets escape observation by some robot team member in the area of interest. This paper first formalizes the problem and discusses related work. The author then presents a distributed approximate approach to solving this problem that combines low-level multi-robot control with higher-level reasoning control based on the ALLIANCE formalism. The effectiveness of the approach is analyzed by comparing it to three other feasible algorithms for cooperative control, showing the superiority of the approach for a large class of problems

MOVES regional level sensitivity analysis

Science.gov (United States)

2012-01-01

The MOVES Regional Level Sensitivity Analysis was conducted to increase understanding of the operations of the MOVES Model in regional emissions analysis and to highlight the following: : the relative sensitivity of selected MOVES Model input paramet...

Detection algorithm of infrared small target based on improved SUSAN operator

Science.gov (United States)

Liu, Xingmiao; Wang, Shicheng; Zhao, Jing

2010-10-01

The methods of detecting small moving targets in infrared image sequences that contain moving nuisance objects and background noise is analyzed in this paper. A novel infrared small target detection algorithm based on improved SUSAN operator is put forward. The algorithm selects double templates for the infrared small target detection: one size is greater than the small target point size and another size is equal to the small target point size. First, the algorithm uses the big template to calculate the USAN of each pixel in the image and detect the small target, the edge of the image and isolated noise pixels; Then the algorithm uses the another template to calculate the USAN of pixels detected in the first step and improves the principles of SUSAN algorithm based on the characteristics of the small target so that the algorithm can only detect small targets and don't sensitive to the edge pixels of the image and isolated noise pixels. So the interference of the edge of the image and isolate noise points are removed and the candidate target points can be identified; At last, the target is detected by utilizing the continuity and consistency of target movement. The experimental results indicate that the improved SUSAN detection algorithm can quickly and effectively detect the infrared small targets.

High performance ground penetrating radar survey of TA-49/Area 2. Final report

International Nuclear Information System (INIS)

Hoeberling, R.F.; Rangel, M.J. III

1994-09-01

The results of high performance ground penetrating radar study of Area 2 at Technical Area 49 are presented. The survey was commissioned as part of Los Alamos Laboratory's continuing Environmental Remediation program and was completed and analyzed before borehole studies in Area 2 were started. Based upon the ground penetrating radar results, the location of one of the planned boreholes was moved to assure the drilling area was as safe as possible. While earlier attempts to use commercial radar devices at this facility had not been successful, the radar and digital processing system developed at Los Alamos were able to significantly improve the buried physical detail of the site

Scaling earthquake ground motions for performance-based assessment of buildings

Science.gov (United States)

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

2011-01-01

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

Moving Field Guides

Science.gov (United States)

Cassie Meador; Mark Twery; Meagan. Leatherbury

2011-01-01

The Moving Field Guides (MFG) project is a creative take on site interpretation. Moving Field Guides provide an example of how scientific and artistic endeavors work in parallel. Both begin with keen observations that produce information that must be analyzed, understood, and interpreted. That interpretation then needs to be communicated to others to complete the...

Nanostructure sensor of presence and concentration of a target molecule

Science.gov (United States)

Schipper, John F. (Inventor)

2009-01-01

Method and system (i) to determine when a selected target molecule is present or absent in a fluid, (2) to estimate concentration of the target molecule in the fluid and (3) estimate possible presence of a second (different) target molecule in the fluid, by analyzing differences in resonant frequencies of vibration of a thin beam suspended in the fluid, after the fluid has moved across the beam.

Large Cancer Drug Trial Helps Move Precision Medicine Toward the Mainstream | Poster

Science.gov (United States)

A landmark cancer drug trial is helping set the stage for moving precision medicine into the mainstream of clinical practice, according to a new study. The study, reported in the Journal of Molecular Diagnostics, validates a procedure used in the drug trial that identifies the unique genetic mutations in a patient’s tumor, which is then used as the basis for selecting targeted

Solid hydrogen target for laser driven proton acceleration

Science.gov (United States)

Perin, J. P.; Garcia, S.; Chatain, D.; Margarone, D.

2015-05-01

The development of very high power lasers opens up new horizons in various fields, such as laser plasma acceleration in Physics and innovative approaches for proton therapy in Medicine. Laser driven proton acceleration is commonly based on the so-called Target Normal Sheath Acceleration (TNSA) mechanisms: a high power laser is focused onto a solid target (thin metallic or plastic foil) and interact with matter at very high intensity, thus generating a plasma; as a consequence "hot" electrons are produced and move into the forward direction through the target. Protons are generated at the target rear side, electrons try to escape from the target and an ultra-strong quasi-electrostatic field (~1TV/m) is generated. Such a field can accelerate protons with a wide energy spectrum (1-200 MeV) in a few tens of micrometers. The proton beam characteristics depend on the laser parameters and on the target geometry and nature. This technique has been validated experimentally in several high power laser facilities by accelerating protons coming from hydrogenated contaminant (mainly water) at the rear of metallic target, however, several research groups are investigating the possibility to perform experiments by using "pure" hydrogen targets. In this context, the low temperature laboratory at CEA-Grenoble has developed a cryostat able to continuously produce a thin hydrogen ribbon (from 40 to 100 microns thick). A new extrusion concept, without any moving part has been carried out, using only the thermodynamic properties of the fluid. First results and perspectives are presented in this paper.

Research on the algorithm of infrared target detection based on the frame difference and background subtraction method

Science.gov (United States)

Liu, Yun; Zhao, Yuejin; Liu, Ming; Dong, Liquan; Hui, Mei; Liu, Xiaohua; Wu, Yijian

2015-09-01

As an important branch of infrared imaging technology, infrared target tracking and detection has a very important scientific value and a wide range of applications in both military and civilian areas. For the infrared image which is characterized by low SNR and serious disturbance of background noise, an innovative and effective target detection algorithm is proposed in this paper, according to the correlation of moving target frame-to-frame and the irrelevance of noise in sequential images based on OpenCV. Firstly, since the temporal differencing and background subtraction are very complementary, we use a combined detection method of frame difference and background subtraction which is based on adaptive background updating. Results indicate that it is simple and can extract the foreground moving target from the video sequence stably. For the background updating mechanism continuously updating each pixel, we can detect the infrared moving target more accurately. It paves the way for eventually realizing real-time infrared target detection and tracking, when transplanting the algorithms on OpenCV to the DSP platform. Afterwards, we use the optimal thresholding arithmetic to segment image. It transforms the gray images to black-white images in order to provide a better condition for the image sequences detection. Finally, according to the relevance of moving objects between different frames and mathematical morphology processing, we can eliminate noise, decrease the area, and smooth region boundaries. Experimental results proves that our algorithm precisely achieve the purpose of rapid detection of small infrared target.

Using Simulated Ground Motions to Constrain Near-Source Ground Motion Prediction Equations in Areas Experiencing Induced Seismicity

Science.gov (United States)

Bydlon, S. A.; Dunham, E. M.

2016-12-01

Recent increases in seismic activity in historically quiescent areas such as Oklahoma, Texas, and Arkansas, including large, potentially induced events such as the 2011 Mw 5.6 Prague, OK, earthquake, have spurred the need for investigation into expected ground motions associated with these seismic sources. The neoteric nature of this seismicity increase corresponds to a scarcity of ground motion recordings within 50 km of earthquakes Mw 3.0 and greater, with increasing scarcity at larger magnitudes. Gathering additional near-source ground motion data will help better constraints on regional ground motion prediction equations (GMPEs) and will happen over time, but this leaves open the possibility of damaging earthquakes occurring before potential ground shaking and seismic hazard in these areas are properly understood. To aid the effort of constraining near-source GMPEs associated with induced seismicity, we integrate synthetic ground motion data from simulated earthquakes into the process. Using the dynamic rupture and seismic wave propagation code waveqlab3d, we perform verification and validation exercises intended to establish confidence in simulated ground motions for use in constraining GMPEs. We verify the accuracy of our ground motion simulator by performing the PEER/SCEC layer-over-halfspace comparison problem LOH.1 Validation exercises to ensure that we are synthesizing realistic ground motion data include comparisons to recorded ground motions for specific earthquakes in target areas of Oklahoma between Mw 3.0 and 4.0. Using a 3D velocity structure that includes a 1D structure with additional small-scale heterogeneity, the properties of which are based on well-log data from Oklahoma, we perform ground motion simulations of small (Mw 3.0 - 4.0) earthquakes using point moment tensor sources. We use the resulting synthetic ground motion data to develop GMPEs for small earthquakes in Oklahoma. Preliminary results indicate that ground motions can be amplified

Relational grounding facilitates development of scientifically useful multiscale models

Directory of Open Access Journals (Sweden)

Lam Tai

2011-09-01

Full Text Available Abstract We review grounding issues that influence the scientific usefulness of any biomedical multiscale model (MSM. Groundings are the collection of units, dimensions, and/or objects to which a variable or model constituent refers. To date, models that primarily use continuous mathematics rely heavily on absolute grounding, whereas those that primarily use discrete software paradigms (e.g., object-oriented, agent-based, actor typically employ relational grounding. We review grounding issues and identify strategies to address them. We maintain that grounding issues should be addressed at the start of any MSM project and should be reevaluated throughout the model development process. We make the following points. Grounding decisions influence model flexibility, adaptability, and thus reusability. Grounding choices should be influenced by measures, uncertainty, system information, and the nature of available validation data. Absolute grounding complicates the process of combining models to form larger models unless all are grounded absolutely. Relational grounding facilitates referent knowledge embodiment within computational mechanisms but requires separate model-to-referent mappings. Absolute grounding can simplify integration by forcing common units and, hence, a common integration target, but context change may require model reengineering. Relational grounding enables synthesis of large, composite (multi-module models that can be robust to context changes. Because biological components have varying degrees of autonomy, corresponding components in MSMs need to do the same. Relational grounding facilitates achieving such autonomy. Biomimetic analogues designed to facilitate translational research and development must have long lifecycles. Exploring mechanisms of normal-to-disease transition requires model components that are grounded relationally. Multi-paradigm modeling requires both hyperspatial and relational grounding.

Unmanned Ground Vehicle for Autonomous Non-Destructive Testing of FRP Bridge Decks

Science.gov (United States)

Klinkhachorn, P.; Mercer, A. Scott; Halabe, Udaya B.; GangaRao, Hota V. S.

2007-03-01

Current non-destructive techniques for defect analysis of FRP bridge decks have a narrow scope. These techniques are very good at detecting certain types of defects but are not robust enough to detect all defects by themselves. For example, infrared thermography (IRT) can detect air filled defects and Ground Penetrating Radar (GPR) is good at detecting water filled ones. These technologies can be combined to create a more robust defect detection scheme. To accomplish this, an Unmanned Ground Vehicle (UGV) has been designed that incorporates both IR and GPR analysis to create a comprehensive defect map of a bridge deck. The UGV autonomously surveys the deck surface and acquires data. The UGV has two 1.5 GHz ground coupled GPR antennas that are mounted on the front of the UGV to collect GPR data. It also incorporates an active heating source and a radiometric IR camera to capture IR images of the deck, even in less than ideal weather scenarios such as cold cloudy days. The UGV is designed so that it can collect data in an assembly line fashion. It moves in 1 foot increments. When moving, it collects GPR data from the two antennas. When it stops it heats a section of the deck. The next time it stops to heat a section, the IR camera is analyzing the preheated deck section while preparing for the next section. Because the data is being continually collected using this method, the UGV can survey the entire deck in an efficient and timely manner.

CFD simulation of pesticide spray from air-assisted sprayers in an apple orchard: Tree deposition and off-target losses

Science.gov (United States)

Hong, Se-Woon; Zhao, Lingying; Zhu, Heping

2018-02-01

The ultimate goal of a pesticide spraying system is to provide adequate coverage on intended canopies with a minimum amount of spray materials and off-target waste. Better spray coverage requires an understanding of the fate and transport of spray droplets carried by turbulent airflows in orchards. In this study, an integrated computational fluid dynamics (CFD) model was developed to predict displacement of pesticide spray droplets discharged from an air-assisted sprayer, depositions onto tree canopies, and off-target deposition and airborne drift in an apple orchard. Pesticide droplets discharged from a moving sprayer were tracked using the Lagrangian particle transport model, and the deposition model was applied to droplets entering porous canopy zones. Measurements of the droplet deposition and drift in the same orchard were used to validate the model simulations. Good agreement was found between the measured and simulated spray concentrations inside tree canopies and off-target losses (ground deposition and airborne drifts) with the overall relative errors of 22.1% and 40.6%, respectively, under three growth stages. The CFD model was able to estimate the mass balance of pesticide droplets in the orchard, which was practically difficult to investigate by measurements in field conditions. As the foliage of trees became denser, spray deposition inside canopies increased from 8.5% to 65.8% and airborne drift and ground deposition decreased from 25.8% to 7.0% and 47.8% to 21.2%, respectively. Higher wind speed also increased the spray airborne drift downwind of the orchard. This study demonstrates that CFD model can be used to evaluate spray application performance and design and operate sprayers with increased spray efficiencies and reduced drift potentials.

Data fusion for target tracking and classification with wireless sensor network

Science.gov (United States)

Pannetier, Benjamin; Doumerc, Robin; Moras, Julien; Dezert, Jean; Canevet, Loic

2016-10-01

In this paper, we address the problem of multiple ground target tracking and classification with information obtained from a unattended wireless sensor network. A multiple target tracking (MTT) algorithm, taking into account road and vegetation information, is proposed based on a centralized architecture. One of the key issue is how to adapt classical MTT approach to satisfy embedded processing. Based on track statistics, the classification algorithm uses estimated location, velocity and acceleration to help to classify targets. The algorithms enables tracking human and vehicles driving both on and off road. We integrate road or trail width and vegetation cover, as constraints in target motion models to improve performance of tracking under constraint with classification fusion. Our algorithm also presents different dynamic models, to palliate the maneuvers of targets. The tracking and classification algorithms are integrated into an operational platform (the fusion node). In order to handle realistic ground target tracking scenarios, we use an autonomous smart computer deposited in the surveillance area. After the calibration step of the heterogeneous sensor network, our system is able to handle real data from a wireless ground sensor network. The performance of system is evaluated in a real exercise for intelligence operation ("hunter hunt" scenario).

Search efficiency of biased migration towards stationary or moving targets in heterogeneously structured environments

Science.gov (United States)

Azimzade, Youness; Mashaghi, Alireza

2017-12-01

Efficient search acts as a strong selective force in biological systems ranging from cellular populations to predator-prey systems. The search processes commonly involve finding a stationary or mobile target within a heterogeneously structured environment where obstacles limit migration. An open generic question is whether random or directionally biased motions or a combination of both provide an optimal search efficiency and how that depends on the motility and density of targets and obstacles. To address this question, we develop a simple model that involves a random walker searching for its targets in a heterogeneous medium of bond percolation square lattice and used mean first passage time (〈T 〉 ) as an indication of average search time. Our analysis reveals a dual effect of directional bias on the minimum value of 〈T 〉 . For a homogeneous medium, directionality always decreases 〈T 〉 and a pure directional migration (a ballistic motion) serves as the optimized strategy, while for a heterogeneous environment, we find that the optimized strategy involves a combination of directed and random migrations. The relative contribution of these modes is determined by the density of obstacles and motility of targets. Existence of randomness and motility of targets add to the efficiency of search. Our study reveals generic and simple rules that govern search efficiency. Our findings might find application in a number of areas including immunology, cell biology, ecology, and robotics.

Ground ice and hydrothermal ground motions on aufeis plots of river valleys

Directory of Open Access Journals (Sweden)

V. R. Alekseev

2015-01-01

Full Text Available Localized groundwater outflow and layered freezing of them in forms of large ice clusters on the surface creates specific conditions for energy and mass exchange in the «atmosphere–soil–lithosphere» system. In winter, the soil temperature profile is essentially deformed due to heat emission by the aufeis layer of water at its freezing that forms a specific thermocline layer. Deformation of the temperature profile, gradually decreasing, moves down the cross-section and disappearing at the interface between frozen and thawed rocks. Magnitude and number of the temperature deviations from a «normal» state depends on the heat storage of the aufeis-forming waters and on the number of outflows at a given point. The thermocline formation changes conditions of freezing for underlying ground layers together with mechanism of ice saturation of them, and that results in formation of two-layer ice-ground complexes (IGC which differ drastically from cryogenic features in adjacent parts of the valley. Analysis of genetic characteristics and relation of components of the surface and subsurface layers allowed identification of seven types of the aufeis IGC: massive-segregation, cement-basal, layered-segregation, basal-segregation, vacuum-filtration, pressureinjection, and fissure-vein. Yearly formation and destruction of aufeises and subsurface ices is accompanied by a sequence of particularly hazardous geodynamical phenomena, among which the most important are winter flooding of territories, layered freezing of water, ground heaving, thermokarst, and thermoerosion. Combination of these processes may cause a rapid (often unexpected reconfiguration of channels of both surface and subsurface runoff, abrupt uplifts and subsidences of the surface, and decompaction and «shaking-up» of seasonally thawing and seasonally freezing rocks, which may create exceptionally unfavorable conditions for construction and operation of engineering structures. Aufeis plots

Design of a covert RFID tag network for target discovery and target information routing.

Science.gov (United States)

Pan, Qihe; Narayanan, Ram M

2011-01-01

Radio frequency identification (RFID) tags are small electronic devices working in the radio frequency range. They use wireless radio communications to automatically identify objects or people without the need for line-of-sight or contact, and are widely used in inventory tracking, object location, environmental monitoring. This paper presents a design of a covert RFID tag network for target discovery and target information routing. In the design, a static or very slowly moving target in the field of RFID tags transmits a distinct pseudo-noise signal, and the RFID tags in the network collect the target information and route it to the command center. A map of each RFID tag's location is saved at command center, which can determine where a RFID tag is located based on each RFID tag's ID. We propose the target information collection method with target association and clustering, and we also propose the information routing algorithm within the RFID tag network. The design and operation of the proposed algorithms are illustrated through examples. Simulation results demonstrate the effectiveness of the design.

Millimeter wave radar system on a rotating platform for combined search and track functionality with SAR imaging

Science.gov (United States)

Aulenbacher, Uwe; Rech, Klaus; Sedlmeier, Johannes; Pratisto, Hans; Wellig, Peter

2014-10-01

Ground based millimeter wave radar sensors offer the potential for a weather-independent automatic ground surveillance at day and night, e.g. for camp protection applications. The basic principle and the experimental verification of a radar system concept is described, which by means of an extreme off-axis positioning of the antenna(s) combines azimuthal mechanical beam steering with the formation of a circular-arc shaped synthetic aperture (SA). In automatic ground surveillance the function of search and detection of moving ground targets is performed by means of the conventional mechanical scan mode. The rotated antenna structure designed as a small array with two or more RX antenna elements with simultaneous receiver chains allows to instantaneous track multiple moving targets (monopulse principle). The simultaneously operated SAR mode yields areal images of the distribution of stationary scatterers. For ground surveillance application this SAR mode is best suited for identifying possible threats by means of change detection. The feasibility of this concept was tested by means of an experimental radar system comprising of a 94 GHz (W band) FM-CW module with 1 GHz bandwidth and two RX antennas with parallel receiver channels, placed off-axis at a rotating platform. SAR mode and search/track mode were tested during an outdoor measurement campaign. The scenery of two persons walking along a road and partially through forest served as test for the capability to track multiple moving targets. For SAR mode verification an image of the area composed of roads, grassland, woodland and several man-made objects was reconstructed from the measured data.

Modal-pushover-based ground-motion scaling procedure

Science.gov (United States)

Kalkan, Erol; Chopra, Anil K.

2011-01-01

Earthquake engineering is increasingly using nonlinear response history analysis (RHA) to demonstrate the performance of structures. This rigorous method of analysis requires selection and scaling of ground motions appropriate to design hazard levels. This paper presents a modal-pushover-based scaling (MPS) procedure to scale ground motions for use in a nonlinear RHA of buildings. In the MPS method, the ground motions are scaled to match to a specified tolerance, a target value of the inelastic deformation of the first-mode inelastic single-degree-of-freedom (SDF) system whose properties are determined by the first-mode pushover analysis. Appropriate for first-mode dominated structures, this approach is extended for structures with significant contributions of higher modes by considering elastic deformation of second-mode SDF systems in selecting a subset of the scaled ground motions. Based on results presented for three actual buildings-4, 6, and 13-story-the accuracy and efficiency of the MPS procedure are established and its superiority over the ASCE/SEI 7-05 scaling procedure is demonstrated.

TFTR grounding scheme and ground-monitor system

International Nuclear Information System (INIS)

Viola, M.

1983-01-01

The Tokamak Fusion Test Reactor (TFTR) grounding system utilizes a single-point ground. It is located directly under the machine, at the basement floor level, and is tied to the building perimeter ground. Wired to this single-point ground, via individual 500 MCM insulated cables, are: the vacuum vessel; four toroidal field coil cases/inner support structure quadrants; umbrella structure halves; the substructure ring girder; radial beams and columns; and the diagnostic systems. Prior to the first machine operation, a ground-loop removal program was initiated. It required insulation of all hangers and supports (within a 35-foot radius of the center of the machine) of the various piping, conduits, cable trays, and ventilation systems. A special ground-monitor system was designed and installed. It actively monitors each of the individual machine grounds to insure that there are no inadvertent ground loops within the machine structure or its ground and that the machine grounds are intact prior to each pulse. The TFTR grounding system has proven to be a very manageable system and one that is easy to maintain

77 FR 13656 - Call for Papers: National Symposium on Moving Target Research

Science.gov (United States)

2012-03-07

... a dynamic attack surface to an adversary, increasing the work factor necessary to successfully attack and exploit a cyber target. Throughout the federal government, research related to MT has been... improvement in the defense of cyber systems (a game changer),'' including how to develop better measures of...

The LOFT Ground Segment

DEFF Research Database (Denmark)

Bozzo, E.; Antonelli, A.; Argan, A.

2014-01-01

targets per orbit (~90 minutes), providing roughly ~80 GB of proprietary data per day (the proprietary period will be 12 months). The WFM continuously monitors about 1/3 of the sky at a time and provides data for about ~100 sources a day, resulting in a total of ~20 GB of additional telemetry. The LOFT...... Burst alert System additionally identifies on-board bright impulsive events (e.g., Gamma-ray Bursts, GRBs) and broadcasts the corresponding position and trigger time to the ground using a dedicated system of ~15 VHF receivers. All WFM data are planned to be made public immediately. In this contribution...... we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book 1 . We describe the expected GS contributions from ESA and the LOFT consortium. A review is provided of the planned LOFT data products and the details of the data flow, archiving...

Moving toroidal limiter

International Nuclear Information System (INIS)

Ikuta, Kazunari; Miyahara, Akira.

1983-06-01

The concept of the limiter-divertor proposed by Mirnov is extended to a toroidal limiter-divertor (which we call moving toroidal limiter) using the stream of ferromagnetic balls coated with a low Z materials such as plastics, graphite and ceramics. An important advantage of the use of the ferromagnetic materials would be possible soft landing of the balls on a catcher, provided that the temperature of the balls is below Curie point. Moreover, moving toroidal limiter would work as a protector of the first wall not only against the vertical movement of plasma ring but also against the violent inward motion driven by major disruption because the orbit of the ball in the case of moving toroidal limiter distributes over the small major radius side of the toroidal plasma. (author)

Real-time non-rigid target tracking for ultrasound-guided clinical interventions

NARCIS (Netherlands)

Zachiu, Cornel; Ries, Mario G; Ramaekers, Pascal; Guey, Jean-Luc; Moonen, Chrit T W; de Senneville, Baudouin Denis

2017-01-01

Biological motion is a problem for non- or mini-invasive interventions when conducted in mobile/deformable organs due to the targeted pathology moving/deforming with the organ. This may lead to high miss rates and/or incomplete treatment of the pathology. Therefore, real-time tracking of the target

A new method of small target detection based on neural network

Science.gov (United States)

Hu, Jing; Hu, Yongli; Lu, Xinxin

2018-02-01

The detection and tracking of moving dim target in infrared image have been an research hotspot for many years. The target in each frame of images only occupies several pixels without any shape and structure information. Moreover, infrared small target is often submerged in complicated background with low signal-to-clutter ratio, making the detection very difficult. Different backgrounds exhibit different statistical properties, making it becomes extremely complex to detect the target. If the threshold segmentation is not reasonable, there may be more noise points in the final detection, which is unfavorable for the detection of the trajectory of the target. Single-frame target detection may not be able to obtain the desired target and cause high false alarm rate. We believe the combination of suspicious target detection spatially in each frame and temporal association for target tracking will increase reliability of tracking dim target. The detection of dim target is mainly divided into two parts, In the first part, we adopt bilateral filtering method in background suppression, after the threshold segmentation, the suspicious target in each frame are extracted, then we use LSTM(long short term memory) neural network to predict coordinates of target of the next frame. It is a brand-new method base on the movement characteristic of the target in sequence images which could respond to the changes in the relationship between past and future values of the values. Simulation results demonstrate proposed algorithm can effectively predict the trajectory of the moving small target and work efficiently and robustly with low false alarm.

Harnessing Wind Power in Moving Reference Frames with Application to Vehicles

Science.gov (United States)

Goushcha, Oleg; Felicissimo, Robert; Danesh-Yazdi, Amir; Andreopoulos, Yiannis

2017-11-01

The extraction of wind power from unique configurations embedded in moving vehicles by using micro-turbine devices has been investigated. In such moving environments, the specific power of the air motion is much greater and less intermittent than in stationary wind turbines anchored to the ground in open atmospheric conditions. In a translational frame of reference, the rate of work done by the drag force acting on the wind harnessing device due the relative motion of air should be taken into account in the overall performance evaluation through an energy balance. A device with a venting tube has been tested that connects a high-pressure stagnating flow region in the front of the vehicle with a low-pressure region at its rear. Our analysis identified two key areas to focus on for potentially significant rewards: (1) Vehicles with high energy conversion efficiency which require a high mass flow rate through the venting duct, and (2) low efficiency vehicles with wakes, which will be globally affected by the introduction of the venting duct device in a manner that reduces their drag so that there is a net gain in power generation.

40 CFR 265 interim-status ground-water monitoring plan for the 2101-M pond

International Nuclear Information System (INIS)

Chamness, M.A.; Luttrell, S.P.; Dudziak, S.

1989-03-01

This report outlines a ground-water monitoring plan for the 2101-M pond, located in the southwestern part of the 200-East Area on the Hanford Site in south-central Washington State. It has been determined that hazardous materials may have been discharged to the pond. Installation of an interim-status ground-water monitoring system is required under the Resource Conservation and Recovery Act to determine if hazardous chemicals are moving out of the pond. This plan describes the location of new wells for the monitoring system, how the wells are to be completed, the data to be collected, and how those data can be used to determine the source and extent of any ground-water contamination from the 2101-M pond. Four new wells are planned, one upgradient and three downgradient. 35 refs., 12 figs., 9 tabs

Aerial surveillance based on hierarchical object classification for ground target detection

Science.gov (United States)

Vázquez-Cervantes, Alberto; García-Huerta, Juan-Manuel; Hernández-Díaz, Teresa; Soto-Cajiga, J. A.; Jiménez-Hernández, Hugo

2015-03-01

Unmanned aerial vehicles have turned important in surveillance application due to the flexibility and ability to inspect and displace in different regions of interest. The instrumentation and autonomy of these vehicles have been increased; i.e. the camera sensor is now integrated. Mounted cameras allow flexibility to monitor several regions of interest, displacing and changing the camera view. A well common task performed by this kind of vehicles correspond to object localization and tracking. This work presents a hierarchical novel algorithm to detect and locate objects. The algorithm is based on a detection-by-example approach; this is, the target evidence is provided at the beginning of the vehicle's route. Afterwards, the vehicle inspects the scenario, detecting all similar objects through UTM-GPS coordinate references. Detection process consists on a sampling information process of the target object. Sampling process encode in a hierarchical tree with different sampling's densities. Coding space correspond to a huge binary space dimension. Properties such as independence and associative operators are defined in this space to construct a relation between the target object and a set of selected features. Different densities of sampling are used to discriminate from general to particular features that correspond to the target. The hierarchy is used as a way to adapt the complexity of the algorithm due to optimized battery duty cycle of the aerial device. Finally, this approach is tested in several outdoors scenarios, proving that the hierarchical algorithm works efficiently under several conditions.

Moving Matters: The Causal Effect of Moving Schools on Student Performance. Working Paper #01-15

Science.gov (United States)

Schwartz, Amy Ellen; Stiefel, Leanna; Cordes, Sarah A.

2015-01-01

The majority of existing research on mobility indicates that students do worse in the year of a school move. This research, however, has been unsuccessful in isolating the causal effects of mobility and often fails to distinguish the heterogeneous impacts of moves, conflating structural moves (mandated by a school's terminal grade) and…

Imaging moving objects from multiply scattered waves and multiple sensors

International Nuclear Information System (INIS)

Miranda, Analee; Cheney, Margaret

2013-01-01

In this paper, we develop a linearized imaging theory that combines the spatial, temporal and spectral components of multiply scattered waves as they scatter from moving objects. In particular, we consider the case of multiple fixed sensors transmitting and receiving information from multiply scattered waves. We use a priori information about the multipath background. We use a simple model for multiple scattering, namely scattering from a fixed, perfectly reflecting (mirror) plane. We base our image reconstruction and velocity estimation technique on a modification of a filtered backprojection method that produces a phase-space image. We plot examples of point-spread functions for different geometries and waveforms, and from these plots, we estimate the resolution in space and velocity. Through this analysis, we are able to identify how the imaging system depends on parameters such as bandwidth and number of sensors. We ultimately show that enhanced phase-space resolution for a distribution of moving and stationary targets in a multipath environment may be achieved using multiple sensors. (paper)

Adaptive Moving Object Tracking Integrating Neural Networks And Intelligent Processing

Science.gov (United States)

Lee, James S. J.; Nguyen, Dziem D.; Lin, C.

1989-03-01

A real-time adaptive scheme is introduced to detect and track moving objects under noisy, dynamic conditions including moving sensors. This approach integrates the adaptiveness and incremental learning characteristics of neural networks with intelligent reasoning and process control. Spatiotemporal filtering is used to detect and analyze motion, exploiting the speed and accuracy of multiresolution processing. A neural network algorithm constitutes the basic computational structure for classification. A recognition and learning controller guides the on-line training of the network, and invokes pattern recognition to determine processing parameters dynamically and to verify detection results. A tracking controller acts as the central control unit, so that tracking goals direct the over-all system. Performance is benchmarked against the Widrow-Hoff algorithm, for target detection scenarios presented in diverse FLIR image sequences. Efficient algorithm design ensures that this recognition and control scheme, implemented in software and commercially available image processing hardware, meets the real-time requirements of tracking applications.

Tracking Target and Spiral Waves

DEFF Research Database (Denmark)

Jensen, Flemming G.; Sporring, Jon; Nielsen, Mads

2002-01-01

A new algorithm for analyzing the evolution of patterns of spiral and target waves in large aspect ratio chemical systems is introduced. The algorithm does not depend on finding the spiral tip but locates the center of the pattern by a new concept, called the spiral focus, which is defined...... by the evolutes of the actual spiral or target wave. With the use of Gaussian smoothing, a robust method is developed that permits the identification of targets and spirals foci independently of the wave profile. Examples of an analysis of long image sequences from experiments with the Belousov......–Zhabotinsky reaction catalyzed by ruthenium-tris-bipyridyl are presented. Moving target and spiral foci are found, and the speed and direction of movement of single as well as double spiral foci are investigated. For the experiments analyzed in this paper it is found that the movement of a focus correlates with foci...

Optimal speeds for walking and running, and walking on a moving walkway.

Science.gov (United States)

Srinivasan, Manoj

2009-06-01

Many aspects of steady human locomotion are thought to be constrained by a tendency to minimize the expenditure of metabolic cost. This paper has three parts related to the theme of energetic optimality: (1) a brief review of energetic optimality in legged locomotion, (2) an examination of the notion of optimal locomotion speed, and (3) an analysis of walking on moving walkways, such as those found in some airports. First, I describe two possible connotations of the term "optimal locomotion speed:" that which minimizes the total metabolic cost per unit distance and that which minimizes the net cost per unit distance (total minus resting cost). Minimizing the total cost per distance gives the maximum range speed and is a much better predictor of the speeds at which people and horses prefer to walk naturally. Minimizing the net cost per distance is equivalent to minimizing the total daily energy intake given an idealized modern lifestyle that requires one to walk a given distance every day--but it is not a good predictor of animals' walking speeds. Next, I critique the notion that there is no energy-optimal speed for running, making use of some recent experiments and a review of past literature. Finally, I consider the problem of predicting the speeds at which people walk on moving walkways--such as those found in some airports. I present two substantially different theories to make predictions. The first theory, minimizing total energy per distance, predicts that for a range of low walkway speeds, the optimal absolute speed of travel will be greater--but the speed relative to the walkway smaller--than the optimal walking speed on stationary ground. At higher walkway speeds, this theory predicts that the person will stand still. The second theory is based on the assumption that the human optimally reconciles the sensory conflict between the forward speed that the eye sees and the walking speed that the legs feel and tries to equate the best estimate of the forward

Activity Level Change Detection for Persistent Surveillance

National Research Council Canada - National Science Library

Liu, F; Bush, L. A

2004-01-01

.... Instead of traditional target tracking, this approach utilizes GMTI data as moving spots on the ground to estimate the level of activities and detect unusual activities such as military deployments...

Earthquake ground-motion in presence of source and medium heterogeneities

KAUST Repository

Vyas, Jagdish Chandra

2017-01-01

This dissertation work investigates the effects of earthquake rupture complexity and heterogeneities in Earth structure on near-field ground-motions. More specifically, we address two key issues in seismology: (1) near-field ground-shaking variability as function of distance and azimuth for unilateral directive ruptures, and (2) impact of rupture complexity and seismic scattering on Mach wave coherence associated with supershear rupture propagation. We examine earthquake ground-motion variability associated with unilateral ruptures based on ground-motion simulations of the MW 7.3 1992 Landers earthquake, eight simplified source models, and a MW 7.8 rupture simulation (ShakeOut) for the San Andreas fault. Our numerical modeling reveals that the ground-shaking variability in near-fault distances (< 20 km) is larger than that given by empirical ground motion prediction equations. In addition, the variability decreases with increasing distance from the source, exhibiting a power-law decay. The high near-field variability can be explained by strong directivity effects whose influence weaken as we move away from the fault. At the same time, the slope of the power-law decay is found to be dominantly controlled by slip heterogeneity. Furthermore, the ground-shaking variability is high in the rupture propagation direction whereas low in the directions perpendicular to it. However, the variability expressed as a function of azimuth is not only sensitive to slip heterogeneity, but also to rupture velocity. To study Mach wave coherence for supershear ruptures, we consider heterogeneities in rupture parameters (variations in slip, rise time and rupture speed) and 3D scattering media having small-scale random heterogeneities. The Mach wave coherence is reduced at near-fault distances (< 10 km) by the source heterogeneities. At the larger distances from the source, medium scattering plays the dominant role in reducing the Mach wave coherence. Combined effect of the source and

Laser ``M'egajoule'' cryogenic target program: from target fabrication to conformation of the deuterium-tritium ice layer

Science.gov (United States)

Collier, Rémy; Durut, Frédéric; Reneaume, Benoît; Chicane, Cédric; Théobald, Marc; Breton, Olivier; Martin, Michel; Fleury, Emmanuel; Vincent-Viry, Olivier; Bachelet, Franck; Jeannot, Laurent; Geoffray, Isabelle; Botrel, Ronan; Dauteuil, Christophe; Hermerel, Cyril; Choux, Alexandre; Bednarczyk, Sophie; Legaie, Olivier

2008-11-01

For the French inertial confinement fusion (ICF) experiments, cryogenic target assemblies (CTAs) for the LMJ program are manufactured and filled at CEA Valduc (Dijon) in the cryogenic targets filling station (IRCC). They will be moved at about 20 K into a transport cryostat for cryogenic targets and will be driven from CEA/Valduc to CEA/CESTA (Bordeaux). Cryogenic targets will then be transferred by several cryogenic grippers on the cryogenic target positioner before shots. The CTA has to meet severe specifications and involves a lot of challenging tasks for its manufacture. To fill CTAs by permeation with deuterium-tritium (DT), the IRCC need to meet strict thermal, mechanical and dimensional specifications. To obtain a good combustion yield, a very homogenous DT ice layer and very smooth roughness at 1.5 K below the DT triple point are also required. This paper deals with the up to date main issues in the different fields of the LMJ cryogenic target program.

Influence of mass-asymmetry and ground state spin on fission fragment angular distributions

International Nuclear Information System (INIS)

Thomas, R.G.; Biswas, D.C.; Saxena, A.; Pant, L.M.; Nayak, B.K.; Vind, R.P.; Sahu, P.K.; Sinha, Shrabani; Choudhury, R.K.

2001-01-01

The strong influence of the target or/and projectile ground state spin on the anomalously large anisotropies of fission fragments produced in the heavy-ion induced fission of actinide targets were reported earlier. Interestingly, all those systems studied were having a mass asymmetry greater than the Businaro-Gallone critical asymmetry and hence the presence of pre-equilibrium fission was unambiguously ruled out. The observed anisotropies were successfully explained using the ECD-K-States model. It is of interest to know the influence of the target/projectile ground state spin on systems having an entrance channel mass asymmetry less than the critical value where pre-equilibrium fission cannot be ignored. With this motivation we performed measurements of fission fragment angular distributions of the 16 O+ 235 U (spin=7/2) system

UAV-guided navigation for ground robot tele-operation in a military reconnaissance environment.

Science.gov (United States)

Chen, Jessie Y C

2010-08-01

A military reconnaissance environment was simulated to examine the performance of ground robotics operators who were instructed to utilise streaming video from an unmanned aerial vehicle (UAV) to navigate his/her ground robot to the locations of the targets. The effects of participants' spatial ability on their performance and workload were also investigated. Results showed that participants' overall performance (speed and accuracy) was better when she/he had access to images from larger UAVs with fixed orientations, compared with other UAV conditions (baseline- no UAV, micro air vehicle and UAV with orbiting views). Participants experienced the highest workload when the UAV was orbiting. Those individuals with higher spatial ability performed significantly better and reported less workload than those with lower spatial ability. The results of the current study will further understanding of ground robot operators' target search performance based on streaming video from UAVs. The results will also facilitate the implementation of ground/air robots in military environments and will be useful to the future military system design and training community.

PARALLEL MOVING MECHANICAL SYSTEMS

Directory of Open Access Journals (Sweden)

Florian Ion Tiberius Petrescu

2014-09-01

Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Moving mechanical systems parallel structures are solid, fast, and accurate. Between parallel systems it is to be noticed Stewart platforms, as the oldest systems, fast, solid and precise. The work outlines a few main elements of Stewart platforms. Begin with the geometry platform, kinematic elements of it, and presented then and a few items of dynamics. Dynamic primary element on it means the determination mechanism kinetic energy of the entire Stewart platforms. It is then in a record tail cinematic mobile by a method dot matrix of rotation. If a structural mottoelement consists of two moving elements which translates relative, drive train and especially dynamic it is more convenient to represent the mottoelement as a single moving components. We have thus seven moving parts (the six motoelements or feet to which is added mobile platform 7 and one fixed.

Shelf life of ground beef patties treated by gamma radiation.

Science.gov (United States)

Roberts, W T; Weese, J O

1998-10-01

The effects of irradiation on microbial populations in ground beef patties vacuum package and irradiated frozen at target doses of 0.0, 1.0, 3.0, 5.0, and 7.0 kGy were determined. Irradiated samples were stored at 4 or -18 degrees C for 42 days, and mesophilic aerobic plate counts (APCs) were periodically determined. Fresh ground beef (initial APC of 10(2) CFU/g) treated with 3.0, 5.0, and 7.0 kGy was acceptable ( 10(7) CFU/g) by day 14 and 21, respectively, whereas patties treated at 5.0 kGy did not spoil until 42 days. The nonirradiated control samples for both batches of ground beef spoiled within 7 days. Microbial counts in ground beef patties stored at -18 degrees C did not change over the 42-day period. Shelf life of ground beef patties stored at 4 degrees C may be extended with gamma radiation, especially at 5.0 and 7.0 kGy. Initial microbial load in ground beef samples was an important shelf life factor.

Prostate cancer screening: and yet it moves!

Directory of Open Access Journals (Sweden)

Maciej Kwiatkowski

2015-06-01

Full Text Available The debate of prostate cancer (PCa screening has been shaped over decades. There is a plethora of articles in the literature supporting as well as declining prostate-specific antigen (PSA screening. Does screening decrease PCa mortality? With the long-term results of the European Randomized Study of Screening for Prostate (ERSPC the answer is clearly YES. It moves! However, in medicine there are no benefits without any harm and thus, screening has to be performed in targeted and smart way-or in other words-in a risk-adapted fashion when compared with the way it was done in the past. Here, we discuss the main findings of the ERSPC trials and provide insights on how the future screening strategies should be implemented.

Development of deformable moving lung phantom to simulate respiratory motion in radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Kim, Jina [Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Lee, Youngkyu [Department of Radiation Oncology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, 137-701, Seoul (Korea, Republic of); Shin, Hunjoo [Department of Radiation Oncology, Inchoen St. Mary' s Hospital College of Medicine, The Catholic University of Korea, Incheon 403-720 (Korea, Republic of); Ji, Sanghoon [Field Robot R& D Group, Korea Institute of Industrial Technology, Ansan 426-910 (Korea, Republic of); Park, Sungkwang [Department of Radiation Oncology, Busan Paik Hospital, Inje University, Busan 614-735 (Korea, Republic of); Kim, Jinyoung [Department of Radiation Oncology, Haeundae Paik Hospital, Inje University, Busan 612-896 (Korea, Republic of); Jang, Hongseok [Department of Radiation Oncology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, 137-701, Seoul (Korea, Republic of); Kang, Youngnam, E-mail: ynkang33@gmail.com [Department of Radiation Oncology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, 137-701, Seoul (Korea, Republic of)

2016-07-01

Radiation treatment requires high accuracy to protect healthy organs and destroy the tumor. However, tumors located near the diaphragm constantly move during treatment. Respiration-gated radiotherapy has significant potential for the improvement of the irradiation of tumor sites affected by respiratory motion, such as lung and liver tumors. To measure and minimize the effects of respiratory motion, a realistic deformable phantom is required for use as a gold standard. The purpose of this study was to develop and study the characteristics of a deformable moving lung (DML) phantom, such as simulation, tissue equivalence, and rate of deformation. The rate of change of the lung volume, target deformation, and respiratory signals were measured in this study; they were accurately measured using a realistic deformable phantom. The measured volume difference was 31%, which closely corresponds to the average difference in human respiration, and the target movement was − 30 to + 32 mm. The measured signals accurately described human respiratory signals. This DML phantom would be useful for the estimation of deformable image registration and in respiration-gated radiotherapy. This study shows that the developed DML phantom can exactly simulate the patient's respiratory signal and it acts as a deformable 4-dimensional simulation of a patient's lung with sufficient volume change.

Development of deformable moving lung phantom to simulate respiratory motion in radiotherapy

International Nuclear Information System (INIS)

Kim, Jina; Lee, Youngkyu; Shin, Hunjoo; Ji, Sanghoon; Park, Sungkwang; Kim, Jinyoung; Jang, Hongseok; Kang, Youngnam

2016-01-01

Radiation treatment requires high accuracy to protect healthy organs and destroy the tumor. However, tumors located near the diaphragm constantly move during treatment. Respiration-gated radiotherapy has significant potential for the improvement of the irradiation of tumor sites affected by respiratory motion, such as lung and liver tumors. To measure and minimize the effects of respiratory motion, a realistic deformable phantom is required for use as a gold standard. The purpose of this study was to develop and study the characteristics of a deformable moving lung (DML) phantom, such as simulation, tissue equivalence, and rate of deformation. The rate of change of the lung volume, target deformation, and respiratory signals were measured in this study; they were accurately measured using a realistic deformable phantom. The measured volume difference was 31%, which closely corresponds to the average difference in human respiration, and the target movement was − 30 to + 32 mm. The measured signals accurately described human respiratory signals. This DML phantom would be useful for the estimation of deformable image registration and in respiration-gated radiotherapy. This study shows that the developed DML phantom can exactly simulate the patient's respiratory signal and it acts as a deformable 4-dimensional simulation of a patient's lung with sufficient volume change.

High Throughput Determination of Plant Height, Ground Cover, and Above-Ground Biomass in Wheat with LiDAR.

Science.gov (United States)

Jimenez-Berni, Jose A; Deery, David M; Rozas-Larraondo, Pablo; Condon, Anthony Tony G; Rebetzke, Greg J; James, Richard A; Bovill, William D; Furbank, Robert T; Sirault, Xavier R R

2018-01-01

Crop improvement efforts are targeting increased above-ground biomass and radiation-use efficiency as drivers for greater yield. Early ground cover and canopy height contribute to biomass production, but manual measurements of these traits, and in particular above-ground biomass, are slow and labor-intensive, more so when made at multiple developmental stages. These constraints limit the ability to capture these data in a temporal fashion, hampering insights that could be gained from multi-dimensional data. Here we demonstrate the capacity of Light Detection and Ranging (LiDAR), mounted on a lightweight, mobile, ground-based platform, for rapid multi-temporal and non-destructive estimation of canopy height, ground cover and above-ground biomass. Field validation of LiDAR measurements is presented. For canopy height, strong relationships with LiDAR ( r 2 of 0.99 and root mean square error of 0.017 m) were obtained. Ground cover was estimated from LiDAR using two methodologies: red reflectance image and canopy height. In contrast to NDVI, LiDAR was not affected by saturation at high ground cover, and the comparison of both LiDAR methodologies showed strong association ( r 2 = 0.92 and slope = 1.02) at ground cover above 0.8. For above-ground biomass, a dedicated field experiment was performed with destructive biomass sampled eight times across different developmental stages. Two methodologies are presented for the estimation of biomass from LiDAR: 3D voxel index (3DVI) and 3D profile index (3DPI). The parameters involved in the calculation of 3DVI and 3DPI were optimized for each sample event from tillering to maturity, as well as generalized for any developmental stage. Individual sample point predictions were strong while predictions across all eight sample events, provided the strongest association with biomass ( r 2 = 0.93 and r 2 = 0.92) for 3DPI and 3DVI, respectively. Given these results, we believe that application of this system will provide new

Straight-Line Target Tracking for Unmanned Surface Vehicles

Directory of Open Access Journals (Sweden)

Morten Breivik

2008-10-01

Full Text Available This paper considers the subject of straight-line target tracking for unmanned surface vehicles (USVs. Target-tracking represents motion control scenarios where no information about the target behavior is known in advance, i.e., the path that the target traverses is not defined apriori. Specifically, this work presents the design of a motion control system which enables an underactuated USV to track a target that moves in a straight line at high speed. The motion control system employs a guidance principle originally developed for interceptor missiles, as well as a novel velocity controller inspired by maneuverability and agility concepts found in fighter aircraft literature. The performance of the suggested design is illustrated through full-scale USV experiments in the Trondheimsfjord.

Designing Grounded Feedback: Criteria for Using Linked Representations to Support Learning of Abstract Symbols

Science.gov (United States)

Wiese, Eliane S.; Koedinger, Kenneth R.

2017-01-01

This paper proposes "grounded feedback" as a way to provide implicit verification when students are working with a novel representation. In grounded feedback, students' responses are in the target, to-be-learned representation, and those responses are reflected in a more-accessible linked representation that is intrinsic to the domain.…

Analysis of Ground Effects on Aerodynamic Characteristics of Aerofoils Using Boundary Layer Approximation

Science.gov (United States)

Takahashi, Yuji; Kikuchi, Masanori; Hirano, Kimitaka

A study of a new high-speed zero-emission transportation “Aerotrain” is being carried out in Tohoku University and the University of Miyazaki. Because the aerotrain utilizes the ground effect, research on the aerofoil section, which can harness the ground effect effectively, is important. The aerotrain moves along a U-shaped guideway, which has a ground and sidewalls, so it has many viscous interference elements. In an analysis of the ground effects on the aerodynamic characteristics of aerofoils, the boundary layers on the aerofoil surface must be considered. At first, velocity distributions on the surfaces of aerofoils in potential flows are computed using the vortex method, then the momentum integration equations of the boundary layer are solved with experimental formulas. This procedure has the following advantages: modifications of the aerofoil section are easy because it is not necessary to make complicated computational grids, boundary layer transition and separation can be predicted using empirical procedures. The aerodynamic characteristics of four types of aerofoil sections are investigated to clarify the relationship between aerofoil sections and ground effects. Computational results are compared with experimental results obtained using a towing wind tunnel to verify computational precisions. In addition, aerofoil characteristics at an actual cruise speed are analyzed.

The Moving image

DEFF Research Database (Denmark)

Hansen, Lennard Højbjerg

2014-01-01

Every day we are presented with bodily expressions in audiovisual media – by anchors, journalists and characters in films for instance. This article explores how body language in the moving image has been and can be approached in a scholarly manner.......Every day we are presented with bodily expressions in audiovisual media – by anchors, journalists and characters in films for instance. This article explores how body language in the moving image has been and can be approached in a scholarly manner....

Moving to Jobs?

OpenAIRE

Dave Maré; Jason Timmins

2003-01-01

This paper examines whether New Zealand residents move from low-growth to high-growth regions, using New Zealand census data from the past three inter-censal periods (covering 1986-2001). We focus on the relationship between employment growth and migration flows to gauge the strength of the relationship and the stability of the relationship over the business cycle. We find that people move to areas of high employment growth, but that the probability of leaving a region is less strongly relate...

Accurate location estimation of moving object In Wireless Sensor network

Directory of Open Access Journals (Sweden)

Vinay Bhaskar Semwal

2011-12-01

Full Text Available One of the central issues in wirless sensor networks is track the location, of moving object which have overhead of saving data, an accurate estimation of the target location of object with energy constraint .We do not have any mechanism which control and maintain data .The wireless communication bandwidth is also very limited. Some field which is using this technique are flood and typhoon detection, forest fire detection, temperature and humidity and ones we have these information use these information back to a central air conditioning and ventilation.In this research paper, we propose protocol based on the prediction and adaptive based algorithm which is using less sensor node reduced by an accurate estimation of the target location. We had shown that our tracking method performs well in terms of energy saving regardless of mobility pattern of the mobile target. We extends the life time of network with less sensor node. Once a new object is detected, a mobile agent will be initiated to track the roaming path of the object.

Autonomous Target Ranging Techniques

DEFF Research Database (Denmark)

Jørgensen, Peter Siegbjørn; Jørgensen, John Leif; Denver, Troelz

2003-01-01

of this telescope, a fast determination of the range to and the motion of the detected targets are important. This is needed in order to prepare the future observation strategy for each target, i.e. when is the closest approach where imaging will be optimal. In order to quickly obtain such a determination two...... ranging strategies are presented. One is an improved laser ranger with an effective range with non-cooperative targets of at least 10,000 km, demonstrated in ground tests. The accuracy of the laser ranging will be approximately 1 m. The laser ranger may furthermore be used for trajectory determination...... of nano-gravity probes, which will perform direct mass measurements of selected targets. The other is triangulation from two spacecraft. For this method it is important to distinguish between detection and tracking range, which will be different for Bering since different instruments are used...

Ground-water activation from the upcoming operation of MI40 beam absorber

International Nuclear Information System (INIS)

Bhat, C.M.; Read, A.L.

1996-09-01

During the course of normal operation, a particle accelerator can produce radionuclides in the adjacent soil and in the beam line elements through the interactions of accelerated particles and/or secondary particles produced in the beam absorbers, targets, and sometimes elsewhere through routine beam losses. The production and concentration of these radionuclides depends on the beam parameters such as energy, intensity, particle type, and target configuration. The radionuclides produced in the soil can potentially migrate to the ground water. Soil activation and migration to the ground water depends on the details of the local hydrogeology. Generally, very few places such as the beam stops, target stations, injection and extraction sectors can have high enough radiation fields to produce radionuclides in the soil outside the enclosures. During the design, construction, or an upgrade in the intensity of existing beams, measures are taken to minimize the production of activated soil. The only leachable radionuclides known to be produced in the Fermilab soil are 3 H, 7 Be , 22 Na, 45 Ca and 54 Mn and it has been determined that only 3 H, and 22 Na, because of their longer half lives and greater leachabilities, may significantly impact ground water resources.In the past, Fermilab has developed and used the Single Resident Well Model (SRWM) to estimate the ground water activation. Recently, the Concentration Model (CM), a more realistic method which depends on the site hydrogeology has been developed to decide the shielding requirements of the high radiation sites, and to calculate the ground water activation and its subsequent migration to the aquifer. In this report, the concentration of radionuclide released to the surface waters and the aquifer around the MI40 beam absorber are calculated. Subsequently, the ultimate limit on the primary proton beam intensity to be aborted on the Main Injector beam absorber is determined

Metabolic Rate and Ground Reaction Force During Motorized and Non-Motorized Treadmill Exercise

Science.gov (United States)

Everett, Meghan E.; Loehr, James A.; DeWitt, John K.; Laughlin, Mitzi; Lee, Stuart M. C.

2010-01-01

PURPOSE: To measure vertical ground reaction force (vGRF) and oxygen consumption (VO2) at several velocities during exercise using a ground-based version of the ISS treadmill in the M and NM modes. METHODS: Subjects (n = 20) walked or ran at 0.89, 1.34, 1.79, 2.24, 2.68, and 3.12 m/s while VO2 and vGRF data were collected. VO2 was measured using open-circuit spirometry (TrueOne 2400, Parvo-Medics). Data were averaged over the last 2 min of each 5-min stage. vGRF was measured in separate 15-s bouts at 125 Hz using custom-fitted pressure-sensing insoles (F-Scan Sport Sensors, Tekscan, Inc). A repeated-measures ANOVA was used to test for differences in VO2 and vGRF between M and NM and across speeds. Significance was set at P < 0.05. RESULTS: Most subjects were unable to exercise for 5 min at treadmill speeds above 1.79 m/s in the NM mode; however, vGRF data were obtained for all subjects at each speed in both modes. VO2 was approx.40% higher during NM than M exercise across treadmill speeds. vGRF increased with treadmill speed but was not different between modes. CONCLUSION: Higher VO2 with no change in vGRF suggests that the additional metabolic cost associated with NM treadmill exercise is accounted for in the horizontal forces required to move the treadmill belt. Although this may limit the exercise duration at faster speeds, high-intensity NM exercise activates the hamstrings and plantarflexors, which are not specifically targeted or well protected by other in-flight countermeasures.

A Terminal Guidance Law Based on Motion Camouflage Strategy of Air-to-Ground Missiles

Directory of Open Access Journals (Sweden)

Chang-sheng Gao

2016-01-01

Full Text Available A guidance law for attacking ground target based on motion camouflage strategy is proposed in this paper. According to the relative position between missile and target, the dual second-order dynamics model is derived. The missile guidance condition is given by analyzing the characteristic of motion camouflage strategy. Then, the terminal guidance law is derived by using the relative motion of missile and target and the guidance condition. In the process of derivation, the three-dimensional guidance law could be designed in a two-dimensional plane and the difficulty of guidance law design is reduced. A two-dimensional guidance law for three-dimensional space is derived by bringing the estimation for target maneuver. Finally, simulation for the proposed guidance law is taken and compared with pure proportional navigation. The simulation results demonstrate that the proposed guidance law can be applied to air-to-ground missiles.

Moving Targets and Biodiversity Offsets for Endangered Species Habitat: Is Lesser Prairie Chicken Habitat a Stock or Flow?

Directory of Open Access Journals (Sweden)

Todd K. BenDor

2014-03-01

Full Text Available The US Fish and Wildlife Service will make an Endangered Species Act listing decision for the lesser prairie chicken (Tympanuchus pallidicinctus; “LPC” in March 2014. Based on the findings of a single, Uzbek antelope study, conservation plans put forth for the LPC propose to modify and re-position habitat in the landscape through a series of temporary preservation/restoration efforts. We argue that for certain species, including the LPC, dynamic habitat offsets represent a dangerous re-interpretation of habitat provision and recovery programs, which have nearly-universally viewed ecosystem offsets (habitat, wetlands, streams, etc. as “stocks” that accumulate characteristics over time. Any effort to create a program of temporary, moving habitat offsets must consider species’ (1 life history characteristics, (2 behavioral tendencies (e.g., avoidance of impacted areas, nesting/breeding site fidelity, and (3 habitat restoration characteristics, including long temporal lags in reoccupation. If misapplied, species recovery programs using temporary, moving habitat risk further population declines.

A method for optical ground station reduce alignment error in satellite-ground quantum experiments

Science.gov (United States)

He, Dong; Wang, Qiang; Zhou, Jian-Wei; Song, Zhi-Jun; Zhong, Dai-Jun; Jiang, Yu; Liu, Wan-Sheng; Huang, Yong-Mei

2018-03-01

A satellite dedicated for quantum science experiments, has been developed and successfully launched from Jiuquan, China, on August 16, 2016. Two new optical ground stations (OGSs) were built to cooperate with the satellite to complete satellite-ground quantum experiments. OGS corrected its pointing direction by satellite trajectory error to coarse tracking system and uplink beacon sight, therefore fine tracking CCD and uplink beacon optical axis alignment accuracy was to ensure that beacon could cover the quantum satellite in all time when it passed the OGSs. Unfortunately, when we tested specifications of the OGSs, due to the coarse tracking optical system was commercial telescopes, the change of position of the target in the coarse CCD was up to 600μrad along with the change of elevation angle. In this paper, a method of reduce alignment error between beacon beam and fine tracking CCD is proposed. Firstly, OGS fitted the curve of target positions in coarse CCD along with the change of elevation angle. Secondly, OGS fitted the curve of hexapod secondary mirror positions along with the change of elevation angle. Thirdly, when tracking satellite, the fine tracking error unloaded on the real-time zero point position of coarse CCD which computed by the firstly calibration data. Simultaneously the positions of the hexapod secondary mirror were adjusted by the secondly calibration data. Finally the experiment result is proposed. Results show that the alignment error is less than 50μrad.

Vertical unstable stability of electrodynamic suspension of high-speed ground transport

International Nuclear Information System (INIS)

Baiko, A.V.; Voevodskii, K.E.; Kochetkov, V.M.

1980-01-01

The problem considered is the vertical oscillation of a superconducting solenoid moving over a conducting sheet in connection with the electrodynamic suspension of high-speed ground transport. The oscillation is considered to be unstable at a sufficiently high speed. The current oscillation in the superconducting solenoid caused by its mechanical oscillation is also investigated. The superconducting properties of a solenoid are found to have a pronounced effect on stability. Both the theory and numerical results are presented. Methods of oscillation damping are also discussed. (author)

Treat-to-target in systemic lupus erythematosus

DEFF Research Database (Denmark)

Mosca, Marta; Boumpas, Dimitrios T; Bruce, Ian N

2013-01-01

on May 8, 2012 to discuss whether a treat-to-target approach could be applied in the treatment of systemic lupus erythematosus (SLE) (T2T/SLE), define a research agenda, and establish a plan for moving forward. In the present paper, observations raised at the meeting and literature data on potential...

Latent heat of traffic moving from rest

Science.gov (United States)

Farzad Ahmadi, S.; Berrier, Austin S.; Doty, William M.; Greer, Pat G.; Habibi, Mohammad; Morgan, Hunter A.; Waterman, Josam H. C.; Abaid, Nicole; Boreyko, Jonathan B.

2017-11-01

Contrary to traditional thinking and driver intuition, here we show that there is no benefit to ground vehicles increasing their packing density at stoppages. By systematically controlling the packing density of vehicles queued at a traffic light on a Smart Road, drone footage revealed that the benefit of an initial increase in displacement for close-packed vehicles is completely offset by the lag time inherent to changing back into a ‘liquid phase’ when flow resumes. This lag is analogous to the thermodynamic concept of the latent heat of fusion, as the ‘temperature’ (kinetic energy) of the vehicles cannot increase until the traffic ‘melts’ into the liquid phase. These findings suggest that in situations where gridlock is not an issue, drivers should not decrease their spacing during stoppages in order to lessen the likelihood of collisions with no loss in flow efficiency. In contrast, motion capture experiments of a line of people walking from rest showed higher flow efficiency with increased packing densities, indicating that the importance of latent heat becomes trivial for slower moving systems.

The two-hole ground state of the Hubbard-Anderson model, approximated by a variational RVB-type wave function

NARCIS (Netherlands)

Traa, M.R.M.J.; Traa, M.R.M.J.; Caspers, W.J.; Caspers, W.J.; Banning, E.J.; Banning, E.J.

1994-01-01

In this paper the Hubbard-Anderson model on a square lattice with two holes is studied. The ground state (GS) is approximated by a variational RVB-type wave function. The holes interact by exchange of a localized spin excitation (SE), which is created or absorbed if a hole moves to a

Minimum Delay Moving Object Detection

KAUST Repository

Lao, Dong

2017-11-09

We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

Minimum Delay Moving Object Detection

KAUST Repository

Lao, Dong

2017-01-08

We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

Minimum Delay Moving Object Detection

KAUST Repository

Lao, Dong; Sundaramoorthi, Ganesh

2017-01-01

We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

Minimum Delay Moving Object Detection

KAUST Repository

Lao, Dong

2017-05-14

This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

Ground-based characterization of Hayabusa2 mission target asteroid 162173 Ryugu: constraining mineralogical composition in preparation for spacecraft operations

Science.gov (United States)

Le Corre, Lucille; Sanchez, Juan A.; Reddy, Vishnu; Takir, Driss; Cloutis, Edward A.; Thirouin, Audrey; Becker, Kris J.; Li, Jian-Yang; Sugita, Seiji; Tatsumi, Eri

2018-03-01

Asteroids that are targets of spacecraft missions are interesting because they present us with an opportunity to validate ground-based spectral observations. One such object is near-Earth asteroid (NEA) (162173) Ryugu, which is the target of the Japanese Space Agency's (JAXA) Hayabusa2 sample return mission. We observed Ryugu using the 3-m NASA Infrared Telescope Facility on Mauna Kea, Hawaii, on 2016 July 13 to constrain the object's surface composition, meteorite analogues, and link to other asteroids in the main belt and NEA populations. We also modelled its photometric properties using archival data. Using the Lommel-Seeliger model we computed the predicted flux for Ryugu at a wide range of viewing geometries as well as albedo quantities such as geometric albedo, phase integral, and spherical Bond albedo. Our computed albedo quantities are consistent with results from Ishiguro et al. Our spectral analysis has found a near-perfect match between our spectrum of Ryugu and those of NEA (85275) 1994 LY and Mars-crossing asteroid (316720) 1998 BE7, suggesting that their surface regoliths have similar composition. We compared Ryugu's spectrum with that of main belt asteroid (302) Clarissa, the largest asteroid in the Clarissa asteroid family, suggested as a possible source of Ryugu by Campins et al. We found that the spectrum of Clarissa shows significant differences with our spectrum of Ryugu, but it is similar to the spectrum obtained by Moskovitz et al. The best possible meteorite analogues for our spectrum of Ryugu are two CM2 carbonaceous chondrites, Mighei and ALH83100.

Six years of aerial and ground monitoring surveys for sudden oak death in California

Science.gov (United States)

Lisa Bell; Jeff Mai; Zachary Heath; Erik Haunreiter; Lisa M. Fischer

2008-01-01

Aerial surveys have been conducted since 2001 to map recent hardwood mortality and consequently target ground visits for detection of Phytophthora ramorum, the pathogen that causes sudden oak death (SOD). Each year the aerial and ground surveys monitored much of California?s forests at risk for SOD resulting in new maps of hardwood mortality,...

30 CFR 56.14107 - Moving machine parts.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Moving machine parts. 56.14107 Section 56.14107... Safety Devices and Maintenance Requirements § 56.14107 Moving machine parts. (a) Moving machine parts... takeup pulleys, flywheels, couplings, shafts, fan blades, and similar moving parts that can cause injury...

Water pressure and ground vibrations induced by water guns at a backwater pond on the Illinois River near Morris, Illinois

Science.gov (United States)

Koebel, Carolyn M.; Egly, Rachel M.

2016-09-27

Three different geophysical sensor types were used to characterize the underwater pressure waves and ground velocities generated by the underwater firing of seismic water guns. These studies evaluated the use of water guns as a tool to alter the movement of Asian carp. Asian carp are aquatic invasive species that threaten to move into the Great Lakes Basin from the Mississippi River Basin. Previous studies have identified a threshold of approximately 5 pounds per square inch (lb/in2) for behavioral modification and for structural limitation of a water gun barrier.Two studies were completed during August 2014 and May 2015 in a backwater pond connected to the Illinois River at a sand and gravel quarry near Morris, Illinois. The August 2014 study evaluated the performance of two 80-cubic-inch (in3) water guns. Data from the 80-in3 water guns showed that the pressure field had the highest pressures and greatest extent of the 5-lb/in2 target value at a depth of 5 feet (ft). The maximum recorded pressure was 13.7 lb/in2, approximately 25 ft from the guns. The produced pressure field took the shape of a north-south-oriented elongated sphere with the 5-lb/in2 target value extending across the entire study area at a depth of 5 ft. Ground velocities were consistent over time, at 0.0067 inches per second (in/s) in the transverse direction, 0.031 in/s in the longitudinal direction, and 0.013 in/s in the vertical direction.The May 2015 study evaluated the performance of one and two 100-in3 water guns. Data from the 100-in3 water guns, fired both individually and simultaneously, showed that the pressure field had the highest pressures and greatest extent of the 5-lb/in2 target value at a depth of 5 ft. The maximum pressure was 57.4 lb/in2, recorded at the underwater blast sensor closest to the water guns (at a horizontal distance of approximately 3 ft), as two guns fired simultaneously. Pressures and extent of the 5-lb/in2 target value decrease above and below this 5-ft depth

Visiting Vehicle Ground Trajectory Tool

Science.gov (United States)

Hamm, Dustin

2013-01-01

The International Space Station (ISS) Visiting Vehicle Group needed a targeting tool for vehicles that rendezvous with the ISS. The Visiting Vehicle Ground Trajectory targeting tool provides the ability to perform both realtime and planning operations for the Visiting Vehicle Group. This tool provides a highly reconfigurable base, which allows the Visiting Vehicle Group to perform their work. The application is composed of a telemetry processing function, a relative motion function, a targeting function, a vector view, and 2D/3D world map type graphics. The software tool provides the ability to plan a rendezvous trajectory for vehicles that visit the ISS. It models these relative trajectories using planned and realtime data from the vehicle. The tool monitors ongoing rendezvous trajectory relative motion, and ensures visiting vehicles stay within agreed corridors. The software provides the ability to update or re-plan a rendezvous to support contingency operations. Adding new parameters and incorporating them into the system was previously not available on-the-fly. If an unanticipated capability wasn't discovered until the vehicle was flying, there was no way to update things.

People on the Move

Science.gov (United States)

Mohan, Audrey

2018-01-01

The purpose of this 2-3 day lesson is to introduce students in Grades 2-4 to the idea that people move around the world for a variety of reasons. In this activity, students explore why people move through class discussion, a guided reading, and interviews. The teacher elicits student ideas using the compelling question (Dimension 1 of the C3…

Techno-economic studies on transportable moving-bed onion irradiator

International Nuclear Information System (INIS)

Krishnamurthy, K.; Sharma, K.S.S.; Deshmukh, V.P.; Bongirwar, D.R.; Nair, K.V.V.; Patil, K.B.

1984-01-01

The paper presents the optimisation studies and the design features of a transportable irradiator evolved to demonstrate the techno-economic advantage of the irradiation process at village level. A brief outline is also given of the computer programme generated and employed to optimise the source-target configuration based on a narrow plane source moving-bed irradiation concept that aimed at achieving a simplified product handling system and cost effective design of the biological shield and controls for the irradiator. The engineering features of the irradiator along with a summary of the analysis of the economics of the application of the process are also given. (author)

Experimental validation of heterogeneity-corrected dose-volume prescription on respiratory-averaged CT images in stereotactic body radiotherapy for moving tumors

International Nuclear Information System (INIS)

Nakamura, Mitsuhiro; Miyabe, Yuki; Matsuo, Yukinori; Kamomae, Takeshi; Nakata, Manabu; Yano, Shinsuke; Sawada, Akira; Mizowaki, Takashi; Hiraoka, Masahiro

2012-01-01

The purpose of this study was to experimentally assess the validity of heterogeneity-corrected dose-volume prescription on respiratory-averaged computed tomography (RACT) images in stereotactic body radiotherapy (SBRT) for moving tumors. Four-dimensional computed tomography (CT) data were acquired while a dynamic anthropomorphic thorax phantom with a solitary target moved. Motion pattern was based on cos (t) with a constant respiration period of 4.0 sec along the longitudinal axis of the CT couch. The extent of motion (A 1 ) was set in the range of 0.0–12.0 mm at 3.0-mm intervals. Treatment planning with the heterogeneity-corrected dose-volume prescription was designed on RACT images. A new commercially available Monte Carlo algorithm of well-commissioned 6-MV photon beam was used for dose calculation. Dosimetric effects of intrafractional tumor motion were then investigated experimentally under the same conditions as 4D CT simulation using the dynamic anthropomorphic thorax phantom, films, and an ionization chamber. The passing rate of γ index was 98.18%, with the criteria of 3 mm/3%. The dose error between the planned and the measured isocenter dose in moving condition was within ± 0.7%. From the dose area histograms on the film, the mean ± standard deviation of the dose covering 100% of the cross section of the target was 102.32 ± 1.20% (range, 100.59–103.49%). By contrast, the irradiated areas receiving more than 95% dose for A 1 = 12 mm were 1.46 and 1.33 times larger than those for A 1 = 0 mm in the coronal and sagittal planes, respectively. This phantom study demonstrated that the cross section of the target received 100% dose under moving conditions in both the coronal and sagittal planes, suggesting that the heterogeneity-corrected dose-volume prescription on RACT images is acceptable in SBRT for moving tumors.

Moving and Being Moved: Implications for Practice.

Science.gov (United States)

Kretchmar, R. Scott

2000-01-01

Uses philosophical writings, a novel about baseball, and a nonfiction work on rowing to analyze levels of meaning in physical activity, showing why three popular methods for enhancing meaning have not succeeded and may have moved some students away from deeper levels of meaning. The paper suggests that using hints taken from the three books could…

Automatic measurement of target crossing speed

Science.gov (United States)

Wardell, Mark; Lougheed, James H.

1992-11-01

The motion of ground vehicle targets after a ballistic round is launched can be a major source of inaccuracy for small (handheld) anti-armour weapon systems. A method of automatically measuring the crossing component to compensate the fire control solution has been devised and tested against various targets in a range of environments. A photodetector array aligned with the sight's horizontal reticle obtains scene features, which are digitized and processed to separate target from sight motion. Relative motion of the target against the background is briefly monitored to deduce angular crossing rate and a compensating lead angle is introduced into the aim point. Research to gather quantitative data and optimize algorithm performance is described, and some results from field testing are presented.

Representation of bidirectional ground motions for design spectra in building codes

Science.gov (United States)

Stewart, Jonathan P.; Abrahamson, Norman A.; Atkinson, Gail M.; Beker, Jack W.; Boore, David M.; Bozorgnia, Yousef; Campbell, Kenneth W.; Comartin, Craig D.; Idriss, I.M.; Lew, Marshall; Mehrain, Michael; Moehle, Jack P.; Naeim, Farzad; Sabol, Thomas A.

2011-01-01

The 2009 NEHRP Provisions modified the definition of horizontal ground motion from the geometric mean of spectral accelerations for two components to the peak response of a single lumped mass oscillator regardless of direction. These maximum-direction (MD) ground motions operate under the assumption that the dynamic properties of the structure (e.g., stiffness, strength) are identical in all directions. This assumption may be true for some in-plan symmetric structures, however, the response of most structures is dominated by modes of vibration along specific axes (e.g., longitudinal and transverse axes in a building), and often the dynamic properties (especially stiffness) along those axes are distinct. In order to achieve structural designs consistent with the collapse risk level given in the NEHRP documents, we argue that design spectra should be compatible with expected levels of ground motion along those principal response axes. The use of MD ground motions effectively assumes that the azimuth of maximum ground motion coincides with the directions of principal structural response. Because this is unlikely, design ground motions have lower probability of occurrence than intended, with significant societal costs. We recommend adjustments to make design ground motions compatible with target risk levels.

Detection of shallow buried objects using an autoregressive model on the ground penetrating radar signal

Science.gov (United States)

Nabelek, Daniel P.; Ho, K. C.

2013-06-01

The detection of shallow buried low-metal content objects using ground penetrating radar (GPR) is a challenging task. This is because these targets are right underneath the ground and the ground bounce reflection interferes with their detections. They do not create distinctive hyperbolic signatures as required by most existing GPR detection algorithms due to their special geometric shapes and low metal content. This paper proposes the use of the Autoregressive (AR) modeling method for the detection of these targets. We fit an A-scan of the GPR data to an AR model. It is found that the fitting error will be small when such a target is present and large when it is absent. The ratio of the energy in an Ascan before and after AR model fitting is used as the confidence value for detection. We also apply AR model fitting over scans and utilize the fitting residual energies over several scans to form a feature vector for improving the detections. Using the data collected from a government test site, the proposed method can improve the detection of this kind of targets by 30% compared to the pre-screener, at a false alarm rate of 0.002/m2.

Rearrangement moves on rooted phylogenetic networks.

Science.gov (United States)

Gambette, Philippe; van Iersel, Leo; Jones, Mark; Lafond, Manuel; Pardi, Fabio; Scornavacca, Celine

2017-08-01

Phylogenetic tree reconstruction is usually done by local search heuristics that explore the space of the possible tree topologies via simple rearrangements of their structure. Tree rearrangement heuristics have been used in combination with practically all optimization criteria in use, from maximum likelihood and parsimony to distance-based principles, and in a Bayesian context. Their basic components are rearrangement moves that specify all possible ways of generating alternative phylogenies from a given one, and whose fundamental property is to be able to transform, by repeated application, any phylogeny into any other phylogeny. Despite their long tradition in tree-based phylogenetics, very little research has gone into studying similar rearrangement operations for phylogenetic network-that is, phylogenies explicitly representing scenarios that include reticulate events such as hybridization, horizontal gene transfer, population admixture, and recombination. To fill this gap, we propose "horizontal" moves that ensure that every network of a certain complexity can be reached from any other network of the same complexity, and "vertical" moves that ensure reachability between networks of different complexities. When applied to phylogenetic trees, our horizontal moves-named rNNI and rSPR-reduce to the best-known moves on rooted phylogenetic trees, nearest-neighbor interchange and rooted subtree pruning and regrafting. Besides a number of reachability results-separating the contributions of horizontal and vertical moves-we prove that rNNI moves are local versions of rSPR moves, and provide bounds on the sizes of the rNNI neighborhoods. The paper focuses on the most biologically meaningful versions of phylogenetic networks, where edges are oriented and reticulation events clearly identified. Moreover, our rearrangement moves are robust to the fact that networks with higher complexity usually allow a better fit with the data. Our goal is to provide a solid basis for

Rearrangement moves on rooted phylogenetic networks.

Directory of Open Access Journals (Sweden)

Philippe Gambette

2017-08-01

Full Text Available Phylogenetic tree reconstruction is usually done by local search heuristics that explore the space of the possible tree topologies via simple rearrangements of their structure. Tree rearrangement heuristics have been used in combination with practically all optimization criteria in use, from maximum likelihood and parsimony to distance-based principles, and in a Bayesian context. Their basic components are rearrangement moves that specify all possible ways of generating alternative phylogenies from a given one, and whose fundamental property is to be able to transform, by repeated application, any phylogeny into any other phylogeny. Despite their long tradition in tree-based phylogenetics, very little research has gone into studying similar rearrangement operations for phylogenetic network-that is, phylogenies explicitly representing scenarios that include reticulate events such as hybridization, horizontal gene transfer, population admixture, and recombination. To fill this gap, we propose "horizontal" moves that ensure that every network of a certain complexity can be reached from any other network of the same complexity, and "vertical" moves that ensure reachability between networks of different complexities. When applied to phylogenetic trees, our horizontal moves-named rNNI and rSPR-reduce to the best-known moves on rooted phylogenetic trees, nearest-neighbor interchange and rooted subtree pruning and regrafting. Besides a number of reachability results-separating the contributions of horizontal and vertical moves-we prove that rNNI moves are local versions of rSPR moves, and provide bounds on the sizes of the rNNI neighborhoods. The paper focuses on the most biologically meaningful versions of phylogenetic networks, where edges are oriented and reticulation events clearly identified. Moreover, our rearrangement moves are robust to the fact that networks with higher complexity usually allow a better fit with the data. Our goal is to provide

Reasons for Moving in Nonmetro Iowa

OpenAIRE

Burke, Sandra Charvat; Edelman, Mark

2007-01-01

This study highlights the experiences of people who have recently moved to or from 19 selected nonmetropolitan counties of Iowa. This report highlights work, family, community, and housing reasons for moving. The purpose is to increase understanding about why people move so community leaders and citizens can develop actionable strategies for attracting and retaining population.

GLRS-R 2-colour retroreflector target design and predicted performance

Science.gov (United States)

Lund, Glenn

1993-01-01

This paper reports on the retroreflector ground-target design for the GLRS-R spaceborne dual-wavelength laser ranging system. The described passive design flows down from the requirements of high station autonomy, high global FOV (up to 60 degrees zenith angle), little or no multiple pulse returns, and adequate optical cross section for most ranging geometries. The proposed solution makes use of 5 hollow cube-corner retroreflectors of which one points to the zenith and the remaining four are inclined from the vertical at uniform azimuthal spacings. The need for fairly large (is approximately 10 cm) retroreflectors is expected (within turbulence limitations) to generate quite narrow diffraction lobes, thus placing non-trivial requirements on the vectorial accuracy of velocity aberration corrections. A good compromise solution is found by appropriately spoiling just one of the retroreflector dihedral angles from 90 degrees, thus generating two symmetrically oriented diffraction lobes in the return beam. The required spoil angles are found to have little dependence on ground target latitude. Various link budget analyses are presented, showing the influence of such factors as point-ahead optimization, turbulence, ranging angle, atmospheric visibility and ground target thermal deformations.

Towards automatic patient positioning and scan planning using continuously moving table MR imaging.

Science.gov (United States)

Koken, Peter; Dries, Sebastian P M; Keupp, Jochen; Bystrov, Daniel; Pekar, Vladimir; Börnert, Peter

2009-10-01

A concept is proposed to simplify patient positioning and scan planning to improve ease of use and workflow in MR. After patient preparation in front of the scanner the operator selects the anatomy of interest by a single push-button action. Subsequently, the patient table is moved automatically into the scanner, while real-time 3D isotropic low-resolution continuously moving table scout scanning is performed using patient-independent MR system settings. With a real-time organ identification process running in parallel and steering the scanner, the target anatomy can be positioned fully automatically in the scanner's sensitive volume. The desired diagnostic examination of the anatomy of interest can be planned and continued immediately using the geometric information derived from the acquired 3D data. The concept was implemented and successfully tested in vivo in 12 healthy volunteers, focusing on the liver as the target anatomy. The positioning accuracy achieved was on the order of several millimeters, which turned out to be sufficient for initial planning purposes. Furthermore, the impact of nonoptimal system settings on the positioning performance, the signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) was investigated. The present work proved the basic concept of the proposed approach as an element of future scan automation. (c) 2009 Wiley-Liss, Inc.

COMPASS polarized target for Drell-Yan

CERN Document Server

Pešek, M

2014-01-01

In the COMPASS Drell–Yan experiment the pion beam with momen tum of 190 GeV/ c and in- tensity up to 10 8 pions/s will interact with transversely polarized proton t arget producing muon pair via Drell–Yan process. The solid-state NH 3 will be polarized by dynamic nuclear polar- ization. Maximum polarization reached during data taking i s expected to be up to 90%. The non-interacting beam and other particles produced inside t he target will be stopped in the hadron absorber after the target. Two target cells, sepparated by a 20 cm gap in between, each 55 cm long and 4 cm in diameter give the target material volume about 691 cm 3 . The target platform needs to be moved by 2.3 m in upstream dire ction from the position used in previous experiments in order to accomodate the absorber. D uring the beam time higher radiation is expected in the area of the control room. Thus a new target r emote control system is needed. The target magnet is undergoing a substantial upgrade. Drell–Yan data taking is expected t...

Communication grounding facility

International Nuclear Information System (INIS)

Lee, Gye Seong

1998-06-01

It is about communication grounding facility, which is made up twelve chapters. It includes general grounding with purpose, materials thermal insulating material, construction of grounding, super strength grounding method, grounding facility with grounding way and building of insulating, switched grounding with No. 1A and LCR, grounding facility of transmission line, wireless facility grounding, grounding facility in wireless base station, grounding of power facility, grounding low-tenton interior power wire, communication facility of railroad, install of arrester in apartment and house, install of arrester on introduction and earth conductivity and measurement with introduction and grounding resistance.

Slow light in moving media

Science.gov (United States)

Leonhardt, U.; Piwnicki, P.

2001-06-01

We review the theory of light propagation in moving media with extremely low group velocity. We intend to clarify the most elementary features of monochromatic slow light in a moving medium and, whenever possible, to give an instructive simplified picture.

Energy deposition in a thin copper target downstream and off-axis of a proton-radiography target

International Nuclear Information System (INIS)

Greene, G.A.; Finfrock, C.C.; Snead, C.L.; Hanson, A.L.; Murray, M.M.

2002-01-01

A series of proton energy-deposition experiments was conducted to measure the energy deposited in a copper target located downstream and off-axis of a high-energy proton-radiography target. The proton/target interactions involved low-intensity bunches of protons at 24 GeV/c onto a spherical target consisting of concentric shells of tungsten and copper. The energy-deposition target was placed at five locations downstream of the proton-radiography target, off-axis of the primary beam transport, and was either unshielded or shielded by 5 or 10 cm of lead. Maximum temperature rises measured in the energy-deposition target due to single bunches of 5x10 10 protons on the proton-radiography target were approximately 20 mK per bunch. The data indicated that the scattered radiation was concentrated close to the primary transport axis of the beam line. The energy deposited in the energy-deposition target was reduced by moving the target radially away from the primary transport axis. Placing lead shielding in front of the target further reduced the energy deposition. The measured temperature rises of the energy-deposition target were empirically correlated with the distance from the source, the number of protons incident on the proton-radiography target, the thickness of the lead shielding, and the angle of the energy-deposition target off-axis of the beam line from the proton-radiography target. The correlation of the experimental data that was developed provides a starting point for the evaluation of the shielding requirements for devices downstream of proton-radiography targets such as superconducting magnets

Ground clutter cancellation in incoherent radars: solutions for EISCAT Svalbard radar

Directory of Open Access Journals (Sweden)

T. Turunen

2000-09-01

Full Text Available Incoherent scatter radars measure ionosphere parameters using modified Thomson scatter from free electrons in the target (see e.g. Hagfors, 1997. The integrated cross section of the ionospheric scatterers is extremely small and the measurements can easily be disturbed by signals returned by unwanted targets. Ground clutter signals, entering via the antenna side lobes, can render measurements at the nearest target ranges totally impossible. The EISCAT Svalbard Radar (ESR, which started measurements in 1996, suffers from severe ground clutter and the ionosphere cannot be measured in any simple manner at ranges less than about 120–150 km, depending on the modulation employed. If the target and clutter signals have different, and clearly identifiable, properties then, in principle, there are always ways to eliminate the clutter. In incoherent scatter measurements, differences in the coherence times of the wanted and unwanted signals can be used for clutter cancellation. The clutter cancellation must be applied to all modulations, usually alternating codes in modern experiments, used for shorter ranges. Excellent results have been obtained at the ESR using a simple pulse-to-pulse clutter subtraction method, but there are also other possibilities.Key words: Radio science (ionospheric physics; signal processing; instruments and techniques

Moving into poverty during childhood is associated with later sleep problems.

Science.gov (United States)

Sivertsen, Børge; Bøe, Tormod; Skogen, Jens Christoffer; Petrie, Keith J; Hysing, Mari

2017-09-01

A social gradient in sleep has been demonstrated across the life span, but previous studies have been cross-sectional and used self-reported socioeconomic status (SES) indicators. Using registry-based data on family income trajectories, the current study examined the association between relative poverty in childhood and subsequent sleep in adolescence. Data on family income during 2004-2010 was obtained from the National Income Registry. Poverty was defined as household income poverty, and analysis of variance and general linear models were used to examine associations between income trajectories and sleep, adjusting for confounders. LCA identified four classes: 'never poor', two classes characterized by moving in or out of poverty, and 'chronically poor'. Compared to the 'never poor' group, adolescents from families in the 'moving into poverty' group displayed worse sleep across most sleep measures, including shorter sleep, lower sleep efficiency, and more nocturnal wake time (but not sleep onset latency). Neither adolescents from families who had moved out of poverty by increasing family income, nor the 'chronically poor' group differed significantly from the reference group. The study found that downward socioeconomic mobility was associated with increased adolescent sleep problems. More studies are required on the mechanisms that may account for the association, to find targeted and effective strategies to prevent short sleep duration in adolescents from families with unstable financial circumstances. Copyright © 2017 Elsevier B.V. All rights reserved.

Nordic Seniors on the Move

DEFF Research Database (Denmark)

”I believe that all people need to move about. Actually, some have difficulties in doing so. They stay in their home neighbourhoods where they’ve grown up and feel safe. I can understand that, but my wife and I, we didn’t want that. We are more open to new ideas.” This anthology is about seniors...... on the move. In seven chapters, Nordic researchers from various disciplines, by means of ethnographic methods, attempt to comprehend the phenomenon of Nordic seniors who move to leisure areas in their own or in other countries. The number of people involved in this kind of migratory movement has grown...... above gives voice to one of these seniors, stressing the necessity of moving. The anthology contributes to the international body of literature about later life migration, specifically representing experiences made by Nordic seniors. As shown here, mobility and migration in later life have implications...

Treat-to-target in systemic lupus erythematosus

DEFF Research Database (Denmark)

Mosca, Marta; Boumpas, Dimitrios T; Bruce, Ian N

2013-01-01

Multiple clinical trials performed over twenty years in the treatment of rheumatoid arthritis (RA) have clearly demonstrated that patients have better outcomes if their disease activity at each time-point for follow-up includes a pre-specified target. A European SLE expert panel met in Zurich...... on May 8, 2012 to discuss whether a treat-to-target approach could be applied in the treatment of systemic lupus erythematosus (SLE) (T2T/SLE), define a research agenda, and establish a plan for moving forward. In the present paper, observations raised at the meeting and literature data on potential...

The Apache Longbow-Hellfire Missile Test at Yuma Proving Ground: Ecological Risk Assessment for Missile Firing

International Nuclear Information System (INIS)

Jones, Daniel Steven; Efroymson, Rebecca Ann; Hargrove, William Walter; Suter, Glenn; Pater, Larry

2008-01-01

A multiple stressor risk assessment was conducted at Yuma Proving Ground, Arizona, as a demonstration of the Military Ecological Risk Assessment Framework. The focus was a testing program at Cibola Range, which involved an Apache Longbow helicopter firing Hellfire missiles at moving targets, M60-A1 tanks. This paper describes the ecological risk assessment for the missile launch and detonation. The primary stressor associated with this activity was sound. Other minor stressors included the detonation impact, shrapnel, and fire. Exposure to desert mule deer (Odocoileus hemionus crooki) was quantified using the Army sound contour program BNOISE2, as well as distances from the explosion to deer. Few effects data were available from related studies. Exposure-response models for the characterization of effects consisted of human 'disturbance' and hearing damage thresholds in units of C-weighted decibels (sound exposure level) and a distance-based No Observed Adverse Effects Level for moose and cannonfire. The risk characterization used a weight-of-evidence approach and concluded that risk to mule deer behavior from the missile firing was likely for a negligible number of deer, but that no risk to mule deer abundance and reproduction is expected

Modelling of Moving Coil Actuators in Fast Switching Valves Suitable for Digital Hydraulic Machines

DEFF Research Database (Denmark)

Nørgård, Christian; Roemer, Daniel Beck; Bech, Michael Møller

2015-01-01

an estimation of the eddy currents generated in the actuator yoke upon current rise, as they may have significant influence on the coil current response. The analytical model facilitates fast simulation of the transient actuator response opposed to the transient electro-magnetic finite element model which......The efficiency of digital hydraulic machines is strongly dependent on the valve switching time. Recently, fast switching have been achieved by using a direct electromagnetic moving coil actuator as the force producing element in fast switching hydraulic valves suitable for digital hydraulic...... machines. Mathematical models of the valve switching, targeted for design optimisation of the moving coil actuator, are developed. A detailed analytical model is derived and presented and its accuracy is evaluated against transient electromagnetic finite element simulations. The model includes...

Adaptive moving mesh methods for simulating one-dimensional groundwater problems with sharp moving fronts

Science.gov (United States)

Huang, W.; Zheng, Lingyun; Zhan, X.

2002-01-01

Accurate modelling of groundwater flow and transport with sharp moving fronts often involves high computational cost, when a fixed/uniform mesh is used. In this paper, we investigate the modelling of groundwater problems using a particular adaptive mesh method called the moving mesh partial differential equation approach. With this approach, the mesh is dynamically relocated through a partial differential equation to capture the evolving sharp fronts with a relatively small number of grid points. The mesh movement and physical system modelling are realized by solving the mesh movement and physical partial differential equations alternately. The method is applied to the modelling of a range of groundwater problems, including advection dominated chemical transport and reaction, non-linear infiltration in soil, and the coupling of density dependent flow and transport. Numerical results demonstrate that sharp moving fronts can be accurately and efficiently captured by the moving mesh approach. Also addressed are important implementation strategies, e.g. the construction of the monitor function based on the interpolation error, control of mesh concentration, and two-layer mesh movement. Copyright ?? 2002 John Wiley and Sons, Ltd.

Ground Pollution Science

International Nuclear Information System (INIS)

Oh, Jong Min; Bae, Jae Geun

1997-08-01

This book deals with ground pollution science and soil science, classification of soil and fundamentals, ground pollution and human, ground pollution and organic matter, ground pollution and city environment, environmental problems of the earth and ground pollution, soil pollution and development of geological features of the ground, ground pollution and landfill of waste, case of measurement of ground pollution.

An Analytic Model for the Success Rate of a Robotic Actuator System in Hitting Random Targets.

Science.gov (United States)

Bradley, Stuart

2015-11-20

Autonomous robotic systems are increasingly being used in a wide range of applications such as precision agriculture, medicine, and the military. These systems have common features which often includes an action by an "actuator" interacting with a target. While simulations and measurements exist for the success rate of hitting targets by some systems, there is a dearth of analytic models which can give insight into, and guidance on optimization, of new robotic systems. The present paper develops a simple model for estimation of the success rate for hitting random targets from a moving platform. The model has two main dimensionless parameters: the ratio of actuator spacing to target diameter; and the ratio of platform distance moved (between actuator "firings") to the target diameter. It is found that regions of parameter space having specified high success are described by simple equations, providing guidance on design. The role of a "cost function" is introduced which, when minimized, provides optimization of design, operating, and risk mitigation costs.

16th International Workshop on Polarized Sources, Targets, and Polarimetry (PSTP 2015)

CERN Document Server

2015-01-01

The Workshop on Polarized Sources, Targets and Polarimetry has been a tradition for more than 20 years, moving between Europe, USA and Japan. The XVIth International Workshop on Polarized Sources, Targets and Polarimetry (PSTP 2015) will take place at the Ruhr-University of Bochum, Germany. The workshop addresses the physics and technological challenges related to polarized gas/solid targets, polarized electron/positron/ion/neutron sources, polarimetry and their applications. will be published in Proceedings of Science

Robotic radiosurgery. Treating tumors that move with respiration

International Nuclear Information System (INIS)

Urschel, Harold C. Jr.; Kresl, John J.; Luketich, James D.; Papiez, Lech; Timmerman, Robert D.; Schulz, Raymond A.

2007-01-01

Addresses in detail all aspects of the use of robotic radiosurgery to treat tumors of the lung, liver, and pancreas Includes full consideration of tumor tracking techniques, dosimetry, radiobiology, and fiducial placement strategies Written by leading experts Includes many high quality illustrations Stereotactic radiosurgery continues to evolve in ways that allow this powerful technology to reach and treat more tumors in more patients. This volume in the Robotic Radiosurgery series is devoted to theory and practice in the emerging field of stereotactic radiosurgery (also called stereotactic body radiation therapy) for extracranial tumors, particularly those that move as patients breathe. The book is divided into six sections. The first three sections address tumor motion due to respiration and tumor tracking techniques; dosimetry, radiobiology, and imaging; and fiducial placement systems. The fourth and fifth sections then discuss in depth the use of robotic radiosurgery to treat lung and abdominal tumors, respectively, and a final section explains emerging concepts and techniques. Within this framework, detailed information is provided on the technology and methodology for delivery of high doses of radiation to moving targets, radiobiological and radiological principles, and the challenges faced by clinicians performing extracranial stereotactic radiosurgery. Furthermore, there are thorough reviews of the general clinical literature on stereotactic radiation treatment of tumors of the lungs, liver, and pancreas, and the latest clinical data from clinicians conducting clinical studies using the CyberKnife registered Robotic Radiosurgery System. Special attention is given to the frameless robotic radiosurgery device known as the CyberKnife, the only image-guided radiosurgery system that utilizes intelligent robotics to track, detect, and correct for changes in tumor position during treatments. Tumors that move with respiration are treated with the CyberKnife using a

Robotic radiosurgery. Treating tumors that move with respiration

Energy Technology Data Exchange (ETDEWEB)

Urschel, Harold C. Jr. [Baylor University Medical Center, Dallas, TX (United States). Chair of Cardiovascular and Thoracic Surgical Research, Education and Clinical Excellence; Kresl, John J. [Arizona Oncology Services at St. Joseph' s Hospital and Medical Center, Phoenix, AZ (United States). Dept. of Radiation Oncology; Luketich, James D. [University of Pittsburgh Medical Center PUH, Pittsburgh, PA (United States). The Heart, Lung and Esophageal Surgery Inst.; Papiez, Lech; Timmerman, Robert D. [University of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Radiation Oncology; Schulz, Raymond A. (eds.)

2007-07-01

Addresses in detail all aspects of the use of robotic radiosurgery to treat tumors of the lung, liver, and pancreas Includes full consideration of tumor tracking techniques, dosimetry, radiobiology, and fiducial placement strategies Written by leading experts Includes many high quality illustrations Stereotactic radiosurgery continues to evolve in ways that allow this powerful technology to reach and treat more tumors in more patients. This volume in the Robotic Radiosurgery series is devoted to theory and practice in the emerging field of stereotactic radiosurgery (also called stereotactic body radiation therapy) for extracranial tumors, particularly those that move as patients breathe. The book is divided into six sections. The first three sections address tumor motion due to respiration and tumor tracking techniques; dosimetry, radiobiology, and imaging; and fiducial placement systems. The fourth and fifth sections then discuss in depth the use of robotic radiosurgery to treat lung and abdominal tumors, respectively, and a final section explains emerging concepts and techniques. Within this framework, detailed information is provided on the technology and methodology for delivery of high doses of radiation to moving targets, radiobiological and radiological principles, and the challenges faced by clinicians performing extracranial stereotactic radiosurgery. Furthermore, there are thorough reviews of the general clinical literature on stereotactic radiation treatment of tumors of the lungs, liver, and pancreas, and the latest clinical data from clinicians conducting clinical studies using the CyberKnife {sup registered} Robotic Radiosurgery System. Special attention is given to the frameless robotic radiosurgery device known as the CyberKnife, the only image-guided radiosurgery system that utilizes intelligent robotics to track, detect, and correct for changes in tumor position during treatments. Tumors that move with respiration are treated with the Cyber

Autonomous target recognition using remotely sensed surface vibration measurements

Science.gov (United States)

Geurts, James; Ruck, Dennis W.; Rogers, Steven K.; Oxley, Mark E.; Barr, Dallas N.

1993-09-01

The remotely measured surface vibration signatures of tactical military ground vehicles are investigated for use in target classification and identification friend or foe (IFF) systems. The use of remote surface vibration sensing by a laser radar reduces the effects of partial occlusion, concealment, and camouflage experienced by automatic target recognition systems using traditional imagery in a tactical battlefield environment. Linear Predictive Coding (LPC) efficiently represents the vibration signatures and nearest neighbor classifiers exploit the LPC feature set using a variety of distortion metrics. Nearest neighbor classifiers achieve an 88 percent classification rate in an eight class problem, representing a classification performance increase of thirty percent from previous efforts. A novel confidence figure of merit is implemented to attain a 100 percent classification rate with less than 60 percent rejection. The high classification rates are achieved on a target set which would pose significant problems to traditional image-based recognition systems. The targets are presented to the sensor in a variety of aspects and engine speeds at a range of 1 kilometer. The classification rates achieved demonstrate the benefits of using remote vibration measurement in a ground IFF system. The signature modeling and classification system can also be used to identify rotary and fixed-wing targets.

An image-free opto-mechanical system for creating virtual environments and imaging neuronal activity in freely moving Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Serge Faumont

Full Text Available Non-invasive recording in untethered animals is arguably the ultimate step in the analysis of neuronal function, but such recordings remain elusive. To address this problem, we devised a system that tracks neuron-sized fluorescent targets in real time. The system can be used to create virtual environments by optogenetic activation of sensory neurons, or to image activity in identified neurons at high magnification. By recording activity in neurons of freely moving C. elegans, we tested the long-standing hypothesis that forward and reverse locomotion are generated by distinct neuronal circuits. Surprisingly, we found motor neurons that are active during both types of locomotion, suggesting a new model of locomotion control in C. elegans. These results emphasize the importance of recording neuronal activity in freely moving animals and significantly expand the potential of imaging techniques by providing a mean to stabilize fluorescent targets.

(DCT-FY08) Target Detection Using Multiple Modality Airborne and Ground Based Sensors

Science.gov (United States)

2013-03-01

resolution SIFT grids in metric-topological SLAM ,” in Proc. of the IEEE Conference on Computer Vision and Pattern Recognition, 2009. [4] M. Bosse and R...single camera SLAM ,” IEEE Trans. Pattern Anal. Mach. Intell., vol. 29, no. 6, pp. 1052–1067, 2007. [7] D. Nister, O. Naroditsky, and J. Bergen...segmentation with ground-based and airborne LIDAR range data,” in Proceedings of the Fourth International Symposium on 3D Data Processing

Improving scanner wafer alignment performance by target optimization

Science.gov (United States)

Leray, Philippe; Jehoul, Christiane; Socha, Robert; Menchtchikov, Boris; Raghunathan, Sudhar; Kent, Eric; Schoonewelle, Hielke; Tinnemans, Patrick; Tuffy, Paul; Belen, Jun; Wise, Rich

2016-03-01

In the process nodes of 10nm and below, the patterning complexity along with the processing and materials required has resulted in a need to optimize alignment targets in order to achieve the required precision, accuracy and throughput performance. Recent industry publications on the metrology target optimization process have shown a move from the expensive and time consuming empirical methodologies, towards a faster computational approach. ASML's Design for Control (D4C) application, which is currently used to optimize YieldStar diffraction based overlay (DBO) metrology targets, has been extended to support the optimization of scanner wafer alignment targets. This allows the necessary process information and design methodology, used for DBO target designs, to be leveraged for the optimization of alignment targets. In this paper, we show how we applied this computational approach to wafer alignment target design. We verify the correlation between predictions and measurements for the key alignment performance metrics and finally show the potential alignment and overlay performance improvements that an optimized alignment target could achieve.

Threshold Differences on Figure and Ground: Gelb and Granit (1923).

Science.gov (United States)

Kinateder, Max; Nelson, Rolf

2017-01-01

In 1923, Gelb and Granit, using a method of adjustment for a small red light, reported a lower threshold for the target when presented on a ground region than on an adjacent figural region. More recent work in perceptual organization has found precisely the opposite-a processing advantage seems to go to items presented on the figure, not the ground. Although Gelb and Granit continue to be cited for their finding, it has not previously been available as an English translation. Understanding their methodology and results is important for integrating early Gestalt theory with more recent investigations.

Threshold Differences on Figure and Ground: Gelb and Granit (1923)

Science.gov (United States)

Kinateder, Max

2017-01-01

In 1923, Gelb and Granit, using a method of adjustment for a small red light, reported a lower threshold for the target when presented on a ground region than on an adjacent figural region. More recent work in perceptual organization has found precisely the opposite—a processing advantage seems to go to items presented on the figure, not the ground. Although Gelb and Granit continue to be cited for their finding, it has not previously been available as an English translation. Understanding their methodology and results is important for integrating early Gestalt theory with more recent investigations. PMID:28286640

Dazzle camouflage, target tracking, and the confusion effect.

Science.gov (United States)

Hogan, Benedict G; Cuthill, Innes C; Scott-Samuel, Nicholas E

2016-01-01

The influence of coloration on the ecology and evolution of moving animals in groups is poorly understood. Animals in groups benefit from the "confusion effect," where predator attack success is reduced with increasing group size or density. This is thought to be due to a sensory bottleneck: an increase in the difficulty of tracking one object among many. Motion dazzle camouflage has been hypothesized to disrupt accurate perception of the trajectory or speed of an object or animal. The current study investigates the suggestion that dazzle camouflage may enhance the confusion effect. Utilizing a computer game style experiment with human predators, we found that when moving in groups, targets with stripes parallel to the targets' direction of motion interact with the confusion effect to a greater degree, and are harder to track, than those with more conventional background matching patterns. The findings represent empirical evidence that some high-contrast patterns may benefit animals in groups. The results also highlight the possibility that orientation and turning may be more relevant in the mechanisms of dazzle camouflage than previously recognized.

The Bering Autonomous Target Detection

DEFF Research Database (Denmark)

Jørgensen, John Leif; Denver, Troelz; Betto, Maurizio

2003-01-01

An autonomous asteroid target detection and tracking method has been developed. The method features near omnidirectionality and focus on high speed operations and completeness of search of the near space rather than the traditional faint object search methods, employed presently at the larger...... telescopes. The method has proven robust in operation and is well suited for use onboard spacecraft. As development target for the method and the associated instrumentation the asteroid research mission Bering has been used. Onboard a spacecraft, the autonomous detection is centered around the fully...... autonomous star tracker the Advanced Stellar Compass (ASC). One feature of this instrument is that potential targets are registered directly in terms of date, right ascension, declination, and intensity, which greatly facilitates both tracking search and registering. Results from ground and inflight tests...

Loss of positional information when tracking multiple moving dots: the role of visual memory.

Science.gov (United States)

Narasimhan, Sathyasri; Tripathy, Srimant P; Barrett, Brendan T

2009-01-01

Pylyshyn, Z.W. and Storm, R.W. (1988) (Tracking multiple independent targets: Evidence for a parallel tracking mechanism. Spatial Vision, 3(3), 179-197) proposed that human observers could simultaneously track up to five dots when presented with an array of dots moving in a random manner. In contrast, Tripathy, S.P., and Barrett, B.T. (2004) (Severe loss of positional information when detecting deviations in multiple trajectories. Journal of Vision, 4(12):4, 1020-1043, http://journalofvision.org/4/14/4/, doi: 10.1167/4.12.4) showed that when a threshold paradigm was employed, observers' ability to track deviations in straight-line trajectories is severely compromised when attending to two or more dots. In this study we present a series of four experiments that investigates the role of attention and visual memory while tracking deviations in multiple trajectories using a threshold paradigm. Our stimuli consisted of several linear, non-parallel, left-to-right trajectories, each moving at the same speed. At the trajectory mid-point (reached simultaneously by all dots), one of the dots (target) deviated clockwise or counter-clockwise. The observers' task was to identify the direction of deviation. The target trajectory was cued in the second half of the trial either by disappearance of distractors at the monitor's mid-line (Experiment 1) or by means of a change in colour of the target (Experiment 2); in both cases deviation thresholds rose steeply when the number of distractor trajectories was increased from 0 (typical threshold approximately 2 degrees) to 3 (typical threshold>20 degrees). When all the trajectories were presented statically in a single frame (Experiment 3), thresholds for identifying the orientation change of the target trajectory remained relatively unchanged as the number of distractor trajectories was increased. When a temporal delay of a few hundred milliseconds was introduced between the first and second halves of trajectories (Experiment 4

The Effect of Predicted Vehicle Displacement on Ground Crew Task Performance and Hardware Design

Science.gov (United States)

Atencio, Laura Ashley; Reynolds, David W.

2011-01-01

NASA continues to explore new launch vehicle concepts that will carry astronauts to low- Earth orbit to replace the soon-to-be retired Space Transportation System (STS) shuttle. A tall vertically stacked launch vehicle (> or =300 ft) is exposed to the natural environment while positioned on the launch pad. Varying directional winds and vortex shedding cause the vehicle to sway in an oscillating motion. Ground crews working high on the tower and inside the vehicle during launch preparations will be subjected to this motion while conducting critical closeout tasks such as mating fluid and electrical connectors and carrying heavy objects. NASA has not experienced performing these tasks in such environments since the Saturn V, which was serviced from a movable (but rigid) service structure; commercial launchers are likewise attended by a service structure that moves away from the vehicle for launch. There is concern that vehicle displacement may hinder ground crew operations, impact the ground system designs, and ultimately affect launch availability. The vehicle sway assessment objective is to replicate predicted frequencies and displacements of these tall vehicles, examine typical ground crew tasks, and provide insight into potential vehicle design considerations and ground crew performance guidelines. This paper outlines the methodology, configurations, and motion testing performed while conducting the vehicle displacement assessment that will be used as a Technical Memorandum for future vertically stacked vehicle designs.

Target Selection Models with Preference Variation Between Offenders

NARCIS (Netherlands)

Townsley, Michael; Birks, Daniel; Ruiter, Stijn; Bernasco, Wim; White, Gentry

2016-01-01

Objectives: This study explores preference variation in location choice strategies of residential burglars. Applying a model of offender target selection that is grounded in assertions of the routine activity approach, rational choice perspective, crime pattern and social disorganization theories,

Illumination compensation in ground based hyperspectral imaging

Science.gov (United States)

Wendel, Alexander; Underwood, James

2017-07-01

Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

Figure-ground assignment in pigeons: evidence for a figural benefit.

Science.gov (United States)

Lazareva, Olga E; Castro, Leyre; Vecera, Shaun P; Wasserman, Edward A

2006-07-01

Four pigeons discriminated whether a target spot appeared on a colored figural shape or on a differently colored background by first pecking the target and then reporting its location: on the figure or the background. We recorded three dependent variables: target detection time, choice response time, and choice accuracy. The birds were faster to detect the target, to report its location, and to learn the correct response on figure trials than on background trials. Later tests suggested that the pigeons might have attended to the figural region as a whole rather than using local properties in performing the figure-background discrimination. The location of the figural region did not affect figure-ground assignment. Finally, when 4 other pigeons had to detect and peck the target without making a choice report, no figural advantage emerged in target detection time, suggesting that the birds' attention may not have been automatically summoned to the figural region.

Trading Fees and Slow-Moving Capital

OpenAIRE

Buss, Adrian; Dumas, Bernard J

2015-01-01

In some situations, investment capital seems to move slowly towards profitable trades. We develop a model of a financial market in which capital moves slowly simply because there is a proportional cost to moving capital. We incorporate trading fees in an infinite-horizon dynamic general-equilibrium model in which investors optimally and endogenously decide when and how much to trade. We determine the steady-state equilibrium no-trade zone, study the dynamics of equilibrium trades and prices a...

Multi-Agent Cooperative Target Search

Directory of Open Access Journals (Sweden)

Jinwen Hu

2014-05-01

Full Text Available This paper addresses a vision-based cooperative search for multiple mobile ground targets by a group of unmanned aerial vehicles (UAVs with limited sensing and communication capabilities. The airborne camera on each UAV has a limited field of view and its target discriminability varies as a function of altitude. First, by dividing the whole surveillance region into cells, a probability map can be formed for each UAV indicating the probability of target existence within each cell. Then, we propose a distributed probability map updating model which includes the fusion of measurement information, information sharing among neighboring agents, information decay and transmission due to environmental changes such as the target movement. Furthermore, we formulate the target search problem as a multi-agent cooperative coverage control problem by optimizing the collective coverage area and the detection performance. The proposed map updating model and the cooperative control scheme are distributed, i.e., assuming that each agent only communicates with its neighbors within its communication range. Finally, the effectiveness of the proposed algorithms is illustrated by simulation.

Beam steering application for W-band data links with moving targets in 5G wireless networks

DEFF Research Database (Denmark)

Morales Vicente, Alvaro; Rodríguez Páez, Juan Sebastián; Gallardo, Omar

2017-01-01

to this problem, RoF (Radio-over-Fiber) architectures have been proposed as low-latency, cost-effective candidates. Two elements are introduced to extend the RoF approach. First, the carrier frequency is raised into the W-band (75–110 GHz) to increase the available capacity. Second, a mechanical beam......-steering solution based on a Stewart platform is adopted for the transmitter antenna to allow it to follow a moving receiver along a known path, thereby enhancing the coverage area. The performance of a system transmitting a 2.5 Gbit/s non-return-to-zero signal generated by photonic up-conversion over a wireless...

Ground effects on the stability of separated flow around an airfoil at low Reynolds numbers

Science.gov (United States)

He, Wei; Yu, Peng; Li, Larry K. B.

2017-11-01

We perform a BiGlobal stability analysis on the separated flow around a NACA 4415 airfoil at low Reynolds numbers (Re = 300 - 1000) and a high angle of attack α =20° with a focus on the effect of the airfoil's proximity to a moving ground. The results show that the most dominant perturbation is the Kelvin-Helmholtz mode and that this traveling mode becomes less unstable as the airfoil approaches the ground, although this stabilizing effect diminishes with increasing Reynolds number. By performing a Floquet analysis, we find that this ground effect can also stabilize secondary instabilities. This numerical-theoretical study shows that the ground can have a significant influence on the stability of separated flow around an airfoil at low Reynolds numbers, which could have implications for the design of micro aerial vehicles and for the understanding of natural flyers such as insects and birds. This work was supported by the Research Grants Council of Hong Kong (Project No. 16235716 and 26202815) and the Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase) under Grant No.U1501501.

Detection technique of targets for missile defense system

Science.gov (United States)

Guo, Hua-ling; Deng, Jia-hao; Cai, Ke-rong

2009-11-01

Ballistic missile defense system (BMDS) is a weapon system for intercepting enemy ballistic missiles. It includes ballistic-missile warning system, target discrimination system, anti-ballistic-missile guidance systems, and command-control communication system. Infrared imaging detection and laser imaging detection are widely used in BMDS for surveillance, target detection, target tracking, and target discrimination. Based on a comprehensive review of the application of target-detection techniques in the missile defense system, including infrared focal plane arrays (IRFPA), ground-based radar detection technology, 3-dimensional imaging laser radar with a photon counting avalanche photodiode (APD) arrays and microchip laser, this paper focuses on the infrared and laser imaging detection techniques in missile defense system, as well as the trends for their future development.

30 CFR 57.14107 - Moving machine parts.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Moving machine parts. 57.14107 Section 57.14107... Equipment Safety Devices and Maintenance Requirements § 57.14107 Moving machine parts. (a) Moving machine parts shall be guarded to protect persons from contacting gears, sprockets, chains, drive, head, tail...

A comparison of directed search target detection versus in-scene target detection in Worldview-2 datasets

Science.gov (United States)

Grossman, S.

2015-05-01

Since the events of September 11, 2001, the intelligence focus has moved from large order-of-battle targets to small targets of opportunity. Additionally, the business community has discovered the use of remotely sensed data to anticipate demand and derive data on their competition. This requires the finer spectral and spatial fidelity now available to recognize those targets. This work hypothesizes that directed searches using calibrated data perform at least as well as inscene manually intensive target detection searches. It uses calibrated Worldview-2 multispectral images with NEF generated signatures and standard detection algorithms to compare bespoke directed search capabilities against ENVI™ in-scene search capabilities. Multiple execution runs are performed at increasing thresholds to generate detection rates. These rates are plotted and statistically analyzed. While individual head-to-head comparison results vary, 88% of the directed searches performed at least as well as in-scene searches with 50% clearly outperforming in-scene methods. The results strongly support the premise that directed searches perform at least as well as comparable in-scene searches.

Lattice Boltzmann methods for moving boundary flows

International Nuclear Information System (INIS)

Inamuro, Takaji

2012-01-01

The lattice Boltzmann methods (LBMs) for moving boundary flows are presented. The LBM for two-phase fluid flows with the same density and the LBM combined with the immersed boundary method are described. In addition, the LBM on a moving multi-block grid is explained. Three numerical examples (a droplet moving in a constricted tube, the lift generation of a flapping wing and the sedimentation of an elliptical cylinder) are shown in order to demonstrate the applicability of the LBMs to moving boundary problems. (invited review)

Lattice Boltzmann methods for moving boundary flows

Energy Technology Data Exchange (ETDEWEB)

Inamuro, Takaji, E-mail: inamuro@kuaero.kyoto-u.ac.jp [Department of Aeronautics and Astronautics, and Advanced Research Institute of Fluid Science and Engineering, Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan)

2012-04-01

The lattice Boltzmann methods (LBMs) for moving boundary flows are presented. The LBM for two-phase fluid flows with the same density and the LBM combined with the immersed boundary method are described. In addition, the LBM on a moving multi-block grid is explained. Three numerical examples (a droplet moving in a constricted tube, the lift generation of a flapping wing and the sedimentation of an elliptical cylinder) are shown in order to demonstrate the applicability of the LBMs to moving boundary problems. (invited review)

Riding Horse Harness (Based on Materials from the Chulkovo Burial Ground

Directory of Open Access Journals (Sweden)

Grishakov Valeriy V.

2013-12-01

Full Text Available The items of riding horse harness (bits with psalia, stirrups, buckles, decorations of bridles are analyzed in the article on the basis of the materials from the Chulkovo (Murom burial ground site of the 8th-10th centuries, located on right bank of the Oka river. It has been established that the use of horse harness items by the Muroma culture population, which had left the Chulkovo burial ground, is in full correspondence with the general traditions of the Finno-Ugric peoples of the Volga river region characteristic of the 8th-10th centuries. The shapes of the bits correspond to both the steppe (bits with S-shaped and straight psalia and the local traditions (bits with two and three moving rings. A tendency to uniformity is observed in the tradition of stirrups production. The main differences of the Muroma burial grounds from the neighboring Mordovian ones consist in the presence of horse burials (not known among the Mordovians, and, on the other hand, in a practically complete lack of horse harness in the funeral set of human burials. It can be assumed that the importance of cavalry with the Muromа was lower than with the Mordovians who were living next to the steppe world.

MQ-1C Gray Eagle Unmanned Aircraft System (MQ-1C Gray Eagle)

Science.gov (United States)

2015-12-01

Range Finder /Laser Designator, Synthetic Aperture Radar/Ground Moving Target Indicator, communications relay, and Hellfire Missiles. Ground equipment...equipment strength . Each Gray Eagle company will consist of 125 soldiers within the Divisional CAB and the NTC. Each unit will have three identical...will bring these companies to full Gray Eagle System equipment strength . Each Gray Eagle company will consist of 125 soldiers within the divisional

Chicks prefer to peck at insect-like elongated stimuli moving in a direction orthogonal to their longer axis.

Science.gov (United States)

Clara, Elena; Regolin, Lucia; Vallortigara, Giorgio; Rogers, Lesley J

2009-11-01

Spontaneous preferences towards possible prey have been little investigated using targets in motion. Preferences of domestic chicks (Gallus gallus) to peck at video-images of stimuli representing live insects moving along their longer body axis (i.e. "forwards") or along the shorter body axis (i.e. "sideways") were investigated. Chicks presented with both types of stimulus displayed a significant preference for pecking at stimuli moving sideways. This preference was already present on day 1 post-hatching, and it strengthened on day 6 for those chicks that had experienced pecking at live insects. Head angles used to fixate the stimuli prior to pecking were also analysed and were consistent (i.e. 30 degrees -35 degrees and 60 degrees -65 degrees ) with those reported for fixation of non-edible targets (larger stimuli at a distance). In a first control experiment the same video-presented stimuli were used but the insect's legs were removed to reduce flickering. In a second control experiment, paper-printed images of the whole insect were used. In both cases, the sideways direction of movement was clearly preferred. Overall, our data show that chicks have a spontaneous preference to peck at video-images resembling live insects moving along their shorter body axis. Sideways movement may constitute a crucial signal attracting chicks' attention and enhancing predatory responses possibly because of stronger stimulation of motion detectors.

H. R. 2253 - the Ground Water Research, Development and Demonstration Act, and H. R. 791 - the National Ground Water Contamination Information Act of 1987. Hearing before the Subcommittee on Natural Resources, Agriculture Research and Environment of the Committee on Science, Space, and Technology, U. S. House of Representatives, First Session, July 21, 1987