Science.gov

Sample records for spatial error concealment

  1. Standard Deviation and Intra Prediction Mode Based Adaptive Spatial Error Concealment (SEC) in H.264/AVC

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Wang, Lei; Ikenaga, Takeshi; Goto, Satoshi

    Transmission of compressed video over error prone channels may result in packet losses or errors, which can significantly degrade the image quality. Therefore an error concealment scheme is applied at the video receiver side to mask the damaged video. Considering there are 3 types of MBs (Macro Blocks) in natural video frame, i. e., Textural MB, Edged MB, and Smooth MB, this paper proposes an adaptive spatial error concealment which can choose 3 different methods for these 3 different MBs. For criteria of choosing appropriate method, 2 factors are taken into consideration. Firstly, standard deviation of our proposed edge statistical model is exploited. Secondly, some new features of latest video compression standard H.264/AVC, i. e., intra prediction mode is also considered for criterion formulation. Compared with previous works, which are only based on deterministic measurement, proposed method achieves the best image recovery. Subjective and objective image quality evaluations in experiments confirmed this.

  2. Embedded wavelet video coding with error concealment

    NASA Astrophysics Data System (ADS)

    Chang, Pao-Chi; Chen, Hsiao-Ching; Lu, Ta-Te

    2000-04-01

    We present an error-concealed embedded wavelet (ECEW) video coding system for transmission over Internet or wireless networks. This system consists of two types of frames: intra (I) frames and inter, or predicted (P), frames. Inter frames are constructed by the residual frames formed by variable block-size multiresolution motion estimation (MRME). Motion vectors are compressed by arithmetic coding. The image data of intra frames and residual frames are coded by error-resilient embedded zerotree wavelet (ER-EZW) coding. The ER-EZW coding partitions the wavelet coefficients into several groups and each group is coded independently. Therefore, the error propagation effect resulting from an error is only confined in a group. In EZW coding any single error may result in a totally undecodable bitstream. To further reduce the error damage, we use the error concealment at the decoding end. In intra frames, the erroneous wavelet coefficients are replaced by neighbors. In inter frames, erroneous blocks of wavelet coefficients are replaced by data from the previous frame. Simulations show that the performance of ECEW is superior to ECEW without error concealment by 7 to approximately 8 dB at the error-rate of 10-3 in intra frames. The improvement still has 2 to approximately 3 dB at a higher error-rate of 10-2 in inter frames.

  3. Adaptive error concealment algorithm for MPEG compressed video

    NASA Astrophysics Data System (ADS)

    Sun, Huifang; Zdepski, Joel

    1992-11-01

    This paper presents an adaptive error concealment technique for MPEG (Moving Picture Experts Group) compressed video. Error concealment algorithms are essential for many practical video transmission scenarios characterized by occasional data loss due to thermal noise, channel impairments, network congestion, etc.. Such scenarios of current importance include terrestrial (simulcast) HDTV, teleconferencing via packet networks, TV/HDTV over fiber-optic ATM (asynchronous transfer mode) systems, etc. In view of the increasing importance of MPEG video for many of these applications, a number of error concealment approaches for MPEG have been developed, and are currently being evaluated in terms of their complexity vs. performance trade-offs. Here, we report the results of recent work on a specific adaptive algorithm that provides excellent robustness properties for MPEG-1 video transmitted on either one- or two-tier transmission media. Receiver error concealment is intended to ameliorate the impact of lost video data by exploiting available redundancy in the decoded picture. The concealment process must be supported by an appropriate transport format which helps to identify the image pixel regions which correspond to lost video data. Once the image region (i.e., macroblocks, slices, etc.) to be concealed are identified, a combination of temporal and spatial replacement techniques may be applied to fill in the lost picture elements. The specific details of the concealment procedure will depend upon the compression algorithm being used, and on the level of algorithmic complexity permissible within the decoder. Simulation results obtained from a detailed end-to-end model that incorporates MPEG compression/decompression and a custom cell-relay (ATM type) transport format are reported briefly.

  4. Video error concealment using block matching and frequency selective extrapolation algorithms

    NASA Astrophysics Data System (ADS)

    P. K., Rajani; Khaparde, Arti

    2017-06-01

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

  5. Efficient block error concealment code for image and video transmission

    NASA Astrophysics Data System (ADS)

    Min, Jungki; Chan, Andrew K.

    1999-05-01

    Image and video compression standards such as JPEG, MPEG, H.263 are highly sensitive to error during transmission. Among typical error propagation mechanisms in video compression schemes, loss of block synchronization produces the worst image degradation. Even an error of a single bit in block synchronization may result in data to be placed in wrong positions that is caused by spatial shifts. Our proposed efficient block error concealment code (EBECC) virtually guarantees block synchronization and it improves coding efficiency by several hundred folds over the error resilient entropy code (EREC), proposed by N. G. Kingsbury and D. W. Redmill, depending on the image format and size. In addition, the EBECC produces slightly better resolution on the reconstructed images or video frames than those from the EREC. Another important advantage of the EBECC is that it does not require redundancy contrasting to the EREC that requires 2-3 percent of redundancy. Our preliminary results show the EBECC is 240 times faster than EREC for encoding and 330 times for decoding based on the CIF format of H.263 video coding standard. The EBECC can be used on most of the popular image and video compression schemes such as JPEG, MPEG, and H.263. Additionally, it is especially useful to wireless networks in which the percentage of image and video data is high.

  6. Content-based retransmission with error concealment for astronomical images

    NASA Astrophysics Data System (ADS)

    Thienphrapa, Paul; Boussalis, Helen; Liu, Charles; Rad, Khosrow; Dong, Jane

    2005-10-01

    The James Webb Space Telescope (JWST) is expected to produce a vast amount of images that are valuable for astronomical research and education. To support research activities related to JWST mission, NASA has provided funds to establish the Structures Pointing and Control Engineering (SPACE) Laboratory at the California State University, Los Angeles (CSULA). One of the research activities in SPACE lab is to design an effective and efficient transmission system to disseminate JWST images across the Internet. This paper presents a prioritized transmission method to provide the best quality of the transferred image based on the joint-optimization of content-based retransmission and error concealment. First, the astronomical image is compressed using a scalable wavelet-based approach, then packetized into independently decodable packets. To facilitate the joint-optimization of two mutually dependent error control methods, a novel content index is declared to represent the significance of the packet content as well as its importance in error concealment. Based on the defined content index, the optimal retransmission schedule is determined to maximize the quality of the received image under delay constraint with the given error concealment method. Experimental results demonstrate that the proposed approach is very effective to combat the packet loss during transmission to achieve a desirable quality of the received astronomical images.

  7. Video inpainting with short-term windows: application to object removal and error concealment.

    PubMed

    Ebdelli, Mounira; Le Meur, Olivier; Guillemot, Christine

    2015-10-01

    In this paper, we propose a new video inpainting method which applies to both static or free-moving camera videos. The method can be used for object removal, error concealment, and background reconstruction applications. To limit the computational time, a frame is inpainted by considering a small number of neighboring pictures which are grouped into a group of pictures (GoP). More specifically, to inpaint a frame, the method starts by aligning all the frames of the GoP. This is achieved by a region-based homography computation method which allows us to strengthen the spatial consistency of aligned frames. Then, from the stack of aligned frames, an energy function based on both spatial and temporal coherency terms is globally minimized. This energy function is efficient enough to provide high quality results even when the number of pictures in the GoP is rather small, e.g. 20 neighboring frames. This drastically reduces the algorithm complexity and makes the approach well suited for near real-time video editing applications as well as for loss concealment applications. Experiments with several challenging video sequences show that the proposed method provides visually pleasing results for object removal, error concealment, and background reconstruction context.

  8. An edge-based temporal error concealment for MPEG-coded video

    NASA Astrophysics Data System (ADS)

    Huang, Yu-Len; Lien, Hsiu-Yi

    2005-07-01

    When transmitted over unreliable channels, the compressed video can suffer severe degradation. Some strategies were employed to make an acceptable quality of the decoded image sequence. Error concealment (EC) technique is one of effective approaches to diminish the quality degradation. A number of EC algorithms have been developed to combat the transmission errors for MPEG-coded video. These methods always work well to reconstruct the smooth or regular damaged macroblocks. However, for damaged macroblocks were irregular or high-detail, the reconstruction may follow noticeable blurring consequence or not match well with the surrounding macroblocks. This paper proposes an edgebased temporal EC model to conceal the errors. In the proposed method, both the spatial and the temporal contextual features in compressed video are measured by using an edge detector, i.e. Sobel operator. The edge information surrounding a damaged macroblock is utilized to estimate the lost motion vectors based on the boundary matching technique. Next, the estimated motion vectors are used to reconstruct the damaged macroblock by exploiting the information in reference frames. In comparison with traditional EC algorithms, the proposed method provides a significant improvement on both objective peak signal-to-noise ratio (PSNR) measurement and subjective visual quality of MPEG-coded video.

  9. A neighbourhood analysis based technique for real-time error concealment in H.264 intra pictures

    NASA Astrophysics Data System (ADS)

    Beesley, Steven T. C.; Grecos, Christos; Edirisinghe, Eran

    2007-02-01

    H.264s extensive use of context-based adaptive binary arithmetic or variable length coding makes streams highly susceptible to channel errors, a common occurrence over networks such as those used by mobile devices. Even a single bit error will cause a decoder to discard all stream data up to the next fixed length resynchronisation point, the worst scenario is that an entire slice is lost. In cases where retransmission and forward error concealment are not possible, a decoder should conceal any erroneous data in order to minimise the impact on the viewer. Stream errors can often be spotted early in the decode cycle of a macroblock which if aborted can provide unused processor cycles, these can instead be used to conceal errors at minimal cost, even as part of a real time system. This paper demonstrates a technique that utilises Sobel convolution kernels to quickly analyse the neighbourhood surrounding erroneous macroblocks before performing a weighted multi-directional interpolation. This generates significantly improved statistical (PSNR) and visual (IEEE structural similarity) results when compared to the commonly used weighted pixel value averaging. Furthermore it is also computationally scalable, both during analysis and concealment, achieving maximum performance from the spare processing power available.

  10. Pixel-level Matching Based Multi-hypothesis Error Concealment Modes for Wireless 3D H.264/MVC Communication

    NASA Astrophysics Data System (ADS)

    El-Shafai, Walid

    2015-09-01

    3D multi-view video (MVV) is multiple video streams shot by several cameras around a single scene simultaneously. Therefore it is an urgent task to achieve high 3D MVV compression to meet future bandwidth constraints while maintaining a high reception quality. 3D MVV coded bit-streams that are transmitted over wireless network can suffer from error propagation in the space, time and view domains. Error concealment (EC) algorithms have the advantage of improving the received 3D video quality without any modifications in the transmission rate or in the encoder hardware or software. To improve the quality of reconstructed 3D MVV, we propose an efficient adaptive EC algorithm with multi-hypothesis modes to conceal the erroneous Macro-Blocks (MBs) of intra-coded and inter-coded frames by exploiting the spatial, temporal and inter-view correlations between frames and views. Our proposed algorithm adapts to 3D MVV motion features and to the error locations. The lost MBs are optimally recovered by utilizing motion and disparity matching between frames and views on pixel-by-pixel matching basis. Our simulation results show that the proposed adaptive multi-hypothesis EC algorithm can significantly improve the objective and subjective 3D MVV quality.

  11. Error resilient framework using one-pass explicit flexible macroblock ordering map generation and error concealment for H.264/AVC wireless video communication

    NASA Astrophysics Data System (ADS)

    Panyavaraporn, Jantana; Aramvith, Supavadee

    2011-04-01

    H.264/AVC is the newest standard for digital video compression developed jointly by ITU-T's Video Coding Experts Group and ISO/IEC's Moving Picture Experts Group. One feature of the new standard is the adoption of a robust error resilience tool at the encoder known as flexible macroblock ordering (FMO). In this paper, we present an algorithm to generate a one-pass FMO map based on spatial and temporal information at the encoder, and an error concealment method at the decoder for wireless video transmission. The error concealment method at the decoder is applied according to the residual information derived from the distortion information obtained at the encoder while the one-pass FMO map is being generated. Our simulation results performed under slow and fast fading channels confirm that the proposed technique can reduce the number of undecodable macroblocks up to 66.79% and 80.54%, respectively, when compared with no FMO. The peak signal-to-noise ratio improvements are up to 2.67 and 1.05 dB, respectively when compared to predefined FMO (Type 1).

  12. Sparsity-based Image Error Concealment via Adaptive Dual Dictionary Learning and Regularization.

    PubMed

    Liu, Xianming; Zhai, Deming; Zhou, Jiantao; Wang, Shiqi; Zhao, Debin; Gao, Huijun

    2016-10-31

    In this paper, we propose a novel sparsity-based image error concealment (EC) algorithm through Adaptive Dual dictionary Learning and Regularization (ADLR). We define two feature spaces: the observed space and the latent space, corresponding to the available regions and the missing regions of image under test, respectively. We learn adaptive and complete dictionaries individually for each space, where the training data are collected via an adaptive template matching mechanism. Based on the piecewise stationarity of natural images, a local correlation model is learned to bridge the sparse representations of the aforementioned dual spaces, allowing us to transfer the knowledge of the available regions to the missing regions for EC purpose. Eventually, the EC task is formulated as a unified optimization problem, where the sparsity of both spaces and the learned correlation model are incorporated. Experimental results show that the proposed method outperforms the state-of-the-art techniques in terms of both objective and perceptual metrics.

  13. Joint source coding, transport processing, and error concealment for H.323-based packet video

    NASA Astrophysics Data System (ADS)

    Zhu, Qin-Fan; Kerofsky, Louis

    1998-12-01

    In this paper, we investigate how to adapt different parameters in H.263 source coding, transport processing and error concealment to optimize end-to-end video quality at different bitrates and packet loss rates for H.323-based packet video. First different intra coding patterns are compared and we show that the contiguous rectangle or square block pattern offers the best performance in terms of video quality in the presence of packet loss. Second, the optimal intra coding frequency is found for different bitrates and packet loss rates. The optimal number of GOB headers to be inserted in the source coding is then determined. The effect of transport processing strategies such as packetization and retransmission is also examined. For packetization, the impact of packet size and the effect of macroblock segmentation to picture quality are investigated. Finally, we show that the dejitter buffering delay can be used to the advantage for packet loss recovery with video retransmission without incurring any extra delay.

  14. Spatial frequency domain error budget

    SciTech Connect

    Hauschildt, H; Krulewich, D

    1998-08-27

    The aim of this paper is to describe a methodology for designing and characterizing machines used to manufacture or inspect parts with spatial-frequency-based specifications. At Lawrence Livermore National Laboratory, one of our responsibilities is to design or select the appropriate machine tools to produce advanced optical and weapons systems. Recently, many of the component tolerances for these systems have been specified in terms of the spatial frequency content of residual errors on the surface. We typically use an error budget as a sensitivity analysis tool to ensure that the parts manufactured by a machine will meet the specified component tolerances. Error budgets provide the formalism whereby we account for all sources of uncertainty in a process, and sum them to arrive at a net prediction of how "precisely" a manufactured component can meet a target specification. Using the error budget, we are able to minimize risk during initial stages by ensuring that the machine will produce components that meet specifications before the machine is actually built or purchased. However, the current error budgeting procedure provides no formal mechanism for designing machines that can produce parts with spatial-frequency-based specifications. The output from the current error budgeting procedure is a single number estimating the net worst case or RMS error on the work piece. This procedure has limited ability to differentiate between low spatial frequency form errors versus high frequency surface finish errors. Therefore the current error budgeting procedure can lead us to reject a machine that is adequate or accept a machine that is inadequate. This paper will describe a new error budgeting methodology to aid in the design and characterization of machines used to manufacture or inspect parts with spatial-frequency-based specifications. The output from this new procedure is the continuous spatial frequency content of errors that result on a machined part. If the machine

  15. Error concealment strategy for picture-header loss in MPEG compressed video

    NASA Astrophysics Data System (ADS)

    Sun, Huifang; Zdepski, Joel

    1994-04-01

    MPEG (Moving Picture Experts Group) video coding standard has emerged to facilitate the fast growth of full-motion compression on digital storage media and digital communication. As new applications arise, the problems of arising of noisy channels need to be solved. Some error resilience techniques have been proposed to address this problem. However, in MPEG compressed video there are some data elements within the picture-header which are absolutely crucial to decoding. Without them no decoding can be accomplished. Previous proposed error resilience techniques can only handle this kind of loss by replacing whole frame with the previously decoded frame. In this paper, an error concealment strategy is proposed for the case of losing picture-header information during transmission of the compressed MPEG bit- stream. This proposal is motivated by the fact that all bits are not equal important within the video bit-stream. The basic idea of this strategy is the use of the redundant picture-header concept which allows redundant transmission of these very sensitive data within the MPEG-2 video headers. This strategy has to be supported by appropriate ATM-type transport structure. The redundant picture header will be assigned to the different cell with the original picture- header to protect the loss of picture-header for the purpose of improving the noise channel performance.

  16. Roundoff error effects on spatial lattice algorithm

    NASA Technical Reports Server (NTRS)

    An, S. H.; Yao, K.

    1986-01-01

    The floating-point roundoff error effect under finite word length limitations is analyzed for the time updates of reflection coefficients in the spatial lattice algorithm. It is shown that recursive computation is superior to direct computation under finite word length limitations. Moreover, the forgetting factor, which is conventionally used to smooth the time variations of the inputs, is also a crucial parameter in the consideration of the system stability and adaptability under finite word length constraints.

  17. Authenticating concealed private data while maintaining concealment

    DOEpatents

    Thomas, Edward V.; Draelos, Timothy J.

    2007-06-26

    A method of and system for authenticating concealed and statistically varying multi-dimensional data comprising: acquiring an initial measurement of an item, wherein the initial measurement is subject to measurement error; applying a transformation to the initial measurement to generate reference template data; acquiring a subsequent measurement of an item, wherein the subsequent measurement is subject to measurement error; applying the transformation to the subsequent measurement; and calculating a Euclidean distance metric between the transformed measurements; wherein the calculated Euclidean distance metric is identical to a Euclidean distance metric between the measurement prior to transformation.

  18. Spatial Error Metrics for Oceanographic Model Verification

    DTIC Science & Technology

    2012-02-01

    quantitatively and qualitatively for this oceano - graphic data and successfully separates the model error into displacement and intensity components. This... oceano - graphic models as well, though one would likely need to make special modifications to handle the often-used nonuniform spacing between depth layers

  19. Spatial Assessment of Model Errors from Four Regression Techniques

    Treesearch

    Lianjun Zhang; Jeffrey H. Gove; Jeffrey H. Gove

    2005-01-01

    Fomst modelers have attempted to account for the spatial autocorrelations among trees in growth and yield models by applying alternative regression techniques such as linear mixed models (LMM), generalized additive models (GAM), and geographicalIy weighted regression (GWR). However, the model errors are commonly assessed using average errors across the entire study...

  20. Spatial sampling errors for a satellite-borne scanning radiometer

    NASA Technical Reports Server (NTRS)

    Manalo, Natividad D.; Smith, G. L.

    1991-01-01

    The Clouds and Earth's Radiant Energy System (CERES) scanning radiometer is planned as the Earth radiation budget instrument for the Earth Observation System, to be flown in the late 1990's. In order to minimize the spatial sampling errors of the measurements, it is necessary to select design parameters for the instrument such that the resulting point spread function will minimize spatial sampling errors. These errors are described as aliasing and blurring errors. Aliasing errors are due to presence in the measurements of spatial frequencies beyond the Nyquist frequency, and blurring errors are due to attenuation of frequencies below the Nyquist frequency. The design parameters include pixel shape and dimensions, sampling rate, scan period, and time constants of the measurements. For a satellite-borne scanning radiometer, the pixel footprint grows quickly at large nadir angles. The aliasing errors thus decrease with increasing scan angle, but the blurring errors grow quickly. The best design minimizes the sum of these two errors over a range of scan angles. Results of a parameter study are presented, showing effects of data rates, pixel dimensions, spacecraft altitude, and distance from the spacecraft track.

  1. Spatial regression with covariate measurement error: A semiparametric approach.

    PubMed

    Huque, Md Hamidul; Bondell, Howard D; Carroll, Raymond J; Ryan, Louise M

    2016-09-01

    Spatial data have become increasingly common in epidemiology and public health research thanks to advances in GIS (Geographic Information Systems) technology. In health research, for example, it is common for epidemiologists to incorporate geographically indexed data into their studies. In practice, however, the spatially defined covariates are often measured with error. Naive estimators of regression coefficients are attenuated if measurement error is ignored. Moreover, the classical measurement error theory is inapplicable in the context of spatial modeling because of the presence of spatial correlation among the observations. We propose a semiparametric regression approach to obtain bias-corrected estimates of regression parameters and derive their large sample properties. We evaluate the performance of the proposed method through simulation studies and illustrate using data on Ischemic Heart Disease (IHD). Both simulation and practical application demonstrate that the proposed method can be effective in practice.

  2. Filtered kriging for spatial data with heterogeneous measurement error variances.

    PubMed

    Christensen, William F

    2011-09-01

    When predicting values for the measurement-error-free component of an observed spatial process, it is generally assumed that the process has a common measurement error variance. However, it is often the case that each measurement in a spatial data set has a known, site-specific measurement error variance, rendering the observed process nonstationary. We present a simple approach for estimating the semivariogram of the unobservable measurement-error-free process using a bias adjustment of the classical semivariogram formula. We then develop a new kriging predictor that filters the measurement errors. For scenarios where each site's measurement error variance is a function of the process of interest, we recommend an approach that also uses a variance-stabilizing transformation. The properties of the heterogeneous variance measurement-error-filtered kriging (HFK) predictor and variance-stabilized HFK predictor, and the improvement of these approaches over standard measurement-error-filtered kriging are demonstrated using simulation. The approach is illustrated with climate model output from the Hudson Strait area in northern Canada. In the illustration, locations with high or low measurement error variances are appropriately down- or upweighted in the prediction of the underlying process, yielding a realistically smooth picture of the phenomenon of interest. © 2011, The International Biometric Society.

  3. Deterministic error correction for nonlocal spatial-polarization hyperentanglement.

    PubMed

    Li, Tao; Wang, Guan-Yu; Deng, Fu-Guo; Long, Gui-Lu

    2016-02-10

    Hyperentanglement is an effective quantum source for quantum communication network due to its high capacity, low loss rate, and its unusual character in teleportation of quantum particle fully. Here we present a deterministic error-correction scheme for nonlocal spatial-polarization hyperentangled photon pairs over collective-noise channels. In our scheme, the spatial-polarization hyperentanglement is first encoded into a spatial-defined time-bin entanglement with identical polarization before it is transmitted over collective-noise channels, which leads to the error rejection of the spatial entanglement during the transmission. The polarization noise affecting the polarization entanglement can be corrected with a proper one-step decoding procedure. The two parties in quantum communication can, in principle, obtain a nonlocal maximally entangled spatial-polarization hyperentanglement in a deterministic way, which makes our protocol more convenient than others in long-distance quantum communication.

  4. Deterministic error correction for nonlocal spatial-polarization hyperentanglement

    NASA Astrophysics Data System (ADS)

    Li, Tao; Wang, Guan-Yu; Deng, Fu-Guo; Long, Gui-Lu

    2016-02-01

    Hyperentanglement is an effective quantum source for quantum communication network due to its high capacity, low loss rate, and its unusual character in teleportation of quantum particle fully. Here we present a deterministic error-correction scheme for nonlocal spatial-polarization hyperentangled photon pairs over collective-noise channels. In our scheme, the spatial-polarization hyperentanglement is first encoded into a spatial-defined time-bin entanglement with identical polarization before it is transmitted over collective-noise channels, which leads to the error rejection of the spatial entanglement during the transmission. The polarization noise affecting the polarization entanglement can be corrected with a proper one-step decoding procedure. The two parties in quantum communication can, in principle, obtain a nonlocal maximally entangled spatial-polarization hyperentanglement in a deterministic way, which makes our protocol more convenient than others in long-distance quantum communication.

  5. Measurement error caused by spatial misalignment in environmental epidemiology.

    PubMed

    Gryparis, Alexandros; Paciorek, Christopher J; Zeka, Ariana; Schwartz, Joel; Coull, Brent A

    2009-04-01

    In many environmental epidemiology studies, the locations and/or times of exposure measurements and health assessments do not match. In such settings, health effects analyses often use the predictions from an exposure model as a covariate in a regression model. Such exposure predictions contain some measurement error as the predicted values do not equal the true exposures. We provide a framework for spatial measurement error modeling, showing that smoothing induces a Berkson-type measurement error with nondiagonal error structure. From this viewpoint, we review the existing approaches to estimation in a linear regression health model, including direct use of the spatial predictions and exposure simulation, and explore some modified approaches, including Bayesian models and out-of-sample regression calibration, motivated by measurement error principles. We then extend this work to the generalized linear model framework for health outcomes. Based on analytical considerations and simulation results, we compare the performance of all these approaches under several spatial models for exposure. Our comparisons underscore several important points. First, exposure simulation can perform very poorly under certain realistic scenarios. Second, the relative performance of the different methods depends on the nature of the underlying exposure surface. Third, traditional measurement error concepts can help to explain the relative practical performance of the different methods. We apply the methods to data on the association between levels of particulate matter and birth weight in the greater Boston area.

  6. Spatial reasoning in the treatment of systematic sensor errors

    SciTech Connect

    Beckerman, M.; Jones, J.P.; Mann, R.C.; Farkas, L.A.; Johnston, S.E.

    1988-01-01

    In processing ultrasonic and visual sensor data acquired by mobile robots systematic errors can occur. The sonar errors include distortions in size and surface orientation due to the beam resolution, and false echoes. The vision errors include, among others, ambiguities in discriminating depth discontinuities from intensity gradients generated by variations in surface brightness. In this paper we present a methodology for the removal of systematic errors using data from the sonar sensor domain to guide the processing of information in the vision domain, and vice versa. During the sonar data processing some errors are removed from 2D navigation maps through pattern analyses and consistent-labelling conditions, using spatial reasoning about the sonar beam and object characteristics. Others are removed using visual information. In the vision data processing vertical edge segments are extracted using a Canny-like algorithm, and are labelled. Object edge features are then constructed from the segments using statistical and spatial analyses. A least-squares method is used during the statistical analysis, and sonar range data are used in the spatial analysis. 7 refs., 10 figs.

  7. Divided spatial attention and feature-mixing errors.

    PubMed

    Golomb, Julie D

    2015-11-01

    Spatial attention is thought to play a critical role in feature binding. However, often multiple objects or locations are of interest in our environment, and we need to shift or split attention between them. Recent evidence has demonstrated that shifting and splitting spatial attention results in different types of feature-binding errors. In particular, when two locations are simultaneously sharing attentional resources, subjects are susceptible to feature-mixing errors; that is, they tend to report a color that is a subtle blend of the target color and the color at the other attended location. The present study was designed to test whether these feature-mixing errors are influenced by target-distractor similarity. Subjects were cued to split attention across two different spatial locations, and were subsequently presented with an array of colored stimuli, followed by a postcue indicating which color to report. Target-distractor similarity was manipulated by varying the distance in color space between the two attended stimuli. Probabilistic modeling in all cases revealed shifts in the response distribution consistent with feature-mixing errors; however, the patterns differed considerably across target-distractor color distances. With large differences in color, the findings replicated the mixing result, but with small color differences, repulsion was instead observed, with the reported target color shifted away from the other attended color.

  8. Detection of deception about multiple, concealed, mock crime items, based on a spatial-temporal analysis of ERP amplitude and scalp distribution.

    PubMed

    Lui, Ming; Rosenfeld, J Peter

    2008-09-01

    Three groups, two-probe (2PG), three-probe (3PG), and control (CG), performed a mock crime. 2PG and 3PG stole two and three items, respectively, after a baseline "truth block"; the CG stole nothing. Subjects all completed a second "lie block" after the mock crime. There were four stimuli in truth and lie blocks: truth probe (TP), truth irrelevant (TI), lie probe (LP), and lie irrelevant (LI). Stolen items were probes; other items were irrelevants. Spatial-temporal PCA was applied. For the 2PG, subjects' frontal-central component amplitudes in the 520-644-ms temporal component were significantly more positive for LP than for LI stimulus. Individually, 12 of 14 subjects (far better detection than results [72% hits] with non-PCA analyses methods) in the 2PG were detected, with a false positive rate of 4 of 14 in the CG. No difference between LP and LI was found in 3PG data. In summary, spatial-temporal PCA improves detection of concealed information.

  9. Spatial perception errors do not predict pointing errors by individuals with brain lesions.

    PubMed

    Darling, Warren G; Bartelt, Robert; Pizzimenti, Marc A; Rizzo, Matthew

    2008-01-01

    We examined the relationship between errors in sensorimotor transformations (SMT) for reaching to external targets and visual and kinesthetic spatial perception of those targets by participants with damage to the posterior parietal lobule (PPL) and adjacent areas. A total of 12 participants had focal PPL lesions, 7 had with brain lesions outside the PPL, and 10 had no brain lesions. Brain lesions were due to stroke (12) or surgical resection (7). Participants made visually and kinesthetically guided pointing movements to 16 targets with the ipsilesional hand (to minimize effects of motor deficits). Head and eye movements were unrestricted. When full vision was allowed, all participants pointed accurately to visually specified targets. However, participants with PPL lesions made larger vertical plane errors than did neurologically intact control participants in visual and kinesthetic perceptual tasks and in SMT tasks (in which participants reached without vision to targets that had been visually presented). However, across all 29 participants, the size and direction of SMT errors showed low correlation with visual and kinesthetic perceptual errors. Moreover, participants with PPL lesions who made large visual and/or kinesthetic perceptual errors to individual targets also showed weak correlations with SMT errors to those targets. The results are compatible with theories that different neural pathways support perception and action for both the visual and the kinesthetic systems.

  10. Evaluation of a mixed controller that amplifies spatial errors while reducing timing errors.

    PubMed

    Marchal-Crespo, Laura; Baumann, Tanja; Fichmann, Daniela; Maassen, Steve; Duarte, Jaime E; Riener, Robert

    2016-08-01

    Previous results suggest that haptic guidance enhances learning of the timing components of motor tasks, whereas error amplification is better for learning the spatial components. In this paper we evaluate a novel mixed guidance controller that combines haptic guidance and error amplification to simultaneously promote learning of the timing and spatial components. The controller is realized using a saddle-like force field around the desired movement position. This force field has a stable manifold tangential to the trajectory that guides subjects in velocity related aspects. The force field has its unstable manifold perpendicular to the trajectory, which amplifies the normal (spatial) error. We conducted an experiment with twenty nine healthy subjects to test whether training with the mixed guidance controller resulted in better learning than training without guidance or with guidance-as-needed. Subjects trained two tasks: a continuous rhythmic task (circle) and a continuous single task (line). We found that the effectiveness of the training strategy depended on the task. Training with mixed guidance was especially beneficial for learning the timing components of the line, but limited learning of the circle. Perhaps the continuous change in the force directions during training of the circle was too difficult to interpret.

  11. Efficient measurement error correction with spatially misaligned data

    PubMed Central

    Szpiro, Adam A.; Sheppard, Lianne; Lumley, Thomas

    2011-01-01

    Association studies in environmental statistics often involve exposure and outcome data that are misaligned in space. A common strategy is to employ a spatial model such as universal kriging to predict exposures at locations with outcome data and then estimate a regression parameter of interest using the predicted exposures. This results in measurement error because the predicted exposures do not correspond exactly to the true values. We characterize the measurement error by decomposing it into Berkson-like and classical-like components. One correction approach is the parametric bootstrap, which is effective but computationally intensive since it requires solving a nonlinear optimization problem for the exposure model parameters in each bootstrap sample. We propose a less computationally intensive alternative termed the “parameter bootstrap” that only requires solving one nonlinear optimization problem, and we also compare bootstrap methods to other recently proposed methods. We illustrate our methodology in simulations and with publicly available data from the Environmental Protection Agency. PMID:21252080

  12. Spatial uncertainty analysis: Propagation of interpolation errors in spatially distributed models

    USGS Publications Warehouse

    Phillips, D.L.; Marks, D.G.

    1996-01-01

    In simulation modelling, it is desirable to quantify model uncertainties and provide not only point estimates for output variables but confidence intervals as well. Spatially distributed physical and ecological process models are becoming widely used, with runs being made over a grid of points that represent the landscape. This requires input values at each grid point, which often have to be interpolated from irregularly scattered measurement sites, e.g., weather stations. Interpolation introduces spatially varying errors which propagate through the model We extended established uncertainty analysis methods to a spatial domain for quantifying spatial patterns of input variable interpolation errors and how they propagate through a model to affect the uncertainty of the model output. We applied this to a model of potential evapotranspiration (PET) as a demonstration. We modelled PET for three time periods in 1990 as a function of temperature, humidity, and wind on a 10-km grid across the U.S. portion of the Columbia River Basin. Temperature, humidity, and wind speed were interpolated using kriging from 700- 1000 supporting data points. Kriging standard deviations (SD) were used to quantify the spatially varying interpolation uncertainties. For each of 5693 grid points, 100 Monte Carlo simulations were done, using the kriged values of temperature, humidity, and wind, plus random error terms determined by the kriging SDs and the correlations of interpolation errors among the three variables. For the spring season example, kriging SDs averaged 2.6??C for temperature, 8.7% for relative humidity, and 0.38 m s-1 for wind. The resultant PET estimates had coefficients of variation (CVs) ranging from 14% to 27% for the 10-km grid cells. Maps of PET means and CVs showed the spatial patterns of PET with a measure of its uncertainty due to interpolation of the input variables. This methodology should be applicable to a variety of spatially distributed models using interpolated

  13. [Prediction of spatial distribution of forest carbon storage in Heilongjiang Province using spatial error model].

    PubMed

    Liu, Chang; Li, Feng-Ri; Zhen, Zhen

    2014-10-01

    Abstract: Based on the data from Chinese National Forest Inventory (CNFI) and Key Ecological Benefit Forest Monitoring plots (5075 in total) in Heilongjiang Province in 2010 and concurrent meteorological data coming from 59 meteorological stations located in Heilongjiang, Jilin and Inner Mongolia, this paper established a spatial error model (SEM) by GeoDA using carbon storage as dependent variable and several independent variables, including diameter of living trees (DBH), number of trees per hectare (TPH), elevation (Elev), slope (Slope), and product of precipitation and temperature (Rain_Temp). Global Moran's I was computed for describing overall spatial autocorrelations of model results at different spatial scales. Local Moran's I was calculated at the optimal bandwidth (25 km) to present spatial distribution residuals. Intra-block spatial variances were computed to explain spatial heterogeneity of residuals. Finally, a spatial distribution map of carbon storage in Heilongjiang was visualized based on predictions. The results showed that the distribution of forest carbon storage in Heilongjiang had spatial effect and was significantly influenced by stand, topographic and meteorological factors, especially average DBH. SEM could solve the spatial autocorrelation and heterogeneity well. There were significant spatial differences in distribution of forest carbon storage. The carbon storage was mainly distributed in Zhangguangcai Mountain, Xiao Xing'an Mountain and Da Xing'an Mountain where dense, forests existed, rarely distributed in Songnen Plains, while Wanda Mountain had moderate-level carbon storage.

  14. Concealed wire tracing apparatus

    DOEpatents

    Kronberg, James W.

    1994-01-01

    An apparatus and method that combines a signal generator and a passive signal receiver to detect and record the path of partially or completely concealed electrical wiring without disturbing the concealing surface. The signal generator applies a series of electrical pulses to the selected wiring of interest. The applied pulses create a magnetic field about the wiring that can be detected by a coil contained within the signal receiver. An audible output connected to the receiver and driven by the coil reflects the receivers position with respect to the wiring. The receivers audible signal is strongest when the receiver is directly above the wiring and the long axis of the receivers coil is parallel to the wiring. A marking means is mounted on the receiver to mark the location of the wiring as the receiver is directed over the wiring's concealing surface. Numerous marks made on various locations of the concealing surface will trace the path of the wiring of interest.

  15. Spatial exemplars and metrics for characterizing image compression transform error

    NASA Astrophysics Data System (ADS)

    Schmalz, Mark S.; Caimi, Frank M.

    2001-12-01

    The efficient transmission and storage of digital imagery increasingly requires compression to maintain effective channel bandwidth and device capacity. Unfortunately, in applications where high compression ratios are required, lossy compression transforms tend to produce a wide variety of artifacts in decompressed images. Image quality measures (IQMs) have been published that detect global changes in image configuration resulting from the compression or decompression process. Examples include statistical and correlation-based procedures related to mean-squared error, diffusion of energy from features of interest, and spectral analysis. Additional but sparsely-reported research involves local IQMs that quantify feature distortion in terms of objective or subjective models. In this paper, a suite of spatial exemplars and evaluation procedures is introduced that can elicit and measure a wide range of spatial, statistical, or spectral distortions from an image compression transform T. By applying the test suite to the input of T, performance deficits can be highlighted in the transform's design phase, versus discovery under adverse conditions in field practice. In this study, performance analysis is concerned primarily with the effect of compression artifacts on automated target recognition (ATR) algorithm performance. For example, featural distortion can be measured using linear, curvilinear, polygonal, or elliptical features interspersed with various textures or noise-perturbed backgrounds or objects. These simulated target blobs may themselves be perturbed with various types or levels of noise, thereby facilitating measurement of statistical target-background interactions. By varying target-background contrast, resolution, noise level, and target shape, compression transforms can be stressed to isolate performance deficits. Similar techniques can be employed to test spectral, phase and boundary distortions due to decompression. Applicative examples are taken from

  16. Augmented GNSS differential corrections minimum mean square error estimation sensitivity to spatial correlation modeling errors.

    PubMed

    Kassabian, Nazelie; Lo Presti, Letizia; Rispoli, Francesco

    2014-06-11

    Railway signaling is a safety system that has evolved over the last couple of centuries towards autonomous functionality. Recently, great effort is being devoted in this field, towards the use and exploitation of Global Navigation Satellite System (GNSS) signals and GNSS augmentation systems in view of lower railway track equipments and maintenance costs, that is a priority to sustain the investments for modernizing the local and regional lines most of which lack automatic train protection systems and are still manually operated. The objective of this paper is to assess the sensitivity of the Linear Minimum Mean Square Error (LMMSE) algorithm to modeling errors in the spatial correlation function that characterizes true pseudorange Differential Corrections (DCs). This study is inspired by the railway application; however, it applies to all transportation systems, including the road sector, that need to be complemented by an augmentation system in order to deliver accurate and reliable positioning with integrity specifications. A vector of noisy pseudorange DC measurements are simulated, assuming a Gauss-Markov model with a decay rate parameter inversely proportional to the correlation distance that exists between two points of a certain environment. The LMMSE algorithm is applied on this vector to estimate the true DC, and the estimation error is compared to the noise added during simulation. The results show that for large enough correlation distance to Reference Stations (RSs) distance separation ratio values, the LMMSE brings considerable advantage in terms of estimation error accuracy and precision. Conversely, the LMMSE algorithm may deteriorate the quality of the DC measurements whenever the ratio falls below a certain threshold.

  17. Augmented GNSS Differential Corrections Minimum Mean Square Error Estimation Sensitivity to Spatial Correlation Modeling Errors

    PubMed Central

    Kassabian, Nazelie; Presti, Letizia Lo; Rispoli, Francesco

    2014-01-01

    Railway signaling is a safety system that has evolved over the last couple of centuries towards autonomous functionality. Recently, great effort is being devoted in this field, towards the use and exploitation of Global Navigation Satellite System (GNSS) signals and GNSS augmentation systems in view of lower railway track equipments and maintenance costs, that is a priority to sustain the investments for modernizing the local and regional lines most of which lack automatic train protection systems and are still manually operated. The objective of this paper is to assess the sensitivity of the Linear Minimum Mean Square Error (LMMSE) algorithm to modeling errors in the spatial correlation function that characterizes true pseudorange Differential Corrections (DCs). This study is inspired by the railway application; however, it applies to all transportation systems, including the road sector, that need to be complemented by an augmentation system in order to deliver accurate and reliable positioning with integrity specifications. A vector of noisy pseudorange DC measurements are simulated, assuming a Gauss-Markov model with a decay rate parameter inversely proportional to the correlation distance that exists between two points of a certain environment. The LMMSE algorithm is applied on this vector to estimate the true DC, and the estimation error is compared to the noise added during simulation. The results show that for large enough correlation distance to Reference Stations (RSs) distance separation ratio values, the LMMSE brings considerable advantage in terms of estimation error accuracy and precision. Conversely, the LMMSE algorithm may deteriorate the quality of the DC measurements whenever the ratio falls below a certain threshold. PMID:24922454

  18. Pixelated mask spatial carrier phase shifting interferometry algorithms and associated errors

    SciTech Connect

    Kimbrough, Bradley T

    2006-07-01

    In both temporal and spatial carrier phase shifting interferometry, the primary source of phase calculation error results from an error in the relative phase shift between sample points. In spatial carrier phase shifting interferometry, this phase shifting error is caused directly by the wave front under test and is unavoidable. In order to minimize the phase shifting error, a pix elated spatial carrier phase shifting technique has been developed by 4D technologies. This new technique allows for the grouping of phase shifted pixels together around a single point in two dimensions,minimizing the phase shift change due to the spatial variation in the test wavefront. A formula for the phase calculation error in spatial carrier phase shifting interferometry is derived. The error associated with the use of linear N-point averaging algorithms is presented and compared with those of the pix elated spatial carrier technique.

  19. Concealed wire tracing apparatus

    DOEpatents

    Kronberg, J.W.

    1994-05-31

    An apparatus and method that combines a signal generator and a passive signal receiver to detect and record the path of partially or completely concealed electrical wiring without disturbing the concealing surface is disclosed. The signal generator applies a series of electrical pulses to the selected wiring of interest. The applied pulses create a magnetic field about the wiring that can be detected by a coil contained within the signal receiver. An audible output connected to the receiver and driven by the coil reflects the receivers position with respect to the wiring. The receivers audible signal is strongest when the receiver is directly above the wiring and the long axis of the receivers coil is parallel to the wiring. A marking means is mounted on the receiver to mark the location of the wiring as the receiver is directed over the wiring's concealing surface. Numerous marks made on various locations of the concealing surface will trace the path of the wiring of interest. 4 figs.

  20. Concealing with Structured Light

    PubMed Central

    Sun, Jingbo; Zeng, Jinwei; Wang, Xi; Cartwright, Alexander N.; Litchinitser, Natalia M.

    2014-01-01

    While making objects less visible (or invisible) to a human eye or a radar has captured people's imagination for centuries, current attempts towards realization of this long-awaited functionality range from various stealth technologies to recently proposed cloaking devices. A majority of proposed approaches share a number of common deficiencies such as design complexity, polarization effects, bandwidth, losses and the physical size or shape requirement complicating their implementation especially at optical frequencies. Here we demonstrate an alternative way to conceal macroscopic objects by structuring light itself. In our approach, the incident light is transformed into an optical vortex with a dark core that can be used to conceal macroscopic objects. Once such a beam passed around the object it is transformed back into its initial Gaussian shape with minimum amplitude and phase distortions. Therefore, we propose to use that dark core of the vortex beam to conceal an object that is macroscopic yet small enough to fit the dark (negligibly low intensity) region of the beam. The proposed concealing approach is polarization independent, easy to fabricate, lossless, operates at wavelengths ranging from 560 to 700 nm, and can be used to hide macroscopic objects providing they are smaller than vortex core. PMID:24522638

  1. Single-step spatial rotation error separation technique for the ultraprecision measurement of surface profiles.

    PubMed

    Hou, Maosheng; Qiu, Lirong; Zhao, Weiqian; Wang, Fan; Liu, Entao; Ji, Lin

    2014-01-20

    To improve the measurement accuracy of the profilometer for large optical surfaces, a new single-step spatial rotation error separation technique (SSEST) is proposed to separate the surface profile error and spindle spatial rotation error, and a novel SSEST-based system for surface profile measurement is developed. In the process of separation, two sets of measured results at the ith measurement circle are obtained before and after the rotation of error separation table, the surface profile error and spatial rotation error of spindle can be determined using discrete Fourier-transform and harmonic analysis. Theoretical analyses and experimental results indicate that SSEST can accurately separate spatial rotation error of spindle from the measured surface profile results within the range of 1-100 upr and improve the accuracy of surface profile measurements.

  2. Research on controlling middle spatial frequency error of high gradient precise aspheric by pitch tool

    NASA Astrophysics Data System (ADS)

    Wang, Jia; Hou, Xi; Wan, Yongjian; Shi, Chunyan; Zhong, Xianyun

    2016-09-01

    Extreme optical fabrication projects known as EUV and X-ray optic systems, which are representative of today's advanced optical manufacturing technology level, have special requirements for the optical surface quality. In synchroton radiation (SR) beamlines, mirrors of high shape accuracy is always used in grazing incidence. In nanolithograph systems, middle spatial frequency errors always lead to small-angle scattering or flare that reduces the contrast of the image. The slope error is defined for a given horizontal length, the increase or decrease in form error at the end point relative to the starting point is measured. The quality of reflective optical elements can be described by their deviation from ideal shape at different spatial frequencies. Usually one distinguishes between the figure error, the low spatial error part ranging from aperture length to 1mm frequencies, and the mid-high spatial error part from 1mm to 1 μm and from1 μm to some 10 nm spatial frequencies, respectively. Firstly, this paper will disscuss the relationship between slope error and middle spatial frequency error, which both describe the optical surface error along with the form profile. Then, experimental researches will be conducted on a high gradient precise aspheric with pitch tool, which aim to restraining the middle spatial frequency error.

  3. ISAR for concealed objects imaging

    NASA Astrophysics Data System (ADS)

    Zhuravlev, A.; Razevig, V.; Vasiliev, I.; Ivashov, S.; Voronin, V.

    2015-03-01

    A new promising architecture of microwave personnel screening system is analyzed in this paper with numerical simulations. This architecture is based on the concept of inverse aperture synthesis applied to a naturally moving person. The extent of the synthetic aperture is formed by a stationary vertical linear antenna array and by a length of subject's trajectory as he moves in the vicinity of this antenna array. The coherent radar signal processing is achieved by a synchronous 3D video-sensor whose data are used to track the subject. The advantages of the proposed system architecture over currently existing systems are analyzed. Synthesized radar images are obtained by numerical simulations with a human torso model with concealed objects. Various aspects of the system architecture are considered, including: advantages of using sparse antenna arrays to decrease the number of antenna elements, the influence of positioning errors of body surface due to outer clothing. It was shown that detailed radar images of concealed objects can be obtained with a narrow-band signal due to the depth information available from the 3D video sensor. The considered ISAR architecture is considered perspective to be used on infrastructure objects owing to its superior qualities: highest throughput, small footprint, simple design of the radar sub-system, non-required co-operation of the subject.

  4. An upper-bound metric for characterizing spectral and spatial coregistration errors in spectral imaging.

    PubMed

    Skauli, Torbjørn

    2012-01-16

    Coregistration errors in multi- and hyperspectral imaging sensors arise when the spatial sensitivity pattern differs between bands or when the spectral response varies across the field of view, potentially leading to large errors in the recorded image data. In imaging spectrometers, spectral and spatial offset errors are customarily specified as "smile" and "keystone" distortions. However these characteristics do not account for errors resulting from variations in point spread function shape or spectral bandwidth. This paper proposes improved metrics for coregistration error both in the spatial and spectral dimensions. The metrics are essentially the integrated difference between point spread functions. It is shown that these metrics correspond to an upper bound on the error in image data. The metrics enable estimation of actual data errors for a given image, and can be used as part of the merit function in optical design optimization, as well as for benchmarking of spectral image sensors.

  5. Identifying concealment-related responses in the concealed information test.

    PubMed

    Matsuda, Izumi; Nittono, Hiroshi; Ogawa, Tokihiro

    2013-07-01

    The concealed information test (CIT) assesses an examinee's recognition of a crime-relevant item using physiological measures. However, a guilty examinee not only recognizes the crime-relevant item but also conceals the recognition intentionally. In this study, we attempted to identify the effect of concealing the recognition on event-related potentials and autonomic responses. After committing a mock theft of two items, 30 participants received two CITs: one for an item that they had to conceal, and the other for an item that they had disclosed. N2, P3, heart rate, skin conductance, and cutaneous blood flow differed between crime-relevant and irrelevant items in both CITs. In contrast, late positive potential and respiration differed between crime-relevant and irrelevant items only when the examinee needed to conceal. The former measures appear to be related to orienting process, whereas the latter to controlled process related to concealment.

  6. Evaluation of MPEG4-SVC for QoE protection in the context of transmission errors

    NASA Astrophysics Data System (ADS)

    Pitrey, Yohann; Barkowsky, Marcus; Le Callet, Patrick; Pépion, Romuald

    2010-08-01

    Scalable Video Coding (SVC) provides a way to encapsulate several video layers with increasing quality and resolution in a single bitstream. Thus it is particularly adapted to address heterogeneous networks and a wide variety of decoding devices. In this paper, we evaluate the interest of SVC in a different context, which is error concealment after transmission on networks subject to packet loss. The encoded scalable video streams contain two layers with different spatial and temporal resolutions designed for mobile video communications with medium size and average to low bitrates. The main idea is to use the base layer to conceal errors in the higher layers if they are corrupted or lost. The base layer is first upscaled either spatially or temporally to reach the same resolution as the layer to conceal. Two error-concealment techniques using the base layer are then proposed for the MPEG-4 SVC standard, involving frame-level concealment and pixel-level concealment. These techniques are compared to the upscaled base layer as well as to a classical single-layer MPEG- 4 AVC/H.264 error-concealment technique. The comparison is carried out through a subjective experiment, in order to evaluate the Quality-of-Experience of the proposed techniques. We study several scenarios involving various bitrates and resolutions for the base layer of the SVC streams. The results show that SVC-based error concealment can provide significantly higher visual quality than single-layer-based techniques. Moreover, we demonstrate that the resolution and bitrate of the base layer have a strong impact on the perceived quality of the concealment.

  7. Adaptive data assimilation including the effect of spatial variations in observation error

    NASA Astrophysics Data System (ADS)

    Frehlich, Rod

    2006-04-01

    An optimal adaptive data assimilation algorithm is derived using the maximum likelihood method based on a conditional Gaussian probability density function for the first-guess and direct observations of the state variables but including local estimates of the observation and first-guess error statistics. An interpolation of the first-guess field to the observation coordinates is not required under the assumption of locally homogeneous statistics for the random atmosphere. However, the definition of observation error requires a definition of model 'truth' which is defined as a spatial average of the continuous random atmospheric variables. Then the total observation error consists of two independent components: an instrument error and an observation sampling error defined by the spatial average of the observation and the statistics of the local turbulence. Estimates of the observation sampling error statistics are determined from an ensemble of background or first-guess fields or from the analysis of the raw data from instrumented aircraft, Doppler lidars, or radar profilers. The spatial variations of the sampling error are referenced to the local turbulence conditions at each analysis coordinate and therefore each observation can have a different observation error for each nearby analysis coordinate. The extension of the adaptive assimilation concept to include the spatial variations in observation error for statistical interpolation, 3D-Var, 4D-Var, extended Kalman filtering, and ensemble Kalman filtering is also presented for the traditional meaning of observation error, i.e. each observation is assigned a single error. The conditional analysis error is derived for a single observation at the analysis coordinate and multiple observations around the analysis point. Example calculations of the conditional analysis error are presented for a few simple set of observation and measurement geometries to demonstrate the impact of the spatially variable observation errors

  8. Spatial autocorrelation among automated geocoding errors and its effects on testing for disease clustering

    PubMed Central

    Li, Jie; Fang, Xiangming

    2010-01-01

    Automated geocoding of patient addresses is an important data assimilation component of many spatial epidemiologic studies. Inevitably, the geocoding process results in positional errors. Positional errors incurred by automated geocoding tend to reduce the power of tests for disease clustering and otherwise affect spatial analytic methods. However, there are reasons to believe that the errors may often be positively spatially correlated and that this may mitigate their deleterious effects on spatial analyses. In this article, we demonstrate explicitly that the positional errors associated with automated geocoding of a dataset of more than 6000 addresses in Carroll County, Iowa are spatially autocorrelated. Furthermore, through two simulation studies of disease processes, including one in which the disease process is overlain upon the Carroll County addresses, we show that spatial autocorrelation among geocoding errors maintains the power of two tests for disease clustering at a level higher than that which would occur if the errors were independent. Implications of these results for cluster detection, privacy protection, and measurement-error modeling of geographic health data are discussed. PMID:20087879

  9. Spatial error in geocoding physician location data from the AMA Physician Masterfile: implications for spatial accessibility analysis.

    PubMed

    McLafferty, Sara; Freeman, Vincent L; Barrett, Richard E; Luo, Lan; Shockley, Alisa

    2012-04-01

    The accuracy of geocoding hinges on the quality of address information that serves as input to the geocoding process; however errors associated with poor address quality are rarely studied. This paper examines spatial errors that arise due to incorrect address information with respect to physician location data in the United States. Studies of spatial accessibility to physicians in the U.S. typically rely on data from the American Medical Association's Physician Masterfile. These data are problematic because a substantial proportion of physicians only report a mailing address, which is often the physician's home (residential) location, rather than the address for the location where health care is provided. The incorrect geocoding of physicians' practice locations based on inappropriate address information results in a form of geocoding error that has not been widely analyzed. Using data for the Chicago metropolitan region, we analyze the extent and implications of geocoding error for measurement of spatial accessibility to primary care physicians. We geocode the locations of primary care physicians based on mailing addresses and office addresses. The spatial mismatch between the two is computed at the county, zip code and point location scales. Although mailing and office address locations are quite close for many physicians, they are far apart (>20 km) for a substantial minority. Kernel density estimation is used to characterize the spatial distribution of physicians based on office and mailing addresses and to identify areas of high spatial mismatch between the two. Errors are socially and geographically uneven, resulting in overestimation of physician supply in some high-income suburban communities, and underestimation in certain central city locations where health facilities are concentrated. The resulting errors affect local measures of spatial accessibility to primary care, biasing statistical analyses of the associations between spatial access to care and

  10. Loss factors associated with spatial and temporal tracking errors in intersatellite PPM communication links

    NASA Technical Reports Server (NTRS)

    Chen, C. C.; Gardner, C. S.

    1986-01-01

    The performance of an optical PPM intersatellite link in the presence of spatial and temporal tracking errors is investigated. It is shown that for a given rms spatial tracking error, an optimal transmitter beamwidth exists which minimizes the probability of bit error. The power penalty associated with the spatial tracking error when the transmitter beamwidth is adjusted to achieve optimal performance is shown to be large (greater than 9 dB) when the rms pointing jitter becomes a significant fraction (greater than 30 percent) of the diffraction limited beamwidth. The power penalty due to temporal tracking error, on the other hand, is relatively small (less than 0.1 dB) when the tracking loop bandwidth is less than 0.1 percent of the slot frequency. By properly allocating losses to spatial and temporal tracking errors, it is seen that a 10 to the -9th error rate can be achieved for a realistic link design with an approximately 3 dB signal power margin.

  11. Effects and correction of magneto-optic spatial light modulator phase errors in an optical correlator

    NASA Technical Reports Server (NTRS)

    Downie, John D.; Hine, Butler P.; Reid, Max B.

    1992-01-01

    The optical phase errors introduced into an optical correlator by the input and filter plane magnetooptic spatial light modulators have been studied. The magnitude of these phase errors is measured and characterized, their effects on the correlation results are evaluated, and a means of correction by a design modification of the binary phase-only optical-filter function is presented. The efficacy of the phase-correction technique is quantified and is found to restore the correlation characteristics to those obtained in the absence of errors, to a high degree. The phase errors of other correlator system elements are also discussed and treated in a similar fashion.

  12. Fourier decomposition of spatial localization errors reveals an idiotropic dominance of an internal model of gravity.

    PubMed

    De Sá Teixeira, Nuno Alexandre

    2014-12-01

    Given its conspicuous nature, gravity has been acknowledged by several research lines as a prime factor in structuring the spatial perception of one's environment. One such line of enquiry has focused on errors in spatial localization aimed at the vanishing location of moving objects - it has been systematically reported that humans mislocalize spatial positions forward, in the direction of motion (representational momentum) and downward in the direction of gravity (representational gravity). Moreover, spatial localization errors were found to evolve dynamically with time in a pattern congruent with an anticipated trajectory (representational trajectory). The present study attempts to ascertain the degree to which vestibular information plays a role in these phenomena. Human observers performed a spatial localization task while tilted to varying degrees and referring to the vanishing locations of targets moving along several directions. A Fourier decomposition of the obtained spatial localization errors revealed that although spatial errors were increased "downward" mainly along the body's longitudinal axis (idiotropic dominance), the degree of misalignment between the latter and physical gravity modulated the time course of the localization responses. This pattern is surmised to reflect increased uncertainty about the internal model when faced with conflicting cues regarding the perceived "downward" direction.

  13. Quantitative analysis of spatial sampling error in the infant and adult electroencephalogram.

    PubMed

    Grieve, Philip G; Emerson, Ronald G; Isler, Joseph R; Stark, Raymond I

    2004-04-01

    The purpose of this report was to determine the required number of electrodes to record the infant and adult electroencephalogram (EEG) with a specified amount of spatial sampling error. We first developed mathematical theory that governs the spatial sampling of EEG data distributed on a spherical approximation to the scalp. We then used a concentric sphere model of current flow in the head to simulate realistic EEG data. Quantitative spatial sampling error was calculated for the simulated EEG, with additive measurement noise, for 64, 128, and 256 electrodes equally spaced over the surface of the sphere corresponding to the coverage of the human scalp by commercially available "geodesic" electrode arrays. We found the sampling error for the infant to be larger than that for the adult. For example, a sampling error of less than 10% for the adult was obtained with a 64-electrode array but a 256-electrode array was needed for the infant to achieve the same level of error. With the addition of measurement noise, with power 10 times less than that of the EEG, the sampling error increased to 25% for both the infant and adult, for these numbers of electrodes. These results show that accurate measurement of the spatial properties of the infant EEG requires more electrodes than for the adult.

  14. Handheld ultrasound concealed weapons detector

    NASA Astrophysics Data System (ADS)

    Felber, Franklin S.; Wild, Norbert C.; Nunan, Scott C.; Breuner, Dennis; Doft, Frank

    1998-12-01

    A handheld, battery-operated prototype of a remove concealed weapons detector has been built and tested. The concealed weapons detector will enable law enforcement and security officers to detect metallic and nonmetallic weapons concealed beneath clothing remotely from beyond arm's length to about 20 feet. These detectors may be used to: (1) allow hands-off, stand-off frisking of suspects for metallic and nonmetallic weapons; and (2) search for metallic and nonmetallic weapons on cooperative subjects at courthouse entrances and other monitored security portals. We have demonstrated that we image weapons concealed under heavy clothing, not just detect them, at ranges up to 15 feet using the same ultrasound frequency (40 kHz) used by commercial rangefinders. The concealed weapons detector operates much as a rangefinder, but at higher peak fluxes and pulse repetition frequencies. The detector alerts the user to concealed weapons audibly and visibly by detecting ultrasound glints above a body/clothing baseline, and by compensating for changing range and attenuation. The detector locates concealed weapons within a 6-inch illuminated spot at 10 feet. The signal processor eliminates any signal from behind the target.

  15. Accounting for spatial correlation errors in the assimilation of GRACE into hydrological models through localization

    NASA Astrophysics Data System (ADS)

    Khaki, M.; Schumacher, M.; Forootan, E.; Kuhn, M.; Awange, J. L.; van Dijk, A. I. J. M.

    2017-10-01

    Assimilation of terrestrial water storage (TWS) information from the Gravity Recovery And Climate Experiment (GRACE) satellite mission can provide significant improvements in hydrological modelling. However, the rather coarse spatial resolution of GRACE TWS and its spatially correlated errors pose considerable challenges for achieving realistic assimilation results. Consequently, successful data assimilation depends on rigorous modelling of the full error covariance matrix of the GRACE TWS estimates, as well as realistic error behavior for hydrological model simulations. In this study, we assess the application of local analysis (LA) to maximize the contribution of GRACE TWS in hydrological data assimilation. For this, we assimilate GRACE TWS into the World-Wide Water Resources Assessment system (W3RA) over the Australian continent while applying LA and accounting for existing spatial correlations using the full error covariance matrix. GRACE TWS data is applied with different spatial resolutions including 1° to 5° grids, as well as basin averages. The ensemble-based sequential filtering technique of the Square Root Analysis (SQRA) is applied to assimilate TWS data into W3RA. For each spatial scale, the performance of the data assimilation is assessed through comparison with independent in-situ ground water and soil moisture observations. Overall, the results demonstrate that LA is able to stabilize the inversion process (within the implementation of the SQRA filter) leading to less errors for all spatial scales considered with an average RMSE improvement of 54% (e.g., 52.23 mm down to 26.80 mm) for all the cases with respect to groundwater in-situ measurements. Validating the assimilated results with groundwater observations indicates that LA leads to 13% better (in terms of RMSE) assimilation results compared to the cases with Gaussian errors assumptions. This highlights the great potential of LA and the use of the full error covariance matrix of GRACE TWS

  16. Instantaneous detection of spatial gradient errors in differential GNSS

    NASA Astrophysics Data System (ADS)

    Jing, Jing

    Global Navigation Satellite Systems (GNSS) have become a critical element of modern engineering and scientific applications. GPS is currently being used in the design of navigation systems for both civil and military aviation applications. Differential GPS carrier phase measurements between antennas provide a very precise measurement that is useful for these applications. In fact, ground infrastructure has already been implemented in the Ground Based Augmentation System (GBAS) to take advantage of these precise measurements for use in civil aviation. Furthermore, these antennas can also be used to detect and isolate certain signal-in-space (SIS) failures and anomalies that are hazardous to aviation applications, for example the ionospheric anomalies and ephemeris failures. This realization, in turn, has led to the development of numerous carrier-phase based monitors. One drawback of the majority of these monitors is that their performance within a given configuration is dependent on how antennas are paired to form double differences. In contrast, the null space monitor approach is developed to provide consistent detection performance regardless of how the antennas are paired which combines measurements from multiple, spatially separated ground antennas through a null space transformation. The instantaneous carrier phase monitor cannot detect all gradients due to the presence of integer ambiguities. These ambiguities cannot be resolved because the gradient magnitude is unknown a priori. Furthermore, it has been shown that the performance of such monitors is highly dependent on the reference antenna topology. The range of detectable gradients for all carrier phase monitors depends on two factors: the number of antennas and their configuration. Antenna configuration is often overlooked as a means to improve performance. and heuristic arguments typically prevail in the associated siting decisions. However. such heuristics do not provide the maximum detectable range of

  17. A stochastic-dynamic model for the spatial structure of forecast error statistics

    NASA Technical Reports Server (NTRS)

    Balgovind, R.; Dalcher, A.; Ghil, M.; Kalnay, E.

    1983-01-01

    The present investigation is concerned with the presentation of a simplified model of the spatial structure of forecast error statistics, a comparison of the model with actual numerical weather prediction results, and the extent to which simplifying assumptions made in the model are justified. A stochastic-dynamic model is derived for the spatial structure of the global atmospheric mass-field forecast error. The model states that the relative potential vorticity of the forecast error is random. The covariance function of the model's solutions is found to be governed by a simple deterministic equation. The agreement between the stochastic model and actual mass-field forecast errors fields for 12-36 h periods validates the assumptions on which the model is derived. Within this period, the difference between the potential voriticity fields of the atmosphere and of the numerical forecasts used in the comparison is well represented by white noise.

  18. On the impact of covariate measurement error on spatial regression modelling

    PubMed Central

    Huque, Md Hamidul; Bondell, Howard; Ryan, Louise

    2015-01-01

    Summary Spatial regression models have grown in popularity in response to rapid advances in GIS (Geographic Information Systems) technology that allows epidemiologists to incorporate geographically indexed data into their studies. However, it turns out that there are some subtle pitfalls in the use of these models. We show that presence of covariate measurement error can lead to significant sensitivity of parameter estimation to the choice of spatial correlation structure. We quantify the effect of measurement error on parameter estimates, and then suggest two different ways to produce consistent estimates. We evaluate the methods through a simulation study. These methods are then applied to data on Ischemic Heart Disease (IHD). PMID:25729267

  19. Spatial measurement error and correction by spatial SIMEX in linear regression models when using predicted air pollution exposures.

    PubMed

    Alexeeff, Stacey E; Carroll, Raymond J; Coull, Brent

    2016-04-01

    Spatial modeling of air pollution exposures is widespread in air pollution epidemiology research as a way to improve exposure assessment. However, there are key sources of exposure model uncertainty when air pollution is modeled, including estimation error and model misspecification. We examine the use of predicted air pollution levels in linear health effect models under a measurement error framework. For the prediction of air pollution exposures, we consider a universal Kriging framework, which may include land-use regression terms in the mean function and a spatial covariance structure for the residuals. We derive the bias induced by estimation error and by model misspecification in the exposure model, and we find that a misspecified exposure model can induce asymptotic bias in the effect estimate of air pollution on health. We propose a new spatial simulation extrapolation (SIMEX) procedure, and we demonstrate that the procedure has good performance in correcting this asymptotic bias. We illustrate spatial SIMEX in a study of air pollution and birthweight in Massachusetts.

  20. Detection of a concealed object

    DOEpatents

    Keller, Paul E.; Hall, Thomas E.; McMakin, Douglas L.

    2008-04-29

    Disclosed are systems, methods, devices, and apparatus to determine if a clothed individual is carrying a suspicious, concealed object. This determination includes establishing data corresponding to an image of the individual through interrogation with electromagnetic radiation in the 200 MHz to 1 THz range. In one form, image data corresponding to intensity of reflected radiation and differential depth of the reflecting surface is received and processed to detect the suspicious, concealed object.

  1. Detection of a concealed object

    DOEpatents

    Keller, Paul E [Richland, WA; Hall, Thomas E [Kennewick, WA; McMakin, Douglas L [Richland, WA

    2010-11-16

    Disclosed are systems, methods, devices, and apparatus to determine if a clothed individual is carrying a suspicious, concealed object. This determination includes establishing data corresponding to an image of the individual through interrogation with electromagnetic radiation in the 200 MHz to 1 THz range. In one form, image data corresponding to intensity of reflected radiation and differential depth of the reflecting surface is received and processed to detect the suspicious, concealed object.

  2. Nonsimultaneous coupled laser velocimeter measurement technique: Error prediction for spatially noncoincident measurements

    NASA Technical Reports Server (NTRS)

    Reinath, M. S.

    1985-01-01

    A technique for obtaining orthogonal velocity components from nonorthogonal measurements using the NASA Ames Research Center Long-Range Laser Velocimeter (LRLV) is briefly discussed. A description is then presented of the error that occurs when these nonorthogonal measurements are spatially noncoincident because of positioning inaccuracies, and equations are developed for predicting this error. Sample data are presented and a prediction of the expected error for two typical applications is made. To cover other cases in general, a parametric study is conducted and the results are presented in a tabular format.

  3. Error growth patterns in systems with spatial chaos: from coupled map lattices to global weather models.

    PubMed

    Primo, C; Szendro, I G; Rodríguez, M A; Gutiérrez, J M

    2007-03-09

    Error growth in spatiotemporal chaotic systems is investigated by analyzing the interplay between temporal and spatial dynamics. The spatial correlation and localization of relative fluctuations grow and decay indicating two different regimes, before and after saturation by nonlinear effects. This general behavior is shown to hold both in simple coupled map lattices and in global weather models. This explains the increasing or decreasing trends previously observed in the exponential growth rate of these spatiotemporal systems.

  4. Correction of mid-spatial-frequency errors by smoothing in spin motion for CCOS

    NASA Astrophysics Data System (ADS)

    Zhang, Yizhong; Wei, Chaoyang; Shao, Jianda; Xu, Xueke; Liu, Shijie; Hu, Chen; Zhang, Haichao; Gu, Haojin

    2015-08-01

    Smoothing is a convenient and efficient way to correct mid-spatial-frequency errors. Quantifying the smoothing effect allows improvements in efficiency for finishing precision optics. A series experiments in spin motion are performed to study the smoothing effects about correcting mid-spatial-frequency errors. Some of them use a same pitch tool at different spinning speed, and others at a same spinning speed with different tools. Introduced and improved Shu's model to describe and compare the smoothing efficiency with different spinning speed and different tools. From the experimental results, the mid-spatial-frequency errors on the initial surface were nearly smoothed out after the process in spin motion and the number of smoothing times can be estimated by the model before the process. Meanwhile this method was also applied to smooth the aspherical component, which has an obvious mid-spatial-frequency error after Magnetorheological Finishing processing. As a result, a high precision aspheric optical component was obtained with PV=0.1λ and RMS=0.01λ.

  5. Spatial Resolution, Grayscale, and Error Diffusion Trade-offs: Impact on Display System Design

    NASA Technical Reports Server (NTRS)

    Gille, Jennifer L. (Principal Investigator)

    1996-01-01

    We examine technology trade-offs related to grayscale resolution, spatial resolution, and error diffusion for tessellated display systems. We present new empirical results from our psychophysical study of these trade-offs and compare them to the predictions of a model of human vision.

  6. A spatial error model with continuous random effects and an application to growth convergence

    NASA Astrophysics Data System (ADS)

    Laurini, Márcio Poletti

    2017-10-01

    We propose a spatial error model with continuous random effects based on Matérn covariance functions and apply this model for the analysis of income convergence processes (β -convergence). The use of a model with continuous random effects permits a clearer visualization and interpretation of the spatial dependency patterns, avoids the problems of defining neighborhoods in spatial econometrics models, and allows projecting the spatial effects for every possible location in the continuous space, circumventing the existing aggregations in discrete lattice representations. We apply this model approach to analyze the economic growth of Brazilian municipalities between 1991 and 2010 using unconditional and conditional formulations and a spatiotemporal model of convergence. The results indicate that the estimated spatial random effects are consistent with the existence of income convergence clubs for Brazilian municipalities in this period.

  7. A spatial error model with continuous random effects and an application to growth convergence

    NASA Astrophysics Data System (ADS)

    Laurini, Márcio Poletti

    2017-07-01

    We propose a spatial error model with continuous random effects based on Matérn covariance functions and apply this model for the analysis of income convergence processes (β -convergence). The use of a model with continuous random effects permits a clearer visualization and interpretation of the spatial dependency patterns, avoids the problems of defining neighborhoods in spatial econometrics models, and allows projecting the spatial effects for every possible location in the continuous space, circumventing the existing aggregations in discrete lattice representations. We apply this model approach to analyze the economic growth of Brazilian municipalities between 1991 and 2010 using unconditional and conditional formulations and a spatiotemporal model of convergence. The results indicate that the estimated spatial random effects are consistent with the existence of income convergence clubs for Brazilian municipalities in this period.

  8. Spatially coupled low-density parity-check error correction for holographic data storage

    NASA Astrophysics Data System (ADS)

    Ishii, Norihiko; Katano, Yutaro; Muroi, Tetsuhiko; Kinoshita, Nobuhiro

    2017-09-01

    The spatially coupled low-density parity-check (SC-LDPC) was considered for holographic data storage. The superiority of SC-LDPC was studied by simulation. The simulations show that the performance of SC-LDPC depends on the lifting number, and when the lifting number is over 100, SC-LDPC shows better error correctability compared with irregular LDPC. SC-LDPC is applied to the 5:9 modulation code, which is one of the differential codes. The error-free point is near 2.8 dB and over 10-1 can be corrected in simulation. From these simulation results, this error correction code can be applied to actual holographic data storage test equipment. Results showed that 8 × 10-2 can be corrected, furthermore it works effectively and shows good error correctability.

  9. Accounting for spatial correlations of the observation errors with Ensemble Kalman filters

    NASA Astrophysics Data System (ADS)

    Cosme, Emmanuel; Jean-Michel, Brankart; Clément, Ubelmann; Jacques, Verron; Pierre, Brasseur

    2013-04-01

    The standard Kalman filter observational update requires the inversion of the innovation error covariance matrix, what is often impractical. Most implementations of the Ensemble Kalman filter circumvent this difficulty assuming the diagonality of the observation error covariance matrix, what makes the analysis calculation numerically tractable. However, when observation errors are actually correlated spatially, such hypothesis leads to an inappropriate use of observations. Experiments show that the analysis state error variances yielded by the Ensemble Kalman filter can be severely underestimated. In this presentation, we describe a parameterization of the observation error covariance matrix which preserves its diagonal shape, but represents a simple first order autoregressive correlation structure of the observation errors. This parameterization is based upon an augmentation of the observation vector with gradients of observations. Numerical applications to ocean altimetry show the detrimental effects of specifying a diagonal matrix when observations errors are correlated, and how the new parameterization not only removes the detrimental effects of correlations, but also makes use of these correlations to improve the data assimilation products.

  10. Handheld ultrasonic concealed weapon detector

    NASA Astrophysics Data System (ADS)

    Wilde, Norbert; Niederhaus, Steve; Lam, Hon; Lum, Chris

    2002-08-01

    A handheld, battery-operated prototype of a concealed weapon detector (CWD) has been built and tested. Designed to detect both metallic and non-metallic weapons, the sensor utilizes focused ultrasound (40 kHz frequency) to remotely detect concealed objects from beyond arm's length out to a range of about 25 feet (8 meters). Applications include weapon detection in prison settings, by officers in the field for stand-off frisking of suspects, and as supplemental security at courthouse entrances and other monitored portals. The detector emits an adjustable, audible alarm (with provision for an earphone jack) as well as a visible light-bar indicator when an object has been detected. An aiming light, with momentary switch, allows the user to accurately determine the location of the concealed object. A presentation of the detector's capabilities and limitations will be presented along with probability of detection (PD) data obtained using the latest prototype version.

  11. Spatial averaging errors in creating hemispherical reflectance (albedo) maps from directional reflectance data

    NASA Technical Reports Server (NTRS)

    Kimes, D. S.; Kerber, A. G.; Sellers, P. J.

    1993-01-01

    Spatial averaging errors which may occur when creating hemispherical reflectance maps for different cover types from direct nadir technique to estimate the hemispherical reflectance are assessed by comparing the results with those obtained with a knowledge-based system called VEG (Kimes et al., 1991, 1992). It was found that hemispherical reflectance errors provided by using VEG are much less than those using the direct nadir techniques, depending on conditions. Suggestions are made concerning sampling and averaging strategies for creating hemispherical reflectance maps for photosynthetic, carbon cycle, and climate change studies.

  12. A parametric multiclass Bayes error estimator for the multispectral scanner spatial model performance evaluation

    NASA Technical Reports Server (NTRS)

    Mobasseri, B. G.; Mcgillem, C. D.; Anuta, P. E. (Principal Investigator)

    1978-01-01

    The author has identified the following significant results. The probability of correct classification of various populations in data was defined as the primary performance index. The multispectral data being of multiclass nature as well, required a Bayes error estimation procedure that was dependent on a set of class statistics alone. The classification error was expressed in terms of an N dimensional integral, where N was the dimensionality of the feature space. The multispectral scanner spatial model was represented by a linear shift, invariant multiple, port system where the N spectral bands comprised the input processes. The scanner characteristic function, the relationship governing the transformation of the input spatial, and hence, spectral correlation matrices through the systems, was developed.

  13. A numerical method for multigroup slab-geometry discrete ordinates problems with no spatial truncation error

    SciTech Connect

    Barros, R.C. de; Larsen, E.W. )

    1991-01-01

    A generalization of the one-group Spectral Green's Function (SGF) method is developed for multigroup, slab-geometry discrete ordinates (S{sub N}) problems. The multigroup SGF method is free from spatial truncation errors; it generated numerical values for the cell-edge and cell-average angular fluxes that agree with the analytic solution of the multigroup S{sub N} equations. Numerical results are given to illustrate the method's accuracy.

  14. Performance evaluation of pitch lap in correcting mid-spatial-frequency errors under different smoothing parameters

    NASA Astrophysics Data System (ADS)

    Xu, Lichao; Wan, Yongjian; Liu, Haitao; Wang, Jia

    2016-10-01

    Smoothing is a convenient and efficient way to restrain middle spatial frequency (MSF) errors. Based on the experience, lap diameter, rotation speed, lap pressure and the hardness of pitch layer are important to correcting MSF errors. Therefore, nine groups of experiments are designed with the orthogonal method to confirm the significance of the above parameters. Based on the Zhang's model, PV (Peak and Valley) and RMS (Root Mean Square) versus processing cycles are analyzed before and after smoothing. At the same time, the smoothing limit and smoothing rate for different parameters to correct MSF errors are analyzed. Combined with the deviation analysis, we distinguish between dominant and subordinate parameters, and find out the optimal combination and law of various parameters, so as to guide the further research and fabrication.

  15. Handheld Concealed Weapons Detector Development

    DTIC Science & Technology

    2003-03-01

    Enforcement, Edward M. Carapezza, Donald Spector, Eds., Proc. SPIE 2938, 110 - 119 (1997). 3. Franklin Felber, Norbert Wild, Scott Nunan , Dennis Breuner... Nunan , D. Breuner, and F. Doft, "Handheld Ultrasound Concealed-Weapons Detector," in Enforcement and Security Technologies, A. Trent DePersia, J. J

  16. Effects of errors and gaps in spatial data sets on assessment of conservation progress.

    PubMed

    Visconti, P; Di Marco, M; Álvarez-Romero, J G; Januchowski-Hartley, S R; Pressey, R L; Weeks, R; Rondinini, C

    2013-10-01

    Data on the location and extent of protected areas, ecosystems, and species' distributions are essential for determining gaps in biodiversity protection and identifying future conservation priorities. However, these data sets always come with errors in the maps and associated metadata. Errors are often overlooked in conservation studies, despite their potential negative effects on the reported extent of protection of species and ecosystems. We used 3 case studies to illustrate the implications of 3 sources of errors in reporting progress toward conservation objectives: protected areas with unknown boundaries that are replaced by buffered centroids, propagation of multiple errors in spatial data, and incomplete protected-area data sets. As of 2010, the frequency of protected areas with unknown boundaries in the World Database on Protected Areas (WDPA) caused the estimated extent of protection of 37.1% of the terrestrial Neotropical mammals to be overestimated by an average 402.8% and of 62.6% of species to be underestimated by an average 10.9%. Estimated level of protection of the world's coral reefs was 25% higher when using recent finer-resolution data on coral reefs as opposed to globally available coarse-resolution data. Accounting for additional data sets not yet incorporated into WDPA contributed up to 6.7% of additional protection to marine ecosystems in the Philippines. We suggest ways for data providers to reduce the errors in spatial and ancillary data and ways for data users to mitigate the effects of these errors on biodiversity assessments. © 2013 Society for Conservation Biology.

  17. A hybrid frame concealment algorithm for H.264/AVC.

    PubMed

    Yan, Bo; Gharavi, Hamid

    2010-01-01

    In packet-based video transmissions, packets loss due to channel errors may result in the loss of the whole video frame. Recently, many error concealment algorithms have been proposed in order to combat channel errors; however, most of the existing algorithms can only deal with the loss of macroblocks and are not able to conceal the whole missing frame. In order to resolve this problem, in this paper, we have proposed a new hybrid motion vector extrapolation (HMVE) algorithm to recover the whole missing frame, and it is able to provide more accurate estimation for the motion vectors of the missing frame than other conventional methods. Simulation results show that it is highly effective and significantly outperforms other existing frame recovery methods.

  18. Handheld ultrasonic concealed weapon detector

    NASA Astrophysics Data System (ADS)

    Wild, Norbert C.; Doft, Frank; Breuner, Dennis; Felber, Franklin S.

    2001-02-01

    A handheld, battery-operated prototype of a concealed weapon detector has been built and tested. Designed to detect both metallic and non-metallic weapons, the sensor utilizes focused ultrasound (40 kHz frequency) to remotely detect concealed objects from beyond arm's length out to a range of about 12 feet (4 meters). The detector can be used in prison settings, by officers in the field to allow for stand-off frisking of suspects, and to supplement security at courthouse entrances and other monitored portals. The detector emits an audible alarm (with provision for an earphone jack) as well as a visible light-bar indicator when an object is detected. A high intensity aiming light, with momentary switch, allows the user to accurately determine the location of the concealed object. Current efforts are aimed at increasing the probability of detection, reducing the false-alarm rate, and extending the range of detectability out to 20 feet. Plans for accomplishing these tasks will be presented together with data showing the effective range and probability of detection for the present system.

  19. Standoff detection of concealed handguns

    NASA Astrophysics Data System (ADS)

    Rezgui, Nacer; Andrews, David; Bowring, Nicholas; Harmer, Stuart; Southgate, Matthew

    2008-04-01

    An active technique for the standoff detection and identification of concealed conducting items such as handguns and knives is presented. This technique entails illuminating an object with wide range stepped millimetre wave radiation and inducing a local electromagnetic field comprised of a superposition of modes. The coupling to these modes from the illuminating and scattered fields is, in general, frequency dependent and this forms the basis for the detection and identification of conducting items. The object needs to be fully illuminated if a full spectrum of modes and therefore a full frequency response are to be excited and collected. The scattered EM power is measured at "stand off" distance of several metres as the illuminating field is frequency swept and patterns in frequency response characteristic to the target item being sought are looked for. This system relies on contributions from the aspect independent late time responses employed by Baum1 together with aspect independent information derived specifically from gun barrels and polarisation from scattering effects. This technique is suitable for a deployable gun and concealed weapons detection system and does not rely on imaging techniques for determining the presence of a gun. Experimental sets of responses from typical metal or partially conducting objects such as keys, mobile phones and concealed handguns are presented at a range of frequencies.

  20. Physical optimization of quantum error correction circuits with spatially separated quantum dot spins.

    PubMed

    Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

    2013-05-20

    We propose an efficient protocol for optimizing the physical implementation of three-qubit quantum error correction with spatially separated quantum dot spins via virtual-photon-induced process. In the protocol, each quantum dot is trapped in an individual cavity and each two cavities are connected by an optical fiber. We propose the optimal quantum circuits and describe the physical implementation for correcting both the bit flip and phase flip errors by applying a series of one-bit unitary rotation gates and two-bit quantum iSWAP gates that are produced by the long-range interaction between two distributed quantum dot spins mediated by the vacuum fields of the fiber and cavity. The protocol opens promising perspectives for long distance quantum communication and distributed quantum computation networks.

  1. Sinusoidal Siemens star spatial frequency response measurement errors due to misidentified target centers

    DOE PAGES

    Birch, Gabriel Carisle; Griffin, John Clark

    2015-07-23

    Numerous methods are available to measure the spatial frequency response (SFR) of an optical system. A recent change to the ISO 12233 photography resolution standard includes a sinusoidal Siemens star test target. We take the sinusoidal Siemens star proposed by the ISO 12233 standard, measure system SFR, and perform an analysis of errors induced by incorrectly identifying the center of a test target. We show a closed-form solution for the radial profile intensity measurement given an incorrectly determined center and describe how this error reduces the measured SFR of the system. As a result, using the closed-form solution, we proposemore » a two-step process by which test target centers are corrected and the measured SFR is restored to the nominal, correctly centered values.« less

  2. Sinusoidal Siemens star spatial frequency response measurement errors due to misidentified target centers

    SciTech Connect

    Birch, Gabriel Carisle; Griffin, John Clark

    2015-07-23

    Numerous methods are available to measure the spatial frequency response (SFR) of an optical system. A recent change to the ISO 12233 photography resolution standard includes a sinusoidal Siemens star test target. We take the sinusoidal Siemens star proposed by the ISO 12233 standard, measure system SFR, and perform an analysis of errors induced by incorrectly identifying the center of a test target. We show a closed-form solution for the radial profile intensity measurement given an incorrectly determined center and describe how this error reduces the measured SFR of the system. As a result, using the closed-form solution, we propose a two-step process by which test target centers are corrected and the measured SFR is restored to the nominal, correctly centered values.

  3. Sinusoidal Siemens star spatial frequency response measurement errors due to misidentified target centers

    NASA Astrophysics Data System (ADS)

    Birch, Gabriel C.; Griffin, John C.

    2015-07-01

    Numerous methods are available to measure the spatial frequency response (SFR) of an optical system. A recent change to the ISO 12233 photography resolution standard includes a sinusoidal Siemens star test target. We take the sinusoidal Siemens star proposed by the ISO 12233 standard, measure system SFR, and perform an analysis of errors induced by incorrectly identifying the center of a test target. We show a closed-form solution for the radial profile intensity measurement given an incorrectly determined center and describe how this error reduces the measured SFR of the system. Using the closed-form solution, we propose a two-step process by which test target centers are corrected and the measured SFR is restored to the nominal, correctly centered values.

  4. The Compact Network RTK Method: An Effective Solution to Reduce GNSS Temporal and Spatial Decorrelation Error

    NASA Astrophysics Data System (ADS)

    Park, Byungwoon; Kee, Changdon

    This paper proposes a method that combines compact real-time kinematic (RTK) and reference station (RS) networking techniques, and shows that this approach can reduce both the temporal and spatial decorrelation error. The compact RTK method compatibility with all the conventional network RTK systems, i.e., Master-Auxiliary Concept (MAC), Virtual Reference Stations (VRS), and Fl40 s and determines position with 68 cm vertical error (95%) in a 100 by 100 km region. Moreover, the Compact Network RTK approach enables network RTK service providers to reduce the data-link bandwidth for correction messages to 5-700 bps (bit/s) down from several thousand bps, currently 9600 bps of GPRS/GSM, without a severe degradation of accuracy.

  5. Spatial Distribution of the Errors in Modeling the Mid-Latitude Critical Frequencies by Different Models

    NASA Astrophysics Data System (ADS)

    Kilifarska, N. A.

    There are some models that describe the spatial distribution of greatest frequency yielding reflection from the F2 ionospheric layer (foF2). However, the distribution of the models' errors over the globe and how they depend on seasons, solar activity, etc., are unknown till this time. So the aim of the present paper is to compare the accuracy in describing the latitudinal and longitudinal variation of the mid-latitude maximum electron density, of CCIR, URSI, and a new created theoretical model. A comparison between the above mentioned models and all available from Boulder's data bank VI data (among 35 deg and 70 deg) have been made. Data for three whole years with different solar activity - 1976 (F_10.7 = 73.6), 1981 (F_10.7 = 20.6), 1983 (F_10.7 = 119.6) have been compared. The final results show that: 1. the areas with greatest and smallest errors depend on UT, season and solar activity; 2. the error distribution of CCIR and URSI models are very similar and are not coincident with these ones of theoretical model. The last result indicates that the theoretical model, described briefly bellow, may be a real alternative to the empirical CCIR and URSI models. The different spatial distribution of the models' errors gives a chance for the users to choose the most appropriate model, depending on their needs. Taking into account that the theoretical models have equal accuracy in region with many or without any ionosonde station, this result shows that our model can be used to improve the global mapping of the mid-latitude ionosphere. Moreover, if Re values of the input aeronomical parameters (neutral composition, temperatures and winds), are used - it may be expected that this theoretical model can be applied for Re or almost Re-time mapping of the main ionospheric parameters (foF2 and hmF2).

  6. Spatial sequence memory and spatial error monitoring in the Groton Maze Learning Task (GMLT): A validation study of GMLT sub-measures in healthy children.

    PubMed

    Thomas, Elizabeth; Maruff, Paul; Paul, Jacob; Reeve, Robert

    2016-01-01

    The stepping-stone variant of the hidden pathway maze learning (HPML) task paradigm has been extensively used to investigate cognitive functions in neuropsychology and neuropharmacology. Previous studies have used total error across trials, as well as rule-break errors and learning errors, to define spatial memory and/or executive function in healthy and impaired adults and children. However, the construct validity of performance measures on HPML tasks has not been established in healthy children. To assess the construct validity of measures of exploratory and rule-break errors on the Groton Maze Learning Task (GMLT) measures of spatial sequence memory (Corsi Blocks Task) and spatial error monitoring (Continuous Paired Associate Learning; CPAL) were used. The results indicate that Corsi span predicted GMLT spatial sequence memory and CPAL accuracy predicted GMLT spatial error monitoring. The construct validity of the GMLT as a measure of spatial memory and executive function are discussed with regard to prior research using HPML tasks in neuropsychological contexts.

  7. Visulization of Time-Varying Multiresolution Date Using Error-Based Temporal-Spatial Resuse

    SciTech Connect

    Nuber, C; LaMar, E; Hamann, B; Joy, K

    2002-04-22

    In this paper, we report results on exploration of two-dimensional (2D) time varying datasets. We extend the notion of multiresolution spatial data approximation of static datasets to spatio-temporal approximation of time-varying datasets. Time-varying datasets typically do not change ''uniformly,'' i.e., some spatial sub-domains can experience only little or no change for extended periods of time. In these sub-domains, we show that approximation error bounds can be met when using sub-domains from other time-steps effectively. We generate a more general approximation scheme where sub-domains may approximate congruent sub-domains from any other time steps. While this incurs an O(T2) overhead, where T is the total number of time-steps, we show significant reduction in data transmission. We also discuss ideas for improvements to reduce overhead.

  8. Time-Order Errors in Duration Judgment Are Independent of Spatial Positioning

    PubMed Central

    Harrison, Charlotte; Binetti, Nicola; Mareschal, Isabelle; Johnston, Alan

    2017-01-01

    Time-order errors (TOEs) occur when the discriminability between two stimuli are affected by the order in which they are presented. While TOEs have been studied since the 1860s, it is unknown whether the spatial properties of a stimulus will affect this temporal phenomenon. In this experiment, we asked whether perceived duration, or duration discrimination, might be influenced by whether two intervals in a standard two-interval method of constants paradigm were spatially overlapping in visual short-term memory. Two circular sinusoidal gratings (one standard and the other a comparison) were shown sequentially and participants judged which of the two was presented for a longer duration. The test stimuli were either spatially overlapping (in different spatial frames) or separate. Stimulus order was randomized between trials. The standard stimulus lasted 600 ms, and the test stimulus had one of seven possible values (between 300 and 900 ms). There were no overall significant differences observed between spatially overlapping and separate stimuli. However, in trials where the standard stimulus was presented second, TOEs were greater, and participants were significantly less sensitive to differences in duration. TOEs were also greater in conditions involving a saccade. This suggests there is an intrinsic memory component to two interval tasks in that the information from the first interval has to be stored; this is more demanding when the standard is presented in the second interval. Overall, this study suggests that while temporal information may be encoded in some spatial form, it is not dependent on visual short-term memory. PMID:28337162

  9. Evidence for Spatially Correlated Gaia Parallax Errors in the Kepler Field

    NASA Astrophysics Data System (ADS)

    Zinn, Joel C.; Huber, Daniel; Pinsonneault, Marc H.; Stello, Dennis

    2017-08-01

    We present evidence for a spatially dependent systematic error in the first data release of Gaia parallaxes based on comparisons to asteroseismic parallaxes in the Kepler field and provide a parameterized model of the angular dependence of these systematics. We report an error of {0.059}-0.004+0.004 mas on scales of 0.°3, which decreases for larger scales to become {0.011}-0.004+0.006 mas at 8°. This is consistent with the ˜2% zero-point offset for the whole sample discussed by Huber et al. and is compatible with the effect predicted by the Gaia team. Our results are robust to dust prescriptions and choices in temperature scales used to calculate asteroseismic parallaxes. We also do not find evidence for significant differences in the signal when using red clump versus red giant stars. Our approach allows us to quantify and map the correlations in an astrophysically interesting field, resulting in a parameterized model of the spatial systematics that can be used to construct a covariance matrix for any work that relies on TGAS parallaxes.

  10. A Stochastic Technique for Error Correction and Spatial Downscaling of Global Gridded Precipitation Products

    NASA Astrophysics Data System (ADS)

    Seyyedi, H.; Kaheil, Y.; Anagnostou, E. N.; McCollum, J.; Beighley, E.

    2013-12-01

    Deriving flood maps requires an accurate characterization of precipitation variability at high spatio-temporal resolution. Most of the available global-scale gridded precipitation products are available at resolutions (e.g., 25 km) not directly applicable to flood modeling. An error correction and spatial downscaling method based on a two-dimensional satellite rainfall error model (SREM2D) is tested in this study based on a long-term (2001-2010) dataset. Specifically, the model is applied on two rainfall datasets: a satellite precipitation product (TRMM-3B42.V7 at 0.25 degree) and a global land-atmosphere re-analysis product (GLDAS-CLM at 1 degree), to produce error corrected rainfall ensembles at 0.05 degree spatial resolution. The NCEP hourly, 4-km resolution multi-sensor precipitation product (WSR-88D stage IV gauge-adjusted radar-rainfall product) is used as the reference rainfall dataset. The Hillslope River Routing (HRR) hydrologic model is forced with the downscaled ensemble rainfall data to produce an ensemble of runoff values. The Susquehanna River basin is the study area, consisting of 1000 sub-basins ranging from 39 to 67,000 square kilometers including complex terrain and high latitude locations. There are 437 significant storm events selected over the study area based on the 10-year database. The analysis performed is based on 60 percent of events in each season kept for model calibration and 40 percent for validation. The statistical analysis consists of two parts: (1) evaluation of error metrics (relative standard deviation and efficiency coefficient) to quantify improvements in rainfall and runoff simulations as function of basin size and storm severity, and (2) ensemble verification (exceedance probability and mean uncertainty ratio) of the rainfall and runoff ensembles to assess the accuracy of the ensemble-based uncertainty characterization. The study investigates how well the ensemble of downscaled and error-corrected rainfall data performs

  11. Method for imaging a concealed object

    DOEpatents

    Davidson, James R [Idaho Falls, ID; Partin, Judy K [Idaho Falls, ID; Sawyers, Robert J [Idaho Falls, ID

    2007-07-03

    A method for imaging a concealed object is described and which includes a step of providing a heat radiating body, and wherein an object to be detected is concealed on the heat radiating body; imaging the heat radiating body to provide a visibly discernible infrared image of the heat radiating body; and determining if the visibly discernible infrared image of the heat radiating body is masked by the presence of the concealed object.

  12. Activation and inhibition of posterior parietal cortex have bi-directional effects on spatial errors following interruptions

    PubMed Central

    Foroughi, Cyrus K.; Blumberg, Eric J.; Parasuraman, Raja

    2015-01-01

    Interruptions to ongoing mental activities are omnipresent in our modern digital world, but the brain networks involved in interrupted performance are not known, nor have the activation of those networks been modulated. Errors following interruptions reflect failures in spatial memory, whose maintenance is supported by a brain network including the right posterior parietal cortex (PPC). The present study therefore used bi-directional transcranial Direct Current Stimulation (tDCS) of right PPC to examine the neuromodulation of spatial errors following interruptions, as well as performance on another PPC-dependent task, mental rotation. Anodal stimulation significantly reduced the number of interruption-based errors and increased mental rotation accuracy whereas cathodal stimulation significantly increased errors and reduced mental rotation accuracy. The results provide evidence for a causal role of the PPC in the maintenance of spatial representations during interrupted task performance. PMID:25628543

  13. Error propagation models to examine the effects of geocoding quality on spatial analysis of individual-level datasets.

    PubMed

    Zandbergen, P A; Hart, T C; Lenzer, K E; Camponovo, M E

    2012-04-01

    The quality of geocoding has received substantial attention in recent years. A synthesis of published studies shows that the positional errors of street geocoding are somewhat unique relative to those of other types of spatial data: (1) the magnitude of error varies strongly across urban-rural gradients; (2) the direction of error is not uniform, but strongly associated with the properties of local street segments; (3) the distribution of errors does not follow a normal distribution, but is highly skewed and characterized by a substantial number of very large error values; and (4) the magnitude of error is spatially autocorrelated and is related to properties of the reference data. This makes it difficult to employ analytic approaches or Monte Carlo simulations for error propagation modeling because these rely on generalized statistical characteristics. The current paper describes an alternative empirical approach to error propagation modeling for geocoded data and illustrates its implementation using three different case-studies of geocoded individual-level datasets. The first case-study consists of determining the land cover categories associated with geocoded addresses using a point-in-raster overlay. The second case-study consists of a local hotspot characterization using kernel density analysis of geocoded addresses. The third case-study consists of a spatial data aggregation using enumeration areas of varying spatial resolution. For each case-study a high quality reference scenario based on address points forms the basis for the analysis, which is then compared to the result of various street geocoding techniques. Results show that the unique nature of the positional error of street geocoding introduces substantial noise in the result of spatial analysis, including a substantial amount of bias for some analysis scenarios. This confirms findings from earlier studies, but expands these to a wider range of analytical techniques. Copyright © 2012 Elsevier Ltd

  14. Error propagation models to examine the effects of geocoding quality on spatial analysis of individual-level datasets

    PubMed Central

    Zandbergen, P.A.; Hart, T.C.; Lenzer, K.E.; Camponovo, M.E.

    2012-01-01

    The quality of geocoding has received substantial attention in recent years. A synthesis of published studies shows that the positional errors of street geocoding are somewhat unique relative to those of other types of spatial data: 1) the magnitude of error varies strongly across urban-rural gradients; 2) the direction of error is not uniform, but strongly associated with the properties of local street segments; 3) the distribution of errors does not follow a normal distribution, but is highly skewed and characterized by a substantial number of very large error values; and 4) the magnitude of error is spatially autocorrelated and is related to properties of the reference data. This makes it difficult to employ analytic approaches or Monte Carlo simulations for error propagation modeling because these rely on generalized statistical characteristics. The current paper describes an alternative empirical approach to error propagation modeling for geocoded data and illustrates its implementation using three different case-studies of geocoded individual-level datasets. The first case-study consists of determining the land cover categories associated with geocoded addresses using a point-in-raster overlay. The second case-study consists of a local hotspot characterization using kernel density analysis of geocoded addresses. The third case-study consists of a spatial data aggregation using enumeration areas of varying spatial resolution. For each case-study a high quality reference scenario based on address points forms the basis for the analysis, which is then compared to the result of various street geocoding techniques. Results show that the unique nature of the positional error of street geocoding introduces substantial noise in the result of spatial analysis, including a substantial amount of bias for some analysis scenarios. This confirms findings from earlier studies, but expands these to a wider range of analytical techniques. PMID:22469492

  15. Hybrid S{sub N} numerical method free from spatial truncation error for slab lattice calculations

    SciTech Connect

    Barros, R.C.

    1994-12-31

    In typical lattice cells where a highly absorbing, small fuel element is embedded in the moderator (a large weakly absorbing medium), high-order transport methods become unnecessary. In this paper we describe a hybrid discrete ordinates (S{sub N}) nodal method for slab lattice calculations. This hybrid S{sub N} method combines the convenience of a low-order S{sub N} method in the moderator with a high-order S{sub N} method in the fuel. The idea is based on the fact that in weakly absorbing media whose physical size is several neutron mean free paths in extent, even the S{sub 2} method (P{sub 1} approximation), leads to an accurate result. We use special fuel-moderator interface conditions and the spectral Green`s function (SGF) numerical nodal method completely free from spatial truncation error, to calculate the neutron flux distribution and the disadvantage factor.

  16. A spatial explicit strategy reduces error but interferes with sensorimotor adaptation

    PubMed Central

    Benson, Bryan L.; Anguera, Joaquin A.

    2011-01-01

    Although sensorimotor adaptation is typically thought of as an implicit form of learning, it has been shown that participants who gain explicit awareness of the nature of the perturbation during adaptation exhibit more learning than those who do not. With rare exceptions, however, explicit awareness is typically polled at the end of the study. Here, we provided participants with either an explicit spatial strategy or no instructions before learning. Early in learning, explicit instructions greatly reduced movement errors but also resulted in increased trial-to-trial variability and longer reaction times. Late in adaptation, performance was indistinguishable between the explicit and implicit groups, but the mechanisms underlying performance improvements remained fundamentally different, as revealed by catch trials. The progression of implicit recalibration in the explicit group was modulated by the use of an explicit strategy: these participants showed a lower level of recalibration as well as decreased aftereffects. This phenomenon may be due to the reduced magnitude of errors made to the target during adaptation or inhibition of implicit learning mechanisms by explicit processing. PMID:21451054

  17. Unified error model based spatial error compensation for four types of CNC machining center: Part I-Singular function based unified error model

    NASA Astrophysics Data System (ADS)

    Fan, Kaiguo; Yang, Jianguo; Yang, Liyan

    2015-08-01

    To unify the error model for four types of CNC machining center, the comprehensive error model of each type of CNC machining center was established using the homogenous transformation matrix (HTM). The internal rules between the HTMs and the kinematic chains were analyzed in this research. The analysis results show that the HTM elements associated with the motion axes which are at the rear of the reference coordinate system are positive value. On the contrary, the HTM elements associated with the motion axes which are at the front of the reference coordinate system are negative value. To express these internal rules, the singular function was introduced to the HTMs. And a unified error model for four types of CNC machining center was established based on the HTM and the singular function. The unified error model includes 18 error elements which are the main factors affecting the machining accuracy of CNC machine tools. The practical results show that the unified error model is not only suitable for vertical machining center but also suitable for horizontal machining center.

  18. Spatial-carrier phase-shifting digital holography utilizing spatial frequency analysis for the correction of the phase-shift error.

    PubMed

    Tahara, Tatsuki; Shimozato, Yuki; Awatsuji, Yasuhiro; Nishio, Kenzo; Ura, Shogo; Matoba, Osamu; Kubota, Toshihiro

    2012-01-15

    We propose a single-shot digital holography in which the complex amplitude distribution is obtained by spatial-carrier phase-shifting (SCPS) interferometry and the correction of the inherent phase-shift error occurred in this interferometry. The 0th order diffraction wave and the conjugate image are removed by phase-shifting interferometry and Fourier transform technique, respectively. The inherent error is corrected in the spatial frequency domain. The proposed technique does not require an iteration process to remove the unwanted images and has an advantage in the field of view in comparison to a conventional SCPS technique.

  19. Improving filtering and prediction of spatially extended turbulent systems with model errors through stochastic parameter estimation

    SciTech Connect

    Gershgorin, B.; Harlim, J. Majda, A.J.

    2010-01-01

    The filtering and predictive skill for turbulent signals is often limited by the lack of information about the true dynamics of the system and by our inability to resolve the assumed dynamics with sufficiently high resolution using the current computing power. The standard approach is to use a simple yet rich family of constant parameters to account for model errors through parameterization. This approach can have significant skill by fitting the parameters to some statistical feature of the true signal; however in the context of real-time prediction, such a strategy performs poorly when intermittent transitions to instability occur. Alternatively, we need a set of dynamic parameters. One strategy for estimating parameters on the fly is a stochastic parameter estimation through partial observations of the true signal. In this paper, we extend our newly developed stochastic parameter estimation strategy, the Stochastic Parameterization Extended Kalman Filter (SPEKF), to filtering sparsely observed spatially extended turbulent systems which exhibit abrupt stability transition from time to time despite a stable average behavior. For our primary numerical example, we consider a turbulent system of externally forced barotropic Rossby waves with instability introduced through intermittent negative damping. We find high filtering skill of SPEKF applied to this toy model even in the case of very sparse observations (with only 15 out of the 105 grid points observed) and with unspecified external forcing and damping. Additive and multiplicative bias corrections are used to learn the unknown features of the true dynamics from observations. We also present a comprehensive study of predictive skill in the one-mode context including the robustness toward variation of stochastic parameters, imperfect initial conditions and finite ensemble effect. Furthermore, the proposed stochastic parameter estimation scheme applied to the same spatially extended Rossby wave system demonstrates

  20. Spatial learning efficiency and error monitoring in normal aging: an investigation using a novel hidden maze learning test.

    PubMed

    Pietrzak, Robert H; Cohen, Henri; Snyder, Peter J

    2007-02-01

    This study compared 19 older adults and 20 younger adults on the Groton Maze Learning Test((c)) (GMLT), a novel computerized hidden maze learning test that assesses processing speed, spatial learning efficiency, and error monitoring. Convergent validity of this test was assessed by comparing GMLT scores to Paced Auditory Serial Addition Test (PASAT) and Tower of Toronto (TOT) scores. In the full sample, all GMLT measures correlated strongly with both PASAT and TOT scores (r's=0.53 to 0.73). GMLT measures most sensitive to detecting between-group differences were the Timed Chase Test (TCT), legal errors, and perseverative errors (Cohen's d's=3.81, 2.40, and 2.40, respectively). Scores on the visuomotor processing speed subtest of the GMLT attenuated the relationship between age group and maze efficiency index scores, but not perseverative and "rule-break" errors. These results suggest that normal aging is associated with impaired performance on a novel computerized measure of spatial learning efficiency and error monitoring, and that processing speed attenuates the relationship between age and spatial learning efficiency.

  1. Effects of Head Rotation on Space- and Word-Based Reading Errors in Spatial Neglect

    ERIC Educational Resources Information Center

    Reinhart, Stefan; Keller, Ingo; Kerkhoff, Georg

    2010-01-01

    Patients with right hemisphere lesions often omit or misread words on the left side of a text or the beginning letters of single words which is termed neglect dyslexia (ND). Two types of reading errors are typically observed in ND: omissions and word-based reading errors. The prior are considered as space-based omission errors on the…

  2. [Advances in the studies of concealed penis].

    PubMed

    Fan, Sheng-hai; Li, Xue-de

    2015-09-01

    Concealed penis is usually found in children, which affects the patients both physiologically and psychologically. Some of the patients are wrongly treated by circumcision, which may bring about serious consequences to the sexual life of the patients in their adulthood. In the recent years, this disease has been receiving more and more attention from both doctors and parents. However, controversies remain as to its classification, pathogenesis, pathology, and treatment. This paper focuses on the understanding and advances in the studies of concealed penis.

  3. A large-area, spatially continuous assessment of land cover map error and its impact on downstream analyses.

    PubMed

    Estes, Lyndon; Chen, Peng; Debats, Stephanie; Evans, Tom; Ferreira, Stefanus; Kuemmerle, Tobias; Ragazzo, Gabrielle; Sheffield, Justin; Wolf, Adam; Wood, Eric; Caylor, Kelly

    2017-09-16

    Land cover maps increasingly underlie research into socioeconomic and environmental patterns and processes, including global change. It is known that map errors impact our understanding of these phenomena, but quantifying these impacts is difficult because many areas lack adequate reference data. We used a highly accurate, high-resolution map of South African cropland to assess (1) the magnitude of error in several current generation land cover maps, and (2) how these errors propagate in downstream studies. We first quantified pixel-wise errors in the cropland classes of four widely used land cover maps at resolutions ranging from 1 to 100 km, and then calculated errors in several representative "downstream" (map-based) analyses, including assessments of vegetative carbon stocks, evapotranspiration, crop production, and household food security. We also evaluated maps' spatial accuracy based on how precisely they could be used to locate specific landscape features. We found that cropland maps can have substantial biases and poor accuracy at all resolutions (e.g., at 1 km resolution, up to ∼45% underestimates of cropland (bias) and nearly 50% mean absolute error (MAE, describing accuracy); at 100 km, up to 15% underestimates and nearly 20% MAE). National-scale maps derived from higher-resolution imagery were most accurate, followed by multi-map fusion products. Constraining mapped values to match survey statistics may be effective at minimizing bias (provided the statistics are accurate). Errors in downstream analyses could be substantially amplified or muted, depending on the values ascribed to cropland-adjacent covers (e.g., with forest as adjacent cover, carbon map error was 200%-500% greater than in input cropland maps, but ∼40% less for sparse cover types). The average locational error was 6 km (600%). These findings provide deeper insight into the causes and potential consequences of land cover map error, and suggest several recommendations for land

  4. Every photon counts: improving low, mid, and high-spatial frequency errors on astronomical optics and materials with MRF

    NASA Astrophysics Data System (ADS)

    Maloney, Chris; Lormeau, Jean Pierre; Dumas, Paul

    2016-07-01

    Many astronomical sensing applications operate in low-light conditions; for these applications every photon counts. Controlling mid-spatial frequencies and surface roughness on astronomical optics are critical for mitigating scattering effects such as flare and energy loss. By improving these two frequency regimes higher contrast images can be collected with improved efficiency. Classically, Magnetorheological Finishing (MRF) has offered an optical fabrication technique to correct low order errors as well has quilting/print-through errors left over in light-weighted optics from conventional polishing techniques. MRF is a deterministic, sub-aperture polishing process that has been used to improve figure on an ever expanding assortment of optical geometries, such as planos, spheres, on and off axis aspheres, primary mirrors and freeform optics. Precision optics are routinely manufactured by this technology with sizes ranging from 5-2,000mm in diameter. MRF can be used for form corrections; turning a sphere into an asphere or free form, but more commonly for figure corrections achieving figure errors as low as 1nm RMS while using careful metrology setups. Recent advancements in MRF technology have improved the polishing performance expected for astronomical optics in low, mid and high spatial frequency regimes. Deterministic figure correction with MRF is compatible with most materials, including some recent examples on Silicon Carbide and RSA905 Aluminum. MRF also has the ability to produce `perfectly-bad' compensating surfaces, which may be used to compensate for measured or modeled optical deformation from sources such as gravity or mounting. In addition, recent advances in MRF technology allow for corrections of mid-spatial wavelengths as small as 1mm simultaneously with form error correction. Efficient midspatial frequency corrections make use of optimized process conditions including raster polishing in combination with a small tool size. Furthermore, a novel MRF

  5. A hybrid discontinuous finite element-spectral nodal method for slab-geometry transport problems without spatial truncation error

    SciTech Connect

    Barros, R.C. de

    1995-12-31

    Described here is a hybrid discontinuous finite element-spectral nodal method for slab-geometry one-speed transport problems without spatial truncation error. For the angular approximation the author used a linear discontinuous (LD) expansion for the angular flux inside each of the N elements of a uniform angular grid. This procedure yields the LD{sub N} equations that is solved numerically using the Spectral Green`s Function (SGF) method with the one-node block inversion (NBI) iterative scheme. The SGF method generates numerical solutions for the LD{sub N} equations that are completely free from spatial approximations. Numerical results are given to illustrate the methods accuracy.

  6. Concealed target detection using augmented reality with SIRE radar

    NASA Astrophysics Data System (ADS)

    Saponaro, Philip; Kambhamettu, Chandra; Ranney, Kenneth; Sullivan, Anders

    2013-05-01

    The Synchronous Impulse Reconstruction (SIRE) forward-looking radar, developed by the U.S. Army Research Laboratory (ARL), can detect concealed targets using ultra-wideband synthetic aperture technology. The SIRE radar has been mounted on a Ford Expedition and combined with other sensors, including a pan/tilt/zoom camera, to test its capabilities of concealed target detection in a realistic environment. Augmented Reality (AR) can be used to combine the SIRE radar image with the live camera stream into one view, which provides the user with information that is quicker to assess and easier to understand than each separated. In this paper we present an AR system which utilizes a global positioning system (GPS) and inertial measurement unit (IMU) to overlay a SIRE radar image onto a live video stream. We describe a method for transforming 3D world points in the UTM coordinate system onto the video stream by calibrating for the intrinsic parameters of the camera. This calibration is performed offline to save computation time and achieve real time performance. Since the intrinsic parameters are affected by the zoom of the camera, we calibrate at eleven different zooms and interpolate. We show the results of a real time transformation of the SAR imagery onto the video stream. Finally, we quantify both the 2D error and 3D residue associated with our transformation and show that the amount of error is reasonable for our application.

  7. Complex linear minimum mean-squared-error equalization of spatially quadrature-amplitude-modulated signals in holographic data storage

    NASA Astrophysics Data System (ADS)

    Sato, Takanori; Kanno, Kazutaka; Bunsen, Masatoshi

    2016-09-01

    We applied complex linear minimum mean-squared-error equalization to spatially quadrature-amplitude-modulated signals in holographic data storage (HDS). The equalization technique can improve dispersion in constellation outputs due to intersymbol interference. We confirm the effectiveness of the equalization technique in numerical simulations and basic optical experiments. Our numerical results have shown that intersymbol interference of a retrieved signal in a HDS system can be improved by using the equalization technique. In our experiments, a mean squared error (MSE), which indicates the deviation from an ideal signal, has been used for quantitatively evaluating the dispersion of equalized signals. Our equalization technique has been able to improve the MSE. However, symbols in the equalized signal have remained inseparable. To further improve the MSE and make the symbols separable, reducing errors in repeated measurements is our future task.

  8. Spatial reconstruction by patients with hippocampal damage is dominated by relational memory errors.

    PubMed

    Watson, Patrick D; Voss, Joel L; Warren, David E; Tranel, Daniel; Cohen, Neal J

    2013-07-01

    Hippocampal damage causes profound yet circumscribed memory impairment across diverse stimulus types and testing formats. Here, within a single test format involving a single class of stimuli, we identified different performance errors to better characterize the specifics of the underlying deficit. The task involved study and reconstruction of object arrays across brief retention intervals. The most striking feature of patients' with hippocampal damage performance was that they tended to reverse the relative positions of item pairs within arrays of any size, effectively "swapping" pairs of objects. These "swap errors" were the primary error type in amnesia, almost never occurred in healthy comparison participants, and actually contributed to poor performance on more traditional metrics (such as distance between studied and reconstructed location). Patients made swap errors even in trials involving only a single pair of objects. The selectivity and severity of this particular deficit creates serious challenges for theories of memory and hippocampus.

  9. Quantification of errors in large-eddy simulations of a spatially evolving mixing layer using polynomial chaos

    SciTech Connect

    Meldi, M.; Sagaut, P.; Salvetti, M. V.

    2012-03-15

    A stochastic approach based on generalized polynomial chaos (gPC) is used to quantify the error in large-eddy simulation (LES) of a spatially evolving mixing layer flow and its sensitivity to different simulation parameters, viz., the grid stretching in the streamwise and lateral directions and the subgrid-scale (SGS) Smagorinsky model constant (C{sub S}). The error is evaluated with respect to the results of a highly resolved LES and for different quantities of interest, namely, the mean streamwise velocity, the momentum thickness, and the shear stress. A typical feature of the considered spatially evolving flow is the progressive transition from a laminar regime, highly dependent on the inlet conditions, to a fully developed turbulent one. Therefore, the computational domain is divided in two different zones (inlet dependent and fully turbulent) and the gPC error analysis is carried out for these two zones separately. An optimization of the parameters is also carried out for both these zones. For all the considered quantities, the results point out that the error is mainly governed by the value of the C{sub S} constant. At the end of the inlet-dependent zone, a strong coupling between the normal stretching ratio and the C{sub S} value is observed. The error sensitivity to the parameter values is significantly larger in the inlet-dependent upstream region; however, low-error values can be obtained in this region for all the considered physical quantities by an ad hoc tuning of the parameters. Conversely, in the turbulent regime the error is globally lower and less sensitive to the parameter variations, but it is more difficult to find a set of parameter values leading to optimal results for all the analyzed physical quantities. A similar analysis is also carried out for the dynamic Smagorinsky model, by varying the grid stretching ratios. Comparing the databases generated with the different subgrid-scale models, it is possible to observe that the error cost

  10. Spatial and Temporal Characteristics of Error-Related Activity in the Human Brain

    PubMed Central

    Miezin, Francis M.; Nelson, Steven M.; Dubis, Joseph W.; Dosenbach, Nico U.F.; Schlaggar, Bradley L.; Petersen, Steven E.

    2015-01-01

    A number of studies have focused on the role of specific brain regions, such as the dorsal anterior cingulate cortex during trials on which participants make errors, whereas others have implicated a host of more widely distributed regions in the human brain. Previous work has proposed that there are multiple cognitive control networks, raising the question of whether error-related activity can be found in each of these networks. Thus, to examine error-related activity broadly, we conducted a meta-analysis consisting of 12 tasks that included both error and correct trials. These tasks varied by stimulus input (visual, auditory), response output (button press, speech), stimulus category (words, pictures), and task type (e.g., recognition memory, mental rotation). We identified 41 brain regions that showed a differential fMRI BOLD response to error and correct trials across a majority of tasks. These regions displayed three unique response profiles: (1) fast, (2) prolonged, and (3) a delayed response to errors, as well as a more canonical response to correct trials. These regions were found mostly in several control networks, each network predominantly displaying one response profile. The one exception to this “one network, one response profile” observation is the frontoparietal network, which showed prolonged response profiles (all in the right hemisphere), and fast profiles (all but one in the left hemisphere). We suggest that, in the place of a single localized error mechanism, these findings point to a large-scale set of error-related regions across multiple systems that likely subserve different functions. PMID:25568119

  11. Error Estimation in an Optimal Interpolation Scheme for High Spatial and Temporal Resolution SST Analyses

    NASA Technical Reports Server (NTRS)

    Rigney, Matt; Jedlovec, Gary; LaFontaine, Frank; Shafer, Jaclyn

    2010-01-01

    Heat and moisture exchange between ocean surface and atmosphere plays an integral role in short-term, regional NWP. Current SST products lack both spatial and temporal resolution to accurately capture small-scale features that affect heat and moisture flux. NASA satellite is used to produce high spatial and temporal resolution SST analysis using an OI technique.

  12. A Study on Sixth Grade Students' Misconceptions and Errors in Spatial Measurement: Length, Area, and Volume

    ERIC Educational Resources Information Center

    Tan Sisman, Gulcin; Aksu, Meral

    2016-01-01

    The purpose of the present study was to portray students' misconceptions and errors while solving conceptually and procedurally oriented tasks involving length, area, and volume measurement. The data were collected from 445 sixth grade students attending public primary schools in Ankara, Türkiye via a test composed of 16 constructed-response…

  13. A Study on Sixth Grade Students' Misconceptions and Errors in Spatial Measurement: Length, Area, and Volume

    ERIC Educational Resources Information Center

    Tan Sisman, Gulcin; Aksu, Meral

    2016-01-01

    The purpose of the present study was to portray students' misconceptions and errors while solving conceptually and procedurally oriented tasks involving length, area, and volume measurement. The data were collected from 445 sixth grade students attending public primary schools in Ankara, Türkiye via a test composed of 16 constructed-response…

  14. Automated Human Screening for Detecting Concealed Knowledge

    ERIC Educational Resources Information Center

    Twyman, Nathan W.

    2012-01-01

    Screening individuals for concealed knowledge has traditionally been the purview of professional interrogators investigating a crime. But the ability to detect when a person is hiding important information would be of high value to many other fields and functions. This dissertation proposes design principles for and reports on an implementation…

  15. Detecting concealed objects at a checkpoint

    DOEpatents

    McMakin, Douglas L.; Hall, Thomas E.; Sheen, David M.; Severtsen, Ronald H.

    2008-07-29

    Disclosed are systems, methods, devices, and apparatus to interrogate a clothed individual with electromagnetic radiation to determine if a concealed object is being carried. This determination includes establishing data corresponding to an image of the individual with a pair of opposed, semi-cylindrical array panels each configured to interrogate the individual with electromagnetic radiation in the 200 MHz to 1 THz range.

  16. Concealed Questions. In Search of Answers

    ERIC Educational Resources Information Center

    Frana, Ilaria

    2010-01-01

    This dissertation examines the semantic interpretation of various types of DPs in so-called concealed-question (CQ) constructions, as "Bill's phone number" in the sentence "John knows Bill's phone number". The peculiar characteristic of DP-CQs is that they are interpreted as having the meaning of an embedded question. So, for instance, the…

  17. Concealment of Child Sexual Abuse in Sports

    ERIC Educational Resources Information Center

    Hartill, Mike

    2013-01-01

    When the sexual abuse of children is revealed, it is often found that other nonabusing adults were aware of the abuse but failed to act. During the past twenty years or so, the concealment of child sexual abuse (CSA) within organizations has emerged as a key challenge for child protection work. Recent events at Pennsylvania State University (PSU)…

  18. Concealed Questions. In Search of Answers

    ERIC Educational Resources Information Center

    Frana, Ilaria

    2010-01-01

    This dissertation examines the semantic interpretation of various types of DPs in so-called concealed-question (CQ) constructions, as "Bill's phone number" in the sentence "John knows Bill's phone number". The peculiar characteristic of DP-CQs is that they are interpreted as having the meaning of an embedded question. So, for instance, the…

  19. Modified penoplasty for concealed penis in children.

    PubMed

    Yang, Tianyou; Zhang, Liyu; Su, Cheng; Li, Zhongmin; Wen, Yingquan

    2013-09-01

    To report a modified penoplasty technique for concealed penis in children. Between January 2006 and June 2012, 201 cases of concealed penis were surgically repaired with modified penoplasty. The modified penoplasty technique consisted of 3 major steps: (1) degloved the penile skin and excised the inner prepuce, (2) advanced penoscrotal skin to cover penile shaft, and (3) fixed the penis base and reconstructed the penoscrotal angle. Two hundred one cases of concealed penis were enrolled in this study over a period of 6 years. Mean age at the time of surgery was 5.3 years (range 1-13 years) and mean operative time was 40 minutes (range 30-65minutes). All patients were routinely followed up at 1, 3, and 6 months after surgery. Most patients developed postoperative edema and were resolved within 1 month, whereas 20 cases developed prolonged postoperative edema, especially at the site of frenulum, which took 3 months to be resolved. Ten cases had retraction after surgery. No erection difficulties were recorded. Patients/parents reported better hygiene and improved visualization and accessibility of penis after surgery and were satisfied with the cosmetic outcome. The result of this study shows that the modified penoplasty technique is a simple, safe, and effective procedure for concealed penis with satisfied cosmetic outcome. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Management of concealed penis with modified penoplasty.

    PubMed

    Xu, Jian-Guo; Lv, Chuan; Wang, Yu-Chong; Zhu, Ji; Xue, Chun-Yu

    2015-03-01

    To investigate the effect of penile degloving in combination with penoscrotal angle reconstruction for the correction of concealed penis. A foreskin circumcision incision was made along the coronal sulcus. After a sharp dissection under the superficial layer of tunica albuginea, the penile shaft was degloved to release the fibrous bands of the tunica dartos. Through a longitudinal incision or Z-plasty at the penoscrotal junction, securing of the tunica albuginea to the proximal tunica dartos was performed. The penoscrotal angle was reconstructed. This procedure effectively corrected the concealed penis, while correcting other problems such as phimosis. From August 2008 to August 2013, we performed 41 procedures for concealed penis. Correction was successful in all patients with an improved median length of 2.1 cm in the flaccid state. Follow-up ranged from 6 months to 2 years, and satisfactory cosmetic outcomes were obtained without scars or erectile discomfort. Our technique includes degloving and penoscrotal angle reconstruction, which provides proper visualization for fixation of the penile base. The longitudinal or Z-plasty incision also opened the degloving dead cavity, which was good for drainage. The procedure is straight forward with good functional and cosmetic outcomes and is thus ideal for correction of the concealed penis. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Concealment of Child Sexual Abuse in Sports

    ERIC Educational Resources Information Center

    Hartill, Mike

    2013-01-01

    When the sexual abuse of children is revealed, it is often found that other nonabusing adults were aware of the abuse but failed to act. During the past twenty years or so, the concealment of child sexual abuse (CSA) within organizations has emerged as a key challenge for child protection work. Recent events at Pennsylvania State University (PSU)…

  2. Automated Human Screening for Detecting Concealed Knowledge

    ERIC Educational Resources Information Center

    Twyman, Nathan W.

    2012-01-01

    Screening individuals for concealed knowledge has traditionally been the purview of professional interrogators investigating a crime. But the ability to detect when a person is hiding important information would be of high value to many other fields and functions. This dissertation proposes design principles for and reports on an implementation…

  3. Paraclinoid aneurysm concealed by sphenoid wing meningioma.

    PubMed

    Petrecca, Kevin; Sirhan, Denis

    2009-02-01

    The coexistence of brain tumours and aneurysms is rare. In all previously reported cases the aneurysm was detectable by angiography. We report here a case in which a paraclinoid internal carotid artery aneurysm was coexistent and concealed from angiographic detection by an adjacent parasellar meningioma.

  4. Concealed weapons detection using low-frequency magnetic imaging

    NASA Astrophysics Data System (ADS)

    Zollars, Byron G.; Sallee, Bradley; Durrett, Michael G.; Cruce, Clay; Hallidy, William

    1997-02-01

    Military personnel, law-enforcement officers, and civilians face ever-increasing dangers from persons carrying concealed handguns and other weapons. In direct correspondence with this danger is a need for more sophisticated means of detecting concealed weapons. We have developed a novel concealed-weapons detector based on the principle of low- frequency magnetic imaging. The detector is configured as a portal, and constructs an image of electrically conductive objects transported through it with a potential spatial resolution of approximately 1 inch. Measurements on a breadboard version of the weapons detector have, to date, yielded a resolution of 2 inches. In operation, magnetic dipole radiation, emitted by transmitting antennas in the perimeter of the portal, is scattered from conductive objects and is picked up by receive antennas, also positioned around the portal. With sufficient measurements, each with a different geometry, a solution to the inverse scattering problem can be found. The result is an image of conductive objects in the detector. The detector is sensitive to all metals, semiconductors, and conductive composites. The measured conductivity image formed by the detector is combined with the video signal from a visible CCD camera to form a composite image of persons transiting the detector portal and the conductive objects they are carrying. Accompanying image recognition software could be used to determine the threat level of objects based upon shape, conductivity, and placement on the person of the carrier, and provide cueing, logging, or alarm functions to the operator if suspect weapons are identified. The low- power, low-frequency emissions from the detector are at levels considered safe to humans and medical implants..

  5. Real-time detection of concealed chemical hazards under ambient light conditions using Raman spectroscopy.

    PubMed

    Cletus, Biju; Olds, William; Fredericks, Peter M; Jaatinen, Esa; Izake, Emad L

    2013-07-01

    Current concerns regarding terrorism and international crime highlight the need for new techniques for detecting unknown and hazardous substances. A novel Raman spectroscopy-based technique, spatially offset Raman spectroscopy (SORS), was recently devised for noninvasively probing the contents of diffusely scattering and opaque containers. Here, we demonstrate a modified portable SORS sensor for detecting concealed substances in-field under different background lighting conditions. Samples including explosive precursors, drugs, and an organophosphate insecticide (chemical warfare agent surrogate) were concealed inside diffusely scattering packaging including plastic, paper, and cloth. Measurements were carried out under incandescent and fluorescent light as well as under daylight to assess the suitability of the probe for different real-life conditions. In each case, it was possible to identify the substances against their reference Raman spectra in less than 1 min. The developed sensor has potential for rapid detection of concealed hazardous substances in airports, mail distribution centers, and customs checkpoints.

  6. Student attitudes toward concealed handguns on campus at 2 universities.

    PubMed

    Cavanaugh, Michael R; Bouffard, Jeffrey A; Wells, William; Nobles, Matt R

    2012-12-01

    We examined student support for a policy that would allow carrying of concealed handguns on university campuses. Large percentages of students at 2 universities expressed very low levels of comfort with the idea of permitting concealed handgun carrying on campus, suggesting that students may not welcome less restrictive policies. Students held slightly different opinions about concealed handguns on and off campus, suggesting that they view the campus environment as unique with respect to concealed handgun carrying.

  7. Student Attitudes Toward Concealed Handguns on Campus at 2 Universities

    PubMed Central

    Bouffard, Jeffrey A.; Wells, William; Nobles, Matt R.

    2012-01-01

    We examined student support for a policy that would allow carrying of concealed handguns on university campuses. Large percentages of students at 2 universities expressed very low levels of comfort with the idea of permitting concealed handgun carrying on campus, suggesting that students may not welcome less restrictive policies. Students held slightly different opinions about concealed handguns on and off campus, suggesting that they view the campus environment as unique with respect to concealed handgun carrying. PMID:22720763

  8. Error resiliency of distributed video coding in wireless video communication

    NASA Astrophysics Data System (ADS)

    Ye, Shuiming; Ouaret, Mourad; Dufaux, Frederic; Ansorge, Michael; Ebrahimi, Touradj

    2008-08-01

    Distributed Video Coding (DVC) is a new paradigm in video coding, based on the Slepian-Wolf and Wyner-Ziv theorems. DVC offers a number of potential advantages: flexible partitioning of the complexity between the encoder and decoder, robustness to channel errors due to intrinsic joint source-channel coding, codec independent scalability, and multi-view coding without communications between the cameras. In this paper, we evaluate the performance of DVC in an error-prone wireless communication environment. We also present a hybrid spatial and temporal error concealment approach for DVC. Finally, we perform a comparison with a state-of-the-art AVC/H.264 video coding scheme in the presence of transmission errors.

  9. An Examination of the Spatial Distribution of Carbon Dioxide and Systematic Errors

    NASA Technical Reports Server (NTRS)

    Coffey, Brennan; Gunson, Mike; Frankenberg, Christian; Osterman, Greg

    2011-01-01

    The industrial period and modern age is characterized by combustion of coal, oil, and natural gas for primary energy and transportation leading to rising levels of atmospheric of CO2. This increase, which is being carefully measured, has ramifications throughout the biological world. Through remote sensing, it is possible to measure how many molecules of CO2 lie in a defined column of air. However, other gases and particles are present in the atmosphere, such as aerosols and water, which make such measurements more complicated1. Understanding the detailed geometry and path length of the observation is vital to computing the concentration of CO2. Comparing these satellite readings with ground-truth data (TCCON) the systematic errors arising from these sources can be assessed. Once the error is understood, it can be scaled for in the retrieval algorithms to create a set of data, which is closer to the TCCON measurements1. Using this process, the algorithms are being developed to reduce bias, within.1% worldwide of the true value. At this stage, the accuracy is within 1%, but through correcting small errors contained in the algorithms, such as accounting for the scattering of sunlight, the desired accuracy can be achieved.

  10. An Examination of the Spatial Distribution of Carbon Dioxide and Systematic Errors

    NASA Technical Reports Server (NTRS)

    Coffey, Brennan; Gunson, Mike; Frankenberg, Christian; Osterman, Greg

    2011-01-01

    The industrial period and modern age is characterized by combustion of coal, oil, and natural gas for primary energy and transportation leading to rising levels of atmospheric of CO2. This increase, which is being carefully measured, has ramifications throughout the biological world. Through remote sensing, it is possible to measure how many molecules of CO2 lie in a defined column of air. However, other gases and particles are present in the atmosphere, such as aerosols and water, which make such measurements more complicated1. Understanding the detailed geometry and path length of the observation is vital to computing the concentration of CO2. Comparing these satellite readings with ground-truth data (TCCON) the systematic errors arising from these sources can be assessed. Once the error is understood, it can be scaled for in the retrieval algorithms to create a set of data, which is closer to the TCCON measurements1. Using this process, the algorithms are being developed to reduce bias, within.1% worldwide of the true value. At this stage, the accuracy is within 1%, but through correcting small errors contained in the algorithms, such as accounting for the scattering of sunlight, the desired accuracy can be achieved.

  11. 25 CFR 11.444 - Carrying concealed weapons.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Carrying concealed weapons. 11.444 Section 11.444 Indians... ORDER CODE Criminal Offenses § 11.444 Carrying concealed weapons. A person who goes about in public places armed with a dangerous weapon concealed upon his or her person is guilty of a misdemeanor unless...

  12. The R package "sperrorest" : Parallelized spatial error estimation and variable importance assessment for geospatial machine learning

    NASA Astrophysics Data System (ADS)

    Schratz, Patrick; Herrmann, Tobias; Brenning, Alexander

    2017-04-01

    Computational and statistical prediction methods such as the support vector machine have gained popularity in remote-sensing applications in recent years and are often compared to more traditional approaches like maximum-likelihood classification. However, the accuracy assessment of such predictive models in a spatial context needs to account for the presence of spatial autocorrelation in geospatial data by using spatial cross-validation and bootstrap strategies instead of their now more widely used non-spatial equivalent. The R package sperrorest by A. Brenning [IEEE International Geoscience and Remote Sensing Symposium, 1, 374 (2012)] provides a generic interface for performing (spatial) cross-validation of any statistical or machine-learning technique available in R. Since spatial statistical models as well as flexible machine-learning algorithms can be computationally expensive, parallel computing strategies are required to perform cross-validation efficiently. The most recent major release of sperrorest therefore comes with two new features (aside from improved documentation): The first one is the parallelized version of sperrorest(), parsperrorest(). This function features two parallel modes to greatly speed up cross-validation runs. Both parallel modes are platform independent and provide progress information. par.mode = 1 relies on the pbapply package and calls interactively (depending on the platform) parallel::mclapply() or parallel::parApply() in the background. While forking is used on Unix-Systems, Windows systems use a cluster approach for parallel execution. par.mode = 2 uses the foreach package to perform parallelization. This method uses a different way of cluster parallelization than the parallel package does. In summary, the robustness of parsperrorest() is increased with the implementation of two independent parallel modes. A new way of partitioning the data in sperrorest is provided by partition.factor.cv(). This function gives the user the

  13. An analysis of perceptual errors in reading mammograms using quasi-local spatial frequency spectra.

    PubMed

    Mello-Thoms, C; Dunn, S M; Nodine, C F; Kundel, H L

    2001-09-01

    In this pilot study the authors examined areas on a mammogram that attracted the visual attention of experienced mammographers and mammography fellows, as well as areas that were reported to contain a malignant lesion, and, based on their spatial frequency spectrum, they characterized these areas by the type of decision outcome that they yielded: true-positives (TP), false-positives (FP), true-negatives (TN), and false-negatives (FN). Five 2-view (craniocaudal and medial-lateral oblique) mammogram cases were examined by 8 experienced observers, and the eye position of the observers was tracked. The observers were asked to report the location and nature of any malignant lesions present in the case. The authors analyzed each area in which either the observer made a decision or in which the observer had prolonged (>1,000 ms) visual dwell using wavelet packets, and characterized these areas in terms of the energy contents of each spatial frequency band. It was shown that each decision outcome is characterized by a specific profile in the spatial frequency domain, and that these profiles are significantly different from one another. As a consequence of these differences, the profiles can be used to determine which type of decision a given observer will make when examining the area. Computer-assisted perception correctly predicted up to 64% of the TPs made by the observers, 77% of the FPs, and 70% of the TNs.

  14. Further investigations on fixed abrasive diamond pellets used for diminishing mid-spatial frequency errors of optical mirrors.

    PubMed

    Dong, Zhichao; Cheng, Haobo; Tam, Hon-Yuen

    2014-01-20

    As further application investigations on fixed abrasive diamond pellets (FADPs), this work exhibits their potential capability for diminishing mid-spatial frequency errors (MSFEs, i.e., periodic small structure) of optical surfaces. Benefitting from its high surficial rigidness, the FADPs tool has a natural smoothing effect to periodic small errors. Compared with the previous design, this proposed new tool employs more compliance to aspherical surfaces due to the pellets being mutually separated and bonded on a steel plate with elastic back of silica rubber adhesive. Moreover, a unicursal Peano-like path is presented for improving MSFEs, which can enhance the multidirectionality and uniformity of the tool's motion. Experiments were conducted to validate the effectiveness of FADPs for diminishing MSFEs. In the lapping of a Φ=420 mm Zerodur paraboloid workpiece, the grinding ripples were quickly diminished (210 min) by both visual inspection and profile metrology, as well as the power spectrum density (PSD) analysis, RMS was reduced from 4.35 to 0.55 μm. In the smoothing of a Φ=101 mm fused silica workpiece, MSFEs were obviously improved from the inspection of surface form maps, interferometric fringe patterns, and PSD analysis. The mid-spatial frequency RMS was diminished from 0.017λ to 0.014λ (λ=632.8 nm).

  15. Spatial Support Vector Regression to Detect Silent Errors in the Exascale Era

    SciTech Connect

    Subasi, Omer; Di, Sheng; Bautista-Gomez, Leonardo; Balaprakash, Prasanna; Unsal, Osman; Labarta, Jesus; Cristal, Adrian; Cappello, Franck

    2016-01-01

    As the exascale era approaches, the increasing capacity of high-performance computing (HPC) systems with targeted power and energy budget goals introduces significant challenges in reliability. Silent data corruptions (SDCs) or silent errors are one of the major sources that corrupt the executionresults of HPC applications without being detected. In this work, we explore a low-memory-overhead SDC detector, by leveraging epsilon-insensitive support vector machine regression, to detect SDCs that occur in HPC applications that can be characterized by an impact error bound. The key contributions are three fold. (1) Our design takes spatialfeatures (i.e., neighbouring data values for each data point in a snapshot) into training data, such that little memory overhead (less than 1%) is introduced. (2) We provide an in-depth study on the detection ability and performance with different parameters, and we optimize the detection range carefully. (3) Experiments with eight real-world HPC applications show thatour detector can achieve the detection sensitivity (i.e., recall) up to 99% yet suffer a less than 1% of false positive rate for most cases. Our detector incurs low performance overhead, 5% on average, for all benchmarks studied in the paper. Compared with other state-of-the-art techniques, our detector exhibits the best tradeoff considering the detection ability and overheads.

  16. Characteristics of women who deny or conceal pregnancy.

    PubMed

    Friedman, Susan Hatters; Heneghan, Amy; Rosenthal, Miriam

    2007-01-01

    In order to assess characteristics of women with denial or concealment of pregnancy until delivery, the authors conducted a retrospective study of women with no history of prenatal care who presented to their institution for delivery or immediately postpartum. Among these women, 29% had denied pregnancy, and 9% had concealed pregnancy. Authors constructed models predicting denial or concealment of pregnancy and further elucidated subtypes of denial and concealment of pregnancy. Strikingly, psychiatric consultation was rare for women who had denied or concealed their pregnancies, and yet they would often subsequently take responsibility for their infants.

  17. Using scratch card technology for random allocation concealment in a clinical trial with a crossover design.

    PubMed

    Beksinska, Mags E; Joanis, Carol; Smit, Jenni A; Pienaar, Jacqueline; Piaggio, Gilda

    2013-02-01

    To avoid selection bias in clinical trials, random allocation concealment is crucial to ensure that participants and or researchers remain unaware of assignments. We aimed to design an allocation concealment method that reduced the possibility of selection bias for a randomized, open-label, crossover trial to evaluate device function of four female condom (FC) types. Using scratch card technology, we devised a simple method of concealment, whereby the treatment sequence was printed on a single card for each participant, and the codes for each treatment in the sequence were concealed beneath foil squares on a stiff A6-sized card. On the first and subsequent follow-up visits, the foil corresponding to that visit was scratched from the square to reveal the condom type allocation for the next condom-use period. Staff in the South African and Chinese trial sites were trained in use and care of the card, and on completion of the study completed a questionnaire on their experience of use. Research staff in both countries found the card easy to use and those who had previously used the sequentially numbered, opaque, sealed envelopes (SNOSE) system for random allocation reported the scratch card easier to use. Research staff most commonly used a coin to remove the foil square and some used their fingernails. In both South Africa and China, no errors in allocation sequence were found during study monitoring. Scratch card system of allocation cannot be printed in-house. This novel, effective method of concealment for a crossover random allocation was well liked by study staff. The most important advantage of this method is the ability to conceal consecutive allocations of a crossover design using a single card, thus eliminating the need for multiple envelopes per participant. While we used this method in a clinical trial of FCs, it could be employed in a range of other clinical trials and other randomized studies.

  18. Passive millimeter-wave concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Sinclair, Gordon N.; Anderton, Rupert N.; Appleby, Roger

    2001-02-01

    A method of detecting weapons concealed under clothing using passive millimeter wave imaging is described. The optical properties of clothing are discussed and examples given of the spectral reflectivity and transmission. The transmission tends to be constant from 60 to 150 GHz above which it decreases for some clothing materials. The transmission of a cotton T-shirt is typically 95% and of a leather jacket up to 85% at lower frequencies. A model is presented for calculating the contrast of a metallic concealed weapon when hidden under clothing and it indicates contrasts as large as 200 K can be realized outdoors. The advantages of real time over static frame imagery are discussed. It is concluded that real time imagery offers considerable advantages as weapons can be very varied in size, position and orientation and movement offers vital clues to the human observer which aid the recognition process.

  19. Induction detection of concealed bulk banknotes

    NASA Astrophysics Data System (ADS)

    Fuller, Christopher; Chen, Antao

    2012-06-01

    The smuggling of bulk cash across borders is a serious issue that has increased in recent years. In an effort to curb the illegal transport of large numbers of paper bills, a detection scheme has been developed, based on the magnetic characteristics of bank notes. The results show that volumes of paper currency can be detected through common concealing materials such as plastics, cardboard, and fabrics making it a possible potential addition to border security methods. The detection scheme holds the potential of also reducing or eliminating false positives caused by metallic materials found in the vicinity, by observing the stark difference in received signals caused by metal and currency. The detection scheme holds the potential to detect for both the presence and number of concealed bulk notes, while maintaining the ability to reduce false positives caused by metal objects.

  20. Medical makeup for concealing facial scars.

    PubMed

    Mee, Donna; Wong, Brian J F

    2012-10-01

    Surgical, laser, and pharmacological therapies are all used to correct scars and surgical incisions, though have limits with respect to how well facial skin can be restored or enhanced. The use of cosmetics has long been a relevant adjunct to all scar treatment modalities. In recent years, technical advancements in the chemistry and composition of cosmetic products have provided the patient with a broader range of products to employ for concealing scars. This review will provide an overview of contemporary methods for concealing facial scars, birthmarks, and pigmentary changes without the use of traditional/dated, heavy appearing camouflage products. Additionally, general guidelines and information will be provided with respect to identifying competent makeup artists for care of the medical patient. The article by no means is meant to be a tutorial, but rather serves as a starting point in this allied field of medicine. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  1. Concealed evaporite basin drilled in Arizona

    SciTech Connect

    Rauzi, S.L.

    1996-10-21

    The White Mountains of Arizona are a high forested plateau underlain by volcanic rocks of Late Pliocene and Quaternary age on the south margin of the Colorado plateau province. Elevations range from 6,000--11,590 ft, with winter snow and summer rain but ideal conditions for much of the year. There was no evidence of a Permian evaporite basin concealed beneath the White Mountain volcanic field until 1993, when the Tonto 1 Alpine-Federal, a geothermal test well, was drilled. This test did not encounter thermal waters, but it did encounter a surprisingly thick and unexpected sequence of anhydrite, dolomite, and petroliferous limestone assigned to the Supai (Yeso) formation of Permian age. The Tonto test was continuously cored through the Permian section, providing invaluable information that is now stored at the Arizona Geological Survey in Tucson. The paper describes the area geology and the concealed basin.

  2. Concealed weapons detection using electromagnetic resonances

    NASA Astrophysics Data System (ADS)

    Hunt, Allen R.; Hogg, R. Douglas; Foreman, William

    1998-12-01

    Concealed weapons pose a significant threat to both law enforcement and security agency personnel. The uncontrolled environments associated with peacekeeping and the move toward relaxation of concealed weapons laws here in the U.S. provide a strong motivation for developing weapons detection technologies which are noninvasive and can function noncooperatively. Existing weapons detection systems are primarily oriented to detecting metal and require the cooperation of the person being searched. The new generation of detectors under development that focuses primarily on imaging methods, faces problems associated with privacy issues. There remains a need for a weapons detector which is portable, detects weapons remotely, avoids the issues associated with privacy rights, can tell the difference between car keys and a knife, and is affordable enough that one can be issued to every peacekeeper and law enforcement officer. AKELA is developing a concealed weapons detector that uses wideband radar techniques to excite natural electromagnetic resonances that characterize the size, shape, and material composition of an object. Neural network processing is used to classify the difference between weapons and nuisance objects. We have constructed both time and frequency domain test systems and used them to gather experimental data on a variety of armed and unarmed individuals. These experiments have been performed in an environment similar to the operational environment. Preliminary results from these experiments show that it is possible to detect a weapon being carried by an individual from a distance of 10 to 15 feet, and to detect a weapon being concealed behind the back. The power required is about 100 milliwatts. A breadboard system is being fabricated and will be used by AKELA and our law enforcement partner to gather data in operationally realistic situations. While a laptop computer will control the breadboard system, the wideband radar electronics will fit in a box the

  3. Imaging sensor fusion for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Currie, Nicholas C.; Demma, Fred J.; Ferris, David D., Jr.; McMillan, Robert W.; Wicks, Michael C.; Zyga, Kathleen

    1997-02-01

    Sensors are needed for concealed weapon detection which perform better with regard to weapon classification, identification, probability of detection and false alarm rate than the magnetic sensors commonly used in airports. We have concluded that no single sensor will meet the requirements for a reliable concealed weapon detector and thus that sensor fusion is required to optimize detection probability and false alarm rate by combining sensor outputs in a synergistic fashion. This paper describes microwave, millimeter wave, far infrared, infrared, x-ray, acoustic, and magnetic sensors which have some promise in the field of concealed weapon detection. The strengths and weaknesses of these devices are discussed, and examples of the outputs of most of them are given. Various approaches to fusion of these sensors are also described, from simple cuing of one sensor by another to improvement of image quality by using multiple systems. It is further concluded that none of the sensors described herein will ever replace entirely the airport metal detector, but that many of them meet needs imposed by applications requiring a higher detection probability and lower false alarm rate.

  4. Error analysis of standard wave-front reconstruction based on spatial light modulator

    NASA Astrophysics Data System (ADS)

    Ma, Xiao; Liu, Shijie; Zhang, Zhigang; Shao, Jianda

    2016-10-01

    The invention of spatial light modulator (SLM) promotes the development of aspheric surface test. SLM has the advantage of real-time and low-cost in comparison with the etching computer-generated hologram(CGH) plate. The pixel-structure of SLM, which includes the pixel pitch, gray-level number and black matrix, has great significance on the reconstructed wave-front quality. In this paper, the effects of SLM pixel pitch, gray-level number and black matrix are analyzed by Fresnel diffraction theory and computer simulation. In the simulation, a concave spherical wave-front with a radius of 1000 mm is generated by the SLM with different pixel pitch, gray-level numbers and aperture ratios, respectively. The results show that the quality of the reconstructed wave-front gets poorer as the pixel pitch increases, the gray-level number decreases or the aperture ratio reduces. This work can guide the selection of the SLM in the aspheric surface test.

  5. An analytic solution method for discrete ordinates transport equations in slab geometry with no spatial truncation error

    SciTech Connect

    Hong, S.G.; Cho, N.Z.

    1999-07-01

    Recently, some authors have devised exact methods with no spatial truncation error for solving the slab geometry discrete ordinates problems. First, Barros and Larsen developed the spectral Green's function (SGF) method where an exact relation between cell-edge and cell-average angular fluxes is derived by using a spectral analysis (i.e., obtaining eigenfunctions). Second, a direct method was developed by using the Laplace transform. More generally in continuous angle, the Fourier transform and inversion were used to provide analytical benchmark solutions. While motivated by Ref. 1, the authors present a new method that gives exact solutions (with no spatial truncation error) of the one-group discrete ordinates transport equations in slab geometry. The method is based on the infinite medium Green's function (IMGF) and Placzek's lemma. The IMGF is derived analytically by spectral analysis. The method yields concise equations resulting in an economical algorithm. The method does not require a set of intermediary parameters that are used in the SGF method and should be solved numerically from a system of linear equations. The unknowns are cell-edge angular fluxes in the present method, whereas in the SGF method there are two types of unknowns: cell-edge and cell-average angular fluxes. In addition, the present method easily allows the source to be distributed arbitrarily in space. Once the final equation for cell-edge angular fluxes is solved, the analytic solution is easily represented in terms of the cell-edge angular fluxes. The numerical results show that the method gives exact solutions of the discrete ordinates equations, independent of mesh size.

  6. Identifying GRACE+GOCE Combination Gravity Field Error Introduced in Geodetic MDT Using Local Fourier 2D Spatial Spectra

    NASA Astrophysics Data System (ADS)

    Pie, N.; Bettadpur, S. V.; Giuliani, S.

    2016-12-01

    The gravity missions GRACE (Gravity Recovery And Climate Experiment) and GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) have brought great improvements in the study of Earth Dynamic processes. Though they are very different in nature, the two missions provide very complementary gravity products, expressed in the form of spherical harmonic expansions. GOCE, a single satellite mission, relies on a very sensitive Electrostatic Gravity Gradiometer (EGG) composed of 6 accelerometers out of which 6 gravity gradients are computed. On the other hand, GRACE observations of the gravity field are based on a microwave ranging system between its two satellites. The complementarity of the two missions comes from the fact that GRACE gravity products have superior accuracy in the estimation of the low to medium degree terms, while GOCE prevails in the higher degrees. Several combination gravity fields already make use of this complementarity. However, detailed quality analysis of this products reveals characteristic errors in gravity fields resulting in North-South striations, or even small-scale bumpy patterns over the ocean. It is believed that the striations are likely to be attributed to the GRACE data at degree superior to 100 of the spherical harmonic expansion, while the bumpy pattern could be the results of non-optimal weighting at degrees where GRACE and GOCE's accuracy are commensurate. The focus of this study is to characterize the geoid error in GRACE+GOCE combination gravity models in the spatial domain and in the context of the determination of the Mean Dynamic Topography (MDT).

  7. Monte carlo method for the uncertainty evaluation of spatial straightness error based on new generation geometrical product specification

    NASA Astrophysics Data System (ADS)

    Wen, Xiulan; Xu, Youxiong; Li, Hongsheng; Wang, Fenglin; Sheng, Danghong

    2012-09-01

    Straightness error is an important parameter in measuring high-precision shafts. New generation geometrical product specification(GPS) requires the measurement uncertainty characterizing the reliability of the results should be given together when the measurement result is given. Nowadays most researches on straightness focus on error calculation and only several research projects evaluate the measurement uncertainty based on "The Guide to the Expression of Uncertainty in Measurement(GUM)". In order to compute spatial straightness error(SSE) accurately and rapidly and overcome the limitations of GUM, a quasi particle swarm optimization(QPSO) is proposed to solve the minimum zone SSE and Monte Carlo Method(MCM) is developed to estimate the measurement uncertainty. The mathematical model of minimum zone SSE is formulated. In QPSO quasi-random sequences are applied to the generation of the initial position and velocity of particles and their velocities are modified by the constriction factor approach. The flow of measurement uncertainty evaluation based on MCM is proposed, where the heart is repeatedly sampling from the probability density function(PDF) for every input quantity and evaluating the model in each case. The minimum zone SSE of a shaft measured on a Coordinate Measuring Machine(CMM) is calculated by QPSO and the measurement uncertainty is evaluated by MCM on the basis of analyzing the uncertainty contributors. The results show that the uncertainty directly influences the product judgment result. Therefore it is scientific and reasonable to consider the influence of the uncertainty in judging whether the parts are accepted or rejected, especially for those located in the uncertainty zone. The proposed method is especially suitable when the PDF of the measurand cannot adequately be approximated by a Gaussian distribution or a scaled and shifted t-distribution and the measurement model is non-linear.

  8. A novel technique of concealed penis repair.

    PubMed

    Kim, Jung Jun; Lee, Dong-Gi; Park, Kwan Hyun; Baek, Minki

    2014-04-01

    The correction of concealed penis requires challenging surgical techniques. We describe a novel technique involving inner preputial skin substitution after degloving through a ventral approach that allows sufficient penile skin coverage and evaluated the efficacy and safety of our technique. From February 2009 to March 2009, 12 boys with concealed penises underwent correction via our novel technique. We administered a questionnaire about penile size, morphology, and voiding status to parents to evaluate their satisfaction with the results. The mean age of patients at the time of operation was 4.71 ± 4.01 years, and the mean duration of follow-up was 5.11 ± 1.45 months. Parental satisfaction grades (0 to 4) concerning penile size increased from 1.00 ± 1.04 to 2.83 ± 0.94 (p = 0.002) after surgery, penile morphology from 1.00 ± 0.95 to 3.00 ± 0.85 (p = 0.001), and voiding status from 1.08 ± 1.00 to 3.33 ± 0.78 (p < 0.001) at the last follow-up visit. The parental satisfaction rates regarding postoperative changes in size and morphology were 83.3 and 91.7%, respectively. Nine parents (75%) said they would recommend the surgery to others. There were no complications, including postoperative hematoma, infection, and tissue necrosis. Our method of correcting concealed penis was demonstrated to be technically feasible and safe. It provides a good cosmetic appearance and excellent parental satisfaction ratings regarding size, morphology, and voiding function. Georg Thieme Verlag KG Stuttgart · New York.

  9. Detecting persons concealed in a vehicle

    DOEpatents

    Tucker, Jr., Raymond W.

    2005-03-29

    An improved method for detecting the presence of humans or animals concealed within in a vehicle uses a combination of the continuous wavelet transform and a ratio-based energy calculation to determine whether the motion detected using seismic sensors placed on the vehicle is due to the presence of a heartbeat within the vehicle or is the result of motion caused by external factors such as the wind. The method performs well in the presence of light to moderate ambient wind levels, producing far fewer false alarm indications. The new method significantly improves the range of ambient environmental conditions under which human presence detection systems can reliably operate.

  10. Failure to paint the left quarter of a watercolor and no error in a line drawing: a case report of an art teacher with unilateral spatial neglect.

    PubMed

    Kondo, Minako; Mori, Toshiko; Makino, Kenichiro; Okazaki, Tetsuya; Hachisuka, Kenji

    2012-06-01

    A 54-year-old art teacher, experienced a right putaminal hemorrhage, and thereafter suffered severe left hemiplegia and unilateral spatial neglect, and was transferred to the rehabilitation department of the University Hospital 1 month after the onset. Although the unilateral spatial neglect was improving, the patient was unable to paint the left quarter of a watercolor, but there was no error in line drawing. The occurrence of errors only in a watercolor suggests that the neural process for painting a watercolor is different from that of line drawing.

  11. Spatial and temporal variability of the overall error of National Atmospheric Deposition Program measurements determined by the USGS collocated-sampler program, water years 1989-2001.

    PubMed

    Wetherbee, Gregory A; Latysh, Natalie E; Gordon, John D

    2005-06-01

    Data from the U.S. Geological Survey (USGS) collocated-sampler program for the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) are used to estimate the overall error of NADP/NTN measurements. Absolute errors are estimated by comparison of paired measurements from collocated instruments. Spatial and temporal differences in absolute error were identified and are consistent with longitudinal distributions of NADP/NTN measurements and spatial differences in precipitation characteristics. The magnitude of error for calcium, magnesium, ammonium, nitrate, and sulfate concentrations, specific conductance, and sample volume is of minor environmental significance to data users. Data collected after a 1994 sample-handling protocol change are prone to less absolute error than data collected prior to 1994. Absolute errors are smaller during non-winter months than during winter months for selected constituents at sites where frozen precipitation is common. Minimum resolvable differences are estimated for different regions of the USA to aid spatial and temporal watershed analyses.

  12. Spatial and temporal variability of the overall error of National Atmospheric Deposition Program measurements determined by the USGS collocated-sampler program, water years 1989-2001

    USGS Publications Warehouse

    Wetherbee, G.A.; Latysh, N.E.; Gordon, J.D.

    2005-01-01

    Data from the U.S. Geological Survey (USGS) collocated-sampler program for the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) are used to estimate the overall error of NADP/NTN measurements. Absolute errors are estimated by comparison of paired measurements from collocated instruments. Spatial and temporal differences in absolute error were identified and are consistent with longitudinal distributions of NADP/NTN measurements and spatial differences in precipitation characteristics. The magnitude of error for calcium, magnesium, ammonium, nitrate, and sulfate concentrations, specific conductance, and sample volume is of minor environmental significance to data users. Data collected after a 1994 sample-handling protocol change are prone to less absolute error than data collected prior to 1994. Absolute errors are smaller during non-winter months than during winter months for selected constituents at sites where frozen precipitation is common. Minimum resolvable differences are estimated for different regions of the USA to aid spatial and temporal watershed analyses.

  13. 25 CFR 11.444 - Carrying concealed weapons.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Carrying concealed weapons. 11.444 Section 11.444 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Criminal Offenses § 11.444 Carrying concealed weapons. A person who goes about in public...

  14. 25 CFR 11.444 - Carrying concealed weapons.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Carrying concealed weapons. 11.444 Section 11.444 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Criminal Offenses § 11.444 Carrying concealed weapons. A person who goes about in public...

  15. 25 CFR 11.444 - Carrying concealed weapons.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Carrying concealed weapons. 11.444 Section 11.444 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Criminal Offenses § 11.444 Carrying concealed weapons. A person who goes about in public...

  16. 25 CFR 11.444 - Carrying concealed weapons.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Carrying concealed weapons. 11.444 Section 11.444 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Criminal Offenses § 11.444 Carrying concealed weapons. A person who goes about in public...

  17. The approaches to measuring the potential spatial access to urban health services revisited: distance types and aggregation-error issues.

    PubMed

    Apparicio, Philippe; Gelb, Jérémy; Dubé, Anne-Sophie; Kingham, Simon; Gauvin, Lise; Robitaille, Éric

    2017-08-23

    The potential spatial access to urban health services is an important issue in health geography, spatial epidemiology and public health. Computing geographical accessibility measures for residential areas (e.g. census tracts) depends on a type of distance, a method of aggregation, and a measure of accessibility. The aim of this paper is to compare discrepancies in results for the geographical accessibility of health services computed using six distance types (Euclidean and Manhattan distances; shortest network time on foot, by bicycle, by public transit, and by car), four aggregation methods, and fourteen accessibility measures. To explore variations in results according to the six types of distance and the aggregation methods, correlation analyses are performed. To measure how the assessment of potential spatial access varies according to three parameters (type of distance, aggregation method, and accessibility measure), sensitivity analysis (SA) and uncertainty analysis (UA) are conducted. First, independently of the type of distance used except for shortest network time by public transit, the results are globally similar (correlation >0.90). However, important local variations in correlation between Cartesian and the four shortest network time distances are observed, notably in suburban areas where Cartesian distances are less precise. Second, the choice of the aggregation method is also important: compared with the most accurate aggregation method, accessibility measures computed from census tract centroids, though not inaccurate, yield important measurement errors for 10% of census tracts. Third, the SA results show that the evaluation of potential geographic access may vary a great deal depending on the accessibility measure and, to a lesser degree, the type of distance and aggregation method. Fourth, the UA results clearly indicate areas of strong uncertainty in suburban areas, whereas central neighbourhoods show lower levels of uncertainty. In order to

  18. Induction detection of concealed bulk banknotes

    NASA Astrophysics Data System (ADS)

    Fuller, Christopher; Chen, Antao

    2011-10-01

    Bulk cash smuggling is a serious issue that has grown in volume in recent years. By building on the magnetic characteristics of paper currency, induction sensing is found to be capable of quickly detecting large masses of banknotes. The results show that this method is effective in detecting bulk cash through concealing materials such as plastics, cardboards, fabrics and aluminum foil. The significant difference in the observed phase between the received signals caused by conducting materials and ferrite compounds, found in banknotes, provides a good indication that this process can overcome the interference by metal objects in a real sensing application. This identification strategy has the potential to not only detect the presence of banknotes, but also the number, while still eliminating false positives caused by metal objects.

  19. Concealed semantic and episodic autobiographical memory electrified

    PubMed Central

    Ganis, Giorgio; Schendan, Haline E.

    2013-01-01

    Electrophysiology-based concealed information tests (CIT) try to determine whether somebody possesses concealed information about a crime-related item (probe) by comparing event-related potentials (ERPs) between this item and comparison items (irrelevants). Although the broader field is sometimes referred to as “memory detection,” little attention has been paid to the precise type of underlying memory involved. This study begins addressing this issue by examining the key distinction between semantic and episodic memory in the autobiographical domain within a CIT paradigm. This study also addresses the issue of whether multiple repetitions of the items over the course of the session habituate the brain responses. Participants were tested in a 3-stimulus CIT with semantic autobiographical probes (their own date of birth) and episodic autobiographical probes (a secret date learned just before the study). Results dissociated these two memory conditions on several ERP components. Semantic probes elicited a smaller frontal N2 than episodic probes, consistent with the idea that the frontal N2 decreases with greater pre-existing knowledge about the item. Likewise, semantic probes elicited a smaller central N400 than episodic probes. Semantic probes also elicited a larger P3b than episodic probes because of their richer meaning. In contrast, episodic probes elicited a larger late positive complex (LPC) than semantic probes, because of the recent episodic memory associated with them. All these ERPs showed a difference between probes and irrelevants in both memory conditions, except for the N400, which showed a difference only in the semantic condition. Finally, although repetition affected the ERPs, it did not reduce the difference between probes and irrelevants. These findings show that the type of memory associated with a probe has both theoretical and practical importance for CIT research. PMID:23355816

  20. Color image fusion for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Toet, Alexander

    2003-09-01

    Recent advances in passive and active imaging sensor technology offer the potential to detect weapons that are concealed underneath a person's clothing or carried along in bags. Although the concealed weapons can sometimes easily be detected, it can be difficult to perceive their context, due to the non-literal nature of these images. Especially for dynamic crowd surveillance purposes it may be impossible to rapidly asses with certainty which individual in the crowd is the one carrying the observed weapon. Sensor fusion is an enabling technology that may be used to solve this problem. Through fusion the signal of the sensor that depicts the weapon can be displayed in the context provided by a sensor of a different modality. We propose an image fusion scheme in which non-literal imagery can be fused with standard color images such that the result clearly displays the observed weapons in the context of the original color image. The procedure is such that the relevant contrast details from the non-literal image are transferred to the color image without altering the original color distribution of this image. The result is a natural looking color image that fluently combines all details from both input sources. When an observer who performs a dynamic crowd surveillance task, detects a weapon in the scene, he will also be able to quickly determine which person in the crowd is actually carrying the observed weapon (e.g. "the man with the red T-shirt and blue jeans"). The method is illustrated by the fusion of thermal 8-12 μm imagery with standard RGB color images.

  1. Concealing Concealment: The Mediating Role of Internalized Heterosexism in Psychological Distress Among Lesbian, Gay, and Bisexual Older Adults.

    PubMed

    Hoy-Ellis, Charles P

    2016-01-01

    Recent population-based studies indicate that sexual minorities aged 50 and older experience significantly higher rates of psychological distress than their heterosexual age-peers. The minority stress model has been useful in explaining disparately high rates of psychological distress among younger sexual minorities. The purpose of this study is to test a hypothesized structural relationship between two minority stressors--internalized heterosexism and concealment of sexual orientation--and consequent psychological distress among a sample of 2,349 lesbian, gay, and bisexual adults aged 50 to 95 years old. Structural equation modeling indicates that concealment has a nonsignificant direct effect on psychological distress but a significant indirect effect that is mediated through internalized heterosexism; the effect of concealment is itself concealed. This may explain divergent results regarding the role of concealment in psychological distress in other studies, and the implications will be discussed.

  2. Concealing Concealment: The Mediating Role of Internalized Heterosexism in Psychological Distress Among Lesbian, Gay, and Bisexual Older Adults

    PubMed Central

    Hoy-Ellis, Charles P.

    2016-01-01

    Recent population-based studies indicate that sexual minorities aged 50 and older experience significantly higher rates of psychological distress than their heterosexual age-peers. The minority stress model has been useful in explaining disparately high rates of psychological distress among younger sexual minorities. The purpose of this study is to test a hypothesized structural relationship between two minority stressors—internalized heterosexism and concealment of sexual orientation—and consequent psychological distress among a sample of 2,349 lesbian, gay, and bisexual adults aged 50 to 95 years old. Structural equation modeling indicates that concealment has a nonsignificant direct effect on psychological distress but a significant indirect effect that is mediated through internalized heterosexism; the effect of concealment is itself concealed. This may explain divergent results regarding the role of concealment in psychological distress in other studies, and the implications will be discussed. PMID:26322654

  3. Bit error rate analysis of free-space optical system with spatial diversity over strong atmospheric turbulence channel with pointing errors

    NASA Astrophysics Data System (ADS)

    Krishnan, Prabu; Sriram Kumar, D.

    2014-12-01

    Free-space optical communication (FSO) is emerging as a captivating alternative to work out the hindrances in the connectivity problems. It can be used for transmitting signals over common lands and properties that the sender or receiver may not own. The performance of an FSO system depends on the random environmental conditions. The bit error rate (BER) performance of differential phase shift keying FSO system is investigated. A distributed strong atmospheric turbulence channel with pointing error is considered for the BER analysis. Here, the system models are developed for single-input, single-output-FSO (SISO-FSO) and single-input, multiple-output-FSO (SIMO-FSO) systems. The closed-form mathematical expressions are derived for the average BER with various combining schemes in terms of the Meijer's G function.

  4. Concealable Stigmatized Identities and Psychological Well-Being

    PubMed Central

    Quinn, Diane M.; Earnshaw, Valerie A.

    2013-01-01

    Many people have concealable stigmatized identities: Identities that can be hidden from others and that are socially devalued and negatively stereotyped. Understanding how these concealable stigmatized identities affect psychological well-being is critical. We present our model of the components of concealable stigmatized identities including valenced content – internalized stigma, experienced discrimination, anticipated stigma, disclosure reactions, and counter-stereotypic/positive information – and magnitude – centrality and salience. Research has shown that negatively valenced content is related to increased psychological distress. However, smaller identity magnitude may buffer this distress. We review the research available and discuss important areas for future work. PMID:23730326

  5. Concealed identification symbols and nondestructive determination of the identification symbols

    DOEpatents

    Nance, Thomas A.; Gibbs, Kenneth M.

    2014-09-16

    The concealing of one or more identification symbols into a target object and the subsequent determination or reading of such symbols through non-destructive testing is described. The symbols can be concealed in a manner so that they are not visible to the human eye and/or cannot be readily revealed to the human eye without damage or destruction of the target object. The identification symbols can be determined after concealment by e.g., the compilation of multiple X-ray images. As such, the present invention can also provide e.g., a deterrent to theft and the recovery of lost or stolen objects.

  6. Approach trajectory planning system for maximum concealment

    NASA Technical Reports Server (NTRS)

    Warner, David N., Jr.

    1986-01-01

    A computer-simulation study was undertaken to investigate a maximum concealment guidance technique (pop-up maneuver), which military aircraft may use to capture a glide path from masked, low-altitude flight typical of terrain following/terrain avoidance flight enroute. The guidance system applied to this problem is the Fuel Conservative Guidance System. Previous studies using this system have concentrated on the saving of fuel in basically conventional land and ship-based operations. Because this system is based on energy-management concepts, it also has direct application to the pop-up approach which exploits aircraft performance. Although the algorithm was initially designed to reduce fuel consumption, the commanded deceleration is at its upper limit during the pop-up and, therefore, is a good approximation of a minimum-time solution. Using the model of a powered-lift aircraft, the results of the study demonstrated that guidance commands generated by the system are well within the capability of an automatic flight-control system. Results for several initial approach conditions are presented.

  7. Evaluation and error apportionment of an ensemble of atmospheric chemistry transport modeling systems: multivariable temporal and spatial breakdown

    NASA Astrophysics Data System (ADS)

    Solazzo, Efisio; Bianconi, Roberto; Hogrefe, Christian; Curci, Gabriele; Tuccella, Paolo; Alyuz, Ummugulsum; Balzarini, Alessandra; Baró, Rocío; Bellasio, Roberto; Bieser, Johannes; Brandt, Jørgen; Christensen, Jesper H.; Colette, Augistin; Francis, Xavier; Fraser, Andrea; Garcia Vivanco, Marta; Jiménez-Guerrero, Pedro; Im, Ulas; Manders, Astrid; Nopmongcol, Uarporn; Kitwiroon, Nutthida; Pirovano, Guido; Pozzoli, Luca; Prank, Marje; Sokhi, Ranjeet S.; Unal, Alper; Yarwood, Greg; Galmarini, Stefano

    2017-02-01

    Through the comparison of several regional-scale chemistry transport modeling systems that simulate meteorology and air quality over the European and North American continents, this study aims at (i) apportioning error to the responsible processes using timescale analysis, (ii) helping to detect causes of model error, and (iii) identifying the processes and temporal scales most urgently requiring dedicated investigations. The analysis is conducted within the framework of the third phase of the Air Quality Model Evaluation International Initiative (AQMEII) and tackles model performance gauging through measurement-to-model comparison, error decomposition, and time series analysis of the models biases for several fields (ozone, CO, SO2, NO, NO2, PM10, PM2. 5, wind speed, and temperature). The operational metrics (magnitude of the error, sign of the bias, associativity) provide an overall sense of model strengths and deficiencies, while apportioning the error to its constituent parts (bias, variance, and covariance) can help assess the nature and quality of the error. Each of the error components is analyzed independently and apportioned to specific processes based on the corresponding timescale (long scale, synoptic, diurnal, and intraday) using the error apportionment technique devised in the former phases of AQMEII. The application of the error apportionment method to the AQMEII Phase 3 simulations provides several key insights. In addition to reaffirming the strong impact of model inputs (emission and boundary conditions) and poor representation of the stable boundary layer on model bias, results also highlighted the high interdependencies among meteorological and chemical variables, as well as among their errors. This indicates that the evaluation of air quality model performance for individual pollutants needs to be supported by complementary analysis of meteorological fields and chemical precursors to provide results that are more insightful from a model

  8. Concealing their communication: exploring psychosocial predictors of young drivers' intentions and engagement in concealed texting.

    PubMed

    Gauld, Cassandra S; Lewis, Ioni; White, Katherine M

    2014-01-01

    Making a conscious effort to hide the fact that you are texting while driving (i.e., concealed texting) is a deliberate and risky behaviour involving attention diverted away from the road. As the most frequent users of text messaging services and mobile phones while driving, young people appear at heightened risk of crashing from engaging in this behaviour. This study investigated the phenomenon of concealed texting while driving, and utilised an extended Theory of Planned Behaviour (TPB) including the additional predictors of moral norm, mobile phone involvement, and anticipated regret to predict young drivers' intentions and subsequent behaviour. Participants (n=171) were aged 17-25 years, owned a mobile phone, and had a current driver's licence. Participants completed a questionnaire measuring their intention to conceal texting while driving, and a follow-up questionnaire a week later to report their behavioural engagement. The results of hierarchical multiple regression analyses showed overall support for the predictive utility of the TPB with the standard constructs accounting for 69% of variance in drivers' intentions, and the extended predictors contributing an additional 6% of variance in intentions over and above the standard constructs. Attitude, subjective norm, PBC, moral norm, and mobile phone involvement emerged as significant predictors of intentions; and intention was the only significant predictor of drivers' self-reported behaviour. These constructs can provide insight into key focal points for countermeasures including advertising and other public education strategies aimed at influencing young drivers to reconsider their engagement in this risky behaviour. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. [Concealed and simulated trauma fatalities(II)].

    PubMed

    Klotzbach, H; Püschel, K

    2001-12-01

    A careful investigation of fatal accidents is required due to the relevant financial consequences for the insured as well as for the insurance company. An evaluation of post-mortem cases handled by our institute from 1988 to 1998 showed that 16% of all fatal accidents were not initially classified as such; it was only possible to determine the cause by post-mortem and criminal investigation. The frequency of a relevant alcoholization varied with different types of accidents. Furthermore, of all fatal accidents, 3% were revealed to be deceptive. Those 42 cases in total, presenting themselves as fatal accidents at first glance, were later determined either to be natural deaths (n = 27), homicide (n = 11) or suicide (n = 4). In addition to this, autopsies showed 83 cases of death to be sequelae to accidents. Particularly in cases of a victim plunging out of the window or into water, it can be difficult to make the distinction between natural death--e.g. as a reason for falling--and suicide or homicide. Further difficulties can result from interpretations of the findings in cases of putrefaction, mauling by animals, defects caused by burning or severely deformed corpses. In these cases, the importance of patho-morphological findings from the autopsy must be emphasized. Indirect sequelae of accidents may be pulmonary embolism or pneumonia. The cause of death has to be classified as accidental if the chain of events is of traumatic origin. Mistakes can be avoided if the medical history is taken conscientiously. If no facts are available, the cause of death should be certificated as undetermined. Our evaluation only included autopsy cases from our institute. The concealed fatal accidents which were incorrectly certified as natural deaths or the cases dismissed by the police and the public prosecutor without performing an autopsy were not evaluated.

  10. Brain fingerprinting classification concealed information test detects US Navy military medical information with P300.

    PubMed

    Farwell, Lawrence A; Richardson, Drew C; Richardson, Graham M; Furedy, John J

    2014-01-01

    A classification concealed information test (CIT) used the "brain fingerprinting" method of applying P300 event-related potential (ERP) in detecting information that is (1) acquired in real life and (2) unique to US Navy experts in military medicine. Military medicine experts and non-experts were asked to push buttons in response to three types of text stimuli. Targets contain known information relevant to military medicine, are identified to subjects as relevant, and require pushing one button. Subjects are told to push another button to all other stimuli. Probes contain concealed information relevant to military medicine, and are not identified to subjects. Irrelevants contain equally plausible, but incorrect/irrelevant information. Error rate was 0%. Median and mean statistical confidences for individual determinations were 99.9% with no indeterminates (results lacking sufficiently high statistical confidence to be classified). We compared error rate and statistical confidence for determinations of both information present and information absent produced by classification CIT (Is a probe ERP more similar to a target or to an irrelevant ERP?) vs. comparison CIT (Does a probe produce a larger ERP than an irrelevant?) using P300 plus the late negative component (LNP; together, P300-MERMER). Comparison CIT produced a significantly higher error rate (20%) and lower statistical confidences: mean 67%; information-absent mean was 28.9%, less than chance (50%). We compared analysis using P300 alone with the P300 + LNP. P300 alone produced the same 0% error rate but significantly lower statistical confidences. These findings add to the evidence that the brain fingerprinting methods as described here provide sufficient conditions to produce less than 1% error rate and greater than 95% median statistical confidence in a CIT on information obtained in the course of real life that is characteristic of individuals with specific training, expertise, or organizational

  11. Brain fingerprinting classification concealed information test detects US Navy military medical information with P300

    PubMed Central

    Farwell, Lawrence A.; Richardson, Drew C.; Richardson, Graham M.; Furedy, John J.

    2014-01-01

    A classification concealed information test (CIT) used the “brain fingerprinting” method of applying P300 event-related potential (ERP) in detecting information that is (1) acquired in real life and (2) unique to US Navy experts in military medicine. Military medicine experts and non-experts were asked to push buttons in response to three types of text stimuli. Targets contain known information relevant to military medicine, are identified to subjects as relevant, and require pushing one button. Subjects are told to push another button to all other stimuli. Probes contain concealed information relevant to military medicine, and are not identified to subjects. Irrelevants contain equally plausible, but incorrect/irrelevant information. Error rate was 0%. Median and mean statistical confidences for individual determinations were 99.9% with no indeterminates (results lacking sufficiently high statistical confidence to be classified). We compared error rate and statistical confidence for determinations of both information present and information absent produced by classification CIT (Is a probe ERP more similar to a target or to an irrelevant ERP?) vs. comparison CIT (Does a probe produce a larger ERP than an irrelevant?) using P300 plus the late negative component (LNP; together, P300-MERMER). Comparison CIT produced a significantly higher error rate (20%) and lower statistical confidences: mean 67%; information-absent mean was 28.9%, less than chance (50%). We compared analysis using P300 alone with the P300 + LNP. P300 alone produced the same 0% error rate but significantly lower statistical confidences. These findings add to the evidence that the brain fingerprinting methods as described here provide sufficient conditions to produce less than 1% error rate and greater than 95% median statistical confidence in a CIT on information obtained in the course of real life that is characteristic of individuals with specific training, expertise, or organizational

  12. Is self-concealment associated with acute and chronic pain?

    PubMed

    Uysal, Ahmet; Lu, Qian

    2011-09-01

    Self-concealment is the predisposition to hide negative personal information. The present research examined whether self-concealment was associated with acute and chronic pain. In Study 1, undergraduate students (N = 44) completed an online questionnaire packet and then completed a cold-pressor task in the laboratory. In Study 2, individuals with chronic pain (N = 85) completed an online survey. Study 1: Trait self-concealment was negatively associated with pain tolerance. Study 2: Self-concealment of chronic pain (hiding aspects of one's chronic pain condition from others) was associated with higher levels of self-reported pain and lower psychological well-being, independent of disclosure of feelings regarding pain. Furthermore, this association was mediated by autonomy and competence needs. Self-concealment was found to be associated with higher levels of pain in both healthy and chronic pain samples. Moreover, the findings also suggest that intervention methods using the self-determination theory framework (i.e., autonomy and competence supportive) might be effective for individuals with chronic pain.

  13. Evaluation and error apportionment of an ensemble of atmospheric chemistry transport modeling systems: multivariable temporal and spatial breakdown

    EPA Science Inventory

    Through the comparison of several regional-scale chemistry transport modelling systems that simulate meteorology and air quality over the European and American continents, this study aims at i) apportioning the error to the responsible processes using time-scale analysis, ii) hel...

  14. Errors in Representing Regional Acid Deposition with Spatially Sparse Monitoring: Case Studies of the Eastern US Using Model Predictions

    EPA Science Inventory

    The current study uses case studies of model-estimated regional precipitation and wet ion deposition to estimate errors in corresponding regional values derived from the means of site-specific values within regions of interest located in the eastern US. The mean of model-estimate...

  15. An investigation of error sources and their impact in estimating the time to the most recent ancestor of spatially and temporally distributed HIV sequences.

    PubMed

    Burr, Tom L; Gattiker, James R; Gerrish, Philip J

    2003-05-15

    This is an investigation of significant error sources and their impact in estimating the time to the most recent common ancestor (MRCA) of spatially and temporally distributed human immunodeficiency virus (HIV) sequences. We simulate an HIV epidemic under a range of assumptions with known time to the MRCA (tMRCA). We then apply a range of baseline (known) evolutionary models to generate sequence data. We next estimate or assume one of several misspecified models and use the chosen model to estimate the time to the MRCA. Random effects and the extent of model misspecification determine the magnitude of error sources that could include: neglected heterogeneity in substitution rates across lineages and DNA sites; uncertainty in HIV isolation times; uncertain magnitude and type of population subdivision; uncertain impacts of host/viral transmission dynamics, and unavoidable model estimation errors. Our results suggest that confidence intervals will rarely have the nominal coverage probability for tMRCA. Neglected effects lead to errors that are unaccounted for in most analyses, resulting in optimistically narrow confidence intervals (CI). Using real HIV sequences having approximately known isolation times and locations, we present possible confidence intervals for several sets of assumptions. In general, we cannot be certain how much to broaden a stated confidence interval for tMRCA. However, we describe the impact of candidate error sources on CI width. We also determine which error sources have the most impact on CI width and demonstrate that the standard bootstrap method will underestimate the CI width. Copyright 2003 John Wiley & Sons, Ltd.

  16. Assessing representation errors of IAGOS CO2, CO and CH4 profile observations: the impact of spatial variations in near-field emissions

    NASA Astrophysics Data System (ADS)

    Boschetti, Fabio; Thouret, Valerie; Nedelec, Philippe; Chen, Huilin; Gerbig, Christoph

    2015-04-01

    Airborne platforms have their main strength in the ability of collecting mixing ratio and meteorological data at different heights across a vertical profile, allowing an insight in the internal structure of the atmosphere. However, rental airborne platforms are usually expensive, limiting the number of flights that can be afforded and hence on the amount of data that can be collected. To avoid this disadvantage, the MOZAIC/IAGOS (Measurements of Ozone and water vapor by Airbus In-service airCraft/In-service Aircraft for a Global Observing System) program makes use of commercial airliners, providing data on a regular basis. It is therefore considered an important tool in atmospheric investigations. However, due to the nature of said platforms, MOZAIC/IAGOS's profiles are located near international airports, which are usually significant emission sources, and are in most cases close to major urban settlements, characterized by higher anthropogenic emissions compared to rural areas. When running transport models at finite resolution, these local emissions can heavily affect measurements resulting in biases in model/observation mismatch. Model/observation mismatch can include different aspects in both horizontal and vertical direction, for example spatial and temporal resolution of the modeled fluxes, or poorly represented convective transport or turbulent mixing in the boundary layer. In the framework of the IGAS (IAGOS for GMES Atmospheric Service) project, whose aim is to improve connections between data collected by MOZAIC/IAGOS and Copernicus Atmospheric Service, the present study is focused on the effect of the spatial resolution of emission fluxes, referred to here as representation error. To investigate this, the Lagrangian transport model STILT (Stochastic Time Inverted Lagrangian Transport) was coupled with EDGAR (Emission Database for Global Atmospheric Research) version-4.3 emission inventory at European regional scale. EDGAR's simulated fluxes for CO, CO2

  17. Analysis of Spatial Smoothing Effect of Short-term Fluctuation of Global Solar Radiation based on the Data Including Quantization Error

    NASA Astrophysics Data System (ADS)

    Ue, Yosuke; Hara, Ryoichi; Kita, Hiroyuki; Saito, Yutaka; Takitani, Katsuyuki; Saito, Masami

    A Photovoltaic (PV) system is expected as one of the promising countermeasures for the global warming and the environmental issues. However, generation output from PV system is generally unstable and unpredictable. Therefore, large penetration of PV systems may cause some serious impacts to the power system operation such as a load frequency control, a voltage regulation, etc. Estimation of the influences of PV system installation is becoming important, however, it requires simultaneous multipoint solar radiation measurements. The Japan Meteorological Business Support Center has provided the 1-min meteorological data observed in Japan, however, its solar radiation data includes quantization errors. This paper proposes a regeneration method for the solar radiation data including quantization errors. This paper also analyses the spatial smoothing effect of the global solar radiation fluctuations.

  18. Millimeter-wave imaging for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.

    2003-07-01

    Full body, real-time, millimeter-wave imaging systems have been developed at the Pacific Northwest National Laboratory for the detection of body-worn, concealed weapons and contraband at security checkpoints. These security systems employ methods derived from microwave holography techniques that utilize phase and amplitude information recorded over a two-dimensional aperture to reconstruct a focused image of the target. Millimeter-wave imaging is well suited for the detection of concealed weapons or other contraband carried on personnel, since millimeter waves are non-ionizing, readily penetrate common clothing material, and are reflected from the human body and any concealed items. In this paper, wide-bandwidth, three-dimensional, holographic microwave imaging techniques and a full-body, planar, millimeter-wave imaging system are described.

  19. Millimeter-wave imaging for concealed weapon detection

    SciTech Connect

    McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.

    2003-07-16

    Full-body, real-time, millimeter-wave imaging systems have been developed at the Pacific Northwest National Laboratory for the detection of body-worn, concealed weapons and contraband at security checkpoints. These security systems employ methods derived from microwave holography techniques that utilize phase and amplitude information recorded over a two-dimensional aperture to reconstruct a focused image of the target. Millimeter-wave imaging is well suited for the detection of concealed weapons or other contraband carried on personnel, since millimeter waves are non-ionizing, readily penetrate common clothing material, and are reflected from the human body and any concealed items. In this paper, wide-bandwidth, three-dimensional, holographic microwave imaging techniques and a full-body, planar, millimeter-wave imaging system are described.

  20. Strategic concealment of sexual identity in an estrilid finch

    PubMed Central

    Langmore, N. E.; Bennett, A. T. D.

    1999-01-01

    One explanation for the evolution of sexual monomorphism is the sexual indistinguishability hypothesis, which argues that in group-living species individuals might benefit by concealing their sex to reduce sexual competition. We tested this hypothesis in long-tailed finches Poephila acuticauda. Males and females could not be reliably distinguished morphologically or by analysis of the reflectance spectra (300 to 700 nm) from the plumage and bill. Males seemed unable to distinguish the sex of an unfamiliar individual in the absence of behavioural cues; they were equally likely to court and copulate with unfamiliar males and females but rarely courted familiar males. Here we report the first experimental evidence that sexual monomorphism enables strategic concealment of sex. Males were more likely to reveal their sex when faced with a solitary unfamiliar individual than a group of unfamiliar individuals. When encountering an unfamiliar male that revealed his sex, subordinate males were more likely to conceal their sex than dominant males.

  1. Concealed pregnancy: prevalence, perinatal measures and socio-demographics.

    PubMed

    Thynne, C; Gaffney, G; O'Neill, M; Tonge, M; Sherlock, C

    2012-09-01

    A target group of women who concealed their pregnancy (n = 43) was compared to an aged-matched control group (n = 30) that experienced a crisis pregnancy. Comparisons were also made with a larger dataset (n = 6363) of births in University Hospital Galway (UHG) (normative group). Data was analysed using the Chi-square test and the Kolmogorov-Smirnoff two-sample test. The number of women from the target group that were from a rural background was 28 (65%), compared to 10 (33%) from the control group. The number of women from the target group that feared a negative parental reaction to the pregnancy was 34 (79%), compared to 12 (40%) from the control group. The birth weight in the target group was 4009 lower than the normative birth weight. The average age of women who concealed was 8 years lower than the normative age. The prevalence of concealed pregnancy in UHG was one in every 148 births.

  2. Impact of Primary Spherical Aberration, Spatial Frequency and Stiles Crawford Apodization on Wavefront determined Refractive Error: A Computational Study

    PubMed Central

    Xu, Renfeng; Bradley, Arthur; Thibos, Larry N.

    2013-01-01

    Purpose We tested the hypothesis that pupil apodization is the basis for central pupil bias of spherical refractions in eyes with spherical aberration. Methods We employed Fourier computational optics in which we vary spherical aberration levels, pupil size, and pupil apodization (Stiles Crawford Effect) within the pupil function, from which point spread functions and optical transfer functions were computed. Through-focus analysis determined the refractive correction that optimized retinal image quality. Results For a large pupil (7 mm), as spherical aberration levels increase, refractions that optimize the visual Strehl ratio mirror refractions that maximize high spatial frequency modulation in the image and both focus a near paraxial region of the pupil. These refractions are not affected by Stiles Crawford Effect apodization. Refractions that optimize low spatial frequency modulation come close to minimizing wavefront RMS, and vary with level of spherical aberration and Stiles Crawford Effect. In the presence of significant levels of spherical aberration (e.g. C40 = 0.4 µm, 7mm pupil), low spatial frequency refractions can induce −0.7D myopic shift compared to high SF refraction, and refractions that maximize image contrast of a 3 cycle per degree square-wave grating can cause −0.75D myopic drift relative to refractions that maximize image sharpness. Discussion Because of small depth of focus associated with high spatial frequency stimuli, the large change in dioptric power across the pupil caused by spherical aberration limits the effective aperture contributing to the image of high spatial frequencies. Thus, when imaging high spatial frequencies, spherical aberration effectively induces an annular aperture defining that portion of the pupil contributing to a well-focused image. As spherical focus is manipulated during the refraction procedure, the dimensions of the annular aperture change. Image quality is maximized when the inner radius of the induced

  3. Classification of radiological errors in chest radiographs, using support vector machine on the spatial frequency features of false- negative and false-positive regions

    NASA Astrophysics Data System (ADS)

    Pietrzyk, Mariusz W.; Donovan, Tim; Brennan, Patrick C.; Dix, Alan; Manning, David J.

    2011-03-01

    Aim: To optimize automated classification of radiological errors during lung nodule detection from chest radiographs (CxR) using a support vector machine (SVM) run on the spatial frequency features extracted from the local background of selected regions. Background: The majority of the unreported pulmonary nodules are visually detected but not recognized; shown by the prolonged dwell time values at false-negative regions. Similarly, overestimated nodule locations are capturing substantial amounts of foveal attention. Spatial frequency properties of selected local backgrounds are correlated with human observer responses either in terms of accuracy in indicating abnormality position or in the precision of visual sampling the medical images. Methods: Seven radiologists participated in the eye tracking experiments conducted under conditions of pulmonary nodule detection from a set of 20 postero-anterior CxR. The most dwelled locations have been identified and subjected to spatial frequency (SF) analysis. The image-based features of selected ROI were extracted with un-decimated Wavelet Packet Transform. An analysis of variance was run to select SF features and a SVM schema was implemented to classify False-Negative and False-Positive from all ROI. Results: A relative high overall accuracy was obtained for each individually developed Wavelet-SVM algorithm, with over 90% average correct ratio for errors recognition from all prolonged dwell locations. Conclusion: The preliminary results show that combined eye-tracking and image-based features can be used for automated detection of radiological error with SVM. The work is still in progress and not all analytical procedures have been completed, which might have an effect on the specificity of the algorithm.

  4. Assessing spatial fluctuations, temporal variability, and measurement error in estimated levels of disinfection by-products in tap water: implications for exposure assessment

    PubMed Central

    Symanski, E; Savitz, D; Singer, P

    2004-01-01

    Aims: To assess spatial fluctuations, temporal variability, and errors due to sampling and analysis in levels of disinfection by-products in routine monitoring tap water samples and in water samples collected in households within the same distribution system for an exposure assessment study. Methods: Mixed effects models were applied to quantify seasonal effects and the degree to which trihalomethane (THM) levels vary among households or locations relative to variation over time within seasons for any given location. In a separate analysis, the proportion of total variation due to measurement error arising from sampling and analysis was also quantified. Results: THM levels were higher in the summer relative to other seasons. Differences in the relative magnitude of the intra- and inter-household components of variation were observed between the two sets of THM measurements, with a greater proportion of the variation due to differences within seasons for the routine monitoring data and a greater proportion of the variation due to differences across locations for the exposure assessment study data. Such differences likely arose due to differences in the strategies used to select sites for sampling and in the time periods over which the data were collected. With the exception of bromodichloromethane, measurement errors due to sampling and analysis contributed a small proportion of the total variation in THM levels. Conclusions: The utility of routine monitoring data in assigning exposure in epidemiological studies is limited because such data may not represent the magnitude of spatial variability in levels of disinfection by-products across the distribution system. Measurement error contributes a relatively small proportion to the total variation in THM levels, which suggests that gathering a greater number of samples over time with fewer replicates collected at each sampling location is more efficient and would likely yield improved estimates of household exposure

  5. State-Space Analysis Of Model Error: A Probabilistic Parameter Estimation Framework With Spatial Analysis Of Variance

    DTIC Science & Technology

    2011-09-30

    of near-surface surface winds. This represents an important step toward a model capable of characterizing the comlexity of model errors in those...locations over North America over two months observed every 2 days (32 forecasts), it is a large data set and poses a computational problem for...hierarchical Bayesian model. Hyperparameters are a priori independent. The remaining challenge is the computational burden of the hierarchical

  6. Attenuation and bit error rate for four co-propagating spatially multiplexed optical communication channels of exactly same wavelength in step index multimode fibers

    NASA Astrophysics Data System (ADS)

    Murshid, Syed H.; Chakravarty, Abhijit

    2011-06-01

    Spatial domain multiplexing (SDM) utilizes co-propagation of exactly the same wavelength in optical fibers to increase the bandwidth by integer multiples. Input signals from multiple independent single mode pigtail laser sources are launched at different input angles into a single multimode carrier fiber. The SDM channels follow helical paths and traverse through the carrier fiber without interfering with each other. The optical energy from the different sources is spatially distributed and takes the form of concentric circular donut shaped rings, where each ring corresponds to an independent laser source. At the output end of the fiber these donut shaped independent channels can be separated either with the help of bulk optics or integrated concentric optical detectors. This presents the experimental setup and results for a four channel SDM system. The attenuation and bit error rate for individual channels of such a system is also presented.

  7. A technique for estimating spatial sampling errors in coarse-scale soil moisture estimates derived from point-scale observations

    USDA-ARS?s Scientific Manuscript database

    The validation of satellite surface soil moisture retrievals requires the spatial aggregation of point-scale ground soil moisture measurements up to coarse resolution satellite footprint scales (>10 km). In regions containing a limited number of ground measurements per satellite footprint, a large c...

  8. Detection and identification of concealed weapons using matrix pencil

    NASA Astrophysics Data System (ADS)

    Adve, Raviraj S.; Thayaparan, Thayananthan

    2011-06-01

    The detection and identification of concealed weapons is an extremely hard problem due to the weak signature of the target buried within the much stronger signal from the human body. This paper furthers the automatic detection and identification of concealed weapons by proposing the use of an effective approach to obtain the resonant frequencies in a measurement. The technique, based on Matrix Pencil, a scheme for model based parameter estimation also provides amplitude information, hence providing a level of confidence in the results. Of specific interest is the fact that Matrix Pencil is based on a singular value decomposition, making the scheme robust against noise.

  9. Investigation of the structure and lithology of bedrock concealed by basin fill, using ground-based magnetic-field-profile data acquired in the San Rafael Basin, southeastern Arizona

    USGS Publications Warehouse

    Bultman, Mark W.

    2013-01-01

    Data on the Earth’s total-intensity magnetic field acquired near ground level and at measurement intervals as small as 1 m include information on the spatial distribution of nearsurface magnetic dipoles that in many cases are unique to a specific lithology. Such spatial information is expressed in the texture (physical appearance or characteristics) of the data at scales of hundreds of meters to kilometers. These magnetic textures are characterized by several descriptive statistics, their power spectrum, and their multifractal spectrum. On the basis of a graphical comparison and textural characterization, ground-based magnetic-field profile data can be used to estimate bedrock lithology concealed by as much as 100 m of basin fill in some cases, information that is especially important in assessing and exploring for concealed mineral deposits. I demonstrate that multifractal spectra of ground-based magnetic-field-profile data can be used to differentiate exposed lithologies and that the shape and position of the multifractal spectrum of the ground-based magnetic-field-profile of concealed lithologies can be matched to the upward-continued multifractal spectrum of an exposed lithology to help distinguish the concealed lithology. In addition, ground-based magnetic-field-profile data also detect minute differences in the magnetic susceptibility of rocks over small horizontal and vertical distances and so can be used for precise modeling of bedrock geometry and structure, even when that bedrock is concealed by 100 m or more of nonmagnetic basin fill. Such data contain valuable geologic information on the bedrock concealed by basin fill that may not be so visible in aeromagnetic data, including areas of hydrothermal alteration, faults, and other bedrock structures. Interpretation of these data in the San Rafael Basin, southeastern Arizona, has yielded results for estimating concealed lithologies, concealed structural geology, and a concealed potential mineral

  10. Disrupting saccadic updating: visual interference prior to the first saccade elicits spatial errors in the secondary saccade in a double-step task.

    PubMed

    Buonocore, Antimo; Melcher, David

    2015-06-01

    When we explore the visual environment around us, we produce sequences of very precise eye movements aligning the objects of interest with the most sensitive part of the retina for detailed visual processing. A copy of the impending motor command, the corollary discharge, is sent as soon as the first saccade in a sequence is ready to monitor the next fixation location and correctly plan the subsequent eye movement. Neurophysiological investigations have shown that chemical interference with the corollary discharge generates a distinct pattern of spatial errors on sequential eye movements, with similar results also from clinical and TMS studies. Here, we used saccadic inhibition to interfere with the temporal domain of the first of two subsequent saccades during a standard double-step paradigm. In two experiments, we report that the temporal interference on the primary saccade led to a specific error in the final landing position of the second saccade that was consistent with previous lesion and neurophysiological studies, but without affecting the spatial characteristics of the first eye movement. On the other hand, single-step saccades were differently influence by the flash, with a general undershoot, more pronounced for larger saccadic amplitude. These findings show that a flashed visual transient can disrupt saccadic updating in a double-step task, possibly due to the mismatch between the planned and the executed saccadic eye movement.

  11. Quantification and correction of the error due to limited PIV resolution on the accuracy of non-intrusive spatial pressure measurement using a DNS channel flow database

    NASA Astrophysics Data System (ADS)

    Liu, Xiaofeng; Siddle-Mitchell, Seth

    2016-11-01

    The effect of the subgrid-scale (SGS) stress due to limited PIV resolution on pressure measurement accuracy is quantified using data from a direct numerical simulation database of turbulent channel flow (JHTDB). A series of 2000 consecutive realizations of sample block data with 512x512x49 grid nodal points were selected and spatially filtered with a coarse 17x17x17 and a fine 5x5x5 box averaging, respectively, giving rise to corresponding PIV resolutions of roughly 62.6 and 18.4 times of the viscous length scale. Comparison of the reconstructed pressure at different levels of pressure gradient approximation with the filtered pressure shows that the neglect of the viscous term leads to a small but noticeable change in the reconstructed pressure, especially in regions near the channel walls. As a contrast, the neglect of the SGS stress results in a more significant increase in both the bias and the random errors, indicating the SGS term must be accounted for in PIV pressure measurement. Correction using similarity SGS modeling reduces the random error due to the omission of SGS stress from 114.5% of the filtered pressure r.m.s. fluctuation to 89.1% for the coarse PIV resolution, and from 66.5% to 35.9% for the fine PIV resolution, respectively, confirming the benefit of the error compensation method and the positive influence of increasing PIV resolution on pressure measurement accuracy improvement.

  12. Adolescent disclosure and concealment: longitudinal and concurrent associations with aggression.

    PubMed

    Leavitt, Chelom E; Nelson, David A; Coyne, Sarah M; Hart, Craig H

    2013-01-01

    This longitudinal study assessed the association between prior (preschool) and concurrent physical and relational aggression as they relate to Russian adolescents' disclosure and concealment patterns with their parents. In the initial preschool study, there were 106 boys and 106 girls (mean age = 60.24 months, SD = 7.81). Both peer nominations and teacher ratings of aggression were obtained for these children. Ten years later, the majority of these children (72.2%; n = 153) completed a longitudinal follow-up battery of assessments. Included in these measures was a self-reported measure of aggression as well as an assessment of the extent to which these adolescents disclosed to and concealed information from their parents. Separate models were estimated by gender of child for the 153 children who participated in both Time 1 and Time 2 data collections. Preschool physical aggression proved an important longitudinal predictor of adolescent disclosure and concealment for girls. Concurrently, self-rated relational aggression was also significantly associated with concealment for both boys and girls. © 2013 Wiley Periodicals, Inc.

  13. Do Children Understand That People Selectively Conceal or Express Emotion?

    ERIC Educational Resources Information Center

    Hayashi, Hajimu; Shiomi, Yuki

    2015-01-01

    This study examined whether children understand that people selectively conceal or express emotion depending upon the context. We prepared two contexts for a verbal display task for 70 first-graders, 80 third-graders, 64 fifth-graders, and 71 adults. In both contexts, protagonists had negative feelings because of the behavior of the other…

  14. Do Children Understand That People Selectively Conceal or Express Emotion?

    ERIC Educational Resources Information Center

    Hayashi, Hajimu; Shiomi, Yuki

    2015-01-01

    This study examined whether children understand that people selectively conceal or express emotion depending upon the context. We prepared two contexts for a verbal display task for 70 first-graders, 80 third-graders, 64 fifth-graders, and 71 adults. In both contexts, protagonists had negative feelings because of the behavior of the other…

  15. Detection of concealed and buried chemicals by using multifrequency excitations

    SciTech Connect

    Gao Yaohui; Chen, Meng-Ku; Yang, Chia-En; Chang, Yun-Ching; Yao, Jim; Cheng Jiping; Yin, Stuart; Hui Rongqing; Ruffin, Paul; Brantley, Christina; Edwards, Eugene; Luo, Claire

    2010-08-15

    In this paper, we present a new type of concealed and buried chemical detection system by stimulating and enhancing spectroscopic signatures with multifrequency excitations, which includes a low frequency gradient dc electric field, a high frequency microwave field, and higher frequency infrared (IR) radiations. Each excitation frequency plays a unique role. The microwave, which can penetrate into the underground and/or pass through the dielectric covers with low attenuation, could effectively transform its energy into the concealed and buried chemicals and increases its evaporation rate from the sample source. Subsequently, a gradient dc electric field, generated by a Van De Graaff generator, not only serves as a vapor accelerator for efficiently expediting the transportation process of the vapor release from the concealed and buried chemicals but also acts as a vapor concentrator for increasing the chemical concentrations in the detection area, which enables the trace level chemical detection. Finally, the stimulated and enhanced vapors on the surface are detected by the IR spectroscopic fingerprints. Our theoretical and experimental results demonstrate that more than sixfold increase in detection signal can be achieved by using this proposed technology. The proposed technology can also be used for standoff detection of concealed and buried chemicals by adding the remote IR and/or thermal spectroscopic and imaging detection systems.

  16. Inverse synthetic aperture radar imaging for concealed object detection on a naturally walking person

    NASA Astrophysics Data System (ADS)

    Zhuravlev, Andrey; Ivashov, Sergey; Razevig, Vladimir; Vasiliev, Igor; Bechtel, Timothy

    2014-05-01

    This paper describes the architecture of a microwave radar system intended for imaging concealed objects under clothing as a subject walks through the inspection area. The system uses the principle of inverse aperture which is achieved by a person's movement past a stationary microwave sensor array. In the system, the vertical resolution is achieved by arranging microwave sensors vertically while the horizontal resolution is due to the subject's horizontal motion. The positioning of the objects is achieved by employing a synchronous video sensor that allows coherent radar signal processing. A possible radar signal processing technique based on signal accumulation is described. Numerical experiments are conducted with the described object trajectory model. The influence of positioning errors attributed to the video positioning system is also modeled numerically. An experimental setup is designed and proposed to evaluate the suggested signal processing techniques on real data with an electro-mechanical scanner and single transceiver. It is suggested that the signal acquisition with the system can be accomplished using the stop motion technique, in which a series of changing stationary scenes is sampled and processed. Experimental radar images are demonstrated for stationary objects with concealed items and considered as reference images. Further development of the system is suggested.

  17. An improved geopositioning model of QuickBird high resolution satellite imagery by compensating spatial correlated errors

    NASA Astrophysics Data System (ADS)

    Li, Chuang; Shen, Yunzhong; Li, Bofeng; Qiao, Gang; Liu, Shijie; Wang, Weian; Tong, Xiaohua

    2014-10-01

    A lot of studies have been done for correcting the systematic biases of high resolution satellite images (HRSI), which is a fundamental work in the geometric orientation and the geopositioning of HRSI. All the existing bias-corrected models eliminate the biases in the images by expressing the biases as a function of some deterministic parameters (i.e. shift, drift, or affine transformation models), which is indeed effective for most of the commercial high resolution satellite imagery (i.e. IKONOS, GeoEye-1, WorldView-1/2) except for QuickBird. Studies found that QuickBird is the only one that needs more than a simple shift model to absorb the strong residual systematic errors. To further improve the image geopositioning of QuickBird image, in this paper, we introduce space correlated errors (SCEs) and model them as signals in the bias-corrected rational function model (RFM) and estimate the SCEs at the ground control points (GCPs) together with the bias-corrected parameters using least squares collocation. With these estimated SCEs at GCPs, we then predict the SCEs at the unknown points according to their stochastic correlation with SCEs at the GCPs. Finally, we carry out geopositioning for these unknown points after compensating both the biases and the SCEs. The performance of our improved geopositioning model is demonstrated with a stereo pair of QuickBird cross-track images in the Shanghai urban area. The results show that the SCEs exist in HRSI and the presented geopositioning model exhibits a significant improvement, larger than 20% in both latitude and height directions and about 2.8% in longitude direction, in geopositioning accuracy compared to the common used affine transformation model (ATM), which is not taking SCEs into account. The statistical results also show that our improved geopositioning model is superior to the ATM and the second polynomial model (SPM) in both accuracy and reliability for the geopositioning of HRSI.

  18. Effect of the spatial filtering and alignment error of hot-wire probes in a wall-bounded turbulent flow

    NASA Astrophysics Data System (ADS)

    Segalini, A.; Cimarelli, A.; Rüedi, J.-D.; De Angelis, E.; Talamelli, A.

    2011-10-01

    The effort to describe velocity fluctuation distributions in wall-bounded turbulent flows has raised different questions concerning the accuracy of hot-wire measurement techniques close to the wall and more specifically the effect of spatial averaging resulting from the finite size of the wire. Here, an analytical model which describes the effect of the spatial filtering and misalignment of hot-wire probes on the main statistical moments in turbulent wall-bounded flows is presented. The model, which is based on the two-point velocity correlation function, shows that the filtering is directly related to the transverse Taylor micro-scale. By means of turbulent channel flow DNS data, the capacity of the model to accurately describe the probe response is established. At the same time, the filtering effect is appraised for different wire lengths and for a range of misalignment angles which can be expected from good experimental practice. Effects of the second-order terms in the model equations are also taken into account and discussed. In order to use the model in a practical situation, the Taylor micro-scale distribution at least should be provided. A simple scaling law based on classic turbulence theory is therefore introduced and finally employed to estimate the filtering effect for different wire lengths.

  19. Campaign for Right to Carry Concealed Guns on Campuses Gains Traction

    ERIC Educational Resources Information Center

    Wiseman, Rachel

    2012-01-01

    Five years after the Virginia Tech massacre prompted a student in Texas to start a Facebook page in favor of the right to carry concealed weapons on college campuses, the resulting group, Students for Concealed Carry, has advanced its cause. In more than a dozen states, legislation has been introduced to allow the carrying of concealed firearms on…

  20. Quantum Image Steganography and Steganalysis Based On LSQu-Blocks Image Information Concealing Algorithm

    NASA Astrophysics Data System (ADS)

    A. AL-Salhi, Yahya E.; Lu, Songfeng

    2016-08-01

    Quantum steganography can solve some problems that are considered inefficient in image information concealing. It researches on Quantum image information concealing to have been widely exploited in recent years. Quantum image information concealing can be categorized into quantum image digital blocking, quantum image stereography, anonymity and other branches. Least significant bit (LSB) information concealing plays vital roles in the classical world because many image information concealing algorithms are designed based on it. Firstly, based on the novel enhanced quantum representation (NEQR), image uniform blocks clustering around the concrete the least significant Qu-block (LSQB) information concealing algorithm for quantum image steganography is presented. Secondly, a clustering algorithm is proposed to optimize the concealment of important data. Finally, we used Con-Steg algorithm to conceal the clustered image blocks. Information concealing located on the Fourier domain of an image can achieve the security of image information, thus we further discuss the Fourier domain LSQu-block information concealing algorithm for quantum image based on Quantum Fourier Transforms. In our algorithms, the corresponding unitary Transformations are designed to realize the aim of concealing the secret information to the least significant Qu-block representing color of the quantum cover image. Finally, the procedures of extracting the secret information are illustrated. Quantum image LSQu-block image information concealing algorithm can be applied in many fields according to different needs.

  1. Mental Layouts of Concealed Objects as a Function of Bizarre Imagery and Retention Interval.

    ERIC Educational Resources Information Center

    Iaccino, James; And Others

    To determine whether concealed imagery was an effective mnemonic aid in the recall of paired objects, two studies were conducted with explicitly worded instructions to conceal targets and with variable image formation periods. In each study, 40 subjects were presented with counterbalanced verbal descriptions of Concealed, Pictorial, and Separate…

  2. Campaign for Right to Carry Concealed Guns on Campuses Gains Traction

    ERIC Educational Resources Information Center

    Wiseman, Rachel

    2012-01-01

    Five years after the Virginia Tech massacre prompted a student in Texas to start a Facebook page in favor of the right to carry concealed weapons on college campuses, the resulting group, Students for Concealed Carry, has advanced its cause. In more than a dozen states, legislation has been introduced to allow the carrying of concealed firearms on…

  3. Effects of moderate prenatal ethanol exposure and age on social behavior, spatial response perseveration errors and motor behavior.

    PubMed

    Hamilton, Derek A; Barto, Daniel; Rodriguez, Carlos I; Magcalas, Christy M; Fink, Brandi C; Rice, James P; Bird, Clark W; Davies, Suzy; Savage, Daniel D

    2014-08-01

    Persistent deficits in social behavior are among the major negative consequences associated with exposure to ethanol during prenatal development. Prior work from our laboratory has linked deficits in social behavior following moderate prenatal alcohol exposure (PAE) in the rat to functional alterations in the ventrolateral frontal cortex [21]. In addition to social behaviors, the regions comprising the ventrolateral frontal cortex are critical for diverse processes ranging from orofacial motor movements to flexible alteration of behavior in the face of changing consequences. The broader behavioral implications of altered ventrolateral frontal cortex function following moderate PAE have, however, not been examined. In the present study we evaluated the consequences of moderate PAE on social behavior, tongue protrusion, and flexibility in a variant of the Morris water task that required modification of a well-established spatial response. PAE rats displayed deficits in tongue protrusion, reduced flexibility in the spatial domain, increased wrestling, and decreased investigation, indicating that several behaviors associated with ventrolateral frontal cortex function are impaired following moderate PAE. A linear discriminant analysis revealed that measures of wrestling and tongue protrusion provided the best discrimination of PAE rats from saccharin-exposed control rats. We also evaluated all behaviors in young adult (4-5 months) or older (10-11 months) rats to address the persistence of behavioral deficits in adulthood and possible interactions between early ethanol exposure and advancing age. Behavioral deficits in each domain persisted well into adulthood (10-11 months), however, there was no evidence that aging enhances the effects of moderate PAE within the age ranges that were studied.

  4. Passive cylindrical scan by unphased diffraction-limited antennas for low-cost concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Serenelli, Roberto

    2005-05-01

    This paper analyzes a simple low-cost scan system for concealed weapon detection (CWD) on a cooperative subject. The passive imaging system is based on a cylindrical sensing geometry, realized by mechanical vertical scan of a horizontal circle, filled with many diffraction-limited antennas surrounding the subject, over the whole body height. This system is dimensioned to scan an ideally coaxial cylindrical subject of known radius with a fixed spatial resolution. Several system parameters influence the capability of anomaly detection: horizontal spatial resolution (constrained by diffraction limitations on the sensing circle), vertical spatial resolution and radiometric sensitivity (both related to vertical scan settings). Spatial resolution calculations are carried out in function of the working frequency, and achievable resolutions according to diffraction limitations are discussed. A qualitative and quantitative study is done to determine how high radiometric sensitivity (achievable with well-established commercial components) could overcome the poor spatial resolution related to low working frequencies, in view of dielectric anomaly detection; the optimal dwell time (giving a good radiometric/spatial resolution trade-off) is evaluated. Sub-pixel resolution capabilities are briefly considered, together with a least square matching criterium. Performance of an alternative configuration, consisting of a rotating vertical array, is derived from the circular system. Finally, the data fusion from both configurations is suggested.

  5. Estimating Parallax Error Due to Orbital Motion for HST/WFC3 Spatial Scan Observations of 19 Long-period Classical Cepheids

    NASA Astrophysics Data System (ADS)

    Anderson, Richard I.; Casertano, Stefano; Riess, Adam G.

    2017-01-01

    We employ the Hubble Space Telescope's Wide Field Camera 3 (HST/WFC3) in spatial scanning mode to measure 30 - 40μas parallax of 19 classical Cepheids in the Milky Way with the aim of improving the calibration of the cosmic distance scale (Riess et al. 2014; Casertano et al. 2016). The measured parallaxes are an order of magnitude more precise than parallaxes from the first Gaia data release and thus furthermore provide important cross-checks for Gaia data processing.Here we present our work aimed at estimating the parallax error due to orbital motion caused by undetected companion stars (Anderson et al. 2016). We have secured more than 1600 high-precision radial velocity (RV) measurements of the 19 long-period (Ppuls > 9d) Cepheids in our sample using ground-based telescopes on both hemispheres to investigate the presence of spectroscopic companions. We model the RV variability together with orbital motion using a grid of input orbital periods, Porb. We determine upper limits on the (unsigned) projected parallax error induced by hypothetical companions using the orbital configuration upper limits determined by modeling RV data. We thus show that our HST/WFC3 parallax measurements are subject to an error of less than 2% in parallax (i.e., typically less than ±7μas) for 16 stars in the sample, and < 4% for two Cepheids with fewer RV observations. For YZ Carinae, however, we correct the previously published orbital solution and show that the astrometric model must take into account orbital motion to avoid significant (approx. ±100μas) parallax error.We have further investigated long-timescale (Porb > 10yr) orbital motion using literature data and RV templates based on our new data. We thus discover new evidence for RV signals due to long-term orbital motion for 4 Cepheids and critically assess putative evidence for spectroscopic binarity previously reported based on data of much lesser quality. We caution that astrometric measurements of binaries with Porb on

  6. ID-Check: Online Concealed Information Test Reveals True Identity.

    PubMed

    Verschuere, Bruno; Kleinberg, Bennett

    2016-01-01

    The Internet has already changed people's lives considerably and is likely to drastically change forensic research. We developed a web-based test to reveal concealed autobiographical information. Initial studies identified a number of conditions that affect diagnostic efficiency. By combining these moderators, this study investigated the full potential of the online ID-check. Participants (n = 101) tried to hide their identity and claimed a false identity in a reaction time-based Concealed Information Test. Half of the participants were presented with personal details (e.g., first name, last name, birthday), whereas the others only saw irrelevant details. Results showed that participants' true identity could be detected with high accuracy (AUC = 0.98; overall accuracy: 86-94%). Online memory detection can reliably and validly detect whether someone is hiding their true identity. This suggests that online memory detection might become a valuable tool for forensic applications.

  7. Could plate tectonics on Venus be concealed by volcanic deposits

    NASA Technical Reports Server (NTRS)

    Kaula, W. M.; Muradian, L. M.

    1982-01-01

    The present investigation is supplementary to a study reported by Kaula and Phillips (1981). From an analysis of Pioneer Venus altimetry, Kaula and Phillips had inferred that any heat loss from the planet by plate tectonics must be small compared to that from the earth. However, it has been suggested by others that plate tectonic may exist on Venus, but that the expected 'square root of s' dependence of the topographic drop off is not observed because it is concealed by lava flows. The present investigation has the objective to conduct an examination whether this suggestion of concealment by lava flow is correct. On the basis of the performed analysis, it is concluded that the results obtained by Kaula and Phillips appear to be well justified.

  8. Open-area concealed-weapon detection system

    NASA Astrophysics Data System (ADS)

    Pati, P.; Mather, P.

    2011-06-01

    Concealed Weapon Detection (CWD) has become a significant challenge to present day security needs; individuals carrying weapons into airplanes, schools, and secured establishments are threat to public security. Although controlled screening, of people for concealed weapons, has been employed in many establishments, procedures and equipment are designed to work in restricted environments like airport passport control, military checkpoints, hospitals, school and university entrance. Furthermore, screening systems do not effectively decipher between threat and non-threat metal objects, thus leading to high rate of false alarms which can become a liability to daily operational needs of establishments. Therefore, the design and development of a new CWD system to operate in a large open area environment with large numbers of people reduced incidences of false alarms and increased location accuracy is essential.

  9. Effects of modified penoplasty for concealed penis in children.

    PubMed

    Chen, Chao; Li, Ning; Luo, Yi-Ge; Wang, Hong; Tang, Xian-Ming; Chen, Jia-Bo; Dong, Chun-Qiang; Liu, Qiang; Dong, Kun; Su, Cheng; Yang, Ti-Quan

    2016-10-01

    To evaluate the effect of modified penoplasty in the management of concealed penis. We retrospectively reviewed 96 consecutive patients with concealed penis, which had been surgically corrected between July 2013 and July 2015. All patients underwent modified Shiraki phalloplasty. All patients were scheduled for regular follow-up at 1, 3, and 6 months after the surgery. Data on the patients' age, operative time, postoperative complications, and parents' satisfaction grade were collected and analyzed. The mean follow-up period was 17.4 months (range 7-31 months). The mean operative time was 63.2 ± 8.7 min. The mean perpendicular penile length was 1.89 ± 0.77 cm preoperatively and 4.42 ± 0.87 cm postoperatively, with an improved mean length of 2.5 ± 0.68 cm in the flaccid state postoperatively (p < 0.05). The patients' satisfaction grades after the surgery were improved significantly (p < 0.05). Fifty-two patients had penile lymphedema postoperatively; however, it disappeared spontaneously within 3 months. Additionally, postoperative wound infection occurred in two patients. There were no complications such as flap necrosis, penile shaft contracture, voiding difficulty, and erection difficulties. The modified Shiraki phalloplasty for concealed penis can achieve maximum utilization of prepuce to assure coverage of the exposed penile shaft. It has fewer complications, achieving marked asthetics, and functional improvement. It is a relatively ideal means for treating concealed penis.

  10. Concealed objects detection based on FWT in active millimeter-wave images

    NASA Astrophysics Data System (ADS)

    Du, Kun; Zhang, Lu; Chen, Wei; Wan, Guolong; Fu, Ruoran

    2017-01-01

    Active millimeter-wave (MMW) near-filed human imaging is a means for concealed objects detection. A method of concealed objects detection based on fast wavelet transforms (FWT) in the usage of active MMW images is presented as a result of image characteristics, which includes high resolution, characteristics varying in different parts of the human, imaging influenced among human, concealed objects and other objects, and different textures of concealed objects. Images segmentation utilizing results of edge detection based on FWT is conducted and preliminary segmentation results can be obtained. Some kinds of concealed objects according to comparing gray value of concealed objects to human average gray value can be detected in this paper. The experiments of concealed objects on images of actual acquisition are conducted with a result of accurate rate 80.92% and false alarm rate 11.78%, illustrating the effectiveness of the method proposed in this paper.

  11. Biomedical psychiatry and its concealed metaphors: an anthropological perspective.

    PubMed

    Martínez-Hernáez, Angel

    2013-09-01

    The idea that power relations structure social life is self-evident to most anthropologists. Western medical knowledge or biomedicine, and by extension science or scientific knowledge, however, has until relatively recently been exempt from anthropological scrutiny in political terms. An understanding of biomedicine as a system of knowledge that is not a copy of facts but a representation of them has entailed a break with the traditional separation of folk knowledge and scientific knowledge in anthropology, making it possible to include biomedicine in the repertoire of ethnographic objects. The peculiarity of biomedicine as a cultural system, seen from this perspective, lies in a paradox: its self-characterization as a set of non-ideological discourses and practices is a representation that conceals its ideological and power-saturated nature. Through an analysis of DSM-IV-TR, this article explores some of the representational strategies through which this concealment takes place in biomedical psychiatry: the asocial and universal character of mental illness categories; the neutrality of clinical practice; and the non-moral nature of clinical criteria and judgment. These are concealed metaphors in the true sense, for not only do they speak of something without naming it but they also deny their own existence as metaphors.

  12. [Half-gloving cordectomy: a modified procedure for concealed penis].

    PubMed

    Sun, Wei-Gui; Zheng, Qi-Chuan; Jiang, Kun

    2012-06-01

    To search for a simple surgical procedure for the treatment of concealed penis that may have better effect and less complications. We used a modified surgical method in the treatment of 58 patients with concealed penis aged from 3 to 15 (mean 6.8) years. The operation was simplified and involved the following steps: wholly unveiling the penis glans, half-degloving the foreskins, cutting off all the adhesive fibers up to the penile suspensory ligaments, and liberating the external penis. The operation was successful in all the patients, with the operative time of 15 -45 (mean 33) minutes, hospital stay of 2 - 5 (mean 3.5) days, but no complications except mild foreskin edema in 5 cases. The external penis was prolonged from 0.5 - 2.8 (mean 1.4) cm preoperatively to 3.2 - 8.5 (mean 3.9) cm postoperatively. The patients were followed up for 1 -3 years, all satisfied with the length and appearance of the penis, and their sexual and reproductive functions were normal. The modified surgical procedure for concealed penis is simple and effective, with desirable outcomes, few postoperative complications and no damage to sexual and reproductive functions.

  13. Joint Adaptive Pre-processing Resilience and Post-processing Concealment Schemes for 3D Video Transmission

    NASA Astrophysics Data System (ADS)

    El-Shafai, Walid

    2015-03-01

    3D video transmission over erroneous networks is still a considerable issue due to restricted resources and the presence of severe channel errors. Efficiently compressing 3D video with low transmission rate, while maintaining a high quality of received 3D video, is very challenging. Since it is not plausible to re-transmit all the corrupted macro-blocks (MBs) due to real time applications and limited resources. Thus it is mandatory to retrieve the lost MBs at the decoder side using sufficient post-processing schemes, such as error concealment (EC). In this paper, we propose an adaptive multi-mode EC (AMMEC) algorithm at the decoder based on utilizing pre-processing flexible macro-block ordering error resilience (FMO-ER) technique at the encoder; to efficiently conceal the erroneous MBs of intra and inter coded frames of 3D video. Experimental simulation results show that the proposed FMO-ER/AMMEC schemes can significantly improve the objective and subjective 3D video quality.

  14. Real-time passive terahertz imaging system for standoff concealed weapons imaging

    NASA Astrophysics Data System (ADS)

    Luukanen, Arttu; Grönberg, Leif; Grönholm, Markus; Lappalainen, Petteri; Leivo, Mikko; Rautiainen, Anssi; Tamminen, Aleksi; Ala-Laurinaho, Juha; Dietlein, Charles R.; Grossman, Erich N.

    2010-04-01

    The performance of stand-off imaging systems of concealed weapons in the mm-wave range remains limited by the relatively poor angular resolution using practical aperture sizes. For this reason, increasing the operating frequency of the systems is desired, but in practice is hard to realize due to the lack of affordable, low noise amplifiers well beyond 100 GHz. In this paper we present a passive terahertz imaging system which acquires passive terahertz (~200 GHz - ~1 THz) imagery near video frame rate. The system, one copy of which is built in Finland and the other in the U.S., is based on a 64 pixel linear array of superconducting antenna-coupled microbolometers operated within a commercial cryogen-free closed cycle cryocooler, and utilizes conical scanning Schmidt optics. Quantitative measurements on the imager resolution metrics (thermal, spatial and temporal) will be presented. The results from field tests at the Helsinki-Vantaa airport will be presented.

  15. Deep Raman spectroscopy for the non-invasive standoff detection of concealed chemical threat agents.

    PubMed

    Izake, Emad L; Cletus, Biju; Olds, William; Sundarajoo, Shankaran; Fredericks, Peter M; Jaatinen, Esa

    2012-05-30

    Deep Raman spectroscopy has been utilized for the standoff detection of concealed chemical threat agents from a distance of 15 m under real life background illumination conditions. By using combined time and space resolved measurements, various explosive precursors hidden in opaque plastic containers were identified non-invasively. Our results confirm that combined time and space resolved Raman spectroscopy leads to higher selectivity towards the sub-layer over the surface layer as well as enhanced rejection of fluorescence from the container surface when compared to standoff spatially offset Raman spectroscopy. Raman spectra that have minimal interference from the packaging material and good signal-to-noise ratio were acquired within 5 s of measurement time. A new combined time and space resolved Raman spectrometer has been designed with nanosecond laser excitation and gated detection, making it of lower cost and complexity than picosecond-based laboratory systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Temporal spying and concealing process in fibre-optic data transmission systems through polarization bypass

    PubMed Central

    Bony, P.Y.; Guasoni, M.; Morin, P.; Sugny, D.; Picozzi, A.; Jauslin, H.R.; Pitois, S.; Fatome, J.

    2014-01-01

    Recent research has been focused on the ability to manipulate a light beam in such a way to hide, namely to cloak, an event over a finite time or localization in space. The main idea is to create a hole or a gap in the spatial or time domain so as to allow for an object or data to be kept hidden for a while and then to be restored. By enlarging the field of applications of this concept to telecommunications, researchers have recently reported the possibility to hide transmitted data in an optical fibre. Here we report the first experimental demonstration of perpetual temporal spying and blinding process of optical data in fibre-optic transmission line based on polarization bypass. We successfully characterize the performance of our system by alternatively copying and then concealing 100% of a 10-Gb s−1 transmitted signal. PMID:25135759

  17. Correction of concealed penis with preservation of the prepuce.

    PubMed

    Valioulis, I A; Kallergis, I C; Ioannidou, D C

    2015-10-01

    By definition, congenital concealed penis presents at birth. Children are usually referred to physicians because of parental anxiety caused by their child's penile size. Several surgical procedures have been described to treat this condition, but its correction is still technically challenging. The present study reports a simple surgical approach, which allows preservation of the prepuce. During the last 6 years, 18 children with concealed penis (according to the classification by Maizels et al.) have been treated in the present department (mean age 4.5 years, range 3-12 years). Patients with other conditions that caused buried penis were excluded from the study. The operation was performed through a longitudinal midline ventral incision, which was extended hemi-circumferentially at the penile base. The dysgenetic dartos was identified and its distal part was resected. Dissection of the corpora cavernosa was carried down to the suspensory ligament, which was sectioned. Buck's fascia was fixed to Scarpa's fascia and shaft skin was approximated in the midline. Penoscrotal angle was fashioned by Z-plasty or V-Y plasty. The median follow-up was 24 months (range 8-36). The postoperative edema was mild and resolved within a week. All children had good to excellent outcomes. The median pre-operative to postoperative difference in penile length in the flaccid state was 2.6 cm (range 2.0-3.5). No serious complications or recurrent penile retraction were noted. Recent literature mostly suggests that concealed penis is due to deficient proximal attachments of dysgenetic dartos. Consequences of this include: difficulties in maintaining proper hygiene, balanitis, voiding difficulties with prepuce ballooning and urine spraying, and embarrassment among peers. Surgical treatment for congenital concealed penis is warranted in children aged 3 years or older. The basis of the technique is the perception that in boys with congenital concealed penis, the penile integuments are normal

  18. Estimating errors in cloud amount and cloud optical thickness due to limited spatial sampling using a satellite imager as a proxy for nadir-view sensors

    NASA Astrophysics Data System (ADS)

    Liu, Yinghui

    2015-07-01

    Cloud climatologies from space-based active sensors have been used in climate and other studies without their uncertainties specified. This study quantifies the errors in monthly mean cloud amount and optical thickness due to the limited spatial sampling of space-based active sensors. Nadir-view observations from a satellite imager, the Moderate Resolution Imaging Spectroradiometer (MODIS), serve as a proxy for those active sensors and observations within 10° of the sensor's nadir view serve as truth for data from 2003 to 2013 in the Arctic. June-July monthly mean cloud amount and liquid water and ice cloud optical thickness from MODIS for both observations are calculated and compared. Results show that errors increase with decreasing sample numbers for monthly means in cloud amount and cloud optical thickness. The root-mean-square error of monthly mean cloud amount from nadir-view observations increases with lower latitudes, with 0.7% (1.4%) at 80°N and 4.2% (11.2%) at 60°N using data from 2003 to 2013 (from 2012). For a 100 km resolution Equal-Area Scalable Earth Grid (EASE-Grid) cell of 1000 sample numbers, the absolute differences in these two monthly mean cloud amounts are less than 6.5% (9.0%, 11.5%) with an 80 (90, 95)%chance; such differences decrease to 4.0% (5.0%, 6.5%) with 5000 sample numbers. For a 100 km resolution EASE-Grid of 1000 sample numbers, the absolute differences in these two monthly mean cloud optical thicknesses are less than 2.7 (3.8) with a 90% chance for liquid water cloud (ice cloud); such differences decrease to 1.3 (1.0) for 5000 sample numbers. The uncertainties in monthly mean cloud amount and optical thickness estimated in this study may provide useful information for applying cloud climatologies from active sensors in climate studies and suggest the need for future spaceborne active sensors with a wide swath.

  19. An Exploratory Investigation of Social Stigma and Concealment in Patients with Multiple Sclerosis

    PubMed Central

    Germano, Adriana L.; Stadler, Gertraud

    2016-01-01

    Objective: We conducted a preliminary investigation into dimensions of stigma and their relation to disease concealment in a sample of American adults living with multiple sclerosis (MS). Methods: Fifty-three adults with MS in the United States completed an online survey assessing anticipated, internalized, and isolation stigma, as well as concealment. Results: Responses to all the scales were relatively low, on average, but above scale minimums (P < .001). Ratings of isolation stigma and concealment were highest. Anticipated stigma strongly predicted concealment. Conclusions: Many adults living with MS may be concerned that they will be the target of social stigma because of their illness. These concerns are associated with disease concealment. More research is needed to investigate how MS stigma and concealment may be independent contributors to health in patients with MS. PMID:27134581

  20. The role of need satisfaction in self-concealment and well-being.

    PubMed

    Uysal, Ahmet; Lin, Helen Lee; Knee, C Raymond

    2010-02-01

    The present research tests a model derived from self-determination theory to explain why self-concealment (the tendency to keep distressing personal information secret) is associated with negative well-being outcomes. Two studies tested a model in which self-concealment predicts the thwarting of basic needs for autonomy, competence, and relatedness, which then results in negative psychological outcomes. Study 1 involved a cross-sectional design. Structural equation modeling analyses revealed that the model provided an acceptable fit to the data. Study 2 involved a multilevel design. Participants completed daily measures of self-concealment, need satisfaction, and well-being over 16 days. Results supported the proposed mediation model. Furthermore, the associations between daily self-concealment, daily need satisfaction, and daily well-being were independent of trait self-concealment. Overall, the findings suggest that concealing personal distressing information is detrimental to the satisfaction of basic psychological needs, which in turn predicts negative well-being.

  1. 3-D Imaging of Partly Concealed Targets by Laser Radar

    DTIC Science & Technology

    2005-10-01

    laser in the green wavelength region was used for illumination. 3-D Imaging of Partly Concealed Targets by Laser Radar 11 - 8 RTO-MP-SET-094...acknowledge Marie Carlsson and Ann Charlotte Gustavsson for their assistance in some of the experiments. 7.0 REFERENCES [1] U. Söderman, S. Ahlberg...SPIE Vol. 3707, pp. 432-448, USA, 1999. [14] D. Letalick, H. Larsson, M. Carlsson, and A.-C. Gustavsson , “Laser sensors for urban warfare,” FOI

  2. [Effects of false memories on the Concealed Information Test].

    PubMed

    Zaitsu, Wataru

    2012-10-01

    The effects of false memories on polygraph examinations with the Concealed Information Test (CIT) were investigated by using the Deese-Roediger-McDermott (DRM) paradigm, which allows participants to evoke false memories. Physiological responses to questions consisting of learned, lure, and unlearned items were measured and recorded. The results indicated that responses to lure questions showed critical responses to questions about learned items. These responses included repression of respiration, an increase in electrodermal activity, and a drop in heart rate. These results suggest that critical response patterns are generated in the peripheral nervous system by true and false memories.

  3. Pigeons make errors as a result of interval timing in a visual, but not a visual-spatial, midsession reversal task.

    PubMed

    McMillan, Neil; Roberts, William A

    2012-10-01

    It has been shown previously that pigeons make surprising errors on a visually based midsession reversal task (Cook & Rosen, 2010; Rayburn-Reeves, Molet, & Zentall, 2011). We trained birds with red and green sidekeys, with one color rewarded in the first 40 trials (S1) and the other color rewarded in the latter 40 trials (S2). Importantly, in Phases 1 and 3, red and green were always presented on the same side, whereas in Phase 2 sidekeys were presented on the left and right equally often. In Phases 2 and 3, probe sessions with intertrial intervals (ITIs) longer or shorter than the training intertribal interval (ITI) were interjected among baseline sessions. Results showed that pigeons presented with visual-only cues used interval duration since the beginning of the session to predict when the reversal of reward contingency would occur, but pigeons presented with color and spatial dimensions confounded for predicting reward tended to use a more optimal reward-following strategy of choice based on local reinforcement. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

  4. Concealed by conspicuousness: distractive prey markings and backgrounds

    PubMed Central

    Dimitrova, Marina; Stobbe, Nina; Schaefer, H. Martin; Merilaita, Sami

    2009-01-01

    High-contrast markings, called distractive or dazzle markings, have been suggested to draw and hold the attention of a viewer, thus hindering detection or recognition of revealing prey characteristics, such as the body outline. We tested this hypothesis in a predation experiment with blue tits (Cyanistes caeruleus) and artificial prey. We also tested whether this idea can be extrapolated to the background appearance and whether high-contrast markings in the background would improve prey concealment. We compared search times for a high-contrast range prey (HC-P) and a low-contrast range prey (LC-P) in a high-contrast range background (HC-B) and a low-contrast range background (LC-B). The HC-P was more difficult to detect in both backgrounds, although it did not match the LC-B. Also, both prey types were more difficult to find in the HC-B than in the LC-B, in spite of the mismatch of the LC-P. In addition, the HC-P was more difficult to detect, in both backgrounds, when compared with a generalist prey, not mismatching either background. Thus, we conclude that distractive prey pattern markings and selection of microhabitats with distractive features may provide an effective way to improve camouflage. Importantly, high-contrast markings, both as part of the prey coloration and in the background, can indeed increase prey concealment. PMID:19324754

  5. Concealed Threat Detection at Multiple Frames-per-second

    SciTech Connect

    Chang, J T

    2005-11-08

    In this LDRD project, our research purpose is to investigate the science and technology necessary to enable real-time array imaging as a rapid way to detect hidden threats through obscurants such as smoke, fog, walls, doors, and clothing. The goal of this research is to augment the capabilities of protective forces in concealed threat detection. In the current context, threats include people as well as weapons. In most cases, security personnel must make very fast assessments of a threat based upon limited amount of data. Among other attributes, UWB has been shown and quantified to penetrate and propagate through many materials (wood, some concretes, non-metallic building materials, some soils, etc.) while maintaining high range resolution. We have build collaborations with university partners and government agencies. We have considered the impact of psychometrics on target recognition and identification. Specifically we have formulated images in real-time that will engage the user's vision system in a more active way to enhance image interpretation capabilities. In this project, we are researching the use of real time (field programmable gate arrays) integrated with high resolution (cm scale), ultra wide band (UWB) electromagnetic signals for imaging personnel through smoke and walls. We evaluated the ability of real-time UWB imaging for detecting smaller objects, such as concealed weapons that are carried by the obscured personnel. We also examined the cognitive interpretation process of real time UWB electromagnetic images.

  6. 3D laser imaging for concealed object identification

    NASA Astrophysics Data System (ADS)

    Berechet, Ion; Berginc, Gérard; Berechet, Stefan

    2014-09-01

    This paper deals with new optical non-conventional 3D laser imaging. Optical non-conventional imaging explores the advantages of laser imaging to form a three-dimensional image of the scene. 3D laser imaging can be used for threedimensional medical imaging, topography, surveillance, robotic vision because of ability to detect and recognize objects. In this paper, we present a 3D laser imaging for concealed object identification. The objective of this new 3D laser imaging is to provide the user a complete 3D reconstruction of the concealed object from available 2D data limited in number and with low representativeness. The 2D laser data used in this paper come from simulations that are based on the calculation of the laser interactions with the different interfaces of the scene of interest and from experimental results. We show the global 3D reconstruction procedures capable to separate objects from foliage and reconstruct a threedimensional image of the considered object. In this paper, we present examples of reconstruction and completion of three-dimensional images and we analyse the different parameters of the identification process such as resolution, the scenario of camouflage, noise impact and lacunarity degree.

  7. Target Speaker Detection with Concealed EEG Around the Ear.

    PubMed

    Mirkovic, Bojana; Bleichner, Martin G; De Vos, Maarten; Debener, Stefan

    2016-01-01

    Target speaker identification is essential for speech enhancement algorithms in assistive devices aimed toward helping the hearing impaired. Several recent studies have reported that target speaker identification is possible through electroencephalography (EEG) recordings. If the EEG system could be reduced to acceptable size while retaining the signal quality, hearing aids could benefit from the integration with concealed EEG. To compare the performance of a multichannel around-the-ear EEG system with high-density cap EEG recordings an envelope tracking algorithm was applied in a competitive speaker paradigm. The data from 20 normal hearing listeners were concurrently collected from the traditional state-of-the-art laboratory wired EEG system and a wireless mobile EEG system with two bilaterally-placed around-the-ear electrode arrays (cEEGrids). The results show that the cEEGrid ear-EEG technology captured neural signals that allowed the identification of the attended speaker above chance-level, with 69.3% accuracy, while cap-EEG signals resulted in the accuracy of 84.8%. Further analyses investigated the influence of ear-EEG signal quality and revealed that the envelope tracking procedure was unaffected by variability in channel impedances. We conclude that the quality of concealed ear-EEG recordings as acquired with the cEEGrid array has potential to be used in the brain-computer interface steering of hearing aids.

  8. Multispectral concealed weapon detection in visible, infrared, and terahertz

    NASA Astrophysics Data System (ADS)

    Kowalski, Marcin; Kastek, Mariusz; Polakowski, Henryk; Palka, Norbert; Piszczek, Marek; Szustakowski, Mieczyslaw

    2014-05-01

    Detection of concealed dangerous objects is a very demanding problem of public safety. So far, the problem of detecting objects hidden under clothing was considered only in the case of airports but it is becoming more and more important for public places like metro stations, and government buildings. The development of imaging devices and exploration of new spectral bands is a chance to introduce new equipment for assuring public safety. It has been proved that objects hidden under clothing can be detected and visualized using terahertz (THz) cameras. However, passive THz cameras still offer too low image resolution for objects recognition. On the other hand new infrared cameras offer sufficient parameters to detect objects covered with fabrics in some conditions, as well as high image quality and big pixel resolutions. The purpose of the studies is to investigate the possibilities of using various cameras operating in different spectral ranges for detection of concealed objects. In the article, we present the measurement setup consisting of medium wavelength infrared (MWIR), long wavelength infrared (LWIR), THz and visible cameras and the initial results of measurements with various types of clothing and test objects.

  9. Separating deceptive and orienting components in a Concealed Information Test.

    PubMed

    Ambach, Wolfgang; Stark, Rudolf; Peper, Martin; Vaitl, Dieter

    2008-11-01

    The Concealed Information Test (CIT) requires the examinee to deceptively deny recognition of known stimuli and to truthfully deny recognition of unknown stimuli. Because deception and orienting are typically coupled, it is unclear how exactly these sub-processes affect the physiological responses measured in the CIT. The present study aimed at separating the effects of deception from those of orienting. In a mock-crime study, using a modified CIT, thirty-six of seventy-two subjects answered truthfully ('truth group'), whereas the other thirty-six concealed their knowledge ('lie group'). Answering was delayed for 4 s after item presentation. Electrodermal activity (EDA), respiration (RLL), and phasic heart rate (HR) were recorded. A decomposition of EDA responses revealed two response components; the response in the first interval was expected to indicate orienting, stimulus evaluation, and answer preparation, whereas the response in the second interval was assumed to reflect answer-related processes. Inconclusively, both EDA components differentiated between 'probe' and 'irrelevant' items in both groups. Phasic HR and RLL differed between item classes only in the 'lie' group, thus reflecting answer-related processes, possibly deception, rather than merely orienting responses. The findings further support the notion that psychophysiological measures elicited by a modified CIT may reflect different mental processes involved in orienting and deception.

  10. Passive millimeter-wave imaging for concealed article detection

    NASA Astrophysics Data System (ADS)

    Lovberg, John A.; Galliano, Joseph A., Jr.; Clark, Stuart E.

    1997-02-01

    Passive-millimeter-wave imaging (PMI) provides a powerful sensing tool for law enforcement, allowing an unobtrusive means for detecting concealed weapons, explosives, or contraband on persons or in baggage. Natural thermal emissions at millimeter wavelengths from bodies, guns, explosives, and other articles pass easily through clothing or other concealment materials, where they can be detected and converted into conventional 2-dimensional images. A new implementation of PMI has demonstrated a large-area, near- real-time staring capability for personnel inspection at standoff ranges of greater than 10 meters. In this form, PMI does not require operator cuing based on subjective 'profiles' of suspicious appearance or behaviors, which may otherwise be construed as violations of civil rights. To the contrary, PMI detects and images heat generated by any object with no predisposition as to its nature or function (e.g. race or gender of humans). As a totally passive imaging tool, it generates no radio-frequency or other radiation which might raise public health concerns. Specifics of the new PMI architecture are presented along with a host of imaging data representing the current state- of-the-art.

  11. Terahertz imaging system performance model for concealed-weapon identification

    NASA Astrophysics Data System (ADS)

    Murrill, Steven R.; Jacobs, Eddie L.; Moyer, Steven K.; Halford, Carl E.; Griffin, Steven T.; De Lucia, Frank C.; Petkie, Douglas T.; Franck, Charmaine C.

    2008-03-01

    The U.S. Army Night Vision and Electronic Sensors Directorate (NVESD) and the U.S. Army Research Laboratory have developed a terahertz (THz) -band imaging system performance model for detection and identification of concealed weaponry. The MATLAB-based model accounts for the effects of all critical sensor and display components and for the effects of atmospheric attenuation, concealment material attenuation, and active illumination. The model is based on recent U.S. Army NVESD sensor performance modeling technology that couples system design parameters to observer-sensor field performance by using the acquire methodology for weapon identification performance predictions. This THz model has been developed in support of the Defense Advanced Research Project Agencies' Terahertz Imaging Focal-Plane Technology (TIFT) program and is currently being used to guide the design and development of a 0.650 THz active-passive imaging system. This paper will describe the THz model in detail, provide and discuss initial modeling results for a prototype THz imaging system, and outline plans to calibrate and validate the model through human perception testing.

  12. Terahertz imaging system performance model for concealed weapon identification

    NASA Astrophysics Data System (ADS)

    Murrill, Steven R.; Jacobs, Eddie L.; Moyer, Steven K.; Halford, Carl E.; Griffin, Steven T.; De Lucia, Frank C.; Petkie, Douglas T.; Franck, Charmaine C.

    2005-11-01

    The U.S. Army Night Vision and Electronic Sensors Directorate and the U.S. Army Research Laboratory have developed a terahertz-band imaging system performance model for detection and identification of concealed weaponry. The MATLAB-based model accounts for the effects of all critical sensor and display components, and for the effects of atmospheric attenuation, concealment material attenuation, and active illumination. The model is based on recent U.S. Army NVESD sensor performance models that couple system design parameters to observer-sensor field performance using the acquire methodology for weapon identification performance predictions. This THz model has been developed in support of the Defense Advanced Research Project Agencies' Terahertz Imaging Focal-Plane-Array Technology (TIFT) program and is presently being used to guide the design and development of a 0.650 THz active/passive imaging system. This paper will describe the THz model in detail, provide and discuss initial modeling results for a prototype THz imaging system, and outline plans to validate and calibrate the model through human perception testing.

  13. Optical 3D imaging and visualization of concealed objects

    NASA Astrophysics Data System (ADS)

    Berginc, G.; Bellet, J.-B.; Berechet, I.; Berechet, S.

    2016-09-01

    This paper gives new insights on optical 3D imagery. In this paper we explore the advantages of laser imagery to form a three-dimensional image of the scene. 3D laser imaging can be used for three-dimensional medical imaging and surveillance because of ability to identify tumors or concealed objects. We consider the problem of 3D reconstruction based upon 2D angle-dependent laser images. The objective of this new 3D laser imaging is to provide users a complete 3D reconstruction of objects from available 2D data limited in number. The 2D laser data used in this paper come from simulations that are based on the calculation of the laser interactions with the different meshed objects of the scene of interest or from experimental 2D laser images. We show that combining the Radom transform on 2D laser images with the Maximum Intensity Projection can generate 3D views of the considered scene from which we can extract the 3D concealed object in real time. With different original numerical or experimental examples, we investigate the effects of the input contrasts. We show the robustness and the stability of the method. We have developed a new patented method of 3D laser imaging based on three-dimensional reflective tomographic reconstruction algorithms and an associated visualization method. In this paper we present the global 3D reconstruction and visualization procedures.

  14. Active millimeter wave detection of concealed layers of dielectric material

    NASA Astrophysics Data System (ADS)

    Bowring, N. J.; Baker, J. G.; Rezgui, N. D.; Southgate, M.; Alder, J. F.

    2007-04-01

    Extensive work has been published on millimetre wave active and passive detection and imaging of metallic objects concealed under clothing. We propose and demonstrate a technique for revealing the depth as well as the outline of partially transparent objects, which is especially suited to imaging layer materials such as explosives and drugs. The technique uses a focussed and scanned FMCW source, swept through many GHz to reveal this structure. The principle involved is that a parallel sided dielectric slab produces reflections at both its upper and lower surfaces, acting as a Fabry-Perot interferometer. This produces a pattern of alternating reflected peaks and troughs in frequency space. Fourier or Burg transforming this pattern into z-space generates a peak at the thickness of the irradiated sample. It could be argued that though such a technique may work for single uniform slabs of dielectric material, it will give results of little or no significance when the sample both scatters the incident radiation and gives erratic reflectivities due to its non-uniform thickness and permittivity . We show results for a variety of materials such as explosive simulants, powder and drugs, both alone and concealed under clothing or in a rucksack, which display strongly directional reflectivities at millimeter wavelengths, and whose location is well displayed by a varying thickness parameter as the millimetre beam is scanned across the target. With this system we find that samples can easily be detected at standoff distances of at least 4.6m.

  15. Target Speaker Detection with Concealed EEG Around the Ear

    PubMed Central

    Mirkovic, Bojana; Bleichner, Martin G.; De Vos, Maarten; Debener, Stefan

    2016-01-01

    Target speaker identification is essential for speech enhancement algorithms in assistive devices aimed toward helping the hearing impaired. Several recent studies have reported that target speaker identification is possible through electroencephalography (EEG) recordings. If the EEG system could be reduced to acceptable size while retaining the signal quality, hearing aids could benefit from the integration with concealed EEG. To compare the performance of a multichannel around-the-ear EEG system with high-density cap EEG recordings an envelope tracking algorithm was applied in a competitive speaker paradigm. The data from 20 normal hearing listeners were concurrently collected from the traditional state-of-the-art laboratory wired EEG system and a wireless mobile EEG system with two bilaterally-placed around-the-ear electrode arrays (cEEGrids). The results show that the cEEGrid ear-EEG technology captured neural signals that allowed the identification of the attended speaker above chance-level, with 69.3% accuracy, while cap-EEG signals resulted in the accuracy of 84.8%. Further analyses investigated the influence of ear-EEG signal quality and revealed that the envelope tracking procedure was unaffected by variability in channel impedances. We conclude that the quality of concealed ear-EEG recordings as acquired with the cEEGrid array has potential to be used in the brain-computer interface steering of hearing aids. PMID:27512364

  16. When Concealed Handgun Licensees Break Bad: Criminal Convictions of Concealed Handgun Licensees in Texas, 2001–2009

    PubMed Central

    Nwaiwu, Obioma; McMaughan Moudouni, Darcy K.; Edwards, Rachel; Lin, Szu-hsuan

    2013-01-01

    Objectives. We explored differences in criminal convictions between holders and nonholders of a concealed handgun license (CHL) in Texas. Methods. The Texas Department of Public Safety (DPS) provides annual data on criminal convictions of holders and nonholders of CHLs. We used 2001 to 2009 DPS data to investigate the differences in the distribution of convictions for these 2 groups across 9 types of criminal offenses. We calculated z scores for the differences in the types of crimes for which CHL holders and nonholders were convicted. Results. CHL holders were much less likely than nonlicensees to be convicted of crimes. Most nonholder convictions involved higher-prevalence crimes (burglary, robbery, or simple assault). CHL holders’ convictions were more likely to involve lower-prevalence crimes, such as sexual offenses, gun offenses, or offenses involving a death. Conclusions. Our results imply that expanding the settings in which concealed carry is permitted may increase the risk of specific types of crimes, some quite serious in those settings. These increased risks may be relatively small. Nonetheless, policymakers should consider these risks when contemplating reducing the scope of gun-free zones. PMID:23153139

  17. When concealed handgun licensees break bad: criminal convictions of concealed handgun licensees in Texas, 2001-2009.

    PubMed

    Phillips, Charles D; Nwaiwu, Obioma; McMaughan Moudouni, Darcy K; Edwards, Rachel; Lin, Szu-hsuan

    2013-01-01

    We explored differences in criminal convictions between holders and nonholders of a concealed handgun license (CHL) in Texas. The Texas Department of Public Safety (DPS) provides annual data on criminal convictions of holders and nonholders of CHLs. We used 2001 to 2009 DPS data to investigate the differences in the distribution of convictions for these 2 groups across 9 types of criminal offenses. We calculated z scores for the differences in the types of crimes for which CHL holders and nonholders were convicted. CHL holders were much less likely than nonlicensees to be convicted of crimes. Most nonholder convictions involved higher-prevalence crimes (burglary, robbery, or simple assault). CHL holders' convictions were more likely to involve lower-prevalence crimes, such as sexual offenses, gun offenses, or offenses involving a death. Our results imply that expanding the settings in which concealed carry is permitted may increase the risk of specific types of crimes, some quite serious in those settings. These increased risks may be relatively small. Nonetheless, policymakers should consider these risks when contemplating reducing the scope of gun-free zones.

  18. Management of a Concealable Stigmatized Identity: A Qualitative Study of Concealment, Disclosure, and Role Flexing Among Young, Resilient Sexual and Gender Minority Individuals.

    PubMed

    Bry, Laura Jane; Mustanski, Brian; Garofalo, Robert; Burns, Michelle Nicole

    2017-01-01

    Disclosure of a sexual or gender minority status has been associated with both positive and negative effects on wellbeing. Few studies have explored the disclosure and concealment process in young people. Interviews were conducted with 10 sexual and/or gender minority individuals, aged 18-22 years, of male birth sex. Data were analyzed qualitatively, yielding determinants and effects of disclosure and concealment. Determinants of disclosure included holding positive attitudes about one's identity and an implicit devaluation of acceptance by society. Coming out was shown to have both positive and negative effects on communication and social support and was associated with both increases and decreases in experiences of stigma. Determinants of concealment included lack of comfort with one's identity and various motivations to avoid discrimination. Concealment was also related to hypervigilance and unique strategies of accessing social support. Results are discussed in light of their clinical implications.

  19. 27 CFR 447.62 - False statements or concealment of facts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... concealment of facts. 447.62 Section 447.62 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... IMPLEMENTS OF WAR Penalties, Seizures and Forfeitures § 447.62 False statements or concealment of facts. Any... fact or fails to state a material fact required to be stated therein or necessary to make...

  20. 27 CFR 447.62 - False statements or concealment of facts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... concealment of facts. 447.62 Section 447.62 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... IMPLEMENTS OF WAR Penalties, Seizures and Forfeitures § 447.62 False statements or concealment of facts. Any... fact or fails to state a material fact required to be stated therein or necessary to make...

  1. Pathways Between Concealable Stigmatized Identities and Substance Misuse

    PubMed Central

    Talley, Amelia E.; Littlefield, Andrew K.

    2015-01-01

    Individuals with concealable stigmatized identities often possess no obviously devalued attributes, yet are at greater risk for problematic substance use compared to their privileged counterparts. We present a conceptual model, which proposes that identity-relevant content and characteristics have important implications for cognitive, affective, and behavioral consequences of stigma-related stress. In doing so, we synthesize stigma-related models from the extant literature and attempt to integrate these concepts with previous work detailing potential contributors to substance use behaviors specifically. Finally, we ask readers to consider the various ways in which the content and characteristics of an individual’s stigmatized identity might combine with situational and additional individual difference factors to influence the likelihood of substance misuse. PMID:26379766

  2. Incidental radiographic finding of the concealed art of susuk.

    PubMed

    Devang Divakar, Darshan; Mavinapalla, Seema; Al Kheraif, Abdulaziz Abdullah; Ramakrishnaiah, Ravikumar; Abd Rahim, Muhammad Furqon Bin; Khan, Aftab Ahmed

    2016-07-01

    Susuk, or charm needles, are small, metallic needles inserted under the skin, considered to enhance beauty, health and luck. This hidden secret of inserting susuk is a traditional superstitious ritual, widely practiced among women of Southeast Asia. Here, we present an interesting case of incidental radiographic finding of the concealed art of susuk, which was exposed on a panoramic radiograph taken on a routine basis as a part of diagnostic work up at our centre. An orthopantomogram revealed bilateral metallic foreign bodies in the maxillo-facial region. Anamnestic data affirmed the practice of the body art of susuk. The charm needles were present in the orofacial region without the patient experiencing any pathological signs or symptoms. © The Author(s) 2015.

  3. Worker's refusal to conceal HIV tattoo amounts to misconduct.

    PubMed

    1997-07-25

    [Name removed] was fired in 1994 from his job as a nurse's aide at the Seattle, WA Harborview Medical Center after refusing to cover a tattoo on his left inside forearm that reads HIV POSITIVE. The 9th U.S. Circuit Court of Appeals rejected [name removed]'s arguments that he was terminated because of his HIV status and not the tattoo. He contended that the hospital violated the Americans with Disabilities Act (ADA), the Rehabilitation Act, and his First Amendment right to free speech. The judge agreed with the hospital that [name removed]'s refusal to conceal the tattoo amounted to insubordination. The appeals panel affirmed the granting of summary judgment on [name removed]'s ADA and Rehabilitation Act claims. [Name removed] said he had himself tattooed to help dispel the stigma attached to his infection. The hospital said the tattoo alarmed some patients.

  4. Geophysical investigations of concealed faults near Yucca Mountain, Southwest Nevada

    USGS Publications Warehouse

    Ponce, D.A.

    1993-01-01

    Detailed gravity and ground magnetic data collected along surveyed traverses across Midway Valley, on the eastern flank of Yucca Mountain, Nevada reveal that these methods can be used to delineate concealed faults. These studies are part of an effort to evaluate faulting in the vicinity of the proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. The largest gravity and magnetic anomaly in the vicinity of Midway Valley is associated with the Paintbrush fault on the west flank of Alice Ridge. Geophysical data infer a vertical offset of about 200 m (650 ft). Another prominent gravity and magnetic anomaly is associated with the Bow Ridge fault in the western part of Midway Valley.

  5. Self-envy and the concealment of inner resources.

    PubMed

    Berman, A

    1999-01-01

    Self-envy refers to envy of one's own inner resources. This term is an adjunct to the psychodynamic understanding of developmental self-arrest, defined as deliberate and defensive impairment of one's own abilities and accomplishments and the concealment of inner resources. The article suggests possible explanations for the formation of self-envy, emphasizing the formation of envious object representations and the construction of a part of the personality based on these introjections. The effects of self-envy on patient therapist relations are also described, focusing on two particular manifestations: attachment to the therapist as a defense against self-envy and attacking the therapeutic contract as one of the patient's assets. Excerpts from a case study are included.

  6. Microwave-Spectral Signatures Would Reveal Concealed Objects

    NASA Technical Reports Server (NTRS)

    Arndt, G.; Ngo, P.; Carl, J. R.; Byerly, K.; Stolarcyzk, L.

    2004-01-01

    A proposed technique for locating concealed objects (especially small antipersonnel land mines) involves the acquisition and processing of spectral signatures over broad microwave frequency bands. This technique was conceived to overcome the weaknesses of older narrow- band electromagnetic techniques like ground-probing radar and low-frequency electromagnetic induction. Ground-probing radar is susceptible to false detections and/or interference caused by rocks, roots, air pockets, soil inhomogeneities, ice, liquid water, and miscellaneous buried objects other than those sought. Moreover, if the radar frequency happens to be one for which the permittivity of a sought object matches the permittivity of the surrounding soil or there is an unfavorable complex-amplitude addition of the radar reflection at the receiver, then the object is not detected. Low-frequency electromagnetic induction works well for detecting metallic objects, but the amounts of metal in plastic mines are often too small to be detectable. The potential advantage of the proposed technique arises from the fact that wideband spectral signatures generally contain more relevant information than do narrow-band signals. Consequently, spectral signatures could be used to make better decisions regarding whether concealed objects are present and whether they are the ones sought. In some cases, spectral signatures could provide information on the depths, sizes, shapes, and compositions of objects. An apparatus to implement the proposed technique (see Figure 1) could be assembled from equipment already in common use. Typically, such an apparatus would include a radio-frequency (RF) transmitter/receiver, a broad-band microwave antenna, and a fast personal computer loaded with appropriate software. In operation, the counter would be turned on, the antenna would be aimed at the ground or other mass suspected to contain a mine or other sought object, and the operating frequency would be swept over the band of

  7. Concealing emotions: nurses' experiences with induced abortion care.

    PubMed

    Yang, Cheng-Fang; Che, Hui-Lian; Hsieh, Hsin-Wan; Wu, Shu-Mei

    2016-05-01

    To explore the experiences of nurses involved with induced abortion care in the delivery room in Taiwan. Induced abortion has emotional, ethical and legal facets. In Taiwan, several studies have addressed the ethical issues, abortion methods and women's experiences with abortion care. Although abortion rates have increased, there has been insufficient attention on the views and experiences of nurses working in the delivery room who are involved with induced abortion care. Qualitative, semistructured interviews. This study used a purposive sampling method. In total, 22 nurses involved with induced abortion care were selected. Semistructured interviews with guidelines were conducted, and the content analysis method was used to analyse the data. Our study identified one main theme and five associated subthemes: concealing emotions, which included the inability to refuse, contradictory emotions, mental unease, respect for life and self-protection. This is the first specific qualitative study performed in Taiwan to explore nurses' experiences, and this study also sought to address the concealing of emotions by nurses when they perform induced abortion care, which causes moral distress and creates ethical dilemmas. The findings of this study showed that social-cultural beliefs profoundly influence nurses' values and that the rights of nurses are neglected. The profession should promote small-group and case-study discussions, the clarification of values and reflective thinking among nurses. Continued professional education that provides stress relief will allow nurses to develop self-healing and self-care behaviours, which will enable them to overcome the fear of death while strengthening pregnancy termination counselling, leading to better quality professional care. © 2016 John Wiley & Sons Ltd.

  8. Women with onset of epilepsy prior to marriage: disclose or conceal?

    PubMed

    Santosh, Deetha; Kumar, T Santosh; Sarma, P Sankara; Radhakrishnan, Kurupath

    2007-05-01

    We inquired reasons for concealment/disclosure of the history of epilepsy during marriage negotiations and marriage outcomes of 82 consecutive women attending a tertiary referral center based epilepsy clinic in Kerala, southern India. At the time of marriage, 55% concealed and 45% disclosed the history of epilepsy. Majority of those who concealed admitted that they did so fearing breakup of marriage negotiations, and majority of those who disclosed did so to forestall the consequences after marriage of concealing. Compared to those who disclosed, the prevalence of divorce, separation and disturbed marriages were significantly higher among those who concealed. Honest prospective communication during marriage negotiations about epilepsy is important for preserving subsequent married life.

  9. Selection of food patches by sympatric herbivores in response to concealment and distance from a refuge.

    PubMed

    Crowell, Miranda M; Shipley, Lisa A; Camp, Meghan J; Rachlow, Janet L; Forbey, Jennifer S; Johnson, Timothy R

    2016-05-01

    Small herbivores face risks of predation while foraging and are often forced to trade off food quality for safety. Life history, behaviour, and habitat of predator and prey can influence these trade-offs. We compared how two sympatric rabbits (pygmy rabbit, Brachylagus idahoensis; mountain cottontail, Sylvilagus nuttallii) that differ in size, use of burrows, and habitat specialization in the sagebrush-steppe of western North America respond to amount and orientation of concealment cover and proximity to burrow refuges when selecting food patches. We predicted that both rabbit species would prefer food patches that offered greater concealment and food patches that were closer to burrow refuges. However, because pygmy rabbits are small, obligate burrowers that are restricted to sagebrush habitats, we predicted that they would show stronger preferences for greater cover, orientation of concealment, and patches closer to burrow refuges. We offered two food patches to individuals of each species during three experiments that either varied in the amount of concealment cover, orientation of concealment cover, or distance from a burrow refuge. Both species preferred food patches that offered greater concealment, but pygmy rabbits generally preferred terrestrial and mountain cottontails preferred aerial concealment. Only pygmy rabbits preferred food patches closer to their burrow refuge. Different responses to concealment and proximity to burrow refuges by the two species likely reflect differences in perceived predation risks. Because terrestrial predators are able to dig for prey in burrows, animals like pygmy rabbits that rely on burrow refuges might select food patches based more on terrestrial concealment. In contrast, larger habitat generalists that do not rely on burrow refuges, like mountain cottontails, might trade off terrestrial concealment for visibility to detect approaching terrestrial predators. This study suggests that body size and evolutionary adaptations

  10. Error robustness evaluation of H.264/MPEG-4 AVC

    NASA Astrophysics Data System (ADS)

    Halbach, Till; Olsen, Steffen

    2004-01-01

    The robustness of the recently ratified video compression standard H.264/MPEG-4 AVC against channel errors is evaluated with the focus on rate distortion matters. After a brief introduction of the standard and an explanation of its error-resistant features, it is investigated how the error resilience tools of H.264 can be deployed best for packet-wise transmission as in ATM, H.323, and IP-based services. Further, the performances of two error concealment strategies for use in an H.264-conform decoder are compared to each other.

  11. The social consequences of stigma-related self-concealment after acquired brain injury.

    PubMed

    Hagger, Barbara F; Riley, Gerard A

    2017-09-18

    Social relationships often decline after brain injury. Although much of this is due to psychosocial impairments caused by the injury, the reactions to the injury of others in the person's wider social network, along with the response of the person with the injury to those reactions, also need to be considered. Anxiety about stigmatising reactions from others may lead some to conceal information about their brain injury. This study investigated some of the social consequences of such concealment. Sixty-five participants with acquired brain injury completed the Anticipated Stigma and Concealment Questionnaire, the Social Avoidance and Distress Scale, the UCLA Loneliness Scale, the Rosenberg Self-Esteem Scale, the Social Integration subscale of the Community Integration Questionnaire, and the Enacted Social Support Questionnaire. As hypothesised, concealment was associated with social anxiety, social avoidance, loneliness and lower self-esteem; and anxiety mediated the impact that concealment had on avoidance, loneliness and reduced community activity. However, contrary to expectation, concealment was not associated with reduced use of social support. Concealment may have negative consequences, but inappropriate disclosure can also be harmful. Services should support individuals to make optimal decisions about disclosing information about the brain injury and also help them address psychological barriers to disclosure.

  12. Error analysis of optical correlators

    NASA Technical Reports Server (NTRS)

    Ma, Paul W.; Reid, Max B.; Downie, John D.

    1992-01-01

    With the growing interest in using binary phase only filters (BPOF) in optical correlators that are implemented on magnetooptic spatial light modulators, an understanding of the effect of errors in system alignment and optical components is critical in obtaining optimal system performance. We present simulations of optical correlator performance degradation in the presence of eight errors. We break these eight errors into three groups: 1) alignment errors, 2) errors due to a combination of component imperfections and alignment errors, and 3) errors which result solely from non-ideal components. Under the first group, we simulate errors in the distance from the object to the first principle plane of the transform lens, the distance from the second principle plane of the transform lens to the filter plane, and rotational misalignment of the input mask with the filter mask. Next we consider errors which result from a combination of alignment and component imperfections. These include errors in the transform lens, the phase compensation lens, and the inverse Fourier transform lens. Lastly we have the component errors resulting from the choice of spatial light modulator. These include contrast error and phase errors caused by the non-uniform flatness of the masks. The effects of each individual error are discussed, and the result of combining all eight errors under assumptions of reasonable tolerances and system parameters is also presented. Conclusions are drawn as to which tolerances are most critical for optimal system performance.

  13. Hypoxia in the St. Lawrence Estuary: How a Coding Error Led to the Belief that “Physics Controls Spatial Patterns”

    PubMed Central

    2015-01-01

    Two fundamental sign errors were found in a computer code used for studying the oxygen minimum zone (OMZ) and hypoxia in the Estuary and Gulf of St. Lawrence. These errors invalidate the conclusions drawn from the model, and call into question a proposed mechanism for generating OMZ that challenges classical understanding. The study in question is being cited frequently, leading the discipline in the wrong direction. PMID:26397371

  14. Theoretical analysis on the measurement errors of local 2D DIC: Part I temporal and spatial uncertainty quantification of displacement measurements

    DOE PAGES

    Wang, Yueqi; Lava, Pascal; Reu, Phillip; ...

    2015-12-23

    This study presents a theoretical uncertainty quantification of displacement measurements by subset-based 2D-digital image correlation. A generalized solution to estimate the random error of displacement measurement is presented. The obtained solution suggests that the random error of displacement measurements is determined by the image noise, the summation of the intensity gradient in a subset, the subpixel part of displacement, and the interpolation scheme. The proposed method is validated with virtual digital image correlation tests.

  15. Theoretical analysis on the measurement errors of local 2D DIC: Part I temporal and spatial uncertainty quantification of displacement measurements

    SciTech Connect

    Wang, Yueqi; Lava, Pascal; Reu, Phillip; Debruyne, Dimitri; Van Houtte, Paul

    2015-12-23

    This study presents a theoretical uncertainty quantification of displacement measurements by subset-based 2D-digital image correlation. A generalized solution to estimate the random error of displacement measurement is presented. The obtained solution suggests that the random error of displacement measurements is determined by the image noise, the summation of the intensity gradient in a subset, the subpixel part of displacement, and the interpolation scheme. The proposed method is validated with virtual digital image correlation tests.

  16. A Concealed Barcode Identification System Using Terahertz Time-domain Spectroscopy

    NASA Astrophysics Data System (ADS)

    Guan, Yu; Yamamoto, Manabu; Kitazawa, Toshiyuki; Tripathi, Saroj R.; Takeya, Kei; Kawase, Kodo

    2015-03-01

    We present a concealed terahertz barcode/chipless tag to achieve remote identification through an obstructing material using terahertz radiation. We show scanned terahertz reflection spectral images of barcodes concealed by a thick obstacle. A concealed and double- side printed terahertz barcode structure is proposed, and we demonstrate that our design has better performance in definition than a single-side printed barcode using terahertz time-domain spectroscopy. This technique combines the benefits of a chipless tag to read encoded information covered by an optically opaque material with low cost and a simple fabrication process. Simulations are also described, along with an explanation of the principle of the terahertz barcode identification system.

  17. Event-related brain potentials during the standard autonomic-based concealed information test.

    PubMed

    Matsuda, Izumi; Nittono, Hiroshi; Hirota, Akihisa; Ogawa, Tokihiro; Takasawa, Noriyoshi

    2009-10-01

    The concealed information test (CIT) has been used to detect information that examinees possess by means of their autonomic responses. However, the central activities related to these autonomic responses remain unclear. In this study, we simultaneously recorded 128-ch event-related potentials (ERPs) and various autonomic responses (heart rate, respiratory rate, respiratory amplitude, cutaneous blood flow, and skin conductance response) to a critical item (i.e., the item that participants memorized) and to non-critical items (i.e., items other than the critical item) using the standard protocol of the autonomic-based CIT. A topographic analysis of variance and a temporal-spatial principal component analysis revealed that the critical item elicited a larger negative potential (N2b, 205-298 ms) at central regions and a larger positive potential (positive slow wave, 502-744 ms) at parieto-occipital regions, compared to the non-critical items. Correlation analysis across 21 participants showed a significant correlation between N2b increase and heart rate deceleration in response to critical items compared to non-critical items, but there were no autonomic correlates of the positive slow wave. The results suggest that at least two brain processes are involved in the autonomic-based CIT: The first is an attentional-orienting process that facilitates the processing of critical items, to which heart rate deceleration was linked, and the second is an additional process after the identification of critical items.

  18. Refractive Errors

    MedlinePlus

    ... and lens of your eye helps you focus. Refractive errors are vision problems that happen when the shape ... cornea, or aging of the lens. Four common refractive errors are Myopia, or nearsightedness - clear vision close up ...

  19. ALTIMETER ERRORS,

    DTIC Science & Technology

    CIVIL AVIATION, *ALTIMETERS, FLIGHT INSTRUMENTS, RELIABILITY, ERRORS , PERFORMANCE(ENGINEERING), BAROMETERS, BAROMETRIC PRESSURE, ATMOSPHERIC TEMPERATURE, ALTITUDE, CORRECTIONS, AVIATION SAFETY, USSR.

  20. Living together apart: perceived concealment as a signal of exclusion in marital relationships.

    PubMed

    Finkenauer, Catrin; Kerkhof, Peter; Righetti, Francesca; Branje, Susan

    2009-10-01

    This article examines how perceiving concealment in close relationships influences marital well-being. It suggests that the perception of concealment from a partner signals separateness from one's partner and contributes to feelings of perceived partner exclusion. These feelings of exclusion, in turn, should negatively affect relational quality. These predictions are tested in a prospective study among 199 newlywed couples. Results suggest that perceiving concealment reduced marital adjustment and trust and increased conflict over time. Importantly, change in perceived partner exclusion mediated these effects. This article demonstrates that the perception of concealment (a) has deleterious effects on relational well-being in the long run and (b) is harmful in part because it elicits feelings of exclusion.

  1. Real-time outdoor concealed-object detection with passive millimeter wave imaging.

    PubMed

    Yeom, Seokwon; Lee, Dong-Su; Son, Jung-Young; Jung, Min-Kyoo; Jang, YuShin; Jung, Sang-Won; Lee, Seok-Jae

    2011-01-31

    Millimeter wave imaging is finding rapid adoption in security applications such as the detection of objects concealed under clothing. A passive imaging system can be realized as a stand-off type sensor that can operate in open spaces, both indoors and outdoors. In this paper, we address real-time outdoor concealed-object detection and segmentation with a radiometric imaging system operating in the W-band. The imaging system is equipped with a dielectric lens and a receiver array operating at around 94 GHz. Images are analyzed by multilevel segmentation to identify a concealed object. Each level of segmentation comprises vector quantization, expectation-maximization, and Bayesian decision making to cluster pixels on the basis of a Gaussian mixture model. In addition, we describe a faster process that adopts only vector quantization for the first level segmentation. Experiments confirm that the proposed methods provide fast and reliable detection and segmentation for a moving human subject carrying a concealed gun.

  2. An event study on the concealment of the blending ratio of waste paper.

    PubMed

    Yamaguchi, Keiko

    2009-05-01

    We conducted an event study on the concealment of the blending ratio of waste paper with virgin pulp in Japan. By investigating 10 companies in the paper industry between May 30, 2007 and January 18, 2008, we clearly show that stock prices of the relevant companies were affected by the news on the concealment of the blending ratio of waste paper. In addition, the impact of the second event was found to be greater than that of the first event. Therefore, the concealment of major companies negatively affects the stock prices of non-major companies, which did not conceal information during this period. Thus, bad news is negatively assessed by the market, and this influence has spread in the paper industry in general.

  3. Development of a High-Throughput Microwave Imaging System for Concealed Weapons Detection

    DTIC Science & Technology

    2016-07-15

    Development of a High-Throughput Microwave Imaging System for Concealed Weapons Detection William F. Moulder, James D. Krieger, Janusz J. Majewski...william.moulder@ll.mit.edu Abstract—A video-rate microwave imaging aperture for con- cealed threat detection can serve as a useful tool in securing crowded, high... detection of concealed weapons [3]–[5]. In the latter application, a need exists for a practical system that can image subjects in high foot traffic

  4. Internalizing the closet: concealment heightens the cognitive distinction between public and private selves.

    PubMed

    Sedlovskaya, Alexandra; Purdie-Vaughns, Valerie; Eibach, Richard P; LaFrance, Marianne; Romero-Canyas, Rainer; Camp, Nicholas P

    2013-04-01

    The present studies are the first in which social psychological methods were used to test the popular claim that the experience of concealing a stigmatized social identity leads to a "divided self." For people with concealable stigmas, concealment in public settings makes the public-private dimension of self-expression particularly salient, leading them to organize self-relevant information along this dimension. The result is a strengthened cognitive distinction between public and private aspects of the self, what we have termed public-private schematization. We developed and tested a measure of the cognitive accessibility of the distinction between public and private self-schemas by measuring how quickly participants sorted trait attributes into self-in-public (e.g., self-at-work) and self-in-private (e.g., self-at-home). People with more accessible distinct public and private self-schemas should be faster at categorizing trait attributes into public- and private-self aspects than those with more integrated public and private self-schemas. Relative to people without such identities, people with concealable stigmas (Study 1a, sexual orientation; Study 1b, religiosity at a secular college), show greater public-private schematization. This schematization is linked to concealment (Study 2) and to the experimental activation of concealable versus conspicuous stigmatized identities (Study 3). Implications of distinct public and private self-schemas for psychological well-being are explored in Studies 4 and 5. Two different measures of distress-perceived social stress (Study 4) and depressive symptoms (Study 5)-provided evidence showing that the accessibility of the distinction between public and private self-schemas accounted for the association of concealment on heightened distress. Implications for research on concealment and self-structure are discussed.

  5. Concealing Emotions at Work Is Associated with Allergic Rhinitis in Korea.

    PubMed

    Seok, Hongdeok; Yoon, Jin-Ha; Won, Jong-Uk; Lee, Wanhyung; Lee, June-Hee; Jung, Pil Kyun; Roh, Jaehoon

    2016-01-01

    Concealing emotions at work can cause considerable psychological stress. While there is extensive research on the adverse health effects of concealing emotions and the association between allergic diseases and stress, research has not yet investigated whether concealing emotions at work is associated with allergic rhinitis. Allergic rhinitis is a common disease in many industrialized countries, and its prevalence is increasing. Thus, our aim was to determine the strength of this association using data from three years (2007-2009) of the 4th Korean National Health and Nutrition Examination Survey. Participants (aged 20-64) were 8,345 individuals who were economically active and who had completed the questionnaire items on concealing emotions at work. Odds ratio (OR) and 95% confidence intervals (95% CIs) were calculated for allergic rhinitis using logistic regression models. Among all participants, 3,140 subjects (37.6%) reported concealing their emotions at work: 1,661 men and 1,479 women. The OR (95% CIs) for allergic rhinitis among those who concealed emotions at work versus those who did not was 1.318 (1.148-1.512). Stratified by sex, the OR (95% CIs) was 1.307 (1.078-1.585) among men and 1.346 (1.105-1.639) among women. Thus, individuals who concealed their emotions at work were significantly more likely to have a diagnosis of AR in comparison to those who did not. Because concealing emotions at work has adverse health effects, labor policies that aim to reduce this practice are needed.

  6. Tests of a Dynamic Systems Account of the A-not-B Error: The Influence of Prior Experience on the Spatial Memory Abilities of Two-Year-Olds.

    ERIC Educational Resources Information Center

    Spencer, John P.; Smith, Linda B.; Thelen, Esther

    2001-01-01

    Five experiments tested hypothesis that the A-not-B error results from general processes that make goal-directed actions to remembered locations. Findings showed that 2-year-olds' performance on the A trial was accurate. When the object was hidden at Location B, searches after 10-second delay were biased in the direction of Location A. This bias…

  7. Self-Concealment Mediates the Relationship Between Perfectionism and Attitudes Toward Seeking Psychological Help Among Adolescents.

    PubMed

    Abdollahi, Abbas; Hosseinian, Simin; Beh-Pajooh, Ahmad; Carlbring, Per

    2017-01-01

    One of the biggest barriers in treating adolescents with mental health problems is their refusing to seek psychological help. This study was designed to examine the relationships between two forms of perfectionism, self-concealment and attitudes toward seeking psychological help and to test the mediating role of self-concealment in the relationship between perfectionism and attitudes toward seeking psychological help among Malaysian high school students. The participants were 475 Malaysian high school students from four high schools in Kuala Lumpur, Malaysia. Structural equation modelling results indicated that high school students with high levels of socially prescribed perfectionism, high levels of self-concealment, and low levels of self-oriented perfectionism reported negative attitudes toward seeking psychological help. Bootstrapping analysis showed that self-concealment emerged as a significant, full mediator in the link between socially prescribed perfectionism and attitudes toward seeking psychological help. Moderated mediation analysis also examined whether the results generalized across men and women. The results revealed that male students with socially prescribed perfectionism are more likely to engage in self-concealment, which in turn, leads to negative attitudes toward seeking psychological help more than their female counterparts. The results suggested that students high in socially prescribed perfectionism were more likely to engage in self-concealment and be less inclined to seek psychological help.

  8. Impulse radar imaging system for concealed object detection

    NASA Astrophysics Data System (ADS)

    Podd, F. J. W.; David, M.; Iqbal, G.; Hussain, F.; Morris, D.; Osakue, E.; Yeow, Y.; Zahir, S.; Armitage, D. W.; Peyton, A. J.

    2013-10-01

    Electromagnetic systems for imaging concealed objects at checkpoints typically employ radiation at millimetre and terahertz frequencies. These systems have been shown to be effective and provide a sufficiently high resolution image. However there are difficulties and current electromagnetic systems have limitations particularly in accurately differentiating between threat and innocuous objects based on shape, surface emissivity or reflectivity, which are indicative parameters. In addition, water has a high absorption coefficient at millimetre wavelength and terahertz frequencies, which makes it more difficult for these frequencies to image through thick damp clothing. This paper considers the potential of using ultra wideband (UWB) in the low gigahertz range. The application of this frequency band to security screening appears to be a relatively new field. The business case for implementing the UWB system has been made financially viable by the recent availability of low-cost integrated circuits operating at these frequencies. Although designed for the communication sector, these devices can perform the required UWB radar measurements as well. This paper reports the implementation of a 2 to 5 GHz bandwidth linear array scanner. The paper describes the design and fabrication of transmitter and receiver antenna arrays whose individual elements are a type of antipodal Vivaldi antenna. The antenna's frequency and angular response were simulated in CST Microwave Studio and compared with laboratory measurements. The data pre-processing methods of background subtraction and deconvolution are implemented to improve the image quality. The background subtraction method uses a reference dataset to remove antenna crosstalk and room reflections from the dataset. The deconvolution method uses a Wiener filter to "sharpen" the returned echoes which improves the resolution of the reconstructed image. The filter uses an impulse response reference dataset and a signal

  9. [Abortion in unsafe conditions. Concealment, illegality, corruption and negligence].

    PubMed

    Ortiz Ortega, A

    1993-01-01

    "Abortion practiced under conditions of risk" is a phrase used to refer to illegal abortion. The phrase does not highlight the disappearance of risk when legislation changes. Rather, it calls attention to the fact that legal restrictions significantly increase dangers while failing to discourage women determined to terminate pregnancies. The International Planned Parenthood Federation defines abortion under conditions of risk as the use of nonoptimal technology, lack of counseling and services to orient the woman's decision and provide postabortion counseling, and the limitation of freedom to make the decision. The phrase encompasses concealment, illegality, corruption, and negligence. It is designed to impose a reproductive health perspective in response to an unresolved social conflict. Steps have been developed to improve the situation of women undergoing abortion even without a change in its legal status. Such steps include training and purchase of equipment for treatment of incomplete abortions and development of counseling and family planning services. The central difficulty of abortion induced in conditions of risk derives from the laws imposing the need for secrecy. In Mexico, the abortion decision belongs to the government and the society, while individual absorb the consequences of the practice of abortion. Public decision making about abortion is dominated by the concept that the female has an obligation to carry any pregnancy to term. Women who interfere with male descendency and practice a sexuality distinct from reproduction are made to pay a price in health and emotional balance. Resolution of the problem of abortion will require new concepts in terms of legal status, public health issues, and the rights of women. The problem becomes more pressing as abortion becomes more common in a country anxious to advance in the demographic transition. Only a commitment to the reproductive health of women and the full development of their rights as citizens will

  10. Auto-concealment of supersymmetry in extra dimensions

    SciTech Connect

    Dimopoulos, Savas; Howe, Kiel; March-Russell, John; Scoville, James

    2015-06-05

    In supersymmetric (SUSY) theories with extra dimensions the visible energy in sparticle decays can be significantly reduced and its energy distribution broadened, thus significantly weakening the present collider limits on SUSY. The mechanism applies when the lightest supersymmetric particle (LSP) is a bulk state — e.g. a bulk modulino, axino, or gravitino — the size of the extra dimensions ≳ 10–14 cm, and for a broad variety of visible sparticle spectra. In such cases the lightest ordinary supersymmetric particle (LOSP), necessarily a brane-localised state, decays to the Kaluza-Klein (KK) discretuum of the LSP. This dynamically realises the compression mechanism for hiding SUSY as decays into the more numerous heavier KK LSP states are favored. We find LHC limits on right-handed slepton LOSPs evaporate, while LHC limits on stop LOSPs weaken to ~350 ÷ 410 GeV compared to ~700 GeV for a stop decaying to a massless LSP. Similarly, for the searches we consider, present limits on direct production of degenerate first and second generation squarks drop to ~450 GeV compared to ~800 GeV for a squark decaying to a massless LSP. Auto-concealment typically works for a fundamental gravitational scale of M* ~10 ÷ 100 TeV, a scale sufficiently high that traditional searches for signatures of extra dimensions are mostly avoided. If superpartners are discovered, their prompt, displaced, or stopped decays can also provide new search opportunities for extra dimensions with the potential to reach M* ~109 GeV. As a result, this mechanism applies more generally than just SUSY theories, pertaining to any theory where there is a discrete quantum number shared by both brane and bulk sectors.

  11. Auto-concealment of supersymmetry in extra dimensions

    DOE PAGES

    Dimopoulos, Savas; Howe, Kiel; March-Russell, John; ...

    2015-06-05

    In supersymmetric (SUSY) theories with extra dimensions the visible energy in sparticle decays can be significantly reduced and its energy distribution broadened, thus significantly weakening the present collider limits on SUSY. The mechanism applies when the lightest supersymmetric particle (LSP) is a bulk state — e.g. a bulk modulino, axino, or gravitino — the size of the extra dimensions ≳ 10–14 cm, and for a broad variety of visible sparticle spectra. In such cases the lightest ordinary supersymmetric particle (LOSP), necessarily a brane-localised state, decays to the Kaluza-Klein (KK) discretuum of the LSP. This dynamically realises the compression mechanism formore » hiding SUSY as decays into the more numerous heavier KK LSP states are favored. We find LHC limits on right-handed slepton LOSPs evaporate, while LHC limits on stop LOSPs weaken to ~350 ÷ 410 GeV compared to ~700 GeV for a stop decaying to a massless LSP. Similarly, for the searches we consider, present limits on direct production of degenerate first and second generation squarks drop to ~450 GeV compared to ~800 GeV for a squark decaying to a massless LSP. Auto-concealment typically works for a fundamental gravitational scale of M* ~10 ÷ 100 TeV, a scale sufficiently high that traditional searches for signatures of extra dimensions are mostly avoided. If superpartners are discovered, their prompt, displaced, or stopped decays can also provide new search opportunities for extra dimensions with the potential to reach M* ~109 GeV. As a result, this mechanism applies more generally than just SUSY theories, pertaining to any theory where there is a discrete quantum number shared by both brane and bulk sectors.« less

  12. Robust identification of concealed dangerous substances using THz imaging spectroscopy

    NASA Astrophysics Data System (ADS)

    Nystad, Helle E.; Haakestad, Magnus W.; van Rheenen, Arthur D.

    2015-05-01

    False alarm rates must be kept sufficiently low if a method to detect and identify objects or substances is to be implemented in real life applications. This is also true when trying to detect and identify dangerous substances such as explosives and drugs that are concealed in packaging materials. THz technology may be suited to detect these substances, especially when imaging and spectroscopy are combined. To achieve reasonable throughput, the detection and identification process must be automated and this implies reliance on algorithms to perform this task, rather than human beings. The identification part of the algorithm must compare spectral features of the unknown substance with those in a library of features and determining the distance, in some sense, between these features. If the distance is less than some defined threshold a match is declared. In this paper we consider two types of spectral characteristic that are derived from measured time-domain signals measured in the THz regime: the absorbance and its derivative. Also, we consider two schemes to measure the distance between the unknown and library characteristics: Spectral Angle Mapping (SAM) and Principal Component Analysis (PCA). Finally, the effect of windowing of the measured time-domain signal on the performance of the algorithms is studied, by varying the Blackman-Harris (B-H) window width. Algorithm performance is quantified by studying the receiver-operating characteristics (ROC). For the data considered in this study we conclude that the best performance is obtained when the derivative of the absorbance is used in combination with a narrow B-H window and SAM. SAM is a more straight-forward method and requires no large training data sets and tweaking.

  13. Examination of Biological Effects of Magnetic Field Concealed by Gravity

    NASA Astrophysics Data System (ADS)

    Yamashita, M.; Tomita-Yokotani, K.; Hashimoto, H.; Nakamura, T.

    Response of biological systems against combined environment of zero-gravity and zero-magnetic field should be examined as the baseline to investigate biological effects of magnetic field that might be concealed by gravity. Space offers unique opportunities to conduct such study because long term microgravity is available for the scientific use. However, magnetic environment has been neither well controlled nor documented both in space and ground based experiments. Biological specimen is exposed to the various magnetic field of Earth during the revolutions in orbit. The profile of magnetic field varying in time depends on the orbital parameters and attitude of the space platform. Furthermore, the onboard 1 G control group is subjected to centrifugation spinning where magnetic field varies differently from the microgravity experiment group. It can not be accepted as the 1 G control in terms of magnetic environment. We propose experiment set up to shield exotic magnetic field experienced in orbiting space experiment platform. Thin film of amorphous metal or alloys has shielding capability, and is feasible to implement for space experimentation. In order to simulate zero-gravity and zero-magnetic field on ground, we developed a 3D- clinostat that equips a magnetic shielding layer for specimen. In order to evaluate effects of normal magnetic field of Earth, steady magnetic field is induced at the site of specimen inside the shield layer either in orbit or on 3D-clinostat. To fill the matrix of experimental design, 1 G control under the magnetic shielded condition, and 1 G control that is exposed to the normal field should be taken. Degree of magnetic shielding magnitude required for plant studies and other issues were examined by the preliminary experiments using a 3D-clinostat for the studies of etiolated seedlings.

  14. Satellite Photometric Error Determination

    DTIC Science & Technology

    2015-10-18

    the errors associated with optical photometry used in non-resolved object characterization for the Space Situational Awareness (SSA) community. We...begin with an overview of the standard astronomical techniques used to measure the brightness of spatially unresolved objects (point source photometry ...in deep space. After discussing the standard astronomical techniques, we present the application of astronomical photometry for the purposes of

  15. Medication Errors

    MedlinePlus

    ... address broader product safety issues. FDA Drug Safety Communications for Drug Products Associated with Medication Errors FDA Drug Safety Communication: FDA approves brand name change for antidepressant drug ...

  16. Geometry, structure, and concealed lithology of the San Rafael Basin, southeastern Arizona

    USGS Publications Warehouse

    Bultman, Mark W.

    1999-01-01

    The contiguous United States has been well explored for exposed conventional mineral deposits. Therefore, it is likely that many economically viable and strategically significant conventional undiscovered mineral deposits will be found in bedrock concealed beneath basin sediments. Mineral resource assessments must incorporate an understanding of the geometry, structure, and concealed lithology of basins in order to be accurate. This report presents an analysis of the basin geometry and structure of the San Rafael basin in southeastern Arizona. In addition, a new methodology for inferring concealed lithology is presented and applied in the San Rafael basin. Gravity data is used to model the geometry of the basin using recent models of sediment density vs. depth developed in the region. This modeling indicates that the basin has a maximum depth of approximately 1.05 km plus or minus 0.10 km. In the southern portion, the basin can be modeled as an asymmetric graben faulted on the western margin. The northern portion of the basin is structurally more complex and may have high angle faults on the western, northern, and eastern margin. Near-ground closely spaced Earth’s total intensity magnetic field data is used to locate concealed faults within the basin. This data is also used to infer lithology concealed by shallow basin sediments. Airborne Earth’s total intensity magnetic field data is used to help infer concealed lithology in deep portions of the basin. The product of integrating all data and interpretations is a map which presents the geometry of the basin, faults and contacts concealed by basin sediments, and an estimate of the bedrock lithology concealed by basin sediment. Based on basin geometry and concealed lithology, the San Rafael basin has a high potential for concealed mineral deposits on its western and northern margin. In particular, a newly discovered magnetic anomaly in the northern portion of the basin can be modeled as a granitic intrusion with

  17. Digital spatial data for observed, predicted, and misclassification errors for observations in the training dataset for nitrate and arsenic concentrations in basin-fill aquifers in the Southwest Principal Aquifers study area

    USGS Publications Warehouse

    McKinney, Tim S.; Anning, David W.

    2012-01-01

    This product "Digital spatial data for observed, predicted, and misclassification errors for observations in the training dataset for nitrate and arsenic concentrations in basin-fill aquifers in the Southwest Principal Aquifers study area" is a 1:250,000-scale point spatial dataset developed as part of a regional Southwest Principal Aquifers (SWPA) study (Anning and others, 2012). The study examined the vulnerability of basin-fill aquifers in the southwestern United States to nitrate contamination and arsenic enrichment. Statistical models were developed by using the random forest classifier algorithm to predict concentrations of nitrate and arsenic across a model grid that represents local- and basin-scale measures of source, aquifer susceptibility, and geochemical conditions.

  18. FIA data and species diversity—successes and failures using multivariate analysis techniques, spatial lag and error models and hot-spot analysis

    Treesearch

    Andrew J. Hartsell

    2015-01-01

    This study will investigate how global and local predictors differ with varying spatial scale in relation to species evenness and richness in the gulf coastal plain. Particularly, all-live trees >= one-inch d.b.h. Forest Inventory and Analysis (FIA) data was used as the basis for the study. Watersheds are defined by the USGS 12 digit hydrologic units. The...

  19. Error Analysis

    NASA Astrophysics Data System (ADS)

    Scherer, Philipp O. J.

    Input data as well as the results of elementary operations have to be represented by machine numbers, the subset of real numbers which is used by the arithmetic unit of today's computers. Generally this generates rounding errors. This kind of numerical error can be avoided in principle by using arbitrary precision arithmetics or symbolic algebra programs. But this is unpractical in many cases due to the increase in computing time and memory requirements. Results from more complex operations like square roots or trigonometric functions can have even larger errors since series expansions have to be truncated and iterations accumulate the errors of the individual steps. In addition, the precision of input data from an experiment is limited. In this chapter we study the influence of numerical errors on the uncertainties of the calculated results and the stability of simple algorithms.

  20. Concealment, depression and poor quality of life in patients with congenital facial anomalies.

    PubMed

    Lim, So-Young; Lee, Dongsoo; Oh, Kap Sung; Nam, Bora; Bang, Sa-Ik; Mun, Goo-Hyun; Pyon, Jai-Kyong; Kim, Ji-Hae; Chang Yoon, Se; Song, Hyo-Seok; Jeon, Hong Jin

    2010-12-01

    Studies have shown that patients with congenital facial anomalies are vulnerable to depression. In addition, concealment of facial anomalies in an effort to mask handicaps is common, and these patients also often have difficulties with interpersonal relationships and in social situations. Despite this, no previous study has investigated the association between concealment of facial anomalies and depression, and a patient's quality of life. A group of 65 patients, who had been scheduled for plastic surgery, completed this study. A total of 50 patients who had congenital facial anomalies, some of whom concealed their facial anomalies (N=22), and some whom didn't (N=28), as well as 15 patient controls were interviewed and subsequently administered the Beck Depression Inventory-II (BDI-II), the Structured Clinical Interview for DSM-IV (SCID), the Millon Behavioral Medicine Diagnostic (MBMD) and the WHO Quality of Life (WHOQOL). Among patients with congenital facial anomalies, those who concealed their anomalies exhibited a significantly higher level of depression and anxiety; higher rates of self-accusation, dissatisfaction, hypochondria, weight loss and antisocial personality traits; and a lower quality of life than those who did not conceal their anomalies. To the contrary, no significant differences were found with respect to depression, anxiety and quality of life between the congenital facial anomaly group and controls. Further, the concealment of facial anomalies was a significant predictor for lifetime major depressive disorder (odds ratio (OR)=7.1, 95% confidence interval (CI) 1.4-37.3), after adjusting for age, gender and microtia. Facial concealment is a significant predictor of depression and poor quality of life in patients with congenital facial anomalies. Copyright © 2010 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  1. Using fMRI to decode true thoughts independent of intention to conceal.

    PubMed

    Yang, Zhi; Huang, Zirui; Gonzalez-Castillo, Javier; Dai, Rui; Northoff, Georg; Bandettini, Peter

    2014-10-01

    Multi-variate pattern analysis (MVPA) applied to BOLD-fMRI has proven successful at decoding complicated fMRI signal patterns associated with a variety of cognitive processes. One cognitive process, not yet investigated, is the mental representation of "Yes/No" thoughts that precede the actual overt response to a binary "Yes/No" question. In this study, we focus on examining: (1) whether spatial patterns of the hemodynamic response carry sufficient information to allow reliable decoding of "Yes/No" thoughts; and (2) whether decoding of "Yes/No" thoughts is independent of the intention to respond honestly or dishonestly. To achieve this goal, we conducted two separate experiments. Experiment 1, collected on a 3T scanner, examined the whole brain to identify regions that carry sufficient information to permit significantly above-chance prediction of "Yes/No" thoughts at the group level. In Experiment 2, collected on a 7T scanner, we focused on the regions identified in Experiment 1 to examine the capability of achieving high decoding accuracy at the single subject level. A set of regions--namely right superior temporal gyrus, left supra-marginal gyrus, and left middle frontal gyrus--exhibited high decoding power. Decoding accuracy for these regions increased with trial averaging. When 18 trials were averaged, the median accuracies were 82.5%, 77.5%, and 79.5%, respectively. When trials were separated according to deceptive intentions (set via experimental cues), and classifiers were trained on honest trials, but tested on trials where subjects were asked to deceive, the median accuracies of these regions still reached 66%, 75%, and 78.5%. These results provide evidence that concealed "Yes/No" thoughts are encoded in the BOLD signal, retaining some level of independence from the subject's intentions to answer honestly or dishonestly. These findings also suggest the theoretical possibility for more efficient brain-computer interfaces where subjects only need to think

  2. Physician Beliefs about Physical and Mental Competency of Patients Applying for Concealed Weapon Permits.

    PubMed

    Goldstein, Adam O; Viera, Anthony J; Pierson, John; Barnhouse, Kathy K; Tulsky, James A; Richman, Barak D

    2015-06-01

    Law enforcement officials have asked health care providers to evaluate patient applications for concealed weapon permits. The current study was designed to examine physician beliefs regarding competency to carry a concealed weapon for patients with specific physical and mental conditions. Among 222 North Carolina physicians who participated in this survey (40% response rate), large variation and uncertainty existed for determining competency. Physicians most frequently chose mild dementia, post-traumatic stress disorder, and recent depression as conditions that would render a patient not competent to carry a concealed weapon. Male physicians and those owning a gun were more likely to deem a patient competent. Almost a third of physicians were unsure about competence for most conditions. Physicians asked to assess competency of patients to carry a concealed weapon have quite disparate views on competency and little confidence in their decisions. If physicians are expected to assess patient competence to carry a concealed weapon, more objective criteria and training are needed. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Exploring the characteristics of the attentional blink paradigm when used to discover concealed knowledge.

    PubMed

    Niziurski, Julie; Andre, Jeffrey

    2015-12-01

    Ganis and Patnaik (Appl Psychophysiol Biofeedback 34:189-196, 2009) reported that the attentional blink paradigm using faces could be used to detect the presence of concealed knowledge. The attentional blink is defined as the inability to successfully detect the second of two target items presented within a short inter-stimulus interval. The present study tested the use of the attentional blink paradigm in a concealed knowledge test by investigating the effect that familiar faces may have on the attentional blink. Participants completed 200 trials where they were told to look for the same familiar target (Target 2; actor Brad Pitt) that was intermixed with neutral face stimuli and one other familiar face (Target 1; actor George Clooney). Target 1 was to act as the concealed knowledge as participants familiar with Target 1 would be distracted by his unannounced presence and report not seeing Target 2 thereby showing an attentional blink. Despite all participants being familiar with Target 2, an attentional blink still occurred, but with higher than normal Target 2 accuracy rates. Overall, we found support for using the AB paradigm with the concealed knowledge test; however, a possible countermeasure to the attentional blink is familiarity with Target 2 as eight of 21 participants who recognized Target 1 (the concealed knowledge) were also able to detect Target 2 on 100 % of the trials where Target 1's presence should have created an attentional blink.

  4. Segmentation of Concealed Objects in Passive Millimeter-Wave Images Based on the Gaussian Mixture Model

    NASA Astrophysics Data System (ADS)

    Yu, Wangyang; Chen, Xiangguang; Wu, Lei

    2015-04-01

    Passive millimeter wave (PMMW) imaging has become one of the most effective means to detect the objects concealed under clothing. Due to the limitations of the available hardware and the inherent physical properties of PMMW imaging systems, images often exhibit poor contrast and low signal-to-noise ratios. Thus, it is difficult to achieve ideal results by using a general segmentation algorithm. In this paper, an advanced Gaussian Mixture Model (GMM) algorithm for the segmentation of concealed objects in PMMW images is presented. Our work is concerned with the fact that the GMM is a parametric statistical model, which is often used to characterize the statistical behavior of images. Our approach is three-fold: First, we remove the noise from the image using both a notch reject filter and a total variation filter. Next, we use an adaptive parameter initialization GMM algorithm (APIGMM) for simulating the histogram of images. The APIGMM provides an initial number of Gaussian components and start with more appropriate parameter. Bayesian decision is employed to separate the pixels of concealed objects from other areas. At last, the confidence interval (CI) method, alongside local gradient information, is used to extract the concealed objects. The proposed hybrid segmentation approach detects the concealed objects more accurately, even compared to two other state-of-the-art segmentation methods.

  5. [Sarcolemma tissue of prepubertal concealed penis: pathological characterization and clinical implication].

    PubMed

    Chen, Hai-Tao; Yang, Xing-Hai

    2013-03-01

    To evaluate the histopathological characteristics and clinical implication of sarcolemma tissue in prepubertal concealed penis. After measurement of the penile length, 10 prepubertal children with congenital concealed penis underwent modified Devine's operation (treatment group), and another 10 normal prepubertal children received circumcision (control group). The anatomic features of the penile sarcolemma tissue was observed intraoperatively, and its fibrosis was evaluated by Masson trichrome staining. The penile length of the treatment group was significantly shorter than that of the control group preoperatively ([1.49 +/- 0.17 ] cm vs [4.26 +/- 0.23 ] cm, P < 0.01). The degree of penile concealment was correlated with the distal point of the attachment of its sarcolemma fibrous tissue: the closer the distal attachment point was to the coronary ditch, the more serious was penile concealment. The proportion of the area of collagen fibers in the penile sarcolemma tissue was significantly higher in the treatment group than in the control ([65.6 +/- 6.9]% vs [37.1 +/- 4.7]%, P < 0.01). Sarcolemma fibrosis was obvious in congenital concealed penis, and the key to its management is drastic removal of all the fibrous sarcolemma tissue.

  6. A new surgical technique for concealed penis using an advanced musculocutaneous scrotal flap.

    PubMed

    Han, Dong-Seok; Jang, Hoon; Youn, Chang-Shik; Yuk, Seung-Mo

    2015-06-19

    Until recently, no single, universally accepted surgical method has existed for all types of concealed penis repairs. We describe a new surgical technique for repairing concealed penis by using an advanced musculocutaneous scrotal flap. From January 2010 to June 2014, we evaluated 12 patients (12-40 years old) with concealed penises who were surgically treated with an advanced musculocutaneous scrotal flap technique after degloving through a ventral approach. All the patients were scheduled for regular follow-up at 6, 12, and 24 weeks postoperatively. The satisfaction grade for penile size, morphology, and voiding status were evaluated using a questionnaire preoperatively and at all of the follow-ups. Information regarding complications was obtained during the postoperative hospital stay and at all follow-ups. The patients' satisfaction grades, which included the penile size, morphology, and voiding status, improved postoperatively compared to those preoperatively. All patients had penile lymphedema postoperatively; however, this disappeared within 6 weeks. There were no complications such as skin necrosis and contracture, voiding difficulty, or erectile dysfunction. Our advanced musculocutaneous scrotal flap technique for concealed penis repair is technically easy and safe. In addition, it provides a good cosmetic appearance, functional outcomes and excellent postoperative satisfaction grades. Lastly, it seems applicable in any type of concealed penis, including cases in which the ventral skin defect is difficult to cover.

  7. How many more guns?: Estimating the effect of allowing licensed concealed handguns on a college campus.

    PubMed

    Bouffard, Jeffrey A; Nobles, Matt R; Wells, William; Cavanaugh, Michael R

    2012-01-01

    Among other arguments, advocates for lifting bans on carrying concealed handguns on campus propose that this would increase the prevalence of legitimately carried handguns, which might then deter crimes or be used to intervene in campus shooting incidents like the one that took place at Virginia Tech in 2007. Opponents suggest that increased prevalence of concealed handguns would lead to increases in other negative consequences, such as accidental shootings. Little empirical research has examined the potential outcomes of such a policy change, nor has existing research examined the prerequisite issue of whether lifting these bans would result in substantial increases in the prevalence of concealed handguns among students. Using a sample of undergraduate classrooms selected from five academic buildings at a public university in Texas, this study examines the potential impact of lifting the concealed handgun ban on the likelihood that a given classroom would contain at least one legally carried handgun. Results reveal that the impact of potential policy changes in this area vary based on the building under consideration and the measure of potential handgun prevalence. Limitations of the study and implications for future research on the issue of concealed handgun carrying on college campuses are discussed.

  8. Real-time concealed-object detection and recognition with passive millimeter wave imaging.

    PubMed

    Yeom, Seokwon; Lee, Dong-Su; Jang, Yushin; Lee, Mun-Kyo; Jung, Sang-Won

    2012-04-23

    Millimeter wave (MMW) imaging is finding rapid adoption in security applications such as concealed object detection under clothing. A passive MMW imaging system can operate as a stand-off type sensor that scans people in both indoors and outdoors. However, the imaging system often suffers from the diffraction limit and the low signal level. Therefore, suitable intelligent image processing algorithms would be required for automatic detection and recognition of the concealed objects. This paper proposes real-time outdoor concealed-object detection and recognition with a radiometric imaging system. The concealed object region is extracted by the multi-level segmentation. A novel approach is proposed to measure similarity between two binary images. Principal component analysis (PCA) regularizes the shape in terms of translation and rotation. A geometric-based feature vector is composed of shape descriptors, which can achieve scale and orientation-invariant and distortion-tolerant property. Class is decided by minimum Euclidean distance between normalized feature vectors. Experiments confirm that the proposed methods provide fast and reliable recognition of the concealed object carried by a moving human subject.

  9. Use of Near-Infrared Spectroscopy and Chemometrics for the Nondestructive Identification of Concealed Damage in Raw Almonds (Prunus dulcis).

    PubMed

    Rogel-Castillo, Cristian; Boulton, Roger; Opastpongkarn, Arunwong; Huang, Guangwei; Mitchell, Alyson E

    2016-07-27

    Concealed damage (CD) is defined as a brown discoloration of the kernel interior (nutmeat) that appears only after moderate to high heat treatment (e.g., blanching, drying, roasting, etc.). Raw almonds with CD have no visible defects before heat treatment. Currently, there are no screening methods available for detecting CD in raw almonds. Herein, the feasibility of using near-infrared (NIR) spectroscopy between 1125 and 2153 nm for the detection of CD in almonds is demonstrated. Almond kernels with CD have less NIR absorbance in the region related with oil, protein, and carbohydrates. With the use of partial least squares discriminant analysis (PLS-DA) and selection of specific wavelengths, three classification models were developed. The calibration models have false-positive and false-negative error rates ranging between 12.4 and 16.1% and between 10.6 and 17.2%, respectively. The percent error rates ranged between 8.2 and 9.2%. Second-derivative preprocessing of the selected wavelength resulted in the most robust predictive model.

  10. Convergent validity and effect of instruction modification on the groton maze learning test: a new measure of spatial working memory and error monitoring.

    PubMed

    Pietrzak, Robert H; Maruff, Paul; Snyder, Peter J

    2009-01-01

    This study examined the convergent validity and effect of instruction modification on the Groton Maze Learning Test (GMLT), a computerized hidden maze learning test. Performance on the GMLT was compared to performance on widely used pencil-and-paper and computerized measures of working memory, route selection, and planning/problem solving in a sample of healthy young adults. Performance on GMLT outcome measures correlated with performance on comparator measures of working memory, route selection, and planning (r = 0.31-0.44). Instruction modification (withholding simple instructions) increased the number of rule-break errors on the GMLT (Cohen's d = 0.59). These results provide support for the convergent validity of the GMLT in assessing working memory, route selection, and planning/problem solving, and suggest that a simple instructional modification may yield a novel measure of executive function: feedback monitoring and procedural rule acquisition and application.

  11. [Devine's technique with free skin grafting for concealed penis with prepuce deficit].

    PubMed

    Xu, Xiao-Wen; Xu, Yao-Ting; Shen, Zhi-Jie; Li, Du-Jian; Gu, Wei; Huang, Ru-Qiang

    2011-07-01

    To investigate the clinical effect of Devine's technique with free skin grafting in the treatment of concealed penis with prepuce deficit. This study included 7 children with concealed penis, aged 6 - 15 (mean 8.6) years, 6 of them treated by circumcision previously. All the patients underwent Devine's operation to resect the inelasticity sarcolemma and lengthen the penis. The length of prepuce deficit ranged from 2 to 4 cm. Intermediate split thickness skin grafts of the corresponding length were taken from the femoribus internus to wrap up the tunica albuginea penis, followed by the procedures of saturation, encapsulation and fixation. Surgery time ranged from 70 to 120 minutes, averaging 90.5 minutes. The penis was prolonged about 2 - 4 cm after surgery. A 6-month follow-up revealed desirable penile appearance and normal penile erection. Devine's technique with free skin grafting from the femoribus internus is an ideal treatment for concealed penis with prepuce deficit.

  12. Combining the P300-complex trial-based concealed information test and the reaction time-based autobiographical implicit association test in concealed memory detection.

    PubMed

    Hu, Xiaoqing; Rosenfeld, J Peter

    2012-08-01

    Despite the P300-concealed information test's validity in detecting concealed memory when it is conducted immediately after the mock crime, whether the P300-CIT's detection efficiency is moderated by time delay remains unknown. Here, we conducted a mock crime study in which guilty participants were tested immediately after the mock crime or 1 month later. An innocent group was also tested. Assuming that the autobiographical Implicit Association Test (aIAT) and the P300-CIT rely on nonoverlapping mechanisms for memory detection, participants were tested using both the P300-CIT and the reaction time (RT)-based aIAT. Results suggested that the sensitivity of both tests remains even after the 1-month delay. The indicators from the RT-aIAT and P300-CIT were uncorrelated, thus combining P300-CIT and aIAT data further increased the efficiency of memory detection. Copyright © 2012 Society for Psychophysiological Research.

  13. Faculty perceptions and practices regarding carrying concealed handguns on university campuses.

    PubMed

    Thompson, Amy; Price, James H; Dake, Joseph; Teeple, Karen

    2013-04-01

    The presence of firearms in an environment significantly increases firearm trauma. So far, four states have passed legislation permitting the carrying of concealed handguns on university campuses and several other states are considering such legislation. The purpose of this study to assess the perceptions and practices of college faculty regarding support for carrying concealed handguns on their campuses. A valid and reliable questionnaire was sent to a random sample of 1,125 faculty at 15 randomly selected state universities in five Great Lakes states. A two wave postal mailing in the Spring of 2012 was conducted to help ensure an adequate response rate. A total of 791 (70 %) of the faculty responded. The vast majority felt safe on their campuses (98 %) and were not supportive of people carrying concealed handguns on their campuses (94 %). Seven of the eight potential disadvantages of carrying concealed handguns on campus were supported by the majority of faculty members. Those who were significantly more likely to perceive there to be disadvantages to carrying concealed handguns on campus were: those who did not own a firearm (OR = 4.89), Democrats (OR = 4.52) or Independents (OR = 2.25), Asians (OR = 2.49), and females (OR = 1.51). The vast majority of faculty felt safe on their campuses and perceived that carrying concealed handguns on campuses create more risks than benefits to the campus environment. Aggressive efforts are needed to help maintain the uniquely safe environment of college campuses.

  14. Smoothing error pitfalls

    NASA Astrophysics Data System (ADS)

    von Clarmann, T.

    2014-04-01

    The difference due to the content of a priori information between a constrained retrieval and the true atmospheric state is usually represented by the so-called smoothing error. In this paper it is shown that the concept of the smoothing error is questionable because it is not compliant with Gaussian error propagation. The reason for this is that the smoothing error does not represent the expected deviation of the retrieval from the true state but the expected deviation of the retrieval from the atmospheric state sampled on an arbitrary grid, which is itself a smoothed representation of the true state. The idea of a sufficiently fine sampling of this reference atmospheric state is untenable because atmospheric variability occurs on all scales, implying that there is no limit beyond which the sampling is fine enough. Even the idealization of infinitesimally fine sampling of the reference state does not help because the smoothing error is applied to quantities which are only defined in a statistical sense, which implies that a finite volume of sufficient spatial extent is needed to meaningfully talk about temperature or concentration. Smoothing differences, however, which play a role when measurements are compared, are still a useful quantity if the involved a priori covariance matrix has been evaluated on the comparison grid rather than resulting from interpolation. This is, because the undefined component of the smoothing error, which is the effect of smoothing implied by the finite grid on which the measurements are compared, cancels out when the difference is calculated.

  15. Detection of concealed substances in sealed opaque plastic and coloured glass containers using SORS

    NASA Astrophysics Data System (ADS)

    Bloomfield, Matthew; Loeffen, Paul W.; Matousek, Pavel

    2010-10-01

    The reliable detection of concealed substances in sealed opaque plastic and coloured glass containers, with low falsealarm rate, is a problem in numerous areas of security. For example, in aviation security, there is no reliable methodology for alarm resolution of substances with high chemical specificity unless the substances are in optically transparent containers. We present a recently developed method called Spatially Offset Raman Spectroscopy (SORS) which enables the discrimination of the Raman spectrum of the content substance from the Raman spectrum of the container material with no prior knowledge of either, thereby allowing unambiguous identification of the container contents. The method is effective with coloured plastic containers that are several millimetres thick and which are not see-through to the eye and also for coloured glass bottles. Such cases do not typically yield to conventional backscatter Raman spectroscopy (or have poor false-alarm rates) since the content signal is often overwhelmed by the signal from the container, which may in addition have a strong interfering fluorescence background. SORS measurement can be performed in a few seconds by shining a laser light onto the container and then measuring the Raman signal at the excitation point but also at one or more offset positions. Each measurement has different relative orthogonal contributions from the container and contents Raman spectra, so that, with no prior knowledge, the pure spectra of both the container and contents can be extracted - either by scaled subtraction or via multivariate statistical methods. The content spectrum can then be compared to a reference library of pure materials to give a threat evaluation with a confidence level not compromised by interfering signals originating from the container wall. In this paper, we describe the methods and their optimization, and characterize their performance in practical screening applications. The study shows that there is

  16. Time delay signature concealment of optical feedback induced chaos in an external cavity semiconductor laser.

    PubMed

    Wu, Jia-Gui; Xia, Guang-Qiong; Tang, Xi; Lin, Xiao-Dong; Deng, Tao; Fan, Li; Wu, Zheng-Mao

    2010-03-29

    The time delay (TD) signature concealment of optical feedback induced chaos in an external cavity semiconductor laser is experimentally demonstrated. Both the evolution curve and the distribution map of TD signature are obtained in the parameter space of external feedback strength and injection current. The optimum parameter scope of the TD signature concealment is also specified. Furthermore, the approximately periodic evolution relation between TD signature and external cavity length is observed and indicates that the intrinsic relaxation oscillation of semiconductor laser may play an important role during the process of TD signature suppression.

  17. The association between concealing emotions at work and medical utilization in Korea

    PubMed Central

    2014-01-01

    Objectives We aimed to investigate the association between concealing emotions at work and medical utilization. Methods Data from the 2007–2009 4th Korea National Health and Nutrition Examination Survey (KNHANES IV) was used, 7,094 participants (3,837 males, 3,257 females) aged between 20 and 54 who were economically active and completed all necessary questionnaire items were included. Odds ratios (ORs) and 95% confidence intervals (95% CI) for differences in hospitalization, outpatient visits, and pharmaceutical drug use between those who concealed their emotions and those who did not were investigated using logistic regression models with and without gender stratification. Results Among those who concealed their emotions (n = 2,763), 47.4% were females, and 50.1% had chronic disease. In addition, 9.7% of the concealing emotions group had been hospitalized within the last year, 24.8% had been outpatients in the last two weeks, and 28.3% had used pharmaceutical drugs in the last two weeks. All ORs represent the odds of belonging to the concealing emotions group over the non-concealing emotions group. After adjustment for individual, occupational, socioeconomic and disease factors, the adjusted ORs (95% CI) in hospitalization are 1.29 (1.08 ~ 1.53) in the total population, 1.25 (0.98 ~ 1.60) in males and 1.30 (1.02 ~ 1.66) in females, in outpatient visits are 1.15 (1.02 ~ 1.29) in the total population, 1.05 (0.88 ~ 1.24) in males and 1.25 (1.06 ~ 1.47) in females and in pharmaceutical drug use are 1.12 (1.01 ~ 1.25) in the total population, 1.08 (0.92 ~ 1.27) in males and 1.14 (0.98 ~ 1.33) in females. Conclusions Those who concealed their emotions at work were more likely to use medical services. Moreover, the health effects of concealing emotions at work might be more detrimental in women than in men. PMID:25852941

  18. Identifying the location of a concealed object through unintentional eye movements.

    PubMed

    Neuman, Yair; Assaf, Dan; Israeli, Navot

    2015-01-01

    In some investigative and interrogative contexts, the investigator is seeking to identify the location of an object (e.g., implanted bomb) which is known to a given subject (e.g., a terrorist). In this paper, we present a non-intrusive methodology for uncovering the loci of a concealed object by analyzing the subject's eye movements. Using a combination of eye tracking, psychological manipulation and a search algorithm, we have performed two experiments. In the first experiment, we have gained 58% hit rate in identifying the location of the concealed object and in the second experiment 56% hit rate. The pros and cons of the methodology for forensic investigation are discussed.

  19. Reduction of Surface Errors over a Wide Range of Spatial Frequencies Using a Combination of Electrolytic In-Process Dressing Grinding and Magnetorheological Finishing

    NASA Astrophysics Data System (ADS)

    Kunimura, Shinsuke; Ohmori, Hitoshi

    We present a rapid process for producing flat and smooth surfaces. In this technical note, a fabrication result of a carbon mirror is shown. Electrolytic in-process dressing (ELID) grinding with a metal bonded abrasive wheel, then a metal-resin bonded abrasive wheel, followed by a conductive rubber bonded abrasive wheel, and finally magnetorheological finishing (MRF) were performed as the first, second, third, and final steps, respectively in this process. Flatness over the whole surface was improved by performing the first and second steps. After the third step, peak to valley (PV) and root mean square (rms) values in an area of 0.72 x 0.54 mm2 on the surface were improved. These values were further improved after the final step, and a PV value of 10 nm and an rms value of 1 nm were obtained. Form errors and small surface irregularities such as surface waviness and micro roughness were efficiently reduced by performing ELID grinding using the above three kinds of abrasive wheels because of the high removal rate of ELID grinding, and residual small irregularities were reduced by short time MRF. This process makes it possible to produce flat and smooth surfaces in several hours.

  20. Disclosure and concealment of sexual orientation and the mental health of non-gay-identified, behaviorally bisexual men.

    PubMed

    Schrimshaw, Eric W; Siegel, Karolynn; Downing, Martin J; Parsons, Jeffrey T

    2013-02-01

    Although bisexual men report lower levels of mental health relative to gay men, few studies have examined the factors that contribute to bisexual men's mental health. Bisexual men are less likely to disclose, and more likely to conceal (i.e., a desire to hide), their sexual orientation than gay men. Theory suggests that this may adversely impact their mental health. This report examined the factors associated with disclosure and with concealment of sexual orientation, the association of disclosure and concealment with mental health, and the potential mediators (i.e., internalized homophobia, social support) of this association with mental health. An ethnically diverse sample of 203 non-gay-identified, behaviorally bisexual men who do not disclose their same-sex behavior to their female partners were recruited in New York City to complete a single set of self-report measures. Concealment was associated with higher income, a heterosexual identification, living with a wife or girlfriend, more frequent sex with women, and less frequent sex with men. Greater concealment, but not disclosure to friends and family, was significantly associated with lower levels of mental health. Multiple mediation analyses revealed that both internalized homophobia and general emotional support significantly mediated the association between concealment and mental health. The findings demonstrate that concealment and disclosure are independent constructs among bisexual men. Further, they suggest that interventions addressing concerns about concealment, emotional support, and internalized homophobia may be more beneficial for increasing the mental health of bisexual men than those focused on promoting disclosure.

  1. Concealing the taste of the Guinness World's most bitter substance by using a synthetic nanocontainer.

    PubMed

    Yang, Xue; Li, Shengke; Zhang, Qing-Wen; Zheng, Ying; Bardelang, David; Wang, Lian-Hui; Wang, Ruibing

    2017-08-03

    Upon supramolecular encapsulation by using a synthetic nanocontainer (cucurbit[7]uril), the taste of the Guinness World's most bitter substance, denatonium benzoate, was dramatically concealed during a two-bottle preference drinking test in a mammalian model, demonstrating the significant potential of cucurbit[7]uril as a taste-masking nanocontainer for the first time.

  2. A non-imaging polarized terahertz passive system for detecting and identifying concealed explosives

    NASA Astrophysics Data System (ADS)

    Karam, Mostafa A.; Meyer, Doug

    2011-06-01

    Existing terahertz THz systems for detecting concealed explosives are not capable of identifying explosive type which leads to higher false alarm rates. Moreover, some of those systems are imaging systems that invade personal privacy, and require more processing and computational resources. Other systems have no polarization preference which makes them incapable of capturing the geometric features of an explosive. In this study a non-imaging polarized THz passive system for detecting and identifying concealed explosives overcoming the forgoing shortcomings is developed. The system employs a polarized passive THz sensor in acquiring emitted data from a scene that may have concealed explosives. The acquired data are decomposed into their natural resonance frequencies, and the number of those frequencies is used as criteria in detecting the explosive presence. If the presence of an explosive is confirmed, a set of physically based retrieval algorithms is used in extracting the explosive dielectric constant/refractive index value from natural resonance frequencies and amplitudes of associated signals. Comparing the refractive index value against a database of refractive indexes of known explosives identifies the explosive type. As an application, a system having a dual polarized radiometer operating within the frequency band of 0.62- 0.82 THz is presented and used in detecting and identifying person borne C-4 explosive concealed under a cotton garment. The system showed higher efficiencies in detecting and identifying the explosive.

  3. How Many More Guns?: Estimating the Effect of Allowing Licensed Concealed Handguns on a College Campus

    ERIC Educational Resources Information Center

    Bouffard, Jeffrey A.; Nobles, Matt R.; Wells, William; Cavanaugh, Michael R.

    2012-01-01

    Among other arguments, advocates for lifting bans on carrying concealed handguns on campus propose that this would increase the prevalence of legitimately carried handguns, which might then deter crimes or be used to intervene in campus shooting incidents like the one that took place at Virginia Tech in 2007. Opponents suggest that increased…

  4. Productive and Inclusive? How Documentation Concealed Racialising Practices in a Diversity Project

    ERIC Educational Resources Information Center

    Miller, Melinda G.

    2014-01-01

    This article examines how documentation concealed racialising practices in a diversity project that was seen to be productive and inclusive. Documentation examples are taken from a doctoral study about embedding Indigenous perspectives in early childhood education curricula in two Australian urban childcare centres. In place of reporting examples…

  5. Digital image processing in the SECURE concealed-object detection system

    NASA Astrophysics Data System (ADS)

    Smith, Steven W.

    1993-04-01

    A new technology has been developed for detecting explosives and other dangerous objects concealed under persons' clothing. The 'Subambient Exposure, Computer Utilized Reflected Energy' (SECURE) method uses a very low level of back-scattered x-rays in conjunction with digital image processing to produce an image of the person and any concealed objects. Image processing algorithms, used in the system are directed at presenting information to a human operator in the best possible manner for foreign object detection. These algorithms are viewed as being near optimum, and additional development is probably not justified. Algorithm development is needed in the area of automatic threat detection. This has the potential of reducing the invasion of privacy associated with having a security operator view each image. It also has the potential of reducing the serious problem of operator complacency. In one approach, the new algorithm must (1) recognize and isolate objects in the image, (2) discriminate between concealed objects and human anatomy, and (3) discriminate between dangerous and benign concealed objects. The images produced with the SECURE technology are extremely noisy due to the low levels of radiation used. Any algorithm developed must perform well in this noisy environment. Execution of the algorithm must be accomplished in less than a few seconds. Hardware to implement the algorithm must be of a complexity and cost compatible with the commercial SECURE system.

  6. Fear Perceptions in Public Parks: Interactions of Environmental Concealment, the Presence of People Recreating, and Gender

    ERIC Educational Resources Information Center

    Jorgensen, Lisa J.; Ellis, Gary D.; Ruddell, Edward

    2013-01-01

    This research examined the effect of concealment (environmental cues), presence or absence of people recreating (social cues), and gender on individuals' fear of crime in a community park setting. Using a 7-point single-item indicator, 732 participants from two samples (540 park visitors and 192 college students) rated their estimates of fear of…

  7. University Presidents' Perceptions and Practice Regarding the Carrying of Concealed Handguns on College Campuses

    ERIC Educational Resources Information Center

    Price, James H.; Thompson, Amy; Khubchandani, Jagdish; Dake, Joseph; Payton, Erica; Teeple, Karen

    2014-01-01

    Objective: To assess the perceptions and practices of a national sample of college and university presidents regarding their support for concealed handguns being carried on college campuses. Participants: The sample for this study consisted of a national random sample of 900 college or university presidents. Methods: In the spring of 2013, a…

  8. 36-Month-Olds Conceal Visual and Auditory Information from Others

    ERIC Educational Resources Information Center

    Melis, Alicia P.; Call, Josep; Tomasello, Michael

    2010-01-01

    By three years of age, children are skilled at assessing under which circumstances others can see things. However, nothing is known about whether they can use this knowledge to guide their own deceptive behaviour. Here we investigated 3-year-olds' ability to strategically inhibit or conceal forbidden actions that a nearby adult experimenter could…

  9. [The use of an electric fretsaw for corpse dismemberment and concealment of a crime].

    PubMed

    Nazarov, Iu V; Tolmachev, I A

    2012-01-01

    The authors present an example of forensic medical expertise of the application of a mechanical sawing instrument, in which the reciprocating motion of the cutting edge with respect to the object is guided by the electric motor (electric fretsaw), for the purpose of corpse dismemberment and concealment of a crime.

  10. The Effects of Concealing Academic Achievement Information on Adolescents' Self-Concept

    ERIC Educational Resources Information Center

    Zhang, Baoshan; Wang, Mo; Li, Juan; Yu, Guoliang; Bi, Yan-Ling

    2011-01-01

    Using an experimental design, the effect of concealing academic achievement information on adolescents' self-concept was examined in the current study. Specifically, adolescents with low academic achievement and adolescents with average to high academic achievement (N = 129) were randomly assigned to different interview contexts wherein…

  11. University Presidents' Perceptions and Practice Regarding the Carrying of Concealed Handguns on College Campuses

    ERIC Educational Resources Information Center

    Price, James H.; Thompson, Amy; Khubchandani, Jagdish; Dake, Joseph; Payton, Erica; Teeple, Karen

    2014-01-01

    Objective: To assess the perceptions and practices of a national sample of college and university presidents regarding their support for concealed handguns being carried on college campuses. Participants: The sample for this study consisted of a national random sample of 900 college or university presidents. Methods: In the spring of 2013, a…

  12. Anxiety and Related Disorders and Concealment in Sexual Minority Young Adults.

    PubMed

    Cohen, Jeffrey M; Blasey, Christine; Barr Taylor, C; Weiss, Brandon J; Newman, Michelle G

    2016-01-01

    Sexual minorities face greater exposure to discrimination and rejection than heterosexuals. Given these threats, sexual minorities may engage in sexual orientation concealment in order to avoid danger. This social stigma and minority stress places sexual minorities at risk for anxiety and related disorders. Given that three fourths of anxiety disorder onset occurs before the age of 24, the current study investigated the symptoms of generalized anxiety disorder, social phobia, panic disorder, posttraumatic stress disorder, and depression in sexual minority young adults relative to their heterosexual peers. Secondarily, the study investigated sexual orientation concealment as a predictor of anxiety and related disorders. A sample of 157 sexual minority and 157 heterosexual young adults matched on age and gender completed self-report measures of the aforementioned disorders, and indicated their level of sexual orientation concealment. Results revealed that sexual minority young adults reported greater symptoms relative to heterosexuals across all outcome measures. There were no interactions between sexual minority status and gender, however, women had higher symptoms across all disorders. Sexual minority young women appeared to be at the most risk for clinical levels of anxiety and related disorders. In addition, concealment of sexual orientation significantly predicted symptoms of social phobia. Implications are offered for the cognitive and behavioral treatment of anxiety and related disorders in this population. Copyright © 2015. Published by Elsevier Ltd.

  13. 36-Month-Olds Conceal Visual and Auditory Information from Others

    ERIC Educational Resources Information Center

    Melis, Alicia P.; Call, Josep; Tomasello, Michael

    2010-01-01

    By three years of age, children are skilled at assessing under which circumstances others can see things. However, nothing is known about whether they can use this knowledge to guide their own deceptive behaviour. Here we investigated 3-year-olds' ability to strategically inhibit or conceal forbidden actions that a nearby adult experimenter could…

  14. The Cost of Question Concealment: Eye-Tracking and MEG Evidence

    ERIC Educational Resources Information Center

    Harris, Jesse; Pylkkanen, Liina; McElree, Brian; Frisson, Steven

    2008-01-01

    Although natural language appears to be largely compositional, the meanings of certain expressions cannot be straightforwardly recovered from the meanings of their parts. This study examined the online processing of one such class of expressions: "concealed questions", in which the meaning of a complex noun phrase ("the proof of the theorem")…

  15. Fear Perceptions in Public Parks: Interactions of Environmental Concealment, the Presence of People Recreating, and Gender

    ERIC Educational Resources Information Center

    Jorgensen, Lisa J.; Ellis, Gary D.; Ruddell, Edward

    2013-01-01

    This research examined the effect of concealment (environmental cues), presence or absence of people recreating (social cues), and gender on individuals' fear of crime in a community park setting. Using a 7-point single-item indicator, 732 participants from two samples (540 park visitors and 192 college students) rated their estimates of fear of…

  16. Novel, ERP-based, concealed information detection: Combining recognition-based and feedback-evoked ERPs.

    PubMed

    Sai, Liyang; Lin, Xiaohong; Rosenfeld, J Peter; Sang, Biao; Hu, Xiaoqing; Fu, Genyue

    2016-02-01

    The present study introduced a novel variant of the concealed information test (CIT), called the feedback-CIT. By providing participants with feedbacks regarding their memory concealment performance during the CIT, we investigated the feedback-related neural activity underlying memory concealment. Participants acquired crime-relevant memories via enacting a lab crime, and were tested with the feedback-CIT while EEGs were recorded. We found that probes (e.g., crime-relevant memories) elicited larger recognition-P300s than irrelevants among guilty participants. Moreover, feedback-related negativity (FRN) and feedback-P300 could also discriminate probes from irrelevants among guilty participants. Both recognition- and feedback-ERPs were highly effective in distinguishing between guilty and innocent participants (recognition-P300: AUC=.73; FRN: AUC=.95; feedback-P300: AUC=.97). This study sheds new light on brain-based memory detection, such that feedback-related neural signals can be employed to detect concealed memories.

  17. The Cost of Question Concealment: Eye-Tracking and MEG Evidence

    ERIC Educational Resources Information Center

    Harris, Jesse; Pylkkanen, Liina; McElree, Brian; Frisson, Steven

    2008-01-01

    Although natural language appears to be largely compositional, the meanings of certain expressions cannot be straightforwardly recovered from the meanings of their parts. This study examined the online processing of one such class of expressions: "concealed questions", in which the meaning of a complex noun phrase ("the proof of the theorem")…

  18. Ego Identity, Social Anxiety, Social Support, and Self-Concealment in Lesbian, Gay, and Bisexual Individuals

    ERIC Educational Resources Information Center

    Potoczniak, Daniel J.; Aldea, Mirela A.; DeBlaere, Cirleen

    2007-01-01

    This study examined a model in which the relationship between social anxiety and two dimensions of ego identity (commitment and exploration) was expected to be mediated by social support and self-concealment for a sample of lesbian, gay, and bisexual individuals (N=347). Statistically significant paths were found from social anxiety to social…

  19. Ego Identity, Social Anxiety, Social Support, and Self-Concealment in Lesbian, Gay, and Bisexual Individuals

    ERIC Educational Resources Information Center

    Potoczniak, Daniel J.; Aldea, Mirela A.; DeBlaere, Cirleen

    2007-01-01

    This study examined a model in which the relationship between social anxiety and two dimensions of ego identity (commitment and exploration) was expected to be mediated by social support and self-concealment for a sample of lesbian, gay, and bisexual individuals (N=347). Statistically significant paths were found from social anxiety to social…

  20. Productive and Inclusive? How Documentation Concealed Racialising Practices in a Diversity Project

    ERIC Educational Resources Information Center

    Miller, Melinda G.

    2014-01-01

    This article examines how documentation concealed racialising practices in a diversity project that was seen to be productive and inclusive. Documentation examples are taken from a doctoral study about embedding Indigenous perspectives in early childhood education curricula in two Australian urban childcare centres. In place of reporting examples…

  1. Cancer survivors' concealment or disclosure of diagnosis: Implications for return to work.

    PubMed

    Morrison, T L; Thomas, R L

    2015-01-01

    The ability to return to work (RTW) is a significant quality of life indicator for many working aged cancer survivors. In the void of available support, many are left to independently navigate the RTW process which includes such important considerations as disclosure or concealment of diagnosis with concomitant sequellae. This article reviews participants' variable approaches to concealment, disclosure, or even an open educative stance as well as the associated benefits and limitations. Photovoice methods combined with interviewing. While most participants disclosed their diagnosis and many extolled the benefits of an open, educative stance, there were drawbacks experienced. Similarly, those who concealed their diagnosis also experienced benefits and challenges. In the current void of appropriate cancer rehabilitation supports, cancer survivors must independently negotiate their RTW process. Although most participants openly disclosed their diagnosis and associated limitations, a few concealed or camouflaged. There are benefits and limitations to both approaches of which survivors should be made aware at the outset as such will shape their RTW experience. Multidisciplinary rehabilitation support services would best guide survivors' management of the myriad of factors that will impact their work reintegration.

  2. Concealment of the Warfighter’s Equipment Through Enhanced Polymer Technology

    DTIC Science & Technology

    2004-12-01

    CONCEALMENT OF THE WARFIGHTER’S EQUIPMENT THROUGH ENHANCED POLYMER TECHNOLOGY Kevin Frankel* INVISTA Wilmington, DE 19805 Sonia Sousa INVISTA Sabine...Michael Codega and James Zheng at the U.S. Army Natick Soldier Center for their product manager leads in developing warfighter’s clothing and

  3. A time period study on the efficiency of luminol in the detection of bloodstains concealed by paint on different surfaces.

    PubMed

    Nagesh, Deepthi; Ghosh, Shayani

    2017-02-11

    Forensic Science is the application of science to the criminal and civil laws that are enforced by police agencies in a criminal justice system. It is a science which relies on physical evidence; one of the important physical evidences being blood. The purpose of this research was to determine the efficacy of luminol reagent in detecting bloodstains on different surfaces, concealed by multiple layers of paint, over a period of time and also to compare the intensities of chemiluminescence exhibited by them. In this study, dry wall, wooden planks and metal surfaces were identified as commonly encountered surfaces at crime scenes and hence 25 of each surface were simulated and blood was spattered, which were then concealed by progressive layers of paint specific to each surface. Thereafter, each surface was critically observed for the intensity of chemiluminescence, following the application of luminol and the results were documented as photographs. The research was conducted for duration of 50 days, in order to study the effect of ageing of concealment upon detection of bloodstains using luminol. Varying intensities of chemiluminescence were displayed by all the three simulated surfaces deposited with paint over bloodstains up to three layers of concealment, depending on the nature of the surface which were captured using photography. The highest intensity of chemiluminescence was shown by concealed bloodstains on dry wall and metal surfaces, despite the number of layers of concealment. However, an increase in the number of layers of concealment produced a significant decrease in the intensity of chemiluminescenece displayed by the bloodstains concealed by paint upon reacting with luminol on metal sheets, which was not found to be uniform and consistent on the other surfaces. These findings highlight the fact that bloodstains concealed by paint could be effectively detected by luminol reagent, despite the nature and ageing of concealment and thereby provide a lead to

  4. Using fMRI to decode true thoughts independent of intention to conceal

    PubMed Central

    Yang, Zhi; Huang, Zirui; Gonzalez-Castillo, Javier; Dai, Rui; Northoff, Georg; Bandettini, Peter

    2014-01-01

    Multi-variate pattern analysis (MVPA) applied to BOLD-fMRI has proven successful at decoding complicated fMRI signal patterns associated with a variety of cognitive processes. One cognitive process, not yet investigated, is the mental representation of “Yes/No” thoughts that precede the actual overt response to a binary “Yes/No” question. In this study, we focus on examining: (1) whether spatial patterns of the hemodynamic response carry sufficient information to allow reliable decoding of “Yes/No” thoughts; and (2) whether decoding of “Yes/No” thoughts is independent of the intention to respond honestly or dishonestly. To achieve this goal, we conducted two separate experiments. Experiment 1, collected on a 3T scanner, examined the whole brain to identify regions that carry sufficient information to permit significantly above-chance prediction of “Yes/No” thoughts at the group level. In Experiment 2, collected on a 7T scanner, we focused on the regions identified in Experiment 1 to examine the capability of achieving high decoding accuracy at the single subject level. A set of regions—namely right superior temporal gyrus, left supra-marginal gyrus, and left middle frontal gyrus—exhibited high decoding power. Decoding accuracy for these regions increased with trial averaging. When 18 trials were averaged, the median accuracies were 82.5%, 77.5%, and 79.5%, respectively. When trials were separated according to deceptive intentions (set via experimental cues), and classifiers were trained on honest trials, but tested on trials where subjects were asked to deceive, the median accuracies of these regions still reached 66%, 75%, and 78.5%. These results provide evidence that concealed “Yes/No” thoughts are encoded in the BOLD signal, retaining some level of independence from the subject’s intentions to answer honestly or dishonestly. These findings also suggest the theoretical possibility for more efficient brain-computer interfaces where

  5. Smoothing error pitfalls

    NASA Astrophysics Data System (ADS)

    von Clarmann, T.

    2014-09-01

    The difference due to the content of a priori information between a constrained retrieval and the true atmospheric state is usually represented by a diagnostic quantity called smoothing error. In this paper it is shown that, regardless of the usefulness of the smoothing error as a diagnostic tool in its own right, the concept of the smoothing error as a component of the retrieval error budget is questionable because it is not compliant with Gaussian error propagation. The reason for this is that the smoothing error does not represent the expected deviation of the retrieval from the true state but the expected deviation of the retrieval from the atmospheric state sampled on an arbitrary grid, which is itself a smoothed representation of the true state; in other words, to characterize the full loss of information with respect to the true atmosphere, the effect of the representation of the atmospheric state on a finite grid also needs to be considered. The idea of a sufficiently fine sampling of this reference atmospheric state is problematic because atmospheric variability occurs on all scales, implying that there is no limit beyond which the sampling is fine enough. Even the idealization of infinitesimally fine sampling of the reference state does not help, because the smoothing error is applied to quantities which are only defined in a statistical sense, which implies that a finite volume of sufficient spatial extent is needed to meaningfully discuss temperature or concentration. Smoothing differences, however, which play a role when measurements are compared, are still a useful quantity if the covariance matrix involved has been evaluated on the comparison grid rather than resulting from interpolation and if the averaging kernel matrices have been evaluated on a grid fine enough to capture all atmospheric variations that the instruments are sensitive to. This is, under the assumptions stated, because the undefined component of the smoothing error, which is the

  6. Out and healthy: Being more "out" about a concealable stigmatized identity may boost the health benefits of social support.

    PubMed

    Weisz, Bradley M; Quinn, Diane M; Williams, Michelle K

    2016-12-01

    This research examined whether the relationship between perceived social support and health would be moderated by level of outness for people living with different concealable stigmatized identities (mental illness, substance abuse, domestic violence, rape, or childhood abuse). A total of 394 people living with a concealable stigmatized identity completed a survey. Consistent with hypotheses, at high levels of outness, social support predicted better health; at low levels of outness, social support was less predictive of health. People concealing a stigmatized identity may only be able to reap the health benefits of social support if they are "out" about the stigmatized identity.

  7. Error resilient video coding using virtual reference picture

    NASA Astrophysics Data System (ADS)

    Zhang, Guanjun; Stevenson, Robert L.

    2005-03-01

    Due to widely used motion-compensated prediction coding, errors propagate along decoded video sequence and may result in severe quality degradation. Various methods have been reported to address this problem based on the common idea of diversifying prediction references. In this paper, we present an alternative way of concealing the references pictures errors. A generated virtual picture is used as a reference instead of an actual sequence picture in the temporal prediction. The virtual reference picture is generated in a way to filter damaged parts of previously decoded pictures so that the decoder can still get a clean reference picture in case of errors. Coding efficiency is effected due to the fact that the virtual reference is less correlated to the currently encoded picture. The simulations on H.264 codec have shown quality improvement of the proposed method over intra-coded macroblock refreshment. It can be used on any motion-compensated video codec to combat channel errors.

  8. A mock terrorism application of the P300-based concealed information test.

    PubMed

    Meixner, John B; Rosenfeld, J Peter

    2011-02-01

    Previous studies examining the P300-based concealed information test typically tested for mock crime or autobiographical details, but no studies have used this test in a counterterrorism scenario. Subjects in the present study covertly planned a mock terrorist attack on a major city. They were then given three separate blocks of concealed information testing, examining for knowledge of the location, method, and date of the planned terrorist attack, using the Complex Trial Protocol (Rosenfeld et al., 2008). With prior knowledge of the probe items, we detected 12/12 guilty subjects as having knowledge of the planned terrorist attack with no false positives among 12 innocent subjects. Additionally, we were able to identify 10/12 subjects and among them 20/30 crime-related details with no false positives using restricted a priori knowledge of the crime details, suggesting that the protocol could potentially identify future terrorist activity.

  9. Concealed threat detection with the IRAD sub-millimeter wave 3D imaging radar

    NASA Astrophysics Data System (ADS)

    Robertson, Duncan A.; Cassidy, Scott L.; Jones, Ben; Clark, Anthony

    2014-06-01

    Sub-millimeter wave 3D imaging radar is a promising technology for the stand-off detection of threats concealed on people. The IRAD 340 GHz 3D imaging radar uses polarization intensity information to identify signatures associated with concealed threats. We report on an extensive trials program which has been carried out involving dozens of individual subjects wearing a variety of different clothing to evaluate the detection of a wide range of threat and benign items. We have developed an automatic algorithm to run on the radar which yields a level of anomaly indication in real time. Statistical analysis of the large volume of recorded data has enabled performance metrics for the radar system to be evaluated.

  10. Identifying the location of a concealed object through unintentional eye movements

    PubMed Central

    Neuman, Yair; Assaf, Dan; Israeli, Navot

    2015-01-01

    In some investigative and interrogative contexts, the investigator is seeking to identify the location of an object (e.g., implanted bomb) which is known to a given subject (e.g., a terrorist). In this paper, we present a non-intrusive methodology for uncovering the loci of a concealed object by analyzing the subject's eye movements. Using a combination of eye tracking, psychological manipulation and a search algorithm, we have performed two experiments. In the first experiment, we have gained 58% hit rate in identifying the location of the concealed object and in the second experiment 56% hit rate. The pros and cons of the methodology for forensic investigation are discussed. PMID:25904879

  11. University presidents' perceptions and practice regarding the carrying of concealed handguns on college campuses.

    PubMed

    Price, James H; Thompson, Amy; Khubchandani, Jagdish; Dake, Joseph; Payton, Erica; Teeple, Karen

    2014-01-01

    To assess the perceptions and practices of a national sample of college and university presidents regarding their support for concealed handguns being carried on college campuses. The sample for this study consisted of a national random sample of 900 college or university presidents. In the spring of 2013, a 3-wave mailing procedure was used to ensure an adequate response rate to a valid and reliable questionnaire. The response rate was 46%, more than what was needed based on the power analysis. The vast majority (95%) of respondents were not supportive of carrying concealed handguns on campuses. They perceived there to be more disadvantages than advantages to handguns on campus. However, college administrators were not focused enough on the primary prevention of campus firearm trauma. The findings of this study suggest a number of activities that could be implemented to enhance safety on college and university campuses.

  12. Is human ovulation concealed? Evidence from conception beliefs in a hunter-gatherer society.

    PubMed

    Marlowe, Frank W

    2004-10-01

    Several researchers have suggested that ovulation may not be concealed in humans living under natural conditions with minimal hygiene. Because measuring coital frequency in such a population is problematic, I tested this proposition indirectly by asking Hadza hunter-gatherers of Tanzania when a woman can get pregnant. If people (1) know that pregnancy is caused by sex, and people (2) say that women conceive in the middle of the menstrual cycle, we might infer that people think women conceive in the middle of the cycle because most copulations occur then. If copulation peaks strongly around ovulation, it is not concealed. The Hadza know that pregnancy is caused by sex but most say conception occurs right after menstruation ends. Hadza conception beliefs therefore do not suggest that ovulation is more detectable in humans under more natural conditions. Copyright 2004 Springer Science + Business Media, Inc.

  13. Spatial Error Metrics for Oceanographic Model Verification

    DTIC Science & Technology

    2012-02-01

    results show that the registration process, once tuned, works quantitatively and qualitatively for this oceano - graphic data and successfully separates the...dimensional (3D) medical imagery, and should be possible for oceano - graphic models as well, though one would likely need to make special modifications

  14. Antidromic Atrioventricular Reciprocating Tachycardia Using a Concealed Retrograde Conducting Left Lateral Accessory Pathway.

    PubMed

    Gonzalez, Jaime E; Zipse, Matthew M; Nguyen, Duy T; Sauer, William H

    2016-03-01

    Atrioventricular reciprocating tachycardia is a common cause of undifferentiated supraventricular tachycardia. In patients with manifest or concealed accessory pathways, it is imperative to assess for the presence of other accessory pathways. Multiple accessory pathways are present in 4% to 10% of patients and are more common in patients with structural heart disease. In rare cases, multiple accessory pathways can act as the anterograde and retrograde limbs of the tachycardia.

  15. [Analysis of forensic-medical expert conclusions on rap and concealed rape (data from anonymous questionnaires)].

    PubMed

    Pigolkin, Iu I; Dmitrieva, O A

    2001-01-01

    Specific features of modern cases of raping are analyzed on the basis of the data of forensic medical obstetrical and gynecological expert evaluations carried out in the Primorye territory. Age and risk groups are defined, health status of victims is characterized, and specific injuries of the body and genitals are described. Specific features of concealed sexual violations in Vladivostok are defined and the need in creation of rehabilitation centers for victims of raping is discussed.

  16. Fiber Optic Coupled Raman Based Detection of Hazardous Liquids Concealed in Commercial Products

    DTIC Science & Technology

    2012-01-01

    Detecting explosives by portable Raman ana- lyzers: a comparison of 785, 976, 1064 ,and 1550 nm (Retina- Safe) laser excitation,” Spectroscopy, pp...agent (CWA) simulant triethyl phosphate (TEP), hydrogen peroxide, and acetone as representative of toxic industrial compounds (TICs). Fiber optic...distribution is unlimited. Fiber Optic Coupled Raman Based Detection of Hazardous Liquids Concealed in Commercial Products The views, opinions and/or

  17. Unraveling the roles of orienting and inhibition in the Concealed Information Test.

    PubMed

    Klein Selle, Nathalie; Verschuere, Bruno; Kindt, Merel; Meijer, Ewout; Ben-Shakhar, Gershon

    2017-04-01

    The Concealed Information Test (CIT) is a well-validated tool for physiological and behavioral detection of concealed knowledge. Two distinct theoretical frameworks have been proposed to explain the differential responses to the concealed critical items: orienting response theory versus arousal inhibition theory. klein Selle, Verschuere, Kindt, Meijer, and Ben-Shakhar (2016), however, argued for a response fractionation model and showed that, while the skin conductance reflects pure orienting, both the respiratory and heart rate measures reflect arousal inhibition. The present study intends to (1) provide a constructive replication of klein Selle et al. (2016) using the autobiographical CIT, and (2) extend their work by testing an additional prediction derived from orienting theory, using an item-salience manipulation. One hundred and nine participants were tested on four high salient and four low salient identity items. Half of the participants were motivated to hide their identity (orienting + arousal inhibition), while the other half were motivated to reveal their identity (orienting only). Confirming earlier findings, the results revealed a fractionation between the different measures: while the skin conductance response (SCR) increased to a similar extent in the two motivational conditions, the respiration line length (RLL) shortened and the heart rate (HR) decelerated solely in the conceal condition. Moreover, while the SCR was larger for high than for low salient critical items, the RLL and HR responses were similar for these two item types. These data led us to conclude that, in the CIT, the skin conductance measure reflects orienting and the respiratory and heart rate measures reflect arousal inhibition.

  18. Is anterior N2 enhancement a reliable electrophysiological index of concealed information?

    PubMed

    Ganis, Giorgio; Bridges, David; Hsu, Chun-Wei; Schendan, Haline E

    2016-12-01

    Concealed information tests (CITs) are used to determine whether an individual possesses information about an item of interest. Event-related potential (ERP) measures in CITs have focused almost exclusively on the P3b component, showing that this component is larger when lying about the item of interest (probe) than telling the truth about control items (irrelevants). Recent studies have begun to examine other ERP components, such as the anterior N2, with mixed results. A seminal CIT study found that visual probes elicit a larger anterior N2 than irrelevants (Gamer and Berti, 2010) and suggested that this component indexes cognitive control processes engaged when lying about probes. However, this study did not control for potential intrinsic differences among the stimuli: the same probe and irrelevants were used for all participants, and there was no control condition composed of uninformed participants. Here, first we show that the N2 effect found in the study by Gamer and Berti (2010) was in large part due to stimulus differences, as the effect observed in a concealed information condition was comparable to that found in two matched control conditions without any concealed information (Experiments 1 and 2). Next, we addressed the issue of the generality of the N2 findings by counterbalancing a new set of stimuli across participants and by using a control condition with uninformed participants (Experiment 3). Results show that the probe did not elicit a larger anterior N2 than the irrelevants under these controlled conditions. These findings suggest that caution should be taken in using the N2 as an index of concealed information in CITs. Furthermore, they are a reminder that results of CIT studies (not only with ERPs) performed without stimulus counterbalancing and suitable control conditions may be confounded by differential intrinsic properties of the stimuli employed. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Detection of concealed information by P3 and frontal EEG asymmetry.

    PubMed

    Matsuda, Izumi; Nittono, Hiroshi; Allen, John J B

    2013-03-14

    Psychophysiological detection of deception has seen increased attention in both research and applied settings. In this field, the most scientifically validated paradigm is the Concealed Information Test (CIT). The CIT does not directly deal with whether a participant is lying, but examines whether a participant recognizes a critical relevant detail, inferred by differences in physiological responses between critical and non-critical items. Although event-related potential (ERP) approaches to the CIT have shown high accuracy, a combination of measures might improve the test's performance. We thus assessed whether a new CIT index, frontal EEG asymmetry that is supposed to reflect differences in approach/withdrawal motivation, would prove useful. Nineteen participants were asked to steal one item in a mock crime, and were then administered two CITs while concealing the stolen item. One CIT included the stolen item (i.e., guilty condition), whereas the other CIT did not (i.e., innocent condition). In the guilty condition, the concealed stolen item elicited greater relative left frontal alpha activity (indicative of relative right frontal cortical activity) as compared to the other items, suggesting that the recognition of the concealed item might have induced withdrawal motivation. Although the discrimination between guilty and innocent conditions by the asymmetry score alone was not as good as that by the ERP P3 index, combining the asymmetry score and P3 improved the detection performance significantly. The results suggest that the frontal EEG asymmetry can be used as a new measure in the CIT that provides additional information beyond that captured by the traditional ERP index.

  20. ARPA/NIJ/Rome Laboratory concealed weapon detection program: an overview

    NASA Astrophysics Data System (ADS)

    Currie, Nicholas C.; Demma, Fred J.; Ferris, David D., Jr.; McMillan, Robert W.; Wicks, Michael C.

    1996-06-01

    Recent advances in passive and active imaging and non- imaging sensor technology offer the potential to detect weapons that are concealed beneath a person's clothing. Sensors that are discussed in this paper are characterized as either non-imaging or imaging. Non-imaging sensors include wide band radar and portal devices such as metal detectors. In general the strength of non-imaging sensors rest with the fact that they are generally inexpensive and can rapidly perform bulk separation between regions where persons are likely to be carrying concealed weapons and those regions that are likely to contain persons who are unarmed. The bulk process is typically accomplished at the expense of false alarm rate. Millimeter-wave (MMW), microwave, x-ray, acoustic, magnetic, and infrared (IR) imaging sensor technologies provide with greater certainty the means to isolate persons within a crowd that are carrying concealed weapons and to identify the weapon type. The increased certainty associated with imaging sensors is accomplished at the expense of cost and bulk surveillance of the crowd. CWD technologies have a variety of military and civilian applications. This technology focus area addresses specific military needs under the Defense Advanced Research Projects Agency's (DARPA) operations other than war/law enforcement (OOTW/LE). Additionally, this technology has numerous civilian law enforcement applications that are being investigated under the National Institute of Justice's (NIJ) Concealed Weapons Detection program. This paper discusses the wide variety of sensors that might be employed in support of a typical scenario, the strengths and weaknesses of each of the sensors relative to the given scenario, and how CWD breadboards will be tested to determine the optimal CWD application. It rapidly becomes apparent that no single sensor will completely satisfy the CWD mission necessitating the fusion of two or more of these sensors.

  1. Image fusion based on millimeter-wave for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Zhu, Weiwen; Zhao, Yuejin; Deng, Chao; Zhang, Cunlin; Zhang, Yalin; Zhang, Jingshui

    2010-11-01

    This paper describes a novel multi sensors image fusion technology which is presented for concealed weapon detection (CWD). It is known to all, because of the good transparency of the clothes at millimeter wave band, a millimeter wave radiometer can be used to image and distinguish concealed contraband beneath clothes, for example guns, knives, detonator and so on. As a result, we adopt the passive millimeter wave (PMMW) imaging technology for airport security. However, in consideration of the wavelength of millimeter wave and the single channel mechanical scanning, the millimeter wave image has law optical resolution, which can't meet the need of practical application. Therefore, visible image (VI), which has higher resolution, is proposed for the image fusion with the millimeter wave image to enhance the readability. Before the image fusion, a novel image pre-processing which specifics to the fusion of millimeter wave imaging and visible image is adopted. And in the process of image fusion, multi resolution analysis (MRA) based on Wavelet Transform (WT) is adopted. In this way, the experiment result shows that this method has advantages in concealed weapon detection and has practical significance.

  2. Stepped-frequency CW radar for concealed weapon detection and through-the-wall surveillance

    NASA Astrophysics Data System (ADS)

    Hunt, Allen R.; Hogg, R. Douglas

    2002-08-01

    Both concealed weapons detection and through the wall surveillance are significant problems for both law enforcement and military personnel. While on the surface it would appear that these two problems are unrelated technologically, they do, in fact, share some common ground. A concealed weapon acts as resonant object, exhibiting electromagnetic resonance peaks at frequencies characteristic of the weapon's major dimensions. For handguns the frequency range of interest lies approximately between 450 MHz and 2 GHz. As it turns out, this is also a region over which many common building materials are largely transparent. As part of grant 97-IJ-CX-K013 from the National Institute of Justice, AKELA, Inc. has developed a stepped-frequency, CW radar that covers this frequency range. The radar is digitally synthesized and controlled and has a range resolution of approximately 4'. Digital waveform control gives the radar the ability to avoid interference with other electronic devices, to tailor data collection for signal processing requirements, and to change its sweep time in response to operational requirements. AKELA has developed a brassboard concealed weapons detector that uses this radar. A through the wall imaging system that uses the radar is currently in development under AFRL Contract F30602-00-C-0205.

  3. Preventing Shoulder-Surfing Attack with the Concept of Concealing the Password Objects' Information

    PubMed Central

    Ho, Peng Foong; Kam, Yvonne Hwei-Syn; Wee, Mee Chin

    2014-01-01

    Traditionally, picture-based password systems employ password objects (pictures/icons/symbols) as input during an authentication session, thus making them vulnerable to “shoulder-surfing” attack because the visual interface by function is easily observed by others. Recent software-based approaches attempt to minimize this threat by requiring users to enter their passwords indirectly by performing certain mental tasks to derive the indirect password, thus concealing the user's actual password. However, weaknesses in the positioning of distracter and password objects introduce usability and security issues. In this paper, a new method, which conceals information about the password objects as much as possible, is proposed. Besides concealing the password objects and the number of password objects, the proposed method allows both password and distracter objects to be used as the challenge set's input. The correctly entered password appears to be random and can only be derived with the knowledge of the full set of password objects. Therefore, it would be difficult for a shoulder-surfing adversary to identify the user's actual password. Simulation results indicate that the correct input object and its location are random for each challenge set, thus preventing frequency of occurrence analysis attack. User study results show that the proposed method is able to prevent shoulder-surfing attack. PMID:24991649

  4. Concealed neuroanatomy in Michelangelo's Separation of Light From Darkness in the Sistine Chapel.

    PubMed

    Suk, Ian; Tamargo, Rafael J

    2010-05-01

    Michelangelo Buonarroti (1475-1564) was a master anatomist as well as an artistic genius. He dissected cadavers numerous times and developed a profound understanding of human anatomy. From 1508 to 1512, Michelangelo painted the ceiling of the Sistine Chapel in Rome. His Sistine Chapel frescoes are considered one of the monumental achievements of Renaissance art. In the winter of 1511, Michelangelo entered the final stages of the Sistine Chapel project and painted 4 frescoes along the longitudinal apex of the vault, which completed a series of 9 central panels depicting scenes from the Book of Genesis. It is reported that Michelangelo concealed an image of the brain in the first of these last 4 panels, namely, the Creation of Adam. Here we present evidence that he concealed another neuronanatomic structure in the final panel of this series, the Separation of Light From Darkness, specifically a ventral view of the brainstem. The Separation of Light From Darkness is an important panel in the Sistine Chapel iconography because it depicts the beginning of Creation and is located directly above the altar. We propose that Michelangelo, a deeply religious man and an accomplished anatomist, intended to enhance the meaning of this iconographically critical panel and possibly document his anatomic accomplishments by concealing this sophisticated neuroanatomic rendering within the image of God.

  5. Hydrogeological Studies to Identify the Trend of Concealed Section of the North Tabriz Fault (Iran).

    PubMed

    Rajabpour, Hossein; Vaezihir, Abdorreza

    2017-05-01

    The North Tabriz Fault (NTF) is the predominant regional-scale tectonic structure in the northwest of Iran. In the east side of the city of Tabriz, a portion of the fault trend has been completely concealed by recent sediments and urbanization. In this paper, some hydrogeological methods are used to locate the concealed sector. As is clear from the pumping tests results, despite the fact that the northern observation wells were closer to the pumping wells than the southern ones, they have not been affected by pumping. Conversely, all southern wells were affected by pumping and displayed decline of the water table. In addition, obvious differences in groundwater levels combined with clear differences in groundwater quality within a short distance across the probable fault trend are sufficient reasons for the presence of the fault that behaves as a barrier to groundwater lateral flows. Significant change in the elevation of the bedrock base of the aquifer over less than 200 m suggests that the fault has near vertical dip. These results indicate that the inferred trend of the NTF closely conforms to its actual trend. Therefore, the hydrogeological studies can be complementary tools to determine the position and trend of concealed faults. © 2016, National Ground Water Association.

  6. Preventing shoulder-surfing attack with the concept of concealing the password objects' information.

    PubMed

    Ho, Peng Foong; Kam, Yvonne Hwei-Syn; Wee, Mee Chin; Chong, Yu Nam; Por, Lip Yee

    2014-01-01

    Traditionally, picture-based password systems employ password objects (pictures/icons/symbols) as input during an authentication session, thus making them vulnerable to "shoulder-surfing" attack because the visual interface by function is easily observed by others. Recent software-based approaches attempt to minimize this threat by requiring users to enter their passwords indirectly by performing certain mental tasks to derive the indirect password, thus concealing the user's actual password. However, weaknesses in the positioning of distracter and password objects introduce usability and security issues. In this paper, a new method, which conceals information about the password objects as much as possible, is proposed. Besides concealing the password objects and the number of password objects, the proposed method allows both password and distracter objects to be used as the challenge set's input. The correctly entered password appears to be random and can only be derived with the knowledge of the full set of password objects. Therefore, it would be difficult for a shoulder-surfing adversary to identify the user's actual password. Simulation results indicate that the correct input object and its location are random for each challenge set, thus preventing frequency of occurrence analysis attack. User study results show that the proposed method is able to prevent shoulder-surfing attack.

  7. [Intraoperative asystole in a patient with concealed sick sinus syndrome: a case report].

    PubMed

    Shirasaka, Wataru; Ikeshita, Kazutoshi; Toriyama, Sumiko; Yamashita, Tomoyuki; Tani, Yoshiyuki

    2014-03-01

    We report a patient with concealed sick sinus syndrome who developed intraoperative bradycardia and asystole. An 81-year-old man was scheduled to undergo total gastrectomy under general and epidural anesthesia. There was no history of syncope, and preoperative 12-lead ECG showed normal sinus rhythm. Anesthesia was induced with propofol and remifentanil, maintained with sevoflurane, remifentanil and thoracic epidural infusion of lidocaine, fentanyl and levobupivacaine. Bradycardia was detected on ECG 110 minutes after the start of surgery. Intravenous atropine (0.5 mg, repeated up to a total dose of 1.5 mg) was ineffective in restoring a normal heart rhythm. Ten minutes later, the ECG changed to asystole lasting for about 15 seconds. Regular chest compression and intravenous administration of dopamine (5 microg x kg(-1) x min(-1)) resulted in successful recovery of sinus rhythm. Postoperative ECG showed sinus rhythm. The final diagnosis by a cardiologist was concealed sick sinus syndrome. Many anesthetic agents have some effects on the cardiac conduction system. Remifentanil may have played a role in the development of asystole in this patient. The existence of concealed sick sinus syndrome should be kept in mind even in patients who show no clinical abnormalities on preoperative assessment.

  8. Active wideband 350GHz imaging system for concealed-weapon detection

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.; McMakin, Douglas L.; Hatchell, Brian K.; Valdez, Patrick L. J.

    2009-05-01

    A prototype active wideband 350 GHz imaging system has been developed to address the urgent need for standoff concealed-weapon detection. This system is based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed conical scanner. This system is able to quickly scan personnel for concealed weapons. Additionally, due to the wideband operation, this system provides accurate ranging information, and the images obtained are fully three-dimensional. Waves in the microwave, millimeter-wave, and terahertz (3 GHz to 1 THz) frequency bands are able to penetrate many optical obscurants, and can be used to form the basis of high-resolution imaging systems. Waves in the sub-millimeter-wave band (300 GHz to 1 THz) are particularly interesting for standoff concealed-weapon detection at ranges of 5 - 20+ meters, due to their unique combination of high resolution and clothing penetration. The Pacific Northwest National Laboratory (PNNL) has previously developed portal screening systems that operate at the lower end of the millimeter-wave frequency range around 30 GHz. These systems are well suited for screening within portals; however, increasing the range of these systems would dramatically reduce the resolution due to diffraction at their relatively long wavelength. In this paper, the standoff 350 GHz imaging system is described in detail and numerous imaging results are presented.

  9. Three-Dimensional Millimeter-wave Imaging for Concealed Weapon Detection

    SciTech Connect

    Sheen, David M. ); McMakin, Douglas L. ); Hall, Thomas E. )

    2000-12-01

    Millimeter-wave imaging techniques and systems have been developed at the Pacific Northwest National Laboratory (PNNL) for the detection of concealed weapons and contraband at airports and other secure locations. These techniques were derived from microwave holography techniques which utilize phase and amplitude information recorded over a two-dimensional aperture to reconstruct a focused image of the target. Millimeter-wave imaging is well suited to the detection of concealed weapons or other contraband carried on personnel since millimeter-waves are non-ionizing, readily penetrate common clothing material, and are reflected from the human body and any concealed items. In this paper, a wide-bandwidth, three-dimensional, holographic microwave imaging technique is described. Practical weapon detection systems for airport, or other high-throughput applications, require high-speed scanning on the order of 3 to 10 seconds. To achieve this goal, a prototype imaging system utilizing a 2 7-33 GHz linear sequentially switched array and a high-speed linear scanner has been developed and tested. This system is described in detail along with numerous imaging results.

  10. Fixations and eye-blinks allow for detecting concealed crime related memories.

    PubMed

    Peth, Judith; Kim, Johann S C; Gamer, Matthias

    2013-04-01

    The Concealed Information Test (CIT) is a method of forensic psychophysiology that allows for revealing concealed crime related knowledge. Such detection is usually based on autonomic responses but there is a huge interest in other measures that can be acquired unobtrusively. Eye movements and blinks might be such measures but their validity is unclear. Using a mock crime procedure with a manipulation of the arousal during the crime as well as the delay between crime and CIT, we tested whether eye tracking measures allow for detecting concealed knowledge. Guilty participants showed fewer but longer fixations on central crime details and this effect was even present after stimulus offset and accompanied by a reduced blink rate. These ocular measures were partly sensitive for induction of emotional arousal and time of testing. Validity estimates were moderate but indicate that a significant differentiation between guilty and innocent subjects is possible. Future research should further investigate validity differences between gaze measures during a CIT and explore the underlying mechanisms.

  11. [Management of moderate to severe pediatric concealed penis in children by Devine's technique via incision between the penis and scrotum].

    PubMed

    Zhang, Xin-Sheng; Liu, Shi-Xiong; Xiang, Xue-Yan; Zhang, Wen-Gang; Tang, Da-Xing

    2014-04-01

    To search for a simple and effective surgical approach to the management of moderate to severe pediatric concealed penis in children. We used Devine's technique via incision between the penis and scrotum in the treatment of 68 cases of moderate to severe pediatric concealed penis. The patients were aged 3 -13 (mean 6.5) years, 30 with moderate and 38 with severe pediatric concealed penis. This strategy achieved good near- and long-term effects and satisfactory appearance of the penis, which was similar to that of circumcision. At 3 months after surgery, the penile length was 3 - 5.2 cm, averaging (2.35 +/- 0.35) cm. Devine's technique via incision between the penis and scrotum is a simple and effective surgical option for moderate to severe pediatric concealed penis in children.

  12. Disclosure and Concealment of Sexual Orientation and the Mental Health of Non-Gay-Identified, Behaviorally-Bisexual Men

    PubMed Central

    Schrimshaw, Eric W.; Siegel, Karolynn; Downing, Martin J.; Parsons, Jeffrey T.

    2013-01-01

    Objective Although bisexual men report lower levels of mental health relative to gay men, few studies have examined the factors that contribute to bisexual men’s mental health. Bisexual men are less likely to disclose, and more likely to conceal (i.e., a desire to hide), their sexual orientation than gay men. Theory suggests that this may adversely impact their mental health. This report examined the factors associated with disclosure and with concealment of sexual orientation, the association of disclosure and concealment with mental health, and the potential mediators (i.e., internalized homophobia, social support) of this association with mental health. Method An ethnically-diverse sample of 203 non-gay-identified, behaviorally-bisexual men who do not disclose their same-sex behavior to their female partners were recruited in New York City to complete a single set of self-report measures. Results Concealment was associated with higher income, a heterosexual identification, living with a wife or girlfriend, more frequent sex with women, and less frequent sex with men. Greater concealment, but not disclosure to friends and family, was significantly associated with lower levels of mental health. Multiple mediation analyses revealed that both internalized homophobia and general emotional support significantly mediated the association between concealment and mental health. Conclusions The findings demonstrate that concealment and disclosure are independent constructs among bisexual men. Further, they suggest that interventions addressing concerns about concealment, emotional support, and internalized homophobia may be more beneficial for increasing the mental health of bisexual men than those focused on promoting disclosure. PMID:23276123

  13. Direct and indirect links between parenting styles, self-concealment (secrets), impaired control over drinking and alcohol-related outcomes.

    PubMed

    Hartman, Jessica D; Patock-Peckham, Julie A; Corbin, William R; Gates, Jonathan R; Leeman, Robert F; Luk, Jeremy W; King, Kevin M

    2015-01-01

    Self-concealment reflects uncomfortable feelings, thoughts, and information people have about themselves that they avoid telling others (Larson & Chastain, 1990). According to Larson and Chastain (1990) these secrets range from the slightly embarrassing to the very distressing with an individual's most traumatic experiences often concealed. Parental attitudes including those involving self-disclosure are thought to be expressed in their choice of parenting style (Brand, Hatzinger, Beck, & Holsboer-Trachsler, 2009). The specific aim of this investigation was to examine the direct and indirect influences of parenting styles on self-concealment, impaired control over drinking (i.e. the inability to stop drinking when intended), alcohol use (quantity/frequency), and alcohol-related problems. A structural equation model with 419 (223 men, 196 women) university students was examined. Two and three path mediated effects were examined with the bias corrected bootstrap technique in Mplus. Having an authoritarian mother was directly linked to more self-concealment, while having an authoritative father was directly linked to less self-concealment. Higher levels of mother authoritarianism were indirectly linked to both increased alcohol use and alcohol-related problems through more self-concealment and more impaired control over drinking. Moreover, higher levels of father authoritativeness were indirectly linked to less alcohol use and alcohol-related problems through less self-concealment and less impaired control over drinking. These findings suggest that parenting styles influence vulnerabilities such as self-concealment in the impaired control over the drinking pathway to alcohol use and alcohol-related problems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Clothing adjustments for concealed soft body armor during moderate physical exertion.

    PubMed

    Ryan, Greg A; Bishop, Stacy H; Herron, Robert L; Katica, Charles P; Elbon, Bre'anna L; Bosak, Andrew M; Bishop, Phillip

    2015-01-01

    Previous research has studied the impact of Level II concealed soft body armor (SBA) on the augmentation of heat storage in a hot environment simulating a typical summer day in the southeastern United States (wet bulb globe temperature [WBGT] = 30°C) and noted a significant difference between macro- and micro-WBGTs. The purpose of this study was to characterize the microclimate (micro-WBGT) under a concealed Level II SBA during 60 min of moderately intense work at two separate macro-WBGTs (26°C and 30°C), and to establish WBGT corrections to allow prediction of heat strain in an individual wearing a concealed Level II SBA. A single trial was performed with nine volunteers (27 ± 4 years) outfitted with a simulated standard law enforcement uniform and a traditional concealed Level II SBA, in a moderately warm environment (WBGT = 26°C). Each participant performed cycles of 12 min of walking (1.25 L · min(-1)) and 3 min of arm curls (14.3 kg, 0.6 L · min(-1)) with a 5 min rest after every other cycle, for a total of 60 minutes. This trial was compared to an identical previously completed 60-min work bout at 30°C. A two-way repeated measures ANOVA with Post hoc Bonferroni and paired samples t-test analysis was conducted. A greater difference between macro- micro-WBGTs existed at 26°C compared to the 30°C macro-WBGT. Under these conditions, a moderate work in Level II SBA requires a WBGT correction of 8.9°C and 6.2°C at macro-WBGTs of 26°C and 30°C, respectively. A modified simple linear regression prediction model was established for mean Micro-WBGT for each macro-WBGTs after the plateau point at the 30 min mark. The derivation regressions at 26°C (R(2) = 0.99), and 30°C (R(2) = 0.99) indicate that micro-WBGT could be predicted for each 15 minutes time at both macro-WBGTs tested for individuals doing moderate intensity (300 Kcals · hr(-1)) work wearing concealed Level II SBA.

  15. Assessing law enforcement performance in behavior-based threat detection tasks involving a concealed weapon or device.

    PubMed

    Sweet, Dawn M; Meissner, Christian A; Atkinson, Dominick J

    2017-10-01

    Across 3 experiments, we assessed the ability of law enforcement officers and naïve controls to detect the concealment of a weapon or device. Study 1 used a classic signal detection paradigm in which participants were asked to assess whether a target was concealing a neutered 9-mm handgun. Study 2 involved a compound signal detection paradigm in which participants assessed whether or not 1 of several individuals was concealing an unstable device in their backpack. Study 3 moved to a 2-alternative forced choice paradigm in which participants evaluated which of 2 targets was concealing an unstable device in his backpack. Across all 3 experiments we consistently found no significant differences in detection performance between law enforcement and naïve controls, although participants did perform above chance levels when response bias was free to vary. Furthermore, officers' years of experience was associated with a bias toward perceiving concealment. Given the frequency with which officers are asked to assess the concealment of weapons or devices, and therein to identify threats, our findings suggest the need for additional research to explore various factors (e.g., context, race of target, operational experience, etc.) likely related to performance on such tasks. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Spatial agraphia.

    PubMed

    Ardila, A; Rosselli, M

    1993-07-01

    Twenty-one patients with right hemisphere damage were studied (11 men, 10 women; average age = 41.33; age range 19-65). Subjects were divided into two groups: pre-Rolandic (6) and retro-Rolandic (15) right hemisphere damaged patients. A special writing test was given to each patient. The writing errors observed included literal substitutions, feature omissions and additions, letter omissions and additions, inability to maintain horizontal writing, inappropriate grouping and fragmentation of elements, and changes in handwriting style. Associated disorders included left-hemiparesis, visual field defects, spatial hemi-neglect, constructional apraxia, spatial alexia, and spatial acalculia. It is proposed that spatial agraphia is related to: (1) left hemi-neglect, (2) constructional deficits, (3) general spatial defects, and (4) some motor disautomatization and tendency to perseverate. In cases of right frontal damage, motor-associated deficits (iterations of features and letters) predominated, whereas in cases of posterior right hemisphere damage, spatial defects (inappropriate distribution of written material in the space, grouping of letters belonging to different words, and splitting of words) were more evident. Writing impairments are in general more noticeable in cases of retro-Rolandic damage.

  17. Error estimates of numerical solutions for a cyclic plasticity problem

    NASA Astrophysics Data System (ADS)

    Han, W.

    A cyclic plasticity problem is numerically analyzed in [13], where a sub-optimal order error estimate is shown for a spatially discrete scheme. In this note, we prove an optimal order error estimate for the spatially discrete scheme under the same solution regularity condition. We also derive an error estimate for a fully discrete scheme for solving the plasticity problem.

  18. Space Saving Statistics: An Introduction to Constant Error, Variable Error, and Absolute Error.

    ERIC Educational Resources Information Center

    Guth, David

    1990-01-01

    Article discusses research on orientation and mobility (O&M) for individuals with visual impairments, examining constant, variable, and absolute error (descriptive statistics that quantify fundamentally different characteristics of distributions of spatially directed behavior). It illustrates the statistics with examples, noting their…

  19. Ultra-wide-band 3D microwave imaging scanner for the detection of concealed weapons

    NASA Astrophysics Data System (ADS)

    Rezgui, Nacer-Ddine; Andrews, David A.; Bowring, Nicholas J.

    2015-10-01

    The threat of concealed weapons, explosives and contraband in footwear, bags and suitcases has led to the development of new devices, which can be deployed for security screening. To address known deficiencies of metal detectors and x-rays, an UWB 3D microwave imaging scanning apparatus using FMCW stepped frequency working in the K and Q bands and with a planar scanning geometry based on an x y stage, has been developed to screen suspicious luggage and footwear. To obtain microwave images of the concealed weapons, the targets are placed above the platform and the single transceiver horn antenna attached to the x y stage is moved mechanically to perform a raster scan to create a 2D synthetic aperture array. The S11 reflection signal of the transmitted sweep frequency from the target is acquired by a VNA in synchronism with each position step. To enhance and filter from clutter and noise the raw data and to obtain the 2D and 3D microwave images of the concealed weapons or explosives, data processing techniques are applied to the acquired signals. These techniques include background subtraction, Inverse Fast Fourier Transform (IFFT), thresholding, filtering by gating and windowing and deconvolving with the transfer function of the system using a reference target. To focus the 3D reconstructed microwave image of the target in range and across the x y aperture without using focusing elements, 3D Synthetic Aperture Radar (SAR) techniques are applied to the post-processed data. The K and Q bands, between 15 to 40 GHz, show good transmission through clothing and dielectric materials found in luggage and footwear. A description of the system, algorithms and some results with replica guns and a comparison of microwave images obtained by IFFT, 2D and 3D SAR techniques are presented.

  20. Experimental methods of indoor millimeter-wave radiometric imaging for personnel concealed contraband detection

    NASA Astrophysics Data System (ADS)

    Hu, Taiyang; Xiao, Zelong; Li, Hao; Lv, Rongchuan; Lu, Xuan

    2014-11-01

    The increasingly emerging terrorism attacks and violence crimes around the world have posed severe threats to public security, so carrying out relevant research on advanced experimental methods of personnel concealed contraband detection is crucial and meaningful. All of the advantages of imaging covertly, avoidance of interference with other systems, intrinsic property of being safe to persons under screening , and the superior ability of imaging through natural or manmade obscurants, have significantly combined to enable millimeter-wave (MMW) radiometric imaging to offer great potential in personnel concealed contraband detection. Based upon the current research status of MMW radiometric imaging and urgent demands of personnel security screening, this paper mainly focuses on the experimental methods of indoor MMW radiometric imaging. The reverse radiation noise resulting from super-heterodyne receivers seriously affects the image experiments carried out at short range, so both the generation mechanism and reducing methods of this noise are investigated. Then, the benefit of sky illumination no longer exists for the indoor radiometric imaging, and this leads to the decrease in radiometric temperature contrast between target and background. In order to enhance the radiometric temperature contrast for improving indoor imaging performance, the noise illumination technique is adopted in the indoor imaging scenario. In addition, the speed and accuracy of concealed contraband detection from acquired MMW radiometric images are usually restricted to the deficiencies in traditional artificial interpretation by security inspectors, thus an automatic recognition and location algorithm by integrating improved Fuzzy C-means clustering with moment invariants is put forward. A series of original results are also presented to demonstrate the significance and validity of these methods.

  1. Electromagnetic induction imaging of concealed metallic objects by means of resonating circuits

    NASA Astrophysics Data System (ADS)

    Guilizzoni, R.; Watson, J. C.; Bartlett, P. A.; Renzoni, F.

    2016-05-01

    An electromagnetic induction system, suitable for 2D imaging of metallic samples of different electrical conductivities, has been developed. The system is based on a parallel LCR circuit comprising a ferrite-cored coil (7.8 mm x 9.5 mm, L=680 μH at 1 KHz), a variable resistor and capacitor. The working principle of the system is based on eddy current induction inside a metallic sample when this is introduced into the AC magnetic field created by the coil. The inductance of the LCR circuit is modified due to the presence of the sample, to an extent that depends on its conductivity. Such modification is known to increase when the system is operated at its resonant frequency. Characterizing different metals based on their values of conductivity is therefore possible by utilizing a suitable system operated at resonance. Both imaging and material characterization were demonstrated by means of the proposed electromagnetic induction technique. Furthermore, the choice of using a system with an adjustable resonant frequency made it possible to select resonances that allow magnetic-field penetration through conductive screens. Investigations on the possibility of imaging concealed metals by penetrating such shields have been carried out. A penetration depth of δ~3 mm through aluminium (Al) was achieved. This allowed concealed metallic samples- having conductivities ranging from 0.54 to 59.77 MSm-1 and hidden behind 1.5-mm-thick Al shields- to be imaged. Our results demonstrate that the presence of the concealed metallic objects can be revealed. The technique was thus shown to be a promising detection tool for security applications.

  2. Exploiting synthetic aperture radar imagery for retrieving vibration signatures of concealed machinery

    NASA Astrophysics Data System (ADS)

    Pérez, Francisco; Campbell, Justin B.; Jaramillo, Monica; Dunkel, Ralf; Atwood, Thomas; Doerry, Armin; Gerstle, Walter H.; Santhanam, Balu; Hayat, Majeed M.

    2016-05-01

    It has been demonstrated that the instantaneous acceleration associated with vibrating objects that are directly imaged by synthetic aperture radar (SAR) can be estimated through the application of the discrete fractional Fourier transform (DFrFT) using the information contained in the complex SAR image. In general, vibration signatures may include, for example, the number of chirped sinusoids as well as their respective base frequencies and chirp rates. By further processing the DFrFT-processed data for clutter-noise rejection by means of pseudo- subspace methods, has been shown that the SAR-vibrometry method can be reliable as long as the signal-to-noise ratio (SNR) and the signal-to-clutter ratio (SCR) of the slow-time SAR signal at the range-line of interest exceeds 15dB. Meanwhile, the Nyquist theorem dictates that the maximum measurable vibration frequency is limited by half of the pulse-repetition frequency. This paper focuses on the detection and estimation of vibrations generated by machinery concealed within buildings and other structures. This is a challenging task in general because the vibration signatures of the source are typically altered by their housing structure; moreover, the SNR at the surface of the housing structure tends to be reduced. Here, experimental results for three different vibrating targets, including one concealed target, are reported using complex SAR images acquired by the General Atomics Lynx radar at resolutions of 1-ft and 4-in. The concealed vibrating target is actuated by a gear motor with an off-balance weight attached to it, which is enclosed by a wooden housing. The vibrations of the motor are transmitted to a chimney that extends above the housing structure. Using the SAR vibrometry approach, it is shown that it is possible to distinguish among the three vibrating objects based upon their vibration signatures.

  3. TDCS Guided using fMRI Significantly Accelerates Learning to Identify Concealed Objects

    PubMed Central

    Clark, Vincent P.; Coffman, Brian A.; Mayer, Andy R.; Weisend, Michael P.; Lane, Terran D.R.; Calhoun, Vince D.; Raybourn, Elaine M.; Garcia, Christopher M.; Wassermann, Eric M.

    2011-01-01

    The accurate identification of obscured and concealed objects in complex environments was an important skill required for survival during human evolution, and is required today for many forms of expertise. Here we used transcranial direct current stimulation (tDCS) guided using neuroimaging to increase learning rate in a novel, minimally guided discovery-learning paradigm. Ninety-six subjects identified threat-related objects concealed in naturalistic virtual surroundings used in real-world training. A variety of brain networks were found using fMRI data collected at different stages of learning, with two of these networks focused in right inferior frontal and right parietal cortex. Anodal 2.0 mA tDCS performed for 30 minutes over these regions in a series of single-blind, randomized studies resulted in significant improvements in learning and performance compared with 0.1 mA tDCS. This difference in performance increased to a factor of two after a one-hour delay. A dose-response effect of current strength on learning was also found. Taken together, these brain imaging and stimulation studies suggest that right frontal and parietal cortex are involved in learning to identify concealed objects in naturalistic surroundings. Furthermore, they suggest that the application of anodal tDCS over these regions can greatly increase learning, resulting in one of the largest effects on learning yet reported. The methods developed here may be useful to decrease the time required to attain expertise in a variety of settings. PMID:21094258

  4. Shaeer’s Technique: A Minimally Invasive Procedure for Monsplasty and Revealing the Concealed Penis

    PubMed Central

    2016-01-01

    Background: A concealed penis is a condition where part of the penis is invisible below the surface of the prepubic skin. Dermolipectomy can correct this condition, although it involves a long abdominal crease incision, or infrapubic incision around the base of the penis, and a possibility for genital lymphedema. This study describes Shaeer’s technique, a minimally invasive method for revealing the concealed penis. Methods: A 1- to 2-cm-long incision was cut over the anterior superior iliac spine (ASIS) on either side. A long curved blunt forceps was inserted from one incision, down to the base of the penis and then up to the contralateral ASIS. A 5-mm wide nonabsorbable tape was picked up by the forceps from 1 incision and pulled through to emerge from the other. Pulling on the tape cephalad pulled the mons pubis and revealed the penis. The tape was sutured to the periosteum overlying the ASIS on either side. Patients were followed up for 18 months for penile length, complications, and overall satisfaction. Results: Twenty patients were operated upon. Preoperatively, flaccid visible length was 3 ± 0.9 cm, and erect visible length was 8 ± 4.6 cm. Postoperatively, the flaccid visible length was 7.1 ± 2.1 cm, with a 57.9% improvement in length (P < 0.0001). Erect visible length was 11.8 ± 2.1 cm, with a 32% improvement in length (P < 0.0001). Length gain was maintained for 18 months. Conclusion: Shaeer’s technique is a minimally invasive, short, and simple procedure for monsplasty and revealing the concealed penis. PMID:27622092

  5. Face and Voice as Social Stimuli Enhance Differential Physiological Responding in a Concealed Information Test

    PubMed Central

    Ambach, Wolfgang; Assmann, Birthe; Krieg, Bennet; Vaitl, Dieter

    2012-01-01

    Attentional, intentional, and motivational factors are known to influence the physiological responses in a Concealed Information Test (CIT). Although concealing information is essentially a social action closely related to motivation, CIT studies typically rely on testing participants in an environment lacking of social stimuli: subjects interact with a computer while sitting alone in an experimental room. To address this gap, we examined the influence of social stimuli on the physiological responses in a CIT. Seventy-one participants underwent a mock-crime experiment with a modified CIT. In a between-subjects design, subjects were either questioned acoustically by a pre-recorded male voice presented together with a virtual male experimenter’s uniform face or by a text field on the screen, which displayed the question devoid of face and voice. Electrodermal activity (EDA), respiration line length (RLL), phasic heart rate (pHR), and finger pulse waveform length (FPWL) were registered. The Psychopathic Personality Inventory – Revised (PPI-R) was administered in addition. The differential responses of RLL, pHR, and FPWL to probe vs. irrelevant items were greater in the condition with social stimuli than in the text condition; interestingly, the differential responses of EDA did not differ between conditions. No modulatory influence of the PPI-R sum or subscale scores was found. The results emphasize the relevance of social aspects in the process of concealing information and in its detection. Attentional demands as well as the participants’ motivation to avoid detection might be the important links between social stimuli and physiological responses in the CIT. PMID:23293613

  6. Fuzzy Logic Based Sensor Fusion for Mine and Concealed Weapon Detection

    DTIC Science & Technology

    2003-05-13

    types are ; see Appendix 1 for the code. Fig. II: Output of mine detection program Fig. 12: visual imagen Fig. 13: passive mmwave 11 Fig. 14: FLA...fused Fig. ’s 12 and 13 show the image of a concealed weapon with visual band and passive millimeter-wave (mmwave). ll Passive millimeter-wave forms an...over the images to see if there was a correlation of the visual quality of the fused imagery with the metrics. The entropy of an image is a measure

  7. Standoff concealed weapon detection using a 350 GHz radar imaging system

    SciTech Connect

    Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.; McMakin, Douglas L.; Hatchell, Brian K.; Valdez, Patrick LJ

    2010-04-01

    The Pacific Northwest National Laboratory is currently developing a 350 GHz, active, wideband, three-dimensional, radar imaging system to evaluate the feasibility of active sub-mm imaging for standoff concealed weapon detection. The prototype radar imaging system is based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed rotating conical scanner. The wideband operation of this system provides accurate ranging information, and the images obtained are fully three-dimensional. Recent improvements to the system include increased imaging speed using improved balancing techniques, wider bandwidth, and image display techniques.

  8. [Effects of arousal level on the physiological responding on the Concealed Information Test].

    PubMed

    Ogawa, Tokihiro; Tsuruga, Mariko; Kobayashi, Takahiro; Matsuda, Izumi; Hirota, Akihisa; Suzuki, Naoto

    2007-10-01

    This study examined effects of arousal level on the physiological responses in a polygraph examination using the Concealed Information Test (CIT). Thirty-nine healthy college students were tested with or without evaluative observation. Electrodermal activity, blood pressure, heart rate, normalized pulse volume, and respiration were recorded. Observation elevated participants' arousal level, which was manifested in self-reports, high skin conductance level, and low normalized pulse volume (i.e., vasoconstriction). However, differential reactivity to critical and non-critical items on the physiological measures was less affected by observation. These results suggested that participants' arousal level has little effect on differential physiological reactivity on the CIT.

  9. Millimetre wave and terahertz technology for the detection of concealed threats: a review

    NASA Astrophysics Data System (ADS)

    Kemp, Michael C.

    2006-09-01

    There has been intense interest in the use of millimetre wave and terahertz technology for the detection of concealed weapons, explosives and other threats. Electromagnetic waves at these frequencies are safe, penetrate barriers and have short enough wavelengths to allow discrimination between objects. In addition, many solids including explosives have characteristic spectroscopic signatures at terahertz wavelengths which can be used to identify them. This paper reviews the progress which has been made in recent years and identifies the achievements, challenges and prospects for these technologies in checkpoint people screening, stand off detection of improvised explosive devices (IEDs) and suicide bombers as well as more specialized screening tasks.

  10. Evaluation of coping strategies in established rheumatoid arthritis patients: emergence of concealment in an Asian cohort.

    PubMed

    Chew, Elizabeth; Griva, Konstadina; Cheung, Peter P

    2016-11-01

    To evaluate coping strategies of Asian RA patients and their associations with health-related quality of life (HRQoL). A cross-sectional sample of patients with established RA was evaluated using measures of coping (Coping in Rheumatoid Arthritis Questionnaire [C-RAQ]; appraisal of coping effectiveness and helplessness), HRQoL (Mental and Physical Components [MCS/PCS] of the Short Form 12v2; Rheumatoid Arthritis Impact of Disease score [RAID]) and clinical/laboratory assessments. Principal component analysis was conducted to identify coping strategies. Multiple linear regression analyses were performed to evaluate the associations between coping strategies and HRQoL outcomes. The study sample comprised 101 patients, 81% female, 72.3% Chinese, mean age 54.2 ± 12.6 years. Five coping strategies were identified: Active problem solving (E = 5.36), Distancing (E = 2.30), Concealment (E = 1.89), Cognitive reframing (E = 1.55) and Emotional expression (E = 1.26). Concealment was consistently associated with PCS (rs = -0.23, P = 0.049), MCS (rs = -0.24, P = 0.04) and RAID (rs = 0.39, P < 0.001), and was significant in the multivariate model to explain lower disease-specific HRQoL (RAID) even after adjusting for disease activity, coping effectiveness and helplessness (β = 0.20, P = 0.04). Emotional expression was associated with poorer physical HRQoL (PCS), after adjusting for disease severity, body mass index, coping effectiveness, helplessness and Concealment (β = -0.39, P < 0.001). Perceived coping-related helplessness was significant in multivariate correlates for PCS (β = -0.25, P = 0.036), MCS (β = -0.29, P = 0.02) and RAID (β = 0.53, P < 0.001), after adjusting for covariates. Concealment and Emotional expression are associated with lower disease-specific HRQoL and physical HRQoL respectively, with the former coping strategy likely to be culture-specific. Interventions should tailor psychosocial support needs to address not only coping strategies, but patients

  11. Multispectral illumination and image processing techniques for active millimeter-wave concealed object detection.

    PubMed

    Zhang, Lixiao; Stiens, Johan; Elhawil, Amna; Vounckx, Roger

    2008-12-01

    Active millimeter-wave imaging systems for concealed object detection offer the possibility of much higher image contrast than passive systems, especially in indoor applications. By studying active millimeter-wave images of different test objects derived in the W band, we show that multispectral illumination is critical to the detectability of targets. We also propose to use image change detection techniques, including image differencing, normalized difference vegetation index, and principle component analysis to process the multispectral millimeter-wave images. The results demonstrate that multispectral illumination can significantly reveal the object features hidden by image artifacts and improve the appearance of the objects.

  12. Ambient air cooling for concealed soft body armor in a hot environment.

    PubMed

    Ryan, Greg A; Bishop, Stacy H; Herron, Robert L; Katica, Charles P; Elbon, Bre'anna L; Bosak, Andrew M; Bishop, Phillip

    2014-01-01

    Concealed soft body armor inhibits convective and evaporative heat loss and increases heat storage, especially in hot environments. One option to potentially mitigate heat storage is to promote airflow under the soft body armor. The purpose of this study was to evaluate the effect of ambient air induction (∼100 liters per minute) on heat strain while wearing concealed soft body armor in a hot environment (wet bulb globe temperature = 30°C). A counter-balanced, repeated measures protocol was performed with nine healthy male volunteers. Participants were fitted with either a traditional or modified Level II concealed soft body armor. Participants performed cycles of 12 min of walking (1.25 liters per minute) and 3 min of arm curls (0.6 liters per minute) for a total of 60 min. Two-way repeated measures ANOVA was used to assess the mean differences in physiological measures (rectal temperature, heart rate, micro-environment [temperature and relative humidity]). Post hoc Bonferroni analysis and paired samples t-tests (alpha = 0.01) were conducted on omnibus significant findings. Perceptual measures (perceived exertion, thermal comfort) were analyzed using Wilcoxon Signed Ranks Tests. Modification led to an improvement in perceived exertion at 45 min (MOD: 10 ± 1; CON: 11 ± 2; p ≤ 0.001) and 60 min (MOD: 10 ± 2; CON: 12 ± 2; p ≤ 0.001) and a reduction in micro-environment temperature in MOD (1.0 ± 0.2°C, p = 0.03) compared to CON. Modification did not attenuate change in rectal temperature or heart rate (p < 0.01) during 60-min work bout. Change in rectal temperature approached significance between MOD and CON at the end of the work bout (MOD: 0.4 ± 0.2°C; CON: 0.7 ± 0.3°C; p = 0.048). The slope of rectal temperature was significantly greater (p = 0.04) under CON compared to MOD. These data suggest that air induction may provide small benefits while wearing concealed soft body armor, though improvements are needed to lessen physiological strain.

  13. An algorithm to unveil the inner structure of objects concealed by beam divergence in radiographic image acquisition systems

    SciTech Connect

    Almeida, G. L.; Silvani, M. I.; Lopes, R. T.

    2014-11-11

    Two main parameters rule the performance of an Image Acquisition System, namely, spatial resolution and contrast. For radiographic systems using cone beam arrangements, the farther the source, the better the resolution, but the contrast would diminish due to the lower statistics. A closer source would yield a higher contrast but it would no longer reproduce the attenuation map of the object, as the incoming beam flux would be reduced by unequal large divergences and attenuation factors. This work proposes a procedure to correct these effects when the object is comprised of a hull - or encased in it - possessing a shape capable to be described in analytical geometry terms. Such a description allows the construction of a matrix containing the attenuation factors undergone by the beam from the source until its final destination at each coordinate on the 2D detector. Each matrix element incorporates the attenuation suffered by the beam after its travel through the hull wall, as well as its reduction due to the square of distance to the source and the angle it hits the detector surface. When the pixel intensities of the original image are corrected by these factors, the image contrast, reduced by the overall attenuation in the exposure phase, are recovered, allowing one to see details otherwise concealed due to the low contrast. In order to verify the soundness of this approach, synthetic images of objects of different shapes, such as plates and tubes, incorporating defects and statistical fluctuation, have been generated, recorded for further comparison and afterwards processed to improve their contrast. The developed algorithm which, generates processes and plots the images has been written in Fortran 90 language. As the resulting final images exhibit the expected improvements, it therefore seemed worthwhile to carry out further tests with actual experimental radiographies.

  14. Geometrical configurations of unphased diffraction-limited antennas in passive millimetre-wave imaging systems for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Serenelli, Roberto

    2004-12-01

    This paper analyzes simple imaging configurations to scan a human body, suitable as passive or active millimetre-wave imaging systems for concealed weapon detection (CWD). The first cylindrical configuration allows a 360 degrees scan: N unphased diffraction-limited antennas each of size L are placed on a circular support surrounding the subject (allowing scanning in the horizontal plane with N non-overlapping independent beams), and this circle is mechanically displaced over the whole body height. An analytical formula gives the maximum obtainable spatial resolution for different dimensions of the circular scanning device and operating frequencies, and the number of receivers achieving this optimal resolution. Constraints to be taken into account are diffraction, the usable total length of the circle, and the full coverage by the N beams over the subject, which is modelled as a cylinder with variable radius, coaxial with the scanning circle. Numerical calculations of system resolution are shown for different operating microwave (MW) and millimetre-wave (MMW) frequencies; in order to study off-axis performances, situations where the subject is not coaxial with the scanning device are also considered. For the case of a parallelepiped to be imaged instead of a cylinder, a linear array configuration is analyzed similarly to the circular one. A theoretical study is carried out to design other curved arrays, filled with unphased diffraction-limited antennas, for the imaging of linear subjects with finer resolution. Finally, the application of such configurations is considered for the design of active imaging systems, and different system architectures are discussed.

  15. An algorithm to unveil the inner structure of objects concealed by beam divergence in radiographic image acquisition systems

    NASA Astrophysics Data System (ADS)

    Almeida, G. L.; Silvani, M. I.; Lopes, R. T.

    2014-11-01

    Two main parameters rule the performance of an Image Acquisition System, namely, spatial resolution and contrast. For radiographic systems using cone beam arrangements, the farther the source, the better the resolution, but the contrast would diminish due to the lower statistics. A closer source would yield a higher contrast but it would no longer reproduce the attenuation map of the object, as the incoming beam flux would be reduced by unequal large divergences and attenuation factors. This work proposes a procedure to correct these effects when the object is comprised of a hull - or encased in it - possessing a shape capable to be described in analytical geometry terms. Such a description allows the construction of a matrix containing the attenuation factors undergone by the beam from the source until its final destination at each coordinate on the 2D detector. Each matrix element incorporates the attenuation suffered by the beam after its travel through the hull wall, as well as its reduction due to the square of distance to the source and the angle it hits the detector surface. When the pixel intensities of the original image are corrected by these factors, the image contrast, reduced by the overall attenuation in the exposure phase, are recovered, allowing one to see details otherwise concealed due to the low contrast. In order to verify the soundness of this approach, synthetic images of objects of different shapes, such as plates and tubes, incorporating defects and statistical fluctuation, have been generated, recorded for further comparison and afterwards processed to improve their contrast. The developed algorithm which, generates processes and plots the images has been written in Fortran 90 language. As the resulting final images exhibit the expected improvements, it therefore seemed worthwhile to carry out further tests with actual experimental radiographies.

  16. Parasitism rate, parasitoid community composition and host specificity on exposed and semi-concealed caterpillars from a tropical rainforest.

    PubMed

    Hrcek, Jan; Miller, Scott E; Whitfield, James B; Shima, Hiroshi; Novotny, Vojtech

    2013-10-01

    The processes maintaining the enormous diversity of herbivore-parasitoid food webs depend on parasitism rate and parasitoid host specificity. The two parameters have to be evaluated in concert to make conclusions about the importance of parasitoids as natural enemies and guide biological control. We document parasitism rate and host specificity in a highly diverse caterpillar-parasitoid food web encompassing 266 species of lepidopteran hosts and 172 species of hymenopteran or dipteran parasitoids from a lowland tropical forest in Papua New Guinea. We found that semi-concealed hosts (leaf rollers and leaf tiers) represented 84% of all caterpillars, suffered a higher parasitism rate than exposed caterpillars (12 vs. 5%) and their parasitoids were also more host specific. Semi-concealed hosts may therefore be generally more amenable to biological control by parasitoids than exposed ones. Parasitoid host specificity was highest in Braconidae, lower in Diptera: Tachinidae, and, unexpectedly, the lowest in Ichneumonidae. This result challenges the long-standing view of low host specificity in caterpillar-attacking Tachinidae and suggests higher suitability of Braconidae and lower suitability of Ichneumonidae for biological control of caterpillars. Semi-concealed hosts and their parasitoids are the largest, yet understudied component of caterpillar-parasitoid food webs. However, they still remain much closer in parasitism patterns to exposed hosts than to what literature reports on fully concealed leaf miners. Specifically, semi-concealed hosts keep an equally low share of idiobionts (2%) as exposed caterpillars.

  17. Sun compass error model

    NASA Technical Reports Server (NTRS)

    Blucker, T. J.; Ferry, W. W.

    1971-01-01

    An error model is described for the Apollo 15 sun compass, a contingency navigational device. Field test data are presented along with significant results of the test. The errors reported include a random error resulting from tilt in leveling the sun compass, a random error because of observer sighting inaccuracies, a bias error because of mean tilt in compass leveling, a bias error in the sun compass itself, and a bias error because the device is leveled to the local terrain slope.

  18. Unforced errors and error reduction in tennis

    PubMed Central

    Brody, H

    2006-01-01

    Only at the highest level of tennis is the number of winners comparable to the number of unforced errors. As the average player loses many more points due to unforced errors than due to winners by an opponent, if the rate of unforced errors can be reduced, it should lead to an increase in points won. This article shows how players can improve their game by understanding and applying the laws of physics to reduce the number of unforced errors. PMID:16632568

  19. Unforced errors and error reduction in tennis.

    PubMed

    Brody, H

    2006-05-01

    Only at the highest level of tennis is the number of winners comparable to the number of unforced errors. As the average player loses many more points due to unforced errors than due to winners by an opponent, if the rate of unforced errors can be reduced, it should lead to an increase in points won. This article shows how players can improve their game by understanding and applying the laws of physics to reduce the number of unforced errors.

  20. Specific NIST projects in support of the NIJ Concealed Weapon Detection and Imaging Program

    NASA Astrophysics Data System (ADS)

    Paulter, Nicholas G.

    1998-12-01

    The Electricity Division of the National Institute of Standards and Technology is developing revised performance standards for hand-held (HH) and walk-through (WT) metal weapon detectors, test procedures and systems for these detectors, and a detection/imaging system for finding concealed weapons. The revised standards will replace the existing National Institute of Justice (NIJ) standards for HH and WT devices and will include detection performance specifications as well as system specifications (environmental conditions, mechanical strength and safety, response reproducibility and repeatability, quality assurance, test reporting, etc.). These system requirements were obtained from the Law Enforcement and corrections Technology Advisory Council, an advisory council for the NIJ. Reproducible and repeatable test procedures and appropriate measurement systems will be developed for evaluating HH and WT detection performance. A guide to the technology and application of non- eddy-current-based detection/imaging methods (such as acoustic, passive millimeter-wave and microwave, active millimeter-wave and terahertz-wave, x-ray, etc.) Will be developed. The Electricity Division is also researching the development of a high- frequency/high-speed (300 GH to 1 THz) pulse-illuminated, stand- off, video-rate, concealed weapons/contraband imaging system.

  1. Portable concealed weapon detection using millimeter-wave FMCW radar imaging

    NASA Astrophysics Data System (ADS)

    Johnson, Michael A.; Chang, Yu-Wen

    2001-02-01

    Unobtrusive detection of concealed weapons on persons or in abandoned bags would provide law enforcement a powerful tool to focus resources and increase traffic throughput in high- risk situations. We have developed a fast image scanning 94 GHz radar system that is suitable for portable operation and remote viewing of radar data. This system includes a novel fast image-scanning antenna that allows for the acquisition of medium resolution 3D millimeter wave images of stationary targets with frame times on order of one second. The 3D radar data allows for potential isolation of concealed weapons from body and environmental clutter such as nearby furniture or other people. The radar is an active system so image quality is not affected indoors, emitted power is however very low so there are no health concerns for operator or targets. The low power operation is still sufficient to penetrate heavy clothing or material. Small system size allows for easy transport and rapid deployment of the system as well as an easy migration path to future hand held systems.

  2. Noninvasive detection of concealed explosives: depth profiling through opaque plastics by time-resolved Raman spectroscopy.

    PubMed

    Petterson, Ingeborg E Iping; López-López, María; García-Ruiz, Carmen; Gooijer, Cees; Buijs, Joost B; Ariese, Freek

    2011-11-15

    The detection of explosives concealed behind opaque, diffusely scattering materials is a challenge that requires noninvasive analytical techniques for identification without having to manipulate the package. In this context, this study focuses on the application of time-resolved Raman spectroscopy (TRRS) with a picosecond pulsed laser and an intensified charge-coupled device (ICCD) detector for the noninvasive identification of explosive materials through several millimeters of opaque polymers or plastic packaging materials. By means of a short (250 ps) gate which can be delayed several hundred picoseconds after the laser pulse, the ICCD detector allows for the temporal discrimination between photons from the surface of a sample and those from deeper layers. TRRS was applied for the detection of the two main isomers of dinitrotoluene, 2,4-dinitrotoluene, and 2,6-dinitrotoluene as well as for various other components of explosive mixtures, including akardite II, diphenylamine, and ethyl centralite. Spectra were obtained through different diffuse scattering white polymer materials: polytetrafluoroethylene (PTFE), polyoxymethylene (POM), and polyethylene (PE). Common packaging materials of various thicknesses were also selected, including polystyrene (PS) and polyvinyl chloride (PVC). With the demonstration of the ability to detect concealed, explosives-related compounds through an opaque first layer, this study may have important applications in the security and forensic fields.

  3. Combined illumination cylindrical millimeter-wave imaging technique for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; McMakin, Douglas L.; Hall, Thomas E.

    2000-07-01

    A novel millimeter-wave imaging technique has been developed for personnel surveillance applications, including the detection of concealed weapons, explosives, drugs, and other contraband material. Millimeter-waves are high-frequency radio waves in the frequency band of 30 - 300 GHz, and pose no health threat to humans at moderate power levels. These waves readily penetrate common clothing materials, and are reflected by the human body and by concealed items. The combined illumination cylindrical imaging concept consists of a vertical, high-resolution, millimeter-wave array of antennas which is scanned in a cylindrical manner about the person under surveillance. Using a computer, the data from this scan is mathematically reconstructed into a series of focused 3D images of the person. After reconstruction, the images are combined into a single high-resolution 3D image of the person under surveillance. This combined image is then rendered using 3D computer graphics techniques. The combined cylindrical illumination is critical as it allows the display of information from all angles. This is necessary because millimeter-waves do not penetrate the body. Ultimately, the images displayed to the operate will be icon-based to protect the privacy of the person being screened. Novel aspects of this technique include the cylindrical scanning concept and the image reconstruction algorithm, which was developed specifically for this imaging system. An engineering prototype based on this cylindrical imaging technique has been fabricated and tested. This work has been sponsored by the Federal Aviation Administration.

  4. The etiquette of endometriosis: stigmatisation, menstrual concealment and the diagnostic delay.

    PubMed

    Seear, Kate

    2009-10-01

    Endometriosis is a chronic gynaecological condition of uncertain aetiology characterised by menstrual irregularities. Several studies have previously identified a lengthy delay experienced by patients between the first onset of symptoms and eventual diagnosis. Various explanations have been advanced for the diagnostic delay, with both doctors and women being implicated. Such explanations include that doctors normalise women's menstrual pain and that women might delay in seeking medical advice because they have difficulty distinguishing between 'normal' and 'abnormal' menstruation. It has been suggested that the diagnostic delay could be reduced if women were trained in how to distinguish between 'normal' and 'abnormal' menstrual cycles. In this paper I argue that whilst these may be factors in the diagnostic delay, women's reluctance to disclose problems associated with their menstrual cycle may be a more significant and hitherto neglected factor. I argue women are reluctant to disclose menstrual irregularities because menstruation is a 'discrediting attribute' (Goffman, 1963) and disclosure renders women vulnerable to stigmatisation. Women actively conceal their menstrual irregularities through practices of the 'menstrual etiquette' (Laws, 1990) which involves the strategic concealment of menstrual problems. This argument is supported through an analysis of the experiences of 20 Australian women diagnosed with endometriosis. The ramifications of this analysis for chronic pain conditions more generally and for practical strategies designed to address the endometriosis diagnostic delay are considered.

  5. Detection of hazardous liquids concealed in glass, plastic, and aluminum containers

    NASA Astrophysics Data System (ADS)

    Ramirez, Michael L.; Ortiz, William; Ruiz, Orlando; Pacheco-Londoño, Leonardo; Hernández-Rivera, Samuel P.

    2007-04-01

    The use of liquid explosives by terrorists has raised the attention to the use of hazardous liquids as threats to people, buildings and transportation systems. Hazardous liquids such as explosive mixtures, flammables or even chemical warfare agents (CWA) can be concealed in common containers and pass security checks undetected. This work presents three non invasive, non destructive detection approaches that can be used to characterize the content of common liquid containers and detect if the liquid is the intended or a concealed hazardous liquid. Fiber optic coupled Raman spectroscopy and Stand off Raman spectroscopy were used to inspect the content of glass and plastic bottles and thermal conductivity was used to asses the liquid inside aluminum cans. Raman spectroscopy experiments were performed at 532 nm, 488 nm and 785 nm excitation wavelengths. The hazardous liquids under consideration included CWA simulant DMMP, hydrogen peroxide, acetone, cyclohexane, ethanol and nitric acid. These techniques have potential use as a detector for hazardous liquids at a check point or to inspect suspicious bottles from a distance.

  6. Concealing of facial expressions by a wild Barbary macaque (Macaca sylvanus).

    PubMed

    Thunström, Maria; Kuchenbuch, Paul; Young, Christopher

    2014-07-01

    Behavioural research on non-vocal communication among non-human primates and its possible links to the origin of human language is a long-standing research topic. Because human language is under voluntary control, it is of interest whether this is also true for any communicative signals of other species. It has been argued that the behaviour of hiding a facial expression with one's hand supports the idea that gestures might be under more voluntary control than facial expressions among non-human primates, and it has also been interpreted as a sign of intentionality. So far, the behaviour has only been reported twice, for single gorilla and chimpanzee individuals, both in captivity. Here, we report the first observation of concealing of facial expressions by a monkey, a Barbary macaque (Macaca sylvanus), living in the wild. On eight separate occasions between 2009 and 2011 an adult male was filmed concealing two different facial expressions associated with play and aggression ("play face" and "scream face"), 22 times in total. The videos were analysed in detail, including gaze direction, hand usage, duration, and individuals present. This male was the only individual in his group to manifest this behaviour, which always occurred in the presence of a dominant male. Several possible interpretations of the function of the behaviour are discussed. The observations in this study indicate that the gestural communication and cognitive abilities of monkeys warrant more research attention.

  7. Development of a longer range standoff millimetre wave radar concealed threat detector

    NASA Astrophysics Data System (ADS)

    Bowring, Nicholas J.; Southgate, Matthew J.; Andrews, David A.; Rezgui, Nacer D.; Harmer, Stuart W.; O'Reilly, Dean

    2013-05-01

    A millimeter wave (75 - 110 GHz) polarimetric radar system (MiRTLE) has been developed for the detection of threat objects, such as guns, knives, or explosive devices, which have been concealed under clothing upon the human body. The system uses a Gaussian lens antenna to enable operation at stand-off ranges up to 25 meters. By utilizing ultra-wideband Swept Frequency Continuous Wave Radar very high range resolution (~ 10mm) is realized. The system is capable of detecting objects positioned in front of the body and of measuring the range of a target. By interpretation of the scattered waveform, the presence of a wide spectrum of threat items concealed on the human body may be detected. Threat detection is autonomously rendered by application of a neural network to the scattered time domain, polarimetric radar returns and the system may be taught to alarm or reject certain classes of objects; this allows for highly specific or broad spectrum threat detection. The radar system is portable and operator steerable allowing standoff monitoring of moving human targets in real time. Rapid (1ms) sweep times and fast signal acquisition and processing allow decisions to be made at video frame rates (30 fps) and integrated directly to a video feed providing the operator with a field of view and facilitating aiming. Performance parameters for detection of guns and simulated explosive devices are presented for ranges up to 25 meters.

  8. Are There Limits to Collectivism? Culture and Children's Reasoning About Lying to Conceal a Group Transgression.

    PubMed

    Sweet, Monica A; Heyman, Gail D; Fu, Genyue; Lee, Kang

    2010-07-01

    This study explored the effects of collectivism on lying to conceal a group transgression. Seven-, 9-, and 11-year-old US and Chinese children (N = 374) were asked to evaluate stories in which protagonists either lied or told the truth about their group's transgression and were then asked about either the protagonist's motivations or justification for their own evaluations. Previous research suggests that children in collectivist societies such as China find lying for one's group to be more acceptable than do children from individualistic societies such as the United States. The current study provides evidence that this is not always the case: Chinese children in this study viewed lies told to conceal a group's transgressions less favourably than did US children. An examination of children's reasoning about protagonists' motivations for lying indicated that children in both countries focused on an impact to self when discussing motivations for protagonists to lie for their group. Overall, results suggest that children living in collectivist societies do not always focus on the needs of the group.

  9. Partner choice through concealed floral sugar rewards evolved with the specialization of ant-plant mutualisms.

    PubMed

    Chomicki, Guillaume; Staedler, Yannick M; Schönenberger, Jürg; Renner, Susanne S

    2016-09-01

    Obligate mutualisms require filtering mechanisms to prevent their exploitation by opportunists, but ecological contexts and traits facilitating the evolution of such mechanisms are largely unknown. We investigated the evolution of filtering mechanisms in an epiphytic ant-plant symbiotic system in Fiji involving Rubiaceae and dolichoderine ants, using field experiments, metabolomics, X-ray micro-computed tomography (micro-CT) scanning and phylogenetics. We discovered a novel plant reward consisting of sugary sap concealed in post-anthetic flowers only accessible to Philidris nagasau workers that bite through the thick epidermis. In five of the six species of Rubiaceae obligately inhabited by this ant, the nectar glands functioned for 10 d after a flower's sexual function was over. Sugar metabolomics and field experiments showed that ant foraging tracks sucrose levels, which only drop at the onset of fruit development. Ontogenetic analyses of our focal species and their relatives revealed a 25-fold increase in nectary size and delayed fruit development in the ant-rewarding species, and Bayesian analyses of several traits showed the correlated evolution of sugar rewards and symbiosis specialization. Concealed floral nectar forestalls exploitation by opportunists (generalist ants) and stabilizes these obligate mutualisms. Our study pinpoints the importance of partner choice mechanisms in transitions from facultative to obligate mutualisms. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  10. Survey of state-of-the-art technology in remote concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Currie, Nicholas C.; Demma, Fred J.; Ferris, David D., Jr.; McMillan, Robert W.; Vannicola, Vincent C.; Wicks, Michael C.

    1995-09-01

    Recent advances in millimeter-wave (MMV), microwave, and infrared (IR) technologies provide the means to detect concealed weapons remotely through clothing and is some cases through walls. Since the developemnt of forward-looking infrared instruments, work has been ongoing in attempting to use these devices for concealed weapon detection based on temperatrue differences between metallic weapons and in the infrared has led to the development of techniques based on lower frequencies. Focal plane arrays operating MMW frequencies are becoming available which eliminate the need for a costly and slow mechanical scanner for generating images. These radiometric sensors also detect temperature differences between weapons and the human body background. Holographic imaging systems operating at both microwave and MMW frequencies have been developed which generate images of near photographic quality through clothing and through thin, nonmetallic walls. Finally, a real- aperture radar is useful for observing people and detecting weapons through walls and in the field under reduced visibility conditions. This paper will review all of these technologies and give examples of images generated by each type of sensor. An assessment of the future of this technology with regard to law enforcement applications will also be given.

  11. Combining Blink, Pupil, and Response Time Measures in a Concealed Knowledge Test

    PubMed Central

    Seymour, Travis L.; Baker, Christopher A.; Gaunt, Joshua T.

    2013-01-01

    The response time (RT) based Concealed Knowledge Test (CKT) has been shown to accurately detect participants’ knowledge of mock-crime-related information. Tests based on ocular measures such as pupil-size and blink-rate have sometimes resulted in poor classification, or lacked detailed classification analyses. The present study examines the fitness of multiple pupil and blink related responses in the CKT paradigm. To maximize classification efficiency, participants’ concealed knowledge was assessed using both individual test measures and combinations of test measures. Results show that individual pupil-size, pupil-slope, and pre-response blink-rate measures produce efficient classifications. Combining pupil and blink measures yielded more accuracy classifications than individual ocular measures. Although RT-based tests proved efficient, combining RT with ocular measures had little incremental benefit. It is argued that covertly assessing ocular measures during RT-based tests may guard against effective countermeasure use in applied settings. A compound classification procedure was used to categorize individual participants and yielded high hit rates and low false-alarm rates without the need for adjustments between test paradigms and subject populations. We conclude that with appropriate test paradigms and classification analyses, ocular measures may prove as effective as other indices, though additional research is needed. PMID:23382718

  12. Exposed and concealed antigens as vaccine targets for controlling ticks and tick-borne diseases.

    PubMed

    Nuttall, P A; Trimnell, A R; Kazimirova, M; Labuda, M

    2006-04-01

    Tick vaccines derived from Bm86, a midgut membrane-bound protein of the cattle tick, Boophilus microplus, are currently the only commercially available ectoparasite vaccines. Despite its introduction to the market in 1994, and the recognized need for alternatives to chemical pesticides, progress in developing effective antitick vaccines (and ectoparasite vaccines in general) is slow. The primary rate-limiting step is the identification of suitable antigenic targets for vaccine development. Two sources of candidate vaccine antigens have been identified: 'exposed' antigens that are secreted in tick saliva during attachment and feeding on a host and 'concealed' antigens that are normally hidden from the host. Recently, a third group of antigens has been distinguished that combines the properties of both exposed and concealed antigens. This latter group offers the prospect of a broad-spectrum vaccine effective against both adults and immature stages of a wide variety of tick species. It also shows transmission-blocking and protective activity against a tick-borne pathogen. With the proliferation of molecular techniques and their application to vaccine development, there are high hopes for new and effective antitick vaccines that also control tick-borne diseases.

  13. Ultra wide band millimeter wave holographic ``3-D`` imaging of concealed targets on mannequins

    SciTech Connect

    Collins, H.D.; Hall, T.E.; Gribble, R.P.

    1994-08-01

    Ultra wide band (chirp frequency) millimeter wave ``3-D`` holography is a unique technique for imaging concealed targets on human subjects with extremely high lateral and depth resolution. Recent ``3-D`` holographic images of full size mannequins with concealed weapons illustrate the efficacy of this technique for airport security. A chirp frequency (24 GHz to 40 GHz) holographic system was used to construct extremely high resolution images (optical quality) using polyrod antenna in a bi-static configuration using an x-y scanner. Millimeter wave chirp frequency holography can be simply described as a multi-frequency detection and imaging technique where the target`s reflected signals are decomposed into discrete frequency holograms and reconstructed into a single composite ``3-D`` image. The implementation of this technology for security at airports, government installations, etc., will require real-time (video rate) data acquisition and computer image reconstruction of large volumetric data sets. This implies rapid scanning techniques or large, complex ``2-D`` arrays and high speed computing for successful commercialization of this technology.

  14. Remote laser drilling and sampling system for the detection of concealed explosives

    NASA Astrophysics Data System (ADS)

    Wild, D.; Pschyklenk, L.; Theiß, C.; Holl, G.

    2017-05-01

    The detection of hazardous materials like explosives is a central issue in national security in the field of counterterrorism. One major task includes the development of new methods and sensor systems for the detection. Many existing remote or standoff methods like infrared or raman spectroscopy find their limits, if the hazardous material is concealed in an object. Imaging technologies using x-ray or terahertz radiation usually yield no information about the chemical content itself. However, the exact knowledge of the real threat potential of a suspicious object is crucial for disarming the device. A new approach deals with a laser drilling and sampling system for the use as verification detector for suspicious objects. Central part of the system is a miniaturised, diode pumped Nd:YAG laser oscillator-amplifier. The system allows drilling into most materials like metals, synthetics or textiles with bore hole diameters in the micron scale. During the drilling process, the hazardous material can be sampled for further investigation with suitable detection methods. In the reported work, laser induced breakdown spectroscopy (LIBS) is used to monitor the drilling process and to classify the drilled material. Also experiments were carried out to show the system's ability to not ignite even sensitive explosives like triacetone triperoxide (TATP). The detection of concealed hazardous material is shown for different explosives using liquid chromatography and ion mobility spectrometry.

  15. A survey of studies into errors in large scale space-time averages of rainfall, cloud cover, sea surface processes and the earth's radiation budget as derived from low earth orbit satellite instruments because of their incomplete temporal and spatial coverage

    NASA Astrophysics Data System (ADS)

    Astin, Ivan

    This survey considers those studies conducted into estimating errors in satellite derived large scale space-time means (of the order of 250 km by 250 km by a month) for rainfall, cloud cover, sea surface processes and the Earth''s radiation budget, resulting from their incomplete coverage of the space-time volume over which the mean is evaluated. Many of these studies have focused on estimating the errors in space-time means post satellite launch and compare mean data derived from such satellites with that from an independent data set. Pre-launch studies tend to involve computer simulations of a satellite overflying and sampling from an existing data set and hence the two approaches give values for sampling errors for specific cases. However, more generic sampling papers exist that allow the exact evaluation of sampling errors for any instrument or combination of instruments if their sampling characteristics and the auto-correlation of the parameter field are known. These generic and simulation techniques have been used together on the same data sets and are found to give very similar values for the sampling error and are presented. Also considered are studies in which data from several satellites, or satellite and ground based measurements are combined to improve estimates in the above means. This improvement being brought about not only by increased spatial and temporal coverage but also by a reduction in retrieval error.

  16. Diagonal spatial neglect

    PubMed Central

    Mark, V.; Heilman, K.

    1998-01-01

    OBJECTIVE—To determine whether stroke patients with diagonal neglect on cancellation may show diagonal neglect on line bisection, and hence to indicate whether diagonal neglect may be related solely to the type of test used or whether instead it may reflect a fundamental spatial disorder.
METHODS—Nine patients with subacute right hemispheric stroke who neglected targets primarily in the near left direction on line cancellation bisected diagonal lines of two opposing orientations: near left to far right and far left to near right. The errors were assessed to determine whether line orientation significantly affected bisection error.
RESULTS—Eight patients had significant bisection errors. One of these showed no effect of line orientation on error, consistent with lateral neglect. The remaining seven patients had a line orientation effect, indicating a net diagonal spatial bias. For the group, cancellation errors were significantly correlated with the line orientation effect on bisection errors.
CONCLUSIONS—A significant diagonal bias on two tests of spatial attention may appear in stroke patients, although the directions of the biases may differ within individual patients. None the less, diagonal neglect may be a fundamental spatial attentional disturbance of right hemispheric stroke. Greater severity of stroke deficit as indicated by cancellation error score may be associated with a greater degree of diagonal neglect on line bisection.

 PMID:9728947

  17. Decision makers use norms, not cost-benefit analysis, when choosing to conceal or reveal unfair rewards.

    PubMed

    Heimann, Marco; Girotto, Vittorio; Legrenzi, Paolo; Bonnefon, Jean-François

    2013-01-01

    We introduce the Conceal or Reveal Dilemma, in which individuals receive unfair benefits, and must decide whether to conceal or to reveal this unfair advantage. This dilemma has two important characteristics: it does not lend itself easily to cost-benefit analysis, neither to the application of any strong universal norm. As a consequence, it is ideally suited to the study of interindividual and intercultural variations in moral-economic norms. In this paper we focus on interindividual variations, and we report four studies showing that individuals cannot be swayed by financial incentives to conceal or to reveal, and follow instead fixed, idiosyncratic strategies. We discuss how this result can be extended to individual and cultural variations in the tendency to display or to hide unfair rewards.

  18. Decision Makers Use Norms, Not Cost-Benefit Analysis, When Choosing to Conceal or Reveal Unfair Rewards

    PubMed Central

    Heimann, Marco; Girotto, Vittorio; Legrenzi, Paolo; Bonnefon, Jean-François

    2013-01-01

    We introduce the Conceal or Reveal Dilemma, in which individuals receive unfair benefits, and must decide whether to conceal or to reveal this unfair advantage. This dilemma has two important characteristics: it does not lend itself easily to cost-benefit analysis, neither to the application of any strong universal norm. As a consequence, it is ideally suited to the study of interindividual and intercultural variations in moral-economic norms. In this paper we focus on interindividual variations, and we report four studies showing that individuals cannot be swayed by financial incentives to conceal or to reveal, and follow instead fixed, idiosyncratic strategies. We discuss how this result can be extended to individual and cultural variations in the tendency to display or to hide unfair rewards. PMID:24066040

  19. Concealment of time delay signature of chaotic output in a slave semiconductor laser with chaos laser injection

    NASA Astrophysics Data System (ADS)

    Wu, Tianan; Sun, Weiyang; Zhang, Xiaoxu; Zhang, Shenghai

    2016-12-01

    An improved chaotic laser system, which has a slave semiconductor laser (SL) injected by a master SL with double optical feedback (DOF), is proposed, so that the time delay (TD) signature can be successfully concealed from both intensity and phase chaos via choosing appropriate parameters. The TD signature is investigated by employing autocorrelation function (ACF) and mutual information (MI) function. Through analyzing the influence on TD signature in the region of injection current and injection strength for the slave SL, we find that, for both intensity chaos and phase chaos, the TD signature can be easily concealed under weak injection strength. When the injection strength is strong, we can not only successfully conceal TD signature, but also improve the bandwidth of chaotic laser output by choosing the optimal detuning frequency.

  20. [Transaxillary concealing single incision endoscopic thoracic sympathectomy in the treatment of palmar hyperhidrosis: a novel surgical approach].

    PubMed

    Lin, Min; Tu, Yuan-rong; Lai, Fan-cai; Li, Xu; Chen, Jian-feng; Luo, Rong-gang; Lin, Jian-bo

    2013-11-05

    To evaluate the cosmetic effect and safety of transaxillary concealing single incision endoscopic thoracic sympathectomy in the treatment of palmar hyperhidrosis (PH). Retrospective study was conducted for 326 PH cases undergoing transaxillary concealing single incision endoscopic thoracic bilateral sympathectomy during January 2009 and March 2011. All operations were successfully performed without severe complication and mortality. No conversion into open technique was necessary. The mean unilateral operative duration was 5.8 (5-8) min. It was calculated from the time of skin incision to the application of dressing over wound. The mean follow-up period was 25 (8-38) months. All patients achieved excellent cosmetic effects with undetectable incision. Transaxillary concealing single incision endoscopic thoracic sympathectomy is a safe and effective procedure for treating primary PH. Incision is undetectable with excellent cosmetic effect. It is worthy of wider popularization.

  1. Emotional arousal modulates the encoding of crime-related details and corresponding physiological responses in the Concealed Information Test.

    PubMed

    Peth, Judith; Vossel, Gerhard; Gamer, Matthias

    2012-03-01

    Previous studies demonstrated that concealed crime-related memories can be validly identified using the Concealed Information Test (CIT). However, its field applicability is still debated, and it is specifically unknown how emotional arousal during a crime would influence CIT results. In the current study, emotional arousal during a mock crime and the time delay between mock crime and CIT examination were manipulated. At the immediate and the delayed CIT occasion, central crime details were better remembered than peripheral ones and enhanced emotional arousal further reduced memory for peripheral information. Electrodermal, respiratory, and cardiovascular responses to central crime details were strong and CIT validity was unaffected by delaying the test when arousal was induced during the mock crime. These findings indicate that emotional arousal might facilitate the detection of concealed information some time after a crime occurred. Copyright © 2011 Society for Psychophysiological Research.

  2. Contour Error Map Algorithm

    NASA Technical Reports Server (NTRS)

    Merceret, Francis; Lane, John; Immer, Christopher; Case, Jonathan; Manobianco, John

    2005-01-01

    The contour error map (CEM) algorithm and the software that implements the algorithm are means of quantifying correlations between sets of time-varying data that are binarized and registered on spatial grids. The present version of the software is intended for use in evaluating numerical weather forecasts against observational sea-breeze data. In cases in which observational data come from off-grid stations, it is necessary to preprocess the observational data to transform them into gridded data. First, the wind direction is gridded and binarized so that D(i,j;n) is the input to CEM based on forecast data and d(i,j;n) is the input to CEM based on gridded observational data. Here, i and j are spatial indices representing 1.25-km intervals along the west-to-east and south-to-north directions, respectively; and n is a time index representing 5-minute intervals. A binary value of D or d = 0 corresponds to an offshore wind, whereas a value of D or d = 1 corresponds to an onshore wind. CEM includes two notable subalgorithms: One identifies and verifies sea-breeze boundaries; the other, which can be invoked optionally, performs an image-erosion function for the purpose of attempting to eliminate river-breeze contributions in the wind fields.

  3. Remediating Common Math Errors.

    ERIC Educational Resources Information Center

    Wagner, Rudolph F.

    1981-01-01

    Explanations and remediation suggestions for five types of mathematics errors due either to perceptual or cognitive difficulties are given. Error types include directionality problems, mirror writing, visually misperceived signs, diagnosed directionality problems, and mixed process errors. (CL)

  4. A map overlay error model based on boundary geometry

    USGS Publications Warehouse

    Gaeuman, D.; Symanzik, J.; Schmidt, J.C.

    2005-01-01

    An error model for quantifying the magnitudes and variability of errors generated in the areas of polygons during spatial overlay of vector geographic information system layers is presented. Numerical simulation of polygon boundary displacements was used to propagate coordinate errors to spatial overlays. The model departs from most previous error models in that it incorporates spatial dependence of coordinate errors at the scale of the boundary segment. It can be readily adapted to match the scale of error-boundary interactions responsible for error generation on a given overlay. The area of error generated by overlay depends on the sinuosity of polygon boundaries, as well as the magnitude of the coordinate errors on the input layers. Asymmetry in boundary shape has relatively little effect on error generation. Overlay errors are affected by real differences in boundary positions on the input layers, as well as errors in the boundary positions. Real differences between input layers tend to compensate for much of the error generated by coordinate errors. Thus, the area of change measured on an overlay layer produced by the XOR overlay operation will be more accurate if the area of real change depicted on the overlay is large. The model presented here considers these interactions, making it especially useful for estimating errors studies of landscape change over time. ?? 2005 The Ohio State University.

  5. Brief Report: How Do They Manage Social Interaction? The Influence of Concealing Academic Achievement Information on Self-Monitoring by Adolescents with Low Achievement

    ERIC Educational Resources Information Center

    Zhang, Baoshan; Zhao, Jun-Yan; Yu, Guoliang

    2010-01-01

    During social interactions people self-monitor their behavior at least partially to conceal socially devalued characteristics. This study examined the influences of concealing academic achievement on self-monitoring in an academically-relevant social interaction. An interview paradigm called for school-aged adolescent participants (total N = 86)…

  6. The concealed information test as an instrument of applied differential psychophysiology: methodological considerations.

    PubMed

    Furedy, John J

    2009-09-01

    In this interpretative paper, I consider four sets of methodological issues that may be relevant to improving the concealed information test (CIT) as an instrument of applied differential psychophysiology. The first set has to do with psychophysiological measurement in the CIT (e.g., specific sensitivity testing in lab vs. field). Secondly, I consider the relationships between the psychological process of deception and the CIT. Thirdly, I consider the problem of laboratory-to-field generalization of the CIT, a consideration that includes a discussion of whether the lab/field differences are merely quantitative or actually qualitative. Finally, I discuss theories concerning the hypothetical mechanisms underlying the CIT, and argue that while the purely cognitive, Sokolovian, orienting response (OR) account is widely accepted as the sole mechanism, there is evidence to suggest that not just motivational, but even emotional mechanisms are also relevant.

  7. 220GHz wideband 3D imaging radar for concealed object detection technology development and phenomenology studies

    NASA Astrophysics Data System (ADS)

    Robertson, Duncan A.; Macfarlane, David G.; Bryllert, Tomas

    2016-05-01

    We present a 220 GHz 3D imaging `Pathfinder' radar developed within the EU FP7 project CONSORTIS (Concealed Object Stand-Off Real-Time Imaging for Security) which has been built to address two objectives: (i) to de-risk the radar hardware development and (ii) to enable the collection of phenomenology data with ~1 cm3 volumetric resolution. The radar combines a DDS-based chirp generator and self-mixing multiplier technology to achieve a 30 GHz bandwidth chirp with such high linearity that the raw point response is close to ideal and only requires minor nonlinearity compensation. The single transceiver is focused with a 30 cm lens mounted on a gimbal to acquire 3D volumetric images of static test targets and materials.

  8. Remote concealed weapon detection in millimeter-wave region: active and passive

    NASA Astrophysics Data System (ADS)

    Stanko, Stephan; Klöppel, Frank; Huck, Johann; Nötel, Denis; Hägelen, Manfred; Briese, Gunnar; Gregor, Alexander; Erukulla, Sreenivas; Fuchs, Hans-Hellmuth; Essen, Helmut; Pagels, Anke

    2006-09-01

    Sensors used for Security purposes have to cover the non-invasive inspection of persons, baggage and letters with the aim to detect weapons, explosives and chemical or biological threat material. Currently, emphasis is placed on system concepts and technologies for this type of applications, employing millimeterwave-, submillimeterwave- and terahertz sensors. This is based on the capability of these frequency bands to look through textiles and the possibility to achieve a geometric resolution which is sufficient to resolve critical items within the necessary range. Using multiple frequencies promises to give more detailed information about the structure of the observed objects. Furthermore, to overcome the limitations of passive millimeter- and submillimeterwave sensors which depend on indirect illumination, systems using miniaturized mmw-radar modules are applied as well. This paper describes two approaches for the detection of concealed weapons, the first using a millimeterwave radiometer on a scanner and the second employing a miniaturized radar module based on a synthetic aperture method.

  9. Event-related potentials increase the discrimination performance of the autonomic-based concealed information test.

    PubMed

    Matsuda, Izumi; Nittono, Hiroshi; Ogawa, Tokihiro

    2011-12-01

    The concealed information test (CIT) assesses an examinee's crime-relevant memory on the basis of physiological differences between crime-relevant and irrelevant items. The CIT based on autonomic measures has been used for criminal investigations, while the CIT based on event-related potentials (ERPs) has been suggested as a useful alternative. To combine these two methods, we developed a quantification method of ERPs measured in the autonomic-based CIT where each item was repeated only 5 times. Results showed that the peak amplitude of the ERP difference wave between crime-relevant and irrelevant items could discriminate between guilty and innocent participants effectively even when only 5 trials were used for averaging. This ERP measure could detect some participants who were missed by the autonomic measures. Combining the ERP and autonomic measures significantly improved the discrimination performance of the autonomic-based CIT.

  10. Intentional retrieval suppression can conceal guilty knowledge in ERP memory detection tests☆

    PubMed Central

    Bergström, Zara M.; Anderson, Michael C.; Buda, Marie; Simons, Jon S.; Richardson-Klavehn, Alan

    2013-01-01

    Brain-activity markers of guilty knowledge have been promoted as accurate and reliable measures for establishing criminal culpability. Tests based on these markers interpret the presence or absence of memory-related neural activity as diagnostic of whether or not incriminating information is stored in a suspect's brain. This conclusion critically relies on the untested assumption that reminders of a crime uncontrollably elicit memory-related brain activity. However, recent research indicates that, in some circumstances, humans can control whether they remember a previous experience by intentionally suppressing retrieval. We examined whether people could use retrieval suppression to conceal neural evidence of incriminating memories as indexed by Event-Related Potentials (ERPs). When people were motivated to suppress crime retrieval, their memory-related ERP effects were significantly decreased, allowing guilty individuals to evade detection. Our findings indicate that brain measures of guilty knowledge may be under criminals’ intentional control and place limits on their use in legal settings. PMID:23664804

  11. Management of adult concealed penis using a meshed, split-thickness skin graft

    PubMed Central

    Boonjindasup, Aaron; Pinsky, Michael; Stewart, Carrie; Trost, Landon; Chaffin, Abigail; Jansen, David; Hellstrom, Wayne

    2016-01-01

    Introduction Concealed penis (CP) is a rare problem faced by urologists and plastic surgeons. CP occurs secondary to trauma, obesity, or infection. Surgical treatment is individualized and based on patient and provider variables. We aim to review our recent experience using meshed split-thickness skin grafting (STSG) for CP management. Methods A retrospective review was performed on patients who underwent STSG for CP at our institution. Records were reviewed for demographic, operative, and postoperative variables. Preoperative and postoperative photos were obtained to monitor cosmetic results. Results Eleven patients underwent CP release with meshed STSG placement. All cases showed improved functional phallic length and good cosmetic results, regardless of etiology. Conclusions STSG is a viable option for penile coverage for management of this difficult-to-treat CP population. This primary or salvage modality offers excellent cosmetic results and may be used following prior reconstructive attempts. PMID:28096930

  12. Psychophysiological and behavioral measures for detecting concealed information: the role of memory for crime details.

    PubMed

    Nahari, Galit; Ben-Shakhar, Gershon

    2011-06-01

    This study examined the role of memory for crime details in detecting concealed information using the electrodermal measure, Symptom Validity Test, and Number Guessing Test. Participants were randomly assigned to three groups: guilty, who committed a mock theft; informed-innocents, who were exposed to crime-relevant items; and uninformed-innocents, who had no crime-relevant information. Participants were tested immediately or 1 week later. Results showed (a) all tests detected the guilty in the immediate condition, and combining the tests improved detection efficiency; (b) tests' efficiency declined in the delayed condition, mainly for peripheral details; (c) no distinction between guilty and informed innocents was possible in the immediate, yet some distinction emerged in the delayed condition. These findings suggest that, while time delay may somewhat reduce the ability to detect the guilty, it also diminishes the danger of accusing informed-innocents. Copyright © 2010 Society for Psychophysiological Research.

  13. Sexual harassment of girls in elementary school: a concealed phenomenon within a heterosexual romantic discourse.

    PubMed

    Gådin, Katja Gillander

    2012-06-01

    The aim of this study was to enhance the understanding of young girls' experiences of peer sexual harassment in elementary school and of normalizing processes of school-related sexualized violence. Six focus group interviews with girls in Grade 1 through 6 were carried out in an elementary school in the northern part of Sweden. A content analyses showed that young girls experienced verbal, nonverbal, and sexual assault behaviors at school. Sexual harassment as a concealed phenomenon and manifest within a romantic discourse were themes found in the analysis. A conclusion is that schools have to acknowledge behaviors related to sexual harassment as a potential problem even in young ages and develop methods to approach the subject also for this age group.

  14. Parenting beliefs and practices of opiate-addicted parents: concealment and taboo.

    PubMed

    Hogan, Diane M

    2003-07-01

    The lifestyle associated with opiate dependence, including drug taking, the buying and selling of drugs, and contact with other drug users, carries potential risks for the safety and well-being of children of drug-using parents. Based on a qualitative interview study conducted with 50 opiate-dependent parents in Dublin, Ireland, the parenting beliefs and practices in relation to children's exposure to drugs and the associated lifestyle are described. Parents saw their lifestyle as potentially risky for their children and their families. The most common strategy adopted by parents was to conceal their drug-related activities and maintain a strict family taboo about these activities. Intervention programmes should be offered to support effective family communication about parental drug dependence.

  15. The human operational sex ratio: effects of marriage, concealed ovulation, and menopause on mate competition.

    PubMed

    Marlowe, Frank W; Berbesque, J Colette

    2012-12-01

    Among mammals, male-male competition for sexual access to females frequently involves fighting. Larger body size gives males an advantage in fighting, which explains why males tend to be larger than females in many species, including anthropoid primates. Mitani et al. derived a formula to measure the operational sex ratio (OSR) to reflect the degree of male-male competition using the number of reproductively available males to females who are cycling and capable of conceiving. The OSR should predict the degree of sexual dimorphism in body mass-at least if male-male competition involves much fighting or threatening. Here, we use hunter-gatherer demographic data and the Mitani et al. formula to calculate the human OSR. We show that humans have a much lower degree of body mass sexual dimorphism than is predicted by our OSR. We suggest this is because human competition rarely involves fighting. In human hunter-gatherer societies, differences in the ages of marriage have an impact on competition in that the age of males at first marriage is younger when there is a lower percentage of married men with two or more wives, and older when there is a higher percentage of married men with two or more wives. We discuss the implications of this for females, along with the effects of two key life history traits that influence the OSR, concealed ovulation and menopause. While menopause decreases the number of reproductively available females to males and thus increases male-male competition, concealed ovulation decreases male-male competition. Finally, we discuss the importance of mostly monogamous mate bonds in human evolution.

  16. Doing everyday occupations both conceals and reveals the phenomenon of being aged.

    PubMed

    Wright-St Clair, Valerie A; Kerse, Ngaire; Smythe, Elizabeth

    2011-04-01

    The phenomenon of ageing is so commonplace that it is ordinarily taken-for-granted, with little call to question its meaning. Of importance to occupational therapists is the recent appeal to understand older adults' ordinary ways of everyday living. The aim of this interpretive phenomenological study was to understand the meaning of 'being aged' through the everyday experiences of those who are long-lived. The writings of two philosophers, Hans-Georg Gadamer and Martin Heidegger, guided the study's design and research methods. Being aged in the context of everyday living was the phenomenon of interest. Individual interviews were conducted with 15 community-dwelling New Zealand elders: four Maori aged 71-93 years and 11 non-Maori aged 80-97 years. Stories of going about daily occupations and particular moments in the day were elicited during conversational-style interviews. Hermeneutic methods and phenomenological reflection were used to analyse the data. Two overarching notions were illuminated. The ordinary ways of 'being in the every day', such as having a routine and a familiar purposefulness, conceal being aged. In contrast, 'experiencing the unaccustomed', such as suddenly noticing an unaccustomed weakness or oldness, in the midst of doing deeply familiar occupations is an announcing of being aged. CONCLUSIONS and As such, engaging in everyday, familiar occupations holds the potential to both conceal and reveal the phenomenon of being aged. These results point to the importance of illuminating the lived experience of occupational engagement as a fruitful way of informing occupation-focussed practice. © 2010 The Authors. Australian Occupational Therapy Journal © 2010 Australian Association of Occupational Therapists.

  17. Enhanced terahertz imaging system performance analysis and design tool for concealed weapon identification

    NASA Astrophysics Data System (ADS)

    Murrill, Steven R.; Franck, Charmaine C.; Espinola, Richard L.; Petkie, Douglas T.; De Lucia, Frank C.; Jacobs, Eddie L.

    2011-11-01

    The U.S. Army Research Laboratory (ARL) and the U.S. Army Night Vision and Electronic Sensors Directorate (NVESD) have developed a terahertz-band imaging system performance model/tool for detection and identification of concealed weaponry. The details of the MATLAB-based model which accounts for the effects of all critical sensor and display components, and for the effects of atmospheric attenuation, concealment material attenuation, and active illumination, were reported on at the 2005 SPIE Europe Security & Defence Symposium (Brugge). An advanced version of the base model that accounts for both the dramatic impact that target and background orientation can have on target observability as related to specular and Lambertian reflections captured by an active-illumination-based imaging system, and for the impact of target and background thermal emission, was reported on at the 2007 SPIE Defense and Security Symposium (Orlando). This paper will provide a comprehensive review of an enhanced, user-friendly, Windows-executable, terahertz-band imaging system performance analysis and design tool that now includes additional features such as a MODTRAN-based atmospheric attenuation calculator and advanced system architecture configuration inputs that allow for straightforward performance analysis of active or passive systems based on scanning (single- or line-array detector element(s)) or staring (focal-plane-array detector elements) imaging architectures. This newly enhanced THz imaging system design tool is an extension of the advanced THz imaging system performance model that was developed under the Defense Advanced Research Project Agency's (DARPA) Terahertz Imaging Focal-Plane Technology (TIFT) program. This paper will also provide example system component (active-illumination source and detector) trade-study analyses using the new features of this user-friendly THz imaging system performance analysis and design tool.

  18. Millimeter-wave concealed weapons detection and through-the-wall imaging systems

    NASA Astrophysics Data System (ADS)

    Huguenin, G. Richard

    1997-02-01

    Millimetrix' millimeter wave passive imaging technology offers the opportunity for rapid and remote detection of metallic and non-metallic weapons, plastic explosives, drugs, and other contraband concealed under multiple layers of clothing without the necessity of a direct physical search. The purely passive imaging technique relies solely on the existing natural emissions from the scene objects, does not expose the person to any man-made radiation, and is therefore completely harmless to the person being observed and to all others in the area. Screening can be done remotely and with as much discretion as the situation requires. The passive imaging approach to the detection of concealed weapons and contraband hidden under people's clothing works well at millimeter wavelengths because of a fortunate convergence of a number of key factors: (1) adequate resolution in a reasonable sensor size; (2) high transparency of virtually all clothing; and (3) the extraordinarily high emissivity of human flesh compared to the vast majority of other materials. Longer (microwave) wavelengths are impractical because of sensor size and resolution issues, and shorter (infrared) wavelengths are impractical because of the poor transparency of most clothing. The ability of millimeter wave emissions to penetrate many common building materials permits the remote observation, using active millimeter wave sensors, of people and other objects within a room from outside of that room. The resulting through-the-wall 'live' video images of people and furnishings will indicate their location, posture, and activity within a room which should be valuable knowledge to Special Operations, SWAT, and other military and law enforcement personnel prior to their entering that room. Millimeter wave radar imaging systems based on passive MillivisionR camera technology are being developed by Millimetrix (and other members of the MIRTAC TRP consortium) for through-the-wall imaging system (TWIS) applications.

  19. Analysis of potential dynamic concealed factors in the difficulty of lower third molar extraction

    PubMed Central

    Singh, Pradeep; Ajmera, Deepal-Haresh; Xiao, Shui-Sheng; Liu, Xiong; Peng, Bin

    2016-01-01

    Background The purpose of this study was to identify potential concealed variables associated with the difficulty of lower third molar (M3) extractions. Material and Methods To address the research purpose, we implemented a prospective study and enrolled a sample of subjects presenting for M3 removal. Predictor variables were categorized into Group-I and Group-II, based on predetermined criteria. The primary outcome variable was the difficulty of extraction, measured as extraction time. Appropriate univariate and multivariate statistics were computed using ordinal logistic regression. Results The sample comprised of 1235 subjects with a mean age of 29.49 +/- 8.92 years in Group-I and 26.20 +/- 11.55 years in Group-II subjects. The mean operating time per M3 extraction was 21.24 +/- 12.80 and 20.24 +/- 12.50 minutes for Group-I and Group-II subjects respectively. Three linear parameters including B-M2 height (distance between imaginary point B on the inferior border of mandibular body, and M2), lingual cortical thickness, bone density and one angular parameter including Rc-Cs angle (angle between ramus curvature and curve of spee), in addition to patient’s age, profile type, facial type, cant of occlusal plane, and decreased overbite, were found to be statistically associated (P < or = 0.05) with extraction difficulty under regression models. Conclusions In conclusion, our study indicates that the difficulty of lower M3 extractions is possibly governed by morphological and biomechanical factors with substantial influence of myofunctional factors. Practical Implications: Preoperative evaluation of dynamic concealed factors may not only help in envisaging the difficulty and planning of surgical approach but might also help in better time management in clinical practice. Key words:Third molar, impacted, extraction, mandibular, facial type. PMID:27694781

  20. Vitamin D and Musculoskeletal Status in Nova Scotian Women Who Wear Concealing Clothing

    PubMed Central

    Ojah, Rani C. I.; Welch, Jo M.

    2012-01-01

    Bone and muscle weakness due to vitamin D deficiency is common among Muslim women who reside in sunny, equatorial countries. The purpose of this study was to determine if living in a northern maritime location additionally disadvantages women who wear concealing clothes. A cross-sectional matched pair design was used to compare women who habitually wore concealing clothing with women who dressed according to western norms. Each premenopausal hijab-wearing woman (n = 11) was matched by age, height, weight and skin tone with a western-dressed woman. Subjects were tested by hand grip dynamometry to assess muscular strength and by quantitative ultrasound at the calcaneus to assess bone status. Nutritional intake was obtained by 24 h recall. Serum 25-hydroxyvitamin D (s-25(OH)D) status was determined in seven matched pairs. The hijab group had lower s-25(OH)D than women who wore western clothes (40 ± 28 vs. 81 ± 32 nmol/L, p= 0.01). Grip strength in the right hand was lower in the hijab-wearing women (p = 0.05) but this appeared to be due to less participation in intense exercise. Bone status did not differ between groups (p= 0.9). Dietary intake of vitamin D was lower in the hijab-wearers (316 ± 353 vs. 601 ± 341 IU/day, p= 0.001). This pilot study suggests that women living in a northern maritime location appear to be at risk for vitamin D insufficiency and therefore should consider taking vitamin D supplements. PMID:22690323

  1. Vitamin D and musculoskeletal status in Nova Scotian women who wear concealing clothing.

    PubMed

    Ojah, Rani C I; Welch, Jo M

    2012-05-01

    Bone and muscle weakness due to vitamin D deficiency is common among Muslim women who reside in sunny, equatorial countries. The purpose of this study was to determine if living in a northern maritime location additionally disadvantages women who wear concealing clothes. A cross-sectional matched pair design was used to compare women who habitually wore concealing clothing with women who dressed according to western norms. Each premenopausal hijab-wearing woman (n = 11) was matched by age, height, weight and skin tone with a western-dressed woman. Subjects were tested by hand grip dynamometry to assess muscular strength and by quantitative ultrasound at the calcaneus to assess bone status. Nutritional intake was obtained by 24 h recall. Serum 25-hydroxyvitamin D (s-25(OH)D) status was determined in seven matched pairs. The hijab group had lower s-25(OH)D than women who wore western clothes (40 ± 28 vs. 81 ± 32 nmol/L, p= 0.01). Grip strength in the right hand was lower in the hijab-wearing women (p = 0.05) but this appeared to be due to less participation in intense exercise. Bone status did not differ between groups (p= 0.9). Dietary intake of vitamin D was lower in the hijab-wearers (316 ± 353 vs. 601 ± 341 IU/day, p= 0.001). This pilot study suggests that women living in a northern maritime location appear to be at risk for vitamin D insufficiency and therefore should consider taking vitamin D supplements.

  2. Unmasking Subtle and Concealed Aspects of Parent Involvement: Perspectives from African-American Parents in the Urban South

    ERIC Educational Resources Information Center

    Loder-Jackson, Tondra L.; McKnight, Andrew N.; Brooks, Michael; McGrew, Kenneth; Voltz, Deborah

    2007-01-01

    Focus group findings from 34 African American parents in an urban southern school district unmask subtle and concealed aspects of involvement. In contrast to formalized school-sponsored parent activities, involvement is described by participants as their encompassing a physical presence at the school to monitor their children's behavior, receiving…

  3. Self-Concealment, Social Network Sites Usage, Social Appearance Anxiety, Loneliness of High School Students: A Model Testing

    ERIC Educational Resources Information Center

    Dogan, Ugur; Çolak, Tugba Seda

    2016-01-01

    This study was tested a model for explain to social networks sites (SNS) usage with structural equation modeling (SEM). Using SEM on a sample of 475 high school students (35% male, 65% female) students, model was investigated the relationship between self-concealment, social appearance anxiety, loneliness on SNS such as Twitter and Facebook usage.…

  4. Geochemical Data for Samples Collected in 2008 Near the Concealed Pebble Porphyry Cu-Au-Mo Deposit, Southwest Alaska

    USGS Publications Warehouse

    Fey, David L.; Granitto, Matthew; Giles, Stuart A.; Smith, Steven M.; Eppinger, Robert G.; Kelley, Karen D.

    2009-01-01

    In the summer of 2007, the U.S. Geological Survey (USGS) began an exploration geochemical research study over the Pebble porphyry copper-gold-molybdenum deposit. This report presents the analytical data collected in 2008. The Pebble deposit is world class in size, and is almost entirely concealed by tundra, glacial deposits, and post-Cretaceous volcanic rocks. The Pebble deposit was chosen for this study because it is concealed by surficial cover rocks, is relatively undisturbed (except for exploration company drill holes), is a large mineral system, and is fairly well-constrained at depth by the drill hole geology and geochemistry. The goals of this study are to 1) determine whether the concealed deposit can be detected with surface samples, 2) better understand the processes of metal migration from the deposit to the surface, and 3) test and develop methods for assessing mineral resources in similar concealed terrains. The analytical data are presented as an integrated Microsoft Access 2003 database and as separate Excel files.

  5. Disclosure and Concealment of Sexual Orientation and the Mental Health of Non-Gay-Identified, Behaviorally Bisexual Men

    ERIC Educational Resources Information Center

    Schrimshaw, Eric W.; Siegel, Karolynn; Downing, Martin J., Jr.; Parsons, Jeffrey T.

    2013-01-01

    Objective: Although bisexual men report lower levels of mental health relative to gay men, few studies have examined the factors that contribute to bisexual men's mental health. Bisexual men are less likely to disclose, and more likely to conceal (i.e., a desire to hide), their sexual orientation than gay men. Theory suggests that this may…

  6. The incidence and outcome of concealed pregnancies among hospital deliveries: an 11-year population-based study in South Glamorgan.

    PubMed

    Nirmal, D; Thijs, I; Bethel, J; Bhal, P S

    2006-02-01

    Denial of pregnancy has been implicated in potentially jeopardising prenatal care and subsequent safe planned deliveries. This population-based study of hospital deliveries over an 11-year period, reveals that concealed pregnancies have an incidence of one in 2,500 deliveries. Among this cohort, 12% were married and 58% were multiparous with 8% having had a previous caesarean section. Some 20% of women had a medical disorder complicating the antenatal period. There was a preponderance of concealed pregnancies in the winter months compared with booked deliveries (p = 0.02). Mode of delivery was similar between the booked and concealed pregnancies with a low incidence of maternal morbidity in the latter. Prematurity rates (p = 0.0002) were significantly higher in the concealed pregnancy cohort. A total of 20% of infants had depressed Apgar scores at 1 min and 8% at 5 min. There was no documentation of counselling or follow-up in this group. Despite the low incidence of maternal morbidity, these women should be regarded as high-risk labour due to the increased perinatal morbidity. Greater effort needs to be made towards ensuring these women have adequate counselling and follow-up during the postnatal period.

  7. P300 amplitudes in the concealed information test are less affected by depth of processing than electrodermal responses

    PubMed Central

    Gamer, Matthias; Berti, Stefan

    2012-01-01

    The Concealed Information Test (CIT) has been used in the laboratory as well as in field applications to detect concealed crime related memories. The presentation of crime relevant details to guilty suspects has been shown to elicit enhanced N200 and P300 amplitudes of the event-related brain potentials (ERPs) as well as greater skin conductance responses (SCRs) as compared to neutral test items. These electrophysiological and electrodermal responses were found to incrementally contribute to the validity of the test, thereby suggesting that these response systems are sensitive to different psychological processes. In the current study, we tested whether depth of processing differentially affects N200, P300, and SCR amplitudes in the CIT. Twenty participants carried out a mock crime and became familiar with central and peripheral crime details. A CIT that was conducted 1 week later revealed that SCR amplitudes were larger for central details although central and peripheral items were remembered equally well in a subsequent explicit memory test. By contrast, P300 amplitudes elicited by crime related details were larger but did not differ significantly between question types. N200 amplitudes did not allow for detecting concealed knowledge in this study. These results indicate that depth of processing might be one factor that differentially affects central and autonomic nervous system responses to concealed information. Such differentiation might be highly relevant for field applications of the CIT. PMID:23162454

  8. Africentric Cultural Values, Psychological Help-Seeking Attitudes, and Self-Concealment in African American College Students

    ERIC Educational Resources Information Center

    Wallace, Barbara C.; Constantine, Madonna G.

    2005-01-01

    This study investigated the relationships among Africentric cultural values (i.e., the extent to which an individual adheres to a worldview emphasizing communalism, unity, harmony, spirituality, and authenticity), favorable psychological help-seeking attitudes, perceived counseling stigma, and self-concealment (i.e., the tendency to withhold…

  9. Disclosure and Concealment of Sexual Orientation and the Mental Health of Non-Gay-Identified, Behaviorally Bisexual Men

    ERIC Educational Resources Information Center

    Schrimshaw, Eric W.; Siegel, Karolynn; Downing, Martin J., Jr.; Parsons, Jeffrey T.

    2013-01-01

    Objective: Although bisexual men report lower levels of mental health relative to gay men, few studies have examined the factors that contribute to bisexual men's mental health. Bisexual men are less likely to disclose, and more likely to conceal (i.e., a desire to hide), their sexual orientation than gay men. Theory suggests that this may…

  10. Limitation of tachycardia zone resulting from longitudinal dissociation of the atrioventricular node in concealed pre-excitation.

    PubMed Central

    Littmann, L; Svenson, R H

    1981-01-01

    Two cases with a concealed left-sided accessory atrioventricular bypass tract are described. In both, functional longitudinal dissociation of the atrioventricular node narrowed the range of atrial premature beat coupling intervals which could initiate re-entry using the accessory pathway. In case 1 early premature atrial beats were followed by an atrioventricular nodal re-entrant echo. The atrial echo pre-empted retrograde conduction over the Kent bundle and thus limited the development of paroxysmal supraventricular tachycardia. In case 2 atrioventricular nodal conduction showed typical features ascribed to dual atrioventricular nodal pathways. In addition there was a bradycardia-related retrograde block in the concealed accessory pathway. Early premature atrial beats, because of exclusive "slow pathway" anterograde conduction, arrived at the ventricles during the period of bradycardia-dependent retrograde block and failed to initiate a macro re-entrant tachycardia. This study shows that (1) longitudinal dissociation within the atrioventricular node may limit the ability to initiate tachycardia in patients with concealed pre-excitation; and (2) discontinuous atrioventricular nodal conduction curves occasionally help to reveal bradycardia-related retrograde block in a concealed accessory pathway. PMID:7295423

  11. Medication errors: prescribing faults and prescription errors

    PubMed Central

    Velo, Giampaolo P; Minuz, Pietro

    2009-01-01

    Medication errors are common in general practice and in hospitals. Both errors in the act of writing (prescription errors) and prescribing faults due to erroneous medical decisions can result in harm to patients. Any step in the prescribing process can generate errors. Slips, lapses, or mistakes are sources of errors, as in unintended omissions in the transcription of drugs. Faults in dose selection, omitted transcription, and poor handwriting are common. Inadequate knowledge or competence and incomplete information about clinical characteristics and previous treatment of individual patients can result in prescribing faults, including the use of potentially inappropriate medications. An unsafe working environment, complex or undefined procedures, and inadequate communication among health-care personnel, particularly between doctors and nurses, have been identified as important underlying factors that contribute to prescription errors and prescribing faults. Active interventions aimed at reducing prescription errors and prescribing faults are strongly recommended. These should be focused on the education and training of prescribers and the use of on-line aids. The complexity of the prescribing procedure should be reduced by introducing automated systems or uniform prescribing charts, in order to avoid transcription and omission errors. Feedback control systems and immediate review of prescriptions, which can be performed with the assistance of a hospital pharmacist, are also helpful. Audits should be performed periodically. PMID:19594530

  12. Polygraphy and Functional Magnetic Resonance Imaging in Lie Detection: A Controlled Blind Comparison Using the Concealed Information Test.

    PubMed

    Langleben, Daniel D; Hakun, Jonathan G; Seelig, David; Wang, An-Li; Ruparel, Kosha; Bilker, Warren B; Gur, Ruben C

    2016-10-01

    Intentional deception is a common act that often has detrimental social, legal, and clinical implications. In the last decade, brain activation patterns associated with deception have been mapped with functional magnetic resonance imaging (fMRI), significantly expanding our theoretical understanding of the phenomenon. However, despite substantial criticism, polygraphy remains the only biological method of lie detection in practical use today. We conducted a blind, prospective, and controlled within-subjects study to compare the accuracy of fMRI and polygraphy in the detection of concealed information. Data were collected between July 2008 and August 2009. Participants (N = 28) secretly wrote down a number between 3 and 8 on a slip of paper and were questioned about what number they wrote during consecutive and counterbalanced fMRI and polygraphy sessions. The Concealed Information Test (CIT) paradigm was used to evoke deceptive responses about the concealed number. Each participant's preprocessed fMRI images and 5-channel polygraph data were independently evaluated by 3 fMRI and 3 polygraph experts, who made an independent determination of the number the participant wrote down and concealed. Using a logistic regression, we found that fMRI experts were 24% more likely (relative risk = 1.24, P < .001) to detect the concealed number than the polygraphy experts. Incidentally, when 2 out of 3 raters in each modality agreed on a number (N = 17), the combined accuracy was 100%. These data justify further evaluation of fMRI as a potential alternative to polygraphy. The sequential or concurrent use of psychophysiology and neuroimaging in lie detection also deserves new consideration.

  13. Quantum error correction for continuously detected errors

    NASA Astrophysics Data System (ADS)

    Ahn, Charlene; Wiseman, H. M.; Milburn, G. J.

    2003-05-01

    We show that quantum feedback control can be used as a quantum-error-correction process for errors induced by a weak continuous measurement. In particular, when the error model is restricted to one, perfectly measured, error channel per physical qubit, quantum feedback can act to perfectly protect a stabilizer codespace. Using the stabilizer formalism we derive an explicit scheme, involving feedback and an additional constant Hamiltonian, to protect an (n-1)-qubit logical state encoded in n physical qubits. This works for both Poisson (jump) and white-noise (diffusion) measurement processes. Universal quantum computation is also possible in this scheme. As an example, we show that detected-spontaneous emission error correction with a driving Hamiltonian can greatly reduce the amount of redundancy required to protect a state from that which has been previously postulated [e.g., Alber et al., Phys. Rev. Lett. 86, 4402 (2001)].

  14. Field error lottery

    SciTech Connect

    Elliott, C.J.; McVey, B. ); Quimby, D.C. )

    1990-01-01

    The level of field errors in an FEL is an important determinant of its performance. We have computed 3D performance of a large laser subsystem subjected to field errors of various types. These calculations have been guided by simple models such as SWOOP. The technique of choice is utilization of the FELEX free electron laser code that now possesses extensive engineering capabilities. Modeling includes the ability to establish tolerances of various types: fast and slow scale field bowing, field error level, beam position monitor error level, gap errors, defocusing errors, energy slew, displacement and pointing errors. Many effects of these errors on relative gain and relative power extraction are displayed and are the essential elements of determining an error budget. The random errors also depend on the particular random number seed used in the calculation. The simultaneous display of the performance versus error level of cases with multiple seeds illustrates the variations attributable to stochasticity of this model. All these errors are evaluated numerically for comprehensive engineering of the system. In particular, gap errors are found to place requirements beyond mechanical tolerances of {plus minus}25{mu}m, and amelioration of these may occur by a procedure utilizing direct measurement of the magnetic fields at assembly time. 4 refs., 12 figs.

  15. Inborn errors of metabolism

    MedlinePlus

    Metabolism - inborn errors of ... Bodamer OA. Approach to inborn errors of metabolism. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 205. Rezvani I, Rezvani G. An ...

  16. Accounting for Interlanguage Errors

    ERIC Educational Resources Information Center

    Benetti, Jean N.

    1978-01-01

    A study was conducted to test various explanations of the error of unmarked noun plurals made by first generation Italian immigrants. The error appeared to be "fossilized" or not eradicated over a period of time. (SW)

  17. Drug Errors in Anaesthesiology

    PubMed Central

    Jain, Rajnish Kumar; Katiyar, Sarika

    2009-01-01

    Summary Medication errors are a leading cause of morbidity and mortality in hospitalized patients. The incidence of these drug errors during anaesthesia is not certain. They impose a considerable financial burden to health care systems apart from the patient losses. Common causes of these errors and their prevention is discussed. PMID:20640103

  18. Programming Errors in APL.

    ERIC Educational Resources Information Center

    Kearsley, Greg P.

    This paper discusses and provides some preliminary data on errors in APL programming. Data were obtained by analyzing listings of 148 complete and partial APL sessions collected from student terminal rooms at the University of Alberta. Frequencies of errors for the various error messages are tabulated. The data, however, are limited because they…

  19. Concealment, communication and stigma: The perspectives of HIV-positive immigrant Black African men and their partners living in the United Kingdom.

    PubMed

    Owuor, John Oa; Locke, Abigail; Heyman, Bob; Clifton, Andrew

    2016-12-01

    This study explored the perspectives of Black men, originally from East Africa, living in the United Kingdom and their partners on what it means to live with diagnosed HIV. This article reports on concealment of HIV-positive status as a strategy adopted by the affected participants to manage the flow of information about their HIV-positive status. Analysis of the data, collected using in-depth interviews involving 23 participants, found widespread selective concealment of HIV-positive status. However, a few respondents had 'come out' publicly about their condition. HIV prevention initiatives should recognise concealment as a vital strategy in managing communication about one's HIV-positive status.

  20. Direction Judgement Errors in Perspective Displays

    NASA Technical Reports Server (NTRS)

    Mcgreevy, M. W.; Ellis, S. R.

    1984-01-01

    Spatial information transfer characteristics of perspective situation displays were investigated by having eight subjects judge the directions of displayed targets relative to a fixed position in the center of computer generated perspective scenes. Their errors in judging azimuth angles varied sinusoidally with the azimuth of the targets. Errors alternated between clockwise and counterclock wise from one direction quadrant to the next. As the perspective geometry was varied between telephoto lens and wide angle lens views, the direction of error gradually reversed in all quadrants. The results can be explained by systematic differences between the three-dimensional stimulus angles and the perspective projections of those angles onto the display screen.

  1. Detection of contraband concealed on the body using x-ray imaging

    NASA Astrophysics Data System (ADS)

    Smith, Gerald J.

    1997-01-01

    In an effort to avoid detection, smugglers and terrorists are increasingly using the body as a vehicle for transporting illicit drugs, weapons, and explosives. This trend illustrates the natural tendency of traffickers to seek the path of least resistance, as improved interdiction technology and operational effectiveness have been brought to bear on other trafficking avenues such as luggage, cargo, and parcels. In response, improved technology for human inspection is being developed using a variety of techniques. ASE's BodySearch X-ray Inspection Systems uses backscatter x-ray imaging of the human body to quickly, safely, and effectively screen for drugs, weapons, and explosives concealed on the body. This paper reviews the law enforcement and social issues involved in human inspections, and briefly describes the ASE BodySearch systems. Operator training, x-ray image interpretation, and maximizing systems effectiveness are also discussed. Finally, data collected from operation of the BodySearch system in the field is presented, and new law enforcement initiatives which have come about due to recent events are reviewed.

  2. A new approach to analyze data from EEG-based concealed face recognition system.

    PubMed

    Mehrnam, A H; Nasrabadi, A M; Ghodousi, Mahrad; Mohammadian, A; Torabi, Sh

    2017-02-10

    The purpose of this study is to extend a feature set with non-linear features to improve classification rate of guilty and innocent subjects. Non-linear features can provide extra information about phase space. The Event-Related Potential (ERP) signals were recorded from 49 subjects who participated in concealed face recognition test. For feature extraction, at first, several morphological characteristics, frequency bands, and wavelet coefficients (we call them basic-features) are extracted from each single-trial ERP. Recurrence Quantification Analysis (RQA) measures are then computed as non-linear features from each single-trial. We apply Genetic Algorithm (GA) to select the best feature set and this feature set is used for classification of data using Linear Discriminant Analysis (LDA) classifier. Next, we use a new approach to improve classification results based on introducing an adaptive-threshold. Results indicate that our method is able to correctly detect 91.83% of subjects (45 correct detection of 49 subjects) using combination of basic and non-linear features, that is higher than 87.75% for basic and 79.59% for non-linear features. This shows that combination of non-linear and basic- features could improve classification rate.

  3. A scream from the past: a multidisciplinary approach in a concealment of a corpse found mummified.

    PubMed

    Gitto, Lorenzo; Bonaccorso, Luigi; Maiese, Aniello; dell'Aquila, Massimiliano; Arena, Vincenzo; Bolino, Giorgio

    2015-05-01

    When a mummified body is found, it requires the forensic pathologist to determine the manner and cause of death. The mummified body of an older man was found walled in an alcove in a silicon-sealed bedroom, in a semi-supine position with the back on the floor and the legs on the wall. Two plastic bags covered the body. Having removed the plastic bags, the body was fully wrapped in a brown adhesive tape. At the scene, there was no evidence of microfauna. The subject's son stated that after his father's death, he concealed the corpse in order to obtain his annual pension. A postmortem CT scan was performed before the autopsy, which excluded traumatic injuries. The autopsy together with the toxicological and microscopic findings helped us to understand the manner of death. In this case, the mummification process developed under specific environmental conditions and a multidisciplinary approach was required in order to solve it. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  4. Effects of coping and cooperative instructions on guilty and informed innocents' physiological responses to concealed information.

    PubMed

    Zvi, Liza; Nachson, Israel; Elaad, Eitan

    2012-05-01

    Previous research on the Concealed Information Test indicates that knowledge of the critical information of a given event is sufficient for the elicitation of strong physiological reactions, thus facilitating detection by the test. Other factors that affect the test's efficacy are deceptive verbal responses to the test's questions and motivation of guilty examinees to avoid detection. In the present study effects of coping and cooperative instructions - delivered to guilty and innocent participants - on detection were examined. In a mock-theft experiment guilty participants who actually committed a mock-crime, and informed innocent participants who handled the critical items of the crime in an innocent context, were instructed to adopt either a coping or a cooperative attitude toward the polygraph test. Results indicated that both, guilt and coping behavior, were associated with enhanced physiological responses to the critical information, whereas innocence and cooperative behavior attenuated physiological responses. Theoretical and applied implications of the results are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Instant detection and identification of concealed explosive-related compounds: Induced Stokes Raman versus infrared.

    PubMed

    Elbasuney, Sherif; El-Sherif, Ashraf F

    2017-01-01

    The instant detection of explosives and explosive-related compounds has become an urgent priority in recent years for homeland security and counter-terrorism applications. Modern techniques should offer enhancement in selectivity, sensitivity, and standoff distances. Miniaturisation, portability, and field-ruggedisation are crucial requirements. This study reports on instant and standoff identification of concealed explosive-related compounds using customized Raman technique. Stokes Raman spectra of common explosive-related compounds were generated and spectrally resolved to create characteristic finger print spectra. The scattered Raman emissions over the band 400:2000cm(-1) were compared to infrared absorption using FTIR. It has been demonstrated that the two vibrational spectroscopic techniques were opposite and completing each other. Molecular vibrations with strong absorption in infrared (those involve strong change in dipole moments) induced weak signals in Raman and vice versa. The tailored Raman offered instant detection, high sensitivity, and standoff detection capabilities. Raman demonstrated characteristic fingerprint spectra with stable baseline and sharp intense peaks. Complete correlations of absorption/scattered signals to certain molecular vibrations were conducted to generate an entire spectroscopic profile of explosive-related compounds. This manuscript shades the light on Raman as one of the prevailing technologies for instantaneous detection of explosive-related compounds. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Shall-issue policy and criminal activity among applicants for permits to carry concealed firearms.

    PubMed

    Romero, M; Wintemute, G; Wright, M; Parham, C

    2003-12-01

    Permits to carry concealed firearms in public (CCW permits) remain controversial. A small scale natural experiment with shall-issue CCW permit policy in California, a may-issue state, is reported. During the mid-1990s, the chief of police of the Sacramento County town of Isleton issued permits to all county residents who applied and passed a standard background check. This program received national publicity. The incidence of subsequent criminal activity among 691 persons applying for CCW permits through Isleton's program in 1995 and that in a statewide sample of 965 CCW applicants from 1993-94 were compared. Subjects were followed up for three years from their application dates. The arrest rates for violent crime among Isleton and statewide applicants were 291 and 104 per 100 000 person-years, respectively (relative risk 2.8, 95% confidence interval 0.7 to 11.2, p = 0.18). This suggests that a shall-issue policy for CCW permits may result in higher rates of violent crime among permit holders, but the results do not reach statistical significance; larger studies are needed.

  7. A possible concealed pluton in Beaverhead and Madison Counties, Montana, and Clark County, Idaho

    USGS Publications Warehouse

    Witkind, Irving Jerome

    1974-01-01

    A northeast-trending magnetic anomaly in parts of Beaverhead and Madison Counties, Mont., and Clark County, Idaho, may reflect the trend, shape, and size of a concealed pluton. The type of rock that forms the pluton(?) is unknown. A small volcanic pipe, possibly a diatreme, is at the southeast end of the high. The pipe, about 92 m (300 ft) in diameter, consists of a rubbly basalt-like matrix through which are scattered xenoliths of Precambrian crystalline rocks and of various Paleozoic and Mesozoic strata. It is uncertain whether the juxtaposition of the pipe and the magnetic high is meaningful or is merely fortuitous. Although no mineralized rock was found in the area underlain by the anomaly, placer gold has been found nearby. Some 113 km (70 mi) to the west, in Custer and Lemhi Counties, Idaho, a similar northeast-trending magnetic high marks the site of the Gilmore mining district. The similarities in trend, shape, and magnitude between the two anomalies suggest that the high in Beaverhead and Madison Counties should be investigated for undetected mineral deposits, possibly by a geochemical survey.

  8. Mobile TNA system to detect explosives and drugs concealed in cars and trucks

    NASA Astrophysics Data System (ADS)

    Bendahan, Joseph; Gozani, Tsahi

    1998-12-01

    The drug problem in the U.S. is serious and efforts to fight it are constrained by the lack of adequate means to curb the inflow of smuggled narcotics into the country through cargo containers. Also, events such as the disastrous explosion in Oklahoma City, the IRA bombing in London, and the bombing of the U.S. military residence in Dharan make the development of new tools for the detection of explosives and drugs in vehicles imperative. Thermal neutron analysis (TNA) technology, developed for the detection of explosives in suitcases, and detection of landmines and unexploded ordnance is presently being applied to the nonintrusive detection of significant amounts of explosives and drugs concealed in cars, trucks and large cargo containers. TNA technology is based on the analysis of characteristic gamma rays emitted following thermal neutron capture. A TNA system can be used in a variety of operational scenarios, such as inspection before an unloaded cargo container from a spit is moved to temporary storage, inspection of trucks unloaded from a ferry, or inspection of vehicles parked close to Federal building or military bases. This paper will discuss the detection process and operational scenarios, and will present results from recent simulations and measurements.

  9. Effect of Temperature and Moisture on the Development of Concealed Damage in Raw Almonds (Prunus dulcis).

    PubMed

    Rogel-Castillo, Cristian; Zuskov, David; Chan, Bronte Lee; Lee, Jihyun; Huang, Guangwei; Mitchell, Alyson E

    2015-09-23

    Concealed damage (CD) is a brown discoloration of nutmeat that appears only after kernels are treated with moderate heat (e.g., roasting). Identifying factors that promote CD in almonds is of significant interest to the nut industry. Herein, the effect of temperature (35 and 45 °C) and moisture (<5, 8, and 11%) on the composition of volatiles in raw almonds (Prunus dulcis var. Nonpareil) was studied using HS-SPME-GC/MS. A CIE LCh colorimetric method was developed to identify raw almonds with CD. A significant increase in CD was demonstrated in almonds exposed to moisture (8% kernel moisture content) at 45 °C as compared to 35 °C. Elevated levels of volatiles related to lipid peroxidation and amino acid degradation were observed in almonds with CD. These results suggest that postharvest moisture exposure resulting in an internal kernel moisture ≥ 8% is a key factor in the development of CD in raw almonds and that CD is accelerated by temperature.

  10. Effect of Drying Moisture Exposed Almonds on the Development of the Quality Defect Concealed Damage.

    PubMed

    Rogel-Castillo, Cristian; Luo, Kathleen; Huang, Guangwei; Mitchell, Alyson E

    2017-10-02

    Concealed damage (CD), is a term used by the nut industry to describe a brown discoloration of kernel nutmeat that becomes visible after moderate heat treatments (e.g., roasting). CD can result in consumer rejection and product loss. Postharvest exposure of almonds to moisture (e.g., rain) is a key factor in the development of CD as it promotes hydrolysis of proteins, carbohydrates, and lipids. The effect of drying moisture-exposed almonds between 45 to 95 °C, prior to roasting was evaluated as a method for controlling CD in roasted almonds. Additionally, moisture-exposed almonds dried at 55 and 75 °C were stored under accelerated shelf life conditions (45 °C/80% RH) and evaluated for headspace volatiles. Results indicate that drying temperatures below 65 °C decreases brown discoloration of nutmeat up to 40% while drying temperatures above 75 °C produce significant increases in brown discoloration and volatiles related to lipid oxidation, and nonsignificant increases in Amadori compounds. Results also demonstrate that raw almonds exposed to moisture and dried at 55 °C prior to roasting, reduce the visual sign of CD and maintain headspace volatiles profiles similar to almonds without moisture damage during accelerated storage.

  11. Improved method for calculating the respiratory line length in the Concealed Information Test.

    PubMed

    Matsuda, Izumi; Ogawa, Tokihiro

    2011-08-01

    The Concealed Information Test (CIT) assesses an examinee's knowledge about a crime based on response differences between crime-relevant and crime-irrelevant items. One effective measure in the CIT is the respiration line length, which is the average of the moving distances of the respiration curve in a specified time interval after the item onset. However, the moving distance differs between parts of a respiratory cycle. As a result, the calculated respiration line length is biased by how the parts of the respiratory cycles are included in the time interval. To resolve this problem, we propose a weighted average method, which calculates the respiration line length per cycle and weights it with the proportion that the cycle occupies in the time interval. Simulation results indicated that the weighted average method removes the bias of respiration line lengths compared to the original method. The results of experimental CIT data demonstrated that the weighted average method significantly increased the discrimination performance as compared with the original method. The weighted average method is a promising method for assessing respiration changes in response to question items more accurately, which improves the respiration-based discrimination performance of the CIT.

  12. [Effects of recollection and familiarity on recognition memory in the Concealed Information Test].

    PubMed

    Zaitsu, Wataru; Shibuya, Yusuke

    2013-08-01

    The effects of recollection and familiarity on recognition memory in the Concealed Information Test (CIT) were investigated. In the learning phase, participants encoded 20 words that were presented in one of four frames on a personal computer screen. Next, in the recognition test, the participants were divided into "Remember judgment (Recollection)" or "Know judgment (Familiarity)" groups, based on their Remember/Know judgment when recognizing learned items. In the CIT phase, physiological responses to questions about learned (i.e., critical) and non-learned (i.e., non-critical) items were measured and recorded. The results indicated that there was a deceleration of respiration speed (RS), an increase in skin conductance response (SCR), and a drop in heart rate in responses to critical items for both groups. Furthermore, the effect sizes of RS and SCR were greater in the "Remember judgment" group compared to the "Know judgment" group. These results suggest that critical response patterns are generated by recollection and familiarity. However, the more vividly participants recognized critical items the larger were the magnitudes of RS and SCR response patterns.

  13. Physiological responses in a Concealed Information Test are determined interactively by encoding procedure and questioning format.

    PubMed

    Ambach, Wolfgang; Dummel, Sebastian; Lüer, Theresa; Vaitl, Dieter

    2011-09-01

    Physiological responses in the Concealed Information Test (CIT) are known to depend on the depth of encoding critical items; CIT questions commonly refer to knowledge about critical items. It is unclear to what extent (1) different modes of item handling in a mock-crime, and (2) alternative questioning formats, e.g. asking about participants' particular actions with the critical items, influence the physiological responses. In the presented mock-crime study with fifty-three participants, two questioning formats, i.e. "Did you see …?" (viewing questioning) and "Did you steal …?" (stealing questioning), were compared between subjects. The mode of encoding, stealing vs. merely viewing the critical objects, was varied within subject. Skin conductance, electrocardiogram, respiration, and finger pulse were recorded. For both questioning formats and each physiological measure, physiological responses to stolen as well as merely viewed objects differed from those to irrelevant objects. Considering viewing questioning, responses to stolen and merely viewed objects did not differ, with the exception of greater phasic decreases of heart rate for stolen objects. Considering stealing questioning, responses to stolen objects exceeded those to merely viewed objects with each physiological measure. The statistically proven interaction between mode of encoding a particular object and questioning format sheds light on the factors influencing the physiological responses in a CIT. The level of subjective significance of a particular item might emerge interactively from the mode of item handling and the questioning format.

  14. Detection and classification of concealed weapons using a magnetometer-based portal

    NASA Astrophysics Data System (ADS)

    Kotter, Dale K.; Roybal, Lyle G.; Polk, Robert E.

    2002-08-01

    A concealed weapons detection technology was developed through the support of the National Institute of Justice (NIJ) to provide a non intrusive means for rapid detection, location, and archiving of data (including visual) of potential suspects and weapon threats. This technology, developed by the Idaho National Engineering and Environmental Laboratory (INEEL), has been applied in a portal style weapons detection system using passive magnetic sensors as its basis. This paper will report on enhancements to the weapon detection system to enable weapon classification and to discriminate threats from non-threats. Advanced signal processing algorithms were used to analyze the magnetic spectrum generated when a person passes through a portal. These algorithms analyzed multiple variables including variance in the magnetic signature from random weapon placement and/or orientation. They perform pattern recognition and calculate the probability that the collected magnetic signature correlates to a known database of weapon versus non-weapon responses. Neural networks were used to further discriminate weapon type and identify controlled electronic items such as cell phones and pagers. False alarms were further reduced by analyzing the magnetic detector response by using a Joint Time Frequency Analysis digital signal processing technique. The frequency components and power spectrum for a given sensor response were derived. This unique fingerprint provided additional information to aid in signal analysis. This technology has the potential to produce major improvements in weapon detection and classification.

  15. A novel concealed information test method based on independent component analysis and support vector machine.

    PubMed

    Gao, Junfeng; Lu, Liang; Yang, Yong; Yu, Gang; Na, Liantao; Rao, NiNi

    2012-01-01

    The concealed information test (CIT) has drawn much attention and has been widely investigated in recent years. In this study, a novel CIT method based on denoised P3 and machine learning was proposed to improve the accuracy of lie detection. Thirty participants were chosen as the guilty and innocent participants to perform the paradigms of 3 types of stimuli. The electroencephalogram (EEG) signals were recorded and separated into many single trials. In order to enhance the signal noise ratio (SNR) of P3 components, the independent component analysis (ICA) method was adopted to separate non-P3 components (i.e., artifacts) from every single trial. In order to automatically identify the P3 independent components (ICs), a new method based on topography template was proposed to automatically identify the P3 ICs. Then the P3 waveforms with high SNR were reconstructed on Pz electrodes. Second, the 3 groups of features based on time,frequency, and wavelets were extracted from the reconstructed P3 waveforms. Finally, 2 classes of feature samples were used to train a support vector machine (SVM) classifier because it has higher performance compared with several other classifiers. Meanwhile, the optimal number of P3 ICs and some other parameter values in the classifiers were determined by the cross-validation procedures. The presented method achieved a balance test accuracy of 84.29% on detecting P3 components for the guilty and innocent participants. The presented method improves the efficiency of CIT in comparison with previous reported methods.

  16. Adipocere formation via hydrogenation of linoleic acid in a victim kept under dry concealment.

    PubMed

    Nushida, Hideyuki; Adachi, Junko; Takeuchi, Atsuko; Asano, Migiwa; Ueno, Yasuhiro

    2008-03-05

    Adipocere formation is well known as a later post-mortem change. We experienced a female victim who had been sealed up in a clothes box for approximately 4 years. We collected several subcutaneous fats as well as visceral fats from the victim to investigate adipocere formation. Fresh subcutaneous fats of one female and five male victims who suddenly died were used as the control. These samples were homogenized and the lipids were extracted with chloroform and methanol followed by injection into gas chromatography-mass spectrometry and gas chromatography. We detected a hydroxy fatty acid in the fat of the case, but not in the controls. Using standard synthetic hydroxy fatty acid, the lipid extract component was identified as 10-hydroxyoctadecanoic acid (10-OH 18:0) and this concentration was quantified. Consequently we confirmed that adipocere was formed much slowly in dry concealment. In addition, the fatty acid composition was compared with the control. Most of the linoleic acid (18:2) disappeared and a peak developed instead. Using standard synthetic fatty acid, this peak was identified as cis-12-octadecenoic acid (cis-12-18:1). This suggests that linoleic acid is hydrogenated to cis-12-octadecenoic acid in the process of adipocere formation.

  17. Ambulatory blood pressure monitoring during pregnancy with a new, small, easily concealed monitor.

    PubMed

    Tape, T G; Rayburn, W F; Bremer, K D; Schnoor, T A

    1994-12-01

    Before establishing the utility of ambulatory blood pressure monitoring during pregnancy, we evaluated the accuracy of a small, easily concealed monitor. The 59 normotensive pregnant patients were between 13 and 26 gestational weeks. For each monitor reading, two trained observers independently and simultaneously recorded blood pressures using a mercury manometer connected to the monitor cuff. Seven readings in three positions (sitting upright, semirecumbent, standing) were performed on each patient. Averaged differences between the observers' and monitor readings varied from -2.2 to -0.9 mm Hg (systolic) and from -2.8 to -0.6 (fifth-phase diastolic), indicating slight but clinically unimportant overestimation by the monitor. Correlations between averaged observers' readings and the monitor ranged from 0.79 to 0.92 (systolic) and from 0.85 to 0.92 (fifth-phase diastolic). Overall, the observers agreed with the monitor within 5 mm Hg on 94% of systolic readings and 99% of fifth-phase diastolic readings. There was no statistically significant difference in accuracy with changes in body position. We conclude that this small, quiet, noninvasive device accurately determined blood pressures during pregnancy.

  18. Current Research and Potential Applications of the Concealed Information Test: An Overview

    PubMed Central

    Ben-Shakhar, Gershon

    2012-01-01

    Research interest in psychophysiological detection of deception has significantly increased since the September 11 terror attack in the USA. In particular, the concealed information test (CIT), designed to detect memory traces that can connect suspects to a certain crime, has been extensively studied. In this paper I will briefly review several psychophysiological detection paradigms that have been studied, with a focus on the CIT. The theoretical background of the CIT, its strength and weaknesses, its potential applications as well as research finings related to its validity (based on a recent meta-analytic study), will be discussed. Several novel research directions, with a focus on factors that may affect CIT detection in realistic settings (e.g., memory for crime details; the effect of emotional stress during crime execution) will be described. Additionally, research focusing on mal-intentions and attempts to detect terror networks using information gathered from groups of suspects using both the standard CIT and the searching CIT will be reviewed. Finally, implications of current research to the actual application of the CIT will be discussed and several recommendations that can enhance the use of the CIT will be made. PMID:23060826

  19. Living at Risk: Concealing Risk and Preserving Hope in Huntington Disease

    PubMed Central

    Sims, Sharon L.; Swenson, Melinda M.; Harrison, Joan M.; Moskowitz, Carol; Stepanov, Nonna; Suter, Gregory W.; Westphal, Beryl J.

    2013-01-01

    Much of the qualitative research on Huntington disease has focused on the genetic testing aspects of HD. The overall purpose of this qualitative study was to gather information about the everyday experience of living with the risk of developing Huntington disease in a sample of individuals at risk for HD who have chosen not to pursue genetic testing. Data for this article was obtained from unstructured, open-ended qualitative interviews of a sample of people participating in the PHAROS study. PHAROS, the Prospective Huntington At-Risk Observational Study, is a multi-site study that aims to establish whether experienced clinicians can reliably determine the earliest clinical symptoms of Huntington disease in individuals at 50% risk for HD who have chosen not to undergo genetic testing. Interviews were conducted at six PHAROS research sites across the United States. In this paper, the research team used qualitative description to construct and explore two main themes: (1) careful concealment of risk as an act of self-preservation and (2) preserving hope. PMID:17943424

  20. Paternal signature in kin recognition cues of a social insect: concealed in juveniles, revealed in adults.

    PubMed

    Wong, Janine W Y; Meunier, Joël; Lucas, Christophe; Kölliker, Mathias

    2014-10-22

    Kin recognition is a key mechanism to direct social behaviours towards related individuals or avoid inbreeding depression. In insects, recognition is generally mediated by cuticular hydrocarbon (CHC) compounds, which are partly inherited from parents. However, in social insects, potential nepotistic conflicts between group members from different patrilines are predicted to select against the expression of patriline-specific signatures in CHC profiles. Whereas this key prediction in the evolution of insect signalling received empirical support in eusocial insects, it remains unclear whether it can be generalized beyond eusociality to less-derived forms of social life. Here, we addressed this issue by manipulating the number of fathers siring clutches tended by females of the European earwig, Forficula auricularia, analysing the CHC profiles of the resulting juvenile and adult offspring, and using discriminant analysis to estimate the information content of CHC with respect to the maternal and paternal origin of individuals. As predicted, if paternally inherited cues are concealed during family life, increases in mating number had no effect on information content of CHC profiles among earwig juveniles, but significantly decreased the one among adult offspring. We suggest that age-dependent expression of patriline-specific cues evolved to limit the risks of nepotism as family-living juveniles and favour sibling-mating avoidance as group-living adults. These results highlight the role of parental care and social life in the evolution of chemical communication and recognition cues.

  1. Hiding true emotions: micro-expressions in eyes retrospectively concealed by mouth movements

    PubMed Central

    Iwasaki, Miho; Noguchi, Yasuki

    2016-01-01

    When we encounter someone we dislike, we may momentarily display a reflexive disgust expression, only to follow-up with a forced smile and greeting. Our daily lives are replete with a mixture of true and fake expressions. Nevertheless, are these fake expressions really effective at hiding our true emotions? Here we show that brief emotional changes in the eyes (micro-expressions, thought to reflect true emotions) can be successfully concealed by follow-up mouth movements (e.g. a smile). In the same manner as backward masking, mouth movements of a face inhibited conscious detection of all types of micro-expressions in that face, even when viewers paid full attention to the eye region. This masking works only in a backward direction, however, because no disrupting effect was observed when the mouth change preceded the eye change. These results provide scientific evidence for everyday behaviours like smiling to dissemble, and further clarify a major reason for the difficulty we face in discriminating genuine from fake emotional expressions. PMID:26915796

  2. Hiding true emotions: micro-expressions in eyes retrospectively concealed by mouth movements.

    PubMed

    Iwasaki, Miho; Noguchi, Yasuki

    2016-02-26

    When we encounter someone we dislike, we may momentarily display a reflexive disgust expression, only to follow-up with a forced smile and greeting. Our daily lives are replete with a mixture of true and fake expressions. Nevertheless, are these fake expressions really effective at hiding our true emotions? Here we show that brief emotional changes in the eyes (micro-expressions, thought to reflect true emotions) can be successfully concealed by follow-up mouth movements (e.g. a smile). In the same manner as backward masking, mouth movements of a face inhibited conscious detection of all types of micro-expressions in that face, even when viewers paid full attention to the eye region. This masking works only in a backward direction, however, because no disrupting effect was observed when the mouth change preceded the eye change. These results provide scientific evidence for everyday behaviours like smiling to dissemble, and further clarify a major reason for the difficulty we face in discriminating genuine from fake emotional expressions.

  3. Systematic changes in tonic physiological activities during the Concealed Information Test.

    PubMed

    Ogawa, Tokihiro; Matsuda, Izumi; Hirota, Akihisa; Takasawa, Noriyoshi

    2014-12-01

    Many studies on the Concealed Information Test have focused on phasic physiological changes that are temporally locked to stimulus presentation. However, little is known about changes in tonic, basal physiological levels throughout a stimulus series. This study focused on changes in tonic physiological activities during the CIT. Thirty-nine participants carried out a mock theft and subsequently received a CIT. Skin conductance, heart rate, and normalized pulse volume (NPV) were recorded. The pre-stimulus physiological level of these measures throughout the CIT series was compared across a question series with different serial positions of the relevant item. Results showed that changes in the pre-stimulus level differed depending on the serial position of the relevant item. Skin conductance declined throughout the series, but showed a transient increase after relevant item presentation. Heart rate was relatively constant throughout the series, but decreased after relevant item presentation. NPV continued to decrease until the relevant item, but increased thereafter, indicating a pattern similar to the classic Peak of Tension concept. In addition, the pre-stimulus NPV showed a significant relevant-irrelevant difference. Theoretical and practical implications of these findings are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. A new discrimination method for the Concealed Information Test using pretest data and within-individual comparisons.

    PubMed

    Matsuda, Izumi; Hirota, Akihisa; Ogawa, Tokihiro; Takasawa, Noriyoshi; Shigemasu, Kazuo

    2006-08-01

    A latent class discrimination method is proposed for analyzing autonomic responses on the concealed information test. Because there are significant individual differences in autonomic responses, individual response patterns are estimated on the pretest. Then an appropriate discriminant formula for the response pattern of each individual is applied to the CIT test results. The probability that the individual concealed information is calculated by comparing the discriminant formula value of the crime-related item to that of non-crime-related items. The discrimination performance of the latent class discrimination method was higher than those of the logistic regression method and the discriminant analysis method in an experimental demonstration applying the three methods to the same data set.

  5. Being white helps: intersections of self-concealment, stigmatization, identity formation, and psychological distress in racial and sexual minority women.

    PubMed

    McIntyre, Shannon L; Antonucci, Erica A; Haden, Sara C

    2014-01-01

    This study had two objectives: (1) examine the impact of self-concealment on identity formation and on degree of psychological distress and (2) examine the impact of perceived stigma on identity formation and on degree of psychological distress. Analyses were conducted on a diverse sample of 166 women, ages 18-32 (white lesbian, non-white lesbian, white heterosexual, and non-white heterosexual). Findings revealed that self-concealment was positively associated with psychological distress in stigmatized women, but unrelated to psychological distress in the non-stigmatized group. Furthermore, although perceived stigma negatively impacted identity formation in the heterosexual groups, it did not impact either group of lesbians. Finally, non-white heterosexual women's perception of stigma was associated with psychological distress. Implications and specific psychological health disparities between groups are discussed.

  6. Evaluation of active and passive near-millimeter-wave radiometric imaging techniques for detection of concealed objects

    SciTech Connect

    Reber, E.E.; Foote, F.B.; Schellenbaum, R.L.; Bradley, R.G.

    1981-07-01

    Active and passive radiometric imaging techniques have been used at 1.4- and 3-mm wavelengths (220 and 100 GHz) to evaluate their potential use in detecting concealed objects. An evaluation of the techniques includes a particular study of their potential in detecting shielded nuclear materials and explosives carried covertly by personnel. We have previously reported images of metal objects and nuclear shielding materials that were detected when concealed under clothing. These images appear with the human body as background. Detection of contraband by radiometric imaging techniques depends upon the differences in emissivity and reflectivity of the contraband relative to human tissue. Explosives, unlike metals and metal composites, generally have high emissivities and low reflectivities that closely approximate those of human tissue making explosives difficult to detect. Samples of several common types of explosives (TNT, Detasheet, C4, and several types of water gels) have been examined at the 1.4- and 3-mm wavelengths using active and passive radiometric techniques.

  7. Empathy and error processing.

    PubMed

    Larson, Michael J; Fair, Joseph E; Good, Daniel A; Baldwin, Scott A

    2010-05-01

    Recent research suggests a relationship between empathy and error processing. Error processing is an evaluative control function that can be measured using post-error response time slowing and the error-related negativity (ERN) and post-error positivity (Pe) components of the event-related potential (ERP). Thirty healthy participants completed two measures of empathy, the Interpersonal Reactivity Index (IRI) and the Empathy Quotient (EQ), and a modified Stroop task. Post-error slowing was associated with increased empathic personal distress on the IRI. ERN amplitude was related to overall empathy score on the EQ and the fantasy subscale of the IRI. The Pe and measures of empathy were not related. Results remained consistent when negative affect was controlled via partial correlation, with an additional relationship between ERN amplitude and empathic concern on the IRI. Findings support a connection between empathy and error processing mechanisms.

  8. Concealed female external genitals: possible morpho-psychological clue to unique emotional and cognitive evolutionary matrix of man.

    PubMed

    Tosevski, Jovo; Tosevski, Dusica Lecic

    2006-05-01

    Despite genetic similarities between man and other anthropoids, the cognitive abilities of man are distinct. Inaccessible and concealed external female genitals are one of the morphological characteristics distinguishing humans from other higher primates. External female sexual organs in subhuman primates are visible and accessible in the habitual quadrupedal and occasional bipedal posture, whereas these organs in the human female are inaccessible and concealed in any posture. A prospective consequence of gradual bipedalism of hominids during evolution was a shifting of the external female genitals in an anterior direction. In the completely bipedal Homo sapiens, this resulted in the vulvo-cryptic phenomenon, i.e. concealed female genitals in humans. The unique morphology of the human female pelvis served as an obstacle to easy access of the male in the process of copulation, necessitating the female's conscious decision for sexual intercourse. This circumstance might have created a psychological basis for female propellant psychosexual manipulation of the male as a natural consequence. Also, through the process of positive selection it could have formed a basis for linking reproductive success with the development of cognitive and emotional capacities. Female consent to copulation is a conscious and complex act that would be impossible without the involvement of highly developed emotional-cognitive and memoric brain systems. Thus the extraordinary evolutionary strategy might imply a teleological link between concealed female genitals and the emotional-cognitive characteristics of man, creating a permanent promoter of further development of emotional and cognitive brain systems with an impact on all domains of everyday life.

  9. Validity of the Concealed Information Test in realistic mock crime scenarios: comment on Bradley, Malik, and Cullen.

    PubMed

    Gamer, Matthias

    2012-10-01

    Based on the low detection rates of participants who incidentally encoded crime-related details in a realistic mock crime scenario, Bradley, Malik and Cullen (2011) argued that laboratory studies overestimate the validity of the Concealed Information Test. Studies from our group using naturalistic mock crime scenarios, multiple physiological response measures and improved scoring and classification techniques suggest that such a general conclusion is not warranted.

  10. Aircraft system modeling error and control error

    NASA Technical Reports Server (NTRS)

    Kulkarni, Nilesh V. (Inventor); Kaneshige, John T. (Inventor); Krishnakumar, Kalmanje S. (Inventor); Burken, John J. (Inventor)

    2012-01-01

    A method for modeling error-driven adaptive control of an aircraft. Normal aircraft plant dynamics is modeled, using an original plant description in which a controller responds to a tracking error e(k) to drive the component to a normal reference value according to an asymptote curve. Where the system senses that (1) at least one aircraft plant component is experiencing an excursion and (2) the return of this component value toward its reference value is not proceeding according to the expected controller characteristics, neural network (NN) modeling of aircraft plant operation may be changed. However, if (1) is satisfied but the error component is returning toward its reference value according to expected controller characteristics, the NN will continue to model operation of the aircraft plant according to an original description.

  11. [EFFECTIVENESS OF ADVANCED SKIN FLAP AND V-SHAPED VENTRAL INCISION ALONG THE ROOT OF PENILE SHAFT FOR CONCEALED PENIS].

    PubMed

    Lin, Junshan; Li, Dumiao; Zhang, Jianxing; Wu, Qiang; Xu, Yali; Lin, Li

    2015-09-01

    To investigate effectiveness of advanced skin flap and V-shaped ventral incision along the root of penile shaft for concealed penis in children. Between July 2007 and January 2015, 121 boys with concealed penis were treated with advanced skin flap and V-shaped ventral incision along the root of penile shaft. The age varied from 18 months to 13 years (mean, 7.2 years). Repair was based on a vertical incision in median raphe, complete degloving of penis and tacking its base to the dermis of the skin. Advanced skin flap and a V-shaped ventral incision along the root of penile shaft were used to cover the penile shaft. The operation time ranged from 60 to 100 minutes (mean, 75 minutes). Disruption of wound occurred in 1 case, and was cured after dressing change; and primary healing of incision was obtained in the others. The follow-up period ranged from 3 months to 7 years (median, 24 months). All patients achieved good to excellent cosmetic results with a low incidence of complications. The results were satisfactory in exposure of penis and prepuce appearance. No obvious scar was observed. The penis had similar appearance to that after prepuce circumcision. A combination of advanced skin flap and V-shaped ventral incision along the root of penile shaft is a simple, safe, and effective procedure for concealed penis with a similar appearance result to the prepuce circumcision.

  12. Definition of Ensemble Error Statistics for Optimal Ensemble Data Assimilation

    NASA Astrophysics Data System (ADS)

    Frehlich, R.

    2009-09-01

    Next generation data assimilation methods must include the state dependent observation errors, i.e., the spatial and temporal variations produced by the atmospheric turbulent field. A rigorous analysis of optimal data assimilation algorithms and ensemble forecast systems requires a definition of model "truth" or perfect measurement which then defines the total observation error and forecast error. Truth is defined as the spatial average of the continuous atmospheric state variables centered on the model grid locations. To be consistent with the climatology of turbulence, the spatial average is chosen as the effective spatial filter of the numerical model. The observation errors then consist of two independent components: an instrument error and an observation sampling error which describes the mismatch of the spatial average of the observation and the spatial average of the perfect measurement or "truth". The observation sampling error is related to the "error of representativeness" but is defined only in terms of the local statistics of the atmosphere and the sampling pattern of the observation. Optimal data assimilation requires an estimate of the local background error correlation as well as the local observation error correlation. Both of these local correlations can be estimated from ensemble assimilation techniques where each member of the ensemble are produced by generating and assimilating random observations consistent with the estimates of the local sampling errors based on estimates of the local turbulent statistics. A rigorous evaluation of these optimal ensemble data assimilation techniques requires a definition of the ensemble members and the ensemble average that describes the error correlations. A new formulation is presented that is consistent with the climatology of atmospheric turbulence and the implications of this formulation for ensemble forecast systems is discussed.

  13. The Invisible Work of Closeting: A Qualitative Study About Strategies Used by Lesbian and Gay Persons to Conceal Their Sexual Orientation.

    PubMed

    Malterud, Kirsti; Bjorkman, Mari

    2016-10-01

    The last decades have offered substantial improvement regarding human rights for lesbian and gay (LG) persons. Yet LG persons are often in the closet, concealing their sexual orientation. We present a qualitative study based on 182 histories submitted from 161 LG individuals to a Web site. The aim was to explore experiences of closeting among LG persons in Norway. A broad range of strategies was used for closeting, even among individuals who generally considered themselves to be out of the closet. Concealment was enacted by blunt denial, clever avoidance, or subtle vagueness. Other strategies included changing or eliminating the pronoun or name of the partner in ongoing conversations. Context-dependent concealment, differentiating between persons, situations, or arenas, was repeatedly applied for security or convenience. We propose a shift from "being in the closet" to "situated concealment of sexual orientation."

  14. Error thresholds for RNA replication in the presence of both point mutations and premature termination errors.

    PubMed

    Tupper, Andrew S; Higgs, Paul G

    2017-09-07

    We consider a spatial model of replication in the RNA World in which polymerase ribozymes use neighbouring strands as templates. Point mutation errors create parasites that have the same replication rate as the polymerase. We have shown previously that spatial clustering allows survival of the polymerases as long as the error rate is below a critical error threshold. Here, we additionally consider errors where a polymerase prematurely terminates replication before reaching the end of the template, creating shorter parasites that are replicated faster than the functional polymerase. In well-known experiments where Qβ RNA is replicated by an RNA polymerase protein, the virus RNA is rapidly replaced by very short non-functional sequences. If the same thing were to occur when the polymerase is a ribozyme, this would mean that termination errors could potentially destroy the RNA World. In this paper, we show that this is not the case in the RNA replication model studied here. When there is continued generation of parasites of all lengths by termination errors, the system can survive up to a finite error threshold, due to the formation of travelling wave patterns; hence termination errors are important, but they do not lead to the inevitable destruction of the RNA World by short parasites. The simplest assumption is that parasite replication rate is inversely proportional to the strand length. In this worst-case scenario, the error threshold for termination errors is much lower than for point mutations. We also consider a more realistic model in which the time for replication of a strand is the sum of a time for binding of the polymerase, and a time for polymerization. When the binding step is considered, termination errors are less serious than in the worst case. In the limit where the binding time is dominant, replication rates are equal for all lengths, and the error threshold for termination is the same as for point mutations. Copyright © 2017 Elsevier Ltd. All

  15. GCF HSD error control

    NASA Technical Reports Server (NTRS)

    Hung, C. K.

    1978-01-01

    A selective repeat automatic repeat request (ARQ) system was implemented under software control in the Ground Communications Facility error detection and correction (EDC) assembly at JPL and the comm monitor and formatter (CMF) assembly at the DSSs. The CMF and EDC significantly improved real time data quality and significantly reduced the post-pass time required for replay of blocks originally received in error. Since the remote mission operation centers (RMOCs) do not provide compatible error correction equipment, error correction will not be used on the RMOC-JPL high speed data (HSD) circuits. The real time error correction capability will correct error burst or outage of two loop-times or less for each DSS-JPL HSD circuit.

  16. Software error detection

    NASA Technical Reports Server (NTRS)

    Buechler, W.; Tucker, A. G.

    1981-01-01

    Several methods were employed to detect both the occurrence and source of errors in the operational software of the AN/SLQ-32. A large embedded real time electronic warfare command and control system for the ROLM 1606 computer are presented. The ROLM computer provides information about invalid addressing, improper use of privileged instructions, stack overflows, and unimplemented instructions. Additionally, software techniques were developed to detect invalid jumps, indices out of range, infinte loops, stack underflows, and field size errors. Finally, data are saved to provide information about the status of the system when an error is detected. This information includes I/O buffers, interrupt counts, stack contents, and recently passed locations. The various errors detected, techniques to assist in debugging problems, and segment simulation on a nontarget computer are discussed. These error detection techniques were a major factor in the success of finding the primary cause of error in 98% of over 500 system dumps.

  17. Error detection method

    DOEpatents

    Olson, Eric J.

    2013-06-11

    An apparatus, program product, and method that run an algorithm on a hardware based processor, generate a hardware error as a result of running the algorithm, generate an algorithm output for the algorithm, compare the algorithm output to another output for the algorithm, and detect the hardware error from the comparison. The algorithm is designed to cause the hardware based processor to heat to a degree that increases the likelihood of hardware errors to manifest, and the hardware error is observable in the algorithm output. As such, electronic components may be sufficiently heated and/or sufficiently stressed to create better conditions for generating hardware errors, and the output of the algorithm may be compared at the end of the run to detect a hardware error that occurred anywhere during the run that may otherwise not be detected by traditional methodologies (e.g., due to cooling, insufficient heat and/or stress, etc.).

  18. Model Error Budgets

    NASA Technical Reports Server (NTRS)

    Briggs, Hugh C.

    2008-01-01

    An error budget is a commonly used tool in design of complex aerospace systems. It represents system performance requirements in terms of allowable errors and flows these down through a hierarchical structure to lower assemblies and components. The requirements may simply be 'allocated' based upon heuristics or experience, or they may be designed through use of physics-based models. This paper presents a basis for developing an error budget for models of the system, as opposed to the system itself. The need for model error budgets arises when system models are a principle design agent as is increasingly more common for poorly testable high performance space systems.

  19. Error coding simulations

    NASA Technical Reports Server (NTRS)

    Noble, Viveca K.

    1993-01-01

    There are various elements such as radio frequency interference (RFI) which may induce errors in data being transmitted via a satellite communication link. When a transmission is affected by interference or other error-causing elements, the transmitted data becomes indecipherable. It becomes necessary to implement techniques to recover from these disturbances. The objective of this research is to develop software which simulates error control circuits and evaluate the performance of these modules in various bit error rate environments. The results of the evaluation provide the engineer with information which helps determine the optimal error control scheme. The Consultative Committee for Space Data Systems (CCSDS) recommends the use of Reed-Solomon (RS) and convolutional encoders and Viterbi and RS decoders for error correction. The use of forward error correction techniques greatly reduces the received signal to noise needed for a certain desired bit error rate. The use of concatenated coding, e.g. inner convolutional code and outer RS code, provides even greater coding gain. The 16-bit cyclic redundancy check (CRC) code is recommended by CCSDS for error detection.

  20. Model Error Budgets

    NASA Technical Reports Server (NTRS)

    Briggs, Hugh C.

    2008-01-01

    An error budget is a commonly used tool in design of complex aerospace systems. It represents system performance requirements in terms of allowable errors and flows these down through a hierarchical structure to lower assemblies and components. The requirements may simply be 'allocated' based upon heuristics or experience, or they may be designed through use of physics-based models. This paper presents a basis for developing an error budget for models of the system, as opposed to the system itself. The need for model error budgets arises when system models are a principle design agent as is increasingly more common for poorly testable high performance space systems.

  1. Post-Error Adjustments

    PubMed Central

    Danielmeier, Claudia; Ullsperger, Markus

    2011-01-01

    When our brain detects an error, this process changes how we react on ensuing trials. People show post-error adaptations, potentially to improve their performance in the near future. At least three types of behavioral post-error adjustments have been observed. These are post-error slowing (PES), post-error reduction of interference, and post-error improvement in accuracy (PIA). Apart from these behavioral changes, post-error adaptations have also been observed on a neuronal level with functional magnetic resonance imaging and electroencephalography. Neuronal post-error adaptations comprise activity increase in task-relevant brain areas, activity decrease in distracter-encoding brain areas, activity modulations in the motor system, and mid-frontal theta power increases. Here, we review the current literature with respect to these post-error adjustments, discuss under which circumstances these adjustments can be observed, and whether the different types of adjustments are linked to each other. We also evaluate different approaches for explaining the functional role of PES. In addition, we report reanalyzed and follow-up data from a flanker task and a moving dots interference task showing (1) that PES and PIA are not necessarily correlated, (2) that PES depends on the response–stimulus interval, and (3) that PES is reliable on a within-subject level over periods as long as several months. PMID:21954390

  2. Concealed d-wave pairs in the s± condensate of iron-based superconductors.

    PubMed

    Ong, Tzen; Coleman, Piers; Schmalian, Jörg

    2016-05-17

    A central question in iron-based superconductivity is the mechanism by which the paired electrons minimize their strong mutual Coulomb repulsion. In most unconventional superconductors, Coulomb repulsion is minimized through the formation of higher angular momentum Cooper pairs, with Fermi surface nodes in the pair wavefunction. The apparent absence of such nodes in the iron-based superconductors has led to a belief they form an s-wave ([Formula: see text]) singlet state, which changes sign between the electron and hole pockets. However, the multiorbital nature of these systems opens an alternative possibility. Here, we propose a new class of [Formula: see text] state containing a condensate of d-wave Cooper pairs, concealed by their entanglement with the iron orbitals. By combining the d-wave ([Formula: see text]) motion of the pairs with the internal angular momenta [Formula: see text] of the iron orbitals to make a singlet ([Formula: see text]), an [Formula: see text] superconductor with a nontrivial topology is formed. This scenario allows us to understand the development of octet nodes in potassium-doped Ba1-x KXFe2As2 as a reconfiguration of the orbital and internal angular momentum into a high spin ([Formula: see text]) state; the reverse transition under pressure into a fully gapped state can then be interpreted as a return to the low-spin singlet. The formation of orbitally entangled pairs is predicted to give rise to a shift in the orbital content at the Fermi surface, which can be tested via laser-based angle-resolved photoemission spectroscopy.

  3. Detection of concealed cars in complex cargo X-ray imagery using Deep Learning.

    PubMed

    Jaccard, Nicolas; Rogers, Thomas W; Morton, Edward J; Griffin, Lewis D

    2017-01-01

    Non-intrusive inspection systems based on X-ray radiography techniques are routinely used at transport hubs to ensure the conformity of cargo content with the supplied shipping manifest. As trade volumes increase and regulations become more stringent, manual inspection by trained operators is less and less viable due to low throughput. Machine vision techniques can assist operators in their task by automating parts of the inspection workflow. Since cars are routinely involved in trafficking, export fraud, and tax evasion schemes, they represent an attractive target for automated detection and flagging for subsequent inspection by operators. Development and evaluation of a novel method for the automated detection of cars in complex X-ray cargo imagery. X-ray cargo images from a stream-of-commerce dataset were classified using a window-based scheme. The limited number of car images was addressed by using an oversampling scheme. Different Convolutional Neural Network (CNN) architectures were compared with well-established bag of words approaches. In addition, robustness to concealment was evaluated by projection of objects into car images. CNN approaches outperformed all other methods evaluated, achieving 100% car image classification rate for a false positive rate of 1-in-454. Cars that were partially or completely obscured by other goods, a modus operandi frequently adopted by criminals, were correctly detected. We believe that this level of performance suggests that the method is suitable for deployment in the field. It is expected that the generic object detection workflow described can be extended to other object classes given the availability of suitable training data.

  4. Subclinical vitamin D deficiency is increased in adolescent girls who wear concealing clothing.

    PubMed

    Hatun, Sukru; Islam, Omer; Cizmecioglu, Filiz; Kara, Bulent; Babaoglu, Kadir; Berk, Fatma; Gökalp, Ayse Sevim

    2005-02-01

    Vitamin D deficiency continues to be a worldwide problem, especially in developing countries. The aim of this study was to investigate potential risk factors for vitamin D deficiency. Girls (n = 89) aged 13 to 17 y were enrolled in the study. Study subjects were stratified into 3 groups: Group I included girls living in a suburban area; Group II girls lived in an urban area, and Group III girls lived in an urban area and wore concealing clothes for religious reasons. At the end of winter (in April) serum 25-hydroxyvitamin D [25(OH)D] levels were measured and dietary data were collected using questionnaires. Vitamin D deficiency was defined as a serum 25(OH)D concentration < 25 nmol/L, and insufficiency as a 25(OH)D concentration between 25 and 50 nmol/L. The lumbar and femur neck bone mineral densities (BMD) were measured using dual X-ray absorptiometry (DEXA). Overall, 39 girls (43.8%) had vitamin D insufficiency and 19 (21.3%) had vitamin D deficiency. In group III (wearing covered dress) the serum 25(OH)D concentrations (28.13 +/- 12.53 nmol/L) were significantly lower than in the other 2 groups, and within this group, 50% of girls were vitamin D deficient. The lumbar and femur neck BMD of girls with lower 25(OH)D levels did not differ from those with adequate vitamin D levels. We conclude that vitamin D deficiency is an important problem in Turkish adolescent girls, especially in those who follow a religious dress code; therefore, vitamin D supplementation appears to be necessary for adolescent girls.

  5. Design of spectrally versatile forward-looking ground-penetrating radar for detection of concealed targets

    NASA Astrophysics Data System (ADS)

    Phelan, Brian R.; Ressler, Marc A.; Mazzaro, Gregory J.; Sherbondy, Kelly D.; Narayanan, Ram M.

    2013-05-01

    The design of high-resolution radars which can operate in theater involves a careful consideration of the radar's radiated spectrum. While a wide bandwidth yields better target detectability and classification, it can also interfere with other devices and/or violate federal and international communication laws. Under the Army Research Laboratory (ARL) Partnerships in Research Transition (PIRT) program, we are developing a Stepped-Frequency Radar (SFR) which allows for manipulation of the radiated spectrum, while still maintaining an effective ultra-wide bandwidth for achieving good range resolution. The SFR is a forward-looking, ultra-wideband (UWB) imaging radar capable of detecting concealed targets. This paper presents the research and analysis undertaken during the design of the SFR which will eventually complement an existing ARL system, the Synchronous Impulse REconstruction (SIRE) radar. The SFR is capable of excising prohibited frequency bands, while maintaining the down-range resolution capability of the original SIRE radar. The SFR has two transmit antennas and a 16-element receive antenna array, and this configuration achieves suitable cross-range resolution for target detection. The SFR, like the SIRE radar, is a vehicle mounted, forward-looking, ground penetrating radar (GPR) capable of using synthetic aperture radar (SAR) technology for the detection of subsurface targets via 3D imaging. Many contradicting design considerations are analyzed in this paper. The selection of system bandwidth, antenna types, number of antennas, frequency synthesizers, digitizers, receive amplifiers, wideband splitters, and many other components are critical to the design of the SFR. Leveraging commercial components and SIRE sub-systems were design factors offering an expedited time to the initial implementation of the radar while reducing overall costs. This SFR design will result in an ARL asset to support obscured target detection such as improvised explosive devices

  6. Identification of Concealed and Manifest Long QT Syndrome Using a Novel T Wave Analysis Program.

    PubMed

    Sugrue, Alan; Noseworthy, Peter A; Kremen, Vaclav; Bos, J Martijn; Qiang, Bo; Rohatgi, Ram K; Sapir, Yehu; Attia, Zachi I; Brady, Peter; Asirvatham, Samuel J; Friedman, Paul A; Ackerman, Michael J

    2016-07-01

    Congenital long QT syndrome (LQTS) is characterized by QT prolongation. However, the QT interval itself is insufficient for diagnosis, unless the corrected QT interval is repeatedly ≥500 ms without an acquired explanation. Further, the majority of LQTS patients have a corrected QT interval below this threshold, and a significant minority has normal resting corrected QT interval values. Here, we aimed to develop and validate a novel, quantitative T wave morphological analysis program to differentiate LQTS patients from healthy controls. We analyzed a genotyped cohort of 420 patients (22±16 years, 43% male) with either LQT1 (61%) or LQT2 (39%). ECG analysis was conducted using a novel, proprietary T wave analysis program that quantitates subtle changes in T wave morphology. The top 3 discriminating features in each ECG lead were determined and the lead with the best discrimination selected. Classification was performed using a linear discriminant classifier and validated on an untouched cohort. The top 3 features were Tpeak-Tend interval, T wave left slope, and T wave center of gravity x axis (last 25% of the T wave). Lead V6 had the best discrimination. It could distinguish 86.8% of LQTS patients from healthy controls. Moreover, it distinguished 83.33% of patients with concealed LQTS from controls, despite having essentially identical resting corrected QT interval values. T wave quantitative analysis on the 12-lead surface ECG provides an effective, novel tool to distinguish patients with either LQT1/LQT2 from healthy matched controls. It can provide guidance while mutation-specific genetic testing is in motion for family members. © 2016 American Heart Association, Inc.

  7. Nodal recovery, dual pathway physiology, and concealed conduction determine complex AV dynamics in human atrial tachyarrhythmias.

    PubMed

    Masè, Michela; Glass, Leon; Disertori, Marcello; Ravelli, Flavia

    2012-11-15

    The genesis of complex ventricular rhythms during atrial tachyarrhythmias in humans is not fully understood. To clarify the dynamics of atrioventricular (AV) conduction in response to a regular high-rate atrial activation, 29 episodes of spontaneous or pacing-induced atrial flutter (AFL), covering a wide range of atrial rates (cycle lengths from 145 to 270 ms), were analyzed in 10 patients. AV patterns were identified by applying firing sequence and surrogate data analysis to atrial and ventricular activation series, whereas modular simulation with a difference-equation AV node model was used to correlate the patterns with specific nodal properties. AV node response at high atrial rate was characterized by 1) AV patterns of decreasing conduction ratios at the shortening of atrial cycle length (from 236.3 ± 32.4 to 172.6 ± 17.8 ms) according to a Farey sequence ordering (conduction ratio from 0.34 ± 0.12 to 0.23 ± 0.06; P < 0.01); 2) the appearance of high-order alternating Wenckebach rhythms, such as 6:2, 10:2, and 12:2, associated with ventricular interval oscillations of large amplitude (407.7 ± 150.4 ms); and 3) the deterioration of pattern stability at advanced levels of block, with the percentage of stable patterns decreasing from 64.3 ± 35.2% to 28.3 ± 34.5% (P < 0.01). Simulations suggested these patterns to originate from the combined effect of nodal recovery, dual pathway physiology, and concealed conduction. These results indicate that intrinsic nodal properties may account for the wide spectrum of AV block patterns occurring during regular atrial tachyarrhythmias. The characterization of AV nodal function during different AFL forms constitutes an intermediate step toward the understanding of complex ventricular rhythms during atrial fibrillation.

  8. Concealed d-wave pairs in the s± condensate of iron-based superconductors

    PubMed Central

    Ong, Tzen; Coleman, Piers; Schmalian, Jörg

    2016-01-01

    A central question in iron-based superconductivity is the mechanism by which the paired electrons minimize their strong mutual Coulomb repulsion. In most unconventional superconductors, Coulomb repulsion is minimized through the formation of higher angular momentum Cooper pairs, with Fermi surface nodes in the pair wavefunction. The apparent absence of such nodes in the iron-based superconductors has led to a belief they form an s-wave (s±) singlet state, which changes sign between the electron and hole pockets. However, the multiorbital nature of these systems opens an alternative possibility. Here, we propose a new class of s± state containing a condensate of d-wave Cooper pairs, concealed by their entanglement with the iron orbitals. By combining the d-wave (L=2) motion of the pairs with the internal angular momenta I=2 of the iron orbitals to make a singlet (J=L+I=0), an s± superconductor with a nontrivial topology is formed. This scenario allows us to understand the development of octet nodes in potassium-doped Ba1−x KXFe2As2 as a reconfiguration of the orbital and internal angular momentum into a high spin (J=L+I=4) state; the reverse transition under pressure into a fully gapped state can then be interpreted as a return to the low-spin singlet. The formation of orbitally entangled pairs is predicted to give rise to a shift in the orbital content at the Fermi surface, which can be tested via laser-based angle-resolved photoemission spectroscopy. PMID:27140626

  9. Concealed d -wave pairs in the s ± condensate of iron-based superconductors

    DOE PAGES

    Ong, Tzen; Coleman, Piers; Schmalian, Jörg

    2016-05-02

    A central question in iron-based superconductivity is the mechanism by which the paired electrons minimize their strong mutual Coulomb repulsion. In most unconventional superconductors, Coulomb repulsion is minimized through the formation of higher angular momentum Cooper pairs, with Fermi surface nodes in the pair wavefunction. The apparent absence of such nodes in the iron-based superconductors has led to a belief they form an s-wave (s±) singlet state, which changes sign between the electron and hole pockets. However, the multiorbital nature of these systems opens an alternative possibility. In this paper, we propose a new class of s± state containing amore » condensate of d-wave Cooper pairs, concealed by their entanglement with the iron orbitals. By combining the d-wave (L=2) motion of the pairs with the internal angular momenta I =2 of the iron orbitals to make a singlet (J =L+I =0), an s± superconductor with a nontrivial topology is formed. This scenario allows us to understand the development of octet nodes in potassium-doped Ba1$-$xKXFe2As2 as a reconfiguration of the orbital and internal angular momentum into a high spin (J =L+I =4) state; the reverse transition under pressure into a fully gapped state can then be interpreted as a return to the low-spin singlet. Finally, the formation of orbitally entangled pairs is predicted to give rise to a shift in the orbital content at the Fermi surface, which can be tested via laser-based angle-resolved photoemission spectroscopy.« less

  10. Spatial abstraction for autonomous robot navigation.

    PubMed

    Epstein, Susan L; Aroor, Anoop; Evanusa, Matthew; Sklar, Elizabeth I; Parsons, Simon

    2015-09-01

    Optimal navigation for a simulated robot relies on a detailed map and explicit path planning, an approach problematic for real-world robots that are subject to noise and error. This paper reports on autonomous robots that rely on local spatial perception, learning, and commonsense rationales instead. Despite realistic actuator error, learned spatial abstractions form a model that supports effective travel.

  11. Error analysis of compensation cutting technique for wavefront error of KH2PO4 crystal.

    PubMed

    Tie, Guipeng; Dai, Yifan; Guan, Chaoliang; Zhu, Dengchao; Song, Bing

    2013-09-20

    Considering the wavefront error of KH(2)PO(4) (KDP) crystal is difficult to control through face fly cutting process because of surface shape deformation during vacuum suction, an error compensation technique based on a spiral turning method is put forward. An in situ measurement device is applied to measure the deformed surface shape after vacuum suction, and the initial surface figure error, which is obtained off-line, is added to the in situ surface shape to obtain the final surface figure to be compensated. Then a three-axis servo technique is utilized to cut the final surface shape. In traditional cutting processes, in addition to common error sources such as the error in the straightness of guide ways, spindle rotation error, and error caused by ambient environment variance, three other errors, the in situ measurement error, position deviation error, and servo-following error, are the main sources affecting compensation accuracy. This paper discusses the effect of these three errors on compensation accuracy and provides strategies to improve the final surface quality. Experimental verification was carried out on one piece of KDP crystal with the size of Φ270 mm×11 mm. After one compensation process, the peak-to-valley value of the transmitted wavefront error dropped from 1.9λ (λ=632.8 nm) to approximately 1/3λ, and the mid-spatial-frequency error does not become worse when the frequency of the cutting tool trajectory is controlled by use of a low-pass filter.

  12. Twenty Questions about Student Errors.

    ERIC Educational Resources Information Center

    Fisher, Kathleen M.; Lipson, Joseph Isaac

    1986-01-01

    Discusses the value of studying errors made by students in the process of learning science. Addresses 20 research questions dealing with student learning errors. Attempts to characterize errors made by students and clarify some terms used in error research. (TW)

  13. Action errors, error management, and learning in organizations.

    PubMed

    Frese, Michael; Keith, Nina

    2015-01-03

    Every organization is confronted with errors. Most errors are corrected easily, but some may lead to negative consequences. Organizations often focus on error prevention as a single strategy for dealing with errors. Our review suggests that error prevention needs to be supplemented by error management--an approach directed at effectively dealing with errors after they have occurred, with the goal of minimizing negative and maximizing positive error consequences (examples of the latter are learning and innovations). After defining errors and related concepts, we review research on error-related processes affected by error management (error detection, damage control). Empirical evidence on positive effects of error management in individuals and organizations is then discussed, along with emotional, motivational, cognitive, and behavioral pathways of these effects. Learning from errors is central, but like other positive consequences, learning occurs under certain circumstances--one being the development of a mind-set of acceptance of human error.

  14. Everyday Scale Errors

    ERIC Educational Resources Information Center

    Ware, Elizabeth A.; Uttal, David H.; DeLoache, Judy S.

    2010-01-01

    Young children occasionally make "scale errors"--they attempt to fit their bodies into extremely small objects or attempt to fit a larger object into another, tiny, object. For example, a child might try to sit in a dollhouse-sized chair or try to stuff a large doll into it. Scale error research was originally motivated by parents' and…

  15. Refractive error blindness.

    PubMed Central

    Dandona, R.; Dandona, L.

    2001-01-01

    Recent data suggest that a large number of people are blind in different parts of the world due to high refractive error because they are not using appropriate refractive correction. Refractive error as a cause of blindness has been recognized only recently with the increasing use of presenting visual acuity for defining blindness. In addition to blindness due to naturally occurring high refractive error, inadequate refractive correction of aphakia after cataract surgery is also a significant cause of blindness in developing countries. Blindness due to refractive error in any population suggests that eye care services in general in that population are inadequate since treatment of refractive error is perhaps the simplest and most effective form of eye care. Strategies such as vision screening programmes need to be implemented on a large scale to detect individuals suffering from refractive error blindness. Sufficient numbers of personnel to perform reasonable quality refraction need to be trained in developing countries. Also adequate infrastructure has to be developed in underserved areas of the world to facilitate the logistics of providing affordable reasonable-quality spectacles to individuals suffering from refractive error blindness. Long-term success in reducing refractive error blindness worldwide will require attention to these issues within the context of comprehensive approaches to reduce all causes of avoidable blindness. PMID:11285669

  16. Teacher-Induced Errors.

    ERIC Educational Resources Information Center

    Richmond, Kent C.

    Students of English as a second language (ESL) often come to the classroom with little or no experience in writing in any language and with inaccurate assumptions about writing. Rather than correct these assumptions, teachers often seem to unwittingly reinforce them, actually inducing errors into their students' work. Teacher-induced errors occur…

  17. Learning from Errors

    ERIC Educational Resources Information Center

    Metcalfe, Janet

    2017-01-01

    Although error avoidance during learning appears to be the rule in American classrooms, laboratory studies suggest that it may be a counterproductive strategy, at least for neurologically typical students. Experimental investigations indicate that errorful learning followed by corrective feedback is beneficial to learning. Interestingly, the…

  18. Uncorrected refractive errors

    PubMed Central

    Naidoo, Kovin S; Jaggernath, Jyoti

    2012-01-01

    Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC), were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR) Development, Service Development and Social Entrepreneurship. PMID:22944755

  19. System contributions to error.

    PubMed

    Adams, J G; Bohan, J S

    2000-11-01

    An unacceptably high rate of medical error occurs in the emergency department (ED). Professional accountability requires that EDs be managed to systematically eliminate error. This requires advocacy and leadership at every level of the specialty and at each institution in order to be effective and sustainable. At the same time, the significant operational challenges that face the ED, such as excessive patient care requirements, should be recognized if error reduction efforts are to remain credible. Proper staffing levels, for example, are an important prerequisite if medical error is to be minimized. Even at times of low volume, however, medical error is probably common. Engineering human factors and operational procedures, promoting team coordination, and standardizing care processes can decrease error and are strongly promoted. Such efforts should be coupled to systematic analysis of errors that occur. Reliable reporting is likely only if the system is based within the specialty to help ensure proper analysis and decrease threat. Ultimate success will require dedicated effort, continued advocacy, and promotion of research.

  20. Uncorrected refractive errors.

    PubMed

    Naidoo, Kovin S; Jaggernath, Jyoti

    2012-01-01

    Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC), were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR) Development, Service Development and Social Entrepreneurship.