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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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).

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  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. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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).

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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…

  9. [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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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)…

  19. 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…

  20. 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.

  1. 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…

  2. 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.

  3. 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…

  4. 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

  5. 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.

  6. 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.

  7. 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... 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...

  8. 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... 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...

  9. 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... 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...

  10. 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... 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...

  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...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. [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.

  17. 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

  18. 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

  19. Measurement of surface form error of an optical surface with reduced interferometric spatial coherence artifacts using a ring source and polarization phase-shifting interferometry.

    PubMed

    Pavan Kumar, Y; Negi, Sarvendra Singh; Kamath, M Pandurang; Chatterjee, Sanjib; Sharma, S D

    2016-12-10

    We present a technique for the measurement of surface form error of an optical surface using a ring source and polarization phase-shifting interferometry (PPSI). The ring source, generated using a refracting axicon, is projected onto a rotating diffuser to reduce the spatial coherence noise generated by the spatially coherent He-Ne laser and to enhance the interference fringe contrast. PPSI is applied to extract the phase [and hence the optical path difference (OPD)] from the interference fringes formed by a Fizeau cavity using the ring source. The OPD values are least-square fitted to a plane and the surface form errors are evaluated from the deviations of the OPD values from the fitted reference plane. A two-step subtraction method to reduce the system errors and the effect of the ring source diameter on the effective measurement area of the test surface are discussed. The main advantage of the technique is that the perturbations in the Fizeau cavity are negligible during the phase shifts as the phase shifts between the interfering beams are introduced outside the cavity.

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. 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.

  15. 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…

  16. 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.

  17. 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.

  18. 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.

  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. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  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. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. The nitrogen camera and the detection of concealed explosives

    NASA Astrophysics Data System (ADS)

    Trower, W. P.

    1993-06-01

    The nitrogen camera is an instrument based on a nuclear technique which is capable of imaging nitrogen concentrations with surface densities and amounts typical of currently concealed conventional explosives. Its signal is the totality of high-energy gamma rays detected in the multiscalar mode after the irradiation of a target pixel by a beam from a 50 MeV electron racetrack microtron. The sole interfering signal, from 13C, can be disentangled by two methods. Images of 180 2 × 2 cm 2 pixels, which are shown, eventually will be produced in ˜ 7.2 s. Progress towards an operational nitrogen camera is discussed.

  13. 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

  14. [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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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...

  8. 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...

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

  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. 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.

  1. 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.

  2. 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…

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. [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

  8. 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

  9. Medication Errors

    MedlinePlus

    ... common links HHS U.S. Department of Health and Human Services U.S. Food and Drug Administration A to Z Index Follow ... Practices National Patient Safety Foundation To Err is Human: ... Errors: Quality Chasm Series National Coordinating Council for Medication Error ...

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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")…

  7. 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…

  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. 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…

  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. 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.

  12. 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…

  13. 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…

  14. 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…

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. [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.

  5. 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.

  6. Hydrogeological Studies to Identify the Trend of Concealed Section of the North Tabriz Fault (Iran).

    PubMed

    Rajabpour, Hossein; Vaezihir, Abdorreza

    2016-10-17

    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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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

  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. 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.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. [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.

  6. 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.

  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. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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)…

  5. 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.

  6. 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.

  7. 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

  8. 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.

  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. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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…

  19. 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.

  20. 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

  1. 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.…

  2. 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.

  3. 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.

  4. 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.

  5. 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 ...

  6. 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…

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. [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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  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. 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."

  9. 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.

  10. 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.

  11. 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.).

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  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. 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.

  1. 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.

  2. 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)

  3. 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.

  4. 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

  5. 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…

  6. Noninvasive, quantitative analysis of drug mixtures in containers using spatially offset Raman spectroscopy (SORS) and multivariate statistical analysis.

    PubMed

    Olds, William J; Sundarajoo, Shankaran; Selby, Mark; Cletus, Biju; Fredericks, Peter M; Izake, Emad L

    2012-05-01

    In this paper, spatially offset Raman spectroscopy (SORS) is demonstrated for noninvasively investigating the composition of drug mixtures inside an opaque plastic container. The mixtures consisted of three components including a target drug (acetaminophen or phenylephrine hydrochloride) and two diluents (glucose and caffeine). The target drug concentrations ranged from 5% to 100%. After conducting SORS analysis to ascertain the Raman spectra of the concealed mixtures, principal component analysis (PCA) was performed on the SORS spectra to reveal trends within the data. Partial least squares (PLS) regression was used to construct models that predicted the concentration of each target drug, in the presence of the other two diluents. The PLS models were able to predict the concentration of acetaminophen in the validation samples with a root-mean-square error of prediction (RMSEP) of 3.8% and the concentration of phenylephrine hydrochloride with an RMSEP of 4.6%. This work demonstrates the potential of SORS, used in conjunction with multivariate statistical techniques, to perform noninvasive, quantitative analysis on mixtures inside opaque containers. This has applications for pharmaceutical analysis, such as monitoring the degradation of pharmaceutical products on the shelf, in forensic investigations of counterfeit drugs, and for the analysis of illicit drug mixtures which may contain multiple components.

  7. 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.

  8. An Efficient Shared Adaptive Packet Loss Concealment Scheme through 1-Port Gateway System for Internet Telephony Service

    NASA Astrophysics Data System (ADS)

    Kim, Jinsul; Lee, Hyunwoo; Ryu, Won; Lee, Byungsun; Hahn, Minsoo

    In this letter, we propose a shared adaptive packet loss concealment scheme for the high quality guaranteed Internet telephony service which connects multiple users. In order to recover packet loss efficiently in the all-IP based convergence environment, we provide a robust signal recovery scheme which is based on the shared adaptive both-side information utilization. This scheme is provided according to the average magnitude variation across the frames and the pitch period replication on the 1-port gateway (G/W) system. The simulated performance demonstrates that the proposed scheme has the advantages of low processing times and high recovery rates in the all-IP based ubiquitous environment.

  9. Using pretest data to screen low-reactivity individuals in the autonomic-based concealed information test.

    PubMed

    Matsuda, Izumi; Ogawa, Tokihiro; Tsuneoka, Michiko; Verschuere, Bruno

    2015-03-01

    The concealed information test (CIT) can be used to assess whether an individual possesses crime-related information. However, its discrimination performance has room for improvement. We examined whether screening out participants who do not respond distinctively on a pretest improves the diagnosticity of a mock-crime CIT. Before conducting the CIT, we gave a pretest to 152 participants, 80 of whom were assigned as guilty. Pretest screening significantly improved the diagnostic value of the mock-crime CIT; however, it also led to a substantial number of undiagnosed participants (33.6%). Pretest screening holds promise, but its application would benefit from dedicated measures for screening out participants.

  10. Imaging the concealed section of the Whakatane fault below Whakatane city, New Zealand, with a shear wave land streamer system

    NASA Astrophysics Data System (ADS)

    Polom, Ulrich; Mueller, Christof; Krawczyk, CharLotte M.

    2016-04-01

    The Mw 7.1 Darfield Earthquake in September 2010 ruptured the surface along the Greendale Fault that was not known prior to the earthquake. The subsequent Mw 6.3 Christchurch earthquake in February 2011 demonstrated that concealed active faults have a significant risk potential for urban infrastructure and human life in New Zealand if they are located beneath or close to such areas. Mapping exposures and analysis of active faults incorporated into the National Seismic Hazard Model (NSHM) suggests that several thousands of these active structures are yet to be identified and have the potential to generate moderate to large magnitude earthquakes (i.e. magnitudes >5). Geological mapping suggests that active faults pass beneath, or within many urban areas in New Zealand, including Auckland, Blenheim, Christchurch, Hastings/Napier, Nelson, Rotorua, Taupo, Wellington, and Whakatane. Since no established methodology for routinely locating and assessing the earthquake hazard posed by concealed active faults is available, the principal objective of the presented study was to evaluate the usefulness of high-resolution shear wave seismic reflection profiling using a land streamer to locate buried faults in urban areas of New Zealand. During the survey carried out in the city of Whakatane in February 2015, the method was first tested over a well known surface outcrop of the Edgecumbe Fault 30 km south-west of Whakatane city. This allowed further to investigate the principle shear wave propagation characteristics in the unknown sediments, consisting mainly of effusive rock material of the Taupo volcanic zone mixed with marine transgression units. Subsequently the survey was continued within Whakatane city using night operation time slots to reduce the urban noise. In total, 11 profiles of 5.7 km length in high data quality were acquired, which clearly show concealed rupture structures of obviously different age in the shallow sediments down to 100 m depth. Subject to depth

  11. Error types and error positions in neglect dyslexia: comparative analyses in neglect patients and healthy controls.

    PubMed

    Weinzierl, Christiane; Kerkhoff, Georg; van Eimeren, Lucia; Keller, Ingo; Stenneken, Prisca

    2012-10-01

    Unilateral spatial neglect frequently involves a lateralised reading disorder, neglect dyslexia (ND). Reading of single words in ND is characterised by left-sided omissions and substitutions of letters. However, it is unclear whether the distribution of error types and positions within a word shows a unique pattern of ND when directly compared to healthy controls. This question has been difficult to answer so far, given the usually low number of reading errors in healthy controls. Therefore, the present study compared single word reading of 18 patients with left-sided neglect, due to right-hemisphere stroke, and 11 age-matched healthy controls, and adjusted individual task difficulty (by varying stimulus presentation times in participants) in order to reach approximately equal error rates between neglect patients and controls. Results showed that, while both omission and substitution errors were frequently produced in neglect patients and controls, only omissions appeared neglect-specific when task difficulty was adapted between groups. Analyses of individual letter positions within words revealed that the spatial distribution of reading errors in the neglect dyslexic patients followed an almost linear increase from the end to the beginning of the word (right-to-left-gradient). Both, the gradient in error positions and the predominance of omission errors presented a neglect-specific pattern. Consistent with current models of visual word processing, these findings suggest that ND reflects sublexical, visuospatial attentional mechanisms in letter string encoding.

  12. Error Prevention Aid

    NASA Technical Reports Server (NTRS)

    1987-01-01

    In a complex computer environment there is ample opportunity for error, a mistake by a programmer, or a software-induced undesirable side effect. In insurance, errors can cost a company heavily, so protection against inadvertent change is a must for the efficient firm. The data processing center at Transport Life Insurance Company has taken a step to guard against accidental changes by adopting a software package called EQNINT (Equations Interpreter Program). EQNINT cross checks the basic formulas in a program against the formulas that make up the major production system. EQNINT assures that formulas are coded correctly and helps catch errors before they affect the customer service or its profitability.

  13. Estimating Bias Error Distributions

    NASA Technical Reports Server (NTRS)

    Liu, Tian-Shu; Finley, Tom D.

    2001-01-01

    This paper formulates the general methodology for estimating the bias error distribution of a device in a measuring domain from less accurate measurements when a minimal number of standard values (typically two values) are available. A new perspective is that the bias error distribution can be found as a solution of an intrinsic functional equation in a domain. Based on this theory, the scaling- and translation-based methods for determining the bias error distribution arc developed. These methods are virtually applicable to any device as long as the bias error distribution of the device can be sufficiently described by a power series (a polynomial) or a Fourier series in a domain. These methods have been validated through computational simulations and laboratory calibration experiments for a number of different devices.

  14. The surveillance error grid.

    PubMed

    Klonoff, David C; Lias, Courtney; Vigersky, Robert; Clarke, William; Parkes, Joan Lee; Sacks, David B; Kirkman, M Sue; Kovatchev, Boris

    2014-07-01

    Currently used error grids for assessing clinical accuracy of blood glucose monitors are based on out-of-date medical practices. Error grids have not been widely embraced by regulatory agencies for clearance of monitors, but this type of tool could be useful for surveillance of the performance of cleared products. Diabetes Technology Society together with representatives from the Food and Drug Administration, the American Diabetes Association, the Endocrine Society, and the Association for the Advancement of Medical Instrumentation, and representatives of academia, industry, and government, have developed a new error grid, called the surveillance error grid (SEG) as a tool to assess the degree of clinical risk from inaccurate blood glucose (BG) monitors. A total of 206 diabetes clinicians were surveyed about the clinical risk of errors of measured BG levels by a monitor. The impact of such errors on 4 patient scenarios was surveyed. Each monitor/reference data pair was scored and color-coded on a graph per its average risk rating. Using modeled data representative of the accuracy of contemporary meters, the relationships between clinical risk and monitor error were calculated for the Clarke error grid (CEG), Parkes error grid (PEG), and SEG. SEG action boundaries were consistent across scenarios, regardless of whether the patient was type 1 or type 2 or using insulin or not. No significant differences were noted between responses of adult/pediatric or 4 types of clinicians. Although small specific differences in risk boundaries between US and non-US clinicians were noted, the panel felt they did not justify separate grids for these 2 types of clinicians. The data points of the SEG were classified in 15 zones according to their assigned level of risk, which allowed for comparisons with the classic CEG and PEG. Modeled glucose monitor data with realistic self-monitoring of blood glucose errors derived from meter testing experiments plotted on the SEG when compared to

  15. Quantum Error Correction

    NASA Astrophysics Data System (ADS)

    Lidar, Daniel A.; Brun, Todd A.

    2013-09-01

    Prologue; Preface; Part I. Background: 1. Introduction to decoherence and noise in open quantum systems Daniel Lidar and Todd Brun; 2. Introduction to quantum error correction Dave Bacon; 3. Introduction to decoherence-free subspaces and noiseless subsystems Daniel Lidar; 4. Introduction to quantum dynamical decoupling Lorenza Viola; 5. Introduction to quantum fault tolerance Panos Aliferis; Part II. Generalized Approaches to Quantum Error Correction: 6. Operator quantum error correction David Kribs and David Poulin; 7. Entanglement-assisted quantum error-correcting codes Todd Brun and Min-Hsiu Hsieh; 8. Continuous-time quantum error correction Ognyan Oreshkov; Part III. Advanced Quantum Codes: 9. Quantum convolutional codes Mark Wilde; 10. Non-additive quantum codes Markus Grassl and Martin Rötteler; 11. Iterative quantum coding systems David Poulin; 12. Algebraic quantum coding theory Andreas Klappenecker; 13. Optimization-based quantum error correction Andrew Fletcher; Part IV. Advanced Dynamical Decoupling: 14. High order dynamical decoupling Zhen-Yu Wang and Ren-Bao Liu; 15. Combinatorial approaches to dynamical decoupling Martin Rötteler and Pawel Wocjan; Part V. Alternative Quantum Computation Approaches: 16. Holonomic quantum computation Paolo Zanardi; 17. Fault tolerance for holonomic quantum computation Ognyan Oreshkov, Todd Brun and Daniel Lidar; 18. Fault tolerant measurement-based quantum computing Debbie Leung; Part VI. Topological Methods: 19. Topological codes Héctor Bombín; 20. Fault tolerant topological cluster state quantum computing Austin Fowler and Kovid Goyal; Part VII. Applications and Implementations: 21. Experimental quantum error correction Dave Bacon; 22. Experimental dynamical decoupling Lorenza Viola; 23. Architectures Jacob Taylor; 24. Error correction in quantum communication Mark Wilde; Part VIII. Critical Evaluation of Fault Tolerance: 25. Hamiltonian methods in QEC and fault tolerance Eduardo Novais, Eduardo Mucciolo and

  16. Thermodynamics of Error Correction

    NASA Astrophysics Data System (ADS)

    Sartori, Pablo; Pigolotti, Simone

    2015-10-01

    Information processing at the molecular scale is limited by thermal fluctuations. This can cause undesired consequences in copying information since thermal noise can lead to errors that can compromise the functionality of the copy. For example, a high error rate during DNA duplication can lead to cell death. Given the importance of accurate copying at the molecular scale, it is fundamental to understand its thermodynamic features. In this paper, we derive a universal expression for the copy error as a function of entropy production and work dissipated by the system during wrong incorporations. Its derivation is based on the second law of thermodynamics; hence, its validity is independent of the details of the molecular machinery, be it any polymerase or artificial copying device. Using this expression, we find that information can be copied in three different regimes. In two of them, work is dissipated to either increase or decrease the error. In the third regime, the protocol extracts work while correcting errors, reminiscent of a Maxwell demon. As a case study, we apply our framework to study a copy protocol assisted by kinetic proofreading, and show that it can operate in any of these three regimes. We finally show that, for any effective proofreading scheme, error reduction is limited by the chemical driving of the proofreading reaction.

  17. A Concealed Intracranial Aneurysm Detected after Recanalization of an Occluded Vessel: A Case Report and Literature Review

    PubMed Central

    Torikoshi, Sadaharu; Akiyama, Yoshinori

    2016-01-01

    Background Based on the results of several randomized controlled trials, acute endovascular thrombectomy is strongly recommended for patients with acute ischemic stroke due to large artery occlusion (LAO). The incidence of an intracranial aneurysm has been reported to be approximately 5% in the general population. Therefore, the possibility of the coincidence of LAO and an intracranial aneurysm at the distal part of an occluded vessel should be considered. Summary A 74-year-old female patient presented with the sudden onset of consciousness disturbance and left-sided weakness. Neuroimages demonstrated an acute infarction due to right middle cerebral artery occlusion. The occlusion was successfully treated, and an aneurysm was incidentally detected at the occluded artery. We reviewed the literature and identified 11 cases in 8 reports, which were similar to our case. Among the 11 cases, aneurysms ruptured during endovascular therapy in 2 cases. In the present report, we discussed the prediction of concealed aneurysms and avoidance of their rupture during endovascular intervention. Key Message The presence of an aneurysm concealed behind an embolus should be carefully assessed on preoperative and intraoperative neuroimages. The important findings for suspecting such an aneurysm are a hyperdense nodular sign on preoperative computed tomography and unusual motion of the microwire during the endovascular intervention. Even if there is no finding indicative of an aneurysm, the catheter and thrombectomy devices should be more carefully advanced than usual, especially at the common sites of aneurysms, and the devices should be appropriately chosen. PMID:27051404

  18. Ultra wide band detection of on body concealed weapons using the out of plane polarized late time response

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

    A method of detecting concealed handguns and knives, both on and off body, has been developed. The method utilizes aspect-independent natural, complex resonances (poles) excited by illuminating the target with frequency swept, ultrawide band microwaves in the range 0.5 - 18 GHz. These natural resonances manifest as a Late Time Response (LTR) that extends significantly (~ 5 ns) beyond the direct reflections from the human body (the Early Time Response) and are of the form of a superposition of exponentially decaying sinusoidal waveforms. Two handguns are examined, both on the human body and in isolation, by the established methodology of applying the Generalised-Pencil-Of-Function to the late time response data of the target. These poles allow the weapon to be effectively classified. Out of plane polarized (cross-polarized) scattered response is used here as this gives improved discrimination between the early and late time responses. Determination of the presence or absence of particular weapons concealed under clothing, on the human body, is demonstrated. A novel bow-tie slot antenna is described which has good pulse and frequency response over the range 0.3-1 GHz and which is suitable for excitation of the fundamental natural resonances.

  19. A functional analysis of deception detection of a mock crime using infrared thermal imaging and the Concealed Information Test

    PubMed Central

    Park, Kevin K.; Suk, Hye Won; Hwang, Heungsun; Lee, Jang-Han

    2013-01-01

    The purpose of this study was to utilize thermal imaging and the Concealed Information Test to detect deception in participants who committed a mock crime. A functional analysis using a functional ANOVA and a functional discriminant analysis was conducted to decrease the variation in the physiological data collected through the thermal imaging camera. Participants chose between a non-crime mission (Innocent Condition: IC), or a mock crime (Guilty Condition: GC) of stealing a wallet in a computer lab. Temperature in the periorbital region of the face was measured while questioning participants regarding mock crime details. Results revealed that the GC showed significantly higher temperatures when responding to crime relevant items compared to irrelevant items, while the IC did not. The functional ANOVA supported the initial results that facial temperatures of the GC elevated when responding to crime relevant items, demonstrating an interaction between group (guilty/innocent) and relevance (relevant/irrelevant). The functional discriminant analysis revealed that answering crime relevant items can be used to discriminate guilty from innocent participants. These results suggest that measuring facial temperatures in the periorbital region while conducting the Concealed Information Test is able to differentiate the GC from the IC. PMID:23470924

  20. Alkylating antitumor drug mechlorethamine conceals a structured PrP domain and inhibits in vitro prion amplification.

    PubMed

    Zhou, Xiaochen; Bi, Hao; Wong, Justin; Shimoji, Miyuki; Wang, Yifan; Yuan, Jue; Xiao, Xiangzhu; Wang, Gong-Xian; Zou, Wen-Quan

    2011-01-01

    Prion diseases are a group of incurable transmissible neurodegenerative disorders. The key molecular event in the pathogenesis of prion diseases is the conversion of the cellular prion protein (PrP(C)) into its pathological isoform (PrP(Sc)), accompanied by a conformational transition of α-helix into β-sheet structure involving the structured α-helix 1 domain from residues 144-154 of the protein (PrP144-154). Blocking the accessibility of PrP144-152 with anti-PrP antibody 6H4 was found to prevent PrP conversion and even to cure prion infection in cell models ( Enari et al. 2001 ). Previously, Yuan et al. (2005 ) demonstrated that the reduction and alkylation of PrP induced concealment of the 6H4 epitope. This study examined the ability of mechlorethamine (MCT), an alkylating antitumor drug, to conceal the 6H4 epitope and block PrP conversion in the presence of a reducing reagent. Mechlorethamine treatment significantly decreased in vitro amplification of PrP(Sc) in the highly efficient protein misfolding cyclic amplification system. Our findings suggest that MCT may serve as a potential therapeutic agent for prion diseases.

  1. Electron beam injected into ground generates subsoil x-rays that may deactivate concealed electronics used to trigger explosive devices

    NASA Astrophysics Data System (ADS)

    Retsky, Michael

    2008-04-01

    Explosively formed projectiles (EFP) are a major problem in terrorism and asymmetrical warfare. EFPs are often triggered by ordinary infrared motion detectors. A potential weak link is that such electronics are not hardened to ionizing radiation and can latch-up or enter other inoperative states after exposure to a single short event of ionizing radiation. While these can often be repaired with a power restart, they also can produce shorts and permanent damage. A problem of course is that we do not want to add radiation exposure to the long list of war related hazards. Biological systems are highly sensitive to integrated dosage but show no particular sensitivity to short pulses. There may be a way to generate short pulsed subsoil radiation to deactivate concealed electronics without introducing radiation hazards to military personnel and civilian bystanders. Electron beams of 30 MeV that can be produced by portable linear accelerators (linacs) propagate >20 m in air and 10-12 cm in soil. X-radiation is produced by bremsstrahlung and occurs subsoil beneath the point of impact and is mostly forward directed. Linacs 1.5 m long can produce 66 MWatt pulses of subsoil x-radiation 1 microsecond or less in duration. Untested as yet, such a device could be mounted on a robotic vehicle that precedes a military convoy and deactivates any concealed electronics within 10-20 meters on either side of the road.

  2. A functional analysis of deception detection of a mock crime using infrared thermal imaging and the Concealed Information Test.

    PubMed

    Park, Kevin K; Suk, Hye Won; Hwang, Heungsun; Lee, Jang-Han

    2013-01-01

    The purpose of this study was to utilize thermal imaging and the Concealed Information Test to detect deception in participants who committed a mock crime. A functional analysis using a functional ANOVA and a functional discriminant analysis was conducted to decrease the variation in the physiological data collected through the thermal imaging camera. Participants chose between a non-crime mission (Innocent Condition: IC), or a mock crime (Guilty Condition: GC) of stealing a wallet in a computer lab. Temperature in the periorbital region of the face was measured while questioning participants regarding mock crime details. Results revealed that the GC showed significantly higher temperatures when responding to crime relevant items compared to irrelevant items, while the IC did not. The functional ANOVA supported the initial results that facial temperatures of the GC elevated when responding to crime relevant items, demonstrating an interaction between group (guilty/innocent) and relevance (relevant/irrelevant). The functional discriminant analysis revealed that answering crime relevant items can be used to discriminate guilty from innocent participants. These results suggest that measuring facial temperatures in the periorbital region while conducting the Concealed Information Test is able to differentiate the GC from the IC.

  3. Error monitoring in musicians

    PubMed Central

    Maidhof, Clemens

    2013-01-01

    To err is human, and hence even professional musicians make errors occasionally during their performances. This paper summarizes recent work investigating error monitoring in musicians, i.e., the processes and their neural correlates associated with the monitoring of ongoing actions and the detection of deviations from intended sounds. Electroencephalography (EEG) studies reported an early component of the event-related potential (ERP) occurring before the onsets of pitch errors. This component, which can be altered in musicians with focal dystonia, likely reflects processes of error detection and/or error compensation, i.e., attempts to cancel the undesired sensory consequence (a wrong tone) a musician is about to perceive. Thus, auditory feedback seems not to be a prerequisite for error detection, consistent with previous behavioral results. In contrast, when auditory feedback is externally manipulated and thus unexpected, motor performance can be severely distorted, although not all feedback alterations result in performance impairments. Recent studies investigating the neural correlates of feedback processing showed that unexpected feedback elicits an ERP component after note onsets, which shows larger amplitudes during music performance than during mere perception of the same musical sequences. Hence, these results stress the role of motor actions for the processing of auditory information. Furthermore, recent methodological advances like the combination of 3D motion capture techniques with EEG will be discussed. Such combinations of different measures can potentially help to disentangle the roles of different feedback types such as proprioceptive and auditory feedback, and in general to derive at a better understanding of the complex interactions between the motor and auditory domain during error monitoring. Finally, outstanding questions and future directions in this context will be discussed. PMID:23898255

  4. Intractable paroxysmal tachycardia caused by a concealed retrogradely conducting Kent bundle. Demonstration by epicardial mapping and cure of tachycardias by surgical interruption of the His bundle.

    PubMed Central

    Denes, P; Wyndham, C R; Rosen, K M

    1976-01-01

    Electrophysiological and epicardial mapping studies are described in a patient without pre-excitation who had intractable recurrent paroxysmal supraventricular tachycardia. Electrophysiological studies revealed fixed VA conduction times during both rapid ventricular pacing and coupled ventricular stimulation. Catheter mapping of atrial activation during retrograde conduction and during induced paroxysmal supraventricular tachycardia revealed early distal coronary sinus activation (posterior left atrium) relative to the low septal, low lateral, and high lateral right atrium. These studies suggested the presence of a concealed left-sided bypass tract. The patient underwent surgical interruption of the His bundle for control of paroxysmal supraventricular tachycardia. Epicardial mapping of the atria (during ventricular pacing) confirmed the presence of a concealed left-sided bypass tract. Surgery produced antegrade av block (while retrograde conduction was maintained) and total cure of paroxysmal supraventricular tachycardia. This is the first reported case of a concealed retrograde extranodal pathway documented by epicardial mapping. Images PMID:973901

  5. Geophysical and geochemical data from the area of the Pebble Cu-Au-Mo porphyry deposit, southwestern Alaska: Contributions to assessment techniques for concealed mineral resources

    USGS Publications Warehouse

    Anderson, E.D.; Smith, S.M.; Giles, S.A.; Granitto, Matthew; Eppinger, R.G.; Bedrosian, P.A.; Shah, A.K.; Kelley, K.D.; Fey, D.L.; Minsley, B.J.; Brown, P.J.

    2011-01-01

    In 2007, the U.S. Geological Survey began a multidisciplinary study in southwest Alaska to investigate the setting and detectability of mineral deposits in concealed volcanic and glacial terranes. The study area hosts the world-class Pebble porphyry Cu-Au-Mo deposit, and through collaboration with the Pebble Limited Partnership, a range of geophysical and geochemical investigations was carried out in proximity to the deposit. The deposit is almost entirely concealed by tundra, glacial deposits, and post-mineralization volcanic rocks. The discovery of mineral resources beneath cover is becoming more important because most of the mineral resources at the surface have already been discovered. Research is needed to identify ways in which to assess for concealed mineral resources. This report presents the uninterpreted geophysical measurements and geochemical and mineralogical analytical data from samples collected during the summer field seasons from 2007 to 2010, and makes the data available in a single Geographic Information System (GIS) database.

  6. Errata: Papers in Error Analysis.

    ERIC Educational Resources Information Center

    Svartvik, Jan, Ed.

    Papers presented at the symposium of error analysis in Lund, Sweden, in September 1972, approach error analysis specifically in its relation to foreign language teaching and second language learning. Error analysis is defined as having three major aspects: (1) the description of the errors, (2) the explanation of errors by means of contrastive…

  7. Error Types and Error Positions in Neglect Dyslexia: Comparative Analyses in Neglect Patients and Healthy Controls

    ERIC Educational Resources Information Center

    Weinzierl, Christiane; Kerkhoff, Georg; van Eimeren, Lucia; Keller, Ingo; Stenneken, Prisca

    2012-01-01

    Unilateral spatial neglect frequently involves a lateralised reading disorder, neglect dyslexia (ND). Reading of single words in ND is characterised by left-sided omissions and substitutions of letters. However, it is unclear whether the distribution of error types and positions within a word shows a unique pattern of ND when directly compared to…

  8. Error and Uncertainty Analysis for Ecological Modeling and Simulation

    DTIC Science & Technology

    2001-12-01

    in GIS has been proposed by Openshaw (1992) based on Monte Carlo simulation (recommended method). As we mentioned above, however, this method is...Modelling, 8: 297-311. Openshaw , S., 1992. Learning to live with errors in spatial databases. Accuracy of spatial databases (Eds. Goodchild, M., & S

  9. Phase errors due to speckles in laser fringe projection.

    PubMed

    Rosendahl, Sara; Hällstig, Emil; Gren, Per; Sjödahl, Mikael

    2010-04-10

    When measuring a three-dimensional shape with triangulation and projected interference fringes it is of interest to reduce speckle contrast without destroying the coherence of the projected light. A moving aperture is used to suppress the speckles and thereby reduce the phase error in the fringe image. It is shown that the phase error depends linearly on the ratio between the speckle contrast and the modulation of the fringes. In this investigation the spatial carrier method was used to extract the phase, where the phase error also depends on filtering the Fourier spectrum. An analytical expression for the phase error is derived. Both the speckle reduction and the theoretical expressions for the phase error are verified by simulations and experiments. It was concluded that a movement of the aperture by three aperture diameters during exposure of the image reduces the speckle contrast and hence the phase error by 60%. In the experiments, a phase error of 0.2 rad was obtained.

  10. Temporospatial dissociation of Pe subcomponents for perceived and unperceived errors.

    PubMed

    Endrass, Tanja; Klawohn, Julia; Preuss, Julia; Kathmann, Norbert

    2012-01-01

    Previous research on performance monitoring revealed that errors are followed by an initial fronto-central negative deflection (error-related negativity, ERN or Ne) and a subsequent centro-parietal positivity (error positivity, Pe). It has been shown that error awareness mainly influences the Pe, whereas the ERN seems unaffected by conscious awareness of an error. The aim of the present study was to investigate the relation of ERN and Pe to error awareness in a visual size discrimination task in which errors are not elicited by impulsive responding but by perceptual difficulty. Further, we applied a temporospatial principal component analysis (PCA) to examine whether the temporospatial subcomponents of the Pe would differentially relate to error awareness. Event-related potential (ERP) results were in accordance with earlier studies: a significant error awareness effect was found for the Pe, but not for the ERN. Interestingly, a modulation with error perception on correct trials was found: correct responses considered as incorrect had larger correct-related negativity (CRN) and lager Pe amplitudes than correct responses considered as correct. The PCA yielded two relevant spatial factors accounting for the Pe (latency 300 ms). A temporospatial factor characterized by a centro-parietal positivity varied significantly with error awareness. Of the two temporospatial factors corresponding to ERN and CRN, one factor with central topography varied with response correctness and subjective error perception on correct responses. The PCA results indicate that the error awareness effect is specifically related to the centro-parietal subcomponent of the Pe. Since this component has also been shown to be related to the importance of an error, the present variation with error awareness indicates that this component is sensitive to the salience of an error and that salience secondarily may trigger error awareness.

  11. Error Sensitivity Model.

    DTIC Science & Technology

    1980-04-01

    Philosophy The Positioning/Error Model has been defined in three dis- tinct phases: I - Error Sensitivity Model II - Operonal Positioning Model III...X inv VH,’itat NX*YImpY -IY+X 364: mat AX+R 365: ara R+L+R 366: if NC1,1J-N[2,2)=O and N[1,2<135+T;j, 6 367: if NC1,1]-N2,2J=6 and NCI2=;0.T;jmp 5

  12. Error Free Software

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A mathematical theory for development of "higher order" software to catch computer mistakes resulted from a Johnson Space Center contract for Apollo spacecraft navigation. Two women who were involved in the project formed Higher Order Software, Inc. to develop and market the system of error analysis and correction. They designed software which is logically error-free, which, in one instance, was found to increase productivity by 600%. USE.IT defines its objectives using AXES -- a user can write in English and the system converts to computer languages. It is employed by several large corporations.

  13. The impact of transmission errors on progressive 720 lines HDTV coded with H.264

    NASA Astrophysics Data System (ADS)

    Brunnström, Kjell; Stålenbring, Daniel; Pettersson, Martin; Gustafsson, Jörgen

    2010-02-01

    TV sent over the networks based on the Internet Protocol i.e IPTV is moving towards high definition (HDTV). There has been quite a lot of work on how the HDTV is affected by different codecs and bitrates, but the impact of transmission errors over IP-networks have been less studied. The study was focusing on H.264 encoded 1280x720 progressive HDTV format and was comparing three different concealment methods for different packet loss rates. One is included in a propriety decoder, one is part of FFMPEG and different length of freezing. The target is to simulate what typically IPTV settop-boxes will do when encountering packet loss. Another aim is to study whether the presentation upscaled on the full HDTV screen or presented pixel mapped in a smaller area in the center of the sceen would have an effect on the quality. The results show that there were differences between the two packet loss concealment methods in FFMPEG and in the propriety codec. Freezing seemed to have similar effect as been reported before. For low rates of transmission errors the coding impairments has impact on the quality, but for higher degree of transmission errors these does not affect the quality, since they become overshadowed by transmission error. An interesting effect where the higher bitrate videos goes from having higher quality for lower degree of packet loss, to having lower quality than the lower bitrate video at higher packet loss, was discovered. The different way of presenting the video i.e. upscaled or not-upscaled was significant on the 95% level, but just about.

  14. Influence of Ephemeris Error on GPS Single Point Positioning Accuracy

    NASA Astrophysics Data System (ADS)

    Lihua, Ma; Wang, Meng

    2013-09-01

    The Global Positioning System (GPS) user makes use of the navigation message transmitted from GPS satellites to achieve its location. Because the receiver uses the satellite's location in position calculations, an ephemeris error, a difference between the expected and actual orbital position of a GPS satellite, reduces user accuracy. The influence extent is decided by the precision of broadcast ephemeris from the control station upload. Simulation analysis with the Yuma almanac show that maximum positioning error exists in the case where the ephemeris error is along the line-of-sight (LOS) direction. Meanwhile, the error is dependent on the relationship between the observer and spatial constellation at some time period.

  15. Orwell's Instructive Errors

    ERIC Educational Resources Information Center

    Julian, Liam

    2009-01-01

    In this article, the author talks about George Orwell, his instructive errors, and the manner in which Orwell pierced worthless theory, faced facts and defended decency (with fluctuating success), and largely ignored the tradition of accumulated wisdom that has rendered him a timeless teacher--one whose inadvertent lessons, while infrequently…

  16. High-Resolution, Slant-Angle Scene Generation and Validation of Concealed Targets in DIRSIG

    DTIC Science & Technology

    2007-11-02

    used to ensure the statistical and spatial integrity of the scenes that were generated in this project. As with any image comparison, the first step is...for this type of simulation. It will also describe the mathematical theory be- hind ROC, GML classification, the RX algorithm, and gray level co...common ATR algorithms use statistical or neural net classifiers and therefore require a great deal of training data. Multiple scenes must be imaged for

  17. Quantifying the impact of material-model error on macroscale quantities-of-interest using multiscale a posteriori error-estimation techniques

    SciTech Connect

    Brown, Judith A.; Bishop, Joseph E.

    2016-07-20

    An a posteriori error-estimation framework is introduced to quantify and reduce modeling errors resulting from approximating complex mesoscale material behavior with a simpler macroscale model. Such errors may be prevalent when modeling welds and additively manufactured structures, where spatial variations and material textures may be present in the microstructure. We consider a case where a <100> fiber texture develops in the longitudinal scanning direction of a weld. Transversely isotropic elastic properties are obtained through homogenization of a microstructural model with this texture and are considered the reference weld properties within the error-estimation framework. Conversely, isotropic elastic properties are considered approximate weld properties since they contain no representation of texture. Errors introduced by using isotropic material properties to represent a weld are assessed through a quantified error bound in the elastic regime. Lastly, an adaptive error reduction scheme is used to determine the optimal spatial variation of the isotropic weld properties to reduce the error bound.

  18. Report of the Subpanel on Error Characterization and Error Budgets

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The state of knowledge of both user positioning requirements and error models of current and proposed satellite systems is reviewed. In particular the error analysis models for LANDSAT D are described. Recommendations are given concerning the geometric error model for the thematic mapper; interactive user involvement in system error budgeting and modeling and verification on real data sets; and the identification of a strawman mission for modeling key error sources.

  19. Acquired spatial dyslexia.

    PubMed

    Siéroff, E

    2015-08-10

    Acquired spatial dyslexia is a reading disorder frequently occurring after left or right posterior brain lesions. This article describes several types of spatial dyslexia with an attentional approach. After right posterior lesions, patients show left neglect dyslexia with errors on the left side of text, words, and non-words. The deficit is frequently associated with left unilateral spatial neglect. Severe left neglect dyslexia can be detected with unlimited exposure duration of words or non-words. Minor neglect dyslexia is detected with brief presentation of bilateral words, one in the left and one in the right visual field (phenomenon of contralesional extinction). Neglect dyslexia can be explained as a difficulty in orienting attention to the left side of verbal stimuli. With left posterior lesions, spatial dyslexia is also frequent but multiform. Right neglect dyslexia is frequent, but right unilateral spatial neglect is rare. Attentional dyslexia represents difficulty in selecting a stimulus, letter or word among other similar stimuli; it is a deficit of attentional selection, and the left hemisphere plays a crucial role in selection. Two other types of spatial dyslexia can be found after left posterior lesions: paradoxical ipsilesional extinction and stimulus-centred neglect dyslexia. Disconnections between left or right parietal attentional areas and the left temporal visual word form area could explain these deficits. Overall, a model of attention dissociating modulation, selection control, and selection positioning can help in understanding these reading disorders.

  20. Lead isotopes in iron and manganese oxide coatings and their use as an exploration guide for concealed mineralization

    USGS Publications Warehouse

    Gulson, B.L.; Church, S.E.; Mizon, K.J.; Meier, A.L.

    1992-01-01

    Lead isotopes from Fe and Mn oxides that coat stream pebbles from around the Mount Emmons porphyry molybdenum deposit in Colorado were studied to assess the feasibility of using Pb isotopes to detect concealed mineral deposits. The Fe/Mn oxide coatings were analyzed to determine their elemental concentrations using ICP-AES. The Pb isotope compositions of solutions from a selected suite of samples were measured, using both thermal ionization and ICP mass spectrometry, to compare results determined by the two analytical methods. Heavy mineral concentrates from the same sites were also analyzed to compare the Pb isotope compositions of the Fe/Mn coatings with those found in panned concentrates. The Fe/Mn and 206Pb/204Pb ratios of the oxide coatings are related to the lithology of the host rocks; Fe/Mn oxide coatings on pebbles of black shale have higher Fe/Mn values than do the coatings on either sandstone or igneous rocks. The shale host rocks have a more radiogenic signature (e.g. higher 206Pb/ 204Pb) than the sandstone or igneous host rocks. The Pb isotope data from sandstone and igneous hosts can detect concealed mineralized rock on both a regional and local scale, even though there are contributions from: (1) metals from the main-stage molybdenite ore deposit; (2) metals from the phyllic alteration zone which has a more radiogenic Pb isotope signature reflecting hydrothermal leaching of Pb from the Mancos Shale; (3) Pb-rich base metal veins with a highly variable Pb isotope signature; and (4) sedimentary country rocks which have a more radiogenic Pb isotope signature. An investigation of within-stream variation shows that the Pb isotope signature of the molybdenite ore zone is retained in the Fe/Mn oxide coatings and is not camouflaged by contributions from Pb-rich base-metal veins that crop out upstream. In another traverse, the Pb isotope data from Fe/Mn oxide coatings reflect a complex mixing of Pb from the molybdenite ore zone and its hornfels margin, Pb

  1. The impact of prior knowledge from participant instructions in a mock crime P300 Concealed Information Test.

    PubMed

    Winograd, Michael R; Rosenfeld, J Peter

    2014-12-01

    In P300-Concealed Information Tests used with mock crime scenarios, the amount of detail revealed to a participant prior to the commission of the mock crime can have a serious impact on a study's validity. We predicted that exposure to crime details through instructions would bias detection rates toward enhanced sensitivity. In a 2 × 2 factorial design, participants were either informed (through mock crime instructions) or naïve as to the identity of a to-be-stolen item, and then either committed (guilty) or did not commit (innocent) the crime. Results showed that prior knowledge of the stolen item was sufficient to cause 69% of innocent-informed participants to be incorrectly classified as guilty. Further, we found a trend toward enhanced detection rate for guilty-informed participants over guilty-naïve participants. Results suggest that revealing details to participants through instructions biases detection rates in the P300-CIT toward enhanced sensitivity.

  2. Discovery of a concealed geothermal resource in the Alturas Basin, and its implications for further exploration in northeastern California

    SciTech Connect

    Bohm, B.; Juncal, R.W.

    1995-12-31

    In 1988 a so far unknown geothermal resource was drilled into under the City of Alturas in northeastern California. A fracture was tapped below 2300 feet, in cemented fine-grained tuffs and mudflows, producing 182{degrees}F water. The well has been used since 1990 to heat the local high school. A second well was drilled in 1991, producing about 250 gpm 182{degrees}F water from a fracture below 1893 ft. Well productivities and artesian pressures are variable, depending on distance from a major fault zone and local hydrologic regime. It appears as if the wells produce from deep reaching fractures in a caprock, that may conceal a 300 to 400{degrees}F resource between 4000 and 6000 feet depth. The results have important implications for geothermal exploration in northeastern California, i.e. just because there are no surface manifestations in a basin, it does not necessarily mean there is no geothermal resource at depth.

  3. Geochemical Data for Samples Collected in 2007 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.

    2008-01-01

    In the summer of 2007, the U.S. Geological Survey (USGS) began an exploration geochemical research study over the Pebble porphyry copper-gold-molydenum (Cu-Au-Mo) deposit in southwest Alaska. The Pebble deposit is extremely large and is almost entirely concealed by tundra, glacial deposits, and post-Cretaceous volcanic and volcaniclastic rocks. The deposit is presently being explored by Northern Dynasty Minerals, Ltd., and Anglo-American LLC. The USGS undertakes unbiased, broad-scale mineral resource assessments of government lands to provide Congress and citizens with information on national mineral endowment. Research on known deposits is also done to refine and better constrain methods and deposit models for the mineral resource assessments. The Pebble deposit was chosen for this study because it is concealed by surficial cover rocks, it is relatively undisturbed (except for exploration company drill holes), it is a large mineral system, and it is fairly well constrained at depth by the drill hole geology and geochemistry. The goals of the USGS study are (1) to determine whether the concealed deposit can be detected with surface samples, (2) to better understand the processes of metal migration from the deposit to the surface, and (3) to test and develop methods for assessing mineral resources in similar concealed terrains. This report presents analytical results for geochemical samples collected in 2007 from the Pebble deposit and surrounding environs. The analytical data are presented digitally both as an integrated Microsoft 2003 Access? database and as Microsoft 2003 Excel? files. The Pebble deposit is located in southwestern Alaska on state lands about 30 km (18 mi) northwest of the village of Illiamna and 320 km (200 mi) southwest of Anchorage (fig. 1). Elevations in the Pebble area range from 287 m (940 ft) at Frying Pan Lake just south of the deposit to 1146 m (3760 ft) on Kaskanak Mountain about 5 km (5 mi) to the west. The deposit is in an area of

  4. Hidden from health: structural stigma, sexual orientation concealment, and HIV across 38 countries in the European MSM Internet Survey

    PubMed Central

    Pachankis, John E.; Hatzenbuehler, Mark L.; Hickson, Ford; Weatherburn, Peter; Berg, Rigmor C.; Marcus, Ulrich; Schmidt, Axel J.

    2016-01-01

    Objective Substantial country-level variation exists in prejudiced attitudes towards male homosexuality and in the extent to which countries promote the unequal treatment of MSM through discriminatory laws. The impact and underlying mechanisms of country-level stigma on odds of diagnosed HIV, sexual opportunities, and experience of HIV-prevention services, needs and behaviours have rarely been examined, however. Design Data come from the European MSM Internet Survey (EMIS), which was administered between June and August 2010 across 38 European countries (N =174 209). Methods Country-level stigma was assessed using a combination of national laws and policies affecting sexual minorities and a measure of attitudes held by the citizens of each country. We also assessed concealment, HIV status, number of past 12-month male sex partners, and eight HIV-preventive services, knowledge, and behavioural outcomes. Results MSM living in countries with higher levels of stigma had reduced odds of diagnosed HIV and fewer partners but higher odds of sexual risk behaviour, unmet prevention needs, not using testing services, and not discussing their sexuality in testing services. Sexual orientation concealment mediated associations between country-level stigma and these outcomes. Conclusion Country-level stigma may have historically limited HIV transmission opportunities among MSM, but by restricting MSM’s public visibility, it also reduces MSM’s ability to access HIV-preventive services, knowledge and precautionary behaviours. These findings suggest that MSM in European countries with high levels of stigma are vulnerable to HIV infection. Although they have less opportunity to identify and contact other MSM, this might change with emerging technologies. PMID:26035323

  5. Automatic Error Analysis Using Intervals

    ERIC Educational Resources Information Center

    Rothwell, E. J.; Cloud, M. J.

    2012-01-01

    A technique for automatic error analysis using interval mathematics is introduced. A comparison to standard error propagation methods shows that in cases involving complicated formulas, the interval approach gives comparable error estimates with much less effort. Several examples are considered, and numerical errors are computed using the INTLAB…

  6. Control by model error estimation

    NASA Technical Reports Server (NTRS)

    Likins, P. W.; Skelton, R. E.

    1976-01-01

    Modern control theory relies upon the fidelity of the mathematical model of the system. Truncated modes, external disturbances, and parameter errors in linear system models are corrected by augmenting to the original system of equations an 'error system' which is designed to approximate the effects of such model errors. A Chebyshev error system is developed for application to the Large Space Telescope (LST).

  7. Imagery of Errors in Typing

    ERIC Educational Resources Information Center

    Rieger, Martina; Martinez, Fanny; Wenke, Dorit

    2011-01-01

    Using a typing task we investigated whether insufficient imagination of errors and error corrections is related to duration differences between execution and imagination. In Experiment 1 spontaneous error imagination was investigated, whereas in Experiment 2 participants were specifically instructed to imagine errors. Further, in Experiment 2 we…

  8. Speech Errors across the Lifespan

    ERIC Educational Resources Information Center

    Vousden, Janet I.; Maylor, Elizabeth A.

    2006-01-01

    Dell, Burger, and Svec (1997) proposed that the proportion of speech errors classified as anticipations (e.g., "moot and mouth") can be predicted solely from the overall error rate, such that the greater the error rate, the lower the anticipatory proportion (AP) of errors. We report a study examining whether this effect applies to changes in error…

  9. Mental Health Stigma, Self-Concealment, and Help-Seeking Attitudes among Asian American and European American College Students with No Help-Seeking Experience

    ERIC Educational Resources Information Center

    Masuda, Akihiko; Boone, Matthew S.

    2011-01-01

    The present study examined whether mental health stigma (i.e., negative attitudes toward people with a psychological disorder) and self-concealment are unique predictors of help-seeking attitudes in Asian American and European American college students with no history of seeking professional psychological services. The Asian American group had…

  10. Mental Health Stigma and Self-Concealment as Predictors of Help-Seeking Attitudes among Latina/o College Students in the United States

    ERIC Educational Resources Information Center

    Mendoza, Hadrian; Masuda, Akihiko; Swartout, Kevin M.

    2015-01-01

    The study examined whether mental health stigma and self-concealment are uniquely related to various dimensions of attitudes toward seeking professional psychological services (i.e., help-seeking attitudes) in Latina/o college students. Data from 129 Latina/o undergraduates (76% female) were used in the analysis. Results revealed that mental…

  11. Attitudes toward Face-to-Face and Online Counseling: Roles of Self-Concealment, Openness to Experience, Loss of Face, Stigma, and Disclosure Expectations among Korean College Students

    ERIC Educational Resources Information Center

    Bathje, Geoff J.; Kim, Eunha; Rau, Ellen; Bassiouny, Muhammad Adam; Kim, Taehoon

    2014-01-01

    This study examined attitudes toward face-to-face (f2f) and online counseling among 228 Korean college students. In addition, it tested a hypothesized model proposing that general propensities (i.e., self-concealment, openness to experience, and loss of face) would influence counseling-specific expectations (i.e., self-stigma and disclosure…

  12. Hyponatremia: management errors.

    PubMed

    Seo, Jang Won; Park, Tae Jin

    2006-11-01

    Rapid correction of hyponatremia is frequently associated with increased morbidity and mortality. Therefore, it is important to estimate the proper volume and type of infusate required to increase the serum sodium concentration predictably. The major common management errors during the treatment of hyponatremia are inadequate investigation, treatment with fluid restriction for diuretic-induced hyponatremia and treatment with fluid restriction plus intravenous isotonic saline simultaneously. We present two cases of management errors. One is about the problem of rapid correction of hyponatremia in a patient with sepsis and acute renal failure during continuous renal replacement therapy in the intensive care unit. The other is the case of hypothyroidism in which hyponatremia was aggravated by intravenous infusion of dextrose water and isotonic saline infusion was erroneously used to increase serum sodium concentration.

  13. Error-Free Software

    NASA Technical Reports Server (NTRS)

    1989-01-01

    001 is an integrated tool suited for automatically developing ultra reliable models, simulations and software systems. Developed and marketed by Hamilton Technologies, Inc. (HTI), it has been applied in engineering, manufacturing, banking and software tools development. The software provides the ability to simplify the complex. A system developed with 001 can be a prototype or fully developed with production quality code. It is free of interface errors, consistent, logically complete and has no data or control flow errors. Systems can be designed, developed and maintained with maximum productivity. Margaret Hamilton, President of Hamilton Technologies, also directed the research and development of USE.IT, an earlier product which was the first computer aided software engineering product in the industry to concentrate on automatically supporting the development of an ultrareliable system throughout its life cycle. Both products originated in NASA technology developed under a Johnson Space Center contract.

  14. Modular error embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.; Ettinger, J. Mark

    1999-01-01

    A method of embedding auxiliary information into the digital representation of host data containing noise in the low-order bits. The method applies to digital data representing analog signals, for example digital images. The method reduces the error introduced by other methods that replace the low-order bits with auxiliary information. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user through use of a digital key. The modular error embedding method includes a process to permute the order in which the host data values are processed. The method doubles the amount of auxiliary information that can be added to host data values, in comparison with bit-replacement methods for high bit-rate coding. The invention preserves human perception of the meaning and content of the host data, permitting the addition of auxiliary data in the amount of 50% or greater of the original host data.

  15. Error-correction coding

    NASA Technical Reports Server (NTRS)

    Hinds, Erold W. (Principal Investigator)

    1996-01-01

    This report describes the progress made towards the completion of a specific task on error-correcting coding. The proposed research consisted of investigating the use of modulation block codes as the inner code of a concatenated coding system in order to improve the overall space link communications performance. The study proposed to identify and analyze candidate codes that will complement the performance of the overall coding system which uses the interleaved RS (255,223) code as the outer code.

  16. Surface temperature measurement errors

    SciTech Connect

    Keltner, N.R.; Beck, J.V.

    1983-05-01

    Mathematical models are developed for the response of surface mounted thermocouples on a thick wall. These models account for the significant causes of errors in both the transient and steady-state response to changes in the wall temperature. In many cases, closed form analytical expressions are given for the response. The cases for which analytical expressions are not obtained can be easily evaluated on a programmable calculator or a small computer.

  17. Bayesian Error Estimation Functionals

    NASA Astrophysics Data System (ADS)

    Jacobsen, Karsten W.

    The challenge of approximating the exchange-correlation functional in Density Functional Theory (DFT) has led to the development of numerous different approximations of varying accuracy on different calculated properties. There is therefore a need for reliable estimation of prediction errors within the different approximation schemes to DFT. The Bayesian Error Estimation Functionals (BEEF) have been developed with this in mind. The functionals are constructed by fitting to experimental and high-quality computational databases for molecules and solids including chemisorption and van der Waals systems. This leads to reasonably accurate general-purpose functionals with particual focus on surface science. The fitting procedure involves considerations on how to combine different types of data, and applies Tikhonov regularization and bootstrap cross validation. The methodology has been applied to construct GGA and metaGGA functionals with and without inclusion of long-ranged van der Waals contributions. The error estimation is made possible by the generation of not only a single functional but through the construction of a probability distribution of functionals represented by a functional ensemble. The use of the functional ensemble is illustrated on compound heat of formation and by investigations of the reliability of calculated catalytic ammonia synthesis rates.

  18. ‘I am doing fine only because I have not told anyone’: the necessity of concealment in the lives of people living with HIV in India

    PubMed Central

    George, Mathew Sunil; Lambert, Helen

    2015-01-01

    In HIV prevention and care programmes, disclosure of status by HIV-positive individuals is generally encouraged to contain the infection and provide adequate support to the person concerned. Lack of disclosure is generally framed as a barrier to preventive behaviours and accessing support. The assumption that disclosure is beneficial is also reflected in studies that aim to identify determinants of disclosure and recommend individual-level measures to promote disclosure. However, in contexts where HIV infection is stigmatised and there is fear of rejection and discrimination among those living with HIV, concealment of status becomes a way to try and regain as much as possible the life that was disrupted by the discovery of HIV infection. In this study of HIV-positive women and children in India, concealment was considered essential by individuals and families of those living with HIV to re-establish and maintain their normal lives in an environment where stigma and discrimination were prevalent. This paper describes why women and care givers of children felt the need to conceal HIV status, the various ways in which people tried to do so and the implications for treatment of people living with HIV. We found that while women were generally willing to disclose their status to their husband or partner, they were very keen to conceal their status from all others, including family members. Parents and carers with an HIV-positive child were not willing to disclose this status to the child or to others. Understanding the different rationales for concealment would help policy makers and programme managers to develop more appropriate care management strategies and train care providers to assist clients in accessing care and support without disrupting their lives. PMID:25706959

  19. Mid-Range Spatial Frequency Errors in Optical Components.

    DTIC Science & Technology

    1983-01-01

    pattern. Malacara (1978, pp. 356-359) describes the diffraction intensity distri- bution on either side of the focal plane and presents a diagram of the...Leoble and Co., Ltd., Aug. 1963. Kintner, Eric C., and Richard M. Sillitto. "A New Analytic Method for Computing the Optical Transfer Function." OPTICA ...2, 1976. Malacara , Daniel (ed). Optical Shop Testing. New York: John Wiley and Sons, 1978. Reticon Corporation. Reticon G Series Data Sheet. Sunnyvale, CA: Reticon, 1976. 41 FILMED 9-85 DTIC

  20. Field Vectors to Metamorphosed Ores: A Prelude to Finding Currently Concealed Volcano-Plutonic Arc Settings and Their Mineral Deposits in The Grenville Province

    NASA Astrophysics Data System (ADS)

    Corriveau, L.; Bonnet, A.; van Breemen, O.

    2004-05-01

    Recent mineral deposits synthesis highlights the largely barren nature of the high-grade metamorphic terrains of the Canadian Shield in terms of large mining camps. No where is the gap most startling than in the Grenville Province even though a lot of its Paleo- to Mesoproterozoic crust consists of magmatic arcs renown worldwide to host IOCG, VHMS and Porphyry Cu deposits. All these deposit types have significant alteration halos that can serve as vectors to ore. The use of such vectors forced a complete reinterpretation of the nature of the La Romaine domain in the eastern Grenville Province. Mapped in the 70's as being a metasedimentary basin with >500 km2 of meta-arkose and minor pelite, quartzite, conglomerate and marble, the domain is herein reassessed as a major 1.5 Ga Pinwarian continental magmatic arc fertile in Cu-sulphides and Fe-oxides mineralizing systems. The original markers used to prognosticate a sedimentary origin can now be demonstrated to be a series of rhyolitic to dacitic lapillistone, sericitized tuff with Al nodules and veins, Al gneiss locally with lapilli textures, garnetite, ironstones and calc-silicate rocks. The distribution, paragenesis and mode of the Al-, Fe- and Ca-rich units significantly depart from those of normal metasediments but are very diagnostic of metamorphosed hydrothermal alteration zones and meta-exhalites. Mapping alteration vectors provided clues to search for and find the volcanic rocks concealed among the composite granitic gneiss, the zones of hydrothermal leaching (e.g., sericitic, argillic and advanced argillic alterations) and discharge, the cap rocks, and the Cu mineralization. Spatial and stratigraphic relationships provided a means to compare their settings with ore deposit models. Roof pendants of Ba-rich meta-exhalite in surrounding 1.5 Ga granitic plutons and intrusion of 1495 Ma Qtz-Kfs porphyry across hydrothermally altered 1500 Ma tuffs attest to coeval hydrothermal activity and sub-volcanic plutons. The

  1. Spatial cognition

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary Kister; Remington, Roger

    1988-01-01

    Spatial cognition is the ability to reason about geometric relationships in the real (or a metaphorical) world based on one or more internal representations of those relationships. The study of spatial cognition is concerned with the representation of spatial knowledge, and our ability to manipulate these representations to solve spatial problems. Spatial cognition is utilized most critically when direct perceptual cues are absent or impoverished. Examples are provided of how human spatial cognitive abilities impact on three areas of space station operator performance: orientation, path planning, and data base management. A videotape provides demonstrations of relevant phenomena (e.g., the importance of orientation for recognition of complex, configural forms). The presentation is represented by abstract and overhead visuals only.

  2. Surface errors in the course of machining precision optics

    NASA Astrophysics Data System (ADS)

    Biskup, H.; Haberl, A.; Rascher, R.

    2015-08-01

    Precision optical components are usually machined by grinding and polishing in several steps with increasing accuracy. Spherical surfaces will be finished in a last step with large tools to smooth the surface. The requested surface accuracy of non-spherical surfaces only can be achieved with tools in point contact to the surface. So called mid-frequency errors (MSFE) can accumulate with zonal processes. This work is on the formation of surface errors from grinding to polishing by conducting an analysis of the surfaces in their machining steps by non-contact interferometric methods. The errors on the surface can be distinguished as described in DIN 4760 whereby 2nd to 3rd order errors are the so-called MSFE. By appropriate filtering of the measured data frequencies of errors can be suppressed in a manner that only defined spatial frequencies will be shown in the surface plot. It can be observed that some frequencies already may be formed in the early machining steps like grinding and main-polishing. Additionally it is known that MSFE can be produced by the process itself and other side effects. Beside a description of surface errors based on the limits of measurement technologies, different formation mechanisms for selected spatial frequencies are presented. A correction may be only possible by tools that have a lateral size below the wavelength of the error structure. The presented considerations may be used to develop proposals to handle surface errors.

  3. Wavefront error sensing

    NASA Technical Reports Server (NTRS)

    Tubbs, Eldred F.

    1986-01-01

    A two-step approach to wavefront sensing for the Large Deployable Reflector (LDR) was examined as part of an effort to define wavefront-sensing requirements and to determine particular areas for more detailed study. A Hartmann test for coarse alignment, particularly segment tilt, seems feasible if LDR can operate at 5 microns or less. The direct measurement of the point spread function in the diffraction limited region may be a way to determine piston error, but this can only be answered by a detailed software model of the optical system. The question of suitable astronomical sources for either test must also be addressed.

  4. Detecting Errors in Programs

    DTIC Science & Technology

    1979-02-01

    unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 DETECTING ERRORS IN PROGRAMS* Lloyd D. Fosdick...from a finite set of tests [35,36]a Recently Howden [37] presented a result showing that for a particular class of Lindenmayer grammars it was possible...Diego, CA. 37o Howden, W.E.: Lindenmayer grammars and symbolic testing. Information Processing Letters 7,1 (Jano 1978), 36-39. 38~ Fitzsimmons, Ann

  5. Speech Errors, Error Correction, and the Construction of Discourse.

    ERIC Educational Resources Information Center

    Linde, Charlotte

    Speech errors have been used in the construction of production models of the phonological and semantic components of language, and for a model of interactional processes. Errors also provide insight into how speakers plan discourse and syntactic structure,. Different types of discourse exhibit different types of error. The present data are taken…

  6. Spatial Displays and Spatial Instruments

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R. (Editor); Kaiser, Mary K. (Editor); Grunwald, Arthur J. (Editor)

    1989-01-01

    The conference proceedings topics are divided into two main areas: (1) issues of spatial and picture perception raised by graphical electronic displays of spatial information; and (2) design questions raised by the practical experience of designers actually defining new spatial instruments for use in new aircraft and spacecraft. Each topic is considered from both a theoretical and an applied direction. Emphasis is placed on discussion of phenomena and determination of design principles.

  7. Errors in CT colonography.

    PubMed

    Trilisky, Igor; Ward, Emily; Dachman, Abraham H

    2015-10-01

    CT colonography (CTC) is a colorectal cancer screening modality which is becoming more widely implemented and has shown polyp detection rates comparable to those of optical colonoscopy. CTC has the potential to improve population screening rates due to its minimal invasiveness, no sedation requirement, potential for reduced cathartic examination, faster patient throughput, and cost-effectiveness. Proper implementation of a CTC screening program requires careful attention to numerous factors, including patient preparation prior to the examination, the technical aspects of image acquisition, and post-processing of the acquired data. A CTC workstation with dedicated software is required with integrated CTC-specific display features. Many workstations include computer-aided detection software which is designed to decrease errors of detection by detecting and displaying polyp-candidates to the reader for evaluation. There are several pitfalls which may result in false-negative and false-positive reader interpretation. We present an overview of the potential errors in CTC and a systematic approach to avoid them.

  8. Inborn Errors in Immunity

    PubMed Central

    Lionakis, M.S.; Hajishengallis, G.

    2015-01-01

    In recent years, the study of genetic defects arising from inborn errors in immunity has resulted in the discovery of new genes involved in the function of the immune system and in the elucidation of the roles of known genes whose importance was previously unappreciated. With the recent explosion in the field of genomics and the increasing number of genetic defects identified, the study of naturally occurring mutations has become a powerful tool for gaining mechanistic insight into the functions of the human immune system. In this concise perspective, we discuss emerging evidence that inborn errors in immunity constitute real-life models that are indispensable both for the in-depth understanding of human biology and for obtaining critical insights into common diseases, such as those affecting oral health. In the field of oral mucosal immunity, through the study of patients with select gene disruptions, the interleukin-17 (IL-17) pathway has emerged as a critical element in oral immune surveillance and susceptibility to inflammatory disease, with disruptions in the IL-17 axis now strongly linked to mucosal fungal susceptibility, whereas overactivation of the same pathways is linked to inflammatory periodontitis. PMID:25900229

  9. Error Analysis in Mathematics Education.

    ERIC Educational Resources Information Center

    Rittner, Max

    1982-01-01

    The article reviews the development of mathematics error analysis as a means of diagnosing students' cognitive reasoning. Errors specific to addition, subtraction, multiplication, and division are described, and suggestions for remediation are provided. (CL)

  10. Skylab water balance error analysis

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.

    1977-01-01

    Estimates of the precision of the net water balance were obtained for the entire Skylab preflight and inflight phases as well as for the first two weeks of flight. Quantitative estimates of both total sampling errors and instrumentation errors were obtained. It was shown that measurement error is minimal in comparison to biological variability and little can be gained from improvement in analytical accuracy. In addition, a propagation of error analysis demonstrated that total water balance error could be accounted for almost entirely by the errors associated with body mass changes. Errors due to interaction between terms in the water balance equation (covariances) represented less than 10% of the total error. Overall, the analysis provides evidence that daily measurements of body water changes obtained from the indirect balance technique are reasonable, precise, and relaible. The method is not biased toward net retention or loss.

  11. Prospective issues for error detection.

    PubMed

    Blavier, Adélaïde; Rouy, Emmanuelle; Nyssen, Anne-Sophie; de Keyser, Véronique

    2005-06-10

    From the literature on error detection, the authors select several concepts relating error detection mechanisms and prospective memory features. They emphasize the central role of intention in the classification of the errors into slips/lapses/mistakes, in the error handling process and in the usual distinction between action-based and outcome-based detection. Intention is again a core concept in their investigation of prospective memory theory, where they point out the contribution of intention retrievals, intention persistence and output monitoring in the individual's possibilities for detecting their errors. The involvement of the frontal lobes in prospective memory and in error detection is also analysed. From the chronology of a prospective memory task, the authors finally suggest a model for error detection also accounting for neural mechanisms highlighted by studies on error-related brain activity.

  12. Spatial uncertainty and ecological models

    SciTech Connect

    Jager, Yetta; King, Anthony Wayne

    2004-07-01

    Applied ecological models that are used to understand and manage natural systems often rely on spatial data as input. Spatial uncertainty in these data can propagate into model predictions. Uncertainty analysis, sensitivity analysis, error analysis, error budget analysis, spatial decision analysis, and hypothesis testing using neutral models are all techniques designed to explore the relationship between variation in model inputs and variation in model predictions. Although similar methods can be used to answer them, these approaches address different questions. These approaches differ in (a) whether the focus is forward or backward (forward to evaluate the magnitude of variation in model predictions propagated or backward to rank input parameters by their influence); (b) whether the question involves model robustness to large variations in spatial pattern or to small deviations from a reference map; and (c) whether processes that generate input uncertainty (for example, cartographic error) are of interest. In this commentary, we propose a taxonomy of approaches, all of which clarify the relationship between spatial uncertainty and the predictions of ecological models. We describe existing techniques and indicate a few areas where research is needed.

  13. Quality assessment of reporting of randomization, allocation concealment, and blinding in traditional chinese medicine RCTs: A review of 3159 RCTs identified from 260 systematic reviews

    PubMed Central

    2011-01-01

    Background Randomized controlled trials (RCTs) which are of poor quality tend to exaggerate the effect estimate and lead to wrong or misleading conclusions. The aim of this study is to assess the quality of randomization methods, allocation concealment and blinding within traditional Chinese medicine (TCM) RCTs, discuss issues identified for current TCM RCTs, and provide suggestions for quality improvement. Methods We searched Chinese Biomedical Database (CBM, 1978 to July 31, 2009) and the Cochrane Library (Issue 2, 2009) to collect TCM systematic reviews and meta-analyses according to inclusion/exclusion criteria, from which RCTs could be identified. The quality assessment involved whether the randomization methods, allocation concealment and blinding were adequate or not based the study reported. Stratified analyses were conducted of different types of diseases published in different journals (both Chinese and foreign) using different interventions. SPSS 15.0 software was used for statistic analyses. Results A total of 3159 RCTs were included, of which 2580 were published in Chinese journals and 579 in foreign journals. There were 381 (12%) RCTs which used adequate randomization methods; 207 (7%) RCTs which used adequate allocation concealment and 601 (19%) which used adequate blinding; there were 130 (4%) RCTs which both used adequate randomization methods and allocation concealment; and there were only 100 (3%) RCTs which used adequate randomization methods, allocation concealment, as well as blinding. In the RCTs published in foreign journals, the adequate randomization methods, allocation concealment and blinding accounted for a relatively large proportion (25%, 26%, and 60%, respectively) and increased with years, while in the RCTs published in Chinese journals, only the adequate randomization methods improved over time. The quality of non-drug intervention (chiefly acupuncture) RCTs was higher than that of drug intervention RCTs. In drug intervention, the

  14. Error Sources in Asteroid Astrometry

    NASA Technical Reports Server (NTRS)

    Owen, William M., Jr.

    2000-01-01

    Asteroid astrometry, like any other scientific measurement process, is subject to both random and systematic errors, not all of which are under the observer's control. To design an astrometric observing program or to improve an existing one requires knowledge of the various sources of error, how different errors affect one's results, and how various errors may be minimized by careful observation or data reduction techniques.

  15. Error Patterns in Problem Solving.

    ERIC Educational Resources Information Center

    Babbitt, Beatrice C.

    Although many common problem-solving errors within the realm of school mathematics have been previously identified, a compilation of such errors is not readily available within learning disabilities textbooks, mathematics education texts, or teacher's manuals for school mathematics texts. Using data on error frequencies drawn from both the Fourth…

  16. Measurement Error. For Good Measure....

    ERIC Educational Resources Information Center

    Johnson, Stephen; Dulaney, Chuck; Banks, Karen

    No test, however well designed, can measure a student's true achievement because numerous factors interfere with the ability to measure achievement. These factors are sources of measurement error, and the goal in creating tests is to have as little measurement error as possible. Error can result from the test design, factors related to individual…

  17. Uncertainty quantification and error analysis

    SciTech Connect

    Higdon, Dave M; Anderson, Mark C; Habib, Salman; Klein, Richard; Berliner, Mark; Covey, Curt; Ghattas, Omar; Graziani, Carlo; Seager, Mark; Sefcik, Joseph; Stark, Philip

    2010-01-01

    UQ studies all sources of error and uncertainty, including: systematic and stochastic measurement error; ignorance; limitations of theoretical models; limitations of numerical representations of those models; limitations on the accuracy and reliability of computations, approximations, and algorithms; and human error. A more precise definition for UQ is suggested below.

  18. Feature Referenced Error Correction Apparatus.

    DTIC Science & Technology

    A feature referenced error correction apparatus utilizing the multiple images of the interstage level image format to compensate for positional...images and by the generation of an error correction signal in response to the sub-frame registration errors. (Author)

  19. The effect of uncertainty and systematic errors in hydrological modelling

    NASA Astrophysics Data System (ADS)

    Steinsland, I.; Engeland, K.; Johansen, S. S.; Øverleir-Petersen, A.; Kolberg, S. A.

    2014-12-01

    The aims of hydrological model identification and calibration are to find the best possible set of process parametrization and parameter values that transform inputs (e.g. precipitation and temperature) to outputs (e.g. streamflow). These models enable us to make predictions of streamflow. Several sources of uncertainties have the potential to hamper the possibility of a robust model calibration and identification. In order to grasp the interaction between model parameters, inputs and streamflow, it is important to account for both systematic and random errors in inputs (e.g. precipitation and temperatures) and streamflows. By random errors we mean errors that are independent from time step to time step whereas by systematic errors we mean errors that persists for a longer period. Both random and systematic errors are important in the observation and interpolation of precipitation and temperature inputs. Important random errors comes from the measurements themselves and from the network of gauges. Important systematic errors originate from the under-catch in precipitation gauges and from unknown spatial trends that are approximated in the interpolation. For streamflow observations, the water level recordings might give random errors whereas the rating curve contributes mainly with a systematic error. In this study we want to answer the question "What is the effect of random and systematic errors in inputs and observed streamflow on estimated model parameters and streamflow predictions?". To answer we test systematically the effect of including uncertainties in inputs and streamflow during model calibration and simulation in distributed HBV model operating on daily time steps for the Osali catchment in Norway. The case study is based on observations from, uncertainty carefullt quantified, and increased uncertainties and systmatical errors are done realistically by for example removing a precipitation gauge from the network.We find that the systematical errors in

  20. Biasing errors and corrections

    NASA Technical Reports Server (NTRS)

    Meyers, James F.

    1991-01-01

    The dependence of laser velocimeter measurement rate on flow velocity is discussed. Investigations outlining that any dependence is purely statistical, and is nonstationary both spatially and temporally, are described. Main conclusions drawn are that the times between successive particle arrivals should be routinely measured and the calculation of the velocity data rate correlation coefficient should be performed to determine if a dependency exists. If none is found, accept the data ensemble as an independent sample of the flow. If a dependency is found, the data should be modified to obtain an independent sample. Universal correcting procedures should never be applied because their underlying assumptions are not valid.

  1. On typographical errors.

    PubMed

    Hamilton, J W

    1993-09-01

    In his overall assessment of parapraxes in 1901, Freud included typographical mistakes but did not elaborate on or study this subject nor did he have anything to say about it in his later writings. This paper lists textual errors from a variety of current literary sources and explores the dynamic importance of their execution and the failure to make necessary corrections during the editorial process. While there has been a deemphasis of the role of unconscious determinants in the genesis of all slips as a result of recent findings in cognitive psychology, the examples offered suggest that, with respect to motivation, lapses in compulsivity contribute to their original commission while thematic compliance and voyeuristic issues are important in their not being discovered prior to publication.

  2. A study on heterogeneous distributed spatial information platform based on semantic Web services

    NASA Astrophysics Data System (ADS)

    Peng, Shuang-yun; Yang, Kun; Xu, Quan-li; Huang, Bang-mei

    2008-10-01

    With the development of Semantic Web technology, the spatial information service based on ontology is an effective way for sharing and interoperation of heterogeneous information resources in the distributed network environment. This paper discusses spatial information sharing and interoperability in the Semantic Web Services architecture. Through using Ontology record spatial information in sharing knowledge system, explicit and formalization expresses the default and the concealment semantic information. It provides the prerequisite for spatial information sharing and interoperability; Through Semantic Web Services technology parses Ontology and intelligent buildings services under network environment, form a network of services. In order to realize the practical applications of spatial information sharing and interoperation in different brunches of CDC system, a prototype system for HIV/AIDS information sharing based on geo-ontology has also been developed by using the methods described above.

  3. Rapid mapping of volumetric errors

    SciTech Connect

    Krulewich, D.; Hale, L.; Yordy, D.

    1995-09-13

    This paper describes a relatively inexpensive, fast, and easy to execute approach to mapping the volumetric errors of a machine tool, coordinate measuring machine, or robot. An error map is used to characterize a machine or to improve its accuracy by compensating for the systematic errors. The method consists of three steps: (1) modeling the relationship between the volumetric error and the current state of the machine; (2) acquiring error data based on length measurements throughout the work volume; and (3) optimizing the model to the particular machine.

  4. Register file soft error recovery

    DOEpatents

    Fleischer, Bruce M.; Fox, Thomas W.; Wait, Charles D.; Muff, Adam J.; Watson, III, Alfred T.

    2013-10-15

    Register file soft error recovery including a system that includes a first register file and a second register file that mirrors the first register file. The system also includes an arithmetic pipeline for receiving data read from the first register file, and error detection circuitry to detect whether the data read from the first register file includes corrupted data. The system further includes error recovery circuitry to insert an error recovery instruction into the arithmetic pipeline in response to detecting the corrupted data. The inserted error recovery instruction replaces the corrupted data in the first register file with a copy of the data from the second register file.

  5. NGC1448 and IC 3639: Two Concealed Black Holes Lurking in our Cosmic Backyard Unveiled by NuSTAR

    NASA Astrophysics Data System (ADS)

    Stern, Daniel; Boorman, Peter; Annuar, Ady; Gandhi, Poshak; Alexander, D. M.; Lansbury, George B.; Asmus, Daniel; Ballantyne, David R.; Bauer, Franz E.; Boggs, Steven E.; Brandt, W. Niel; Brightman, Murray; Christensen, Finn; Craig, William W.; Farrah, Duncan; Goulding, Andy D.; Hailey, Charles James; Harrison, Fiona; Hoenig, Sebastian; Koss, Michael; LaMassa, Stephanie M.; Masini, Alberto; Murray, Stephen S.; Ricci, Claudio; Risaliti, Guido; Rosario, David J.; Stanley, Flora; Zhang, William

    2017-01-01

    We present NuSTAR observations of two nearby Active Galactic Nuclei (AGN), NGC 1448 and IC 3639, located at distances of 12 Mpc and 54 Mpc, respectively. NuSTAR high-energy X-ray (> 10 keV) observations, combined with archival lower energy X-ray observations from Chandra and Suzaku, reveal both sources to contain heavily obscured, accreting super-massive black holes. NGC 1448 is one of the nearest luminous galaxies to the Milky Way, yet the AGN at its centre was only discovered in 2009. Using state-of-the-art models, we constrain the obscuring column density (NH) of gas concealing both AGN, finding them to be extreme, with NH values well into the Compton-thick (CT) regime with N(H) > 3e24 /cm2. NGC 1448 has an intrinsic X-ray luminosity of L(24 keV) ˜ 5e40 erg/s, making it one of the lowest luminosity CT AGN known. IC 3639, on the other hand, has one of the strongest iron fluorescence emission lines known. We also discuss multi-wavelength diagnostics at optical and mid-infrared energies as indirect indicators to penetrate through the obscuring veils and probe the intrinsic properties of the AGN. Through detailed studies such as we present here, NuSTAR is showing that there are still plenty of interesting discoveries awaiting to be made, even in the nearby Universe.

  6. Evaluation of intracardiac recordings in diagnosis of impulse formation and concealed conduction in atrioventricular nodal bypass tracts.

    PubMed Central

    Castellanos, A; Agha, A S; Mendoza, I J; Sung, R J

    1977-01-01

    Invasive electrophysiological studies were performed in 2 symptomatic patients with recurrent arrhythmias in which impulse formation presumably occured within atrioventricular nodal bypass tracts. Case 1 had ectopic beats arising within, or close to, the upper end of a left-sided atrioventricular nodal bypass tract of the type described by Brechenmacher. In addition, this conduction was 'concealed' during sinus rhythm and right atrial pacing because the relatively prolonged right-to-left atrial conduction time allowed right atrial impulses to reach the His bundle via the atrioventricular node before they could do so through the atrioventricular nodal bypass tract. Case 2 had ectopic beats arising in a right-sided atrioventricular nodal bypass tract which did not conduct in either forward or retrograde directions, its presence being detected only when initiating impulses. However, it could not be determined whether this tract was an 'abnormal' atrio-His connection or a 'normal' transitional (atrio-atrioventricular nodal) tract. Though intracardiac studies complement body surface recordings, they should be interpreted with knowledge of their inherent limitations. PMID:884022

  7. The dengue virus conceals double-stranded RNA in the intracellular membrane to escape from an interferon response

    PubMed Central

    Uchida, Leo; Espada-Murao, Lyre Anni; Takamatsu, Yuki; Okamoto, Kenta; Hayasaka, Daisuke; Yu, Fuxun; Nabeshima, Takeshi; Buerano, Corazon C.; Morita, Kouichi

    2014-01-01

    The dengue virus (DENV) circulates between humans and mosquitoes and requires no other mammals or birds for its maintenance in nature. The virus is well-adapted to humans, as reflected by high-level viraemia in patients. To investigate its high adaptability, the DENV induction of host type-I interferon (IFN) was assessed in vitro in human-derived HeLa cells and compared with that induced by the Japanese encephalitis virus (JEV), a closely related arbovirus that generally exhibits low viraemia in humans. A sustained viral spread with a poor IFN induction was observed in the DENV-infected cells, whereas the JEV infection resulted in a self-limiting and abortive infection with a high IFN induction. There was no difference between DENV and JEV double-stranded RNA (dsRNA) as IFN inducers. Instead, the dsRNA was poorly exposed in the cytosol as late as 48 h post-infection (p.i.), despite the high level of DENV replication in the infected cells. In contrast, the JEV-derived dsRNA appeared in the cytosol as early as 24 h p.i. Our results provided evidence for the first time in DENV, that concealing dsRNA in the intracellular membrane diminishes the effect of the host defence mechanism, a strategy that differs from an active suppression of IFN activity. PMID:25491663

  8. Burst packet loss concealment using multiple codebooks and comfort noise for CELP-type speech coders in wireless sensor networks.

    PubMed

    Park, Nam In; Kim, Hong Kook; Jung, Min A; Lee, Seong Ro; Choi, Seung Ho

    2011-01-01

    In this paper, a packet loss concealment (PLC) algorithm for CELP-type speech coders is proposed in order to improve the quality of decoded speech under burst packet loss conditions in a wireless sensor network. Conventional receiver-based PLC algorithms in the G.729 speech codec are usually based on speech correlation to reconstruct the decoded speech of lost frames by using parameter information obtained from the previous correctly received frames. However, this approach has difficulty in reconstructing voice onset signals since the parameters such as pitch, linear predictive coding coefficient, and adaptive/fixed codebooks of the previous frames are mostly related to silence frames. Thus, in order to reconstruct speech signals in the voice onset intervals, we propose a multiple codebook-based approach that includes a traditional adaptive codebook and a new random codebook composed of comfort noise. The proposed PLC algorithm is designed as a PLC algorithm for G.729 and its performance is then compared with that of the PLC algorithm currently employed in G.729 via a perceptual evaluation of speech quality, a waveform comparison, and a preference test under different random and burst packet loss conditions. It is shown from the experiments that the proposed PLC algorithm provides significantly better speech quality than the PLC algorithm employed in G.729 under all the test conditions.

  9. High-sensitivity and cost-effective system for infrared imaging of concealed objects in dynamic mode

    NASA Astrophysics Data System (ADS)

    Gordiyenko, E.; Yefremenko, V.; Pearson, J.; Bader, S. D.; Novosad, V.

    2005-05-01

    Novel, cost-efficient, and highly-sensitive IR imaging systems play an important role in homeland security functions. Technical limitations in the areas of sensitivity, contrast ratio, bandwidth and cost continue to constrain imaging capabilities. We have designed and prototyped a compact computer-piloted high sensitivity infrared imaging system. The device consists of infrared optics, cryostat, low-noise pre-amplifier, Analog-to-Digital hardware, feedback electronics, and unique image processing software. Important advantages of the developed system are: (i) Eight electronic channels are available for simultaneous registration of IR and visible images in multiple spectral ranges, (ii) Capability of real-time analysis such as comparing the "sensed" image with "reference" images from a database, (iii) High accuracy temperature measurement of multiple points on the image by referencing the radiation intensity from the object to a black body model, (iv) Image generation by real-time integration of images from multiple sensors operating from the visible to the terahertz range. The device was tested with a liquid-nitrogen-cooled, single-pixel HgCdTe detector for imaging in 8-12 microns range. The demonstrated examples of infrared imaging of concealed objects in static and dynamic modes include a hammer (metal head and wooden handle), plastic imitator of handguns hidden under clothes, powder in an envelope, and revealing complex wall structures under decorative plaster.

  10. [Effect of self-relevance of a non-critical item on physiological responding on the Concealed Information Test].

    PubMed

    Hanayama, Aiko; Yamamoto, Shuichi; Shibuya, Yusuke

    2011-12-01

    The effect of self-relevance of a non-critical item in the Concealed Information Test (CIT) was investigated. Respiration, skin conductance response (SCR), heart rate, and normalized pulse volume were recorded while performing the CIT using a stimulus set composed of 4 items (with one self-relevant item). Thirty participants were instructed to recognize one item as critical and the remaining items as non-critical (positive group), and 33 participants were instructed to recognize all items as non-critical (negative group). In the positive group, a differential reactivity was observed between the critical and non-critical items, despite the self-relevance of the non-critical item. In the negative group, a differential reactivity between the self-relevant and non-self-relevant items was observed for SCR only. However, when individual data were analyzed, there was a differential reactivity between self-relevant and non-self-relevant items on physiological measures other than SCR for some participants in the negative group. These results suggest that the self-relevance of a non-critical item might cause false positive results in "negative" participants, particularly when only SCR is used to assess differential reactivity.

  11. Instructions to suppress semantic memory enhances or has no effect on P300 in a concealed information test (CIT).

    PubMed

    Rosenfeld, J Peter; Ward, Anne; Drapekin, Jesse; Labkovsky, Elena; Tullman, Samuel

    2017-03-01

    The present study investigated the extent to which people can suppress semantic memory as indexed with the P300 ERP and the autobiographical implicit association test (aIAT). In EXP 1, participants (22) were run in a counterbalanced repeated measures study in both simply knowledgeable (SK) and knowledgeable with suppression (SP) conditions. A P300-based, concealed information test ("Complex Trial Protocol"; CTP) with a 50/50 Target/Nontarget (T/NT) ratio was given both with and without instructions to suppress semantic memories. The results showed increased P300s to probe name stimuli, reduced (but still high positive) aIAT d-scores, and increased simple reaction times to all stimuli used in ERP tests in the SP condition. EXP 2 was similar, but with SP and SK in two separate groups, and a 20/80 T/NT ratio. Again, ERP and aIAT results failed to show a suppression effect for semantic memory. The behavioral data suggest some task demand effects under suppression instructions, and that EXP 1 was more demanding than EXP 2.

  12. Archaeology of Archaea: geomicrobiological record of Pleistocene thermal events concealed in a deep-sea subseafloor environment.

    PubMed

    Inagaki, F; Takai, K; Komatsu, T; Kanamatsu, T; Fujioka, K; Horikoshi, K

    2001-12-01

    A record of the history of the Earth is hidden in the Earth's crust, like the annual rings of an old tree. From very limited records retrieved from deep underground, one can infer the geographical, geological, and biological events that occurred throughout Earth's history. Here we report the discovery of vertically shifted community structures of Archaea in a typical oceanic subseafloor core sample (1410 cm long) recovered from the West Philippine Basin at a depth of 5719 m. Beneath a surface community of ubiquitous deep-sea archaea (marine crenarchaeotic group I; MGI), an unusual archaeal community consisting of extremophilic archaea, such as extreme halophiles and hyperthermophiles, was present. These organisms could not be cultivated, and may be microbial relicts more than 2 million years old. Our discovery of archaeal rDNA in this core sample, probably associated with the past terrestrial volcanic and submarine hydrothermal activities surrounding the West Philippine Basin, serves as potential geomicrobiological evidence reflecting novel records of geologic thermal events in the Pleistocene period concealed in the deep-sea subseafloor.

  13. Recognition of partially concealed leopards by wild bonnet macaques (Macaca radiata). The role of the spotted coat.

    PubMed

    Coss, Richard G; Ramakrishnan, Uma; Schank, Jeffrey

    2005-02-28

    Wild bonnet macaques (Macaca radiata) have been shown to recognize models of leopards (Panthera pardus), based on their configuration and spotted yellow coat. This study examined whether bonnet macaques could recognize the spotted and dark melanic morph when partially concealed by vegetation. Seven troops were studied at two sites in southern India, the Mudumalai Wildlife Sanctuary and the Kalakad-Mundanthurai Tiger Reserve. The forequarters and hindquarters of the two leopard morphs were presented from behind thick vegetation to individuals at feeding stations 25 m away. Flight reaction times and frequency of flight were obtained from video for only those individuals who oriented towards the models prior to hearing alarm calls. Bonnet macaques exhibited faster reaction times and greater frequency of flight after looking at the spotted morph's forequarter than after looking at either its spotted hindquarter or the dark morph's forequarter. The hindquarter of the dark morph was ignored completely. Artificial neural network modeling examined the perceptual aspects of leopard face recognition and the role of spots as camouflage. When spots were integrated into the pattern recognition process via network training, these spots contributed to leopard face recognition. When networks were not trained with spots, spots did not act as camouflage by disrupting facial features.

  14. Towards error-free interaction.

    PubMed

    Tsoneva, Tsvetomira; Bieger, Jordi; Garcia-Molina, Gary

    2010-01-01

    Human-machine interaction (HMI) relies on pat- tern recognition algorithms that are not perfect. To improve the performance and usability of these systems we can utilize the neural mechanisms in the human brain dealing with error awareness. This study aims at designing a practical error detection algorithm using electroencephalogram signals that can be integrated in an HMI system. Thus, real-time operation, customization, and operation convenience are important. We address these requirements in an experimental framework simulating machine errors. Our results confirm the presence of brain potentials related to processing of machine errors. These are used to implement an error detection algorithm emphasizing the differences in error processing on a per subject basis. The proposed algorithm uses the individual best bipolar combination of electrode sites and requires short calibration. The single-trial error detection performance on six subjects, characterized by the area under the ROC curve ranges from 0.75 to 0.98.

  15. Sampling Errors in Satellite-derived Infrared Sea Surface Temperatures

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Minnett, P. J.

    2014-12-01

    Sea Surface Temperature (SST) measured from satellites has been playing a crucial role in understanding geophysical phenomena. Generating SST Climate Data Records (CDRs) is considered to be the one that imposes the most stringent requirements on data accuracy. For infrared SSTs, sampling uncertainties caused by cloud presence and persistence generate errors. In addition, for sensors with narrow swaths, the swath gap will act as another sampling error source. This study is concerned with quantifying and understanding such sampling errors, which are important for SST CDR generation and for a wide range of satellite SST users. In order to quantify these errors, a reference Level 4 SST field (Multi-scale Ultra-high Resolution SST) is sampled by using realistic swath and cloud masks of Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Along Track Scanning Radiometer (AATSR). Global and regional SST uncertainties are studied by assessing the sampling error at different temporal and spatial resolutions (7 spatial resolutions from 4 kilometers to 5.0° at the equator and 5 temporal resolutions from daily to monthly). Global annual and seasonal mean sampling errors are large in the high latitude regions, especially the Arctic, and have geographical distributions that are most likely related to stratus clouds occurrence and persistence. The region between 30°N and 30°S has smaller errors compared to higher latitudes, except for the Tropical Instability Wave area, where persistent negative errors are found. Important differences in sampling errors are also found between the broad and narrow swath scan patterns and between day and night fields. This is the first time that realistic magnitudes of the sampling errors are quantified. Future improvement in the accuracy of SST products will benefit from this quantification.

  16. Indium Nitride: A New Material for High Efficiency, Compact, 1550NM Laser-Based Terahertz Sources in Explosives Detection and Concealed Weapons Imaging

    DTIC Science & Technology

    2006-11-01

    INDIUM NITRIDE: A NEW MATERIAL FOR HIGH EFFICIENCY, COMPACT, 1550NM LASER-BASED TERAHERTZ SOURCES IN EXPLOSIVES DETECTION AND CONCEALED WEAPONS...nitride (InN) is identified as a promising terahertz (THz) emitter based on the optical and electronic properties of high quality In- and N-face...significant improvements in THz emitters. 1. INTRODUCTION The terahertz region of the electromagnetic spectrum, lying between microwave frequencies

  17. The "good cop, bad cop" effect in the RT-based concealed information test: exploring the effect of emotional expressions displayed by a virtual investigator.

    PubMed

    Varga, Mihai; Visu-Petra, George; Miclea, Mircea; Visu-Petra, Laura

    2015-01-01

    Concealing the possession of relevant information represents a complex cognitive process, shaped by contextual demands and individual differences in cognitive and socio-emotional functioning. The Reaction Time-based Concealed Information Test (RT-CIT) is used to detect concealed knowledge based on the difference in RTs between denying recognition of critical (probes) and newly encountered (irrelevant) information. Several research questions were addressed in this scenario implemented after a mock crime. First, we were interested whether the introduction of a social stimulus (facial identity) simulating a virtual investigator would facilitate the process of deception detection. Next, we explored whether his emotional displays (friendly, hostile or neutral) would have a differential impact on speed of responses to probe versus irrelevant items. We also compared the impact of introducing similar stimuli in a working memory (WM) updating context without requirements to conceal information. Finally, we explored the association between deceptive behavior and individual differences in WM updating proficiency or in internalizing problems (state / trait anxiety and depression). Results indicated that the mere presence of a neutral virtual investigator slowed down participants' responses, but not the appended lie-specific time (difference between probes and irrelevants). Emotional expression was shown to differentially affect speed of responses to critical items, with positive displays from the virtual examiner enhancing lie-specific time, compared to negative facial expressions, which had an opposite impact. This valence-specific effect was not visible in the WM updating context. Higher levels of trait / state anxiety were related to faster responses to probes in the negative condition (hostile facial expression) of the RT-CIT. These preliminary findings further emphasize the need to take into account motivational and emotional factors when considering the transfer of

  18. The “Good Cop, Bad Cop” Effect in the RT-Based Concealed Information Test: Exploring the Effect of Emotional Expressions Displayed by a Virtual Investigator

    PubMed Central

    Varga, Mihai; Visu-Petra, George; Miclea, Mircea; Visu-Petra, Laura

    2015-01-01

    Concealing the possession of relevant information represents a complex cognitive process, shaped by contextual demands and individual differences in cognitive and socio-emotional functioning. The Reaction Time-based Concealed Information Test (RT-CIT) is used to detect concealed knowledge based on the difference in RTs between denying recognition of critical (probes) and newly encountered (irrelevant) information. Several research questions were addressed in this scenario implemented after a mock crime. First, we were interested whether the introduction of a social stimulus (facial identity) simulating a virtual investigator would facilitate the process of deception detection. Next, we explored whether his emotional displays (friendly, hostile or neutral) would have a differential impact on speed of responses to probe versus irrelevant items. We also compared the impact of introducing similar stimuli in a working memory (WM) updating context without requirements to conceal information. Finally, we explored the association between deceptive behavior and individual differences in WM updating proficiency or in internalizing problems (state / trait anxiety and depression). Results indicated that the mere presence of a neutral virtual investigator slowed down participants' responses, but not the appended lie-specific time (difference between probes and irrelevants). Emotional expression was shown to differentially affect speed of responses to critical items, with positive displays from the virtual examiner enhancing lie-specific time, compared to negative facial expressions, which had an opposite impact. This valence-specific effect was not visible in the WM updating context. Higher levels of trait / state anxiety were related to faster responses to probes in the negative condition (hostile facial expression) of the RT-CIT. These preliminary findings further emphasize the need to take into account motivational and emotional factors when considering the transfer of

  19. Sulfur-containing particles emitted by concealed sulfide ore deposits: an unknown source of sulfur-containing particles in the atmosphere

    NASA Astrophysics Data System (ADS)

    Cao, J. J.; Li, Y. K.; Jiang, T.; Hu, G.

    2015-06-01

    Sources of sulfur dioxide, sulfates, and organic sulfur compounds, such as fossil fuels, volcanic eruptions, and animal feeding operations, have attracted considerable attention. In this study, we collected particles carried by geogas flows ascending through soil, geogas flows above the soil that had passed through the soil, and geogas flows ascending through deep faults of concealed sulfide ore deposits, and analysed them using transmission electron microscopy. Numerous crystalline and amorphous sulfur-containing particles or particle aggregations were found in the ascending geogas flows. In addition to S, the particles contained O, Ca, K, Mg, Fe, Na, Pb, Hg, Cu, Zn, As, Ti, Sr, Ba, Si, etc. Such particles are usually a few to several hundred nanometres in diameter with either regular or irregular morphology. The sulfur-containing particles originated from deep-seated weathering or faulting products of concealed sulfide ore deposits. The particles suspended in the ascending geogas flow migrated through faults from deep-seated sources to the atmosphere. This is a previously unknown source of the atmospheric particles. This paper reports, for the first time, the emission of sulfur-containing particles into the atmosphere from concealed sulfide ore deposits. The climatic and ecological influences of these sulfur-containing particles and particle aggregations should be assessed.

  20. Sulfur-containing particles emitted by concealed sulfide ore deposits: an unknown source of sulfur-containing particles in the atmosphere

    NASA Astrophysics Data System (ADS)

    Cao, J.; Li, Y.; Jiang, T.; Hu, G.

    2014-11-01

    Sources of sulfur dioxide, sulfates, and organic sulfur compounds, such as fossil fuels, volcanic eruptions, and animal feeding operations, have attracted considerable attention. In this study, we collected particles carried by geogas flows ascending through soil, geogas flows above the soil that had passed through the soil, and geogas flows ascending through deep faults of concealed sulfide ore deposits and analyzed them using transmission electron microscopy. Numerous crystalline and amorphous sulfur-containing particles or particle aggregations were found in the ascending geogas flows. In addition to S, the particles contained O, Ca, K, Mg, Fe, Na, Pb, Hg, Cu, Zn, As, Ti, Sr, Ba, Si, etc. Such particles are usually a few to several hundred nanometers in diameter with either regular or irregular morphology. The sulfur-containing particles originated from deep-seated weathering or faulting products of concealed sulfide ore deposits. The particles suspended in the ascending geogas flow migrated through faults from deep-seated sources to the atmosphere. This is a previously unknown source of the atmospheric particles. This paper reports, for the first time, the emission of sulfur-containing particles into the atmosphere from concealed sulfide ore deposits. The climatic and ecological influences of these sulfur-containing particles and particle aggregations should to be assessed.

  1. Improved Error Thresholds for Measurement-Free Error Correction

    NASA Astrophysics Data System (ADS)

    Crow, Daniel; Joynt, Robert; Saffman, M.

    2016-09-01

    Motivated by limitations and capabilities of neutral atom qubits, we examine whether measurement-free error correction can produce practical error thresholds. We show that this can be achieved by extracting redundant syndrome information, giving our procedure extra fault tolerance and eliminating the need for ancilla verification. The procedure is particularly favorable when multiqubit gates are available for the correction step. Simulations of the bit-flip, Bacon-Shor, and Steane codes indicate that coherent error correction can produce threshold error rates that are on the order of 10-3 to 10-4—comparable with or better than measurement-based values, and much better than previous results for other coherent error correction schemes. This indicates that coherent error correction is worthy of serious consideration for achieving protected logical qubits.

  2. Improved Error Thresholds for Measurement-Free Error Correction.

    PubMed

    Crow, Daniel; Joynt, Robert; Saffman, M

    2016-09-23

    Motivated by limitations and capabilities of neutral atom qubits, we examine whether measurement-free error correction can produce practical error thresholds. We show that this can be achieved by extracting redundant syndrome information, giving our procedure extra fault tolerance and eliminating the need for ancilla verification. The procedure is particularly favorable when multiqubit gates are available for the correction step. Simulations of the bit-flip, Bacon-Shor, and Steane codes indicate that coherent error correction can produce threshold error rates that are on the order of 10^{-3} to 10^{-4}-comparable with or better than measurement-based values, and much better than previous results for other coherent error correction schemes. This indicates that coherent error correction is worthy of serious consideration for achieving protected logical qubits.

  3. Comparison of analytical error and sampling error for contaminated soil.

    PubMed

    Gustavsson, Björn; Luthbom, Karin; Lagerkvist, Anders

    2006-11-16

    Investigation of soil from contaminated sites requires several sample handling steps that, most likely, will induce uncertainties in the sample. The theory of sampling describes seven sampling errors that can be calculated, estimated or discussed in order to get an idea of the size of the sampling uncertainties. With the aim of comparing the size of the analytical error to the total sampling error, these seven errors were applied, estimated and discussed, to a case study of a contaminated site. The manageable errors were summarized, showing a range of three orders of magnitudes between the examples. The comparisons show that the quotient between the total sampling error and the analytical error is larger than 20 in most calculation examples. Exceptions were samples taken in hot spots, where some components of the total sampling error get small and the analytical error gets large in comparison. Low concentration of contaminant, small extracted sample size and large particles in the sample contribute to the extent of uncertainty.

  4. Evolution of cooperation in spatially structured populations

    PubMed

    Brauchli; Killingback; Doebeli

    1999-10-21

    Using a spatial lattice model of the Iterated Prisoner's Dilemma we studied the evolution of cooperation within the strategy space of all stochastic strategies with a memory of one round. Comparing the spatial model with a randomly mixed model showed that (1) there is more cooperative behaviour in a spatially structured population, (2) PAVLOV and generous variants of it are very successful strategies in the spatial context and (3) in spatially structured populations evolution is much less chaotic than in unstructured populations. In spatially structured populations, generous variants of PAVLOV are found to be very successful strategies in playing the Iterated Prisoner's Dilemma. The main weakness of PAVLOV is that it is exploitable by defective strategies. In a spatial context this disadvantage is much less important than the good error correction of PAVLOV, and especially of generous PAVLOV, because in a spatially structured population successful strategies always build clusters. Copyright 1999 Academic Press.

  5. Dopamine reward prediction error coding.

    PubMed

    Schultz, Wolfram

    2016-03-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.

  6. Dopamine reward prediction error coding

    PubMed Central

    Schultz, Wolfram

    2016-01-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards—an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware. PMID:27069377

  7. Handwriting Error Patterns of Children with Mild Motor Difficulties.

    ERIC Educational Resources Information Center

    Malloy-Miller, Theresa; And Others

    1995-01-01

    A test of handwriting legibility and 6 perceptual-motor tests were completed by 66 children ages 7-12. Among handwriting error patterns, execution was associated with visual-motor skill and sensory discrimination, aiming with visual-motor and fine-motor skills. The visual-spatial factor had no significant association with perceptual-motor…

  8. Processor register error correction management

    SciTech Connect

    Bose, Pradip; Cher, Chen-Yong; Gupta, Meeta S.

    2016-12-27

    Processor register protection management is disclosed. In embodiments, a method of processor register protection management can include determining a sensitive logical register for executable code generated by a compiler, generating an error-correction table identifying the sensitive logical register, and storing the error-correction table in a memory accessible by a processor. The processor can be configured to generate a duplicate register of the sensitive logical register identified by the error-correction table.

  9. The impact of sound speed errors on medical ultrasound imaging.

    PubMed

    Anderson, M E; McKeag, M S; Trahey, G E

    2000-06-01

    The results of a quantitative study of the impact of sound speed errors on the spatial resolution and amplitude sensitivity of a commercial medical ultrasound scanner are presented in the context of their clinical significance. The beamforming parameters of the scanner were manipulated to produce sound speed errors ranging over +/-8% while imaging a wire target and an attenuating, speckle-generating phantom. For the wire target, these errors produced increases in lateral beam width of up to 320% and reductions in peak echo amplitude of up to 10.5 dB. In the speckle-generating phantom, these errors produced increases in speckle intensity correlation cell area of up to 92% and reductions in mean speckle brightness of up to 5.6 dB. These results are applied in statistical analyses of two detection tasks of clinical relevance. The first is of low contrast lesion detectability, predicting the changes in the correct decision probability as a function of lesion size, contrast, and sound speed error. The second is of point target detectability, predicting the changes in the correct decision probability as function of point target reflectivity and sound speed error. Representative results of these analyses are presented and their implications for clinical imaging are discussed. In general, sound speed errors have a more significant impact on point target detectability over lesion detectability by these analyses, producing up to a 22% reduction in correct decisions for a typical error.

  10. Compensating For GPS Ephemeris Error

    NASA Technical Reports Server (NTRS)

    Wu, Jiun-Tsong

    1992-01-01

    Method of computing position of user station receiving signals from Global Positioning System (GPS) of navigational satellites compensates for most of GPS ephemeris error. Present method enables user station to reduce error in its computed position substantially. User station must have access to two or more reference stations at precisely known positions several hundred kilometers apart and must be in neighborhood of reference stations. Based on fact that when GPS data used to compute baseline between reference station and user station, vector error in computed baseline is proportional ephemeris error and length of baseline.

  11. A theory of human error

    NASA Technical Reports Server (NTRS)

    Mcruer, D. T.; Clement, W. F.; Allen, R. W.

    1980-01-01

    Human error, a significant contributing factor in a very high proportion of civil transport, general aviation, and rotorcraft accidents is investigated. Correction of the sources of human error requires that one attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation operations is presented. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.

  12. Confidence limits and their errors

    SciTech Connect

    Rajendran Raja

    2002-03-22

    Confidence limits are common place in physics analysis. Great care must be taken in their calculation and use especially in cases of limited statistics. We introduce the concept of statistical errors of confidence limits and argue that not only should limits be calculated but also their errors in order to represent the results of the analysis to the fullest. We show that comparison of two different limits from two different experiments becomes easier when their errors are also quoted. Use of errors of confidence limits will lead to abatement of the debate on which method is best suited to calculate confidence limits.

  13. Measurement Error and Equating Error in Power Analysis

    ERIC Educational Resources Information Center

    Phillips, Gary W.; Jiang, Tao

    2016-01-01

    Power analysis is a fundamental prerequisite for conducting scientific research. Without power analysis the researcher has no way of knowing whether the sample size is large enough to detect the effect he or she is looking for. This paper demonstrates how psychometric factors such as measurement error and equating error affect the power of…

  14. Correcting numerical integration errors caused by small aliasing errors

    SciTech Connect

    Smallwood, D.O.

    1997-11-01

    Small sampling errors can have a large effect on numerically integrated waveforms. An example is the integration of acceleration to compute velocity and displacement waveforms. These large integration errors complicate checking the suitability of the acceleration waveform for reproduction on shakers. For waveforms typically used for shaker reproduction, the errors become significant when the frequency content of the waveform spans a large frequency range. It is shown that these errors are essentially independent of the numerical integration method used, and are caused by small aliasing errors from the frequency components near the Nyquist frequency. A method to repair the integrated waveforms is presented. The method involves using a model of the acceleration error, and fitting this model to the acceleration, velocity, and displacement waveforms to force the waveforms to fit the assumed initial and final values. The correction is then subtracted from the acceleration before integration. The method is effective where the errors are isolated to a small section of the time history. It is shown that the common method to repair these errors using a high pass filter is sometimes ineffective for this class of problem.

  15. Anxiety and Error Monitoring: Increased Error Sensitivity or Altered Expectations?

    ERIC Educational Resources Information Center

    Compton, Rebecca J.; Carp, Joshua; Chaddock, Laura; Fineman, Stephanie L.; Quandt, Lorna C.; Ratliff, Jeffrey B.

    2007-01-01

    This study tested the prediction that the error-related negativity (ERN), a physiological measure of error monitoring, would be enhanced in anxious individuals, particularly in conditions with threatening cues. Participants made gender judgments about faces whose expressions were either happy, angry, or neutral. Replicating prior studies, midline…

  16. Error propagation in energetic carrying capacity models

    USGS Publications Warehouse

    Pearse, Aaron T.; Stafford, Joshua D.

    2014-01-01

    Conservation objectives derived from carrying capacity models have been used to inform management of landscapes for wildlife populations. Energetic carrying capacity models are particularly useful in conservation planning for wildlife; these models use estimates of food abundance and energetic requirements of wildlife to target conservation actions. We provide a general method for incorporating a foraging threshold (i.e., density of food at which foraging becomes unprofitable) when estimating food availability with energetic carrying capacity models. We use a hypothetical example to describe how past methods for adjustment of foraging thresholds biased results of energetic carrying capacity models in certain instances. Adjusting foraging thresholds at the patch level of the species of interest provides results consistent with ecological foraging theory. Presentation of two case studies suggest variation in bias which, in certain instances, created large errors in conservation objectives and may have led to inefficient allocation of limited resources. Our results also illustrate how small errors or biases in application of input parameters, when extrapolated to large spatial extents, propagate errors in conservation planning and can have negative implications for target populations.

  17. Examining Effects of Anticipated Stigma, Centrality, Salience, Internalization, and Outness on Psychological Distress for People with Concealable Stigmatized Identities

    PubMed Central

    Quinn, Diane M.; Williams, Michelle K.; Quintana, Francisco; Gaskins, Jennifer L.; Overstreet, Nicole M.; Pishori, Alefiyah; Earnshaw, Valerie A.; Perez, Giselle; Chaudoir, Stephenie R.

    2014-01-01

    Understanding how stigmatized identities contribute to increased rates of depression and anxiety is critical to stigma reduction and mental health treatment. There has been little research testing multiple aspects of stigmatized identities simultaneously. In the current study, we collected data from a diverse, urban, adult community sample of people with a concealed stigmatized identity (CSI). We targeted 5 specific CSIs – mental illness, substance abuse, experience of domestic violence, experience of sexual assault, and experience of childhood abuse – that have been shown to put people at risk for increased psychological distress. We collected measures of the anticipation of being devalued by others if the identity became known (anticipated stigma), the level of defining oneself by the stigmatized identity (centrality), the frequency of thinking about the identity (salience), the extent of agreement with negative stereotypes about the identity (internalized stigma), and extent to which other people currently know about the identity (outness). Results showed that greater anticipated stigma, greater identity salience, and lower levels of outness each uniquely and significantly predicted variance in increased psychological distress (a composite of depression and anxiety). In examining communalities and differences across the five identities, we found that mean levels of the stigma variables differed across the identities, with people with substance abuse and mental illness reporting greater anticipated and internalized stigma. However, the prediction pattern of the variables for psychological distress was similar across the substance abuse, mental illness, domestic violence, and childhood abuse identities (but not sexual assault). Understanding which components of stigmatized identities predict distress can lead to more effective treatment for people experiencing psychological distress. PMID:24817189

  18. Examining effects of anticipated stigma, centrality, salience, internalization, and outness on psychological distress for people with concealable stigmatized identities.

    PubMed

    Quinn, Diane M; Williams, Michelle K; Quintana, Francisco; Gaskins, Jennifer L; Overstreet, Nicole M; Pishori, Alefiyah; Earnshaw, Valerie A; Perez, Giselle; Chaudoir, Stephenie R

    2014-01-01

    Understanding how stigmatized identities contribute to increased rates of depression and anxiety is critical to stigma reduction and mental health treatment. There has been little research testing multiple aspects of stigmatized identities simultaneously. In the current study, we collected data from a diverse, urban, adult community sample of people with a concealed stigmatized identity (CSI). We targeted 5 specific CSIs--mental illness, substance abuse, experience of domestic violence, experience of sexual assault, and experience of childhood abuse--that have been shown to put people at risk for increased psychological distress. We collected measures of the anticipation of being devalued by others if the identity became known (anticipated stigma), the level of defining oneself by the stigmatized identity (centrality), the frequency of thinking about the identity (salience), the extent of agreement with negative stereotypes about the identity (internalized stigma), and extent to which other people currently know about the identity (outness). Results showed that greater anticipated stigma, greater identity salience, and lower levels of outness each uniquely and significantly predicted variance in increased psychological distress (a composite of depression and anxiety). In examining communalities and differences across the five identities, we found that mean levels of the stigma variables differed across the identities, with people with substance abuse and mental illness reporting greater anticipated and internalized stigma. However, the prediction pattern of the variables for psychological distress was similar across the substance abuse, mental illness, domestic violence, and childhood abuse identities (but not sexual assault). Understanding which components of stigmatized identities predict distress can lead to more effective treatment for people experiencing psychological distress.

  19. Error studies for SNS Linac. Part 1: Transverse errors

    SciTech Connect

    Crandall, K.R.

    1998-12-31

    The SNS linac consist of a radio-frequency quadrupole (RFQ), a drift-tube linac (DTL), a coupled-cavity drift-tube linac (CCDTL) and a coupled-cavity linac (CCL). The RFQ and DTL are operated at 402.5 MHz; the CCDTL and CCL are operated at 805 MHz. Between the RFQ and DTL is a medium-energy beam-transport system (MEBT). This error study is concerned with the DTL, CCDTL and CCL, and each will be analyzed separately. In fact, the CCL is divided into two sections, and each of these will be analyzed separately. The types of errors considered here are those that affect the transverse characteristics of the beam. The errors that cause the beam center to be displaced from the linac axis are quad displacements and quad tilts. The errors that cause mismatches are quad gradient errors and quad rotations (roll).

  20. Dose calibration optimization and error propagation in polymer gel dosimetry

    NASA Astrophysics Data System (ADS)

    Jirasek, A.; Hilts, M.

    2014-02-01

    This study reports on the relative precision, relative error, and dose differences observed when using a new full-image calibration technique in NIPAM-based x-ray CT polymer gel dosimetry. The effects of calibration parameters (e.g. gradient thresholding, dose bin size, calibration fit function, and spatial remeshing) on subsequent errors in calibrated gel images are reported. It is found that gradient thresholding, dose bin size, and fit function all play a primary role in affecting errors in calibrated images. Spatial remeshing induces minimal reductions or increases in errors in calibrated images. This study also reports on a full error propagation throughout the CT gel image pre-processing and calibration procedure thus giving, for the first time, a realistic view of the errors incurred in calibrated CT polymer gel dosimetry. While the work is based on CT polymer gel dosimetry, the formalism is valid for and easily extended to MRI or optical CT dosimetry protocols. Hence, the procedures developed within the work are generally applicable to calibration of polymer gel dosimeters.

  1. Error begat error: design error analysis and prevention in social infrastructure projects.

    PubMed

    Love, Peter E D; Lopez, Robert; Edwards, David J; Goh, Yang M

    2012-09-01

    Design errors contribute significantly to cost and schedule growth in social infrastructure projects and to engineering failures, which can result in accidents and loss of life. Despite considerable research that has addressed their error causation in construction projects they still remain prevalent. This paper identifies the underlying conditions that contribute to design errors in social infrastructure projects (e.g. hospitals, education, law and order type buildings). A systemic model of error causation is propagated and subsequently used to develop a learning framework for design error prevention. The research suggests that a multitude of strategies should be adopted in congruence to prevent design errors from occurring and so ensure that safety and project performance are ameliorated.

  2. Left neglect dyslexia: Perseveration and reading error types.

    PubMed

    Ronchi, Roberta; Algeri, Lorella; Chiapella, Laura; Gallucci, Marcello; Spada, Maria Simonetta; Vallar, Giuseppe

    2016-08-01

    Right-brain-damaged patients may show a reading disorder termed neglect dyslexia. Patients with left neglect dyslexia omit letters on the left-hand-side (the beginning, when reading left-to-right) part of the letter string, substitute them with other letters, and add letters to the left of the string. The aim of this study was to investigate the pattern of association, if any, between error types in patients with left neglect dyslexia and recurrent perseveration (a productive visuo-motor deficit characterized by addition of marks) in target cancellation. Specifically, we aimed at assessing whether different productive symptoms (relative to the reading and the visuo-motor domains) could be associated in patients with left spatial neglect. Fifty-four right-brain-damaged patients took part in the study: 50 out of the 54 patients showed left spatial neglect, with 27 of them also exhibiting left neglect dyslexia. Neglect dyslexic patients who showed perseveration produced mainly substitution neglect errors in reading. Conversely, omissions were the prevailing reading error pattern in neglect dyslexic patients without perseveration. Addition reading errors were much infrequent. Different functional pathological mechanisms may underlie omission and substitution reading errors committed by right-brain-damaged patients with left neglect dyslexia. One such mechanism, involving the defective stopping of inappropriate responses, may contribute to both recurrent perseveration in target cancellation, and substitution errors in reading. Productive pathological phenomena, together with deficits of spatial attention to events taking place on the left-hand-side of space, shape the manifestations of neglect dyslexia, and, more generally, of spatial neglect.

  3. Children's Scale Errors with Tools

    ERIC Educational Resources Information Center

    Casler, Krista; Eshleman, Angelica; Greene, Kimberly; Terziyan, Treysi

    2011-01-01

    Children sometimes make "scale errors," attempting to interact with tiny object replicas as though they were full size. Here, we demonstrate that instrumental tools provide special insight into the origins of scale errors and, moreover, into the broader nature of children's purpose-guided reasoning and behavior with objects. In Study 1, 1.5- to…

  4. Dual Processing and Diagnostic Errors

    ERIC Educational Resources Information Center

    Norman, Geoff

    2009-01-01

    In this paper, I review evidence from two theories in psychology relevant to diagnosis and diagnostic errors. "Dual Process" theories of thinking, frequently mentioned with respect to diagnostic error, propose that categorization decisions can be made with either a fast, unconscious, contextual process called System 1 or a slow, analytical,…

  5. Explaining Errors in Children's Questions

    ERIC Educational Resources Information Center

    Rowland, Caroline F.

    2007-01-01

    The ability to explain the occurrence of errors in children's speech is an essential component of successful theories of language acquisition. The present study tested some generativist and constructivist predictions about error on the questions produced by ten English-learning children between 2 and 5 years of age. The analyses demonstrated that,…

  6. Error Estimates for Mixed Methods.

    DTIC Science & Technology

    1979-03-01

    This paper presents abstract error estimates for mixed methods for the approximate solution of elliptic boundary value problems. These estimates are...then applied to obtain quasi-optimal error estimates in the usual Sobolev norms for four examples: three mixed methods for the biharmonic problem and a mixed method for 2nd order elliptic problems. (Author)

  7. Operational Interventions to Maintenance Error

    NASA Technical Reports Server (NTRS)

    Kanki, Barbara G.; Walter, Diane; Dulchinos, VIcki

    1997-01-01

    A significant proportion of aviation accidents and incidents are known to be tied to human error. However, research of flight operational errors has shown that so-called pilot error often involves a variety of human factors issues and not a simple lack of individual technical skills. In aircraft maintenance operations, there is similar concern that maintenance errors which may lead to incidents and accidents are related to a large variety of human factors issues. Although maintenance error data and research are limited, industry initiatives involving human factors training in maintenance have become increasingly accepted as one type of maintenance error intervention. Conscientious efforts have been made in re-inventing the team7 concept for maintenance operations and in tailoring programs to fit the needs of technical opeRAtions. Nevertheless, there remains a dual challenge: 1) to develop human factors interventions which are directly supported by reliable human error data, and 2) to integrate human factors concepts into the procedures and practices of everyday technical tasks. In this paper, we describe several varieties of human factors interventions and focus on two specific alternatives which target problems related to procedures and practices; namely, 1) structured on-the-job training and 2) procedure re-design. We hope to demonstrate that the key to leveraging the impact of these solutions comes from focused interventions; that is, interventions which are derived from a clear understanding of specific maintenance errors, their operational context and human factors components.

  8. Error Correction, Revision, and Learning

    ERIC Educational Resources Information Center

    Truscott, John; Hsu, Angela Yi-ping

    2008-01-01

    Previous research has shown that corrective feedback on an assignment helps learners reduce their errors on that assignment during the revision process. Does this finding constitute evidence that learning resulted from the feedback? Differing answers play an important role in the ongoing debate over the effectiveness of error correction,…

  9. Human Error: A Concept Analysis

    NASA Technical Reports Server (NTRS)

    Hansen, Frederick D.

    2007-01-01

    Human error is the subject of research in almost every industry and profession of our times. This term is part of our daily language and intuitively understood by most people however, it would be premature to assume that everyone's understanding of human error s the same. For example, human error is used to describe the outcome or consequence of human action, the causal factor of an accident, deliberate violations,a nd the actual action taken by a human being. As a result, researchers rarely agree on the either a specific definition or how to prevent human error. The purpose of this article is to explore the specific concept of human error using Concept Analysis as described by Walker and Avant (1995). The concept of human error is examined as currently used in the literature of a variety of industries and professions. Defining attributes and examples of model, borderline, and contrary cases are described. The antecedents and consequences of human error are also discussed and a definition of human error is offered.

  10. Twenty questions about student errors

    NASA Astrophysics Data System (ADS)

    Fisher, Kathleen M.; Lipson, Joseph Isaac

    Errors in science learning (errors in expression of organized, purposeful thought within the domain of science) provide a window through which glimpses of mental functioning can be obtained. Errors are valuable and normal occurrences in the process of learning science. A student can use his/her errors to develop a deeper understanding of a concept as long as the error can be recognized and appropriate, informative feedback can be obtained. A safe, non-threatening, and nonpunitive environment which encourages dialogue helps students to express their conceptions and to risk making errors. Pedagogical methods that systematically address common student errors produce significant gains in student learning. Just as the nature-nurture interaction is integral to the development of living things, so the individual-environment interaction is basic to thought processes. At a minimum, four systems interact: (1) the individual problem solver (who has a worldview, relatively stable cognitive characteristics, relatively malleable mental states and conditions, and aims or intentions), (2) task to be performed (including relative importance and nature of the task), (3) knowledge domain in which task is contained, and (4) the environment (including orienting conditions and the social and physical context).Several basic assumptions underlie research on errors and alternative conceptions. Among these are: Knowledge and thought involve active, constructive processes; there are many ways to acquire, organize, store, retrieve, and think about a given concept or event; and understanding is achieved by successive approximations. Application of these ideas will require a fundamental change in how science is taught.

  11. Onorbit IMU alignment error budget

    NASA Technical Reports Server (NTRS)

    Corson, R. W.

    1980-01-01

    The Star Tracker, Crew Optical Alignment Sight (COAS), and Inertial Measurement Unit (IMU) from a complex navigation system with a multitude of error sources were combined. A complete list of the system errors is presented. The errors were combined in a rational way to yield an estimate of the IMU alignment accuracy for STS-1. The expected standard deviation in the IMU alignment error for STS-1 type alignments was determined to be 72 arc seconds per axis for star tracker alignments and 188 arc seconds per axis for COAS alignments. These estimates are based on current knowledge of the star tracker, COAS, IMU, and navigation base error specifications, and were partially verified by preliminary Monte Carlo analysis.

  12. Angle interferometer cross axis errors

    SciTech Connect

    Bryan, J.B.; Carter, D.L.; Thompson, S.L.

    1994-01-01

    Angle interferometers are commonly used to measure surface plate flatness. An error can exist when the centerline of the double comer cube mirror assembly is not square to the surface plate and the guide bar for the mirror sled is curved. Typical errors can be one to two microns per meter. A similar error can exist in the calibration of rotary tables when the centerline of the double comer cube mirror assembly is not square to the axes of rotation of the angle calibrator and the calibrator axis is not parallel to the rotary table axis. Commercial double comer cube assemblies typically have non-parallelism errors of ten milli-radians between their centerlines and their sides and similar values for non-squareness between their centerlines and end surfaces. The authors have developed a simple method for measuring these errors and correcting them by remachining the reference surfaces.

  13. Angle interferometer cross axis errors

    NASA Astrophysics Data System (ADS)

    Bryan, J. B.; Carter, D. L.; Thompson, S. L.

    1994-01-01

    Angle interferometers are commonly used to measure surface plate flatness. An error can exist when the centerline of the double comer cube mirror assembly is not square to the surface plate and the guide bar for the mirror sled is curved. Typical errors can be one to two microns per meter. A similar error can exist in the calibration of rotary tables when the centerline of the double comer cube mirror assembly is not square to the axes of rotation of the angle calibrator and the calibrator axis is not parallel to the rotary table axis. Commercial double comer cube assemblies typically have non-parallelism errors of ten milli-radians between their centerlines and their sides and similar values for non-squareness between their centerlines and end surfaces. The authors have developed a simple method for measuring these errors and correcting them.

  14. A theory of human error

    NASA Technical Reports Server (NTRS)

    Mcruer, D. T.; Clement, W. F.; Allen, R. W.

    1981-01-01

    Human errors tend to be treated in terms of clinical and anecdotal descriptions, from which remedial measures are difficult to derive. Correction of the sources of human error requires an attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A comprehensive analytical theory of the cause-effect relationships governing propagation of human error is indispensable to a reconstruction of the underlying and contributing causes. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation, maritime, automotive, and process control operations is highlighted. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.

  15. Discretization errors in particle tracking

    NASA Astrophysics Data System (ADS)

    Carmon, G.; Mamman, N.; Feingold, M.

    2007-03-01

    High precision video tracking of microscopic particles is limited by systematic and random errors. Systematic errors are partly due to the discretization process both in position and in intensity. We study the behavior of such errors in a simple tracking algorithm designed for the case of symmetric particles. This symmetry algorithm uses interpolation to estimate the value of the intensity at arbitrary points in the image plane. We show that the discretization error is composed of two parts: (1) the error due to the discretization of the intensity, bD and (2) that due to interpolation, bI. While bD behaves asymptotically like N-1 where N is the number of intensity gray levels, bI is small when using cubic spline interpolation.

  16. Sub-nanometer periodic nonlinearity error in absolute distance interferometers.

    PubMed

    Yang, Hongxing; Huang, Kaiqi; Hu, Pengcheng; Zhu, Pengfei; Tan, Jiubin; Fan, Zhigang

    2015-05-01

    Periodic nonlinearity which can result in error in nanometer scale has become a main problem limiting the absolute distance measurement accuracy. In order to eliminate this error, a new integrated interferometer with non-polarizing beam splitter is developed. This leads to disappearing of the frequency and/or polarization mixing. Furthermore, a strict requirement on the laser source polarization is highly reduced. By combining retro-reflector and angel prism, reference and measuring beams can be spatially separated, and therefore, their optical paths are not overlapped. So, the main cause of the periodic nonlinearity error, i.e., the frequency and/or polarization mixing and leakage of beam, is eliminated. Experimental results indicate that the periodic phase error is kept within 0.0018°.

  17. Application of spatially weighted Technology for mapping intermediate and felsic igneous rocks in Fujian Province, China

    NASA Astrophysics Data System (ADS)

    Zhang, Daojun

    2016-04-01

    Magmatic activity is of great significance to mineralization not only for heat and fluid it provides, but also for parts of material source it brings. Due to the cover of soil and vegetation and its spatial nonuniformity detected singals from the ground's surface may be weak and of spatial variability, and this brings serious challenges to mineral exploration in these areas. Two models based on spatially weighted technology, i.e., local singularity analysis (LSA) and spatially weighted logistic regression (SWLR) are applied in this study to deal with this challenge. Coverage cannot block the migration of geochemical elements, it is possible that the geochemical features of soil above concealed rocks can be different from surrounding environment, although this kind of differences are weak; coverage may also weaken the surface expression of geophysical fields. LSA is sensitive to weak changes in density or energy, which makes it effective to map the distribution of concealed igneous rock based on geochemical and geophysical properties. Data integration can produce better classification results than any single data analysis, but spatial variability of spatial variables caused by non-stationary coverage can greatly affect the results since sometimes it is hard to establish a global model. In this paper, SWLR is used to integrate all spatial layers extracted from both geochemical and geophysical data, and the iron polymetallic metallogenic belt in sours-west of Fujian Province is used as s study case. It is found that LSA technique effectively extracts different sources of geologic anomalies; and the spatial distribution of intermediate and felsic igneous rocks delineated by SWLR shows higher accuracy compared with the result obtained via global model.

  18. Research on calibration error of carrier phase against antenna arraying

    NASA Astrophysics Data System (ADS)

    Sun, Ke; Hou, Xiaomin

    2016-11-01

    It is the technical difficulty of uplink antenna arraying that signals from various quarters can not be automatically aligned at the target in deep space. The size of the far-field power combining gain is directly determined by the accuracy of carrier phase calibration. It is necessary to analyze the entire arraying system in order to improve the accuracy of the phase calibration. This paper analyzes the factors affecting the calibration error of carrier phase of uplink antenna arraying system including the error of phase measurement and equipment, the error of the uplink channel phase shift, the position error of ground antenna, calibration receiver and target spacecraft, the error of the atmospheric turbulence disturbance. Discuss the spatial and temporal autocorrelation model of atmospheric disturbances. Each antenna of the uplink antenna arraying is no common reference signal for continuous calibration. So it must be a system of the periodic calibration. Calibration is refered to communication of one or more spacecrafts in a certain period. Because the deep space targets are not automatically aligned to multiplexing received signal. Therefore the aligned signal should be done in advance on the ground. Data is shown that the error can be controlled within the range of demand by the use of existing technology to meet the accuracy of carrier phase calibration. The total error can be controlled within a reasonable range.

  19. Camouflage, Concealment, and Decoys

    DTIC Science & Technology

    2010-11-26

    of smoke, suppressive fires, speed, and natural limited-visibility conditions minimize exposure and avoid enemy fire sacks . However, offensive...MS75047-1 For SG 18-02 w/o gen Mounting kit, smoke gen, M284 1040-01-249-0272 PN31-14-2680 For M157 gen Net, multipurpose, olive -green mesh 8465-00-889

  20. Errors, error detection, error correction and hippocampal-region damage: data and theories.

    PubMed

    MacKay, Donald G; Johnson, Laura W

    2013-11-01

    This review and perspective article outlines 15 observational constraints on theories of errors, error detection, and error correction, and their relation to hippocampal-region (HR) damage. The core observations come from 10 studies with H.M., an amnesic with cerebellar and HR damage but virtually no neocortical damage. Three studies examined the detection of errors planted in visual scenes (e.g., a bird flying in a fish bowl in a school classroom) and sentences (e.g., I helped themselves to the birthday cake). In all three experiments, H.M. detected reliably fewer errors than carefully matched memory-normal controls. Other studies examined the detection and correction of self-produced errors, with controls for comprehension of the instructions, impaired visual acuity, temporal factors, motoric slowing, forgetting, excessive memory load, lack of motivation, and deficits in visual scanning or attention. In these studies, H.M. corrected reliably fewer errors than memory-normal and cerebellar controls, and his uncorrected errors in speech, object naming, and reading aloud exhibited two consistent features: omission and anomaly. For example, in sentence production tasks, H.M. omitted one or more words in uncorrected encoding errors that rendered his sentences anomalous (incoherent, incomplete, or ungrammatical) reliably more often than controls. Besides explaining these core findings, the theoretical principles discussed here explain H.M.'s retrograde amnesia for once familiar episodic and semantic information; his anterograde amnesia for novel information; his deficits in visual cognition, sentence comprehension, sentence production, sentence reading, and object naming; and effects of aging on his ability to read isolated low frequency words aloud. These theoretical principles also explain a wide range of other data on error detection and correction and generate new predictions for future test.

  1. A priori discretization error metrics for distributed hydrologic modeling applications

    NASA Astrophysics Data System (ADS)

    Liu, Hongli; Tolson, Bryan A.; Craig, James R.; Shafii, Mahyar

    2016-12-01

    Watershed spatial discretization is an important step in developing a distributed hydrologic model. A key difficulty in the spatial discretization process is maintaining a balance between the aggregation-induced information loss and the increase in computational burden caused by the inclusion of additional computational units. Objective identification of an appropriate discretization scheme still remains a challenge, in part because of the lack of quantitative measures for assessing discretization quality, particularly prior to simulation. This study proposes a priori discretization error metrics to quantify the information loss of any candidate discretization scheme without having to run and calibrate a hydrologic model. These error metrics are applicable to multi-variable and multi-site discretization evaluation and provide directly interpretable information to the hydrologic modeler about discretization quality. The first metric, a subbasin error metric, quantifies the routing information loss from discretization, and the second, a hydrological response unit (HRU) error metric, improves upon existing a priori metrics by quantifying the information loss due to changes in land cover or soil type property aggregation. The metrics are straightforward to understand and easy to recode. Informed by the error metrics, a two-step discretization decision-making approach is proposed with the advantage of reducing extreme errors and meeting the user-specified discretization error targets. The metrics and decision-making approach are applied to the discretization of the Grand River watershed in Ontario, Canada. Results show that information loss increases as discretization gets coarser. Moreover, results help to explain the modeling difficulties associated with smaller upstream subbasins since the worst discretization errors and highest error variability appear in smaller upstream areas instead of larger downstream drainage areas. Hydrologic modeling experiments under

  2. Mars gravitational field estimation error

    NASA Technical Reports Server (NTRS)

    Compton, H. R.; Daniels, E. F.

    1972-01-01

    The error covariance matrices associated with a weighted least-squares differential correction process have been analyzed for accuracy in determining the gravitational coefficients through degree and order five in the Mars gravitational potential junction. The results are presented in terms of standard deviations for the assumed estimated parameters. The covariance matrices were calculated by assuming Doppler tracking data from a Mars orbiter, a priori statistics for the estimated parameters, and model error uncertainties for tracking-station locations, the Mars ephemeris, the astronomical unit, the Mars gravitational constant (G sub M), and the gravitational coefficients of degrees six and seven. Model errors were treated by using the concept of consider parameters.

  3. Stochastic Models of Human Errors

    NASA Technical Reports Server (NTRS)

    Elshamy, Maged; Elliott, Dawn M. (Technical Monitor)

    2002-01-01

    Humans play an important role in the overall reliability of engineering systems. More often accidents and systems failure are traced to human errors. Therefore, in order to have meaningful system risk analysis, the reliability of the human element must be taken into consideration. Describing the human error process by mathematical models is a key to analyzing contributing factors. Therefore, the objective of this research effort is to establish stochastic models substantiated by sound theoretic foundation to address the occurrence of human errors in the processing of the space shuttle.

  4. Error bounds in cascading regressions

    USGS Publications Warehouse

    Karlinger, M.R.; Troutman, B.M.

    1985-01-01

    Cascading regressions is a technique for predicting a value of a dependent variable when no paired measurements exist to perform a standard regression analysis. Biases in coefficients of a cascaded-regression line as well as error variance of points about the line are functions of the correlation coefficient between dependent and independent variables. Although this correlation cannot be computed because of the lack of paired data, bounds can be placed on errors through the required properties of the correlation coefficient. The potential meansquared error of a cascaded-regression prediction can be large, as illustrated through an example using geomorphologic data. ?? 1985 Plenum Publishing Corporation.

  5. An enhanced MMW and SMMW/THz imaging system performance prediction and analysis tool for concealed weapon detection and pilotage obstacle avoidance

    NASA Astrophysics Data System (ADS)

    Murrill, Steven R.; Jacobs, Eddie L.; Franck, Charmaine C.; Petkie, Douglas T.; De Lucia, Frank C.

    2015-10-01

    The U.S. Army Research Laboratory (ARL) has continued to develop and enhance a millimeter-wave (MMW) and submillimeter- wave (SMMW)/terahertz (THz)-band imaging system performance prediction and analysis tool for both the detection and identification of concealed weaponry, and for pilotage obstacle avoidance. The details of the MATLAB-based model which accounts for the effects of all critical sensor and display components, for the effects of atmospheric attenuation, concealment material attenuation, and active illumination, were reported on at the 2005 SPIE Europe Security and 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). Further development of this tool that includes 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 was reported on at the 2011 SPIE Europe Security and Defence Symposium (Prague). This paper provides a comprehensive review of a newly enhanced MMW and SMMW/THz imaging system analysis and design tool that now includes an improved noise sub-model for more accurate and reliable performance predictions, the capability to account for postcapture image contrast enhancement, and the capability to account for concealment material backscatter with active-illumination- based systems. Present plans for additional expansion of the model's predictive capabilities are also outlined.

  6. Obstacle avoidance and concealed target detection using the Army Research Lab ultra-wideband synchronous impulse reconstruction (UWB SIRE) forward imaging radar

    NASA Astrophysics Data System (ADS)

    Nguyen, Lam; Wong, David; Ressler, Marc; Koenig, Francois; Stanton, Brian; Smith, Gregory; Sichina, Jeffrey; Kappra, Karl

    2007-04-01

    The U.S. Army Research Laboratory (ARL), as part of a mission and customer funded exploratory program, has developed a new low-frequency, ultra-wideband (UWB) synthetic aperture radar (SAR) for forward imaging to support the Army's vision of an autonomous navigation system for robotic ground vehicles. These unmanned vehicles, equipped with an array of imaging sensors, will be tasked to help detect man-made obstacles such as concealed targets, enemy minefields, and booby traps, as well as other natural obstacles such as ditches, and bodies of water. The ability of UWB radar technology to help detect concealed objects has been documented in the past and could provide an important obstacle avoidance capability for autonomous navigation systems, which would improve the speed and maneuverability of these vehicles and consequently increase the survivability of the U. S. forces on the battlefield. One of the primary features of the radar is the ability to collect and process data at combat pace in an affordable, compact, and lightweight package. To achieve this, the radar is based on the synchronous impulse reconstruction (SIRE) technique where several relatively slow and inexpensive analog-to-digital (A/D) converters are used to sample the wide bandwidth of the radar signals. We conducted an experiment this winter at Aberdeen Proving Ground (APG) to support the phenomenological studies of the backscatter from positive and negative obstacles for autonomous robotic vehicle navigation, as well as the detection of concealed targets of interest to the Army. In this paper, we briefly describe the UWB SIRE radar and the test setup in the experiment. We will also describe the signal processing and the forward imaging techniques used in the experiment. Finally, we will present imagery of man-made obstacles such as barriers, concertina wires, and mines.

  7. CAMEO-SIM: a physics-based broadband scene simulation tool for assessment of camouflage, concealment, and deception methodologies

    NASA Astrophysics Data System (ADS)

    Moorhead, Ian R.; Gilmore, Marilyn A.; Houlbrook, Alexander W.; Oxford, David E.; Filbee, David R.; Stroud, Colin A.; Hutchings, G.; Kirk, Albert

    2001-09-01

    Assessment of camouflage, concealment, and deception (CCD) methodologies is not a trivial problem; conventionally the only method has been to carry out field trials, which are both expensive and subject to the vagaries of the weather. In recent years computing power has increased, such that there are now many research programs using synthetic environments for CCD assessments. Such an approach is attractive; the user has complete control over the environmental parameters and many more scenarios can be investigated. The UK Ministry of Defence is currently developing a synthetic scene generation tool for assessing the effectiveness of air vehicle camouflage schemes. The software is sufficiently flexible to allow it to be used in a broader range of applications, including full CCD assessment. The synthetic scene simulation system (CAMEO- SIM) has been developed, as an extensible system, to provide imagery within the 0.4 to 14 micrometers spectral band with as high a physical fidelity as possible. it consists of a scene design tool, an image generator, that incorporates both radiosity and ray-tracing process, and an experimental trials tool. The scene design tool allows the user to develop a 3D representation of the scenario of interest from a fixed viewpoint. Target(s) of interest can be placed anywhere within this 3D representation and may be either static or moving. Different illumination conditions and effects of the atmosphere can be modeled together with directional reflectance effects. The user has complete control over the level of fidelity of the final image. The output from the rendering tool is a sequence of radiance maps, which may be used by sensor models or for experimental trials in which observers carry out target acquisition tasks. The software also maintains an audit trail of all data selected to generate a particular image, both in terms of material properties used and the rendering options chosen. A range of verification tests has shown that the

  8. Multiscale measurement error models for aggregated small area health data.

    PubMed

    Aregay, Mehreteab; Lawson, Andrew B; Faes, Christel; Kirby, Russell S; Carroll, Rachel; Watjou, Kevin

    2016-08-01

    Spatial data are often aggregated from a finer (smaller) to a coarser (larger) geographical level. The process of data aggregation induces a scaling effect which smoothes the variation in the data. To address the scaling problem, multiscale models that link the convolution models at different scale levels via the shared random effect have been proposed. One of the main goals in aggregated health data is to investigate the relationship between predictors and an outcome at different geographical levels. In this paper, we extend multiscale models to examine whether a predictor effect at a finer level hold true at a coarser level. To adjust for predictor uncertainty due to aggregation, we applied measurement error models in the framework of multiscale approach. To assess the benefit of using multiscale measurement error models, we compare the performance of multiscale models with and without measurement error in both real and simulated data. We found that ignoring the measurement error in multiscale models underestimates the regression coefficient, while it overestimates the variance of the spatially structured random effect. On the other hand, accounting for the measurement error in multiscale models provides a better model fit and unbiased parameter estimates.

  9. Elimination of error factors, affecting EM and seismic inversions

    NASA Astrophysics Data System (ADS)

    Magomedov, M.; Zuev, M. A.; Korneev, V. A.; Goloshubin, G.; Zuev, J.; Brovman, Y.

    2013-12-01

    EM or seismic data inversions are affected by many factors, which may conceal the responses from target objects. We address here the contributions from the following effects: 1) Pre-survey spectral sensitivity factor. Preliminary information about a target layer can be used for a pre-survey estimation of the required frequency domain and signal level. A universal approach allows making such estimations in real time, helping the survey crew to optimize an acquisition process. 2) Preliminary velocities' identification and their dispersions for all the seismic waves, arising in a stratified media became a fast working tool, based on the exact analytical solution. 3) Vertical gradients effect. For most layers the log data scatter, requiring an averaging pattern. A linear gradient within each representative layer is a reasonable compromise between required inversion accuracy and forward modeling complexity. 4) An effect from the seismic source's radial component becomes comparable with vertical part for explosive sources. If this effect is not taken into account, a serious modeling error takes place. This problem has an algorithmic solution. 5) Seismic modeling is often based on different representations for a source formulated either for a force or to a potential. The wave amplitudes depend on the formulation, making an inversion result sensitive to it. 6) Asymmetrical seismic waves (modified Rayleigh) in symmetrical geometry around liquid fracture come from S-wave and merge with the modified Krauklis wave at high frequencies. A detail analysis of this feature allows a spectral range optimization for the proper wave's extraction. 7) An ultrasonic experiment was conducted to show different waves appearance for a super-thin water-saturated fracture between two Plexiglas plates, being confirmed by comparison with theoretical computations. 8) A 'sandwich effect' was detected by comparison with averaged layer's effect. This opens an opportunity of the shale gas direct

  10. Aging transition by random errors

    PubMed Central

    Sun, Zhongkui; Ma, Ning; Xu, Wei

    2017-01-01

    In this paper, the effects of random errors on the oscillating behaviors have been studied theoretically and numerically in a prototypical coupled nonlinear oscillator. Two kinds of noises have been employed respectively to represent the measurement errors accompanied with the parameter specifying the distance from a Hopf bifurcation in the Stuart-Landau model. It has been demonstrated that when the random errors are uniform random noise, the change of the noise intensity can effectively increase the robustness of the system. While the random errors are normal random noise, the increasing of variance can also enhance the robustness of the system under certain conditions that the probability of aging transition occurs reaches a certain threshold. The opposite conclusion is obtained when the probability is less than the threshold. These findings provide an alternative candidate to control the critical value of aging transition in coupled oscillator system, which is composed of the active oscillators and inactive oscillators in practice. PMID:28198430

  11. Robust characterization of leakage errors

    NASA Astrophysics Data System (ADS)

    Wallman, Joel J.; Barnhill, Marie; Emerson, Joseph

    2016-04-01

    Leakage errors arise when the quantum state leaks out of some subspace of interest, for example, the two-level subspace of a multi-level system defining a computational ‘qubit’, the logical code space of a quantum error-correcting code, or a decoherence-free subspace. Leakage errors pose a distinct challenge to quantum control relative to the more well-studied decoherence errors and can be a limiting factor to achieving fault-tolerant quantum computation. Here we present a scalable and robust randomized benchmarking protocol for quickly estimating the leakage rate due to an arbitrary Markovian noise process on a larger system. We illustrate the reliability of the protocol through numerical simulations.

  12. Static Detection of Disassembly Errors

    SciTech Connect

    Krishnamoorthy, Nithya; Debray, Saumya; Fligg, Alan K

    2009-10-13

    Static disassembly is a crucial first step in reverse engineering executable files, and there is a consider- able body of work in reverse-engineering of binaries, as well as areas such as semantics-based security anal- ysis, that assumes that the input executable has been correctly disassembled. However, disassembly errors, e.g., arising from binary obfuscations, can render this assumption invalid. This work describes a machine- learning-based approach, using decision trees, for stat- ically identifying possible errors in a static disassem- bly; such potential errors may then be examined more closely, e.g., using dynamic analyses. Experimental re- sults using a variety of input executables indicate that our approach performs well, correctly identifying most disassembly errors with relatively few false positives.

  13. Prospective errors determine motor learning

    PubMed Central

    Takiyama, Ken; Hirashima, Masaya; Nozaki, Daichi

    2015-01-01

    Diverse features of motor learning have been reported by numerous studies, but no single theoretical framework concurrently accounts for these features. Here, we propose a model for motor learning to explain these features in a unified way by extending a motor primitive framework. The model assumes that the recruitment pattern of motor primitives is determined by the predicted movement error of an upcoming movement (prospective error). To validate this idea, we perform a behavioural experiment to examine the model’s novel prediction: after experiencing an environment in which the movement error is more easily predictable, subsequent motor learning should become faster. The experimental results support our prediction, suggesting that the prospective error might be encoded in the motor primitives. Furthermore, we demonstrate that this model has a strong explanatory power to reproduce a wide variety of motor-learning-related phenomena that have been separately explained by different computational models. PMID:25635628

  14. Aging transition by random errors

    NASA Astrophysics Data System (ADS)

    Sun, Zhongkui; Ma, Ning; Xu, Wei

    2017-02-01

    In this paper, the effects of random errors on the oscillating behaviors have been studied theoretically and numerically in a prototypical coupled nonlinear oscillator. Two kinds of noises have been employed respectively to represent the measurement errors accompanied with the parameter specifying the distance from a Hopf bifurcation in the Stuart-Landau model. It has been demonstrated that when the random errors are uniform random noise, the change of the noise intensity can effectively increase the robustness of the system. While the random errors are normal random noise, the increasing of variance can also enhance the robustness of the system under certain conditions that the probability of aging transition occurs reaches a certain threshold. The opposite conclusion is obtained when the probability is less than the threshold. These findings provide an alternative candidate to control the critical value of aging transition in coupled oscillator system, which is composed of the active oscillators and inactive oscillators in practice.

  15. Interpolation Errors in Spectrum Analyzers

    NASA Technical Reports Server (NTRS)

    Martin, J. L.

    1996-01-01

    To obtain the proper measurement amplitude with a spectrum analyzer, the correct frequency-dependent transducer factor must be added to the voltage measured by the transducer. This report examines how entering transducer factors into a spectrum analyzer can cause significant errors in field amplitude due to the misunderstanding of the analyzer's interpolation methods. It also discusses how to reduce these errors to obtain a more accurate field amplitude reading.

  16. Quantum error correction for beginners.

    PubMed

    Devitt, Simon J; Munro, William J; Nemoto, Kae

    2013-07-01

    Quantum error correction (QEC) and fault-tolerant quantum computation represent one of the most vital theoretical aspects of quantum information processing. It was well known from the early developments of this exciting field that the fragility of coherent quantum systems would be a catastrophic obstacle to the development of large-scale quantum computers. The introduction of quantum error correction in 1995 showed that active techniques could be employed to mitigate this fatal problem. However, quantum error correction and fault-tolerant computation is now a much larger field and many new codes, techniques, and methodologies have been developed to implement error correction for large-scale quantum algorithms. In response, we have attempted to summarize the basic aspects of quantum error correction and fault-tolerance, not as a detailed guide, but rather as a basic introduction. The development in this area has been so pronounced that many in the field of quantum information, specifically researchers who are new to quantum information or people focused on the many other important issues in quantum computation, have found it difficult to keep up with the general formalisms and methodologies employed in this area. Rather than introducing these concepts from a rigorous mathematical and computer science framework, we instead examine error correction and fault-tolerance largely through detailed examples, which are more relevant to experimentalists today and in the near future.

  17. Error image aware content restoration

    NASA Astrophysics Data System (ADS)

    Choi, Sungwoo; Lee, Moonsik; Jung, Byunghee

    2015-12-01

    As the resolution of TV significantly increased, content consumers have become increasingly sensitive to the subtlest defect in TV contents. This rising standard in quality demanded by consumers has posed a new challenge in today's context where the tape-based process has transitioned to the file-based process: the transition necessitated digitalizing old archives, a process which inevitably produces errors such as disordered pixel blocks, scattered white noise, or totally missing pixels. Unsurprisingly, detecting and fixing such errors require a substantial amount of time and human labor to meet the standard demanded by today's consumers. In this paper, we introduce a novel, automated error restoration algorithm which can be applied to different types of classic errors by utilizing adjacent images while preserving the undamaged parts of an error image as much as possible. We tested our method to error images detected from our quality check system in KBS(Korean Broadcasting System) video archive. We are also implementing the algorithm as a plugin of well-known NLE(Non-linear editing system), which is a familiar tool for quality control agent.

  18. Dominant modes via model error

    NASA Technical Reports Server (NTRS)

    Yousuff, A.; Breida, M.

    1992-01-01

    Obtaining a reduced model of a stable mechanical system with proportional damping is considered. Such systems can be conveniently represented in modal coordinates. Two popular schemes, the modal cost analysis and the balancing method, offer simple means of identifying dominant modes for retention in the reduced model. The dominance is measured via the modal costs in the case of modal cost analysis and via the singular values of the Gramian-product in the case of balancing. Though these measures do not exactly reflect the more appropriate model error, which is the H2 norm of the output-error between the full and the reduced models, they do lead to simple computations. Normally, the model error is computed after the reduced model is obtained, since it is believed that, in general, the model error cannot be easily computed a priori. The authors point out that the model error can also be calculated a priori, just as easily as the above measures. Hence, the model error itself can be used to determine the dominant modes. Moreover, the simplicity of the computations does not presume any special properties of the system, such as small damping, orthogonal symmetry, etc.

  19. Inherent error in interferometric surface plasmon microscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Bei; Yan, Peng; Gao, Feng; Liu, Yu; Zhang, Qiancheng; Wang, Le

    2016-11-01

    Surface plasmon microscopy (SPRM) usually employs high refractive index prism or high numerical aperture (NA) objective as coupling device to excite surface plasmon. Here we apply high NA oil-immersion objective considering k vector conditions of SPs and localization of SPs which provides better lateral resolution and less cross-talk between adjacent areas. However, performance of an objective based SPRM is often limited by the finite aperture of a physical objective which corresponds to sudden transition and limited bandwidth. Here we give a simplified model of the SPRM and numerically calculate how the sudden transition on the clear aperture edge causes inherent error. Notch filtering algorithm is designed to suppress the noisy ripples. Compared to the pupil function engineering technique, this technique makes both the sacrifice of NA and utilization of spatial light modulator unnecessary and provides a more compact system setup without decreasing the resolution and contrast.

  20. Spatial Statistical Data Fusion (SSDF)

    NASA Technical Reports Server (NTRS)

    Braverman, Amy J.; Nguyen, Hai M.; Cressie, Noel

    2013-01-01

    As remote sensing for scientific purposes has transitioned from an experimental technology to an operational one, the selection of instruments has become more coordinated, so that the scientific community can exploit complementary measurements. However, tech nological and scientific heterogeneity across devices means that the statistical characteristics of the data they collect are different. The challenge addressed here is how to combine heterogeneous remote sensing data sets in a way that yields optimal statistical estimates of the underlying geophysical field, and provides rigorous uncertainty measures for those estimates. Different remote sensing data sets may have different spatial resolutions, different measurement error biases and variances, and other disparate characteristics. A state-of-the-art spatial statistical model was used to relate the true, but not directly observed, geophysical field to noisy, spatial aggregates observed by remote sensing instruments. The spatial covariances of the true field and the covariances of the true field with the observations were modeled. The observations are spatial averages of the true field values, over pixels, with different measurement noise superimposed. A kriging framework is used to infer optimal (minimum mean squared error and unbiased) estimates of the true field at point locations from pixel-level, noisy observations. A key feature of the spatial statistical model is the spatial mixed effects model that underlies it. The approach models the spatial covariance function of the underlying field using linear combinations of basis functions of fixed size. Approaches based on kriging require the inversion of very large spatial covariance matrices, and this is usually done by making simplifying assumptions about spatial covariance structure that simply do not hold for geophysical variables. In contrast, this method does not require these assumptions, and is also computationally much faster. This method is

  1. Importance of Ionospheric Gradients for error Correction

    NASA Astrophysics Data System (ADS)

    Ravula, Ramprasad

    Importance of Ionospheric Gradients for error Correction R. Ram Prasad1, P.Nagasekhar2 1Sai Spurthi Institute of Technology-JNTU Hyderabad,2Sai Spurthi Institute of Technology-JNTU Hyderabad Email ID:rams.ravula@gmail.com In India, Indian Space Research Organization (ISRO) has established with an objective to develop space technology and its application to various national tasks. To cater to the needs of civil aviation applications, GPS Aided Geo Augmented Navigation (GAGAN) system is being jointly implemented along with Airports Authority of India (AAI) over the Indian region. The most predominant parameter affecting the navigation accuracy of GAGAN is ionospheric delay which is a function of total number of electrons present in one square meter cylindrical cross sectional area in the line of site direction between the satellite and the user on the earth i.e. Total Electron Content (TEC).The irregular distribution of electron densities i.e. rate of TEC variation, causes Ionospheric gradients such as spatial gradients (Expressed in TECu/km) and temporal gradients (Expressed in TECu /minute). Among the satellite signals arriving to the earth in multiple directions, the signals which suffer from severe ionospheric gradients can be estimated i.e. Rate of TEC Index (ROTI) and Rate of TEC (ROT). These aspects which contribute to errors can be treated for improving GAGAN positional accuracy.

  2. Sexual Venue Selection and Strategies for Concealment of Same-Sex Behavior Among Non-Disclosing Men Who Have Sex with Men and Women

    PubMed Central

    Schrimshaw, Eric W.; Downing, Martin J.; Siegel, Karolynn

    2011-01-01

    In order to conceal their same-sex behavior, men who have sex with men and women (MSMW) who do not disclose their same-sex behavior to female partners must be cautious in their attempts to find potential male partners. This study interviewed 46 non-gay identified, non-disclosing MSMW to identify the venues where they meet male sexual partners and the strategies they use to reduce the likelihood of discovery when at such venues. Most (74%) reported meeting a male partner in a sexual venue (e.g., bar/club, park) in the past year. Strategies to reduce the risk of discovery while seeking male partners included: 1) avoiding certain venues; 2) attending venues away from home; 3) meeting partners on the Internet, 4) preferring venues that have potential non-sexual uses, 5) having sex at the partner’s place, and 6) limiting their on-site sexual activities. These findings provide insight into the coping strategies these men use to manage the conflicting needs to conceal their behavior and meet sexual partners. PMID:23241205

  3. Error-associated behaviors and error rates for robotic geology

    NASA Technical Reports Server (NTRS)

    Anderson, Robert C.; Thomas, Geb; Wagner, Jacob; Glasgow, Justin

    2004-01-01

    This study explores human error as a function of the decision-making process. One of many models for human decision-making is Rasmussen's decision ladder [9]. The decision ladder identifies the multiple tasks and states of knowledge involved in decision-making. The tasks and states of knowledge can be classified by the level of cognitive effort required to make the decision, leading to the skill, rule, and knowledge taxonomy (Rasmussen, 1987). Skill based decisions require the least cognitive effort and knowledge based decisions require the greatest cognitive effort. Errors can occur at any of the cognitive levels.

  4. Correction of magnetooptic device phase errors in optical correlators through filter design modifications

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    We address the problem of optical phase errors in an optical correlator introduced by the input and filter plane spatial light modulators. Specifically, we study a laboratory correlator with magnetooptic spatial light modulator (MOSLM) devices. We measure and characterize the phase errors, analyze their effects on the correlation process, and discuss a means of correction through a design modification of the binary phase-only optical filter function. The phase correction technique is found to produce correlation results close to those of an error-free correlator.

  5. Error Analyses of the North Alabama Lightning Mapping Array (LMA)

    NASA Technical Reports Server (NTRS)

    Koshak, W. J.; Solokiewicz, R. J.; Blakeslee, R. J.; Goodman, S. J.; Christian, H. J.; Hall, J. M.; Bailey, J. C.; Krider, E. P.; Bateman, M. G.; Boccippio, D. J.

    2003-01-01

    Two approaches are used to characterize how accurately the North Alabama Lightning Mapping Array (LMA) is able to locate lightning VHF sources in space and in time. The first method uses a Monte Carlo computer simulation to estimate source retrieval errors. The simulation applies a VHF source retrieval algorithm that was recently developed at the NASA-MSFC and that is similar, but not identical to, the standard New Mexico Tech retrieval algorithm. The second method uses a purely theoretical technique (i.e., chi-squared Curvature Matrix theory) to estimate retrieval errors. Both methods assume that the LMA system has an overall rms timing error of 50ns, but all other possible errors (e.g., multiple sources per retrieval attempt) are neglected. The detailed spatial distributions of retrieval errors are provided. Given that the two methods are completely independent of one another, it is shown that they provide remarkably similar results, except that the chi-squared theory produces larger altitude error estimates than the (more realistic) Monte Carlo simulation.

  6. Error Evaluation of Planetary Atmospheric Motion Vectors by Statistical Presumption Technique.

    NASA Astrophysics Data System (ADS)

    MURACHI, T.; IMAMURA, T.; HIGUCHI, T.; NAKAMURA, M.

    2002-05-01

    In the Solar System there are the planets (e.g. Venus etc.) whose surface environment and general atmospheric circulation differs from Earth_fs one. If we can understand the meteorology of these planets, we get the information of meteorological mechanism which completely differs from the Earth_f one. By returning this information to the Earth's meteorology we more deeply understand the meteorological phenomenon of the Earth than now. Therefore, it is important to research the meteorology of these planets. In past meteorological researches of the atmospheric planets they had not reached to detailed understanding. This reason is that in many cases target physical phenomenon is covered with the error because of data shortage. For solving this problem we must obtain the many data. However, examining the past research, I notice that the possibility of overestimate of error. Concretely, it is like below. In past meteorological researches of the atmospheric planets except the Earth, in which the Atmospheric Motion Vectors (AMVs) are derived from their cloud images, the AMVs' accuracy is evaluated from the spatial and time adjustment. The AMVs which depart the permissible range are deleted, which is decided in view of the spatial and time scale of the target physical phenomenon and the possibility of miss-matching. The error of AMVs is defined as the standard deviation of neighboring AMVs. In this definition, however, the error of AMVs depends on the permissible range and is anticipated to be as large as the target physical phenomenon. In fact, there were some researches that they couldn't prove whether the target physical phenomenon existed because of the large error of itself. The proper error evaluation as well as the observation method is important for proving the existence of the target physical phenomenon. The purpose of this study is to establish the error evaluation of AMVs, which reflects influence of the image spatial resolution and the change of cloud shape upon

  7. Spatial Inferences in Narrative Comprehension: the Role of Verbal and Spatial Working Memory.

    PubMed

    Irrazabal, Natalia; Burin, Debora

    2016-03-14

    During the comprehension of narrative texts, readers keep a mental representation of the location of protagonists and objects; a breach in spatial coherence is detected by longer online reading times (consistency effect). We addressed whether these spatial inferences involve verbal or spatial working memory in two experiments, combining the consistency paradigm with selective verbal and spatial working memory concurrent tasks. The first experiment found longer reading times with a concurrent spatial task under imagery instructions (t33 = 2.87, p = .021). The second experiment, under comprehension reading instructions, found effects of verbal interference on reading times and accuracy. With a verbal secondary task, reading times for the target sentence were shorter (t45 = 3.60, p = .004) and the error rate was significantly higher (t47 = 2.95, p = .005) than without interference. This pattern of results suggests that spatial inferences in narrative comprehension rely mainly on verbal resources, and spatial working memory resources are recruited when imagery is required.

  8. POSITION ERROR IN STATION-KEEPING SATELLITE

    DTIC Science & Technology

    of an error in satellite orientation and the sun being in a plane other than the equatorial plane may result in errors in position determination. The nature of the errors involved is described and their magnitudes estimated.

  9. Orbit IMU alignment: Error analysis

    NASA Technical Reports Server (NTRS)

    Corson, R. W.

    1980-01-01

    A comprehensive accuracy analysis of orbit inertial measurement unit (IMU) alignments using the shuttle star trackers was completed and the results are presented. Monte Carlo techniques were used in a computer simulation of the IMU alignment hardware and software systems to: (1) determine the expected Space Transportation System 1 Flight (STS-1) manual mode IMU alignment accuracy; (2) investigate the accuracy of alignments in later shuttle flights when the automatic mode of star acquisition may be used; and (3) verify that an analytical model previously used for estimating the alignment error is a valid model. The analysis results do not differ significantly from expectations. The standard deviation in the IMU alignment error for STS-1 alignments was determined to the 68 arc seconds per axis. This corresponds to a 99.7% probability that the magnitude of the total alignment error is less than 258 arc seconds.

  10. Error analysis using organizational simulation.

    PubMed Central

    Fridsma, D. B.

    2000-01-01

    Organizational simulations have been used by project organizations in civil and aerospace industries to identify work processes and organizational structures that are likely to fail under certain conditions. Using a simulation system based on Galbraith's information-processing theory and Simon's notion of bounded-rationality, we retrospectively modeled a chemotherapy administration error that occurred in a hospital setting. Our simulation suggested that when there is a high rate of unexpected events, the oncology fellow was differentially backlogged with work when compared with other organizational members. Alternative scenarios suggested that providing more knowledge resources to the oncology fellow improved her performance more effectively than adding additional staff to the organization. Although it is not possible to know whether this might have prevented the error, organizational simulation may be an effective tool to prospectively evaluate organizational "weak links", and explore alternative scenarios to correct potential organizational problems before they generate errors. PMID:11079885

  11. Sensation seeking and error processing.

    PubMed

    Zheng, Ya; Sheng, Wenbin; Xu, Jing; Zhang, Yuanyuan

    2014-09-01

    Sensation seeking is defined by a strong need for varied, novel, complex, and intense stimulation, and a willingness to take risks for such experience. Several theories propose that the insensitivity to negative consequences incurred by risks is one of the hallmarks of sensation-seeking behaviors. In this study, we investigated the time course of error processing in sensation seeking by recording event-related potentials (ERPs) while high and low sensation seekers performed an Eriksen flanker task. Whereas there were no group differences in ERPs to correct trials, sensation seeking was associated with a blunted error-related negativity (ERN), which was female-specific. Further, different subdimensions of sensation seeking were related to ERN amplitude differently. These findings indicate that the relationship between sensation seeking and error processing is sex-specific.

  12. Error Field Correction in ITER

    SciTech Connect

    Park, Jong-kyu; Boozer, Allen H.; Menard, Jonathan E.; Schaffer, Michael J.

    2008-05-22

    A new method for correcting magnetic field errors in the ITER tokamak is developed using the Ideal Perturbed Equilibrium Code (IPEC). The dominant external magnetic field for driving islands is shown to be localized to the outboard midplane for three ITER equilibria that represent the projected range of operational scenarios. The coupling matrices between the poloidal harmonics of the external magnetic perturbations and the resonant fields on the rational surfaces that drive islands are combined for different equilibria and used to determine an ordered list of the dominant errors in the external magnetic field. It is found that efficient and robust error field correction is possible with a fixed setting of the correction currents relative to the currents in the main coils across the range of ITER operating scenarios that was considered.

  13. Constraint checking during error recovery

    NASA Technical Reports Server (NTRS)

    Lutz, Robyn R.; Wong, Johnny S. K.

    1993-01-01

    The system-level software onboard a spacecraft is responsible for recovery from communication, power, thermal, and computer-health anomalies that may occur. The recovery must occur without disrupting any critical scientific or engineering activity that is executing at the time of the error. Thus, the error-recovery software may have to execute concurrently with the ongoing acquisition of scientific data or with spacecraft maneuvers. This work provides a technique by which the rules that constrain the concurrent execution of these processes can be modeled in a graph. An algorithm is described that uses this model to validate that the constraints hold for all concurrent executions of the error-recovery software with the software that controls the science and engineering activities of the spacecraft. The results are applicable to a variety of control systems with critical constraints on the timing and ordering of the events they control.

  14. Characteristics of tasks utilized for evaluation of judgment errors in the elderly

    PubMed Central

    Sakamoto, Yumi; Ohashi, Yukari

    2016-01-01

    [Purpose] The present study compared assessments utilized to evaluate judgment errors in the elderly. [Subjects and Methods] A total of 94 community-dwelling elderly participants in an examination of physical fitness for health promotion and health guidance in a rural area in Japan were included. Spatially and temporally predictive tasks were used to evaluate judgment errors. Distances measured on the Functional Reach and upward reaching tests were used to assess spatial prediction, and times measured on the Timed Up and Go test and Standardized Walking Obstacle Course were used to assess temporal prediction. Differences between the self-predicted values and actual results were deemed judgment errors. [Results] Significant differences were observed between self-predicted abilities and the patients’ performances. Participants underestimated their abilities in spatially predictive tasks and overestimated them in temporally predictive tasks. On comparing the four tasks, there were significant differences in judgment error ratios between them. Statistical analysis indicated a significant difference in the judgment error ratio for the Standardized Walking Obstacle Course correlated with a history of falls. [Conclusion] Judgment errors were identified using both spatially and temporally predictive tasks. A temporally predictive task like the Standardized Walking Obstacle Course might better evaluate judgment errors in the elderly. PMID:27821954

  15. A research agenda: does geocoding positional error matter in health GIS studies?

    PubMed

    Jacquez, Geoffrey M

    2012-04-01

    Until recently, little attention has been paid to geocoding positional accuracy and its impacts on accessibility measures; estimates of disease rates; findings of disease clustering; spatial prediction and modeling of health outcomes; and estimates of individual exposures based on geographic proximity to pollutant and pathogen sources. It is now clear that positional errors can result in flawed findings and poor public health decisions. Yet the current state-of-practice is to ignore geocoding positional uncertainty, primarily because of a lack of theory, methods and tools for quantifying, modeling, and adjusting for geocoding positional errors in health analysis. This paper proposes a research agenda to address this need. It summarizes the basics of the geocoding process, its assumptions, and empirical evidence describing the magnitude of geocoding positional error. An overview of the impacts of positional error in health analysis, including accessibility, disease clustering, exposure reconstruction, and spatial weights estimation is presented. The proposed research agenda addresses five key needs: (1) a lack of standardized, open-access geocoding resources for use in health research; (2) a lack of geocoding validation datasets that will allow the evaluation of alternative geocoding engines and procedures; (3) a lack of spatially explicit geocoding positional error models; (4) a lack of resources for assessing the sensitivity of spatial analysis results to geocoding positional error; (5) a lack of demonstration studies that illustrate the sensitivity of health policy decisions to geocoding positional error.

  16. Main error factors, affecting inversion of EM data

    NASA Astrophysics Data System (ADS)

    Zuev, M. A.; Magomedov, M.; Korneev, V. A.; Goloshubin, G.; Zuev, J.; Brovman, Y.

    2013-12-01

    Inversions of EM data are complicated by a number of factors that need to be taken into account. These factors might contribute by tens of percents in data values, concealing responses from target objects, which usually contribute at the level of few percents only. We developed the exact analytical solutions of the EM wave equations that properly incorporate the contributions of the following effects: 1) A finite source size effect, where conventional dipole (zero-size) approximation brings 10-40% error compare to a real size source, needed to provide adequate signal-to-noise ratio. 2) Complex topography. A three-parametrical approach allows to keep the data misfits in 0.5% corridor while topography effect might be up to 40%. 3) Grounding shadow effect, caused by return ground currents, when Tx-line vicinity is horizontally non-uniform. By keeping survey setup within some reasonable geometrical ratios, the shadow effect comes to just one frequency-independent coefficient, which can be excluded from processing by using logarithmical derivatives. 4) Layer's wide spectral range effect. This brings to multi-layer spectral overlapping, so each frequency is affected by many layers; that requires wide spectral range processing, making the typical 'few-frequency data acquisition' non-reliable. 5) Horizontal sensitivity effect. The typical view at the target signal, reflected from a Tx-Rx mid-point is valid only for a ray approximation, reliable in a far-field zone. Unlike this, the real EM surveys usually work in near-field zone. Thus Tx-Rx mid-point does not represent the layer, so a sensitivity distribution function must be computed for each layer for the following 3D-unification process. 6) Wide range Rx-directions from mid-line Tx. Survey terrain often prevents placing Rx perpendicular to Tx-line, and even small deviations without proper corrections cause a significant inaccuracy. A radical simplification of the effect's description becomes possible after applying a

  17. Probing model-independent cosmic opacity and its spatial properties

    NASA Astrophysics Data System (ADS)

    Chen, Jun

    2016-11-01

    Cosmic opacity and its spatial distribution have been constrained with a model independent method. The average opacity of the universe is not zero, but can be zero in the 1σ error range. The best-fit value of the spatial distribution of cosmic opacity is not a constant as the redshift varies, though a homogeneous and transparent universe is favored in the 2σ error range.

  18. Medication errors: definitions and classification.

    PubMed

    Aronson, Jeffrey K

    2009-06-01

    1. To understand medication errors and to identify preventive strategies, we need to classify them and define the terms that describe them. 2. The four main approaches to defining technical terms consider etymology, usage, previous definitions, and the Ramsey-Lewis method (based on an understanding of theory and practice). 3. A medication error is 'a failure in the treatment process that leads to, or has the potential to lead to, harm to the patient'. 4. Prescribing faults, a subset of medication errors, should be distinguished from prescription errors. A prescribing fault is 'a failure in the prescribing [decision-making] process that leads to, or has the potential to lead to, harm to the patient'. The converse of this, 'balanced prescribing' is 'the use of a medicine that is appropriate to the patient's condition and, within the limits created by the uncertainty that attends therapeutic decisions, in a dosage regimen that optimizes the balance of benefit to harm'. This excludes all forms of prescribing faults, such as irrational, inappropriate, and ineffective prescribing, underprescribing and overprescribing. 5. A prescription error is 'a failure in the prescription writing process that results in a wrong instruction about one or more of the normal features of a prescription'. The 'normal features' include the identity of the recipient, the identity of the drug, the formulation, dose, route, timing, frequency, and duration of administration. 6. Medication errors can be classified, invoking psychological theory, as knowledge-based mistakes, rule-based mistakes, action-based slips, and memory-based lapses. This classification informs preventive strategies.

  19. Automatic-repeat-request error control schemes

    NASA Technical Reports Server (NTRS)

    Lin, S.; Costello, D. J., Jr.; Miller, M. J.

    1983-01-01

    Error detection incorporated with automatic-repeat-request (ARQ) is widely used for error control in data communication systems. This method of error control is simple and provides high system reliability. If a properly chosen code is used for error detection, virtually error-free data transmission can be attained. Various types of ARQ and hybrid ARQ schemes, and error detection using linear block codes are surveyed.

  20. Spatial Dynamics and Determinants of County-Level Education Expenditure in China

    ERIC Educational Resources Information Center

    Gu, Jiafeng

    2012-01-01

    In this paper, a multivariate spatial autoregressive model of local public education expenditure determination with autoregressive disturbance is developed and estimated. The existence of spatial interdependence is tested using Moran's I statistic and Lagrange multiplier test statistics for both the spatial error and spatial lag models. The full…