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Sample records for adaptation improves temporal

  1. Integrity of medial temporal structures may predict better improvement of spatial neglect with prism adaptation treatment.

    Science.gov (United States)

    Chen, Peii; Goedert, Kelly M; Shah, Priyanka; Foundas, Anne L; Barrett, A M

    2014-09-01

    Prism adaptation treatment (PAT) is a promising rehabilitative method for functional recovery in persons with spatial neglect. Previous research suggests that PAT improves motor-intentional "aiming" deficits that frequently occur with frontal lesions. To test whether presence of frontal lesions predicted better improvement of spatial neglect after PAT, the current study evaluated neglect-specific improvement in functional activities (assessment with the Catherine Bergego Scale) over time in 21 right-brain-damaged stroke survivors with left-sided spatial neglect. The results demonstrated that neglect patients' functional activities improved after two weeks of PAT and continued improving for four weeks. Such functional improvement did not occur equally in all of the participants: Neglect patients with lesions involving the frontal cortex (n = 13) experienced significantly better functional improvement than did those without frontal lesions (n = 8). More importantly, voxel-based lesion-behavior mapping (VLBM) revealed that in comparison to the group of patients without frontal lesions, the frontal-lesioned neglect patients had intact regions in the medial temporal areas, the superior temporal areas, and the inferior longitudinal fasciculus. The medial cortical and subcortical areas in the temporal lobe were especially distinguished in the "frontal lesion" group. The findings suggest that the integrity of medial temporal structures may play an important role in supporting functional improvement after PAT.

  2. Temporal and structural heterogeneities emerging in adaptive temporal networks

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    Aoki, Takaaki; Rocha, Luis E. C.; Gross, Thilo

    2016-04-01

    We introduce a model of adaptive temporal networks whose evolution is regulated by an interplay between node activity and dynamic exchange of information through links. We study the model by using a master equation approach. Starting from a homogeneous initial configuration, we show that temporal and structural heterogeneities, characteristic of real-world networks, spontaneously emerge. This theoretically tractable model thus contributes to the understanding of the dynamics of human activity and interaction networks.

  3. Temporal and structural heterogeneities emerging in adaptive temporal networks

    CERN Document Server

    Aoki, Takaaki; Gross, Thilo

    2015-01-01

    We introduce a model of adaptive temporal networks whose evolution is regulated by an interplay between node activity and dynamic exchange of information through links. We study the model by using a master equation approach. Starting from a homogeneous initial configuration, we show that temporal and structural heterogeneities, characteristic of real-world networks, spontaneously emerge. This theoretically tractable model thus contributes to the understanding of the dynamics of human activity and interaction networks.

  4. Improved Adaptive Fingerprint Binarization

    OpenAIRE

    Bartunek, Josef Ström; Nilsson, Mikael; Nordberg, Jörgen; Claesson, Ingvar

    2008-01-01

    In this paper improvements to a previous work are presented. Removing the redundant artifacts in the fingerprint mask is introduced enhancing the final result. The proposed method is entirely adaptive process adjusting to each fingerprint without any further supervision of the user. Hence, the algorithm is insensitive to the characteristics of the fingerprint sensor and the various physical appearances of the fingerprints. Further, a detailed description of fingerprint mask generation not ful...

  5. Adaptation to speed in macaque middle temporal and medial superior temporal areas.

    Science.gov (United States)

    Price, Nicholas S C; Born, Richard T

    2013-03-01

    The response of a sensory neuron to an unchanging stimulus typically adapts, showing decreases in response gain that are accompanied by changes in the shape of tuning curves. It remains unclear whether these changes arise purely due to spike rate adaptation within single neurons or whether they are dependent on network interactions between neurons. Further, it is unclear how the timescales of neural and perceptual adaptation are related. To examine this issue, we compared speed tuning of middle temporal (MT) and medial superior temporal neurons in macaque visual cortex after adaptation to two different reference speeds. For 75% of speed-tuned units, adaptation caused significant changes in tuning that could be explained equally well as lateral shifts, vertical gain changes, or both. These tuning changes occurred rapidly, as both neuronal firing rate and Fano factor showed no evidence of changing beyond the first 500 ms after motion onset, and the magnitude of tuning curve changes showed no difference between trials with adaptation durations shorter or longer than 1 s. Importantly, the magnitude of tuning shifts was correlated with the transient-sustained index, which measures a well characterized form of rapid response adaptation in MT, and is likely associated with changes at the level of neuronal networks. Tuning curves changed in a manner that increased neuronal sensitivity around the adapting speed, consistent with improvements in human and macaque psychophysical performance that we observed over the first several hundred ms of adaptation. PMID:23467352

  6. Motor activity improves temporal expectancy.

    Directory of Open Access Journals (Sweden)

    Lilian Fautrelle

    Full Text Available Certain brain areas involved in interval timing are also important in motor activity. This raises the possibility that motor activity might influence interval timing. To test this hypothesis, we assessed interval timing in healthy adults following different types of training. The pre- and post-training tasks consisted of a button press in response to the presentation of a rhythmic visual stimulus. Alterations in temporal expectancy were evaluated by measuring response times. Training consisted of responding to the visual presentation of regularly appearing stimuli by either: (1 pointing with a whole-body movement, (2 pointing only with the arm, (3 imagining pointing with a whole-body movement, (4 simply watching the stimulus presentation, (5 pointing with a whole-body movement in response to a target that appeared at irregular intervals (6 reading a newspaper. Participants performing a motor activity in response to the regular target showed significant improvements in judgment times compared to individuals with no associated motor activity. Individuals who only imagined pointing with a whole-body movement also showed significant improvements. No improvements were observed in the group that trained with a motor response to an irregular stimulus, hence eliminating the explanation that the improved temporal expectations of the other motor training groups was purely due to an improved motor capacity to press the response button. All groups performed a secondary task equally well, hence indicating that our results could not simply be attributed to differences in attention between the groups. Our results show that motor activity, even when it does not play a causal or corrective role, can lead to improved interval timing judgments.

  7. Motor activity improves temporal expectancy.

    Science.gov (United States)

    Fautrelle, Lilian; Mareschal, Denis; French, Robert; Addyman, Caspar; Thomas, Elizabeth

    2015-01-01

    Certain brain areas involved in interval timing are also important in motor activity. This raises the possibility that motor activity might influence interval timing. To test this hypothesis, we assessed interval timing in healthy adults following different types of training. The pre- and post-training tasks consisted of a button press in response to the presentation of a rhythmic visual stimulus. Alterations in temporal expectancy were evaluated by measuring response times. Training consisted of responding to the visual presentation of regularly appearing stimuli by either: (1) pointing with a whole-body movement, (2) pointing only with the arm, (3) imagining pointing with a whole-body movement, (4) simply watching the stimulus presentation, (5) pointing with a whole-body movement in response to a target that appeared at irregular intervals (6) reading a newspaper. Participants performing a motor activity in response to the regular target showed significant improvements in judgment times compared to individuals with no associated motor activity. Individuals who only imagined pointing with a whole-body movement also showed significant improvements. No improvements were observed in the group that trained with a motor response to an irregular stimulus, hence eliminating the explanation that the improved temporal expectations of the other motor training groups was purely due to an improved motor capacity to press the response button. All groups performed a secondary task equally well, hence indicating that our results could not simply be attributed to differences in attention between the groups. Our results show that motor activity, even when it does not play a causal or corrective role, can lead to improved interval timing judgments. PMID:25806813

  8. Temporal percolation of a susceptible adaptive network

    CERN Document Server

    Valdez, L D; Braunstein, L A

    2013-01-01

    In the last decades, due to the appearance of many diseases such as SARS and the H1N1 flu strain, many authors studied the impact of the disease spreading in the evolution of the infected individuals using the susceptible-infected-recovered model. However, few authors focused on the temporal behavior of the susceptible individuals. Recently it was found that in an epidemic spreading, the dynamic of the size of the biggest susceptible cluster can be explained by a temporal node void percolation [Valdez et al PLoS ONE 7, e44188 (2012)]. It was shown that the size of the biggest susceptible cluster is the order parameter of this temporal percolation where the control parameter can be related to the number of links between susceptible individuals at a given time. As a consequence, there is a critical time at which the biggest susceptible cluster is destroyed. In this paper, we study the susceptible-infected-recovered model in an adaptive network where an intermittent social distancing strategy is applied. In this...

  9. Simultaneous Spectral Temporal Adaptive Raman Spectrometer - SSTARS

    Science.gov (United States)

    Blacksberg, Jordana

    2010-01-01

    Raman spectroscopy is a prime candidate for the next generation of planetary instruments, as it addresses the primary goal of mineralogical analysis, which is structure and composition. However, large fluorescence return from many mineral samples under visible light excitation can render Raman spectra unattainable. Using the described approach, Raman and fluorescence, which occur on different time scales, can be simultaneously obtained from mineral samples using a compact instrument in a planetary environment. This new approach is taken based on the use of time-resolved spectroscopy for removing the fluorescence background from Raman spectra in the laboratory. In the SSTARS instrument, a visible excitation source (a green, pulsed laser) is used to generate Raman and fluorescence signals in a mineral sample. A spectral notch filter eliminates the directly reflected beam. A grating then disperses the signal spectrally, and a streak camera provides temporal resolution. The output of the streak camera is imaged on the CCD (charge-coupled device), and the data are read out electronically. By adjusting the sweep speed of the streak camera, anywhere from picoseconds to milliseconds, it is possible to resolve Raman spectra from numerous fluorescence spectra in the same sample. The key features of SSTARS include a compact streak tube capable of picosecond time resolution for collection of simultaneous spectral and temporal information, adaptive streak tube electronics that can rapidly change from one sweep rate to another over ranges of picoseconds to milliseconds, enabling collection of both Raman and fluorescence signatures versus time and wavelength, and Synchroscan integration that allows for a compact, low-power laser without compromising ultimate sensitivity.

  10. Improving the algorithm of temporal relation propagation

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    Shen, Jifeng; Xu, Dan; Liu, Tongming

    2005-03-01

    In the military Multi Agent System, every agent needs to analyze the temporal relationships among the tasks or combat behaviors, and it"s very important to reflect the battlefield situation in time. The temporal relation among agents is usually very complex, and we model it with interval algebra (IA) network. Therefore an efficient temporal reasoning algorithm is vital in battle MAS model. The core of temporal reasoning is path consistency algorithm, an efficient path consistency algorithm is necessary. In this paper we used the Interval Matrix Calculus (IMC) method to represent the temporal relation, and optimized the path consistency algorithm by improving the efficiency of propagation of temporal relation based on the Allen's path consistency algorithm.

  11. Temporal recalibration in vocalization induced by adaptation of delayed auditory feedback.

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    Kosuke Yamamoto

    Full Text Available BACKGROUND: We ordinarily perceive our voice sound as occurring simultaneously with vocal production, but the sense of simultaneity in vocalization can be easily interrupted by delayed auditory feedback (DAF. DAF causes normal people to have difficulty speaking fluently but helps people with stuttering to improve speech fluency. However, the underlying temporal mechanism for integrating the motor production of voice and the auditory perception of vocal sound remains unclear. In this study, we investigated the temporal tuning mechanism integrating vocal sensory and voice sounds under DAF with an adaptation technique. METHODS AND FINDINGS: Participants produced a single voice sound repeatedly with specific delay times of DAF (0, 66, 133 ms during three minutes to induce 'Lag Adaptation'. They then judged the simultaneity between motor sensation and vocal sound given feedback. We found that lag adaptation induced a shift in simultaneity responses toward the adapted auditory delays. This indicates that the temporal tuning mechanism in vocalization can be temporally recalibrated after prolonged exposure to delayed vocal sounds. Furthermore, we found that the temporal recalibration in vocalization can be affected by averaging delay times in the adaptation phase. CONCLUSIONS: These findings suggest vocalization is finely tuned by the temporal recalibration mechanism, which acutely monitors the integration of temporal delays between motor sensation and vocal sound.

  12. Temporal adaptation enhances efficient contrast gain control on natural images.

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    Fabian Sinz

    Full Text Available Divisive normalization in primary visual cortex has been linked to adaptation to natural image statistics in accordance to Barlow's redundancy reduction hypothesis. Using recent advances in natural image modeling, we show that the previously studied static model of divisive normalization is rather inefficient in reducing local contrast correlations, but that a simple temporal contrast adaptation mechanism of the half-saturation constant can substantially increase its efficiency. Our findings reveal the experimentally observed temporal dynamics of divisive normalization to be critical for redundancy reduction.

  13. Improving temporal cognition by enhancing motivation.

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    Avlar, Billur; Kahn, Julia B; Jensen, Greg; Kandel, Eric R; Simpson, Eleanor H; Balsam, Peter D

    2015-10-01

    Increasing motivation can positively impact cognitive performance. Here we employed a cognitive timing task that allows us to detect changes in cognitive performance that are not influenced by general activity or arousal factors such as the speed or persistence of responding. This approach allowed us to manipulate motivation using three different methods; molecular/genetic, behavioral and pharmacological. Increased striatal D2Rs resulted in deficits in temporal discrimination. Switching off the transgene improved motivation in earlier studies, and here partially rescued the temporal discrimination deficit. To manipulate motivation behaviorally, we altered reward magnitude and found that increasing reward magnitude improved timing in control mice and partially rescued timing in the transgenic mice. Lastly, we manipulated motivation pharmacologically using a functionally selective 5-HT2C receptor ligand, SB242084, which we previously found to increase incentive motivation. SB242084 improved temporal discrimination in both control and transgenic mice. Thus, while there is a general intuitive belief that motivation can affect cognition, we here provide a direct demonstration that enhancing motivation, in a variety of ways, can be an effective strategy for enhancing temporal cognition. Understanding the interaction of motivation and cognition is of clinical significance since many psychiatric disorders are characterized by deficits in both domains.

  14. A comparison between temporal and subband minimum variance adaptive beamforming

    DEFF Research Database (Denmark)

    Diamantis, Konstantinos; Voxen, Iben Holfort; Greenaway, Alan H.;

    2014-01-01

    and subband approaches. From a cyst phantom and for 128 emissions, the contrast level is calculated at -54 dB and -63 dB respectively at the same depth, with the initial shape of the cyst being preserved in contrast to conventional beamforming. The difference between the two adaptive beamformers is......This paper compares the performance between temporal and subband Minimum Variance (MV) beamformers for medical ultrasound imaging. Both adaptive methods provide an optimized set of apodization weights but are implemented in the time and frequency domains respectively. Their performance is evaluated...... with simulated synthetic aperture data obtained from Field II and is quantified by the Full-Width-Half-Maximum (FWHM), the Peak-Side-Lobe level (PSL) and the contrast level. From a point phantom, a full sequence of 128 emissions with one transducer element transmitting and all 128 elements receiving...

  15. Improving arterial spin labeling data by temporal filtering

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    Petr, Jan; Ferre, Jean-Christophe; Gauvrit, Jean-Yves; Barillot, Christian

    2010-03-01

    Arterial spin labeling (ASL) is an MRI method for imaging brain perfusion by magnetically labeling blood in brain feeding arteries. The perfusion is obtained from the difference between images with and without prior labeling. Image noise is one of the main problems of ASL as the difference is around 0.5-2% of the image magnitude. Usually, 20-40 pairs of images need to be acquired and averaged to reach a satisfactory quality. The images are acquired shortly after the labeling to allow the labeled blood to reach the imaged slice. A sequence of images with multiple delays is more suitable for quantification of the cerebral blood flow as it gives more information about the blood arrival and relaxation. Although the quantification methods are sensitive to noise, no filtering or only Gaussian filtering is used to denoise the data in the temporal domain prior to quantification. In this article, we propose an efficient way to use the redundancy of information in the time sequence of each pixel to suppress noise. For this purpose, the vectorial NL-means method is adapted to work in the temporal domain. The proposed method is tested on simulated and real 3T MRI data. We demonstrate a clear improvement of the image quality as well as a better performance compared to Gaussian and normal spatial NL-means filtering.

  16. Spatio-Temporal Video Object Segmentation via Scale-Adaptive 3D Structure Tensor

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    Hai-Yun Wang

    2004-06-01

    Full Text Available To address multiple motions and deformable objects' motions encountered in existing region-based approaches, an automatic video object (VO segmentation methodology is proposed in this paper by exploiting the duality of image segmentation and motion estimation such that spatial and temporal information could assist each other to jointly yield much improved segmentation results. The key novelties of our method are (1 scale-adaptive tensor computation, (2 spatial-constrained motion mask generation without invoking dense motion-field computation, (3 rigidity analysis, (4 motion mask generation and selection, and (5 motion-constrained spatial region merging. Experimental results demonstrate that these novelties jointly contribute much more accurate VO segmentation both in spatial and temporal domains.

  17. Improving video processing performance using temporal reasoning

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    Ahmed, Mohamed; Karmouch, Ahmed

    1999-10-01

    In this paper, we present a system, called MediABS, for extracting key frames in a video segment. First we will describe the overall architecture of the system and we will show how our system can handle multiple video formats with a single video-processing module. Then we will present a new algorithm, based on color histograms. The algorithm exploits the temporal characteristic of the visual information and provides techniques for avoiding false cuts and eliminating the possibility of missing true cuts. A discussion, along with some results, will be provided to show the merits of our algorithm compared to existing related algorithms. Finally we will discuss the performance (in terms of processing time and accuracy) obtained by our system in extracting the key frames from a video segment. This work is part of the Mobile Agents Alliance project involving University of Ottawa, National Research Council (NRC) and Mitel Corporation.

  18. Improving the privacy of optical steganography with temporal phase masks.

    Science.gov (United States)

    Wang, Z; Fok, M P; Xu, L; Chang, J; Prucnal, P R

    2010-03-15

    Temporal phase modulation of spread stealth signals is proposed and demonstrated to improve optical steganography transmission privacy. After phase modulation, the temporally spread stealth signal has a more complex spectral-phase-temporal relationship, such that the original temporal profile cannot be restored when only dispersion compensation is applied to the temporally spread stealth signals. Therefore, it increases the difficulty for the eavesdropper to detect and intercept the stealth channel that is hidden under a public transmission, even with a correct dispersion compensation device. The experimental results demonstrate the feasibility of this approach and display insignificant degradation in transmission performance, compared to the conventional stealth transmission without temporal phase modulation. The proposed system can also work without a clock transmission for signal synchronization. Our analysis and simulation results show that it is difficult for the adversary to detect the existence of the stealth transmission, or find the correct phase mask to recover the stealth signals.

  19. Temporal and spatial adaptation of transient responses to local features

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    David C O'Carroll

    2012-10-01

    Full Text Available Interpreting visual motion within the natural environment is a challenging task, particularly considering that natural scenes vary enormously in brightness, contrast and spatial structure. Current models for the detection of self-generated optic flow depend heavily on these very parameters, but despite this, animals manage to successfully navigate within a broad range of scenes. Within global scenes local areas with more salient features are common. Recent work has highlighted the influence that local, salient features have on the encoding of optic flow, but it has been difficult to quantify how local transient responses affect responses to subsequent features and thus contribute to the global neural response. To investigate this in more detail we used experimenter-designed stimuli and recorded intracellularly from motion-sensitive neurons. We limited the stimulus to a small vertically elongated strip, to investigate local and global neural responses to pairs of local ‘doublet’ features that were designed to interact with each other in the temporal and spatial domain. We show that the passage of a high contrast doublet feature produces a complex transient response from local motion detectors consistent with predictions of a simple computational model. In the neuron, the passage of a high-contrast feature induces a local reduction in responses to subsequent low contrast features. However, this neural contrast gain reduction appears to be recruited only when features stretch vertically (i.e. orthogonal to the direction of motion across at least several aligned neighbouring ommatidia. Horizontal displacement of the components of elongated features abolishes the local adaptation effect. It is thus likely that features in natural scenes with vertically aligned edges, such as tree trunks, would be expected to recruit the greatest amount of response suppression, which could emphasize the local responses to such features vs those in nearby texture

  20. The Experience of Fluid Temporality in Adaptive Lighting Environments

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper;

    2013-01-01

    an activity space, where the temporal is a crucial part of the negotiation of place and presence. The paper will approach the temporal complexity from two perspectives: (1) from an analytic position within the experiential moment using expert performance practice, and (2) unpacking the qualitative parameters...

  1. Realigning thunder and lightning: temporal adaptation to spatiotemporally distant events.

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    Jordi Navarra

    Full Text Available The brain is able to realign asynchronous signals that approximately coincide in both space and time. Given that many experience-based links between visual and auditory stimuli are established in the absence of spatiotemporal proximity, we investigated whether or not temporal realignment arises in these conditions. Participants received a 3-min exposure to visual and auditory stimuli that were separated by 706 ms and appeared either from the same (Experiment 1 or from different spatial positions (Experiment 2. A simultaneity judgment task (SJ was administered right afterwards. Temporal realignment between vision and audition was observed, in both Experiment 1 and 2, when comparing the participants' SJs after this exposure phase with those obtained after a baseline exposure to audiovisual synchrony. However, this effect was present only when the visual stimuli preceded the auditory stimuli during the exposure to asynchrony. A similar pattern of results (temporal realignment after exposure to visual-leading asynchrony but not after exposure to auditory-leading asynchrony was obtained using temporal order judgments (TOJs instead of SJs (Experiment 3. Taken together, these results suggest that temporal recalibration still occurs for visual and auditory stimuli that fall clearly outside the so-called temporal window for multisensory integration and appear from different spatial positions. This temporal realignment may be modulated by long-term experience with the kind of asynchrony (vision-leading that we most frequently encounter in the outside world (e.g., while perceiving distant events.

  2. Controling contagious processes on temporal networks via adaptive rewiring

    CERN Document Server

    Belik, Vitaly; Hövel, Philipp

    2015-01-01

    We consider recurrent contagious processes on a time-varying network. As a control procedure to mitigate the epidemic, we propose an adaptive rewiring mechanism for temporary isolation of infected nodes upon their detection. As a case study, we investigate the network of pig trade in Germany. Based on extensive numerical simulations for a wide range of parameters, we demonstrate that the adaptation mechanism leads to a significant extension of the parameter range, for which most of the index nodes (origins of the epidemic) lead to vanishing epidemics. We find that diseases with detection times around a week and infectious periods up to 3 months can be effectively controlled. Furthermore the performance of adaptation is very heterogeneous with respect to the index node. We identify index nodes that are most responsive to the adaptation strategy and quantify the success of the proposed adaptation scheme in dependence on the infectious period and detection times.

  3. Improvement of Adaptive Cruise Control Performance

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    Nakagami Takashi

    2010-01-01

    Full Text Available This paper describes the Adaptive Cruise Control system (ACC, a system which reduces the driving burden on the driver. The ACC system primarily supports four driving modes on the road and controls the acceleration and deceleration of the vehicle in order to maintain a set speed or to avoid a crash. This paper proposes more accurate methods of detecting the preceding vehicle by radar while cornering, with consideration for the vehicle sideslip angle, and also of controlling the distance between vehicles. By making full use of the proposed identification logic for preceding vehicles and path estimation logic, an improvement in driving stability was achieved.

  4. Flicker Adaptation of Low-Level Cortical Visual Neurons Contributes to Temporal Dilation

    Science.gov (United States)

    Ortega, Laura; Guzman-Martinez, Emmanuel; Grabowecky, Marcia; Suzuki, Satoru

    2012-01-01

    Several seconds of adaptation to a flickered stimulus causes a subsequent brief static stimulus to appear longer in duration. Nonsensory factors, such as increased arousal and attention, have been thought to mediate this flicker-based temporal-dilation aftereffect. In this study, we provide evidence that adaptation of low-level cortical visual…

  5. An Auditory Model of Improved Adaptive ZCPA

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    Jinping Zhang

    2013-07-01

    Full Text Available An improved ZCAP auditory model with adaptability is proposed in this paper, and the  adaptive method designed for ZCPA model is suitable for other auditory model with inner-hair-cell sub-model. The first step in the implement process of the proposed ZCPA model is to carry out the calculation of inner product between signal and complex Gammatone filters to obtain important frequency components  of signal. And then, according to  the result of the first step, the parameters of the basilar membrane sub-model and frequency box are automatically adjusted, such as the number of the basilar membrane filters, center frequency and bandwith of each basilar membrane filter, position of each frequency box, and so on. Lastly  an auditory model is built, and the final output is auditory spectrum.The results of numerical simulation and experiments have showed that the proposed model could realize accurate frequency selection, and the auditory spectrum is more distinctly than that of conventional ZCPA model. Moreover, the proposed model can completely avoided the influence of the number of filter on the shape of auditory spectrum existing in conventional ZCPA model so that the shape of auditory spectrum is steady, and the data quantity is small.

  6. Evolution of spatio-temporal drought characteristics: validation, projections and effect of adaptation scenarios

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    J.-P. Vidal

    2012-02-01

    Full Text Available Drought events develop in both space and time and they are therefore best described through summary joint spatio-temporal characteristics, like mean duration, mean affected area and total magnitude. This paper addresses the issue of future projections of such characteristics of drought events over France through three main research questions: (1 are downscaled climate projections able to reproduce spatio-temporal characteristics of meteorological and agricultural droughts in France over a present-day period? (2 How such characteristics will evolve over the 21st century? (3 How to use standardized drought indices to represent theoretical adaptation scenarios? These questions are addressed using the Isba land surface model, downscaled climate projections from the ARPEGE General Circulation Model under three emissions scenarios, as well as results from a previously performed 50-yr multilevel and multiscale drought reanalysis over France. Spatio-temporal characteristics of meteorological and agricultural drought events are computed using the Standardized Precipitation Index and the Standardized Soil Wetness Index, respectively, and for time scales of 3 and 12 months. Results first show that the distributions of joint spatio-temporal characteristics of observed events are well reproduced by the downscaled hydroclimate projections over a present-day period. All spatio-temporal characteristics of drought events are then found to dramatically increase over the 21st century, with stronger changes for agricultural droughts. Two theoretical adaptation scenarios are eventually built based on hypotheses of adaptation to evolving climate and hydrological normals, either retrospective or prospective, and by taking advantage of the statistical properties of the standardized drought indices. The perceived spatio-temporal characteristics of drought events derived from these theoretical adaptation scenarios show much reduced changes, but they call for more

  7. Evolution of spatio-temporal drought characteristics: validation, projections and effect of adaptation scenarios

    Directory of Open Access Journals (Sweden)

    J.-P. Vidal

    2012-08-01

    Full Text Available Drought events develop in both space and time and they are therefore best described through summary joint spatio-temporal characteristics, such as mean duration, mean affected area and total magnitude. This paper addresses the issue of future projections of such characteristics of drought events over France through three main research questions: (1 Are downscaled climate projections able to simulate spatio-temporal characteristics of meteorological and agricultural droughts in France over a present-day period? (2 How such characteristics will evolve over the 21st century? (3 How to use standardized drought indices to represent theoretical adaptation scenarios? These questions are addressed using the Isba land surface model, downscaled climate projections from the ARPEGE General Circulation Model under three emissions scenarios, as well as results from a previously performed 50-yr multilevel and multiscale drought reanalysis over France. Spatio-temporal characteristics of meteorological and agricultural drought events are computed using the Standardized Precipitation Index and the Standardized Soil Wetness Index, respectively, and for time scales of 3 and 12 months. Results first show that the distributions of joint spatio-temporal characteristics of observed events are well simulated by the downscaled hydroclimate projections over a present-day period. All spatio-temporal characteristics of drought events are then found to dramatically increase over the 21st century, with stronger changes for agricultural droughts. Two theoretical adaptation scenarios are eventually built based on hypotheses of adaptation to evolving climate and hydrological normals, either retrospective or prospective. The perceived spatio-temporal characteristics of drought events derived from these theoretical adaptation scenarios show much reduced changes, but they call for more realistic scenarios at both the catchment and national scale in order to accurately assess the

  8. Improving information for community-based adaptation

    Energy Technology Data Exchange (ETDEWEB)

    Huq, Saleemul

    2011-10-15

    Community-based adaptation aims to empower local people to cope with and plan for the impacts of climate change. In a world where knowledge equals power, you could be forgiven for thinking that enabling this type of adaptation boils down to providing local people with information. Conventional approaches to planning adaptation rely on 'expert' advice and credible 'science' from authoritative information providers such as the Intergovernmental Panel on Climate Change. But to truly support the needs of local communities, this information needs to be more site-specific, more user-friendly and more inclusive of traditional knowledge and existing coping practices.

  9. Evolutionary adaptations for the temporal processing of natural sounds by the anuran peripheral auditory system.

    Science.gov (United States)

    Schrode, Katrina M; Bee, Mark A

    2015-03-01

    Sensory systems function most efficiently when processing natural stimuli, such as vocalizations, and it is thought that this reflects evolutionary adaptation. Among the best-described examples of evolutionary adaptation in the auditory system are the frequent matches between spectral tuning in both the peripheral and central auditory systems of anurans (frogs and toads) and the frequency spectra of conspecific calls. Tuning to the temporal properties of conspecific calls is less well established, and in anurans has so far been documented only in the central auditory system. Using auditory-evoked potentials, we asked whether there are species-specific or sex-specific adaptations of the auditory systems of gray treefrogs (Hyla chrysoscelis) and green treefrogs (H. cinerea) to the temporal modulations present in conspecific calls. Modulation rate transfer functions (MRTFs) constructed from auditory steady-state responses revealed that each species was more sensitive than the other to the modulation rates typical of conspecific advertisement calls. In addition, auditory brainstem responses (ABRs) to paired clicks indicated relatively better temporal resolution in green treefrogs, which could represent an adaptation to the faster modulation rates present in the calls of this species. MRTFs and recovery of ABRs to paired clicks were generally similar between the sexes, and we found no evidence that males were more sensitive than females to the temporal modulation patterns characteristic of the aggressive calls used in male-male competition. Together, our results suggest that efficient processing of the temporal properties of behaviorally relevant sounds begins at potentially very early stages of the anuran auditory system that include the periphery. PMID:25617467

  10. Evolutionary adaptations for the temporal processing of natural sounds by the anuran peripheral auditory system.

    Science.gov (United States)

    Schrode, Katrina M; Bee, Mark A

    2015-03-01

    Sensory systems function most efficiently when processing natural stimuli, such as vocalizations, and it is thought that this reflects evolutionary adaptation. Among the best-described examples of evolutionary adaptation in the auditory system are the frequent matches between spectral tuning in both the peripheral and central auditory systems of anurans (frogs and toads) and the frequency spectra of conspecific calls. Tuning to the temporal properties of conspecific calls is less well established, and in anurans has so far been documented only in the central auditory system. Using auditory-evoked potentials, we asked whether there are species-specific or sex-specific adaptations of the auditory systems of gray treefrogs (Hyla chrysoscelis) and green treefrogs (H. cinerea) to the temporal modulations present in conspecific calls. Modulation rate transfer functions (MRTFs) constructed from auditory steady-state responses revealed that each species was more sensitive than the other to the modulation rates typical of conspecific advertisement calls. In addition, auditory brainstem responses (ABRs) to paired clicks indicated relatively better temporal resolution in green treefrogs, which could represent an adaptation to the faster modulation rates present in the calls of this species. MRTFs and recovery of ABRs to paired clicks were generally similar between the sexes, and we found no evidence that males were more sensitive than females to the temporal modulation patterns characteristic of the aggressive calls used in male-male competition. Together, our results suggest that efficient processing of the temporal properties of behaviorally relevant sounds begins at potentially very early stages of the anuran auditory system that include the periphery.

  11. Recurrent coupling improves discrimination of temporal spike patterns

    Directory of Open Access Journals (Sweden)

    Chun-Wei eYuan

    2012-05-01

    Full Text Available Despite the ubiquitous presence of recurrent synaptic connections insensory neuronal systems, their general functional purpose is not wellunderstood. A recent conceptual advance has been achieved by theoriesof reservoir computing in which recurrent networks have been proposedto generate short-term memory as well as to improve neuronalrepresentation of the sensory input for subsequent computations.Here, we present a numerical study on the distinct effects ofinhibitory and excitatory recurrence in a canonical linearclassification task. It is found that both types of coupling improvethe ability to discriminate temporal spike patterns as compared to apurely feed-forward system, although in different ways. For a largeclass of inhibitory networks, the network's performance is optimal aslong as a fraction of roughly 50% of neurons per stimulus is activein the resulting population code. Thereby the contribution of inactiveneurons to the neural code is found to be even more informative thanthat of the active neurons, generating an inherent robustness ofclassification performance against temporal jitter of the inputspikes. Excitatory couplings are found to not only produce ashort-term memory buffer but also to improve linear separability ofthe population patterns by evoking more irregular firing as comparedto the purely inhibitory case. As the excitatory connectivity becomesmore sparse, firing becomes more variable and pattern separabilityimproves. We argue that the proposed paradigm is particularlywell-suited as a conceptual framework for processing of sensoryinformation in the auditory pathway.

  12. Video Enhancement Using Adaptive Spatio-Temporal Connective Filter and Piecewise Mapping

    Directory of Open Access Journals (Sweden)

    Shi-Qiang Yang

    2008-06-01

    Full Text Available This paper presents a novel video enhancement system based on an adaptive spatio-temporal connective (ASTC noise filter and an adaptive piecewise mapping function (APMF. For ill-exposed videos or those with much noise, we first introduce a novel local image statistic to identify impulse noise pixels, and then incorporate it into the classical bilateral filter to form ASTC, aiming to reduce the mixture of the most two common types of noises—Gaussian and impulse noises in spatial and temporal directions. After noise removal, we enhance the video contrast with APMF based on the statistical information of frame segmentation results. The experiment results demonstrate that, for diverse low-quality videos corrupted by mixed noise, underexposure, overexposure, or any mixture of the above, the proposed system can automatically produce satisfactory results.

  13. Video Enhancement Using Adaptive Spatio-Temporal Connective Filter and Piecewise Mapping

    Directory of Open Access Journals (Sweden)

    Wang Chao

    2008-01-01

    Full Text Available This paper presents a novel video enhancement system based on an adaptive spatio-temporal connective (ASTC noise filter and an adaptive piecewise mapping function (APMF. For ill-exposed videos or those with much noise, we first introduce a novel local image statistic to identify impulse noise pixels, and then incorporate it into the classical bilateral filter to form ASTC, aiming to reduce the mixture of the most two common types of noises—Gaussian and impulse noises in spatial and temporal directions. After noise removal, we enhance the video contrast with APMF based on the statistical information of frame segmentation results. The experiment results demonstrate that, for diverse low-quality videos corrupted by mixed noise, underexposure, overexposure, or any mixture of the above, the proposed system can automatically produce satisfactory results.

  14. Codifying temporal characteristics of Jewett components to improve Jewett transform

    International Nuclear Information System (INIS)

    Jewett Transform is not yet, it is being. First ideas on this metaphor are from 1980 while monitoring cerebral function. It was conceived in contrast with Fourier Transform. Its application is limited to Auditory Brain Stem Responses. It uses a non-orthogonal physiologically rooted basis. Non-orthogonal basis has limited power in front of orthogonal basis: no analytical method exists to evaluate the corresponding transforms and numerical methods are required. In previous works, numerical methods were replaced for by trained artificial neural networks. Jewett transform was applied to increase the training set. Being a physiologically inspired basis, it promises better understanding of analysis of these evoked responses. It is envisioned that diverse new transforms, tailored to different problem specificity are to emerge. Considering the short temporal influence of Jewett components, it is stated that codifying temporal characteristics of Jewett components can be used to improve Jewett Transform. Previously used neural network was modified. Output vector codes are built up by grouping components instead of grouping parameters. This allows synaptic pruning in the artificial neural network. Only a fraction (0.49) of the previous network weights is used. Mean square error in fitting signal to model are acceptable (mean ε<0.3%, n= 600). Memorization is eliminated

  15. Adaptive Landing Gear: Optimum Control Strategy and Potential for Improvement

    OpenAIRE

    Grzegorz Mikułowski; Łukasz Jankowski

    2009-01-01

    An adaptive landing gear is a landing gear (LG) capable of active adaptation to particular landing conditions by means of controlled hydraulic force. The objective of the adaptive control is to mitigate the peak force transferred to the aircraft structure during touch-down, and thus to limit the structural fatigue factor. This paper investigates the ultimate limits for improvement due to various strategies of active control. Five strategies are proposed and investigated numerically using a~va...

  16. An Adaptive Middleware for Improved Computational Performance

    DEFF Research Database (Denmark)

    Bonnichsen, Lars Frydendal

    The performance improvements in computer systems over the past 60 years have been fueled by an exponential increase in energy efficiency. In recent years, the phenomenon known as the end of Dennard’s scaling has slowed energy efficiency improvements — but improving computer energy efficiency...... and execution time. Our middleware consists of a new power manager, synchronization libraries using hardware transactional memory (for locks, barriers, and task synchronization), and two concurrent map data structures, which can be deployed in computer systems with little to no effort. At a fundamental level...... is more important now than ever. Traditionally, most improvements in computer energy efficiency have come from improvements in lithography — the ability to produce smaller transistors — and computer architecture - the ability to apply those transistors efficiently. Since the end of scaling, we have seen...

  17. Spatial and temporal aspects of chromatic adaptation and their functional significance for colour constancy.

    Science.gov (United States)

    Werner, Annette

    2014-11-01

    Illumination in natural scenes changes at multiple temporal and spatial scales: slow changes in global illumination occur in the course of a day, and we encounter fast and localised illumination changes when visually exploring the non-uniform light field of three-dimensional scenes; in addition, very long-term chromatic variations may come from the environment, like for example seasonal changes. In this context, I consider the temporal and spatial properties of chromatic adaptation and discuss their functional significance for colour constancy in three-dimensional scenes. A process of fast spatial tuning in chromatic adaptation is proposed as a possible sensory mechanism for linking colour constancy to the spatial structure of a scene. The observed middlewavelength selectivity of this process is particularly suitable for adaptation to the mean chromaticity and the compensation of interreflections in natural scenes. Two types of sensory colour constancy are distinguished, based on the functional differences of their temporal and spatial scales: a slow type, operating at a global scale for the compensation of the ambient illumination; and a fast colour constancy, which is locally restricted and well suited to compensate region-specific variations in the light field of three dimensional scenes. PMID:25449338

  18. “Lucky Averaging”: Quality improvement on Adaptive Optics Scanning Laser Ophthalmoscope Images

    OpenAIRE

    Huang, Gang; Zhong, Zhangyi; Zou, Weiyao; Burns, Stephen A.

    2011-01-01

    Adaptive optics(AO) has greatly improved retinal image resolution. However, even with AO, temporal and spatial variations in image quality still occur due to wavefront fluctuations, intra-frame focus shifts and other factors. As a result, aligning and averaging images can produce a mean image that has lower resolution or contrast than the best images within a sequence. To address this, we propose an image post-processing scheme called “lucky averaging”, analogous to lucky imaging (Fried, 1978...

  19. Adaption of the temporal correlation coefficient calculation for temporal networks (applied to a real-world pig trade network).

    Science.gov (United States)

    Büttner, Kathrin; Salau, Jennifer; Krieter, Joachim

    2016-01-01

    The average topological overlap of two graphs of two consecutive time steps measures the amount of changes in the edge configuration between the two snapshots. This value has to be zero if the edge configuration changes completely and one if the two consecutive graphs are identical. Current methods depend on the number of nodes in the network or on the maximal number of connected nodes in the consecutive time steps. In the first case, this methodology breaks down if there are nodes with no edges. In the second case, it fails if the maximal number of active nodes is larger than the maximal number of connected nodes. In the following, an adaption of the calculation of the temporal correlation coefficient and of the topological overlap of the graph between two consecutive time steps is presented, which shows the expected behaviour mentioned above. The newly proposed adaption uses the maximal number of active nodes, i.e. the number of nodes with at least one edge, for the calculation of the topological overlap. The three methods were compared with the help of vivid example networks to reveal the differences between the proposed notations. Furthermore, these three calculation methods were applied to a real-world network of animal movements in order to detect influences of the network structure on the outcome of the different methods. PMID:27026862

  20. Adaptive Filtering Queueing for Improving Fairness

    Directory of Open Access Journals (Sweden)

    Jui-Pin Yang

    2015-06-01

    Full Text Available In this paper, we propose a scalable and efficient Active Queue Management (AQM scheme to provide fair bandwidth sharing when traffic is congested dubbed Adaptive Filtering Queueing (AFQ. First, AFQ identifies the filtering level of an arriving packet by comparing it with a flow label selected at random from the first level to an estimated level in the filtering level table. Based on the accepted traffic estimation and the previous fair filtering level, AFQ updates the fair filtering level. Next, AFQ uses a simple packet-dropping algorithm to determine whether arriving packets are accepted or discarded. To enhance AFQ’s feasibility in high-speed networks, we propose a two-layer mapping mechanism to effectively simplify the packet comparison operations. Simulation results demonstrate that AFQ achieves optimal fairness when compared with Rotating Preference Queues (RPQ, Core-Stateless Fair Queueing (CSFQ, CHOose and Keep for responsive flows, CHOose and Kill for unresponsive flows (CHOKe and First-In First-Out (FIFO schemes under a variety of traffic conditions.

  1. Adaptively measuring the temporal shape of ultrashort single photons for higher-dimensional quantum information processing

    CERN Document Server

    Polycarpou, Constantina; Venturi, Giovanni; Zavatta, Alessandro; Bellini, Marco

    2011-01-01

    A photon is the single excitation of a particular spatiotemporal mode of the electromagnetic field. A precise knowledge of the mode structure is therefore essential for its processing and detection, as well as for applying generic quantum light states to novel technologies. Here we demonstrate an adaptive scheme for reconstructing the arbitrary amplitude and phase spectro-temporal profile of an ultrashort single-photon pulse. The method combines techniques from the fields of ultrafast coherent control and quantum optics to map the mode of a fragile quantum state onto that of an intense coherent field. In addition, we show that the possibility of generating and detecting quantum states in multiple spectro-temporal modes may serve as a basis for encoding qubits (and qudits) into single, broadband, ultrashort, photons. Providing access to a much larger Hilbert space, this scheme may boost the capacity of current quantum information protocols.

  2. Optic flow improves adaptability of spatiotemporal characteristics during split-belt locomotor adaptation with tactile stimulation.

    Science.gov (United States)

    Eikema, Diderik Jan A; Chien, Jung Hung; Stergiou, Nicholas; Myers, Sara A; Scott-Pandorf, Melissa M; Bloomberg, Jacob J; Mukherjee, Mukul

    2016-02-01

    similar in the two groups, suggesting that temporal parameters are not modified by optic flow. However, whereas the TC group displayed significant stance time asymmetries during the post-treadmill session, such aftereffects were absent in the VRT group. The results indicated that the enhanced transfer resulting from exposure to plantar cutaneous vibration during adaptation was alleviated by optic flow information. The presence of visual self-motion information may have reduced proprioceptive gain during learning. Thus, during overground walking, the learned proprioceptive split-belt pattern is more rapidly overridden by visual input due to its increased relative gain. The results suggest that when visual stimulation is provided during adaptive training, the system acquires the novel movement dynamics while maintaining the ability to flexibly adapt to different environments. PMID:26525712

  3. Temporal Scalability through Adaptive -Band Filter Banks for Robust H.264/MPEG-4 AVC Video Coding

    Directory of Open Access Journals (Sweden)

    Pau G

    2006-01-01

    Full Text Available This paper presents different structures that use adaptive -band hierarchical filter banks for temporal scalability. Open-loop and closed-loop configurations are introduced and illustrated using existing video codecs. In particular, it is shown that the H.264/MPEG-4 AVC codec allows us to introduce scalability by frame shuffling operations, thus keeping backward compatibility with the standard. The large set of shuffling patterns introduced here can be exploited to adapt the encoding process to the video content features, as well as to the user equipment and transmission channel characteristics. Furthermore, simulation results show that this scalability is obtained with no degradation in terms of subjective and objective quality in error-free environments, while in error-prone channels the scalable versions provide increased robustness.

  4. Microgeographical population structure and adaptation in Atlantic cod Gadus morhua: spatio-temporal insights from gene-associated DNA markers

    DEFF Research Database (Denmark)

    Poulsen, Nina Aagaard; Hemmer-Hansen, Jakob; Loeschcke, V.;

    2011-01-01

    Recent technical advances have stimulated studies on spatial scales of adaptive genetic variation in marine fishes. However, very few studies have combined spatial and temporal sampling to investigate adaptive genetic structuring at local and microgeographical scales, i.e. scales at which neutral...

  5. Adaptation to Temporally Fluctuating Environments by the Evolution of Maternal Effects.

    Directory of Open Access Journals (Sweden)

    Snigdhadip Dey

    2016-02-01

    Full Text Available All organisms live in temporally fluctuating environments. Theory predicts that the evolution of deterministic maternal effects (i.e., anticipatory maternal effects or transgenerational phenotypic plasticity underlies adaptation to environments that fluctuate in a predictably alternating fashion over maternal-offspring generations. In contrast, randomizing maternal effects (i.e., diversifying and conservative bet-hedging, are expected to evolve in response to unpredictably fluctuating environments. Although maternal effects are common, evidence for their adaptive significance is equivocal since they can easily evolve as a correlated response to maternal selection and may or may not increase the future fitness of offspring. Using the hermaphroditic nematode Caenorhabditis elegans, we here show that the experimental evolution of maternal glycogen provisioning underlies adaptation to a fluctuating normoxia-anoxia hatching environment by increasing embryo survival under anoxia. In strictly alternating environments, we found that hermaphrodites evolved the ability to increase embryo glycogen provisioning when they experienced normoxia and to decrease embryo glycogen provisioning when they experienced anoxia. At odds with existing theory, however, populations facing irregularly fluctuating normoxia-anoxia hatching environments failed to evolve randomizing maternal effects. Instead, adaptation in these populations may have occurred through the evolution of fitness effects that percolate over multiple generations, as they maintained considerably high expected growth rates during experimental evolution despite evolving reduced fecundity and reduced embryo survival under one or two generations of anoxia. We develop theoretical models that explain why adaptation to a wide range of patterns of environmental fluctuations hinges on the existence of deterministic maternal effects, and that such deterministic maternal effects are more likely to contribute to

  6. Adaptation to Temporally Fluctuating Environments by the Evolution of Maternal Effects.

    Science.gov (United States)

    Dey, Snigdhadip; Proulx, Stephen R; Teotónio, Henrique

    2016-02-01

    All organisms live in temporally fluctuating environments. Theory predicts that the evolution of deterministic maternal effects (i.e., anticipatory maternal effects or transgenerational phenotypic plasticity) underlies adaptation to environments that fluctuate in a predictably alternating fashion over maternal-offspring generations. In contrast, randomizing maternal effects (i.e., diversifying and conservative bet-hedging), are expected to evolve in response to unpredictably fluctuating environments. Although maternal effects are common, evidence for their adaptive significance is equivocal since they can easily evolve as a correlated response to maternal selection and may or may not increase the future fitness of offspring. Using the hermaphroditic nematode Caenorhabditis elegans, we here show that the experimental evolution of maternal glycogen provisioning underlies adaptation to a fluctuating normoxia-anoxia hatching environment by increasing embryo survival under anoxia. In strictly alternating environments, we found that hermaphrodites evolved the ability to increase embryo glycogen provisioning when they experienced normoxia and to decrease embryo glycogen provisioning when they experienced anoxia. At odds with existing theory, however, populations facing irregularly fluctuating normoxia-anoxia hatching environments failed to evolve randomizing maternal effects. Instead, adaptation in these populations may have occurred through the evolution of fitness effects that percolate over multiple generations, as they maintained considerably high expected growth rates during experimental evolution despite evolving reduced fecundity and reduced embryo survival under one or two generations of anoxia. We develop theoretical models that explain why adaptation to a wide range of patterns of environmental fluctuations hinges on the existence of deterministic maternal effects, and that such deterministic maternal effects are more likely to contribute to adaptation than

  7. Adaptation to Temporally Fluctuating Environments by the Evolution of Maternal Effects.

    Science.gov (United States)

    Dey, Snigdhadip; Proulx, Stephen R; Teotónio, Henrique

    2016-02-01

    All organisms live in temporally fluctuating environments. Theory predicts that the evolution of deterministic maternal effects (i.e., anticipatory maternal effects or transgenerational phenotypic plasticity) underlies adaptation to environments that fluctuate in a predictably alternating fashion over maternal-offspring generations. In contrast, randomizing maternal effects (i.e., diversifying and conservative bet-hedging), are expected to evolve in response to unpredictably fluctuating environments. Although maternal effects are common, evidence for their adaptive significance is equivocal since they can easily evolve as a correlated response to maternal selection and may or may not increase the future fitness of offspring. Using the hermaphroditic nematode Caenorhabditis elegans, we here show that the experimental evolution of maternal glycogen provisioning underlies adaptation to a fluctuating normoxia-anoxia hatching environment by increasing embryo survival under anoxia. In strictly alternating environments, we found that hermaphrodites evolved the ability to increase embryo glycogen provisioning when they experienced normoxia and to decrease embryo glycogen provisioning when they experienced anoxia. At odds with existing theory, however, populations facing irregularly fluctuating normoxia-anoxia hatching environments failed to evolve randomizing maternal effects. Instead, adaptation in these populations may have occurred through the evolution of fitness effects that percolate over multiple generations, as they maintained considerably high expected growth rates during experimental evolution despite evolving reduced fecundity and reduced embryo survival under one or two generations of anoxia. We develop theoretical models that explain why adaptation to a wide range of patterns of environmental fluctuations hinges on the existence of deterministic maternal effects, and that such deterministic maternal effects are more likely to contribute to adaptation than

  8. AN IMPROVED SUBSPACE TRACKING ALGORITHM FOR BLIND ADAPTIVE MULTIUSER DETECTION

    Institute of Scientific and Technical Information of China (English)

    Xu Changqing; Wang Hongyang; Song Wentao

    2004-01-01

    As the Projection Approximation Subspace Tracking with deflation(PASTd) algorithm is sensitive to impulsive noise, an improved subspace tracking algorithm is proposed and applied to blind adaptive multi-user detection. Simulation results show that the improved PASTd algorithm not only remains the properties of the conventional PASTdalgorithm, but also has good Bit Error Rate(BER) performance in impulsive noise environment, thus it can effectively improve the system performance.

  9. Temporal features of postural adaptation strategy to prolonged and repeatable balance perturbation.

    Science.gov (United States)

    Schmid, Micaela; Sozzi, Stefania

    2016-08-15

    Aim of this study was to get insight into the features of the postural adaptation process, occurring during a continuous 3-min and 0.6Hz horizontal sinusoidal oscillation of the body support base. We hypothesized an ongoing temporal organization of the balancing strategy that gradually becomes fine-tuned and more coordinated with the platform movement. The trial was divided into oscillation cycles and for each cycle: leg muscles activity and temporal relationship between Centre of Mass and Centre of Pressure A-P position were analyzed. The results of each cycle were grouped in time-windows of 10 successive cycles (time windows of 16.6s). Muscle activity was initially prominent and diminished progressively. The major burst of Tibialis Anterior (TA) muscle always occurred at the same time instant of the platform oscillation cycle, in advance with respect to the platform posterior turning point. This burst produced a body forward rotation that was delayed throughout the task. During prolonged and repeatable balance perturbation, an ongoing postural adaptation process occurs. When the effects of the perturbation become predictable, the CNS scales the level of muscle activity to counteracting the destabilizing effects of the perturbations. Furthermore, the CNS tunes the kinematics and the kinetic responses optimally by slightly delaying the onset of the body forward rotation, maintaining unchanged the time-pattern of postural muscle activation. PMID:27291456

  10. Adaptive Landing Gear: Optimum Control Strategy and Potential for Improvement

    Directory of Open Access Journals (Sweden)

    Grzegorz Mikułowski

    2009-01-01

    Full Text Available An adaptive landing gear is a landing gear (LG capable of active adaptation to particular landing conditions by means of controlled hydraulic force. The objective of the adaptive control is to mitigate the peak force transferred to the aircraft structure during touch-down, and thus to limit the structural fatigue factor. This paper investigates the ultimate limits for improvement due to various strategies of active control. Five strategies are proposed and investigated numerically using a~validated model of a real, passive landing gear as a reference. Potential for improvement is estimated statistically in terms of the mean and median (significant peak strut forces as well as in terms of the extended safe sinking velocity range. Three control strategies are verified experimentally using a laboratory test stand.

  11. Improved Step Size Adaptation for the MO-CMA-ES

    DEFF Research Database (Denmark)

    Voß, T.; Hansen, N.; Igel, Christian

    2010-01-01

    . The new step size adaptation improves the performance of the MO-CMA-ES as shown empirically using a large set of benchmark functions. The new update scheme in general leads to larger step sizes and thereby counteracts premature convergence. The experiments comprise the first evaluation of the MO......-CMA-ES for problems with more than two objectives....

  12. Adaptive data analysis for characterizing the temporal variability of the solar resource

    Science.gov (United States)

    Bengulescu, Marc; Blanc, Philippe; Wald, Lucien

    2016-04-01

    One of the key challenges associated with the large-scale penetration of solar power is the inherent spatio-temporal variability of the solar radiation impinging on the surface. Particular methods are currently employed to measure, estimate or forecast the extent and availability of the solar resource depending on the effective spatial and temporal scales of interest, such as numerical weather prediction models, satellite-based estimates, sky-imagers or in-situ ground measurements. Here we present a method for characterizing the intrinsic time-scales of the solar resource variability. The study deals with decennial time-series of daily values of the surface solar irradiance (SSI) issued from high-quality BSRN ground measurement stations. Geophysical signals, such as the SSI time-series under scrutiny, are often the result of non-linear interactions of physical processes that are also often under natural or anthropogenic non-stationary forcings. Therefore, an adaptive data analysis technique is employed that makes no beforehand assumptions about the data: neither linearity, nor stationarity of the signal is assumed. The method, called the Hilbert-Huang transform, first extracts all the embedded oscillations that have a similar time-scale, to which it then applies Hilbert spectral analysis. A time-frequency-energy representation of the signal is thus constructed, which reveals the time-varying character of the intrinsic temporal scales of variability (frequency modulation), along with any fluctuations in the intensity of the signal at the corresponding scale (amplitude modulation). In order to test whether the features extracted from the data are the expression of deterministic physical processes, as opposed to being stochastic realizations of various background processes (i.e. noise), a novel, adaptive null-hypothesis based on the statistical properties of noise is employed. It is shown that the data, irrespective of the geographical conditions, shares common time

  13. Accelerated long-term forgetting in temporal lobe epilepsy: evidence of improvement after left temporal pole lobectomy.

    Science.gov (United States)

    Gallassi, Roberto; Sambati, Luisa; Poda, Roberto; Stanzani Maserati, Michelangelo; Oppi, Federico; Giulioni, Marco; Tinuper, Paolo

    2011-12-01

    Accelerated long term forgetting (ALF) is a characteristic cognitive aspect in patients affected by temporal lobe epilepsy that is probably due to an impairment of memory consolidation and retrieval caused by epileptic activity in hippocampal and parahippocampal regions. We describe a case of a patient with TLE who showed improvement in ALF and in remote memory impairment after an anterior left temporal pole lobectomy including the uncus and amygdala. Our findings confirm that impairment of hippocampal functioning leads to pathological ALF, whereas restoration of hippocampal functioning brings ALF to a level comparable to that of controls.

  14. Relativistic Flows Using Spatial and Temporal Adaptive Structured Mesh Refinement. I. Hydrodynamics

    CERN Document Server

    Wang, Peng; Zhang, Weiqun

    2007-01-01

    Astrophysical relativistic flow problems require high resolution three-dimensional numerical simulations. In this paper, we describe a new parallel three-dimensional code for simulations of special relativistic hydrodynamics (SRHD) using both spatially and temporally structured adaptive mesh refinement (AMR). We used method of lines to discrete SRHD equations spatially and used a total variation diminishing (TVD) Runge-Kutta scheme for time integration. For spatial reconstruction, we have implemented piecewise linear method (PLM), piecewise parabolic method (PPM), third order convex essentially non-oscillatory (CENO) and third and fifth order weighted essentially non-oscillatory (WENO) schemes. Flux is computed using either direct flux reconstruction or approximate Riemann solvers including HLL, modified Marquina flux, local Lax-Friedrichs flux formulas and HLLC. The AMR part of the code is built on top of the cosmological Eulerian AMR code {\\sl enzo}, which uses the Berger-Colella AMR algorithm and is parall...

  15. À Table! Improving Temporal Navigation in Soccer Ranking Tables

    OpenAIRE

    Perin, Charles; Vuillemot, Romain; Fekete, Jean-Daniel

    2014-01-01

    International audience This article introduces A Table!, an enhanced soccer ranking table providing temporal navigation by combining two novel interaction techniques. Ranking tables order soccer teams represented as rows, according to values of columns containing attributes e.g., accumulated points, or number of scored goals. Because they represent a snapshot of a championship at a time t, tables are regularly updated with new results. Such updates usually change the rows order, which make...

  16. An Improved Adaptive Routing Algorithm Based on Link Analysis

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2012-01-01

    Full Text Available DHT (Distributed Hash Tables has been applied to the structured P2P system to achieve information retrieval and positioning efficiently. KAD is a large-scale network protocol based on the XOR metric in practice, which uses DHT technology to improve network salability without central server. However, the increasing malicious pollutes routing tables to reduce seriously the query performance. Thus, an improved adaptive algorithm based on social network is proposed in order to improve routing table updating algorithm. Firstly, the data structure of routing table is adjusted to store value of centrality and prestige. Secondly, the request nodes can adaptive select nodes to send messages. Then when a find process is terminated, the node will calculate the two values for all participating nodes using the corresponding centrality and prestige algorithms based on XOR metric. Finally, the node updates the routing table depend on the above result. The above algorithm was implemented in an open source project named LibTorrent to test effectiveness. This experiment last a month to verify the change of the search success ratio in a KAD network with about 30% malicious nodes. The results show that the optimized adaptive routing algorithm can effectively resist the attack for routing table and improve the search success ratio of the node. Moreover, this lightweight algorithm is conducive to the deployment in practice without extra network burden.

  17. An improved adaptive wavelet shrinkage for ultrasound despeckling

    Indian Academy of Sciences (India)

    P Nirmala Devi; R Asokan

    2014-08-01

    Ultrasound imaging is the most widely used medical diagnostic technique for clinical decision making, due to its ability to make real time imaging for moving structures, low cost and safety. However, its usefulness is degraded by the presence of signal dependent speckle noise. Several wavelet-based denoising schemes have been reported in the literature for the removal of speckle noise. This study proposes a new and improved adaptive wavelet shrinkage in the translational invariant domain. It exploits the knowledge of the correlation of the wavelet coefficients within and across the resolution scales. A preliminary coefficient classification representing useful image information and noise is performed with a novel inter-scale dependency measure. The spatial context adaptation of the wavelet coefficients within a subband is achieved by a local spatial adaptivity indicator, determined by using a truncation threshold. A weighted signal variance is estimated based on this measure and used in the determination of a subband adaptive threshold. The proposed thresholding function aims to reduce the fixed bias of the soft thresholding approach. Experiments conducted with the proposed filter are compared with the existing filtering algorithms in terms of Peak-Signal to Noise Ratio (PSNR), Mean Square Error (MSE), Structural Similarity IndexMeasure (SSIM), Equivalent Number of Looks (ENL) and Edge Preservation Index (EPI). A comparison of the results shows that the proposed filter achieves an improvement in terms of quantitative measures and in terms of visual quality of the images.

  18. Using a "time machine" to test for local adaptation of aquatic microbes to temporal and spatial environmental variation.

    Science.gov (United States)

    Fox, Jeremy W; Harder, Lawrence D

    2015-01-01

    Local adaptation occurs when different environments are dominated by different specialist genotypes, each of which is relatively fit in its local conditions and relatively unfit under other conditions. Analogously, ecological species sorting occurs when different environments are dominated by different competing species, each of which is relatively fit in its local conditions. The simplest theory predicts that spatial, but not temporal, environmental variation selects for local adaptation (or generates species sorting), but this prediction is difficult to test. Although organisms can be reciprocally transplanted among sites, doing so among times seems implausible. Here, we describe a reciprocal transplant experiment testing for local adaptation or species sorting of lake bacteria in response to both temporal and spatial variation in water chemistry. The experiment used a -80°C freezer as a "time machine." Bacterial isolates and water samples were frozen for later use, allowing transplantation of older isolates "forward in time" and newer isolates "backward in time." Surprisingly, local maladaptation predominated over local adaptation in both space and time. Such local maladaptation may indicate that adaptation, or the analogous species sorting process, fails to keep pace with temporal fluctuations in water chemistry. This hypothesis could be tested with more finely resolved temporal data.

  19. Adaptive temporal and wavefront aberration correction for ultrafast lasers with a membrane deformable mirror

    Science.gov (United States)

    Sherman, Leah Bruner

    Two adaptive optic systems for correction of either temporal phase error and wavefront errors for ultrafast pulses are demonstrated. These systems consists of a computer controlled micromachined membrane deformable mirror (MMDM) and a genetic learning algorithm (GA). Nonlinear excitation such as two-photon fluorescence or second harmonic generation are used as feedback to the GA to determine the appropriate correction to apply to the mirror. Two MMDMs are used, a 30 x 8 mm, 39 actuator linear MMDM for pulse-shaping applications and a 15 mm diameter, 37 actuator wavefront MMDM. Linear pre-compensation of self-phase modulation (SPM) was experimentally demonstrated utilizing the linear MMDM in a linear pulse-shaper for ultrafast pulses. The nonlinear nature of SPM makes arbitrary polynomial compensation necessary. Pre-compensation of SPM generated in an optical fiber by a 10 fs pulse reduced the pulse from 30fs to 20fs. We demonstrates adaptive correction with the wavefront MMDM by corrected for coma and astigmatism in a reflective multiphoton scanning microscope. An f1, parabola produces a very tight focus with no aberration when it is perfectly aligned. However, when beam scanning is used for two-dimensional imaging the image is severely aberrated. The MMDM and the GA are able to find the best possible wavefront for aberration correction for each scanning position. The horizontal scanning range was increased from 60 mum without the adaptive correction to 170 mum, ≈3 times the uncorrected scanning range, and the vertical scanning range was increased by a comparable amount. This resulted in an increase in scanning area of 9 times. The wavefront MMDM was also used for adaptive correction of spherical aberration from focusing from air, deep into a water-based sample. This depth-based aberration results from an index of refraction mismatch between the sample and the immersion medium of the objective and occurs regardless of beam scanning or sample scanning. By

  20. Improvement of flight simulator feeling using adaptive fuzzy backlash compensation

    OpenAIRE

    Amara, Zied; Bordeneuve-Guibé, Joël

    2007-01-01

    In this paper we addressed the problem of improving the control of DC motors used for the specific application of a 3 degrees of freedom moving base flight simulator. Indeed the presence of backlash in DC motors gearboxes induces shocks and naturally limits the flight feeling. In this paper, dynamic inversion with Fuzzy Logic is used to design an adaptive backlash compensator. The classification property of fuzzy logic techniques makes them a natural candidate for the rejection of errors indu...

  1. Dynamically Adaptable Improved OLSR (DA-IOLSR Protocol

    Directory of Open Access Journals (Sweden)

    P.S.Vinayagam,

    2016-05-01

    Full Text Available Optimized Link State Routing (OLSR protocol is a proactive type of routing protocol that uses Multipoint Relay (MPR set as the virtual backbone structure. The existing literature has identified various issues with respect to its backbone structure and has accordingly proposed improvements. In this paper, the focus is on improving the OLSR protocol by employing a Connected Dominating Set (CDS based virtual backbone structure that is dynamically adaptable to rapid topology changes. A new Dynamically Adaptable Improved Optimized Link State Routing (DA-IOLSR protocol is proposed that uses the local topology information to adapt the virtual backbone to topology changes. This assumes significance especially in networks that experience very high mobility. Changes in the network topology caused by node additions, node deletions and node mobility are taken care of. Simulations are carried out to assess the performance of DA-IOLSR protocol and OLSR protocol. Packet delivery achieved by both the protocols is examined under varying mobility by using various combinations of node speed and pause time values. It is found that DA-IOLSR protocol provides better packet delivery as compared to OLSR protocol, under varying mobility conditions.

  2. Improved Adaptive LSB Steganography Based on Chaos and Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yu Lifang

    2010-01-01

    Full Text Available We propose a novel steganographic method in JPEG images with high performance. Firstly, we propose improved adaptive LSB steganography, which can achieve high capacity while preserving the first-order statistics. Secondly, in order to minimize visual degradation of the stego image, we shuffle bits-order of the message based on chaos whose parameters are selected by the genetic algorithm. Shuffling message's bits-order provides us with a new way to improve the performance of steganography. Experimental results show that our method outperforms classical steganographic methods in image quality, while preserving characteristics of histogram and providing high capacity.

  3. Auditory-perceptual learning improves speech motor adaptation in children.

    Science.gov (United States)

    Shiller, Douglas M; Rochon, Marie-Lyne

    2014-08-01

    Auditory feedback plays an important role in children's speech development by providing the child with information about speech outcomes that is used to learn and fine-tune speech motor plans. The use of auditory feedback in speech motor learning has been extensively studied in adults by examining oral motor responses to manipulations of auditory feedback during speech production. Children are also capable of adapting speech motor patterns to perceived changes in auditory feedback; however, it is not known whether their capacity for motor learning is limited by immature auditory-perceptual abilities. Here, the link between speech perceptual ability and the capacity for motor learning was explored in two groups of 5- to 7-year-old children who underwent a period of auditory perceptual training followed by tests of speech motor adaptation to altered auditory feedback. One group received perceptual training on a speech acoustic property relevant to the motor task while a control group received perceptual training on an irrelevant speech contrast. Learned perceptual improvements led to an enhancement in speech motor adaptation (proportional to the perceptual change) only for the experimental group. The results indicate that children's ability to perceive relevant speech acoustic properties has a direct influence on their capacity for sensory-based speech motor adaptation.

  4. Adaptive myoelectric pattern recognition toward improved multifunctional prosthesis control.

    Science.gov (United States)

    Liu, Jie

    2015-04-01

    The non-stationary property of electromyography (EMG) signals in real life settings usually hinders the clinical application of the myoelectric pattern recognition for prosthesis control. The classical EMG pattern recognition approach consists of two separate steps: training and testing, without considering the changes between training and testing data induced by electrode shift, fatigue, impedance changes and psychological factors, and often results in performance degradation. The aim of this study was to develop an adaptive myoelectric pattern recognition system, aiming to retrain the classifier online with the testing data without supervision, providing a self-correction mechanism for suppressing misclassifications. This paper presents an adaptive unsupervised classifier based on support vector machine (SVM) to improve the classification performance. Experimental data from 15 healthy subjects were used to evaluate performance. Preliminary study on intra-session and inter-session EMG data was conducted to verify the performance of the unsupervised adaptive SVM classifier. The unsupervised adaptive SVM classifier outperformed the conventional SVM by 3.3% and 8.0% for the combination of time-domain and autoregressive features in the intra-session and inter-session tests, respectively. The proposed approach is capable of incorporating the useful information in testing data to the classification model by taking into account the overtime changes in the testing data with respect to the training data to retrain the original classifier, therefore providing a self-correction mechanism for suppressing misclassifications.

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

    NARCIS (Netherlands)

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

    2009-01-01

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

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  7. An Improved Adaptive model for Information Recommending and Spreading

    Institute of Scientific and Technical Information of China (English)

    CHEN Duan-Bing; GAO Hui

    2012-01-01

    People in the Internet era have to cope with information overload and expend great effort on finding what they need.Recent experiments indicate that recommendations based on users' past activities are usually less favored than those based on social relationships,and thus many researchers have proposed adaptive algorithms on social recommendation.However,in those methods,quite a number of users have little chance to recommend information,which might prevent valuable information from spreading.We present an improved algorithm that allows more users to have enough followers to spread information.Experimental results demonstrate that both recommendation precision and spreading effectiveness of our method can be improved significantly.%People in the Internet era have to cope with information overload and expend great effort on finding what they need. Recent experiments indicate that recommendations based on users' past activities are usually less favored than those based on social relationships, and thus many researchers have proposed adaptive algorithms on social recommendation. However, in those methods, quite a number of users have little chance to recommend information, which might prevent valuable information from spreading. We present an improved algorithm that allows more users to have enough followers to spread information. Experimental results demonstrate that both recommendation precision and spreading effectiveness of our method can be improved significantly.

  8. Distributed System for Automatic Improvement of Adaptive Website Navigation

    Directory of Open Access Journals (Sweden)

    Željko Eremić

    2012-03-01

    Full Text Available Communication with clients is now largely conducted through websites, whether it comes to business, scientific, or educational activities. Considering that a dynamic website contains a growing amount of information, the issue of efficient navigation through websites allowing quick access to desired content is imperative. Adaptive websites can customize their navigation based on knowledge gained from previous user behaviour. Discovering such knowledge is a process that engages significant resources, and it is convenient to have it organized by the use of one or more servers. This paper describes the architecture of distributed systems for improving navigation through a greater number of adaptive websites. High flexibility, efficiency and reliability of the performance, as well as saving user's time and effort, can be obtained as a result of this system's usage.

  9. Adaptive evolution of synthetic cooperating communities improves growth performance.

    Directory of Open Access Journals (Sweden)

    Xiaolin Zhang

    Full Text Available Symbiotic interactions between organisms are important for human health and biotechnological applications. Microbial mutualism is a widespread phenomenon and is important in maintaining natural microbial communities. Although cooperative interactions are prevalent in nature, little is known about the processes that allow their initial establishment, govern population dynamics and affect evolutionary processes. To investigate cooperative interactions between bacteria, we constructed, characterized, and adaptively evolved a synthetic community comprised of leucine and lysine Escherichia coli auxotrophs. The co-culture can grow in glucose minimal medium only if the two auxotrophs exchange essential metabolites - lysine and leucine (or its precursors. Our experiments showed that a viable co-culture using these two auxotrophs could be established and adaptively evolved to increase growth rates (by ∼3 fold and optical densities. While independently evolved co-cultures achieved similar improvements in growth, they took different evolutionary trajectories leading to different community compositions. Experiments with individual isolates from these evolved co-cultures showed that changes in both the leucine and lysine auxotrophs improved growth of the co-culture. Interestingly, while evolved isolates increased growth of co-cultures, they exhibited decreased growth in mono-culture (in the presence of leucine or lysine. A genome-scale metabolic model of the co-culture was also constructed and used to investigate the effects of amino acid (leucine or lysine release and uptake rates on growth and composition of the co-culture. When the metabolic model was constrained by the estimated leucine and lysine release rates, the model predictions agreed well with experimental growth rates and composition measurements. While this study and others have focused on cooperative interactions amongst community members, the adaptive evolution of communities with other

  10. Improving temporal contrast by cross-polarized wave generation at a sub-petawatt laser facility

    Science.gov (United States)

    Xie, Na; Wang, Xiaodong; Huang, Wanqing; Sun, Li; Guo, Yi; Li, Qing; Zhao, Runchang; Su, Jingqin

    2011-10-01

    Temporal contrast is an important factor affecting the application of ultraintense and ultrashort laser systems. In this paper, we employ cross-polarized wave (XPW) generation to improve the temporal contrast for ultraintense and ultrashort pulses in a 300 TW Ti:Sapphire laser facility, i.e. the super intense laser for experiment on the extremes (SILEX-I). We designed a double chirped-pulse amplification (CPA) system with an intermediate nonlinear temporal pulse filter based on XPW generation and the estimated output energy is more than 300 mJ for the new front-end system. The experimental results show that the output energy of the double CPA system is greater than 370 mJ. The amplified spontaneous emission (ASE) pedestal is suppressed significantly and the temporal contrast is improved by more than two orders of magnitude.

  11. What You See is what You Just Heard: The Effect of Temporal Rate Adaptation on Human Intersensory Perception

    Directory of Open Access Journals (Sweden)

    Carmel Levitan

    2011-10-01

    Full Text Available Previous studies on perception have yet to establish that psychophysical adaptation effects transfer from one sense to another. To test for this phenomenon, the current study examines the possible crossmodal transfer of temporal rate adaptation from vision to audition (VA and from audition to vision (AV. Participants were trained, using feedback, to discriminate the perceived rapidity of either auditory or visual stimuli presented at a range of randomly-ordered frequencies (3.25–4.75 Hz as compared to that of stimuli (of the same modality at a familiar average frequency (4 Hz. Afterwards, subjects were repeatedly exposed to stimuli (of the other modality at a specific rate (3 Hz or 5 Hz. To test whether adaptation resulted from this exposure, subjects again completed the task previously used for training, but now without feedback. After the initial training and adaptation phases, these test and adaptation tasks were presented in 20 alternating blocks. A comparison of the pre- and post-adaptation responses showed crossmodal changes in subjects' perception of temporal rate, such that adaptation to 5 Hz led to the subsequent stimuli seeming slower than they had before adaptation. On the other hand, after exposure to 3 Hz stimuli, the opposite effect was seen. This shift occurred in both VA and AV conditions. As audition and vision were never simultaneously presented, this is suggestive of a strong linkage between the two modalities in perceiving rate. We propose that this is due to the presence of early, distributed, within-modal clocks, that can vigorously modulate each other cross-modally.

  12. GENOMIC APPROACHES FOR IMPROVEMENT OF DROUGHT ADAPTATION IN WHEAT

    Directory of Open Access Journals (Sweden)

    Dénes Dudits

    2008-09-01

    Full Text Available Breeding for yield stability under water limited conditions plays an essential role in the reduction of economic and social consequences of global climate changes. We show that two exotic drought resistant genotypes (Kobomughi and Plainsmann differ in root growth rate, root/shoot ratio, and adaptation to low soil water content. These genotypes exhibit characteristic transcript profiles as shown by barley macroarray studies using 10500 unigenes. Reprogramming of gene expression primarily occurred during the 1-2 weeks of water stress, and 6,1% of tested genes were up-regulated in roots of the more adaptive Plainsmann plants. The time course for expression of gene clusters from Kobomughi genotype revealed a prompt and transient gene activation that can help the survival of plants through function of various defense mechanisms. The aldo-keto reductases (AKRs can detoxify lipid peroxidation products (4-hydroxynon-2-enal and glycolysis-derived reactive aldehydes (metylglyoxal that contribute significantly to cellular damages caused by variety of environmental stresses such as drought, high light intensity, UV-B irradiation, cold. Overproduction of AKRs in transgenic tobacco or wheat plants provides considerable stress tolerance and resistance to methylglyoxal. Several transgenic wheat genotypes have been produced with production of elevated level of AKR enzyme. The drought tolerance of these materials was tested by a complex stress diagnostic system, that integrates imaging of plants and monitoring the leaf temperature and fluorescence induction. Based on these parameters, we can conclude that this transgenic strategy that is based on detoxification of lipid aldehyde can result in improved stress adaptation and reduced yield loss.

  13. Using an Adaptive Genetic Algorithm to Improve Finance Decision

    Institute of Scientific and Technical Information of China (English)

    FaliangGui; TiesongHu

    2004-01-01

    Optimising both qualitative and quantitative factors is a key challenge in solving construction finance decisions. The semi-structured nature of construction finance optimisation problems precludes conventional optimisation techniques. With a desire to improve the performance of the canonical genetic algorithm (CCA) which is characterised by static crossover and mutation probability, and to provide contractors with a profit-risk trade-off curve and cash flow prediction, an adaptive genetic algorithm (AGA) model is developed. Ten projects being undertaken by a major construction firm in Hong Kong were used as case studies to evaluate the performance of the genetic algorithm (CA). The results of case study reveal that the ACA outperformed the CGA both in terms of its quality of solutions and the computational time required for a certain level of accuracy. The results also indicate that there is a potential for using the GA for modelling financial decisions should both quantitative and qualitative factors be optimised simultaneously.

  14. ADAPTIVELY IMPROVING LONG DISTANCE NETWORK TRANSFERS WITH LOGISTICS

    Energy Technology Data Exchange (ETDEWEB)

    LaBissoniere, D.; Roche, K.

    2007-01-01

    Long distance data movement is an essential activity of modern computing. However, the congestion control mechanisms in the Internet’s Transmission Control Protocol (TCP) severely limit the bandwidth achieved by long distance data transfers. The throughput of such transfers can be improved by applying the logistical technique of breaking a single long distance transfer into multiple shorter transfers. This technique can result in signifi cantly improved throughput while still respecting the shared nature of the Internet by not attempting to circumvent the TCP congestion controls. This technique has been incorporated into an algorithm which attempts to dynamically schedule transfers for optimal throughput. The algorithm couples graph techniques with real-time latency and bandwidth measurements to discover the best path and adaptively respond to network dynamics. The algorithm shows improvements in speed and fl exibility over standard data transfer methods such as FTP. Specifi c transfers tests performed between Oak Ridge National Laboratory and a destination in Sunnyvale, CA show throughput increases by a factor of two.

  15. Improved Detection of Time Windows of Brain Responses in Fmri Using Modified Temporal Clustering Analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Temporal clustering analysis (TCA) has been proposed recently as a method to detect time windows of brain responses in functional MRI (fMRI) studies when the timing and location of the activation are completely unknown. Modifications to the TCA technique are introduced in this report to further improve the sensitivity in detecting brain activation.

  16. Adaptive data analysis for characterizing the temporal variability of the solar resource

    OpenAIRE

    Bengulescu, Marc; Blanc, Philippe; Wald, Lucien

    2016-01-01

    International audience One of the key challenges associated with the large-scale penetration of solar power is the inherent spatio-temporal variability of the solar radiation impinging on the surface. Particular methods are currently employed to measure, estimate or forecast the extent and availability of the solar resource depending on the effective spatial and temporal scales of interest, such as numerical weather prediction models, satellite-based estimates, sky-imagers or in-situ groun...

  17. An Enhanced Framework for Improving Spatio-Temporal Queries for Global Positioning Systems

    Directory of Open Access Journals (Sweden)

    Jalal Atoum

    2013-03-01

    Full Text Available To efficiently process continuous spatio-temporal queries, we need to efficiently and effectively handle large number of moving objects and continuous updates on these queries. In this paper, we propose a framework that employs a new indexing algorithm that is built on top of SQL Server 2008 and avoid the overhead related to R-Tree indexing. To answer range queries, we utilize dynamic materialized view concept to efficiently handle update queries. We propose an adaptive safe region to reduce communication costs between the client and the server and to minimize position update load. Caching of results was utilized to enhance the overall performance of the framework. To handle concurrent spatio-temporal queries, we utilize publish/subscribe paradigm to group similar queries and efficiently process these requests. Experiments show that the overall proposed framework performance was able to outperform R-Tree index and produce promising and satisfactory results

  18. Improving scalable video adaptation in a knowledge-based framework

    OpenAIRE

    Lopez Hernandez, Fernando; Nur, Gokce; Dogan, Safak; Arachchi, Hemantha; Mrak, M.; Martinez, Jose Maria; García Santos, Narciso; Kondoz, Ahmet

    2010-01-01

    In a knowledge-based content adaptation framework, video adaptation can be performed in a series of steps, named conversions. The high-level decision phase in such a framework occasionally encounters several feasible parameter values of a specific conversion. This paper proposes to transfer further decisions to a low-level phase that decides which parameters maximise the quality of the adaptation. Particularly when more than one solution are available, an innovative quality measure is used fo...

  19. An Efficient Adaptive Window Size Selection Method for Improving Spectrogram Visualization

    Directory of Open Access Journals (Sweden)

    Shibli Nisar

    2016-01-01

    Full Text Available Short Time Fourier Transform (STFT is an important technique for the time-frequency analysis of a time varying signal. The basic approach behind it involves the application of a Fast Fourier Transform (FFT to a signal multiplied with an appropriate window function with fixed resolution. The selection of an appropriate window size is difficult when no background information about the input signal is known. In this paper, a novel empirical model is proposed that adaptively adjusts the window size for a narrow band-signal using spectrum sensing technique. For wide-band signals, where a fixed time-frequency resolution is undesirable, the approach adapts the constant Q transform (CQT. Unlike the STFT, the CQT provides a varying time-frequency resolution. This results in a high spectral resolution at low frequencies and high temporal resolution at high frequencies. In this paper, a simple but effective switching framework is provided between both STFT and CQT. The proposed method also allows for the dynamic construction of a filter bank according to user-defined parameters. This helps in reducing redundant entries in the filter bank. Results obtained from the proposed method not only improve the spectrogram visualization but also reduce the computation cost and achieves 87.71% of the appropriate window length selection.

  20. Temporal perspective and other psychological factors making it difficult to adapt to requirements of treatment in chronic dialysis patients

    Directory of Open Access Journals (Sweden)

    Zawadzka, Barbara

    2014-10-01

    Full Text Available Aim. The study analyzed the relationship between temporal perspective, selected personal resources, and unhealthy behavior, manifesting in problems with adherence to fluid intake restrictions, in chronic hemodialyzis patients. The authors tried to answer the question whether there is temporal perspective and other psychological factors increasing the risk of non-adaptive behaviors. Methods. Sixty-one patients, aged 23–81 years (M = 59; SD = 13,9 on chronic hemodialysis at the Department of Nephrology University Hospital were qualified to the study. The study group consisted of 30 patients with poorer fluid regimen adherence and 31 controls, who maintained fluid regimen. The patients were qualified on the bases of the average interdialysis weight gains measured nine times during three weeks. The following research tools were used: P. Zimbardo and J. Boyd ZTPI test; P.T. Costa and R.R. McCrae NEO-FFI Inventory; J. Strelau Temperament Inventory, R. Schwarzer GSES; M. F. Scheier; C. S. Carver and M. W. Bridges LOT-R; M. Watson and S. Greer CECS; BJ. Felton, TA. Revenson, GA. Hinrichsen AIS. Results. Difficulties in adapting to the fluid intake restrictions are significantly associated with temporal orientation towards negative aspects of the present and the past. Non-adaptive health behaviors are typical for patients with temperamental lack of balance between agitation and inhibition processes and are characterized by high agreeableness and low conscientiousness. The association between excessive anger control and the risk of non-adherence medical recommendations. Conclusions. Time perception and other personality factors form mechanisms regulating health behaviors in chronically treatment patients.

  1. Improvement of the temporal and spatial contrast of high-brightness laser beams

    Science.gov (United States)

    Szatmári, S.; Dajka, R.; Barna, A.; Gilicze, B.; Földes, I. B.

    2016-07-01

    A novel method is suggested for temporal and spatial cleaning of high-brightness laser pulses, which seems more energy-scalable than that based on crossed polarizers and offers better contrast improvement compared to the plasma mirror technique. The suggested arrangement utilizes nonlinear modulation of the beam in the Fourier-plane leading both to directional and to temporal modulation. By the use of a ‘conjugate’ aperture arrangement before and after the nonlinear spatial selector, intensity dependent transmission is obtained; simultaneous temporal and spatial filtering can be realized both for amplitude and phase modulation. In the case of phase modulation introduced by plasma generation in noble gases the experimental observations are in good agreement with the theory; demonstrating  >103 improvement in the temporal contrast, ~40% throughput, associated with effective spatial filtering. Due to the broad spectral and power durability of the optical arrangement used here, the method is widely applicable for energetic beams even of UV wavelengths, where most of the former techniques have limited throughput.

  2. Advancing of Land Surface Temperature Retrieval Using Extreme Learning Machine and Spatio-Temporal Adaptive Data Fusion Algorithm

    Directory of Open Access Journals (Sweden)

    Yang Bai

    2015-04-01

    Full Text Available As a critical variable to characterize the biophysical processes in ecological environment, and as a key indicator in the surface energy balance, evapotranspiration and urban heat islands, Land Surface Temperature (LST retrieved from Thermal Infra-Red (TIR images at both high temporal and spatial resolution is in urgent need. However, due to the limitations of the existing satellite sensors, there is no earth observation which can obtain TIR at detailed spatial- and temporal-resolution simultaneously. Thus, several attempts of image fusion by blending the TIR data from high temporal resolution sensor with data from high spatial resolution sensor have been studied. This paper presents a novel data fusion method by integrating image fusion and spatio-temporal fusion techniques, for deriving LST datasets at 30 m spatial resolution from daily MODIS image and Landsat ETM+ images. The Landsat ETM+ TIR data were firstly enhanced based on extreme learning machine (ELM algorithm using neural network regression model, from 60 m to 30 m resolution. Then, the MODIS LST and enhanced Landsat ETM+ TIR data were fused by Spatio-temporal Adaptive Data Fusion Algorithm for Temperature mapping (SADFAT in order to derive high resolution synthetic data. The synthetic images were evaluated for both testing and simulated satellite images. The average difference (AD and absolute average difference (AAD are smaller than 1.7 K, where the correlation coefficient (CC and root-mean-square error (RMSE are 0.755 and 1.824, respectively, showing that the proposed method enhances the spatial resolution of the predicted LST images and preserves the spectral information at the same time.

  3. Coherent diffractive imaging of time-evolving samples with improved temporal resolution

    Energy Technology Data Exchange (ETDEWEB)

    Ulvestad, A.; Tripathi, A.; Hruszkewycz, S. O.; Cha, W.; Wild, S. M.; Stephenson, G. B.; Fuoss, P. H.

    2016-05-19

    Bragg coherent x-ray diffractive imaging is a powerful technique for investigating dynamic nanoscale processes in nanoparticles immersed in reactive, realistic environments. Its temporal resolution is limited, however, by the oversampling requirements of three-dimensional phase retrieval. Here, we show that incorporating the entire measurement time series, which is typically a continuous physical process, into phase retrieval allows the oversampling requirement at each time step to be reduced, leading to a subsequent improvement in the temporal resolution by a factor of 2-20 times. The increased time resolution will allow imaging of faster dynamics and of radiation-dose-sensitive samples. This approach, which we call "chrono CDI," may find use in improving the time resolution in other imaging techniques.

  4. Adaptation improves neural coding efficiency despite increasing correlations in variability.

    Science.gov (United States)

    Adibi, Mehdi; McDonald, James S; Clifford, Colin W G; Arabzadeh, Ehsan

    2013-01-30

    Exposure of cortical cells to sustained sensory stimuli results in changes in the neuronal response function. This phenomenon, known as adaptation, is a common feature across sensory modalities. Here, we quantified the functional effect of adaptation on the ensemble activity of cortical neurons in the rat whisker-barrel system. A multishank array of electrodes was used to allow simultaneous sampling of neuronal activity. We characterized the response of neurons to sinusoidal whisker vibrations of varying amplitude in three states of adaptation. The adaptors produced a systematic rightward shift in the neuronal response function. Consistently, mutual information revealed that peak discrimination performance was not aligned to the adaptor but to test amplitudes 3-9 μm higher. Stimulus presentation reduced single neuron trial-to-trial response variability (captured by Fano factor) and correlations in the population response variability (noise correlation). We found that these two types of variability were inversely proportional to the average firing rate regardless of the adaptation state. Adaptation transferred the neuronal operating regime to lower rates with higher Fano factor and noise correlations. Noise correlations were positive and in the direction of signal, and thus detrimental to coding efficiency. Interestingly, across all population sizes, the net effect of adaptation was to increase the total information despite increasing the noise correlation between neurons. PMID:23365247

  5. Towards Adaptive Educational Assessments: Predicting Student Performance using Temporal Stability and Data Analytics in Learning Management Systems

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Gautam [ORNL; Olama, Mohammed M [ORNL; McNair, Wade [ORNL; Sukumar, Sreenivas R [ORNL

    2014-01-01

    Data-driven assessments and adaptive feedback are becoming a cornerstone research in educational data analytics and involve developing methods for exploring the unique types of data that come from the educational context. For example, predicting college student performance is crucial for both the students and educational institutions. It can support timely intervention to prevent students from failing a course, increasing efficacy of advising functions, and improving course completion rate. In this paper, we present our efforts in using data analytics that enable educationists to design novel data-driven assessment and feedback mechanisms. In order to achieve this objective, we investigate temporal stability of students grades and perform predictive analytics on academic data collected from 2009 through 2013 in one of the most commonly used learning management systems, called Moodle. First, we have identified the data features useful for assessments and predicting student outcomes such as students scores in homework assignments, quizzes, exams, in addition to their activities in discussion forums and their total Grade Point Average(GPA) at the same term they enrolled in the course. Second, time series models in both frequency and time domains are applied to characterize the progression as well as overall projections of the grades. In particular, the model analyzed the stability as well as fluctuation of grades among students during the collegiate years (from freshman to senior) and disciplines. Third, Logistic Regression and Neural Network predictive models are used to identify students as early as possible who are in danger of failing the course they are currently enrolled in. These models compute the likelihood of any given student failing (or passing) the current course. The time series analysis indicates that assessments and continuous feedback are critical for freshman and sophomores (even with easy courses) than for seniors, and those assessments may be

  6. Temporal variation in sex allocation in the mealybug Planococcus citri : Adaptation, constraint, or both?

    NARCIS (Netherlands)

    Ross, Laura; Langenhof, Minke B. W.; Pen, Ido; Shuker, David M.

    2012-01-01

    Sex ratio theory has been very successful in predicting under which circumstances parents should bias their investment towards a particular offspring sex. However, most examples of adaptive sex ratio bias come from species with well-defined mating systems and sex determining mechanisms, while in man

  7. Adaptive classification of temporal signals in fixed-weights recurrent neural networks: an existence proof

    CERN Document Server

    Tyukin, Ivan; van Leeuwen, Cees

    2007-01-01

    We address the important theoretical question why a recurrent neural network with fixed weights can adaptively classify time-varied signals in the presence of additive noise and parametric perturbations. We provide a mathematical proof assuming that unknown parameters are allowed to enter the signal nonlinearly and the noise amplitude is sufficiently small.

  8. Improving the evidence for ecosystem-based adaptation

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Hannah

    2011-11-15

    Ecosystem-based approaches to adaptation (EBA) integrate the use of biodiversity and ecosystem services into an overall strategy for helping people adapt to climate change. The body of scientific evidence that indicates how effective they are is in some cases lacking but in other cases is dispersed across a range of related fields, such as natural resource management, disaster risk reduction and agroecology, from which it needs to be synthesised. Without presenting and strengthening this evidence in a consolidated way, EBA cannot secure the policy traction at local, national and international levels that it merits.

  9. Spatial and temporal task characteristics as stress: a test of the dynamic adaptability theory of stress, workload, and performance.

    Science.gov (United States)

    Szalma, James L; Teo, Grace W L

    2012-03-01

    The goal for this study was to test assertions of the dynamic adaptability theory of stress, which proposes two fundamental task dimensions, information rate (temporal properties of a task) and information structure (spatial properties of a task). The theory predicts adaptive stability across stress magnitudes, with progressive and precipitous changes in adaptive response manifesting first as increases in perceived workload and stress and then as performance failure. Information structure was manipulated by varying the number of displays to be monitored (1, 2, 4 or 8 displays). Information rate was manipulated by varying stimulus presentation rate (8, 12, 16, or 20 events/min). A signal detection task was used in which critical signals were pairs of digits that differed by 0 or 1. Performance accuracy declined and workload and stress increased as a function of increased task demand, with a precipitous decline in accuracy at the highest demand levels. However, the form of performance change as well as the pattern of relationships between speed and accuracy and between performance and workload/stress indicates that some aspects of the theory need revision. Implications of the results for the theory and for future research are discussed.

  10. Sentence Syntax and Content in the Human Temporal Lobe: An fMRI Adaptation Study in Auditory and Visual Modalities

    Energy Technology Data Exchange (ETDEWEB)

    Devauchelle, A.D.; Dehaene, S.; Pallier, C. [INSERM, Gif sur Yvette (France); Devauchelle, A.D.; Dehaene, S.; Pallier, C. [CEA, DSV, I2BM, NeuroSpin, F-91191 Gif Sur Yvette (France); Devauchelle, A.D.; Pallier, C. [Univ. Paris 11, Orsay (France); Oppenheim, C. [Univ Paris 05, Ctr Hosp St Anne, Paris (France); Rizzi, L. [Univ Siena, CISCL, I-53100 Siena (Italy); Dehaene, S. [Coll France, F-75231 Paris (France)

    2009-07-01

    Priming effects have been well documented in behavioral psycho-linguistics experiments: The processing of a word or a sentence is typically facilitated when it shares lexico-semantic or syntactic features with a previously encountered stimulus. Here, we used fMRI priming to investigate which brain areas show adaptation to the repetition of a sentence's content or syntax. Participants read or listened to sentences organized in series which could or not share similar syntactic constructions and/or lexico-semantic content. The repetition of lexico-semantic content yielded adaptation in most of the temporal and frontal sentence processing network, both in the visual and the auditory modalities, even when the same lexico-semantic content was expressed using variable syntactic constructions. No fMRI adaptation effect was observed when the same syntactic construction was repeated. Yet behavioral priming was observed at both syntactic and semantic levels in a separate experiment where participants detected sentence endings. We discuss a number of possible explanations for the absence of syntactic priming in the fMRI experiments, including the possibility that the conglomerate of syntactic properties defining 'a construction' is not an actual object assembled during parsing. (authors)

  11. Improved Gaussian Mixture Models for Adaptive Foreground Segmentation

    DEFF Research Database (Denmark)

    Katsarakis, Nikolaos; Pnevmatikakis, Aristodemos; Tan, Zheng-Hua;

    2016-01-01

    elements to the baseline algorithm: The learning rate can change across space and time, while the Gaussian distributions can be merged together if they become similar due to their adaptation process. We quantify the importance of our enhancements and the effect of parameter tuning using an annotated...

  12. Adaptation of Drosophila to a novel laboratory environment reveals temporally heterogeneous trajectories of selected alleles.

    Science.gov (United States)

    Orozco-terWengel, Pablo; Kapun, Martin; Nolte, Viola; Kofler, Robert; Flatt, Thomas; Schlötterer, Christian

    2012-10-01

    The genomic basis of adaptation to novel environments is a fundamental problem in evolutionary biology that has gained additional importance in the light of the recent global change discussion. Here, we combined laboratory natural selection (experimental evolution) in Drosophila melanogaster with genome-wide next generation sequencing of DNA pools (Pool-Seq) to identify alleles that are favourable in a novel laboratory environment and traced their trajectories during the adaptive process. Already after 15 generations, we identified a pronounced genomic response to selection, with almost 5000 single nucleotide polymorphisms (SNP; genome-wide false discovery rates heterogeneous, with the alleles falling into two distinct classes: (i) alleles that continuously rise in frequency; and (ii) alleles that at first increase rapidly but whose frequencies then reach a plateau. Our data thus suggest that the genomic response to selection can involve a large number of selected SNPs that show unexpectedly complex evolutionary trajectories, possibly due to nonadditive effects.

  13. Iterative 4D cardiac micro-CT image reconstruction using an adaptive spatio-temporal sparsity prior

    Science.gov (United States)

    Ritschl, Ludwig; Sawall, Stefan; Knaup, Michael; Hess, Andreas; Kachelrieß, Marc

    2012-03-01

    Temporal-correlated image reconstruction, also known as 4D CT image reconstruction, is a big challenge in computed tomography. The reasons for incorporating the temporal domain into the reconstruction are motions of the scanned object, which would otherwise lead to motion artifacts. The standard method for 4D CT image reconstruction is extracting single motion phases and reconstructing them separately. These reconstructions can suffer from undersampling artifacts due to the low number of used projections in each phase. There are different iterative methods which try to incorporate some a priori knowledge to compensate for these artifacts. In this paper we want to follow this strategy. The cost function we use is a higher dimensional cost function which accounts for the sparseness of the measured signal in the spatial and temporal directions. This leads to the definition of a higher dimensional total variation. The method is validated using in vivo cardiac micro-CT mouse data. Additionally, we compare the results to phase-correlated reconstructions using the FDK algorithm and a total variation constrained reconstruction, where the total variation term is only defined in the spatial domain. The reconstructed datasets show strong improvements in terms of artifact reduction and low-contrast resolution compared to other methods. Thereby the temporal resolution of the reconstructed signal is not affected.

  14. A phantom study on temporal and subband Minimum Variance adaptive beamforming

    DEFF Research Database (Denmark)

    Diamantis, Konstantinos; Voxen, Iben Holfort; Greenaway, Alan H.;

    2014-01-01

    from conventional Delay-and-Sum (DAS) beamformer. FWHM measured at the depth of 46.6 mm, is 0.02 mm (0.09λ) for both adaptive methods while the corresponding values for Hanning and Boxcar weights are 0.64 and 0.44 mm respectively. Between the MV beamformers a -2 dB difference in PSL is noticed in favor...

  15. SafeBox: adaptable spatio-temporal generalization for location privacy protection

    Directory of Open Access Journals (Sweden)

    Sergio Mascetti

    2014-08-01

    Full Text Available Spatial and temporal generalization emerged in the literature as a common approach to preserve location privacy. However, existing solutions have two main shortcomings. First, spatiotemporal generalization can be used with different objectives: for example, to guarantee anonymity or to decrease the sensitivity of the location information. Hence, the strategy used to compute the generalization can follow different semantics often depending on the privacy threat, while most of the existing solutions are specifically designed for a single semantics. Second, existing techniques prevent the so-called inversion attack by adopting a top-down strategy that needs to acquire a large amount of information. This may not be feasible when this information is dynamic (e.g., position or properties of objects and needs to be acquired from external services (e.g., Google Maps. In this contribution we present a formal model of the problem that is compatible with most of the semantics proposed so far in the literature, and that supports new semantics as well. Our BottomUp algorithm for spatio-temporal generalization is compatible with the use of online services, it supports generalizations based on arbitrary semantics, and it is safe with respect to the inversion attack. By considering two datasets and two examples of semantics, we experimentally compare BottomUp with a more classical top-down algorithm, showing that BottomUp is efficient and guarantees better performance in terms of the average size (space and time of the generalized regions.

  16. Improved Based on "Self-Adaptive Turning Rate" Model Algorithm

    Directory of Open Access Journals (Sweden)

    Xiuling He

    2013-06-01

    Full Text Available For tracking the object with tracking nonlinear, high maneuvering target,traditional interactive multiple model self-adaptive filter algorithm was usually adopted.The turning rate estimate was very important. However,the performance of turning rate algorithm was not so satisfactory in the  model.Thus,a new the average value turning rate algorithm based on self-adaptive turning model was proposed.Aiming at additional device for turning rate estimation turning model, the parameters α and β were introduced to adjust the roughness of turning rate.Aiming at target constant turning movement and orthogonal turning rate unequal, estimates, turning rate was used the average value model to reduce the noise and error influence. Simulation results showed that the proposed algorithm was more suitable for the objects with Nonlinear, high maneuvering target tracking and could remarkably reduce the sample,and thus achieve much better tracking performance.

  17. Improved Multiple Descriptions Sinusoidal Coder Adaptive to Packet Loss Rate

    Institute of Scientific and Technical Information of China (English)

    LANG Yue; WANG Jing; ZHAO Sheng-hui; KUANG Jing-ming

    2008-01-01

    To make the multiple descriptions codec adaptive to the packet loss rate, which can minimize the final distortion, a novel adaptive multiple descriptions sinusoidal coder (AMDSC) is proposed, which is based on a sinusoidal model and a noise model. Firstly, the sinusoidal parameters are extracted in the sinusoidal model, and ordered in a decrease manner. Odd indexed and even indexed parameters are divided into two descriptions. Secondly, the output vector from the noise model is split vector quantized. And the two sub-vectors are placed into two descriptions too. Finally, the number of the extracted parameters and the redundancy between the two descriptions are adjusted according to the packet loss rate of the network. Analytical and experimental results show that the proposed AMDSC outperforms existing MD speech coders by taking network loss characteristics into account. Therefore, it is very suitable for unreliable channels.

  18. SRAM lifetime improvement by using adaptive proactive reconfiguration

    OpenAIRE

    Pouyan, Peyman; Amat Bertran, Esteve; Rubio Sola, Jose Antonio

    2012-01-01

    Modern generations of CMOS technology nodes are facing critical causes of hardware reliability failures, which were not significant in the past. Such vulnerabilities make it essential to investigate new robust design strategies at the Nanoscale circuit system level. In this paper we have introduced an adaptive proactive reconfiguration technique that considers the inherent process variability (variability-aware) and BTI aging, and effectively enlarges the SRAM lifetime. Peer Reviewed

  19. Improvement ocean wave spectra estimation using the temporal structure of wave systems

    OpenAIRE

    Kpogo-Nuwoklo, K.A.; Ailliot, P; Olagnon, M.; Guédé, Z.; Arnault, Sabine

    2015-01-01

    Sea states are usually the combination of several time-evolving wave systems whereas the classical spectral estimation methods assume stationarity. A method that adapts to the dynamical evolution of the spectral components is proposed to improve both omnidirectional and directional sea wave spectral estimations. In this method, periodograms are computed for each sea state as in the conventional methods, and rather than only smoothing individual periodograms, the overall time-history of period...

  20. Adaptation of Drosophila to a novel laboratory environment reveals temporally heterogeneous trajectories of selected alleles

    Science.gov (United States)

    Orozco-terWengel, Pablo; Kapun, Martin; Nolte, Viola; Kofler, Robert; Flatt, Thomas; Schlötterer, Christian

    2012-01-01

    The genomic basis of adaptation to novel environments is a fundamental problem in evolutionary biology that has gained additional importance in the light of the recent global change discussion. Here, we combined laboratory natural selection (experimental evolution) in Drosophila melanogaster with genome-wide next generation sequencing of DNA pools (Pool-Seq) to identify alleles that are favourable in a novel laboratory environment and traced their trajectories during the adaptive process. Already after 15 generations, we identified a pronounced genomic response to selection, with almost 5000 single nucleotide polymorphisms (SNP; genome-wide false discovery rates < 0.005%) deviating from neutral expectation. Importantly, the evolutionary trajectories of the selected alleles were heterogeneous, with the alleles falling into two distinct classes: (i) alleles that continuously rise in frequency; and (ii) alleles that at first increase rapidly but whose frequencies then reach a plateau. Our data thus suggest that the genomic response to selection can involve a large number of selected SNPs that show unexpectedly complex evolutionary trajectories, possibly due to nonadditive effects. PMID:22726122

  1. Development and applications of coherent imaging with improved temporal and spatial resolution

    International Nuclear Information System (INIS)

    This work has 2 purposes: the improvement of both temporal and spatial resolution of X-ray tomography. The first part is devoted to the technical aspects of the tomographic technique, particularly at the ESRF (European Synchrotron Radiation Facility) beamline ID19, and the application of the new acquisition scheme to the imaging of liquid foams. We have improved the temporal resolution and field of view of the setup, which allowed to obtain for the first time experimental data with good statistics on three dimensional liquid foams. In the second part of the thesis we have described the Kirkpatrick-Baez focusing system and its first applications. In terms of stability and image quality the developments presented in this part of the thesis provide valuable evidence for the feasibility of phase contrast tomography in magnifying geometry. Since the ultimate goal of this research is to improve the spatial resolution in tomography for applications, four different contributions are important for the characterization of the imaging system: 1) the thermal stability and mechanical imperfections, 2) effects of distortion induced by mirror imperfections, 3) effects of refraction on sample borders, and 4) phase propagation effects with the influence of the magnification. Each of these factors has been studied

  2. Non-iterative adaptive time-stepping scheme with temporal truncation error control for simulating variable-density flow

    Science.gov (United States)

    Hirthe, Eugenia M.; Graf, Thomas

    2012-12-01

    The automatic non-iterative second-order time-stepping scheme based on the temporal truncation error proposed by Kavetski et al. [Kavetski D, Binning P, Sloan SW. Non-iterative time-stepping schemes with adaptive truncation error control for the solution of Richards equation. Water Resour Res 2002;38(10):1211, http://dx.doi.org/10.1029/2001WR000720.] is implemented into the code of the HydroGeoSphere model. This time-stepping scheme is applied for the first time to the low-Rayleigh-number thermal Elder problem of free convection in porous media [van Reeuwijk M, Mathias SA, Simmons CT, Ward JD. Insights from a pseudospectral approach to the Elder problem. Water Resour Res 2009;45:W04416, http://dx.doi.org/10.1029/2008WR007421.], and to the solutal [Shikaze SG, Sudicky EA, Schwartz FW. Density-dependent solute transport in discretely-fractured geological media: is prediction possible? J Contam Hydrol 1998;34:273-91] problem of free convection in fractured-porous media. Numerical simulations demonstrate that the proposed scheme efficiently limits the temporal truncation error to a user-defined tolerance by controlling the time-step size. The non-iterative second-order time-stepping scheme can be applied to (i) thermal and solutal variable-density flow problems, (ii) linear and non-linear density functions, and (iii) problems including porous and fractured-porous media.

  3. Spatial and temporal variation of an ice-adapted predator's feeding ecology in a changing Arctic marine ecosystem.

    Science.gov (United States)

    Yurkowski, David J; Ferguson, Steven H; Semeniuk, Christina A D; Brown, Tanya M; Muir, Derek C G; Fisk, Aaron T

    2016-03-01

    Spatial and temporal variation can confound interpretations of relationships within and between species in terms of diet composition, niche size, and trophic position (TP). The cause of dietary variation within species is commonly an ontogenetic niche shift, which is a key dynamic influencing community structure. We quantified spatial and temporal variations in ringed seal (Pusa hispida) diet, niche size, and TP during ontogeny across the Arctic-a rapidly changing ecosystem. Stable carbon and nitrogen isotope analysis was performed on 558 liver and 630 muscle samples from ringed seals and on likely prey species from five locations ranging from the High to the Low Arctic. A modest ontogenetic diet shift occurred, with adult ringed seals consuming more forage fish (approximately 80 versus 60 %) and having a higher TP than subadults, which generally decreased with latitude. However, the degree of shift varied spatially, with adults in the High Arctic presenting a more restricted niche size and consuming more Arctic cod (Boreogadus saida) than subadults (87 versus 44 %) and adults at the lowest latitude (29 %). The TPs of adult and subadult ringed seals generally decreased with latitude (4.7-3.3), which was mainly driven by greater complexity in trophic structure within the zooplankton communities. Adult isotopic niche size increased over time, likely due to the recent circumpolar increases in subarctic forage fish distribution and abundance. Given the spatial and temporal variability in ringed seal foraging ecology, ringed seals exhibit dietary plasticity as a species, suggesting adaptability in terms of their diet to climate change. PMID:26210748

  4. SOAR Adaptive Module (SAM): seeing improvement with a UV laser

    CERN Document Server

    Tokovinin, Andrei; Tighe, Roberto; Schurter, Patricio; Martinez, Manuel; Thomas, Sandrine; van der Bliek, Nicole

    2016-01-01

    The adaptive module of the 4.1-m SOAR telescope, SAM, corrects ground-layer turbulence using a UV laser guide star. It has been commissioned in 2013 and it is in regular science operation since 2014. SAM works with the CCD imager covering a 3' field or with the speckle camera. It operates routinely and stably, delivering resolution in the I band equal to the free-atmosphere seeing. This paper describes the SAM system as a whole, providing essential reference for its users and technical information of interest to instrumentalists. Operation of the instrument, its performance, and science projects done with SAM so far are reviewed.

  5. Adaptive optics for improved retinal surgery and diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Humayun, M S; Sadda, S R; Thompson, C A; Olivier, S S; Kartz, M W

    2000-08-21

    It is now possible to field a compact adaptive optics (AO) system on a surgical microscope for use in retinal diagnostics and surgery. Recent developments in integrated circuit technology and optical photonics have led to the capability of building an AO system that is compact and significantly less expensive than traditional AO systems. It is foreseen that such an AO system can be integrated into a surgical microscope while maintaining a package size of a lunchbox. A prototype device can be developed in a manner that lends itself well to large-scale manufacturing.

  6. Improved adaptive-threshold burst assembly in optical burst switching networks

    Institute of Scientific and Technical Information of China (English)

    Jiuru Yang; Gang Wang; Shilou Jia

    2007-01-01

    An improved adaptive-threshold burst assembly algorithm is proposed to alleviate the limitation of conventional assembly schemes on data loss and delay. The algorithm will adjust the values of assembly factors according to variant traffic regions. And the simulation results show that, by using the adaptive-factor adaptive assembly scheme, the performance of networks is extensively enhanced in terms of burst loss probability and average queuing delay.

  7. Simultaneous expression of regulatory genes associated with specific drought-adaptive traits improves drought adaptation in peanut.

    Science.gov (United States)

    Ramu, Vemanna S; Swetha, Thavarekere N; Sheela, Shekarappa H; Babitha, Chandrashekar K; Rohini, Sreevathsa; Reddy, Malireddy K; Tuteja, Narendra; Reddy, Chandrashekar P; Prasad, Trichi Ganesh; Udayakumar, Makarla

    2016-03-01

    Adaptation of crops to drought-prone rain-fed conditions can be achieved by improving plant traits such as efficient water mining (by superior root characters) and cellular-level tolerance mechanisms. Pyramiding these drought-adaptive traits by simultaneous expression of genes regulating drought-adaptive mechanisms has phenomenal relevance in improving stress tolerance. In this study, we provide evidence that peanut transgenic plants expressing Alfalfa zinc finger 1 (Alfin1), a root growth-associated transcription factor gene, Pennisetum glaucum heat-shock factor (PgHSF4) and Pea DNA helicase (PDH45) involved in protein turnover and protection showed improved tolerance, higher growth and productivity under drought stress conditions. Stable integration of all the transgenes was noticed in transgenic lines. The transgenic lines showed higher root growth, cooler crop canopy air temperature difference (less CCATD) and higher relative water content (RWC) under drought stress. Low proline levels in transgenic lines substantiate the maintenance of higher water status. The survival and recovery of transgenic lines was significantly higher under gradual moisture stress conditions with higher biomass. Transgenic lines also showed significant tolerance to ethrel-induced senescence and methyl viologen-induced oxidative stress. Several stress-responsive genes such as heat-shock proteins (HSPs), RING box protein-1 (RBX1), Aldose reductase, late embryogenesis abundant-5 (LEA5) and proline-rich protein-2 (PRP2), a gene involved in root growth, showed enhanced expression under stress in transgenic lines. Thus, the simultaneous expression of regulatory genes contributing for drought-adaptive traits can improve crop adaptation and productivity under water-limited conditions. PMID:26383697

  8. An Improved Adaptive Deconvolution Algorithm for Single Image Deblurring

    Directory of Open Access Journals (Sweden)

    Hsin-Che Tsai

    2014-01-01

    Full Text Available One of the most common defects in digital photography is motion blur caused by camera shake. Shift-invariant motion blur can be modeled as a convolution of the true latent image and a point spread function (PSF with additive noise. The goal of image deconvolution is to reconstruct a latent image from a degraded image. However, ringing is inevitable artifacts arising in the deconvolution stage. To suppress undesirable artifacts, regularization based methods have been proposed using natural image priors to overcome the ill-posedness of deconvolution problem. When the estimated PSF is erroneous to some extent or the PSF size is large, conventional regularization to reduce ringing would lead to loss of image details. This paper focuses on the nonblind deconvolution by adaptive regularization which preserves image details, while suppressing ringing artifacts. The way is to control the regularization weight adaptively according to the image local characteristics. We adopt elaborated reference maps that indicate the edge strength so that textured and smooth regions can be distinguished. Then we impose an appropriate constraint on the optimization process. The experiments’ results on both synthesized and real images show that our method can restore latent image with much fewer ringing and favors the sharp edges.

  9. Improving personality facet scores with multidimensional computer adaptive testing

    DEFF Research Database (Denmark)

    Makransky, Guido; Mortensen, Erik Lykke; Glas, Cees A W

    2013-01-01

    Narrowly defined personality facet scores are commonly reported and used for making decisions in clinical and organizational settings. Although these facets are typically related, scoring is usually carried out for a single facet at a time. This method can be ineffective and time consuming when...... personality tests contain many highly correlated facets. This article investigates the possibility of increasing the precision of the NEO PI-R facet scores by scoring items with multidimensional item response theory and by efficiently administering and scoring items with multidimensional computer adaptive...... testing (MCAT). The increase in the precision of personality facet scores is obtained from exploiting the correlations between the facets. Results indicate that the NEO PI-R could be substantially shorter without attenuating precision when the MCAT methodology is used. Furthermore, the study shows...

  10. Improved adaptive fuzzy control for MIMO nonlinear time-delay systems

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper presents an improved observer-based indirect adaptive fuzzy control scheme for multiinput-multioutput (MIMO) nonlinear time-delay systems.The control scheme synthesizes adaptive fuzzy control with adaptive fuzzy identification.An observer is designed to observe the system state,and an identifier is developed to identify the unknown parts of the system.The update laws for parameters utilize two types of errors in the adaptive time-delay fuzzy logic systems,the observation error and the identificat...

  11. Further improvement of temporal resolution of seismic data by autoregressive (AR) spectral extrapolation

    Science.gov (United States)

    Karslı, Hakan

    2006-08-01

    Seismic data have still no enough temporal resolution because of band-limited nature of available data even if it is deconvolved. However, lower and higher frequency information belonging to seismic data is missing and it is not directly recovered from seismic data. In this paper, a method originally applied by Honarvar et al. [Honarvar, F., Sheikhzadeh, H., Moles, M., Sinclair, A.N., 2004. Improving the time-resolution and signal-noise ratio of ultrasonic NDE signals. Ultrasonics 41, 755-763.] which is the combination of the most widely used Wiener deconvolution and AR spectral extrapolation in frequency domain is briefly reviewed and is applied to seismic data to improve temporal resolution further. The missing frequency information is optimally recovered by forward and backward extrapolation based on the selection of a high signal-noise ratio (SNR) of signal spectrum deconvolved in signal processing technique. The combination of the two methods is firstly tested on a variety of synthetic examples and then applied to a stacked real trace. The selection of necessary parameters in Wiener filtering and in extrapolation are discussed in detail. It is used an optimum frequency windows between 3 and 10 dB drops by comparing results from these drops, while frequency windows are used as standard between 2.8 and 3.2 dB drops in study of Honarvar et al. [Honarvar, F., Sheikhzadeh, H., Moles, M., Sinclair, A.N., 2004. Improving the time-resolution and signal-noise ratio of ultrasonic NDE signals. Ultrasonics 41, 755-763.]. The results obtained show that the application of the purposed signal processing technique considerably improves temporal resolution of seismic data when compared with the original seismic data. Furthermore, AR based spectral extrapolated data can be almost considered as reflectivity sequence of layered medium. Consequently, the combination of Wiener deconvolution and AR spectral extrapolation can reveal some details of seismic data that cannot be

  12. How Stride Adaptation in Pedestrian Models Improves Navigation

    CERN Document Server

    von Sivers, Isabella

    2014-01-01

    Pedestrians adjust both speed and stride length when they navigate difficult situations such as tight corners or dense crowds. They do this with foresight reacting instantly when they encounter the difficulty. This has an impact on the movement of the whole crowd especially at bottlenecks where slower movement and smaller steps can be observed. State-of-the-art pedestrian motion models automatically reduce speed in dense crowds simply because there is no space where the virtual pedestrians could advance. The stride length, however, is rarely considered, which leads to artifacts. We reformulate the problem of correct stride adaptation as an optimization problem on a disk around the pedestrian. He or she seeks the position that is most attractive in a sense of balanced goals between the search for targets, the need of space of individual pedestrians and the need to keep a distance from obstacles. The result is a fully automatic adjustment that simplifies calibration, and gives visually natural results and an ex...

  13. Improved two-photon imaging of living neurons in brain tissue through temporal gating.

    Science.gov (United States)

    Gautam, Vini; Drury, Jack; Choy, Julian M C; Stricker, Christian; Bachor, Hans-A; Daria, Vincent R

    2015-10-01

    We optimize two-photon imaging of living neurons in brain tissue by temporally gating an incident laser to reduce the photon flux while optimizing the maximum fluorescence signal from the acquired images. Temporal gating produces a bunch of ~10 femtosecond pulses and the fluorescence signal is improved by increasing the bunch-pulse energy. Gating is achieved using an acousto-optic modulator with a variable gating frequency determined as integral multiples of the imaging sampling frequency. We hypothesize that reducing the photon flux minimizes the photo-damage to the cells. Our results, however, show that despite producing a high fluorescence signal, cell viability is compromised when the gating and sampling frequencies are equal (or effectively one bunch-pulse per pixel). We found an optimum gating frequency range that maintains the viability of the cells while preserving a pre-set fluorescence signal of the acquired two-photon images. The neurons are imaged while under whole-cell patch, and the cell viability is monitored as a change in the membrane's input resistance. PMID:26504651

  14. Improving risk-stratification of Diabetes complications using temporal data mining.

    Science.gov (United States)

    Sacchi, Lucia; Dagliati, Arianna; Segagni, Daniele; Leporati, Paola; Chiovato, Luca; Bellazzi, Riccardo

    2015-08-01

    To understand which factor trigger worsened disease control is a crucial step in Type 2 Diabetes (T2D) patient management. The MOSAIC project, funded by the European Commission under the FP7 program, has been designed to integrate heterogeneous data sources and provide decision support in chronic T2D management through patients' continuous stratification. In this work we show how temporal data mining can be fruitfully exploited to improve risk stratification. In particular, we exploit administrative data on drug purchases to divide patients in meaningful groups. The detection of drug consumption patterns allows stratifying the population on the basis of subjects' purchasing attitude. Merging these findings with clinical values indicates the relevance of the applied methods while showing significant differences in the identified groups. This extensive approach emphasized the exploitation of administrative data to identify patterns able to explain clinical conditions. PMID:26736710

  15. Adaptation AC to Improve Wireless Access Network Dependability

    Directory of Open Access Journals (Sweden)

    Olfa BEN AHMED

    2012-01-01

    Full Text Available According to estimation of increasing mobile application‘s consumers. We are interested in Long TermEvaluation (LTE network. LTE dependability depends on availability and reliability of his evolved NodesBases stations (eNB. One eNB is available when it is able yet to admit a new media and to supportconnection. And it is reliable when it is able to support handover connection. However we consider adependable telecommunication service when the available and reliable system can provide an acceptablequality of service (QoS. There are works that given a higher QoS with lower dependability (availabilityand reliability and works that given higher dependability with lowest QoS. We propose a new AdmissionControl scheme using preemption bandwidth from already connected application. Our preemptionproceeds in a relative utility. Results of this work give improvement of dependability with acceptable QoS.

  16. Adaptive noise estimation and suppression for improving microseismic event detection

    Science.gov (United States)

    Mousavi, S. Mostafa; Langston, Charles A.

    2016-09-01

    Microseismic data recorded by surface arrays are often strongly contaminated by unwanted noise. This background noise makes the detection of small magnitude events difficult. A noise level estimation and noise reduction algorithm is presented for microseismic data analysis based upon minimally controlled recursive averaging and neighborhood shrinkage estimators. The method might not be compared with more sophisticated and computationally expensive denoising algorithm in terms of preserving detailed features of seismic signal. However, it is fast and data-driven and can be applied in real-time processing of continuous data for event detection purposes. Results from application of this algorithm to synthetic and real seismic data show that it holds a great promise for improving microseismic event detection.

  17. Improve Problem Solving Skills through Adapting Programming Tools

    Science.gov (United States)

    Shaykhian, Linda H.; Shaykhian, Gholam Ali

    2007-01-01

    There are numerous ways for engineers and students to become better problem-solvers. The use of command line and visual programming tools can help to model a problem and formulate a solution through visualization. The analysis of problem attributes and constraints provide insight into the scope and complexity of the problem. The visualization aspect of the problem-solving approach tends to make students and engineers more systematic in their thought process and help them catch errors before proceeding too far in the wrong direction. The problem-solver identifies and defines important terms, variables, rules, and procedures required for solving a problem. Every step required to construct the problem solution can be defined in program commands that produce intermediate output. This paper advocates improved problem solving skills through using a programming tool. MatLab created by MathWorks, is an interactive numerical computing environment and programming language. It is a matrix-based system that easily lends itself to matrix manipulation, and plotting of functions and data. MatLab can be used as an interactive command line or a sequence of commands that can be saved in a file as a script or named functions. Prior programming experience is not required to use MatLab commands. The GNU Octave, part of the GNU project, a free computer program for performing numerical computations, is comparable to MatLab. MatLab visual and command programming are presented here.

  18. A self-adaptive step Cuckoo search algorithm based on dimension by dimension improvement

    OpenAIRE

    Ren, Lu; Li, Haiyang; He, Xingshi

    2015-01-01

    The choice of step length plays an important role in convergence speed and precision of Cuckoo search algorithm. In the paper, a self-adaptive step Cuckoo search algorithm based on dimensional improvement is provided. First, since the step in the original self-adaptive step Cuckoo search algorithm is not updated when the current position of the nest is in the optimal position, simple modification of the step is made for the update. Second, evaluation strategy based on dimension by dimension u...

  19. Utilizing temporal variations in chemotherapeutic response to improve breast cancer treatment efficacy

    Directory of Open Access Journals (Sweden)

    Daniel J. McGrail

    2015-09-01

    Full Text Available Though survival rates for women with stage I breast cancer have radically improved, treatment options remain poor for the 40% of women diagnosed with later-stage disease. For these patients, improved chemotherapeutic treatment strategies are critical to eradicate any disseminated tumor cells. Despite many promising new drugs in vitro, most ultimately fail in the clinic. One aspect often lost during testing is in vivo circulation half-lives rarely exceed 24 hours, whereas in vitro studies involve drug exposure for 2-3 days. Here, we show how mimicking these exposure times alters efficacy. Next, using this model we show how drug response is highly time-dependent by extending analysis of cell viability out to two weeks. Variations in response both with feeding and time were dependent on drug mechanism of action. Finally, we show that by implementing this temporal knowledge of drug effects to optimize scheduling of drug administration we are able to regain chemosensitivity in a Carboplatin-resistant cell line.

  20. C-arm cone beam CT perfusion imaging using the SMART-RECON algorithm to improve temporal sampling density and temporal resolution

    Science.gov (United States)

    Li, Yinsheng; Niu, Kai; Li, Ke; Schafer, Sebastian; Royalty, Kevin; Strother, Charles; Chen, Guang-Hong

    2016-03-01

    In this work, a newly developed reconstruction algorithm, Synchronized MultiArtifact Reduction with Tomographic RECONstruction (SMART-RECON), was applied to C-arm cone beam CT perfusion (CBCTP) imaging. This algorithm contains a special rank regularizer, designed to reduce limited-view artifacts associated with super- short scan reconstructions. As a result, high temporal sampling and temporal resolution image reconstructions were achieved using an interventional C-arm x-ray system. The algorithm was evaluated in terms of the fidelity of the dynamic contrast update curves and the accuracy of perfusion parameters through numerical simulation studies. Results shows that, not only were the dynamic curves accurately recovered (relative root mean square error ∈ [3%, 5%] compared with [13%, 22%] for FBP), but also the noise in the final perfusion maps was dramatically reduced. Compared with filtered backprojection, SMART-RECON generated CBCTP maps with much improved capability in differentiating lesions with perfusion deficits from the surrounding healthy brain tissues.

  1. An Improved STARFM with Help of an Unmixing-Based Method to Generate High Spatial and Temporal Resolution Remote Sensing Data in Complex Heterogeneous Regions.

    Science.gov (United States)

    Xie, Dengfeng; Zhang, Jinshui; Zhu, Xiufang; Pan, Yaozhong; Liu, Hongli; Yuan, Zhoumiqi; Yun, Ya

    2016-01-01

    Remote sensing technology plays an important role in monitoring rapid changes of the Earth's surface. However, sensors that can simultaneously provide satellite images with both high temporal and spatial resolution haven't been designed yet. This paper proposes an improved spatial and temporal adaptive reflectance fusion model (STARFM) with the help of an Unmixing-based method (USTARFM) to generate the high spatial and temporal data needed for the study of heterogeneous areas. The results showed that the USTARFM had higher accuracy than STARFM methods in two aspects of analysis: individual bands and of heterogeneity analysis. Taking the predicted NIR band as an example, the correlation coefficients (r) for the USTARFM, STARFM and unmixing methods were 0.96, 0.95, 0.90, respectively (p-value < 0.001); Root Mean Square Error (RMSE) values were 0.0245, 0.0300, 0.0401, respectively; and ERGAS values were 0.5416, 0.6507, 0.8737, respectively. The USTARM showed consistently higher performance than STARM when the degree of heterogeneity ranged from 2 to 10, highlighting that the use of this method provides the capacity to solve the data fusion problems faced when using STARFM. Additionally, the USTARFM method could help researchers achieve better performance than STARFM at a smaller window size from its heterogeneous land surface quantitative representation.

  2. AN IMPROVED SPARSITY ADAPTIVE MATCHING PURSUIT ALGORITHM FOR COMPRESSIVE SENSING BASED ON REGULARIZED BACKTRACKING

    Institute of Scientific and Technical Information of China (English)

    Zhao Ruizhen; Ren Xiaoxin; Han Xuelian; Hu Shaohai

    2012-01-01

    Sparsity Adaptive Matching Pursuit (SAMP) algorithm is a widely used reconstruction algorithm for compressive sensing in the case that the sparsity is unknown.In order to match the sparsity more accurately,we presented an improved SAMP algorithm based on Regularized Backtracking (SAMP-RB).By adapting a regularized backtracking step to SAMP algorithm in each iteration stage,the proposed algorithm can flexibly remove the inappropriate atoms.The experimental results show that SAMP-RB reconstruction algorithm greatly improves SAMP algorithm both in reconstruction quality and computational time.It has better reconstruction efficiency than most of the available matching pursuit algorithms.

  3. Research on Public Traffic Vehicles Dispatch Based on Improved Adaptive Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>Bus dispatching has been studied,and also the bus dispatching model is set up.Then,Genetic Algorithm is adaptively improved in order to avoid premature problem and the slow convergence,and then the keeping optimal strategy is used to the Genetic Algorithm,so formed the Improved Adaptive Genetic Algorithm,namely IAGA. Finally,the IAGA is used to optimizing the bus dispatching model,and the results of the simulation indicate IAGA has the higher efficiency than simple GA and is one effective way to optimizing the bus dispatching.

  4. Leg compliance control of a hexapod robot based on improved adaptive control in different environments

    Institute of Scientific and Technical Information of China (English)

    朱雅光; 金波; 李伟

    2015-01-01

    Considering the compliance control problem of a hexapod robot under different environments, a control strategy based on the improved adaptive control algorithm is proposed. The model of robot structure and impedance control is established. Then, the indirect adaptive control algorithm is derived. Through the analysis of its parameters, it can be noticed that the algorithm does not meet the requirements of the robot compliance control in a complex environment. Therefore, the fuzzy control algorithm is used to adjust the adaptive control parameters. The satisfied system response can be obtained based on the adjustment in real time according to the error between input and output. Comparative experiments and analysis of traditional adaptive control and the improved adaptive control algorithm are presented. It can be verified that not only desired contact force can be reached quickly in different environments, but also smaller contact impact and sliding avoidance are guaranteed, which means that the control strategy has great significance to enhance the adaptability of the hexapod robot.

  5. Delay Estimator and Improved Proportionate Multi-Delay Adaptive Filtering Algorithm

    Directory of Open Access Journals (Sweden)

    E. Verteletskaya

    2012-04-01

    Full Text Available This paper pertains to speech and acoustic signal processing, and particularly to a determination of echo path delay and operation of echo cancellers. To cancel long echoes, the number of weights in a conventional adaptive filter must be large. The length of the adaptive filter will directly affect both the degree of accuracy and the convergence speed of the adaptation process. We present a new adaptive structure which is capable to deal with multiple dispersive echo paths. An adaptive filter according to the present invention includes means for storing an impulse response in a memory, the impulse response being indicative of the characteristics of a transmission line. It also includes a delay estimator for detecting ranges of samples within the impulse response having relatively large distribution of echo energy. These ranges of samples are being indicative of echoes on the transmission line. An adaptive filter has a plurality of weighted taps, each of the weighted taps having an associated tap weight value. A tap allocation/control circuit establishes the tap weight values in response to said detecting means so that only taps within the regions of relatively large distributions of echo energy are turned on. Thus, the convergence speed and the degree of estimation in the adaptation process can be improved.

  6. Improving microbial fitness in the mammalian gut by in vivo temporal functional metagenomics.

    Science.gov (United States)

    Yaung, Stephanie J; Deng, Luxue; Li, Ning; Braff, Jonathan L; Church, George M; Bry, Lynn; Wang, Harris H; Gerber, Georg K

    2015-03-11

    Elucidating functions of commensal microbial genes in the mammalian gut is challenging because many commensals are recalcitrant to laboratory cultivation and genetic manipulation. We present Temporal FUnctional Metagenomics sequencing (TFUMseq), a platform to functionally mine bacterial genomes for genes that contribute to fitness of commensal bacteria in vivo. Our approach uses metagenomic DNA to construct large-scale heterologous expression libraries that are tracked over time in vivo by deep sequencing and computational methods. To demonstrate our approach, we built a TFUMseq plasmid library using the gut commensal Bacteroides thetaiotaomicron (Bt) and introduced Escherichia coli carrying this library into germfree mice. Population dynamics of library clones revealed Bt genes conferring significant fitness advantages in E. coli over time, including carbohydrate utilization genes, with a Bt galactokinase central to early colonization, and subsequent dominance by a Bt glycoside hydrolase enabling sucrose metabolism coupled with co-evolution of the plasmid library and E. coli genome driving increased galactose utilization. Our findings highlight the utility of functional metagenomics for engineering commensal bacteria with improved properties, including expanded colonization capabilities in vivo.

  7. Improving microbial fitness in the mammalian gut by in vivo temporal functional metagenomics.

    Science.gov (United States)

    Yaung, Stephanie J; Deng, Luxue; Li, Ning; Braff, Jonathan L; Church, George M; Bry, Lynn; Wang, Harris H; Gerber, Georg K

    2015-03-01

    Elucidating functions of commensal microbial genes in the mammalian gut is challenging because many commensals are recalcitrant to laboratory cultivation and genetic manipulation. We present Temporal FUnctional Metagenomics sequencing (TFUMseq), a platform to functionally mine bacterial genomes for genes that contribute to fitness of commensal bacteria in vivo. Our approach uses metagenomic DNA to construct large-scale heterologous expression libraries that are tracked over time in vivo by deep sequencing and computational methods. To demonstrate our approach, we built a TFUMseq plasmid library using the gut commensal Bacteroides thetaiotaomicron (Bt) and introduced Escherichia coli carrying this library into germfree mice. Population dynamics of library clones revealed Bt genes conferring significant fitness advantages in E. coli over time, including carbohydrate utilization genes, with a Bt galactokinase central to early colonization, and subsequent dominance by a Bt glycoside hydrolase enabling sucrose metabolism coupled with co-evolution of the plasmid library and E. coli genome driving increased galactose utilization. Our findings highlight the utility of functional metagenomics for engineering commensal bacteria with improved properties, including expanded colonization capabilities in vivo.

  8. Improving Prediction Accuracy for WSN Data Reduction by Applying Multivariate Spatio-Temporal Correlation

    Directory of Open Access Journals (Sweden)

    José Neuman de Souza

    2011-10-01

    Full Text Available This paper proposes a method based on multivariate spatial and temporal correlation to improve prediction accuracy in data reduction for Wireless Sensor Networks (WSN. Prediction of data not sent to the sink node is a technique used to save energy in WSNs by reducing the amount of data traffic. However, it may not be very accurate. Simulations were made involving simple linear regression and multiple linear regression functions to assess the performance of the proposed method. The results show a higher correlation between gathered inputs when compared to time, which is an independent variable widely used for prediction and forecasting. Prediction accuracy is lower when simple linear regression is used, whereas multiple linear regression is the most accurate one. In addition to that, our proposal outperforms some current solutions by about 50% in humidity prediction and 21% in light prediction. To the best of our knowledge, we believe that we are probably the first to address prediction based on multivariate correlation for WSN data reduction.

  9. Temporal modulations of agonist and antagonist muscle activities accompanying improved performance of ballistic movements.

    Science.gov (United States)

    Liang, Nan; Yamashita, Takamasa; Ni, Zhen; Takahashi, Makoto; Murakami, Tsuneji; Yahagi, Susumu; Kasai, Tatsuya

    2008-02-01

    Although many studies have examined performance improvements of ballistic movement through practice, it is still unclear how performance advances while maintaining maximum velocity, and how the accompanying triphasic electromyographic (EMG) activity is modified. The present study focused on the changes in triphasic EMG activity, i.e., the first agonist burst (AG1), the second agonist burst (AG2), and the antagonist burst (ANT), that accompanied decreases in movement time and error. Twelve healthy volunteers performed 100 ballistic wrist flexion movements in ten 10-trial sessions under the instruction to "maintain maximum velocity throughout the experiment and to stop the limb at the target as fast and accurately as possible". Kinematic parameters (position and velocity) and triphasic EMG activities from the agonist (flexor carpi radialis) and antagonist (extensor carpi radialis) muscles were recorded. Comparison of the results obtained from the first and the last 10 trials, revealed that movement time, movement error, and variability of amplitudes reduced with practice, and that maximum velocity and time to maximum velocity remained constant. EMG activities showed that AG1 and AG2 durations were reduced, whereas ANT duration did not change. Additionally, ANT and AG2 latencies were reduced. Integrated EMG of AG1 was significantly reduced as well. Analysis of the alpha angle (an index of the rate of recruitment of the motoneurons) showed that there was no change in either AG1 or AG2. Correlation analysis of alpha angles between these two bursts further revealed that the close relationship of AG1 and AG2 was kept constant through practice. These findings led to the conclusion that performance improvement in ballistic movement is mainly due to the temporal modulations of agonist and antagonist muscle activities when maximum velocity is kept constant. Presumably, a specific strategy is consistently applied during practice.

  10. Improved Simulation of Electrodiffusion in the Node of Ranvier by Mesh Adaptation.

    Science.gov (United States)

    Dione, Ibrahima; Deteix, Jean; Briffard, Thomas; Chamberland, Eric; Doyon, Nicolas

    2016-01-01

    In neural structures with complex geometries, numerical resolution of the Poisson-Nernst-Planck (PNP) equations is necessary to accurately model electrodiffusion. This formalism allows one to describe ionic concentrations and the electric field (even away from the membrane) with arbitrary spatial and temporal resolution which is impossible to achieve with models relying on cable theory. However, solving the PNP equations on complex geometries involves handling intricate numerical difficulties related either to the spatial discretization, temporal discretization or the resolution of the linearized systems, often requiring large computational resources which have limited the use of this approach. In the present paper, we investigate the best ways to use the finite elements method (FEM) to solve the PNP equations on domains with discontinuous properties (such as occur at the membrane-cytoplasm interface). 1) Using a simple 2D geometry to allow comparison with analytical solution, we show that mesh adaptation is a very (if not the most) efficient way to obtain accurate solutions while limiting the computational efforts, 2) We use mesh adaptation in a 3D model of a node of Ranvier to reveal details of the solution which are nearly impossible to resolve with other modelling techniques. For instance, we exhibit a non linear distribution of the electric potential within the membrane due to the non uniform width of the myelin and investigate its impact on the spatial profile of the electric field in the Debye layer. PMID:27548674

  11. Computationally efficient video restoration for Nyquist sampled imaging sensors combining an affine-motion-based temporal Kalman filter and adaptive Wiener filter.

    Science.gov (United States)

    Rucci, Michael; Hardie, Russell C; Barnard, Kenneth J

    2014-05-01

    In this paper, we present a computationally efficient video restoration algorithm to address both blur and noise for a Nyquist sampled imaging system. The proposed method utilizes a temporal Kalman filter followed by a correlation-model based spatial adaptive Wiener filter (AWF). The Kalman filter employs an affine background motion model and novel process-noise variance estimate. We also propose and demonstrate a new multidelay temporal Kalman filter designed to more robustly treat local motion. The AWF is a spatial operation that performs deconvolution and adapts to the spatially varying residual noise left in the Kalman filter stage. In image areas where the temporal Kalman filter is able to provide significant noise reduction, the AWF can be aggressive in its deconvolution. In other areas, where less noise reduction is achieved with the Kalman filter, the AWF balances the deconvolution with spatial noise reduction. In this way, the Kalman filter and AWF work together effectively, but without the computational burden of full joint spatiotemporal processing. We also propose a novel hybrid system that combines a temporal Kalman filter and BM3D processing. To illustrate the efficacy of the proposed methods, we test the algorithms on both simulated imagery and video collected with a visible camera.

  12. Improving spatio-temporal resolution of infrared images to detect thermal activity of defect at the surface of inorganic glass

    Science.gov (United States)

    Corvec, Guillaume; Robin, Eric; Le Cam, Jean-Benoît; Sangleboeuf, Jean-Christophe; Lucas, Pierre

    2016-07-01

    This paper proposes a noise suppression methodology to improve the spatio-temporal resolution of infrared images. The methodology is divided in two steps. The first one consists in removing the noise from the temporal signal at each pixel. Three basic temporal filters are considered for this purpose: average filter, cost function minimization (FIT) and short time Fast Fourier Transform approach (STFFT). But while this step effectively reduces the temporal signal noise at each pixel, the infrared images may still appear noisy. This is due to a random distribution of a residual offset value of pixels signal. Hence in the second step, the residual offset is identified by considering thermal images for which no mechanical loading is applied. In this case, the temperature variation field is homogeneous and the value of temperature variation at each pixel is theoretically equal to zero. The method is first tested on synthetic images built from infrared computer-generated images combined with experimental noise. The results demonstrate that this approach permits to keep the spatial resolution of infrared images equal to 1 pixel. The methodology is then applied to characterize thermal activity of a defect at the surface of inorganic glass submitted to cyclic mechanical loading. The three basic temporal filters are quantitatively compared and contrasted. Results obtained demonstrate that, contrarily to a basic spatio-temporal approach, the denoising method proposed is suitable to characterize low thermal activity combined to strong spatial gradients induced by cyclic heterogeneous deformations.

  13. Adapt

    Science.gov (United States)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  14. Improvement of social adaptation in depression with serotonin and norepinephrine reuptake inhibitors

    Directory of Open Access Journals (Sweden)

    Mike Briley

    2010-09-01

    Full Text Available Mike Briley, Chantal MoretNeuroBiz Consulting and Communication, Castres, FranceAbstract: Depression is a disabling condition resulting in significant impairment in social functioning, involving the patient’s family, friends, work colleagues, and society at large. Although both psychologic and pharmacologic treatments generally improve many depressive symptoms, they do not always result in significant improvement in social functioning. The importance of recovery of social functioning in depressed patients is now widely appreciated, and studies are beginning to include it in evaluations of therapeutic efficacy. Among the various social adjustment evaluation rating scales, the Social Adaptation Self-Evaluation Scale, a social motivation and behavior scale, has been found to be simple to use and sensitive to change. Using this scale, the selective norepinephrine reuptake inhibitor, reboxetine, has been shown to be significantly more effective in improving social functioning than the selective serotonin reuptake inhibitor, fluoxetine. These findings are consistent with the notion that improvement in social adaptation involves functions depending primarily on noradrenergic neurotransmission. This hypothesis suggests that the serotonin and norepinephrine reuptake inhibitors, venlafaxine, duloxetine, and milnacipran, could be particularly helpful in improving social functioning. Preliminary studies with the serotonin and norepinephrine reuptake inhibitors suggest that they significantly improve social functioning. Comparative studies with selective serotonin reuptake inhibitors on the effects on social functioning should be encouraged.Keywords: Social Adaptation Self-Evaluation Scale, social functioning, depression, serotonin and norepinephrine reuptake inhibitors, noradrenergic neurotransmission

  15. Improving the adaptability of simulated evolutionary swarm robots in dynamically changing environments.

    Directory of Open Access Journals (Sweden)

    Yao Yao

    Full Text Available One of the important challenges in the field of evolutionary robotics is the development of systems that can adapt to a changing environment. However, the ability to adapt to unknown and fluctuating environments is not straightforward. Here, we explore the adaptive potential of simulated swarm robots that contain a genomic encoding of a bio-inspired gene regulatory network (GRN. An artificial genome is combined with a flexible agent-based system, representing the activated part of the regulatory network that transduces environmental cues into phenotypic behaviour. Using an artificial life simulation framework that mimics a dynamically changing environment, we show that separating the static from the conditionally active part of the network contributes to a better adaptive behaviour. Furthermore, in contrast with most hitherto developed ANN-based systems that need to re-optimize their complete controller network from scratch each time they are subjected to novel conditions, our system uses its genome to store GRNs whose performance was optimized under a particular environmental condition for a sufficiently long time. When subjected to a new environment, the previous condition-specific GRN might become inactivated, but remains present. This ability to store 'good behaviour' and to disconnect it from the novel rewiring that is essential under a new condition allows faster re-adaptation if any of the previously observed environmental conditions is reencountered. As we show here, applying these evolutionary-based principles leads to accelerated and improved adaptive evolution in a non-stable environment.

  16. Some Improvements on Active Queue Management Mechanism Based on Adaptive Fuzzy Control

    Directory of Open Access Journals (Sweden)

    Nguyen Kim Quoc

    2015-11-01

    Full Text Available Active queue management operates at network nodes to control the number of packets in the queue of nodes, by actively receiving packets when the queue is not full, removing packets when the queue is full or notifying bottlenecks even in the embryonic period of the bottlenecks due to to-be-full queue. In recent years, scientists have used fuzzy logic to improve queue management mechanisms. Overall, these improvements have used Mamdani fuzzy system with a fixed structure with triangular functions for input and output variables, so they do not adapt to the changing state of the network. We propose a adaptive fuzzy control (AFC model to improve the effectiveness of active queue management mechanisms.

  17. Improved Adaptive-Reinforcement Learning Control for morphing unmanned air vehicles.

    Science.gov (United States)

    Valasek, John; Doebbler, James; Tandale, Monish D; Meade, Andrew J

    2008-08-01

    This paper presents an improved Adaptive-Reinforcement Learning Control methodology for the problem of unmanned air vehicle morphing control. The reinforcement learning morphing control function that learns the optimal shape change policy is integrated with an adaptive dynamic inversion control trajectory tracking function. An episodic unsupervised learning simulation using the Q-learning method is developed to replace an earlier and less accurate Actor-Critic algorithm. Sequential Function Approximation, a Galerkin-based scattered data approximation scheme, replaces a K-Nearest Neighbors (KNN) method and is used to generalize the learning from previously experienced quantized states and actions to the continuous state-action space, all of which may not have been experienced before. The improved method showed smaller errors and improved learning of the optimal shape compared to the KNN. PMID:18632393

  18. An improved adaptive sampling and experiment design method for aerodynamic optimization

    Institute of Scientific and Technical Information of China (English)

    Huang Jiangtao; Gao Zhenghong; Zhou Zhu; Zhao Ke

    2015-01-01

    Experiment design method is a key to construct a highly reliable surrogate model for numerical optimization in large-scale project. Within the method, the experimental design criterion directly affects the accuracy of the surrogate model and the optimization efficient. According to the shortcomings of the traditional experimental design, an improved adaptive sampling method is pro-posed in this paper. The surrogate model is firstly constructed by basic sparse samples. Then the supplementary sampling position is detected according to the specified criteria, which introduces the energy function and curvature sampling criteria based on radial basis function (RBF) network. Sampling detection criteria considers both the uniformity of sample distribution and the description of hypersurface curvature so as to significantly improve the prediction accuracy of the surrogate model with much less samples. For the surrogate model constructed with sparse samples, the sample uniformity is an important factor to the interpolation accuracy in the initial stage of adaptive sam-pling and surrogate model training. Along with the improvement of uniformity, the curvature description of objective function surface gradually becomes more important. In consideration of these issues, crowdness enhance function and root mean square error (RMSE) feedback function are introduced in C criterion expression. Thus, a new sampling method called RMSE and crowd-ness enhance (RCE) adaptive sampling is established. The validity of RCE adaptive sampling method is studied through typical test function firstly and then the airfoil/wing aerodynamic opti-mization design problem, which has high-dimensional design space. The results show that RCE adaptive sampling method not only reduces the requirement for the number of samples, but also effectively improves the prediction accuracy of the surrogate model, which has a broad prospects for applications.

  19. A self-adaptive step Cuckoo search algorithm based on dimension by dimension improvement

    Directory of Open Access Journals (Sweden)

    Lu REN

    2015-10-01

    Full Text Available The choice of step length plays an important role in convergence speed and precision of Cuckoo search algorithm. In the paper, a self-adaptive step Cuckoo search algorithm based on dimensional improvement is provided. First, since the step in the original self-adaptive step Cuckoo search algorithm is not updated when the current position of the nest is in the optimal position, simple modification of the step is made for the update. Second, evaluation strategy based on dimension by dimension update is introduced to the modified self-adaptive step Cuckoo search algorithm. The experimental results show that the algorithm can balance the contradiction between the global convergence ability and the precision of optimization. Moreover, the proposed algorithm has better convergence speed.

  20. An improved adaptive Sage filter with applications in GEO orbit determination and GPS kinematic positioning

    Institute of Scientific and Technical Information of China (English)

    XU TianHe; JIANG Nan; SUN ZhangZhen

    2012-01-01

    The shortcomings of an adaptive Sage filter are analyzed in this paper.An improved adaptive Sage filter is developed by using a weighted average quadratic form of the historical residuals of observations and predicted states to evaluate the covariance matrices of observations and dynamic model errors at the present epoch.The weight function is constructed based on the variances of observational residuals or predicted state residuals and the space distance between the previous and the present epoch.In order to balance the contributions of the measurements and the dynamic model information,an adaptive factor is applied by using a two-segment function and predicted state discrepancy statistics.Two applications,orbit determination of a maneuvered GEO satellite and GPS kinematic positioning,are conducted to verify the performance of the proposed method.

  1. Moving forward with prisms: Sensory-motor adaptation improves gait initiation in Parkinson’s disease.

    Directory of Open Access Journals (Sweden)

    Janet Helen Bultitude

    2012-09-01

    Full Text Available It is postulated that the decreased walking speed; small, shuffling steps; and ‘freezing’ shown by patients with Parkinson’s disease could stem from an inability to tilt the body forward enough to provide sufficient forward propulsion. In two repeated-measures studies we examined whether adaptation to upward-shifting prisms, resulting in a downward after-effect, could improve gait initiation in healthy participants and patients with Parkinson’s disease. Faster forward stepping followed a brief (5 min exposure period for patients, and a longer (20 min exposure period for age-matched controls. Backward stepping was unchanged, and adaptation to downward-shifting prisms with control participants showed no effect on forward or backward stepping. These results suggest that adaptation of arm proprioception in the vertical plane may generalise to anterior-posterior postural control, presenting new possibilities for the treatment of gait disturbance in basal ganglia disorders.

  2. Improving the Response of Accelerometers for Automotive Applications by Using LMS Adaptive Filters: Part II

    Directory of Open Access Journals (Sweden)

    Eduardo Fernández

    2010-01-01

    Full Text Available In this paper, the fast least-mean-squares (LMS algorithm was used to both eliminate noise corrupting the important information coming from a piezoresisitive accelerometer for automotive applications, and improve the convergence rate of the filtering process based on the conventional LMS algorithm. The response of the accelerometer under test was corrupted by process and measurement noise, and the signal processing stage was carried out by using both conventional filtering, which was already shown in a previous paper, and optimal adaptive filtering. The adaptive filtering process relied on the LMS adaptive filtering family, which has shown to have very good convergence and robustness properties, and here a comparative analysis between the results of the application of the conventional LMS algorithm and the fast LMS algorithm to solve a real-life filtering problem was carried out. In short, in this paper the piezoresistive accelerometer was tested for a multi-frequency acceleration excitation. Due to the kind of test conducted in this paper, the use of conventional filtering was discarded and the choice of one adaptive filter over the other was based on the signal-to-noise ratio improvement and the convergence rate.

  3. Improving the response of accelerometers for automotive applications by using LMS adaptive filters: Part II.

    Science.gov (United States)

    Hernandez, Wilmar; de Vicente, Jesús; Sergiyenko, Oleg Y; Fernández, Eduardo

    2010-01-01

    In this paper, the fast least-mean-squares (LMS) algorithm was used to both eliminate noise corrupting the important information coming from a piezoresisitive accelerometer for automotive applications, and improve the convergence rate of the filtering process based on the conventional LMS algorithm. The response of the accelerometer under test was corrupted by process and measurement noise, and the signal processing stage was carried out by using both conventional filtering, which was already shown in a previous paper, and optimal adaptive filtering. The adaptive filtering process relied on the LMS adaptive filtering family, which has shown to have very good convergence and robustness properties, and here a comparative analysis between the results of the application of the conventional LMS algorithm and the fast LMS algorithm to solve a real-life filtering problem was carried out. In short, in this paper the piezoresistive accelerometer was tested for a multi-frequency acceleration excitation. Due to the kind of test conducted in this paper, the use of conventional filtering was discarded and the choice of one adaptive filter over the other was based on the signal-to-noise ratio improvement and the convergence rate. PMID:22315579

  4. An Improved NMS-Based Adaptive Edge Detection Method and Its FPGA Implementation

    Directory of Open Access Journals (Sweden)

    Enzeng Dong

    2016-01-01

    Full Text Available For improving the processing speed and accuracy of edge detection, an adaptive edge detection method based on improved NMS (nonmaximum suppression was proposed in this paper. In the method, the gradient image was computed by four directional Sobel operators. Then, the gradient image was processed by using NMS method. By defining a power map function, the elements values of gradient image histogram were mapped into a wider value range. By calculating the maximal between-class variance according to the mapped histogram, the corresponding threshold was obtained as adaptive threshold value in edge detection. Finally, to be convenient for engineering application, the proposed method was realized in FPGA (Field Programmable Gate Array. The experiment results demonstrated that the proposed method was effective in edge detection and suitable for real-time application.

  5. Improving Sensorimotor Adaptation Following Long Duration Space Flight by Enhancing Vestibular Information Transfer

    Science.gov (United States)

    Mulavara, A. P.; Kofman, I. S.; De Dios, Y. E; Galvan, R.; Goel, R.; Miller, C.; Peters, B.; Cohen, H. S.; Jeevarajan, J.; Reschke, M.; Wood, S.; Bergquist, F.; Seidler, R. D.; Bloomberg, J. J.

    2014-01-01

    Crewmember adapted to the microgravity state may need to egress the vehicle within a few minutes for safety and operational reasons after gravitational transitions. The transition from one sensorimotor state to another consists of two main mechanisms: strategic and plastic-adaptive and have been demonstrated in astronauts returning after long duration space flight. Strategic modifications represent "early adaptation" - immediate and transitory changes in control that are employed to deal with short-term changes in the environment. If these modifications are prolonged then plastic-adaptive changes are evoked that modify central nervous system function, automating new behavioral responses. More importantly, this longer term adaptive recovery mechanism was significantly associated with their strategic ability to recover on the first day after return to Earth G. We are developing a method based on stochastic resonance to enhance information transfer by improving the brain's ability to detect vestibular signals (Vestibular Stochastic Resonance, VSR) especially when combined with balance training exercises such as sensorimotor adaptability (SA) training for rapid improvement in functional skill, for standing and mobility. This countermeasure to improve detection of vestibular signals is a stimulus delivery system that is wearable/portable providing low imperceptible levels of white noise based binaural bipolar electrical stimulation of the vestibular system (stochastic vestibular stimulation). To determine efficacy of vestibular stimulation on physiological and perceptual responses during otolith-canal conflicts and dynamic perturbations we have conducted a series of studies: We have shown that imperceptible binaural bipolar electrical stimulation of the vestibular system across the mastoids enhances balance performance in the mediolateral (ML) plane while standing on an unstable surface. We have followed up on the previous study showing VSR stimulation improved balance

  6. Adaptive social learning strategies in temporally and spatially varying environments : how temporal vs. spatial variation, number of cultural traits, and costs of learning influence the evolution of conformist-biased transmission, payoff-biased transmission, and individual learning.

    Science.gov (United States)

    Nakahashi, Wataru; Wakano, Joe Yuichiro; Henrich, Joseph

    2012-12-01

    Long before the origins of agriculture human ancestors had expanded across the globe into an immense variety of environments, from Australian deserts to Siberian tundra. Survival in these environments did not principally depend on genetic adaptations, but instead on evolved learning strategies that permitted the assembly of locally adaptive behavioral repertoires. To develop hypotheses about these learning strategies, we have modeled the evolution of learning strategies to assess what conditions and constraints favor which kinds of strategies. To build on prior work, we focus on clarifying how spatial variability, temporal variability, and the number of cultural traits influence the evolution of four types of strategies: (1) individual learning, (2) unbiased social learning, (3) payoff-biased social learning, and (4) conformist transmission. Using a combination of analytic and simulation methods, we show that spatial-but not temporal-variation strongly favors the emergence of conformist transmission. This effect intensifies when migration rates are relatively high and individual learning is costly. We also show that increasing the number of cultural traits above two favors the evolution of conformist transmission, which suggests that the assumption of only two traits in many models has been conservative. We close by discussing how (1) spatial variability represents only one way of introducing the low-level, nonadaptive phenotypic trait variation that so favors conformist transmission, the other obvious way being learning errors, and (2) our findings apply to the evolution of conformist transmission in social interactions. Throughout we emphasize how our models generate empirical predictions suitable for laboratory testing.

  7. Improved estimation of the temporal decay function of in vivo metabolite signals

    NARCIS (Netherlands)

    Van Ormondt, D.; De Beer, R.; Van der Veen, J.W.C.; Sima, D.M.; Graveron-Demilly, D.

    2015-01-01

    MRI-scanners enable non-invasive, in vivo quantitation of metabolites in, e.g., the brain of a patient. Among other things, this requires adequate estimation of the unknown temporal decay function of the complex-valued signal emanating from the metabolites. We propose a method to render a current de

  8. Improved Cerebral Function in Mesial Temporal Lobe Epilepsy after Subtemporal Amygdalohippocampectomy

    Science.gov (United States)

    Takaya, Shigetoshi; Mikuni, Nobuhiro; Mitsueda, Takahiro; Satow, Takeshi; Taki, Junya; Kinoshita, Masako; Miyamoto, Susumu; Hashimoto, Nobuo; Ikeda, Akio; Fukuyama, Hidenao

    2009-01-01

    The functional changes that occur throughout the human brain after the selective removal of an epileptogenic lesion remain unclear. Subtemporal selective amygdalohippocampectomy (SAH) has been advocated as a minimally invasive surgical procedure for patients with medically intractable mesial temporal lobe epilepsy (MTLE). We evaluated the effects…

  9. Long-term effective population sizes, temporal stability of genetic composition and potential for local adaptation in anadromous brown trout ( Salmo trutta ) populations

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Ruzzante, D.E.; Eg Nielsen, Einar;

    2002-01-01

    (3 km) river showed Ne greater than or equal to 300. Assuming a stepping-stone model of gene flow we considered the relative roles of gene flow, random genetic drift and selection to assess the possibilities for local adaptation. The requirements for local adaptation were fulfilled, but only......We examined the long-term temporal (1910s to 1990s) genetic variation at eight microsatellite DNA loci in brown trout (Salmo trutta L) collected from five anadromous populations in Denmark to assess the long-term stability of genetic composition and to estimate effective population sizes (N......-e). Contemporary and historical samples consisted of tissue and archived scales, respectively. Pairwise Theta(ST) estimates, a hierarchical analysis of molecular variance (AMOVA) and multidimensional scaling analysis of pairwise genetic distances between samples revealed much closer genetic relationships among...

  10. Iterative Process to Improve Simple Adaptive Subdivision Surfaces Method for Triangular Meshes

    Directory of Open Access Journals (Sweden)

    Noor A. Husain

    2011-01-01

    Full Text Available Problem statement: Subdivision surfaces were applied to the entire meshes in order to produce smooth surfaces refinement from coarse mesh. Several schemes had been introduced in this area to provide a set of rules to converge smooth surfaces. However, to compute and render all the vertices are really inconvenient in terms of memory consumption and runtime during the subdivision process. It will lead to a heavy computational load especially at a higher level of subdivision. Adaptive subdivision is a method that subdivides only at certain areas of the meshes. Although subdivision occurs at the selected areas, quality of produced surfaces can be preserved similar to a regular subdivision surfaces. Nevertheless, adaptive subdivision process suffers because of two reasons; calculations need to be done to define areas that required to be subdivided and to remove cracks created from the subdivision depth difference between selected and unselected areas. Cracks must be removed because it creates artifacts in editing, rendering and processing of the mesh. Approach: This research brings to iterative adaptive subdivision to improve simple adaptive subdivision surfaces method for triangular meshes. Results: The result of this iterative process presented to produce fewer polygons while it preserve smoother. Conclusion: The proposed method created surfaces of better quality, computationally more efficient and occupied less memory as compared to original method.

  11. Research on Improved Adaptive Control for Static Synchronous Compensator in Power System

    Directory of Open Access Journals (Sweden)

    Chao Zhang

    2015-01-01

    Full Text Available This paper deals with the problems of “explosion of term,” uncertain parameter in static synchronous compensator (STATCOM system with nonlinear time-delay. An improved adaptive controller is proposed to enhance the transient stability of system states and reduce computational complexity of STATCOM control system. In contrast to backstepping control scheme in high order systems, the problem of “explosion of term” is avoided by designing dynamic surface controller. The low pass filter is included to allow a design where the model is not differentiated and thus has prevented the mathematical complexities effectively. In addition, unlike the traditional adaptive control schemes, the certainty equivalence principle is not required for estimating the uncertain parameter by system immersion and manifold invariant (I&I adaptive control. A smooth function is added to ensure that the estimation error converges to zero in finite time. The effectiveness of the proposed controller is verified by the simulations. Compared with adaptive backstepping and proportion integration differentiation (PID, the oscillation amplitudes of transient response are reduced by nearly half, and the time of reaching steady state is shortened by at least 11%.

  12. Physical Exercise Leads to Rapid Adaptations in Hippocampal Vasculature : Temporal Dynamics and Relationship to Cell Proliferation and Neurogenesis

    NARCIS (Netherlands)

    Van der Borght, Karin; Kobor-Nyakas, Dora E.; Klauke, Karin; Eggen, Bart J. L.; Nyakas, Csaba; Van der Zee, Eddy A.; Meerlo, Peter

    2009-01-01

    Increased levels of angiogenesis and neurogenesis possibly mediate the beneficial effects of physical activity on hippocampal plasticity. This study was designed to investigate the temporal dynamics of exercise-induced changes in hippocampal angiogenesis and cell proliferation. Mice were housed with

  13. Improving Early Adaptation Following Long Duration Spaceflight by Enhancing Vestibular Information

    Science.gov (United States)

    Mulavara, Ajitkumar; Kofman, Igor; DeDios, Yiri E.; Galvan, Raquel; Miller, Chris; Peters, Brian; Cohen, Helen; Jeevarajan, Jerome; Reschke, Millard; Wood, Scott; Bloomberg, Jacob

    2014-01-01

    Crewmember adapted to the microgravity state may need to egress the vehicle within a few minutes for safety and operational reasons after g-transitions. The transition from one sensorimotor state to another consists of two main mechanisms: strategic and plastic-adaptive and have been demonstrated in astronauts returning after long duration space flight. Strategic modifications represent "early adaptation" -immediate and transitory changes in control that are employed to deal with short-term changes in the environment. If these modifications are prolonged then plastic-adaptive changes are evoked that modify central nervous system function, automating new behavioral responses. More importantly, this longer term adaptive recovery mechanism was significantly associated with their strategic ability to recover on the first day after return to Earth G. We are developing a method based on stochastic resonance (SR) to enhance information transfer by improving the brain's ability to detect vestibular signals especially when combined with balance training exercises for rapid improvement in functional skill, for standing and mobility. The countermeasure to improve post-flight balance and locomotor disturbances is a stimulus delivery system that is wearable/portable providing low imperceptible levels of white noise based binaural bipolar electrical stimulation of the vestibular system (stochastic vestibular stimulation, SVS). The techniques for improving signal detection using SVS may thus provide additional information to improve such strategic abilities and thus help in significantly reducing the number of days required to recover functional performance to preflight levels after long duration space flight. We have conducted a series of studies to document the efficacy of SVS stimulation on balance/locomotion tasks on unstable surfaces and motion tracking tasks during intra-vestibular system conflicts. In an initial study, we showed that SVS improved overall balance

  14. Improvement of the temporal resolution of cardiac CT reconstruction algorithms using an optimized filtering step

    Energy Technology Data Exchange (ETDEWEB)

    Roux, S. [Universite Joseph Fourier, TIMC-IMAG, In3S, Faculte de Medecine, 38 - Grenoble (France)]|[CEA Grenoble, Lab. d' Electronique et de Technologie de l' Informatique (LETI), 38 (France); Desbat, L. [Universite Joseph Fourier, UMR CNRS 5525, 38 - Grenoble (France); Koenig, A.; Grangeat, P. [CEA Grenoble, Lab. d' Electronique et de Technologie de l' Informatique (LETI), 38 (France)

    2005-07-01

    In this paper we study a property of the filtering step of multi-cycle reconstruction algorithm used in the field of cardiac CT. We show that the common filtering step procedure is not optimal in the case of divergent geometry and decrease slightly the temporal resolution. We propose to use the filtering procedure related to the work of Noo at al ( F.Noo, M. Defrise, R. Clakdoyle, and H. Kudo. Image reconstruction from fan-beam projections on less than a short-scan. Phys. Med.Biol., 47:2525-2546, July 2002)and show that this alternative allows to reach the optimal temporal resolution with the same computational effort. (N.C.)

  15. Incorporating temporal variability to improve geostatistical analysis of satellite-observed CO2 in China

    Institute of Scientific and Technical Information of China (English)

    ZENG ZhaoCheng; LEI LiPing; GUO LiJie; ZHANG Li; ZHANG Bing

    2013-01-01

    Observations of atmospheric carbon dioxide (CO2) from satellites offer new data sources to understand global carbon cycling.The correlation structure of satellite-observed CO2 can be analyzed and modeled by geostatistical methods,and CO2 values at unsampled locations can be predicted with a correlation model.Conventional geostatistical analysis only investigates the spatial correlation of CO2,and does not consider temporal variation in the satellite-observed CO2 data.In this paper,a spatiotemporal geostatistical method that incorporates temporal variability is implemented and assessed for analyzing the spatiotemporal correlation structure and prediction of monthly CO2 in China.The spatiotemporal correlation is estimated and modeled by a product-sum variogram model with a global nugget component.The variogram result indicates a significant degree of temporal correlation within satellite-observed CO2 data sets in China.Prediction of monthly CO2 using the spatiotemporal variogram model and spacetime kriging procedure is implemented.The prediction is compared with a spatial-only geostatistical prediction approach using a cross-validation technique.The spatiotemporal approach gives better results,with higher correlation coefficient (r2),and less mean absolute prediction error and root mean square error.Moreover,the monthly mapping result generated from the spatiotemporal approach has less prediction uncertainty and more detailed spatial variation of CO2 than those from the spatial-only approach.

  16. SU-E-I-38: Improved Metal Artifact Correction Using Adaptive Dual Energy Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Dong, X; Elder, E; Roper, J; Dhabaan, A [Winship Cancer Institute of Emory University (United States)

    2015-06-15

    Purpose: The empirical dual energy calibration (EDEC) method corrects for beam-hardening artifacts, but shows limited performance on metal artifact correction. In this work, we propose an adaptive dual energy calibration (ADEC) method to correct for metal artifacts. Methods: The empirical dual energy calibration (EDEC) method corrects for beam-hardening artifacts, but shows limited performance on metal artifact correction. In this work, we propose an adaptive dual energy calibration (ADEC) method to correct for metal artifacts. Results: Highly attenuating copper rods cause severe streaking artifacts on standard CT images. EDEC improves the image quality, but cannot eliminate the streaking artifacts. Compared to EDEC, the proposed ADEC method further reduces the streaking resulting from metallic inserts and beam-hardening effects and obtains material decomposition images with significantly improved accuracy. Conclusion: We propose an adaptive dual energy calibration method to correct for metal artifacts. ADEC is evaluated with the Shepp-Logan phantom, and shows superior metal artifact correction performance. In the future, we will further evaluate the performance of the proposed method with phantom and patient data.

  17. Adaptive optics in spinning disk microscopy: improved contrast and brightness by a simple and fast method.

    Science.gov (United States)

    Fraisier, V; Clouvel, G; Jasaitis, A; Dimitrov, A; Piolot, T; Salamero, J

    2015-09-01

    Multiconfocal microscopy gives a good compromise between fast imaging and reasonable resolution. However, the low intensity of live fluorescent emitters is a major limitation to this technique. Aberrations induced by the optical setup, especially the mismatch of the refractive index and the biological sample itself, distort the point spread function and further reduce the amount of detected photons. Altogether, this leads to impaired image quality, preventing accurate analysis of molecular processes in biological samples and imaging deep in the sample. The amount of detected fluorescence can be improved with adaptive optics. Here, we used a compact adaptive optics module (adaptive optics box for sectioning optical microscopy), which was specifically designed for spinning disk confocal microscopy. The module overcomes undesired anomalies by correcting for most of the aberrations in confocal imaging. Existing aberration detection methods require prior illumination, which bleaches the sample. To avoid multiple exposures of the sample, we established an experimental model describing the depth dependence of major aberrations. This model allows us to correct for those aberrations when performing a z-stack, gradually increasing the amplitude of the correction with depth. It does not require illumination of the sample for aberration detection, thus minimizing photobleaching and phototoxicity. With this model, we improved both signal-to-background ratio and image contrast. Here, we present comparative studies on a variety of biological samples.

  18. Application and improvement of an adaptive ensemble Kalman filter for soil moisture data assimilation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Accurate assignment of model and observation errors is crucial for the successful application of land surface data assimilation algorithms. Poorly-specified model and observation errors can significantly degrade assimilation results. In 2008, Reichle et al. developed an operational procedure to adaptively tune model and observation errors. In this paper, we modified and applied Reichle’s procedure in the Noah land surface model to assimilate observed surface soil moisture data. Numerical simulations showed that: (1) the best estimate of model and observation errors appears when the empirical factor β equals 1.02; (2) the Reichle procedure can be deployed to adaptively tune errors if their true values change slowly; and (3) convergence of the Reichle procedure was improved using better initial errors achieved by iterative computations.

  19. Adaptive Harmonic Detection Control of Grid Interfaced Solar Photovoltaic Energy System with Power Quality Improvement

    Science.gov (United States)

    Singh, B.; Goel, S.

    2015-03-01

    This paper presents a grid interfaced solar photovoltaic (SPV) energy system with a novel adaptive harmonic detection control for power quality improvement at ac mains under balanced as well as unbalanced and distorted supply conditions. The SPV energy system is capable of compensation of linear and nonlinear loads with the objectives of load balancing, harmonics elimination, power factor correction and terminal voltage regulation. The proposed control increases the utilization of PV infrastructure and brings down its effective cost due to its other benefits. The adaptive harmonic detection control algorithm is used to detect the fundamental active power component of load currents which are subsequently used for reference source currents estimation. An instantaneous symmetrical component theory is used to obtain instantaneous positive sequence point of common coupling (PCC) voltages which are used to derive inphase and quadrature phase voltage templates. The proposed grid interfaced PV energy system is modelled and simulated in MATLAB Simulink and its performance is verified under various operating conditions.

  20. Genomic Measures to Predict Adaptation to Novel Sensorimotor Environments and Improve Personalization of Countermeasure Design

    Science.gov (United States)

    Kreutzberg, G. A.; Zanello, S.; Seidler, R. D.; Peters, B.; De Dios, Y. E.; Gadd, N. E.; Bloomberg, J. J.; Mulavara, A. P.

    2016-01-01

    Introduction. Astronauts experience sensorimotor disturbances during their initial exposure to microgravity and during the re-adaptation phase following a return to an Earth-gravitational environment. These alterations may affect crewmembers' ability to perform mission-critical functional tasks. Interestingly, astronauts have shown significant inter-subject variation in adaptive capability during gravitational transitions. The ability to predict the manner and degree to which individual astronauts would be affected would improve the efficacy of personalized countermeasure training programs designed to enhance sensorimotor adaptability. The success of such an approach depends on the development of predictive measures of sensorimotor adaptation, which would ascertain each crewmember's adaptive capacity. The goal of this study is to determine whether specific genetic polymorphisms have significant influence on sensorimotor adaptability, which can help inform the design of personalized training countermeasures. Methods. Subjects (n=15) were tested on their ability to negotiate a complex obstacle course for ten test trials while wearing up-down vision-displacing goggles. This presented a visuomotor challenge while doing a full body task. The first test trial time and the recovery rate over the ten trials were used as adaptability performance metrics. Four single nucleotide polymorphisms (SNPs) were selected for their role in neural pathways underlying sensorimotor adaptation and were identified in subjects' DNA extracted from saliva samples: catechol-O-methyl transferase (COMT, rs4680), dopamine receptor D2 (DRD2, rs1076560), brain-derived neurotrophic factor genes (BDNF, rs6265), and the DraI polymorphism of the alpha-2 adrenergic receptor. The relationship between the SNPs and test performance was assessed by assigning subjects a rank score based on their adaptability performance metrics and comparing gene expression between the top half and bottom half performers

  1. Motion-aware temporal regularization for improved 4D cone-beam computed tomography

    Science.gov (United States)

    Mory, Cyril; Janssens, Guillaume; Rit, Simon

    2016-09-01

    Four-dimensional cone-beam computed tomography (4D-CBCT) of the free-breathing thorax is a valuable tool in image-guided radiation therapy of the thorax and the upper abdomen. It allows the determination of the position of a tumor throughout the breathing cycle, while only its mean position can be extracted from three-dimensional CBCT. The classical approaches are not fully satisfactory: respiration-correlated methods allow one to accurately locate high-contrast structures in any frame, but contain strong streak artifacts unless the acquisition is significantly slowed down. Motion-compensated methods can yield streak-free, but static, reconstructions. This work proposes a 4D-CBCT method that can be seen as a trade-off between respiration-correlated and motion-compensated reconstruction. It builds upon the existing reconstruction using spatial and temporal regularization (ROOSTER) and is called motion-aware ROOSTER (MA-ROOSTER). It performs temporal regularization along curved trajectories, following the motion estimated on a prior 4D CT scan. MA-ROOSTER does not involve motion-compensated forward and back projections: the input motion is used only during temporal regularization. MA-ROOSTER is compared to ROOSTER, motion-compensated Feldkamp–Davis–Kress (MC-FDK), and two respiration-correlated methods, on CBCT acquisitions of one physical phantom and two patients. It yields streak-free reconstructions, visually similar to MC-FDK, and robust information on tumor location throughout the breathing cycle. MA-ROOSTER also allows a variation of the lung tissue density during the breathing cycle, similar to that of planning CT, which is required for quantitative post-processing.

  2. Improving LIGO calibration accuracy by tracking and compensating for slow temporal variations

    CERN Document Server

    Tuyenbayev, D; Betzwieser, J; Cahillane, C; Goetz, E; Izumi, K; Kandhasamy, S; Kissel, J S; Mendell, G; Wade, M; Weinstein, A J; Savage, R L

    2016-01-01

    Calibration of the second-generation LIGO interferometric gravitational-wave detectors employs a method that uses injected periodic modulations to track and compensate for slow temporal variations in the differential length response of the instruments. These detectors utilize feedback control loops to maintain resonance conditions by suppressing differential arm length variations. We describe how the sensing and actuation functions of these servo loops are parameterized and how the slow variations in these parameters are quantified using the injected modulations. We report the results of applying this method to the LIGO detectors and show that it significantly reduces systematic errors in their calibrated outputs.

  3. Focal and temporal release of glutamate in the mushroom bodies improves olfactory memory in Apis mellifera.

    Science.gov (United States)

    Locatelli, Fernando; Bundrock, Gesine; Müller, Uli

    2005-12-14

    In contrast to vertebrates, the role of the neurotransmitter glutamate in learning and memory in insects has hardly been investigated. The reason is that a pharmacological characterization of insect glutamate receptors is still missing; furthermore, it is difficult to locally restrict pharmacological interventions. In this study, we overcome these problems by using locally and temporally defined photo-uncaging of glutamate to study its role in olfactory learning and memory formation in the honeybee, Apis mellifera. Uncaging glutamate in the mushroom bodies immediately after a weak training protocol induced a higher memory rate 2 d after training, mimicking the effect of a strong training protocol. Glutamate release before training does not facilitate memory formation, suggesting that glutamate mediates processes triggered by training and required for memory formation. Uncaging glutamate in the antennal lobes shows no effect on memory formation. These results provide the first direct evidence for a temporally and locally restricted function of glutamate in memory formation in honeybees and insects. PMID:16354919

  4. Improved prediction error filters for adaptive feedback cancellation in hearing aids

    DEFF Research Database (Denmark)

    Ngo, Kim; van Waterschoot, Toon; Christensen, Mads Græsbøll;

    2013-01-01

    Acoustic feedback is a well-known problem in hearing aids, caused by the undesired acoustic coupling between the hearing aid loudspeaker and microphone. Acoustic feedback produces annoying howling sounds and limits the maximum achievable hearing aid amplification. This paper is focused on adaptive...... a number of improved PEF designs that are inspired by harmonic sinusoidal modeling and pitch prediction of speech signals. The resulting PEM-based AFC algorithms are evaluated in terms of the maximum stable gain (MSG), filter misadjustment, and computational complexity. Simulation results for a hearing aid...

  5. Adaptive Agent Model with Hybrid Routing Selection Strategy for Improving the Road-Network Congestion Problem

    Institute of Scientific and Technical Information of China (English)

    Bin Jiang; Chao Yang; Takao Terano

    2015-01-01

    This paper proposes an adaptive agent model with a hybrid routing selection strategy for studying the road⁃network congestion problem. We focus on improving those severely congested links. Firstly, a multi⁃agent system is built, where each agent stands for a vehicle, and it makes its routing selection by considering the shortest path and the minimum congested degree of the target link simultaneously. The agent⁃based model captures the nonlinear feedback between vehicle routing behaviors and road⁃network congestion status. Secondly, a hybrid routing selection strategy is provided, which guides the vehicle routes adapting to the real⁃time road⁃network congestion status. On this basis, we execute simulation experiments and compare the simulation results of network congestion distribution, by Floyd agent with shortest path strategy and our proposed adaptive agent with hybrid strategy. The simulation results show that our proposed model has reduced the congestion degree of those seriously congested links of road⁃network. Finally, we execute our model on a real road map. The results finds that those seriously congested roads have some common features such as located at the road junction or near the unique road connecting two areas. And, the results also show an effectiveness of our model on reduction of those seriously congested links in this actual road network. Such a bottom⁃up congestion control approach with a hybrid congestion optimization perspective will have its significance for actual traffic congestion control.

  6. An Improved Adaptive Multi-way Principal Component Analysis for Monitoring Streptomycin Fermentation Process

    Institute of Scientific and Technical Information of China (English)

    何宁; 王树青; 谢磊

    2004-01-01

    Multi-way principal component analysis (MPCA) had been successfully applied to monitoring the batch and semi-batch process in most chemical industry. An improved MPCA approach, step-by-step adaptive MPCA (SAMPCA), using the process variable trajectories to monitoring the batch process is presented in this paper. It does not need to estimate or fill in the unknown part of the process variable trajectory deviation from the current time until the end. The approach is based on a MPCA method that processes the data in a sequential and adaptive manner. The adaptive rate is easily controlled through a forgetting factor that controls the weight of past data in a summation. This algorithm is used to evaluate the industrial streptomycin fermentation process data and is compared with the traditional MPCA. The results show that the method is more advantageous than MPCA, especially when monitoring multi-stage batch process where the latent vector structure can change at several points during the batch.

  7. Spatial Pattern and Temporal Variation Law-Based Multi-Sensor Collaboration Method for Improving Regional Soil Moisture Monitoring Capabilities

    Directory of Open Access Journals (Sweden)

    Xiang Zhang

    2014-12-01

    Full Text Available Regional soil moisture distributions and changes are critical for agricultural production and environmental modeling. Currently, hundreds of satellite sensors exist with different soil moisture observation capabilities. However, multi-sensor collaborative observation mechanisms for improving regional soil moisture monitoring capabilities are lacking. In this study, a Spatial pattern and Temporal variation law-based Multi-sensor Collaboration (STMC method is proposed to solve this problem. The first component of the STMC method deduces the regional soil moisture distribution and variation patterns based on time stability theory and long-term statistical analyses. The second component of the STMC method detects potential anomalous soil moisture events and immediately triggers the high spatial resolution sensor with the soonest pass-over time. In the detection phase, an anomalous soil moisture judgment (ASMJ algorithm and high temporal resolution sensors (the Advanced Microwave Scanning Radiometer 2 (AMSR2 were utilized. Experiments conducted in Hubei province, China, demonstrated that the proposed STMC method was capable of accurately identifying of anomalous soil moisture conditions caused by waterlogging and drought events. Additionally, we observed that the STMC method combined the advantages of different long-term observation, high temporal, and high spatial resolution sensors synergistically for monitoring purposes.

  8. Improved Reproduction of Stops in Noise Reduction Systems with Adaptive Windows and Nonstationarity Detection

    Directory of Open Access Journals (Sweden)

    Dirk Mauler

    2009-01-01

    Full Text Available A new block-based noise reduction system is proposed which focuses on the preservation of transient sounds like stops or speech onsets. The power level of consonants has been shown to be important for speech intelligibility. In single-channel noise reduction systems, however, these sounds are frequently severely attenuated. The main reasons for this are an insufficient temporal resolution of transient sounds and a delayed tracking of important control parameters. The key idea of the proposed system is the detection of non-stationary input data. Depending on that decision, a pair of spectral analysis-synthesis windows is selected which either provides high temporal or high spectral resolution. Furthermore, the decision-directed approach for the estimation of the a priori SNR is modified so that speech onsets are tracked more quickly without sacrificing performance in stationary signal regions. The proposed solution shows significant improvements in the preservation of stops with an overall system delay (input-output, excluding group delay of noise reduction filter of only 10 milliseconds.

  9. High baseline activity in inferior temporal cortex improves neural and behavioral discriminability during visual categorization

    Directory of Open Access Journals (Sweden)

    Nazli eEmadi

    2014-11-01

    Full Text Available Spontaneous firing is a ubiquitous property of neural activity in the brain. Recent literature suggests that this baseline activity plays a key role in perception. However, it is not known how the baseline activity contributes to neural coding and behavior. Here, by recording from the single neurons in the inferior temporal cortex of monkeys performing a visual categorization task, we thoroughly explored the relationship between baseline activity, the evoked response, and behavior. Specifically we found that a low-frequency (< 8 Hz oscillation in the spike train, prior and phase-locked to the stimulus onset, was correlated with increased gamma power and neuronal baseline activity. This enhancement of the baseline activity was then followed by an increase in the neural selectivity and the response reliability and eventually a higher behavioral performance.

  10. Use of Adaptive Digital Signal Processing to Improve Speech Communication for Normally Hearing aand Hearing-Impaired Subjects.

    Science.gov (United States)

    Harris, Richard W.; And Others

    1988-01-01

    A two-microphone adaptive digital noise cancellation technique improved word-recognition ability for 20 normal and 12 hearing-impaired adults by reducing multitalker speech babble and speech spectrum noise 18-22 dB. Word recognition improvements averaged 37-50 percent for normal and 27-40 percent for hearing-impaired subjects. Improvement was best…

  11. Improved temporal resolution in process-based modelling of agricultural soil ammonia emissions

    Science.gov (United States)

    Beuning, J. D.; Pattey, E.; Edwards, G.; Van Heyst, B. J.

    An emerging environmental issue in Canada is how to quantify the contribution of agricultural soil emissions of ammonia (NH 3) to environmental pollution. Emission inventories are essential to predict these emissions and their subsequent atmospheric transportation, transformation, and deposition. Due to the high spatial and temporal variability associated with NH 3 emissions, emission inventories based on measurements become expensive and emission factors lose accuracy. Process-based models are capable of accounting for the complex soil interactions, but current models lack temporal refinement and few models consider NH 3 emissions. This paper presents the development of a one-dimensional (vertical), time-dependent model capable of predicting NH 3 emissions from a slurry applied to a bare soil. The model is based on chemical, physical and biological relationships that govern soil heat, moisture, and nitrogen movement. Processes considered include convection, diffusion, decomposition, nitrification, denitrification, and surface to atmosphere transport. The model is tested with experimental data from Agriculture and Agri-Food Canada which conducted NH 3 measurements following application of dairy cattle slurry to a bare field. An investigation into the sensitivity of emissions to pH and slurry infiltration rate is conducted and model predictions are best fit to measurements based on this investigation. Testing demonstrated the model's ability to predict the large NH 3 emissions immediately following application and subsequent emission trends associated with diurnal patterns that emission factors cannot capture. Results showed that model performance could benefit from a more in depth measurement program and empirical or process models of surface pH. Potential exists for the model to become a useful tool in predicting emissions on local, regional, or national scales.

  12. Luminance and opponent-color contributions to visual detection and adaptation and to temporal and spatial integration.

    Science.gov (United States)

    King-Smith, P E; Carden, D

    1976-07-01

    We show how the processes of visual detection and of temporal and spatial summation may be analyzed in terms of parallel luminance (achromatic) and opponent-color systems; a test flash is detected if it exceeds the threshold of either system. The spectral sensitivity of the luminance system may be determined by a flicker method, and has a single broad peak near 555 nm; the spectral sensitivity of the opponent-color system corresponds to the color recognition threshold, and has three peaks at about 440, 530, and 600 nm (on a white background). The temporal and spatial integration of the opponent-color system are generally greater than for the luminance system; further, a white background selectively depresses the sensitivity of the luminance system relative to the opponent-color system. Thus relatively large (1 degree) and long (200 msec) spectral test flashes on a white background are detected by the opponent-color system except near 570 nm; the contribution of the luminance system becomes more prominent if the size or duration of the test flash is reduced, or if the white background is extinguished. The present analysis is discussed in relation to Stiles' model of independent eta mechanisms. PMID:978286

  13. An improved cooperative adaptive cruise control (CACC) algorithm considering invalid communication

    Science.gov (United States)

    Wang, Pangwei; Wang, Yunpeng; Yu, Guizhen; Tang, Tieqiao

    2014-05-01

    For the Cooperative Adaptive Cruise Control (CACC) Algorithm, existing research studies mainly focus on how inter-vehicle communication can be used to develop CACC controller, the influence of the communication delays and lags of the actuators to the string stability. However, whether the string stability can be guaranteed when inter-vehicle communication is invalid partially has hardly been considered. This paper presents an improved CACC algorithm based on the sliding mode control theory and analyses the range of CACC controller parameters to maintain string stability. A dynamic model of vehicle spacing deviation in a platoon is then established, and the string stability conditions under improved CACC are analyzed. Unlike the traditional CACC algorithms, the proposed algorithm can ensure the functionality of the CACC system even if inter-vehicle communication is partially invalid. Finally, this paper establishes a platoon of five vehicles to simulate the improved CACC algorithm in MATLAB/Simulink, and the simulation results demonstrate that the improved CACC algorithm can maintain the string stability of a CACC platoon through adjusting the controller parameters and enlarging the spacing to prevent accidents. With guaranteed string stability, the proposed CACC algorithm can prevent oscillation of vehicle spacing and reduce chain collision accidents under real-world circumstances. This research proposes an improved CACC algorithm, which can guarantee the string stability when inter-vehicle communication is invalid.

  14. An adaptive threshold based image processing technique for improved glaucoma detection and classification.

    Science.gov (United States)

    Issac, Ashish; Partha Sarathi, M; Dutta, Malay Kishore

    2015-11-01

    Glaucoma is an optic neuropathy which is one of the main causes of permanent blindness worldwide. This paper presents an automatic image processing based method for detection of glaucoma from the digital fundus images. In this proposed work, the discriminatory parameters of glaucoma infection, such as cup to disc ratio (CDR), neuro retinal rim (NRR) area and blood vessels in different regions of the optic disc has been used as features and fed as inputs to learning algorithms for glaucoma diagnosis. These features which have discriminatory changes with the occurrence of glaucoma are strategically used for training the classifiers to improve the accuracy of identification. The segmentation of optic disc and cup based on adaptive threshold of the pixel intensities lying in the optic nerve head region. Unlike existing methods the proposed algorithm is based on an adaptive threshold that uses local features from the fundus image for segmentation of optic cup and optic disc making it invariant to the quality of the image and noise content which may find wider acceptability. The experimental results indicate that such features are more significant in comparison to the statistical or textural features as considered in existing works. The proposed work achieves an accuracy of 94.11% with a sensitivity of 100%. A comparison of the proposed work with the existing methods indicates that the proposed approach has improved accuracy of classification glaucoma from a digital fundus which may be considered clinically significant. PMID:26321351

  15. Demonstration of a double chirped-pulse-amplification front-end system to improve the temporal contrast at a sub-petawatt laser

    Science.gov (United States)

    Xie, Na; Zhou, Kainan; Huang, Wanqing; Wang, Xiaodong; Sun, Li; Guo, Yi; Li, Qing

    2012-02-01

    The temporal contrast is an important factor affecting the application of ultra-intense and ultra-short lasers. In this paper, we develop a double chirped-pulse-amplification (CPA) front-end system with an intermediate nonlinear temporal pulse filter to improve the temporal contrast at a sub-petawatt Ti:sapphire laser facility, i.e. the super intense laser for experiment on the extremes (SILEX-I). The temporal pulse filter employs cross-polarized wave (XPW) generation to suppress the amplified spontaneous emission (ASE). The design output energy is 320 mJ for the front-end system. The experimental results show that the output energy of the double CPA system is 360 mJ. The ASE pedestal is suppressed significantly and the temporal contrast is improved by around three orders of magnitude.

  16. Improving Accuracy and Temporal Resolution of Learning Curve Estimation for within- and across-Session Analysis.

    Directory of Open Access Journals (Sweden)

    Matthias Deliano

    Full Text Available Estimation of learning curves is ubiquitously based on proportions of correct responses within moving trial windows. Thereby, it is tacitly assumed that learning performance is constant within the moving windows, which, however, is often not the case. In the present study we demonstrate that violations of this assumption lead to systematic errors in the analysis of learning curves, and we explored the dependency of these errors on window size, different statistical models, and learning phase. To reduce these errors in the analysis of single-subject data as well as on the population level, we propose adequate statistical methods for the estimation of learning curves and the construction of confidence intervals, trial by trial. Applied to data from an avoidance learning experiment with rodents, these methods revealed performance changes occurring at multiple time scales within and across training sessions which were otherwise obscured in the conventional analysis. Our work shows that the proper assessment of the behavioral dynamics of learning at high temporal resolution can shed new light on specific learning processes, and, thus, allows to refine existing learning concepts. It further disambiguates the interpretation of neurophysiological signal changes recorded during training in relation to learning.

  17. Improving Accuracy and Temporal Resolution of Learning Curve Estimation for within- and across-Session Analysis.

    Science.gov (United States)

    Deliano, Matthias; Tabelow, Karsten; König, Reinhard; Polzehl, Jörg

    2016-01-01

    Estimation of learning curves is ubiquitously based on proportions of correct responses within moving trial windows. Thereby, it is tacitly assumed that learning performance is constant within the moving windows, which, however, is often not the case. In the present study we demonstrate that violations of this assumption lead to systematic errors in the analysis of learning curves, and we explored the dependency of these errors on window size, different statistical models, and learning phase. To reduce these errors in the analysis of single-subject data as well as on the population level, we propose adequate statistical methods for the estimation of learning curves and the construction of confidence intervals, trial by trial. Applied to data from an avoidance learning experiment with rodents, these methods revealed performance changes occurring at multiple time scales within and across training sessions which were otherwise obscured in the conventional analysis. Our work shows that the proper assessment of the behavioral dynamics of learning at high temporal resolution can shed new light on specific learning processes, and, thus, allows to refine existing learning concepts. It further disambiguates the interpretation of neurophysiological signal changes recorded during training in relation to learning. PMID:27303809

  18. Improvement in DMSA imaging using adaptive noise reduction: an ROC analysis.

    Science.gov (United States)

    Lorimer, Lisa; Gemmell, Howard G; Sharp, Peter F; McKiddie, Fergus I; Staff, Roger T

    2012-11-01

    Dimercaptosuccinic acid imaging is the 'gold standard' for the detection of cortical defects and diagnosis of scarring of the kidneys. The Siemens planar processing package, which implements adaptive noise reduction using the Pixon algorithm, is designed to allow a reduction in image noise, enabling improved image quality and reduced acquisition time/injected activity. This study aimed to establish the level of improvement in image quality achievable using this algorithm. Images were acquired of a phantom simulating a single kidney with a range of defects of varying sizes, positions and contrasts. These images were processed using the Pixon processing software and shown to 12 observers (six experienced and six novices) who were asked to rate the images on a six-point scale depending on their confidence that a defect was present. The data were analysed using a receiver operating characteristic approach. Results showed that processed images significantly improved the performance of the experienced observers in terms of their sensitivity and specificity. Although novice observers showed significant increase in sensitivity when using the software, a significant decrease in specificity was also seen. This study concludes that the Pixon software can be used to improve the assessment of cortical defects in dimercaptosuccinic acid imaging by suitably trained observers.

  19. Development of Adaptive Feedback Control System of Both Spatial and Temporal Beam Shaping for UV-Laser Light Source for RF Gun

    CERN Document Server

    Tomizawa, H; Dewa, H; Hanaki, H; Kobayashi, T; Mizuno, A; Suzuki, S; Taniuchi, T; Yanagida, K

    2004-01-01

    The ideal spatial and temporal profiles of a shot-by-shot single laser pulse are essential to suppress the emittance growth of the electron beam from a photo-cathode rf gun. We have been developing highly qualified UV-laser pulse as a light source of the rf gun for an injector candidate of future light sources. The gun cavity is a single-cell pillbox, and the copper inner wall is used as a photo cathode. The electron beam was accelerated up to 4.1 MeV at the maximum electric field on the cathode surface of 175 MV/m. For emittance compensation, two solenoid coils were used. As the first test run, with a microlens array as a simple spatial shaper, we obtained a minimum emittance value of 2 π·mm·mrad with a beam energy of 3.1 MeV, holding its charge to 0.1 nC/bunch. In the next test run, we prepared a deformable mirror for spatial shaping, and a spatial light modulator based on fused-silica plates for temporal shaping. We applied the both adaptive optics to automatically shape the bot...

  20. Fast adaptive OFDM-PON over single fiber loopback transmission using dynamic rate adaptation-based algorithm for channel performance improvement

    Science.gov (United States)

    Kartiwa, Iwa; Jung, Sang-Min; Hong, Moon-Ki; Han, Sang-Kook

    2014-03-01

    In this paper, we propose a novel fast adaptive approach that was applied to an OFDM-PON 20-km single fiber loopback transmission system to improve channel performance in term of stabilized BER below 2 × 10-3 and higher throughput beyond 10 Gb/s. The upstream transmission is performed through light source-seeded modulation using 1-GHz RSOA at the ONU. Experimental results indicated that the dynamic rate adaptation algorithm based on greedy Levin-Campello could be an effective solution to mitigate channel instability and data rate degradation caused by the Rayleigh back scattering effect and inefficient resource subcarrier allocation.

  1. Study on Adaptive Slid Mode Controller for Improving Handling Stability of Motorized Electric Vehicles

    Directory of Open Access Journals (Sweden)

    LiQiang Jin

    2014-01-01

    Full Text Available An adaptive slid mode controller was established for improving the handling stability of motorized electric vehicle (MEV. First and foremost, the structure and advantages of electric vehicle driven by in-wheel motors will be provided. Then, an ideal cornering model of vehicles will be brought and analyzed, after which a method to estimate side-slip angle was also proposed and three typical sensors were used in the theory. Besides, an idea for the recognition of road adhesion coefficient was derived based on MEV platform, which will be helpful for better control performances. Finally, the scheme of control method was given and some typical tests for observing handling properties were implemented based on Simulink and Carsim software. With the outcomes from the experiments, which vividly showed the merits of the controller, one can come to a conclusion that MEV that equips with the adaptive slid mode controller always enjoys better handling performances than the one without control. Furthermore, the controller researched is friendly to the real-time working conditions, which will hold practical values in the future.

  2. A Time Efficient Adaptive Gridding Approach and Improved Calibrations in Five-Hole Probe Measurements

    Directory of Open Access Journals (Sweden)

    Jason Town

    2015-01-01

    Full Text Available Five-Hole Probes (FHP, being a dependable and accurate aerodynamic tool, are an excellent choice for measuring three-dimensional flow fields in turbomachinery. To improve spatial resolution, a subminiature FHP with a diameter of 1.68 mm is employed. High length to diameter ratio of the tubing and manual pitch and yaw calibration cause increased uncertainty. A new FHP calibrator is designed and built to reduce the uncertainty by precise, computer controlled movements and reduced calibration time. The calibrated FHP is then placed downstream of the nozzle guide vane (NGV assembly of a low-speed, large-scale, axial flow turbine. The cold flow HP turbine stage contains 29 vanes and 36 blades. A fast and computer controllable traversing system is implemented using an adaptive grid method for the refinement of measurements in regions such as vane wake, secondary flows, and boundary layers. The current approach increases the possible number of measurement points in a two-hour period by 160%. Flow structures behind the NGV measurement plane are identified with high spatial resolution and reduced uncertainty. The automated pitch and yaw calibration and the adaptive grid approach introduced in this study are shown to be a highly effective way of measuring complex flow fields in the research turbine.

  3. Improving time domain fluorescence lifetime imaging with an adaptive Monte Carlo data inflation (AMDI) algorithm

    Science.gov (United States)

    Leray, Aymeric; Trinel, Dave; Spriet, Corentin; Usson, Yves; Heliot, Laurent

    2011-07-01

    Fluorescence Lifetime Imaging Microscopy (FLIM) is a powerful technique which gives access to the local environment of fluorophores in living cells. However, to correctly estimate all lifetime parameters, time domain FLIM imaging requires a high number of photons and consequently a long laser exposure time which is not compatible with the observation of dynamic molecular events and which induces cellular stress phenomena. For reducing this exposure time, we have developed an original approach to statistically inflate the number of collected photon. This approach called Adaptive Monte Carlo Data Inflation (AMDI) combines the well-known bootstrap technique with an adaptive Parzen kernel. We have evaluated its potential on experimental FLIM data in vivo. We have demonstrated that our robust method allows estimating precisely fluorescence lifetime with exposure time reduced up to 50 times for mono-exponential (corresponding to a minimum of 20 photons/pixel) and 10 times for bi-exponential decays (corresponding to a minimum of 5000 photons/pixel) in comparison with the standard fitting method. Furthermore, thanks to AMDI, we demonstrate that it becomes possible to estimate accurately all fitting parameters in FRET experiments without constraining any parameter. An additional benefit of our technique is that it improves the spatial resolution of the FLIM images by reducing the commonly used spatial binning factor.

  4. Quantifying the adaptive cycle

    Science.gov (United States)

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

  5. Physical exercise leads to rapid adaptations in hippocampal vasculature: temporal dynamics and relationship to cell proliferation and neurogenesis.

    Science.gov (United States)

    Van der Borght, Karin; Kóbor-Nyakas, Dóra E; Klauke, Karin; Eggen, Bart J L; Nyakas, Csaba; Van der Zee, Eddy A; Meerlo, Peter

    2009-10-01

    Increased levels of angiogenesis and neurogenesis possibly mediate the beneficial effects of physical activity on hippocampal plasticity. This study was designed to investigate the temporal dynamics of exercise-induced changes in hippocampal angiogenesis and cell proliferation. Mice were housed with a running wheel for 1, 3, or 10 days. Analysis of glucose transporter Glut1-positive vessel density showed a significant increase after 3 days of wheel running. Cell proliferation in the dentate gyrus showed a trend towards an increase after 3 days of running and was significantly elevated after 10 days of physical exercise. Ten days of wheel running resulted in a near-significant increase in the number of immature neurons, as determined by a doublecortin (DCX) staining. In the second part of the study, the persistence of the exercise-induced changes in angiogenesis and cell proliferation was determined. The running wheel was removed from the cage after 10 days of physical activity. Glut-1 positive vessel density and hippocampal cell proliferation were determined 1 and 6 days after removal of the wheel. Both parameters had returned to baseline 24 h after cessation of physical activity. The near-significant increase in the number of DCX-positive immature neurons persisted for at least 6 days, indicating that new neurons formed during the period of increased physical activity had survived. Together these experiments show that the hippocampus displays a remarkable angiogenic and neurogenic plasticity and rapidly responds to changes in physical activity.

  6. Improved Estimation of Earth Rotation Parameters Using the Adaptive Ridge Regression

    Science.gov (United States)

    Huang, Chengli; Jin, Wenjing

    1998-05-01

    The multicollinearity among regression variables is a common phenomenon in the reduction of astronomical data. The phenomenon of multicollinearity and the diagnostic factors are introduced first. As a remedy, a new method, called adaptive ridge regression (ARR), which is an improved method of choosing the departure constant θ in ridge regression, is suggested and applied in a case that the Earth orientation parameters (EOP) are determined by lunar laser ranging (LLR). It is pointed out, via a diagnosis, the variance inflation factors (VIFs), that there exists serious multicollinearity among the regression variables. It is shown that the ARR method is effective in reducing the multicollinearity and makes the regression coefficients more stable than that of using ordinary least squares estimation (LS), especially when there is serious multicollinearity.

  7. Improved optimal steering law for SGCMG and adaptive attitude control of flexible spacecraft

    Institute of Scientific and Technical Information of China (English)

    Lu Wang; Yu Guo; Liping Wu; Qingwei Chen

    2015-01-01

    The issue of attitude maneuver of a flexible spacecraft is investigated with single gimbaled control moment gyroscopes (SGCMGs) as an actuator. To solve the inertia uncertainty of the system, an adaptive attitude control algorithm is designed by ap-plying a radial basis function (RBF) neural network. An improved steering law for SGCMGs is proposed to achieve the optimal out-put torque. It enables the SGCMGs not only to avoid singularity, but also to output more precise torque. In addition, global, uniform, ultimate bounded stability of the attitude control system is proved via the Lyapunov technique. Simulation results demonstrate the effectiveness of the new steering law and the algorithm of attitude maneuver of the flexible spacecraft.

  8. Pairwise adaptive thermostats for improved accuracy and stability in dissipative particle dynamics

    CERN Document Server

    Leimkuhler, Benedict

    2016-01-01

    We examine the formulation and numerical treatment of dissipative particle dynamics (DPD) and momentum-conserving molecular dynamics. We show that it is possible to improve both the accuracy and the stability of DPD by employing a pairwise adaptive Langevin thermostat that precisely matches the dynamical characteristics of DPD simulations (e.g., autocorrelation functions) while automatically correcting thermodynamic averages using a negative feedback loop. In the low friction regime, it is possible to replace DPD by a simpler momentum-conserving variant of the Nos\\'{e}--Hoover--Langevin method based on thermostatting only pairwise interactions; we show that this method has an extra order of accuracy for an important class of observables (a superconvergence result), while also allowing larger timesteps than alternatives. All the methods mentioned in the article are easily implemented. Numerical experiments are performed in both equilibrium and nonequilibrium settings; using Lees--Edwards boundary conditions to...

  9. Glucagon-like peptide 2 treatment may improve intestinal adaptation during weaning

    DEFF Research Database (Denmark)

    Thymann, Thomas; Le Huërou-Luron, I; Petersen, Y M;

    2014-01-01

    Transition from sow’s milk to solid feed is associated with intestinal atrophy and diarrhea. We hypothesized that the intestinotrophic hormone glucagon-like peptide 2 (GLP-2) would induce a dose- and health status-dependent effect on gut adaptation. In Exp. 1, weaned pigs (average BW at weaning 4.......98 ± 0.18 kg) were kept in a high-sanitary environment and injected with saline or short-acting GLP-2 (80 μg/(kg BW·12 h); n = 8). Under these conditions, there was no diarrhea and GLP-2 did not improve gastrointestinal structure or function. In Exp. 2, weaned pigs (average BW at weaning 6.68 ± 0.27 kg......) were kept in a low-sanitary environment, leading to weaning diarrhea, and injected with saline or short-acting GLP-2 (200 µg/(kg BW·12 h); n = 11). Treatment with GLP-2 increased goblet cell density (P

  10. Joint-Angle Specific Strength Adaptations Influence Improvements in Power in Highly Trained Athletes

    Directory of Open Access Journals (Sweden)

    Rhea Matthew R.

    2016-03-01

    Full Text Available Purpose. The purpose of this study was to examine the influence of training at different ranges of motion during the squat exercise on joint-angle specific strength adaptations. Methods. Twenty eight men were randomly assigned to one of three training groups, differing only in the depth of squats (quarter squat, half squat, and full squat performed in 16-week training intervention. Strength measures were conducted in the back squat pre-, mid-, and post-training at all three depths. Vertical jump and 40-yard sprint time were also measured. Results. Individuals in the quarter and full squat training groups improved significantly more at the specific depth at which they trained when compared to the other two groups (p < 0.05. Jump height and sprint speed improved in all groups (p < 0.05; however, the quarter squat had the greatest transfer to both outcomes. Conclusions. Consistently including quarter squats in workouts aimed at maximizing speed and jumping power can result in greater improvements.

  11. Improving the spatio-temporal erodibility of dust emission models using MODIS data (Invited)

    Science.gov (United States)

    Chappell, A.

    2013-12-01

    / reduce this waveband dependency. The Moderate Resolution Imaging Spectroradiometer (MODIS) includes a bi-directional reflectance model of surface roughness which enables a local solar noon ωdir product. We show how normalising this product is equivalent to the ray-traced estimates. We use MODIS data with Nω to estimate λ and Rt across Australia. We describe the information content of these new estimates using several spatial and temporal scales at various locations around Australia prone to wind erosion and dust emission

  12. Autophagy is required for exercise training-induced skeletal muscle adaptation and improvement of physical performance.

    Science.gov (United States)

    Lira, Vitor A; Okutsu, Mitsuharu; Zhang, Mei; Greene, Nicholas P; Laker, Rhianna C; Breen, David S; Hoehn, Kyle L; Yan, Zhen

    2013-10-01

    Pathological and physiological stimuli, including acute exercise, activate autophagy; however, it is unknown whether exercise training alters basal levels of autophagy and whether autophagy is required for skeletal muscle adaptation to training. We observed greater autophagy flux (i.e., a combination of increased LC3-II/LC3-I ratio and LC3-II levels and reduced p62 protein content indicating a higher rate of initiation and resolution of autophagic events), autophagy protein expression (i.e., Atg6/Beclin1, Atg7, and Atg8/LC3) and mitophagy protein Bnip3 expression in tonic, oxidative muscle compared to muscles of either mixed fiber types or of predominant glycolytic fibers in mice. Long-term voluntary running (4 wk) resulted in increased basal autophagy flux and expression of autophagy proteins and Bnip3 in parallel to mitochondrial biogenesis in plantaris muscle with mixed fiber types. Conversely, exercise training promoted autophagy protein expression with no significant increases of autophagy flux and mitochondrial biogenesis in the oxidative soleus muscle. We also observed increased basal autophagy flux and Bnip3 content without increases in autophagy protein expression in the plantaris muscle of sedentary muscle-specific Pgc-1α transgenic mice, a genetic model of augmented mitochondrial biogenesis. These findings reveal that endurance exercise training-induced increases in basal autophagy, including mitophagy, only take place if an enhanced oxidative phenotype is achieved. However, autophagy protein expression is mainly dictated by contractile activity independently of enhancements in oxidative phenotype. Exercise-trained mice heterozygous for the critical autophagy protein Atg6 showed attenuated increases of basal autophagy flux, mitochondrial content, and angiogenesis in skeletal muscle, along with impaired improvement of endurance capacity. These results demonstrate that increased basal autophagy is required for endurance exercise training-induced skeletal

  13. Adapting the iSNOBAL model for improved visualization in a GIS environment

    Science.gov (United States)

    Johansen, W. J.; Delparte, D.

    2014-12-01

    Snowmelt is a primary means of crucial water resources in much of the western United States. Researchers are developing models that estimate snowmelt to aid in water resource management. One such model is the image snowcover energy and mass balance (iSNOBAL) model. It uses input climate grids to simulate the development and melting of snowpack in mountainous regions. This study looks at applying this model to the Reynolds Creek Experimental Watershed in southwestern Idaho, utilizing novel approaches incorporating geographic information systems (GIS). To improve visualization of the iSNOBAL model, we have adapted it to run in a GIS environment. This type of environment is suited to both the input grid creation and the visualization of results. The data used for input grid creation can be stored locally or on a web-server. Kriging interpolation embedded within Python scripts are used to create air temperature, soil temperature, humidity, and precipitation grids, while built-in GIS and existing tools are used to create solar radiation and wind grids. Additional Python scripting is then used to perform model calculations. The final product is a user-friendly and accessible version of the iSNOBAL model, including the ability to easily visualize and interact with model results, all within a web- or desktop-based GIS environment. This environment allows for interactive manipulation of model parameters and visualization of the resulting input grids for the model calculations. Future work is moving towards adapting the model further for use in a 3D gaming engine for improved visualization and interaction.

  14. Improving adaptive optical systems by the use of multiple laser beacon configurations

    Science.gov (United States)

    de La Rue, Imelda Atencio

    The field of adaptive optics (AO) and laser-beacon AO has been successfully implemented in the last part of the 20th century. Adaptive optics greatly improves the resolution capabilities of ground-based telescopes by correcting for atmospheric turbulence. The initial implementation of laser-beacon AO was done on relatively small telescopes, on the order of 1.5 m. However, with larger aperture telescopes being built, such as the 8-m class Gemini telescopes, there is much room for improvement. Errors resulting from laser-beacon AO, such as focus anisoplanatism, become worse with an increase in aperture diameter. Tilt anisoplanatism is also a problem, regardless of the size of telescope, and also needs to be reduced to enhance the resolution of the objects being observed. This dissertation investigates alternate laser-beacon AO configurations, to reduce the effects of focus and tilt anisoplanatism for larger aperture telescopes. The configurations investigated include single and multiple laser beacons at single altitudes and single and multiple laser beacons at multiple altitudes. These second configurations are referred to as hybrid beacon systems and consist of Rayleigh beacons at altitudes of 10 to 20˜km and sodium beacons at about 90˜km, the location of the sodium layer. Hybrid systems are shown to reduce both focus and tilt anisoplanatism as opposed to the first configurations which only aid in reducing focus anisoplanatism. An addition to the hybrid systems with multiple beacons, the use of multiple deformable mirrors (DM's) is investigated. These additional DM's are placed conjugate to atmospheric altitudes with predominant turbulence, beyond the traditional conjugate location of the primary mirror. They correct for turbulence at these atmospheric layers and are referred to as multi-conjugate adaptive optical (MCAO) systems. The purpose of MCAO configurations is to increase the corrected field of view. For the types of systems investigated in this

  15. Spatio-temporal complexity of chimpanzee food: How cognitive adaptations can counteract the ephemeral nature of ripe fruit.

    Science.gov (United States)

    Janmaat, Karline R L; Boesch, Christophe; Byrne, Richard; Chapman, Colin A; Goné Bi, Zoro B; Head, Josephine S; Robbins, Martha M; Wrangham, Richard W; Polansky, Leo

    2016-06-01

    Ecological complexity has been proposed to play a crucial role in primate brain-size evolution. However, detailed quantification of ecological complexity is still limited. Here we assess the spatio-temporal distribution of tropical fruits and young leaves, two primary chimpanzee (Pan troglodytes) foods, focusing on the predictability of their availability in individual trees. Using up to 20 years of information on monthly availability of young leaf, unripe and ripe fruit in plant species consumed by chimpanzees from tropical forests in East, Central, and West Africa, we estimated: (1) the forest-wide frequency of occurrence of each food type and (2) the predictability of finding ripe fruit-bearing trees, focusing on the timing, frequency, and amount of ripe fruit present. In all three forests, at least half of all encountered trees belonged to species that chimpanzees were known to feed on. However, the proportion of these trees bearing young leaves and fruit fluctuated widely between months. Ripe fruit was the most ephemeral food source, and trees that had more than half of their crown filled were at least nine times scarcer than other trees. In old growth forests only one large ripe fruit crop was on average encountered per 10 km. High levels of inter-individual variation in the number of months that fruit was present existed, and in some extreme cases individuals bore ripe fruit more than seven times as often as conspecifics. Some species showed substantially less variation in such ripe fruit production frequencies and fruit quantity than others. We hypothesize that chimpanzees employ a suite of cognitive mechanisms, including abilities to: (1) generalize or classify food trees; (2) remember the relative metrics of quantity and frequency of fruit production across years; and (3) flexibly plan return times to feeding trees to optimize high-energy food consumption in individual trees, and efficient travel between them. Am. J. Primatol. 78:626-645, 2016. © 2016

  16. The Effect of Adaptive Gain and Adaptive Momentum in Improving Training Time of Gradient Descent Back Propagation Algorithm on Classification Problems

    Directory of Open Access Journals (Sweden)

    Norhamreeza Abdul Hamid

    2011-01-01

    Full Text Available The back propagation algorithm has been successfully applied to wide range of practical problems. Since this algorithm uses a gradient descent method, it has some limitations which are slow learning convergence velocity and easy convergence to local minima. The convergence behaviour of the back propagation algorithm depends on the choice of initial weights and biases, network topology, learning rate, momentum, activation function and value for the gain in the activation function. Previous researchers demonstrated that in ‘feed forward’ algorithm, the slope of the activation function is directly influenced by a parameter referred to as ‘gain’. This research proposed an algorithm for improving the performance of the current working back propagation algorithm which is Gradien Descent Method with Adaptive Gain by changing the momentum coefficient adaptively for each node. The influence of the adaptive momentum together with adaptive gain on the learning ability of a neural network is analysed. Multilayer feed forward neural networks have been assessed. Physical interpretation of the relationship between the momentum value, the learning rate and weight values is given. The efficiency of the proposed algorithm is compared with conventional Gradient Descent Method and current Gradient Descent Method with Adaptive Gain was verified by means of simulation on three benchmark problems. In learning the patterns, the simulations result demonstrate that the proposed algorithm converged faster on Wisconsin breast cancer with an improvement ratio of nearly 1.8, 6.6 on Mushroom problem and 36% better on  Soybean data sets. The results clearly show that the proposed algorithm significantly improves the learning speed of the current gradient descent back-propagatin algorithm.

  17. Shaping prestimulus neural activity with auditory rhythmic stimulation improves the temporal allocation of attention

    Science.gov (United States)

    Pincham, Hannah L.; Cristoforetti, Giulia; Facoetti, Andrea; Szűcs, Dénes

    2016-01-01

    Human attention fluctuates across time, and even when stimuli have identical physical characteristics and the task demands are the same, relevant information is sometimes consciously perceived and at other times not. A typical example of this phenomenon is the attentional blink, where participants show a robust deficit in reporting the second of two targets (T2) in a rapid serial visual presentation (RSVP) stream. Previous electroencephalographical (EEG) studies showed that neural correlates of correct T2 report are not limited to the RSVP period, but extend before visual stimulation begins. In particular, reduced oscillatory neural activity in the alpha band (8-12 Hz) before the onset of the RSVP has been linked to lower T2 accuracy. We therefore examined whether auditory rhythmic stimuli presented at a rate of 10 Hz (within the alpha band) could increase oscillatory alpha-band activity and improve T2 performance in the attentional blink time window. Behaviourally, the auditory rhythmic stimulation worked to enhance T2 accuracy. This enhanced perception was associated with increases in the posterior T2-evoked N2 component of the event-related potentials and this effect was observed selectively at lag 3. Frontal and posterior oscillatory alpha-band activity was also enhanced during auditory stimulation in the pre-RSVP period and positively correlated with T2 accuracy. These findings suggest that ongoing fluctuations can be shaped by sensorial events to improve the allocation of attention in time. PMID:26986506

  18. Improving Temporal Coverage of an Energy-Efficient Data Extraction Algorithm for Environmental Monitoring Using Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Supriyo Chatterjea

    2009-06-01

    Full Text Available Collecting raw data from a wireless sensor network for environmental monitoring applications can be a difficult task due to the high energy consumption involved. This is especially difficult when the application requires specialized sensors that have very high energy consumption, e.g. hydrological sensors for monitoring marine environments. This paper introduces a technique for reducing energy consumption by minimizing sensor sampling operations. In addition, we illustrate how a randomized algorithm can be used to improve temporal coverage such that the time between the occurrence of an event and its detection can be minimized. We evaluate our approach using real data collected from a sensor network deployment on the Great Barrier Reef.

  19. Using spatial, temporal and evidence-status data to improve ballistic imaging performance.

    Science.gov (United States)

    Yang, Yan; Koffman, Avi; Hocherman, Gil; Wein, Lawrence M

    2014-01-01

    Firearms identification imaging systems help solve crimes by comparing newly acquired images of cartridge casings or bullets to a database of images obtained from past crime scenes. We formulate an optimization problem that bases its matching decisions not only on the similarity between pairs of images, but also on the time and spatial location of each new acquisition and each database entry. The objective is to maximize the detection probability subject to a constraint on the false positive rate. We use data on all cartridge casings matches detected in Israel during 2006-2008 to estimate most of the model parameters. We estimate matching accuracy from two different studies and predict that the optimal use of extraneous information would increase the detection probability from 0.931 to 0.987 and from 0.707 to 0.844, respectively. These improvements are achieved by favoring pairs of images that are closer together in space and time. PMID:24400829

  20. Using spatial, temporal and evidence-status data to improve ballistic imaging performance.

    Science.gov (United States)

    Yang, Yan; Koffman, Avi; Hocherman, Gil; Wein, Lawrence M

    2014-01-01

    Firearms identification imaging systems help solve crimes by comparing newly acquired images of cartridge casings or bullets to a database of images obtained from past crime scenes. We formulate an optimization problem that bases its matching decisions not only on the similarity between pairs of images, but also on the time and spatial location of each new acquisition and each database entry. The objective is to maximize the detection probability subject to a constraint on the false positive rate. We use data on all cartridge casings matches detected in Israel during 2006-2008 to estimate most of the model parameters. We estimate matching accuracy from two different studies and predict that the optimal use of extraneous information would increase the detection probability from 0.931 to 0.987 and from 0.707 to 0.844, respectively. These improvements are achieved by favoring pairs of images that are closer together in space and time.

  1. Coping with spatial heterogeneity and temporal variability in resources and risks: adaptive movement behaviour by a large grazing herbivore.

    Directory of Open Access Journals (Sweden)

    Jodie Martin

    Full Text Available Movement is a key mean for mobile species to cope with heterogeneous environments. While in herbivorous mammals large-scale migration has been widely investigated, fine-scale movement responses to local variations in resources and predation risk remain much less studied, especially in savannah environments. We developed a novel approach based on complementary movement metrics (residence time, frequency of visits and regularity of visits to relate movement patterns of a savannah grazer, the blue wildebeest Connochaetes taurinus, to fine-scale variations in food availability, predation risk and water availability in the Kruger National Park, South Africa. Wildebeests spent more time in grazing lawns where the grass is of higher quality but shorter than in seep zones, where the grass is of lower quality but more abundant. Although the daily distances moved were longer during the wet season compared to the dry season, the daily net displacement was lower, and the residence time higher, indicating a more frequent occurrence of area-concentred searching. In contrast, during the late dry season the foraging sessions were more fragmented and wildebeests moved more frequently between foraging areas. Surprisingly, predation risk appeared to be the second factor, after water availability, influencing movement during the dry season, when resources are limiting and thus expected to influence movement more. Our approach, using complementary analyses of different movement metrics, provided an integrated view of changes in individual movement with varying environmental conditions and predation risk. It makes it possible to highlight the adaptive behavioral decisions made by wildebeest to cope with unpredictable environmental variations and provides insights for population conservation.

  2. Adaptive Wavelet Threshold Denoising Method for Machinery Sound Based on Improved Fruit Fly Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Jing Xu

    2016-07-01

    Full Text Available As the sound signal of a machine contains abundant information and is easy to measure, acoustic-based monitoring or diagnosis systems exhibit obvious superiority, especially in some extreme conditions. However, the sound directly collected from industrial field is always polluted. In order to eliminate noise components from machinery sound, a wavelet threshold denoising method optimized by an improved fruit fly optimization algorithm (WTD-IFOA is proposed in this paper. The sound is firstly decomposed by wavelet transform (WT to obtain coefficients of each level. As the wavelet threshold functions proposed by Donoho were discontinuous, many modified functions with continuous first and second order derivative were presented to realize adaptively denoising. However, the function-based denoising process is time-consuming and it is difficult to find optimal thresholds. To overcome these problems, fruit fly optimization algorithm (FOA was introduced to the process. Moreover, to avoid falling into local extremes, an improved fly distance range obeying normal distribution was proposed on the basis of original FOA. Then, sound signal of a motor was recorded in a soundproof laboratory, and Gauss white noise was added into the signal. The simulation results illustrated the effectiveness and superiority of the proposed approach by a comprehensive comparison among five typical methods. Finally, an industrial application on a shearer in coal mining working face was performed to demonstrate the practical effect.

  3. Adaptive management for improving species conservation across the captive-wild spectrum

    Science.gov (United States)

    Canessa, Stefano; Guillera-Arroita, Gurutzeta; Lahoz-Monfort, José J.; Southwell, Darren M; Armstrong, Doug P.; Chadès, Iadine; Lacy, Robert C; Converse, Sarah J.

    2016-01-01

    Conservation of endangered species increasingly envisages complex strategies that integrate captive and wild management actions. Management decisions in this context must be made in the face of uncertainty, often with limited capacity to collect information. Adaptive management (AM) combines management and monitoring, with the aim of updating knowledge and improving decision-making over time. We provide a guide for managers who may realize the potential of AM, but are unsure where to start. The urgent need for iterative management decisions, the existence of uncertainty, and the opportunity for learning offered by often highly-controlled captive environments create favorable conditions for AM. However, experiments and monitoring may be complicated by small sample sizes, and the ability to control the system, including stochasticity and observability, may be limited toward the wild end of the spectrum. We illustrate the key steps to implementing AM in threatened species management using four case studies, including the management of captive programs for cheetah (Acinonyx jubatus) and whooping cranes (Grus americana), of a translocation protocol for Arizona cliffroses Purshia subintegra and of ongoing supplementary feeding of reintroduced hihi (Notiomystis cincta) populations. For each case study, we explain (1) how to clarify whether the decision can be improved by learning (i.e. it is iterative and complicated by uncertainty) and what the management objectives are; (2) how to articulate uncertainty via alternative, testable hypotheses such as competing models or parameter distributions; (3) how to formally define how additional information can be collected and incorporated in future management decisions.

  4. Spatial-temporal distribution of a Noctiluca scintillans population and its adaption to environmental conditions in northern South China Sea

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2012-11-01

    Full Text Available Based on the data of a Noctiluca scintillans population in northern South China Sea (107°00′–119°00′E, 16°00′–24°00′N obtained in project “Integrated Investigation and Assessment of China Seas”(coded as 908 project in 2006 and 2008, we described the spatial distribution in wide geographical areas and seasonal variations of a Noctiluca scintillans population using GIS spatial analysis modeling and mapping techniques. The adaption of Noctiluca scintillans to temperature, salinity and nutrients were also discussed. The results showed that abundance of Noctiluca scintillans varied from 0.001×104 cells/m3 to 64.5×104 cells/m3, with an average of (0.56±3.29×104 cells/m3(n = 1,424. Average abundance varied by season, spring > autumn > winter > summer, with highest and lowest abundances of (1.28±4.24×104 cells/m3 (n = 356 and (0.19±0.95×104 cells/m3 (n = 356, respectively. The spatial distribution of Noctiluca scintillans generally decreased from alongshore to offshore areas, in a pattern of discontinuous patches. Abundance assemblage zones laid along the shores of eastern Leizhou peninsula, where it was also the peak abundance region in winter. The zones of low annunal abundance were primarily in the northern South China Sea. Dapeng Bay in eastern Guangdong Province and Pearl River Estuary were not abundance assemblage zones during summer and winter months. We found the shore of southeastern Hainan Island became high abundance zones during summer months. Compared with data of national integrated investigations completed in 1958 and 1959, Noctiluca scintillans abundance increased abruptly with an evident change of abundance assemblage zones. The seasonal variation was obvious. Average Noctiluca scintillans abundance was 27 times higher than recorded in 1959. Noctiluca scintillans populations in South China Sea required a much higher temperature than it did in East, Yellow and Bohai Seas in China. Salinity fluctuations were

  5. Face adaptation does not improve performance on search or discrimination tasks.

    Science.gov (United States)

    Ng, Minna; Boynton, Geoffrey M; Fine, Ione

    2008-01-04

    The face adaptation effect, as described by M. A. Webster and O. H. MacLin (1999), is a robust perceptual shift in the appearance of faces after a brief adaptation period. For example, prolonged exposure to Asian faces causes a Eurasian face to appear distinctly Caucasian. This adaptation effect has been documented for general configural effects, as well as for the facial properties of gender, ethnicity, expression, and identity. We began by replicating the finding that adaptation to ethnicity, gender, and a combination of both features induces selective shifts in category appearance. We then investigated whether this adaptation has perceptual consequences beyond a shift in the perceived category boundary by measuring the effects of adaptation on RSVP, spatial search, and discrimination tasks. Adaptation had no discernable effect on performance for any of these tasks.

  6. TCP- Costco Reno: New Variant by Improving Bandwidth Estimation to adapt over MANETs

    Directory of Open Access Journals (Sweden)

    Prakash B. Khelage

    2014-01-01

    Full Text Available The Transmission Control Protocol (TCP is traditional, dominant and has been de facto standard protocol, used as transport agent at transport layer of TCP/IP protocol suite. Basically it is designed to provide reliability and assure guaranty to end-to-end delivery of data over unreliable networks. In practice, most TCP deployments have been carefully designed in the context of wired networks. Ignoring the properties of wireless Ad Hoc Networks, therefore it can lead to TCP implementations with poor performance. The problem of TCP and all its existing variations within MANETs resides in its inability to distinguish between different data packet loss causes, whenever the data loss occur traditional TCP congestion control algorithm assumes loss is due to congestion episode and reduces sending parameters value unnecessary. Thus, TCP has not always the optimum behavior in front of packet losses which might cause network performance degradation and resources waste. In order to adapt TCP over mobile Ad hoc environment, improvements have been proposed based on RTT and BW estimation technique in the literature to help TCP to differentiate accurate causes between the different types of losses. But still does not handle all the problems accurately and effectively. In this paper, a proposed TCP-Costco Reno a New Variant, accurately estimates the available bandwidth over Mobile Ad Hoc networks and sets sending rate accordingly to maximize utilization of available resources and hence improves performance of TCP over mobile Ad hoc networks. The results of the simulation indicate an improvement in throughput over interference, link failure and signal loss validation scenarios. Further, it shows highest average of average throughput then those variants which are most successful over MANETs.

  7. Investigation of instabilities affecting detonations: Improving the resolution using block-structured adaptive mesh refinement

    Science.gov (United States)

    Ravindran, Prashaanth

    The unstable nature of detonation waves is a result of the critical relationship between the hydrodynamic shock and the chemical reactions sustaining the shock. A perturbative analysis of the critical point is quite challenging due to the multiple spatio-temporal scales involved along with the non-linear nature of the shock-reaction mechanism. The author's research attempts to provide detailed resolution of the instabilities at the shock front. Another key aspect of the present research is to develop an understanding of the causality between the non-linear dynamics of the front and the eventual breakdown of the sub-structures. An accurate numerical simulation of detonation waves requires a very efficient solution of the Euler equations in conservation form with detailed, non-equilibrium chemistry. The difference in the flow and reaction length scales results in very stiff source terms, requiring the problem to be solved with adaptive mesh refinement. For this purpose, Berger-Colella's block-structured adaptive mesh refinement (AMR) strategy has been developed and applied to time-explicit finite volume methods. The block-structured technique uses a hierarchy of parent-child sub-grids, integrated recursively over time. One novel approach to partition the problem within a large supercomputer was the use of modified Peano-Hilbert space filling curves. The AMR framework was merged with CLAWPACK, a package providing finite volume numerical methods tailored for wave-propagation problems. The stiffness problem is bypassed by using a 1st order Godunov or a 2nd order Strang splitting technique, where the flow variables and source terms are integrated independently. A linearly explicit fourth-order Runge-Kutta integrator is used for the flow, and an ODE solver was used to overcome the numerical stiffness. Second-order spatial resolution is obtained by using a second-order Roe-HLL scheme with the inclusion of numerical viscosity to stabilize the solution near the discontinuity

  8. Improving conservation outcomes with a new paradigm for understanding species’ fundamental and realized adaptive capacity

    Science.gov (United States)

    Beever, Erik; O’Leary, John; Mengelt, Claudia; West, Jordan M.; Julius, Susan; Green, Nancy; Magness, Dawn; Petes, Laura E.; Stein, Bruce A.; Nicotra, Adrienne B; Hellmann, Jessica J; Robertson, Amanda L; Staudinger, Michelle D.; Rosenberg, Andrew A.; Babij, Eleanora; Brennan, Jean; Schuurman, Gregor W; Hofmann, Gretchen E

    2016-01-01

    Worldwide, many species are responding to ongoing climate change with shifts in distribution, abundance, phenology, or behavior. Consequently, natural-resource managers face increasingly urgent conservation questions related to biodiversity loss, expansion of invasive species, and deteriorating ecosystem services. We argue that our ability to address these questions is hampered by the lack of explicit consideration of species’ adaptive capacity (AC). AC is the ability of a species or population to cope with climatic changes and is characterized by three fundamental components: phenotypic plasticity, dispersal ability, and genetic diversity. However, few studies simultaneously address all elements; often, AC is confused with sensitivity or omitted altogether from climate-change vulnerability assessments. Improved understanding, consistent definition, and comprehensive evaluations of AC are needed. Using classic ecological-niche theory as an analogy, we propose a new paradigm that considers fundamental and realized AC: the former reflects aspects inherent to species, whereas the latter denotes how extrinsic factors constrain AC to what is actually expressed or observed. Through this conceptualization, we identify ecological attributes contributing to AC, outline areas of research necessary to advance understanding of AC, and provide examples demonstrating how the inclusion of AC can better inform conservation and natural-resource management.

  9. Aortic pressure wave reconstruction during exercise is improved by adaptive filtering: a pilot study.

    Science.gov (United States)

    Stok, Wim J; Westerhof, Berend E; Guelen, Ilja; Karemaker, John M

    2011-08-01

    Reconstruction of central aortic pressure from a peripheral measurement by a generalized transfer function (genTF) works well at rest and mild exercise at lower heart rates, but becomes less accurate during heavy exercise. Particularly, systolic and pulse pressure estimations deteriorate, thereby underestimating central pressure. We tested individualization of the TF (indTF) by adapting its resonance frequency at the various levels of exercise. In seven males (age 44-57) with coronary artery disease, central and peripheral pressures were measured simultaneously. The optimal resonance frequency was predicted from regression formulas using variables derived from the individual's peripheral pressure pulse, including a pulse contour estimation of cardiac output (pcCO). In addition, reconstructed pressures were calibrated to central mean and diastolic pressure at each exercise level. Using a genTF and without calibration, the error in estimated aortic pulse pressure was -7.5 ± 6.4 mmHg, which was reduced to 0.2 ± 5.7 mmHg with the indTFs using pcCO for prediction. Calibration resulted in less scatter at the cost of a small bias (2.7 mmHg). In exercise, the indTFs predict systolic and pulse pressure better than the genTF. This pilot study shows that it is possible to individualize the peripheral to aortic pressure transfer function, thereby improving accuracy in central blood pressure assessment during exercise. PMID:21720842

  10. IL-15 prevents apoptosis, reverses innate and adaptive immune dysfunction, and improves survival in sepsis.

    Science.gov (United States)

    Inoue, Shigeaki; Unsinger, Jacqueline; Davis, Christopher G; Muenzer, Jared T; Ferguson, Thomas A; Chang, Katherine; Osborne, Dale F; Clark, Andrew T; Coopersmith, Craig M; McDunn, Jonathan E; Hotchkiss, Richard S

    2010-02-01

    IL-15 is a pluripotent antiapoptotic cytokine that signals to cells of both the innate and adaptive immune system and is regarded as a highly promising immunomodulatory agent in cancer therapy. Sepsis is a lethal condition in which apoptosis-induced depletion of immune cells and subsequent immunosuppression are thought to contribute to morbidity and mortality. This study tested the ability of IL-15 to block apoptosis, prevent immunosuppression, and improve survival in sepsis. Mice were made septic using cecal ligation and puncture or Pseudomonas aeruginosa pneumonia. The experiments comprised a 2 x 2 full factorial design with surgical sepsis versus sham and IL-15 versus vehicle. In addition to survival studies, splenic cellularity, canonical markers of activation and proliferation, intracellular pro- and antiapoptotic Bcl-2 family protein expression, and markers of immune cell apoptosis were evaluated by flow cytometry. Cytokine production was examined both in plasma of treated mice and splenocytes that were stimulated ex vivo. IL-15 blocked sepsis-induced apoptosis of NK cells, dendritic cells, and CD8 T cells. IL-15 also decreased sepsis-induced gut epithelial apoptosis. IL-15 therapy increased the abundance of antiapoptotic Bcl-2 while decreasing proapoptotic Bim and PUMA. IL-15 increased both circulating IFN-gamma, as well as the percentage of NK cells that produced IFN-gamma. Finally, IL-15 increased survival in both cecal ligation and puncture and P. aeruginosa pneumonia. In conclusion, IL-15 prevents two immunopathologic hallmarks of sepsis, namely, apoptosis and immunosuppression, and improves survival in two different models of sepsis. IL-15 represents a potentially novel therapy of this highly lethal disorder. PMID:20026737

  11. Improved characterization of slow-moving landslides by means of adaptive NL-InSAR filtering

    Science.gov (United States)

    Albiol, David; Iglesias, Rubén.; Sánchez, Francisco; Duro, Javier

    2014-10-01

    Advanced remote sensing techniques based on space-borne Synthetic Aperture Radar (SAR) have been developed during the last decade showing their applicability for the monitoring of surface displacements in landslide areas. This paper presents an advanced Persistent Scatterer Interferometry (PSI) processing based on the Stable Point Network (SPN) technique, developed by the company Altamira-Information, for the monitoring of an active slowmoving landslide in the mountainous environment of El Portalet, Central Spanish Pyrenees. For this purpose, two TerraSAR-X data sets acquired in ascending mode corresponding to the period from April to November 2011, and from August to November 2013, respectively, are employed. The objective of this work is twofold. On the one hand, the benefits of employing Nonlocal Interferomtric SAR (NL-InSAR) adaptive filtering techniques over vegetated scenarios to maximize the chances of detecting natural distributed scatterers, such as bare or rocky areas, and deterministic point-like scatterers, such as man-made structures or poles, is put forward. In this context, the final PSI displacement maps retrieved with the proposed filtering technique are compared in terms of pixels' density and quality with classical PSI, showing a significant improvement. On the other hand, since SAR systems are only sensitive to detect displacements in the line-of-sight (LOS) direction, the importance of projecting the PSI displacement results retrieved along the steepest gradient of the terrain slope is discussed. The improvements presented in this paper are particularly interesting in these type of applications since they clearly allow to better determine the extension and dynamics of complex landslide phenomena.

  12. Adaptive Light Modulation for Improved Resolution and Efficiency in All-Optical Pulse-Echo Ultrasound.

    Science.gov (United States)

    Alles, Erwin J; Colchester, Richard J; Desjardins, Adrien E

    2016-01-01

    In biomedical all-optical pulse-echo ultrasound systems, ultrasound is generated with the photoacoustic effect by illuminating an optically absorbing structure with a temporally modulated light source. Nanosecond range laser pulses are typically used, which can yield bandwidths exceeding 100 MHz. However, acoustical attenuation within tissue or nonuniformities in the detector or source power spectra result in energy loss at the affected frequencies and in a reduced overall system efficiency. In this work, a laser diode is used to generate linear and nonlinear chirp optical modulations that are extended to microsecond time scales, with bandwidths constrained to the system sensitivity. Compared to those obtained using a 2-ns pulsed laser, pulse-echo images of a phantom obtained using linear chirp excitation exhibit similar axial resolution (99 versus 92 μm, respectively) and signal-to-noise ratios (SNRs) (10.3 versus 9.6 dB). In addition, the axial point spread function (PSF) exhibits lower sidelobe levels in the case of chirp modulation. Using nonlinear (time-stretched) chirp excitations, where the nonlinearity is computed from measurements of the spectral sensitivity of the system, the power spectrum of the imaging system was flattened and its bandwidth broadened. Consequently, the PSF has a narrower axial extent and still lower sidelobe levels. Pulse-echo images acquired with time-stretched chirps as optical modulation have higher axial resolution (64 μm) than those obtained with linear chirps, at the expense of a lower SNR (6.8 dB). Using a linear or time-stretched chirp, the conversion efficiency from optical power to acoustical pressure improved by a factor of 70 or 61, respectively, compared to that obtained with pulsed excitation.

  13. IMPROVE THE KINETIC PERFORMANCE OF THE PUMP CONTROLLED CLAMPING UNIT IN PLASTIC INJECTION MOLDING MACHINE WITH ADAPTIVE CONTROL STRATEGY

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated.Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment. The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit.

  14. Placing prairie pothole wetlands along spatial and temporal continua to improve integration of wetland function in ecological investigations

    Science.gov (United States)

    Euliss, Ned H.; Mushet, David M.; Newton, Wesley E.; Otto, Clint R.V.; Nelson, Richard D.; LaBaugh, James W.; Scherff, Eric J.; Rosenberry, Donald O.

    2014-01-01

    We evaluated the efficacy of using chemical characteristics to rank wetland relation to surface and groundwater along a hydrologic continuum ranging from groundwater recharge to groundwater discharge. We used 27 years (1974–2002) of water chemistry data from 15 prairie pothole wetlands and known hydrologic connections of these wetlands to groundwater to evaluate spatial and temporal patterns in chemical characteristics that correspond to the unique ecosystem functions each wetland performed. Due to the mineral content and the low permeability rate of glacial till and soils, salinity of wetland waters increased along a continuum of wetland relation to groundwater recharge, flow-through or discharge. Mean inter-annual specific conductance (a proxy for salinity) increased along this continuum from wetlands that recharge groundwater being fresh to wetlands that receive groundwater discharge being the most saline, and wetlands that both recharge and discharge to groundwater (i.e., groundwater flow-through wetlands) being of intermediate salinity. The primary axis from a principal component analysis revealed that specific conductance (and major ions affecting conductance) explained 71% of the variation in wetland chemistry over the 27 years of this investigation. We found that long-term averages from this axis were useful to identify a wetland’s long-term relation to surface and groundwater. Yearly or seasonal measurements of specific conductance can be less definitive because of highly dynamic inter- and intra-annual climate cycles that affect water volumes and the interaction of groundwater and geologic materials, and thereby influence the chemical composition of wetland waters. The influence of wetland relation to surface and groundwater on water chemistry has application in many scientific disciplines and is especially needed to improve ecological understanding in wetland investigations. We suggest ways that monitoring in situ wetland conditions could be linked

  15. Improved compressed sensing-based cone-beam CT reconstruction using adaptive prior image constraints

    Science.gov (United States)

    Lee, Ho; Xing, Lei; Davidi, Ran; Li, Ruijiang; Qian, Jianguo; Lee, Rena

    2012-04-01

    Volumetric cone-beam CT (CBCT) images are acquired repeatedly during a course of radiation therapy and a natural question to ask is whether CBCT images obtained earlier in the process can be utilized as prior knowledge to reduce patient imaging dose in subsequent scans. The purpose of this work is to develop an adaptive prior image constrained compressed sensing (APICCS) method to solve this problem. Reconstructed images using full projections are taken on the first day of radiation therapy treatment and are used as prior images. The subsequent scans are acquired using a protocol of sparse projections. In the proposed APICCS algorithm, the prior images are utilized as an initial guess and are incorporated into the objective function in the compressed sensing (CS)-based iterative reconstruction process. Furthermore, the prior information is employed to detect any possible mismatched regions between the prior and current images for improved reconstruction. For this purpose, the prior images and the reconstructed images are classified into three anatomical regions: air, soft tissue and bone. Mismatched regions are identified by local differences of the corresponding groups in the two classified sets of images. A distance transformation is then introduced to convert the information into an adaptive voxel-dependent relaxation map. In constructing the relaxation map, the matched regions (unchanged anatomy) between the prior and current images are assigned with smaller weight values, which are translated into less influence on the CS iterative reconstruction process. On the other hand, the mismatched regions (changed anatomy) are associated with larger values and the regions are updated more by the new projection data, thus avoiding any possible adverse effects of prior images. The APICCS approach was systematically assessed by using patient data acquired under standard and low-dose protocols for qualitative and quantitative comparisons. The APICCS method provides an

  16. Improved Robust Adaptive Control of a Fluidized Bed Combustor for Sewage Sludge

    Institute of Scientific and Technical Information of China (English)

    MENGHong-Xia; JIAYing-Min

    2005-01-01

    This paper presents a robust model reference adaptive control scheme to deal with uncertain time delay in the dynamical model of a fluidized bed combustor for sewage sludge. The theoretical analysis and simulation results show that the proposed scheme can guarantee not only stability and robustness, but also the adaptive decoupling performance of the system.

  17. Adaptive Lockable Units to Improve Data Availability in a Distributed Database System

    Directory of Open Access Journals (Sweden)

    Khaled Maabreh

    2016-01-01

    Full Text Available Distributed database systems have become a phenomenon and have been considered a crucial source of information for numerous users. Users with different jobs are using such systems locally or via the Internet to meet their professional requirements. Distributed database systems consist of a number of sites connected over a computer network. Each site deals with its own database and interacts with other sites as needed. Data replication in these systems is considered a key factor in improving data availability. However, it may affect system performance when most of the transactions that access the data contain write or a mix of read and write operations because of exclusive locks and update propagation. This research proposes a new adaptive approach for increasing the availability of data contained in a distributed database system. The proposed approach suggests a new lockable unit by increasing the database hierarchy tree by one level to include attributes as lockable units instead of the entire row. This technique may allow several transactions to access the database row simultaneously by utilizing some attributes and keeping others available for other transactions. Data in a distributed database system can be accessed locally or remotely by a distributed transaction, with each distributed transaction decomposed into several sub-transactions called participants or agents. These agents access the data at multiple sites and must guarantee that any changes to the data must be committed in order to complete the main transaction. The experimental results show that using attribute-level locking will increase data availability, reliability, and throughput, as well as enhance overall system performance. Moreover, it will increase the overhead of managing such a large number of locks, which will be managed according to the qualification of the query.

  18. An Improved Method for Producing High Spatial-Resolution NDVI Time Series Datasets with Multi-Temporal MODIS NDVI Data and Landsat TM/ETM+ Images

    Directory of Open Access Journals (Sweden)

    Yuhan Rao

    2015-06-01

    Full Text Available Due to technical limitations, it is impossible to have high resolution in both spatial and temporal dimensions for current NDVI datasets. Therefore, several methods are developed to produce high resolution (spatial and temporal NDVI time-series datasets, which face some limitations including high computation loads and unreasonable assumptions. In this study, an unmixing-based method, NDVI Linear Mixing Growth Model (NDVI-LMGM, is proposed to achieve the goal of accurately and efficiently blending MODIS NDVI time-series data and multi-temporal Landsat TM/ETM+ images. This method firstly unmixes the NDVI temporal changes in MODIS time-series to different land cover types and then uses unmixed NDVI temporal changes to predict Landsat-like NDVI dataset. The test over a forest site shows high accuracy (average difference: −0.0070; average absolute difference: 0.0228; and average absolute relative difference: 4.02% and computation efficiency of NDVI-LMGM (31 seconds using a personal computer. Experiments over more complex landscape and long-term time-series demonstrated that NDVI-LMGM performs well in each stage of vegetation growing season and is robust in regions with contrasting spatial and spatial variations. Comparisons between NDVI-LMGM and current methods (i.e., Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM, Enhanced STARFM (ESTARFM and Weighted Linear Model (WLM show that NDVI-LMGM is more accurate and efficient than current methods. The proposed method will benefit land surface process research, which requires a dense NDVI time-series dataset with high spatial resolution.

  19. Assessing the components of adaptive capacity to improve conservation and management efforts under global change

    Science.gov (United States)

    Nicotra, Adrienne; Beever, Erik; Robertson, Amanda; Hofmann, Gretchen; O’Leary, John

    2015-01-01

    Natural-resource managers and other conservation practitioners are under unprecedented pressure to categorize and quantify the vulnerability of natural systems based on assessment of the exposure, sensitivity, and adaptive capacity of species to climate change. Despite the urgent need for these assessments, neither the theoretical basis of adaptive capacity nor the practical issues underlying its quantification has been articulated in a manner that is directly applicable to natural-resource management. Both are critical for researchers, managers, and other conservation practitioners to develop reliable strategies for assessing adaptive capacity. Drawing from principles of classical and contemporary research and examples from terrestrial, marine, plant, and animal systems, we examined broadly the theory behind the concept of adaptive capacity. We then considered how interdisciplinary, trait- and triage-based approaches encompassing the oft-overlooked interactions among components of adaptive capacity can be used to identify species and populations likely to have higher (or lower) adaptive capacity. We identified the challenges and value of such endeavors and argue for a concerted interdisciplinary research approach that combines ecology, ecological genetics, and eco-physiology to reflect the interacting components of adaptive capacity. We aimed to provide a basis for constructive discussion between natural-resource managers and researchers, discussions urgently needed to identify research directions that will deliver answers to real-world questions facing resource managers, other conservation practitioners, and policy makers. Directing research to both seek general patterns and identify ways to facilitate adaptive capacity of key species and populations within species, will enable conservation ecologists and resource managers to maximize returns on research and management investment and arrive at novel and dynamic management and policy decisions.

  20. Improved prediction error filters for adaptive feedback cancellation in hearing aids

    OpenAIRE

    Ngo, Kim; van Waterschoot, Toon; Christensen, Mads Græsbøll; Moonen, Marc; Jensen, Søren Holdt

    2013-01-01

    Acoustic feedback is a well-known problem in hearing aids, caused by the undesired acoustic coupling between the hearing aid loudspeaker and microphone. Acoustic feedback produces annoying howling sounds and limits the maximum achievable hearing aid amplification. This paper is focused on adaptive feedback cancellation (AFC) where the goal is to adaptively model the acoustic feedback path and estimate the feedback signal, which is then subtracted from the microphone signal. The main problem i...

  1. Incorporating Midbrain Adaptation to Mean Sound Level Improves Models of Auditory Cortical Processing

    OpenAIRE

    Harper, NS; Willmore, BDB; Schnupp, JWH; King, AJ; Schoppe, O

    2016-01-01

    Adaptation to stimulus statistics, such as the mean level and contrast of recently- heard sounds, has been demonstrated at various levels of the auditory pathway. It allows the nervous system to operate over the wide range of intensities and contrasts found in the natural world. Yet, current standard models of the response properties of auditory neurons do not incorporate such adaptation. Here, we present a model of neural responses in the ferret auditory cortex (the I...

  2. Rift Valley fever dynamics in Senegal: a project for pro-active adaptation and improvement of livestock raising management.

    Science.gov (United States)

    Lafaye, Murielle; Sall, Baba; Ndiaye, Youssou; Vignolles, Cecile; Tourre, Yves M; Borchi, Franc Ois; Soubeyroux, Jean-Michel; Diallo, Mawlouth; Dia, Ibrahima; Ba, Yamar; Faye, Abdoulaye; Ba, Taibou; Ka, Alioune; Ndione, Jacques-André; Gauthier, Hélène; Lacaux, Jean-Pierre

    2013-11-01

    The multi-disciplinary French project "Adaptation à la Fiévre de la Vallée du Rift" (AdaptFVR) has concluded a 10-year constructive interaction between many scientists/partners involved with the Rift Valley fever (RVF) dynamics in Senegal. The three targeted objectives reached were (i) to produce--in near real-time--validated risk maps for parked livestock exposed to RVF mosquitoes/vectors bites; (ii) to assess the impacts on RVF vectors from climate variability at different time-scales including climate change; and (iii) to isolate processes improving local livestock management and animal health. Based on these results, concrete, pro-active adaptive actions were taken on site, which led to the establishment of a RVF early warning system (RVFews). Bulletins were released in a timely fashion during the project, tested and validated in close collaboration with the local populations, i.e. the primary users. Among the strategic, adaptive methods developed, conducted and evaluated in terms of cost/benefit analyses are the larvicide campaigns and the coupled bio-mathematical (hydrological and entomological) model technologies, which are being transferred to the staff of the "Centre de Suivi Ecologique" (CSE) in Dakar during 2013. Based on the results from the AdaptFVR project, other projects with similar conceptual and modelling approaches are currently being implemented, e.g. for urban and rural malaria and dengue in the French Antilles. PMID:24258902

  3. Evaluating spatial-temporal dynamics of net primary productivity of different forest types in northeastern China based on improved FORCCHN.

    Directory of Open Access Journals (Sweden)

    Junfang Zhao

    Full Text Available An improved individual-based forest ecosystem carbon budget model for China (FORCCHN was applied to investigate the spatial-temporal dynamics of net primary productivity of different forest types in northeastern China. In this study, the forests of northeastern China were categorized into four ecological types according to their habitats and generic characteristics (evergreen broadleaf forest, deciduous broadleaf forest, evergreen needleleaf forest and deciduous needleleaf forest. The results showed that distribution and change of forest NPP in northeastern China were related to the different forest types. From 1981 to 2002, among the forest types in northeastern China, per unit area NPP and total NPP of deciduous broadleaf forest were the highest, with the values of 729.4 gC/(m(2•yr and 106.0 TgC/yr, respectively, followed by mixed broadleaf- needleleaf forest, deciduous needleleaf forest and evergreen needleleaf forest. From 1981 to 2002, per unit area NPP and total NPP of different forest types in northeastern China exhibited significant trends of interannual increase, and rapid increase was found between the 1980s and 1990s. The contribution of the different forest type's NPP to total NPP in northeastern China was clearly different. The greatest was deciduous broadleaf forest, followed by mixed broadleaf- needleleaf forest and deciduous needleleaf forest. The smallest was evergreen needleleaf forest. Spatial difference in NPP between different forest types was remarkable. High NPP values of deciduous needleleaf forest, mixed broadleaf- needleleaf forest and deciduous broadleaf forest were found in the Daxing'anling region, the southeastern of Xiaoxing'anling and Jilin province, and the Changbai Mountain, respectively. However, no regional differences were found for evergreen needleleaf NPP. This study provided not only an estimation NPP of different forest types in northeastern China but also a useful methodology for estimating forest

  4. In Vivo Synthesis of Cyclic-di-GMP Using a Recombinant Adenovirus Preferentially Improves Adaptive Immune Responses against Extracellular Antigens.

    Science.gov (United States)

    Alyaqoub, Fadel S; Aldhamen, Yasser A; Koestler, Benjamin J; Bruger, Eric L; Seregin, Sergey S; Pereira-Hicks, Cristiane; Godbehere, Sarah; Waters, Christopher M; Amalfitano, Andrea

    2016-02-15

    There is a compelling need for more effective vaccine adjuvants to augment induction of Ag-specific adaptive immune responses. Recent reports suggested the bacterial second messenger bis-(3'-5')-cyclic-dimeric-guanosine monophosphate (c-di-GMP) acts as an innate immune system modulator. We recently incorporated a Vibrio cholerae diguanylate cyclase into an adenovirus vaccine, fostering production of c-di-GMP as well as proinflammatory responses in mice. In this study, we recombined a more potent diguanylate cyclase gene, VCA0848, into a nonreplicating adenovirus serotype 5 (AdVCA0848) that produces elevated amounts of c-di-GMP when expressed in mammalian cells in vivo. This novel platform further improved induction of type I IFN-β and activation of innate and adaptive immune cells early after administration into mice as compared with control vectors. Coadministration of the extracellular protein OVA and the AdVCA0848 adjuvant significantly improved OVA-specific T cell responses as detected by IFN-γ and IL-2 ELISPOT, while also improving OVA-specific humoral B cell adaptive responses. In addition, we found that coadministration of AdVCA0848 with another adenovirus serotype 5 vector expressing the HIV-1-derived Gag Ag or the Clostridium difficile-derived toxin B resulted in significant inhibitory effects on the induction of Gag and toxin B-specific adaptive immune responses. As a proof of principle, these data confirm that in vivo synthesis of c-di-GMP stimulates strong innate immune responses that correlate with enhanced adaptive immune responses to concomitantly administered extracellular Ag, which can be used as an adjuvant to heighten effective immune responses for protein-based vaccine platforms against microbial infections and cancers.

  5. Improving the precision of CBIR systems by color and texture feature adaptation using GSA

    Directory of Open Access Journals (Sweden)

    E. Rashedi

    2013-12-01

    Full Text Available Content-based image retrieval, CBIR, is an interesting problem of pattern recognition. This paper is devoted to the presentation an approach to reduce the semantic gap between low level visual features and high level semantics by parameter adaptation in feature extraction sub-block. In the proposed method, GSA is used. In texture feature extraction, the parameters of a 6-tap parametrized orthogonal mother wavelet and in color feature extraction, the quantization levels are adapted to reach maximum precision of the image retrieval system. Experimental results and comparison with the conventional CBIR system are reported on a database of 1000 images. Results confirm the efficiency of the proposed adapted image retrieval system.

  6. Application of Improved Neural Adaptive PSD Algorithm in Temperature Control of INS

    Institute of Scientific and Technical Information of China (English)

    缪玲娟; 郭振西; 崔燕

    2004-01-01

    A neural adaptive proportion sum differential (PSD) algorithm with errors prediction is researched. It is applied in inertial navigation system(INS) temperature control. The algorithm do not need the process's precise mathematical model and can adapt to the process pareters changing, and can deal with the process with nonlinearity. According to the Smith predictor, author developed a method that takes the predicted process error and error change as neural adaptive PSD algorithm's input. The method is effective to the system with long dead time. The results of compute simulation show that this system has characters of quickly reaction, low overshoot and good stability. It can meet the requirements of temperature control of INS.

  7. Adaption of the Cytokinesis-Block Micronucleus Cytome Assay for Improved Triage Biodosimetry.

    Science.gov (United States)

    Beinke, C; Port, M; Riecke, A; Ruf, C G; Abend, M

    2016-05-01

    The purpose of this work was to adapt a more advanced form of the cytokinesis-block micronucleus (CBMN) cytome assay for triage biodosimetry in the event of a mass casualty radiation incident. We modified scoring procedures for the CBMN cytome assay to optimize field deployability, dose range, accuracy, speed, economy, simplicity and stability. Peripheral blood of 20 donors was irradiated in vitro (0-6 Gy X ray, maximum photon energy 240 keV) and processed for CBMN. Initially, we assessed two manual scoring strategies for accuracy: 1. Conventional scoring, comprised of micronucleus (MN) frequency per 1,000 binucleated (BN) cells (MN/1,000 BN cells); and 2. Evaluation of 1,000, 2,000 and 3,000 cells in total and different cellular subsets based on MN formation and proliferation (e.g., BN cells with and without MN, mononucleated cells). We used linear and logistic regression models to identify the cellular subsets related closest to dose with the best discrimination ability among different doses/dose categories. We validated the most promising subsets and their combinations with 16 blind samples covering a dose range of 0-8.3 Gy. Linear dose-response relationships comparable to the conventional CBMN assay (r(2) = 0.86) were found for BN cells with MN (r(2) = 0.84) and BN cells without MN (r(2) = 0.84). Models of combined cell counts (CCC) of BN cells with and without MN (BN(+MN) and BN(-MN)) with mononucleated cells (Mono) improved this relationship (r(2) = 0.92). Conventional CBMN discriminated dose categories up to 3 Gy with a concordance between 0.96-1.0 upon scoring 1,000 total cells. In 1,000 BN cells, concordances were observed for conventional CBMN up to 4 Gy as well as BN(+MN) or BN(-MN) (about 0.85). At doses of 4-6 Gy, the concordance of conventional CBMN, BN(+MN) and BN(-MN) declined (about 0.55). We found about 20% higher concordance and more precise dose estimates of irradiated and blinded samples for CCC (Mono + BN(+MN)) after scoring 1,000 total cells

  8. Efficiency and reliability improvement in wind turbine converters by grid converter adaptive control

    DEFF Research Database (Denmark)

    Trintis, Ionut; Munk-Nielsen, Stig; Abrahamsen, Flemming;

    2013-01-01

    and generator side. Operating in this way, the electrical and thermal stress factors are decreased on the power electronic devices, increasing their lifetime. The simulation results using this method show efficiency increase and devices temperature cycles slightly decreased. Experimental results on a...... wind turbine power stack shows efficiency increase in the high power region.......This paper presents a control method that reduces the losses in wind turbine converters adaptively controlling the grid converter. The dc-link voltage adapts its reference based on the system state and therefore reduces the stored energy, and is therefore kept at the minimum necessary for the grid...

  9. Simulation of Adaptive OFDM and its improved algorithm%自适应OFDM及其改进算法

    Institute of Scientific and Technical Information of China (English)

    郝丽娜; 宋金玲

    2011-01-01

    OFDM 技术是第四代移动通信的核心技术之一,是一种高效的数据传输方式,是一种特殊的多载波传输方案。本文介绍的改进后的自适应调制技术,自适应地根据星座图集所限定的比特数目来进行变步长调整,这样大大减少了计算量。并通过使用Matlab仿真出的结果与Campello算法仿真的结果进行比较,说明改进后的变步长的自适应OFDM算法的优越性。%OFDM technology is one of the core technologies of the fourth generation mobile communication, which is an efficient data transmission and is a special multi-carrier transmission scheme. The improved adaptive modulation technology adjusts the step of computing according to limited bits of constellation atlas, which reduce the computation greatly. Compared the result of the improved adaptive modulation technology with the result of Compello algorithm simulation, we find that the improved adaptive modulation OFDM technology has great advantages.

  10. Forecasting foreign exchange rates with an improved back-propagation learning algorithm with adaptive smoothing momentum terms

    Institute of Scientific and Technical Information of China (English)

    Lean YU; Shouyang WANG; Kin Keung LAI

    2009-01-01

    The slow convergence of back-propagation neu-ral network (BPNN) has become a challenge in data-mining and knowledge discovery applications due to the drawbacks of the gradient descent (GD) optimization method, which is widely adopted in BPNN learning. To solve this problem,some standard Optimization techniques such as conjugate-gradient and Newton method have been proposed to improve the convergence rate of BP learning algorithm. This paper presents a heuristic method that adds an adaptive smooth-ing momentum term to original BP learning algorithm to speedup the convergence. In this improved BP learning al-gorithm, adaptive smoothing technique is used to adjust the momentums of weight updating formula automatically in terms of "3 σ limits theory." Using the adaptive smoothing momentum terms, the improved BP learning algorithm can make the network training and convergence process faster,and the network's generalization performance stronger than the standard BP learning algorithm can do. In order to ver-ify the effectiveness of the proposed BP learning algorithm,three typical foreign exchange rates, British pound (GBP),Euro (EUR), and Japanese yen (JPY), are chosen as the fore-casting targets for illustration purpose. Experimental results from homogeneous algorithm comparisons reveal that the proposed BP learning algorithm outperforms the other com-parable BP algorithms in performance and convergence rate.Furthermore, empirical results from heterogeneous model comparisons also show the effectiveness of the proposed BP learning algorithm.

  11. Adaptive control algorithm for improving power capture of wind turbines in turbulent winds

    DEFF Research Database (Denmark)

    Diaz-Guerra, Lluis; Adegas, Fabiano Daher; Stoustrup, Jakob;

    2012-01-01

    conditions. This paper present new analysis tools and an adaptive control law to increase the energy captured by a wind turbine. Due to its simplicity, it can be easily added to existing industry-standard controllers. The effectiveness of the proposed algorithm is assessed by simulations on a high......-fidelity aeroelastic code....

  12. Analysis of revenue improvements with runtime adaptation of service composition based on conditional request retries

    NARCIS (Netherlands)

    Zivkovic, M.; Berg, J.L. van den

    2012-01-01

    In this paper we consider the runtime service adaptation mechanism for service compositions that is based on conditional retries. A single retry may be issued while a concrete service within composition is executed. This retry could either invoke the same concrete service or a functionally equivalen

  13. Identification of robust adaptation gene regulatory network parameters using an improved particle swarm optimization algorithm.

    Science.gov (United States)

    Huang, X N; Ren, H P

    2016-01-01

    Robust adaptation is a critical ability of gene regulatory network (GRN) to survive in a fluctuating environment, which represents the system responding to an input stimulus rapidly and then returning to its pre-stimulus steady state timely. In this paper, the GRN is modeled using the Michaelis-Menten rate equations, which are highly nonlinear differential equations containing 12 undetermined parameters. The robust adaption is quantitatively described by two conflicting indices. To identify the parameter sets in order to confer the GRNs with robust adaptation is a multi-variable, multi-objective, and multi-peak optimization problem, which is difficult to acquire satisfactory solutions especially high-quality solutions. A new best-neighbor particle swarm optimization algorithm is proposed to implement this task. The proposed algorithm employs a Latin hypercube sampling method to generate the initial population. The particle crossover operation and elitist preservation strategy are also used in the proposed algorithm. The simulation results revealed that the proposed algorithm could identify multiple solutions in one time running. Moreover, it demonstrated a superior performance as compared to the previous methods in the sense of detecting more high-quality solutions within an acceptable time. The proposed methodology, owing to its universality and simplicity, is useful for providing the guidance to design GRN with superior robust adaptation. PMID:27323043

  14. Improving spatio-temporal benefit transfers for pest control by generalist predators in cotton in the southwestern U.S.

    Science.gov (United States)

    Wiederholt, Ruscena; Bagstad, Kenneth J.; McCracken, Gary F.; Diffendorfer, Jay E.; Loomis, John B.; Semmens, Darius J.; Russell, Amy L.; Sansone, Chris; LaSharr, Kelsie; Cryan, Paul; Reynoso, Claudia; Medellin, Rodrigo A.; Lopez-Hoffman, Laura

    2017-01-01

    Given rapid changes in agricultural practice, it is critical to understand how alterations in ecological, technological, and economic conditions over time and space impact ecosystem services in agroecosystems. Here, we present a benefit transfer approach to quantify cotton pest-control services provided by a generalist predator, the Mexican free-tailed bat (Tadarida brasiliensis mexicana), in the southwestern United States. We show that pest-control estimates derived using (1) a compound spatial–temporal model – which incorporates spatial and temporal variability in crop pest-control service values – are likely to exhibit less error than those derived using (2) a simple-spatial model (i.e., a model that extrapolates values derived for one area directly, without adjustment, to other areas) or (3) a simple-temporal model (i.e., a model that extrapolates data from a few points in time over longer time periods). Using our compound spatial–temporal approach, the annualized pest-control value was $12.2 million, in contrast to an estimate of $70.1 million (5.7 times greater), obtained from the simple-spatial approach. Using estimates from one year (simple-temporal approach) revealed large value differences (0.4 times smaller to 2 times greater). Finally, we present a detailed protocol for valuing pest-control services, which can be used to develop robust pest-control transfer functions for generalist predators in agroecosystems.

  15. Singing can improve speech function in aphasics associated with intact right basal ganglia and preserve right temporal glucose metabolism: Implications for singing therapy indication.

    Science.gov (United States)

    Akanuma, Kyoko; Meguro, Kenichi; Satoh, Masayuki; Tashiro, Manabu; Itoh, Masatoshi

    2016-01-01

    Clinically, we know that some aphasic patients can sing well despite their speech disturbances. Herein, we report 10 patients with non-fluent aphasia, of which half of the patients improved their speech function after singing training. We studied ten patients with non-fluent aphasia complaining of difficulty finding words. All had lesions in the left basal ganglia or temporal lobe. They selected the melodies they knew well, but which they could not sing. We made a new lyric with a familiar melody using words they could not name. The singing training using these new lyrics was performed for 30 minutes once a week for 10 weeks. Before and after the training, their speech functions were assessed by language tests. At baseline, 6 of them received positron emission tomography to evaluate glucose metabolism. Five patients exhibited improvements after intervention; all but one exhibited intact right basal ganglia and left temporal lobes, but all exhibited left basal ganglia lesions. Among them, three subjects exhibited preserved glucose metabolism in the right temporal lobe. We considered that patients who exhibit intact right basal ganglia and left temporal lobes, together with preserved right hemispheric glucose metabolism, might be an indication of the effectiveness of singing therapy.

  16. FOG Random Drift Signal Denoising Based on the Improved AR Model and Modified Sage-Husa Adaptive Kalman Filter

    Science.gov (United States)

    Sun, Jin; Xu, Xiaosu; Liu, Yiting; Zhang, Tao; Li, Yao

    2016-01-01

    In order to reduce the influence of fiber optic gyroscope (FOG) random drift error on inertial navigation systems, an improved auto regressive (AR) model is put forward in this paper. First, based on real-time observations at each restart of the gyroscope, the model of FOG random drift can be established online. In the improved AR model, the FOG measured signal is employed instead of the zero mean signals. Then, the modified Sage-Husa adaptive Kalman filter (SHAKF) is introduced, which can directly carry out real-time filtering on the FOG signals. Finally, static and dynamic experiments are done to verify the effectiveness. The filtering results are analyzed with Allan variance. The analysis results show that the improved AR model has high fitting accuracy and strong adaptability, and the minimum fitting accuracy of single noise is 93.2%. Based on the improved AR(3) model, the denoising method of SHAKF is more effective than traditional methods, and its effect is better than 30%. The random drift error of FOG is reduced effectively, and the precision of the FOG is improved. PMID:27420062

  17. FOG Random Drift Signal Denoising Based on the Improved AR Model and Modified Sage-Husa Adaptive Kalman Filter.

    Science.gov (United States)

    Sun, Jin; Xu, Xiaosu; Liu, Yiting; Zhang, Tao; Li, Yao

    2016-01-01

    In order to reduce the influence of fiber optic gyroscope (FOG) random drift error on inertial navigation systems, an improved auto regressive (AR) model is put forward in this paper. First, based on real-time observations at each restart of the gyroscope, the model of FOG random drift can be established online. In the improved AR model, the FOG measured signal is employed instead of the zero mean signals. Then, the modified Sage-Husa adaptive Kalman filter (SHAKF) is introduced, which can directly carry out real-time filtering on the FOG signals. Finally, static and dynamic experiments are done to verify the effectiveness. The filtering results are analyzed with Allan variance. The analysis results show that the improved AR model has high fitting accuracy and strong adaptability, and the minimum fitting accuracy of single noise is 93.2%. Based on the improved AR(3) model, the denoising method of SHAKF is more effective than traditional methods, and its effect is better than 30%. The random drift error of FOG is reduced effectively, and the precision of the FOG is improved. PMID:27420062

  18. FOG Random Drift Signal Denoising Based on the Improved AR Model and Modified Sage-Husa Adaptive Kalman Filter.

    Science.gov (United States)

    Sun, Jin; Xu, Xiaosu; Liu, Yiting; Zhang, Tao; Li, Yao

    2016-07-12

    In order to reduce the influence of fiber optic gyroscope (FOG) random drift error on inertial navigation systems, an improved auto regressive (AR) model is put forward in this paper. First, based on real-time observations at each restart of the gyroscope, the model of FOG random drift can be established online. In the improved AR model, the FOG measured signal is employed instead of the zero mean signals. Then, the modified Sage-Husa adaptive Kalman filter (SHAKF) is introduced, which can directly carry out real-time filtering on the FOG signals. Finally, static and dynamic experiments are done to verify the effectiveness. The filtering results are analyzed with Allan variance. The analysis results show that the improved AR model has high fitting accuracy and strong adaptability, and the minimum fitting accuracy of single noise is 93.2%. Based on the improved AR(3) model, the denoising method of SHAKF is more effective than traditional methods, and its effect is better than 30%. The random drift error of FOG is reduced effectively, and the precision of the FOG is improved.

  19. Improving Depiction of Temporal Bone Anatomy With Low-Radiation Dose CT by an Integrated Circuit Detector in Pediatric Patients

    Science.gov (United States)

    He, Jingzhen; Zu, Yuliang; Wang, Qing; Ma, Xiangxing

    2014-01-01

    Abstract The purpose of this study was to determine the performance of low-dose computed tomography (CT) scanning with integrated circuit (IC) detector in defining fine structures of temporal bone in children by comparing with the conventional detector. The study was performed with the approval of our institutional review board and the patients’ anonymity was maintained. A total of 86 children  0.05). The low-dose CT images acquired with the IC detector provide better depiction of fine osseous structures of temporal bone than that with the conventional DC detector. PMID:25526489

  20. Improving the performance of link prediction by adaptively exploiting multiple structural features of networks

    CERN Document Server

    Ma, Chuang; Zhang, Hai-Feng

    2016-01-01

    So far, many network-structure-based link prediction methods have been proposed. However, these traditional methods were proposed by highlighting one or two structural features of networks, and then use the methods to implement link prediction in different networks. In many cases, the performance is not ideal since each network has its unique underlying structural features. In this article, by analyzing different real networks, we find that the structural features of different networks are remarkably different. In particular, even in the same networks, their inner structural features are utterly different. Inspired by these facts, an \\emph{adaptive} link prediction method is proposed to incorporate multiple structural features from the perspective of combination optimization. In the model, the weight of each structural feature is \\emph{adaptively } determined by logistic regression but not be artificially given in advance. According to our experimental results, we find that the logistic regression based link ...

  1. Adaptive Representations for Improving Evolvability, Parameter Control, and Parallelization of Gene Expression Programming

    Directory of Open Access Journals (Sweden)

    Nigel P. A. Browne

    2010-01-01

    Full Text Available Gene Expression Programming (GEP is a genetic algorithm that evolves linear chromosomes encoding nonlinear (tree-like structures. In the original GEP algorithm, the genome size is problem specific and is determined through trial and error. In this work, a method for adaptive control of the genome size is presented. The approach introduces mutation, transposition, and recombination operators that enable a population of heterogeneously structured chromosomes, something the original GEP algorithm does not support. This permits crossbreeding between normally incompatible individuals, speciation within a population, increases the evolvability of the representations, and enhances parallel GEP. To test our approach, an assortment of problems were used, including symbolic regression, classification, and parameter optimization. Our experimental results show that our approach provides a solution for the problem of self-adaptive control of the genome size of GEP's representation.

  2. Single breath-hold real-time cine MR imaging: improved temporal resolution using generalized autocalibrating partially parallel acquisition (GRAPPA) algorithm

    International Nuclear Information System (INIS)

    The purpose of this study was to test parallel imaging techniques for improvement of temporal resolution in multislice single breath-hold real-time cine steady-state free precession (SSFP) in comparison with standard segmented single-slice SSFP techniques. Eighteen subjects were examined on a 1.5-T scanner using a multislice real-time cine SSFP technique using the GRAPPA algorithm. Global left ventricular parameters (EDV, ESV, SV, EF) were evaluated and results compared with a standard segmented single-slice SSFP technique. Results for EDV (r=0.93), ESV (r=0.99), SV (r=0.83), and EF (r=0.99) of real-time multislice SSFP imaging showed a high correlation with results of segmented SSFP acquisitions. Systematic differences between both techniques were statistically non-significant. Single breath-hold multislice techniques using GRAPPA allow for improvement of temporal resolution and for accurate assessment of global left ventricular functional parameters. (orig.)

  3. Adaptive High-Bandwidth Digitally Controlled Buck Converter with Improved Line and Load Transient Response

    OpenAIRE

    Lee, ATL; Sin, JKO; Chan, PCH

    2014-01-01

    Digitally controlled switching converter suffers from bandwidth limitation because of the additional phase delay in the digital feedback control loop. In order to overcome the bandwidth limitation without using a high sampling rate, this paper presents an adaptive third-order digital controller for regulating a voltage-mode buck converter with a modest 2x oversampling ratio. The phase lag due to the ADC conversion time delay is virtually compensated by providing an early estimation of the err...

  4. Improving Inpatient Surveys: Web-Based Computer Adaptive Testing Accessed via Mobile Phone QR Codes

    OpenAIRE

    Chien, Tsair-Wei; Lin, Weir-Sen

    2016-01-01

    Background The National Health Service (NHS) 70-item inpatient questionnaire surveys inpatients on their perceptions of their hospitalization experience. However, it imposes more burden on the patient than other similar surveys. The literature shows that computerized adaptive testing (CAT) based on item response theory can help shorten the item length of a questionnaire without compromising its precision. Objective Our aim was to investigate whether CAT can be (1) efficient with item reductio...

  5. Studying citizen science through adaptive management and learning feedbacks as mechanisms for improving conservation.

    Science.gov (United States)

    Jordan, Rebecca; Gray, Steven; Sorensen, Amanda; Newman, Greg; Mellor, David; Newman, Greg; Hmelo-Silver, Cindy; LaDeau, Shannon; Biehler, Dawn; Crall, Alycia

    2016-06-01

    Citizen science has generated a growing interest among scientists and community groups, and citizen science programs have been created specifically for conservation. We examined collaborative science, a highly interactive form of citizen science, which we developed within a theoretically informed framework. In this essay, we focused on 2 aspects of our framework: social learning and adaptive management. Social learning, in contrast to individual-based learning, stresses collaborative and generative insight making and is well-suited for adaptive management. Adaptive-management integrates feedback loops that are informed by what is learned and is guided by iterative decision making. Participants engaged in citizen science are able to add to what they are learning through primary data collection, which can result in the real-time information that is often necessary for conservation. Our work is particularly timely because research publications consistently report a lack of established frameworks and evaluation plans to address the extent of conservation outcomes in citizen science. To illustrate how our framework supports conservation through citizen science, we examined how 2 programs enacted our collaborative science framework. Further, we inspected preliminary conservation outcomes of our case-study programs. These programs, despite their recent implementation, are demonstrating promise with regard to positive conservation outcomes. To date, they are independently earning funds to support research, earning buy-in from local partners to engage in experimentation, and, in the absence of leading scientists, are collecting data to test ideas. We argue that this success is due to citizen scientists being organized around local issues and engaging in iterative, collaborative, and adaptive learning.

  6. Aortic pressure wave reconstruction during exercise is improved by adaptive filtering: a pilot study

    OpenAIRE

    Stok, W.J.; Westerhof, B E; Guelen, I.; Karemaker, J. M.

    2011-01-01

    Reconstruction of central aortic pressure from a peripheral measurement by a generalized transfer function (genTF) works well at rest and mild exercise at lower heart rates, but becomes less accurate during heavy exercise. Particularly, systolic and pulse pressure estimations deteriorate, thereby underestimating central pressure. We tested individualization of the TF (indTF) by adapting its resonance frequency at the various levels of exercise. In seven males (age 44–57) with coronary artery ...

  7. Adaptive Critic Based Neuro-Fuzzy Tracker for Improving Conversion Efficiency in PV Solar Cells

    OpenAIRE

    Halimeh Rashidi; Saeed Niazi; Jamshid Khorshidi

    2012-01-01

    The output power of photovoltaic systems is directly related to the amount of solar energy collected by the system and it is therefore necessary to track the sun’s position with high accuracy. This study proposes multi-agent adaptive critic based nero fuzzy solar tracking system dedicated to PV panels. The proposed tracker ensures the optimal conversion of solar energy into electricity by properly adjusting the PV panels according to the position of the sun. To evaluate the usefulness of the ...

  8. Studying citizen science through adaptive management and learning feedbacks as mechanisms for improving conservation.

    Science.gov (United States)

    Jordan, Rebecca; Gray, Steven; Sorensen, Amanda; Newman, Greg; Mellor, David; Newman, Greg; Hmelo-Silver, Cindy; LaDeau, Shannon; Biehler, Dawn; Crall, Alycia

    2016-06-01

    Citizen science has generated a growing interest among scientists and community groups, and citizen science programs have been created specifically for conservation. We examined collaborative science, a highly interactive form of citizen science, which we developed within a theoretically informed framework. In this essay, we focused on 2 aspects of our framework: social learning and adaptive management. Social learning, in contrast to individual-based learning, stresses collaborative and generative insight making and is well-suited for adaptive management. Adaptive-management integrates feedback loops that are informed by what is learned and is guided by iterative decision making. Participants engaged in citizen science are able to add to what they are learning through primary data collection, which can result in the real-time information that is often necessary for conservation. Our work is particularly timely because research publications consistently report a lack of established frameworks and evaluation plans to address the extent of conservation outcomes in citizen science. To illustrate how our framework supports conservation through citizen science, we examined how 2 programs enacted our collaborative science framework. Further, we inspected preliminary conservation outcomes of our case-study programs. These programs, despite their recent implementation, are demonstrating promise with regard to positive conservation outcomes. To date, they are independently earning funds to support research, earning buy-in from local partners to engage in experimentation, and, in the absence of leading scientists, are collecting data to test ideas. We argue that this success is due to citizen scientists being organized around local issues and engaging in iterative, collaborative, and adaptive learning. PMID:26585836

  9. An Improved QoS Multipath Routing Using Bandwidth Estimation and Rate Adaptation

    Directory of Open Access Journals (Sweden)

    S. Suganya

    2014-06-01

    Full Text Available Mobile Adhoc Networks (MANETs are composed of nodes which communicate with one another without network infrastructure. Their advantage being that they can be used in isolation or along with wired infrastructure, usually via a gateway node to ensure traffic relay for both networks. Quality of Service (QoS is harder to ensure in ad hoc networks than in other network types, as wireless bandwidth is shared by adjacent nodes with network topology changing as nodes move. Most QoS protocols are implemented for specific scenarios and consider parameters such as network topologies, bandwidth, mobility, security and so on. This work proposes a novel multipath routing protocol which is an extension of AOMDV by discovering routes based on available bandwidth and rate adaptation. The method with Hello message box is used to calculate available bandwidth for a route. Relative Fairness and Optimized Throughput is an approach for rate adaptation in this paper which is to ensure fairness and allow nodes to adapt transmission rates and contention windows to channel quality. In sequence this is determined by calculating the access probability of a channel for each node in a distributed manner approximating successful and failed transmissions.

  10. A Novel Clinical Decision Support System Using Improved Adaptive Genetic Algorithm for the Assessment of Fetal Well-Being

    Directory of Open Access Journals (Sweden)

    Sindhu Ravindran

    2015-01-01

    Full Text Available A novel clinical decision support system is proposed in this paper for evaluating the fetal well-being from the cardiotocogram (CTG dataset through an Improved Adaptive Genetic Algorithm (IAGA and Extreme Learning Machine (ELM. IAGA employs a new scaling technique (called sigma scaling to avoid premature convergence and applies adaptive crossover and mutation techniques with masking concepts to enhance population diversity. Also, this search algorithm utilizes three different fitness functions (two single objective fitness functions and multi-objective fitness function to assess its performance. The classification results unfold that promising classification accuracy of 94% is obtained with an optimal feature subset using IAGA. Also, the classification results are compared with those of other Feature Reduction techniques to substantiate its exhaustive search towards the global optimum. Besides, five other benchmark datasets are used to gauge the strength of the proposed IAGA algorithm.

  11. Improving traffic flow at a 2-to-1 lane reduction with wirelessly connected, adaptive cruise control vehicles

    CERN Document Server

    Davis, L C

    2015-01-01

    Wirelessly connected vehicles that exchange information about traffic conditions can reduce delays caused by congestion. At a 2-to-1 lane reduction, the improvement in flow past a bottleneck due to traffic with a random mixture of 40% connected vehicles is found to be 52%. Control is based on connected-vehicle-reported velocities near the bottleneck. In response to indications of congestion the connected vehicles, which are also adaptive cruise control vehicles, reduce their speed in slowdown regions. Early lane changes of manually driven vehicles from the terminated lane to the continuous lane are induced by the slowing connected vehicles. Self-organized congestion at the bottleneck is thus delayed or eliminated, depending upon the incoming flow magnitude. For the large majority of vehicles, travel times past the bottleneck are substantially reduced. Control is responsible for delaying the onset of congestion as the incoming flow increases. Adaptive cruise control increases the flow out of the congested stat...

  12. Automated interferometric synthetic aperture microscopy and computational adaptive optics for improved optical coherence tomography.

    Science.gov (United States)

    Xu, Yang; Liu, Yuan-Zhi; Boppart, Stephen A; Carney, P Scott

    2016-03-10

    In this paper, we introduce an algorithm framework for the automation of interferometric synthetic aperture microscopy (ISAM). Under this framework, common processing steps such as dispersion correction, Fourier domain resampling, and computational adaptive optics aberration correction are carried out as metrics-assisted parameter search problems. We further present the results of this algorithm applied to phantom and biological tissue samples and compare with manually adjusted results. With the automated algorithm, near-optimal ISAM reconstruction can be achieved without manual adjustment. At the same time, the technical barrier for the nonexpert using ISAM imaging is also significantly lowered. PMID:26974799

  13. Decentralised nonlinear equilibrium point adaptive control of generator for improving multimachine power system transient stability

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.; Yokoyama, A. [Tokyo Univ., Tokyo (Japan); Lu, Q. [TsingHua Univ., Tsinghua (China); Goto, M. [Nagoya Univ., Nagoya (Japan); Konishi, H. [Hitachi Ltd. (Japan)

    2003-11-01

    Decentralised nonlinear control of generator excitation and turbine governor based on the feedback linearization approach is proposed. To make the proposed nonlinear control possess adaptive ability under the changing conditions of power systems, the extended observation decoupled state space in which mechanical power is considered as variable is proposed, and the local stability of the post fault equilibrium point is established rigorously from a mathematical viewpoint. Nonlinear simulations are performed in a three-machine power system and in the ten-machine West Japan power system, and the effectiveness of the proposed nonlinear control and the convergence characteristics of the post fault equilibrium point observer are validated. (Author)

  14. Adaptive Learning and Thinking Style to Improve E-Learning Environment Using Neural Network (ALTENN) Model

    OpenAIRE

    Dagez, Hanan Ettaher; Ambarka, Ali Elghali

    2015-01-01

     In recent years we have witnessed an increasingly heightened awareness of the potential benefits of adaptively in e-learning. This has been mainly driven by the realization that the ideal of individualized learning (i.e., learning tailored to the specific requirements and preferences of the individual) cannot be achieved, especially at a “massive” scale, using traditional approaches. In e-learning when the learning style of the student is not compatible with the teaching style of the teacher...

  15. Adaptive feedforward of estimated ripple improves the closed loop system performance significantly

    International Nuclear Information System (INIS)

    The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos National Laboratory will serve as the prototype for the low energy section of Acceleration Production of Tritium (APT) accelerator. This paper addresses the problem of LLRF control system for LEDA. The authors propose an estimator of the ripple and its time derivative and a control law which is based on PID control and adaptive feedforward of estimated ripple. The control law reduces the effect of the deterministic cathode ripple that is due to high voltage power supply and achieves tracking of desired set points

  16. Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

    International Nuclear Information System (INIS)

    Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment. We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger’s method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger’s result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location

  17. Improving the response of accelerometers for automotive applications by using LMS adaptive filters.

    Science.gov (United States)

    Hernandez, Wilmar; de Vicente, Jesús; Sergiyenko, Oleg; Fernández, Eduardo

    2010-01-01

    In this paper, the least-mean-squares (LMS) algorithm was used to eliminate noise corrupting the important information coming from a piezoresisitive accelerometer for automotive applications. This kind of accelerometer is designed to be easily mounted in hard to reach places on vehicles under test, and they usually feature ranges from 50 to 2,000 g (where is the gravitational acceleration, 9.81 m/s(2)) and frequency responses to 3,000 Hz or higher, with DC response, durable cables, reliable performance and relatively low cost. However, here we show that the response of the sensor under test had a lot of noise and we carried out the signal processing stage by using both conventional and optimal adaptive filtering. Usually, designers have to build their specific analog and digital signal processing circuits, and this fact increases considerably the cost of the entire sensor system and the results are not always satisfactory, because the relevant signal is sometimes buried in a broad-band noise background where the unwanted information and the relevant signal sometimes share a very similar frequency band. Thus, in order to deal with this problem, here we used the LMS adaptive filtering algorithm and compare it with others based on the kind of filters that are typically used for automotive applications. The experimental results are satisfactory.

  18. Improving the response of accelerometers for automotive applications by using LMS adaptive filters.

    Science.gov (United States)

    Hernandez, Wilmar; de Vicente, Jesús; Sergiyenko, Oleg; Fernández, Eduardo

    2010-01-01

    In this paper, the least-mean-squares (LMS) algorithm was used to eliminate noise corrupting the important information coming from a piezoresisitive accelerometer for automotive applications. This kind of accelerometer is designed to be easily mounted in hard to reach places on vehicles under test, and they usually feature ranges from 50 to 2,000 g (where is the gravitational acceleration, 9.81 m/s(2)) and frequency responses to 3,000 Hz or higher, with DC response, durable cables, reliable performance and relatively low cost. However, here we show that the response of the sensor under test had a lot of noise and we carried out the signal processing stage by using both conventional and optimal adaptive filtering. Usually, designers have to build their specific analog and digital signal processing circuits, and this fact increases considerably the cost of the entire sensor system and the results are not always satisfactory, because the relevant signal is sometimes buried in a broad-band noise background where the unwanted information and the relevant signal sometimes share a very similar frequency band. Thus, in order to deal with this problem, here we used the LMS adaptive filtering algorithm and compare it with others based on the kind of filters that are typically used for automotive applications. The experimental results are satisfactory. PMID:22315542

  19. Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

    Energy Technology Data Exchange (ETDEWEB)

    Ry, Rexha Verdhora, E-mail: rexha.vry@gmail.com [Master Program of Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha No.10, Bandung 40132 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Research Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha No.10, Bandung 40132 (Indonesia)

    2015-04-24

    Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment. We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger’s method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger’s result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location.

  20. Species adaptability, seed availability and prospects for improvement of eucalyptus in Minas Gerais

    Energy Technology Data Exchange (ETDEWEB)

    Ferrevia, M.; Balloni, E.A.; Pinto, J.E. Jr.; Jacob, W.S.

    1978-01-01

    As part of a continuing study into possible improvement of Eucalyptus spp. in plantations, data are presented from all existing trials and experimental plantings in Minas Gerais, Brazil. Growth, uniformity, form and fruiting are indicated.

  1. Adaptive Critic Based Neuro-Fuzzy Tracker for Improving Conversion Efficiency in PV Solar Cells

    Directory of Open Access Journals (Sweden)

    Halimeh Rashidi

    2012-08-01

    Full Text Available The output power of photovoltaic systems is directly related to the amount of solar energy collected by the system and it is therefore necessary to track the sun’s position with high accuracy. This study proposes multi-agent adaptive critic based nero fuzzy solar tracking system dedicated to PV panels. The proposed tracker ensures the optimal conversion of solar energy into electricity by properly adjusting the PV panels according to the position of the sun. To evaluate the usefulness of the proposed method, some computer simulations are performed and compared with fuzzy PD controller. Obtained results show the proposed control strategy is very robust, flexible and could be used to get the desired performance levels. The response time is also very fast. Simulation results that have been compared with fuzzy PD controller show that our method has the better control performance than fuzzy PD controller.

  2. Cultural adaptation of an evidence-based nursing intervention to improve medication adherence among people living with HIV/AIDS (PLWHA) in China

    Science.gov (United States)

    Williams, Ann B.; Wang, Honghong; Burgess, Jane; Li, Xianhong; Danvers, Karina

    2012-01-01

    BACKGROUND Adapting nursing interventions to suit the needs and culture of a new population (cultural adaptation) is an important early step in the process of implementation and dissemination. While the need for cultural adaptation is widely accepted, research-based strategies for doing so are not well articulated. Non-adherence to medications for chronic disease is a global problem and cultural adaptation of existing evidence-based interventions could be useful. OBJECTIVES This paper aims to describe the cultural adaptation of an evidence-based nursing intervention to improve medication adherence among people living with HIV/AIDS and to offer recommendations for adaptation of interventions across cultures and borders. SITE The intervention, which demonstrated efficacy in a randomized controlled trial in North America, was adapted for the cultural and social context of Hunan Province, in south central China. SOURCES OF DATA The adaptation process was undertaken by intervention stakeholders including the original intervention study team, the proposed adaptation team, and members of a Community Advisory Board, including people living with HIV/AIDS, family members, and health care workers at the target clinical sites. PROCEDURES The adaptation process was driven by quantitative and qualitative data describing the new population and context and was guided by principles for cultural adaptation drawn from prevention science research. RESULTS The primary adaptation to the intervention was the inclusion of family members in intervention activities, in response to the cultural and social importance of the family in rural China. In a pilot test of the adapted intervention, self-reported medication adherence improved significantly in the group receiving the intervention compared to the control group (p=0.01). Recommendations for cultural adaptation of nursing interventions include 1) involve stakeholders from the beginning; 2) assess the population, need, and context; 3

  3. Improving traffic flow at a 2-to-1 lane reduction with wirelessly connected, adaptive cruise control vehicles

    Science.gov (United States)

    Davis, L. C.

    2016-06-01

    Wirelessly connected vehicles that exchange information about traffic conditions can reduce delays caused by congestion. At a 2-to-1 lane reduction, the improvement in flow past a bottleneck due to traffic with a random mixture of 40% connected vehicles is found to be 52%. Control is based on connected-vehicle-reported velocities near the bottleneck. In response to indications of congestion the connected vehicles, which are also adaptive cruise control vehicles, reduce their speed in slowdown regions. Early lane changes of manually driven vehicles from the terminated lane to the continuous lane are induced by the slowing connected vehicles. Self-organized congestion at the bottleneck is thus delayed or eliminated, depending upon the incoming flow magnitude. For the large majority of vehicles, travel times past the bottleneck are substantially reduced. Control is responsible for delaying the onset of congestion as the incoming flow increases. Adaptive cruise control increases the flow out of the congested state at the bottleneck. The nature of the congested state, when it occurs, appears to be similar under a variety of conditions. Typically 80-100 vehicles are approximately equally distributed between the lanes in the 500 m region prior to the end of the terminated lane. Without the adaptive cruise control capability, connected vehicles can delay the onset of congestion but do not increase the asymptotic flow past the bottleneck. Calculations are done using the Kerner-Klenov three-phase theory, stochastic discrete-time model for manual vehicles. The dynamics of the connected vehicles is given by a conventional adaptive cruise control algorithm plus commanded deceleration. Because time in the model for manual vehicles is discrete (one-second intervals), it is assumed that the acceleration of any vehicle immediately in front of a connected vehicle is constant during the time interval, thereby preserving the computational simplicity and speed of a discrete-time model.

  4. An Improved Character Segmentation Algorithm Based on Local Adaptive Thresholding Technique for Chinese NvShu Documents

    Directory of Open Access Journals (Sweden)

    Yangguang Sun

    2014-06-01

    Full Text Available For the structural characteristics of Chinese NvShu character, by combining the basic idea in LLT local threshold algorithm and introducing the maximal between-class variance algorithm into local windows, an improved character segmentation algorithm based on local adaptive thresholding technique for Chinese NvShu documents was presented in this paper. Because of designing the corresponding correction parameters for the threshold and using secondary search mechanism, our proposed method could not only automatically obtain local threshold, but also avoid the loss of the character image information and improve the accuracy of the character image segmentation. Experimental results demonstrated its capability to reduce the effect of background noise, especially for Chinese NvShu character images with uneven illumination and low contrast

  5. An adaptation method to improve secret key rates of time-frequency QKD in atmospheric turbulence channels

    Science.gov (United States)

    Sun, Xiaole; Djordjevic, Ivan B.; Neifeld, Mark A.

    2016-03-01

    Free-space optical (FSO) channels can be characterized by random power fluctuations due to atmospheric turbulence, which is known as scintillation. Weak coherent source based FSO quantum key distribution (QKD) systems suffer from the scintillation effect because during the deep channel fading the expected detection rate drops, which then gives an eavesdropper opportunity to get additional information about protocol by performing photon number splitting (PNS) attack and blocking single-photon pulses without changing QBER. To overcome this problem, in this paper, we study a large-alphabet QKD protocol, which is achieved by using pulse-position modulation (PPM)-like approach that utilizes the time-frequency uncertainty relation of the weak coherent photon state, called here TF-PPM-QKD protocol. We first complete finite size analysis for TF-PPM-QKD protocol to give practical bounds against non-negligible statistical fluctuation due to finite resources in practical implementations. The impact of scintillation under strong atmospheric turbulence regime is studied then. To overcome the secure key rate performance degradation of TF-PPM-QKD caused by scintillation, we propose an adaptation method for compensating the scintillation impact. By changing source intensity according to the channel state information (CSI), obtained by classical channel, the adaptation method improves the performance of QKD system with respect to the secret key rate. The CSI of a time-varying channel can be predicted using stochastic models, such as autoregressive (AR) models. Based on the channel state predictions, we change the source intensity to the optimal value to achieve a higher secret key rate. We demonstrate that the improvement of the adaptation method is dependent on the prediction accuracy.

  6. Improving productivity software through the adaptation of an agile development framework

    Directory of Open Access Journals (Sweden)

    Ángel Fiallos Ordoñez

    2015-06-01

    Full Text Available (Received: 2015/02/20 - Accepted: 2015/06/17The current research suggests that using of agile methodologies in conjunction with open source software tools can improve productivity, reduce costs and optimize resources in the process of software development, and helps improve user satisfaction due to implementation of excellent quality software. The following analysis shows the most important variables for the successful implementation of IT development projects and their relation with the use of traditional and agile software development methodologies.

  7. Improvement of the Hopfield Neural Network by MC-Adaptation Rule

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhen; ZHAO Hong

    2006-01-01

    We show that the performance of the Hopfield neural networks, especially the quality of the recall and the capacity of the effective storing, can be greatly improved by making use of a recently presented neural network designing method without altering the whole structure of the network. In the improved neural network, a memory pattern is recalled exactly from initial states having a given degree of similarity with the memory pattern, and thus one can avoids to apply the overlap criterion as carried out in the Hopfield neural networks.

  8. Improved adaptive input voltage control of a solar array interfacing current mode controlled boost power stage

    International Nuclear Information System (INIS)

    Highlights: • Photovoltaic generator dynamic resistance online estimation method is proposed. • Control method allowing to achieve nominal performance at all time is presented. • The method is suitable for any type of photovoltaic system. - Abstract: Nonlinear characteristics of photovoltaic generators were recently shown to significantly influence the dynamics of interfacing power stages. Moreover, since the dynamic resistance of photovoltaic generators is both operating point and environmental variables dependent, the combined dynamics exhibits these dependencies as well, burdening control challenge. Typically, linear time invariant input voltage loop controllers (e.g. Proportional-Integrative-Derivative) are utilized in photovoltaic applications, designed according to nominal operating conditions. Nevertheless, since actual dynamics is seldom nominal, closed loop performance of such systems varies as well. In this paper, adaptive control method is proposed, allowing to estimate photovoltaic generator resistance online and utilize it to modify the controller parameters such that closed loop performance remains nominal throughout the whole operation range. Unlike previously proposed method, utilizing double-grid-frequency component for estimation purposes and suffering from various drawbacks such as operation point dependence and applicability to single-phase grid connected systems only, the proposed method is based on harmonic current injection and is independent on operating point and system topology

  9. Improved testing characteristics of austenitic and mixed welds by inverse phase adaptation of phased array signals

    International Nuclear Information System (INIS)

    Thin-walled welds (less than 10 mm wall thickness) in austenitic pipes and mixed welds are difficult to test using non-destructive methods. This is true especially for detection of closed cracks, which is impossible by radiographic testing and problematic by ultrasonic testing. Several projects in reactor safety research provided better understanding of the testing characteristics of thes compounds. The resulting rules for writing of test specifications and for qualification of the technology employed also showed the limits of radiographic and ultrasonic testing. One important result was the simulation of the propagation of ultrasonic waves in model descriptions of welded structures as a function of the shape of the product. This allows, in principle, the applicaiton of ultrasonic migration techniques which enable consideration of phase disturbances gy structural anisotropy when the time signals of the ultrasonic sensor elements are summed up. The applicability of this 'inverse phase adaptation' was proved in heterogeneous and anisotropic model test bodies and on test bodies of the reactor safety programme. The contribution outlines the fundamentals of the technology and presents preliminary findings. (orig.)

  10. Alternative Adaptive Filter Structures for Improved Radio Frequency Interference Cancellation in Radio Astronomy

    CERN Document Server

    Mitchell, D A; Sault, R J

    2010-01-01

    In radio astronomy, reference signals from auxiliary antennas that receive only the radio frequency interference (RFI) can be modified to model the RFI environment at the astronomy receivers. The RFI can then be canceled from the astronomy signal paths. However, astronomers typically only require signal statistics. If the RFI statistics are changing slowly, the cancellation can be applied to the signal correlations at a much lower rate than is required for standard adaptive filters. In this paper we describe five canceler setups; precorrelation and postcorrelation cancelers that use one or two reference signals in different ways. The theoretical residual RFI and added noise levels are examined and are demonstrated using microwave television RFI at the Australia Telescope Compact Array. The RFI is attenuated to below the system noise, a reduction of at least 20 dB. While dual-reference cancelers add more reference noise than single-reference cancelers, this noise is zero-mean and only adds to the system noise,...

  11. Mechanically adaptive intracortical implants improve the proximity of neuronal cell bodies

    Science.gov (United States)

    Harris, J. P.; Capadona, J. R.; Miller, R. H.; Healy, B. C.; Shanmuganathan, K.; Rowan, S. J.; Weder, C.; Tyler, D. J.

    2011-10-01

    The hypothesis is that the mechanical mismatch between brain tissue and microelectrodes influences the inflammatory response. Our unique, mechanically adaptive polymer nanocomposite enabled this study within the cerebral cortex of rats. The initial tensile storage modulus of 5 GPa decreases to 12 MPa within 15 min under physiological conditions. The response to the nanocomposite was compared to surface-matched, stiffer implants of traditional wires (411 GPa) coated with the identical polymer substrate and implanted on the contralateral side. Both implants were tethered. Fluorescent immunohistochemistry labeling examined neurons, intermediate filaments, macrophages, microglia and proteoglycans. We demonstrate, for the first time, a system that decouples the mechanical and surface chemistry components of the neural response. The neuronal nuclei density within 100 µm of the device at four weeks post-implantation was greater for the compliant nanocomposite compared to the stiff wire. At eight weeks post-implantation, the neuronal nuclei density around the nanocomposite was maintained, but the density around the wire recovered to match that of the nanocomposite. The glial scar response to the compliant nanocomposite was less vigorous than it was to the stiffer wire. The results suggest that mechanically associated factors such as proteoglycans and intermediate filaments are important modulators of the response of the compliant nanocomposite.

  12. Speed endurance training is a powerful stimulus for physiological adaptations and performance improvements of athletes

    DEFF Research Database (Denmark)

    Iaia, F. M.; Bangsbo, Jens

    2010-01-01

    the oxidative capacity and improve intense short-duration/repeated high-intensity exercise performance lasting 30 s to 4 min, as it occurs in a number of sports. When combined with a basic volume of training including some aerobic high-intensity sessions, speed endurance training is also useful in enhancing...... performance during longer events, e.g. 40 K cycling and 10 K running. Athletes in team sports involving intense exercise actions and endurance aspects can also benefit from performing speed endurance training. These improvements don't appear to depend on changes in maximum oxygen uptake (VO2max), muscle......The present article reviews the physiological and performance effects of speed endurance training consisting of exercise bouts at near maximal intensities in already trained subjects. Despite a reduction in training volume, speed endurance training of endurance-trained athletes can maintain...

  13. Scrumban - Adaptive Agile Development Process : Using scrumban to improve software development process

    OpenAIRE

    Khan, Zahoor

    2014-01-01

    This thesis concentrates on improving the existing agile software development process used in the case company in order to overcome the various problems faced during the product development based on the existing Scrum model. The case company, consisting of sixty five employees, turns any online content, images, videos and applications into interactive and viral storefronts by means of non-intrusive and content relevant advertisement products. After describing the research objective, rese...

  14. Proposing an adaptive mutation to improve XCSF performance to classify ADHD and BMD patients

    Science.gov (United States)

    Sadatnezhad, Khadijeh; Boostani, Reza; Ghanizadeh, Ahmad

    2010-12-01

    There is extensive overlap of clinical symptoms observed among children with bipolar mood disorder (BMD) and those with attention deficit hyperactivity disorder (ADHD). Thus, diagnosis according to clinical symptoms cannot be very accurate. It is therefore desirable to develop quantitative criteria for automatic discrimination between these disorders. This study is aimed at designing an efficient decision maker to accurately classify ADHD and BMD patients by analyzing their electroencephalogram (EEG) signals. In this study, 22 channels of EEGs have been recorded from 21 subjects with ADHD and 22 individuals with BMD. Several informative features, such as fractal dimension, band power and autoregressive coefficients, were extracted from the recorded signals. Considering the multimodal overlapping distribution of the obtained features, linear discriminant analysis (LDA) was used to reduce the input dimension in a more separable space to make it more appropriate for the proposed classifier. A piecewise linear classifier based on the extended classifier system for function approximation (XCSF) was modified by developing an adaptive mutation rate, which was proportional to the genotypic content of best individuals and their fitness in each generation. The proposed operator controlled the trade-off between exploration and exploitation while maintaining the diversity in the classifier's population to avoid premature convergence. To assess the effectiveness of the proposed scheme, the extracted features were applied to support vector machine, LDA, nearest neighbor and XCSF classifiers. To evaluate the method, a noisy environment was simulated with different noise amplitudes. It is shown that the results of the proposed technique are more robust as compared to conventional classifiers. Statistical tests demonstrate that the proposed classifier is a promising method for discriminating between ADHD and BMD patients.

  15. Improving vehicle adaptability to the operating conditions of «smart» cities in the northern regions

    Directory of Open Access Journals (Sweden)

    Anisimov Ilya

    2016-01-01

    Full Text Available The paper reviews a relevant problem of providing a higher quality of people’s living in the northern regions by the application of the modern technologies within transport in order to improve its environmental performance and efficiency. The aim of the research is to substantiate methods of increasing the adaptability of vehicles to variable low-temperature operating conditions based on a neural control system of preheating and maintaining the optimum temperature of technological fluids by SHF radiation and improving diesel fuel properties by introducing a multifunctional additive. It has been found that SHF radiation influences the physical and chemical parameters of diesel fuel, as well as the engine output parameters. SHF radiation results in a reduction of fuel consumption to 7%, smoke from the exhaust to 15%, and nitrogen oxide emission to 30%. A conclusion is made that using SHF radiation for technological fuel preheating is essential. An approach has been developed that improves low-temperature properties of diesel fuels and increases engine operation efficiency under severe climatic conditions by introducing a multifunctional additive. The additive will enable a significant decrease in fuel consumption under low-temperature operating conditions and a complex improvement of fuel properties.

  16. A new CT system architecture for high temporal resolution with applications to improved geometric dose efficiency and sparse sampling

    Science.gov (United States)

    Besson, G. M.

    2015-03-01

    A new scalable CT system architecture is introduced with the potential to achieve much higher temporal resolution than is possible with current CT designs while maintaining the flux per rotation near today's levels. Higher effective rotation speeds can be achieved leveraging today's x-ray tube designs and capabilities. The new CT architecture comprises the following elements: (1) decoupling of the source rotation from the detector rotation through the provision of two independent, coaxial and coplanar rotating gantries (drums); (2) observation of a source at a range of azimuthal angles with respect to a given detector cell; (3) utilization of a multiplicity of x-ray sources; (4) use of a wide-angle iso-centered detector mounted on the independent detector drum; (5) the detector drum presents a wide angular aperture allowing x-rays from the various sources to pass through, with the active detector cells occupying about 240-degrees in one configuration, and the wide aperture the complementary 120-degrees; (6) anti-scatter grids with absorbing lamellas oriented substantially parallel to the main gantry plane; (7) optional sparse view acquisition in "bunches," a unique sparse sampling pattern potentially enabling further data acquisition speed-up for specific applications. Temporal resolution gains are achieved when multiple sources are simultaneously in view of the extended detector. Accurate data acquisition then relies on multiplexing in space, time, or spectra. Thus the use of an energy-discriminating detector, such as a photon-counting detector, and of tube pulsing will be advantageous. Volume-based scatter correction methods have the potential to apply when space multiplexing is used.

  17. Neural-network-based adaptive UPFC for improving transient stability performance of power system.

    Science.gov (United States)

    Mishra, Sukumar

    2006-03-01

    This paper uses the recently proposed H(infinity)-learning method, for updating the parameter of the radial basis function neural network (RBFNN) used as a control scheme for the unified power flow controller (UPFC) to improve the transient stability performance of a multimachine power system. The RBFNN uses a single neuron architecture whose input is proportional to the difference in error and the updating of its parameters is carried via a proportional value of the error. Also, the coefficients of the difference of error, error, and auxiliary signal used for improving damping performance are depicted by a genetic algorithm. The performance of the newly designed controller is evaluated in a four-machine power system subjected to different types of disturbances. The newly designed single-neuron RBFNN-based UPFC exhibits better damping performance compared to the conventional PID as well as the extended Kalman filter (EKF) updating-based RBFNN scheme, making the unstable cases stable. Its simple architecture reduces the computational burden, thereby making it attractive for real-time implementation. Also, all the machines are being equipped with the conventional power system stabilizer (PSS) to study the coordinated effect of UPFC and PSS in the system. PMID:16566472

  18. Coping with drought: stress and adaptive responses in potato and perspectives for improvement.

    Science.gov (United States)

    Obidiegwu, Jude E; Bryan, Glenn J; Jones, Hamlyn G; Prashar, Ankush

    2015-01-01

    Potato (Solanum tuberosum L.) is often considered as a drought sensitive crop and its sustainable production is threatened due to frequent drought episodes. There has been much research aiming to understand the physiological, biochemical, and genetic basis of drought tolerance in potato as a basis for improving production under drought conditions. The complex phenotypic response of potato plants to drought is conditioned by the interactive effects of the plant's genotypic potential, developmental stage, and environment. Effective crop improvement for drought tolerance will require the pyramiding of many disparate characters, with different combinations being appropriate for different growing environments. An understanding of the interaction between below ground water uptake by the roots and above ground water loss from the shoot system is essential. The development of high throughput precision phenotyping platforms is providing an exciting new tool for precision screening, which, with the incorporation of innovative screening strategies, can aid the selection and pyramiding of drought-related genes appropriate for specific environments. Outcomes from genomics, proteomics, metabolomics, and bioengineering advances will undoubtedly compliment conventional breeding strategies and presents an alternative route toward development of drought tolerant potatoes. This review presents an overview of past research activity, highlighting recent advances with examples from other crops and suggesting future research directions.

  19. Coping with drought: Stress and adaptive responses in potato and perspectives for improvement

    Directory of Open Access Journals (Sweden)

    Jude E Obidiegwu

    2015-07-01

    Full Text Available Potato (Solanum tuberosum L. is often considered as a drought sensitive crop and its sustainable production is threatened due to frequent drought episodes. There has been much research aiming to understand the physiological, biochemical and genetic basis of drought tolerance in potato as a basis for improving production under drought conditions. The complex phenotypic response of potato plants to drought is conditioned by the interactive effects of the plant's genotypic potential, developmental stage and environment. Effective crop improvement for drought tolerance will require the pyramiding of many disparate characters, with different combinations being appropriate for different growing environments. An understanding of the interaction between below ground water uptake by the roots and above ground water loss from the shoot system is essential. The development of high throughput precision phenotyping platforms is providing an exciting new tool for precision screening, which, with the incorporation of innovative screening strategies, can aid the selection and pyramiding of drought-related genes appropriate for specific environments. Outcomes from genomics, proteomics, metabolomics and bioengineering advances will undoubtedly compliment conventional breeding strategies and presents an alternative route towards development of drought tolerant potatoes. This review presents an overview of past research activity, highlighting recent advances with examples from other crops and suggesting future research directions.

  20. Speed endurance training is a powerful stimulus for physiological adaptations and performance improvements of athletes.

    Science.gov (United States)

    Iaia, F M; Bangsbo, J

    2010-10-01

    The present article reviews the physiological and performance effects of speed endurance training consisting of exercise bouts at near maximal intensities in already trained subjects. Despite a reduction in training volume, speed endurance training of endurance-trained athletes can maintain the oxidative capacity and improve intense short-duration/repeated high-intensity exercise performance lasting 30 s to 4 min, as it occurs in a number of sports. When combined with a basic volume of training including some aerobic high-intensity sessions, speed endurance training is also useful in enhancing performance during longer events, e.g. 40 K cycling and 10 K running. Athletes in team sports involving intense exercise actions and endurance aspects can also benefit from performing speed endurance training. These improvements don't appear to depend on changes in maximum oxygen uptake (VO2max), muscle substrate levels, glycolytic and oxidative enzymes activity, and membrane transport proteins involved in pH regulation. Instead they appear to be related to a reduced energy expenditure during submaximal exercise and a higher expression of muscle Na(+) ,K(+) pump α-subunits, which via a higher Na(+) ,K(+) pump activity during exercise may delay fatigue development during intense exercise. In conclusion, athletes from disciplines involving periods of intense exercise can benefit from the inclusion of speed endurance sessions in their training programs.

  1. Temporal sensitivity. [time dependent human perception of visual stimuli

    Science.gov (United States)

    Watson, Andrew B.

    1986-01-01

    Human visual temporal sensitivity is examined. The stimuli used to measure temporal sensitivity are described and the linear systems theory is reviewed in terms of temporal sensitivity. A working model which represents temporal sensitivity is proposed. The visibility of a number of temporal wave forms, sinusoids, rectangular pulses, and pulse pairs, is analyzed. The relation between spatial and temporal effects is studied. Temporal variations induced by image motion and the effects of light adaptation on temporal sensitivity are considered.

  2. An improved self-calibration approach based on adaptive genetic algorithm for position-based visual servo

    Institute of Scientific and Technical Information of China (English)

    Ding LIU; Xiongjun WU; Yanxi YANG

    2008-01-01

    An improved self-calibrating algorithm for visual servo based on adaptive genetic algorithm is proposed in this paper.Our approach introduces an extension of Mendonca-Cipolla and G.Chesi's self-calibration for the positionbased visual servo technique which exploits the singular value property of the essential matrix.Specifically,a suitable dynamic online cost function is generated according to the property of the three singular values.The visual servo process is carried out simultaneous to the dynamic self-calibration,and then the cost function is minirmzed using the adaptive genetic algorithm instead of the gradient descent method in G.Chesi's approach.Moreover,this method overcomes the limitation that the initial parameters must be selected close to the true value,which is not constant in many cases.It is not necessary to know exactly the camera intrinsic parameters when using our approach,instead,coarse coding bounds ot the five parameters are enough for the algorithm,which can be done once and for all off-line.Besides,this algorithm does not require knowledge of the 3D model of the object.Simulation experiments are carried out and the results demonstrate that the proposed approach provides a fast convergence speed and robustness against unpredictable perturbalaons of camera parameters,and it is an effective and efficient visual scrvo algorithm.

  3. Improving Naive Bayes with Online Feature Selection for Quick Adaptation to Evolving Feature Usefulness

    Energy Technology Data Exchange (ETDEWEB)

    Pon, R K; Cardenas, A F; Buttler, D J

    2007-09-19

    The definition of what makes an article interesting varies from user to user and continually evolves even for a single user. As a result, for news recommendation systems, useless document features can not be determined a priori and all features are usually considered for interestingness classification. Consequently, the presence of currently useless features degrades classification performance [1], particularly over the initial set of news articles being classified. The initial set of document is critical for a user when considering which particular news recommendation system to adopt. To address these problems, we introduce an improved version of the naive Bayes classifier with online feature selection. We use correlation to determine the utility of each feature and take advantage of the conditional independence assumption used by naive Bayes for online feature selection and classification. The augmented naive Bayes classifier performs 28% better than the traditional naive Bayes classifier in recommending news articles from the Yahoo! RSS feeds.

  4. Improvements and adaptive changes to the fuel channel fitness-for-service assessment process

    International Nuclear Information System (INIS)

    The first formal Fitness-for-Service (FFS) assessment methodology in the CANDU industry was issued to the AECB in 1991 in the CANDU Pressure Tube Fitness-for-Service Guidelines (FFSG), which were later incorporated into CSA N285.8 in the mid 1990s. While the utilities have continued to benefit greatly from repeated, successful FFS assessments, industry changes since 1991 have conspired to apply mounting pressures on the FFS community, to the potential detriment of the assessment process. This paper identifies inherent challenges, historical challenges, and more recent difficulties encountered by the FFS assessment community and gives recommendations for relieving some of the mounting pressures on the FFS assessors and for improving the FFS assessment process. (author)

  5. Improving Spatial Adaptivity of Nonlocal Means in Low-Dosed CT Imaging Using Pointwise Fractal Dimension

    Directory of Open Access Journals (Sweden)

    Xiuqing Zheng

    2013-01-01

    box-counting dimension (PWBCD, is computed for each image pixel. PWBCD uses a fixed size local window centered at the considered image pixel to fit the different local structures of images. Then based on PWBCD, a new method that uses PWBCD to improve SA of NLMs directly is proposed. That is, PWBCD is combined with the weight of the difference between local comparison windows for NLMs. Smoothing results for test images and real sinograms show that PWBCD-NLMs with well-chosen parameters can preserve anatomical features better while suppressing the noises efficiently. In addition, PWBCD-NLMs also has better performance both in visual quality and peak signal to noise ratio (PSNR than NLMs in LDCT imaging.

  6. Assessing the effectiveness and cost effectiveness of adaptive e-Learning to improve dietary behaviour: protocol for a systematic review

    Directory of Open Access Journals (Sweden)

    Michie Susan

    2010-04-01

    Full Text Available Abstract Background The composition of habitual diets is associated with adverse or protective effects on aspects of health. Consequently, UK public health policy strongly advocates dietary change for the improvement of population health and emphasises the importance of individual empowerment to improve health. A new and evolving area in the promotion of dietary behavioural change is e-Learning, the use of interactive electronic media to facilitate teaching and learning on a range of issues, including diet and health. The aims of this systematic review are to determine the effectiveness and cost-effectiveness of adaptive e-Learning for improving dietary behaviours. Methods/Design The research will consist of a systematic review and a cost-effectiveness analysis. Studies will be considered for the review if they are randomised controlled trials, involving participants aged 13 or over, which evaluate the effectiveness or efficacy of interactive software programmes for improving dietary behaviour. Primary outcome measures will be those related to dietary behaviours, including estimated intakes of energy, nutrients and dietary fibre, or the estimated number of servings per day of foods or food groups. Secondary outcome measures will be objective clinical measures that are likely to respond to changes in dietary behaviours, such as anthropometry or blood biochemistry. Knowledge, self-efficacy, intention and emotion will be examined as mediators of dietary behaviour change in order to explore potential mechanisms of action. Databases will be searched using a comprehensive four-part search strategy, and the results exported to a bibliographic database. Two review authors will independently screen results to identify potentially eligible studies, and will independently extract data from included studies, with any discrepancies at each stage settled by a third author. Standardised forms and criteria will be used. A descriptive analysis of included

  7. Improving the spatial and temporal resolution with quantification of uncertainty and errors in earth observation data sets using Data Interpolating Empirical Orthogonal Functions methodology

    Science.gov (United States)

    El Serafy, Ghada; Gaytan Aguilar, Sandra; Ziemba, Alexander

    2016-04-01

    There is an increasing use of process-based models in the investigation of ecological systems and scenario predictions. The accuracy and quality of these models are improved when run with high spatial and temporal resolution data sets. However, ecological data can often be difficult to collect which manifests itself through irregularities in the spatial and temporal domain of these data sets. Through the use of Data INterpolating Empirical Orthogonal Functions(DINEOF) methodology, earth observation products can be improved to have full spatial coverage within the desired domain as well as increased temporal resolution to daily and weekly time step, those frequently required by process-based models[1]. The DINEOF methodology results in a degree of error being affixed to the refined data product. In order to determine the degree of error introduced through this process, the suspended particulate matter and chlorophyll-a data from MERIS is used with DINEOF to produce high resolution products for the Wadden Sea. These new data sets are then compared with in-situ and other data sources to determine the error. Also, artificial cloud cover scenarios are conducted in order to substantiate the findings from MERIS data experiments. Secondly, the accuracy of DINEOF is explored to evaluate the variance of the methodology. The degree of accuracy is combined with the overall error produced by the methodology and reported in an assessment of the quality of DINEOF when applied to resolution refinement of chlorophyll-a and suspended particulate matter in the Wadden Sea. References [1] Sirjacobs, D.; Alvera-Azcárate, A.; Barth, A.; Lacroix, G.; Park, Y.; Nechad, B.; Ruddick, K.G.; Beckers, J.-M. (2011). Cloud filling of ocean colour and sea surface temperature remote sensing products over the Southern North Sea by the Data Interpolating Empirical Orthogonal Functions methodology. J. Sea Res. 65(1): 114-130. Dx.doi.org/10.1016/j.seares.2010.08.002

  8. [Adaptability of Helianthus annuus seedlings to crude oil pollution in soil and its improvement measures under salinization stress].

    Science.gov (United States)

    Zhang, Jing-lei; Ci, Hua-cong; He, Xing-dong; Liang, Yu-ting; Zhao, Xuan; Sun, Hui-ting; Xie, Hong-tao

    2015-11-01

    To explore the adaptability of plant under salt stress to crude oil pollution of soil and improvement measures, a pot experiment of Helianthus annuus seedlings was conducted using orthogonal experiment method with crude oil-sodium chloride-desulfurization gypsum and cinder-zeolite-desulfurization gypsum-sawdust. The results showed that, with the increase of soil crude oil concentration, the relative growth rate (RGR) of plant height, RGR of aboveground biomass and root N: P ratios of H. annuus seedlings decreased significantly, while the activity of SOD and CAT increased at first and then decreased significantly. The RGR of plant height and aboveground biomass significantly increased (P oil pollution of soil could decrease the relative growth rate of H. annuus seedling, and sawdust could reduce the influence of crude oil pollution on plant growth under salt stress. PMID:26915209

  9. [Adaptability of Helianthus annuus seedlings to crude oil pollution in soil and its improvement measures under salinization stress].

    Science.gov (United States)

    Zhang, Jing-lei; Ci, Hua-cong; He, Xing-dong; Liang, Yu-ting; Zhao, Xuan; Sun, Hui-ting; Xie, Hong-tao

    2015-11-01

    To explore the adaptability of plant under salt stress to crude oil pollution of soil and improvement measures, a pot experiment of Helianthus annuus seedlings was conducted using orthogonal experiment method with crude oil-sodium chloride-desulfurization gypsum and cinder-zeolite-desulfurization gypsum-sawdust. The results showed that, with the increase of soil crude oil concentration, the relative growth rate (RGR) of plant height, RGR of aboveground biomass and root N: P ratios of H. annuus seedlings decreased significantly, while the activity of SOD and CAT increased at first and then decreased significantly. The RGR of plant height and aboveground biomass significantly increased (P cinder, zeolite, desulfurization gypsum under salinization condition. The crude oil pollution of soil could decrease the relative growth rate of H. annuus seedling, and sawdust could reduce the influence of crude oil pollution on plant growth under salt stress.

  10. The Life History of Flabellula baltica Smirnov (Gymnamoebae, Rhizopoda): Adaptations to a Spatially and Temporally Heterogeneous Environment

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2010-01-01

    The polymorphic life history of the marine naked amoeba Flabellula baltica was studied. It can be interpreted in terms of adaptations to an environment that is patchy in time and space and it represents trade-off between longevity during starvation and the ability to initiate multiplication soon...

  11. Improving the scalability of hyperspectral imaging applications on heterogeneous platforms using adaptive run-time data compression

    Science.gov (United States)

    Plaza, Antonio; Plaza, Javier; Paz, Abel

    2010-10-01

    Latest generation remote sensing instruments (called hyperspectral imagers) are now able to generate hundreds of images, corresponding to different wavelength channels, for the same area on the surface of the Earth. In previous work, we have reported that the scalability of parallel processing algorithms dealing with these high-dimensional data volumes is affected by the amount of data to be exchanged through the communication network of the system. However, large messages are common in hyperspectral imaging applications since processing algorithms are pixel-based, and each pixel vector to be exchanged through the communication network is made up of hundreds of spectral values. Thus, decreasing the amount of data to be exchanged could improve the scalability and parallel performance. In this paper, we propose a new framework based on intelligent utilization of wavelet-based data compression techniques for improving the scalability of a standard hyperspectral image processing chain on heterogeneous networks of workstations. This type of parallel platform is quickly becoming a standard in hyperspectral image processing due to the distributed nature of collected hyperspectral data as well as its flexibility and low cost. Our experimental results indicate that adaptive lossy compression can lead to improvements in the scalability of the hyperspectral processing chain without sacrificing analysis accuracy, even at sub-pixel precision levels.

  12. Adaptable Design Improvements for Electromagnetic Shock Wave Lithotripters and Techniques for Controlling Cavitation

    Science.gov (United States)

    Smith, Nathan Birchard

    In this dissertation work, the aim was to garner better mechanistic understanding of how shock wave lithotripsy (SWL) breaks stones in order to guide design improvements to modern electromagnetic (EM) shock wave lithotripters. To accomplish this goal, experimental studies were carefully designed to isolate mechanisms of fragmentation, and models for wave propagation, fragmentation, and stone motion were developed. In the initial study, a representative EM lithotripter was characterized and tested for in vitro stone comminution efficiency at a variety of field positions and doses using phantom kidney stones of variable physical properties, and in different fluid mediums to isolate the contribution of cavitation. Through parametric analysis of the acoustic field measurements alongside comminution results, a logarithmic correlation was determined between average peak pressure incident on the stone surface and comminution efficiency. It was also noted that for a given stone type, the correlations converged to an average peak pressure threshold for fragmentation, independent of fluid medium in use. The correlation of average peak pressure to efficacy supports the rationale for the acoustic lens modifications, which were pursued to simultaneously enhance beam width and optimize the pulse profile of the lithotripter shock wave (LSW) via in situ pulse superposition for improved stone fragmentation by stress waves and cavitation, respectively. In parallel, a numerical model for wave propagation was used to investigate the variations of critical parameters with changes in lens geometry. A consensus was reached on a new lens design based on high-speed imaging and stone comminution experiments against the original lens at a fixed acoustic energy setting. The results have demonstrated that the new lens has improved efficacy away from the focus, where stones may move due to respiration, fragmentation, acoustic radiation forces, or voluntary patient movements. Using the

  13. Use of satellite data to improve parameterization of spatial and temporal variations of gaseous dry deposition in regional-scale models

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Weigang; Wesely, M.L.

    1994-01-01

    The removal of gaseous substances from the atmosphere by dry deposition represents an important sink in the atmospheric budget for many trace gases. The surface removal rate, therefore, needs be described quantitatively in modeling atmospheric transport and chemistry with regional- and global-scale models. Because the uptake capability of a terrestrial surface is strongly influenced by the type and condition of its vegetation, the seasonal and spatial changes in vegetation should be described in considerable detail in large-scale models. The objective of the present study is to develop a model that links remote sensing data from satellites with the RADM dry deposition module to provide a parameterization of dry deposition over large scales with improved temporal and spatial coverage. This paper briefly discusses the modeling methods and initial results obtained by applying the improved dry deposition module to a tallgrass prairie, for which measurements of O{sub 3} dry deposition and simultaneously obtained satellite remote sensing data are available.

  14. Self-Adaptive Strategy Based on Fuzzy Control Systems for Improving Performance in Wireless Sensors Networks

    Directory of Open Access Journals (Sweden)

    Vicente Hernández Díaz

    2015-09-01

    Full Text Available The solutions to cope with new challenges that societies have to face nowadays involve providing smarter daily systems. To achieve this, technology has to evolve and leverage physical systems automatic interactions, with less human intervention. Technological paradigms like Internet of Things (IoT and Cyber-Physical Systems (CPS are providing reference models, architectures, approaches and tools that are to support cross-domain solutions. Thus, CPS based solutions will be applied in different application domains like e-Health, Smart Grid, Smart Transportation and so on, to assure the expected response from a complex system that relies on the smooth interaction and cooperation of diverse networked physical systems. The Wireless Sensors Networks (WSN are a well-known wireless technology that are part of large CPS. The WSN aims at monitoring a physical system, object, (e.g., the environmental condition of a cargo container, and relaying data to the targeted processing element. The WSN communication reliability, as well as a restrained energy consumption, are expected features in a WSN. This paper shows the results obtained in a real WSN deployment, based on SunSPOT nodes, which carries out a fuzzy based control strategy to improve energy consumption while keeping communication reliability and computational resources usage among boundaries.

  15. Self-Adaptive Strategy Based on Fuzzy Control Systems for Improving Performance in Wireless Sensors Networks.

    Science.gov (United States)

    Hernández Díaz, Vicente; Martínez, José-Fernán; Lucas Martínez, Néstor; del Toro, Raúl M

    2015-09-18

    The solutions to cope with new challenges that societies have to face nowadays involve providing smarter daily systems. To achieve this, technology has to evolve and leverage physical systems automatic interactions, with less human intervention. Technological paradigms like Internet of Things (IoT) and Cyber-Physical Systems (CPS) are providing reference models, architectures, approaches and tools that are to support cross-domain solutions. Thus, CPS based solutions will be applied in different application domains like e-Health, Smart Grid, Smart Transportation and so on, to assure the expected response from a complex system that relies on the smooth interaction and cooperation of diverse networked physical systems. The Wireless Sensors Networks (WSN) are a well-known wireless technology that are part of large CPS. The WSN aims at monitoring a physical system, object, (e.g., the environmental condition of a cargo container), and relaying data to the targeted processing element. The WSN communication reliability, as well as a restrained energy consumption, are expected features in a WSN. This paper shows the results obtained in a real WSN deployment, based on SunSPOT nodes, which carries out a fuzzy based control strategy to improve energy consumption while keeping communication reliability and computational resources usage among boundaries.

  16. An adapted purification procedure to improve the quality of {sup 90}Y for clinical use

    Energy Technology Data Exchange (ETDEWEB)

    Xiques Castillo, A.; Olive, K. Isaac; Casanova Gonzalez, E.; Beckford, D.; Leyva Montana, R.; Olive Alvare, E. [Centro dc Isotopos (CENTIS), La Habana (Cuba); Montero Alvarez, A. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear, La Habana (Cuba)

    2009-07-01

    There is an increasing interest for {sup 90}Y for radionuclide therapy. However, radioimmunotherapy, one of the most important applications for {sup 90}Y, demands a very high purity product. Obtaining a high quality {sup 90}Y is difficult not only because of the complex and time consuming production schemes but also because of the quality control which has challenging tasks like the determination of {sup 90}Sr at very low concentrations. The present paper investigates a reported purification procedure for the removal of stable metal trace contaminants from an {sup 90}Y solution, seeking for its potential use in the elimination of the radioactive contaminant {sup 90}Sr and its fast determination. For this purpose a washing step with HNO{sub 3} acid is introduced to elute {sup 90}Sr, the order of each acid solution is rearranged to reduce the potential contaminants present in acids and the size of the column is reduced to further optimize the procedure. As a result, an improved purification method is obtained, which allows the removal of both trace metal contaminants and {sup 90}Sr from an {sup 90}Y solution and the measurement of {sup 90}Sr/{sup 90}Y ratios of the order of 10{sup -7}, which are well below the established pharmacopeia limit of 2 x 10{sup -5}. (orig.)

  17. Improving Intensive Care Unit and Ward Utilization by Adapting Master Surgery Schedules.

    Science.gov (United States)

    Fügener, Andreas; Edenharter, Guenther Michael; Kiefer, Paskal; Mayr, Ulrike; Schiele, Julian; Steiner, Fabian; Kolisch, Rainer; Blobner, Manfred

    2016-03-15

    With increasing organizational and financial pressure on hospitals, each individual surgical treatment has to be reviewed and planned thoroughly. Apart from the expensive operating room facilities, proper staffing and planning of downstream units, like the wards or the intensive care units (ICUs), should be considered as well. In this article, we outline the relationship between a master surgery schedule (MSS), i.e., the assignment of surgical blocks to medical specialties, and the bed demand in the downstream units using an analytical model. By using historical data retrieved from the clinical information system and a patient flow model, we applied a recently developed algorithm for predicting bed demand based on the MSSs for patients of 3 surgical subspecialties of a hospital. Simulations with 3 different MSSs were performed. The impact on the required amount of beds in the downstream units was analyzed. We show the potential improvements of the current MSS considering 2 main goals: leveling workload among days and reduction of weekend utilization. We discuss 2 different MSSs, one decreasing the weekend ICU utilization by 20% and the other one reducing maximum ward bed demand by 7%. A test with 12 months of real-life data validates the results. The application of the algorithm provides detailed insights for the hospital into the impact of MSS designs on the bed demand in downstream units. It allowed creating MSSs that avoid peaks in bed demand and high weekend occupancy levels in the ICU and the ward.

  18. Near real-time monitoring systems for adaptive management and improved forest governance

    Science.gov (United States)

    Musinsky, J.; Tabor, K.; Cano, A.

    2012-12-01

    The destruction and degradation of the world's forests from deforestation, illegal logging and fire has wide-ranging environmental and economic impacts, including biodiversity loss, the degradation of ecosystem services and the emission of greenhouse gases. In an effort to strengthen local capacity to respond to these threats, Conservation International has developed a suite of near real-time satellite monitoring systems generating daily alerts, maps and reports of forest fire, fire risk, deforestation and degradation that are used by national and sub-national government agencies, NGO's, scientists, communities, and the media to respond to and report on threats to forest resources. Currently, the systems support more than 1000 subscribers from 45 countries, focusing on Madagascar, Indonesia, Bolivia and Peru. This presentation will explore the types of innovative applications users have found for these data, challenges they've encountered in data acquisition and accuracy, and feedback they've given on the usefulness of these systems for REDD+ implementation, protected areas management and improved forest governance.;

  19. Improved Adaptive Droop Control Design for Optimal Power Sharing in VSC-MTDC Integrating Wind Farms

    Directory of Open Access Journals (Sweden)

    Xiaohong Ran

    2015-07-01

    Full Text Available With the advance of insulated gate bipolar transistor (IGBT converters, Multi-Terminal DC (MTDC based on the voltage-source converter (VSC has developed rapidly in renewable and electric power systems. To reduce the copper loss of large capacity and long distance DC transmission line, an improved droop control design based on optimal power sharing in VSC-MTDC integrating offshore wind farm is proposed. The proposed approach provided a calculation method for power-voltage droop coefficients under two different scenarios either considering local load or not. The available headroom of each converter station was considered as a converter outage, to participate in the power adjustment according to their ability. A four-terminal MTDC model system including two large scale wind farms was set up in PSCAD/EMTDC. Then, the proposed control strategy was verified through simulation under the various conditions, including wind speed variation, rectifier outage and inverter outage, and a three-phase short-circuit of the converter.

  20. Self-Adaptive Strategy Based on Fuzzy Control Systems for Improving Performance in Wireless Sensors Networks.

    Science.gov (United States)

    Hernández Díaz, Vicente; Martínez, José-Fernán; Lucas Martínez, Néstor; del Toro, Raúl M

    2015-01-01

    The solutions to cope with new challenges that societies have to face nowadays involve providing smarter daily systems. To achieve this, technology has to evolve and leverage physical systems automatic interactions, with less human intervention. Technological paradigms like Internet of Things (IoT) and Cyber-Physical Systems (CPS) are providing reference models, architectures, approaches and tools that are to support cross-domain solutions. Thus, CPS based solutions will be applied in different application domains like e-Health, Smart Grid, Smart Transportation and so on, to assure the expected response from a complex system that relies on the smooth interaction and cooperation of diverse networked physical systems. The Wireless Sensors Networks (WSN) are a well-known wireless technology that are part of large CPS. The WSN aims at monitoring a physical system, object, (e.g., the environmental condition of a cargo container), and relaying data to the targeted processing element. The WSN communication reliability, as well as a restrained energy consumption, are expected features in a WSN. This paper shows the results obtained in a real WSN deployment, based on SunSPOT nodes, which carries out a fuzzy based control strategy to improve energy consumption while keeping communication reliability and computational resources usage among boundaries. PMID:26393612

  1. Awareness of temporal lag is necessary for motor–visual temporal recalibration

    Directory of Open Access Journals (Sweden)

    Masaki eTsujita

    2016-01-01

    Full Text Available Consistent exposure to a temporal lag between observers’ voluntary action and its visual feedback induced recalibration of temporal order perception between a motor action and a visual stimulus. It remains unclear what kinds of processing underlie this motor–visual temporal recalibration. This study examined the necessity of motor–visual temporal recalibration for awareness of a temporal lag between a motor action and its visual feedback. In Experiment 1, we allocated observers to either the multiple-step or single-step lag conditions. In the multiple-step lag condition, we first inserted a small temporal lag and subsequently increased it with progress of the adaptation period, to make observers unaware of the temporal lag during the adaptation period. In the single-step lag condition, we instructed observers about the temporal lag before adaptation, and inserted a substantial temporal lag from the beginning of the adaptation period to ensure that they were aware of the temporal lag. We found significant recalibration only in the single-step lag condition. In Experiment 2, we exposed all observers to a substantial temporal lag from the beginning of adaptation period with no instruction about insertion of the temporal lag. We asked observers at the end of the experiment whether they were aware of the temporal lag. We found significant recalibration for only observers who were aware of the lag. These results suggest that awareness of the temporal lag plays a crucial role in motor–visual temporal recalibration.

  2. Bottleneck Prediction Method Based on Improved Adaptive Network-based Fuzzy Inference System (ANFIS) in Semiconductor Manufacturing System%Bottleneck Prediction Method Based on Improved Adaptive Network-based Fuzzy Inference System (ANFIS) in Semiconductor Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    曹政才; 邓积杰; 刘民; 王永吉

    2012-01-01

    Semiconductor manufacturing (SM) system is one of the most complicated hybrid processes involved continuously variable dynamical systems and discrete event dynamical systems. The optimization and scheduling of semiconductor fabrication has long been a hot research direction in automation. Bottleneck is the key factor to a SM system, which seriously influences the throughput rate, cycle time, time-delivery rate, etc. Efficient prediction for the bottleneck of a SM system provides the best support for the consequent scheduling. Because categorical data (product types, releasing strategies) and numerical data (work in process, processing time, utilization rate, buffer length, etc.) have significant effect on bottleneck, an improved adaptive network-based fuzzy inference system (ANFIS) was adopted in this study to predict bottleneck since conventional neural network-based methods accommodate only numerical inputs. In this improved ANFIS, the contribution of categorical inputs to firing strength is reflected through a transformation matrix. In order to tackle high-dimensional inputs, reduce the number of fuzzy rules and obtain high prediction accuracy, a fuzzy c-means method combining binary tree linear division method was applied to identify the initial structure of fuzzy inference system. According to the experimental results, the main-bottleneck and sub-bottleneck of SM system can be predicted accurately with the proposed method.

  3. An adaptive threshold method for improving astrometry of space debris CCD images

    Science.gov (United States)

    Sun, Rong-yu; Zhao, Chang-yin

    2014-06-01

    Optical survey is a main technique for observing space debris, and precisely measuring the positions of space debris is of great importance. Due to several factors, e.g. the angle object normal to the observer, the shape as well as the attitude of the object, the variations of observed characteristics for low earth orbital space debris are distinct. When we look at optical CCD images of observed objects, the size and brightness are varying, hence it’s difficult to decide the threshold during centroid measurement and precise astrometry. Traditionally the threshold is given empirically and constantly in data reduction, and obviously it’s not suitable for data reduction of space debris. Here we offer a solution to provide the threshold. Our method assumes that the PSF (point spread function) is Gaussian and estimates the signal flux by a directly two-dimensional Gaussian fit, then a cubic spline interpolation is performed to divide each initial pixel into several sub-pixels, at last the threshold is determined by the estimation of signal flux and the sub-pixels above threshold are separated to estimate the centroid. A trail observation of the fast spinning satellite Ajisai is made and the CCD frames are obtained to test our algorithm. The calibration precision of various threshold is obtained through the comparison between the observed equatorial position and the reference one, the latter are obtained from the precise ephemeris of the satellite. The results indicate that our method reduces the total errors of measurements, it works effectively in improving the centering precision of space debris images.

  4. The temporal window of ecological adaptation in postglacial lakes: a comparison of head morphology, trophic position and habitat use in Norwegian threespine stickleback populations

    OpenAIRE

    Østbye, Kjartan; Harrod, Chris; Gregersen, Finn; Klepaker, Tom; Schulz, Michael; Schluter, Dolph; Vøllestad, Leif A

    2016-01-01

    Background Studying how trophic traits and niche use are related in natural populations is important in order to understand adaptation and specialization. Here, we describe trophic trait diversity in twenty-five Norwegian freshwater threespine stickleback populations and their putative marine ancestor, and relate trait differences to postglacial lake age. By studying lakes of different ages, depths and distance to the sea we examine key environmental variables that may pred...

  5. Adaptability Research of Spatial and Temporal Remote Sensing Data Fusion Technology in Crop Monitoring%遥感数据时空融合技术在农作物监测中的适应性研究

    Institute of Scientific and Technical Information of China (English)

    蔡德文; 牛铮; 王力

    2012-01-01

    受卫星回访周期及云的影响,大范围研究区同一时期的Landsat卫星数据很难获取,因而国内外学者提出了遥感影像时空融合技术。以石河子为实验区,利用STARFM(SpatialandTempo—ralAdaptiveReflectanceFusionModel)模型融合生成了高时空分辨率TM影像,对不同作物类型真实反射率与融合影像反射率作相关性分析,分析了遥感数据时空融合技术在新疆农作物监测中的适用性。结果表明:利用STARFM模型模拟得到的融合影像与真实影像间的相关性较高,但当地物类型发生变化时,融合影像与真实影像间将存在明显的差异。地物类型变化作物融合影像反射率与真实影像反射率间的相关性较小。%The application of Landsat satellite image in crop-growth monitoring is limited by the 16-day re- visit cycle and frequent cloud contamination. One solution is to combine the high-spatial information of fine- resolution sensors,such as Landsat with the high-frequency temporal information of coarse-resolution sen- sors, Moderate Resolution Imaging Spectroradiometer(MODIS). In the present paper, we studied the adapt- ability of Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM), which is a spatial and temporal fusion technology in monitoring crop in Shihezi of Xinjiang Uygur Autonomous Region. We ana- lyzed the correlation between fusion result and observed data. The result showed that the correlation be- tween fusion image and real image was high, however, due to the change of land cover which did not meet the assumption of STARFM,and the differences were still significant, especially for the reflectance of fu- sion image and real image. The correlation between fusion image and real image was low, when feature type changes.

  6. Reduction of radiation exposure and improvement of image quality with BMI-adapted prospective cardiac computed tomography and iterative reconstruction

    International Nuclear Information System (INIS)

    Purpose: To assess the impact of body mass index (BMI)-adapted protocols and iterative reconstruction algorithms (iDose) on patient radiation exposure and image quality in patients undergoing prospective ECG-triggered 256-slice coronary computed tomography angiography (CCTA). Methods: Image quality and radiation exposure were systematically analyzed in 100 patients. 60 Patients underwent prospective ECG-triggered CCTA using a non-tailored protocol and served as a ‘control’ group (Group 1: 120 kV, 200 mA s). 40 Consecutive patients with suspected coronary artery disease (CAD) underwent prospective CCTA, using BMI-adapted tube voltage and standard (Group 2: 100/120 kV, 100–200 mA s) versus reduced tube current (Group 3: 100/120 kV, 75–150 mA s). Iterative reconstructions were provided with different iDose levels and were compared to filtered back projection (FBP) reconstructions. Image quality was assessed in consensus of 2 experienced observers and using a 5-grade scale (1 = best to 5 = worse), and signal- and contrast-to-noise ratios (SNR and CNR) were quantified. Results: CCTA was performed without adverse events in all patients (n = 100, heart rate of 47–87 bpm and BMI of 19–38 kg/m2). Patients examined using the non-tailored protocol in Group 1 had the highest radiation exposure (3.2 ± 0.4 mSv), followed by Group 2 (1.7 ± 0.7 mSv) and Group 3 (1.2 ± 0.6 mSv) (radiation savings of 47% and 63%, respectively, p < 0.001). Iterative reconstructions provided increased SNR and CNR, particularly when higher iDose level 5 was applied with Multi-Frequency reconstruction (iDose5 MFR) (14.1 ± 4.6 versus 21.2 ± 7.3 for SNR and 12.0 ± 4.2 versus 18.1 ± 6.6 for CNR, for FBP versus iDose5 MFR, respectively, p < 0.001). The combination of BMI adaptation with iterative reconstruction reduced radiation exposure and simultaneously improved image quality (subjective image quality of 1.4 ± 0.4 versus 1.9 ± 0.5 for Group 2 reconstructed using iDose5 MFR versus

  7. SPATIAL AND TEMPORAL DISTRIBUTION OF GROWTH FACTORS RECEPTORS IN THE CALLUS: IMPLICATIONS FOR IMPROVEMENT OF DISTRACTION OSTEOGENESIS

    OpenAIRE

    SIWICKA, KAROLINA A; Kitoh, Hiroshi; KAWASUMI, MOTOAKI; Ishiguro, Naoki

    2011-01-01

    ABSTRACT Management of bone deficits by distraction osteogenesis is an appreciated but lengthy procedure. To accelerate the consolidation of newly formed distraction callus, an administration of growth factors into the distraction gap has been suggested. Changes in expression of growth factors receptors in the distracted callus during consolidation were studied in order to improve our understanding of the underlying molecular mechanisms and to provide a scientific basis for clinical applicati...

  8. An Improved Adaptive Harmony Search Algorithm%混沌的自适应和声搜索算法

    Institute of Scientific and Technical Information of China (English)

    陈莹珍; 高岳林

    2011-01-01

    和声搜索算法是一种启发式优化算法,针对现有改进的和声搜索算法(IHS)的不足,提出了一种混沌自适应和声搜索算法(CAHS).在该算法中,首先采用混沌策略初始化种群,然后采用自适应的和声保留概率、音调调节概率和音调调节步长产生新解,每次迭代产生多个新解,充分利用和声记忆库的信息.如果算法停滞,则采用混沌变异机制.本文用5个标准的测试函数对该算法进行测试,结果表明该算法(CAHS)比IHS和AHSPSO算法有较强的寻优能力和跳出局部最优解的能力.%Harmony Search (HS) is a heuristic optimization method. For the purpose of avoiding the disadvantage of improved harmony search (IHS) algorithm, a new adaptive harmony search algorithm is presented. The algorithm utilizes chaos technique initializing population, adaptive harmony probability, and pitch adjusting frequency and bandwidth to produce new solutions. In each iteration, several solutions are generated so as to makes full use of information of harmony memory. If the algorithm arrives at stagnating state,chaos mutation is adopted in order to increase the diversity solutions. Finally, the proposed algorithm is tested by five benchmark function and compared with HIS, AHSPSO. The test results show the favorable abilities of accuracy and escaping local minimums.

  9. Improving thoracic four-dimensional cone-beam CT reconstruction with anatomical-adaptive image regularization (AAIR)

    Science.gov (United States)

    Shieh, Chun-Chien; Kipritidis, John; O'Brien, Ricky T.; Cooper, Benjamin J.; Kuncic, Zdenka; Keall, Paul J.

    2015-01-01

    Total-variation (TV) minimization reconstructions can significantly reduce noise and streaks in thoracic four-dimensional cone-beam computed tomography (4D CBCT) images compared to the Feldkamp-Davis-Kress (FDK) algorithm currently used in practice. TV minimization reconstructions are, however, prone to over-smoothing anatomical details and are also computationally inefficient. The aim of this study is to demonstrate a proof of concept that these disadvantages can be overcome by incorporating the general knowledge of the thoracic anatomy via anatomy segmentation into the reconstruction. The proposed method, referred as the anatomical-adaptive image regularization (AAIR) method, utilizes the adaptive-steepest-descent projection-onto-convex-sets (ASD-POCS) framework, but introduces an additional anatomy segmentation step in every iteration. The anatomy segmentation information is implemented in the reconstruction using a heuristic approach to adaptively suppress over-smoothing at anatomical structures of interest. The performance of AAIR depends on parameters describing the weighting of the anatomy segmentation prior and segmentation threshold values. A sensitivity study revealed that the reconstruction outcome is not sensitive to these parameters as long as they are chosen within a suitable range. AAIR was validated using a digital phantom and a patient scan and was compared to FDK, ASD-POCS and the prior image constrained compressed sensing (PICCS) method. For the phantom case, AAIR reconstruction was quantitatively shown to be the most accurate as indicated by the mean absolute difference and the structural similarity index. For the patient case, AAIR resulted in the highest signal-to-noise ratio (i.e. the lowest level of noise and streaking) and the highest contrast-to-noise ratios for the tumor and the bony anatomy (i.e. the best visibility of anatomical details). Overall, AAIR was much less prone to over-smoothing anatomical details compared to ASD-POCS and did

  10. Improving thoracic four-dimensional cone-beam CT reconstruction with anatomical-adaptive image regularization (AAIR)

    International Nuclear Information System (INIS)

    Total-variation (TV) minimization reconstructions can significantly reduce noise and streaks in thoracic four-dimensional cone-beam computed tomography (4D CBCT) images compared to the Feldkamp–Davis–Kress (FDK) algorithm currently used in practice. TV minimization reconstructions are, however, prone to over-smoothing anatomical details and are also computationally inefficient. The aim of this study is to demonstrate a proof of concept that these disadvantages can be overcome by incorporating the general knowledge of the thoracic anatomy via anatomy segmentation into the reconstruction. The proposed method, referred as the anatomical-adaptive image regularization (AAIR) method, utilizes the adaptive-steepest-descent projection-onto-convex-sets (ASD-POCS) framework, but introduces an additional anatomy segmentation step in every iteration. The anatomy segmentation information is implemented in the reconstruction using a heuristic approach to adaptively suppress over-smoothing at anatomical structures of interest. The performance of AAIR depends on parameters describing the weighting of the anatomy segmentation prior and segmentation threshold values. A sensitivity study revealed that the reconstruction outcome is not sensitive to these parameters as long as they are chosen within a suitable range. AAIR was validated using a digital phantom and a patient scan and was compared to FDK, ASD-POCS and the prior image constrained compressed sensing (PICCS) method. For the phantom case, AAIR reconstruction was quantitatively shown to be the most accurate as indicated by the mean absolute difference and the structural similarity index. For the patient case, AAIR resulted in the highest signal-to-noise ratio (i.e. the lowest level of noise and streaking) and the highest contrast-to-noise ratios for the tumor and the bony anatomy (i.e. the best visibility of anatomical details). Overall, AAIR was much less prone to over-smoothing anatomical details compared to ASD-POCS and

  11. Food crops face rising temperatures: An overview of responses, adaptive mechanisms, and approaches to improve heat tolerance

    Directory of Open Access Journals (Sweden)

    Neeru Kaushal

    2016-12-01

    Full Text Available The rising temperatures are resulting in heat stress for various agricultural crops to limit their growth, metabolism, and leading to significant loss of yield potential worldwide. Heat stress adversely affects normal plant growth and development depending on the sensitivity of each crop species. Each crop species has its own range of temperature maxima and minima at different developmental stages beyond which all these processes get inhibited. The reproductive stage is on the whole more sensitive to heat stress, resulting in impaired fertilization to cause abortion of flowers. During seed filling, heat stress retards seed growth by affecting all the biochemical events to reduce seed size. Unfavorable temperature may significantly affect photosynthesis, respiration, water balance, and membrane stability of leaves. To combat heat stress, plants acquire various defense mechanisms for their survival such as maintaining membrane stability, and scavenging reactive oxygen species by generating antioxidants and stress proteins. Thermo-tolerance can be improved by the accumulation of various compounds of low molecular mass known as thermo-protectants as well as phyto-hormones. Exogenous application of these molecules has benefited plants growing under heat stress. Alternatively, transgenic plants over-expressing the enzymes catalyzing the synthesis of these molecules may be raised to increase their endogenous levels to improve heat tolerance. In recent times, various transgenics have been developed with improved thermo-tolerance having potential benefits for inducing heat tolerance in food crops. Updated information about of the effects of heat stress on various food crops and their responses as well as adaptive mechanisms is reviewed here.

  12. Use of an allostatic neurotechnology by adolescents with postural orthostatic tachycardia syndrome (POTS) is associated with improvements in heart rate variability and changes in temporal lobe electrical activity.

    Science.gov (United States)

    Fortunato, John E; Tegeler, Catherine L; Gerdes, Lee; Lee, Sung W; Pajewski, Nicholas M; Franco, Meghan E; Cook, Jared F; Shaltout, Hossam A; Tegeler, Charles H

    2016-03-01

    Autonomic dysregulation and heterogeneous symptoms characterize postural orthostatic tachycardia syndrome (POTS). This study evaluated the effect of high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM(®)), a noninvasive, allostatic neurotechnology for relaxation and auto-calibration of neural oscillations, on heart rate variability, brain asymmetry, and autonomic symptoms, in adolescents with POTS. Seven subjects with POTS (three males, ages 15-18) underwent a median of 14 (10-16) HIRREM sessions over 13 (8-17) days. Autonomic function was assessed from 10-min continuous heart rate and blood pressure recordings, pre- and post-HIRREM. One-minute epochs of temporal high-frequency (23-36 Hz) brain electrical activity data (T3 and T4, eyes closed) were analyzed from baseline HIRREM assessment and subsequent sessions. Subjects rated autonomic symptoms before and after HIRREM. Four of seven were on fludrocortisone, which was stopped before or during their sessions. Heart rate variability in the time domain (standard deviation of the beat-to-beat interval) increased post-HIRREM (mean increase 51%, range 10-143, p = 0.03), as did baroreflex sensitivity (mean increase in high-frequency alpha 65%, range -6 to 180, p = 0.05). Baseline temporal electrical asymmetry negatively correlated with change in asymmetry from assessment to the final HIRREM session (p = 0.01). Summed high-frequency amplitudes at left and right temporal lobes decreased a median of 3.8 μV (p = 0.02). There was a trend for improvements in self-reported symptoms related to the autonomic nervous system. Use of HIRREM was associated with reduced sympathetic bias in autonomic cardiovascular regulation, greater symmetry and reduced amplitudes in temporal lobe high-frequency electrical activity, and a trend for reduced autonomic symptoms. Data suggest the potential for allostatic neurotechnology to facilitate increased flexibility in autonomic cardiovascular regulation, possibly

  13. Improving the effectiveness of real-time flood forecasting through Predictive Uncertainty estimation: the multi-temporal approach

    Science.gov (United States)

    Barbetta, Silvia; Coccia, Gabriele; Moramarco, Tommaso; Todini, Ezio

    2015-04-01

    The negative effects of severe flood events are usually contrasted through structural measures that, however, do not fully eliminate flood risk. Non-structural measures, such as real-time flood forecasting and warning, are also required. Accurate stage/discharge future predictions with appropriate forecast lead-time are sought by decision-makers for implementing strategies to mitigate the adverse effects of floods. Traditionally, flood forecasting has been approached by using rainfall-runoff and/or flood routing modelling. Indeed, both types of forecasts, cannot be considered perfectly representing future outcomes because of lacking of a complete knowledge of involved processes (Todini, 2004). Nonetheless, although aware that model forecasts are not perfectly representing future outcomes, decision makers are de facto implicitly assuming the forecast of water level/discharge/volume, etc. as "deterministic" and coinciding with what is going to occur. Recently the concept of Predictive Uncertainty (PU) was introduced in hydrology (Krzysztofowicz, 1999), and several uncertainty processors were developed (Todini, 2008). PU is defined as the probability of occurrence of the future realization of a predictand (water level/discharge/volume) conditional on: i) prior observations and knowledge, ii) the available information obtained on the future value, typically provided by one or more forecast models. Unfortunately, PU has been frequently interpreted as a measure of lack of accuracy rather than the appropriate tool allowing to take the most appropriate decisions, given a model or several models' forecasts. With the aim to shed light on the benefits for appropriately using PU, a multi-temporal approach based on the MCP approach (Todini, 2008; Coccia and Todini, 2011) is here applied to stage forecasts at sites along the Upper Tiber River. Specifically, the STAge Forecasting-Rating Curve Model Muskingum-based (STAFOM-RCM) (Barbetta et al., 2014) along with the Rating

  14. Temporal High-pass Filtering Nonuniformity Correction with Adaptive Time Constant%自适应时间常数的时域高通滤波校正算法

    Institute of Scientific and Technical Information of China (English)

    曹晓荷; 朱斌; 郭立新; 李晶; 常青; 龚涛

    2013-01-01

    The Temporal High-pass Filtering Nonuniformity Correction (THPF-NUC) algorithm has three major drawbacks, namely only correcting the offset coefficient, difficulty in choosing a proper time constant and unclear detail of corrected image. By analyzing the time constant’s effect on the correction quality, an improved THPF-NUC algorithm is proposed. Firstly, to guarantee the uniformity of the gain coefficient, the noise background image is subtracted from the output image of Infrared Focal Plane Arrays (IRFPA) as preprocessing. Then according to the motion degree obtained from the motion detection technique, adaptively adjust the time constant to design the low-pass filter. Lastly the high-boost filtering is adopted to improve the brightness of the whole IR image and enhance the details. The experiment on a real IR video shows that the proposed algorithm eliminates the ghosting artifact and the target fade-out effectively. And the corrected image is high quality with fast convergence rate, giving advantage to real-time engineering application.%针对时域高通滤波非均匀性校正算法中存在只对偏移响应系数进行校正、难以选取合适的时间常数以及滤波后图像细节不清晰等问题,本文通过分析时间常数对算法校正效果的影响,提出了一种改进的时域高通滤波非均匀性校正算法。首先采用离线采集的非均匀性噪声底图对红外焦平面阵列的原始输出图像进行预处理,去除部分固定模式噪声,保证了增益的均匀性;然后通过运动检测环节判断场景运动是否充分,根据运动程度自适应选取时间常数构造低通滤波器;最后运用高频提升滤波达到提升红外图像整体的亮度和增强目标细节的效果。对真实的红外视频图像实验表明,通过自适应选取时间常数有效地抑制了目标退化和伪像现象,且算法的收敛速度快,校正后图像细节清晰,有利于工程实时应用。

  15. Cross Layer Adaptation of Check Intervals in Low Power Listening MAC Protocols for Lifetime Improvement in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Maria-Cristina Marinescu

    2012-08-01

    Full Text Available Preamble sampling-based MAC protocols designed forWireless Sensor Networks (WSN are aimed at prolonging the lifetime of the nodes by scheduling their times of activity. This scheduling exploits node synchronization to find the right trade-off between energy consumption and delay. In this paper we consider the problem of node synchronization in preamble sampling protocols. We propose Cross Layer Adaptation of Check intervals (CLAC, a novel protocol intended to reduce the energy consumption of the nodes without significantly increasing the delay. Our protocol modifies the scheduling of the nodes based on estimating the delay experienced by a packet that travels along a multi-hop path. CLAC uses routing and MAC layer information to compute a delay that matches the packet arrival time. We have implemented CLAC on top of well-known routing and MAC protocols for WSN, and we have evaluated our implementation using the Avrora simulator. The simulation results confirm that CLAC improves the network lifetime at no additional packet loss and without affecting the end-to-end delay.

  16. Improving high carbon dioxide tolerance and carbon dioxide fixation capability of Chlorella sp. by adaptive laboratory evolution.

    Science.gov (United States)

    Li, Dengjin; Wang, Liang; Zhao, Quanyu; Wei, Wei; Sun, Yuhan

    2015-06-01

    CO2 capture by microalgae is a promising method to reduce greenhouse gas emissions. It is critical to construct a highly efficient way to obtain a microalgal strain tolerant to high CO2 concentrations with high CO2 fixation capability. In this study, two evolved Chlorella sp. strains, AE10 and AE20 were obtained after 31 cycles of adaptive laboratory evolution (ALE) under 10% and 20% CO2, respectively. Both of them grew rapidly in 30% CO2 and the maximal biomass concentration of AE10 was 3.68±0.08g/L, which was 1.22 and 2.94 times to those of AE20 and original strain, respectively. The chlorophyll contents of AE10 and AE20 were significantly higher than those of the original one under 1-30% CO2. The influences of ALE process on biochemical compositions of Chlorella cells were also investigated. This study proved that ALE was an effective approach to improve high CO2 tolerance of Chlorella sp.

  17. 3D positional control of magnetic levitation system using adaptive control: improvement of positioning control in horizontal plane

    Science.gov (United States)

    Nishino, Toshimasa; Fujitani, Yasuhiro; Kato, Norihiko; Tsuda, Naoaki; Nomura, Yoshihiko; Matsui, Hirokazu

    2012-01-01

    The objective of this paper is to establish a technique that levitates and conveys a hand, a kind of micro-robot, by applying magnetic forces: the hand is assumed to have a function of holding and detaching the objects. The equipment to be used in our experiments consists of four pole-pieces of electromagnets, and is expected to work as a 4DOF drive unit within some restricted range of 3D space: the three DOF are corresponding to 3D positional control and the remaining one DOF, rotational oscillation damping control. Having used the same equipment, Khamesee et al. had manipulated the impressed voltages on the four electric magnetics by a PID controller by the use of the feedback signal of the hand's 3D position, the controlled variable. However, in this system, there were some problems remaining: in the horizontal direction, when translating the hand out of restricted region, positional control performance was suddenly degraded. The authors propose a method to apply an adaptive control to the horizontal directional control. It is expected that the technique to be presented in this paper contributes not only to the improvement of the response characteristic but also to widening the applicable range in the horizontal directional control.

  18. Adaptive Iterative Dose Reduction Using Three Dimensional Processing (AIDR3D improves chest CT image quality and reduces radiation exposure.

    Directory of Open Access Journals (Sweden)

    Tsuneo Yamashiro

    Full Text Available To assess the advantages of Adaptive Iterative Dose Reduction using Three Dimensional Processing (AIDR3D for image quality improvement and dose reduction for chest computed tomography (CT.Institutional Review Boards approved this study and informed consent was obtained. Eighty-eight subjects underwent chest CT at five institutions using identical scanners and protocols. During a single visit, each subject was scanned using different tube currents: 240, 120, and 60 mA. Scan data were converted to images using AIDR3D and a conventional reconstruction mode (without AIDR3D. Using a 5-point scale from 1 (non-diagnostic to 5 (excellent, three blinded observers independently evaluated image quality for three lung zones, four patterns of lung disease (nodule/mass, emphysema, bronchiolitis, and diffuse lung disease, and three mediastinal measurements (small structure visibility, streak artifacts, and shoulder artifacts. Differences in these scores were assessed by Scheffe's test.At each tube current, scans using AIDR3D had higher scores than those without AIDR3D, which were significant for lung zones (p<0.0001 and all mediastinal measurements (p<0.01. For lung diseases, significant improvements with AIDR3D were frequently observed at 120 and 60 mA. Scans with AIDR3D at 120 mA had significantly higher scores than those without AIDR3D at 240 mA for lung zones and mediastinal streak artifacts (p<0.0001, and slightly higher or equal scores for all other measurements. Scans with AIDR3D at 60 mA were also judged superior or equivalent to those without AIDR3D at 120 mA.For chest CT, AIDR3D provides better image quality and can reduce radiation exposure by 50%.

  19. Flexibility of Scope, Type and Temporality in Mustang, Nepal. Opportunities for Adaptation in a Farming System Facing Climatic and Market Uncertainty

    Directory of Open Access Journals (Sweden)

    Nina Holmelin

    2013-03-01

    Full Text Available Climate change is projected to increase the seasonality in river flows in the great river systems of Himalaya and impose challenges to regional food production. Since climate change increases the uncertainty in local weather patterns, people’s ability to maintain local agricultural production will probably depend on how flexible the local farming systems are to adjust to unpredictable changes. The objective of this paper is to investigate the flexibility of one such farming system which is located in Mustang, Nepal, Himalaya. Defining flexibility as “uncommitted potentialities for change” following Gregory Bateson, the paper identifies opportunities for change in the farming system, as well as factors that constrain flexibility. Further developing the concept of flexibility, it is suggested that flexibility may be analyzed in terms of scope, type and temporal flexibility. Although there are several underexploited resources in the studied farming system, the present situation is not regarded as one of irrational and suboptimal exploitation of resources. Instead, unexploited resources imply opportunities for change, which provide the system with flexibility to rapidly adjust agricultural production to varying and uncertain conditions of production.

  20. Temporal Glare

    DEFF Research Database (Denmark)

    Ritschel, Tobias; Ihrke, Matthias; Frisvad, Jeppe Revall;

    2009-01-01

    Glare is a consequence of light scattered within the human eye when looking at bright light sources. This effect can be exploited for tone mapping since adding glare to the depiction of high-dynamic range (HDR) imagery on a low-dynamic range (LDR) medium can dramatically increase perceived contra...... to initially static HDR images. By conducting psychophysical studies, we validate that our method improves perceived brightness and that dynamic glare-renderings are often perceived as more attractive depending on the chosen scene.......Glare is a consequence of light scattered within the human eye when looking at bright light sources. This effect can be exploited for tone mapping since adding glare to the depiction of high-dynamic range (HDR) imagery on a low-dynamic range (LDR) medium can dramatically increase perceived contrast....... Even though most, if not all, subjects report perceiving glare as a bright pattern that fluctuates in time, up to now it has only been modeled as a static phenomenon. We argue that the temporal properties of glare are a strong means to increase perceived brightness and to produce realistic and...

  1. A Comparative Case Study Analysis of Administrators Perceptions on the Adaptation of Quality and Continuous Improvement Tools to Community Colleges in the State of Michigan

    Science.gov (United States)

    Mattis, Ted B.

    2011-01-01

    The purpose of this study was to determine whether community college administrators in the state of Michigan believe that commonly known quality and continuous improvement tools, prevalent in a manufacturing environment, can be adapted to a community college model. The tools, specifically Six Sigma, benchmarking and process mapping have played a…

  2. Temporal adaptations in generic and population-specific quality of life and falls efficacy in men with recent lower-limb amputations

    Directory of Open Access Journals (Sweden)

    Cleveland T. Barnett, PhD

    2013-05-01

    Full Text Available This study examined the longitudinal changes in generic health-related quality of life (QOL, prosthesis-related QOL, falls efficacy, and walking speed in men with lower-limb amputations up to 6 months following discharge from rehabilitation. Seven male unilateral transtibial amputees completed the Medical Outcomes Study 36-Item Short Form Health Survey, the Prosthesis Evaluation Questionnaire, and the Modified Falls Efficacy Scale at 1, 3, and 6 months postdischarge from rehabilitation. Walking speed was also recorded to objectively assess participants’ mobility. Health-related QOL measures displayed increases, resulting in large effect sizes though not reaching statistical significance. Prosthesis-related QOL measures indicated that scales relating to the participants’ prostheses improved and the support of significant others was the most positively scored variable. Walking speed increased by 0.12 m/s, although it was not significantly related to indices of QOL or falls efficacy. Falls efficacy did not improve significantly during the study period, although it was strongly related to QOL (p < 0.05. These results provide a novel insight into how QOL and falls efficacy develop in people with lower-limb amputations, alongside changes in mobility, after discharge from rehabilitation. Further improvements in physical health following discharge may be required to elicit subsequent increases in overall QOL and concurrent improvements in falls efficacy.

  3. 3D-IN LOOP FILTER FOR VIDEO COMPRESSION BASED ON MOTION COMPENSATED TEMPORAL PIXEL TRAJECTORIES

    OpenAIRE

    E. A. Ayele*, S. B. Dhok

    2016-01-01

    For H.264 standardization, the use of a deblocking filter was introduced in order to improve the quality of video compression through blocking artifacts reduction. Subsequently, the in-loop filters such as deblocking filter, sample adaptive offset, and adaptive loop filter are launched for the present HEVC standardization. However, both filters use spatial data from a frame of the video sequence only despite the fact of temporal correlation within frames. Hence, the quality of filtering proce...

  4. The importance of training strategy adaptation: a learner-oriented approach for improving older adults' memory and transfer.

    Science.gov (United States)

    Bottiroli, Sara; Cavallini, Elena; Dunlosky, John; Vecchi, Tomaso; Hertzog, Christopher

    2013-09-01

    We investigated the benefits of strategy-adaptation training for promoting transfer effects. This learner-oriented approach--which directly encourages the learner to generalize strategic behavior to new tasks--helps older adults appraise new tasks and adapt trained strategies to them. In Experiment 1, older adults in a strategy-adaptation training group used 2 strategies (imagery and sentence generation) while practicing 2 tasks (list and associative learning); they were then instructed on how to do a simple task analysis to help them adapt the trained strategies for 2 different unpracticed tasks (place learning and text learning) that were discussed during training. Two additional criterion tasks (name-face associative learning and grocery-list learning) were never mentioned during training. Two other groups were included: A strategy training group (who received strategy training and transfer instructions but not strategy-adaptation training) and a waiting-list control group. Both training procedures enhanced older adults' performance on the trained tasks and those tasks that were discussed during training, but transfer was greatest after strategy-adaptation training. Experiment 2 found that strategy-adaptation training conducted via a manual that older adults used at home also promoted transfer. These findings demonstrate the importance of adopting a learner-oriented approach to promote transfer of strategy training.

  5. A temporal-omic study of Propionibacterium freudenreichii CIRM-BIA1 adaptation strategies in conditions mimicking cheese ripening in the cold.

    Directory of Open Access Journals (Sweden)

    Marion Dalmasso

    Full Text Available Propionibacterium freudenreichii is used as a ripening culture in Swiss cheese manufacture. It grows when cheeses are ripened in a warm room (about 24°C. Cheeses with an acceptable eye formation level are transferred to a cold room (about 4°C, inducing a marked slowdown of propionic fermentation, but P. freudenreichii remains active in the cold. To investigate the P. freudenreichii strategies of adaptation and survival in the cold, we performed the first global gene expression profile for this species. The time-course transcriptomic response of P. freudenreichii CIRM-BIA1(T strain was analyzed at five times of incubation, during growth at 30°C then for 9 days at 4°C, under conditions preventing nutrient starvation. Gene expression was also confirmed by RT-qPCR for 28 genes. In addition, proteomic experiments were carried out and the main metabolites were quantified. Microarray analysis revealed that 565 genes (25% of the protein-coding sequences of P. freudenreichii genome were differentially expressed during transition from 30°C to 4°C (P1. At 4°C, a general slowing down was observed for genes implicated in the cell machinery. On the contrary, P. freudenreichii CIRM-BIA1(T strain over-expressed genes involved in lactate, alanine and serine conversion to pyruvate, in gluconeogenesis, and in glycogen synthesis. Interestingly, the expression of different genes involved in the formation of important cheese flavor compounds, remained unchanged at 4°C. This could explain the contribution of P. freudenreichii to cheese ripening even in the cold. In conclusion, P. freudenreichii remains metabolically active at 4°C and induces pathways to maintain its long-term survival.

  6. Graphene Oxides Decorated with Carnosine as an Adjuvant To Modulate Innate Immune and Improve Adaptive Immunity in Vivo.

    Science.gov (United States)

    Meng, Chunchun; Zhi, Xiao; Li, Chao; Li, Chuanfeng; Chen, Zongyan; Qiu, Xusheng; Ding, Chan; Ma, Lijun; Lu, Hongmin; Chen, Di; Liu, Guangqing; Cui, Daxiang

    2016-02-23

    Current studies have revealed the immune effects of graphene oxide (GO) and have utilized them as vaccine carriers and adjuvants. However, GO easily induces strong oxidative stress and inflammatory reaction at the site of injection. It is very necessary to develop an alternative adjuvant based on graphene oxide derivatives for improving immune responses and decreasing side effects. Carnosine (Car) is an outstanding and safe antioxidant. Herein, the feasibility and efficiency of ultrasmall graphene oxide decorated with carnosine as an alternative immune adjuvant were explored. OVA@GO-Car was prepared by simply mixing ovalbumin (OVA, a model antigen) with ultrasmall GO covalently modified with carnosine (GO-Car). We investigated the immunological properties of the GO-Car adjuvant in model mice. Results show that OVA@GO-Car can promote robust and durable OVA-specific antibody response, increase lymphocyte proliferation efficiency, and enhance CD4(+) T and CD8(+) T cell activation. The presence of Car in GO also probably contributes to enhancing the antigen-specific adaptive immune response through modulating the expression of some cytokines, including IL-6, CXCL1, CCL2, and CSF3. In addition, the safety of GO-Car as an adjuvant was evaluated comprehensively. No symptoms such as allergic response, inflammatory redness swelling, raised surface temperatures, physiological anomalies of blood, and remarkable weight changes were observed. Besides, after modification with carnosine, histological damages caused by GO-Car in lung, muscle, kidney, and spleen became weaken significantly. This study sufficiently suggest that GO-Car as a safe adjuvant can effectively enhance humoral and innate immune responses against antigens in vivo. PMID:26766427

  7. Graphene Oxides Decorated with Carnosine as an Adjuvant To Modulate Innate Immune and Improve Adaptive Immunity in Vivo.

    Science.gov (United States)

    Meng, Chunchun; Zhi, Xiao; Li, Chao; Li, Chuanfeng; Chen, Zongyan; Qiu, Xusheng; Ding, Chan; Ma, Lijun; Lu, Hongmin; Chen, Di; Liu, Guangqing; Cui, Daxiang

    2016-02-23

    Current studies have revealed the immune effects of graphene oxide (GO) and have utilized them as vaccine carriers and adjuvants. However, GO easily induces strong oxidative stress and inflammatory reaction at the site of injection. It is very necessary to develop an alternative adjuvant based on graphene oxide derivatives for improving immune responses and decreasing side effects. Carnosine (Car) is an outstanding and safe antioxidant. Herein, the feasibility and efficiency of ultrasmall graphene oxide decorated with carnosine as an alternative immune adjuvant were explored. OVA@GO-Car was prepared by simply mixing ovalbumin (OVA, a model antigen) with ultrasmall GO covalently modified with carnosine (GO-Car). We investigated the immunological properties of the GO-Car adjuvant in model mice. Results show that OVA@GO-Car can promote robust and durable OVA-specific antibody response, increase lymphocyte proliferation efficiency, and enhance CD4(+) T and CD8(+) T cell activation. The presence of Car in GO also probably contributes to enhancing the antigen-specific adaptive immune response through modulating the expression of some cytokines, including IL-6, CXCL1, CCL2, and CSF3. In addition, the safety of GO-Car as an adjuvant was evaluated comprehensively. No symptoms such as allergic response, inflammatory redness swelling, raised surface temperatures, physiological anomalies of blood, and remarkable weight changes were observed. Besides, after modification with carnosine, histological damages caused by GO-Car in lung, muscle, kidney, and spleen became weaken significantly. This study sufficiently suggest that GO-Car as a safe adjuvant can effectively enhance humoral and innate immune responses against antigens in vivo.

  8. Project Temporalities

    DEFF Research Database (Denmark)

    Tryggestad, Kjell; Justesen, Lise; Mouritsen, Jan

    2013-01-01

    into account. This may require investments in new project management technologies. Originality/value – This paper adds to the literatures on project temporalities and stakeholder theory by connecting them to the question of non-human stakeholders and to project management technologies.......Purpose – The purpose of this paper is to explore how animals can become stakeholders in interaction with project management technologies and what happens with project temporalities when new and surprising stakeholders become part of a project and a recognized matter of concern to be taken...... into account. Design/methodology/approach – The paper is based on a qualitative case study of a project in the building industry. The authors use actor-network theory (ANT) to analyze the emergence of animal stakeholders, stakes and temporalities. Findings – The study shows how project temporalities can...

  9. An ECT System Based on Improved RBF Network and Adaptive Wavelet Image Enhancement for Solid/Gas Two-phase Flow

    Institute of Scientific and Technical Information of China (English)

    陈夏; 胡红利; 张娟; 周屈兰

    2012-01-01

    Electrical capacitance tomography(ECT) is a non-invasive imaging technique that aims at visualizing the cross-sectional permittivity distribution and phase distribution of solid/gas two-phase flow based on the measured capacitance.To solve the nonlinear and ill-posed inverse problem:image reconstruction of ECT system,this paper proposed a new image reconstruction method based on improved radial basis function(RBF) neural network combined with adaptive wavelet image enhancement.Firstly,an improved RBF network was applied to establish the mapping model between the reconstruction image pixels and the capacitance values measured.Then,for better image quality,adaptive wavelet image enhancement technique was emphatically analyzed and studied,which belongs to a space-frequency analysis method and is suitable for image feature-enhanced.Through multi-level wavelet decomposition,edge points of the image produced from RBF network can be determined based on the neighborhood property of each sub-band;noise distribution in the space-frequency domain can be estimated based on statistical characteristics;after that a self-adaptive edge enhancement gain can be constructed.Finally,the image is reconstructed with adjusting wavelet coefficients.In this paper,a 12-electrode ECT system and a pneumatic conveying platform were built up to verify this image reconstruction algorithm.Experimental results demonstrated that adaptive wavelet image enhancement technique effectively implemented edge detection and image enhancement,and the improved RBF network and adaptive wavelet image enhancement hybrid algorithm greatly improved the quality of reconstructed image of solid/gas two-phase flow [pulverized coal(PC)/air].

  10. Adaptively Spatio-temporal Weighted Method for Removing Cloud Obscuration from MODIS Daily Snow Cover Products%时空自适应加权的MODIS积雪产品去云方法

    Institute of Scientific and Technical Information of China (English)

    付文轩; 沈焕锋; 李星华; 黄春林; 侯金亮

    2016-01-01

    Due to the cloud obscuration,MODIS snow cover products are subjected to spatially discontinuous issues,which decrease the application potential.Therefore,this work proposed an adaptively spatio-temporal weighted method for alleviating the trouble.This method simultaneously took the spatial and temporal correlations of snow cover into consideration,and weighted their contributions to snow distribution automatically.Based on simulated experiments and daily snow depth data at climate stations,we evaluated its accuracy in Ili river basin of Xinjiang.The results indicated that our proposed method can remove cloud obscuration completely,with overall accuracy above 90% under different cloud coverages.Since the cloud-free snow cover maps reflect the real distribution of snow cover,they can be widely used for monitoring snow.%鉴于MODIS积雪产品存在的空间不连续降低了数据的应用潜力,该文提出一种时空自适应加权的去云方法,同时顾及积雪在空间和时间上的相关性,自适应地衡量两者对积雪分布的影响.以新疆伊犁河流域为实验区,进行了模拟验证和基于气象台站数据的真实验证.结果表明:该方法能完全去除云覆盖,去云精度可达到90%以上,且对不同云量的修复都有较好的鲁棒性,能真实地反映地面积雪覆盖情况,可为积雪监测研究提供数据保障.

  11. Improving education due to the need to adapt it to the requirements of the economic development and of the labor market - issues of past history and contemporary features

    Directory of Open Access Journals (Sweden)

    Cornelia Nistor

    2015-12-01

    Full Text Available Improving education has been and continues to be a necessary condition in any society. Education contributes to increase the level of civilization, to develop the individual personality, but also to increase the level of the economic development. Organization and subsequent reorganization of the Romanian education system has been pursuing desiring to adapt better it better to the labor market needs and to adapt it to the international education system. The management strategies which are applied in this area should be considered adapting it to the domestic and international labor market conditions to the new education methods and techniques, used at the international level. The new trends desiring to transform the economy into a green economy require increased investments in education, in order to train the specialists in new green areas.

  12. A retroactive spatial cue improved VSTM capacity in mild cognitive impairment and medial temporal lobe amnesia but not in healthy older adults.

    Science.gov (United States)

    Newsome, Rachel N; Duarte, Audrey; Pun, Carson; Smith, Victoria M; Ferber, Susanne; Barense, Morgan D

    2015-10-01

    Visual short-term memory (VSTM) is a vital cognitive ability, connecting visual input with conscious awareness. VSTM performance declines with mild cognitive impairment (MCI) and medial temporal lobe (MTL) amnesia. Many studies have shown that providing a spatial retrospective cue ("retrocue") improves VSTM capacity estimates for healthy young adults. However, one study has demonstrated that older adults are unable to use a retrocue to inhibit irrelevant items from memory. It is unknown whether patients with MCI and MTL amnesia will be able to use a retrocue to benefit their memory. We administered a retrocue and a baseline (simultaneous cue, "simucue") task to young adults, older adults, MCI patients, and MTL cases. Consistent with previous findings, young adults showed a retrocue benefit, whereas healthy older adults did not. In contrast, both MCI patients and MTL cases showed a retrocue benefit--the use of a retrocue brought patient performance up to the level of age-matched controls. We speculate that the patients were able to use the spatial information from the retrocue to reduce interference and facilitate binding items to their locations. PMID:26300388

  13. Adapt-N: A Cloud-Based Computational Tool for Crop Nitrogen Management that Improves Production and Environmental Outcomes

    Science.gov (United States)

    van Es, Harold; Sela, Shai; Marjerison, Rebecca; Melkonian, Jeff

    2016-04-01

    Maize production accounts for the largest share of crop land area in the US and is the largest consumer of nitrogen (N) fertilizers, while also having low N use efficiency. Routine application of N fertilizer has led to well-documented environmental problems and social costs. Adapt-N is a computational tool that combines soil, crop and management information with near-real-time weather data to estimate optimum N application rates for maize. Its cloud-based implementation allows for tracking and timely management of the dynamic gains and losses of N in cropping systems. This presentation will provide an overview of the tool and its implementation of farms. We also evaluated Adapt-N tool during five growing seasons (2011-to-2015) using a large dataset of both side-by-side (SBS) strip trials and multi-N rate experiments. The SBS trials consisted of 115 on-farm strip trials in Iowa and New York, each trial including yield results from replicated field-scale plots involving two sidedress N rate treatments: Adapt-N-estimated and Grower-selected (conventional). The Adapt-N rates were on average 53 and 30 kg ha-1 lower than Grower rates for NY and IA, respectively (-34% overall), with no statistically significant difference in yields. On average, Adapt-N rates increased grower profits by 63.9 ha-1 and resulted in an Adapt-N estimated decrease of 28 kg ha-1 (38%) in environmental N losses. A second set of strip trials involved multiple N-rate experiments in Wisconsin, Indiana, Ohio and NY, which allowed for the comparison of Adapt-N and conventional static recommendations to an Economic Optimum N Rate (determined through response model fitting). These trials demonstrated that Adapt-N can achieve the same profitability with greatly reduced average N inputs of 20 lbs N/ac for the Midwest and 65 lbs N/ac for the Northeast, resulting in significantly lower environmental losses. In conclusion, Adapt-N recommendations resulted in both increased growers profits and decreased

  14. Temporal variations of the fractal properties of seismicity in the western part of the north Anatolian fault zone: possible artifacts due to improvements in station coverage

    Directory of Open Access Journals (Sweden)

    A. O. Öncel

    1995-01-01

    Full Text Available Seismically-active fault zones are complex natural systems exhibiting scale-invariant or fractal correlation between earthquakes in space and time, and a power-law scaling of fault length or earthquake source dimension consistent with the exponent b of the Gutenberg-Richter frequency-magnitude relation. The fractal dimension of seismicity is a measure of the degree of both the heterogeneity of the process (whether fixed or self-generated and the clustering of seismic activity. Temporal variations of the b-value and the two-point fractal (correlation dimension Dc have been related to the preparation process for natural earthquakes and rock fracture in the laboratory These statistical scaling properties of seismicity may therefore have the potential at least to be sensitive short- term predictors of major earthquakes. The North Anatolian Fault Zone (NAFZ is a seismicallyactive dextral strike slip fault zone which forms the northern boundary of the westward moving Anatolian plate. It is splayed into three branches at about 31oE and continues westward toward the northern Aegean sea. In this study, we investigate the temporal variation of Dc and the Gutenberg-Richter b-value for seismicity in the western part of the NAFZ (including the northern Aegean sea for earthquakes of Ms > 4.5 occurring in the period between 1900 and 1992. b ranges from 0.6-1.6 and Dc from 0.6 to 1.4. The b-value is found to be weakly negatively correlated with Dc (r=-0.56. However the (log of event rate N is positively correlated with b, with a similar degree of statistical significance (r=0.42, and negatively correlated with Dc (r=-0.48. Since N increases dramatically with improved station coverage since 1970, the observed negative correlation between b and Dc is therefore more likely to be due to this effect than any underlying physical process in this case. We present this as an example of how man-made artefacts of recording can have similar statistical effects to

  15. [Improvement of oral health at institutionalized patients. Choice and validation of an adapted oral hygiene kit in long-term care unit].

    Science.gov (United States)

    Lacoste-Ferré, Marie-Hélène; Gendre, Charlotte; Rapp, Lucie; Gautrault, Sabrina; Hermabessière, Sophie; Rolland, Yves

    2014-09-01

    The initiatives to improve the quality are widely developed in the healthcare sector. So, an evaluation of the professional practices (EPP) concerning oral diseases in elderly was organized in the long term care unit of the teaching hospital of Toulouse. In the dynamic of this EPP, a pilot study consisted in estimating a new kit of oral hygiene. This hygiene kit was chosen according to defined criteria adapted to the elderly. The results show a clear improvement of the oral health measured with a specific index (Oral health assessment tool).

  16. Improved Biodegradation of 1,2,4-Trichlorobenzene by Adapted Microorganisms in Agricultural Soil and in Soil Suspension Cultures

    Institute of Scientific and Technical Information of China (English)

    SONG Yang; WANG Fang; F. O. KENGARA; BIAN Yong-Rong; YANG Xing-Lun; LIU Cui-Ying; JIANG Xin

    2011-01-01

    Inoculating soil with an adapted microbial community is a more effective bioaugrnentation approach than inoculation with pure strains in bioremediation.However,information on the potential of different inocula from sites with varying contamination levels and pollution histories in soil remediation is lacking.The objective of the study was to investigate the potential of adapted microorganisms in soil inocula,with different contamination levels and pollution histories,to degrade 1,2,4-trichlorobenzene (1,2,4-TCB).Three different soils from chlorobenzene-contaminated sites were inoculated into agricultural soils and soil suspension cultures spiked with 1,2,4-TCB.The results showed that 36.52% of the initially applied 1,2,4-TCB was present in the non-inoculated soil,whereas about 19.00% of 1,2,4-TCB was present in the agricultural soils inoculated with contaminated soils after 28 days of incubation.The soils inoculated with adapted microbial biomass (in the soil inocula) showed higher respiration and lower 1,2,4-TCB volatilization than the non-inoculated soils,suggesting the existence of 1,2,4-TCB adapted degraders in the contaminated soils used for inoculation.It was further confirmed in the contaminated soil suspension cultures that the concentration of inorganic chloride ions increased continuously over the entire experimental period.Higher contamination of the inocula led not only to higher degradation potential but also to higher residue formation.However,even inocula of low-level contamination were effective in enhancing the degradation of 1,2,4-TCB.Therefore,applying adapted microorganisms in the form of soil inocula,especially with lower contamination levels,could be an effective and environment-friendly strategy for soil remediation.

  17. Adapting developing country epidemiological assessment techniques to improve the quality of health needs assessments in developed countries

    Directory of Open Access Journals (Sweden)

    Handy Deirdre

    2005-04-01

    Full Text Available Abstract Background We were commissioned to carry out three health assessments in urban areas of Dublin in Ireland. We required an epidemiologically robust method that could collect data rapidly and inexpensively. We were dealing with inadequate health information systems, weak planning data and a history of inadequate recipient involvement in health service planning. These problems had also been identified by researchers carrying out health assessments in developing countries. This paper reports our experience of adapting a cluster survey model originally developed by international organisations to assess community health needs and service coverage in developing countries and applying our adapted model to three urban areas in Dublin, Ireland Methods We adapted the model to control for socio-economic heterogeneity, to take account of the inadequate population list, to ensure a representative sample and to account for a higher prevalence of degenerative and chronic diseases. We employed formal as well as informal communication methods and adjusted data collection times to maximise participation. Results The model we adapted had the capacity to ascertain both health needs and health care delivery needs. The community participated throughout the process and members were trained and employed as data collectors. The assessments have been used by local health boards and non-governmental agencies to plan and deliver better or additional services. Conclusion We were able to carry out high quality health needs assessments in urban areas by adapting and applying a developing country health assessment method. Issues arose relating to health needs assessment as part of the planning cycle and the role of participants in the process.

  18. How urban system vulnerabilities to flooding could be assessed to improve resilience and adaptation in spatial planning

    Science.gov (United States)

    Pasi, Riccardo; Viavattene, Christophe; La Loggia, Goffredo

    2016-04-01

    Natural hazards damage assets and infrastructure inducing disruptions to urban functions and key daily services. These disruptions may be short or long with a variable spatial scale of impact. From an urban planning perspective, measuring these disruptions and their consequences at an urban scale is fundamental in order to develop more resilient cities. Whereas the assessment of physical vulnerabilities and direct damages is commonly addressed, new methodologies for assessing the systemic vulnerability at the urban scale are required to reveal these disruptions and their consequences. Physical and systemic vulnerability should be measured in order to reflect the multifaceted fragility of cities in the face of external stress, both in terms of the natural/built environment and socio-economic sphere. Additionally, a systemic approach allows the consideration of vulnerability across different spatial scales, as impacts may vary and be transmitted across local, regional or national levels. Urban systems are spatially distributed and the nature of this can have significant effects on flood impacts. The proposed approach identifies the vulnerabilities of flooding within urban contexts, including both in terms of single elementary units (buildings, infrastructures, people, etc.) and systemic functioning (urban functions and daily life networks). Direct losses are appraised initially using conventional methodologies (e.g. depth-damage functions). This aims to both understand the spatial distribution of physical vulnerability and associated losses and, secondly, to identify the most vulnerable building types and ways to improve the physical adaptation of our cities, proposing changes to building codes, design principles and other municipal regulation tools. The subsequent systemic approach recognises the city as a collection of sub-systems or functional units (such as neighbourhoods and suburbs) providing key daily services for inhabitants (e.g. healthcare facilities

  19. Cross-axis adaptation improves 3D vestibulo-ocular reflex alignment during chronic stimulation via a head-mounted multichannel vestibular prosthesis.

    Science.gov (United States)

    Dai, Chenkai; Fridman, Gene Y; Chiang, Bryce; Davidovics, Natan S; Melvin, Thuy-Anh; Cullen, Kathleen E; Della Santina, Charles C

    2011-05-01

    By sensing three-dimensional (3D) head rotation and electrically stimulating the three ampullary branches of a vestibular nerve to encode head angular velocity, a multichannel vestibular prosthesis (MVP) can restore vestibular sensation to individuals disabled by loss of vestibular hair cell function. However, current spread to afferent fibers innervating non-targeted canals and otolith end organs can distort the vestibular nerve activation pattern, causing misalignment between the perceived and actual axis of head rotation. We hypothesized that over time, central neural mechanisms can adapt to correct this misalignment. To test this, we rendered five chinchillas vestibular deficient via bilateral gentamicin treatment and unilaterally implanted them with a head-mounted MVP. Comparison of 3D angular vestibulo-ocular reflex (aVOR) responses during 2 Hz, 50°/s peak horizontal sinusoidal head rotations in darkness on the first, third, and seventh days of continual MVP use revealed that eye responses about the intended axis remained stable (at about 70% of the normal gain) while misalignment improved significantly by the end of 1 week of prosthetic stimulation. A comparable time course of improvement was also observed for head rotations about the other two semicircular canal axes and at every stimulus frequency examined (0.2-5 Hz). In addition, the extent of disconjugacy between the two eyes progressively improved during the same time window. These results indicate that the central nervous system rapidly adapts to multichannel prosthetic vestibular stimulation to markedly improve 3D aVOR alignment within the first week after activation. Similar adaptive improvements are likely to occur in other species, including humans.

  20. 提高大学新生适应教育实效性的思考%Thinking of Improvement of Effectiveness of Adaption Education to Freshman

    Institute of Scientific and Technical Information of China (English)

    朱薇薇

    2012-01-01

    大学新生适应教育是大学生入学教育的重要内容,是大学生能够顺利适应新环境的重要环节。加强调研、创新形式、引入团队辅导、发挥朋辈引导的作用、将新生适应教育纳入课程体系、与人才培养计划相结合以及建立反馈和评价机制,是提高新生适应教育实效性的有效措施。%education for freshmen is an important content in enrollment education and a vital link for them to adapt the new environment. It' s necessary to strengthen research and innovate, to introduce team tutoring, get schoolmates to play a guiding role and reintegrate adaption education into the curriculum system, and to combine adaption education with talent training and establish feedback mechanism and evaluation mechanism, which is to an effective measure to improve the efficiency of the adaption education to freshmen.

  1. Forward Masking: Temporal Integration or Adaptation?

    DEFF Research Database (Denmark)

    Ewert, Stephan D.; Hau, Ole; Dau, Torsten

    2007-01-01

    Hearing – From Sensory Processing to Perception presents the papers of the latest "International Symposium on Hearing," a meeting held every three years focusing on psychoacoustics and the research of the physiological mechanisms underlying auditory perception. The proceedings provide an up-to-date...

  2. Adapting ski area operations to a warmer climate in the Swiss Alps through snowmaking investments and efficiency improvements

    OpenAIRE

    Gonseth, Camille

    2008-01-01

    Economic consequences of climate change for the Swiss winter tourism have been assessed in two studies. Though estimates of the potential annual costs highly differ between them, they however agree on two points. On the one hand, winter tourism will be one of the most affected economic sectors. On the other hand, impacts of climate change on this sector will be very disruptive. In this context, adaptation strategies must play an important role in the Swiss winter tourism sector in order to al...

  3. Adapting ski area operations to a warmer climate in the Swiss Alps through snowmaking investments and efficiency improvements

    OpenAIRE

    Gonseth, Camille; Thalmann, Philippe

    2009-01-01

    Economic consequences of climate change for the Swiss winter tourism have been assessed in two studies. Though estimates of the potential annual costs highly differ between them, they however agree on two points. On the one hand, winter tourism will be one of the most affected economic sectors. On the other hand, impacts of climate change on this sector will be very disruptive. In this context, adaptation strategies must play an important role in the Swiss winter tourism sector in order to al...

  4. Adaptive foreground and shadow segmentation using hidden conditional random fields

    Institute of Scientific and Technical Information of China (English)

    CHU Yi-ping; YE Xiu-zi; QIAN Jiang; ZHANG Yin; ZHANG San-yuan

    2007-01-01

    Video object segmentation is important for video surveillance, object tracking, video object recognition and video editing. An adaptive video segmentation algorithm based on hidden conditional random fields (HCRFs) is proposed, which models spatio-temporal constraints of video sequence. In order to improve the segmentation quality, the weights of spatio-temporal constraints are adaptively updated by on-line learning for HCRFs. Shadows are the factors affecting segmentation quality. To separate foreground objects from the shadows they cast, linear transform for Gaussian distribution of the background is adopted to model the shadow. The experimental results demonstrated that the error ratio of our algorithm is reduced by 23% and 19% respectively,compared with the Gaussian mixture model (GMM) and spatio-temporal Markov random fields (MRFs).

  5. A single blinded randomised controlled pilot trial of prism adaptation for improving self-care in stroke patients with neglect.

    Science.gov (United States)

    Turton, Ailie J; O'Leary, Kelly; Gabb, Judith; Woodward, Rebecca; Gilchrist, Iain D

    2010-04-01

    Prism adaptation has been shown to alleviate the symptoms of unilateral spatial neglect following stroke in single case and small group studies. The purposes of this single blinded pilot randomised controlled trial were to determine the feasibility of delivering prism adaptation treatment in a clinically valid sample and to assess its impact on self-care. Thirty seven right hemisphere stroke patients with unilateral spatial neglect were randomised into either prism adaptation (using 10 dioptre, 6 degree prisms) or sham treatment (using plain glasses) groups. Treatment was delivered each weekday for two weeks. Pointing accuracy, without vision of the finger, was recorded each day before treatment. Outcome was measured, by blinded assessors, four days and eight weeks after the end of treatment using the Catherine Bergego Scale (CBS) and the conventional neuropsychological tests from the Behavioural Inattention Test (BIT). Thirty four patients received treatment: 16 with prisms, 18 sham. Mean compliance was 99% and 97%, respectively. Over the treatment days only the prism treated group showed increased leftward bias in open loop pointing to targets on a touch screen. However, despite the group level changes in pointing behaviour no overall effect of the treatment on self-care or BIT were found.

  6. Adaptive management

    Science.gov (United States)

    Allen, Craig R.; Garmestani, Ahjond S.

    2015-01-01

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive management has explicit structure, including a careful elucidation of goals, identification of alternative management objectives and hypotheses of causation, and procedures for the collection of data followed by evaluation and reiteration. The process is iterative, and serves to reduce uncertainty, build knowledge and improve management over time in a goal-oriented and structured process.

  7. 改进的抗自适应泄漏公钥加密方案%Improved Adaptive Leakage-resilient Public Key Encryption Scheme

    Institute of Scientific and Technical Information of China (English)

    陈浩; 朱艳琴; 罗喜召

    2012-01-01

    Halevi's adaptive leakage-resilient Public Key Encryption(PKE) scheme can only resist Chosen-Plaintext-Attack(CPA) but can not resist Chosen-Cipertext-Attack(CCA). This paper uses double encryption and non-interactive zero knowledge proof systems to improve the scheme, and proposes a formal definition on adaptive leakage-resilient against CCA. Based on the definition, an adaptive-resilient PKE against CCA is constructed. Security analysis shows that improved scheme has the same secret key size, and it is more secure.%Halevi提出的抗自适应泄漏公钥加密(PKE)方案(TCC 2011会议论文集)只能抵抗选择明文攻击,不能抵抗选择密文攻击(CCA).为此,利用双加密技术和非交互的零知识证明系统对其进行改进,基于CCA安全的抗自适应泄漏的形式化定义,给出一个新的PKE方案.理论分析结果表明,与原方案相比,新方案具有相同的密钥长度和抗泄漏量,并且安全性更高.

  8. 改进的自适应汉维句子对齐%Improved adaptive algorithm for Chinese-Uyghur sentence alignment

    Institute of Scientific and Technical Information of China (English)

    田生伟; 禹龙; 杨飞宇

    2011-01-01

    This paper proposes an improved adaptive algorithm for Chinese-Uyghur sentence alignment.Traditional alignment methods can not well adapt to change in types of corpus,the algorithm makes ues of current Chinese-Uyghur text length ratio of bytes and historical matching model, modifies the alignment model parameters dynamically to meet the changes in types of corpus and improves sentence alignment algorithm performance.Compared with alignment algorithm based on length, alignment improves alignment accuarcy 3.5 percentage and recall 2.7 percentage, compared with mixed-aligned model .alignment improves 1.9 percentage and 1.8 percentage.Experimental results show that the algorithm can adapt to change in types of corpus well.%提出了改进的自适应汉维句子对齐算法对齐汉维语句子.针对传统对齐方法不能较好地适应语料类型的变化,算法利用当前待对齐汉维文本的字节长度比和历史匹配模式数据,动态修正对齐模型的参数,使其适应语料类型的变化,提高了汉维句子对齐算法的性能,对齐的正确率和召回率较长度对齐模型分别提高了3.5个百分点和2.7个百分点,较混合对齐提高了1.9个百分点和1.8个百分点.实验结果验证了该算法能够有效地适应语料类型的变化.

  9. Short-term adaptation improves the fermentation performance of Saccharomyces cerevisiae in the presence of acetic acid at low pH.

    Science.gov (United States)

    Sànchez i Nogué, Violeta; Narayanan, Venkatachalam; Gorwa-Grauslund, Marie F

    2013-08-01

    The release of acetic acid due to deacetylation of the hemicellulose fraction during the treatment of lignocellulosic biomass contributes to the inhibitory character of the generated hydrolysates. In the present study, we identified a strain-independent adaptation protocol consisting of pre-cultivating the strain at pH 5.0 in the presence of at least 4 g L⁻¹ acetic acid that enabled aerobic growth and improved fermentation performance of Saccharomyces cerevisiae cells at low pH (3.7) and in the presence of inhibitory levels of acetic acid (6 g L⁻¹). During anaerobic cultivation with adapted cells of strain TMB3500, the specific ethanol production rate was increased, reducing the fermentation time to 48 %. PMID:23872959

  10. Identifying Optimal Temporal Scale for the Correlation of AOD and Ground Measurements of PM2.5 to Improve the Model Performance in a Real-time Air Quality Estimation System

    Science.gov (United States)

    Li, Hui; Faruque, Fazlay; Williams, Worth; Al-Hamdan, Mohammad; Luvall, Jeffrey C.; Crosson, William; Rickman, Douglas; Limaye, Ashutosh

    2009-01-01

    Aerosol optical depth (AOD), an indirect estimate of particle matter using satellite observations, has shown great promise in improving estimates of PM 2.5 air quality surface. Currently, few studies have been conducted to explore the optimal way to apply AOD data to improve the model accuracy of PM 2.5 surface estimation in a real-time air quality system. We believe that two major aspects may be worthy of consideration in that area: 1) the approach to integrate satellite measurements with ground measurements in the pollution estimation, and 2) identification of an optimal temporal scale to calculate the correlation of AOD and ground measurements. This paper is focused on the second aspect on the identifying the optimal temporal scale to correlate AOD with PM2.5. Five following different temporal scales were chosen to evaluate their impact on the model performance: 1) within the last 3 days, 2) within the last 10 days, 3) within the last 30 days, 4) within the last 90 days, and 5) the time period with the highest correlation in a year. The model performance is evaluated for its accuracy, bias, and errors based on the following selected statistics: the Mean Bias, the Normalized Mean Bias, the Root Mean Square Error, Normalized Mean Error, and the Index of Agreement. This research shows that the model with the temporal scale of within the last 30 days displays the best model performance in this study area using 2004 and 2005 data sets.

  11. Temporal naturalism

    Science.gov (United States)

    Smolin, Lee

    2015-11-01

    Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

  12. IMPROVEMENT OF ACCURACY OF RADIATIVE HEAT TRANSFER DIFFERENTIAL APPROXIMATION METHOD FOR MULTI DIMENSIONAL SYSTEMS BY MEANS OF AUTO-ADAPTABLE BOUNDARY CONDITIONS

    Directory of Open Access Journals (Sweden)

    K. V. Dobrego

    2015-01-01

    Full Text Available Differential approximation is derived from radiation transfer equation by averaging over the solid angle. It is one of the more effective methods for engineering calculations of radia- tive heat transfer in complex three-dimensional thermal power systems with selective and scattering media. The new method for improvement of accuracy of the differential approximation based on using of auto-adaptable boundary conditions is introduced in the paper. The  efficiency  of  the  named  method  is  proved  for  the  test  2D-systems.  Self-consistent auto-adaptable boundary conditions taking into consideration the nonorthogonal component of the incident to the boundary radiation flux are formulated. It is demonstrated that taking in- to consideration of the non- orthogonal incident flux in multi-dimensional systems, such as furnaces, boilers, combustion chambers improves the accuracy of the radiant flux simulations and to more extend in the zones adjacent to the edges of the chamber.Test simulations utilizing the differential approximation method with traditional boundary conditions, new self-consistent boundary conditions and “precise” discrete ordinates method were performed. The mean square errors of the resulting radiative fluxes calculated along the boundary of rectangular and triangular test areas were decreased 1.5–2 times by using auto- adaptable boundary conditions. Radiation flux gaps in the corner points of non-symmetric sys- tems are revealed by using auto-adaptable boundary conditions which can not be obtained by using the conventional boundary conditions.

  13. Improving the performance of computer-aided detection of subtle breast masses using an adaptive cueing method

    International Nuclear Information System (INIS)

    Current computer-aided detection (CAD) schemes for detecting mammographic masses have several limitations including high correlation with radiologists’ detection and cueing most subtle masses only on one view. To increase CAD sensitivity in cueing more subtle masses that are likely missed and/or overlooked by radiologists without increasing false-positive rates, we investigated a new case-dependent cueing method by combining the original CAD-generated detection scores with a computed bilateral mammographic density asymmetry index. Using the new method, we adaptively raise the CAD-generated scores of the regions detected on ‘high-risk’ cases to cue more subtle mass regions and reduce the CAD scores of the regions detected on ‘low-risk’ cases to discard more false-positive regions. A testing dataset involving 78 positive and 338 negative cases was used to test this adaptive cueing method. Each positive case involves two sequential examinations in which the mass was detected in ‘current’ examination and missed in ‘prior’ examination but detected in a retrospective review by radiologists. Applying to this dataset, a pre-optimized CAD scheme yielded 75% case-based and 55% region-based sensitivity on ‘current’ examinations at a false-positive rate of 0.25 per image. CAD sensitivity was reduced to 42% (case based) and 27% (region based) on ‘prior’ examinations. Using the new cueing method, case-based and region-based sensitivity could maximally increase 9% and 33% on the ‘prior’ examinations, respectively. The percentages of the masses cued on two views also increased from 27% to 65%. The study demonstrated that using this adaptive cueing method enabled us to help CAD cue more subtle cancers without increasing the false-positive cueing rate. (paper)

  14. Improving depiction of temporal bone anatomy with low-radiation dose CT by an integrated circuit detector in pediatric patients: a preliminary study.

    Science.gov (United States)

    He, Jingzhen; Zu, Yuliang; Wang, Qing; Ma, Xiangxing

    2014-12-01

    The purpose of this study was to determine the performance of low-dose computed tomography (CT) scanning with integrated circuit (IC) detector in defining fine structures of temporal bone in children by comparing with the conventional detector. The study was performed with the approval of our institutional review board and the patients' anonymity was maintained. A total of 86 children0.05). The low-dose CT images acquired with the IC detector provide better depiction of fine osseous structures of temporal bone than that with the conventional DC detector.

  15. Improving pattern discovery and visualization of SAGE data through poisson-based self-adaptive neural networks.

    Science.gov (United States)

    Zheng, Huiru; Wang, Haiying; Azuaje, Francisco

    2008-07-01

    Serial analysis of gene expression (SAGE) allows a detailed, simultaneous analysis of thousands of genes without the need for prior, complete gene sequence information. However, due to its inherent complexity and the lack of complete structural and function knowledge, mining vast collections of SAGE data to extract useful knowledge poses great challenges to traditional analytical techniques. Moreover, SAGE data are characterized by a specific statistical model that has not been incorporated into traditional data analysis techniques. The analysis of SAGE data requires advanced, intelligent computational techniques, which consider the underlying biology and the statistical nature of SAGE data. By addressing the statistical properties demonstrated by SAGE data, this paper presents a new self-adaptive neural network, Poisson-based growing self-organizing map (PGSOM), which implements novel weight adaptation and neuron growing strategies. An empirical study of key dynamic mechanisms of PGSOM is presented. It was tested on three datasets, including synthetic and experimental SAGE data. The results indicate that, in comparison to traditional techniques, the PGSOM offers significant advantages in the context of pattern discovery and visualization in SAGE data. The pattern discovery and visualization platform discussed in this paper can be applied to other problem domains where the data are better approximated by a Poisson distribution.

  16. 适应超厚料层烧结的设备改造%Improvement of Sintering Equipment to Adapt to Ultra-thick Bed Sintering Operation

    Institute of Scientific and Technical Information of China (English)

    郭建林

    2011-01-01

    Under the circumstances that the rolled steel market is weak, 1# sintering machine is improved to adapt to the ultra-thick bed and low-cost sintering operation, which has achieved good results.%在钢材市场持续疲软的情况下,为了适应烧结生产的低成本运行,对1号烧结机进行了适应厚料层烧结的设备改造,取得了很好的效果。

  17. Short-term adaptation improves the fermentation performance of Saccharomyces cerevisiae in the presence of acetic acid at low pH

    OpenAIRE

    Sànchez i Nogué, Violeta; Narayanan, Venkatachalam; Gorwa-Grauslund, Marie F

    2013-01-01

    The release of acetic acid due to deacetylation of the hemicellulose fraction during the treatment of lignocellulosic biomass contributes to the inhibitory character of the generated hydrolysates. In the present study, we identified a strain-independent adaptation protocol consisting of pre-cultivating the strain at pH 5.0 in the presence of at least 4 g L−1 acetic acid that enabled aerobic growth and improved fermentation performance of Saccharomyces cerevisiae cells at low pH (3.7) and in t...

  18. Improvement of Quality of Service (QoS in MISO-OFDM Systems Using Superposition Based Adaptive Modulation (SPAM and Space Frequency Block Coding (SFBC Technique

    Directory of Open Access Journals (Sweden)

    K.Vinoth Babu

    2013-06-01

    Full Text Available 4G based wireless communication systems require high data rate with high QoS with minimal system complexity. In wireless environment, as the effect of multipath fading increases, Bit Error Rate (BER also increases. To offer high data rate, the bandwidth has to be increased which is a limited resource. The best possible solution for obtaining high data rate is to combine Multi Input Multi Output (MIMO with OFDM. To ameliorate the performance of MIMO-OFDM systems over multipath fading channels, we use the concept of SFBC which retrieves the orthogonality property of OFDM signals in frequency selective fading channels. In frequency selective fading environment, adaptive modulation gives better performance than fixed modulated systems but with increased decoding complexity. Adaptive modulation implemented with SPAM offers less decoding complexity. Adaptive modulation combined with diversity schemes still improves the reliability of the system. In this paper, SPAM based SFBC is proposed with OFDM to give better performance with less decoding complexity. From the Simulationresults we can conclude that proposed system will have better performance compared to fixed modulated systems.

  19. Adapting and Implementing a Community Program to Improve Retention in Care among Patients with HIV in Southern Haiti: “Group of 6”

    Directory of Open Access Journals (Sweden)

    John A. Naslund

    2014-01-01

    Full Text Available Objective. In Mozambique, a patient-led Community ART Group model developed by Médecins Sans Frontières improved retention in care and adherence to antiretroviral therapy (ART among persons with HIV. We describe the adaptation and implementation of this model within the HIV clinic located in the largest public hospital in Haiti’s Southern Department. Methods. Our adapted model was named Group of 6. Hospital staff enabled stable patients with HIV receiving ART to form community groups with 4–6 members to facilitate monthly ART distribution, track progress and adherence, and provide support. Implementation outcomes included recruitment success, participant retention, group completion of monthly monitoring forms, and satisfaction surveys. Results. Over one year, 80 patients from nine communities enrolled into 15 groups. Six participants left to receive HIV care elsewhere, two moved away, and one died of a non-HIV condition. Group members successfully completed monthly ART distribution and returned 85.6% of the monthly monitoring forms. Members reported that Group of 6 made their HIV management easier and hospital staff reported that it reduced their workload. Conclusions. We report successful adaptation and implementation of a validated community HIV-care model in Southern Haiti. Group of 6 can reduce barriers to ART adherence, and will be integrated as a routine care option.

  20. Assessing damage cost estimation of urban pluvial flood risk as a mean of improving climate change adaptations investments

    DEFF Research Database (Denmark)

    Skovgård Olsen, Anders; Zhou, Qianqian; Linde, Jens Jørgen;

    measures. This study investigates three different methods for estimating the EAD based on a loglinear relation between the damage costs and the return periods, one of which has been used in previous studies. The results show with the increased amount of data points there appears to be a shift in the log...... in previous studies appears to be valid and is a good assumption. The EAD estimation can be simplified by having a single unit cost per flooded area which is multiplied with the extent of the flood. It does however depend on the lower threshold chosen in the estimation of the flood extent.......Estimating the expected annual damage (EAD) due to flooding in an urban area is of great interest for urban water managers and other stakeholders. It is a strong indicator for a given area showing how it will be affected by climate change and how much can be gained by implementing adaptation...

  1. An improved adaptive ACO meta heuristic for scheduling multimedia traffic across the 802.11e EDCA

    Science.gov (United States)

    Ditze, Michael; Becker, Markus

    2008-01-01

    This paper presents an adaptive near-optimal scheduler for multimedia traffic for the 802.11e Enhanced Distributed Channel Access (EDCA) medium access control scheme. The scheduler exploits the ant colony optimization (ACO) meta heuristic to tackle the challenge of packet scheduling. ACO is a biologically inspired algorithm that is known to find near-optimal solutions for combinatorial optimization problems. Thus, we expect that ACO scheduling produces more efficient schedules than comparable deterministic scheduling approaches at the expenses of a computational overhead it introduces. We compare ACO scheduling relevant deterministic scheduling approaches, and in particular the MLLF scheduler that is specifically designed for the needs of compressed multimedia applications. The purpose of the evaluation is twofold. It allows to draw conclusions on the feasibility of ACO scheduling for multimedia traffic while it serves as a benchmark to determine to what extent deterministic schedulers fall short of a near-optimal solution.

  2. Analysis of the spatial and temporal variation of seasonal snow accumulation in alpine catchments using airborne laser scanning : basic research for the adaptation of spatially distributed hydrological models to mountain regions

    International Nuclear Information System (INIS)

    Information about the spatial distribution of snow accumulation is a prerequisitefor adaptating hydro-meteorological models to achieve realistic simulations of therunoff from mountain catchments. Therefore, the spatial snow depthdistribution in complex topography of ice-free terrain and glaciers was investigatedusing airborne laser scanning (ALS) data. This thesis presents for the first time an analysis of the persistence and the variability of the snow patterns at the end of five accumulation seasons in a comparatively large catchment. ALS derived seasonal surface elevation changes on glaciers were compared to the actual snow depths calculated from ground penetrating radar (GPR) measurements. Areas of increased deviations. In the investigated region, the ALS-derived snow depths on most of the glacier surface do not deviate markedly from actual snow depths. 75% of a the total area showed low inter-annual variability of standardized snow depths at the end of the five accumulation seasons. The high inter-annual variability of snow depths could be attributed to changes in the ice cover within the investigated 10-yearperiod for much of the remaining area. Avalanches and snow sloughs continuously contribute to the accumulation on glaciers, but their share of the total snow covervolume is small. The assimilation of SWE maps calculated from ALS data in the adaptation of snow-hydrological models to mountain catchments improved the results not only for the but also for the simulated snow cover distribution and for the mass balance of the glaciers. The results demonstrate that ALS data are a beneficial source for extensive analysis of snow patterns and for modeling the runoff from high Alpine catchments.(author)

  3. Adaptive Image Denoising by Mixture Adaptation.

    Science.gov (United States)

    Luo, Enming; Chan, Stanley H; Nguyen, Truong Q

    2016-10-01

    We propose an adaptive learning procedure to learn patch-based image priors for image denoising. The new algorithm, called the expectation-maximization (EM) adaptation, takes a generic prior learned from a generic external database and adapts it to the noisy image to generate a specific prior. Different from existing methods that combine internal and external statistics in ad hoc ways, the proposed algorithm is rigorously derived from a Bayesian hyper-prior perspective. There are two contributions of this paper. First, we provide full derivation of the EM adaptation algorithm and demonstrate methods to improve the computational complexity. Second, in the absence of the latent clean image, we show how EM adaptation can be modified based on pre-filtering. The experimental results show that the proposed adaptation algorithm yields consistently better denoising results than the one without adaptation and is superior to several state-of-the-art algorithms. PMID:27416593

  4. Coping with climate change uncertainty for adaptation planning: An improved criterion for decision making under uncertainty using UKCP09

    Directory of Open Access Journals (Sweden)

    M. Green

    2014-01-01

    Analyses using sub-samples of the complete probabilistic dataset showed that the Green Z-score had comparable reproducibility to Laplace and improved reproducibility compared to other current decision criteria, and unlike Laplace is able to accommodate different risk attitudes.

  5. Adaptive and innovative Radiation Treatment FOR improving Cancer treatment outcomE (ARTFORCE); a randomized controlled phase II trial for individualized treatment of head and neck cancer

    International Nuclear Information System (INIS)

    Failure of locoregional control is the main cause of recurrence in advanced head and neck cancer. This multi-center trial aims to improve outcome in two ways. Firstly, by redistribution of the radiation dose to the metabolically most FDG-PET avid part of the tumour. Hereby, a biologically more effective dose distribution might be achieved while simultaneously sparing normal tissues. Secondly, by improving patient selection. Both cisplatin and Epidermal Growth Factor Receptor (EGFR) antibodies like Cetuximab in combination with Radiotherapy (RT) are effective in enhancing tumour response. However, it is unknown which patients will benefit from either agent in combination with irradiation. We will analyze the predictive value of biological markers and 89Zr-Cetuximab uptake for treatment outcome of chemoradiation with Cetuximab or cisplatin to improve patient selection. ARTFORCE is a randomized phase II trial for 268 patients with a factorial 2 by 2 design: cisplatin versus Cetuximab and standard RT versus redistributed RT. Cisplatin is dosed weekly 40 mg/m2 for 6 weeks. Cetuximab is dosed 250mg/m2 weekly (loading dose 400 mg/m2) for 6 weeks. The standard RT regimen consists of elective RT up to 54.25 Gy with a simultaneous integrated boost (SIB) to 70 Gy in 35 fractions in 6 weeks. Redistributed adaptive RT consists of elective RT up to 54.25 Gy with a SIB between 64-80 Gy in 35 fractions in 6 weeks with redistributed dose to the gross tumour volume (GTV) and clinical target volume (CTV), and adaptation of treatment for anatomical changes in the third week of treatment. Patients with locally advanced, biopsy confirmed squamous cell carcinoma of the oropharynx, oral cavity or hypopharynx are eligible. Primary endpoints are: locoregional recurrence free survival at 2 years, correlation of the median 89Zr-cetuximab uptake and biological markers with treatment specific outcome, and toxicity. Secondary endpoints are quality of life, swallowing function preservation

  6. Saccharomyces cerevisiae strain improvement using selection, mutation, and adaptation for the resistance to lignocellulose-derived fermentation inhibitor for ethanol production.

    Science.gov (United States)

    Jang, Youri; Lim, Younghoon; Kim, Keun

    2014-05-01

    Twenty-five Saccharomyces cerevisiae strains were screened for the highest sugar tolerance, ethanol-tolerance, ethanol production, and inhibitor resistance, and S. cerevisiae KL5 was selected as the best strain. Inhibitor cocktail (100%) was composed of 75 mM formic acid, 75 mM acetic acid, 30 mM furfural, 30 mM hydroxymethyl furfural (HMF), and 2.7 mM vanillin. The cells of strain KL5 were treated with γ-irradiation, and among the survivals, KL5- G2 with improved inhibitor resistance and the highest ethanol yield in the presence of inhibitor cocktail was selected. The KL5-G2 strain was adapted to inhibitor cocktail by sequential transfer of cultures to a minimal YNB medium containing increasing concentrations of inhibitor cocktail. After 10 times of adaptation, most of the isolated colonies could grow in YNB with 80% inhibitor cocktail, whereas the parental KL5 strain could not grow at all. Among the various adapted strains, the best strain (KL5-G2-A9) producing the highest ethanol yield in the presence of inhibitor cocktail was selected. In a complex YP medium containing 60% inhibitor cocktail and 5% glucose, the theoretical yield and productivity (at 48 h) of KL5- G2-A9 were 81.3% and 0.304 g/l/h, respectively, whereas those of KL5 were 20.8% and 0.072 g/l/h, respectively. KL5-G2-A9 reduced the concentrations of HMF, furfural, and vanillin in the medium in much faster rates than KL5. PMID:24608567

  7. Virtual temporal bone

    Institute of Scientific and Technical Information of China (English)

    QIU Ming-guo; ZHANG Shao-xiang; LIU Zheng-jin; TAN Li-wen; WANG Yu-su; DENG Jun-hui; TANG Ze-sheng

    2002-01-01

    Objective:To provide the virtual model of the temporal bone for improving 3-dimension (3D) visualization of the inner ear. Methods: Plastination technique was used to make equidistant serial thin sections 1.0 mm in thickness. On SGI workstation, a Contours+Marching Cubes algorithm was selected to reconstruct the temporal bone and intratemporal structures in 3D, then to view the middle ear, inner ear, and intratemporal structures which imitate the scenes observed by the traditional endoscopy. Results: The virtual model of the temporal bone was successfully constructed, with all reconstructed structures being represented individually or jointly and being rotated continuously in any plane. Virtual endoscopy improved 3D visualization of the middle ear, inner ear, and intratemporal structures. Conclusion: The reconstructed model can be used for the medical students to rehearse or review the surgeries on this part and for the surgeons to develop a new approach for operation. Virtual otoscopy stands as a promising new visualization technique for elucidating the structure and relation of the middle ear, inner ear, and intratemporal structures.

  8. A hybrid, auto-adaptive and rule-based multi-agent approach using evolutionary algorithms for improved searching

    Science.gov (United States)

    Izquierdo, Joaquín; Montalvo, Idel; Campbell, Enrique; Pérez-García, Rafael

    2016-08-01

    Selecting the most appropriate heuristic for solving a specific problem is not easy, for many reasons. This article focuses on one of these reasons: traditionally, the solution search process has operated in a given manner regardless of the specific problem being solved, and the process has been the same regardless of the size, complexity and domain of the problem. To cope with this situation, search processes should mould the search into areas of the search space that are meaningful for the problem. This article builds on previous work in the development of a multi-agent paradigm using techniques derived from knowledge discovery (data-mining techniques) on databases of so-far visited solutions. The aim is to improve the search mechanisms, increase computational efficiency and use rules to enrich the formulation of optimization problems, while reducing the search space and catering to realistic problems.

  9. Improved Transient Performance of a Fuzzy Modified Model Reference Adaptive Controller for an Interacting Coupled Tank System Using Real-Coded Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Asan Mohideen Khansadurai

    2014-01-01

    Full Text Available The main objective of the paper is to design a model reference adaptive controller (MRAC with improved transient performance. A modification to the standard direct MRAC called fuzzy modified MRAC (FMRAC is used in the paper. The FMRAC uses a proportional control based Mamdani-type fuzzy logic controller (MFLC to improve the transient performance of a direct MRAC. The paper proposes the application of real-coded genetic algorithm (RGA to tune the membership function parameters of the proposed FMRAC offline so that the transient performance of the FMRAC is improved further. In this study, a GA based modified MRAC (GAMMRAC, an FMRAC, and a GA based FMRAC (GAFMRAC are designed for a coupled tank setup in a hybrid tank process and their transient performances are compared. The results show that the proposed GAFMRAC gives a better transient performance than the GAMMRAC or the FMRAC. It is concluded that the proposed controller can be used to obtain very good transient performance for the control of nonlinear processes.

  10. Temporal aspects of copper homeostasis and its crosstalk with hormones

    Directory of Open Access Journals (Sweden)

    Lola ePeñarrubia

    2015-04-01

    Full Text Available To cope with the dual nature of copper as being essential and toxic for cells, plants temporarily adapt the expression of copper homeostasis components to assure its delivery to cuproproteins while avoiding the interference of potential oxidative damage derived from both copper uptake and photosynthetic reactions during light hours. The circadian clock participates in the temporal organization of coordination of plant nutrition adapting metabolic responses to the daily oscillations. This timely control improves plant fitness and reproduction and holds biotechnological potential to drive increased crop yields. Hormonal pathways, including those of abscisic acid, gibberellins, ethylene, auxins, and jasmonates are also under direct clock and light control, both in mono and dicotyledons. In this review, we focus on copper transport in Arabidopsis thaliana and Oryza sativa and the presumable role of hormones in metal homeostasis matching nutrient availability to growth requirements and preventing metal toxicity. The presence of putative hormone-dependent regulatory elements in the promoters of copper transporters genes suggests hormonal regulation to match special copper requirements during plant development. Spatial and temporal processes that can be affected by hormones include the regulation of copper uptake into roots, intracellular trafficking and compartmentalisation, and long-distance transport to developing vegetative and reproductive tissues. In turn, hormone biosynthesis and signalling are also influenced by copper availability, which suggests reciprocal regulation subjected to temporal control by the central oscillator of the circadian clock. This transcriptional regulatory network, coordinates environmental and hormonal signalling with developmental pathways to allow enhanced micronutrient acquisition efficiency.

  11. Development and applications of coherent imaging with improved temporal and spatial resolution; Developpement et applications de l'imagerie coherente aux rayons X a tres haute resolution spatiale et temporelle

    Energy Technology Data Exchange (ETDEWEB)

    Mokso, Rajmund

    2006-07-01

    This work has 2 purposes: the improvement of both temporal and spatial resolution of X-ray tomography. The first part is devoted to the technical aspects of the tomographic technique, particularly at the ESRF (European Synchrotron Radiation Facility) beamline ID19, and the application of the new acquisition scheme to the imaging of liquid foams. We have improved the temporal resolution and field of view of the setup, which allowed to obtain for the first time experimental data with good statistics on three dimensional liquid foams. In the second part of the thesis we have described the Kirkpatrick-Baez focusing system and its first applications. In terms of stability and image quality the developments presented in this part of the thesis provide valuable evidence for the feasibility of phase contrast tomography in magnifying geometry. Since the ultimate goal of this research is to improve the spatial resolution in tomography for applications, four different contributions are important for the characterization of the imaging system: 1) the thermal stability and mechanical imperfections, 2) effects of distortion induced by mirror imperfections, 3) effects of refraction on sample borders, and 4) phase propagation effects with the influence of the magnification. Each of these factors has been studied.

  12. Adaptation, plant evolution, and the fossil record

    Science.gov (United States)

    Knoll, A. H.; Niklas, K. J.

    1987-01-01

    The importance of adaptation in determining patterns of evolution has become an important focus of debate in evolutionary biology. As it pertains to paleobotany, the issue is whether or not adaptive evolution mediated by natural selection is sufficient to explain the stratigraphic distributions of taxa and character states observed in the plant fossil record. One means of addressing this question is the functional evaluation of stratigraphic series of plant organs set in the context of paleoenvironmental change and temporal patterns of floral composition within environments. For certain organ systems, quantitative estimates of biophysical performance can be made on the basis of structures preserved in the fossil record. Performance estimates for plants separated in time or space can be compared directly. Implicit in different hypotheses of the forces that shape the evolutionary record (e.g. adaptation, mass extinction, rapid environmental change, chance) are predictions about stratigraphic and paleoenvironmental trends in the efficacy of functional performance. Existing data suggest that following the evolution of a significant structural innovation, adaptation for improved functional performance can be a major determinant of evolutionary changes in plants; however, there are structural and development limits to functional improvement, and once these are reached, the structure in question may no longer figure strongly in selection until and unless a new innovation evolves. The Silurian-Devonian paleobotanical record is consistent with the hypothesis that the succession of lowland floodplain dominants preserved in the fossil record of this interval was determined principally by the repeated evolution of new taxa that rose to ecological importance because of competitive advantages conferred by improved biophysical performance. This does not seem to be equally true for Carboniferous-Jurassic dominants of swamp and lowland floodplain environments. In these cases

  13. Spatio-Temporal Equalizer for a Receiving-Antenna Feed Array

    Science.gov (United States)

    Mukai, Ryan; Lee, Dennis; Vilnrotter, Victor

    2010-01-01

    A spatio-temporal equalizer has been conceived as an improved means of suppressing multipath effects in the reception of aeronautical telemetry signals, and may be adaptable to radar and aeronautical communication applications as well. This equalizer would be an integral part of a system that would also include a seven-element planar array of receiving feed horns centered at the focal point of a paraboloidal antenna that would be nominally aimed at or near the aircraft that would be the source of the signal that one seeks to receive (see Figure 1). This spatio-temporal equalizer would consist mostly of a bank of seven adaptive finite-impulse-response (FIR) filters one for each element in the array - and the outputs of the filters would be summed (see Figure 2). The combination of the spatial diversity of the feedhorn array and the temporal diversity of the filter bank would afford better multipath-suppression performance than is achievable by means of temporal equalization alone. The seven-element feed array would supplant the single feed horn used in a conventional paraboloidal ground telemetry-receiving antenna. The radio-frequency telemetry signals re ceiv ed by the seven elements of the array would be digitized, converted to complex baseband form, and sent to the FIR filter bank, which would adapt itself in real time to enable reception of telemetry at a low bit error rate, even in the presence of multipath of the type found at many flight test ranges.

  14. Leveraging open-source technology and adapting open eLearning content to improve the knowledge and motivation of Ghana’s rural nurses

    Directory of Open Access Journals (Sweden)

    Lisa Mwaikambo

    2016-03-01

    Full Text Available Access to training opportunities is strongly correlated with health workers’ motivation because it enables health workers to take on more challenging duties. Mobile technology can be leveraged for professional development support by providing access to open education resources. Community Health Nurses (CHNs in Ghana are the frontline health workers of the Ghana Health Service (GHS and play a vital role in extending maternal and child health care to rural communities. However, as the lowest credentialed nurses, they are at the bottom of the GHS hierarchy. CHNs have limited opportunities for career advancement and report challenges with isolation and lack of resources. Leveraging open-source technology platforms and open eLearning content, the Care Community Hub (CCH project sought to address these barriers in CHN motivation by developing and deploying a mobile application (app, CHN on the Go, to CHNs in five rural districts. The app supports CHNs through tools for continuous learning, diagnostic decision-making, and improved nurse-supervisor interactions. This paper focuses on the adaptation and use of the open eLearning content to address CHNs’ motivation challenges and, ultimately, improve their knowledge and job performance as a result of having access to open education resources.

  15. Identifying Optimal Temporal Scale for the Correlation of AOD and Ground Measurements of PM2.5 to Improve the Modeling Performance in a Real-Time Air Quality Estimation System

    Science.gov (United States)

    Li,Hui; Faruque, Fazlay; Williams, Worth; Al-Hamdan, Mohammad; Luvall, Jeffrey; Crosson, William; Rickman, Douglas; Limaye, Ashutosh

    2008-01-01

    Aerosol optical depth (AOD), derived from satellite measurements using Moderate Resolution Imaging Spectrometer (MODIS), offers indirect estimates of particle matter. Research shows a significant positive correlation between satellite-based measurements of AOD and ground-based measurements of particulate matter with aerodynamic diameter less than or equal to 2.5 micrometers (PM2.5). In addition, satellite observations have also shown great promise in improving estimates of PM2.5 air quality surface. Research shows that correlations between AOD and ground PM2.5 are affected by a combination of many factors such as inherent characteristics of satellite observations, terrain, cloud cover, height of the mixing layer, and weather conditions, and thus might vary widely in different regions, different seasons, and even different days in a same location. Analysis of correlating AOD with ground measured PM2.5 on a day-to-day basis suggests the temporal scale, a number of immediate latest days for a given run's day, for their correlations needs to be considered to improve air quality surface estimates, especially when satellite observations are used in a real-time pollution system. The second reason is that correlation coefficients between AOD and ground PM2.5 cannot be predetermined and needs to be calculated for each day's run for a real-time system because the coefficients can vary over space and time. Few studies have been conducted to explore the optimal way to apply AOD data to improve model accuracies of PM2.5 surface estimation in a real-time air quality system. This paper discusses the best temporal scale to calculate the correlation of AOD and ground particle matter data to improve the results of pollution models in real-time system.

  16. An improved adaptive bit allocation algorithm for OFDM system%一种改进的OFD M系统自适应比特分配算法

    Institute of Scientific and Technical Information of China (English)

    魏巍; 安文东

    2014-01-01

    An adaptive bit allocation algorithm based on Hughes-Hartogs algorithm is proposed in this paper to improve the shortage of greedy algorithm which requires a large number of itera-tions.Under the constraint of bit error rata and the total number of transmission bit,the im-proved algorithm firstly uses the Chow algorithm to allocate some of the bits,and then uses the greedy algorithm to allocate the remaining bits to each subcarrier.When minimizing the total power by this algorithm,iterations of this algorithm are significantly less than that by the greedy algorithm.Computer simulation results show that,with fixed transmission rate,the iterations number of this improved algorithm is 7 .4%~34% of that of the greedy algorithm,and the per-formance of this algorithm is very close to that of the greedy algorithm.%针对贪婪算法迭代次数多的不足,提出一种基于 Hughes-Hartogs 算法的自适应比特分配算法。在误比特率和传输比特总数限定下,先使用Chow算法对每个子载波进行比特初始分配,然后再把余下的比特通过贪婪算法分配到各个子载波上,使总功率达到最小。仿真结果表明,在传输比特数一定的情况下,改进贪婪算法的迭代次数仅是贪婪算法的7.4%~34%,并且在性能上十分逼近贪婪算法。

  17. Fuzzy branching temporal logic.

    Science.gov (United States)

    Moon, Seong-ick; Lee, Kwang H; Lee, Doheon

    2004-04-01

    Intelligent systems require a systematic way to represent and handle temporal information containing uncertainty. In particular, a logical framework is needed that can represent uncertain temporal information and its relationships with logical formulae. Fuzzy linear temporal logic (FLTL), a generalization of propositional linear temporal logic (PLTL) with fuzzy temporal events and fuzzy temporal states defined on a linear time model, was previously proposed for this purpose. However, many systems are best represented by branching time models in which each state can have more than one possible future path. In this paper, fuzzy branching temporal logic (FBTL) is proposed to address this problem. FBTL adopts and generalizes concurrent tree logic (CTL*), which is a classical branching temporal logic. The temporal model of FBTL is capable of representing fuzzy temporal events and fuzzy temporal states, and the order relation among them is represented as a directed graph. The utility of FBTL is demonstrated using a fuzzy job shop scheduling problem as an example. PMID:15376850

  18. Adaptive Crowdsourcing and Improved Innovation

    DEFF Research Database (Denmark)

    Edgeman, Rick; Engell, Toke; Jensen, Nik Grewy;

    Crowdsourcing is central to enterprise open innovation efforts, providing a source of labor, funding, and ideas. Though use of crowdsourcing in selected environments is well understood, application in business-to-business (B2B) market environments has been limited. Selected reasons for this...

  19. Behavioral Adaptation and Acceptance

    NARCIS (Netherlands)

    Martens, M.H.; Jenssen, G.D.

    2012-01-01

    One purpose of Intelligent Vehicles is to improve road safety, throughput, and emissions. However, the predicted effects are not always as large as aimed for. Part of this is due to indirect behavioral changes of drivers, also called behavioral adaptation. Behavioral adaptation (BA) refers to uninte

  20. Behavioural adaptation and acceptance

    NARCIS (Netherlands)

    Martens, M.H.; Jenssen, G.D.; Eskandarian, A.

    2012-01-01

    One purpose of Intelligent Vehicles is to improve road safety, throughput, and emissions. However, the predicted effects are not always as large as aimed for. Part of this is due to indirect behavioral changes of drivers, also called behavioral adaptation. Behavioral adaptation (BA) refers to uninte

  1. Analysis on urban traffic status based on improved spatio-temporal Moran’s I∗%基于改进时空Moran’s I指数的道路交通状态特征分析*

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      定义时空对象代替空间对象作为基本研究单元,改进传统Moran’s I指数为时空Moran’s I指数,以便适于分析道路交通的时空特性;通过Moran散点图给出时空自相关意义下的交通流时空状态特征分类:拥堵聚集、畅通聚集、拥堵异质和畅通异质。为说明改进时空Moran’s I指数分析法的实际应用价值,以北京市二环快速路外环方向的车流速度数据为例,进行时空自相关指标计算,并从全局与局部自相关两个方面分析时空自相关指标所反映的交通状态时空分布与演化规律。%An improved Moran’s I method is proposed to describe the spatio temporal features of road traffic flow based on the traditional Moran’s I. The spatio temporal distribution classification of road traffic status including homogenous congested and uncongested traffic, heterogeneous congested and uncongested traffic is then given through Moran plotting graph. To verify the applicability of the proposed method, the traffic flow data along the second ring-shape urban expressway in Beijing is introduced for analysing the spatio temporal distribution and evolution of road traffic status from global and local autocorrelation through using the proposed method.

  2. Adaptive Lighting

    OpenAIRE

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive LightingAdaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled i...

  3. Improvement of adaptive fuzzy control for a photovoltaic/wind/diesel generating system; Taiyoko/furyoku/diesel hatsuden system no saitekigata fuzzy seigyo no kairyo

    Energy Technology Data Exchange (ETDEWEB)

    Nagaike, H.; Kenmoku, Y.; Sakakibara, T. [Toyohashi University of Technology, Aichi (Japan); Nakagawa, S. [Maizuru National College of Technology, Kyoto (Japan); Kawamoto, T. [Shizuoka University, Shizuoka (Japan).Faculty of Engineering

    1996-10-27

    The photovoltaic/wind/diesel generating system that uses a storage battery as auxiliary power has been proposed to supply power from the system to the independent area. In this system, it is important to generate no insufficient power from the viewpoint of effective energy utilization and minimize the fuel consumption of a diesel generator. Authors have proposed the adaptive fuzzy control that changes the shape of the membership function of input variables according to the parameter indicating the system state. However, a parameter was rapidly changed in the conventional method. This badly influences the control. Therefore, the way to determine the parameter that indicates the state of this system was improved. Assume that an input value is set to the average value between a certain point of time and the {Delta}t time as the method for determining a parameter. If the {Delta}t value is lower, the change in a membership function is more effective. As a result, a greater fuel reduction effect was obtained. 4 refs., 8 figs., 1 tab.

  4. Application of ALOS and Envisat Data in Improving Multi-Temporal InSAR Methods for Monitoring Damavand Volcano and Landslide Deformation in the Center of Alborz Mountains, North Iran

    Directory of Open Access Journals (Sweden)

    S. Vajedian

    2013-09-01

    Full Text Available InSAR capacity to detect slow deformation over terrain areas is limited by temporal and geometric decorrelations. Multitemporal InSAR techniques involving Persistent Scatterer (Ps-InSAR and Small Baseline (SBAS are recently developed to compensate the decorrelation problems. Geometric decorrelation in mountainous areas especially for Envisat images makes phase unwrapping process difficult. To improve this unwrapping problem, we first modified phase filtering to make the wrapped phase image as smooth as possible. In addition, in order to improve unwrapping results, a modified unwrapping method has been developed. This method includes removing possible orbital and tropospheric effects. Topographic correction is done within three-dimensional unwrapping, Orbital and tropospheric corrections are done after unwrapping process. To evaluate the effectiveness of our improved method we tested the proposed algorithm by Envisat and ALOS dataset and compared our results with recently developed PS software (StaMAPS. In addition we used GPS observations for evaluating the modified method. The results indicate that our method improves the estimated deformation significantly.

  5. Diffusion Adaptation over Networks

    CERN Document Server

    Sayed, Ali H

    2012-01-01

    Adaptive networks are well-suited to perform decentralized information processing and optimization tasks and to model various types of self organized and complex behavior encountered in nature. Adaptive networks consist of a collection of agents with processing and learning abilities. The agents are linked together through a connection topology, and they cooperate with each other through local interactions to solve distributed inference problems in real-time. The continuous diffusion of information across the network enables agents to adapt their performance in relation to changing data and network conditions; it also results in improved adaptation and learning performance relative to non-cooperative networks. This article provides an overview of diffusion strategies for adaptation and learning over networks. The article is divided into several sections: 1. Motivation; 2. Mean-Square-Error Estimation; 3. Distributed Optimization via Diffusion Strategies; 4. Adaptive Diffusion Strategies; 5. Performance of Ste...

  6. A SCORING SYSTEM TO IMPROVE DECISION MAKING AND OUTCOMES IN THE ADAPTATION OF RECENTLY CAPTURED WHITE RHINOCEROSES (CERATOTHERIUM SIMUM) TO CAPTIVITY.

    Science.gov (United States)

    Miller, Michele; Kruger, Milandie; Kruger, Marius; Olea-Popelka, Francisco; Buss, Peter

    2016-04-01

    Ninety-four subadult and adult white rhinoceroses (Ceratotherium simum) were captured between February and October, 2009-11, in Kruger National Park and placed in holding bomas prior to translocation to other locations within South Africa. A simple three-category system was developed based on appetite, fecal consistency/volume, and behavior to assess adaptation to bomas. Individual animal and group daily median scores were used to determine trends and when rhinoceroses had successfully adapted to the boma. Seventeen rhinoceroses did not adapt to boma confinement, and 16 were released (1 mortality). No differences in boma scores were observed between rhinoceroses that adapted and those that did not, until day 8, when the first significant differences were observed (adapted score=13 versus nonadapted score=10). The time to reach a boma score determined as successful adaptation (median 19 d) matched subjective observations, which was approximately 3 wk for most rhinoceroses. Unsuccessful adaptation was indicated by an individual boma score of less than 15, typically during the first 2 wk, or a declining trend in scores within the first 7-14 d. This scoring system can be used for most locations and could also be easily adapted to other areas in which rhinoceroses are held in captivity. This tool also provides important information for assessing welfare in newly captured rhinoceroses. PMID:26845302

  7. A SCORING SYSTEM TO IMPROVE DECISION MAKING AND OUTCOMES IN THE ADAPTATION OF RECENTLY CAPTURED WHITE RHINOCEROSES (CERATOTHERIUM SIMUM) TO CAPTIVITY.

    Science.gov (United States)

    Miller, Michele; Kruger, Milandie; Kruger, Marius; Olea-Popelka, Francisco; Buss, Peter

    2016-04-01

    Ninety-four subadult and adult white rhinoceroses (Ceratotherium simum) were captured between February and October, 2009-11, in Kruger National Park and placed in holding bomas prior to translocation to other locations within South Africa. A simple three-category system was developed based on appetite, fecal consistency/volume, and behavior to assess adaptation to bomas. Individual animal and group daily median scores were used to determine trends and when rhinoceroses had successfully adapted to the boma. Seventeen rhinoceroses did not adapt to boma confinement, and 16 were released (1 mortality). No differences in boma scores were observed between rhinoceroses that adapted and those that did not, until day 8, when the first significant differences were observed (adapted score=13 versus nonadapted score=10). The time to reach a boma score determined as successful adaptation (median 19 d) matched subjective observations, which was approximately 3 wk for most rhinoceroses. Unsuccessful adaptation was indicated by an individual boma score of less than 15, typically during the first 2 wk, or a declining trend in scores within the first 7-14 d. This scoring system can be used for most locations and could also be easily adapted to other areas in which rhinoceroses are held in captivity. This tool also provides important information for assessing welfare in newly captured rhinoceroses.

  8. Delay synchronization of temporal Boolean networks

    Science.gov (United States)

    Wei, Qiang; Xie, Cheng-jun; Liang, Yi; Niu, Yu-jun; Lin, Da

    2016-01-01

    This paper investigates the delay synchronization between two temporal Boolean networks base on semi-tensor product method, which improve complete synchronization. Necessary and sufficient conditions for delay synchronization are drawn base on algebraic expression of temporal Boolean networks. A example is presented to show the effectiveness of theoretical analysis.

  9. 改进的自适应混沌差分进化算法%Improved Adaptive Chaotic Differential Evolution Algorithm

    Institute of Scientific and Technical Information of China (English)

    王涛; 王焕

    2013-01-01

      为了提高差分进化算法的寻优速度、克服启发式算法常见的早熟收敛问题,提出一种基于帐篷映射(Tent)的自适应混沌嵌入式差分进化算法(CLSDE)。算法采用 Tent 映射生成的混沌序列来取代基本 DE 算法选择操作中的随机数,充分利用了混沌运动的随机性、遍历性和规律性。通过与混沌 PSO 算法与普通的 DE 算法比较,测试函数仿真结果表明,该算法具有良好的全局搜索能力,寻优精度较高,收敛速度快,鲁棒性好。%In order to improve the differential evolution algorithm for optimum speed and overcome the heuristic algorithm common premature convergence problem is proposed based on a Tent mapping (Tent) of adaptive chaotic embedded differential evolution algorithm (CLSDE). Tent mapping algorithm using of the generation of chaotic sequence to replace basic DE algorithm to select the operation of the random, and make full use of the chaotic motions of the randomness, ergodicity and regularity, so it can smooth out the problem of local precocious and rapid speed up its global convergence speed. Through the and chaos PSO algorithm and the ordinary DE comparison algorithm, the simulation results show that the new algorithm in the solution precision, stability and convergence borrows and good performance.

  10. Temporal subtraction contrast-enhanced dedicated breast CT

    Science.gov (United States)

    Gazi, Peymon M.; Aminololama-Shakeri, Shadi; Yang, Kai; Boone, John M.

    2016-09-01

    The development of a framework of deformable image registration and segmentation for the purpose of temporal subtraction contrast-enhanced breast CT is described. An iterative histogram-based two-means clustering method was used for the segmentation. Dedicated breast CT images were segmented into background (air), adipose, fibroglandular and skin components. Fibroglandular tissue was classified as either normal or contrast-enhanced then divided into tiers for the purpose of categorizing degrees of contrast enhancement. A variant of the Demons deformable registration algorithm, intensity difference adaptive Demons (IDAD), was developed to correct for the large deformation forces that stemmed from contrast enhancement. In this application, the accuracy of the proposed method was evaluated in both mathematically-simulated and physically-acquired phantom images. Clinical usage and accuracy of the temporal subtraction framework was demonstrated using contrast-enhanced breast CT datasets from five patients. Registration performance was quantified using normalized cross correlation (NCC), symmetric uncertainty coefficient, normalized mutual information (NMI), mean square error (MSE) and target registration error (TRE). The proposed method outperformed conventional affine and other Demons variations in contrast enhanced breast CT image registration. In simulation studies, IDAD exhibited improvement in MSE (0-16%), NCC (0-6%), NMI (0-13%) and TRE (0-34%) compared to the conventional Demons approaches, depending on the size and intensity of the enhancing lesion. As lesion size and contrast enhancement levels increased, so did the improvement. The drop in the correlation between the pre- and post-contrast images for the largest enhancement levels in phantom studies is less than 1.2% (150 Hounsfield units). Registration error, measured by TRE, shows only submillimeter mismatches between the concordant anatomical target points in all patient studies. The algorithm was

  11. Temporal subtraction contrast-enhanced dedicated breast CT.

    Science.gov (United States)

    Gazi, Peymon M; Aminololama-Shakeri, Shadi; Yang, Kai; Boone, John M

    2016-09-01

    The development of a framework of deformable image registration and segmentation for the purpose of temporal subtraction contrast-enhanced breast CT is described. An iterative histogram-based two-means clustering method was used for the segmentation. Dedicated breast CT images were segmented into background (air), adipose, fibroglandular and skin components. Fibroglandular tissue was classified as either normal or contrast-enhanced then divided into tiers for the purpose of categorizing degrees of contrast enhancement. A variant of the Demons deformable registration algorithm, intensity difference adaptive Demons (IDAD), was developed to correct for the large deformation forces that stemmed from contrast enhancement. In this application, the accuracy of the proposed method was evaluated in both mathematically-simulated and physically-acquired phantom images. Clinical usage and accuracy of the temporal subtraction framework was demonstrated using contrast-enhanced breast CT datasets from five patients. Registration performance was quantified using normalized cross correlation (NCC), symmetric uncertainty coefficient, normalized mutual information (NMI), mean square error (MSE) and target registration error (TRE). The proposed method outperformed conventional affine and other Demons variations in contrast enhanced breast CT image registration. In simulation studies, IDAD exhibited improvement in MSE (0-16%), NCC (0-6%), NMI (0-13%) and TRE (0-34%) compared to the conventional Demons approaches, depending on the size and intensity of the enhancing lesion. As lesion size and contrast enhancement levels increased, so did the improvement. The drop in the correlation between the pre- and post-contrast images for the largest enhancement levels in phantom studies is less than 1.2% (150 Hounsfield units). Registration error, measured by TRE, shows only submillimeter mismatches between the concordant anatomical target points in all patient studies. The algorithm was

  12. SPARTUVIX II: An improved x-ray ultraviolet spectrograph with temporal and spatial capabilities for indirect drive inertial confinement fusion experiments (abstract)

    International Nuclear Information System (INIS)

    An improved version of the initial x-ray ultraviolet spectrograph SPARTUVIX1 has been developed to record the time evolution of spatially resolved spectra in the soft x-ray range (from 30 to 300 Angstrom). This diagnostic can be applied to the new class of laser produced plasma experiments now performed in order to better understand the physical evolution of x-ray indirect drive plasmas. Instead of a one-dimensional streak camera used for the first version, a new widely used 2-D soft x-ray time gated imager allows us to follow the time evolution of the spatially resolved soft x-ray spectra. This instrument was designed for plastic foam soft x-ray opacity measurements. The soft x-rays, emitted by an auxiliary radiography laser plasma source, are transmitted through the foam and dispersed into two parts (+1 and -1 order of the transmission grating). Each dispersed spectrum is placed on two different gated striplines of the soft x-ray imager and thus recorded at two different times (exposure time 300 ps, adjustable interframe 600 ps). The spatial resolution is obtained with a slit added in front of the spectrograph, that images the plasma onto the detector with a magnification ratio of 15 and a spatial resolution of 50 μm. A detailed description of this instrument and the main results obtained for two different plastic foam opacity measurements (undoped and doped with chlorine) will be presented. This work is supported by European Community Contract No. CEE/CHGF-CT-92-0016. copyright 1997 American Institute of Physics

  13. Improved Dynamic Adaptive Clone Selection Algorithm%改进型动态自适应克隆选择算法

    Institute of Scientific and Technical Information of China (English)

    刘俊辉; 李娜

    2012-01-01

    At present, clone selection algorithm is an intelligent optimization algorithm which is widely applied However, traditional clone selection algorithm has the deficiency of blind selection. In order to overcome this deficiency, an improved dynamic adaptive clone selection algorithm was proposed. Firstly, according to affinity, antibody population was dynamically divided into memory antibody units and general antibody units. And then, variation probability of each antibody which was dynamically corrected by means of affinity was used to carry out variation operatioa Subsequently, antibody population was adjusted by sphere crossover to generate new population. The selection and the global search speed of the proposed algorithm are improved through the afore-mentioned strategies. The effectiveness and the feasibility of the proposed algorithm are verified by simulation results.%克隆选择算法是日前应用较广的一种智能优化算法,但它在选择时具有一定的盲目性.为了克服它的这个不足,论文提出了一种改进型动态自适应克隆选择算法.在该算法中,首先根据抗体的亲和度将抗体群动态分为记忆单元和一般抗体单元,然后再借助抗体的亲和度修正抗体的变异概率并根据修正后的变异概率进行变异操作,紧接着以球面杂交方式对种群进行调整以产生新的种群.上述策略使得该算法在选择时具有一定的针对性,从而加快了它的全局搜索速度,仿真结果验证了所提算法的有效性、可行性.

  14. Updating representations of temporal intervals.

    Science.gov (United States)

    Danckert, James; Anderson, Britt

    2015-12-01

    Effectively engaging with the world depends on accurate representations of the regularities that make up that world-what we call mental models. The success of any mental model depends on the ability to adapt to changes-to 'update' the model. In prior work, we have shown that damage to the right hemisphere of the brain impairs the ability to update mental models across a range of tasks. Given the disparate nature of the tasks we have employed in this prior work (i.e. statistical learning, language acquisition, position priming, perceptual ambiguity, strategic game play), we propose that a cognitive module important for updating mental representations should be generic, in the sense that it is invoked across multiple cognitive and perceptual domains. To date, the majority of our tasks have been visual in nature. Given the ubiquity and import of temporal information in sensory experience, we examined the ability to build and update mental models of time. We had healthy individuals complete a temporal prediction task in which intervals were initially drawn from one temporal range before an unannounced switch to a different range of intervals. Separate groups had the second range of intervals switch to one that contained either longer or shorter intervals than the first range. Both groups showed significant positive correlations between perceptual and prediction accuracy. While each group updated mental models of temporal intervals, those exposed to shorter intervals did so more efficiently. Our results support the notion of generic capacity to update regularities in the environment-in this instance based on temporal information. The task developed here is well suited to investigations in neurological patients and in neuroimaging settings. PMID:26303026

  15. Adaptive Lighting

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... distributed differently into an architectural body. We also examine what might occur when light is dynamic and able to change colour, intensity and direction, and when it is adaptive and can be brought into interaction with its surroundings. In short, what happens to an architectural space when artificial...

  16. ADAPTIVE TRILATERAL FILTER FOR IN-LOOP FILTERING

    Directory of Open Access Journals (Sweden)

    Akitha Kesireddy

    2014-07-01

    Full Text Available High Efficiency Video Coding (HEVC has achieved significant coding efficiency improvement beyond existing video coding standard by employing several new coding tools. Deblocking Filter, Sample Adaptive Offset (SAO and Adaptive Loop Filter (ALF for in-loop filtering are currently introduced for the HEVC standard. However, these filters are implemented in spatial domain despite the fact of temporal correlation within video sequences. To reduce the artifacts and better align object boundaries in video, a proposed algorithm in in-loop filtering is proposed. The proposed algorithm is implemented in HM-11.0 software. This proposed algorithm allows an average bitrate reduction of about 0.7% and improves the PSNR of the decoded frame by 0.05%, 0.30% and 0.35% in luminance and chroma.

  17. Selection, adaptation, and predictive information in changing environments

    Science.gov (United States)

    Feltgen, Quentin; Nemenman, Ilya

    2014-03-01

    Adaptation by means of natural selection is a key concept in evolutionary biology. Individuals better matched to the surrounding environment outcompete the others. This increases the fraction of the better adapted individuals in the population, and hence increases its collective fitness. Adaptation is also prominent on the physiological scale in neuroscience and cell biology. There each individual infers properties of the environment and changes to become individually better, improving the overall population as well. Traditionally, these two notions of adaption have been considered distinct. Here we argue that both types of adaptation result in the same population growth in a broad class of analytically tractable population dynamics models in temporally changing environments. In particular, both types of adaptation lead to subextensive corrections to the population growth rates. These corrections are nearly universal and are equal to the predictive information in the environment time series, which is also the characterization of the time series complexity. This work has been supported by the James S. McDonnell Foundation.

  18. a New Spatial and Temporal Fusion Model

    Science.gov (United States)

    Wang, Jing; Huang, Bo

    2016-06-01

    As Moderate Resolution Imaging Spectroradiometer (MODIS) and Enhanced Thematic Mapper Plus (ETM+) has a tradeoff between the high temporal resolution and high spatial resolution, this paper proposed a spatial and temporal model with auto-regression error correction (AREC) method to blend the two types of images in order to obtain the composed image with both high spatial and temporal resolution. Experiments and validation were conducted on a data set located in Shenzhen, China and compared with Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) in several objective indexes and visual analysis. It was found that AREC could effectively predict the land cover changes and the fusion results had better performances versus the ones of STARFM.

  19. An adaptive algorithm for pass adaptation in plate rolling

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new algorithm for pass adaptation in plate rolling is developed to improve thickness accuracy of plate products. The feature of the algorithm is that it uses the measured data rather than the schedule calculated data in adaptation, which leads to notable improvementin prediction accuracy of the rolling parameters and thickness accuracy of products can be improved accordingly. Results show that this adaptive algorithm is effective in practice.

  20. Adaptive Architectural Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Kirkegaard, Poul Henning

    2010-01-01

    Recent years have seen an increasing variety of applications of adaptive architectural structures for improvement of structural performance by recognizing changes in their environments and loads, adapting to meet goals, and using past events to improve future performance or maintain serviceability....... The general scopes of this paper are to develop a new adaptive kinetic architectural structure, particularly a reconfigurable architectural structure which can transform body shape from planar geometries to hyper-surfaces using different control strategies, i.e. a transformation into more than one or two...... different shape alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock- up concept...

  1. Integrating adaptive governance and participatory multicriteria methods: a framework for climate adaptation governance

    OpenAIRE

    Stefania Munaretto; Giuseppina Siciliano; Margherita E. Turvani

    2014-01-01

    Climate adaptation is a dynamic social and institutional process where the governance dimension is receiving growing attention. Adaptive governance is an approach that promises to reduce uncertainty by improving the knowledge base for decision making. As uncertainty is an inherent feature of climate adaptation, adaptive governance seems to be a promising approach for improving climate adaptation governance. However, the adaptive governance literature has so far paid little attention to decisi...

  2. Changes of water demand - possible adaptation of agricultural crops and management options to improve water use efficiency in the Marchfeld area

    Science.gov (United States)

    Thaler, S.; Eitzinger, J.; Dubrovsky, M.; Trnka, M.

    2009-04-01

    The main objective of this study was to determine the vulnerability of current agricultural cropping systems in the Marchfeld region to climate change. The investigation area Marchfeld is located in the north-eastern (NE) part of Austria and is characterized by a semi-arid climate with low annual rainfall. It is one of the driest regions in the country, but also one of the main field crop production areas. The soil conditions in Marchfeld demonstrate a significant spatial variability, which include soils with low to moderate water-storage capacities. Higher temperatures in the next decades imply higher evaporation and consequently higher water demand for the crops. The phenological development rates of the cultivars will accelerate and an increase of heat stress as well as drought stress can be expected. These points influence intense the water balance and subsequently the yield of the crops in the investigation area. In order to improve water use efficiency under those changing conditions, a shift of average sowing dates and an adjustment of tillage were analyzed. The DSSAT cropping system model was applied for winter wheat and spring barley to assess potential yield under climate scenarios for NE Austria. The scenarios were carried out with ECHAM5, HadCM3 and NCAR PCM global circulation models (GCMs) for present conditions (reference period 1961-1990) and 2035's (2021-2050), based on SRES-A1B emission scenarios. Yield model simulations were done for all defined scenarios (climate, management, crop) and different soil classes. The simulations contain the CO2 fertilizing effect, rain fed farming, adapted sowing date and contemporary crops without consideration of potential profit cuts caused by pest or diseases. Simulation results indicate that climate change will force a delay of the sowing date for winter wheat of maximal 14 days in October. In case of spring barley, climate change allows an earlier sowing date in spring (up to 14 days). Both crops show a

  3. Foreseen hydrological changes drive efforts to formulate water balance improvement measures as part of the management options of adaptation at Lake Balaton, Hungary

    Science.gov (United States)

    Molnar, Gabor; Kutics, Karoly

    2013-04-01

    Located in Western Hungary, Lake Balaton (LB) is one of the shallowest large lakes of the world. The catchment area including the lake is 5775 km2, only 10 times more than the lake surface area of 593 km2. This relatively small catchment area and the relatively dry climate results in high vulnerability of the lake water budget to any hydro-meteorological changes. Due to the combined effects of planned water quality protection measures (refer to adjoining article on LB water quality) water quality was not as serious a concern over the last 15 years. However, a new and potentially more damaging threat, decreasing water level started to emerge in 2000. The natural water budget was negative half of the time, i.e. 6 years in the last 12 years. It hadn't occurred in the previous 80 years, since 1921, the year from which detailed meteorological data on the area are available. This new phenomenon raised and continues to raise serious sustainability concerns in the Lake Balaton area requiring better understanding of climatic changes and their foreseen impacts on hydrological and ecological processes that would lead decision makers to formulate the appropriate vulnerability and adaptation policies. Based on the common methodologies of the EULAKES project, present state of the hydrological conditions was analyzed as well as qualitative vulnerability assessment carried out to the area. Using the climate scenarios developed by the project partner Austrian Institute of Technology, calculations on water budget changes was possible. It is estimated that by the middle of the 21st century the lake will experience a drastic drop in the inflow and, accompanied by the increased evaporation, it is likely that years without outflow and serious drops in water-level would occur. The increased frequency of unfavorable water deficit will cause not only ecological, but also socio-economic conflicts in the multipurpose usage of the lake. Therefore, a qualitative vulnerability assessment was

  4. Robust Adaptive Control

    Science.gov (United States)

    Narendra, K. S.; Annaswamy, A. M.

    1985-01-01

    Several concepts and results in robust adaptive control are are discussed and is organized in three parts. The first part surveys existing algorithms. Different formulations of the problem and theoretical solutions that have been suggested are reviewed here. The second part contains new results related to the role of persistent excitation in robust adaptive systems and the use of hybrid control to improve robustness. In the third part promising new areas for future research are suggested which combine different approaches currently known.

  5. Adaptive Lighting

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... the investigations of lighting scenarios carried out in two test installations: White Cube and White Box. The test installations are discussed as large-scale experiential instruments. In these test installations we examine what could potentially occur when light using LED technology is integrated and...

  6. Adaptation investments and homeownership

    DEFF Research Database (Denmark)

    Hansen, Jørgen Drud; Skak, Morten

    2008-01-01

    This article develops a model where ownership improves efficiency of the housing market as it enhances the utility of housing consumption for some consumers. The model is based on an extended Hotelling-Lancaster utility approach in which the ideal variant of housing is obtainable only by adapting...... the home through a supplementary investment. Ownership offers low costs of adaptation, but has high contract costs compared with renting. Consumers simultaneously decide housing demand and tenure, and because of the different cost structure only consumers with strong preferences for individual adaptation...

  7. [Adaptive optics for ophthalmology].

    Science.gov (United States)

    Saleh, M

    2016-04-01

    Adaptive optics is a technology enhancing the visual performance of an optical system by correcting its optical aberrations. Adaptive optics have already enabled several breakthroughs in the field of visual sciences, such as improvement of visual acuity in normal and diseased eyes beyond physiologic limits, and the correction of presbyopia. Adaptive optics technology also provides high-resolution, in vivo imaging of the retina that may eventually help to detect the onset of retinal conditions at an early stage and provide better assessment of treatment efficacy.

  8. Adaptive Computing.

    Science.gov (United States)

    Harrell, William

    1999-01-01

    Provides information on various adaptive technology resources available to people with disabilities. (Contains 19 references, an annotated list of 129 websites, and 12 additional print resources.) (JOW)

  9. ADAPT Dataset

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Diagnostics and Prognostics Testbed (ADAPT) Project Lead: Scott Poll Subject Fault diagnosis in electrical power systems Description The Advanced...

  10. Using the collaborative intervention planning framework to adapt a health-care manager intervention to a new population and provider group to improve the health of people with serious mental illness

    OpenAIRE

    Cabassa, Leopoldo J.; Gomes, Arminda P.; Meyreles, Quisqueya; Capitelli, Lucia; Younge, Richard; Dragatsi, Dianna; Alvarez, Juana; Manrique, Yamira; Lewis-Fernández, Roberto

    2014-01-01

    Background Health-care manager interventions improve the physical health of people with serious mental illness (SMI) and could be widely implemented in public mental health clinics. Local adaptations and customization may be needed to increase the reach of these interventions in the public mental health system and across different racial and ethnic communities. In this study, we describe how we used the collaborative intervention planning framework to customize an existing health-care manager...

  11. Adaptive sensor fusion

    Science.gov (United States)

    Kadar, Ivan

    1995-07-01

    A perceptual reasoning system adaptively extracting, associating, and fusing information from multiple sources, at various levels of abstraction, is considered as the building block for the next generation of surveillance systems. A system architecture is presented which makes use of both centralized and distributed predetection fusion combined with intelligent monitor and control coupling both on-platform and off-board track and decision level fusion results. The goal of this system is to create a `gestalt fused sensor system' whose information product is greater than the sum of the information products from the individual sensors and has performance superior to either individual or a sub-group of combined sensors. The application of this architectural concept to the law enforcement arena (e.g. drug interdiction) utilizing multiple spatially and temporally diverse surveillance platforms and/or information sources, is used to illustrate the benefits of the adaptive perceptual reasoning system concept.

  12. Adaptive method of lines

    CERN Document Server

    Saucez, Ph

    2001-01-01

    The general Method of Lines (MOL) procedure provides a flexible format for the solution of all the major classes of partial differential equations (PDEs) and is particularly well suited to evolutionary, nonlinear wave PDEs. Despite its utility, however, there are relatively few texts that explore it at a more advanced level and reflect the method''s current state of development.Written by distinguished researchers in the field, Adaptive Method of Lines reflects the diversity of techniques and applications related to the MOL. Most of its chapters focus on a particular application but also provide a discussion of underlying philosophy and technique. Particular attention is paid to the concept of both temporal and spatial adaptivity in solving time-dependent PDEs. Many important ideas and methods are introduced, including moving grids and grid refinement, static and dynamic gridding, the equidistribution principle and the concept of a monitor function, the minimization of a functional, and the moving finite elem...

  13. AdapterRemoval v2

    DEFF Research Database (Denmark)

    Schubert, Mikkel; Lindgreen, Stinus; Orlando, Ludovic Antoine Alexandre

    2016-01-01

    BACKGROUND: As high-throughput sequencing platforms produce longer and longer reads, sequences generated from short inserts, such as those obtained from fossil and degraded material, are increasingly expected to contain adapter sequences. Efficient adapter trimming algorithms are also needed to...... process the growing amount of data generated per sequencing run. FINDINGS: We introduce AdapterRemoval v2, a major revision of AdapterRemoval v1, which introduces (i) striking improvements in throughput, through the use of single instruction, multiple data (SIMD; SSE1 and SSE2) instructions and multi......-threading support, (ii) the ability to handle datasets containing reads or read-pairs with different adapters or adapter pairs, (iii) simultaneous demultiplexing and adapter trimming, (iv) the ability to reconstruct adapter sequences from paired-end reads for poorly documented data sets, and (v) native gzip and...

  14. Advances in temporal logic

    CERN Document Server

    Fisher, Michael; Gabbay, Dov; Gough, Graham

    2000-01-01

    Time is a fascinating subject that has captured mankind's imagination from ancient times to the present. It has been, and continues to be studied across a wide range of disciplines, from the natural sciences to philosophy and logic. More than two decades ago, Pnueli in a seminal work showed the value of temporal logic in the specification and verification of computer programs. Today, a strong, vibrant international research community exists in the broad community of computer science and AI. This volume presents a number of articles from leading researchers containing state-of-the-art results in such areas as pure temporal/modal logic, specification and verification, temporal databases, temporal aspects in AI, tense and aspect in natural language, and temporal theorem proving. Earlier versions of some of the articles were given at the most recent International Conference on Temporal Logic, University of Manchester, UK. Readership: Any student of the area - postgraduate, postdoctoral or even research professor ...

  15. Temporal scaling in information propagation

    Science.gov (United States)

    Huang, Junming; Li, Chao; Wang, Wen-Qiang; Shen, Hua-Wei; Li, Guojie; Cheng, Xue-Qi

    2014-06-01

    For the study of information propagation, one fundamental problem is uncovering universal laws governing the dynamics of information propagation. This problem, from the microscopic perspective, is formulated as estimating the propagation probability that a piece of information propagates from one individual to another. Such a propagation probability generally depends on two major classes of factors: the intrinsic attractiveness of information and the interactions between individuals. Despite the fact that the temporal effect of attractiveness is widely studied, temporal laws underlying individual interactions remain unclear, causing inaccurate prediction of information propagation on evolving social networks. In this report, we empirically study the dynamics of information propagation, using the dataset from a population-scale social media website. We discover a temporal scaling in information propagation: the probability a message propagates between two individuals decays with the length of time latency since their latest interaction, obeying a power-law rule. Leveraging the scaling law, we further propose a temporal model to estimate future propagation probabilities between individuals, reducing the error rate of information propagation prediction from 6.7% to 2.6% and improving viral marketing with 9.7% incremental customers.

  16. Immunological perspectives of temporal lobe seizures.

    Science.gov (United States)

    Liimatainen, Suvi; Lehtimäki, Kai; Kai, Lehtimäki; Palmio, Johanna; Johanna, Palmio; Alapirtti, Tiina; Tiina, Alapirtti; Peltola, Jukka; Jukka, Peltola

    2013-10-15

    The temporal lobes are affected in many different neurological disorders, such as neurodegenerative diseases, viral and immunological encephalitides, and epilepsy. Both experimental and clinical evidence suggests a different inflammatory response to seizures in patients with temporal lobe epilepsy (TLE) in comparison to those with extra-TLE (XTLE). Proinflammatory cytokines and several autoantibodies have been shown to be associated with TLE compared to other epilepsy types suggesting the specific role and structure of the temporal lobe. Abundant experience suggests that activation of both innate and adaptive immunity is associated with epilepsy, particularly refractory focal epilepsy. Limbic encephalitis often triggers temporal lobe seizures, and a proportion of these disorders are immune-mediated. Histological evidence shows activation of specific inflammatory pathways in resected temporal lobes of epileptic patients, and certain epileptic disorders have shown increased incidence in patients with autoimmune diseases. Rapid activation of proinflammatory cytokines is observed after single seizures, but there is also evidence of chronic overproduction of cytokines and other inflammatory mediators in patients with TLE, suggesting a neuromodulatory role of inflammation in epilepsy. In this review we summarize current data on the presence and the role of immunological factors in temporal lobe seizures, and their possible involvement in epileptogenesis. PMID:23998423

  17. An ‘innovation-cycle framework’ of integrated agricultural knowledge system and innovation for improving farmers’climate change adaptation and risk mitigation capacities

    DEFF Research Database (Denmark)

    Rahman, Md Zillur

    2015-01-01

    The main objective of this paper is to present a new ‘innovation-cycle’ integrated conceptual framework of ‘TVET-adaptive AKSI’ (TVET: Technical and Vocational Education and Training; AKSI: Agricultural Knowledge System and Innovation). Thus the aim here is to discuss from existing body of litera......The main objective of this paper is to present a new ‘innovation-cycle’ integrated conceptual framework of ‘TVET-adaptive AKSI’ (TVET: Technical and Vocational Education and Training; AKSI: Agricultural Knowledge System and Innovation). Thus the aim here is to discuss from existing body...... and the increased risks of safe agricultural food production, sustainable environment and health, it will be unprecedented challenges due to increasing demand for safe food supply for future growing population in Bangladesh. Studies show that producers (farmers) are still lagging behind with lack of necessary...

  18. Asimovian Adaptive Agents

    CERN Document Server

    Gordon, D F

    2011-01-01

    The goal of this research is to develop agents that are adaptive and predictable and timely. At first blush, these three requirements seem contradictory. For example, adaptation risks introducing undesirable side effects, thereby making agents' behavior less predictable. Furthermore, although formal verification can assist in ensuring behavioral predictability, it is known to be time-consuming. Our solution to the challenge of satisfying all three requirements is the following. Agents have finite-state automaton plans, which are adapted online via evolutionary learning (perturbation) operators. To ensure that critical behavioral constraints are always satisfied, agents' plans are first formally verified. They are then reverified after every adaptation. If reverification concludes that constraints are violated, the plans are repaired. The main objective of this paper is to improve the efficiency of reverification after learning, so that agents have a sufficiently rapid response time. We present two solutions: ...

  19. Tissue tracking in thermo-physiological imagery through spatio-temporal smoothing.

    Science.gov (United States)

    Zhou, Yan; Tsiamyrtzis, Panagiotis; Pavlidis, Ioannis T

    2009-01-01

    Accurate tracking of facial tissue in thermal infrared imaging is challenging because it is affected not only by positional but also physiological (functional) changes. This article presents a particle filter tracker driven by a probabilistic template function with both spatial and temporal smoothing components, which is capable of adapting to abrupt positional and physiological changes. The method was tested on tracking facial regions of subjects under varying physiological and environmental conditions in 12 thermal clips. It demonstrated robustness and accuracy, outperforming other strategies. This new method promises improved performance in a host of biomedical applications that involve physiological measurements on the face, like unobtrusive sleep studies. PMID:20426220

  20. Temporal ecology in the Anthropocene.

    Science.gov (United States)

    Wolkovich, E M; Cook, B I; McLauchlan, K K; Davies, T J

    2014-11-01

    Two fundamental axes - space and time - shape ecological systems. Over the last 30 years spatial ecology has developed as an integrative, multidisciplinary science that has improved our understanding of the ecological consequences of habitat fragmentation and loss. We argue that accelerating climate change - the effective manipulation of time by humans - has generated a current need to build an equivalent framework for temporal ecology. Climate change has at once pressed ecologists to understand and predict ecological dynamics in non-stationary environments, while also challenged fundamental assumptions of many concepts, models and approaches. However, similarities between space and time, especially related issues of scaling, provide an outline for improving ecological models and forecasting of temporal dynamics, while the unique attributes of time, particularly its emphasis on events and its singular direction, highlight where new approaches are needed. We emphasise how a renewed, interdisciplinary focus on time would coalesce related concepts, help develop new theories and methods and guide further data collection. The next challenge will be to unite predictive frameworks from spatial and temporal ecology to build robust forecasts of when and where environmental change will pose the largest threats to species and ecosystems, as well as identifying the best opportunities for conservation.

  1. Chondroblastoma of temporal bone

    Energy Technology Data Exchange (ETDEWEB)

    Tanohta, K.; Noda, M.; Katoh, H.; Okazaki, A.; Sugiyama, S.; Maehara, T.; Onishi, S.; Tanida, T.

    1986-07-01

    The case of a 55-year-old female with chondroblastoma arising from the left temporal bone is presented. Although 10 cases of temporal chondroblastoma have been reported, this is the first in which plain radiography, pluridirectional tomography, computed tomography (CT) and angiography were performed. We discuss the clinical and radiological aspects of this rare tumor.

  2. Incidental learning of temporal structures conforming to a metrical framework.

    Science.gov (United States)

    Brandon, Melissa; Terry, Josephine; Stevens, Catherine J; Tillmann, Barbara

    2012-01-01

    Implicit learning of sequential structures has been investigated mostly for visual, spatial, or motor learning, but rarely for temporal structure learning. The few experiments investigating temporal structure learning have concluded that temporal structures can be learned only when coupled with another structural dimension, such as musical pitch or spatial location. In these studies, the temporal structures were without metrical organization and were dependent upon participants' response times (Response-to-Stimulus Intervals). In our study, two experiments investigated temporal structure learning based on Inter-Onset-Intervals in the presence of an uncorrelated second dimension (ordinal structure) with metrically organized temporal structures. Our task was an adaptation of the classical Serial Reaction Time paradigm, using an implicit task in the auditory domain (syllable identification). Reaction times (RT) revealed that participants learned the temporal structures over the exposure blocks (decrease in RT) without a correlated ordinal dimension. The introduction of a test block with a novel temporal structure slowed RT and exemplified the typical implicit learning profile. Post-test results suggested that participants did not have explicit knowledge of the metrical temporal structures. These findings provide the first evidence of the learning of temporal structure with an uncorrelated ordinal structure, and set a foundation for further investigation of temporal cognition.

  3. Using Uncertain Climate and Development Information in Health Adaptation Planning.

    Science.gov (United States)

    Ebi, Kristie L; Hess, Jeremy J; Isaksen, Tania Busch

    2016-03-01

    To aid health adaptation decision-making, there are increasing efforts to provide climate projections at finer temporal and spatial scales. Relying solely on projected climate changes for longer-term decisions makes the implicit assumption that sources of vulnerability other than climate change will remain the same, which is not very probable. Over longer time horizons, this approach likely over estimates the extent to which climate change could alter the magnitude and pattern of health outcomes, introducing systematic bias into health management decisions. To balance this potential bias, decision-makers also need projections of other drivers of health outcomes that are, like climate change, recognized determinants of some disease burdens. Incorporating projections via an iterative process that allows for regular updates based on new knowledge and experience has the potential to improve the utility of fine-scale climate projections in health system adaptation to climate change.

  4. The Voronoi spatio-temporal data structure

    Science.gov (United States)

    Mioc, Darka

    2002-04-01

    Current GIS models cannot integrate the temporal dimension of spatial data easily. Indeed, current GISs do not support incremental (local) addition and deletion of spatial objects, and they can not support the temporal evolution of spatial data. Spatio-temporal facilities would be very useful in many GIS applications: harvesting and forest planning, cadastre, urban and regional planning, and emergency planning. The spatio-temporal model that can overcome these problems is based on a topological model---the Voronoi data structure. Voronoi diagrams are irregular tessellations of space, that adapt to spatial objects and therefore they are a synthesis of raster and vector spatial data models. The main advantage of the Voronoi data structure is its local and sequential map updates, which allows us to automatically record each event and performed map updates within the system. These map updates are executed through map construction commands that are composed of atomic actions (geometric algorithms for addition, deletion, and motion of spatial objects) on the dynamic Voronoi data structure. The formalization of map commands led to the development of a spatial language comprising a set of atomic operations or constructs on spatial primitives (points and lines), powerful enough to define the complex operations. This resulted in a new formal model for spatio-temporal change representation, where each update is uniquely characterized by the numbers of newly created and inactivated Voronoi regions. This is used for the extension of the model towards the hierarchical Voronoi data structure. In this model, spatio-temporal changes induced by map updates are preserved in a hierarchical data structure that combines events and corresponding changes in topology. This hierarchical Voronoi data structure has an implicit time ordering of events visible through changes in topology, and it is equivalent to an event structure that can support temporal data without precise temporal

  5. Attribute Exploration of Discrete Temporal Transitions

    CERN Document Server

    Wollbold, Johannes

    2007-01-01

    Discrete temporal transitions occur in a variety of domains, but this work is mainly motivated by applications in molecular biology: explaining and analyzing observed transcriptome and proteome time series by literature and database knowledge. The starting point of a formal concept analysis model is presented. The objects of a formal context are states of the interesting entities, and the attributes are the variable properties defining the current state (e.g. observed presence or absence of proteins). Temporal transitions assign a relation to the objects, defined by deterministic or non-deterministic transition rules between sets of pre- and postconditions. This relation can be generalized to its transitive closure, i.e. states are related if one results from the other by a transition sequence of arbitrary length. The focus of the work is the adaptation of the attribute exploration algorithm to such a relational context, so that questions concerning temporal dependencies can be asked during the exploration pr...

  6. 心理干预提高独生子女士兵适应能力的研究%A Study on Psychological Intervention to Improve the Adaptability of the Only Son Recruits

    Institute of Scientific and Technical Information of China (English)

    李权超; 蓝新友; 何英强; 蒋忠军; 谭终意; 李兴国

    2002-01-01

    Objective: To study the effects of psychological intervention on the adaptability of the only son recruits. Methods: Mental status of the only son recruits and non-only son recruits were assessed using Symptom Checklist-90, Social Support Questionnaire and Simplified Coping Style Questionnaire before and after psychological intervention. Results: The only son recruits scored significantly higher on depression, anxiety, and interpersonal sensitivity prior to psychological intervention, when compared to the non-only son recruits (P<0.05 or 0.01). The scores of negative emotion decreased and the scores of positive coping style increased significantly in the only son recruits after psychological intervention (P<0.05 or0.01).Conclusion: Psychological intervention could improve the psychological status and adaptability of the only son recruits.

  7. Intestinal mucosal atrophy and adaptation

    Institute of Scientific and Technical Information of China (English)

    Darcy Shaw; Kartik Gohil; Marc D Basson

    2012-01-01

    Mucosal adaptation is an essential process in gut homeostasis.The intestinal mucosa adapts to a range of pathological conditions including starvation,short-gut syndrome,obesity,and bariatric surgery.Broadly,these adaptive functions can be grouped into proliferation and differentiation.These are influenced by diverse interactions with hormonal,immune,dietary,nervous,and mechanical stimuli.It seems likely that clinical outcomes can be improved by manipulating the physiology of adaptation.This review will summarize current understanding of the basic science surrounding adaptation,delineate the wide range of potential targets for therapeutic intervention,and discuss how these might be incorporated into an overall treatment plan.Deeper insight into the physiologic basis of adaptation will identify further targets for intervention to improve clinical outcomes.

  8. Neuromuscular adaptations to long-term progressive resistance training translates to improved functional capacity for people with multiple sclerosis and is maintained at follow-up

    DEFF Research Database (Denmark)

    Kjølhede, Tue; Vissing, Kristian; de Place, Line;

    2015-01-01

    BACKGROUND: Progressive resistance training (PRT) is acknowledged to effectively improve muscle strength for people with multiple sclerosis (PwMS), but diverging results exist regarding whether such improvements translates to improved functional capacity, possibly relating to insufficient duration......: This study was a randomised controlled trial, with a training group and a waitlist group undergoing supervised PRT for 24 weeks initially or after 24 weeks of habitual lifestyle, respectively. Functional capacity, isometric muscle strength of knee extensors and flexors, neural drive and thigh muscle cross......-sectional area was measured at baseline, after 24 and 48 weeks. RESULTS: The training group significantly improved neuromuscular function of the knee extensors and flexors, which translated to improvements in functional capacity. Furthermore, the improved functional capacity was maintained after 24 weeks of self...

  9. AdapterRemoval v2

    DEFF Research Database (Denmark)

    Schubert, Mikkel; Lindgreen, Stinus; Orlando, Ludovic

    2016-01-01

    process the growing amount of data generated per sequencing run. FINDINGS: We introduce AdapterRemoval v2, a major revision of AdapterRemoval v1, which introduces (i) striking improvements in throughput, through the use of single instruction, multiple data (SIMD; SSE1 and SSE2) instructions and multi......-threading support, (ii) the ability to handle datasets containing reads or read-pairs with different adapters or adapter pairs, (iii) simultaneous demultiplexing and adapter trimming, (iv) the ability to reconstruct adapter sequences from paired-end reads for poorly documented data sets, and (v) native gzip and...... bzip2 support. CONCLUSIONS: We show that AdapterRemoval v2 compares favorably with existing tools, while offering superior throughput to most alternatives examined here, both for single and multi-threaded operations....

  10. Is adaptation. Truly an adaptation? Is adaptation. Truly an adaptation?

    Directory of Open Access Journals (Sweden)

    Thais Flores Nogueira Diniz

    2008-04-01

    Full Text Available The article begins by historicizing film adaptation from the arrival of cinema, pointing out the many theoretical approaches under which the process has been seen: from the concept of “the same story told in a different medium” to a comprehensible definition such as “the process through which works can be transformed, forming an intersection of textual surfaces, quotations, conflations and inversions of other texts”. To illustrate this new concept, the article discusses Spike Jonze’s film Adaptation. according to James Naremore’s proposal which considers the study of adaptation as part of a general theory of repetition, joined with the study of recycling, remaking, and every form of retelling. The film deals with the attempt by the scriptwriter Charles Kaufman, cast by Nicholas Cage, to adapt/translate a non-fictional book to the cinema, but ends up with a kind of film which is by no means what it intended to be: a film of action in the model of Hollywood productions. During the process of creation, Charles and his twin brother, Donald, undergo a series of adventures involving some real persons from the world of film, the author and the protagonist of the book, all of them turning into fictional characters in the film. In the film, adaptation then signifies something different from itstraditional meaning. The article begins by historicizing film adaptation from the arrival of cinema, pointing out the many theoretical approaches under which the process has been seen: from the concept of “the same story told in a different medium” to a comprehensible definition such as “the process through which works can be transformed, forming an intersection of textual surfaces, quotations, conflations and inversions of other texts”. To illustrate this new concept, the article discusses Spike Jonze’s film Adaptation. according to James Naremore’s proposal which considers the study of adaptation as part of a general theory of repetition

  11. Improving Adaptive Learning Rate of BP Neural Network for the Modelling of 3D Woven Composites Using the Golden Section Law

    Institute of Scientific and Technical Information of China (English)

    易洪雷; 丁辛

    2001-01-01

    Focused on various BP algorithms with variable learning rate based on network system error gradient, a modified learning strategy for training non-linear network models is developed with both the incremental and the decremental factors of network learning rate being adjusted adaptively and dynamically. The golden section law is put forward to build a relationship between the network training parameters, and a series of data from an existing model is used to train and test the network parameters. By means of the evaluation of network performance in respect to convergent speed and predicting precision, the effectiveness of the proposed learning strategy can be illustrated.

  12. An ‘innovation-cycle framework’ of integrated agricultural knowledge system and innovation for improving farmers’climate change adaptation and risk mitigation capacities

    DEFF Research Database (Denmark)

    Rahman, Md Zillur

    2015-01-01

    The main objective of this paper is to present a new ‘innovation-cycle’ integrated conceptual framework of ‘TVET-adaptive AKSI’ (TVET: Technical and Vocational Education and Training; AKSI: Agricultural Knowledge System and Innovation). Thus the aim here is to discuss from existing body....... Thus the aim of this paper is to explore existing literature to draw an understanding by developing a ‘conceptual framework’ about the urgent need of future ‘Game Changer’ strategy (e.g. Next Frontier of Green Innovation) for the safety and security of rapidly growing population by tackling...

  13. Adaptive Mesh Refinement in CTH

    International Nuclear Information System (INIS)

    This paper reports progress on implementing a new capability of adaptive mesh refinement into the Eulerian multimaterial shock- physics code CTH. The adaptivity is block-based with refinement and unrefinement occurring in an isotropic 2:1 manner. The code is designed to run on serial, multiprocessor and massive parallel platforms. An approximate factor of three in memory and performance improvements over comparable resolution non-adaptive calculations has-been demonstrated for a number of problems

  14. Staff Adaptation in Selected Company

    OpenAIRE

    Štolcová, Jana

    2011-01-01

    The work focuses on personnel actions of employee adaptation as, nowadays, it is very important to maintain a good and skilled staff. The main aim of this work is to analyze and evaluate the process of adaptation of new employees at the headquarters of the BILLA, Ltd., which operates more than 200 supermarkets around the Czech Republic,. Another task is to propose partial measures which would improve the process of adaptation in the society. The literature review discusses the importance of ...

  15. PCMAT, an adaptive learning platform

    OpenAIRE

    Couto, Paulo; Fernandes, Marta; Martins, Constantino; Faria, Luiz

    2013-01-01

    This paper is about PCMAT, an adaptive learning platform for Mathematics in Basic Education schools. Based on a constructivist approach, PCMAT aims at verifying how techniques from adaptive hypermedia systems can improve e-learning based systems. To achieve this goal, PCMAT includes a Pedagogical Model that contains a set of adaptation rules that influence the student-platform interaction. PCMAT was subject to a preliminary testing with students aged between 12 and 14 years old on th...

  16. Processing of Uncertainty Temporal Relations

    Institute of Scientific and Technical Information of China (English)

    钟绍春; 刘大有

    1996-01-01

    Akind of classiication on temporal relations of propositions is presented.By introducing temporal approaching relation,a new temporal logic based on time-point and time-interval is proposed,which can describe uncertain temporal relations.Finally,some properties of temporal proposition under uncertain relations are proposed.

  17. [Duration and temporality].

    Science.gov (United States)

    Fouks, L; Guibert, S; Cardon; Montot

    1990-01-01

    The notion of temporality in living is in perpetual motion between passive temporality and creative conscience. Human existence is not purely immanent, a flow of transcedence continually runs through it. Melancholia is a lose of creativity accompanied by a feeling that time as lived has stopped, time being lived as a new mode of space. Maniac temporality is an improductive and unsociable furious flight toward. The melancholic feeling out of time is crushed by the problematic of alterity, sin and eternity. The maniac lives an imaginary and deceptive problematic. The ambivalent ideal of the schizophrenic is both a return to biological life as well as a fascination by formal thought.

  18. Optimizing Temporal Queries

    DEFF Research Database (Denmark)

    Toman, David; Bowman, Ivan Thomas

    2003-01-01

    Recent research in the area of temporal databases has proposed a number of query languages that vary in their expressive power and the semantics they provide to users. These query languages represent a spectrum of solutions to the tension between clean semantics and efficient evaluation. Often, t...... translated SQL queries by taking into account the properties of the encoding used for temporal attributes. For concreteness, this translation technique is presented in the context of SQL/TP; however, these techniques are also applicable to other temporal query languages....

  19. Improved Real-time Implementation of Adaptive Gassian Mixture Model-based Object Detection Algorithm for Fixed-point DSP Processors

    Institute of Scientific and Technical Information of China (English)

    Byung-eun LEE; Thanh-binh NGUYEN; Sun-tae CHUNG

    2010-01-01

    Foreground moving object detection is an important pocess in various computer vision applicatipons such as intelligent visual sur-veillance,HCI,object-based video compression,etc.One of the most successful moving object detection algorithms is based on Adaptive Gaussian Mixture Model (AGMM).Although AGMM-based object detection shows very good performance with respect to object detection accuracy,AGMM is very complex model requiring lots of floating-point arithmetic so that it should pay for expensive computational cost.Thus,direa implementation of the AGMM-based object detec-tion for embedded DSPs without floating-point arithmetic HW support cannot satisfy the real-time processing requirement.This paper pre-sents a navel real-time implementation of adaptive Gaussian mixture model-based moving object detection algorithm for fixed-point DSPs.In the proposed implementation,in addition to changes of data types into fixed- point ones,magnification of the Gaussian distribution tech nique is introduced so that the integer and fixed-point arithmetic can be easily and consistently utilized instead of real number and floating-point arithmetic in processing of AGMM algorithm.Experimental re-sults shows that the proposed implementation have a high potential in real-time applications.

  20. An improved approach based on fuzzy clustering and Back-Propagation Neural Networks with adaptive learning rate for sales forecasting: Case study of PCB industry

    Directory of Open Access Journals (Sweden)

    Attariuas Hicham

    2012-05-01

    Full Text Available This paper describes new hybrid sales forecasting system based on fuzzy clustering and Back-propagation (BP Neural Networks with adaptive learning rate (FCBPN.The proposed approach is composed of three stages: (1 Winters Exponential Smoothing method will be utilized to take the trend effect into consideration; (2 utilizing Fuzzy C-Means clustering method (Used in an clusters memberships fuzzy system (CMFS, the clusters membership levels of each normalized data records will be extracted; (3 Each cluster will be fed into parallel BP networks with a learning rate adapted as the level of cluster membership of training data records. Compared to many researches which use Hard clustering, we employ fuzzy clustering which permits each data record to belong to each cluster to a certain degree, which allows the clusters to be larger which consequently increases the accuracy of the proposed forecasting system . Printed Circuit Board (PCB will be used as a case study to evaluate the precision of our proposed architecture. Experimental results show that the proposed model outperforms the previous and traditional approaches. Therefore, it is a very promising solution for industrial forecasting.

  1. A Two-Stage Approach for Improving the Convergence of Least-Mean-Square Adaptive Decision-Feedback Equalizers in the Presence of Severe Narrowband Interference

    Directory of Open Access Journals (Sweden)

    A. A. (Louis Beex

    2008-02-01

    Full Text Available It has previously been shown that a least-mean-square (LMS decision-feedback filter can mitigate the effect of narrowband interference (L.-M. Li and L. Milstein, 1983. An adaptive implementation of the filter was shown to converge relatively quickly for mild interference. It is shown here, however, that in the case of severe narrowband interference, the LMS decision-feedback equalizer (DFE requires a very large number of training symbols for convergence, making it unsuitable for some types of communication systems. This paper investigates the introduction of an LMS prediction-error filter (PEF as a prefilter to the equalizer and demonstrates that it reduces the convergence time of the two-stage system by as much as two orders of magnitude. It is also shown that the steady-state bit-error rate (BER performance of the proposed system is still approximately equal to that attained in steady-state by the LMS DFE-only. Finally, it is shown that the two-stage system can be implemented without the use of training symbols. This two-stage structure lowers the complexity of the overall system by reducing the number of filter taps that need to be adapted, while incurring a slight loss in the steady-state BER.

  2. 一种基于自适应能力改进的AFSA算法研究%Research about an Improved AFSA Algorithm Based on Self-Adapt Ability

    Institute of Scientific and Technical Information of China (English)

    王虎强; 李东

    2015-01-01

    文章在分析基本人工鱼群算法(AFSA)的基础上,提出了一种基于自适应能力的改进人工鱼群算法,在不明显增加算法计算复杂性的前提下,引入自适应移动和visual、step参数自适应调整策略,这对于克服算法优化后期收敛速度慢,感知和移动距离随机性大、寻优精度低等缺点具有显著效果.仿真测试表明,改进后的人工鱼群算法在很大程度上摆脱了局部极值吸引的能力,寻优精度明显提高.%The paper puts forward an improved AFSA algorithm based on self-adapt ability after analyzing the original artificial fish-swarm algorithm, which not only draws into the self-adapt movement but also the self-adapt adjustment of visual and step with no extra calculate complexity, this will be helpful to overcome the slow convergence in the afterlife of its lifecycle, random perception and movement as well as the low precision of searching. The results of simulation show that the improved AFSA al-gorithm gets rid of the attraction ability of local peak, the precision of searching is improved obviously.

  3. Research about an Improved AFSA Algorithm Based on Self-Adapt Ability%一种基于自适应能力改进的AFSA算法研究

    Institute of Scientific and Technical Information of China (English)

    王虎强; 李东

    2015-01-01

    The paper puts forward an improved AFSA algorithm based on self-adapt ability after analyzing the original artificial fish-swarm algorithm, which not only draws into the self-adapt movement but also the self-adapt adjustment of visual and step with no extra calculate complexity, this will be helpful to overcome the slow convergence in the afterlife of its lifecycle, random perception and movement as well as the low precision of searching. The results of simulation show that the improved AFSA al-gorithm gets rid of the attraction ability of local peak, the precision of searching is improved obviously.%文章在分析基本人工鱼群算法(AFSA)的基础上,提出了一种基于自适应能力的改进人工鱼群算法,在不明显增加算法计算复杂性的前提下,引入自适应移动和visual、step参数自适应调整策略,这对于克服算法优化后期收敛速度慢,感知和移动距离随机性大、寻优精度低等缺点具有显著效果.仿真测试表明,改进后的人工鱼群算法在很大程度上摆脱了局部极值吸引的能力,寻优精度明显提高.

  4. Seleção de progênies de erva-mate (Ilex paraguariensis St. Hill. para a produtividade, estabilidade e adaptabilidade temporal de massa foliar Selection of Erva-mate Progenies for Leaf Weight Productivity, Temporal Stability and Adaptability

    Directory of Open Access Journals (Sweden)

    José Alfredo Sturion

    2011-03-01

    Full Text Available O presente trabalho teve por objetivos selecionar progênies de erva-mate (Ilex paraguariensis St. Hil.  em Ivaí - PR, simultaneamente para estabilidade, adaptabilidade e produtividade de massa foliar,  colhidas em três safras, com base na média harmônica a performance relativa dos valores genéticos (MHPRVG, adicionalmente, comparar os resultados  com aqueles obtidos pelos métodos de Annicchiarico e  de Lin & Binns. O material genético consistiu de 25  progênies de meios-irmãos plantadas no delineamento  de blocos ao acaso, com dez repetições  e parcelas lineares de seis plantas no espaçamento de  3m x 2m. O peso de folhas foi avaliado, por árvore,  aos dois, quatro e seis anos após o plantio. Houve  uma alteração no ordenamento das progênies para a produção de massa foliar ao longo das safras. Os  métodos de Annicchiarico, Lin & Binns e MHPRVG  selecionaram, praticamente, as mesmas progênies para os três atributos considerados. Contudo, o método  HPRVG apresenta a vantagem de fornecer  resultados na própria escala e medição do caráter, os quais podem ser interpretados diretamente como  valores genéticos.
    This paper aimed to select progenies of “erva-mate” (Ilex paraguariensis St. HiI. in Ivai - PR based on leaf weight productivity, stability and adaptability across three harvests. This can be achieved by the method MHPRVG (harmonic average of relative performance of genetic values which is comparable with the methods by Annichiaricco and Lin & Binns. The genetic material was constituted by 25 half sib progenies evaluated in a complete block design with ten replicates and six plants per plot, in a 3 x 2 meters spacing. Leaf weight per tree  was evaluated at ages two, four and six years  after planting. There were some changes in progenies  ranking across harvests. The methods MHPRVG, Annichiaricco and Lin & Binns led to selection of the  same progenies, considering the three

  5. Tiled Polymorphic Temporal Media

    OpenAIRE

    Hudak, Paul; Janin, David

    2014-01-01

    International audience Tiled Polymorphic Temporal Media (Tiled PTM) is an algebraic approach to specifying the composition of multimedia values having an inherent temporal quality --- for example sound clips, musical scores, computer animations, and video clips. Mathematically, one can think of a tiled PTM as a tiling in the one dimension of time. A tiled PTM value has two synchronization marks that specify, via an effective notion of tiled product, how the tiled PTMs are positioned in tim...

  6. SHEEP TEMPORAL BONE

    Directory of Open Access Journals (Sweden)

    Kesavan

    2016-03-01

    Full Text Available INTRODUCTION Human temporal bones are difficult to procure now a days due to various ethical issues. Sheep temporal bone is a good alternative due to morphological similarities, easy to procure and less cost. Many middle ear exercises can be done easily and handling of instruments is done in the procedures like myringoplasty, tympanoplasty, stapedotomy, facial nerve dissection and some middle ear implants. This is useful for resident training programme.

  7. Adaptive codebook selection schemes for image classification in correlated channels

    Science.gov (United States)

    Hu, Chia Chang; Liu, Xiang Lian; Liu, Kuan-Fu

    2015-09-01

    The multiple-input multiple-output (MIMO) system with the use of transmit and receive antenna arrays achieves diversity and array gains via transmit beamforming. Due to the absence of full channel state information (CSI) at the transmitter, the transmit beamforming vector can be quantized at the receiver and sent back to the transmitter by a low-rate feedback channel, called limited feedback beamforming. One of the key roles of Vector Quantization (VQ) is how to generate a good codebook such that the distortion between the original image and the reconstructed image is the minimized. In this paper, a novel adaptive codebook selection scheme for image classification is proposed with taking both spatial and temporal correlation inherent in the channel into consideration. The new codebook selection algorithm is developed to select two codebooks from the discrete Fourier transform (DFT) codebook, the generalized Lloyd algorithm (GLA) codebook and the Grassmannian codebook to be combined and used as candidates of the original image and the reconstructed image for image transmission. The channel is estimated and divided into four regions based on the spatial and temporal correlation of the channel and an appropriate codebook is assigned to each region. The proposed method can efficiently reduce the required information of feedback under the spatially and temporally correlated channels, where each region is adaptively. Simulation results show that in the case of temporally and spatially correlated channels, the bit-error-rate (BER) performance can be improved substantially by the proposed algorithm compared to the one with only single codebook.

  8. An improved adaptive artificial potential field method for the path planning of multi-robot%一种改进的多机器人路径规划自适应人工势场法

    Institute of Scientific and Technical Information of China (English)

    高瑜; 过金超; 崔光照

    2013-01-01

    Based on the study of the traditional multi-robot path planning,an improved adaptive artificial potential field method was proposed.In this method,the local minimum problem of the traditional artificial potential field could be solved by setting the virtual target point for mobile robot to escape local minimum. At the same time,according to the task and speed of the robot,it used the adaptive priority strategy to real-ize the adaptive obstacle avoidance of the robot.The results of the simulation proved the effectiveness and feasibility of this method.%在研究多机器人路径规划传统方法的基础上,提出了一种改进的自适应人工势场法。该方法通过设置虚拟目标点来解决传统人工势场法易陷入局部极小点的问题,同时根据各个机器人所承担的任务和速度,采用自适应优先权策略来实现机器人之间的自适应避障。仿真实验验证了该方法的有效性和可行性。

  9. An Improved Adaptive Multi-way Principal Component Analysis for Monitoring Streptomycin Fermentation Process%自适应MPCA方法在链霉素过程监控中的应用

    Institute of Scientific and Technical Information of China (English)

    何宁; 王树青

    2004-01-01

    Multi-way principal component analysis (MPCA) had been successfully applied to monitoring the batch and semi-batch process in most chemical industry. An improved MPCA approach, step-by-step adaptive MPCA (SAMPCA), using the process variable trajectories to monitoring the batch process is presented in this paper. It does not need to estimate or fill in the unknown part of the process variable trajectory deviation from the current time until the end. The approach is based on a MPCA method that processes the data in a sequential and adaptive manner. The adaptive rate is easily controlled through a forgetting factor that controls the weight of past data in a summation. This algorithm is used to evaluate the industrial streptomycin fermentation process data and is compared with the traditional MPCA. The results show that the method is more advantageous than MPCA,especially when monitoring multi-stage batch process where the latent vector structure can change at several points during the batch.

  10. Adaptive test

    DEFF Research Database (Denmark)

    Kjeldsen, Lars Peter; Eriksen, Mette Rose

    2010-01-01

    Artikelen er en evaluering af de adaptive tests, som blev indført i folkeskolen. Artiklen sætter særligt fokus på evaluering i folkeskolen, herunder bidrager den med vejledning til evaluering, evalueringsværktøjer og fagspecifkt evalueringsmateriale.......Artikelen er en evaluering af de adaptive tests, som blev indført i folkeskolen. Artiklen sætter særligt fokus på evaluering i folkeskolen, herunder bidrager den med vejledning til evaluering, evalueringsværktøjer og fagspecifkt evalueringsmateriale....

  11. Strategic Adaptation

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    2015-01-01

    This article provides an overview of theoretical contributions that have influenced the discourse around strategic adaptation including contingency perspectives, strategic fit reasoning, decision structure, information processing, corporate entrepreneurship, and strategy process. The related...... concepts of strategic renewal, dynamic managerial capabilities, dynamic capabilities, and strategic response capabilities are discussed and contextualized against strategic responsiveness. The insights derived from this article are used to outline the contours of a dynamic process of strategic adaptation....... This model incorporates elements of central strategizing, autonomous entrepreneurial behavior, interactive information processing, and open communication systems that enhance the organization's ability to observe exogenous changes and respond effectively to them....

  12. Adaptation investments and homeownership

    DEFF Research Database (Denmark)

    Hansen, Jørgen Drud; Skak, Morten

    2008-01-01

    This article develops a model where ownership improves the efficiency of the housing market as it enhances the utility of housing consumption for some consumers. The model is based on an extended Hotelling-Lancaster utility approach in which the ideal variant of housing is obtainable only...... by adapting the home through a supplementary investment. Ownership offers low costs of adaptation, but has high contract costs compared with renting. Consumers simultaneously choose housing demand and tenure, and because of the different cost structure only consumers with strong preferences for individual...

  13. Adaptive management: Chapter 1

    Science.gov (United States)

    Allen, Craig R.; Garmestani, Ahjond S.; Allen, Craig R.; Garmestani, Ahjond S.

    2015-01-01

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive management has explicit structure, including a careful elucidation of goals, identification of alternative management objectives and hypotheses of causation, and procedures for the collection of data followed by evaluation and reiteration. The process is iterative, and serves to reduce uncertainty, build knowledge and improve management over time in a goal-oriented and structured process.

  14. Adaptive Metric Kernel Regression

    DEFF Research Database (Denmark)

    Goutte, Cyril; Larsen, Jan

    1998-01-01

    Kernel smoothing is a widely used nonparametric pattern recognition technique. By nature, it suffers from the curse of dimensionality and is usually difficult to apply to high input dimensions. In this paper, we propose an algorithm that adapts the input metric used in multivariate regression by...... minimising a cross-validation estimate of the generalisation error. This allows one to automatically adjust the importance of different dimensions. The improvement in terms of modelling performance is illustrated on a variable selection task where the adaptive metric kernel clearly outperforms the standard...

  15. Adaptive metric kernel regression

    DEFF Research Database (Denmark)

    Goutte, Cyril; Larsen, Jan

    2000-01-01

    Kernel smoothing is a widely used non-parametric pattern recognition technique. By nature, it suffers from the curse of dimensionality and is usually difficult to apply to high input dimensions. In this contribution, we propose an algorithm that adapts the input metric used in multivariate...... regression by minimising a cross-validation estimate of the generalisation error. This allows to automatically adjust the importance of different dimensions. The improvement in terms of modelling performance is illustrated on a variable selection task where the adaptive metric kernel clearly outperforms the...

  16. Temporal sparsity exploiting nonlocal regularization for 4D computed tomography reconstruction.

    Science.gov (United States)

    Kazantsev, Daniil; Guo, Enyu; Kaestner, Anders; Lionheart, William R B; Bent, Julian; Withers, Philip J; Lee, Peter D

    2016-01-01

    X-ray imaging applications in medical and material sciences are frequently limited by the number of tomographic projections collected. The inversion of the limited projection data is an ill-posed problem and needs regularization. Traditional spatial regularization is not well adapted to the dynamic nature of time-lapse tomography since it discards the redundancy of the temporal information. In this paper, we propose a novel iterative reconstruction algorithm with a nonlocal regularization term to account for time-evolving datasets. The aim of the proposed nonlocal penalty is to collect the maximum relevant information in the spatial and temporal domains. With the proposed sparsity seeking approach in the temporal space, the computational complexity of the classical nonlocal regularizer is substantially reduced (at least by one order of magnitude). The presented reconstruction method can be directly applied to various big data 4D (x, y, z+time) tomographic experiments in many fields. We apply the proposed technique to modelled data and to real dynamic X-ray microtomography (XMT) data of high resolution. Compared to the classical spatio-temporal nonlocal regularization approach, the proposed method delivers reconstructed images of improved resolution and higher contrast while remaining significantly less computationally demanding. PMID:27002902

  17. Temporal sparsity exploiting nonlocal regularization for 4D computed tomography reconstruction.

    Science.gov (United States)

    Kazantsev, Daniil; Guo, Enyu; Kaestner, Anders; Lionheart, William R B; Bent, Julian; Withers, Philip J; Lee, Peter D

    2016-01-01

    X-ray imaging applications in medical and material sciences are frequently limited by the number of tomographic projections collected. The inversion of the limited projection data is an ill-posed problem and needs regularization. Traditional spatial regularization is not well adapted to the dynamic nature of time-lapse tomography since it discards the redundancy of the temporal information. In this paper, we propose a novel iterative reconstruction algorithm with a nonlocal regularization term to account for time-evolving datasets. The aim of the proposed nonlocal penalty is to collect the maximum relevant information in the spatial and temporal domains. With the proposed sparsity seeking approach in the temporal space, the computational complexity of the classical nonlocal regularizer is substantially reduced (at least by one order of magnitude). The presented reconstruction method can be directly applied to various big data 4D (x, y, z+time) tomographic experiments in many fields. We apply the proposed technique to modelled data and to real dynamic X-ray microtomography (XMT) data of high resolution. Compared to the classical spatio-temporal nonlocal regularization approach, the proposed method delivers reconstructed images of improved resolution and higher contrast while remaining significantly less computationally demanding.

  18. Sleep apnea syndrome: central sleep apnea and pulmonary hypertension worsened during treatment with auto-CPAP, but improved by adaptive servo-ventilation.

    Science.gov (United States)

    Ono, Hiroshi; Fujimoto, Hiroyuki; Kobayashi, Yoshinori; Kudoh, Shoji; Gemma, Akihiko

    2010-01-01

    In this 71-year-old man diagnosed as obstructive sleep apnea syndrome initially, the apnea-hypopnea index in polysomnography was 31.3/hour. He started auto-adjusted continuous positive airway pressure (auto-CPAP) treatment in July 2005 but developed congestive heart failure in December 2007. Pulmonary arterial pressure (PAP), estimated by echocardiography, was 71 mmHg. In January 2008, during simplified sleep examination with a breath-movement sensor under auto-CPAP, many central-type apneas were recognized. After replacing auto-CPAP with adaptive servo-ventilation (ASV), the apnea-hypopnea index was 5.3/hour and PAP became 36 mmHg after 3 months. It was thought that the increase of PAP was due to long-term inadequate use of auto-CPAP.

  19. Reduction of ethanol yield and improvement of glycerol formation by adaptive evolution of the wine yeast Saccharomyces cerevisiae under hyperosmotic conditions.

    Science.gov (United States)

    Tilloy, Valentin; Ortiz-Julien, Anne; Dequin, Sylvie

    2014-04-01

    There is a strong demand from the wine industry for methodologies to reduce the alcohol content of wine without compromising wine's sensory characteristics. We assessed the potential of adaptive laboratory evolution strategies under hyperosmotic stress for generation of Saccharomyces cerevisiae wine yeast strains with enhanced glycerol and reduced ethanol yields. Experimental evolution on KCl resulted, after 200 generations, in strains that had higher glycerol and lower ethanol production than the ancestral strain. This major metabolic shift was accompanied by reduced fermentative capacities, suggesting a trade-off between high glycerol production and fermentation rate. Several evolved strains retaining good fermentation performance were selected. These strains produced more succinate and 2,3-butanediol than the ancestral strain and did not accumulate undesirable organoleptic compounds, such as acetate, acetaldehyde, or acetoin. They survived better under osmotic stress and glucose starvation conditions than the ancestral strain, suggesting that the forces that drove the redirection of carbon fluxes involved a combination of osmotic and salt stresses and carbon limitation. To further decrease the ethanol yield, a breeding strategy was used, generating intrastrain hybrids that produced more glycerol than the evolved strain. Pilot-scale fermentation on Syrah using evolved and hybrid strains produced wine with 0.6% (vol/vol) and 1.3% (vol/vol) less ethanol, more glycerol and 2,3-butanediol, and less acetate than the ancestral strain. This work demonstrates that the combination of adaptive evolution and breeding is a valuable alternative to rational design for remodeling the yeast metabolic network. PMID:24532067

  20. 一种改进的自适应关键帧提取方法%An Improved Algorithm of Adaptive Key Frame Extraction

    Institute of Scientific and Technical Information of China (English)

    陈青华; 程恭; 谢晓方; 唐江

    2011-01-01

    针对关键帧提取方法中关键帧数目固定,不能根据镜头自适应调整的缺点,将帧间差法与运动变化信息熵方法相结合,提出一种自适应关键帧提取方法.根据镜头的变化确定提取的关键帧数目,采用运动信息的变化熵来提取关键帧,构建关键帧提取的数学模型,并通过实验进行验证.实验结果表明:该算法明显优于等间隔关键帧提取算法,提取的关键帧能较完整地表现序列图像的运动过程,更有利于对视频内容的理解.%Based on the problem that key frame number can not adaptively adjusted according to the lens, the paper proposed an adaptively key frame extraction method based on frame difference and the motion information entropy. The method determined the number of extracted key frame according to changes of the lens and extracted key frame based on the maximal motion and changing information entropy. A mathematical model for key frame extraction was constructed. And the theory of this method was introduced in detail. Many contrasting experiment have demonstrated that this method is obviously better than the key-fame extraction by equal interval. By this method the changing process of sequence is represented perfectly. It provides better perception and understanding for the video.

  1. Recognising and Interpreting Named Temporal Expressions

    DEFF Research Database (Denmark)

    Brucato, Matteo; Derczynski, Leon; Llorens, Hectjor;

    2013-01-01

    expressions is mature in many languages. However, there is a class of expressions that are less typical, very varied, and difficult to automatically interpret. These indicate dates and times, but are harder to detect because they often do not contain time words and are not used frequently enough to appear...... in conventional temporally-annotated corpora – for example Michaelmas or Vasant Panchami. UsingWikipedia and linked data, we automatically construct a resource of English named temporal expressions, and use it to extract training examples from a large corpus. These examples are then used to train and evaluate...... a named temporal expression recogniser. We also introduce and evaluate rules for automatically interpreting these expressions, and we observe that use of the rules improves temporal annotation performance over existing corpora....

  2. Cannabinoid Receptor Activation Shifts Temporally Engendered Patterns of Dopamine Release

    OpenAIRE

    Oleson, Erik B.; Cachope, Roger; Fitoussi, Aurelie; Tsutsui, Kimberly; Wu, Sharon; Gallegos, Jacqueline A; Cheer, Joseph F.

    2014-01-01

    The ability to discern temporally pertinent environmental events is essential for the generation of adaptive behavior in conventional tasks, and our overall survival. Cannabinoids are thought to disrupt temporally controlled behaviors by interfering with dedicated brain timing networks. Cannabinoids also increase dopamine release within the mesolimbic system, a neural pathway generally implicated in timing behavior. Timing can be assessed using fixed-interval (FI) schedules, which reinforce b...

  3. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to oligomeric procyanidins (OPCs) from grape (Vitis vinifera L.) seeds and improvement of visual adaptation to the dark (ID 680) pursuant to Article 13(1) of Regulation

    DEFF Research Database (Denmark)

    Tetens, Inge

    . The claimed effect is “ocular system: OPCs play an important role in the structure and physiological functions of cornea, OPCs protect the cornea and improve visual adaptation to low luminances”. The target population is assumed to be the general population. In the context of the proposed wordings...... claims in relation to oligomeric procyanidins (OPCs) from grape (Vitis vinifera L.) seeds and improvement of visual adaptation to the dark. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA......, clarifications from Member States and the references provided, the Panel assumes that the claimed effect refers to the improvement of visual adaptation to the dark. The Panel considers that improvement of visual adaptation to the dark is a beneficial physiological effect. No references were provided from which...

  4. Virtual Temporal Bone Anatomy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Background The Visible Human Project(VHP) initiated by the U.S. National Library of Medicine has drawn much attention and interests from around the world. The Visible Chinese Human (VCH) project has started in China. The current study aims at acquiring a feasible virtual methodology for reconstructing the temporal bone of the Chinese population, which may provide an accurate 3-D model of important temporal bone structures that can be used in teaching and patient care for medical scientists and clinicians. Methods A series of sectional images of the temporal bone were generated from section slices of a female cadaver head. On each sectional image, SOIs (structures of interest) were segmented by carefully defining their contours and filling their areas with certain gray scale values. The processed volume data were then inducted into the 3D Slicer software(developed by the Surgical Planning Lab at Brigham and Women's Hospital and the MIT AI Lab) for resegmentation and generation of a set of tagged images of the SOIs. 3D surface models of SOIs were then reconstructed from these images. Results The temporal bone and structures in the temporal bone, including the tympanic cavity, mastoid cells, sigmoid sinus and internal carotid artery, were successfully reconstructed. The orientation of and spatial relationship among these structures were easily visualized in the reconstructed surface models. Conclusion The 3D Slicer software can be used for 3-dimensional visualization of anatomic structures in the temporal bone, which will greatly facilitate the advance of knowledge and techniques critical for studying and treating disorders involving the temporal bone.

  5. 一类广义隐互补问题的改进的自适应算法%An Improved Self-adaptive Projection Method for a Form of Generalized Implicit Complementarity Problem

    Institute of Scientific and Technical Information of China (English)

    郑邦贵; 张国娟; 陈玮玮

    2012-01-01

    互补问题是运筹学与计算数学的一个交叉研究领域,在力学、工程、经济、交通等许多实际部门有广泛的应用,是数学规划中的一个热门的研究课题.研究了一类广义隐互补问题,改进了变分不等式的自适应算法,并将其应用到广义隐互补问题中:建立了广义隐互补问题的改进的自适应算法,并研究了在伪单调条件下算法的收敛性和收敛速度,讨论了校正步长的选择方法及参数限制条件.%Complementarity problem is a cross research field in operations research and computational mathematics. It has extensive applications in mechanics, engineering, economics, transportation and many other practical departments. It is a very hot research topic in mathematical planning. In this paper we study a class of generalized implicit complementarity problems, give an Improved Self-adaptive Projection method for variational inequality algorithm. The Self-adaptive Projection method is used to solve implicit complementarity problems. The improved Self-adaptive Projection method is built for generalized implicit complementarity problem and porves its convergence with pseudomonotone function. Theremore, we study the step size correction and the parameters.

  6. Adaptable Embedded Systems

    CERN Document Server

    Lisbôa, Carlos; Carro, Luigi

    2013-01-01

    As embedded systems become more complex, designers face a number of challenges at different levels: they need to boost performance, while keeping energy consumption as low as possible, they need to reuse existent software code, and at the same time they need to take advantage of the extra logic available in the chip, represented by multiple processors working together.  This book describes several strategies to achieve such different and interrelated goals, by the use of adaptability. Coverage includes reconfigurable systems, dynamic optimization techniques such as binary translation and trace reuse, new memory architectures including homogeneous and heterogeneous multiprocessor systems, communication issues and NOCs, fault tolerance against fabrication defects and soft errors, and finally, how one can combine several of these techniques together to achieve higher levels of performance and adaptability.  The discussion also includes how to employ specialized software to improve this new adaptive system, and...

  7. Spatiotemporal specificity of contrast adaptation in mouse primary visual cortex

    Directory of Open Access Journals (Sweden)

    Emily Elizabeth LeDue

    2013-10-01

    Full Text Available Prolonged viewing of high contrast gratings alters perceived stimulus contrast, and produces characteristic changes in the contrast response functions of neurons in the primary visual cortex (V1. This is referred to as contrast adaptation. Although contrast adaptation has been well studied, its underlying neural mechanisms are not well understood. Therefore, we investigated contrast adaptation in mouse V1 with the goal of establishing a quantitative description of this phenomenon in a genetically manipulable animal model. One interesting aspect of contrast adaptation that has been observed both perceptually and in single unit studies is its specificity for the spatial and temporal characteristics of the stimulus. Therefore in the present work we determined if the magnitude of contrast adaptation in mouse V1 neurons was dependent on the spatial frequency and temporal frequency of the adapting grating. We used protocols that were readily comparable with previous studies in cats and primates, and also a novel contrast ramp stimulus that characterized the spatial and temporal specificity of contrast adaptation simultaneously. Similar to previous work in higher mammals, we found that contrast adaptation was strongest when the spatial frequency and temporal frequency of the adapting grating matched the test stimulus. This suggests similar mechanisms underlying contrast adaptation across animal models and indicates that the rapidly advancing genetic tools available in mice could be used to provide insights into this phenomenon.

  8. An Adaptive Dynamic Pointing Assistance Program to Help People with Multiple Disabilities Improve Their Computer Pointing Efficiency with Hand Swing through a Standard Mouse

    Science.gov (United States)

    Shih, Ching-Hsiang; Shih, Ching-Tien; Wu, Hsiao-Ling

    2010-01-01

    The latest research adopted software technology to redesign the mouse driver, and turned a mouse into a useful pointing assistive device for people with multiple disabilities who cannot easily or possibly use a standard mouse, to improve their pointing performance through a new operation method, Extended Dynamic Pointing Assistive Program (EDPAP),…

  9. Feasibility of Adapting Multisystemic Therapy to Improve Illness Management Behaviors and Reduce Asthma Morbidity in High Risk African American Youth: A Case Series

    Science.gov (United States)

    Naar-King, Sylvie; Ellis, Deborah; Kolmodin, Karen; Cunningham, Phillippe; Secord, Elizabeth

    2009-01-01

    African-American adolescents have the highest rates of asthma morbidity and mortality, yet there are few successful behavioral interventions to improve illness management for this group. Mental health providers have an opportunity to expand their services and impact by targeting adolescents with poor asthma management. We describe the adaptation…

  10. Improved testing characteristics of austenitic and mixed welds by inverse phase adaptation of phased array signals; Verbesserung der Pruefbarkeit von Austenit- und Mischschweissverbindungen durch inverse Phasenanpassung von Gruppenstrahlerzeitsignalen

    Energy Technology Data Exchange (ETDEWEB)

    Bulavinov, A.; Kroening, M.; Walte, F. [Fraunhofer Institut Zerstoerungsfreie Pruefverfahren, Saarbruecken (Germany); Reddy, K. [QNET Engineering Ltd., Chennai (India)

    2006-07-01

    Thin-walled welds (less than 10 mm wall thickness) in austenitic pipes and mixed welds are difficult to test using non-destructive methods. This is true especially for detection of closed cracks, which is impossible by radiographic testing and problematic by ultrasonic testing. Several projects in reactor safety research provided better understanding of the testing characteristics of thes compounds. The resulting rules for writing of test specifications and for qualification of the technology employed also showed the limits of radiographic and ultrasonic testing. One important result was the simulation of the propagation of ultrasonic waves in model descriptions of welded structures as a function of the shape of the product. This allows, in principle, the applicaiton of ultrasonic migration techniques which enable consideration of phase disturbances gy structural anisotropy when the time signals of the ultrasonic sensor elements are summed up. The applicability of this 'inverse phase adaptation' was proved in heterogeneous and anisotropic model test bodies and on test bodies of the reactor safety programme. The contribution outlines the fundamentals of the technology and presents preliminary findings. (orig.)

  11. Institutional and legal arrangements in the Nile river basin: suggestions to improve the current situation toward adaptive integrated water resources management.

    Science.gov (United States)

    Abdalla, Khalid Mohamed El Hassan

    2008-01-01

    A comparative study was conducted in this work in order to investigate the current situation in the Nile river basin (NRB) regarding the institutional and legal arrangements needed to support the adaptive integrated water resources management (AIWRM) strategy. Two similar river basins were selected to achieve this comparison and to introduce suggestions to reform the current situation in the basin. Before that, the ideal situation is investigated to be as a yardstick for the desired situation. The study indicated that the necessary AIWRM criteria may include regulatory as well as implementation organizations that support shared-vision reaching with its all necessary features (cooperation, stakeholders' participation, subsidiarity, and information and knowledge exchange). Thus the main features of the desired situations regarding AIWRM in river basins are stakeholders' participation, learning-driven ability, quick response to risks and uncertainties, and finally a legal framework that could support these criteria. Although the AIWRM criteria seem to be satisfied in NRB, the basin lacks the necessary regulatory institutions as well as the legal framework. According to this, this study recommends to reform the current situation in NRB by creating regulator institutions (policy and decision making level) as well a legal framework to legitimate them.

  12. Research on the Spatio-temporal Data Model Based on the Whole Life Cycle and Improved Event%基于全生命周期和改进事件的地籍对象时空数据模型研究

    Institute of Scientific and Technical Information of China (English)

    孟令颂; 陈鹏; 童小华; 金雁敏

    2015-01-01

    As respect to the numerous objects that are recorded in the cadastre and the co-movements among the changes of cadastral objects, the whole life cycle of cadastral objects is discussed based on the classification of cadastral objects and the analysis of the spatio-temporal changes of cadastral objects. The improved definition of events in the traditional events spatio-temporal data model is proposed. The spatio-temporal data model of cadastral objects based on the whole life cycle and the improved events, which indicates the co-movements among the spatio-temporal changes of cadastral objects, is proposed and established. Furthermore, the spatio-temporal management prototype system of the cadastral objects is developed. And the results indicate that the developed prototype system is satisfied with the demands in the dynamic management of cadastral objects.%针对地籍记载的众多对象和地籍对象时空变化联动性特点,在对地籍对象分类,分析地籍对象时空变化基础上,探讨了地籍对象的全生命周期,改进了传统基于事件时空数据模型中的事件含义,建立了基于全生命周期和改进事件的地籍对象时空数据模型,体现了地籍对象时空变化的联动性,研发了地籍时空管理原型系统,实践表明,研发的系统较好地满足了地籍动态管理中的业务需求.

  13. Adaptation Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Huq, Saleemul

    2011-11-15

    Efforts to help the world's poor will face crises in coming decades as climate change radically alters conditions. Action Research for Community Adapation in Bangladesh (ARCAB) is an action-research programme on responding to climate change impacts through community-based adaptation. Set in Bangladesh at 20 sites that are vulnerable to floods, droughts, cyclones and sea level rise, ARCAB will follow impacts and adaptation as they evolve over half a century or more. National and international 'research partners', collaborating with ten NGO 'action partners' with global reach, seek knowledge and solutions applicable worldwide. After a year setting up ARCAB, we share lessons on the programme's design and move into our first research cycle.

  14. Adaptive ethnography

    DEFF Research Database (Denmark)

    Berth, Mette

    2005-01-01

    This paper focuses on the use of an adaptive ethnography when studying such phenomena as young people's use of mobile media in a learning perspective. Mobile media such as PDAs and mobile phones have a number of affordances which make them potential tools for learning. However, before we begin...... formal and informal learning contexts. The paper also proposes several adaptive methodological techniques for studying young people's interaction with mobiles....... to design and develop educational materials for mobile media platforms we must first understand everyday use and behaviour with a medium such as a mobile phone. The paper outlines the research design for a PhD project on mobile learning which focuses on mobile phones as a way to bridge the gap between...

  15. Hedonic "adaptation"

    Directory of Open Access Journals (Sweden)

    Paul Rozin

    2008-02-01

    Full Text Available People live in a world in which they are surrounded by potential disgust elicitors such as ``used'' chairs, air, silverware, and money as well as excretory activities. People function in this world by ignoring most of these, by active avoidance, reframing, or adaptation. The issue is particularly striking for professions, such as morticians, surgeons, or sanitation workers, in which there is frequent contact with major disgust elicitors. In this study, we study the ``adaptation'' process to dead bodies as disgust elicitors, by measuring specific types of disgust sensitivity in medical students before and after they have spent a few months dissecting a cadaver. Using the Disgust Scale, we find a significant reduction in disgust responses to death and body envelope violation elicitors, but no significant change in any other specific type of disgust. There is a clear reduction in discomfort at touching a cold dead body, but not in touching a human body which is still warm after death.

  16. Establishing a temporal bone laboratory: considerations for ENT specialist training.

    LENUS (Irish Health Repository)

    Fennessy, B G

    2012-02-01

    Cadaveric temporal bone dissection in a temporal bone laboratory is a vital component in training safe, competent otorhinolaryngologists. Recent controversies pertaining to organ retention have resulted in a more limited supply of temporal bones. Consequently, current trainees are dissecting far fewer bones than their consultants. We discuss the establishment of a temporal bone laboratory in the Department of Anatomy in the University College Cork, from the timely preparation and preservation of the tissue to its disposal. Comparisons are drawn between our experience and that of the United States training schemes. The temporal bone laboratory in Cork is the only one in existence in Ireland. The exposure and experience obtained by registrars rotating through Cork, has resulted in noticeable improvements in their operative abilities. The temporal bone laboratory remains a core component to training. It is hoped that this article may facilitate other units overcoming obstacles to establish a temporal bone laboratory.

  17. Adaptive noise

    OpenAIRE

    Viney, Mark; Reece, Sarah E.

    2013-01-01

    In biology, noise implies error and disorder and is therefore something which organisms may seek to minimize and mitigate against. We argue that such noise can be adaptive. Recent studies have shown that gene expression can be noisy, noise can be genetically controlled, genes and gene networks vary in how noisy they are and noise generates phenotypic differences among genetically identical cells. Such phenotypic differences can have fitness benefits, suggesting that evolution can shape noise ...

  18. Adaptable positioner

    International Nuclear Information System (INIS)

    This paper describes the circuits and programs in assembly language, developed to control the two DC motors that give mobility to a mechanical arm with two degrees of freedom. As a whole, the system is based in a adaptable regulator designed around a 8 bit microprocessor that, starting from a mode of regulation based in the successive approximation method, evolve to another mode through which, only one approximation is sufficient to get the right position of each motor. (Author) 22 fig. 6 ref

  19. Temporal Moments in Hydrogeophysics

    Science.gov (United States)

    Pollock, D.; Cirpka, O. A.

    2007-12-01

    Electrical Resistivity Tomography (ERT) has been tested as monitoring tool for salt-tracer experiments by various authors. So far, the analysis of such experiments has been done by a two-step procedure [Kemna et al., 2002; Vanderborght et al., 2005; Singha and Gorelick, 2005]. In the first step, classical geophysical inversion methods have been used to infer the distribution of electrical conductivity, which is transferred to an estimated concentration distribution of the tracer. Subsequently, the inferred concentration images were analyzed to estimate hydraulic quantities such as the velocity distribution. This approach has two disadvantages: The concentration distribution is reconstructed with a high spatial resolution, but the estimate is uncertain, and the estimation uncertainty is spatially correlated. These correlated uncertainties should be accounted for in the estimation of hydraulic conductivity from concentration values. The latter, unfortunately, is not practical because the reconstructed data sets are very large. The geophysical inversion is not enforced to be in agreement with basic hydromechanical constraints. E.g., Singha and Gorelick [2005] observed an apparent loss of solute mass when using ERT as monitoring tool. We propose considering the temporal moments of potential-difference time series. These temporal moments depend on temporal moments of concentration, which have already been used in the inference of hydraulic- conductivity distributions (Cirpka and Kitanidis, 2000). In our contribution, we present the complete set of equations leading from hydraulic conductivity via hydraulic heads, velocities, temporal moments of concentrations to temporal moments of potential differences for given flow and transport boundary conditions and electrode configurations. We also present how the sensitivity of temporal moments of potential differences on the hydraulic conductivity field can be computed without the need of storing intermediate sensitivities

  20. Temporal aspects of copper homeostasis and its crosstalk with hormones

    OpenAIRE

    Peñarrubia, Lola; Romero, Paco; Carrió-Seguí, Angela; Andrés-Bordería, Amparo; Moreno, Joaquín; Sanz, Amparo

    2015-01-01

    To cope with the dual nature of copper as being essential and toxic for cells, plants temporarily adapt the expression of copper homeostasis components to assure its delivery to cuproproteins while avoiding the interference of potential oxidative damage derived from both copper uptake and photosynthetic reactions during light hours. The circadian clock participates in the temporal organization of coordination of plant nutrition adapting metabolic responses to the daily oscillations. This time...

  1. HyCAW: Hydrological Climate change Adaptation Wizard

    Science.gov (United States)

    Bagli, Stefano; Mazzoli, Paolo; Broccoli, Davide; Luzzi, Valerio

    2016-04-01

    Changes in temporal and total water availability due to hydrologic and climate change requires an efficient use of resources through the selection of the best adaptation options. HyCAW provides a novel service to users willing or needing to adapt to hydrological change, by turning available scientific information into a user friendly online wizard that lets to: • Evaluate the monthly reduction of water availability induced by climate change; • Select the best adaptation options and visualize the benefits in terms of water balance and cost reduction; • Quantify potential of water saving by improving of water use efficiency. The tool entails knowledge of the intra-annual distribution of available surface and groundwater flows at a site under present and future (climate change) scenarios. This information is extracted from long term scenario simulation by E-HYPE (European hydrological predictions for the environment) model from Swedish Meteorological and Hydrological Institute, to quantify the expected evolution in water availability (e.g. percent reduction of soil infiltration and aquifer recharge; relative seasonal shift of runoff from summer to winter in mountain areas; etc.). Users are requested to provide in input their actual water supply on a monthly basis, both from surface and groundwater sources. Appropriate decision trees and an embedded precompiled database of Water saving technology for different sectors (household, agriculture, industrial, tourisms) lead them to interactively identify good practices for water saving/recycling/harvesting that they may implement in their specific context. Thanks to this service, users are not required to have a detailed understanding neither of data nor of hydrological processes, but may benefit of scientific analysis directly for practical adaptation in a simple and user friendly way, effectively improving their adaptation capacity. The tool is being developed under a collaborative FP7 funded project called SWITCH

  2. Improvement of adaptive Kalman filtering algorithm and its application in SINS/GPS integrated navigation%自适应Kalman滤波的改进及其在SINS/GPS组合导航中的应用

    Institute of Scientific and Technical Information of China (English)

    张利民; 张兴会; 陈增强; 李茜

    2013-01-01

    This paper uses four measures to improve the performance of adaptive Kalman filter algorithm,including judging observation outliers and outliers of the filter algorithm,extending zero to system noise variance matrix and modifying the deduction in adaptive filtering.Judging observation outliers can eliminate singular values in observation and improve the stability of the filter algorithm.Judging outliers of the filtering algorithm can avoid the excessively small values in matrix which may result in the outlier during matrix inversion.Extending zero to system noise variance can settle the incoordination of matrix dimension.Modifying the deduction in adaptive fidtering can guarantee the right side of the equations of solving noise covariance Q and observation of noise covariance R be nonnegative,so as to guarantee Q and R be nonnegative,although it sacrifices certain accuracy.The above improved adaptive Kalman filtering algorithm is applied to the SINS/GPS(strapdown inertial navigation system/global positioning system) integrated navigation,simulation results demonstrate that the combined four measures effectively improve the stability of the adaptive Kalman filtering,and ensure the accuracy of the filter.%为解决自适应Kalman滤波中存在的问题,综合采用对观测粗差和滤波结果粗差进行判断、对系统噪声方差阵扩零和修改自适应方程减去项等措施对算法进行了改进.观测粗差的判断可以避免观测奇异,提高滤波稳定性;对滤波结果粗差的判断可避免矩阵求逆时的奇异现象;对状态噪声方差阵扩零,可保证在不影响滤波精度的情况下解决滤波过程中矩阵维数不对应的问题;修改自适应方程减去项,虽然牺牲了一定的精度,但可保证求解状态噪声协方差阵Q和观测噪声协方差阵R的等式右边非负定,从而保证Q和R的非负定.将上述改进后的自适应Kalman滤波算法应用到SINS/GPS组合导航中,仿真结果表明上述改进

  3. Rapid, generalized adaptation to asynchronous audiovisual speech.

    Science.gov (United States)

    Van der Burg, Erik; Goodbourn, Patrick T

    2015-04-01

    The brain is adaptive. The speed of propagation through air, and of low-level sensory processing, differs markedly between auditory and visual stimuli; yet the brain can adapt to compensate for the resulting cross-modal delays. Studies investigating temporal recalibration to audiovisual speech have used prolonged adaptation procedures, suggesting that adaptation is sluggish. Here, we show that adaptation to asynchronous audiovisual speech occurs rapidly. Participants viewed a brief clip of an actor pronouncing a single syllable. The voice was either advanced or delayed relative to the corresponding lip movements, and participants were asked to make a synchrony judgement. Although we did not use an explicit adaptation procedure, we demonstrate rapid recalibration based on a single audiovisual event. We find that the point of subjective simultaneity on each trial is highly contingent upon the modality order of the preceding trial. We find compelling evidence that rapid recalibration generalizes across different stimuli, and different actors. Finally, we demonstrate that rapid recalibration occurs even when auditory and visual events clearly belong to different actors. These results suggest that rapid temporal recalibration to audiovisual speech is primarily mediated by basic temporal factors, rather than higher-order factors such as perceived simultaneity and source identity.

  4. A REVIEW OF ADAPTIVE AUTORECLOSURE TECHNIQUES

    Directory of Open Access Journals (Sweden)

    PHILIP YAW OKYERE

    2010-10-01

    Full Text Available Adaptive autoreclosing is a fast emerging technology for improving power system marginal stability during faults. It avoids reclosing untopermanent faults and recloses unto transient faults only after the secondary arc has extinguished. This paper presents a comprehensive review of various adaptive autoreclosure techniques. It aims at providing a broad perspective on adaptive autoreclosing techniques to researchers and application engineers.

  5. 提升幼师素质适应新课改%Improving the Quality of Kindergarten Teachers to Adapt to the New Curriculum Reform

    Institute of Scientific and Technical Information of China (English)

    王素芬

    2012-01-01

    Kindergarten teacher is the main force of preschool education curriculum reform,and their quality relates to children's development.This article explains the impact of the curriculum for early childhood teachers and my views on how to improve the comprehensive quality of kindergarten teachers.%幼师是幼教课程改革的主力军,其素质关系幼儿的发展。本文阐述了课改对幼儿教师的影响并就如何提高幼师的综合素质提出了自己的看法。

  6. 一种提高数据同步精度的自适应插值算法%An Adaptive Interpolation Algorithm to Improve Data Synchronization Precision

    Institute of Scientific and Technical Information of China (English)

    向珉江; 高厚磊; 安艳秋; 杜强; 刘凯; 苏将涛

    2012-01-01

    Abstract: Data synchronization of digital intelligent electronic device (IED) with non-synchronous sampling of electronic transformers is studied. Based on derivative precise error formula of first-order Lagrange interpolation algorithm, each instantaneous error and phasor error of inside and outside interpolation algorithms are calculated, and the impacts to relay protection and measurement are also analyzed. First-order Lagrange interpolation error is related to sampling rate and offset time. But conventional reduce errors method is increasing sampling rate only. Through study on error variation rule with offset factor, and with using parabola equation to fit complex error locus equation by least square method under the certain error, the analysis is simplified. An adaptive adjusting basic time of interpolation algorithm is put forward which can effectively reduce error proved by verification.%研究了电子式互感器采样不同步时数字化智能电子设备(IED)的数据同步问题。在推导一阶Lagrange插值算法精确误差公式的基础上,计算了内、外2种插值方法的瞬时和相量误差,以及对继电保护和测量的影响。传统减小误差的算法只涉及采样率,而一阶Lagrange插值算法与采样率和采样偏移时间都相关。通过研究误差随采样偏移时间变化的规律,用最小二乘法以抛物线方程拟合复杂误差轨迹方程,在限定误差的前提下简化了分析。在此基础上,提出了一种自适应调整插值基准时刻的算法,经分析验证该算法可以有效降低误差。

  7. Adaptation of a probabilistic method (InterVA of verbal autopsy to improve the interpretation of cause of stillbirth and neonatal death in Malawi, Nepal, and Zimbabwe

    Directory of Open Access Journals (Sweden)

    Munjanja Stephan P

    2011-08-01

    Full Text Available Abstract Background Verbal autopsy (VA is a widely used method for analyzing cause of death in absence of vital registration systems. We adapted the InterVA method to extrapolate causes of death for stillbirths and neonatal deaths from verbal autopsy questionnaires, using data from Malawi, Zimbabwe, and Nepal. Methods We obtained 734 stillbirth and neonatal VAs from recent community studies in rural areas: 169 from Malawi, 385 from Nepal, and 180 from Zimbabwe. Initial refinement of the InterVA model was based on 100 physician-reviewed VAs from Malawi. InterVA indicators and matrix probabilities for cause of death were reviewed for clinical and epidemiological coherence by a pediatrician-researcher and an epidemiologist involved in the development of InterVA. The modified InterVA model was evaluated by comparing population-level cause-specific mortality fractions and individual agreement from two methods of interpretation (physician review and InterVA for a further 69 VAs from Malawi, 385 from Nepal, and 180 from Zimbabwe. Results Case-by-case agreement between InterVA and reviewing physician diagnoses for 69 cases from Malawi, 180 cases from Zimbabwe, and 385 cases from Nepal were 83% (kappa 0.76 (0.75 - 0.80, 71% (kappa 0.41(0.32-0.51, and 74% (kappa 0.63 (0.60-0.63, respectively. The proportion of stillbirths identified as fresh or macerated by the different methods of VA interpretation was similar in all three settings. Comparing across countries, the modified InterVA method found that proportions of preterm births and deaths due to infection were higher in Zimbabwe (44% than in Malawi (28% or Nepal (20%. Conclusion The modified InterVA method provides plausible results for stillbirths and newborn deaths, broadly comparable to physician review but with the advantage of internal consistency. The method allows standardized cross-country comparisons and eliminates the inconsistencies of physician review in such comparisons.

  8. Congenital temporal triangular alopecia.

    OpenAIRE

    Bargman, H

    1984-01-01

    Congenital temporal triangular alopecia is a form of nonscarring alopecia that, as its name suggests, is present at birth. Four cases are reported. One patient underwent hair transplantation, which was successful and might be useful in other patients. Cases occurring in a father and his son suggest for the first time a genetic link.

  9. Temporal bone imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lemmerling, Marc [Algemeen Ziekenhuis Sint-Lucas, Gent (Belgium). Dept. of Radiology; Foer, Bert de (ed.) [Sint-Augustinus Ziekenhuis, Wilrijk (Belgium). Dept. of Radiology

    2015-04-01

    Complete overview of imaging of normal and diseased temporal bone. Straightforward structure to facilitate learning. Detailed consideration of newer imaging techniques, including the hot topic of diffusion-weighted imaging. Includes a chapter on anatomy that will be of great help to the novice interpreter of imaging findings. Excellent illustrations throughout. This book provides a complete overview of imaging of normal and diseased temporal bone. After description of indications for imaging and the cross-sectional imaging anatomy of the area, subsequent chapters address the various diseases and conditions that affect the temporal bone and are likely to be encountered regularly in clinical practice. The classic imaging methods are described and discussed in detail, and individual chapters are included on newer techniques such as functional imaging and diffusion-weighted imaging. There is also a strong focus on postoperative imaging. Throughout, imaging findings are documented with the aid of numerous informative, high-quality illustrations. Temporal Bone Imaging, with its straightforward structure based essentially on topography, will prove of immense value in daily practice.

  10. Temporal Photon Differentials

    DEFF Research Database (Denmark)

    Schjøth, Lars; Frisvad, Jeppe; Erleben, Kenny;

    2010-01-01

    The frame rate also used in computer animated is cause of adverse temporal aliasing effects. Most noticeable of these is a stroboscopic effect that is seen as intermittent movement of fast moving illumination. This effect can be mitigated using non-zero shutter times, effectively, constituting a ...

  11. Temporal Photon Differentials

    DEFF Research Database (Denmark)

    Schjøth, Lars; Frisvad, Jeppe Revall; Erleben, Kenny;

    2010-01-01

    The finite frame rate also used in computer animated films is cause of adverse temporal aliasing effects. Most noticeable of these is a stroboscopic effect that is seen as intermittent movement of fast moving illumination. This effect can be mitigated using non-zero shutter times, effectively, co...

  12. Information and Temporality

    Science.gov (United States)

    Flender, Christian

    2016-09-01

    Being able to give reasons for what the world is and how it works is one of the defining characteristics of modernity. Mathematical reason and empirical observation brought science and engineering to unprecedented success. However, modernity has reached a post-state where an instrumental view of technology needs revision with reasonable arguments and evidence, i.e. without falling back to superstition and mysticism. Instrumentally, technology bears the potential to ease and to harm. Easing and harming can't be controlled like the initial development of technology is a controlled exercise for a specific, mostly easing purpose. Therefore, a revised understanding of information technology is proposed based upon mathematical concepts and intuitions as developed in quantum mechanics. Quantum mechanics offers unequaled opportunities because it raises foundational questions in a precise form. Beyond instrumentalism it enables to raise the question of essences as that what remains through time what it is. The essence of information technology is acausality. The time of acausality is temporality. Temporality is not a concept or a category. It is not epistemological. As an existential and thus more comprehensive and fundamental than a concept or a category temporality is ontological; it does not simply have ontic properties. Rather it exhibits general essences. Datability, significance, spannedness and openness are general essences of equiprimordial time (temporality).

  13. Fast-twitch skeletal muscle fiber adaptation to SERCA1 deficiency in a Dutch Improved Red and White calf pseudomyotonia case.

    Science.gov (United States)

    Dorotea, Tiziano; Grünberg, Walter; Murgiano, Leonardo; Plattet, Philippe; Drögemüller, Cord; Mascarello, Francesco; Sacchetto, Roberta

    2015-11-01

    Missense mutations in ATP2A1 gene, encoding SERCA1 protein, cause a muscle disorder designed as congenital pseudomyotonia (PMT) in Chianina and Romagnola cattle or congenital muscular dystonia1 (CMD1) in Belgian Blue cattle. Although PMT is not life-threatening, CMD1 affected calves usually die within a few weeks of age as a result of respiratory complication. We have recently described a muscular disorder in a double muscle Dutch Improved Red and White cross-breed calf. Mutation analysis revealed an ATP2A1 mutation identical to that described in CMD1, even though clinical phenotype was quite similar to that of PMT. Here, we provide evidence for a deficiency of mutated SERCA1 in PMT affected muscles of Dutch Improved Red and White calf, but not of its mRNA. The reduced expression of SERCA1 is selective and not compensated by the SERCA2 isoform. By contrast, pathological muscles are characterized by a broad distribution of mitochondrial markers in all fiber types, not related to intrinsic features of double muscle phenotype and by an increased expression of sarcolemmal calcium extrusion pump. Calcium removal mechanisms, operating in muscle fibers as compensatory response aimed at lowering excessive cytoplasmic calcium concentration caused by SERCA1 deficiency, could explain the difference in severity of clinical signs. PMID:26482047

  14. Improving China’s Environmental Performance through Adaptive Implementation—A Comparative Case Study of Cleaner Production in Hangzhou and Guiyang

    Directory of Open Access Journals (Sweden)

    Ting Guan

    2014-12-01

    Full Text Available This paper examines local policy implementation of Cleaner Production (CP in China. As the major policy implementer, China’s local government plays a crucial role in promoting CP. A better understanding of the factors affecting local government’s incentives regarding CP and different strategies available to the local government can help policy makers and implementers improve CP practices and other environmental policy outcomes. This paper uses the cases of Hangzhou and Guiyang to demonstrate that local conditions of policy implementation have a direct impact on the success of CP promotion. Based on 35 in-depth interviews, statistical data and internal government reports, we find that the location-based incentives of local government strongly influence their implementation strategies; and that the choices of different strategies can bring out various policy results. From this study, the identified location-based incentives are affected by energy resource endowment, economic development stage and technological competence. The successful implementation strategies involve using different policy instruments synthetically, regulating CP service organizations by controlling their qualifications, differentiating CP subsidizations, and improving transparency of project progress and outcomes.

  15. 低能量自适应分群分层协议的改进%Improvement of low energy adaptive clustering hierarchy protocol

    Institute of Scientific and Technical Information of China (English)

    张飞鸽

    2014-01-01

    In order to avoid electing less energy nodes as cluster heads,which may cause premature death of these nodes, the selection of LEACH protocol cluster head is improved. The nodes with more residual energy are selected as cluster heads by the method of restting threshold according to their residual energy,the way of which avoids the nodes with less energy being elected as cluster heads and the cluster heads bearing overweight load. The simulation results show that the improved algorithm can effectively reduce the network energy consumption,and prolong the lifetime of the network.%为了避免能量较少节点当选为群首而过早死亡,对Leach协议群首的选取进行改进。采用结合节点剩余能量重新设置阈值的方法,选取剩余能量较多的节点作为群首,解决了能量较少节点当选为群首和群首负担载过重的问题。仿真结果表明,采用改进后的算法可以有效减少网络能量的消耗,延长网络生存时间。

  16. Communication, Technology, Temporality

    Directory of Open Access Journals (Sweden)

    Mark A. Martinez

    2012-08-01

    Full Text Available This paper proposes a media studies that foregrounds technological objects as communicative and historical agents. Specifically, I take the digital computer as a powerful catalyst of crises in communication theories and certain key features of modernity. Finally, the computer is the motor of “New Media” which is at once a set of technologies, a historical epoch, and a field of knowledge. As such the computer shapes “the new” and “the future” as History pushes its origins further in the past and its convergent quality pushes its future as a predominate medium. As treatment of information and interface suggest, communication theories observe computers, and technologies generally, for the mediated languages they either afford or foreclose to us. My project describes the figures information and interface for the different ways they can be thought of as aspects of communication. I treat information not as semantic meaning, formal or discursive language, but rather as a physical organism. Similarly an interface is not a relationship between a screen and a human visual intelligence, but is instead a reciprocal, affective and physical process of contact. I illustrate that historically there have been conceptions of information and interface complimentary to mine, fleeting as they have been in the face of a dominant temporality of mediation. I begin with a theoretically informed approach to media history, and extend it to a new theory of communication. In doing so I discuss a model of time common to popular, scientific, and critical conceptions of media technologies especially in theories of computer technology. This is a predominate model with particular rules of temporal change and causality for thinking about mediation, and limits the conditions of possibility for knowledge production about communication. I suggest a new model of time as integral to any event of observation and analysis, and that human mediation does not exhaust the

  17. Improved Correlation of the Neuropathologic Classification According to Adapted World Health Organization Classification and Outcome After Radiotherapy in Patients With Atypical and Anaplastic Meningiomas

    International Nuclear Information System (INIS)

    Purpose: To evaluate the correlation between the 1993 and 2000/2007 World Health Organization (WHO) classification with the outcome in patients with high-grade meningiomas. Patients and Methods: Between 1985 and 2004, 73 patients diagnosed with atypical or anaplastic meningiomas were treated with radiotherapy. Sections from the paraffin-embedded tumor material from 66 patients (90%) from 13 different pathology departments were re-evaluated according to the first revised WHO classification from 1993 and the revised classifications from 2000/2007. In 4 cases, the initial diagnosis meningioma was not reproducible (5%). Therefore, 62 patients with meningiomas were analyzed. Results: All 62 tumors were reclassified according to the 1993 and 2000/2007 WHO classification systems. Using the 1993 system, 7 patients were diagnosed with WHO grade I meningioma (11%), 23 with WHO grade II (37%), and 32 with WHO grade III meningioma (52%). After scoring using the 2000/2007 system, we found 17 WHO grade I meningiomas (27%), 32 WHO grade II meningiomas (52%), and 13 WHO grade III meningiomas (21%). According to the 1993 classification, the difference in overall survival was not statistically significant among the histologic subgroups (p = .96). Using the 2000/2007 WHO classifications, the difference in overall survival became significant (p = .02). Of the 62 reclassified patients 29 developed tumor progression (47%). No difference in progression-free survival was observed among the histologic subgroups (p = .44). After grading according to the 2000/2007 WHO classifications, significant differences in progression-free survival were observed among the three histologic groups (p = .005). Conclusion: The new 2000/2007 WHO classification for meningiomas showed an improved correlation between the histologic grade and outcome. This classification therefore provides a useful basis to determine the postoperative indication for radiotherapy. According to our results, a comparison of the

  18. Spatially Common Sparsity Based Adaptive Channel Estimation and Feedback for FDD Massive MIMO

    Science.gov (United States)

    Gao, Zhen; Dai, Linglong; Wang, Zhaocheng; Chen, Sheng

    2015-12-01

    This paper proposes a spatially common sparsity based adaptive channel estimation and feedback scheme for frequency division duplex based massive multi-input multi-output (MIMO) systems, which adapts training overhead and pilot design to reliably estimate and feed back the downlink channel state information (CSI) with significantly reduced overhead. Specifically, a non-orthogonal downlink pilot design is first proposed, which is very different from standard orthogonal pilots. By exploiting the spatially common sparsity of massive MIMO channels, a compressive sensing (CS) based adaptive CSI acquisition scheme is proposed, where the consumed time slot overhead only adaptively depends on the sparsity level of the channels. Additionally, a distributed sparsity adaptive matching pursuit algorithm is proposed to jointly estimate the channels of multiple subcarriers. Furthermore, by exploiting the temporal channel correlation, a closed-loop channel tracking scheme is provided, which adaptively designs the non-orthogonal pilot according to the previous channel estimation to achieve an enhanced CSI acquisition. Finally, we generalize the results of the multiple-measurement-vectors case in CS and derive the Cramer-Rao lower bound of the proposed scheme, which enlightens us to design the non-orthogonal pilot signals for the improved performance. Simulation results demonstrate that the proposed scheme outperforms its counterparts, and it is capable of approaching the performance bound.

  19. Impact of space-time mesh adaptation on solute transport modeling in porous media

    Science.gov (United States)

    Esfandiar, Bahman; Porta, Giovanni; Perotto, Simona; Guadagnini, Alberto

    2015-02-01

    We implement a space-time grid adaptation procedure to efficiently improve the accuracy of numerical simulations of solute transport in porous media in the context of model parameter estimation. We focus on the Advection Dispersion Equation (ADE) for the interpretation of nonreactive transport experiments in laboratory-scale heterogeneous porous media. When compared to a numerical approximation based on a fixed space-time discretization, our approach is grounded on a joint automatic selection of the spatial grid and the time step to capture the main (space-time) system dynamics. Spatial mesh adaptation is driven by an anisotropic recovery-based error estimator which enables us to properly select the size, shape, and orientation of the mesh elements. Adaptation of the time step is performed through an ad hoc local reconstruction of the temporal derivative of the solution via a recovery-based approach. The impact of the proposed adaptation strategy on the ability to provide reliable estimates of the key parameters of an ADE model is assessed on the basis of experimental solute breakthrough data measured following tracer injection in a nonuniform porous system. Model calibration is performed in a Maximum Likelihood (ML) framework upon relying on the representation of the ADE solution through a generalized Polynomial Chaos Expansion (gPCE). Our results show that the proposed anisotropic space-time grid adaptation leads to ML parameter estimates and to model results of markedly improved quality when compared to classical inversion approaches based on a uniform space-time discretization.

  20. Pulse front adaptive optics in multiphoton microscopy

    Science.gov (United States)

    Sun, B.; Salter, P. S.; Booth, M. J.

    2016-03-01

    The accurate focusing of ultrashort laser pulses is extremely important in multiphoton microscopy. Using adaptive optics to manipulate the incident ultrafast beam in either the spectral or spatial domain can introduce significant benefits when imaging. Here we introduce pulse front adaptive optics: manipulating an ultrashort pulse in both the spatial and temporal domains. A deformable mirror and a spatial light modulator are operated in concert to modify contours of constant intensity in space and time within an ultrashort pulse. Through adaptive control of the pulse front, we demonstrate an enhancement in the measured fluorescence from a two photon microscope.