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Sample records for classification response times

  1. Prediction, time variance, and classification of hydraulic response to recharge in two karst aquifers

    Science.gov (United States)

    Long, Andrew J.; Mahler, Barbara J.

    2013-01-01

    Many karst aquifers are rapidly filled and depleted and therefore are likely to be susceptible to changes in short-term climate variability. Here we explore methods that could be applied to model site-specific hydraulic responses, with the intent of simulating these responses to different climate scenarios from high-resolution climate models. We compare hydraulic responses (spring flow, groundwater level, stream base flow, and cave drip) at several sites in two karst aquifers: the Edwards aquifer (Texas, USA) and the Madison aquifer (South Dakota, USA). A lumped-parameter model simulates nonlinear soil moisture changes for estimation of recharge, and a time-variant convolution model simulates the aquifer response to this recharge. Model fit to data is 2.4% better for calibration periods than for validation periods according to the Nash–Sutcliffe coefficient of efficiency, which ranges from 0.53 to 0.94 for validation periods. We use metrics that describe the shapes of the impulse-response functions (IRFs) obtained from convolution modeling to make comparisons in the distribution of response times among sites and between aquifers. Time-variant IRFs were applied to 62% of the sites. Principal component analysis (PCA) of metrics describing the shapes of the IRFs indicates three principal components that together account for 84% of the variability in IRF shape: the first is related to IRF skewness and temporal spread and accounts for 51% of the variability; the second and third largely are related to time-variant properties and together account for 33% of the variability. Sites with IRFs that dominantly comprise exponential curves are separated geographically from those dominantly comprising lognormal curves in both aquifers as a result of spatial heterogeneity. The use of multiple IRF metrics in PCA is a novel method to characterize, compare, and classify the way in which different sites and aquifers respond to recharge. As convolution models are developed for

  2. Prediction, time variance, and classification of hydraulic response to recharge in two karst aquifers

    Directory of Open Access Journals (Sweden)

    A. J. Long

    2013-01-01

    Full Text Available Many karst aquifers are rapidly filled and depleted and therefore are likely to be susceptible to changes in short-term climate variability. Here we explore methods that could be applied to model site-specific hydraulic responses, with the intent of simulating these responses to different climate scenarios from high-resolution climate models. We compare hydraulic responses (spring flow, groundwater level, stream base flow, and cave drip at several sites in two karst aquifers: the Edwards aquifer (Texas, USA and the Madison aquifer (South Dakota, USA. A lumped-parameter model simulates nonlinear soil moisture changes for estimation of recharge, and a time-variant convolution model simulates the aquifer response to this recharge. Model fit to data is 2.4% better for calibration periods than for validation periods according to the Nash–Sutcliffe coefficient of efficiency, which ranges from 0.53 to 0.94 for validation periods. We use metrics that describe the shapes of the impulse-response functions (IRFs obtained from convolution modeling to make comparisons in the distribution of response times among sites and between aquifers. Time-variant IRFs were applied to 62% of the sites. Principal component analysis (PCA of metrics describing the shapes of the IRFs indicates three principal components that together account for 84% of the variability in IRF shape: the first is related to IRF skewness and temporal spread and accounts for 51% of the variability; the second and third largely are related to time-variant properties and together account for 33% of the variability. Sites with IRFs that dominantly comprise exponential curves are separated geographically from those dominantly comprising lognormal curves in both aquifers as a result of spatial heterogeneity. The use of multiple IRF metrics in PCA is a novel method to characterize, compare, and classify the way in which different sites and aquifers respond to recharge. As convolution models are

  3. Real time automatic scene classification

    OpenAIRE

    Israël, Menno; Broek, van den, Wouter; Putten, van, M.J.A.M.; Uyl, den, T.M.; Verbrugge, R.; Taatgen, N.; Schomaker, L.

    2004-01-01

    This work has been done as part of the EU VICAR (IST) project and the EU SCOFI project (IAP). The aim of the first project was to develop a real time video indexing classification annotation and retrieval system. For our systems, we have adapted the approach of Picard and Minka [3], who categorized elements of a scene automatically with so-called ’stuff’ categories (e.g., grass, sky, sand, stone). Campbell et al. [1] use similar concepts to describe certain parts of an image, which they named...

  4. Audio Classification from Time-Frequency Texture

    OpenAIRE

    Yu, Guoshen; Slotine, Jean-Jacques

    2008-01-01

    Time-frequency representations of audio signals often resemble texture images. This paper derives a simple audio classification algorithm based on treating sound spectrograms as texture images. The algorithm is inspired by an earlier visual classification scheme particularly efficient at classifying textures. While solely based on time-frequency texture features, the algorithm achieves surprisingly good performance in musical instrument classification experiments.

  5. ACCURATE TIME SERIES CLASSIFICATION USING SHAPELETS

    OpenAIRE

    M. Arathi; A. GOVARDHAN

    2014-01-01

    Time series data are sequences of values measured o ver time. One of the most recent approaches to classification of time series data is to find shape lets within a data set. Time series shapelets are time series subsequences which represent a class. In order to compare two time series sequences, existing work use s Euclidean distance measure. The problem with Euclid ean distance is that it requires data to be standardized if scales ...

  6. Online classification for time-domain astronomy

    CERN Document Server

    Lo, Kitty K; Rebbapragada, Umaa; Wagstaff, Kiri

    2014-01-01

    The advent of synoptic sky surveys has spurred the development of techniques for real-time classification of astronomical sources in order to ensure timely follow-up with appropriate instruments. Previous work has focused on algorithm selection or improved light curve representations, and naively convert light curves into structured feature sets without regard for the time span or phase of the light curves. In this paper, we highlight the violation of a fundamental machine learning assumption that occurs when archival light curves with long observational time spans are used to train classifiers that are applied to light curves with fewer observations. We propose two solutions to deal with the mismatch in the time spans of training and test light curves. The first is the use of classifier committees where each classifier is trained on light curves of different observational time spans. Only the committee member whose training set matches the test light curve time span is invoked for classification. The second ...

  7. Rotation Invariant Texture Classification Using Binary Filter Response Pattern (BFRP)

    Science.gov (United States)

    Guo, Zhenhua; Zhang, Lei; Zhang, David

    Using statistical textons for texture classification has shown great success recently. The maximal response 8 (MR8) method, which extracts an 8-dimensional feature set from 38 filters, is one of state-of-the-art rotation invariant texture classification methods. However, this method has two limitations. First, it require a training stage to build a texton library, thus the accuracy depends on the training samples; second, during classification, each 8-dimensional feature is assigned to a texton by searching for the nearest texton in the library, which is time consuming especially when the library size is big. In this paper, we propose a novel texton feature, namely Binary Filter Response Pattern (BFRP). It can well address the above two issues by encoding the filter response directly into binary representation. The experimental results on the CUReT database show that the proposed BFRP method achieves better classification result than MR8, especially when the training dataset is limited and less comprehensive.

  8. CLASSIFICATION OF THE MGR EMERGENCY RESPONSE SYSTEM

    International Nuclear Information System (INIS)

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) emergency response system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P7 ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  9. Real-Time Gender Classification by Face

    Directory of Open Access Journals (Sweden)

    Eman Fares Al Mashagba

    2016-03-01

    Full Text Available The identification of human beings based on their biometric body parts, such as face, fingerprint, gait, iris, and voice, plays an important role in electronic applications and has become a popular area of research in image processing. It is also one of the most successful applications of computer–human interaction and understanding. Out of all the abovementioned body parts,the face is one of most popular traits because of its unique features.In fact, individuals can process a face in a variety of ways to classify it by its identity, along with a number of other characteristics, such as gender, ethnicity, and age. Specifically, recognizing human gender is important because people respond differently according to gender. In this paper, we present a robust method that uses global geometry-based features to classify gender and identify age and human beings from video sequences. The features are extracted based on face detection using skin color segmentation and the computed geometric features of the face ellipse region. These geometric features are then used to form the face vector trajectories, which are inputted to a time delay neural network and are trained using the Broyden–Fletcher–Goldfarb–Shanno (BFGS function. Results show that using the suggested method with our own dataset under an unconstrained condition achieves a 100% classification rate in the training set for all application, as well as 91.2% for gender classification, 88% for age identification, and 83% for human identification in the testing set. In addition, the proposed method establishes the real-time system to be used in three applications with a simple computation for feature extraction.

  10. Sources of variation in hydrological classifications: Time scale, flow series origin and classification procedure

    Science.gov (United States)

    Peñas, Francisco J.; Barquín, José; Álvarez, César

    2016-07-01

    Classification of flow regimes in water management and hydroecological research has grown significantly in recent years. However, depending on available data and the procedures applied, there may be several credible classifications for a specific catchment. In this study, three inductive classifications derived from different initial flow data and one expert-driven classification were defined. The hydrological interpretation, statistical performance and spatial correspondence of these classifications were compared. Daily Gauged Classification (DC) was derived from daily flow data while Monthly Gauged Classification (MC) and Monthly Modeled Classification (MMC) were derived from monthly flow series, using gauged and modeled flow data, respectively. Expert-Driven Classification (EDC) was based on a Spanish nationwide hydrological classification, which is being used in the current River Basin Management Plans. The results showed that MC accounted for much of the critical hydrological information variability comprised within the DC. However, it also presented limitations regarding the inability to represent important hydroecological attributes, especially those related to droughts and high flow events. In addition, DC and MC presented an equivalent performance more than 60% of the time and obtained a mean ARI value of 0.4, indicating a similar classification structure. DC and MC outperformed MMC 100% and more than 50% of the times when they were compared by means of the classification strength and ANOVA, respectively. MMC also showed low correspondence with these classifications (ARI = 0.20). Thus, the use of modeled flow series should be limited to poorly gauged areas. Finally, the significantly reduced performance and the uneven distribution of classes found in EDC questions its application for different management objectives. This study shows that the selection of the most suitable approach according to the available data has significant implications for the

  11. Improving Music Genre Classification by Short Time Feature Integration

    DEFF Research Database (Denmark)

    Meng, Anders; Ahrendt, Peter; Larsen, Jan

    Many different short-time features (derived from 10-30ms of audio) have been proposed for music segmentation, retrieval and genre classification. Often the available time frame of the music to make a decision (the decision time horizon) is in the range of seconds instead of milliseconds. The...... decisions from the classifier, e.g. majority voting) for music genre classification....

  12. Interpretable Early Classification of Multivariate Time Series

    Science.gov (United States)

    Ghalwash, Mohamed F.

    2013-01-01

    Recent advances in technology have led to an explosion in data collection over time rather than in a single snapshot. For example, microarray technology allows us to measure gene expression levels in different conditions over time. Such temporal data grants the opportunity for data miners to develop algorithms to address domain-related problems,…

  13. Automatic classification of time-variable X-ray sources

    CERN Document Server

    Lo, Kitty K; Murphy, Tara; Gaensler, B M

    2014-01-01

    To maximize the discovery potential of future synoptic surveys, especially in the field of transient science, it will be necessary to use automatic classification to identify some of the astronomical sources. The data mining technique of supervised classification is suitable for this problem. Here, we present a supervised learning method to automatically classify variable X-ray sources in the second \\textit{XMM-Newton} serendipitous source catalog (2XMMi-DR2). Random Forest is our classifier of choice since it is one of the most accurate learning algorithms available. Our training set consists of 873 variable sources and their features are derived from time series, spectra, and other multi-wavelength contextual information. The 10-fold cross validation accuracy of the training data is ${\\sim}$97% on a seven-class data set. We applied the trained classification model to 411 unknown variable 2XMM sources to produce a probabilistically classified catalog. Using the classification margin and the Random Forest der...

  14. Designing Information Measures for Real-time Lightcurve Classification

    Science.gov (United States)

    Jones, David Edward; Chen, Yang; Meng, Xiao-Li; Siemiginowska, Aneta; Kashyap, Vinay

    2016-01-01

    Since telescope time is limited, real-time lightcurve classification involves carefully selecting future time points at which sources must be observed in order to maximize the information that will be gained for classification. We propose a framework for constructing measures of information for testing/classification/model-selection and demonstrate their use in experimental design. Degroot (1962) developed a general framework for constructing Bayesian measures of the expected information that an experiment will provide for estimation, and our framework analogously constructs measures of information for hypothesis testing. Such test information measures are most useful for model selection and classification problems. Indeed, our framework suggests a probability based measure of test information, which in decision problems has more appealing properties than variance based measures. In the case of lightcurve classification, we adapt our designs to penalize long waits until the next observation time. Lastly, we consider ways to address other aspects of the problem, such as uncertainty estimation arising due to contamination from nearby contaminating sources or background diffuse emission. We acknowledge support from Smithsonian Competitive Grants Fund 40488100HH0043 and NSF grant DMS 1208791.

  15. REAL-TIME INTELLIGENT MULTILAYER ATTACK CLASSIFICATION SYSTEM

    Directory of Open Access Journals (Sweden)

    T. Subbhulakshmi

    2014-01-01

    Full Text Available Intrusion Detection Systems (IDS takes the lion’s share of the current security infrastructure. Detection of intrusions is vital for initiating the defensive procedures. Intrusion detection was done by statistical and distance based methods. A threshold value is used in these methods to indicate the level of normalcy. When the network traffic crosses the level of normalcy then above which it is flagged as anomalous. When there are occurrences of new intrusion events which are increasingly a key part of system security, the statistical techniques cannot detect them. To overcome this issue, learning techniques are used which helps in identifying new intrusion activities in a computer system. The objective of the proposed system designed in this paper is to classify the intrusions using an Intelligent Multi Layered Attack Classification System (IMLACS which helps in detecting and classifying the intrusions with improved classification accuracy. The intelligent multi layered approach contains three intelligent layers. The first layer involves Binary Support Vector Machine classification for detecting the normal and attack. The second layer involves neural network classification to classify the attacks into classes of attacks. The third layer involves fuzzy inference system to classify the attacks into various subclasses. The proposed IMLACS can be able to detect an intrusion behavior of the networks since the system contains a three intelligent layer classification and better set of rules. Feature selection is also used to improve the time of detection. The experimental results show that the IMLACS achieves the Classification Rate of 97.31%.

  16. Binary classification of real sequences by discrete-time systems

    Science.gov (United States)

    Kaliski, M. E.; Johnson, T. L.

    1979-01-01

    This paper considers a novel approach to coding or classifying sequences of real numbers through the use of (generally nonlinear) finite-dimensional discrete-time systems. This approach involves a finite-dimensional discrete-time system (which we call a real acceptor) in cascade with a threshold type device (which we call a discriminator). The proposed classification scheme and the exact nature of the classification problem are described, along with two examples illustrating its applicability. Suggested approaches for further research are given.

  17. Time Series Classification by Class-Based Mahalanobis Distances

    CERN Document Server

    Prekopcsák, Zoltán

    2010-01-01

    To classify time series by nearest neighbor, we need to specify or learn a distance. We consider several variations of the Mahalanobis distance and the related Large Margin Nearest Neighbor Classification (LMNN). We find that the conventional Mahalanobis distance is counterproductive. However, both LMNN and the class-based diagonal Mahalanobis distance are competitive.

  18. Hierarchical Real-time Network Traffic Classification Based on ECOC

    Directory of Open Access Journals (Sweden)

    Yaou Zhao

    2013-09-01

    Full Text Available Classification of network traffic is basic and essential for manynetwork researches and managements. With the rapid development ofpeer-to-peer (P2P application using dynamic port disguisingtechniques and encryption to avoid detection, port-based and simplepayload-based network traffic classification methods were diminished.An alternative method based on statistics and machine learning hadattracted researchers' attention in recent years. However, most ofthe proposed algorithms were off-line and usually used a single classifier.In this paper a new hierarchical real-time model was proposed which comprised of a three tuple (source ip, destination ip and destination portlook up table(TT-LUT part and layered milestone part. TT-LUT was used to quickly classify short flows whichneed not to pass the layered milestone part, and milestones in layered milestone partcould classify the other flows in real-time with the real-time feature selection and statistics.Every milestone was a ECOC(Error-Correcting Output Codes based model which was usedto improve classification performance. Experiments showed that the proposedmodel can improve the efficiency of real-time to 80%, and themulti-class classification accuracy encouragingly to 91.4% on the datasets which had been captured from the backbone router in our campus through a week.

  19. Automatic classification of time-variable X-ray sources

    International Nuclear Information System (INIS)

    To maximize the discovery potential of future synoptic surveys, especially in the field of transient science, it will be necessary to use automatic classification to identify some of the astronomical sources. The data mining technique of supervised classification is suitable for this problem. Here, we present a supervised learning method to automatically classify variable X-ray sources in the Second XMM-Newton Serendipitous Source Catalog (2XMMi-DR2). Random Forest is our classifier of choice since it is one of the most accurate learning algorithms available. Our training set consists of 873 variable sources and their features are derived from time series, spectra, and other multi-wavelength contextual information. The 10 fold cross validation accuracy of the training data is ∼97% on a 7 class data set. We applied the trained classification model to 411 unknown variable 2XMM sources to produce a probabilistically classified catalog. Using the classification margin and the Random Forest derived outlier measure, we identified 12 anomalous sources, of which 2XMM J180658.7–500250 appears to be the most unusual source in the sample. Its X-ray spectra is suggestive of a ultraluminous X-ray source but its variability makes it highly unusual. Machine-learned classification and anomaly detection will facilitate scientific discoveries in the era of all-sky surveys.

  20. Improving Music Genre Classification by Short-Time Feature Integration

    DEFF Research Database (Denmark)

    Meng, Anders; Ahrendt, Peter; Larsen, Jan

    2005-01-01

    Many different short-time features, using time windows in the size of 10-30 ms, have been proposed for music segmentation, retrieval and genre classification. However, often the available time frame of the music to make the actual decision or comparison (the decision time horizon) is in the range...... of seconds instead of milliseconds. The problem of making new features on the larger time scale from the short-time features (feature integration) has only received little attention. This paper investigates different methods for feature integration and late information fusion for music genre...

  1. Response times to conceptual questions

    Science.gov (United States)

    Lasry, Nathaniel; Watkins, Jessica; Mazur, Eric; Ibrahim, Ahmed

    2013-09-01

    We measured the time taken by students to respond to individual Force Concept Inventory (FCI) questions. We examine response time differences between correct and incorrect answers, both before and after instruction. We also determine the relation between response time and expressed confidence. Our data reveal three results of interest. First, response times are longer for incorrect answers than for correct ones, indicating that distractors are not automatic choices. Second, response times increase after instruction for both correct and incorrect answers, supporting the notion that instruction changes students' approach to conceptual questions. Third, response times are inversely related to students' expressed confidence; the lower their confidence, the longer it takes to respond.

  2. Automated Feature Design for Time Series Classification by Genetic Programming

    OpenAIRE

    Harvey, Dustin Yewell

    2014-01-01

    Time series classification (TSC) methods discover and exploit patterns in time series and other one-dimensional signals. Although many accurate, robust classifiers exist for multivariate feature sets, general approaches are needed to extend machine learning techniques to make use of signal inputs. Numerous applications of TSC can be found in structural engineering, especially in the areas of structural health monitoring and non-destructive evaluation. Additionally, the fields of process contr...

  3. Automatic parquet block sorting using real-time spectral classification

    Science.gov (United States)

    Astrom, Anders; Astrand, Erik; Johansson, Magnus

    1999-03-01

    This paper presents a real-time spectral classification system based on the PGP spectrograph and a smart image sensor. The PGP is a spectrograph which extracts the spectral information from a scene and projects the information on an image sensor, which is a method often referred to as Imaging Spectroscopy. The classification is based on linear models and categorizes a number of pixels along a line. Previous systems adopting this method have used standard sensors, which often resulted in poor performance. The new system, however, is based on a patented near-sensor classification method, which exploits analogue features on the smart image sensor. The method reduces the enormous amount of data to be processed at an early stage, thus making true real-time spectral classification possible. The system has been evaluated on hardwood parquet boards showing very good results. The color defects considered in the experiments were blue stain, white sapwood, yellow decay and red decay. In addition to these four defect classes, a reference class was used to indicate correct surface color. The system calculates a statistical measure for each parquet block, giving the pixel defect percentage. The patented method makes it possible to run at very high speeds with a high spectral discrimination ability. Using a powerful illuminator, the system can run with a line frequency exceeding 2000 line/s. This opens up the possibility to maintain high production speed and still measure with good resolution.

  4. Real-Time Fault Classification for Plasma Processes

    Directory of Open Access Journals (Sweden)

    Ryan Yang

    2011-07-01

    Full Text Available Plasma process tools, which usually cost several millions of US dollars, are often used in the semiconductor fabrication etching process. If the plasma process is halted due to some process fault, the productivity will be reduced and the cost will increase. In order to maximize the product/wafer yield and tool productivity, a timely and effective fault process detection is required in a plasma reactor. The classification of fault events can help the users to quickly identify fault processes, and thus can save downtime of the plasma tool. In this work, optical emission spectroscopy (OES is employed as the metrology sensor for in-situ process monitoring. Splitting into twelve different match rates by spectrum bands, the matching rate indicator in our previous work (Yang, R.; Chen, R.S. Sensors 2010, 10, 5703-5723 is used to detect the fault process. Based on the match data, a real-time classification of plasma faults is achieved by a novel method, developed in this study. Experiments were conducted to validate the novel fault classification. From the experimental results, we may conclude that the proposed method is feasible inasmuch that the overall accuracy rate of the classification for fault event shifts is 27 out of 28 or about 96.4% in success.

  5. Response time of internauts

    Science.gov (United States)

    Johansen, Anders

    2001-07-01

    A new experiment measuring the dynamical response of the Internet population to a “point-like” perturbation has been performed. The nature of the perturbation was that of an announcement, specifically a web-interview on stock market crashes, which contained the URL to the author's articles on the subject. It was established that the download rate obeys the relation ≈1/ t in qualitative agreement with previously reported results.

  6. A NOVEL APPROACH FOR REAL TIME INTERNET TRAFFIC CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    Rupesh Jaiswal

    2015-09-01

    Full Text Available Real time internet traffic classification is imperative for service discrimination, network security and network monitoring. Classification of traffic depends on initial first few network packets of full flows of captured IP traffic. Practically, the real world framework situation expects correct conclusion of classification well before a flow has ended even if the start of the Traffic flow is missed. This is achieved by calculating features from few N network packets, taken at any random time instant at any random point in the duration of flow. This research proposes a novel parameter Relative Uncertainty (RU to estimate the level of diversity of internet traffic and can then be used for characterization of internet traffic. Small sub-flows from Full-flows are selected based on minimum RU value (MRUB-SFs: Minimum RU Based Sub Flows, and then features are calculated for training the C4.5 ML classifier. Experimentation is carried out with various standard datasets and results stable accuracy of 99.3167% for different classes of applications.

  7. Classification of time series patterns from complex dynamic systems

    Energy Technology Data Exchange (ETDEWEB)

    Schryver, J.C.; Rao, N.

    1998-07-01

    An increasing availability of high-performance computing and data storage media at decreasing cost is making possible the proliferation of large-scale numerical databases and data warehouses. Numeric warehousing enterprises on the order of hundreds of gigabytes to terabytes are a reality in many fields such as finance, retail sales, process systems monitoring, biomedical monitoring, surveillance and transportation. Large-scale databases are becoming more accessible to larger user communities through the internet, web-based applications and database connectivity. Consequently, most researchers now have access to a variety of massive datasets. This trend will probably only continue to grow over the next several years. Unfortunately, the availability of integrated tools to explore, analyze and understand the data warehoused in these archives is lagging far behind the ability to gain access to the same data. In particular, locating and identifying patterns of interest in numerical time series data is an increasingly important problem for which there are few available techniques. Temporal pattern recognition poses many interesting problems in classification, segmentation, prediction, diagnosis and anomaly detection. This research focuses on the problem of classification or characterization of numerical time series data. Highway vehicles and their drivers are examples of complex dynamic systems (CDS) which are being used by transportation agencies for field testing to generate large-scale time series datasets. Tools for effective analysis of numerical time series in databases generated by highway vehicle systems are not yet available, or have not been adapted to the target problem domain. However, analysis tools from similar domains may be adapted to the problem of classification of numerical time series data.

  8. Real time classification of viruses in 12 dimensions.

    Science.gov (United States)

    Yu, Chenglong; Hernandez, Troy; Zheng, Hui; Yau, Shek-Chung; Huang, Hsin-Hsiung; He, Rong Lucy; Yang, Jie; Yau, Stephen S-T

    2013-01-01

    The International Committee on Taxonomy of Viruses authorizes and organizes the taxonomic classification of viruses. Thus far, the detailed classifications for all viruses are neither complete nor free from dispute. For example, the current missing label rates in GenBank are 12.1% for family label and 30.0% for genus label. Using the proposed Natural Vector representation, all 2,044 single-segment referenced viral genomes in GenBank can be embedded in [Formula: see text]. Unlike other approaches, this allows us to determine phylogenetic relations for all viruses at any level (e.g., Baltimore class, family, subfamily, genus, and species) in real time. Additionally, the proposed graphical representation for virus phylogeny provides a visualization of the distribution of viruses in [Formula: see text]. Unlike the commonly used tree visualization methods which suffer from uniqueness and existence problems, our representation always exists and is unique. This approach is successfully used to predict and correct viral classification information, as well as to identify viral origins; e.g. a recent public health threat, the West Nile virus, is closer to the Japanese encephalitis antigenic complex based on our visualization. Based on cross-validation results, the accuracy rates of our predictions are as high as 98.2% for Baltimore class labels, 96.6% for family labels, 99.7% for subfamily labels and 97.2% for genus labels. PMID:23717598

  9. Spectrophotometric Rapid-Response Classification of Near-Earth Objects

    Science.gov (United States)

    Mommert, Michael; Trilling, David; Butler, Nat; Axelrod, Tim; Moskovitz, Nick; Jedicke, Robert; Pichardo, Barbara; Reyes-Ruiz, Mauricio

    2015-08-01

    Small NEOs are, as a whole, poorly characterized, and we know nothing about the physical properties of the majority of all NEOs. The rate of NEO discoveries is increasing each year, and projects to determine the physical properties of NEOs are lagging behind. NEOs are faint, and generally even fainter by the time that follow-up characterizations can be made days or weeks after their discovery. There is a need for a high-throughput, high-efficiency physical characterization strategy in which hundreds of faint NEOs can be characterized each year. Broadband photometry in the near-infrared is sufficiently diagnostic to assign taxonomic types, and hence constrain both the individual and ensemble properties of NEOs.We present results from our rapid response near-infrared spectrophotometric characterization program of NEOs. We are using UKIRT (on Mauna Kea) and the RATIR instrument on the 1.5m telescope at the San Pedro Martir Observatory (Mexico) to allow us to make observations most nights of the year in robotic/queue mode. We derive taxonomic classifications for our targets using machine-learning techniques that are trained on a large sample of measured asteroid spectra. For each target we assign a probability for it to belong to a number of different taxa. Target selection, observation, data reduction, and analysis are highly automated, requiring only a minimum of user interaction, making this technique powerful and fast. Our targets are NEOs that are generally too faint for other characterization techniques, or would require many hours of large telescope time.

  10. Decision time horizon for music genre classification using short time features

    DEFF Research Database (Denmark)

    Ahrendt, Peter; Meng, Anders; Larsen, Jan

    2004-01-01

    In this paper music genre classification has been explored with special emphasis on the decision time horizon and ranking of tapped-delay-line short-time features. Late information fusion as e.g. majority voting is compared with techniques of early information fusion such as dynamic PCA (DPCA). The...

  11. Non-Hodgkin lymphoma response evaluation with MRI texture classification

    Directory of Open Access Journals (Sweden)

    Heinonen Tomi T

    2009-06-01

    Full Text Available Abstract Background To show magnetic resonance imaging (MRI texture appearance change in non-Hodgkin lymphoma (NHL during treatment with response controlled by quantitative volume analysis. Methods A total of 19 patients having NHL with an evaluable lymphoma lesion were scanned at three imaging timepoints with 1.5T device during clinical treatment evaluation. Texture characteristics of images were analyzed and classified with MaZda application and statistical tests. Results NHL tissue MRI texture imaged before treatment and under chemotherapy was classified within several subgroups, showing best discrimination with 96% correct classification in non-linear discriminant analysis of T2-weighted images. Texture parameters of MRI data were successfully tested with statistical tests to assess the impact of the separability of the parameters in evaluating chemotherapy response in lymphoma tissue. Conclusion Texture characteristics of MRI data were classified successfully; this proved texture analysis to be potential quantitative means of representing lymphoma tissue changes during chemotherapy response monitoring.

  12. ECG Signals Classification using Statistical and Time-Frequency Features

    Directory of Open Access Journals (Sweden)

    Cristina STOLOJESCU

    2012-03-01

    Full Text Available Cardiovascular diseases are one of the most frequent and dangerous problems in modern society nowadays. Therefore, it is very difficult to take immediate measures without real time electrocardiogram information. Unfortunately ECG signals, during their acquisition process, are affected by various types of noise and artifacts due to the movement, or breathing of the patient, electrode contact, power-line interferences, etc. The aim of this study was to develop an algorithm to detect and classify four types of electrocardiograms (ECG: without noise, or containing one of the following three types of noise: baseline wonder, muscular noise or electrode motion artifact. The classification was made using descriptive statistics. The Stationary Wavelet Transform (SWT was applied in order to extract features from input signals. The main reasons for using this transform are the properties of good representation of non-stationary signals such as ECG signals and the possibility of dividing the signal into different bands of frequency. The proposed method was tested using real ECG signals affected by noise from the MIT-BIH arrhythmia database. The goal was to analyze the percentage of the well classified signals. The proposed algorithm showed good results, assuring a good classification with more than 90% well classified signals for each type of ECGs.

  13. Assessing recognition memory using confidence ratings and response times.

    Science.gov (United States)

    Weidemann, Christoph T; Kahana, Michael J

    2016-04-01

    Classification of stimuli into categories (such as 'old' and 'new' in tests of recognition memory or 'present' versus 'absent' in signal detection tasks) requires the mapping of internal signals to discrete responses. Introspective judgements about a given choice response are regularly employed in research, legal and clinical settings in an effort to measure the signal that is thought to be the basis of the classification decision. Correlations between introspective judgements and task performance suggest that such ratings often do convey information about internal states that are relevant for a given task, but well-known limitations of introspection call the fidelity of this information into question. We investigated to what extent response times can reveal information usually assessed with explicit confidence ratings. We quantitatively compared response times to confidence ratings in their ability to qualify recognition memory decisions and found convergent results suggesting that much of the information from confidence ratings can be obtained from response times. PMID:27152209

  14. Electron Neutrino Classification in Liquid Argon Time Projection Chamber Detector

    CERN Document Server

    Płoński, Piotr; Sulej, Robert; Zaremba, Krzysztof

    2015-01-01

    Neutrinos are one of the least known elementary particles. The detection of neutrinos is an extremely difficult task since they are affected only by weak sub-atomic force or gravity. Therefore large detectors are constructed to reveal neutrino's properties. Among them the Liquid Argon Time Projection Chamber (LAr-TPC) detectors provide excellent imaging and particle identification ability for studying neutrinos. The computerized methods for automatic reconstruction and identification of particles are needed to fully exploit the potential of the LAr-TPC technique. Herein, the novel method for electron neutrino classification is presented. The method constructs a feature descriptor from images of observed event. It characterizes the signal distribution propagated from vertex of interest, where the particle interacts with the detector medium. The classifier is learned with a constructed feature descriptor to decide whether the images represent the electron neutrino or cascade produced by photons. The proposed ap...

  15. Dynamic Bayesian Networks in Classification-and-Ranking Architecture of Response Generation

    Directory of Open Access Journals (Sweden)

    Aida Mustapha

    2011-01-01

    Full Text Available Problem statement: The first component in classification-and-ranking architecture is a Bayesian classifier that classifies user utterances into response classes based on their semantic and pragmatic interpretations. Bayesian networks are sufficient if data is limited to single user input utterance. However, if the classifier is able to collate features from a sequence of previous n-1 user utterances, the additional information may or may not improve the accuracy rate in response classification. Approach: This article investigates the use of dynamic Bayesian networks to include time-series information in the form of extended features from preceding utterances. The experiment was conducted on SCHISMA corpus, which is a mixed-initiative, transaction dialogue in theater reservation. Results: The results show that classification accuracy is improved, but rather insignificantly. The accuracy rate tends to deteriorate as time-span of dialogue is increased. Conclusion: Although every response utterance reflects form and behavior that are expected by the preceding utterance, influence of meaning and intentions diminishes throughout time as the conversation stretches to longer duration.

  16. Classification

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2013-01-01

    In this article, Renee Clary and James Wandersee describe the beginnings of "Classification," which lies at the very heart of science and depends upon pattern recognition. Clary and Wandersee approach patterns by first telling the story of the "Linnaean classification system," introduced by Carl Linnacus (1707-1778), who is…

  17. Real-time Image Scene Classification and Segmentation System

    Directory of Open Access Journals (Sweden)

    Sheng-Fuu Lin

    2013-10-01

    Full Text Available An original approach is proposed. Called the Pre-Segmented Region of Interest Classification Scene System (PSROI, this system is able both to classify a scene during a digital camera's pre-capture phase, and to determine image processor parameters that will determine the quality of the final picture: white balancing, exposure, and focus. Additionally, it also integrates with the focusing system. An imagein the classification scene system is given a value, called the focus weight. The focus weight ensures that the selected classification scene is more suitable for user vision. In the scene classification system, three scenes are set: portrait, landscape, and beach/snow. In order to perform the classification more quickly, the operation region of the image shrinks, and less computation is applied to build the system. Experimental results show that the proposed system is capable of effectively classifying scenes into the right categories within 0.2 s..

  18. A new complexity measure for time series analysis and classification

    Science.gov (United States)

    Nagaraj, Nithin; Balasubramanian, Karthi; Dey, Sutirth

    2013-07-01

    Complexity measures are used in a number of applications including extraction of information from data such as ecological time series, detection of non-random structure in biomedical signals, testing of random number generators, language recognition and authorship attribution etc. Different complexity measures proposed in the literature like Shannon entropy, Relative entropy, Lempel-Ziv, Kolmogrov and Algorithmic complexity are mostly ineffective in analyzing short sequences that are further corrupted with noise. To address this problem, we propose a new complexity measure ETC and define it as the "Effort To Compress" the input sequence by a lossless compression algorithm. Here, we employ the lossless compression algorithm known as Non-Sequential Recursive Pair Substitution (NSRPS) and define ETC as the number of iterations needed for NSRPS to transform the input sequence to a constant sequence. We demonstrate the utility of ETC in two applications. ETC is shown to have better correlation with Lyapunov exponent than Shannon entropy even with relatively short and noisy time series. The measure also has a greater rate of success in automatic identification and classification of short noisy sequences, compared to entropy and a popular measure based on Lempel-Ziv compression (implemented by Gzip).

  19. Predictability, stationarity, and classification of hydraulic responses to recharge in two karst aquifers

    Directory of Open Access Journals (Sweden)

    A. J. Long

    2012-08-01

    Full Text Available Karst aquifers, many of which are rapidly filled and depleted, are likely to be highly susceptible to changes in short-term climate variability. Here we explore methods that could be applied to model site-specific hydraulic responses, with the intent of simulating these responses to different climate scenarios from high-resolution climate models. We compare hydraulic responses (spring flow, groundwater level, and stream base flow at several sites in two karst aquifers: the Edwards aquifer (Texas, USA and the Madison aquifer (South Dakota, USA. A one-dimensional, lumped-parameter model simulates nonstationary soil moisture changes for estimation of recharge, and a nonstationary convolution model simulates the aquifer response to this recharge. Model fit to data was 4% better for calibration periods than for validation periods. We use metrics that describe the shapes of the impulse-response functions (IRFs obtained from convolution modeling to make comparisons in the distribution of response times among sites and among aquifers. Combined principal component analysis and cluster analysis of metrics describing the shapes of the IRFs separated those sites with IRFs having a large ratio of the mean response time to the system memory from those with large skewness and kurtosis. Classification of the IRF metrics indicate that there is a range of IRF characteristics for different site types (i.e., spring flow, groundwater level, base flow within a karst system. Further, similar site types did not necessarily display similar IRFs. Results indicate that the differences existing within either aquifer are larger than the differences between the two aquifers and that the two aquifers are similar according to this classification. The use of multiple metrics to describe the IRFs provides a novel way to characterize and compare the way in which multiple sites respond to recharge. As convolution models are developed for additional aquifers, they could contribute

  20. ASAS classification criteria for axial spondyloarthritis: time to modify.

    Science.gov (United States)

    Akkoc, Nurullah; Khan, Muhammad A

    2016-06-01

    The relationship between ankylosing spondylitis and the recently proposed entity called axial spondyloarthritis with its radiographic and non-radiographic forms that have been defined by the Assessment of Spondyloarthritis International Society (ASAS) criteria for axial spondyloarthritis (axSpA), is currently being debated. The Food and Drug Agency (FDA) had criticized the ASAS criteria and the studies which used these criteria to enroll patients in a clinical trial of certolizumab and adalimumab for the treatment of non-radiographic axial spondyloarthritis. The primary aim of classification criteria is to create homogenous patient populations for basic and clinical research. But the multi-arm construct of the ASAS criteria is a potential source of heterogeneity reducing their utility. Criteria sets should be regarded as dynamic concepts open to modifications or updates as our knowledge advances. We provide evidence to conclude that it is time to modify the ASAS Criteria for axSpA, and we propose some of the steps that can be taken to start moving forward in improving the validity of these criteria. PMID:27094940

  1. An automated, real time classification system for biological and anthropogenic sounds from fixed ocean observatories

    OpenAIRE

    Zaugg, Serge Alain; Schaar, Mike van der; Houegnigan, Ludwig; André, Michel

    2010-01-01

    The automated, real time classification of acoustic events in the marine environment is an important tool to study anthropogenic sound pollution, marine mammals and for mitigating human activities that are potentially harmful. We present a real time classification system targeted at many important groups of acoustic events (clicks, buzzes, calls, whistles from several cetacean species, tonal and impulsive shipping noise and explosions). The achieved classification performance ...

  2. Children migraine syndrome: Definition and classification through the time

    Directory of Open Access Journals (Sweden)

    Knežević-Pogančev Marija

    2008-01-01

    Full Text Available Introduction Even today, the migraine syndrome is not completely defined knowing that it does not have either clear laboratory correlate or objectively defining marker. There is a great number of differential diagnostic references to define and classify migraine headaches; from Galen to ICHD-II (International Classification of Headache Disorders, from September 2003. Migraine syndrome represents a current problem of both pediatrics and children *s neurology. The aim of this paper is to understand and define the migraine syndrome among children through the history of medical science, in order to enable the interpretation of the most acceptable defining and classification criteria of the children migraine syndrome. Definition and classification Sensory, vegetative and affective phenomena of migraine, recognizable only among people, with striking quantitative and qualitative variations depending on the patient, define the migraine syndrome of children in general. There are no completely reliable principles or guidelines which would enable the accurate, precise and quick diagnosis, or differential diagnosis of children's migraine syndrome. Vahlquist is the first one to give special criteria to diagnose children's headache. His criteria were invalid because of insisting on headaches being unilateral. Classification criteria for migraine in children were given by Bille in 1962, Prensky in 1976, Deubner in 1977, Congdon and Forsythe in 1979, Tomasi in 1980, Sillanappa in 1982, Kurt: and Barlow in 1984, Hockaday in 1988. 1HS classification was brought by consensus in 1988, and it was last modified in September 2003, when a consensus was reached about applying the ICHD-II International Classification of Headache Disorders. Conclusion Being insufficiently defined and incompletely etiologically, clinically and therapeutically clear, children's migraine syndrome represents a striking example of interdisciplinary, scientific, health, practical and clinical

  3. Classification of $SU(4) \\times SU(2) \\times U(1)$ Heterotic-String Models

    CERN Document Server

    Faraggi, Alon E

    2014-01-01

    The free fermionic construction of the heterotic string in four dimensions produced a large space of three generation models with the underlying $SO(10)$ embedding of the Standard Model states. The $SO(10)$ symmetry is broken to a subgroup directly at the string scale. Over the past few years free fermionic models with the Pati-Salam and flipped $SU(5)$ subgroups have been classified. In this paper we extend this classification program to models in which the $SO(10)$ symmetry is broken at the string level to the $SU(4)\\times SU(2)_L\\times U(1)_R$ (SU421) subgroup. The subspace of free fermionic models that we consider corresponds to symmetric ${\\mathbb{Z}}_2 \\times {\\mathbb{Z}}_2$ orbifolds. We provide a general argument that shows that this class of SU421 free fermionic models cannot produce viable three generation models.

  4. Mapping Plant Functional Types over Broad Mountainous Regions: A Hierarchical Soft Time-Space Classification Applied to the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Danlu Cai

    2014-04-01

    Full Text Available Research on global climate change requires plant functional type (PFT products. Although several PFT mapping procedures for remote sensing imagery are being used, none of them appears to be specifically designed to map and evaluate PFTs over broad mountainous areas which are highly relevant regions to identify and analyze the response of natural ecosystems. We present a methodology for generating soft classifications of PFTs from remotely sensed time series that are based on a hierarchical strategy by integrating time varying integrated NDVI and phenological information with topography: (i Temporal variability: a Fourier transform of a vegetation index (MODIS NDVI, 2006 to 2010. (ii Spatial partitioning: a primary image segmentation based on a small number of thresholds applied to the Fourier amplitude. (iii Classification by a supervised soft classification step is based on a normalized distance metric constructed from a subset of Fourier coefficients and complimentary altitude data from a digital elevation model. Applicability and effectiveness is tested for the eastern Tibetan Plateau. A classification nomenclature is determined from temporally stable pixels in the MCD12Q1 time series. Overall accuracy statistics of the resulting classification reveal a gain of about 7% from 64.4% compared to 57.7% by the MODIS PFT products.

  5. Children migraine syndrome: Definition and classification through the time

    OpenAIRE

    Knežević-Pogančev Marija

    2008-01-01

    Introduction Even today, the migraine syndrome is not completely defined knowing that it does not have either clear laboratory correlate or objectively defining marker. There is a great number of differential diagnostic references to define and classify migraine headaches; from Galen to ICHD-II (International Classification of Headache Disorders), from September 2003. Migraine syndrome represents a current problem of both pediatrics and children *s neurology. The aim of this paper is to under...

  6. A real time method of contaminant classification using conventional water quality sensors.

    Science.gov (United States)

    Liu, Shuming; Che, Han; Smith, Kate; Chang, Tian

    2015-05-01

    Early warning systems are often used to detect deliberate and accidental contamination events in a water source. After contamination detection, it is important to classify the type of contaminant quickly to provide support for implementation of remediation attempts. Conventional methods commonly rely on laboratory-based analysis or qualitative geometry analysis, which require long analysis time or suffer low true positive rate. This paper proposes a real time contaminant classification method, which discriminates contaminants based on quantitative analysis. The proposed method utilizes the Mahalanobis distance of feature vectors to classify the type of contaminant. The performance and robustness of the proposed method were evaluated using data from contaminant injection experiments and through an uncertainty analysis. An advantage of the proposed method is that it can classify the type of contaminant in minutes with no significant compromise on true positive rate. This will facilitate fast remediation response to contamination events in a water system. PMID:25700352

  7. Prognostic prediction through biclustering-based classification of clinical gene expression time series.

    Science.gov (United States)

    Carreiro, André V; Anunciação, Orlando; Carriço, João A; Madeira, Sara C

    2011-01-01

    The constant drive towards a more personalized medicine led to an increasing interest in temporal gene expression analyzes. It is now broadly accepted that considering a temporal perpective represents a great advantage to better understand disease progression and treatment results at a molecular level. In this context, biclustering algorithms emerged as an important tool to discover local expression patterns in biomedical applications, and CCC-Biclustering arose as an efficient algorithm relying on the temporal nature of data to identify all maximal temporal patterns in gene expression time series. In this work, CCC-Biclustering was integrated in new biclustering-based classifiers for prognostic prediction. As case study we analyzed multiple gene expression time series in order to classify the response of Multiple Sclerosis patients to the standard treatment with Interferon-β, to which nearly half of the patients reveal a negative response. In this scenario, using an effective predictive model of a patient's response would avoid useless and possibly harmful therapies for the non-responder group. The results revealed interesting potentialities to be further explored in classification problems involving other (clinical) time series. PMID:21926438

  8. EEG Eye State Identification Using Incremental Attribute Learning with Time-Series Classification

    Directory of Open Access Journals (Sweden)

    Ting Wang

    2014-01-01

    Full Text Available Eye state identification is a kind of common time-series classification problem which is also a hot spot in recent research. Electroencephalography (EEG is widely used in eye state classification to detect human's cognition state. Previous research has validated the feasibility of machine learning and statistical approaches for EEG eye state classification. This paper aims to propose a novel approach for EEG eye state identification using incremental attribute learning (IAL based on neural networks. IAL is a novel machine learning strategy which gradually imports and trains features one by one. Previous studies have verified that such an approach is applicable for solving a number of pattern recognition problems. However, in these previous works, little research on IAL focused on its application to time-series problems. Therefore, it is still unknown whether IAL can be employed to cope with time-series problems like EEG eye state classification. Experimental results in this study demonstrates that, with proper feature extraction and feature ordering, IAL can not only efficiently cope with time-series classification problems, but also exhibit better classification performance in terms of classification error rates in comparison with conventional and some other approaches.

  9. Digital modulation classification using multi-layer perceptron and time-frequency features

    Institute of Scientific and Technical Information of China (English)

    Yuan Ye; Mei Wenbo

    2007-01-01

    Considering that real communication signals corrupted by noise are generally nonstationary, and time-frequency distributions are especially suitable for the analysis of nonstationary signals, time-frequency distributions are introduced for the modulation classification of communication signals.The extracted time-frequency features have good classification information, and they are insensitive to signal to noise ratio (SNR) variation.According to good classification by the correct rate of a neural network classifier, a multilayer perceptron (MLP) classifier with better generalization, as well as, addition of time-frequency features set for classifying six different modulation types has been proposed.Computer simulations show that the MLP classifier outperforms the decision-theoretic classifier at low SNRs, and the classification experiments for real MPSK signals verify engineering significance of the MLP classifier.

  10. On Machine-Learned Classification of Variable Stars with Sparse and Noisy Time-Series Data

    CERN Document Server

    Richards, Joseph W; Butler, Nathaniel R; Bloom, Joshua S; Brewer, John M; Crellin-Quick, Arien; Higgins, Justin; Kennedy, Rachel; Rischard, Maxime

    2011-01-01

    With the coming data deluge from synoptic surveys, there is a growing need for frameworks that can quickly and automatically produce calibrated classification probabilities for newly-observed variables based on a small number of time-series measurements. In this paper, we introduce a methodology for variable-star classification, drawing from modern machine-learning techniques. We describe how to homogenize the information gleaned from light curves by selection and computation of real-numbered metrics ("feature"), detail methods to robustly estimate periodic light-curve features, introduce tree-ensemble methods for accurate variable star classification, and show how to rigorously evaluate the classification results using cross validation. On a 25-class data set of 1542 well-studied variable stars, we achieve a 22.8% overall classification error using the random forest classifier; this represents a 24% improvement over the best previous classifier on these data. This methodology is effective for identifying sam...

  11. Optimal classification for time-course gene expression data using functional data analysis.

    Science.gov (United States)

    Song, Joon Jin; Deng, Weiguo; Lee, Ho-Jin; Kwon, Deukwoo

    2008-12-01

    Classification problems have received considerable attention in biological and medical applications. In particular, classification methods combining to microarray technology play an important role in diagnosing and predicting disease, such as cancer, in medical research. Primary objective in classification is to build an optimal classifier based on the training sample in order to predict unknown class in the test sample. In this paper, we propose a unified approach for optimal gene classification with conjunction with functional principal component analysis (FPCA) in functional data analysis (FNDA) framework to classify time-course gene expression profiles based on information from the patterns. To derive an optimal classifier in FNDA, we also propose to find optimal number of bases in the smoothing step and functional principal components in FPCA using a cross-validation technique, and compare the performance of some popular classification techniques in the proposed setting. We illustrate the propose method with a simulation study and a real world data analysis. PMID:18755633

  12. Classification of Croplands Through Fusion of Optical and SAR Time Series Data

    Science.gov (United States)

    Park, S.; Im, J.

    2016-06-01

    Many satellite sensors including Landsat series have been extensively used for land cover classification. Studies have been conducted to mitigate classification problems associated with the use of single data (e.g., such as cloud contamination) through multi-sensor data fusion and the use of time series data. This study investigated two areas with different environment and climate conditions: one in South Korea and the other in US. Cropland classification was conducted by using multi-temporal Landsat 5, Radarsat-1 and digital elevation models (DEM) based on two machine learning approaches (i.e., random forest and support vector machines). Seven classification scenarios were examined and evaluated through accuracy assessment. Results show that SVM produced the best performance (overall accuracy of 93.87%) when using all temporal and spectral data as input variables. Normalized Difference Water Index (NDWI), SAR backscattering, and Normalized Difference Vegetation Index (NDVI) were identified as more contributing variables than the others for cropland classification.

  13. 28 CFR 542.18 - Response time.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Response time. 542.18 Section 542.18... REMEDY Administrative Remedy Program § 542.18 Response time. If accepted, a Request or Appeal is... later than the third calendar day after filing. If the time period for response to a Request or...

  14. ARMA modelled time-series classification for structural health monitoring of civil infrastructure

    Science.gov (United States)

    Peter Carden, E.; Brownjohn, James M. W.

    2008-02-01

    Structural health monitoring (SHM) is the subject of a great deal of ongoing research leading to the capability that reliable remote monitoring of civil infrastructure would allow a shift from schedule-based to condition-based maintenance strategies. The first stage in such a system would be the indication of an extraordinary change in the structure's behaviour. A statistical classification algorithm is presented here which is based on analysis of a structure's response in the time domain. The time-series responses are fitted with Autoregressive Moving Average (ARMA) models and the ARMA coefficients are fed to the classifier. The classifier is capable of learning in an unsupervised manner and of forming new classes when the structural response exhibits change. The approach is demonstrated with experimental data from the IASC-ASCE benchmark four-storey frame structure, the Z24 bridge and the Malaysia-Singapore Second Link bridge. The classifier is found to be capable of identifying structural change in all cases and of forming distinct classes corresponding to different structural states in most cases.

  15. Land Cover Classification of Landsat Data with Phenological Features Extracted from Time Series MODIS NDVI Data

    OpenAIRE

    Kun Jia; Shunlin Liang; Xiangqin Wei; Yunjun Yao; Yingru Su; Bo Jiang; Xiaoxia Wang

    2014-01-01

    Temporal-related features are important for improving land cover classification accuracy using remote sensing data. This study investigated the efficacy of phenological features extracted from time series MODIS Normalized Difference Vegetation Index (NDVI) data in improving the land cover classification accuracy of Landsat data. The MODIS NDVI data were first fused with Landsat data via the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) algorithm to obtain NDVI data at the La...

  16. Learning a Mahalanobis Distance-Based Dynamic Time Warping Measure for Multivariate Time Series Classification.

    Science.gov (United States)

    Mei, Jiangyuan; Liu, Meizhu; Wang, Yuan-Fang; Gao, Huijun

    2016-06-01

    Multivariate time series (MTS) datasets broadly exist in numerous fields, including health care, multimedia, finance, and biometrics. How to classify MTS accurately has become a hot research topic since it is an important element in many computer vision and pattern recognition applications. In this paper, we propose a Mahalanobis distance-based dynamic time warping (DTW) measure for MTS classification. The Mahalanobis distance builds an accurate relationship between each variable and its corresponding category. It is utilized to calculate the local distance between vectors in MTS. Then we use DTW to align those MTS which are out of synchronization or with different lengths. After that, how to learn an accurate Mahalanobis distance function becomes another key problem. This paper establishes a LogDet divergence-based metric learning with triplet constraint model which can learn Mahalanobis matrix with high precision and robustness. Furthermore, the proposed method is applied on nine MTS datasets selected from the University of California, Irvine machine learning repository and Robert T. Olszewski's homepage, and the results demonstrate the improved performance of the proposed approach. PMID:25966490

  17. Towards a classification approach using meta-biclustering: impact of discretization in the analysis of expression time series.

    Science.gov (United States)

    Carreiro, André V; Ferreira, Artur J; Figueiredo, Mário A T; Madeira, Sara C

    2012-01-01

    Biclustering has been recognized as a remarkably effective method for discovering local temporal expression patterns and unraveling potential regulatory mechanisms, essential to understanding complex biomedical processes, such as disease progression and drug response. In this work, we propose a classification approach based on meta-biclusters (a set of similar biclusters) applied to prognostic prediction. We use real clinical expression time series to predict the response of patients with multiple sclerosis to treatment with Interferon-β. As compared to previous approaches, the main advantages of this strategy are the interpretability of the results and the reduction of data dimensionality, due to biclustering. This would allow the identification of the genes and time points which are most promising for explaining different types of response profiles, according to clinical knowledge. We assess the impact of different unsupervised and supervised discretization techniques on the classification accuracy. The experimental results show that, in many cases, the use of these discretization methods improves the classification accuracy, as compared to the use of the original features. PMID:22829578

  18. Real-time, resource-constrained object classification on a micro-air vehicle

    Science.gov (United States)

    Buck, Louis; Ray, Laura

    2013-12-01

    A real-time embedded object classification algorithm is developed through the novel combination of binary feature descriptors, a bag-of-visual-words object model and the cortico-striatal loop (CSL) learning algorithm. The BRIEF, ORB and FREAK binary descriptors are tested and compared to SIFT descriptors with regard to their respective classification accuracies, execution times, and memory requirements when used with CSL on a 12.6 g ARM Cortex embedded processor running at 800 MHz. Additionally, the effect of x2 feature mapping and opponent-color representations used with these descriptors is examined. These tests are performed on four data sets of varying sizes and difficulty, and the BRIEF descriptor is found to yield the best combination of speed and classification accuracy. Its use with CSL achieves accuracies between 67% and 95% of those achieved with SIFT descriptors and allows for the embedded classification of a 128x192 pixel image in 0.15 seconds, 60 times faster than classification with SIFT. X2 mapping is found to provide substantial improvements in classification accuracy for all of the descriptors at little cost, while opponent-color descriptors are offer accuracy improvements only on colorful datasets.

  19. Automated condition classification of a reciprocating compressor using time frequency analysis and an artificial neural network

    Science.gov (United States)

    Lin, Yih-Hwang; Wu, Hsien-Chang; Wu, Chung-Yung

    2006-12-01

    The purpose of this study is to develop an automated system for condition classification of a reciprocating compressor. Various time-frequency analysis techniques will be examined for decomposition of the vibration signals. Because a time-frequency distribution is a 3D data map, data reduction is indispensable for subsequent analysis. The extraction of the system characteristics using three indices, namely the time index, frequency index, and amplitude index, will be presented and examined for their applicability. The probability neural network is applied for automated condition classification using a combination of the three indices. The study reveals that a proper choice of the index combination and the time-frequency band can provide excellent classification accuracy for the machinery conditions examined in this work.

  20. Time Series Classification by Class-Specific Mahalanobis Distance Measures

    OpenAIRE

    Prekopcsák, Zoltán; Lemire, Daniel

    2010-01-01

    To classify time series by nearest neighbors, we need to specify or learn one or several distance measures. We consider variations of the Mahalanobis distance measures which rely on the inverse covariance matrix of the data. Unfortunately --- for time series data --- the covariance matrix has often low rank. To alleviate this problem we can either use a pseudoinverse, covariance shrinking or limit the matrix to its diagonal. We review these alternatives and benchmark them against competitive ...

  1. Classification of scalar and dyadic nonlocal optical response models

    DEFF Research Database (Denmark)

    Wubs, Martijn

    2015-01-01

    Nonlocal optical response is one of the emerging effects on the nanoscale for particles made of metals or doped semiconductors. Here we classify and compare both scalar and tensorial nonlocal response models. In the latter case the nonlocality can stem from either the longitudinal response, the...... hydrodynamic Drude model and generalized nonlocal optical response theory, follow this phenomenological description. We find considerable differences, for example that nonlocal response functions, in contrast to simple distributions, assume negative and complex values. Moreover, nonlocal response regularizes...... some but not all diverging optical near fields. We identify the scalar model that comes closest to the hydrodynamic model. Interestingly, for the hydrodynamic Drude model we find that actually only one third (1/3) of the free-electron response is smeared out nonlocally. In that sense, nonlocal response...

  2. Recognition of chemical compounds in contaminated water using time-dependent multiple dose cellular responses

    International Nuclear Information System (INIS)

    Highlights: ► Dose- and time-dependent cellular responses are used to evaluate the cytotoxicity. ► The CI can reflect the cell number, cell viability, morphological change, etc. ► The CSVID can capture the dynamic information after cells exposed to toxins. ► The multi-class classification can distinguish the compounds using multi-doses. ► The majority vote strategy (fingerprint) can improve the classification accuracy. - Abstract: An early determination of toxicant compounds of water contaminations can gain critical time to protect citizens’ health and save substantial amounts of medical costs. To determine toxins in real time, a multi-dose classification algorithm using cellular state variable identification (CSVID) is developed in this paper. First, the dynamic cytotoxicity response profiles of living cells are measured using a real-time cell electronic sensing (RT-CES) system. Changes in cell number expressed as cell index (CI) are recorded on-line as time series. Then CSVID, which reflects the cell killing, cell lysis and certain cellular pathological changes, is extracted from those dynamic cellular responses. Finally, a support vector machine (SVM) algorithm based on CSVID is employed to classify chemical compounds and determine their analogous cellular response pathway. In order to increase the classification accuracy, a majority vote of the class labels is also proposed. Several validation studies demonstrate that CSVID-based classification algorithm has great potential in distinguishing the cytotoxicity response of the cells in the presence of toxins.

  3. Object-Based Crop Classification with Landsat-MODIS Enhanced Time-Series Data

    Directory of Open Access Journals (Sweden)

    Qingting Li

    2015-12-01

    Full Text Available Cropland mapping via remote sensing can provide crucial information for agri-ecological studies. Time series of remote sensing imagery is particularly useful for agricultural land classification. This study investigated the synergistic use of feature selection, Object-Based Image Analysis (OBIA segmentation and decision tree classification for cropland mapping using a finer temporal-resolution Landsat-MODIS Enhanced time series in 2007. The enhanced time series extracted 26 layers of Normalized Difference Vegetation Index (NDVI and five NDVI Time Series Indices (TSI in a subset of agricultural land of Southwest Missouri. A feature selection procedure using the Stepwise Discriminant Analysis (SDA was performed, and 10 optimal features were selected as input data for OBIA segmentation, with an optimal scale parameter obtained by quantification assessment of topological and geometric object differences. Using the segmented metrics in a decision tree classifier, an overall classification accuracy of 90.87% was achieved. Our study highlights the advantage of OBIA segmentation and classification in reducing noise from in-field heterogeneity and spectral variation. The crop classification map produced at 30 m resolution provides spatial distributions of annual and perennial crops, which are valuable for agricultural monitoring and environmental assessment studies.

  4. Unsupervised action classification using space-time link analysis

    DEFF Research Database (Denmark)

    Liu, Haowei; Feris, Rogerio; Krüger, Volker;

    2010-01-01

    In this paper we address the problem of unsupervised discovery of action classes in video data. Different from all existing methods thus far proposed for this task, we present a space-time link analysis approach which matches the performance of traditional unsupervised action categorization metho...

  5. Electron Neutrino Classification in Liquid Argon Time Projection Chamber Detector

    OpenAIRE

    Płoński, Piotr; Stefan, Dorota; Sulej, Robert; Zaremba, Krzysztof

    2015-01-01

    Neutrinos are one of the least known elementary particles. The detection of neutrinos is an extremely difficult task since they are affected only by weak sub-atomic force or gravity. Therefore large detectors are constructed to reveal neutrino's properties. Among them the Liquid Argon Time Projection Chamber (LAr-TPC) detectors provide excellent imaging and particle identification ability for studying neutrinos. The computerized methods for automatic reconstruction and identification of parti...

  6. Real-time event classification in field sport videos

    OpenAIRE

    Kapela, Rafal; Świetlicka, Aleksandra; Rybarczyk, Andrzej; Kolanowski, Krzysztof; O''Connor, Noel E.

    2015-01-01

    The paper presents a novel approach to real-time event detection in sports broadcasts. We present how the same underlying audio-visual feature extraction algorithm based on new global image descriptors is robust across a range of different sports alleviating the need to tailor it to a particular sport. In addition, we propose and evaluate three different classifiers in order to detect events using these features: a feed-forward neural network, an Elman neural network and a decision tree. Each...

  7. Land Cover Classification of Landsat Data with Phenological Features Extracted from Time Series MODIS NDVI Data

    Directory of Open Access Journals (Sweden)

    Kun Jia

    2014-11-01

    Full Text Available Temporal-related features are important for improving land cover classification accuracy using remote sensing data. This study investigated the efficacy of phenological features extracted from time series MODIS Normalized Difference Vegetation Index (NDVI data in improving the land cover classification accuracy of Landsat data. The MODIS NDVI data were first fused with Landsat data via the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM algorithm to obtain NDVI data at the Landsat spatial resolution. Next, phenological features, including the beginning and ending dates of the growing season, the length of the growing season, seasonal amplitude, and the maximum fitted NDVI value, were extracted from the fused time series NDVI data using the TIMESAT tool. The extracted data were integrated with the spectral data of the Landsat data to improve classification accuracy using a maximum likelihood classifier (MLC and support vector machine (SVM classifier. The results indicated that phenological features had a statistically significant effect on improving the land cover classification accuracy of single Landsat data (an approximately 3% increase in overall classification accuracy, especially for vegetation type discrimination. However, the phenological features did not improve on statistical measures including the maximum, the minimum, the mean, and the standard deviation values of the time series NDVI dataset, especially for human-managed vegetation types. Regarding different classifiers, SVM could achieve better classification accuracy than the traditional MLC classifier, but the improvement in accuracy obtained using advanced classifiers was inferior to that achieved by involving the temporally derived features for land cover classification.

  8. A Near Real-time IP Traffic Classification Using Machine Learning

    Directory of Open Access Journals (Sweden)

    Kuldeep Singh

    2013-02-01

    Full Text Available With drastic increase in internet traffic over last few years due to increase in number of internet users, IP traffic classification has gained significant importance for research community as well as various internet service providers for optimization of their network performance and for governmental intelligence organizations. Today, traditional IP traffic classification techniques such as port number and payload based direct packet inspection techniques are rarely used because of use of dynamic port number instead of well-known port number in packet headers and various cryptographic techniques which inhibit inspection of packet payload. Current trends are use of machine learning (ML techniques for IP traffic classification. In this research paper, a real time internet traffic dataset has been developed using packet capturing tool for 2 second packet capturing duration and other datasets have been developed by reducing number of features of 2 second duration dataset using Correlation and Consistency based Feature Selection (FS Algorithms. Then, five ML algorithms MLP, RBF, C4.5, Bayes Net and Naïve Bayes are employed for IP traffic classification with these datasets. This experimental analysis shows that Bayes Net is an effective ML technique for near real time and online IP traffic classification with reduction in packet capture duration and reduction in number of features characterizing each application sample with Correlation based FS Algorithm.

  9. Combining Blink, Pupil, and Response Time Measures in a Concealed Knowledge Test

    Directory of Open Access Journals (Sweden)

    Travis eSeymour

    2013-02-01

    Full Text Available The response time (RT based Concealed Knowledge Test (CKT has been shown to accurately detect participants’ knowledge of mock-crime related information. Tests based on ocular measures such as pupil size and blink rate have sometimes resulted in poor classification, or lacked detailed classification analyses. The present study examines the fitness of multiple pupil and blink related responses in the CKT paradigm. To maximize classification efficiency, participants’ concealed knowledge was assessed using both individual test measures and combinations of test measures. Results show that individual pupil-size, pupil-slope, and pre-response blink-rate measures produce efficient classifications. Combining pupil and blink measures yielded more accuracy classifications than individual ocular measures. Although RT-based tests proved efficient, combining RT with ocular measures had little incremental benefit. It is argued that covertly assessing ocular measures during RT-based tests may guard against effective countermeasure use in applied settings. A compound classification procedure was used to categorize individual participants and yielded high hit rates and low false-alarm rates without the need for adjustments between test paradigms or subject populations. We conclude that with appropriate test paradigms and classification analyses, ocular measures may prove as effective as other indices, though additional research is needed.

  10. Predict or classify: The deceptive role of time-locking in brain signal classification

    Science.gov (United States)

    Rusconi, Marco; Valleriani, Angelo

    2016-01-01

    Several experimental studies claim to be able to predict the outcome of simple decisions from brain signals measured before subjects are aware of their decision. Often, these studies use multivariate pattern recognition methods with the underlying assumption that the ability to classify the brain signal is equivalent to predict the decision itself. Here we show instead that it is possible to correctly classify a signal even if it does not contain any predictive information about the decision. We first define a simple stochastic model that mimics the random decision process between two equivalent alternatives, and generate a large number of independent trials that contain no choice-predictive information. The trials are first time-locked to the time point of the final event and then classified using standard machine-learning techniques. The resulting classification accuracy is above chance level long before the time point of time-locking. We then analyze the same trials using information theory. We demonstrate that the high classification accuracy is a consequence of time-locking and that its time behavior is simply related to the large relaxation time of the process. We conclude that when time-locking is a crucial step in the analysis of neural activity patterns, both the emergence and the timing of the classification accuracy are affected by structural properties of the network that generates the signal. PMID:27320688

  11. Aircraft Target Classification Based on Correlation Features from Time-domain Echoes

    Directory of Open Access Journals (Sweden)

    Du Lan

    2015-12-01

    Full Text Available This paper reports the classification of helicopters, propeller-driven aircraft, and turbojet based on differences in their time-domain modulation periods using a conventional radar system. First, we determine the modulation periods of their time-domain echoes. Then, based on the differences in the time-domain modulation periods, we propose a method for the extraction of time-domain correlation features. Finally, based on the simulated and measured data, via a support vector machine classifier, it is proved that the time-domain correlation features can yield the good classification performance, even with the relatively low pulse repetition frequency, which may induce the ambiguity in Doppler-frequency domain.

  12. A Novel Land Cover Classification Map Based on a MODIS Time-Series in Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Linlin Lu

    2014-04-01

    Full Text Available Accurate mapping of land cover on a regional scale is useful for climate and environmental modeling. In this study, we present a novel land cover classification product based on spectral and phenological information for the Xinjiang Uygur Autonomous Region (XUAR in China. The product is derived at a 500 m spatial resolution using an innovative approach employing moderate resolution imaging spectroradiometer (MODIS surface reflectance and the enhanced vegetation index (EVI time series. The classification results capture regional scale land cover patterns and small-scale phenomena. By applying a regionally specified classification scheme, an extensive collection of training data, and regionally tuned data processing, the quality and consistency of the phenological maps are significantly improved. With the ability to provide an updated land cover product considering the heterogenic environmental and climatic conditions, the novel land cover map is valuable for research related to environmental change in this region.

  13. Non-Hodgkin lymphoma response evaluation with MRI texture classification

    OpenAIRE

    Heinonen Tomi T; Saarinen Tuomas O; Pertovaara Hannu; Luukkaala Tiina; Harrison Lara CV; Järvenpää Ritva; Soimakallio Seppo; Kellokumpu-Lehtinen Pirkko-Liisa I; Eskola Hannu J; Dastidar Prasun

    2009-01-01

    Abstract Background To show magnetic resonance imaging (MRI) texture appearance change in non-Hodgkin lymphoma (NHL) during treatment with response controlled by quantitative volume analysis. Methods A total of 19 patients having NHL with an evaluable lymphoma lesion were scanned at three imaging timepoints with 1.5T device during clinical treatment evaluation. Texture characteristics of images were analyzed and classified with MaZda application and statistical tests. Results NHL tissue MRI t...

  14. Validation of the AECL response time tester

    International Nuclear Information System (INIS)

    The response time of a nuclear safety (trip) channel is an important safety parameter, and an ISA standard requires nuclear operators to measure the response times of their trip instrumentation. As a major aid to facilitate this measurement, AECL (Chalk River) has designed and built a Response Time Tester (RTT) for pressure and differential-pressure transmitters. The RTT is mostly automated for ease of use, is self-checking, and complies with the requirements of ISA Standard, S67.06. The RTT was first checked for repeatability and self-consistency. Secondly, it was successfully validated against an independent measurement, namely the transfer function as measured using the natural in-service noise. This validation was done using two Bailey transmitters, which had the unfortunate property of having their response times as functions of the testing conditions. In all instances, after correcting for this Bailey nonlinearity, the RTT performance met its accuracy specification of ±(5% + 5 ms). (author)

  15. Real-time classification of humans versus animals using profiling sensors and hidden Markov tree model

    Science.gov (United States)

    Hossen, Jakir; Jacobs, Eddie L.; Chari, Srikant

    2015-07-01

    Linear pyroelectric array sensors have enabled useful classifications of objects such as humans and animals to be performed with relatively low-cost hardware in border and perimeter security applications. Ongoing research has sought to improve the performance of these sensors through signal processing algorithms. In the research presented here, we introduce the use of hidden Markov tree (HMT) models for object recognition in images generated by linear pyroelectric sensors. HMTs are trained to statistically model the wavelet features of individual objects through an expectation-maximization learning process. Human versus animal classification for a test object is made by evaluating its wavelet features against the trained HMTs using the maximum-likelihood criterion. The classification performance of this approach is compared to two other techniques; a texture, shape, and spectral component features (TSSF) based classifier and a speeded-up robust feature (SURF) classifier. The evaluation indicates that among the three techniques, the wavelet-based HMT model works well, is robust, and has improved classification performance compared to a SURF-based algorithm in equivalent computation time. When compared to the TSSF-based classifier, the HMT model has a slightly degraded performance but almost an order of magnitude improvement in computation time enabling real-time implementation.

  16. Classification of Time Series Gene Expression in Clinical Studies via Integration of Biological Network

    OpenAIRE

    Liwei Qian; Haoran Zheng; Hong Zhou; Ruibin Qin; Jinlong Li

    2013-01-01

    The increasing availability of time series expression datasets, although promising, raises a number of new computational challenges. Accordingly, the development of suitable classification methods to make reliable and sound predictions is becoming a pressing issue. We propose, here, a new method to classify time series gene expression via integration of biological networks. We evaluated our approach on 2 different datasets and showed that the use of a hidden Markov model/Gaussian mixture mode...

  17. Joint Time-Frequency-Space Classification of EEG in a Brain-Computer Interface Application

    Directory of Open Access Journals (Sweden)

    Molina Gary N Garcia

    2003-01-01

    Full Text Available Brain-computer interface is a growing field of interest in human-computer interaction with diverse applications ranging from medicine to entertainment. In this paper, we present a system which allows for classification of mental tasks based on a joint time-frequency-space decorrelation, in which mental tasks are measured via electroencephalogram (EEG signals. The efficiency of this approach was evaluated by means of real-time experimentations on two subjects performing three different mental tasks. To do so, a number of protocols for visualization, as well as training with and without feedback, were also developed. Obtained results show that it is possible to obtain good classification of simple mental tasks, in view of command and control, after a relatively small amount of training, with accuracies around 80%, and in real time.

  18. Time-Frequency Signal Processing Based on Fractional Fourier Transform in Passive Sonar Classification

    Directory of Open Access Journals (Sweden)

    Vahid Bagheri

    2014-11-01

    Full Text Available This paper introduce a new data SONAR classification method based on Short-Time Fractional Fourier Transform (STFrFT analysis. The passive SONAR system receives the acoustic signals radiated by vessels and attempts to categorize them as a function of the similarities between vessels of the same class.Here, a time-frequency processing and feature extraction method is developed in order to improve the performance of a feedforwardneural network, which is used to classify five classes of vessels.Processing of time-varying signals in fractional fourier domain allows us to estimate the signal with higher concentration than conventional fourier domain, making the technique robust against additive noise, maintaining same computational complexity. With the purpose of dimension reduction and classification improvement, we use Linear Discriminant Analysis (LDA technique. The feasibility of the proposed technique (STFrFTLDA has been tested experimentally using a real database. The experimental results show the superiority of the proposed method

  19. Refining Time-Activity Classification of Human Subjects Using the Global Positioning System

    Science.gov (United States)

    Hu, Maogui; Li, Wei; Li, Lianfa; Houston, Douglas; Wu, Jun

    2016-01-01

    Background Detailed spatial location information is important in accurately estimating personal exposure to air pollution. Global Position System (GPS) has been widely used in tracking personal paths and activities. Previous researchers have developed time-activity classification models based on GPS data, most of them were developed for specific regions. An adaptive model for time-location classification can be widely applied to air pollution studies that use GPS to track individual level time-activity patterns. Methods Time-activity data were collected for seven days using GPS loggers and accelerometers from thirteen adult participants from Southern California under free living conditions. We developed an automated model based on random forests to classify major time-activity patterns (i.e. indoor, outdoor-static, outdoor-walking, and in-vehicle travel). Sensitivity analysis was conducted to examine the contribution of the accelerometer data and the supplemental spatial data (i.e. roadway and tax parcel data) to the accuracy of time-activity classification. Our model was evaluated using both leave-one-fold-out and leave-one-subject-out methods. Results Maximum speeds in averaging time intervals of 7 and 5 minutes, and distance to primary highways with limited access were found to be the three most important variables in the classification model. Leave-one-fold-out cross-validation showed an overall accuracy of 99.71%. Sensitivities varied from 84.62% (outdoor walking) to 99.90% (indoor). Specificities varied from 96.33% (indoor) to 99.98% (outdoor static). The exclusion of accelerometer and ambient light sensor variables caused a slight loss in sensitivity for outdoor walking, but little loss in overall accuracy. However, leave-one-subject-out cross-validation showed considerable loss in sensitivity for outdoor static and outdoor walking conditions. Conclusions The random forests classification model can achieve high accuracy for the four major time

  20. Refining Time-Activity Classification of Human Subjects Using the Global Positioning System.

    Directory of Open Access Journals (Sweden)

    Maogui Hu

    Full Text Available Detailed spatial location information is important in accurately estimating personal exposure to air pollution. Global Position System (GPS has been widely used in tracking personal paths and activities. Previous researchers have developed time-activity classification models based on GPS data, most of them were developed for specific regions. An adaptive model for time-location classification can be widely applied to air pollution studies that use GPS to track individual level time-activity patterns.Time-activity data were collected for seven days using GPS loggers and accelerometers from thirteen adult participants from Southern California under free living conditions. We developed an automated model based on random forests to classify major time-activity patterns (i.e. indoor, outdoor-static, outdoor-walking, and in-vehicle travel. Sensitivity analysis was conducted to examine the contribution of the accelerometer data and the supplemental spatial data (i.e. roadway and tax parcel data to the accuracy of time-activity classification. Our model was evaluated using both leave-one-fold-out and leave-one-subject-out methods.Maximum speeds in averaging time intervals of 7 and 5 minutes, and distance to primary highways with limited access were found to be the three most important variables in the classification model. Leave-one-fold-out cross-validation showed an overall accuracy of 99.71%. Sensitivities varied from 84.62% (outdoor walking to 99.90% (indoor. Specificities varied from 96.33% (indoor to 99.98% (outdoor static. The exclusion of accelerometer and ambient light sensor variables caused a slight loss in sensitivity for outdoor walking, but little loss in overall accuracy. However, leave-one-subject-out cross-validation showed considerable loss in sensitivity for outdoor static and outdoor walking conditions.The random forests classification model can achieve high accuracy for the four major time-activity categories. The model also

  1. A Joint Time-Frequency and Matrix Decomposition Feature Extraction Methodology for Pathological Voice Classification

    OpenAIRE

    Behnaz Ghoraani; Sridhar Krishnan

    2009-01-01

    The number of people affected by speech problems is increasing as the modern world places increasing demands on the human voice via mobile telephones, voice recognition software, and interpersonal verbal communications. In this paper, we propose a novel methodology for automatic pattern classification of pathological voices. The main contribution of this paper is extraction of meaningful and unique features using Adaptive time-frequency distribution (TFD) and nonnegative matrix factorization ...

  2. A Novel Land Cover Classification Map Based on a MODIS Time-Series in Xinjiang, China

    OpenAIRE

    Linlin Lu; Claudia Kuenzer; Huadong Guo; Qingting Li; Tengfei Long; Xinwu Li

    2014-01-01

    Accurate mapping of land cover on a regional scale is useful for climate and environmental modeling. In this study, we present a novel land cover classification product based on spectral and phenological information for the Xinjiang Uygur Autonomous Region (XUAR) in China. The product is derived at a 500 m spatial resolution using an innovative approach employing moderate resolution imaging spectroradiometer (MODIS) surface reflectance and the enhanced vegetation index (EVI) time series. The ...

  3. ON MACHINE-LEARNED CLASSIFICATION OF VARIABLE STARS WITH SPARSE AND NOISY TIME-SERIES DATA

    International Nuclear Information System (INIS)

    With the coming data deluge from synoptic surveys, there is a need for frameworks that can quickly and automatically produce calibrated classification probabilities for newly observed variables based on small numbers of time-series measurements. In this paper, we introduce a methodology for variable-star classification, drawing from modern machine-learning techniques. We describe how to homogenize the information gleaned from light curves by selection and computation of real-numbered metrics (features), detail methods to robustly estimate periodic features, introduce tree-ensemble methods for accurate variable-star classification, and show how to rigorously evaluate a classifier using cross validation. On a 25-class data set of 1542 well-studied variable stars, we achieve a 22.8% error rate using the random forest (RF) classifier; this represents a 24% improvement over the best previous classifier on these data. This methodology is effective for identifying samples of specific science classes: for pulsational variables used in Milky Way tomography we obtain a discovery efficiency of 98.2% and for eclipsing systems we find an efficiency of 99.1%, both at 95% purity. The RF classifier is superior to other methods in terms of accuracy, speed, and relative immunity to irrelevant features; the RF can also be used to estimate the importance of each feature in classification. Additionally, we present the first astronomical use of hierarchical classification methods to incorporate a known class taxonomy in the classifier, which reduces the catastrophic error rate from 8% to 7.8%. Excluding low-amplitude sources, the overall error rate improves to 14%, with a catastrophic error rate of 3.5%.

  4. Time Domain Response of the ARIANNA Detector

    CERN Document Server

    Barwick, S W; Besson, D Z; Hanson, J C; Klein, S R; Kleinfelder, S A; Piasecki, M; Ratzlaff, K; Reed, C; Roumi, M; Stezelberger, T; Tatar, J; Walker, J; Young, R; Zou, L

    2014-01-01

    The Antarctic Ross Ice Shelf Antenna Neutrino Array (ARIANNA) is a high-energy neutrino detector designed to record the Askaryan electric field signature of cosmogenic neutrino interactions in ice. To understand the inherent radio-frequency (RF) neutrino signature, the time-domain response of the ARIANNA RF receiver must be measured. ARIANNA uses Create CLP5130-2N log-periodic dipole arrays (LPDAs). The associated effective height operator converts incident electric fields to voltage waveforms at the LDPA terminals. The effective height versus time and incident angle was measured, along with the associated response of the ARIANNA RF amplifier. The results are verified by correlating to field measurements in air and ice, using oscilloscopes. Finally, theoretical models for the Askaryan electric field are combined with the detector response to predict the neutrino signature.

  5. 29 CFR 1610.9 - Responses: timing.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Responses: timing. 1610.9 Section 1610.9 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION AVAILABILITY OF RECORDS Production or... reasonably be expected to pose an imminent threat to the life or physical safety of an individual; or...

  6. RESPONSE TIMES IN DECISION-MAKING TASKS.

    Science.gov (United States)

    DAGLE, EVERETT F.; AND OTHERS

    THE HUMAN OPERATOR AFFECTS TOTAL PERFORMANCE OF SEMI-AUTOMATED SYSTEMS, BUT LITTLE IS KNOWN ABOUT HIS SOURCES OF ERROR, PARTICULARLY WITH RESPECT TO RESPONSE TIME. UNDER CONTROLLED LABORATORY CONDITIONS, 37 FRESHMEN AND SOPHOMORE GIRLS ATTENDING JUNIOR COLLEGE WERE ASKED TO GUESS A SERIES OF RANDOM NUMBERS GENERATED BY AN ELECTROMECHANICAL SYSTEM…

  7. Automatic disruption classification based on manifold learning for real-time applications on JET

    International Nuclear Information System (INIS)

    Disruptions remain the biggest threat to the safe operation of tokamaks. To efficiently mitigate the negative effects, it is now considered important not only to predict their occurrence but also to be able to determine, with high probability, the type of disruption about to occur. This paper reports the results obtained using the nonlinear generative topographic map manifold learning technique for the automatic classification of disruption types. It has been tested using an extensive database of JET discharges selected from JET campaigns from C15 (year 2005) up to C27 (year 2009). The success rate of the classification is extremely high, sometimes reaching 100%, and therefore the prospects for the deployment of this tool in real time are very promising. (paper)

  8. Reverberation time in class rooms – Comparison of regulations and classification criteria in the Nordic countries

    DEFF Research Database (Denmark)

    Rasmussen, Birgit; Brunskog, Jonas; Hoffmeyer, Dan

    2012-01-01

    reasons for having such requirements: Improving learning efficiency for pupils and work conditions for teachers and reducing noise levels, thus increasing comfort for everyone. Instead of including acoustic regulatory requirements for schools directly in the building regulations, Iceland, Norway and......Regulatory requirements or guidelines for classroom reverberation time exist in all five Nordic countries and in most of Europe – as well as other acoustic criteria for schools, e.g. concerning airborne and impact sound insulation, facade sound insulation and installation noise. There are several...... Sweden have introduced acoustic quality classes A, B, C and D in national standards with class C referred to as regulatory requirements. These national classification standards are dealing with acoustic classes for several types of buildings. A classification scheme also exists in Finland, but with no...

  9. Motion data classification on the basis of dynamic time warping with a cloud point distance measure

    Science.gov (United States)

    Switonski, Adam; Josinski, Henryk; Zghidi, Hafedh; Wojciechowski, Konrad

    2016-06-01

    The paper deals with the problem of classification of model free motion data. The nearest neighbors classifier which is based on comparison performed by Dynamic Time Warping transform with cloud point distance measure is proposed. The classification utilizes both specific gait features reflected by a movements of subsequent skeleton joints and anthropometric data. To validate proposed approach human gait identification challenge problem is taken into consideration. The motion capture database containing data of 30 different humans collected in Human Motion Laboratory of Polish-Japanese Academy of Information Technology is used. The achieved results are satisfactory, the obtained accuracy of human recognition exceeds 90%. What is more, the applied cloud point distance measure does not depend on calibration process of motion capture system which results in reliable validation.

  10. Recognition of chemical compounds in contaminated water using time-dependent multiple dose cellular responses

    Energy Technology Data Exchange (ETDEWEB)

    Pan, T.H., E-mail: thpan@ujs.edu.cn [School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Department of Chemical and Material Engineering, University of Alberta, Edmonton, Alberta T6G 2G6 (Canada); Huang, B., E-mail: biao.huang@ualberta.ca [Department of Chemical and Material Engineering, University of Alberta, Edmonton, Alberta T6G 2G6 (Canada); Xing, J.Z., E-mail: jzxing@ualberta.ca [Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta T6G 2S2 (Canada); Zhang, W.P., E-mail: weiping.zhang@gov.ab.ca [Alberta Health and Wellness, Edmonton, Alberta T5J 1S6 (Canada); Gabos, S., E-mail: stephan.gabos@gov.ab.ca [Alberta Health and Wellness, Edmonton, Alberta T5J 1S6 (Canada); Chen, J., E-mail: jchen@ece.ualberta.ca [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2S2 (Canada)

    2012-04-29

    Highlights: Black-Right-Pointing-Pointer Dose- and time-dependent cellular responses are used to evaluate the cytotoxicity. Black-Right-Pointing-Pointer The CI can reflect the cell number, cell viability, morphological change, etc. Black-Right-Pointing-Pointer The CSVID can capture the dynamic information after cells exposed to toxins. Black-Right-Pointing-Pointer The multi-class classification can distinguish the compounds using multi-doses. Black-Right-Pointing-Pointer The majority vote strategy (fingerprint) can improve the classification accuracy. - Abstract: An early determination of toxicant compounds of water contaminations can gain critical time to protect citizens' health and save substantial amounts of medical costs. To determine toxins in real time, a multi-dose classification algorithm using cellular state variable identification (CSVID) is developed in this paper. First, the dynamic cytotoxicity response profiles of living cells are measured using a real-time cell electronic sensing (RT-CES) system. Changes in cell number expressed as cell index (CI) are recorded on-line as time series. Then CSVID, which reflects the cell killing, cell lysis and certain cellular pathological changes, is extracted from those dynamic cellular responses. Finally, a support vector machine (SVM) algorithm based on CSVID is employed to classify chemical compounds and determine their analogous cellular response pathway. In order to increase the classification accuracy, a majority vote of the class labels is also proposed. Several validation studies demonstrate that CSVID-based classification algorithm has great potential in distinguishing the cytotoxicity response of the cells in the presence of toxins.

  11. Real-time framework for tensor-based image enhancement for object classification

    Science.gov (United States)

    Cyganek, Bogusław; Smołka, Bogdan

    2016-04-01

    In many practical situations visual pattern recognition is vastly burdened by low quality of input images due to noise, geometrical distortions, as well as low quality of the acquisition hardware. However, although there are techniques of image quality improvements, such as nonlinear filtering, there are only few attempts reported in the literature that try to build these enhancement methods into a complete chain for multi-dimensional object recognition such as color video or hyperspectral images. In this work we propose a joint multilinear signal filtering and classification system built upon the multi-dimensional (tensor) approach. Tensor filtering is performed by the multi-dimensional input signal projection into the tensor subspace spanned by the best-rank tensor decomposition method. On the other hand, object classification is done by construction of the tensor sub-space constructed based on the Higher-Order Singular Value Decomposition method applied to the prototype patters. In the experiments we show that the proposed chain allows high object recognition accuracy in the real-time even from the poor quality prototypes. Even more importantly, the proposed framework allows unified classification of signals of any dimensions, such as color images or video sequences which are exemplars of 3D and 4D tensors, respectively. The paper discussed also some practical issues related to implementation of the key components of the proposed system.

  12. Nonparametric Single-Trial EEG Feature Extraction and Classification of Driver's Cognitive Responses

    Directory of Open Access Journals (Sweden)

    I-Fang Chung

    2008-05-01

    Full Text Available We proposed an electroencephalographic (EEG signal analysis approach to investigate the driver's cognitive response to traffic-light experiments in a virtual-reality-(VR- based simulated driving environment. EEG signals are digitally sampled and then transformed by three different feature extraction methods including nonparametric weighted feature extraction (NWFE, principal component analysis (PCA, and linear discriminant analysis (LDA, which were also used to reduce the feature dimension and project the measured EEG signals to a feature space spanned by their eigenvectors. After that, the mapped data could be classified with fewer features and their classification results were compared by utilizing two different classifiers including k nearest neighbor classification (KNNC and naive bayes classifier (NBC. Experimental data were collected from 6 subjects and the results show that NWFE+NBC gives the best classification accuracy ranging from 71%∼77%, which is over 10%∼24% higher than LDA+KNN1. It also demonstrates the feasibility of detecting and analyzing single-trial EEG signals that represent operators' cognitive states and responses to task events.

  13. Time response measurements of LASL diagnostic detectors

    International Nuclear Information System (INIS)

    The measurement and data analysis techniques developed under the Los Alamos Scientific Laboratory's detector improvement program were used to characterize the time and frequency response of selected LASL Compton, fluor-photodiode (NPD), and fluor-photomultiplier (NPM) diagnostic detectors. Data acquisition procedures and analysis methods presently in use are summarized, and detector time and frequency data obtained using the EG and G/AEC electron linear accelerator fast pulse (approximately 50 psec FWHM) as the incident radiation driving function are presented. (U.S.)

  14. Time Domain Response of the ARIANNA Detector

    OpenAIRE

    Barwick, S. W.; Berg, E. C.; Besson, D. Z.; Hanson, J. C.; Klein, S. R.; Kleinfelder, S. A.; Piasecki, M.; Ratzlaff, K.; Reed, C.; Roumi, M.; Stezelberger, T.; Tatar, J.; Walker, J; Young, R.; Zou, L.

    2014-01-01

    The Antarctic Ross Ice Shelf Antenna Neutrino Array (ARIANNA) is a high-energy neutrino detector designed to record the Askaryan electric field signature of cosmogenic neutrino interactions in ice. To understand the inherent radio-frequency (RF) neutrino signature, the time-domain response of the ARIANNA RF receiver must be measured. ARIANNA uses Create CLP5130-2N log-periodic dipole arrays (LPDAs). The associated effective height operator converts incident electric fields to voltage waveform...

  15. Classification of Hazelnut Kernels by Using Impact Acoustic Time-Frequency Patterns

    Directory of Open Access Journals (Sweden)

    Tom Pearson

    2007-12-01

    Full Text Available Hazelnuts with damaged or cracked shells are more prone to infection with aflatoxin producing molds (Aspergillus flavus. These molds can cause cancer. In this study, we introduce a new approach that separates damaged/cracked hazelnut kernels from good ones by using time-frequency features obtained from impact acoustic signals. The proposed technique requires no prior knowledge of the relevant time and frequency locations. In an offline step, the algorithm adaptively segments impact signals from a training data set in time using local cosine packet analysis and a Kullback-Leibler criterion to assess the discrimination power of different segmentations. In each resulting time segment, the signal is further decomposed into subbands using an undecimated wavelet transform. The most discriminative subbands are selected according to the Euclidean distance between the cumulative probability distributions of the corresponding subband coefficients. The most discriminative subbands are fed into a linear discriminant analysis classifier. In the online classification step, the algorithm simply computes the learned features from the observed signal and feeds them to the linear discriminant analysis (LDA classifier. The algorithm achieved a throughput rate of 45 nuts/s and a classification accuracy of 96% with the 30 most discriminative features, a higher rate than those provided with prior methods.

  16. A study on the development of a real-time intelligent system for ultrasonic flaw classification

    International Nuclear Information System (INIS)

    In spite of significant progress in research on ultrasonic pattern recognition it is not widely used in many practical field inspection in weldments. For the convenience of field application of this methodology, following four key issues have to be suitably addressed; 1) a software where the ultrasonic pattern recognition algorithm is efficiently implemented, 2) a real-time ultrasonic testing system which can capture the digitized ultrasonic flaw signal so the pattern recognition software can be applied in a real-time fashion, 3) database of ultrasonic flaw signals in weldments, which is served as a foundation of the ultrasonic pattern recognition algorithm, and finally, 4) ultrasonic features which should be invariant to operational variables of the ultrasonic test system. Presented here is the recent progress in the development of a real-time ultrasonic flaw classification by the novel combination of followings; an intelligent software for ultrasonic flaw classification in weldments, a computer-base real-time ultrasonic nondestructive evaluation system, database of ultrasonic flaw signals, and invariant ultrasonic features called 'normalized features.'

  17. Predict or classify: The deceptive role of time-locking in brain signal classification

    CERN Document Server

    Rusconi, Marco

    2016-01-01

    Several experimental studies claim to be able to predict the outcome of simple decisions from brain signals measured before subjects are aware of their decision. Often, these studies use multivariate pattern recognition methods with the underlying assumption that the ability to classify the brain signal is equivalent to predict the decision itself. Here we show instead that it is possible to correctly classify a signal even if it does not contain any predictive information about the decision. We first define a simple stochastic model that mimics the random decision process between two equivalent alternatives, and generate a large number of independent trials that contain no choice-predictive information. The trials are first time-locked to the time point of the final event and then classified using standard machine-learning techniques. The resulting classification accuracy is above chance level long before the time point of time-locking. We then analyze the same trials using information theory. We demonstrate...

  18. Proposition of novel classification approach and features for improved real-time arrhythmia monitoring.

    Science.gov (United States)

    Kim, Yoon Jae; Heo, Jeong; Park, Kwang Suk; Kim, Sungwan

    2016-08-01

    Arrhythmia refers to a group of conditions in which the heartbeat is irregular, fast, or slow due to abnormal electrical activity in the heart. Some types of arrhythmia such as ventricular fibrillation may result in cardiac arrest or death. Thus, arrhythmia detection becomes an important issue, and various studies have been conducted. Additionally, an arrhythmia detection algorithm for portable devices such as mobile phones has recently been developed because of increasing interest in e-health care. This paper proposes a novel classification approach and features, which are validated for improved real-time arrhythmia monitoring. The classification approach that was employed for arrhythmia detection is based on the concept of ensemble learning and the Taguchi method and has the advantage of being accurate and computationally efficient. The electrocardiography (ECG) data for arrhythmia detection was obtained from the MIT-BIH Arrhythmia Database (n=48). A novel feature, namely the heart rate variability calculated from 5s segments of ECG, which was not considered previously, was used. The novel classification approach and feature demonstrated arrhythmia detection accuracy of 89.13%. When the same data was classified using the conventional support vector machine (SVM), the obtained accuracy was 91.69%, 88.14%, and 88.74% for Gaussian, linear, and polynomial kernels, respectively. In terms of computation time, the proposed classifier was 5821.7 times faster than conventional SVM. In conclusion, the proposed classifier and feature showed performance comparable to those of previous studies, while the computational complexity and update interval were highly reduced. PMID:27318329

  19. Reedbed monitoring using classification trees and SPOT-5 seasonal time series

    OpenAIRE

    Davranche, Aurélie; Poulin, Brigitte; Lefebvre, Gaëtan

    2010-01-01

    The Rhône river delta (Camargue) in south of France, has lost 40,000 ha of natural areas, including 33,000 ha of wetlands over the last 60 years, following the extension of agriculture, salt exploitation and industry. Reed development and density in Camargue marshes is influenced by physical factors such as salinity, water depth, and water level fluctuations, which have an effect on reflectance spectra. Classification trees applied to time series of SPOT-5 images appear as a powerful and reli...

  20. Aquifer response to recharge-discharge phenomenon: inference from well hydrographs for genetic classification

    Science.gov (United States)

    Mukherjee, Arunangshu; Gupta, Anita; Ray, Ranjan Kumar; Tewari, Dinesh

    2015-05-01

    The continuous groundwater level data emanating from a high-frequency automatic water level recorder installed in a purpose-built piezometer provides a true hydrograph. Analyses of such hydrographs fairly reflect the aquifer character and can be used to draw inference for genetic classification of hard rock aquifers. The signature shape of annual water level fluctuation curve (annual cycle) of a piezometer is due to the specific character of the aquifer and the way it responds to the recharge-discharge phenomenon. The pattern of annual cycle remains identical year after year, although its magnitude may vary with the annual quantum of recharge-discharge. Lithology of the aquifer does not control the shape of the curve. Based on the crest and trough shape, the hard rock aquifers of Peninsular India, where the monsoonal pattern of rainfall occurs, have been classified into genetic groups. It is also found that the nature of the aquifer can be determined by visual comparison of apparent line thickness of the hydrograph, where thin lines denote unconfined aquifer and the apparently thicker lines correspond to confining condition. The response of an aquifer to a pumping event can be identified and separated by its pattern. Thus, the aquifer classification can be automated by adopting the proposed classification scheme.

  1. Real-Time Classification of Complex Patterns Using Spike-Based Learning in Neuromorphic VLSI.

    Science.gov (United States)

    Mitra, S; Fusi, S; Indiveri, G

    2009-02-01

    Real-time classification of patterns of spike trains is a difficult computational problem that both natural and artificial networks of spiking neurons are confronted with. The solution to this problem not only could contribute to understanding the fundamental mechanisms of computation used in the biological brain, but could also lead to efficient hardware implementations of a wide range of applications ranging from autonomous sensory-motor systems to brain-machine interfaces. Here we demonstrate real-time classification of complex patterns of mean firing rates, using a VLSI network of spiking neurons and dynamic synapses which implement a robust spike-driven plasticity mechanism. The learning rule implemented is a supervised one: a teacher signal provides the output neuron with an extra input spike-train during training, in parallel to the spike-trains that represent the input pattern. The teacher signal simply indicates if the neuron should respond to the input pattern with a high rate or with a low one. The learning mechanism modifies the synaptic weights only as long as the current generated by all the stimulated plastic synapses does not match the output desired by the teacher, as in the perceptron learning rule. We describe the implementation of this learning mechanism and present experimental data that demonstrate how the VLSI neural network can learn to classify patterns of neural activities, also in the case in which they are highly correlated. PMID:23853161

  2. Damage classification and estimation in experimental structures using time series analysis and pattern recognition

    Science.gov (United States)

    de Lautour, Oliver R.; Omenzetter, Piotr

    2010-07-01

    Developed for studying long sequences of regularly sampled data, time series analysis methods are being increasingly investigated for the use of Structural Health Monitoring (SHM). In this research, Autoregressive (AR) models were used to fit the acceleration time histories obtained from two experimental structures: a 3-storey bookshelf structure and the ASCE Phase II Experimental SHM Benchmark Structure, in undamaged and limited number of damaged states. The coefficients of the AR models were considered to be damage-sensitive features and used as input into an Artificial Neural Network (ANN). The ANN was trained to classify damage cases or estimate remaining structural stiffness. The results showed that the combination of AR models and ANNs are efficient tools for damage classification and estimation, and perform well using small number of damage-sensitive features and limited sensors.

  3. Neural Networks for Template Matching: Application to Real-Time Classification of the Action Potentials of Real Neurons

    OpenAIRE

    Wong, Yiu-fai; Banik, Jashojiban; Bower, James M.

    1988-01-01

    Much experimental study of real neural networks relies on the proper classification of extracellulary sampled neural signals (i .e. action potentials) recorded from the brains of experimental animals. In most neurophysiology laboratories this classification task is simplified by limiting investigations to single, electrically well-isolated neurons recorded one at a time. However, for those interested in sampling the activities of many single neurons simultaneously, waveform cla...

  4. A Joint Time-Frequency and Matrix Decomposition Feature Extraction Methodology for Pathological Voice Classification

    Science.gov (United States)

    Ghoraani, Behnaz; Krishnan, Sridhar

    2009-12-01

    The number of people affected by speech problems is increasing as the modern world places increasing demands on the human voice via mobile telephones, voice recognition software, and interpersonal verbal communications. In this paper, we propose a novel methodology for automatic pattern classification of pathological voices. The main contribution of this paper is extraction of meaningful and unique features using Adaptive time-frequency distribution (TFD) and nonnegative matrix factorization (NMF). We construct Adaptive TFD as an effective signal analysis domain to dynamically track the nonstationarity in the speech and utilize NMF as a matrix decomposition (MD) technique to quantify the constructed TFD. The proposed method extracts meaningful and unique features from the joint TFD of the speech, and automatically identifies and measures the abnormality of the signal. Depending on the abnormality measure of each signal, we classify the signal into normal or pathological. The proposed method is applied on the Massachusetts Eye and Ear Infirmary (MEEI) voice disorders database which consists of 161 pathological and 51 normal speakers, and an overall classification accuracy of 98.6% was achieved.

  5. A Joint Time-Frequency and Matrix Decomposition Feature Extraction Methodology for Pathological Voice Classification

    Directory of Open Access Journals (Sweden)

    Behnaz Ghoraani

    2009-01-01

    Full Text Available The number of people affected by speech problems is increasing as the modern world places increasing demands on the human voice via mobile telephones, voice recognition software, and interpersonal verbal communications. In this paper, we propose a novel methodology for automatic pattern classification of pathological voices. The main contribution of this paper is extraction of meaningful and unique features using Adaptive time-frequency distribution (TFD and nonnegative matrix factorization (NMF. We construct Adaptive TFD as an effective signal analysis domain to dynamically track the nonstationarity in the speech and utilize NMF as a matrix decomposition (MD technique to quantify the constructed TFD. The proposed method extracts meaningful and unique features from the joint TFD of the speech, and automatically identifies and measures the abnormality of the signal. Depending on the abnormality measure of each signal, we classify the signal into normal or pathological. The proposed method is applied on the Massachusetts Eye and Ear Infirmary (MEEI voice disorders database which consists of 161 pathological and 51 normal speakers, and an overall classification accuracy of 98.6% was achieved.

  6. Automated extraction and classification of time-frequency contours in humpback vocalizations.

    Science.gov (United States)

    Ou, Hui; Au, Whitlow W L; Zurk, Lisa M; Lammers, Marc O

    2013-01-01

    A time-frequency contour extraction and classification algorithm was created to analyze humpback whale vocalizations. The algorithm automatically extracted contours of whale vocalization units by searching for gray-level discontinuities in the spectrogram images. The unit-to-unit similarity was quantified by cross-correlating the contour lines. A library of distinctive humpback units was then generated by applying an unsupervised, cluster-based learning algorithm. The purpose of this study was to provide a fast and automated feature selection tool to describe the vocal signatures of animal groups. This approach could benefit a variety of applications such as species description, identification, and evolution of song structures. The algorithm was tested on humpback whale song data recorded at various locations in Hawaii from 2002 to 2003. Results presented in this paper showed low probability of false alarm (0%-4%) under noisy environments with small boat vessels and snapping shrimp. The classification algorithm was tested on a controlled set of 30 units forming six unit types, and all the units were correctly classified. In a case study on humpback data collected in the Auau Chanel, Hawaii, in 2002, the algorithm extracted 951 units, which were classified into 12 distinctive types. PMID:23297903

  7. The GALEX Time Domain Survey I. Selection and Classification of Over a Thousand UV Variable Sources

    CERN Document Server

    Gezari, S; Forster, K; Neill, J D; Huber, M; Heckman, T; Bianchi, L; Morrissey, P; Neff, S G; Seibert, M; Schiminovich, D; Wyder, T K; Burgett, W S; Chambers, K C; Kaiser, N; Magnier, E A; Price, P A; Tonry, J L

    2013-01-01

    We present the selection and classification of over a thousand ultraviolet (UV) variable sources discovered in ~ 40 deg^2 of GALEX Time Domain Survey (TDS) NUV images observed with a cadence of 2 days and a baseline of observations of ~ 3 years. The GALEX TDS fields were designed to be in spatial and temporal coordination with the Pan-STARRS1 Medium Deep Survey, which provides deep optical imaging and simultaneous optical transient detections via image differencing. We characterize the GALEX photometric errors empirically as a function of mean magnitude, and select sources that vary at the 5\\sigma level in at least one epoch. We measure the statistical properties of the UV variability, including the structure function on timescales of days and years. We report classifications for the GALEX TDS sample using a combination of optical host colors and morphology, UV light curve characteristics, and matches to archival X-ray, and spectroscopy catalogs. We classify 62% of the sources as active galaxies (358 quasars ...

  8. Model-based Clustering of Categorical Time Series with Multinomial Logit Classification

    Science.gov (United States)

    Frühwirth-Schnatter, Sylvia; Pamminger, Christoph; Winter-Ebmer, Rudolf; Weber, Andrea

    2010-09-01

    A common problem in many areas of applied statistics is to identify groups of similar time series in a panel of time series. However, distance-based clustering methods cannot easily be extended to time series data, where an appropriate distance-measure is rather difficult to define, particularly for discrete-valued time series. Markov chain clustering, proposed by Pamminger and Frühwirth-Schnatter [6], is an approach for clustering discrete-valued time series obtained by observing a categorical variable with several states. This model-based clustering method is based on finite mixtures of first-order time-homogeneous Markov chain models. In order to further explain group membership we present an extension to the approach of Pamminger and Frühwirth-Schnatter [6] by formulating a probabilistic model for the latent group indicators within the Bayesian classification rule by using a multinomial logit model. The parameters are estimated for a fixed number of clusters within a Bayesian framework using an Markov chain Monte Carlo (MCMC) sampling scheme representing a (full) Gibbs-type sampler which involves only draws from standard distributions. Finally, an application to a panel of Austrian wage mobility data is presented which leads to an interesting segmentation of the Austrian labour market.

  9. Classification Accuracy and Consistency under Item Response Theory Models Using the Package classify

    OpenAIRE

    Chris Wheadon

    2014-01-01

    The R package classify presents a number of useful functions which can be used to estimate the classification accuracy and consistency of assessments. Classification accuracy refers to the probability that an examinees achieved grade classification on an assessment reflects their true grade. Classification consistency refers to the probability that an examinee will be classified into the same grade classification under repeated administrations of an assessment. Understanding the classificatio...

  10. High-throughput Biological Cell Classification Featuring Real-time Optical Data Compression

    CERN Document Server

    Jalali, Bahram; Chen, Claire L

    2015-01-01

    High throughput real-time instruments are needed to acquire large data sets for detection and classification of rare events. Enabled by the photonic time stretch digitizer, a new class of instruments with record throughputs have led to the discovery of optical rogue waves [1], detection of rare cancer cells [2], and the highest analog-to-digital conversion performance ever achieved [3]. Featuring continuous operation at 100 million frames per second and shutter speed of less than a nanosecond, the time stretch camera is ideally suited for screening of blood and other biological samples. It has enabled detection of breast cancer cells in blood with record, one-in-a-million, sensitivity [2]. Owing to their high real-time throughput, instruments produce a torrent of data - equivalent to several 4K movies per second - that overwhelm data acquisition, storage, and processing operations. This predicament calls for technologies that compress images in optical domain and in real-time. An example of this, based on war...

  11. Real-Time Subject-Independent Pattern Classification of Overt and Covert Movements from fNIRS Signals.

    Science.gov (United States)

    Robinson, Neethu; Zaidi, Ali Danish; Rana, Mohit; Prasad, Vinod A; Guan, Cuntai; Birbaumer, Niels; Sitaram, Ranganatha

    2016-01-01

    Recently, studies have reported the use of Near Infrared Spectroscopy (NIRS) for developing Brain-Computer Interface (BCI) by applying online pattern classification of brain states from subject-specific fNIRS signals. The purpose of the present study was to develop and test a real-time method for subject-specific and subject-independent classification of multi-channel fNIRS signals using support-vector machines (SVM), so as to determine its feasibility as an online neurofeedback system. Towards this goal, we used left versus right hand movement execution and movement imagery as study paradigms in a series of experiments. In the first two experiments, activations in the motor cortex during movement execution and movement imagery were used to develop subject-dependent models that obtained high classification accuracies thereby indicating the robustness of our classification method. In the third experiment, a generalized classifier-model was developed from the first two experimental data, which was then applied for subject-independent neurofeedback training. Application of this method in new participants showed mean classification accuracy of 63% for movement imagery tasks and 80% for movement execution tasks. These results, and their corresponding offline analysis reported in this study demonstrate that SVM based real-time subject-independent classification of fNIRS signals is feasible. This method has important applications in the field of hemodynamic BCIs, and neuro-rehabilitation where patients can be trained to learn spatio-temporal patterns of healthy brain activity. PMID:27467528

  12. Real-Time Subject-Independent Pattern Classification of Overt and Covert Movements from fNIRS Signals

    Science.gov (United States)

    Rana, Mohit; Prasad, Vinod A.; Guan, Cuntai; Birbaumer, Niels; Sitaram, Ranganatha

    2016-01-01

    Recently, studies have reported the use of Near Infrared Spectroscopy (NIRS) for developing Brain–Computer Interface (BCI) by applying online pattern classification of brain states from subject-specific fNIRS signals. The purpose of the present study was to develop and test a real-time method for subject-specific and subject-independent classification of multi-channel fNIRS signals using support-vector machines (SVM), so as to determine its feasibility as an online neurofeedback system. Towards this goal, we used left versus right hand movement execution and movement imagery as study paradigms in a series of experiments. In the first two experiments, activations in the motor cortex during movement execution and movement imagery were used to develop subject-dependent models that obtained high classification accuracies thereby indicating the robustness of our classification method. In the third experiment, a generalized classifier-model was developed from the first two experimental data, which was then applied for subject-independent neurofeedback training. Application of this method in new participants showed mean classification accuracy of 63% for movement imagery tasks and 80% for movement execution tasks. These results, and their corresponding offline analysis reported in this study demonstrate that SVM based real-time subject-independent classification of fNIRS signals is feasible. This method has important applications in the field of hemodynamic BCIs, and neuro-rehabilitation where patients can be trained to learn spatio-temporal patterns of healthy brain activity. PMID:27467528

  13. Solid waste bin detection and classification using Dynamic Time Warping and MLP classifier

    International Nuclear Information System (INIS)

    Highlights: • Solid waste bin level detection using Dynamic Time Warping (DTW). • Gabor wavelet filter is used to extract the solid waste image features. • Multi-Layer Perceptron classifier network is used for bin image classification. • The classification performance evaluated by ROC curve analysis. - Abstract: The increasing requirement for Solid Waste Management (SWM) has become a significant challenge for municipal authorities. A number of integrated systems and methods have introduced to overcome this challenge. Many researchers have aimed to develop an ideal SWM system, including approaches involving software-based routing, Geographic Information Systems (GIS), Radio-frequency Identification (RFID), or sensor intelligent bins. Image processing solutions for the Solid Waste (SW) collection have also been developed; however, during capturing the bin image, it is challenging to position the camera for getting a bin area centralized image. As yet, there is no ideal system which can correctly estimate the amount of SW. This paper briefly discusses an efficient image processing solution to overcome these problems. Dynamic Time Warping (DTW) was used for detecting and cropping the bin area and Gabor wavelet (GW) was introduced for feature extraction of the waste bin image. Image features were used to train the classifier. A Multi-Layer Perceptron (MLP) classifier was used to classify the waste bin level and estimate the amount of waste inside the bin. The area under the Receiver Operating Characteristic (ROC) curves was used to statistically evaluate classifier performance. The results of this developed system are comparable to previous image processing based system. The system demonstration using DTW with GW for feature extraction and an MLP classifier led to promising results with respect to the accuracy of waste level estimation (98.50%). The application can be used to optimize the routing of waste collection based on the estimated bin level

  14. Solid waste bin detection and classification using Dynamic Time Warping and MLP classifier

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Md. Shafiqul, E-mail: shafique@eng.ukm.my [Dept. of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangore (Malaysia); Hannan, M.A., E-mail: hannan@eng.ukm.my [Dept. of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangore (Malaysia); Basri, Hassan [Dept. of Civil and Structural Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangore (Malaysia); Hussain, Aini; Arebey, Maher [Dept. of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangore (Malaysia)

    2014-02-15

    Highlights: • Solid waste bin level detection using Dynamic Time Warping (DTW). • Gabor wavelet filter is used to extract the solid waste image features. • Multi-Layer Perceptron classifier network is used for bin image classification. • The classification performance evaluated by ROC curve analysis. - Abstract: The increasing requirement for Solid Waste Management (SWM) has become a significant challenge for municipal authorities. A number of integrated systems and methods have introduced to overcome this challenge. Many researchers have aimed to develop an ideal SWM system, including approaches involving software-based routing, Geographic Information Systems (GIS), Radio-frequency Identification (RFID), or sensor intelligent bins. Image processing solutions for the Solid Waste (SW) collection have also been developed; however, during capturing the bin image, it is challenging to position the camera for getting a bin area centralized image. As yet, there is no ideal system which can correctly estimate the amount of SW. This paper briefly discusses an efficient image processing solution to overcome these problems. Dynamic Time Warping (DTW) was used for detecting and cropping the bin area and Gabor wavelet (GW) was introduced for feature extraction of the waste bin image. Image features were used to train the classifier. A Multi-Layer Perceptron (MLP) classifier was used to classify the waste bin level and estimate the amount of waste inside the bin. The area under the Receiver Operating Characteristic (ROC) curves was used to statistically evaluate classifier performance. The results of this developed system are comparable to previous image processing based system. The system demonstration using DTW with GW for feature extraction and an MLP classifier led to promising results with respect to the accuracy of waste level estimation (98.50%). The application can be used to optimize the routing of waste collection based on the estimated bin level.

  15. Classification of time series gene expression in clinical studies via integration of biological network.

    Directory of Open Access Journals (Sweden)

    Liwei Qian

    Full Text Available The increasing availability of time series expression datasets, although promising, raises a number of new computational challenges. Accordingly, the development of suitable classification methods to make reliable and sound predictions is becoming a pressing issue. We propose, here, a new method to classify time series gene expression via integration of biological networks. We evaluated our approach on 2 different datasets and showed that the use of a hidden Markov model/Gaussian mixture models hybrid explores the time-dependence of the expression data, thereby leading to better prediction results. We demonstrated that the biclustering procedure identifies function-related genes as a whole, giving rise to high accordance in prognosis prediction across independent time series datasets. In addition, we showed that integration of biological networks into our method significantly improves prediction performance. Moreover, we compared our approach with several state-of-the-art algorithms and found that our method outperformed previous approaches with regard to various criteria. Finally, our approach achieved better prediction results on early-stage data, implying the potential of our method for practical prediction.

  16. Classification of time series gene expression in clinical studies via integration of biological network.

    Science.gov (United States)

    Qian, Liwei; Zheng, Haoran; Zhou, Hong; Qin, Ruibin; Li, Jinlong

    2013-01-01

    The increasing availability of time series expression datasets, although promising, raises a number of new computational challenges. Accordingly, the development of suitable classification methods to make reliable and sound predictions is becoming a pressing issue. We propose, here, a new method to classify time series gene expression via integration of biological networks. We evaluated our approach on 2 different datasets and showed that the use of a hidden Markov model/Gaussian mixture models hybrid explores the time-dependence of the expression data, thereby leading to better prediction results. We demonstrated that the biclustering procedure identifies function-related genes as a whole, giving rise to high accordance in prognosis prediction across independent time series datasets. In addition, we showed that integration of biological networks into our method significantly improves prediction performance. Moreover, we compared our approach with several state-of-the-art algorithms and found that our method outperformed previous approaches with regard to various criteria. Finally, our approach achieved better prediction results on early-stage data, implying the potential of our method for practical prediction. PMID:23516469

  17. Soft supervised self-organizing mapping (3SOM) for improving land cover classification with MODIS time-series

    Science.gov (United States)

    Lawawirojwong, Siam

    Classification of remote sensing data has long been a fundamental technique for studying vegetation and land cover. Furthermore, land use and land cover maps are a basic need for environmental science. These maps are important for crop system monitoring and are also valuable resources for decision makers. Therefore, an up-to-date and highly accurate land cover map with detailed and timely information is required for the global environmental change research community to support natural resource management, environmental protection, and policy making. However, there appears to be a number of limitations associated with data utilization such as weather conditions, data availability, cost, and the time needed for acquiring and processing large numbers of images. Additionally, improving the classification accuracy and reducing the classification time have long been the goals of remote sensing research and they still require the further study. To manage these challenges, the primary goal of this research is to improve classification algorithms that utilize MODIS-EVI time-series images. A supervised self-organizing map (SSOM) and a soft supervised self-organizing map (3SOM) are modified and improved to increase classification efficiency and accuracy. To accomplish the main goal, the performance of the proposed methods is investigated using synthetic and real landscape data derived from MODIS-EVI time-series images. Two study areas are selected based on a difference of land cover characteristics: one in Thailand and one in the Midwestern U.S. The results indicate that time-series imagery is a potentially useful input dataset for land cover classification. Moreover, the SSOM with time-series data significantly outperforms the conventional classification techniques of the Gaussian maximum likelihood classifier (GMLC) and backpropagation neural network (BPNN). In addition, the 3SOM employed as a soft classifier delivers a more accurate classification than the SSOM applied as

  18. Talar Fractures and Dislocations: A Radiologist's Guide to Timely Diagnosis and Classification.

    Science.gov (United States)

    Melenevsky, Yulia; Mackey, Robert A; Abrahams, R Brad; Thomson, Norman B

    2015-01-01

    The talus, the second largest tarsal bone, has distinctive imaging characteristics and injury patterns. The predominantly extraosseous vascular supply of the talus predisposes it to significant injury in the setting of trauma. In addition, the lack of muscular attachments and absence of a secondary blood supply can lead to subsequent osteonecrosis. Although talar fractures account for less than 1% of all fractures, they commonly result from high-energy trauma and may lead to complications and long-term morbidity if not recognized and managed appropriately. While initial evaluation is with foot and ankle radiographs, computed tomography (CT) is often performed to evaluate the extent of the fracture, displacement, comminution, intra-articular extension, and associated injuries. Talar fractures are divided by anatomic region: head, neck, and body. Talar head fractures can be treated conservatively if nondisplaced, warranting careful radiographic and CT evaluation to assess rotation, displacement, and extension into the neck. The modified Hawkins-Canale classification of talar neck fractures is most commonly used due to its simplicity, usefulness in guiding treatment, and prognostic value, as it correlates associated malalignment with risk of subsequent osteonecrosis. Isolated talar body fractures may be more common than previously thought. The Sneppen classification further divides talar body fractures into osteochondral talar dome, lateral and posterior process, and shear and crush comminuted central body fractures. Crush comminuted central body fractures carry a poor prognosis due to nonanatomic reduction, bone loss, and subsequent osteonecrosis. Lateral process fractures can be radiographically occult and require a higher index of suspicion for successful diagnosis. Subtalar dislocations are often accompanied by fractures, necessitating postreduction CT. Familiarity with the unique talar anatomy and injury patterns is essential for radiologists to facilitate

  19. Real time gait pattern classification from chest worn accelerometry during a loaded road march.

    Science.gov (United States)

    Clements, Cynthia M; Buller, Mark J; Welles, Alexander P; Tharion, William J

    2012-01-01

    Accelerometers, whether in smart phones or wearable physiological monitoring systems are becoming widely used to identify movement and activities of free living individuals. Although there has been much work in applying computationally intensive methods to this problem, this paper focuses on developing a real-time gait analysis approach that is intuitive, requires no individual calibration, can be extended to complex gait analysis, and can readily be adopted by ambulatory physiological monitors for use in real time. Chest-mounted tri-axial accelerometry data were collected from sixty-one male U.S. Army Ranger candidates engaged in an 8 or 12 mile loaded (35 Kg packs) timed road march. The pace of the road march was such that volunteers needed to both walk and run. To provide intuitive features we examined the periodic patterns generated from 4s periods of movement from the vertical and longitudinal accelerometer axes. Applying the "eigenfaces" face recognition approach we used Principal Components Analysis to find a single basis vector from 10% of the data (n=6) that could distinguish patterns of walk and run with a classification rate of 95% and 90% (n=55) respectively. Because these movement features are based on a gridded frequency count, the method is applicable for use by body-worn microprocessors. PMID:23365905

  20. Volumetric response classification in metastatic solid tumors on MSCT: Initial results in a whole-body setting

    Energy Technology Data Exchange (ETDEWEB)

    Wulff, A.M., E-mail: a.wulff@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Fabel, M. [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Freitag-Wolf, S., E-mail: freitag@medinfo.uni-kiel.de [Institut für Medizinische Informatik und Statistik, Brunswiker Str. 10, 24105 Kiel (Germany); Tepper, M., E-mail: m.tepper@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Knabe, H.M., E-mail: h.knabe@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Schäfer, J.P., E-mail: jp.schaefer@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Jansen, O., E-mail: o.jansen@neurorad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Bolte, H., E-mail: hendrik.bolte@ukmuenster.de [Klinik für Nuklearmedizin, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster (Germany)

    2013-10-01

    Purpose: To examine technical parameters of measurement accuracy and differences in tumor response classification using RECIST 1.1 and volumetric assessment in three common metastasis types (lung nodules, liver lesions, lymph node metastasis) simultaneously. Materials and methods: 56 consecutive patients (32 female) aged 41–82 years with a wide range of metastatic solid tumors were examined with MSCT for baseline and follow up. Images were evaluated by three experienced radiologists using manual measurements and semi-automatic lesion segmentation. Institutional ethics review was obtained and all patients gave written informed consent. Data analysis comprised interobserver variability operationalized as coefficient of variation and categorical response classification according to RECIST 1.1 for both manual and volumetric measures. Continuous data were assessed for statistical significance with Wilcoxon signed-rank test and categorical data with Fleiss kappa. Results: Interobserver variability was 6.3% (IQR 4.6%) for manual and 4.1% (IQR 4.4%) for volumetrically obtained sum of relevant diameters (p < 0.05, corrected). 4–8 patients’ response to therapy was classified differently across observers by using volumetry compared to standard manual measurements. Fleiss kappa revealed no significant difference in categorical agreement of response classification between manual (0.7558) and volumetric (0.7623) measurements. Conclusion: Under standard RECIST thresholds there was no advantage of volumetric compared to manual response evaluation. However volumetric assessment yielded significantly lower interobserver variability. This may allow narrower thresholds for volumetric response classification in the future.

  1. Volumetric response classification in metastatic solid tumors on MSCT: Initial results in a whole-body setting

    International Nuclear Information System (INIS)

    Purpose: To examine technical parameters of measurement accuracy and differences in tumor response classification using RECIST 1.1 and volumetric assessment in three common metastasis types (lung nodules, liver lesions, lymph node metastasis) simultaneously. Materials and methods: 56 consecutive patients (32 female) aged 41–82 years with a wide range of metastatic solid tumors were examined with MSCT for baseline and follow up. Images were evaluated by three experienced radiologists using manual measurements and semi-automatic lesion segmentation. Institutional ethics review was obtained and all patients gave written informed consent. Data analysis comprised interobserver variability operationalized as coefficient of variation and categorical response classification according to RECIST 1.1 for both manual and volumetric measures. Continuous data were assessed for statistical significance with Wilcoxon signed-rank test and categorical data with Fleiss kappa. Results: Interobserver variability was 6.3% (IQR 4.6%) for manual and 4.1% (IQR 4.4%) for volumetrically obtained sum of relevant diameters (p < 0.05, corrected). 4–8 patients’ response to therapy was classified differently across observers by using volumetry compared to standard manual measurements. Fleiss kappa revealed no significant difference in categorical agreement of response classification between manual (0.7558) and volumetric (0.7623) measurements. Conclusion: Under standard RECIST thresholds there was no advantage of volumetric compared to manual response evaluation. However volumetric assessment yielded significantly lower interobserver variability. This may allow narrower thresholds for volumetric response classification in the future

  2. Improved prognostic classification of breast cancer defined by antagonistic activation patterns of immune response pathway modules

    International Nuclear Information System (INIS)

    Elucidating the activation pattern of molecular pathways across a given tumour type is a key challenge necessary for understanding the heterogeneity in clinical response and for developing novel more effective therapies. Gene expression signatures of molecular pathway activation derived from perturbation experiments in model systems as well as structural models of molecular interactions ('model signatures') constitute an important resource for estimating corresponding activation levels in tumours. However, relatively few strategies for estimating pathway activity from such model signatures exist and only few studies have used activation patterns of pathways to refine molecular classifications of cancer. Here we propose a novel network-based method for estimating pathway activation in tumours from model signatures. We find that although the pathway networks inferred from cancer expression data are highly consistent with the prior information contained in the model signatures, that they also exhibit a highly modular structure and that estimation of pathway activity is dependent on this modular structure. We apply our methodology to a panel of 438 estrogen receptor negative (ER-) and 785 estrogen receptor positive (ER+) breast cancers to infer activation patterns of important cancer related molecular pathways. We show that in ER negative basal and HER2+ breast cancer, gene expression modules reflecting T-cell helper-1 (Th1) and T-cell helper-2 (Th2) mediated immune responses play antagonistic roles as major risk factors for distant metastasis. Using Boolean interaction Cox-regression models to identify non-linear pathway combinations associated with clinical outcome, we show that simultaneous high activation of Th1 and low activation of a TGF-beta pathway module defines a subtype of particularly good prognosis and that this classification provides a better prognostic model than those based on the individual pathways. In ER+ breast cancer, we find that

  3. The Galex Time Domain Survey. I. Selection And Classification of Over a Thousand Ultraviolet Variable Sources

    Science.gov (United States)

    Gezari, S.; Martin, D. C.; Forster, K.; Neill, J. D.; Huber, M.; Heckman, T.; Bianchi, L.; Morrissey, P.; Neff, S. G.; Seibert, M.; Schiminovich, D.; Wyder, T. K.; Burgett, W. S.; Chambers, K. C.; Kaiser, N.; Magnier, E. A.; Price, P. A.; Tonry, J. L.

    2013-01-01

    We present the selection and classification of over a thousand ultraviolet (UV) variable sources discovered in approximately 40 deg(exp 2) of GALEX Time Domain Survey (TDS) NUV images observed with a cadence of 2 days and a baseline of observations of approximately 3 years. The GALEX TDS fields were designed to be in spatial and temporal coordination with the Pan-STARRS1 Medium Deep Survey, which provides deep optical imaging and simultaneous optical transient detections via image differencing. We characterize the GALEX photometric errors empirically as a function of mean magnitude, and select sources that vary at the 5 sigma level in at least one epoch. We measure the statistical properties of the UV variability, including the structure function on timescales of days and years. We report classifications for the GALEX TDS sample using a combination of optical host colors and morphology, UV light curve characteristics, and matches to archival X-ray, and spectroscopy catalogs. We classify 62% of the sources as active galaxies (358 quasars and 305 active galactic nuclei), and 10% as variable stars (including 37 RR Lyrae, 53 M dwarf flare stars, and 2 cataclysmic variables). We detect a large-amplitude tail in the UV variability distribution for M-dwarf flare stars and RR Lyrae, reaching up to absolute value(?m) = 4.6 mag and 2.9 mag, respectively. The mean amplitude of the structure function for quasars on year timescales is five times larger than observed at optical wavelengths. The remaining unclassified sources include UV-bright extragalactic transients, two of which have been spectroscopically confirmed to be a young core-collapse supernova and a flare from the tidal disruption of a star by dormant supermassive black hole. We calculate a surface density for variable sources in the UV with NUV less than 23 mag and absolute value(?m) greater than 0.2 mag of approximately 8.0, 7.7, and 1.8 deg(exp -2) for quasars, active galactic nuclei, and RR Lyrae stars

  4. THE GALEX TIME DOMAIN SURVEY. I. SELECTION AND CLASSIFICATION OF OVER A THOUSAND ULTRAVIOLET VARIABLE SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Gezari, S. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Martin, D. C.; Forster, K.; Neill, J. D.; Morrissey, P.; Wyder, T. K. [Astronomy Department, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Huber, M.; Burgett, W. S.; Chambers, K. C.; Kaiser, N.; Magnier, E. A.; Tonry, J. L. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Heckman, T.; Bianchi, L. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Neff, S. G. [Laboratory for Astronomy and Solar Physics, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Seibert, M. [Observatories of the Carnegie Institute of Washington, Pasadena, CA 90095 (United States); Schiminovich, D. [Department of Astronomy, Columbia University, New York, NY 10027 (United States); Price, P. A., E-mail: suvi@astro.umd.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2013-03-20

    We present the selection and classification of over a thousand ultraviolet (UV) variable sources discovered in {approx}40 deg{sup 2} of GALEX Time Domain Survey (TDS) NUV images observed with a cadence of 2 days and a baseline of observations of {approx}3 years. The GALEX TDS fields were designed to be in spatial and temporal coordination with the Pan-STARRS1 Medium Deep Survey, which provides deep optical imaging and simultaneous optical transient detections via image differencing. We characterize the GALEX photometric errors empirically as a function of mean magnitude, and select sources that vary at the 5{sigma} level in at least one epoch. We measure the statistical properties of the UV variability, including the structure function on timescales of days and years. We report classifications for the GALEX TDS sample using a combination of optical host colors and morphology, UV light curve characteristics, and matches to archival X-ray, and spectroscopy catalogs. We classify 62% of the sources as active galaxies (358 quasars and 305 active galactic nuclei), and 10% as variable stars (including 37 RR Lyrae, 53 M dwarf flare stars, and 2 cataclysmic variables). We detect a large-amplitude tail in the UV variability distribution for M-dwarf flare stars and RR Lyrae, reaching up to |{Delta}m| = 4.6 mag and 2.9 mag, respectively. The mean amplitude of the structure function for quasars on year timescales is five times larger than observed at optical wavelengths. The remaining unclassified sources include UV-bright extragalactic transients, two of which have been spectroscopically confirmed to be a young core-collapse supernova and a flare from the tidal disruption of a star by dormant supermassive black hole. We calculate a surface density for variable sources in the UV with NUV < 23 mag and |{Delta}m| > 0.2 mag of {approx}8.0, 7.7, and 1.8 deg{sup -2} for quasars, active galactic nuclei, and RR Lyrae stars, respectively. We also calculate a surface density rate in the

  5. The GALEX Time Domain Survey. I. Selection and Classification of Over a Thousand Ultraviolet Variable Sources

    Science.gov (United States)

    Gezari, S.; Martin, D. C.; Forster, K.; Neill, J. D.; Huber, M.; Heckman, T.; Bianchi, L.; Morrissey, P.; Neff, S. G.; Seibert, M.; Schiminovich, D.; Wyder, T. K.; Burgett, W. S.; Chambers, K. C.; Kaiser, N.; Magnier, E. A.; Price, P. A.; Tonry, J. L.

    2013-03-01

    We present the selection and classification of over a thousand ultraviolet (UV) variable sources discovered in ~40 deg2 of GALEX Time Domain Survey (TDS) NUV images observed with a cadence of 2 days and a baseline of observations of ~3 years. The GALEX TDS fields were designed to be in spatial and temporal coordination with the Pan-STARRS1 Medium Deep Survey, which provides deep optical imaging and simultaneous optical transient detections via image differencing. We characterize the GALEX photometric errors empirically as a function of mean magnitude, and select sources that vary at the 5σ level in at least one epoch. We measure the statistical properties of the UV variability, including the structure function on timescales of days and years. We report classifications for the GALEX TDS sample using a combination of optical host colors and morphology, UV light curve characteristics, and matches to archival X-ray, and spectroscopy catalogs. We classify 62% of the sources as active galaxies (358 quasars and 305 active galactic nuclei), and 10% as variable stars (including 37 RR Lyrae, 53 M dwarf flare stars, and 2 cataclysmic variables). We detect a large-amplitude tail in the UV variability distribution for M-dwarf flare stars and RR Lyrae, reaching up to |Δm| = 4.6 mag and 2.9 mag, respectively. The mean amplitude of the structure function for quasars on year timescales is five times larger than observed at optical wavelengths. The remaining unclassified sources include UV-bright extragalactic transients, two of which have been spectroscopically confirmed to be a young core-collapse supernova and a flare from the tidal disruption of a star by dormant supermassive black hole. We calculate a surface density for variable sources in the UV with NUV 0.2 mag of ~8.0, 7.7, and 1.8 deg-2 for quasars, active galactic nuclei, and RR Lyrae stars, respectively. We also calculate a surface density rate in the UV for transient sources, using the effective survey time at the

  6. THE GALEX TIME DOMAIN SURVEY. I. SELECTION AND CLASSIFICATION OF OVER A THOUSAND ULTRAVIOLET VARIABLE SOURCES

    International Nuclear Information System (INIS)

    We present the selection and classification of over a thousand ultraviolet (UV) variable sources discovered in ∼40 deg2 of GALEX Time Domain Survey (TDS) NUV images observed with a cadence of 2 days and a baseline of observations of ∼3 years. The GALEX TDS fields were designed to be in spatial and temporal coordination with the Pan-STARRS1 Medium Deep Survey, which provides deep optical imaging and simultaneous optical transient detections via image differencing. We characterize the GALEX photometric errors empirically as a function of mean magnitude, and select sources that vary at the 5σ level in at least one epoch. We measure the statistical properties of the UV variability, including the structure function on timescales of days and years. We report classifications for the GALEX TDS sample using a combination of optical host colors and morphology, UV light curve characteristics, and matches to archival X-ray, and spectroscopy catalogs. We classify 62% of the sources as active galaxies (358 quasars and 305 active galactic nuclei), and 10% as variable stars (including 37 RR Lyrae, 53 M dwarf flare stars, and 2 cataclysmic variables). We detect a large-amplitude tail in the UV variability distribution for M-dwarf flare stars and RR Lyrae, reaching up to |Δm| = 4.6 mag and 2.9 mag, respectively. The mean amplitude of the structure function for quasars on year timescales is five times larger than observed at optical wavelengths. The remaining unclassified sources include UV-bright extragalactic transients, two of which have been spectroscopically confirmed to be a young core-collapse supernova and a flare from the tidal disruption of a star by dormant supermassive black hole. We calculate a surface density for variable sources in the UV with NUV 0.2 mag of ∼8.0, 7.7, and 1.8 deg–2 for quasars, active galactic nuclei, and RR Lyrae stars, respectively. We also calculate a surface density rate in the UV for transient sources, using the effective survey time at

  7. Classification and Monitoring of Reed Belts Using Dual-Polarimetric TerraSAR-X Time Series

    Directory of Open Access Journals (Sweden)

    Iris Heine

    2016-06-01

    Full Text Available Synthetic aperture radar polarimetry (PolSAR and polarimetric decomposition techniques have proven to be useful tools for wetland mapping. In this study we classify reed belts and monitor their phenological changes at a natural lake in northeastern Germany using dual-co-polarized (HH, VV TerraSAR-X time series. The time series comprises 19 images, acquired between August 2014 and May 2015, in ascending and descending orbit. We calculated different polarimetric indices using the HH and VV intensities, the dual-polarimetric coherency matrix including dominant and mean alpha scattering angles, and entropy and anisotropy (normalized eigenvalue difference as well as combinations of entropy and anisotropy for the analysis of the scattering scenarios. The image classifications were performed with the random forest classifier and validated with high-resolution digital orthophotos. The time series analysis of the reed belts revealed significant seasonal changes for the double-bounce–sensitive parameters (intensity ratio HH/VV and intensity difference HH-VV, the co-polarimetric coherence phase and the dominant and mean alpha scattering angles and in the dual-polarimetric coherence (amplitude, anisotropy, entropy, and anisotropy-entropy combinations; whereas in summer dense leaves cause volume scattering, in winter, after leaves have fallen, the reed stems cause predominately double-bounce scattering. Our study showed that the five most important parameters for the classification of reed are the intensity difference HH-VV, the mean alpha scattering angle, intensity ratio HH/VV, and the coherence (phase. Due to the better separation of reed and other vegetation (deciduous forest, coniferous forest, meadow, winter acquisitions are preferred for the mapping of reed. Multi-temporal stacks of winter images performed better than summer ones. The combination of ascending and descending images also improved the result as it reduces the influence of the sensor

  8. Unification of dark energy and dark matter based on the Petrov classification and space-time symmetry

    Science.gov (United States)

    Dymnikova, Irina

    2016-01-01

    The Petrov classification of stress-energy tensors provides a model-independent definition of a vacuum by the algebraic structure of its stress-energy tensor and implies the existence of vacua whose symmetry is reduced as compared with the maximally symmetric de Sitter vacuum associated with the Einstein cosmological term. This allows to describe a vacuum in general setting by dynamical vacuum dark fluid, presented by a variable cosmological term with the reduced symmetry which makes vacuum dark fluid essentially anisotropic and allows it to be evolving and clustering. The relevant regular solutions to the Einstein equations describe regular cosmological models with time-evolving and spatially inhomogeneous vacuum dark energy, and compact vacuum objects generically related to a dark energy through the de Sitter vacuum interior: regular black holes, their remnants and self-gravitating vacuum solitons — which can be responsible for observational effects typically related to a dark matter. The mass of objects with de Sitter interior is generically related to vacuum dark energy and to breaking of space-time symmetry.

  9. Real-Time Classification of Bladder Events for Effective Diagnosis and Treatment of Urinary Incontinence.

    Science.gov (United States)

    Karam, Robert; Bourbeau, Dennis; Majerus, Steve; Makovey, Iryna; Goldman, Howard B; Damaser, Margot S; Bhunia, Swarup

    2016-04-01

    Diagnosis of lower urinary tract dysfunction with urodynamics has historically relied on data acquired from multiple sensors using nonphysiologically fast cystometric filling. In addition, state-of-the-art neuromodulation approaches to restore bladder function could benefit from a bladder sensor for closed-loop control, but a practical sensor and automated data analysis are not available. We have developed an algorithm for real-time bladder event detection based on a single in situ sensor, making it attractive for both extended ambulatory bladder monitoring and closed-loop control of stimulation systems for diagnosis and treatment of bladder overactivity. Using bladder pressure data acquired from 14 human subjects with neurogenic bladder, we developed context-aware thresholding, a novel, parameterized, user-tunable algorithmic framework capable of real-time classification of bladder events, such as detrusor contractions, from single-sensor bladder pressure data. We compare six event detection algorithms with both single-sensor and two-sensor systems using a metric termed Conditional Stimulation Score, which ranks algorithms based on projected stimulation efficacy and efficiency. We demonstrate that adaptive methods are more robust against day-to-day variations than static thresholding, improving sensitivity and specificity without parameter modifications. Relative to other methods, context-aware thresholding is fast, robust, highly accurate, noise-tolerant, and amenable to energy-efficient hardware implementation, which is important for mapping to an implant device. PMID:26292331

  10. Data Mining and Machine Learning in Time-Domain Discovery and Classification

    Science.gov (United States)

    Bloom, Joshua S.; Richards, Joseph W.

    2012-03-01

    -domain aspect of the data and the objects of interest presents some unique challenges. First, any collection, storage, transport, and computational framework for processing the streaming data must be able to keep up with the dataflow. This is not necessarily true, for instance, with static sky science, where metrics of interest can be computed off-line and on a timescale much longer than the time required to obtain the data. Second, many types of transient (one-off) events evolve quickly in time and require more observations to fully understand the nature of the events. This demands that time-changing events are quickly discovered, classified, and broadcast to other follow-up facilities. All of this must happen robustly with, in some cases, very limited data. Last, the process of discovery and classification must be calibrated to the available resources for computation and follow-up. That is, the precision of classification must be weighed against the computational cost of producing that level of precision. Likewise, the cost of being wrong about the classification of some sorts of sources must be balanced against the scientific gains about being right about the classification of other types of sources. Quantifying these trade-offs, especially in the presence of a limited amount of follow-up resources (such as the availability of larger telescope observations) is not straightforward and inheres domain-specific imperatives that will, in general, differ from astronomer to astronomer. This chapter presents an overview of the current directions in ML and data-mining techniques in the context of time-domain astronomy. Ultimately the goal - if not just the necessity given the data rates and the diversity of questions to be answered - is to abstract the traditional role of astronomer in the entire scientific process. In some sense, this takes us full circle from the pre modern view of the scientific pursuit presented in Vermeer's "The Astronomer" (Figure 6.2): in broad daylight, he

  11. The Response Time Analysis of Digital Broadcasting System

    Institute of Scientific and Technical Information of China (English)

    WANG Shuo; ZHANG Jiang-ling; FENG Dan

    2005-01-01

    Digital broadcasting system has become a highlight of research on computer application. To respond to the changes of the playbill in the broadcasting system in real time, the response time of the system must be studied. There is scarcely the research on this area currently. The influence factors in the response time are analyzed; the model on the response time of the system service is built; how the influence factors affect the response time of the system service is validated; and four improvement measures are proposed to minimize the response time of system service.

  12. Improving Adaptive Learning Technology through the Use of Response Times

    Science.gov (United States)

    Mettler, Everett; Massey, Christine M.; Kellman, Philip J.

    2011-01-01

    Adaptive learning techniques have typically scheduled practice using learners' accuracy and item presentation history. We describe an adaptive learning system (Adaptive Response Time Based Sequencing--ARTS) that uses both accuracy and response time (RT) as direct inputs into sequencing. Response times are used to assess learning strength and…

  13. Time reversal based news methods for localization and classification of nonlinear vibrations in bio-mechanical media

    Czech Academy of Sciences Publication Activity Database

    Dos Santos, S.; Farová, Zuzana; Kůs, V.; Převorovský, Zdeněk

    Bangkok : International Institute of Acoustics and Vibration, 2013 - (Crocker, M.; Pawelczyk, M.), s. 1-8 ISBN 978-616-551-682-2. ISSN 2329-3675. [International Congress on Sound & Vibration /20./. Bangkok (TH), 07.07.2013-11.07.2013] Institutional support: RVO:61388998 Keywords : time reversal * statistical classification * chirp excitation Subject RIV: BB - Applied Statistics, Operational Research

  14. Artificial Neural Network classification of operator workload with an assessment of time variation and noise-enhancement to increase performance

    Directory of Open Access Journals (Sweden)

    Alexander James Casson

    2014-12-01

    Full Text Available Workload classification---the determination of whether a human operator is in a high or low workload state to allow their working environment to be optimized---is an emerging application of passive Brain-Computer Interface (BCI systems. Practical systems must not only accurately detect the current workload state, but also have good temporal performance: requiring little time to set up and train the classifier, and ensuring that the reported performance level is consistent and predictable over time. This paper investigates the temporal performance of an Artificial Neural Network based classification system. For networks trained on little EEG data good classification accuracies (86% are achieved over very short time frames, but substantial decreases in accuracy are found as the time gap between the network training and the actual use is increased. Noise-enhanced processing, where artificially generated noise is deliberately added to the testing signals, is investigated as a potential technique to mitigate this degradation without requiring the network to be re-trained using more data. Small stochastic resonance effects are demonstrated whereby the classification process gets better in the presence of more noise. The effect is small and does not eliminate the need for re-training, but it is consistent, and this is the first demonstration of such effects for non-evoked/free-running EEG signals suitable for passive BCI.

  15. System measures response time of photomultiplier tubes

    Science.gov (United States)

    Lauver, M. R.

    1968-01-01

    Calibration system enables precise determination of rise time of photosensitive detectors. To perform a calibration, the time-voltage curve of the excitation voltage for a light source is compared with the time-voltage curve of the voltage output from a photosensitive detector which is responding to the light.

  16. A Framework for Real-Time Collection, Analysis, and Classification of Ubiquitous Infrasound Data

    Science.gov (United States)

    Christe, A.; Garces, M. A.; Magana-Zook, S. A.; Schnurr, J. M.

    2015-12-01

    Traditional infrasound arrays are generally expensive to install and maintain. There are ~10^3 infrasound channels on Earth today. The amount of data currently provided by legacy architectures can be processed on a modest server. However, the growing availability of low-cost, ubiquitous, and dense infrasonic sensor networks presents a substantial increase in the volume, velocity, and variety of data flow. Initial data from a prototype ubiquitous global infrasound network is already pushing the boundaries of traditional research server and communication systems, in particular when serving data products over heterogeneous, international network topologies. We present a scalable, cloud-based approach for capturing and analyzing large amounts of dense infrasonic data (>10^6 channels). We utilize Akka actors with WebSockets to maintain data connections with infrasound sensors. Apache Spark provides streaming, batch, machine learning, and graph processing libraries which will permit signature classification, cross-correlation, and other analytics in near real time. This new framework and approach provide significant advantages in scalability and cost.

  17. Generation of a Supervised Classification Algorithm for Time-Series Variable Stars with an Application to the LINEAR Dataset

    CERN Document Server

    Johnston, Kyle B

    2016-01-01

    With the advent of digital astronomy, new benefits and new problems have been presented to the modern day astronomer. While data can be captured in a more efficient and accurate manor using digital means, the efficiency of data retrieval has led to an overload of scientific data for processing and storage. This paper will focus on the construction and application of a supervised pattern classification algorithm for the identification of variable stars. Given the reduction of a survey of stars into a standard feature space, the problem of using prior patterns to identify new observed patterns can be reduced to time tested classification methodologies and algorithms. Such supervised methods, so called because the user trains the algorithms prior to application using patterns with known classes or labels, provide a means to probabilistically determine the estimated class type of new observations. This paper will demonstrate the construction and application of a supervised classification algorithm on variable sta...

  18. Space and time reversals: II. Phenomenological classification of elementary particles; quantum numbers and conservation laws

    International Nuclear Information System (INIS)

    Using the six ''matrices'', we give a classification of the leptons and of the flavours of quarks in three families containing particles and antiparticles; quantum numbers and condensed forms of conservation laws are also discussed for weak and strong interactions

  19. It is time to bring borderline intellectual functioning back into the main fold of classification systems.

    Science.gov (United States)

    Wieland, Jannelien; Zitman, Frans G

    2016-08-01

    Borderline intellectual functioning is an important and frequently unrecognised comorbid condition relevant to the diagnosis and treatment of any and all psychiatric disorders. In the DSM-IV-TR, it is defined by IQ in the 71-84 range. In DSM-5, IQ boundaries are no longer part of the classification, leaving the concept without a clear definition. This modification is one of the least highlighted changes in DSM-5. In this article we describe the history of the classification of borderline intellectual functioning. We provide information about it and on the importance of placing it in the right context and in the right place in future DSM editions and other classification systems such as the International Classification of Diseases. PMID:27512590

  20. Classification of coronary artery bifurcation lesions and treatments: Time for a consensus!

    DEFF Research Database (Denmark)

    Louvard, Yves; Thomas, Martyn; Dzavik, Vladimir;

    2007-01-01

    , heterogeneity, and inadequate description of techniques implemented. Methods: The aim is to propose a consensus established by the European Bifurcation Club (EBC), on the definition and classification of bifurcation lesions and treatments implemented with the purpose of allowing comparisons between techniques...... proposes a new classification of bifurcation lesions and their treatments to permit accurate comparisons of well described techniques in homogeneous lesion groups. (c) 2008 Wiley-Liss, Inc. Udgivelsesdato: 2007-Nov-5...

  1. Design of responsive polymer surfaces with ultrafast response time

    Science.gov (United States)

    Genzer, Jan; Ozcam, Evren; Willoughby, Julie

    2009-03-01

    Responsive surfaces with tailorable surface-reconstruction kinetics and switching hysteresis were prepared from poly(vinylmethylsiloxane) (PVMS) networks modified with thiol alkanes to provide hydrophobic or hydrophilic surface properties. The cooperative effects of polymer mobility, arising from the high flexibility of the siloxane backbone, and the enthalpic interactions between the contacting medium and the PVMS functionalized surface control the degree of responsiveness. Exposing the modified-elastomer surfaces to water resulted in rearrangement of the hydrophilic alkanes at the surface. The kinetics of reconstruction and reversibility were established by measuring the surface wettability via dynamic contact angle. By controlling the formation of semi-crystalline regions in our substrates we demonstrate either ``sluggish'' kinetics and eventual surface ``freezing'' and stability or stimuli-responsive substrates with a magnitude of change and repeated reversibility unparallel to most polymeric surfaces.

  2. Response time patterns in a stated choice experiment

    DEFF Research Database (Denmark)

    Börjesson, Maria; Fosgerau, Mogens

    2015-01-01

    This paper studies how response times vary between unlabelled binary choice occasions in a stated choice (SC) experiment, with alternatives differing with respect to in-vehicle travel time and travel cost. The pattern of response times is interpreted as an indicator of the cognitive processes...... employed by the respondents when making their choices. We find clear signs of reference-dependence in response times in the form of a strong gain–loss asymmetry. Moreover, different patterns of response times for travel time and travel cost indicate that these attributes are processed in different ways by...

  3. Response modalities and time-sharing performance

    Science.gov (United States)

    Vidulich, Michael A.

    1986-01-01

    An experiment performed to investigate the role of resource competition and asymmetric transfer in dual-task performance is described. It is shown that there is an advantage to mixed manual/speech response modality configurations that cannot be accounted for by asymmetric transfer. The present results support the multiple resources approach to the application of speech technology. Once speech recognition achieves an acceptable level of operational reliability, speech controls can be used to reduce resource competition and improve performance in multitask environments.

  4. Latent Factor Models and Analyses for Operator Response Times

    OpenAIRE

    Gaver, Donald Paul; O'Muircheartaigh, I. G.

    1990-01-01

    Two models are presented for the response times of different operators to different tasks where response is initiated by one or more cues provided by the system. One model for the log-response times is a mixed or latent factor model with unequal case fixed effects and variances. The other model for the log-response times is a non-Gaussian log-extreme-value model. Procedures for estimating the parameters by maximum likelihood are presented. The models are used to analyze response time data fro...

  5. Using response times for item selection in adaptive testing

    NARCIS (Netherlands)

    Linden, van der Wim J.

    2008-01-01

    Response times on items can be used to improve item selection in adaptive testing provided that a probabilistic model for their distribution is available. In this research, the author used a hierarchical modeling framework with separate first-level models for the responses and response times and a s

  6. Supervised Classification of Benthic Reflectance in Shallow Subtropical Waters Using a Generalized Pixel-Based Classifier across a Time Series

    Directory of Open Access Journals (Sweden)

    Tara Blakey

    2015-04-01

    Full Text Available We tested a supervised classification approach with Landsat 5 Thematic Mapper (TM data for time-series mapping of seagrass in a subtropical lagoon. Seagrass meadows are an integral link between marine and inland ecosystems and are at risk from upstream processes such as runoff and erosion. Despite the prevalence of image-specific approaches, the classification accuracies we achieved show that pixel-based spectral classes may be generalized and applied to a time series of images that were not included in the classifier training. We employed in-situ data on seagrass abundance from 2007 to 2011 to train and validate a classification model. We created depth-invariant bands from TM bands 1, 2, and 3 to correct for variations in water column depth prior to building the classification model. In-situ data showed mean total seagrass cover remained relatively stable over the study area and period, with seagrass cover generally denser in the west than the east. Our approach achieved mapping accuracies (67% and 76% for two validation years comparable with those attained using spectral libraries, but was simpler to implement. We produced a series of annual maps illustrating inter-annual variability in seagrass occurrence. Accuracies may be improved in future work by better addressing the spatial mismatch between pixel size of remotely sensed data and footprint of field data and by employing atmospheric correction techniques that normalize reflectances across images.

  7. a Study on the SAR Data Observation Time for the Classification of Planting Condition of Paddy Fields

    Science.gov (United States)

    Kimura, A.; Kondo, A.; Mochizuki, K.

    2016-06-01

    In recent years, cultivation methods of rice have been diversified due to the low cost of rice-growing techniques. For example, there is direct sowing of seed rice in paddy field in addition to the practice of usual paddy field to flooding at the time of planting. The yield of the usual paddy field and the direct sowing is different even though the same varieties are grown in the same area. It is necessary to grasp by performing classification for the usual paddy field or direct sowing for the management of agricultural crops. The main objective of this study was to select the observation time for the classification of paddy fields' planting conditions by utilizing Synthetic Aperture Radar TerraSAR-X satellite. The planting conditions included the usual planting of rice, the direct sowing of rice and the soybean. We selected the observation time by the statistical distance of the microwave backscattering in each paddy field for maximizing the planting condition classification. In addition, the satellite data observation timing considered the processing time of the analysis and the acquisition costs. The acquisition was performed 4 periods from 2 periods in the rice growing season and the planting phase. In the current study, we were able to classify the usual planting of rice, the direct sowing of rice and the soybean by TerraSAR-X data for the later planting of rice during mid-May and initial growth of rice in early June.

  8. Response time in online stated choice experiments

    DEFF Research Database (Denmark)

    Campbell, Danny; Mørkbak, Morten Raun; Olsen, Søren Bøye

    2016-01-01

    In this paper, we use paradata relating to the length of time respondents required in a self-administered online stated preference surveys. Although this issue has been previously explored, there is little guidance on how to identify and deal with ‘fast’ and ‘slow’ respondents. In this paper, we ...

  9. Natural vs human-induced changes at the Tauranga Harbour area (New Zealand): a time -series acoustic seabed classification comparison

    Science.gov (United States)

    Capperucci, Ruggero Maria; Bartholomä, Alexander; Renken, Sabrina; De Lange, Willem

    2013-04-01

    The Tauranga Harbour Bay (New Zealand) is a mesotidal estuary system, enclosed by the Matakana barrier island. It hosts the leading export port in New Zealand and the second largest import port by value. Coastal changes are well documented over the last decades, mainly at the southern entrance of the area, between Matakana Island and Mt. Maunganui. It is an extremely dynamic environment, where natural processes are strongly influenced by human activities. In particular, the understanding of the recent evolution of the system is crucial for policymakers. In fact, the cumulative impact due to the maintenance of the port (mainly dredging activities, shipping, facilities construction, but also increasing tourism) and its already approved expansion clashes with the claim of the local Maori communities, which recently leaded to a court action. A hydroacoustic multiple-device survey (Side-scan Sonar SSS, Multibeam Echo-sounder MBES and Single Beam Echo-sounder) coupled with sediment sampling was carried out in March 2011 over an area of 0.8 km2, southern Matakana Island, along the Western Channel. The area is not directly impacted by dredging activities, resulting in an optimal testing site for assessing indirect effects of human disturbance on coastal dynamics. The main goals were: 1. To test the response of different acoustic systems in such a highly dynamic environment; 2. To study the influence of dredging activities on sediment dynamics and habitat changes, by means of comparing the current data with existing ones, in order to distinguish between natural and human induced changes Results demonstrate a good agreement between acoustic classifications from different systems. They seem to be mainly driven by the sediment distribution, with a distinctive fingerprint given by shells and shell fragments. Nevertheless, the presence of relevant topographic features (i.e. large bedform fields) influences swath-looking systems (SSS and MBES). SSS and MBES classifications tend

  10. Real-time detection and classification of anomalous events in streaming data

    Energy Technology Data Exchange (ETDEWEB)

    Ferragut, Erik M.; Goodall, John R.; Iannacone, Michael D.; Laska, Jason A.; Harrison, Lane T.

    2016-04-19

    A system is described for receiving a stream of events and scoring the events based on anomalousness and maliciousness (or other classification). The events can be displayed to a user in user-defined groupings in an animated fashion. The system can include a plurality of anomaly detectors that together implement an algorithm to identify low probability events and detect atypical traffic patterns. The atypical traffic patterns can then be classified as being of interest or not. In one particular example, in a network environment, the classification can be whether the network traffic is malicious or not.

  11. The Importance of Responsibility in Times of Crisis

    Directory of Open Access Journals (Sweden)

    Jacob Dahl Rendtorff

    2014-06-01

    Full Text Available In this paper I would like to show the importance of the concept of responsibility as the foundation of ethics in times of crisis in particular in the fields of politics and economics in the modern civilisation marked by globalization and technological progres. I consider the concept of responsibility as the key notion in order to understand the ethical duty in a modern technological civilisation. We can indeed observe a moralization of the concept of responsibility going beyond a strict legal definition in terms of imputability. The paper begins by discussing the humanistic foundations of such a concept of responsibility. It treats the historical origins of responsibility and it relates this concept to the concept of accountability. On the basis of this historical determination of the concept I would like to present the definition of the concept of responsibility as fundamental ethical principle that has increasing importance as the foundation of the principles of governance in modern welfare states. In this context the paper discusses the extension of the concept of responsibility towards institutional or corporate responsibility where responsibility does not only concerns the responsibility of individuals but also deals with the responsibility of institutional collectivities. In this way the paper is based on the following structure : 1 The ethical foundation of the concept of responsibility 2 Responsibility in technological civilisation 3 Political responsibility for good governance in the welfare state 4 Social responsibility of business corporations in times of globalization 5 Conclusion and discussion : changed conditions of responsibility in modern times.

  12. Classification and Cluster Analysis of Complex Time-of-Flight Secondary Ion Mass Spectrometry for Biological Samples

    OpenAIRE

    Reichenbach, Stephen E; Tian, Xue; Tao, Qingping; Henderson, Alex

    2009-01-01

    Identifying and separating subtly different biological samples is one of the most critical tasks in biological analysis. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is becoming a popular and important technique in the analysis of biological samples, because it can detect molecular information and characterize chemical composition. ToF-SIMS spectra of biological samples are enormously complex with large mass ranges and many peaks. As a result the classification and cluster analys...

  13. A Phenology-Based Classification of Time-Series MODIS Data for Rice Crop Monitoring in Mekong Delta, Vietnam

    OpenAIRE

    Nguyen-Thanh Son; Chi-Farn Chen; Cheng-Ru Chen; Huynh-Ngoc Duc; Ly-Yu Chang

    2013-01-01

    Rice crop monitoring is an important activity for crop management. This study aimed to develop a phenology-based classification approach for the assessment of rice cropping systems in Mekong Delta, Vietnam, using Moderate Resolution Imaging Spectroradiometer (MODIS) data. The data were processed from December 2000, to December 2012, using empirical mode decomposition (EMD) in three main steps: (1) data pre-processing to construct the smooth MODIS enhanced vegetation index (EVI) time-series d...

  14. Automated Real-Time Classification and Decision Making in Massive Data Streams from Synoptic Sky Surveys

    CERN Document Server

    Djorgovski, S G; Donalek, C; Graham, M J; Drake, A J; Turmon, M; Fuchs, T

    2014-01-01

    The nature of scientific and technological data collection is evolving rapidly: data volumes and rates grow exponentially, with increasing complexity and information content, and there has been a transition from static data sets to data streams that must be analyzed in real time. Interesting or anomalous phenomena must be quickly characterized and followed up with additional measurements via optimal deployment of limited assets. Modern astronomy presents a variety of such phenomena in the form of transient events in digital synoptic sky surveys, including cosmic explosions (supernovae, gamma ray bursts), relativistic phenomena (black hole formation, jets), potentially hazardous asteroids, etc. We have been developing a set of machine learning tools to detect, classify and plan a response to transient events for astronomy applications, using the Catalina Real-time Transient Survey (CRTS) as a scientific and methodological testbed. The ability to respond rapidly to the potentially most interesting events is a k...

  15. Classification and monitoring of reed belts using dual-polarimetric TerraSAR-X time series

    Science.gov (United States)

    Heine, Iris; Jagdhuber, Thomas; Itzerott, Sibylle

    2016-04-01

    The shorelines of lakes in northeastern Germany are often covered by reed. These reed belts fulfill an important function as erosion protection, biotope for animals, carbon storage, and as cleaning filter for lake water. However, despite their importance for the limnic ecosystem, reed vegetation in northeastern Germany is not regularly monitored. In this research study we investigate the potential of synthetic aperture radar polarimetry (PolSAR) for seasonal monitoring of reed vegetation. SAR imagery enables sunlight- and (almost) weather-independent monitoring. Polarimetric decomposition techniques allow the physical characterization of the scattering scenario and the involved scatterers. Our study is based on 19 dual-polarimetric (HH/VV) TerraSAR-X images acquired between August 2014 and May 2015. We calculated different polarimetric indices comprising the HH and VV intensities, the dual-polarimetric coherency matrix with dominant and mean alpha scattering angles, entropy and anisotropy (normalized eigen-value difference) as well as combinations of entropy and anisotropy for the analysis of the scattering scenarios. The reed areas in the TerraSAR-X images were classified using a random forest algorithm and validated with high-resolution digital orthophotos. The time series analysis of the reed belts revealed significant seasonal changes in the double bounce sensitive parameters (intensity ratio HH/VV and intensity difference HH-VV, the co-polarimetric coherence phase and the dominant and mean alpha scattering angles). Additionally, the dual-polarimetric coherence (amplitude), anisotropy, entropy, and anisotropy-entropy-combinations showed seasonal changes of reed. In summer, the reed areas are characterized within the X-band SAR data by volume scattering, whereas in winter double-bounce scattering dominates. The volume scattering in summer is caused predominantly by reed leaves. In autumn, the leaves start to wither and fall off, so that in winter predominately

  16. Movie Review Classification and Feature based Summarization of Movie Reviews

    Directory of Open Access Journals (Sweden)

    Sabeeha Mohammed Basheer#1, Syed Farook

    2013-07-01

    Full Text Available Sentiment classification and feature based summarization are essential steps involved with the classification and summarization of movie reviews. The movie review classification is based on sentiment classification and condensed descriptions of movie reviews are generated from the feature based summarization. Experiments are conducted to identify the best machine learning based sentiment classification approach. Latent Semantic Analysis and Latent Dirichlet Allocation were compared to identify features which in turn affects the summary size. The focus of the system design is on classification accuracy and system response time.

  17. Hierarchical Diffusion Models for Two-Choice Response Times

    Science.gov (United States)

    Vandekerckhove, Joachim; Tuerlinckx, Francis; Lee, Michael D.

    2011-01-01

    Two-choice response times are a common type of data, and much research has been devoted to the development of process models for such data. However, the practical application of these models is notoriously complicated, and flexible methods are largely nonexistent. We combine a popular model for choice response times--the Wiener diffusion…

  18. Diagnostic Criteria, Classification and Treatment Goals in Multiple Sclerosis: The Chronicles of Time and Space.

    Science.gov (United States)

    Ntranos, Achilles; Lublin, Fred

    2016-10-01

    Multiple sclerosis (MS) is one of the most diverse human diseases. Since its first description by Charcot in the nineteenth century, the diagnostic criteria, clinical course classification, and treatment goals for MS have been constantly revised and updated to improve diagnostic accuracy, physician communication, and clinical trial design. These changes have improved the clinical outcomes and quality of life for patients with the disease. Recent technological and research breakthroughs will almost certainly further change how we diagnose, classify, and treat MS in the future. In this review, we summarize the key events in the history of MS, explain the reasoning behind the current criteria for MS diagnosis, classification, and treatment, and provide suggestions for further improvements that will keep enhancing the clinical practice of MS. PMID:27549391

  19. Classification of agricultural fields using time series of dual polarimetry TerraSAR-X images

    Directory of Open Access Journals (Sweden)

    S. Mirzaee

    2014-10-01

    Full Text Available Due to its special imaging characteristics, Synthetic Aperture Radar (SAR has become an important source of information for a variety of remote sensing applications dealing with environmental changes. SAR images contain information about both phase and intensity in different polarization modes, making them sensitive to geometrical structure and physical properties of the targets such as dielectric and plant water content. In this study we investigate multi temporal changes occurring to different crop types due to phenological changes using high-resolution TerraSAR-X imagers. The dataset includes 17 dual-polarimetry TSX data acquired from June 2012 to August 2013 in Lorestan province, Iran. Several features are extracted from polarized data and classified using support vector machine (SVM classifier. Training samples and different features employed in classification are also assessed in the study. Results show a satisfactory accuracy for classification which is about 0.91 in kappa coefficient.

  20. Predicting Decisions in Human Social Interactions Using Real-Time fMRI and Pattern Classification

    OpenAIRE

    Maurice Hollmann; Rieger, Jochem W; Sebastian Baecke; Ralf Lützkendorf; Charles Müller; Daniela Adolf; Johannes Bernarding

    2011-01-01

    Negotiation and trade typically require a mutual interaction while simultaneously resting in uncertainty which decision the partner ultimately will make at the end of the process. Assessing already during the negotiation in which direction one's counterpart tends would provide a tremendous advantage. Recently, neuroimaging techniques combined with multivariate pattern classification of the acquired data have made it possible to discriminate subjective states of mind on the basis of their neur...

  1. Real Time Video Quality Representation Classification of Encrypted HTTP Adaptive Video Streaming - the Case of Safari

    OpenAIRE

    Dubin, Ran; Dvir, Amit; Pele, Ofir; Hadar, Ofer; Richman, Itay; Trabelsi, Ofir

    2016-01-01

    The increasing popularity of HTTP adaptive video streaming services has dramatically increased bandwidth requirements on operator networks, which attempt to shape their traffic through Deep Packet Inspection (DPI). However, Google and certain content providers have started to encrypt their video services. As a result, operators often encounter difficulties in shaping their encrypted video traffic via DPI. This highlights the need for new traffic classification methods for encrypted HTTP adapt...

  2. REAL TIME CLASSIFICATION AND CLUSTERING OF IDS ALERTS USING MACHINE LEARNING ALGORITHMS

    Directory of Open Access Journals (Sweden)

    T. Subbulakshmi

    2010-01-01

    Full Text Available Intrusion Detection Systems (IDS monitor a secured network for the evidence of malicious activities originating either inside or outside. Upon identifying a suspicious traffic, IDS generates and logs an alert. Unfortunately, most of the alerts generated are either false positive, i.e. benign traffic that has been classified as intrusions, or irrelevant, i.e. attacks that are not successful. The abundance of false positive alerts makes it difficult for the security analyst to find successful attacks and take remedial action. This paper describes a two phase automatic alert classification system to assist the human analyst in identifying the false positives. In the first phase, the alerts collected from one or more sensors are normalized and similar alerts are grouped to form a meta-alert. These meta-alerts are passively verified with an asset database to find out irrelevant alerts. In addition, an optional alert generalization is also performed for root cause analysis and thereby reduces false positives with human interaction. In the second phase, the reduced alerts are labeled and passed to an alert classifier which uses machine learning techniques for building the classification rules. This helps the analyst in automatic classification of the alerts. The system is tested in real environments and found to be effective in reducing the number of alerts as well as false positives dramatically, and thereby reducing the workload of human analyst.

  3. Statistical Analysis of Categorical Time Series of Atmospheric Elementary Circulation Mechanisms - Dzerdzeevski Classification for the Northern Hemisphere

    Science.gov (United States)

    Brenčič, Mihael

    2016-01-01

    Northern hemisphere elementary circulation mechanisms, defined with the Dzerdzeevski classification and published on a daily basis from 1899–2012, are analysed with statistical methods as continuous categorical time series. Classification consists of 41 elementary circulation mechanisms (ECM), which are assigned to calendar days. Empirical marginal probabilities of each ECM were determined. Seasonality and the periodicity effect were investigated with moving dispersion filters and randomisation procedure on the ECM categories as well as with the time analyses of the ECM mode. The time series were determined as being non-stationary with strong time-dependent trends. During the investigated period, periodicity interchanges with periods when no seasonality is present. In the time series structure, the strongest division is visible at the milestone of 1986, showing that the atmospheric circulation pattern reflected in the ECM has significantly changed. This change is result of the change in the frequency of ECM categories; before 1986, the appearance of ECM was more diverse, and afterwards fewer ECMs appear. The statistical approach applied to the categorical climatic time series opens up new potential insight into climate variability and change studies that have to be performed in the future. PMID:27116375

  4. Model for Predicting End User Web Page Response Time

    CERN Document Server

    Nagarajan, Sathya Narayanan

    2012-01-01

    Perceived responsiveness of a web page is one of the most important and least understood metrics of web page design, and is critical for attracting and maintaining a large audience. Web pages can be designed to meet performance SLAs early in the product lifecycle if there is a way to predict the apparent responsiveness of a particular page layout. Response time of a web page is largely influenced by page layout and various network characteristics. Since the network characteristics vary widely from country to country, accurately modeling and predicting the perceived responsiveness of a web page from the end user's perspective has traditionally proven very difficult. We propose a model for predicting end user web page response time based on web page, network, browser download and browser rendering characteristics. We start by understanding the key parameters that affect perceived response time. We then model each of these parameters individually using experimental tests and statistical techniques. Finally, we d...

  5. Computer Response Time Measurements of Mood, Fatigue and Symptom Scale Items: Implications for Scale Response Time Uses.

    Science.gov (United States)

    Ryman, David H.; And Others

    1988-01-01

    Describes study conducted with U.S. Marine Corps enlisted personnel to measure response time to computer-administered questionnaire items, and to evaluate how measurement of response time might be useful in various research areas. Topics addressed include mood states; the occurrence of straight lining; and experimental effects of sleep loss and…

  6. Real-Time Gas Identification by Analyzing the Transient Response of Capillary-Attached Conductive Gas Sensor

    Directory of Open Access Journals (Sweden)

    Behzad Bahraminejad

    2010-05-01

    Full Text Available In this study, the ability of the Capillary-attached conductive gas sensor (CGS in real-time gas identification was investigated. The structure of the prototype fabricated CGS is presented. Portions were selected from the beginning of the CGS transient response including the first 11 samples to the first 100 samples. Different feature extraction and classification methods were applied on the selected portions. Validation of methods was evaluated to study the ability of an early portion of the CGS transient response in target gas (TG identification. Experimental results proved that applying extracted features from an early part of the CGS transient response along with a classifier can distinguish short-chain alcohols from each other perfectly. Decreasing time of exposition in the interaction between target gas and sensing element improved the reliability of the sensor. Classification rate was also improved and time of identification was decreased. Moreover, the results indicated the optimum interval of the early transient response of the CGS for selecting portions to achieve the best classification rates.

  7. Crop Classification Based on Time Series MODIS EVI and Ground Observation for Three Adjoining Years in Xinjiang.

    Science.gov (United States)

    Muhammad, Shakir; Niu, Zheng; Wang, Li; Aablikim, Abdullah; Hao, Peng-yu; Wang, Chang-yao

    2015-05-01

    There is a regular use of Moderate Resolution Imaging Spectroradiometer (MODIS) 250 meter EVI to classify the crops on a regional level throughout the world. A rapid agricultural land use change attributed to new Chinese agriculture policy is attracting many researchers to focus. The objective of this study is to present a more straightforward multiyear classification methodology using time series MODIS EVI with 250 meters spatial resolution and subsequent field data in Xinjiang, China. An extensive polygon based ground reference annual crop data were collected for the years 2011, 2012 and 2013 throughout the study area. The most pure pixel within each polygon was selected which eases crop differentiation. Artificial Immune Network (ABNet) was used to classify cotton, maize, wheat/others, rice and grapes, dominating most of the study area. The data of two different years were used together to classify the crop of next year, as 2011 and 2012 were used to classify crops of 2013. Classification results were validated using the same year ground data. Results showed the classification accuracy above 80% for each year with kappa coefficient of 0. 7 and above. However more research and additional ground reference data are needed to classify a range of crops in the study area which will give a more detailed view of the land use land cover change strengthening agriculture decisions practices in the future. PMID:26415458

  8. Linking Biological Responses of Terrestrial N Eutrophication to the Final Ecosystem Goods and Services Classification System

    Science.gov (United States)

    Bell, M. D.; Clark, C.; Blett, T.

    2015-12-01

    The response of a biological indicator to N deposition can indicate that an ecosystem has surpassed a critical load and is at risk of significant change. The importance of this exceedance is often difficult to digest by policy makers and public audiences if the change is not linked to a familiar ecosystem endpoint. A workshop was held to bring together scientists, resource managers, and policy makers with expertise in ecosystem functioning, critical loads, and economics in an effort to identify the ecosystem services impacted by air pollution. This was completed within the framework of the Final Ecosystem Goods and Services (FEGS) Classification System to produce a product that identified distinct interactions between society and the effects of nitrogen pollution. From each change in a biological indicator, we created multiple ecological production functions to identify the cascading effects of the change to a measureable ecosystem service that a user interacts with either by enjoying, consuming, or appreciating the good or service, or using it as an input in the human economy. This FEGS metric was then linked to a beneficiary group that interacts with the service. Chains detailing the links from the biological indicator to the beneficiary group were created for aquatic and terrestrial acidification and eutrophication at the workshop, and here we present a subset of the workshop results by highlighting for 9 different ecosystems affected by terrestrial eutrophication. A total of 213 chains that linked to 37 unique FEGS metrics and impacted 15 beneficiary groups were identified based on nitrogen deposition mediated changes to biological indicators. The chains within each ecosystem were combined in flow charts to show the complex, overlapping relationships among biological indicators, ecosystem services, and beneficiary groups. Strength of relationship values were calculated for each chain based on support for the link in the scientific literature. We produced the

  9. Improved design provides faster response time in photomultiplier

    Science.gov (United States)

    1966-01-01

    Dynamic Crossed-Field Electron Multiplying /DCFEM/ light demodulator avoids the normal response time limitations inherent in static field devices by using time varying crossed electric and static magnetic fields. This eliminates the transit time spread that affects electrons as they proceed along the secondary emission stages of the tube.

  10. Measurement of linearity and time response parameters for photomultiplier tube

    International Nuclear Information System (INIS)

    In this paper, methods of testing linearity and time response parameters of photomultiplier tube are introduced and illustrated. Two ways of measuring the maximum anode impulse current of photomultiplier tube are contrasted. Suitable scopes of these two methods are acquired under different circumstances. At the same time, the electron transit time of photomultiplier tube is obtained by means of cable delays. (authors)

  11. Thermal emittance and response time of a cesium antimonide photocathode

    Science.gov (United States)

    Cultrera, Luca; Bazarov, Ivan; Bartnik, Adam; Dunham, Bruce; Karkare, Siddharth; Merluzzi, Richard; Nichols, Matthew

    2011-10-01

    Measurements of the intrinsic emittance and response time of a Cs3Sb photocathode are presented. The emittance is obtained with a solenoid scan technique using a high voltage dc photoemission gun. Photoemission response time is evaluated using a RF deflecting cavity synchronized to a picosecond laser pulse train. We find that Cs3Sb has both small mean transverse energy, 160 ± 10 meV at 532 nm laser wavelength, and a prompt response time (below the resolution of our measurement) making it a suitable material for high brightness electron photoinjectors.

  12. Distinguishing Fast and Slow Processes in Accuracy - Response Time Data.

    Directory of Open Access Journals (Sweden)

    Frederik Coomans

    Full Text Available We investigate the relation between speed and accuracy within problem solving in its simplest non-trivial form. We consider tests with only two items and code the item responses in two binary variables: one indicating the response accuracy, and one indicating the response speed. Despite being a very basic setup, it enables us to study item pairs stemming from a broad range of domains such as basic arithmetic, first language learning, intelligence-related problems, and chess, with large numbers of observations for every pair of problems under consideration. We carry out a survey over a large number of such item pairs and compare three types of psychometric accuracy-response time models present in the literature: two 'one-process' models, the first of which models accuracy and response time as conditionally independent and the second of which models accuracy and response time as conditionally dependent, and a 'two-process' model which models accuracy contingent on response time. We find that the data clearly violates the restrictions imposed by both one-process models and requires additional complexity which is parsimoniously provided by the two-process model. We supplement our survey with an analysis of the erroneous responses for an example item pair and demonstrate that there are very significant differences between the types of errors in fast and slow responses.

  13. Distinguishing Fast and Slow Processes in Accuracy - Response Time Data.

    Science.gov (United States)

    Coomans, Frederik; Hofman, Abe; Brinkhuis, Matthieu; van der Maas, Han L J; Maris, Gunter

    2016-01-01

    We investigate the relation between speed and accuracy within problem solving in its simplest non-trivial form. We consider tests with only two items and code the item responses in two binary variables: one indicating the response accuracy, and one indicating the response speed. Despite being a very basic setup, it enables us to study item pairs stemming from a broad range of domains such as basic arithmetic, first language learning, intelligence-related problems, and chess, with large numbers of observations for every pair of problems under consideration. We carry out a survey over a large number of such item pairs and compare three types of psychometric accuracy-response time models present in the literature: two 'one-process' models, the first of which models accuracy and response time as conditionally independent and the second of which models accuracy and response time as conditionally dependent, and a 'two-process' model which models accuracy contingent on response time. We find that the data clearly violates the restrictions imposed by both one-process models and requires additional complexity which is parsimoniously provided by the two-process model. We supplement our survey with an analysis of the erroneous responses for an example item pair and demonstrate that there are very significant differences between the types of errors in fast and slow responses. PMID:27167518

  14. Real-time distributed fiber optic sensor for security systems: Performance, event classification and nuisance mitigation

    Science.gov (United States)

    Mahmoud, Seedahmed S.; Visagathilagar, Yuvaraja; Katsifolis, Jim

    2012-09-01

    The success of any perimeter intrusion detection system depends on three important performance parameters: the probability of detection (POD), the nuisance alarm rate (NAR), and the false alarm rate (FAR). The most fundamental parameter, POD, is normally related to a number of factors such as the event of interest, the sensitivity of the sensor, the installation quality of the system, and the reliability of the sensing equipment. The suppression of nuisance alarms without degrading sensitivity in fiber optic intrusion detection systems is key to maintaining acceptable performance. Signal processing algorithms that maintain the POD and eliminate nuisance alarms are crucial for achieving this. In this paper, a robust event classification system using supervised neural networks together with a level crossings (LCs) based feature extraction algorithm is presented for the detection and recognition of intrusion and non-intrusion events in a fence-based fiber-optic intrusion detection system. A level crossings algorithm is also used with a dynamic threshold to suppress torrential rain-induced nuisance alarms in a fence system. Results show that rain-induced nuisance alarms can be suppressed for rainfall rates in excess of 100 mm/hr with the simultaneous detection of intrusion events. The use of a level crossing based detection and novel classification algorithm is also presented for a buried pipeline fiber optic intrusion detection system for the suppression of nuisance events and discrimination of intrusion events. The sensor employed for both types of systems is a distributed bidirectional fiber-optic Mach-Zehnder (MZ) interferometer.

  15. A Comparison of the Classification of Disparate Malware Collected in Different Time Periods

    Directory of Open Access Journals (Sweden)

    Rafiqul Islam

    2012-06-01

    Full Text Available It has been argued that an anti-virus strategy based on malware collected at a certain date, will not work at a later date because malware evolves rapidly and an anti-virus engine is then faced with a completely new type of executable not as amenable to detection as the first was.In this paper, we test this idea by collecting two sets of malware, the first from 2002 to 2007, the second from 2009 to 2010 to determine how well the anti-virus strategy we developed based on the earlier set [18] will do on the later set. This anti-virus strategy integrates dynamic and static features extracted from the executables to classify malware by distinguishing between families. We also perform another test, to investigate the same idea whereby we accumulate all the malware executables in the old and new dataset, separately, and apply a malware versus cleanware classification.The resulting classification accuracies are very close for both datasets, with a difference of approximately 5.4% for both experiments, the older malware being more accurately classified than the newer malware. This leads us to conjecture that current anti-virus strategies can indeed be modified to deal effectively with new malware.

  16. Computerized Classification Testing under the One-Parameter Logistic Response Model with Ability-Based Guessing

    Science.gov (United States)

    Wang, Wen-Chung; Huang, Sheng-Yun

    2011-01-01

    The one-parameter logistic model with ability-based guessing (1PL-AG) has been recently developed to account for effect of ability on guessing behavior in multiple-choice items. In this study, the authors developed algorithms for computerized classification testing under the 1PL-AG and conducted a series of simulations to evaluate their…

  17. Linear Discriminant Analysis Achieves High Classification Accuracy for the BOLD fMRI Response to Naturalistic Movie Stimuli.

    Science.gov (United States)

    Mandelkow, Hendrik; de Zwart, Jacco A; Duyn, Jeff H

    2016-01-01

    Naturalistic stimuli like movies evoke complex perceptual processes, which are of great interest in the study of human cognition by functional MRI (fMRI). However, conventional fMRI analysis based on statistical parametric mapping (SPM) and the general linear model (GLM) is hampered by a lack of accurate parametric models of the BOLD response to complex stimuli. In this situation, statistical machine-learning methods, a.k.a. multivariate pattern analysis (MVPA), have received growing attention for their ability to generate stimulus response models in a data-driven fashion. However, machine-learning methods typically require large amounts of training data as well as computational resources. In the past, this has largely limited their application to fMRI experiments involving small sets of stimulus categories and small regions of interest in the brain. By contrast, the present study compares several classification algorithms known as Nearest Neighbor (NN), Gaussian Naïve Bayes (GNB), and (regularized) Linear Discriminant Analysis (LDA) in terms of their classification accuracy in discriminating the global fMRI response patterns evoked by a large number of naturalistic visual stimuli presented as a movie. Results show that LDA regularized by principal component analysis (PCA) achieved high classification accuracies, above 90% on average for single fMRI volumes acquired 2 s apart during a 300 s movie (chance level 0.7% = 2 s/300 s). The largest source of classification errors were autocorrelations in the BOLD signal compounded by the similarity of consecutive stimuli. All classifiers performed best when given input features from a large region of interest comprising around 25% of the voxels that responded significantly to the visual stimulus. Consistent with this, the most informative principal components represented widespread distributions of co-activated brain regions that were similar between subjects and may represent functional networks. In light of these

  18. The Importance of Responsibility in Times of Crisis

    OpenAIRE

    Jacob Dahl Rendtorff

    2014-01-01

    In this paper I would like to show the importance of the concept of responsibility as the foundation of ethics in times of crisis in particular in the fields of politics and economics in the modern civilisation marked by globalization and technological progres. I consider the concept of responsibility as the key notion in order to understand the ethical duty in a modern technological civilisation. We can indeed observe a moralization of the concept of responsibility going beyond a strict lega...

  19. 45 CFR 612.5 - Timing of responses to requests.

    Science.gov (United States)

    2010-10-01

    ... AVAILABILITY OF RECORDS AND INFORMATION § 612.5 Timing of responses to requests. (a) In general. NSF ordinarily... physical safety of an individual; or (B) An urgency to inform the public about an actual or alleged...

  20. Congestion Service Facilities Location Problem with Promise of Response Time

    Directory of Open Access Journals (Sweden)

    Dandan Hu

    2013-01-01

    Full Text Available In many services, promise of specific response time is advertised as a commitment by the service providers for the customer satisfaction. Congestion on service facilities could delay the delivery of the services and hurts the overall satisfaction. In this paper, congestion service facilities location problem with promise of response time is studied, and a mixed integer nonlinear programming model is presented with budget constrained. The facilities are modeled as M/M/c queues. The decision variables of the model are the locations of the service facilities and the number of servers at each facility. The objective function is to maximize the demands served within specific response time promised by the service provider. To solve this problem, we propose an algorithm that combines greedy and genetic algorithms. In order to verify the proposed algorithm, a lot of computational experiments are tested. And the results demonstrate that response time has a significant impact on location decision.

  1. Time domain modeling of tunable response of graphene

    DEFF Research Database (Denmark)

    Prokopeva, Ludmila; Emani, Naresh K.; Boltasseva, Alexandra;

    2013-01-01

    We present a causal numerical model for time domain simulations of the optical response of graphene. The dielectric function is approximated with a conductivity term, a Drude term and a number of the critical points terms....

  2. Computer based classification of MR scans in first time applicant Alzheimer patients.

    Science.gov (United States)

    Polat, Fatma; Demirel, Selcuk Orhan; Kitis, Omer; Simsek, Fatma; Haznedaroglu, Damla Isman; Coburn, Kerry; Kumral, Emre; Gonul, Ali Saffet

    2012-09-01

    In this study, we aimed to classify MR images for recognizing Alzheimer Disease (AD) in a group of patients who were recently diagnosed by clinical history and neuropsychiatric exams by using non-biased machine-learning techniques. T1 weighted MRI scans of 31 patients with probable AD and 31 age- and gender-matched cognitively normal elderly were analyzed with voxel-based morphometry and classified by support vector machine (SVM), a machine learning technique. SVM could differentiate patients from controls with accuracy of 74% (sensitivity: 70% and specificity: 77%) when the whole brain was included the analyses. The classification accuracy was increased to 79% (sensitivity: 65 % and specificity: 93%) when the analyses restricted to hippocampus. Our results showed that SVM is a promising tool for diagnosis of AD, but needed to be improved. PMID:22299620

  3. Heterogeneous CMOS/memristor hardware neural networks for real-time target classification

    Science.gov (United States)

    Merkel, Cory; Kudithipudi, Dhireesha; Ptucha, Ray

    2014-05-01

    The advent of nanoscale metal-insulator-metal (MIM) structures with memristive properties has given birth to a new generation of hardware neural networks based on CMOS/memristor integration (CMHNNs). The advantage of the CMHNN paradigm compared to a pure CMOS approach lies in the multi-faceted functionality of memristive devices: They can efficiently store neural network configurations (weights and activation function parameters) via non-volatile, quasi-analog resistance states. They also provide high-density interconnects between neurons when integrated into 2-D and 3-D crossbar architectures. In this work, we explore the combination of CMHNN classifiers with manifold learning to reduce the dimensionality of CMHNN inputs. This allows the size of the CMHNN to be reduced significantly (by ≍ 97%). We tested the proposed system using the Caltech101 database and were able to achieve classification accuracies within ≍ 1:5% of those produced by a traditional support vector machine.

  4. Time Series Analysis of Temporal Data by Classification using Mean Absolute Error

    Directory of Open Access Journals (Sweden)

    Swati Soni

    2012-09-01

    Full Text Available There has been a lot of research on the application ofdata mining and knowledge discovery technologies into financialmarket prediction area. However, most of the existing researchfocused on mining structured or numeric data such as financialreports, historical quotes, etc. Another kind of data source –unstructured data such as financial news articles, comments onfinancial markets by experts, etc., which is usually of a muchhigher availability, seems to be neglected due to theirinconvenience to be represented as numeric feature vectors forfurther applying data mining algorithms. A new hybrid systemhas been developed for this purpose. It retrieves financial newsarticles from the internet periodically and using classificationmining techniques to categorize those articles into differentcategories according to their expected effects on the marketbehaviors, then the results will be compared with the real marketdata. This classification with 10 cross fold validation combinationof algorithms can be applied to do financial market prediction in the future

  5. Femtosecond response time measurements of a Cs2Te photocathode

    CERN Document Server

    Aryshev, A; Honda, Y; Terunuma, N; Urakawa, J

    2015-01-01

    We present the response time measurements of a Cs2Te photocathode illuminated with two 100 fs duration, variable time separation laser pulses at 266 nm wavelength. The response time was confirmed in dispersive region downstream of a 12-cell standing wave S-band acceleration structure using a well-known RF zero-crossing technique. At the same time it was also measured by changing mechanical path-length difference between two micro-bunches. Both methods agree that Cs2Te photocathode time response is of the order of 250 fs and thereby it is possible to generate and control a THz sequence of relativistic electron bunches by a conventional S-band RF gun. This result further opens a possibility to construct wide-range tunable THz FEL.

  6. Time response of temperature sensors using neural networks

    International Nuclear Information System (INIS)

    Primary coolant RTDs (Resistance Temperature Detector) typically feed the plant's control and safety systems and must, therefore, be very accurate and have good dynamic performance. The response time of RTDs has been characterized by a single parameter called the time constant defined as the time it takes for the sensor output to achieve 63.2 percent of its final value after a step change in temperature. This step change is typically achieved by suddenly immersing the sensor in a rotating tank of water, called Plunge Test. In nuclear reactors, however, plunge testing is inconvenient because nuclear reactor service conditions are difficult to reproduce in the laboratory. An in-situ test method called LCSR - Loop Current Step Response test was developed to measure remotely the response time of RTDs. In the LCSR method, the response time of the sensor is identified by means of the LCSR transformation that involves the dynamic response modal time constants determination using a nodal heat-transfer model. For this reason, this calculation is not simple and requires specialized personnel. This work combines the two methodologies, Plunge test and LCSR test, using neural networks. With the use of neural networks it will not be necessary to use the LCSR transformation to determine sensor's time constant and this leads to more robust results. (author)

  7. Time response of temperature sensors using neural networks

    International Nuclear Information System (INIS)

    In a PWR nuclear power plant, the primary coolant temperature and feedwater temperature are measured using RTDs (Resistance Temperature Detectors). These RTDs typically feed the plant's control and safety systems and must, therefore, be very accurate and have good dynamic performance. The response time of RTDs is characterized by a single parameter called the Plunge Time Constant defined as the time it takes the sensor output to achieve 63.2 percent of its final value after a step change in temperature. Nuclear reactor service conditions are difficult to reproduce in the laboratory, and an in-situ test method called LCSR (Loop Current Step Response) test was developed to measure remotely the response time of RTDs. >From this test, the time constant of the sensor is identified by means of the LCSR transformation that involves the dynamic response modal time constants determination using a nodal heat-transfer model. This calculation is not simple and requires specialized personnel. For this reason an Artificial Neural Network has been developed to predict the time constant of RTD from LCSR test transient. It eliminates the transformations involved in the LCSR application. A series of LCSR tests on RTDs generates the response transients of the sensors, the input data of the networks. Plunge tests are used to determine the time constants of the RTDs, the desired output of the ANN, trained using these sets of input/output data. This methodology was firstly applied to theoretical data simulating 10 RTDs with different time constant values, resulting in an average error of about 0.74 %. Experimental data from three different RTDs was used to predict time constant resulting in a maximum error of 3,34 %. The time constants values predicted from ANN were compared with those obtained from traditional way resulting in an average error of about 18 % and that shows the network is able to predict accurately the sensor time constant. (author)

  8. Conceptual Question Response Times in Peer Instruction Classrooms

    Science.gov (United States)

    Miller, Kelly; Lasry, Nathaniel; Lukoff, Brian; Schell, Julie; Mazur, Eric

    2014-01-01

    Classroom response systems are widely used in interactive teaching environments as a way to engage students by asking them questions. Previous research on the time taken by students to respond to conceptual questions has yielded insights on how students think and change conceptions. We measure the amount of time students take to respond to…

  9. An enhanced algorithm for knee joint sound classification using feature extraction based on time-frequency analysis.

    Science.gov (United States)

    Kim, Keo Sik; Seo, Jeong Hwan; Kang, Jin U; Song, Chul Gyu

    2009-05-01

    Vibroarthrographic (VAG) signals, generated by human knee movement, are non-stationary and multi-component in nature and their time-frequency distribution (TFD) provides a powerful means to analyze such signals. The objective of this paper is to improve the classification accuracy of the features, obtained from the TFD of normal and abnormal VAG signals, using segmentation by the dynamic time warping (DTW) and denoising algorithm by the singular value decomposition (SVD). VAG and knee angle signals, recorded simultaneously during one flexion and one extension of the knee, were segmented and normalized at 0.5 Hz by the DTW method. Also, the noise within the TFD of the segmented VAG signals was reduced by the SVD algorithm, and a back-propagation neural network (BPNN) was used to classify the normal and abnormal VAG signals. The characteristic parameters of VAG signals consist of the energy, energy spread, frequency and frequency spread parameter extracted by the TFD. A total of 1408 segments (normal 1031, abnormal 377) were used for training and evaluating the BPNN. As a result, the average classification accuracy was 91.4 (standard deviation +/-1.7) %. The proposed method showed good potential for the non-invasive diagnosis and monitoring of joint disorders such as osteoarthritis. PMID:19217685

  10. Phase information of time-frequency transforms as a key feature for classification of atrial fibrillation episodes

    International Nuclear Information System (INIS)

    Patients suffering from atrial fibrillation can be classified into different subtypes, according to the temporal pattern of the arrhythmia and its recurrence. Nowadays, clinicians cannot differentiate a priori between the different subtypes, and patient classification is done afterwards, when its clinical course is available. In this paper we present a comparison of classification performances when differentiating paroxysmal and persistent atrial fibrillation episodes by means of support vector machines. We analyze short surface electrocardiogram recordings by extracting modulus and phase features from several time-frequency transforms: short-time Fourier transform, Wigner–Ville, Choi–Williams, Stockwell transform, and general Fourier-family transform. Overall, accuracy higher than 81% is obtained when classifying phase information features of real test ECGs from a heterogeneous cohort of patients (in terms of progression of the arrhythmia and antiarrhythmic treatment) recorded in a tertiary center. Therefore, phase features can facilitate the clinicians’ choice of the most appropriate treatment for each patient by means of a non-invasive technique (the surface ECG). (paper)

  11. Study on proliferation time and response time for proliferation resistance evaluation

    International Nuclear Information System (INIS)

    'Proliferation time' is one of the proliferation resistance measures adopted by the Generation IV Nuclear Energy Systems International Forum (GIF) Proliferation Resistance and Physical Protection (PR and PP) evaluation methodology. A longer proliferation time would provide the international society with more time to intervene politically in order to dissuade the State from completing its nuclear weapons program. A longer proliferation time would therefore contribute to the enhancement of proliferation resistance of a given nuclear energy system. Two methods are considered for judging whether the proliferation time is long enough: 1) comparison of the proliferation times between a reference nuclear energy system and the subject system, and 2) comparison between the proliferation time and the response time, which can be defined as the time available to the international society to make a political intervention. This paper focuses on the latter method and examines how the response time can be estimated by reviewing prior incidents. (author)

  12. Response Time Optimization for Replica Selection Service in Data Grids

    Directory of Open Access Journals (Sweden)

    Husni H.E. AL-Mistarihi

    2008-01-01

    Full Text Available Problem Statement: Data Grid architecture provides a scalable infrastructure for grid services in order to manage data files and their corresponding replicas that were distributed across the globe. The grid services are designed to support a variety of data grid applications (jobs and projects. Replica selection is a high-level service that chooses a replica location from among many distributed replicas with the minimum response time for the users' jobs. Estimating the response time accurately in the grid environment is not an easy task. The current systems expose high response time in selecting the required replicas because the response time is estimated by considering the data transfer time only. Approach: We proposed a replica selection system that selects the best replica location for the users' running jobs in a minimum response time that can be estimated by considering new factors besides the data transfer time, namely, the storage access latency and the replica requests that waiting in the storage queue. Results: The performance of the proposed system was compared with a similar system that exists in the literature namely, SimpleOptimiser. The simulation results demonstrated that our system performed better than the SimpleOptimiser on an average of 6%. Conclusions: The proposed system can select the best replica location in a lesser response time than the SimpleOptimise. The efficiency of the proposed system is 6% higher than the SimpleOptimise. The efficiency level has a high impact on the quality of service that is perceived by grid users in a data grid environment where the data files are relatively big. For example, the data files produced from the scientific applications are of the size hundreds of Terabytes.

  13. Speed-Accuracy Response Models: Scoring Rules Based on Response Time and Accuracy

    Science.gov (United States)

    Maris, Gunter; van der Maas, Han

    2012-01-01

    Starting from an explicit scoring rule for time limit tasks incorporating both response time and accuracy, and a definite trade-off between speed and accuracy, a response model is derived. Since the scoring rule is interpreted as a sufficient statistic, the model belongs to the exponential family. The various marginal and conditional distributions…

  14. Reduced computational cost in the calculation of worst case response time for real time systems

    OpenAIRE

    Urriza, José M.; Schorb, Lucas; Orozco, Javier D.; Cayssials, Ricardo

    2009-01-01

    Modern Real Time Operating Systems require reducing computational costs even though the microprocessors become more powerful each day. It is usual that Real Time Operating Systems for embedded systems have advance features to administrate the resources of the applications that they support. In order to guarantee either the schedulability of the system or the schedulability of a new task in a dynamic Real Time System, it is necessary to know the Worst Case Response Time of the Real Time tasks ...

  15. Transient electromagnetic responses during the transmitter on-time

    Science.gov (United States)

    Schultz, Gregory M.; Miller, Jonathan S.; Song, Lin-Ping; Pasion, Leonard

    2010-04-01

    Current time-domain electromagnetic induction instruments generally only utilize data acquired after the cessation of the transmitted field. During this "off time", signals are dominated by induced eddy currents and magnetic surface modes, but do not fully capture the magnetostatic response of permeable and conductive metallic ordnance. In this paper, we investigate the response of EMI systems that measure signals during excitation of the primary magnetic field (the so-called "on-time"). Our analysis shows that on-time signals have great potential to yield useful information that is not often exploited in current EMI systems. We compare analytical models to data from state-of-the-art time-domain EM sensors that have the capability to sample receivers during the on-time. We present modeling results that represent the responses from different current ramps and on-time waveforms for objects and ground. We consider target and clutter objects and grounds having a range of material properties, shapes and sizes, and configurations and investigate signal processing and inversion methods for target detection and discrimination. Specifically, correlations between on-time and off-time signals are shown to be a powerful tool for discriminating ferrous and non-ferrous metallic objects.

  16. A Phenology-Based Classification of Time-Series MODIS Data for Rice Crop Monitoring in Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen-Thanh Son

    2013-12-01

    Full Text Available Rice crop monitoring is an important activity for crop management. This study aimed to develop a phenology-based classification approach for the assessment of rice cropping systems in Mekong Delta, Vietnam, using Moderate Resolution Imaging Spectroradiometer (MODIS data. The data were processed from December 2000, to December 2012, using empirical mode decomposition (EMD in three main steps: (1 data pre-processing to construct the smooth MODIS enhanced vegetation index (EVI time-series data; (2 rice crop classification; and (3 accuracy assessment. The comparisons between the classification maps and the ground reference data indicated overall accuracies and Kappa coefficients, respectively, of 81.4% and 0.75 for 2002, 80.6% and 0.74 for 2006 and 85.5% and 0.81 for 2012. The results by comparisons between MODIS-derived rice area and rice area statistics were slightly overestimated, with a relative error in area (REA from 0.9–15.9%. There was, however, a close correlation between the two datasets (R2 ≥ 0.89. From 2001 to 2012, the areas of triple-cropped rice increased approximately 31.6%, while those of the single-cropped rain-fed rice, double-cropped irrigated rice and double-cropped rain-fed rice decreased roughly −5.0%, −19.2% and −7.4%, respectively. This study demonstrates the validity of such an approach for rice-crop monitoring with MODIS data and could be transferable to other regions.

  17. Classification of fall in sick times of liver cirrhosis using magnetic resonance image

    International Nuclear Information System (INIS)

    In this paper, I proposed a classifier of liver cirrhotic step using T1-weighted MRI (magnetic resonance imaging) and hierarchical neural network. The data sets for classification of each stage, which were normal, 1 type, 2 type and 3 type, were obtained in Pusan National University Hospital from June 2001 to December 2001. And the number of data was 46. We extracted liver region and nodule region from T1-weighted MR liver image. Then objective interpretation classifier of liver cirrhotic steps in T1-weighted MR liver images. Liver cirrhosis classifier implemented using hierarchical neural network which gray-level analysis and texture feature descriptors to distinguish normal liver and 3 types of liver cirrhosis. Then proposed Neural network classifier learned through error back-propagation algorithm. A classifying result shows that recognition rate of normal is 100%, 1 type is 82.3%, 2 type is 86.7%, 3 type is 83.7%. The recognition ratio very high, when compared between the result of obtained quantified data to that of doctors decision data and neural network classifier value. If enough data is offered and other parameter is considered, this paper according to we expected that neural network as well as human experts and could be useful as clinical decision support tool for liver cirrhosis patients

  18. Real-time multisensor data fusion for target detection, classification, tracking, counting, and range estimates

    Science.gov (United States)

    Tsui, Eddy K.; Thomas, Russell L.

    2004-09-01

    As part of the Commanding General of Army Material Command's Research, Development & Engineering Command (RDECOM), the U.S. Army Research Development and Engineering Center (ARDEC), Picatinny funded a joint development effort with McQ Associates, Inc. to develop an Advanced Minefield Sensor (AMS) as a technology evaluation prototype for the Anti-Personnel Landmine Alternatives (APLA) Track III program. This effort laid the fundamental groundwork of smart sensors for detection and classification of targets, identification of combatant or noncombatant, target location and tracking at and between sensors, fusion of information across targets and sensors, and automatic situation awareness to the 1st responder. The efforts have culminated in developing a performance oriented architecture meeting the requirements of size, weight, and power (SWAP). The integrated digital signal processor (DSP) paradigm is capable of computing signals from sensor modalities to extract needed information within either a 360° or fixed field of view with acceptable false alarm rate. This paper discusses the challenges in the developments of such a sensor, focusing on achieving reasonable operating ranges, achieving low power, small size and low cost, and applications for extensions of this technology.

  19. Low grade glioma - extent and timing of response to radiotherapy

    International Nuclear Information System (INIS)

    Purpose/Objective: While postoperative radiotherapy has been suggested to improve survival in patients with subtotally resected low grade gliomas, their rate of radiographic response and correlation of response with outcome has not been well documented. Material and Methods: Twenty adults with non-pilocytic, supratentorial low grade gliomas treated between 1988-1995 who had measurable residual tumor after surgery and complete followup imaging were analysed for radiographic response to radiotherapy. The degree and timing of response to radiation were determined by comparing tumor volumes on post-operative/pre-radiation; post-radiation and subsequent follow-up CT scans. Radiographic response to radiotherapy was correlated with clinical symptomatology and progression free survival. Results: Median postoperative/pre-radiotherapy tumor volume was 32.5 cm3. At the time of maximal response post radiotherapy, volumes were reduced to a median of 13.5 cm3 for a median volume decrease of 7.5 cm3. Tumor response was judged as complete in(3(20)) , partial in (7(20)), minor in (6(20)) and stable in (4(20)) for an overall response rate of (16(20)) (80%). Of the 16 patients responding to radiotherapy, maximal response was seen on the first follow-up scan in 15 (median time to follow-up scan was 2.8 months following initiation of radiation treatments). Only one tumor had a protracted response, continuing to decrease in size between the end of radiation treatment and approximately 18 months later. A greater proportion of those patients exhibiting a response to radiation had an improvement in clinical symptomatology ((7(16))) versus non-responders ((0(4))). There were (5(20)) patients who developed recurrent tumor at a median of 32 months post-radiation for an actuarial 5 year progression free survival of 75%. All 5 who recurred had demonstrated an initial response to radiotherapy and all recurrences were within the previously radiated field. On univariate analysis of progression

  20. It's time to set some standards: Environmental classification of freshwater wetlands in New Zealand and their protection from eutrophication

    DEFF Research Database (Denmark)

    Sorrell, Brian Keith; Clarkson, Beverly

    loading. We have developed a database of physico-chemical, nutrient and species composition information for over 100 freshwater New Zealand wetlands, ranging from true rainwater-fed bogs to relatively fertile swamps and marshes. In this presentation, we use these data to describe the range of trophic......Most natural resource plans provide protection for lakes and rivers from catchment activities leading to eutrophication. However, they are often silent about wetlands, due to the lack of information available for setting standards, defining reference conditions, and predicting responses to nutrient...... states in New Zealand wetlands, present an environmental classification based on physico-chemical and nutrient data, compare wetlands in New Zealand with those in other temperate regions, and argue for some catchment land use standards to protect wetlands from nutrient enrichment. Our database reveals...

  1. The physics of space and time III: Classification of space-time experiments and the twin paradox

    CERN Document Server

    Field, J H

    2008-01-01

    A nomenclature for inertial frames and a notation for space and time coordinates is proposed to give an unambigous description of space-time experiments in special relativity. Of particular importance are the concepts of `base' and `travelling' frames and `primary' and `reciprocal' experiments. A detailed discussion of the twin paradox is presented. The physical basis of the differential aging effect is found to be a relativistic relative-velocity transformation relation, not, as hitherto supposed, the spurious `length contraction' effect.

  2. Spectral-spatial classification of n-dimensional images in real-time based on segmentation and mathematical morphology on GPUs

    OpenAIRE

    Quesada Barriuso, Pablo

    2015-01-01

    The objective of this thesis is to develop efficient schemes for spectral-spatial n-dimensional image classification. By efficient schemes, we mean schemes that produce good classification results in terms of accuracy, as well as schemes that can be executed in real-time on low-cost computing infrastructures, such as the Graphics Processing Units (GPUs) shipped in personal computers. The n-dimensional images include images with two and three dimensions, such as images coming from ...

  3. The Time Is Right for a New Classification System for Diabetes: Rationale and Implications of the β-Cell-Centric Classification Schema.

    Science.gov (United States)

    Schwartz, Stanley S; Epstein, Solomon; Corkey, Barbara E; Grant, Struan F A; Gavin, James R; Aguilar, Richard B

    2016-02-01

    The current classification system presents challenges to the diagnosis and treatment of patients with diabetes mellitus (DM), in part due to its conflicting and confounding definitions of type 1 DM, type 2 DM, and latent autoimmune diabetes of adults (LADA). The current schema also lacks a foundation that readily incorporates advances in our understanding of the disease and its treatment. For appropriate and coherent therapy, we propose an alternate classification system. The β-cell-centric classification of DM is a new approach that obviates the inherent and unintended confusions of the current system. The β-cell-centric model presupposes that all DM originates from a final common denominator-the abnormal pancreatic β-cell. It recognizes that interactions between genetically predisposed β-cells with a number of factors, including insulin resistance (IR), susceptibility to environmental influences, and immune dysregulation/inflammation, lead to the range of hyperglycemic phenotypes within the spectrum of DM. Individually or in concert, and often self-perpetuating, these factors contribute to β-cell stress, dysfunction, or loss through at least 11 distinct pathways. Available, yet underutilized, treatments provide rational choices for personalized therapies that target the individual mediating pathways of hyperglycemia at work in any given patient, without the risk of drug-related hypoglycemia or weight gain or imposing further burden on the β-cells. This article issues an urgent call for the review of the current DM classification system toward the consensus on a new, more useful system. PMID:26798148

  4. The time reversal effect of the impulse response of crust

    Institute of Scientific and Technical Information of China (English)

    郑文衡; 王乘; 陈湘鹏

    2001-01-01

    In this paper, the time reversal processes of impulse response of crust are simulated by means of a dynamical finite element method (DFEM). The results indicate that a small undulating load during a long period may cause a fo-cused brevity impact in a chaos-response system. The physical principle for this phenomenon is that the wave interferes or multiples superposition. Based on this knowledge, a new view toward the mechanism for preparing and triggering an earthquake is proposed. Finally, an interpretation of crust response to the sea tides is given.

  5. Reaction-time response of a large commercial aircraft

    International Nuclear Information System (INIS)

    The reaction-time response of a large commercial aircraft is defined. The aircraft is examined as a thin-walled tubular missile. The impact is assumed soft, and the target's effect on the reaction-time response is neglected. The reaction-time response is defined assuming a normal impact on a rigid wall. The reaction-time response is defined with the analytical Riera method and with the numerical explicit finite element method. The Riera force history is solved with the finite difference method. For the finite element method, two codes are used: Abaqus/Explicit and LS-DYNA. Focus is on the sensitivity study of the used methods. The outer shell of the aircraft is modeled, and an approximation for the mass-distribution is made. Sensitivity to modeling assumptions is studied in order to get information on the adequacy of modeling. The results indicate relatively small sensitivity to modeling assumptions. The wings should be modeled more accurately in order to obtain the dominant frequency response in global structural analysis. (author)

  6. Rapid etiological classification of meningitis by NMR spectroscopy based on metabolite profiles and host response.

    Directory of Open Access Journals (Sweden)

    Uwe Himmelreich

    Full Text Available Bacterial meningitis is an acute disease with high mortality that is reduced by early treatment. Identification of the causative microorganism by culture is sensitive but slow. Large volumes of cerebrospinal fluid (CSF are required to maximise sensitivity and establish a provisional diagnosis. We have utilised nuclear magnetic resonance (NMR spectroscopy to rapidly characterise the biochemical profile of CSF from normal rats and animals with pneumococcal or cryptococcal meningitis. Use of a miniaturised capillary NMR system overcame limitations caused by small CSF volumes and low metabolite concentrations. The analysis of the complex NMR spectroscopic data by a supervised statistical classification strategy included major, minor and unidentified metabolites. Reproducible spectral profiles were generated within less than three minutes, and revealed differences in the relative amounts of glucose, lactate, citrate, amino acid residues, acetate and polyols in the three groups. Contributions from microbial metabolism and inflammatory cells were evident. The computerised statistical classification strategy is based on both major metabolites and minor, partially unidentified metabolites. This data analysis proved highly specific for diagnosis (100% specificity in the final validation set, provided those with visible blood contamination were excluded from analysis; 6-8% of samples were classified as indeterminate. This proof of principle study suggests that a rapid etiologic diagnosis of meningitis is possible without prior culture. The method can be fully automated and avoids delays due to processing and selective identification of specific pathogens that are inherent in DNA-based techniques.

  7. Automated time activity classification based on global positioning system (GPS) tracking data

    OpenAIRE

    Wu Jun; Jiang Chengsheng; Houston Douglas; Baker Dean; Delfino Ralph

    2011-01-01

    Abstract Background Air pollution epidemiological studies are increasingly using global positioning system (GPS) to collect time-location data because they offer continuous tracking, high temporal resolution, and minimum reporting burden for participants. However, substantial uncertainties in the processing and classifying of raw GPS data create challenges for reliably characterizing time activity patterns. We developed and evaluated models to classify people's major time activity patterns fr...

  8. Dynamical theory of responsivity and response time of a high temperature superconductor photo-thermoelectrical bolometer

    International Nuclear Information System (INIS)

    Dynamical theory of responsivity and response time for an high temperature superconductor (HTSC) photo-thermoelectrical bolometer is analysed in this paper. There is a thermoelectric feedback (TEF) due to the heat transfer from the sensitive area (HTSC-BiSb thermojunction) towards the cold junction of the thermocouple. This is in addition to the normal electrothermal feedback (ETF) between the detector and the substrate, in a photoelectrical bolometer. The two legs of the thermocouple are connected in a parallel geometry configuration. It is seen that TEF can be used in combination with the ETF to enhance responsivity and response time of the detector

  9. Timing criteria for supplemental BWR emergency response equipment

    International Nuclear Information System (INIS)

    The Great Tohuku Earthquake and subsequent Tsunami represented a double failure event which destroyed offsite power connections to Fukushima-Daiichi site and then destroyed on-site electrical systems needed to run decay heat removal systems. The accident could have been mitigated had there been supplemental portable battery chargers, supplemental pumps, and in-place piping connections to provide alternate decay heat removal. In response to this event in the USA, two national response centers, one in Memphis, Tennessee, and another in Phoenix, Arizona, will begin operation. They will be able to dispatch supplemental emergency response equipment to any nuclear plant in the U.S. within 24 hours. In order to define requirements for supplemental nuclear power plant emergency response equipment maintained onsite vs. in a regional support center it is necessary to confirm: (a) the earliest time such equipment might be needed depending on the specific scenario, (b) the nominal time to move the equipment from a storage location either on-site or within the region of a nuclear power plant, and (c) the time required to connect in the supplemental equipment to use it. This paper describes an evaluation process for a BWR-4 with a Mark I Containment starting with: (a) severe accident simulation to define best estimate times available for recovery based on the specific scenario, (b) identify the key supplemental response equipment needed at specific times to accomplish recovery of key safety functions, and (c) evaluate what types of equipment should be warehoused on-site vs. in regional response centers. (authors)

  10. Planck 2013 results. VII. HFI time response and beams

    CERN Document Server

    Ade, P A R; Armitage-Caplan, C; Arnaud, M; Ashdown, M; Atrio-Barandela, F; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Battaner, E; Benabed, K; Benoît, A; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bobin, J; Bock, J J; Bond, J R; Borrill, J; Bouchet, F R; Bowyer, J W; Bridges, M; Bucher, M; Burigana, C; Cardoso, J -F; Catalano, A; Challinor, A; Chamballu, A; Chary, R -R; Chiang, L -Y; Chiang, H C; Christensen, P R; Church, S; Clements, D L; Colombi, S; Colombo, L P L; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Delouis, J -M; Désert, F -X; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Dunkley, J; Dupac, X; Efstathiou, G; Enßlin, T A; Eriksen, H K; Finelli, F; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Galeotta, S; Ganga, K; Giard, M; Giraud-Héraud, Y; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Gudmundsson, J E; Haissinski, J; Hansen, F K; Hanson, D; Harrison, D; Henrot-Versillé, S; Hernández-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Hou, Z; Hovest, W; Huffenberger, K M; Jaffe, T R; Jaffe, A H; Jones, W C; Juvela, M; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Knox, L; Kunz, M; Kurki-Suonio, H; Lagache, G; Lamarre, J -M; Lasenby, A; Laureijs, R J; Lawrence, C R; Leonardi, R; Leroy, C; Lesgourgues, J; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; MacTavish, C J; Maffei, B; Mandolesi, N; Maris, M; Marshall, D J; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Matsumura, T; Matthai, F; Mazzotta, P; McGehee, P; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; Osborne, S; Oxborrow, C A; Paci, F; Pagano, L; Pajot, F; Paoletti, D; Pasian, F; Patanchon, G; Perdereau, O; Perotto, L; Perrotta, F; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polegre, A M; Polenta, G; Ponthieu, N; Popa, L; Poutanen, T; Pratt, G W; Prézeau, G; Prunet, S; Puget, J -L; Rachen, J P; Reinecke, M; Remazeilles, M; Renault, C; Ricciardi, S; Riller, T; Ristorcelli, I; Rocha, G; Rosset, C; Roudier, G; Rowan-Robinson, M; Rusholme, B; Sandri, M; Santos, D; Sauvé, A; Savini, G; Shellard, E P S; Spencer, L D; Starck, J -L; Stolyarov, V; Stompor, R; Sudiwala, R; Sureau, F; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Tavagnacco, D; Terenzi, L; Tomasi, M; Tristram, M; Tucci, M; Umana, G; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Vittorio, N; Wade, L A; Wandelt, B D; Yvon, D; Zacchei, A; Zonca, A

    2014-01-01

    This paper characterizes the effective beams,the effective beam window functions and the associated errors for the Planck HFI detectors. The effective beam is the angular response including the effect of the optics,detectors,data processing and the scan strategy. The window function is the representation of this beam in the harmonic domain which is required to recover an unbiased measurement of the CMB angular power spectrum. The HFI is a scanning instrument and its effective beams are the convolution of: (a) the optical response of the telescope and feeds;(b)the processing of the time-ordered data and deconvolution of the bolometric and electronic time response; and (c) the merging of several surveys to produce maps. The time response functions are measured using observations of Jupiter and Saturn and by minimizing survey difference residuals. The scanning beam is the post-deconvolution angular response of the instrument, and is characterized with observations of Mars. The main beam solid angles are determin...

  11. Transformation Algorithm of Dielectric Response in Time-Frequency Domain

    Directory of Open Access Journals (Sweden)

    Ji Liu

    2014-01-01

    Full Text Available A transformation algorithm of dielectric response from time domain to frequency domain is presented. In order to shorten measuring time of low or ultralow frequency dielectric response characteristics, the transformation algorithm is used in this paper to transform the time domain relaxation current to frequency domain current for calculating the low frequency dielectric dissipation factor. In addition, it is shown from comparing the calculation results with actual test data that there is a coincidence for both results over a wide range of low frequencies. Meanwhile, the time domain test data of depolarization currents in dry and moist pressboards are converted into frequency domain results on the basis of the transformation. The frequency domain curves of complex capacitance and dielectric dissipation factor at the low frequency range are obtained. Test results of polarization and depolarization current (PDC in pressboards are also given at the different voltage and polarization time. It is demonstrated from the experimental results that polarization and depolarization current are affected significantly by moisture contents of the test pressboards, and the transformation algorithm is effective in ultralow frequency of 10−3 Hz. Data analysis and interpretation of the test results conclude that analysis of time-frequency domain dielectric response can be used for assessing insulation system in power transformer.

  12. Co-movement of commodity prices – results from dynamic time warping classification

    OpenAIRE

    Śmiech, Sławomir

    2014-01-01

    Several factors are responsible for difficulties in describing the behaviour of commodity prices. Firstly, there are numerous different categories of commodities. Secondly, some categories overlap with other categories, while others indirectly compete in the market. Thirdly, although essentially commodity prices react to changes in economic conditions or exchange rates, to a large extent these prices depend on supply disturbances. However, in recent years commodity prices co-move, and researc...

  13. Phenological Classification of the United States: A Geographic Framework for Extending Multi-Sensor Time-Series Data

    Directory of Open Access Journals (Sweden)

    Willem J. D. van Leeuwen

    2010-02-01

    Full Text Available This study introduces a new geographic framework, phenological classification, for the conterminous United States based on Moderate Resolution Imaging Spectroradiometer (MODIS Normalized Difference Vegetation Index (NDVI time-series data and a digital elevation model. The resulting pheno-class map is comprised of 40 pheno-classes, each having unique phenological and topographic characteristics. Cross-comparison of the pheno-classes with the 2001 National Land Cover Database indicates that the new map contains additional phenological and climate information. The pheno-class framework may be a suitable basis for the development of an Advanced Very High Resolution Radiometer (AVHRR-MODIS NDVI translation algorithm and for various biogeographic studies.

  14. In situ response time measurements of RTD temperature sensors

    International Nuclear Information System (INIS)

    The loop-current-step-response test provides a mean for determining the time constant of resistence thermometers. The test consist in heating the sensor a few degrees above ambient temperature by causing a step pertubation in the electric current that flows through the sensor leads. The developed mathematical transformation permits to use data collected during the internal heating transient to predict the sensor response to perturbations in fluid temperature. Experimental data obtained show that the time constant determined by method is within 15 percent of true value. The loop-current-step-response test is a remote in situ test, which can be performed with the sensor installed in the process. Consequently it takes account the local heat transfer conditions, and appropriated for nuclear power plants, where sensors are installed in points of difficult access. (author)

  15. Improvement in MFTF data base system response times

    International Nuclear Information System (INIS)

    The Supervisory Control and Diagnostic System for the Mirror Fusion Test Facility (MFTF) has been designed as an event driven system. To this end we have designed a data base notification facility in which a task can request that it be loaded and started whenever an element in the data base is changed beyond some user defined range. Our initial implementation of the notify facility exhibited marginal response times whenever a data base table with a large number of outstanding notifies was written into. In this paper we discuss the sources of the slow response and describe in detail a new structure for the list of notifies which minimizes search time resulting in significantly faster response

  16. Response Times of Operators in a Control Room

    DEFF Research Database (Denmark)

    Platz, O.; Rasmussen, J.; Skanborg, Preben Zacho

    A statistical analysis was made of operator response times recorded in the control room of a research reactor during the years 1972-1974. A homogeneity test revealed that the data consist of a mixture of populations. A small but statistically significant difference is found between day and night...

  17. Mean Response Time Approximation for HTTP Transactions over Transport Protocols

    Directory of Open Access Journals (Sweden)

    Y. J. Lee

    2014-12-01

    Full Text Available This paper addresses mean response time that end-users experience when using the Internet. HTTP (Hyper Text Transfer Protocol is a widely used transfer protocol to retrieve web objects in the Internet. Generally, HTTP uses TCP (Transmission Control Protocol in a transport layer. But it is known that HTTP interacts with TCP inefficiently. As an example of such inefficiencies, HTTP does not require TCP to deliver the rigid order, which may cause head-of-line blocking. As another transport layer protocol, SCTP (Stream Control Transmission Protocol has attractive features such as multi-streaming and multi-homing unlike TCP. Within an SCTP association, multi-streaming allows for independent delivery among streams, thus can avoid the head-of-line blocking. In addition, SCTP provides very large number of streams; therefore, it can transfer multiple objects more efficiently than the typical HTTP/1.1 over TCP which limits the number of pipelines. Mean response time is one of the main measures that end users using Internet concern. This paper presents the simple analytical model and algorithm to find the mean response time for HTTP over SCTP including the previous HTTP over TCP. Some computational experiences show that the proposed model and algorithm are well approximated to the real environment. Also, it is shown that mean response time for HTTP over SCTP can be less than that for HTTP over TCP.

  18. Processing Time Shifts Affects the Execution of Motor Responses

    Science.gov (United States)

    Sell, Andrea J.; Kaschak, Michael P.

    2011-01-01

    We explore whether time shifts in text comprehension are represented spatially. Participants read sentences involving past or future events and made sensibility judgment responses in one of two ways: (1) moving toward or away from their body and (2) pressing the toward or away buttons without moving. Previous work suggests that spatial…

  19. Linear-response thermal time-dependent density functional theory

    CERN Document Server

    Pribram-Jones, Aurora; Burke, Kieron

    2015-01-01

    The van Leeuwen proof of linear-response time-dependent density functional theory (TDDFT) is generalized to thermal ensembles. This allows generalization to finite temperatures of the Gross-Kohn relation, the exchange-correlation kernel of TDDFT, and fluctuation dissipation theorem for DFT. This produces a natural method for generating new thermal exchange-correlation (XC) approximations.

  20. Automated time activity classification based on global positioning system (GPS tracking data

    Directory of Open Access Journals (Sweden)

    Wu Jun

    2011-11-01

    Full Text Available Abstract Background Air pollution epidemiological studies are increasingly using global positioning system (GPS to collect time-location data because they offer continuous tracking, high temporal resolution, and minimum reporting burden for participants. However, substantial uncertainties in the processing and classifying of raw GPS data create challenges for reliably characterizing time activity patterns. We developed and evaluated models to classify people's major time activity patterns from continuous GPS tracking data. Methods We developed and evaluated two automated models to classify major time activity patterns (i.e., indoor, outdoor static, outdoor walking, and in-vehicle travel based on GPS time activity data collected under free living conditions for 47 participants (N = 131 person-days from the Harbor Communities Time Location Study (HCTLS in 2008 and supplemental GPS data collected from three UC-Irvine research staff (N = 21 person-days in 2010. Time activity patterns used for model development were manually classified by research staff using information from participant GPS recordings, activity logs, and follow-up interviews. We evaluated two models: (a a rule-based model that developed user-defined rules based on time, speed, and spatial location, and (b a random forest decision tree model. Results Indoor, outdoor static, outdoor walking and in-vehicle travel activities accounted for 82.7%, 6.1%, 3.2% and 7.2% of manually-classified time activities in the HCTLS dataset, respectively. The rule-based model classified indoor and in-vehicle travel periods reasonably well (Indoor: sensitivity > 91%, specificity > 80%, and precision > 96%; in-vehicle travel: sensitivity > 71%, specificity > 99%, and precision > 88%, but the performance was moderate for outdoor static and outdoor walking predictions. No striking differences in performance were observed between the rule-based and the random forest models. The random forest model was fast

  1. Technical Note: Semi-automated classification of time-lapse RGB imagery for a remote Greenlandic river

    Science.gov (United States)

    Gleason, C. J.; Smith, L. C.; Finnegan, D. C.; LeWinter, A. L.; Pitcher, L. H.; Chu, V. W.

    2015-01-01

    River systems in remote environments are often challenging to monitor and understand where traditional gauging apparatus are difficult to install or where safety concerns prohibit field measurements. In such cases, remote sensing, especially terrestrial time lapse imaging platforms, offer a means to better understand these fluvial systems. One such environment is found at the proglacial Isortoq River in southwest Greenland, a river with a constantly shifting floodplain and remote Arctic location that make gauging and in situ measurements all but impossible. In order to derive relevant hydraulic parameters for this river, two RGB cameras were installed in July of 2011, and these cameras collected over 10 000 half hourly time-lapse images of the river by September of 2012. Existing approaches for extracting hydraulic parameters from RGB imagery require manual or supervised classification of images into water and non-water areas, a task that was impractical for the volume of data in this study. As such, automated image filters were developed that removed images with environmental obstacles (e.g. shadows, sun glint, snow) from the processing stream. Further image filtering was accomplished via a novel automated histogram similarity filtering process. This similarity filtering allowed successful (mean accuracy 79.6%) supervised classification of filtered images from training data collected from just 10% of those images. Effective width, a hydraulic parameter highly correlated with discharge in braided rivers, was extracted from these classified images, producing a hydrograph proxy for the Isortoq River between 2011 and 2012. This hydrograph proxy shows agreement with historic flooding observed in other parts of Greenland in July 2012 and offers promise that the imaging platform and processing methodology presented here will be useful for future monitoring studies of remote rivers.

  2. Comparison of LMFBR piping response obtained using response spectrum and time history methods

    International Nuclear Information System (INIS)

    The dynamic response to a seismic event is calculated for a piping system using a response spectrum analysis method and two time history analysis methods. The results from the analytical methods are compared to identify causes for the differences between the sets of analytical results. Comparative methods are also presented which help to gain confidence in the accuracy of the analytical methods in predicting piping system structure response during seismic events

  3. Aircraft Fault Detection Using Real-Time Frequency Response Estimation

    Science.gov (United States)

    Grauer, Jared A.

    2016-01-01

    A real-time method for estimating time-varying aircraft frequency responses from input and output measurements was demonstrated. The Bat-4 subscale airplane was used with NASA Langley Research Center's AirSTAR unmanned aerial flight test facility to conduct flight tests and collect data for dynamic modeling. Orthogonal phase-optimized multisine inputs, summed with pilot stick and pedal inputs, were used to excite the responses. The aircraft was tested in its normal configuration and with emulated failures, which included a stuck left ruddervator and an increased command path latency. No prior knowledge of a dynamic model was used or available for the estimation. The longitudinal short period dynamics were investigated in this work. Time-varying frequency responses and stability margins were tracked well using a 20 second sliding window of data, as compared to a post-flight analysis using output error parameter estimation and a low-order equivalent system model. This method could be used in a real-time fault detection system, or for other applications of dynamic modeling such as real-time verification of stability margins during envelope expansion tests.

  4. Classification of Epileptic EEG Signals using Time-Delay Neural Networks and Probabilistic Neural Networks

    Directory of Open Access Journals (Sweden)

    Ateke Goshvarpour

    2013-05-01

    Full Text Available The aim of this paper is to investigate the performance of time delay neural networks (TDNNs and the probabilistic neural networks (PNNs trained with nonlinear features (Lyapunov exponents and Entropy on electroencephalogram signals (EEG in a specific pathological state. For this purpose, two types of EEG signals (normal and partial epilepsy are analyzed. To evaluate the performance of the classifiers, mean square error (MSE and elapsed time of each classifier are examined. The results show that TDNN with 12 neurons in hidden layer result in a lower MSE with the training time of about 19.69 second. According to the results, when the sigma values are lower than 0.56, the best performance in the proposed probabilistic neural network structure is achieved. The results of present study show that applying the nonlinear features to train these networks can serve as useful tool in classifying of the EEG signals.

  5. Statistical Tests of Conditional Independence between Responses and/or Response Times on Test Items

    Science.gov (United States)

    van der Linden, Wim J.; Glas, Cees A. W.

    2010-01-01

    Three plausible assumptions of conditional independence in a hierarchical model for responses and response times on test items are identified. For each of the assumptions, a Lagrange multiplier test of the null hypothesis of conditional independence against a parametric alternative is derived. The tests have closed-form statistics that are easy to…

  6. The Time Course Effect of Moderate Intensity Exercise on Response Execution and Response Inhibition

    Science.gov (United States)

    Joyce, Jennifer; Graydon, Jan; McMorris, Terry; Davranche, Karen

    2009-01-01

    This research aimed to investigate the time course effect of a moderate steady-state exercise session on response execution and response inhibition using a stop-task paradigm. Ten participants performed a stop-signal task whilst cycling at a carefully controlled workload intensity (40% of maximal aerobic power), immediately following exercise and…

  7. Time-series classification of ELMs on NSTX with machine learning analysis

    Science.gov (United States)

    Smith, David; Fonck, R.; McKee, G.; NSTX Team

    2014-10-01

    The linear peeling-ballooning model can describe onset conditions for edge-localized modes (ELMs), but understanding saturation mechanisms and transport dynamics requires nonlinear models and experimental validation. Here, we examine time-series data of ELM bursts on NSTX to identify representative ELM groups with similar evolution characteristics. We apply hierarchical cluster analysis, an unsupervised machine learning technique popular in genomics, to beam emission spectroscopy (BES) measurements of ELM bursts. The application of cluster analysis to time-series data requires metrics to quantify the similarity or dissimilarity among time-series data. We find that both correlation and dynamic time warping similarity metrics reveal 2 groups of ELM events: fast, non-oscillatory ELMs (~200 micro-s) and slow, oscillatory ELMs (~1 ms). We also report on progress with wavelet-based similarity metrics. The identification of representative ELM groups with cluster analysis can establish validation scenarios for simulations, facilitate the automatic identification of ELMs in data, prepare ELM measurements for subsequent supervised machine learning analysis, and, more broadly, demonstrate the applicability of machine learning analysis to fusion plasma data. Supported by US Dept. of Energy Grant No. DE-SC0001288.

  8. Optical remotely sensed time series data for land cover classification: A review

    Science.gov (United States)

    Gómez, Cristina; White, Joanne C.; Wulder, Michael A.

    2016-06-01

    Accurate land cover information is required for science, monitoring, and reporting. Land cover changes naturally over time, as well as a result of anthropogenic activities. Monitoring and mapping of land cover and land cover change in a consistent and robust manner over large areas is made possible with Earth Observation (EO) data. Land cover products satisfying a range of science and policy information needs are currently produced periodically at different spatial and temporal scales. The increased availability of EO data-particularly from the Landsat archive (and soon to be augmented with Sentinel-2 data)-coupled with improved computing and storage capacity with novel image compositing approaches, have resulted in the availability of annual, large-area, gap-free, surface reflectance data products. In turn, these data products support the development of annual land cover products that can be both informed and constrained by change detection outputs. The inclusion of time series change in the land cover mapping process provides information on class stability and informs on logical class transitions (both temporally and categorically). In this review, we present the issues and opportunities associated with generating and validating time-series informed annual, large-area, land cover products, and identify methods suited to incorporating time series information and other novel inputs for land cover characterization.

  9. Epilepsy Classification Framework Utilizing Joint Time-Frequency Signal Analysis and Processing

    Directory of Open Access Journals (Sweden)

    Shiva KHOSHNOUD

    2015-06-01

    Full Text Available Time Frequency Signal Analysis and Processing (TFSAP have been proposed in order to analyse the signal in both the time and the frequency domains. Electroencephalography (EEG as a time-varying frequency signal is an interesting field in which Time Frequency Distribution (TFD could be used in order to visualize the simultaneous distributions of signal energy in different physiological and pathological brain states. Particularly, epileptic signals due to their great features of seizure activity are introduced as the most attractive research field among researchers. This study outlines an investigation on two main pathologic brain states including, pre-ictal activity and seizure activity compared to normal activity. Pseudo-Wigner -Ville and Choi-William distributions are used in order to visualize the energy content of signals in these states. Different segments of brain electrical activity are analyzed using these distributions. Finally, Renyi’s entropy as an important characteristic which offer insight towards the EEG signal processing has been extracted from TFDs. The results obtained indicate that Renyi’s entropy is a high-quality discriminative feature especially in alpha and delta sub-bands of the EEG signal.

  10. Predicting aquifer response time for application in catchment modeling.

    Science.gov (United States)

    Walker, Glen R; Gilfedder, Mat; Dawes, Warrick R; Rassam, David W

    2015-01-01

    It is well established that changes in catchment land use can lead to significant impacts on water resources. Where land-use changes increase evapotranspiration there is a resultant decrease in groundwater recharge, which in turn decreases groundwater discharge to streams. The response time of changes in groundwater discharge to a change in recharge is a key aspect of predicting impacts of land-use change on catchment water yield. Predicting these impacts across the large catchments relevant to water resource planning can require the estimation of groundwater response times from hundreds of aquifers. At this scale, detailed site-specific measured data are often absent, and available spatial data are limited. While numerical models can be applied, there is little advantage if there are no detailed data to parameterize them. Simple analytical methods are useful in this situation, as they allow the variability in groundwater response to be incorporated into catchment hydrological models, with minimal modeling overhead. This paper describes an analytical model which has been developed to capture some of the features of real, sloping aquifer systems. The derived groundwater response timescale can be used to parameterize a groundwater discharge function, allowing groundwater response to be predicted in relation to different broad catchment characteristics at a level of complexity which matches the available data. The results from the analytical model are compared to published field data and numerical model results, and provide an approach with broad application to inform water resource planning in other large, data-scarce catchments. PMID:24842053

  11. Prognostic Significance of Subtype Classification for Short- and Long-Term Survival in Breast Cancer: Survival Time Holds the Key

    OpenAIRE

    Ambs, Stefan

    2010-01-01

    Stefan Ambs provides a perspective on a recent research article by Paul Pharoah and colleagues that evaluated the prognostic significance of immunohistochemical subtype classification in early breast cancer.

  12. Data Mining and Machine-Learning in Time-Domain Discovery & Classification

    CERN Document Server

    Bloom, Joshua S

    2011-01-01

    The changing heavens have played a central role in the scientific effort of astronomers for centuries. Galileo's synoptic observations of the moons of Jupiter and the phases of Venus starting in 1610, provided strong refutation of Ptolemaic cosmology. In more modern times, the discovery of a relationship between period and luminosity in some pulsational variable stars led to the inference of the size of the Milky Way, the distance scale to the nearest galaxies, and the expansion of the Universe. Distant explosions of supernovae were used to uncover the existence of dark energy and provide a precise numerical account of dark matter. Indeed, time-domain observations of transient events and variable stars, as a technique, influences a broad diversity of pursuits in the entire astronomy endeavor. While, at a fundamental level, the nature of the scientific pursuit remains unchanged, the advent of astronomy as a data-driven discipline presents fundamental challenges to the way in which the scientific process must n...

  13. Real-Time Source Classification with an Waveform Parameter Filtering of Acoustic Emission Signals

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seung Hyun; Park, Jae Ha; Ahn, Bong Young [Chonnam National University, Gwangju (Korea, Republic of)

    2011-04-15

    The acoustic emission(AE) technique is a well established method to carry out structural health monitoring(SHM) of large structures. However, the real-time monitoring of the crack growth in the roller coaster support structures is not easy since the vehicle operation produces very large noise as well as crack growth. In this investigation, we present the waveform parameter filtering method to classify acoustic sources in real-time. This method filtrates only the AE hits by the target acoustic source as passing hits in a specific parameter band. According to various acoustic sources, the waveform parameters were measured and analyzed to verify the present filtering method. Also, the AE system employing the waveform parameter filter was manufactured and applied to the roller coaster support structure in an actual amusement park

  14. [Identification and classification of textiles based on terahertz time domain spectroscopy].

    Science.gov (United States)

    Cao, Bing-hua; Fan, Meng-bao; Jing, Sheng-yu

    2010-07-01

    A method to discriminate textiles was proposed based on terahertz time-domain spectroscopy (THz-TDS) and clustering analysis, and some typical cotton textiles were investigated to prove its feasibility. Their time domain waveforms were measured using THz-TDS system and then their absorption spectra were obtained. Principal component analysis (PCA) was applied to extract features of the data, and then Mahalanobis distance discriminant method was employed to classify these materials. The results show that this method can classify these five textiles accurately. It indicates that the method to classify textiles is feasible which combines PCA and Mahalanobis distance discriminant method based on their THz absorption spectra. The proposed method has a potential for identifying textiles of similar composition. PMID:20827962

  15. Time Series Generation and Classification of MODIS Data for Land Cover Mapping

    OpenAIRE

    Colditz, Rene Roland

    2008-01-01

    Processes of the Earth’s surface occur at different scales of time and intensity. Climate in particular determines the activity and seasonal development of vegetation. These dynamics are predominantly driven by temperature in the humid mid-latitudes and by the availability of water in semi-arid regions. Human activities are a modifying parameter for many ecosystems and can become the prime force in well-developed regions with an intensively managed environment. Accounting for these dynamics, ...

  16. Real time classification of sperm whale clicks and shipping impulses from fixed ocean observatories

    OpenAIRE

    Zaugg, Serge Alain; Schaar, Mike van der; Houegnigan, Ludwig; André, Michel

    2010-01-01

    The automated acoustic detection of cetaceans in real time is an important tool to study their behaviour and distribution and for activating mitigation measures in the context of harmful anthropogenic activities at sea. Acoustic data from the NEMO ONDE deep sea observatory (Sicily) indicated that sperm whale clicks were present in 15 % of the recordings and impulsive ship noise in 10 %. The ship noise poses a serious challenge to the detection of sperm whale clicks, since it is...

  17. Real-time classification of datasets with hardware embedded neuromorphic neural networks.

    Science.gov (United States)

    Bako, Laszlo

    2010-05-01

    Neuromorphic artificial neural networks attempt to understand the essential computations that take place in the dense networks of interconnected neurons making up the central nervous systems in living creatures. This article demonstrates that artificial spiking neural networks--built to resemble the biological model--encoding information in the timing of single spikes, are capable of computing and learning clusters from realistic data. It shows how a spiking neural network based on spike-time coding can successfully perform unsupervised and supervised clustering on real-world data. A temporal encoding procedure of continuously valued data is developed, together with a hardware implementation oriented new learning rule set. Solutions that make use of embedded soft-core microcontrollers are investigated, to implement some of the most resource-consuming components of the artificial neural network. Details of the implementations are given, with benchmark application evaluation and test bench description. Measurement results are presented, showing real-time and adaptive data processing capabilities, comparing these to related findings in the specific literature. PMID:20053732

  18. Classification of acoustic emission signals for drive systems coupling crack detection in semi-real time

    International Nuclear Information System (INIS)

    Early detection of mechanical failure in helicopter drive train components is a key safety and economical issue with both military and civil sectors of aviation. Of these components, couplings are particularly critical. The objective of this work is to demonstrate the feasibility of designing and developing a reliable, real time monitoring methodology based on Supervised Pattern Recognition (SPR) for early detection of cracks in couplings used in helicopter and engine drive systems. Within this framework, a portable Acoustic Emission (AE) system was used, equipped with a semi-real time SPR software package. Results from AE tests performed in a gearbox-testing bench at different speeds and different torque values are presented. These results indicate that the energy content of different frequency bands in the AE signals power spectra is strongly correlated with the introduction of EDM notches in the main gear. Further tests indicate that a strong shift in the frequency of the AE signals is observed after spalling occurred in the pinion gear. The variation of displacement and velocity between signal classes are discussed as a potential feature in characterizing crack severity. Finally, a scope of the work for optimizing the methodology in detecting and evaluating coupling cracking in real time will be presented. (author)

  19. Integrated inertial sensors and mobile computing for real-time cycling performance guidance via pedaling profile classification.

    Science.gov (United States)

    Xu, James Y; Nan, Xiaomeng; Ebken, Victor; Wang, Yan; Pottie, Greg J; Kaiser, William J

    2015-03-01

    Today, the bicycle is utilized as a daily commute tool, a physical rehabilitation asset, and sporting equipment, prompting studies into the biomechanics of cycling. Of the number of important parameters that affect cycling efficiency, the foot angle profile is one of the most important as it correlates directly with the effective force applied to the bike. However, there has been no compact and portable solution for measuring the foot angle and for providing the cyclist with real-time feedback due to a number of difficulties of the current tracking and sensing technologies and the myriad types of bikes available. This paper presents a novel sensing and mobile computing system for classifying the foot angle profiles during cycling and for providing real-time guidance to the user to achieve the correct profile. Continuous foot angle tracking is firstly converted into a discrete problem requiring only recognition of acceleration profiles of the foot using a single shoe mounted tri-axial accelerometer during each pedaling cycle. A classification method is then applied to identify the pedaling profile. Finally, a mobile solution is presented to provide real-time signal processing and guidance. PMID:24833607

  20. Can a time-stratigraphic classification system be developed for Venus?

    Science.gov (United States)

    Tanaka, K. L.; Schaber, G. G.

    1992-01-01

    Magellan radar images reveal that Venus' exposed geologic record covers a relatively short and recent time span, as indicated by the low density of impact craters across the planet. Therefore, because impact cratering in itself will not be a useful tool to define geologic ages on Venus, it was questioned whether a useful stratigraphic scheme can be developed for the planet. We believe that a venusian stratigraphy is possible and that it can be based on the following: (1) an examination of the rationale and methods that have been used to develop such schemes for the other planets; and (2) what can be gleaned from Magellan and other datasets of Venus.

  1. The effect of alcohol hangover on choice response time

    OpenAIRE

    Grange, JA; Stephens, R.; Jones, K; Owen, L

    2016-01-01

    The effect of alcohol hangover on cognitive processing has received little attention. We explored the effect of alcohol hangover on choice response time (RT), a dominant dependent variable (DV) in cognitive research. Prior research of the effect of hangover on RT has produced mixed findings; all studies reviewed relied exclusively on estimates of central tendency (e.g. mean RT), which has limited information value. Here we present novel analytical methods by going beyond mean RT analysis. Spe...

  2. Response Time Analysis of Distributed Web Systems Using QPNs

    Directory of Open Access Journals (Sweden)

    Tomasz Rak

    2015-01-01

    Full Text Available A performance model is used for studying distributed Web systems. Performance evaluation is done by obtaining load test measurements. Queueing Petri Nets formalism supports modeling and performance analysis of distributed World Wide Web environments. The proposed distributed Web systems modeling and design methodology have been applied in the evaluation of several system architectures under different external loads. Furthermore, performance analysis is done to determine the system response time.

  3. The time-dependence of electromagnetic response functions

    OpenAIRE

    Beamish, D.

    1982-01-01

    Dynamic processes within the Earth are capable of modifying many of its physical properties. This review considers the modification of electrical resistivity mainly by time-changes in the stress­ field experienced by crustal materials. Laboratory experiments indicate that certain rock types, whose resistivity is controlled by the volume and geometry of microcracks, can undergo large resistivity variations in response to the typical strain accumulation and release that accompanies major ear...

  4. Linear response characteristics of time-dependent time fractional Fokker–Planck equation systems

    International Nuclear Information System (INIS)

    The time fractional Fokker–Planck equation approach is an important tool for modeling subdiffusion. When the external field is time modulated, two types of time-dependent time fractional Fokker–Planck equations have been proposed, both reduced to the same time-dependent time fractional Fokker–Planck equation when the external field is time uncorrelated. The first type is strictly deduced as the continuous limit of the continuous time random walk with time modulated Boltzmann jumping weight, while the second type is derived by ideally assuming that the jump probabilities can be evaluated at the start of the waiting time prior to jumping. For the first time we obtain the linear response characteristic for the first type of the time fractional Fokker–Planck equation systems, and for a comparison we revisit the corresponding result for the second type of the time fractional Fokker–Planck equation systems, and the similarity and difference between them is discussed with an application example. The investigation not only helps in understanding the competition between subdiffusion and time-dependent modulation, but also has significance in accessing the spectral properties of spontaneous fluctuation and the linear dynamic susceptibility of external perturbation in subdiffusive processes. (paper)

  5. Utility of phenylalanine hydroxylase genotype for tetrahydrobiopterin responsiveness classification in patients with phenylketonuria

    Science.gov (United States)

    Quirk, Meghan E.; Dobrowolski, Steven F.; Nelson, Benjamin E.; Coffee, Bradford; Singh, Rani H.

    2014-01-01

    Background A need exists to expand the characterization of tetrahydrobiopterin (BH4) responsiveness in patients with phenylketonuria (PKU), beyond simply evaluating change in blood phenylalanine concentrations. The clinical interpretation of BH4 responsiveness should be evaluated within the context of phenylalanine hydroxylase (PAH) genotype. Aim This investigation seeks to use a modified version of a previously developed PAH genotype severity tool, the assigned value (AV) sum, to assess the molecular basis of responsiveness in a clinical cohort and to explore the tool’s ability to differentiate BH4 responsive groups. Methods BH4 response was previously clinically classified in 58 patients with PKU, with three response groups emerging: definitive responders, provisional responders, and non-responders. Provisional responders represented a clinically ambiguous group, with an initial decrease in plasma phenylalanine concentrations, but limited ability to improve dietary phenylalanine tolerance. In this retrospective analysis, mutations in the PAH gene were identified in each patient. PAH genotype was characterized through the AV sum approach, in which each mutation is given an AV of 1, 2, 4, or 8; the sum of both mutations’ AV corresponds to genotype severity, with a lower number representing a more severe phenotype. An AV sum cutoff of 2 (indicative of the most severe genotypes) was used to dichotomize patients and predict BH4 responsiveness. Provisional responders were classified with the definitive responders then the non-responders to see with which group they best aligned. Results In 17/19 definitive responders, at least one mutation was mild or moderate in severity (AV sum>2). In contrast, 7/9 provisional responders carried two severe or null mutations (AV sum=2), suggesting little molecular basis for responsiveness. Non-responders represent a heterogeneous group with 15/25 patients carrying two severe mutations (AV sum=2), 5/25 patients carrying one

  6. Stream classification of the Apalachicola-Chattahoochee-Flint River System to support modeling of aquatic habitat response to climate change

    Science.gov (United States)

    Elliott, Caroline M.; Jacobson, Robert B.; Freeman, Mary C.

    2014-01-01

    A stream classification and associated datasets were developed for the Apalachicola-Chattahoochee-Flint River Basin to support biological modeling of species response to climate change in the southeastern United States. The U.S. Geological Survey and the Department of the Interior’s National Climate Change and Wildlife Science Center established the Southeast Regional Assessment Project (SERAP) which used downscaled general circulation models to develop landscape-scale assessments of climate change and subsequent effects on land cover, ecosystems, and priority species in the southeastern United States. The SERAP aquatic and hydrologic dynamics modeling efforts involve multiscale watershed hydrology, stream-temperature, and fish-occupancy models, which all are based on the same stream network. Models were developed for the Apalachicola-Chattahoochee-Flint River Basin and subbasins in Alabama, Florida, and Georgia, and for the Upper Roanoke River Basin in Virginia. The stream network was used as the spatial scheme through which information was shared across the various models within SERAP. Because these models operate at different scales, coordinated pair versions of the network were delineated, characterized, and parameterized for coarse- and fine-scale hydrologic and biologic modeling. The stream network used for the SERAP aquatic models was extracted from a 30-meter (m) scale digital elevation model (DEM) using standard topographic analysis of flow accumulation. At the finer scale, reaches were delineated to represent lengths of stream channel with fairly homogenous physical characteristics (mean reach length = 350 m). Every reach in the network is designated with geomorphic attributes including upstream drainage basin area, channel gradient, channel width, valley width, Strahler and Shreve stream order, stream power, and measures of stream confinement. The reach network was aggregated from tributary junction to tributary junction to define segments for the

  7. Unsupervised classification of saturated areas using a time series of remotely sensed images

    Directory of Open Access Journals (Sweden)

    D. A. DeAlwis

    2007-06-01

    Full Text Available The spatial distribution of saturated areas is an important consideration in numerous applications, such as water resource planning or sighting of management practices. However, in humid well vegetated climates where runoff is produced by saturation excess processes on hydrologically active areas (HAA the delineation of these areas can be difficult and time consuming. Much of the non-point source pollution in these watersheds originates from these HAAs. Thus, a technique that can simply and reliably predict these areas would be a powerful tool for scientists and watershed managers tasked with implementing practices to improve water quality. Remotely sensed data is a source of spatial information and could be used to identify HAAs, should a proper technique be developed. The objective of this study is to develop a methodology to determine the spatial variability of saturated areas using a temporal sequence of remotely sensed images. The Normalized Difference Water Index (NDWI was derived from medium resolution LANDSAT 7 ETM+ imagery collected over seven months in the Town Brook watershed in the Catskill Mountains of New York State and used to characterize the areas that were susceptible to saturation. We found that within a single landcover type, saturated areas were characterized by the soil surface water content when the vegetation was dormant and leaf water content of vegetation during the growing season. The resulting HAA map agreed well with both observed and spatially distributed computer simulated saturated areas. This methodology appears promising for delineating saturated areas in the landscape.

  8. Real-Time Classification of Seagrass Meadows on Flat Bottom with Bathymetric Data Measured by a Narrow Multibeam Sonar System

    Directory of Open Access Journals (Sweden)

    Masahiro Hamana

    2016-01-01

    Full Text Available Seagrass meadows, one of the most important habitats for many marine species, provide essential ecological services. Thus, society must conserve seagrass beds as part of their sustainable development efforts. Conserving these ecosystems requires information on seagrass distribution and relative abundance, and an efficient, accurate monitoring system. Although narrow multibeam sonar systems (NMBSs are highly effective in resolving seagrass beds, post-processing methods are required to extract key data. The purpose of this study was to develop a simple method capable of detecting seagrass meadows and estimating their relative abundance in real time using an NMBS. Because most seagrass meadows grow on sandy seafloors, we proposed a way of discriminating seagrass meadows from the sand bed. We classify meadows into three categories of relative seagrass abundance using the 95% confidence level of beam depths and the depth range of the beam depth. These are respectively two times the standard deviation of beam depths, and the difference between the shallowest and the deepest depths in a 0.5 × 0.5 m grid cell sampled with several narrow beams. We examined Zostera caulescens Miki, but this simple NMBS method of seagrass classification can potentially be used to map seagrass meadows with longer shoots of other species, such as Posidonia, as both have gas filled cavities.

  9. Classification mapping and species identification of salt marshes based on a short-time interval NDVI time-series from HJ-1 optical imagery

    Science.gov (United States)

    Sun, Chao; Liu, Yongxue; Zhao, Saishuai; Zhou, Minxi; Yang, Yuhao; Li, Feixue

    2016-03-01

    Salt marshes are seen as the most dynamic and valuable ecosystems in coastal zones, and in these areas, it is crucial to obtain accurate remote sensing information on the spatial distributions of species over time. However, discriminating various types of salt marsh is rather difficult because of their strong spectral similarities. Previous salt marsh mapping studies have focused mainly on high spatial and spectral (i.e., hyperspectral) resolution images combined with auxiliary information; however, the results are often limited to small regions. With a high temporal and moderate spatial resolution, the Chinese HuanJing-1 (HJ-1) satellite optical imagery can be used not only to monitor phenological changes of salt marsh vegetation over short-time intervals, but also to obtain coverage of large areas. Here, we apply HJ-1 satellite imagery to the middle coast of Jiangsu in east China to monitor changes in saltmarsh vegetation cover. First, we constructed a monthly NDVI time-series to classify various types of salt marsh and then we tested the possibility of using compressed time-series continuously, to broaden the applicability of this particular approach. Our principal findings are as follows: (1) the overall accuracy of salt marsh mapping based on the monthly NDVI time-series was 90.3%, which was ∼16.0% higher than the single-phase classification strategy; (2) a compressed time-series, including NDVI from six key months (April, June-September, and November), demonstrated very little reduction (2.3%) in overall accuracy but led to obvious improvements in unstable regions; and (3) a simple rule for Spartina alterniflora identification was established using a scene solely from November, which may provide an effective way for regularly monitoring its distribution.

  10. Influence of the Helicopter Time Domain Electromagnetic System Off-Time Response by the Transmitter Assembly

    Science.gov (United States)

    Vetrov, A.; Mejzr, I.

    2010-12-01

    While developing a new Helicopter Time Domain Electromagnetic system (P-THEM), Pico Envirotec Inc (PEI) has studied the effect of the transmitter assembly on the acquired data. The P-THEM system consists of a loop-transmitter assembly, powered by a motor generator, 3-axis coil receiver attached at the midpoint of a tow cable and an additional Z-axis (dB/dt) receiver installed on the rear section of the transmitter loop. The system is towed by a helicopter on a 230 foot long tow cable. The transmitter loop is designed to produce a peak magnetic moment of approximately 250,000 NIA with a base frequency of 30 Hz (adjustable to 25Hz) and a quarter length duty cycle (4 ms on-time). The secondary field acquired with a dB/dt receiver coil consists of a ground response and a system response: SF=Rg+Rsys, where SF - the secondary field, Rg - ground response, Rsys - system response. The system itself, especially the transmitter assembly, being a conductor in an induced magnetic field, creates a magnetic anomaly. The influence of the transmitter assembly anomaly on the received signal depends on the position of the receiver coil against the transmitter, the intensity of on-time pulse and transmitter electro-magnetic properties. At the same time, the ground response acquired with a receiver coil depends on the length and the moment of transmitter pulse, as well as the position and distance of the receiver coil from the ground. This can be for vertical field (Z) receiver coil described as RXz(t)=e(t)pz(t)Rgz(t)+d(t)k(t)j(t)TXz(t), where RXz(t) - receiver response, e(t) - elevation of the receiver over the ground, pz(t) - horizontal projection of the receiver coil, Rgz(t) - vertical component of ground response, d(t) - distance (elevation) between the receiver coil and the transmitter loop, k(t) - the position of the receiver in the transmitter field, j(t) - the transmitter assembly electromagnetic properties, TXz(t) -transmitter field (Primary field on-time, and transmitter

  11. Comparison of Hybrid Classifiers for Crop Classification Using Normalized Difference Vegetation Index Time Series: A Case Study for Major Crops in North Xinjiang, China.

    Directory of Open Access Journals (Sweden)

    Pengyu Hao

    Full Text Available A range of single classifiers have been proposed to classify crop types using time series vegetation indices, and hybrid classifiers are used to improve discriminatory power. Traditional fusion rules use the product of multi-single classifiers, but that strategy cannot integrate the classification output of machine learning classifiers. In this research, the performance of two hybrid strategies, multiple voting (M-voting and probabilistic fusion (P-fusion, for crop classification using NDVI time series were tested with different training sample sizes at both pixel and object levels, and two representative counties in north Xinjiang were selected as study area. The single classifiers employed in this research included Random Forest (RF, Support Vector Machine (SVM, and See 5 (C 5.0. The results indicated that classification performance improved (increased the mean overall accuracy by 5%~10%, and reduced standard deviation of overall accuracy by around 1% substantially with the training sample number, and when the training sample size was small (50 or 100 training samples, hybrid classifiers substantially outperformed single classifiers with higher mean overall accuracy (1%~2%. However, when abundant training samples (4,000 were employed, single classifiers could achieve good classification accuracy, and all classifiers obtained similar performances. Additionally, although object-based classification did not improve accuracy, it resulted in greater visual appeal, especially in study areas with a heterogeneous cropping pattern.

  12. Real-time Pricing Demand Response in Operations

    Energy Technology Data Exchange (ETDEWEB)

    Widergren, Steven E.; Marinovici, Maria C.; Berliner, Teri; Graves, Alan

    2012-07-26

    Abstract—Dynamic pricing schemes have been implemented in commercial and industrial application settings, and recently they are getting attention for application to residential customers. Time-of-use and critical-peak-pricing rates are in place in various regions and are being piloted in many more. These programs are proving themselves useful for balancing energy during peak periods; however, real-time (5 minute) pricing signals combined with automation in end-use systems have the potential to deliver even more benefits to operators and consumers. Besides system peak shaving, a real-time pricing system can contribute demand response based on the locational marginal price of electricity, reduce load in response to a generator outage, and respond to local distribution system capacity limiting situations. The US Department of Energy (DOE) is teaming with a mid-west electricity service provider to run a distribution feeder-based retail electricity market that negotiates with residential automation equipment and clears every 5 minutes, thus providing a signal for lowering or raising electric consumption based on operational objectives of economic efficiency and reliability. This paper outlines the capability of the real-time pricing system and the operational scenarios being tested as the system is rolled-out starting in the first half of 2012.

  13. Classification Trees for Quality Control Processes in Automated Constructed Response Scoring.

    Science.gov (United States)

    Williamson, David M.; Hone, Anne S.; Miller, Susan; Bejar, Isaac I.

    As the automated scoring of constructed responses reaches operational status, the issue of monitoring the scoring process becomes a primary concern, particularly when the goal is to have automated scoring operate completely unassisted by humans. Using a vignette from the Architectural Registration Examination and data for 326 cases with both human…

  14. A specialist-generalist classification of the arable flora and its response to changes in agricultural practices

    Directory of Open Access Journals (Sweden)

    Fried Guillaume

    2010-09-01

    Full Text Available Abstract Background Theory in ecology points out the potential link between the degree of specialisation of organisms and their responses to disturbances and suggests that this could be a key element for understanding the assembly of communities. We evaluated this question for the arable weed flora as this group has scarcely been the focus of ecological studies so far and because weeds are restricted to habitats characterised by very high degrees of disturbance. As such, weeds offer a case study to ask how specialization relates to abundance and distribution of species in relation to the varying disturbance regimes occurring in arable crops. Results We used data derived from an extensive national monitoring network of approximately 700 arable fields scattered across France to quantify the degree of specialisation of 152 weed species using six different ecological methods. We then explored the impact of the level of disturbance occurring in arable fields by comparing the degree of specialisation of weed communities in contrasting field situations. The classification of species as specialist or generalist was consistent between different ecological indices. When applied on a large-scale data set across France, this classification highlighted that monoculture harbour significantly more specialists than crop rotations, suggesting that crop rotation increases abundance of generalist species rather than sets of species that are each specialised to the individual crop types grown in the rotation. Applied to a diachronic dataset, the classification also shows that the proportion of specialist weed species has significantly decreased in cultivated fields over the last 30 years which suggests a biotic homogenization of agricultural landscapes. Conclusions This study shows that the concept of generalist/specialist species is particularly relevant to understand the effect of anthropogenic disturbances on the evolution of plant community composition and that

  15. Modeling in Real Time During the Ebola Response.

    Science.gov (United States)

    Meltzer, Martin I; Santibanez, Scott; Fischer, Leah S; Merlin, Toby L; Adhikari, Bishwa B; Atkins, Charisma Y; Campbell, Caresse; Fung, Isaac Chun-Hai; Gambhir, Manoj; Gift, Thomas; Greening, Bradford; Gu, Weidong; Jacobson, Evin U; Kahn, Emily B; Carias, Cristina; Nerlander, Lina; Rainisch, Gabriel; Shankar, Manjunath; Wong, Karen; Washington, Michael L

    2016-01-01

    To aid decision-making during CDC's response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa, CDC activated a Modeling Task Force to generate estimates on various topics related to the response in West Africa and the risk for importation of cases into the United States. Analysis of eight Ebola response modeling projects conducted during August 2014-July 2015 provided insight into the types of questions addressed by modeling, the impact of the estimates generated, and the difficulties encountered during the modeling. This time frame was selected to cover the three phases of the West African epidemic curve. Questions posed to the Modeling Task Force changed as the epidemic progressed. Initially, the task force was asked to estimate the number of cases that might occur if no interventions were implemented compared with cases that might occur if interventions were implemented; however, at the peak of the epidemic, the focus shifted to estimating resource needs for Ebola treatment units. Then, as the epidemic decelerated, requests for modeling changed to generating estimates of the potential number of sexually transmitted Ebola cases. Modeling to provide information for decision-making during the CDC Ebola response involved limited data, a short turnaround time, and difficulty communicating the modeling process, including assumptions and interpretation of results. Despite these challenges, modeling yielded estimates and projections that public health officials used to make key decisions regarding response strategy and resources required. The impact of modeling during the Ebola response demonstrates the usefulness of modeling in future responses, particularly in the early stages and when data are scarce. Future modeling can be enhanced by planning ahead for data needs and data sharing, and by open communication among modelers, scientists, and others to ensure that modeling and its limitations are more clearly understood. The activities summarized in

  16. Time orientation, planning horizons and responsibility into the future

    International Nuclear Information System (INIS)

    Subjects of four categories (social science students, engineering students, retired people and nuclear waste experts) were asked about past events, planning, risks and future time with emphasis on energy related issues and in particular questions concerning spent nuclear waste. Among, the results reported it was found that events in the past were located more or less correctly and that events further back systematically too close to the present. Today's responsibility into the future was judged to cover 3 to 6 generations ahead and an adequate planning horizon for a local community to be on the average 11 to 14 years. Adequate planning horizons for the handling of spent nuclear fuel were judged to be from 100 to 500 years. The responsibility for effects of today's decisions was judged to be from about 100 to 300 years into the future for environmental pollution and from about 50 to 600 years for nuclear waste. However, non-negliqable proportions of the subjects choose a more moral standpoint and gave answers indicating that responsibility had to be unlimited. Some sex differences were found and an interaction with age offered as a hypothesis to be investigated in the future. Interrelations between clusters of questions revealed some links from past time and planning to judgements of environmental and nuclear power related risks. (orig.)

  17. Feature Selection of Time Series MODIS Data for Early Crop Classification Using Random Forest: A Case Study in Kansas, USA

    Directory of Open Access Journals (Sweden)

    Pengyu Hao

    2015-04-01

    Full Text Available Currently, accurate information on crop area coverage is vital for food security and industry, and there is strong demand for timely crop mapping. In this study, we used MODIS time series data to investigate the effect of the time series length on crop mapping. Eight time series with different lengths (ranging from one month to eight months were tested. For each time series, we first used the Random Forest (RF algorithm to calculate the importance score for all features (including multi-spectral data, Normalized Difference Vegetation Index (NDVI, Normalized Difference Water Index (NDWI, and phenological metrics. Subsequently, an extension of the Jeffries–Matusita (JM distance was used to measure class separability for each time series. Finally, the RF algorithm was used to classify crop types, and the classification accuracy and certainty were used to analyze the influence of the time series length and the number of features on classification performance; the features were added one by one based on their importance scores. Results indicated that when the time series was longer than five months, the top ten features remained stable. These features were mainly in July and August. In addition, the NDVI features contributed the majority of the most significant features for crop mapping. The NDWI and data from multi-spectral bands also contributed to improving crop mapping. On the other hand, separability, classification accuracy, and certainty increased with the number of features used and the time series length, although these values quickly reached saturation. Five months was the optimal time series length, as longer time series provided no further improvement in the classification performance. This result shows that relatively short time series have the potential to identify crops accurately, which allows for early crop mapping over large areas.

  18. Study of the time response of a LuAG(Pr) crystal for fast timing applications

    Science.gov (United States)

    Fraile, L. M.; Mach, H.; Picado, E.; Vedia, V.; Udías, J. M.

    2013-06-01

    The recently developed praseodymium-doped lutetium aluminum garnet, LuAG(Pr), holds a strong potential for fast timing applications. In this study we report on the time response of LuAG(Pr) at 22Na and 60Co photon energies. The measurements were performed using a small crystal cube of 1 cm3 coupled to a Hamamatsu R5320 photomultiplier tube. The full width at half maximum (FWHM) time resolution is found to be 147±2 ps at 60Co energies, and 238±2 ps at 22Na.

  19. Study of the time response of a LuAG(Pr) crystal for fast timing applications

    International Nuclear Information System (INIS)

    The recently developed praseodymium-doped lutetium aluminum garnet, LuAG(Pr), holds a strong potential for fast timing applications. In this study we report on the time response of LuAG(Pr) at 22Na and 60Co photon energies. The measurements were performed using a small crystal cube of 1 cm3 coupled to a Hamamatsu R5320 photomultiplier tube. The full width at half maximum (FWHM) time resolution is found to be 147±2 ps at 60Co energies, and 238±2 ps at 22Na

  20. A Study of Time Response for Safety-Related Operator Actions in Non-LOCA Safety Analysis

    International Nuclear Information System (INIS)

    The classification of initiating events for safety analysis report (SAR) chapter 15 is categorized into moderate frequency events (MF), infrequent events (IF), and limiting faults (LF) depending on the frequency of its occurrence. For the non-LOCA safety analysis with the purpose to get construction or operation license, however, it is assumed that the operator response action to mitigate the events starts at 30 minutes after the initiation of the transient regardless of the event categorization. Such an assumption of corresponding operator response time may have over conservatism with the MF and IF events and results in a decrease in the safety margin compared to its acceptance criteria. In this paper, the plant conditions (PC) are categorized with the definitions in SAR 15 and ANS 51.1. Then, the consequence of response for safety-related operator action time is determined based on the PC in ANSI 58.8. The operator response time for safety analysis regarding PC are reviewed and suggested. The clarifying alarm response procedure would be required for the guideline to reduce the operator response time when the alarms indicate the occurrence of the transient

  1. Potentials of RapidEye time series for improved classification of crop rotations in heterogeneous agricultural landscapes: experiences from irrigation systems in Central Asia

    Science.gov (United States)

    Conrad, Christopher; Machwitz, Miriam; Schorcht, Gunther; Löw, Fabian; Fritsch, Sebastian; Dech, Stefan

    2011-11-01

    In Central Asia, more than eight Million ha of agricultural land are under irrigation. But severe degradation problems and unreliable water distribution have caused declining yields during the past decades. Reliable and area-wide information about crops can be seen as important step to elaborate options for sustainable land and water management. Experiences from RapidEye classifications of crop in Central Asia are exemplarily shown during a classification of eight crop classes including three rotations with winter wheat, cotton, rice, and fallow land in the Khorezm region of Uzbekistan covering 230,000 ha of irrigated land. A random forest generated by using 1215 field samples was applied to multitemporal RapidEye data acquired during the vegetation period 2010. But RapidEye coverage varied and did not allow for generating temporally consistent mosaics covering the entire region. To classify all 55,188 agricultural parcels in the region three classification zones were classified separately. The zoning allowed for including at least three observation periods into classification. Overall accuracy exceeded 85 % for all classification zones. Highest accuracies of 87.4 % were achieved by including five spatiotemporal composites of RapidEye. Class-wise accuracy assessments showed the usefulness of selecting time steps which represent relevant phenological phases of the vegetation period. The presented approach can support regional crop inventory. Accurate classification results in early stages of the cropping season permit recalculation of crop water demands and reallocation of irrigation water. The high temporal and spatial resolution of RapidEye can be concluded highly beneficial for agricultural land use classifications in entire Central Asia.

  2. Classification of frequency response areas in the inferior colliculus reveals continua not discrete classes

    OpenAIRE

    Palmer, Alan R; Shackleton, Trevor M.; Sumner, Christian J.; Zobay, Oliver; Rees, Adrian

    2013-01-01

    A differential response to sound frequency is a fundamental property of auditory neurons. Frequency analysis in the cochlea gives rise to V-shaped tuning functions in auditory nerve fibres, but by the level of the inferior colliculus (IC), the midbrain nucleus of the auditory pathway, neuronal receptive fields display diverse shapes that reflect the interplay of excitation and inhibition. The origin and nature of these frequency receptive field types is still open to question. One proposed hy...

  3. You Can’t Think and Hit at the Same Time: Neural Correlates of Baseball Pitch Classification

    Directory of Open Access Journals (Sweden)

    Jason eSherwin

    2012-12-01

    Full Text Available Hitting a baseball is often described as the most difficult thing to do in sports. A key aptitude of a good hitter is the ability to determine which pitch is coming. This rapid decision requires the batter to make a judgment in a fraction of a second based largely on the trajectory and spin of the ball. When does this decision occur relative to the ball’s trajectory and is it possible to identify neural correlates that represent how the decision evolves over a split second? Using single-trial analysis of electroencephalography (EEG we address this question within the context of subjects discriminating three types of pitches (fastball, curveball, slider based on pitch trajectories. We find clear neural signatures of pitch classification and, using signal detection theory, we identify the times of discrimination on a trial-to-trial basis. Based on these neural signatures we estimate neural discrimination distributions as a function of the distance the ball is from the plate. We find all three pitches yield unique distributions, namely the timing of the discriminating neural signatures relative to the position of the ball in its trajectory. For instance, fastballs are discriminated at the earliest points in their trajectory, relative to the two other pitches, which is consistent with the need for some constant time to generate and execute the motor plan for the swing (or inhibition of the swing. We also find incorrect discrimination of a pitch (errors yields neural sources in Brodmann Area 10 (BA 10, which has been implicated in prospective memory, recall and task difficulty. In summary, we show that single-trial analysis of EEG yields informative distributions of the relative point in a baseball’s trajectory when the batter makes a decision on which pitch is coming.

  4. Time-dependent response of dissipative electron systems

    International Nuclear Information System (INIS)

    We present a systematic study of the influence of energy and phase relaxation on dynamic polarizability simulations in the linear response regime. The nonperturbative approach is based on explicit electron dynamics using short laser pulses of low intensities. To include environmental effects on the property calculation, we use the time-dependent configuration-interaction method in its reduced density matrix formulation. Both energy dissipation and nonlocal pure dephasing are included. The explicit treatment of time-resolved electron dynamics gives access to the phase shift between the electric field and the induced dipole moment, which can be used to define a useful uncertainty measure for the dynamic polarizability. The nonperturbative treatment is compared to perturbation theory expressions, as applied to a simple model system, the rigid H2 molecule. It is shown that both approaches are equivalent for low field intensities, but the time-dependent treatment provides complementary information on the phase of the induced dipole moment, which allows for the definition of an uncertainty associated with the computation of the dynamic polarizability in the linear response regime.

  5. Gemstones and geosciences in space and time. Digital maps to the "Chessboard classification scheme of mineral deposits"

    Science.gov (United States)

    Dill, Harald G.; Weber, Berthold

    2013-12-01

    The gemstones, covering the spectrum from jeweler's to showcase quality, have been presented in a tripartite subdivision, by country, geology and geomorphology realized in 99 digital maps with more than 2600 mineralized sites. The various maps were designed based on the "Chessboard classification scheme of mineral deposits" proposed by Dill (2010a, 2010b) to reveal the interrelations between gemstone deposits and mineral deposits of other commodities and direct our thoughts to potential new target areas for exploration. A number of 33 categories were used for these digital maps: chromium, nickel, titanium, iron, manganese, copper, tin-tungsten, beryllium, lithium, zinc, calcium, boron, fluorine, strontium, phosphorus, zirconium, silica, feldspar, feldspathoids, zeolite, amphibole (tiger's eye), olivine, pyroxenoid, garnet, epidote, sillimanite-andalusite, corundum-spinel - diaspore, diamond, vermiculite-pagodite, prehnite, sepiolite, jet, and amber. Besides the political base map (gems by country) the mineral deposit is drawn on a geological map, illustrating the main lithologies, stratigraphic units and tectonic structure to unravel the evolution of primary gemstone deposits in time and space. The geomorphological map is to show the control of climate and subaerial and submarine hydrography on the deposition of secondary gemstone deposits. The digital maps are designed so as to be plotted as a paper version of different scale and to upgrade them for an interactive use and link them to gemological databases.

  6. Statistical classification of log response as an indicator of facies variation during changes in sea level

    DEFF Research Database (Denmark)

    Inwood, Jennifer; Lofi, Johanna; Davies, Sarah;

    2013-01-01

    composition, and stratal geometries in response to sea-level changes. The novel approach of combining statistical analysis with detailed lithostratigraphic and seismic reflection data sets will be of interest to any scientists working with downhole logs, especially spectral gamma-ray data, and also provides a...... reference for the strengths and weaknesses of multi component analysis applied to continental margin lithofacies. The method presented here is appropriate for evaluating successions elsewhere and also has value for hydrocarbon exploration where sequence stratigraphy is a fundamental tool....

  7. Nominal classification

    OpenAIRE

    Senft, G.

    2007-01-01

    This handbook chapter summarizes some of the problems of nominal classification in language, presents and illustrates the various systems or techniques of nominal classification, and points out why nominal classification is one of the most interesting topics in Cognitive Linguistics.

  8. The effect of alcohol hangover on choice response time.

    Science.gov (United States)

    Grange, James A; Stephens, Richard; Jones, Kate; Owen, Lauren

    2016-07-01

    The effect of alcohol hangover on cognitive processing has received little attention. We explored the effect of alcohol hangover on choice response time (RT), a dominant dependent variable (DV) in cognitive research. Prior research of the effect of hangover on RT has produced mixed findings; all studies reviewed relied exclusively on estimates of central tendency (e.g. mean RT), which has limited information value. Here we present novel analytical methods by going beyond mean RT analysis. Specifically, we examined performance in hangover conditions (n=31) across the whole RT distribution by fitting ex-Gaussian models to participant data, providing a formal description of the RT distribution. This analysis showed detriments to performance under hangover conditions at the slower end of the RT distribution and increased RT variance under hangover conditions. We also fitted an explicit mathematical process model of choice RT - the diffusion model - which estimates parameters reflecting psychologically-meaningful processes underlying choice RT. This analysis showed that hangover reduced information processing efficiency during response selection, and increased response caution; changes in these parameters reflect hangover affecting core decisional-components of RT performance. The implications of the data as well as the methods used for hangover research are discussed. PMID:27166364

  9. The Potential of Time Series Merged from Landsat-5 TM and HJ-1 CCD for Crop Classification: A Case Study for Bole and Manas Counties in Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Pengyu Hao

    2014-08-01

    Full Text Available Time series data capture crop growth dynamics and are some of the most effective data sources for crop mapping. However, a drawback of precise crop classification at medium resolution (30 m using multi-temporal data is that some images at crucial time periods are absent from a single sensor. In this research, a medium-resolution, 15-day time series was obtained by merging Landsat-5 TM and HJ-1 CCD data (with similar radiometric performances in multi-spectral bands. Subsequently, optimal temporal windows for accurate crop mapping were evaluated using an extension of the Jeffries–Matusita (JM distance from the merged time series. A support vector machine (SVM was then used to compare the classification accuracy of the optimal temporal windows and the entire time series. In addition, different training sample sizes (10% to 90% of the entire training sample in 10% increments; five repetitions for each sample size were used to investigate the stability of optimal temporal windows. The results showed that time series in optimal temporal windows can achieve high classification accuracies. The optimal temporal windows were robust when the training sample size was sufficiently large. However, they were not stable when the sample size was too small (i.e., less than 300 and may shift in different agro-ecosystems, because of different classes. In addition, merged time series had higher temporal resolution and were more likely to comprise the optimal temporal periods than time series from single-sensor data. Therefore, the use of merged time series increased the possibility of precise crop classification.

  10. SO/sub 2/ dose-response sensitivity classification data for crops and natural vegetation species

    Energy Technology Data Exchange (ETDEWEB)

    Irving, P.M.; Ballou, S.W.

    1980-09-01

    Over the past several years studies have been made on the interaction of sulfur dioxide (SO/sub 2/) and vegetation by performing field research and by developing analytical procedures for applying field observation data to energy impact assessments. As a result of this work, numerous reports have been prepared on crop-pollutant interactions, such as dose-response data; on the applications of such data to screening approaches for identifying crops at risk; and on models that predict crop yield reductions from point source emissions of SO/sub 2/. Data that were used for these studies, such as the crop-at-risk screening procedure, are presented in this report. Maps are also presented that show the national distribution of SO/sub 2/-sensitive crops and natural vegetation.

  11. The Fermi Large Area Telescope On Orbit: Event Classification, Instrument Response Functions, and Calibration

    CERN Document Server

    ,

    2012-01-01

    The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy \\gamma-ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the Instrument Response Functions (IRFs), the description of the instrument performance provided for data analysis. In this paper we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team h...

  12. The Fermi Large Area Telescope on Orbit: Event Classification, Instrument Response Functions, and Calibration

    Science.gov (United States)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Celik, Q.; Cobet, R.; Davis, D. S.; Ferrara, E. C.; Gehrels, N.; Guiriec, S.; McConville, W.; McEnery, J. E.; Nemmen, R.; Perkins, J. S.; Thompson, D. J.

    2012-01-01

    The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy -ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the Instrument Response Functions (IRFs), the description of the instrument performance provided for data analysis. In this paper we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.

  13. THE FERMI LARGE AREA TELESCOPE ON ORBIT: EVENT CLASSIFICATION, INSTRUMENT RESPONSE FUNCTIONS, AND CALIBRATION

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M.; Allafort, A.; Bechtol, K.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Borgland, A. W.; Bottacini, E. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Albert, A. [Department of Physics, Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Atwood, W. B.; Bouvier, A. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Axelsson, M. [Department of Astronomy, Stockholm University, SE-106 91 Stockholm (Sweden); Baldini, L. [Universita di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bissaldi, E. [Institut fuer Astro- und Teilchenphysik and Institut fuer Theoretische Physik, Leopold-Franzens-Universitaet Innsbruck, A-6020 Innsbruck (Austria); Bonamente, E., E-mail: echarles@slac.stanford.edu, E-mail: luca.baldini@pi.infn.it, E-mail: rando@pd.infn.it [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); and others

    2012-11-15

    The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy {gamma}-ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission, the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the instrument response functions (IRFs), the description of the instrument performance provided for data analysis. In this paper, we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.

  14. THE FERMI LARGE AREA TELESCOPE ON ORBIT: EVENT CLASSIFICATION, INSTRUMENT RESPONSE FUNCTIONS, AND CALIBRATION

    International Nuclear Information System (INIS)

    The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy γ-ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission, the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the instrument response functions (IRFs), the description of the instrument performance provided for data analysis. In this paper, we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.

  15. Driving time modulates accommodative response and intraocular pressure.

    Science.gov (United States)

    Vera, Jesús; Diaz-Piedra, Carolina; Jiménez, Raimundo; Morales, José M; Catena, Andrés; Cardenas, David; Di Stasi, Leandro L

    2016-10-01

    Driving is a task mainly reliant on the visual system. Most of the time, while driving, our eyes are constantly focusing and refocusing between the road and the dashboard or near and far traffic. Thus, prolonged driving time should produce visual fatigue. Here, for the first time, we investigated the effects of driving time, a common inducer of driver fatigue, on two ocular parameters: the accommodative response (AR) and the intraocular pressure (IOP). A pre/post-test design has been used to assess the impact of driving time on both indices. Twelve participants (out of 17 recruited) completed the study (5 women, 24.42±2.84years old). The participants were healthy and active drivers with no visual impairment or pathology. They drove for 2h in a virtual driving environment. We assessed AR and IOP before and after the driving session, and also collected subjective measures of arousal and fatigue. We found that IOP and AR decreased (i.e., the accommodative lag increased) after the driving session (p=0.03 and p<0.001, respectively). Moreover, the nearest distances tested (20cm, 25cm, and 33cm) induced the highest decreases in AR (corrected p-values<0.05). Consistent with these findings, the subjective levels of arousal decreased and levels of fatigue increased after the driving session (all p-values<0.001). These results represent an innovative step towards an objective, valid, and reliable assessment of fatigue-impaired driving based on visual fatigue signs. PMID:27235337

  16. Land Cover and Crop Type Classification along the Season Based on Biophysical Variables Retrieved from Multi-Sensor High-Resolution Time Series

    Directory of Open Access Journals (Sweden)

    François Waldner

    2015-08-01

    Full Text Available With the ever-increasing number of satellites and the availability of data free of charge, the integration of multi-sensor images in coherent time series offers new opportunities for land cover and crop type classification. This article investigates the potential of structural biophysical variables as common parameters to consistently combine multi-sensor time series and to exploit them for land/crop cover classification. Artificial neural networks were trained based on a radiative transfer model in order to retrieve high resolution LAI, FAPAR and FCOVER from Landsat-8 and SPOT-4. The correlation coefficients between field measurements and the retrieved biophysical variables were 0.83, 0.85 and 0.79 for LAI, FAPAR and FCOVER, respectively. The retrieved biophysical variables’ time series displayed consistent average temporal trajectories, even though the class variability and signal-to-noise ratio increased compared to NDVI. Six random forest classifiers were trained and applied along the season with different inputs: spectral bands, NDVI, as well as FAPAR, LAI and FCOVER, separately and jointly. Classifications with structural biophysical variables reached end-of-season overall accuracies ranging from 73%–76% when used alone and 77% when used jointly. This corresponds to 90% and 95% of the accuracy level achieved with the spectral bands and NDVI. FCOVER appears to be the most promising biophysical variable for classification. When assuming that the cropland extent is known, crop type classification reaches 89% with spectral information, 87% with the NDVI and 81%–84% with biophysical variables.

  17. The simulation of temperature dependence of responsivity and response time for 6H-SiC UV photodetector

    Institute of Scientific and Technical Information of China (English)

    Zhang Yi-Men; Zhou Yong-Hua; Zhang Yu-Ming

    2007-01-01

    In this paper the temperature dependence of responsivity and response time for 6H-SiC ultraviolet (UV) photodetector is simulated based on numerical model in the range from 300 K to 900 K. The simulation results show that the responsivity and the response time of device are less sensitive to temperature and this kind of UV photodetector has excellent temperature stability. Also the effects of device structure and bias voltage on the responsivity and the response time are presented. The thicker the drift region is, the higher the responsivity and the longer the response time are. So the thickness of drift region has to be carefully designed to make trade-off between responsivity and response time.

  18. Musings on galaxy classification

    International Nuclear Information System (INIS)

    Classification schemes and their utility are discussed with a number of examples, particularly for cD galaxies. Data suggest that primordial turbulence rather than tidal torques is responsible for most of the presently observed angular momentum of galaxies. Finally, some of the limitations on present-day schemes for galaxy classification are pointed out. 54 references, 4 figures, 3 tables

  19. Classification of magnons in rotated ferromagnetic Heisenberg model and their competing responses in transverse fields

    Science.gov (United States)

    Sun, Fadi; Ye, Jinwu; Liu, Wu-Ming

    2016-07-01

    In this paper, we study the rotated ferromagnetic Heisenberg model (RFHM) in two different transverse fields, hx and hz, which can be intuitively visualized as studying spin-orbit coupling (SOC) effects in two-dimensional (2D) Ising or anisotropic X Y model in a transverse field. At a special SOC class, it was found in our previous work [Phys. Rev. A 92, 043609 (2015), 10.1103/PhysRevA.92.043609] that the RFHM at a zero field owns an exact spin-orbit coupled ground state called the Y -x state. It supports not only the commensurate magnons (called C -C0 and C -Cπ ), but also the incommensurate magnons (called C-IC). These magnons are nonrelativistic, not embedded in the exact ground state, so need to be thermally excited or generated by various external probes. Their dramatic response under a longitudinal hy field was recently worked out by Sun et al. [arXiv:1502.05338]. Here we find they respond very differently under the two transverse fields. Any hx (hz) introduces quantum fluctuations to the ground state and changes the collinear Y -x state to a canted coplanar Y X -x (Y Z -x ) state. The C -C0,C -Cπ , and C-IC magnons become relativistic and sneak into the quantum ground state. We determine the competing boundaries among the C -C0,C -Cπ , and C-IC magnons, especially the detailed dispersions of the C-IC magnons inside the canted phases, which can be mapped out by the transverse spin structure factors. As hx (hz) increases further, the C -C0 magnons always win the competition and emerge as the seeds to drive a transition from the Y X -x (or Y Z -x ) to the ferromagnetic along the X (orZ ) direction called the X -FM (or Z -FM) phase. We show that the transition is in the 3D Ising universality class and it becomes the 3D X Y transition at the two Abelian points. We evaluate these magnons' contributions to magnetization and specific heat at low temperatures which can be measured by various established experimental techniques. The nature of the finite

  20. Time and total dose response of non-volatile UVPROMs

    International Nuclear Information System (INIS)

    While survivability testing of floating gate non-volatile UVPROM memory devices has been documented in numerous journals, this paper reports on the total dose radiation response and intrinsic charge loss as a function of operating time in a system. Five groups of Intel and Signetics 27C256 devices were aged from one to five years through accelerated bake to simulate system use. Characterizations of the groups with five years of simulated use will be presented in detail in this paper. Device margin voltage was characterized before and after aging and after exposure to five total dose radiation levels (1K - 5K rads (Si)). A statistical model based upon the characterization data was developed to establish re-programming intervals for these devices when used in airborne electronic systems

  1. Shock response of iron on nanosecond time scales

    International Nuclear Information System (INIS)

    Experiments were performed using direct laser irradiation to induce shock waves in pure Fe foils tens of microns thick, using surface velocimetry to measure the response. Compared with experiments on much thicker samples, relatively strong elastic precursors were observed, though these could be caused by the strong texture of the foils rather than the shorter time scale. There was also evidence for the onset of the bcc to hcp phase transition, starting close to the static phase boundary. Radiation hydrodynamics and continuum mechanical simulations were performed to interpret the velocity data, comparing several equations of state with polymorphism and strength. The data were consistent with a phase change rate of the order of 109/s, driven by superpressurization of about 5 GPa. The rate may also depend on texture

  2. Non-invasive classification of severe sepsis and systemic inflammatory response syndrome using a nonlinear support vector machine: a preliminary study

    International Nuclear Information System (INIS)

    Sepsis has been defined as the systemic response to infection in critically ill patients, with severe sepsis and septic shock representing increasingly severe stages of the same disease. Based on the non-invasive cardiovascular spectrum analysis, this paper presents a pilot study on the potential use of the nonlinear support vector machine (SVM) in the classification of the sepsis continuum into severe sepsis and systemic inflammatory response syndrome (SIRS) groups. 28 consecutive eligible patients attending the emergency department with presumptive diagnoses of sepsis syndrome have participated in this study. Through principal component analysis (PCA), the first three principal components were used to construct the SVM feature space. The SVM classifier with a fourth-order polynomial kernel was found to have a better overall performance compared with the other SVM classifiers, showing the following classification results: sensitivity = 94.44%, specificity = 62.50%, positive predictive value = 85.00%, negative predictive value = 83.33% and accuracy = 84.62%. Our classification results suggested that the combinatory use of cardiovascular spectrum analysis and the proposed SVM classification of autonomic neural activity is a potentially useful clinical tool to classify the sepsis continuum into two distinct pathological groups of varying sepsis severity

  3. Computation Offloading for Frame-Based Real-Time Tasks under Given Server Response Time Guarantees

    Directory of Open Access Journals (Sweden)

    Anas S. M. Toma

    2014-11-01

    Full Text Available Computation offloading has been adopted to improve the performance of embedded systems by offloading the computation of some tasks, especially computation-intensive tasks, to servers or clouds. This paper explores computation offloading for real-time tasks in embedded systems, provided given response time guarantees from the servers, to decide which tasks should be offloaded to get the results in time. We consider frame-based real-time tasks with the same period and relative deadline. When the execution order of the tasks is given, the problem can be solved in linear time. However, when the execution order is not specified, we prove that the problem is NP-complete. We develop a pseudo-polynomial-time algorithm for deriving feasible schedules, if they exist.  An approximation scheme is also developed to trade the error made from the algorithm and the complexity. Our algorithms are extended to minimize the period/relative deadline of the tasks for performance maximization. The algorithms are evaluated with a case study for a surveillance system and synthesized benchmarks.

  4. Timing and position response of a block detector for fast neutron time-of-flight imaging

    International Nuclear Information System (INIS)

    Our research effort seeks to improve the spatial and timing performance of a block detector made of a pixilated plastic scintillator (EJ-200), first demonstrated as part of Oak Ridge National Laboratory's Advanced Portable Neutron Imaging System. Improvement of the position and time response is necessary to achieve better resolution and contrast in the images of shielded special nuclear material. Time-of-flight is used to differentiate between gamma and different sources of neutrons (e.g., transmission and fission neutrons). Factors limiting the timing and position performance of the neutron detector have been revealed through simulations and measurements. Simulations have suggested that the degradation in the ability to resolve pixels in the neutron detector is due to those interactions occurring near the light guide. The energy deposition within the neutron detector is shown to affect position performance and imaging efficiency. This examination details how energy cuts improve the position performance and degrade the imaging efficiency. Measurements have shown the neutron detector to have a timing resolution of σ=238 ps. The majority of this timing uncertainty is from the depth-of-interaction (DOI) of the neutron which is confirmed by simulations and analytical calculations

  5. Multivariate Analyses and Classification of Inertial Sensor Data to Identify Aging Effects on the Timed-Up-and-Go Test

    Science.gov (United States)

    Vervoort, Danique; Vuillerme, Nicolas; Kosse, Nienke; Hortobágyi, Tibor; Lamoth, Claudine J. C.

    2016-01-01

    Many tests can crudely quantify age-related mobility decrease but instrumented versions of mobility tests could increase their specificity and sensitivity. The Timed-up-and-Go (TUG) test includes several elements that people use in daily life. The test has different transition phases: rise from a chair, walk, 180° turn, walk back, turn, and sit-down on a chair. For this reason the TUG is an often used test to evaluate in a standardized way possible decline in balance and walking ability due to age and or pathology. Using inertial sensors, qualitative information about the performance of the sub-phases can provide more specific information about a decline in balance and walking ability. The first aim of our study was to identify variables extracted from the instrumented timed-up-and-go (iTUG) that most effectively distinguished performance differences across age (age 18–75). Second, we determined the discriminative ability of those identified variables to classify a younger (age 18–45) and older age group (age 46–75). From healthy adults (n = 59), trunk accelerations and angular velocities were recorded during iTUG performance. iTUG phases were detected with wavelet-analysis. Using a Partial Least Square (PLS) model, from the 72-iTUG variables calculated across phases, those that explained most of the covariance between variables and age were extracted. Subsequently, a PLS-discriminant analysis (DA) assessed classification power of the identified iTUG variables to discriminate the age groups. 27 variables, related to turning, walking and the stand-to-sit movement explained 71% of the variation in age. The PLS-DA with these 27 variables showed a sensitivity and specificity of 90% and 85%. Based on this model, the iTUG can accurately distinguish young and older adults. Such data can serve as a reference for pathological aging with respect to a widely used mobility test. Mobility tests like the TUG supplemented with smart technology could be used in clinical

  6. Multivariate Analyses and Classification of Inertial Sensor Data to Identify Aging Effects on the Timed-Up-and-Go Test.

    Science.gov (United States)

    Vervoort, Danique; Vuillerme, Nicolas; Kosse, Nienke; Hortobágyi, Tibor; Lamoth, Claudine J C

    2016-01-01

    Many tests can crudely quantify age-related mobility decrease but instrumented versions of mobility tests could increase their specificity and sensitivity. The Timed-up-and-Go (TUG) test includes several elements that people use in daily life. The test has different transition phases: rise from a chair, walk, 180° turn, walk back, turn, and sit-down on a chair. For this reason the TUG is an often used test to evaluate in a standardized way possible decline in balance and walking ability due to age and or pathology. Using inertial sensors, qualitative information about the performance of the sub-phases can provide more specific information about a decline in balance and walking ability. The first aim of our study was to identify variables extracted from the instrumented timed-up-and-go (iTUG) that most effectively distinguished performance differences across age (age 18-75). Second, we determined the discriminative ability of those identified variables to classify a younger (age 18-45) and older age group (age 46-75). From healthy adults (n = 59), trunk accelerations and angular velocities were recorded during iTUG performance. iTUG phases were detected with wavelet-analysis. Using a Partial Least Square (PLS) model, from the 72-iTUG variables calculated across phases, those that explained most of the covariance between variables and age were extracted. Subsequently, a PLS-discriminant analysis (DA) assessed classification power of the identified iTUG variables to discriminate the age groups. 27 variables, related to turning, walking and the stand-to-sit movement explained 71% of the variation in age. The PLS-DA with these 27 variables showed a sensitivity and specificity of 90% and 85%. Based on this model, the iTUG can accurately distinguish young and older adults. Such data can serve as a reference for pathological aging with respect to a widely used mobility test. Mobility tests like the TUG supplemented with smart technology could be used in clinical practice

  7. Multivariate Analyses and Classification of Inertial Sensor Data to Identify Aging Effects on the Timed-Up-and-Go Test.

    Directory of Open Access Journals (Sweden)

    Danique Vervoort

    Full Text Available Many tests can crudely quantify age-related mobility decrease but instrumented versions of mobility tests could increase their specificity and sensitivity. The Timed-up-and-Go (TUG test includes several elements that people use in daily life. The test has different transition phases: rise from a chair, walk, 180° turn, walk back, turn, and sit-down on a chair. For this reason the TUG is an often used test to evaluate in a standardized way possible decline in balance and walking ability due to age and or pathology. Using inertial sensors, qualitative information about the performance of the sub-phases can provide more specific information about a decline in balance and walking ability. The first aim of our study was to identify variables extracted from the instrumented timed-up-and-go (iTUG that most effectively distinguished performance differences across age (age 18-75. Second, we determined the discriminative ability of those identified variables to classify a younger (age 18-45 and older age group (age 46-75. From healthy adults (n = 59, trunk accelerations and angular velocities were recorded during iTUG performance. iTUG phases were detected with wavelet-analysis. Using a Partial Least Square (PLS model, from the 72-iTUG variables calculated across phases, those that explained most of the covariance between variables and age were extracted. Subsequently, a PLS-discriminant analysis (DA assessed classification power of the identified iTUG variables to discriminate the age groups. 27 variables, related to turning, walking and the stand-to-sit movement explained 71% of the variation in age. The PLS-DA with these 27 variables showed a sensitivity and specificity of 90% and 85%. Based on this model, the iTUG can accurately distinguish young and older adults. Such data can serve as a reference for pathological aging with respect to a widely used mobility test. Mobility tests like the TUG supplemented with smart technology could be used in

  8. A Hidden Markov Models Approach for Crop Classification: Linking Crop Phenology to Time Series of Multi-Sensor Remote Sensing Data

    Directory of Open Access Journals (Sweden)

    Sofia Siachalou

    2015-03-01

    Full Text Available Vegetation monitoring and mapping based on multi-temporal imagery has recently received much attention due to the plethora of medium-high spatial resolution satellites and the improved classification accuracies attained compared to uni-temporal approaches. Efficient image processing strategies are needed to exploit the phenological information present in temporal image sequences and to limit data redundancy and computational complexity. Within this framework, we implement the theory of Hidden Markov Models in crop classification, based on the time-series analysis of phenological states, inferred by a sequence of remote sensing observations. More specifically, we model the dynamics of vegetation over an agricultural area of Greece, characterized by spatio-temporal heterogeneity and small-sized fields, using RapidEye and Landsat ETM+ imagery. In addition, the classification performance of image sequences with variable spatial and temporal characteristics is evaluated and compared. The classification model considering one RapidEye and four pan-sharpened Landsat ETM+ images was found superior, resulting in a conditional kappa from 0.77 to 0.94 per class and an overall accuracy of 89.7%. The results highlight the potential of the method for operational crop mapping in Euro-Mediterranean areas and provide some hints for optimal image acquisition windows regarding major crop types in Greece.

  9. Real-time GPS Strategies for Rapid Response Applications

    Science.gov (United States)

    Johanson, I. A.; Dreger, D. S.

    2012-12-01

    High-rate, low-latency GPS data can make valuable contribution to both Earthquake Early Warning (EEW) and Rapid Response (RR) applications. While GPS will make is largest contribution to EEW in high magnitude earthquakes, it can provide valuable information to RR products for many more events, from moderate to high magnitude. In particular, static offsets from GPS provide information on the fault plane orientation and total slip in a finite slip inversion, which is used to produce Shakemap. Shakemap is a product that shows the estimated intensity of shaking around the epicentral area and is used by first responders to evaluate where damage is likely to have occurred. In this project, we investigate strategies for using GPS data for moderate earthquakes in California to produce estimates of static offsets and estimate a slip plane within minutes following an event. The 2007 M5.6 Alum Rock and 2004 M6.0 Parkfield earthquakes are used as test cases and the data is processed using Track and TrackRT. Multiple methods for measuring the static offsets from the displacement waveforms are tested, including differencing the pre- and post- earthquake median positions and a method involving pre- and post- earthquake line fitting. We also look into the effects of different types of starting geometry on the speed and accuracy of the non-linear fault plane determination process. We find that rapid post-processing with Track allows more robust static offset determination from these smaller earthquakes than real-time processing (as it exists today). Rapid post-processing can be finished and displacement waveforms made available within a couple minutes, well within the time threshold for other rapid products and providing essentially no delay to the final products. Nonetheless, this strategy still requires real-time transmission of data from the field to the lab so that it is available on demand following an event.

  10. Efficient Pairwise Multilabel Classification

    OpenAIRE

    Loza Mencía, Eneldo

    2013-01-01

    Multilabel classification learning is the task of learning a mapping between objects and sets of possibly overlapping classes and has gained increasing attention in recent times. A prototypical application scenario for multilabel classification is the assignment of a set of keywords to a document, a frequently encountered problem in the text classification domain. With upcoming Web 2.0 technologies, this domain is extended by a wide range of tag suggestion tasks and the trend definitely...

  11. Efficient multivariate sequence classification

    OpenAIRE

    Kuksa, Pavel P.

    2014-01-01

    Kernel-based approaches for sequence classification have been successfully applied to a variety of domains, including the text categorization, image classification, speech analysis, biological sequence analysis, time series and music classification, where they show some of the most accurate results. Typical kernel functions for sequences in these domains (e.g., bag-of-words, mismatch, or subsequence kernels) are restricted to {\\em discrete univariate} (i.e. one-dimensional) string data, such ...

  12. The Response Time of a Rotor System with a Disk-Type Magnetorheological Fluid Damper

    Science.gov (United States)

    Zhu, Changsheng

    The response time of a rotor system supported upon a disk-type magnetorheological fluid damper operating on shear mode is measured experimentally. The effects of rotating speed, step current and magnetic particle volume fraction, on the response time are dealt with. It is shown that the dynamic response can be described by first 10% response time and rapid response time. Generally, the first 10% response time and the rapid response time are in order of less than 0.1 second and 0.1~0.4 second. The magnetic field strength, magnetic particle volume fraction and power supply have a great effect on the response time. The response time in dropping step current is several times longer than that in applying step current. There is a zero initial delay time at either applying or dropping the current, which is caused by the magnetizing or de-magnetizing process.

  13. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  14. Improving OCD time to solution using Signal Response Metrology

    Science.gov (United States)

    Fang, Fang; Zhang, Xiaoxiao; Vaid, Alok; Pandev, Stilian; Sanko, Dimitry; Ramanathan, Vidya; Venkataraman, Kartik; Haupt, Ronny

    2016-03-01

    In recent technology nodes, advanced process and novel integration scheme have challenged the precision limits of conventional metrology; with critical dimensions (CD) of device reduce to sub-nanometer region. Optical metrology has proved its capability to precisely detect intricate details on the complex structures, however, conventional RCWA-based (rigorous coupled wave analysis) scatterometry has the limitations of long time-to-results and lack of flexibility to adapt to wide process variations. Signal Response Metrology (SRM) is a new metrology technique targeted to alleviate the consumption of engineering and computation resources by eliminating geometric/dispersion modeling and spectral simulation from the workflow. This is achieved by directly correlating the spectra acquired from a set of wafers with known process variations encoded. In SPIE 2015, we presented the results of SRM application in lithography metrology and control [1], accomplished the mission of setting up a new measurement recipe of focus/dose monitoring in hours. This work will demonstrate our recent field exploration of SRM implementation in 20nm technology and beyond, including focus metrology for scanner control; post etch geometric profile measurement, and actual device profile metrology.

  15. Joint Modeling of Ability and Differential Speed Using Responses and Response Times.

    Science.gov (United States)

    Fox, Jean-Paul; Marianti, Sukaesi

    2016-01-01

    With computerized testing, it is possible to record both the responses of test takers to test questions (i.e., items) and the amount of time spent by a test taker in responding to each question. Various models have been proposed that take into account both test-taker ability and working speed, with the many models assuming a constant working speed throughout the test. The constant working speed assumption may be inappropriate for various reasons. For example, a test taker may need to adjust the pace due to time mismanagement, or a test taker who started out working too fast may reduce the working speed to improve accuracy. A model is proposed here that allows for variable working speed. An illustration of the model using the Amsterdam Chess Test data is provided. PMID:27269482

  16. An Analysis of Variance Approach for the Estimation of Response Time Distributions in Tests

    Science.gov (United States)

    Attali, Yigal

    2010-01-01

    Generalizability theory and analysis of variance methods are employed, together with the concept of objective time pressure, to estimate response time distributions and the degree of time pressure in timed tests. By estimating response time variance components due to person, item, and their interaction, and fixed effects due to item types and…

  17. Near-Real-Time Analysis of Publicly Communicated Disaster Response Information

    Science.gov (United States)

    Girard, Trevor

    2015-04-01

    During a disaster situation the public will need to make critical actions regarding what to do, where to go, how to get there, and so on. The more informed the public is, the better actions they are able to make, resulting in reduced disaster impacts. The criteria for what information to provide the public needs to change depending on the specific needs of the disaster affected population. The method of dissemination also needs to match the communication channels that the public typically uses in disaster situations. This research project investigates the dynamic information needs of disaster affected populations and how information leads to actions. The purpose of the research project is to identify key indicators for measuring how well informed the public is during disasters. The indicators are limited to those which can be observed as communication is happening (i.e., in near-real-time). By doing so, the indicators can be analyzed as disaster situations unfold, deficiencies can be identified, and recommendations can be made to potentially improve communication while the response is still underway. The end goal of the research is to improve the ability of communicators to inform disaster affected communities. A classification scheme has been developed to categorize the information provided to the public during disasters. Under each category is a set of typical questions that the information should answer. These questions are the result of a best observed practice review of the information available during 11 disasters. For example, under the category 'Life Saving Response', the questions which should be answered are who is doing what (Evacuation, SAR), where and when, and the amount of the affected communities' needs being covered by these actions. Review of what questions remain unanswered acts as the first indicator, referred to as an 'Information Gap Analysis'. Comparative analysis of the information within categories, between categories, and between similar

  18. Processing of recognition information and additional cues: A model-based analysis of choice, confidence, and response time

    Directory of Open Access Journals (Sweden)

    Andreas Glockner

    2011-02-01

    Full Text Available Research on the processing of recognition information has focused on testing the recognition heuristic (RH. On the aggregate, the noncompensatory use of recognition information postulated by the RH was rejected in several studies, while RH could still account for a considerable proportion of choices. These results can be explained if either a a part of the subjects used RH or b nobody used it but its choice predictions were accidentally in line with predictions of the strategy used. In the current study, which exemplifies a new approach to model testing, we determined individuals' decision strategies based on a maximum-likelihood classification method, taking into account choices, response times and confidence ratings simultaneously. Unlike most previous studies of the RH, our study tested the RH under conditions in which we provided information about cue values of unrecognized objects (which we argue is fairly common and thus of some interest. For 77.5% of the subjects, overall behavior was best explained by a compensatory parallel constraint satisfaction (PCS strategy. The proportion of subjects using an enhanced RH heuristic (RHe was negligible (up to 7.5%; 15% of the subjects seemed to use a take the best strategy (TTB. A more-fine grained analysis of the supplemental behavioral parameters conditional on strategy use supports PCS but calls into question process assumptions for apparent users of RH, RHe, and TTB within our experimental context. Our results are consistent with previous literature highlighting the importance of individual strategy classification as compared to aggregated analyses.

  19. Fertility in Gyr Cows (Bos indicus) with Fixed Time Artificial Insemination and Visual Estrus Detection Using a Classification Table

    Science.gov (United States)

    Ramírez-Iglesia, Lilido Nelson; Roman Bravo, Rafael María; Díaz de Ramirez, Adelina; Torres, Leandro J.

    2014-01-01

    The aim of this research was to compare two artificial insemination protocols (AIP): hormonal synchronization with fixed time artificial insemination (SC-FTAI) and the use of a table based on visual observation of estrus signs (VO) in order to identify cows in natural or spontaneous estrus being assigned to AI (NSE-IA). Two groups were formed: in the first group 109 cows were assigned to SC-FTAI, in which a commercial protocol is used; the second one included 108 randomly chosen cows, which were assigned to NSE-AI and in this group a modified table was used. Response variable was first service fertility rate (FSF), which was coded 1 for pregnant and 0 for empty. Predictor variables were AIP, postpartum anestrus, daily milk yield, body condition score at AI and calving number. Statistical analyses included association chi-square tests and logistic regression. Results showed an overall 41.94% FSF and a significant association was detected (P 0.05). The odds ratio for the effect of AIP was only 1.050, suggesting no differences in FSF between groups. The NSE-AI protocol can enhance both the technique of VO and reproductive efficiency. Further validation of the table is required. PMID:26464929

  20. Planck 2013 results. VII. HFI time response and beams

    DEFF Research Database (Denmark)

    Planck Collaboration,; Ade, P. A. R.; Aghanim, N.;

    2013-01-01

    This paper characterizes the effective beams, the effective beam window functions (EBWF) and the associated errors for the Planck High Frequency Instrument (HFI) detectors. The effective beam is the angular response including the effect of the optics, detectors, data processing and the scan strat...

  1. Modeling an Application's Theoretical Minimum and Average Transactional Response Times

    Energy Technology Data Exchange (ETDEWEB)

    Paiz, Mary Rose [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-04-01

    The theoretical minimum transactional response time of an application serves as a ba- sis for the expected response time. The lower threshold for the minimum response time represents the minimum amount of time that the application should take to complete a transaction. Knowing the lower threshold is beneficial in detecting anomalies that are re- sults of unsuccessful transactions. On the converse, when an application's response time falls above an upper threshold, there is likely an anomaly in the application that is causing unusual performance issues in the transaction. This report explains how the non-stationary Generalized Extreme Value distribution is used to estimate the lower threshold of an ap- plication's daily minimum transactional response time. It also explains how the seasonal Autoregressive Integrated Moving Average time series model is used to estimate the upper threshold for an application's average transactional response time.

  2. Quality classification of Spanish olive oils by untargeted gas chromatography coupled to hybrid quadrupole-time of flight mass spectrometry with atmospheric pressure chemical ionization and metabolomics-based statistical approach.

    Science.gov (United States)

    Sales, C; Cervera, M I; Gil, R; Portolés, T; Pitarch, E; Beltran, J

    2017-02-01

    The novel atmospheric pressure chemical ionization (APCI) source has been used in combination with gas chromatography (GC) coupled to hybrid quadrupole time-of-flight (QTOF) mass spectrometry (MS) for determination of volatile components of olive oil, enhancing its potential for classification of olive oil samples according to their quality using a metabolomics-based approach. The full-spectrum acquisition has allowed the detection of volatile organic compounds (VOCs) in olive oil samples, including Extra Virgin, Virgin and Lampante qualities. A dynamic headspace extraction with cartridge solvent elution was applied. The metabolomics strategy consisted of three different steps: a full mass spectral alignment of GC-MS data using MzMine 2.0, a multivariate analysis using Ez-Info and the creation of the statistical model with combinations of responses for molecular fragments. The model was finally validated using blind samples, obtaining an accuracy in oil classification of 70%, taking the official established method, "PANEL TEST", as reference. PMID:27596432

  3. Time response of TOF spectrometer to light and heavy particles

    International Nuclear Information System (INIS)

    Comparing time of flight (TOF) values for α particles and fission fragments measured at different distances between the start- and stop detector we have obtained 60 ps as the upper limit for the TOF error resulting from the assumption of equal and linear time calibrations for both types of particles. While the 60 ps limit relates only to the specific spectrometer, the problem and the suggested verification technique are of general interest

  4. Integrated response and transit time distributions of watersheds by combining hydrograph separation and long-term transit time modeling

    Directory of Open Access Journals (Sweden)

    M. C. Roa-García

    2010-01-01

    Full Text Available We present a new modeling approach analyzing and predicting the Transit Time Distribution (TTD and the Response Time Distribution (RTD from hourly to annual time scales as two distinct hydrological processes. The model integrates Isotope Hydrograph Separation (IHS and the Instantaneous Unit Hydrograph (IUH approach as a tool to provide a more realistic description of transit and response time of water in catchments. Individual event simulations and parameterizations were combined with long-term baseflow simulation and parameterizations to provide a comprehensive picture of the catchment response for a long time span for the hydraulic and isotopic processes. The proposed method was tested in three Andean headwater catchments to compare the effects of land use on hydrological response and solute transport. Results show that the characteristics of events and antecedent conditions have a significant influence on TTD and RTD, but in general the RTD of the grassland dominated catchment is concentrated in the shorter time spans and has a higher cumulative TTD, while the forest dominated catchment has a relatively longer response distribution and lower cumulative TTD. The catchment where wetlands concentrate shows a flashier response, but wetlands also appear to contribute to prolong transit time.

  5. Using Response Time to Detect Item Preknowledge in Computer-Based Licensure Examinations

    Science.gov (United States)

    Qian, Hong; Staniewska, Dorota; Reckase, Mark; Woo, Ada

    2016-01-01

    This article addresses the issue of how to detect item preknowledge using item response time data in two computer-based large-scale licensure examinations. Item preknowledge is indicated by an unexpected short response time and a correct response. Two samples were used for detecting item preknowledge for each examination. The first sample was from…

  6. Modeling and predicting measured response time of cloud-based web services using long-memory time series

    OpenAIRE

    Nourikhah, Hossein; Akbari, Mohammad Kazem; Kalantari, Mohammad

    2016-01-01

    Predicting cloud performance from user's perspective is a complex task, because of several factors involved in providing the service to the consumer. In this work, the response time of 10 real-world services is analyzed. We have observed long memory in terms of the measured response time of the CPU-intensive services and statistically verified this observation using estimators of the Hurst exponent. Then, na\\"ive, mean, autoregressive integrated moving average (ARIMA) and autoregressive fract...

  7. Overeating at dinner time among Japanese workers: Is overeating related to stress response and late dinner times?

    Science.gov (United States)

    Suzuki, Akiko; Sakurazawa, Hirofumi; Fujita, Takanori; Akamatsu, Rie

    2016-06-01

    There are several known risk factors for overeating, including negative feelings and hunger. It was hypothesized that overtime work is associated with stress responses and later dinner times, leading to longer periods of time without eating, and that this, in turn, leads to a strong experience of hunger and consequent overeating at dinner. The aim of this study was to examine relationships among overeating at dinner, stress responses (e.g., fatigue, anxiety, and depression), and dinner times in Japanese male workers. In December 2012, 255 Japanese male workers at a leasing company completed a self-report questionnaire about overeating at dinner, psychological stress responses, physical stress responses, and dinner times. Each worker was sent an email with a link to the questionnaire website, where his answers were collected. Relationships between overeating at dinner and lifestyle issues were investigated using multiple linear regression analysis treating overeating as a dependent variable. Factors related to overeating at dinner included psychological stress response (β = 0.251 p < 0.001) and dinner time (β = 0.220, p = 0.004). These cross-sectional data suggest that overeating at dinner is related to dinner time in men and to stress responses. PMID:26923743

  8. Time-Varying Affective Response for Humanoid Robots

    Science.gov (United States)

    Moshkina, Lilia; Arkin, Ronald C.; Lee, Jamee K.; Jung, Hyunryong

    This paper describes the design of a complex time-varying affective architecture. It is an expansion of the TAME architecture (traits, attitudes, moods, and emotions) as applied to humanoid robotics. It particular it is intended to promote effective human-robot interaction by conveying the robot’s affective state to the user in an easy-to-interpret manner.

  9. A non-contact method based on multiple signal classification algorithm to reduce the measurement time for accurately heart rate detection

    Science.gov (United States)

    Bechet, P.; Mitran, R.; Munteanu, M.

    2013-08-01

    Non-contact methods for the assessment of vital signs are of great interest for specialists due to the benefits obtained in both medical and special applications, such as those for surveillance, monitoring, and search and rescue. This paper investigates the possibility of implementing a digital processing algorithm based on the MUSIC (Multiple Signal Classification) parametric spectral estimation in order to reduce the observation time needed to accurately measure the heart rate. It demonstrates that, by proper dimensioning the signal subspace, the MUSIC algorithm can be optimized in order to accurately assess the heart rate during an 8-28 s time interval. The validation of the processing algorithm performance was achieved by minimizing the mean error of the heart rate after performing simultaneous comparative measurements on several subjects. In order to calculate the error the reference value of heart rate was measured using a classic measurement system through direct contact.

  10. Meteorological data assimilation for real-time emergency response

    International Nuclear Information System (INIS)

    The US Department of Energy's Atmospheric Release Advisory Capability (ARAC) provides real-time dose assessments of airborne pollutant releases. Diverse data assimilation techniques are required to meet the needs of a new generation of ARAC models and to take advantage of the rapidly expanding availability of meteorological data. We are developing a hierarchy of algorithms to provide gridded meteorological fields which can be used to drive dispersion codes or to provide initial fields for mesoscale models. Data to be processed include winds, temperature, moisture, and turbulence

  11. Quantifying the Response Time of a Lake–Groundwater Interacting System to Climatic Perturbation

    OpenAIRE

    Yicheng Gong; Ganming Liu; Schwartz, Franklin W.

    2015-01-01

    Response time, describing how quickly a disturbed system would reach a new equilibrium, has been helpful to hydrogeologists in characterizing and understanding the hydrogeological systems. This study examined the complex response times associated with lake–groundwater perturbed by climate. Simulated hydraulic heads and lake stage values derived from a 3-D, MODFLOW-based model were used to calculate the response times for a closed, groundwater-fed lake system. Although obviously coupled, the r...

  12. Response Time as Self-Schema Indicator : Implications for Personality Assessment

    OpenAIRE

    Hedlund, Lars-Erik

    2010-01-01

    The focal objective of this thesis was to examine the potential advantage of introducing the self-schema concept, indexed by response time, into personality assessment. The basic rationale for the use of response time is that a self-schema facilitates response time for self-referent information as it permits people to make assessments easier and automatic. A self-schema is a cognitive structure containing the generic knowledge that people have about themselves, influencing all aspects of the ...

  13. Early Flood Detection for Rapid Humanitarian Response: Harnessing Near Real-Time Satellite and Twitter Signals

    OpenAIRE

    Brenden Jongman; Jurjen Wagemaker; Beatriz Revilla Romero; Erin Coughlan de Perez

    2015-01-01

    Humanitarian organizations have a crucial role in response and relief efforts after floods. The effectiveness of disaster response is contingent on accurate and timely information regarding the location, timing and impacts of the event. Here we show how two near-real-time data sources, satellite observations of water coverage and flood-related social media activity from Twitter, can be used to support rapid disaster response, using case-studies in the Philippines and Pakistan. For these count...

  14. 22 CFR 9.8 - Classification challenges.

    Science.gov (United States)

    2010-04-01

    ... challenges to classification actions shall be in writing to an original classification authority (OCA) with.... The Department (either the OCA or IPS) shall provide an initial response in writing within 60 days....

  15. Method for reducing response time in sensor measurement.

    Science.gov (United States)

    Casas, Oscar; Rillo, Francesc I

    2009-08-01

    Transients are present in sensor and instrumentation systems. They are caused by energy transference and are typically modeled as first-order systems. If too long, transients may suppose a critical factor for these systems unless they are analyzed (e.g., in terms of consumption). This work presents a new method for estimating the final value of a first-order system transient. Since this problem may be harmful, mainly to autonomous systems, the method equations are composed of simple operations that can be implemented on microcontrollers or similar interfaces with low computational capacity. The experimental results validate the theoretical models of the method and prove that, when the system coexists with disturbances, it is possible to estimate the final value in around 60% of the time we would have to wait until reaching it, in the worst case scenario. PMID:19725676

  16. Digital timing algorithms applied to fast scintillators response

    International Nuclear Information System (INIS)

    The future Facility for Antiproton and Ion Research (FAIR) will house the calorimeter and spectrometer CALIFA, whose design, construction and testing are currently being carried out by the R3B collaboration. The mentioned calorimeter is an array of scintillation detectors displayed in a barrel configuration, which covers the total solid angle. These new fast scintillation materials have been developed in last few years and their main interest lies on their versatility, which allows their use both for applications and fundamental research. In the same way, fast digitizers let the collection of signals at increasingly higher sampling frequencies. Our research takes advantage of these fair properties and is therefore focused on the analysis of digitized pulses for several aims: understanding the behaviour of radiation inside new fast scintillators and the development or improvement of digital algorithms which yield accurate resolution for fast timing and may be also applied to particle identification.

  17. Short Text Classification: A Survey

    Directory of Open Access Journals (Sweden)

    Ge Song

    2014-05-01

    Full Text Available With the recent explosive growth of e-commerce and online communication, a new genre of text, short text, has been extensively applied in many areas. So many researches focus on short text mining. It is a challenge to classify the short text owing to its natural characters, such as sparseness, large-scale, immediacy, non-standardization. It is difficult for traditional methods to deal with short text classification mainly because too limited words in short text cannot represent the feature space and the relationship between words and documents. Several researches and reviews on text classification are shown in recent times. However, only a few of researches focus on short text classification. This paper discusses the characters of short text and the difficulty of short text classification. Then we introduce the existing popular works on short text classifiers and models, including short text classification using sematic analysis, semi-supervised short text classification, ensemble short text classification, and real-time classification. The evaluations of short text classification are analyzed in our paper. Finally we summarize the existing classification technology and prospect for development trend of short text classification

  18. Superparamagnetic iron oxide; Clinical time-response study

    Energy Technology Data Exchange (ETDEWEB)

    Gandon, Yves; Heautot, J.F.; Brunet, Frederic; Carsin, Michel (Hopital Pontchaillou, Rennes (France). Departement d' Imagerie Medicale); Guyader, Dominique; Deugnier, Yves (Hopital Pontchaillou, Rennes (France). Service de Medecine Interne et Hepatologie)

    Superparamagnetic iron oxide (AMI 25) is a promising new contrast agent for imaging the reticuloendothelial-system. Iron oxide crystals possess a large magnetic susceptibility and enhance proton relaxation rates, especially transverse relaxation (T2). In order to guide the clinical utilization of this contrast media 4 patients with malignant lesions of the liver are analyzed before and after slow intravenous administration (20 {mu}mol Fe/kg) of AMI 25. Two magnetic resonance (MR) sequences are performed at different times using 0.35 T magnet. MR signal-to-noise ratio (SNR) of the reticuloendothelial-system (particularly the liver SNR) decrease promptly. The maximum decrease in SNR (67-72 percent for the liver, 46-65 percent for the spleen, 23-41 percent for the bone marrow) is observed 3 h after injection (P<0.01). However, except the peak of contrast enhancement in T1-weighted sequence of splenic tissue, the curve describes a plateau within 30 min and 6 h, allowing a delay between injection and imaging. T2-weighted sequences give a greater contrast-to-noise ratio (CNR) by adding the spontaneous tumor contrast to the effect yielded by AMI 25. These results suggest that images must be acquired between 1 and 6 h after intravenous administration of superparamagnetic iron oxide. (author). 18 refs.; 6 figs.

  19. Classification of Satellite Derived Chlorophyll a Space-Time Series by Means of Quantile Regression: An Application to the Adriatic Sea

    Science.gov (United States)

    Girardi, P.; Pastres, R.; Gaetan, C.; Mangin, A.; Taji, M. A.

    2015-12-01

    In this paper, we present the results of a classification of Adriatic waters, based on spatial time series of remotely sensed Chlorophyll type-a. The study was carried out using a clustering procedure combining quantile smoothing and an agglomerative clustering algorithms. The smoothing function includes a seasonal term, thus allowing one to classify areas according to “similar” seasonal evolution, as well as according to “similar” trends. This methodology, which is here applied for the first time to Ocean Colour data, is more robust with respect to other classical methods, as it does not require any assumption on the probability distribution of the data. This approach was applied to the classification of an eleven year long time series, from January 2002 to December 2012, of monthly values of Chlorophyll type-a concentrations covering the whole Adriatic Sea. The data set was made available by ACRI (http://hermes.acri.fr) in the framework of the Glob-Colour Project (http://www.globcolour.info). Data were obtained by calibrating Ocean Colour data provided by different satellite missions, such as MERIS, SeaWiFS and MODIS. The results clearly show the presence of North-South and West-East gradient in the level of Chlorophyll, which is consistent with literature findings. This analysis could provide a sound basis for the identification of “water bodies” and of Chlorophyll type-a thresholds which define their Good Ecological Status, in terms of trophic level, as required by the implementation of the Marine Strategy Framework Directive. The forthcoming availability of Sentinel-3 OLCI data, in continuity of the previous missions, and with perspective of more than a 15-year monitoring system, offers a real opportunity of expansion of our study as a strong support to the implementation of both the EU Marine Strategy Framework Directive and the UNEP-MAP Ecosystem Approach in the Mediterranean.

  20. Response

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Neuromorphic silicon chips have been developed over the last 30 years, inspired by the design of biological nervous systems and offering an alternative paradigm for computation, with real-time massively parallel operation and potentially large power savings with respect to conventional computing architectures. I will present the general principles with a brief investigation of the design choices that have been explored, and I'll discuss how such hardware has been applied to problems such as classification.

  1. Influence on measuring ionization chamber's time response speed with charge integration amplifying circuit

    International Nuclear Information System (INIS)

    The time response speed of measuring amplifier directly influences the research on ionization chamber's time response speed. The reasons why the measuring circuit was designed with charge integration amplifier were presented. The mechanism of emerging stepped current signal of ionization chamber unit irradiated by a stable radiation source was analyzed. The method of studying amplifier time response by measuring the changing process of current signal was proposed. The relationship of the amplifier's time response speed with the detector unit interelectrode capacitance, the amplifier's input protecting resistance and its feedback integral capacitance was studied through experiment. It is concluded that the amplifier's time response speed is concerned with the constant time of ionization chamber unit interelectrode capacitance and protecting resistance. And it is not concerned with the feedback integral capacitance. It provides theoretical guidance on designing ionization chamber and measuring circuit. (authors)

  2. Real-Time Nearfield Acoustic Holography: Implementation of the Direct and Inverse Impulse Responses in the Time-Wavenumber Domain

    CERN Document Server

    Thomas, Jean-Hugh; Paillasseur, Sébastien; Pascal, Jean-Claude

    2008-01-01

    The aim of the study is to demonstrate that some methods are more relevant for implementing the Real-Time Nearfield Acoustic Holography than others. First by focusing on the forward propagation problem, different approaches are compared to build the impulse response to be used. One of them in particular is computed by an inverse Fourier transform applied to the theoretical transfer function for propagation in the frequency-wavenumber domain. Others are obtained by directly sampling an analytical impulse response in the time-wavenumber domain or by additional low-pass filtering. To estimate the performance of each impulse response, a simulation test involving several monopoles excited by non stationary signals is presented and some features are proposed to assess the accuracy of the temporal signals resulting from reconstruction processing on a forward plane. Then several inverse impulse responses used to solve the inverse problem, which consists in back propagating the acoustic signals acquired by the microph...

  3. A Time Series Regime Classification Approach for Short-Term Forecasting; Identificacion de Mecanismos en Series Temporales para la Prediccion a Corto Plazo

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, C. J.

    2010-03-08

    Abstract: This technical report is focused on the analysis of stochastic processes that switch between different dynamics (also called regimes or mechanisms) over time. The so-called Switching-regime models consider several underlying functions instead of one. In this case, a classification problem arises as the current regime has to be assessed at each time-step. The identification of the regimes allows the performance of regime-switching models for short-term forecasting purposes. Within this framework, identifying different regimes showed by time-series is the aim of this work. The proposed approach is based on a statistical tool called Gamma-test. One of the main advantages of this methodology is the absence of a mathematical definition for the different underlying functions. Applications with both simulated and real wind power data have been considered. Results on simulated time series show that regimes can be successfully identified under certain hypothesis. Nevertheless, this work highlights that further research has to be done when considering real wind power time-series, which usually show different behaviours (e.g. fluctuations or ramps, followed by low variance periods). A better understanding of these events eventually will improve wind power forecasting. (Author) 15 refs.

  4. Group classification of the Sachs equations for a radiating axisymmetric, non-rotating, vacuum space-time

    CERN Document Server

    Ibragimov, N H; Wessels, E J H; Ellis, George F. R.; Ibragimov, Nail H.; Wessels, Ewald J. H.

    2006-01-01

    We carry out a Lie group analysis of the Sachs equations for a time-dependent axisymmetric non-rotating space-time in which the Ricci tensor vanishes. These equations, which are the first two members of the set of Newman-Penrose equations, define the characteristic initial-value problem for the space-time. We find a particular form for the initial data such that these equations admit a Lie symmetry, and so defines a geometrically special class of such spacetimes. These should additionally be of particular physical interest because of this special geometric feature.

  5. Change of Exposure Response over Time and Long-Term Risk of Silicosis among a Cohort of Chinese Pottery Workers

    Directory of Open Access Journals (Sweden)

    Yuewei Liu

    2011-07-01

    Full Text Available An analysis was conducted on a cohort of Chinese pottery workers to estimate the exposure-response relationship between respirable crystalline silica dust exposure and the incidence of radiographically diagnosed silicosis, and to estimate the long-term risk of developing silicosis until the age of 65. The cohort comprised 3,250 employees with a median follow-up duration of around 37 years. Incident cases of silicosis were identified via silicosis registries (Chinese X-ray stage I, similar to International Labor Organisation classification scheme profusion category 1/1. Individual exposure to respirable crystalline silica dust was estimated based on over 100,000 historical dust measurements. The association between dust exposure, incidence and long-time risk of silicosis was quantified by Poisson regression analysis adjusted for age and smoking. The risk of silicosis depended not only on the cumulative respirable crystalline silica dust exposures, but also on the time-dependent respirable crystalline silica dust exposure pattern (long-term average concentration, highest annual concentration ever experienced and time since first exposure. A long-term “excess” risk of silicosis of approximately 1.5/1,000 was estimated among workers with all annual respirable crystalline silica dust concentration estimates less than 0.1 mg/m3, using the German measurement strategy. This study indicates the importance of proper consideration of exposure information in risk quantification in epidemiological studies.

  6. An automated sleep-state classification algorithm for quantifying sleep timing and sleep-dependent dynamics of electroencephalographic and cerebral metabolic parameters

    Directory of Open Access Journals (Sweden)

    Rempe MJ

    2015-09-01

    Full Text Available Michael J Rempe,1,2 William C Clegern,2 Jonathan P Wisor2 1Mathematics and Computer Science, Whitworth University, Spokane, WA, USA; 2College of Medical Sciences and Sleep and Performance Research Center, Washington State University, Spokane, WA, USAIntroduction: Rodent sleep research uses electroencephalography (EEG and electromyography (EMG to determine the sleep state of an animal at any given time. EEG and EMG signals, typically sampled at >100 Hz, are segmented arbitrarily into epochs of equal duration (usually 2–10 seconds, and each epoch is scored as wake, slow-wave sleep (SWS, or rapid-eye-movement sleep (REMS, on the basis of visual inspection. Automated state scoring can minimize the burden associated with state and thereby facilitate the use of shorter epoch durations.Methods: We developed a semiautomated state-scoring procedure that uses a combination of principal component analysis and naïve Bayes classification, with the EEG and EMG as inputs. We validated this algorithm against human-scored sleep-state scoring of data from C57BL/6J and BALB/CJ mice. We then applied a general homeostatic model to characterize the state-dependent dynamics of sleep slow-wave activity and cerebral glycolytic flux, measured as lactate concentration.Results: More than 89% of epochs scored as wake or SWS by the human were scored as the same state by the machine, whether scoring in 2-second or 10-second epochs. The majority of epochs scored as REMS by the human were also scored as REMS by the machine. However, of epochs scored as REMS by the human, more than 10% were scored as SWS by the machine and 18 (10-second epochs to 28% (2-second epochs were scored as wake. These biases were not strain-specific, as strain differences in sleep-state timing relative to the light/dark cycle, EEG power spectral profiles, and the homeostatic dynamics of both slow waves and lactate were detected equally effectively with the automated method or the manual scoring

  7. 医院社会责任行为的分级研究%Study on Classification of Hospital Social Responsibility Behaviors

    Institute of Scientific and Technical Information of China (English)

    徐爱军; 施燕吉; 杨学伟

    2012-01-01

    目的:为医院社会责任行为分级的理论及实践研究提供参考.方法:基于国内外学者观点的文献研究和内容分析法,对通过大样本问卷调查和德尔菲法所最终确定的13种医院社会责任行为进行分级,并总结分级特征.结果与结论:把13种医院社会责任行为分为3个层级,其中初级医院社会责任行为有:提供优质的医疗服务、坏账处理、承担突发事件的救援任务等6项;中级医院社会责任行为有:具有外部正效应的医疗服务、价格优惠等3项;高级医院社会责任行为有:慈善医疗、教育科研、健康促进服务等4项.分级具备效益维度强调活动结果、活动性质维度相对和分级模型为动态的特征.%OBJECTIVE: To provide reference for theory and practice study of classification of hospital social responsibilities behavior. METHODS: Based on literature research and content analysis method, 13 kinds of hospital social responsibilities behavior were classified by iarge-scale sample and Delphi method and the characteristics of classification were summarized. RESULTS & CONCLUSIONS: The 13 kinds of behaviors of the hospital social responsibility are divided into 3 levels. That is, primary level: providing excellent medical services, bad debts, undertaking rescues under emergency; intermediate level: medical services with positive external effects and favorable price; senior level: charity care, education and research, health improvement and health education. The classification of behaviors is characterized with results-based, relative and dynamic classifying model.

  8. Posterior Predictive Checks for Conditional Independence between Response Time and Accuracy

    Science.gov (United States)

    Bolsinova, Maria; Tijmstra, Jesper

    2016-01-01

    Conditional independence (CI) between response time and response accuracy is a fundamental assumption of many joint models for time and accuracy used in educational measurement. In this study, posterior predictive checks (PPCs) are proposed for testing this assumption. These PPCs are based on three discrepancy measures reflecting different…

  9. The Simplest Complete Model of Choice Response Time: Linear Ballistic Accumulation

    Science.gov (United States)

    Brown, Scott D.; Heathcote, Andrew

    2008-01-01

    We propose a linear ballistic accumulator (LBA) model of decision making and reaction time. The LBA is simpler than other models of choice response time, with independent accumulators that race towards a common response threshold. Activity in the accumulators increases in a linear and deterministic manner. The simplicity of the model allows…

  10. Heat shock factors in carrot: genome-wide identification, classification, and expression profiles response to abiotic stress.

    Science.gov (United States)

    Huang, Ying; Li, Meng-Yao; Wang, Feng; Xu, Zhi-Sheng; Huang, Wei; Wang, Guang-Long; Ma, Jing; Xiong, Ai-Sheng

    2015-05-01

    Heat shock factors (HSFs) play key roles in the response to abiotic stress in eukaryotes. In this study, 35 DcHSFs were identified from carrot (Daucus carota L.) based on the carrot genome database. All 35 DcHSFs were divided into three classes (A, B, and C) according to the structure and phylogenetic relationships of four different plants, namely, Arabidopsis thaliana, Vitis vinifera, Brassica rapa, and Oryza sativa. Comparative analysis of algae, gymnosperms, and angiosperms indicated that the numbers of HSF transcription factors were related to the plant's evolution. The expression profiles of five DcHsf genes (DcHsf 01, DcHsf 02, DcHsf 09, DcHsf 10, and DcHsf 16), which selected from each subfamily (A, B, and C), were detected by quantitative real-time PCR under abiotic stresses (cold, heat, high salinity, and drought) in two carrot cultivars, D. carota L. cvs. Kurodagosun and Junchuanhong. The expression levels of DcHsfs were markedly increased by heat stress, except that of DcHsf 10, which was down regulated. The expression profiles of different DcHsfs in the same class also differed under various stress treatments. The expression profiles of these DcHsfs were also different in tissues of two carrot cultivars. This study is the first to identify and characterize the DcHSF family transcription factors in plants of Apiaceae using whole-genome analysis. The results of this study provide an in-depth understanding of the DcHSF family transcription factors' structure, function, and evolution in carrot. PMID:25403331

  11. Minimizing Response Time and Effective Utilization of I/O-bound Processes using “Approximate Zero Response Algorithm

    Directory of Open Access Journals (Sweden)

    Dinesh Gupta

    2012-03-01

    Full Text Available Various sheduling algorithm are available forthe operating system to improve CPU utilization.Different scheduling algorithms have differentproperties that work on different schedulingcriterias and the choice of a particular algorithmmay favor one class of processes over another.SJF gives minimum average waiting time for agiven set of processes. The Round Robinalgorithm decreases the response time. In thispaper we have proposed an algorithm which hasresponse time aproximately zero and itincreases the efficiency of I/O boundedprocess.

  12. Time-varying effect models for ordinal responses with applications in substance abuse research

    OpenAIRE

    Dziak, John J.; Li, Runze; Zimmerman, Marc A.; Buu, Anne

    2014-01-01

    Ordinal responses are very common in longitudinal data collected from substance abuse research or other behavioral research. This study develops a new statistical model with free SAS macro’s that can be applied to characterize time-varying effects on ordinal responses. Our simulation study shows that the ordinal-scale time-varying effects model has very low estimation bias and sometimes offers considerably better performance when fitting data with ordinal responses than a model that treats th...

  13. Response time testing of temperature and pressure sensors in nuclear power plants

    International Nuclear Information System (INIS)

    Response time measurement tests are performed on most safety-related temperature and pressure sensors in a majority of the nuclear power plants in the United States. These tests, performed once every fuel cycle, insure that safety-related instrument channels will respond in a timely manner during design basis accidents. This paper provides a review of modern methods that are used for response time measurement, and example results from testing of temperature and pressure sensors in nuclear on-line testing at process operating conditions and thereby provide information about the actual in-situ performance of the sensors. These methods are referred to as the Loop Current Step Response (LCSR) test, which is used for response time testing of temperature sensors, and noise analysis test, which is used for response time testing of pressure, level and flow transmitters. (Author)

  14. Strategic Classification

    OpenAIRE

    Hardt, Moritz; Megiddo, Nimrod; Papadimitriou, Christos; Wootters, Mary

    2015-01-01

    Machine learning relies on the assumption that unseen test instances of a classification problem follow the same distribution as observed training data. However, this principle can break down when machine learning is used to make important decisions about the welfare (employment, education, health) of strategic individuals. Knowing information about the classifier, such individuals may manipulate their attributes in order to obtain a better classification outcome. As a result of this behavior...

  15. More is not Always Better: The Relation between Item Response and Item Response Time in Raven’s Matrices

    Directory of Open Access Journals (Sweden)

    Frank Goldhammer

    2015-03-01

    Full Text Available The role of response time in completing an item can have very different interpretations. Responding more slowly could be positively related to success as the item is answered more carefully. However, the association may be negative if working faster indicates higher ability. The objective of this study was to clarify the validity of each assumption for reasoning items considering the mode of processing. A total of 230 persons completed a computerized version of Raven’s Advanced Progressive Matrices test. Results revealed that response time overall had a negative effect. However, this effect was moderated by items and persons. For easy items and able persons the effect was strongly negative, for difficult items and less able persons it was less negative or even positive. The number of rules involved in a matrix problem proved to explain item difficulty significantly. Most importantly, a positive interaction effect between the number of rules and item response time indicated that the response time effect became less negative with an increasing number of rules. Moreover, exploratory analyses suggested that the error type influenced the response time effect.

  16. Next-Generation Library Catalogs and the Problem of Slow Response Time

    OpenAIRE

    Brown-Sica, Margaret; Beall, Jeffrey; mchale, nina

    2010-01-01

    Response time as defined for this study is the time that it takes for all files that constitute a single webpage to travel across the Internet from a Web server to the end user’s browser. In this study, the authors tested response times on queries for identical items in five different library catalogs, one of them a next-generation (NextGen) catalog. The authors also discuss acceptable response time and how it may affect the discovery process. They suggest that librari...

  17. Time-domain superposition method for fitting multi-damping response spectra

    International Nuclear Information System (INIS)

    In this paper, a method of superposing narrow-band time history in time domain is proposed, which can be utilized to enhance the fitting precision of design ground shaking time history to multi-damping specified single-damping target response spectrum; and then by superposing narrowband time histories in time domain, the initial acceleration time history is further modulated, to improve its fitting precision to the multi-damping target response spectra. The numerical examples demonstrated that the design ground motions generated by the proposed method possess very high fitting precision to the multi-damping target spectra. (authors)

  18. Impact of insufficient energy content in the design time history on the structure response

    International Nuclear Information System (INIS)

    In the design of nuclear power plants, it is often desirable to use the time history method in the soil-structure interaction analysis to determine the plant floor response to seismic loads. Because many design criteria are specified in terms of design response spectra, the artificial time history needs to be generated under the requirement that the response spectra of the artificial history should envelop the given design response spectra. However, recent studies indicate that the artificial time history used in the plant design may have insufficient energy in the frequency range of interest, even though the response spectra of the design time history closely envelop the design response spectra. This paper presents an investigation of the effects of the insufficient energy content in the design time history on the response of the soil-structure system. Numerical studies were carried out. Both the real earthquake records and the artificial time histories were used as the input motions in a simple lumped-mass soil-structure interaction model. The results obtained from this study provide a better understanding of the effects of the insufficient energy content in the design time history on the structural response

  19. Improving Student Question Classification

    Science.gov (United States)

    Heiner, Cecily; Zachary, Joseph L.

    2009-01-01

    Students in introductory programming classes often articulate their questions and information needs incompletely. Consequently, the automatic classification of student questions to provide automated tutorial responses is a challenging problem. This paper analyzes 411 questions from an introductory Java programming course by reducing the natural…

  20. Real-Time Estimation of the Distribution of Brake Response Times for an Individual Driver Using Vehicular Ad Hoc Network

    OpenAIRE

    Rakhshan, Ali; Ray, Evan; Pishro-Nik, Hossein

    2014-01-01

    Adapting the functioning of the collision warning systems to the specific drivers' characteristics is of great benefit to drivers. For example, by customizing collision warning algorithms we can minimize false alarms, thereby reducing injuries and deaths in highway traffic accidents. In order to take the behaviors of individual drivers into account, the system needs to have a Real-Time estimation of the distribution of brake response times for an individual driver. In this paper, we propose a...

  1. Operation of a 1P28 photomultiplier with subnanosecond response time

    International Nuclear Information System (INIS)

    The parameters governing the time response of an RCA 1P28 photomultiplier are investigated, and special circuitry for optimum time response is described. Photomultiplier performance is extensively evaluated with respect to application in flash photolysis and pulse radiolysis. The output signal rise time achieved is 360 psec for a light impulse and 540 psec for a step function over a linear range extending to an anode current of 8 mA

  2. Impact of insufficient energy content in the design time history on the structure response

    International Nuclear Information System (INIS)

    In the design of nuclear power plants, it is often desirable to use the time history method in the soil-structure interaction analysis to determine the plant floor response to seismic loads. Because many design criteria are specified in terms of design response spectra, the artificial time history needs to be generated under the requirement that the response spectra of the artificial history should envelop the given design response spectra. However, recent studies indicate that the artificial time history used in the plant design may have insufficient energy in the frequency range of interest, even though the response spectra of the design time history closely envelop the design response spectra. Therefore, the proposed changes in the NRC Standard Review Plan requires that when a single time history is used in the seismic design, it must satisfy requirements for both response spectra enveloping and matching a power spectra density (PSD) function in the frequency range of interest. The use of multiple artificial time histories (at least five time histories) in the plant design is also suggested in the new Standard Review Plan. This paper presents an investigation of the effects of the insufficient energy content in the design time history on the response of the soil-structure system. Numerical studies were carried out. Both the real earthquake records and the artificial time histories were used as the input motions in a simple lumped-mass soil-structure interaction model. The results obtained from this study provide a better understanding of the effects of the insufficient energy content in the design time history on the structural response. 5 refs., 10 figs., 1 tab

  3. Response Time Test for The Application of the Data Communication Network to Nuclear Power Plant

    International Nuclear Information System (INIS)

    This paper discusses the response time test for the application of the Data Communication Network (DCN) to Nuclear Power Plant (NPP). Conventional Instrumentation and Control (I and C) Systems using the analog technology in NPP have raised many problems regarding the lack of spare parts, maintenance burden, inaccuracy, etc.. In order to solve the problems, the Korean Next Generation Reactor (KNGR) I and C system has adopted the digital technology and new design features of using the data communication networks. It is essential to prove the response time requirements that arise from the introduction of digital I and C technology and data communication networks to nuclear power plant design. For the response time test, a high reliable data communication network structure has been developed to meet the requirements of redundancy, diversity, and segmentation. This paper presents the results of network load analysis and response time test for the KNGR DCN prototype. The test has been focused on the response time from the field components to the gateway because the response times from the gateway to the specific systems are similar to those of the existing design. It is verified that the response time requirements are met through the prototype test for KNGR I and C systems. (authors)

  4. Fertility in Gyr Cows (Bos indicus) with Fixed Time Artificial Insemination and Visual Estrus Detection Using a Classification Table

    OpenAIRE

    Lilido Nelson Ramírez-Iglesia; Rafael María Roman Bravo; Adelina Díaz de Ramirez; Torres, Leandro J.

    2014-01-01

    The aim of this research was to compare two artificial insemination protocols (AIP): hormonal synchronization with fixed time artificial insemination (SC-FTAI) and the use of a table based on visual observation of estrus signs (VO) in order to identify cows in natural or spontaneous estrus being assigned to AI (NSE-IA). Two groups were formed: in the first group 109 cows were assigned to SC-FTAI, in which a commercial protocol is used; the second one included 108 randomly chosen cows, which w...

  5. Multivariate Analyses and Classification of Inertial Sensor Data to Identify Aging Effects on the Timed-Up-and-Go Test

    OpenAIRE

    Vervoort, Danique; Vuillerme, Nicolas; Kosse, Nienke; Hortobágyi, Tibor; Lamoth, Claudine J. C.

    2016-01-01

    Many tests can crudely quantify age-related mobility decrease but instrumented versions of mobility tests could increase their specificity and sensitivity. The Timed-up-and-Go (TUG) test includes several elements that people use in daily life. The test has different transition phases: rise from a chair, walk, 180° turn, walk back, turn, and sit-down on a chair. For this reason the TUG is an often used test to evaluate in a standardized way possible decline in balance and walking ability due t...

  6. Real-time estimation of fault rupture extent using near-source versus far-source classification

    OpenAIRE

    Yamada, Masumi; Heaton, Thomas; Beck, James

    2007-01-01

    To estimate the fault dimension of an earthquake in real time, we present a methodology to classify seismic records into near-source or far-source records. Characteristics of ground motion, such as peak ground acceleration, have a strong correlation with the distance from a fault rupture for large earthquakes. This study analyzes peak ground motions and finds the function that best classifies near-source and far-source records based on these parameters. We perform (1) Fisher’s linear discrimi...

  7. Multiplex Real-Time PCR Assay for Detection and Classification of Klebsiella pneumoniae Carbapenemase Gene (blaKPC) Variants▿

    OpenAIRE

    Chen, Liang; Mediavilla, José R.; Endimiani, Andrea; Rosenthal, Marnie E.; Zhao, Yanan; Robert A Bonomo; Kreiswirth, Barry N.

    2011-01-01

    Carbapenem resistance mediated by plasmid-borne Klebsiella pneumoniae carbapenemases (KPC) is an emerging problem of significant clinical importance in Gram-negative bacteria. Multiple KPC gene variants (blaKPC) have been reported, with KPC-2 (blaKPC-2) and KPC-3 (blaKPC-3) associated with epidemic outbreaks in New York City and various international settings. Here, we describe the development of a multiplex real-time PCR assay using molecular beacons (MB-PCR) for rapid and accurate identific...

  8. Determination of the Response Time of Photoanisotropy in Azobenzene Side-Chain Polyesters

    DEFF Research Database (Denmark)

    Bublitz, D.; Fleck, B.; Wenke, L.; Ramanujam, P. S.; Ramanujam, P.S.; Hvilsted, Søren

    We present a method which allows the determination of the response time to polarized light of an azobenzene side-chain polyester. This method is based on the measurement of intensities in dependence on the delay time between a pump and a probe pulse. The described method does not need a very...... sophisticated time resolving measuring equipment. The time resolution is in the order 10 ps and is comparable with the laser pulse duration. The response time of the azobenzene side-chain polyester E1aP has determined to be about 40 ps. (C) 2000 Elsevier Science B.V. All rights reserved....

  9. Pattern classification of time plane features of ECG wave from cell-phone photography for machine aided cardiac disease diagnosis.

    Science.gov (United States)

    Mitra, Rupendra Nath; Pramanik, Sayak; Mitra, Sucharita; Chaudhuri, Bidyut B

    2014-01-01

    This article reports a robust technique for extracting time plane features of Electrocardiogram (ECG) from digital images of ECG paper strips. We concluded this article reporting performance evaluation of the system developed for machine aided cardiac disease detection. Mostly paper based ECG recordings are used in developing countries and digital photographs of different leads could easily be taken and sent with a mediocre cellular phone set. Apart from extracting the features, the proposed system detects cardiac axis deviation and diagnose if Left or Right Bundle Branch Blockage (LBBB or RBBB) is present while fed with the digital photographs of different leads of ECG strips. Preprocessing of the low-resolution images involves background grid line noise removal, adaptive image binarization by Sauvola's method and Bresenham's line joining algorithm to link the ECG signature, if broken. Pattern extraction mainly delineate the time plane features like P wave, QRS complex and T wave using water reservoir based pattern recognition techniques and Discrete Wavelet Transform (DWT). Cardiac axis deviation detection is done by checking the overall voltage levels of QRS complexes of lead I, II and III. Having the knowledge of cardiac axis completes the requirements to comment on the cardiac blockage like Left or Right Bundle Branch Blockage (LBBB or RBBB). Thus, the proposed algorithm is primarily developed for machine aided diagnosis of LBBB or RBBB from the digital photographs of ECG paper strips. PMID:25571067

  10. Determination of the Response Time of Photoanisotropy in Azobenzene Side-Chain Polyesters

    DEFF Research Database (Denmark)

    Bublitz, D.; Fleck, B.; Wenke, L.;

    2000-01-01

    sophisticated time resolving measuring equipment. The time resolution is in the order 10 ps and is comparable with the laser pulse duration. The response time of the azobenzene side-chain polyester E1aP has determined to be about 40 ps. (C) 2000 Elsevier Science B.V. All rights reserved....

  11. Multiple Feature Fusion Based on Co-Training Approach and Time Regularization for Place Classification in Wearable Video

    Directory of Open Access Journals (Sweden)

    Vladislavs Dovgalecs

    2013-01-01

    Full Text Available The analysis of video acquired with a wearable camera is a challenge that multimedia community is facing with the proliferation of such sensors in various applications. In this paper, we focus on the problem of automatic visual place recognition in a weakly constrained environment, targeting the indexing of video streams by topological place recognition. We propose to combine several machine learning approaches in a time regularized framework for image-based place recognition indoors. The framework combines the power of multiple visual cues and integrates the temporal continuity information of video. We extend it with computationally efficient semisupervised method leveraging unlabeled video sequences for an improved indexing performance. The proposed approach was applied on challenging video corpora. Experiments on a public and a real-world video sequence databases show the gain brought by the different stages of the method.

  12. Low Cost Em Signal Spectral Analysis with Two Element Time Modulated Array System by Multiple Signal Classification Algorithms

    Directory of Open Access Journals (Sweden)

    G. Balagurappa,

    2014-03-01

    Full Text Available Today homeland security is a big matter of concern. The present day wireless technology is available to anti-social elements, who are using this in several undesirable manners. By knowing the direction of the source of electromagnetic waves it becomes possible to locate such anti-social groups and take offensive action. In military applications also finding the direction of the signal source becomes very valuable information. The direction finding systems can achieve this goal. Conventional radio direction finding (RDF systems often use an array of two or more antennas and use either phase-comparison or amplitude-comparison of the received signals to determine direction of arrival information. In both of these techniques directional information is derived by processing array data at the receive signal frequency. In this project an alternative approach to direction finding using the concept of a time-switched array is proposed. The time-switched array system uses simple signal processing techniques to provide a directional main beam and pattern nulls at harmonic frequencies. To determine two dimensional angles is three elements, the system cost has been mostly minimised. we now consider the problem of using our low cost system to detect and estimate the direction of arrival of a desired signal in the presence of array antenna. The proposed scheme is cost effective technique in comparison with the existing schemes. MATLAB/GNU OCTAVE simulation tool will be used for simulation. The simulation results, applications, merits and demerits of proposed approach will be analyzed and will be documented.

  13. An accurate measurement of the Rosemount 1152 differential pressure cell response time

    International Nuclear Information System (INIS)

    The primary heat-transport (PHT) system of a CANDU reactor includes four quadrants of reactor coolant channels, each fed from its own inlet header through a large number of inlet feeders. As part of the safety shutdown system 1 (SDS1) and Reactor Regulating System (RRS) of CANDU reactors, differential-pressure (DP) cells are used to monitor the reactor coolant flows in each quadrant and to register changes with a prescribed response time. This paper describes an accurate in-situ measurement of the response time of two Rosemount 1152 DPA22PB DP cells, one from SDS1 and one from an RRS fully instrumented channel. The response time measurement was done using high-frequency pressure-measurement devises temporarily installed on the high- and low-pressure sides of the DP cells. The results suggest that the actual time constant of the Rosemount DP cell is much faster than indicated in the specification which is based on the traditional instrument-air-step-response measurement method. Furthermore, the actual time constant is much faster than that assumed in the safety analysis report. An examination of the instrument-air-step-response method indicates that is produces conservative estimates of time constants, especially for small time constants. If further work confirms this finding it suggests that the actual time constant may be increased considerably without exceeding the time constant assumed in the safety analysis. (author)

  14. Time Domain Simulation of Transient Responses of Very Large Floating Structures Under Unsteady External Loads

    Institute of Scientific and Technical Information of China (English)

    QIU Liu-chao; LIU Hua

    2005-01-01

    A time domain finite element method (FEM) for the analysis of transient elastic response of a very large floating structure (VLFS) subjected to arbitrary time-dependent external loads is presented. This method is developed directly in time domain and the hydrodynamic problem is formulated based on linear, inviscid and slightly compressible fluid theory and the structural response is analyzed on the thin plate assumption. The time domain finite element procedure herein is validated by comparing numerical results with available experimental data. Finally, the transient elastic response of a pontoon-type VLFS under the landing of an airplane is computed by the proposed time domain FEM. The time histories of the applied force and the position and velocity of an airplane during landing are modeled with data from a Boeing 747-400 jumbo jet.

  15. Optimized spatio-temporal descriptors for real-time fall detection: comparison of support vector machine and Adaboost-based classification

    Science.gov (United States)

    Charfi, Imen; Miteran, Johel; Dubois, Julien; Atri, Mohamed; Tourki, Rached

    2013-10-01

    We propose a supervised approach to detect falls in a home environment using an optimized descriptor adapted to real-time tasks. We introduce a realistic dataset of 222 videos, a new metric allowing evaluation of fall detection performance in a video stream, and an automatically optimized set of spatio-temporal descriptors which fed a supervised classifier. We build the initial spatio-temporal descriptor named STHF using several combinations of transformations of geometrical features (height and width of human body bounding box, the user's trajectory with her/his orientation, projection histograms, and moments of orders 0, 1, and 2). We study the combinations of usual transformations of the features (Fourier transform, wavelet transform, first and second derivatives), and we show experimentally that it is possible to achieve high performance using support vector machine and Adaboost classifiers. Automatic feature selection allows to show that the best tradeoff between classification performance and processing time is obtained by combining the original low-level features with their first derivative. Hence, we evaluate the robustness of the fall detection regarding location changes. We propose a realistic and pragmatic protocol that enables performance to be improved by updating the training in the current location with normal activities records.

  16. Heterogeneous Bank Lending Responses to Monetary Policy: New Evidence from a Real-time Identifiation

    OpenAIRE

    John C. Bluedorn; Bowdler, Christopher; Koch, Christoffer

    2009-01-01

    Heterogeneity in bank responses to monetary policy is consistent with an aggregate lending channel. However, estimates of bank responses are typically obtained using realized federal funds rate changes, which are endogenous to expected, macroeconomic fundamentals. As such, estimated heterogeneity can arise from expected fundamentals. Using an exogenous policy measure identified from narratives on FOMC intentions and real-time forecasts, we ?nd greater heterogeneity in responses. There is a mu...

  17. Response of Vibrio fischeri to repeated exposures over time in an Online Toxicity Monitor

    Science.gov (United States)

    Online Toxicity Monitors have been developed to provide continuous, time-relevant information regarding water quality. These systems measure a physiological or behavioral response of a sentinel organism to changes water quality. One such system, the Microlan Toxcontrol, is base...

  18. LEADING INDICATORS FOR REGIONAL COTTON RESPONSE: STRUCTURAL AND TIME SERIES MODELING RESULTS

    OpenAIRE

    Stavriotis, Paul A.; Houston, Jack E.; McIntosh, Christopher S.; Turner, Steven C.

    1998-01-01

    Resurging southeastern cotton production compels better cotton acreage forecasts for planning seed, chemical, and other input requirements. Structural models describe leading acreage response indicators, and forecasts are compared time-series models. Cotton price, loan rate, deficiency payments, lagged corn acreage, the PIK program, and previous cotton yield significantly influence response.

  19. LEADING INDICATORS OF REGIONAL COTTON ACREAGE RESPONSE: STRUCTURAL AND TIME SERIES MODELING RESULTS

    OpenAIRE

    Houston, Jack E.; McIntosh, Christopher S.; Stavriotis, Paul A.; Turner, Steven C.

    1999-01-01

    Resurgent cotton production compels better acreage forecasts for planning seed, chemical, and other input requirements. Structural models describe leading acreage response indicators, and forecasts are compared to time-series models. Cotton price, loan rate, deficiency payments, lagged corn acreage, the PIK program, and previous cotton yield significantly influence cotton acreage response.

  20. The Standard Time of Nature (STON) as the base for classification of the anisotropy phenomena of the Imbalance of Nature

    Science.gov (United States)

    Kontar, V. A.; Shlafman, L. M.

    2013-05-01

    Let the moment of emerge of some phenomenon of Nature equally zero, and the moment of death equally one. Then the duration of life of any natural phenomenon should be equal one unit of the Standard Time of Nature (STON). For visual clarity the horizontal axis will be the STON. The vertical axis of this system coordinates will be a parameter of the Life Activities (LAC) of this phenomenon. It is give the possibility to obtain the two-dimensional graph of the distribution of the parameter LAC by STON. For each natural phenomenon can be define several parameters LACx, and constructed the distribution LACx by STON. Any such distribution will be located on its own plane. All these distributions have a single mutual axis STON (like pages on the book). Let the numbers of the LACx parameters tend to infinity. So in the limit of all distributions LACx by STON will create the multidimensional body "LACx by STON". If the phenomenon of Nature is truly independent, so it means that the body LACx by STON must be independent. Any separate independent entity must have at the birth STON = 0, and at the death STON = 1. This means that the value of all LACx parameters of this phenomenon must be equally zero at the points STON = 0 and STON = 1. If (LAC)x ≠ 0 at the STON = 0, or STON = 1, so it means that a particular parameter (LAC)x is not a characteristic of the independent phenomenon or (LAC)x includes parameters from other phenomenon. By way of identifying the representative set of parameters (LAC)x it is possible create a multi-dimensional spatial characteristics of the separate phenomenon of Nature. It is possible estimate the extent of independency of this phenomenon of Nature by determining parameter SELF. If SELF = 0, then the phenomenon of Nature is really independent. If SELF ≠0, then this is not the independent phenomenon of Nature. Actually everything in Nature is interconnected and continuously. The separation of some anisotropy of Nature is necessary for the

  1. Implementation of Time and Frequency Response Analysis for Web-Based Laboratories

    Directory of Open Access Journals (Sweden)

    Teyana Sapula

    2011-04-01

    Full Text Available The University of Dar Es Salaam has developed the web-based laboratory for Time and Frequency Response Analysis. The purpose of this web-based laboratory is the utilization of real data from real experiments, in terms of instrumentation and experimental circuits, rather than simulations. The use of webbased laboratory came after realizing the difficulties imposed by the traditional laboratories. Web-based laboratories allow students and educators to interact with real laboratory equipment located anywhere in the world at anytime. This paper presents the implementation of web-based laboratory of single stage common emitter, resistor capacitor coupled amplifier using National Instruments Educational Laboratory Virtual Instrument Suite platform. Two components are deployed: time response analysis and frequency response analysis. The experiment allows students to carryout time and frequency analysis of the amplifier. The modular can be used to any microelectronic circuits to carry out any time response and frequency response analysis. Both the time response and frequency response analysis results of the amplifier are validated.

  2. Extensions and applications of the diffusion model for two-choice response times

    OpenAIRE

    Vandekerckhove, Joachim

    2009-01-01

    Joachim Vandekerckhove, Extensions and applications of the diffu sion model for two-choice response times. Dissertation submitted to obtain the degree of Doctor of Philosophy in Psychology, April 2009. Promoter: Prof. Dr. F. Tuerlinckx. Two-choice response time data (2CRT) is one of the most common formats o f empirical data in experimental psychology. Unfortunately, such data do not adhere to the requirements of standard statistical models (such as the general linear model). The main goa...

  3. On-line measurements of response time of temperature and pressure sensors in PWRs

    International Nuclear Information System (INIS)

    A review of modern techniques for in-situ response time testing of resistance temperature detectors (RTDs), and pressure, level and flow transmitters is presented. These techniques have been developed and validated for use in pressurized and boiling water reactors. The significance of the modern techniques is that they permit testing of installed sensors at process operating conditions and thereby provide the actual in-service response times of the sensors. (author)

  4. Transporter Classification Database (TCDB)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Transporter Classification Database details a comprehensive classification system for membrane transport proteins known as the Transporter Classification (TC)...

  5. On the Subsystem Formulation of Linear Response Time-Dependent DFT

    CERN Document Server

    Pavanello, Michele

    2013-01-01

    The subsystem formulation of linear response time-dependent DFT (TD-DFT) is analyzed in detail. Two equivalnt derivations are presented and naturally yield self consistent subsystem TD-DFT equations. One derivation largely follows the subsystem TD-DFT formalism of Neugebauer [J. Neugebauer, {\\it J. Chem. Phys.} {\\bf 126}, 134116 (2007)]. The other derivation yields Dyson type equations involving three types of subsystem response functions: coupled, uncoupled and Kohn-Sham. Analysis of the pole structure of the subsystem response functions shows that a single subsystem response function contains information about the electronic spectrum of the entire supersystem. Comparison of the subsystem and supersystem response functions shows that, while the correlated response is subsystem additive, the KS response is not. This partucularly puzzeling aspect of the theory is found to be an artifact stemming from the subjective nature of the density partitioning in subsystem DFT. This aspect is analyzed and compared to the...

  6. Optical response of extended systems from time-dependent Hartree-Fock and time-dependent density-functional theory

    Science.gov (United States)

    Bernasconi, Leonardo; Webster, Ross; Tomić, Stanko; Harrison, Nicholas M.

    2012-05-01

    We describe a unified formulation of time-dependent Hartree-Fock (TD-HF) and time-dependent density-functional theory (TD-DFT) for the accurate and efficient calculation of the optical response of infinite (periodic) systems. The method is formulated within the linear-response approximation, but it can easily be extended to include higher-order response contributions, and, in TD-DFT, it can treat with comparable computational efficiency purely local, semi-local or fully non-local approximations for the ground-state exchange-correlation (XC) functional and for the response TD-DFT XC kernel in the adiabatic approximation. At variance with existing methods for computing excitation energies based on the diagonalisation of suitable coupling matrices, or on the inversion of a dielectric matrix, our approach exploits an iterative procedure similar to a standard self-consistent field calculation. This results in a particularly efficient treatment of the coupling of excitations at different k points in the Brillouin zone. As a consequence, our method has the potential to describe completely from first principles the optically induced formation of bound particle-hole pairs in wide classes of materials. This point is illustrated by computing the optical gaps of a series of representative bulk semiconductors, (non-spin polarised) oxides and ionic insulators.

  7. Enhancing the humidity response time of polymer optical fiber Bragg grating by using laser micromachining.

    Science.gov (United States)

    Chen, Xianfeng; Zhang, Wei; Liu, Chen; Hong, Yanhua; Webb, David J

    2015-10-01

    The humidity sensors constructed from polymer optical fiber Bragg gratings (POFBG) respond to the water content change in the fiber induced by varying environmental condition. The water content change is a diffusion process. Therefore the response time of the POFBG sensor strongly depends on the geometry and size of the fiber. In this work we investigate the use of laser micromachining of D-shaped and slotted structures to improve the response time of polymer fiber grating based humidity sensors. A significant improvement in the response time has been achieved in laser micromachined D-shaped POFBG humidity sensors. The slotted geometry allows water rapid access to the core region but this does not of itself improve response time due to the slow expansion of the bulk of the cladding. We show that by straining the slotted sensor, the expansion component can be removed resulting in the response time being determined only by the more rapid, water induced change in core refractive index. In this way the response time is reduced by a factor of 2.5. PMID:26480109

  8. Response to gravity by Zea mays seedlings. I. Time course of the response

    Science.gov (United States)

    Bandurski, R. S.; Schulze, A.; Dayanandan, P.; Kaufman, P. B.

    1984-01-01

    Gravistimulation induces an asymmetric distribution of free indole-3-acetic acid (IAA) in the cortex-epidermis of the Zea mays L. cv 'Stowells Evergreen' mesocotyl within 15 minutes, the shortest time tested. IAA was measured by an isotope dilution method as the pentaflurobenzyl ester. The per cent IAA in the lower half of the mescotyl cortex was 56 to 57% at 15, 30, and 90 minutes after stimulus initiation. Curvature is detectable in the mescotyl within 3 minutes after beginning gravitropic stimulation. The rate of curvature of the mesocotyl increases during the first 60 minutes to maximum of about 30 degrees per hour. Thus, the growth asymmetry continues to increase for 45 minutes after hormone asymmetry is established. Free IAA occurs predominantly in the stele of the mesocotyl whereas esterified IAA is mainly in the mesocotyl cortex-epidermis. This compartmentation may permit determining in which tissue the hormone asymmetry arises. Current data suggest the asymmetry originated in the stele.

  9. Tissue Classification

    DEFF Research Database (Denmark)

    Van Leemput, Koen; Puonti, Oula

    2015-01-01

    Computational methods for automatically segmenting magnetic resonance images of the brain have seen tremendous advances in recent years. So-called tissue classification techniques, aimed at extracting the three main brain tissue classes (white matter, gray matter, and cerebrospinal fluid), are no...... software packages such as SPM, FSL, and FreeSurfer....

  10. Classifying Classification

    Science.gov (United States)

    Novakowski, Janice

    2009-01-01

    This article describes the experience of a group of first-grade teachers as they tackled the science process of classification, a targeted learning objective for the first grade. While the two-year process was not easy and required teachers to teach in a new, more investigation-oriented way, the benefits were great. The project helped teachers and…

  11. Time window-of-opportunity strategies for oil spill planning and response

    International Nuclear Information System (INIS)

    This paper presents an integrated scientific and engineering strategy to improve and bring planning and decision-making for marine oil spill response to a higher level of knowledge. The most efficient, environmentally preferred, and cost effective spill response is dependent on the following factors: chemistry of the spilled product, quantity, location, response time, environmental conditions, and effectiveness of available response technologies at various degrees of oil weathering. Time windows is a highly targeted process, in which the selection of response technologies will be more efficient, cost effective, technically correct, and environmentally sensitive and appropriate. The strategy integrates dynamic oil weathering data and performance effectiveness data for oil spill response technologies derived from laboratory, mesoscale, and experimental field studies. Performance data has been developed from a wide range of viscosities of different weathering stages of transported oils into a dynamic oil weathering database to identify and estimate time periods, called 'technology windows-of-opportunity.' In these windows, specific response methods, technologies, equipment, or products are more effective during clean-up operations for specific oils. The data bases represent the state of the art for response technologies and research in oil spill response. The strategy provides a standard foundation for rapid and cost effective oil spill response decision-making, and is intended for use by local, state, federal agencies, response planners, clean up organizations (responders), insurance companies, tanker owners, and transporters. It provides policy, planners and decision-makers with a scientifically based and documented 'tool' in oil spill response that has not been available before. (author)

  12. The effect of loading time on flexible pavement dynamic response: a finite element analysis

    Science.gov (United States)

    Yin, Hao; Solaimanian, Mansour; Kumar, Tanmay; Stoffels, Shelley

    2007-12-01

    Dynamic response of asphalt concrete (AC) pavements under moving load is a key component for accurate prediction of flexible pavement performance. The time and temperature dependency of AC materials calls for utilizing advanced material characterization and mechanistic theories, such as viscoelasticity and stress/strain analysis. In layered elastic analysis, as implemented in the new Mechanistic-Empirical Pavement Design Guide (MEPDG), the time dependency is accounted for by calculating the loading times at different AC layer depths. In this study, the time effect on pavement response was evaluated by means of the concept of “pseudo temperature.” With the pavement temperature measured from instrumented thermocouples, the time and temperature dependency of AC materials was integrated into one single factor, termed “effective temperature.” Via this effective temperature, pavement responses under a transient load were predicted through finite element analysis. In the finite element model, viscoelastic behavior of AC materials was characterized through relaxation moduli, while the layers with unbound granular material were assumed to be in an elastic mode. The analysis was conducted for two different AC mixtures in a simplified flexible pavement structure at two different seasons. Finite element analysis results reveal that the loading time has a more pronounced impact on pavement response in the summer for both asphalt types. The results indicate that for reasonable prediction of dynamic response in flexible pavements, the effect of the depth-dependent loading time on pavement temperature should be considered.

  13. Photomultiplier nonlinear response in time-domain laser-induced luminescence spectroscopy

    Directory of Open Access Journals (Sweden)

    Leandro José Bossy Schip

    2007-02-01

    Full Text Available A new procedure to find the limiting range of the photomultiplier linear response of a low-cost, digital oscilloscope-based time-resolved laser-induced luminescence spectrometer (TRLS, is presented. A systematic investigation on the instrument response function with different signal input terminations, and the relationship between the luminescence intensity reaching the photomultiplier and the measured decay time are described. These investigations establish that setting the maximum intensity of the luminescence signal below 0.3V guarantees, for signal input terminations equal or higher than 99.7 ohm, a linear photomultiplier response.

  14. Responsive Web Design – Evaluation of Techniques to Optimize Load Time

    OpenAIRE

    Nandorf, Joel

    2013-01-01

    Responsive Web Design has, in short time, become a common method to create websites that automatically adapt the layout to different screen sizes. However, critique has been raised about poor performance due to large page size and high number of requests to the web server. The aim of this study is to evaluate techniques to optimize the load time of a responsive website. This is done by creating a prototype in the form of a responsive website, which is used as a base for the optimization. Test...

  15. Dynamic Latent Classification Model

    DEFF Research Database (Denmark)

    Zhong, Shengtong; Martínez, Ana M.; Nielsen, Thomas Dyhre;

    possible. Motivated by this problem setting, we propose a generative model for dynamic classification in continuous domains. At each time point the model can be seen as combining a naive Bayes model with a mixture of factor analyzers (FA). The latent variables of the FA are used to capture the dynamics in...

  16. Analytical Call Center Model with Voice Response Unit and Wrap-Up Time

    Directory of Open Access Journals (Sweden)

    Petr Hampl

    2015-01-01

    Full Text Available The last twenty years of computer integration significantly changed the process of service in a call center service systems. Basic building modules of classical call centers – a switching system and a group of humans agents – was extended with other special modules such as skills-based routing module, automatic call distribution module, interactive voice response module and others to minimize the customer waiting time and wage costs. A calling customer of a modern call center is served in the first stage by the interactive voice response module without any human interaction. If the customer requirements are not satisfied in the first stage, the service continues to the second stage realized by the group of human agents. The service time of second stage – the average handle time – is divided into a conversation time and wrap-up time. During the conversation time, the agent answers customer questions and collects its requirements and during the wrap-up time (administrative time the agent completes the task without any customer interaction. The analytical model presented in this contribution is solved under the condition of statistical equilibrium and takes into account the interactive voice response module service time, the conversation time and the wrap-up time.

  17. MULTI-WAVELENGTH OBSERVATIONS OF SUPERNOVA 2011ei: TIME-DEPENDENT CLASSIFICATION OF TYPE IIb AND Ib SUPERNOVAE AND IMPLICATIONS FOR THEIR PROGENITORS

    Energy Technology Data Exchange (ETDEWEB)

    Milisavljevic, Dan; Margutti, Raffaella; Soderberg, Alicia M.; Chomiuk, Laura; Sanders, Nathan E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Pignata, Giuliano; Bufano, Filomena [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Fesen, Robert A.; Parrent, Jerod T. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Lab, Hanover, NH 03755 (United States); Parker, Stuart [Parkdale Observatory, 225 Warren Road, RDl Oxford, Canterbury 7495 (New Zealand); Mazzali, Paolo [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, D-85748 Garching (Germany); Pian, Elena [Kavli Institute for Theoretical Physics, Kohn Hall, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States); Pickering, Timothy; Buckley, David A. H.; Crawford, Steven M.; Gulbis, Amanda A. S.; Hettlage, Christian [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Hooper, Eric; Nordsieck, Kenneth H. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); O' Donoghue, Darragh, E-mail: dmilisav@cfa.harvard.edu [Southern African Large Telescope, P.O. Box 9, Observatory 7935, Cape Town (South Africa); and others

    2013-04-10

    We present X-ray, UV/optical, and radio observations of the stripped-envelope, core-collapse supernova (SN) 2011ei, one of the least luminous SNe IIb or Ib observed to date. Our observations begin with a discovery within {approx}1 day of explosion and span several months afterward. Early optical spectra exhibit broad, Type II-like hydrogen Balmer profiles that subside rapidly and are replaced by Type Ib-like He-rich features on a timescale of one week. High-cadence monitoring of this transition suggests absorption attributable to a high-velocity ({approx}> 12, 000 km s{sup -1}) H-rich shell, which is likely present in many Type Ib events. Radio observations imply a shock velocity of v Almost-Equal-To 0.13 c and a progenitor star average mass-loss rate of M-dot {approx}1.4 Multiplication-Sign 10{sup -5} M{sub sun} yr{sup -1} (assuming wind velocity v{sub w} = 10{sup 3} km s{sup -1}). This is consistent with independent constraints from deep X-ray observations with Swift-XRT and Chandra. Overall, the multi-wavelength properties of SN 2011ei are consistent with the explosion of a lower-mass (3-4 M{sub Sun }), compact (R{sub *} {approx}< 1 Multiplication-Sign 10{sup 11} cm), He-core star. The star retained a thin hydrogen envelope at the time of explosion, and was embedded in an inhomogeneous circumstellar wind suggestive of modest episodic mass loss. We conclude that SN 2011ei's rapid spectral metamorphosis is indicative of time-dependent classifications that bias estimates of the relative explosion rates for Type IIb and Ib objects, and that important information about a progenitor star's evolutionary state and mass loss immediately prior to SN explosion can be inferred from timely multi-wavelength observations.

  18. New method for evaluating effective recovery time and single photoelectron response in silicon photomultipliers

    Science.gov (United States)

    Grodzicka, Martyna; Szczęśniak, Tomasz; Moszyński, Marek; Szawłowski, Marek; Grodzicki, Krystian

    2015-05-01

    The linearity of a silicon photomultiplier (SiPM) response depends on the number of APD cells and its effective recovery time and it is related to the intensity and duration of the detected light pulses. The aim of this study was to determine the effective recovery time on the basis of the measured SiPM response to light pulses of different durations. A closer analysis of the SiPM response to the light pulses shorter than the effective recovery time of APD cells led to a method for the evaluation of the single photoelectron response of the devices where the single photoelectron peak cannot be clearly measured. This is necessary in the evaluation of the number of fired APD cells (or the number of photoelectrons) in measurements with light pulses of various durations. Measurements were done with SiPMs manufactured by two companies: Hamamatsu and SensL.

  19. New method for evaluating effective recovery time and single photoelectron response in silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Grodzicka, Martyna, E-mail: m.grodzicka@ncbj.gov.pl; Szczęśniak, Tomasz; Moszyński, Marek; Szawłowski, Marek; Grodzicki, Krystian

    2015-05-21

    The linearity of a silicon photomultiplier (SiPM) response depends on the number of APD cells and its effective recovery time and it is related to the intensity and duration of the detected light pulses. The aim of this study was to determine the effective recovery time on the basis of the measured SiPM response to light pulses of different durations. A closer analysis of the SiPM response to the light pulses shorter than the effective recovery time of APD cells led to a method for the evaluation of the single photoelectron response of the devices where the single photoelectron peak cannot be clearly measured. This is necessary in the evaluation of the number of fired APD cells (or the number of photoelectrons) in measurements with light pulses of various durations. Measurements were done with SiPMs manufactured by two companies: Hamamatsu and SensL.

  20. New method for evaluating effective recovery time and single photoelectron response in silicon photomultipliers

    International Nuclear Information System (INIS)

    The linearity of a silicon photomultiplier (SiPM) response depends on the number of APD cells and its effective recovery time and it is related to the intensity and duration of the detected light pulses. The aim of this study was to determine the effective recovery time on the basis of the measured SiPM response to light pulses of different durations. A closer analysis of the SiPM response to the light pulses shorter than the effective recovery time of APD cells led to a method for the evaluation of the single photoelectron response of the devices where the single photoelectron peak cannot be clearly measured. This is necessary in the evaluation of the number of fired APD cells (or the number of photoelectrons) in measurements with light pulses of various durations. Measurements were done with SiPMs manufactured by two companies: Hamamatsu and SensL

  1. 28 CFR 513.68 - Time limits for responses to Freedom of Information Act requests.

    Science.gov (United States)

    2010-07-01

    ... Information Act Requests for Information § 513.68 Time limits for responses to Freedom of Information Act... strives to comply with the time limits set forth in the Freedom of Information Act. ... Information Act requests. 513.68 Section 513.68 Judicial Administration BUREAU OF PRISONS, DEPARTMENT...

  2. Time delay of the voltage response to supercritical current pulses in superconducting aluminium

    International Nuclear Information System (INIS)

    Current pulses with amplitudes larger than the critical current Isub(c) are passed through superconducting aluminium strips. The time delay between the start of the pulse and the onset of the voltage response is measured as a function of current amplitude. The experimental results are compared with Tinkham's recent theoretical predictions based on the time dependent Ginzburg-Landau (TDGL) equation. (orig.)

  3. Contracts for Cross-organizational Workflows as Timed Dynamic Condition Response Graphs

    DEFF Research Database (Denmark)

    Hildebrandt, Thomas; Mukkamala, Raghava Rao; Slaats, Tijs; Zanitti, Francesco

    2013-01-01

    We conservatively extend the declarative Dynamic Condition Response (DCR) Graph process model, introduced in the PhD thesis of the second author, to allow for discrete time deadlines. We prove that safety and liveness properties can be verified by mapping finite timed DCR Graphs to finite state t...

  4. Anxiety and Sensory Over-Responsivity in Toddlers with Autism Spectrum Disorders: Bidirectional Effects across Time

    Science.gov (United States)

    Green, Shulamite A.; Ben-Sasson, Ayelet; Soto, Timothy W.; Carter, Alice S.

    2012-01-01

    This report focuses on the emergence of and bidirectional effects between anxiety and sensory over-responsivity (SOR) in toddlers with autism spectrum disorders (ASD). Participants were 149 toddlers with ASD and their mothers, assessed at 2 annual time points. A cross-lag analysis showed that anxiety symptoms increased over time while SOR remained…

  5. 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.

  6. Sea-floor classification using multibeam echo-sounding angular backscatter data: A real-time approach employing hybrid neural network architecture

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Kodagali, V.N.; Baracho, J.

    that tedious processing of raw backscatter values is unessential for efficient classification, hybrid ANN architecture has been attempted here due to its nonparametric approach. In this technical communication, successful employment of LVQ algorithm...

  7. A method to reduce response times in prehospital care: the motorcycle experience.

    Science.gov (United States)

    Lin, C S; Chang, H; Shyu, K G; Liu, C Y; Lin, C C; Hung, C R; Chen, P H

    1998-11-01

    This study compared the response times of a motorcycle and a standard ambulance in a congested urban emergency medical services (EMS) setting. The study was performed in Taipei, Taiwan, a densely populated urban area. A basic life support (BLS) motorcycle (without defibrillation capability) and an advanced life support (ALS) ambulance were based at three study hospitals and simultaneously dispatched when there was a perceived need for ALS ambulance transport. Over a 3-month period, prehospital personnel evaluated 307 medical and trauma emergencies. Time data were insufficient for analysis in 33 cases, leaving a study population of 274. Response times of the motorcycle and the ambulance were prospectively assessed and compared. During rush hours, the response times of the motorcycle and ambulance were 4.9+/-3.0 minutes and 6.3+/-3.4 minutes (P motorcycles to transport EMTs to the emergency scene significantly reduced response time compared with a standard ambulance in a congested urban setting. Large prospective studies are required to determine the impact on patient outcome of shorter EMS response times using motorcycles. EMS motorcycles appear feasible and deserve consideration to help expedite prehospital care in other systems in densely populated cities. PMID:9827757

  8. A study on HCI design strategy using emergent features and response time

    International Nuclear Information System (INIS)

    Existing design process of user interface has some weak point that there is no feedback information and no quantitative information between each sub process. If they're such information in design process, the design time cycle will be decreased and the contentment of HCI in the aspect of user will be more easily archived. In this study, new design process with feedback information and quantitative information was proposed using emergent features and user response time. The proposed methodology was put together with three main parts. First part is to calculate distinctiveness of a user interface or expanded user interface with consideration of emergent features. Second part is to expand a prototype user interface with design option for purpose of design requirement using directed structure graph (or nodal graph) theory. Last part is to convert non-realized value, distinctiveness, into realized value, response time, by response time database or response time correlation in the form of Hick-Hyman law equation. From the present validations, the usefulness of the proposed methodology was obtained by simple validation testing. It was found that emergent features should be improved for high reflection of real user interface. For the reliability of response time database, lots of end-user experiment is necessary. Expansion algorithm and representation technique of qualitative information should be somewhat improved for more efficient design process

  9. Modality-specific spectral dynamics in response to visual and tactile sequential shape information processing tasks: An MEG study using multivariate pattern classification analysis.

    Science.gov (United States)

    Gohel, Bakul; Lee, Peter; Jeong, Yong

    2016-08-01

    Brain regions that respond to more than one sensory modality are characterized as multisensory regions. Studies on the processing of shape or object information have revealed recruitment of the lateral occipital cortex, posterior parietal cortex, and other regions regardless of input sensory modalities. However, it remains unknown whether such regions show similar (modality-invariant) or different (modality-specific) neural oscillatory dynamics, as recorded using magnetoencephalography (MEG), in response to identical shape information processing tasks delivered to different sensory modalities. Modality-invariant or modality-specific neural oscillatory dynamics indirectly suggest modality-independent or modality-dependent participation of particular brain regions, respectively. Therefore, this study investigated the modality-specificity of neural oscillatory dynamics in the form of spectral power modulation patterns in response to visual and tactile sequential shape-processing tasks that are well-matched in terms of speed and content between the sensory modalities. Task-related changes in spectral power modulation and differences in spectral power modulation between sensory modalities were investigated at source-space (voxel) level, using a multivariate pattern classification (MVPC) approach. Additionally, whole analyses were extended from the voxel level to the independent-component level to take account of signal leakage effects caused by inverse solution. The modality-specific spectral dynamics in multisensory and higher-order brain regions, such as the lateral occipital cortex, posterior parietal cortex, inferior temporal cortex, and other brain regions, showed task-related modulation in response to both sensory modalities. This suggests modality-dependency of such brain regions on the input sensory modality for sequential shape-information processing. PMID:27134037

  10. Review of resistance temperature detector time response characteristics. Safety evaluation report

    International Nuclear Information System (INIS)

    A Resistance Temperature Detector (RTD) is used extensively for monitoring water temperatures in nuclear reactor plants. The RTD element does not respond instantaneously to changes in water temperature, but rather there is a time delay before the element senses the temperature change, and in nuclear reactors this delay must be factored into the computation of safety setpoints. For this reason it is necessary to have an accurate description of the RTD time response. This report is a review of the current state of the art of describing and measuring this time response

  11. Development of multi-layer thin film bolometer with fast time response and high sensitivity

    International Nuclear Information System (INIS)

    Impurity radiation loss is one of major cooling mechanisms in a fusion plasma. A multi-layer thin film bolometer with high sensitivity and fast time response has been developed for the measurement of radiation energy loss of a screw pinch plasma in TPE-2 device. The construction and test of the bolometer are described. High sensitivity of 2.5 mV/μ Joule and fast time response of 10 μsec with cooling time of 50 msec are obtained. (author)

  12. Assessing response in breast cancer with dynamic contrast-enhanced magnetic resonance imaging: are signal intensity-time curves adequate?

    Science.gov (United States)

    Woolf, David K; Padhani, Anwar R; Taylor, N Jane; Gogbashian, Andrew; Li, Sonia P; Beresford, Mark J; Ah-See, Mei-Lin; Stirling, James; Collins, David J; Makris, Andreas

    2014-09-01

    Quantitative DCE-MRI parameters including K(trans) (transfer constant min(-1)) can predict both response and outcome in breast cancer patients treated with neoadjuvant chemotherapy (NAC). Quantitative methods are time-consuming to calculate, requiring expensive software and interpretive expertise. For diagnostic purposes, signal intensity-time curves (SITCs) are used for tissue characterisation. In this study, we compare the ability of NAC-related changes in SITCs with K(trans) to predict response and outcomes. 73 women with primary breast cancer underwent DCE-MRI studies before and after two cycles of NAC. Patients received anthracycline and/or docetaxel-based chemotherapy. At completion of NAC, patients had local treatment with surgery & radiotherapy and further systemic treatments. SITCs for paired DCE-MRI studies were visually scored using a five-curve type classification schema encompassing wash-in and wash-out phases and correlated with K(trans) values and to the endpoints of pathological response, OS and DFS. 58 paired patients studies were evaluable. The median size by MRI measurement for 52 tumours was 38 mm (range 17-86 mm) at baseline and 26 mm (range 10-85 mm) after two cycles of NAC. Median baseline K(trans) (min(-1)) was 0.214 (range 0.085-0.469), and post-two cycles of NAC was 0.128 (range 0.013-0.603). SITC shapes were significantly related to K(trans) values both before (χ (2) = 43.3, P = 0.000) and after two cycles of NAC (χ (2) = 60.5, P = 0.000). Changes in curve shapes were significantly related to changes in K(trans) (χ (2) = 53.5, P = 0.000). Changes in curve shape were significantly correlated with clinical (P = 0.005) and pathological response (P = 0.005). Reductions in curve shape of ≥1 point were significant for overall improved survival using Kaplan-Meier analysis with a 5-year OS of 80.9 versus 68.6 % (P = 0.048). SITCs require no special software to generate and provide a useful method of assessing the

  13. Dynamic response time of a metal foam magneto-rheological damper

    International Nuclear Information System (INIS)

    Magneto-rheological (MR) dampers are a promising type of semi-active control device for various dynamic systems. Recently, low-cost MR dampers without any sealing structure have been required. Motivated by the desire to overcome the need for the costly dynamic seals of conventional MR dampers, a new type of metal foam MR damper is proposed in this study and the dynamic response performance is also investigated. The metal foam is firmly adhered to a working cylinder to store the unexcited MR fluids. In the action of a magnetic field, MR fluids will be extracted from the metal foam and fill up the shear gap to produce the MR effect. Three time parameters related to response time are introduced to further describe the dynamic response process. The results show that, due to the period required for extracting the MR fluids out from the metal foam, the time to produce the damper force of the metal foam MR damper is longer than for conventional fluid-filled MR dampers. The response time of the metal foam MR damper will change with different currents and shear rates. Given a constant shear rate, in a small range of currents (0–1.5 A), the response time decreases rapidly as the operating current increases; however, there is a slower change rate in larger ranges. To evaluate the effect of shear rate on response time, shear rates ranging from 2 to 10 s−1 are tested, and the results demonstrate that with increasing shear rates the response time decreases. (paper)

  14. Presentation and response timing accuracy in Adobe Flash and HTML5/JavaScript Web experiments.

    Science.gov (United States)

    Reimers, Stian; Stewart, Neil

    2015-06-01

    Web-based research is becoming ubiquitous in the behavioral sciences, facilitated by convenient, readily available participant pools and relatively straightforward ways of running experiments: most recently, through the development of the HTML5 standard. Although in most studies participants give untimed responses, there is a growing interest in being able to record response times online. Existing data on the accuracy and cross-machine variability of online timing measures are limited, and generally they have compared behavioral data gathered on the Web with similar data gathered in the lab. For this article, we took a more direct approach, examining two ways of running experiments online-Adobe Flash and HTML5 with CSS3 and JavaScript-across 19 different computer systems. We used specialist hardware to measure stimulus display durations and to generate precise response times to visual stimuli in order to assess measurement accuracy, examining effects of duration, browser, and system-to-system variability (such as across different Windows versions), as well as effects of processing power and graphics capability. We found that (a) Flash and JavaScript's presentation and response time measurement accuracy are similar; (b) within-system variability is generally small, even in low-powered machines under high load; (c) the variability of measured response times across systems is somewhat larger; and (d) browser type and system hardware appear to have relatively small effects on measured response times. Modeling of the effects of this technical variability suggests that for most within- and between-subjects experiments, Flash and JavaScript can both be used to accurately detect differences in response times across conditions. Concerns are, however, noted about using some correlational or longitudinal designs online. PMID:24903687

  15. Dynamic response time of a metal foam magneto-rheological damper

    Science.gov (United States)

    Yan, Yao X.; Hui, Liu X.; M, Yu; J, Fu; Dong, Liao H.

    2013-02-01

    Magneto-rheological (MR) dampers are a promising type of semi-active control device for various dynamic systems. Recently, low-cost MR dampers without any sealing structure have been required. Motivated by the desire to overcome the need for the costly dynamic seals of conventional MR dampers, a new type of metal foam MR damper is proposed in this study and the dynamic response performance is also investigated. The metal foam is firmly adhered to a working cylinder to store the unexcited MR fluids. In the action of a magnetic field, MR fluids will be extracted from the metal foam and fill up the shear gap to produce the MR effect. Three time parameters related to response time are introduced to further describe the dynamic response process. The results show that, due to the period required for extracting the MR fluids out from the metal foam, the time to produce the damper force of the metal foam MR damper is longer than for conventional fluid-filled MR dampers. The response time of the metal foam MR damper will change with different currents and shear rates. Given a constant shear rate, in a small range of currents (0-1.5 A), the response time decreases rapidly as the operating current increases; however, there is a slower change rate in larger ranges. To evaluate the effect of shear rate on response time, shear rates ranging from 2 to 10 s-1 are tested, and the results demonstrate that with increasing shear rates the response time decreases.

  16. Stability of adaptive cruise control systems taking account of vehicle response time and delay

    International Nuclear Information System (INIS)

    The region of string stability of a platoon of adaptive cruise control vehicles, taking into account the delay and response of the vehicle powertrain, is found. An upper bound on the explicit delay time as a function the first-order powertrain response time constant is determined. The system is characterized by a headway time constant, a sensitivity parameter, relative (to the vehicle immediately in front) velocity control, and delayed-velocity feedback or acceleration feedback. -- Highlights: ► I find the region of stability for a realistic adaptive cruise control system. ► Vehicle response time and explicit delay are included in the analysis. ► Delayed-feedback enlarges the parameter space that gives string stability.

  17. Information Gap Analysis: near real-time evaluation of disaster response

    Science.gov (United States)

    Girard, Trevor

    2014-05-01

    Disasters, such as major storm events or earthquakes, trigger an immediate response by the disaster management system of the nation in question. The quality of this response is a large factor in its ability to limit the impacts on the local population. Improving the quality of disaster response therefore reduces disaster impacts. Studying past disasters is a valuable exercise to understand what went wrong, identify measures which could have mitigated these issues, and make recommendations to improve future disaster planning and response. While such ex post evaluations can lead to improvements in the disaster management system, there are limitations. The main limitation that has influenced this research is that ex post evaluations do not have the ability to inform the disaster response being assessed for the obvious reason that they are carried out long after the response phase is over. The result is that lessons learned can only be applied to future disasters. In the field of humanitarian relief, this limitation has led to the development of real time evaluations. The key aspect of real time humanitarian evaluations is that they are completed while the operation is still underway. This results in findings being delivered at a time when they can still make a difference to the humanitarian response. Applying such an approach to the immediate disaster response phase requires an even shorter time-frame, as well as a shift in focus from international actors to the nation in question's government. As such, a pilot study was started and methodology developed, to analyze disaster response in near real-time. The analysis uses the information provided by the disaster management system within the first 0 - 5 days of the response. The data is collected from publicly available sources such as ReliefWeb and sorted under various categories which represent each aspect of disaster response. This process was carried out for 12 disasters. The quantity and timeliness of information

  18. Decision deadlines and uncertainty monitoring: the effect of time constraints on uncertainty and perceptual responses.

    Science.gov (United States)

    Zakrzewski, Alexandria C; Coutinho, Mariana V C; Boomer, Joseph; Church, Barbara A; Smith, J David

    2014-06-01

    The behavioral uncertainty response has grounded the study of animal metacognition and influenced the study of human psychophysics. However, the interpretation of this response is debated--especially whether it is a behavioral index of metacognition. The authors advanced this interpretation using the dissociative technique of response deadlines. Uncertainty responding, if it is higher level or metacognitive, should depend on a slower, more controlled decisional process and be more vulnerable to time constraints. Humans performed sparse-uncertain-dense or sparse-middle-dense discriminations in which, respectively, they could decline difficult trials or positively identify middle stimuli. Uncertainty responses were sharply and selectively reduced under a decision deadline, as compared to primary perceptual responses (i.e., "sparse," "middle," and "dense" responses). This dissociation suggests that the uncertainty response does reflect a higher-level, decisional response. It grants the uncertainty response a distinctive psychological role in its task and encourages an interpretation of this response as an elemental behavioral index of uncertainty that deserves continuing research. PMID:24072596

  19. Onset time and haemodynamic response after thiopental vs. propofol in the elderly: a randomized trial

    DEFF Research Database (Denmark)

    Sørensen, Martin Kryspin; Dolven, T L; Rasmussen, L S

    2011-01-01

    The induction dose of hypnotic agents should be reduced in the elderly, but it is not well studied whether thiopental or propofol should be preferred in this group of patients. The aim of this study was to compare onset time, hypnosis level and the haemodynamic response after thiopental vs....... propofol for induction of anaesthesia. Our primary hypothesis was that in the elderly, thiopental had a shorter onset time than propofol, defined as time to bispectral index (BIS)...

  20. Solving a Location, Allocation, and Capacity Planning Problem with Dynamic Demand and Response Time Service Level

    OpenAIRE

    2014-01-01

    Logistic systems with uncertain demand, travel time, and on-site processing time are studied here where sequential trip travel is allowed. The relationship between three levels of decisions: facility location, demand allocation, and resource capacity (number of service units), satisfying the response time requirement, is analysed. The problem is formulated as a stochastic mixed integer program. A simulation-based hybrid heuristic is developed to solve the dynamic problem under different respo...

  1. The mode of response and the Stroop effect: A reaction time analysis

    Directory of Open Access Journals (Sweden)

    Grega Repovš

    2004-08-01

    Full Text Available While the classical card versions of the Stroop colour-word tasks employ verbal mode of response (the participants have to read the stimuli or name their ink colour aloud, the single-item computerised versions of the task frequently rely on manual mode of response (the participants need to signal the meaning of the stimuli or its ink colour by pressing the appropriate key. An experiment was carried out to directly assess possible ERP and reaction times differences between a verbal and a manual response mode version of the task. The comparison of reaction time results obtained on 22 students of psychology performing both verbal and manual response mode version of the task show longer reaction times for the manual version as well as important differences between the patterns of reaction times of individual conditions obtained in each version of the task. The result demonstrated a qualitative difference between the two versions of the task, which can be attributed to a stronger influence of automatic word reading in the verbal response mode version. The differences shown warn against a direct comparison of results obtained with different response mode versions of the Stroop colour-word task.

  2. Electromagnet Response Time Tests on Primary CRDM of a Prototype Gen-IV SFR

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae-Han; Koo, Gyeong-Hoi [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    This paper identifies the electromagnetic response characteristics of the electromagnet of a primary control rod drive mechanism (CRDM) used for the reactor scram function. The test measures the electromagnet response time required to release an armature from a stator controlled by a loss of an electromagnetic force on an armature after shorting a power supply to an electromagnet coil. These tests are carried out while changing the electromagnet core material, an assist spring, and an armature holding current. The main factors influencing the test parameters on the response are found to be the armature holding current for holding the armature loads, and the material type of the electromagnet cores. The minimum response time is 0.13 seconds in the case of using SS410 material as an armature, while the S10C material as an armature has a response time of 0.21 seconds. Electromagnet response time characteristics from the test results will be evaluated by comparing the precise moving data of an electromagnet armature through the use of a high-speed camera and a potentiometer in the future.

  3. Electromagnet Response Time Tests on Primary CRDM of a Prototype Gen-IV SFR

    International Nuclear Information System (INIS)

    This paper identifies the electromagnetic response characteristics of the electromagnet of a primary control rod drive mechanism (CRDM) used for the reactor scram function. The test measures the electromagnet response time required to release an armature from a stator controlled by a loss of an electromagnetic force on an armature after shorting a power supply to an electromagnet coil. These tests are carried out while changing the electromagnet core material, an assist spring, and an armature holding current. The main factors influencing the test parameters on the response are found to be the armature holding current for holding the armature loads, and the material type of the electromagnet cores. The minimum response time is 0.13 seconds in the case of using SS410 material as an armature, while the S10C material as an armature has a response time of 0.21 seconds. Electromagnet response time characteristics from the test results will be evaluated by comparing the precise moving data of an electromagnet armature through the use of a high-speed camera and a potentiometer in the future

  4. Solving a Location, Allocation, and Capacity Planning Problem with Dynamic Demand and Response Time Service Level

    Directory of Open Access Journals (Sweden)

    Carrie Ka Yuk Lin

    2014-01-01

    Full Text Available Logistic systems with uncertain demand, travel time, and on-site processing time are studied here where sequential trip travel is allowed. The relationship between three levels of decisions: facility location, demand allocation, and resource capacity (number of service units, satisfying the response time requirement, is analysed. The problem is formulated as a stochastic mixed integer program. A simulation-based hybrid heuristic is developed to solve the dynamic problem under different response time service level. An initial solution is obtained from solving static location-allocation models, followed by iterative improvement of the three levels of decisions by ejection, reinsertion procedure with memory of feasible and infeasible service regions. Results indicate that a higher response time service level could be achieved by allocating a given resource under an appropriate decentralized policy. Given a response time requirement, the general trend is that the minimum total capacity initially decreases with more facilities. During this stage, variability in travel time has more impact on capacity than variability in demand arrivals. Thereafter, the total capacity remains stable and then gradually increases. When service level requirement is high, the dynamic dispatch based on first-come-first-serve rule requires smaller capacity than the one by nearest-neighbour rule.

  5. Spatial Attention and Temporal Expectation Under Timed Uncertainty Predictably Modulate Neuronal Responses in Monkey V1.

    Science.gov (United States)

    Sharma, Jitendra; Sugihara, Hiroki; Katz, Yarden; Schummers, James; Tenenbaum, Joshua; Sur, Mriganka

    2015-09-01

    The brain uses attention and expectation as flexible devices for optimizing behavioral responses associated with expected but unpredictably timed events. The neural bases of attention and expectation are thought to engage higher cognitive loci; however, their influence at the level of primary visual cortex (V1) remains unknown. Here, we asked whether single-neuron responses in monkey V1 were influenced by an attention task of unpredictable duration. Monkeys covertly attended to a spot that remained unchanged for a fixed period and then abruptly disappeared at variable times, prompting a lever release for reward. We show that monkeys responded progressively faster and performed better as the trial duration increased. Neural responses also followed monkey's task engagement-there was an early, but short duration, response facilitation, followed by a late but sustained increase during the time monkeys expected the attention spot to disappear. This late attentional modulation was significantly and negatively correlated with the reaction time and was well explained by a modified hazard function. Such bimodal, time-dependent changes were, however, absent in a task that did not require explicit attentional engagement. Thus, V1 neurons carry reliable signals of attention and temporal expectation that correlate with predictable influences on monkeys' behavioral responses. PMID:24836689

  6. Framework for estimating response time data to conduct a seismic human reliability analysis - its feasibility

    International Nuclear Information System (INIS)

    This is because the PSA has been used for several decades as the representative tool to evaluate the safety of NPPs. To this end, it is inevitable to evaluate human error probabilities (HEPs) in conducting important tasks being considered in the PSA framework (i.e., HFEs; human failure events), which are able to significantly affect the safety of NPPs. In addition, it should be emphasized that the provision of a realistic human performance data is an important precondition for calculating HEPs under a seismic condition. Unfortunately, it seems that HRA methods being currently used for calculating HEPs under a seismic event do not properly consider the performance variation of human operators. For this reason, in this paper, a framework to estimate response time data that are critical for calculating HEPs is suggested with respect to a seismic intensity. This paper suggested a systematic framework for estimating response time data that would be one of the most critical for calculating HEPs. Although extensive review of existing literatures is indispensable for identifying response times of human operators who have to conduct a series of tasks prescribed in procedures based on a couple of wrong indications, it is highly expected that response time data for seismic HRA can be properly secured through revisiting response time data collected from diverse situations without concerning a seismic event

  7. An evaluation of loop current step response time testing equipment for thermocouples

    International Nuclear Information System (INIS)

    In process instrumentation systems of such as nuclear plants, response time information is very important in most temperature transient measurements. Generally the response time of thermocouples is measured at a laboratory by using a plunge method. However, it is not easy to use the plunge testing method when a response time measurement of an installed thermocouple is required. A measurement system was developed to measure the response time of a thermocouple installed in a process by using the Loop Current Step Response(LCSR) testing method. This device heats a thermocouple by providing an electrical current, and then it measures the thermocouple output as the temperature of the thermocouple measurement junction returns to ambient temperature. The time constant of the thermocouple is determined from the transient curve of the thermocouple output indicating the temperature difference between the reference junction and measurement junction of the thermocouple. The device is designed to heat a middle point to reduce the temperature error caused by residual heat of thermocouple wire

  8. Justification of response time testing requirements for pressure and differential pressure sensors

    International Nuclear Information System (INIS)

    This paper reports on response time testing (RTT) requirements that were imposed on pressure, differential pressure sensors as a conservative approach to insure that assumptions in the plant safety analyses were met. The purpose of this project has been to identify the need for response time testing using the bases identified in IEEE Standard 338. A combination of plant data analyses, failure modes, and effects analyses (FMEAs) was performed. Eighteen currently qualified sensor models were utilized. The results of these analyses indicate that there are only two failure modes that affect response time, not sensor output concurrently. For these failure modes, appropriate plant actions and testing techniques were identified. Safety system RTT requirements were established by IEEE Standard 338-1975. Criteria for the Periodic Testing of Class IE Power, Protection Systems, presuming the need existed for this testing. This standard established guidelines for periodic testing to verify that loop response times of installed nuclear safety-related equipment were within the limits presumed by the design basis plant transient, accident analyses. The requirements covered all passive, active components in an instrument loop, including sensors. Individual components could be tested either in groups or separately to determine the overall loop response time

  9. Environmental hazards from natural hydrocarbons seepage: Integrated classification of risk from sediment chemistry, bioavailability and biomarkers responses in sentinel species

    International Nuclear Information System (INIS)

    Potential effects of natural emissions of hydrocarbons in the marine environment have been poorly investigated. In this study, a multidisciplinary weight of evidence (WOE) study was carried out on a shallow seepage, integrating sediment chemistry with bioavailability and onset of subcellular responses (biomarkers) in caged eels and mussels. Results from different lines of evidence (LOEs) were elaborated within a quantitative WOE model which, based on logical flowcharts, provide synthetic indices of hazard for each LOE, before their integration in a quantitative risk assessment. Evaluations of different LOEs were not always in accordance and their overall elaboration summarized as Moderate the risk in the seepage area. This study provided first evidence of biological effects in organisms exposed to natural hydrocarbon emissions, confirming the limit of chemical characterization as stand-alone criteria for environmental quality assessment and the utility of multidisciplinary investigations to determine the good environmental status as required by Environmental Directives. -- Highlights: • Hazards from natural seepage were evaluated through a multidisciplinary WOE study. • Caged eels and mussels were chosen as bioindicator organisms. • Evaluations obtained from various LOEs were not always in accordance. • Biological effects of natural hydrocarbons release were demonstrated. • WOE approach could discriminate different levels of hazard in low impacted conditions. -- A multidisciplinary WOE study in a shallow coastal seepage summarized a Moderate level of risk based on integration of sediment chemistry with biological effects in caged organisms

  10. PSG-Based Classification of Sleep Phases

    OpenAIRE

    Králík, M.

    2015-01-01

    This work is focused on classification of sleep phases using artificial neural network. The unconventional approach was used for calculation of classification features using polysomnographic data (PSG) of real patients. This approach allows to increase the time resolution of the analysis and, thus, to achieve more accurate results of classification.

  11. 32 CFR 2001.21 - Original classification.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Original classification. 2001.21 Section 2001.21... Markings § 2001.21 Original classification. (a) Primary markings. At the time of original classification, the following shall be indicated in a manner that is immediately apparent: (1)...

  12. Real-time regression schemes for integrating measurements with emergency response predictions

    International Nuclear Information System (INIS)

    If real-time radiological measurements are available, current computer technology provides an opportunity for improving hazard predictions during an emergency. The potential for substantially reducing prediction uncertainties by integrating real-time observations and predictions into an automated emergency response system exists. In developing such a system, great care must be taken to properly balance prediction-model sophistication, data quality and timing, response time, and a data/model integration scheme. The Atmospheric Release Advisory Capability (ARAC) of the U.S. Department of Energy has initiated a program to establish the feasibility of incorporating an automated, real-time method of correcting predictions using radiological measurements acquired during an emergency. This Predictor/Corrector (P/C) Model is predicated on (1) being able to obtain real-time measurements, (2) having a sophisticated prediction model capable of running many times during an emergency response and, (3) using an appropriately designed non-linear regression scheme. Model sophistication will be designed as a function of available response time. The current plan is to use ARAC's MATHEW/ADPIC model as the P/C predictor, but with the model restructured with multiple loops to provide differing degrees of sophistication, to be invoked as response time allows. We study different regression schemes potentially appropriate for the Predictor/Corrector Model. We use the ARAC Instantaneous Point Source (IPS) model to predict observations that were made at the Savannah River Plant for SF6 tracer releases during 1983. The number of IPS runs and the range of the initial parameter guesses that result in acceptable predictions are determined. Recommendations are made of the best candidates for implementation in the MATHEW/ADPIC model

  13. 14 CFR 1203.500 - Use of derivative classification.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Use of derivative classification. 1203.500... PROGRAM Derivative Classification § 1203.500 Use of derivative classification. The application of derivative classification markings is a responsibility of those who incorporate, paraphrase, restate,...

  14. On Continuous-Time Optimal Advertising Under S-Shaped Response

    OpenAIRE

    Fred M. Feinberg

    2001-01-01

    Continuous-time monopolistic models of advertising expenditure that rely on strict response concavity have been shown to prescribe eventual spending at a constant rate. However, analyses of discrete analogs have suggested that S-shaped response (convexity for low expenditure levels) may allow for the periodic optima encountered in actual practice. Casting the dynamic between advertising and sales in a common format (an autonomous, first-order relationship), the present paper explores extensio...

  15. Regional changes over time in initial virologic response rates to combination antiretroviral therapy across Europe

    DEFF Research Database (Denmark)

    Bannister, Wendy P; Kirk, Ole; Gatell, Jose M;

    2006-01-01

    BACKGROUND: Changes in virologic response to initial combination antiretroviral therapy (cART) over calendar time may indicate improvements in cART or emergence of primary resistance. Regional variations may identify differences in available antiretroviral drugs or patient management. METHODS......: Virologic response (viral load < 500 copies/mL) 6 to 12 months after starting cART was analyzed in antiretroviral-naive EuroSIDA patients. Analyses were stratified by region (south, central west, north, east) or time started cART (early, 1996-1997; mid, 1998-1999; late, 2000-1904). RESULTS: Virologic...... time (P < 0.001) on virologic response after adjustment for confounders. Stratified by period, regional differences were less evident (early cART, P = 0.967; mid cART, P = 0.291; late cART, P = 0.163). Stratified by region, temporal changes were observed (south, P = 0.061; central west, P < 0...

  16. Study on I/O response time bounds of networked storage systems

    Institute of Scientific and Technical Information of China (English)

    CUI Bao-jiang; LIU Jun; WANG Gang; LIU Jing

    2006-01-01

    In order to predict and improve the performance of networked storage systems,this paper explored the relationship between the system I/O response time and its performance factors by quantitative analytical method.Through analyzing data flow in networked RAID storage system,we established its analytical model utilizing closed queueing networks and studied the performance bounds of the system I/O response time.Experimental results show that the theoretical bounds are found to be in agreement with the actual performance bounds of the networked RAID storage system and reflect the dynamic trend of its actual performance.Furthermore,it concludes that the CPU processing power and cache hit rate of the central storage server are the key factors affecting the I/O response time as the concurrent jobs are lower,while the network bandwidth and cache hit rate of the central storage server become the key factors as the concurrent jobs go higher.

  17. Regular nonlinear response of the driven Duffing oscillator to chaotic time series

    International Nuclear Information System (INIS)

    Nonlinear response of the driven Duffing oscillator to periodic or quasi-periodic signals has been well studied. In this paper, we investigate the nonlinear response of the driven Duffing oscillator to non-periodic, more specifically, chaotic time series. Through numerical simulations, we find that the driven Duffing oscillator can also show regular nonlinear response to the chaotic time series with different degree of chaos as generated by the same chaotic series generating model, and there exists a relationship between the state of the driven Duffing oscillator and the chaoticity of the input signal of the driven Duffing oscillator. One real-world and two artificial chaotic time series are used to verify the new feature of Duffing oscillator. A potential application of the new feature of Duffing oscillator is also indicated. (general)

  18. Simulations of hybrid system varying solar radiation and microturbine response time

    Directory of Open Access Journals (Sweden)

    Yolanda Fernández Ribaya

    2015-07-01

    Full Text Available Hybrid power systems, such as combinations of renewable power sources with intermittent power production and non-renewable power sources, theoretically increase the reliability and thus integration of renewable sources in the electrical system. However, a recent increase in the number of hybrid installations has sparked interest in the effects of their connection to the grid, especially in remote areas. This paper analyses a photovoltaic-gas microturbine hybrid system dimensioned to be installed in La Paz (Mexico.The research presented in this paper studies and quantifies the effects on the total electric power produced, varying both the solar radiation and the gas microturbine response time. The gas microturbine and the photovoltaic panels are modelled using Matlab/Simulink software, obtaining a platform where different tests to simulate real conditions have been executed. They consist of diverse ramps of irradiance that replicate solar radiation variations, and different microturbine response times reproduced by the time constants of a first order transfer function that models the microturbine dynamic response. The results obtained show that when radiation varies quickly it does not produce significant differences in the power guarantee or the microturbine gas consumption, to any microturbine response time. However, these two parameters are highly variable with smooth radiance variations. The maximum total power variation decreases greatly as the radiation variation gets lower. In addition, by decreasing the microturbine response time, it is possible to appreciably increase the power guarantee although the maximum power variation and gas consumption increase. Only in cases of low radiation variation is there no appreciable difference in the maximum power variation obtained by the different turbine response times.

  19. Simulations of hybrid system varying solar radiation and microturbine response time

    International Nuclear Information System (INIS)

    Hybrid power systems, such as combinations of renewable power sources with intermittent power production and non-renewable power sources, theoretically increase the reliability and thus integration of renewable sources in the electrical system. However, a recent increase in the number of hybrid installations has sparked interest in the effects of their connection to the grid, especially in remote areas. This paper analyses a photovoltaic-gas microturbine hybrid system dimensioned to be installed in La Paz (Mexico).The research presented in this paper studies and quantifies the effects on the total electric power produced, varying both the solar radiation and the gas microturbine response time. The gas microturbine and the photovoltaic panels are modelled using Matlab/Simulink software, obtaining a platform where different tests to simulate real conditions have been executed. They consist of diverse ramps of irradiance that replicate solar radiation variations, and different microturbine response times reproduced by the time constants of a first order transfer function that models the microturbine dynamic response. The results obtained show that when radiation varies quickly it does not produce significant differences in the power guarantee or the microturbine gas consumption, to any microturbine response time. However, these two parameters are highly variable with smooth radiance variations. The maximum total power variation decreases greatly as the radiation variation gets lower. In addition, by decreasing the microturbine response time, it is possible to appreciably increase the power guarantee although the maximum power variation and gas consumption increase. Only in cases of low radiation variation is there no appreciable difference in the maximum power variation obtained by the different turbine response times

  20. Optimal Load Response to Time-of-Use Power Price for Demand Side Management in Denmark

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Bak-Jensen, Birgitte

    2010-01-01

    -of-use power price for demand side management in order to save the energy costs as much as possible. 3 typical different kinds of loads (industrial load, residential load and commercial load) in Denmark are chosen as study cases. The energy costs decrease up to 9.6% with optimal load response to time......-of-use power price for different loads. Simulation results show that the optimal load response to time-of-use power price for demand side management generates different load profiles and reduces the load peaks. This kind of load patterns may also have significant effects on the power system normal operation....

  1. Determination of the response time of pressure transducers using the direct method

    International Nuclear Information System (INIS)

    The available methods to determine the response time of nuclear safety related pressure transducers are discussed, with emphasis to the direct method. In order to perform the experiments, a Hydraulic Ramp Generator was built. The equipment produces ramp pressure transients simultaneously to a reference transducer and to the transducer under test. The time lag between the output of the two transducers, when they reach a predetermined setpoint, is measured as the time delay of the transducer under test. Some results using the direct method to determine the time delay of pressure transducers (1 E Class Conventional) are presented. (author). 18 refs, 35 figs, 12 tabs

  2. The contribution of pre-stimulus neural oscillatory activity to spontaneous response time variability.

    Science.gov (United States)

    Bompas, Aline; Sumner, Petroc; Muthumumaraswamy, Suresh D; Singh, Krish D; Gilchrist, Iain D

    2015-02-15

    Large variability between individual response times, even in identical conditions, is a ubiquitous property of animal behavior. However, the origins of this stochasticity and its relation to action decisions remain unclear. Here we focus on the state of the perception-action network in the pre-stimulus period and its influence on subsequent saccadic response time and choice in humans. We employ magnetoencephalography (MEG) and a correlational source reconstruction approach to identify the brain areas where pre-stimulus oscillatory activity predicted saccadic response time to visual targets. We find a relationship between future response time and pre-stimulus power, but not phase, in occipital (including V1), parietal, posterior cingulate and superior frontal cortices, consistently across alpha, beta and low gamma frequencies, each accounting for between 1 and 4% of the RT variance. Importantly, these correlations were not explained by deterministic sources of variance, such as experimental factors and trial history. Our results further suggest that occipital areas mainly reflect short-term (trial to trial) stochastic fluctuations, while the frontal contribution largely reflects longer-term effects such as fatigue or practice. Parietal areas reflect fluctuations at both time scales. We found no evidence of lateralization: these effects were indistinguishable in both hemispheres and for both saccade directions, and non-predictive of choice - a finding with fundamental consequences for models of action decision, where independent, not coupled, noise is normally assumed. PMID:25482267

  3. A New Thermostat for Real-Time Price Demand Response: Cost, Comfort and Energy Impacts of Discrete-Time Control without Deadband

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Stoustrup, Jakob; Agathoklis, Pan; Djilali, Ned

    2015-10-01

    This paper presents a residential thermostat design that enables accurate aggregate load control systems for electricity demand response. The thermostat features a control strategy that can be modeled as a linear time-invariant system for short- term demand response signals from the utility. This control design maintains the same comfort and demand response characteristics of existing real-time price- responsive thermostats but gives rise to linear time-invariant models of aggregate load control and demand response, which facilitates the design of highly accurate load-based regulation services for electricity interconnections.

  4. An Efficient Channel Model for OFDM and Time Domain Single Carrier Transmission Using Impulse Responses

    Directory of Open Access Journals (Sweden)

    Tariq Jamil Saifullah Khanzada

    2012-01-01

    Full Text Available The OFDM (Orthogonal Frequency Division Multiplexing is well-known, most utilized wideband communication technique of the current era. SCT (Single Carrier Transmission provides equivalent performance in time domain while decision equalizer is implemented in frequency domain. SCT annihilates the ICT (Inter Carrier Interference and the PAPR (Peak to Average Power Ratio which is inherent to OFDM and degrades its performance in time varying channels. An efficient channel model is presented in this contribution, to implement OFDM and SCT in time domain using impulse responses. Both OFDM and SCT models are derived dialectically to model the channel impulse responses. Our model enhances the performance of time domain SCT compared with OFDM and subsides the PAPR and ICI problems of OFDM. SCT is implemented at symbol level contained in blocks. Simulation results implementing Digital Radio Monadiale (DRM assert the performance gain of SCT over OFDM.

  5. Study on deterministic response time design for a class of nuclear Instrumentation and Control systems

    International Nuclear Information System (INIS)

    Highlights: ► An efficient design procedure for deterministic response time design of nuclear I and C system. ► We model the concurrent operations based on sequence diagrams and Petri nets. ► The model can achieve the deterministic behavior by using symbolic time representation. ► An illustrative example of the bistable processor logic is given. - Abstract: This study is concerned with a deterministic response time design for computer-based systems in the nuclear industry. In current approach, Petri nets are used to model the requirement of a system specified with sequence diagrams. Also, the linear logic is proposed to characterize the state of changes in the Petri net model accurately by using symbolic time representation for the purpose of acquiring deterministic behavior. An illustrative example of the bistable processor logic is provided to demonstrate the practicability of the proposed approach.

  6. Detecting variable responses in time-series using repeated measures ANOVA: Application to physiologic challenges.

    Science.gov (United States)

    Macey, Paul M; Schluter, Philip J; Macey, Katherine E; Harper, Ronald M

    2016-01-01

    We present an approach to analyzing physiologic timetrends recorded during a stimulus by comparing means at each time point using repeated measures analysis of variance (RMANOVA). The approach allows temporal patterns to be examined without an a priori model of expected timing or pattern of response. The approach was originally applied to signals recorded from functional magnetic resonance imaging (fMRI) volumes-of-interest (VOI) during a physiologic challenge, but we have used the same technique to analyze continuous recordings of other physiological signals such as heart rate, breathing rate, and pulse oximetry. For fMRI, the method serves as a complement to whole-brain voxel-based analyses, and is useful for detecting complex responses within pre-determined brain regions, or as a post-hoc analysis of regions of interest identified by whole-brain assessments. We illustrate an implementation of the technique in the statistical software packages R and SAS. VOI timetrends are extracted from conventionally preprocessed fMRI images. A timetrend of average signal intensity across the VOI during the scanning period is calculated for each subject. The values are scaled relative to baseline periods, and time points are binned. In SAS, the procedure PROC MIXED implements the RMANOVA in a single step. In R, we present one option for implementing RMANOVA with the mixed model function "lme". Model diagnostics, and predicted means and differences are best performed with additional libraries and commands in R; we present one example. The ensuing results allow determination of significant overall effects, and time-point specific within- and between-group responses relative to baseline. We illustrate the technique using fMRI data from two groups of subjects who underwent a respiratory challenge. RMANOVA allows insight into the timing of responses and response differences between groups, and so is suited to physiologic testing paradigms eliciting complex response patterns. PMID

  7. Combined Characterization of the Time Response of Impression Materials via Traditional and FTIR Measurements

    Directory of Open Access Journals (Sweden)

    Giacomo Derchi

    2015-05-01

    Full Text Available We investigated the temporal response of four dental impression materials, namely three siloxanes (Imprint 4, Flexitime, Aquasil and one polyether (Impregum. The null hypothesis was that the nominal working times are confirmed by instrumental laboratory tests. We also aimed to identify alternative techniques with strong physical-chemical background for the assessment of temporal response. Traditional characterization was carried out by shark fin test device and durometer at both ambient and body temperature. Additionally, Fourier-transform infrared spectroscopy was performed at room temperature. From shark fin height and Shore hardness versus time the working time and the setting time of the materials were evaluated, respectively. These were in reasonable agreement with the nominal values, except for Impregum, which showed longer working time. Spectroscopy confirmed the different character of the two types of materials, and provided for Imprint 4 and Aquasil an independent evaluation of both evolution times, consistent with the results of the other techniques. Shark fin test and durometer measurements showed deviations in setting time, low sensitivity to temperature for Flexitime, and longer working time at higher temperature for Impregum. Deviations of working time appear in operating conditions from what specified by the manufacturers. Fourier-transform infrared spectroscopy can provide insight in the correlation between material properties and their composition and structure.

  8. "The Backward-bending Commute times of Married Women with Household Responsibility"

    OpenAIRE

    Shinichiro Iwata; Keiko Tamada

    2008-01-01

    Though the existing literature provides evidence that married women choose short commutes because of low wages and household responsibilities, this theoretical paper shows that wives employed in highly paid positions also undertake short commutes and endogenously choose longer times for housework. In contrast, middle-class wives choose long commutes and undertake limited household chores. The results suggest that the commute times of wives follow a backward-bending pattern and there is a trad...

  9. An adaptive search for the response time variability problem☆

    OpenAIRE

    Salhi, S.; A García-Villoria

    2012-01-01

    The Response Time Variability Problem (RTVP) is an NP-hard combinatorial scheduling problem, which has recently been reported and formalised in the literature. This problem has a wide range of real-world applications in mixed-model assembly lines, multi-threaded computer systems, broadcast of commercial videotapes and others. The RTVP arises whenever products, clients or jobs need to be sequenced in such a way that the variability in the time between the points at which they receive the neces...

  10. Scenario-based real-time demand response considering wind power and price uncertainty

    OpenAIRE

    Wei, M.; Zhong, J.

    2015-01-01

    Real-time pricing can potentially lead to economic advantages for consumers in the environment of smart grid. Compared with flat rates, dynamic pricing allows consumers more engagement through measures of demand response (DR). This paper investigated the optimal hourly electricity consumption scheduling problem of a given consumer responding real-time price. The objective of the proposed model is to maximize the surplus of a consumer that is equipped with wind power and storage devices. Hourl...

  11. The Effects of Time on Task in Response Selection - An ERP Study of Mental Fatigue

    OpenAIRE

    Möckel, Tina; Beste, Christian; Wascher, Edmund

    2015-01-01

    Long lasting involvement in a cognitive task leads to mental fatigue. Substantial efforts have been undertaken to understand this phenomenon. However, it has been demonstrated that some changes with time on task are not only related to mental fatigue. The present study intends to clarify these effects of time on task unrelated to mental fatigue on response selection processes at the behavioural and electrophysiological level (using event-related potentials, ERPs). Participants had to perform ...

  12. Design of a test system for fast time response fibre optic oxygen sensors

    International Nuclear Information System (INIS)

    A test system has been developed that can be used to calibrate and determine the time response, linearity and temperature sensitivity of a fibre optic oxygen sensor. The simple system obviates the need for precision gas standards and the requirement to generate a true square wave step response, which is seldom achievable. The sensor is mounted in a small chamber containing air or a known fraction of oxygen. By means of a computer-controlled switch, the absolute pressure within the chamber can be changed rapidly to a new steady state value. The partial pressure of oxygen changes in direct proportion to the absolute pressure, and so the accuracy and linearity and response time of the PO2 calibration are limited only by those of the absolute pressure sensor. The temperature sensitivity of a commercial sensor and a means of correction are also described. (note)

  13. The time-dose-response relationship for elicitation of contact dermatitis in isoeugenol allergic individuals

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Johansen, Jeanne Duus; Bruze, M;

    2001-01-01

    The elicitation response in allergic contact dermatitis is dose dependent, but the time-concentration relationship for elicitation has not previously been described. In this study 27 isoeugenol-sensitive patients participated in serial dilution patch tests with isoeugenol and a double-blinded Rep...

  14. Circadian timed wakefulness at dawn opposes compensatory sleep responses after sleep deprivation in Octodon degus

    NARCIS (Netherlands)

    Kas, M J; Edgar, D M

    1999-01-01

    The circadian timing system in mammals is thought to promote wakefulness and oppose sleep drive that accumulates across the activity phase in diurnal and nocturnal species. Whether the circadian system actively opposes compensatory sleep responses in mammals with episodes of alertness consolidated a

  15. Decision-Tree Models of Categorization Response Times, Choice Proportions, and Typicality Judgments

    Science.gov (United States)

    Lafond, Daniel; Lacouture, Yves; Cohen, Andrew L.

    2009-01-01

    The authors present 3 decision-tree models of categorization adapted from T. Trabasso, H. Rollins, and E. Shaughnessy (1971) and use them to provide a quantitative account of categorization response times, choice proportions, and typicality judgments at the individual-participant level. In Experiment 1, the decision-tree models were fit to…

  16. What Are the Shapes of Response Time Distributions in Visual Search?

    Science.gov (United States)

    Palmer, Evan M.; Horowitz, Todd S.; Torralba, Antonio; Wolfe, Jeremy M.

    2011-01-01

    Many visual search experiments measure response time (RT) as their primary dependent variable. Analyses typically focus on mean (or median) RT. However, given enough data, the RT distribution can be a rich source of information. For this paper, we collected about 500 trials per cell per observer for both target-present and target-absent displays…

  17. Regional changes over time in initial virological response rates to combination antiretroviral therapy across Europe

    DEFF Research Database (Denmark)

    Bannister, W; Kirk, O; Gatell, J;

    2006-01-01

    BACKGROUND: Changes in virologic response to initial combination antiretroviral therapy (cART) over calendar time may indicate improvements in cART or emergence of primary resistance. Regional variations may identify differences in available antiretroviral drugs or patient management. METHODS: Vi...

  18. Three Essays on Teacher Education Programs and Test-Takers' Response Times on Test Items

    Science.gov (United States)

    Qian, Hong

    2013-01-01

    This dissertation includes three essays: one essay focuses on the effect of teacher preparation programs on teacher knowledge while the other two focus on test-takers' response times on test items. Essay One addresses the problem of how opportunities to learn in teacher preparation programs influence future elementary mathematics teachers'…

  19. The Necessity of Time-Reversal Symmetry Breaking for the Polar Kerr Effect in Linear Response

    CERN Document Server

    Cho, Weejee

    2015-01-01

    We show that the polar Kerr effect is absent if the nonlocal electromagnetic response function has the Onsager symmetry, which is characteristic of thermodynamic states that preserve time-reversal symmetry. A key element is an expression for the reflectivity tensor in terms of the causal Green's function.

  20. Regional changes over time in initial virologic response rates to combination antiretroviral therapy across Europe

    DEFF Research Database (Denmark)

    Bannister, Wendy P; Kirk, Ole; Gatell, Jose M;

    2006-01-01

    BACKGROUND: Changes in virologic response to initial combination antiretroviral therapy (cART) over calendar time may indicate improvements in cART or emergence of primary resistance. Regional variations may identify differences in available antiretroviral drugs or patient management. METHODS: Vi...

  1. Assessment of a Rotating Time Sampling Procedure: Implications for Interobserver Agreement and Response Measurement

    Science.gov (United States)

    Becraft, Jessica L.; Borrero, John C.; Davis, Barbara J.; Mendres-Smith, Amber E.

    2016-01-01

    The current study was designed to evaluate a rotating momentary time sampling (MTS) data collection system. A rotating MTS system has been used to measure activity preferences of preschoolers but not to collect data on responses that vary in duration and frequency (e.g., talking). We collected data on talking for 10 preschoolers using a 5-s MTS…

  2. Water Quality Response Times to Pasture Management Changes in Small and Large Watersheds

    Science.gov (United States)

    To interpret the effects of best management practices on water quality at a regional or large watershed scale likely response times at various scales must be known. Therefore, 4 small (<1 ha, 2.5 ac) watersheds, in rotational grazing studies at the North Appalachian Experimental Watershed (NAEW) nea...

  3. A national census of ambulance response times to emergency calls in Ireland

    OpenAIRE

    Breen, N; Woods, J.; Bury, G; Murphy, A.; Brazier, H

    2000-01-01

    Background—Equity of access to appropriate pre-hospital emergency care is a core principle underlying an effective ambulance service. Care must be provided within a timeframe in which it is likely to be effective. A national census of response times to emergency and urgent calls in statutory ambulance services in Ireland was undertaken to assess current service provision.

  4. On the Linear Relation between the Mean and the Standard Deviation of a Response Time Distribution

    Science.gov (United States)

    Wagenmakers, Eric-Jan; Brown, Scott

    2007-01-01

    Although it is generally accepted that the spread of a response time (RT) distribution increases with the mean, the precise nature of this relation remains relatively unexplored. The authors show that in several descriptive RT distributions, the standard deviation increases linearly with the mean. Results from a wide range of tasks from different…

  5. Norms of Filial Responsibility for Aging Parents across Time and Generations

    Science.gov (United States)

    Gans, Daphna; Silverstein, Merril

    2006-01-01

    This investigation examined the normative expectation that adult children should be responsible for the care of their aging parents, and how this norm changes over the adult life span, across several decades of historical time, in relation to generational position in families, and between successive generations. Analyses were performed using 4…

  6. Onset time and haemodynamic response after thiopental vs. propofol in the elderly: a randomized trial

    DEFF Research Database (Denmark)

    Sørensen, Martin Kryspin; Dolven, T L; Rasmussen, L S

    2011-01-01

    The induction dose of hypnotic agents should be reduced in the elderly, but it is not well studied whether thiopental or propofol should be preferred in this group of patients. The aim of this study was to compare onset time, hypnosis level and the haemodynamic response after thiopental vs...

  7. Mean Transit Time as a Predictor of Groundwater Discharge Response in the Upper Colorado River Basin

    Science.gov (United States)

    Solder, J. E.; Heilweil, V. M.; Stolp, B. J.; Susong, D.

    2015-12-01

    The Colorado River and its tributaries support 40 million municipal water users and 5.5 million acres of agriculture in the south western United States (U.S. Bureau of Reclamation, 2012). Recent estimates by Rumsey et al. (2015) suggest that a significant portion (about 50 percent) of surface water flow in the Upper Colorado River Basin (UCRB) is sustained by groundwater discharge to streams. Predicted climate variation (Cook et al., 2015) and increased water demand (U.S. Bureau of Reclamation, 2012) within the UCRB suggest future decreases in groundwater discharge, however transient groundwater responses are not well understood. In this study we calculate groundwater mean transit time (MTT) and transit time distribution (TTD) as predictors of the pattern and timing of groundwater response to hydraulic stress. Samples from nineteen large springs within the UCRB were analyzed for environmental tracers to determine MTT and TTD. The predictive value of the MTT is examined by a statistical analysis of MTT, historical spring discharge records, and the Palmer Hydrological Drought Index. MTTs of the 19 springs range from 10 to 15,000 years with a flow-weighted average of 1,650 years. The composite TTD of the 19 springs suggest that flowpaths representing 45 percent of their combined discharge have transit times greater than 100 years. However, spring discharge records indicate that flow responds to drought on much shorter (0.5 - 6 year) time scales, indicative of a hydraulic pressure response. Springs with shorter MTTs (Manga, 1999) has shown groundwater responds on shorter time scales than the MTT, but of interest the results presented here indicate that relatively stable and old springs with long MTTs (> 100) also show a hydraulic pressure response. While not fully representative of the UCRB, results from the 19 springs indicate that groundwater discharge responds to climate variation and water-demand imbalances over a relatively short time period of years.

  8. Classification of waste packages

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, H.P.; Sauer, M.; Rojahn, T. [Versuchsatomkraftwerk GmbH, Kahl am Main (Germany)

    2001-07-01

    A barrel gamma scanning unit has been in use at the VAK for the classification of radioactive waste materials since 1998. The unit provides the facility operator with the data required for classification of waste barrels. Once these data have been entered into the AVK data processing system, the radiological status of raw waste as well as pre-treated and processed waste can be tracked from the point of origin to the point at which the waste is delivered to a final storage. Since the barrel gamma scanning unit was commissioned in 1998, approximately 900 barrels have been measured and the relevant data required for classification collected and analyzed. Based on the positive results of experience in the use of the mobile barrel gamma scanning unit, the VAK now offers the classification of barrels as a service to external users. Depending upon waste quantity accumulation, this measurement unit offers facility operators a reliable and time-saving and cost-effective means of identifying and documenting the radioactivity inventory of barrels scheduled for final storage. (orig.)

  9. Kondo time scales for quantum dots: Response to pulsed bias potentials

    International Nuclear Information System (INIS)

    The response of a quantum dot in the Kondo regime to rectangular pulsed bias potentials of various strengths and durations is studied theoretically. It is found that the rise time is faster than the fall time, and also faster than time scales normally associated with the Kondo problem. For larger values of the pulsed bias, one can induce dramatic oscillations in the induced current with a frequency approximating the splitting between the Kondo peaks that would be present in steady state. The effect persists in the total charge transported per pulse, which should facilitate the experimental observation of the phenomenon. (c) 2000 The American Physical Society

  10. Cause of Death Affects Racial Classification on Death Certificates

    OpenAIRE

    Andrew Noymer; Penner, Andrew M.; Aliya Saperstein

    2011-01-01

    Recent research suggests racial classification is responsive to social stereotypes, but how this affects racial classification in national vital statistics is unknown. This study examines whether cause of death influences racial classification on death certificates. We analyze the racial classifications from a nationally representative sample of death certificates and subsequent interviews with the decedents' next of kin and find notable discrepancies between the two racial classifications by...

  11. Individual classification of ADHD children by right prefrontal hemodynamic responses during a go/no-go task as assessed by fNIRS

    Directory of Open Access Journals (Sweden)

    Yukifumi Monden

    2015-01-01

    Full Text Available While a growing body of neurocognitive research has explored the neural substrates associated with attention deficit hyperactive disorder (ADHD, an objective biomarker for diagnosis has not been established. The advent of functional near-infrared spectroscopy (fNIRS, which is a noninvasive and unrestrictive method of functional neuroimaging, raised the possibility of introducing functional neuroimaging diagnosis in young ADHD children. Previously, our fNIRS-based measurements successfully visualized the hypoactivation pattern in the right prefrontal cortex during a go/no-go task in ADHD children compared with typically developing control children at a group level. The current study aimed to explore a method of individual differentiation between ADHD and typically developing control children using multichannel fNIRS, emphasizing how spatial distribution and amplitude of hemodynamic response are associated with inhibition-related right prefrontal dysfunction. Thirty ADHD and thirty typically developing control children underwent a go/no-go task, and their cortical hemodynamics were assessed using fNIRS. We explored specific regions of interest (ROIs and cut-off amplitudes for cortical activation to distinguish ADHD children from control children. The ROI located on the border of inferior and middle frontal gyri yielded the most accurate discrimination. Furthermore, we adapted well-formed formulae for the constituent channels of the optimized ROI, leading to improved classification accuracy with an area under the curve value of 85% and with 90% sensitivity. Thus, the right prefrontal hypoactivation assessed by fNIRS would serve as a potentially effective biomarker for classifying ADHD children at the individual level.

  12. Generation of artificial time-histories, rich in all frequencies, from given response spectra

    International Nuclear Information System (INIS)

    In order to apply the time-history method of seismic analysis, it is often desirable to generate a suitable artificial time-history from a given response spectrum. The method described allows the generation of such a time-history that is also rich in all frequencies in the spectrum. This richness is achieved by choosing a large number of closely-spaced frequency points such that the adjacent frequencies have their half-power points overlap. The adjacent frequencies satisfy the condition that the frequency interval Δf near a given frequency f is such that (Δf)/f<2c/csub(c) where c is the damping of the system and csub(c) is the critical damping. In developing an artificial time-history, it is desirable to specify the envelope and duration of the record, very often in such a manner as to reproduce the envelope property of a specific earthquake record, and such an option is available in the method described. Examples are given of the development of typical artificial time-histories from earthquake design response spectra and from floor response spectra

  13. Time and Strain Response of Repeated Ageing Treatments on Recycled Al-Si-Cu Alloy

    Directory of Open Access Journals (Sweden)

    D.T. GUNDU

    2013-07-01

    Full Text Available The objective of this study was to investigate the time response of 3-stage artificial ageing treatments on strength properties of recycled Al-Si-Cu alloy with a view to obtaining useful empirical relationships for predicting required treatment cycles. True compressive stress, micro hardness and strain (% were evaluated in response to ageing time and repeated ageing. The results of compression and hardness tests showed that alloy hardness and compressive stress increased with ageing time, and that these properties also increased with repeated ageing. The results also showed that alloy strain (% reduced with ageing time and repeated ageing, indicating increasing strength or strain hardening of the alloy with repeated ageing. Using these results, empirical models of the form ϕn = ϕ0eαt, and ϕn = ϕ0eαN are established for predicting the required ageing time and/or number of ageing treatments to raise the strength (or hardness of an alloy to desired levels to meet service requirements. The strain response of the alloy is modelled as εn = ε0e−αt.

  14. Sampling frequency, response times and embedded signal filtration in fast, high efficiency liquid chromatography: A tutorial.

    Science.gov (United States)

    Wahab, M Farooq; Dasgupta, Purnendu K; Kadjo, Akinde F; Armstrong, Daniel W

    2016-02-11

    With increasingly efficient columns, eluite peaks are increasingly narrower. To take full advantage of this, choice of the detector response time and the data acquisition rate a.k.a. detector sampling frequency, have become increasingly important. In this work, we revisit the concept of data sampling from the theorem variously attributed to Whittaker, Nyquist, Kotelnikov, and Shannon. Focusing on time scales relevant to the current practice of high performance liquid chromatography (HPLC) and optical absorbance detection (the most commonly used method), even for very narrow simulated peaks Fourier transformation shows that theoretical minimum sampling frequency is still relatively low (digital filters. We show that the common wisdom of sampling 20 points per peak can be inadequate for high efficiency columns and that the sampling frequency and response choices do affect the peak shape. If the sampling frequency is too low or response time is too large, the observed peak shapes will not remain as narrow as they really are - this is especially true for high efficiency and high speed separations. It is shown that both sampling frequency and digital filtering affect the retention time, noise amplitude, peak shape and width in a complex fashion. We show how a square-wave driven light emitting diode source can reveal the nature of the embedded filter. We discuss time uncertainties related to the choice of sampling frequency. Finally, we suggest steps to obtain optimum results from a given system. PMID:26803000

  15. Real-time Kadanoff-Baym approach to nuclear response functions

    CERN Document Server

    Köhler, H S

    2016-01-01

    Linear density response functions are calculated for symmetric nuclear matter of normal density by time-evolving two-time Green's functions in real time. Of particular interest is the effect of correlations. The system is therefore initially time-evolved with a collision term calculated in a direct Born approximation as well as with full (RPA) ring-summation until fully correlated. An external time-dependent potential is then applied. The ensuing density fluctuations are recorded to calculate the density response. This method was previously used by Kwong and Bonitz for studying plasma oscillations in a correlated electron gas. The energy-weighted sum-rule for the response function is guaranteed by using conserving self-energy insertions as the method then generates the full vertex-functions. These can alternatively be calculated by solving a Bethe -Salpeter equation as done in some previous works. The (first order) mean field is derived from a momentum-dependent (non-local) interaction while $2^{nd}$ order se...

  16. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    International Nuclear Information System (INIS)

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year

  17. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    Science.gov (United States)

    Milnes, J. S.; Horsfield, C. J.; Conneely, T. M.; Howorth, J.

    2014-11-01

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  18. Classification in Australia.

    Science.gov (United States)

    McKinlay, John

    Despite some inroads by the Library of Congress Classification and short-lived experimentation with Universal Decimal Classification and Bliss Classification, Dewey Decimal Classification, with its ability in recent editions to be hospitable to local needs, remains the most widely used classification system in Australia. Although supplemented at…

  19. Classification in context

    DEFF Research Database (Denmark)

    Mai, Jens Erik

    2004-01-01

    This paper surveys classification research literature, discusses various classification theories, and shows that the focus has traditionally been on establishing a scientific foundation for classification research. This paper argues that a shift has taken place, and suggests that contemporary cla...... classification research focus on contextual information as the guide for the design and construction of classification schemes....

  20. Multi-borders classification

    OpenAIRE

    Mills, Peter

    2014-01-01

    The number of possible methods of generalizing binary classification to multi-class classification increases exponentially with the number of class labels. Often, the best method of doing so will be highly problem dependent. Here we present classification software in which the partitioning of multi-class classification problems into binary classification problems is specified using a recursive control language.

  1. Early Flood Detection for Rapid Humanitarian Response: Harnessing Near Real-Time Satellite and Twitter Signals

    Directory of Open Access Journals (Sweden)

    Brenden Jongman

    2015-10-01

    Full Text Available Humanitarian organizations have a crucial role in response and relief efforts after floods. The effectiveness of disaster response is contingent on accurate and timely information regarding the location, timing and impacts of the event. Here we show how two near-real-time data sources, satellite observations of water coverage and flood-related social media activity from Twitter, can be used to support rapid disaster response, using case-studies in the Philippines and Pakistan. For these countries we analyze information from disaster response organizations, the Global Flood Detection System (GFDS satellite flood signal, and flood-related Twitter activity analysis. The results demonstrate that these sources of near-real-time information can be used to gain a quicker understanding of the location, the timing, as well as the causes and impacts of floods. In terms of location, we produce daily impact maps based on both satellite information and social media, which can dynamically and rapidly outline the affected area during a disaster. In terms of timing, the results show that GFDS and/or Twitter signals flagging ongoing or upcoming flooding are regularly available one to several days before the event was reported to humanitarian organizations. In terms of event understanding, we show that both GFDS and social media can be used to detect and understand unexpected or controversial flood events, for example due to the sudden opening of hydropower dams or the breaching of flood protection. The performance of the GFDS and Twitter data for early detection and location mapping is mixed, depending on specific hydrological circumstances (GFDS and social media penetration (Twitter. Further research is needed to improve the interpretation of the GFDS signal in different situations, and to improve the pre-processing of social media data for operational use.

  2. Increasing temperature forcing reduces the Greenland Ice Sheet's response time scale

    Science.gov (United States)

    Applegate, Patrick J.; Parizek, Byron R.; Nicholas, Robert E.; Alley, Richard B.; Keller, Klaus

    2015-10-01

    Damages from sea level rise, as well as strategies to manage the associated risk, hinge critically on the time scale and eventual magnitude of sea level rise. Satellite observations and paleo-data suggest that the Greenland Ice Sheet (GIS) loses mass in response to increased temperatures, and may thus contribute substantially to sea level rise as anthropogenic climate change progresses. The time scale of GIS mass loss and sea level rise are deeply uncertain, and are often assumed to be constant. However, previous ice sheet modeling studies have shown that the time scale of GIS response likely decreases strongly with increasing temperature anomaly. Here, we map the relationship between temperature anomaly and the time scale of GIS response, by perturbing a calibrated, three-dimensional model of GIS behavior. Additional simulations with a profile, higher-order, ice sheet model yield time scales that are broadly consistent with those obtained using the three-dimensional model, and shed light on the feedbacks in the ice sheet system that cause the time scale shortening. Semi-empirical modeling studies that assume a constant time scale of sea level adjustment, and are calibrated to small preanthropogenic temperature and sea level changes, may underestimate future sea level rise. Our analysis suggests that the benefits of reducing greenhouse gas emissions, in terms of avoided sea level rise from the GIS, may be greatest if emissions reductions begin before large temperature increases have been realized. Reducing anthropogenic climate change may also allow more time for design and deployment of risk management strategies by slowing sea level contributions from the GIS.

  3. Analytical solution for beam with time-dependent boundary conditions versus response spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Gou, P.F.; Panahi, K.K. [GE Nuclear Energy, San Jose, CA (United States)

    2001-07-01

    This paper studies the responses of a uniform simple beam for which the supports are subjected to time-dependent conditions. Analytical solution in terms of series was presented for two cases: (1) Two supports of a simple beam are subjected to a harmonic motion, and (2) One of the two supports is stationary while the other is subjected to a harmonic motion. The results of the analytical solution were investigated and compared with the results of conventional response spectrum method using the beam finite element model. One of the applications of the results presented in this paper can be used to assess the adequacy and accuracy of the engineering approaches such as response spectra methods. It has been found that, when the excitation frequency equals the fundamental frequency of the beam, the results from response spectrum method are in good agreement with the exact calculation. The effects of initial conditions on the responses are also examined. It seems that the non-zero initial velocity has pronounced effects on the displacement time histories but it has no effect on the maximum accelerations. (author)

  4. An explicit time domain solution for ground stratum response to harmonic moving loan

    Institute of Scientific and Technical Information of China (English)

    Xuecheng Bian; Yunmin Chen

    2006-01-01

    Based on the thin 1ayer method originally proposed in frequency domain, an explicit time domain semi-analytical solution has been developed for simulating three-dimensional layered ground responses to harmonic moving loads. The Fourier-Laplace transforms were applied to derive the transformed solution that satisfied the boundary conditions of horizontal infinities. The eigenvalue decomposition was performed with respect to Laplace parameter to express the ground motion corresponding to the eigenmodes. The formulation for each eigenmode incorporating the moving load expression was transformed back into time domain analytically, and the global system responses were given by means of the general mode superposition method. The proposed explicit time domain solution is suitable for studying various types of moving load acting on or inside the ground. In this paper a moving harmonic load with rectangular distribution was adopted to demonstrate the ground response simulation. Two illustrative examples for moving load with speeds below or above the ground Rayleigh wave velocity were presented to test the computational accuracy and efficiency of the proposed approach. A parametric study was also performed to investigate the influences of soil properties on the ground responses.

  5. Larger Neural Responses Produce BOLD Signals That Begin Earlier in Time

    Directory of Open Access Journals (Sweden)

    Serena eThompson

    2014-06-01

    Full Text Available Functional MRI analyses commonly rely on the assumption that the temporal dynamics of hemodynamic response functions (HRFs are independent of the amplitude of the neural signals that give rise to them. The validity of this assumption is particularly important for techniques that use fMRI to resolve sub-second timing distinctions between responses, in order to make inferences about the ordering of neural processes. Whether or not the detailed shape of the HRF is independent of neural response amplitude remains an open question, however. We performed experiments in which we measured responses in primary visual cortex (V1 to large, contrast-reversing checkerboards at a range of contrast levels, which should produce varying amounts of neural activity. Ten subjects (ages 22-52 were studied in each of two experiments using 3 Tesla scanners. We used rapid, 250 msec, temporal sampling (repetition time, or TR and both short and long inter-stimulus interval (ISI stimulus presentations. We tested for a systematic relationship between the onset of the HRF and its amplitude across conditions, and found a strong negative correlation between the two measures when stimuli were separated in time (long- and medium-ISI experiments, but not the short-ISI experiment. Thus, stimuli that produce larger neural responses, as indexed by HRF amplitude, also produced HRFs with shorter onsets. The relationship between amplitude and latency was strongest in voxels with lowest mean-normalized variance (i.e., parenchymal voxels. The onset differences observed in the longer-ISI experiments are likely attributable to mechanisms of neurovascular coupling, since they are substantially larger than reported differences in the onset of action potentials in V1 as a function of response amplitude.

  6. Text Classification using Artificial Intelligence

    CERN Document Server

    Kamruzzaman, S M

    2010-01-01

    Text classification is the process of classifying documents into predefined categories based on their content. It is the automated assignment of natural language texts to predefined categories. Text classification is the primary requirement of text retrieval systems, which retrieve texts in response to a user query, and text understanding systems, which transform text in some way such as producing summaries, answering questions or extracting data. Existing supervised learning algorithms for classifying text need sufficient documents to learn accurately. This paper presents a new algorithm for text classification using artificial intelligence technique that requires fewer documents for training. Instead of using words, word relation i.e. association rules from these words is used to derive feature set from pre-classified text documents. The concept of na\\"ive Bayes classifier is then used on derived features and finally only a single concept of genetic algorithm has been added for final classification. A syste...

  7. Text Classification using Data Mining

    CERN Document Server

    Kamruzzaman, S M; Hasan, Ahmed Ryadh

    2010-01-01

    Text classification is the process of classifying documents into predefined categories based on their content. It is the automated assignment of natural language texts to predefined categories. Text classification is the primary requirement of text retrieval systems, which retrieve texts in response to a user query, and text understanding systems, which transform text in some way such as producing summaries, answering questions or extracting data. Existing supervised learning algorithms to automatically classify text need sufficient documents to learn accurately. This paper presents a new algorithm for text classification using data mining that requires fewer documents for training. Instead of using words, word relation i.e. association rules from these words is used to derive feature set from pre-classified text documents. The concept of Naive Bayes classifier is then used on derived features and finally only a single concept of Genetic Algorithm has been added for final classification. A system based on the...

  8. Time-of-use based electricity demand response for sustainable manufacturing systems

    International Nuclear Information System (INIS)

    As required by the Energy Policy Act of 2005, utility companies across the U.S. are offering TOU (time-of-use) based electricity demand response programs. The TOU rate gives consumers opportunities to manage their electricity bill by shifting use from on-peak periods to mid-peak and off-peak periods. Reducing the amount of electricity needed during the peak load times makes it possible for the power grid to meet consumers' needs without building more costly backup infrastructures and help reduce GHG (greenhouse gas) emissions. Previous research on the applications of TOU and other electricity demand response programs has been mainly focused on residential and commercial buildings while largely neglected industrial manufacturing systems. This paper proposes a systems approach for TOU based electricity demand response for sustainable manufacturing systems under the production target constraint. Key features of this approach include: (i) the electricity related costs including both consumption and demand are integrated into production system modeling; (ii) energy-efficient and demand-responsive production scheduling problems are formulated and the solution technique is provided; and (iii) the effects of various factors on the near-optimal scheduling solutions are examined. The research outcome is expected to enhance the energy efficiency, electricity demand responsiveness, and cost effectiveness of modern manufacturing systems. - Highlights: • We propose a TOU based demand response approach for manufacturing systems. • Both electricity consumption and demand are integrated into the system modeling. • Energy-efficient and demand-responsive production scheduling problems are formulated. • The meta-heuristic solution technique is provided. • The effects of various factors on the scheduling solutions are examined

  9. Wide dynamic range neutron flux monitor having fast time response for the Large Helical Device

    International Nuclear Information System (INIS)

    A fast time response, wide dynamic range neutron flux monitor has been developed toward the LHD deuterium operation by using leading-edge signal processing technologies providing maximum counting rate up to ∼5 × 109 counts/s. Because a maximum total neutron emission rate over 1 × 1016 n/s is predicted in neutral beam-heated LHD plasmas, fast response and wide dynamic range capabilities of the system are essential. Preliminary tests have demonstrated successful performance as a wide dynamic range monitor along the design

  10. On the best learning algorithm for web services response time prediction

    DEFF Research Database (Denmark)

    Madsen, Henrik; Albu, Razvan-Daniel; Popentiu-Vladicescu, Florin

    2013-01-01

    In this article we will examine the effect of different learning algorithms, while training the MLP (Multilayer Perceptron) with the intention of predicting web services response time. Web services do not necessitate a user interface. This may seem contradictory to most people's concept of what...... an application is. A Web service is better imagined as an application "segment," or better as a program enabler. Performance is an important quality aspect of Web services because of their distributed nature. Predicting the response of web services during their operation is very important....

  11. An analysis of thermal response factors and how to reduce their computational time requirement

    Science.gov (United States)

    Wiese, M. R.

    1982-01-01

    Te RESFAC2 version of the Thermal Response Factor Program (RESFAC) is the result of numerous modifications and additions to the original RESFAC. These modifications and additions have significantly reduced the program's computational time requirement. As a result of this work, the program is more efficient and its code is both readable and understandable. This report describes what a thermal response factor is; analyzes the original matrix algebra calculations and root finding techniques; presents a new root finding technique and streamlined matrix algebra; supplies ten validation cases and their results.

  12. CCM: A Text Classification Method by Clustering

    DEFF Research Database (Denmark)

    Nizamani, Sarwat; Memon, Nasrullah; Wiil, Uffe Kock;

    2011-01-01

    In this paper, a new Cluster based Classification Model (CCM) for suspicious email detection and other text classification tasks, is presented. Comparative experiments of the proposed model against traditional classification models and the boosting algorithm are also discussed. Experimental results...... show that the CCM outperforms traditional classification models as well as the boosting algorithm for the task of suspicious email detection on terrorism domain email dataset and topic categorization on the Reuters-21578 and 20 Newsgroups datasets. The overall finding is that applying a cluster based...... approach to text classification tasks simplifies the model and at the same time increases the accuracy....

  13. 28 CFR 524.76 - Appeals of CIM classification.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Appeals of CIM classification. 524.76..., CLASSIFICATION, AND TRANSFER CLASSIFICATION OF INMATES Central Inmate Monitoring (CIM) System § 524.76 Appeals of CIM classification. An inmate may at any time appeal (through the Administrative Remedy Program)...

  14. Glacier volume response time and its links to climate and topography based on a conceptual model of glacier hypsometry

    OpenAIRE

    Raper, S.C.B.; R. J. Braithwaite

    2009-01-01

    Glacier volume response time is a measure of the time taken for a glacier to adjust its geometry to a climate change. It has been previously proposed that the volume response time is given approximately by the ratio of glacier thickness to ablation at the glacier terminus. We propose a new conceptual model of glacier hypsometry (area-altitude relation) and derive the volume response time where climatic and topographic parameters are separated. The former is expressed by mass balance gradients...

  15. Can response time be trained with bilateral limb training in children with Down syndrome?

    Directory of Open Access Journals (Sweden)

    Pratiksha Tilak Rao

    2015-01-01

    Full Text Available Aims: Response time (RT, that is, the time taken to respond is known to be delayed in children with Down syndrome (DS. We performed a pilot study to evaluate whether bilateral limb training can be used to train RT, in children with DS. Settings and Design: 10 children with DS (5 males were recruited from a special school in a suburban region using convenience sampling. Subjects and Methods: Response time was measured using an indigenously developed RT Analyzer, before and after intervention, from right and left hand. Structured bilateral limb training was given for a period of 4 weeks, using low-cost, locally available materials, in community settings. Statistical Analysis Used: The Wilcoxon signed ranks test was used for statistical analysis. Results: Significant improvements in RT following 4 weeks of intervention were seen in the left hand (P = 0.006 but not in the right hand (P = 0.104. Conclusions: Response time can be trained in children with DS using 4 weeks of bilateral limb training activities using low-cost, locally available materials.

  16. Changes in the timing of responses following spells of high speed flying

    Directory of Open Access Journals (Sweden)

    W.T.V. Adiseshiah

    1955-07-01

    Full Text Available One of the important signs of fatigue in pilots is prolongation of the time taken to respond to signals for action. Since promptness in action is essential in high speed flying, it was of interest to see whether any changes occur in the timing of response of IAF pilots after routing flying sorties. This study was carried out on a group of IAF jet fighter pilots stationed at Palam, New Delhi during the Summer months of 1954. The pilots were tested immediately before and after their flying exercises by measuring their response times to three arrangements of stimuli presented in rapid succession, so as to determine the time required for an immediate response, a discrimination and a choice. Analysis of results showed that there was slight prolongation in the post-flight values This difference was most marked after 'hard' stories. Of the various alternative explanations considered in order to account for this difference, 'transient, fatigue appears to be most plausible.

  17. The calculation and experiment on response time in gas-fuelling on ITER

    International Nuclear Information System (INIS)

    Because the gas fuelling pipe in the large tokamak is longer than that in the middle tokamaks, the response time for gas fuelling through the pipe will take some time (several hundreds mini-second) that can not be neglected especially in the impurity injection. The calculation on response time is useful for the design of gas fuelling system and for the selection of the vacuum components such as valves, mass flow meter or mass flow controller. It is also useful for analysis on gas-fuelling procedure in normal tokamak plasma discharge or in NBI injection. We deduced a set formulas equations for response time calculation which will not need the complex code. The latest experiments on gas (Ne) fuelling is done with conditions: pipe length =17 m, gas source pressure =0.09 MPa. In the two sets of experiments: one is used MFC (mass flow controller) for controlling gas-fuelling and the other one is used 148J valve for controlling the gas-fuelling. The calculated results based on the present equations are consist with the experimental data very well. It is sure that the paper is useful for one engages the gas fuelling work related to gas transport transient. (authors)

  18. Response regime studies on standard detectors for decay time determination in phosphor thermometry

    Science.gov (United States)

    Knappe, C.; Abou Nada, F.; Lindén, J.; Richter, M.; Aldén, M.

    2013-09-01

    This work compares the extent of linear response regimes from standard time-resolving optical detectors for phosphor thermometry. Different types of Photomultipliers (ordinary and time-gated) as well as an Avalanche Photodiode are tested and compared using the phosphorescent time decay of CdWO4 that ranges from 10 μs down to a few ns within a temperature span of 290 to 580 K. Effects originating from incipient detector saturation, far from obvious to the operator's eye, are revealed as a change in evaluated phosphorescence decay time. Since the decay time of thermographic phosphors itself is used for temperature determination - systematic temperature errors up to several tens of Kelvins may be introduced by such detector saturation. A detector mapping procedure is suggested in order to identify linear response regions where the decay-to-temperature evaluation can be performed unbiased. Generation of such a library is highly recommended prior to any quantitative measurement attempt. Using this detector library, even signals collected in the partly saturated regime can be corrected to their unbiased value extending the usable detector operating range significantly. Further, the use of an external current-to-voltage amplifier proved useful for most applications in time-based phosphor thermometry helping to limit saturation effects whilst maintaining a reasonable bandwidth and signal outputs.

  19. Streamflow response of a small forested catchment on different time scales

    Directory of Open Access Journals (Sweden)

    A. Zabaleta

    2012-08-01

    Full Text Available The hydrological response of a catchment to rainfall on different time scales is result of a complex system involving a range of physical processes which may operate simultaneously and have different spatial and temporal influences. This paper presents the analysis of streamflow response of a small humid-temperate catchment (Aixola, 4.8 km2 in the Basque Country on different time scales and discusses the role of the controlling factors. Firstly, daily time series analysis was used to establish a hypothesis on the general functioning of the catchment through the relationship between precipitation and discharge on an annual and multi-annual scale (2003–2008. Second, rainfall-runoff relationships and relationships among several hydrological variables, including catchment antecedent conditions, were explored at the event scale (222 events to check and improve the hypothesis. Finally, the evolution of electrical conductivity (EC during some of the monitored storm events (28 events was examined to identify the time-origin of waters. Quick response of the catchment to almost all the rainfall events as well as a considerable regulation capacity was deduced from the correlation and spectral analyses. These results agree with runoff event scale data analysis; however the event analysis revealed the non-linearity of the system, as antecedent conditions play a significant role in this catchment. Further, analysis at the event scale made possible to clarify factors controlling (precipitation, precipitation intensity and initial discharge the different aspects of the runoff response (runoff coefficient and discharge increase for this catchment. Finally, the evolution of EC of the waters enabled the time origin (event or pre-event waters of the quickflow to be established; specifically, the conductivity showed that pre-event waters usually represent a high percentage of the total discharge during runoff peaks. The importance of soil waters in the

  20. Time-Lag in Responses of Birds to Atlantic Forest Fragmentation: Restoration Opportunity and Urgency.

    Science.gov (United States)

    Uezu, Alexandre; Metzger, Jean Paul

    2016-01-01

    There are few opportunities to evaluate the relative importance of landscape structure and dynamics upon biodiversity, especially in highly fragmented tropical landscapes. Conservation strategies and species risk evaluations often rely exclusively on current aspects of landscape structure, although such limited assumptions are known to be misleading when time-lag responses occur. By relating bird functional-group richness to forest patch size and isolation in ten-year intervals (1956, 1965, 1978, 1984, 1993 and 2003), we revealed that birds with different sensitivity to fragmentation display contrasting responses to landscape dynamics in the Brazilian Atlantic Forest. For non-sensitive groups, there was no time-lag in response: the recent degree of isolation best explains their variation in richness, which likely relates to these species' flexibility to adapt to changes in landscape structure. However, for sensitive bird groups, the 1978 patch area was the best explanatory variable, providing evidence for a 25-year time-lag in response to habitat reduction. Time-lag was more likely in landscapes that encompass large patches, which can support temporarily the presence of some sensitive species, even when habitat cover is relatively low. These landscapes potentially support the most threatened populations and should be priorities for restoration efforts to avoid further species loss. Although time-lags provide an opportunity to counteract the negative consequences of fragmentation, it also reinforces the urgency of restoration actions. Fragmented landscapes will be depleted of biodiversity if landscape structure is only maintained, and not improved. The urgency of restoration action may be even higher in landscapes where habitat loss and fragmentation history is older and where no large fragment remained to act temporarily as a refuge. PMID:26820548

  1. Real-time Kadanoff-Baym approach to nuclear response functions

    Science.gov (United States)

    Köhler, H. S.; Kwong, N. H.

    2016-03-01

    Linear density response functions are calculated for symmetric nuclear matter of normal density by time-evolving two-time Green's functions in real time. Of particular interest is the effect of correlations. The system is therefore initially time-evolved with a collision term calculated in a direct Born approximation until fully correlated. An external time-dependent potential is then applied. The ensuing density fluctuations are recorded to calculate the density response. This method was previously used by Kwong and Bonitz for studying plasma oscillations in a correlated electron gas. The energy-weighted sum-rule for the response function is guaranteed by using conserving self-energy insertions as the method then generates the full vertex-functions. These can alternatively be calculated by solving a Bethe -Salpeter equation as done in works by Bozek et al. The (first order) mean field is derived from a momentum-dependent (non-local) interaction while 2nd order self-energies are calculated using a particle-hole two-body effective (or residual) interaction given by a gaussian local potential. We show results of calculations of the response function S(ɷ,q0 ) for q0 = 0.2, 0.4 and 0.8fm -1. Comparison is made with the nucleons being un-correlated i.e. with only the first order mean field included. We discuss the relation of our work with the Landau quasi-particle theory as applied to nuclear systems by Babu and Brown and followers.

  2. Time-Lag in Responses of Birds to Atlantic Forest Fragmentation: Restoration Opportunity and Urgency

    Science.gov (United States)

    Uezu, Alexandre; Metzger, Jean Paul

    2016-01-01

    There are few opportunities to evaluate the relative importance of landscape structure and dynamics upon biodiversity, especially in highly fragmented tropical landscapes. Conservation strategies and species risk evaluations often rely exclusively on current aspects of landscape structure, although such limited assumptions are known to be misleading when time-lag responses occur. By relating bird functional-group richness to forest patch size and isolation in ten-year intervals (1956, 1965, 1978, 1984, 1993 and 2003), we revealed that birds with different sensitivity to fragmentation display contrasting responses to landscape dynamics in the Brazilian Atlantic Forest. For non-sensitive groups, there was no time-lag in response: the recent degree of isolation best explains their variation in richness, which likely relates to these species’ flexibility to adapt to changes in landscape structure. However, for sensitive bird groups, the 1978 patch area was the best explanatory variable, providing evidence for a 25-year time-lag in response to habitat reduction. Time-lag was more likely in landscapes that encompass large patches, which can support temporarily the presence of some sensitive species, even when habitat cover is relatively low. These landscapes potentially support the most threatened populations and should be priorities for restoration efforts to avoid further species loss. Although time-lags provide an opportunity to counteract the negative consequences of fragmentation, it also reinforces the urgency of restoration actions. Fragmented landscapes will be depleted of biodiversity if landscape structure is only maintained, and not improved. The urgency of restoration action may be even higher in landscapes where habitat loss and fragmentation history is older and where no large fragment remained to act temporarily as a refuge. PMID:26820548

  3. Optimizing classification in intelligence processing

    OpenAIRE

    Costica, Yinon

    2010-01-01

    Approved for public release; distribution is unlimited The intelligence making process, often described as the intelligence cycle, consists of phases. Congestion may be experienced in phases that require time consuming tasks such as translation, processing and analysis. To ameliorate the performance of those timeconsuming phases, a preliminary classification of intelligence items regarding their relevance and value to an intelligence request is performed. This classification is subject to ...

  4. Classification and knowledge

    Science.gov (United States)

    Kurtz, Michael J.

    1989-01-01

    Automated procedures to classify objects are discussed. The classification problem is reviewed, and the relation of epistemology and classification is considered. The classification of stellar spectra and of resolved images of galaxies is addressed.

  5. Hazard classification methodology

    International Nuclear Information System (INIS)

    This document outlines the hazard classification methodology used to determine the hazard classification of the NIF LTAB, OAB, and the support facilities on the basis of radionuclides and chemicals. The hazard classification determines the safety analysis requirements for a facility

  6. Remote Sensing Information Classification

    Science.gov (United States)

    Rickman, Douglas L.

    2008-01-01

    This viewgraph presentation reviews the classification of Remote Sensing data in relation to epidemiology. Classification is a way to reduce the dimensionality and precision to something a human can understand. Classification changes SCALAR data into NOMINAL data.

  7. Response time variability and response inhibition predict affective problems in adolescent girls, not in boys : the TRAILS study

    NARCIS (Netherlands)

    van Deurzen, Patricia A. M.; Buitelaar, Jan K.; Brunnekreef, J. Agnes; Ormel, Johan; Minderaa, Ruud B.; Hartman, Catharina A.; Huizink, Anja C.; Speckens, Anne E. M.; Oldehinkel, A. J.; Slaats-Willemse, Dorine I. E.

    2012-01-01

    The present study examines the relationship between neurocognitive functioning and affective problems through adolescence, in a cross-sectional and longitudinal perspective. Baseline response speed, response speed variability, response inhibition, attentional flexibility and working memory were asse

  8. Time-frequency analysis of railway bridge response in forced vibration

    Science.gov (United States)

    Cantero, Daniel; Ülker-Kaustell, Mahir; Karoumi, Raid

    2016-08-01

    This paper suggests the use of the Continuous Wavelet Transform in combination with the Modified Littlewood-Paley basis to analyse bridge responses exited by traversing trains. The analysis provides an energy distribution map in the time-frequency domain that offers a better resolution compared to previous published studies. This is demonstrated with recorded responses of the Skidträsk Bridge, a 36 m long composite bridge located in Sweden. It is shown to be particularly useful to understand the evolution of the energy content during a vehicle crossing event. With this information it is possible to distinguish the effect of several of the governing factors involved in the dynamic response including vehicle's speed and axle configuration as well as non-linear behaviour of the structure.

  9. The genomic response of Ishikawa cells to bisphenol A exposure is dose- and time-dependent

    International Nuclear Information System (INIS)

    A reliable in vitro model to determine the potential estrogenic activity of chemicals of interest is still unavailable. To further investigate the usefulness of a human-derived cell line, we determined the transcriptional changes induced by bisphenol A (BPA) in Ishikawa cells at various doses (1 nM, 100 nM, 10 μM, and 100 μM) and time points (8, 24 and 48 h) by comparing the response of approximately 38,500 human genes and ESTs between treatment groups and controls (vehicle-treated). By trend analysis, we determined that the expression of 2794 genes was modified by BPA in a dose- and time-dependent manner (p ≤ 0.0001). However, the majority of gene expression changes induced in Ishikawa cells were elicited by the highest doses of BPA evaluated (10-100 μM), while the genomic response of the cells exposed to low doses of BPA was essentially negligible. By comparing the Ishikawa cells' response to BPA vs.17α-ethynyl estradiol we determined that the change in the expression of 307 genes was identical in the direction of the change, although the magnitude of the change for some genes was different. Further, the response of Ishikawa cells to high doses of BPA shared similarities to the estrogenic response of the rat uterus, specifically, 362 genes were regulated in a similar manner in vivo as well as in vitro. Gene ontology analysis indicated that BPA results in changes to multiple molecular pathways affecting various biological processes particularly associated with cell organization and biogenesis, regulation of translation, cell proliferation, and intracellular transport; processes also affected by estrogen exposure in the uterus of the rat. These results indicate that Ishikawa cells are capable of generating a biologically relevant estrogenic response after exposure to chemicals with varied estrogenic activity, and offer an in vitro model to assess this mode of action.

  10. Ultralong time response of magnetic fluid based on fiber-optic evanescent field.

    Science.gov (United States)

    Du, Bobo; Yang, Dexing; Bai, Yang; Yuan, Yuan; Xu, Jian; Jiang, Yajun; Wang, Meirong

    2016-07-20

    The ultralong time (a few hours) response properties of magnetic fluid using etched optical fiber are visualized and investigated experimentally. The operating structure is made by injecting magnetic fluid into a capillary tube that contains etched single-mode fiber. An interesting extreme asymmetry is observed, in which the transmitted light intensity after the etched optical fiber cannot reach the final steady value when the external magnetic field is turned on (referred to as the falling process), while it can reach the stable state quickly once the magnetic field is turned off (referred to as the rising process). The relationship between the response times/loss rates of the transmitted light and the strength of the applied magnetic field is obtained. The physical mechanisms of two different processes are discussed qualitatively. PMID:27463909

  11. On timing response improvement of an NE213 scintillator attached to two PMTs

    International Nuclear Information System (INIS)

    A 5 cm diameter by 6 cm height NE213 scintillator attached to two XP2282 PHOTONIS photomultiplier tubes (PMTs) exposed to 241Americium–Berylium (Am–Be) neutron–gamma source has been used for timing response studies. The neutron–gamma discrimination (NGD) measurements based on a modified zero-crossing (ZC) method show that the discrimination quality, usually expressed in figure-of-merit (FoM) and peak-to-valley (P/V) values, has been improved. The timing response evaluated with Monte Carlo light transport code, PHOTRACK, also verifies this improvement. - Highlights: • An NE213 scintillator attached to two photomultiplier tubes (PMTs) has been proposed. • The neutron–gamma discrimination (NGD) quality factors have been obtained. • The results confirm that the NGD quality of the proposed assembly has been improved

  12. An executable software architecture model for response time and reliability assessment

    Directory of Open Access Journals (Sweden)

    Zahra Norouzi

    2014-09-01

    Full Text Available With the increasing use of the Unified Modeling Language (UML diagrams to describe the software’s architecture and the importance of evaluating nonfunctional requirements at the level of software architecture, creating an executable model from these diagrams is essential. On the other hand, the UML diagrams do not directly provide features to evaluate nonfunctional system requirements. Thus, these capabilities can be added to UML diagrams by applying efficiency and reliability stereotypes. Because the techniques used in the UML is able to deal with certain matters, we develop uncertain UML, stereotypes and tags. In this paper, the architecture of a software system is described by using use case diagram, sequence and deployment of unified modeling language diagrams with annotations fuzzy stereotypes related to response time and reliability. The proposed method for calculating the response time and reliability based on fuzzy rules are introduced, and the algorithm is implemented for an executable model based on colored fuzzy Petri net.

  13. Review of Real-time Electricity Markets for Integrating Distributed Energy Resources and Demand Response

    DEFF Research Database (Denmark)

    Wang, Qi; Zhang, Chunyu; Ding, Yi;

    2015-01-01

    The high penetration of both Distributed Energy Resources (DER) and Demand Response (DR) in modern power systems requires a sequence of advanced strategies and technologies for maintaining system reliability and flexibility. Real-time electricity markets (RTM) are the nondiscriminatory transaction...... and DR to participate in balancing market transactions, while handling their meteorological or intermittent characteristics, facilitating asset utilization, and stimulating their active responses. Consequently, RTMs are dedicated to maintaining the flexibility and reliability of power systems. This...... power flow, which clears energy prices every 5 minutes. Group II applies zonal prices, with the time resolution of 5-min. Group III is a general balancing market, which clears zonal prices intro-hourly. The various successful RTM experiences have been summarized and discussed, which provides a technical...

  14. A Hidden Markov Models Approach for Crop Classification: Linking Crop Phenology to Time Series of Multi-Sensor Remote Sensing Data

    OpenAIRE

    2015-01-01

    Vegetation monitoring and mapping based on multi-temporal imagery has recently received much attention due to the plethora of medium-high spatial resolution satellites and the improved classification accuracies attained compared to uni-temporal approaches. Efficient image processing strategies are needed to exploit the phenological information present in temporal image sequences and to limit data redundancy and computational complexity. Within this framework, we implement the theory of Hidden...

  15. Simple peak shift analysis of time-of-flight data with a slow instrumental response function.

    Science.gov (United States)

    Nishimura, Goro; Tamura, Mamoru

    2005-01-01

    Analysis of time-of-flight (TOF) data is sometimes limited by the instrumental response function, and optical parameters are extracted from the observed response curve by several mathematical methods, such as deconvolution. In contrast to this, we demonstrate that a method using shifts of the peak time of the response curve with different source-detector separations can yield the average path length of the light traveling in a tissue-like sample without deconvolution. In addition, combining the intensity information allows us to separate the scattering and absorption coefficients. This simple method is more robust in signal-to-noise ratio than the moment analysis, which also does not require the deconvolution procedure, because the peak position is not significantly dependent on the baseline fluctuation and the contamination of the scattering. The analysis is demonstrated by TOF measurements of an Intralipid solution at 800 nm, and is applied to the measurements at 1.29 microm, where the temporal response of photomultiplier tubes is not sufficiently good. PMID:15847597

  16. Impact of demand-response on the efficiency and prices in real-time electricity markets

    OpenAIRE

    Gast, Nicolas; Le Boudec, Jean-Yves; Tomozei, Dan-Cristian

    2014-01-01

    We study the effect of Demand-Response (DR) in dynamic real-time electricity markets. We use a two-stage market model that takes into account the dynamical aspects of generation, demand, and DR. We study the real-time market prices in two scenarios: in the former, consumers anticipate or delay their flexible loads in reaction to market prices; in the latter, the flexible loads are controlled by an independent aggregator. For both scenarios, we show that, when users are price-takers, any compe...

  17. Response times in M/M/s fork-join networks

    OpenAIRE

    Ko, Sung-Seok; Serfozo, Richard F.

    2004-01-01

    We study a fork-join processing network in which jobs arrive according to a Poisson process and each job splits into m tasks, which are simultaneously assigned to m nodes that operate like M/M/s queueing systems. When all of its tasks are finished, the job is completed. The main result is a closed-form formula for approximating the distribution of the network's response time (the time to complete a job) in equilibrium. We also present an analogous approximation for the ...

  18. Time course and dose response of alpha tocopherol on oxidative stress in haemodialysis patients

    Directory of Open Access Journals (Sweden)

    Coombes Jeff S

    2009-10-01

    Full Text Available Abstract Background Oxidative stress is associated with increased cardiovascular morbidity and mortality particularly in patients with end stage kidney disease. Although observational data from the general population has shown dietary antioxidant intake is associated with reduced cardiovascular morbidity and mortality, most clinical intervention trials have failed to support this relationship. This may be a consequence of not using an effective antioxidant dose and/or not investigating patients with elevated oxidative stress. The SPACE study, conducted in haemodialysis patients, reported that 800 IU/day of alpha tocopherol significantly reduced cardiovascular disease endpoints. A recent time course and dose response study conducted in hypercholesterolaemic patients that found 1600 IU/day of alpha tocopherol was an optimal dose. There is no such dose response data available for haemodialysis patients. Therefore the aim of this study is to investigate the effect of different doses of oral alpha tocopherol on oxidative stress in haemodialysis patients with elevated oxidative stress and the time taken to achieve this effect. Methods The study will consist of a time-course followed by a dose response study. In the time course study 20 haemodialysis patients with elevated oxidative stress will take either 1600 IU/day natural (RRR alpha tocopherol for 20 weeks or placebo. Blood will be collected every two weeks and analysed for a marker of oxidative stress (plasma F2-isoprostanes and alpha tocopherol. The optimum time period to significantly decrease plasma F2-isoprostanes will be determined from this study. In the dose response study 60 patients will be randomised to receive either placebo, 100, 200, 400, 800 or 1600 IU/day of natural (RRR alpha tocopherol for a time period determined from the time course study. Blood will be collected at baseline and every two weeks and analysed for plasma F2-isoprostanes and alpha tocopherol. It is hypothesised that

  19. An Extended Time Series Algorithm for Modal Identification from Nonstationary Ambient Response Data Only

    Directory of Open Access Journals (Sweden)

    Chang-Sheng Lin

    2014-01-01

    Full Text Available Modal Identification is considered from response data of structural systems under nonstationary ambient vibration. The conventional autoregressive moving average (ARMA algorithm is applicable to perform modal identification, however, only for stationary-process vibration. The ergodicity postulate which has been conventionally employed for stationary processes is no longer valid in the case of nonstationary analysis. The objective of this paper is therefore to develop modal-identification techniques based on the nonstationary time series for linear systems subjected to nonstationary ambient excitation. Nonstationary ARMA model with time-varying parameters is considered because of its capability of resolving general nonstationary problems. The parameters of moving averaging (MA model in the nonstationary time-series algorithm are treated as functions of time and may be represented by a linear combination of base functions and therefore can be used to solve the identification problem of time-varying parameters. Numerical simulations confirm the validity of the proposed modal-identification method from nonstationary ambient response data.

  20. Time-series analysis reveals genetic responses to intensive management of razorback sucker (Xyrauchen texanus)

    OpenAIRE

    Thomas E Dowling; Turner, Thomas F.; Carson, Evan W; Saltzgiver, Melody J; Adams, Deborah; Kesner, Brian; Paul C Marsh

    2013-01-01

    Time-series analysis is used widely in ecology to study complex phenomena and may have considerable potential to clarify relationships of genetic and demographic processes in natural and exploited populations. We explored the utility of this approach to evaluate population responses to management in razorback sucker, a long-lived and fecund, but declining freshwater fish species. A core population in Lake Mohave (Arizona-Nevada, USA) has experienced no natural recruitment for decades and is m...