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Sample records for atsofl2 act redundantly

  1. AtSOFL1 and AtSOFL2 act redundantly as positive modulators of the endogenous content of specific cytokinins in Arabidopsis.

    Science.gov (United States)

    Zhang, Jingyu; Vankova, Radomira; Malbeck, Jiri; Dobrev, Petre I; Xu, Yunyuan; Chong, Kang; Neff, Michael M

    2009-12-09

    Although cytokinins have been known for decades to play important roles in the regulation of plant growth and development, our knowledge of the regulatory mechanism of endogenous content of specific cytokinins remains limited. Here, we characterized two SOB five-like (SOFL) genes, AtSOFL1 and AtSOFL2, in Arabidopsis (Arabidopsis thaliana) and showed that they acted redundantly in regulating specific cytokinin levels. Analysis of the translational fusion AtSOFL1:AtSOFL1-GUS and AtSOFL2:AtSOFL2-GUS indicated that AtSOFL1 and AtSOFL2 exhibited similar expression patterns. Both proteins were predominantly expressed in the vascular tissues of developing leaves, flowers and siliques, but barely detectable in roots and stems. Overexpression of either AtSOFL1 or AtSOFL2 led to increased cytokinin content and obvious corresponding mutant phenotypes for both transgenic seedlings and adult plants. In addition, overexpression and site-directed mutagenesis experiments demonstrated that the SOFL domains are necessary for AtSOFL2's overexpression phenotypes. Silencing or disrupting either AtSOFL1 or AtSOFL2 caused no obvious developmental defects. Endogenous cytokinin analysis, however, revealed that compared to the wild type control, the SOFL1-RNAi62 sofl2-1 double mutant accumulated lower levels of trans-zeatin riboside monophosphate (tZRMP) and N(6)-(Delta(2)-isopentenyl)adenosine monophosphate (iPRMP), which are biosynthetic intermediates of bioactive cytokinins. The double mutant also displayed decreased response to exogenous cytokinin in both callus-formation and inhibition-of-hypocotyl-elongation assays. Taken together, our data suggest that in plants AtSOFL1 and AtSOFL2 work redundantly as positive modulators in the fine-tuning of specific cytokinin levels as well as responsiveness.

  2. AtSOFL1 and AtSOFL2 act redundantly as positive modulators of the endogenous content of specific cytokinins in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Jingyu Zhang

    Full Text Available BACKGROUND: Although cytokinins have been known for decades to play important roles in the regulation of plant growth and development, our knowledge of the regulatory mechanism of endogenous content of specific cytokinins remains limited. METHODOLOGY/PRINCIPAL FINDINGS: Here, we characterized two SOB five-like (SOFL genes, AtSOFL1 and AtSOFL2, in Arabidopsis (Arabidopsis thaliana and showed that they acted redundantly in regulating specific cytokinin levels. Analysis of the translational fusion AtSOFL1:AtSOFL1-GUS and AtSOFL2:AtSOFL2-GUS indicated that AtSOFL1 and AtSOFL2 exhibited similar expression patterns. Both proteins were predominantly expressed in the vascular tissues of developing leaves, flowers and siliques, but barely detectable in roots and stems. Overexpression of either AtSOFL1 or AtSOFL2 led to increased cytokinin content and obvious corresponding mutant phenotypes for both transgenic seedlings and adult plants. In addition, overexpression and site-directed mutagenesis experiments demonstrated that the SOFL domains are necessary for AtSOFL2's overexpression phenotypes. Silencing or disrupting either AtSOFL1 or AtSOFL2 caused no obvious developmental defects. Endogenous cytokinin analysis, however, revealed that compared to the wild type control, the SOFL1-RNAi62 sofl2-1 double mutant accumulated lower levels of trans-zeatin riboside monophosphate (tZRMP and N(6-(Delta(2-isopentenyladenosine monophosphate (iPRMP, which are biosynthetic intermediates of bioactive cytokinins. The double mutant also displayed decreased response to exogenous cytokinin in both callus-formation and inhibition-of-hypocotyl-elongation assays. CONCLUSIONS/SIGNIFICANCE: Taken together, our data suggest that in plants AtSOFL1 and AtSOFL2 work redundantly as positive modulators in the fine-tuning of specific cytokinin levels as well as responsiveness.

  3. Polycomb complexes act redundantly to repress genomic repeats and genes

    DEFF Research Database (Denmark)

    Leeb, Martin; Pasini, Diego; Novatchkova, Maria

    2010-01-01

    of genes that is redundantly repressed by PRC1 and PRC2 in ES cells. Furthermore, we find that genomic repeats are Polycomb targets and show that, in the absence of Polycomb complexes, endogenous murine leukemia virus elements can mobilize. This indicates a contribution of the Polycomb group system...... the formation of differentiated cells. ES cells lacking the function of either PRC1 or PRC2 can differentiate into cells of the three germ layers, whereas simultaneous loss of PRC1 and PRC2 abrogates differentiation. On the molecular level, the differentiation defect is caused by the derepression of a set...

  4. Top2 and Sgs1-Top3 Act Redundantly to Ensure rDNA Replication Termination.

    Directory of Open Access Journals (Sweden)

    Kamilla Mundbjerg

    2015-12-01

    Full Text Available Faithful DNA replication with correct termination is essential for genome stability and transmission of genetic information. Here we have investigated the potential roles of Topoisomerase II (Top2 and the RecQ helicase Sgs1 during late stages of replication. We find that cells lacking Top2 and Sgs1 (or Top3 display two different characteristics during late S/G2 phase, checkpoint activation and accumulation of asymmetric X-structures, which are both independent of homologous recombination. Our data demonstrate that checkpoint activation is caused by a DNA structure formed at the strongest rDNA replication fork barrier (RFB during replication termination, and consistently, checkpoint activation is dependent on the RFB binding protein, Fob1. In contrast, asymmetric X-structures are formed independent of Fob1 at less strong rDNA replication fork barriers. However, both checkpoint activation and formation of asymmetric X-structures are sensitive to conditions, which facilitate fork merging and progression of replication forks through replication fork barriers. Our data are consistent with a redundant role of Top2 and Sgs1 together with Top3 (Sgs1-Top3 in replication fork merging at rDNA barriers. At RFB either Top2 or Sgs1-Top3 is essential to prevent formation of a checkpoint activating DNA structure during termination, but at less strong rDNA barriers absence of the enzymes merely delays replication fork merging, causing an accumulation of asymmetric termination structures, which are solved over time.

  5. The Early-Acting Peroxin PEX19 Is Redundantly Encoded, Farnesylated, and Essential for Viability in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Margaret M McDonnell

    Full Text Available Peroxisomes are single-membrane bound organelles that are essential for normal development in plants and animals. In mammals and yeast, the peroxin (PEX proteins PEX3 and PEX19 facilitate the early steps of peroxisome membrane protein (PMP insertion and pre-peroxisome budding from the endoplasmic reticulum. The PEX3 membrane protein acts as a docking site for PEX19, a cytosolic chaperone for PMPs that delivers PMPs to the endoplasmic reticulum or peroxisomal membrane. PEX19 is farnesylated in yeast and mammals, and we used immunoblotting with prenylation mutants to show that PEX19 also is fully farnesylated in wild-type Arabidopsis thaliana plants. We examined insertional alleles disrupting either of the two Arabidopsis PEX19 isoforms, PEX19A or PEX19B, and detected similar levels of PEX19 protein in the pex19a-1 mutant and wild type; however, PEX19 protein was nearly undetectable in the pex19b-1 mutant. Despite the reduction in PEX19 levels in pex19b-1, both pex19a-1 and pex19b-1 single mutants lacked notable peroxisomal β-oxidation defects and displayed normal levels and localization of peroxisomal matrix and membrane proteins. The pex19a-1 pex19b-1 double mutant was embryo lethal, indicating a redundantly encoded critical role for PEX19 during embryogenesis. Expressing YFP-tagged versions of either PEX19 isoform rescued this lethality, confirming that PEX19A and PEX19B act redundantly in Arabidopsis. We observed that pex19b-1 enhanced peroxisome-related defects of a subset of peroxin-defective mutants, supporting a role for PEX19 in peroxisome function. Together, our data indicate that Arabidopsis PEX19 promotes peroxisome function and is essential for viability.

  6. Redundant cis-acting determinants of 3' processing and RNA stability in the chloroplast rbcL mRNA of Chlamydomonas.

    Science.gov (United States)

    Goldschmidt-Clermont, Michel; Rahire, Michèle; Rochaix, Jean-David

    2008-02-01

    We have designed a screen for mutants affected in 3' maturation of the chloroplast rbcL mRNA in Chlamydomonas reinhardtii. We inserted a spectinomycin resistance cassette, 5'atpA::aadA::3'rbcL, in a peripheral domain of tscA, the gene for a small non-coding RNA involved in trans-splicing of psaA. Depending on the orientation of the cassette, a polar effect was observed which was due to processing at the 3'rbcL element: the chimeric tscA RNA was truncated and splicing of psaA was blocked. We selected phenotypic revertants of this insertion mutant that restored psaA splicing, which correlated with the presence of chimeric transcripts that regained the 3' part of tscA. We analyzed two nuclear and six chloroplast suppressors. Five chloroplast mutations altered a short element in the center of the second inverted repeat in the 3'rbcL (IR2), and one deleted a larger region including this element. These mutations revealed a cis-acting element in IR2 which is required for 3' processing. When the same mutations were inserted in the 3' untranslated region (UTR) of the native rbcL gene, the rbcL mRNA accumulated to normal levels, but in strong alleles its 3' end was located upstream, near the end of the first inverted repeat (IR1). Deletion of either IR1 or IR2 allowed stable accumulation of rbcL mRNA, but deletion of both resulted in its complete absence. This indicated that the two inverted repeats function as redundant mRNA stability determinants in the 3' UTR of rbcL.

  7. Redundant Design in Interdependent Networks.

    Directory of Open Access Journals (Sweden)

    Lijun Liu

    Full Text Available Modern infrastructure networks are often coupled together and thus could be modeled as interdependent networks. Overload and interdependent effect make interdependent networks more fragile when suffering from attacks. Existing research has primarily concentrated on the cascading failure process of interdependent networks without load, or the robustness of isolated network with load. Only limited research has been done on the cascading failure process caused by overload in interdependent networks. Redundant design is a primary approach to enhance the reliability and robustness of the system. In this paper, we propose two redundant methods, node back-up and dependency redundancy, and the experiment results indicate that two measures are effective and costless. Two detailed models about redundant design are introduced based on the non-linear load-capacity model. Based on the attributes and historical failure distribution of nodes, we introduce three static selecting strategies-Random-based, Degree-based, Initial load-based and a dynamic strategy-HFD (historical failure distribution to identify which nodes could have a back-up with priority. In addition, we consider the cost and efficiency of different redundant proportions to determine the best proportion with maximal enhancement and minimal cost. Experiments on interdependent networks demonstrate that the combination of HFD and dependency redundancy is an effective and preferred measure to implement redundant design on interdependent networks. The results suggest that the redundant design proposed in this paper can permit construction of highly robust interactive networked systems.

  8. 36 CFR 1193.35 - Redundancy and selectability. [Reserved

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Redundancy and selectability. 1193.35 Section 1193.35 Parks, Forests, and Public Property ARCHITECTURAL AND TRANSPORTATION BARRIERS COMPLIANCE BOARD TELECOMMUNICATIONS ACT ACCESSIBILITY GUIDELINES Requirements for Accessibility and Usability...

  9. Exploring Redundancy in SocialWork Education

    Directory of Open Access Journals (Sweden)

    Bruce Dalton

    2003-05-01

    Full Text Available The issue of redundancy has not been well explored in the social work curriculum. The Educational Policy and Accreditation Standards (EPAS (CSWE, 2001 requires redundancy in the form of integration of material across content areas and addresses redundancy vertically between levels of education and year of program. Furthermore, research and theory support the notion that various types of redundancy produce educational benefits.This paper uniquely uses MSW students to track instances of redundancy over their first year of study and distinguishes between helpful and unhelpful redundancy. It presents both the study results and a description of the study process so that other schools may use or adapt it.

  10. Kinematically Optimal Robust Control of Redundant Manipulators

    Science.gov (United States)

    Galicki, M.

    2017-12-01

    This work deals with the problem of the robust optimal task space trajectory tracking subject to finite-time convergence. Kinematic and dynamic equations of a redundant manipulator are assumed to be uncertain. Moreover, globally unbounded disturbances are allowed to act on the manipulator when tracking the trajectory by the endeffector. Furthermore, the movement is to be accomplished in such a way as to minimize both the manipulator torques and their oscillations thus eliminating the potential robot vibrations. Based on suitably defined task space non-singular terminal sliding vector variable and the Lyapunov stability theory, we derive a class of chattering-free robust kinematically optimal controllers, based on the estimation of transpose Jacobian, which seem to be effective in counteracting both uncertain kinematics and dynamics, unbounded disturbances and (possible) kinematic and/or algorithmic singularities met on the robot trajectory. The numerical simulations carried out for a redundant manipulator of a SCARA type consisting of the three revolute kinematic pairs and operating in a two-dimensional task space, illustrate performance of the proposed controllers as well as comparisons with other well known control schemes.

  11. Redundant arrays of IDE drives

    Science.gov (United States)

    Sanders, D. A.; Cremaldi, L. M.; Eschenburg, V.; Lawrence, C. N.; Riley, C.; Summers, D. J.; Petravick, D. L.

    2002-08-01

    The next generation of high-energy physics experiments is expected to gather prodigious amounts of data. New methods must be developed to handle this data and make analysis at universities possible. We examine some techniques that use recent developments in commodity hardware. We test redundant arrays of integrated drive electronics (IDE) disk drives for use in offline high-energy physics data analysis. IDE redundant array of inexpensive disks (RAID) arrays prices now equal the cost per terabyte of million dollar tape robots! The arrays can be scaled to sizes affordable to institutions without robots and used when fast random access at low cost is important. We also explore three methods of moving data between sites; internet transfers, hot pluggable IDE disks in FireWire cases, and writable digital video disks (DVD-R) disks.

  12. Are interim management statements redundant?

    OpenAIRE

    Schleicher, T.; Walker, Martin

    2015-01-01

    In 2004 the Transparency Directive increased the reporting frequency by mandating the Interim Management Statement (IMS). However, only nine years later, the EU announced that it was making quarterly reporting voluntary again arguing that IMSs are redundant as they are unlikely to contain any additional information not already required by the Market Abuse Directive (MAD). The current paper tests this argument empirically. For that it collects data on trading statements from a post-MAD pre-IMS...

  13. Exploring Redundancy in SocialWork Education

    OpenAIRE

    Bruce Dalton; Lois Wright

    2003-01-01

    The issue of redundancy has not been well explored in the social work curriculum. The Educational Policy and Accreditation Standards (EPAS) (CSWE, 2001) requires redundancy in the form of integration of material across content areas and addresses redundancy vertically between levels of education and year of program. Furthermore, research and theory support the notion that various types of redundancy produce educational benefits.This paper uniquely uses MSW students to track ...

  14. General Solutions to Functional and Kinematic Redundancy

    Directory of Open Access Journals (Sweden)

    Pål J. From

    2008-04-01

    Full Text Available A systematic and general approach to represent functional redundancy is presented. It is shown how this approach allows the freedom provided by functional redundancy to be integrated into the inverse geometric problem for real-time applications and how it can be utilised to improve performance. A set of new iterative solutions to the inverse geometric problem, well suited for kinematically redundant manipulators, is also presented.

  15. Methods for investigating parameter redundancy

    Directory of Open Access Journals (Sweden)

    Gimenez, O.

    2004-06-01

    Full Text Available The quantitative study of marked individuals relies mainly on the use of meaningful biological models. Classical inference is then conducted based on the model likelihood, parameterized by parameters such as survival, recovery, transition and recapture probabilities. In classical statistics, we seek parameter estimates by maximising the likelihood. However, models are often overparameterized and, as a consequence, some parameters cannot be estimated separately. Identifying how many and which (functions of parameters are estimable is thus crucial not only for proper model selection based upon likelihood ratio tests or information criteria but also for the interpretation of the estimates obtained. In this paper, we provide the reader with a description of the tools available to check for parameter redundancy. We aim to assist people in choosing the most appropriate method to solve their own specific problems.

  16. Redundant Arrays of IDE Drives

    CERN Document Server

    Sanders, D A; Eschenburg, V; Lawrence, C N; Riley, C P; Summers, D J; Petravick, D L

    2001-01-01

    We report tests of redundant arrays of IDE disk drives for use in offline high energy physics data analysis. Parts costs of total systems using commodity EIDE disks are now at the $4000 per Terabyte level. Disk storage prices have now decreased to the point where they equal the cost per Terabyte of Storage Technology tape silos. The disks, however, offer far better granularity; even small institutions can afford to deploy systems. Our tests include reports on software RAID-5 systems running under Linux 2.4 using Promise Ultra 100 TM disk controllers. RAID-5 protects data in case of a single disk failure by providing parity bits. Tape backup is not required. Journaling file systems are used to allow rapid recovery from crashes. Our data analysis strategy is to encapsulate data and CPU processing power. Analysis for a particular part of a data set takes place on the PC where the data resides. The network is only used to put results together. We explore three methods of moving data between sites; internet transf...

  17. Redundant arrays of IDE drives

    Energy Technology Data Exchange (ETDEWEB)

    D.A. Sanders et al.

    2002-01-02

    The authors report tests of redundant arrays of IDE disk drives for use in offline high energy physics data analysis. Parts costs of total systems using commodity EIDE disks are now at the $4000 per Terabyte level. Disk storage prices have now decreased to the point where they equal the cost per Terabyte of Storage Technology tape silos. The disks, however, offer far better granularity; even small institutions can afford to deploy systems. The tests include reports on software RAID-5 systems running under Linux 2.4 using Promise Ultra 100{trademark} disk controllers. RAID-5 protects data in case of a single disk failure by providing parity bits. Tape backup is not required. Journaling file systems are used to allow rapid recovery from crashes. The data analysis strategy is to encapsulate data and CPU processing power. Analysis for a particular part of a data set takes place on the PC where the data resides. The network is only used to put results together. They explore three methods of moving data between sites; internet transfers, not pluggable IDE disks in FireWire cases, and DVD-R disks.

  18. Exploiting Redundancy in an OFDM SDR Receiver

    Directory of Open Access Journals (Sweden)

    Tomas Palenik

    2009-01-01

    Full Text Available Common OFDM system contains redundancy necessary to mitigate interblock interference and allows computationally effective single-tap frequency domain equalization in receiver. Assuming the system implements an outer error correcting code and channel state information is available in the receiver, we show that it is possible to understand the cyclic prefix insertion as a weak inner ECC encoding and exploit the introduced redundancy to slightly improve error performance of such a system. In this paper, an easy way to implement modification to an existing SDR OFDM receiver is presented. This modification enables the utilization of prefix redundancy, while preserving full compatibility with existing OFDM-based communication standards.

  19. Redundant correlation effect on personalized recommendation

    Science.gov (United States)

    Qiu, Tian; Han, Teng-Yue; Zhong, Li-Xin; Zhang, Zi-Ke; Chen, Guang

    2014-02-01

    The high-order redundant correlation effect is investigated for a hybrid algorithm of heat conduction and mass diffusion (HHM), through both heat conduction biased (HCB) and mass diffusion biased (MDB) correlation redundancy elimination processes. The HCB and MDB algorithms do not introduce any additional tunable parameters, but keep the simple character of the original HHM. Based on two empirical datasets, the Netflix and MovieLens, the HCB and MDB are found to show better recommendation accuracy for both the overall objects and the cold objects than the HHM algorithm. Our work suggests that properly eliminating the high-order redundant correlations can provide a simple and effective approach to accurate recommendation.

  20. A Modular Approach to Redundant Robot Control

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.J.

    1997-12-01

    This paper describes a modular approach for computing redundant robot kinematics. First some conventional redundant control methods are presented and shown to be `passive control laws`, i.e. they can be represented by a network consisting of passive elements. These networks are then put into modular form by applying scattering operator techniques. Additional subnetwork modules can then be added to further shape the motion. Modules for obstacle detection, joint limit avoidance, proximity sensing, and for imposing nonlinear velocity constraints are presented. The resulting redundant robot control system is modular, flexible and robust.

  1. Image Registration Using Redundant Wavelet Transforms

    National Research Council Canada - National Science Library

    Brown, Richard

    2001-01-01

    .... In our research, we present a fundamentally new wavelet-based registration algorithm utilizing redundant transforms and a masking process to suppress the adverse effects of noise and improve processing efficiency...

  2. Redundant Information Presentation in Hypertext Learning Environments

    NARCIS (Netherlands)

    Bezdan, Eniko; Kester, Liesbeth; Kirschner, Paul A.

    2011-01-01

    Bezdan, E., Kester, L., & Kirschner, P. A. (2011, 29 August). Redundant Information Presentation in Hypertext Learning Environments. Presentation at the pre-conference of the Junior Researchers of EARLI, Exeter, United Kingdom.

  3. The correlation between diverticulosis and redundant colon.

    Science.gov (United States)

    Cuda, Tahleesa; Gunnarsson, Ronny; de Costa, Alan

    2017-11-01

    Diverticulosis and redundant colon are colonic conditions for which underlying pathophysiology, management and prevention are poorly understood. Historical papers suggest an inverse relationship between these two conditions. However, no further attempt has been made to validate this relationship. This study set out to assess the correlation between diverticulosis and colonic redundancy. Redundant colon, diverticulosis and patient demographics were recorded during colonoscopy. Multivariate binary logistic regression was performed with redundant colon as the dependent variable and age, gender and diverticulosis as independent variables. Nagelkerke R 2 and a receiver operator curve were calculated to assess goodness of fit and internally validate the multivariate model. Redundant colon and diverticulosis were diagnosed in 31 and 113 patients, respectively. The probability of redundant colon was increased by female gender odds ratio (OR) 8.4 (95% CI 2.7-26, p = 0.00020) and increasing age OR 1.7 (95% CI 1.1-2.6, p = 0.017). Paradoxically, diverticulosis strongly reduced the probability of redundant colon with OR of 0.12 (95% CI 0.42-0.32, p = 0.000039). The Nagelkerke R 2 for the multivariate model was 0.29 and the area under the curve at ROC analysis was 0.81 (95% CI 0.73-0.90 p-value 3.1 × 10-8). This study found an inverse correlation between redundant colon and diverticulosis, supporting the historical suggestion that the two conditions rarely occur concurrently. The underlying principle for this relationship remains to be found. However, it may contribute to the understanding of the aetiology and pathophysiology of these colonic conditions.

  4. Dynamic Control of Kinematically Redundant Robotic Manipulators

    Directory of Open Access Journals (Sweden)

    Erling Lunde

    1987-07-01

    Full Text Available Several methods for task space control of kinematically redundant manipulators have been proposed in the literature. Most of these methods are based on a kinematic analysis of the manipulator. In this paper we propose a control algorithm in which we are especially concerned with the manipulator dynamics. The algorithm is particularly well suited for the class of redundant manipulators consisting of a relatively small manipulator mounted on a larger positioning part.

  5. Optimum Cyclic Redundancy Codes for Noisy Channels

    Science.gov (United States)

    Posner, E. C.; Merkey, P.

    1986-01-01

    Capabilities and limitations of cyclic redundancy codes (CRC's) for detecting transmission errors in data sent over relatively noisy channels (e.g., voice-grade telephone lines or very-high-density storage media) discussed in 16-page report. Due to prevalent use of bytes in multiples of 8 bits data transmission, report primarily concerned with cases in which both block length and number of redundant bits (check bits for use in error detection) included in each block are multiples of 8 bits.

  6. Intrasensory Redundancy Facilitates Infant Detection of Tempo: Extending Predictions of the Intersensory Redundancy Hypothesis.

    Science.gov (United States)

    Bahrick, Lorraine E; Lickliter, Robert; Castellanos, Irina; Todd, James Torrence

    2015-01-01

    Research has demonstrated that intersensory redundancy (stimulation synchronized across multiple senses) is highly salient and facilitates processing of amodal properties in multimodal events, bootstrapping early perceptual development. The present study is the first to extend this central principle of the intersensory redundancy hypothesis (IRH) to certain types of intrasensory redundancy (stimulation synchronized within a single sense). Infants were habituated to videos of a toy hammer tapping silently (unimodal control), depicting intersensory redundancy (synchronized with a soundtrack) or intrasensory redundancy (synchronized with another visual event; light flashing or bat tapping). In Experiment 1, 2-month-olds showed both intersensory and intrasensory facilitation (with respect to the unimodal control) for detecting a change in tempo. However, intrasensory facilitation was found when the hammer was synchronized with the light flashing (different motion) but not with the bat tapping (same motion). Experiment 2 tested 3-month-olds using a somewhat easier tempo contrast. Results supported a similarity hypothesis: intrasensory redundancy between two dissimilar events was more effective than that between two similar events for promoting processing of amodal properties. These findings extend the IRH and indicate that in addition to intersensory redundancy, intrasensory redundancy between two synchronized dissimilar visual events is also effective in promoting perceptual processing of amodal event properties.

  7. Minimum Redundancy Coding for Uncertain Sources

    CERN Document Server

    Baer, Michael B; Charalambous, Charalambos D

    2011-01-01

    Consider the set of source distributions within a fixed maximum relative entropy with respect to a given nominal distribution. Lossless source coding over this relative entropy ball can be approached in more than one way. A problem previously considered is finding a minimax average length source code. The minimizing players are the codeword lengths --- real numbers for arithmetic codes, integers for prefix codes --- while the maximizing players are the uncertain source distributions. Another traditional minimizing objective is the first one considered here, maximum (average) redundancy. This problem reduces to an extension of an exponential Huffman objective treated in the literature but heretofore without direct practical application. In addition to these, this paper examines the related problem of maximal minimax pointwise redundancy and the problem considered by Gawrychowski and Gagie, which, for a sufficiently small relative entropy ball, is equivalent to minimax redundancy. One can consider both Shannon-...

  8. Impedance Control of a Redundant Parallel Manipulator

    DEFF Research Database (Denmark)

    Méndez, Juan de Dios Flores; Schiøler, Henrik; Madsen, Ole

    2017-01-01

    This paper presents the design of Impedance Control to a redundantly actuated Parallel Kinematic Manipulator. The proposed control is based on treating each limb as a single system and their connection through the internal interaction forces. The controller introduces a stiffness and damping matr...

  9. Semantically Redundant Language--A Case Study

    Science.gov (United States)

    Rizza, Chris

    2009-01-01

    In this article, I discuss the concept of semantically redundant language through a case study of the Te Rauparaha Maori haka. I suggest that current linguistic theories cannot give a full account of ritualized speech events, of which the haka is an example, as these theories are based on a traditional dyadic model of interaction involving a…

  10. Redundant Array Configurations for 21 cm Cosmology

    Science.gov (United States)

    Dillon, Joshua S.; Parsons, Aaron R.

    2016-08-01

    Realizing the potential of 21 cm tomography to statistically probe the intergalactic medium before and during the Epoch of Reionization requires large telescopes and precise control of systematics. Next-generation telescopes are now being designed and built to meet these challenges, drawing lessons from first-generation experiments that showed the benefits of densely packed, highly redundant arrays—in which the same mode on the sky is sampled by many antenna pairs—for achieving high sensitivity, precise calibration, and robust foreground mitigation. In this work, we focus on the Hydrogen Epoch of Reionization Array (HERA) as an interferometer with a dense, redundant core designed following these lessons to be optimized for 21 cm cosmology. We show how modestly supplementing or modifying a compact design like HERA’s can still deliver high sensitivity while enhancing strategies for calibration and foreground mitigation. In particular, we compare the imaging capability of several array configurations, both instantaneously (to address instrumental and ionospheric effects) and with rotation synthesis (for foreground removal). We also examine the effects that configuration has on calibratability using instantaneous redundancy. We find that improved imaging with sub-aperture sampling via “off-grid” antennas and increased angular resolution via far-flung “outrigger” antennas is possible with a redundantly calibratable array configuration.

  11. Redundant internal coordinates, compliance constants and non ...

    Indian Academy of Sciences (India)

    Redundant internal coordinates, compliance constants and non-bonded interactions – some new insights. MOUMITA MAJUMDER and SADASIVAM MANOGARAN. ∗. Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India e-mail: sm@iitk.ac.in. MS received 21 February 2012; revised 8 July ...

  12. Impedance Control of a Redundant Parallel Manipulator

    DEFF Research Database (Denmark)

    Méndez, Juan de Dios Flores; Schiøler, Henrik; Madsen, Ole

    2017-01-01

    This paper presents the design of Impedance Control to a redundantly actuated Parallel Kinematic Manipulator. The proposed control is based on treating each limb as a single system and their connection through the internal interaction forces. The controller introduces a stiffness and damping...

  13. On Redundancy in Describing Linguistic Systems

    Directory of Open Access Journals (Sweden)

    Vladimir Borissov Pericliev

    2015-12-01

    Full Text Available On Redundancy in Describing Linguistic Systems The notion of system of linguistic elements figures prominently in most post-Saussurian linguistics up to the present. A “system” is the network of the contrastive (or, distinctive features each element in the system bears to the remaining elements. The meaning (valeur of each element in the system is the set of features that are necessary and jointly sufficient to distinguish this element from all others. The paper addresses the problems of “redundancy”, i.e. the occurrence of features that are not strictly necessary in describing an element in a system. Redundancy is shown to smuggle into the description of linguistic systems, this infelicitous practice illustrated with some examples from the literature (e.g. the classical phonemic analysis of Russian by Cherry, Halle, and Jakobson, 1953. The logic and psychology of the occurrence of redundancy are briefly sketched and it is shown that, in addition to some other problems, redundancy leads to a huge and unresolvable ambiguity of descriptions of linguistic systems (the Buridan’s ass problem.

  14. Redundant Elements in SNOMED CT Concept Definitions

    NARCIS (Netherlands)

    Dentler, Kathrin; Cornet, Ronald

    2013-01-01

    While redundant elements in SNOMED CT concept definitions are harmless from a logical point of view, they unnecessarily make concept definitions of typically large ontologies such as SNOMED CT hard to construct and to maintain. In this paper, we apply a fully automated method to detect intra-axiom

  15. Beyond redundancy how geographic redundancy can improve service availability and reliability of computer-based systems

    CERN Document Server

    Bauer, Eric; Eustace, Dan

    2012-01-01

    "While geographic redundancy can obviously be a huge benefit for disaster recovery, it is far less obvious what benefit is feasible and likely for more typical non-catastrophic hardware, software, and human failures. Georedundancy and Service Availability provides both a theoretical and practical treatment of the feasible and likely benefits of geographic redundancy for both service availability and service reliability. The text provides network/system planners, IS/IT operations folks, system architects, system engineers, developers, testers, and other industry practitioners with a general discussion about the capital expense/operating expense tradeoff that frames system redundancy and georedundancy"--

  16. RedundancyMiner: De-replication of redundant GO categories in microarray and proteomics analysis

    Directory of Open Access Journals (Sweden)

    Reinhold William

    2011-02-01

    Full Text Available Abstract Background The Gene Ontology (GO Consortium organizes genes into hierarchical categories based on biological process, molecular function and subcellular localization. Tools such as GoMiner can leverage GO to perform ontological analysis of microarray and proteomics studies, typically generating a list of significant functional categories. Two or more of the categories are often redundant, in the sense that identical or nearly-identical sets of genes map to the categories. The redundancy might typically inflate the report of significant categories by a factor of three-fold, create an illusion of an overly long list of significant categories, and obscure the relevant biological interpretation. Results We now introduce a new resource, RedundancyMiner, that de-replicates the redundant and nearly-redundant GO categories that had been determined by first running GoMiner. The main algorithm of RedundancyMiner, MultiClust, performs a novel form of cluster analysis in which a GO category might belong to several category clusters. Each category cluster follows a "complete linkage" paradigm. The metric is a similarity measure that captures the overlap in gene mapping between pairs of categories. Conclusions RedundancyMiner effectively eliminated redundancies from a set of GO categories. For illustration, we have applied it to the clarification of the results arising from two current studies: (1 assessment of the gene expression profiles obtained by laser capture microdissection (LCM of serial cryosections of the retina at the site of final optic fissure closure in the mouse embryos at specific embryonic stages, and (2 analysis of a conceptual data set obtained by examining a list of genes deemed to be "kinetochore" genes.

  17. Task-Directed Inverse Kinematics For Redundant Manipulators

    Science.gov (United States)

    Long, Mark K.

    1994-01-01

    Paper presents algorithms for use in controlling redundant robotic manipulators in such way as to exploit redundancy to satisfy task requirements beyond placement of end effectors at desired positions and orientations.

  18. Redundancy of einselected information in quantum Darwinism: The irrelevance of irrelevant environment bits

    Science.gov (United States)

    Zwolak, Michael; Zurek, Wojciech H.

    2017-03-01

    The objective, classical world emerges from the underlying quantum substrate via the proliferation of redundant copies of selected information into the environment, which acts as a communication channel, transmitting that information to observers. These copies are independently accessible, allowing many observers to reach consensus about the state of a quantum system via its imprints in the environment. Quantum Darwinism recognizes that the redundancy of information is thus central to the emergence of objective reality in the quantum world. However, in addition to the "quantum system of interest," there are many other systems "of no interest" in the Universe that can imprint information on the common environment. There is therefore a danger that the information of interest will be diluted with irrelevant bits, suppressing the redundancy responsible for objectivity. We show that mixing of the relevant (the "wheat") and irrelevant (the "chaff") bits of information makes little quantitative difference to the redundancy of the information of interest. Thus, we demonstrate that it does not matter whether one separates the wheat (relevant information) from the (irrelevant) chaff: The large redundancy of the relevant information survives dilution, providing evidence of the objective, effectively classical world.

  19. Optimal control tuning of a redundant robot

    OpenAIRE

    Jaulin, Luc

    2012-01-01

    International audience; A robot can generally be described by a vector first-order differential equation, named state equations. A robot is said to be redundant if it has more actuators than necessary. In this case, the number of inputs is higher than the number of outputs (variables to be controlled) and there exists many different ways to achieve the control requirements. We can thus take advantage of the extra number of freedom degrees in order to optimize some performance criterion (invol...

  20. Impedance Control of a Redundant Parallel Manipulator

    DEFF Research Database (Denmark)

    Méndez, Juan de Dios Flores; Schiøler, Henrik; Madsen, Ole

    2017-01-01

    This paper presents the design of Impedance Control to a redundantly actuated Parallel Kinematic Manipulator. The proposed control is based on treating each limb as a single system and their connection through the internal interaction forces. The controller introduces a stiffness and damping...... matrices that decouples the dynamic behaviour of the robot. Control allocation of torques is applied through an optimization that promotes even distribution of torques over actuators. Simulations showed a good compliance behaviour in low frequencies....

  1. Distributed redundancy and robustness in complex systems

    KAUST Repository

    Randles, Martin

    2011-03-01

    The uptake and increasing prevalence of Web 2.0 applications, promoting new large-scale and complex systems such as Cloud computing and the emerging Internet of Services/Things, requires tools and techniques to analyse and model methods to ensure the robustness of these new systems. This paper reports on assessing and improving complex system resilience using distributed redundancy, termed degeneracy in biological systems, to endow large-scale complicated computer systems with the same robustness that emerges in complex biological and natural systems. However, in order to promote an evolutionary approach, through emergent self-organisation, it is necessary to specify the systems in an \\'open-ended\\' manner where not all states of the system are prescribed at design-time. In particular an observer system is used to select robust topologies, within system components, based on a measurement of the first non-zero Eigen value in the Laplacian spectrum of the components\\' network graphs; also known as the algebraic connectivity. It is shown, through experimentation on a simulation, that increasing the average algebraic connectivity across the components, in a network, leads to an increase in the variety of individual components termed distributed redundancy; the capacity for structurally distinct components to perform an identical function in a particular context. The results are applied to a specific application where active clustering of like services is used to aid load balancing in a highly distributed network. Using the described procedure is shown to improve performance and distribute redundancy. © 2010 Elsevier Inc.

  2. Monitoring electromagnetic tracking error using redundant sensors

    Science.gov (United States)

    Harish, Vinyas; Bibic, Eden; Lasso, Andras; Holden, Matthew S.; Vaughan, Thomas; Baum, Zachary; Ungi, Tamas; Fichtinger, Gabor

    2017-03-01

    PURPOSE: The intraoperative measurement of tracking error is crucial to ensure the reliability of electromagnetically navigated procedures. For intraoperative use, methods need to be quick to set up, easy to interpret, and not interfere with the ongoing procedure. Our goal was to evaluate the feasibility of using redundant electromagnetic sensors to alert users to tracking error in a navigated intervention setup. METHODS: Electromagnetic sensors were fixed to a rigid frame around a region of interest and on surgical tools. A software module was designed to detect tracking error by comparing real-time measurements of the differences between inter-sensor distances and angles to baseline measurements. Once these measurements were collected, a linear support vector machine-based classifier was used to predict tracking errors from redundant sensor readings. RESULTS: Measuring the deviation in the reported inter-sensor distance and angle between the needle and cautery served as a valid indicator for electromagnetic tracking error. The highest classification accuracy, 86%, was achieved based on readings from the cautery when the two sensors on the cautery were close together. The specificity of this classifier was 93% and the sensitivity was 82%. CONCLUSION: Placing redundant electromagnetic sensors in a workspace seems to be feasible for the intraoperative detection of electromagnetic tracking error in controlled environments. Further testing should be performed to optimize the measurement error threshold used for classification in the support vector machine, and improve the sensitivity of our method before application in real procedures.

  3. The conservation of redundancy in genetic systems: effects of sexual ...

    Indian Academy of Sciences (India)

    Model one is then used to study the conservation of redundancy during sexual and asexual reproduction. A unicellular haploid organism reproducing asexually retains redundancy when the mutation rate is very low (0.001 per cell division), but tends to lose high levels of redundancy if the mutation rate is increased (0.01 to ...

  4. Nonlinear Redundancy Analysis. Research Report 88-1.

    Science.gov (United States)

    van der Burg, Eeke; de Leeuw, Jan

    A non-linear version of redundancy analysis is introduced. The technique is called REDUNDALS. It is implemented within the computer program for canonical correlation analysis called CANALS. The REDUNDALS algorithm is of an alternating least square (ALS) type. The technique is defined as minimization of a squared distance between criterion…

  5. Redundancy allocation problem for k-out-of- n systems with a choice of redundancy strategies

    Science.gov (United States)

    Aghaei, Mahsa; Zeinal Hamadani, Ali; Abouei Ardakan, Mostafa

    2017-11-01

    To increase the reliability of a specific system, using redundant components is a common method which is called redundancy allocation problem (RAP). Some of the RAP studies have focused on k-out-of- n systems. However, all of these studies assumed predetermined active or standby strategies for each subsystem. In this paper, for the first time, we propose a k-out-of- n system with a choice of redundancy strategies. Therefore, a k-out-of- n series-parallel system is considered when the redundancy strategy can be chosen for each subsystem. In other words, in the proposed model, the redundancy strategy is considered as an additional decision variable and an exact method based on integer programming is used to obtain the optimal solution of the problem. As the optimization of RAP belongs to the NP-hard class of problems, a modified version of genetic algorithm (GA) is also developed. The exact method and the proposed GA are implemented on a well-known test problem and the results demonstrate the efficiency of the new approach compared with the previous studies.

  6. How redundant are redundant color adjectives? An efficiency-based analysis of color overspecification

    Directory of Open Access Journals (Sweden)

    Paula eRubio-Fernández

    2016-02-01

    Full Text Available Color adjectives tend to be used redundantly in referential communication. I propose that redundant color adjectives are often intended to exploit a color contrast in the visual context and hence facilitate object identification, despite not being necessary to establish unique reference. Two language-production experiments investigated two types of factors that may affect the use of redundant color adjectives: factors related to the efficiency of color in the visual context and factors related to the semantic category of the noun. The results of Experiment 1 confirmed that people produce redundant color adjectives when color may facilitate object recognition; e.g., they do so more often in polychrome displays than in monochrome displays, and more often in English (pre-nominal position than in Spanish (post-nominal position. Redundant color adjectives are also used when color is a central property of the object category; e.g., people referred to the color of clothes more often than to the color of geometrical figures (Experiment 1, and they overspecified atypical colors more often than variable and stereotypical colors (Experiment 2. These results are relevant for pragmatic models of referential communication based on Gricean pragmatics and informativeness. An alternative analysis is proposed, which focuses on the efficiency and pertinence of color in a given referential situation.

  7. Language as an information system: redundancy and optimization

    Directory of Open Access Journals (Sweden)

    Irina Mikhaylovna Nekipelova

    2015-11-01

    Full Text Available The paper is devoted to research of the language system as an information system. The distinguishing feature of any natural living language system is redundant of elements of its structure. Redundancy, broken terms of universality peculiar to artificial information systems, makes language mobile in time and in space. It should be marked out informational redundancy of two types: language redundancy, when information overlay of language units within the system occurs and speech redundancy when condense of information into syntagmatic level occurs. Language redundancy is potential and speech redundancy is actual. In general, it should be noted that the language redundancy is necessary for language: complicating the relationships between language units, language redundancy creates in language situation of choice, leading to a disorder of language system, increasing of entropy and, as a result, the appearing of the information that can be accepted or cannot be by language system. Language redundancy is one of the reasons for growth of information in language. In addition, the information redundancy in language is one of the factors of language system development.

  8. A Model-Based Case for Redundant Computation

    Energy Technology Data Exchange (ETDEWEB)

    Stearley, Jon R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robinson, David Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ferreira, Kurt Brian [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Riesen, Rolf [IBM Research, Dublin (Ireland)

    2011-08-01

    Despite its seemingly nonsensical cost, we show through modeling and simulation that redundant computation merits full consideration as a resilience strategy for next-generation systems. Without revolutionary breakthroughs in failure rates, part counts, or stable-storage bandwidths, it has been shown that the utility of Exascale systems will be crushed by the overheads of traditional checkpoint/restart mechanisms. Alternate resilience strategies must be considered, and redundancy is a proven unrivaled approach in many domains. We develop a distribution-independent model for job interrupts on systems of arbitrary redundancy, adapt Daly’s model for total application runtime, and find that his estimate for optimal checkpoint interval remains valid for redundant systems. We then identify conditions where redundancy is more cost effective than non-redundancy. These are done in the context of the number one supercomputers of the last decade, showing that thorough consideration of redundant computation is timely - if not overdue.

  9. Redundant protective barriers: minimizing operator occupational risk.

    Science.gov (United States)

    Challa, Karthik; Warren, Stafford G; Danak, Subhash; Bates, Mark C

    2009-06-01

    The ubiquitous use of less invasive therapeutic angiographic procedures has created the milieu for long-term occupational risk of cancer and genetic defects. This study set out to determine the relative effectiveness of redundant radiation protective barriers and their impact on operator total-body-ionizing radiation exposure in the catheterization suite. Thermolucent dosimeter x-irradiation was measured inside and outside personal and movable protective barriers used concurrently during 50 consecutive procedures by a single operator. Additionally, the entrance/exit doses were recorded on the back and chest for all patients to provide insight into radiation scatter patterns. The x-ray beam had an average 90.8% decrement in energy traversing the patient's chest when entrance and exit doses were compared, suggesting a 3.3-fold greater operator scatter radiation exposure below the table compared with that above the table. All 0.5-mm lead equivalent personal barriers reduced operator exposure by 72-95%, whereas the 1.0-mm leaded personal barrier (overlapping gown) reduced exposure by 96%. The 0.75-mm leaded glasses reduced exposure to the left eye by 67%. A leaded left-hand glove reduced exposure by only 20%. The effective calculated operator radiation exposure risk reduction provided by the use of personal and movable barriers reduced the theoretical risk of fatal or nonfatal cancer by 22-fold while decreasing potential severe genetic effect by 25-fold in comparison to movable barriers alone. The optimal use of combined personal and movable (redundant) lead barriers results in a significant reduction in total-body operator radiation exposure in the catheterization laboratory. The use of redundant barriers in the catheterization suite is associated with a dramatic theoretical long-term occupational risk reduction and should be encouraged.

  10. Sharing the cost of redundant items

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moulin, Hervé

    2014-01-01

    are network connectivity problems when an existing (possibly inefficient) network must be maintained. We axiomatize a family cost ratios based on simple liability indices, one for each agent and for each item, measuring the relative worth of this item across agents, and generating cost allocation rules......We ask how to share the cost of finitely many public goods (items) among users with different needs: some smaller subsets of items are enough to serve the needs of each user, yet the cost of all items must be covered, even if this entails inefficiently paying for redundant items. Typical examples...... additive in costs....

  11. Does functional redundancy stabilize fish communities?

    DEFF Research Database (Denmark)

    Rice, Jake; Daan, Niels; Gislason, Henrik

    2013-01-01

    Functional redundancy of species sharing a feeding strategy and/or maximum size has been hypothesized to contribute to increased resilience of marine fish communities (the “portfolio effect”). A consistent time-series of survey data of fish in the North Sea was used to examine if trophic functional...... in abundance or biomass could be accounted for by the Law of Large Numbers, providing no evidence that specific ecological processes or co-adaptations are necessary to produce this effect. This implies that successful conservation policies to maintain the resilience of a marine fish community could be based...

  12. Redundancy of stereoscopic images: Experimental evaluation

    Science.gov (United States)

    Yaroslavsky, L. P.; Campos, J.; Espínola, M.; Ideses, I.

    2005-12-01

    With the recent advancement in visualization devices over the last years, we are seeing a growing market for stereoscopic content. In order to convey 3D content by means of stereoscopic displays, one needs to transmit and display at least 2 points of view of the video content. This has profound implications on the resources required to transmit the content, as well as demands on the complexity of the visualization system. It is known that stereoscopic images are redundant which may prove useful for compression and may have positive effect on the construction of the visualization device. In this paper we describe an experimental evaluation of data redundancy in color stereoscopic images. In the experiments with computer generated and real life test stereo images, several observers visually tested the stereopsis threshold and accuracy of parallax measurement in anaglyphs and stereograms as functions of the blur degree of one of two stereo images. In addition, we tested the color saturation threshold in one of two stereo images for which full color 3D perception with no visible color degradations was maintained. The experiments support a theoretical estimate that one has to add, to data required to reproduce one of two stereoscopic images, only several percents of that amount of data in order to achieve stereoscopic perception.

  13. Learners misperceive the benefits of redundant text in multimedia learning.

    Science.gov (United States)

    Fenesi, Barbara; Kim, Joseph A

    2014-01-01

    Research on metacognition has consistently demonstrated that learners fail to endorse instructional designs that produce benefits to memory, and often prefer designs that actually impair comprehension. Unlike previous studies in which learners were only exposed to a single multimedia design, the current study used a within-subjects approach to examine whether exposure to both redundant text and non-redundant text multimedia presentations improved learners' metacognitive judgments about presentation styles that promote better understanding. A redundant text multimedia presentation containing narration paired with verbatim on-screen text (Redundant) was contrasted with two non-redundant text multimedia presentations: (1) narration paired with images and minimal text (Complementary) or (2) narration paired with minimal text (Sparse). Learners watched presentation pairs of either Redundant + Complementary, or Redundant + Sparse. Results demonstrate that Complementary and Sparse presentations produced highest overall performance on the final comprehension assessment, but the Redundant presentation produced highest perceived understanding and engagement ratings. These findings suggest that learners misperceive the benefits of redundant text, even after direct exposure to a non-redundant, effective presentation.

  14. Amplification, Redundancy, and Quantum Chernoff Information

    Science.gov (United States)

    Zwolak, Michael; Riedel, C. Jess; Zurek, Wojciech H.

    2014-04-01

    Amplification was regarded, since the early days of quantum theory, as a mysterious ingredient that endows quantum microstates with macroscopic consequences, key to the "collapse of the wave packet," and a way to avoid embarrassing problems exemplified by Schrödinger's cat. Such a bridge between the quantum microworld and the classical world of our experience was postulated ad hoc in the Copenhagen interpretation. Quantum Darwinism views amplification as replication, in many copies, of the information about quantum states. We show that such amplification is a natural consequence of a broad class of models of decoherence, including the photon environment we use to obtain most of our information. This leads to objective reality via the presence of robust and widely accessible records of selected quantum states. The resulting redundancy (the number of copies deposited in the environment) follows from the quantum Chernoff information that quantifies the information transmitted by a typical elementary subsystem of the environment.

  15. Serial data transmission between redundant channels

    Science.gov (United States)

    Tulpule, Bhalchandra R. (Inventor); Binnall, Daniel G. (Inventor)

    1992-01-01

    Data is communicated between redundant channels formatted in blocks having an initial command word followed by a destination code, starting address and a variable number of data words including a word count. The blocks are transmitted between each channel and all of the channels over cross-channel data links, each channel receiving the data blocks and determining the validity thereof by counting the number of data words received and comparing that number to the word count transmitted for that block. An interrupt signal indicative of invalidity of a block is provided in the event of a miscompare. A stop address is generated for each block received for storage at the start address. A memory address is generated for each valid word received for storage in sequence starting immediately after the start address. The next block received has its start address placed immediately at the end of the previously received block.

  16. Amplification, redundancy, and quantum Chernoff information.

    Science.gov (United States)

    Zwolak, Michael; Riedel, C Jess; Zurek, Wojciech H

    2014-04-11

    Amplification was regarded, since the early days of quantum theory, as a mysterious ingredient that endows quantum microstates with macroscopic consequences, key to the "collapse of the wave packet," and a way to avoid embarrassing problems exemplified by Schrödinger's cat. Such a bridge between the quantum microworld and the classical world of our experience was postulated ad hoc in the Copenhagen interpretation. Quantum Darwinism views amplification as replication, in many copies, of the information about quantum states. We show that such amplification is a natural consequence of a broad class of models of decoherence, including the photon environment we use to obtain most of our information. This leads to objective reality via the presence of robust and widely accessible records of selected quantum states. The resulting redundancy (the number of copies deposited in the environment) follows from the quantum Chernoff information that quantifies the information transmitted by a typical elementary subsystem of the environment.

  17. Redundant information encoding in QED during decoherence

    Science.gov (United States)

    Tuziemski, J.; Witas, P.; Korbicz, J. K.

    2018-01-01

    Broadly understood decoherence processes in quantum electrodynamics, induced by neglecting either the radiation [L. Landau, Z. Phys. 45, 430 (1927), 10.1007/BF01343064] or the charged matter [N. Bohr and L. Rosenfeld, K. Danske Vidensk. Selsk, Math.-Fys. Medd. XII, 8 (1933)], have been studied from the dawn of the theory. However, what happens in between, when a part of the radiation may be observed, as is the case in many real-life situations, has not been analyzed yet. We present such an analysis for a nonrelativistic, pointlike charge and thermal radiation. In the dipole approximation, we solve the dynamics and show that there is a regime where, despite the noise, the observed field carries away almost perfect and hugely redundant information about the charge momentum. We analyze a partial charge-field state and show that it approaches a so-called spectrum broadcast structure.

  18. The communication of expectations and individual understanding: redundancy as reduction of uncertainty, and the processing of meaning

    NARCIS (Netherlands)

    Leydesdorff, L.; Johnson, M.; Ivanova, I.A.

    2014-01-01

    Purpose The purpose of this paper is to present the case for an analysis of communication at the supra-individual level as a means of rendering the understanding of learning and acting tractable. The paper introduces a method of analysis of redundancy to achieve this. Design/methodology/approach The

  19. Task-space separation principle: a force-field approach to motion planning for redundant manipulators.

    Science.gov (United States)

    Tommasino, Paolo; Campolo, Domenico

    2017-02-03

    In this work, we address human-like motor planning in redundant manipulators. Specifically, we want to capture postural synergies such as Donders' law, experimentally observed in humans during kinematically redundant tasks, and infer a minimal set of parameters to implement similar postural synergies in a kinematic model. For the model itself, although the focus of this paper is to solve redundancy by implementing postural strategies derived from experimental data, we also want to ensure that such postural control strategies do not interfere with other possible forms of motion control (in the task-space), i.e. solving the posture/movement problem. The redundancy problem is framed as a constrained optimization problem, traditionally solved via the method of Lagrange multipliers. The posture/movement problem can be tackled via the separation principle which, derived from experimental evidence, posits that the brain processes static torques (i.e. posture-dependent, such as gravitational torques) separately from dynamic torques (i.e. velocity-dependent). The separation principle has traditionally been applied at a joint torque level. Our main contribution is to apply the separation principle to Lagrange multipliers, which act as task-space force fields, leading to a task-space separation principle. In this way, we can separate postural control (implementing Donders' law) from various types of tasks-space movement planners. As an example, the proposed framework is applied to the (redundant) task of pointing with the human wrist. Nonlinear inverse optimization (NIO) is used to fit the model parameters and to capture motor strategies displayed by six human subjects during pointing tasks. The novelty of our NIO approach is that (i) the fitted motor strategy, rather than raw data, is used to filter and down-sample human behaviours; (ii) our framework is used to efficiently simulate model behaviour iteratively, until it converges towards the experimental human strategies.

  20. The conservation of redundancy in genetic systems: effects of sexual ...

    Indian Academy of Sciences (India)

    Unknown

    The dictionary definition of redundant is “superabundant, superfluous or in excess”. This is the way the term .... Thus the degree of redundancy varies with environmental pressure and a system with a superabundance of .... when the environment is less demanding, but the extra components are needed when conditions are ...

  1. Exploring the Boundary Conditions of the Redundancy Principle

    Science.gov (United States)

    McCrudden, Matthew T.; Hushman, Carolyn J.; Marley, Scott C.

    2014-01-01

    This experiment investigated whether study of a scientific text and a visual display that contained redundant text segments would affect memory and transfer. The authors randomly assigned 42 students from a university in the southwestern United States in equal numbers to 1 of 2 conditions: (a) a redundant condition, in which participants studied a…

  2. Network Gateway Technology: The Issue of Redundancy towards ...

    African Journals Online (AJOL)

    Network gateway redundancy technology makes it possible for computer devices to have access to multiple exit and entry points in the network, thus, eliminates the problem of a single point failure in both Ethernet and Internet networking systems. For effective implementation of network gateway redundancy, however, ideal ...

  3. Workspace and Kinematics Analysis of Redundant Space Manipulator

    Directory of Open Access Journals (Sweden)

    Zhang Jian-xia

    2016-01-01

    Full Text Available In order to meet the requirements of tasks in the complex space environment, we designed a kind of 7 degrees of freedom redundant space manipulator in this paper. Its 3D modelling is based on SolidWorks 2015. The joint coordinate system of redundant space manipulator is described with the Denavit-Hartenberg (D-H method. And the kinematic model is established. The direct kinematic equations of redundant space manipulator are derived by the homogeneous coordinate transforming matrices. The workspace is simulated and analysed using the Monte Carlo method. The experimental results showed that the workspace of 7 degrees of freedom redundant space manipulator, which was designed in this paper, changed smoothly. What’s more, it had not the abrupt phenomenon, and the independent part is bigger. Thus it verifies the rationality of our designing about the redundant space manipulator. It provides a good reference for the path planning and obstacle avoidance planning.

  4. Redundancy analysis of cooperative dual-arm manipulators

    Directory of Open Access Journals (Sweden)

    Alessandro Freddi

    2016-09-01

    Full Text Available This paper presents the redundancy analysis of two cooperative manipulators, showing how they can be considered as a single redundant manipulator through the use of the relative Jacobian matrix. In this way, the kinematic redundancy can be resolved by applying the principal local optimization techniques used in the single manipulator case. We resolve the redundancy by using the Jacobian null space technique, which permits us to perform several tasks with different execution priority levels at the same time; this is a useful feature, especially when the manipulators are to be mounted on and cooperate with a mobile platform. As an illustrative example, we present a case study consisting of two planar manipulators mounted on a smart wheelchair, whose degrees of redundancy are employed to move an object along a pre-defined path, while avoiding an obstacle in the manipulator’s workspace at the same time.

  5. Redundancy among Manganese Peroxidases in Pleurotus ostreatus

    Science.gov (United States)

    Salame, Tomer M.; Knop, Doriv; Levinson, Dana; Yarden, Oded

    2013-01-01

    Manganese peroxidases (MnPs) are key players in the ligninolytic system of white rot fungi. In Pleurotus ostreatus (the oyster mushroom) these enzymes are encoded by a gene family comprising nine members, mnp1 to -9 (mnp genes). Mn2+ amendment to P. ostreatus cultures results in enhanced degradation of recalcitrant compounds (such as the azo dye orange II) and lignin. In Mn2+-amended glucose-peptone medium, mnp3, mnp4, and mnp9 were the most highly expressed mnp genes. After 7 days of incubation, the time point at which the greatest capacity for orange II decolorization was observed, mnp3 expression and the presence of MnP3 in the extracellular culture fluids were predominant. To determine the significance of MnP3 for ligninolytic functionality in Mn2+-sufficient cultures, mnp3 was inactivated via the Δku80 strain-based P. ostreatus gene-targeting system. In Mn2+-sufficient medium, inactivation of mnp3 did not significantly affect expression of nontargeted MnPs or their genes, nor did it considerably diminish the fungal Mn2+-mediated orange II decolorization capacity, despite the significant reduction in total MnP activity. Similarly, inactivation of either mnp4 or mnp9 did not affect orange II decolorization ability. These results indicate functional redundancy within the P. ostreatus MnP gene family, enabling compensation upon deficiency of one of its members. PMID:23377936

  6. Pedestrian detection based on redundant wavelet transform

    Science.gov (United States)

    Huang, Lin; Ji, Liping; Hu, Ping; Yang, Tiejun

    2016-10-01

    Intelligent video surveillance is to analysis video or image sequences captured by a fixed or mobile surveillance camera, including moving object detection, segmentation and recognition. By using it, we can be notified immediately in an abnormal situation. Pedestrian detection plays an important role in an intelligent video surveillance system, and it is also a key technology in the field of intelligent vehicle. So pedestrian detection has very vital significance in traffic management optimization, security early warn and abnormal behavior detection. Generally, pedestrian detection can be summarized as: first to estimate moving areas; then to extract features of region of interest; finally to classify using a classifier. Redundant wavelet transform (RWT) overcomes the deficiency of shift variant of discrete wavelet transform, and it has better performance in motion estimation when compared to discrete wavelet transform. Addressing the problem of the detection of multi-pedestrian with different speed, we present an algorithm of pedestrian detection based on motion estimation using RWT, combining histogram of oriented gradients (HOG) and support vector machine (SVM). Firstly, three intensities of movement (IoM) are estimated using RWT and the corresponding areas are segmented. According to the different IoM, a region proposal (RP) is generated. Then, the features of a RP is extracted using HOG. Finally, the features are fed into a SVM trained by pedestrian databases and the final detection results are gained. Experiments show that the proposed algorithm can detect pedestrians accurately and efficiently.

  7. Redundancy among manganese peroxidases in Pleurotus ostreatus.

    Science.gov (United States)

    Salame, Tomer M; Knop, Doriv; Levinson, Dana; Yarden, Oded; Hadar, Yitzhak

    2013-04-01

    Manganese peroxidases (MnPs) are key players in the ligninolytic system of white rot fungi. In Pleurotus ostreatus (the oyster mushroom) these enzymes are encoded by a gene family comprising nine members, mnp1 to -9 (mnp genes). Mn(2+) amendment to P. ostreatus cultures results in enhanced degradation of recalcitrant compounds (such as the azo dye orange II) and lignin. In Mn(2+)-amended glucose-peptone medium, mnp3, mnp4, and mnp9 were the most highly expressed mnp genes. After 7 days of incubation, the time point at which the greatest capacity for orange II decolorization was observed, mnp3 expression and the presence of MnP3 in the extracellular culture fluids were predominant. To determine the significance of MnP3 for ligninolytic functionality in Mn(2+)-sufficient cultures, mnp3 was inactivated via the Δku80 strain-based P. ostreatus gene-targeting system. In Mn(2+)-sufficient medium, inactivation of mnp3 did not significantly affect expression of nontargeted MnPs or their genes, nor did it considerably diminish the fungal Mn(2+)-mediated orange II decolorization capacity, despite the significant reduction in total MnP activity. Similarly, inactivation of either mnp4 or mnp9 did not affect orange II decolorization ability. These results indicate functional redundancy within the P. ostreatus MnP gene family, enabling compensation upon deficiency of one of its members.

  8. Does semantic redundancy gain result from multiple semantic priming?

    Science.gov (United States)

    Schröter, Hannes; Bratzke, Daniel; Fiedler, Anja; Birngruber, Teresa

    2015-10-01

    Fiedler, Schröter, and Ulrich (2013) reported faster responses to a single written word when the semantic content of this word (e.g., "elephant") matched both targets (e.g., "animal", "gray") as compared to a single target (e.g., "animal", "brown"). This semantic redundancy gain was explained by statistical facilitation due to a race of independent memory retrieval processes. The present experiment addresses one alternative explanation, namely that semantic redundancy gain results from multiple pre-activation of words that match both targets. In different blocks of trials, participants performed a redundant-targets task and a lexical decision task. The targets of the redundant-targets task served as primes in the lexical decision task. Replicating the findings of Fiedler et al., a semantic redundancy gain was observed in the redundant-targets task. Crucially, however, there was no evidence of a multiple semantic priming effect in the lexical decision task. This result suggests that semantic redundancy gain cannot be explained by multiple pre-activation of words that match both targets. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The rid-redundant procedure in C-Prolog

    Science.gov (United States)

    Chen, Huo-Yan; Wah, Benjamin W.

    1987-01-01

    C-Prolog can conveniently be used for logical inferences on knowledge bases. However, as similar to many search methods using backward chaining, a large number of redundant computation may be produced in recursive calls. To overcome this problem, the 'rid-redundant' procedure was designed to rid all redundant computations in running multi-recursive procedures. Experimental results obtained for C-Prolog on the Vax 11/780 computer show that there is an order of magnitude improvement in the running time and solvable problem size.

  10. Redundant phenazine operons in Pseudomonas aeruginosa exhibit environment-dependent expression and differential roles in pathogenicity.

    Science.gov (United States)

    Recinos, David A; Sekedat, Matthew D; Hernandez, Adriana; Cohen, Taylor Sitarik; Sakhtah, Hassan; Prince, Alice S; Price-Whelan, Alexa; Dietrich, Lars E P

    2012-11-20

    Evolutionary biologists have postulated that several fitness advantages may be conferred by the maintenance of duplicate genes, including environmental adaptation resulting from differential regulation. We examined the expression and physiological contributions of two redundant operons in the adaptable bacterium Pseudomonas aeruginosa PA14. These operons, phzA1-G1 (phz1) and phzA2-G2 (phz2), encode nearly identical sets of proteins that catalyze the synthesis of phenazine-1-carboxylic acid, the precursor for several phenazine derivatives. Phenazines perform diverse roles in P. aeruginosa physiology and act as virulence factors during opportunistic infections of plant and animal hosts. Although reports have indicated that phz1 is regulated by the Pseudomonas quinolone signal, factors controlling phz2 expression have not been identified, and the relative contributions of these redundant operons to phenazine biosynthesis have not been evaluated. We found that in liquid cultures, phz1 was expressed at higher levels than phz2, although phz2 showed a greater contribution to phenazine production. In colony biofilms, phz2 was expressed at high levels, whereas phz1 expression was not detectable, and phz2 was responsible for virtually all phenazine production. Analysis of mutants defective in quinolone signal synthesis revealed a critical role for 4-hydroxy-2-heptylquinoline in phz2 induction. Finally, deletion of phz2, but not of phz1, decreased lung colonization in a murine model of infection. These results suggest that differential regulation of the redundant phz operons allows P. aeruginosa to adapt to diverse environments.

  11. Triple3 Redundant Spacecraft Subsystems (T3RSS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Redefine Technologies, along with researchers at the University of Colorado, will use three redundancy methods to decrease the susceptibility of a spacecraft, on a...

  12. Commentary: Non-redundant tumour suppressor functions of ...

    Indian Academy of Sciences (India)

    redundant tumour suppressor functions of transforming growth factor beta in breast cancer. Mohamad Azhar. Volume 26 Issue 1 March 2001 pp 9-12. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. Elasto-geometrical modeling and calibration of redundantly actuated PKMs

    OpenAIRE

    Ecorchard, Gaël; Neugebauer, Reimund; Maurine, Patrick

    2010-01-01

    International audience; Redundantlyactuated parallel kinematic machines (PKMs) offer a number of advantages compared to classical non-redundant PKMs. Particularly, they show a better stiffness thanks to singularity avoidance and they have an improved repeatability due to a better behavior against backlashes. The main problem with the calibration of these machines is that the redundancy leads to some mechanical strains in their structure. This makes it difficult to identify the geometrical err...

  14. Redundancy-aware topic modeling for patient record notes.

    Directory of Open Access Journals (Sweden)

    Raphael Cohen

    Full Text Available The clinical notes in a given patient record contain much redundancy, in large part due to clinicians' documentation habit of copying from previous notes in the record and pasting into a new note. Previous work has shown that this redundancy has a negative impact on the quality of text mining and topic modeling in particular. In this paper we describe a novel variant of Latent Dirichlet Allocation (LDA topic modeling, Red-LDA, which takes into account the inherent redundancy of patient records when modeling content of clinical notes. To assess the value of Red-LDA, we experiment with three baselines and our novel redundancy-aware topic modeling method: given a large collection of patient records, (i apply vanilla LDA to all documents in all input records; (ii identify and remove all redundancy by chosing a single representative document for each record as input to LDA; (iii identify and remove all redundant paragraphs in each record, leaving partial, non-redundant documents as input to LDA; and (iv apply Red-LDA to all documents in all input records. Both quantitative evaluation carried out through log-likelihood on held-out data and topic coherence of produced topics and qualitative assessment of topics carried out by physicians show that Red-LDA produces superior models to all three baseline strategies. This research contributes to the emerging field of understanding the characteristics of the electronic health record and how to account for them in the framework of data mining. The code for the two redundancy-elimination baselines and Red-LDA is made publicly available to the community.

  15. Redundant nerve roots of the cauda equina : MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Kyu Hyen; Lee, Jung Man; Jung, Hak Young; Lee, Young Hwan; Sung, Nak Kwan; Chung, Duck Soo; Kim, Ok Dong [Catholic University of Taegu-Hyosung, College of Medicine, Taegu (Korea, Republic of); Lee, Sang Kwon; Suh, Kyung Jin [Kyungbuk National Univ. College of Medicine, Taegu (Korea, Republic of)

    1997-07-01

    To evaluate MR findings of redundant nerve roots (RNR) of the cauda equina. 17 patients with RNR were studied; eight were men and nine were women, and their ages ranged from 46 to 82 (mean 63) years. Diagroses were established on the basis of T2-weighted sagittal and coronal MRI, which showed a tortuous or coiled configuration of the nerve roots of the cauda equina. MR findings were reviewed for location, magnitude, and signal intensity of redundant nerve roots, and the relationship between magnitude of redundancy and severity of lumbar spinal canal stenosis (LSCS) was evaluated. In all 17 patients, MR showed moderate or severe LSCS caused by herniation or bulging of an intervertebral disc, osteophyte from the vertebral body or facet joint, thickening of the ligamentum flavum, degenerative spondylolisthesis, or a combination of these. T2-weighted sagittal and coronal MR images well clearly showed the location of RNR of the cauda equina;in 16 patients(94%), these were seen above the level of constriction of the spinal canal, and in one case, they were observed below the level of constriction. T2-weighted axial images showed the thecal sac filled with numerous nerve roots. The magnitude of RNR was mild in six cases (35%), moderate in five cases (30%), and severe in six cases (35%). Compared with normal nerve roots, the RNR signal on T2-weighted images was iso-intense. All patients with severe redundancy showed severe LSCS, but not all cases with severe LSCS showed severe redundancy. Redundant nerve roots of cauda equina were seen in relatively older patients with moderate or severe LSCS and T2-weighted MR images were accurate in identifying redundancy of nerve roots and evaluating their magnitude and location.

  16. P2-6: Redundancy Effects on Stroop Interference

    Directory of Open Access Journals (Sweden)

    Ji Young Lee

    2012-10-01

    Full Text Available Detecting flashes of light is faster when two light stimuli appear, one in each visual fields, than when just one stimulus appears in a visual field. This ‘redundancy gain’ phenomenon shows the cooperation of redundant signals for common task goal. Then, what if they are in the context of competition? Two perceptually identical objects might compete with each other as much as two different objects of a category. Alternatively, they might cooperate to form a stable, veridical representation. These conflicting possibilities were tested with three behavioral experiments. Experiment 1 and 2 used a name-picture Stroop task. In each trial, participants categorized a famous target name into that of an actor or a sports player while ignoring a flanking famous face distractor, which could be either congruent (e.g., an actor's name and face or incongruent (e.g., an actor's name and a player's face. In redundancy condition, the same face was added in the opposite side of the face distractor. As results, relative to a single distractor, Stroop interference was enhanced by two perceptually identical distractors. Importantly, this redundancy effect disappeared when two faces were the same at the response level, but different at the perceptual level. This effect was replicated with nonface objects in Experiment 3, which further showed that redundancy effect was not affected by time differential display of identical distractors. Overall, current study found a phenomenon of ‘redundancy loss’ and suggests that redundant presentation of a stimulus overcome attentional constraints by facilitating perceptual processing.

  17. The cellular robustness by genetic redundancy in budding yeast.

    Directory of Open Access Journals (Sweden)

    Jingjing Li

    2010-11-01

    Full Text Available The frequent dispensability of duplicated genes in budding yeast is heralded as a hallmark of genetic robustness contributed by genetic redundancy. However, theoretical predictions suggest such backup by redundancy is evolutionarily unstable, and the extent of genetic robustness contributed from redundancy remains controversial. It is anticipated that, to achieve mutual buffering, the duplicated paralogs must at least share some functional overlap. However, counter-intuitively, several recent studies reported little functional redundancy between these buffering duplicates. The large yeast genetic interactions released recently allowed us to address these issues on a genome-wide scale. We herein characterized the synthetic genetic interactions for ∼500 pairs of yeast duplicated genes originated from either whole-genome duplication (WGD or small-scale duplication (SSD events. We established that functional redundancy between duplicates is a pre-requisite and thus is highly predictive of their backup capacity. This observation was particularly pronounced with the use of a newly introduced metric in scoring functional overlap between paralogs on the basis of gene ontology annotations. Even though mutual buffering was observed to be prevalent among duplicated genes, we showed that the observed backup capacity is largely an evolutionarily transient state. The loss of backup capacity generally follows a neutral mode, with the buffering strength decreasing in proportion to divergence time, and the vast majority of the paralogs have already lost their backup capacity. These observations validated previous theoretic predictions about instability of genetic redundancy. However, departing from the general neutral mode, intriguingly, our analysis revealed the presence of natural selection in stabilizing functional overlap between SSD pairs. These selected pairs, both WGD and SSD, tend to have decelerated functional evolution, have higher propensities of co

  18. Path-planning editor for kinematically redundant robots

    Science.gov (United States)

    Das, Hari; Lee, Sukhan

    1993-03-01

    A computer aid is proposed in this paper for planning paths for redundant robots. The aid, called a Path Planning Editor (PPE), allows a user to specify the complete configuration for a redundant robot over a desired path. Powerful visualization features in the PPE help the user make decisions on configuration selection for the robot. Visualization is offered not only of the robot motion but also of the optimization criterion function plotted over the redundant space. A demonstration of these ideas has been implemented using two graphic workstations for 3-D visualization and a third computer for the user interface designed using the X Window system. The robot chosen for the application is the 8 degrees of freedom AAI robot used in the Advanced Teleoperation Laboratory of JPL. Details of the implementation are described and suggestions are made for improvement of the PPE in this paper.

  19. Program management aid for redundancy selection and operational guidelines

    Science.gov (United States)

    Hodge, P. W.; Davis, W. L.; Frumkin, B.

    1972-01-01

    Although this criterion was developed specifically for use on the shuttle program, it has application to many other multi-missions programs (i.e. aircraft or mechanisms). The methodology employed is directly applicable even if the tools (nomographs and equations) are for mission peculiar cases. The redundancy selection criterion was developed to insure that both the design and operational cost impacts (life cycle costs) were considered in the selection of the quantity of operational redundancy. These tools were developed as aids in expediting the decision process and not intended as the automatic decision maker. This approach to redundancy selection is unique in that it enables a pseudo systems analysis to be performed on an equipment basis without waiting for all designs to be hardened.

  20. Repetitive motion planning and control of redundant robot manipulators

    CERN Document Server

    Zhang, Yunong

    2013-01-01

    Repetitive Motion Planning and Control of Redundant Robot Manipulators presents four typical motion planning schemes based on optimization techniques, including the fundamental RMP scheme and its extensions. These schemes are unified as quadratic programs (QPs), which are solved by neural networks or numerical algorithms. The RMP schemes are demonstrated effectively by the simulation results based on various robotic models; the experiments applying the fundamental RMP scheme to a physical robot manipulator are also presented. As the schemes and the corresponding solvers presented in the book have solved the non-repetitive motion problems existing in redundant robot manipulators, it is of particular use in applying theoretical research based on the quadratic program for redundant robot manipulators in industrial situations. This book will be a valuable reference work for engineers, researchers, advanced undergraduate and graduate students in robotics fields. Yunong Zhang is a professor at The School of Informa...

  1. The redundant target effect is affected by modality switch costs

    DEFF Research Database (Denmark)

    Gondan, Matthias; Lange, K.; Rösler, F.

    2004-01-01

    When participants have to respond to stimuli of two modalities, faster reaction times are observed for simultaneous, bimodal events than for unimodal events (the redundant target effect [RTE]). This finding has been interpreted as reflecting processing gains for bimodal relative to unimodal stimuli......, possibly due to multisensory interactions. In random stimulus sequences, reaction times are slower when the stimulus is preceded by a stimulus of a different modality (modality switch effect [MSE]). Simple reaction time redundant target experiments with auditory-visual, visual-tactile, and auditory...... for the MSE, supporting the hypothesis that coactivation occurs independently of modality switch costs....

  2. Redundant information from thermal illumination: quantum Darwinism in scattered photons

    Energy Technology Data Exchange (ETDEWEB)

    Jess Riedel, C; Zurek, Wojciech H, E-mail: criedel@physics.ucsb.edu [Theory Division, LANL, Los Alamos, NM 87545 (United States)

    2011-07-15

    We study quantum Darwinism, the redundant recording of information about the preferred states of a decohering system by its environment, for an object illuminated by a blackbody. We calculate the quantum mutual information between the object and its photon environment for blackbodies that cover an arbitrary section of the sky. In particular, we demonstrate that more extended sources have a reduced ability to create redundant information about the system, in agreement with previous evidence that initial mixedness of an environment slows-but does not stop-the production of records. We also show that the qualitative results are robust for more general initial states of the system.

  3. Redundant information from thermal illumination: quantum Darwinism in scattered photons

    Science.gov (United States)

    Jess Riedel, C.; Zurek, Wojciech H.

    2011-07-01

    We study quantum Darwinism, the redundant recording of information about the preferred states of a decohering system by its environment, for an object illuminated by a blackbody. We calculate the quantum mutual information between the object and its photon environment for blackbodies that cover an arbitrary section of the sky. In particular, we demonstrate that more extended sources have a reduced ability to create redundant information about the system, in agreement with previous evidence that initial mixedness of an environment slows—but does not stop—the production of records. We also show that the qualitative results are robust for more general initial states of the system.

  4. Information filtering based on corrected redundancy-eliminating mass diffusion.

    Science.gov (United States)

    Zhu, Xuzhen; Yang, Yujie; Chen, Guilin; Medo, Matus; Tian, Hui; Cai, Shi-Min

    2017-01-01

    Methods used in information filtering and recommendation often rely on quantifying the similarity between objects or users. The used similarity metrics often suffer from similarity redundancies arising from correlations between objects' attributes. Based on an unweighted undirected object-user bipartite network, we propose a Corrected Redundancy-Eliminating similarity index (CRE) which is based on a spreading process on the network. Extensive experiments on three benchmark data sets-Movilens, Netflix and Amazon-show that when used in recommendation, the CRE yields significant improvements in terms of recommendation accuracy and diversity. A detailed analysis is presented to unveil the origins of the observed differences between the CRE and mainstream similarity indices.

  5. A Cause-Consequence Chart of a Redundant Protection System

    DEFF Research Database (Denmark)

    Nielsen, Dan Sandvik; Platz, O.; Runge, B.

    1975-01-01

    A cause-consequence chart is applied in analysing failures of a redundant protection system (a core spray system in a nuclear power plant). It is shown how the diagram provides a basis for calculating two probability measures for malfunctioning of the protection system. The test policy of compone......A cause-consequence chart is applied in analysing failures of a redundant protection system (a core spray system in a nuclear power plant). It is shown how the diagram provides a basis for calculating two probability measures for malfunctioning of the protection system. The test policy...

  6. A Comparison of Routing Protocol for WSNs: Redundancy Based Approach A Comparison of Routing Protocol for WSNs: Redundancy Based Approach

    Directory of Open Access Journals (Sweden)

    Anand Prakash

    2014-03-01

    Full Text Available Wireless Sensor Networks (WSNs with their dynamic applications gained a tremendous attention of researchers. Constant monitoring of critical situations attracted researchers to utilize WSNs at vast platforms. The main focus in WSNs is to enhance network localization as much as one could, for efficient and optimal utilization of resources. Different approaches based upon redundancy are proposed for optimum functionality. Localization is always related with redundancy of sensor nodes deployed at remote areas for constant and fault tolerant monitoring. In this work, we propose a comparison of classic flooding and the gossip protocol for homogenous networks which enhances stability and throughput quiet significantly.  

  7. The bliss (not the problem) of motor abundance (not redundancy).

    Science.gov (United States)

    Latash, Mark L

    2012-03-01

    Motor control is an area of natural science exploring how the nervous system interacts with other body parts and the environment to produce purposeful, coordinated actions. A central problem of motor control-the problem of motor redundancy-was formulated by Nikolai Bernstein as the problem of elimination of redundant degrees-of-freedom. Traditionally, this problem has been addressed using optimization methods based on a variety of cost functions. This review draws attention to a body of recent findings suggesting that the problem has been formulated incorrectly. An alternative view has been suggested as the principle of abundance, which considers the apparently redundant degrees-of-freedom as useful and even vital for many aspects of motor behavior. Over the past 10 years, dozens of publications have provided support for this view based on the ideas of synergic control, computational apparatus of the uncontrolled manifold hypothesis, and the equilibrium-point (referent configuration) hypothesis. In particular, large amounts of "good variance"-variance in the space of elements that has no effect on the overall performance-have been documented across a variety of natural actions. "Good variance" helps an abundant system to deal with secondary tasks and unexpected perturbations; its amount shows adaptive modulation across a variety of conditions. These data support the view that there is no problem of motor redundancy; there is bliss of motor abundance.

  8. Redundancy and Novelty Mining in the Business Blogosphere

    Science.gov (United States)

    Tsai, Flora S.; Chan, Kap Luk

    2010-01-01

    Purpose: The paper aims to explore the performance of redundancy and novelty mining in the business blogosphere, which has not been studied before. Design/methodology/approach: Novelty mining techniques are implemented to single out novel information out of a massive set of text documents. This paper adopted the mixed metric approach which…

  9. Controlling Split Attention and Redundancy in Physical Therapy Instruction

    Science.gov (United States)

    Pociask, Fredrick D.; Morrison, Gary R.

    2008-01-01

    In this study, we examined the effectiveness of instructional materials designed to control redundancy and split attention in the teaching of complex orthopedic physical therapy skills. Participants included 41 first-year physical therapy students. The modified instruction group received a modified unit of instruction designed to reduce cognitive…

  10. Exploiting network redundancy for low-cost neural network realizations.

    NARCIS (Netherlands)

    Keegstra, H; Jansen, WJ; Nijhuis, JAG; Spaanenburg, L; Stevens, H; Udding, JT

    1996-01-01

    A method is presented to optimize a trained neural network for physical realization styles. Target architectures are embedded microcontrollers or standard cell based ASIC designs. The approach exploits the redundancy in the network, required for successful training, to replace the synaptic weighting

  11. Virtual Modular Redundancy of Processor Module in the PLC

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang-Il; Hwang, SungJae; Yoon, DongHwa [SOOSAN ENS Co., Seoul (Korea, Republic of)

    2016-10-15

    Dual Modular Redundancy (DMR) is mainly used to implement these safety control systems. DMR is conveyed when components of a system are duplicated, providing another component in case one should fault or fail. This feature has a high availability and large fault tolerant. It provides zero downtime that is required for nuclear power plants. So nuclear power plant has been commercialized by multiple redundant systems. The following paper, we propose a Virtual Modular Redundancy (VMR) rather than physical triple of the Programmable Logic Controller (PLC) processor module to ensure the reliability of the nuclear power plant control system. VMR implementation minimizes design changes to continue to use the commercially available redundant system. Also, the purpose of the VMR is to improve the efficiency and reliability in many ways, such as fault tolerant and fail-safe and cost. VMR guarantees a wide range of reliable fault recovery, fault tolerance, etc. It is prevented before it causes great damages due to the continuous failure of the two modules. The reliable communication speed is slow and also it has a small bandwidth. It is a great loss in the safety control system. However, VMR aims to avoid nuclear power plants that were suspended due to fail-safe. It is not for the purpose of commonly used. Application of VMR is actually expected to require a lot of research and trial and error until they adapt to the nuclear regulatory and standards.

  12. Redundancies in Hydro Reservoir Elements and their Contributions ...

    African Journals Online (AJOL)

    Despite the over 100 years of electricity in Nigeria, power generation is still largely lagging behind its demand as all the hydro dams are still performing below installed capacities. The purpose of this paper is to expose the rates of redundancies in the contributions of reservoir elements to power generation in Jebba dam and ...

  13. Quantifying the value of redundant measurements at GRUAN sites

    Science.gov (United States)

    Madonna, F.; Rosoldi, M.; Güldner, J.; Haefele, A.; Kivi, R.; Cadeddu, M. P.; Sisterson, D.; Pappalardo, G.

    2014-06-01

    The potential for measurement redundancy to reduce uncertainty in atmospheric variables has not been investigated comprehensively for climate observations. We evaluated the usefulness of entropy and mutual correlation concepts, as defined in information theory, for quantifying random uncertainty and redundancy in time series of atmospheric water vapor provided by five highly instrumented GRUAN (GCOS [Global Climate Observing System] Reference Upper-Air Network) Stations in 2010-2012. Results show that the random uncertainties for radiosonde, frost-point hygrometer, Global Positioning System, microwave and infrared radiometers, and Raman lidar measurements differed by less than 8%. Comparisons of time series of the Integrated Water Vapor (IWV) content from ground-based remote sensing instruments with in situ soundings showed that microwave radiometers have the highest redundancy and therefore the highest potential to reduce random uncertainty of IWV time series estimated by radiosondes. Moreover, the random uncertainty of a time series from one instrument should be reduced of ~ 60% by constraining the measurements with those from another instrument. The best reduction of random uncertainty resulted from conditioning of Raman lidar measurements with microwave radiometer measurements. Specific instruments are recommended for atmospheric water vapor measurements at GRUAN sites. This approach can be applied to the study of redundant measurements for other climate variables.

  14. DISTRIBUTION OF FRAGMENTED FRAMES OVER REDUNDANT CHANNELS OF COMPUTER NETWORK

    Directory of Open Access Journals (Sweden)

    A. V. Osipov

    2013-03-01

    Full Text Available Algorithm of frames distribution over redundant heterogeneous channels, taking into account the physical characteristics of channels is proposed. Simulation model of the algorithm based on MATLAB / Simulink confirms the advantages of the algorithm as compared to RoundRobin and RateBalace algorithms.

  15. DISTRIBUTION OF FRAGMENTED FRAMES OVER REDUNDANT CHANNELS OF COMPUTER NETWORK

    OpenAIRE

    Osipov, A. V.

    2013-01-01

    Algorithm of frames distribution over redundant heterogeneous channels, taking into account the physical characteristics of channels is proposed. Simulation model of the algorithm based on MATLAB / Simulink confirms the advantages of the algorithm as compared to RoundRobin and RateBalace algorithms.

  16. Mediated Instruction and Redundancy Remediation in Sciences in ...

    African Journals Online (AJOL)

    A computer designed instruction on circulatory system developed on power point projection was used in treating the experimental group, while the expository pedagogical strategy was used to teach the control groups on the same lesson. Redundancy remediation achievement test (RRAT) was developed to test the ability ...

  17. Key herbivores reveal limited functional redundancy on inshore coral reefs

    NARCIS (Netherlands)

    Johansson, C.L.; Leemput, van de I.A.; Depczynski, M.; Hoey, A.S.; Bellwood, D.R.

    2013-01-01

    Marine ecosystems are facing increasing exposure to a range of stressors and declines in critical ecological functions. The likelihood of further loss of functions and resilience is dependent, in part, on the extent of functional redundancy (i.e. the capacity of one species to functionally

  18. Testing the significance of canonical axes in redundancy analysis

    NARCIS (Netherlands)

    Legendre, P.; Oksanen, J.; Braak, ter C.J.F.

    2011-01-01

    1. Tests of significance of the individual canonical axes in redundancy analysis allow researchers to determine which of the axes represent variation that can be distinguished from random. Variation along the significant axes can be mapped, used to draw biplots or interpreted through subsequent

  19. Redundancy Effect on Retention of Vocabulary Words Using Multimedia Presentation

    Science.gov (United States)

    Samur, Yavuz

    2012-01-01

    This study was designed to examine the effect of the redundancy principle in a multimedia presentation constructed for foreign language vocabulary learning on undergraduate students' retention. The underlying hypothesis of this study is that when the students are exposed to the material in multiple ways through animation, concurrent narration,…

  20. Factors associated with redundant sigmoid colon at Mulago Hospital ...

    African Journals Online (AJOL)

    Background: Sigmoid Volvulus is the most common form of Volvulus of the gastrointestinal tract and in Uganda; this condition is one of the top causes of intestinal obstruction. It is associated with a pre-existing redundant sigmoid colon which has a narrow attachment of the sigmoid mesentery to the posterior abdominal wall.

  1. Factors Associated with Redundant Sigmoid Colon at Mulago ...

    African Journals Online (AJOL)

    jen

    Background: Sigmoid Volvulus is the most common form of Volvulus of the gastrointestinal tract and in Uganda; this condition is one of the top causes of intestinal obstruction. It is associated with a pre-existing redundant sigmoid colon which has a narrow attachment of the sigmoid mesentery to the posterior abdominal wall.

  2. Optimal cognitive transmission exploiting redundancy in the primary ARQ process

    DEFF Research Database (Denmark)

    Michelusi, Nicholo; Simeone, Osvaldo; Levorato, Marco

    2011-01-01

    transmissions to the SU. We investigate secondary transmission policies that take advantage of this redundancy. The basic idea is that, if a Secondary Receiver (SR) learns the Primary Message (PM) in a given primary retransmission, then it can use this knowledge to cancel the primary interference...

  3. 71 Network Gateway Technology: The Issue of Redundancy towards ...

    African Journals Online (AJOL)

    User

    2012-01-24

    Jan 24, 2012 ... is an open source standard. The major network devices used in network gateway redundancy configuration are the routers and multilayer switches. They are used as active and backup devices depending on the type of network topology. Whenever the active gateway fails, in the event of hardware failure,.

  4. Network Gateway Technology: The Issue of Redundancy towards ...

    African Journals Online (AJOL)

    The Internet has provided advancement in the areas of network and networking facilities. Everyone connected to the Internet is concerned about two basic things: the availability of network services and the speed of the network. Network gateway redundancy technology falls within these categories and happens to be one of ...

  5. Reducing Verbal Redundancy in Multimedia Learning: An Undesired Desirable Difficulty?

    Science.gov (United States)

    Yue, Carole L.; Bjork, Elizabeth Ligon; Bjork, Robert A.

    2013-01-01

    Previous research on the redundancy principle in multimedia learning has shown that although exact correspondence between on-screen text and narration generally impairs learning, brief labels within an animation can improve learning. To clarify and extend the theoretical and practical implications of these results, the authors of the present…

  6. GO Trimming: Systematically reducing redundancy in large Gene Ontology datasets

    Directory of Open Access Journals (Sweden)

    Koop Ben F

    2011-07-01

    Full Text Available Abstract Background The increased accessibility of gene expression tools has enabled a wide variety of experiments utilizing transcriptomic analyses. As these tools increase in prevalence, the need for improved standardization in processing and presentation of data increases, as does the need to guard against interpretation bias. Gene Ontology (GO analysis is a powerful method of interpreting and summarizing biological functions. However, while there are many tools available to investigate GO enrichment, there remains a need for methods that directly remove redundant terms from enriched GO lists that often provide little, if any, additional information. Findings Here we present a simple yet novel method called GO Trimming that utilizes an algorithm designed to reduce redundancy in lists of enriched GO categories. Depending on the needs of the user, this method can be performed with variable stringency. In the example presented here, an initial list of 90 terms was reduced to 54, eliminating 36 largely redundant terms. We also compare this method to existing methods and find that GO Trimming, while simple, performs well to eliminate redundant terms in a large dataset throughout the depth of the GO hierarchy. Conclusions The GO Trimming method provides an alternative to other procedures, some of which involve removing large numbers of terms prior to enrichment analysis. This method should free up the researcher from analyzing overly large, redundant lists, and instead enable the concise presentation of manageable, informative GO lists. The implementation of this tool is freely available at: http://lucy.ceh.uvic.ca/go_trimming/cbr_go_trimming.py

  7. SIMULATION MODEL FOR DESIGN SUPPORT OF INFOCOMM REDUNDANT SYSTEMS

    Directory of Open Access Journals (Sweden)

    V. A. Bogatyrev

    2016-09-01

    Full Text Available Subject of Research. The paper deals with the effectiveness of multipath transfer of request copies through the network and their redundant service without the use of laborious analytical modeling. The model and support tools for the design of highly reliable distributed systems based on simulation modeling have been created. Method. The effectiveness of many variants of service organization and delivery through the network to the query servers is formed and analyzed. Options for providing redundant service and delivery via the network to the servers of request copies are also considered. The choice of variants for the distribution and service of requests is carried out taking into account the criticality of queries to the time of their stay in the system. The request is considered successful if at least one of its copies is accurately delivered to the working server, ready to service the request received through a network, if it is fulfilled in the set time. Efficiency analysis of the redundant transmission and service of requests is based on the model built in AnyLogic 7 simulation environment. Main Results. Simulation experiments based on the proposed models have shown the effectiveness of redundant transmission of copies of queries (packets to the servers in the cluster through multiple paths with redundant service of request copies by a group of servers in the cluster. It is shown that this solution allows increasing the probability of exact execution of at least one copy of the request within the required time. We have carried out efficiency evaluation of destruction of outdated request copies in the queues of network nodes and the cluster. We have analyzed options for network implementation of multipath transfer of request copies to the servers in the cluster over disjoint paths, possibly different according to the number of their constituent nodes. Practical Relevance. The proposed simulation models can be used when selecting the optimal

  8. The Birth and Death of Redundancy in Decoherence and Quantum Darwinism

    Science.gov (United States)

    Riedel, Charles; Zurek, Wojciech; Zwolak, Michael

    2012-02-01

    Understanding the quantum-classical transition and the identification of a preferred classical domain through quantum Darwinism is based on recognizing high-redundancy states as both ubiquitous and exceptional. They are produced ubiquitously during decoherence, as has been demonstrated by the recent identification of very general conditions under which high-redundancy states develop. They are exceptional in that high-redundancy states occupy a very narrow corner of the global Hilbert space; states selected at random are overwelming likely to exhibit zero redundancy. In this letter, we examine the conditions and time scales for the transition from high-redundancy states to zero-redundancy states in many-body dynamics. We identify sufficient condition for the development of redundancy from product states and show that the destruction of redundancy can be accomplished even with highly constrained interactions.

  9. Susceptibility of Redundant Versus Singular Clock Domains Implemented in SRAM-Based FPGA TMR Designs

    Science.gov (United States)

    Berg, Melanie D.; LaBel, Kenneth A.; Pellish, Jonathan

    2016-01-01

    We present the challenges that arise when using redundant clock domains due to their clock-skew. Radiation data show that a singular clock domain (DTMR) provides an improved TMR methodology for SRAM-based FPGAs over redundant clocks.

  10. Information theory and artificial grammar learning: inferring grammaticality from redundancy.

    Science.gov (United States)

    Jamieson, Randall K; Nevzorova, Uliana; Lee, Graham; Mewhort, D J K

    2016-03-01

    In artificial grammar learning experiments, participants study strings of letters constructed using a grammar and then sort novel grammatical test exemplars from novel ungrammatical ones. The ability to distinguish grammatical from ungrammatical strings is often taken as evidence that the participants have induced the rules of the grammar. We show that judgements of grammaticality are predicted by the local redundancy of the test strings, not by grammaticality itself. The prediction holds in a transfer test in which test strings involve different letters than the training strings. Local redundancy is usually confounded with grammaticality in stimuli widely used in the literature. The confounding explains why the ability to distinguish grammatical from ungrammatical strings has popularized the idea that participants have induced the rules of the grammar, when they have not. We discuss the judgement of grammaticality task in terms of attribute substitution and pattern goodness. When asked to judge grammaticality (an inaccessible attribute), participants answer an easier question about pattern goodness (an accessible attribute).

  11. Information filtering based on corrected redundancy-eliminating mass diffusion.

    Directory of Open Access Journals (Sweden)

    Xuzhen Zhu

    Full Text Available Methods used in information filtering and recommendation often rely on quantifying the similarity between objects or users. The used similarity metrics often suffer from similarity redundancies arising from correlations between objects' attributes. Based on an unweighted undirected object-user bipartite network, we propose a Corrected Redundancy-Eliminating similarity index (CRE which is based on a spreading process on the network. Extensive experiments on three benchmark data sets-Movilens, Netflix and Amazon-show that when used in recommendation, the CRE yields significant improvements in terms of recommendation accuracy and diversity. A detailed analysis is presented to unveil the origins of the observed differences between the CRE and mainstream similarity indices.

  12. Computer Aided Design of a Hyper-redundant Manipulator

    Directory of Open Access Journals (Sweden)

    MARGHITU, D.

    2013-11-01

    Full Text Available Bioinspired solution can support significant improvements across various fields of robotics, offering solutions to basic problems such as locomotion and manipulation in unstructured environments. This paper deals with the problem of using a bioinspired solution in building a hyper-redundant robotic arm. In the recent period, were developed an important number of application using like an octopus or like snake or like a trunk of elephant solutions for robotic arms. Such kind of projects must solve difficult problems on the way from design to implementation. The problems are mainly linked with the actuation solution, with the control of the structure, with sensors to close the control loop, technology for the implementation. In this paper we focus on the process of modelling, simulating, and designing of hyper-redundant robotic arm.

  13. Information filtering based on corrected redundancy-eliminating mass diffusion

    Science.gov (United States)

    Zhu, Xuzhen; Yang, Yujie; Chen, Guilin; Medo, Matus; Tian, Hui

    2017-01-01

    Methods used in information filtering and recommendation often rely on quantifying the similarity between objects or users. The used similarity metrics often suffer from similarity redundancies arising from correlations between objects’ attributes. Based on an unweighted undirected object-user bipartite network, we propose a Corrected Redundancy-Eliminating similarity index (CRE) which is based on a spreading process on the network. Extensive experiments on three benchmark data sets—Movilens, Netflix and Amazon—show that when used in recommendation, the CRE yields significant improvements in terms of recommendation accuracy and diversity. A detailed analysis is presented to unveil the origins of the observed differences between the CRE and mainstream similarity indices. PMID:28749976

  14. Using Negotiation to Reduce Redundant Autonomous Mobile Program Movements

    OpenAIRE

    Chechina, N.; King, P.; Trinder, P. W.

    2010-01-01

    Distributed load managers exhibit thrashing where tasks are repeatedly moved between locations due to incomplete global load information. This paper shows that systems of Autonomous Mobile Programs (AMPs) exhibit the same behaviour, identifying two types of redundant movement and terming them greedy effects. AMPs are unusual in that, in place of some external load management system, each AMP periodically recalculates network and program parameters and may independently move to a better execut...

  15. Knowledge Sharing in Construction Partnering - Redundancy, Boundary Objects and Brokers

    DEFF Research Database (Denmark)

    Koch, Christian; Thuesen, Christian Langhoff

    2013-01-01

    , multiple memberships and different levels of participation, and accompanied by a governance frame. The paper discusses central mechanisms for coordinating knowledge in such a complex construction project. The knowledge relations are conceptualized through focusing on redundancy, understood as negotiated...... dialogue excerpts, one on process, and one on product knowledge exchanges. The diversity and disjunctive feature of the practices form a condition of possibility for knowledge handling and synthesis into the built construct. Relation-based interaction is necessary with boundary objects and brokers...

  16. On Planning of FTTH Access Networks with and without Redundancy

    DEFF Research Database (Denmark)

    Riaz, M. Tahir; Haraldsson, Gustav; Gutierrez Lopez, Jose Manuel

    2010-01-01

    offered on a single fiber connection. As a single point of failure in fiber connection can cause multiple service deprivation therefore redundancy is very crucial. In this work, an automated planning model was used to test different scenarios of implementation. A cost estimation is presented in terms...... of digging and amount of fiber used. Three topologies, including the traditional one “tree topology”, were test with combination of various passive optical technologies....

  17. Redundancy and the evolution of cis-regulatory element multiplicity.

    Directory of Open Access Journals (Sweden)

    Tiago Paixão

    Full Text Available The promoter regions of many genes contain multiple binding sites for the same transcription factor (TF. One possibility is that this multiplicity evolved through transitional forms showing redundant cis-regulation. To evaluate this hypothesis, we must disentangle the relative contributions of different evolutionary mechanisms to the evolution of binding site multiplicity. Here, we attempt to do this using a model of binding site evolution. Our model considers binding sequences and their interactions with TFs explicitly, and allows us to cast the evolution of gene networks into a neutral network framework. We then test some of the model's predictions using data from yeast. Analysis of the model suggested three candidate nonadaptive processes favoring the evolution of cis-regulatory element redundancy and multiplicity: neutral evolution in long promoters, recombination and TF promiscuity. We find that recombination rate is positively associated with binding site multiplicity in yeast. Our model also indicated that weak direct selection for multiplicity (partial redundancy can play a major role in organisms with large populations. Our data suggest that selection for changes in gene expression level may have contributed to the evolution of multiple binding sites in yeast. We conclude that the evolution of cis-regulatory element redundancy and multiplicity is impacted by many aspects of the biology of an organism: both adaptive and nonadaptive processes, both changes in cis to binding sites and in trans to the TFs that interact with them, both the functional setting of the promoter and the population genetic context of the individuals carrying them.

  18. Identifying redundancy and exposing provenance in crowdsourced data analysis.

    Science.gov (United States)

    Willett, Wesley; Ginosar, Shiry; Steinitz, Avital; Hartmann, Björn; Agrawala, Maneesh

    2013-12-01

    We present a system that lets analysts use paid crowd workers to explore data sets and helps analysts interactively examine and build upon workers' insights. We take advantage of the fact that, for many types of data, independent crowd workers can readily perform basic analysis tasks like examining views and generating explanations for trends and patterns. However, workers operating in parallel can often generate redundant explanations. Moreover, because workers have different competencies and domain knowledge, some responses are likely to be more plausible than others. To efficiently utilize the crowd's work, analysts must be able to quickly identify and consolidate redundant responses and determine which explanations are the most plausible. In this paper, we demonstrate several crowd-assisted techniques to help analysts make better use of crowdsourced explanations: (1) We explore crowd-assisted strategies that utilize multiple workers to detect redundant explanations. We introduce color clustering with representative selection--a strategy in which multiple workers cluster explanations and we automatically select the most-representative result--and show that it generates clusterings that are as good as those produced by experts. (2) We capture explanation provenance by introducing highlighting tasks and capturing workers' browsing behavior via an embedded web browser, and refine that provenance information via source-review tasks. We expose this information in an explanation-management interface that allows analysts to interactively filter and sort responses, select the most plausible explanations, and decide which to explore further.

  19. In vivo analysis of Lrig genes reveals redundant and independent functions in the inner ear.

    Directory of Open Access Journals (Sweden)

    Tony Del Rio

    Full Text Available Lrig proteins are conserved transmembrane proteins that modulate a variety of signaling pathways from worm to humans. In mammals, there are three family members - Lrig1, Lrig2, and Lrig3--that are defined by closely related extracellular domains with a similar arrangement of leucine rich repeats and immunoglobulin domains. However, the intracellular domains show little homology. Lrig1 inhibits EGF signaling through internalization and degradation of ErbB receptors. Although Lrig3 can also bind ErbB receptors in vitro, it is unclear whether Lrig2 and Lrig3 exhibit similar functions to Lrig1. To gain insights into Lrig gene functions in vivo, we compared the expression and function of the Lrigs in the inner ear, which offers a sensitive system for detecting effects on morphogenesis and function. We find that all three family members are expressed in the inner ear throughout development, with Lrig1 and Lrig3 restricted to subsets of cells and Lrig2 expressed more broadly. Lrig1 and Lrig3 overlap prominently in the developing vestibular apparatus and simultaneous removal of both genes disrupts inner ear morphogenesis. This suggests that these two family members act redundantly in the otic epithelium. In contrast, although Lrig1 and Lrig2 are frequently co-expressed, Lrig1(-/-;Lrig2(-/- double mutant ears show no enhanced structural abnormalities. At later stages, Lrig1 expression is sustained in non-sensory tissues, whereas Lrig2 levels are enhanced in neurons and sensory epithelia. Consistent with these distinct expression patterns, Lrig1 and Lrig2 mutant mice exhibit different forms of impaired auditory responsiveness. Notably, Lrig1(-/-;Lrig2(-/- double mutant mice display vestibular deficits and suffer from a more severe auditory defect that is accompanied by a cochlear innervation phenotype not present in single mutants. Thus, Lrig genes appear to act both redundantly and independently, with Lrig2 emerging as the most functionally distinct

  20. Evaluation of Redundancy for Power Generating Unit in a Cogeneration Power Plant

    Directory of Open Access Journals (Sweden)

    Reshid Meseret Nasir

    2014-07-01

    Full Text Available Redundancy system is very useful to enhance the performance and reliability of the power generation system of a cogeneration plant. However, the associated operating cost of redundancy system is very high. The common redundancies used in a cogeneration power plant are public utility and generator set. In order to select the best redundancy options which incurs minimum operating cost, it is required to evaluate the cost of different redundancy options. In this paper, net present value model (NPV is developed to evaluate the cost of redundancy considering availability and reliability of the cogeneration system. Two steps applied to evaluate the redundancy cost of the cogeneration system. The first step is predicting the number of failures and downtime hours using availability and reliability analysis because redundancy is frequently used when the system failed. The second step is evaluating the cost of redundancy using NPV model. The results indicate that the use of public utility as redundancy option is costly compared to generator set option for long period of time. The major operation cost of public utility is contributed by the maximum demand charge cost which is about 57.9% of the total cost of redundancy. The study will be useful as a guide for the cogeneration operation to evaluate and select the redundancy option.

  1. Redundancy and specialization among plant microRNAs: role of the MIR164 family in developmental robustness.

    Science.gov (United States)

    Sieber, Patrick; Wellmer, Frank; Gheyselinck, Jacqueline; Riechmann, José Luis; Meyerowitz, Elliot M

    2007-03-01

    In plants, members of microRNA (miRNA) families are often predicted to target the same or overlapping sets of genes. It has thus been hypothesized that these miRNAs may act in a functionally redundant manner. This hypothesis is tested here by studying the effects of elimination of all three members of the MIR164 family from Arabidopsis. It was found that a loss of miR164 activity leads to a severe disruption of shoot development, in contrast to the effect of mutation in any single MIR164 gene. This indicates that these miRNAs are indeed functionally redundant. Differences in the expression patterns of the individual MIR164 genes imply, however, that redundancy among them is not complete, and that these miRNAs show functional specialization. Furthermore, the results of molecular and genetic analyses of miR164-mediated target regulation indicate that miR164 miRNAs function to control the transcript levels, as well as the expression patterns, of their targets, suggesting that they might contribute to developmental robustness. For two of the miR164 targets, namely CUP-SHAPED COTYLEDON1 (CUC1) and CUC2, we provide evidence for their involvement in the regulation of growth and show that their derepression in miR164 loss-of-function mutants is likely to account for most of the mutant phenotype.

  2. Quantum Darwinism: Entanglement, branches, and the emergent classicality of redundantly stored quantum information

    Science.gov (United States)

    Blume-Kohout, Robin; Zurek, Wojciech H.

    2006-06-01

    We lay a comprehensive foundation for the study of redundant information storage in decoherence processes. Redundancy has been proposed as a prerequisite for objectivity, the defining property of classical objects. We consider two ensembles of states for a model universe consisting of one system and many environments: the first consisting of arbitrary states, and the second consisting of “singly branching” states consistent with a simple decoherence model. Typical states from the random ensemble do not store information about the system redundantly, but information stored in branching states has a redundancy proportional to the environment’s size. We compute the specific redundancy for a wide range of model universes, and fit the results to a simple first-principles theory. Our results show that the presence of redundancy divides information about the system into three parts: classical (redundant); purely quantum; and the borderline, undifferentiated or “nonredundant,” information.

  3. Performance Evaluation of Redundant Parallel Manipulators Assimilating Motion/Force Transmissibility

    Directory of Open Access Journals (Sweden)

    Fugui Xie

    2011-11-01

    Full Text Available Performance evaluation is one of the most important issues in the field of parallel kinematic manipulators (PKMs. As a very important class of PKMs, the redundant PKMs have been studied intensively. However, the performance evaluation of this type of PKMs is still unresolved and a challenging endeavor. In this paper, indices that assimilate motion/force transmissibility are proposed to evaluate the performance of redundant PKMs. To illustrate the application of these indices, three PKMs with different kinds of redundancies are taken as examples, and performance atlases are plotted based on the definitions of the indices. Transmissibility comparisons between redundant PKMs and the corresponding non-redundant ones are carried out. To determine the inverse solutions of the PKMs with kinematic redundancy, an optimization strategy is presented, and the rationality of this method is demonstrated. The indices introduced here can be applied to the performance evaluation of redundant parallel manipulators.

  4. Utilizing Nested Normal Form to Design Redundancy Free JSON Schemas

    Directory of Open Access Journals (Sweden)

    Wai Yin Mok

    2016-12-01

    Full Text Available JSON (JavaScript Object Notation is a lightweight data-interchange format for the Internet. JSON is built on two structures: (1 a collection of name/value pairs and (2 an ordered list of values (http://www.json.org/. Because of this simple approach, JSON is easy to use and it has the potential to be the data interchange format of choice for the Internet. Similar to XML, JSON schemas allow nested structures to model hierarchical data. As data interchange over the Internet increases exponentially due to cloud computing or otherwise, redundancy free JSON data are an attractive form of communication because they improve the quality of data communication through eliminating update anomaly. Nested Normal Form, a normal form for hierarchical data, is a precise characterization of redundancy. A nested table, or a hierarchical schema, is in Nested Normal Form if and only if it is free of redundancy caused by multivalued and functional dependencies. Using Nested Normal Form as a guide, this paper introduces a JSON schema design methodology that begins with UML use case diagrams, communication diagrams and class diagrams that model a system under study. Based on the use cases’ execution frequencies and the data passed between involved parties in the communication diagrams, the proposed methodology selects classes from the class diagrams to be the roots of JSON scheme trees and repeatedly adds classes from the class diagram to the scheme trees as long as the schemas satisfy Nested Normal Form. This process continues until all of the classes in the class diagram have been added to some JSON scheme trees.

  5. Decomposition Criterion-based Redundancy Removal in Mechanical Structures

    Directory of Open Access Journals (Sweden)

    A. N. Bozhko

    2014-01-01

    Full Text Available The most important design solutions of production engineering for the assembly operation are an assembly sequence and assembly chart. Both are closely linked with each other and therefore are recorded in the single process flow sheet that is an assembly chart.Capability for successive order assembling and splitting into assembly units depends on a set of the product design properties from which the main ones are position mechanical connections used to locate details within a product. An adequate mathematical model of the mechanical connections of technical system is a hyper graph. It allows us to give the correct description of the location relation of variable-locality.The analysis of the array of drawings shows that many designs contain redundant mechanical connections. The inequality is a criterion of redundancy, where |X| is the number of tops of the hyper graph (details, and |R| is the number of hyper edges (full assembly bases. Excess of mutual coordination is a harmful phenomenon which at designing stage exhibits as unsolvable dimension chains, while at the assembly stage it shows as relocation. Redundant connections should be removed from a design at the earliest design-for-manufacturing stages. Removal of connections generates mechanical structures with different assembly properties. The work offers some important criteria of generation of irredundant mechanical structures. The paper considers in detail a maximum decomposition criterion, which allows us to receive structures with the greatest capability to split into assembly units. It shows that such structures exhibit high flexibility in assembling and are adaptable to various specifications and production processes.

  6. The restricted isometry property meets nonlinear approximation with redundant frames

    DEFF Research Database (Denmark)

    Gribonval, Rémi; Nielsen, Morten

    2013-01-01

    It is now well known that sparse or compressible vectors can be stably recovered from their low-dimensional projection, provided the projection matrix satisfies a Restricted Isometry Property (RIP). We establish new implications of the RIP with respect to nonlinear approximation in a Hilbert space...... with a redundant frame. The main ingredients of our approach are: a) Jackson and Bernstein inequalities, associated to the characterization of certain approximation spaces with interpolation spaces; b) a proof that for overcomplete frames which satisfy a Bernstein inequality, these interpolation spaces are nothing...

  7. Redundancy management of the Space Shuttle inertial measurement units

    Science.gov (United States)

    Thibodeau, J. R.; Bauer, S. R.

    1982-01-01

    A description is given of the inertial measurement unit (IMU) redundancy management (RM) techniques for automatic in-flight monitoring of inertial instrument performance by the Space Shuttles primary onboard guidance, navigation, and control computers. The techniques and rationale for detecting and identifying faulty instruments are discussed. Special attention is given to the design philosophy, thresholds, and error propagation characteristics of the IMU RM system. The derivation of thresholds is described from the viewpoint of reliability and the safety of the vehicle and crew.

  8. Energy distribution for Coefficients of Redundant Signal Representations of Music

    DEFF Research Database (Denmark)

    Endelt, Line Ørtoft; la Cour-Harbo, Anders

    2005-01-01

    In this paper we investigate how the energy is distributed in the coefficients vector of various redundant signal representations of music signals. The representations are found using Basis Pursuit, Matching Pursuit, Alternating Projections, Best Orthogonal Basis and Method of Frames, with five.......9 % of the energy in the coefficients, also the time consummation for finding the representations are considered. The distribution of energy in the coefficients of the representations found using Basis Pursuit, Matching Pursuit, Alternating Projections and Best Orthogonal Basis depends mainly on the signal...

  9. An inverse kinematic solution for kinematically redundant robot manipulators

    Science.gov (United States)

    Oh, S.-Y.; Bach, M.; Orin, D.

    The computation of the sequence of joint motion on the basis of the Cartesian motion of an interested member is addressed by an inverse kinematic analysis that is based on a Newton-Raphson numerical procedure. This procedure may be applied to the solution of the inverse kinematic problem for a manipulator of any mechanical configuration without having to derive a closed form solution beforehand. The technique is applicable to redundant manipulators, since additional constraints on other members, as well as on the end effector, may be imposed. The approach is presently applied to a seven-degree-of-freedom manipulator, and its obstacle-avoidance capability is demonstrated.

  10. The human brain maintains contradictory and redundant auditory sensory predictions.

    Directory of Open Access Journals (Sweden)

    Marika Pieszek

    Full Text Available Computational and experimental research has revealed that auditory sensory predictions are derived from regularities of the current environment by using internal generative models. However, so far, what has not been addressed is how the auditory system handles situations giving rise to redundant or even contradictory predictions derived from different sources of information. To this end, we measured error signals in the event-related brain potentials (ERPs in response to violations of auditory predictions. Sounds could be predicted on the basis of overall probability, i.e., one sound was presented frequently and another sound rarely. Furthermore, each sound was predicted by an informative visual cue. Participants' task was to use the cue and to discriminate the two sounds as fast as possible. Violations of the probability based prediction (i.e., a rare sound as well as violations of the visual-auditory prediction (i.e., an incongruent sound elicited error signals in the ERPs (Mismatch Negativity [MMN] and Incongruency Response [IR]. Particular error signals were observed even in case the overall probability and the visual symbol predicted different sounds. That is, the auditory system concurrently maintains and tests contradictory predictions. Moreover, if the same sound was predicted, we observed an additive error signal (scalp potential and primary current density equaling the sum of the specific error signals. Thus, the auditory system maintains and tolerates functionally independently represented redundant and contradictory predictions. We argue that the auditory system exploits all currently active regularities in order to optimally prepare for future events.

  11. The Evolution of Functionally Redundant Species; Evidence from Beetles

    Science.gov (United States)

    Scheffer, Marten; Vergnon, Remi; van Nes, Egbert H.; Cuppen, Jan G. M.; Peeters, Edwin T. H. M.; Leijs, Remko; Nilsson, Anders N.

    2015-01-01

    While species fulfill many different roles in ecosystems, it has been suggested that numerous species might actually share the same function in a near neutral way. So-far, however, it is unclear whether such functional redundancy really exists. We scrutinize this question using extensive data on the world’s 4168 species of diving beetles. We show that across the globe these animals have evolved towards a small number of regularly-spaced body sizes, and that locally co-existing species are either very similar in size or differ by at least 35%. Surprisingly, intermediate size differences (10–20%) are rare. As body-size strongly reflects functional aspects such as the food that these generalist predators can eat, these beetles thus form relatively distinct groups of functional look-a-likes. The striking global regularity of these patterns support the idea that a self-organizing process drives such species-rich groups to self-organize evolutionary into clusters where functional redundancy ensures resilience through an insurance effect. PMID:26447476

  12. Interactive streaming of stored multiview video using redundant frame structures.

    Science.gov (United States)

    Cheung, Gene; Ortega, Antonio; Cheung, Ngai-Man

    2011-03-01

    While much of multiview video coding focuses on the rate-distortion performance of compressing all frames of all views for storage or non-interactive video delivery over networks, we address the problem of designing a frame structure to enable interactive multiview streaming, where clients can interactively switch views during video playback. Thus, as a client is playing back successive frames (in time) for a given view, it can send a request to the server to switch to a different view while continuing uninterrupted temporal playback. Noting that standard tools for random access (i.e., I-frame insertion) can be bandwidth-inefficient for this application, we propose a redundant representation of I-, P-, and "merge" frames, where each original picture can be encoded into multiple versions, appropriately trading off expected transmission rate with storage, to facilitate view switching. We first present ad hoc frame structures with good performance when the view-switching probabilities are either very large or very small. We then present optimization algorithms that generate more general frame structures with better overall performance for the general case. We show in our experiments that we can generate redundant frame structures offering a range of tradeoff points between transmission and storage, e.g., outperforming simple I-frame insertion structures by up to 45% in terms of bandwidth efficiency at twice the storage cost.

  13. Inverse Kinematic Analysis of a Redundant Hybrid Climbing Robot

    Directory of Open Access Journals (Sweden)

    Adrian Peidro

    2015-11-01

    Full Text Available This paper presents the complete inverse kinematic analysis of a novel redundant truss-climbing robot with 10 degrees of freedom. The robot is bipedal and has a hybrid serial-parallel architecture, where each leg consists of two parallel mechanisms connected in series. By separating the equation for inverse kinematics into two parts - with each part associated with a different leg - an analytic solution to the inverse kinematics is derived. In the obtained solution, all the joint coordinates are calculated in terms of four or five decision variables (depending on the desired orientation whose values can be freely decided due to the redundancy of the robot. Next, the constrained inverse kinematic problem is also solved, which consists of finding the values of the decision variables that yield a desired position and orientation satisfying the joint limits. Taking the joint limits into consideration, it is shown that all the feasible solutions that yield a given desired position and orientation can be represented as 2D and 3D sets in the space of the decision variables. These sets provide a compact and complete solution to the inverse kinematics, with applications for motion planning.

  14. Computationally efficient measure of topological redundancy of biological and social networks

    Science.gov (United States)

    Albert, Réka; Dasgupta, Bhaskar; Hegde, Rashmi; Sivanathan, Gowri Sangeetha; Gitter, Anthony; Gürsoy, Gamze; Paul, Pradyut; Sontag, Eduardo

    2011-09-01

    It is well known that biological and social interaction networks have a varying degree of redundancy, though a consensus of the precise cause of this is so far lacking. In this paper, we introduce a topological redundancy measure for labeled directed networks that is formal, computationally efficient, and applicable to a variety of directed networks such as cellular signaling, and metabolic and social interaction networks. We demonstrate the computational efficiency of our measure by computing its value and statistical significance on a number of biological and social networks with up to several thousands of nodes and edges. Our results suggest a number of interesting observations: (1) Social networks are more redundant that their biological counterparts, (2) transcriptional networks are less redundant than signaling networks, (3) the topological redundancy of the C. elegans metabolic network is largely due to its inclusion of currency metabolites, and (4) the redundancy of signaling networks is highly (negatively) correlated with the monotonicity of their dynamics.

  15. Method and system for redundancy management of distributed and recoverable digital control system

    Science.gov (United States)

    Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

    2012-01-01

    A method and system for redundancy management is provided for a distributed and recoverable digital control system. The method uses unique redundancy management techniques to achieve recovery and restoration of redundant elements to full operation in an asynchronous environment. The system includes a first computing unit comprising a pair of redundant computational lanes for generating redundant control commands. One or more internal monitors detect data errors in the control commands, and provide a recovery trigger to the first computing unit. A second redundant computing unit provides the same features as the first computing unit. A first actuator control unit is configured to provide blending and monitoring of the control commands from the first and second computing units, and to provide a recovery trigger to each of the first and second computing units. A second actuator control unit provides the same features as the first actuator control unit.

  16. A succession of theories: purging redundancy from disturbance theory.

    Science.gov (United States)

    Pulsford, Stephanie A; Lindenmayer, David B; Driscoll, Don A

    2016-02-01

    The topics of succession and post-disturbance ecosystem recovery have a long and convoluted history. There is extensive redundancy within this body of theory, which has resulted in confusion, and the links among theories have not been adequately drawn. This review aims to distil the unique ideas from the array of theory related to ecosystem change in response to disturbance. This will help to reduce redundancy, and improve communication and understanding between researchers. We first outline the broad range of concepts that have developed over the past century to describe community change in response to disturbance. The body of work spans overlapping succession concepts presented by Clements in 1916, Egler in 1954, and Connell and Slatyer in 1977. Other theories describing community change include state and transition models, biological legacy theory, and the application of functional traits to predict responses to disturbance. Second, we identify areas of overlap of these theories, in addition to highlighting the conceptual and taxonomic limitations of each. In aligning each of these theories with one another, the limited scope and relative inflexibility of some theories becomes apparent, and redundancy becomes explicit. We identify a set of unique concepts to describe the range of mechanisms driving ecosystem responses to disturbance. We present a schematic model of our proposed synthesis which brings together the range of unique mechanisms that were identified in our review. The model describes five main mechanisms of transition away from a post-disturbance community: (i) pulse events with rapid state shifts; (ii) stochastic community drift; (iii) facilitation; (iv) competition; and (v) the influence of the initial composition of a post-disturbance community. In addition, stabilising processes such as biological legacies, inhibition or continuing disturbance may prevent a transition between community types. Integrating these six mechanisms with the functional

  17. Redundancy and joint limits of a seven degree of freedom upper limb exoskeleton.

    Science.gov (United States)

    Miller, Levi Makaio; Kim, Hyunchul; Rosen, Jacob

    2011-01-01

    The seven degree of freedom arm model is widely used in robotics, computer graphics, and much more. For wearable robotic systems, which are subject to joint limits, it is desirable to relate the joint limits to the redundantly of the system. A brief review of the arm model, redundant space and kinematics is presented. Following this review a closed form method is developed calculate the interval of the swivel angle (which characterizes the redundancy) that produces arm configurations that stay within joint limits.

  18. Cold-standby redundancy allocation problem with degrading components

    Science.gov (United States)

    Wang, Wei; Xiong, Junlin; Xie, Min

    2015-11-01

    Components in cold-standby state are usually assumed to be as good as new when they are activated. However, even in a standby environment, the components will suffer from performance degradation. This article presents a study of a redundancy allocation problem (RAP) for cold-standby systems with degrading components. The objective of the RAP is to determine an optimal design configuration of components to maximize system reliability subject to system resource constraints (e.g. cost, weight). As in most cases, it is not possible to obtain a closed-form expression for this problem, and hence, an approximated objective function is presented. A genetic algorithm with dual mutation is developed to solve such a constrained optimization problem. Finally, a numerical example is given to illustrate the proposed solution methodology.

  19. Testing and operating a multiprocessor chip with processor redundancy

    Science.gov (United States)

    Bellofatto, Ralph E; Douskey, Steven M; Haring, Rudolf A; McManus, Moyra K; Ohmacht, Martin; Schmunkamp, Dietmar; Sugavanam, Krishnan; Weatherford, Bryan J

    2014-10-21

    A system and method for improving the yield rate of a multiprocessor semiconductor chip that includes primary processor cores and one or more redundant processor cores. A first tester conducts a first test on one or more processor cores, and encodes results of the first test in an on-chip non-volatile memory. A second tester conducts a second test on the processor cores, and encodes results of the second test in an external non-volatile storage device. An override bit of a multiplexer is set if a processor core fails the second test. In response to the override bit, the multiplexer selects a physical-to-logical mapping of processor IDs according to one of: the encoded results in the memory device or the encoded results in the external storage device. On-chip logic configures the processor cores according to the selected physical-to-logical mapping.

  20. Dynamic active constraints for hyper-redundant flexible robots.

    Science.gov (United States)

    Kwok, Ka-Wai; Mylonas, George P; Sun, Loi Wah; Lerotic, Mirna; Clark, James; Athanasiou, Thanos; Darzi, Ara; Yang, Guang-Zhong

    2009-01-01

    In robot-assisted procedures, the surgeon's ability can be enhanced by navigation guidance through the use of virtual fixtures or active constraints. This paper presents a real-time modeling scheme for dynamic active constraints with fast and simple mesh adaptation under cardiac deformation and changes in anatomic structure. A smooth tubular pathway is constructed which provides assistance for a flexible hyper-redundant robot to circumnavigate the heart with the aim of undertaking bilateral pulmonary vein isolation as part of a modified maze procedure for the treatment of debilitating arrhythmia and atrial fibrillation. In contrast to existing approaches, the method incorporates detailed geometrical constraints with explicit manipulation margins of the forbidden region for an entire articulated surgical instrument, rather than just the end-effector itself. Detailed experimental validation is conducted to demonstrate the speed and accuracy of the instrument navigation with and without the use of the proposed dynamic constraints.

  1. A Unified Weighted Least Norm Method for Redundant Manipulator Control

    Directory of Open Access Journals (Sweden)

    Peng Chen

    2016-02-01

    Full Text Available A redundant manipulator usually has multiple kinematic solutions at the velocity level and can be used to optimize other criteria. Although the pseudo inverse of the Jacobian matrix generates a solution with the least 2 norm (LN, it does not consider other constraints imposed by the system or the environment. The general weighted least norm (GWLN method handles these general constraints via the concept of virtual joints, but this is not always feasible when the number of constraints exceeds the degrees of freedom. This paper proposes a unified weighted least norm method (UWLN to unify the LN and the GWLN methods. The UWLN method merges the constraint tasks into a quadratic criterion that poses no limitations on the number of constraint tasks. It also generates a least 2 norm solution when all constraints are deactivated, thereby unifying the LN and GWLN methods. A comparative simulation on a 7-DoF planar manipulator demonstrates the validity of the algorithm.

  2. Reliability Analysis and Calibration of Partial Safety Factors for Redundant Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    1998-01-01

    be included in the safety system and how partial safety factors can be calibrated. An example is presented illustrating how redundancy is taken into account in the safety system in e.g. the Danish codes. The example shows how partial safety factors can be calibrated to comply with the safety level......Redundancy is important to include in the design and analysis of structural systems. In most codes of practice redundancy is not directly taken into account. In the paper various definitions of a deterministic and reliability based redundancy measure are reviewed. It is described how reundancy can...

  3. Control algorithm implementation for a redundant degree of freedom manipulator

    Science.gov (United States)

    Cohan, Steve

    1991-01-01

    This project's purpose is to develop and implement control algorithms for a kinematically redundant robotic manipulator. The manipulator is being developed concurrently by Odetics Inc., under internal research and development funding. This SBIR contract supports algorithm conception, development, and simulation, as well as software implementation and integration with the manipulator hardware. The Odetics Dexterous Manipulator is a lightweight, high strength, modular manipulator being developed for space and commercial applications. It has seven fully active degrees of freedom, is electrically powered, and is fully operational in 1 G. The manipulator consists of five self-contained modules. These modules join via simple quick-disconnect couplings and self-mating connectors which allow rapid assembly/disassembly for reconfiguration, transport, or servicing. Each joint incorporates a unique drive train design which provides zero backlash operation, is insensitive to wear, and is single fault tolerant to motor or servo amplifier failure. The sensing system is also designed to be single fault tolerant. Although the initial prototype is not space qualified, the design is well-suited to meeting space qualification requirements. The control algorithm design approach is to develop a hierarchical system with well defined access and interfaces at each level. The high level endpoint/configuration control algorithm transforms manipulator endpoint position/orientation commands to joint angle commands, providing task space motion. At the same time, the kinematic redundancy is resolved by controlling the configuration (pose) of the manipulator, using several different optimizing criteria. The center level of the hierarchy servos the joints to their commanded trajectories using both linear feedback and model-based nonlinear control techniques. The lowest control level uses sensed joint torque to close torque servo loops, with the goal of improving the manipulator dynamic behavior

  4. Privacy Act

    Science.gov (United States)

    Learn about the Privacy Act of 1974, the Electronic Government Act of 2002, the Federal Information Security Management Act, and other information about the Environmental Protection Agency maintains its records.

  5. Redundancy in electronic health record corpora: analysis, impact on text mining performance and mitigation strategies

    Science.gov (United States)

    2013-01-01

    Background The increasing availability of Electronic Health Record (EHR) data and specifically free-text patient notes presents opportunities for phenotype extraction. Text-mining methods in particular can help disease modeling by mapping named-entities mentions to terminologies and clustering semantically related terms. EHR corpora, however, exhibit specific statistical and linguistic characteristics when compared with corpora in the biomedical literature domain. We focus on copy-and-paste redundancy: clinicians typically copy and paste information from previous notes when documenting a current patient encounter. Thus, within a longitudinal patient record, one expects to observe heavy redundancy. In this paper, we ask three research questions: (i) How can redundancy be quantified in large-scale text corpora? (ii) Conventional wisdom is that larger corpora yield better results in text mining. But how does the observed EHR redundancy affect text mining? Does such redundancy introduce a bias that distorts learned models? Or does the redundancy introduce benefits by highlighting stable and important subsets of the corpus? (iii) How can one mitigate the impact of redundancy on text mining? Results We analyze a large-scale EHR corpus and quantify redundancy both in terms of word and semantic concept repetition. We observe redundancy levels of about 30% and non-standard distribution of both words and concepts. We measure the impact of redundancy on two standard text-mining applications: collocation identification and topic modeling. We compare the results of these methods on synthetic data with controlled levels of redundancy and observe significant performance variation. Finally, we compare two mitigation strategies to avoid redundancy-induced bias: (i) a baseline strategy, keeping only the last note for each patient in the corpus; (ii) removing redundant notes with an efficient fingerprinting-based algorithm. aFor text mining, preprocessing the EHR corpus with

  6. Redundancy in electronic health record corpora: analysis, impact on text mining performance and mitigation strategies.

    Science.gov (United States)

    Cohen, Raphael; Elhadad, Michael; Elhadad, Noémie

    2013-01-16

    The increasing availability of Electronic Health Record (EHR) data and specifically free-text patient notes presents opportunities for phenotype extraction. Text-mining methods in particular can help disease modeling by mapping named-entities mentions to terminologies and clustering semantically related terms. EHR corpora, however, exhibit specific statistical and linguistic characteristics when compared with corpora in the biomedical literature domain. We focus on copy-and-paste redundancy: clinicians typically copy and paste information from previous notes when documenting a current patient encounter. Thus, within a longitudinal patient record, one expects to observe heavy redundancy. In this paper, we ask three research questions: (i) How can redundancy be quantified in large-scale text corpora? (ii) Conventional wisdom is that larger corpora yield better results in text mining. But how does the observed EHR redundancy affect text mining? Does such redundancy introduce a bias that distorts learned models? Or does the redundancy introduce benefits by highlighting stable and important subsets of the corpus? (iii) How can one mitigate the impact of redundancy on text mining? We analyze a large-scale EHR corpus and quantify redundancy both in terms of word and semantic concept repetition. We observe redundancy levels of about 30% and non-standard distribution of both words and concepts. We measure the impact of redundancy on two standard text-mining applications: collocation identification and topic modeling. We compare the results of these methods on synthetic data with controlled levels of redundancy and observe significant performance variation. Finally, we compare two mitigation strategies to avoid redundancy-induced bias: (i) a baseline strategy, keeping only the last note for each patient in the corpus; (ii) removing redundant notes with an efficient fingerprinting-based algorithm. (a)For text mining, preprocessing the EHR corpus with fingerprinting yields

  7. Redundancies in Data and their Effect on the Evaluation of Recommendation Systems

    DEFF Research Database (Denmark)

    Basaran, Daniel; Ntoutsi, Eirini; Zimek, Arthur

    2017-01-01

    A collection of datasets crawled from Amazon, “Amazon reviews”, is popular in the evaluation of recommendation systems. These datasets, however, contain redundancies (duplicated recommendations for variants of certain items). These redundancies went unnoticed in earlier use of these datasets...

  8. Three Design Principles of Language: The Search for Parsimony in Redundancy

    Science.gov (United States)

    Beekhuizen, Barend; Bod, Rens; Zuidema, Willem

    2013-01-01

    In this paper we present three design principles of language--experience, heterogeneity and redundancy--and present recent developments in a family of models incorporating them, namely Data-Oriented Parsing/Unsupervised Data-Oriented Parsing. Although the idea of some form of redundant storage has become part and parcel of parsing technologies and…

  9. The Problem of Empirical Redundancy of Constructs in Organizational Research: An Empirical Investigation

    Science.gov (United States)

    Le, Huy; Schmidt, Frank L.; Harter, James K.; Lauver, Kristy J.

    2010-01-01

    Construct empirical redundancy may be a major problem in organizational research today. In this paper, we explain and empirically illustrate a method for investigating this potential problem. We applied the method to examine the empirical redundancy of job satisfaction (JS) and organizational commitment (OC), two well-established organizational…

  10. Minister wants age balance to play greater role in redundancy selection

    NARCIS (Netherlands)

    Grünell, M.

    2004-01-01

    In May 2004, the Dutch Minister of Social Affairs proposed changes to the statutory rules on selection for redundancy, with less emphasis on the last in, first out seniority-based principle and a greater focus on distributing the redundancies between employees of different ages. The social partners

  11. Testing the race model inequality in redundant stimuli with variable onset asynchrony

    DEFF Research Database (Denmark)

    Gondan, Matthias

    2009-01-01

    In speeded response tasks with redundant signals, parallel processing of the signals is tested by the race model inequality. This inequality states that given a race of two signals, the cumulative distribution of response times for redundant stimuli never exceeds the sum of the cumulative distrib...

  12. 77 FR 28797 - Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection...

    Science.gov (United States)

    2012-05-16

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 12 and 90 Redundancy of Communications Systems: Backup Power Private Land Mobile...--REDUNDANCY OF COMMUNICATIONS SYSTEMS 0 1. The authority citation for part 12 continues to read as follows...

  13. Gemini planet imager observational calibrations X: non-redundant masking on GPI

    Science.gov (United States)

    Greenbaum, Alexandra Z.; Cheetham, Anthony; Sivaramakrishnan, Anand; Tuthill, Peter; Norris, Barnaby; Pueyo, Laurent; Sadakuni, Naru; Rantakyrö, Fredrik; Hibon, Pascale; Goodsell, Stephen; Hartung, Markus; Serio, Andrew; Cardwell, Andrew; Poyneer, Lisa; Macintosh, Bruce; Savransky, Dmitry; Perrin, Marshall D.; Wolff, Schuyler; Ingraham, Patrick; Thomas, Sandrine

    2014-08-01

    The Gemini Planet Imager (GPI) Extreme Adaptive Optics Coronograph contains an interferometric mode: a 10-hole non-redundant mask (NRM) in its pupil wheel. GPI operates at Y, J, H, and K bands, using an integral field unit spectrograph (IFS) to obtain spectral data at every image pixel. NRM on GPI is capable of imaging with a half resolution element inner working angle at moderate contrast, probing the region behind the coronagraphic spot. The fine features of the NRM PSF can provide a reliable check on the plate scale, while also acting as an attenuator for spectral standard calibrators that would otherwise saturate the full pupil. NRM commissioning data provides details about wavefront error in the optics as well as operations of adaptive optics control without pointing control from the calibration system. We compare lab and on-sky results to evaluate systematic instrument properties and examine the stability data in consecutive exposures. We discuss early on-sky performance, comparing images from integration and tests with the first on-sky images, and demonstrate resolving a known binary. We discuss the status of NRM and implications for future science with this mode.

  14. The Msi Family of RNA-Binding Proteins Function Redundantly as Intestinal Oncoproteins

    Directory of Open Access Journals (Sweden)

    Ning Li

    2015-12-01

    Full Text Available Members of the Msi family of RNA-binding proteins have recently emerged as potent oncoproteins in a range of malignancies. MSI2 is highly expressed in hematopoietic cancers, where it is required for disease maintenance. In contrast to the hematopoietic system, colorectal cancers can express both Msi family members, MSI1 and MSI2. Here, we demonstrate that, in the intestinal epithelium, Msi1 and Msi2 have analogous oncogenic effects. Further, comparison of Msi1/2-induced gene expression programs and transcriptome-wide analyses of Msi1/2-RNA-binding targets reveal significant functional overlap, including induction of the PDK-Akt-mTORC1 axis. Ultimately, we demonstrate that concomitant loss of function of both MSI family members is sufficient to abrogate the growth of human colorectal cancer cells, and Msi gene deletion inhibits tumorigenesis in several mouse models of intestinal cancer. Our findings demonstrate that MSI1 and MSI2 act as functionally redundant oncoproteins required for the ontogeny of intestinal cancers.

  15. On constrained reliability maximization using active redundancy in coherent systems with non-overlapping subsystems

    Directory of Open Access Journals (Sweden)

    Debasis Bhattacharya

    2015-01-01

    Full Text Available The paper investigates a problem of constrained reliability maximization by allocating redundancy and proposes how to solve it for a broad group of complex coherent systems. Redundancy is an effective engineering tool to enhance system reliability to make a system fail-safe. Since adding redundancy increases the cost and complexity of a system design, it should be used wisely. The work considers an exact solution to the problem under resource constraints and finds optimal redundancy numbers. The proposed method can accommodate any number of constraints. Numerical examples have been included. A sensitivity analysis has been carried out to show how sensitive the optimal allocation of redundant components and the gain in system reliability are to the budget allocation.

  16. Management of redundancy in flight control systems using optimal decision theory

    Science.gov (United States)

    1981-01-01

    The problem of using redundancy that exists between dissimilar systems in aircraft flight control is addressed. That is, using the redundancy that exists between a rate gyro and an accelerometer--devices that have dissimilar outputs which are related only through the dynamics of the aircraft motion. Management of this type of redundancy requires advanced logic so that the system can monitor failure status and can reconfigure itself in the event of one or more failures. An optimal decision theory was tutorially developed for the management of sensor redundancy and the theory is applied to two aircraft examples. The first example is the space shuttle and the second is a highly maneuvering high performance aircraft--the F8-C. The examples illustrate the redundancy management design process and the performance of the algorithms presented in failure detection and control law reconfiguration.

  17. Genome-wide CRISPR-Cas9 Screens Reveal Loss of Redundancy between PKMYT1 and WEE1 in Glioblastoma Stem-like Cells

    Directory of Open Access Journals (Sweden)

    Chad M. Toledo

    2015-12-01

    Full Text Available To identify therapeutic targets for glioblastoma (GBM, we performed genome-wide CRISPR-Cas9 knockout (KO screens in patient-derived GBM stem-like cells (GSCs and human neural stem/progenitors (NSCs, non-neoplastic stem cell controls, for genes required for their in vitro growth. Surprisingly, the vast majority GSC-lethal hits were found outside of molecular networks commonly altered in GBM and GSCs (e.g., oncogenic drivers. In vitro and in vivo validation of GSC-specific targets revealed several strong hits, including the wee1-like kinase, PKMYT1/Myt1. Mechanistic studies demonstrated that PKMYT1 acts redundantly with WEE1 to inhibit cyclin B-CDK1 activity via CDK1-Y15 phosphorylation and to promote timely completion of mitosis in NSCs. However, in GSCs, this redundancy is lost, most likely as a result of oncogenic signaling, causing GBM-specific lethality.

  18. Herpes simplex virus glycoproteins gB and gD function in a redundant fashion to promote secondary envelopment.

    Science.gov (United States)

    Johnson, David C; Wisner, Todd W; Wright, Catherine C

    2011-05-01

    Egress of herpes simplex virus (HSV) and other herpesviruses from cells involves extensive modification of cellular membranes and sequential envelopment and deenvelopment steps. HSV glycoproteins are important in these processes, and frequently two or more glycoproteins can largely suffice in any step. Capsids in the nucleus undergo primary envelopment at the inner nuclear membrane (INM), and then enveloped virus particles undergo deenvelopment by fusing with the outer nuclear membrane (ONM). Capsids delivered into the cytoplasm then undergo secondary envelopment, involving trans-Golgi network (TGN) membranes. The deenvelopment step involves HSV glycoproteins gB and gH/gL acting in a redundant fashion. This fusion has features common to the fusion that occurs between the virion envelope and cellular membranes when HSV enters cells, a process requiring gB, gD, and gH/gL. Whether HSV gD also participates (in a redundant fashion with gB or gH/gL) in deenvelopment has not been characterized. Secondary envelopment in the cytoplasm is known to involve HSV gD and gE/gI, also acting in a redundant fashion. Whether gB might also contribute to secondary envelopment, collaborating with gD and gE/gI, is also not clear. To address these questions, we constructed an HSV double mutant lacking gB and gD. The HSV gB(-)/gD(-) mutant exhibited no substantial defects in nuclear egress. In contrast, secondary envelopment was markedly reduced, and there were numerous unenveloped capsids that accumulated in the cytoplasm, as well as increased numbers of partially enveloped capsids and morphologically aberrant enveloped particles with thicker, oblong tegument layers. These defects were different from those observed with HSV gD(-)/gE(-)/gI(-) mutants, which accumulated capsids in large, aggregated masses in the cytoplasm. Our results suggest that HSV gB functions in secondary envelopment, apparently acting downstream of gE/gI.

  19. Past and Present Biophysical Redundancy of Countries as a Buffer to Changes in Food Supply

    Science.gov (United States)

    Fader, Marianela; Rulli, Maria Cristina; Carr, Joel; Dell' Angelo, Jampel; D' Odorico, Paolo; Gephart, Jessica A.; Kummu, Matti; Magliocca, Nicholas; Porkka, Miina; Prell, Christina; hide

    2016-01-01

    Spatially diverse trends in population growth, climate change, industrialization, urbanization and economic development are expected to change future food supply and demand. These changes may affect the suitability of land for food production, implying elevated risks especially for resource constrained, food-importing countries. We present the evolution of biophysical redundancy for agricultural production at country level, from 1992 to 2012. Biophysical redundancy, defined as unused biotic and abiotic environmental resources, is represented by the potential food production of 'spare land', available water resources (i.e., not already used for human activities), as well as production increases through yield gap closure on cultivated areas and potential agricultural areas. In 2012, the biophysical redundancy of 75 (48) countries, mainly in North Africa, Western Europe, the Middle East and Asia, was insufficient to produce the caloric nutritional needs for at least 50% (25%) of their population during a year. Biophysical redundancy has decreased in the last two decades in 102 out of 155 countries, 11 of these went from high to limited redundancy, and nine of these from limited to very low redundancy. Although the variability of the drivers of change across different countries is high, improvements in yield and population growth have a clear impact on the decreases of redundancy towards the very low redundancy category. We took a more detailed look at countries classified as 'Low Income Economies (LIEs)' since they are particularly vulnerable to domestic or external food supply changes, due to their limited capacity to offset for food supply decreases with higher purchasing power on the international market. Currently, nine LIEs have limited or very low biophysical redundancy. Many of these showed a decrease in redundancy over the last two decades, which is not always linked with improvements in per capita food availability.

  20. Does plant species richness guarantee the resilience of local medical systems? A perspective from utilitarian redundancy.

    Directory of Open Access Journals (Sweden)

    Flávia Rosa Santoro

    Full Text Available Resilience is related to the ability of a system to adjust to disturbances. The Utilitarian Redundancy Model has emerged as a tool for investigating the resilience of local medical systems. The model determines the use of species richness for the same therapeutic function as a facilitator of the maintenance of these systems. However, predictions generated from this model have not yet been tested, and a lack of variables exists for deeper analyses of resilience. This study aims to address gaps in the Utilitarian Redundancy Model and to investigate the resilience of two medical systems in the Brazilian semi-arid zone. As a local illness is not always perceived in the same way that biomedicine recognizes, the term "therapeutic targets" is used for perceived illnesses. Semi-structured interviews with local experts were conducted using the free-listing technique to collect data on known medicinal plants, usage preferences, use of redundant species, characteristics of therapeutic targets, and the perceived severity for each target. Additionally, participatory workshops were conducted to determine the frequency of targets. The medical systems showed high species richness but low levels of species redundancy. However, if redundancy was present, it was the primary factor responsible for the maintenance of system functions. Species richness was positively associated with therapeutic target frequencies and negatively related to target severity. Moreover, information about redundant species seems to be largely idiosyncratic; this finding raises questions about the importance of redundancy for resilience. We stress the Utilitarian Redundancy Model as an interesting tool to be used in studies of resilience, but we emphasize that it must consider the distribution of redundancy in terms of the treatment of important illnesses and the sharing of information. This study has identified aspects of the higher and lower vulnerabilities of medical systems, adding

  1. Diversification of Processors Based on Redundancy in Instruction Set

    Science.gov (United States)

    Ichikawa, Shuichi; Sawada, Takashi; Hata, Hisashi

    By diversifying processor architecture, computer software is expected to be more resistant to plagiarism, analysis, and attacks. This study presents a new method to diversify instruction set architecture (ISA) by utilizing the redundancy in the instruction set. Our method is particularly suited for embedded systems implemented with FPGA technology, and realizes a genuine instruction set randomization, which has not been provided by the preceding studies. The evaluation results on four typical ISAs indicate that our scheme can provide a far larger degree of freedom than the preceding studies. Diversified processors based on MIPS architecture were actually implemented and evaluated with Xilinx Spartan-3 FPGA. The increase of logic scale was modest: 5.1% in Specialized design and 3.6% in RAM-mapped design. The performance overhead was also modest: 3.4% in Specialized design and 11.6% in RAM-mapped design. From these results, our scheme is regarded as a practical and promising way to secure FPGA-based embedded systems.

  2. Triple Modular Redundancy verification via heuristic netlist analysis

    Directory of Open Access Journals (Sweden)

    Giovanni Beltrame

    2015-08-01

    Full Text Available Triple Modular Redundancy (TMR is a common technique to protect memory elements for digital processing systems subject to radiation effects (such as in space, high-altitude, or near nuclear sources. This paper presents an approach to verify the correct implementation of TMR for the memory elements of a given netlist (i.e., a digital circuit specification using heuristic analysis. The purpose is detecting any issues that might incur during the use of automatic tools for TMR insertion, optimization, place and route, etc. Our analysis does not require a testbench and can perform full, exhaustive coverage within less than an hour even for large designs. This is achieved by applying a divide et impera approach, splitting the circuit into smaller submodules without loss of generality, instead of applying formal verification to the whole netlist at once. The methodology has been applied to a production netlist of the LEON2-FT processor that had reported errors during radiation testing, successfully showing a number of unprotected memory elements, namely 351 flip-flops.

  3. Redundancy Optimization for Error Recovery in Digital Microfluidic Biochips

    DEFF Research Database (Denmark)

    Alistar, Mirela; Pop, Paul; Madsen, Jan

    2015-01-01

    Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate all the necessary functions for biochemical analysis. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow, but as discrete droplets. Research......Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate all the necessary functions for biochemical analysis. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow, but as discrete droplets...... of a bioassay, operations could experience transient errors (e.g., erroneous droplet volumes), thus impacting negatively the correctness of the application. Researchers have proposed fault-tolerance approaches, which apply predetermined recovery actions at the moment when errors are detected. In this paper, we...... for fault-tolerance. Error recovery is performed such that the number of transient errors tolerated is maximized and the timing constraints of the biochemical application are satisfied. The proposed redundancy optimization approach has been evaluated using several benchmarks....

  4. Redundant unbalance compensation of an active magnetic bearing system

    Science.gov (United States)

    Hutterer, Markus; Kalteis, Gerald; Schrödl, Manfred

    2017-09-01

    To achieve a good running behavior of a magnetic levitated rotor, a well-developed position controller and different compensation methods are required. Two very important structures in this context are the reduction of the gyroscopic effect and the unbalance vibration. Both structures have in common that they need the angular velocity information for calculation. For industrial applications this information is normally provided by an angle sensor which is fixed on the rotor. The angle information is also necessary for the field oriented control of the electrical drive. The main drawback of external position sensors are the case of a breakdown or an error of the motor controller. Therefore, the magnetic bearing can get unstable, because no angular velocity information is provided. To overcome this problem the presented paper describes the development of a selfsensing unbalance rejection in combination with a selfsensing speed control of the motor controller. Selfsensing means in this context that no angle sensor is required for the unbalance or torque control. With such structures two redundant speed and angle information sources are available and can be used for the magnetic bearing and the motor controller without the usage of an angle sensor.

  5. Magnetic resonanse imaging findings of redundant nerve roots syndrome

    Directory of Open Access Journals (Sweden)

    Nihat Taşdemir

    2012-06-01

    Full Text Available Objectives: The purpose of our study was to determinethe findings of redundant nerve roots syndrome (RNRSin lumbar stenosis by magnetic resonance (MR imaging.Materials and methods: A total of 8906 lumber MR imagingwere evaluated, retrospectively. RNRS were definedas a tortuosity of elongated nerve roots in the subarachnoidspace accompanied by spinal stenosis whichdetermined by images of MR. A total of 8 patients weredefined as RNRS.Results: Six of RNRS patients are female. The averageage of the 8 patients who were defined as RNRS byMRI was 70.0±15.0 (range, 39-87 years. The anteriorposteriorand transverse diameter of the spinal canal wasmeasured. The mean of the anterior-posterior diameter(mm and transverse diameter (mm of the spinal canalwere 11.50±2.0 mm (range; 8.0-14.0 mm 8.4 mm and8.37±0.51 mm (range; 8.0-9.0 mm, respectively.Conclusion: In patients with spinal stenosis and RNRSshould also be considered.

  6. Accurate and diverse recommendations via eliminating redundant correlations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Tao; Su Riqi; Liu Runran; Jiang Luoluo; Wang Binghong [Department of Modern Physics and Nonlinear Science Center, University of Science and Technology of China, Hefei Anhui 230026 (China); Zhang Yicheng [Department of Physics, University of Fribourg, Chemin du Musee 3, CH-1700 Fribourg (Switzerland)], E-mail: bhwang@ustc.edu.cn

    2009-12-15

    In this paper, based on a weighted projection of a bipartite user-object network, we introduce a personalized recommendation algorithm, called network-based inference (NBI), which has higher accuracy than the classical algorithm, namely collaborative filtering. In NBI, the correlation resulting from a specific attribute may be repeatedly counted in the cumulative recommendations from different objects. By considering the higher order correlations, we design an improved algorithm that can, to some extent, eliminate the redundant correlations. We test our algorithm on two benchmark data sets, MovieLens and Netflix. Compared with NBI, the algorithmic accuracy, measured by the ranking score, can be further improved by 23 per cent for MovieLens and 22 per cent for Netflix. The present algorithm can even outperform the Latent Dirichlet Allocation algorithm, which requires much longer computational time. Furthermore, most previous studies considered the algorithmic accuracy only; in this paper, we argue that the diversity and popularity, as two significant criteria of algorithmic performance, should also be taken into account. With more or less the same accuracy, an algorithm giving higher diversity and lower popularity is more favorable. Numerical results show that the present algorithm can outperform the standard one simultaneously in all five adopted metrics: lower ranking score and higher precision for accuracy, larger Hamming distance and lower intra-similarity for diversity, as well as smaller average degree for popularity.

  7. Accurate and diverse recommendations via eliminating redundant correlations

    Science.gov (United States)

    Zhou, Tao; Su, Ri-Qi; Liu, Run-Ran; Jiang, Luo-Luo; Wang, Bing-Hong; Zhang, Yi-Cheng

    2009-12-01

    In this paper, based on a weighted projection of a bipartite user-object network, we introduce a personalized recommendation algorithm, called network-based inference (NBI), which has higher accuracy than the classical algorithm, namely collaborative filtering. In NBI, the correlation resulting from a specific attribute may be repeatedly counted in the cumulative recommendations from different objects. By considering the higher order correlations, we design an improved algorithm that can, to some extent, eliminate the redundant correlations. We test our algorithm on two benchmark data sets, MovieLens and Netflix. Compared with NBI, the algorithmic accuracy, measured by the ranking score, can be further improved by 23 per cent for MovieLens and 22 per cent for Netflix. The present algorithm can even outperform the Latent Dirichlet Allocation algorithm, which requires much longer computational time. Furthermore, most previous studies considered the algorithmic accuracy only; in this paper, we argue that the diversity and popularity, as two significant criteria of algorithmic performance, should also be taken into account. With more or less the same accuracy, an algorithm giving higher diversity and lower popularity is more favorable. Numerical results show that the present algorithm can outperform the standard one simultaneously in all five adopted metrics: lower ranking score and higher precision for accuracy, larger Hamming distance and lower intra-similarity for diversity, as well as smaller average degree for popularity.

  8. State Estimation for Robots with Complementary Redundant Sensors

    Directory of Open Access Journals (Sweden)

    Daniele Carnevale

    2015-10-01

    Full Text Available In this paper, robots equipped with two complementary typologies of redundant sensors are considered: one typology provides sharp measures of some geometrical entity related to the robot pose (e.g., distance or angle but is not univocally associated with this quantity; the other typology is univocal but is characterized by a low level of precision. A technique is proposed to properly combine these two kinds of measurement both in a stochastic and in a deterministic context. This framework may occur in robotics, for example, when the distance from a known landmark is detected by two different sensors, one based on the signal strength or time of flight of the signal, while the other one measures the phase-shift of the signal, which has a sharp but periodical dependence on the robot-landmark distance. In the stochastic case, an effective solution is a two-stage extended Kalman filter (EKF which exploits the precise periodic signal only when the estimate of the robot position is sufficiently precise. In the deterministic setting, an approach based on a switching hybrid observer is proposed, and results are analyzed via simulation examples.

  9. Pathway and enzyme redundancy in putrescine catabolism in Escherichia coli.

    Science.gov (United States)

    Schneider, Barbara L; Reitzer, Larry

    2012-08-01

    Putrescine as the sole carbon source requires a novel catabolic pathway with glutamylated intermediates. Nitrogen limitation does not induce genes of this glutamylated putrescine (GP) pathway but instead induces genes for a putrescine catabolic pathway that starts with a transaminase-dependent deamination. We determined pathway utilization with putrescine as the sole nitrogen source by examining mutants with defects in both pathways. Blocks in both the GP and transaminase pathways were required to prevent growth with putrescine as the sole nitrogen source. Genetic and biochemical analyses showed redundant enzymes for γ-aminobutyraldehyde dehydrogenase (PatD/YdcW and PuuC), γ-aminobutyrate transaminase (GabT and PuuE), and succinic semialdehyde dehydrogenase (GabD and PuuC). PuuC is a nonspecific aldehyde dehydrogenase that oxidizes all the aldehydes in putrescine catabolism. A puuP mutant failed to use putrescine as the nitrogen source, which implies one major transporter for putrescine as the sole nitrogen source. Analysis of regulation of the GP pathway shows induction by putrescine and not by a product of putrescine catabolism and shows that putrescine accumulates in puuA, puuB, and puuC mutants but not in any other mutant. We conclude that two independent sets of enzymes can completely degrade putrescine to succinate and that their relative importance depends on the environment.

  10. Caenorhabditis elegans glutamylating enzymes function redundantly in male mating

    Directory of Open Access Journals (Sweden)

    Daniel G. Chawla

    2016-09-01

    Full Text Available Microtubule glutamylation is an important modulator of microtubule function and has been implicated in the regulation of centriole stability, neuronal outgrowth and cilia motility. Glutamylation of the microtubules is catalyzed by a family of tubulin tyrosine ligase-like (TTLL enzymes. Analysis of individual TTLL enzymes has led to an understanding of their specific functions, but how activities of the TTLL enzymes are coordinated to spatially and temporally regulate glutamylation remains relatively unexplored. We have undertaken an analysis of the glutamylating TTLL enzymes in C. elegans. We find that although all five TTLL enzymes are expressed in the embryo and adult worm, loss of individual enzymes does not perturb microtubule function in embryonic cell divisions. Moreover, normal dye-filling, osmotic avoidance and male mating behavior indicate the presence of functional amphid cilia and male-specific neurons. A ttll-4(tm3310; ttll-11(tm4059; ttll-5(tm3360 triple mutant, however, shows reduced male mating efficiency due to a defect in the response step, suggesting that these three enzymes function redundantly, and that glutamylation is required for proper function of the male-specific neurons.

  11. Non-Redundant Masking Science on the Gemini Planet Imager

    Science.gov (United States)

    Greenbaum, Alexandra; Cheetham, Anthony; Sivaramakrishnan, A.; Pueyo, L.; Wolff, S.; Perrin, M. D.; Ingraham, P.; Thomas, S.; Norris, B.; Tuthill, P.

    2014-01-01

    Non-Redundant Mask Interferometry (NRM) transforms a fully transmissive pupil into an interferometer by masking all but a set of holes that form unique baselines. The interferometric resolution and dynamic range makes the technique suitable for probing potential planet forming regions. So called "transition disks" may or may not have perturbing bodies in the process of changing the disk morphology (cleared gaps, etc.) and require close-in imaging to peer inside disk clearings and spot companions that are several orders of magnitude fainter than the host star. Improvements in contrast for NRM rely on both the wavefront quality as well as the data reduction methods. Image plane modeling of the NRM point-spread function avoids ringing and windowing effects that result in Fourier domain analysis of bad pixel and restricted field of view data. The Gemini Planet Imager (GPI), an extreme adaptive optics system and integral field spectrograph, is equipped with a 10-hole NRM. We present recent results from GPI NRM I&T data using the image plane approach to measure visibilities as an early prediction of performance. We additionally discuss the feasibility of measuring visibility amplitudes from ground-based studies and their implications for NRM science with GPI.

  12. Redundant Interdependencies Boost the Robustness of Multiplex Networks

    Directory of Open Access Journals (Sweden)

    Filippo Radicchi

    2017-01-01

    Full Text Available In the analysis of the robustness of multiplex networks, it is commonly assumed that a node is functioning only if its interdependent nodes are simultaneously functioning. According to this model, a multiplex network becomes more and more fragile as the number of layers increases. In this respect, the addition of a new layer of interdependent nodes to a preexisting multiplex network will never improve its robustness. Whereas such a model seems appropriate to understand the effect of interdependencies in the simplest scenario of a network composed of only two layers, it may seem unsuitable to characterize the robustness of real systems formed by multiple network layers. In fact, it seems unrealistic that a real system evolved, through the development of multiple layers of interactions, towards a fragile structure. In this paper, we introduce a model of percolation where the condition that makes a node functional is that the node is functioning in at least two of the layers of the network. The model reduces to the commonly adopted percolation model for multiplex networks when the number of layers equals two. For larger numbers of layers, however, the model describes a scenario where the addition of new layers boosts the robustness of the system by creating redundant interdependencies among layers. We prove this fact thanks to the development of a message-passing theory that is able to characterize the model in both synthetic and real-world multiplex graphs.

  13. Redundancy in Kiss1 Expression Safeguards Reproduction in the Mouse

    Science.gov (United States)

    Popa, Simina M.; Moriyama, Ryutaro M.; Caligioni, Claudia S.; Yang, Jasmine J.; Cho, Caroline M.; Concepcion, Tessa L.; Oakley, Amy E.; Lee, In Hae; Sanz, Elisenda; Amieux, Paul S.; Caraty, Alain; Palmiter, Richard D.; Navarro, Victor M.; Chan, Yee-Ming; Seminara, Stephanie B.; Clifton, Donald K.

    2013-01-01

    Kisspeptin (Kiss1) signaling to GnRH neurons is widely acknowledged to be a prerequisite for puberty and reproduction. Animals lacking functional genes for either kisspeptin or its receptor exhibit low gonadotropin secretion and infertility. Paradoxically, a recent study reported that genetic ablation of nearly all Kiss1-expressing neurons (Kiss1 neurons) does not impair reproduction, arguing that neither Kiss1 neurons nor their products are essential for sexual maturation. We posited that only minute quantities of kisspeptin are sufficient to support reproduction. If this were the case, animals having dramatically reduced Kiss1 expression might retain fertility, testifying to the redundancy of Kiss1 neurons and their products. To test this hypothesis and to determine whether males and females differ in the required amount of kisspeptin needed for reproduction, we used a mouse (Kiss1-CreGFP) that has a severe reduction in Kiss1 expression. Mice that are heterozygous and homozygous for this allele (Kiss1Cre/+ and Kiss1Cre/Cre) have ∼50% and 95% reductions in Kiss1 transcript, respectively. We found that although male Kiss1Cre/Cre mice sire normal-sized litters, female Kiss1Cre/Cre mice exhibit significantly impaired fertility and ovulation. These observations suggest that males require only 5% of normal Kiss1 expression to be reproductively competent, whereas females require higher levels for reproductive success. PMID:23736293

  14. The error performance analysis over cyclic redundancy check codes

    Science.gov (United States)

    Yoon, Hee B.

    1991-06-01

    The burst error is generated in digital communication networks by various unpredictable conditions, which occur at high error rates, for short durations, and can impact services. To completely describe a burst error one has to know the bit pattern. This is impossible in practice on working systems. Therefore, under the memoryless binary symmetric channel (MBSC) assumptions, the performance evaluation or estimation schemes for digital signal 1 (DS1) transmission systems carrying live traffic is an interesting and important problem. This study will present some analytical methods, leading to efficient detecting algorithms of burst error using cyclic redundancy check (CRC) code. The definition of burst error is introduced using three different models. Among the three burst error models, the mathematical model is used in this study. The probability density function, function(b) of burst error of length b is proposed. The performance of CRC-n codes is evaluated and analyzed using function(b) through the use of a computer simulation model within CRC block burst error. The simulation result shows that the mean block burst error tends to approach the pattern of the burst error which random bit errors generate.

  15. Analysis of functional redundancies within the Arabidopsis TCP transcription factor family.

    Science.gov (United States)

    Danisman, Selahattin; van Dijk, Aalt D J; Bimbo, Andrea; van der Wal, Froukje; Hennig, Lars; de Folter, Stefan; Angenent, Gerco C; Immink, Richard G H

    2013-12-01

    Analyses of the functions of TEOSINTE-LIKE1, CYCLOIDEA, and PROLIFERATING CELL FACTOR1 (TCP) transcription factors have been hampered by functional redundancy between its individual members. In general, putative functionally redundant genes are predicted based on sequence similarity and confirmed by genetic analysis. In the TCP family, however, identification is impeded by relatively low overall sequence similarity. In a search for functionally redundant TCP pairs that control Arabidopsis leaf development, this work performed an integrative bioinformatics analysis, combining protein sequence similarities, gene expression data, and results of pair-wise protein-protein interaction studies for the 24 members of the Arabidopsis TCP transcription factor family. For this, the work completed any lacking gene expression and protein-protein interaction data experimentally and then performed a comprehensive prediction of potential functional redundant TCP pairs. Subsequently, redundant functions could be confirmed for selected predicted TCP pairs by genetic and molecular analyses. It is demonstrated that the previously uncharacterized class I TCP19 gene plays a role in the control of leaf senescence in a redundant fashion with TCP20. Altogether, this work shows the power of combining classical genetic and molecular approaches with bioinformatics predictions to unravel functional redundancies in the TCP transcription factor family.

  16. Manipulation planning for redundant robots: A practical approach

    Energy Technology Data Exchange (ETDEWEB)

    Ahuactzin, J.M. [Univ. de las Americas, Puebla (Mexico); Gupta, K. [Simon Fraser Univ., Burnaby, British Columbia (Canada). School of Engineering Science; Mazer, E. [INRIA Rhone Alpes, Montbonnot (France)

    1998-07-01

    An emerging paradigm in solving the classical motion-planning problem (among static obstacles) is to capture the connectivity of the configuration space using a finite (but possibly large) set of landmarks (or nodes) in it. In this paper, the authors extend this paradigm to manipulation-planning problem, where the goal is to plan the motion of a robot so that it can move a given object from an initial configuration to a final configuration while avoiding collisions with the static obstacles and other movable objects in the environment. The specific approach adapts Adriadne`s clew algorithm, which has been shown effective for classical motion-planning problems (Mazer et al. 1994; Ahuactzin 1994). In the approach, landmarks are placed in lower dimensional submanifolds of the composite configuration space. These landmarks represent stable grasps that are reachable from the initial configuration. From each new landmark, the planner attempts to reach the goal configuration by executing a local planner, again in a lower (but different) dimensional submanifold of the composite configuration space. The approach is probabilistically resolution complete, does not assume that a closed-form inverse-kinematics solution for the manipulator is available, and is particularly suitable for redundant manipulators. The authors also demonstrate that the approach is practical for realistic problems in three-dimensional environments with manipulator arms having fairly large numbers of degrees of freedom. They have experimented with this approach for a 7-DOF manipulator in 3-D environments with one movable object, and computation times range between a few minutes and a few tens of minutes--in the experiments, between 3 min to 15 min, depending on the task difficulty.

  17. ACT Test

    Science.gov (United States)

    ... Content View Sources Ask Us Also Known As ACT Activated Coagulation Time Formal Name Activated Clotting Time ... What is being tested? The activated clotting time (ACT) is a test that is used primarily to ...

  18. Quantum Darwinism Requires an Extra-Theoretical Assumption of Encoding Redundancy

    Science.gov (United States)

    Fields, Chris

    2010-10-01

    Observers restricted to the observation of pointer states of apparatus cannot conclusively demonstrate that the pointer of an apparatus mathcal{A} registers the state of a system of interest S without perturbing S. Observers cannot, therefore, conclusively demonstrate that the states of a system S are redundantly encoded by pointer states of multiple independent apparatus without destroying the redundancy of encoding. The redundancy of encoding required by quantum Darwinism must, therefore, be assumed from outside the quantum-mechanical formalism and without the possibility of experimental demonstration.

  19. Design and test experience with a triply redundant digital fly-by-wire control system

    Science.gov (United States)

    Szalai, K. J.; Felleman, P. G.; Gera, J.; Glover, R. D.

    1976-01-01

    A triplex digital fly-by-wire flight control system was developed and then installed in a NASA F-8C aircraft to provide fail-operative, full authority control. Hardware and software redundancy management techniques were designed to detect and identify failures in the system. Control functions typical of those projected for future actively controlled vehicles were implemented. This paper describes the principal design features of the system, the implementation of computer, sensor, and actuator redundancy management, and the ground test results. An automated test program to verify sensor redundancy management software is also described.

  20. Kinematics analysis of a novel planar parallel manipulator with kinematic redundancy

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Haibo; Guo, Sheng [Beijing Jiaotong University, Beijing (China)

    2017-04-15

    In this paper, a novel planar parallel manipulator with kinematic redundancy is proposed. First, the Degrees of freedom (DOF) of the whole parallel manipulator and the Relative DOF (RDOF) between the moving platform and fixed base are studied. The results indicate that the proposed mechanism is kinematically redundant. Then, the kinematics, Jacobian matrices and workspace of this proposed parallel manipulator with kinematic redundancy are analyzed. Finally, the statics simulation of the proposed parallel manipulator is performed. The obtained stress and displacement distribution can be used to determine the easily destroyed place in the mechanism configurations.

  1. ACTS 2014

    DEFF Research Database (Denmark)

    . For the 2014 festival, the museum has entered into a collaboration with the Department for Performance Design at Roskilde University – with continued focus on sound and performance art, and social art in public spaces. With ACTS, art moves out of its usual exhibition space and instead utilizes the city, its...... various possibilities and public spaces as a stage. ACTS takes place in and around the museum and diverse locations in Roskilde city. ACTS is partly curated by the museum staff and partly by guest curators. ACTS 2014 is supported by Nordea-fonden and is a part of the project The Museum goes downtown.......Co-curator of ACTS 2014 together with Rasmus Holmboe, Judith Schwarzbart and Sanne Kofoed. ACTS is the Museum of Contemporary Art’s international bi-annual festival. ACTS was established in 2011 and, while the primary focus is on sound and performance art, it also looks toward socially oriented art...

  2. Geometric technique for the kinematic modeling of a 5 DOF redundant manipulator

    CSIR Research Space (South Africa)

    Makondo, N

    2012-11-01

    Full Text Available This paper describes a geometrical method for solving the inverse kinematic (IK) problem of a 5 Degrees of Freedom (DOF) redundant manipulator. A geometric inverse kinematics solution is desirable as it provides complete and simple solutions...

  3. Functional redundancy patterns reveal non-random assembly rules in a species-rich marine assemblage.

    Directory of Open Access Journals (Sweden)

    Nicolas Guillemot

    Full Text Available The relationship between species and the functional diversity of assemblages is fundamental in ecology because it contains key information on functional redundancy, and functionally redundant ecosystems are thought to be more resilient, resistant and stable. However, this relationship is poorly understood and undocumented for species-rich coastal marine ecosystems. Here, we used underwater visual censuses to examine the patterns of functional redundancy for one of the most diverse vertebrate assemblages, the coral reef fishes of New Caledonia, South Pacific. First, we found that the relationship between functional and species diversity displayed a non-asymptotic power-shaped curve, implying that rare functions and species mainly occur in highly diverse assemblages. Second, we showed that the distribution of species amongst possible functions was significantly different from a random distribution up to a threshold of ∼90 species/transect. Redundancy patterns for each function further revealed that some functions displayed fast rates of increase in redundancy at low species diversity, whereas others were only becoming redundant past a certain threshold. This suggested non-random assembly rules and the existence of some primordial functions that would need to be fulfilled in priority so that coral reef fish assemblages can gain a basic ecological structure. Last, we found little effect of habitat on the shape of the functional-species diversity relationship and on the redundancy of functions, although habitat is known to largely determine assemblage characteristics such as species composition, biomass, and abundance. Our study shows that low functional redundancy is characteristic of this highly diverse fish assemblage, and, therefore, that even species-rich ecosystems such as coral reefs may be vulnerable to the removal of a few keystone species.

  4. Redundancy resolution of a human arm for controlling a seven DOF wearable robotic system.

    Science.gov (United States)

    Kim, Hyunchul; Miller, Levi Makaio; Al-Refai, Aimen; Brand, Moshe; Rosen, Jacob

    2011-01-01

    The human arm including the shoulder, elbow, wrist joints and exclusion scapular motion has 7 Degrees of Freedom (DOF) while positioning of the wrist in space and orientating the palm is a task that requires 6 DOF. As such it includes one more DOF than is needed to complete the task. Given the redundant nature of the arm, multiple arm configurations can be used to complete a task, which is expressed mathematically by none unique solution for the inverse kinematics. Despite this mathematical difficulty, the motor control provides a unique solution for the arm redundancy as the arm is moved in space. Resolving this redundancy is becoming critical as the human interacts with a wearable robotic system(exoskeleton) which includes the same redundancy as the human arm. Therefore, the inverse kinematics solution resolving the redundancy of these two coupled systems must be identical in order to guarantee a seamless integration. The redundancy of the arm can be formulated kinematically by defining the swivel angle - the rotation angle of the plane including the upper and lower arm around a virtual axis connecting the shoulder and wrist joints which are fixed in space. Analyzing reaching tasks recorded with a motion capture lab indicates that the swivel angle is selected such that when the elbow joint is flexed, the palm points the head. Based on these experimental results, selecting the point around the center of the head as a stationary target allows to calculate the swivel angle and in that way to resolve the human arm redundancy. Experimental results indicated that by using the proposed redundancy resolution criteria the error between the predicted swivel angle and the actual swivel angle adopted by the motor control system is less then 5 Deg. This criterion or a synthesis of several additional criteria may improve the synergistic relationships between an operator and a wearable robotic system.

  5. The reliability analysis of a separated, dual fail operational redundant strapdown IMU. [inertial measurement unit

    Science.gov (United States)

    Motyka, P.

    1983-01-01

    A methodology for quantitatively analyzing the reliability of redundant avionics systems, in general, and the dual, separated Redundant Strapdown Inertial Measurement Unit (RSDIMU), in particular, is presented. The RSDIMU is described and a candidate failure detection and isolation system presented. A Markov reliability model is employed. The operational states of the system are defined and the single-step state transition diagrams discussed. Graphical results, showing the impact of major system parameters on the reliability of the RSDIMU system, are presented and discussed.

  6. New Inverse Kinematics Algorithms Combining Closed Form Solutions with Nonlinear Optimization for Highly Redundant Robotic Systems

    OpenAIRE

    Konietschke, Rainer; Hirzinger, Gerd

    2009-01-01

    This paper presents inverse position kinematics algorithms with real time capability for Justin, a robotic system with high redundancy and many degrees of freedom. The combination of closed form solutions for parts of the kinematic chain embedded in a nonlinear equation solver is shown to be advantageous. The algorithms are evaluated with the DLR service robot Justin both in simulation and reality. Calculation times of 1 ms are achieved, including various optimization criteria for redundancy ...

  7. Common binding by redundant group B Sox proteins is evolutionarily conserved in Drosophila.

    Science.gov (United States)

    Carl, Sarah H; Russell, Steven

    2015-04-13

    Group B Sox proteins are a highly conserved group of transcription factors that act extensively to coordinate nervous system development in higher metazoans while showing both co-expression and functional redundancy across a broad group of taxa. In Drosophila melanogaster, the two group B Sox proteins Dichaete and SoxNeuro show widespread common binding across the genome. While some instances of functional compensation have been observed in Drosophila, the function of common binding and the extent of its evolutionary conservation is not known. We used DamID-seq to examine the genome-wide binding patterns of Dichaete and SoxNeuro in four species of Drosophila. Through a quantitative comparison of Dichaete binding, we evaluated the rate of binding site turnover across the genome as well as at specific functional sites. We also examined the presence of Sox motifs within binding intervals and the correlation between sequence conservation and binding conservation. To determine whether common binding between Dichaete and SoxNeuro is conserved, we performed a detailed analysis of the binding patterns of both factors in two species. We find that, while the regulatory networks driven by Dichaete and SoxNeuro are largely conserved across the drosophilids studied, binding site turnover is widespread and correlated with phylogenetic distance. Nonetheless, binding is preferentially conserved at known cis-regulatory modules and core, independently verified binding sites. We observed the strongest binding conservation at sites that are commonly bound by Dichaete and SoxNeuro, suggesting that these sites are functionally important. Our analysis provides insights into the evolution of group B Sox function, highlighting the specific conservation of shared binding sites and suggesting alternative sources of neofunctionalisation between paralogous family members.

  8. Input relegation control for gross motion of a kinematically redundant manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Unseren, M.A.

    1992-10-01

    This report proposes a method for resolving the kinematic redundancy of a serial link manipulator moving in a three-dimensional workspace. The underspecified problem of solving for the joint velocities based on the classical kinematic velocity model is transformed into a well-specified problem. This is accomplished by augmenting the original model with additional equations which relate a new vector variable quantifying the redundant degrees of freedom (DOF) to the joint velocities. The resulting augmented system yields a well specified solution for the joint velocities. Methods for selecting the redundant DOF quantifying variable and the transformation matrix relating it to the joint velocities are presented so as to obtain a minimum Euclidean norm solution for the joint velocities. The approach is also applied to the problem of resolving the kinematic redundancy at the acceleration level. Upon resolving the kinematic redundancy, a rigid body dynamical model governing the gross motion of the manipulator is derived. A control architecture is suggested which according to the model, decouples the Cartesian space DOF and the redundant DOF.

  9. One size does not fit all: older adults benefit from redundant text in multimedia instruction.

    Science.gov (United States)

    Fenesi, Barbara; Vandermorris, Susan; Kim, Joseph A; Shore, David I; Heisz, Jennifer J

    2015-01-01

    The multimedia design of presentations typically ignores that younger and older adults have varying cognitive strengths and weaknesses. We examined whether differential instructional design may enhance learning in these populations. Younger and older participants viewed one of three computer-based presentations: Audio only (narration), Redundant (audio narration with redundant text), or Complementary (audio narration with non-redundant text and images). Younger participants learned better when audio narration was paired with relevant images compared to when audio narration was paired with redundant text. However, older participants learned best when audio narration was paired with redundant text. Younger adults, who presumably have a higher working memory capacity (WMC), appear to benefit more from complementary information that may drive deeper conceptual processing. In contrast, older adults learn better from presentations that support redundant coding across modalities, which may help mitigate the effects of age-related decline in WMC. Additionally, several misconceptions of design quality appeared across age groups: both younger and older participants positively rated less effective designs. Findings suggest that one-size does not fit all, with older adults requiring unique multimedia design tailored to their cognitive abilities for effective learning.

  10. One Size Does Not Fit All: Older Adults Benefit From Redundant Text in Multimedia Instruction

    Directory of Open Access Journals (Sweden)

    Barbara eFenesi

    2015-07-01

    Full Text Available The multimedia design of presentations typically ignores that younger and older adults have varying cognitive strengths and weaknesses. We examined whether differential instructional design may enhance learning in these populations. Younger and older participants viewed one of three computer-based presentations: Audio only (narration, Redundant (audio narration with redundant text, or Complementary (audio narration with non–redundant text and images. Younger participants learned better when audio narration was paired with relevant images compared to when audio narration was paired with redundant text. However, older participants learned best when audio narration was paired with redundant text. Younger adults, who presumably have a higher working memory capacity, appear to benefit more from complementary information that may drive deeper conceptual processing. In contrast, older adults learn better from presentations that support redundant coding across modalities, which may help mitigate the effects of age-related decline in working memory capacity. Additionally, several misconceptions of design quality appeared across age groups: both younger and older participants positively rated less effective designs. Findings suggest that one-size does not fit all, with older adults requiring unique multimedia design tailored to their cognitive abilities for effective learning.

  11. Developmental changes in children’s processing of redundant modifiers in definite object descriptions

    Directory of Open Access Journals (Sweden)

    Ruud Koolen

    2016-12-01

    Full Text Available This paper investigates developmental changes in children’s processing of redundant information in definite object descriptions. In two experiments, children of two age groups (six or seven, and nine or ten years old were presented with pictures of sweets. In the first experiment (pairwise comparison, two identical sweets were shown, and one of these was described with a redundant modifier. After the description, the children had to indicate the sweet they preferred most in a forced-choice task. In the second experiment (graded rating, only one sweet was shown, which was described with a redundant color modifier in half of the cases (e.g., the blue sweet and in the other half of the cases simply as the sweet. This time, the children were asked to indicate on a 5-point rating scale to what extent they liked the sweets. In both experiments, the results showed that the younger children had a preference for the sweets described with redundant information, while redundant information did not have an effect on the preferences for the older children. These results imply that children are learning to distinguish between situations in which redundant information carries an implicature and situations in which this is not the case.

  12. REDUNDANT ELECTRIC MOTOR DRIVE CONTROL UNIT DESIGN USING AUTOMATA-BASED APPROACH

    Directory of Open Access Journals (Sweden)

    Yuri Yu. Yankin

    2014-11-01

    Full Text Available Implementation of redundant unit for motor drive control based on programmable logic devices is discussed. Continuous redundancy method is used. As compared to segregated standby redundancy and whole system standby redundancy, such method provides preservation of all unit functions in case of redundancy and gives the possibility for continuous monitoring of major and redundant elements. Example of that unit is given. Electric motor drive control channel block diagram contains two control units – the major and redundant; it also contains four power supply units. Control units programming was carried out using automata-based approach. Electric motor drive control channel model was developed; it provides complex simulation of control state-machine and power converter. Through visibility and hierarchy of finite state machines debug time was shortened as compared to traditional programming. Control state-machine description using hardware description language is required for its synthesis with FPGA-devices vendor design software. This description was generated automatically by MATLAB software package. To verify results two prototype control units, two prototype power supply units, and device mock-up were developed and manufactured. Units were installed in the device mock-up. Prototype units were created in accordance with requirements claimed to deliverable hardware. Control channel simulation and tests results in the perfect state and during imitation of major element fault are presented. Automata-based approach made it possible to observe and debug control state-machine transitions during simulation of transient processes, occurring at imitation of faults. Results of this work can be used in development of fault tolerant electric motor drive control channels.

  13. Maximization of Learning Speed Due to Neuronal Redundancy in Reinforcement Learning

    Science.gov (United States)

    Takiyama, Ken

    2016-11-01

    Adaptable neural activity contributes to the flexibility of human behavior, which is optimized in situations such as motor learning and decision making. Although learning signals in motor learning and decision making are low-dimensional, neural activity, which is very high dimensional, must be modified to achieve optimal performance based on the low-dimensional signal, resulting in a severe credit-assignment problem. Despite this problem, the human brain contains a vast number of neurons, leaving an open question: what is the functional significance of the huge number of neurons? Here, I address this question by analyzing a redundant neural network with a reinforcement-learning algorithm in which the numbers of neurons and output units are N and M, respectively. Because many combinations of neural activity can generate the same output under the condition of N ≫ M, I refer to the index N - M as neuronal redundancy. Although greater neuronal redundancy makes the credit-assignment problem more severe, I demonstrate that a greater degree of neuronal redundancy facilitates learning speed. Thus, in an apparent contradiction of the credit-assignment problem, I propose the hypothesis that a functional role of a huge number of neurons or a huge degree of neuronal redundancy is to facilitate learning speed.

  14. Design method of redundancy of brace-anchor sharing supporting based on cooperative deformation

    Science.gov (United States)

    Liu, Jun-yan; Li, Bing; Liu, Yan; Cai, Shan-bing

    2017-11-01

    Because of the complicated environment requirement, the support form of foundation pit is diversified, and the brace-anchor sharing support is widely used. However, the research on the force deformation characteristics and the related aspects of the cooperative response of the brace-anchor sharing support is insufficient. The application of redundancy theory in structural engineering has been more mature, but there is little theoretical research on redundancy theory in underground engineering. Based on the idea of collaborative deformation, the paper calculates the ratio of the redundancy degree of the cooperative deformation by using the local reinforcement design method and the structural component redundancy parameter calculation formula based on Frangopol. Combined with the engineering case, through the calculation of the ratio of cooperative deformation redundancy in the joint of brace-anchor sharing support. This paper explores the optimal anchor distribution form under the condition of cooperative deformation, and through the analysis and research of displacement field and stress field, the results of the collaborative deformation are validated by comparing the field monitoring data. It provides theoretical basis for the design of this kind of foundation pit in the future.

  15. An improved method for calculating self-motion coordinates for redundant manipulators

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.

    1997-04-01

    For a redundant manipulator, the objective of redundancy resolution is to follow a specified path in Cartesian space and simultaneously perform another task (for example, maximize an objective function or avoid obstacles) at every point along the path. The conventional methods have several drawbacks: a new function must be defined for each task, the extended Jacobian can be singular, closed cycles in Cartesian space may not yield closed cycles in joint space, and the objective is point-wise redundancy resolution (to determine a single point in joint space for each point in Cartesian space). The author divides the redundancy resolution problem into two parts: (1) calculate self-motion coordinates for all possible positions of a manipulator at each point along a Cartesian path and (2) determination of optimal self-motion coordinates that maximize an objective function along the path. This paper will discuss the first part of the problem. The path-wise approach overcomes all of the drawbacks of conventional redundancy resolution methods: no need to define a new function for each task, extended Jacobian cannot be singular, and closed cycles in extended Cartesian space will yield closed cycles in joint space.

  16. A Novel Approach Based on Data Redundancy for Feature Extraction of EEG Signals.

    Science.gov (United States)

    Amin, Hafeez Ullah; Malik, Aamir Saeed; Kamel, Nidal; Hussain, Muhammad

    2016-03-01

    Feature extraction and classification for electroencephalogram (EEG) in medical applications is a challenging task. The EEG signals produce a huge amount of redundant data or repeating information. This redundancy causes potential hurdles in EEG analysis. Hence, we propose to use this redundant information of EEG as a feature to discriminate and classify different EEG datasets. In this study, we have proposed a JPEG2000 based approach for computing data redundancy from multi-channels EEG signals and have used the redundancy as a feature for classification of EEG signals by applying support vector machine, multi-layer perceptron and k-nearest neighbors classifiers. The approach is validated on three EEG datasets and achieved high accuracy rate (95-99 %) in the classification. Dataset-1 includes the EEG signals recorded during fluid intelligence test, dataset-2 consists of EEG signals recorded during memory recall test, and dataset-3 has epileptic seizure and non-seizure EEG. The findings demonstrate that the approach has the ability to extract robust feature and classify the EEG signals in various applications including clinical as well as normal EEG patterns.

  17. Emergency response to disaster-struck scale-free network with redundant systems

    Science.gov (United States)

    Ouyang, Min; Yu, Ming-Hui; Huang, Xiang-Zhao; Luan, En-Jie

    2008-07-01

    Disasters cause tremendous damage every year. In this paper, we have specifically studied emergency response to disaster-struck scale-free networks when some nodes in the network have redundant systems. If one node collapses, its redundant system will substitute it to work for a period of time. In the first part, according to the network structure, several redundant strategies have been formulated, and then our studies focused on their effectiveness by means of simulation. Results show that the strategy based on total degrees is the most effective one. However, many nodes still collapse in the end if redundant systems do not have sufficient capability, so emergency responses are necessary. Several emergent strategies controlling the distribution of external resources have been proposed in the second part. The effectiveness of those emergent strategies are then studied from three aspects, such as the effect of strategies on spreading processes, minimum sufficient quantities of external resources and determination of the most appropriate emergent strategy. In addition, the effects of redundant intensity on these aspects have been discussed as well.

  18. Designing Fault Tolerance Strategy by Iterative Redundancy for Component-Based Distributed Computing Systems

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2014-01-01

    Full Text Available Reliability is a critical issue for component-based distributed computing systems, some distributed software allows the existence of large numbers of potentially faulty components on an open network. Faults are inevitable in this large-scale, complex, distributed components setting, which may include a lot of untrustworthy parts. How to provide highly reliable component-based distributed systems is a challenging problem and a critical research. Generally, redundancy and replication are utilized to realize the goal of fault tolerance. In this paper, we propose a CFI (critical fault iterative redundancy technique, by which the efficiency can be guaranteed to make use of resources (e.g., computation and storage and to create fault-tolerance applications. When operating in an environment with unknown components’ reliability, CFI redundancy is more efficient and adaptive than other techniques (e.g., K-Modular Redundancy and N-Version Programming. In the CFI strategy of redundancy, the function invocation relationships and invocation frequencies are employed to rank the functions’ importance and identify the most vulnerable function implemented via functionally equivalent components. A tradeoff has to be made between efficiency and reliability. In this paper, a formal theoretical analysis and an experimental analysis are presented. Compared with the existing methods, the reliability of components-based distributed system can be greatly improved by tolerating a small part of significant components.

  19. Using information theory to identify redundancy in common laboratory tests in the intensive care unit.

    Science.gov (United States)

    Lee, Joon; Maslove, David M

    2015-07-31

    Clinical workflow is infused with large quantities of data, particularly in areas with enhanced monitoring such as the Intensive Care Unit (ICU). Information theory can quantify the expected amounts of total and redundant information contained in a given clinical data type, and as such has the potential to inform clinicians on how to manage the vast volumes of data they are required to analyze in their daily practice. The objective of this proof-of-concept study was to quantify the amounts of redundant information associated with common ICU lab tests. We analyzed the information content of 11 laboratory test results from 29,149 adult ICU admissions in the MIMIC II database. Information theory was applied to quantify the expected amount of redundant information both between lab values from the same ICU day, and between consecutive ICU days. Most lab values showed a decreasing trend over time in the expected amount of novel information they contained. Platelet, blood urea nitrogen (BUN), and creatinine measurements exhibited the most amount of redundant information on days 2 and 3 compared to the previous day. The creatinine-BUN and sodium-chloride pairs had the most redundancy. Information theory can help identify and discourage unnecessary testing and bloodwork, and can in general be a useful data analytic technique for many medical specialties that deal with information overload.

  20. Motion planning for redundant prismatic-jointed manipulators in the free-floating mode

    Science.gov (United States)

    Liu, Xiao-Dong; Baoyin, He-Xi; Ma, Xing-Rui

    2012-10-01

    This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. However, in space, the end-effectors of free-floating manipulators can achieve both the desired orientation and desired position due to the dynamical coupling between manipulator and satellite movement, which is formally expressed by linear and angular momentum conservation laws. In this study, a tractable algorithm particle swarm optimization combined with differential evolution (PSODE) is provided to deal with the motion planning of redundant free-floating prismatic-jointed manipulators, which could avoid the pseudo inverse of the Jacobian matrix. The polynomial functions, as argument in sine functions are used to specify the joint paths. The coefficients of the polynomials are optimized to achieve the desired end-effector orientation and position, and simultaneously minimize the unit-mass-kinetic energy using the redundancy. Relevant simulations prove that this method provides satisfactory smooth paths for redundant free-floating prismatic-jointed manipulators. This study could help to recognize the advantages of redundant prismatic-jointed space manipulators.

  1. Balancing Acts

    Science.gov (United States)

    ... Current Issue Past Issues Special Section: Focus on Communication Balancing Acts Past Issues / Fall 2008 Table of ... It was like watching a movie, but every couple of frames were skipping. It was disorienting," the ...

  2. Real-time neuromorphic algorithms for inverse kinematics of redundant manipulators

    Science.gov (United States)

    Barhen, Jacob; Gulati, Sandeep; Zak, Michail

    1989-01-01

    The paper presents an efficient neuromorphic formulation to accurately solve the inverse kinematics problem for redundant manipulators. The approach involves a dynamical learning procedure based on a novel formalism in neural network theory: the concept of 'terminal' attractors. Topographically mapped terminal attractors are used to define a neural network whose synaptic elements can rapidly encapture the inverse kinematics transformations, and, subsequently generalize to compute joint-space coordinates required to achieve arbitrary end-effector configurations. Unlike prior neuromorphic implementations, this technique can also systematically exploit redundancy to optimize kinematic criteria, e.g., torque optimization. Simulations on 3-DOF and 7-DOF redundant manipulators, are used to validate the theoretical framework and illustrate its computational efficacy.

  3. PSD Camera Based Position and Posture Control of Redundant Robot Considering Contact Motion

    Science.gov (United States)

    Oda, Naoki; Kotani, Kentaro

    The paper describes a position and posture controller design based on the absolute position by external PSD vision sensor for redundant robot manipulator. The redundancy enables a potential capability to avoid obstacle while continuing given end-effector jobs under contact with middle link of manipulator. Under contact motion, the deformation due to joint torsion obtained by comparing internal and external position sensor, is actively suppressed by internal/external position hybrid controller. The selection matrix of hybrid loop is given by the function of the deformation. And the detected deformation is also utilized in the compliant motion controller for passive obstacle avoidance. The validity of the proposed method is verified by several experimental results of 3link planar redundant manipulator.

  4. Message passing for integrating and assessing renewable generation in a redundant power grid

    Energy Technology Data Exchange (ETDEWEB)

    Zdeborova, Lenka [Los Alamos National Laboratory; Backhaus, Scott [Los Alamos National Laboratory; Chertkov, Michael [Los Alamos National Laboratory

    2009-01-01

    A simplified model of a redundant power grid is used to study integration of fluctuating renewable generation. The grid consists of large number of generator and consumer nodes. The net power consumption is determined by the difference between the gross consumption and the level of renewable generation. The gross consumption is drawn from a narrow distribution representing the predictability of aggregated loads, and we consider two different distributions representing wind and solar resources. Each generator is connected to D consumers, and redundancy is built in by connecting R {le} D of these consumers to other generators. The lines are switchable so that at any instance each consumer is connected to a single generator. We explore the capacity of the renewable generation by determining the level of 'firm' generation capacity that can be displaced for different levels of redundancy R. We also develop message-passing control algorithm for finding switch sellings where no generator is overloaded.

  5. Robust Redundant Input Reliable Tracking Control for Omnidirectional Rehabilitative Training Walker

    Directory of Open Access Journals (Sweden)

    Ping Sun

    2014-01-01

    Full Text Available The problem of robust reliable tracking control on the omnidirectional rehabilitative training walker is examined. The new nonlinear redundant input method is proposed when one wheel actuator fault occurs. The aim of the study is to design an asymptotically stable controller that can guarantee the safety of the user and ensure tracking on a training path planned by a physical therapist. The redundant degrees of freedom safety control and the asymptotically zero state detectable concept of the walker are presented, the model of redundant degree is constructed, and the property of center of gravity constant shift is obtained. A controller that can satisfy asymptotic stability is obtained using a common Lyapunov function for admissible uncertainties resulting from an actuator fault. Simulation results confirm the effectiveness of the proposed method and verify that the walker can provide safe sequential motion when one wheel actuator is at fault.

  6. Analytical Redundancy Design for Aeroengine Sensor Fault Diagnostics Based on SROS-ELM

    Directory of Open Access Journals (Sweden)

    Jun Zhou

    2016-01-01

    Full Text Available Analytical redundancy technique is of great importance to guarantee the reliability and safety of aircraft engine system. In this paper, a machine learning based aeroengine sensor analytical redundancy technique is developed and verified through hardware-in-the-loop (HIL simulation. The modified online sequential extreme learning machine, selective updating regularized online sequential extreme learning machine (SROS-ELM, is employed to train the model online and estimate sensor measurements. It selectively updates the output weights of neural networks according to the prediction accuracy and the norm of output weight vector, tackles the problems of singularity and ill-posedness by regularization, and adopts a dual activation function in the hidden nodes combing neural and wavelet theory to enhance prediction capability. The experimental results verify the good generalization performance of SROS-ELM and show that the developed analytical redundancy technique for aeroengine sensor fault diagnosis based on SROS-ELM is effective and feasible.

  7. Conservation of Shannon's redundancy for proteins. [information theory applied to amino acid sequences

    Science.gov (United States)

    Gatlin, L. L.

    1974-01-01

    Concepts of information theory are applied to examine various proteins in terms of their redundancy in natural originators such as animals and plants. The Monte Carlo method is used to derive information parameters for random protein sequences. Real protein sequence parameters are compared with the standard parameters of protein sequences having a specific length. The tendency of a chain to contain some amino acids more frequently than others and the tendency of a chain to contain certain amino acid pairs more frequently than other pairs are used as randomness measures of individual protein sequences. Non-periodic proteins are generally found to have random Shannon redundancies except in cases of constraints due to short chain length and genetic codes. Redundant characteristics of highly periodic proteins are discussed. A degree of periodicity parameter is derived.

  8. Automated Milling Path Tracking and CAM-ROB Integration for Industrial Redundant Manipulators

    Directory of Open Access Journals (Sweden)

    Luis Gracia

    2012-09-01

    Full Text Available The present paper explores the industrial capabilities of a CAM-ROB system implementation based on a commercial CAD/CAM system (NX™ for an industrial robotic workcell of eight joints, committed to the rapid prototyping of 3D CAD-defined models. The workcell consists of a KUKA™ KR15/2 manipulator assembled on a linear track and synchronized with a rotary table. A redundancy resolution scheme is developed to deal with the redundancies due to the additional joints of the robot, plus the one from the symmetry axis of the milling tool. During the path tracking, the use of these redundancies is optimized by adjusting two performance criterion vectors related to singularity avoidance and maintenance of a preferred reference posture, as secondary tasks to be done. In addition, two suitable fuzzy inference engines adjust the weight of each joint in these tasks. The developed system is validated in a real prototyping of a carving.

  9. Multisensory processing of redundant information in go/no-go and choice responses

    DEFF Research Database (Denmark)

    Blurton, Steven Paul; Greenlee, Mark W.; Gondan, Matthias

    2014-01-01

    In multisensory research, faster responses are commonly observed when multimodal stimuli are presented as compared to unimodal target presentations. This so-called redundant signals effect can be explained by several frameworks including separate activation and coactivation models. The redundant...... signals effect has been investigated in a large number of studies; however, most of those studies are limited to the rejection of separate activation models. Coactivation models have been analyzed in only few studies primarily using simple response tasks. Here, we investigated the mechanism...... of multisensory integration underlying go/no-go and choice responses to redundant auditory-visual stimuli. In the present study, mean and variance of response time, as well as accuracy rates of go/no-go and choice responses were used to test a coactivation model based on linear superposition of diffusion...

  10. Fault-Tolerant Region-Based Control of an Underwater Vehicle with Kinematically Redundant Thrusters

    Directory of Open Access Journals (Sweden)

    Zool H. Ismail

    2014-01-01

    Full Text Available This paper presents a new control approach for an underwater vehicle with a kinematically redundant thruster system. This control scheme is derived based on a fault-tolerant decomposition for thruster force allocation and a region control scheme for the tracking objective. Given a redundant thruster system, that is, six or more pairs of thrusters are used, the proposed redundancy resolution and region control scheme determine the number of thruster faults, as well as providing the reference thruster forces in order to keep the underwater vehicle within the desired region. The stability of the presented control law is proven in the sense of a Lyapunov function. Numerical simulations are performed with an omnidirectional underwater vehicle and the results of the proposed scheme illustrate the effectiveness in terms of optimizing the thruster forces.

  11. Resolution of redundant semantic type assignments for organic chemicals in the UMLS.

    Science.gov (United States)

    Morrey, C Paul; Chen, Ling; Halper, Michael; Perl, Yehoshua

    2011-07-01

    The Unified Medical Language System (UMLS) integrates terms from different sources into concepts and supplements these with the assignment of one or more high-level semantic types (STs) from its Semantic Network (SN). For a composite organic chemical concept, multiple assignments of organic chemical STs often serve to enumerate the types of the composite's underlying chemical constituents. This practice sometimes leads to the introduction of a forbidden redundant ST assignment, where both an ST and one of its descendants are assigned to the same concept. A methodology for resolving redundant ST assignments for organic chemicals, better capturing the essence of such composite chemicals than the typical omission of the more general ST, is presented. The typical SN resolution of a redundant ST assignment is to retain only the more specific ST assignment and omit the more general one. However, with organic chemicals, that is not always the correct strategy. A methodology for properly dealing with the redundancy based on the relative sizes of the chemical components is presented. It is more accurate to use the ST of the larger chemical component for capturing the category of the concept, even if that means using the more general ST. A sample of 254 chemical concepts having redundant ST assignments in older UMLS releases was audited to analyze the accuracy of current ST assignments. For 81 (32%) of them, our chemical analysis-based approach yielded a different recommendation from the UMLS (2009AA). New UMLS usage notes capturing rules of this methodology are proffered. Redundant ST assignments have typically arisen for organic composite chemical concepts. A methodology for dealing with this kind of erroneous configuration, capturing the proper category for a composite chemical, is presented and demonstrated. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. A novel redundant INS based on triple rotary inertial measurement units

    Science.gov (United States)

    Chen, Gang; Li, Kui; Wang, Wei; Li, Peng

    2016-10-01

    Accuracy and reliability are two key performances of inertial navigation system (INS). Rotation modulation (RM) can attenuate the bias of inertial sensors and make it possible for INS to achieve higher navigation accuracy with lower-class sensors. Therefore, the conflict between the accuracy and cost of INS can be eased. Traditional system redundancy and recently researched sensor redundancy are two primary means to improve the reliability of INS. However, how to make the best use of the redundant information from redundant sensors hasn’t been studied adequately, especially in rotational INS. This paper proposed a novel triple rotary unit strapdown inertial navigation system (TRUSINS), which combines RM and sensor redundancy design to enhance the accuracy and reliability of rotational INS. Each rotary unit independently rotates to modulate the errors of two gyros and two accelerometers. Three units can provide double sets of measurements along all three axes of body frame to constitute a couple of INSs which make TRUSINS redundant. Experiments and simulations based on a prototype which is made up of six fiber-optic gyros with drift stability of 0.05° h-1 show that TRUSINS can achieve positioning accuracy of about 0.256 n mile h-1, which is ten times better than that of a normal non-rotational INS with the same level inertial sensors. The theoretical analysis and the experimental results show that due to the advantage of the innovative structure, the designed fault detection and isolation (FDI) strategy can tolerate six sensor faults at most, and is proved to be effective and practical. Therefore, TRUSINS is particularly suitable and highly beneficial for the applications where high accuracy and high reliability is required.

  13. Links between metabolic plasticity and functional redundancy in freshwater bacterioplankton communities.

    Science.gov (United States)

    Comte, Jérôme; Fauteux, Lisa; Del Giorgio, Paul A

    2013-01-01

    Metabolic plasticity and functional redundancy are fundamental properties of microbial communities, which shape their response to environmental forcing, and also mediate the relationship between community composition and function. Yet, the actual quantification of these emergent community properties has been elusive, and we thus do not know how they vary across bacterial communities, and their relationship to environmental gradients and to each other. Here we present an experimental framework that allows us to simultaneously quantify metabolic plasticity and functional redundancy in freshwater bacterioplankton communities, and to explore connections that may exists between them. We define metabolic plasticity as the rate of change in single-cell properties (cell wall integrity, cell size, single-cell activity) relative to changes in community composition. Likewise, we define functional redundancy as the rate of change in carbon substrate uptake capacities relative to changes in community composition. We assessed these two key community attributes in transplant experiments where bacterioplankton from various aquatic habitats within the same watershed were transplanted from their original water to waters from other systems that differ in their main resources. Our results show that metabolic plasticity is an intrinsic property of bacterial communities, whereas the expression of functional redundancy appears to be more dependent on environmental factors. Furthermore, there was an overall strong positive relationship between the level of functional redundancy and of metabolic plasticity, suggesting no trade-offs between these community attributes but rather a possible co-selection. The apparent continuum in the expression of both functional redundancy and plasticity among bacterial communities and the link between them, in turn suggest that the link between community diversity and function may also vary along a continuum, from being very tight, to being weak, or absent.

  14. Reliability optimization of series-parallel systems with a choice of redundancy strategies using a genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Tavakkoli-Moghaddam, R. [Department of Industrial Engineering, Faculty of Engineering, University of Tehran, P.O. Box 11365/4563, Tehran (Iran, Islamic Republic of); Department of Mechanical Engineering, The University of British Columbia, Vancouver (Canada)], E-mail: tavakoli@ut.ac.ir; Safari, J. [Department of Industrial Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)], E-mail: jalalsafari@pideco.com; Sassani, F. [Department of Mechanical Engineering, The University of British Columbia, Vancouver (Canada)], E-mail: sassani@mech.ubc.ca

    2008-04-15

    This paper proposes a genetic algorithm (GA) for a redundancy allocation problem for the series-parallel system when the redundancy strategy can be chosen for individual subsystems. Majority of the solution methods for the general redundancy allocation problems assume that the redundancy strategy for each subsystem is predetermined and fixed. In general, active redundancy has received more attention in the past. However, in practice both active and cold-standby redundancies may be used within a particular system design and the choice of the redundancy strategy becomes an additional decision variable. Thus, the problem is to select the best redundancy strategy, component, and redundancy level for each subsystem in order to maximize the system reliability under system-level constraints. This belongs to the NP-hard class of problems. Due to its complexity, it is so difficult to optimally solve such a problem by using traditional optimization tools. It is demonstrated in this paper that GA is an efficient method for solving this type of problems. Finally, computational results for a typical scenario are presented and the robustness of the proposed algorithm is discussed.

  15. Statistical Redundancy Testing for Improved Gene Selection in Cancer Classification Using Microarray Data

    Directory of Open Access Journals (Sweden)

    J. Sunil Rao

    2007-01-01

    Full Text Available In gene selection for cancer classifi cation using microarray data, we define an eigenvalue-ratio statistic to measure a gene’s contribution to the joint discriminability when this gene is included into a set of genes. Based on this eigenvalueratio statistic, we define a novel hypothesis testing for gene statistical redundancy and propose two gene selection methods. Simulation studies illustrate the agreement between statistical redundancy testing and gene selection methods. Real data examples show the proposed gene selection methods can select a compact gene subset which can not only be used to build high quality cancer classifiers but also show biological relevance.

  16. Comparison of Selected Formulations for Multibody System Dynamics with Redundant Constraints

    Directory of Open Access Journals (Sweden)

    Pękal Marcin

    2016-03-01

    Full Text Available This paper compares selected optimization-based methods for the analysis of multibody systems with redundant constraints. The following numerical schemes are examined: direct integration method, Udwadia-Kalaba formulation, two types of least-squares block solution method and Udwadia-Phohomsiri formulation. In order to compare efficiency of the algorithms, a series of simulations is performed on two exemplary McPherson struts. In the first variant, the mechanism has no redundant constraints whereas the other is overconstrained. Three constraint stabilization schemes are also compared in terms of integration errors.

  17. Modeling, Simulation and Control of a Redundant SCARA-Type Manipulator Robot

    Directory of Open Access Journals (Sweden)

    Claudio Urrea

    2012-08-01

    Full Text Available In this paper, the modeling of a redundant SCARA-type manipulator robot with five degrees of freedom is presented. We propose three controllers - hyperbolic sine-cosine, sliding mode, and calculated torque - which are applied to the discussed model. A simulation environment is developed using MatLab/Simulink programming tools. This simulation environment is employed to perform several tests (including actuators' dynamics on the model of the redundant manipulator, with each different controller, under path tracking requirements. Results were obtained from comparative curves and rms index for joints and Cartesian errors.

  18. Design of a developmental dual fail operational redundant strapped down inertial measurement unit

    Science.gov (United States)

    Morrell, F. R.; Russell, J. G.

    1980-01-01

    An experimental redundant strap-down inertial measurement unit (RSDIMU) is being developed at NASA-Langley as a link to satisfy safety and reliability considerations in the integrated avionics concept. The unit consists of four two-degrees-of-freedom (TDOF) tuned-rotor gyros, and four TDOF pendulous accelerometers in a skewed and separable semi-octahedron array. The system will be used to examine failure detection and isolation techniques, redundancy management rules, and optimal threshold levels for various flight configurations. The major characteristics of the RSDIMU hardware and software design, and its use as a research tool are described.

  19. Description of a dual fail operational redundant strapdown inertial measurement unit for integrated avionics systems research

    Science.gov (United States)

    Bryant, W. H.; Morrell, F. R.

    1981-01-01

    An experimental redundant strapdown inertial measurement unit (RSDIMU) is developed as a link to satisfy safety and reliability considerations in the integrated avionics concept. The unit includes four two degree-of-freedom tuned rotor gyros, and four accelerometers in a skewed and separable semioctahedral array. These sensors are coupled to four microprocessors which compensate sensor errors. These microprocessors are interfaced with two flight computers which process failure detection, isolation, redundancy management, and general flight control/navigation algorithms. Since the RSDIMU is a developmental unit, it is imperative that the flight computers provide special visibility and facility in algorithm modification.

  20. A two-phase linear programming approach for redundancy allocation problems

    Directory of Open Access Journals (Sweden)

    Hsieh Yi-Chih

    2002-01-01

    Full Text Available Provision of redundant components in parallel is an efficient way to increase the system reliability, however, the weight, volume and cost of the system will increase simultaneously. This paper proposes a new two-phase linear programming approach for solving the nonlinear redundancy allocation problems subject to multiple linear constraints. The first phase is used to approximately allocate the resource by using a general linear programming, while the second phase is used to re-allocate the slacks of resource by using a 0-1 integer linear programming. Numerical results demonstrate the effectiveness and efficiency of the proposed approach.

  1. Dual-PLL based on Temporal Redundancy for Radiation-Hardening

    OpenAIRE

    Kim, SinNyoung; Tsuchiya, Akira; Onodera, Hidetoshi

    2013-01-01

    This paper proposes a dual-PLL based on temporal redundancy for radiation-hardening. A common practice technique for radiation-hardening is the triple modular redundancy (TMR). However, it is inefficient to apply for PLLs because PLLs include huge size of capacitance and static current consumers, means analog circuits. Thus, we propose a dual-PLL and a detective circuit that detects a perturbed PLL by radiation-strike. Although our proposal is based on DMR, it allows both detecting and correc...

  2. Low voltage main distribution with redundant feeding; Niederspannungshauptverteilung mit redundanter Einspeisung

    Energy Technology Data Exchange (ETDEWEB)

    Schell, Michael [Rittal GmbH und Co. KG, Herborn (Germany). Produktmanagement Power Distribution; Koch, Hans-Robert [Rittal GmbH und Co. KG, Herborn (Germany). Presse- und Oeffentlichkeitsarbeit

    2012-08-15

    Low voltage switching stations for power plants must operate without interruption. Therefore, these switchgears often are built up redundantly. A lignite power plant in Central Europe commissioned the medium-sized company A+H Steuer- und Regeltechnik (Remscheid, Federal Republic of Germany) to build a low-voltage switching station in which the supply redundantly is realized by means of two transformers. The main feeders and the switching network place high demands on design, construction and installation. The complex requirements were fulfilled using the solution kit 'Ri4Power' and the engineering tool 'Power Engineering' from Rittal easily and quickly fulfilled.

  3. WISC-R and WISC: A Study of Redundancy and Structural Comparability.

    Science.gov (United States)

    Rowe, Helga A. H.

    The Wechsler Intelligence Scale for Children - Revised (WISC-R) and the Wechsler Intelligence Scale for Children (WISC) were administered in counter-balanced order to 81 children aged 7-12 in New South Wales, Australia. Canonical correlation analysis showed the total redundancy values of WISC-R given WISC and WISC given WISC-R to be .58 and .61…

  4. Flux analysis uncovers key role of functional redundancy in formaldehyde metabolism.

    Directory of Open Access Journals (Sweden)

    Christopher J Marx

    2005-02-01

    Full Text Available Genome-scale analysis of predicted metabolic pathways has revealed the common occurrence of apparent redundancy for specific functional units, or metabolic modules. In many cases, mutation analysis does not resolve function, and instead, direct experimental analysis of metabolic flux under changing conditions is necessary. In order to use genome sequences to build models of cellular function, it is important to define function for such apparently redundant systems. Here we describe direct flux measurements to determine the role of redundancy in three modules involved in formaldehyde assimilation and dissimilation in a bacterium growing on methanol. A combination of deuterium and (14C labeling was used to measure the flux through each of the branches of metabolism for growth on methanol during transitions into and out of methylotrophy. The cells were found to differentially partition formaldehyde among the three modules depending on the flux of methanol into the cell. A dynamic mathematical model demonstrated that the kinetic constants of the enzymes involved are sufficient to account for this phenomenon. We demonstrate the role of redundancy in formaldehyde metabolism and have uncovered a new paradigm for coping with toxic, high-flux metabolic intermediates: a dynamic, interconnected metabolic loop.

  5. Efficiency improvement in redundant power systems by means of thermal load sharing

    DEFF Research Database (Denmark)

    Nesgaard, Carsten; Andersen, Michael Andreas E.

    2004-01-01

    The demand for higher output currents at ever lower voltage levels is often solved by paralleling multiple converters. Provided redundancy is implemented this technique, besides being relatively easy to implement, has the advantage of improving the overall system reliability. Also, the parallel-c...

  6. Redundant sensory information does not enhance sequence learning in the serial task

    NARCIS (Netherlands)

    Abrahamse, E.L.; van der Lubbe, Robert Henricus Johannes; Verwey, Willem B.; Szumska, I.; Jaskowski, P.

    2012-01-01

    In daily life we encounter multiple sources of sensory information at any given moment. Unknown is whether such sensory redundancy in some way affects implicit learning of a sequence of events. In the current paper we explored this issue in a serial reaction time task. Our results indicate that

  7. Refinement of light-responsive transcript lists using rice oligonucleotide arrays: evaluation of gene-redundancy.

    Science.gov (United States)

    Jung, Ki-Hong; Dardick, Christopher; Bartley, Laura E; Cao, Peijian; Phetsom, Jirapa; Canlas, Patrick; Seo, Young-Su; Shultz, Michael; Ouyang, Shu; Yuan, Qiaoping; Frank, Bryan C; Ly, Eugene; Zheng, Li; Jia, Yi; Hsia, An-Ping; An, Kyungsook; Chou, Hui-Hsien; Rocke, David; Lee, Geun Cheol; Schnable, Patrick S; An, Gynheung; Buell, C Robin; Ronald, Pamela C

    2008-10-06

    Studies of gene function are often hampered by gene-redundancy, especially in organisms with large genomes such as rice (Oryza sativa). We present an approach for using transcriptomics data to focus functional studies and address redundancy. To this end, we have constructed and validated an inexpensive and publicly available rice oligonucleotide near-whole genome array, called the rice NSF45K array. We generated expression profiles for light- vs. dark-grown rice leaf tissue and validated the biological significance of the data by analyzing sources of variation and confirming expression trends with reverse transcription polymerase chain reaction. We examined trends in the data by evaluating enrichment of gene ontology terms at multiple false discovery rate thresholds. To compare data generated with the NSF45K array with published results, we developed publicly available, web-based tools (www.ricearray.org). The Oligo and EST Anatomy Viewer enables visualization of EST-based expression profiling data for all genes on the array. The Rice Multi-platform Microarray Search Tool facilitates comparison of gene expression profiles across multiple rice microarray platforms. Finally, we incorporated gene expression and biochemical pathway data to reduce the number of candidate gene products putatively participating in the eight steps of the photorespiration pathway from 52 to 10, based on expression levels of putatively functionally redundant genes. We confirmed the efficacy of this method to cope with redundancy by correctly predicting participation in photorespiration of a gene with five paralogs. Applying these methods will accelerate rice functional genomics.

  8. Learning contrast-invariant cancellation of redundant signals in neural systems.

    Directory of Open Access Journals (Sweden)

    Jorge F Mejias

    Full Text Available Cancellation of redundant information is a highly desirable feature of sensory systems, since it would potentially lead to a more efficient detection of novel information. However, biologically plausible mechanisms responsible for such selective cancellation, and especially those robust to realistic variations in the intensity of the redundant signals, are mostly unknown. In this work, we study, via in vivo experimental recordings and computational models, the behavior of a cerebellar-like circuit in the weakly electric fish which is known to perform cancellation of redundant stimuli. We experimentally observe contrast invariance in the cancellation of spatially and temporally redundant stimuli in such a system. Our model, which incorporates heterogeneously-delayed feedback, bursting dynamics and burst-induced STDP, is in agreement with our in vivo observations. In addition, the model gives insight on the activity of granule cells and parallel fibers involved in the feedback pathway, and provides a strong prediction on the parallel fiber potentiation time scale. Finally, our model predicts the existence of an optimal learning contrast around 15% contrast levels, which are commonly experienced by interacting fish.

  9. Global Energy-Optimal Redundancy Resolution of Hydraulic Manipulators: Experimental Results for a Forestry Manipulator

    Directory of Open Access Journals (Sweden)

    Jarmo Nurmi

    2017-05-01

    Full Text Available This paper addresses the energy-inefficiency problem of four-degrees-of-freedom (4-DOF hydraulic manipulators through redundancy resolution in robotic closed-loop controlled applications. Because conventional methods typically are local and have poor performance for resolving redundancy with respect to minimum hydraulic energy consumption, global energy-optimal redundancy resolution is proposed at the valve-controlled actuator and hydraulic power system interaction level. The energy consumption of the widely popular valve-controlled load-sensing (LS and constant-pressure (CP systems is effectively minimised through cost functions formulated in a discrete-time dynamic programming (DP approach with minimum state representation. A prescribed end-effector path and important actuator constraints at the position, velocity and acceleration levels are also satisfied in the solution. Extensive field experiments performed on a forestry hydraulic manipulator demonstrate the performance of the proposed solution. Approximately 15–30% greater hydraulic energy consumption was observed with the conventional methods in the LS and CP systems. These results encourage energy-optimal redundancy resolution in future robotic applications of hydraulic manipulators.

  10. Syllables and Bigrams: Orthographic Redundancy and Syllabic Units Affect Visual Word Recognition at Different Processing Levels

    Science.gov (United States)

    Conrad, Markus; Carreiras, Manuel; Tamm, Sascha; Jacobs, Arthur M.

    2009-01-01

    Over the last decade, there has been increasing evidence for syllabic processing during visual word recognition. If syllabic effects prove to be independent from orthographic redundancy, this would seriously challenge the ability of current computational models to account for the processing of polysyllabic words. Three experiments are presented to…

  11. Intersensory Redundancy Hinders Face Discrimination in Preschool Children: Evidence for Visual Facilitation

    Science.gov (United States)

    Bahrick, Lorraine E.; Krogh-Jespersen, Sheila; Argumosa, Melissa A.; Lopez, Hassel

    2014-01-01

    Although infants and children show impressive face-processing skills, little research has focused on the conditions that facilitate versus impair face perception. According to the intersensory redundancy hypothesis (IRH), face discrimination, which relies on detection of visual featural information, should be impaired in the context of…

  12. Quantifying the value of redundant measurements at GCOS Reference Upper-Air Network sites

    Science.gov (United States)

    Madonna, F.; Rosoldi, M.; Güldner, J.; Haefele, A.; Kivi, R.; Cadeddu, M. P.; Sisterson, D.; Pappalardo, G.

    2014-11-01

    The potential for measurement redundancy to reduce uncertainty in atmospheric variables has not been investigated comprehensively for climate observations. We evaluated the usefulness of entropy and mutual correlation concepts, as defined in information theory, for quantifying random uncertainty and redundancy in time series of the integrated water vapour (IWV) and water vapour mixing ratio profiles provided by five highly instrumented GRUAN (GCOS, Global Climate Observing System, Reference Upper-Air Network) stations in 2010-2012. Results show that the random uncertainties on the IWV measured with radiosondes, global positioning system, microwave and infrared radiometers, and Raman lidar measurements differed by less than 8%. Comparisons of time series of IWV content from ground-based remote sensing instruments with in situ soundings showed that microwave radiometers have the highest redundancy with the IWV time series measured by radiosondes and therefore the highest potential to reduce the random uncertainty of the radiosondes time series. Moreover, the random uncertainty of a time series from one instrument can be reduced by ~ 60% by constraining the measurements with those from another instrument. The best reduction of random uncertainty is achieved by conditioning Raman lidar measurements with microwave radiometer measurements. Specific instruments are recommended for atmospheric water vapour measurements at GRUAN sites. This approach can be applied to the study of redundant measurements for other climate variables.

  13. Microsatellite-aided detection of genetic redundancy improves management of the International Cocoa Genebank, Trinidad

    Science.gov (United States)

    Cacao (Theobroma cacao L.), the tree from which cocoa butter and chocolate is derived, is conserved in field genebanks. The largest of these ex situ collections in the public domain is the International Cocoa Genebank, Trinidad (ICG,T). Reduction of genetic redundancy is essential to improve the acc...

  14. Optimal configuration of redundant inertial sensors for navigation and FDI performance.

    Science.gov (United States)

    Shim, Duk-Sun; Yang, Cheol-Kwan

    2010-01-01

    This paper considers the optimal sensor configuration for inertial navigation systems which have redundant inertial sensors such as gyroscopes and accelerometers. We suggest a method to determine the optimal sensor configuration which considers both the navigation and FDI performance. Monte Carlo simulations are performed to show the performance of the suggested optimal sensor configuration method.

  15. Optimal Configuration of Redundant Inertial Sensors for Navigation and FDI Performance

    Science.gov (United States)

    Shim, Duk-Sun; Yang, Cheol-Kwan

    2010-01-01

    This paper considers the optimal sensor configuration for inertial navigation systems which have redundant inertial sensors such as gyroscopes and accelerometers. We suggest a method to determine the optimal sensor configuration which considers both the navigation and FDI performance. Monte Carlo simulations are performed to show the performance of the suggested optimal sensor configuration method. PMID:22163563

  16. Reducing animal sequencing redundancy by preferentially selecting animals with low-frequency haplotypes

    Science.gov (United States)

    Many studies leverage targeted whole genome sequencing (WGS) experiments in order to identify rare and causal variants within populations. As a natural consequence of experimental design, many of these surveys tend to sequence redundant haplotype segments due to high frequency in the base population...

  17. Optimal Configuration of Redundant Inertial Sensors for Navigation and FDI Performance

    Directory of Open Access Journals (Sweden)

    Duk-Sun Shim

    2010-07-01

    Full Text Available This paper considers the optimal sensor configuration for inertial navigation systems which have redundant inertial sensors such as gyroscopes and accelerometers. We suggest a method to determine the optimal sensor configuration which considers both the navigation and FDI performance. Monte Carlo simulations are performed to show the performance of the suggested optimal sensor configuration method.

  18. Integrated Stiffness Analysis of Redundant Parallel Manipulator Based on Finite Element Method

    NARCIS (Netherlands)

    Wang, S.; Cheng, G.; Pang, Y.; Lodewijks, G.

    2015-01-01

    An integrated stiffness model is established for a Planar Parallel Manipulator (PPM) with actuation redundancy based on Finite Element Method (FEM), and the static stiffness, dynamitic stiffness and moving stiffness of the PPM are analyzed according to the integrated stiffness model. Firstly, a

  19. Exploiting Redundancy for Flexible Behavior: Unsupervised Learning in a Modular Sensorimotor Control Architecture

    Science.gov (United States)

    Butz, Martin V.; Herbort, Oliver; Hoffmann, Joachim

    2007-01-01

    Autonomously developing organisms face several challenges when learning reaching movements. First, motor control is learned unsupervised or self-supervised. Second, knowledge of sensorimotor contingencies is acquired in contexts in which action consequences unfold in time. Third, motor redundancies must be resolved. To solve all 3 of these…

  20. The Concept of Redundancy in Television Learning Research: Questions of Meaning.

    Science.gov (United States)

    Hanson, LuEtt

    1992-01-01

    Criticizes past research on redundancy in television learning for its inconsistent definitions and ambiguous examples. Four areas of concern are considered: the meaning and use of the term; the nature of signs (iconic or digital) used in audio and visual communication; the subjectivity of interpretation; and differences in meaning between separate…

  1. Efficient redundancy? : How socio-cognitive structures impact innovation under complex conditions

    NARCIS (Netherlands)

    Candiani, Juan; Markus, A.

    2017-01-01

    Building on the knowledge-based view of the firm and organizational design perspective we explore how socio-cognitive structures within organizations impact the success of recombinant innovation. We introduce the efficiency- redundancy paradox – knowledge creation requires efficient internal

  2. The regulation of Arabidopsis thaliana lateral root development by redundant PLETHORA transcription factors

    NARCIS (Netherlands)

    Du, Y.

    2017-01-01

    In Arabidopsis thaliana, lateral roots (LRs) initiate acropetally and their dynamic development forms the basis on which root system architecture is elaborated. This thesis work focuses on revealing the underlying molecular network of how redundant PLETHORA (PLT) genes, encode APETALA2 (AP2)-domain

  3. Split-Attention and Redundancy Effects on Mobile Learning in Physical Environments

    Science.gov (United States)

    Liu, Tzu-Chien; Lin, Yi-Chun; Tsai, Meng-Jung; Paas, Fred

    2012-01-01

    This study investigated split-attention and redundancy effects in a mobile learning environment on leaf morphology of plants as a function of different combinations of media. Eighty-one fifth-grade students were randomly assigned to the following three conditions: texts with pictures embedded in the mobile device (TP condition); texts embedded in…

  4. The Redundancy Effect on Retention and Transfer for Individuals with High Symptoms of ADHD

    Science.gov (United States)

    Brown, Victoria; Lewis, David; Toussaint, Mario

    2016-01-01

    The multimedia elements of text and audio need to be carefully integrated together to maximize the impact of those elements for learning in a multimedia environment. Redundancy information presented through audio and visual channels can inhibit learning for individuals diagnosed with ADHD, who may experience challenges in the processing of…

  5. Performance-Effective and Low-Complexity Redundant Reader Detection in Wireless RFID Networks

    Directory of Open Access Journals (Sweden)

    Kang Heau-Jo

    2008-01-01

    Full Text Available Abstract The problems of redundant RFID reader detection and coverage have instigated researchers to propose different optimization heuristics due to the rapid advance of technologies in large-scale RFID systems. In this paper, we present a layered elimination optimization (LEO which is an algorithm-independent technique aims to detect maximum amount of redundant readers that could be safely removed or turned off with preserving original RFID network coverage. A significant improvement of the LEO scheme is that amount of "write-to-tag" operations could be largely reduced during the redundant reader identification phase. Moreover, LEO is a distributed approach which does not need to collect global information for centralizing control, leading to no communications or synchronizations among RFID readers. To evaluate the performance of the proposed techniques, we have implemented the LEO technique along with other methods. Both theoretical analysis and experimental results show that the LEO is reliable, effective, and efficient. The proposed techniques can provide reliable performance with detecting higher redundancy and has lower algorithm overheads.

  6. Performance-Effective and Low-Complexity Redundant Reader Detection in Wireless RFID Networks

    Directory of Open Access Journals (Sweden)

    Heau-Jo Kang

    2008-05-01

    Full Text Available The problems of redundant RFID reader detection and coverage have instigated researchers to propose different optimization heuristics due to the rapid advance of technologies in large-scale RFID systems. In this paper, we present a layered elimination optimization (LEO which is an algorithm-independent technique aims to detect maximum amount of redundant readers that could be safely removed or turned off with preserving original RFID network coverage. A significant improvement of the LEO scheme is that amount of “write-to-tag” operations could be largely reduced during the redundant reader identification phase. Moreover, LEO is a distributed approach which does not need to collect global information for centralizing control, leading to no communications or synchronizations among RFID readers. To evaluate the performance of the proposed techniques, we have implemented the LEO technique along with other methods. Both theoretical analysis and experimental results show that the LEO is reliable, effective, and efficient. The proposed techniques can provide reliable performance with detecting higher redundancy and has lower algorithm overheads.

  7. Developmental Changes in Children’s Processing of Redundant Modifiers in Definite Object Descriptions

    NARCIS (Netherlands)

    Koolen, Ruud; Krahmer, Emiel; Swerts, Marc

    2016-01-01

    This paper investigates developmental changes in children’s processing of redundant information in definite object descriptions. In two experiments, children of two age groups (6 or 7, and 9 or 10 years old) were presented with pictures of sweets. In the first experiment (pairwise comparison), two

  8. Redundancy gains in simple responses and go/no-go tasks

    DEFF Research Database (Denmark)

    Gondan, Matthias; Götze, C.; Greenlee, M.W.

    2010-01-01

    In divided-attention tasks with two classes of target stimuli, participants typically respond more quickly if both targets are presented simultaneously, as compared with single-target presentation (redundant-signals effect). Different explanations exist for this effect, including serial, parallel......-specific information processing. Supplemental materials for this article may be downloaded from http://app.psychonomic-journals.org/content/supplemental....

  9. Fonction Expressive, Redondance et Arbitrarite du Signe (Expressive Function, Redundancy and the Arbitrariness of the Sign)

    Science.gov (United States)

    Schon, Jacqueline

    1974-01-01

    This article examines the notion of sign on various levels, concluding that which pertains to the linguistic level is pertinent; that which pertains to the expressive level is redundant. The notions of connotation and denotation are discussed. (Text is in French.) (AM)

  10. Quantifying the value of redundant measurements at GCOS Reference Upper-Air Network sites

    Directory of Open Access Journals (Sweden)

    F. Madonna

    2014-11-01

    Full Text Available The potential for measurement redundancy to reduce uncertainty in atmospheric variables has not been investigated comprehensively for climate observations. We evaluated the usefulness of entropy and mutual correlation concepts, as defined in information theory, for quantifying random uncertainty and redundancy in time series of the integrated water vapour (IWV and water vapour mixing ratio profiles provided by five highly instrumented GRUAN (GCOS, Global Climate Observing System, Reference Upper-Air Network stations in 2010–2012. Results show that the random uncertainties on the IWV measured with radiosondes, global positioning system, microwave and infrared radiometers, and Raman lidar measurements differed by less than 8%. Comparisons of time series of IWV content from ground-based remote sensing instruments with in situ soundings showed that microwave radiometers have the highest redundancy with the IWV time series measured by radiosondes and therefore the highest potential to reduce the random uncertainty of the radiosondes time series. Moreover, the random uncertainty of a time series from one instrument can be reduced by ~ 60% by constraining the measurements with those from another instrument. The best reduction of random uncertainty is achieved by conditioning Raman lidar measurements with microwave radiometer measurements. Specific instruments are recommended for atmospheric water vapour measurements at GRUAN sites. This approach can be applied to the study of redundant measurements for other climate variables.

  11. Arabidopsis DOF transcription factors act redundantly to reduce CONSTANS expression and are essential for a photoperiodic flowering response.

    Science.gov (United States)

    Fornara, Fabio; Panigrahi, Kishore C S; Gissot, Lionel; Sauerbrunn, Nicolas; Rühl, Mark; Jarillo, José A; Coupland, George

    2009-07-01

    Flowering of Arabidopsis is induced by long summer days (LDs). The transcriptional regulator CONSTANS (CO) promotes flowering, and its transcription is increased under LDs. We systematically misexpressed transcription factors in companion cells and identified several DOF proteins that delay flowering by repressing CO transcription. Combining mutations in four of these, including CYCLING DOF FACTOR 2 (CDF2), caused photoperiod-insensitive early flowering by increasing CO mRNA levels. CO transcription is promoted to differing extents by GIGANTEA (GI) and the F-box protein FKF1. We show that GI stabilizes FKF1, thereby reducing CDF2 abundance and allowing transcription of CO. Despite the crucial function of GI in wild-type plants, introducing mutations in the four DOF-encoding genes into gi mutants restored the diurnal rhythm and light inducibility of CO. Thus, antagonism between GI and DOF transcription factors contributes to photoperiodic flowering by modulating an underlying diurnal rhythm in CO transcript levels.

  12. Functionally redundant RXLR effectors from Phytophthora infestans act at different steps to suppress early flg22-triggered immunity.

    Directory of Open Access Journals (Sweden)

    Xiangzi Zheng

    2014-04-01

    Full Text Available Genome sequences of several economically important phytopathogenic oomycetes have revealed the presence of large families of so-called RXLR effectors. Functional screens have identified RXLR effector repertoires that either compromise or induce plant defense responses. However, limited information is available about the molecular mechanisms underlying the modes of action of these effectors in planta. The perception of highly conserved pathogen- or microbe-associated molecular patterns (PAMPs/MAMPs, such as flg22, triggers converging signaling pathways recruiting MAP kinase cascades and inducing transcriptional re-programming, yielding a generic anti-microbial response. We used a highly synchronizable, pathogen-free protoplast-based assay to identify a set of RXLR effectors from Phytophthora infestans (PiRXLRs, the causal agent of potato and tomato light blight that manipulate early stages of flg22-triggered signaling. Of thirty-three tested PiRXLR effector candidates, eight, called Suppressor of early Flg22-induced Immune response (SFI, significantly suppressed flg22-dependent activation of a reporter gene under control of a typical MAMP-inducible promoter (pFRK1-Luc in tomato protoplasts. We extended our analysis to Arabidopsis thaliana, a non-host plant species of P. infestans. From the aforementioned eight SFI effectors, three appeared to share similar functions in both Arabidopsis and tomato by suppressing transcriptional activation of flg22-induced marker genes downstream of post-translational MAP kinase activation. A further three effectors interfere with MAMP signaling at, or upstream of, the MAP kinase cascade in tomato, but not in Arabidopsis. Transient expression of the SFI effectors in Nicotiana benthamiana enhances susceptibility to P. infestans and, for the most potent effector, SFI1, nuclear localization is required for both suppression of MAMP signaling and virulence function. The present study provides a framework to decipher the molecular mechanisms underlying the manipulation of host MAMP-triggered immunity (MTI by P. infestans and to understand the basis of host versus non-host resistance in plants towards P. infestans.

  13. Control of Redundant Kinematic Degrees of Freedom in a Closed-Loop Brain-Machine Interface.

    Science.gov (United States)

    Moorman, Helene G; Gowda, Suraj; Carmena, Jose M

    2017-06-01

    Brain-machine interface (BMI) systems use signals acquired from the brain to directly control the movement of an actuator, such as a computer cursor or a robotic arm, with the goal of restoring motor function lost due to injury or disease of the nervous system. In BMIs with kinematically redundant actuators, the combination of the task goals and the system under neural control can allow for many equally optimal task solutions. The extent to which kinematically redundant degrees of freedom (DOFs) in a BMI system may be under direct neural control is unknown. To address this question, a Kalman filter was used to decode single- and multi-unit cortical neural activity of two macaque monkeys into the joint velocities of a virtual four-link kinematic chain. Subjects completed movements of the chain's endpoint to instructed target locations within a two-dimensional plane. This system was kinematically redundant for an endpoint movement task, as four DOFs were used to manipulate the 2-D endpoint position. Both subjects successfully performed the task and improved with practice by producing faster endpoint velocity control signals. Kinematic redundancy allowed null movements whereby the individual links of the chain could move in a way that cancels out and does not result in endpoint movement. As the subjects became more proficient at controlling the chain, the amount of null movement also increased. Task performance suffered when the links of the kinematic chain were hidden and only the endpoint was visible. Furthermore, all four DOFs of the joint-velocity control space exhibited task-relevant modulation. The relative usage of each DOF depended on the configuration of the chain, and trials in which the less-prominent DOFs were utilized also had better task performance. Overall, these results indicate that the subjects incorporated the redundant components of the control space into their control strategy. Future BMI systems with kinematic redundancy, such as exoskeletal

  14. Evaluation of software based redundancy algorithms for the EOS storage system at CERN

    Science.gov (United States)

    Peters, Andreas-Joachim; Alin Sindrilaru, Elvin; Zigann, Philipp

    2012-12-01

    EOS is a new disk based storage system used in production at CERN since autumn 2011. It is implemented using the plug-in architecture of the XRootD software framework and allows remote file access via XRootD protocol or POSIX-like file access via FUSE mounting. EOS was designed to fulfill specific requirements of disk storage scalability and IO scheduling performance for LHC analysis use cases. This is achieved by following a strategy of decoupling disk and tape storage as individual storage systems. A key point of the EOS design is to provide high availability and redundancy of files via a software implementation which uses disk-only storage systems without hardware RAID arrays. All this is aimed at reducing the overall cost of the system and also simplifying the operational procedures. This paper presents the advantages and disadvantages of redundancy by hardware (most classical storage installations) in comparison to redundancy by software. The latter is implemented in the EOS system and achieves its goal by spawning data and parity stripes via remote file access over nodes. The gain in redundancy and reliability comes with a trade-off in the following areas: • Increased complexity of the network connectivity • CPU intensive parity computations during file creation and recovery • Performance loss through remote disk coupling An evaluation and performance figures of several redundancy algorithms are presented for dual parity RAID and Reed-Solomon codecs. Moreover, the characteristics and applicability of these algorithms are discussed in the context of reliable data storage systems.

  15. Introducing "biophysical redundancy": the global status and past evolution of unused water, land and productivity resources for food production

    Science.gov (United States)

    Fader, Marianela

    2017-04-01

    Countries have different resilience to sudden and long-term changes in food demand and supply. An important part of this resilience is the degree of biophysical redundancy, defined as the potential food production of 'spare land', available water resources (i.e., not already used for human activities), as well as production increases through yield gap closure on cultivated areas and potential agricultural areas. The presentation will show the results of a recently published paper1 on the evolution of biophysical redundancy for agricultural production at country level, from 1992 to 2012. Results indicate that in 2012, the biophysical redundancy of 75 (48) countries, mainly in North Africa, Western Europe, the Middle East and Asia, was insufficient to produce the caloric nutritional needs for at least 50% (25%) of their population during a year. Biophysical redundancy has decreased in the last two decades in 102 out of 155 countries, 11 of these went from high to limited redundancy, and nine of these from limited to very low redundancy. Although the variability of the drivers of change across different countries is high, improvements in yield and population growth have a clear impact on the decreases of redundancy towards the very low redundancy category. We took a more detailed look at countries classified as 'Low Income Economies (LIEs)' since they are particularly vulnerable to domestic or external food supply changes, due to their limited capacity to offset for food supply decreases with higher purchasing power on the international market. Currently, nine LIEs have limited or very low biophysical redundancy. Many of these showed a decrease in redundancy over the last two decades, which is not always linked with improvements in per capita food availability.

  16. A Lower-Bound for the Maximin Redundancy in Pattern Coding

    Directory of Open Access Journals (Sweden)

    Aurélien Garivier

    2009-10-01

    Full Text Available We show that the maximin average redundancy in pattern coding is eventually larger than 1.84 (n/log n1/3 for messages of length n. This improves recent results on pattern redundancy, although it does not fill the gap between known lower- and upper-bounds. The pattern of a string is obtained by replacing each symbol by the index of its first occurrence. The problem of pattern coding is of interest because strongly universal codes have been proved to exist for patterns while universal message coding is impossible for memoryless sources on an infinite alphabet. The proof uses fine combinatorial results on partitions with small summands.

  17. The theory of diversity and redundancy in information system security : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, Jackson R. (Sandia National Laboratories, Livermore, CA); Torgerson, Mark Dolan; Walker, Andrea Mae; Armstrong, Robert C. (Sandia National Laboratories, Livermore, CA); Allan, Benjamin A. (Sandia National Laboratories, Livermore, CA); Pierson, Lyndon George

    2010-10-01

    The goal of this research was to explore first principles associated with mixing of diverse implementations in a redundant fashion to increase the security and/or reliability of information systems. Inspired by basic results in computer science on the undecidable behavior of programs and by previous work on fault tolerance in hardware and software, we have investigated the problem and solution space for addressing potentially unknown and unknowable vulnerabilities via ensembles of implementations. We have obtained theoretical results on the degree of security and reliability benefits from particular diverse system designs, and mapped promising approaches for generating and measuring diversity. We have also empirically studied some vulnerabilities in common implementations of the Linux operating system and demonstrated the potential for diversity to mitigate these vulnerabilities. Our results provide foundational insights for further research on diversity and redundancy approaches for information systems.

  18. Quantum Darwinism in an Everyday Environment: Huge Redundancy in Scattered Photons

    Science.gov (United States)

    Riedel, Charles; Zurek, Wojciech

    2011-03-01

    We study quantum Darwinism---the redundant recording of information about the preferred states of a decohering system by its environment---for an object illuminated by a blackbody. In the cases of point-source, small disk, and isotropic illumination, we calculate the quantum mutual information between the object and its photon environment. We demonstrate that this realistic model exhibits fast and extensive proliferation of information about the object into the environment and results in redundancies orders of magnitude larger than the exactly soluble models considered to date. We also demonstrate a reduced ability to create records as initial environmental mixedness increases, in agreement with previous studies. This research is supported by the U.S. Department of Energy through the LANL/LDRD program and, in part, by the Foundational Questions Institute (FQXi).

  19. Redundant imprinting of information in non-ideal environments: Quantum Darwinism via a noisy channel

    Science.gov (United States)

    Zwolak, Michael; Quan, Haitao; Zurek, Wojciech

    2011-03-01

    Quantum Darwinism provides an information-theoretic framework for the emergence of the classical world from the quantum substrate. It recognizes that we - the observers - acquire our information about the ``systems of interest'' indirectly from their imprints on the environment. Objectivity, a key property of the classical world, arises via the proliferation of redundant information into the environment where many observers can then intercept it and independently determine the state of the system. While causing a system to decohere, environments that remain nearly invariant under the Hamiltonian dynamics, such as very mixed states, have a diminished ability to transmit information about the system, yet can still acquire redundant information about the system [1,2]. Our results show that Quantum Darwinism is robust with respect to non-ideal initial states of the environment. This research is supported by the U.S. Department of Energy through the LANL/LDRD Program.

  20. The rise and fall of redundancy in decoherence and quantum Darwinism

    Science.gov (United States)

    Jess Riedel, C.; Zurek, Wojciech H.; Zwolak, Michael

    2012-08-01

    A state selected at random from the Hilbert space of a many-body system is overwhelmingly likely to exhibit highly non-classical correlations. For these typical states, half of the environment must be measured by an observer to determine the state of a given subsystem. The objectivity of classical reality—the fact that multiple observers can agree on the state of a subsystem after measuring just a small fraction of its environment—implies that the correlations found in nature between macroscopic systems and their environments are exceptional. Building on previous studies of quantum Darwinism showing that highly redundant branching states are produced ubiquitously during pure decoherence, we examine the conditions needed for the creation of branching states and study their demise through many-body interactions. We show that even constrained dynamics can suppress redundancy to the values typical of random states on relaxation timescales, and prove that these results hold exactly in the thermodynamic limit.

  1. Efficient optimization of multi-objective redundancy allocation problems in series-parallel systems

    Directory of Open Access Journals (Sweden)

    Mina Ebrahimi Arjestan

    2017-06-01

    Full Text Available Reliability issues are most important types of optimization problems and they are used in communication, transportation and electrical systems. This paper presents two mathematical models to solve the k-out-of-n redundancy problem where there are two objectives: maximization of reliability and minimization of cost subject to two constraints. Constraints are associated with weight and volume. In addition, strategy of redundancy is intended and ready to go cold and the components of the systems are also identical, because the model is to solve the complex models of the genetic algorithm (GA and simulated annealing (SA. The proposed study uses NSGAII and MOPSO to solve the proposed studies and compare them using TOPSIS method.

  2. How can Steganography BE AN Interpretation of the Redundancy in Pre-Mrna Ribbon?

    Science.gov (United States)

    Regoli, Massimo

    2013-01-01

    In the past years we have developed a new symmetric encryption algorithm based on a new interpretation of the biological phenomenon of the presence of redundant sequences inside pre-mRNA (the introns apparently junk DNA) from a `science of information' point of view. For the first, we have shown the flow of the algorithm by creating a parallel between the various biological aspects of the phenomenon of redundancy and the corresponding agents in our encryption algorithm. Then we set a strict mathematical terminology identifying spaces and mathematical operators for the correct application and interpretation of the algorithm. Finally, last year, we proved that our algorithm has excellent statistics behavior being able to exceed the standard static tests. This year we will try to add a new operator (agent) that is capable of allowing the introduction of a mechanisms like a steganographic sub message (sub ribbon of mRNA) inside the original message (mRNA ribbon).

  3. Uncertain multiobjective redundancy allocation problem of repairable systems based on artificial bee colony algorithm

    Directory of Open Access Journals (Sweden)

    Guo Jiansheng

    2014-12-01

    Full Text Available Based on the uncertainty theory, this paper is devoted to the redundancy allocation problem in repairable parallel-series systems with uncertain factors, where the failure rate, repair rate and other relative coefficients involved are considered as uncertain variables. The availability of the system and the corresponding designing cost are considered as two optimization objectives. A crisp multiobjective optimization formulation is presented on the basis of uncertainty theory to solve this resultant problem. For solving this problem efficiently, a new multiobjective artificial bee colony algorithm is proposed to search the Pareto efficient set, which introduces rank value and crowding distance in the greedy selection strategy, applies fast non-dominated sort procedure in the exploitation search and inserts tournament selection in the onlooker bee phase. It shows that the proposed algorithm outperforms NSGA-II greatly and can solve multiobjective redundancy allocation problem efficiently. Finally, a numerical example is provided to illustrate this approach.

  4. High availability through full redundancy of the CMS detector controls system

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Gerry; et al.

    2012-01-01

    The CMS detector control system (DCS) is responsible for controlling and monitoring the detector status and for the operation of all CMS sub detectors and infrastructure. This is required to ensure safe and efficient data taking so that high quality physics data can be recorded. The current system architecture is composed of more than 100 servers in order to provide the required processing resources. An optimization of the system software and hardware architecture is under development to ensure redundancy of all the controlled subsystems and to reduce any downtime due to hardware or software failures. The new optimized structure is based mainly on powerful and highly reliable blade servers and makes use of a fully redundant approach, guaranteeing high availability and reliability. The analysis of the requirements, the challenges, the improvements and the optimized system architecture as well as its specific hardware and software solutions are presented.

  5. Design structure for in-system redundant array repair in integrated circuits

    Science.gov (United States)

    Bright, Arthur A.; Crumley, Paul G.; Dombrowa, Marc; Douskey, Steven M.; Haring, Rudolf A.; Oakland, Steven F.; Quellette, Michael R.; Strissel, Scott A.

    2008-11-25

    A design structure for repairing an integrated circuit during operation of the integrated circuit. The integrated circuit comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The design structure provides the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The design structure further passes the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

  6. A novel optimal configuration form redundant MEMS inertial sensors based on the orthogonal rotation method.

    Science.gov (United States)

    Cheng, Jianhua; Dong, Jinlu; Landry, Rene; Chen, Daidai

    2014-07-29

    In order to improve the accuracy and reliability of micro-electro mechanical systems (MEMS) navigation systems, an orthogonal rotation method-based nine-gyro redundant MEMS configuration is presented. By analyzing the accuracy and reliability characteristics of an inertial navigation system (INS), criteria for redundant configuration design are introduced. Then the orthogonal rotation configuration is formed through a two-rotation of a set of orthogonal inertial sensors around a space vector. A feasible installation method is given for the real engineering realization of this proposed configuration. The performances of the novel configuration and another six configurations are comprehensively compared and analyzed. Simulation and experimentation are also conducted, and the results show that the orthogonal rotation configuration has the best reliability, accuracy and fault detection and isolation (FDI) performance when the number of gyros is nine.

  7. A Novel Optimal Configuration form Redundant MEMS Inertial Sensors Based on the Orthogonal Rotation Method

    Directory of Open Access Journals (Sweden)

    Jianhua Cheng

    2014-07-01

    Full Text Available In order to improve the accuracy and reliability of micro-electro mechanical systems (MEMS navigation systems, an orthogonal rotation method-based nine-gyro redundant MEMS configuration is presented. By analyzing the accuracy and reliability characteristics of an inertial navigation system (INS, criteria for redundant configuration design are introduced. Then the orthogonal rotation configuration is formed through a two-rotation of a set of orthogonal inertial sensors around a space vector. A feasible installation method is given for the real engineering realization of this proposed configuration. The performances of the novel configuration and another six configurations are comprehensively compared and analyzed. Simulation and experimentation are also conducted, and the results show that the orthogonal rotation configuration has the best reliability, accuracy and fault detection and isolation (FDI performance when the number of gyros is nine.

  8. Obstacle Avoidance Path Planning of Planar Redundant Manipulators Using Workspace Density

    Directory of Open Access Journals (Sweden)

    Hui Dong

    2015-02-01

    Full Text Available This paper presents a new approach to generate the workspace of planar redundant manipulators based on the workspace density of a single link. The workspace density of planar serial redundant manipulators can be computed efficiently by using the concept of the Fourier transform for the group of rigid-body motions of the plane and the convolution theorem. For manipulators using discrete actuation, it is important to study not only the shape of the workspace, but also the density of reachable poses in the workspace. In this paper, we focus on using the workspace density to calculate collision-free paths in complex environments with multiple obstacles in the workspace of the manipulator. This paper presents the algorithm and demonstrates it effectiveness using simulation results.

  9. Cramer-Rao Bound for Blind Channel Estimators in Redundant Block Transmission Systems

    CERN Document Server

    Li, Yen-Huan; Yeh, Ping-Cheng

    2011-01-01

    In this paper, we derive the Cramer-Rao bound (CRB) for blind channel estimation in redundant block transmission systems, a lower bound for the mean squared error of any blind channel estimators. The derived CRB is valid for any full-rank linear redundant precoder, including both zero-padded (ZP) and cyclic-prefixed (CP) precoders. A simple form of CRBs for multiple complex parameters is also derived and presented which facilitates the CRB derivation of the problem of interest. A comparison is made between the derived CRBs and performances of existing subspace-based blind channel estimators for both CP and ZP systems. Numerical results show that there is still some room for performance improvement of blind channel estimators.

  10. On the fail-safe design of tendon-driven manipulators with redundant tendons

    Energy Technology Data Exchange (ETDEWEB)

    Sheu, Jinn Biau; Liu, Tyng; Lee, Jyh Jone [National Taiwan University, Taipei (China)

    2012-06-15

    A tendon-driven manipulator having redundant tendons may possess more flexibility in operation, such as optimizing the performance of tendons, reducing the burden of each tendon, and providing fail-safe features. The purpose of this paper is to investigate the design of tendon-driven manipulators with a fail-safe feature, that is, to synthesize a system that may still remain controllable as any of the tendons have broken down or malfunctioned. Characteristics of tendon-driven manipulators are briefly discussed. Criteria for tendon-driven manipulators with redundant tendons and fail-safe feature are then established. Subsequently, constraints for such system are derived from the structure of tendon-driven manipulator. Associated with the criteria, manipulators can remain controllable when any of the tendons fails to function. Finally, a geometric method for determining the structure is developed. Examples of two-DOF and three-DOF tendondriven manipulators are demonstrated.

  11. Links between N-modular redundancy and the theory of error-correcting codes

    Science.gov (United States)

    Bobin, V.; Whitaker, S.; Maki, G.

    1992-01-01

    N-Modular Redundancy (NMR) is one of the best known fault tolerance techniques. Replication of a module to achieve fault tolerance is in some ways analogous to the use of a repetition code where an information symbol is replicated as parity symbols in a codeword. Linear Error-Correcting Codes (ECC) use linear combinations of information symbols as parity symbols which are used to generate syndromes for error patterns. These observations indicate links between the theory of ECC and the use of hardware redundancy for fault tolerance. In this paper, we explore some of these links and show examples of NMR systems where identification of good and failed elements is accomplished in a manner similar to error correction using linear ECC's.

  12. A New Objective Function for Obstacle Avoidance by Redundant Service Robot Arms

    Directory of Open Access Journals (Sweden)

    Mehmet Ismet Can Dede

    2016-03-01

    Full Text Available The performance of task-space tracking control of kinematically redundant robots regulating self-motion to ensure obstacle avoidance is studied and discussed. As the sub-task objective, the links of the kinematically redundant assistive robot should avoid any collisions with the patient that is being assisted. The shortcomings of the obstacle avoidance algorithms are discussed and a new obstacle avoidance algorithm is proposed. The performance of the proposed algorithm is validated with tests that were carried out using the virtual model of a seven degrees-of-freedom robot arm. The test results indicate that the developed controller for the robot manipulator is successful in both accomplishing the main-task and the sub-task objectives.

  13. Obstacle avoidance for kinematically redundant manipulators using a dual neural network.

    Science.gov (United States)

    Zhang, Yunong; Wang, Jun

    2004-02-01

    One important issue in the motion planning and control of kinematically redundant manipulators is the obstacle avoidance. In this paper, a recurrent neural network is developed and applied for kinematic control of redundant manipulators with obstacle avoidance capability. An improved problem formulation is proposed in the sense that the collision-avoidance requirement is represented by dynamically-updated inequality constraints. In addition, physical constraints such as joint physical limits are also incorporated directly into the formulation. Based on the improved problem formulation, a dual neural network is developed for the online solution to collision-free inverse kinematics problem. The neural network is simulated for motion control of the PA10 robot arm in the presence of point and window-shaped obstacle.

  14. Optimal continuous-path control for manipulators with redundant degrees of freedom

    Directory of Open Access Journals (Sweden)

    Olav Egeland

    1989-04-01

    Full Text Available A control system for macro-mini manipulators is presented. A position transformation from the end-effector reference to joint coordinates is found using kinematic optimization. Decoupling and optimal control is used to coordinate the motion of the macro and micro part. The redundant manipulator will then have the speed of the micro manipulator and the large workspace of the macro manipulator. When optimal control is used, the redundant manipulator may be even faster than the micro manipulator provided that a suitable performance index is used. The performance of the manipulator is optimized over the whole reference, and this will give better results than the purely kinematic instantaneous optimization which is the dominating technique in research literature.

  15. A Dynamic Linear Hashing Method for Redundancy Management in Train Ethernet Consist Network

    Directory of Open Access Journals (Sweden)

    Xiaobo Nie

    2016-01-01

    Full Text Available Massive transportation systems like trains are considered critical systems because they use the communication network to control essential subsystems on board. Critical system requires zero recovery time when a failure occurs in a communication network. The newly published IEC62439-3 defines the high-availability seamless redundancy protocol, which fulfills this requirement and ensures no frame loss in the presence of an error. This paper adopts these for train Ethernet consist network. The challenge is management of the circulating frames, capable of dealing with real-time processing requirements, fast switching times, high throughout, and deterministic behavior. The main contribution of this paper is the in-depth analysis it makes of network parameters imposed by the application of the protocols to train control and monitoring system (TCMS and the redundant circulating frames discarding method based on a dynamic linear hashing, using the fastest method in order to resolve all the issues that are dealt with.

  16. Coded aperture imaging with self-supporting uniformly redundant arrays. [Patent application

    Science.gov (United States)

    Fenimore, E.E.

    1980-09-26

    A self-supporting uniformly redundant array pattern for coded aperture imaging. The invention utilizes holes which are an integer times smaller in each direction than holes in conventional URA patterns. A balance correlation function is generated where holes are represented by 1's, nonholes are represented by -1's, and supporting area is represented by 0's. The self-supporting array can be used for low energy applications where substrates would greatly reduce throughput.

  17. Refinement of light-responsive transcript lists using rice oligonucleotide arrays: evaluation of gene-redundancy.

    Directory of Open Access Journals (Sweden)

    Ki-Hong Jung

    Full Text Available Studies of gene function are often hampered by gene-redundancy, especially in organisms with large genomes such as rice (Oryza sativa. We present an approach for using transcriptomics data to focus functional studies and address redundancy. To this end, we have constructed and validated an inexpensive and publicly available rice oligonucleotide near-whole genome array, called the rice NSF45K array. We generated expression profiles for light- vs. dark-grown rice leaf tissue and validated the biological significance of the data by analyzing sources of variation and confirming expression trends with reverse transcription polymerase chain reaction. We examined trends in the data by evaluating enrichment of gene ontology terms at multiple false discovery rate thresholds. To compare data generated with the NSF45K array with published results, we developed publicly available, web-based tools (www.ricearray.org. The Oligo and EST Anatomy Viewer enables visualization of EST-based expression profiling data for all genes on the array. The Rice Multi-platform Microarray Search Tool facilitates comparison of gene expression profiles across multiple rice microarray platforms. Finally, we incorporated gene expression and biochemical pathway data to reduce the number of candidate gene products putatively participating in the eight steps of the photorespiration pathway from 52 to 10, based on expression levels of putatively functionally redundant genes. We confirmed the efficacy of this method to cope with redundancy by correctly predicting participation in photorespiration of a gene with five paralogs. Applying these methods will accelerate rice functional genomics.

  18. Do Large Carnivores and Mesocarnivores Have Redundant Impacts on Intertidal Prey?

    Science.gov (United States)

    Clinchy, Michael; Zanette, Liana Y.

    2017-01-01

    The presence of large carnivores can affect lower trophic levels by suppressing mesocarnivores and reducing their impacts on prey. The mesopredator release hypothesis therefore predicts prey abundance will be higher where large carnivores are present, but this prediction assumes limited dietary overlap between large and mesocarnivores. Where dietary overlap is high, e.g., among omnivorous carnivore species, or where prey are relatively easily accessible, the potential exists for large and mesocarnivores to have redundant impacts on prey, though this possibility has not been explored. The intertidal community represents a potentially important but poorly studied resource for coastal carnivore populations, and one for which dietary overlap between carnivores may be high. To evaluate usage of the intertidal community by coastal carnivores and the potential for redundancy between large and mesocarnivores, we surveyed (i) intertidal prey abundance (crabs and fish) and (ii) the abundance and activity of large carnivores (predominantly black bears) and mesocarnivores (raccoons and mink) in an area with an intact carnivore community in coastal British Columbia, Canada. Overall carnivore activity was strongly related to intertidal prey availability. Notably, this relationship was not contingent on carnivore species identity, suggestive of redundancy–high intertidal prey availability was associated with either greater large carnivore activity or greater mesocarnivore activity. We then compared intertidal prey abundances in this intact system, in which bears dominate, with those in a nearby system where bears and other large carnivores have been extirpated, and raccoons are the primary intertidal predator. We found significant similarities in intertidal species abundances, providing additional evidence for redundancy between large (bear) and mesocarnivore (raccoon) impacts on intertidal prey. Taken together, our results indicate that intertidal prey shape habitat use and

  19. Redundancy and Aging of Efficient Multidimensional MDS-Parity Protected Distributed Storage Systems

    OpenAIRE

    Arslan, Suayb S.

    2013-01-01

    The effect of redundancy on the aging of an efficient Maximum Distance Separable (MDS) parity--protected distributed storage system that consists of multidimensional arrays of storage units is explored. In light of the experimental evidences and survey data, this paper develops generalized expressions for the reliability of array storage systems based on more realistic time to failure distributions such as Weibull. For instance, a distributed disk array system is considered in which the array...

  20. Commercialization of JPL Virtual Reality calibration and redundant manipulator control technologies

    Science.gov (United States)

    Kim, Won S.; Seraji, Homayoun; Fiorini, Paolo; Brown, Robert; Christensen, Brian; Beale, Chris; Karlen, James; Eismann, Paul

    1994-01-01

    Within NASA's recent thrust for industrial collaboration, JPL (Jet Propulsion Laboratory) has recently established two technology cooperation agreements in the robotics area: one on virtual reality (VR) calibration with Deneb Robotics, Inc., and the other on redundant manipulator control with Robotics Research Corporation (RRC). These technology transfer cooperation tasks will enable both Deneb and RRC to commercialize enhanced versions of their products that will greatly benefit both space and terrestrial telerobotic applications.

  1. Control Systems for Hyper-Redundant Robots Based on Artificial Potential Method

    Directory of Open Access Journals (Sweden)

    Mihaela Florescu

    2015-06-01

    Full Text Available This paper presents the control method of hyper-redundant robots based on the artificial potential approach. The principles of this method are shown and a suggestive example is offered. Then, the artificial potential method is applied to the case of a tentacle robot starting from the dynamic model of the robot. In addition, a series of results that are obtained through simulation is presented.

  2. Minimum redundancy maximum relevance feature selection approach for temporal gene expression data.

    Science.gov (United States)

    Radovic, Milos; Ghalwash, Mohamed; Filipovic, Nenad; Obradovic, Zoran

    2017-01-03

    Feature selection, aiming to identify a subset of features among a possibly large set of features that are relevant for predicting a response, is an important preprocessing step in machine learning. In gene expression studies this is not a trivial task for several reasons, including potential temporal character of data. However, most feature selection approaches developed for microarray data cannot handle multivariate temporal data without previous data flattening, which results in loss of temporal information. We propose a temporal minimum redundancy - maximum relevance (TMRMR) feature selection approach, which is able to handle multivariate temporal data without previous data flattening. In the proposed approach we compute relevance of a gene by averaging F-statistic values calculated across individual time steps, and we compute redundancy between genes by using a dynamical time warping approach. The proposed method is evaluated on three temporal gene expression datasets from human viral challenge studies. Obtained results show that the proposed method outperforms alternatives widely used in gene expression studies. In particular, the proposed method achieved improvement in accuracy in 34 out of 54 experiments, while the other methods outperformed it in no more than 4 experiments. We developed a filter-based feature selection method for temporal gene expression data based on maximum relevance and minimum redundancy criteria. The proposed method incorporates temporal information by combining relevance, which is calculated as an average F-statistic value across different time steps, with redundancy, which is calculated by employing dynamical time warping approach. As evident in our experiments, incorporating the temporal information into the feature selection process leads to selection of more discriminative features.

  3. Simultaneous repetitive motion planning of two redundant robot arms for acceleration-level cooperative manipulation

    Science.gov (United States)

    Zhang, Yunong; Wang, Ying; Guo, Dongsheng; Yu, Xiaotian; Xiao, Lin

    2013-11-01

    This Letter proposes a novel simultaneous repetitive motion planning (SRMP) scheme of two redundant robot arms for cooperative manipulation. To remedy the joint-angle drift phenomenon, two SRMP subschemes are exploited at the joint-acceleration level. The subschemes are then simultaneously reformulated as two quadratic programs (QPs), which are finally unified into a QP problem solving. Theoretical analysis and computer simulation based on two three-link robot arms both substantiate the feasibility and effectiveness of the proposed SRMP scheme.

  4. Fault detection and isolation of PEM fuel cell system based on nonlinear analytical redundancy

    OpenAIRE

    Aitouche, A; Yang, Q; Ould Bouamama, B.

    2011-01-01

    Abstract This paper presents a procedure dealing with the issue of fault detection and isolation (FDI) using nonlinear analytical redundancy (NLAR) technique applied in a proton exchange membrane (PEM) fuel cell system based on its mathematic model. The model is proposed and simplified into a five orders state space representation. The transient phenomena captured in the model include the compressor dynamics, the flow characteristics, mass and energy conservation and manifold fluid...

  5. Functional diversity and redundancy across fish gut, sediment and water bacterial communities.

    Science.gov (United States)

    Escalas, Arthur; Troussellier, Marc; Yuan, Tong; Bouvier, Thierry; Bouvier, Corinne; Mouchet, Maud A; Flores Hernandez, Domingo; Ramos Miranda, Julia; Zhou, Jizhong; Mouillot, David

    2017-08-01

    This article explores the functional diversity and redundancy in a bacterial metacommunity constituted of three habitats (sediment, water column and fish gut) in a coastal lagoon under anthropogenic pressure. Comprehensive functional gene arrays covering a wide range of ecological processes and stress resistance genes to estimate the functional potential of bacterial communities were used. Then, diversity partitioning was used to characterize functional diversity and redundancy within (α), between (β) and across (γ) habitats. It was showed that all local communities exhibit a highly diversified potential for the realization of key ecological processes and resistance to various environmental conditions, supporting the growing evidence that macro-organisms microbiomes harbour a high functional potential and are integral components of functional gene dynamics in aquatic bacterial metacommunities. Several levels of functional redundancy at different scales of the bacterial metacommunity were observed (within local communities, within habitats and at the metacommunity level). The results suggested a high potential for the realization of spatial ecological insurance within this ecosystem, that is, the functional compensation among microorganisms for the realization and maintenance of key ecological processes, within and across habitats. Finally, the role of macro-organisms as dispersal vectors of microbes and their potential influence on marine metacommunity dynamics were discussed. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Reliability modelling of redundant safety systems without automatic diagnostics incorporating common cause failures and process demand.

    Science.gov (United States)

    Alizadeh, Siamak; Sriramula, Srinivas

    2017-11-01

    Redundant safety systems are commonly used in the process industry to respond to hazardous events. In redundant systems composed of identical units, Common Cause Failures (CCFs) can significantly influence system performance with regards to reliability and safety. However, their impact has been overlooked due to the inherent complexity of modelling common cause induced failures. This article develops a reliability model for a redundant safety system using Markov analysis approach. The proposed model incorporates process demands in conjunction with CCF for the first time and evaluates their impacts on the reliability quantification of safety systems without automatic diagnostics. The reliability of the Markov model is quantified by considering the Probability of Failure on Demand (PFD) as a measure for low demand systems. The safety performance of the model is analysed using Hazardous Event Frequency (HEF) to evaluate the frequency of entering a hazardous state that will lead to an accident if the situation is not controlled. The utilisation of Markov model for a simple case study of a pressure protection system is demonstrated and it is shown that the proposed approach gives a sufficiently accurate result for all demand rates, durations, component failure rates and corresponding repair rates for low demand mode of operation. The Markov model proposed in this paper assumes the absence of automatic diagnostics, along with multiple stage repair strategy for CCFs and restoration of the system from hazardous state to the "as good as new" state. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  7. A Redundancy Mechanism Design for Hall-Based Electronic Current Transformers

    Directory of Open Access Journals (Sweden)

    Kun-Long Chen

    2017-03-01

    Full Text Available Traditional current transformers (CTs suffer from DC and AC saturation and remanent magnetization in many industrial applications. Moreover, the drawbacks of traditional CTs, such as closed iron cores, bulky volume, and heavy weight, further limit the development of an intelligent power protection system. In order to compensate for these drawbacks, we proposed a novel current measurement method by using Hall sensors, which is called the Hall-effect current transformer (HCT. The existing commercial Hall sensors are electronic components, so the reliability of the HCT is normally worse than that of the traditional CT. Therefore, our study proposes a redundancy mechanism for the HCT to strengthen its reliability. With multiple sensor modules, the method has the ability to improve the accuracy of the HCT as well. Additionally, the proposed redundancy mechanism monitoring system provides a condition-based maintenance for the HCT. We verify our method with both simulations and an experimental test. The results demonstrate that the proposed HCT with a redundancy mechanism can almost achieve Class 0.2 for measuring CTs according to IEC Standard 60044-8.

  8. An inverse kinematics algorithm for a highly redundant variable-geometry-truss manipulator

    Science.gov (United States)

    Naccarato, Frank; Hughes, Peter

    1989-01-01

    A new class of robotic arm consists of a periodic sequence of truss substructures, each of which has several variable-length members. Such variable-geometry-truss manipulator (VGTMs) are inherently highly redundant and promise a significant increase in dexterity over conventional anthropomorphic manipulators. This dexterity may be exploited for both obstacle avoidance and controlled deployment in complex workspaces. The inverse kinematics problem for such unorthodox manipulators, however, becomes complex because of the large number of degrees of freedom, and conventional solutions to the inverse kinematics problem become inefficient because of the high degree of redundancy. A solution is presented to this problem based on a spline-like reference curve for the manipulator's shape. Such an approach has a number of advantages: (1) direct, intuitive manipulation of shape; (2) reduced calculation time; and (3) direct control over the effective degree of redundancy of the manipulator. Furthermore, although the algorithm was developed primarily for variable-geometry-truss manipulators, it is general enough for application to a number of manipulator designs.

  9. Redundant and physical black hole parameters: Is there an independent physical dilaton charge?

    Science.gov (United States)

    Hajian, K.; Sheikh-Jabbari, M. M.

    2017-05-01

    Black holes as solutions to gravity theories, are generically identified by a set of parameters. Some of these parameters are associated with black hole physical conserved charges, like ADM charges. There can also be some ;redundant parameters.; We propose necessary conditions for a parameter to be physical. The conditions are essentially integrability and non-triviality of the charge variations arising from ;parametric variations,; variation of the solution with respect to the chosen parameters. In addition, we prove that variation of the redundant parameters which do not meet our criteria do not appear in the first law of thermodynamics. As an interesting application, we show that dilaton moduli are redundant parameters for black hole solutions to Einstein-Maxwell-(Axion)-Dilaton theories, because variations in dilaton moduli would render entropy, mass, electric charges or angular momenta non-integrable. Our results are in contrast with modification of the first law due to scalar charges suggested in Gibbons-Kallosh-Kol paper [1] and its follow-ups. We also briefly discuss implications of our results for the attractor behavior of extremal black holes.

  10. Redundant and physical black hole parameters: Is there an independent physical dilaton charge?

    Directory of Open Access Journals (Sweden)

    K. Hajian

    2017-05-01

    Full Text Available Black holes as solutions to gravity theories, are generically identified by a set of parameters. Some of these parameters are associated with black hole physical conserved charges, like ADM charges. There can also be some “redundant parameters.” We propose necessary conditions for a parameter to be physical. The conditions are essentially integrability and non-triviality of the charge variations arising from “parametric variations,” variation of the solution with respect to the chosen parameters. In addition, we prove that variation of the redundant parameters which do not meet our criteria do not appear in the first law of thermodynamics. As an interesting application, we show that dilaton moduli are redundant parameters for black hole solutions to Einstein–Maxwell–(Axion–Dilaton theories, because variations in dilaton moduli would render entropy, mass, electric charges or angular momenta non-integrable. Our results are in contrast with modification of the first law due to scalar charges suggested in Gibbons–Kallosh–Kol paper [1] and its follow-ups. We also briefly discuss implications of our results for the attractor behavior of extremal black holes.

  11. Redundant and physical black hole parameters: Is there an independent physical dilaton charge?

    Energy Technology Data Exchange (ETDEWEB)

    Hajian, K., E-mail: kamalhajian@ipm.ir; Sheikh-Jabbari, M.M., E-mail: jabbari@theory.ipm.ac.ir

    2017-05-10

    Black holes as solutions to gravity theories, are generically identified by a set of parameters. Some of these parameters are associated with black hole physical conserved charges, like ADM charges. There can also be some “redundant parameters.” We propose necessary conditions for a parameter to be physical. The conditions are essentially integrability and non-triviality of the charge variations arising from “parametric variations,” variation of the solution with respect to the chosen parameters. In addition, we prove that variation of the redundant parameters which do not meet our criteria do not appear in the first law of thermodynamics. As an interesting application, we show that dilaton moduli are redundant parameters for black hole solutions to Einstein–Maxwell–(Axion)–Dilaton theories, because variations in dilaton moduli would render entropy, mass, electric charges or angular momenta non-integrable. Our results are in contrast with modification of the first law due to scalar charges suggested in Gibbons–Kallosh–Kol paper and its follow-ups. We also briefly discuss implications of our results for the attractor behavior of extremal black holes.

  12. Experimental removal and recovery of subtidal grazers highlights the importance of functional redundancy and temporal context.

    Directory of Open Access Journals (Sweden)

    Robin Elahi

    Full Text Available The extent to which different grazers are functionally redundant has strong implications for the maintenance of community structure and function. Grazing by red urchins (Strongylocentrotus franciscanus on temperate rocky reefs can initiate a switch from invertebrate or macroalgal dominance to an algal crust state, but can also cause increases in the density of molluscan mesograzers. In this study, we tested the hypothesis that red urchins and lined chitons (Tonicella spp. are redundant in the maintenance of available space, defined as encrusting algae and bare rock. In a factorial field experiment replicated at three sites, we reduced the densities of urchins and chitons on subtidal rock walls for nine months. The effects of grazers were interpreted in the context of natural temporal variation by monitoring the benthic community one year before, during, and after grazer removal. The removal of each grazer in isolation had no effect on the epilithic community, but the removal of both grazers caused an increase in sessile invertebrates. The increase was due primarily to clonal ascidians, which displayed a large (∼75% relative increase in response to the removal of both grazers. However, the observed non-additive responses to grazer removal were temporary and smaller than seasonal fluctuations. Our data demonstrate that urchins and chitons can be redundant in the maintenance of available space, and highlight the value of drawing conclusions from experimental manipulations within an extended temporal context.

  13. Computational and experimental analysis of redundancy in the central metabolism of Geobacter sulfurreducens.

    Directory of Open Access Journals (Sweden)

    Daniel Segura

    2008-02-01

    Full Text Available Previous model-based analysis of the metabolic network of Geobacter sulfurreducens suggested the existence of several redundant pathways. Here, we identified eight sets of redundant pathways that included redundancy for the assimilation of acetate, and for the conversion of pyruvate into acetyl-CoA. These equivalent pathways and two other sub-optimal pathways were studied using 5 single-gene deletion mutants in those pathways for the evaluation of the predictive capacity of the model. The growth phenotypes of these mutants were studied under 12 different conditions of electron donor and acceptor availability. The comparison of the model predictions with the resulting experimental phenotypes indicated that pyruvate ferredoxin oxidoreductase is the only activity able to convert pyruvate into acetyl-CoA. However, the results and the modeling showed that the two acetate activation pathways present are not only active, but needed due to the additional role of the acetyl-CoA transferase in the TCA cycle, probably reflecting the adaptation of these bacteria to acetate utilization. In other cases, the data reconciliation suggested additional capacity constraints that were confirmed with biochemical assays. The results demonstrate the need to experimentally verify the activity of key enzymes when developing in silico models of microbial physiology based on sequence-based reconstruction of metabolic networks.

  14. Fission Yeast Exo1 and Rqh1-Dna2 Redundantly Contribute to Resection of Uncapped Telomeres.

    Directory of Open Access Journals (Sweden)

    Tomoko Nanbu

    Full Text Available The uncapping of telomeres induces a DNA damage response. In Schizosaccharomyces pombe, deletion of pot1+ causes telomere uncapping and rapid telomere resection, resulting in chromosome fusion. Using the nmt-pot1-aid strain, we previously reported that Pot1 shut-off causes telomere loss and chromosome fusion in S. pombe. However, the factors responsible for the resection of uncapped telomeres remain unknown. In this study, we investigated these factors and found that concomitant deletion of rqh1+ and exo1+ alleviated the loss of telomeres following Pot1 shut-off, suggesting that Rqh1 and Exo1 are redundantly involved in the resection of uncapped telomeres. We also investigated the role of Rqh1 helicase activity and found it to be essential for the resection of uncapped telomeres. Moreover, we found that Dna2 and Exo1 function redundantly in the resection of uncapped telomeres. Taken together, these results suggest that Exo1 and Rqh1-Dna2 redundantly contribute to the resection of uncapped telomeres. Therefore, our results demonstrate that nmt-pot1-aid is an important model strain to study the role of helicases and nucleases in the resection of uncapped telomeres and to improve our understanding of DNA double-strand break repair.

  15. Detumbling control for kinematically redundant space manipulator post-grasping a rotational satellite

    Science.gov (United States)

    Wang, Mingming; Luo, Jianjun; Yuan, Jianping; Walter, Ulrich

    2017-12-01

    The objective of this paper is to establish a detumbling strategy and a coordination control scheme for a kinematically redundant space manipulator post-grasping a rotational satellite. First, the dynamics of the kinematically redundant space robot after grasping the target is presented, which lays the foundation for the coordination controller design. Subsequently, optimal detumbling and motion planning strategy for the post-capture phase is proposed based on the quartic Bézier curves and adaptive differential evolution (DE) algorithm subject to the specific constraints. Both detumbling time and control torques are taken into account for the generation of the optimal detumbling strategy. Furthermore, a coordination control scheme is presented to track the designed reference path while regulating the attitude of the chaser to a desired value, which successfully dumps the initial angular velocity of the rotational satellite and controls the base attitude synchronously. Simulation results are presented for detumbling a target with rotational motion using a 7 degree-of-freedom (DOF) redundant space manipulator, which demonstrates the effectiveness of the proposed method.

  16. Synchronization and redundancy: implications for robustness of neural learning and decision making.

    Science.gov (United States)

    Bouvrie, Jake; Slotine, Jean-Jacques

    2011-11-01

    Learning and decision making in the brain are key processes critical to survival, and yet are processes implemented by nonideal biological building blocks that can impose significant error. We explore quantitatively how the brain might cope with this inherent source of error by taking advantage of two ubiquitous mechanisms, redundancy and synchronization. In particular we consider a neural process whose goal is to learn a decision function by implementing a nonlinear gradient dynamics. The dynamics, however, are assumed to be corrupted by perturbations modeling the error, which might be incurred due to limitations of the biology, intrinsic neuronal noise, and imperfect measurements. We show that error, and the associated uncertainty surrounding a learned solution, can be controlled in large part by trading off synchronization strength among multiple redundant neural systems against the noise amplitude. The impact of the coupling between such redundant systems is quantified by the spectrum of the network Laplacian, and we discuss the role of network topology in synchronization and in reducing the effect of noise. We discuss range of situations in which the mechanisms we model arise in brain science and draw attention to experimental evidence suggesting that cortical circuits capable of implementing the computations of interest here can be found on several scales. Finally, simulations comparing theoretical bounds to the relevant empirical quantities show that the theoretical estimates we derive can be tight.

  17. Biodiversity and multifunctionality in a microbial community: a novel theoretical approach to quantify functional redundancy.

    Science.gov (United States)

    Miki, Takeshi; Yokokawa, Taichi; Matsui, Kazuaki

    2014-02-07

    Ecosystems have a limited buffering capacity of multiple ecosystem functions against biodiversity loss (i.e. low multifunctional redundancy). We developed a novel theoretical approach to evaluate multifunctional redundancy in a microbial community using the microbial genome database (MBGD) for comparative analysis. In order to fully implement functional information, we defined orthologue richness in a community, each of which is a functionally conservative evolutionary unit in genomes, as an index of community multifunctionality (MF). We constructed a graph of expected orthologue richness in a community (MF) as a function of species richness (SR), fit the power function to SR (i.e. MF = cSR(a)), and interpreted the higher exponent a as the lower multifunctional redundancy. Through a microcosm experiment, we confirmed that MF defined by orthologue richness could predict the actual multiple functions. We simulated random and non-random community assemblages using full genomic data of 478 prokaryotic species in the MBGD, and determined that the exponent in microbial communities ranged from 0.55 to 0.75. This exponent range provided a quantitative estimate that a 6.6-8.9% loss limit in SR occurred in a microbial community for an MF reduction no greater than 5%, suggesting a non-negligible initial loss effect of microbial diversity on MF.

  18. Performance and delay analysis of hybrid ARQ with incremental redundancy over double rayleigh fading channels

    KAUST Repository

    Chelli, Ali

    2014-11-01

    In this paper, we study the performance of hybrid automatic repeat request (HARQ) with incremental redundancy over double Rayleigh channels, a common model for the fading amplitude of vehicle-to-vehicle communication systems. We investigate the performance of HARQ from an information theoretic perspective. Analytical expressions are derived for the \\\\epsilon-outage capacity, the average number of transmissions, and the average transmission rate of HARQ with incremental redundancy assuming a maximum number of HARQ rounds. Moreover, we evaluate the delay experienced by Poisson arriving packets for HARQ with incremental redundancy. We provide analytical expressions for the expected waiting time, the packet\\'s sojourn time in the queue, the average consumed power, and the energy efficiency. In our study, the communication rate per HARQ round is adjusted to the average signal-to-noise ratio (SNR) such that a target outage probability is not exceeded. This setting conforms with communication systems in which a quality of service is expected regardless of the channel conditions. Our analysis underscores the importance of HARQ in improving the spectral efficiency and reliability of communication systems. We demonstrate as well that the explored HARQ scheme achieves full diversity. Additionally, we investigate the tradeoff between energy efficiency and spectral efficiency.

  19. On Control of Reaching Movements for Musculo-Skeletal Redundant Arm Model

    Directory of Open Access Journals (Sweden)

    Kenji Tahara

    2009-01-01

    Full Text Available This paper focuses on a dynamic sensory-motor control mechanism of reaching movements for a musculo-skeletal redundant arm model. The formulation of a musculo-skeletal redundant arm system, which takes into account non-linear muscle properties obtained by some physiological understandings, is introduced and numerical simulations are perfomed. The non-linear properties of muscle dynamics make it possible to modulate the viscosity of the joints, and the end point of the arm converges to the desired point with a simple task-space feedback when adequate internal forces are chosen, regardless of the redundancy of the joint. Numerical simulations were performed and the effectiveness of our control scheme is discussed through these results. The results suggest that the reaching movements can be achieved using only a simple task-space feedback scheme together with the internal force effect that comes from non-linear properties of skeletal muscles without any complex mathematical computation such as an inverse dynamics or optimal trajectory derivation. In addition, the dynamic damping ellipsoid for evaluating how the internal forces can be determined is introduced. The task-space feedback is extended to the ‘virtual spring-damper hypothesis’ based on the research by Arimoto et al. (2006 to reduce the muscle output forces and heterogeneity of convergence depending on the initial state and desired position. The research suggests a new direction for studies of brain-motor control mechanism of human movements.

  20. Learning to be lazy: exploiting redundancy in a novel task to minimize movement-related effort.

    Science.gov (United States)

    Ranganathan, Rajiv; Adewuyi, Adenike; Mussa-Ivaldi, Ferdinando A

    2013-02-13

    A key issue in motor control is to understand how the motor system chooses a solution from the multiple solutions that exist to achieve any particular task goal. One hypothesis is that redundancy may be resolved by minimizing movement-related costs. However, testing this prediction in motor learning has been problematic in simple laboratory tasks, like reaching, because the motor system already has extensive prior knowledge about redundancy in these tasks. Here, we used a novel task where healthy human participants performed finger movements to guide a computer cursor to different targets on the screen. Through training, all participants learned to perform successful goal-directed movements. Our findings showed that subjects did not develop a single inverse map from target to hand posture. Instead, they learned to use distinct hand postures to get to a single target, using a strategy in which the final hand posture at the target depended on the starting hand posture. Furthermore, postures chosen also depended upon the information content of visual feedback, with precise visual feedback resulting in postures that minimized movement-related costs. These results reinforce the idea that redundancy is exploited to minimize movement-related costs and that feedback plays a critical role in modulating this ability to effectively take advantage of the abundance of degrees of freedom.

  1. Sustainable Modular Adaptive Redundancy Technique Emphasizing Partial Reconfiguration for Reduced Power Consumption

    Directory of Open Access Journals (Sweden)

    R. Al-Haddad

    2011-01-01

    Full Text Available As reconfigurable devices' capacities and the complexity of applications that use them increase, the need for self-reliance of deployed systems becomes increasingly prominent. Organic computing paradigms have been proposed for fault-tolerant systems because they promote behaviors that allow complex digital systems to adapt and survive in demanding environments. In this paper, we develop a sustainable modular adaptive redundancy technique (SMART composed of a two-layered organic system. The hardware layer is implemented on a Xilinx Virtex-4 Field Programmable Gate Array (FPGA to provide self-repair using a novel approach called reconfigurable adaptive redundancy system (RARS. The software layer supervises the organic activities on the FPGA and extends the self-healing capabilities through application-independent, intrinsic, and evolutionary repair techniques that leverage the benefits of dynamic partial reconfiguration (PR. SMART was evaluated using a Sobel edge-detection application and was shown to tolerate stressful sequences of injected transient and permanent faults while reducing dynamic power consumption by 30% compared to conventional triple modular redundancy (TMR techniques, with nominal impact on the fault-tolerance capabilities. Moreover, PR is employed to keep the system on line while under repair and also to reduce repair time. Experiments have shown a 27.48% decrease in repair time when PR is employed compared to the full bitstream configuration case.

  2. Compound faults detection of rotating machinery using improved adaptive redundant lifting multiwavelet

    Science.gov (United States)

    Chen, Jinglong; Zi, Yanyang; He, Zhengjia; Yuan, Jing

    2013-07-01

    Due to the character of diversity and complexity, the compound faults detection of rotating machinery under non-stationary operation turns into a challenging task. Multiwavelet with two or more base functions and many excellent properties provides a possibility to detect and extract all the features of compound faults at one time. However, the fixed basis functions independent of the vibration signal may decrease the accuracy of fault detection. Moreover, the decomposition result of discrete multiwavelet transform does not possess time invariance, which is harmful to extract the feature of periodical impulses. To overcome these deficiencies, based on the Hermite splines interpolation, taking the minimum envelope spectrum entropy as the optimization objective, adaptive redundant lifting multiwavelet is developed. Additionally, in order to eliminate error propagation of decomposition results, adaptive redundant lifting multiwavelet is improved by adding the normalization factors. As an effective method, Hilbert transform demodulation analysis is used to extract the fault feature from the high frequency modulation signal. The proposed method incorporating improved adaptive redundant lifting multiwavelet (IARLM) with Hilbert transform demodulation analysis is applied to compound faults detection for the simulation experiment, rolling element bearing test bench and traveling unit of electric locomotive. Compared with some other fault detection methods, the results show the superior effectiveness and reliability on the compound faults detection.

  3. Multiple Description Coding with Redundant Expansions and Application to Image Communications

    Directory of Open Access Journals (Sweden)

    Radulovic Ivana

    2007-01-01

    Full Text Available Multiple description coding offers an elegant and competitive solution for data transmission over lossy packet-based networks, with a graceful degradation in quality as losses increase. In the same time, coding techniques based on redundant transforms give a very promising alternative for the generation of multiple descriptions, mainly due to redundancy inherently given by a transform, which offers intrinsic resiliency in case of loss. In this paper, we show how partitioning of a generic redundant dictionary can be used to obtain an arbitrary number of multiple complementary, yet correlated, descriptions. The most significant terms in the signal representation are drawn from the partitions that better approximate the signal, and split to different descriptions, while the less important ones are alternatively distributed between the descriptions. As compared to state-of-the-art solutions, such a strategy allows for a better central distortion since atoms in different descriptions are not identical; in the same time, it does not penalize the side distortions significantly since atoms from the same partition are likely to be highly correlated. The proposed scheme is applied to the multiple description coding of digital images, and simulation results show increased performances compared to state-of-the-art schemes, both in terms of distortions and robustness to loss rate variations.

  4. Multiple Description Coding with Redundant Expansions and Application to Image Communications

    Directory of Open Access Journals (Sweden)

    Ivana Radulovic

    2007-02-01

    Full Text Available Multiple description coding offers an elegant and competitive solution for data transmission over lossy packet-based networks, with a graceful degradation in quality as losses increase. In the same time, coding techniques based on redundant transforms give a very promising alternative for the generation of multiple descriptions, mainly due to redundancy inherently given by a transform, which offers intrinsic resiliency in case of loss. In this paper, we show how partitioning of a generic redundant dictionary can be used to obtain an arbitrary number of multiple complementary, yet correlated, descriptions. The most significant terms in the signal representation are drawn from the partitions that better approximate the signal, and split to different descriptions, while the less important ones are alternatively distributed between the descriptions. As compared to state-of-the-art solutions, such a strategy allows for a better central distortion since atoms in different descriptions are not identical; in the same time, it does not penalize the side distortions significantly since atoms from the same partition are likely to be highly correlated. The proposed scheme is applied to the multiple description coding of digital images, and simulation results show increased performances compared to state-of-the-art schemes, both in terms of distortions and robustness to loss rate variations.

  5. G2-type SRMPC scheme for synchronous manipulation of two redundant robot arms.

    Science.gov (United States)

    Jin, Long; Zhang, Yunong

    2015-02-01

    In this paper, to remedy the joint-angle drift phenomenon for manipulation of two redundant robot arms, a novel scheme for simultaneous repetitive motion planning and control (SRMPC) at the joint-acceleration level is proposed, which consists of two subschemes. To do so, the performance index of each SRMPC subscheme is derived and designed by employing the gradient dynamics twice, of which a convergence theorem and its proof are presented. In addition, for improving the accuracy of the motion planning and control, position error, and velocity, error feedbacks are incorporated into the forward kinematics equation and analyzed via Zhang neural-dynamics method. Then the two subschemes are simultaneously reformulated as two quadratic programs (QPs), which are finally unified into one QP problem. Furthermore, a piecewise-linear projection equation-based neural network (PLPENN) is used to solve the unified QP problem, which can handle the strictly convex QP problem in an inverse-free manner. More importantly, via such a unified QP formulation and the corresponding PLPENN solver, the synchronism of two redundant robot arms is guaranteed. Finally, two given tasks are fulfilled by 2 three-link and 2 five-link planar robot arms, respectively. Computer-simulation results validate the efficacy and accuracy of the SRMPC scheme and the corresponding PLPENN solver for synchronous manipulation of two redundant robot arms.

  6. Redundant control of migration and adhesion by ERM proteins in vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Baeyens, Nicolas; Latrache, Iman; Yerna, Xavier [Laboratory of Cell Physiology, IoNS, Université Catholique de Louvain (Belgium); Noppe, Gauthier; Horman, Sandrine [Pôle de Recherche Cardiovasculaire, IREC, Université Catholique de Louvain (Belgium); Morel, Nicole, E-mail: nicole.morel@uclouvain.be [Laboratory of Cell Physiology, IoNS, Université Catholique de Louvain (Belgium)

    2013-11-22

    Highlights: •The three ERM proteins are expressed in vascular smooth muscle cell. •ERM depletion inhibited PDGF-evoked migration redundantly. •ERM depletion increased cell adhesion redundantly. •ERM depletion did not affect PDGF-evoked Ca signal, Rac1 activation, proliferation. •ERM proteins control PDGF-induced migration by regulating adhesion. -- Abstract: Ezrin, radixin, and moesin possess a very similar structure with a C-terminal actin-binding domain and a N-terminal FERM interacting domain. They are known to be involved in cytoskeleton organization in several cell types but their function in vascular smooth muscle cells (VSMC) is still unknown. The aim of this study was to investigate the role of ERM proteins in cell migration induced by PDGF, a growth factor involved in pathophysiological processes like angiogenesis or atherosclerosis. We used primary cultured VSMC obtained from rat aorta, which express the three ERM proteins. Simultaneous depletion of the three ERM proteins with specific siRNAs abolished the effects of PDGF on cell architecture and migration and markedly increased cell adhesion and focal adhesion size, while these parameters were only slightly affected by depletion of ezrin, radixin or moesin alone. Rac1 activation, cell proliferation, and Ca{sup 2+} signal in response to PDGF were unaffected by ERM depletion. These results indicate that ERM proteins exert a redundant control on PDGF-induced VSMC migration by regulating focal adhesion turn-over and cell adhesion to substrate.

  7. Dual redundant sensor FDI techniques applied to the NASA F8C DFBW aircraft. [Failure Detection and Identification

    Science.gov (United States)

    Desai, M. N.; Deckert, J. C.; Deyst, J. J.; Willsky, A. S.; Chow, E. Y.

    1976-01-01

    An onboard failure detection and identification (FDI) technique for dual redundant sensors on the NASA F8C digital fly-by-wire (DFBW) aircraft is presented. The failure of one of a pair of sensors of the same type is detected by a direct redundancy trigger which observes the difference between the outputs of these two sensors. Identification of the failed sensor is accomplished utilizing the analytic redundancy that exists as kinematic and functional relationships among the variables being measured by dissimilar instruments. In addition, identification of generic failures, common to both instruments of a given type, is accomplished by using a time trigger to periodically initiate analytic redundancy failure identification tests for individual sensors. The basic form of these tests is the comparison of the measurement of a variable using the suspect instrument with another measurement of the same variable obtained using other instrument types.

  8. Target gene analysis by microarrays and chromatin immunoprecipitation identifies HEY proteins as highly redundant bHLH repressors.

    Science.gov (United States)

    Heisig, Julia; Weber, David; Englberger, Eva; Winkler, Anja; Kneitz, Susanne; Sung, Wing-Kin; Wolf, Elmar; Eilers, Martin; Wei, Chia-Lin; Gessler, Manfred

    2012-01-01

    HEY bHLH transcription factors have been shown to regulate multiple key steps in cardiovascular development. They can be induced by activated NOTCH receptors, but other upstream stimuli mediated by TGFß and BMP receptors may elicit a similar response. While the basic and helix-loop-helix domains exhibit strong similarity, large parts of the proteins are still unique and may serve divergent functions. The striking overlap of cardiac defects in HEY2 and combined HEY1/HEYL knockout mice suggested that all three HEY genes fulfill overlapping function in target cells. We therefore sought to identify target genes for HEY proteins by microarray expression and ChIPseq analyses in HEK293 cells, cardiomyocytes, and murine hearts. HEY proteins were found to modulate expression of their target gene to a rather limited extent, but with striking functional interchangeability between HEY factors. Chromatin immunoprecipitation revealed a much greater number of potential binding sites that again largely overlap between HEY factors. Binding sites are clustered in the proximal promoter region especially of transcriptional regulators or developmental control genes. Multiple lines of evidence suggest that HEY proteins primarily act as direct transcriptional repressors, while gene activation seems to be due to secondary or indirect effects. Mutagenesis of putative DNA binding residues supports the notion of direct DNA binding. While class B E-box sequences (CACGYG) clearly represent preferred target sequences, there must be additional and more loosely defined modes of DNA binding since many of the target promoters that are efficiently bound by HEY proteins do not contain an E-box motif. These data clearly establish the three HEY bHLH factors as highly redundant transcriptional repressors in vitro and in vivo, which explains the combinatorial action observed in different tissues with overlapping expression.

  9. Dual redundant sequencing strategy: Full-length gene characterisation of 1056 novel and confirmatory HLA alleles.

    Science.gov (United States)

    Albrecht, V; Zweiniger, C; Surendranath, V; Lang, K; Schöfl, G; Dahl, A; Winkler, S; Lange, V; Böhme, I; Schmidt, A H

    2017-08-01

    The high-throughput department of DKMS Life Science Lab encounters novel human leukocyte antigen (HLA) alleles on a daily basis. To characterise these alleles, we have developed a system to sequence the whole gene from 5'- to 3'-UTR for the HLA loci A, B, C, DQB1 and DPB1 for submission to the European Molecular Biology Laboratory - European Nucleotide Archive (EMBL-ENA) and the IPD-IMGT/HLA Database. Our workflow is based on a dual redundant sequencing strategy. Using shotgun sequencing on an Illumina MiSeq instrument and single molecule real-time (SMRT) sequencing on a PacBio RS II instrument, we are able to achieve highly accurate HLA full-length consensus sequences. Remaining conflicts are resolved using the R package DR2S (Dual Redundant Reference Sequencing). Given the relatively high throughput of this strategy, we have developed the semi-automated web service TypeLoader, to aid in the submission of sequences to the EMBL-ENA and the IPD-IMGT/HLA Database. In the IPD-IMGT/HLA Database release 3.24.0 (April 2016; prior to the submission of the sequences described here), only 5.2% of all known HLA alleles have been fully characterised together with intronic and UTR sequences. So far, we have applied our strategy to characterise and submit 1056 HLA alleles, thereby more than doubling the number of fully characterised alleles. Given the increasing application of next generation sequencing (NGS) for full gene characterisation in clinical practice, extending the HLA database concomitantly is highly desirable. Therefore, we propose this dual redundant sequencing strategy as a workflow for submission of novel full-length alleles and characterisation of sequences that are as yet incomplete. This would help to mitigate the predominance of partially known alleles in the database. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Learning with slight forgetting optimizes sensorimotor transformation in redundant motor systems.

    Directory of Open Access Journals (Sweden)

    Masaya Hirashima

    Full Text Available Recent theoretical studies have proposed that the redundant motor system in humans achieves well-organized stereotypical movements by minimizing motor effort cost and motor error. However, it is unclear how this optimization process is implemented in the brain, presumably because conventional schemes have assumed a priori that the brain somehow constructs the optimal motor command, and largely ignored the underlying trial-by-trial learning process. In contrast, recent studies focusing on the trial-by-trial modification of motor commands based on error information suggested that forgetting (i.e., memory decay, which is usually considered as an inconvenient factor in motor learning, plays an important role in minimizing the motor effort cost. Here, we examine whether trial-by-trial error-feedback learning with slight forgetting could minimize the motor effort and error in a highly redundant neural network for sensorimotor transformation and whether it could predict the stereotypical activation patterns observed in primary motor cortex (M1 neurons. First, using a simple linear neural network model, we theoretically demonstrated that: 1 this algorithm consistently leads the neural network to converge at a unique optimal state; 2 the biomechanical properties of the musculoskeletal system necessarily determine the distribution of the preferred directions (PD; the direction in which the neuron is maximally active of M1 neurons; and 3 the bias of the PDs is steadily formed during the minimization of the motor effort. Furthermore, using a non-linear network model with realistic musculoskeletal data, we demonstrated numerically that this algorithm could consistently reproduce the PD distribution observed in various motor tasks, including two-dimensional isometric torque production, two-dimensional reaching, and even three-dimensional reaching tasks. These results may suggest that slight forgetting in the sensorimotor transformation network is responsible

  11. Identification of redundant and synergetic circuits in triplets of electrophysiological data

    Science.gov (United States)

    Erramuzpe, Asier; Ortega, Guillermo J.; Pastor, Jesus; de Sola, Rafael G.; Marinazzo, Daniele; Stramaglia, Sebastiano; Cortes, Jesus M.

    2015-12-01

    Objective. Neural systems are comprised of interacting units, and relevant information regarding their function or malfunction can be inferred by analyzing the statistical dependencies between the activity of each unit. While correlations and mutual information are commonly used to characterize these dependencies, our objective here is to extend interactions to triplets of variables to better detect and characterize dynamic information transfer. Approach. Our approach relies on the measure of interaction information (II). The sign of II provides information as to the extent to which the interaction of variables in triplets is redundant (R) or synergetic (S). Three variables are said to be redundant when a third variable, say Z, added to a pair of variables (X, Y), diminishes the information shared between X and Y. Similarly, the interaction in the triplet is said to be synergetic when conditioning on Z enhances the information shared between X and Y with respect to the unconditioned state. Here, based on this approach, we calculated the R and S status for triplets of electrophysiological data recorded from drug-resistant patients with mesial temporal lobe epilepsy in order to study the spatial organization and dynamics of R and S close to the epileptogenic zone (the area responsible for seizure propagation). Main results. In terms of spatial organization, our results show that R matched the epileptogenic zone while S was distributed more in the surrounding area. In relation to dynamics, R made the largest contribution to high frequency bands (14-100 Hz), while S was expressed more strongly at lower frequencies (1-7 Hz). Thus, applying II to such clinical data reveals new aspects of epileptogenic structure in terms of the nature (redundancy versus synergy) and dynamics (fast versus slow rhythms) of the interactions. Significance. We expect this methodology, robust and simple, can reveal new aspects beyond pair-interactions in networks of interacting units in other

  12. Lack of developmental redundancy between Unc45 proteins in zebrafish muscle development.

    Directory of Open Access Journals (Sweden)

    Sophie A Comyn

    Full Text Available Since the majority of protein-coding genes in vertebrates have intra-genomic homologues, it has been difficult to eliminate the potential of functional redundancy from analyses of mutant phenotypes, whether produced by genetic lesion or transient knockdown. Further complicating these analyses, not all gene products have activities that can be assayed in vitro, where the efficiency of the various family members can be compared against constant substrates. Two vertebrate UNC-45 homologues, unc45a and unc45b, affect distinct stages of muscle differentiation when knocked down in cell culture and are functionally redundant in vitro. UNC-45 proteins are members of the UCS (UNC-45/CRO1/She4p protein family that has been shown to regulate myosin-dependent functions from fungi to vertebrates through direct interaction with the myosin motor domain. To test whether the same functional relationship exists between these unc45 paralogs in vivo, we examined the developmental phenotypes of doubly homozygous unc45b(-/-; unc45a(-/- mutant zebrafish embryos. We focused specifically on the combined effects on morphology and gene expression resulting from the zygotic lack of both paralogs. We found that unc45b(-/- and unc45b(-/-; unc45a(-/- embryos were phenotypically indistinguishable with both mutants displaying identical cardiac, skeletal muscle, and jaw defects. We also found no evidence to support a role for zygotic Unc45a function in myoblast differentiation. In contrast to previous in vitro work, this rules out a model of functional redundancy between Unc45a and Unc45b in vivo. Instead, our phylogenetic and phenotypic analyses provide evidence for the role of functional divergence in the evolution of the UCS protein family.

  13. Strategies for redundancy resolution of dual-arm systems with passive elements for tank waste removal

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, R. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Mechanical Engineering; Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-03-01

    The work described in this paper focuses on the coordination and control of two manipulators coupled by passive elements operating in a confined space. An example of one such system is the hardware used for the environmental response treatability study funded by the Department of Energy at Oak Ridge National Laboratory (ORNL). The motivation for this project is to establish the methodology necessary to extract large volumes of hazardous waste from underground storage facilities. The hardware used at ORNL consists of two long-reach manipulators. The first robot, the Modified Light Duty Utility Arm (MLDUA), is an 8-degree-of-freedom long-reach manipulator. The second arm, the Hose Management Arm (HMA), has two active degrees-of-freedom and provides hardware to break up and extract materials from the tank. Current strategies call for the MLDUA to grasp a combined sluicing end-effector attached, by a long flexible hose, to the HMA. The MLDUA will then move the combined system through the waste, extracting material. This paper describes many of the issues related to redundancy resolution and the coordinated control of these two robots. First, the authors provide a brief outline of the project and the existing hardware. This is followed by a description of existing redundancy resolution techniques and the impact redundancy has on the success of the project. Finally, preliminary simulation results show the effect cooperative control has on the level of forces generated between the dual-arm systems when coupled by an elastic exhaust hose. These results show a significant reduction in forces when both arms are active and have a combined manipulation strategy.

  14. Functional redundancy and complementarities of seed dispersal by the last neotropical megafrugivores.

    Directory of Open Access Journals (Sweden)

    Rafael S Bueno

    Full Text Available Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris and muriquis (Brachyteles arachnoides are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest.We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest.Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers.

  15. ALGORITMA PENGATURAN KINEMATIKA ROBOT REDUNDANT UNTUK MENGHINDARI TERJADINYA TUMBUKAN BERDASARKAN SKEMA PRIORITAS TUGAS

    Directory of Open Access Journals (Sweden)

    GEDE SANTI ASTAWA

    2012-11-01

    Full Text Available A redundant manipulator has more degree of freedom than minimal needed to do its job. Inthis condition the manipulator can easily do the job, and can say become not optimal. To makethe manipulator more optimal, we try to add some obstacles that must be avoided by themanipulator. in calculation process we use inverse kinematics method in task priority scheme.From the simulation result, it is looked that by adding some jobs do not annoy the main job ofmanipulator, and those prove that the priority of the job can help manipulator do that job moreoptimal.

  16. An examination of cue redundancy theory in cross-cultural decoding of emotions in music.

    Science.gov (United States)

    Kwoun, Soo-Jin

    2009-01-01

    The present study investigated the effects of structural features of music (i.e., variations in tempo, loudness, or articulation, etc.) and cultural and learning factors in the assignments of emotional meaning in music. Four participant groups, young Koreans, young Americans, older Koreans, and older Americans, rated emotional expressions of Korean folksongs with three adjective scales: happiness, sadness and anger. The results of the study are in accordance with the Cue Redundancy model of emotional perception in music, indicating that expressive music embodies both universal auditory cues that communicate the emotional meanings of music across cultures and cultural specific cues that result from cultural convention.

  17. Autonomous navigation - The ARMMS concept. [Autonomous Redundancy and Maintenance Management Subsystem

    Science.gov (United States)

    Wood, L. J.; Jones, J. B.; Mease, K. D.; Kwok, J. H.; Goltz, G. L.; Kechichian, J. A.

    1984-01-01

    A conceptual design is outlined for the navigation subsystem of the Autonomous Redundancy and Maintenance Management Subsystem (ARMMS). The principal function of this navigation subsystem is to maintain the spacecraft over a specified equatorial longitude to within + or - 3 deg. In addition, the navigation subsystem must detect and correct internal faults. It comprises elements for a navigation executive and for orbit determination, trajectory, maneuver planning, and maneuver command. Each of these elements is described. The navigation subsystem is to be used in the DSCS III spacecraft.

  18. Knowledge sharing in construction partnering projects - redundancy, boundary objects and brokers

    DEFF Research Database (Denmark)

    Koch, Christian; Thuesen, Christian

    2013-01-01

    , multiple memberships and different levels of participation, and accompanied by a governance frame. The paper discusses central mechanisms for coordinating knowledge in such a complex construction project. The knowledge relations are conceptualised through focusing on redundancy, understood as negotiated...... is on two dialogue excerpts, one on process, and one on product knowledge exchanges. The diversity and disjunctive feature of the practices form a condition of possibility for knowledge handling and synthesis into the built construct. Relation-based interaction is necessary with boundary objects and brokers...

  19. Inter-computer communication architecture for a mixed redundancy distributed system

    Science.gov (United States)

    Lala, Jaynarayan H.; Adams, Stuart J.

    1987-01-01

    The triply redundant intercomputer network for the Advanced Information Processing System (AIPS), an architecture developed to serve as the core avionics system for a broad range of aerospace vehicles, is discussed. The AIPS intercomputer network provides a high-speed, Byzantine-fault-resilient communication service between processing sites, even in the presence of arbitrary failures of simplex and duplex processing sites on the IC network. The IC network contention poll has evolved from the Laning Poll. An analysis of the failure modes and effects and a simulation of the AIPS contention poll, demonstrate the robustness of the system.

  20. Unified analysis methods for a fault tolerant redundant strapdown inertial measurement unit

    Science.gov (United States)

    Morrell, F. R.; Motyka, P.

    1983-01-01

    The use of a redundant strapdown inertial measurement unit (RSDIMU) has been considered as a source of sensor information for future aircraft. It is pointed out that failure detection and isolation (FDI) should be accomplished at the sensor level to ensure the accurate transfer of information to elements of the integrated avionics system. The present investigation is concerned with the impact of the FDI algorithm on system reliability and vice versa. A description is given of a technique to identify and assess critical areas of reliability requirements for the RSDIMU. Attention is given to the development of an FDI algorithm to meet these requirements.

  1. Single and multi–objective optimization of path placement for redundant robotic manipulators

    Directory of Open Access Journals (Sweden)

    J.A. Pamanes–García

    2008-07-01

    Full Text Available General formulations are presented in this paper to determine the best position and orientation of a desired path to be followed by a redundant manipulator. Two classes of problem are considered. In the first, a single manipulator's index of kinematic performance associated to one path point must be improved as much as possible. In the second case distinct indices of kinematic performance, corresponding to different points of the path, are to be optimized. Constraints are taken into account in order to guarantee the accessibility to the whole de sired task. Several case studies are presented to illustrate the effectiveness of the method for planar and spatial manipulators.

  2. Redundancy of constraints in the classical and quantum theories of gravitation.

    Science.gov (United States)

    Moncrief, V.

    1972-01-01

    It is shown that in Dirac's version of the quantum theory of gravitation, the Hamiltonian constraints are greatly redundant. If the Hamiltonian constraint condition is satisfied at one point on the underlying, closed three-dimensional manifold, then it is automatically satisfied at every point, provided only that the momentum constraints are everywhere satisfied. This permits one to replace the usual infinity of Hamiltonian constraints by a single condition which may be taken in the form of an integral over the manifold. Analogous theorems are given for the classical Einstein Hamilton-Jacobi equations.

  3. Modeling and Control of the Redundant Parallel Adjustment Mechanism on a Deployable Antenna Panel

    Directory of Open Access Journals (Sweden)

    Lili Tian

    2016-10-01

    Full Text Available With the aim of developing multiple input and multiple output (MIMO coupling systems with a redundant parallel adjustment mechanism on the deployable antenna panel, a structural control integrated design methodology is proposed in this paper. Firstly, the modal information from the finite element model of the structure of the antenna panel is extracted, and then the mathematical model is established with the Hamilton principle; Secondly, the discrete Linear Quadratic Regulator (LQR controller is added to the model in order to control the actuators and adjust the shape of the panel. Finally, the engineering practicality of the modeling and control method based on finite element analysis simulation is verified.

  4. An Adaptive Technique for a Redundant-Sensor Navigation System. Ph.D. Thesis

    Science.gov (United States)

    Chien, T. T.

    1972-01-01

    An on-line adaptive technique is developed to provide a self-contained redundant-sensor navigation system with a capability to utilize its full potentiality in reliability and performance. The gyro navigation system is modeled as a Gauss-Markov process, with degradation modes defined as changes in characteristics specified by parameters associated with the model. The adaptive system is formulated as a multistage stochastic process: (1) a detection system, (2) an identification system and (3) a compensation system. It is shown that the sufficient statistics for the partially observable process in the detection and identification system is the posterior measure of the state of degradation, conditioned on the measurement history.

  5. Spatial scaling patterns and functional redundancies in a changing boreal lake landscape

    Science.gov (United States)

    Angeler, David G.; Allen, Craig R.; Uden, Daniel R.; Johnson, Richard K.

    2015-01-01

    Global transformations extend beyond local habitats; therefore, larger-scale approaches are needed to assess community-level responses and resilience to unfolding environmental changes. Using longterm data (1996–2011), we evaluated spatial patterns and functional redundancies in the littoral invertebrate communities of 85 Swedish lakes, with the objective of assessing their potential resilience to environmental change at regional scales (that is, spatial resilience). Multivariate spatial modeling was used to differentiate groups of invertebrate species exhibiting spatial patterns in composition and abundance (that is, deterministic species) from those lacking spatial patterns (that is, stochastic species). We then determined the functional feeding attributes of the deterministic and stochastic invertebrate species, to infer resilience. Between one and three distinct spatial patterns in invertebrate composition and abundance were identified in approximately one-third of the species; the remainder were stochastic. We observed substantial differences in metrics between deterministic and stochastic species. Functional richness and diversity decreased over time in the deterministic group, suggesting a loss of resilience in regional invertebrate communities. However, taxon richness and redundancy increased monotonically in the stochastic group, indicating the capacity of regional invertebrate communities to adapt to change. Our results suggest that a refined picture of spatial resilience emerges if patterns of both the deterministic and stochastic species are accounted for. Spatially extensive monitoring may help increase our mechanistic understanding of community-level responses and resilience to regional environmental change, insights that are critical for developing management and conservation agendas in this current period of rapid environmental transformation.

  6. Selective attention modulates the effect of target location probability on redundant signal processing.

    Science.gov (United States)

    Chang, Ting-Yun; Little, Daniel R; Yang, Cheng-Ta

    2016-08-01

    We investigated the decision process underlying the detection of targets at multiple locations. In three experiments using the same observers, target location probability and attentional instructions were manipulated. A redundant-target detection task was conducted in which participants were required to detect a dot presented at one of two locations. When the dot appeared at the two locations with equal frequency (Experiment 1), those participants who were found to have limited to unlimited capacity were shown to adopt a parallel, self-terminating strategy. By contrast, those participants who had supercapacity were shown to process redundant targets in a coactive manner. When targets were presented with unequal probability, two participants adopted a parallel, self-terminating strategy regardless of whether they were informed the target location probability (Experiment 3) or not (Experiment 2). For the remaining two participants, the strategy changed from parallel, self-terminating to serial, self-terminating as a result of the probability instructions. In Experiments 2 and 3, all the participants were of unlimited to limited capacity. Taken together, these results suggest that target location probability differently affects the selection of a decision strategy and highlight the role of controlled attention in selecting a decision strategy.

  7. A Simple Example of ``Quantum Darwinism'': Redundant Information Storage in Many-Spin Environments

    Science.gov (United States)

    Blume-Kohout, Robin; Zurek, Wojciech H.

    2005-11-01

    As quantum information science approaches the goal of constructing quantum computers, understanding loss of information through decoherence becomes increasingly important. The information about a system that can be obtained from its environment can facilitate quantum control and error correction. Moreover, observers gain most of their information indirectly, by monitoring (primarily photon) environments of the "objects of interest." Exactly how this information is inscribed in the environment is essential for the emergence of "the classical" from the quantum substrate. In this paper, we examine how many-qubit (or many-spin) environments can store information about a single system. The information lost to the environment can be stored redundantly, or it can be encoded in entangled modes of the environment. We go on to show that randomly chosen states of the environment almost always encode the information so that an observer must capture a majority of the environment to deduce the system's state. Conversely, in the states produced by a typical decoherence process, information about a particular observable of the system is stored redundantly. This selective proliferation of "the fittest information" (known as Quantum Darwinism) plays a key role in choosing the preferred, effectively classical observables of macroscopic systems. The developing appreciation that the environment functions not just as a garbage dump, but as a communication channel, is extending our understanding of the environment's role in the quantum-classical transition beyond the traditional paradigm of decoherence.

  8. Functional redundancy and food web functioning in linuron-exposed ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    De Laender, F., E-mail: frederik.delaender@ugent.be [Laboratory of Environmental Toxicity and Aquatic Ecology, Ghent University, Plateaustraat 22, 9000 Ghent (Belgium); Van den Brink, P.J., E-mail: Paul.vandenBrink@wur.nl [Department of Aquatic Ecology and Water Quality Management, Wageningen University, PO Box 47, 6700 AA Wageningen (Netherlands); Janssen, C.R., E-mail: colin.janssen@ugent.be [Laboratory of Environmental Toxicity and Aquatic Ecology, Ghent University, Plateaustraat 22, 9000 Ghent (Belgium)

    2011-10-15

    An extensive data set describing effects of the herbicide linuron on macrophyte-dominated microcosms was analysed with a food web model to assess effects on ecosystem functioning. We showed that sensitive phytoplankton and periphyton groups in the diets of heterotrophs were gradually replaced by more tolerant phytoplankton species as linuron concentrations increased. This diet shift - showing redundancy among phytoplankton species - allowed heterotrophs to maintain their functions in the contaminated microcosms. On an ecosystem level, total gross primary production was up to hundred times lower in the treated microcosms but the uptake of dissolved organic carbon by bacteria and mixotrophs was less sensitive. Food web efficiency was not consistently lower in the treated microcosms. We conclude that linuron predominantly affected the macrophytes but did not alter the overall functioning of the surrounding planktonic food web. Therefore, a risk assessment that protects macrophyte growth also protects the functioning of macrophyte-dominated microcosms. - Highlights: > Food web modelling reveals the functional response of species and ecosystem to linuron. > Primary production was more sensitive to linuron than bacterial production. > Linuron replaced sensitive phytoplankton by tolerant phytoplankton in heterotrophs' diets. > Linuron did not change the functioning of heterotrophs. - Food web modelling reveals functional redundancy of the planktonic community in microcosms treated with linuron.

  9. Genetic redundancy strengthens the circadian clock leading to a narrow entrainment range.

    Science.gov (United States)

    Erzberger, A; Hampp, G; Granada, A E; Albrecht, U; Herzel, H

    2013-07-06

    Circadian clocks are internal timekeepers present in almost all organisms. Driven by a genetic network of highly conserved structure, they generate self-sustained oscillations that entrain to periodic external signals such as the 24 h light-dark cycle. Vertebrates possess multiple, functionally overlapping homologues of the core clock genes. Furthermore, vertebrate clocks entrain to a range of periods three times as narrow as that of other organisms. We asked whether genetic redundancies play a role in governing entrainment properties and analysed locomotor activity rhythms of genetically modified mice lacking one set of clock homologues. Exposing them to non-24 h light-dark cycles, we found that the mutant mice have a wider entrainment range than the wild types. Spectral analysis furthermore revealed nonlinear phenomena of periodically forced self-sustained oscillators for which the entrainment range relates inversely to oscillator amplitude. Using the forced oscillator model to explain the observed differences in entrainment range between mutant and wild-type mice, we sought to quantify the overall oscillator amplitude of their clocks from the activity rhythms and found that mutant mice have weaker circadian clocks than wild types. Our results suggest that genetic redundancy strengthens the circadian clock leading to a narrow entrainment range in vertebrates.

  10. Application of fully stressed design procedures to redundant and non-isotropic structures

    Science.gov (United States)

    Adelman, H. M.; Haftka, R. T.; Tsach, U.

    1980-01-01

    An evaluation is presented of fully stressed design procedures for sizing highly redundant structures including structures made of composite materials. The evaluation is carried out by sizing three structures: a simple box beam of either composite or metal construction; a low aspect ratio titanium wing; and a titanium arrow wing for a conceptual supersonic cruise aircraft. All three structures are sized by ordinary fully-stressed design (FSD) and thermal fully stressed design (TFSD) for combined mechanical and thermal loads. Where possible, designs are checked by applying rigorous mathematical programming techniques to the structures. It is found that FSD and TFSD produce optimum designs for the metal box beam, but produce highly non-optimum designs for the composite box beam. Results from the delta wing and arrow wing indicate that FSD and TFSD exhibits slow convergence for highly redundant metal structures. Further, TFSD exhibits slow oscillatory convergence behavior for the arrow wing for very high temperatures. In all cases where FSD and TFSD perform poorly either in obtaining nonoptimum designs or in converging slowly, the assumptions on which the algorithms are based are grossly violated. The use of scaling, however, is found to be very effective in obtaining fast convergence and efficiently produces safe designs even for those cases when FSD and TFSD alone are ineffective.

  11. Reliable and redundant FPGA based read-out design in the ATLAS TileCal Demonstrator

    CERN Document Server

    Åkerstedt, Henrik; The ATLAS collaboration; Drake, Gary; Anderson, Kelby; Bohm, Christian; Oreglia, Mark; Tang, Fukun

    2015-01-01

    The Tile Calorimeter at ATLAS is a hadron calorimeter based on steel plates and scintillating tiles read out by PMTs. The current read-out system uses standard ADCs and custom ASICs to digitize and temporarily store the data on the detector. However, only a subset of the data is actually read out to the counting room. The on-detector electronics will be replaced around 2023. To achieve the required reliability the upgraded system will be highly redundant. Here the ASICs will be replaced with Kintex-7 FPGAs from Xilinx. This, in addition to the use of multiple 10 Gbps optical read-out links, will allow a full read-out of all detector data. Due to the higher radiation levels expected when the beam luminosity is increased, opportunities for repairs will be less frequent. The circuitry and firmware must therefore be designed for sufficiently high reliability using redundancy and radiation tolerant components. Within a year, a hybrid demonstrator including the new read-out system will be installed in one slice of ...

  12. Choosing non-redundant representative subsets of protein sequence data sets using submodular optimization.

    Science.gov (United States)

    Libbrecht, Maxwell W; Bilmes, Jeffrey A; Noble, William Stafford

    2018-01-18

    Selecting a non-redundant representative subset of sequences is a common step in many bioinformatics workflows, such as the creation of non-redundant training sets for sequence and structural models or selection of "operational taxonomic units" from metagenomics data. Previous methods for this task, such as CD-HIT, PISCES, and UCLUST, apply a heuristic threshold-based algorithm that has no theoretical guarantees. We propose a new approach based on submodular optimization. Submodular optimization, a discrete analogue to continuous convex optimization, has been used with great success for other representative set selection problems. We demonstrate that the submodular optimization approach results in representative protein sequence subsets with greater structural diversity than sets chosen by existing methods, using as a gold standard the SCOPe library of protein domain structures. In this setting, submodular optimization consistently yields protein sequence subsets that include more SCOPe domain families than sets of the same size selected by competing approaches. We also show how the optimization framework allows us to design a mixture objective function that performs well for both large and small representative sets. The framework we describe is the best possible in polynomial time (under some assumptions), and it is flexible and intuitive because it applies a suite of generic methods to optimize one of a variety of objective functions. © 2018 Wiley Periodicals, Inc.

  13. Chaotic Vibration Prediction of a Free-Floating Flexible Redundant Space Manipulator

    Directory of Open Access Journals (Sweden)

    Congqing Wang

    2016-01-01

    Full Text Available The dynamic model of a planar free-floating flexible redundant space manipulator with three joints is derived by the assumed modes method, Lagrange principle, and momentum conservation. According to minimal joint torque’s optimization (MJTO, the state equations of the dynamic model for the free-floating redundant space manipulator are described. The PD control using the tracking position error and velocity error in the manipulator is introduced. Then, the chaotic dynamic behavior of the manipulator is analyzed by chaotic numerical methods, in which time series, phase plane portrait, Poincaré map, and Lyapunov exponents are used to analyze the chaotic behavior of the manipulator. Under certain conditions for the joint torque optimization and initial values, chaotic vibration motion of the space manipulator can be observed. The chaotic time series prediction scheme for the space manipulator is presented based on the theory of phase space reconstruction under Takens’ embedding theorem. The trajectories of phase space can be reconstructed in embedding space, which are equivalent to the original space manipulator in dynamics. The one-step prediction model for the chaotic time series and the chaotic vibration was established by using support vector regression (SVR prediction model with RBF kernel function. It has been proved that the SVR prediction model has a good performance of prediction. The experimental results show the effectiveness of the presented method.

  14. Multiple Description Coding Based on Optimized Redundancy Removal for 3D Depth Map

    Directory of Open Access Journals (Sweden)

    Sen Han

    2016-06-01

    Full Text Available Multiple description (MD coding is a promising alternative for the robust transmission of information over error-prone channels. In 3D image technology, the depth map represents the distance between the camera and objects in the scene. Using the depth map combined with the existing multiview image, it can be efficient to synthesize images of any virtual viewpoint position, which can display more realistic 3D scenes. Differently from the conventional 2D texture image, the depth map contains a lot of spatial redundancy information, which is not necessary for view synthesis, but may result in the waste of compressed bits, especially when using MD coding for robust transmission. In this paper, we focus on the redundancy removal of MD coding based on the DCT (discrete cosine transform domain. In view of the characteristics of DCT coefficients, at the encoder, a Lagrange optimization approach is designed to determine the amounts of high frequency coefficients in the DCT domain to be removed. It is noted considering the low computing complexity that the entropy is adopted to estimate the bit rate in the optimization. Furthermore, at the decoder, adaptive zero-padding is applied to reconstruct the depth map when some information is lost. The experimental results have shown that compared to the corresponding scheme, the proposed method demonstrates better rate central and side distortion performance.

  15. Advanced Launch System Multi-Path Redundant Avionics Architecture Analysis and Characterization

    Science.gov (United States)

    Baker, Robert L.

    1993-01-01

    The objective of the Multi-Path Redundant Avionics Suite (MPRAS) program is the development of a set of avionic architectural modules which will be applicable to the family of launch vehicles required to support the Advanced Launch System (ALS). To enable ALS cost/performance requirements to be met, the MPRAS must support autonomy, maintenance, and testability capabilities which exceed those present in conventional launch vehicles. The multi-path redundant or fault tolerance characteristics of the MPRAS are necessary to offset a reduction in avionics reliability due to the increased complexity needed to support these new cost reduction and performance capabilities and to meet avionics reliability requirements which will provide cost-effective reductions in overall ALS recurring costs. A complex, real-time distributed computing system is needed to meet the ALS avionics system requirements. General Dynamics, Boeing Aerospace, and C.S. Draper Laboratory have proposed system architectures as candidates for the ALS MPRAS. The purpose of this document is to report the results of independent performance and reliability characterization and assessment analyses of each proposed candidate architecture and qualitative assessments of testability, maintainability, and fault tolerance mechanisms. These independent analyses were conducted as part of the MPRAS Part 2 program and were carried under NASA Langley Research Contract NAS1-17964, Task Assignment 28.

  16. Motion Planning of Redundant Manipulators for Painting Uniform Thick Coating in Irregular Duct

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2016-01-01

    Full Text Available The paper presents a motion planning method of redundant manipulator for painting uniform thick coating on the interior of irregular duct of some aircrafts. Discontinuous peripheral painting method is employed by analyzing the restrictions during painting the duct. For improving the longitudinal uniformity of thick coating, the interlacing painting method plans two sets of sweeping paths and an interlacing distance between the starting paths of the two times of painting. The interlacing distance and overlapping distance are optimized by establishing and analyzing the model of longitudinal uniformity. To enhance the transverse uniformity, sweeping speeds for curved surfaces are calculated by the ratio of transfer efficiency after the basic sweeping speed for the plane is determined. The intertwining method, minimizing the sum of the weighed distances between the duct centerline and key points of the manipulator links, is employed for the joint trajectory planning without collision. The simulation and experiment results show that the redundant manipulators can finish painting the internal surface of the irregular S-shaped duct without collision. The maximum relative deviation is 16.3% and the thicknesses of all measurement points satisfy the acceptance criteria of the factory.

  17. The Precollision Trajectory Planning of Redundant Space Manipulator for Capture Task

    Directory of Open Access Journals (Sweden)

    Long Zhang

    2014-02-01

    Full Text Available Aiming at on-orbit capture task, a scheme for precollision trajectory planning of redundant space manipulator is proposed in this paper. The minimized collision impulsive force and the correct capture pose of the end-effector can be achieved at the same time by the scheme. At the contact point, the configuration of the manipulator is optimized in a new way to minimize the impulsive force without affecting the correct capture pose. After obtaining the optimal configuration, particle swarm optimization (PSO algorithm is employed to solve the trajectory planning from the initial point to the desired point (desired configuration and correct capture pose are both contained. Firstly, the joint trajectory is parameterized using sinusoidal functions with the arguments of high-order polynomials. Then the objective function is defined according to the end-effector pose requirements. Finally, the PSO method is used to search for the unknown parameters to obtain the appropriate precollision joint trajectory. The proposed method can satisfy the whole capture process of redundant space manipulator before collision, and simulation results of a 7-dof space manipulator verify the effectiveness.

  18. Metabolic pathway redundancy within the apicomplexan-dinoflagellate radiation argues against an ancient chromalveolate plastid

    KAUST Repository

    Waller, Ross F.

    2015-12-08

    The chromalveolate hypothesis presents an attractively simple explanation for the presence of red algal-derived secondary plastids in 5 major eukaryotic lineages: “chromista” phyla, cryptophytes, haptophytes and ochrophytes; and alveolate phyla, dinoflagellates and apicomplexans. It posits that a single secondary endosymbiotic event occurred in a common ancestor of these diverse groups, and that this ancient plastid has since been maintained by vertical inheritance only. Substantial testing of this hypothesis by molecular phylogenies has, however, consistently failed to provide support for the predicted monophyly of the host organisms that harbour these plastids—the “chromalveolates.” This lack of support does not disprove the chromalveolate hypothesis per se, but rather drives the proposed endosymbiosis deeper into the eukaryotic tree, and requires multiple plastid losses to have occurred within intervening aplastidic lineages. An alternative perspective on plastid evolution is offered by considering the metabolic partnership between the endosymbiont and its host cell. A recent analysis of metabolic pathways in a deep-branching dinoflagellate indicates a high level of pathway redundancy in the common ancestor of apicomplexans and dinoflagellates, and differential losses of these pathways soon after radiation of the major extant lineages. This suggests that vertical inheritance of an ancient plastid in alveolates is highly unlikely as it would necessitate maintenance of redundant pathways over very long evolutionary timescales.

  19. Classical Branch Structure from Spatial Redundancy in a Many-Body Wave Function

    Science.gov (United States)

    Riedel, C. Jess

    2017-03-01

    When the wave function of a large quantum system unitarily evolves away from a low-entropy initial state, there is strong circumstantial evidence it develops "branches": a decomposition into orthogonal components that is indistinguishable from the corresponding incoherent mixture with feasible observations. Is this decomposition unique? Must the number of branches increase with time? These questions are hard to answer because there is no formal definition of branches, and most intuition is based on toy models with arbitrarily preferred degrees of freedom. Here, assuming only the tensor structure associated with spatial locality, I show that branch decompositions are highly constrained just by the requirement that they exhibit redundant local records. The set of all redundantly recorded observables induces a preferred decomposition into simultaneous eigenstates unless their records are highly extended and delicately overlapping, as exemplified by the Shor error-correcting code. A maximum length scale for records is enough to guarantee uniqueness. Speculatively, objective branch decompositions may speed up numerical simulations of nonstationary many-body states, illuminate the thermalization of closed systems, and demote measurement from fundamental primitive in the quantum formalism.

  20. Physiological hemostasis based intelligent integrated cooperative controller for precise fault-tolerant control of redundant parallel manipulator

    Science.gov (United States)

    Hao, Kuangrong; Guo, Chongbin; Ding, Yongsheng

    2014-10-01

    This paper focuses on precise fault-tolerant control for actual redundant parallel manipulator. Based on kinematic redundancy, some unnoticed influences such as mechanical clearance have been considered to design a more precise and intelligent fault-tolerant plan for actual plants. According to regulation principles in human hemostasis system, a bio-inspired intelligent integrated cooperative controller (BIICC) is developed including system structure, algorithm and step in parameter tuning. The proposed BIICC optimises partial error signal and improves control performance in each sub-channel. Moreover, the new controller transfers and disposes cooperative control signals among different sub-channels to achieve an intelligent integrated fault-tolerant system. The proposed BIICC is applied to an actual 2-DOF (degrees of freedom) redundant parallel manipulator where the feasibility of the new controller is demonstrated. The BIICC is beneficial to control precision and fault-tolerant capability of redundant plant. The improvements are more obvious in cases where extra actuators of redundant manipulator are broken.

  1. A New Biobjective Model to Optimize Integrated Redundancy Allocation and Reliability-Centered Maintenance Problems in a System Using Metaheuristics

    Directory of Open Access Journals (Sweden)

    Shima MohammadZadeh Dogahe

    2015-01-01

    Full Text Available A novel integrated model is proposed to optimize the redundancy allocation problem (RAP and the reliability-centered maintenance (RCM simultaneously. A system of both repairable and nonrepairable components has been considered. In this system, electronic components are nonrepairable while mechanical components are mostly repairable. For nonrepairable components, a redundancy allocation problem is dealt with to determine optimal redundancy strategy and number of redundant components to be implemented in each subsystem. In addition, a maintenance scheduling problem is considered for repairable components in order to identify the best maintenance policy and optimize system reliability. Both active and cold standby redundancy strategies have been taken into account for electronic components. Also, net present value of the secondary cost including operational and maintenance costs has been calculated. The problem is formulated as a biobjective mathematical programming model aiming to reach a tradeoff between system reliability and cost. Three metaheuristic algorithms are employed to solve the proposed model: Nondominated Sorting Genetic Algorithm (NSGA-II, Multiobjective Particle Swarm Optimization (MOPSO, and Multiobjective Firefly Algorithm (MOFA. Several test problems are solved using the mentioned algorithms to test efficiency and effectiveness of the solution approaches and obtained results are analyzed.

  2. A highly redundant BAC library of Atlantic salmon (Salmo salar: an important tool for salmon projects

    Directory of Open Access Journals (Sweden)

    Koop Ben F

    2005-04-01

    Full Text Available Abstract Background As farming of Atlantic salmon is growing as an aquaculture enterprise, the need to identify the genomic mechanisms for specific traits is becoming more important in breeding and management of the animal. Traits of importance might be related to growth, disease resistance, food conversion efficiency, color or taste. To identify genomic regions responsible for specific traits, genomic large insert libraries have previously proven to be of crucial importance. These large insert libraries can be screened using gene or genetic markers in order to identify and map regions of interest. Furthermore, large-scale mapping can utilize highly redundant libraries in genome projects, and hence provide valuable data on the genome structure. Results Here we report the construction and characterization of a highly redundant bacterial artificial chromosome (BAC library constructed from a Norwegian aquaculture strain male of Atlantic salmon (Salmo salar. The library consists of a total number of 305 557 clones, in which approximately 299 000 are recombinants. The average insert size of the library is 188 kbp, representing 18-fold genome coverage. High-density filters each consisting of 18 432 clones spotted in duplicates have been produced for hybridization screening, and are publicly available 1. To characterize the library, 15 expressed sequence tags (ESTs derived overgos and 12 oligo sequences derived from microsatellite markers were used in hybridization screening of the complete BAC library. Secondary hybridizations with individual probes were performed for the clones detected. The BACs positive for the EST probes were fingerprinted and mapped into contigs, yielding an average of 3 contigs for each probe. Clones identified using genomic probes were PCR verified using microsatellite specific primers. Conclusion Identification of genes and genomic regions of interest is greatly aided by the availability of the CHORI-214 Atlantic salmon BAC

  3. Non-random food-web assembly at habitat edges increases connectivity and functional redundancy.

    Science.gov (United States)

    Peralta, Guadalupe; Frost, Carol M; Didham, Raphael K; Rand, Tatyana A; Tylianakis, Jason M

    2017-04-01

    Habitat fragmentation dramatically alters the spatial configuration of landscapes, with the creation of artificial edges affecting community structure and dynamics. Despite this, it is not known how the different food webs in adjacent habitats assemble at their boundaries. Here we demonstrate that the composition and structure of herbivore-parasitoid food webs across edges between native and plantation forests are not randomly assembled from those of the adjacent communities. Rather, elevated proportions of abundant, interaction-generalist parasitoid species at habitat edges allowed considerable interaction rewiring, which led to higher linkage density and less modular networks, with higher parasitoid functional redundancy. This was despite high overlap in host composition between edges and interiors. We also provide testable hypotheses for how food webs may assemble between habitats with lower species overlap. In an increasingly fragmented world, non-random assembly of food webs at edges may increasingly affect community dynamics at the landscape level. © 2016 by the Ecological Society of America.

  4. Towards Extending Forward Kinematic Models on Hyper-Redundant Manipulator to Cooperative Bionic Arms

    Science.gov (United States)

    Singh, Inderjeet; Lakhal, Othman; Merzouki, Rochdi

    2017-01-01

    Forward Kinematics is a stepping stone towards finding an inverse solution and subsequently a dynamic model of a robot. Hence a study and comparison of various Forward Kinematic Models (FKMs) is necessary for robot design. This paper deals with comparison of three FKMs on the same hyper-redundant Compact Bionic Handling Assistant (CBHA) manipulator under same conditions. The aim of this study is to project on modeling cooperative bionic manipulators. Two of these methods are quantitative methods, Arc Geometry HTM (Homogeneous Transformation Matrix) Method and Dual Quaternion Method, while the other one is Hybrid Method which uses both quantitative as well as qualitative approach. The methods are compared theoretically and experimental results are discussed to add further insight to the comparison. HTM is the widely used and accepted technique, is taken as reference and trajectory deviation in other techniques are compared with respect to HTM. Which method allows obtaining an accurate kinematic behavior of the CBHA, controlled in the real-time.

  5. Extensive screening for primary tumor is redundant in melanoma of unknown primary

    DEFF Research Database (Denmark)

    Tos, Tina; Klyver, Helle; Drzewiecki, Krzysztof T

    2011-01-01

    primary tumor during the period 1986-2006, 39 (38%) presented primarily with a cutaneous or a subcutaneous metastasis, and 63 (61%) with a lymph node metastasis. One patient presented with a bone metastasis (1%). Eighty-seven patients (84%) were examined by an ophthalmologist. A choroidal melanoma......For decades, patients in our institution with metastastic melanoma of unknown primary have been subjected to extensive examinations in search of the primary tumor. This retrospective study questions the results, and thus the feasibility of these examinations. Of 103 patients diagnosed with unknown...... (89%), revealing no primary tumor. We conclude, that only one possible (but not verified) primary tumor was disclosed by various specialists examinations of 103 patients referred with the diagnosis metastatic melanoma with no primary tumor. Special screenings can thus be considered as redundant. Thus...

  6. Secure, Redundant, and Fully Distributed Key Management Scheme for Mobile Ad Hoc Networks: An Analysis

    Directory of Open Access Journals (Sweden)

    Joshi Deepti

    2005-01-01

    Full Text Available Security poses a major challenge in ad hoc networks today due to the lack of fixed or organizational infrastructure. This paper proposes a modification to the existing "fully distributed certificate authority" scheme for ad hoc networks. In the proposed modification, redundancy is introduced by allocating more than one share to each node in order to increase the probability of creating the certificate for a node in a highly mobile network. A probabilistic analysis is carried out to analyze the trade-offs between the ease of certificate creation and the security provided by the proposed scheme. The analysis carried out from the intruder's perspective suggests that in the worst-case scenario, the intruder is just "one node" away from a legitimate node in compromising the certificate. The analysis also outlines the parameter selection criteria for a legitimate node to maintain a margin of advantage over an intruder in creating the certificate.

  7. Double Fault Detection of Cone-Shaped Redundant IMUs Using Wavelet Transformation and EPSA

    Directory of Open Access Journals (Sweden)

    Wonhee Lee

    2014-02-01

    Full Text Available A model-free hybrid fault diagnosis technique is proposed to improve the performance of single and double fault detection and isolation. This is a model-free hybrid method which combines the extended parity space approach (EPSA with a multi-resolution signal decomposition by using a discrete wavelet transform (DWT. Conventional EPSA can detect and isolate single and double faults. The performance of fault detection and isolation is influenced by the relative size of noise and fault. In this paper; the DWT helps to cancel the high frequency sensor noise. The proposed technique can improve low fault detection and isolation probability by utilizing the EPSA with DWT. To verify the effectiveness of the proposed fault detection method Monte Carlo numerical simulations are performed for a redundant inertial measurement unit (RIMU.

  8. General-Weighted Least-Norm Control for Redundant Manipulators under Time-Dependent Constraint

    Directory of Open Access Journals (Sweden)

    Pei Jiang

    2015-05-01

    Full Text Available Previous research dealing with constrained kinematic redundancy problems focuses on manipulators with time-independent constraints. This paper extends the general-weighted least-norm (GWLN method to manipulators with time-dependent constraints by introducing time-dependent virtual joints. In the virtual joint space, corresponding task space velocity is revised to encapsulate the effects of time-dependent parameters of constraints. This is done so that an intermediate kinematic control problem with only joint limit is obtained. Then, the inverse kinematic problem is solved in the virtual joint space. A new inverse-weighted matrix setting criterion is proposed to replace the one-step prediction that originally complicated implementation of the GWLN method. To demonstrate the efficacy of the method, simulations and experiments are carried out on a five-link welding manipulator to track the welding trajectory. Time-dependent orientation constraint and preventing joint limits is guaranteed using this method.

  9. Comparative analysis of profit between three dissimilar repairable redundant systems using supporting external device for operation

    Science.gov (United States)

    Yusuf, Ibrahim

    2014-07-01

    The importance in promoting, sustaining industries, manufacturing systems and economy through reliability measurement has become an area of interest. The profit of a system may be enhanced using highly reliable structural design of the system or subsystem of higher reliability. On improving the reliability and availability of a system, the production and associated profit will also increase. Reliability, availability and profit are some of the most important factors in any successful industry and manufacturing settings. In this paper, we compare three different repairable redundant systems using an external supporting device for operation based on the profit. Explicit expressions for the busy period of repairmen, steady-state availability and profit function are derived using linear first-order differential equations. Furthermore, we compare the profit for the three systems and find that system I is more profitable than systems II and III.

  10. Sensitivity to Error Tolerant Solutions in a Redundant Virtual Throwing Task

    Directory of Open Access Journals (Sweden)

    Müller Hermann

    2011-12-01

    Full Text Available It is suggested that when learning a redundant goaloriented motor task, people explore and choose error tolerant solutions of the task to reduce result variability. This assumption was tested with a virtual throwing task where the error tolerant solutions were designed such that subjects needed to recurrently adapt to a new tolerant solution in order to achieve high performance. We tested 13 participants who practiced the task over six days. All of them adapted to changes in error tolerant solutions although the absolute number of adaptations as well as the rate of adaptation varied strongly between subjects. Results are discussed with reference to motor noise and the integration of practice trials according to error probability.

  11. Stationarity and Redundancy of Multichannel EEG Data Recorded During Generalized Tonic-Clonic Seizures

    CERN Document Server

    Zöldi, S M; Greenside, H S; Zoldi, Scott M.; Krystal, Andrew; Greenside, Henry S.

    1999-01-01

    A prerequisite for applying some signal analysis methods to electroencephalographic (EEG) data is that the data be statistically stationary. We have investigated the stationarity of 21-electrode multivariate EEG data recorded from ten patients during generalized tonic-clonic (GTC) seizures elicited by electroconvulsive therapy (ECT). Stationarity was examined by calculating probability density functions (pdfs) and power spectra over small equal-length non-overlapping time windows and then by studying visually and quantitatively the evolution of these quantities over the duration of the seizures. Our analysis shows that most of the seizures had time intervals of at least a few seconds that were statistically stationary by several criteria and simultaneously for different electrodes, and that some leads were delayed in manifesting the statistical changes associated with seizure onset evident in other leads. The stationarity across electrodes was further examined by studying redundancy of the EEG leads and how t...

  12. Failure detection and isolation analysis of a redundant strapdown inertial measurement unit

    Science.gov (United States)

    Motyka, P.; Landey, M.; Mckern, R.

    1981-01-01

    The objective of this study was to define and develop techniques for failure detection and isolation (FDI) algorithms for a dual fail/operational redundant strapdown inertial navigation system are defined and developed. The FDI techniques chosen include provisions for hard and soft failure detection in the context of flight control and navigation. Analyses were done to determine error detection and switching levels for the inertial navigation system, which is intended for a conventional takeoff or landing (CTOL) operating environment. In addition, investigations of false alarms and missed alarms were included for the FDI techniques developed, along with the analyses of filters to be used in conjunction with FDI processing. Two specific FDI algorithms were compared: the generalized likelihood test and the edge vector test. A deterministic digital computer simulation was used to compare and evaluate the algorithms and FDI systems.

  13. Multi-Objective Genetic Programming with Redundancy-Regulations for Automatic Construction of Image Feature Extractors

    Science.gov (United States)

    Watchareeruetai, Ukrit; Matsumoto, Tetsuya; Takeuchi, Yoshinori; Kudo, Hiroaki; Ohnishi, Noboru

    We propose a new multi-objective genetic programming (MOGP) for automatic construction of image feature extraction programs (FEPs). The proposed method was originated from a well known multi-objective evolutionary algorithm (MOEA), i.e., NSGA-II. The key differences are that redundancy-regulation mechanisms are applied in three main processes of the MOGP, i.e., population truncation, sampling, and offspring generation, to improve population diversity as well as convergence rate. Experimental results indicate that the proposed MOGP-based FEP construction system outperforms the two conventional MOEAs (i.e., NSGA-II and SPEA2) for a test problem. Moreover, we compared the programs constructed by the proposed MOGP with four human-designed object recognition programs. The results show that the constructed programs are better than two human-designed methods and are comparable with the other two human-designed methods for the test problem.

  14. Analysis of Tensegrity Structures with Redundancies, by Implementing a Comprehensive Equilibrium Equations Method with Force Densities

    Directory of Open Access Journals (Sweden)

    Miltiades Elliotis

    2016-01-01

    Full Text Available A general approach is presented to analyze tensegrity structures by examining their equilibrium. It belongs to the class of equilibrium equations methods with force densities. The redundancies are treated by employing Castigliano’s second theorem, which gives the additional required equations. The partial derivatives, which appear in the additional equations, are numerically replaced by statically acceptable internal forces which are applied on the structure. For both statically determinate and indeterminate tensegrity structures, the properties of the resulting linear system of equations give an indication about structural stability. This method requires a relatively small number of computations, it is direct (there is no iteration procedure and calculation of auxiliary parameters and is characterized by its simplicity. It is tested on both 2D and 3D tensegrity structures. Results obtained with the method compare favorably with those obtained by the Dynamic Relaxation Method or the Adaptive Force Density Method.

  15. Robust and Cooperative Image-Based Visual Servoing System Using a Redundant Architecture

    Directory of Open Access Journals (Sweden)

    Francisco J. Badesa

    2011-12-01

    Full Text Available The reliability and robustness of image-based visual servoing systems is still unsolved by the moment. In order to address this issue, a redundant and cooperative 2D visual servoing system based on the information provided by two cameras in eye-in-hand/eye-to-hand configurations is proposed. Its control law has been defined to assure that the whole system is stable if each subsystem is stable and to allow avoiding typical problems of image-based visual servoing systems like task singularities, features extraction errors, disappearance of image features, local minima, etc. Experimental results with an industrial robot manipulator based on Schunk modular motors to demonstrate the stability, performance and robustness of the proposed system are presented.

  16. GenMiner: mining non-redundant association rules from integrated gene expression data and annotations.

    Science.gov (United States)

    Martinez, Ricardo; Pasquier, Nicolas; Pasquier, Claude

    2008-11-15

    GenMiner is an implementation of association rule discovery dedicated to the analysis of genomic data. It allows the analysis of datasets integrating multiple sources of biological data represented as both discrete values, such as gene annotations, and continuous values, such as gene expression measures. GenMiner implements the new NorDi (normal discretization) algorithm for normalizing and discretizing continuous values and takes advantage of the Close algorithm to efficiently generate minimal non-redundant association rules. Experiments show that execution time and memory usage of GenMiner are significantly smaller than those of the standard Apriori-based approach, as well as the number of extracted association rules. The GenMiner software and supplementary materials are available at http://bioinfo.unice.fr/publications/genminer_article/ and http://keia.i3s.unice.fr/?Implementations:GenMiner Supplementary data are available at Bioinformatics online.

  17. [Relationships between soil and rocky desertification in typical karst mountain area based on redundancy analysis].

    Science.gov (United States)

    Long, Jian; Liao, Hong-Kai; Li, Juan; Chen, Cai-Yun

    2012-06-01

    Redundancy analysis (RDA) was employed to reveal the relationships between soil and rocky desertification through vegetation investigation and analysis of soil samples collected in typical karst mountain area of southwest Guizhou Province. The results showed that except TP, TK and ACa, all other variables including SOC, TN, MBC, ROC, DOC, available nutrients and basal respiration showed significant downward trends during the rocky desertification process. RDA results showed significant correlations between different types of desertification and soil variables, described as non-degraded > potential desertification > light desertification > moderate desertification > severe desertification. Moreover, RDA showed that using SOC, TN, AN, and BD as soil indicators, 74.4% of the variance information on soil and rocky desertification could be explained. Furthermore, the results of correlation analysis showed that soil variables were significantly affected by surface vegetation. Considering the ecological function of the aboveground vegetation and the soil quality, Zanthoxylum would be a good choice for restoration of local vegetation in karst mountain area.

  18. Redundancy management of multiple KT-70 inertial measurement units applicable to the space shuttle

    Science.gov (United States)

    Cook, L. J.

    1975-01-01

    Results of an investigation of velocity failure detection and isolation for 3 inertial measuring units (IMU) and 2 inertial measuring units (IMU) configurations are presented. The failure detection and isolation algorithm performance was highly successful and most types of velocity errors were detected and isolated. The failure detection and isolation algorithm also included attitude FDI but was not evaluated because of the lack of time and low resolution in the gimbal angle synchro outputs. The shuttle KT-70 IMUs will have dual-speed resolvers and high resolution gimbal angle readouts. It was demonstrated by these tests that a single computer utilizing a serial data bus can successfully control a redundant 3-IMU system and perform FDI.

  19. Failure detection and isolation methods for redundant gimballed inertial measurement units.

    Science.gov (United States)

    Solov, E. G.; Thibodeau, J. R., III

    1973-01-01

    Skewed alignment of two redundant conventional inertial measuring units permits nonambiguous detection and isolation of hard and soft failures in real time by an airborne computer. Accelerometer outputs and gimbal readouts are monitored periodically, and attitude rate and velocity error vectors are computed from these data. Magnitudes of these vectors provide failure detection, and projection of these error vectors onto the coordinate axes of the two clusters permits isolation. A detailed Monte Carlo simulation of one version of the mechanization as applied to Space Shuttle boost trajectories demonstrates effectiveness down to very low levels of inertial instrument performance failures. The results indicate that worst case overall navigation performance occurs when accelerometer failures are of the order of 20 sigma and gyro failures are about 100 sigma for conventional state-of-the-art IMU instruments.

  20. Two enzymes with redundant fructose bisphosphatase activity sustain gluconeogenesis and virulence in Mycobacterium tuberculosis.

    Science.gov (United States)

    Ganapathy, Uday; Marrero, Joeli; Calhoun, Susannah; Eoh, Hyungjin; de Carvalho, Luiz Pedro Sorio; Rhee, Kyu; Ehrt, Sabine

    2015-08-10

    The human pathogen Mycobacterium tuberculosis (Mtb) likely utilizes host fatty acids as a carbon source during infection. Gluconeogenesis is essential for the conversion of fatty acids into biomass. A rate-limiting step in gluconeogenesis is the conversion of fructose 1,6-bisphosphate to fructose 6-phosphate by a fructose bisphosphatase (FBPase). The Mtb genome contains only one annotated FBPase gene, glpX. Here we show that, unexpectedly, an Mtb mutant lacking GLPX grows on gluconeogenic carbon sources and has detectable FBPase activity. We demonstrate that the Mtb genome encodes an alternative FBPase (GPM2, Rv3214) that can maintain gluconeogenesis in the absence of GLPX. Consequently, deletion of both GLPX and GPM2 is required for disruption of gluconeogenesis and attenuation of Mtb in a mouse model of infection. Our work affirms a role for gluconeogenesis in Mtb virulence and reveals previously unidentified metabolic redundancy at the FBPase-catalysed reaction step of the pathway.

  1. Optimal Point-to-Point Trajectory Tracking of Redundant Manipulators using Generalized Pattern Search

    Directory of Open Access Journals (Sweden)

    Thi Rein Myo

    2008-11-01

    Full Text Available Optimal point-to-point trajectory planning for planar redundant manipulator is considered in this study. The main objective is to minimize the sum of the position error of the end-effector at each intermediate point along the trajectory so that the end-effector can track the prescribed trajectory accurately. An algorithm combining Genetic Algorithm and Pattern Search as a Generalized Pattern Search GPS is introduced to design the optimal trajectory. To verify the proposed algorithm, simulations for a 3-D-O-F planar manipulator with different end-effector trajectories have been carried out. A comparison between the Genetic Algorithm and the Generalized Pattern Search shows that The GPS gives excellent tracking performance.

  2. Unified performance analysis of hybrid-ARQ with incremental redundancy over free-space optical channels

    KAUST Repository

    Zedini, Emna

    2014-09-01

    In this paper, we carry out a unified performance analysis of hybrid automatic repeat request (HARQ) with incremental redundancy (IR) from an information theoretic perspective over a point-to-point free-space optical (FSO) system. First, we introduce a novel unified expression for the distribution of a single FSO link modeled by the Gamma fading that accounts for pointing errors subject to both types of detection techniques at the receiver side (i.e. heterodyne detection and intensity modulation with direct detection (IM/DD)). Then, we provide analytical expressions for the outage probability, the average number of transmissions, and the average transmission rate for HARQ with IR, assuming a maximum number of rounds for the HARQ protocol. In our study, the communication rate per HARQ round is constant. Our analysis demonstrates the importance of HARQ in improving the performance and reliability of FSO communication systems. All the given results are verified via computer-based Monte-Carlo simulations.

  3. Redundant manipulator techniques for partially decentralized path planning and control of a platoon of autonomous vehicles.

    Science.gov (United States)

    Stilwell, Daniel J; Bishop, Bradley E; Sylvester, Caleb A

    2005-08-01

    An approach to real-time trajectory generation for platoons of autonomous vehicles is developed from well-known control techniques for redundant robotic manipulators. The partially decentralized structure of this approach permits each vehicle to independently compute its trajectory in real-time using only locally generated information and low-bandwidth feedback generated by a system exogenous to the platoon. Our work is motivated by applications for which communications bandwidth is severely limited, such for platoons of autonomous underwater vehicles. The communication requirements for our trajectory generation approach are independent of the number of vehicles in the platoon, enabling platoons composed of a large number of vehicles to be coordinated despite limited communication bandwidth.

  4. Data Reduction and Image Reconstruction Techniques for Non-redundant Masking

    Science.gov (United States)

    Sallum, S.; Eisner, J.

    2017-11-01

    The technique of non-redundant masking (NRM) transforms a conventional telescope into an interferometric array. In practice, this provides a much better constrained point-spread function than a filled aperture and thus higher resolution than traditional imaging methods. Here, we describe an NRM data reduction pipeline. We discuss strategies for NRM observations regarding dithering patterns and calibrator selection. We describe relevant image calibrations and use example Large Binocular Telescope data sets to show their effects on the scatter in the Fourier measurements. We also describe the various ways to calculate Fourier quantities, and discuss different calibration strategies. We present the results of image reconstructions from simulated observations where we adjust prior images, weighting schemes, and error bar estimation. We compare two imaging algorithms and discuss implications for reconstructing images from real observations. Finally, we explore how the current state of the art compares to next-generation Extremely Large Telescopes.

  5. Optimum allocation of redundancy among subsystems connected in series. Ph.D. Thesis - Case Western Reserve Univ., Sep. 1970

    Science.gov (United States)

    Bien, D. D.

    1973-01-01

    This analysis considers the optimum allocation of redundancy in a system of serially connected subsystems in which each subsystem is of the k-out-of-n type. Redundancy is optimally allocated when: (1) reliability is maximized for given costs; or (2) costs are minimized for given reliability. Several techniques are presented for achieving optimum allocation and their relative merits are discussed. Approximate solutions in closed form were attainable only for the special case of series-parallel systems and the efficacy of these approximations is discussed.

  6. Ambiguity attacks on robust blind image watermarking scheme based on redundant discrete wavelet transform and singular value decomposition

    Directory of Open Access Journals (Sweden)

    Khaled Loukhaoukha

    2017-12-01

    Full Text Available Among emergent applications of digital watermarking are copyright protection and proof of ownership. Recently, Makbol and Khoo (2013 have proposed for these applications a new robust blind image watermarking scheme based on the redundant discrete wavelet transform (RDWT and the singular value decomposition (SVD. In this paper, we present two ambiguity attacks on this algorithm that have shown that this algorithm fails when used to provide robustness applications like owner identification, proof of ownership, and transaction tracking. Keywords: Ambiguity attack, Image watermarking, Singular value decomposition, Redundant discrete wavelet transform

  7. A 12bits 40MSPS SAR ADC with a redundancy algorithm and digital calibration for the ATLAS LAr calorimeter readout

    CERN Document Server

    Zeloufi, Mohamed; The ATLAS collaboration; Rarbi, Fatah-ellah

    2015-01-01

    We present a SAR ADC with a generalized redundant search algorithm offering the flexibility to relax the requirements on the DAC settling time. The redundancy allows also a digital background calibration, based on a code density analysis, to compensate the capacitors mismatching effects. The total of capacitors used in this architecture is limited to a half of the one in a classical SAR design. Only 2^11 unit capacitors were necessary to reach 12bits resolution, and the switching algorithm is intrinsically monotonic. The design is fully differential featuring 12-bit 40MS/s in a CMOS 130nm 1P8M process.

  8. A 12bits 40MSPS SAR ADC with a redundancy algorithm and digital calibration for the ATLAS LArg calorimeter readout

    CERN Document Server

    Zeloufi, Mohamed; The ATLAS collaboration; Rarbi, Fatah-ellah

    2015-01-01

    This paper presents a SAR ADC with a generalized redundant search algorithm offering the flexibility to relax the requirements on the DAC settling time. The redundancy allows also a digital background calibration, based on a code density analysis, to compensate the capacitors mismatching effects. The total of capacitors used in this architecture is limited to a half of the one in a classical SAR design. Only 211 unit capacitors were necessary to reach 12bit resolution, and the switching algorithm is intrinsically monotonic. The design is fully differential featuring 12-bit 40MS/s in a CMOS 130nm 1P8M process.

  9. Description of a dual fail-operational redundant strapdown inertial measurement unit for integrated avionics systems research

    Science.gov (United States)

    Bryant, W. H.; Morrell, F. R.

    1981-01-01

    Attention is given to a redundant strapdown inertial measurement unit for integrated avionics. The system consists of four two-degree-of-freedom turned rotor gyros and four two-degree-of-freedom accelerometers in a skewed and separable semi-octahedral array. The unit is coupled through instrument electronics to two flight computers which compensate sensor errors. The flight computers are interfaced to the microprocessors and process failure detection, isolation, redundancy management and flight control/navigation algorithms. The unit provides dual fail-operational performance and has data processing frequencies consistent with integrated avionics concepts presently planned.

  10. Different-Level Simultaneous Minimization Scheme for Fault Tolerance of Redundant Manipulator Aided with Discrete-Time Recurrent Neural Network

    Directory of Open Access Journals (Sweden)

    Long Jin

    2017-09-01

    Full Text Available By incorporating the physical constraints in joint space, a different-level simultaneous minimization scheme, which takes both the robot kinematics and robot dynamics into account, is presented and investigated for fault-tolerant motion planning of redundant manipulator in this paper. The scheme is reformulated as a quadratic program (QP with equality and bound constraints, which is then solved by a discrete-time recurrent neural network. Simulative verifications based on a six-link planar redundant robot manipulator substantiate the efficacy and accuracy of the presented acceleration fault-tolerant scheme, the resultant QP and the corresponding discrete-time recurrent neural network.

  11. Different-Level Simultaneous Minimization Scheme for Fault Tolerance of Redundant Manipulator Aided with Discrete-Time Recurrent Neural Network.

    Science.gov (United States)

    Jin, Long; Liao, Bolin; Liu, Mei; Xiao, Lin; Guo, Dongsheng; Yan, Xiaogang

    2017-01-01

    By incorporating the physical constraints in joint space, a different-level simultaneous minimization scheme, which takes both the robot kinematics and robot dynamics into account, is presented and investigated for fault-tolerant motion planning of redundant manipulator in this paper. The scheme is reformulated as a quadratic program (QP) with equality and bound constraints, which is then solved by a discrete-time recurrent neural network. Simulative verifications based on a six-link planar redundant robot manipulator substantiate the efficacy and accuracy of the presented acceleration fault-tolerant scheme, the resultant QP and the corresponding discrete-time recurrent neural network.

  12. MEMS-based redundancy ring for low-noise millimeter-wave front-end

    Science.gov (United States)

    Pons, Patrick; Dubuc, David; Flourens, Federic; Saddaoui, Mohammad; Melle, Samuel; Tackacs, Alex; Tao, Junwu; Aubert, Herve; Boukabache, Ali; Paillot, T.; Blondy, Pierre; Vendier, Olivier; Grenier, Katia M.; Plana, Robert

    2004-08-01

    This paper reports on the investigation of the potentialities of the MEMS technologies to develop innovative microsystem for millimetre wave communication essentially for space applications. One main issue deals with the robustness and the reliability of the equipment as it may difficult to replace or to repair them when a satellite has been launched. One solution deals with the development of redundancy rings that are making the front end more robust. Usually, the architecture of such system involves waveguide or diode technologies, which present severe limitations in term of weight, volume and insertion loss. The concept considered in this paper is to replace some key elements of such system by MEMS based devices (Micromachined transmission lines, switches) in order to optimize both the weight and the microwave performance of the module. A specific technological process has been developed consisting in the fabrication of the devices on a dielectric membrane on air suspended in order to improve the insertion loss and the isolation. To prove the concept, building blocks have been already fabricated and measured (i.e micromachined transmission and filter featuring very low insertion loss, single pole double through circuits to address the appropriate path of the redundancy ring). We have to outline that MEMS technology have allowed a simplification of the architecture and a different system partitioning which gives more degree of freedom for the system designer. Furthermore, it has been conducted an exhaustive reliability study in order to identify the failure mechanisms. Again, from the results obtained, we have proposed an original topology for the SPDT circuit that takes into account the reliability behaviour of the MEMS devices and that allow to prevent most of the failure mechanisms reported so far (mainly related to the dielectric charging effect). Finally, the active device (millimetre wave low noise amplifier) will be reported on the MEMS based chip using

  13. Moving force identification based on redundant concatenated dictionary and weighted l1-norm regularization

    Science.gov (United States)

    Pan, Chu-Dong; Yu, Ling; Liu, Huan-Lin; Chen, Ze-Peng; Luo, Wen-Feng

    2018-01-01

    Moving force identification (MFI) is an important inverse problem in the field of bridge structural health monitoring (SHM). Reasonable signal structures of moving forces are rarely considered in the existing MFI methods. Interaction forces are complex because they contain both slowly-varying harmonic and impact signals due to bridge vibration and bumps on a bridge deck, respectively. Therefore, the interaction forces are usually hard to be expressed completely and sparsely by using a single basis function set. Based on the redundant concatenated dictionary and weighted l1-norm regularization method, a hybrid method is proposed for MFI in this study. The redundant dictionary consists of both trigonometric functions and rectangular functions used for matching the harmonic and impact signal features of unknown moving forces. The weighted l1-norm regularization method is introduced for formulation of MFI equation, so that the signal features of moving forces can be accurately extracted. The fast iterative shrinkage-thresholding algorithm (FISTA) is used for solving the MFI problem. The optimal regularization parameter is appropriately chosen by the Bayesian information criterion (BIC) method. In order to assess the accuracy and the feasibility of the proposed method, a simply-supported beam bridge subjected to a moving force is taken as an example for numerical simulations. Finally, a series of experimental studies on MFI of a steel beam are performed in laboratory. Both numerical and experimental results show that the proposed method can accurately identify the moving forces with a strong robustness, and it has a better performance than the Tikhonov regularization method. Some related issues are discussed as well.

  14. Sparse redundancy analysis of high-dimensional genetic and genomic data.

    Science.gov (United States)

    Csala, Attila; Voorbraak, Frans P J M; Zwinderman, Aeilko H; Hof, Michel H

    2017-10-15

    Recent technological developments have enabled the possibility of genetic and genomic integrated data analysis approaches, where multiple omics datasets from various biological levels are combined and used to describe (disease) phenotypic variations. The main goal is to explain and ultimately predict phenotypic variations by understanding their genetic basis and the interaction of the associated genetic factors. Therefore, understanding the underlying genetic mechanisms of phenotypic variations is an ever increasing research interest in biomedical sciences. In many situations, we have a set of variables that can be considered to be the outcome variables and a set that can be considered to be explanatory variables. Redundancy analysis (RDA) is an analytic method to deal with this type of directionality. Unfortunately, current implementations of RDA cannot deal optimally with the high dimensionality of omics data (p≫n). The existing theoretical framework, based on Ridge penalization, is suboptimal, since it includes all variables in the analysis. As a solution, we propose to use Elastic Net penalization in an iterative RDA framework to obtain a sparse solution. We proposed sparse redundancy analysis (sRDA) for high dimensional omics data analysis. We conducted simulation studies with our software implementation of sRDA to assess the reliability of sRDA. Both the analysis of simulated data, and the analysis of 485 512 methylation markers and 18,424 gene-expression values measured in a set of 55 patients with Marfan syndrome show that sRDA is able to deal with the usual high dimensionality of omics data. http://uva.csala.me/rda. a.csala@amc.uva.nl. Supplementary data are available at Bioinformatics online.

  15. Are the 10 meter and 6 minute walk tests redundant in patients with spinal cord injury?

    Directory of Open Access Journals (Sweden)

    Gail F Forrest

    Full Text Available OBJECTIVE: To evaluate the relationship and redundancy between gait speeds measured by the 10 Meter Walk Test (10MWT and 6 Minute Walk Test (6MWT after motor incomplete spinal cord injury (iSCI. To identify gait speed thresholds supporting functional ambulation as measured with the Spinal Cord Injury Functional Ambulation Inventory (SCI-FAI. DESIGN: Prospective observational cohort. SETTING: Seven outpatient rehabilitation centers from the Christopher and Dana Reeve Foundation NeuroRecovery Network (NRN. PARTICIPANTS: 249 NRN patients with American Spinal Injury Association Impairment Scale (AIS level C (n = 20, D (n = 179 and (n = 50 iSCI not AIS evaluated, from February 2008 through April 2011. INTERVENTIONS: Locomotor training using body weight support and walking on a treadmill, overground and home/community practice. MAIN OUTCOME MEASURE(S: 10MWT and 6MWT collected at enrollment, approximately every 20 sessions, and upon discharge. RESULTS: The 10MWT and 6MWT speeds were highly correlated and the 10MWT speeds were generally faster. However, the predicted 6MWT gait speed from the 10MWT, revealed increasing error with increased gait speed. Regression lines remained significantly different from lines of agreement, when the group was divided into fast (≥0.44 m/s and slow walkers (<0.44 m/s. Significant differences between 6MWT and 10MWT gait speeds were observed across SCI-FAI walking mobility categories (Wilcoxon sign rank test p<.001, and mean speed thresholds for limited community ambulation differed for each measure. The smallest real difference for the 6MWT and 10MWT, as well as the minimally clinically important difference (MCID values, were also distinct for the two tests. CONCLUSIONS: While the speeds were correlated between the 6MWT and 10MWT, redundancy in the tests using predictive modeling was not observed. Different speed thresholds and separate MCIDs were defined for community ambulation for each test.

  16. Fault tolerance in protein interaction networks: stable bipartite subgraphs and redundant pathways.

    Directory of Open Access Journals (Sweden)

    Arthur Brady

    Full Text Available As increasing amounts of high-throughput data for the yeast interactome become available, more system-wide properties are uncovered. One interesting question concerns the fault tolerance of protein interaction networks: whether there exist alternative pathways that can perform some required function if a gene essential to the main mechanism is defective, absent or suppressed. A signature pattern for redundant pathways is the BPM (between-pathway model motif, introduced by Kelley and Ideker. Past methods proposed to search the yeast interactome for BPM motifs have had several important limitations. First, they have been driven heuristically by local greedy searches, which can lead to the inclusion of extra genes that may not belong in the motif; second, they have been validated solely by functional coherence of the putative pathways using GO enrichment, making it difficult to evaluate putative BPMs in the absence of already known biological annotation. We introduce stable bipartite subgraphs, and show they form a clean and efficient way of generating meaningful BPMs which naturally discard extra genes included by local greedy methods. We show by GO enrichment measures that our BPM set outperforms previous work, covering more known complexes and functional pathways. Perhaps most importantly, since our BPMs are initially generated by examining the genetic-interaction network only, the location of edges in the protein-protein physical interaction network can then be used to statistically validate each candidate BPM, even with sparse GO annotation (or none at all. We uncover some interesting biological examples of previously unknown putative redundant pathways in such areas as vesicle-mediated transport and DNA repair.

  17. Redundancy of Supply in the International Nuclear Fuel Fabrication Market: Are Fabrication Services Assured?

    Energy Technology Data Exchange (ETDEWEB)

    Seward, Amy M.; Toomey, Christopher; Ford, Benjamin E.; Wood, Thomas W.; Perkins, Casey J.

    2011-11-14

    For several years, Pacific Northwest National Laboratory (PNNL) has been assessing the reliability of nuclear fuel supply in support of the U.S. Department of Energy/National Nuclear Security Administration. Three international low enriched uranium reserves, which are intended back up the existing and well-functioning nuclear fuel market, are currently moving toward implementation. These backup reserves are intended to provide countries credible assurance that of the uninterrupted supply of nuclear fuel to operate their nuclear power reactors in the event that their primary fuel supply is disrupted, whether for political or other reasons. The efficacy of these backup reserves, however, may be constrained without redundant fabrication services. This report presents the findings of a recent PNNL study that simulated outages of varying durations at specific nuclear fuel fabrication plants. The modeling specifically enabled prediction and visualization of the reactors affected and the degree of fuel delivery delay. The results thus provide insight on the extent of vulnerability to nuclear fuel supply disruption at the level of individual fabrication plants, reactors, and countries. The simulation studies demonstrate that, when a reasonable set of qualification criteria are applied, existing fabrication plants are technically qualified to provide backup fabrication services to the majority of the world's power reactors. The report concludes with an assessment of the redundancy of fuel supply in the nuclear fuel market, and a description of potential extra-market mechanisms to enhance the security of fuel supply in cases where it may be warranted. This report is an assessment of the ability of the existing market to respond to supply disruptions that occur for technical reasons. A forthcoming report will address political disruption scenarios.

  18. A Minimal Set of Glycolytic Genes Reveals Strong Redundancies in Saccharomyces cerevisiae Central Metabolism.

    Science.gov (United States)

    Solis-Escalante, Daniel; Kuijpers, Niels G A; Barrajon-Simancas, Nuria; van den Broek, Marcel; Pronk, Jack T; Daran, Jean-Marc; Daran-Lapujade, Pascale

    2015-08-01

    As a result of ancestral whole-genome and small-scale duplication events, the genomes of Saccharomyces cerevisiae and many eukaryotes still contain a substantial fraction of duplicated genes. In all investigated organisms, metabolic pathways, and more particularly glycolysis, are specifically enriched for functionally redundant paralogs. In ancestors of the Saccharomyces lineage, the duplication of glycolytic genes is purported to have played an important role leading to S. cerevisiae's current lifestyle favoring fermentative metabolism even in the presence of oxygen and characterized by a high glycolytic capacity. In modern S. cerevisiae strains, the 12 glycolytic reactions leading to the biochemical conversion from glucose to ethanol are encoded by 27 paralogs. In order to experimentally explore the physiological role of this genetic redundancy, a yeast strain with a minimal set of 14 paralogs was constructed (the "minimal glycolysis" [MG] strain). Remarkably, a combination of a quantitative systems approach and semiquantitative analysis in a wide array of growth environments revealed the absence of a phenotypic response to the cumulative deletion of 13 glycolytic paralogs. This observation indicates that duplication of glycolytic genes is not a prerequisite for achieving the high glycolytic fluxes and fermentative capacities that are characteristic of S. cerevisiae and essential for many of its industrial applications and argues against gene dosage effects as a means of fixing minor glycolytic paralogs in the yeast genome. The MG strain was carefully designed and constructed to provide a robust prototrophic platform for quantitative studies and has been made available to the scientific community. Copyright © 2015, Solis-Escalante et al.

  19. Collision-free inverse kinematics of the redundant seven link manipulator used in a cucumber harvesting robot

    NARCIS (Netherlands)

    Henten, van E.J.; Schenk, E.J.J.; Willigenburg, van L.G.; Meuleman, J.; Barreiro, P.

    2010-01-01

    The paper presents results of research on an inverse kinematics algorithm that has been used in a functional model of a cucumber-harvesting robot consisting of a redundant P6R manipulator. Within a first generic approach, the inverse kinematics problem was reformulated as a non-linear programming

  20. The Effects of Intersensory Redundancy on Attention and Memory: Infants' Long-Term Memory for Orientation in Audiovisual Events

    Science.gov (United States)

    Flom, Ross; Bahrick, Lorraine E.

    2010-01-01

    This research examined the effects of bimodal audiovisual and unimodal visual stimulation on infants' memory for the visual orientation of a moving toy hammer following a 5-min, 2-week, or 1-month retention interval. According to the intersensory redundancy hypothesis (L. E. Bahrick & R. Lickliter, 2000; L. E. Bahrick, R. Lickliter, & R. Flom,…

  1. Mathematical model of process of redundant measurements with uninterrupted influence of measurand on sensing element of sensor

    Directory of Open Access Journals (Sweden)

    Redko V. V.

    2011-12-01

    Full Text Available The paper discusses improvement of accuracy of measurands measurements with the use of measuring channel with nonlinear calibration curve. There is proposed a mathematical model, which describes process of redundant measurements for measuring channel when it’s measurement function is a polynomial of third power.

  2. Assessing natural resource use by forest-reliant communities in Madagascar using functional diversity and functional redundancy metrics.

    Directory of Open Access Journals (Sweden)

    Kerry A Brown

    Full Text Available Biodiversity plays an integral role in the livelihoods of subsistence-based forest-dwelling communities and as a consequence it is increasingly important to develop quantitative approaches that capture not only changes in taxonomic diversity, but also variation in natural resources and provisioning services. We apply a functional diversity metric originally developed for addressing questions in community ecology to assess utilitarian diversity of 56 forest plots in Madagascar. The use categories for utilitarian plants were determined using expert knowledge and household questionnaires. We used a null model approach to examine the utilitarian (functional diversity and utilitarian redundancy present within ecological communities. Additionally, variables that might influence fluctuations in utilitarian diversity and redundancy--specifically number of felled trees, number of trails, basal area, canopy height, elevation, distance from village--were analyzed using Generalized Linear Models (GLMs. Eighteen of the 56 plots showed utilitarian diversity values significantly higher than expected. This result indicates that these habitats exhibited a low degree of utilitarian redundancy and were therefore comprised of plants with relatively distinct utilitarian properties. One implication of this finding is that minor losses in species richness may result in reductions in utilitarian diversity and redundancy, which may limit local residents' ability to switch between alternative choices. The GLM analysis showed that the most predictive model included basal area, canopy height and distance from village, which suggests that variation in utilitarian redundancy may be a result of local residents harvesting resources from the protected area. Our approach permits an assessment of the diversity of provisioning services available to local communities, offering unique insights that would not be possible using traditional taxonomic diversity measures. These analyses

  3. Assessing natural resource use by forest-reliant communities in Madagascar using functional diversity and functional redundancy metrics.

    Science.gov (United States)

    Brown, Kerry A; Flynn, Dan F B; Abram, Nicola K; Ingram, J Carter; Johnson, Steig E; Wright, Patricia

    2011-01-01

    Biodiversity plays an integral role in the livelihoods of subsistence-based forest-dwelling communities and as a consequence it is increasingly important to develop quantitative approaches that capture not only changes in taxonomic diversity, but also variation in natural resources and provisioning services. We apply a functional diversity metric originally developed for addressing questions in community ecology to assess utilitarian diversity of 56 forest plots in Madagascar. The use categories for utilitarian plants were determined using expert knowledge and household questionnaires. We used a null model approach to examine the utilitarian (functional) diversity and utilitarian redundancy present within ecological communities. Additionally, variables that might influence fluctuations in utilitarian diversity and redundancy--specifically number of felled trees, number of trails, basal area, canopy height, elevation, distance from village--were analyzed using Generalized Linear Models (GLMs). Eighteen of the 56 plots showed utilitarian diversity values significantly higher than expected. This result indicates that these habitats exhibited a low degree of utilitarian redundancy and were therefore comprised of plants with relatively distinct utilitarian properties. One implication of this finding is that minor losses in species richness may result in reductions in utilitarian diversity and redundancy, which may limit local residents' ability to switch between alternative choices. The GLM analysis showed that the most predictive model included basal area, canopy height and distance from village, which suggests that variation in utilitarian redundancy may be a result of local residents harvesting resources from the protected area. Our approach permits an assessment of the diversity of provisioning services available to local communities, offering unique insights that would not be possible using traditional taxonomic diversity measures. These analyses introduce another

  4. Identification of Poxvirus Genome Uncoating and DNA Replication Factors with Mutually Redundant Roles.

    Science.gov (United States)

    Liu, Baoming; Panda, Debasis; Mendez-Rios, Jorge D; Ganesan, Sundar; Wyatt, Linda S; Moss, Bernard

    2018-01-17

    Genome uncoating is essential for replication of most viruses. For poxviruses, the process is divided into two stages: removal of the envelope allowing early gene expression, and breaching of the core wall allowing DNA release, replication and late gene expression. Subsequent studies showed that the host proteasome and the viral D5 protein, which has an essential role in DNA replication, are required for vaccinia virus (VACV) genome uncoating. In a search for additional VACV uncoating proteins, we noted a report that described a defect in DNA replication and late expression when the gene encoding a 68 kDa ankyrin-repeat/F box protein (68k-ank), associated with the cellular SCF ubiquitin ligase complex, was deleted from the attenuated modified vaccinia virus Ankara (MVA). Here we showed that the formation of DNA pre-replication sites and degradation of viral cores were severely diminished indicating that the 68k-ank deletion mutant had a defect in genome uncoating as well as an additional independent defect in DNA synthesis. Deletion of the 68k-ank homolog of VACV strain WR, however, was without effect suggesting the existence of compensating genes. By inserting VACV genes into a MVA 68k-ank deletion mutant, we discovered that M2, a member of the Poxvirus Immune Evasion (PIE) domain superfamily and a regulator of NF-κB, and that C5, a member of the BTB/kelch superfamily associated with cullin-3-based ligase complexes, independently rescued the 68k-ank deletion phenotype. Thus, poxvirus uncoating and DNA replication are intertwined processes involving at least three viral proteins with mutually redundant functions in addition to D5.IMPORTANCE Poxviruses comprise a family of large DNA viruses that infect vertebrates and invertebrates and cause diseases of medical and zoological importance. Poxviruses, unlike most other DNA viruses, replicate in the cytoplasm and their large genomes usually encode 200 or more proteins with diverse functions. About 90 genes may be

  5. Novel iterative reconstruction method with optimal dose usage for partially redundant CT-acquisition.

    Science.gov (United States)

    Bruder, H; Raupach, R; Sunnegardh, J; Allmendinger, T; Klotz, E; Stierstorfer, K; Flohr, T

    2015-11-07

    In CT imaging, a variety of applications exist which are strongly SNR limited. However, in some cases redundant data of the same body region provide additional quanta. Examples in dual energy CT, the spatial resolution has to be compromised to provide good SNR for material decomposition. However, the respective spectral dataset of the same body region provides additional quanta which might be utilized to improve SNR of each spectral component. Perfusion CT is a high dose application, and dose reduction is highly desirable. However, a meaningful evaluation of perfusion parameters might be impaired by noisy time frames. On the other hand, the SNR of the average of all time frames is extremely high.In redundant CT acquisitions, multiple image datasets can be reconstructed and averaged to composite image data. These composite image data, however, might be compromised with respect to contrast resolution and/or spatial resolution and/or temporal resolution. These observations bring us to the idea of transferring high SNR of composite image data to low SNR 'source' image data, while maintaining their resolution.It has been shown that the noise characteristics of CT image data can be improved by iterative reconstruction (Popescu et al 2012 Book of Abstracts, 2nd CT Meeting (Salt Lake City, UT) p 148). In case of data dependent Gaussian noise it can be modelled with image-based iterative reconstruction at least in an approximate manner (Bruder et al 2011 Proc. SPIE 7961 79610J). We present a generalized update equation in image space, consisting of a linear combination of the previous update, a correction term which is constrained by the source image data, and a regularization prior, which is initialized by the composite image data. This iterative reconstruction approach we call bimodal reconstruction (BMR). Based on simulation data it is shown that BMR can improve low contrast detectability, substantially reduces the noise power and has the potential to recover spatial

  6. Grassroots (Economic Activism in Times of Crisis: Mapping the Redundancy of Collective Actions

    Directory of Open Access Journals (Sweden)

    Giacomo D’Alisa

    2015-07-01

    mutual solidarity between individuals and more sustainable connections with the environment. This special issue is a reflection, among the many that have being proposed of late, on some of these self-organized collective actions that have pass through and/or emerged from the aftermath of the crisis. It is the result of an attempt to cross various disciplinary fields, in order to explore the redundancy of their respective explanations as to why and how some grassroots activities last and succeed, and turn this redundancy into the powerhouse for relaunching more robust and less aleatory initiatives.

  7. A non-redundant role for Drosophila Mkk4 and hemipterous/Mkk7 in TAK1-mediated activation of JNK.

    Directory of Open Access Journals (Sweden)

    Peter Geuking

    Full Text Available BACKGROUND: The JNK pathway is a mitogen-activated protein (MAP kinase pathway involved in the regulation of numerous physiological processes during development and in response to environmental stress. JNK activity is controlled by two MAPK kinases (MAPKK, Mkk4 and Mkk7. Mkk7 plays a prominent role upon Tumor Necrosis Factor (TNF stimulation. Eiger, the unique TNF-superfamily ligand in Drosophila, potently activates JNK signaling through the activation of the MAPKKK Tak1. METHODOLOGY/PRINCIPAL FINDINGS: In a dominant suppressor screen for new components of the Eiger/JNK-pathway in Drosophila, we have identified an allelic series of the Mkk4 gene. Our genetic and biochemical results demonstrate that Mkk4 is dispensable for normal development and host resistance to systemic bacterial infection but plays a non-redundant role as a MAPKK acting in parallel to Hemipterous/Mkk7 in dTAK1-mediated JNK activation upon Eiger and Imd pathway activation. CONCLUSIONS/SIGNIFICANCE: In contrast to mammals, it seems that in Drosophila both MAPKKs, Hep/Mkk7 and Mkk4, are required to induce JNK upon TNF or pro-inflammatory stimulation.

  8. When redundant on-screen text in multimedia technical instruction can interfere with learning.

    Science.gov (United States)

    Kalyuga, Slava; Chandler, Paul; Sweller, John

    2004-01-01

    It is frequently assumed that presenting the same material in written and spoken form benefits learning and understanding. The present work provides a theoretical justification based on cognitive load theory, and empirical evidence based on controlled experiments, that this assumption can be incorrect. From a theoretical perspective, it is suggested that if learners are required to coordinate and simultaneously process redundant material such as written and spoken text, an excessive working memory load is generated. Three experiments involving a group of 25 technical apprentices compared the effects of simultaneously presenting the same written and auditory textual information as opposed to either temporally separating the two modes or eliminating one of the modes. The first two experiments demonstrated that nonconcurrent presentation of auditory and visual explanations of a diagram proved superior, in terms of ratings of mental load and test scores, to a concurrent presentation of the same explanations when instruction time was constrained. The 3rd experiment demonstrated that a concurrent presentation of identical auditory and visual technical text (without the presence of diagrams) was significantly less efficient in comparison with an auditory-only text. Actual or potential applications of this research include the design and evaluation of multimedia instructional systems and audiovisual displays.

  9. Simplifying the EFT of Inflation: generalized disformal transformations and redundant couplings

    Science.gov (United States)

    Bordin, Lorenzo; Cabass, Giovanni; Creminelli, Paolo; Vernizzi, Filippo

    2017-09-01

    We study generalized disformal transformations, including derivatives of the metric, in the context of the Effective Field Theory of Inflation. All these transformations do not change the late-time cosmological observables but change the coefficients of the operators in the action: some couplings are effectively redundant. At leading order in derivatives and up to cubic order in perturbations, one has 6 free functions that can be used to set to zero 6 of the 17 operators at this order. This is used to show that the tensor three-point function cannot be modified at leading order in derivatives, while the scalar-tensor-tensor correlator can only be modified by changing the scalar dynamics. At higher order in derivatives there are transformations that do not affect the Einstein-Hilbert action: one can find 6 additional transformations that can be used to simplify the inflaton action, at least when the dynamics is dominated by the lowest derivative terms. We also identify the leading higher-derivative corrections to the tensor power spectrum and bispectrum.

  10. Biological Redundancy of Endogenous GPCR Ligands in the Gut and the Potential for Endogenous Functional Selectivity

    Directory of Open Access Journals (Sweden)

    Georgina eThompson

    2014-11-01

    Full Text Available This review focuses on the existence and function of multiple endogenous agonists of the somatostatin and opioid receptors with an emphasis on their expression in the gastrointestinal tract (GIT. These agonists generally arise from the proteolytic cleavage of prepropeptides during peptide maturation or from degradation of peptides by extracellular or intracellular endopeptidases. In other examples, endogenous peptide agonists for the same G protein-coupled receptors can be products of distinct genes but contain high sequence homology. This apparent biological redundancy has recently been challenged by the realization that different ligands may engender distinct receptor conformations linked to different intracellular signaling profiles and, as such the existence of distinct ligands may underlie mechanisms to finely tune physiological responses. We propose that further characterization of signaling pathways activated by these endogenous ligands will provide invaluable insight into the mechanisms governing biased agonism. Moreover, these ligands may prove useful in the design of novel therapeutic tools to target distinct signaling pathways, thereby favoring desirable effects and limiting detrimental on-target effects. Finally we will discuss the limitations of this area of research and we will highlight the difficulties that need to be addressed when examining endogenous bias in tissues and in animals.

  11. Using data redundancy gained by patch overlaps to reduce truncation artifacts in magnetic particle imaging

    Science.gov (United States)

    Ahlborg, M.; Kaethner, C.; Knopp, T.; Szwargulski, P.; Buzug, T. M.

    2016-06-01

    The imaging technology magnetic particle imaging allows the detection of magnetic material, in particular superparamagnetic nanoparticles, by remagnetization of the material via magnetic fields. The application is aimed at medical imaging where the particles are applied as tracer directly into the blood stream. Medical safety considerations such as peripheral nerve stimulation limit the maximal amplitude of the magnetic fields and in turn the field of view size. To handle this constraint the concept of patches was introduced, which allows a shift of a field of view to different positions in order to enlarge the imaging area. If this is done statically an overlap of patches can be used to reduce truncation artifacts occurring at the adjacent edges. In this contribution, a differentiation of two different kinds of patch overlaps, i.e. a trajectory and a system matrix overlap, is made. Further, different concepts to combine the resulting redundant information are investigated with respect to the reduction of truncation artifacts. The methods are analyzed in detail in a simulation study and validated on experimental data.

  12. Relations between redundancy patterns of the Shannon code and wave diffraction patterns of partially disordered media

    CERN Document Server

    Merhav, Neri

    2011-01-01

    The average redundancy of the Shannon code, $R_n$, as a function of the block length $n$, is known to exhibit two very different types of behavior, depending on the rationality or irrationality of certain parameters of the source: It either converges to 1/2 as $n$ grows without bound, or it may have a non-vanishing, oscillatory, (quasi-) periodic pattern around the value 1/2 for all large $n$. In this paper, we make an attempt to shed some insight into this erratic behavior of $R_n$, by drawing an analogy with the realm of physics of wave propagation, in particular, the elementary theory of scattering and diffraction. It turns out that there are two types of behavior of wave diffraction patterns formed by crystals, which are correspondingly analogous to the two types of patterns of $R_n$. When the crystal is perfect, the diffraction intensity spectrum exhibits very sharp peaks, a.k.a. Bragg peaks, at wavelengths of full constructive interference. These wavelengths correspond to the frequencies of the harmonic...

  13. Cognitive Load and Learner Expertise: Split-Attention and Redundancy Effects in Reading with Explanatory Notes

    Science.gov (United States)

    Yeung; Jin; Sweller

    1998-01-01

    Five experiments were conducted to examine the effects of cognitive load management using explanatory notes in reading passages for readers with different levels of expertise. Experiment 1 found that explanatory notes improved 5th-grade, first-language learners' comprehension (high-level processing) but not vocabulary learning (low-level processing). Experiment 2 found that vocabulary definitions integrated within a passage (integrated format) enhanced 5th graders' comprehension compared to a separate vocabulary list (separated format) but reduced vocabulary learning. Experiment 3, using adult readers, found that an integrated format reduced comprehension but enhanced vocabulary learning. Experiment 4 used low-ability 8th-grade learners of English as a second language (ESL) and found an effect similar to the 5th graders in Experiment 2. Experiment 5 showed that the effect for high-ability ESL learners was similar to the adults in Experiment 3. We argue that the efficiency of instruction depends on the extent to which it imposes an extraneous cognitive load. The same presentation format may facilitate performance or interfere with performance either through split-attention or redundancy effects, depending on learners' expertise. Copyright 1998 Academic Press.

  14. Cauda equina redundant nerve roots are associated to the degree of spinal stenosis and to spondylolisthesis

    Directory of Open Access Journals (Sweden)

    Leonor Garbin Savarese

    2014-10-01

    Full Text Available To evaluate the association of redundant nerve roots of cauda equina (RNRCE with the degree of lumbar spinal stenosis (LSS and with spondylolisthesis. Method After Institutional Board approval, 171 consecutive patients were retrospectively enrolled, 105 LSS patients and 66 patients without stenosis. The dural sac cross-sectional area (CSA was measured on T2w axial MRI at the level of L2-3, L3-4 and L4-5 intervertebral discs. Two blinded radiologists classified cases as exhibiting or not RNRCE in MRI. Intra- and inter-observer reproducibility was assessed. Results RNRCE were associated with LSS. RRNCE was more frequent when maximum stenosis<55 mm2. Substantial intra- observer agreement and moderate inter-observer agreement were obtained in the classification of RNRCE. Spondylolisthesis was identified in 27 patients and represented increased risk for RRNCE. Conclusion LSS is a risk factor for RNRCE, especially for dural sac CSA<55 mm2. LSS and spondylolisthesis are independent risk factors for RNRCE.

  15. ADP-dependent phosphofructokinases from the archaeal order Methanosarcinales display redundant glucokinase activity.

    Science.gov (United States)

    Zamora, Ricardo A; Gonzalez-Órdenes, Felipe; Castro-Fernández, Victor; Guixé, Victoria

    2017-11-01

    The genome of Methanosarcinales organisms presents both ADP-dependent glucokinase and phosphofructokinase genes. However, Methanococcoides burtonii has a truncate glucokinase gene with a large deletion at the C-terminal, where the catalytic GXGD motif is located. Characterization of its phosphofructokinase annotated protein shows that is a bifunctional enzyme able to supply the absence of the glucokinase activity. Moreover, kinetic analyses of the phosphofructokinase annotated enzyme from, Methanohalobium evestigatum demonstrated that this enzyme is also bifunctional. The high conservation of the active site residues of all the enzymes from the order Methanosarcinales suggest that they should be bifunctional, as was previously reported for the ADP-dependent kinases from Methanococcales, highlighting the redundancy of the glucokinase activity in this archaeal group. The presence of active glycolytic enzymes would be important when glycogen storage of these organisms needs to be degraded to be used as energy source. Kinetic and structural information allows us to establish a substrate specificity signature that identifies specific GK or PFK, and bifunctional enzymes in this family. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. A Network of Local and Redundant Gene Regulation Governs Arabidopsis Seed Maturation

    Science.gov (United States)

    To, Alexandra; Valon, Christiane; Savino, Gil; Guilleminot, Jocelyne; Devic, Martine; Giraudat, Jérôme; Parcy, François

    2006-01-01

    In Arabidopsis thaliana, four major regulators (ABSCISIC ACID INSENSITIVE3 [ABI3], FUSCA3 [FUS3], LEAFY COTYLEDON1 [LEC1], and LEC2) control most aspects of seed maturation, such as accumulation of storage compounds, cotyledon identity, acquisition of desiccation tolerance, and dormancy. The molecular basis for complex genetic interactions among these regulators is poorly understood. By analyzing ABI3 and FUS3 expression in various single, double, and triple maturation mutants, we have identified multiple regulatory links among all four genes. We found that one of the major roles of LEC2 was to upregulate FUS3 and ABI3. The lec2 mutation is responsible for a dramatic decrease in ABI3 and FUS3 expression, and most lec2 phenotypes can be rescued by ABI3 or FUS3 constitutive expression. In addition, ABI3 and FUS3 positively regulate themselves and each other, thereby forming feedback loops essential for their sustained and uniform expression in the embryo. Finally, LEC1 also positively regulates ABI3 and FUS3 in the cotyledons. Most of the genetic controls discovered were found to be local and redundant, explaining why they had previously been overlooked. This works establishes a genetic framework for seed maturation, organizing the key regulators of this process into a hierarchical network. In addition, it offers a molecular explanation for the puzzling variable features of lec2 mutant embryos. PMID:16731585

  17. National treasure or a redundant relic: the roles of the vernacular in Czech art

    Directory of Open Access Journals (Sweden)

    Filipová, Marta

    2013-02-01

    Full Text Available The article examines the reception of folk art in the visual culture of Bohemia and Czechoslovakia and focuses on the shift in the meaning of folk art in the period of early twentieth-century modernism. It examines closely the main attitudes and approaches to folk art in examples drawn from painting, sculpture and architecture as well as art theory in the Czech-speaking regions from the end of the nineteenth century until the early 1930s. This politically important period that saw the transformation of the Habsburg monarchy into new independent states, including Czechoslovakia, was also marked by the establishment of modernism in Central Europe. Many Czech artists were turning to more cosmopolitan ideas, while simultaneously they retained some of the ideas and ideals from the nineteenth century national revival. These shifts were reflected in the various roles folk art was given, ranging from its association with a nostalgic return to pre-industrial society, to an ideological tool of national revival, and to a redundant relic of the past. Folk art, therefore, is understood as a complex phenomenon, which disrupts the reading of modernism in Central Europe as a straightforward embrace of cosmopolitan ideas in the visual arts and art theory and that challenges the historical opposition between folk art and high art. Simultaneously, its central role in the formation of Central European modernism is emphasized as crucial to our understanding of Central European art in this period.

  18. Concept redundancy and contamination in employee commitment research: Current problems and future directions

    Directory of Open Access Journals (Sweden)

    Gert Roodt

    2004-10-01

    Full Text Available It is generally accepted that employee commitment has a significant impact on organisational performance. The primary goal of this article is to indicate that the ‘commitment/involvement’ concept did not evolve in an evolutionary and progressive fashion. Several problems in the development course of mainly three streams of research literature are indicated. Arguments are presented for indicating causes of concept contamination and even redundancy. In order to bridge these problems, a motivational approach as an integrating mechanism on a metatheoretical level is presented as a solution. The outcomes thereof should lead to better order on a theoretical level and to the parsimonious use of commitment concepts. Opsomming Dit word algemeen aanvaar dat werknemertoewyding ’n duidelike impak op organisasieprestasie het. Die primêre doel van hierdie artikel is om aan te dui dat die ontwikkeling van die ‘betrokkenheid/toewydings-’ konsep nie evolusionêr en progressief verloop het nie. Verskeie probleme in die ontwikkelingsgang van hoofsaaklik drie strome navorsingsliteratuur word aangedui. Argumente word aangevoer wat op oorsake van konsepkontaminasie en selfs -oorbodigheid dui. Ten einde hierdie probleme te oorkom, word ’n motiveringsbenadering as integrerende meganisme op ’n meta-teoretiese vlak as oplossing voorgehou. Die uitkoms daarvan behoort tot beter orde op teoretiese vlak en tot die spaarsamige gebruik van toewydingskonsepte te lei.

  19. Functional Redundancy of the B9 Proteins and Nephrocystins in Caenorhabditis elegans Ciliogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Corey [University of Alabama, Birmingham; Winkelbauer, Marlene [Yale University; Schafer, Jenny [Vanderbilt University; Michaud III, Edward J [ORNL; Yoder, Bradley [University of Alabama, Birmingham

    2008-01-01

    Meckel-Gruber syndrome (MKS), nephronophthisis (NPHP), and Joubert syndrome (JBTS) are a group of heterogeneous cystic kidney disorders with partially overlapping loci. Many of the proteins associated with these diseases interact and localize to cilia and/or basal bodies. One of these proteins is MKS1, which is disrupted in some MKS patients and contains a B9 motif of unknown function that is found in two other mammalian proteins, B9D2 and B9D1. Caenorhabditis elegans also has three B9 proteins: XBX-7 (MKS1), TZA-1 (B9D2), and TZA-2 (B9D1). Herein, we report that the C. elegans B9 proteins form a complex that localizes to the base of cilia. Mutations in the B9 genes do not overtly affect cilia formation unless they are in combination with a mutation in nph-1 or nph-4, the homologues of human genes (NPHP1 and NPHP4, respectively) that are mutated in some NPHP patients. Our data indicate that the B9 proteins function redundantly with the nephrocystins to regulate the formation and/or maintenance of cilia and dendrites in the amphid and phasmid ciliated sensory neurons. Together, these data suggest that the human homologues of the novel B9 genes B9D2 and B9D1 will be strong candidate loci for pathologies in human MKS, NPHP, and JBTS.

  20. An Extended Passive Motion Paradigm for Human-Like Posture and Movement Planning in Redundant Manipulators

    Directory of Open Access Journals (Sweden)

    Paolo Tommasino

    2017-11-01

    Full Text Available A major challenge in robotics and computational neuroscience is relative to the posture/movement problem in presence of kinematic redundancy. We recently addressed this issue using a principled approach which, in conjunction with nonlinear inverse optimization, allowed capturing postural strategies such as Donders' law. In this work, after presenting this general model specifying it as an extension of the Passive Motion Paradigm, we show how, once fitted to capture experimental postural strategies, the model is actually able to also predict movements. More specifically, the passive motion paradigm embeds two main intrinsic components: joint damping and joint stiffness. In previous work we showed that joint stiffness is responsible for static postures and, in this sense, its parameters are regressed to fit to experimental postural strategies. Here, we show how joint damping, in particular its anisotropy, directly affects task-space movements. Rather than using damping parameters to fit a posteriori task-space motions, we make the a priori hypothesis that damping is proportional to stiffness. This remarkably allows a postural-fitted model to also capture dynamic performance such as curvature and hysteresis of task-space trajectories during wrist pointing tasks, confirming and extending previous findings in literature.

  1. Coresets vs clustering: comparison of methods for redundancy reduction in very large white matter fiber sets

    Science.gov (United States)

    Alexandroni, Guy; Zimmerman Moreno, Gali; Sochen, Nir; Greenspan, Hayit

    2016-03-01

    Recent advances in Diffusion Weighted Magnetic Resonance Imaging (DW-MRI) of white matter in conjunction with improved tractography produce impressive reconstructions of White Matter (WM) pathways. These pathways (fiber sets) often contain hundreds of thousands of fibers, or more. In order to make fiber based analysis more practical, the fiber set needs to be preprocessed to eliminate redundancies and to keep only essential representative fibers. In this paper we demonstrate and compare two distinctive frameworks for selecting this reduced set of fibers. The first framework entails pre-clustering the fibers using k-means, followed by Hierarchical Clustering and replacing each cluster with one representative. For the second clustering stage seven distance metrics were evaluated. The second framework is based on an efficient geometric approximation paradigm named coresets. Coresets present a new approach to optimization and have huge success especially in tasks requiring large computation time and/or memory. We propose a modified version of the coresets algorithm, Density Coreset. It is used for extracting the main fibers from dense datasets, leaving a small set that represents the main structures and connectivity of the brain. A novel approach, based on a 3D indicator structure, is used for comparing the frameworks. This comparison was applied to High Angular Resolution Diffusion Imaging (HARDI) scans of 4 healthy individuals. We show that among the clustering based methods, that cosine distance gives the best performance. In comparing the clustering schemes with coresets, Density Coreset method achieves the best performance.

  2. Redundancy in putrescine catabolism in solvent tolerant Pseudomonas putida S12.

    Science.gov (United States)

    Bandounas, Luaine; Ballerstedt, Hendrik; de Winde, Johannes H; Ruijssenaars, Harald J

    2011-06-10

    Pseudomonas putida S12 is a promising platform organism for the biological production of substituted aromatic compounds due to its extreme tolerance towards toxic chemicals. Solvent or aromatic stress tolerance may be due to membrane modifications and efflux pumps; however in general, polyamines have also been implicated in stressed cells. Previous transcriptomics results of P. putida strains producing an aromatic compound, or being exposed to the solvent toluene, indicated differentially expressed genes involved in polyamine transport and metabolism. Therefore, the metabolism of the polyamine, putrescine was investigated in P. putida S12, as no putrescine degradation pathways have been described for this strain. Via transcriptome analysis various, often redundant, putrescine-induced genes were identified as being potentially involved in putrescine catabolism via oxidative deamination and transamination. A series of knockout mutants were constructed in which up to six of these genes were sequentially deleted, and although putrescine degradation was affected in some of these mutants, complete elimination of putrescine degradation in P. putida S12 was not achieved. Evidence was found for the presence of an alternative pathway for putrescine degradation involving γ-glutamylation. The occurrence of multiple putrescine degradation routes in the solvent-tolerant P. putida S12 is indicative of the importance of controlling polyamine homeostasis, as well as of the high metabolic flexibility exhibited by this microorganism. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Non-redundant patent sequence databases with value-added annotations at two levels

    Science.gov (United States)

    Li, Weizhong; McWilliam, Hamish; de la Torre, Ana Richart; Grodowski, Adam; Benediktovich, Irina; Goujon, Mickael; Nauche, Stephane; Lopez, Rodrigo

    2010-01-01

    The European Bioinformatics Institute (EMBL-EBI) provides public access to patent data, including abstracts, chemical compounds and sequences. Sequences can appear multiple times due to the filing of the same invention with multiple patent offices, or the use of the same sequence by different inventors in different contexts. Information relating to the source invention may be incomplete, and biological information available in patent documents elsewhere may not be reflected in the annotation of the sequence. Search and analysis of these data have become increasingly challenging for both the scientific and intellectual-property communities. Here, we report a collection of non-redundant patent sequence databases, which cover the EMBL-Bank nucleotides patent class and the patent protein databases and contain value-added annotations from patent documents. The databases were created at two levels by the use of sequence MD5 checksums. Sequences within a level-1 cluster are 100% identical over their whole length. Level-2 clusters were defined by sub-grouping level-1 clusters based on patent family information. Value-added annotations, such as publication number corrections, earliest publication dates and feature collations, significantly enhance the quality of the data, allowing for better tracking and cross-referencing. The databases are available format: http://www.ebi.ac.uk/patentdata/nr/. PMID:19884134

  4. Recent Advances in Registration, Integration and Fusion of Remotely Sensed Data: Redundant Representations and Frames

    Science.gov (United States)

    Czaja, Wojciech; Le Moigne-Stewart, Jacqueline

    2014-01-01

    In recent years, sophisticated mathematical techniques have been successfully applied to the field of remote sensing to produce significant advances in applications such as registration, integration and fusion of remotely sensed data. Registration, integration and fusion of multiple source imagery are the most important issues when dealing with Earth Science remote sensing data where information from multiple sensors, exhibiting various resolutions, must be integrated. Issues ranging from different sensor geometries, different spectral responses, differing illumination conditions, different seasons, and various amounts of noise need to be dealt with when designing an image registration, integration or fusion method. This tutorial will first define the problems and challenges associated with these applications and then will review some mathematical techniques that have been successfully utilized to solve them. In particular, we will cover topics on geometric multiscale representations, redundant representations and fusion frames, graph operators, diffusion wavelets, as well as spatial-spectral and operator-based data fusion. All the algorithms will be illustrated using remotely sensed data, with an emphasis on current and operational instruments.

  5. Performance of hybrid-ARQ with incremental redundancy over relay channels

    KAUST Repository

    Chelli, Ali

    2012-12-01

    In this paper, we consider a relay network consisting of a source, a relay, and a destination. The source transmits a message to the destination using hybrid automatic repeat request (HARQ) with incremental redundancy (IR). The relay overhears the transmitted messages over the different HARQ rounds and tries to decode the data packet. In case of successful decoding at the relay, both the relay and the source cooperate to transmit the message to the destination. A maximum number M of HARQ rounds is considered. The channel realizations are independent for different HARQ rounds. We assume Rayleigh fading channels for the links source-relay, source-destination, and relay-destination. We investigate the performance of HARQ-IR over relay channel from an information theoretic perspective. Analytical expressions are derived for the information outage probability, the average number of transmissions, and the average transmission rate. We illustrate through our investigation the benefit of relaying. We also show the impact of the target outage probability and the maximum number M of HARQ rounds on the outage probability, the average number of transmissions, and the average transmission rate. © 2012 IEEE.

  6. Redundant air conditioners for railway train waggons; Redundante Klimaanlagen fuer Reisezugwagen

    Energy Technology Data Exchange (ETDEWEB)

    Ebinger, I. [NOSKE-KAESER GmbH, Hamburg (Germany)

    2003-07-01

    The contribution discusses the advantages and drawbacks of redundant air conditioners, i.e. system requirements, operation and servicing. Two different variants for different applications are presented along with the necessary duct system. The example of part load operation in the cooling mode - which is particularly critical - is used to illustrate a successfully applied control strategy on the basis of process data acquired in normal operation. [German] Klimaanlagen gehoeren in Reisezugwagen des Fernverkehrs inzwischen zur Standardausruestung und werden auch in Nahverkehrsfahrzeugen immer haeufiger eingesetzt. Aufgrund unterschiedlicher Fahrzeugkonstruktionen kommen sowohl Kompakt- als auch Splitanlagen zum Einsatz. Unter bestimmten Umstaenden, etwa infolge eines oertlich sehr begrenzten Raumangebotes oder besonderer Anforderungen an die Funktionssicherheit, werden zwei Klimaanlagen in einem Fahrzeug eingesetzt; redundante Klimaanlagen also. Ausgehend von den Ursachen fuer den Einsatz redundanter Klimaanlagen werden die Vor- und Nachteile derartiger Klimaanlagensysteme im Hinblick auf den Geraeteaufwand, den Betrieb und die Unterhaltung aufgezeigt. Es werden zwei verschiedene Anforderungsvarianten der Klimaanlagen und die zugehoerigen Kanalsysteme vorgestellt. Am Beispiel des besonders kritischen Teillastbetriebes im Kuehlmodus wird anhand von im regulaeren Einsatz aufgezeichneten Prozessdaten eine mit Erfolg eingesetzte Regelstrategie erlaeutert. (orig.)

  7. Hybrid task priority-based motion control of a redundant free-floating space robot

    Directory of Open Access Journals (Sweden)

    Cheng ZHOU

    2017-12-01

    Full Text Available This paper presents a novel hybrid task priority-based motion planning algorithm of a space robot. The satellite attitude control task is defined as the primary task, while the least-squares-based non-strict task priority solution of the end-effector plus the multi-constraint task is viewed as the secondary task. Furthermore, a null-space task compensation strategy in the joint space is proposed to derive the combination of non-strict and strict task-priority motion planning, and this novel combination is termed hybrid task priority control. Thus, the secondary task is implemented in the primary task’s null-space. Besides, the transition of the state of multiple constraints between activeness and inactiveness will only influence the end-effector task without any effect on the primary task. A set of numerical experiments made in a real-time simulation system under Linux/RTAI shows the validity and feasibility of the proposed methodology. Keywords: Base attitude control, Hybrid task-priority, Motion planning, Multiple constraints, Redundant space robot

  8. Fault-tolerant system considerations for a redundant strapdown inertial measurement unit

    Science.gov (United States)

    Motyka, P.; Ornedo, R.; Mangoubi, R.

    1984-01-01

    The development and evaluation of a fault-tolerant system for the Redundant Strapdown Inertial Measurement Unit (RSDIMU) being developed and evaluated by the NASA Langley Research Center was continued. The RSDIMU consists of four two-degree-of-freedom gyros and accelerometers mounted on the faces of a semi-octahedron which can be separated into two halves for damage protection. Compensated and uncompensated fault-tolerant system failure decision algorithms were compared. An algorithm to compensate for sensor noise effects in the fault-tolerant system thresholds was evaluated via simulation. The effects of sensor location and magnitude of the vehicle structural modes on system performance were assessed. A threshold generation algorithm, which incorporates noise compensation and filtered parity equation residuals for structural mode compensation, was evaluated. The effects of the fault-tolerant system on navigational accuracy were also considered. A sensor error parametric study was performed in an attempt to improve the soft failure detection capability without obtaining false alarms. Also examined was an FDI system strategy based on the pairwise comparison of sensor measurements. This strategy has the specific advantage of, in many instances, successfully detecting and isolating up to two simultaneously occurring failures.

  9. Functional redundancy of EGF-CFC genes in epiblast and extraembryonic patterning during early mouse embryogenesis.

    Science.gov (United States)

    Chu, Jianhua; Shen, Michael M

    2010-06-01

    During early mouse embryogenesis, multiple patterning and differentiation events require the activity of Nodal, a ligand of the transforming growth factor-beta (TGFbeta) family. Although Nodal signaling is known to require activity of EGF-CFC co-receptors in many contexts, it has been unclear whether all Nodal signaling in the early mouse embryo is EGF-CFC dependent. We have investigated the double null mutant phenotypes for the EGF-CFC genes Cripto and Cryptic, which encode co-receptors for Nodal, and have found that they have partially redundant functions in early mouse development. Expression of Cripto and Cryptic is non-overlapping prior to gastrulation, since Cripto is expressed solely in the epiblast whereas Cryptic is expressed in the primitive endoderm of the late blastocyst and the visceral endoderm after implantation. Despite these non-overlapping expression patterns, Cripto; Cryptic double mutants display severe defects in epiblast, extraembryonic ectoderm, and anterior visceral endoderm (AVE), resulting in phenotypes that are highly similar to those of Nodal null mutants. Our results indicate that both Cripto and Cryptic function non-cell-autonomously during normal development, and that most if not all Nodal activity in early mouse embryogenesis is EGF-CFC-dependent. Copyright 2010 Elsevier Inc. All rights reserved.

  10. Redundant roles of photoreceptors and cytokinins in regulating photosynthetic acclimation to canopy density.

    Science.gov (United States)

    Boonman, A; Prinsen, E; Voesenek, L A C J; Pons, T L

    2009-01-01

    The regulation of photosynthetic acclimation to canopy density was investigated in tobacco canopies and in tobacco and Arabidopsis plants with part of their foliage experimentally shaded. Both species acclimated to canopy light gradients and partial shading by allocating photosynthetic capacity to leaves in high light and adjusting chloroplast organization to the local light conditions. An investigation was carried out to determine whether signalling mediated by photoreceptors, sugars, cytokinin, and nitrate is involved in and necessary for proper photosynthetic acclimation. No evidence was found for a role for sugars, or for nitrate. The distribution of cytokinins in tobacco stands of contrasting density could be explained in part by irradiance-dependent delivery of cytokinins through the transpiration stream. Functional studies using a comprehensive selection of Arabidopsis mutants and transgenics showed that normal wild-type responses to partial shading were retained when signalling mediated by photoreceptors or cytokinins was disrupted. This indicates that these pathways probably operate in a redundant manner. However, the reduction of the chlorophyll a/b ratio in response to local shade was completely absent in the Arabidopsis Ws-2 accession mutated in PHYTOCHROME D and in the triple phyAphyCphyD mutant. Moreover, cytokinin receptor mutants also showed a reduced response, suggesting a previously unrecognized function of phyD and cytokinins.

  11. Redundant mechanisms recruit actin into the contractile ring in silkworm spermatocytes.

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2008-09-01

    Full Text Available Cytokinesis is powered by the contraction of actomyosin filaments within the newly assembled contractile ring. Microtubules are a spindle component that is essential for the induction of cytokinesis. This induction could use central spindle and/or astral microtubules to stimulate cortical contraction around the spindle equator (equatorial stimulation. Alternatively, or in addition, induction could rely on astral microtubules to relax the polar cortex (polar relaxation. To investigate the relationship between microtubules, cortical stiffness, and contractile ring assembly, we used different configurations of microtubules to manipulate the distribution of actin in living silkworm spermatocytes. Mechanically repositioned, noninterdigitating microtubules can induce redistribution of actin at any region of the cortex by locally excluding cortical actin filaments. This cortical flow of actin promotes regional relaxation while increasing tension elsewhere (normally at the equatorial cortex. In contrast, repositioned interdigitating microtubule bundles use a novel mechanism to induce local stimulation of contractility anywhere within the cortex; at the antiparallel plus ends of central spindle microtubules, actin aggregates are rapidly assembled de novo and transported laterally to the equatorial cortex. Relaxation depends on microtubule dynamics but not on RhoA activity, whereas stimulation depends on RhoA activity but is largely independent of microtubule dynamics. We conclude that polar relaxation and equatorial stimulation mechanisms redundantly supply actin for contractile ring assembly, thus increasing the fidelity of cleavage.

  12. A non-redundant protein-RNA docking benchmark version 2.0.

    Science.gov (United States)

    Nithin, Chandran; Mukherjee, Sunandan; Bahadur, Ranjit Prasad

    2017-02-01

    We present an updated version of the protein-RNA docking benchmark, which we first published four years back. The non-redundant protein-RNA docking benchmark version 2.0 consists of 126 test cases, a threefold increase in number compared to its previous version. The present version consists of 21 unbound-unbound cases, of which, in 12 cases, the unbound RNAs are taken from another complex. It also consists of 95 unbound-bound cases where only the protein is available in the unbound state. Besides, we introduce 10 new bound-unbound cases where only the RNA is found in the unbound state. Based on the degree of conformational change of the interface residues upon complex formation the benchmark is classified into 72 rigid-body cases, 25 semiflexible cases and 19 full flexible cases. It also covers a wide range of conformational flexibility including small side chain movement to large domain swapping in protein structures as well as flipping and restacking in RNA bases. This benchmark should provide the docking community with more test cases for evaluating rigid-body as well as flexible docking algorithms. Besides, it will also facilitate the development of new algorithms that require large number of training set. The protein-RNA docking benchmark version 2.0 can be freely downloaded from http://www.csb.iitkgp.ernet.in/applications/PRDBv2. Proteins 2017; 85:256-267. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Redundancy and cooperativity in the mechanics of compositely crosslinked filamentous networks.

    Directory of Open Access Journals (Sweden)

    Moumita Das

    Full Text Available The cytoskeleton of living cells contains many types of crosslinkers. Some crosslinkers allow energy-free rotations between filaments and others do not. The mechanical interplay between these different crosslinkers is an open issue in cytoskeletal mechanics. Therefore, we develop a theoretical framework based on rigidity percolation to study a generic filamentous system containing both stretching and bond-bending forces to address this issue. The framework involves both analytical calculations via effective medium theory and numerical simulations on a percolating triangular lattice with very good agreement between both. We find that the introduction of angle-constraining crosslinkers to a semiflexible filamentous network with freely rotating crosslinks can cooperatively lower the onset of rigidity to the connectivity percolation threshold-a result argued for years but never before obtained via effective medium theory. This allows the system to ultimately attain rigidity at the lowest concentration of material possible. We further demonstrate that introducing angle-constraining crosslinks results in mechanical behaviour similar to just freely rotating crosslinked semflexible filaments, indicating redundancy and universality. Our results also impact upon collagen and fibrin networks in biological and bio-engineered tissues.

  14. The Effect of Variability of Practice at Execution Redundancy Level in Skilled and Novice Basketball Players.

    Science.gov (United States)

    Taheri, Hamidreza; Fazeli, Davoud; Poureghbali, Sogand

    2017-04-01

    We investigated the effect of practice variability through execution redundancy in skilled and novice basketball players on free throw skills. Twelve skilled basketball players and 12 novices (mean age = 25.4 years, SD = 4.3) were divided into four groups (skilled constant, skilled variable, novice constant, and novice variable). After a pretest, participants practiced free throw action. The variable groups threw the ball over an obstacle of varying heights on each trial in random order, whereas the obstacle's height was fixed for the constant groups. After 7 and 14 consecutive days of practice, participants performed two posttests with constant and variable distances from the basket. The results showed that practicing different solutions of a task did not affect the performance of skilled players but had an immediate negative effect on the performance of novice players. Learning a complex task is the result of learning task-related parameters, and practice variability can create a mismatch between task difficulty and new learner skill levels.

  15. Effect of Redundant Haptic Information on Task Performance During Visuo-Tactile Task Interruption and Recovery

    Directory of Open Access Journals (Sweden)

    Hee-Seung Moon

    2016-12-01

    Full Text Available Previous studies have revealed that interruption induces disruptive influences on the performance of cognitive tasks. While much research has focused on the use of multimodal channels to reduce the cost of interruption, few studies have utilized haptic information as more than an associative cue. In the present study, we utilized a multimodal task interruption scenario involving the simultaneous presentation of visual information and haptic stimuli in order to investigate how the combined stimuli affect performance on the primary task (cost of interruption. Participants were asked to perform a two-back visuo-tactile task, in which visual and haptic stimuli were presented simultaneously, which was interrupted by a secondary task that also utilized visual and haptic stimuli. Four experimental conditions were evaluated: (1 paired information (visual stimulus + paired haptic stimulus with interruption; (2 paired information without interruption; (3 non-paired information (visual stimulus + non-paired haptic stimulus with interruption; and (4 non-paired information without interruption. Our findings indicate that, within a visuo-tactile task environment, redundant haptic information may not only increase accuracy on the primary task but also reduce the cost of interruption in terms of accuracy. These results suggest a new way of understanding the task recovery process within a multimodal environment.

  16. Redundant Vasodilator Pathways Underlying Radial Artery Flow-Mediated Dilation Are Preserved in Healthy Aging

    Directory of Open Access Journals (Sweden)

    Kevin D. Ballard

    2014-01-01

    Full Text Available Background. Blocking nitric oxide (NO and vasodilator prostanoids (PN does not consistently reduce flow-mediated dilation (FMD in young adults. The impact of aging on the contribution of NO and PG to FMD is unknown. Methods. FMD was measured in older adults (n=10, 65±3 y after arterial infusion of saline, N(G-monomethyl-L-arginine (L-NMMA, and ketorolac + L-NMMA. Data were compared to published data in young adults. Results. L-NMMA reduced FMD in older adults (8.9±3.6 to 5.9±3.7% although this was not statistically significant (P=0.08 and did not differ (P=0.74 from the reduction observed in young adults (10.0±3.8 to 7.6±4.7%; P=0.03. Blocking PN did not affect FMD in young or older adults. In older adults, L-NMMA reduced (n=6; range = 36–123% decrease, augmented (n=3; 10–122% increase, or did not change FMD (n=1; 0.4% increase. After PN blockade, FMD responses were reduced (n=2, augmented (n=6, or unaffected (n=1. Conclusions. NO or PN blockade did not consistently reduce FMD in healthy older adults, suggesting the existence of redundant vasodilator phenotypes as observed previously in young adults.

  17. Flight test results of failure detection and isolation algorithms for a redundant strapdown inertial measurement unit

    Science.gov (United States)

    Morrell, F. R.; Motyka, P. R.; Bailey, M. L.

    1990-01-01

    Flight test results for two sensor fault-tolerant algorithms developed for a redundant strapdown inertial measurement unit are presented. The inertial measurement unit (IMU) consists of four two-degrees-of-freedom gyros and accelerometers mounted on the faces of a semi-octahedron. Fault tolerance is provided by edge vector test and generalized likelihood test algorithms, each of which can provide dual fail-operational capability for the IMU. To detect the wide range of failure magnitudes in inertial sensors, which provide flight crucial information for flight control and navigation, failure detection and isolation are developed in terms of a multi level structure. Threshold compensation techniques, developed to enhance the sensitivity of the failure detection process to navigation level failures, are presented. Four flight tests were conducted in a commercial transport-type environment to compare and determine the performance of the failure detection and isolation methods. Dual flight processors enabled concurrent tests for the algorithms. Failure signals such as hard-over, null, or bias shift, were added to the sensor outputs as simple or multiple failures during the flights. Both algorithms provided timely detection and isolation of flight control level failures. The generalized likelihood test algorithm provided more timely detection of low-level sensor failures, but it produced one false isolation. Both algorithms demonstrated the capability to provide dual fail-operational performance for the skewed array of inertial sensors.

  18. 3D facial expression recognition using maximum relevance minimum redundancy geometrical features

    Science.gov (United States)

    Rabiu, Habibu; Saripan, M. Iqbal; Mashohor, Syamsiah; Marhaban, Mohd Hamiruce

    2012-12-01

    In recent years, facial expression recognition (FER) has become an attractive research area, which besides the fundamental challenges, it poses, finds application in areas, such as human-computer interaction, clinical psychology, lie detection, pain assessment, and neurology. Generally the approaches to FER consist of three main steps: face detection, feature extraction and expression recognition. The recognition accuracy of FER hinges immensely on the relevance of the selected features in representing the target expressions. In this article, we present a person and gender independent 3D facial expression recognition method, using maximum relevance minimum redundancy geometrical features. The aim is to detect a compact set of features that sufficiently represents the most discriminative features between the target classes. Multi-class one-against-one SVM classifier was employed to recognize the seven facial expressions; neutral, happy, sad, angry, fear, disgust, and surprise. The average recognition accuracy of 92.2% was recorded. Furthermore, inter database homogeneity was investigated between two independent databases the BU-3DFE and UPM-3DFE the results showed a strong homogeneity between the two databases.

  19. Obstacle Avoidance for Redundant Manipulators Utilizing a Backward Quadratic Search Algorithm

    Directory of Open Access Journals (Sweden)

    Tianjian Hu

    2016-06-01

    Full Text Available Obstacle avoidance can be achieved as a secondary task by appropriate inverse kinematics (IK resolution of redundant manipulators. Most prior literature requires the time-consuming determination of the closest point to the obstacle for every calculation step. Aiming at the relief of computational burden, this paper develops what is termed a backward quadratic search algorithm (BQSA as another option for solving IK problems in obstacle avoidance. The BQSA detects possible collisions based on the root property of a category of quadratic functions, which are derived from ellipse-enveloped obstacles and the positions of each link's end-points. The algorithm executes a backward search for possible obstacle collisions, from the end-effector to the base, and avoids obstacles by utilizing a hybrid IK scheme, incorporating the damped least-squares method, the weighted least-norm method and the gradient projection method. Some details of the hybrid IK scheme, such as values of the damped factor, weights and the clamping velocity, are discussed, along with a comparison of computational load between previous methods and BQSA. Simulations of a planar seven-link manipulator and a PUMA 560 robot verify the effectiveness of BQSA.

  20. Tankyrase 1 and tankyrase 2 are essential but redundant for mouse embryonic development.

    Directory of Open Access Journals (Sweden)

    Y Jeffrey Chiang

    2008-07-01

    Full Text Available Tankyrases are proteins with poly(ADP-ribose polymerase activity. Human tankyrases post-translationally modify multiple proteins involved in processes including maintenance of telomere length, sister telomere association, and trafficking of glut4-containing vesicles. To date, however, little is known about in vivo functions for tankyrases. We recently reported that body size was significantly reduced in mice deficient for tankyrase 2, but that these mice otherwise appeared developmentally normal. In the present study, we report generation of tankyrase 1-deficient and tankyrase 1 and 2 double-deficient mice, and use of these mutant strains to systematically assess candidate functions of tankyrase 1 and tankyrase 2 in vivo. No defects were observed in development, telomere length maintenance, or cell cycle regulation in tankyrase 1 or tankyrase 2 knockout mice. In contrast to viability and normal development of mice singly deficient in either tankyrase, deficiency in both tankyrase 1 and tankyrase 2 results in embryonic lethality by day 10, indicating that there is substantial redundancy between tankyrase 1 and tankyrase 2, but that tankyrase function is essential for embryonic development.

  1. Controlled replication: reduce the capacity occupied by redundant replicas in tiled chip multiprocessors

    Science.gov (United States)

    Li, Hao; Xie, Lunguo

    2013-03-01

    The design of cache system for Chip Multiprocessor (CMP) face many challenges because future CMPs will have more cores and greater on-chip cache capacity. There are two base design schemes about L2 cache: private scheme in which each L2 slice is treated as a private L2 cache and shared scheme in which all L2 slices are treated as a large L2 cache shared by all cores. Private caches provide the lowest hit latency but reduce the total effective cache capacity. A shared L2 cache increases the effective cache capacity but has long hit latencies when data is on a remote tile. This paper present a new Controlled Replication (CR) policy to reduce the capacities occupied by redundant shared replicas. the new CR policy increases the effective capacity than victim replication scheme and has lower hit latency than shared scheme. We evaluate the various schemes using full-system simulation of parallel applications. Results show that CR reduces the average memory access latency of shared scheme by an average of 13%, providing better overall performance than victim replication and shared schemes.

  2. Reaction torque control of redundant space robotic systems for orbital maintenance and simulated microgravity tests

    Science.gov (United States)

    Cocuzza, Silvio; Pretto, Isacco; Debei, Stefano

    2010-08-01

    This paper presents the theoretical formulation and the experimental validation of a novel solution for the inverse kinematics of redundant space robotic systems aimed at locally minimizing the torque transferred to the spacecraft due to the robotic arm movement. The differential kinematics is formulated at the acceleration level and an additional constraint is imposed in order to locally minimize the torque transferred to the spacecraft center of mass. This problem can be expressed as a constrained linear least squares problem and a closed-form solution is obtained. An extension of this method is presented in order to take into account the physical limits of the manipulator, by limiting the joint accelerations under acceptable values. In this case the problem can be expressed as a constrained linear least squares problem with both equality and inequality constraints. The proposed solution has been experimentally tested using a 3D free-flying robot previously tested in an ESA Parabolic Flight Campaign. In this test campaign the 3D robot has been converted in a 2D robot taking advantage of its modular structure, and it has been suspended by means of air-bearings on a granite plane. In this way it is possible to perform simulated microgravity tests without time constraints. The base of the robot is fixed on ground by means of a custom design dynamometer, which measures the torque transferred to ground to be minimized. The experimental results validated the proposed solutions and confirmed their good performance.

  3. Autism: Why Act Early?

    Science.gov (United States)

    ... this? Submit What's this? Submit Button Past Emails Autism: Why Act Early? Language: English (US) Español (Spanish) ... helped the world make sense." Florida teenager with Autism Spectrum Disorder "Because my parents acted early, I ...

  4. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... that affects the pancreas and other organs, and how to treat and live with this chronic disease. Role ... of your CF care team can show you how to perform many different ACTs and recommend specific ACTs ...

  5. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... Treatments and Therapies Airway Clearance Airway Clearance Techniques (ACTs) There are different ways to clear your airways. ... or caregiver. Older kids and adults can choose ACTs that they can do on their own. Share ...

  6. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... CF Treatments and Therapies Airway Clearance Airway Clearance Techniques (ACTs) There are different ways to clear your ... for fitting ACTs into daily life Airway Clearance Techniques | Webcast To learn more about how you can ...

  7. Mechanical fault diagnosis based on redundant second generation wavelet packet transform, neighborhood rough set and support vector machine

    Science.gov (United States)

    Li, Ning; Zhou, Rui; Hu, Qinghua; Liu, Xiaohang

    2012-04-01

    This paper investigates the application of the redundant second generation wavelet package transform (RSGWPT), neighborhood rough set (NRS) and support vector machine (SVM) on faulty detection, attribute reduction and pattern classification. On this basis, a novel method for mechanical faulty diagnosis based on RSGWPT, NRS and SVM is presented, which utilizes the RSGWPT to extract faulty feature parameters from the statistical characteristics of wavelet package coefficients to constitute feature vectors, and then makes the attribute reduction by NRS method to obtain the key features, lastly these key features are input into SVM to accomplish faulty pattern classification. The experimental results of the proposed method to fault diagnosis of the gearbox and gasoline engine valve trains show that this method can extract the faulty features, which have better classification ability and at the same time reduce a lot of redundant features in case of assuring the classification accuracy, accordingly improve the classifier efficiency and achieve a better classification performance.

  8. Reliability analysis and fault-tolerant system development for a redundant strapdown inertial measurement unit. [inertial platforms

    Science.gov (United States)

    Motyka, P.

    1983-01-01

    A methodology is developed and applied for quantitatively analyzing the reliability of a dual, fail-operational redundant strapdown inertial measurement unit (RSDIMU). A Markov evaluation model is defined in terms of the operational states of the RSDIMU to predict system reliability. A 27 state model is defined based upon a candidate redundancy management system which can detect and isolate a spectrum of failure magnitudes. The results of parametric studies are presented which show the effect on reliability of the gyro failure rate, both the gyro and accelerometer failure rates together, false alarms, probability of failure detection, probability of failure isolation, and probability of damage effects and mission time. A technique is developed and evaluated for generating dynamic thresholds for detecting and isolating failures of the dual, separated IMU. Special emphasis is given to the detection of multiple, nonconcurrent failures. Digital simulation time histories are presented which show the thresholds obtained and their effectiveness in detecting and isolating sensor failures.

  9. Acquired tricuspid valve stenosis due to intentionally redundant transvenous lead placement for VDD pacing in two small dogs.

    Science.gov (United States)

    Gunther-Harrington, Catherine T; Michel, Adam O; Stern, Joshua A

    2015-12-01

    Placement of an endocardial VDD pacing lead in small dogs (dogs between 8 months and 4 years after VDD pacemaker placement for third-degree atrioventricular block. Echocardiography and Doppler echocardiography identified elevated transtricuspid flow velocities, prolonged pressure half-times, decreased valve leaflet excursions, and tricuspid regurgitation in both cases. Both cases were euthanized secondary to this pacing complication. Necropsy was performed in one case and confirmed adherence between the redundant lead loop, atrial and valve tissue. While VDD pacing in dogs has proven hemodynamic benefits, these benefits have not been demonstrated in terms of survival benefit or clinical signs. The requirement of redundant lead placement in small dogs for appropriate VDD lead function creates potential deleterious effects that should be weighed against the possible clinical value of VDD pacing in these patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Redundant role of protein kinase C delta and epsilon during mouse embryonic development.

    Directory of Open Access Journals (Sweden)

    Sergio Carracedo

    Full Text Available Protein Kinase C delta and epsilon are mediators of important cellular events, such as cell proliferation, migration or apoptosis. The formation of blood vessels, i.e., vasculo- and angiogenesis, is a process where these isoforms have also been shown to participate. However, mice deficient in either Protein Kinase C delta or epsilon are viable and therefore their individual contribution to the formation of the vasculature appeared so far dispensable. In this study, we show that double null mutation of Protein Kinase C delta and epsilon causes embryonic lethality at approximately E9.5. At this stage, whole mount staining of the endothelial marker CD31 in double null embryos revealed defective blood vessel formation. Moreover, culture of double deficient mouse allantois showed impaired endothelial cell organization, and analyses of double deficient embryo sections showed dilated vessels, decreased endothelial-specific adherent junctions, and decreased contact of endothelial cells with mural cells. Protein kinase C delta and epsilon also appeared essential for vascular smooth muscle cell differentiation, since α-smooth muscle actin, a classical marker for vascular smooth muscle cells, was almost undetectable in double deficient embryonic aorta at E9.5. Subsequent qPCR analyses showed decreased VE-cadherin, Vegfr2, Cd31, Cdh2, Ets1, and Fli-1, among other angiogenesis related transcripts in double deficient embryos. Taken together, these data suggest for the first time an in vivo redundant role between members of the novel Protein Kinase C subfamily that allows for mutual compensation during mouse embryonic development, with vasculogenesis/angiogenesis as an obvious common function of these two Protein Kinase Cs. Protein Kinase C delta and epsilon might therefore be useful targets for inhibiting vasculo- and/or angiogenesis.

  11. Integrating desalination to reservoir operation to increase redundancy for more secure water supply

    Science.gov (United States)

    Bhushan, Rashi; Ng, Tze Ling

    2016-08-01

    We investigate the potential of integrating desalination to existing reservoir systems to mitigate supply uncertainty. Desalinated seawater and wastewater are relatively reliable but expensive. Water from natural resources like reservoirs is generally cheaper but climate sensitive. We propose combining the operation of a reservoir and seawater and wastewater desalination plants for an overall system that is less vulnerable to scarcity and uncertainty, while constraining total cost. The joint system is modeled as a multiobjective optimization problem with the double objectives of minimizing risk and vulnerability, subject to a minimum limit on resilience. The joint model is applied to two cases, one based on the climate and demands of a location in India and the other of a location in California. The results for the Indian case indicate that it is possible for the joint system to reduce risk and vulnerability to zero given a budget increase of 20-120% under current climate conditions and 30-150% under projected future conditions. For the Californian case, this would require budget increases of 20-80% and 30-140% under current and future conditions, respectively. Further, our analysis shows a two-way interaction between the reservoir and desalination plants where the optimal operation of the former is just as much affected by the latter as the latter by the former. This highlights the importance of an integrated management approach. This study contributes to a greater quantitative understanding of desalination as a redundancy measure for adapting water supply infrastructures for a future of greater scarcity and uncertainty.

  12. a Redundant Gnss-Ins Low-Cost Uav Navigation Solution for Professional Applications

    Science.gov (United States)

    Navarro, J.; Parés, M. E.; Colomina, I.; Bianchi, G.; Pluchino, S.; Baddour, R.; Consoli, A.; Ayadi, J.; Gameiro, A.; Sekkas, O.; Tsetsos, V.; Gatsos, T.; Navoni, R.

    2015-08-01

    This paper presents the current results for the FP7 GINSEC project. Its goal is to build a pre-commercial prototype of a low-cost, accurate and reliable system for the professional UAV market. Low-cost, in this context, stands for the use of sensors in the most affordable segment of the market, especially MEMS IMUs and GNSS receivers. Reliability applies to the ability of the autopilot to cope with situations where unfavourable GNSS reception conditions or strong electromagnetic fields make the computation of the position and / or attitude of the UAV difficult. Professional and accurate mean that, at least using post-processing techniques as PPP, it will be possible to reach cm-level precisions that open the door to a range of applications demanding high levels of quality in positioning, as precision agriculture or mapping. To achieve such goal, a rigorous sensor error modelling approach, the use of redundant IMUs and a dual-GNSS receiver setup, together with close-coupling techniques and an extended Kalman filter with self-analysis capabilities have been used. Although the project is not yet complete, the results obtained up to now prove the feasibility of the aforementioned goal, especially in those aspects related to position determination. Research work is still undergoing to estimate the heading using a dual-GNNS receiver setup; preliminary results prove the validity of this approach for relatively long baselines, although positive results are expected when these are shorter than 1 m - which is a necessary requisite for small-sized UAVs.

  13. Redundant prepuce increases the odds of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).

    Science.gov (United States)

    Zhao, Yu-Yang; Xu, Dong-Liang; Zhao, Fu-Jun; Han, Bang-Min; Shao, Yi; Zhao, Wei; Xia, Shu-Jie

    2014-01-01

    Some published evidence has revealed that the dendritic cells can interact with pathogens that exist in the inner foreskin. This information provides a new vision that pathogens could play a role through the redundant prepuce; numerous studies have failed to find pathogens in prostates of patients who had chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). However, no studies have reported an association between foreskin length and CP/CPPS. Hence, we conducted a retrospective case-control study of clinical data from 322 CP/CPPS patients (case group) and 341 nonCP/CPPS patients (control group). Demographic characteristics, lifestyle factors, and foreskin lengths were collected and analyzed. Multivariate logistic regression was adopted to calculate the odds of foreskin length for CP/CPPS. According to the multivariate logistic regression results, when the foreskin length covered up more than half of the glans penis, the odds for CP/CPPS were higher with an increased foreskin (odds ratio (OR): 1.66, 95% confidence interval (CI): 1.04-2.66). In comparison, when the glans penis was completely covered by the foreskin, the OR value increased to 1.86 (95% CI, 1.2-2.88). The study results showed an association between foreskin length and the odds of CP/CPPS. When the foreskin length covered up more than half of the glans penis, there were greater odds for CP/CPPS. This possible mechanism might result from interaction between pathogens and DCs in the inner foreskin, consequently activating T-cells to mediate allergic inflammation in the prostate and producing the autoimmunizations causing CP/CPPS.

  14. A REDUNDANT GNSS-INS LOW-COST UAV NAVIGATION SOLUTION FOR PROFESSIONAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    J. Navarro

    2015-08-01

    Full Text Available This paper presents the current results for the FP7 GINSEC project. Its goal is to build a pre-commercial prototype of a low-cost, accurate and reliable system for the professional UAV market. Low-cost, in this context, stands for the use of sensors in the most affordable segment of the market, especially MEMS IMUs and GNSS receivers. Reliability applies to the ability of the autopilot to cope with situations where unfavourable GNSS reception conditions or strong electromagnetic fields make the computation of the position and / or attitude of the UAV difficult. Professional and accurate mean that, at least using post-processing techniques as PPP, it will be possible to reach cm-level precisions that open the door to a range of applications demanding high levels of quality in positioning, as precision agriculture or mapping. To achieve such goal, a rigorous sensor error modelling approach, the use of redundant IMUs and a dual-GNSS receiver setup, together with close-coupling techniques and an extended Kalman filter with self-analysis capabilities have been used. Although the project is not yet complete, the results obtained up to now prove the feasibility of the aforementioned goal, especially in those aspects related to position determination. Research work is still undergoing to estimate the heading using a dual-GNNS receiver setup; preliminary results prove the validity of this approach for relatively long baselines, although positive results are expected when these are shorter than 1 m – which is a necessary requisite for small-sized UAVs.

  15. FON2 SPARE1 Redundantly Regulates Floral Meristem Maintenance with FLORAL ORGAN NUMBER2 in Rice

    Science.gov (United States)

    Suzaki, Takuya; Ohneda, Masako; Toriba, Taiyo; Yoshida, Akiko; Hirano, Hiro-Yuki

    2009-01-01

    CLAVATA signaling restricts stem cell identity in the shoot apical meristem (SAM) in Arabidopsis thaliana. In rice (Oryza sativa), FLORAL ORGAN NUMBER2 (FON2), closely related to CLV3, is involved as a signaling molecule in a similar pathway to negatively regulate stem cell proliferation in the floral meristem (FM). Here we show that the FON2 SPARE1 (FOS1) gene encoding a CLE protein functions along with FON2 in maintenance of the FM. In addition, FOS1 appears to be involved in maintenance of the SAM in the vegetative phase, because constitutive expression of FOS1 caused termination of the vegetative SAM. Genetic analysis revealed that FOS1 does not need FON1, the putative receptor of FON2, for its action, suggesting that FOS1 and FON2 may function in meristem maintenance as signaling molecules in independent pathways. Initially, we identified FOS1 as a suppressor that originates from O. sativa indica and suppresses the fon2 mutation in O. sativa japonica. FOS1 function in japonica appears to be compromised by a functional nucleotide polymorphism (FNP) at the putative processing site of the signal peptide. Sequence comparison of FOS1 in about 150 domesticated rice and wild rice species indicates that this FNP is present only in japonica, suggesting that redundant regulation by FOS1 and FON2 is commonplace in species in the Oryza genus. Distribution of the FNP also suggests that this mutation may have occurred during the divergence of japonica from its wild ancestor. Stem cell maintenance may be regulated by at least three negative pathways in rice, and each pathway may contribute differently to this regulation depending on the type of the meristem. This situation contrasts with that in Arabidopsis, where CLV signaling is the major single pathway in all meristems. PMID:19834537

  16. FON2 SPARE1 redundantly regulates floral meristem maintenance with FLORAL ORGAN NUMBER2 in rice.

    Directory of Open Access Journals (Sweden)

    Takuya Suzaki

    2009-10-01

    Full Text Available CLAVATA signaling restricts stem cell identity in the shoot apical meristem (SAM in Arabidopsis thaliana. In rice (Oryza sativa, FLORAL ORGAN NUMBER2 (FON2, closely related to CLV3, is involved as a signaling molecule in a similar pathway to negatively regulate stem cell proliferation in the floral meristem (FM. Here we show that the FON2 SPARE1 (FOS1 gene encoding a CLE protein functions along with FON2 in maintenance of the FM. In addition, FOS1 appears to be involved in maintenance of the SAM in the vegetative phase, because constitutive expression of FOS1 caused termination of the vegetative SAM. Genetic analysis revealed that FOS1 does not need FON1, the putative receptor of FON2, for its action, suggesting that FOS1 and FON2 may function in meristem maintenance as signaling molecules in independent pathways. Initially, we identified FOS1 as a suppressor that originates from O. sativa indica and suppresses the fon2 mutation in O. sativa japonica. FOS1 function in japonica appears to be compromised by a functional nucleotide polymorphism (FNP at the putative processing site of the signal peptide. Sequence comparison of FOS1 in about 150 domesticated rice and wild rice species indicates that this FNP is present only in japonica, suggesting that redundant regulation by FOS1 and FON2 is commonplace in species in the Oryza genus. Distribution of the FNP also suggests that this mutation may have occurred during the divergence of japonica from its wild ancestor. Stem cell maintenance may be regulated by at least three negative pathways in rice, and each pathway may contribute differently to this regulation depending on the type of the meristem. This situation contrasts with that in Arabidopsis, where CLV signaling is the major single pathway in all meristems.

  17. Due to interleukin-6 type cytokine redundancy only glycoprotein 130 receptor blockade efficiently inhibits myeloma growth

    Science.gov (United States)

    Burger, Renate; Günther, Andreas; Klausz, Katja; Staudinger, Matthias; Peipp, Matthias; Penas, Eva Maria Murga; Rose-John, Stefan; Wijdenes, John; Gramatzki, Martin

    2017-01-01

    Interleukin-6 has an important role in the pathophysiology of multiple myeloma where it supports the growth and survival of the malignant plasma cells in the bone marrow. It belongs to a family of cytokines which use the glycoprotein 130 chain for signal transduction, such as oncostatin M or leukemia inhibitory factor. Targeting interleukin-6 in plasma cell diseases is currently evaluated in clinical trials with monoclonal antibodies. Here, efforts were made to elucidate the contribution of interleukin-6 and glycoprotein 130 signaling in malignant plasma cell growth in vivo. In the xenograft severe combined immune deficiency model employing our interleukin-6-dependent plasma cell line INA-6, the lack of human interleukin-6 induced autocrine interleukin-6 production and a proliferative response to other cytokines of the glycoprotein 130 family. Herein, mice were treated with monoclonal antibodies against human interleukin-6 (elsilimomab/B-E8), the interleukin-6 receptor (B-R6), and with an antibody blocking glycoprotein 130 (B-R3). While treatment of mice with interleukin-6 and interleukin-6 receptor antibodies resulted in a modest delay in tumor growth, the development of plasmacytomas was completely prevented with the anti-glycoprotein 130 antibody. Importantly, complete inhibition was also achieved using F(ab’)2-fragments of monoclonal antibody B-R3. Tumors harbor activated signal transducer and activator of transcription 3, and in vitro, the antibody inhibited leukemia inhibitory factor stimulated signal transducer and activator of transcription 3 phosphorylation and cell growth, while being less effective against interleukin-6. In conclusion, the growth of INA-6 plasmacytomas in vivo under interleukin-6 withdrawal remains strictly dependent on glycoprotein 130, and other glycoprotein 130 cytokines may substitute for interleukin-6. Antibodies against glycoprotein 130 are able to overcome this redundancy and should be explored for a possible therapeutic window

  18. Simulating GPS radio signal to synchronize network--a new technique for redundant timing.

    Science.gov (United States)

    Shan, Qingxiao; Jun, Yang; Le Floch, Jean-Michel; Fan, Yaohui; Ivanov, Eugene N; Tobar, Michael E

    2014-07-01

    Currently, many distributed systems such as 3G mobile communications and power systems are time synchronized with a Global Positioning System (GPS) signal. If there is a GPS failure, it is difficult to realize redundant timing, and thus time-synchronized devices may fail. In this work, we develop time transfer by simulating GPS signals, which promises no extra modification to original GPS-synchronized devices. This is achieved by applying a simplified GPS simulator for synchronization purposes only. Navigation data are calculated based on a pre-assigned time at a fixed position. Pseudo-range data which describes the distance change between the space vehicle (SV) and users are calculated. Because real-time simulation requires heavy-duty computations, we use self-developed software optimized on a PC to generate data, and save the data onto memory disks while the simulator is operating. The radio signal generation is similar to the SV at an initial position, and the frequency synthesis of the simulator is locked to a pre-assigned time. A filtering group technique is used to simulate the signal transmission delay corresponding to the SV displacement. Each SV generates a digital baseband signal, where a unique identifying code is added to the signal and up-converted to generate the output radio signal at the centered frequency of 1575.42 MHz (L1 band). A prototype with a field-programmable gate array (FPGA) has been built and experiments have been conducted to prove that we can realize time transfer. The prototype has been applied to the CDMA network for a three-month long experiment. Its precision has been verified and can meet the requirements of most telecommunication systems.

  19. Functional Redundancy Facilitates Resilience of Subarctic Phytoplankton Assemblages toward Ocean Acidification and High Irradiance

    Directory of Open Access Journals (Sweden)

    Clara J. M. Hoppe

    2017-07-01

    Full Text Available In order to understand how ocean acidification (OA and enhanced irradiance levels might alter phytoplankton eco-physiology, productivity and species composition, we conducted an incubation experiment with a natural plankton assemblage from sub-surface Subarctic waters (Davis Strait, 63°N. The phytoplankton assemblage was exposed to 380 and 1,000 μatm pCO2 at both 15 and 35% surface irradiance over 2 weeks. The incubations were monitored and characterized in terms of their photo-physiology, biomass stoichiometry, primary production and dominant phytoplankton species. We found that the phytoplankton assemblage exhibited pronounced high-light stress in the first days of the experiment (20–30% reduction in photosynthetic efficiency, Fv/Fm. This stress signal was more pronounced when grown under OA and high light, indicating interactive effects of these environmental variables. Primary production in the high light treatments was reduced by 20% under OA compared to ambient pCO2 levels. Over the course of the experiment, the assemblage fully acclimated to the applied treatments, achieving similar bulk characteristics (e.g., net primary production and elemental stoichiometry under all conditions. We did, however, observe a pCO2-dependent shift in the dominant diatom species, with Pseudonitzschia sp. dominating under low and Fragilariopsis sp. under high pCO2 levels. Our results indicate an unexpectedly high level of resilience of Subarctic phytoplankton to OA and enhanced irradiance levels. The co-occurring shift in dominant species suggests functional redundancy to be an important, but so-far largely overlooked mechanism for resilience toward climate change.

  20. Redundant prepuce increases the odds of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS

    Directory of Open Access Journals (Sweden)

    Yu-Yang Zhao

    2014-10-01

    Full Text Available Some published evidence has revealed that the dendritic cells can interact with pathogens that exist in the inner foreskin. This information provides a new vision that pathogens could play a role through the redundant prepuce; numerous studies have failed to find pathogens in prostates of patients who had chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS. However, no studies have reported an association between foreskin length and CP/CPPS. Hence, we conducted a retrospective case-control study of clinical data from 322 CP/CPPS patients (case group and 341 nonCP/CPPS patients (control group. Demographic characteristics, lifestyle factors, and foreskin lengths were collected and analyzed. Multivariate logistic regression was adopted to calculate the odds of foreskin length for CP/CPPS. According to the multivariate logistic regression results, when the foreskin length covered up more than half of the glans penis, the odds for CP/CPPS were higher with an increased foreskin (odds ratio (OR: 1.66, 95% confidence interval (CI: 1.04-2.66. In comparison, when the glans penis was completely covered by the foreskin, the OR value increased to 1.86 (95% CI, 1.2-2.88. The study results showed an association between foreskin length and the odds of CP/CPPS. When the foreskin length covered up more than half of the glans penis, there were greater odds for CP/CPPS. This possible mechanism might result from interaction between pathogens and DCs in the inner foreskin, consequently activating T-cells to mediate allergic inflammation in the prostate and producing the autoimmunizations causing CP/CPPS.

  1. Redundant and diverse intranodal pacemakers and conduction pathways protect the human sinoatrial node from failure.

    Science.gov (United States)

    Li, Ning; Hansen, Brian J; Csepe, Thomas A; Zhao, Jichao; Ignozzi, Anthony J; Sul, Lidiya V; Zakharkin, Stanislav O; Kalyanasundaram, Anuradha; Davis, Jonathan P; Biesiadecki, Brandon J; Kilic, Ahmet; Janssen, Paul M L; Mohler, Peter J; Weiss, Raul; Hummel, John D; Fedorov, Vadim V

    2017-07-26

    The human sinoatrial node (SAN) efficiently maintains heart rhythm even under adverse conditions. However, the specific mechanisms involved in the human SAN's ability to prevent rhythm failure, also referred to as its robustness, are unknown. Challenges exist because the three-dimensional (3D) intramural structure of the human SAN differs from well-studied animal models, and clinical electrode recordings are limited to only surface atrial activation. Hence, to innovate the translational study of human SAN structural and functional robustness, we integrated intramural optical mapping, 3D histology reconstruction, and molecular mapping of the ex vivo human heart. When challenged with adenosine or atrial pacing, redundant intranodal pacemakers within the human SAN maintained automaticity and delivered electrical impulses to the atria through sinoatrial conduction pathways (SACPs), thereby ensuring a fail-safe mechanism for robust maintenance of sinus rhythm. During adenosine perturbation, the primary central SAN pacemaker was suppressed, whereas previously inactive superior or inferior intranodal pacemakers took over automaticity maintenance. Sinus rhythm was also rescued by activation of another SACP when the preferential SACP was suppressed, suggesting two independent fail-safe mechanisms for automaticity and conduction. The fail-safe mechanism in response to adenosine challenge is orchestrated by heterogeneous differences in adenosine A1 receptors and downstream GIRK4 channel protein expressions across the SAN complex. Only failure of all pacemakers and/or SACPs resulted in SAN arrest or conduction block. Our results unmasked reserve mechanisms that protect the human SAN pacemaker and conduction complex from rhythm failure, which may contribute to treatment of SAN arrhythmias. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  2. A dynamic microbial community with high functional redundancy inhabits the cold, oxic subseafloor aquifer.

    Science.gov (United States)

    Tully, Benjamin J; Wheat, C Geoff; Glazer, Brain T; Huber, Julie A

    2017-11-03

    The rock-hosted subseafloor crustal aquifer harbors a reservoir of microbial life that may influence global marine biogeochemical cycles. Here we utilized metagenomic libraries of crustal fluid samples from North Pond, located on the flanks of the Mid-Atlantic Ridge, a site with cold, oxic subseafloor fluid circulation within the upper basement to query microbial diversity. Twenty-one samples were collected during a 2-year period to examine potential microbial metabolism and community dynamics. We observed minor changes in the geochemical signatures over the 2 years, yet the microbial community present in the crustal fluids underwent large shifts in the dominant taxonomic groups. An analysis of 195 metagenome-assembled genomes (MAGs) were generated from the data set and revealed a connection between litho- and autotrophic processes, linking carbon fixation to the oxidation of sulfide, sulfur, thiosulfate, hydrogen, and ferrous iron in members of the Proteobacteria, specifically the Alpha-, Gamma- and Zetaproteobacteria, the Epsilonbacteraeota and the Planctomycetes. Despite oxic conditions, analysis of the MAGs indicated that members of the microbial community were poised to exploit hypoxic or anoxic conditions through the use of microaerobic cytochromes, such as cbb3- and bd-type cytochromes, and alternative electron acceptors, like nitrate and sulfate. Temporal and spatial trends from the MAGs revealed a high degree of functional redundancy that did not correlate with the shifting microbial community membership, suggesting functional stability in mediating subseafloor biogeochemical cycles. Collectively, the repeated sampling at multiple sites, together with the successful binning of hundreds of genomes, provides an unprecedented data set for investigation of microbial communities in the cold, oxic crustal aquifer.The ISME Journal advance online publication, 3 November 2017; doi:10.1038/ismej.2017.187.

  3. Microbial community redundancy in anaerobic digestion drives process recovery after salinity exposure.

    Science.gov (United States)

    De Vrieze, Jo; Christiaens, Marlies E R; Walraedt, Diego; Devooght, Arno; Ijaz, Umer Zeeshan; Boon, Nico

    2017-03-15

    Anaerobic digestion of high-salinity wastewaters often results in process inhibition due to the susceptibility of the methanogenic archaea. The ability of the microbial community to deal with increased salinity levels is of high importance to ensure process perseverance or recovery after failure. The exact strategy of the microbial community to ensure process endurance is, however, often unknown. In this study, we investigated how the microbial community is able to recover process performance following a disturbance through the application of high-salinity molasses wastewater. After a stable start-up, methane production quickly decreased from 625 ± 17 to 232 ± 35 mL CH4 L-1 d-1 with a simultaneous accumulation in volatile fatty acids up to 20.5 ± 1.4 g COD L-1, indicating severe process disturbance. A shift in feedstock from molasses wastewater to waste activated sludge resulted in complete process recovery. However, the bacterial and archaeal communities did not return to their original composition as before the disturbance, despite similar process conditions. Microbial community diversity was recovered to similar levels as before disturbance, which indicates that the metabolic potential of the community was maintained. A mild increase in ammonia concentration after process recovery did not influence methane production, indicating a well-balanced microbial community. Hence, given the change in community composition following recovery after salinity disturbance, it can be assumed that microbial community redundancy was the major strategy to ensure the continuation of methane production, without loss of functionality or metabolic flexibility. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Decommissioning and Demolition of a Redundant UK Research Facility at AWE Aldermaston - 12453

    Energy Technology Data Exchange (ETDEWEB)

    Pritchard, Paul [Atomic Weapons Establishment, Aldermaston (United Kingdom)

    2012-07-01

    The redundant two-storey brick built research facility on the AWE Site at Aldermaston, UK is in the closing stages of decommissioning and demolition. The facility was used for a variety of purposes up to 1995 predominately involving the use of alpha-emitting isotopes. The two main areas of alpha-based contamination have been decommissioned with the removal of hot -boxes and fume cupboards on the ground floor and HEPA filter units and ventilation equipment on the first floor. Many of these activities were undertaken using both airline fed suits, (supplied via a free standing mobile unit), and full face respirators. Asbestos materials were located and cleared from the first floor by specialist contractor. All sections of active drain running from the building to the site active effluent disposal system were removed early in the program using established techniques with specialist monitoring equipment used to provide confidence in the data required for disposal of the decommissioning debris. In particular a dedicated High Resolution Gamma Spectrometer (radioactive materials scanning unit) was utilized to categorise waste drums and wrapped packages. The building has been decommissioned and the monitoring and sampling of the structure was completed in November 2011 - the results demonstrating that the building was clear of contamination in accordance with UK clearance and exemption requirements. The demolition plan was developed and implemented in December with site excavation of foundations and site clearance currently ongoing in preparation for final site backfill activities and project close. A number of useful lessons have been learnt during the operations and are set out at the rear of the main text. (authors)

  5. Decommissioning and demolition of a redundant UK research facility at AWE Aldermaston

    Energy Technology Data Exchange (ETDEWEB)

    Miller, K. [NUVIA Limited, Warrington, Cheshire (United Kingdom); Barnes, I. [AWE, Aldermaston, Berkshire (United Kingdom)

    2011-07-01

    The redundant two-storey, brick built research facility on the AWE Site at Aldermaston, UK is in the latter stages of decommissioning by Nuvia Limited. The facility was used for a variety of purposes up to 1995 involving the use predominately of alpha-emitting isotopes. After a period of site establishment and preparation of supporting safety case documentation, the two main areas of alpha-based contamination have largely been decommissioned with the removal of hot -boxes and fume cupboards on the ground floor and HEPA filter units and ventilation equipment on the first floor. Many of these activities have been undertaken using both airline fed suits and respirators, the former supplied from a free standing, mobile unit newly located outside the building to allow reuse on future projects. The late detection of exposed asbestos on the first floor associated with an electrostatic particulate filter caused some delay to the programme but these materials have now been removed by a specialist contractor to allow the programme to continue. At an early stage of the programme all sections of active drains running from the building to the site-based active effluent disposal system have been removed from the external drain ducts without incident using well-established techniques. Specialist monitoring equipment is being used in order to provide confidence in the data required for disposal of the decommissioning debris. In particular a dedicated high resolution gamma scanning unit for waste drums and wrapped packages has been utilised. The final stages of the building decommissioning are in sight and the monitoring and sampling of the structure will become important milestones ahead of the development of the demolition plan. A number of useful lessons have been learnt during the operations and are set out in the main text of this paper. (author)

  6. LytB1 and LytB2 of Mycobacterium tuberculosis Are Not Genetically Redundant.

    Directory of Open Access Journals (Sweden)

    Amanda Claire Brown

    Full Text Available Mycobacterium tuberculosis synthesises isoprenoid precursors via the MEP/DOXP pathway and at least five enzymes in the pathway (Dxs1, Dxr/IspC, IspD, IspF, and GcpE/IspG are required for growth in vitro. We investigated the role of LytB (IspH in M. tuberculosis; M. tuberculosis is unusual in that it has two homologs-LytB1 and LytB2. We were unable to delete the lytB2 gene unless we provided an additional copy elsewhere, demonstrating that this is the essential homolog. We expressed lytB1 from the lytB2 promoter and confirmed that this could not complement for loss of function of lytB2, despite LytB1 possessing all the previously described conserved critical residues. Interestingly the sole LytB homolog of Mycobacterium smegmatis was able to compensate for loss of LytB2 in M. tuberculosis. We tested translational fusions of LytB1 and LytB2 for functionality in M. tuberculosis, but only a fusion with 90% N-terminal LytB2 and 10% C-terminal LytB1 was functional. In order to identify the key difference between the two proteins, site directed mutagenesis was used to change LytB2 residues into their counterparts in LytB1. None of these amino acid substitutions was essential for function and all lytB2 mutant alleles were functional. In contrast, mutation of the key residues for [Fe4S4] cluster formation, as well as a catalytic residue in LytB1 did not result in functional complementation. Thus, although LytB1 and LytB2 are not genetically redundant, this is not dependent on small amino acid changes, but is likely to be a result of major overall structural differences.

  7. Functional Redundancy of Linuron Degradation in Microbial Communities in Agricultural Soil and Biopurification Systems.

    Science.gov (United States)

    Horemans, Benjamin; Bers, Karolien; Ruiz Romero, Erick; Pose Juan, Eva; Dunon, Vincent; De Mot, René; Springael, Dirk

    2016-05-01

    The abundance of libA, encoding a hydrolase that initiates linuron degradation in the linuron-metabolizing Variovorax sp. strain SRS16, was previously found to correlate well with linuron mineralization, but not in all tested environments. Recently, an alternative linuron hydrolase, HylA, was identified in Variovorax sp. strain WDL1, a strain that initiates linuron degradation in a linuron-mineralizing commensal bacterial consortium. The discovery of alternative linuron hydrolases poses questions about the respective contribution and competitive character of hylA- and libA-carrying bacteria as well as the role of linuron-mineralizing consortia versus single strains in linuron-exposed settings. Therefore, dynamics of hylA as well as dcaQ as a marker for downstream catabolic functions involved in linuron mineralization, in response to linuron treatment in agricultural soil and on-farm biopurification systems (BPS), were compared with previously reported libA dynamics. The results suggest that (i) organisms containing either libA or hylA contribute simultaneously to linuron biodegradation in the same environment, albeit to various extents, (ii) environmental linuron mineralization depends on multispecies bacterial food webs, and (iii) initiation of linuron mineralization can be governed by currently unidentified enzymes. A limited set of different isofunctional catabolic gene functions is known for the bacterial degradation of the phenylurea herbicide linuron, but the role of this redundancy in linuron degradation in environmental settings is not known. In this study, the simultaneous involvement of bacteria carrying one of two isofunctional linuron hydrolysis genes in the degradation of linuron was shown in agricultural soil and on-farm biopurification systems, as was the involvement of other bacterial populations that mineralize the downstream metabolites of linuron hydrolysis. This study illustrates the importance of the synergistic metabolism of pesticides in

  8. AN IMAGE-PLANE ALGORITHM FOR JWST'S NON-REDUNDANT APERTURE MASK DATA

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Alexandra Z. [Johns Hopkins University Department of Physics and Astronomy 3400 North Charles, Baltimore, MD 21218 (United States); Pueyo, Laurent; Sivaramakrishnan, Anand [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Lacour, Sylvestre [LESIA, CNRS/UMR-8109, Observatoire de Paris, UPMC, Université Paris Diderot 5 place Jules Janssen, 92195 Meudon (France)

    2015-01-10

    The high angular resolution technique of non-redundant masking (NRM) or aperture masking interferometry (AMI) has yielded images of faint protoplanetary companions of nearby stars from the ground. AMI on James Webb Space Telescope (JWST)'s Near Infrared Imager and Slitless Spectrograph (NIRISS) has a lower thermal background than ground-based facilities and does not suffer from atmospheric instability. NIRISS AMI images are likely to have 90%-95% Strehl ratio between 2.77 and 4.8 μm. In this paper we quantify factors that limit the raw point source contrast of JWST NRM. We develop an analytic model of the NRM point spread function which includes different optical path delays (pistons) between mask holes and fit the model parameters with image plane data. It enables a straightforward way to exclude bad pixels, is suited to limited fields of view, and can incorporate effects such as intra-pixel sensitivity variations. We simulate various sources of noise to estimate their effect on the standard deviation of closure phase, σ{sub CP} (a proxy for binary point source contrast). If σ{sub CP} < 10{sup –4} radians—a contrast ratio of 10 mag—young accreting gas giant planets (e.g., in the nearby Taurus star-forming region) could be imaged with JWST NIRISS. We show the feasibility of using NIRISS' NRM with the sub-Nyquist sampled F277W, which would enable some exoplanet chemistry characterization. In the presence of small piston errors, the dominant sources of closure phase error (depending on pixel sampling, and filter bandwidth) are flat field errors and unmodeled variations in intra-pixel sensitivity. The in-flight stability of NIRISS will determine how well these errors can be calibrated by observing a point source. Our results help develop efficient observing strategies for space-based NRM.

  9. Single Event Test Methodologies and System Error Rate Analysis for Triple Modular Redundant Field Programmable Gate Arrays

    Science.gov (United States)

    Allen, Gregory; Edmonds, Larry D.; Swift, Gary; Carmichael, Carl; Tseng, Chen Wei; Heldt, Kevin; Anderson, Scott Arlo; Coe, Michael

    2010-01-01

    We present a test methodology for estimating system error rates of Field Programmable Gate Arrays (FPGAs) mitigated with Triple Modular Redundancy (TMR). The test methodology is founded in a mathematical model, which is also presented. Accelerator data from 90 nm Xilins Military/Aerospace grade FPGA are shown to fit the model. Fault injection (FI) results are discussed and related to the test data. Design implementation and the corresponding impact of multiple bit upset (MBU) are also discussed.

  10. Changes in bird functional diversity across multiple land uses: interpretations of functional redundancy depend on functional group identity.

    Science.gov (United States)

    Luck, Gary W; Carter, Andrew; Smallbone, Lisa

    2013-01-01

    Examinations of the impact of land-use change on functional diversity link changes in ecological community structure driven by land modification with the consequences for ecosystem function. Yet, most studies have been small-scale, experimental analyses and primarily focussed on plants. There is a lack of research on fauna communities and at large-scales across multiple land uses. We assessed changes in the functional diversity of bird communities across 24 land uses aligned along an intensification gradient. We tested the hypothesis that functional diversity is higher in less intensively used landscapes, documented changes in diversity using four diversity metrics, and examined how functional diversity varied with species richness to identify levels of functional redundancy. Functional diversity, measured using a dendogram-based metric, increased from high to low intensity land uses, but observed values did not differ significantly from randomly-generated expected values. Values for functional evenness and functional divergence did not vary consistently with land-use intensification, although higher than expected values were mostly recorded in high intensity land uses. A total of 16 land uses had lower than expected values for functional dispersion and these were mostly low intensity native vegetation sites. Relations between functional diversity and bird species richness yielded strikingly different patterns for the entire bird community vs. particular functional groups. For all birds and insectivores, functional evenness, divergence and dispersion showed a linear decline with increasing species richness suggesting substantial functional redundancy across communities. However, for nectarivores, frugivores and carnivores, there was a significant hump-shaped or non-significant positive linear relationship between these functional measures and species richness indicating less redundancy. Hump-shaped relationships signify that the most functionally diverse

  11. Síndrome da redundância das raízes lombares: relato de um caso

    Directory of Open Access Journals (Sweden)

    José Carlos Lynch

    1985-06-01

    Full Text Available Um homem de 64 anos apresentava dor ciática crônica. A mielografia revelou compressão extradural e tortuosidade das raízes lombares. Foi verificado tratar-se da síndrome da redundância das raízes lombares. Laminectomia e facetectomia foram realizadas com acentuada melhora dos sintomas no pós-operatório.

  12. Changes in bird functional diversity across multiple land uses: interpretations of functional redundancy depend on functional group identity.

    Directory of Open Access Journals (Sweden)

    Gary W Luck

    Full Text Available Examinations of the impact of land-use change on functional diversity link changes in ecological community structure driven by land modification with the consequences for ecosystem function. Yet, most studies have been small-scale, experimental analyses and primarily focussed on plants. There is a lack of research on fauna communities and at large-scales across multiple land uses. We assessed changes in the functional diversity of bird communities across 24 land uses aligned along an intensification gradient. We tested the hypothesis that functional diversity is higher in less intensively used landscapes, documented changes in diversity using four diversity metrics, and examined how functional diversity varied with species richness to identify levels of functional redundancy. Functional diversity, measured using a dendogram-based metric, increased from high to low intensity land uses, but observed values did not differ significantly from randomly-generated expected values. Values for functional evenness and functional divergence did not vary consistently with land-use intensification, although higher than expected values were mostly recorded in high intensity land uses. A total of 16 land uses had lower than expected values for functional dispersion and these were mostly low intensity native vegetation sites. Relations between functional diversity and bird species richness yielded strikingly different patterns for the entire bird community vs. particular functional groups. For all birds and insectivores, functional evenness, divergence and dispersion showed a linear decline with increasing species richness suggesting substantial functional redundancy across communities. However, for nectarivores, frugivores and carnivores, there was a significant hump-shaped or non-significant positive linear relationship between these functional measures and species richness indicating less redundancy. Hump-shaped relationships signify that the most

  13. 25 CFR 700.33 - Act (The Act).

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Act (The Act). 700.33 Section 700.33 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.33 Act (The Act). (a) The Act. The Act is Pub. L. 93-531, (88 Stat...

  14. A framework for quantification of groundwater dynamics - redundancy and transferability of hydro(geo-)logical metrics

    Science.gov (United States)

    Heudorfer, Benedikt; Haaf, Ezra; Barthel, Roland; Stahl, Kerstin

    2017-04-01

    A new framework for quantification of groundwater dynamics has been proposed in a companion study (Haaf et al., 2017). In this framework, a number of conceptual aspects of dynamics, such as seasonality, regularity, flashiness or inter-annual forcing, are described, which are then linked to quantitative metrics. Hereby, a large number of possible metrics are readily available from literature, such as Pardé Coefficients, Colwell's Predictability Indices or Base Flow Index. In the present work, we focus on finding multicollinearity and in consequence redundancy among the metrics representing different patterns of dynamics found in groundwater hydrographs. This is done also to verify the categories of dynamics aspects suggested by Haaf et al., 2017. To determine the optimal set of metrics we need to balance the desired minimum number of metrics and the desired maximum descriptive property of the metrics. To do this, a substantial number of candidate metrics are applied to a diverse set of groundwater hydrographs from France, Germany and Austria within the northern alpine and peri-alpine region. By applying Principle Component Analysis (PCA) to the correlation matrix of the metrics, we determine a limited number of relevant metrics that describe the majority of variation in the dataset. The resulting reduced set of metrics comprise an optimized set that can be used to describe the aspects of dynamics that were identified within the groundwater dynamics framework. For some aspects of dynamics a single significant metric could be attributed. Other aspects have a more fuzzy quality that can only be described by an ensemble of metrics and are re-evaluated. The PCA is furthermore applied to groups of groundwater hydrographs containing regimes of similar behaviour in order to explore transferability when applying the metric-based characterization framework to groups of hydrographs from diverse groundwater systems. In conclusion, we identify an optimal number of metrics

  15. Using min-max of torque to resolve redundancy for a mobile manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.

    1993-11-01

    We have considered the problem of determining the time trajectories of the joint variables of a mobile manipulator with many redundant degrees of freedom that will minimize the maximum value of the torque during a large scale motion by the manipulator. To create a well defined problem, we will divide the problem into two components: path planner and surveyor. The path planner will choose a path (between two points in Cartesian space) that will minimize the maximum value of the torque along the path. The input to the path planner is a network of path segments with the maximum value of the torque on each segment. The surveyor will find the points in joint space that are local minimums for the maximum value of the torque at each Cartesian position and define the network of path segments. In this paper, our focus will be on the surveyor and not on the path planner. Our min-max problem has an extra constraint on the joint variables. We seek a min-max at each Cartesian position rather than a global min-max. We have used the Kuhn-Tucker conditions to derive necessary conditions for the solution of our min-max problem. We find that the necessary conditions require that at one or more of the joints the magnitude of the normalized torques will be equal to the min-max value. We have explored the torque surfaces for two mobile manipulators: a planar manipulator and the CESARm. The CESARm is a manipulator with three joint angles controlling the height of the arm. The paths with three equal torques have low values for the torque but they only cover part of the workspace and do not join together. Paths with two equal torques cover the workspace and bridge between the disjoint path segments. We have evaluated the necessary conditions for both the paths with three equal torques and the paths with two equal torques. In most cases, the paths satisfy the necessary conditions.

  16. Novel reaction control techniques for redundant space manipulators: Theory and simulated microgravity tests

    Science.gov (United States)

    Cocuzza, Silvio; Pretto, Isacco; Debei, Stefano

    2011-06-01

    This paper presents two novel redundancy resolution schemes aimed at locally minimizing the reaction torque transferred to the spacecraft during manipulator manoeuvres. The subject is of particular interest in space robotics because reduced reactions result in reduced energy consumption and longer operating life of the attitude control system. The first presented solution is based on a weighted Jacobian pseudoinverse and is derived by using Lagrangian multipliers. The weight matrix is defined by means of the inertia matrix which appears in the spacecraft reaction torque dynamics. The second one is based on a least squares formulation of the minimization problem. In this formulation the linearity of the forward kinematics and of the reaction torque dynamics equations with respect to the joint accelerations is used. A closed-form solution is derived for both the presented methods, and their equivalence is proven analytically. Moreover, the proposed solutions, which are suitable for real-time implementation, are extended in order to take into account the physical limits of the manipulator joints directly inside the solution algorithms. A software simulator has been developed in order to simulate the performance of the presented solutions for the selected test cases. The proposed solutions have then been experimentally tested using a 3D free-flying robot previously tested in an ESA parabolic flight campaign. In the test campaign the 3D robot has been converted in a 2D robot thanks to its modularity in order to perform planar tests, in which the microgravity environment can be simulated without time constraints. Air-bearings are used to sustain the links weight, and a dynamometer is used to measure the reaction torque. The experimental validation of the presented inverse kinematics solutions, with an insight on the effect of joint flexibility on their performance, has been carried out, and the experimental results confirmed the good performance of the proposed methods

  17. The Child Justice Act

    African Journals Online (AJOL)

    Stephan

    1995-06-16

    Jun 16, 1995 ... I want to express my gratitude to them all. 1 In the past a few different categories of young offenders were specifically addressed in our law. For example, s 290 of the Criminal Procedure Act 51 of 1977 (before its repeal by the Child. Justice Act 75 of 2008) had specific provisions for "young offenders" under ...

  18. ACT and College Success

    Science.gov (United States)

    Bleyaert, Barbara

    2010-01-01

    What is the relationship between ACT scores and success in college? For decades, admissions policies in colleges and universities across the country have required applicants to submit scores from a college entrance exam, most typically the ACT (American College Testing) or SAT (Scholastic Aptitude Test). This requirement suggests that high school…

  19. Marine Mammal Protection Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Mammal Protection Act (MMPA or Act) prohibits, with certain exceptions, the "take" of marine mammals in U.S. waters and by U.S. citizens on the high seas,...

  20. Transitions as Speech Acts.

    Science.gov (United States)

    Fesmire, Alice Ann

    1993-01-01

    Reviews speech act theory to explain the function of writing transitions in terms of the illocutionary and perlocutionary effect of explicit performatives. Identifies explicit performatives in samples of professional writing in technical and academic areas. Suggest ways to revise textbooks to include the findings from speech act theory. (SR)

  1. Acts of kindness and acts of novelty affect life satisfaction.

    Science.gov (United States)

    Buchanan, Kathryn E; Bardi, Anat

    2010-01-01

    The present experiment was designed to establish the effects of acts of kindness and acts of novelty on life satisfaction. Participants aged 18-60 took part on a voluntary basis. They were randomly assigned to perform either acts of kindness, acts of novelty, or no acts on a daily basis for 10 days. Their life satisfaction was measured before and after the 10-day experiment. As expected, performing acts of kindness or acts of novelty resulted in an increase in life satisfaction.

  2. Dual Roles of O-Glucose Glycans Redundant with Monosaccharide O-Fucose on Notch in Notch Trafficking.

    Science.gov (United States)

    Matsumoto, Kenjiroo; Ayukawa, Tomonori; Ishio, Akira; Sasamura, Takeshi; Yamakawa, Tomoko; Matsuno, Kenji

    2016-06-24

    Notch is a transmembrane receptor that mediates cell-cell interactions and controls various cell-fate specifications in metazoans. The extracellular domain of Notch contains multiple epidermal growth factor (EGF)-like repeats. At least five different glycans are found in distinct sites within these EGF-like repeats. The function of these individual glycans in Notch signaling has been investigated, primarily by disrupting their individual glycosyltransferases. However, we are just beginning to understand the potential functional interactions between these glycans. Monosaccharide O-fucose and O-glucose trisaccharide (O-glucose-xylose-xylose) are added to many of the Notch EGF-like repeats. In Drosophila, Shams adds a xylose specifically to the monosaccharide O-glucose. We found that loss of the terminal dixylose of O-glucose-linked saccharides had little effect on Notch signaling. However, our analyses of double mutants of shams and other genes required for glycan modifications revealed that both the monosaccharide O-glucose and the terminal dixylose of O-glucose-linked saccharides function redundantly with the monosaccharide O-fucose in Notch activation and trafficking. The terminal dixylose of O-glucose-linked saccharides and the monosaccharide O-glucose were required in distinct Notch trafficking processes: Notch transport from the apical plasma membrane to adherens junctions, and Notch export from the endoplasmic reticulum, respectively. Therefore, the monosaccharide O-glucose and terminal dixylose of O-glucose-linked saccharides have distinct activities in Notch trafficking, although a loss of these activities is compensated for by the presence of monosaccharide O-fucose. Given that various glycans attached to a protein motif may have redundant functions, our results suggest that these potential redundancies may lead to a serious underestimation of glycan functions. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Dual Roles of O-Glucose Glycans Redundant with Monosaccharide O-Fucose on Notch in Notch Trafficking*

    Science.gov (United States)

    Matsumoto, Kenjiroo; Ayukawa, Tomonori; Ishio, Akira; Sasamura, Takeshi; Yamakawa, Tomoko; Matsuno, Kenji

    2016-01-01

    Notch is a transmembrane receptor that mediates cell-cell interactions and controls various cell-fate specifications in metazoans. The extracellular domain of Notch contains multiple epidermal growth factor (EGF)-like repeats. At least five different glycans are found in distinct sites within these EGF-like repeats. The function of these individual glycans in Notch signaling has been investigated, primarily by disrupting their individual glycosyltransferases. However, we are just beginning to understand the potential functional interactions between these glycans. Monosaccharide O-fucose and O-glucose trisaccharide (O-glucose-xylose-xylose) are added to many of the Notch EGF-like repeats. In Drosophila, Shams adds a xylose specifically to the monosaccharide O-glucose. We found that loss of the terminal dixylose of O-glucose-linked saccharides had little effect on Notch signaling. However, our analyses of double mutants of shams and other genes required for glycan modifications revealed that both the monosaccharide O-glucose and the terminal dixylose of O-glucose-linked saccharides function redundantly with the monosaccharide O-fucose in Notch activation and trafficking. The terminal dixylose of O-glucose-linked saccharides and the monosaccharide O-glucose were required in distinct Notch trafficking processes: Notch transport from the apical plasma membrane to adherens junctions, and Notch export from the endoplasmic reticulum, respectively. Therefore, the monosaccharide O-glucose and terminal dixylose of O-glucose-linked saccharides have distinct activities in Notch trafficking, although a loss of these activities is compensated for by the presence of monosaccharide O-fucose. Given that various glycans attached to a protein motif may have redundant functions, our results suggest that these potential redundancies may lead to a serious underestimation of glycan functions. PMID:27129198

  4. Divergence and redundancy in CSLD2 and CSLD3 function during Arabidopsis thaliana root hair and female gametophyte development

    Directory of Open Access Journals (Sweden)

    Cheol-Min eYoo

    2012-05-01

    Full Text Available The Arabidopsis cellulose synthase-like D (CSLD 2 and 3 genes are known to function in root hair development. Here, we show that these genes also play a role in female gametophyte development because csld2 csld3 double mutants were observed to have low seed set that could be traced to defects in female transmission efficiency. Cell biological studies of csld2 csld3 ovules showed premature synergid cell degeneration during megagametogenesis and reduced pollen tube penetration during fertilization. Although CSLD2 and CSLD3 function redundantly in female gametophyte development, detailed analyses of root hair phenotypes of progeny from genetic crosses between csld2 and csld3, suggest that CSLD3 might play a more prominent role than CSLD2 in root hair development. Phylogenetic and gene duplication studies of CSLD2 and CSLD3 homologs in Populus, rice, Physcomitrella and Selaginella were performed to better understand the partial redundancy and divergence of these two genes. Our results indicate that the ancestor of land plants contained only two copies of CSLDs, one of which developed into the CSLD5 lineage in flowering plants, and the other formed the CSLD1/2/3/4 clade. In addition, CSLD2 and CSLD3 likely originated from a recent genome-wide duplication event explaining their redundancy. Moreover, sliding-window dN/dS analysis showed that most of the coding regions of CSLD2 and CSLD3 have been under strong purifying selection pressure. However, the region that encodes the N-terminus of CSLD3 has been under relatively relaxed selection pressure as indicated by its high dN/dS value, suggesting that CSLD3 might have gained additional functions through more frequent non-synonymous sequence changes at the N-terminus. which could partly explain the more prominent role of CSLD3 during root hair development compared to CSLD2.

  5. Recessive antimorphic alleles overcome functionally redundant loci to reveal TSO1 function in Arabidopsis flowers and meristems.

    Directory of Open Access Journals (Sweden)

    Paja Sijacic

    2011-11-01

    Full Text Available Arabidopsis TSO1 encodes a protein with conserved CXC domains known to bind DNA and is homologous to animal proteins that function in chromatin complexes. tso1 mutants fall into two classes due to their distinct phenotypes. Class I, represented by two different missense mutations in the CXC domain, leads to failure in floral organ development, sterility, and fasciated inflorescence meristems. Class II, represented by a nonsense mutation and a T-DNA insertion line, develops wild-type-like flowers and inflorescences but shows severely reduced fertility. The phenotypic variability of tso1 alleles presents challenges in determining the true function of TSO1. In this study, we use artificial microRNA, double mutant analysis, and bimolecular fluorescence complementation assay to investigate the molecular basis underlying these two distinct classes of phenotypes. We show that the class I mutants could be converted into class II by artificial microRNA knockdown of the tso1 mutant transcript, suggesting that class I alleles produce antimorphic mutant proteins that interfere with functionally redundant loci. We identified one such redundant factor coded by the closely related TSO1 homolog SOL2. We show that the class I phenotype can be mimicked by knocking out both TSO1 and its homolog SOL2 in double mutants. Such antimorphic alleles targeting redundant factors are likely prevalent in Arabidopsis and maybe common in organisms with many sets of paralogous genes such as human. Our data challenge the conventional view that recessive alleles are always hypomorphic or null and that antimorphic alleles are always dominant. This study shows that recessive alleles can also be antimorphic and can produce a phenotype more severe than null by interfering with the function of related loci. This finding adds a new paradigm to classical genetic concepts, with important implications for future genetic studies both in basic research as well as in agriculture and medicine.

  6. Fault detection and isolation of PEM fuel cell system based on nonlinear analytical redundancy. An application via parity space approach

    Science.gov (United States)

    Aitouche, A.; Yang, Q.; Ould Bouamama, B.

    2011-05-01

    This paper presents a procedure dealing with the issue of fault detection and isolation (FDI) using nonlinear analytical redundancy (NLAR) technique applied in a proton exchange membrane (PEM) fuel cell system based on its mathematic model. The model is proposed and simplified into a five orders state space representation. The transient phenomena captured in the model include the compressor dynamics, the flow characteristics, mass and energy conservation and manifold fluidic mechanics. Nonlinear analytical residuals are generated based on the elimination of the unknown variables of the system by an extended parity space approach to detect and isolate actuator and sensor faults. Finally, numerical simulation results are given corresponding to a faults signature matrix.

  7. Draconian dress act repealed.

    Science.gov (United States)

    Mhone, C

    1994-01-01

    The Dress Act was put into place in Malawi by the government of President Kamuzu Banda after the long period of direct colonialism. The act made it illegal for women in Malawi to be seen publicly wearing dresses which did not completely cover their knees or wearing pants; men had to wear their hair short. Police officers even scrutinized women's attire at private house parties and in homes. The autocratic political structure established by Banda, however, was voted out in a referendum June 14, 1993. Pressure by opposition forces such as the United Democratic Front forced a repeal of the act on November 16 of the same year. The repeal was vigorously attacked by female Parliament members as a move which would result in moral degradation and an increase in the level of sexual harassment against women. Other citizens and tourists have generally detested the act. The act has most certainly kept many potential visitors from vacationing in Malawi. Some expert observers think that repeals of the Dress Act, the Forfeiture Act, and legislation which allowed the government to detain opposition figures without trial were done to garner support from the Paris Club for the resumption of balance of payments support suspended due to the country's poor human rights record.

  8. Sarbanes Oxley Act

    OpenAIRE

    Těšínský, Josef

    2011-01-01

    The diploma thesis is focused on corporate fraud problematic, on The Sarbanes-Oxley Act of 2002 and on problematics of internal control systems and corporate governance, which relate closely with the Sarbanes-Oxley act. The goal of my diploma thesis is to highlight the significance of corporate fraud problematic and create an integrated summary of requirements placed on companies, which either have to or want to comply with the Sarbanes-Oxley act. The opening part of the diploma thesis is foc...

  9. The Experiment as Act

    DEFF Research Database (Denmark)

    Søndergaard, Morten

    to identify and locate the experiments of POEX65 as acts; and to ask the questions: what constitutes those acts as experiments? and how do we possibly archive them? My purpose, then, is to define the methodologies to obtain the contours of a post-phenomenology of experimental artistic production in order...... to be able to analyse the phenomena found at POEX65. Here I will use the notion of the ‘ontological theatre’ (Pickering), which, according to Pickering, is acted out in experimental art productions. The experiment could thus be seen as an ‘agency-realism’ – as an ‘act’ of relations across the aesthetics...

  10. 75 FR 63703 - Privacy Act of 1974; Privacy Act Regulation

    Science.gov (United States)

    2010-10-18

    ... CFR Part 261a Privacy Act of 1974; Privacy Act Regulation AGENCY: Board of Governors of the Federal...) is issuing a final rule to amend its regulation implementing the Privacy Act of 1974 (Privacy Act..., and applicants for Board employment, for access to their records under the Privacy Act; the amendment...

  11. Energy Policy Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Energy Policy Act (EPA) addresses energy production in the United States, including: (1) energy efficiency; (2) renewable energy; (3) oil and gas; (4) coal; (5)...

  12. Clean Water Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Clean Water Act (CWA) establishes the basic structure for regulating discharges of pollutants into U.S. waters and regulating quality standards for surface...

  13. Affordable Care Act (ACA)

    Data.gov (United States)

    Social Security Administration — The Affordable Care Act (ACA) is a federal statute enacted with a goal of increasing the quality and affordability of health insurance. Through a web service, CMS...

  14. Endangered Species Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of the Endangered Species Act (ESA) is to protect and recover imperiled species and the ecosystems upon which they depend. The U.S. Fish and Wildlife...

  15. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... CYSTIC FIBROSIS Learn about cystic fibrosis, a genetic lung disorder that affects the pancreas and other organs, ... Clearance Techniques (ACTs) Autogenic Drainage (AD) Basics of Lung Care Chest Physical Therapy Coughing and Huffing High- ...

  16. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... resources you need to continuously build upon this work. Awards and Grants Career Development Awards Research Awards ... The Preserving Employee Wellness Programs Act Our Advocacy Work Advocacy Achievements Advocacy News Briefings, Testimonies, and Regulatory ...

  17. Abandoned Shipwreck Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Abandoned Shipwreck Act of 1987 (ASA) affirms the authority of state governments to claim ownership to, protect, and manage abandoned shipwrecks on state...

  18. Act250 Permits

    Data.gov (United States)

    Vermont Center for Geographic Information — The dataset includes the geographic location for Act 250 permits issued since the inception of the law in 1970. Base permit numbers only are included; permit...

  19. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... Team Your cystic fibrosis care team includes a group of CF health care professionals who partner with ... Airway Clearance Airway Clearance Techniques (ACTs) There are different ways to clear your airways. Most are easy ...

  20. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... Twitter YouTube Instagram Email DONATE Breadcrumb Navigation Home Life With CF Treatments and Therapies Airway Clearance Airway Clearance Techniques (ACTs) There are different ways to clear your airways. Most are easy to ...

  1. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... Airway Clearance Airway Clearance Techniques (ACTs) There are different ways to clear your airways. Most are easy ... to loosen mucus from airway walls. See how different airway clearance techniques work to help you clear ...

  2. DREAM Act, Part II

    National Research Council Canada - National Science Library

    Miranda, María Eugenia

    2011-01-01

    .... For nearly a decade Congress has failed to pass a bill - the Development Relief and Education for Alien Minors Act - that would grant AJulema legal residence and free her from a life in the shadows...

  3. Clean Water Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent geographic terms used within the Clean Water Act (CWA). The CWA establishes the basic structure for regulating the addition of pollutants...

  4. ACT250 Districts

    Data.gov (United States)

    Vermont Center for Geographic Information — The ACT 250 Districts layer is part of a larger dataset that contains administrative boundaries for Vermont's Agency of Natural Resources. The dataset includes...

  5. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... What to Consider Regarding a Lung Transplant Medications Antibiotics Bronchodilators Mucus Thinners Nebulizer Care at Home Vascular ... that help thin and move the mucus, and antibiotics. Bronchodilators should be inhaled before you start ACTs. ...

  6. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... an eCard Submit Your Artwork Honor a Loved One Create a Tribute Page Find a Tribute Page ... to try. However, the best ACT is the one that you are most likely to perform as ...

  7. Acts of Research

    DEFF Research Database (Denmark)

    Nelund, Sidsel

    described as knowledge producers and exhibitions and art works as instances of knowledge production. Acts of Research: Knowledge Production in Contemporary Arts between Knowledge Economy and Critical Practices analyses this development. The academic discussion of knowledge production in the arts has taken...... place mostly in seminars and articles, in which knowledge is often discussed as an intrinsic quality of the artwork. Acts of Research, however, is devoted to studying the rise of knowledge production in contemporary art from the perspective of artistic, curatorial and educational research...... with an awareness of larger political, economic, geographical and art-related aspects. The concept of ‘acts of research’ is suggested as a way to understand knowledge production as a creative act in which research carried out in relation to a specific material challenges and resists the protocols of conventional...

  8. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... NACFC Carolyn and C. Richard Mattingly Leadership in Mental Health Care Award Mary M. Kontos Award NACFC ... you clear the thick, sticky mucus from your lungs. ACTs are often used with other treatments, including ...

  9. Marine Pollution Prevention Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Pollution Prevention Act of 2008 implements the International Convention for the Prevention of Pollution from Ships, including related Protocols (MARPOL)...

  10. National Environmental Policy Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Environmental Policy Act (NEPA) was the first major environmental law in the United States and established national environmental policies for the...

  11. Seed dispersal services by coatis ( Nasua nasua, Procyonidae) and their redundancy with other frugivores in southeastern Brazil

    Science.gov (United States)

    Alves-Costa, Cecília P.; Eterovick, Paula C.

    2007-07-01

    oati effectiveness as seed dispersers and their potential in maintaining this service through an annual cycle were evaluated during 33 months in an Atlantic forest fragment in southeastern Brazil. We determined the range of fruit and seed traits consumed by coatis, the phenology of fruit consumption, the patterns of fruit consumption and seed defecation, and the effects of ingestion in the speed and success of seed germination. In addition, we assessed redundancy among the seed dispersal services provided by coatis and other resident frugivores. Coatis consumed fruits of 53 species and dispersed seeds of at least 49 out of these species. Most consumed plant species were pioneer (59%), had fruits >15 mm diameter (58%), and were yellow or green (54%). Seeds were found in 54.5% out of 288 faecal samples. The number of seeds in faeces correlated negatively to seed mass and ranged from 1 to 1209 seeds; 50% of the faeces had <50 seeds. Passage through coatis gut did not alter speed or success of seed germination of tested species, except for Myrcia guajavaefolia, whose germination success was increased approximately 50% after pulp removal by coatis. Considering fruit colour and seed size, redundancy of seed dispersal services between coatis and other frugivores ranged from 39 to 70%. In defaunated fragments, coatis may provide a 'key role' in maintaining seed dispersal services for a large variety of species and they may promote gene flow among forest patches and the regeneration of disturbed sites.

  12. DORNRÖSCHEN, DORNRÖSCHEN-LIKE, and PUCHI redundantly control floral meristem identity and organ initiation in Arabidopsis.

    Science.gov (United States)

    Chandler, J W; Werr, W

    2017-06-15

    The biphasic floral transition in Arabidopsis thaliana involves many redundant intersecting regulatory networks. The related AP2 transcription factors DORNRÖSCHEN (DRN), DORNRÖSCHEN-LIKE (DRNL), and PUCHI individually execute well-characterized functions in diverse developmental contexts, including floral development. Here, we show that their combined loss of function leads to synergistic floral phenotypes, including reduced floral merosity in all whorls, which reflects redundant functions of all three genes in organ initiation rather than outgrowth. Additional loss of BLADE-ON-PETIOLE1 (BOP1) and BOP2 functions results in the complete conversion of floral meristems into secondary inflorescence shoots, demonstrating that all five genes define an essential regulatory network for establishing floral meristem identity, and we show that their functions converge to regulate LEAFY expression. Thus, despite their largely discrete spatiotemporal expression domains in the inflorescence meristem and early floral meristem, PUCHI, DRN, and DRNL interdependently contribute to cellular fate decisions. Auxin might represent one potential non-cell-autonomous mediator of their gene functions, because PUCHI, DRN, and DRNL all interact with auxin transport and biosynthesis pathways. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Rigid-flexible coupling dynamic modeling and investigation of a redundantly actuated parallel manipulator with multiple actuation modes

    Science.gov (United States)

    Liang, Dong; Song, Yimin; Sun, Tao; Jin, Xueying

    2017-09-01

    A systematic dynamic modeling methodology is presented to develop the rigid-flexible coupling dynamic model (RFDM) of an emerging flexible parallel manipulator with multiple actuation modes. By virtue of assumed mode method, the general dynamic model of an arbitrary flexible body with any number of lumped parameters is derived in an explicit closed form, which possesses the modular characteristic. Then the completely dynamic model of system is formulated based on the flexible multi-body dynamics (FMD) theory and the augmented Lagrangian multipliers method. An approach of combining the Udwadia-Kalaba formulation with the hybrid TR-BDF2 numerical algorithm is proposed to address the nonlinear RFDM. Two simulation cases are performed to investigate the dynamic performance of the manipulator with different actuation modes. The results indicate that the redundant actuation modes can effectively attenuate vibration and guarantee higher dynamic performance compared to the traditional non-redundant actuation modes. Finally, a virtual prototype model is developed to demonstrate the validity of the presented RFDM. The systematic methodology proposed in this study can be conveniently extended for the dynamic modeling and controller design of other planar flexible parallel manipulators, especially the emerging ones with multiple actuation modes.

  14. Inside the mind of poor Tom--A multidimensional approach to determine causes for redundant clothing in patients with schizophrenia.

    Science.gov (United States)

    Mahintamani, Tathagata; Ram, Daya; Mitra, Sayantanava

    2015-06-30

    Redundant clothing (RC) is a readily observable feature of schizophrenia. While abnormal thermoregulation, thyroid dysfunction and autonomic dysregulation have been postulated to account for RC, no identified factor yet conclusively explains this enigmatic behaviour. This study attempted to determine the cause(s) of RC in schizophrenia. Two groups of 20 age- and sex-matched patients with and without RC were studied. Socio-demographic and clinical characteristics were recorded, and patients were assessed for psychopathology (Positive and Negative Syndrome Scale (PANSS)), cognitive function (Schizophrenia Cognition Rating Scale (SCoRS)), and autonomic and thyroid function. Those with RC differed significantly from those without RC in education, occupation, marital status and duration of untreated psychosis (DUP). They were more disorganised, more withdrawn, and had significant affective impairment. The RC group also had significantly higher negative, general and total psychopathology scores on the Positive and Negative Syndrome Scale, significantly poorer cognitive function, greater autonomic dysfunction, and lower free T3 and free T4 concentrations. We propose that the dimension of RC could define a subgroup with poorer premorbid functioning and a longer DUP, in whom cognitive dysfunction and prominent negative symptoms coloured the manifestations of deranged thermoregulation secondary to lower thyroid hormone levels and autonomic dysfunction, ultimately resulting in redundant clothing. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Learning a motor task involving obstacles by a multi-joint, redundant limb: two synergies within one movement.

    Science.gov (United States)

    Jaric, S; Latash, M L

    1998-06-01

    In this study, we investigated the hypothesis that the problem of motor redundancy could be solved using synergies representing rules for relative joint involvement to ensure a desired endpoint trajectory which may be context-dependent and may change with practice. Subjects practised a planar movement 'as fast as possible' from an initial to a final position, avoiding three round obstacles. The improvement in motor performance included a decrease in movement time and in the error scores. It was accompanied by the emergence of two distinct synergies. The first one involved elbow and shoulder movements and was used to move from the initial position to the first obstacle, and from obstacle to obstacle, whereas the second, involving the wrist, was used while going around the obstacles. The first synergy was seen before practice and showed an increase in joint coupling with practice. The second synergy was not seen prior to practice; it could not be explained by the pseudo-inverse transformation. We concluded that the central nervous system (CNS) has options for solving the redundancy problem, and that the solutions may be chosen based on such considerations as accuracy requirements, inertial properties of segments, and efficacy of particular joints to move the endpoint along a desired trajectory.

  16. Low functional richness and redundancy of a predator assemblage in native forest fragments of Chiloe island, Chile.

    Science.gov (United States)

    Farias, Ariel A; Jaksic, Fabian M

    2011-07-01

    1. Changes in land use and habitat fragmentation are major drivers of global change, and studying their effects on biodiversity constitutes a major research programme. However, biodiversity is a multifaceted concept, with a functional component linking species richness to ecosystem function. Currently, the interaction between functional and taxonomic components of biodiversity under realistic scenarios of habitat degradation is poorly understood. 2. The expected functional richness (FR)-species richness relationship (FRSR) is positive, and attenuated for functional redundancy in species-rich assemblages. Further, environmental filters are expected to flatten that association by sorting species with similar traits. Thus, analysing FRSR can inform about the response of biodiversity to environmental gradients and habitat fragmentation, and its expected functional consequences. 3. Top predators affect ecosystem functioning through prey consumption and are particularly vulnerable to changes in land use and habitat fragmentation, being good indicators of ecosystem health and suitable models for assessing the effects of habitat fragmentation on their FR. 4. Thus, this study analyses the functional redundancy of a vertebrate predator assemblage at temperate forest fragments in a rural landscape of Chiloe island (Chile), testing the existence of environmental filters by contrasting an empirically derived FRSR against those predicted from null models, and testing the association between biodiversity components and the structure of forest fragments. 5. Overall, contrasts against null models indicate that regional factors determine low levels of FR and redundancy for the vertebrate predator assemblage studied, while recorded linear FRSR indicates proportional responses of the two biodiversity components to the structure of forest fragments. Further, most species were positively associated with either fragment size or shape complexity, which are highly correlated. This, and the

  17. Inverse kinematics of redundant systems driver IKORv1.0-2.0 (full space parameterization with orientation control, platform mobility, and portability)

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, C.J.; Fries, G.A.; Pin, F.G.

    1997-01-01

    Few optimization methods exist for path planning of kinematically redundant manipulators. Among these, a universal method is lacking that takes advantage of a manipulator`s redundancy while satisfying possibly varying constraints and task requirements. Full Space Parameterization (FSP) is a new method that generates the entire solution space of underspecified systems of algebraic equations and then calculates the unique solution satisfying specific constraints and optimization criteria. The FSP method has been previously tested on several configurations of the redundant manipulator HERMIES-III. This report deals with the extension of the FSP driver, Inverse Kinematics On Redundant systems (IKOR), to include three-dimensional manipulation systems, possibly incorporating a mobile platform, with and without orientation control. The driver was also extended by integrating two optimized versions of the FSP solution generator as well as the ability to easily port to any manipulator. IKOR was first altered to include the ability to handle orientation control and to integrate an optimized solution generator. The resulting system was tested on a 4 degrees-of-redundancy manipulator arm and was found to successfully perform trajectories with least norm criteria while avoiding obstacles and joint limits. Next, the system was adapted and tested on a manipulator arm placed on a mobile platform yielding 7 degrees of redundancy. After successful testing on least norm trajectories while avoiding obstacles and joint limits, IKORv1.0 was developed. The system was successfully verified using comparisons with a current industry standard, the Moore Penrose Pseudo-Inverse. Finally, IKORv2.0 was created, which includes both the one shot and two step methods, manipulator portability, integration of a second optimized solution generator, and finally a more robust and usable code design.

  18. Formal Verification of an Iterative Low-Power x86 Floating-Point Multiplier with Redundant Feedback

    Directory of Open Access Journals (Sweden)

    Peter-Michael Seidel

    2011-10-01

    Full Text Available We present the formal verification of a low-power x86 floating-point multiplier. The multiplier operates iteratively and feeds back intermediate results in redundant representation. It supports x87 and SSE instructions in various precisions and can block the issuing of new instructions. The design has been optimized for low-power operation and has not been constrained by the formal verification effort. Additional improvements for the implementation were identified through formal verification. The formal verification of the design also incorporates the implementation of clock-gating and control logic. The core of the verification effort was based on ACL2 theorem proving. Additionally, model checking has been used to verify some properties of the floating-point scheduler that are relevant for the correct operation of the unit.

  19. A reliable dual-redundant sensor FDI system for the NASA F8C-DFBW aircraft

    Science.gov (United States)

    Deckert, J. C.; Desai, M. N.; Deyst, J. J., Jr.; Willsky, A. S.

    1976-01-01

    In this paper we outline the structure of a sensor failure detection and identification (FDI) system designed for the NASA F8C DFBW aircraft. The system is for use in a dual-redundant environment, and it takes maximal advantage of all functional and kinematic relationships among the sensed variables. The technique is reliable in that we have designed the system to account for a variety of unmodeled effects and have introduced a new concept - the quality sequential probability ratio (QSPR) - that provides a useful measure of our confidence in each test. The methodology used for determining detector parameters and the 'outer loop logic' for combining the various sources of information are described.

  20. S. aureus hemolysins, bi-component leukocidins and cytolytic peptides: a redundant arsenal of membrane-damaging virulence factors?

    Directory of Open Access Journals (Sweden)

    Francois eVandenesch

    2012-02-01

    Full Text Available One key aspect of S. aureus virulence lies in its ability to target the host cell membrane with a large number of membrane-damaging toxins and peptides. In this review, we describe the hemolysins, the bi-component leukocidins, which include the Panton Valentine Leukocidin, LukAB/GH, LukED and the cytolytic peptides (Phenol Soluble Modulins. While at first glance, all these factors might appear redundant, it is now clear that some of these factors play specific roles in certain S. aureus life stages and diseases or target specific cell types or species. Here, we present an update of the literature on toxins receptors and their cell type and species specificities. Furthermore, we review epidemiological studies and animal models illustrating a role of these membrane-damaging factors in various diseases. Finally, we emphasize the interplay of these factors with the host immune system and highlight all their non-lytic functions.