WorldWideScience

Sample records for account positioning errors

  1. Determination of drill paths for percutaneous cochlear access accounting for target positioning error

    Science.gov (United States)

    Noble, Jack H.; Warren, Frank M.; Labadie, Robert F.; Dawant, Benoit; Fitzpatrick, J. Michael

    2007-03-01

    In cochlear implant surgery an electrode array is permanently implanted to stimulate the auditory nerve and allow deaf people to hear. Current surgical techniques require wide excavation of the mastoid region of the temporal bone and one to three hours time to avoid damage to vital structures. Recently a far less invasive approach has been proposed-percutaneous cochlear access, in which a single hole is drilled from skull surface to the cochlea. The drill path is determined by attaching a fiducial system to the patient's skull and then choosing, on a pre-operative CT, an entry point and a target point. The drill is advanced to the target, the electrodes placed through the hole, and a stimulator implanted at the surface of the skull. The major challenge is the determination of a safe and effective drill path, which with high probability avoids specific vital structures-the facial nerve, the ossicles, and the external ear canal-and arrives at the basal turn of the cochlea. These four features lie within a few millimeters of each other, the drill is one millimeter in diameter, and errors in the determination of the target position are on the order of 0.5mm root-mean square. Thus, path selection is both difficult and critical to the success of the surgery. This paper presents a method for finding optimally safe and effective paths while accounting for target positioning error.

  2. Time-integrated position error accounts for sensorimotor behavior in time-constrained tasks.

    Directory of Open Access Journals (Sweden)

    Julian J Tramper

    Full Text Available Several studies have shown that human motor behavior can be successfully described using optimal control theory, which describes behavior by optimizing the trade-off between the subject's effort and performance. This approach predicts that subjects reach the goal exactly at the final time. However, another strategy might be that subjects try to reach the target position well before the final time to avoid the risk of missing the target. To test this, we have investigated whether minimizing the control effort and maximizing the performance is sufficient to describe human motor behavior in time-constrained motor tasks. In addition to the standard model, we postulate a new model which includes an additional cost criterion which penalizes deviations between the position of the effector and the target throughout the trial, forcing arrival on target before the final time. To investigate which model gives the best fit to the data and to see whether that model is generic, we tested both models in two different tasks where subjects used a joystick to steer a ball on a screen to hit a target (first task or one of two targets (second task before a final time. Noise of different amplitudes was superimposed on the ball position to investigate the ability of the models to predict motor behavior for different levels of uncertainty. The results show that a cost function representing only a trade-off between effort and accuracy at the end time is insufficient to describe the observed behavior. The new model correctly predicts that subjects steer the ball to the target position well before the final time is reached, which is in agreement with the observed behavior. This result is consistent for all noise amplitudes and for both tasks.

  3. POSITION ERROR IN STATION-KEEPING SATELLITE

    Science.gov (United States)

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

  4. Pendulum Shifts, Context, Error, and Personal Accountability

    Energy Technology Data Exchange (ETDEWEB)

    Harold Blackman; Oren Hester

    2011-09-01

    This paper describes a series of tools that were developed to achieve a balance in under-standing LOWs and the human component of events (including accountability) as the INL continues its shift to a learning culture where people report, are accountable and interested in making a positive difference - and want to report because information is handled correctly and the result benefits both the reporting individual and the organization. We present our model for understanding these interrelationships; the initiatives that were undertaken to improve overall performance.

  5. Beam positioning error budget in ICF driver

    CERN Document Server

    Shi Zhi Quan; Su Jing Qin

    2002-01-01

    The author presents the method of linear weight sum to beam positioning budget on the basis of ICF request on targeting, the approach of equal or unequal probability to allocate errors to each optical element. Based on the relationship between the motion of the optical components and beam position on target, the position error of the optical components was evaluated, which was referred to as the maximum range. Lots of ray trace were performed, the position error budget were modified by law of the normal distribution. An overview of position error budget of the components is provided

  6. Sources of Error in Satellite Navigation Positioning

    Directory of Open Access Journals (Sweden)

    Jacek Januszewski

    2017-09-01

    Full Text Available An uninterrupted information about the user’s position can be obtained generally from satellite navigation system (SNS. At the time of this writing (January 2017 currently two global SNSs, GPS and GLONASS, are fully operational, two next, also global, Galileo and BeiDou are under construction. In each SNS the accuracy of the user’s position is affected by the three main factors: accuracy of each satellite position, accuracy of pseudorange measurement and satellite geometry. The user’s position error is a function of both the pseudorange error called UERE (User Equivalent Range Error and user/satellite geometry expressed by right Dilution Of Precision (DOP coefficient. This error is decomposed into two types of errors: the signal in space ranging error called URE (User Range Error and the user equipment error UEE. The detailed analyses of URE, UEE, UERE and DOP coefficients, and the changes of DOP coefficients in different days are presented in this paper.

  7. Quantum Error Correction Beyond Completely Positive Maps

    OpenAIRE

    Shabani, A.; Lidar, D. A.

    2006-01-01

    By introducing an operator sum representation for arbitrary linear maps, we develop a generalized theory of quantum error correction (QEC) that applies to any linear map, in particular maps that are not completely positive (CP). This theory of "linear quantum error correction" is applicable in cases where the standard and restrictive assumption of a factorized initial system-bath state does not apply.

  8. ERROR COMPENSATOR FOR A POSITION TRANSDUCER

    Science.gov (United States)

    Fowler, A.H.

    1962-06-12

    A device is designed for eliminating the effect of leadscrew errors in positioning machines in which linear motion of a slide is effected from rotary motion of a leadscrew. This is accomplished by providing a corrector cam mounted on the slide, a cam follower, and a transducer housing rotatable by the follower to compensate for all the reproducible errors in the transducer signal which can be related to the slide position. The transducer has an inner part which is movable with respect to the transducer housing. The transducer inner part is coupled to the means for rotating the leadscrew such that relative movement between this part and its housing will provide an output signal proportional to the position of the slide. The corrector cam and its follower perform the compensation by changing the angular position of the transducer housing by an amount that is a function of the slide position and the error at that position. (AEC)

  9. Detecting Positioning Errors and Estimating Correct Positions by Moving Window.

    Science.gov (United States)

    Song, Ha Yoon; Lee, Jun Seok

    2015-01-01

    In recent times, improvements in smart mobile devices have led to new functionalities related to their embedded positioning abilities. Many related applications that use positioning data have been introduced and are widely being used. However, the positioning data acquired by such devices are prone to erroneous values caused by environmental factors. In this research, a detection algorithm is implemented to detect erroneous data over a continuous positioning data set with several options. Our algorithm is based on a moving window for speed values derived by consecutive positioning data. Both the moving average of the speed and standard deviation in a moving window compose a moving significant interval at a given time, which is utilized to detect erroneous positioning data along with other parameters by checking the newly obtained speed value. In order to fulfill the designated operation, we need to examine the physical parameters and also determine the parameters for the moving windows. Along with the detection of erroneous speed data, estimations of correct positioning are presented. The proposed algorithm first estimates the speed, and then the correct positions. In addition, it removes the effect of errors on the moving window statistics in order to maintain accuracy. Experimental verifications based on our algorithm are presented in various ways. We hope that our approach can help other researchers with regard to positioning applications and human mobility research.

  10. Error compensation algorithm for patient positioning robotics system

    Science.gov (United States)

    Murty, Pilaka V.; Talpasanu, Ilie; Roz, Mugur A.

    2009-03-01

    Surgeons in various medical areas (orthopedic surgery, neurosurgery, dentistry etc.) are using motor-driven drilling tools to make perforations in hard tissues (bone, enamel, dentine, cementum etc.) When the penetration requires very precise angles and accurate alignment with respect to different targets, precision cannot be obtained by using visual estimation and hand-held tools. Robots have been designed to allow for very accurate relative positioning of the patient and the surgical tools, and in certain classes of applications the location of bone target and inclination of the surgical tool can be accurately specified with respect to an inertial frame of reference. However, patient positioning errors as well as position changes during surgery can jeopardize the precision of the operation, and drilling parameters have to be dynamically adjusted. In this paper the authors present a quantitative method to evaluate the corrected position and inclination of the drilling tool, to account for translational and rotational errors in displaced target position. The compensation algorithm applies principles of inverse kinematics wherein a faulty axis in space caused by the translational and rotational errors of the target position is identified with an imaginary true axis in space by enforcing identity through a modified trajectory. In the absence of any specific application, this algorithm is verified on Solid Works, a commercial CAD tool and found to be correct. An example problem given at the end vindicates this statement.

  11. Accounting for observation errors in image data assimilation

    Directory of Open Access Journals (Sweden)

    Vincent Chabot

    2015-02-01

    Full Text Available This paper deals with the assimilation of image-type data. Such kinds of data, such as satellite images, have good properties (dense coverage in space and time, but also one crucial problem for data assimilation: they are affected by spatially correlated errors. Classical approaches in data assimilation assume uncorrelated noise, because the proper description and numerical manipulation of non-diagonal error covariance matrices is complex. This paper proposes a simple way to provide observation error covariance matrices adapted to spatially correlated errors. This is done using various image transformations: multiscale (Wavelets, Fourier, Curvelets, gradients, and gradient orientations. These transformations are described and compared to classical approaches, such as pixel-to-pixel comparison and observation thinning. We provide simple yet effective covariance matrices for each of these transformations, which take into account the observation error correlations and improve the results. The effectiveness of the proposed approach is demonstrated on twin experiments performed on a 2-D shallow-water model.

  12. Planet position errors in planetary transmission: Effect on load sharing and transmission error

    Science.gov (United States)

    Iglesias, Miguel; Fernández, Alfonso; De-Juan, Ana; Sancibrián, Ramón; García, Pablo

    2013-03-01

    In this paper an advanced model of spur gear transmissions developed by the authors is used to study the influence of carrier planet pin hole position errors on the behaviour of the transmission. The model, initially conceived for external gear modeling, has been extended with internal meshing features, and thus increasing its capabilities to include planetary transmission modeling. The new features are presented, along with the summary of the model general approach. The parameters and characteristics of the planetary transmission used in the paper are introduced. The influence of carrier planet pin hole position errors on the planet load sharing is studied, and several static cases are given as examples in order to show the ability of the model. Tangential and radial planet pin hole position errors are considered independently, and the effect of the load level is also taken into account. It is also given attention to the effect on the transmission error of the transmission. Two different configurations for the planetary transmission are used, attending to the fixed or floating condition of the sun, and the differences in terms of load sharing ratio are shown.

  13. Effect of Altitude Error on Position Precision of Double-Star Position System

    Institute of Scientific and Technical Information of China (English)

    LIN Xueyuan; LI Tingjun; QIU Libo; LIN Yu

    2006-01-01

    The effects of two kinds of methods for obtaining altitudes on the position precision are analyzed, and the error expressions are deduced. Many simulation results show that in the two cases, the effects of the same altitude errors on the positioning precision are identical, and the rules that the two altitude errors affect positioning precision can be expressed as that altitude error has little effect on the east-west position error, but has large effect on the south-north position error.

  14. Robust topology optimization accounting for spatially varying manufacturing errors

    DEFF Research Database (Denmark)

    Schevenels, M.; Lazarov, Boyan Stefanov; Sigmund, Ole

    2011-01-01

    This paper presents a robust approach for the design of macro-, micro-, or nano-structures by means of topology optimization, accounting for spatially varying manufacturing errors. The focus is on structures produced by milling or etching; in this case over- or under-etching may cause parts...... optimization problem is formulated in a probabilistic way: the objective function is defined as a weighted sum of the mean value and the standard deviation of the structural performance. The optimization problem is solved by means of a Monte Carlo method: in each iteration of the optimization scheme, a Monte...

  15. Erasing errors due to alignment ambiguity when estimating positive selection.

    Science.gov (United States)

    Redelings, Benjamin

    2014-08-01

    Current estimates of diversifying positive selection rely on first having an accurate multiple sequence alignment. Simulation studies have shown that under biologically plausible conditions, relying on a single estimate of the alignment from commonly used alignment software can lead to unacceptably high false-positive rates in detecting diversifying positive selection. We present a novel statistical method that eliminates excess false positives resulting from alignment error by jointly estimating the degree of positive selection and the alignment under an evolutionary model. Our model treats both substitutions and insertions/deletions as sequence changes on a tree and allows site heterogeneity in the substitution process. We conduct inference starting from unaligned sequence data by integrating over all alignments. This approach naturally accounts for ambiguous alignments without requiring ambiguously aligned sites to be identified and removed prior to analysis. We take a Bayesian approach and conduct inference using Markov chain Monte Carlo to integrate over all alignments on a fixed evolutionary tree topology. We introduce a Bayesian version of the branch-site test and assess the evidence for positive selection using Bayes factors. We compare two models of differing dimensionality using a simple alternative to reversible-jump methods. We also describe a more accurate method of estimating the Bayes factor using Rao-Blackwellization. We then show using simulated data that jointly estimating the alignment and the presence of positive selection solves the problem with excessive false positives from erroneous alignments and has nearly the same power to detect positive selection as when the true alignment is known. We also show that samples taken from the posterior alignment distribution using the software BAli-Phy have substantially lower alignment error compared with MUSCLE, MAFFT, PRANK, and FSA alignments.

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

    Science.gov (United States)

    Lihua, Ma; Wang, Meng

    2013-09-01

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

  17. Positioning errors and quality assessment in panoramic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Dhillon, Manu; Lakhanpal, Manisha; Krishnamoorthy, Bhuvana [Dept. of Oral Medicine and Radiology, ITS Centre for Dental Studies and Research, Ghaziabad (India); Raju, Srinivasa M [Dept. of Oral Medicine and Radiology, Teerthanker Mahavir Dental College, Moradabad (India); Verma, Sankalp; Mohan, Raviprakash S [Dept. of Oral Medicine and Radiology, Kothiwal Dental College and Research Centre, Moradabad (India); Tomar, Divya [Dept. of Pedodontics and Preventive Dentistry, IDST Dental College and Research Centre, Modinagar (India)

    2012-09-15

    This study was performed to determine the relative frequency of positioning errors, to identify those errors directly responsible for diagnostically inadequate images, and to assess the quality of panoramic radiographs in a sample of records collected from a dental college. This study consisted of 1,782 panoramic radiographs obtained from the Department of Oral and Maxillofacial Radiology. The positioning errors of the radiographs were assessed and categorized into nine groups: the chin tipped high, chin tipped low, a slumped position, the patient positioned forward, the patient positioned backward, failure to position the tongue against the palate, patient movement during exposure, the head tilted, and the head turned to one side. The quality of the radiographs was further judged as being 'excellent', 'diagnostically acceptable', or 'unacceptable'. Out of 1,782 radiographs, 196 (11%) were error free and 1,586 (89%) were present with positioning errors. The most common error observed was the failure to position the tongue against the palate (55.7%) and the least commonly experienced error was patient movement during exposure (1.6%). Only 11% of the radiographs were excellent, 64.1% were diagnostically acceptable, and 24.9% were unacceptable. The positioning errors found on panoramic radiographs were relatively common in our study. The quality of panoramic radiographs could be improved by careful attention to patient positioning.

  18. Homography-Based Correction of Positional Errors in MRT Survey

    CERN Document Server

    Nayak, Arvind; Shankar, N Udaya

    2009-01-01

    The Mauritius Radio Telescope (MRT) images show systematics in the positional errors of sources when compared to source positions in the Molonglo Reference Catalogue (MRC). We have applied two-dimensional homography to correct positional errors in the image domain and avoid re-processing the visibility data. Positions of bright (above 15-$\\sigma$) sources, common to MRT and MRC catalogues, are used to set up an over-determined system to solve for the 2-D homography matrix. After correction, the errors are found to be within 10% of the beamwidth for these bright sources and the systematics are eliminated from the images.

  19. Approaches to relativistic positioning around Earth and error estimations

    CERN Document Server

    Puchades, Neus

    2016-01-01

    In the context of relativistic positioning, the coordinates of a given user may be calculated by using suitable information broadcast by a 4-tuple of satellites. Our 4-tuples belong to the Galileo constellation. Recently, we estimated the positioning errors due to uncertainties in the satellite world lines (U-errors). A distribution of U-errors was obtained, at various times, in a set of points covering a large region surrounding Earth. Here, the positioning errors associated to the simplifying assumption that photons move in Minkowski space-time (S-errors) are estimated and compared with the U-errors. Both errors have been calculated for the same points and times to make comparisons possible. For a certain realistic modeling of the world line uncertainties, the estimated S-errors have proved to be smaller than the U-errors, which shows that the approach based on the assumption that the Earth's gravitational field produces negligible effects on photons may be used in a large region surrounding Earth. The appl...

  20. Positional Velar Fronting: An Updated Articulatory Account

    Science.gov (United States)

    Byun, Tara McAllister

    2012-01-01

    This study develops the hypothesis that the child-specific phenomenon of positional velar fronting can be modeled as the product of phonologically encoded articulatory limitations unique to immature speakers. Children have difficulty executing discrete tongue movements, preferring to move the tongue and jaw as a single unit. This predisposes the…

  1. Performance of muon reconstruction including Alignment Position Errors for 2016 Collision Data

    CERN Document Server

    CMS Collaboration

    2016-01-01

    From 2016 Run muon reconstruction is using non-zero Alignment Position Errors to account for the residual uncertainties of muon chambers' positions. Significant improvements are obtained in particular for the startup phase after opening/closing the muon detector. Performance results are presented for real data and MC simulations, related to both the offline reconstruction and the High-Level Trigger.

  2. Model of Head-Positioning Error Due to Rotational Vibration of Hard Disk Drives

    Science.gov (United States)

    Matsuda, Yasuhiro; Yamaguchi, Takashi; Saegusa, Shozo; Shimizu, Toshihiko; Hamaguchi, Tetsuya

    An analytical model of head-positioning error due to rotational vibration of a hard disk drive is proposed. The model takes into account the rotational vibration of the base plate caused by the reaction force of the head-positioning actuator, the relationship between the rotational vibration and head-track offset, and the sensitivity function of track-following feedback control. Error calculated by the model agrees well with measured error. It is thus concluded that this model can predict the data transfer performance of a disk drive in read mode.

  3. Research on Positioning Error Compensation for Micro Milling Machine Tool

    Institute of Scientific and Technical Information of China (English)

    Ming-Jun Chen; Wen-Lan Tian; Yong Xiao; Yan Jiang

    2014-01-01

    Micro milling has many advantages in fabricating three⁃dimensional ( 3D) structure in micrometer scale. The micro milling machine tool with high positioning accuracy is of great importance for getting micro structure with high profile precision and good surface quality. Meanwhile, the method of position error compensation is a good way to improve the accuracy of the micro milling machine tools. In this paper, a software method is adopted to compensate the positioning error and improve the positioning accuracy. According to error cancellation theory, the compensation values are generated and compensation tables are built to adjust the positioning error in the NC system based on Industrial Motion and Automation Control ( IMAC) . The positioning accuracy of linear motor is ±0�3μm without backlash after compensation. In order to verify the effectiveness of compensation on the machining performance, concave spherical surfaces are processed on the micro milling machine tool. The experimental results show that the profile radius error of the spherical surface machined with compensation decreases more than 60%.

  4. Experimental investigation of false positive errors in auditory species occurrence surveys

    Science.gov (United States)

    Miller, David A.W.; Weir, Linda A.; McClintock, Brett T.; Grant, Evan H. Campbell; Bailey, Larissa L.; Simons, Theodore R.

    2012-01-01

    methods. Instructing observers to only report detections they are completely certain are correct is not sufficient to eliminate errors. As a result, analytical methods that account for false positive errors will be needed, and independent testing of observer ability is a useful predictor for among-observer variation in observation error rates.

  5. Positional error in automated geocoding of residential addresses

    Directory of Open Access Journals (Sweden)

    Talbot Thomas O

    2003-12-01

    Full Text Available Abstract Background Public health applications using geographic information system (GIS technology are steadily increasing. Many of these rely on the ability to locate where people live with respect to areas of exposure from environmental contaminants. Automated geocoding is a method used to assign geographic coordinates to an individual based on their street address. This method often relies on street centerline files as a geographic reference. Such a process introduces positional error in the geocoded point. Our study evaluated the positional error caused during automated geocoding of residential addresses and how this error varies between population densities. We also evaluated an alternative method of geocoding using residential property parcel data. Results Positional error was determined for 3,000 residential addresses using the distance between each geocoded point and its true location as determined with aerial imagery. Error was found to increase as population density decreased. In rural areas of an upstate New York study area, 95 percent of the addresses geocoded to within 2,872 m of their true location. Suburban areas revealed less error where 95 percent of the addresses geocoded to within 421 m. Urban areas demonstrated the least error where 95 percent of the addresses geocoded to within 152 m of their true location. As an alternative to using street centerline files for geocoding, we used residential property parcel points to locate the addresses. In the rural areas, 95 percent of the parcel points were within 195 m of the true location. In suburban areas, this distance was 39 m while in urban areas 95 percent of the parcel points were within 21 m of the true location. Conclusion Researchers need to determine if the level of error caused by a chosen method of geocoding may affect the results of their project. As an alternative method, property data can be used for geocoding addresses if the error caused by traditional methods is

  6. Perceptual learning eases crowding by reducing recognition errors but not position errors.

    Science.gov (United States)

    Xiong, Ying-Zi; Yu, Cong; Zhang, Jun-Yun

    2015-08-01

    When an observer reports a letter flanked by additional letters in the visual periphery, the response errors (the crowding effect) may result from failure to recognize the target letter (recognition errors), from mislocating a correctly recognized target letter at a flanker location (target misplacement errors), or from reporting a flanker as the target letter (flanker substitution errors). Crowding can be reduced through perceptual learning. However, it is not known how perceptual learning operates to reduce crowding. In this study we trained observers with a partial-report task (Experiment 1), in which they reported the central target letter of a three-letter string presented in the visual periphery, or a whole-report task (Experiment 2), in which they reported all three letters in order. We then assessed the impact of training on recognition of both unflanked and flanked targets, with particular attention to how perceptual learning affected the types of errors. Our results show that training improved target recognition but not single-letter recognition, indicating that training indeed affected crowding. However, training did not reduce target misplacement errors or flanker substitution errors. This dissociation between target recognition and flanker substitution errors supports the view that flanker substitution may be more likely a by-product (due to response bias), rather than a cause, of crowding. Moreover, the dissociation is not consistent with hypothesized mechanisms of crowding that would predict reduced positional errors.

  7. Data-processing induced GPS-positioning error

    Directory of Open Access Journals (Sweden)

    Tian Yunfeng

    2012-08-01

    Full Text Available Global Positioning System data processing is affected by many non-tectonic factors, including the common-mode errors (CME in station-position time series. The characteristics and origins of CME are still not clear, due to uneven distribution of global CPS networks and the lack of reliable data of the position time series. In this work, data from 241 continuous CPS stations were reprocessed in a consistent way and the results were compared with those generated at Jet Propulsion Laboratory (JPL. Improvements of residual positions were obtained for many low-quality stations, especially those located in Asia and Australia. Key words: GPS; position time series; reprocessing; non-tectonic; common-mode error

  8. Positioning errors in digital panoramic radiographs: A study

    Directory of Open Access Journals (Sweden)

    A Cicilia Subbulakshmi

    2016-01-01

    Full Text Available Panoramic radiography is a unique and a very useful extraoral film technique that allows the dentist to view the entire dentition and related structures, from condyle to condyle, on one film. Capturing a wide range of structures on a single film grounds the odds of errors in the digital panoramic radiographs. Improper positioning of the patient complicates it more, reducing the diagnostic usefulness of these radiographs. Wide knowledge about the common positioning errors and the ways to rectify it benefits the dentists in interpretation and diagnosis. Aim: This study is aimed at analyzing the 10 common positional errors (anteriorly positioned, posteriorly positioned, head tilted upwards, head tilted downwards, head twisted to one side, head tipped, overlapping of spine in lower anterior region, tongue not placed close to palate, patient movement, and ghost images in 200 digital panoramic radiographs selected randomly. Materials and Methods: Two hundred digital panoramic radiographic images of the patients above 6 years of age were selected randomly from the stored data in the system, projected on the white screen, and studied. The radiographs were analyzed by two oral medicine and radiology specialists, by recording separately, and then the results were analyzed. Results: The most common error was failure to place the tongue close to the palate, which leads to the presence of radiolucent airspace obscuring the roots of the maxillary teeth.

  9. Optimal control design that accounts for model mismatch errors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T.J. [Sandia National Labs., Albuquerque, NM (United States); Hull, D.G. [Texas Univ., Austin, TX (United States). Dept. of Aerospace Engineering and Engineering Mechanics

    1995-02-01

    A new technique is presented in this paper that reduces the complexity of state differential equations while accounting for modeling assumptions. The mismatch controls are defined as the differences between the model equations and the true state equations. The performance index of the optimal control problem is formulated with a set of tuning parameters that are user-selected to tune the control solution in order to achieve the best results. Computer simulations demonstrate that the tuned control law outperforms the untuned controller and produces results that are comparable to a numerically-determined, piecewise-linear optimal controller.

  10. Position determination and measurement error analysis for the spherical proof mass with optical shadow sensing

    Science.gov (United States)

    Hou, Zhendong; Wang, Zhaokui; Zhang, Yulin

    2016-09-01

    To meet the very demanding requirements for space gravity detection, the gravitational reference sensor (GRS) as the key payload needs to offer the relative position of the proof mass with extraordinarily high precision and low disturbance. The position determination and error analysis for the GRS with a spherical proof mass is addressed. Firstly the concept of measuring the freely falling proof mass with optical shadow sensors is presented. Then, based on the optical signal model, the general formula for position determination is derived. Two types of measurement system are proposed, for which the analytical solution to the three-dimensional position can be attained. Thirdly, with the assumption of Gaussian beams, the error propagation models for the variation of spot size and optical power, the effect of beam divergence, the chattering of beam center, and the deviation of beam direction are given respectively. Finally, the numerical simulations taken into account of the model uncertainty of beam divergence, spherical edge and beam diffraction are carried out to validate the performance of the error propagation models. The results show that these models can be used to estimate the effect of error source with an acceptable accuracy which is better than 20%. Moreover, the simulation for the three-dimensional position determination with one of the proposed measurement system shows that the position error is just comparable to the error of the output of each sensor.

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

    Science.gov (United States)

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

    2012-01-01

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

  12. Accounting for L2 learners’ errors in word stress placement

    Directory of Open Access Journals (Sweden)

    Clara Herlina Karjo

    2016-01-01

    Full Text Available Stress placement in English words is governed by highly complicated rules. Thus, assigning stress correctly in English words has been a challenging task for L2 learners, especially Indonesian learners since their L1 does not recognize such stress system. This study explores the production of English word stress by 30 university students. The method used for this study is immediate repetition task. Participants are instructed to identify the stress placement of 80 English words which are auditorily presented as stimuli and immediately repeat the words with correct stress placement. The objectives of this study are to find out whether English word stress placement is problematic for L2 learners and to investigate the phonological factors which account for these problems. Research reveals that L2 learners have different ability in producing the stress, but three-syllable words are more problematic than two-syllable words. Moreover, misplacement of stress is caused by, among others, the influence of vowel lenght and vowel height.

  13. Historical shoreline mapping (I): improving techniques and reducing positioning errors

    Science.gov (United States)

    Thieler, E. Robert; Danforth, William W.

    1994-01-01

    A critical need exists among coastal researchers and policy-makers for a precise method to obtain shoreline positions from historical maps and aerial photographs. A number of methods that vary widely in approach and accuracy have been developed to meet this need. None of the existing methods, however, address the entire range of cartographic and photogrammetric techniques required for accurate coastal mapping. Thus, their application to many typical shoreline mapping problems is limited. In addition, no shoreline mapping technique provides an adequate basis for quantifying the many errors inherent in shoreline mapping using maps and air photos. As a result, current assessments of errors in air photo mapping techniques generally (and falsely) assume that errors in shoreline positions are represented by the sum of a series of worst-case assumptions about digitizer operator resolution and ground control accuracy. These assessments also ignore altogether other errors that commonly approach ground distances of 10 m. This paper provides a conceptual and analytical framework for improved methods of extracting geographic data from maps and aerial photographs. We also present a new approach to shoreline mapping using air photos that revises and extends a number of photogrammetric techniques. These techniques include (1) developing spatially and temporally overlapping control networks for large groups of photos; (2) digitizing air photos for use in shoreline mapping; (3) preprocessing digitized photos to remove lens distortion and film deformation effects; (4) simultaneous aerotriangulation of large groups of spatially and temporally overlapping photos; and (5) using a single-ray intersection technique to determine geographic shoreline coordinates and express the horizontal and vertical error associated with a given digitized shoreline. As long as historical maps and air photos are used in studies of shoreline change, there will be a considerable amount of error (on the

  14. Accounting for model error due to unresolved scales within ensemble Kalman filtering

    CERN Document Server

    Mitchell, Lewis

    2014-01-01

    We propose a method to account for model error due to unresolved scales in the context of the ensemble transform Kalman filter (ETKF). The approach extends to this class of algorithms the deterministic model error formulation recently explored for variational schemes and extended Kalman filter. The model error statistic required in the analysis update is estimated using historical reanalysis increments and a suitable model error evolution law. Two different versions of the method are described; a time-constant model error treatment where the same model error statistical description is time-invariant, and a time-varying treatment where the assumed model error statistics is randomly sampled at each analysis step. We compare both methods with the standard method of dealing with model error through inflation and localization, and illustrate our results with numerical simulations on a low order nonlinear system exhibiting chaotic dynamics. The results show that the filter skill is significantly improved through th...

  15. CORRECTING ACCOUNTING ERRORS AND ACKNOWLEDGING THEM IN THE EARNINGS TO THE PERIOD

    Directory of Open Access Journals (Sweden)

    BUSUIOCEANU STELIANA

    2013-08-01

    Full Text Available The accounting information is reliable when it does not contain significant errors, is not biasedand accurately represents the transactions and events. In the light of the regulations complying with Europeandirectives, the information is significant if its omission or wrong presentation may influence the decisions users makebased on annual financial statements. Given that the professional practice sees errors in registering or interpretinginformation, as well as omissions and wrong calculations, the Romanian accounting regulations stipulate treatmentsfor correcting errors in compliance with international references. Thus, the correction of the errors corresponding tothe current period is accomplished based on the retained earnings in the case of significant errors or on the currentearnings when the errors are insignificant. The different situations in the professional practice triggered by errorsrequire both knowledge of regulations and professional rationale to be addressed.

  16. Development of an RTK-GPS Positioning Application with an Improved Position Error Model for Smartphones

    Directory of Open Access Journals (Sweden)

    Dongha Lee

    2012-09-01

    Full Text Available This study developed a smartphone application that provides wireless communication, NRTIP client, and RTK processing features, and which can simplify the Network RTK-GPS system while reducing the required cost. A determination method for an error model in Network RTK measurements was proposed, considering both random and autocorrelation errors, to accurately calculate the coordinates measured by the application using state estimation filters. The performance evaluation of the developed application showed that it could perform high-precision real-time positioning, within several centimeters of error range at a frequency of 20 Hz. A Kalman Filter was applied to the coordinates measured from the application, to evaluate the appropriateness of the determination method for an error model, as proposed in this study. The results were more accurate, compared with those of the existing error model, which only considered the random error.

  17. Development of an RTK-GPS positioning application with an improved position error model for smartphones.

    Science.gov (United States)

    Hwang, Jinsang; Yun, Hongsik; Suh, Yongcheol; Cho, Jeongho; Lee, Dongha

    2012-09-25

    This study developed a smartphone application that provides wireless communication, NRTIP client, and RTK processing features, and which can simplify the Network RTK-GPS system while reducing the required cost. A determination method for an error model in Network RTK measurements was proposed, considering both random and autocorrelation errors, to accurately calculate the coordinates measured by the application using state estimation filters. The performance evaluation of the developed application showed that it could perform high-precision real-time positioning, within several centimeters of error range at a frequency of 20 Hz. A Kalman Filter was applied to the coordinates measured from the application, to evaluate the appropriateness of the determination method for an error model, as proposed in this study. The results were more accurate, compared with those of the existing error model, which only considered the random error.

  18. Accounting for covariate measurement error in a Cox model analysis of recurrence of depression.

    Science.gov (United States)

    Liu, K; Mazumdar, S; Stone, R A; Dew, M A; Houck, P R; Reynolds, C F

    2001-01-01

    When a covariate measured with error is used as a predictor in a survival analysis using the Cox model, the parameter estimate is usually biased. In clinical research, covariates measured without error such as treatment procedure or sex are often used in conjunction with a covariate measured with error. In a randomized clinical trial of two types of treatments, we account for the measurement error in the covariate, log-transformed total rapid eye movement (REM) activity counts, in a Cox model analysis of the time to recurrence of major depression in an elderly population. Regression calibration and two variants of a likelihood-based approach are used to account for measurement error. The likelihood-based approach is extended to account for the correlation between replicate measures of the covariate. Using the replicate data decreases the standard error of the parameter estimate for log(total REM) counts while maintaining the bias reduction of the estimate. We conclude that covariate measurement error and the correlation between replicates can affect results in a Cox model analysis and should be accounted for. In the depression data, these methods render comparable results that have less bias than the results when measurement error is ignored.

  19. Common positioning errors in panoramic radiography: A review

    Energy Technology Data Exchange (ETDEWEB)

    Randon, Rafael Henrique Nunes [Stomathology and Oral Diagnostic Program, School of Dentistry of Sao Paulo, University of Sao Paulo, Sao Paulo (Brazil); Pereira, Yamba Carla Lara [Biology Dental Buco Graduate Program, School of Dentistry of Piracicaba, University of Campinas, Piracicaba (Brazil); Nascimento, Glauce Crivelaro do [Psychobiology Graduate Program, School of Philosophy, Science and Literature of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto (Brazil)

    2014-03-15

    Professionals performing radiographic examinations are responsible for maintaining optimal image quality for accurate diagnoses. These professionals must competently execute techniques such as film manipulation and processing to minimize patient exposure to radiation. Improper performance by the professional and/or patient may result in a radiographic image of unsatisfactory quality that can also lead to a misdiagnosis and the development of an inadequate treatment plan. Currently, the most commonly performed extraoral examination is panoramic radiography. The invention of panoramic radiography has resulted in improvements in image quality with decreased exposure to radiation and at a low cost. However, this technique requires careful, accurate positioning of the patient's teeth and surrounding maxillofacial bone structure within the focal trough. Therefore, we reviewed the literature for the most common types of positioning errors in panoramic radiography to suggest the correct techniques. We would also discuss how to determine if the most common positioning errors occurred in panoramic radiography, such as in the positioning of the patient's head, tongue, chin, or body.

  20. Sensorless SPMSM Position Estimation Using Position Estimation Error Suppression Control and EKF in Wide Speed Range

    OpenAIRE

    Zhanshan Wang; Longhu Quan; Xiuchong Liu

    2014-01-01

    The control of a high performance alternative current (AC) motor drive under sensorless operation needs the accurate estimation of rotor position. In this paper, one method of accurately estimating rotor position by using both motor complex number model based position estimation and position estimation error suppression proportion integral (PI) controller is proposed for the sensorless control of the surface permanent magnet synchronous motor (SPMSM). In order to guarantee the accuracy of rot...

  1. Coordinated joint motion control system with position error correction

    Energy Technology Data Exchange (ETDEWEB)

    Danko, George (Reno, NV)

    2011-11-22

    Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two-joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

  2. Coordinated joint motion control system with position error correction

    Energy Technology Data Exchange (ETDEWEB)

    Danko, George L.

    2016-04-05

    Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

  3. Visual End-Effector Position Error Compensation for Planetary Robotics

    Science.gov (United States)

    Bajracharya, Max; DiCicco, Matthew; Backes, Paul; Nickels, Kevin

    2007-01-01

    This paper describes a vision-guided manipulation algorithm that improves arm end-effector positioning to subpixel accuracy and meets the highly restrictive imaging and computational constraints of a planetary robotic flight system. Analytical, simulation-based, and experimental analyses of the algorithm's effectiveness and sensitivity to camera and arm model error is presented along with results on several prototype research systems and 'ground-in-the-loop' technology experiments on the Mars Exploration Rover (MER) vehicles. A computationally efficient and robust subpixel end-effector fiducial detector that is instrumental to the algorithm's ability to achieve high accuracy is also described along with its validation results on MER data.

  4. Visual End-Effector Position Error Compensation for Planetary Robotics

    Science.gov (United States)

    Bajracharya, Max; DiCicco, Matthew; Backes, Paul; Nickels, Kevin

    2007-01-01

    This paper describes a vision-guided manipulation algorithm that improves arm end-effector positioning to subpixel accuracy and meets the highly restrictive imaging and computational constraints of a planetary robotic flight system. Analytical, simulation-based, and experimental analyses of the algorithm's effectiveness and sensitivity to camera and arm model error is presented along with results on several prototype research systems and 'ground-in-the-loop' technology experiments on the Mars Exploration Rover (MER) vehicles. A computationally efficient and robust subpixel end-effector fiducial detector that is instrumental to the algorithm's ability to achieve high accuracy is also described along with its validation results on MER data.

  5. Correcting a fundamental error in greenhouse gas accounting related to bioenergy

    DEFF Research Database (Denmark)

    Haberl, Helmut; Sprinz, Detlef; Bonazountas, Marc

    2012-01-01

    and soils, or reduces carbon sequestration. Neglecting this fact results in an accounting error that could be corrected by considering that only the use of ‘additional biomass’ – biomass from additional plant growth or biomass that would decompose rapidly if not used for bioenergy – can reduce carbon...... emissions. Failure to correct this accounting flaw will likely have substantial adverse consequences. The article presents recommendations for correcting greenhouse gas accounts related to bioenergy....

  6. Estimating the acute health effects of coarse particulate matter accounting for exposure measurement error.

    Science.gov (United States)

    Chang, Howard H; Peng, Roger D; Dominici, Francesca

    2011-10-01

    In air pollution epidemiology, there is a growing interest in estimating the health effects of coarse particulate matter (PM) with aerodynamic diameter between 2.5 and 10 μm. Coarse PM concentrations can exhibit considerable spatial heterogeneity because the particles travel shorter distances and do not remain suspended in the atmosphere for an extended period of time. In this paper, we develop a modeling approach for estimating the short-term effects of air pollution in time series analysis when the ambient concentrations vary spatially within the study region. Specifically, our approach quantifies the error in the exposure variable by characterizing, on any given day, the disagreement in ambient concentrations measured across monitoring stations. This is accomplished by viewing monitor-level measurements as error-prone repeated measurements of the unobserved population average exposure. Inference is carried out in a Bayesian framework to fully account for uncertainty in the estimation of model parameters. Finally, by using different exposure indicators, we investigate the sensitivity of the association between coarse PM and daily hospital admissions based on a recent national multisite time series analysis. Among Medicare enrollees from 59 US counties between the period 1999 and 2005, we find a consistent positive association between coarse PM and same-day admission for cardiovascular diseases.

  7. Nonlinear control of ships minimizing the position tracking errors

    Directory of Open Access Journals (Sweden)

    Svein P. Berge

    1999-07-01

    Full Text Available In this paper, a nonlinear tracking controller with integral action for ships is presented. The controller is based on state feedback linearization. Exponential convergence of the vessel-fixed position and velocity errors are proven by using Lyapunov stability theory. Since we only have two control devices, a rudder and a propeller, we choose to control the longship and the sideship position errors to zero while the heading is stabilized indirectly. A Virtual Reference Point (VRP is defined at the bow or ahead of the ship. The VRP is used for tracking control. It is shown that the distance from the center of rotation to the VRP will influence on the stability of the zero dynamics. By selecting the VRP at the bow or even ahead of the bow, the damping in yaw can be increased and the zero dynamics is stabilized. Hence, the heading angle will be less sensitive to wind, currents and waves. The control law is simulated by using a nonlinear model of the Japanese training ship Shiojimaru with excellent results. Wind forces are added to demonstrate the robustness and performance of the integral controller.

  8. Chasing probabilities - Signaling negative and positive prediction errors across domains.

    Science.gov (United States)

    Meder, David; Madsen, Kristoffer H; Hulme, Oliver; Siebner, Hartwig R

    2016-07-01

    Adaptive actions build on internal probabilistic models of possible outcomes that are tuned according to the errors of their predictions when experiencing an actual outcome. Prediction errors (PEs) inform choice behavior across a diversity of outcome domains and dimensions, yet neuroimaging studies have so far only investigated such signals in singular experimental contexts. It is thus unclear whether the neuroanatomical distribution of PE encoding reported previously pertains to computational features that are invariant with respect to outcome valence, sensory domain, or some combination of the two. We acquired functional MRI data while volunteers performed four probabilistic reversal learning tasks which differed in terms of outcome valence (reward-seeking versus punishment-avoidance) and domain (abstract symbols versus facial expressions) of outcomes. We found that ventral striatum and frontopolar cortex coded increasingly positive PEs, whereas dorsal anterior cingulate cortex (dACC) traced increasingly negative PEs, irrespectively of the outcome dimension. Individual reversal behavior was unaffected by context manipulations and was predicted by activity in dACC and right inferior frontal gyrus (IFG). The stronger the response to negative PEs in these areas, the lower was the tendency to reverse choice behavior in response to negative events, suggesting that these regions enforce a rule-based strategy across outcome dimensions. Outcome valence influenced PE-related activity in left amygdala, IFG, and dorsomedial prefrontal cortex, where activity selectively scaled with increasingly positive PEs in the reward-seeking but not punishment-avoidance context, irrespective of sensory domain. Left amygdala displayed an additional influence of sensory domain. In the context of avoiding punishment, amygdala activity increased with increasingly negative PEs, but only for facial stimuli, indicating an integration of outcome valence and sensory domain during probabilistic

  9. A log-likelihood-gain intensity target for crystallographic phasing that accounts for experimental error.

    Science.gov (United States)

    Read, Randy J; McCoy, Airlie J

    2016-03-01

    The crystallographic diffraction experiment measures Bragg intensities; crystallographic electron-density maps and other crystallographic calculations in phasing require structure-factor amplitudes. If data were measured with no errors, the structure-factor amplitudes would be trivially proportional to the square roots of the intensities. When the experimental errors are large, and especially when random errors yield negative net intensities, the conversion of intensities and their error estimates into amplitudes and associated error estimates becomes nontrivial. Although this problem has been addressed intermittently in the history of crystallographic phasing, current approaches to accounting for experimental errors in macromolecular crystallography have numerous significant defects. These have been addressed with the formulation of LLGI, a log-likelihood-gain function in terms of the Bragg intensities and their associated experimental error estimates. LLGI has the correct asymptotic behaviour for data with large experimental error, appropriately downweighting these reflections without introducing bias. LLGI abrogates the need for the conversion of intensity data to amplitudes, which is usually performed with the French and Wilson method [French & Wilson (1978), Acta Cryst. A35, 517-525], wherever likelihood target functions are required. It has general applicability for a wide variety of algorithms in macromolecular crystallography, including scaling, characterizing anisotropy and translational noncrystallographic symmetry, detecting outliers, experimental phasing, molecular replacement and refinement. Because it is impossible to reliably recover the original intensity data from amplitudes, it is suggested that crystallographers should always deposit the intensity data in the Protein Data Bank.

  10. 38 CFR 2.7 - Delegation of authority to provide relief on account of administrative error.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Delegation of authority to provide relief on account of administrative error. 2.7 Section 2.7 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS DELEGATIONS OF AUTHORITY § 2.7 Delegation of authority to...

  11. On a Test of Hypothesis to Verify the Operating Risk Due to Accountancy Errors

    Directory of Open Access Journals (Sweden)

    Paola Maddalena Chiodini

    2014-12-01

    Full Text Available According to the Statement on Auditing Standards (SAS No. 39 (AU 350.01, audit sampling is defined as “the application of an audit procedure to less than 100 % of the items within an account balance or class of transactions for the purpose of evaluating some characteristic of the balance or class”. The audit system develops in different steps: some are not susceptible to sampling procedures, while others may be held using sampling techniques. The auditor may also be interested in two types of accounting error: the number of incorrect records in the sample that overcome a given threshold (natural error rate, which may be indicative of possible fraud, and the mean amount of monetary errors found in incorrect records. The aim of this study is to monitor jointly both types of errors through an appropriate system of hypotheses, with particular attention to the second type error that indicates the risk of non-reporting errors overcoming the upper precision limits.

  12. Sensorless SPMSM Position Estimation Using Position Estimation Error Suppression Control and EKF in Wide Speed Range

    Directory of Open Access Journals (Sweden)

    Zhanshan Wang

    2014-01-01

    Full Text Available The control of a high performance alternative current (AC motor drive under sensorless operation needs the accurate estimation of rotor position. In this paper, one method of accurately estimating rotor position by using both motor complex number model based position estimation and position estimation error suppression proportion integral (PI controller is proposed for the sensorless control of the surface permanent magnet synchronous motor (SPMSM. In order to guarantee the accuracy of rotor position estimation in the flux-weakening region, one scheme of identifying the permanent magnet flux of SPMSM by extended Kalman filter (EKF is also proposed, which formed the effective combination method to realize the sensorless control of SPMSM with high accuracy. The simulation results demonstrated the validity and feasibility of the proposed position/speed estimation system.

  13. POSITIONAL ERROR CURVES BAND OF A PLANAR LINE SEGMENT WITHIN GISs

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, the positional error curve of point features was extended to an error curves band of line segment features. Firstly, the constitution and shape of the error curves band were analyzed. On this basis, the general boundary curve formula of that band was derived. Secondly, the visualizing error curves bands were realized through three exam ples. Finally, area index has been examined by comparing numerical results from error curves band and error ellipes band.

  14. Propagation of positional error in 3D GIS

    NARCIS (Netherlands)

    Biljecki, Filip; Heuvelink, Gerard B.M.; Ledoux, Hugo; Stoter, Jantien

    2015-01-01

    While error propagation in GIS is a topic that has received a lot of attention, it has not been researched with 3D GIS data. We extend error propagation to 3D city models using a Monte Carlo simulation on a use case of annual solar irradiation estimation of building rooftops for assessing the eff

  15. A computational account of altered error processing in older age: Dopamine and the error-related negativity

    NARCIS (Netherlands)

    Nieuwenhuis, Sander; Ridderinkhof, K. Richard; Talsma, Durk; Coles, Michael G.H.; Holroyd, Clay B.; Kok, Albert; Molen, van der Maurits W.

    2002-01-01

    When participants commit errors or receive feedback signaling that they have made an error, a negative brain potential is elicited. According to Holroyd and Coles’s (in press) neurocomputational model of error processing, this error-related negativity (ERN) is elicited when the brain first detects t

  16. A computational account of altered error processing in older age: Dopamine and the error-related negativity

    NARCIS (Netherlands)

    Nieuwenhuis, S.; Ridderinkhof, K.R.; Talsma, D.; Coles, M.G.; Holroyd, C.B.; Kok, A.

    2002-01-01

    When participants commit errors or receive feedback signaling that they have made an error, a negative brain potential is elicited. According to Holroyd and Coles's (in press) neurocomputational model of error processing, this error-related negativity (ERN) is elicited when the brain first detects t

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

    Science.gov (United States)

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

    2017-10-01

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

  18. Evaluating the Effect of Global Positioning System (GPS) Satellite Clock Error via GPS Simulation

    Science.gov (United States)

    Sathyamoorthy, Dinesh; Shafii, Shalini; Amin, Zainal Fitry M.; Jusoh, Asmariah; Zainun Ali, Siti

    2016-06-01

    This study is aimed at evaluating the effect of Global Positioning System (GPS) satellite clock error using GPS simulation. Two conditions of tests are used; Case 1: All the GPS satellites have clock errors within the normal range of 0 to 7 ns, corresponding to pseudorange error range of 0 to 2.1 m; Case 2: One GPS satellite suffers from critical failure, resulting in clock error in the pseudorange of up to 1 km. It is found that increase of GPS satellite clock error causes increase of average positional error due to increase of pseudorange error in the GPS satellite signals, which results in increasing error in the coordinates computed by the GPS receiver. Varying average positional error patterns are observed for the each of the readings. This is due to the GPS satellite constellation being dynamic, causing varying GPS satellite geometry over location and time, resulting in GPS accuracy being location / time dependent. For Case 1, in general, the highest average positional error values are observed for readings with the highest PDOP values, while the lowest average positional error values are observed for readings with the lowest PDOP values. For Case 2, no correlation is observed between the average positional error values and PDOP, indicating that the error generated is random.

  19. Accounting for sampling variability, injury under-reporting, and sensor error in concussion injury risk curves.

    Science.gov (United States)

    Elliott, Michael R; Margulies, Susan S; Maltese, Matthew R; Arbogast, Kristy B

    2015-09-18

    There has been recent dramatic increase in the use of sensors affixed to the heads or helmets of athletes to measure the biomechanics of head impacts that lead to concussion. The relationship between injury and linear or rotational head acceleration measured by such sensors can be quantified with an injury risk curve. The utility of the injury risk curve relies on the accuracy of both the clinical diagnosis and the biomechanical measure. The focus of our analysis was to demonstrate the influence of three sources of error on the shape and interpretation of concussion injury risk curves: sampling variability associated with a rare event, concussion under-reporting, and sensor measurement error. We utilized Bayesian statistical methods to generate synthetic data from previously published concussion injury risk curves developed using data from helmet-based sensors on collegiate football players and assessed the effect of the three sources of error on the risk relationship. Accounting for sampling variability adds uncertainty or width to the injury risk curve. Assuming a variety of rates of unreported concussions in the non-concussed group, we found that accounting for under-reporting lowers the rotational acceleration required for a given concussion risk. Lastly, after accounting for sensor error, we find strengthened relationships between rotational acceleration and injury risk, further lowering the magnitude of rotational acceleration needed for a given risk of concussion. As more accurate sensors are designed and more sensitive and specific clinical diagnostic tools are introduced, our analysis provides guidance for the future development of comprehensive concussion risk curves.

  20. Verification of the Mechanism of the Head-Positioning Error Caused by Disk Flutter and Slider Supporting Structure for Reducing Head-Positioning Error

    Science.gov (United States)

    Imai, Satomitsu

    In magnetic disk drives, the disk flutter due to high-rotational speed causes the increase of the head-positioning error. It is important to clear the mechanism of the head-positioning error caused by the disk flutter. This paper conducts the experiments to verify the mechanism proposed in the former report. The experiment was conducted by comparing the head-positioning error predicted by the proposed mechanism with the measured head-positioning error signal. It is confirmed that the proposed mechanism can predict the head-positioning error within the 10% error. The former reports also said that the flutter transfer ratio defined in the report could decrease the head-positioning error without reducing the amplitude of the disk flutter. This paper also verifies it experimentally. In the experiment, the thickness of the slider was changed to make the flutter transfer ratio small. This paper also proposes the method of making the beam angle of the gimbal slant to make the flutter transfer ratio small. The effectiveness was confirmed by the simulation.

  1. Contributions to Positioning Accounting in Relation to Scientific Research

    OpenAIRE

    Vasile Patrut

    2009-01-01

    The paper approaches some epistemological and methodological aspects of scientific research in accounting, such as: the distinction between accounting research and scientific research in accounting; the products, dynamics and mechanism of scientific creation; scientific research as a fundamental premise of scientific creation; the challenges and conditions of scientific creation; the double standing of accounting, as object and result of the research, in relation to scientific research.

  2. Gateways to Positioning Information and Communication Technology in Accounting Education

    Science.gov (United States)

    Rhodes, N.

    2012-01-01

    In terms of technology, accounting education has not evolved to the extent required by industry and has created a gap in the knowledge and skills of accounting graduates. This article reports on how an educational research tool assisted in finding a place for information and communication technology in accounting education. This article also…

  3. Gateways to Positioning Information and Communication Technology in Accounting Education

    Science.gov (United States)

    Rhodes, N.

    2012-01-01

    In terms of technology, accounting education has not evolved to the extent required by industry and has created a gap in the knowledge and skills of accounting graduates. This article reports on how an educational research tool assisted in finding a place for information and communication technology in accounting education. This article also…

  4. Target registration and target positioning errors in computer-assisted neurosurgery: proposal for a standardized reporting of error assessment.

    Science.gov (United States)

    Widmann, Gerlig; Stoffner, Rudolf; Sieb, Michael; Bale, Reto

    2009-12-01

    Assessment of errors is essential in development, testing and clinical application of computer-assisted neurosurgery. Our aim was to provide a comprehensive overview of the different methods to assess target registration error (TRE) and target positioning error (TPE) and to develop a proposal for a standardized reporting of error assessment. A PubMed research on phantom, cadaver or clinical studies on TRE and TPE has been performed. Reporting standards have been defined according to (a) study design and evaluation methods and (b) specifications of the navigation technology. The proposed standardized reporting includes (a) study design (controlled, non-controlled), study type (non-anthropomorphic phantom, anthropomorphic phantom, cadaver, patient), target design, error type and subtypes, space of TPE measurement, statistics, and (b) image modality, scan parameters, tracking technology, registration procedure and targeting technique. Adoption of the proposed standardized reporting may help in the understanding and comparability of different accuracy reports. Copyright (c) 2009 John Wiley & Sons, Ltd.

  5. Error Analysis System for Spacecraft Navigation Using the Global Positioning System (GPS)

    Science.gov (United States)

    Truong, S. H.; Hart, R. C.; Hartman, K. R.; Tomcsik, T. L.; Searl, J. E.; Bernstein, A.

    1997-01-01

    The Flight Dynamics Division (FDD) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) is currently developing improved space-navigation filtering algorithms to use the Global Positioning System (GPS) for autonomous real-time onboard orbit determination. In connection with a GPS technology demonstration on the Small Satellite Technology Initiative (SSTI)/Lewis spacecraft, FDD analysts and programmers have teamed with the GSFC Guidance, Navigation, and Control Branch to develop the GPS Enhanced Orbit Determination Experiment (GEODE) system. The GEODE system consists of a Kalman filter operating as a navigation tool for estimating the position, velocity, and additional states required to accurately navigate the orbiting Lewis spacecraft by using astrodynamic modeling and GPS measurements from the receiver. A parallel effort at the FDD is the development of a GPS Error Analysis System (GEAS) that will be used to analyze and improve navigation filtering algorithms during development phases and during in-flight calibration. For GEAS, the Kalman filter theory is extended to estimate the errors in position, velocity, and other error states of interest. The estimation of errors in physical variables at regular intervals will allow the time, cause, and effect of navigation system weaknesses to be identified. In addition, by modeling a sufficient set of navigation system errors, a system failure that causes an observed error anomaly can be traced and accounted for. The GEAS software is formulated using Object Oriented Design (OOD) techniques implemented in the C++ programming language on a Sun SPARC workstation. The Phase 1 of this effort is the development of a basic system to be used to evaluate navigation algorithms implemented in the GEODE system. This paper presents the GEAS mathematical methodology, systems and operations concepts, and software design and implementation. Results from the use of the basic system to evaluate

  6. Cognitive control of conscious error awareness: error awareness and error positivity (Pe) amplitude in moderate-to-severe traumatic brain injury (TBI).

    Science.gov (United States)

    Logan, Dustin M; Hill, Kyle R; Larson, Michael J

    2015-01-01

    Poor awareness has been linked to worse recovery and rehabilitation outcomes following moderate-to-severe traumatic brain injury (M/S TBI). The error positivity (Pe) component of the event-related potential (ERP) is linked to error awareness and cognitive control. Participants included 37 neurologically healthy controls and 24 individuals with M/S TBI who completed a brief neuropsychological battery and the error awareness task (EAT), a modified Stroop go/no-go task that elicits aware and unaware errors. Analyses compared between-group no-go accuracy (including accuracy between the first and second halves of the task to measure attention and fatigue), error awareness performance, and Pe amplitude by level of awareness. The M/S TBI group decreased in accuracy and maintained error awareness over time; control participants improved both accuracy and error awareness during the course of the task. Pe amplitude was larger for aware than unaware errors for both groups; however, consistent with previous research on the Pe and TBI, there were no significant between-group differences for Pe amplitudes. Findings suggest possible attention difficulties and low improvement of performance over time may influence specific aspects of error awareness in M/S TBI.

  7. Analysis of the systematic errors in the positions of BATSE catalog bursts

    CERN Document Server

    Graziani, C; Graziani, Carlo; Lamb, Don Q

    1996-01-01

    We analyze the systematic errors in the positions of bursts in the BATSE 1B, 2B and 3B catalogs, using a likelihood approach. We use the BATSE data in conjunction with 196 single IPN arcs. We assume circular Gaussian errors, and that the total error is the sum in quadrature of the systematic error \\sigma_{\\rm sys} and statistical error \\sigma_{\\rm stat}, as prescribed by the BATSE catalog. We find that the 3B burst positions are inconsistent with the value \\sigma_{\\rm sys} = 1.6^\\circ stated in the BATSE 3B catalog.

  8. Panel positioning error and support mechanism for a 30-m THz radio telescope

    Institute of Scientific and Technical Information of China (English)

    De-Hua Yang; Daniel Okoh; Guo-Hua Zhou; Ai-Hua Li; Guo-Ping Li; Jing-Quan Cheng

    2011-01-01

    A 30-m TeraHertz (THz) radio telescope is proposed to operate at 200 μm with an active primary surface. This paper presents sensitivity analysis of active surface panel positioning errors with optical performance in terms of the Strehl ratio.Based on Ruze's surface error theory and using a Monte Carlo simulation, the effects of six rigid panel positioning errors, such as piston, tip, tilt, radial, azimuthal and twist displacements, were directly derived. The optical performance of the telescope was then evaluated using the standard Strehl ratio. We graphically illustrated the various panel error effects by presenting simulations of complete ensembles of full reflector surface errors for the six different rigid panel positioning errors. Study of the panel error sensitivity analysis revealed that the piston error and tilt/tip errors are dominant while the other rigid errors are much less important. Furthermore, as indicated by the results, we conceived of an alternative Master-Slave Concept-based (MSC-based) active surface by implementating a special Series-Parallel Concept-based (SPC-based) hexapod as the active panel support mechanism. A new 30-m active reflector based on the two concepts was demonstrated to achieve correction for all the six rigid panel positioning errors in an economically feasible way.

  9. Accounting for environmental variability, modeling errors, and parameter estimation uncertainties in structural identification

    Science.gov (United States)

    Behmanesh, Iman; Moaveni, Babak

    2016-07-01

    This paper presents a Hierarchical Bayesian model updating framework to account for the effects of ambient temperature and excitation amplitude. The proposed approach is applied for model calibration, response prediction and damage identification of a footbridge under changing environmental/ambient conditions. The concrete Young's modulus of the footbridge deck is the considered updating structural parameter with its mean and variance modeled as functions of temperature and excitation amplitude. The identified modal parameters over 27 months of continuous monitoring of the footbridge are used to calibrate the updating parameters. One of the objectives of this study is to show that by increasing the levels of information in the updating process, the posterior variation of the updating structural parameter (concrete Young's modulus) is reduced. To this end, the calibration is performed at three information levels using (1) the identified modal parameters, (2) modal parameters and ambient temperatures, and (3) modal parameters, ambient temperatures, and excitation amplitudes. The calibrated model is then validated by comparing the model-predicted natural frequencies and those identified from measured data after deliberate change to the structural mass. It is shown that accounting for modeling error uncertainties is crucial for reliable response prediction, and accounting only the estimated variability of the updating structural parameter is not sufficient for accurate response predictions. Finally, the calibrated model is used for damage identification of the footbridge.

  10. Correcting a fundamental error in greenhouse gas accounting related to bioenergy

    Science.gov (United States)

    Haberl, Helmut; Sprinz, Detlef; Bonazountas, Marc; Cocco, Pierluigi; Desaubies, Yves; Henze, Mogens; Hertel, Ole; Johnson, Richard K.; Kastrup, Ulrike; Laconte, Pierre; Lange, Eckart; Novak, Peter; Paavola, Jouni; Reenberg, Anette; van den Hove, Sybille; Vermeire, Theo; Wadhams, Peter; Searchinger, Timothy

    2012-01-01

    Many international policies encourage a switch from fossil fuels to bioenergy based on the premise that its use would not result in carbon accumulation in the atmosphere. Frequently cited bioenergy goals would at least double the present global human use of plant material, the production of which already requires the dedication of roughly 75% of vegetated lands and more than 70% of water withdrawals. However, burning biomass for energy provision increases the amount of carbon in the air just like burning coal, oil or gas if harvesting the biomass decreases the amount of carbon stored in plants and soils, or reduces carbon sequestration. Neglecting this fact results in an accounting error that could be corrected by considering that only the use of ‘additional biomass’ – biomass from additional plant growth or biomass that would decompose rapidly if not used for bioenergy – can reduce carbon emissions. Failure to correct this accounting flaw will likely have substantial adverse consequences. The article presents recommendations for correcting greenhouse gas accounts related to bioenergy. PMID:23576835

  11. Correcting a fundamental error in greenhouse gas accounting related to bioenergy.

    Science.gov (United States)

    Haberl, Helmut; Sprinz, Detlef; Bonazountas, Marc; Cocco, Pierluigi; Desaubies, Yves; Henze, Mogens; Hertel, Ole; Johnson, Richard K; Kastrup, Ulrike; Laconte, Pierre; Lange, Eckart; Novak, Peter; Paavola, Jouni; Reenberg, Anette; van den Hove, Sybille; Vermeire, Theo; Wadhams, Peter; Searchinger, Timothy

    2012-06-01

    Many international policies encourage a switch from fossil fuels to bioenergy based on the premise that its use would not result in carbon accumulation in the atmosphere. Frequently cited bioenergy goals would at least double the present global human use of plant material, the production of which already requires the dedication of roughly 75% of vegetated lands and more than 70% of water withdrawals. However, burning biomass for energy provision increases the amount of carbon in the air just like burning coal, oil or gas if harvesting the biomass decreases the amount of carbon stored in plants and soils, or reduces carbon sequestration. Neglecting this fact results in an accounting error that could be corrected by considering that only the use of 'additional biomass' - biomass from additional plant growth or biomass that would decompose rapidly if not used for bioenergy - can reduce carbon emissions. Failure to correct this accounting flaw will likely have substantial adverse consequences. The article presents recommendations for correcting greenhouse gas accounts related to bioenergy.

  12. Investigating impacts of positional error on potential health care accessibility.

    Science.gov (United States)

    Bell, Scott; Wilson, Kathi; Shah, Tayyab Ikram; Gersher, Sarina; Elliott, Tina

    2012-04-01

    Accessibility to health services at the local or community level is an effective approach to measuring health care delivery in various constituencies in Canada and the United States. GIS and spatial methods play an important role in measuring potential access to health services. The Three-Step Floating Catchment Area (3SFCA) method is a GIS based procedure developed to calculate potential (spatial) accessibility as a ratio of primary health care (PHC) providers to the surrounding population in urban settings. This method uses PHC provider locations in textual/address format supplied by local, regional, or national health authorities. An automated geocoding procedure is normally used to convert such addresses to a pair of geographic coordinates. The accuracy of geocoding depends on the type of reference data and the amount of value-added effort applied. This research investigates the success and accuracy of six geocoding methods as well as how geocoding error affects the 3SFCA method. ArcGIS software is used for geocoding and spatial accessibility estimation. Results will focus on two implications of geocoding: (1) the success and accuracy of different automated and value-added geocoding; and (2) the implications of these geocoding methods for GIS-based methods that generalise results based on location data.

  13. Accounting for nonsampling error in estimates of HIV epidemic trends from antenatal clinic sentinel surveillance.

    Science.gov (United States)

    Eaton, Jeffrey W; Bao, Le

    2017-04-01

    The aim of the study was to propose and demonstrate an approach to allow additional nonsampling uncertainty about HIV prevalence measured at antenatal clinic sentinel surveillance (ANC-SS) in model-based inferences about trends in HIV incidence and prevalence. Mathematical model fitted to surveillance data with Bayesian inference. We introduce a variance inflation parameter (Equation is included in full-text article.)that accounts for the uncertainty of nonsampling errors in ANC-SS prevalence. It is additive to the sampling error variance. Three approaches are tested for estimating (Equation is included in full-text article.)using ANC-SS and household survey data from 40 subnational regions in nine countries in sub-Saharan, as defined in UNAIDS 2016 estimates. Methods were compared using in-sample fit and out-of-sample prediction of ANC-SS data, fit to household survey prevalence data, and the computational implications. Introducing the additional variance parameter (Equation is included in full-text article.)increased the error variance around ANC-SS prevalence observations by a median of 2.7 times (interquartile range 1.9-3.8). Using only sampling error in ANC-SS prevalence (Equation is included in full-text article.), coverage of 95% prediction intervals was 69% in out-of-sample prediction tests. This increased to 90% after introducing the additional variance parameter (Equation is included in full-text article.). The revised probabilistic model improved model fit to household survey prevalence and increased epidemic uncertainty intervals most during the early epidemic period before 2005. Estimating (Equation is included in full-text article.)did not increase the computational cost of model fitting. We recommend estimating nonsampling error in ANC-SS as an additional parameter in Bayesian inference using the Estimation and Projection Package model. This approach may prove useful for incorporating other data sources such as routine prevalence from Prevention of

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

    Science.gov (United States)

    Jacquez, Geoffrey M

    2012-04-01

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

  15. Modeling the probability distribution of positional errors incurred by residential address geocoding

    Directory of Open Access Journals (Sweden)

    Mazumdar Soumya

    2007-01-01

    Full Text Available Abstract Background The assignment of a point-level geocode to subjects' residences is an important data assimilation component of many geographic public health studies. Often, these assignments are made by a method known as automated geocoding, which attempts to match each subject's address to an address-ranged street segment georeferenced within a streetline database and then interpolate the position of the address along that segment. Unfortunately, this process results in positional errors. Our study sought to model the probability distribution of positional errors associated with automated geocoding and E911 geocoding. Results Positional errors were determined for 1423 rural addresses in Carroll County, Iowa as the vector difference between each 100%-matched automated geocode and its true location as determined by orthophoto and parcel information. Errors were also determined for 1449 60%-matched geocodes and 2354 E911 geocodes. Huge (> 15 km outliers occurred among the 60%-matched geocoding errors; outliers occurred for the other two types of geocoding errors also but were much smaller. E911 geocoding was more accurate (median error length = 44 m than 100%-matched automated geocoding (median error length = 168 m. The empirical distributions of positional errors associated with 100%-matched automated geocoding and E911 geocoding exhibited a distinctive Greek-cross shape and had many other interesting features that were not capable of being fitted adequately by a single bivariate normal or t distribution. However, mixtures of t distributions with two or three components fit the errors very well. Conclusion Mixtures of bivariate t distributions with few components appear to be flexible enough to fit many positional error datasets associated with geocoding, yet parsimonious enough to be feasible for nascent applications of measurement-error methodology to spatial epidemiology.

  16. Accounting for baseline differences and measurement error in the analysis of change over time.

    Science.gov (United States)

    Braun, Julia; Held, Leonhard; Ledergerber, Bruno

    2014-01-15

    If change over time is compared in several groups, it is important to take into account baseline values so that the comparison is carried out under the same preconditions. As the observed baseline measurements are distorted by measurement error, it may not be sufficient to include them as covariate. By fitting a longitudinal mixed-effects model to all data including the baseline observations and subsequently calculating the expected change conditional on the underlying baseline value, a solution to this problem has been provided recently so that groups with the same baseline characteristics can be compared. In this article, we present an extended approach where a broader set of models can be used. Specifically, it is possible to include any desired set of interactions between the time variable and the other covariates, and also, time-dependent covariates can be included. Additionally, we extend the method to adjust for baseline measurement error of other time-varying covariates. We apply the methodology to data from the Swiss HIV Cohort Study to address the question if a joint infection with HIV-1 and hepatitis C virus leads to a slower increase of CD4 lymphocyte counts over time after the start of antiretroviral therapy.

  17. Positioning Error Analysis of Ranging-Mode Using AIS Signals in China

    Directory of Open Access Journals (Sweden)

    Kai Zheng

    2016-01-01

    Full Text Available In order to provide resilient position, navigation, and time (PNT information for E-Navigation, the ranging-mode (R-Mode positioning using automatic identification system (AIS signals is encouraged. As the accuracy is the key for the positioning system, this paper investigates the position error of the R-Mode positioning based on AIS shore-based station in China. The measurement errors of Gaussian filtered minimum shift keying (GMSK demodulation based on carrier phase locking loop are investigated in theory. The dilution of precision (DOP for time of arrival (TOA and time difference of arrival (TDOA used in R-Mode positioning of AIS is discussed in two measurement mechanisms. The positioning error distributions in the North, East, and South Sea regions of China based on the existing AIS shore-based stations are evaluated. The positioning accuracy is at the meter level in the most traffic dense areas to meet the requirements for vessel navigation.

  18. CALIBRATION ERRORS IN THE CAVITY BEAM POSITION MONITOR SYSTEM AT THE ATF2

    CERN Document Server

    Cullinan, F; Joshi, N; Lyapin, A

    2011-01-01

    It has been shown at the Accelerator Test Facility at KEK, that it is possible to run a system of 37 cavity beam position monitors (BPMs) and achieve high working resolution. However, stability of the calibration constants (position scale and radio frequency (RF) phase) over a three/four week running period is yet to be demonstrated. During the calibration procedure, random beam jitter gives rise to a statistical error in the position scale and slow orbit drift in position and tilt causes systematic errors in both the position scale and RF phase. These errors are dominant and have been evaluated for each BPM. The results are compared with the errors expected after a tested method of beam jitter subtraction has been applied.

  19. Development of a simple test device for spindle error measurement using a position sensitive detector

    Science.gov (United States)

    Liu, Chien-Hung; Jywe, Wen-Yuh; Lee, Hau-Wei

    2004-09-01

    A new spindle error measurement system has been developed in this paper. It employs a design development rotational fixture with a built-in laser diode and four batteries to replace a precision reference master ball or cylinder used in the traditional method. Two measuring devices with two position sensitive detectors (one is designed for the measurement of the compound X-axis and Y-axis errors and the other is designed with a lens for the measurement of the tilt angular errors) are fixed on the machine table to detect the laser point position from the laser diode in the rotational fixture. When the spindle rotates, the spindle error changes the direction of the laser beam. The laser beam is then divided into two separated beams by a beam splitter. The two separated beams are projected onto the two measuring devices and are detected by two position sensitive detectors, respectively. Thus, the compound motion errors and the tilt angular errors of the spindle can be obtained. Theoretical analysis and experimental tests are presented in this paper to separate the compound errors into two radial errors and tilt angular errors. This system is proposed as a new instrument and method for spindle metrology.

  20. Positioning Errors Predicting Method of Strapdown Inertial Navigation Systems Based on PSO-SVM

    Directory of Open Access Journals (Sweden)

    Xunyuan Yin

    2013-01-01

    Full Text Available The strapdown inertial navigation systems (SINS have been widely used for many vehicles, such as commercial airplanes, Unmanned Aerial Vehicles (UAVs, and other types of aircrafts. In order to evaluate the navigation errors precisely and efficiently, a prediction method based on support vector machine (SVM is proposed for positioning error assessment. Firstly, SINS error models that are used for error calculation are established considering several error resources with respect to inertial units. Secondly, flight paths for simulation are designed. Thirdly, the -SVR based prediction method is proposed to predict the positioning errors of navigation systems, and particle swarm optimization (PSO is used for the SVM parameters optimization. Finally, 600 sets of error parameters of SINS are utilized to train the SVM model, which is used for the performance prediction of new navigation systems. By comparing the predicting results with the real errors, the latitudinal predicting accuracy is 92.73%, while the longitudinal predicting accuracy is 91.64%, and PSO is effective to increase the prediction accuracy compared with traditional SVM with fixed parameters. This method is also demonstrated to be effective for error prediction for an entire flight process. Moreover, the prediction method can save 75% of calculation time compared with analyses based on error models.

  1. The Pe of Perfectionism Concern Over Mistakes Predicts the Amplitude of a Late Frontal Error Positivity

    NARCIS (Netherlands)

    Tops, Mattie; Koole, Sander L.; Wijers, Albertus A.

    2013-01-01

    The present research investigates the association between concern over mistakes (CoM), a facet of the personality style of perfectionism, and the error positivity (Pe), a response-locked event-related brain potential that relates to error-awareness. Sixteen healthy right-handed female participants p

  2. Putting Reward in Art: A Tentative Prediction Error Account of Visual Art

    Directory of Open Access Journals (Sweden)

    Sander Van de Cruys

    2011-12-01

    Full Text Available The predictive coding model is increasingly and fruitfully used to explain a wide range of findings in perception. Here we discuss the potential of this model in explaining the mechanisms underlying aesthetic experiences. Traditionally art appreciation has been associated with concepts such as harmony, perceptual fluency, and the so-called good Gestalt. We observe that more often than not great artworks blatantly violate these characteristics. Using the concept of prediction error from the predictive coding approach, we attempt to resolve this contradiction. We argue that artists often destroy predictions that they have first carefully built up in their viewers, and thus highlight the importance of negative affect in aesthetic experience. However, the viewer often succeeds in recovering the predictable pattern, sometimes on a different level. The ensuing rewarding effect is derived from this transition from a state of uncertainty to a state of increased predictability. We illustrate our account with several example paintings and with a discussion of art movements and individual differences in preference. On a more fundamental level, our theorizing leads us to consider the affective implications of prediction confirmation and violation. We compare our proposal to other influential theories on aesthetics and explore its advantages and limitations.

  3. Position error correction in absolute surface measurement based on a multi-angle averaging method

    Science.gov (United States)

    Wang, Weibo; Wu, Biwei; Liu, Pengfei; Liu, Jian; Tan, Jiubin

    2017-04-01

    We present a method for position error correction in absolute surface measurement based on a multi-angle averaging method. Differences in shear rotation measurements at overlapping areas can be used to estimate the unknown relative position errors of the measurements. The model and the solving of the estimation algorithm have been discussed in detail. The estimation algorithm adopts a least-squares technique to eliminate azimuthal errors caused by rotation inaccuracy. The cost functions can be minimized to determine the true values of the unknowns of Zernike polynomial coefficients and rotation angle. Experimental results show the validity of the method proposed.

  4. Accounting for systematic errors in bioluminescence imaging to improve quantitative accuracy

    Science.gov (United States)

    Taylor, Shelley L.; Perry, Tracey A.; Styles, Iain B.; Cobbold, Mark; Dehghani, Hamid

    2015-07-01

    Bioluminescence imaging (BLI) is a widely used pre-clinical imaging technique, but there are a number of limitations to its quantitative accuracy. This work uses an animal model to demonstrate some significant limitations of BLI and presents processing methods and algorithms which overcome these limitations, increasing the quantitative accuracy of the technique. The position of the imaging subject and source depth are both shown to affect the measured luminescence intensity. Free Space Modelling is used to eliminate the systematic error due to the camera/subject geometry, removing the dependence of luminescence intensity on animal position. Bioluminescence tomography (BLT) is then used to provide additional information about the depth and intensity of the source. A substantial limitation in the number of sources identified using BLI is also presented. It is shown that when a given source is at a significant depth, it can appear as multiple sources when imaged using BLI, while the use of BLT recovers the true number of sources present.

  5. Coherent detection of position errors in inter-satellite laser communications

    Science.gov (United States)

    Xu, Nan; Liu, Liren; Liu, De'an; Sun, Jianfeng; Luan, Zhu

    2007-09-01

    Due to the improved receiver sensitivity and wavelength selectivity, coherent detection became an attractive alternative to direct detection in inter-satellite laser communications. A novel method to coherent detection of position errors information is proposed. Coherent communication system generally consists of receive telescope, local oscillator, optical hybrid, photoelectric detector and optical phase lock loop (OPLL). Based on the system composing, this method adds CCD and computer as position error detector. CCD captures interference pattern while detection of transmission data from the transmitter laser. After processed and analyzed by computer, target position information is obtained from characteristic parameter of the interference pattern. The position errors as the control signal of PAT subsystem drive the receiver telescope to keep tracking to the target. Theoretical deviation and analysis is presented. The application extends to coherent laser rang finder, in which object distance and position information can be obtained simultaneously.

  6. A dynamic compensation strategy to correct patient-positioning errors in conformal prostate radiotherapy.

    Science.gov (United States)

    Lauve, A D; Siebers, J V; Crimaldi, A J; Hagan, M P; Kealla, P J

    2006-06-01

    Traditionally, pretreatment detected patient-positioning errors have been corrected by repositioning the couch to align the patient to the treatment beam. We investigated an alternative strategy: aligning the beam to the patient by repositioning the dynamic multileaf collimator and adjusting the beam weights, termed dynamic compensation. The purpose of this study was to determine the geometric range of positioning errors for which the dynamic compensation method is valid in prostate cancer patients treated with three-dimensional conformal radiotherapy. Twenty-five previously treated prostate cancer patients were replanned using a four-field technique to deliver 72 Gy to 95% of the planning target volume (PTV). Patient-positioning errors were introduced by shifting the patient reference frame with respect to the treatment isocenter. Thirty-six randomly selected isotropic displacements with magnitudes of 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 cm were sampled for each patient, for a total of 5400 errors. Dynamic compensation was used to correct each of these errors by conforming the beam apertures to the new target position and adjusting the monitor units using inverse-square and off-axis factor corrections. The dynamic compensation plans were then compared with the original treatment plans via dose-volume histogram (DVH) analysis. Changes of more than 5% of the prescription dose, 3.6 Gy, were deemed significant. Compared with the original treatment plans, dynamic compensation produced small discrepancies in isodose distributions and DVH analyses. These differences increased with the magnitudes of the initial patient-positioning errors. Coverage of the PTV was excellent: D95 and Dmean were not increased or decreased by more than 5% of the prescription dose, and D5 was not decreased by more than 5% of the prescription dose for any of the 5400 simulated positioning errors. D5 was increased by more than 5% of the prescription dose in only three of the 5400 positioning errors

  7. The effects of alignment error and alignment filtering on the sitewise detection of positive selection.

    Science.gov (United States)

    Jordan, Gregory; Goldman, Nick

    2012-04-01

    When detecting positive selection in proteins, the prevalence of errors resulting from misalignment and the ability of alignment filters to mitigate such errors are not well understood, but filters are commonly applied to try to avoid false positive results. Focusing on the sitewise detection of positive selection across a wide range of divergence levels and indel rates, we performed simulation experiments to quantify the false positives and false negatives introduced by alignment error and the ability of alignment filters to improve performance. We found that some aligners led to many false positives, whereas others resulted in very few. False negatives were a problem for all aligners, increasing with sequence divergence. Of the aligners tested, PRANK's codon-based alignments consistently performed the best and ClustalW performed the worst. Of the filters tested, GUIDANCE performed the best and Gblocks performed the worst. Although some filters showed good ability to reduce the error rates from ClustalW and MAFFT alignments, none were found to substantially improve the performance of PRANK alignments under most conditions. Our results revealed distinct trends in error rates and power levels for aligners and filters within a biologically plausible parameter space. With the best aligner, a low false positive rate was maintained even with extremely divergent indel-prone sequences. Controls using the true alignment and an optimal filtering method suggested that performance improvements could be gained by improving aligners or filters to reduce the prevalence of false negatives, especially at higher divergence levels and indel rates.

  8. Simultaneous estimation of QTL effects and positions when using genotype data with errors

    Indian Academy of Sciences (India)

    Liang Tong; Weijun Ma; Haidong Liu; Chaofeng Yuan; Ying Zhou

    2015-03-01

    Accurate genetic data are important prerequisite of performing genetic linkage test or association test. Currently, most analytical methods assume that the observed genotypes are correct. However, due to the constraint at the technical level, most of the genetic data that people used so far contain errors. In this paper, we considered the problem of QTL mapping based on biological data with genotyping errors. By analysing all possible genotypes of each individual in framework of multiple-interval mapping, we proposed an algorithm of inferring all model parameters through the expectation-maximization (EM) algorithm and discussed the hypothesis testing of the existence of QTL. We carried out extensive simulation studies to assess the proposed method. Simulation results showed that the new method outperforms the method that does not take the genotyping errors into account, and therefore it can decrease the impact of genotyping errors on QTL mapping. The proposed method was also applied to analyse a real barley dataset.

  9. Using self-location to calibrate the errors of observer positions for source localization

    Institute of Scientific and Technical Information of China (English)

    Wanchun Li; Wanyi Zhang; Liping Li

    2014-01-01

    The uncertainty of observers’ positions can lead to significantly degrading in source localization accuracy. This pa-per proposes a method of using self-location for calibrating the positions of observer stations in source localization to reduce the errors of the observer positions and improve the accuracy of the source localization. The relative distance measurements of the two coordinative observers are used for the linear minimum mean square error (LMMSE) estimator. The results of computer si-mulations prove the feasibility and effectiveness of the proposed method. With the general estimation errors of observers’ positions, the MSE of the source localization with self-location calibration, which is significantly lower than that without self-location calibra-tion, is approximating to the Cramer-Rao lower bound (CRLB).

  10. Consonant acquisition: a first approach to the distribution of errors in four positions in the word

    Directory of Open Access Journals (Sweden)

    Silvia Llach

    2012-12-01

    Full Text Available The goal of this study is to describe the behavior of errors in two types of onsets (initial and intervocalic and two types of codas (in the middle and end of the word in order to determine if any of these positions are more prone to specific types of errors than the others.We have looked into the errors that are frequently produced in these four contexts during the acquisition of consonant sounds in the Catalan language. The data were taken from a study on the acquisition of consonants in Catalan, carried out on 90 children between the ages of 3 and 5 years from several kindergarten schools. The results do show that there are characteristic errors depending on the position within the word.

  11. Position error in profiles retrieved from MIPAS observations with a 1-D algorithm

    Directory of Open Access Journals (Sweden)

    M. Carlotti

    2012-09-01

    Full Text Available The information load (IL analysis, first introduced for the two-dimensional approach (Carlotti and Magnani, 2009, is applied to the inversion of MIPAS observations operated with a 1-dimensional (1-D retrieval algorithm. The IL distribution of MIPAS spectra is shown to be often asymmetrical with respect to the tangent points of the observations and permits to identify the preferential latitude where the profiles retrieved with a 1-D algorithm should be geo-located. Therefore a position error is made when the tangent points of the observations are used to assign the geo-location of the retrieved profile. We assess the amplitude of the position error for some of the MIPAS main targets and we show that the IL analysis can also be used as a tool for the selection of observations that, when analyzed, minimize the position error of the retrieved profile. When the temperature (T profiles are used for the retrieval of volume mixing ratio (VMR of atmospheric constituents, the T position error (of the order of 1.5 degrees of latitude induces a VMR error that is directly connected with the horizontal T gradients. Temperature profiles can be externally-provided or determined in a previous step of the retrieval process. In the first case, the IL analysis shows that a meaningful fraction (often exceeding 50% of the VMR error deriving from the 1-D approximation is to be attributed to the mismatch between the position assigned to the external T profile and the positions where T is required by the analyzed observations. In the second case the retrieved T values suffer by an error of 1.5–2 K due to neglecting the horizontal variability of T; however the error induced on VMRs is of minor entity because of the generally small mismatch between the IL distribution of the observations analyzed to retrieve T and those analyzed to retrieve the VMR target. An estimate of the contribution of the T-position

  12. Taking the Error Term of the Factor Model into Account: The Factor Score Predictor Interval

    Science.gov (United States)

    Beauducel, Andre

    2013-01-01

    The problem of factor score indeterminacy implies that the factor and the error scores cannot be completely disentangled in the factor model. It is therefore proposed to compute Harman's factor score predictor that contains an additive combination of factor and error variance. This additive combination is discussed in the framework of classical…

  13. Finite Time Control Design for Bilateral Teleoperation System With Position Synchronization Error Constrained.

    Science.gov (United States)

    Yang, Yana; Hua, Changchun; Guan, Xinping

    2016-03-01

    Due to the cognitive limitations of the human operator and lack of complete information about the remote environment, the work performance of such teleoperation systems cannot be guaranteed in most cases. However, some practical tasks conducted by the teleoperation system require high performances, such as tele-surgery needs satisfactory high speed and more precision control results to guarantee patient' health status. To obtain some satisfactory performances, the error constrained control is employed by applying the barrier Lyapunov function (BLF). With the constrained synchronization errors, some high performances, such as, high convergence speed, small overshoot, and an arbitrarily predefined small residual constrained synchronization error can be achieved simultaneously. Nevertheless, like many classical control schemes only the asymptotic/exponential convergence, i.e., the synchronization errors converge to zero as time goes infinity can be achieved with the error constrained control. It is clear that finite time convergence is more desirable. To obtain a finite-time synchronization performance, the terminal sliding mode (TSM)-based finite time control method is developed for teleoperation system with position error constrained in this paper. First, a new nonsingular fast terminal sliding mode (NFTSM) surface with new transformed synchronization errors is proposed. Second, adaptive neural network system is applied for dealing with the system uncertainties and the external disturbances. Third, the BLF is applied to prove the stability and the nonviolation of the synchronization errors constraints. Finally, some comparisons are conducted in simulation and experiment results are also presented to show the effectiveness of the proposed method.

  14. The method to evaluate the position error in graphic positioning technology

    Institute of Scientific and Technical Information of China (English)

    Huiqing Lu(卢慧卿); Baoguang Wang(王宝光); Lishuang Liu(刘力双); Yabiao Li(李亚标)

    2004-01-01

    In the measurement of automobile body-in-white, it has been widely studied to position the two dimensional(2D)visual sensors with high precision. In this paper a graphic positioning method is proposed,a hollow tetrahedron is used for a positioning target to replace all the edges of a standard automobile body.A 2D visual sensor can be positioned through adjusting two triangles to be superposed on a screen of the computer, so it is very important to evaluate the superposition precision of the two triangles. Several methods are discussed and the least square method is adopted at last, it makes the adjustment more easy and intuitive with high precision.

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

    Science.gov (United States)

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

    2013-04-01

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

  16. Error Analysis and Reduction for Shearer Positioning using the Strapdown Inertial Navigation System

    Directory of Open Access Journals (Sweden)

    Chengming Luo

    2012-09-01

    Full Text Available Shearer dynamic positioning is a key factor for coal mine equipment automation, and it is feasible to shearer positioning using the strapdown inertial navigation system(SINS. Yet, it is very difficult to guarantee positioning accuracy by error influence. This paper provided a method for shearer positioning error analysis. Firstly, we built the shearer state equation and put forward a method called quaternion method rule. This method can deduce misalignment angle of the shearer Inertial Navigation System. Secondly, we considered the initial alignment error of INS is the main system error, the nonlinear Extended Kalman Filter (EKF is proposed to estimate and adjust the misalignment angles, as well as the shearer velocity. Shearer dynamic positioning accuracy is guaranteed by precise and fast alignment of the INS. Based on the shearer state equation; this paper derived the observation equation. Finally, we simulated the initial alignments process which contains the observation equation and initial condition, and did experiment using ADIS16350. Results show misalignment angles model and EKF is feasible for initial alignments of INS in shearer positioning.

  17. Effect of endorectal balloon positioning errors on target deformation and dosimetric quality during prostate SBRT.

    Science.gov (United States)

    Jones, Bernard L; Gan, Gregory; Kavanagh, Brian; Miften, Moyed

    2013-11-21

    An inflatable endorectal balloon (ERB) is often used during stereotactic body radiation therapy (SBRT) for treatment of prostate cancer in order to reduce both intrafraction motion of the target and risk of rectal toxicity. However, the ERB can exert significant force on the prostate, and this work assessed the impact of ERB position errors on deformation of the prostate and treatment dose metrics. Seventy-one cone-beam computed tomography (CBCT) image datasets of nine patients with clinical stage T1cN0M0 prostate cancer were studied. An ERB (Flexi-Cuff, EZ-EM, Westbury, NY) inflated with 60 cm(3) of air was used during simulation and treatment, and daily kilovoltage (kV) CBCT imaging was performed to localize the prostate. The shape of the ERB in each CBCT was analyzed to determine errors in position, size, and shape. A deformable registration algorithm was used to track the dose received by (and deformation of) the prostate, and dosimetric values such as D95, PTV coverage, and Dice coefficient for the prostate were calculated. The average balloon position error was 0.5 cm in the inferior direction, with errors ranging from 2 cm inferiorly to 1 cm superiorly. The prostate was deformed primarily in the AP direction, and tilted primarily in the anterior-posterior/superior-inferior plane. A significant correlation was seen between errors in depth of ERB insertion (DOI) and mean voxel-wise deformation, prostate tilt, Dice coefficient, and planning-to-treatment prostate inter-surface distance (p prostate D95 and PTV coverage (p prostate that negatively affect treatment, and this additional aspect of setup error should be considered when ERBs are used for prostate SBRT. Before treatment, the ERB position should be verified, and the ERB should be adjusted if the error is observed to exceed tolerable values.

  18. Evaluation of positioning errors of the patient using cone beam CT megavoltage; Evaluacion de errores de posicionamiento del paciente mediante Cone Beam CT de megavoltaje

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Ruiz-Zorrilla, J.; Fernandez Leton, J. P.; Zucca Aparicio, D.; Perez Moreno, J. M.; Minambres Moro, A.

    2013-07-01

    Image-guided radiation therapy allows you to assess and fix the positioning of the patient in the treatment unit, thus reducing the uncertainties due to the positioning of the patient. This work assesses errors systematic and errors of randomness from the corrections made to a series of patients of different diseases through a protocol off line of cone beam CT (CBCT) megavoltage. (Author)

  19. A New Calibration Method for Microphone Array with Gain, Phase, and Position Errors

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Microphone array can be used in sound source localization and separation. But gain, phase, and position errors can seriously influence the performance of localization algorithms such as multiple signal classification (MUSIC) algorithm. In this paper, a new calibration method for microphone array with gain, phase, and position errors is proposed. Unlike traditional calibration methods for antenna array, the proposed method can be used in the broadband and near-field signal model such as microphone array with arbitrary sensor geometries in one plane. Computer simulations are presented and simulation results show the new method having good performance.

  20. Influence of both angle and position error of pentaprism on accuracy of pentaprism scanning system

    Science.gov (United States)

    Xu, Kun; Han, Sen; Zhang, Qiyuan; Wu, Quanying

    2014-11-01

    Pentaprism scanning system has been widely used in the measurement of large flat and wavefront, based on its property that the deviated beam will have no motion in the pitch direction. But the manufacturing and position errors of pentaprisms will bring error to the measurement and so a good error analysis method is indispensable. In this paper, we propose a new method of building mathematic models of pentaprism and through which the size and angle errors of a pentaprism can be put into the model as parameters. 4 size parameters are selected to determine the size and 11 angle parameters are selected to determine the angles of a pentaprism. Yaw, Roll and Pitch are used to describe the position error of a pentaprism and an autocollimator. A pentaprism scanning system of wavefront test is simulated by ray tracing using matlab. We design a method of separating the constant from the measurement results which will improve the measurement accuracy and analyze the system error by Monte Carlo method. This method is simple, rapid, accurate and convenient for computer programming.

  1. The propagation of inventory-based positional errors into statistical landslide susceptibility models

    Science.gov (United States)

    Steger, Stefan; Brenning, Alexander; Bell, Rainer; Glade, Thomas

    2016-12-01

    There is unanimous agreement that a precise spatial representation of past landslide occurrences is a prerequisite to produce high quality statistical landslide susceptibility models. Even though perfectly accurate landslide inventories rarely exist, investigations of how landslide inventory-based errors propagate into subsequent statistical landslide susceptibility models are scarce. The main objective of this research was to systematically examine whether and how inventory-based positional inaccuracies of different magnitudes influence modelled relationships, validation results, variable importance and the visual appearance of landslide susceptibility maps. The study was conducted for a landslide-prone site located in the districts of Amstetten and Waidhofen an der Ybbs, eastern Austria, where an earth-slide point inventory was available. The methodological approach comprised an artificial introduction of inventory-based positional errors into the present landslide data set and an in-depth evaluation of subsequent modelling results. Positional errors were introduced by artificially changing the original landslide position by a mean distance of 5, 10, 20, 50 and 120 m. The resulting differently precise response variables were separately used to train logistic regression models. Odds ratios of predictor variables provided insights into modelled relationships. Cross-validation and spatial cross-validation enabled an assessment of predictive performances and permutation-based variable importance. All analyses were additionally carried out with synthetically generated data sets to further verify the findings under rather controlled conditions. The results revealed that an increasing positional inventory-based error was generally related to increasing distortions of modelling and validation results. However, the findings also highlighted that interdependencies between inventory-based spatial inaccuracies and statistical landslide susceptibility models are complex. The

  2. Mitigating Errors in External Respiratory Surrogate-Based Models of Tumor Position

    Energy Technology Data Exchange (ETDEWEB)

    Malinowski, Kathleen T. [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); McAvoy, Thomas J. [Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); Department of Chemical and Biomolecular Engineering and Institute of Systems Research, University of Maryland, College Park, MD (United States); George, Rohini [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Dieterich, Sonja [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); D' Souza, Warren D., E-mail: wdsou001@umaryland.edu [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States)

    2012-04-01

    Purpose: To investigate the effect of tumor site, measurement precision, tumor-surrogate correlation, training data selection, model design, and interpatient and interfraction variations on the accuracy of external marker-based models of tumor position. Methods and Materials: Cyberknife Synchrony system log files comprising synchronously acquired positions of external markers and the tumor from 167 treatment fractions were analyzed. The accuracy of Synchrony, ordinary-least-squares regression, and partial-least-squares regression models for predicting the tumor position from the external markers was evaluated. The quantity and timing of the data used to build the predictive model were varied. The effects of tumor-surrogate correlation and the precision in both the tumor and the external surrogate position measurements were explored by adding noise to the data. Results: The tumor position prediction errors increased during the duration of a fraction. Increasing the training data quantities did not always lead to more accurate models. Adding uncorrelated noise to the external marker-based inputs degraded the tumor-surrogate correlation models by 16% for partial-least-squares and 57% for ordinary-least-squares. External marker and tumor position measurement errors led to tumor position prediction changes 0.3-3.6 times the magnitude of the measurement errors, varying widely with model algorithm. The tumor position prediction errors were significantly associated with the patient index but not with the fraction index or tumor site. Partial-least-squares was as accurate as Synchrony and more accurate than ordinary-least-squares. Conclusions: The accuracy of surrogate-based inferential models of tumor position was affected by all the investigated factors, except for the tumor site and fraction index.

  3. Mediofrontal event-related potentials in response to positive, negative and unsigned prediction errors.

    Science.gov (United States)

    Sambrook, Thomas D; Goslin, Jeremy

    2014-08-01

    Reinforcement learning models make use of reward prediction errors (RPEs), the difference between an expected and obtained reward. There is evidence that the brain computes RPEs, but an outstanding question is whether positive RPEs ("better than expected") and negative RPEs ("worse than expected") are represented in a single integrated system. An electrophysiological component, feedback related negativity, has been claimed to encode an RPE but its relative sensitivity to the utility of positive and negative RPEs remains unclear. This study explored the question by varying the utility of positive and negative RPEs in a design that controlled for other closely related properties of feedback and could distinguish utility from salience. It revealed a mediofrontal sensitivity to utility, for positive RPEs at 275-310ms and for negative RPEs at 310-390ms. These effects were preceded and succeeded by a response consistent with an unsigned prediction error, or "salience" coding.

  4. Two-dimensional homography-based correction of positional errors in widefield MRT images

    CERN Document Server

    Nayak, Arvind; Shankar, N Udaya

    2010-01-01

    A steradian of the southern sky has been imaged at 151.5 MHz using the Mauritius Radio Telescope (MRT). These images show systematics in positional errors of sources when compared to source positions in the Molonglo Reference Catalogue (MRC). We have applied two-dimensional homography to correct for systematic positional errors in the image domain and thereby avoid re-processing the visibility data. Positions of bright (above 15-{\\sigma}) point sources, common to MRT catalogue and MRC, are used to set up an over-determined system to solve for the homography matrix. After correction the errors are found to be within 10% of the beamwidth for these bright sources and the systematics are eliminated from the images. This technique will be of relevance to the new generation radio telescopes where, owing to huge data rates, only images after a certain integration would be recorded as opposed to raw visibilities. It is also interesting to note how our investigations cued to possible errors in the array geometry. The ...

  5. Compensation of position errors in passivity based teleoperation over packet switched communication networks

    NARCIS (Netherlands)

    Secchi, C; Stramigioli, Stefano; Fantuzzi, C.

    Because of the use of scattering based communication channels, passivity based telemanipulation systems can be subject to a steady state position error between master and slave robots. In this paper, we consider the case in which the passive master and slave sides communicate through a packet

  6. Rail-guided robotic end-effector position error due to rail compliance and ship motion

    NARCIS (Netherlands)

    Borgerink, Dian; Stegenga, J.; Brouwer, Dannis Michel; Woertche, H.J.; Stramigioli, Stefano

    2014-01-01

    A rail-guided robotic system is currently being designed for the inspection of ballast water tanks in ships. This robotic system will manipulate sensors toward the interior walls of the tank. In this paper, the influence of rail compliance on the end-effector position error due to ship movement is

  7. A research agenda: Does geocoding positional error matter in health GIS studies?

    OpenAIRE

    Jacquez, Geoffrey

    2012-01-01

    Until recently, little attention has been paid to geocoding positional accuracy and its impacts on accessibility measures; estimates of disease rates; findings of disease clustering; spatial prediction and modeling of health outcomes; and estimates of individual exposures based on geographic proximity to pollutant and pathogen sources. It is now clear that positional errors can result in flawed findings and poor public health decisions. Yet the current state-of-practice is to ignore geocoding...

  8. Modeling the probability distribution of positional errors incurred by residential address geocoding

    OpenAIRE

    Zimmerman, Dale L.; Fang, Xiangming; Mazumdar, Soumya; Rushton, Gerard

    2007-01-01

    Background The assignment of a point-level geocode to subjects' residences is an important data assimilation component of many geographic public health studies. Often, these assignments are made by a method known as automated geocoding, which attempts to match each subject's address to an address-ranged street segment georeferenced within a streetline database and then interpolate the position of the address along that segment. Unfortunately, this process results in positional errors. Our stu...

  9. Effect of endorectal balloon positioning errors on target deformation and dosimetric quality during prostate SBRT

    Science.gov (United States)

    Jones, Bernard L.; Gan, Gregory; Kavanagh, Brian; Miften, Moyed

    2013-11-01

    An inflatable endorectal balloon (ERB) is often used during stereotactic body radiation therapy (SBRT) for treatment of prostate cancer in order to reduce both intrafraction motion of the target and risk of rectal toxicity. However, the ERB can exert significant force on the prostate, and this work assessed the impact of ERB position errors on deformation of the prostate and treatment dose metrics. Seventy-one cone-beam computed tomography (CBCT) image datasets of nine patients with clinical stage T1cN0M0 prostate cancer were studied. An ERB (Flexi-Cuff, EZ-EM, Westbury, NY) inflated with 60 cm3 of air was used during simulation and treatment, and daily kilovoltage (kV) CBCT imaging was performed to localize the prostate. The shape of the ERB in each CBCT was analyzed to determine errors in position, size, and shape. A deformable registration algorithm was used to track the dose received by (and deformation of) the prostate, and dosimetric values such as D95, PTV coverage, and Dice coefficient for the prostate were calculated. The average balloon position error was 0.5 cm in the inferior direction, with errors ranging from 2 cm inferiorly to 1 cm superiorly. The prostate was deformed primarily in the AP direction, and tilted primarily in the anterior-posterior/superior-inferior plane. A significant correlation was seen between errors in depth of ERB insertion (DOI) and mean voxel-wise deformation, prostate tilt, Dice coefficient, and planning-to-treatment prostate inter-surface distance (p < 0.001). Dosimetrically, DOI is negatively correlated with prostate D95 and PTV coverage (p < 0.001). For the model of ERB studied, error in ERB position can cause deformations in the prostate that negatively affect treatment, and this additional aspect of setup error should be considered when ERBs are used for prostate SBRT. Before treatment, the ERB position should be verified, and the ERB should be adjusted if the error is observed to exceed tolerable values.

  10. Consequences of EEG electrode position error on ultimate beamformer source reconstruction performance

    Directory of Open Access Journals (Sweden)

    Sarang S Dalal

    2014-03-01

    Full Text Available Inaccuracy of EEG electrode coordinates forms an error term in forward model generation and ultimate source reconstruction performance. This error arises from the combination of both intrinsic measurement noise of the digitization apparatus and manual coregistration error when selecting corresponding points on anatomical MRI volumes. A common assumption is that such an error would lead only to displacement of localized sources. Here, we measured electrode positions on a 3D-printed full-scale replica head, using three different techniques: a fringe projection 3D scanner, a novel Flying Triangulation 3D sensor, and a traditional electromagnetic digitizer. Using highly accurate fringe projection data as ground truth, the Flying Triangulation sensor had a mean error of 1.5 mm while the electromagnetic digitizer had a mean error of 6.8 mm. Then, again using the fringe projection as ground truth, individual EEG simulations were generated, with source locations across the brain space and a range of sensor noise levels. The simulated datasets were then processed using a beamformer in conjunction with the electrode coordinates registered with the Flying Triangulation and electromagnetic digitizer methods. The beamformer’s output SNR was severely degraded with the digitizer-based positions but less severely with the Flying Triangulation coordinates. Therefore, the seemingly innocuous error in electrode registration may result in substantial degradation of beamformer performance, with output SNR penalties up to several decibels. In the case of low-SNR signals such as deeper brain structures or gamma band sources, this implies that sensor coregistration accuracy could make the difference between successful detection of such activity or complete failure to resolve the source.

  11. Direct focusing error correction with ring-wide TBT beam position data

    CERN Document Server

    Yang, M J

    2012-01-01

    Turn-By-Turn (TBT) betatron oscillation data is a very powerful tool in studying machine optics. Hundreds and thousands of turns of free oscillations are taken in just few tens of milliseconds. With beam covering all positions and angles at every location TBT data can be used to diagnose focusing errors almost instantly. This paper describes a new approach that observes focusing error collectively over all available TBT data to find the optimized quadrupole strength, one location at a time. Example will be shown and other issues will be discussed.

  12. Subjective competence breeds overconfidence in errors in psychosis. A hubris account of paranoia.

    Science.gov (United States)

    Moritz, Steffen; Göritz, Anja S; Gallinat, Jürgen; Schafschetzy, Milena; Van Quaquebeke, Niels; Peters, Maarten J V; Andreou, Christina

    2015-09-01

    Overconfidence in errors is a well-replicated cognitive bias in psychosis. However, prior studies have sometimes failed to find differences between patients and controls for more difficult tasks. We pursued the hypothesis that overconfidence in errors is exaggerated in participants with a liability to psychosis relative to controls only when they feel competent in the respective topic and/or deem the question easy. Whereas subjective competence likely enhances confidence in those with low psychosis liability as well, we still expected to find more 'residual' caution in the latter group. We adopted a psychometric high-risk approach to circumvent the confounding influence of treatment. A total of 2321 individuals from the general population were administered a task modeled after the "Who wants to be a millionaire" quiz. Participants were requested to endorse one out of four response options, graded for confidence, and were asked to provide ratings regarding subjective competence for the knowledge domain as well as the subjective difficulty of each item. In line with our assumption, overconfidence in errors was increased overall in participants scoring high on the Paranoia Checklist core paranoia subscale (2 SD above the mean). This pattern of results was particularly prominent for items for which participants considered themselves competent and which they rated as easy. Results need to be replicated in a clinical sample. In support of our hypothesis, subjective competence and task difficulty moderate overconfidence in errors in psychosis. Trainings that teach patients the fallibility of human cognition may help reduce delusional ideation. Copyright © 2015. Published by Elsevier Ltd.

  13. Early math and reading achievement are associated with the error positivity.

    Science.gov (United States)

    Kim, Matthew H; Grammer, Jennie K; Marulis, Loren M; Carrasco, Melisa; Morrison, Frederick J; Gehring, William J

    2016-12-01

    Executive functioning (EF) and motivation are associated with academic achievement and error-related ERPs. The present study explores whether early academic skills predict variability in the error-related negativity (ERN) and error positivity (Pe). Data from 113 three- to seven-year-old children in a Go/No-Go task revealed that stronger early reading and math skills predicted a larger Pe. Closer examination revealed that this relation was quadratic and significant for children performing at or near grade level, but not significant for above-average achievers. Early academics did not predict the ERN. These findings suggest that the Pe - which reflects individual differences in motivational processes as well as attention - may be associated with early academic achievement. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Positive phase error from parallel conductance in tetrapolar bio-impedance measurements and its compensation

    Directory of Open Access Journals (Sweden)

    Ivan M Roitt

    2010-01-01

    Full Text Available Bioimpedance measurements are of great use and can provide considerable insight into biological processes.  However, there are a number of possible sources of measurement error that must be considered.  The most dominant source of error is found in bipolar measurements where electrode polarisation effects are superimposed on the true impedance of the sample.  Even with the tetrapolar approach that is commonly used to circumvent this issue, other errors can persist. Here we characterise the positive phase and rise in impedance magnitude with frequency that can result from the presence of any parallel conductive pathways in the measurement set-up.  It is shown that fitting experimental data to an equivalent electrical circuit model allows for accurate determination of the true sample impedance as validated through finite element modelling (FEM of the measurement chamber.  Finally, the model is used to extract dispersion information from cell cultures to characterise their growth.

  15. Early math and reading achievement are associated with the error positivity

    Directory of Open Access Journals (Sweden)

    Matthew H. Kim

    2016-12-01

    Full Text Available Executive functioning (EF and motivation are associated with academic achievement and error-related ERPs. The present study explores whether early academic skills predict variability in the error-related negativity (ERN and error positivity (Pe. Data from 113 three- to seven-year-old children in a Go/No-Go task revealed that stronger early reading and math skills predicted a larger Pe. Closer examination revealed that this relation was quadratic and significant for children performing at or near grade level, but not significant for above-average achievers. Early academics did not predict the ERN. These findings suggest that the Pe – which reflects individual differences in motivational processes as well as attention – may be associated with early academic achievement.

  16. Characterization of positional errors and their influence on micro four-point probe measurements on a 100 nm Ru film

    DEFF Research Database (Denmark)

    Kjær, Daniel; Hansen, Ole; Østerberg, Frederik Westergaard;

    2015-01-01

    Thin-film sheet resistance measurements at high spatial resolution and on small pads are important and can be realized with micrometer-scale four-point probes. As a result of the small scale the measurements are affected by electrode position errors. We have characterized the electrode position...... errors in measurements on Ru thin film using an Au-coated 12-point probe. We show that the standard deviation of the static electrode position error is on the order of 5 nm, which significantly affects the results of single configuration measurements. Position-error-corrected dual......-configuration measurements, however, are shown to eliminate the effect of position errors to a level limited either by electrical measurement noise or dynamic position errors. We show that the probe contact points remain almost static on the surface during the measurements (measured on an atomic scale) with a standard...

  17. Direct focusing error correction with ring-wide TBT beam position data

    Energy Technology Data Exchange (ETDEWEB)

    Yang, M.J.; /Fermilab

    2011-03-01

    Turn-By-Turn (TBT) betatron oscillation data is a very powerful tool in studying machine optics. Hundreds and thousands of turns of free oscillations are taken in just few tens of milliseconds. With beam covering all positions and angles at every location TBT data can be used to diagnose focusing errors almost instantly. This paper describes a new approach that observes focusing error collectively over all available TBT data to find the optimized quadrupole strength, one location at a time. Example will be shown and other issues will be discussed. The procedure presented clearly has helped to reduce overall deviations significantly, with relative ease. Sextupoles, being a permanent feature of the ring, will need to be incorporated into the model. While cumulative effect from all sextupoles around the ring may be negligible on turn-to-turn basis it is not so in this transfer line analysis. It should be noted that this procedure is not limited to looking for quadrupole errors. By modifying the target of minimization it could in principle be used to look for skew quadrupole errors and sextupole errors as well.

  18. Standard Positioning Performance Evaluation of a Single-Frequency GPS Receiver Implementing Ionospheric and Tropospheric Error Corrections

    Directory of Open Access Journals (Sweden)

    Alban Rakipi

    2015-03-01

    Full Text Available This paper evaluates the positioning performance of a single-frequency software GPS receiver using Ionospheric and Tropospheric corrections. While a dual-frequency user has the ability to eliminate the ionosphere error by taking a linear combination of observables, a single-frequency user must remove or calibrate this error by other means. To remove the ionosphere error we take advantage of the Klobuchar correction model, while for troposphere error mitigation the Hopfield correction model is used. Real GPS measurements were gathered using a single frequency receiver and post–processed by our proposed adaptive positioning algorithm. The integrated Klobuchar and Hopfield error correction models yeild a considerable reduction of the vertical error. The positioning algorithm automatically combines all available GPS pseudorange measurements when more than four satellites are in use. Experimental results show that improved standard positioning is achieved after error mitigation.

  19. Estimation of the parameter error propagation in inversion based BRDF observations at single sun position

    Institute of Scientific and Technical Information of China (English)

    李小文; 高峰; 王锦地; A.H.Strahler; W.Lucht; C.Schaaf

    2000-01-01

    In multiangular remote sensing observations, the variable range of the solar zenith angle (SZN) is narrow. We takes the linear kernel-driven model as an example to analyze the parameter error propagation in inversion by using the observations at single sun position and to show that in such case it is unreliable to invert the BRDF tendency with SZN. To improve the algorithm, we suggest adding certain constraint for the changing trend of albedo with SZN in the model inversion.

  20. Positioning Error of Optoelectronic Telescope Compensated by Bipolar PWM Driving Mode

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-yan; ZHOU Hui; FU Hong; HOU Yun-hai

    2005-01-01

    The optoelectronic telescope has two sets of control systems: azimuth one and elevation one, and both are driven by PWM power amplifier with high efficiency and wide speed regulation range. The diagram of the azimuth control system is demonstrated, the nonlinear factors is analyzed at low speed, and some related experiments are carried out. The results show that the positioning error with unipolar is 86 codes(106.21″),while 18 codes (22. 23″) is with bipolar PWM driver.

  1. Relativistic positioning: errors due to uncertainties in the satellite world lines

    CERN Document Server

    Puchades, Neus

    2014-01-01

    Global navigation satellite systems use appropriate satellite constellations to get the coordinates of an user -close to Earth- in an almost inertial reference system. We have simulated both GPS and GALILEO constellations. Uncertainties in the satellite world lines lead to dominant positioning errors. In this paper, a detailed analysis of these errors is developed inside a great region surrounding Earth. This analysis is performed in the framework of the so-called relativistic positioning systems. Our study is based on the Jacobian, J, of the transformation giving the emission coordinates in terms of the inertial ones. Around points of vanishing J, positioning errors are too large. We show that, for any 4-tuple of satellites, the points with J=0 are located at distances, D, from the Earth centre greater than about 2R/3, where R is the radius of the satellite orbits which are assumed to be circumferences. Our results strongly suggest that, for D-distances greater than 2R/3 and smaller than 100000 km, a rather ...

  2. Testing the Motor Simulation Account of Source Errors for Actions in Recall

    Directory of Open Access Journals (Sweden)

    Nicholas Lange

    2017-09-01

    Full Text Available Observing someone else perform an action can lead to false memories of self-performance – the observation inflation effect. One explanation is that action simulation via mirror neuron activation during action observation is responsible for observation inflation by enriching memories of observed actions with motor representations. In three experiments we investigated this account of source memory failures, using a novel paradigm that minimized influences of verbalization and prior object knowledge. Participants worked in pairs to take turns acting out geometric shapes and letters. The next day, participants recalled either actions they had performed or those they had observed. Experiment 1 showed that participants falsely retrieved observed actions as self-performed, but also retrieved self-performed actions as observed. Experiment 2 showed that preventing participants from encoding observed actions motorically by taxing their motor system with a concurrent motor task did not lead to the predicted decrease in false claims of self-performance. Indeed, Experiment 3 showed that this was the case even if participants were asked to carefully monitor their recall. Because our data provide no evidence for a motor activation account, we also discussed our results in light of a source monitoring account.

  3. Accounting for measurement error in biomarker data and misclassification of subtypes in the analysis of tumor data.

    Science.gov (United States)

    Nevo, Daniel; Zucker, David M; Tamimi, Rulla M; Wang, Molin

    2016-12-30

    A common paradigm in dealing with heterogeneity across tumors in cancer analysis is to cluster the tumors into subtypes using marker data on the tumor, and then to analyze each of the clusters separately. A more specific target is to investigate the association between risk factors and specific subtypes and to use the results for personalized preventive treatment. This task is usually carried out in two steps-clustering and risk factor assessment. However, two sources of measurement error arise in these problems. The first is the measurement error in the biomarker values. The second is the misclassification error when assigning observations to clusters. We consider the case with a specified set of relevant markers and propose a unified single-likelihood approach for normally distributed biomarkers. As an alternative, we consider a two-step procedure with the tumor type misclassification error taken into account in the second-step risk factor analysis. We describe our method for binary data and also for survival analysis data using a modified version of the Cox model. We present asymptotic theory for the proposed estimators. Simulation results indicate that our methods significantly lower the bias with a small price being paid in terms of variance. We present an analysis of breast cancer data from the Nurses' Health Study to demonstrate the utility of our method. Copyright © 2016 John Wiley & Sons, Ltd.

  4. A machine learning approach to the accurate prediction of multi-leaf collimator positional errors

    Science.gov (United States)

    Carlson, Joel N. K.; Park, Jong Min; Park, So-Yeon; In Park, Jong; Choi, Yunseok; Ye, Sung-Joon

    2016-03-01

    Discrepancies between planned and delivered movements of multi-leaf collimators (MLCs) are an important source of errors in dose distributions during radiotherapy. In this work we used machine learning techniques to train models to predict these discrepancies, assessed the accuracy of the model predictions, and examined the impact these errors have on quality assurance (QA) procedures and dosimetry. Predictive leaf motion parameters for the models were calculated from the plan files, such as leaf position and velocity, whether the leaf was moving towards or away from the isocenter of the MLC, and many others. Differences in positions between synchronized DICOM-RT planning files and DynaLog files reported during QA delivery were used as a target response for training of the models. The final model is capable of predicting MLC positions during delivery to a high degree of accuracy. For moving MLC leaves, predicted positions were shown to be significantly closer to delivered positions than were planned positions. By incorporating predicted positions into dose calculations in the TPS, increases were shown in gamma passing rates against measured dose distributions recorded during QA delivery. For instance, head and neck plans with 1%/2 mm gamma criteria had an average increase in passing rate of 4.17% (SD  =  1.54%). This indicates that the inclusion of predictions during dose calculation leads to a more realistic representation of plan delivery. To assess impact on the patient, dose volumetric histograms (DVH) using delivered positions were calculated for comparison with planned and predicted DVHs. In all cases, predicted dose volumetric parameters were in closer agreement to the delivered parameters than were the planned parameters, particularly for organs at risk on the periphery of the treatment area. By incorporating the predicted positions into the TPS, the treatment planner is given a more realistic view of the dose distribution as it will truly be

  5. 2D position sensitive microstrip sensors with charge division along the strip: Studies on the position measurement error

    Energy Technology Data Exchange (ETDEWEB)

    Bassignana, D. [Centro Nacional de Microelectrónica de Barcelona IMB-CNM (CSIC), Campus Univ. Autónoma de Barcelona, 08193 Bellaterra (Spain); Curras, E.; Fernandez, M.; Jaramillo, R. [Instituto de Física de Cantabria IFCA (CSIC-UC), Avd. de los Castros s/n, 39005 Santander (Spain); Lozano, M. [Centro Nacional de Microelectrónica de Barcelona IMB-CNM (CSIC), Campus Univ. Autónoma de Barcelona, 08193 Bellaterra (Spain); Munoz, F.J. [Instituto de Física de Cantabria IFCA (CSIC-UC), Avd. de los Castros s/n, 39005 Santander (Spain); Pellegrini, G.; Quirion, D. [Centro Nacional de Microelectrónica de Barcelona IMB-CNM (CSIC), Campus Univ. Autónoma de Barcelona, 08193 Bellaterra (Spain); Vila, I., E-mail: vila@ifca.unican.es [Instituto de Física de Cantabria IFCA (CSIC-UC), Avd. de los Castros s/n, 39005 Santander (Spain); Vitorero, F. [Instituto de Física de Cantabria IFCA (CSIC-UC), Avd. de los Castros s/n, 39005 Santander (Spain)

    2013-12-21

    Position sensitivity in semiconductor detectors of ionizing radiation is usually achieved by the segmentation of the sensing diode junction in many small sensing elements read out separately as in the case of conventional microstrips and pixel detectors. Alternatively, position sensitivity can be obtained by splitting the ionization signal collected by one single electrode amongst more than one readout channel with the ratio of the collected charges depending on the position where the signal was primary generated. Following this later approach, we implemented the charge division method in a conventional microstrip detector to obtain position sensitivity along the strip. We manufactured a proof-of-concept demonstrator where the conventional aluminum electrodes were replaced by slightly resistive electrodes made of strongly doped poly-crystalline silicon and being readout at both strip ends. Here, we partially summarize the laser characterization of this first proof-of-concept demonstrator with special emphasis on the study on how the different noise sources are affecting the device position error along the strip.

  6. Random errors for the measurement of central positions in white-light interferometry with the least-squares method.

    Science.gov (United States)

    Wang, Qi

    2015-08-01

    This paper analyzes the effect of random noise on the measurement of central positions of white-light correlograms with the least-squares method. Measurements of two types of central positions, the central position of the envelope (CPE) and the central position of the central fringe (CPCF), are investigated. Two types of random noise, intensity noise and position noise, are considered. Analytic expressions for random error due to intensity noise (REIN) and random error due to position noise (REPN) are derived. The theoretical results are compared with the random errors estimated from computer simulations. Random errors of CPE measurement are compared with those of CPCF measurement. Relationships are investigated between the random errors and the wavelength of the light source. The REPN of CPCF measurement has been found to be independent of the wavelength of the light source and the amplitude of the central fringe.

  7. Positional accommodative intraocular lens power error induced by the estimation of the corneal power and the effective lens position

    Directory of Open Access Journals (Sweden)

    David P Piñero

    2015-01-01

    Full Text Available Purpose: To evaluate the predictability of the refractive correction achieved with a positional accommodating intraocular lenses (IOL and to develop a potential optimization of it by minimizing the error associated with the keratometric estimation of the corneal power and by developing a predictive formula for the effective lens position (ELP. Materials and Methods: Clinical data from 25 eyes of 14 patients (age range, 52-77 years and undergoing cataract surgery with implantation of the accommodating IOL Crystalens HD (Bausch and Lomb were retrospectively reviewed. In all cases, the calculation of an adjusted IOL power (P IOLadj based on Gaussian optics considering the residual refractive error was done using a variable keratometric index value (n kadj for corneal power estimation with and without using an estimation algorithm for ELP obtained by multiple regression analysis (ELP adj . P IOLadj was compared to the real IOL power implanted (P IOLReal , calculated with the SRK-T formula and also to the values estimated by the Haigis, HofferQ, and Holladay I formulas. Results: No statistically significant differences were found between P IOLReal and P IOLadj when ELP adj was used (P = 0.10, with a range of agreement between calculations of 1.23 D. In contrast, P IOLReal was significantly higher when compared to P IOLadj without using ELP adj and also compared to the values estimated by the other formulas. Conclusions: Predictable refractive outcomes can be obtained with the accommodating IOL Crystalens HD using a variable keratometric index for corneal power estimation and by estimating ELP with an algorithm dependent on anatomical factors and age.

  8. Estimation of the parameter error propagation in inversion based BRDF observations at single sun position

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In multiangular remote sensing observations,the variable range of the solar zenith angle (SZN) is narrow.We takes the linear kernel-driven model as an example to analyze the parameter error propagation in inversion by using the observations at single sun position and to show that in such case it is unreliable to invert the BRDF tendency with SZN.To improve the algorithm,we suggest adding certain constraint for the changing trend of albedo with SZN in the model inversion.

  9. Investigation of the effects of correlated measurement errors in time series analysis techniques applied to nuclear material accountancy data. [Program COVAR

    Energy Technology Data Exchange (ETDEWEB)

    Pike, D.H.; Morrison, G.W.; Downing, D.J.

    1982-04-01

    It has been shown in previous work that the Kalman Filter and Linear Smoother produces optimal estimates of inventory and loss from a material balance area. The assumptions of the Kalman Filter/Linear Smoother approach assume no correlation between inventory measurement error nor does it allow for serial correlation in these measurement errors. The purpose of this report is to extend the previous results by relaxing these assumptions to allow for correlation of measurement errors. The results show how to account for correlated measurement errors in the linear system model of the Kalman Filter/Linear Smoother. An algorithm is also included for calculating the required error covariance matrices.

  10. A novel method of systematic error compensation for a position and orientation system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel method is introduced for self-calibration and elimination of systematic errors for a position and orientation system (POS). The method uses a combined bundle block adjustment with POS data (named the POS-supported bundle block adjustment) without a calibration field. On the basis of delivering strict observation equations for POS data, the specific scheme of compensating the translation and drift systematic errors in a POS is given, and a prototype system WuCAPS is developed. The effects of eliminating POS systematic errors using the POS-supported bundle block adjustment for different ground control conditions are tested using two sets of actual aerial photos. The first set was taken over a flat region in the suburbs of the city of Yingkou in China and tested at a scale of 1:2500. The second set was taken over a high mountainous region in the desert region of Xinjiang in China and tested at a scale of I :32,000. The empirical results verified that the POS systematic errors can be completely eliminated and the photo elements of exterior orientation obtained by the POS-supported bundle block adjustment can satisfy the requirements of aerial photogrammetric topographic mapping when four full ground control points (GCPs) are emplaced in the comers of the adjustment block for large-scale images of flat regions, but only one full GCP emplaced in the center of the adjustment block is needed for medium-small scale images of mountainous regions. This not only demonstrates the validity of the established mathematical model and the feasibility of the method proposed in this paper, but also avoids the use of a special calibration field. Therefore, it can simplify the existing POS operation rules and dramatically save on practical appli- cation costs, laying the theoretical foundation for widespread use of POS.

  11. Prediction of position estimation errors for 3D target trajetories estimated from cone-beam CT projections

    DEFF Research Database (Denmark)

    Poulsen, Per Rugaard; Cho, Byungchul; Keall, Paul

    2010-01-01

    . The mathematical formalism of the method includes an individualized measure of the position estimation error in terms of an estimated 1D Gaussian distribution for the unresolved target position[2]. The present study investigates how well this 1D Gaussian predicts the actual distribution of position estimation....... This finding indicates that individualized root-mean-square errors and 95% confidence intervals can be applied reliably to the estimated target trajectories....

  12. Sensitivity analysis of ordinary kriging to sampling and positional errors and applications in quality control

    Directory of Open Access Journals (Sweden)

    Victor Miguel Silva

    Full Text Available Abstract Data quality control programs used in the mineral industry normally define tolerance limits based on values considered as good practice or those that have previously been applied to similar deposits, although the precision and accuracy of estimates depend on a combination of geological characteristics, estimation parameters, sample spacing and data quality. This study investigates how the sample quality limits affect the estimates results. The proposed methodology is based on a series of metrics used to compare the impact on the estimates using a synthetic database with an increasing amount of error added to the original sample grades or positions, emulating different levels of precision. The proposed approach results lead to tolerance limits for the grades similar to those recommended in literature. The influence of the positional uncertainty on model estimates is at a minimum, because of the accuracy of current surveying methods that have a deviation in the order of millimeters, so its impact can be considered negligible.

  13. How personal standards perfectionism and evaluative concerns perfectionism affect the error positivity and post-error behavior with varying stimulus visibility.

    Science.gov (United States)

    Drizinsky, Jessica; Zülch, Joachim; Gibbons, Henning; Stahl, Jutta

    2016-10-01

    Error detection is required in order to correct or avoid imperfect behavior. Although error detection is beneficial for some people, for others it might be disturbing. We investigated Gaudreau and Thompson's (Personality and Individual Differences, 48, 532-537, 2010) model, which combines personal standards perfectionism (PSP) and evaluative concerns perfectionism (ECP). In our electrophysiological study, 43 participants performed a combination of a modified Simon task, an error awareness paradigm, and a masking task with a variation of stimulus onset asynchrony (SOA; 33, 67, and 100 ms). Interestingly, relative to low-ECP participants, high-ECP participants showed a better post-error accuracy (despite a worse classification accuracy) in the high-visibility SOA 100 condition than in the two low-visibility conditions (SOA 33 and SOA 67). Regarding the electrophysiological results, first, we found a positive correlation between ECP and the amplitude of the error positivity (Pe) under conditions of low stimulus visibility. Second, under the condition of high stimulus visibility, we observed a higher Pe amplitude for high-ECP-low-PSP participants than for high-ECP-high-PSP participants. These findings are discussed within the framework of the error-processing avoidance hypothesis of perfectionism (Stahl, Acharki, Kresimon, Völler, & Gibbons, International Journal of Psychophysiology, 97, 153-162, 2015).

  14. A Novel Prediction Algorithm of DR Position Error Based on Bayesian Regularization Back-propagation Neural Network

    Directory of Open Access Journals (Sweden)

    Li Honglian

    2013-07-01

    Full Text Available It is difficult to accurately reckon vehicle position for vehicle navigation system (VNS during GPS outages, a novel prediction algorithm of dead reckon (DR position error is put forward, which based on Bayesian regularization back-propagation (BRBP neural network. DR, GPS position data are first de-noised and compared at different stationary wavelet transformation (SWT decomposition level, and DR position error data are acquired after the SWT coefficients differences are reconstructed. A neural network to mimic position error property is trained with back-propagation algorithm, and the algorithm is improved for improving its generalization by Bayesian regularization theory. During GPS outages, the established prediction algorithm predictes DR position errors, and provides precise position for VNS through DR position error data updating DR position data. The simulation results show the positioning precision of the BRBP algorithm is best among the presented prediction algorithms such as simple DR and adaptive linear network, and a precise mathematical model of navigation sensors isn’t established.

  15. Positivity, discontinuity, finite resources, and nonzero error for arbitrarily varying quantum channels

    Energy Technology Data Exchange (ETDEWEB)

    Boche, H., E-mail: boche@tum.de, E-mail: janis.noetzel@tum.de; Nötzel, J., E-mail: boche@tum.de, E-mail: janis.noetzel@tum.de [Lehrstuhl für Theoretische Informationstechnik, Technische Universität München, 80290 München (Germany)

    2014-12-15

    This work is motivated by a quite general question: Under which circumstances are the capacities of information transmission systems continuous? The research is explicitly carried out on finite arbitrarily varying quantum channels (AVQCs). We give an explicit example that answers the recent question whether the transmission of messages over AVQCs can benefit from assistance by distribution of randomness between the legitimate sender and receiver in the affirmative. The specific class of channels introduced in that example is then extended to show that the unassisted capacity does have discontinuity points, while it is known that the randomness-assisted capacity is always continuous in the channel. We characterize the discontinuity points and prove that the unassisted capacity is always continuous around its positivity points. After having established shared randomness as an important resource, we quantify the interplay between the distribution of finite amounts of randomness between the legitimate sender and receiver, the (nonzero) probability of a decoding error with respect to the average error criterion and the number of messages that can be sent over a finite number of channel uses. We relate our results to the entanglement transmission capacities of finite AVQCs, where the role of shared randomness is not yet well understood, and give a new sufficient criterion for the entanglement transmission capacity with randomness assistance to vanish.

  16. Gravity field error analysis - Applications of Global Positioning System receivers and gradiometers on low orbiting platforms

    Science.gov (United States)

    Schrama, Ernst J. O.

    1991-11-01

    The concept of a Global Positioning System (GPS) receiver as a tracking facility and a gradiometer as a separate instrument on a low-orbiting platform offers a unique tool to map the earth's gravitational field with unprecedented accuracies. The former technique allows determination of the spacecraft's ephemeris at any epoch to within 3-10 cm, the latter permits the measurement of the tensor of second order derivatives of the gravity field to within 0.01 to 0.0001 Eotvos units depending on the type of gradiometer. First, a variety of error sources in gradiometry where emphasis is placed on the rotational problem pursuing as well a static as a dynamic approach is described. Next, an analytical technique is described and applied for an error analysis of gravity field parameters from gradiometer and GPS observation types. Results are discussed for various configurations proposed on Topex/Poseidon, Gravity Probe-B, and Aristoteles, indicating that GPS only solutions may be computed up to degree and order 35, 55, and 85, respectively, whereas a combined GPS/gradiometer experiment on Aristoteles may result in an acceptable solution up to degree and order 240.

  17. Positivity, discontinuity, finite resources, and nonzero error for arbitrarily varying quantum channels

    Science.gov (United States)

    Boche, H.; Nötzel, J.

    2014-12-01

    This work is motivated by a quite general question: Under which circumstances are the capacities of information transmission systems continuous? The research is explicitly carried out on finite arbitrarily varying quantum channels (AVQCs). We give an explicit example that answers the recent question whether the transmission of messages over AVQCs can benefit from assistance by distribution of randomness between the legitimate sender and receiver in the affirmative. The specific class of channels introduced in that example is then extended to show that the unassisted capacity does have discontinuity points, while it is known that the randomness-assisted capacity is always continuous in the channel. We characterize the discontinuity points and prove that the unassisted capacity is always continuous around its positivity points. After having established shared randomness as an important resource, we quantify the interplay between the distribution of finite amounts of randomness between the legitimate sender and receiver, the (nonzero) probability of a decoding error with respect to the average error criterion and the number of messages that can be sent over a finite number of channel uses. We relate our results to the entanglement transmission capacities of finite AVQCs, where the role of shared randomness is not yet well understood, and give a new sufficient criterion for the entanglement transmission capacity with randomness assistance to vanish.

  18. Impact of MLC leaf position errors on simple and complex IMRT plans for head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mu, G; Ludlum, E; Xia, P [Department of Radiation Oncology, University of California, San Francisco, CA (United States)

    2008-01-07

    The dosimetric impact of random and systematic multi-leaf collimator (MLC) leaf position errors is relatively unknown for head and neck intensity-modulated radiotherapy (IMRT) patients. In this report we studied 17 head and neck IMRT patients, including 12 treated with simple plans (<50 segments) and 5 treated with complex plans (>100 segments). Random errors (-2 to +2 mm) and systematic errors ({+-}0.5 mm and {+-}1 mm) in MLC leaf positions were introduced into the clinical plans and the resultant dose distributions were analyzed based on defined endpoint doses. The dosimetric effect was insignificant for random MLC leaf position errors up to 2 mm for both simple and complex plans. However, for systematic MLC leaf position errors, we found significant dosimetric differences between the simple and complex IMRT plans. For 1 mm systematic error, the average changes in D{sub 95%} were 4% in simple plans versus 8% in complex plans. The average changes in D{sub 0.1cc} of the spinal cord and brain stem were 4% in simple plans versus 12% in complex plans. The average changes in parotid glands were 9% in simple plans versus 13% for the complex plans. Overall, simple IMRT plans are less sensitive to leaf position errors than complex IMRT plans.

  19. Implication of spot position error on plan quality and patient safety in pencil-beam-scanning proton therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Juan; Beltran, Chris J., E-mail: beltran.chris@mayo.edu; Herman, Michael G. [Division of Medical Physics, Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota 55905 (United States)

    2014-08-15

    Purpose: To quantitatively and systematically assess dosimetric effects induced by spot positioning error as a function of spot spacing (SS) on intensity-modulated proton therapy (IMPT) plan quality and to facilitate evaluation of safety tolerance limits on spot position. Methods: Spot position errors (PE) ranging from 1 to 2 mm were simulated. Simple plans were created on a water phantom, and IMPT plans were calculated on two pediatric patients with a brain tumor of 28 and 3 cc, respectively, using a commercial planning system. For the phantom, a uniform dose was delivered to targets located at different depths from 10 to 20 cm with various field sizes from 2{sup 2} to 15{sup 2} cm{sup 2}. Two nominal spot sizes, 4.0 and 6.6 mm of 1 σ in water at isocenter, were used for treatment planning. The SS ranged from 0.5 σ to 1.5 σ, which is 2–6 mm for the small spot size and 3.3–9.9 mm for the large spot size. Various perturbation scenarios of a single spot error and systematic and random multiple spot errors were studied. To quantify the dosimetric effects, percent dose error (PDE) depth profiles and the value of percent dose error at the maximum dose difference (PDE [ΔDmax]) were used for evaluation. Results: A pair of hot and cold spots was created per spot shift. PDE[ΔDmax] is found to be a complex function of PE, SS, spot size, depth, and global spot distribution that can be well defined in simple models. For volumetric targets, the PDE [ΔDmax] is not noticeably affected by the change of field size or target volume within the studied ranges. In general, reducing SS decreased the dose error. For the facility studied, given a single spot error with a PE of 1.2 mm and for both spot sizes, a SS of 1σ resulted in a 2% maximum dose error; a SS larger than 1.25 σ substantially increased the dose error and its sensitivity to PE. A similar trend was observed in multiple spot errors (both systematic and random errors). Systematic PE can lead to noticeable hot

  20. Reducing position error signal (PES) due to disk vibration using an air shroud

    Science.gov (United States)

    He, Zhimin; Du, Chunling; Mou, Jianqiang; Ong, Eng Hong

    2008-04-01

    The advances in magnetic recording technology demand higher magnetic head positioning accuracy and faster disk rotation speed. However, the higher rotational speed of disk generates the greater flow-induced vibration known as disk flutter, which causes the increase of the track misregistration (TMR). To overcome the issue, an air shroud is presented to reduce disk vibration and position error signal (PES) for magnetic recording. Computational fluid mechanics simulations are performed to study the flow pattern surrounding a disk with an air shroud for different openings. The air-bearing stiffness and damping effects of the disk spindle assembly with an air shroud are evaluated. Based on the computational fluid dynamics (CFD) simulation, the air shroud is prototyped and the disk vibrations with and without the air shroud at different disk rotation speeds are experimentally investigated using a laser Doppler vibrometer (LDV). Significant disk vibration reductions are attained while a shroud is installed onto a disk at certain disk rotation speeds. PESs are also measured for the cases with and without an air shroud during servo implementation. Reductions of PESs are observed when an air shroud is installed at some disk rotation speeds.

  1. Impact of habitat-specific GPS positional error on detection of movement scales by first-passage time analysis.

    Science.gov (United States)

    Williams, David M; Dechen Quinn, Amy; Porter, William F

    2012-01-01

    Advances in animal tracking technologies have reduced but not eliminated positional error. While aware of such inherent error, scientists often proceed with analyses that assume exact locations. The results of such analyses then represent one realization in a distribution of possible outcomes. Evaluating results within the context of that distribution can strengthen or weaken our confidence in conclusions drawn from the analysis in question. We evaluated the habitat-specific positional error of stationary GPS collars placed under a range of vegetation conditions that produced a gradient of canopy cover. We explored how variation of positional error in different vegetation cover types affects a researcher's ability to discern scales of movement in analyses of first-passage time for white-tailed deer (Odocoileus virginianus). We placed 11 GPS collars in 4 different vegetative canopy cover types classified as the proportion of cover above the collar (0-25%, 26-50%, 51-75%, and 76-100%). We simulated the effect of positional error on individual movement paths using cover-specific error distributions at each location. The different cover classes did not introduce any directional bias in positional observations (1 m≤mean≤6.51 m, 0.24≤p≤0.47), but the standard deviation of positional error of fixes increased significantly with increasing canopy cover class for the 0-25%, 26-50%, 51-75% classes (SD = 2.18 m, 3.07 m, and 4.61 m, respectively) and then leveled off in the 76-100% cover class (SD = 4.43 m). We then added cover-specific positional errors to individual deer movement paths and conducted first-passage time analyses on the noisy and original paths. First-passage time analyses were robust to habitat-specific error in a forest-agriculture landscape. For deer in a fragmented forest-agriculture environment, and species that move across similar geographic extents, we suggest that first-passage time analysis is robust with regard to positional errors.

  2. Impact of habitat-specific GPS positional error on detection of movement scales by first-passage time analysis.

    Directory of Open Access Journals (Sweden)

    David M Williams

    Full Text Available Advances in animal tracking technologies have reduced but not eliminated positional error. While aware of such inherent error, scientists often proceed with analyses that assume exact locations. The results of such analyses then represent one realization in a distribution of possible outcomes. Evaluating results within the context of that distribution can strengthen or weaken our confidence in conclusions drawn from the analysis in question. We evaluated the habitat-specific positional error of stationary GPS collars placed under a range of vegetation conditions that produced a gradient of canopy cover. We explored how variation of positional error in different vegetation cover types affects a researcher's ability to discern scales of movement in analyses of first-passage time for white-tailed deer (Odocoileus virginianus. We placed 11 GPS collars in 4 different vegetative canopy cover types classified as the proportion of cover above the collar (0-25%, 26-50%, 51-75%, and 76-100%. We simulated the effect of positional error on individual movement paths using cover-specific error distributions at each location. The different cover classes did not introduce any directional bias in positional observations (1 m≤mean≤6.51 m, 0.24≤p≤0.47, but the standard deviation of positional error of fixes increased significantly with increasing canopy cover class for the 0-25%, 26-50%, 51-75% classes (SD = 2.18 m, 3.07 m, and 4.61 m, respectively and then leveled off in the 76-100% cover class (SD = 4.43 m. We then added cover-specific positional errors to individual deer movement paths and conducted first-passage time analyses on the noisy and original paths. First-passage time analyses were robust to habitat-specific error in a forest-agriculture landscape. For deer in a fragmented forest-agriculture environment, and species that move across similar geographic extents, we suggest that first-passage time analysis is robust with regard to

  3. Errors in the calculation of new salary positions and performance premiums – 2017 MERIT exercise

    CERN Multimedia

    Staff Association

    2017-01-01

    Following the receipt of the letters dated May 12th announcing the qualification of their performance (MERIT 2017), and the notification of their salary slips for the month of May, several colleagues have come to us to enquire about the calculation of salary increases and performance premiums. After verification, the Staff Association has informed the Management, in a meeting of the Standing Concertation Committee on June 1st, about errors owing to rounding in the applied formulas. James Purvis, Head of HR department, has published in the CERN Bulletin dated July 18th an article, under the heading “Better precision (rounding)”, that gives a short explanation of these rounding effects. But we want to further bring you more precise explanations. Advancement On the salary slips for the month of May, the calculations of the advancement and new salary positions were done, by the services of administrative computing in the FAP department, on the basis of the salary, rounded to the nearest franc...

  4. Automatic detection of MLC relative position errors for VMAT using the EPID-based picket fence test

    Science.gov (United States)

    Christophides, Damianos; Davies, Alex; Fleckney, Mark

    2016-12-01

    Multi-leaf collimators (MLCs) ensure the accurate delivery of treatments requiring complex beam fluences like intensity modulated radiotherapy and volumetric modulated arc therapy. The purpose of this work is to automate the detection of MLC relative position errors  ⩾0.5 mm using electronic portal imaging device-based picket fence tests and compare the results to the qualitative assessment currently in use. Picket fence tests with and without intentional MLC errors were measured weekly on three Varian linacs. The picket fence images analysed covered a time period ranging between 14-20 months depending on the linac. An algorithm was developed that calculated the MLC error for each leaf-pair present in the picket fence images. The baseline error distributions of each linac were characterised for an initial period of 6 months and compared with the intentional MLC errors using statistical metrics. The distributions of median and one-sample Kolmogorov-Smirnov test p-value exhibited no overlap between baseline and intentional errors and were used retrospectively to automatically detect MLC errors in routine clinical practice. Agreement was found between the MLC errors detected by the automatic method and the fault reports during clinical use, as well as interventions for MLC repair and calibration. In conclusion the method presented provides for full automation of MLC quality assurance, based on individual linac performance characteristics. The use of the automatic method has been shown to provide early warning for MLC errors that resulted in clinical downtime.

  5. Modeling Distance and Bandwidth Dependency of TOA-Based UWB Ranging Error for Positioning

    NARCIS (Netherlands)

    Bellusci, G.; Janssen, G.J.M.; Yan, J.; Tiberius, C.C.J.M.

    2009-01-01

    A statistical model for the range error provided by TOA estimation using UWB signals is given, based on UWB channel measurements between 3.1 and 10.6 GHz. The range error has been modeled as a Gaussian random variable for LOS and as a combination of a Gaussian and an exponential random variable for

  6. Effects of Past and Recent Blood Pressure and Cholesterol Level on Coronary Heart Disease and Stroke Mortality, Accounting for Measurement Error - Reply ( letter to the editor

    NARCIS (Netherlands)

    Boshuizen, H.C.; Lanti, M.; Menotti, A.; Moschandreas, J.; Tolonen, H.; Nissinen, A.; Nedeljkovic, S.; Kafatos, A.; Kromhout, D.

    2008-01-01

    The authors aimed to quantify the effects of current systolic blood pressure (SBP) and serum total cholesterol on the risk of mortality in comparison with SBP or serum cholesterol 25 years previously, taking measurement error into account. The authors reanalyzed 35-year follow-up data on mortality d

  7. Effects of Past and Recent Blood Pressure and Cholesterol Level on Coronary Heart Disease and Stroke Mortality, Accounting for Measurement Error

    NARCIS (Netherlands)

    Boshuizen, H.C.; Lanti, M.; Menotti, A.; Moschandreas, J.; Tolonen, H.; Nissinen, A.; Nedeljkovic, S.; Kafatos, A.; Kromhout, D.

    2007-01-01

    The authors aimed to quantify the effects of current systolic blood pressure (SBP) and serum total cholesterol on the risk of mortality in comparison with SBP or serum cholesterol 25 years previously, taking measurement error into account. The authors reanalyzed 35-year follow-up data on mortality d

  8. Effects of Past and Recent Blood Pressure and Cholesterol Level on Coronary Heart Disease and Stroke Mortality, Accounting for Measurement Error - Reply ( letter to the editor

    NARCIS (Netherlands)

    Boshuizen, H.C.; Lanti, M.; Menotti, A.; Moschandreas, J.; Tolonen, H.; Nissinen, A.; Nedeljkovic, S.; Kafatos, A.; Kromhout, D.

    2008-01-01

    The authors aimed to quantify the effects of current systolic blood pressure (SBP) and serum total cholesterol on the risk of mortality in comparison with SBP or serum cholesterol 25 years previously, taking measurement error into account. The authors reanalyzed 35-year follow-up data on mortality

  9. Effects of Past and Recent Blood Pressure and Cholesterol Level on Coronary Heart Disease and Stroke Mortality, Accounting for Measurement Error

    NARCIS (Netherlands)

    Boshuizen, H.C.; Lanti, M.; Menotti, A.; Moschandreas, J.; Tolonen, H.; Nissinen, A.; Nedeljkovic, S.; Kafatos, A.; Kromhout, D.

    2007-01-01

    The authors aimed to quantify the effects of current systolic blood pressure (SBP) and serum total cholesterol on the risk of mortality in comparison with SBP or serum cholesterol 25 years previously, taking measurement error into account. The authors reanalyzed 35-year follow-up data on mortality d

  10. Effects of Past and Recent Blood Pressure and Cholesterol Level on Coronary Heart Disease and Stroke Mortality, Accounting for Measurement Error - Reply ( letter to the editor

    NARCIS (Netherlands)

    Boshuizen, H.C.; Lanti, M.; Menotti, A.; Moschandreas, J.; Tolonen, H.; Nissinen, A.; Nedeljkovic, S.; Kafatos, A.; Kromhout, D.

    2008-01-01

    The authors aimed to quantify the effects of current systolic blood pressure (SBP) and serum total cholesterol on the risk of mortality in comparison with SBP or serum cholesterol 25 years previously, taking measurement error into account. The authors reanalyzed 35-year follow-up data on mortality d

  11. Monitoring daily MLC positional errors using trajectory log files and EPID measurements for IMRT and VMAT deliveries

    Science.gov (United States)

    Agnew, A.; Agnew, C. E.; Grattan, M. W. D.; Hounsell, A. R.; McGarry, C. K.

    2014-05-01

    This work investigated the differences between multileaf collimator (MLC) positioning accuracy determined using either log files or electronic portal imaging devices (EPID) and then assessed the possibility of reducing patient specific quality control (QC) via phantom-less methodologies. In-house software was developed, and validated, to track MLC positional accuracy with the rotational and static gantry picket fence tests using an integrated electronic portal image. This software was used to monitor MLC daily performance over a 1 year period for two Varian TrueBeam linear accelerators, with the results directly compared with MLC positions determined using leaf trajectory log files. This software was validated by introducing known shifts and collimator errors. Skewness of the MLCs was found to be 0.03 ± 0.06° (mean ±1 standard deviation (SD)) and was dependent on whether the collimator was rotated manually or automatically. Trajectory log files, analysed using in-house software, showed average MLC positioning errors with a magnitude of 0.004 ± 0.003 mm (rotational) and 0.004 ± 0.011 mm (static) across two TrueBeam units over 1 year (mean ±1 SD). These ranges, as indicated by the SD, were lower than the related average MLC positioning errors of 0.000 ± 0.025 mm (rotational) and 0.000 ± 0.039 mm (static) that were obtained using the in-house EPID based software. The range of EPID measured MLC positional errors was larger due to the inherent uncertainties of the procedure. Over the duration of the study, multiple MLC positional errors were detected using the EPID based software but these same errors were not detected using the trajectory log files. This work shows the importance of increasing linac specific QC when phantom-less methodologies, such as the use of log files, are used to reduce patient specific QC. Tolerances of 0.25 mm have been created for the MLC positional errors using the EPID-based automated picket fence test. The software allows diagnosis

  12. Square-Wave Voltage Injection Algorithm for PMSM Position Sensorless Control With High Robustness to Voltage Errors

    DEFF Research Database (Denmark)

    Ni, Ronggang; Xu, Dianguo; Blaabjerg, Frede

    2017-01-01

    relationship with the magnetic field distortion. Position estimation errors caused by higher order harmonic inductances and voltage harmonics generated by the SVPWM are also discussed. Both simulations and experiments are carried out based on a commercial PMSM to verify the superiority of the proposed method...

  13. Effects of serial position on Bender-Gestalt errors using Koppitz's criteria.

    Science.gov (United States)

    Nyfield, B; Patalano, F

    1998-12-01

    The validity of the Koppitz Developmental scoring system in identifying organic impairment among functionally impaired adolescents was challenged in the current study. It was proposed that there are two distinct subtypes of errors in this system: those that are valid indicators of organic impairment (Category A) and those which are not but occur as a function of specific emotional factors (Category B). 46 male adolescents with a primary diagnosis of Conduct Disorder, Oppositional Defiant Disorder, or Attention-Deficit Hyperactivity Disorder were administered the Bender-Gestalt once using the standard order of administration and once in reverse order. It was hypothesized that more errors would be committed on cards presented later than those presented earlier in sequence for Category B but not Category A errors. Analysis provided partial support for this hypothesis.

  14. Putamen Activation Represents an Intrinsic Positive Prediction Error Signal for Visual Search in Repeated Configurations.

    Science.gov (United States)

    Sommer, Susanne; Pollmann, Stefan

    2016-01-01

    We investigated fMRI responses to visual search targets appearing at locations that were predicted by the search context. Based on previous work in visual category learning we expected an intrinsic reward prediction error signal in the putamen whenever the target appeared at a location that was predicted with some degree of uncertainty. Comparing target appearance at locations predicted with 50% probability to either locations predicted with 100% probability or unpredicted locations, increased activation was observed in left posterior putamen and adjacent left posterior insula. Thus, our hypothesis of an intrinsic prediction error-like signal was confirmed. This extends the observation of intrinsic prediction error-like signals, driven by intrinsic rather than extrinsic reward, to memory-driven visual search.

  15. Putamen Activation Represents an Intrinsic Positive Prediction Error Signal for Visual Search in Repeated Configurations

    Science.gov (United States)

    Sommer, Susanne; Pollmann, Stefan

    2016-01-01

    We investigated fMRI responses to visual search targets appearing at locations that were predicted by the search context. Based on previous work in visual category learning we expected an intrinsic reward prediction error signal in the putamen whenever the target appeared at a location that was predicted with some degree of uncertainty. Comparing target appearance at locations predicted with 50% probability to either locations predicted with 100% probability or unpredicted locations, increased activation was observed in left posterior putamen and adjacent left posterior insula. Thus, our hypothesis of an intrinsic prediction error-like signal was confirmed. This extends the observation of intrinsic prediction error-like signals, driven by intrinsic rather than extrinsic reward, to memory-driven visual search. PMID:27867436

  16. 2D position sensitive microstrip sensors with charge division along the strip Studies on the position measurement error

    CERN Document Server

    Bassignana, D; Fernandez, M; Jaramillo, R; Lozano, M; Munoz, F.J; Pellegrini, G; Quirion, D; Vila, I; Vitorero, F

    2013-01-01

    Position sensitivity in semiconductor detectors of ionizing radiation is usually achieved by the segmentation of the sensing diode junction in many small sensing elements read out separately as in the case of conventional microstrips and pixel detectors. Alternatively, position sensitivity can be obtained by splitting the ionization signal collected by one single electrode amongst more than one readout channel with the ratio of the collected charges depending on the position where the signal was primary generated. Following this later approach, we implemented the charge division method in a conventional microstrip detector to obtain position sensitivity along the strip. We manufactured a proofof-concept demonstrator where the conventional aluminum electrodes were replaced by slightly resistive electrodes made of strongly doped poly-crystalline silicon and being readout at both strip ends. Here, we partially summarize the laser characterization of this first proof-of-concept demonstrator with special emphasis ...

  17. 2D Position Sensitive Microstrip Sensors with Charge Division Along the Strip: Studies on the position measurement error

    CERN Document Server

    Bassignana, D; Fernandez, M; Jaramillo, R; Lozano, M; Munoz, F J; Pellegrini, G; Quirion, D; Vila, I; Vitorero, F

    2013-01-01

    Position sensitivity in semiconductor detectors of ionizing radiation is usually achieved by the segmentation of the sensing diode junction in many small sensing elements read out separately as in the case of conventional microstrips and pixel detectors. Alternatively, position sensitivity can be obtained by splitting the ionization signal collected by one single electrode amongst more than one readout channel with the ratio of the collected charges depending on the position where the signal was primary generated. Following this later approach, we implemented the charge division method in a conventional microstrip detector to obtain position sensitivity along the strip. We manufactured a proof-of-concept demonstrator where the conventional aluminum electrodes were replaced by slightly resistive electrodes made of strongly doped poly-crystalline silicon and being readout at both strip ends. Here, we partially summarize the laser characterization of this first proof-of-concept demonstrator with special emphas...

  18. On minimizing assignment errors and the trade-off between false positives and negatives in parentage analysis.

    Science.gov (United States)

    Harrison, Hugo B; Saenz-Agudelo, Pablo; Planes, Serge; Jones, Geoffrey P; Berumen, Michael L

    2013-12-01

    Genetic parentage analyses provide a practical means with which to identify parent-offspring relationships in the wild. In Harrison et al.'s study (2013a), we compare three methods of parentage analysis and showed that the number and diversity of microsatellite loci were the most important factors defining the accuracy of assignments. Our simulations revealed that an exclusion-Bayes theorem method was more susceptible to false-positive and false-negative assignments than other methods tested. Here, we analyse and discuss the trade-off between type I and type II errors in parentage analyses. We show that controlling for false-positive assignments, without reporting type II errors, can be misleading. Our findings illustrate the need to estimate and report both the rate of false-positive and false-negative assignments in parentage analyses.

  19. On minimizing assignment errors and the trade-off between false positives and negatives in parentage analysis

    KAUST Repository

    Harrison, Hugo B.

    2013-11-04

    Genetic parentage analyses provide a practical means with which to identify parent-offspring relationships in the wild. In Harrison et al.\\'s study (2013a), we compare three methods of parentage analysis and showed that the number and diversity of microsatellite loci were the most important factors defining the accuracy of assignments. Our simulations revealed that an exclusion-Bayes theorem method was more susceptible to false-positive and false-negative assignments than other methods tested. Here, we analyse and discuss the trade-off between type I and type II errors in parentage analyses. We show that controlling for false-positive assignments, without reporting type II errors, can be misleading. Our findings illustrate the need to estimate and report both the rate of false-positive and false-negative assignments in parentage analyses. © 2013 John Wiley & Sons Ltd.

  20. Initiating an error budget of the DORIS ground antenna position: Genesis of the Starec antenna type C

    Science.gov (United States)

    Saunier, J.; Auriol, A.; Tourain, C.

    2016-12-01

    The DORIS system measures distances between phase centers of onboard and ground antennas to determine the position of the satellites in their orbits. To this end, the ground antenna phase center position must be known in a terrestrial reference frame. Its position is linked and defined with respect to the antenna reference point (ARP), a conventional physical point for which coordinates are assigned. Although the determination of the ARP position with respect to ground markers can be achieved by traditional surveys, the connection with the actual measurement point (phase center) is far more difficult to determine. This is the main concern explored in this paper. Regardless of the need for a good antenna characterization, CNES and IGN jointly worked to establish a first error budget of the ground antenna position. With this aim in view, each component was clearly identified and studied separately. We distinguished between errors from manufacturing and from site surveying and, on the other hand, errors affecting horizontal and vertical position. The knowledge of the antenna geometry and the guarantee of a good reproducibility in the manufacturing process are essential. Based on these requirements, we have defined new manufacturing specifications to create a new antenna type: Starec type C. Compared to the previous antenna (Starec type B), the standard uncertainty of the 2 GHz phase center position in the vertical direction has been reduced from 5 mm to 1 mm. Following this work, we provide for the new Starec antenna (type C) total uncertainties involved in the ground antenna positioning in a local reference frame: 2 mm in the horizontal plane, 2.5 mm for the vertical component and 3.2 mm in three-dimensional combination. We also propose for DORIS new definitions of conventional points and a new method to determine ground antennas position that were not possible before this manufacturing specifications change.

  1. SU-E-J-94: Positioning Errors Resulting From Using Bony Anatomy Alignment for Treating SBRT Lung Tumor

    Energy Technology Data Exchange (ETDEWEB)

    Frame, C; Ding, G [Vanderbilt University, Nashville, TN (United States)

    2014-06-01

    Purpose: To quantify patient setups errors based on bony anatomy registration rather than 3D tumor alignment for SBRT lung treatments. Method: A retrospective study was performed for patients treated with lung SBRT and imaged with kV cone beam computed tomography (kV-CBCT) image-guidance. Daily CBCT images were registered to treatment planning CTs based on bony anatomy alignment and then inter-fraction tumor movement was evaluated by comparing shift in the tumor center in the medial-lateral, anterior-posterior, and superior-inferior directions. The PTV V100% was evaluated for each patient based on the average daily tumor displacement to assess the impact of the positioning error on the target coverage when the registrations were based on bony anatomy. Of the 35 patients studied, 15 were free-breathing treatments, 10 used abdominal compression with a stereotactic body frame, and the remaining 10 were performed with BodyFIX vacuum bags. Results: For free-breathing treatments, the range of tumor displacement error is between 1–6 mm in the medial-lateral, 1–13 mm in the anterior-posterior, and 1–7 mm in the superior-inferior directions. These positioning errors lead to 6–22% underdose coverage for PTV - V100% . Patients treated with abdominal compression immobilization showed positional errors of 0–4mm mediallaterally, 0–3mm anterior-posteriorly, and 0–2 mm inferior-superiorly with PTV - V100% underdose ranging between 6–17%. For patients immobilized with the vacuum bags, the positional errors were found to be 0–1 mm medial-laterally, 0–1mm anterior-posteriorly, and 0–2 mm inferior-superiorly with PTV - V100% under dose ranging between 5–6% only. Conclusion: It is necessary to align the tumor target by using 3D image guidance to ensure adequate tumor coverage before performing SBRT lung treatments. The BodyFIX vacuum bag immobilization method has the least positioning errors among the three methods studied when bony anatomy is used for

  2. Motivational processes from expectancy-value theory are associated with variability in the error positivity in young children.

    Science.gov (United States)

    Kim, Matthew H; Marulis, Loren M; Grammer, Jennie K; Morrison, Frederick J; Gehring, William J

    2017-03-01

    Motivational beliefs and values influence how children approach challenging activities. The current study explored motivational processes from an expectancy-value theory framework by studying children's mistakes and their responses to them by focusing on two event-related potential (ERP) components: the error-related negativity (ERN) and the error positivity (Pe). Motivation was assessed using a child-friendly challenge puzzle task and a brief interview measure prior to ERP testing. Data from 50 4- to 6-year-old children revealed that greater perceived competence beliefs were related to a larger Pe, whereas stronger intrinsic task value beliefs were associated with a smaller Pe. Motivation was unrelated to the ERN. Individual differences in early motivational processes may reflect electrophysiological activity related to conscious error awareness. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. The impact of sensor errors and building structures on particle filter-based inertial positioning

    DEFF Research Database (Denmark)

    Toftkjær, Thomas; Kjærgaard, Mikkel Baun

    2012-01-01

    Positioning systems that do not depend on in-building infrastructures are critical for enabling a range of applications within pervasive computing. Particle filter-based inertial positioning promises infrastructure-less positioning, but previous research has not provided an understanding of how t...

  4. Errors in Measuring Transverse and Energy Jitter by Beam Position Monitors

    CERN Document Server

    Balandin, V; Golubeva, N

    2010-01-01

    The problem of errors, arising due to finite BPM resolution, in the difference orbit parameters, which are found as a least squares fit to the BPM data, is one of the standard and important problems of accelerator physics. Even so for the case of transversely uncoupled motion the covariance matrix of reconstruction errors can be calculated "by hand", the direct usage of obtained solution, as a tool for designing of a "good measurement system", does not look to be fairly straightforward. It seems that a better understanding of the nature of the problem is still desirable. We make a step in this direction introducing dynamic into this problem, which at the first glance seems to be static. We consider a virtual beam consisting of virtual particles obtained as a result of application of reconstruction procedure to "all possible values" of BPM reading errors. This beam propagates along the beam line according to the same rules as any real beam and has all beam dynamical characteristics, such as emittances, energy ...

  5. Minimally invasive positioning robot system of femoral neck hollow screw implants based on x-ray error correction

    Science.gov (United States)

    Zou, Yunpeng; Xu, Ying; Hu, Lei; Guo, Na; Wang, Lifeng

    2017-01-01

    Aiming the high failure rate, the high radiation quantity and the poor positioning accuracy of femoral neck traditional surgery, this article develops a set of new positioning robot system of femoral neck hollow screw implants based on X-rays error correction, which bases on the study of x-rays perspective principle and the Motion Principle of 6 DOF(degree of freedom) series robot UR(Universal Robots). Compared with Computer Assisted Navigation System, this system owns better positioning accuracy and more simple operation. In addition, without extra Equipment of Visual Tracking, this system can reduce a lot of cost. During the surgery, Doctor can plan the operation path and the pose of mark needle according to the positive and lateral X-rays images of patients. Then they can calculate the pixel ratio according to the ratio of the actual length of mark line and the length on image. After that, they can calculate the amount of exercise of UR Robot according to the relative position between operation path and guide pin and the fixed relationship between guide pin and UR robot. Then, they can control UR to drive the positioning guide pin to the operation path. At this point, check the positioning guide pin and the planning path is coincident, if not, repeat the previous steps, until the positioning guide pin and the planning path coincide which will eventually complete the positioning operation. Moreover, to verify the positioning accuracy, this paper make an errors analysis aiming to thirty cases of the experimental model of bone. The result shows that the motion accuracy of the UR Robot is 0.15mm and the Integral error precision is within 0.8mm. To verify the clinical feasibility of this system, this article analysis on three cases of the clinical experiment. In the whole process of positioning, the X-rays irradiation time is 2-3s, the number of perspective is 3-5 and the whole positioning time is 7-10min. The result shows that this system can complete accurately

  6. Verification and source-position error analysis of film reconstruction techniques used in the brachytherapy planning systems

    Energy Technology Data Exchange (ETDEWEB)

    Chang Liyun; Ho, Sheng-Yow; Chui, Chen-Shou; Du, Yi-Chun; Chen Tainsong [Institute of Biochemical Engineering, National Cheng-Kung University, Tainan 701, Taiwan (China) and Department of Radiation Oncology, Sinlau Christian Hospital, Tainan 701, Taiwan (China); Department of Radiation Oncology, Sinlau Christian Hospital, Tainan 701, Taiwan (China); Department of Medical Physics, Sun Yat-Sen Cancer Center, Taipei 112, Taiwan (China); Institute of Biomedical Engineering, National Cheng-Kung University, Tainan 701, Taiwan (China)

    2009-09-15

    A method was presented that employs standard linac QA tools to verify the accuracy of film reconstruction algorithms used in the brachytherapy planning system. Verification of reconstruction techniques is important as suggested in the ESTRO booklet 8: ''The institution should verify the full process of any reconstruction technique employed clinically.'' Error modeling was also performed to analyze seed-position errors. The ''isocentric beam checker'' device was used in this work. It has a two-dimensional array of steel balls embedded on its surface. The checker was placed on the simulator couch with its center ball coincident with the simulator isocenter, and one axis of its cross marks parallel to the axis of gantry rotation. The gantry of the simulator was rotated to make the checker behave like a three-dimensional array of balls. Three algorithms used in the ABACUS treatment planning system: orthogonal film, 2-films-with-variable-angle, and 3-films-with-variable-angle were tested. After exposing and digitizing the films, the position of each steel ball on the checker was reconstructed and compared to its true position, which can be accurately calculated. The results showed that the error is dependent on the object-isocenter distance, but not the magnification of the object. The averaged errors were less than 1 mm within the tolerance level defined by Roueet al. [''The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy,'' Radiother. Oncol. 78, 78-83 (2006)]. However, according to the error modeling, the theoretical error would be greater than 2 mm if the objects were located more than 20 cm away from the isocenter with a 0.5 deg. reading error of the gantry and collimator angles. Thus, in addition to carefully performing the QA of the gantry and collimator angle indicators, it is suggested that the patient, together with the applicators or seeds inside, should be placed close to

  7. An Implementation of Error Minimization Position Estimate in Wireless Inertial Measurement Unit using Modification ZUPT

    Directory of Open Access Journals (Sweden)

    Adytia Darmawan

    2016-12-01

    Full Text Available Position estimation using WIMU (Wireless Inertial Measurement Unit is one of emerging technology in the field of indoor positioning systems. WIMU can detect movement and does not depend on GPS signals. The position is then estimated using a modified ZUPT (Zero Velocity Update method that was using Filter Magnitude Acceleration (FMA, Variance Magnitude Acceleration (VMA and Angular Rate (AR estimation. Performance of this method was justified on a six-legged robot navigation system. Experimental result shows that the combination of VMA-AR gives the best position estimation.

  8. Residual position errors of lymph node surrogates in breast cancer adjuvant radiotherapy: Comparison of two arm fixation devices and the effect of arm position correction

    Energy Technology Data Exchange (ETDEWEB)

    Kapanen, Mika [Department of Oncology, Tampere University Hospital (TAUH), Tampere (Finland); Department of Medical Physics, Tampere University Hospital (TAUH), Tampere (Finland); Laaksomaa, Marko, E-mail: Marko.Laaksomaa@pshp.fi [Department of Oncology, Tampere University Hospital (TAUH), Tampere (Finland); Skyttä, Tanja; Haltamo, Mikko; Pehkonen, Jani; Lehtonen, Turkka [Department of Oncology, Tampere University Hospital (TAUH), Tampere (Finland); Kellokumpu-Lehtinen, Pirkko-Liisa [Department of Oncology, Tampere University Hospital (TAUH), Tampere (Finland); Medical School, University of Tampere, Tampere (Finland); Hyödynmaa, Simo [Department of Medical Physics, Tampere University Hospital (TAUH), Tampere (Finland)

    2016-04-01

    Residual position errors of the lymph node (LN) surrogates and humeral head (HH) were determined for 2 different arm fixation devices in radiotherapy (RT) of breast cancer: a standard wrist-hold (WH) and a house-made rod-hold (RH). The effect of arm position correction (APC) based on setup images was also investigated. A total of 113 consecutive patients with early-stage breast cancer with LN irradiation were retrospectively analyzed (53 and 60 using the WH and RH, respectively). Residual position errors of the LN surrogates (Th1-2 and clavicle) and the HH were investigated to compare the 2 fixation devices. The position errors and setup margins were determined before and after the APC to investigate the efficacy of the APC in the treatment situation. A threshold of 5 mm was used for the residual errors of the clavicle and Th1-2 to perform the APC, and a threshold of 7 mm was used for the HH. The setup margins were calculated with the van Herk formula. Irradiated volumes of the HH were determined from RT treatment plans. With the WH and the RH, setup margins up to 8.1 and 6.7 mm should be used for the LN surrogates, and margins up to 4.6 and 3.6 mm should be used to spare the HH, respectively, without the APC. After the APC, the margins of the LN surrogates were equal to or less than 7.5/6.0 mm with the WH/RH, but margins up to 4.2/2.9 mm were required for the HH. The APC was needed at least once with both the devices for approximately 60% of the patients. With the RH, irradiated volume of the HH was approximately 2 times more than with the WH, without any dose constraints. Use of the RH together with the APC resulted in minimal residual position errors and setup margins for all the investigated bony landmarks. Based on the obtained results, we prefer the house-made RH. However, more attention should be given to minimize the irradiation of the HH with the RH than with the WH.

  9. Hand position-dependent modulation of errors in vibrotactile temporal order judgments

    DEFF Research Database (Denmark)

    Ritterband-Rosenbaum, Anina; Hermosillo, Robert; Kroliczak, Gregory

    2014-01-01

    this confounded information is processed in the brain is poorly understood. In the present set of experiments, we addressed this knowledge gap by using singlepulse transcranial magnetic stimulation (TMS) to disrupt processing in the right or left posterior parietal cortex (PPC) during a vibrotactile TOJ task...... present with TMS over either hemisphere, regardless of arm configuration; however, they were larger overall following TMS over the right PPC. Control experiments using sham TMS indicated the systematic modulation in error was not due to nonspecific effects of the stimulation. Additionally, we showed...

  10. Methods for Estimation of Radiation Risk in Epidemiological Studies Accounting for Classical and Berkson Errors in Doses

    KAUST Repository

    Kukush, Alexander

    2011-01-16

    With a binary response Y, the dose-response model under consideration is logistic in flavor with pr(Y=1 | D) = R (1+R)(-1), R = λ(0) + EAR D, where λ(0) is the baseline incidence rate and EAR is the excess absolute risk per gray. The calculated thyroid dose of a person i is expressed as Dimes=fiQi(mes)/Mi(mes). Here, Qi(mes) is the measured content of radioiodine in the thyroid gland of person i at time t(mes), Mi(mes) is the estimate of the thyroid mass, and f(i) is the normalizing multiplier. The Q(i) and M(i) are measured with multiplicative errors Vi(Q) and ViM, so that Qi(mes)=Qi(tr)Vi(Q) (this is classical measurement error model) and Mi(tr)=Mi(mes)Vi(M) (this is Berkson measurement error model). Here, Qi(tr) is the true content of radioactivity in the thyroid gland, and Mi(tr) is the true value of the thyroid mass. The error in f(i) is much smaller than the errors in ( Qi(mes), Mi(mes)) and ignored in the analysis. By means of Parametric Full Maximum Likelihood and Regression Calibration (under the assumption that the data set of true doses has lognormal distribution), Nonparametric Full Maximum Likelihood, Nonparametric Regression Calibration, and by properly tuned SIMEX method we study the influence of measurement errors in thyroid dose on the estimates of λ(0) and EAR. The simulation study is presented based on a real sample from the epidemiological studies. The doses were reconstructed in the framework of the Ukrainian-American project on the investigation of Post-Chernobyl thyroid cancers in Ukraine, and the underlying subpolulation was artificially enlarged in order to increase the statistical power. The true risk parameters were given by the values to earlier epidemiological studies, and then the binary response was simulated according to the dose-response model.

  11. Correcting Positional Errors in Shore-Based Theodolite Measurements of Animals at Sea

    Directory of Open Access Journals (Sweden)

    Ophélie Sagnol

    2014-01-01

    Full Text Available Determining the position of animals at sea can be particularly difficult and yet, accurate range and position of animals at sea are essential to answer a wide range of biological questions. Shore-based theodolite techniques have been used in a number of studies to examine marine mammal movement patterns and habitat use, offering reliable position measurements. In this study we explored the accuracy of theodolite measurements by comparing positional information of the same objects using two independent techniques: a shore-based theodolite station and an onboard GPS over a range of 25 km from the shore-based station. The technique was developed to study the habitat use of sperm whales (Physeter macrocephalus off Kaikoura, New Zealand. We observed that the position accuracy fell rapidly with an increase in range from the shore-based station. Results showed that the horizontal angle was accurately determined, but this was not the case for the vertical angle. We calibrated the position of objects at sea with a regression-based correction to fit the difference in distance between simultaneously recorded theodolite fixes and GPS positions. This approach revealed the necessity to calibrate theodolite measurements with objects at sea of known position.

  12. Meta-analysis of gene–environment-wide association scans accounting for education level identifies additional loci for refractive error

    OpenAIRE

    Fan,Q; Verhoeven, V; Wojciechowski, R.; Barathi, V.; Hysi, P; GUGGENHEIM, J.; Höhn, R; Vitart, V; Khawaja, A; Yamashiro, K.; Hosseini, S.; Lehtimäki, T.; Lu, Y; Haller, T.; Xie, J

    2016-01-01

    Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry indi...

  13. A Statistical Method and Tool to Account for Indirect Calorimetry Differential Measurement Error in a Single-Subject Analysis.

    Science.gov (United States)

    Tenan, Matthew S

    2016-01-01

    Indirect calorimetry and oxygen consumption (VO2) are accepted tools in human physiology research. It has been shown that indirect calorimetry systems exhibit differential measurement error, where the error of a device is systematically different depending on the volume of gas flow. Moreover, systems commonly report multiple decimal places of precision, giving the clinician a false sense of device accuracy. The purpose of this manuscript is to demonstrate the use of a novel statistical tool which models the reliability of two specific indirect calorimetry systems, Douglas bag and Parvomedics 2400 TrueOne, as univariate normal distributions and implements the distribution overlapping coefficient to determine the likelihood that two VO2 measures are the same. A command line implementation of the tool is available for the R programming language as well as a web-based graphical user interface (GUI). This tool is valuable for clinicians performing a single-subject analysis as well as researchers interested in determining if their observed differences exceed the error of the device.

  14. A Statistical Method and Tool to Account for Indirect Calorimetry Differential Measurement Error in a Single-Subject Analysis

    Directory of Open Access Journals (Sweden)

    Matthew S Tenan

    2016-05-01

    Full Text Available Indirect calorimetry and oxygen consumption (VO2 are accepted tools in human physiology research. It has been shown that indirect calorimetry systems exhibit differential measurement error, where the error of a device is systematically different depending on the volume of gas flow. Moreover, systems commonly report multiple decimal places of precision, giving the clinician a false sense of device accuracy. The purpose of this manuscript is to demonstrate the use of a novel statistical tool which models the reliability of two specific indirect calorimetry systems, Douglas bag and Parvomedics 2400 TrueOne, as univariate normal distributions and implements the distribution overlapping coefficient to determine the likelihood that two VO2 measures are the same. A command line implementation of the tool is available for the R programming language as well as a web-based graphical user interface. This tool is valuable for clinicians performing a single-subject analysis as well as researchers interested in determining if their observed differences exceed the error of the device.

  15. Position Error Compensation via a Variable Reluctance Sensor Applied to a Hybrid Vehicle Electric Machine

    Directory of Open Access Journals (Sweden)

    İhsan Ömür Bucak

    2010-03-01

    Full Text Available In the automotive industry, electromagnetic variable reluctance (VR sensors have been extensively used to measure engine position and speed through a toothed wheel mounted on the crankshaft. In this work, an application that already uses the VR sensing unit for engine and/or transmission has been chosen to infer, this time, the indirect position of the electric machine in a parallel Hybrid Electric Vehicle (HEV system. A VR sensor has been chosen to correct the position of the electric machine, mainly because it may still become critical in the operation of HEVs to avoid possible vehicle failures during the start-up and on-the-road, especially when the machine is used with an internal combustion engine. The proposed method uses Chi-square test and is adaptive in a sense that it derives the compensation factors during the shaft operation and updates them in a timely fashion.

  16. Position error compensation via a variable reluctance sensor applied to a Hybrid Vehicle Electric machine.

    Science.gov (United States)

    Bucak, Ihsan Ömür

    2010-01-01

    In the automotive industry, electromagnetic variable reluctance (VR) sensors have been extensively used to measure engine position and speed through a toothed wheel mounted on the crankshaft. In this work, an application that already uses the VR sensing unit for engine and/or transmission has been chosen to infer, this time, the indirect position of the electric machine in a parallel Hybrid Electric Vehicle (HEV) system. A VR sensor has been chosen to correct the position of the electric machine, mainly because it may still become critical in the operation of HEVs to avoid possible vehicle failures during the start-up and on-the-road, especially when the machine is used with an internal combustion engine. The proposed method uses Chi-square test and is adaptive in a sense that it derives the compensation factors during the shaft operation and updates them in a timely fashion.

  17. Accounting for model error in air quality forecasts: an application of 4DEnVar to the assimilation of atmospheric composition using QG-Chem 1.0

    Science.gov (United States)

    Emili, Emanuele; Gürol, Selime; Cariolle, Daniel

    2016-11-01

    Model errors play a significant role in air quality forecasts. Accounting for them in the data assimilation (DA) procedures is decisive to obtain improved forecasts. We address this issue using a reduced-order coupled chemistry-meteorology model based on quasi-geostrophic dynamics and a detailed tropospheric chemistry mechanism, which we name QG-Chem. This model has been coupled to the software library for the data assimilation Object Oriented Prediction System (OOPS) and used to assess the potential of the 4DEnVar algorithm for air quality analyses and forecasts. The assets of 4DEnVar include the possibility to deal with multivariate aspects of atmospheric chemistry and to account for model errors of a generic type. A simple diagnostic procedure for detecting model errors is proposed, based on the 4DEnVar analysis and one additional model forecast. A large number of idealized data assimilation experiments are shown for several chemical species of relevance for air quality forecasts (O3, NOx, CO and CO2) with very different atmospheric lifetimes and chemical couplings. Experiments are done both under a perfect model hypothesis and including model error through perturbation of surface chemical emissions. Some key elements of the 4DEnVar algorithm such as the ensemble size and localization are also discussed. A comparison with results of 3D-Var, widely used in operational centers, shows that, for some species, analysis and next-day forecast errors can be halved when model error is taken into account. This result was obtained using a small ensemble size, which remains affordable for most operational centers. We conclude that 4DEnVar has a promising potential for operational air quality models. We finally highlight areas that deserve further research for applying 4DEnVar to large-scale chemistry models, i.e., localization techniques, propagation of analysis covariance between DA cycles and treatment for chemical nonlinearities. QG-Chem can provide a useful tool in this

  18. Accounting for model error in air-quality forecasts: an application of 4DEnVar to the assimilation of atmospheric composition

    Science.gov (United States)

    Emili, E.; Gürol, S.; Cariolle, D.

    2016-12-01

    Model errors play a significant role in air-quality forecasts. Accounting for them in the data assimilation (DA) procedures is decisive to obtain improved forecasts. We address this issue using a reduced-order chemical transport model based on quasi-geostrophic dynamics and a detailed tropospheric chemistry mechanism, which we name QG-Chem. This model has been coupled to a generic software library for data assimilation and used to assess the potential of the 4DEnVar algorithm for air-quality analyses and forecasts. Among the assets of 4DEnVar, we reckon the possibility to deal with multivariate aspects of atmospheric chemistry and to account for model errors of generic type. A simple diagnostic procedure for detecting model errors is proposed, based on the 4DEnVar analysis and one additional model forecast. A large number of idealized data assimilation experiments are shown for several chemical species of relevance for air-quality forecasts (O3, NOx, CO and CO2), with very different atmospheric life-times and chemical couplings. Experiments are done both under a perfect model hypothesis and including model error through perturbation of surface chemical emissions, for two meteorological and chemical regimes. Some key elements of the 4DEnVar algorithm such as the ensemble size and localization are also discussed. A comparison with results of 3D-Var, widely used in operational centers, shows that, for some species, analyses and next day forecast errors can be halved when model error is taken in account. This result was obtained using a small ensemble size, which remain affordable for most operational centers. We conclude that 4DEnVar has a promising potential for operational air-quality models. We finally highlight areas that deserve further research for applying 4DEnVar to large scale chemistry models, i.e. localization techniques, propagation of analysis covariance between DA cycles and treatment for chemical non-linearities. QG-Chem could provide a useful tool in

  19. Accounting for representativeness errors in the inversion of atmospheric constituent emissions: application to the retrieval of regional carbon monoxide fluxes

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Koohkan

    2012-07-01

    Full Text Available A four-dimensional variational data assimilation system (4D-Var is developed to retrieve carbon monoxide (CO fluxes at regional scale, using an air quality network. The air quality stations that monitor CO are proximity stations located close to industrial, urban or traffic sources. The mismatch between the coarsely discretised Eulerian transport model and the observations, inferred to be mainly due to representativeness errors in this context, lead to a bias (average simulated concentrations minus observed concentrations of the same order of magnitude as the concentrations. 4D-Var leads to a mild improvement in the bias because it does not adequately handle the representativeness issue. For this reason, a simple statistical subgrid model is introduced and is coupled to 4D-Var. In addition to CO fluxes, the optimisation seeks to jointly retrieve influence coefficients, which quantify each station's representativeness. The method leads to a much better representation of the CO concentration variability, with a significant improvement of statistical indicators. The resulting increase in the total inventory estimate is close to the one obtained from remote sensing data assimilation. This methodology and experiments suggest that information useful at coarse scales can be better extracted from atmospheric constituent observations strongly impacted by representativeness errors.

  20. Meta-analysis of gene-environment-wide association scans accounting for education level identifies additional loci for refractive error.

    Science.gov (United States)

    Fan, Qiao; Verhoeven, Virginie J M; Wojciechowski, Robert; Barathi, Veluchamy A; Hysi, Pirro G; Guggenheim, Jeremy A; Höhn, René; Vitart, Veronique; Khawaja, Anthony P; Yamashiro, Kenji; Hosseini, S Mohsen; Lehtimäki, Terho; Lu, Yi; Haller, Toomas; Xie, Jing; Delcourt, Cécile; Pirastu, Mario; Wedenoja, Juho; Gharahkhani, Puya; Venturini, Cristina; Miyake, Masahiro; Hewitt, Alex W; Guo, Xiaobo; Mazur, Johanna; Huffman, Jenifer E; Williams, Katie M; Polasek, Ozren; Campbell, Harry; Rudan, Igor; Vatavuk, Zoran; Wilson, James F; Joshi, Peter K; McMahon, George; St Pourcain, Beate; Evans, David M; Simpson, Claire L; Schwantes-An, Tae-Hwi; Igo, Robert P; Mirshahi, Alireza; Cougnard-Gregoire, Audrey; Bellenguez, Céline; Blettner, Maria; Raitakari, Olli; Kähönen, Mika; Seppala, Ilkka; Zeller, Tanja; Meitinger, Thomas; Ried, Janina S; Gieger, Christian; Portas, Laura; van Leeuwen, Elisabeth M; Amin, Najaf; Uitterlinden, André G; Rivadeneira, Fernando; Hofman, Albert; Vingerling, Johannes R; Wang, Ya Xing; Wang, Xu; Tai-Hui Boh, Eileen; Ikram, M Kamran; Sabanayagam, Charumathi; Gupta, Preeti; Tan, Vincent; Zhou, Lei; Ho, Candice E H; Lim, Wan'e; Beuerman, Roger W; Siantar, Rosalynn; Tai, E-Shyong; Vithana, Eranga; Mihailov, Evelin; Khor, Chiea-Chuen; Hayward, Caroline; Luben, Robert N; Foster, Paul J; Klein, Barbara E K; Klein, Ronald; Wong, Hoi-Suen; Mitchell, Paul; Metspalu, Andres; Aung, Tin; Young, Terri L; He, Mingguang; Pärssinen, Olavi; van Duijn, Cornelia M; Jin Wang, Jie; Williams, Cathy; Jonas, Jost B; Teo, Yik-Ying; Mackey, David A; Oexle, Konrad; Yoshimura, Nagahisa; Paterson, Andrew D; Pfeiffer, Norbert; Wong, Tien-Yin; Baird, Paul N; Stambolian, Dwight; Wilson, Joan E Bailey; Cheng, Ching-Yu; Hammond, Christopher J; Klaver, Caroline C W; Saw, Seang-Mei; Rahi, Jugnoo S; Korobelnik, Jean-François; Kemp, John P; Timpson, Nicholas J; Smith, George Davey; Craig, Jamie E; Burdon, Kathryn P; Fogarty, Rhys D; Iyengar, Sudha K; Chew, Emily; Janmahasatian, Sarayut; Martin, Nicholas G; MacGregor, Stuart; Xu, Liang; Schache, Maria; Nangia, Vinay; Panda-Jonas, Songhomitra; Wright, Alan F; Fondran, Jeremy R; Lass, Jonathan H; Feng, Sheng; Zhao, Jing Hua; Khaw, Kay-Tee; Wareham, Nick J; Rantanen, Taina; Kaprio, Jaakko; Pang, Chi Pui; Chen, Li Jia; Tam, Pancy O; Jhanji, Vishal; Young, Alvin L; Döring, Angela; Raffel, Leslie J; Cotch, Mary-Frances; Li, Xiaohui; Yip, Shea Ping; Yap, Maurice K H; Biino, Ginevra; Vaccargiu, Simona; Fossarello, Maurizio; Fleck, Brian; Yazar, Seyhan; Tideman, Jan Willem L; Tedja, Milly; Deangelis, Margaret M; Morrison, Margaux; Farrer, Lindsay; Zhou, Xiangtian; Chen, Wei; Mizuki, Nobuhisa; Meguro, Akira; Mäkelä, Kari Matti

    2016-03-29

    Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10(-5)), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia.

  1. Meta-analysis of gene–environment-wide association scans accounting for education level identifies additional loci for refractive error

    Science.gov (United States)

    Fan, Qiao; Verhoeven, Virginie J. M.; Wojciechowski, Robert; Barathi, Veluchamy A.; Hysi, Pirro G.; Guggenheim, Jeremy A.; Höhn, René; Vitart, Veronique; Khawaja, Anthony P.; Yamashiro, Kenji; Hosseini, S Mohsen; Lehtimäki, Terho; Lu, Yi; Haller, Toomas; Xie, Jing; Delcourt, Cécile; Pirastu, Mario; Wedenoja, Juho; Gharahkhani, Puya; Venturini, Cristina; Miyake, Masahiro; Hewitt, Alex W.; Guo, Xiaobo; Mazur, Johanna; Huffman, Jenifer E.; Williams, Katie M.; Polasek, Ozren; Campbell, Harry; Rudan, Igor; Vatavuk, Zoran; Wilson, James F.; Joshi, Peter K.; McMahon, George; St Pourcain, Beate; Evans, David M.; Simpson, Claire L.; Schwantes-An, Tae-Hwi; Igo, Robert P.; Mirshahi, Alireza; Cougnard-Gregoire, Audrey; Bellenguez, Céline; Blettner, Maria; Raitakari, Olli; Kähönen, Mika; Seppala, Ilkka; Zeller, Tanja; Meitinger, Thomas; Ried, Janina S.; Gieger, Christian; Portas, Laura; van Leeuwen, Elisabeth M.; Amin, Najaf; Uitterlinden, André G.; Rivadeneira, Fernando; Hofman, Albert; Vingerling, Johannes R.; Wang, Ya Xing; Wang, Xu; Tai-Hui Boh, Eileen; Ikram, M. Kamran; Sabanayagam, Charumathi; Gupta, Preeti; Tan, Vincent; Zhou, Lei; Ho, Candice E. H.; Lim, Wan'e; Beuerman, Roger W.; Siantar, Rosalynn; Tai, E-Shyong; Vithana, Eranga; Mihailov, Evelin; Khor, Chiea-Chuen; Hayward, Caroline; Luben, Robert N.; Foster, Paul J.; Klein, Barbara E. K.; Klein, Ronald; Wong, Hoi-Suen; Mitchell, Paul; Metspalu, Andres; Aung, Tin; Young, Terri L.; He, Mingguang; Pärssinen, Olavi; van Duijn, Cornelia M.; Jin Wang, Jie; Williams, Cathy; Jonas, Jost B.; Teo, Yik-Ying; Mackey, David A.; Oexle, Konrad; Yoshimura, Nagahisa; Paterson, Andrew D.; Pfeiffer, Norbert; Wong, Tien-Yin; Baird, Paul N.; Stambolian, Dwight; Wilson, Joan E. Bailey; Cheng, Ching-Yu; Hammond, Christopher J.; Klaver, Caroline C. W.; Saw, Seang-Mei; Rahi, Jugnoo S.; Korobelnik, Jean-François; Kemp, John P.; Timpson, Nicholas J.; Smith, George Davey; Craig, Jamie E.; Burdon, Kathryn P.; Fogarty, Rhys D.; Iyengar, Sudha K.; Chew, Emily; Janmahasatian, Sarayut; Martin, Nicholas G.; MacGregor, Stuart; Xu, Liang; Schache, Maria; Nangia, Vinay; Panda-Jonas, Songhomitra; Wright, Alan F.; Fondran, Jeremy R.; Lass, Jonathan H.; Feng, Sheng; Zhao, Jing Hua; Khaw, Kay-Tee; Wareham, Nick J.; Rantanen, Taina; Kaprio, Jaakko; Pang, Chi Pui; Chen, Li Jia; Tam, Pancy O.; Jhanji, Vishal; Young, Alvin L.; Döring, Angela; Raffel, Leslie J.; Cotch, Mary-Frances; Li, Xiaohui; Yip, Shea Ping; Yap, Maurice K.H.; Biino, Ginevra; Vaccargiu, Simona; Fossarello, Maurizio; Fleck, Brian; Yazar, Seyhan; Tideman, Jan Willem L.; Tedja, Milly; Deangelis, Margaret M.; Morrison, Margaux; Farrer, Lindsay; Zhou, Xiangtian; Chen, Wei; Mizuki, Nobuhisa; Meguro, Akira; Mäkelä, Kari Matti

    2016-01-01

    Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10−5), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia. PMID:27020472

  2. Negative Cognitive Errors and Positive Illusions: Moderators of Relations between Divorce Events and Children's Psychological Adjustment.

    Science.gov (United States)

    Mazur, Elizabeth; Wolchik, Sharlene

    Building on prior literature on adults' and children's appraisals of stressors, this study investigated relations among negative and positive appraisal biases, negative divorce events, and children's post-divorce adjustment. Subjects were 79 custodial nonremarried mothers and their children ages 9 to 13 who had experienced parental divorce within…

  3. Hand position-dependent modulation of errors in vibrotactile temporal order judgments

    DEFF Research Database (Denmark)

    Ritterband-Rosenbaum, Anina; Hermosillo, Robert; Kroliczak, Gregory;

    2014-01-01

    The ability to decide which of the two stimuli is presented first can be probed using a temporal order judgment (TOJ) task. When the stimuli are delivered to the fingers, TOJ decisions can be confounded by the fact that the hands can be moved to different locations in space. How and where this co...... and proprioceptive information related to arm position in space....

  4. Allelic association studies of genome wide association data can reveal errors in marker position assignments

    Directory of Open Access Journals (Sweden)

    Curtis David

    2007-06-01

    Full Text Available Abstract Background Genome wide association (GWA studies provide the opportunity to develop new kinds of analysis. Analysing pairs of markers from separate regions might lead to the detection of allelic association which might indicate an interaction between nearby genes. Methods 396,591 markers typed in 541 subjects were studied. 7.8*1010 pairs of markers were screened and those showing initial evidence for allelic association were subjected to more thorough investigation along with 10 flanking markers on either side. Results No evidence was detected for interaction. However 6 markers appeared to have an incorrect map position according to NCBI Build 35. One of these was corrected in Build 36 and 2 were dropped. The remaining 3 were left with map positions inconsistent with their allelic association relationships. Discussion Although no interaction effects were detected the method was successful in identifying markers with probably incorrect map positions. Conclusion The study of allelic association can supplement other methods for assigning markers to particular map positions. Analyses of this type may usefully be applied to data from future GWA studies.

  5. Compensation for geometric modeling errors by positioning of electrodes in electrical impedance tomography

    DEFF Research Database (Denmark)

    Hyvönen, N.; Majander, H.; Staboulis, Stratos

    2017-01-01

    that render reconstructing the internal conductivity impossible if they are not taken into account. This work numerically demonstrates that one can compensate for inaccurate modeling of the object boundary in two spatial dimensions by finding compatible locations and sizes for the electrodes as a part...... of a reconstruction algorithm. The numerical studies, which are based on both simulated and experimental data, are complemented by proving that the employed complete electrode model is approximately conformally invariant, which suggests that the obtained reconstructions in mismodeled domains reflect conformal images......Electrical impedance tomography aims at reconstructing the conductivity inside a physical body from boundary measurements of current and voltage at a finite number of contact electrodes. In many practical applications, the shape of the imaged object is subject to considerable uncertainties...

  6. Compensation for geometric modeling errors by positioning of electrodes in electrical impedance tomography

    Science.gov (United States)

    Hyvönen, N.; Majander, H.; Staboulis, S.

    2017-03-01

    Electrical impedance tomography aims at reconstructing the conductivity inside a physical body from boundary measurements of current and voltage at a finite number of contact electrodes. In many practical applications, the shape of the imaged object is subject to considerable uncertainties that render reconstructing the internal conductivity impossible if they are not taken into account. This work numerically demonstrates that one can compensate for inaccurate modeling of the object boundary in two spatial dimensions by finding compatible locations and sizes for the electrodes as a part of a reconstruction algorithm. The numerical studies, which are based on both simulated and experimental data, are complemented by proving that the employed complete electrode model is approximately conformally invariant, which suggests that the obtained reconstructions in mismodeled domains reflect conformal images of the true targets. The numerical experiments also confirm that a similar approach does not, in general, lead to a functional algorithm in three dimensions.

  7. Reducing the dosimetric impact of positional errors in field junctions for craniospinal irradiation using VMAT

    CERN Document Server

    Strojnik, Andrej; Peterlin, Primoz

    2016-01-01

    Aim: To improve treatment plan robustness with respect to small shifts in patient position during the VMAT treatment by ensuring a linear ramp-like dose profile in treatment field overlap regions. Background: Craniospinal irradiation (CSI) is considered technically challenging because the target size exceeds the maximal field size, which necessitates using abutted or overlapping treatment fields. Volumetric modulated arc therapy (VMAT) is increasingly being examined for CSI, as it offers both better dose homogeneity and better dose conformance while also offering a possibility to create field junctions which are more robust towards small shifts in patient position during the treatment. Materials and Methods: A VMAT treatment plan with three isocenters was made for a test case patient. Three groups of overlapping arc field pairs were used; one for the cranial and two for the spinal part. In order to assure a ramp-like dose profile in the field overlap region, the upper spinal part was optimised first, with dos...

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

    Science.gov (United States)

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

    2017-01-01

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

  9. Compliments and accounts : Positive evaluation of reported behavior in psychotherapy for adolescents

    NARCIS (Netherlands)

    Jager, Margot; De Winter, Andrea F.; Metselaar, Janneke; Knorth, Erik J.; Reijneveld, Sijmen A.; Huiskes, Mike

    2015-01-01

    Based on conversation analysis (CA) of video-recorded therapy sessions, the article explicates a particular interactional project of positively evaluating client-reported behavior in psychotherapy. The analysis focuses on the therapist's actions that convey a positive evaluation of client-reported b

  10. [GASTROSTOMY POSITIVELY AFFECTS NUTRITIONAL STATUS AND DIMINISHES HOSPITAL DAYS IN PATIENTS WITH INBORN ERRORS OF METABOLISM].

    Science.gov (United States)

    Guillén-López, Sara; Vela-Amieva, Marcela; Juárez-Cruz, Merit Valeria; González-Zamora, José Francisco; Monroy-Santoyo, Susana; Belmont-Martínez, Leticia

    2015-07-01

    Introducción: el tratamiento nutricional de los pacientes con errores innatos del metabolismo (EIM) implica el uso permanente de fórmulas modificadas en aminoácidos cuyas características organolépticas pueden dificultar su aceptación por vía oral. Estos pacientes pueden tener alteraciones gastrointestinales y requieren el uso constante de medicamentos, lo cual complica la adherencia al tratamiento, comprometiéndose con ello su estado nutricional y el control de la enfermedad. La gastrostomía es una alternativa para facilitar la alimentación y el tratamiento, pero existen controversias sobre su uso. Objetivo: comparar el estado nutricional y la duración de las hospitalizaciones antes y después de la realización de la gastrostomía en un grupo de pacientes con EIM. Métodos: análisis retrospectivo de datos antropométricos, número de internamientos por descompensación metabólica y su duración en pacientes pediátricos con EIM antes y después de la gastrostomía. Resultados: se analizaron 16 niños; 40% con defectos del propionato, 25% con alteraciones del ciclo de la urea y 35% con otros EIM. Después de la gastrostomía, la proporción de pacientes eutróficos aumentó del 6 al 56% y la desnutrición disminuyó del 94 al 44%. Después de la gastrostomía, la duración de los periodos hospitalarios disminuyó significativamente de 425 a 131 días (p = 0.011); el número de internamientos disminuyó de 33 antes de la intervención a 17, sin embargo, esta diferencia no tuvo significación estadística. Conclusión: en esta muestra, la gastrostomía mejoró el estado nutricional en 56% de los pacientes con EIM, y redujo significativamente los días de hospitalización por descompensación metabólica.

  11. Position-independent geometric error identification and global sensitivity analysis for the rotary axes of five-axis machine tools

    Science.gov (United States)

    Guo, Shijie; Jiang, Gedong; Zhang, Dongsheng; Mei, Xuesong

    2017-04-01

    Position-independent geometric errors (PIGEs) are the fundamental errors of a five-axis machine tool. In this paper, to identify ten PIGEs peculiar to the rotary axes of five-axis machine tools with a tilting head, the mathematic model of the ten PIGEs is deduced and four measuring patterns are proposed. The measuring patterns and identifying method are validated on a five-axis machine tool with a tilting head, and the ten PIGEs of the machine tool are obtained. The sensitivities of the four adjustable PIGEs of the machine tool in different measuring patterns are analyzed by the Morris global sensitivity analysis method and the modifying method, and the procedure of the four adjustable PIGEs of the machine tool is given accordingly. Experimental results show that after and before modifying the four adjustable PIGEs, the average compensate rate reached 52.7%. It is proved that the proposed measuring, identifying, analyzing and modifying method are effective for error measurement and precision improvement of the five-axis machine tool.

  12. Can the Pro-Drop Parameter Account for All the Errors in the Acquisition of Non-Referential It in L2 English?

    Directory of Open Access Journals (Sweden)

    Elena Antonova-Ünlü

    2015-06-01

    Full Text Available Abstract Numerous studies, examining the acquisition of non-referential it in [-pro-drop] English by learners of [+pro-drop] languages, have revealed that their participants omit non-referential subjects in English if their L1 allows null-subject position. However, due to the specificity of their focus, these studies have not considered other difficulties native speakers of [+pro-drop] languages might encounter when learning non-referential subjects in English settings and have given an impression that omission is the only error L2 learners make while acquiring non-referential subjects. The present study offers a detailed account of the acquisition of non-referential it by native speakers of [+pro-drop] Russian in a classroom setting, investigates which domains of use of non-referential it may cause difficulties for L1 speakers of [+pro-drop] Russian, and examines how error patterns related to the use of non-referential it change with further exposure to the English language. To this end, the data are collected from two groups of Russian students, fourth- and seventh-year learners of English, who are at the pre-intermediate and upper-intermediate levels of English. The participants were asked to undertake comprehension and production tests. Quantitative and qualitative analyses are used in the study. The findings show that all the participants have difficulties related to the use of non-referential it, and error patterns made by the speakers of [+pro-drop] Russian are not limited to omissions of non-referential it. Moreover, error patterns observed in the students’ data differ significantly among the groups. While the pre-intermediate fourth-year English learners mostly rely on their L1 and make literal translations from Russian, the upper-intermediate seventh-year learners, by and large, have problems in distinguishing between non-referential it and there and, due to this, make numerous errors in some domains. Résumé De nombreuses analyses

  13. Creation of graphic database specifying android arm mechanism work envelope taking into account forbidden zones position

    Science.gov (United States)

    Pritykin, F. N.; Nebritov, V. I.

    2017-06-01

    The structure of graphic database specifying the shape and the work envelope projection position of an android arm mechanism with various positions of the known in advance forbidden zones is proposed. The technique of analytical assignment of the work envelope based on the methods of analytical geometry and theory of sets is represented. The conducted studies can be applied in creation of knowledge bases for intellectual systems of android control functioning independently in the sophisticated environment.

  14. An information theory account of late frontoparietal ERP positivities in cognitive control.

    Science.gov (United States)

    Barceló, Francisco; Cooper, Patrick S

    2017-03-15

    ERP research on task switching has revealed distinct transient and sustained positive waveforms (latency circa 300-900 ms) while shifting task rules or stimulus-response (S-R) mappings. However, it remains unclear whether such switch-related positivities show similar scalp topography and index context-updating mechanisms akin to those posed for domain-general (i.e., classic P300) positivities in many task domains. To examine this question, ERPs were recorded from 31 young adults (18-30 years) while they were intermittently cued to switch or repeat their perceptual categorization of Gabor gratings varying in color and thickness (switch task), or else they performed two visually identical control tasks (go/no-go and oddball). Our task cueing paradigm examined two temporarily distinct stages of proactive rule updating and reactive rule execution. A simple information theory model helped us gauge cognitive demands under distinct temporal and task contexts in terms of low-level S-R pathways and higher-order rule updating operations. Task demands modulated domain-general (indexed by classic oddball P3) and switch positivities-indexed by both a cue-locked late positive complex and a sustained positivity ensuing task transitions. Topographic scalp analyses confirmed subtle yet significant split-second changes in the configuration of neural sources for both domain-general P3s and switch positivities as a function of both the temporal and task context. These findings partly meet predictions from information estimates, and are compatible with a family of P3-like potentials indexing functionally distinct neural operations within a common frontoparietal "multiple demand" system during the preparation and execution of simple task rules. © 2016 Society for Psychophysiological Research.

  15. Error analysis of linear optics measurements via turn-by-turn beam position data in circular accelerators

    CERN Document Server

    Franchi, Andrea

    2016-01-01

    Many advanced techniques have been developed, tested and implemented in the last decades in almost all circular accelerators across the world to measure the linear optics. However, the greater availability and accuracy of beam diagnostics and the ever better correction of linear magnetic lattice imperfections (beta beating at 1% level and coupling at 0.1%) are reaching what seems to be the intrinsic accuracy and precision of different measurement techniques. This paper aims to highlight and quantify, when possible, the limitations of one standard method, the harmonic analysis of turn-by-turn beam position data. To this end, new analytic formulas for the evaluation of lattice parameters modified by focusing errors are derived. The unexpected conclusion of this study is that for the ESRF storage ring (and possibly for any third generation light source operating at ultra-low coupling and with similar diagnostics), measurement and correction of linear optics via orbit beam position data are to be preferred to the...

  16. Analysis of direct clinical consequences of MLC positional errors in volumetric-modulated arc therapy using 3D dosimetry system.

    Science.gov (United States)

    Nithiyanantham, Karthikeyan; Mani, Ganesh K; Subramani, Vikraman; Mueller, Lutz; Palaniappan, Karrthick K; Kataria, Tejinder

    2015-09-08

    In advanced, intensity-modulated external radiotherapy facility, the multileaf collimator has a decisive role in the beam modulation by creating multiple segments or dynamically varying field shapes to deliver a uniform dose distribution to the target with maximum sparing of normal tissues. The position of each MLC leaf has become more critical for intensity-modulated delivery (step-and-shoot IMRT, dynamic IMRT, and VMAT) compared to 3D CRT, where it defines only field boundaries. We analyzed the impact of the MLC positional errors on the dose distribution for volumetric-modulated arc therapy, using a 3D dosimetry system. A total of 15 VMAT cases, five each for brain, head and neck, and prostate cases, were retrospectively selected for the study. All the plans were generated in Monaco 3.0.0v TPS (Elekta Corporation, Atlanta, GA) and delivered using Elekta Synergy linear accelerator. Systematic errors of +1, +0.5, +0.3, 0, -1, -0.5, -0.3 mm were introduced in the MLC bank of the linear accelerator and the impact on the dose distribution of VMAT delivery was measured using the COMPASS 3D dosim-etry system. All the plans were created using single modulated arcs and the dose calculation was performed using a Monte Carlo algorithm in a grid size of 3 mm. The clinical endpoints D95%, D50%, D2%, and Dmax,D20%, D50% were taken for the evaluation of the target and critical organs doses, respectively. A significant dosimetric effect was found for many cases even with 0.5 mm of MLC positional errors. The average change of dose D 95% to PTV for ± 1 mm, ± 0.5 mm, and ±0.3mm was 5.15%, 2.58%, and 0.96% for brain cases; 7.19%, 3.67%, and 1.56% for head and neck cases; and 8.39%, 4.5%, and 1.86% for prostate cases, respectively. The average deviation of dose Dmax was 5.4%, 2.8%, and 0.83% for brainstem in brain cases; 8.2%, 4.4%, and 1.9% for spinal cord in H&N; and 10.8%, 6.2%, and 2.1% for rectum in prostate cases, respectively. The average changes in dose followed a linear

  17. Branch-Based Model for the Diameters of the Pulmonary Airways: Accounting for Departures From Self-Consistency and Registration Errors

    Energy Technology Data Exchange (ETDEWEB)

    Neradilek, Moni B.; Polissar, Nayak L.; Einstein, Daniel R.; Glenny, Robb W.; Minard, Kevin R.; Carson, James P.; Jiao, Xiangmin; Jacob, Richard E.; Cox, Timothy C.; Postlethwait, Edward M.; Corley, Richard A.

    2012-04-24

    We examine a previously published branch-based approach to modeling airway diameters that is predicated on the assumption of self-consistency across all levels of the tree. We mathematically formulate this assumption, propose a method to test it and develop a more general model to be used when the assumption is violated. We discuss the effect of measurement error on the estimated models and propose methods that account for it. The methods are illustrated on data from MRI and CT images of silicone casts of two rats, two normal monkeys and one ozone-exposed monkey. Our results showed substantial departures from self-consistency in all five subjects. When departures from selfconsistency exist we do not recommend using the self-consistency model, even as an approximation, as we have shown that it may likely lead to an incorrect representation of the diameter geometry. Measurement error has an important impact on the estimated morphometry models and needs to be accounted for in the analysis.

  18. Branch-based model for the diameters of the pulmonary airways: accounting for departures from self-consistency and registration errors.

    Science.gov (United States)

    Neradilek, Moni B; Polissar, Nayak L; Einstein, Daniel R; Glenny, Robb W; Minard, Kevin R; Carson, James P; Jiao, Xiangmin; Jacob, Richard E; Cox, Timothy C; Postlethwait, Edward M; Corley, Richard A

    2012-06-01

    We examine a previously published branch-based approach for modeling airway diameters that is predicated on the assumption of self-consistency across all levels of the tree. We mathematically formulate this assumption, propose a method to test it and develop a more general model to be used when the assumption is violated. We discuss the effect of measurement error on the estimated models and propose methods that take account of error. The methods are illustrated on data from MRI and CT images of silicone casts of two rats, two normal monkeys, and one ozone-exposed monkey. Our results showed substantial departures from self-consistency in all five subjects. When departures from self-consistency exist, we do not recommend using the self-consistency model, even as an approximation, as we have shown that it may likely lead to an incorrect representation of the diameter geometry. The new variance model can be used instead. Measurement error has an important impact on the estimated morphometry models and needs to be addressed in the analysis.

  19. Modelling positional uncertainty of line features by accounting for stochastic deviations from straight line segments

    NARCIS (Netherlands)

    Bruin, de S.

    2008-01-01

    The assessment of positional uncertainty in line and area features is often based on uncertainty in the coordinates of their elementary vertices which are assumed to be connected by straight lines. Such an approach disregards uncertainty caused by sampling and approximation of a curvilinear feature

  20. THE POSITIVE EFFECTS OF THE LABOUR MOBILITY ON CURRENT ACCOUNT OF ROMANIA

    Directory of Open Access Journals (Sweden)

    Irina Elena CHIRTOC

    2010-12-01

    Full Text Available The phenomenon of international mobility of labour resources is important to the economy of any country in the course of development. In addition to the adverse effects that might cause this phenomenon are not neglected a favourable effect on the area of origin. Thus, the migrants are receiving higher income abroad is an impetus for those remaining in the country to raise the level of training to become more competitive. In addition, migrants are sending money in area of origin to family or friends, which contribute to increasing the standard of living for them and the reduction of poverty. Even though most of these transfers is spent on consumption goods and services by the family remaining in the country, should not be out of sight of the multiplicative effect in stimulating supply consumption, nor the effects of such transfers in reducing the deficit of current account.

  1. Adaptive planning strategy for high dose rate prostate brachytherapy—a simulation study on needle positioning errors.

    Science.gov (United States)

    Borot de Battisti, M; Denis de Senneville, B; Maenhout, M; Hautvast, G; Binnekamp, D; Lagendijk, J J W; van Vulpen, M; Moerland, M A

    2016-03-01

    The development of magnetic resonance (MR) guided high dose rate (HDR) brachytherapy for prostate cancer has gained increasing interest for delivering a high tumor dose safely in a single fraction. To support needle placement in the limited workspace inside the closed-bore MRI, a single-needle MR-compatible robot is currently under development at the University Medical Center Utrecht (UMCU). This robotic device taps the needle in a divergent way from a single rotation point into the prostate. With this setup, it is warranted to deliver the irradiation dose by successive insertions of the needle. Although robot-assisted needle placement is expected to be more accurate than manual template-guided insertion, needle positioning errors may occur and are likely to modify the pre-planned dose distribution.In this paper, we propose a dose plan adaptation strategy for HDR prostate brachytherapy with feedback on the needle position: a dose plan is made at the beginning of the interventional procedure and updated after each needle insertion in order to compensate for possible needle positioning errors. The introduced procedure can be used with the single needle MR-compatible robot developed at the UMCU. The proposed feedback strategy was tested by simulating complete HDR procedures with and without feedback on eight patients with different numbers of needle insertions (varying from 4 to 12). In of the cases tested, the number of clinically acceptable plans obtained at the end of the procedure was larger with feedback compared to the situation without feedback. Furthermore, the computation time of the feedback between each insertion was below 100 s which makes it eligible for intra-operative use.

  2. Implications for GAAP from an analysis of positive research in accounting

    OpenAIRE

    Ramanna, Karthik; Douglas J. Skinner; Kothari, S. P.

    2010-01-01

    Based on extant literature, we review the positive theory of GAAP. The theory predicts that GAAP’s principal focus is on control (performance measurement and stewardship) and that verifiability and conservatism are critical features of a GAAP shaped by market forces. We recognize the advantage of using fair values in circumstances where these are based on observable prices in liquid secondary markets, but caution against expanding fair values to financial reporting more generally. We conclude...

  3. The effect of pirenzepine on positive- and negative-lens-induced refractive error and ocular growth in chicks.

    Science.gov (United States)

    Metlapally, Sangeetha; McBrien, Neville A

    2010-11-01

    The selective muscarinic antagonist pirenzepine inhibits experimentally induced myopia in avian and mammalian species, including nonhuman primates and adolescent humans. Transient positive lens defocus has a potent inhibitory effect on negative-lens-induced myopia in avian and mammalian models. The purpose of the present study was to determine the influence of daily treatment with pirenzepine on ocular growth and refractive error in chicks wearing positive lenses. The chicks were allocated to one of eight groups (n = 6 each group) on the basis of whether they wore +10 or -10 D lenses monocularly and whether they received daily intravitreal injections of pirenzepine (700 μg) or vehicle (phosphate-buffered saline) in the lens-defocused eye. In vivo refractive and biometric data were collected, and glycosaminoglycan synthesis in the sclera was assessed. Pirenzepine did not alter the level of positive-lens-induced hyperopia in chicks wearing +10 D lenses compared with that in the vehicle control group (+8.1 ± 0.6 D vs. +8.9 ± 2.4 D, mean ± SEM; P = 0.76). In contrast, pirenzepine caused significant inhibition of negative-lens-induced myopia compared with that in the vehicle group (-1.1 ± 1.5 D vs. -8.8 ± 1.1 D; P = 0.001). Glycosaminoglycan synthesis in the posterior sclera was significantly increased in the negative-lens-treated groups and showed small decreases in the positive-lens-treated groups. The influence of pirenzepine on ocular growth in chicks differed by sign of lens defocus, with pirenzepine blocking negative-lens effects on ocular growth, but not positive-lens effects. The most likely reason that hyperopia was not enhanced by pirenzepine treatment was that the rapid compensatory eye growth associated with positive lenses eliminated the imposed myopic defocus, and the clear retinal image prevented any additional hyperopia from developing.

  4. Increased Public Accountability for Hospital Nonprofit Status: Potential Impacts on Residency Positions.

    Science.gov (United States)

    Raffoul, Melanie C; Phillips, Robert L

    2017-01-01

    The Institute of Medicine recently called for greater graduate medical education (GME) accountability for meeting the workforce needs of the nation. The Affordable Care Act expanded community health needs assessment (CHNA) requirements for nonprofit and tax-exempt hospitals to include community assessment, intervention, and evaluation every 3 years but did not specify details about workforce. Texas receives relatively little federal GME funding but has used Medicaid waivers to support GME expansion. The objective of this article was to examine Texas CHNAs and regional health partnership (RHP) plans to determine to what extent they identify community workforce need or include targeted GME changes or expansion since the enactment of the Affordable Care Act and the revised Internal Revenue Service requirements for CHNAs. Texas hospitals (n = 61) received federal GME dollars during the study period. Most of these hospitals completed a CHNA; nearly all hospitals receiving federal GME dollars but not mandated to complete a CHNA participated in similar state-based RHP plans. The 20 RHPs included assessments and intervention proposals under a 1115 Medicaid waiver. Every CHNA and RHP was reviewed for any mention of GME-related needs or interventions. The latest available CHNAs and RHPs were reviewed in 2015. All CHNA and RHP plans were dated 2011 to 2015. Of the 38 hospital CHNAs, 26 identified a workforce need in primary care, 34 in mental health, and 17 in subspecialty care. A total of 36 CHNAs included implementation plans, of which 3 planned to address the primary care workforce need through an increase in GME funding, 1 planned to do so for psychiatry training, and 1 for subspecialty training. Of the 20 RHPs, 18 identified workforce needs in primary care, 20 in mental health, and 15 in subspecialty training. Five RHPs proposed to increase GME funding for primary care, 3 for psychiatry, and 1 for subspecialty care. Hospital CHNAs and other regional health assessments

  5. Motion and positional error correction for cone beam 3D-reconstruction with mobile C-arms.

    Science.gov (United States)

    Bodensteiner, C; Darolti, C; Schumacher, H; Matthäus, L; Schweikard, A

    2007-01-01

    CT-images acquired by mobile C-arm devices can contain artefacts caused by positioning errors. We propose a data driven method based on iterative 3D-reconstruction and 2D/3D-registration to correct projection data inconsistencies. With a 2D/3D-registration algorithm, transformations are computed to align the acquired projection images to a previously reconstructed volume. In an iterative procedure, the reconstruction algorithm uses the results of the registration step. This algorithm also reduces small motion artefacts within 3D-reconstructions. Experiments with simulated projections from real patient data show the feasibility of the proposed method. In addition, experiments with real projection data acquired with an experimental robotised C-arm device have been performed with promising results.

  6. The definition of the railway position control error in the plane and profile using the optical-electronic system

    Science.gov (United States)

    Nikulin, Anton V.; Timofeev, Alexandr N.; Nekrylov, Ivan S.

    2015-05-01

    Continuous development of high-speed railway traffic in the world toughens requirements, including to the accuracy of installation and control of provision of a railway track. For the current technologies of service of a railway track using its absolute coordinates the perspective decision is creation along railway lines of a special fiducial network. In this case by means of optical-electronic systems, concerning reference points, obtaining the objective information on actual position of a railway track in a longitudinal cross-section and the plan with a margin error which isn't exceeding 1,5 mm in rather severe conditions of continuous operation of traveling machines at speeds up to 10 km/h is possible.

  7. Modelling of the X,Y,Z positioning errors and uncertainty evaluation for the LNE’s mAFM using the Monte Carlo method

    Science.gov (United States)

    Ceria, Paul; Ducourtieux, Sebastien; Boukellal, Younes; Allard, Alexandre; Fischer, Nicolas; Feltin, Nicolas

    2017-03-01

    In order to evaluate the uncertainty budget of the LNE’s mAFM, a reference instrument dedicated to the calibration of nanoscale dimensional standards, a numerical model has been developed to evaluate the measurement uncertainty of the metrology loop involved in the XYZ positioning of the tip relative to the sample. The objective of this model is to overcome difficulties experienced when trying to evaluate some uncertainty components which cannot be experimentally determined and more specifically, the one linked to the geometry of the metrology loop. The model is based on object-oriented programming and developed under Matlab. It integrates one hundred parameters that allow the control of the geometry of the metrology loop without using analytical formulae. The created objects, mainly the reference and the mobile prism and their mirrors, the interferometers and their laser beams, can be moved and deformed freely to take into account several error sources. The Monte Carlo method is then used to determine the positioning uncertainty of the instrument by randomly drawing the parameters according to their associated tolerances and their probability density functions (PDFs). The whole process follows Supplement 2 to ‘The Guide to the Expression of the Uncertainty in Measurement’ (GUM). Some advanced statistical tools like Morris design and Sobol indices are also used to provide a sensitivity analysis by identifying the most influential parameters and quantifying their contribution to the XYZ positioning uncertainty. The approach validated in the paper shows that the actual positioning uncertainty is about 6 nm. As the final objective is to reach 1 nm, we engage in a discussion to estimate the most effective way to reduce the uncertainty.

  8. 惯导轨迹发生器误差引入研究%Simulation of Full Account Error in Strap-down Inertial Navigation Trajectory Generator

    Institute of Scientific and Technical Information of China (English)

    杨彬; 金毅; 高娜; 吴训忠

    2015-01-01

    As the traditional strap-down inertial navigation trajectory generators have some problems such as only considering white noise or not in all round way when importing error, a new trajectory generator which takes a full account of error is put forward. Using trajectory generator to create ideal output, importing the error which is modeled from real devices, the final outputs which are much close to the reality has been got. the traditional trajectory generators and the new one are compared for analyzing.The result demonstrates that the new trajectory generator is more reliable and practical than the traditional one.%轨迹发生器为捷联惯导算法程序提供仿真测试数据。选定理想轨迹,用捷联惯导原理逆向解算出元件输出,引入误差后输入捷联惯导算法程序,得到解算轨迹。针对传统捷联惯导轨迹发生器引入误差不全面的问题,提出全面考虑误差的新型轨迹发生器。用元件真实数据分析出各项误差,将各项误差引入理想元件输出,得到较传统捷联惯导轨迹发生器更加接近真实情况的轨迹数据。仿真结果表明,新型轨迹发生器较传统轨迹发生器更加接近真实情况,是一种可靠的捷联惯导轨迹发生器。

  9. Sugar-sweetened beverage consumption and central and total adiposity in older children: a prospective study accounting for dietary reporting errors.

    Science.gov (United States)

    Bigornia, Sherman J; LaValley, Michael P; Noel, Sabrina E; Moore, Lynn L; Ness, Andy R; Newby, P K

    2015-05-01

    To determine the prospective relationship between changes in sugar-sweetened beverage (SSB) intake and central adiposity in older children. Dietary intakes of children were obtained by 3 d food records at ages 10 and 13 years. Waist circumference (WC) and weight and height to determine BMI were measured at 10 and 13 years and total body fat mass (TBFM) at 13 years by dual-energy X-ray absorptiometry. Analyses were conducted using multivariable linear regression. Reporting errors were measured and participants were categorized as under-, plausible and over-reporters of dietary intakes. Community-based British cohort of children participating in the Avon Longitudinal Study of Parents and Children. Among 2455 older children, increased SSB consumption from ages 10 to 13 years was associated with higher WC (standardized β=0.020, P=0.19), BMI (β=0.028, P=0.03) and TBFM (β=0.017, P=0.20) at 13 years. Effects were strengthened among plausible dietary reporters (n 1059): WC (β=0.097, Pconsumption of SSB from ages 10 to 13 years was associated with a larger WC at age 13 years independent of differences in total adiposity. Accounting for dietary reporting errors strengthened associations. Our findings further support recommendations to limit intakes of SSB to reduce excess weight gain in children and suggest that SSB have an additional deleterious effect on central adiposity.

  10. Errores en el Ajuste del Valor Posicional en Tareas de Estimación: un Estudio con Maestros en Formación (Error in the Adjustment of Positional Value in Computational Estimation Tasks: A Study with Elementary Preservice Teachers

    Directory of Open Access Journals (Sweden)

    Carlos de Castro

    2008-06-01

    Full Text Available En este estudio se analizan los errores, en el ajuste del valor posicional, en los que incurren maestros en formación en tareas de estimación de multiplicación y división con números naturales y decimales. Para ello, se elaboró una prueba de estimación compuesta por 24 cálculos directos, sin contexto, que se aplicó a 26 futuros maestros. Posteriormente se realizaron entrevistas para determinar los errores en los que incurrieron y se encontraron 8 tipos diferentes de errores. Los errores más frecuentes son los debidos a un conteo defectuoso de las posiciones para esta-blecer el orden de magnitud de los resultados y los que se producen al dividir un número por otro mayor añadiendo un cero de más al cociente. La colocación de la coma decimal en el resultado es, en todos los casos, una gran fuente de dificultad. In this study we analyze elementary preservice teachers’ errors, in the adjustment of positional value, in computational estimation tasks involving multiplication and division with integers and decimals. We designed an estimation test composed by 24 direct computations, without context, which we administered to 26 future teachers. Later we interviewed them to determine the errors made in estimation and found 8 different types of errors. The more frequent errors are the ones due to a wrong counting of positions to establish the order of magnitude of the results, and errors produced in division when the divisor is greater than the dividend by adding one extra cero to the quotient. Finding the place for the decimal point is, in all the cases, a great source of difficulty.

  11. The investigation of the difference between accounting data error in future operational cash flow predication , before and after adjust, due to inflation in accepted companies in Tehran stock exchange

    Directory of Open Access Journals (Sweden)

    Daryoush Javid

    2014-07-01

    Full Text Available The present research examines the difference between accounting data error in future operational cash flow predication before and after adjust due to inflation the population in this research include the accepted companies in Tehran stock exchange. The sample member companies financial statements by mean of current value – constant Rials were adjusted and were accounting data error in future and before adjust due to accounting inflation. After examination of the accounting data prediction before and after adjust, statistical data were tested by means of jariko method so that their normality by examined. The obtained results of jariko-Bera test indicate that the statistical data distribution is not normal. Therefore the sample couple signal Nonparametic test is used for investigation of difference between accounting data error in future cash floe prediction before and after adjust. the research hypothesis is : The accounting data error based on historical values is move than accounting data error based on current values in future period operational cash flow. The obtained results of sample even signal in relation to research hypothesis indication that we can accept the research hypothesis Normal 0 false false false EN-US X-NONE AR-SA

  12. MSH2 and MLH1 mutations in sporadic replication error-positive colorectal carcinoma as assessed by two-dimensional DNA electrophoresis

    NARCIS (Netherlands)

    Wu, Y; NystromLahti, M; Osinga, J; Looman, MWG; Peltomaki, P; Aaltonen, LA; delaChapelle, A; Hofstra, RMW; Buys, CHCM

    1997-01-01

    Replication errors (RER) are frequently seen in both sporadic and hereditary forms of colorectal cancer. In hereditary nonpolyposis colorectal cancer (HNPCC), RER is associated with defects in DNA mismatch repair genes. Two of these genes, MSH2 and MLH1, account for a major share of this cancer synd

  13. An update on modeling dose-response relationships: Accounting for correlated data structure and heterogeneous error variance in linear and nonlinear mixed models.

    Science.gov (United States)

    Gonçalves, M A D; Bello, N M; Dritz, S S; Tokach, M D; DeRouchey, J M; Woodworth, J C; Goodband, R D

    2016-05-01

    Advanced methods for dose-response assessments are used to estimate the minimum concentrations of a nutrient that maximizes a given outcome of interest, thereby determining nutritional requirements for optimal performance. Contrary to standard modeling assumptions, experimental data often present a design structure that includes correlations between observations (i.e., blocking, nesting, etc.) as well as heterogeneity of error variances; either can mislead inference if disregarded. Our objective is to demonstrate practical implementation of linear and nonlinear mixed models for dose-response relationships accounting for correlated data structure and heterogeneous error variances. To illustrate, we modeled data from a randomized complete block design study to evaluate the standardized ileal digestible (SID) Trp:Lys ratio dose-response on G:F of nursery pigs. A base linear mixed model was fitted to explore the functional form of G:F relative to Trp:Lys ratios and assess model assumptions. Next, we fitted 3 competing dose-response mixed models to G:F, namely a quadratic polynomial (QP) model, a broken-line linear (BLL) ascending model, and a broken-line quadratic (BLQ) ascending model, all of which included heteroskedastic specifications, as dictated by the base model. The GLIMMIX procedure of SAS (version 9.4) was used to fit the base and QP models and the NLMIXED procedure was used to fit the BLL and BLQ models. We further illustrated the use of a grid search of initial parameter values to facilitate convergence and parameter estimation in nonlinear mixed models. Fit between competing dose-response models was compared using a maximum likelihood-based Bayesian information criterion (BIC). The QP, BLL, and BLQ models fitted on G:F of nursery pigs yielded BIC values of 353.7, 343.4, and 345.2, respectively, thus indicating a better fit of the BLL model. The BLL breakpoint estimate of the SID Trp:Lys ratio was 16.5% (95% confidence interval [16.1, 17.0]). Problems with

  14. Population and patient-specific target margins for 4D adaptive radiotherapy to account for intra- and inter-fraction variation in lung tumour position

    Science.gov (United States)

    Hugo, Geoffrey D.; Yan, Di; Liang, Jian

    2007-01-01

    In this work, five 4D image-guidance strategies (two population, an offline adaptive and two online strategies) were evaluated that compensated for both inter- and intra-fraction variability such as changes to the baseline tumour position and respiratory pattern. None of the strategies required active motion compensation such as gating or tracking; all strategies simulated a free-breathing-based treatment technique. Online kilovoltage fluoroscopy was acquired for eight patients with lung tumours, and used to construct inter- and intra-fraction tumour position variability models. Planning was performed on a mid-ventilation image acquired from a respiration-correlated CT scan. The blurring effect of tumour position variability was included in the dose calculation by convolution. CTV to PTV margins were calculated for variability in the cranio-caudal direction. A population margin of 9.0 ± 0.7 mm was required to account for setup error and respiration in the study population without the use of image-guidance. The greatest mean margin reduction was introduced by the offline adaptive strategy. A daily online correction strategy produced a small reduction (1.6 mm) in the mean margin from the offline strategy. Adaptively correcting for an inter-fraction change in the respiratory pattern had little effect on margin size due to most patients having only small daily changes in the respiratory pattern. A daily online correction strategy would be useful for patients who exhibit large variations in the daily mean tumour position, while an offline adaptive strategy is more applicable to patients with less variation.

  15. 12 CFR 220.128 - Treatment of simultaneous long and short positions in the same margin account when put or call...

    Science.gov (United States)

    2010-01-01

    ... positions in the same margin account when put or call options or combinations thereof on such stock are also...) Interpretations § 220.128 Treatment of simultaneous long and short positions in the same margin account when put... the deposit of margin ordinarily required in connection with the guarantee by a creditor of a put...

  16. Overcoming function annotation errors in the Gram-positive pathogen Streptococcus suis by a proteomics-driven approach

    Directory of Open Access Journals (Sweden)

    Bárcena José A

    2008-12-01

    Full Text Available Abstract Background Annotation of protein-coding genes is a key step in sequencing projects. Protein functions are mainly assigned on the basis of the amino acid sequence alone by searching of homologous proteins. However, fully automated annotation processes often lead to wrong prediction of protein functions, and therefore time-intensive manual curation is often essential. Here we describe a fast and reliable way to correct function annotation in sequencing projects, focusing on surface proteomes. We use a proteomics approach, previously proven to be very powerful for identifying new vaccine candidates against Gram-positive pathogens. It consists of shaving the surface of intact cells with two proteases, the specific cleavage-site trypsin and the unspecific proteinase K, followed by LC/MS/MS analysis of the resulting peptides. The identified proteins are contrasted by computational analysis and their sequences are inspected to correct possible errors in function prediction. Results When applied to the zoonotic pathogen Streptococcus suis, of which two strains have been recently sequenced and annotated, we identified a set of surface proteins without cytoplasmic contamination: all the proteins identified had exporting or retention signals towards the outside and/or the cell surface, and viability of protease-treated cells was not affected. The combination of both experimental evidences and computational methods allowed us to determine that two of these proteins are putative extracellular new adhesins that had been previously attributed a wrong cytoplasmic function. One of them is a putative component of the pilus of this bacterium. Conclusion We illustrate the complementary nature of laboratory-based and computational methods to examine in concert the localization of a set of proteins in the cell, and demonstrate the utility of this proteomics-based strategy to experimentally correct function annotation errors in sequencing projects. This

  17. Combining a differential global positioning system and double electric compass to improve multi-path error correction for a high-precision agricultural robotic vehicle

    OpenAIRE

    Chung-Teh Cheng

    2011-01-01

    This work has addressed the improving of the multi-path error in positioning systems by coupling a differential global positioning system (DGPS) and double electric compass (DEC) in the navigation system of an orchard robotic vehicle. A novel corrective algorithm model was applied to predicting the positioning coordinates during vehicle movement. The model manipulates a combination of data from both the DEC and the DGPS when the DGPS receiver is in problematic conditions in which the horizont...

  18. Effects of past and recent blood pressure and cholesterol level on coronary heart disease and stroke mortality, accounting for measurement error.

    Science.gov (United States)

    Boshuizen, Hendriek C; Lanti, Mariapaola; Menotti, Alessandro; Moschandreas, Joanna; Tolonen, Hanna; Nissinen, Aulikki; Nedeljkovic, Srecko; Kafatos, Anthony; Kromhout, Daan

    2007-02-15

    The authors aimed to quantify the effects of current systolic blood pressure (SBP) and serum total cholesterol on the risk of mortality in comparison with SBP or serum cholesterol 25 years previously, taking measurement error into account. The authors reanalyzed 35-year follow-up data on mortality due to coronary heart disease and stroke among subjects aged 65 years or more from nine cohorts of the Seven Countries Study. The two-step method of Tsiatis et al. (J Am Stat Assoc 1995;90:27-37) was used to adjust for regression dilution bias, and results were compared with those obtained using more commonly applied methods of adjustment for regression dilution bias. It was found that the commonly used univariate adjustment for regression dilution bias overestimates the effects of both SBP and cholesterol compared with multivariate methods. Also, the two-step method makes better use of the information available, resulting in smaller confidence intervals. Results comparing recent and past exposure indicated that past SBP is more important than recent SBP in terms of its effect on coronary heart disease mortality, while both recent and past values seem to be important for effects of cholesterol on coronary heart disease mortality and effects of SBP on stroke mortality. Associations between serum cholesterol concentration and risk of stroke mortality are weak.

  19. Individual Bayesian Information Matrix for Predicting Estimation Error and Shrinkage of Individual Parameters Accounting for Data Below the Limit of Quantification.

    Science.gov (United States)

    Nguyen, Thi Huyen Tram; Nguyen, Thu Thuy; Mentré, France

    2017-06-28

    In mixed models, the relative standard errors (RSE) and shrinkage of individual parameters can be predicted from the individual Bayesian information matrix (MBF). We proposed an approach accounting for data below the limit of quantification (LOQ) in MBF. MBF is the sum of the expectation of the individual Fisher information (MIF) which can be evaluated by First-Order linearization and the inverse of random effect variance. We expressed the individual information as a weighted sum of predicted MIF for every possible design composing of measurements above and/or below LOQ. When evaluating MIF, we derived the likelihood expressed as the product of the likelihood of observed data and the probability for data to be below LOQ. The relevance of RSE and shrinkage predicted by MBF in absence or presence of data below LOQ were evaluated by simulations, using a pharmacokinetic/viral kinetic model defined by differential equations. Simulations showed good agreement between predicted and observed RSE and shrinkage in absence or presence of data below LOQ. We found that RSE and shrinkage increased with sparser designs and with data below LOQ. The proposed method based on MBF adequately predicted individual RSE and shrinkage, allowing for evaluation of a large number of scenarios without extensive simulations.

  20. A Two-Step Method to Identify Positive Deviant Physician Organizations of Accountable Care Organizations with Robust Performance Management Systems.

    Science.gov (United States)

    Pimperl, Alexander F; Rodriguez, Hector P; Schmittdiel, Julie A; Shortell, Stephen M

    2017-04-06

    To identify positive deviant (PD) physician organizations of Accountable Care Organizations (ACOs) with robust performance management systems (PMSYS). Third National Survey of Physician Organizations (NSPO3, n = 1,398). Organizational and external factors from NSPO3 were analyzed. Linear regression estimated the association of internal and contextual factors on PMSYS. Two cutpoints (75th/90th percentiles) identified PDs with the largest residuals and highest PMSYS scores. A total of 65 and 41 PDs were identified using 75th and 90th percentiles cutpoints, respectively. The 90th percentile more strongly differentiated PDs from non-PDs. Having a high proportion of vulnerable patients appears to constrain PMSYS development. Our PD identification method increases the likelihood that PD organizations selected for in-depth inquiry are high-performing organizations that exceed expectations. © Health Research and Educational Trust.

  1. Quantitative analysis of the errors positioning of a multi leaf collimator for volumetric arcoterapia treatments; Analisis cuantitativo de los errores de posicionamiento de un colimador multilaminas para tratamientos de arcoterapia volumetrica

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Gonzalez, N.; Garcia Repiso, S.; Martin Rincon, C.; Cons Perez, N.; Saez Beltran, M.; Delgado Aparicio, J. M.; Perez alvarez, M. E.; Verde Velasco, J. M.; Ramos Pacho, J. A.; Sena Espinel, E. de

    2013-07-01

    The precision in the positioning of the multi leaf collimation system of a linear accelerator is critical, especially in treatments of IMRT, where small mistakes can cause relevant dosimetry discrepancies regarding the calculated plan. To assess the accuracy and repeatability of the blades positioning can be used controls, including the one known as fence test whose image pattern allows you to find anomalies in a visual way. The objective of this study is to develop a method which allows to quantify the positioning errors of the multi leaf collimator from this test. (Author)

  2. Correction of patient positioning errors based on in-line cone beam CTs: clinical implementation and first experiences

    Directory of Open Access Journals (Sweden)

    Häring Peter

    2006-05-01

    Full Text Available Abstract Background The purpose of the study was the clinical implementation of a kV cone beam CT (CBCT for setup correction in radiotherapy. Patients and methods For evaluation of the setup correction workflow, six tumor patients (lung cancer, sacral chordoma, head-and-neck and paraspinal tumor, and two prostate cancer patients were selected. All patients were treated with fractionated stereotactic radiotherapy, five of them with intensity modulated radiotherapy (IMRT. For patient fixation, a scotch cast body frame or a vacuum pillow, each in combination with a scotch cast head mask, were used. The imaging equipment, consisting of an x-ray tube and a flat panel imager (FPI, was attached to a Siemens linear accelerator according to the in-line approach, i.e. with the imaging beam mounted opposite to the treatment beam sharing the same isocenter. For dose delivery, the treatment beam has to traverse the FPI which is mounted in the accessory tray below the multi-leaf collimator. For each patient, a predefined number of imaging projections over a range of at least 200 degrees were acquired. The fast reconstruction of the 3D-CBCT dataset was done with an implementation of the Feldkamp-David-Kress (FDK algorithm. For the registration of the treatment planning CT with the acquired CBCT, an automatic mutual information matcher and manual matching was used. Results and discussion Bony landmarks were easily detected and the table shifts for correction of setup deviations could be automatically calculated in all cases. The image quality was sufficient for a visual comparison of the desired target point with the isocenter visible on the CBCT. Soft tissue contrast was problematic for the prostate of an obese patient, but good in the lung tumor case. The detected maximum setup deviation was 3 mm for patients fixated with the body frame, and 6 mm for patients positioned in the vacuum pillow. Using an action level of 2 mm translational error, a target point

  3. Development of an iterative reconstruction method to overcome 2D detector low resolution limitations in MLC leaf position error detection for 3D dose verification in IMRT

    NARCIS (Netherlands)

    Visser, Ruurd; Godart, J.; Wauben, D. J. L.; Langendijk, J. A.; van't Veld, A. A.; Korevaar, E. W.

    2016-01-01

    The objective of this study was to introduce a new iterative method to reconstruct multi leaf collimator (MLC) positions based on low resolution ionization detector array measurements and to evaluate its error detection performance. The iterative reconstruction method consists of a fluence model, a

  4. GPS定位信号随机误差自适应模型%RANDOM ERROR ADAPTIVE MODEL FOR GPS POSITIONING SIGNAL

    Institute of Scientific and Technical Information of China (English)

    杨海军; 郭美凤; 滕云鹤

    2000-01-01

    GPS, integrated with Inertial Navigation System, can improve theaccuracy of navigation and positioning. In order to apply the GPSsignal, the paper investigate the random error adaptive AR model of GPSpositioning signal, and improve the model and the algorithm based onnumerical analysis.

  5. Race-based rejection sensitivity partially accounts for the relationship between racial discrimination and distressing attenuated positive psychotic symptoms.

    Science.gov (United States)

    Anglin, Deidre M; Greenspoon, Michelle; Lighty, Quenesha; Ellman, Lauren M

    2016-10-01

    Self-reported experiences of racial discrimination have been associated with a continuum of psychotic experiences in racial and ethnic minority populations; however, the underlying mechanisms of this relationship are not yet clear. Race-based rejection sensitivity (RS-race) has been associated with thought intrusions about being the target of racial discrimination; therefore, the present study aimed to determine whether RS-race accounts for the relationship between racial discrimination and psychotic-like experiences in racial and ethnic minority populations. A sample of 644 young adults from a US urban, predominantly immigrant, and racial and ethnic minority population was administered a self-report inventory of psychosis risk (i.e. Prodromal Questionnaire (PQ) ), providing a dimensional assessment of the total number of attenuated positive psychotic symptoms experienced as distressing (APPS-distress). Participants also completed the Experiences of Discrimination Questionnaire and the Rejection Sensitivity Questionnaire-Race. Hierarchical linear regression analyses revealed that RS-race and racial discrimination were both significantly related to higher levels of APPS-distress. Bootstrapping analyses of indirect effects indicated that RS-race partially accounted for the relationship between racial discrimination and APPS-distress. Although the cross-sectional nature of the data limits conclusions about causal inference, our findings do suggest that racial discrimination and RS-race may both be important for understanding risk for distress in the psychotic spectrum among racial and ethnic minority young adults. Some individuals who report racial discrimination may be more vulnerable to APPS-distress in part because they are anxiously anticipating being racially slighted, and this should be explored further in prospective clinical high-risk studies. © 2014 Wiley Publishing Asia Pty Ltd.

  6. Accounting for Berkson and Classical Measurement Error in Radon Exposure Using a Bayesian Structural Approach in the Analysis of Lung Cancer Mortality in the French Cohort of Uranium Miners.

    Science.gov (United States)

    Hoffmann, Sabine; Rage, Estelle; Laurier, Dominique; Laroche, Pierre; Guihenneuc, Chantal; Ancelet, Sophie

    2017-02-01

    Many occupational cohort studies on underground miners have demonstrated that radon exposure is associated with an increased risk of lung cancer mortality. However, despite the deleterious consequences of exposure measurement error on statistical inference, these analyses traditionally do not account for exposure uncertainty. This might be due to the challenging nature of measurement error resulting from imperfect surrogate measures of radon exposure. Indeed, we are typically faced with exposure uncertainty in a time-varying exposure variable where both the type and the magnitude of error may depend on period of exposure. To address the challenge of accounting for multiplicative and heteroscedastic measurement error that may be of Berkson or classical nature, depending on the year of exposure, we opted for a Bayesian structural approach, which is arguably the most flexible method to account for uncertainty in exposure assessment. We assessed the association between occupational radon exposure and lung cancer mortality in the French cohort of uranium miners and found the impact of uncorrelated multiplicative measurement error to be of marginal importance. However, our findings indicate that the retrospective nature of exposure assessment that occurred in the earliest years of mining of this cohort as well as many other cohorts of underground miners might lead to an attenuation of the exposure-risk relationship. More research is needed to address further uncertainties in the calculation of lung dose, since this step will likely introduce important sources of shared uncertainty.

  7. Stereoscopic ground-based determination of the cloud base height: theory of camera position calibration with account for lens distortion

    Science.gov (United States)

    Chulichkov, Alexey I.; Postylyakov, Oleg V.

    2016-05-01

    For the reconstruction of some geometrical characteristics of clouds a method was developed based on taking pictures of the sky by a pair of digital photo cameras and subsequent processing of the obtained sequence of stereo frames to obtain the height of the cloud base. Since the directions of the optical axes of the stereo cameras are not exactly known, a procedure of adjusting of obtained frames was developed which use photographs of the night starry sky. In the second step, the method of the morphological analysis of images is used to determine the relative shift of the coordinates of some fragment of cloud. The shift is used to estimate the searched cloud base height. The proposed method can be used for automatic processing of stereo data and getting the cloud base height. The earlier paper described a mathematical model of stereophotography measurement, poses and solves the problem of adjusting of optical axes of the cameras in paraxial (first-order geometric optics) approximation and was applied for the central part of the sky frames. This paper describes the model of experiment which takes into account lens distortion in Seidel approximation (depending on the third order of the distance from optical axis). We developed procedure of simultaneous camera position calibration and estimation of parameters of lens distortion in Seidel approximation.

  8. The Relationship Between Implementation of School-Wide Positive Behavior Intervention and Supports and Performance on State Accountability Measures

    Directory of Open Access Journals (Sweden)

    Adriana M. Marin

    2013-10-01

    Full Text Available This study examined data from 96 schools in a Southeastern U.S. state participating in training and/or coaching on School-Wide Positive Behavioral Interventions and Supports (SWPBIS provided by the State Personnel Development Grant (SPDG in their state. Schools studied either received training only (“non-intensive” sites or training and on-site coaching (“intensive” sites. Fidelity of implementation was self-evaluated by both types of schools using the Benchmarks of Quality (BOQ. Some schools were also externally evaluated using the School-Wide Evaluation Tool (SET, with those scoring 80% or higher determined “model sites.” Using an independent sample t-test, analyses revealed statistically significant differences between intensive and nonintensive schools’ Quality of Distribution Index (QDI scores and between model sites and nonmodel sites on QDI scores. Correlations were performed to determine whether the fidelity of implementation of SWPBIS as measured by the BOQ was related to any of the state’s accountability measures: performance classification, QDI, or growth.

  9. Effect of translational and rotational errors on complex dose distributions with off-line and on-line position verification

    NARCIS (Netherlands)

    I.M. Lips; U.A. van der Heide; A.N.T.J. Kotte; M. van Vulpen; A. Bel

    2009-01-01

    PURPOSE: To investigate the influence of translational and rotational errors on prostate intensity-modulated radiotherapy (IMRT) with an integrated boost to the tumor and to evaluate the effect of the use of an on-line correction protocol. METHODS AND MATERIALS: For 19 patients, who had been treated

  10. Combining a differential global positioning system and double electric compass to improve multi-path error correction for a high-precision agricultural robotic vehicle

    Directory of Open Access Journals (Sweden)

    Chung-Teh Cheng

    2011-05-01

    Full Text Available This work has addressed the improving of the multi-path error in positioning systems by coupling a differential global positioning system (DGPS and double electric compass (DEC in the navigation system of an orchard robotic vehicle. A novel corrective algorithm model was applied to predicting the positioning coordinates during vehicle movement. The model manipulates a combination of data from both the DEC and the DGPS when the DGPS receiver is in problematic conditions in which the horizontal dilution of precision (HDOP is higher than three and the number of satellites is fewer than six. The constructed corrective algorithm model, the DEC and the DGPS together form a combined DGPS-DEC system that is inexpensive and of high-precision fitting for a vehicle-guiding instrument. In a field test in an outdoor environment with sections of tree shade in the guiding path, the combined DGPS-DEC positioning system effectively improved the reliability of positioning by correcting the DGPS multi-path error precisely to within 20 cm. By applying a mini-sprayer, further agricultural applications were feasible. In summary, the combined DGPS-DEC positioning system can obtain the correct position of a vehicle in real time for agricultural applications.

  11. MEMS陀螺仪零位误差分析与处理%Analysis and Processing on Zero Position Error of MEMS Gyroscope

    Institute of Scientific and Technical Information of China (English)

    陈旭光; 杨平; 陈意

    2012-01-01

    Study on zero position error of MEMS gyroscope has a great value on improving the accuracy of inertial navigation system. Allan variance analysis melhod was adopted to evaluate on zero position error of MEMS gyroscope. A kind of dynamic zero offset compensation algorithm was presented to eliminate the zero offset error. HDR( Heuristic Drift Reduction) was also improved and the compensation accuracy of original algorithm was increased effectively. Finally, Allan variance analysis method was adopted to evaluate on the compensated zero position error. Test had been done with the platform of gyro-equipped indoor mobile robot Voyager-lIA and the results show precision was increased significantly with the improved algorithm.%研究微机械陀螺仪的零位误差对提高惯性导航精度具有重要意义.采用Allan方差分析法对MEMS陀螺仪的零位误差做了综合评定,提出了一种动态的零值偏移误差补偿算法来滤除陀螺仪的零值偏移误差,还对启发式漂移消减法HDR(Heuristic Drift Reduction)做了改进,有效地提高了原算法的补偿精度.最后,再次采用Allan方差分析法对补偿后的零位误差进行评定,并以Voyager-IIA机器人为平台进行试验,结果证明了改进后的算法能显著的提高陀螺仪的输出精度.

  12. Previous estimates of mitochondrial DNA mutation level variance did not account for sampling error: comparing the mtDNA genetic bottleneck in mice and humans.

    Science.gov (United States)

    Wonnapinij, Passorn; Chinnery, Patrick F; Samuels, David C

    2010-04-09

    In cases of inherited pathogenic mitochondrial DNA (mtDNA) mutations, a mother and her offspring generally have large and seemingly random differences in the amount of mutated mtDNA that they carry. Comparisons of measured mtDNA mutation level variance values have become an important issue in determining the mechanisms that cause these large random shifts in mutation level. These variance measurements have been made with samples of quite modest size, which should be a source of concern because higher-order statistics, such as variance, are poorly estimated from small sample sizes. We have developed an analysis of the standard error of variance from a sample of size n, and we have defined error bars for variance measurements based on this standard error. We calculate variance error bars for several published sets of measurements of mtDNA mutation level variance and show how the addition of the error bars alters the interpretation of these experimental results. We compare variance measurements from human clinical data and from mouse models and show that the mutation level variance is clearly higher in the human data than it is in the mouse models at both the primary oocyte and offspring stages of inheritance. We discuss how the standard error of variance can be used in the design of experiments measuring mtDNA mutation level variance. Our results show that variance measurements based on fewer than 20 measurements are generally unreliable and ideally more than 50 measurements are required to reliably compare variances with less than a 2-fold difference.

  13. SU-E-T-132: Dosimetric Impact of Positioning Errors in Hypo-Fractionated Cranial Radiation Therapy Using Frameless Stereotactic BrainLAB System

    Energy Technology Data Exchange (ETDEWEB)

    Keeling, V; Jin, H; Ali, I; Ahmad, S [Oklahoma Univ. Health Science Ctr., Oklahoma City, OK (United States)

    2014-06-01

    Purpose: To determine dosimetric impact of positioning errors in the stereotactic hypo-fractionated treatment of intracranial lesions using 3Dtransaltional and 3D-rotational corrections (6D) frameless BrainLAB ExacTrac X-Ray system. Methods: 20 cranial lesions, treated in 3 or 5 fractions, were selected. An infrared (IR) optical positioning system was employed for initial patient setup followed by stereoscopic kV X-ray radiographs for position verification. 6D-translational and rotational shifts were determined to correct patient position. If these shifts were above tolerance (0.7 mm translational and 1° rotational), corrections were applied and another set of X-rays was taken to verify patient position. Dosimetric impact (D95, Dmin, Dmax, and Dmean of planning target volume (PTV) compared to original plans) of positioning errors for initial IR setup (XC: Xray Correction) and post-correction (XV: X-ray Verification) was determined in a treatment planning system using a method proposed by Yue et al. (Med. Phys. 33, 21-31 (2006)) with 3D-translational errors only and 6D-translational and rotational errors. Results: Absolute mean translational errors (±standard deviation) for total 92 fractions (XC/XV) were 0.79±0.88/0.19±0.15 mm (lateral), 1.66±1.71/0.18 ±0.16 mm (longitudinal), 1.95±1.18/0.15±0.14 mm (vertical) and rotational errors were 0.61±0.47/0.17±0.15° (pitch), 0.55±0.49/0.16±0.24° (roll), and 0.68±0.73/0.16±0.15° (yaw). The average changes (loss of coverage) in D95, Dmin, Dmax, and Dmean were 4.5±7.3/0.1±0.2%, 17.8±22.5/1.1±2.5%, 0.4±1.4/0.1±0.3%, and 0.9±1.7/0.0±0.1% using 6Dshifts and 3.1±5.5/0.0±0.1%, 14.2±20.3/0.8±1.7%, 0.0±1.2/0.1±0.3%, and 0.7±1.4/0.0±0.1% using 3D-translational shifts only. The setup corrections (XC-XV) improved the PTV coverage by 4.4±7.3% (D95) and 16.7±23.5% (Dmin) using 6D adjustment. Strong correlations were observed between translation errors and deviations in dose coverage for XC. Conclusion

  14. Measurement Errors Arising When Using Distances in Microeconometric Modelling and the Individuals’ Position Is Geo-Masked for Confidentiality

    Directory of Open Access Journals (Sweden)

    Giuseppe Arbia

    2015-10-01

    Full Text Available In many microeconometric models we use distances. For instance, in modelling the individual behavior in labor economics or in health studies, the distance from a relevant point of interest (such as a hospital or a workplace is often used as a predictor in a regression framework. However, in order to preserve confidentiality, spatial micro-data are often geo-masked, thus reducing their quality and dramatically distorting the inferential conclusions. In particular in this case, a measurement error is introduced in the independent variable which negatively affects the properties of the estimators. This paper studies these negative effects, discusses their consequences, and suggests possible interpretations and directions to data producers, end users, and practitioners.

  15. Sphero-cylindrical error for oblique gaze as a function of the position of the centre of rotation of the eye.

    Science.gov (United States)

    Perches, Sara; Ares, Jorge; Collados, Victoria; Palos, Fernando

    2013-07-01

    New designs of ophthalmic lenses customised for particular wearing conditions (e.g., vertex distance or wrap tilt angle) have emerged during the last few years. However, there is limited information about the extent of any improvement in visual quality of these products. The aim of this work was to determine whether customisation according to the centre of rotation of the eye (CRE) improves visual quality for oblique gaze in monofocal spherical lenses. Conventional spherical lenses were designed by numerical ray tracing with back vertex powers (BVP) ranging from +8 to -8 dioptres (D) and base curves from 0 to 8 D. The wavefront error at oblique gaze (40°) was computed for each design with CRE positions from 20 to 35 mm. Sphero-cylindrical (SC) error was calculated using wavefront Zernike coefficients, considering only monochromatic aberrations. Visual acuity in logMAR was estimated following the Raasch empirical regression model. SC error and visual acuity maps were calculated for each BVP as a function of base curves and CRE in a graded colour scale. From SC error maps maximum spherical and cylindrical errors (MSE and MCE) of 1.49 D and -1.24 D respectively were found for BVP from 0 to -2 D, 2.27 D and -1.90 D for BVP from -2 D to -4 D, 2.59 D and -2.20 D for lenses from -4 D to -6 D and 2.63 D and -2.28 D for lenses from -6 D to -8 D. Concerning positive lenses, we obtained MSE and MCE of 0.37 D and -1.35 D respectively for lenses from 0 D to +2 D, 0.39 D and -2.23 D for lenses from +2 D to +4 D and 0.36 D and -2.73 D for lenses from +4 D to +6 D. Regarding visual acuity maps for 40° oblique gaze, significant loss of visual acuity (>0.30 logMAR, Snellen 6/12, 20/40, decimal 0.50) was found for BVP as low as -2 D. Clinically negligible high order aberration levels (equivalent spherical power high SC error when they were designed with low bases. However, high BVP negative lenses with low SC error were found for medium bases and low

  16. Numerical optimization with computational errors

    CERN Document Server

    Zaslavski, Alexander J

    2016-01-01

    This book studies the approximate solutions of optimization problems in the presence of computational errors. A number of results are presented on the convergence behavior of algorithms in a Hilbert space; these algorithms are examined taking into account computational errors. The author illustrates that algorithms generate a good approximate solution, if computational errors are bounded from above by a small positive constant. Known computational errors are examined with the aim of determining an approximate solution. Researchers and students interested in the optimization theory and its applications will find this book instructive and informative. This monograph contains 16 chapters; including a chapters devoted to the subgradient projection algorithm, the mirror descent algorithm, gradient projection algorithm, the Weiszfelds method, constrained convex minimization problems, the convergence of a proximal point method in a Hilbert space, the continuous subgradient method, penalty methods and Newton’s meth...

  17. Sigma pole position and errors of a once and twice subtracted dispersive analysis of pi-pi scattering data

    CERN Document Server

    Kaminski, R; Grynkiewicz, P; Peláez, J R

    2009-01-01

    We show how the new precise data on kaon decays together with forward dispersion relations, sum rules and once- and twice-subtracted Roy's equations allow for a precise determination of the sigma meson pole position. We present a comparison and a study of the different sources of uncertainties when using either once- or twice-subtracted Roy's equations to analyze the data. Finally we present a preliminary determination of the sigma pole from the constrained dispersive data analysis.

  18. Double Station Cooperative Reconnaissance and Positioning Error Analysis%双机协同交叉定位算法及误差分析

    Institute of Scientific and Technical Information of China (English)

    贺刚; 赵雷鸣; 刘昊; 樊雷; 黄秦煌

    2015-01-01

    针对双机协同对地面或海面缓慢移动目标进行精确定位的需求,给出了双站协同定位的工作原理、定位流程及模型,从理论上推导了三维空间中双机协同交叉定位算法中的误差关系式,并详细分析了影响定位误差的各种因素,最后通过仿真验证了理论推导的正确性.研究结果为双机协同对敌目标精确定位的实际应用提供了理论支持.%Be demand for precise positioning dual synergistic move slowly on the ground or sea targets,this paper presents a dual station co-location of works,positioning processes and models, Theoretically derived from three-dimensional space dual synergistic cross-localization algorithm errors in the relationship,And a detailed analysis of the various factors influences the positioning error,and finally the simulation verify the theoretical derivation is correct. The results for the two-machine collaboration pinpoint enemy targets practical application provides theoretical support.

  19. Sigma pole position and errors of a once and twice subtracted dispersive analysis of pi-pi scattering data

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, R. [Department of Theoretical Physics, H. Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow (Poland); Garcia-Martin, R. [Departamento de Fisica Teorica, II (Metodos Matematicos), Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, E-28040, Madrid (Spain); Grynkiewicz, P. [ul. Paulinska, 6/18 Krakow 31-065 (Poland); Pelaez, J.R. [Departamento de Fisica Teorica, II (Metodos Matematicos), Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, E-28040, Madrid (Spain)

    2009-01-15

    We show how the new precise data on kaon decays together with forward dispersion relations, sum rules and once- and twice-subtracted Roy's equations allow for a precise determination of the sigma meson pole position. We present a comparison and a study of the different sources of uncertainties when using either once- or twice-subtracted Roy's equations to analyze the data. Finally we present a preliminary determination of the {sigma} pole from the constrained dispersive data analysis.

  20. Identity, small stories and interpretative repertoires in research interviews. An account of market researchers’ discursive positioning strategies

    Directory of Open Access Journals (Sweden)

    Cosmin Toth

    2014-12-01

    Full Text Available My main purpose in this paper is to illustrate how participants in a research interview occasioned conversation make use of two important discursive devices, namely: small stories and interpretative repertoires for positioning during interaction in order to foster certain situated identity claims. The premises I work with in this paper are that identity is a practiced situated accomplishment, that small stories are devices employed frequently for identity work that are no less important than extended autobiographical expositions, and that interpretative repertoires are practiced ways of speaking that allow participants to manage their positions in certain ways. Moreover, I will try to show that positioning by means of small stories and interpretative repertoires should be understood in direct relation with the identities and other membership categories made relevant by the interviewer. When participants’ positions are conflicting or miss-aligned, a more pronounced identity work is employed on the part of the interviewee, sustained by certain repertoires’ management strategies: alternation, nuancing, or rejecting certain repertoires.

  1. MuSE: accounting for tumor heterogeneity using a sample-specific error model improves sensitivity and specificity in mutation calling from sequencing data.

    Science.gov (United States)

    Fan, Yu; Xi, Liu; Hughes, Daniel S T; Zhang, Jianjun; Zhang, Jianhua; Futreal, P Andrew; Wheeler, David A; Wang, Wenyi

    2016-01-01

    Subclonal mutations reveal important features of the genetic architecture of tumors. However, accurate detection of mutations in genetically heterogeneous tumor cell populations using next-generation sequencing remains challenging. We develop MuSE ( http://bioinformatics.mdanderson.org/main/MuSE ), Mutation calling using a Markov Substitution model for Evolution, a novel approach for modeling the evolution of the allelic composition of the tumor and normal tissue at each reference base. MuSE adopts a sample-specific error model that reflects the underlying tumor heterogeneity to greatly improve the overall accuracy. We demonstrate the accuracy of MuSE in calling subclonal mutations in the context of large-scale tumor sequencing projects using whole exome and whole genome sequencing.

  2. Can the Pro-Drop Parameter Account for All the Errors in the Acquisition of Non-Referential "It" in L2 English?

    Science.gov (United States)

    Antonova-Ünlü, Elena

    2015-01-01

    Numerous studies, examining the acquisition of non-referential it in [-pro-drop] English by learners of [+pro-drop] languages, have revealed that their participants omit non-referential subjects in English if their L1 allows null-subject position. However, due to the specificity of their focus, these studies have not considered other difficulties…

  3. Error induced by the estimation of the corneal power and the effective lens position with a rotationally asymmetric refractive multifocal intraocular lens

    Institute of Scientific and Technical Information of China (English)

    David; P.Piero; Vicente; J.Camps; María; L.Ramón; Verónica; Mateo; Rafael; J.Pérez-Cambrodí

    2015-01-01

    AIM : To evaluate the prediction error in intraocular lens(IOL) power calculation for a rotationally asymmetric refractive multifocal IOL and the impact on this error of the optimization of the keratometric estimation of the corneal power and the prediction of the effective lens position(ELP).METHODS: Retrospective study including a total of 25 eyes of 13 patients(age, 50 to 83y) with previous cataract surgery with implantation of the Lentis Mplus LS-312 IOL(Oculentis Gmb H, Germany). In all cases, an adjusted IOL power(P IOLadj) was calculated based on Gaussian optics using a variable keratometric index value(n kadj) for the estimation of the corneal power(P kadj) and on a new value for ELP(ELP adj) obtained by multiple regression analysis.This P IOLadj was compared with the IOL power implanted(P IOLReal) and the value proposed by three conventional formulas(Haigis, Hoffer Q and Holladay Ⅰ).RESULTS: P IOLReal was not significantly different than P IOLadj and Holladay IOL power(P >0.05). In the Bland and Altman analysis, P IOLadj showed lower mean difference(-0.07 D) and limits of agreement(of 1.47 and-1.61 D)when compared to P IOLReal than the IOL power value obtained with the Holladay formula. Furthermore, ELP adj was significantly lower than ELP calculated with other conventional formulas(P <0.01) and was found to be dependent on axial length, anterior chamber depth and P kadj. CONCLUSION: Refractive outcomes after cataract surgery with implantation of the multifocal IOL Lentis Mplus LS-312 can be optimized by minimizing thekeratometric error and by estimating ELP using a mathematical expression dependent on anatomical factors.

  4. Detecting and accounting for multiple sources of positional variance in peak list registration analysis and spin system grouping.

    Science.gov (United States)

    Smelter, Andrey; Rouchka, Eric C; Moseley, Hunter N B

    2017-08-16

    Peak lists derived from nuclear magnetic resonance (NMR) spectra are commonly used as input data for a variety of computer assisted and automated analyses. These include automated protein resonance assignment and protein structure calculation software tools. Prior to these analyses, peak lists must be aligned to each other and sets of related peaks must be grouped based on common chemical shift dimensions. Even when programs can perform peak grouping, they require the user to provide uniform match tolerances or use default values. However, peak grouping is further complicated by multiple sources of variance in peak position limiting the effectiveness of grouping methods that utilize uniform match tolerances. In addition, no method currently exists for deriving peak positional variances from single peak lists for grouping peaks into spin systems, i.e. spin system grouping within a single peak list. Therefore, we developed a complementary pair of peak list registration analysis and spin system grouping algorithms designed to overcome these limitations. We have implemented these algorithms into an approach that can identify multiple dimension-specific positional variances that exist in a single peak list and group peaks from a single peak list into spin systems. The resulting software tools generate a variety of useful statistics on both a single peak list and pairwise peak list alignment, especially for quality assessment of peak list datasets. We used a range of low and high quality experimental solution NMR and solid-state NMR peak lists to assess performance of our registration analysis and grouping algorithms. Analyses show that an algorithm using a single iteration and uniform match tolerances approach is only able to recover from 50 to 80% of the spin systems due to the presence of multiple sources of variance. Our algorithm recovers additional spin systems by reevaluating match tolerances in multiple iterations. To facilitate evaluation of the

  5. Super Short Baseline Underwater Acoustic Positioning Supported by Inertial Navigation Data Using Spread Spectrum Communication for Autonomous Underwater Vehicle and Error Analysis in Deep Water

    Science.gov (United States)

    Watanabe, Yoshitaka; Ochi, Hiroshi; Shimura, Takuya; Hattori, Takehito

    2009-07-01

    A tracking and positioning method achieved by integration of the super short baseline (SSBL) and inertial navigation system (INS) data for an autonomous underwater vehicle (AUV) is introduced. The proposed method uses a continuous acoustic signal as the response signal from the target AUV. The INS data obtained in the AUV is transmitted with the acoustic signal by the direct-sequence spread spectrum (DSSS) technique and the SSBL estimation is achieved using the same signal. The error of the SSBL, particularly the influence of a multipath, was analyzed. The use of a continuous signal showed that the multipath is influential even if its level is small relative to the direct wave. This influence was observed under actual conditions in an ocean experiment in a deep-water area. The proposed method was confirmed to be available and useful by simulations and experimental results.

  6. When errors are rewarding

    NARCIS (Netherlands)

    Bruijn, E.R.A. de; Lange, F.P. de; Cramon, D.Y. von; Ullsperger, M.

    2009-01-01

    For social beings like humans, detecting one's own and others' errors is essential for efficient goal-directed behavior. Although one's own errors are always negative events, errors from other persons may be negative or positive depending on the social context. We used neuroimaging to disentangle br

  7. Gas-cooled reactor programs. Fuel-management positioning and accounting module: FUELMANG Version V1. 11, September 1981

    Energy Technology Data Exchange (ETDEWEB)

    Medlin, T.W.; Hill, K.L.; Johnson, G.L.; Jones, J.E.; Vondy, D.R.

    1982-01-01

    This report documents the code module FUELMANG for fuel management of a reactor. This code may be used to position fuel during the calculation of a reactor history, maintain a mass balance history of the fuel movement, and calculate the unit fuel cycle component of the electrical generation cost. In addition to handling fixed feed fuel without recycle, provision has been made for fuel recycle with various options applied to the recycled fuel. A continuous fueling option is also available with the code. A major edit produced by the code is a detailed summary of the mass balance history of the reactor and a fuel cost analysis of that mass balance history. This code is incorporated in the system containing the VENTURE diffusion theory neutronics code for routine use. Fuel movement according to prescribed instructions is performed without the access of additional user input data during the calculation of a reactor operating history. Local application has been primarily for analysis of the performance of gas-cooled thermal reactor core concepts.

  8. Management accounting control systems’ impact on joint venture performance: the positive role of managers’ experience

    Directory of Open Access Journals (Sweden)

    Marcela Porporato

    2016-04-01

    Full Text Available This study explores the impact of management planning and control systems’ use on 50/50 joint venture’s performance operating in the auto industry. It explores the effect of the use of these systems by organizations operating in turbulent environments through an analysis of the impact that managers’ experience has on the intensity and purpose of use of management planning and control systems. The study of this topic emerges as the results of previous exploratory field studies of JVs (Groot and Merchant 2000 and of JVs in the auto industry (Porporato 2013 where it is suggested that management planning and control systems’ do not have a central effect on JV performance. A survey of 35 international JVs with shared ownership (50/50 shows that organizational performance improves when the uncertainty of factors perceived as controllable by managers is reduced; a factor is perceived as controllable when the manager has a high level of past experience with it. Uncertainty as it is defined by Galbraith (1973 is reduced through an intensive use of management planning and control systems, which in turn positively affects organizational performance.

  9. SU-E-T-318: The Effect of Patient Positioning Errors On Target Coverage and Cochlear Dose in Stereotactic Radiosurgery Treatment of Acoustic Neuromas

    Energy Technology Data Exchange (ETDEWEB)

    Dellamonica, D.; Luo, G.; Ding, G. [Vanderbilt University, Nashville, TN (United States)

    2014-06-01

    Purpose: Setup errors on the order of millimeters may cause under-dosing of targets and significant changes in dose to critical structures especially when planning with tight margins in stereotactic radiosurgery. This study evaluates the effects of these types of patient positioning uncertainties on planning target volume (PTV) coverage and cochlear dose for stereotactic treatments of acoustic neuromas. Methods: Twelve acoustic neuroma patient treatment plans were retrospectively evaluated in Brainlab iPlan RT Dose 4.1.3. All treatment beams were shaped by HDMLC from a Varian TX machine. Seven patients had planning margins of 2mm, five had 1–1.5mm. Six treatment plans were created for each patient simulating a 1mm setup error in six possible directions: anterior-posterior, lateral, and superiorinferior. The arcs and HDMLC shapes were kept the same for each plan. Change in PTV coverage and mean dose to the cochlea was evaluated for each plan. Results: The average change in PTV coverage for the 72 simulated plans was −1.7% (range: −5 to +1.1%). The largest average change in coverage was observed for shifts in the patient's superior direction (−2.9%). The change in mean cochlear dose was highly dependent upon the direction of the shift. Shifts in the anterior and superior direction resulted in an average increase in dose of 13.5 and 3.8%, respectively, while shifts in the posterior and inferior direction resulted in an average decrease in dose of 17.9 and 10.2%. The average change in dose to the cochlea was 13.9% (range: 1.4 to 48.6%). No difference was observed based on the size of the planning margin. Conclusion: This study indicates that if the positioning uncertainty is kept within 1mm the setup errors may not result in significant under-dosing of the acoustic neuroma target volumes. However, the change in mean cochlear dose is highly dependent upon the direction of the shift.

  10. TU-AB-201-05: Automatic Adaptive Per-Operative Re-Planning for HDR Prostate Brachytherapy - a Simulation Study On Errors in Needle Positioning

    Energy Technology Data Exchange (ETDEWEB)

    Borot de Battisti, M; Maenhout, M; Lagendijk, J J W; Van Vulpen, M; Moerland, M A [University Medical Center Utrecht, Dept. of Radiotherapy, Utrecht (Netherlands); Senneville, B Denis de [University Medical Center Utrecht, Dept. of Radiotherapy, Utrecht (Netherlands); IMB, UMR 5251 CNRS/University of Bordeaux (France); Hautvast, G; Binnekamp, D [Philips Group Innovation - Biomedical Systems, Eindhoven (Netherlands)

    2015-06-15

    Purpose: To develop adaptive planning with feedback for MRI-guided focal HDR prostate brachytherapy with a single divergent needle robotic implant device. After each needle insertion, the dwell positions for that needle are calculated and the positioning of remaining needles and dosimetry are both updated based on MR imaging. Methods: Errors in needle positioning may occur due to inaccurate needle insertion (caused by e.g. the needle’s bending) and unpredictable changes in patient anatomy. Consequently, the dose plan quality might dramatically decrease compared to the preplan. In this study, a procedure was developed to re-optimize, after each needle insertion, the remaining needle angulations, source positions and dwell times in order to obtain an optimal coverage (D95% PTV>19 Gy) without exceeding the constraints of the organs at risk (OAR) (D10% urethra<21 Gy, D1cc bladder<12 Gy and D1cc rectum<12 Gy). Complete HDR procedures with 6 needle insertions were simulated for a patient MR-image set with PTV, prostate, urethra, bladder and rectum delineated. Random angulation errors, modeled by a Gaussian distribution (standard deviation of 3 mm at the needle’s tip), were generated for each needle insertion. We compared the final dose parameters for the situations (I) without re-optimization and (II) with the automatic feedback. Results: The computation time of replanning was below 100 seconds on a current desk computer. For the patient tested, a clinically acceptable dose plan was achieved while applying the automatic feedback (median(range) in Gy, D95% PTV: 19.9(19.3–20.3), D10% urethra: 13.4(11.9–18.0), D1cc rectum: 11.0(10.7–11.6), D1cc bladder: 4.9(3.6–6.8)). This was not the case without re-optimization (median(range) in Gy, D95% PTV: 19.4(14.9–21.3), D10% urethra: 12.6(11.0–15.7), D1cc rectum: 10.9(8.9–14.1), D1cc bladder: 4.8(4.4–5.2)). Conclusion: An automatic guidance strategy for HDR prostate brachytherapy was developed to compensate

  11. [Survey in hospitals. Nursing errors, error culture and error management].

    Science.gov (United States)

    Habermann, Monika; Cramer, Henning

    2010-09-01

    Knowledge on errors is important to design safe nursing practice and its framework. This article presents results of a survey on this topic, including data of a representative sample of 724 nurses from 30 German hospitals. Participants predominantly remembered medication errors. Structural and organizational factors were rated as most important causes of errors. Reporting rates were considered low; this was explained by organizational barriers. Nurses in large part expressed having suffered from mental problems after error events. Nurses' perception focussing on medication errors seems to be influenced by current discussions which are mainly medication-related. This priority should be revised. Hospitals' risk management should concentrate on organizational deficits and positive error cultures. Decision makers are requested to tackle structural problems such as staff shortage.

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

    Directory of Open Access Journals (Sweden)

    Tanja eEndrass

    2012-06-01

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

  13. Hemispheric Asymmetries in Striatal Reward Responses Relate to Approach-Avoidance Learning and Encoding of Positive-Negative Prediction Errors in Dopaminergic Midbrain Regions.

    Science.gov (United States)

    Aberg, Kristoffer Carl; Doell, Kimberly C; Schwartz, Sophie

    2015-10-28

    Some individuals are better at learning about rewarding situations, whereas others are inclined to avoid punishments (i.e., enhanced approach or avoidance learning, respectively). In reinforcement learning, action values are increased when outcomes are better than predicted (positive prediction errors [PEs]) and decreased for worse than predicted outcomes (negative PEs). Because actions with high and low values are approached and avoided, respectively, individual differences in the neural encoding of PEs may influence the balance between approach-avoidance learning. Recent correlational approaches also indicate that biases in approach-avoidance learning involve hemispheric asymmetries in dopamine function. However, the computational and neural mechanisms underpinning such learning biases remain unknown. Here we assessed hemispheric reward asymmetry in striatal activity in 34 human participants who performed a task involving rewards and punishments. We show that the relative difference in reward response between hemispheres relates to individual biases in approach-avoidance learning. Moreover, using a computational modeling approach, we demonstrate that better encoding of positive (vs negative) PEs in dopaminergic midbrain regions is associated with better approach (vs avoidance) learning, specifically in participants with larger reward responses in the left (vs right) ventral striatum. Thus, individual dispositions or traits may be determined by neural processes acting to constrain learning about specific aspects of the world.

  14. Strength and stability analysis of load-bearing structures of a high-rise building with account for actual positions of reinforced concrete structural members

    Directory of Open Access Journals (Sweden)

    Belostotskiy Aleksandr Mikhaylovich

    2015-04-01

    Full Text Available The given paper is devoted to strength and stability analysis of load-bearing structures of a high-rise (54-storey building with allowance for actual positions of reinforced concrete structural members (columns and walls. Finite element method (FEM is used for structural analysis. The authors present formulations of problems, governing equations, information about basic three-dimensional finite element models (so-called “design” (ideal model, the first “actual” model (taking into account the deviations of positions of columns from the project and the second “actual” model (taking into account the deviations of positions of walls from the project of the coupled system “high-rise building - foundation” within ANSYS Mechanical software and their verification, numerical approach to structural analysis and corresponding solvers. Finite element models include mainly 4-node structural shell elements (suitable for analyzing foundation slabs, floor slabs and load-bearing walls and three-dimensional 2-node beam elements (suitable for analyzing beams and columns, special spring-damper elements and multipoint constraint elements. Detailed finite element mesh on the bottom foundation slab is agreed with the location of piles. The advanced model of Prof. Yu.K. Zaretsky is used for approximation of soil behavior. Construction sequence and various types of nonlinearities are taken into account. The results of modal analysis, static and dynamic analysis with various load combinations (gravity load, facade load, dead (constant loads, temporary loads, wind load, snow load, crown load etc. are considered, the results of the regulatory assessment of the strength of structures (obtained with the use of corresponding software in accordance with design codes of the Russian Federation are under consideration as well. The corresponding displacements, stresses, natural vibration frequencies can be used for research and development of the correct monitoring

  15. A study of respiration-correlated cone-beam CT scans to correct target positioning errors in radiotherapy of thoracic cancer

    Science.gov (United States)

    Santoro, J. P.; McNamara, J.; Yorke, E.; Pham, H.; Rimner, A.; Rosenzweig, K. E.; Mageras, G. S.

    2012-01-01

    Purpose: There is increasingly widespread usage of cone-beam CT (CBCT) for guiding radiation treatment in advanced-stage lung tumors, but difficulties associated with daily CBCT in conventionally fractionated treatments include imaging dose to the patient, increased workload and longer treatment times. Respiration-correlated cone-beam CT (RC-CBCT) can improve localization accuracy in mobile lung tumors, but further increases the time and workload for conventionally fractionated treatments. This study investigates whether RC-CBCT-guided correction of systematic tumor deviations in standard fractionated lung tumor radiation treatments is more effective than 2D image-based correction of skeletal deviations alone. A second study goal compares respiration-correlated vs respiration-averaged images for determining tumor deviations. Methods: Eleven stage II–IV nonsmall cell lung cancer patients are enrolled in an IRB-approved prospective off-line protocol using RC-CBCT guidance to correct for systematic errors in GTV position. Patients receive a respiration-correlated planning CT (RCCT) at simulation, daily kilovoltage RC-CBCT scans during the first week of treatment and weekly scans thereafter. Four types of correction methods are compared: (1) systematic error in gross tumor volume (GTV) position, (2) systematic error in skeletal anatomy, (3) daily skeletal corrections, and (4) weekly skeletal corrections. The comparison is in terms of weighted average of the residual GTV deviations measured from the RC-CBCT scans and representing the estimated residual deviation over the treatment course. In the second study goal, GTV deviations computed from matching RCCT and RC-CBCT are compared to deviations computed from matching respiration-averaged images consisting of a CBCT reconstructed using all projections and an average-intensity-projection CT computed from the RCCT. Results: Of the eleven patients in the GTV-based systematic correction protocol, two required no correction

  16. Assessment on tracking error performance of Cascade P/PI, NPID and N-Cascade controller for precise positioning of xy table ballscrew drive system

    Science.gov (United States)

    Abdullah, L.; Jamaludin, Z.; Rafan, N. A.; Jamaludin, J.; Chiew, T. H.

    2013-12-01

    At present, positioning plants in machine tools are looking for high degree of accuracy and robustness attributes for the purpose of compensating various disturbance forces. The objective of this paper is to assess the tracking performance of Cascade P/PI, Nonlinear PID (NPID) and Nonlinear cascade (N-Cascade) controller with the existence of disturbance forces in the form of cutting forces. Cutting force characteristics at different cutting parameters; such as spindle speed rotations is analysed using Fast Fourier Transform. The tracking performance of a Nonlinear cascade controller in presence of these cutting forces is compared with NPID controller and Cascade P/PI controller. Robustness of these controllers in compensating different cutting characteristics is compared based on reduction in the amplitudes of cutting force harmonics using Fast Fourier Transform. It is found that the N-cascade controller performs better than both NPID controller and Cascade P/PI controller. The average percentage error reduction between N-cascade controller and Cascade P/PI controller is about 65% whereas the average percentage error reduction between cascade controller and NPID controller is about 82% at spindle speed of 3000 rpm spindle speed rotation. The finalized design of N-cascade controller could be utilized further for machining application such as milling process. The implementation of N-cascade in machine tools applications will increase the quality of the end product and the productivity in industry by saving the machining time. It is suggested that the range of the spindle speed could be made wider to accommodate the needs for high speed machining.

  17. Proofreading for word errors.

    Science.gov (United States)

    Pilotti, Maura; Chodorow, Martin; Agpawa, Ian; Krajniak, Marta; Mahamane, Salif

    2012-04-01

    Proofreading (i.e., reading text for the purpose of detecting and correcting typographical errors) is viewed as a component of the activity of revising text and thus is a necessary (albeit not sufficient) procedural step for enhancing the quality of a written product. The purpose of the present research was to test competing accounts of word-error detection which predict factors that may influence reading and proofreading differently. Word errors, which change a word into another word (e.g., from --> form), were selected for examination because they are unlikely to be detected by automatic spell-checking functions. Consequently, their detection still rests mostly in the hands of the human proofreader. Findings highlighted the weaknesses of existing accounts of proofreading and identified factors, such as length and frequency of the error in the English language relative to frequency of the correct word, which might play a key role in detection of word errors.

  18. 考虑加工偏心误差的齿轮建模方法研究%Research on a Gear Modeling Method Taking Account into Machining Eccentric Error

    Institute of Scientific and Technical Information of China (English)

    王斌; 张义民

    2012-01-01

    It has great significance to build the parametric model of gear with machining error when studying the transmission system of dynamics turret. Firstly, deep research on dedendum transition curve has been included in the building of parameter equation in the whole profile curve of straight spur gear.At the same time ,a simple method which takes account into machining eccentric error has been put forward.Then, a plug-in for building gear model with machining eccentric error is established based on NX,and that could generate model quickly.Finally ,the metrology of generation model shows that its precision satisfies the use requirement.%建立含有加工误差的齿轮参数化模型,对于研究动力刀塔传动系统精度具有重要意义.首先,建立直齿圆柱齿轮全齿廓曲线参数方程,其中包含对齿根过渡曲线的深入研究.同时,提出一种简便的考虑加工偏心误差的齿轮建模方法.其次,在NX平台上开发了考虑加工偏心误差的齿轮建模插件,能够快速生成齿轮模型.最后,生成的齿轮模型经检测,精度能够满足使用要求.

  19. Analyzing temozolomide medication errors: potentially fatal.

    Science.gov (United States)

    Letarte, Nathalie; Gabay, Michael P; Bressler, Linda R; Long, Katie E; Stachnik, Joan M; Villano, J Lee

    2014-10-01

    The EORTC-NCIC regimen for glioblastoma requires different dosing of temozolomide (TMZ) during radiation and maintenance therapy. This complexity is exacerbated by the availability of multiple TMZ capsule strengths. TMZ is an alkylating agent and the major toxicity of this class is dose-related myelosuppression. Inadvertent overdose can be fatal. The websites of the Institute for Safe Medication Practices (ISMP), and the Food and Drug Administration (FDA) MedWatch database were reviewed. We searched the MedWatch database for adverse events associated with TMZ and obtained all reports including hematologic toxicity submitted from 1st November 1997 to 30th May 2012. The ISMP describes errors with TMZ resulting from the positioning of information on the label of the commercial product. The strength and quantity of capsules on the label were in close proximity to each other, and this has been changed by the manufacturer. MedWatch identified 45 medication errors. Patient errors were the most common, accounting for 21 or 47% of errors, followed by dispensing errors, which accounted for 13 or 29%. Seven reports or 16% were errors in the prescribing of TMZ. Reported outcomes ranged from reversible hematological adverse events (13%), to hospitalization for other adverse events (13%) or death (18%). Four error reports lacked detail and could not be categorized. Although the FDA issued a warning in 2003 regarding fatal medication errors and the product label warns of overdosing, errors in TMZ dosing occur for various reasons and involve both healthcare professionals and patients. Overdosing errors can be fatal.

  20. Impact of error management culture on knowledge performance in professional service firms

    Directory of Open Access Journals (Sweden)

    Tabea Scheel

    2014-01-01

    Full Text Available Knowledge is the most crucial resource of the 21st century. For professional service firms (PSFs, knowledge represents the input as well as the output, and thus the fundamental base for performance. As every organization, PSFs have to deal with errors – and how they do that indicates their error culture. Considering the positive potential of errors (e.g., innovation, error management culture is positively related to organizational performance. This longitudinal quantitative study investigates the impact of error management culture on knowledge performance in four waves. The study was conducted in 131 PSFs, i.e. tax accounting offices. As a standard quality management system (QMS was assumed to moderate the relationship between error management culture and knowledge performance, offices' ISO 9000 certification was assessed. Error management culture correlated positively with knowledge performance at a significant level and predicted knowledge performance one year later. While the ISO 9000 certification correlated positively with knowledge performance, its assumed moderation of the relationship between error management culture and knowledge performance was not consistent. The process-oriented QMS seems to function as facilitator for the more behavior-oriented error management culture. However, the benefit of ISO 9000 certification for tax accounting remains to be proven. Given the impact of error management culture on knowledge performance, PSFs should focus on actively promoting positive attitudes towards errors.

  1. Positioning Error Compensation of Linear Servo System Based on Genetic Algorithm and Neural Network%基于遗传神经网络的直线伺服系统定位误差补偿

    Institute of Scientific and Technical Information of China (English)

    林健; 汪木兰; 李宏胜

    2011-01-01

    针对数控直线伺服系统的定位误差补偿,采用激光干涉仪测量工作台的定位误差,建立基于RBF算法的神经网络误差模型.提出遗传算法的训练方案优化RBF的网络参数,为了评价优化后RBF网络预测的精度,运用部分误差样本进行训练和仿真.构建了以DSP为核心的直线电机定位误差实验平台,根据误差校正值进行误差实时补偿实验.仿真和实验结果表明:经过遗传算法训练的神经网络模型对工作台的误差具有良好的学习能力和泛化能力,工作台定位精度显著提高.%In view of the positioning error compensation of NC linear servo system, the positioning errors were measured by the laser interferometer, the neural network error model is set up by Radial Basis Function (RBF) algorithm.The training method of the genetic algorithm is also proposed to optimize the network parameters, in order to evaluate the accuracy of RBF network prediction method,part of the error samples are used to train and simulate.A DSP-core linear motor positioning error experimental platform was built, the error compensation experiments are conducted.The simulation and experimental results indicate that the RBF neural network error model trained by the genetic algorithm has a good learning ability and a generalization ability, the positioning accuracy is improved significantly.

  2. Rapid mapping of volumetric machine errors using distance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Krulewich, D.A.

    1998-04-01

    This paper describes a relatively inexpensive, fast, and easy to execute approach to maping the volumetric errors of a machine tool, coordinate measuring machine, or robot. An error map is used to characterize a machine or to improve its accuracy by compensating for the systematic errors. The method consists of three steps: (1) models the relationship between volumetric error and the current state of the machine, (2) acquiring error data based on distance measurements throughout the work volume; and (3)fitting the error model using the nonlinear equation for the distance. The error model is formulated from the kinematic relationship among the six degrees of freedom of error an each moving axis. Expressing each parametric error as function of position each is combined to predict the error between the functional point and workpiece, also as a function of position. A series of distances between several fixed base locations and various functional points in the work volume is measured using a Laser Ball Bar (LBB). Each measured distance is a non-linear function dependent on the commanded location of the machine, the machine error, and the location of the base locations. Using the error model, the non-linear equation is solved producing a fit for the error model Also note that, given approximate distances between each pair of base locations, the exact base locations in the machine coordinate system determined during the non-linear filling procedure. Furthermore, with the use of 2048 more than three base locations, bias error in the measuring instrument can be removed The volumetric errors of three-axis commercial machining center have been mapped using this procedure. In this study, only errors associated with the nominal position of the machine were considered Other errors such as thermally induced and load induced errors were not considered although the mathematical model has the ability to account for these errors. Due to the proprietary nature of the projects we are

  3. Experimental investigation of observation error in anuran call surveys

    Science.gov (United States)

    McClintock, B.T.; Bailey, L.L.; Pollock, K.H.; Simons, T.R.

    2010-01-01

    Occupancy models that account for imperfect detection are often used to monitor anuran and songbird species occurrence. However, presenceabsence data arising from auditory detections may be more prone to observation error (e.g., false-positive detections) than are sampling approaches utilizing physical captures or sightings of individuals. We conducted realistic, replicated field experiments using a remote broadcasting system to simulate simple anuran call surveys and to investigate potential factors affecting observation error in these studies. Distance, time, ambient noise, and observer abilities were the most important factors explaining false-negative detections. Distance and observer ability were the best overall predictors of false-positive errors, but ambient noise and competing species also affected error rates for some species. False-positive errors made up 5 of all positive detections, with individual observers exhibiting false-positive rates between 0.5 and 14. Previous research suggests false-positive errors of these magnitudes would induce substantial positive biases in standard estimators of species occurrence, and we recommend practices to mitigate for false positives when developing occupancy monitoring protocols that rely on auditory detections. These recommendations include additional observer training, limiting the number of target species, and establishing distance and ambient noise thresholds during surveys. ?? 2010 The Wildlife Society.

  4. The Errors Analysis and Correction in GPS Positioning Measuring%G PS 定位测量相关误差分析及修正

    Institute of Scientific and Technical Information of China (English)

    张珍云

    2015-01-01

    GPS测量技术以其卓越的性能已成功应用于诸多领域,对其测量精度的要求也越来越高。从GPS自身的测量精度、与卫星自身相关的误差、与信号传播途径相关的误差以及与接收设备相关的误差四个方面详细分析了测量过程中存在相关误差的原因,并相应地提出了避免或减小每种误差的方法。%T he measuring techniques of GPS have been successfully applied in many areas due to its ex‐cellent performance ,while the requirements of measurement accuracy also increase with each passing day .The paper makes an analysis of the errors in the measurement and its causes from four aspects , including the measuring accuracy of GPS ,the errors related to satellites ,the errors related to the ways of transforming signals and the errors related to the receiving equipments .Besides ,the approa‐ches to reduce or avoid each kind of errors are accordingly proposed .

  5. Target Uncertainty Mediates Sensorimotor Error Correction.

    Science.gov (United States)

    Acerbi, Luigi; Vijayakumar, Sethu; Wolpert, Daniel M

    2017-01-01

    Human movements are prone to errors that arise from inaccuracies in both our perceptual processing and execution of motor commands. We can reduce such errors by both improving our estimates of the state of the world and through online error correction of the ongoing action. Two prominent frameworks that explain how humans solve these problems are Bayesian estimation and stochastic optimal feedback control. Here we examine the interaction between estimation and control by asking if uncertainty in estimates affects how subjects correct for errors that may arise during the movement. Unbeknownst to participants, we randomly shifted the visual feedback of their finger position as they reached to indicate the center of mass of an object. Even though participants were given ample time to compensate for this perturbation, they only fully corrected for the induced error on trials with low uncertainty about center of mass, with correction only partial in trials involving more uncertainty. The analysis of subjects' scores revealed that participants corrected for errors just enough to avoid significant decrease in their overall scores, in agreement with the minimal intervention principle of optimal feedback control. We explain this behavior with a term in the loss function that accounts for the additional effort of adjusting one's response. By suggesting that subjects' decision uncertainty, as reflected in their posterior distribution, is a major factor in determining how their sensorimotor system responds to error, our findings support theoretical models in which the decision making and control processes are fully integrated.

  6. Target Uncertainty Mediates Sensorimotor Error Correction

    Science.gov (United States)

    Vijayakumar, Sethu; Wolpert, Daniel M.

    2017-01-01

    Human movements are prone to errors that arise from inaccuracies in both our perceptual processing and execution of motor commands. We can reduce such errors by both improving our estimates of the state of the world and through online error correction of the ongoing action. Two prominent frameworks that explain how humans solve these problems are Bayesian estimation and stochastic optimal feedback control. Here we examine the interaction between estimation and control by asking if uncertainty in estimates affects how subjects correct for errors that may arise during the movement. Unbeknownst to participants, we randomly shifted the visual feedback of their finger position as they reached to indicate the center of mass of an object. Even though participants were given ample time to compensate for this perturbation, they only fully corrected for the induced error on trials with low uncertainty about center of mass, with correction only partial in trials involving more uncertainty. The analysis of subjects’ scores revealed that participants corrected for errors just enough to avoid significant decrease in their overall scores, in agreement with the minimal intervention principle of optimal feedback control. We explain this behavior with a term in the loss function that accounts for the additional effort of adjusting one’s response. By suggesting that subjects’ decision uncertainty, as reflected in their posterior distribution, is a major factor in determining how their sensorimotor system responds to error, our findings support theoretical models in which the decision making and control processes are fully integrated. PMID:28129323

  7. Effect of atmospheric turbulence on the bit error probability of a space to ground near infrared laser communications link using binary pulse position modulation and an avalanche photodiode detector

    Science.gov (United States)

    Safren, H. G.

    1987-01-01

    The effect of atmospheric turbulence on the bit error rate of a space-to-ground near infrared laser communications link is investigated, for a link using binary pulse position modulation and an avalanche photodiode detector. Formulas are presented for the mean and variance of the bit error rate as a function of signal strength. Because these formulas require numerical integration, they are of limited practical use. Approximate formulas are derived which are easy to compute and sufficiently accurate for system feasibility studies, as shown by numerical comparison with the exact formulas. A very simple formula is derived for the bit error rate as a function of signal strength, which requires only the evaluation of an error function. It is shown by numerical calculations that, for realistic values of the system parameters, the increase in the bit error rate due to turbulence does not exceed about thirty percent for signal strengths of four hundred photons per bit or less. The increase in signal strength required to maintain an error rate of one in 10 million is about one or two tenths of a db.

  8. Process Accounting

    OpenAIRE

    Gilbertson, Keith

    2002-01-01

    Standard utilities can help you collect and interpret your Linux system's process accounting data. Describes the uses of process accounting, standard process accounting commands, and example code that makes use of process accounting utilities.

  9. Effects of spine tracking parameters on the positioning errors of cyberknife%脊柱追踪相关参数对射波刀定位误差影响

    Institute of Scientific and Technical Information of China (English)

    赵瑞; 王震岳; 李莎; 陆军

    2016-01-01

    Objective To investigate the effects of spine region of interest (ROI),tracking range,and real-time image contrast ratio on the positioning errors of cyberknife.Methods The LTT dynamic phantom was used to develop a spine tracking plan and perform treatment,and the target positioning system was used to preset the phantom and obtain real-time preset image and positioning error.Based on the realtime preset image,spine ROI,tracking range,and real-time image contrast ratio were changed to observe the changes in positioning error and related parameters.Pearson correlation analysis was performed.Results The change in tracking range did not change the positioning error in spine tracking,and tracking range was not correlated with positioning error (R =0,P =1).The changes in ROI and image contrast ratio did not affect the translation error,but affected the rotation error,especially the rotation error in left-right direction (r =0.533 and 0.693,P=0.002 and 0.026).The image contrast ratio had the most obvious effect,with an amplitude of variation up to 2.2°.Conclusions The change in tracking range does not affect the positioning errors in spinal tracking,but the changes in ROI and image contrast ratio can cause varying degrees of changes in positioning errors,which should be taken seriously in cyberknife treatment.%目的 探讨脊柱ROI、追踪范围和实时影像对比度系数与射波刀定位误差的关系.方法 利用肺追踪体模制定脊柱追踪计划并进行治疗,通过目标定位系统进行体模预置,获得体模实时预置影像及定位误差;以实时预置影像为基础,改体模脊柱ROI大小、追踪范围和实时影像对比度系数,观察体模定位误差及相关参数的改变.采用Pearson法相关分析.结果 追踪范围的改变不会引起脊柱追踪定位误差的改变,追踪范围与脊柱追踪定位误差无关联(R=0,P=1);ROI大小和影像对比度系数的改变对脊柱追踪平移误差无影响,但对脊柱追踪旋

  10. Error bounds for set inclusions

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Xiyin(郑喜印)

    2003-01-01

    A variant of Robinson-Ursescu Theorem is given in normed spaces. Several error bound theorems for convex inclusions are proved and in particular a positive answer to Li and Singer's conjecture is given under weaker assumption than the assumption required in their conjecture. Perturbation error bounds are also studied. As applications, we study error bounds for convex inequality systems.

  11. Feature Referenced Error Correction Apparatus.

    Science.gov (United States)

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

  12. 复杂系统误差传递的主次作用分析与控制%The primary and secondary position analysis and control of error propagating for a complex system

    Institute of Scientific and Technical Information of China (English)

    唐冰松; 王增会

    2013-01-01

    系统观测目标误差渗透着系统误差和随机误差,系统误差和随机误差的分离与溯源理论和应用一直是误差分析的难点和热点。文中基于系统误差和随机误差的互相关系与传递特征,提出了以传递函数为基础的误差传递模型,并基于该模型,将复杂系统划分为若干个子系统,分析了各子系统在观测目标误差中的主次作用( primary and secondary position a-nalysis,PSPA)。算例表明,该理论能够分析得出引起观测误差灵敏度较高的子系统,这对于误差溯源、分析和控制误差,提高观测目标的精度具有一定的指导意义。%System error and random error are usually included in the error of target parameter .The theory and application about the separation and tracing for both are always the hot and difficult topic in research .An error propagating model based on propagating function is proposed .The primary and secondary position analysis ( PS-PA) of the subsystem error propagating in the complex system is based on this model , while the whole complex system can be divided into several subsystems .An example shows that this model can analyze and determine the relative crucial subsystem in error tracing .There may be significant inspiration in how to find the origin of error and how to analyze and control the error .The most important is that the model proposed above provides a path for improving the accuracy of the target parameter .

  13. The Pupillary Orienting Response Predicts Adaptive Behavioral Adjustment after Errors.

    Directory of Open Access Journals (Sweden)

    Peter R Murphy

    Full Text Available Reaction time (RT is commonly observed to slow down after an error. This post-error slowing (PES has been thought to arise from the strategic adoption of a more cautious response mode following deployment of cognitive control. Recently, an alternative account has suggested that PES results from interference due to an error-evoked orienting response. We investigated whether error-related orienting may in fact be a pre-cursor to adaptive post-error behavioral adjustment when the orienting response resolves before subsequent trial onset. We measured pupil dilation, a prototypical measure of autonomic orienting, during performance of a choice RT task with long inter-stimulus intervals, and found that the trial-by-trial magnitude of the error-evoked pupil response positively predicted both PES magnitude and the likelihood that the following response would be correct. These combined findings suggest that the magnitude of the error-related orienting response predicts an adaptive change of response strategy following errors, and thereby promote a reconciliation of the orienting and adaptive control accounts of PES.

  14. 基于平方位置误差下限的优化功率分配方案%OPTIMISED POWER ALLOCATION ALGORITHM BASED ON SQUARE POSITION LOWER ERROR BOUND

    Institute of Scientific and Technical Information of China (English)

    李秉键; 夏文栋; 郭其标; 任江涛

    2015-01-01

    在无线传感网络中,节点定位是基于位置的应用基本要求。然而,现多数文献仅关注定位精度,而忽略了能量消耗对定位精度的影响。为此,针对基于接收信号强度 RSSI(Received Signal Strength Indicator)定位方案,提出基于平方位置误差下限 SPEB (Squared Position Error Bound)的优化功率分配 SPEB-OPA(SPEB-Based Optimal Power Allocation)方案,目的在于最小化能量消耗。在 SPEB-OPA 算法中,将 SPEB 作为评定定位精度的参数,并推导出 SPEB 表达式,然后建立优化功率分配的目标函数,并考虑到锚节点位置存在误差。仿真结果表明,提出的 SPEB-OPA 方案极大地减少了功率消耗。当误差门限 T =8时,SPEB-OPA 方案的功率消耗比统一功率分配 UPA(Uniform Power allocation)方案减少至50%。%Sensor nodes positioning is a fundamental requirement of location-based applications in wireless sensor networks.However,now most of the literatures only focus on positioning accuracy,but the impact of energy consumption on positioning accuracy is overlooked.There-fore,for RSSI-based positioning scheme,we introduced an optimised power allocation scheme which is based on square position lower error bound (SPEB-OPA),aimed at minimising the energy consumption.In SPEB-OPA algorithm,we used SPEB as the parameter for estimating positioning accuracy,and deduced the SPEB expression.Then we set up the objective function of the optimised power allocation,and consid-ered the errors existed in positions of anchor nodes.Simulation results showed that the proposed SPEB-OPA scheme greatly decreased the power consumption.When the error threshold T =8,the power consumption of SPEB-OPA scheme was reduced to 50% of that of uniform power allocation (UPA)scheme.

  15. Internet Accounting

    NARCIS (Netherlands)

    Pras, Aiko; Beijnum, van Bert-Jan; Sprenkels, Ron; Párhonyi, Robert

    2001-01-01

    This article provides an introduction to Internet accounting and discusses the status of related work within the IETF and IRTF, as well as certain research projects. Internet accounting is different from accounting in POTS. To understand Internet accounting, it is important to answer questions like

  16. Accounting Automation

    OpenAIRE

    Laynebaril1

    2017-01-01

    Accounting Automation   Click Link Below To Buy:   http://hwcampus.com/shop/accounting-automation/  Or Visit www.hwcampus.com Accounting Automation” Please respond to the following: Imagine you are a consultant hired to convert a manual accounting system to an automated system. Suggest the key advantages and disadvantages of automating a manual accounting system. Identify the most important step in the conversion process. Provide a rationale for your response. ...

  17. 8-position calibrating method for system error of digital magnetometer%一种八位置数字磁强计系统误差标定方法

    Institute of Scientific and Technical Information of China (English)

    林恒; 魏莹莹; 李保国

    2011-01-01

    Among the factors affecting the system error of digital magnetometer, the contributor comes from the precision variance of the production of the digital magnetometer and installation. Through a careful analysis and calculation of system error of digital magnetometer,a simple and effective method for system error compensation is presented which is the 8-position calibrating method. Experiments are done to verify the method. The result shows that the system error of digital magnetometer can be compensated and the heading measure precision can be improved validly by using this method.%由于数字磁强计本身制作和生产安装的精度差异,产生了数字磁强计的系统误差.通过对数字磁强计的系统误差进行详细分析和理论计算,建立了误差方程,并提出了一种简单有效的系统误差补偿方法--八位置标定方法,并对此方法进行了实验验证.实验结果表明:该方法可以较好地补偿数字磁强计的系统误差,提高航向测量精度.

  18. Errors and mistakes in breast ultrasound diagnostics.

    Science.gov (United States)

    Jakubowski, Wiesław; Dobruch-Sobczak, Katarzyna; Migda, Bartosz

    2012-09-01

    Sonomammography is often the first additional examination performed in the diagnostics of breast diseases. The development of ultrasound imaging techniques, particularly the introduction of high frequency transducers, matrix transducers, harmonic imaging and finally, elastography, influenced the improvement of breast disease diagnostics. Nevertheless, as in each imaging method, there are errors and mistakes resulting from the technical limitations of the method, breast anatomy (fibrous remodeling), insufficient sensitivity and, in particular, specificity. Errors in breast ultrasound diagnostics can be divided into impossible to be avoided and potentially possible to be reduced. In this article the most frequently made errors in ultrasound have been presented, including the ones caused by the presence of artifacts resulting from volumetric averaging in the near and far field, artifacts in cysts or in dilated lactiferous ducts (reverberations, comet tail artifacts, lateral beam artifacts), improper setting of general enhancement or time gain curve or range. Errors dependent on the examiner, resulting in the wrong BIRADS-usg classification, are divided into negative and positive errors. The sources of these errors have been listed. The methods of minimization of the number of errors made have been discussed, including the ones related to the appropriate examination technique, taking into account data from case history and the use of the greatest possible number of additional options such as: harmonic imaging, color and power Doppler and elastography. In the article examples of errors resulting from the technical conditions of the method have been presented, and those dependent on the examiner which are related to the great diversity and variation of ultrasound images of pathological breast lesions.

  19. Errors and mistakes in breast ultrasound diagnostics

    Science.gov (United States)

    Jakubowski, Wiesław; Migda, Bartosz

    2012-01-01

    Sonomammography is often the first additional examination performed in the diagnostics of breast diseases. The development of ultrasound imaging techniques, particularly the introduction of high frequency transducers, matrix transducers, harmonic imaging and finally, elastography, influenced the improvement of breast disease diagnostics. Nevertheless, as in each imaging method, there are errors and mistakes resulting from the technical limitations of the method, breast anatomy (fibrous remodeling), insufficient sensitivity and, in particular, specificity. Errors in breast ultrasound diagnostics can be divided into impossible to be avoided and potentially possible to be reduced. In this article the most frequently made errors in ultrasound have been presented, including the ones caused by the presence of artifacts resulting from volumetric averaging in the near and far field, artifacts in cysts or in dilated lactiferous ducts (reverberations, comet tail artifacts, lateral beam artifacts), improper setting of general enhancement or time gain curve or range. Errors dependent on the examiner, resulting in the wrong BIRADS-usg classification, are divided into negative and positive errors. The sources of these errors have been listed. The methods of minimization of the number of errors made have been discussed, including the ones related to the appropriate examination technique, taking into account data from case history and the use of the greatest possible number of additional options such as: harmonic imaging, color and power Doppler and elastography. In the article examples of errors resulting from the technical conditions of the method have been presented, and those dependent on the examiner which are related to the great diversity and variation of ultrasound images of pathological breast lesions. PMID:26675358

  20. Errors and mistakes in breast ultrasound diagnostics

    Directory of Open Access Journals (Sweden)

    Wiesław Jakubowski

    2012-09-01

    Full Text Available Sonomammography is often the first additional examination performed in the diagnostics of breast diseases. The development of ultrasound imaging techniques, particularly the introduction of high frequency transducers, matrix transducers, harmonic imaging and finally, elastography, influenced the improvement of breast disease diagnostics. Neverthe‑ less, as in each imaging method, there are errors and mistakes resulting from the techni‑ cal limitations of the method, breast anatomy (fibrous remodeling, insufficient sensitivity and, in particular, specificity. Errors in breast ultrasound diagnostics can be divided into impossible to be avoided and potentially possible to be reduced. In this article the most frequently made errors in ultrasound have been presented, including the ones caused by the presence of artifacts resulting from volumetric averaging in the near and far field, artifacts in cysts or in dilated lactiferous ducts (reverberations, comet tail artifacts, lateral beam artifacts, improper setting of general enhancement or time gain curve or range. Errors dependent on the examiner, resulting in the wrong BIRADS‑usg classification, are divided into negative and positive errors. The sources of these errors have been listed. The methods of minimization of the number of errors made have been discussed, includ‑ ing the ones related to the appropriate examination technique, taking into account data from case history and the use of the greatest possible number of additional options such as: harmonic imaging, color and power Doppler and elastography. In the article examples of errors resulting from the technical conditions of the method have been presented, and those dependent on the examiner which are related to the great diversity and variation of ultrasound images of pathological breast lesions.

  1. Determination of locational error associated with global positioning system (GPS) radio collars in relation to vegetation and topography in north-central New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, K.; Biggs, J.; Fresquez, P.R.

    1997-02-01

    In 1996, a study was initiated to assess seasonal habitat use and movement patterns of Rocky Mountain elk (Cervus elaphus nelsoni) using global positioning system (GPS) radio collars. As part of this study, the authors attempted to assess the accuracies of GPS (non-differentially corrected) positions under various vegetation canopies and terrain conditions with the use of a GPS ``test`` collar. The test collar was activated every twenty minutes to obtain a position location and continuously uplinked to Argos satellites to transfer position data files. They used a Telonics, Inc. uplink receiver to intercept the transmission and view the results of the collar in real time. They placed the collar on a stand equivalent to the neck height of an adult elk and then placed the stand within three different treatment categories: (1) topographical influence (canyon and mesa tops), (2) canopy influence (open and closed canopy), and (3) vegetation type influence (ponderosa pine and pinion pine-juniper). The collar was kept at each location for one hour (usually obtaining three fixes). In addition, the authors used a hand-held GPS to obtain a position of the test collar at the same time and location.

  2. Errors in Radiologic Reporting

    Directory of Open Access Journals (Sweden)

    Esmaeel Shokrollahi

    2010-05-01

    Full Text Available Given that the report is a professional document and bears the associated responsibilities, all of the radiologist's errors appear in it, either directly or indirectly. It is not easy to distinguish and classify the mistakes made when a report is prepared, because in most cases the errors are complex and attributable to more than one cause and because many errors depend on the individual radiologists' professional, behavioral and psychological traits."nIn fact, anyone can make a mistake, but some radiologists make more mistakes, and some types of mistakes are predictable to some extent."nReporting errors can be categorized differently:"nUniversal vs. individual"nHuman related vs. system related"nPerceptive vs. cognitive errors"n1. Descriptive "n2. Interpretative "n3. Decision related Perceptive errors"n1. False positive "n2. False negative"n Nonidentification "n Erroneous identification "nCognitive errors "n Knowledge-based"n Psychological  

  3. Refractive Errors

    Science.gov (United States)

    ... does the eye focus light? In order to see clearly, light rays from an object must focus onto the ... The refractive errors are: myopia, hyperopia and astigmatism [See figures 2 and 3]. What is hyperopia (farsightedness)? Hyperopia occurs when light rays focus behind the retina (because the eye ...

  4. Medication Errors

    Science.gov (United States)

    ... Proprietary Names (PDF - 146KB) Draft Guidance for Industry: Best Practices in Developing Proprietary Names for Drugs (PDF - 279KB) ... or (301) 796-3400 druginfo@fda.hhs.gov Human Drug ... in Medication Errors Resources for You Agency for Healthcare Research and Quality: ...

  5. Translational and rotational intra- and inter-fractional errors in patient and target position during a short course of frameless stereotactic body radiotherapy

    DEFF Research Database (Denmark)

    Josipovic, Mirjana; Persson, Gitte Fredberg; Logadottir, Ashildur;

    2012-01-01

    Implementation of cone beam computed tomography (CBCT) in frameless stereotactic body radiotherapy (SBRT) of lung tumours enables setup correction based on tumour position. The aim of this study was to compare setup accuracy with daily soft tissue matching to bony anatomy matching and evaluate...

  6. Sensitivity of CIPS-computed PVC location to measurement errors in ECG electrode position: the need for the 3D Camera

    NARCIS (Netherlands)

    Dam, P.M. van; Gordon, J.P.; Laks, M.

    2014-01-01

    BACKGROUND: The Cardiac Isochrone Positioning System (CIPS) is a non-invasive method able to localize the origins of PVCs, VT and WPW from the 12 lead ECG. The CIPS model integrates a standard 12-lead ECG with an MRI derived model of the heart, lungs, and torso in order to compute the precise electr

  7. Wi-Fi access Point Placement Optimization for Lowest Positioning Error Bound%最小定位误差限的Wi-Fi接入点优化布置

    Institute of Scientific and Technical Information of China (English)

    周牧; 邱枫; 田增山; 史瑞康; 范馨月

    2015-01-01

    提出了一种基于最小定位误差限的Wi-Fi指纹定位接入点位置优化方法.利用费歇尔信息矩阵的特性,分析了定位误差与不同信号强度分布的数学关系.首先,根据信号强度分布特性的不同,将定位目标区域划分为若干子区域;然后,推导出定位目标区域所对应的平均定位误差限;最后,利用模拟退火算法搜索最优接入点位置使得平均定位误差限达到最小. 仿真结果表明,此方法可以有效提高Wi-Fi位置指纹定位法的精度.%A new access point placement optimization approach based on lowest positioning error bound in Wi-Fi fingerprint based localization was proposed. Analysis towards the theoretical relationship between positioning error and various signal distributions by using Fisher information matrix was presented. The target environment was divided into several subareas based on signal distributions. And then, the average error bound corresponding to the target environment was derived out. Thirdly, the heuristic simulated an-nealing algorithm towards the lowest average error bound to optimize access point locations was adopted. Simulation demonstrates that the proposed access point placement optimization approach effectively im-proves the precision of Wi-Fi fingerprint based localization.

  8. Educational Accountability

    Science.gov (United States)

    Pincoffs, Edmund L.

    1973-01-01

    Discusses educational accountability as the paradigm of performance contracting, presents some arguments for and against accountability, and discusses the goals of education and the responsibility of the teacher. (Author/PG)

  9. Accounting outsourcing

    OpenAIRE

    Richtáriková, Paulína

    2012-01-01

    The thesis deals with accounting outsourcing and provides a comprehensive explanation of the topic. At first the thesis defines basic concepts (outsourcing, insourcing, offshoring and outplacement) and describes differences between the accounting outsourcing and outsourcing of other business activities. The emphasis is put on a decision whether or not to implement the accounting outsourcing. Thus the thesis describes main reasons why to implement the accounting outsourcing and risks that are ...

  10. Accounting outsourcing

    OpenAIRE

    Klečacká, Tereza

    2009-01-01

    This thesis gives a complex view on accounting outsourcing, deals with the outsourcing process from its beginning (condition of collaboration, making of contract), through collaboration to its possible ending. This work defines outsourcing, indicates the main advatages, disadvatages and arguments for its using. The main object of thesis is mainly practical side of accounting outsourcing and providing of first quality accounting services.

  11. Accounting standards

    NARCIS (Netherlands)

    Stellinga, B.; Mügge, D.

    2014-01-01

    The European and global regulation of accounting standards have witnessed remarkable changes over the past twenty years. In the early 1990s, EU accounting practices were fragmented along national lines and US accounting standards were the de facto global standards. Since 2005, all EU listed companie

  12. Research on optical interference error in cantilever's positioning system of AFM and its reduction methods%AFM悬臂定位系统中光干涉误差及减小方法研究

    Institute of Scientific and Technical Information of China (English)

    黄强先; 万耿华; 谢鸿; 权太聪; 三隅伊知子; 金泰皓; 黑泽富藏

    2007-01-01

    Optical lever method is a main technique to detect the cantilevers position in atomic force microscope (AFM). Due to the limitations of cantilevers dimensions, characteristics of cantilever material and detecting optical system, the leakage of detecting light exists in the cantilevers positioning system. Some leaked light scattered by sample surface interferences with the light reflected by the cantilever. Therefore, an optical interference error occurs in the probe-sample approaching curve. Based on the tapping mode AFM, the factors causing the optical interference error are analyzed;the AFM measurement errors caused by the optical interference are deduced mathematically and simulated;several methods are put forwards to reduce the error. Experimental results and theoretical analysis show that in order to improve the measurement accuracy of AFM, it is necessary to overcome the optical interference error in the cantilevers positioning system.%光杠杆法是原子力显微镜(AFM)悬臂定位的主要方法.由于悬臂自身的尺寸和材料特性、检测光路系统等因素制约,悬臂弯曲测量时存在光泄露.被试样表面反射的部分泄露光与悬臂反射光产生干涉,在探针-试样接近曲线中产生光干涉误差.基于轻触模式AFM,分析了光干涉误差的产生原因,并对其引起的AFM测量误差进行了数学分析和仿真、提出了减小光干涉误差的方法.实验结果和理论分析表明,为了进一步提高AFM的测量精度,有必要克服定位系统中的光干涉误差.

  13. Measurement Error Models in Astronomy

    CERN Document Server

    Kelly, Brandon C

    2011-01-01

    I discuss the effects of measurement error on regression and density estimation. I review the statistical methods that have been developed to correct for measurement error that are most popular in astronomical data analysis, discussing their advantages and disadvantages. I describe functional models for accounting for measurement error in regression, with emphasis on the methods of moments approach and the modified loss function approach. I then describe structural models for accounting for measurement error in regression and density estimation, with emphasis on maximum-likelihood and Bayesian methods. As an example of a Bayesian application, I analyze an astronomical data set subject to large measurement errors and a non-linear dependence between the response and covariate. I conclude with some directions for future research.

  14. Elimination of Abbe error method of large-scale laser comparator

    Science.gov (United States)

    Li, Jianshuang; Zhang, Manshan; He, Mingzhao; Miao, Dongjing; Deng, Xiangrui; Li, Lianfu

    2015-02-01

    Abbe error is the inherent systematic error in all large-scale laser comparators because the standard laser axis is not in line with measured optical axis. Any angular error of the moving platform will result in the offset from the measured optical axis to the standard laser axis. This paper describes to an algorithm which could be used to calculate the displacement of an equivalent standard laser interferometer and to eliminate an Abbe error. The algorithm could also be used to reduce the Abbe error of a large-scale laser comparator. Experimental results indicated that the uncertainty of displacement measurement due to Abbe error could be effectively reduced when the position error of the measured optical axis was taken into account.

  15. COMPUTER-ASSISTED ACCOUNTING

    Directory of Open Access Journals (Sweden)

    SORIN-CIPRIAN TEIUŞAN

    2009-01-01

    Full Text Available What is computer-assisted accounting? Where is the place and what is the role of the computer in the financial-accounting activity? What is the position and importance of the computer in the accountant’s activity? All these are questions that require scientific research in order to find the answers. The paper approaches the issue of the support granted to the accountant to organize and manage the accounting activity by the computer. Starting from the notions of accounting and computer, the concept of computer-assisted accounting is introduced, it has a general character and it refers to the accounting performed with the help of the computer or using the computer to automate the procedures performed by the person who is doing the accounting activity; this is a concept used to define the computer applications of the accounting activity. The arguments regarding the use of the computer to assist accounting targets the accounting informatization, the automating of the financial-accounting activities and the endowment with modern technology of the contemporary accounting.

  16. False-positive myeloperoxidase binding activity due to DNA/anti-DNA antibody complexes: a source for analytical error in serologic evaluation of anti-neutrophil cytoplasmic autoantibodies.

    Science.gov (United States)

    Jethwa, H S; Nachman, P H; Falk, R J; Jennette, J C

    2000-09-01

    Anti-myeloperoxidase antibodies (anti-MPO) are a major type of anti-neutrophil cytoplasmic antibody (ANCA). While evaluating anti-MPO monoclonal antibodies from SCG/Kj mice, we observed several hybridomas that appeared to react with both MPO and DNA. Sera from some patients with systemic lupus erythematosus (SLE) also react with MPO and DNA. We hypothesized that the MPO binding activity is a false-positive result due to the binding of DNA, contained within the antigen binding site of anti-DNA antibodies, to the cationic MPO. Antibodies from tissue culture supernatants from 'dual reactive' hybridomas were purified under high-salt conditions (3 M NaCl) to remove any antigen bound to antibody. The MPO and DNA binding activity were measured by ELISA. The MPO binding activity was completely abrogated while the DNA binding activity remained. The MPO binding activity was restored, in a dose-dependent manner, by the addition of increasing amount of calf-thymus DNA (CT-DNA) to the purified antibody. Sera from six patients with SLE that reacted with both MPO and DNA were treated with DNase and showed a decrease in MPO binding activity compared with untreated samples. MPO binding activity was observed when CT-DNA was added to sera from SLE patients that initially reacted with DNA but not with MPO. These results suggest that the DNA contained within the antigen binding site of anti-DNA antibodies could bind to the highly cationic MPO used as substrate antigen in immunoassays, resulting in a false-positive test.

  17. Multi-scenario based robust intensity-modulated proton therapy (IMPT) plans can account for set-up errors more effectively in terms of normal tissue sparing than planning target volume (PTV) based intensity-modulated photon plans in the head and neck region.

    Science.gov (United States)

    Stuschke, Martin; Kaiser, Andreas; Abu Jawad, Jehad; Pöttgen, Christoph; Levegrün, Sabine; Farr, Jonathan

    2013-06-18

    In a previous report, we compared the conformity of robust intensity-modulated proton therapy (IMPT) plans with that of helical tomotherapy plans for re-irradiations of head and neck carcinomas using a fixed set-up error of 2 mm. Here, we varied the maximum set-up errors between 0 and 5 mm and compared the robust IMPT-plans with planning target volume (PTV) based intensity-modulated photon therapy (IMRT). Seven patients were treated with a PTV-based tomotherapy plan. Set-up margins of 0, 2, and 5 mm were subtracted from the PTV to generate target volumes (TV) TV(0mm), TV(2mm), and TV(5mm), for which robust IMPT-plans were created assuming range uncertainties of ±3.5% and using worst case optimization assuming set-up errors of 0, 2, and 5 mm, respectively. Robust optimization makes use of the feature that set-up errors in beam direction alone do not affect the distal and proximal margin for that beam. With increasing set-up errors, the body volumes that were exposed to a selected minimum dose level between 20% and 95% of the prescribed dose decreased. In IMPT-plans with 0 mm set-up error, the exposed body volumes were on average 6.2% ± 0.9% larger than for IMPT-plans with 2 mm set-up error, independent of the considered dose level (p plans accounting for 5 mm set-up error, the exposed body volumes were by 11.9% ± 0.8% smaller than for IMPT-plans with 2 mm set-up error at a fixed minimum dose (p plans corresponding to the same IMRT-plan led to a decrease in the mean dose to the temporal lobes and the cerebellum, and in the D2% of the brain stem or spinal cord with increasing set-up errors considered during robust IMPT-planning. For recurrent head and neck cancer, robust IMPT-plan optimization led to a decrease in normal tissue exposure with increasing set-up error for target volumes corresponding to the same PTV.

  18. Acceptance and Efficacy of Metacognitive Training (MCT) on Positive Symptoms and Delusions in Patients With Schizophrenia: A Meta-analysis Taking Into Account Important Moderators.

    Science.gov (United States)

    Eichner, Carolin; Berna, Fabrice

    2016-07-01

    Metacognitive training (MCT) is a new, widely used intervention for psychosis. The present meta-analysis examines the efficacy of MCT in schizophrenia. Fifteen studies comparing effects of MCT on positive symptoms, delusions or acceptance of MCT with a control group were included in this meta-analysis. These studies comprised a total of 408 patients in the MCT condition and 399 in the control condition. The moderating effects of masking of outcome assessment, randomization, incomplete outcome data, use of an active control intervention, and individual vs group MCT were investigated. Possible effects of sensitivity analyses and publication bias were also examined. The results show a significant overall effect of MCT for positive symptoms (g = -0.34, 95% CI [-0.53, -0.15]), delusions (g = -0.41, 95% CI [-0.74, -0.07]) and acceptance of the intervention (g = -0.84, 95% CI [-1.37, -0.31]). Using only studies being at low risk for bias regarding randomization, masking and incomplete outcome data reduced effect sizes for positive symptoms and delusions (g = -0.28, 95% CI [-0.50, -0.06] and g = -0.18, 95% CI [-0.43, 0.06]), respectively. This meta-analysis demonstrates that MCT exerts a small to moderate effect on delusions and positive symptoms and a large effect on acceptance of the intervention. The effect on delusions is reduced, but remains significant when potential biases are considered.

  19. Motion Detection, Letter Position Encoding, and Single Word Reading.

    Science.gov (United States)

    Cornelissen, P. L.; Hansen, P. C.

    1998-01-01

    A study involving 48 undergraduates found a link between motion detection and letter-position encoding and a positive relationship, albeit a nonlinear one, between motion detection threshold and the likelihood of making letter errors. This result held when age, IQ, reading age, and phonological awareness were taken into account. (CR)

  20. Accounting for Life-Course Exposures in Epigenetic Biomarker Association Studies: Early Life Socioeconomic Position, Candidate Gene DNA Methylation, and Adult Cardiometabolic Risk.

    Science.gov (United States)

    Huang, Jonathan Y; Gavin, Amelia R; Richardson, Thomas S; Rowhani-Rahbar, Ali; Siscovick, David S; Hochner, Hagit; Friedlander, Yechiel; Enquobahrie, Daniel A

    2016-10-01

    Recent studies suggest that epigenetic programming may mediate the relationship between early life environment, including parental socioeconomic position, and adult cardiometabolic health. However, interpreting associations between early environment and adult DNA methylation may be difficult because of time-dependent confounding by life-course exposures. Among 613 adult women (mean age = 32 years) of the Jerusalem Perinatal Study Family Follow-up (2007-2009), we investigated associations between early life socioeconomic position (paternal occupation and parental education) and mean adult DNA methylation at 5 frequently studied cardiometabolic and stress-response genes (ABCA1, INS-IGF2, LEP, HSD11B2, and NR3C1). We used multivariable linear regression and marginal structural models to estimate associations under 2 causal structures for life-course exposures and timing of methylation measurement. We also examined whether methylation was associated with adult cardiometabolic phenotype. Higher maternal education was consistently associated with higher HSD11B2 methylation (e.g., 0.5%-point higher in 9-12 years vs. ≤8 years, 95% confidence interval: 0.1, 0.8). Higher HSD11B2 methylation was also associated with lower adult weight and total and low-density lipoprotein cholesterol. We found that associations with early life socioeconomic position measures were insensitive to different causal assumption; however, exploratory analysis did not find evidence for a mediating role of methylation in socioeconomic position-cardiometabolic risk associations. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Human Error Mechanisms in Complex Work Environments

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1988-01-01

    will account for most of the action errors observed. In addition, error mechanisms appear to be intimately related to the development of high skill and know-how in a complex work context. This relationship between errors and human adaptation is discussed in detail for individuals and organisations...

  2. Quantifying error distributions in crowding.

    Science.gov (United States)

    Hanus, Deborah; Vul, Edward

    2013-03-22

    When multiple objects are in close proximity, observers have difficulty identifying them individually. Two classes of theories aim to account for this crowding phenomenon: spatial pooling and spatial substitution. Variations of these accounts predict different patterns of errors in crowded displays. Here we aim to characterize the kinds of errors that people make during crowding by comparing a number of error models across three experiments in which we manipulate flanker spacing, display eccentricity, and precueing duration. We find that both spatial intrusions and individual letter confusions play a considerable role in errors. Moreover, we find no evidence that a naïve pooling model that predicts errors based on a nonadditive combination of target and flankers explains errors better than an independent intrusion model (indeed, in our data, an independent intrusion model is slightly, but significantly, better). Finally, we find that manipulating trial difficulty in any way (spacing, eccentricity, or precueing) produces homogenous changes in error distributions. Together, these results provide quantitative baselines for predictive models of crowding errors, suggest that pooling and spatial substitution models are difficult to tease apart, and imply that manipulations of crowding all influence a common mechanism that impacts subject performance.

  3. Medication Errors - A Review

    OpenAIRE

    Vinay BC; Nikhitha MK; Patel Sunil B

    2015-01-01

    In this present review article, regarding medication errors its definition, medication error problem, types of medication errors, common causes of medication errors, monitoring medication errors, consequences of medication errors, prevention of medication error and managing medication errors have been explained neatly and legibly with proper tables which is easy to understand.

  4. Medication Errors - A Review

    OpenAIRE

    Vinay BC; Nikhitha MK; Patel Sunil B

    2015-01-01

    In this present review article, regarding medication errors its definition, medication error problem, types of medication errors, common causes of medication errors, monitoring medication errors, consequences of medication errors, prevention of medication error and managing medication errors have been explained neatly and legibly with proper tables which is easy to understand.

  5. Accounting assessment

    Directory of Open Access Journals (Sweden)

    Kafka S.М.

    2017-03-01

    Full Text Available The proper evaluation of accounting objects influences essentially upon the reliability of assessing the financial situation of a company. Thus, the problem in accounting estimate is quite relevant. The works of home and foreign scholars on the issues of assessment of accounting objects, regulatory and legal acts of Ukraine controlling the accounting and compiling financial reporting are a methodological basis for the research. The author uses the theoretical methods of cognition (abstraction and generalization, analysis and synthesis, induction and deduction and other methods producing conceptual knowledge for the synthesis of theoretical and methodological principles in the evaluation of assets accounting, liabilities and equity. The tabular presentation and information comparison methods are used for analytical researches. The article considers the modern approaches to the issue of evaluation of accounting objects and financial statements items. The expedience to keep records under historical value is proved and the articles of financial statements are to be presented according to the evaluation on the reporting date. In connection with the evaluation the depreciation of fixed assets is considered as a process of systematic return into circulation of the before advanced funds on the purchase (production, improvement of fixed assets and intangible assets by means of including the amount of wear in production costs. Therefore it is proposed to amortize only the actual costs incurred, i.e. not to depreciate the fixed assets received free of charge and surplus valuation of different kinds.

  6. Preferential binding of positive nanoparticles on cell membranes is due to electrostatic interactions: A too simplistic explanation that does not take into account the nanoparticle protein corona.

    Science.gov (United States)

    Forest, Valérie; Pourchez, Jérémie

    2017-01-01

    The internalization of nanoparticles by cells (and more broadly the nanoparticle/cell interaction) is a crucial issue both for biomedical applications (for the design of nanocarriers with enhanced cellular uptake to reach their intracellular therapeutic targets) and in a nanosafety context (as the internalized dose is one of the key factors in cytotoxicity). Many parameters can influence the nanoparticle/cell interaction, among them, the nanoparticle physico-chemical features, and especially the surface charge. It is generally admitted that positive nanoparticles are more uptaken by cells than neutral or negative nanoparticles. It is supposedly due to favorable electrostatic interactions with negatively charged cell membrane. However, this theory seems too simplistic as it does not consider a fundamental element: the nanoparticle protein corona. Indeed, once introduced in a biological medium nanoparticles adsorb proteins at their surface, forming a new interface defining the nanoparticle "biological identity". This adds a new level of complexity in the interactions with biological systems that cannot be any more limited to electrostatic binding. These interactions will then influence cell behavior. Based on a literature review and on an example of our own experience the parameters involved in the nanoparticle protein corona formation as well as in the nanoparticle/cell interactions are discussed.

  7. Non-synonymous FGD3 Variant as Positional Candidate for Disproportional Tall Stature Accounting for a Carcass Weight QTL (CW-3 and Skeletal Dysplasia in Japanese Black Cattle.

    Directory of Open Access Journals (Sweden)

    Akiko Takasuga

    2015-08-01

    Full Text Available Recessive skeletal dysplasia, characterized by joint- and/or hip bone-enlargement, was mapped within the critical region for a major quantitative trait locus (QTL influencing carcass weight; previously named CW-3 in Japanese Black cattle. The risk allele was on the same chromosome as the Q allele that increases carcass weight. Phenotypic characterization revealed that the risk allele causes disproportional tall stature and bone size that increases carcass weight in heterozygous individuals but causes disproportionately narrow chest width in homozygotes. A non-synonymous variant of FGD3 was identified as a positional candidate quantitative trait nucleotide (QTN and the corresponding mutant protein showed reduced activity as a guanine nucleotide exchange factor for Cdc42. FGD3 is expressed in the growth plate cartilage of femurs from bovine and mouse. Thus, loss of FDG3 activity may lead to subsequent loss of Cdc42 function. This would be consistent with the columnar disorganization of proliferating chondrocytes in chondrocyte-specific inactivated Cdc42 mutant mice. This is the first report showing association of FGD3 with skeletal dysplasia.

  8. Error awareness revisited: accumulation of multimodal evidence from central and autonomic nervous systems.

    Science.gov (United States)

    Wessel, Jan R; Danielmeier, Claudia; Ullsperger, Markus

    2011-10-01

    The differences between erroneous actions that are consciously perceived as errors and those that go unnoticed have recently become an issue in the field of performance monitoring. In EEG studies, error awareness has been suggested to influence the error positivity (Pe) of the response-locked event-related brain potential, a positive voltage deflection prominent approximately 300 msec after error commission, whereas the preceding error-related negativity (ERN) seemed to be unaffected by error awareness. Erroneous actions, in general, have been shown to promote several changes in ongoing autonomic nervous system (ANS) activity, yet such investigations have only rarely taken into account the question of subjective error awareness. In the first part of this study, heart rate, pupillometry, and EEG were recorded during an antisaccade task to measure autonomic arousal and activity of the CNS separately for perceived and unperceived errors. Contrary to our expectations, we observed differences in both Pe and ERN with respect to subjective error awareness. This was replicated in a second experiment, using a modified version of the same task. In line with our predictions, only perceived errors provoke the previously established post-error heart rate deceleration. Also, pupil size yields a more prominent dilatory effect after an erroneous saccade, which is also significantly larger for perceived than unperceived errors. On the basis of the ERP and ANS results as well as brain-behavior correlations, we suggest a novel interpretation of the implementation and emergence of error awareness in the brain. In our framework, several systems generate input signals (e.g., ERN, sensory input, proprioception) that influence the emergence of error awareness, which is then accumulated and presumably reflected in later potentials, such as the Pe.

  9. 面颈部肿瘤影像引导精确放射治疗摆位误差的研究%Positioning errors of neck tumor accurate radiotherapy basic on image-guiding

    Institute of Scientific and Technical Information of China (English)

    郑祖安; 付秀根; 钟伟伟; 李定宇

    2012-01-01

    OBJECTIVE: To investigate the positioning errors of neck tumor accurate radiotherapy basic on itnage-guiding. METHODS : To compare the three-dimensional images between the CT images of TPS and the reconstructed images of the XVI system which dealt with the images from the cone-beam CT of the linear accelerator after scarring before the first-three radiations of the accurate radiotherapy, while the patients were positioned with the thermoplastic masks. The space errors between the two images were corrected by the accelerator. The image-guiding were repeated weekly. The data were analyzed hy the SAS statistical software. RESULTS; 91.14% of the patients with cervicaljugular tumours were involved in the correction of the space errors of the target area affter the image-guiding before the first-three radiatons of accurate radiotherapy. The space errors in the Si-orientation and fore-and-aft-orientation in the images of the the patients with cervicaljugular tumours were (-0, 91±1. 08) mm and (-0. 41±l. 43) mm,which was largger slightly than that in the right-and-left-orientation [(0. 15± 1. 09) mm], CONCLUSIONS: The image guiding avails the alevation of the space precision of the target area in the neck accurate radiotherapy. The retroversion-adduction of head and fixation of cervix should be paid great attenttions when the patients with cervicaljugular tumours are positioned.%目的:分析基于影像引导技术的面颈部肿瘤精确放疗摆位误差.方法:对79例面颈部肿瘤放疗患者行热塑网罩体位固定,前3次放疗前利用加速器机载锥形束CT行靶区部位扫描重建三维影像,与计划CT影像比对,获得两影像空间位置偏差,经影像确认后,偏差>1 mm者,予以校正,以后每周1次影像引导复核.用SAS 8.1统计软件系统处理数据.结果:91.14%的患者影像引导后需要校正,影像引导复核显示头脚方向和前后方向分别为(-0.91±1.08)mm和(-0.41士1.43)mm,左右方向为(0.15±1.09) mm.

  10. DC cancellation as a method of generating a t2-response and of solving the radial position error in a concentric free-falling two-sphere equivalence-principle experiment in a drag-free satellite

    Science.gov (United States)

    Lange, Benjamin

    2010-09-01

    This paper presents a new method for doing a free-fall equivalence-principle (EP) experiment in a satellite at ambient temperature which solves two problems that have previously blocked this approach. By using large masses to change the gravity gradient at the proof masses, the orbit dynamics of a drag-free satellite may be changed in such a way that the experiment can mimic a free-fall experiment in a constant gravitational field on the earth. An experiment using a sphere surrounded by a spherical shell both completely unsupported and free falling has previously been impractical because (1) it is not possible to distinguish between a small EP violation and a slight difference in the semi-major axes of the orbits of the two proof masses and (2) the position difference in the orbit due to an EP violation only grows as t whereas the largest disturbance grows as t3/2. Furthermore, it has not been known how to independently measure the positions of a shell and a solid sphere with sufficient accuracy. The measurement problem can be solved by using a two-color transcollimator (see the main text), and since the radial-position-error and t-response problems arise from the earth's gravity gradient and not from its gravity field, one solution is to modify the earth's gravity gradient with local masses fixed in the satellite. Since the gravity gradient at the surface of a sphere, for example, depends only on its density, the gravity gradients of laboratory masses and of the earth unlike their fields are of the same order of magnitude. In a drag-free satellite spinning perpendicular to the orbit plane, two fixed spherical masses whose connecting line parallels the satellite spin axis can generate a dc gravity gradient at test masses located between them which cancels the combined gravity gradient of the earth and differential centrifugal force. With perfect cancellation, the position-error problem vanishes and the response grows as t2 along a line which always points toward

  11. Design Accountability

    DEFF Research Database (Denmark)

    Koskinen, Ilpo; Krogh, Peter

    2015-01-01

    design research is that where classical research is interested in singling out a particular aspect and exploring it in depth, design practice is characterized by balancing numerous concerns in a heterogenous and occasionally paradoxical product. It is on this basis the notion of design accountability...

  12. Design Accountability

    DEFF Research Database (Denmark)

    Koskinen, Ilpo; Krogh, Peter

    2015-01-01

    design research is that where classical research is interested in singling out a particular aspect and exploring it in depth, design practice is characterized by balancing numerous concerns in a heterogenous and occasionally paradoxical product. It is on this basis the notion of design accountability...

  13. Antenna motion errors in bistatic SAR imagery

    Science.gov (United States)

    Wang, Ling; Yazıcı, Birsen; Cagri Yanik, H.

    2015-06-01

    Antenna trajectory or motion errors are pervasive in synthetic aperture radar (SAR) imaging. Motion errors typically result in smearing and positioning errors in SAR images. Understanding the relationship between the trajectory errors and position errors in reconstructed images is essential in forming focused SAR images. Existing studies on the effect of antenna motion errors are limited to certain geometries, trajectory error models or monostatic SAR configuration. In this paper, we present an analysis of position errors in bistatic SAR imagery due to antenna motion errors. Bistatic SAR imagery is becoming increasingly important in the context of passive imaging and multi-sensor imaging. Our analysis provides an explicit quantitative relationship between the trajectory errors and the positioning errors in bistatic SAR images. The analysis is applicable to arbitrary trajectory errors and arbitrary imaging geometries including wide apertures and large scenes. We present extensive numerical simulations to validate the analysis and to illustrate the results in commonly used bistatic configurations and certain trajectory error models.

  14. AMERICAN ACCOUNTING

    Directory of Open Access Journals (Sweden)

    Mihaela Onica

    2005-01-01

    Full Text Available The international Accounting Standards already contribute to the generation of better and more easily comparable financial information on an international level, supporting thus a more effective allocationof the investments resources in the world. Under the circumstances, there occurs the necessity of a consistent application of the standards on a global level. The financial statements are part of thefinancial reporting process. A set of complete financial statements usually includes a balance sheet,a profit and loss account, a report of the financial item change (which can be presented in various ways, for example as a status of the treasury flows and of the funds flows and those notes, as well as those explanatory situations and materials which are part of the financial statements.

  15. Spatial frequency domain error budget

    Energy Technology Data Exchange (ETDEWEB)

    Hauschildt, H; Krulewich, D

    1998-08-27

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

  16. Infrastrukturel Accountability

    DEFF Research Database (Denmark)

    Ubbesen, Morten Bonde

    Hvordan redegør man troværdigt for noget så diffust som en hel nations udledning af drivhusgasser? Det undersøger denne afhandling i et etnografisk studie af hvordan Danmarks drivhusgasregnskab udarbejdes, rapporteres og kontrolleres. Studiet trækker på begreber og forståelser fra 'Science & Tech...... & Technology Studies', og bidrager med begrebet 'infrastrukturel accountability' til nye måder at forstå og tænke om det arbejde, hvormed højt specialiserede praksisser dokumenterer og redegør for kvaliteten af deres arbejde....

  17. Infrastrukturel Accountability

    DEFF Research Database (Denmark)

    Ubbesen, Morten Bonde

    Hvordan redegør man troværdigt for noget så diffust som en hel nations udledning af drivhusgasser? Det undersøger denne afhandling i et etnografisk studie af hvordan Danmarks drivhusgasregnskab udarbejdes, rapporteres og kontrolleres. Studiet trækker på begreber og forståelser fra 'Science & Tech...... & Technology Studies', og bidrager med begrebet 'infrastrukturel accountability' til nye måder at forstå og tænke om det arbejde, hvormed højt specialiserede praksisser dokumenterer og redegør for kvaliteten af deres arbejde....

  18. Error in Monte Carlo, quasi-error in Quasi-Monte Carlo

    OpenAIRE

    Kleiss, R. H. P.; Lazopoulos, A.

    2006-01-01

    While the Quasi-Monte Carlo method of numerical integration achieves smaller integration error than standard Monte Carlo, its use in particle physics phenomenology has been hindered by the abscence of a reliable way to estimate that error. The standard Monte Carlo error estimator relies on the assumption that the points are generated independently of each other and, therefore, fails to account for the error improvement advertised by the Quasi-Monte Carlo method. We advocate the construction o...

  19. Increased taxon sampling greatly reduces phylogenetic error.

    Science.gov (United States)

    Zwickl, Derrick J; Hillis, David M

    2002-08-01

    Several authors have argued recently that extensive taxon sampling has a positive and important effect on the accuracy of phylogenetic estimates. However, other authors have argued that there is little benefit of extensive taxon sampling, and so phylogenetic problems can or should be reduced to a few exemplar taxa as a means of reducing the computational complexity of the phylogenetic analysis. In this paper we examined five aspects of study design that may have led to these different perspectives. First, we considered the measurement of phylogenetic error across a wide range of taxon sample sizes, and conclude that the expected error based on randomly selecting trees (which varies by taxon sample size) must be considered in evaluating error in studies of the effects of taxon sampling. Second, we addressed the scope of the phylogenetic problems defined by different samples of taxa, and argue that phylogenetic scope needs to be considered in evaluating the importance of taxon-sampling strategies. Third, we examined the claim that fast and simple tree searches are as effective as more thorough searches at finding near-optimal trees that minimize error. We show that a more complete search of tree space reduces phylogenetic error, especially as the taxon sample size increases. Fourth, we examined the effects of simple versus complex simulation models on taxonomic sampling studies. Although benefits of taxon sampling are apparent for all models, data generated under more complex models of evolution produce higher overall levels of error and show greater positive effects of increased taxon sampling. Fifth, we asked if different phylogenetic optimality criteria show different effects of taxon sampling. Although we found strong differences in effectiveness of different optimality criteria as a function of taxon sample size, increased taxon sampling improved the results from all the common optimality criteria. Nonetheless, the method that showed the lowest overall

  20. Displacement damage in bit error ratio performance of on-off keying, pulse position modulation, differential phase shift keying, and homodyne binary phase-shift keying-based optical intersatellite communication system.

    Science.gov (United States)

    Liu, Yun; Zhao, Shanghong; Gong, Zizheng; Zhao, Jing; Dong, Chen; Li, Xuan

    2016-04-10

    Displacement damage (DD) effect induced bit error ratio (BER) performance degradations in on-off keying (OOK), pulse position modulation (PPM), differential phase-shift keying (DPSK), and homodyne binary phase shift keying (BPSK) based systems were simulated and discussed under 1 MeV neutron irradiation to a total fluence of 1×1012  n/cm2 in this paper. Degradation of main optoelectronic devices included in communication systems were analyzed on the basis of existing experimental data. The system BER degradation was subsequently simulated and the variations of BER with different neutron irradiation location were also achieved. The result shows that DD on an Er-doped fiber amplifier (EDFA) is the dominant cause of system degradation, and a BPSK-based system performs better than the other three systems against DD. In order to improve radiation hardness of communication systems against DD, protection and enhancement of EDFA are required, and the use of a homodyne BPSK modulation scheme is a considered choice.

  1. Educational Accounting Procedures.

    Science.gov (United States)

    Tidwell, Sam B.

    This chapter of "Principles of School Business Management" reviews the functions, procedures, and reports with which school business officials must be familiar in order to interpret and make decisions regarding the school district's financial position. Among the accounting functions discussed are financial management, internal auditing,…

  2. Interlanguage Signs and Lexical Transfer Errors

    CERN Document Server

    Ro, A

    1994-01-01

    A theory of interlanguage (IL) lexicons is outlined, with emphasis on IL lexical entries, based on the HPSG notion of lexical sign. This theory accounts for idiosyncratic or lexical transfer of syntactic subcategorisation and idioms from the first language to the IL. It also accounts for developmental stages in IL lexical grammar, and grammatical variation in the use of the same lexical item. The theory offers a tool for robust parsing of lexical transfer errors and diagnosis of such errors.

  3. Meteorological Error Budget Using Open Source Data

    Science.gov (United States)

    2016-09-01

    VBA ) script was created that would read the model - based output and corresponding sounding data for each message type (METCM or METB3), output type...produce artillery MET error budget tables that account for expected errors when using MET model -based systems. Representatives of the US and other...nations within the North Atlantic Treaty Organization expressed a need for shareable model -based MET error budgets. Use of an openly available civilian

  4. TRUE AND FAIR VIEW – THE SUPREM TRUTH IN ACCOUNTING?

    Directory of Open Access Journals (Sweden)

    Ana-Maria MARCULESCU

    2013-06-01

    Full Text Available Acting in a social and economic environment in a continuous movement and transformation, accounting is experiencing with new situations, in its attempt to answer all functions and information users that it generates, making it an important arbitration instrument in the game of those involved in business world. The main characteristic of accounting is represented by providing useful information retrodictive and predictive in an efficient and economic decision process regarding the economic entity's financial position and accounting performance. Under these circumstances, the information must not contain significant errors, is not biased, and users can be confident that it accurately represents what they proposed to represent, or what is expected, in a reasonably manner to be. Fair and true view seen as an ideal to which any professional accountant should aim, seems to be more difficult to achieve under the current conditions, in which fiscal pressure is more and more unbearable and top management is more and more willing to make compromises that sometimes are at a legal limit. In theory, it is well known that registrations and accounting reports must provide a clear image, honest, fair and full on the assets, financial position and results of the entity. In practice, contrary to ethical principles, more and more "servants" of the accounting profession are either willing, or forced to submit distorted accounting information giving the impression of calmness to a disastrous situation.

  5. 5 CFR 1604.6 - Error correction.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Error correction. 1604.6 Section 1604.6 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD UNIFORMED SERVICES ACCOUNTS § 1604.6 Error correction. (a) General rule. A service member's employing agency must correct the service member's...

  6. Unexpected but Incidental Positive Outcomes Predict Real-World Gambling.

    Science.gov (United States)

    Otto, A Ross; Fleming, Stephen M; Glimcher, Paul W

    2016-03-01

    Positive mood can affect a person's tendency to gamble, possibly because positive mood fosters unrealistic optimism. At the same time, unexpected positive outcomes, often called prediction errors, influence mood. However, a linkage between positive prediction errors-the difference between expected and obtained outcomes-and consequent risk taking has yet to be demonstrated. Using a large data set of New York City lottery gambling and a model inspired by computational accounts of reward learning, we found that people gamble more when incidental outcomes in the environment (e.g., local sporting events and sunshine) are better than expected. When local sports teams performed better than expected, or a sunny day followed a streak of cloudy days, residents gambled more. The observed relationship between prediction errors and gambling was ubiquitous across the city's socioeconomically diverse neighborhoods and was specific to sports and weather events occurring locally in New York City. Our results suggest that unexpected but incidental positive outcomes influence risk taking.

  7. Adjoint Error Estimation for Linear Advection

    Energy Technology Data Exchange (ETDEWEB)

    Connors, J M; Banks, J W; Hittinger, J A; Woodward, C S

    2011-03-30

    An a posteriori error formula is described when a statistical measurement of the solution to a hyperbolic conservation law in 1D is estimated by finite volume approximations. This is accomplished using adjoint error estimation. In contrast to previously studied methods, the adjoint problem is divorced from the finite volume method used to approximate the forward solution variables. An exact error formula and computable error estimate are derived based on an abstractly defined approximation of the adjoint solution. This framework allows the error to be computed to an arbitrary accuracy given a sufficiently well resolved approximation of the adjoint solution. The accuracy of the computable error estimate provably satisfies an a priori error bound for sufficiently smooth solutions of the forward and adjoint problems. The theory does not currently account for discontinuities. Computational examples are provided that show support of the theory for smooth solutions. The application to problems with discontinuities is also investigated computationally.

  8. A Liberal Account of Addiction

    Science.gov (United States)

    Foddy, Bennett; Savulescu, Julian

    2014-01-01

    Philosophers and psychologists have been attracted to two differing accounts of addictive motivation. In this paper, we investigate these two accounts and challenge their mutual claim that addictions compromise a person’s self-control. First, we identify some incompatibilities between this claim of reduced self-control and the available evidence from various disciplines. A critical assessment of the evidence weakens the empirical argument for reduced autonomy. Second, we identify sources of unwarranted normative bias in the popular theories of addiction that introduce systematic errors in interpreting the evidence. By eliminating these errors, we are able to generate a minimal, but correct account, of addiction that presumes addicts to be autonomous in their addictive behavior, absent further evidence to the contrary. Finally, we explore some of the implications of this minimal, correct view. PMID:24659901

  9. Redundant measurements for controlling errors

    Energy Technology Data Exchange (ETDEWEB)

    Ehinger, M. H.; Crawford, J. M.; Madeen, M. L.

    1979-07-01

    Current federal regulations for nuclear materials control require consideration of operating data as part of the quality control program and limits of error propagation. Recent work at the BNFP has revealed that operating data are subject to a number of measurement problems which are very difficult to detect and even more difficult to correct in a timely manner. Thus error estimates based on operational data reflect those problems. During the FY 1978 and FY 1979 R and D demonstration runs at the BNFP, redundant measurement techniques were shown to be effective in detecting these problems to allow corrective action. The net effect is a reduction in measurement errors and a significant increase in measurement sensitivity. Results show that normal operation process control measurements, in conjunction with routine accountability measurements, are sensitive problem indicators when incorporated in a redundant measurement program.

  10. Game Design Principles based on Human Error

    Directory of Open Access Journals (Sweden)

    Guilherme Zaffari

    2016-03-01

    Full Text Available This paper displays the result of the authors’ research regarding to the incorporation of Human Error, through design principles, to video game design. In a general way, designers must consider Human Error factors throughout video game interface development; however, when related to its core design, adaptations are in need, since challenge is an important factor for fun and under the perspective of Human Error, challenge can be considered as a flaw in the system. The research utilized Human Error classifications, data triangulation via predictive human error analysis, and the expanded flow theory to allow the design of a set of principles in order to match the design of playful challenges with the principles of Human Error. From the results, it was possible to conclude that the application of Human Error in game design has a positive effect on player experience, allowing it to interact only with errors associated with the intended aesthetics of the game.

  11. PRELIMINARY ACCOUNTING WORKS FOR THE ESTABLISHMENT OF FINANCIAL STATEMENTS

    Directory of Open Access Journals (Sweden)

    HOLT GHEORGHE

    2017-02-01

    Full Text Available The preparation of financial statements is a complex process of aggregation of data and accounting information in the perspective of establishing economic and financial indicators. The adoption of a uniform set of preliminary accounting work for the closure of the current financial exercises is the only way for romanian companies to ensure that their financial situations are reliable, and on this basis, the users can make the best decisions. According to IASB Framework, the objective of financial statements is to provide information about the financial position, performance and changes in financial position of an enterprise that is useful to a wide range of users in making economic decisions: managers, shareholders, prospective investors, financial institutions, suppliers, customers, employees, competitors, general public, governments. The complexity of the accounting works preceding the financial statement preparation is determined by the large volume of theoretical and practical knowledge that can be influenced by the following factors: different accounting policies, accounting estimates, professional judgment, verifiability, measurability, fraud and error. The main objective of this scientific paper is to highlight the importance of preliminary accounting works for the annual financial statements establisment, focusing on the presentation of their chronological evidence.

  12. Generalized Gaussian Error Calculus

    CERN Document Server

    Grabe, Michael

    2010-01-01

    For the first time in 200 years Generalized Gaussian Error Calculus addresses a rigorous, complete and self-consistent revision of the Gaussian error calculus. Since experimentalists realized that measurements in general are burdened by unknown systematic errors, the classical, widespread used evaluation procedures scrutinizing the consequences of random errors alone turned out to be obsolete. As a matter of course, the error calculus to-be, treating random and unknown systematic errors side by side, should ensure the consistency and traceability of physical units, physical constants and physical quantities at large. The generalized Gaussian error calculus considers unknown systematic errors to spawn biased estimators. Beyond, random errors are asked to conform to the idea of what the author calls well-defined measuring conditions. The approach features the properties of a building kit: any overall uncertainty turns out to be the sum of a contribution due to random errors, to be taken from a confidence inter...

  13. Counting OCR errors in typeset text

    Science.gov (United States)

    Sandberg, Jonathan S.

    1995-03-01

    Frequently object recognition accuracy is a key component in the performance analysis of pattern matching systems. In the past three years, the results of numerous excellent and rigorous studies of OCR system typeset-character accuracy (henceforth OCR accuracy) have been published, encouraging performance comparisons between a variety of OCR products and technologies. These published figures are important; OCR vendor advertisements in the popular trade magazines lead readers to believe that published OCR accuracy figures effect market share in the lucrative OCR market. Curiously, a detailed review of many of these OCR error occurrence counting results reveals that they are not reproducible as published and they are not strictly comparable due to larger variances in the counts than would be expected by the sampling variance. Naturally, since OCR accuracy is based on a ratio of the number of OCR errors over the size of the text searched for errors, imprecise OCR error accounting leads to similar imprecision in OCR accuracy. Some published papers use informal, non-automatic, or intuitively correct OCR error accounting. Still other published results present OCR error accounting methods based on string matching algorithms such as dynamic programming using Levenshtein (edit) distance but omit critical implementation details (such as the existence of suspect markers in the OCR generated output or the weights used in the dynamic programming minimization procedure). The problem with not specifically revealing the accounting method is that the number of errors found by different methods are significantly different. This paper identifies the basic accounting methods used to measure OCR errors in typeset text and offers an evaluation and comparison of the various accounting methods.

  14. Classification of Spreadsheet Errors

    OpenAIRE

    Rajalingham, Kamalasen; Chadwick, David R.; Knight, Brian

    2008-01-01

    This paper describes a framework for a systematic classification of spreadsheet errors. This classification or taxonomy of errors is aimed at facilitating analysis and comprehension of the different types of spreadsheet errors. The taxonomy is an outcome of an investigation of the widespread problem of spreadsheet errors and an analysis of specific types of these errors. This paper contains a description of the various elements and categories of the classification and is supported by appropri...

  15. Errors analysis of prone position in intensity modulated radiation therapy of cervical cancer%子宫颈癌俯卧位调强放射治疗摆位误差分析

    Institute of Scientific and Technical Information of China (English)

    邢晓汾; 郭瑞嵩; 臧志芳; 王鹤皋; 靳宏星

    2011-01-01

    Objective To study the spatial distribution of set-up errors for cervical cancer with intensity modulated radiation therapy (IMRT) and to provide referential safety margin out of clinical tumor volume (CTV) during treatment plan design. Methods Six patients with cervical cancer were treated with IMRT in prone position, belly board and thermoplastic cast was used for immobilization. Measurement were made on a daily basis setup under five consecutive treatments with electron portal images device (EPID).Portal films from two projection (one anter-posterior and one opposite lateral)were taken. Sixty portal films were analyzed. The translational and rotational deviations were analyzed by registering and comparing the bony structures of EPID and digitally reconstructed radiographs (DRR). Results The translational deviations were (3.1 ±1.8) mm, (3.9 ±3.3) mm, (4.2 ±2.6) mm in medi-lateral, cranio-caudal and anterior-posterior directions, the rotational deviations were in coronal plane (0.8±0.9)° and sagittal plane (1.2±1)°. Conclusion For the patients with cervical cancer undergoing IMRT, the margins between the CTV and PTV should be 7.1 mm in lateral direction, 10.4 mm in cranio-caudal and 10.8 mm in anterior-posterior directions. The sign on patients body can help to reduce the setup errors.%目的 研究子宫颈癌俯卧位调强放射治疗的摆位误差大小,为子宫颈癌调强放疗计划设计临床靶区体积(CTV)外放计划靶区体积(PTV)时提供参考数据.方法 选取行俯卧位调强放射治疗的子宫颈癌患者6例,所有病例治疗时身下垫有孔泡沫板,热塑成形固定膜固定.连续5 d治疗时用电子射野影像装置(EPID)拍射正侧位验证片各1张,共60张验证片,通过配准数字化重建图像(DRR)和EPID拍摄的验证片的骨性解剖结构,计算平移和旋转误差.结果 平移误差:左右方向为(3.1±1.8)mm、头脚方向为(3.9±3.3)mm、腹背方向为(4.2±2.6)mm;旋转误差冠状面为(0.8±0

  16. Total quality accounting

    Directory of Open Access Journals (Sweden)

    Andrijašević Maja

    2008-01-01

    Full Text Available The focus of competitive "battle" shifted from the price towards non-price instruments, above all, towards quality that became the key variable for profitability increase and achievement of better comparative position of a company. Under such conditions, management of a company, which, according to the established and certified system of total quality, strives towards achieving of a better market position, faces the problem of quality cost measurement and determination. Management, above all, cost accounting can help in solving of this problem, but the question is how much of its potential is being used for that purpose.

  17. Errors in CT colonography.

    Science.gov (United States)

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

    2015-10-01

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

  18. Model error estimation in ensemble data assimilation

    Directory of Open Access Journals (Sweden)

    S. Gillijns

    2007-01-01

    Full Text Available A new methodology is proposed to estimate and account for systematic model error in linear filtering as well as in nonlinear ensemble based filtering. Our results extend the work of Dee and Todling (2000 on constant bias errors to time-varying model errors. In contrast to existing methodologies, the new filter can also deal with the case where no dynamical model for the systematic error is available. In the latter case, the applicability is limited by a matrix rank condition which has to be satisfied in order for the filter to exist. The performance of the filter developed in this paper is limited by the availability and the accuracy of observations and by the variance of the stochastic model error component. The effect of these aspects on the estimation accuracy is investigated in several numerical experiments using the Lorenz (1996 model. Experimental results indicate that the availability of a dynamical model for the systematic error significantly reduces the variance of the model error estimates, but has only minor effect on the estimates of the system state. The filter is able to estimate additive model error of any type, provided that the rank condition is satisfied and that the stochastic errors and measurement errors are significantly smaller than the systematic errors. The results of this study are encouraging. However, it remains to be seen how the filter performs in more realistic applications.

  19. Explaining errors in children's questions.

    Science.gov (United States)

    Rowland, Caroline F

    2007-07-01

    The ability to explain the occurrence of errors in children's speech is an essential component of successful theories of language acquisition. The present study tested some generativist and constructivist predictions about error on the questions produced by ten English-learning children between 2 and 5 years of age. The analyses demonstrated that, as predicted by some generativist theories [e.g. Santelmann, L., Berk, S., Austin, J., Somashekar, S. & Lust. B. (2002). Continuity and development in the acquisition of inversion in yes/no questions: dissociating movement and inflection, Journal of Child Language, 29, 813-842], questions with auxiliary DO attracted higher error rates than those with modal auxiliaries. However, in wh-questions, questions with modals and DO attracted equally high error rates, and these findings could not be explained in terms of problems forming questions with why or negated auxiliaries. It was concluded that the data might be better explained in terms of a constructivist account that suggests that entrenched item-based constructions may be protected from error in children's speech, and that errors occur when children resort to other operations to produce questions [e.g. Dabrowska, E. (2000). From formula to schema: the acquisition of English questions. Cognitive Liguistics, 11, 83-102; Rowland, C. F. & Pine, J. M. (2000). Subject-auxiliary inversion errors and wh-question acquisition: What children do know? Journal of Child Language, 27, 157-181; Tomasello, M. (2003). Constructing a language: A usage-based theory of language acquisition. Cambridge, MA: Harvard University Press]. However, further work on constructivist theory development is required to allow researchers to make predictions about the nature of these operations.

  20. Error Estimation for Indoor 802.11 Location Fingerprinting

    DEFF Research Database (Denmark)

    Lemelson, Hendrik; Kjærgaard, Mikkel Baun; Hansen, Rene

    2009-01-01

    that is inherent to 802.11-based positioning systems can be estimated.  Knowing the position error is crucial for many applications that rely on position information: End users could be informed about the estimated position error to avoid frustration in case the system gives faulty position information. Service...

  1. Firewall Configuration Errors Revisited

    CERN Document Server

    Wool, Avishai

    2009-01-01

    The first quantitative evaluation of the quality of corporate firewall configurations appeared in 2004, based on Check Point FireWall-1 rule-sets. In general that survey indicated that corporate firewalls were often enforcing poorly written rule-sets, containing many mistakes. The goal of this work is to revisit the first survey. The current study is much larger. Moreover, for the first time, the study includes configurations from two major vendors. The study also introduce a novel "Firewall Complexity" (FC) measure, that applies to both types of firewalls. The findings of the current study indeed validate the 2004 study's main observations: firewalls are (still) poorly configured, and a rule-set's complexity is (still) positively correlated with the number of detected risk items. Thus we can conclude that, for well-configured firewalls, ``small is (still) beautiful''. However, unlike the 2004 study, we see no significant indication that later software versions have fewer errors (for both vendors).

  2. Towards formulating an accounting theory of meaningfulness

    OpenAIRE

    S. Wedzerai ,Musvoto; Gouws, Daan G

    2012-01-01

    This study highlights the need for a theory of meaningfulness for accounting information. A theory of meaningfulness determines the theoretical position that may be taken about the scientific content of information. The need for such a theory in accounting arises from the perspective that users of accounting information have not been able to take a firm theoretical position about the scientific content of accounting information in the financial statements. This has caused users of accounting ...

  3. INTERPRETATION, COPING & ACCOUNTABILITY IN SOCIAL ACCOUNTING

    OpenAIRE

    Lehman, Glen

    2013-01-01

    Many accountants and accounting theorists believe that objective accounts of the external world are possible. This paper critiques such arguments via an examination of the ethical assumptions underpinning social and environmental accounting. In the early 1990s, David Solomons and Tony Tinker debated the idea that accounting was a fair, just and neutral means to represent reality. On the one hand, Tinker argued that accounting reports are simply artificial constructions and are not objectiv...

  4. 12 CFR 226.13 - Billing error resolution. 27

    Science.gov (United States)

    2010-01-01

    ..., 12 CFR 205.11 governing error resolution rather than those of paragraphs (a), (b), (c), (e), (f), and... account, the creditor shall comply with the requirements of Regulation E, 12 CFR 205.11 governing error... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Billing error resolution. 27 226.13 Section...

  5. Reducing medication errors.

    Science.gov (United States)

    Nute, Christine

    2014-11-25

    Most nurses are involved in medicines management, which is integral to promoting patient safety. Medicines management is prone to errors, which depending on the error can cause patient injury, increased hospital stay and significant legal expenses. This article describes a new approach to help minimise drug errors within healthcare settings where medications are prescribed, dispensed or administered. The acronym DRAINS, which considers all aspects of medicines management before administration, was devised to reduce medication errors on a cardiothoracic intensive care unit.

  6. Service Science And Accounting

    Directory of Open Access Journals (Sweden)

    Stephen G. Kerr

    2011-05-01

    Full Text Available The evolution of a new discipline of service science will creatively disturb the relationship between more established business disciplines.  Each discipline is not an independent silo.  As a result the purpose of this paper was to explore, at this early stage, how the new discipline may create opportunities for interdisciplinary scholarship.  The specific purpose of this paper was to explore how service science might interact with the scholarly and professional practice of accountingAccounting practice is dominated by a stewardship proposition.  The stewardship proposition is a problem because typical service science investments will receive unfavorable treatment.  Accounting’s other major proposition is valuation.  Areas of opportunity for positive contributions from a service science approach are discussed.  Service science, as viewed through an accounting lens, will have to find ways to overcome measurement and reporting methods that will not afford service science investments the full benefit of their strategic potential.  Several avenues for research into ways service science can improve accounting scholarship are suggested.

  7. Error effects in anterior cingulate cortex reverse when error likelihood is high

    Science.gov (United States)

    Jessup, Ryan K.; Busemeyer, Jerome R.; Brown, Joshua W.

    2010-01-01

    Strong error-related activity in medial prefrontal cortex (mPFC) has been shown repeatedly with neuroimaging and event-related potential studies for the last several decades. Multiple theories have been proposed to account for error effects, including comparator models and conflict detection models, but the neural mechanisms that generate error signals remain in dispute. Typical studies use relatively low error rates, confounding the expectedness and the desirability of an error. Here we show with a gambling task and fMRI that when losses are more frequent than wins, the mPFC error effect disappears, and moreover, exhibits the opposite pattern by responding more strongly to unexpected wins than losses. These findings provide perspective on recent ERP studies and suggest that mPFC error effects result from a comparison between actual and expected outcomes. PMID:20203206

  8. ACCOUNTING HARMONIZATION AND HISTORICAL COST ACCOUNTING

    Directory of Open Access Journals (Sweden)

    Valentin Gabriel CRISTEA

    2017-05-01

    Full Text Available There is a huge interest in accounting harmonization and historical costs accounting, in what they offer us. In this article, different valuation models are discussed. Although one notices the movement from historical cost accounting to fair value accounting, each one has its advantages.

  9. Demand Forecasting Errors

    OpenAIRE

    Mackie, Peter; Nellthorp, John; Laird, James

    2005-01-01

    Demand forecasts form a key input to the economic appraisal. As such any errors present within the demand forecasts will undermine the reliability of the economic appraisal. The minimization of demand forecasting errors is therefore important in the delivery of a robust appraisal. This issue is addressed in this note by introducing the key issues, and error types present within demand fore...

  10. Large errors and severe conditions

    CERN Document Server

    Smith, D L; Van Wormer, L A

    2002-01-01

    Physical parameters that can assume real-number values over a continuous range are generally represented by inherently positive random variables. However, if the uncertainties in these parameters are significant (large errors), conventional means of representing and manipulating the associated variables can lead to erroneous results. Instead, all analyses involving them must be conducted in a probabilistic framework. Several issues must be considered: First, non-linear functional relations between primary and derived variables may lead to significant 'error amplification' (severe conditions). Second, the commonly used normal (Gaussian) probability distribution must be replaced by a more appropriate function that avoids the occurrence of negative sampling results. Third, both primary random variables and those derived through well-defined functions must be dealt with entirely in terms of their probability distributions. Parameter 'values' and 'errors' should be interpreted as specific moments of these probabil...

  11. Evaluation Of Statistical Models For Forecast Errors From The HBV-Model

    Science.gov (United States)

    Engeland, K.; Kolberg, S.; Renard, B.; Stensland, I.

    2009-04-01

    Three statistical models for the forecast errors for inflow to the Langvatn reservoir in Northern Norway have been constructed and tested according to how well the distribution and median values of the forecasts errors fit to the observations. For the first model observed and forecasted inflows were transformed by the Box-Cox transformation before a first order autoregressive model was constructed for the forecast errors. The parameters were conditioned on climatic conditions. In the second model the Normal Quantile Transformation (NQT) was applied on observed and forecasted inflows before a similar first order autoregressive model was constructed for the forecast errors. For the last model positive and negative errors were modeled separately. The errors were first NQT-transformed before a model where the mean values were conditioned on climate, forecasted inflow and yesterday's error. To test the three models we applied three criterions: We wanted a) the median values to be close to the observed values; b) the forecast intervals to be narrow; c) the distribution to be correct. The results showed that it is difficult to obtain a correct model for the forecast errors, and that the main challenge is to account for the auto-correlation in the errors. Model 1 and 2 gave similar results, and the main drawback is that the distributions are not correct. The 95% forecast intervals were well identified, but smaller forecast intervals were over-estimated, and larger intervals were under-estimated. Model 3 gave a distribution that fits better, but the median values do not fit well since the auto-correlation is not properly accounted for. If the 95% forecast interval is of interest, Model 2 is recommended. If the whole distribution is of interest, Model 3 is recommended.

  12. Structural similarity and category-specificity: a refined account

    DEFF Research Database (Denmark)

    Gerlach, Christian; Law, Ian

    2004-01-01

    It has been suggested that category-specific recognition disorders for natural objects may reflect that natural objects are more structurally (visually) similar than artefacts and therefore more difficult to recognize following brain damage. On this account one might expect a positive relationship...... range of candidate integral units will be activated and compete for selection, thus explaining the higher error rate associated with animals. We evaluate the model based on previous evidence from both normal subjects and patients with category-specific disorders and argue that this model can help...

  13. Measurement error in geometric morphometrics.

    Science.gov (United States)

    Fruciano, Carmelo

    2016-06-01

    Geometric morphometrics-a set of methods for the statistical analysis of shape once saluted as a revolutionary advancement in the analysis of morphology -is now mature and routinely used in ecology and evolution. However, a factor often disregarded in empirical studies is the presence and the extent of measurement error. This is potentially a very serious issue because random measurement error can inflate the amount of variance and, since many statistical analyses are based on the amount of "explained" relative to "residual" variance, can result in loss of statistical power. On the other hand, systematic bias can affect statistical analyses by biasing the results (i.e. variation due to bias is incorporated in the analysis and treated as biologically-meaningful variation). Here, I briefly review common sources of error in geometric morphometrics. I then review the most commonly used methods to measure and account for both random and non-random measurement error, providing a worked example using a real dataset.

  14. Analysis of errors in forensic science

    Directory of Open Access Journals (Sweden)

    Mingxiao Du

    2017-01-01

    Full Text Available Reliability of expert testimony is one of the foundations of judicial justice. Both expert bias and scientific errors affect the reliability of expert opinion, which in turn affects the trustworthiness of the findings of fact in legal proceedings. Expert bias can be eliminated by replacing experts; however, it may be more difficult to eliminate scientific errors. From the perspective of statistics, errors in operation of forensic science include systematic errors, random errors, and gross errors. In general, process repetition and abiding by the standard ISO/IEC:17025: 2005, general requirements for the competence of testing and calibration laboratories, during operation are common measures used to reduce errors that originate from experts and equipment, respectively. For example, to reduce gross errors, the laboratory can ensure that a test is repeated several times by different experts. In applying for forensic principles and methods, the Federal Rules of Evidence 702 mandate that judges consider factors such as peer review, to ensure the reliability of the expert testimony. As the scientific principles and methods may not undergo professional review by specialists in a certain field, peer review serves as an exclusive standard. This study also examines two types of statistical errors. As false-positive errors involve a higher possibility of an unfair decision-making, they should receive more attention than false-negative errors.

  15. Accounting for Non-Accounting Students: What Affects Their Performance?

    Directory of Open Access Journals (Sweden)

    Suhaiza Ismail

    2012-04-01

    Full Text Available This study aims to examine the factors affecting the examination performance of non-accounting students in completing an accounting course, that is, Management Accounting. A questionnaire survey was administered to a total of 147 non-accounting students who enrolled in a Management Accounting course for a semester. The factors considered are gender, prior academic performance, year of study and learning approaches adopted which include deep, surface and strategic approaches. Using multiple regression analysis, the results reveal that prior academic performance and year of study have a positive significant impact on performance while the surface approach of learning has a negative significant impact on the performance of the students. This present study mainly focused on the overall performance of the students and did not investigate the effect of the factors on the performance of the various assessment components in Management accounting course. The findings imply that the Management Accounting course should be offered to higher level non-accounting students. In addition, for completing the course with good results, the surface approach to learning should be avoided. The present study is unique as it considers the students performance in a subject that is not the main discipline of the students (i.e., accounting course for non-accounting students.

  16. Systematic error revisited

    Energy Technology Data Exchange (ETDEWEB)

    Glosup, J.G.; Axelrod, M.C.

    1996-08-05

    The American National Standards Institute (ANSI) defines systematic error as An error which remains constant over replicative measurements. It would seem from the ANSI definition that a systematic error is not really an error at all; it is merely a failure to calibrate the measurement system properly because if error is constant why not simply correct for it? Yet systematic errors undoubtedly exist, and they differ in some fundamental way from the kind of errors we call random. Early papers by Eisenhart and by Youden discussed systematic versus random error with regard to measurements in the physical sciences, but not in a fundamental way, and the distinction remains clouded by controversy. The lack of a general agreement on definitions has led to a plethora of different and often confusing methods on how to quantify the total uncertainty of a measurement that incorporates both its systematic and random errors. Some assert that systematic error should be treated by non- statistical methods. We disagree with this approach, and we provide basic definitions based on entropy concepts, and a statistical methodology for combining errors and making statements of total measurement of uncertainty. We illustrate our methods with radiometric assay data.

  17. Laser measurement and analysis of reposition error in polishing systems

    Science.gov (United States)

    Liu, Weisen; Wang, Junhua; Xu, Min; He, Xiaoying

    2015-10-01

    In this paper, robotic reposition error measurement method based on laser interference remote positioning is presented, the geometric error is analyzed in the polishing system based on robot and the mathematical model of the tilt error is presented. Studies show that less than 1 mm error is mainly caused by the tilt error with small incident angle. Marking spot position with interference fringe enhances greatly the error measurement precision, the measurement precision of tilt error can reach 5 um. Measurement results show that reposition error of the polishing system is mainly from the tilt error caused by the motor A, repositioning precision is greatly increased after polishing system improvement. The measurement method has important applications in the actual error measurement with low cost, simple operation.

  18. Error in Monte Carlo, quasi-error in Quasi-Monte Carlo

    CERN Document Server

    Kleiss, R H

    2006-01-01

    While the Quasi-Monte Carlo method of numerical integration achieves smaller integration error than standard Monte Carlo, its use in particle physics phenomenology has been hindered by the abscence of a reliable way to estimate that error. The standard Monte Carlo error estimator relies on the assumption that the points are generated independently of each other and, therefore, fails to account for the error improvement advertised by the Quasi-Monte Carlo method. We advocate the construction of an estimator of stochastic nature, based on the ensemble of pointsets with a particular discrepancy value. We investigate the consequences of this choice and give some first empirical results on the suggested estimators.

  19. The Learning Objective Catalogue for Patient Safety in Undergraduate Medical Education – A Position Statement of the Committee for Patient Safety and Error Management of the German Association for Medical Education

    Directory of Open Access Journals (Sweden)

    Kiesewetter, Jan

    2016-02-01

    Full Text Available Background: Since the report “To err is human” was published by the Institute of Medicine in the year 2000, topics regarding patient safety and error management are in the focal point of interest of science and politics. Despite international attention, a structured and comprehensive medical education regarding these topics remains to be missing.Goals: The Learning Objective Catalogue for Patient Safety described below the Committee for Patient Safety and Error Management of the German Association for Medical Education (GMA has aimed to establish a common foundation for the structured implementation of patient safety curricula at the medical faculties in German-speaking countries. Methods: The development the Learning Objective Catalogue resulted via the participation of 13 faculties in two committee meetings, two multi-day workshops, and additional judgments of external specialists.Results: The Committee of Patient Safety and Error Management of GMA developed the present Learning Objective Catalogue for Patient Safety in Undergraduate Medical Education, structured in three chapters: , and . The learning objectives within the chapters are organized on three levels with a hierarchical organization of the topics. Overall, the Learning Objective Catalogue consists of 38 learning objectives. All learning objectives are referenced with the National Competency-based Catalogue of Learning Objectives for Undergraduate Medical Education.Discussion: The Learning Objective Catalogue for Patient Safety in Undergraduate Medical Education is a product that was developed through collaboration of members from 13 medical faculties. In the German-speaking countries, the Learning Objective Catalogue should advance discussion regarding the topics of patient safety and error management and help develop subsequent educational structures. The Learning Objective Catalogue for Patient Safety can serve as a common ground for an intensified, constructive, subject

  20. Analytic standard errors for exploratory process factor analysis.

    Science.gov (United States)

    Zhang, Guangjian; Browne, Michael W; Ong, Anthony D; Chow, Sy Miin

    2014-07-01

    Exploratory process factor analysis (EPFA) is a data-driven latent variable model for multivariate time series. This article presents analytic standard errors for EPFA. Unlike standard errors for exploratory factor analysis with independent data, the analytic standard errors for EPFA take into account the time dependency in time series data. In addition, factor rotation is treated as the imposition of equality constraints on model parameters. Properties of the analytic standard errors are demonstrated using empirical and simulated data.

  1. Error Resilient Video Compression Using Behavior Models

    Directory of Open Access Journals (Sweden)

    Jacco R. Taal

    2004-03-01

    Full Text Available Wireless and Internet video applications are inherently subjected to bit errors and packet errors, respectively. This is especially so if constraints on the end-to-end compression and transmission latencies are imposed. Therefore, it is necessary to develop methods to optimize the video compression parameters and the rate allocation of these applications that take into account residual channel bit errors. In this paper, we study the behavior of a predictive (interframe video encoder and model the encoders behavior using only the statistics of the original input data and of the underlying channel prone to bit errors. The resulting data-driven behavior models are then used to carry out group-of-pictures partitioning and to control the rate of the video encoder in such a way that the overall quality of the decoded video with compression and channel errors is optimized.

  2. Error Modelling and Experimental Validation for a Planar 3-PPR Parallel Manipulator

    DEFF Research Database (Denmark)

    Wu, Guanglei; Bai, Shaoping; Kepler, Jørgen Asbøl

    2011-01-01

    In this paper, the positioning error of a 3-PPR planar parallel manipulator is studied with an error model and experimental validation. First, the displacement and workspace are analyzed. An error model considering both configuration errors and joint clearance errors is established. Using...... this model, the maximum positioning error was estimated for a U-shape PPR planar manipulator, the results being compared with the experimental measurements. It is found that the error distributions from the simulation is approximate to that of themeasurements....

  3. Error Modelling and Experimental Validation for a Planar 3-PPR Parallel Manipulator

    DEFF Research Database (Denmark)

    Wu, Guanglei; Bai, Shaoping; Kepler, Jørgen Asbøl

    2011-01-01

    In this paper, the positioning error of a 3-PPR planar parallel manipulator is studied with an error model and experimental validation. First, the displacement and workspace are analyzed. An error model considering both configuration errors and joint clearance errors is established. Using...... this model, the maximum positioning error was estimated for a U-shape PPR planar manipulator, the results being compared with the experimental measurements. It is found that the error distributions from the simulation is approximate to that of themeasurements....

  4. Researcher positioning

    DEFF Research Database (Denmark)

    Mørck, Line Lerche; Khawaja, Iram

    2009-01-01

    abstract  This article focuses on the complex and multi-layered process of researcher positioning, specifically in relation to the politically sensitive study of marginalised and ‘othered' groups such as Muslims living in Denmark. We discuss the impact of different ethnic, religious and racial...... political and personal involvement by the researcher, which challenges traditional perspectives on research and researcher positioning. A key point in this regard is the importance of constant awareness of and reflection on the multiple ways in which one's positioning as a researcher influences the research...... process. Studying the other calls for close reflections on one's own position, theoretically, personally, and politically, taking into account one's complicity in either overcoming or reproducing processes of othering and marginalisation. [i] We use the term (ethnic) minoritised, not as a distinction...

  5. Simulation of Inertial Navigation System Errors at Aerial Photography from Uav

    Science.gov (United States)

    Shults, R.

    2017-05-01

    The problem of accuracy determination of the UAV position using INS at aerial photography can be resolved in two different ways: modelling of measurement errors or in-field calibration for INS. The paper presents the results of INS errors research by mathematical modelling. In paper were considered the following steps: developing of INS computer model; carrying out INS simulation; using reference data without errors, estimation of errors and their influence on maps creation accuracy by UAV data. It must be remembered that the values of orientation angles and the coordinates of the projection centre may change abruptly due to the influence of the atmosphere (different air density, wind, etc.). Therefore, the mathematical model of the INS was constructed taking into account the use of different models of wind gusts. For simulation were used typical characteristics of micro electromechanical (MEMS) INS and parameters of standard atmosphere. According to the simulation established domination of INS systematic errors that accumulate during the execution of photographing and require compensation mechanism, especially for orientation angles. MEMS INS have a high level of noise at the system input. Thanks to the developed model, we are able to investigate separately the impact of noise in the absence of systematic errors. According to the research was found that on the interval of observations in 5 seconds the impact of random and systematic component is almost the same. The developed model of INS errors studies was implemented in Matlab software environment and without problems can be improved and enhanced with new blocks.

  6. The effect of retrospective sampling on estimates of prediction error for multifactor dimensionality reduction.

    Science.gov (United States)

    Winham, Stacey J; Motsinger-Reif, Alison A

    2011-01-01

    The standard in genetic association studies of complex diseases is replication and validation of positive results, with an emphasis on assessing the predictive value of associations. In response to this need, a number of analytical approaches have been developed to identify predictive models that account for complex genetic etiologies. Multifactor Dimensionality Reduction (MDR) is a commonly used, highly successful method designed to evaluate potential gene-gene interactions. MDR relies on classification error in a cross-validation framework to rank and evaluate potentially predictive models. Previous work has demonstrated the high power of MDR, but has not considered the accuracy and variance of the MDR prediction error estimate. Currently, we evaluate the bias and variance of the MDR error estimate as both a retrospective and prospective estimator and show that MDR can both underestimate and overestimate error. We argue that a prospective error estimate is necessary if MDR models are used for prediction, and propose a bootstrap resampling estimate, integrating population prevalence, to accurately estimate prospective error. We demonstrate that this bootstrap estimate is preferable for prediction to the error estimate currently produced by MDR. While demonstrated with MDR, the proposed estimation is applicable to all data-mining methods that use similar estimates.

  7. Error measuring system of rotary Inductosyn

    Science.gov (United States)

    Liu, Chengjun; Zou, Jibin; Fu, Xinghe

    2008-10-01

    The inductosyn is a kind of high-precision angle-position sensor. It has important applications in servo table, precision machine tool and other products. The precision of inductosyn is calibrated by its error. It's an important problem about the error measurement in the process of production and application of the inductosyn. At present, it mainly depends on the method of artificial measurement to obtain the error of inductosyn. Therefore, the disadvantages can't be ignored such as the high labour intensity of the operator, the occurrent error which is easy occurred and the poor repeatability, and so on. In order to solve these problems, a new automatic measurement method is put forward in this paper which based on a high precision optical dividing head. Error signal can be obtained by processing the output signal of inductosyn and optical dividing head precisely. When inductosyn rotating continuously, its zero position error can be measured dynamically, and zero error curves can be output automatically. The measuring and calculating errors caused by man-made factor can be overcome by this method, and it makes measuring process more quickly, exactly and reliably. Experiment proves that the accuracy of error measuring system is 1.1 arc-second (peak - peak value).

  8. Modeling habitat dynamics accounting for possible misclassification

    Science.gov (United States)

    Veran, Sophie; Kleiner, Kevin J.; Choquet, Remi; Collazo, Jaime; Nichols, James D.

    2012-01-01

    Land cover data are widely used in ecology as land cover change is a major component of changes affecting ecological systems. Landscape change estimates are characterized by classification errors. Researchers have used error matrices to adjust estimates of areal extent, but estimation of land cover change is more difficult and more challenging, with error in classification being confused with change. We modeled land cover dynamics for a discrete set of habitat states. The approach accounts for state uncertainty to produce unbiased estimates of habitat transition probabilities using ground information to inform error rates. We consider the case when true and observed habitat states are available for the same geographic unit (pixel) and when true and observed states are obtained at one level of resolution, but transition probabilities estimated at a different level of resolution (aggregations of pixels). Simulation results showed a strong bias when estimating transition probabilities if misclassification was not accounted for. Scaling-up does not necessarily decrease the bias and can even increase it. Analyses of land cover data in the Southeast region of the USA showed that land change patterns appeared distorted if misclassification was not accounted for: rate of habitat turnover was artificially increased and habitat composition appeared more homogeneous. Not properly accounting for land cover misclassification can produce misleading inferences about habitat state and dynamics and also misleading predictions about species distributions based on habitat. Our models that explicitly account for state uncertainty should be useful in obtaining more accurate inferences about change from data that include errors.

  9. Accounting Fundamentals for Non-Accountants

    Science.gov (United States)

    The purpose of this module is to provide an introduction and overview of accounting fundamentals for non-accountants. The module also covers important topics such as communication, internal controls, documentation and recordkeeping.

  10. CHANGES IN PRIOR PERIOD ERRORS

    OpenAIRE

    Alina Pietraru; Dorina Luţă

    2007-01-01

    In 2007, in Romania is continued the gradual implementation of the International Financial Reporting Standards which includes: the IFRS, the IAS and their Interpretation as approved by European Union, translated and published in Romanian. The financial statement must achieve one major purpose that is to provide information about the financial position, financial performance and changes in financial position of that entity. In this context, the accounting policy elaborated and assumed by the m...

  11. ACCOUNTING TREATMENTS USED FOR ACCOUNTING SERVICES PROVIDERS

    OpenAIRE

    ŢOGOE GRETI DANIELA; AVRAM MARIOARA; AVRAM COSTIN DANIEL

    2014-01-01

    The theme of our research is the ways of keeping accounting entities that are the object of the provision of services in the accounting profession. This paper aims to achieve a parallel between the ways of organizing financial records - accounting provided by freelancers and companies with activity in the financial - accounting. The first step in our scientific research is to establish objectives chosen area of scientific knowledge. Our scientific approach seeks to explain thr...

  12. Accounting: Accountants Need Verbal Skill Training

    Science.gov (United States)

    Whitaker, Bruce L.

    1978-01-01

    Verbal skills training is one aspect of accounting education not usually included in secondary and postsecondary accounting courses. The author discusses the need for verbal competency and methods of incorporating it into accounting courses, particularly a variation of the Keller plan of individualized instruction. (MF)

  13. VOLUMETRIC ERROR COMPENSATION IN FIVE-AXIS CNC MACHINING CENTER THROUGH KINEMATICS MODELING OF GEOMETRIC ERROR

    Directory of Open Access Journals (Sweden)

    Pooyan Vahidi Pashsaki

    2016-06-01

    Full Text Available Accuracy of a five-axis CNC machine tool is affected by a vast number of error sources. This paper investigates volumetric error modeling and its compensation to the basis for creation of new tool path for improvement of work pieces accuracy. The volumetric error model of a five-axis machine tool with the configuration RTTTR (tilting head B-axis and rotary table in work piece side A΄ was set up taking into consideration rigid body kinematics and homogeneous transformation matrix, in which 43 error components are included. Volumetric error comprises 43 error components that can separately reduce geometrical and dimensional accuracy of work pieces. The machining accuracy of work piece is guaranteed due to the position of the cutting tool center point (TCP relative to the work piece. The cutting tool is deviated from its ideal position relative to the work piece and machining error is experienced. For compensation process detection of the present tool path and analysis of the RTTTR five-axis CNC machine tools geometrical error, translating current position of component to compensated positions using the Kinematics error model, converting newly created component to new tool paths using the compensation algorithms and finally editing old G-codes using G-code generator algorithm have been employed.

  14. Surprised at all the entropy: hippocampal, caudate and midbrain contributions to learning from prediction errors.

    Directory of Open Access Journals (Sweden)

    Anne-Marike Schiffer

    Full Text Available Influential concepts in neuroscientific research cast the brain a predictive machine that revises its predictions when they are violated by sensory input. This relates to the predictive coding account of perception, but also to learning. Learning from prediction errors has been suggested for take place in the hippocampal memory system as well as in the basal ganglia. The present fMRI study used an action-observation paradigm to investigate the contributions of the hippocampus, caudate nucleus and midbrain dopaminergic system to different types of learning: learning in the absence of prediction errors, learning from prediction errors, and responding to the accumulation of prediction errors in unpredictable stimulus configurations. We conducted analyses of the regions of interests' BOLD response towards these different types of learning, implementing a bootstrapping procedure to correct for false positives. We found both, caudate nucleus and the hippocampus to be activated by perceptual prediction errors. The hippocampal responses seemed to relate to the associative mismatch between a stored representation and current sensory input. Moreover, its response was significantly influenced by the average information, or Shannon entropy of the stimulus material. In accordance with earlier results, the habenula was activated by perceptual prediction errors. Lastly, we found that the substantia nigra was activated by the novelty of sensory input. In sum, we established that the midbrain dopaminergic system, the hippocampus, and the caudate nucleus were to different degrees significantly involved in the three different types of learning: acquisition of new information, learning from prediction errors and responding to unpredictable stimulus developments. We relate learning from perceptual prediction errors to the concept of predictive coding and related information theoretic accounts.

  15. Probabilistic quantum error correction

    CERN Document Server

    Fern, J; Fern, Jesse; Terilla, John

    2002-01-01

    There are well known necessary and sufficient conditions for a quantum code to correct a set of errors. We study weaker conditions under which a quantum code may correct errors with probabilities that may be less than one. We work with stabilizer codes and as an application study how the nine qubit code, the seven qubit code, and the five qubit code perform when there are errors on more than one qubit. As a second application, we discuss the concept of syndrome quality and use it to suggest a way that quantum error correction can be practically improved.

  16. Safeguards Accountability Network accountability and materials management

    Energy Technology Data Exchange (ETDEWEB)

    Carnival, G.J.; Meredith, E.M.

    1985-01-01

    The Safeguards Accountability Network (SAN) is a computerized on-line accountability system for the safeguards accountability control of nuclear materials inventories at Rocky Flats Plant. SAN is a dedicated accountability system utilizing source documents filled out on the shop floor as its base. The system incorporates double entry accounting and is developed around the Material Balance Area (MBA) concept. MBA custodians enter transaction information from source documents prepared by personnel in the process areas directly into the SAN system. This provides a somewhat near-real time perpetual inventory system which has limited interaction with MBA custodians. MBA custodians are permitted to inquire into the system and status items on inventory. They are also responsible for the accuracy of the accountability information used as input to the system for their MBA. Monthly audits by the Nuclear Materials Control group assure the timeliness and accuracy of SAN accountability information.

  17. 肝癌术后简化调强放疗临床靶体积误差的锥形束CT分析%Analysis of clinical target volume positioning errors using cone beam computed tomography for patients with liver tumors with postoperative simplefied intensity-modulated radiotherapy

    Institute of Scientific and Technical Information of China (English)

    张涛; 王维虎; 金晶; 王淑莲; 宋永文; 刘跃平; 戴建荣; 李晔雄

    2012-01-01

    目的 通过锥形束CT (CBCT)分析肝癌患者术后简化调强放疗分次间和分次内的临床靶体积(CTV)误差.方法 12例肝癌患者放疗前、后均行CBCT.在瘤床放置金属标记,配准框包全所有金属标记,不包括肋骨、椎体等骨质,使用自动骨性配准.若放疗前平移误差>3mm和(或)旋转误差>3°则行在线校位后重复CBCT.12例患者共行214次CBCT成111组数据,111组可计算分次间左右(x)、头脚(y)、前后(z)方向CTV误差,70组可计算分次内CTV误差.计划靶体积(PTV)边界计算公式为2.0∑ +0.7σ(∑为系统误差,σ为随机误差).结果 x、y、z方向上分次间CTV平移误差分别为-0.03、-0.43、1.02 mm,∑分别为1.50、5.89、1.97 mm,σ分别为1.76、4.13、2.42 mm;分次内平移误差分别为0.04、0.86、-0.46 mm,∑分别为0.46、1.14、0.31 mm,σ分别为0.95、1.38、0.91 mm.PTV边界在x、y、z方向上分别为4.5、15.0、5.8mm.结论 肝癌患者简化调强放疗时CTV误差不可避免,使用术中放置瘤床金属标记行CBCT获得的数据真实准确.%Objective To evaluate the inter-and intra-fractional clinical target volume (CTV) positioning errors of patients receiving postoperative simplified intensity-modulated radiotherapy (SIMRT) using cone beam computed tomography (CBCT).Methods Twelve patients with liver tumors underwent postoperative SIMRT.CBCT images were acquired before and after the treatment.The clipbox volume for registration included the fiducial markers in the tumor bed and excluded the ribs and vertebral bodies.If any translational parameter of setup error before treatment exceeded 3 mm or rotational parameter exceeded 3°,the treatment couch was adjusted and a verification CBCT was acquired to assess residual setup error.Automatic bone match was used.A total of 214 acquisitions of CBCTs in 111 groups were analyzed.Inter-fractional translational CTV positioning errors in left-right (x),superior-inferior (y) and anterior

  18. Correction for quadrature errors

    DEFF Research Database (Denmark)

    Netterstrøm, A.; Christensen, Erik Lintz

    1994-01-01

    In high bandwidth radar systems it is necessary to use quadrature devices to convert the signal to/from baseband. Practical problems make it difficult to implement a perfect quadrature system. Channel imbalance and quadrature phase errors in the transmitter and the receiver result in error signal...

  19. ERRORS AND CORRECTION

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    To err is human . Since the 1960s, most second language teachers or language theorists have regarded errors as natural and inevitable in the language learning process . Instead of regarding them as terrible and disappointing, teachers have come to realize their value. This paper will consider these values, analyze some errors and propose some effective correction techniques.

  20. ACCOUNTING TREATMENTS USED FOR ACCOUNTING SERVICES PROVIDERS

    Directory of Open Access Journals (Sweden)

    ŢOGOE GRETI DANIELA

    2014-08-01

    Full Text Available The theme of our research is the ways of keeping accounting entities that are the object of the provision of services in the accounting profession. This paper aims to achieve a parallel between the ways of organizing financial records - accounting provided by freelancers and companies with activity in the financial - accounting. The first step in our scientific research is to establish objectives chosen area of scientific knowledge. Our scientific approach seeks to explain through a thorough and detailed approach as different sides (conceptual and practical looking projections of accounting issues related to regulatory developments and practices in the field. This paper addresses various concepts, accounting treatments, and books and accounting documents used both freelancers in providing accounting services and legal persons authorized accounting profession. In terms of methodology and research perspective, the whole scientific approach combined with quantitative and qualitative research theoretical perspective (descriptive-conceptual with practice perspective (empirical analyzing the main contributions of various authors (Romanian and foreign to knowledge in the field. Following the survey believe that the amendments to the national legislation will support entities providing accounting services, by cutting red tape on Administrative Burdens, and consequently will increase profitability and increase service quality.

  1. ERROR AND ERROR CORRECTION AT ELEMENTARY LEVEL

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Introduction Errors are unavoidable in language learning, however, to a great extent, teachers in most middle schools in China regard errors as undesirable, a sign of failure in language learning. Most middle schools are still using the grammar-translation method which aims at encouraging students to read scientific works and enjoy literary works. The other goals of this method are to gain a greater understanding of the first language and to improve the students’ ability to cope with difficult subjects and materials, i.e. to develop the students’ minds. The practical purpose of using this method is to help learners pass the annual entrance examination. "To achieve these goals, the students must first learn grammar and vocabulary,... Grammar is taught deductively by means of long and elaborate explanations... students learn the rules of the language rather than its use." (Tang Lixing, 1983:11-12)

  2. Errors on errors - Estimating cosmological parameter covariance

    CERN Document Server

    Joachimi, Benjamin

    2014-01-01

    Current and forthcoming cosmological data analyses share the challenge of huge datasets alongside increasingly tight requirements on the precision and accuracy of extracted cosmological parameters. The community is becoming increasingly aware that these requirements not only apply to the central values of parameters but, equally important, also to the error bars. Due to non-linear effects in the astrophysics, the instrument, and the analysis pipeline, data covariance matrices are usually not well known a priori and need to be estimated from the data itself, or from suites of large simulations. In either case, the finite number of realisations available to determine data covariances introduces significant biases and additional variance in the errors on cosmological parameters in a standard likelihood analysis. Here, we review recent work on quantifying these biases and additional variances and discuss approaches to remedy these effects.

  3. Measuring Test Measurement Error: A General Approach

    Science.gov (United States)

    Boyd, Donald; Lankford, Hamilton; Loeb, Susanna; Wyckoff, James

    2013-01-01

    Test-based accountability as well as value-added asessments and much experimental and quasi-experimental research in education rely on achievement tests to measure student skills and knowledge. Yet, we know little regarding fundamental properties of these tests, an important example being the extent of measurement error and its implications for…

  4. The impact of measurement errors in the identification of regulatory networks

    Directory of Open Access Journals (Sweden)

    Sato João R

    2009-12-01

    Full Text Available Abstract Background There are several studies in the literature depicting measurement error in gene expression data and also, several others about regulatory network models. However, only a little fraction describes a combination of measurement error in mathematical regulatory networks and shows how to identify these networks under different rates of noise. Results This article investigates the effects of measurement error on the estimation of the parameters in regulatory networks. Simulation studies indicate that, in both time series (dependent and non-time series (independent data, the measurement error strongly affects the estimated parameters of the regulatory network models, biasing them as predicted by the theory. Moreover, when testing the parameters of the regulatory network models, p-values computed by ignoring the measurement error are not reliable, since the rate of false positives are not controlled under the null hypothesis. In order to overcome these problems, we present an improved version of the Ordinary Least Square estimator in independent (regression models and dependent (autoregressive models data when the variables are subject to noises. Moreover, measurement error estimation procedures for microarrays are also described. Simulation results also show that both corrected methods perform better than the standard ones (i.e., ignoring measurement error. The proposed methodologies are illustrated using microarray data from lung cancer patients and mouse liver time series data. Conclusions Measurement error dangerously affects the identification of regulatory network models, thus, they must be reduced or taken into account in order to avoid erroneous conclusions. This could be one of the reasons for high biological false positive rates identified in actual regulatory network models.

  5. Error Analysis of Robotic Assembly System Based on Screw Theory

    Institute of Scientific and Technical Information of China (English)

    韩卫军; 费燕琼; 赵锡芳

    2003-01-01

    Assembly errors have great influence on assembly quality in robotic assembly systems. Error analysis is directed to the propagations and accumula-tions of various errors and their effect on assembly success.Using the screw coordinates, assembly errors are represented as "error twist", the extremely compact expression. According to the law of screw composition, relative position and orientation errors of mating parts are computed and the necessary condition of assembly success is concluded. A new simple method for measuring assembly errors is also proposed based on the transformation law of a screw.Because of the compact representation of error, the model presented for error analysis can be applied to various part- mating types and especially useful for error analysis of complexity assembly.

  6. Uncorrected refractive errors

    Directory of Open Access Journals (Sweden)

    Kovin S Naidoo

    2012-01-01

    Full Text Available Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC, were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR Development, Service Development and Social Entrepreneurship.

  7. Uncorrected refractive errors.

    Science.gov (United States)

    Naidoo, Kovin S; Jaggernath, Jyoti

    2012-01-01

    Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC), were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR) Development, Service Development and Social Entrepreneurship.

  8. Errors in neuroradiology.

    Science.gov (United States)

    Caranci, Ferdinando; Tedeschi, Enrico; Leone, Giuseppe; Reginelli, Alfonso; Gatta, Gianluca; Pinto, Antonio; Squillaci, Ettore; Briganti, Francesco; Brunese, Luca

    2015-09-01

    Approximately 4 % of radiologic interpretation in daily practice contains errors and discrepancies that should occur in 2-20 % of reports. Fortunately, most of them are minor degree errors, or if serious, are found and corrected with sufficient promptness; obviously, diagnostic errors become critical when misinterpretation or misidentification should significantly delay medical or surgical treatments. Errors can be summarized into four main categories: observer errors, errors in interpretation, failure to suggest the next appropriate procedure, failure to communicate in a timely and a clinically appropriate manner. Misdiagnosis/misinterpretation percentage should rise up in emergency setting and in the first moments of the learning curve, as in residency. Para-physiological and pathological pitfalls in neuroradiology include calcification and brain stones, pseudofractures, and enlargement of subarachnoid or epidural spaces, ventricular system abnormalities, vascular system abnormalities, intracranial lesions or pseudolesions, and finally neuroradiological emergencies. In order to minimize the possibility of error, it is important to be aware of various presentations of pathology, obtain clinical information, know current practice guidelines, review after interpreting a diagnostic study, suggest follow-up studies when appropriate, communicate significant abnormal findings appropriately and in a timely fashion directly with the treatment team.

  9. Delphi Accounts Receivable Module -

    Data.gov (United States)

    Department of Transportation — Delphi accounts receivable module contains the following data elements, but are not limited to customer information, cash receipts, line of accounting details, bill...

  10. Rank Modulation for Translocation Error Correction

    CERN Document Server

    Farnoud, Farzad; Milenkovic, Olgica

    2012-01-01

    We consider rank modulation codes for flash memories that allow for handling arbitrary charge drop errors. Unlike classical rank modulation codes used for correcting errors that manifest themselves as swaps of two adjacently ranked elements, the proposed \\emph{translocation rank codes} account for more general forms of errors that arise in storage systems. Translocations represent a natural extension of the notion of adjacent transpositions and as such may be analyzed using related concepts in combinatorics and rank modulation coding. Our results include tight bounds on the capacity of translocation rank codes, construction techniques for asymptotically good codes, as well as simple decoding methods for one class of structured codes. As part of our exposition, we also highlight the close connections between the new code family and permutations with short common subsequences, deletion and insertion error-correcting codes for permutations and permutation arrays.

  11. Error estimation and adaptivity for incompressible hyperelasticity

    KAUST Repository

    Whiteley, J.P.

    2014-04-30

    SUMMARY: A Galerkin FEM is developed for nonlinear, incompressible (hyper) elasticity that takes account of nonlinearities in both the strain tensor and the relationship between the strain tensor and the stress tensor. By using suitably defined linearised dual problems with appropriate boundary conditions, a posteriori error estimates are then derived for both linear functionals of the solution and linear functionals of the stress on a boundary, where Dirichlet boundary conditions are applied. A second, higher order method for calculating a linear functional of the stress on a Dirichlet boundary is also presented together with an a posteriori error estimator for this approach. An implementation for a 2D model problem with known solution, where the entries of the strain tensor exhibit large, rapid variations, demonstrates the accuracy and sharpness of the error estimators. Finally, using a selection of model problems, the a posteriori error estimate is shown to provide a basis for effective mesh adaptivity. © 2014 John Wiley & Sons, Ltd.

  12. Improving Localization Accuracy: Successive Measurements Error Modeling

    Directory of Open Access Journals (Sweden)

    Najah Abu Ali

    2015-07-01

    Full Text Available Vehicle self-localization is an essential requirement for many of the safety applications envisioned for vehicular networks. The mathematical models used in current vehicular localization schemes focus on modeling the localization error itself, and overlook the potential correlation between successive localization measurement errors. In this paper, we first investigate the existence of correlation between successive positioning measurements, and then incorporate this correlation into the modeling positioning error. We use the Yule Walker equations to determine the degree of correlation between a vehicle’s future position and its past positions, and then propose a -order Gauss–Markov model to predict the future position of a vehicle from its past  positions. We investigate the existence of correlation for two datasets representing the mobility traces of two vehicles over a period of time. We prove the existence of correlation between successive measurements in the two datasets, and show that the time correlation between measurements can have a value up to four minutes. Through simulations, we validate the robustness of our model and show that it is possible to use the first-order Gauss–Markov model, which has the least complexity, and still maintain an accurate estimation of a vehicle’s future location over time using only its current position. Our model can assist in providing better modeling of positioning errors and can be used as a prediction tool to improve the performance of classical localization algorithms such as the Kalman filter.

  13. Dynamics of serial position change in probe-recognition task

    Directory of Open Access Journals (Sweden)

    Fifić Mario

    2002-01-01

    Full Text Available Relationship between practice and serial position effects was investigated, in order to obtain more evidence for underlying short-term memory processes. The investigated relationship is termed the dynamics of serial position change. To address this issue, the present study investigated mean latency, errors, and performed Ex-Gaussian convolution analysis. In six-block trials the probe-recognition task was used in the so-called fast experimental procedure. The serial position effect was significant in all six blocks. Both primacy and recency effects were detected, with primacy located in the first two blocks, producing a non-linear serial position effect. Although the serial position function became linear from the third block on, the convolution analysis revealed a non-linear change of the normal distribution parameter, suggesting special status of the last two serial positions. Further, separation of convolution parameters for serial position and practice was observed, suggesting different underlying mechanisms. In order to account for these findings, a strategy shift mechanism is suggested, rather then a mechanism based on changing the manner of memory scanning. Its influence is primarily located at the very beginning of the experimental session. The pattern of results of errors regarding the dynamics of serial position change closely paralleled those on reaction times. Several models of short-term memory were evaluated in order to account for these findings.

  14. Rotational Alignment Altered by Source Position Correlations

    Science.gov (United States)

    Jacobs, Chris S.; Heflin, M. B.; Lanyi, G. E.; Sovers, O. J.; Steppe, J. A.

    2010-01-01

    In the construction of modern Celestial Reference Frames (CRFs) the overall rotational alignment is only weakly constrained by the data. Therefore, common practice has been to apply a 3-dimensional No-Net-Rotation (NNR) constraint in order to align an under-construction frame to the ICRF. We present evidence that correlations amongst source position parameters must be accounted for in order to properly align a CRF at the 5-10 (mu)as level of uncertainty found in current work. Failure to do so creates errors at the 10-40 (mu)as level.

  15. The District Nursing Clinical Error Reduction Programme.

    Science.gov (United States)

    McGraw, Caroline; Topping, Claire

    2011-01-01

    The District Nursing Clinical Error Reduction (DANCER) Programme was initiated in NHS Islington following an increase in the number of reported medication errors. The objectives were to reduce the actual degree of harm and the potential risk of harm associated with medication errors and to maintain the existing positive reporting culture, while robustly addressing performance issues. One hundred medication errors reported in 2007/08 were analysed using a framework that specifies the factors that predispose to adverse medication events in domiciliary care. Various contributory factors were identified and interventions were subsequently developed to address poor drug calculation and medication problem-solving skills and incorrectly transcribed medication administration record charts. Follow up data were obtained at 12 months and two years. The evaluation has shown that although medication errors do still occur, the programme has resulted in a marked shift towards a reduction in the associated actual degree of harm and the potential risk of harm.

  16. Probe Error Modeling Research Based on Bayesian Network

    Institute of Scientific and Technical Information of China (English)

    Wu Huaiqiang; Xing Zilong; Zhang Jian; Yan Yan

    2015-01-01

    Probe calibration is carried out under specific conditions; most of the error caused by the change of speed parameter has not been corrected. In order to reduce the measuring error influence on measurement accuracy, this article analyzes the relationship between speed parameter and probe error, and use Bayesian network to establish the model of probe error. Model takes account of prior knowledge and sample data, with the updating of data, which can reflect the change of the errors of the probe and constantly revised modeling results.

  17. How "accountable" are accountable care organizations?

    Science.gov (United States)

    Addicott, Rachael; Shortell, Stephen M

    2014-01-01

    The establishment of accountable care organizations (ACOs) in the Affordable Care Act (ACA) was intended to support both cost savings and high-quality care. However, a key challenge will be to ensure that governance and accountability mechanisms are sufficient to support those twin ambitions. This exploratory study considers how recently developed ACOs have established governance structures and accountability mechanisms, particularly focusing on attempts at collaborative accountability and shared governance arrangements. Four case studies of ACOs across the United States were undertaken, with data collected throughout 2012. These involved 34 semistructured interviews with ACO administrative and clinical leaders, observation of nine meetings, and a review of documentary materials from each ACO. We identified very few examples of physicians being held to account as a collective and therefore only limited evidence of collaborative accountability impacting on behavior change. However, ACO leaders do have many mechanisms available to stimulate change across physicians. The challenge is to determine governance structure(s) and accountability mechanisms that facilitate the most effective combination of approaches, measures, incentives, and sanctions to achieve the goals of more accountable care. Accountability structures and processes will need to be tailored to local membership composition, historical evolution, and current stage of development. There are also some common lessons to be drawn. Shared goals and incentives should be reflected through performance criteria. It is important to align measures and thresholds across payers to ensure ACOs are not unnecessarily burdened or compromised by reporting on different and potentially disjointed measures. Finally, emphasis needs to be placed on the importance of credible, transparent data. This exploratory study provides early evidence regarding how ACOs are establishing their governance and accountability arrangements and

  18. Gender Wage Gap Accounting: The Role of Selection Bias.

    Science.gov (United States)

    Bar, Michael; Kim, Seik; Leukhina, Oksana

    2015-10-01

    Mulligan and Rubinstein (2008) (MR) argued that changing selection of working females on unobservable characteristics, from negative in the 1970s to positive in the 1990s, accounted for nearly the entire closing of the gender wage gap. We argue that their female wage equation estimates are inconsistent. Correcting this error substantially weakens the role of the rising selection bias (39 % versus 78 %) and strengthens the contribution of declining discrimination (42 % versus 7 %). Our findings resonate better with related literature. We also explain why our finding of positive selection in the 1970s provides additional support for MR's main hypothesis that an exogenous rise in the market value of unobservable characteristics contributed to the closing of the gender gap.

  19. Uticaj mesta ugradnje inercijalnog mernog bloka i akcelerometara na grešku u određivanju pozicije aviona / Size effect of the inertial measurement unit and inside IMU accelerometers on aircraft position error

    Directory of Open Access Journals (Sweden)

    Slobodan Janićijević

    2003-03-01

    Full Text Available U ovom članku analiziran je uticaj mesta ugradnje inercijalnog mernog bloka (IMB u avionu i mesta ugradnje akcelerometara u IMB na tačnost određivanja pozicije pomoću bes-platformskog inercijalnog navigacijskog sistema (BINS. Pokazano je da se ovi uticaji ne mogu uvek zanemariti. Izračunata je ukupna greška u određivanju pozicije aviona ako se IMB ugrađuje van centra rotacije aviona, a akcelerometri van centra IMB. Predložena je optimalna orijentacija akcelerometara u IMB-u, kako bi se minimizirao uticaj ugradnje akcelerometara van centra IMB na tačnost određivanja pozicije aviona. Predložen je i način kompenzacije greške. / This paper analyzes the mounting offset size effect of the inertial measurement unit (IMU in aircraft and accelerometers mounting offset size effect in the IMU on the accuracy of strap down inertial navigation system (SDINS. It is also shown that these effects cannot be always neglected. The total size effect error for the IMU has been the computed. An accelerometers optimum orientation inside the IMU has been proposed to minimize size effects on the accuracy of navigation parameters. A manner to compensate these size effects has been proposed as well.

  20. Study and realization on positioning error-checking of Excel in design of Protel DXP PCB%Excel在Protel DXP PCB设计中定位查错研究与实现

    Institute of Scientific and Technical Information of China (English)

    周泽湘

    2013-01-01

    Aiming at the Protel DXP course being set up extensively in electronics specialty vocational academy,the stu-dents usually make some unavoidable mistakes in the process of PCB design when they do not have the proficient experience of Protel DXP design. These mistakes may lead to the failure of PCB design thoroughly. The limitations and shortcomings of artifi-cial check were solved by research and practice of the quick inspection and error check function of Excel in the Protel DXP cir-cuit design.%  针对高等职业院校电子类专业广泛开设了Protel DXP课程,学生不具备熟练的Protel DXP设计经验之时,在PCB设计过程中通常会出现一些无法避免的错误。这些错误将会导致PCB设计彻底失败。通过对Excel在Protel DXP电路设计中快速检查、纠错的应用研究与实践,高效解决了人工检查的局限性、缺限性。

  1. A Harmonious Accounting Duo?

    Science.gov (United States)

    Schapperle, Robert F.; Hardiman, Patrick F.

    1992-01-01

    Accountants have urged "harmonization" of standards between the Governmental Accounting Standards Board and the Financial Accounting Standards Board, recommending similar reporting of like transactions. However, varying display of similar accounting events does not necessarily indicate disharmony. The potential for problems because of…

  2. Inpatients’ medical prescription errors

    Directory of Open Access Journals (Sweden)

    Aline Melo Santos Silva

    2009-09-01

    Full Text Available Objective: To identify and quantify the most frequent prescription errors in inpatients’ medical prescriptions. Methods: A survey of prescription errors was performed in the inpatients’ medical prescriptions, from July 2008 to May 2009 for eight hours a day. Rresults: At total of 3,931 prescriptions was analyzed and 362 (9.2% prescription errors were found, which involved the healthcare team as a whole. Among the 16 types of errors detected in prescription, the most frequent occurrences were lack of information, such as dose (66 cases, 18.2% and administration route (26 cases, 7.2%; 45 cases (12.4% of wrong transcriptions to the information system; 30 cases (8.3% of duplicate drugs; doses higher than recommended (24 events, 6.6% and 29 cases (8.0% of prescriptions with indication but not specifying allergy. Cconclusion: Medication errors are a reality at hospitals. All healthcare professionals are responsible for the identification and prevention of these errors, each one in his/her own area. The pharmacist is an essential professional in the drug therapy process. All hospital organizations need a pharmacist team responsible for medical prescription analyses before preparation, dispensation and administration of drugs to inpatients. This study showed that the pharmacist improves the inpatient’s safety and success of prescribed therapy.

  3. MODELING OF MANUFACTURING ERRORS FOR PIN-GEAR ELEMENTS OF PLANETARY GEARBOX

    Directory of Open Access Journals (Sweden)

    Ivan M. Egorov

    2014-11-01

    Full Text Available Theoretical background for calculation of k-h-v type cycloid reducers was developed relatively long ago. However, recently the matters of cycloid reducer design again attracted heightened attention. The reason for that is that such devices are used in many complex engineering systems, particularly, in mechatronic and robotics systems. The development of advanced technological capabilities for manufacturing of such reducers today gives the possibility for implementation of essential features of such devices: high efficiency, high gear ratio, kinematic accuracy and smooth motion. The presence of an adequate mathematical model gives the possibility for adjusting kinematic accuracy of the reducer by rational selection of manufacturing tolerances for its parts. This makes it possible to automate the design process for cycloid reducers with account of various factors including technological ones. A mathematical model and mathematical technique have been developed giving the possibility for modeling the kinematic error of the reducer with account of multiple factors, including manufacturing errors. The errors are considered in the way convenient for prediction of kinematic accuracy early at the manufacturing stage according to the results of reducer parts measurement on coordinate measuring machines. During the modeling, the wheel manufacturing errors are determined by the eccentricity and radius deviation of the pin tooth centers circle, and the deviation between the pin tooth axes positions and the centers circle. The satellite manufacturing errors are determined by the satellite eccentricity deviation and the satellite rim eccentricity. Due to the collinearity, the pin tooth and pin tooth hole diameter errors and the satellite tooth profile errors for a designated contact point are integrated into one deviation. Software implementation of the model makes it possible to estimate the pointed errors influence on satellite rotation angle error and

  4. ECONOMIST VERSUS ACCOUNTANT IN ROMANIA

    Directory of Open Access Journals (Sweden)

    SABOU FELICIA

    2016-02-01

    Full Text Available The paper presents how it is perceived the accountant profession and the economist profession, by the companies who provide jobs for these two professions, using the most important jobs sites from Romania. The study was made in November 2015, on a total of 86 companies who offered jobs for accountant and economist, using ejos.ro job site and 61 companies who offered jobs for accountant and economist, using bestjobs.ro job site. Analyzing this practice met in Romania, through the company offer the “accountant” job although the position is in reality for the "economist" job, I tried to explain this wrong tendency using the term accountant in place of economist.

  5. Experimental research on English vowel errors analysis

    Directory of Open Access Journals (Sweden)

    Huang Qiuhua

    2016-01-01

    Full Text Available Our paper analyzed relevant acoustic parameters of people’s speech samples and the results that compared with English standard pronunciation with methods of experimental phonetics by phonetic analysis software and statistical analysis software. Then we summarized phonetic pronunciation errors of college students through the analysis of English pronunciation of vowels, we found that college students’ English pronunciation are easy occur tongue position and lip shape errors during pronounce vowels. Based on analysis of pronunciation errors, we put forward targeted voice training for college students’ English pronunciation, eventually increased the students learning interest, and improved the teaching of English phonetics.

  6. Forecast errors in IEA-countries' energy consumption

    DEFF Research Database (Denmark)

    Linderoth, Hans

    2002-01-01

    Every year Policy of IEA Countries includes a forecast of the energy consumption in the member countries. Forecasts concerning the years 1985,1990 and 1995 can now be compared to actual values. The second oil crisis resulted in big positive forecast errors. The oil price drop in 1986 did not have...... a similar opposite effect. A correction for economic growth reduces forecast errors during the second oil crisis but not elsewhere. Industry has a relatively big positive error while transportation has a negative forecast error. Even when the forecast error is small, the results are not so "nice" because...

  7. ACCOUNTING INFORMATION RELEVANCE ON CAPITAL MARKETS

    Directory of Open Access Journals (Sweden)

    Ciprian-Dan COSTEA

    2015-06-01

    Full Text Available The research in accounting with specific application on capital markets represents a special resort of accounting research. The development of such studies was favored by the evolution and strong growth of capital markets in our daily contemporary life and by the extention of base accounting concepts to international level. In such circumstances, studies regarding the evolution of concepts like value relevance, efficient markets, accounting information and its dissemination, fair value, are welcomed on the field of accounting research with applicability to the capital markets. This study comes to outline some positions regarding this topic of accounting research.

  8. ACCOUNTING INFORMATION RELEVANCE ON CAPITAL MARKETS

    Directory of Open Access Journals (Sweden)

    Ciprian-Dan COSTEA

    2015-06-01

    Full Text Available The research in accounting with specific application on capital markets represents a special resort of accounting research. The development of such studies was favored by the evolution and strong growth of capital markets in our daily contemporary life and by the extention of base accounting concepts to international level. In such circumstances, studies regarding the evolution of concepts like value relevance, efficient markets, accounting information and its dissemination, fair value, are welcomed on the field of accounting research with applicability to the capital markets. This study comes to outline some positions regarding this topic of accounting research.

  9. Error analysis of compensation cutting technique for wavefront error of KH2PO4 crystal.

    Science.gov (United States)

    Tie, Guipeng; Dai, Yifan; Guan, Chaoliang; Zhu, Dengchao; Song, Bing

    2013-09-20

    Considering the wavefront error of KH(2)PO(4) (KDP) crystal is difficult to control through face fly cutting process because of surface shape deformation during vacuum suction, an error compensation technique based on a spiral turning method is put forward. An in situ measurement device is applied to measure the deformed surface shape after vacuum suction, and the initial surface figure error, which is obtained off-line, is added to the in situ surface shape to obtain the final surface figure to be compensated. Then a three-axis servo technique is utilized to cut the final surface shape. In traditional cutting processes, in addition to common error sources such as the error in the straightness of guide ways, spindle rotation error, and error caused by ambient environment variance, three other errors, the in situ measurement error, position deviation error, and servo-following error, are the main sources affecting compensation accuracy. This paper discusses the effect of these three errors on compensation accuracy and provides strategies to improve the final surface quality. Experimental verification was carried out on one piece of KDP crystal with the size of Φ270 mm×11 mm. After one compensation process, the peak-to-valley value of the transmitted wavefront error dropped from 1.9λ (λ=632.8 nm) to approximately 1/3λ, and the mid-spatial-frequency error does not become worse when the frequency of the cutting tool trajectory is controlled by use of a low-pass filter.

  10. Fair value accounting

    OpenAIRE

    Shamkuts, Volha, 1977-

    2010-01-01

    The thesis is devoted to fair value accounting. Fair value accounting implies that assets and liabilities get measured and reported in firm´s financial statements at their market value. The purpose of the thesis is to analyze the conceptual foundations of fair value accounting. The thesis is organized in the following way. First, origins and development of fair value accounting are discussed. Second, overview of fair value accounting is presented. The overview includes de...

  11. Assessing in financial account

    OpenAIRE

    VACKOVÁ, Lenka

    2011-01-01

    The aim of this thesis is to define possibilities of valuation and their impacts on the function of accounting. Furthermore the comparison of valuation methods within the czech accounting standards with international standards (IAS/IFRS). Valuation is metodical element which has huge influence on use value of information provided by accounting system. It affects the predicative capability of accounting information, mainly the items in accounting document. Monetary expression of company assets...

  12. Cosmic error and the statistics of large scale structure

    CERN Document Server

    Szapudi, I; Szapudi, Istvan; Colombi, Stephane

    1995-01-01

    We examine the errors on counts in cells extracted from galaxy surveys. The measurement error, related to the finite number of sampling cells, is disentangled from the ``cosmic error'', due to the finiteness of the survey. Using the hierarchical model and assuming locally Poisson behavior, we identified three contributions to the cosmic error: The finite volume effect is proportional to the average of the two-point correlation function over the whole survey. It accounts for possible fluctuations of the density field at scales larger than the sample size. The edge effect is related to the geometry of the survey. It accounts for the fact that objects near the boundary carry less statistical weight than those further away from it. The discreteness effect is due to the fact that the underlying smooth random field is sampled with finite number of objects. This is the ``shot noise'' error. Measurements of errors in artificial hierarchical samples showed excellent agreement with our predictions. The probability dist...

  13. A New Method of Error Compensation for Numerical Control System

    Institute of Scientific and Technical Information of China (English)

    夏蔚军; 吴智铭; 李济顺; 张洛平

    2003-01-01

    This paper presents a method of rapid machine tool error modeling, separation, and compensation using grating ruler. A robust modeling procedure for geometric errors is developed and a fast data processing algorithm is designed by using the error separation technique. After compensation with the new method, the maximum position error of the experiment workbench can be reduced from 400μm to 15μm. The experimental results show the effectiveness and accuracy of this method.

  14. Error monitoring in musicians

    Directory of Open Access Journals (Sweden)

    Clemens eMaidhof

    2013-07-01

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

  15. Safeguards Accountability Network accountability and materials management

    Energy Technology Data Exchange (ETDEWEB)

    Carnival, G.J.; Meredith, E.M.

    1985-01-01

    The Safeguards Accountability Network (SAN) is an on-line accountability system used by Rocky Flats Plant to provide accountability control of its nuclear material inventory. The system is also used to monitor and evaluate the use of the nuclear material inventory against programmatic objectives for materials management. The SAN system utilizes two Harris 800 Computers as central processing units. Enhancement plans are currently being formulated to provide automated data collection from process operations on the shop floor and from non-destructive analysis safeguards instrumentation. SAN, discussed in this paper, is an excellent system for basic accountability control of nuclear materials inventories and is a quite useful tool in evaluating the efficient use of nuclear materials inventories at Rocky Flats Plant.

  16. Nurse-physician communication: an organizational accountability.

    Science.gov (United States)

    Arford, Patricia H

    2005-01-01

    Dysfunctional nurse-physician communication has been linked to medication errors, patient injuries, and patient deaths. The organization is accountable for providing a context that supports effective nurse-physician communication. Organizational strategies to create such a context are synthesized from the structural, human resource, political, and cultural frameworks of organizational behavior.

  17. Accountability in Health Care

    DEFF Research Database (Denmark)

    Vrangbæk, Karsten; Byrkjeflot, Haldor

    2016-01-01

    The debate on accountability within the public sector has been lively in the past decade. Significant progress has been made in developing conceptual frameworks and typologies for characterizing different features and functions of accountability. However, there is a lack of sector specific...... adjustment of such frameworks. In this article we present a framework for analyzing accountability within health care. The paper makes use of the concept of "accountability regime" to signify the combination of different accountability forms, directions and functions at any given point in time. We show...... that reforms can introduce new forms of accountability, change existing accountability relations or change the relative importance of different accountability forms. They may also change the dominant direction and shift the balance between different functions of accountability. We further suggest...

  18. Smoothing error pitfalls

    Science.gov (United States)

    von Clarmann, T.

    2014-09-01

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

  19. Error framing effects on performance: cognitive, motivational, and affective pathways.

    Science.gov (United States)

    Steele-Johnson, Debra; Kalinoski, Zachary T

    2014-01-01

    Our purpose was to examine whether positive error framing, that is, making errors salient and cuing individuals to see errors as useful, can benefit learning when task exploration is constrained. Recent research has demonstrated the benefits of a newer approach to training, that is, error management training, that includes the opportunity to actively explore the task and framing errors as beneficial to learning complex tasks (Keith & Frese, 2008). Other research has highlighted the important role of errors in on-the-job learning in complex domains (Hutchins, 1995). Participants (N = 168) from a large undergraduate university performed a class scheduling task. Results provided support for a hypothesized path model in which error framing influenced cognitive, motivational, and affective factors which in turn differentially affected performance quantity and quality. Within this model, error framing had significant direct effects on metacognition and self-efficacy. Our results suggest that positive error framing can have beneficial effects even when tasks cannot be structured to support extensive exploration. Whereas future research can expand our understanding of error framing effects on outcomes, results from the current study suggest that positive error framing can facilitate learning from errors in real-time performance of tasks.

  20. Learning from Errors

    Directory of Open Access Journals (Sweden)

    MA. Lendita Kryeziu

    2015-06-01

    Full Text Available “Errare humanum est”, a well known and widespread Latin proverb which states that: to err is human, and that people make mistakes all the time. However, what counts is that people must learn from mistakes. On these grounds Steve Jobs stated: “Sometimes when you innovate, you make mistakes. It is best to admit them quickly, and get on with improving your other innovations.” Similarly, in learning new language, learners make mistakes, thus it is important to accept them, learn from them, discover the reason why they make them, improve and move on. The significance of studying errors is described by Corder as: “There have always been two justifications proposed for the study of learners' errors: the pedagogical justification, namely that a good understanding of the nature of error is necessary before a systematic means of eradicating them could be found, and the theoretical justification, which claims that a study of learners' errors is part of the systematic study of the learners' language which is itself necessary to an understanding of the process of second language acquisition” (Corder, 1982; 1. Thus the importance and the aim of this paper is analyzing errors in the process of second language acquisition and the way we teachers can benefit from mistakes to help students improve themselves while giving the proper feedback.

  1. Error Correction in Classroom

    Institute of Scientific and Technical Information of China (English)

    Dr. Grace Zhang

    2000-01-01

    Error correction is an important issue in foreign language acquisition. This paper investigates how students feel about the way in which error correction should take place in a Chinese-as-a foreign-language classroom, based on empirical data of a large scale. The study shows that there is a general consensus that error correction is necessary. In terms of correction strategy, the students preferred a combination of direct and indirect corrections, or a direct only correction. The former choice indicates that students would be happy to take either so long as the correction gets done.Most students didn't mind peer correcting provided it is conducted in a constructive way. More than halfofthe students would feel uncomfortable ifthe same error they make in class is corrected consecutively more than three times. Taking these findings into consideration, we may want to cncourage peer correcting, use a combination of correction strategies (direct only if suitable) and do it in a non-threatening and sensitive way. It is hoped that this study would contribute to the effectiveness of error correction in a Chinese language classroom and it may also have a wider implication on other languages.

  2. Coordinating sentence composition with error correction: A multilevel analysis

    Directory of Open Access Journals (Sweden)

    Van Waes, L.

    2011-01-01

    Full Text Available Error analysis involves detecting and correcting discrepancies between the 'text produced so far' (TPSF and the writer's mental representation of what the text should be. While many factors determine the choice of strategy, cognitive effort is a major contributor to this choice. This research shows how cognitive effort during error analysis affects strategy choice and success as measured by a series of online text production measures. We hypothesize that error correction with speech recognition software differs from error correction with keyboard for two reasons. Speech produces auditory commands and, consequently, different error types. The study reported on here measured the effects of (1 mode of presentation (auditory or visual-tactile, (2 error span, whether the error spans more or less than two characters, and (3 lexicality, whether the text error comprises an existing word. A multilevel analysis was conducted to take into account the hierarchical nature of these data. For each variable (interference reaction time, preparation time, production time, immediacy of error correction, and accuracy of error correction, multilevel regression models are presented. As such, we take into account possible disturbing person characteristics while testing the effect of the different conditions and error types at the sentence level.The results show that writers delay error correction more often when the TPSF is read out aloud first. The auditory property of speech seems to free resources for the primary task of writing, i.e. text production. Moreover, the results show that large errors in the TPSF require more cognitive effort, and are solved with a higher accuracy than small errors. The latter also holds for the correction of small errors that result in non-existing words.

  3. Harmonisation of agricultural accounting

    Directory of Open Access Journals (Sweden)

    Jaroslav Sedláček

    2007-01-01

    Full Text Available This paper deals with the accounting of the biological assets. There are described two approaches: Czech and international. The International Accounting Standards are emulative of more authentic presentment of economic processes in agricultural activities than Czech accounting legislation. From the comparison the both approaches accrued some differences, which can influent the financial statements of enterprises. The causation of main difference appears an application of fair value, which is prescribed for biological assets in international accounting standards. In international accounting standards is preferred principle of fair and true view, while in Czech accounting is preferred prudence principle.

  4. Switching Costs in Accounting Services

    Directory of Open Access Journals (Sweden)

    Fatih Koç

    2015-06-01

    Full Text Available Switching cost is defined as possible costs that customers may encounter when they want to change the firm they buy service, and an important subject in terms of accounting services. Particularly, small business entrepreneurs’ not having knowledge about accounting procedures, and sharing private information with accounting firms make switching costs more important for accounting services. Thus, the aim of this study is to investigate the concept of switching costs (relational cost, procedural cost and financial cost, its determinants (perceived service quality, service importance, and service failures, and consequences (re-purchasing, and recommen ding to others. Theresearch was conducted on small business entrepreneurs in down-town of Balıkesir in Turkey. Total 405 small business entrepreneur owners were interviewed. According to results of the study, perceived service quality positively affects all dimensions of switching costs, significance of service positively affects procedural and relational costs, and service failures negatively affect procedural and relational costs. The results showed that while procedural and relational costs positively affect re-purchasing and recommending to others variables, financial cost did not have any effect on these variables.

  5. Errors in Neonatology

    Directory of Open Access Journals (Sweden)

    Antonio Boldrini

    2013-06-01

    Full Text Available Introduction: Danger and errors are inherent in human activities. In medical practice errors can lean to adverse events for patients. Mass media echo the whole scenario. Methods: We reviewed recent published papers in PubMed database to focus on the evidence and management of errors in medical practice in general and in Neonatology in particular. We compared the results of the literature with our specific experience in Nina Simulation Centre (Pisa, Italy. Results: In Neonatology the main error domains are: medication and total parenteral nutrition, resuscitation and respiratory care, invasive procedures, nosocomial infections, patient identification, diagnostics. Risk factors include patients’ size, prematurity, vulnerability and underlying disease conditions but also multidisciplinary teams, working conditions providing fatigue, a large variety of treatment and investigative modalities needed. Discussion and Conclusions: In our opinion, it is hardly possible to change the human beings but it is likely possible to change the conditions under they work. Voluntary errors report systems can help in preventing adverse events. Education and re-training by means of simulation can be an effective strategy too. In Pisa (Italy Nina (ceNtro di FormazIone e SimulazioNe NeonAtale is a simulation center that offers the possibility of a continuous retraining for technical and non-technical skills to optimize neonatological care strategies. Furthermore, we have been working on a novel skill trainer for mechanical ventilation (MEchatronic REspiratory System SImulator for Neonatal Applications, MERESSINA. Finally, in our opinion national health policy indirectly influences risk for errors. Proceedings of the 9th International Workshop on Neonatology · Cagliari (Italy · October 23rd-26th, 2013 · Learned lessons, changing practice and cutting-edge research

  6. Error Free Software

    Science.gov (United States)

    1985-01-01

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

  7. LIBERTARISMO & ERROR CATEGORIAL

    Directory of Open Access Journals (Sweden)

    Carlos G. Patarroyo G.

    2009-01-01

    Full Text Available En este artículo se ofrece una defensa del libertarismo frente a dos acusaciones según las cuales éste comete un error categorial. Para ello, se utiliza la filosofía de Gilbert Ryle como herramienta para explicar las razones que fundamentan estas acusaciones y para mostrar por qué, pese a que ciertas versiones del libertarismo que acuden a la causalidad de agentes o al dualismo cartesiano cometen estos errores, un libertarismo que busque en el indeterminismo fisicalista la base de la posibilidad de la libertad humana no necesariamente puede ser acusado de incurrir en ellos.

  8. Quantification of errors in ordinal outcome scales using shannon entropy: effect on sample size calculations.

    Directory of Open Access Journals (Sweden)

    Pitchaiah Mandava

    Full Text Available OBJECTIVE: Clinical trial outcomes often involve an ordinal scale of subjective functional assessments but the optimal way to quantify results is not clear. In stroke, the most commonly used scale, the modified Rankin Score (mRS, a range of scores ("Shift" is proposed as superior to dichotomization because of greater information transfer. The influence of known uncertainties in mRS assessment has not been quantified. We hypothesized that errors caused by uncertainties could be quantified by applying information theory. Using Shannon's model, we quantified errors of the "Shift" compared to dichotomized outcomes using published distributions of mRS uncertainties and applied this model to clinical trials. METHODS: We identified 35 randomized stroke trials that met inclusion criteria. Each trial's mRS distribution was multiplied with the noise distribution from published mRS inter-rater variability to generate an error percentage for "shift" and dichotomized cut-points. For the SAINT I neuroprotectant trial, considered positive by "shift" mRS while the larger follow-up SAINT II trial was negative, we recalculated sample size required if classification uncertainty was taken into account. RESULTS: Considering the full mRS range, error rate was 26.1%±5.31 (Mean±SD. Error rates were lower for all dichotomizations tested using cut-points (e.g. mRS 1; 6.8%±2.89; overall p<0.001. Taking errors into account, SAINT I would have required 24% more subjects than were randomized. CONCLUSION: We show when uncertainty in assessments is considered, the lowest error rates are with dichotomization. While using the full range of mRS is conceptually appealing, a gain of information is counter-balanced by a decrease in reliability. The resultant errors need to be considered since sample size may otherwise be underestimated. In principle, we have outlined an approach to error estimation for any condition in which there are uncertainties in outcome assessment. We

  9. TIME MANAGEMENT FOR ACCOUNTANTS

    Directory of Open Access Journals (Sweden)

    Cristina Elena BIGIOI

    2016-06-01

    Full Text Available Time is money. Every accountant knows that. In our country, the taxes are changing frequently. The accountants have to update their fiscal knowledge. The purpose of the article is to find how the accountants manage their time, taking into consideration the number of fiscal declarations and the fiscal changes. In this article we present some ways to improve time management for accountants.

  10. Making Collaborative Innovation Accountable

    DEFF Research Database (Denmark)

    Sørensen, Eva

    The public sector is increasingly expected to be innovative, but the prize for a more innovative public sector might be that it becomes difficult to hold public authorities to account for their actions. The article explores the tensions between innovative and accountable governance, describes...... the foundation for these tensions in different accountability models, and suggest directions to take in analyzing the accountability of collaborative innovation processes....

  11. ACCOUNTING AUTOMATIONS RISKS

    OpenAIRE

    Муравський, В. В.; Хома, Н. Г.

    2015-01-01

    Accountant accepts active voice in organization of the automated account in the conditions of the informative systems introduction in enterprise activity. Effective accounting automation needs identification and warning of organizational risks. Authors researched, classified and generalized the risks of introduction of the informative accounting systems. The ways of liquidation of the organizational risks sources andminimization of their consequences are gives. The method of the effective con...

  12. 容积调强旋转放疗的计划验证通过率对多叶准直器位置误差的灵敏度%The sensitivity of patient-specific VMAT QA to MLC positioning errors

    Institute of Scientific and Technical Information of China (English)

    王清鑫; 戴建荣; 张可; 杨昕

    2013-01-01

    Objective To evaluate the sensitivity of patient-specific volumetric-modulated arc therapy (VMAT) quality assurance (QA) to minor multileaf collimator (M LC) positioning errors.Methods Systematic multileaf collimator (MLC) positioning errors (+0.5 mm,+ 1 mm and +2 mm) were introduced into the clinical VMAT patient plans with 2 types of MLC positioning errors:systematic MLC gap width errors and systematic MLC shift errors for 6 cases,including 3 cases with prostatic cancer and 3 cases with nasopharyngeal cancer.The planar dose distributions of the original and modified plans were measured using ArcCheck array.The coincidence between the measured results and the calculated results was evaluated using both absolute distance-to-agreement (AD-DTA) analysis with 3%/3 mm and 2%/2 mm criteria.Results The average passing rate of the 6 original VMAT plans was 96.0% with the ADDTA criteria of 3%/3 mm which was commonly adopted in clinical practice.For the MLC gap width errors of + 1 mm,+2 mm,and-2 mm and the MLC shift errors of 2 mm,the drop levels in average passing rate with the AD-DTA criteria of 3%/3 mm were 8.8%,15.5%,6.1% and 7.9%,respectively.The + 2 mm MLC positioning errors and + 1 mm MLC gap width errors could be detected by the patient-specific VMAT QA procedure.The AD-DTA criteria of 2%/2 mm was more sensitive compared with the criteria of 3%/3 mm.Conclusions Patient-specific VMAT QA is not sensitive enough to detect the systematic MLC positioning errors within 1 mm.Additional MLC QA is needed to guarantee the accuracy of VMAT delivery.%目的 针对容积调强旋转放疗技术(VMAT),分析患者计划验证通过率对多叶准直器(MLC)位置误差的灵敏度.方法 选取6例双弧VMAT计划,引入MLC位置误差(±0.5 mm、±1 mm和±2 mm),模拟VMAT执行过程中MLC可能出现的系统误差,包括MLC射野宽度误差和MLC整体偏向一侧的误差.每个病例有10个计划,1个原计划和9个带有误差的新计划.利用

  13. Contouring error compensation on a micro coordinate measuring machine

    Science.gov (United States)

    Fan, Kuang-Chao; Wang, Hung-Yu; Ye, Jyun-Kuan

    2011-12-01

    In recent years, three-dimensional measurements of nano-technology researches have received a great attention in the world. Based on the high accuracy demand, the error compensation of measurement machine is very important. In this study, a high precision Micro-CMM (coordinate measuring machine) has been developed which is composed of a coplanar stage for reducing the Abbé error in the vertical direction, the linear diffraction grating interferometer (LDGI) as the position feedback sensor in nanometer resolution, and ultrasonic motors for position control. This paper presents the error compensation strategy including "Home accuracy" and "Position accuracy" in both axes. For the home error compensation, we utilize a commercial DVD pick-up head and its S-curve principle to accurately search the origin of each axis. For the positioning error compensation, the absolute positions relative to the home are calibrated by laser interferometer and the error budget table is stored for feed forward error compensation. Contouring error can thus be compensated if both the compensation of both X and Y positioning errors are applied. Experiments show the contouring accuracy can be controlled to within 50nm after compensation.

  14. Cash Advance Accounting: Accounting Regulations and Practices

    Directory of Open Access Journals (Sweden)

    Aristita Rotila

    2012-12-01

    Full Text Available It is known the fact that often the entities offer to staff or third parties certain amounts of money, in order to make payments for the entities, such sums being registered differently in the accounting as cash advances. In the case in which the advances are offered in a foreign currency, there is the problem of the exchange rate used when justifying the advance, for the conversion in lei of payments that were carried out. In this article we wanted to signal the effect that the exchange rate, used in the assessment for reflecting in the accounting operations concerning cash advance reimbursements in a foreign currency, has on the information presented in the financial statement. Therewith, we signal some aspects from the content of the accounting regulations, with reference at defining the cash advances, meaning, and the presentation in the balance sheet of cash advances, which, in our opinion, impose clarifications.

  15. Avoiding and identifying errors in health technology assessment models: qualitative study and methodological review.

    Science.gov (United States)

    Chilcott, J; Tappenden, P; Rawdin, A; Johnson, M; Kaltenthaler, E; Paisley, S; Papaioannou, D; Shippam, A

    2010-05-01

    Health policy decisions must be relevant, evidence-based and transparent. Decision-analytic modelling supports this process but its role is reliant on its credibility. Errors in mathematical decision models or simulation exercises are unavoidable but little attention has been paid to processes in model development. Numerous error avoidance/identification strategies could be adopted but it is difficult to evaluate the merits of strategies for improving the credibility of models without first developing an understanding of error types and causes. The study aims to describe the current comprehension of errors in the HTA modelling community and generate a taxonomy of model errors. Four primary objectives are to: (1) describe the current understanding of errors in HTA modelling; (2) understand current processes applied by the technology assessment community for avoiding errors in development, debugging and critically appraising models for errors; (3) use HTA modellers' perceptions of model errors with the wider non-HTA literature to develop a taxonomy of model errors; and (4) explore potential methods and procedures to reduce the occurrence of errors in models. It also describes the model development process as perceived by practitioners working within the HTA community. A methodological review was undertaken using an iterative search methodology. Exploratory searches informed the scope of interviews; later searches focused on issues arising from the interviews. Searches were undertaken in February 2008 and January 2009. In-depth qualitative interviews were performed with 12 HTA modellers from academic and commercial modelling sectors. All qualitative data were analysed using the Framework approach. Descriptive and explanatory accounts were used to interrogate the data within and across themes and subthemes: organisation, roles and communication; the model development process; definition of error; types of model error; strategies for avoiding errors; strategies for

  16. PERCEPTION OF RADIOLOGISTS ABOUT DIAGNOSTIC ERRORS IN RADIOLOGY IN YEMEN

    Directory of Open Access Journals (Sweden)

    Hameed M Aklan

    2014-12-01

    Full Text Available Background: Errors of diagnosis in Radiology are common affecting patient’s care and management. Several types of radiological errors such as misperception, miscommunication, and procedure misconduct have been reported highlighting the important of Radiologists’ awareness about their own errors. However, no data are available from Yemen. The aim of this study is to assess radiological errors in Yemen. Method: A standard questionnaire of radiological errors was distributed conveniently to radiologists in the main public and private hospitals in Sana'a city, Yemen. Results: Of 80 questionnaires distributed, 58 were returned back (the response rate was 72.5%. About 88% participants had diagnostic errors in 2013. The radiology errors were classified as under-call (false negative (29.3%, communication errors (27.6%, overcall (false positive (25.9%, procedural complication (24.1% and interpretation errors (15.5%. Unavailability of previous studies and inadequate clinical information were mentioned as cause’s errors (37.9% and 36.2%, respectively. The majority of radiologists (70.7% did not keep record for their own errors, and only 24.1% of radiologists had errors meeting in their departments. Conclusion: It has been concluded that errors in radiology are still a significant problem affecting patient safety. Collaborative efforts must be established to reduce diagnostic errors in radiology through organizing regular meetings to educate radiologists about such matter and create a good environment for learning and improvement rather than blaming and embarrassing.

  17. The Accounting Capstone Problem

    Science.gov (United States)

    Elrod, Henry; Norris, J. T.

    2012-01-01

    Capstone courses in accounting programs bring students experiences integrating across the curriculum (University of Washington, 2005) and offer unique (Sanyal, 2003) and transformative experiences (Sill, Harward, & Cooper, 2009). Students take many accounting courses without preparing complete sets of financial statements. Accountants not only…

  18. Accounting Education in Crisis

    Science.gov (United States)

    Turner, Karen F.; Reed, Ronald O.; Greiman, Janel

    2011-01-01

    Almost on a daily basis new accounting rules and laws are put into use, creating information that must be known and learned by the accounting faculty and then introduced to and understood by the accounting student. Even with the 150 hours of education now required for CPA licensure, it is impossible to teach and learn all there is to learn. Over…

  19. Automated Accounting. Instructor Guide.

    Science.gov (United States)

    Moses, Duane R.

    This curriculum guide was developed to assist business instructors using Dac Easy Accounting College Edition Version 2.0 software in their accounting programs. The module consists of four units containing assignment sheets and job sheets designed to enable students to master competencies identified in the area of automated accounting. The first…

  20. Intelligent Accountability in Education

    Science.gov (United States)

    O'Neill, Onora

    2013-01-01

    Systems of accountability are "second order" ways of using evidence of the standard to which "first order" tasks are carried out for a great variety of purposes. However, more accountability is not always better, and processes of holding to account can impose high costs without securing substantial benefits. At their worst,…

  1. ACCOUNTING RESPONSIBILITY FOR BUSINESS EVALUATION

    Directory of Open Access Journals (Sweden)

    DORU CÎRNU

    2015-12-01

    Full Text Available In the world today the need for improvement the business management quality assumes significant change in organization and mode of business management. Establishing of appropriate level, structure and authority of business management depends in most cases on the size, number of employees, complexness of technological and business process, market position and other factors. Development of a business requires decentralization of operative functions. The decentralization of a business means the increase of operative activities control of greater number of managers in such a business. An important segment that so far was neither sufficiently applied in the romanian practice, not sufficiently treated is a system of responsibility. One of the aims of this research is also stimulation of more intensive activities on initiating the process of accounting modernisation. First of all, on the improvement and more rational legal accounting regulation and motivation of professional accountants organization for quicker development of contemporary accounting principles and standards in compliance with tendencies of the european environment. The known experiences just point to the necessity of more complex perception of place and role of the management accounting and within it of the system of accounting responsibility in preparing of business plans and buget, in creation of development and investment policy. Therefore, the system of accounting responsibility should eneble monitoring and control of actual operational activities of each part of decentralized business. The process of performance evaluation and accounting responsibility in a descentralized business organization represents a significant element of an internal control system and in that sense the emphasis was put on that fact in this paper.

  2. Open quantum systems and error correction

    Science.gov (United States)

    Shabani Barzegar, Alireza

    Quantum effects can be harnessed to manipulate information in a desired way. Quantum systems which are designed for this purpose are suffering from harming interaction with their surrounding environment or inaccuracy in control forces. Engineering different methods to combat errors in quantum devices are highly demanding. In this thesis, I focus on realistic formulations of quantum error correction methods. A realistic formulation is the one that incorporates experimental challenges. This thesis is presented in two sections of open quantum system and quantum error correction. Chapters 2 and 3 cover the material on open quantum system theory. It is essential to first study a noise process then to contemplate methods to cancel its effect. In the second chapter, I present the non-completely positive formulation of quantum maps. Most of these results are published in [Shabani and Lidar, 2009b,a], except a subsection on geometric characterization of positivity domain of a quantum map. The real-time formulation of the dynamics is the topic of the third chapter. After introducing the concept of Markovian regime, A new post-Markovian quantum master equation is derived, published in [Shabani and Lidar, 2005a]. The section of quantum error correction is presented in three chapters of 4, 5, 6 and 7. In chapter 4, we introduce a generalized theory of decoherence-free subspaces and subsystems (DFSs), which do not require accurate initialization (published in [Shabani and Lidar, 2005b]). In Chapter 5, we present a semidefinite program optimization approach to quantum error correction that yields codes and recovery procedures that are robust against significant variations in the noise channel. Our approach allows us to optimize the encoding, recovery, or both, and is amenable to approximations that significantly improve computational cost while retaining fidelity (see [Kosut et al., 2008] for a published version). Chapter 6 is devoted to a theory of quantum error correction (QEC

  3. Orwell's Instructive Errors

    Science.gov (United States)

    Julian, Liam

    2009-01-01

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

  4. Challenge and Error: Critical Events and Attention-Related Errors

    Science.gov (United States)

    Cheyne, James Allan; Carriere, Jonathan S. A.; Solman, Grayden J. F.; Smilek, Daniel

    2011-01-01

    Attention lapses resulting from reactivity to task challenges and their consequences constitute a pervasive factor affecting everyday performance errors and accidents. A bidirectional model of attention lapses (error [image omitted] attention-lapse: Cheyne, Solman, Carriere, & Smilek, 2009) argues that errors beget errors by generating attention…

  5. A statistical model for point-based target registration error with anisotropic fiducial localizer error.

    Science.gov (United States)

    Wiles, Andrew D; Likholyot, Alexander; Frantz, Donald D; Peters, Terry M

    2008-03-01

    Error models associated with point-based medical image registration problems were first introduced in the late 1990s. The concepts of fiducial localizer error, fiducial registration error, and target registration error are commonly used in the literature. The model for estimating the target registration error at a position r in a coordinate frame defined by a set of fiducial markers rigidly fixed relative to one another is ubiquitous in the medical imaging literature. The model has also been extended to simulate the target registration error at the point of interest in optically tracked tools. However, the model is limited to describing the error in situations where the fiducial localizer error is assumed to have an isotropic normal distribution in R3. In this work, the model is generalized to include a fiducial localizer error that has an anisotropic normal distribution. Similar to the previous models, the root mean square statistic rms tre is provided along with an extension that provides the covariance Sigma tre. The new model is verified using a Monte Carlo simulation and a set of statistical hypothesis tests. Finally, the differences between the two assumptions, isotropic and anisotropic, are discussed within the context of their use in 1) optical tool tracking simulation and 2) image registration.

  6. Differential effects of main error correction versus secondary error correction on motor pattern of running.

    Science.gov (United States)

    Corte, Stefano; Cavedon, Valentina; Milanese, Chiara

    2015-12-01

    The aim of this study was to gain a better understanding of how the run pattern varies as a consequence to main error correction versus secondary error correction. Twenty-two university students were randomly assigned to one of two training-conditions: 'main error' (ME) and 'secondary error' (SE) correction. The rear-foot strike at touchdown was hypothesized as the 'main error', whereas an incorrect shoulder position (i.e., behind the base of support) as the 'secondary error'. In order to evaluate any changes in run pattern at the foot touchdown instant, the ankle, knee and hip joint angles, the height of toe and heel (with respect to the ground), and the horizontal distance from the heel to the projected center of mass on the ground were measured. After the training-intervention, the ME group showed a significant improvement in the run pattern at the foot touchdown instant in all kinematic parameters, whereas no significant changes were found in the SE group. The results support the hypothesis that the main error can have a greater influence on the movement patterns than a secondary error. Furthermore, the findings highlight that a correct diagnosis and the correction of the 'main error' are fundamental for greater run pattern improvement.

  7. Systematic sampling with errors in sample locations

    DEFF Research Database (Denmark)

    Ziegel, Johanna; Baddeley, Adrian; Dorph-Petersen, Karl-Anton

    2010-01-01

    Systematic sampling of points in continuous space is widely used in microscopy and spatial surveys. Classical theory provides asymptotic expressions for the variance of estimators based on systematic sampling as the grid spacing decreases. However, the classical theory assumes that the sample grid...... is exactly periodic; real physical sampling procedures may introduce errors in the placement of the sample points. This paper studies the effect of errors in sample positioning on the variance of estimators in the case of one-dimensional systematic sampling. First we sketch a general approach to variance...... analysis using point process methods. We then analyze three different models for the error process, calculate exact expressions for the variances, and derive asymptotic variances. Errors in the placement of sample points can lead to substantial inflation of the variance, dampening of zitterbewegung...

  8. Errors in particle tracking velocimetry with high-speed cameras

    CERN Document Server

    Feng, Yan; Liu, Bin

    2011-01-01

    Velocity errors in particle tracking velocimetry (PTV) are studied. When using high-speed video cameras, the velocity error may increase at a high camera frame rate. This increase in velocity error is due to particle-position uncertainty, which is one of two sources of velocity errors studied here. The other source of error is particle acceleration, which has the opposite trend of diminishing at higher frame rates. Both kinds of errors can propagate into quantities calculated from velocity, such as the kinetic temperature of particles or correlation functions. As demonstrated in a dusty plasma experiment, the kinetic temperature of particles has no unique value when measured using PTV, but depends on the sampling time interval or frame rate. It is also shown that an artifact appears in an autocorrelation function computed from particle positions and velocities, and it becomes more severe when a small sampling-time interval is used. Schemes to reduce these errors are demonstrated.

  9. Analysis of Errors in a Special Perturbations Satellite Orbit Propagator

    Energy Technology Data Exchange (ETDEWEB)

    Beckerman, M.; Jones, J.P.

    1999-02-01

    We performed an analysis of error densities for the Special Perturbations orbit propagator using data for 29 satellites in orbits of interest to Space Shuttle and International Space Station collision avoidance. We find that the along-track errors predominate. These errors increase monotonically over each 36-hour prediction interval. The predicted positions in the along-track direction progressively either leap ahead of or lag behind the actual positions. Unlike the along-track errors the radial and cross-track errors oscillate about their nearly zero mean values. As the number of observations per fit interval decline the along-track prediction errors, and amplitudes of the radial and cross-track errors, increase.

  10. The Responsibilities of Accountants

    OpenAIRE

    Ronald F Duska

    2005-01-01

    An accountant is a good accountant if in practicing his craft he is superb in handling the numbers. But a good accountant in handling the numbers can use that skill to misstate earnings to cover a multitude of problems with a company's books while staying within the law. So, the notion of a moral or ethical accountant is not the same as the notion of a good accountant. Our general principle would be that to be ethical a person has a responsibility to fulfil one's role or roles, as long as tha...

  11. Statistical error analysis of reactivity measurement

    Energy Technology Data Exchange (ETDEWEB)

    Thammaluckan, Sithisak; Hah, Chang Joo [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    After statistical analysis, it was confirmed that each group were sampled from same population. It is observed in Table 7 that the mean error decreases as core size increases. Application of bias factor obtained from this research reduces mean error further. The point kinetic model had been used to measure control rod worth without 3D spatial information of neutron flux or power distribution, which causes inaccurate result. Dynamic Control rod Reactivity Measurement (DCRM) was employed to take into account of 3D spatial information of flux in the point kinetics model. The measured bank worth probably contains some uncertainty such as methodology uncertainty and measurement uncertainty. Those uncertainties may varies with size of core and magnitude of reactivity. The goal of this research is to investigate the effect of core size and magnitude of control rod worth on the error of reactivity measurement using statistics.

  12. Error Analysis for High Resolution Topography with Bi-Static Single-Pass SAR Interferometry

    Science.gov (United States)

    Muellerschoen, Ronald J.; Chen, Curtis W.; Hensley, Scott; Rodriguez, Ernesto

    2006-01-01

    We present a flow down error analysis from the radar system to topographic height errors for bi-static single pass SAR interferometry for a satellite tandem pair. Because of orbital dynamics the baseline length and baseline orientation evolve spatially and temporally, the height accuracy of the system is modeled as a function of the spacecraft position and ground location. Vector sensitivity equations of height and the planar error components due to metrology, media effects, and radar system errors are derived and evaluated globally for a baseline mission. Included in the model are terrain effects that contribute to layover and shadow and slope effects on height errors. The analysis also accounts for nonoverlapping spectra and the non-overlapping bandwidth due to differences between the two platforms' viewing geometries. The model is applied to a 514 km altitude 97.4 degree inclination tandem satellite mission with a 300 m baseline separation and X-band SAR. Results from our model indicate that global DTED level 3 can be achieved.

  13. Implications of Fraud and Error Risks in the Enterprise Environment and Auditor’s Work

    Directory of Open Access Journals (Sweden)

    Emil Horomnea

    2012-05-01

    Full Text Available The objective of this study is to identify and analyze the main correlations and implications offraud and error in the business environment and in the financial scandals occurred in the last decade. Theapproach envisages a synthesis and antithesis of the ideas found on this subject in the specialty literature, ofthe regulations issued by various international bodies. To achieve the established objectives, we used aconstructive methodology to identify criticism, presentations and developed a speech with view to a moreefficient and effective fraud and error risk management. The results of the study show that the major financialscandals and hence the global economic crisis are based largely on fraudulent maneuvers of significantproportions. By using "creative accounting" in fraud and error, famous companies have managed to distortreality for their performance and market position, misleading the users’ perception. This study is a theoreticalhaving implications for a future empirical study.The study contributes to auditing literature diversification inthe field of risk of fraud and error. An additional perspective is gained by addressing the financial crisis andsome famous bankruptcies by way of the financial auditors activity and the fraud and error risk.

  14. Accounting: "Balancing Out" the Accounting Program.

    Science.gov (United States)

    Babcock, Coleen

    1979-01-01

    The vocational accounting laboratory is a viable, meaningful educational experience for high school seniors, due to the uniqueness of its educational approach and the direct involvement of the professional and business community. A balance of experiences is provided to match individual needs and goals of students. (CT)

  15. ACCOUNTING ASPECTS OF PRICING AND TRANSFER PRICING

    Directory of Open Access Journals (Sweden)

    TÜNDE VERES

    2011-01-01

    Full Text Available The pricing methods in practice need really complex view of the business situation and depend on the strategy and market position of a company. The structure of a price seems simple: cost plus margin. Both categories are special area in the management accounting. Information about the product costs, the allocation methodologies in cost accounting, the analyzing of revenue and different level of the margin needs information from accounting system. This paper analyzes the pricing methods from management accounting aspects to show out the role of the accounting system in the short term and long term pricing and transfer pricing decisions.

  16. PARADIGM OF ACCOUNTING CHANGE

    Directory of Open Access Journals (Sweden)

    Constanta Iacob

    2016-12-01

    Full Text Available The words and phrases swop with each other and the apparent stability of a word’s meaning sometimes change in time. This explains why the generic term of accounting is used when referring to the qualities attributed to accounting,but also when it comes to organizing financial accounting function within the entity, and when referring concretely to keeping a double record with its specific means, methods and tools specific, respectively seen as a technical accounting.Speaking about the qualities of accounting, but also about the organizational form it takes, we note that there is a manifold meaning of the word accounting, which is why the purpose of this article is to demonstrate that the paradigm shift aimed at a new set of rules and if the rules changes, then we can change the very purpose of accounting.

  17. Visuomotor adaptation needs a validation of prediction error by feedback error

    Directory of Open Access Journals (Sweden)

    Valérie eGaveau

    2014-11-01

    Full Text Available The processes underlying short-term plasticity induced by visuomotor adaptation to a shifted visual field are still debated. Two main sources of error can induce motor adaptation: reaching feedback errors, which correspond to visually perceived discrepancies between hand and target positions, and errors between predicted and actual visual reafferences of the moving hand. These two sources of error are closely intertwined and difficult to disentangle, as both the target and the reaching limb are simultaneously visible. Accordingly, the goal of the present study was to clarify the relative contributions of these two types of errors during a pointing task under prism-displaced vision. In ‘terminal feedback error’ condition, viewing of their hand by subjects was allowed only at movement end, simultaneously with viewing of the target. In ‘movement prediction error’ condition, viewing of the hand was limited to movement duration, in the absence of any visual target, and error signals arose solely from comparisons between predicted and actual reafferences of the hand. In order to prevent intentional corrections of errors, a subthreshold, progressive stepwise increase in prism deviation was used, so that subjects remained unaware of the visual deviation applied in both conditions. An adaptive aftereffect was observed in the ‘terminal feedback error’ condition only. As far as subjects remained unaware of the optical deviation and self-assigned pointing errors, prediction error alone was insufficient to induce adaptation. These results indicate a critical role of hand-to-target feedback error signals in visuomotor adaptation; consistent with recent neurophysiological findings, they suggest that a combination of feedback and prediction error signals is necessary for eliciting aftereffects. They also suggest that feedback error updates the prediction of reafferences when a visual perturbation is introduced gradually and cognitive factors are

  18. Women Accountants in Practicing Accounting Firms: Their Status, Investments and Returns

    Science.gov (United States)

    Okpechi, Simeon O.; Belmasrour, Rachid

    2011-01-01

    In the past twenty years, the number of qualified women accountants in the U.S. has outstripped that of men according to American Institute of Certified Public Accountants; yet these women occupy few strategic positions in accounting firms. Retention has been a major issue. This study explores how the perception of their status, investments and…

  19. Logical error rate in the Pauli twirling approximation.

    Science.gov (United States)

    Katabarwa, Amara; Geller, Michael R

    2015-09-30

    The performance of error correction protocols are necessary for understanding the operation of potential quantum computers, but this requires physical error models that can be simulated efficiently with classical computers. The Gottesmann-Knill theorem guarantees a class of such error models. Of these, one of the simplest is the Pauli twirling approximation (PTA), which is obtained by twirling an arbitrary completely positive error channel over the Pauli basis, resulting in a Pauli channel. In this work, we test the PTA's accuracy at predicting the logical error rate by simulating the 5-qubit code using a 9-qubit circuit with realistic decoherence and unitary gate errors. We find evidence for good agreement with exact simulation, with the PTA overestimating the logical error rate by a factor of 2 to 3. Our results suggest that the PTA is a reliable predictor of the logical error rate, at least for low-distance codes.

  20. Modeling Approach of Regression Orthogonal Experiment Design for Thermal Error Compensation of CNC Turning Center

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The thermal induced errors can account for as much as 70% of the dimensional errors on a workpiece. Accurate modeling of errors is an essential part of error compensation. Base on analyzing the existing approaches of the thermal error modeling for machine tools, a new approach of regression orthogonal design is proposed, which combines the statistic theory with machine structures, surrounding condition, engineering judgements, and experience in modeling. A whole computation and analysis procedure is given. ...

  1. Patient error: a preliminary taxonomy.

    NARCIS (Netherlands)

    Buetow, S.; Kiata, L.; Liew, T.; Kenealy, T.; Dovey, S.; Elwyn, G.

    2009-01-01

    PURPOSE: Current research on errors in health care focuses almost exclusively on system and clinician error. It tends to exclude how patients may create errors that influence their health. We aimed to identify the types of errors that patients can contribute and help manage, especially in primary ca

  2. Automatic Error Analysis Using Intervals

    Science.gov (United States)

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

    2012-01-01

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

  3. Imagery of Errors in Typing

    Science.gov (United States)

    Rieger, Martina; Martinez, Fanny; Wenke, Dorit

    2011-01-01

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

  4. Numerical simulation of spatial whole-body vibration behaviour of sitting man taking into account individual anthropometry and position; Numerische Simulation des raeumlichen Ganzkoerperschwingungsverhaltens des sitzenden Menschen unter Beruecksichtigung der individuellen Anthropometrie und Haltung

    Energy Technology Data Exchange (ETDEWEB)

    Pankoke, S.

    2003-07-01

    A dynamic FE model of the anatomy of humans in sitting position is presented for assessing the dynamic internal response of the human body to the effect of external vibrations. The model can be adapted to individual body measures, different positions and different spatial orientation. It was verified on the basis of extensive measured data. The problem of contact between the human body and the driver seat is solved by a simplified static description. The model comprises a sub-model of the lumbar vertebral column for assessing the spatial load distributions in this body region. [German] In der vorliegenden Arbeit wird ein dynamisches, an der menschlichen Anatomie orientiertes Finite-Elemente-Modell des sitzenden Menschen vorgestellt, das es gestaltet, dynamische innere Antworten des Koerpers auf von aussen auf den Menschen einwirkende Schwingungen zu ermitteln. Das Modell ist ueber eine Auswahl anthropometrischer Masse an das Schwingungsverhalten eines Individuums anpassbar und ermoeglicht zudem die Simulation von Schwingungseinwirkungen in unterschiedlichen Haltungen und in allen Raumrichtungen. Die Modellverifikation erfolgte an umfangreichen Messdatenbestaenden. Das Kontaktproblem des Menschen zum Fahrzeugsitz ist durch eine vereinfachte statische Beschreibung abgebildet. Ferner beinhaltet das Ganzkoerpermodell ein Submodell der Lendenwirbelsaeule, mit dessen Hilfe die aus den Ganzkoerperschwingungen folgenden raeumlichen Beanspruchungsverteilungen in der Lendenwirbelsaeule ermittelt werden koennen. (orig.)

  5. Error bars in experimental biology.

    Science.gov (United States)

    Cumming, Geoff; Fidler, Fiona; Vaux, David L

    2007-04-09

    Error bars commonly appear in figures in publications, but experimental biologists are often unsure how they should be used and interpreted. In this article we illustrate some basic features of error bars and explain how they can help communicate data and assist correct interpretation. Error bars may show confidence intervals, standard errors, standard deviations, or other quantities. Different types of error bars give quite different information, and so figure legends must make clear what error bars represent. We suggest eight simple rules to assist with effective use and interpretation of error bars.

  6. Video Error Correction Using Steganography

    Directory of Open Access Journals (Sweden)

    Robie David L

    2002-01-01

    Full Text Available The transmission of any data is always subject to corruption due to errors, but video transmission, because of its real time nature must deal with these errors without retransmission of the corrupted data. The error can be handled using forward error correction in the encoder or error concealment techniques in the decoder. This MPEG-2 compliant codec uses data hiding to transmit error correction information and several error concealment techniques in the decoder. The decoder resynchronizes more quickly with fewer errors than traditional resynchronization techniques. It also allows for perfect recovery of differentially encoded DCT-DC components and motion vectors. This provides for a much higher quality picture in an error-prone environment while creating an almost imperceptible degradation of the picture in an error-free environment.

  7. CONSTRUCTING ACCOUNTING UNCERTAINITY ESTIMATES VARIABLE

    Directory of Open Access Journals (Sweden)

    Nino Serdarevic

    2012-10-01

    Full Text Available This paper presents research results on the BIH firms’ financial reporting quality, utilizing empirical relation between accounting conservatism, generated in created critical accounting policy choices, and management abilities in estimates and prediction power of domicile private sector accounting. Primary research is conducted based on firms’ financial statements, constructing CAPCBIH (Critical Accounting Policy Choices relevant in B&H variable that presents particular internal control system and risk assessment; and that influences financial reporting positions in accordance with specific business environment. I argue that firms’ management possesses no relevant capacity to determine risks and true consumption of economic benefits, leading to creation of hidden reserves in inventories and accounts payable; and latent losses for bad debt and assets revaluations. I draw special attention to recent IFRS convergences to US GAAP, especially in harmonizing with FAS 130 Reporting comprehensive income (in revised IAS 1 and FAS 157 Fair value measurement. CAPCBIH variable, resulted in very poor performance, presents considerable lack of recognizing environment specifics. Furthermore, I underline the importance of revised ISAE and re-enforced role of auditors in assessing relevance of management estimates.

  8. Error-Free Software

    Science.gov (United States)

    1989-01-01

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

  9. A Characterization of Prediction Errors

    OpenAIRE

    Meek, Christopher

    2016-01-01

    Understanding prediction errors and determining how to fix them is critical to building effective predictive systems. In this paper, we delineate four types of prediction errors and demonstrate that these four types characterize all prediction errors. In addition, we describe potential remedies and tools that can be used to reduce the uncertainty when trying to determine the source of a prediction error and when trying to take action to remove a prediction errors.

  10. Error Analysis and Its Implication

    Institute of Scientific and Technical Information of China (English)

    崔蕾

    2007-01-01

    Error analysis is the important theory and approach for exploring the mental process of language learner in SLA. Its major contribution is pointing out that intralingual errors are the main reason of the errors during language learning. Researchers' exploration and description of the errors will not only promote the bidirectional study of Error Analysis as both theory and approach, but also give the implication to second language learning.

  11. Error bars in experimental biology

    OpenAIRE

    2007-01-01

    Error bars commonly appear in figures in publications, but experimental biologists are often unsure how they should be used and interpreted. In this article we illustrate some basic features of error bars and explain how they can help communicate data and assist correct interpretation. Error bars may show confidence intervals, standard errors, standard deviations, or other quantities. Different types of error bars give quite different information, and so figure legends must make clear what er...

  12. Regression Model With Elliptically Contoured Errors

    CERN Document Server

    Arashi, M; Tabatabaey, S M M

    2012-01-01

    For the regression model where the errors follow the elliptically contoured distribution (ECD), we consider the least squares (LS), restricted LS (RLS), preliminary test (PT), Stein-type shrinkage (S) and positive-rule shrinkage (PRS) estimators for the regression parameters. We compare the quadratic risks of the estimators to determine the relative dominance properties of the five estimators.

  13. Emerging accounting trends accounting for leases.

    Science.gov (United States)

    Valletta, Robert; Huggins, Brian

    2010-12-01

    A new model for lease accounting can have a significant impact on hospitals and healthcare organizations. The new approach proposes a "right-of-use" model that involves complex estimates and significant administrative burden. Hospitals and health systems that draw heavily on lease arrangements should start preparing for the new approach now even though guidance and a final rule are not expected until mid-2011. This article highlights a number of considerations from the lessee point of view.

  14. The image of accountants

    DEFF Research Database (Denmark)

    Baldvinsdottir, Gudrun; Burns, John; Nørreklit, Hanne

    2009-01-01

    , and whether the image produced reflects a wide social change in society. Findings - It was found that in the 1970s and the 1980s the accountant was constructed as a responsible and rational person. In the 1990s, the accountant was presented as an instructed action man. However, in a recent advert...... the accountant appeared as a more hedonistic person. Overall, the changes observed reflect changes in wider social practice from modernity, through high modernity, to hyper-modernity. Research limitations/implications - The image of the accountants has implications for the development of the accounting...... profession. In particular, the move towards hyper-modernity, where empathy towards others and the virtues of self-discipline and fairness are not at stake, has implications for the trustworthiness of the accounting profession. Originality/value - Although there has been some research into the image...

  15. Accounting for Quality

    DEFF Research Database (Denmark)

    Pflueger, Dane

    2015-01-01

    Background Accounting-that is, standardized measurement, public reporting, performance evaluation and managerial control-is commonly seen to provide the core infrastructure for quality improvement in healthcare. Yet, accounting successfully for quality has been a problematic endeavor, often......, but that it would need to be understood and operationalized in new ways in order to contribute to this end. Proposals for this new way of advancing accounting are discussed. They include the cultivation of overlapping and even conflicting measures of quality, the evaluation of accounting regimes in terms of what...... producing dysfunctional effects. This has raised questions about the appropriate role for accounting in achieving quality improvement. This paper contributes to this debate by contrasting the specific way in which accounting is understood and operationalized for quality improvement in the UK National Health...

  16. Goals and Psychological Accounting

    DEFF Research Database (Denmark)

    Koch, Alexander Karl; Nafziger, Julia

    -induced reference points make substandard performance psychologically painful and motivate the individual to stick to his goals. How strong the commitment to goals is depends on the type of psychological account. We provide conditions when it is optimal to evaluate goals in narrow accounts. The key intuition......We model how people formulate and evaluate goals to overcome self-control problems. People often attempt to regulate their behavior by evaluating goal-related outcomes separately (in narrow psychological accounts) rather than jointly (in a broad account). To explain this evidence, our theory...... of endogenous narrow or broad psychological accounts combines insights from the literatures on goals and mental accounting with models of expectations-based reference-dependent preferences. By formulating goals the individual creates expectations that induce reference points for task outcomes. These goal...

  17. Using lexical variables to predict picture-naming errors in jargon aphasia

    Directory of Open Access Journals (Sweden)

    Catherine Godbold

    2015-04-01

    Full Text Available Introduction Individuals with jargon aphasia produce fluent output which often comprises high proportions of non-word errors (e.g., maf for dog. Research has been devoted to identifying the underlying mechanisms behind such output. Some accounts posit a reduced flow of spreading activation between levels in the lexical network (e.g., Robson et al., 2003. If activation level differences across the lexical network are a cause of non-word outputs, we would predict improved performance when target items reflect an increased flow of activation between levels (e.g. more frequently-used words are often represented by higher resting levels of activation. This research investigates the effect of lexical properties of targets (e.g., frequency, imageability on accuracy, error type (real word vs. non-word and target-error overlap of non-word errors in a picture naming task by individuals with jargon aphasia. Method Participants were 17 individuals with Wernicke’s aphasia, who produced a high proportion of non-word errors (>20% of errors on the Philadelphia Naming Test (PNT; Roach et al., 1996. The data were retrieved from the Moss Aphasic Psycholinguistic Database Project (MAPPD, Mirman et al., 2010. We used a series of mixed models to test whether lexical variables predicted accuracy, error type (real word vs. non-word and target-error overlap for the PNT data. As lexical variables tend to be highly correlated, we performed a principal components analysis to reduce the variables into five components representing variables associated with phonology (length, phonotactic probability, neighbourhood density and neighbourhood frequency, semantics (imageability and concreteness, usage (frequency and age-of-acquisition, name agreement and visual complexity. Results and Discussion Table 1 shows the components that made a significant contribution to each model. Individuals with jargon aphasia produced more correct responses and fewer non-word errors relative to

  18. The modulating effect of personality traits on neural error monitoring: evidence from event-related FMRI.

    Directory of Open Access Journals (Sweden)

    Zrinka Sosic-Vasic

    Full Text Available The present study investigated the association between traits of the Five Factor Model of Personality (Neuroticism, Extraversion, Openness for Experiences, Agreeableness, and Conscientiousness and neural correlates of error monitoring obtained from a combined Eriksen-Flanker-Go/NoGo task during event-related functional magnetic resonance imaging in 27 healthy subjects. Individual expressions of personality traits were measured using the NEO-PI-R questionnaire. Conscientiousness correlated positively with error signaling in the left inferior frontal gyrus and adjacent anterior insula (IFG/aI. A second strong positive correlation was observed in the anterior cingulate gyrus (ACC. Neuroticism was negatively correlated with error signaling in the inferior frontal cortex possibly reflecting the negative inter-correlation between both scales observed on the behavioral level. Under present statistical thresholds no significant results were obtained for remaining scales. Aligning the personality trait of Conscientiousness with task accomplishment striving behavior the correlation in the left IFG/aI possibly reflects an inter-individually different involvement whenever task-set related memory representations are violated by the occurrence of errors. The strong correlations in the ACC may indicate that more conscientious subjects were stronger affected by these violations of a given task-set expressed by individually different, negatively valenced signals conveyed by the ACC upon occurrence of an error. Present results illustrate that for predicting individual responses to errors underlying personality traits should be taken into account and also lend external validity to the personality trait approach suggesting that personality constructs do reflect more than mere descriptive taxonomies.

  19. The modulating effect of personality traits on neural error monitoring: evidence from event-related FMRI.

    Science.gov (United States)

    Sosic-Vasic, Zrinka; Ulrich, Martin; Ruchsow, Martin; Vasic, Nenad; Grön, Georg

    2012-01-01

    The present study investigated the association between traits of the Five Factor Model of Personality (Neuroticism, Extraversion, Openness for Experiences, Agreeableness, and Conscientiousness) and neural correlates of error monitoring obtained from a combined Eriksen-Flanker-Go/NoGo task during event-related functional magnetic resonance imaging in 27 healthy subjects. Individual expressions of personality traits were measured using the NEO-PI-R questionnaire. Conscientiousness correlated positively with error signaling in the left inferior frontal gyrus and adjacent anterior insula (IFG/aI). A second strong positive correlation was observed in the anterior cingulate gyrus (ACC). Neuroticism was negatively correlated with error signaling in the inferior frontal cortex possibly reflecting the negative inter-correlation between both scales observed on the behavioral level. Under present statistical thresholds no significant results were obtained for remaining scales. Aligning the personality trait of Conscientiousness with task accomplishment striving behavior the correlation in the left IFG/aI possibly reflects an inter-individually different involvement whenever task-set related memory representations are violated by the occurrence of errors. The strong correlations in the ACC may indicate that more conscientious subjects were stronger affected by these violations of a given task-set expressed by individually different, negatively valenced signals conveyed by the ACC upon occurrence of an error. Present results illustrate that for predicting individual responses to errors underlying personality traits should be taken into account and also lend external validity to the personality trait approach suggesting that personality constructs do reflect more than mere descriptive taxonomies.

  20. Forecast errors in IEA-countries' energy consumption

    DEFF Research Database (Denmark)

    Linderoth, Hans

    2002-01-01

    Every year Policy of IEA Countries includes a forecast of the energy consumption in the member countries. Forecasts concerning the years 1985,1990 and 1995 can now be compared to actual values. The second oil crisis resulted in big positive forecast errors. The oil price drop in 1986 did not have...... the small value is often the sum of large positive and negative errors. Almost no significant correlation is found between forecast errors in the 3 years. Correspondingly, no significant correlation coefficient is found between forecasts errors in the 3 main energy sectors. Therefore, a relatively small...

  1. Perfect error processing: Perfectionism-related variations in action monitoring and error processing mechanisms.

    Science.gov (United States)

    Stahl, Jutta; Acharki, Manuela; Kresimon, Miriam; Völler, Frederike; Gibbons, Henning

    2015-08-01

    Showing excellent performance and avoiding poor performance are the main characteristics of perfectionists. Perfectionism-related variations (N=94) in neural correlates of performance monitoring were investigated in a flanker task by assessing two perfectionism-related trait dimensions: Personal standard perfectionism (PSP), reflecting intrinsic motivation to show error-free performance, and evaluative concern perfectionism (ECP), representing the worry of being poorly evaluated based on bad performance. A moderating effect of ECP and PSP on error processing - an important performance monitoring system - was investigated by examining the error (-related) negativity (Ne/ERN) and the error positivity (Pe). The smallest Ne/ERN difference (error-correct) was obtained for pure-ECP participants (high-ECP-low-PSP), whereas the highest difference was shown for those with high-ECP-high-PSP (i.e., mixed perfectionists). Pe was positively correlated with PSP only. Our results encouraged the cognitive-bias hypothesis suggesting that pure-ECP participants reduce response-related attention to avoid intense error processing by minimising the subjective threat of negative evaluations. The PSP-related variations in late error processing are consistent with the participants' high in PSP goal-oriented tendency to optimise their behaviour.

  2. Evaluation of statistical models for forecast errors from the HBV model

    Science.gov (United States)

    Engeland, Kolbjørn; Renard, Benjamin; Steinsland, Ingelin; Kolberg, Sjur

    2010-04-01

    SummaryThree statistical models for the forecast errors for inflow into the Langvatn reservoir in Northern Norway have been constructed and tested according to the agreement between (i) the forecast distribution and the observations and (ii) median values of the forecast distribution and the observations. For the first model observed and forecasted inflows were transformed by the Box-Cox transformation before a first order auto-regressive model was constructed for the forecast errors. The parameters were conditioned on weather classes. In the second model the Normal Quantile Transformation (NQT) was applied on observed and forecasted inflows before a similar first order auto-regressive model was constructed for the forecast errors. For the third model positive and negative errors were modeled separately. The errors were first NQT-transformed before conditioning the mean error values on climate, forecasted inflow and yesterday's error. To test the three models we applied three criterions: we wanted (a) the forecast distribution to be reliable; (b) the forecast intervals to be narrow; (c) the median values of the forecast distribution to be close to the observed values. Models 1 and 2 gave almost identical results. The median values improved the forecast with Nash-Sutcliffe R eff increasing from 0.77 for the original forecast to 0.87 for the corrected forecasts. Models 1 and 2 over-estimated the forecast intervals but gave the narrowest intervals. Their main drawback was that the distributions are less reliable than Model 3. For Model 3 the median values did not fit well since the auto-correlation was not accounted for. Since Model 3 did not benefit from the potential variance reduction that lies in bias estimation and removal it gave on average wider forecasts intervals than the two other models. At the same time Model 3 on average slightly under-estimated the forecast intervals, probably explained by the use of average measures to evaluate the fit.

  3. SIMULATION OF INERTIAL NAVIGATION SYSTEM ERRORS AT AERIAL PHOTOGRAPHY FROM UAV

    Directory of Open Access Journals (Sweden)

    R. Shults

    2017-05-01

    Full Text Available The problem of accuracy determination of the UAV position using INS at aerial photography can be resolved in two different ways: modelling of measurement errors or in-field calibration for INS. The paper presents the results of INS errors research by mathematical modelling. In paper were considered the following steps: developing of INS computer model; carrying out INS simulation; using reference data without errors, estimation of errors and their influence on maps creation accuracy by UAV data. It must be remembered that the values of orientation angles and the coordinates of the projection centre may change abruptly due to the influence of the atmosphere (different air density, wind, etc.. Therefore, the mathematical model of the INS was constructed taking into account the use of different models of wind gusts. For simulation were used typical characteristics of micro electromechanical (MEMS INS and parameters of standard atmosphere. According to the simulation established domination of INS systematic errors that accumulate during the execution of photographing and require compensation mechanism, especially for orientation angles. MEMS INS have a high level of noise at the system input. Thanks to the developed model, we are able to investigate separately the impact of noise in the absence of systematic errors. According to the research was found that on the interval of observations in 5 seconds the impact of random and systematic component is almost the same. The developed model of INS errors studies was implemented in Matlab software environment and without problems can be improved and enhanced with new blocks.

  4. The Accountability Bind

    Directory of Open Access Journals (Sweden)

    Katrina Bulkley

    2001-10-01

    Full Text Available Charter schools involve a trading of autonomy for accountability. This accountability comes through two forces—markets through the choices of parents and students, and accountability to government through the writing of contracts that must be renewed for schools to continue to operate. Charter schools are supposed to be more accountable for educational performance than traditional public schools because authorizers have the ability to revoke charter contracts. Here, I focus on one central component of accountability to government: performance accountability or accountability for educational outcomes to charter school authorizers through the revocation or non-renewal of charter contracts. In this paper, I suggest that contract-based accountability for educational performance in charter schools may not be working as proponents argued it would. This article explores some explanations for why there are very few examples of charter schools that have been closed primarily because of failure to demonstrate educational performance or improvement. Future work will need to test if these challenges for authorizers hold in a variety of contexts. The conclusion examines the implications of these findings for the future of charter school accountability.

  5. ACCOUNTING ASPECTS OF PRICING AND TRANSFER PRICING

    OpenAIRE

    TÜNDE VERES

    2011-01-01

    The pricing methods in practice need really complex view of the business situation and depend on the strategy and market position of a company. The structure of a price seems simple: cost plus margin. Both categories are special area in the management accounting. Information about the product costs, the allocation methodologies in cost accounting, the analyzing of revenue and different level of the margin needs information from accounting system. This paper analyzes the pricing methods from m...

  6. Accounting Aspects of Pricing and Transfer Pricing

    OpenAIRE

    TÜNDE VERES

    2011-01-01

    The pricing methods in practice need really complex view of the business situation and depend on the strategy and market position of a company. The structure of a price seems simple: cost plus margin. Both categories are special area in the management accounting. Information about the product costs, the allocation methodologies in cost accounting, the analyzing of revenue and different level of the margin needs information from accounting system. This paper analyzes the pricing methods from m...

  7. Subaperture test of wavefront error of large telescopes: error sources and stitching performance simulations

    Science.gov (United States)

    Chen, Shanyong; Li, Shengyi; Wang, Guilin

    2014-11-01

    The wavefront error of large telescopes requires to be measured to check the system quality and also estimate the misalignment of the telescope optics including the primary, the secondary and so on. It is usually realized by a focal plane interferometer and an autocollimator flat (ACF) of the same aperture with the telescope. However, it is challenging for meter class telescopes due to high cost and technological challenges in producing the large ACF. Subaperture test with a smaller ACF is hence proposed in combination with advanced stitching algorithms. Major error sources include the surface error of the ACF, misalignment of the ACF and measurement noises. Different error sources have different impacts on the wavefront error. Basically the surface error of the ACF behaves like systematic error and the astigmatism will be cumulated and enlarged if the azimuth of subapertures remains fixed. It is difficult to accurately calibrate the ACF because it suffers considerable deformation induced by gravity or mechanical clamping force. Therefore a selfcalibrated stitching algorithm is employed to separate the ACF surface error from the subaperture wavefront error. We suggest the ACF be rotated around the optical axis of the telescope for subaperture test. The algorithm is also able to correct the subaperture tip-tilt based on the overlapping consistency. Since all subaperture measurements are obtained in the same imaging plane, lateral shift of the subapertures is always known and the real overlapping points can be recognized in this plane. Therefore lateral positioning error of subapertures has no impact on the stitched wavefront. In contrast, the angular positioning error changes the azimuth of the ACF and finally changes the systematic error. We propose an angularly uneven layout of subapertures to minimize the stitching error, which is very different from our knowledge. At last, measurement noises could never be corrected but be suppressed by means of averaging and

  8. Comparison of accounting methods for business combinations

    Directory of Open Access Journals (Sweden)

    Jaroslav Sedláček

    2012-01-01

    Full Text Available The revised accounting rules applicable to business combinations in force on July1st 2009, are the result of several years efforts the convergence of U.S. and International Committee of the Financial Accounting Standards. Following the harmonization of global accounting procedures are revised and implemented also Czech accounting regulations. In our research we wanted to see how changes can affect the strategy and timing of business combinations. Comparative analysis is mainly focused on the differences between U.S. and international accounting policies and Czech accounting regulations. Key areas of analysis and synthesis are the identification of business combination, accounting methods for business combinations and goodwill recognition. The result is to assess the impact of the identified differences in the reported financial position and profit or loss of company.

  9. Diagnostic errors in pediatric radiology

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, George A.; Voss, Stephan D. [Children' s Hospital Boston, Department of Radiology, Harvard Medical School, Boston, MA (United States); Melvin, Patrice R. [Children' s Hospital Boston, The Program for Patient Safety and Quality, Boston, MA (United States); Graham, Dionne A. [Children' s Hospital Boston, The Program for Patient Safety and Quality, Boston, MA (United States); Harvard Medical School, The Department of Pediatrics, Boston, MA (United States)

    2011-03-15

    Little information is known about the frequency, types and causes of diagnostic errors in imaging children. Our goals were to describe the patterns and potential etiologies of diagnostic error in our subspecialty. We reviewed 265 cases with clinically significant diagnostic errors identified during a 10-year period. Errors were defined as a diagnosis that was delayed, wrong or missed; they were classified as perceptual, cognitive, system-related or unavoidable; and they were evaluated by imaging modality and level of training of the physician involved. We identified 484 specific errors in the 265 cases reviewed (mean:1.8 errors/case). Most discrepancies involved staff (45.5%). Two hundred fifty-eight individual cognitive errors were identified in 151 cases (mean = 1.7 errors/case). Of these, 83 cases (55%) had additional perceptual or system-related errors. One hundred sixty-five perceptual errors were identified in 165 cases. Of these, 68 cases (41%) also had cognitive or system-related errors. Fifty-four system-related errors were identified in 46 cases (mean = 1.2 errors/case) of which all were multi-factorial. Seven cases were unavoidable. Our study defines a taxonomy of diagnostic errors in a large academic pediatric radiology practice and suggests that most are multi-factorial in etiology. Further study is needed to define effective strategies for improvement. (orig.)

  10. Georgia : Accounting and Auditing

    OpenAIRE

    2007-01-01

    This report provides an assessment of accounting, financial reporting and auditing requirements and practices within the enterprise and financial sectors in Georgia. The report uses International Financial Reporting Standards (IFRS), International Standards on Auditing (ISA) and draws on international experience and good practices in the field of accounting and audit regulation, including in ...

  11. Internet accounting dictionaries

    DEFF Research Database (Denmark)

    Nielsen, Sandro; Mourier, Lise

    2005-01-01

    An examination of existing accounting dictionaries on the Internet reveals a general need for a new type of dictionary. In contrast to the dictionaries now accessible, the future accounting dictionaries should be designed as proper Internet dictionaries based on a functional approach so they can...

  12. Accounting as an Engine

    DEFF Research Database (Denmark)

    Revellino, Silvana; Mouritsen, Jan

    2015-01-01

    This paper explores the relationships between calculative practices and innovative activities. It investigates how calculative practices such as accounting develop knowledge that functions as an engine (MacKenzie, 2006) for innovation. This is an attempt at exploring the role of accounting through...

  13. Deterrents to Accountability.

    Science.gov (United States)

    Hencley, Stephen P.

    This speech assesses potential deterrents to the implementation of accountability in education. The author divides these deterrents into (1) philosophical-ideological; humanist-behaviorist conflicts, individuality versus "techno-urban fascism," and accountability systems tied to the achievement of cognitive objectives at the lower end of Bloom's…

  14. The Choreography of Accountability

    Science.gov (United States)

    Webb, P. Taylor

    2006-01-01

    The prevailing performance discourse in education claims school improvements can be achieved through transparent accountability procedures. The article identifies how teachers generate performances of their work in order to satisfy accountability demands. By identifying sources of teachers' knowledge that produce choreographed performances, I…

  15. Accounting Faculty Internships

    Directory of Open Access Journals (Sweden)

    Jill Christopher

    2013-06-01

    Full Text Available Accounting professionals, business college accrediting bodies, and even accounting academics themselves acknowledge that there is a disconnect between academe and the rigors and requirements of the accounting profession. Among the suggestions proposed in the literature to reduce this gap is the faculty internship, where accounting faculty members work within the field as accountants. Heretofore, individual case studies report benefits of such internships that accrue to a variety of stakeholder groups beyond just the faculty intern and include the academic institution, students, and accounting profession through faculty internships. This research seeks wider support for these benefits. This descriptive study involved surveying a sample of accounting faculty members to get their opinions about the benefits and drawbacks of faculty internships, and to determine the level of use of faculty internships in accounting. In all, 128 usable responses were obtained, representing a 14.6% response rate. The results of this study reveal that although most faculty members acknowledge the benefits cited in the literature, too few take advantage of faculty internships.

  16. The Accountability Illusion: Kansas

    Science.gov (United States)

    Thomas B. Fordham Institute, 2009

    2009-01-01

    The intent of the No Child Left Behind (NCLB) Act of 2001 is to hold schools accountable for ensuring that all their students achieve mastery in reading and math, with a particular focus on groups that have traditionally been left behind. Under NCLB, states submit accountability plans to the U.S. Department of Education detailing the rules and…

  17. Indonesia : Accounting and Auditing

    OpenAIRE

    World Bank

    2011-01-01

    This report is part of a joint initiative of the World Bank and IMF to prepare Reports on the Observance of Standards and Codes (ROSC). The ROSC Accounting and Auditing review for Indonesia mainly focuses on the strengths and weaknesses of the accounting and auditing environment that influences the quality of corporate financial reporting. It involves both a review of mandatory requirement...

  18. Towards ecosystem accounting

    NARCIS (Netherlands)

    Duku, C.; Rathjens, H.; Zwart, S.J.; Hein, L.

    2015-01-01

    Ecosystem accounting is an emerging field that aims to provide a consistent approach to analysing environment-economy interactions. One of the specific features of ecosystem accounting is the distinction between the capacity and the flow of ecosystem services. Ecohydrological modelling to support

  19. Bulgaria : Accounting and Auditing

    OpenAIRE

    World Bank

    2008-01-01

    An assessment of accounting and auditing practices in Bulgaria is a part of the World Bank and the International Monetary Fund (IMF) joint initiative on reports on the Observance of Standards and Codes (ROSC). The assessment focused on the strengths and weaknesses of the accounting and auditing environment that influences the quality of corporate financial reporting. It used the Internatio...

  20. The Evolution of Accountability

    Science.gov (United States)

    Webb, P. Taylor

    2011-01-01

    Campus 2020: Thinking ahead is a policy in British Columbia (BC), Canada, that attempted to hold universities accountable to performance. Within, I demonstrate how this Canadian articulation of educational accountability intended to develop "governmentality constellations" to control the university and regulate its knowledge output. This…