2010-04-01
... dwelling provided with Category C assistance? 256.11 Section 256.11 Indians BUREAU OF INDIAN AFFAIRS... footage standards for a dwelling provided with Category C assistance? A modest dwelling provided with... bedrooms Total dwelling square footage 1 (maximum) 1-3 2 2 900 4-6 2 3 1050 7 or more 2 4 31350 1 Total...
Deformation analysis with Total Least Squares
Directory of Open Access Journals (Sweden)
M. Acar
2006-01-01
Full Text Available Deformation analysis is one of the main research fields in geodesy. Deformation analysis process comprises measurement and analysis phases. Measurements can be collected using several techniques. The output of the evaluation of the measurements is mainly point positions. In the deformation analysis phase, the coordinate changes in the point positions are investigated. Several models or approaches can be employed for the analysis. One approach is based on a Helmert or similarity coordinate transformation where the displacements and the respective covariance matrix are transformed into a unique datum. Traditionally a Least Squares (LS technique is used for the transformation procedure. Another approach that could be introduced as an alternative methodology is the Total Least Squares (TLS that is considerably a new approach in geodetic applications. In this study, in order to determine point displacements, 3-D coordinate transformations based on the Helmert transformation model were carried out individually by the Least Squares (LS and the Total Least Squares (TLS, respectively. The data used in this study was collected by GPS technique in a landslide area located nearby Istanbul. The results obtained from these two approaches have been compared.
Regularization by truncated total least squares
DEFF Research Database (Denmark)
Hansen, Per Christian; Fierro, R.D; Golub, G.H
1997-01-01
The total least squares (TLS) method is a successful method for noise reduction in linear least squares problems in a number of applications. The TLS method is suited to problems in which both the coefficient matrix and the right-hand side are not precisely known. This paper focuses on the use...... schemes for relativistic hydrodynamical equations. Such an approximate Riemann solver is presented in this paper which treats all waves emanating from an initial discontinuity as themselves discontinuous. Therefore, jump conditions for shocks are approximately used for rarefaction waves. The solver...... is easy to implement in a Godunov scheme and converges rapidly for relativistic hydrodynamics. The fast convergence of the solver indicates the potential of a higher performance of a Godunov scheme in which the solver is used....
Total least squares for anomalous change detection
Theiler, James; Matsekh, Anna M.
2010-04-01
A family of subtraction-based anomalous change detection algorithms is derived from a total least squares (TLSQ) framework. This provides an alternative to the well-known chronochrome algorithm, which is derived from ordinary least squares. In both cases, the most anomalous changes are identified with the pixels that exhibit the largest residuals with respect to the regression of the two images against each other. The family of TLSQbased anomalous change detectors is shown to be equivalent to the subspace RX formulation for straight anomaly detection, but applied to the stacked space. However, this family is not invariant to linear coordinate transforms. On the other hand, whitened TLSQ is coordinate invariant, and special cases of it are equivalent to canonical correlation analysis and optimized covariance equalization. What whitened TLSQ offers is a generalization of these algorithms with the potential for better performance.
A Newton Algorithm for Multivariate Total Least Squares Problems
Directory of Open Access Journals (Sweden)
WANG Leyang
2016-04-01
Full Text Available In order to improve calculation efficiency of parameter estimation, an algorithm for multivariate weighted total least squares adjustment based on Newton method is derived. The relationship between the solution of this algorithm and that of multivariate weighted total least squares adjustment based on Lagrange multipliers method is analyzed. According to propagation of cofactor, 16 computational formulae of cofactor matrices of multivariate total least squares adjustment are also listed. The new algorithm could solve adjustment problems containing correlation between observation matrix and coefficient matrix. And it can also deal with their stochastic elements and deterministic elements with only one cofactor matrix. The results illustrate that the Newton algorithm for multivariate total least squares problems could be practiced and have higher convergence rate.
Cichocki, A; Unbehauen, R
1994-01-01
In this paper a new class of simplified low-cost analog artificial neural networks with on chip adaptive learning algorithms are proposed for solving linear systems of algebraic equations in real time. The proposed learning algorithms for linear least squares (LS), total least squares (TLS) and data least squares (DLS) problems can be considered as modifications and extensions of well known algorithms: the row-action projection-Kaczmarz algorithm and/or the LMS (Adaline) Widrow-Hoff algorithms. The algorithms can be applied to any problem which can be formulated as a linear regression problem. The correctness and high performance of the proposed neural networks are illustrated by extensive computer simulation results.
Shan, Peng; Peng, Silong; Zhao, Yuhui; Tang, Liang
2016-03-01
An analysis of binary mixtures of hydroxyl compound by Attenuated Total Reflection Fourier transform infrared spectroscopy (ATR FT-IR) and classical least squares (CLS) yield large model error due to the presence of unmodeled components such as H-bonded components. To accommodate these spectral variations, polynomial-based least squares (LSP) and polynomial-based total least squares (TLSP) are proposed to capture the nonlinear absorbance-concentration relationship. LSP is based on assuming that only absorbance noise exists; while TLSP takes both absorbance noise and concentration noise into consideration. In addition, based on different solving strategy, two optimization algorithms (limited-memory Broyden-Fletcher-Goldfarb-Shanno (LBFGS) algorithm and Levenberg-Marquardt (LM) algorithm) are combined with TLSP and then two different TLSP versions (termed as TLSP-LBFGS and TLSP-LM) are formed. The optimum order of each nonlinear model is determined by cross-validation. Comparison and analyses of the four models are made from two aspects: absorbance prediction and concentration prediction. The results for water-ethanol solution and ethanol-ethyl lactate solution show that LSP, TLSP-LBFGS, and TLSP-LM can, for both absorbance prediction and concentration prediction, obtain smaller root mean square error of prediction than CLS. Additionally, they can also greatly enhance the accuracy of estimated pure component spectra. However, from the view of concentration prediction, the Wilcoxon signed rank test shows that there is no statistically significant difference between each nonlinear model and CLS. © The Author(s) 2016.
Historical Footage of John Glenn Friendship 7
1962-01-01
The Friendship mission launch on the 20th day of February marked the first time that an American attempts to orbit the Earth. Historical footage of John Glenn's suit up, ride out to the launch pad, countdown, liftoff, booster engine cutoff, and separation of the booster engine escape tower is shown. Views of the Earth, Glenn's manual control of the electrical fly-by wire system, and the recovery of the landing vehicle from the ocean are presented.
Newton-Gauss Algorithm of Robust Weighted Total Least Squares Model
Directory of Open Access Journals (Sweden)
WANG Bin
2015-06-01
Full Text Available Based on the Newton-Gauss iterative algorithm of weighted total least squares (WTLS, a robust WTLS (RWTLS model is presented. The model utilizes the standardized residuals to construct the weight factor function and the square root of the variance component estimator with robustness is obtained by introducing the median method. Therefore, the robustness in both the observation and structure spaces can be simultaneously achieved. To obtain standardized residuals, the linearly approximate cofactor propagation law is employed to derive the expression of the cofactor matrix of WTLS residuals. The iterative calculation steps for RWTLS are also described. The experiment indicates that the model proposed in this paper exhibits satisfactory robustness for gross errors handling problem of WTLS, the obtained parameters have no significant difference with the results of WTLS without gross errors. Therefore, it is superior to the robust weighted total least squares model directly constructed with residuals.
On Solution of Total Least Squares Problems with Multiple Right-hand Sides
Czech Academy of Sciences Publication Activity Database
Hnětynková, I.; Plešinger, Martin; Strakoš, Zdeněk
2008-01-01
Roč. 8, č. 1 (2008), s. 10815-10816 ISSN 1617-7061 R&D Projects: GA AV ČR IAA100300802 Institutional research plan: CEZ:AV0Z10300504 Keywords : total least squares problem * multiple right-hand sides * linear approximation problem Subject RIV: BA - General Mathematics
Analysis of total least squares in estimating the parameters of a mortar trajectory
Energy Technology Data Exchange (ETDEWEB)
Lau, D.L.; Ng, L.C.
1994-12-01
Least Squares (LS) is a method of curve fitting used with the assumption that error exists in the observation vector. The method of Total Least Squares (TLS) is more useful in cases where there is error in the data matrix as well as the observation vector. This paper describes work done in comparing the LS and TLS results for parameter estimation of a mortar trajectory based on a time series of angular observations. To improve the results, we investigated several derivations of the LS and TLS methods, and early findings show TLS provided slightly, 10%, improved results over the LS method.
Least-squares Minimization Approaches to Interpret Total Magnetic Anomalies Due to Spheres
Abdelrahman, E. M.; El-Araby, T. M.; Soliman, K. S.; Essa, K. S.; Abo-Ezz, E. R.
2007-05-01
We have developed three different least-squares approaches to determine successively: the depth, magnetic angle, and amplitude coefficient of a buried sphere from a total magnetic anomaly. By defining the anomaly value at the origin and the nearest zero-anomaly distance from the origin on the profile, the problem of depth determination is transformed into the problem of finding a solution of a nonlinear equation of the form f(z)=0. Knowing the depth and applying the least-squares method, the magnetic angle and amplitude coefficient are determined using two simple linear equations. In this way, the depth, magnetic angle, and amplitude coefficient are determined individually from all observed total magnetic data. The method is applied to synthetic examples with and without random errors and tested on a field example from Senegal, West Africa. In all cases, the depth solutions are in good agreement with the actual ones.
Schaffrin, Burkhard; Felus, Yaron A.
2008-06-01
The multivariate total least-squares (MTLS) approach aims at estimating a matrix of parameters, Ξ, from a linear model ( Y- E Y = ( X- E X ) · Ξ) that includes an observation matrix, Y, another observation matrix, X, and matrices of randomly distributed errors, E Y and E X . Two special cases of the MTLS approach include the standard multivariate least-squares approach where only the observation matrix, Y, is perturbed by random errors and, on the other hand, the data least-squares approach where only the coefficient matrix X is affected by random errors. In a previous contribution, the authors derived an iterative algorithm to solve the MTLS problem by using the nonlinear Euler-Lagrange conditions. In this contribution, new lemmas are developed to analyze the iterative algorithm, modify it, and compare it with a new ‘closed form’ solution that is based on the singular-value decomposition. For an application, the total least-squares approach is used to estimate the affine transformation parameters that convert cadastral data from the old to the new Israeli datum. Technical aspects of this approach, such as scaling the data and fixing the columns in the coefficient matrix are investigated. This case study illuminates the issue of “symmetry” in the treatment of two sets of coordinates for identical point fields, a topic that had already been emphasized by Teunissen (1989, Festschrift to Torben Krarup, Geodetic Institute Bull no. 58, Copenhagen, Denmark, pp 335-342). The differences between the standard least-squares and the TLS approach are analyzed in terms of the estimated variance component and a first-order approximation of the dispersion matrix of the estimated parameters.
The Subversion of Factual Discourse in Found Footage Films
Directory of Open Access Journals (Sweden)
Claudio Vescia Zanini
2016-04-01
Full Text Available Este artigo analisa como o design textual de filmes do formato found footage subverte o discurso factual a fim de potencializar a pretendida sensação de horror na tela. Filmes como Canibal Holocausto (1980, A Bruxa de Blair (1999, Atividade Paranormal (2007 e A Forca (2015 exploram a confusão entre realidade e ficção, interferindo na maneira como parte da audiência reage aos filmes. O artigo também parte do princípio que o found footage é um produto natural da pós-modernidade, que tem a cultura da convergência (JENKINS, 2008 e o desaparecimento do real como duas de suas maiores características.
Directory of Open Access Journals (Sweden)
Cotae Paul
2004-01-01
Full Text Available An algorithm for designing spreading sequences for an overloaded multicellular synchronous DS-CDMA system on uplink is introduced. The criterion used to measure the optimality of the design is the total weighted square correlation (TWSC assuming the channel state information known perfectly at both transmitter and receiver. By using this algorithm it is possible to obtain orthogonal generalized WBE sequences sets for any processing gain. The bandwidth of initial generalized WBE signals of each cell is preserved in the extended signal space associated to multicellular system. Mathematical formalism is illustrated by selected numerical examples.
Czech Academy of Sciences Publication Activity Database
Hnětynková, I.; Plešinger, Martin; Sima, D.M.; Strakoš, Z.; Huffel van, S.
2011-01-01
Roč. 32, č. 3 (2011), s. 748-770 ISSN 0895-4798 R&D Projects: GA AV ČR IAA100300802 Grant - others:GA ČR(CZ) GA201/09/0917 Program:GA Institutional research plan: CEZ:AV0Z10300504 Keywords : total least squares * multiple right-hand sides * linear approximation problems * orthogonally invariant problems * orthogonal regression * errors-in-variables modeling Subject RIV: BA - General Mathematics Impact factor: 1.368, year: 2011
International Nuclear Information System (INIS)
Afari, F.
2011-01-01
The use of equivalent squares is of great value and importance when determining output and depth dose data for rectangular fields. The variation with field shape of collimator scatter factors (S c ), phantom scatter factors (S c,p ) were studied using measurements on GWGP 80 cobalt - 60 teletherapy machine at the National Centre of Radiotherapy and Nuclear Medicine in the Korle-Bu Teaching Hospital. Measurements of the collimator scatter factors (S c ), phantom scatter factors (S p ) and total scatter factors (S c, p) were made at the depth of 5 cm, 10 cm, 15 cm and 20 cm in full scatter water phantom for square field side and rectangular fields of varying dimensions. The measurements were done using the source - axis distance (Sad) technique. The values of total scatter factor (S c,p ), phantom scatter factor and collimator scatter factor (S c ) obtained were used to estimate equivalent squares for the rectangular fields at the various depths. The equivalent squares were computed using the method of interpolation which is based on the scatter analysis of these scatter factors and these estimated equivalent squares were then compared with equivalent squares were then compared with equivalent square fields from BJR (supplement 21) tables of equivalent squares. The research revealed that there were average deviation of 1.5% for smaller rectangular field sizes and 8.8% for elongated rectangular field sizes between the estimated square field sizes and the equivalent square field from BJR (supplement 21) Table of equivalent square fields. The 8.8% for the elongated rectangular fields is not accepted, though such fields are rarely used in our Hospitals. It was found that the values of the equivalent square at the various depth were very consistent and do not vary with reference depth. These findings confirm that the clinical use of the BJR (supplement 21) Table of equivalent squares for total scatter factors and phantom scatter related quantities of rectangular fields is
Kuramochi, Kazuki; Akiyama, Kazunori; Ikeda, Shiro; Tazaki, Fumie; Fish, Vincent L.; Pu, Hung-Yi; Asada, Keiichi; Honma, Mareki
2018-05-01
We propose a new imaging technique for interferometry using sparse modeling, utilizing two regularization terms: the ℓ 1-norm and a new function named total squared variation (TSV) of the brightness distribution. First, we demonstrate that our technique may achieve a superresolution of ∼30% compared with the traditional CLEAN beam size using synthetic observations of two point sources. Second, we present simulated observations of three physically motivated static models of Sgr A* with the Event Horizon Telescope (EHT) to show the performance of proposed techniques in greater detail. Remarkably, in both the image and gradient domains, the optimal beam size minimizing root-mean-squared errors is ≲10% of the traditional CLEAN beam size for ℓ 1+TSV regularization, and non-convolved reconstructed images have smaller errors than beam-convolved reconstructed images. This indicates that TSV is well matched to the expected physical properties of the astronomical images and the traditional post-processing technique of Gaussian convolution in interferometric imaging may not be required. We also propose a feature-extraction method to detect circular features from the image of a black hole shadow and use it to evaluate the performance of the image reconstruction. With this method and reconstructed images, the EHT can constrain the radius of the black hole shadow with an accuracy of ∼10%–20% in present simulations for Sgr A*, suggesting that the EHT would be able to provide useful independent measurements of the mass of the supermassive black holes in Sgr A* and also another primary target, M87.
Person identification from aerial footage by a remote-controlled drone.
Bindemann, Markus; Fysh, Matthew C; Sage, Sophie S K; Douglas, Kristina; Tummon, Hannah M
2017-10-19
Remote-controlled aerial drones (or unmanned aerial vehicles; UAVs) are employed for surveillance by the military and police, which suggests that drone-captured footage might provide sufficient information for person identification. This study demonstrates that person identification from drone-captured images is poor when targets are unfamiliar (Experiment 1), when targets are familiar and the number of possible identities is restricted by context (Experiment 2), and when moving footage is employed (Experiment 3). Person information such as sex, race and age is also difficult to access from drone-captured footage (Experiment 4). These findings suggest that such footage provides a particularly poor medium for person identification. This is likely to reflect the sub-optimal quality of such footage, which is subject to factors such as the height and velocity at which drones fly, viewing distance, unfavourable vantage points, and ambient conditions.
Intra-Diegetic Cameras as Cinematic Actor Assemblages in Found Footage Horror Cinema
DEFF Research Database (Denmark)
Rødje, Kjetil
2017-01-01
that comprises what is commonly known as human actors as well as material entities that play an active part in motion picture images. The use of intra-diegetic cameras in contemporary found footage horror films constitutes a particular case of such cinematic actor assemblages. Through a dynamic relational...... performance, cameras here take on roles as active agents with the potential to affect other elements within the images as well as the films’ audiences. In found footage horror the assemblage mode of operation creates suspense, since the vulnerability of the camera threatens the viewer's access to the depicted...... events. While human characters and individual entities making up the camera assemblage are disposable, the recording is not. Found footage horror crucially hinges upon the survival of the footage. I will further suggest that these films allow filmmakers to experiment with the acting capabilities of intra...
Directory of Open Access Journals (Sweden)
Rodrigo Carreiro
2013-12-01
Full Text Available ake found footage horror films have been massively made in the last two decades. To shoot a fictional script and give to it the texture of a documentary, a filmmaker has to deal with a number of creative restrictions in order to impose to images and sounds an effect of reality present in amateur footage. This essay examines recurring patterns of style, in this subgenre of movies, which have been used to combine narrative clarity and documental verisimilitude – a combination imposed by the presence of recording devices on the diegesis.
Terra, Luciana A; Filgueiras, Paulo R; Tose, Lílian V; Romão, Wanderson; de Souza, Douglas D; de Castro, Eustáquio V R; de Oliveira, Mirela S L; Dias, Júlio C M; Poppi, Ronei J
2014-10-07
Negative-ion mode electrospray ionization, ESI(-), with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was coupled to a Partial Least Squares (PLS) regression and variable selection methods to estimate the total acid number (TAN) of Brazilian crude oil samples. Generally, ESI(-)-FT-ICR mass spectra present a power of resolution of ca. 500,000 and a mass accuracy less than 1 ppm, producing a data matrix containing over 5700 variables per sample. These variables correspond to heteroatom-containing species detected as deprotonated molecules, [M - H](-) ions, which are identified primarily as naphthenic acids, phenols and carbazole analog species. The TAN values for all samples ranged from 0.06 to 3.61 mg of KOH g(-1). To facilitate the spectral interpretation, three methods of variable selection were studied: variable importance in the projection (VIP), interval partial least squares (iPLS) and elimination of uninformative variables (UVE). The UVE method seems to be more appropriate for selecting important variables, reducing the dimension of the variables to 183 and producing a root mean square error of prediction of 0.32 mg of KOH g(-1). By reducing the size of the data, it was possible to relate the selected variables with their corresponding molecular formulas, thus identifying the main chemical species responsible for the TAN values.
Watanabe, Toshifumi; Koga, Hideyuki; Horie, Masafumi; Katagiri, Hiroki; Sekiya, Ichiro; Muneta, Takeshi
2017-12-01
The post-cam mechanism in posterior stabilized (PS) prostheses plays an important role in total knee arthroplasty (TKA). The purpose of this study is to clarify the difference of the contact stress on the tibial post between a rounded post-cam design and a squared design during deep knee flexion and at hyperextension using the three-dimensional (3D) finite element models. We created 2 types of 3D, finite element models of PS prostheses (types A and B), whose surfaces were identical except for the post-cam geometries: type A has a rounded post-cam design, while type B has a squared design. Both types have a similar curved-shape intercondylar notch of the femoral component. Stress distributions, peak contact stresses, and contact areas on the tibial posts at 90°, 120°, and 150° flexion with/without 10° tibial internal rotation and at 10° hyperextension were compared between the 2 models. Type B demonstrated more concentrated stress distribution compared to type A. The peak contact stresses were similar in both groups during neutral flexion; however, the stresses were much higher in type B during flexion with 10° rotation and at hyperextension. The higher peak contact stresses corresponded to the smaller contact areas in the tibial post. A rounded post-cam design demonstrated less stress concentration during flexion with rotation and at hyperextension compared with a squared design. The results would be useful for development of implant designs and prediction of the contact stress on the tibial post in PS total knee arthroplasty. Copyright © 2017 Elsevier Inc. All rights reserved.
The archive effect found footage and the audiovisual experience of history
Baron, Jaimie
2013-01-01
The Archive Effect: Found Footage and the Audiovisual Experience of History examines the problems of representation inherent in the appropriation of archival film and video footage for historical purposes. Baron analyses the way in which the meanings of archival documents are modified when they are placed in new texts and contexts, constructing the viewer's experience of and relationship to the past they portray. Rethinking the notion of the archival document in terms of its reception and the spectatorial experiences it generates, she explores the 'archive effect' as it is produced across the genres of documentary, mockumentary, experimental, and fiction films. This engaging work discusses how, for better or for worse, the archive effect is mobilized to create new histories, alternative histories, and misreadings of history. The book covers a multitude of contemporary cultural artefacts including fiction films like Zelig, Forrest Gump and JFK, mockumentaries such as The Blair Witch Project and Forgotten Silve...
Original footage of the Chilean miners with manganism published in Neurology in 1967.
Miranda, Marcelo; Bustamante, M Leonor; Mena, Francisco; Lees, Andrew
2015-12-15
Manganism has captured the imagination of neurologists for more than a century because of its similarities to Parkinson disease and its indirect but seminal role in the "l-dopa miracle." We present unpublished footage of the original case series reported in Neurology® in 1967 by Mena and Cotzias depicting the typical neurologic signs of manganism in 4 Chilean miners and their response to high doses of l-dopa. © 2015 American Academy of Neurology.
Directory of Open Access Journals (Sweden)
Huaishuo Xiao
2017-11-01
Full Text Available In order to identify various kinds of combined power quality disturbances, the singular value decomposition (SVD and the improved total least squares-estimation of signal parameters via rotational invariance techniques (TLS-ESPRIT are combined as the basis of disturbance identification in this paper. SVD is applied to identify the catastrophe points of disturbance intervals, based on which the disturbance intervals are segmented. Then the improved TLS-ESPRIT optimized by singular value norm method is used to analyze each data segment, and extract the amplitude, frequency, attenuation coefficient and initial phase of various kinds of disturbances. Multi-group combined disturbance test signals are constructed by MATLAB and the proposed method is also tested by the measured data of IEEE Power and Energy Society (PES Database. The test results show that the new method proposed has a relatively higher accuracy than conventional TLS-ESPRIT, which could be used in the identification of measured data.
Liu, Xiu-ying; Wang, Li; Chang, Qing-rui; Wang, Xiao-xing; Shang, Yan
2015-07-01
Wuqi County of Shaanxi Province, where the vegetation recovering measures have been carried out for years, was taken as the study area. A total of 100 loess samples from 24 different profiles were collected. Total nitrogen (TN) and alkali hydrolysable nitrogen (AHN) contents of the soil samples were analyzed, and the soil samples were scanned in the visible/near-infrared (VNIR) region of 350-2500 nm in the laboratory. The calibration models were developed between TN and AHN contents and VNIR values based on correlation analysis (CA) and partial least squares regression (PLS). Independent samples validated the calibration models. The results indicated that the optimum model for predicting TN of loess was established by using first derivative of reflectance. The best model for predicting AHN of loess was established by using normal derivative spectra. The optimum TN model could effectively predict TN in loess from 0 to 40 cm, but the optimum AHN model could only roughly predict AHN at the same depth. This study provided a good method for rapidly predicting TN of loess where vegetation recovering measures have been adopted, but prediction of AHN needs to be further studied.
Khoshmanesh, Aazam; Cook, Perran L M; Wood, Bayden R
2012-08-21
Phosphorus (P) is a major cause of eutrophication and subsequent loss of water quality in freshwater ecosystems. A major part of the flux of P to eutrophic lake sediments is organically bound or of biogenic origin. Despite the broad relevance of polyphosphate (Poly-P) in bioremediation and P release processes in the environment, its quantification is not yet well developed for sediment samples. Current methods possess significant disadvantages because of the difficulties associated with using a single extractant to extract a specific P compound without altering others. A fast and reliable method to estimate the quantitative contribution of microorganisms to sediment P release processes is needed, especially when an excessive P accumulation in the form of polyphosphate (Poly-P) occurs. Development of novel approaches for application of emerging spectroscopic techniques to complex environmental matrices such as sediments significantly contributes to the speciation models of P mobilization, biogeochemical nutrient cycling and development of nutrient models. In this study, for the first time Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy in combination with partial least squares (PLS) was used to quantify Poly-P in sediments. To reduce the high absorption matrix components in sediments such as silica, a physical extraction method was developed to separate sediment biological materials from abiotic particles. The aim was to achieve optimal separation of the biological materials from sediment abiotic particles with minimum chemical change in the sample matrix prior to ATR-FTIR analysis. Using a calibration set of 60 samples for the PLS prediction models in the Poly-P concentration range of 0-1 mg g(-1) d.w. (dry weight of sediment) (R(2) = 0.984 and root mean square error of prediction RMSEP = 0.041 at Factor-1) Poly-P could be detected at less than 50 μg g(-l) d.w. Using this technique, there is no solvent extraction or chemical
DeTemple, Duane
2010-01-01
Purely combinatorial proofs are given for the sum of squares formula, 1[superscript 2] + 2[superscript 2] + ... + n[superscript 2] = n(n + 1) (2n + 1) / 6, and the sum of sums of squares formula, 1[superscript 2] + (1[superscript 2] + 2[superscript 2]) + ... + (1[superscript 2] + 2[superscript 2] + ... + n[superscript 2]) = n(n + 1)[superscript 2]…
DEFF Research Database (Denmark)
Forchhammer, Søren; Kim, Chul E
1988-01-01
Digital squares are defined and their geometric properties characterized. A linear time algorithm is presented that considers a convex digital region and determines whether or not it is a digital square. The algorithm also determines the range of the values of the parameter set of its preimages....... The analysis involves transforming the boundary of a digital region into parameter space of slope and y-intercept...
Language from police body camera footage shows racial disparities in officer respect.
Voigt, Rob; Camp, Nicholas P; Prabhakaran, Vinodkumar; Hamilton, William L; Hetey, Rebecca C; Griffiths, Camilla M; Jurgens, David; Jurafsky, Dan; Eberhardt, Jennifer L
2017-06-20
Using footage from body-worn cameras, we analyze the respectfulness of police officer language toward white and black community members during routine traffic stops. We develop computational linguistic methods that extract levels of respect automatically from transcripts, informed by a thin-slicing study of participant ratings of officer utterances. We find that officers speak with consistently less respect toward black versus white community members, even after controlling for the race of the officer, the severity of the infraction, the location of the stop, and the outcome of the stop. Such disparities in common, everyday interactions between police and the communities they serve have important implications for procedural justice and the building of police-community trust.
Indian Academy of Sciences (India)
Admin
2012-09-07
Sep 7, 2012 ... must first talk of permutations and Latin squares. A permutation of a finite set of objects is a linear arrange- ment of ... with a special element 1 ... Of course, this has .... tion method to disprove Euler's conjecture for infinitely.
Lyon, Betty Clayton
1990-01-01
One method of making magic squares using a prolongated square is illustrated. Discussed are third-order magic squares, fractional magic squares, fifth-order magic squares, decimal magic squares, and even magic squares. (CW)
DEFF Research Database (Denmark)
Rose, Jeremy; Sæbø, Øystein
2005-01-01
On-line political communities, such as the Norwegian site Demokratitorget (Democracy Square), are often designed according to a set of un-reflected assumptions about the political interests of their potential members. In political science, democracy is not taken as given in this way, but can...... be represented by different models which characterize different relationships between politicians and the citizens they represent. This paper uses quantitative and qualitative content analysis to analyze the communication mediated by the Democracy Square discussion forum in the first ten months of its life......-Republican model. In the qualitative analysis the discourse is analysed as repeating genres – patterns in the communication form which also reflect the conflict of interest between citizens and politicians. Though the analysis gives insight into the nature of the discourse the site supports, little is known about...
1972-01-01
With the existing Systems for using the accelerated protons, it is possible to supply only one slow ejected beam (feeding the East Hall) and, at the same time, to have only a small percentage of the beam on an internal target (feeding the South Hall). The arrangement will be replaced by a new System called SQUARE (Semi- QUAdrupole Resonant Extraction) which will give greater flexibility in supplying the three areas.
Birch, Ivan; Vernon, Wesley; Burrow, Gordon; Walker, Jeremy
2014-03-01
Forensic gait analysis is increasingly being used as part of criminal investigations. A major issue is the quality of the closed circuit television (CCTV) footage used, particularly the frame rate which can vary from 25 frames per second to one frame every 4s. To date, no study has investigated the effect of frame rate on forensic gait analysis. A single subject was fitted with an ankle foot orthosis and recorded walking at 25 frames per second. 3D motion data were also collected, providing an absolute assessment of the gait characteristics. The CCTV footage was then edited to produce a set of eight additional pieces of footage, at various frame rates. Practitioners with knowledge of forensic gait analysis were recruited and instructed to record their observations regarding the characteristics of the subject's gait from the footage. They were sequentially sent web links to the nine pieces of footage, lowest frame rate first, and a simple observation recording form, over a period of 8 months. A sample-based Pearson product-moment correlation analysis of the results demonstrated a significant positive relationship between frame rate and scores (r=0.868, p=0.002). The results of this study show that frame rate affects the ability of experienced practitioners to identify characteristics of gait captured on CCTV footage. Every effort should therefore be made to ensure that CCTV footage likely to be used in criminal proceedings is captured at as high a frame rate as possible. © 2013.
Usability of aerial video footage for 3-D scene reconstruction and structural damage assessment
Cusicanqui, Johnny; Kerle, Norman; Nex, Francesco
2018-06-01
Remote sensing has evolved into the most efficient approach to assess post-disaster structural damage, in extensively affected areas through the use of spaceborne data. For smaller, and in particular, complex urban disaster scenes, multi-perspective aerial imagery obtained with unmanned aerial vehicles and derived dense color 3-D models are increasingly being used. These type of data allow the direct and automated recognition of damage-related features, supporting an effective post-disaster structural damage assessment. However, the rapid collection and sharing of multi-perspective aerial imagery is still limited due to tight or lacking regulations and legal frameworks. A potential alternative is aerial video footage, which is typically acquired and shared by civil protection institutions or news media and which tends to be the first type of airborne data available. Nevertheless, inherent artifacts and the lack of suitable processing means have long limited its potential use in structural damage assessment and other post-disaster activities. In this research the usability of modern aerial video data was evaluated based on a comparative quality and application analysis of video data and multi-perspective imagery (photos), and their derivative 3-D point clouds created using current photogrammetric techniques. Additionally, the effects of external factors, such as topography and the presence of smoke and moving objects, were determined by analyzing two different earthquake-affected sites: Tainan (Taiwan) and Pescara del Tronto (Italy). Results demonstrated similar usabilities for video and photos. This is shown by the short 2 cm of difference between the accuracies of video- and photo-based 3-D point clouds. Despite the low video resolution, the usability of these data was compensated for by a small ground sampling distance. Instead of video characteristics, low quality and application resulted from non-data-related factors, such as changes in the scene, lack of
Watson, Gale A.
2003-01-01
Demonstrates the transformations that are possible to construct a variety of magic squares, including modifications to challenge students from elementary grades through algebra. Presents an example of using magic squares with students who have special needs. (YDS)
Gorre, Elsa; Owens, Kevin G
2016-11-01
In this work an attenuated total reflection Fourier transform infrared (FT-IR) absorption based method is used to measure the solubility of two matrix-assisted laser desorption-ionization (MALDI) matrices in a few pure solvents and mixtures of acetonitrile and water using low microliter amounts of solution. Results from a method that averages the values obtained from multiple calibration curves created by manual peak picking are compared to those predicted using a partial least squares (PLS) chemometrics approach. The PLS method provided solubility values that were in good agreement with the manual method with significantly greater ease of analysis. As a test, the solubility of adipic acid in acetone was measured using the two methods of analysis, and the values are in good agreement with solubility values reported in literature. The solubilities of the MALDI matrices α-cyano-4-hydroxy cinnamic acid (CHCA) and sinapinic acid (SA) were measured in a series of mixtures made from acetonitrile (ACN) and water; surprisingly, the results show a highly nonlinear trend. While both CHCA and SA show solubility values of less than 10 mg/mL in the pure solvents, the solubility value for SA increases to 56.3 mg/mL in a 75:25 v/v ACN:water mixture. This can have a significant effect on the matrix-to-analyte ratios in the MALDI experiment when sample protocols call for preparation of a saturated solution of the matrix in the chosen solvent system. © The Author(s) 2016.
Clark, Ian A; Mackay, Clare E; Holmes, Emily A
2015-01-01
Most people will experience or witness a traumatic event. A common occurrence after trauma is the experience of involuntary emotional memories of the traumatic event, herewith "flashbacks". Some individuals, however, report no flashbacks. Prospective work investigating psychological factors associated with an absence of flashbacks is lacking. We performed an individual participant data meta-analysis on 16 experiments (n = 458) using the trauma film paradigm to investigate the association of emotional response to traumatic film footage and commonly collected baseline characteristics (trait anxiety, current depression, trauma history) with an absence of analogue flashbacks. An absence of analogue flashbacks was associated with low emotional response to the traumatic film footage and, to a lesser extent, low trait anxiety and low current depression levels. Trauma history and recognition memory for the film were not significantly associated with an absence of analogue flashbacks. Understanding why some individuals report an absence of flashbacks may aid preventative treatments against flashback development.
Kottmann, R.; Ratmeyer, V.; Pop Ristov, A.; Boetius, A.
2012-04-01
More and more seagoing scientific expeditions use video-controlled research platforms such as Remote Operating Vehicles (ROV), Autonomous Underwater Vehicles (AUV), and towed camera systems. These produce many hours of video material which contains detailed and scientifically highly valuable footage of the biological, chemical, geological, and physical aspects of the oceans. Many of the videos contain unique observations of unknown life-forms which are rare, and which cannot be sampled and studied otherwise. To make such video material online accessible and to create a collaborative annotation environment the "Video Annotation and processing platform" (V-App) was developed. A first solely web-based installation for ROV videos is setup at the German Center for Marine Environmental Sciences (available at http://videolib.marum.de). It allows users to search and watch videos with a standard web browser based on the HTML5 standard. Moreover, V-App implements social web technologies allowing a distributed world-wide scientific community to collaboratively annotate videos anywhere at any time. It has several features fully implemented among which are: • User login system for fine grained permission and access control • Video watching • Video search using keywords, geographic position, depth and time range and any combination thereof • Video annotation organised in themes (tracks) such as biology and geology among others in standard or full screen mode • Annotation keyword management: Administrative users can add, delete, and update single keywords for annotation or upload sets of keywords from Excel-sheets • Download of products for scientific use This unique web application system helps making costly ROV videos online available (estimated cost range between 5.000 - 10.000 Euros per hour depending on the combination of ship and ROV). Moreover, with this system each expert annotation adds instantaneous available and valuable knowledge to otherwise uncharted
Misiurewicz, Michal
2013-01-01
If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?
International Nuclear Information System (INIS)
Akita, Junji; Honma, Toei.
1975-01-01
Object: To provide a square through tube involving thermal movement in pipelines such as water supply pump driving turbine exhaust pipe (square-shaped), which is wide in freedom with respect to shape and dimension thereof for efficient installation at site. Structure: In a through tube to be airtightly retained for purpose of decontamination in an atomic power plant, comprising a seal rubber plate, a band and a bolt and a nut for securing said plate, the seal rubber plate being worked into the desired shape so that it may be placed in intimate contact with the concrete floor surface by utilization of elasticity of rubber, thereby providing airtightness at a corner portion of the square tube. (Kamimura, M.)
International Nuclear Information System (INIS)
Dory, R.A.; Uckan, N.A.; Ard, W.B.
1986-10-01
The ELMO Bumpy Square (EBS) concept consists of four straight magnetic mirror arrays linked by four high-field corner coils. Extensive calculations show that this configuration offers major improvements over the ELMO Bumpy Torus (EBT) in particle confinement, heating, transport, ring production, and stability. The components of the EBT device at Oak Ridge National Laboratory can be reconfigured into a square arrangement having straight sides composed of EBT coils, with new microwave cavities and high-field corners designed and built for this application. The elimination of neoclassical convection, identified as the dominant mechanism for the limited confinement in EBT, will give the EBS device substantially improved confinement and the flexibility to explore the concepts that produce this improvement. The primary goals of the EBS program are twofold: first, to improve the physics of confinement in toroidal systems by developing the concepts of plasma stabilization using the effects of energetic electrons and confinement optimization using magnetic field shaping and electrostatic potential control to limit particle drift, and second, to develop bumpy toroid devices as attractive candidates for fusion reactors. This report presents a brief review of the physics analyses that support the EBS concept, discussions of the design and expected performance of the EBS device, a description of the EBS experimental program, and a review of the reactor potential of bumpy toroid configurations. Detailed information is presented in the appendices
International Nuclear Information System (INIS)
Cufaro-Petroni, Nicola; Garuccio, Augusto; Selleri, Franco; Vigier, J.-P.
1980-01-01
As is known the experimental verification of quantum mechanics (and not of Bell's inequalities) in experiments of the Einstein-Podolsky-Rosen Aspect-type (involving two correlated photons emitted in the single state) implies the existence of non local faster than light, interactions between two quantum apparatus of measurement. It is shown in this work that if one assumes that real quantum measurements correspond to the usual classical (idealised) scheme (and are reproducible in time) the wave packet collapse of correlated particles by the intervention of a real physical apparatus in the Einstein-Podolsky-Rosen Paradox implies the non conservation of the total angular momentum of the isolated apparatus-particle system [fr
Williams, Horace E.
1974-01-01
A method for generating 3x3 magic squares is developed. A series of questions relating to these magic squares is posed. An invesitgation using matrix methods is suggested with some questions for consideration. (LS)
International Nuclear Information System (INIS)
Anon.
1991-01-01
On September 23 last year, in a national referendum, environmentalists won the right to a new Energy Article in the Swiss Constitution, and anti-nuclear forces triumphed again by imposing a 10-year moratorium on new nuclear power stations. The dilemma now facing the energy minister how to ensure Swiss prosperity while working within the new conditions restricting energy use. A Swiss Action Programme ''Energy 2000'' has been drawn up. The Programme closely corresponds to one drawn up by the four parties of the national coalition government. Its objectives seem modest: stabilisation at 1990 levels of the total fossil energy consumption and CO 2 emissions by 2000, with reduction thereafter; slowing the growth of electricity consumption in an attempt to stabilise demand by 2000; a ''significant increase'' in the contribution of renewable energy and hydropower; and refurbishment and life extension of nuclear plant. (author)
From Square Dance to Mathematics
Bremer, Zoe
2010-01-01
In this article, the author suggests a cross-curricular idea that can link with PE, dance, music and history. Teacher David Schmitz, a maths teacher in Illinois who was also a square dance caller, had developed a maths course that used the standard square dance syllabus to teach mathematical principles. He presents an intensive, two-week course…
Counting Triangles to Sum Squares
DeMaio, Joe
2012-01-01
Counting complete subgraphs of three vertices in complete graphs, yields combinatorial arguments for identities for sums of squares of integers, odd integers, even integers and sums of the triangular numbers.
Time Scale in Least Square Method
Directory of Open Access Journals (Sweden)
Özgür Yeniay
2014-01-01
Full Text Available Study of dynamic equations in time scale is a new area in mathematics. Time scale tries to build a bridge between real numbers and integers. Two derivatives in time scale have been introduced and called as delta and nabla derivative. Delta derivative concept is defined as forward direction, and nabla derivative concept is defined as backward direction. Within the scope of this study, we consider the method of obtaining parameters of regression equation of integer values through time scale. Therefore, we implemented least squares method according to derivative definition of time scale and obtained coefficients related to the model. Here, there exist two coefficients originating from forward and backward jump operators relevant to the same model, which are different from each other. Occurrence of such a situation is equal to total number of values of vertical deviation between regression equations and observation values of forward and backward jump operators divided by two. We also estimated coefficients for the model using ordinary least squares method. As a result, we made an introduction to least squares method on time scale. We think that time scale theory would be a new vision in least square especially when assumptions of linear regression are violated.
A Weighted Least Squares Approach To Robustify Least Squares Estimates.
Lin, Chowhong; Davenport, Ernest C., Jr.
This study developed a robust linear regression technique based on the idea of weighted least squares. In this technique, a subsample of the full data of interest is drawn, based on a measure of distance, and an initial set of regression coefficients is calculated. The rest of the data points are then taken into the subsample, one after another,…
Moreno, Carlos J
2005-01-01
Introduction Prerequisites Outline of Chapters 2 - 8 Elementary Methods Introduction Some Lemmas Two Fundamental Identities Euler's Recurrence for Sigma(n)More Identities Sums of Two Squares Sums of Four Squares Still More Identities Sums of Three Squares An Alternate Method Sums of Polygonal Numbers Exercises Bernoulli Numbers Overview Definition of the Bernoulli Numbers The Euler-MacLaurin Sum Formula The Riemann Zeta Function Signs of Bernoulli Numbers Alternate The von Staudt-Clausen Theorem Congruences of Voronoi and Kummer Irregular Primes Fractional Parts of Bernoulli Numbers Exercises Examples of Modular Forms Introduction An Example of Jacobi and Smith An Example of Ramanujan and Mordell An Example of Wilton: t (n) Modulo 23 An Example of Hamburger Exercises Hecke's Theory of Modular FormsIntroduction Modular Group ? and its Subgroup ? 0 (N) Fundamental Domains For ? and ? 0 (N) Integral Modular Forms Modular Forms of Type Mk(? 0(N);chi) and Euler-Poincare series Hecke Operators Dirichlet Series and ...
Graphs whose complement and square are isomorphic
DEFF Research Database (Denmark)
Pedersen, Anders Sune
2014-01-01
We study square-complementary graphs, that is, graphs whose complement and square are isomorphic. We prove several necessary conditions for a graph to be square-complementary, describe ways of building new square-complementary graphs from existing ones, construct infinite families of square-compl...
Agglomerative clustering of growing squares
Castermans, Thom; Speckmann, Bettina; Staals, Frank; Verbeek, Kevin; Bender, M.A.; Farach-Colton, M.; Mosteiro, M.A.
2018-01-01
We study an agglomerative clustering problem motivated by interactive glyphs in geo-visualization. Consider a set of disjoint square glyphs on an interactive map. When the user zooms out, the glyphs grow in size relative to the map, possibly with different speeds. When two glyphs intersect, we wish
Fullwood, James; Wang, Dongxu
2018-01-01
We introduce a class of F-theory vacua whose smooth elliptic fibers admit a vanishing $j$-invariant, and construct a weak coupling limit associated with such vacua which we view as the `square' of the Sen limit. We find that while Sen's limit is naturally viewed as an orientifold theory, the universal tadpole relation which equates the D3 charge between the associated F-theory compactification and the limit we construct suggests that perhaps the limiting theory is in fact an oriented theory c...
Renaming Zagreb Streets and Squares
Directory of Open Access Journals (Sweden)
Jelena Stanić
2009-06-01
Full Text Available The paper deals with changes in street names in the city of Zagreb. Taking the Lower Town (Donji grad city area as an example, the first part of the paper analyses diachronic street name changes commencing from the systematic naming of streets in 1878. Analysis of official changes in street names throughout Zagreb’s history resulted in categorisation of five periods of ideologically motivated naming/name-changing: 1. the Croatia modernisation period, when the first official naming was put into effect, with a marked tendency towards politicisation and nationalisation of the urban landscape; 2. the period of the Kingdom of the Serbs, Croatians and Slovenians/Yugoslavia, when symbols of the new monarchy, the idea of the fellowship of the Southern Slavs, Slavenophilism and the pro-Slavic geopolitical orientation were incorporated into the street names, and when the national idea was highly evident and remained so in that process; 3. the period of the NDH, the Independent State of Croatia, with decanonisation of the tokens of the Yugoslavian monarchy and the Southern Slavic orientation, and reference to the Ustashi and the German Nazi and Italian Fascist movement; 4. the period of Socialism, embedding the ideals and heroes of the workers’ movement and the War of National Liberation into the canonical system; and, 5. the period following the democratic changes in 1990, when almost all the signs of Socialism and the Communist/Antifascist struggle were erased, with the prominent presence of a process of installing new references to early national culture and historical tradition. The closing part of the paper deals with public discussions connected with the selection of a location for a square to bear the name of the first president of independent Croatia, Franjo Tuđman. Analysis of these public polemics shows two opposing discourses: the right-wing political option, which supports a central position for the square and considers the chosen area to
Latin squares and their applications
Keedwell, A Donald
2015-01-01
Latin Squares and Their Applications Second edition offers a long-awaited update and reissue of this seminal account of the subject. The revision retains foundational, original material from the frequently-cited 1974 volume but is completely updated throughout. As with the earlier version, the author hopes to take the reader 'from the beginnings of the subject to the frontiers of research'. By omitting a few topics which are no longer of current interest, the book expands upon active and emerging areas. Also, the present state of knowledge regarding the 73 then-unsolved problems given at the
A new stabilized least-squares imaging condition
International Nuclear Information System (INIS)
Vivas, Flor A; Pestana, Reynam C; Ursin, Bjørn
2009-01-01
The classical deconvolution imaging condition consists of dividing the upgoing wave field by the downgoing wave field and summing over all frequencies and sources. The least-squares imaging condition consists of summing the cross-correlation of the upgoing and downgoing wave fields over all frequencies and sources, and dividing the result by the total energy of the downgoing wave field. This procedure is more stable than using the classical imaging condition, but it still requires stabilization in zones where the energy of the downgoing wave field is small. To stabilize the least-squares imaging condition, the energy of the downgoing wave field is replaced by its average value computed in a horizontal plane in poorly illuminated regions. Applications to the Marmousi and Sigsbee2A data sets show that the stabilized least-squares imaging condition produces better images than the least-squares and cross-correlation imaging conditions
Squares of Random Linear Codes
DEFF Research Database (Denmark)
Cascudo Pueyo, Ignacio; Cramer, Ronald; Mirandola, Diego
2015-01-01
a positive answer, for codes of dimension $k$ and length roughly $\\frac{1}{2}k^2$ or smaller. Moreover, the convergence speed is exponential if the difference $k(k+1)/2-n$ is at least linear in $k$. The proof uses random coding and combinatorial arguments, together with algebraic tools involving the precise......Given a linear code $C$, one can define the $d$-th power of $C$ as the span of all componentwise products of $d$ elements of $C$. A power of $C$ may quickly fill the whole space. Our purpose is to answer the following question: does the square of a code ``typically'' fill the whole space? We give...
Square-root measurement for pure states
International Nuclear Information System (INIS)
Huang Siendong
2005-01-01
Square-root measurement is a very useful suboptimal measurement in many applications. It was shown that the square-root measurement minimizes the squared error for pure states. In this paper, the least squared error problem is reformulated and a new proof is provided. It is found that the least squared error depends only on the average density operator of the input states. The properties of the least squared error are then discussed, and it is shown that if the input pure states are uniformly distributed, the average probability of error has an upper bound depending on the least squared error, the rank of the average density operator, and the number of the input states. The aforementioned properties help explain why the square-root measurement can be effective in decoding processes
36 CFR 910.67 - Square guidelines.
2010-07-01
... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Square guidelines. 910.67... GUIDELINES AND UNIFORM STANDARDS FOR URBAN PLANNING AND DESIGN OF DEVELOPMENT WITHIN THE PENNSYLVANIA AVENUE DEVELOPMENT AREA Glossary of Terms § 910.67 Square guidelines. Square Guidelines establish the Corporation's...
... page: //medlineplus.gov/ency/article/003483.htm Total protein To use the sharing features on this page, please enable JavaScript. The total protein test measures the total amount of two classes ...
Square pulse linear transformer driver
Directory of Open Access Journals (Sweden)
A. A. Kim
2012-04-01
Full Text Available The linear transformer driver (LTD technological approach can result in relatively compact devices that can deliver fast, high current, and high-voltage pulses straight out of the LTD cavity without any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The usual LTD architecture [A. A. Kim, M. G. Mazarakis, V. A. Sinebryukhov, B. M. Kovalchuk, V. A. Vizir, S. N Volkov, F. Bayol, A. N. Bastrikov, V. G. Durakov, S. V. Frolov, V. M. Alexeenko, D. H. McDaniel, W. E. Fowler, K. LeCheen, C. Olson, W. A. Stygar, K. W. Struve, J. Porter, and R. M. Gilgenbach, Phys. Rev. ST Accel. Beams 12, 050402 (2009PRABFM1098-440210.1103/PhysRevSTAB.12.050402; M. G. Mazarakis, W. E. Fowler, A. A. Kim, V. A. Sinebryukhov, S. T. Rogowski, R. A. Sharpe, D. H. McDaniel, C. L. Olson, J. L. Porter, K. W. Struve, W. A. Stygar, and J. R. Woodworth, Phys. Rev. ST Accel. Beams 12, 050401 (2009PRABFM1098-440210.1103/PhysRevSTAB.12.050401] provides sine shaped output pulses that may not be well suited for some applications like z-pinch drivers, flash radiography, high power microwaves, etc. A more suitable power pulse would have a flat or trapezoidal (rising or falling top. In this paper, we present the design and first test results of an LTD cavity that generates such a type of output pulse by including within its circular array a number of third harmonic bricks in addition to the main bricks. A voltage adder made out of a square pulse cavity linear array will produce the same shape output pulses provided that the timing of each cavity is synchronized with the propagation of the electromagnetic pulse.
Weighted conditional least-squares estimation
International Nuclear Information System (INIS)
Booth, J.G.
1987-01-01
A two-stage estimation procedure is proposed that generalizes the concept of conditional least squares. The method is instead based upon the minimization of a weighted sum of squares, where the weights are inverses of estimated conditional variance terms. Some general conditions are given under which the estimators are consistent and jointly asymptotically normal. More specific details are given for ergodic Markov processes with stationary transition probabilities. A comparison is made with the ordinary conditional least-squares estimators for two simple branching processes with immigration. The relationship between weighted conditional least squares and other, more well-known, estimators is also investigated. In particular, it is shown that in many cases estimated generalized least-squares estimators can be obtained using the weighted conditional least-squares approach. Applications to stochastic compartmental models, and linear models with nested error structures are considered
Sets of Mutually Orthogonal Sudoku Latin Squares
Vis, Timothy; Petersen, Ryan M.
2009-01-01
A Latin square of order "n" is an "n" x "n" array using n symbols, such that each symbol appears exactly once in each row and column. A set of Latin squares is c ordered pairs of symbols appearing in the cells of the array are distinct. The popular puzzle Sudoku involves Latin squares with n = 9, along with the added condition that each of the 9…
The Square Light Clock and Special Relativity
Galli, J. Ronald; Amiri, Farhang
2012-01-01
A thought experiment that includes a square light clock is similar to the traditional vertical light beam and mirror clock, except it is made up of four mirrors placed at a 45[degree] angle at each corner of a square of length L[subscript 0], shown in Fig. 1. Here we have shown the events as measured in the rest frame of the square light clock. By…
Tel, G.
We define the notion of total algorithms for networks of processes. A total algorithm enforces that a "decision" is taken by a subset of the processes, and that participation of all processes is required to reach this decision. Total algorithms are an important building block in the design of
Two Enhancements of the Logarithmic Least-Squares Method for Analyzing Subjective Comparisons
1989-03-25
error term. 1 For this model, the total sum of squares ( SSTO ), defined as n 2 SSTO = E (yi y) i=1 can be partitioned into error and regression sums...of the regression line around the mean value. Mathematically, for the model given by equation A.4, SSTO = SSE + SSR (A.6) A-4 where SSTO is the total...sum of squares (i.e., the variance of the yi’s), SSE is error sum of squares, and SSR is the regression sum of squares. SSTO , SSE, and SSR are given
Distribution of squares modulo a composite number
Aryan, Farzad
2015-01-01
In this paper we study the distribution of squares modulo a square-free number $q$. We also look at inverse questions for the large sieve in the distribution aspect and we make improvements on existing results on the distribution of $s$-tuples of reduced residues.
Some Theoretical Essences of Lithuania Squares Formation
Directory of Open Access Journals (Sweden)
Gintautas Tiškus
2016-04-01
Full Text Available In the Lithuanian acts of law and in the scientific literature there are no clear criteria and notions to define a square. The unbuilt city space places or the gaps between buildings are often defined as the squares, which do not have clear limits or destination. The mandatory attributes of the place which is called the square are indicated in the article, the notion of square is defined. The article deals with Lithuanian squares theme, analyses the differences between representation and representativeness. The article aims to indicate an influence of city environmental context and monument in the square on its function. The square is an independent element of city plan structure, but it is not an independent element of city spatial structure. The space and environment of the square are related to each other not only by physical, aesthetical relations, but as well as by causalities, which may be named as the essences of squares’ formation. The interdisciplinary discourse analysis method is applied in the article.
Entrywise Squared Transforms for GAMP Supplementary Material
DEFF Research Database (Denmark)
2016-01-01
Supplementary material for a study on Entrywise Squared Transforms for Generalized Approximate Message Passing (GAMP). See the README file for the details.......Supplementary material for a study on Entrywise Squared Transforms for Generalized Approximate Message Passing (GAMP). See the README file for the details....
Lagrange’s Four-Square Theorem
Directory of Open Access Journals (Sweden)
Watase Yasushige
2015-02-01
Full Text Available This article provides a formalized proof of the so-called “the four-square theorem”, namely any natural number can be expressed by a sum of four squares, which was proved by Lagrange in 1770. An informal proof of the theorem can be found in the number theory literature, e.g. in [14], [1] or [23].
BIOMECHANICS. Why the seahorse tail is square.
Porter, Michael M; Adriaens, Dominique; Hatton, Ross L; Meyers, Marc A; McKittrick, Joanna
2015-07-03
Whereas the predominant shapes of most animal tails are cylindrical, seahorse tails are square prisms. Seahorses use their tails as flexible grasping appendages, in spite of a rigid bony armor that fully encases their bodies. We explore the mechanics of two three-dimensional-printed models that mimic either the natural (square prism) or hypothetical (cylindrical) architecture of a seahorse tail to uncover whether or not the square geometry provides any functional advantages. Our results show that the square prism is more resilient when crushed and provides a mechanism for preserving articulatory organization upon extensive bending and twisting, as compared with its cylindrical counterpart. Thus, the square architecture is better than the circular one in the context of two integrated functions: grasping ability and crushing resistance. Copyright © 2015, American Association for the Advancement of Science.
Owens, Tom
2006-01-01
This article presents an interview with James Howe, author of "The Misfits" and "Totally Joe". In this interview, Howe discusses tolerance, diversity and the parallels between his own life and his literature. Howe's four books in addition to "The Misfits" and "Totally Joe" and his list of recommended books with lesbian, gay, bisexual, transgender,…
Around and Beyond the Square of Opposition
Béziau, Jean-Yves
2012-01-01
aiThe theory of oppositions based on Aristotelian foundations of logic has been pictured in a striking square diagram which can be understood and applied in many different ways having repercussions in various fields: epistemology, linguistics, mathematics, psychology. The square can also be generalized in other two-dimensional or multi-dimensional objects extending in breadth and depth the original theory of oppositions of Aristotle. The square of opposition is a very attractive theme which has been going through centuries without evaporating. Since 10 years there is a new growing interest for
Partial update least-square adaptive filtering
Xie, Bei
2014-01-01
Adaptive filters play an important role in the fields related to digital signal processing and communication, such as system identification, noise cancellation, channel equalization, and beamforming. In practical applications, the computational complexity of an adaptive filter is an important consideration. The Least Mean Square (LMS) algorithm is widely used because of its low computational complexity (O(N)) and simplicity in implementation. The least squares algorithms, such as Recursive Least Squares (RLS), Conjugate Gradient (CG), and Euclidean Direction Search (EDS), can converge faster a
Energy Technology Data Exchange (ETDEWEB)
Patinkin, L.
1983-12-01
This report presents data on square footage and on total energy consumption and expenditures for commercial buildings in the contiguous United States. Also included are detailed consumption and expenditures tables for fuel oil or kerosene, liquid petroleum gas (LPG), and purchased steam. Commercial buildings include all nonresidential buildings with the exception of those where industrial activities occupy more of the total square footage than any other type of activity. 7 figures, 23 tables.
Elmo bumpy square plasma confinement device
Owen, L.W.
1985-01-01
The invention is an Elmo bumpy type plasma confinement device having a polygonal configuration of closed magnet field lines for improved plasma confinement. In the preferred embodiment, the device is of a square configuration which is referred to as an Elmo bumpy square (EBS). The EBS is formed by four linear magnetic mirror sections each comprising a plurality of axisymmetric assemblies connected in series and linked by 90/sup 0/ sections of a high magnetic field toroidal solenoid type field generating coils. These coils provide corner confinement with a minimum of radial dispersion of the confined plasma to minimize the detrimental effects of the toroidal curvature of the magnetic field. Each corner is formed by a plurality of circular or elliptical coils aligned about the corner radius to provide maximum continuity in the closing of the magnetic field lines about the square configuration confining the plasma within a vacuum vessel located within the various coils forming the square configuration confinement geometry.
Quantized kernel least mean square algorithm.
Chen, Badong; Zhao, Songlin; Zhu, Pingping; Príncipe, José C
2012-01-01
In this paper, we propose a quantization approach, as an alternative of sparsification, to curb the growth of the radial basis function structure in kernel adaptive filtering. The basic idea behind this method is to quantize and hence compress the input (or feature) space. Different from sparsification, the new approach uses the "redundant" data to update the coefficient of the closest center. In particular, a quantized kernel least mean square (QKLMS) algorithm is developed, which is based on a simple online vector quantization method. The analytical study of the mean square convergence has been carried out. The energy conservation relation for QKLMS is established, and on this basis we arrive at a sufficient condition for mean square convergence, and a lower and upper bound on the theoretical value of the steady-state excess mean square error. Static function estimation and short-term chaotic time-series prediction examples are presented to demonstrate the excellent performance.
Anomalous structural transition of confined hard squares.
Gurin, Péter; Varga, Szabolcs; Odriozola, Gerardo
2016-11-01
Structural transitions are examined in quasi-one-dimensional systems of freely rotating hard squares, which are confined between two parallel walls. We find two competing phases: one is a fluid where the squares have two sides parallel to the walls, while the second one is a solidlike structure with a zigzag arrangement of the squares. Using transfer matrix method we show that the configuration space consists of subspaces of fluidlike and solidlike phases, which are connected with low probability microstates of mixed structures. The existence of these connecting states makes the thermodynamic quantities continuous and precludes the possibility of a true phase transition. However, thermodynamic functions indicate strong tendency for the phase transition and our replica exchange Monte Carlo simulation study detects several important markers of the first order phase transition. The distinction of a phase transition from a structural change is practically impossible with simulations and experiments in such systems like the confined hard squares.
The inverse square law of gravitation
International Nuclear Information System (INIS)
Cook, A.H.
1987-01-01
The inverse square law of gravitation is very well established over the distances of celestial mechanics, while in electrostatics the law has been shown to be followed to very high precision. However, it is only within the last century that any laboratory experiments have been made to test the inverse square law for gravitation, and all but one has been carried out in the last ten years. At the same time, there has been considerable interest in the possibility of deviations from the inverse square law, either because of a possible bearing on unified theories of forces, including gravitation or, most recently, because of a possible additional fifth force of nature. In this article the various lines of evidence for the inverse square law are summarized, with emphasis upon the recent laboratory experiments. (author)
Applications of square-related theorems
Srinivasan, V. K.
2014-04-01
The square centre of a given square is the point of intersection of its two diagonals. When two squares of different side lengths share the same square centre, there are in general four diagonals that go through the same square centre. The Two Squares Theorem developed in this paper summarizes some nice theoretical conclusions that can be obtained when two squares of different side lengths share the same square centre. These results provide the theoretical basis for two of the constructions given in the book of H.S. Hall and F.H. Stevens , 'A Shorter School Geometry, Part 1, Metric Edition'. In page 134 of this book, the authors present, in exercise 4, a practical construction which leads to a verification of the Pythagorean theorem. Subsequently in Theorems 29 and 30, the authors present the standard proofs of the Pythagorean theorem and its converse. In page 140, the authors present, in exercise 15, what amounts to a geometric construction, whose verification involves a simple algebraic identity. Both the constructions are of great importance and can be replicated by using the standard equipment provided in a 'geometry toolbox' carried by students in high schools. The author hopes that the results proved in this paper, in conjunction with the two constructions from the above-mentioned book, would provide high school students an appreciation of the celebrated theorem of Pythagoras. The diagrams that accompany this document are based on the free software GeoGebra. The author formally acknowledges his indebtedness to the creators of this free software at the end of this document.
Power Efficient Division and Square Root Unit
DEFF Research Database (Denmark)
Liu, Wei; Nannarelli, Alberto
2012-01-01
Although division and square root are not frequent operations, most processors implement them in hardware to not compromise the overall performance. Two classes of algorithms implement division or square root: digit-recurrence and multiplicative (e.g., Newton-Raphson) algorithms. Previous work....... The proposed unit is compared to similar solutions based on the digit-recurrence algorithm and it is compared to a unit based on the multiplicative Newton-Raphson algorithm....
Characteristics of Fluid Force Reduction for Two Different Square Prisms in a Tandem Arrangement
Energy Technology Data Exchange (ETDEWEB)
Ro, Ki Deok; Kang, Chang Whan; Park, Kwon Ho [Gyeongsang Nat’l Univ., Jinju (Korea, Republic of)
2017-07-15
The Characteristics of the flow fields of a square prism having a small square prism were investigated by measuring of lift and drag on the square prism and visualizing the flow field using PIV. The experimental parameters were the width ratios(H/B=0.2~0.6) of small square prisms to the prism width and the gap ratios (G/B=0~3) between the prism and the small square prism. The drag reduction rate of the square prism initially increased and then decreased with the G/B ratio for the same H/B ratio, and increased with the H/B ratio for the same G/B ratio. The maximum drag reduction rate of 98.0% was observed at H/B=0.6 and G/B=1.0. The lift reduction rate of the square prism was not affected by the width and gap ratios; the total average value was approximately 66.5%. In case of a square prism having a small square prism, the stagnation regions were represented in the upstream and downstream sides of the square prism.
Capturing, annotating and reflecting video footage
DEFF Research Database (Denmark)
Eckardt, Max Roald; Wagner, Johannes
A presentation of interaction field data capturing setups for uninterrupted long term capturing. Two setups were described: the AMU forklift driving school with 17 cameras and the Digital Days 2016 at University College Nord in Aalborg with 16 kameras, 14 audio recorders, and two HDMI recorders....
Directory of Open Access Journals (Sweden)
Vicente Sánchez-Biosca
2016-08-01
Full Text Available En 2010, un documental germano-israelí –A Film Unfinished– recuperaba enigmáticos planos rodados por un equipo de cineastas alemanes (Propaganda Kompanien en el ghetto de Varsovia durante la primavera de 1942. Una porción considerable de estos planos que el Ministerio de Propaganda de Goebbels decidió no utilizar por confusas razones ya había circulado profusamente en films anteriores, desde los años 50. Depositados en los archivos de la DEFA, habían sido utilizados a contrario en primer lugar por cineastas de la RDA y de la DDR: tratando de denunciar a sus autores. Dicho de otro modo, las imágenes llamadas a denigrar a los judíos servían para denunciar a sus autores, convirtiéndose en eficaz arma del antifascismo. También Frédéric Rossif acudió a ellas en Le temps du ghetto. El presente ensayo analiza las estrategias de apropiación de este material bruto en distintas épocas en relación con las premisas estéticas, éticas, políticas de distintos autores y movimientos para concluir sobre la forma de representar víctimas tomando como fuente la imagen producida por el odio de sus enemigos. Así, se pasa revista a su montaje, su aligeramiento, su relación con testimonios vivos, su conducción a través de una voice over narration, entre otras cosas.Palabras clave: Documental de apropiación, imagen de archivo, migración de imágenes, cinee historia, ghetto de Varsovia, cine nazi.AbstractIn 2010, a German-Israeli documentary entitled A Film Unfinished recovered some enigmatic footage shot by a team of German filmmakers (Propaganda Kompanien in the Warsaw ghetto during the spring of 1942. A considerable portion of these shots had circulated widely in previous films from the 50s, even though the Minister of Propaganda, Joseph Goebbels, decided not to use them for confusing reasons. Shelved in the DEFA archives, they were used by anti-nazi film makers to denounce their authors. In other words, these images called to denigrate
Quantum dynamics of relativistic bosons through nonminimal vector square potentials
Energy Technology Data Exchange (ETDEWEB)
Oliveira, Luiz P. de, E-mail: oliveira.phys@gmail.com
2016-09-15
The dynamics of relativistic bosons (scalar and vectorial) through nonminimal vector square (well and barrier) potentials is studied in the Duffin–Kemmer–Petiau (DKP) formalism. We show that the problem can be mapped in effective Schrödinger equations for a component of the DKP spinor. An oscillatory transmission coefficient is found and there is total reflection. Additionally, the energy spectrum of bound states is obtained and reveals the Schiff–Snyder–Weinberg effect, for specific conditions the potential lodges bound states of particles and antiparticles. - Highlights: • DKP bosons in a nonminimal vector square potential are studied. • Spin zero and spin one bosons have the same results. • The Schiff–Snyder–Weinberg effect is observed.
Non-spill control squared cascade
International Nuclear Information System (INIS)
Kai, Tsunetoshi; Inoue, Yoshiya; Oya, Akio; Suemori, Nobuo.
1974-01-01
Object: To reduce a mixed loss thus enhancing separating efficiency by the provision of a simple arrangement wherein a reflux portion in a conventional spill control squared cascade is replaced by a special stage including centrifugal separators. Structure: Steps in the form of a square cascade, in which a plurality of centrifugal separators are connected by pipe lines, are accumulated in multistage fashion to form a squared cascade. Between the adjoining steps is disposed a special stage including a centrifugal separator which receives both lean flow from the upper step and rich flow from the lower step. The centrifugal separator in the special stage has its rich side connected to the upper step and its lean side connected to the lower step. Special stages are each disposed at the upper side of the uppermost step and at the lower side of the lowermost step. (Kamimura, M.)
Least Squares Data Fitting with Applications
DEFF Research Database (Denmark)
Hansen, Per Christian; Pereyra, Víctor; Scherer, Godela
As one of the classical statistical regression techniques, and often the first to be taught to new students, least squares fitting can be a very effective tool in data analysis. Given measured data, we establish a relationship between independent and dependent variables so that we can use the data....... In a number of applications, the accuracy and efficiency of the least squares fit is central, and Per Christian Hansen, Víctor Pereyra, and Godela Scherer survey modern computational methods and illustrate them in fields ranging from engineering and environmental sciences to geophysics. Anyone working...... with problems of linear and nonlinear least squares fitting will find this book invaluable as a hands-on guide, with accessible text and carefully explained problems. Included are • an overview of computational methods together with their properties and advantages • topics from statistical regression analysis...
Good Filtrations and the Steinberg Square
DEFF Research Database (Denmark)
Kildetoft, Tobias
that tensoring the Steinberg module with a simple module of restricted highest weight gives a module with a good filtration. This result was first proved by Andersen when the characteristic is large enough. In this dissertation, generalizations of those results, which are joint work with Daniel Nakano......, the socle completely determines how a Steinberg square decomposes. The dissertation also investigates the socle of the Steinberg square for a finite group of Lie type, again providing formulas which describe how to find the multiplicity of a simple module in the socle, given information about...
Self-diffusion of particles interacting through a square-well or square-shoulder potential
Wilbertz, H.; Michels, J.; Beijeren, H. van; Leegwater, J.A.
1988-01-01
The diffusion coefficient and velocity autocorrelation function for a fluid of particles interacting through a square-well or square-shoulder potential are calculated from a kinetic theory similar to the Davis-Rice-Sengers theory and the results are compared to those of computer simulations. At low
Multiples least-squares reverse time migration
Zhang, Dongliang; Zhan, Ge; Dai, Wei; Schuster, Gerard T.
2013-01-01
To enhance the image quality, we propose multiples least-squares reverse time migration (MLSRTM) that transforms each hydrophone into a virtual point source with a time history equal to that of the recorded data. Since each recorded trace is treated
Least-squares variance component estimation
Teunissen, P.J.G.; Amiri-Simkooei, A.R.
2007-01-01
Least-squares variance component estimation (LS-VCE) is a simple, flexible and attractive method for the estimation of unknown variance and covariance components. LS-VCE is simple because it is based on the well-known principle of LS; it is flexible because it works with a user-defined weight
Square root approximation to the poisson channel
Tsiatmas, A.; Willems, F.M.J.; Baggen, C.P.M.J.
2013-01-01
Starting from the Poisson model we present a channel model for optical communications, called the Square Root (SR) Channel, in which the noise is additive Gaussian with constant variance. Initially, we prove that for large peak or average power, the transmission rate of a Poisson Channel when coding
Latin square three dimensional gage master
Jones, Lynn L.
1982-01-01
A gage master for coordinate measuring machines has an nxn array of objects distributed in the Z coordinate utilizing the concept of a Latin square experimental design. Using analysis of variance techniques, the invention may be used to identify sources of error in machine geometry and quantify machine accuracy.
Group-wise partial least square regression
Camacho, José; Saccenti, Edoardo
2018-01-01
This paper introduces the group-wise partial least squares (GPLS) regression. GPLS is a new sparse PLS technique where the sparsity structure is defined in terms of groups of correlated variables, similarly to what is done in the related group-wise principal component analysis. These groups are
Clar sextets in square graphene antidot lattices
DEFF Research Database (Denmark)
Petersen, Rene; Pedersen, Thomas Garm; Jauho, Antti-Pekka
2011-01-01
A periodic array of holes transforms graphene from a semimetal into a semiconductor with a band gap tuneable by varying the parameters of the lattice. In earlier work only hexagonal lattices have been treated. Using atomistic models we here investigate the size of the band gap of a square lattice...
Optimistic semi-supervised least squares classification
DEFF Research Database (Denmark)
Krijthe, Jesse H.; Loog, Marco
2017-01-01
The goal of semi-supervised learning is to improve supervised classifiers by using additional unlabeled training examples. In this work we study a simple self-learning approach to semi-supervised learning applied to the least squares classifier. We show that a soft-label and a hard-label variant ...
Iterative methods for weighted least-squares
Energy Technology Data Exchange (ETDEWEB)
Bobrovnikova, E.Y.; Vavasis, S.A. [Cornell Univ., Ithaca, NY (United States)
1996-12-31
A weighted least-squares problem with a very ill-conditioned weight matrix arises in many applications. Because of round-off errors, the standard conjugate gradient method for solving this system does not give the correct answer even after n iterations. In this paper we propose an iterative algorithm based on a new type of reorthogonalization that converges to the solution.
Least-squares model-based halftoning
Pappas, Thrasyvoulos N.; Neuhoff, David L.
1992-08-01
A least-squares model-based approach to digital halftoning is proposed. It exploits both a printer model and a model for visual perception. It attempts to produce an 'optimal' halftoned reproduction, by minimizing the squared error between the response of the cascade of the printer and visual models to the binary image and the response of the visual model to the original gray-scale image. Conventional methods, such as clustered ordered dither, use the properties of the eye only implicitly, and resist printer distortions at the expense of spatial and gray-scale resolution. In previous work we showed that our printer model can be used to modify error diffusion to account for printer distortions. The modified error diffusion algorithm has better spatial and gray-scale resolution than conventional techniques, but produces some well known artifacts and asymmetries because it does not make use of an explicit eye model. Least-squares model-based halftoning uses explicit eye models and relies on printer models that predict distortions and exploit them to increase, rather than decrease, both spatial and gray-scale resolution. We have shown that the one-dimensional least-squares problem, in which each row or column of the image is halftoned independently, can be implemented with the Viterbi's algorithm. Unfortunately, no closed form solution can be found in two dimensions. The two-dimensional least squares solution is obtained by iterative techniques. Experiments show that least-squares model-based halftoning produces more gray levels and better spatial resolution than conventional techniques. We also show that the least- squares approach eliminates the problems associated with error diffusion. Model-based halftoning can be especially useful in transmission of high quality documents using high fidelity gray-scale image encoders. As we have shown, in such cases halftoning can be performed at the receiver, just before printing. Apart from coding efficiency, this approach
Directory of Open Access Journals (Sweden)
Lopez Moris E
2016-06-01
Full Text Available Total thyroidectomy is a surgery that removes all the thyroid tissue from the patient. The suspect of cancer in a thyroid nodule is the most frequent indication and it is presume when previous fine needle puncture is positive or a goiter has significant volume increase or symptomes. Less frequent indications are hyperthyroidism when it is refractory to treatment with Iodine 131 or it is contraindicated, and in cases of symptomatic thyroiditis. The thyroid gland has an important anatomic relation whith the inferior laryngeal nerve and the parathyroid glands, for this reason it is imperative to perform extremely meticulous dissection to recognize each one of these elements and ensure their preservation. It is also essential to maintain strict hemostasis, in order to avoid any postoperative bleeding that could lead to a suffocating neck hematoma, feared complication that represents a surgical emergency and endangers the patient’s life.It is essential to run a formal technique, without skipping steps, and maintain prudence and patience that should rule any surgical act.
Mathematical Construction of Magic Squares Utilizing Base-N Arithmetic
O'Brien, Thomas D.
2006-01-01
Magic squares have been of interest as a source of recreation for over 4,500 years. A magic square consists of a square array of n[squared] positive and distinct integers arranged so that the sum of any column, row, or main diagonal is the same. In particular, an array of consecutive integers from 1 to n[squared] forming an nxn magic square is…
Approximate calculation method for integral of mean square value of nonstationary response
International Nuclear Information System (INIS)
Aoki, Shigeru; Fukano, Azusa
2010-01-01
The response of the structure subjected to nonstationary random vibration such as earthquake excitation is nonstationary random vibration. Calculating method for statistical characteristics of such a response is complicated. Mean square value of the response is usually used to evaluate random response. Integral of mean square value of the response corresponds to total energy of the response. In this paper, a simplified calculation method to obtain integral of mean square value of the response is proposed. As input excitation, nonstationary white noise and nonstationary filtered white noise are used. Integrals of mean square value of the response are calculated for various values of parameters. It is found that the proposed method gives exact value of integral of mean square value of the response.
Constrained least squares regularization in PET
International Nuclear Information System (INIS)
Choudhury, K.R.; O'Sullivan, F.O.
1996-01-01
Standard reconstruction methods used in tomography produce images with undesirable negative artifacts in background and in areas of high local contrast. While sophisticated statistical reconstruction methods can be devised to correct for these artifacts, their computational implementation is excessive for routine operational use. This work describes a technique for rapid computation of approximate constrained least squares regularization estimates. The unique feature of the approach is that it involves no iterative projection or backprojection steps. This contrasts with the familiar computationally intensive algorithms based on algebraic reconstruction (ART) or expectation-maximization (EM) methods. Experimentation with the new approach for deconvolution and mixture analysis shows that the root mean square error quality of estimators based on the proposed algorithm matches and usually dominates that of more elaborate maximum likelihood, at a fraction of the computational effort
Classical square-plus-triangle well fluid
International Nuclear Information System (INIS)
Boghdadi, M.
1984-01-01
A simplified model for the intermolecular-potential function which consists of a hard core and a square-plus-triangle well is proposed. The square width is taken to be lambda 1 -1 and the triangle width is lambda 2 -lambda 1 , where the diameter of the molecules is assumed to be epsilon. Under the restriction that the area under the potential well should be equal to 0.5epsilon, which has its own reason, it is shown that the appropriate choice of lambda 1 and lambda 2 that best mimics the Lennard-Jones (LJ) cut-off results is 1.15 and 1.85 respectively. With this choice for lambda 1 and lambda 2 , the proposed model is effective and satisfactory
Dancoff Correction in Square and Hexagonal Lattices
Energy Technology Data Exchange (ETDEWEB)
Carlvik, I
1966-11-15
This report presents the results of a series of calculations of Dancoff corrections for square and hexagonal rod lattices. The tables cover a wide range of volume ratios and moderator cross sections. The results were utilized for checking the approximative formula of Sauer and also the modification of Bonalumi to Sauer's formula. The modified formula calculates the Dancoff correction with an accuracy of 0.01 - 0.02 in cases of practical interest. Calculations have also been performed on square lattices with an empty gap surrounding the rods. The results demonstrate the error involved in treating this kind of geometry by means of homogenizing the gap and the moderator. The calculations were made on the Ferranti Mercury computer of AB Atomenergi before it was closed down. Since then FORTRAN routines for Dancoff corrections have been written, and a subroutine DASQHE is included in the report.
Elastic least-squares reverse time migration
Feng, Zongcai; Schuster, Gerard T.
2016-01-01
Elastic least-squares reverse time migration (LSRTM) is used to invert synthetic particle-velocity data and crosswell pressure field data. The migration images consist of both the P- and Svelocity perturbation images. Numerical tests on synthetic and field data illustrate the advantages of elastic LSRTM over elastic reverse time migration (RTM). In addition, elastic LSRTM images are better focused and have better reflector continuity than do the acoustic LSRTM images.
Elastic least-squares reverse time migration
Feng, Zongcai
2016-09-06
Elastic least-squares reverse time migration (LSRTM) is used to invert synthetic particle-velocity data and crosswell pressure field data. The migration images consist of both the P- and Svelocity perturbation images. Numerical tests on synthetic and field data illustrate the advantages of elastic LSRTM over elastic reverse time migration (RTM). In addition, elastic LSRTM images are better focused and have better reflector continuity than do the acoustic LSRTM images.
Natural convective heat transfer from square cylinder
Energy Technology Data Exchange (ETDEWEB)
Novomestský, Marcel, E-mail: marcel.novomestsky@fstroj.uniza.sk; Smatanová, Helena, E-mail: helena.smatanova@fstroj.uniza.sk; Kapjor, Andrej, E-mail: andrej.kapjor@fstroj.uniza.sk [University of Žilina, Faculty of Mechanical Engineering, Department of Power Engineering, Univerzitná 1, 010 26 Žilina (Slovakia)
2016-06-30
This article is concerned with natural convective heat transfer from square cylinder mounted on a plane adiabatic base, the cylinders having an exposed cylinder surface according to different horizontal angle. The cylinder receives heat from a radiating heater which results in a buoyant flow. There are many industrial applications, including refrigeration, ventilation and the cooling of electrical components, for which the present study may be applicable.
Least Squares Problems with Absolute Quadratic Constraints
Directory of Open Access Journals (Sweden)
R. Schöne
2012-01-01
Full Text Available This paper analyzes linear least squares problems with absolute quadratic constraints. We develop a generalized theory following Bookstein's conic-fitting and Fitzgibbon's direct ellipse-specific fitting. Under simple preconditions, it can be shown that a minimum always exists and can be determined by a generalized eigenvalue problem. This problem is numerically reduced to an eigenvalue problem by multiplications of Givens' rotations. Finally, four applications of this approach are presented.
A least-squares computational ''tool kit''
International Nuclear Information System (INIS)
Smith, D.L.
1993-04-01
The information assembled in this report is intended to offer a useful computational ''tool kit'' to individuals who are interested in a variety of practical applications for the least-squares method of parameter estimation. The fundamental principles of Bayesian analysis are outlined first and these are applied to development of both the simple and the generalized least-squares conditions. Formal solutions that satisfy these conditions are given subsequently. Their application to both linear and non-linear problems is described in detail. Numerical procedures required to implement these formal solutions are discussed and two utility computer algorithms are offered for this purpose (codes LSIOD and GLSIOD written in FORTRAN). Some simple, easily understood examples are included to illustrate the use of these algorithms. Several related topics are then addressed, including the generation of covariance matrices, the role of iteration in applications of least-squares procedures, the effects of numerical precision and an approach that can be pursued in developing data analysis packages that are directed toward special applications
Advancing Astrophysics with the Square Kilometre Array
Fender, Rob; Govoni, Federica; Green, Jimi; Hoare, Melvin; Jarvis, Matt; Johnston-Hollitt, Melanie; Keane, Evan; Koopmans, Leon; Kramer, Michael; Maartens, Roy; Macquart, Jean-Pierre; Mellema, Garrelt; Oosterloo, Tom; Prandoni, Isabella; Pritchard, Jonathan; Santos, Mario; Seymour, Nick; Stappers, Ben; Staveley-Smith, Lister; Tian, Wen Wu; Umana, Grazia; Wagg, Jeff; Bourke, Tyler L; AASKA14
2015-01-01
In 2014 it was 10 years since the publication of the comprehensive ‘Science with the Square Kilometre Array’ book and 15 years since the first such volume appeared in 1999. In that time numerous and unexpected advances have been made in the fields of astronomy and physics relevant to the capabilities of the Square Kilometre Array (SKA). The SKA itself progressed from an idea to a developing reality with a baselined Phase 1 design (SKA1) and construction planned from 2017. To facilitate the publication of a new, updated science book, which will be relevant to the current astrophysical context, the meeting "Advancing Astrophysics with the Square Kilometre Array" was held in Giardina Naxos, Sicily. Articles were solicited from the community for that meeting to document the scientific advances enabled by the first phase of the SKA and those pertaining to future SKA deployments, with expected gains of 5 times the Phase 1 sensitivity below 350 MHz, about 10 times the Phase 1 sensitivity above 350 MHz and with f...
XAFS study of copper(II) complexes with square planar and square pyramidal coordination geometries
Gaur, A.; Klysubun, W.; Nitin Nair, N.; Shrivastava, B. D.; Prasad, J.; Srivastava, K.
2016-08-01
X-ray absorption fine structure of six Cu(II) complexes, Cu2(Clna)4 2H2O (1), Cu2(ac)4 2H2O (2), Cu2(phac)4 (pyz) (3), Cu2(bpy)2(na)2 H2O (ClO4) (4), Cu2(teen)4(OH)2(ClO4)2 (5) and Cu2(tmen)4(OH)2(ClO4)2 (6) (where ac, phac, pyz, bpy, na, teen, tmen = acetate, phenyl acetate, pyrazole, bipyridine, nicotinic acid, tetraethyethylenediamine, tetramethylethylenediamine, respectively), which were supposed to have square pyramidal and square planar coordination geometries have been investigated. The differences observed in the X-ray absorption near edge structure (XANES) features of the standard compounds having four, five and six coordination geometry points towards presence of square planar and square pyramidal geometry around Cu centre in the studied complexes. The presence of intense pre-edge feature in the spectra of four complexes, 1-4, indicates square pyramidal coordination. Another important XANES feature, present in complexes 5 and 6, is prominent shoulder in the rising part of edge whose intensity decreases in the presence of axial ligands and thus indicates four coordination in these complexes. Ab initio calculations were carried out for square planar and square pyramidal Cu centres to observe the variation of 4p density of states in the presence and absence of axial ligands. To determine the number and distance of scattering atoms around Cu centre in the complexes, EXAFS analysis has been done using the paths obtained from Cu(II) oxide model and an axial Cu-O path from model of a square pyramidal complex. The results obtained from EXAFS analysis have been reported which confirmed the inference drawn from XANES features. Thus, it has been shown that these paths from model of a standard compound can be used to determine the structural parameters for complexes having unknown structure.
Lax-pair operators for squared-sum and squared-difference eigenfunctions
International Nuclear Information System (INIS)
Ichikawa, Yoshihiko; Iino, Kazuhiro.
1984-10-01
Inter-relationship between various representations of the inverse scattering transformation is established by examining eigenfunctions of Lax-pair operators of the sine-Gordon equation and the modified Korteweg-de Vries equation. In particular, it is shown explicitly that there exists Lax-pair operators for the squared-sum and squared-difference eigenfunctions of the Ablowitz-Kaup-Newell-Segur inverse scattering transformation. (author)
Directory of Open Access Journals (Sweden)
Wojciech Rosloniec
2010-01-01
Full Text Available The TLS ESPRIT method is investigated in application to estimation of angular coordinates (angles of arrival of two moving objects at the presence of an external, relatively strong uncorrelated signal. As a radar antenna system, the 32-element uniform linear array (ULA is used. Various computer simulations have been carried out in order to demonstrate good accuracy and high spatial resolution of the TLS ESPRIT method in the scenario outlined above. It is also shown that accuracy and angle resolution can be significantly increased by using the proposed preprocessing (beamforming. The most of simulation results, presented in a graphical form, have been compared to the corresponding equivalent results obtained by using the ESPRIT method and conventional amplitude monopulse method aided by the coherent Doppler filtration.
Leonardo Pisano (Fibonacci) the book of squares
Sigler, L E
1987-01-01
The Book of Squares by Fibonacci is a gem in the mathematical literature and one of the most important mathematical treatises written in the Middle Ages. It is a collection of theorems on indeterminate analysis and equations of second degree which yield, among other results, a solution to a problem proposed by Master John of Palermo to Leonardo at the Court of Frederick II. The book was dedicated and presented to the Emperor at Pisa in 1225. Dating back to the 13th century the book exhibits the early and continued fascination of men with our number system and the relationship among numbers
Least Squares Methods for Equidistant Tree Reconstruction
Fahey, Conor; Hosten, Serkan; Krieger, Nathan; Timpe, Leslie
2008-01-01
UPGMA is a heuristic method identifying the least squares equidistant phylogenetic tree given empirical distance data among $n$ taxa. We study this classic algorithm using the geometry of the space of all equidistant trees with $n$ leaves, also known as the Bergman complex of the graphical matroid for the complete graph $K_n$. We show that UPGMA performs an orthogonal projection of the data onto a maximal cell of the Bergman complex. We also show that the equidistant tree with the least (Eucl...
Magnetics calculations for an ELMO Bumpy square
International Nuclear Information System (INIS)
Santoro, R.T.; Uckan, N.A.; Schmidt, R.J.
1985-01-01
Advanced ELMO Bumpy Torus (EBT) concepts have been studied in an effort to determine the potential for new and different concepts as confinement experiments or as reactors. Several magnetic configurations based on the EBT confinement concept were developed including the ELMO Bumpy Square (EBS). The EBS was selected as a possible candidate for near-term study because of its potential for resolving critical EBT issues, for its desirability as a reactor, and for anticipated contributions to the physics and technology of fusion. This paper summarizes magnetics calculations that were carried out in support of studies to assess the merits of an EBS
Computational logic with square rings of nanomagnets
Arava, Hanu; Derlet, Peter M.; Vijayakumar, Jaianth; Cui, Jizhai; Bingham, Nicholas S.; Kleibert, Armin; Heyderman, Laura J.
2018-06-01
Nanomagnets are a promising low-power alternative to traditional computing. However, the successful implementation of nanomagnets in logic gates has been hindered so far by a lack of reliability. Here, we present a novel design with dipolar-coupled nanomagnets arranged on a square lattice to (i) support transfer of information and (ii) perform logic operations. We introduce a thermal protocol, using thermally active nanomagnets as a means to perform computation. Within this scheme, the nanomagnets are initialized by a global magnetic field and thermally relax on raising the temperature with a resistive heater. We demonstrate error-free transfer of information in chains of up to 19 square rings and we show a high level of reliability with successful gate operations of ∼94% across more than 2000 logic gates. Finally, we present a functionally complete prototype NAND/NOR logic gate that could be implemented for advanced logic operations. Here we support our experiments with simulations of the thermally averaged output and determine the optimal gate parameters. Our approach provides a new pathway to a long standing problem concerning reliability in the use of nanomagnets for computation.
Vapor-liquid equilibrium and critical asymmetry of square well and short square well chain fluids.
Li, Liyan; Sun, Fangfang; Chen, Zhitong; Wang, Long; Cai, Jun
2014-08-07
The critical behavior of square well fluids with variable interaction ranges and of short square well chain fluids have been investigated by grand canonical ensemble Monte Carlo simulations. The critical temperatures and densities were estimated by a finite-size scaling analysis with the help of histogram reweighting technique. The vapor-liquid coexistence curve in the near-critical region was determined using hyper-parallel tempering Monte Carlo simulations. The simulation results for coexistence diameters show that the contribution of |t|(1-α) to the coexistence diameter dominates the singular behavior in all systems investigated. The contribution of |t|(2β) to the coexistence diameter is larger for the system with a smaller interaction range λ. While for short square well chain fluids, longer the chain length, larger the contribution of |t|(2β). The molecular configuration greatly influences the critical asymmetry: a short soft chain fluid shows weaker critical asymmetry than a stiff chain fluid with same chain length.
Quantum mechanical streamlines. I - Square potential barrier
Hirschfelder, J. O.; Christoph, A. C.; Palke, W. E.
1974-01-01
Exact numerical calculations are made for scattering of quantum mechanical particles hitting a square two-dimensional potential barrier (an exact analog of the Goos-Haenchen optical experiments). Quantum mechanical streamlines are plotted and found to be smooth and continuous, to have continuous first derivatives even through the classical forbidden region, and to form quantized vortices around each of the nodal points. A comparison is made between the present numerical calculations and the stationary wave approximation, and good agreement is found between both the Goos-Haenchen shifts and the reflection coefficients. The time-independent Schroedinger equation for real wavefunctions is reduced to solving a nonlinear first-order partial differential equation, leading to a generalization of the Prager-Hirschfelder perturbation scheme. Implications of the hydrodynamical formulation of quantum mechanics are discussed, and cases are cited where quantum and classical mechanical motions are identical.
Square well approximation to the optical potential
International Nuclear Information System (INIS)
Jain, A.K.; Gupta, M.C.; Marwadi, P.R.
1976-01-01
Approximations for obtaining T-matrix elements for a sum of several potentials in terms of T-matrices for individual potentials are studied. Based on model calculations for S-wave for a sum of two separable non-local potentials of Yukawa type form factors and a sum of two delta function potentials, it is shown that the T-matrix for a sum of several potentials can be approximated satisfactorily over all the energy regions by the sum of T-matrices for individual potentials. Based on this, an approximate method for finding T-matrix for any local potential by approximating it by a sum of suitable number of square wells is presented. This provides an interesting way to calculate the T-matrix for any arbitary potential in terms of Bessel functions to a good degree of accuracy. The method is applied to the Saxon-Wood potentials and good agreement with exact results is found. (author)
ANYOLS, Least Square Fit by Stepwise Regression
International Nuclear Information System (INIS)
Atwoods, C.L.; Mathews, S.
1986-01-01
Description of program or function: ANYOLS is a stepwise program which fits data using ordinary or weighted least squares. Variables are selected for the model in a stepwise way based on a user- specified input criterion or a user-written subroutine. The order in which variables are entered can be influenced by user-defined forcing priorities. Instead of stepwise selection, ANYOLS can try all possible combinations of any desired subset of the variables. Automatic output for the final model in a stepwise search includes plots of the residuals, 'studentized' residuals, and leverages; if the model is not too large, the output also includes partial regression and partial leverage plots. A data set may be re-used so that several selection criteria can be tried. Flexibility is increased by allowing the substitution of user-written subroutines for several default subroutines
Optimally weighted least-squares steganalysis
Ker, Andrew D.
2007-02-01
Quantitative steganalysis aims to estimate the amount of payload in a stego object, and such estimators seem to arise naturally in steganalysis of Least Significant Bit (LSB) replacement in digital images. However, as with all steganalysis, the estimators are subject to errors, and their magnitude seems heavily dependent on properties of the cover. In very recent work we have given the first derivation of estimation error, for a certain method of steganalysis (the Least-Squares variant of Sample Pairs Analysis) of LSB replacement steganography in digital images. In this paper we make use of our theoretical results to find an improved estimator and detector. We also extend the theoretical analysis to another (more accurate) steganalysis estimator (Triples Analysis) and hence derive an improved version of that estimator too. Experimental results show that the new steganalyzers have improved accuracy, particularly in the difficult case of never-compressed covers.
The Square Kilometre Array: An Engineering Perspective
Hall, Peter J
2005-01-01
This volume is an up-to-date and comprehensive overview of the engineering of the Square Kilometre Array (SKA), a revolutionary instrument which will be the world’s largest radio telescope. Expected to be completed by 2020, the SKA will be a pre-eminent tool in probing the Early Universe and in enhancing greatly the discovery potential of radio astronomy in many other fields. This book, containing 36 refereed papers written by leaders in SKA engineering, has been compiled by the International SKA Project Office and is the only contemporary compendium available. It features papers dealing with pivotal technologies such as antennas, RF systems and data transport. As well, overviews of important SKA demonstrator instruments and key system design issues are included. Practising professionals, and students interested in next-generation telescopes, will find this book an invaluable reference.
Least square regularized regression in sum space.
Xu, Yong-Li; Chen, Di-Rong; Li, Han-Xiong; Liu, Lu
2013-04-01
This paper proposes a least square regularized regression algorithm in sum space of reproducing kernel Hilbert spaces (RKHSs) for nonflat function approximation, and obtains the solution of the algorithm by solving a system of linear equations. This algorithm can approximate the low- and high-frequency component of the target function with large and small scale kernels, respectively. The convergence and learning rate are analyzed. We measure the complexity of the sum space by its covering number and demonstrate that the covering number can be bounded by the product of the covering numbers of basic RKHSs. For sum space of RKHSs with Gaussian kernels, by choosing appropriate parameters, we tradeoff the sample error and regularization error, and obtain a polynomial learning rate, which is better than that in any single RKHS. The utility of this method is illustrated with two simulated data sets and five real-life databases.
Multiples least-squares reverse time migration
Zhang, Dongliang
2013-01-01
To enhance the image quality, we propose multiples least-squares reverse time migration (MLSRTM) that transforms each hydrophone into a virtual point source with a time history equal to that of the recorded data. Since each recorded trace is treated as a virtual source, knowledge of the source wavelet is not required. Numerical tests on synthetic data for the Sigsbee2B model and field data from Gulf of Mexico show that MLSRTM can improve the image quality by removing artifacts, balancing amplitudes, and suppressing crosstalk compared to standard migration of the free-surface multiples. The potential liability of this method is that multiples require several roundtrips between the reflector and the free surface, so that high frequencies in the multiples are attenuated compared to the primary reflections. This can lead to lower resolution in the migration image compared to that computed from primaries.
Tensor hypercontraction. II. Least-squares renormalization
Parrish, Robert M.; Hohenstein, Edward G.; Martínez, Todd J.; Sherrill, C. David
2012-12-01
The least-squares tensor hypercontraction (LS-THC) representation for the electron repulsion integral (ERI) tensor is presented. Recently, we developed the generic tensor hypercontraction (THC) ansatz, which represents the fourth-order ERI tensor as a product of five second-order tensors [E. G. Hohenstein, R. M. Parrish, and T. J. Martínez, J. Chem. Phys. 137, 044103 (2012)], 10.1063/1.4732310. Our initial algorithm for the generation of the THC factors involved a two-sided invocation of overlap-metric density fitting, followed by a PARAFAC decomposition, and is denoted PARAFAC tensor hypercontraction (PF-THC). LS-THC supersedes PF-THC by producing the THC factors through a least-squares renormalization of a spatial quadrature over the otherwise singular 1/r12 operator. Remarkably, an analytical and simple formula for the LS-THC factors exists. Using this formula, the factors may be generated with O(N^5) effort if exact integrals are decomposed, or O(N^4) effort if the decomposition is applied to density-fitted integrals, using any choice of density fitting metric. The accuracy of LS-THC is explored for a range of systems using both conventional and density-fitted integrals in the context of MP2. The grid fitting error is found to be negligible even for extremely sparse spatial quadrature grids. For the case of density-fitted integrals, the additional error incurred by the grid fitting step is generally markedly smaller than the underlying Coulomb-metric density fitting error. The present results, coupled with our previously published factorizations of MP2 and MP3, provide an efficient, robust O(N^4) approach to both methods. Moreover, LS-THC is generally applicable to many other methods in quantum chemistry.
Multiplier less high-speed squaring circuit for binary numbers
Sethi, Kabiraj; Panda, Rutuparna
2015-03-01
The squaring operation is important in many applications in signal processing, cryptography etc. In general, squaring circuits reported in the literature use fast multipliers. A novel idea of a squaring circuit without using multipliers is proposed in this paper. Ancient Indian method used for squaring decimal numbers is extended here for binary numbers. The key to our success is that no multiplier is used. Instead, one squaring circuit is used. The hardware architecture of the proposed squaring circuit is presented. The design is coded in VHDL and synthesised and simulated in Xilinx ISE Design Suite 10.1 (Xilinx Inc., San Jose, CA, USA). It is implemented in Xilinx Vertex 4vls15sf363-12 device (Xilinx Inc.). The results in terms of time delay and area is compared with both modified Booth's algorithm and squaring circuit using Vedic multipliers. Our proposed squaring circuit seems to have better performance in terms of both speed and area.
Evaluating Outlier Identification Tests: Mahalanobis "D" Squared and Comrey "Dk."
Rasmussen, Jeffrey Lee
1988-01-01
A Monte Carlo simulation was used to compare the Mahalanobis "D" Squared and the Comrey "Dk" methods of detecting outliers in data sets. Under the conditions investigated, the "D" Squared technique was preferable as an outlier removal statistic. (SLD)
Testing the gravitational inverse-square law
International Nuclear Information System (INIS)
Adelberger, Eric; Heckel, B.; Hoyle, C.D.
2005-01-01
If the universe contains more than three spatial dimensions, as many physicists believe, our current laws of gravity should break down at small distances. When Isaac Newton realized that the acceleration of the Moon as it orbited around the Earth could be related to the acceleration of an apple as it fell to the ground, it was the first time that two seemingly unrelated physical phenomena had been 'unified'. The quest to unify all the forces of nature is one that still keeps physicists busy today. Newton showed that the gravitational attraction between two point bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them. Newton's theory, which assumes that the gravitational force acts instantaneously, remained essentially unchallenged for roughly two centuries until Einstein proposed the general theory of relativity in 1915. Einstein's radical new theory made gravity consistent with the two basic ideas of relativity: the world is 4D - the three directions of space combined with time - and no physical effect can travel faster than light. The theory of general relativity states that gravity is not a force in the usual sense but a consequence of the curvature of this space-time produced by mass or energy. However, in the limit of low velocities and weak gravitational fields, Einstein's theory still predicts that the gravitational force between two point objects obeys an inverse-square law. One of the outstanding challenges in physics is to finish what Newton started and achieve the ultimate 'grand unification' - to unify gravity with the other three fundamental forces (the electromagnetic force, and the strong and weak nuclear forces) into a single quantum theory. In string theory - one of the leading candidates for an ultimate theory - the fundamental entities of nature are 1D strings and higher-dimensional objects called 'branes', rather than the point-like particles we are familiar with. String
Multisource Least-squares Reverse Time Migration
Dai, Wei
2012-12-01
Least-squares migration has been shown to be able to produce high quality migration images, but its computational cost is considered to be too high for practical imaging. In this dissertation, a multisource least-squares reverse time migration algorithm (LSRTM) is proposed to increase by up to 10 times the computational efficiency by utilizing the blended sources processing technique. There are three main chapters in this dissertation. In Chapter 2, the multisource LSRTM algorithm is implemented with random time-shift and random source polarity encoding functions. Numerical tests on the 2D HESS VTI data show that the multisource LSRTM algorithm suppresses migration artifacts, balances the amplitudes, improves image resolution, and reduces crosstalk noise associated with the blended shot gathers. For this example, multisource LSRTM is about three times faster than the conventional RTM method. For the 3D example of the SEG/EAGE salt model, with comparable computational cost, multisource LSRTM produces images with more accurate amplitudes, better spatial resolution, and fewer migration artifacts compared to conventional RTM. The empirical results suggest that the multisource LSRTM can produce more accurate reflectivity images than conventional RTM does with similar or less computational cost. The caveat is that LSRTM image is sensitive to large errors in the migration velocity model. In Chapter 3, the multisource LSRTM algorithm is implemented with frequency selection encoding strategy and applied to marine streamer data, for which traditional random encoding functions are not applicable. The frequency-selection encoding functions are delta functions in the frequency domain, so that all the encoded shots have unique non-overlapping frequency content. Therefore, the receivers can distinguish the wavefield from each shot according to the frequencies. With the frequency-selection encoding method, the computational efficiency of LSRTM is increased so that its cost is
Delayed ripple counter simplifies square-root computation
Cliff, R.
1965-01-01
Ripple subtract technique simplifies the logic circuitry required in a binary computing device to derive the square root of a number. Successively higher numbers are subtracted from a register containing the number out of which the square root is to be extracted. The last number subtracted will be the closest integer to the square root of the number.
Skeletonized Least Squares Wave Equation Migration
Zhan, Ge
2010-10-17
The theory for skeletonized least squares wave equation migration (LSM) is presented. The key idea is, for an assumed velocity model, the source‐side Green\\'s function and the geophone‐side Green\\'s function are computed by a numerical solution of the wave equation. Only the early‐arrivals of these Green\\'s functions are saved and skeletonized to form the migration Green\\'s function (MGF) by convolution. Then the migration image is obtained by a dot product between the recorded shot gathers and the MGF for every trial image point. The key to an efficient implementation of iterative LSM is that at each conjugate gradient iteration, the MGF is reused and no new finitedifference (FD) simulations are needed to get the updated migration image. It is believed that this procedure combined with phase‐encoded multi‐source technology will allow for the efficient computation of wave equation LSM images in less time than that of conventional reverse time migration (RTM).
Elastic least-squares reverse time migration
Feng, Zongcai
2017-03-08
We use elastic least-squares reverse time migration (LSRTM) to invert for the reflectivity images of P- and S-wave impedances. Elastic LSRTMsolves the linearized elastic-wave equations for forward modeling and the adjoint equations for backpropagating the residual wavefield at each iteration. Numerical tests on synthetic data and field data reveal the advantages of elastic LSRTM over elastic reverse time migration (RTM) and acoustic LSRTM. For our examples, the elastic LSRTM images have better resolution and amplitude balancing, fewer artifacts, and less crosstalk compared with the elastic RTM images. The images are also better focused and have better reflector continuity for steeply dipping events compared to the acoustic LSRTM images. Similar to conventional leastsquares migration, elastic LSRTM also requires an accurate estimation of the P- and S-wave migration velocity models. However, the problem remains that, when there are moderate errors in the velocity model and strong multiples, LSRTMwill produce migration noise stronger than that seen in the RTM images.
Multilevel weighted least squares polynomial approximation
Haji-Ali, Abdul-Lateef
2017-06-30
Weighted least squares polynomial approximation uses random samples to determine projections of functions onto spaces of polynomials. It has been shown that, using an optimal distribution of sample locations, the number of samples required to achieve quasi-optimal approximation in a given polynomial subspace scales, up to a logarithmic factor, linearly in the dimension of this space. However, in many applications, the computation of samples includes a numerical discretization error. Thus, obtaining polynomial approximations with a single level method can become prohibitively expensive, as it requires a sufficiently large number of samples, each computed with a sufficiently small discretization error. As a solution to this problem, we propose a multilevel method that utilizes samples computed with different accuracies and is able to match the accuracy of single-level approximations with reduced computational cost. We derive complexity bounds under certain assumptions about polynomial approximability and sample work. Furthermore, we propose an adaptive algorithm for situations where such assumptions cannot be verified a priori. Finally, we provide an efficient algorithm for the sampling from optimal distributions and an analysis of computationally favorable alternative distributions. Numerical experiments underscore the practical applicability of our method.
Elastic least-squares reverse time migration
Feng, Zongcai; Schuster, Gerard T.
2017-01-01
We use elastic least-squares reverse time migration (LSRTM) to invert for the reflectivity images of P- and S-wave impedances. Elastic LSRTMsolves the linearized elastic-wave equations for forward modeling and the adjoint equations for backpropagating the residual wavefield at each iteration. Numerical tests on synthetic data and field data reveal the advantages of elastic LSRTM over elastic reverse time migration (RTM) and acoustic LSRTM. For our examples, the elastic LSRTM images have better resolution and amplitude balancing, fewer artifacts, and less crosstalk compared with the elastic RTM images. The images are also better focused and have better reflector continuity for steeply dipping events compared to the acoustic LSRTM images. Similar to conventional leastsquares migration, elastic LSRTM also requires an accurate estimation of the P- and S-wave migration velocity models. However, the problem remains that, when there are moderate errors in the velocity model and strong multiples, LSRTMwill produce migration noise stronger than that seen in the RTM images.
Phase transition in a modified square Josephson-junction array
Han, J
1999-01-01
We study the phase transition in a modified square proximity-coupled Josephson-junction array with small superconducting islands at the center of each plaquette. We find that the modified square array undergoes a Kosterlitz-Thouless-Berezinskii-like phase transition, but at a lower temperature than the simple square array with the same single-junction critical current. The IV characteristics, as well as the phase transition, resemble qualitatively those of a disordered simple square array. The effects of the presence of the center islands in the modified square array are discussed.
Influence of the least-squares phase on optical vortices in strongly scintillated beams
CSIR Research Space (South Africa)
Chen, M
2009-06-01
Full Text Available , the average total number of vortices is reduced further. However, the reduction becomes smaller for each succes- sive step. This indicates that the ability of getting rid of optical vortices by removing the least-squares phase becomes progressively less...
Production of a square geometry Americium standard source for use with photodiodes
Energy Technology Data Exchange (ETDEWEB)
Costa, Priscila; Geraldo, Bianca; Raele, Marcus P.; Marumo, Júlio T.; Vicente, Roberto; Zahn, Guilherme S.; Genezini, Frederico A., E-mail: priscila3.costa@usp.br, E-mail: fredzini@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)
2017-07-01
In the development of a thermal neutron detector using a square photodiode and a thin boron film, a radioactive calibration source with the same geometry was needed. An americium-243 standard source was produced by electrodeposition aiming at the calibration of a PIN-type silicon photodiode with a detection area of 10 x 10 mm{sup 2}. To produce the samples two tests were performed. In the first test, a square stainless steel plate (10 x 10 mm{sup 2}) was fixed on the surface of the conventional plate, which was removed after deposition. To reduce the loss of activity of the source, in the second test nail polish was applied on the silver plate leaving only an area of 10 x 10 mm{sup 2} without varnish coating. Once the electrodeposition process was completed, the activity concentration measurement was performed by alpha particle spectrometry. The first method presented a lower activity when compared to the total activity of Am-243 added initially. For the second method, the total activity was concentrate in the exposed square region (without nail polish). The results showed that it is possible to obtain a square geometry source; furthermore, the surrounding nail polish was not contaminated by {sup 243}Am. The comparison of these two approaches indicated that the second method was more efficient as it was possible to concentrate all the americium activity in the delimited square area. (author)
New approach to breast cancer CAD using partial least squares and kernel-partial least squares
Land, Walker H., Jr.; Heine, John; Embrechts, Mark; Smith, Tom; Choma, Robert; Wong, Lut
2005-04-01
Breast cancer is second only to lung cancer as a tumor-related cause of death in women. Currently, the method of choice for the early detection of breast cancer is mammography. While sensitive to the detection of breast cancer, its positive predictive value (PPV) is low, resulting in biopsies that are only 15-34% likely to reveal malignancy. This paper explores the use of two novel approaches called Partial Least Squares (PLS) and Kernel-PLS (K-PLS) to the diagnosis of breast cancer. The approach is based on optimization for the partial least squares (PLS) algorithm for linear regression and the K-PLS algorithm for non-linear regression. Preliminary results show that both the PLS and K-PLS paradigms achieved comparable results with three separate support vector learning machines (SVLMs), where these SVLMs were known to have been trained to a global minimum. That is, the average performance of the three separate SVLMs were Az = 0.9167927, with an average partial Az (Az90) = 0.5684283. These results compare favorably with the K-PLS paradigm, which obtained an Az = 0.907 and partial Az = 0.6123. The PLS paradigm provided comparable results. Secondly, both the K-PLS and PLS paradigms out performed the ANN in that the Az index improved by about 14% (Az ~ 0.907 compared to the ANN Az of ~ 0.8). The "Press R squared" value for the PLS and K-PLS machine learning algorithms were 0.89 and 0.9, respectively, which is in good agreement with the other MOP values.
Space and protest: A tale of two Egyptian squares
Mohamed, A.A.; Van Nes, A.; Salheen, M.A.
2015-01-01
Protests and revolts take place in public space. How they can be controlled or how protests develop depend on the physical layout of the built environment. This study reveals the relationship between urban space and protest for two Egyptian squares: Tahrir Square and Rabaa Al-Adawiya in Cairo. For analysis, the research uses space syntax method. The results of this analysis are then compared with descriptions of the protest behaviour. As it turns out, the spatial properties of Tahrir square s...
Liu, L. H.; Tan, J. Y.
2007-02-01
A least-squares collocation meshless method is employed for solving the radiative heat transfer in absorbing, emitting and scattering media. The least-squares collocation meshless method for radiative transfer is based on the discrete ordinates equation. A moving least-squares approximation is applied to construct the trial functions. Except for the collocation points which are used to construct the trial functions, a number of auxiliary points are also adopted to form the total residuals of the problem. The least-squares technique is used to obtain the solution of the problem by minimizing the summation of residuals of all collocation and auxiliary points. Three numerical examples are studied to illustrate the performance of this new solution method. The numerical results are compared with the other benchmark approximate solutions. By comparison, the results show that the least-squares collocation meshless method is efficient, accurate and stable, and can be used for solving the radiative heat transfer in absorbing, emitting and scattering media.
Model of directed lines for square ice with second-neighbor and third-neighbor interactions
Kirov, Mikhail V.
2018-02-01
The investigation of the properties of nanoconfined systems is one of the most rapidly developing scientific fields. Recently it has been established that water monolayer between two graphene sheets forms square ice. Because of the energetic disadvantage, in the structure of the square ice there are no longitudinally arranged molecules. The result is that the structure is formed by unidirectional straight-lines of hydrogen bonds only. A simple but accurate discrete model of square ice with second-neighbor and third-neighbor interactions is proposed. According to this model, the ground state includes all configurations which do not contain three neighboring unidirectional chains of hydrogen bonds. Each triplet increases the energy by the same value. This new model differs from an analogous model with long-range interactions where in the ground state all neighboring chains are antiparallel. The new model is suitable for the corresponding system of point electric (and magnetic) dipoles on the square lattice. It allows separately estimating the different contributions to the total binding energy and helps to understand the properties of infinite monolayers and finite nanostructures. Calculations of the binding energy for square ice and for point dipole system are performed using the packages TINKER and LAMMPS.
International Nuclear Information System (INIS)
Liu, L.H.; Tan, J.Y.
2007-01-01
A least-squares collocation meshless method is employed for solving the radiative heat transfer in absorbing, emitting and scattering media. The least-squares collocation meshless method for radiative transfer is based on the discrete ordinates equation. A moving least-squares approximation is applied to construct the trial functions. Except for the collocation points which are used to construct the trial functions, a number of auxiliary points are also adopted to form the total residuals of the problem. The least-squares technique is used to obtain the solution of the problem by minimizing the summation of residuals of all collocation and auxiliary points. Three numerical examples are studied to illustrate the performance of this new solution method. The numerical results are compared with the other benchmark approximate solutions. By comparison, the results show that the least-squares collocation meshless method is efficient, accurate and stable, and can be used for solving the radiative heat transfer in absorbing, emitting and scattering media
Directory of Open Access Journals (Sweden)
Reza Ezzati
2014-08-01
Full Text Available In this paper, we propose the least square method for computing the positive solution of a non-square fully fuzzy linear system. To this end, we use Kaffman' arithmetic operations on fuzzy numbers \\cite{17}. Here, considered existence of exact solution using pseudoinverse, if they are not satisfy in positive solution condition, we will compute fuzzy vector core and then we will obtain right and left spreads of positive fuzzy vector by introducing constrained least squares problem. Using our proposed method, non-square fully fuzzy linear system of equations always has a solution. Finally, we illustrate the efficiency of proposed method by solving some numerical examples.
The nonabelian tensor square of a bieberbach group with ...
African Journals Online (AJOL)
The main objective of this paper is to compute the nonabelian tensor square of one Bieberbach group with elementary abelian 2-group point group of dimension three by using the computational method of the nonabelian tensor square for polycyclic groups. The finding of the computation showed that the nonabelian tensor ...
Your Chi-Square Test Is Statistically Significant: Now What?
Sharpe, Donald
2015-01-01
Applied researchers have employed chi-square tests for more than one hundred years. This paper addresses the question of how one should follow a statistically significant chi-square test result in order to determine the source of that result. Four approaches were evaluated: calculating residuals, comparing cells, ransacking, and partitioning. Data…
Space and protest : A tale of two Egyptian squares
Mohamed, A.A.; Van Nes, A.; Salheen, M.A.
2015-01-01
Protests and revolts take place in public space. How they can be controlled or how protests develop depend on the physical layout of the built environment. This study reveals the relationship between urban space and protest for two Egyptian squares: Tahrir Square and Rabaa Al-Adawiya in Cairo. For
Least-squares reverse time migration of multiples
Zhang, Dongliang; Schuster, Gerard T.
2013-01-01
The theory of least-squares reverse time migration of multiples (RTMM) is presented. In this method, least squares migration (LSM) is used to image free-surface multiples where the recorded traces are used as the time histories of the virtual
TINGKAT KEPUASAN PELANGGAN TERHADAP PELAYANAN DI KFC MAKASSAR TOWN SQUARE
RAMADHANI, IRMA
2017-01-01
2017 Penelitian ini bertujuan untuk mengetahui tingkat kepuasan pelanggan terhadap pelayanan di KFC Makassar Town Square. Penelitian ini dilaksanakan terhadap pelanggan KFC Makassar Town Square yang telah bertransaksi lebih dari satu kali. Penelitian ini merupakan penelitian kuantitatif deskriptif dengan mendeskripsikan atau menggambarkan tentang tingkat kepuasan pelanggan terhadap pelayanan. Jumlah sampel penelitian 83 pelanggan KFC Makassar Town. Analisis data menggunak...
Solution of a Complex Least Squares Problem with Constrained Phase.
Bydder, Mark
2010-12-30
The least squares solution of a complex linear equation is in general a complex vector with independent real and imaginary parts. In certain applications in magnetic resonance imaging, a solution is desired such that each element has the same phase. A direct method for obtaining the least squares solution to the phase constrained problem is described.
note: The least square nucleolus is a general nucleolus
Elisenda Molina; Juan Tejada
2000-01-01
This short note proves that the least square nucleolus (Ruiz et al. (1996)) and the lexicographical solution (Sakawa and Nishizaki (1994)) select the same imputation in each game with nonempty imputation set. As a consequence the least square nucleolus is a general nucleolus (Maschler et al. (1992)).
On root mean square approximation by exponential functions
Sharipov, Ruslan
2014-01-01
The problem of root mean square approximation of a square integrable function by finite linear combinations of exponential functions is considered. It is subdivided into linear and nonlinear parts. The linear approximation problem is solved. Then the nonlinear problem is studied in some particular example.
Application of least-squares method to decay heat evaluation
International Nuclear Information System (INIS)
Schmittroth, F.; Schenter, R.E.
1976-01-01
Generalized least-squares methods are applied to decay-heat experiments and summation calculations to arrive at evaluated values and uncertainties for the fission-product decay-heat from the thermal fission of 235 U. Emphasis is placed on a proper treatment of both statistical and correlated uncertainties in the least-squares method
Directory of Open Access Journals (Sweden)
Shiqi Zhou
2013-10-01
Full Text Available Monte Carlo simulations in the canonical ensemble are performed for fluid with potential consisting of a square-well plus a square-barrier to obtain thermodynamic properties such as pressure, excess energy, constant volume excess heat capacity, and excess chemical potential, and structural property such as radial distribution function. The simulations cover a wide density range for the fluid phase, several temperatures, and different combinations of the parameters defining the potential. These simulation data have been used to test performances of a coupling parameter series expansion (CPSE recently proposed by one of the authors [S. Zhou, Phys. Rev. E 74, 031119 (2006], and a traditional 2nd-order high temperature series expansion (HTSE based on a macroscopic compressibility approximation (MAC used with confidence since its introduction in 1967. It is found that (i the MCA-based 2nd-order HTSE unexpectedly and depressingly fails for most situations investigated, and the present simulation results can serve well as strict criteria for testing liquid state theories. (ii The CPSE perturbation scheme is shown to be capable of predicting very accurately most of the thermodynamic properties simulated, but the most appropriate level of truncating the CPSE differs and depends on the range of the potential to be calculated; in particular, the shorter the potential range is, the higher the most appropriate truncating level can be, and along with rising of the potential range the performance of the CPSE perturbation scheme will decrease at higher truncating level. (iii The CPSE perturbation scheme can calculate satisfactorily bulk fluid rdf, and such calculations can be done for all fluid states of the whole phase diagram. (iv The CPSE is a convergent series at higher temperatures, but show attribute of asymptotic series at lower temperatures, and as a result, the surest asymptotic value occurs at lower-order truncation.
Enumeration of self-avoiding walks on the square lattice
International Nuclear Information System (INIS)
Jensen, Iwan
2004-01-01
We describe a new algorithm for the enumeration of self-avoiding walks on the square lattice. Using up to 128 processors on a HP Alpha server cluster we have enumerated the number of self-avoiding walks on the square lattice to length 71. Series for the metric properties of mean-square end-to-end distance, mean-square radius of gyration and mean-square distance of monomers from the end points have been derived to length 59. An analysis of the resulting series yields accurate estimates of the critical exponents γ and ν confirming predictions of their exact values. Likewise we obtain accurate amplitude estimates yielding precise values for certain universal amplitude combinations. Finally we report on an analysis giving compelling evidence that the leading non-analytic correction-to-scaling exponent Δ 1 = 3/2
Spectrum unfolding by the least-squares methods
International Nuclear Information System (INIS)
Perey, F.G.
1977-01-01
The method of least squares is briefly reviewed, and the conditions under which it may be used are stated. From this analysis, a least-squares approach to the solution of the dosimetry neutron spectrum unfolding problem is introduced. The mathematical solution to this least-squares problem is derived from the general solution. The existence of this solution is analyzed in some detail. A chi 2 -test is derived for the consistency of the input data which does not require the solution to be obtained first. The fact that the problem is technically nonlinear, but should be treated in general as a linear one, is argued. Therefore, the solution should not be obtained by iteration. Two interpretations are made for the solution of the code STAY'SL, which solves this least-squares problem. The relationship of the solution to this least-squares problem to those obtained currently by other methods of solving the dosimetry neutron spectrum unfolding problem is extensively discussed. It is shown that the least-squares method does not require more input information than would be needed by current methods in order to estimate the uncertainties in their solutions. From this discussion it is concluded that the proposed least-squares method does provide the best complete solution, with uncertainties, to the problem as it is understood now. Finally, some implications of this method are mentioned regarding future work required in order to exploit its potential fully
Energy Technology Data Exchange (ETDEWEB)
Park, Chang Je [Sejong Univ., Seoul (Korea, Republic of); Alkhatee, Sari; Roh, Gyuhong; Lee, Byungchul [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2014-05-15
Dose absorption and energy absorption buildup factors are widely used in the shielding analysis. The dose rate of the medium is main concern in the dose buildup factor, however energy absorption is an important parameter in the energy buildup factors. ANSI/ANS-6.4.3-1991 standard data is widely used based on interpolation and extrapolation by means of an approximation method. Recently, Yoshida's geometric progression (GP) formulae are also popular and it is already implemented in QAD code. In the QAD code, two buildup factors are notated as DOSE for standard air exposure response and ENG for the response of the energy absorbed in the material itself. In this paper, a new least square fitting method is suggested to obtain a reliable buildup factors proposed since 1991. Total 4 datasets of air exposure buildup factors are used for evaluation including ANSI/ANS-6.4.3-1991, Taylor, Berger, and GP data. The standard deviation of the fitted data are analyzed based on the results. A new reverse least square fitting method is proposed in this study in order to reduce the fitting uncertainties. It adapts an inverse function rather than the original function by the distribution slope of dataset. Some quantitative comparisons are provided for concrete and lead in this paper, too. This study is focused on the least square fitting of existing buildup factors to be utilized in the point-kernel code for radiation shielding analysis. The inverse least square fitting method is suggested to obtain more reliable results of concave shaped dataset such as concrete. In the concrete case, the variance and residue are decreased significantly, too. However, the convex shaped case of lead can be applied to the usual least square fitting method. In the future, more datasets will be tested by using the least square fitting. And the fitted data could be implemented to the existing point-kernel codes.
TAHRIR SQUARE: A Narrative of a Public Space
Directory of Open Access Journals (Sweden)
Hussam Hussein Salama
2013-03-01
Full Text Available This paper investigates the patterns of public discourse that occurred in Tahrir Square during the 18 days of the Egyptian Revolution. For protestors Tahrir Square became an urban utopia, a place of community engagement, collective projects, social discourse, and most importantly, freedom of speech and expression. This paper traces these forms of spatial adaptation, and the patterns of social organization and discourse that emerged in the square during that period. The paper builds on Henri Lefebvre’s interpretation of space and his three dimensional conceptualization: the perceived, the conceived, and the lived.
The circumference of the square of a connected graph
DEFF Research Database (Denmark)
Brandt, S.; Muttel, J.; Rautenbach, D.
2014-01-01
The celebrated result of Fleischner states that the square of every 2-connected graph is Hamiltonian. We investigate what happens if the graph is just connected. For every n a parts per thousand yen 3, we determine the smallest length c(n) of a longest cycle in the square of a connected graph of ...... of order n and show that c(n) is a logarithmic function in n. Furthermore, for every c a parts per thousand yen 3, we characterize the connected graphs of largest order whose square contains no cycle of length at least c....
Radix-16 Combined Division and Square Root Unit
DEFF Research Database (Denmark)
Nannarelli, Alberto
2011-01-01
Division and square root, based on the digitrecurrence algorithm, can be implemented in a combined unit. Several implementations of combined division/square root units have been presented mostly for radices 2 and 4. Here, we present a combined radix-16 unit obtained by overlapping two radix-4...... result digit selection functions, as it is normally done for division only units. The latency of the unit is reduced by retiming and low power methods are applied as well. The proposed unit is compared to a radix-4 combined division/square root unit, and to a radix-16 unit, obtained by cascading two...
Directory of Open Access Journals (Sweden)
Orlando Díaz Tabares
1997-04-01
Full Text Available Se realizó un estudio longitudinal, descriptivo y retrospectivo con el objetivo de conocer el comportamiento de la incapacidad permanente para el trabajo en el municipio "San Cristóbal" durante el decenio 1982-1991, y se aplicó el método de encuesta por el que se recogieron datos que fueron extraídos del modelo oficial de peritaje médico laboral y de la entrevista con el peritado. Los resultados fueron plasmados en tablas de contingencias donde se relacionan las variables por cada año estudiado, y se aplicó la prueba estadística de chi cuadrado. El número de individuos dictaminados con incapacidad laboral total fue de 693; predominó en reportes el año 1988 con 114 casos y muy discretamente el sexo femenino sobre el masculino, el grupo etáreo de 45 a 54 años con 360 casos y la artrosis como entidad valorada por ortopedia, con análisis estadísticos significativos. No resultó estadísticamente significativo, el predominio de la hipertensión arterial sistémica entre las entidades valoradas por la especialidad de medicina interna como causas de incapacidad laboral. Fue muy significativa la variación del número de dictaminados por la comisión en cada uno de los años estudiados y que el porcentaje de ellos que se encontraban realizando trabajos que demandan esfuerzo físico de moderado a intenso al momento de aplicar la encuesta, ascendió al 64,9.A longitudinal, descriptive and retrospective study was conducted in order to know the behavior of permanent labor disability at the municipality of San Cristóbal during 1982-1991. A survey was done to collect data taken from the official model of medical inspections and from the interview with the disabled worker. The results were shown in contingency tables where the variables are related by every year studied. The chi square statistical test was applied. The number of individuals with labor disability was 693. As for reports, the year 1988 predominated with 114. There was a discreet
From Moon-fall to motions under inverse square laws
International Nuclear Information System (INIS)
Foong, S K
2008-01-01
The motion of two bodies, along a straight line, under the inverse square law of gravity is considered in detail, progressing from simpler cases to more complex ones: (a) one body fixed and one free, (b) both bodies free and identical mass, (c) both bodies free and different masses and (d) the inclusion of electrostatic forces for both bodies free and different masses. The equations of motion (EOM) are derived starting from Newton's second law or from conservation of energy. They are then reduced to dimensionless EOM using appropriate scales for time and distance. Solutions of the dimensionless EOM as well as the original EOM are given. The time interval for the bodies to fall is expressed as a function of the distance fallen. Formulae for the inverse were obtained. The coalescence times for the different cases are (a) π/2√2 √(L 3 /(Gm 1 )) where L is the initial separation of the two bodies and m 1 is the mass of the fixed body, (b) and (c) t=π/2√2 √(L 3 /(Gm T )) where m T is the total mass of the two bodies and (d) t=π/2√2 √(L 3 /[Gm T (1-Λ)]) where Λ=(kq 1 q 2 )/(Gm 1 m 2 ) and is a measure of the ratio of the electrostatic force to gravity. The last formula may also be used when Λ≥1 with the interpretation that there is no collision if t is infinity or imaginary. We also discuss this motion along the straight line as a special case of the general elliptic motion of two bodies. I believe that this paper will be useful to university tutors as well as undergraduate and even graduate students who prefer to consider the special case before the general case, and their relationship
MIDPOINT TWO- STEPS RULE FOR THE SQUARE ROOT METHOD
African Journals Online (AJOL)
DR S.E UWAMUSI
Aberth third order method for finding zeros of a polynomial in interval ... KEY WORDS: Square root iteration, midpoint two steps Method, ...... A New set of Methods for the simultaneous determination of zeros of polynomial equation and iterative ...
Chi-square test and its application in hypothesis testing
Directory of Open Access Journals (Sweden)
Rakesh Rana
2015-01-01
Full Text Available In medical research, there are studies which often collect data on categorical variables that can be summarized as a series of counts. These counts are commonly arranged in a tabular format known as a contingency table. The chi-square test statistic can be used to evaluate whether there is an association between the rows and columns in a contingency table. More specifically, this statistic can be used to determine whether there is any difference between the study groups in the proportions of the risk factor of interest. Chi-square test and the logic of hypothesis testing were developed by Karl Pearson. This article describes in detail what is a chi-square test, on which type of data it is used, the assumptions associated with its application, how to manually calculate it and how to make use of an online calculator for calculating the Chi-square statistics and its associated P-value.
Bounded Perturbation Regularization for Linear Least Squares Estimation
Ballal, Tarig; Suliman, Mohamed Abdalla Elhag; Al-Naffouri, Tareq Y.
2017-01-01
This paper addresses the problem of selecting the regularization parameter for linear least-squares estimation. We propose a new technique called bounded perturbation regularization (BPR). In the proposed BPR method, a perturbation with a bounded
Multi-source least-squares migration of marine data
Wang, Xin; Schuster, Gerard T.
2012-01-01
Kirchhoff based multi-source least-squares migration (MSLSM) is applied to marine streamer data. To suppress the crosstalk noise from the excitation of multiple sources, a dynamic encoding function (including both time-shifts and polarity changes
Squaring the Circle: Attempting Peace in Northern Ireland
National Research Council Canada - National Science Library
Marchi, Gina
1997-01-01
Finding a political framework for self-government in Northern Ireland that will be supported by both nationalists and unionists is referred to as a modern day attempt to do the impossible-to 'square the circle...
Latin Square Thue-Morse Sequences are Overlap-Free
Directory of Open Access Journals (Sweden)
Christopher Robinson Tompkins
2007-01-01
Full Text Available We define a morphism based upon a Latin square that generalizes the Thue-Morse morphism. We prove that fixed points of this morphism are overlap-free sequences, generalizing results of Allouche - Shallit and Frid.
Suppression of vortex shedding around a square cylinder using ...
Indian Academy of Sciences (India)
control of vortex shedding of square cylinders using blowing or suction. ... also showed complete suppression of vortex shedding if suction velocity falls between 0.40 .... equations such that mass balance (continuity) is satisfied simultaneously.
Regularized plane-wave least-squares Kirchhoff migration
Wang, Xin; Dai, Wei; Schuster, Gerard T.
2013-01-01
A Kirchhoff least-squares migration (LSM) is developed in the prestack plane-wave domain to increase the quality of migration images. A regularization term is included that accounts for mispositioning of reflectors due to errors in the velocity
Improved linear least squares estimation using bounded data uncertainty
Ballal, Tarig
2015-04-01
This paper addresses the problemof linear least squares (LS) estimation of a vector x from linearly related observations. In spite of being unbiased, the original LS estimator suffers from high mean squared error, especially at low signal-to-noise ratios. The mean squared error (MSE) of the LS estimator can be improved by introducing some form of regularization based on certain constraints. We propose an improved LS (ILS) estimator that approximately minimizes the MSE, without imposing any constraints. To achieve this, we allow for perturbation in the measurement matrix. Then we utilize a bounded data uncertainty (BDU) framework to derive a simple iterative procedure to estimate the regularization parameter. Numerical results demonstrate that the proposed BDU-ILS estimator is superior to the original LS estimator, and it converges to the best linear estimator, the linear-minimum-mean-squared error estimator (LMMSE), when the elements of x are statistically white.
Plane-wave Least-squares Reverse Time Migration
Dai, Wei; Schuster, Gerard T.
2012-01-01
convergence for least-squares migration even when the migration velocity is not completely accurate. To significantly reduce computation cost, linear phase shift encoding is applied to hundreds of shot gathers to produce dozens of planes waves. A
3D plane-wave least-squares Kirchhoff migration
Wang, Xin; Dai, Wei; Huang, Yunsong; Schuster, Gerard T.
2014-01-01
A three dimensional least-squares Kirchhoff migration (LSM) is developed in the prestack plane-wave domain to increase the quality of migration images and the computational efficiency. Due to the limitation of current 3D marine acquisition
Making the most out of least-squares migration
Huang, Yunsong; Dutta, Gaurav; Dai, Wei; Wang, Xin; Schuster, Gerard T.; Yu, Jianhua
2014-01-01
) weak amplitudes resulting from geometric spreading, attenuation, and defocusing. These problems can be remedied in part by least-squares migration (LSM), also known as linearized seismic inversion or migration deconvolution (MD), which aims to linearly
Making the most out of the least (squares migration)
Dutta, Gaurav; Huang, Yunsong; Dai, Wei; Wang, Xin; Schuster, Gerard T.
2014-01-01
) ringiness caused by a ringy source wavelet. To partly remedy these problems, least-squares migration (LSM), also known as linearized seismic inversion or migration deconvolution (MD), proposes to linearly invert seismic data for the reflectivity distribution
Least squares analysis of fission neutron standard fields
International Nuclear Information System (INIS)
Griffin, P.J.; Williams, J.G.
1997-01-01
A least squares analysis of fission neutron standard fields has been performed using the latest dosimetry cross sections. Discrepant nuclear data are identified and adjusted spectra for 252 Cf spontaneous fission and 235 U thermal fission fields are presented
On square-free edge colorings of graphs
DEFF Research Database (Denmark)
Barat, Janos; Varju, P.P.
2008-01-01
An edge coloring of a graph is called square-free, if the sequence of colors on certain walks is not a square, that is not of the form x(1,)...,x(m), x(1),...,x(m), for any m epsilon N. Recently, various classes of walks have been suggested to be considered in the above definition. We construct...... graphs, for which the minimum number of colors needed for a square-free coloring is different if the considered set of walks vary, solving a problem posed by Bre ar and Klav2ar. We also prove the following: if an edge coloring of G is not square-free (even in the most general sense), then the length...
Improved linear least squares estimation using bounded data uncertainty
Ballal, Tarig; Al-Naffouri, Tareq Y.
2015-01-01
This paper addresses the problemof linear least squares (LS) estimation of a vector x from linearly related observations. In spite of being unbiased, the original LS estimator suffers from high mean squared error, especially at low signal-to-noise ratios. The mean squared error (MSE) of the LS estimator can be improved by introducing some form of regularization based on certain constraints. We propose an improved LS (ILS) estimator that approximately minimizes the MSE, without imposing any constraints. To achieve this, we allow for perturbation in the measurement matrix. Then we utilize a bounded data uncertainty (BDU) framework to derive a simple iterative procedure to estimate the regularization parameter. Numerical results demonstrate that the proposed BDU-ILS estimator is superior to the original LS estimator, and it converges to the best linear estimator, the linear-minimum-mean-squared error estimator (LMMSE), when the elements of x are statistically white.
Perception of Length to Width Relations of City Squares
Directory of Open Access Journals (Sweden)
Harold T. Nefs
2013-04-01
Full Text Available In this paper, we focus on how people perceive the aspect ratio of city squares. Earlier research has focused on distance perception but not so much on the perceived aspect ratio of the surrounding space. Furthermore, those studies have focused on “open” spaces rather than urban areas enclosed by walls, houses and filled with people, cars, etc. In two experiments, we therefore measured, using a direct and an indirect method, the perceived aspect ratio of five city squares in the historic city center of Delft, the Netherlands. We also evaluated whether the perceived aspect ratio of city squares was affected by the position of the observer on the square. In the first experiment, participants were asked to set the aspect ratio of a small rectangle such that it matched the perceived aspect ratio of the city square. In the second experiment, participants were asked to estimate the length and width of the city square separately. In the first experiment, we found that the perceived aspect ratio was in general lower than the physical aspect ratio. However, in the second experiment, we found that the calculated ratios were close to veridical except for the most elongated city square. We conclude therefore that the outcome depends on how the measurements are performed. Furthermore, although indirect measurements are nearly veridical, the perceived aspect ratio is an underestimation of the physical aspect ratio when measured in a direct way. Moreover, the perceived aspect ratio also depends on the location of the observer. These results may be beneficial to the design of large open urban environments, and in particular to rectangular city squares.
Consistency of the least weighted squares under heteroscedasticity
Czech Academy of Sciences Publication Activity Database
Víšek, Jan Ámos
2011-01-01
Roč. 2011, č. 47 (2011), s. 179-206 ISSN 0023-5954 Grant - others:GA UK(CZ) GA402/09/055 Institutional research plan: CEZ:AV0Z10750506 Keywords : Regression * Consistency * The least weighted squares * Heteroscedasticity Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.454, year: 2011 http://library.utia.cas.cz/separaty/2011/SI/visek-consistency of the least weighted squares under heteroscedasticity.pdf
Behaviour of FRP confined concrete in square columns
Diego Villalón, Ana de; Arteaga Iriarte, Ángel; Fernandez Gomez, Jaime Antonio; Perera Velamazán, Ricardo; Cisneros, Daniel
2015-01-01
A significant amount of research has been conducted on FRP-confined circular columns, but much less is known about rectangular/square columns in which the effectiveness of confinement is much reduced. This paper presents the results of experimental investigations on low strength square concrete columns confined with FRP. Axial compression tests were performed on ten intermediate size columns. The tests results indicate that FRP composites can significantly improve the bearing capacity and duc...
A Simple Square Rooting Circuit Based on Operational Amplifiers (OPAMPs
Directory of Open Access Journals (Sweden)
K. C. Selvam
2013-02-01
Full Text Available A simple circuit which accepts a negative voltage as input and provides an output voltage equal to the square root of the input voltage is described in this paper. The square rooting operation is dependent only on the ratio of two resistors and a DC voltage. Hence, the required accuracy can be obtained by employing precision resistors and a stable reference voltage. The feasibility of the circuit is examined by testing the results on a proto type.
Analisa Faktor Pembentuk Kualitas Layanan Di Starbucks the Square Surabaya
Tanujaya, Jimmy
2013-01-01
— Starbucks merupakan salah satu Perusahaan yang bergerak dibidang kedai kopi. Disini peneliti ingin meneliti faktor-faktor apa saja yang membentuk kualitas layanan di Starbucks The Square.Penelitian ini dilakukan untuk mengetahui dan menganalisis faktor apa saja yang membentuk kualitas layanan di Starbucks. Penelitian ini menggunakan jenis penelitian kuantitatif yang bertujuan untuk menganalisis faktor-faktor yang membentuk kualitas layanan di Starbucks The Square dengan menggunakan kuesion...
A Generalized Autocovariance Least-Squares Method for Covariance Estimation
DEFF Research Database (Denmark)
Åkesson, Bernt Magnus; Jørgensen, John Bagterp; Poulsen, Niels Kjølstad
2007-01-01
A generalization of the autocovariance least- squares method for estimating noise covariances is presented. The method can estimate mutually correlated system and sensor noise and can be used with both the predicting and the filtering form of the Kalman filter.......A generalization of the autocovariance least- squares method for estimating noise covariances is presented. The method can estimate mutually correlated system and sensor noise and can be used with both the predicting and the filtering form of the Kalman filter....
Mean Square Synchronization of Stochastic Nonlinear Delayed Coupled Complex Networks
Directory of Open Access Journals (Sweden)
Chengrong Xie
2013-01-01
Full Text Available We investigate the problem of adaptive mean square synchronization for nonlinear delayed coupled complex networks with stochastic perturbation. Based on the LaSalle invariance principle and the properties of the Weiner process, the controller and adaptive laws are designed to ensure achieving stochastic synchronization and topology identification of complex networks. Sufficient conditions are given to ensure the complex networks to be mean square synchronization. Furthermore, numerical simulations are also given to demonstrate the effectiveness of the proposed scheme.
Geoenvironmental profile of squares: north area of the city of Londrina-PR
Directory of Open Access Journals (Sweden)
Guilherme Silveira
2001-01-01
Full Text Available This article presents the concern to the quality and amount of the squares of the north area of the city of Londrina, state of Paraná. The square is a leisure, walk and rest place, besides favoring a closer contact of the population with the nature. The physical aspects of the furniture, presence and type of area of infantile and sporting recreation were analyzed, and also the identification and quantification of the species of trees. The results demonstrated absence of area of infantile recreation, 53% of the squares without furniture and sporting areas in 38% of the places. The amount of trees belonged to 340 individuals, divided in 35 species, with prevalence of 5 species that represents 64% of the total. Such results suggest the improvement of the amount and quality of the furniture, and a better distribution of the species of trees, giving preference for native species. The creation of a GIS, indicating the place of occurrence of the squares and its situation, is important because it facilitates the analysis of the green areas, as well as in the decisions for the urban development.
Direct numerical simulation of free and forced square jets
International Nuclear Information System (INIS)
Gohil, Trushar B.; Saha, Arun K.; Muralidhar, K.
2015-01-01
Highlights: • Free square jet at Re = 500–2000 is studied using DNS. • Forced square jet at Re = 1000 subjected to varicose perturbation is also investigated at various forcing frequencies. • Vortex interactions within the jet and jet spreading are affected both for free and forced jets. • Perturbation at higher frequency shows axis-switching. - Abstract: Direct numerical simulation (DNS) of incompressible, spatially developing square jets in the Reynolds number range of 500–2000 is reported. The three-dimensional unsteady Navier–Stokes equations are solved using high order spatial and temporal discretization. The objective of the present work is to understand the evolution of free and forced square jets by examining the formation of large-scale structures. Coherent structures and related interactions of free jets suggest control strategies that can be used to achieve enhanced spreading and mixing of the jet with the surrounding fluid. The critical Reynolds number for the onset on unsteadiness in an unperturbed free square jet is found to be 875–900 while it reduces to the range 500–525 in the presence of small-scale perturbations. Disturbances applied at the flow inlet cause saturation of KH-instability and early transition to turbulence. Forced jet calculations have been carried out using varicose perturbation with amplitude of 15%, while frequency is independently varied. Simulations show that the initial development of the square jet is influenced by the four corners leading to the appearance hairpin structures along with the formation of vortex rings. Farther downstream, adjacent vortices strongly interact leading to their rapid breakup. Excitation frequencies in the range 0.4–0.6 cause axis-switching of the jet cross-section. Results show that square jets achieve greater spreading but are less controllable in comparison to the circular ones
Total parenteral nutrition - infants
... medlineplus.gov/ency/article/007239.htm Total parenteral nutrition - infants To use the sharing features on this page, please enable JavaScript. Total parenteral nutrition (TPN) is a method of feeding that bypasses ...
... medlineplus.gov/ency/patientinstructions/000177.htm Total parenteral nutrition To use the sharing features on this page, please enable JavaScript. Total parenteral nutrition (TPN) is a method of feeding that bypasses ...
Technique of total thyroidectomy
International Nuclear Information System (INIS)
Rao, R.S.
1999-01-01
It is essential to define the various surgical procedures that are carried out for carcinoma of the thyroid gland. They are thyroid gland, subtotal lobectomy, total thyroidectomy and near total thyroidectomy
... page: //medlineplus.gov/ency/article/003489.htm Total iron binding capacity To use the sharing features on this page, please enable JavaScript. Total iron binding capacity (TIBC) is a blood test to ...
Chkifa, Abdellah
2015-04-08
Motivated by the numerical treatment of parametric and stochastic PDEs, we analyze the least-squares method for polynomial approximation of multivariate functions based on random sampling according to a given probability measure. Recent work has shown that in the univariate case, the least-squares method is quasi-optimal in expectation in [A. Cohen, M A. Davenport and D. Leviatan. Found. Comput. Math. 13 (2013) 819–834] and in probability in [G. Migliorati, F. Nobile, E. von Schwerin, R. Tempone, Found. Comput. Math. 14 (2014) 419–456], under suitable conditions that relate the number of samples with respect to the dimension of the polynomial space. Here “quasi-optimal” means that the accuracy of the least-squares approximation is comparable with that of the best approximation in the given polynomial space. In this paper, we discuss the quasi-optimality of the polynomial least-squares method in arbitrary dimension. Our analysis applies to any arbitrary multivariate polynomial space (including tensor product, total degree or hyperbolic crosses), under the minimal requirement that its associated index set is downward closed. The optimality criterion only involves the relation between the number of samples and the dimension of the polynomial space, independently of the anisotropic shape and of the number of variables. We extend our results to the approximation of Hilbert space-valued functions in order to apply them to the approximation of parametric and stochastic elliptic PDEs. As a particular case, we discuss “inclusion type” elliptic PDE models, and derive an exponential convergence estimate for the least-squares method. Numerical results confirm our estimate, yet pointing out a gap between the condition necessary to achieve optimality in the theory, and the condition that in practice yields the optimal convergence rate.
On squares of representations of compact Lie algebras
Energy Technology Data Exchange (ETDEWEB)
Zeier, Robert, E-mail: robert.zeier@ch.tum.de [Department Chemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching (Germany); Zimborás, Zoltán, E-mail: zimboras@gmail.com [Department of Computer Science, University College London, Gower St., London WC1E 6BT (United Kingdom)
2015-08-15
We study how tensor products of representations decompose when restricted from a compact Lie algebra to one of its subalgebras. In particular, we are interested in tensor squares which are tensor products of a representation with itself. We show in a classification-free manner that the sum of multiplicities and the sum of squares of multiplicities in the corresponding decomposition of a tensor square into irreducible representations has to strictly grow when restricted from a compact semisimple Lie algebra to a proper subalgebra. For this purpose, relevant details on tensor products of representations are compiled from the literature. Since the sum of squares of multiplicities is equal to the dimension of the commutant of the tensor-square representation, it can be determined by linear-algebra computations in a scenario where an a priori unknown Lie algebra is given by a set of generators which might not be a linear basis. Hence, our results offer a test to decide if a subalgebra of a compact semisimple Lie algebra is a proper one without calculating the relevant Lie closures, which can be naturally applied in the field of controlled quantum systems.
On squares of representations of compact Lie algebras
International Nuclear Information System (INIS)
Zeier, Robert; Zimborás, Zoltán
2015-01-01
We study how tensor products of representations decompose when restricted from a compact Lie algebra to one of its subalgebras. In particular, we are interested in tensor squares which are tensor products of a representation with itself. We show in a classification-free manner that the sum of multiplicities and the sum of squares of multiplicities in the corresponding decomposition of a tensor square into irreducible representations has to strictly grow when restricted from a compact semisimple Lie algebra to a proper subalgebra. For this purpose, relevant details on tensor products of representations are compiled from the literature. Since the sum of squares of multiplicities is equal to the dimension of the commutant of the tensor-square representation, it can be determined by linear-algebra computations in a scenario where an a priori unknown Lie algebra is given by a set of generators which might not be a linear basis. Hence, our results offer a test to decide if a subalgebra of a compact semisimple Lie algebra is a proper one without calculating the relevant Lie closures, which can be naturally applied in the field of controlled quantum systems
Sound field simulation and acoustic animation in urban squares
Kang, Jian; Meng, Yan
2005-04-01
Urban squares are important components of cities, and the acoustic environment is important for their usability. While models and formulae for predicting the sound field in urban squares are important for their soundscape design and improvement, acoustic animation tools would be of great importance for designers as well as for public participation process, given that below a certain sound level, the soundscape evaluation depends mainly on the type of sounds rather than the loudness. This paper first briefly introduces acoustic simulation models developed for urban squares, as well as empirical formulae derived from a series of simulation. It then presents an acoustic animation tool currently being developed. In urban squares there are multiple dynamic sound sources, so that the computation time becomes a main concern. Nevertheless, the requirements for acoustic animation in urban squares are relatively low compared to auditoria. As a result, it is important to simplify the simulation process and algorithms. Based on a series of subjective tests in a virtual reality environment with various simulation parameters, a fast simulation method with acceptable accuracy has been explored. [Work supported by the European Commission.
DEFF Research Database (Denmark)
Finbow, Arthur; Frendrup, Allan; Vestergaard, Preben D.
cardinality then G is a total well dominated graph. In this paper we study composition and decomposition of total well dominated trees. By a reversible process we prove that any total well dominated tree can both be reduced to and constructed from a family of three small trees....
From least squares to multilevel modeling: A graphical introduction to Bayesian inference
Loredo, Thomas J.
2016-01-01
This tutorial presentation will introduce some of the key ideas and techniques involved in applying Bayesian methods to problems in astrostatistics. The focus will be on the big picture: understanding the foundations (interpreting probability, Bayes's theorem, the law of total probability and marginalization), making connections to traditional methods (propagation of errors, least squares, chi-squared, maximum likelihood, Monte Carlo simulation), and highlighting problems where a Bayesian approach can be particularly powerful (Poisson processes, density estimation and curve fitting with measurement error). The "graphical" component of the title reflects an emphasis on pictorial representations of some of the math, but also on the use of graphical models (multilevel or hierarchical models) for analyzing complex data. Code for some examples from the talk will be available to participants, in Python and in the Stan probabilistic programming language.
Least squares reverse time migration of controlled order multiples
Liu, Y.
2016-12-01
Imaging using the reverse time migration of multiples generates inherent crosstalk artifacts due to the interference among different order multiples. Traditionally, least-square fitting has been used to address this issue by seeking the best objective function to measure the amplitude differences between the predicted and observed data. We have developed an alternative objective function by decomposing multiples into different orders to minimize the difference between Born modeling predicted multiples and specific-order multiples from observational data in order to attenuate the crosstalk. This method is denoted as the least-squares reverse time migration of controlled order multiples (LSRTM-CM). Our numerical examples demonstrated that the LSRTM-CM can significantly improve image quality compared with reverse time migration of multiples and least-square reverse time migration of multiples. Acknowledgments This research was funded by the National Nature Science Foundation of China (Grant Nos. 41430321 and 41374138).
A note on Dupuy's QJM and new square law
Directory of Open Access Journals (Sweden)
G. Geldenhuys
2003-12-01
Full Text Available T N Duputy has developed various operations research models in an attempt to quantify lessons that can be learned from military history. We discuss two of his models, the Quantified Judgment Model (QJM, and the "new square law". The QJM was developed by Duputy for the analysis of military operations. We point out mathematical discrepancies in a part of the model and make suggestions to remove these discrepancies. Duputy's new square law is an attempt to modify the well-known Lanchester equations for aimed fire, taking into account some results that were obtained in the QJM. We show that the new square law cannot be accepted as a valid mathematical model of combat attrition.
Closure of the squared Zakharov--Shabat eigenstates
International Nuclear Information System (INIS)
Kaup, D.J.
1976-01-01
By solution of the inverse scattering problem for a third-order (degenerate) eigenvalue problem, the closure of the squared eigenfunctions of the Zakharov--Shabat equations is found. The question of the completeness of squared eigenstates occurs in many aspects of ''inverse scattering transforms'' (solving nonlinear evolution equations exactly by inverse scattering techniques), as well as in various aspects of the inverse scattering problem. The method used here is quite suggestive as to how one might find the closure of the squared eigenfunctions of other eigenvalue equations, and the strong analogy between these results and the problem of finding the closure of the eigenvectors of a nonself-adjoint matrix is pointed out
High-frequency matrix converter with square wave input
Carr, Joseph Alexander; Balda, Juan Carlos
2015-03-31
A device for producing an alternating current output voltage from a high-frequency, square-wave input voltage comprising, high-frequency, square-wave input a matrix converter and a control system. The matrix converter comprises a plurality of electrical switches. The high-frequency input and the matrix converter are electrically connected to each other. The control system is connected to each switch of the matrix converter. The control system is electrically connected to the input of the matrix converter. The control system is configured to operate each electrical switch of the matrix converter converting a high-frequency, square-wave input voltage across the first input port of the matrix converter and the second input port of the matrix converter to an alternating current output voltage at the output of the matrix converter.
Square vortex lattice in p-wave superconductors
International Nuclear Information System (INIS)
Shiraishi, J.
1999-01-01
Making use of the Ginzburg Landau equation for isotropic p-wave superconductors, we construct the single vortex solution in part analytically. The fourfold symmetry breaking term arising from the tetragonal symmetry distortion of the Fermi surface is crucial, since this term indicates a fourfold distortion of the vortex core somewhat similar to the one found in d-wave superconductors. This fourfold distortion of the vortex core in turn favors the square vortex lattice as observed recently by small angle neutron scattering (SANS) experiment from Sr 2 RuO 4 . We find that the hexagonal vortex lattice at H = H c1 transforms into the square one for H = H cr = 0.26 H c2 . On the other hand the SANS data does not reveal such transition. The square vortex covers everywhere studied by the SANS implying H cr is very close to H c1 . Therefore some improvement in the present model is certainly desirable. (orig.)
Least-squares methods for identifying biochemical regulatory networks from noisy measurements
Directory of Open Access Journals (Sweden)
Heslop-Harrison Pat
2007-01-01
Full Text Available Abstract Background We consider the problem of identifying the dynamic interactions in biochemical networks from noisy experimental data. Typically, approaches for solving this problem make use of an estimation algorithm such as the well-known linear Least-Squares (LS estimation technique. We demonstrate that when time-series measurements are corrupted by white noise and/or drift noise, more accurate and reliable identification of network interactions can be achieved by employing an estimation algorithm known as Constrained Total Least Squares (CTLS. The Total Least Squares (TLS technique is a generalised least squares method to solve an overdetermined set of equations whose coefficients are noisy. The CTLS is a natural extension of TLS to the case where the noise components of the coefficients are correlated, as is usually the case with time-series measurements of concentrations and expression profiles in gene networks. Results The superior performance of the CTLS method in identifying network interactions is demonstrated on three examples: a genetic network containing four genes, a network describing p53 activity and mdm2 messenger RNA interactions, and a recently proposed kinetic model for interleukin (IL-6 and (IL-12b messenger RNA expression as a function of ATF3 and NF-κB promoter binding. For the first example, the CTLS significantly reduces the errors in the estimation of the Jacobian for the gene network. For the second, the CTLS reduces the errors from the measurements that are corrupted by white noise and the effect of neglected kinetics. For the third, it allows the correct identification, from noisy data, of the negative regulation of (IL-6 and (IL-12b by ATF3. Conclusion The significant improvements in performance demonstrated by the CTLS method under the wide range of conditions tested here, including different levels and types of measurement noise and different numbers of data points, suggests that its application will enable
The mean squared writhe of alternating random knot diagrams
Energy Technology Data Exchange (ETDEWEB)
Diao, Y; Hinson, K [Department of Mathematics and Statistics University of North Carolina at Charlotte, NC 28223 (United States); Ernst, C; Ziegler, U, E-mail: ydiao@uncc.ed [Department of Mathematics and Computer Science, Western Kentucky University, Bowling Green, KY 42101 (United States)
2010-12-10
The writhe of a knot diagram is a simple geometric measure of the complexity of the knot diagram. It plays an important role not only in knot theory itself, but also in various applications of knot theory to fields such as molecular biology and polymer physics. The mean squared writhe of any sample of knot diagrams with n crossings is n when for each diagram at each crossing one of the two strands is chosen as the overpass at random with probability one-half. However, such a diagram is usually not minimal. If we restrict ourselves to a minimal knot diagram, then the choice of which strand is the over- or under-strand at each crossing is no longer independent of the neighboring crossings and a larger mean squared writhe is expected for minimal diagrams. This paper explores the effect on the correlation between the mean squared writhe and the diagrams imposed by the condition that diagrams are minimal by studying the writhe of classes of reduced, alternating knot diagrams. We demonstrate that the behavior of the mean squared writhe heavily depends on the underlying space of diagram templates. In particular this is true when the sample space contains only diagrams of a special structure. When the sample space is large enough to contain not only diagrams of a special type, then the mean squared writhe for n crossing diagrams tends to grow linearly with n, but at a faster rate than n, indicating an intrinsic property of alternating knot diagrams. Studying the mean squared writhe of alternating random knot diagrams also provides some insight into the properties of the diagram generating methods used, which is an important area of study in the applications of random knot theory.
The generalization of the exterior square of a Bieberbach group
Masri, Rohaidah; Hassim, Hazzirah Izzati Mat; Sarmin, Nor Haniza; Ali, Nor Muhainiah Mohd; Idrus, Nor'ashiqin Mohd
2014-06-01
The exterior square of a group is one of the homological functors which were originated in the homotopy theory. Meanwhile, a Bieberbach group is a torsion free crystallographic group. A Bieberbach group with cyclic point group of order two, C2, of dimension n can be defined as the direct product of that group of the smallest dimension with a free abelian group. Using the group presentation and commutator generating sequence, the exterior square of a Bieberbach group with point group C2 of dimension n is computed.
Chi-squared goodness of fit tests with applications
Balakrishnan, N; Nikulin, MS
2013-01-01
Chi-Squared Goodness of Fit Tests with Applications provides a thorough and complete context for the theoretical basis and implementation of Pearson's monumental contribution and its wide applicability for chi-squared goodness of fit tests. The book is ideal for researchers and scientists conducting statistical analysis in processing of experimental data as well as to students and practitioners with a good mathematical background who use statistical methods. The historical context, especially Chapter 7, provides great insight into importance of this subject with an authoritative author team
Radiation Field of a Square, Helical Beam Antenna
DEFF Research Database (Denmark)
Knudsen, Hans Lottrup
1952-01-01
square helices are used. Further, in connection with corresponding rigorous formulas for the field from a circular, helical antenna with a uniformly progressing current wave of constant amplitude the present formulas may be used for an investigation of the magnitude of the error introduced in Kraus......' approximate calculation of the field from a circular, helical antenna by replacing this antenna with an ``equivalent'' square helix. This investigation is carried out by means of a numerical example. The investigation shows that Kraus' approximate method of calculation yields results in fair agreement...
Square Van Atta reflector with conducting mounting flame
DEFF Research Database (Denmark)
Nielsen, Erik Dragø
1970-01-01
A theoretical and numerical analysis of square Van Atta reflectors has been carried out with or without a conducting plate, used for mounting of the antenna elements. The Van Atta reflector investigated has antenna elements which are parallel half-wave dipoles interconnected in pairs by transmiss......A theoretical and numerical analysis of square Van Atta reflectors has been carried out with or without a conducting plate, used for mounting of the antenna elements. The Van Atta reflector investigated has antenna elements which are parallel half-wave dipoles interconnected in pairs...
Multi-source least-squares migration of marine data
Wang, Xin
2012-11-04
Kirchhoff based multi-source least-squares migration (MSLSM) is applied to marine streamer data. To suppress the crosstalk noise from the excitation of multiple sources, a dynamic encoding function (including both time-shifts and polarity changes) is applied to the receiver side traces. Results show that the MSLSM images are of better quality than the standard Kirchhoff migration and reverse time migration images; moreover, the migration artifacts are reduced and image resolution is significantly improved. The computational cost of MSLSM is about the same as conventional least-squares migration, but its IO cost is significantly decreased.
Radiation and viscous dissipation effect on square porous annulus
Energy Technology Data Exchange (ETDEWEB)
Badruddin, Irfan Anjum [Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 (Malaysia); Quadir, G. A. [School of Mechatronic Engineering, University Malaysia Perlis, Pauh Putra, 02600 Arau, Perlis (Malaysia)
2016-06-08
The present study is carried out to investigate the effect of radiation and viscous dissipation in a square porous annulus subjected to outside hot T{sub h} and inside cold T{sub c} temperature. The square annulus has a hollow section of dimension D×D at the interior of annulus. The flow is assumed to obey Darcy law. The governing equations are non-dimensionalised and solved with the help of finite element method. Results are discussed with respect to viscous dissipation parameter, radiation parameter and size of the hollow section of annulus.
Sparse least-squares reverse time migration using seislets
Dutta, Gaurav
2015-08-19
We propose sparse least-squares reverse time migration (LSRTM) using seislets as a basis for the reflectivity distribution. This basis is used along with a dip-constrained preconditioner that emphasizes image updates only along prominent dips during the iterations. These dips can be estimated from the standard migration image or from the gradient using plane-wave destruction filters or structural tensors. Numerical tests on synthetic datasets demonstrate the benefits of this method for mitigation of aliasing artifacts and crosstalk noise in multisource least-squares migration.
Proportionate-type normalized last mean square algorithms
Wagner, Kevin
2013-01-01
The topic of this book is proportionate-type normalized least mean squares (PtNLMS) adaptive filtering algorithms, which attempt to estimate an unknown impulse response by adaptively giving gains proportionate to an estimate of the impulse response and the current measured error. These algorithms offer low computational complexity and fast convergence times for sparse impulse responses in network and acoustic echo cancellation applications. New PtNLMS algorithms are developed by choosing gains that optimize user-defined criteria, such as mean square error, at all times. PtNLMS algorithms ar
Global Search Strategies for Solving Multilinear Least-Squares Problems
Directory of Open Access Journals (Sweden)
Mats Andersson
2012-04-01
Full Text Available The multilinear least-squares (MLLS problem is an extension of the linear least-squares problem. The difference is that a multilinear operator is used in place of a matrix-vector product. The MLLS is typically a large-scale problem characterized by a large number of local minimizers. It originates, for instance, from the design of filter networks. We present a global search strategy that allows for moving from one local minimizer to a better one. The efficiency of this strategy is illustrated by the results of numerical experiments performed for some problems related to the design of filter networks.
LSL: a logarithmic least-squares adjustment method
International Nuclear Information System (INIS)
Stallmann, F.W.
1982-01-01
To meet regulatory requirements, spectral unfolding codes must not only provide reliable estimates for spectral parameters, but must also be able to determine the uncertainties associated with these parameters. The newer codes, which are more appropriately called adjustment codes, use the least squares principle to determine estimates and uncertainties. The principle is simple and straightforward, but there are several different mathematical models to describe the unfolding problem. In addition to a sound mathematical model, ease of use and range of options are important considerations in the construction of adjustment codes. Based on these considerations, a least squares adjustment code for neutron spectrum unfolding has been constructed some time ago and tentatively named LSL
Partial strengthening of R.C square columns using CFRP
Directory of Open Access Journals (Sweden)
Ahmed Shaban Abdel-Hay
2014-12-01
An experimental program was undertaken testing ten square columns 200 × 200 × 2000 mm. One of them was a control specimen and the other nine specimens were strengthened with CFRP. The main parameters studied in this research were the compressive strength of the upper part, the height of the upper poor concrete part, and the height of CFRP wrapped part of column. The experimental results including mode of failure, ultimate load, concrete strain, and fiber strains were analyzed. The main conclusion of this research was, partial strengthening of square column using CFRP can be permitted and gives good results of the column carrying capacity.
On a Generalized Squared Gaussian Diffusion Model for Option Valuation
Directory of Open Access Journals (Sweden)
Edeki S.O.
2017-01-01
Full Text Available In financial mathematics, option pricing models are vital tools whose usefulness cannot be overemphasized. Modern approaches and modelling of financial derivatives are therefore required in option pricing and valuation settings. In this paper, we derive via the application of Ito lemma, a pricing model referred to as Generalized Squared Gaussian Diffusion Model (GSGDM for option pricing and valuation. Same approach can be considered via Stratonovich stochastic dynamics. We also show that the classical Black-Scholes, and the square root constant elasticity of variance models are special cases of the GSGDM. In addition, general solution of the GSGDM is obtained using modified variational iterative method (MVIM.
A decentralized square root information filter/smoother
Bierman, G. J.; Belzer, M. R.
1985-01-01
A number of developments has recently led to a considerable interest in the decentralization of linear least squares estimators. The developments are partly related to the impending emergence of VLSI technology, the realization of parallel processing, and the need for algorithmic ways to speed the solution of dynamically decoupled, high dimensional estimation problems. A new method is presented for combining Square Root Information Filters (SRIF) estimates obtained from independent data sets. The new method involves an orthogonal transformation, and an information matrix filter 'homework' problem discussed by Schweppe (1973) is generalized. The employed SRIF orthogonal transformation methodology has been described by Bierman (1977).
Radiation and viscous dissipation effect on square porous annulus
International Nuclear Information System (INIS)
Badruddin, Irfan Anjum; Quadir, G. A.
2016-01-01
The present study is carried out to investigate the effect of radiation and viscous dissipation in a square porous annulus subjected to outside hot T h and inside cold T c temperature. The square annulus has a hollow section of dimension D×D at the interior of annulus. The flow is assumed to obey Darcy law. The governing equations are non-dimensionalised and solved with the help of finite element method. Results are discussed with respect to viscous dissipation parameter, radiation parameter and size of the hollow section of annulus.
Directory of Open Access Journals (Sweden)
Ka Lok Chu
2011-02-01
Full Text Available We study singular magic matrices in which the numbers in the rows and columns and in the two main diagonals all add up to the same sum. Our interest focuses on such magic matrices for which the Moore–Penrose inverse is also magic. Special attention is given to the “Daniels–Zlobec magic square’’ introduced by the British magician and television performer Paul Daniels (b. 1938 and considered by Zlobec (2001; see also Murray (1989, pp. 30–32. We introduce the concept of a “philatelic magic square” as a square arrangement of images of postage stamps so that the associated nominal values form a magic square. Three philatelic magic squares with stamps especially chosen for Sanjo Zlobec are presented in celebration of his 70th birthday; most helpful in identifying these stamps was an Excel checklist by Männikkö (2009.
Moving least squares simulation of free surface flows
DEFF Research Database (Denmark)
Felter, C. L.; Walther, Jens Honore; Henriksen, Christian
2014-01-01
In this paper a Moving Least Squares method (MLS) for the simulation of 2D free surface flows is presented. The emphasis is on the governing equations, the boundary conditions, and the numerical implementation. The compressible viscous isothermal Navier–Stokes equations are taken as the starting ...
Performance Evaluation of the Ordinary Least Square (OLS) and ...
African Journals Online (AJOL)
Nana Kwasi Peprah
1Deparment of Geomatic Engineering, University of Mines and Technology, ... precise, accurate and can be used to execute any engineering works due to ..... and Ordinary Least Squares Methods”, Journal of Geomatics and Planning, Vol ... Technology”, Unpublished BSc Project Report, University of Mines and Technology ...
African Journal of Science and Technology (AJST) NON-SQUARE ...
African Journals Online (AJOL)
opiyo
ABSTRACT: This paper presents calculations demonstrating that non-square quantum well growth. (well shaping) can result in reduced threshold current for tensilely strained quantum well bipolar diode lasers operating at 1.52µm m. Calculations of subband structure, optical matrix elements and laser gain are performed for ...
The Massacre in Tiananmen Square: An Eye Witness Account.
Wolken, Lawrence C.
1989-01-01
Recounts personal observations of a former resident of the People's Republic of China during the events of the summer of 1989. Notes changes including a new sense of purpose and a spirit of openness, as well as improvement in the standard of living. Considers the impact of the tragic incident in Tiananmen Square on these improvements in Chinese…
Tiananmen Square and China--One Year Later.
Doyle, Deborah
1991-01-01
Reports an individual's observations during a trip to China. Argues that the U.S. government and students must learn to understand and appreciate China because of its large population, market potential, and position among major world powers. Discusses personal impressions, the protesters at Tiananmen Square and elsewhere, and reactions to…
Analysis of Nonlinear Dynamics by Square Matrix Method
Energy Technology Data Exchange (ETDEWEB)
Yu, Li Hua [Brookhaven National Lab. (BNL), Upton, NY (United States). Energy and Photon Sciences Directorate. National Synchrotron Light Source II
2016-07-25
The nonlinear dynamics of a system with periodic structure can be analyzed using a square matrix. In this paper, we show that because the special property of the square matrix constructed for nonlinear dynamics, we can reduce the dimension of the matrix from the original large number for high order calculation to low dimension in the first step of the analysis. Then a stable Jordan decomposition is obtained with much lower dimension. The transformation to Jordan form provides an excellent action-angle approximation to the solution of the nonlinear dynamics, in good agreement with trajectories and tune obtained from tracking. And more importantly, the deviation from constancy of the new action-angle variable provides a measure of the stability of the phase space trajectories and their tunes. Thus the square matrix provides a novel method to optimize the nonlinear dynamic system. The method is illustrated by many examples of comparison between theory and numerical simulation. Finally, in particular, we show that the square matrix method can be used for optimization to reduce the nonlinearity of a system.
Counting Your Way to the Sum of Squares Formula
Indian Academy of Sciences (India)
IAS Admin
This gives us a brand new formula for the sum of the squares of the first n positive integers! A small tweak gives us a second formula, for free! For, we have the following identity for the binomial coeffi- cients which comes from the well known recursive rela- tion which the binomial coefficients satisfy: (n + 1. 3 )+ ( n + 1. 2 )= (.
Latin-square three-dimensional gage master
Jones, L.
1981-05-12
A gage master for coordinate measuring machines has an nxn array of objects distributed in the Z coordinate utilizing the concept of a Latin square experimental design. Using analysis of variance techniques, the invention may be used to identify sources of error in machine geometry and quantify machine accuracy.
Non linear-least-squares fitting for pixe spectra
International Nuclear Information System (INIS)
Benamar, M.A.; Tchantchane, A.; Benouali, N.; Azbouche, A.; Tobbeche, S.
1992-10-01
An interactive computer program for the analysis of Pixe spectra is described. The fitting procedure consists of computing a function which approximates the experimental data. A nonlinear least-squares fitting is used to determine the parameters of the fit. The program takes into account the low energy tail and the escape peaks
Noninteracting Fermi gas in a square-well potential.
Nash, C. E.
1971-01-01
The problem of a noninteracting Fermi gas in a finite square-well potential is solved analytically in the limit that the well becomes infinitely wide. The errors of previous authors using this model as a first approximation to the problem of a simple metal with surfaces are pointed out.
Plane-wave Least-squares Reverse Time Migration
Dai, Wei
2012-11-04
Least-squares reverse time migration is formulated with a new parameterization, where the migration image of each shot is updated separately and a prestack image is produced with common image gathers. The advantage is that it can offer stable convergence for least-squares migration even when the migration velocity is not completely accurate. To significantly reduce computation cost, linear phase shift encoding is applied to hundreds of shot gathers to produce dozens of planes waves. A regularization term which penalizes the image difference between nearby angles are used to keep the prestack image consistent through all the angles. Numerical tests on a marine dataset is performed to illustrate the advantages of least-squares reverse time migration in the plane-wave domain. Through iterations of least-squares migration, the migration artifacts are reduced and the image resolution is improved. Empirical results suggest that the LSRTM in plane wave domain is an efficient method to improve the image quality and produce common image gathers.
Multivariate calibration with least-squares support vector machines.
Thissen, U.M.J.; Ustun, B.; Melssen, W.J.; Buydens, L.M.C.
2004-01-01
This paper proposes the use of least-squares support vector machines (LS-SVMs) as a relatively new nonlinear multivariate calibration method, capable of dealing with ill-posed problems. LS-SVMs are an extension of "traditional" SVMs that have been introduced recently in the field of chemistry and
Steel Housing - The Reinvention of the Square Wheel?
Willems, M.H.P.M.
2002-01-01
Steel housing has some remarkable resemblance with a square wheel. Both combine a simple concept, uncommon appearance and lack of appreciation. The title furthermore refers to the repeated stubborn efforts over the last decennia to develop prefabricated steel-based housing systems. Steel has
Table of nuclear root mean square charge radii. Summary
International Nuclear Information System (INIS)
Paviotti-Corcuera, R.; McLaughlin, P.K.
1999-01-01
This document describes a table of nuclear root-mean-square (rms) charge radii evaluated by two different procedures. The data are available from the IAEA Nuclear Data Section via INTERNET or on PC diskettes upon request. This document supersedes the previous IAEA-NDS-163, 1990, 'Nuclear Charge Radii'. (author)
El nuevo Madison Square Garden – (EE.UU.
Directory of Open Access Journals (Sweden)
Luckman, Ch.
1971-05-01
Full Text Available The Madison Square Garden Sports and Amusements Center comprises the following. 1. A circular building, 129.54 m in diameter and 45.72 m high, which houses the New Madison Square Garden and many other facilities. The arena sits 20.250 spectators, who can watch hockey, basketball, cycling, boxing, circus shows, ice skating, special displays, variety shows, meetings and other kinds of performance. 2. An office block on Seventh Avenue, with a useful floor area for office use amounting to 111,500 m2 and a further 4,800 m2 of floor area on the first two floors for commercial and banking activities.Forman parte del Centro Deportivo y de Atracciones Madison Square Garden: 1 Un edificio circular, de 129,54 m de diámetro y 45,72 m de altura, que aloja el Nuevo Madison Square Garden y otras muchas instalaciones. Tiene capacidad para 20.250 asientos, y en él se pueden celebrar espectáculos de: hockey, baloncesto, ciclismo, boxeo, circo, patinaje sobre hielo, acontecimientos especiales, variedades, asambleas y otros deportes de masas, etc. 2 Un edificio de oficinas que se alza contiguo a la Séptima Avenida, con una superficie útil de 111.500 m2 destinada a oficinas, y otra de 4.800 m2, en las plantas primera y segunda, dedicada a actividades comerciales y bancarias.
Thermal performance in circular tube fitted with coiled square wires
International Nuclear Information System (INIS)
Promvonge, Pongjet
2008-01-01
The effects of wires with square cross section forming a coil used as a turbulator on the heat transfer and turbulent flow friction characteristics in a uniform heat flux, circular tube are experimentally investigated in the present work. The experiments are performed for flows with Reynolds numbers ranging from 5000 to 25,000. Two different spring coiled wire pitches are introduced. The results are also compared with those obtained from using a typical coiled circular wire, apart from the smooth tube. The experimental results reveal that the use of coiled square wire turbulators leads to a considerable increase in heat transfer and friction loss over those of a smooth wall tube. The Nusselt number increases with the rise of Reynolds number and the reduction of pitch for both circular and square wire coils. The coiled square wire provides higher heat transfer than the circular one under the same conditions. Also, performance evaluation criteria to assess the real benefits in using both coil wires of the enhanced tube are determined
The square of opposition a cornerstone of thought
Basti, Gianfranco
2017-01-01
This is a collection of new investigations and discoveries on the theory of opposition (square, hexagon, octagon, polyhedra of opposition) by the best specialists from all over the world. The papers range from historical considerations to new mathematical developments of the theory of opposition including applications to theology, theory of argumentation and metalogic.
Mean square exponential stability of stochastic delayed Hopfield neural networks
International Nuclear Information System (INIS)
Wan Li; Sun Jianhua
2005-01-01
Stochastic effects to the stability property of Hopfield neural networks (HNN) with discrete and continuously distributed delay are considered. By using the method of variation parameter, inequality technique and stochastic analysis, the sufficient conditions to guarantee the mean square exponential stability of an equilibrium solution are given. Two examples are also given to demonstrate our results
Madhava, Gregory, Leibnitz, and Sums of Two Squares
Indian Academy of Sciences (India)
IAS Admin
Keywords. Gregory–Leibnitz series, lattice points, sums of two squares,. Gauss circle problem. Shailesh Shirali heads the. Community Math Centre in Rishi Valley School and works in the field of teacher education. He is the author of many books and articles in mathemat- ics, written for interested students in the age range.
Wave-equation Q tomography and least-squares migration
Dutta, Gaurav
2016-01-01
optimization method that inverts for the subsurface Q distribution by minimizing a skeletonized misfit function ε. Here, ε is the sum of the squared differences between the observed and the predicted peak/centroid-frequency shifts of the early-arrivals. Through
Preconditioned Iterative Methods for Solving Weighted Linear Least Squares Problems
Czech Academy of Sciences Publication Activity Database
Bru, R.; Marín, J.; Mas, J.; Tůma, Miroslav
2014-01-01
Roč. 36, č. 4 (2014), A2002-A2022 ISSN 1064-8275 Institutional support: RVO:67985807 Keywords : preconditioned iterative methods * incomplete decompositions * approximate inverses * linear least squares Subject RIV: BA - General Mathematics Impact factor: 1.854, year: 2014
Changing public space. The recent redevelopment of Dutch city squares
van Melik, R.G.
2008-01-01
Public spaces in Dutch city centres are increasingly subject to facelifts. The car parking that dominated city squares until the 1980s has been removed and replaced by modern street furniture, city stages, and an abundance of sidewalk caf鳮 At the same time, public spaces are more controlled by
Double asymptotics for the chi-square statistic.
Rempała, Grzegorz A; Wesołowski, Jacek
2016-12-01
Consider distributional limit of the Pearson chi-square statistic when the number of classes m n increases with the sample size n and [Formula: see text]. Under mild moment conditions, the limit is Gaussian for λ = ∞, Poisson for finite λ > 0, and degenerate for λ = 0.
Least-mean-square spatial filter for IR sensors.
Takken, E H; Friedman, D; Milton, A F; Nitzberg, R
1979-12-15
A new least-mean-square filter is defined for signal-detection problems. The technique is proposed for scanning IR surveillance systems operating in poorly characterized but primarily low-frequency clutter interference. Near-optimal detection of point-source targets is predicted both for continuous-time and sampled-data systems.
Some Results on Mean Square Error for Factor Score Prediction
Krijnen, Wim P.
2006-01-01
For the confirmatory factor model a series of inequalities is given with respect to the mean square error (MSE) of three main factor score predictors. The eigenvalues of these MSE matrices are a monotonic function of the eigenvalues of the matrix gamma[subscript rho] = theta[superscript 1/2] lambda[subscript rho] 'psi[subscript rho] [superscript…
Restoration and the City: The Role of Public Urban Squares
Directory of Open Access Journals (Sweden)
César San Juan
2017-12-01
Full Text Available Over recent decades, the study of psychological restoration has attracted a considerable amount of interest within and without the boundaries of environmental psychology, with most of the work focused on analyzing restoration in natural contexts. However, little attention has been paid to the (possible restorative potential of urban settings, as they have usually been expected not to be restorative and to present some elements that might imply negative health outcomes in the short and long term. In this field study, our aim was to evaluate restoration in urban squares. To this end, we measured participants' attentional and affective states both before and after spending half an hour in an urban square. A sample of 46 subjects contemplated and walked through one of the two selected squares that differed in restorative potential (PRS. Analyses revealed a statistically significant increase in cognitive performance and a decrease in negative affect in both squares. They also showed that participants reported greater stress recovery rates in one of the settings. These results support the idea that cities can be potentially restorative and justify the relevance of a research area focused on the urban designs, which may offer psychological benefits to urban citizens.
On squaring the primary constraints in a generalized Hamiltonian dynamics
International Nuclear Information System (INIS)
Nesterenko, V.V.
1993-01-01
Consideration of the model of the relativistic particle with curvature and torsion in the three-dimensional space-time shows that the squaring of the primary constraints entails a wrong result. The complete set of the Hamiltonian constraints arising here corresponds to another model with an action similar but not identical with the initial action. 16 refs
Some results on square-free colorings of graphs
DEFF Research Database (Denmark)
Barat, Janos
2004-01-01
on the vertices or edges of a path. Conversely one can form sequences from a vertex or edge coloring of a graph in different ways. Thus there are several possibilities to generalize the square-free concept to graphs. Following Alon, Grytczuk, Haluszczak, Riordan and Bresar, Klavzar we study several so called...... square-free graph parameters, and answer some questions they posed. The main result is that the class of k-trees has bounded square-free vertex coloring parameter. Thus we can color the vertices of a k-tree using O(c^k) colors if c>6 such that the color sequence on any path is square......-free. It is conjectured that a similar phenomenon holds for planar graphs, so a finite number of colors are enough. We support this conjecture by showing that this number is at most 12 for outerplanar graphs. On the other hand we prove that some outerplanar graphs require at least 7 colors. Using this latter we construct...
Wave-equation Q tomography and least-squares migration
Dutta, Gaurav
2016-03-01
This thesis designs new methods for Q tomography and Q-compensated prestack depth migration when the recorded seismic data suffer from strong attenuation. A motivation of this work is that the presence of gas clouds or mud channels in overburden structures leads to the distortion of amplitudes and phases in seismic waves propagating inside the earth. If the attenuation parameter Q is very strong, i.e., Q<30, ignoring the anelastic effects in imaging can lead to dimming of migration amplitudes and loss of resolution. This, in turn, adversely affects the ability to accurately predict reservoir properties below such layers. To mitigate this problem, I first develop an anelastic least-squares reverse time migration (Q-LSRTM) technique. I reformulate the conventional acoustic least-squares migration problem as a viscoacoustic linearized inversion problem. Using linearized viscoacoustic modeling and adjoint operators during the least-squares iterations, I show with numerical tests that Q-LSRTM can compensate for the amplitude loss and produce images with better balanced amplitudes than conventional migration. To estimate the background Q model that can be used for any Q-compensating migration algorithm, I then develop a wave-equation based optimization method that inverts for the subsurface Q distribution by minimizing a skeletonized misfit function ε. Here, ε is the sum of the squared differences between the observed and the predicted peak/centroid-frequency shifts of the early-arrivals. Through numerical tests on synthetic and field data, I show that noticeable improvements in the migration image quality can be obtained from Q models inverted using wave-equation Q tomography. A key feature of skeletonized inversion is that it is much less likely to get stuck in a local minimum than a standard waveform inversion method. Finally, I develop a preconditioning technique for least-squares migration using a directional Gabor-based preconditioning approach for isotropic
1991-01-01
More than 750 NASA, government, contractor, and academic representatives attended the Seventh Annual NASA/Contractors Conference on Quality and Productivity. The panel presentations and Keynote speeches revolving around the theme of total quality leadership provided a solid base of understanding of the importance, benefits, and principles of total quality management (TQM). The presentations from the conference are summarized.
Genoptraening efter total knaealloplastik
DEFF Research Database (Denmark)
Holm, Bente; Kehlet, Henrik
2009-01-01
The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty...
Iterating archival footage and the memory of war
Noordegraaf, J.; Bordina, A.; Campanini, S.; Mariani, A.
2012-01-01
In this article I focus on the archive as a specific site of memory, in particular the audiovisual archive. I investigate the use of audiovisual archival records as sources for remembering war, specifically the war in the former Yugoslavia (1991-1995). I do so by discussing one particular case
Fabrication of MTF measurement system for a mobile phone lens using multi-square objects
Hong, Sung Mok; Jo, Jae Heung; Lee, Hoi Youn; Yang, Ho Soon; Lee, Yun Woo; Lee, In Won
2007-12-01
The mobile phone market grows rapidly and the performance estimation about camera module is required. Accordingly, we fabricate the MTF measurement system for a mobile phone lens having extremely small diameter and large f-number. The objective lens with the magnification of X20 for MTF measurement for high resolution lens and a detector of CCD that is pixel size of 7.4 um are adapted to the system. Also, the CCD is translated by using a linear motor to reduce measurement errors. The measurement lens is placed at the most suitable imaging point by a precise auto-focusing motor. The measuring equipment which we developed for off-axis MTF measurement of a mobile phone lens used the multi-square objects. The square objects of measuring equipment are arranged a unit in the on-axis and total 12 units (0.3 field: 4 units, 0.5 field: 4 units, 0.7 field: 4 units) in the off-axis. When the measurement is started, the linear motors of signal detection part are transferred from on-axis to off-axis. And a detected signals from the each square objects are used for MTF measurement. System driver and MTF measure are using application program that developed us. This software can be measure the on-axis and the off-axis sequentially. In addition to that it did optimization of motor transfer for measurement time shortening.
Laparoscopic total pancreatectomy
Wang, Xin; Li, Yongbin; Cai, Yunqiang; Liu, Xubao; Peng, Bing
2017-01-01
Abstract Rationale: Laparoscopic total pancreatectomy is a complicated surgical procedure and rarely been reported. This study was conducted to investigate the safety and feasibility of laparoscopic total pancreatectomy. Patients and Methods: Three patients underwent laparoscopic total pancreatectomy between May 2014 and August 2015. We reviewed their general demographic data, perioperative details, and short-term outcomes. General morbidity was assessed using Clavien–Dindo classification and delayed gastric emptying (DGE) was evaluated by International Study Group of Pancreatic Surgery (ISGPS) definition. Diagnosis and Outcomes: The indications for laparoscopic total pancreatectomy were intraductal papillary mucinous neoplasm (IPMN) (n = 2) and pancreatic neuroendocrine tumor (PNET) (n = 1). All patients underwent laparoscopic pylorus and spleen-preserving total pancreatectomy, the mean operative time was 490 minutes (range 450–540 minutes), the mean estimated blood loss was 266 mL (range 100–400 minutes); 2 patients suffered from postoperative complication. All the patients recovered uneventfully with conservative treatment and discharged with a mean hospital stay 18 days (range 8–24 days). The short-term (from 108 to 600 days) follow up demonstrated 3 patients had normal and consistent glycated hemoglobin (HbA1c) level with acceptable quality of life. Lessons: Laparoscopic total pancreatectomy is feasible and safe in selected patients and pylorus and spleen preserving technique should be considered. Further prospective randomized studies are needed to obtain a comprehensive understanding the role of laparoscopic technique in total pancreatectomy. PMID:28099344
DEFF Research Database (Denmark)
Garcia, Emanuel; Klaas, Ilka Christine; Amigo Rubio, Jose Manuel
2014-01-01
Lameness is prevalent in dairy herds. It causes decreased animal welfare and leads to higher production costs. This study explored data from an automatic milking system (AMS) to model on-farm gait scoring from a commercial farm. A total of 88 cows were gait scored once per week, for 2 5-wk periods......). The reference gait scoring error was estimated in the first week of the study and was, on average, 15%. Two partial least squares discriminant analysis models were fitted to parity 1 and parity 2 groups, respectively, to assign the lameness class according to the predicted probability of being lame (score 3...
Directory of Open Access Journals (Sweden)
Ahmed Kadhim Hussein
2016-03-01
Full Text Available A steady laminar two-dimensional magneto-hydrodynamics (MHD natural convection flow in a square enclosure filled with an electrically conducting fluid is numerically investigated using Lattice Boltzmann Method (LBM. The left and right vertical sidewalls of the square enclosure are maintained at hot and cold temperatures respectively. The horizontal top and bottom walls are considered thermally insulated. An adiabatic square shaped body is located in the center of a square enclosure and an external magnetic field is applied parallel to the horizontal x-axis. In the present work, the following parametric ranges of the non-dimensional groups are utilized: Hartmann number is varied as 0 ⩽ Ha ⩽ 50, Rayleigh number is varied as 103 ⩽ Ra ⩽ 105, Prandtl number is varied 0.05 ⩽ Pr ⩽ 5. It is found that the Hartmann number, Rayleigh number, and Prandtl number have an important role on the flow and thermal characteristics. It is found that when the Hartmann number increases the average Nusselt number decreases. The results also explain that the effect of magnetic field on flow field increases by increasing Prandtl number. However, the Prandtl number effect on the average Nusselt number with a magnetic field is less than the case without a magnetic field. Comparisons with previously published numerical works are performed and good agreements between the results are observed.
Suliman, Mohamed Abdalla Elhag; Ballal, Tarig; Kammoun, Abla; Al-Naffouri, Tareq Y.
2016-01-01
This paper proposes a new approach to find the regularization parameter for linear least-squares discrete ill-posed problems. In the proposed approach, an artificial perturbation matrix with a bounded norm is forced into the discrete ill-posed model
International Nuclear Information System (INIS)
Patil, Pratish P; Tiwari, Shaligram
2009-01-01
The characteristics of unsteady wakes behind a stationary square cylinder and another upstream vibrating square cylinder have been investigated numerically with the help of a developed computational code. The effect of longitudinal as well as transverse vibrations of the upstream cylinder is studied on the coupled wake between the two cylinders, which is found to control the vortex shedding behavior behind the downstream stationary cylinder. Computations are carried out for a fixed value of Reynolds number (Re = 200) and three different values of excitation frequencies of the upstream cylinder, namely less than, equal to and greater than the natural frequency of vortex shedding corresponding to flow past a stationary square cylinder. The vortex shedding characteristics of the unsteady wakes behind the vibrating and stationary cylinders are found to differ significantly for longitudinal and transverse modes of vibration of the upstream cylinder. The wake of the downstream stationary cylinder is found to depict a synchronization behavior with the upstream cylinder vibration. The spacing between the two cylinders has been identified to be the key parameter influencing the synchronization phenomenon. The effect of cylinder spacing on the wake synchronization and the hydrodynamic forces has been examined. In addition, a comparison of the drag forces for flow past transversely vibrating square and circular cylinders for similar amplitudes and frequencies of cylinder vibration has been presented while employing the tested computational code.
Estonian total ozone climatology
Directory of Open Access Journals (Sweden)
K. Eerme
Full Text Available The climatological characteristics of total ozone over Estonia based on the Total Ozone Mapping Spectrometer (TOMS data are discussed. The mean annual cycle during 1979–2000 for the site at 58.3° N and 26.5° E is compiled. The available ground-level data interpolated before TOMS, have been used for trend detection. During the last two decades, the quasi-biennial oscillation (QBO corrected systematic decrease of total ozone from February–April was 3 ± 2.6% per decade. Before 1980, a spring decrease was not detectable. No decreasing trend was found in either the late autumn ozone minimum or in the summer total ozone. The QBO related signal in the spring total ozone has an amplitude of ± 20 DU and phase lag of 20 months. Between 1987–1992, the lagged covariance between the Singapore wind and the studied total ozone was weak. The spring (April–May and summer (June–August total ozone have the best correlation (coefficient 0.7 in the yearly cycle. The correlation between the May and August total ozone is higher than the one between the other summer months. Seasonal power spectra of the total ozone variance show preferred periods with an over 95% significance level. Since 1986, during the winter/spring, the contribution period of 32 days prevails instead of the earlier dominating 26 days. The spectral densities of the periods from 4 days to 2 weeks exhibit high interannual variability.
Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry; volcanic effects – Meteorology and atmospheric dynamics (climatology
International Nuclear Information System (INIS)
Carlos, P.
1985-06-01
The present discussion is limited to a presentation of the most recent total photonuclear absorption experiments performed with real photons at intermediate energy, and more precisely in the region of nucleon resonances. The main sources of real photons are briefly reviewed and the experimental procedures used for total photonuclear absorption cross section measurements. The main results obtained below 140 MeV photon energy as well as above 2 GeV are recalled. The experimental study of total photonuclear absorption in the nuclear resonance region (140 MeV< E<2 GeV) is still at its beginning and some results are presented
Antretter, H; Dumfarth, J; Höfer, D
2015-09-01
To date the CardioWest™ total artificial heart is the only clinically available implantable biventricular mechanical replacement for irreversible cardiac failure. This article presents the indications, contraindications, implantation procedere and postoperative treatment. In addition to a overview of the applications of the total artificial heart this article gives a brief presentation of the two patients treated in our department with the CardioWest™. The clinical course, postoperative rehabilitation, device-related complications and control mechanisms are presented. The total artificial heart is a reliable implant for treating critically ill patients with irreversible cardiogenic shock. A bridge to transplantation is feasible with excellent results.
Liao, Xiang; Wang, Qing; Fu, Ji-hong; Tang, Jun
2015-09-01
This work was undertaken to establish a quantitative analysis model which can rapid determinate the content of linalool, linalyl acetate of Xinjiang lavender essential oil. Totally 165 lavender essential oil samples were measured by using near infrared absorption spectrum (NIR), after analyzing the near infrared spectral absorption peaks of all samples, lavender essential oil have abundant chemical information and the interference of random noise may be relatively low on the spectral intervals of 7100~4500 cm(-1). Thus, the PLS models was constructed by using this interval for further analysis. 8 abnormal samples were eliminated. Through the clustering method, 157 lavender essential oil samples were divided into 105 calibration set samples and 52 validation set samples. Gas chromatography mass spectrometry (GC-MS) was used as a tool to determine the content of linalool and linalyl acetate in lavender essential oil. Then the matrix was established with the GC-MS raw data of two compounds in combination with the original NIR data. In order to optimize the model, different pretreatment methods were used to preprocess the raw NIR spectral to contrast the spectral filtering effect, after analysizing the quantitative model results of linalool and linalyl acetate, the root mean square error prediction (RMSEP) of orthogonal signal transformation (OSC) was 0.226, 0.558, spectrally, it was the optimum pretreatment method. In addition, forward interval partial least squares (FiPLS) method was used to exclude the wavelength points which has nothing to do with determination composition or present nonlinear correlation, finally 8 spectral intervals totally 160 wavelength points were obtained as the dataset. Combining the data sets which have optimized by OSC-FiPLS with partial least squares (PLS) to establish a rapid quantitative analysis model for determining the content of linalool and linalyl acetate in Xinjiang lavender essential oil, numbers of hidden variables of two
International Nuclear Information System (INIS)
2005-02-01
This document presents the 2004 results of Total Group: consolidated account, special items, number of shares, market environment, adjustment for amortization of Sanofi-Aventis merger-related intangibles, 4. quarter 2004 results (operating and net incomes, cash flow), upstream (results, production, reserves, recent highlights), downstream (results, refinery throughput, recent highlights), chemicals (results, recent highlights), Total's full year 2004 results (operating and net income, cash flow), 2005 sensitivities, Total SA parent company accounts and proposed dividend, adoption of IFRS accounting, summary and outlook, main operating information by segment for the 4. quarter and full year 2004: upstream (combined liquids and gas production by region, liquids production by region, gas production by region), downstream (refined product sales by region, chemicals), Total financial statements: consolidated statement of income, consolidated balance sheet (assets, liabilities and shareholder's equity), consolidated statements of cash flows, business segments information. (J.S.)
Total synthesis of ciguatoxin.
Hamajima, Akinari; Isobe, Minoru
2009-01-01
Something fishy: Ciguatoxin (see structure) is one of the principal toxins involved in ciguatera poisoning and the target of a total synthesis involving the coupling of three segments. The key transformations in this synthesis feature acetylene-dicobalthexacarbonyl complexation.
Energy Technology Data Exchange (ETDEWEB)
NONE
2005-02-01
This document presents the 2004 results of Total Group: consolidated account, special items, number of shares, market environment, adjustment for amortization of Sanofi-Aventis merger-related intangibles, 4. quarter 2004 results (operating and net incomes, cash flow), upstream (results, production, reserves, recent highlights), downstream (results, refinery throughput, recent highlights), chemicals (results, recent highlights), Total's full year 2004 results (operating and net income, cash flow), 2005 sensitivities, Total SA parent company accounts and proposed dividend, adoption of IFRS accounting, summary and outlook, main operating information by segment for the 4. quarter and full year 2004: upstream (combined liquids and gas production by region, liquids production by region, gas production by region), downstream (refined product sales by region, chemicals), Total financial statements: consolidated statement of income, consolidated balance sheet (assets, liabilities and shareholder's equity), consolidated statements of cash flows, business segments information. (J.S.)
Genoptraening efter total knaealloplastik
DEFF Research Database (Denmark)
Holm, Bente; Kehlet, Henrik
2009-01-01
The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty rehabilitat......The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty...... rehabilitation. Since hospital stay duration has decreased considerably, the need for post-discharge physiotherapy may also have changed. Thus, the indication for and types of rehabilitation programmes need to be studied within the context of fast-track knee arthroplasty....
Genoptraening efter total knaealloplastik
DEFF Research Database (Denmark)
Holm, Bente; Kehlet, Henrik
2009-01-01
The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty rehabilitat......The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty...... rehabilitation. Since hospital stay duration has decreased considerably, the need for post-discharge physiotherapy may also have changed. Thus, the indication for and types of rehabilitation programmes need to be studied within the context of fast-track knee arthroplasty. Udgivelsesdato: 2009-Feb-23...
Supravaginal eller total hysterektomi?
DEFF Research Database (Denmark)
Edvardsen, L; Madsen, E M
1994-01-01
There has been a decline in the rate of hysterectomies in Denmark in general over the last thirteen years, together with a rise in the number of supravaginal operations over the last two years. The literature concerning the relative merits of the supravaginal and the total abdominal operation is ...... indicate a reduced frequency of orgasm after the total hysterectomy compared with the supravaginal operation. When there are technical problems peroperatively with an increased urologic risk the supravaginal operation is recommended....
International Nuclear Information System (INIS)
Sutherland, D.E.; Ferguson, R.M.; Simmons, R.L.; Kim, T.H.; Slavin, S.; Najarian, J.S.
1983-01-01
Total lymphoid irradiation by itself can produce sufficient immunosuppression to prolong the survival of a variety of organ allografts in experimental animals. The degree of prolongation is dose-dependent and is limited by the toxicity that occurs with higher doses. Total lymphoid irradiation is more effective before transplantation than after, but when used after transplantation can be combined with pharmacologic immunosuppression to achieve a positive effect. In some animal models, total lymphoid irradiation induces an environment in which fully allogeneic bone marrow will engraft and induce permanent chimerism in the recipients who are then tolerant to organ allografts from the donor strain. If total lymphoid irradiation is ever to have clinical applicability on a large scale, it would seem that it would have to be under circumstances in which tolerance can be induced. However, in some animal models graft-versus-host disease occurs following bone marrow transplantation, and methods to obviate its occurrence probably will be needed if this approach is to be applied clinically. In recent years, patient and graft survival rates in renal allograft recipients treated with conventional immunosuppression have improved considerably, and thus the impetus to utilize total lymphoid irradiation for its immunosuppressive effect alone is less compelling. The future of total lymphoid irradiation probably lies in devising protocols in which maintenance immunosuppression can be eliminated, or nearly eliminated, altogether. Such protocols are effective in rodents. Whether they can be applied to clinical transplantation remains to be seen
Totally optimal decision rules
Amin, Talha
2017-11-22
Optimality of decision rules (patterns) can be measured in many ways. One of these is referred to as length. Length signifies the number of terms in a decision rule and is optimally minimized. Another, coverage represents the width of a rule’s applicability and generality. As such, it is desirable to maximize coverage. A totally optimal decision rule is a decision rule that has the minimum possible length and the maximum possible coverage. This paper presents a method for determining the presence of totally optimal decision rules for “complete” decision tables (representations of total functions in which different variables can have domains of differing values). Depending on the cardinalities of the domains, we can either guarantee for each tuple of values of the function that totally optimal rules exist for each row of the table (as in the case of total Boolean functions where the cardinalities are equal to 2) or, for each row, we can find a tuple of values of the function for which totally optimal rules do not exist for this row.
Totally optimal decision rules
Amin, Talha M.; Moshkov, Mikhail
2017-01-01
Optimality of decision rules (patterns) can be measured in many ways. One of these is referred to as length. Length signifies the number of terms in a decision rule and is optimally minimized. Another, coverage represents the width of a rule’s applicability and generality. As such, it is desirable to maximize coverage. A totally optimal decision rule is a decision rule that has the minimum possible length and the maximum possible coverage. This paper presents a method for determining the presence of totally optimal decision rules for “complete” decision tables (representations of total functions in which different variables can have domains of differing values). Depending on the cardinalities of the domains, we can either guarantee for each tuple of values of the function that totally optimal rules exist for each row of the table (as in the case of total Boolean functions where the cardinalities are equal to 2) or, for each row, we can find a tuple of values of the function for which totally optimal rules do not exist for this row.
Steady squares and hexagons on a subcritical ramp
International Nuclear Information System (INIS)
Hoyle, R.B.
1995-01-01
Steady squares and hexagons on a subcritical ramp are studied, both analytically and numerically, within the framework of the lowest-order amplitude equations. On the subcritical ramp, the external stress or control parameter varies continuously in space from subcritical to supercritical values. At the subcritical end of the ramp, pattern formation is suppressed, and patterns fade away into the conduction solution. It is shown that three-dimensional patterns may change shape on a subcritical ramp. A square pattern becomes a pattern of rolls as it fades, with the roll axes aligned in the direction orthogonal to that in which the control parameter varies. Hexagons in systems with horizontal midplane symmetry become a pattern of rectangles before reaching the conduction solution. There is a suggestion that hexagons in systems which lack this symmetry might fade away through a roll pattern. Numerical simulations are used to illustrate these phenomena
Linearized least-square imaging of internally scattered data
Aldawood, Ali; Hoteit, Ibrahim; Turkiyyah, George M.; Zuberi, M. A H; Alkhalifah, Tariq Ali
2014-01-01
Internal multiples deteriorate the quality of the migrated image obtained conventionally by imaging single scattering energy. However, imaging internal multiples properly has the potential to enhance the migrated image because they illuminate zones in the subsurface that are poorly illuminated by single-scattering energy such as nearly vertical faults. Standard migration of these multiples provide subsurface reflectivity distributions with low spatial resolution and migration artifacts due to the limited recording aperture, coarse sources and receivers sampling, and the band-limited nature of the source wavelet. Hence, we apply a linearized least-square inversion scheme to mitigate the effect of the migration artifacts, enhance the spatial resolution, and provide more accurate amplitude information when imaging internal multiples. Application to synthetic data demonstrated the effectiveness of the proposed inversion in imaging a reflector that is poorly illuminated by single-scattering energy. The least-square inversion of doublescattered data helped delineate that reflector with minimal acquisition fingerprint.
An information geometric approach to least squares minimization
Transtrum, Mark; Machta, Benjamin; Sethna, James
2009-03-01
Parameter estimation by nonlinear least squares minimization is a ubiquitous problem that has an elegant geometric interpretation: all possible parameter values induce a manifold embedded within the space of data. The minimization problem is then to find the point on the manifold closest to the origin. The standard algorithm for minimizing sums of squares, the Levenberg-Marquardt algorithm, also has geometric meaning. When the standard algorithm fails to efficiently find accurate fits to the data, geometric considerations suggest improvements. Problems involving large numbers of parameters, such as often arise in biological contexts, are notoriously difficult. We suggest an algorithm based on geodesic motion that may offer improvements over the standard algorithm for a certain class of problems.
Unweighted least squares phase unwrapping by means of multigrid techniques
Pritt, Mark D.
1995-11-01
We present a multigrid algorithm for unweighted least squares phase unwrapping. This algorithm applies Gauss-Seidel relaxation schemes to solve the Poisson equation on smaller, coarser grids and transfers the intermediate results to the finer grids. This approach forms the basis of our multigrid algorithm for weighted least squares phase unwrapping, which is described in a separate paper. The key idea of our multigrid approach is to maintain the partial derivatives of the phase data in separate arrays and to correct these derivatives at the boundaries of the coarser grids. This maintains the boundary conditions necessary for rapid convergence to the correct solution. Although the multigrid algorithm is an iterative algorithm, we demonstrate that it is nearly as fast as the direct Fourier-based method. We also describe how to parallelize the algorithm for execution on a distributed-memory parallel processor computer or a network-cluster of workstations.
Estimating Frequency by Interpolation Using Least Squares Support Vector Regression
Directory of Open Access Journals (Sweden)
Changwei Ma
2015-01-01
Full Text Available Discrete Fourier transform- (DFT- based maximum likelihood (ML algorithm is an important part of single sinusoid frequency estimation. As signal to noise ratio (SNR increases and is above the threshold value, it will lie very close to Cramer-Rao lower bound (CRLB, which is dependent on the number of DFT points. However, its mean square error (MSE performance is directly proportional to its calculation cost. As a modified version of support vector regression (SVR, least squares SVR (LS-SVR can not only still keep excellent capabilities for generalizing and fitting but also exhibit lower computational complexity. In this paper, therefore, LS-SVR is employed to interpolate on Fourier coefficients of received signals and attain high frequency estimation accuracy. Our results show that the proposed algorithm can make a good compromise between calculation cost and MSE performance under the assumption that the sample size, number of DFT points, and resampling points are already known.
Characterization of turbulent coherent structures in square duct flow
Atzori, Marco; Vinuesa, Ricardo; Lozano-Durán, Adrián; Schlatter, Philipp
2018-04-01
This work is aimed at a first characterization of coherent structures in turbulent square duct flows. Coherent structures are defined as connected components in the domain identified as places where a quantity of interest (such as Reynolds stress or vorticity) is larger than a prescribed non-uniform threshold. Firstly, we qualitatively discuss how a percolation analysis can be used to assess the effectiveness of the threshold function, and how it can be affected by statistical uncertainty. Secondly, various physical quantities that are expected to play an important role in the dynamics of the secondary flow of Prandtl’s second kind are studied. Furthermore, a characterization of intense Reynolds-stress events in square duct flow, together with a comparison of their shape for analogous events in channel flow at the same Reynolds number, is presented.
Stability analysis of the Peregrine solution via squared eigenfunctions
Schober, C. M.; Strawn, M.
2017-10-01
A preliminary numerical investigation involving ensembles of perturbed initial data for the Peregrine soliton (the lowest order rational solution of the nonlinear Schrödinger equation) indicates that it is unstable [16]. In this paper we analytically investigate the linear stability of the Peregrine soliton, appealing to the fact that the Peregrine solution can be viewed as the singular limit of a single mode spatially periodic breathers (SPB). The "squared eigenfunction" connection between the Zakharov-Shabat (Z-S) system and the linearized NLS equation is employed in the stability analysis. Specifically, we determine the eigenfunctions of the Z-S system associated with the Peregrine soliton and construct a family of solutions of the associated linearized NLS (about the Peregrine) in terms of quadratic products of components of the eigenfunctions (i.e., the squared eigenfunction). We find there exist solutions of the linearization that grow exponentially in time, thus showing the Peregrine soliton is linearly unstable.
Sub-Millimeter Tests of the Newtonian Inverse Square Law
International Nuclear Information System (INIS)
Adelberger, Eric
2005-01-01
It is remarkable that small-scale experiments can address important open issues in fundamental science such as: 'why is gravity so weak compared to the other interactions?' and 'why is the cosmological constant so small compared to the predictions of quantum mechanics?' String theory ideas (new scalar particles and extra dimensions) and other notions hint that Newton's Inverse-Square Law could break down at distances less than 1 mm. I will review some motivations for testing the Inverse-Square Law, and discuss recent mechanical experiments with torsion balances, small-scillators, micro-cantilevers, and ultra-cold neutrons. Our torsion-balance experiments have probed for gravitational-strength interactions with length scales down to 70 micrometers, which is approximately the diameter of a human hair.
Source allocation by least-squares hydrocarbon fingerprint matching
Energy Technology Data Exchange (ETDEWEB)
William A. Burns; Stephen M. Mudge; A. Edward Bence; Paul D. Boehm; John S. Brown; David S. Page; Keith R. Parker [W.A. Burns Consulting Services LLC, Houston, TX (United States)
2006-11-01
There has been much controversy regarding the origins of the natural polycyclic aromatic hydrocarbon (PAH) and chemical biomarker background in Prince William Sound (PWS), Alaska, site of the 1989 Exxon Valdez oil spill. Different authors have attributed the sources to various proportions of coal, natural seep oil, shales, and stream sediments. The different probable bioavailabilities of hydrocarbons from these various sources can affect environmental damage assessments from the spill. This study compares two different approaches to source apportionment with the same data (136 PAHs and biomarkers) and investigate whether increasing the number of coal source samples from one to six increases coal attributions. The constrained least-squares (CLS) source allocation method that fits concentrations meets geologic and chemical constraints better than partial least-squares (PLS) which predicts variance. The field data set was expanded to include coal samples reported by others, and CLS fits confirm earlier findings of low coal contributions to PWS. 15 refs., 5 figs.
Least-Square Prediction for Backward Adaptive Video Coding
Directory of Open Access Journals (Sweden)
Li Xin
2006-01-01
Full Text Available Almost all existing approaches towards video coding exploit the temporal redundancy by block-matching-based motion estimation and compensation. Regardless of its popularity, block matching still reflects an ad hoc understanding of the relationship between motion and intensity uncertainty models. In this paper, we present a novel backward adaptive approach, named "least-square prediction" (LSP, and demonstrate its potential in video coding. Motivated by the duality between edge contour in images and motion trajectory in video, we propose to derive the best prediction of the current frame from its causal past using least-square method. It is demonstrated that LSP is particularly effective for modeling video material with slow motion and can be extended to handle fast motion by temporal warping and forward adaptation. For typical QCIF test sequences, LSP often achieves smaller MSE than , full-search, quarter-pel block matching algorithm (BMA without the need of transmitting any overhead.
Least squares orthogonal polynomial approximation in several independent variables
International Nuclear Information System (INIS)
Caprari, R.S.
1992-06-01
This paper begins with an exposition of a systematic technique for generating orthonormal polynomials in two independent variables by application of the Gram-Schmidt orthogonalization procedure of linear algebra. It is then demonstrated how a linear least squares approximation for experimental data or an arbitrary function can be generated from these polynomials. The least squares coefficients are computed without recourse to matrix arithmetic, which ensures both numerical stability and simplicity of implementation as a self contained numerical algorithm. The Gram-Schmidt procedure is then utilised to generate a complete set of orthogonal polynomials of fourth degree. A theory for the transformation of the polynomial representation from an arbitrary basis into the familiar sum of products form is presented, together with a specific implementation for fourth degree polynomials. Finally, the computational integrity of this algorithm is verified by reconstructing arbitrary fourth degree polynomials from their values at randomly chosen points in their domain. 13 refs., 1 tab
Arts@CERN | ACCELERATE Austria | 19 May | IdeaSquare
2016-01-01
Arts@CERN welcomes you to a talk by architects Sandra Manninger and Matias Del Campo, at IdeaSquare (Point 1) on May 19 at 6:00 p.m. Sensible Bodies - architecture, data, and desire. Sandra and Matias are the winning architects for ACCELERATE Austria. Focusing on the notion of geometry, they are at CERN during the month of May, as artists in residence. Their research highlights how to go beyond beautiful data to discover something that could be defined voluptuous data. This coagulation of numbers, algorithms, procedures and programs uses the forces of thriving nature and, passing through the calculation of a multi-core processor, knits them with human desire. Read more. ACCELERATE Austria is supported by The Department of Arts of the Federal Chancellery of Austria. Thursday, May 19 at 6:00 p.m. at IdeaSquare. See event on Indico.
The central subgroup of the nonabelian tensor square of Bieberbach ...
African Journals Online (AJOL)
A Bieberbach group with point group C2 xC2 is a free torsion crystallographic group. A central subgroup of a nonabelian tensor square of a group G, denoted by ∇(G) is a normal subgroup generated by generator g⊗g for all g∈G and essentially depends on the abelianization of the group. In this paper, the formula of the ...
Anisotropic square lattice Potts ferromagnet: renormalization group treatment
International Nuclear Information System (INIS)
Oliveira, P.M.C. de; Tsallis, C.
1981-01-01
The choice of a convenient self-dual cell within a real space renormalization group framework enables a satisfactory treatment of the anisotropic square lattice q-state Potts ferromagnet criticality. The exact critical frontier and dimensionality crossover exponent PHI as well as the expected universality behaviour (renormalization flow sense) are recovered for any linear scaling factor b and all values of q(q - [pt
Regularized Partial Least Squares with an Application to NMR Spectroscopy
Allen, Genevera I.; Peterson, Christine; Vannucci, Marina; Maletic-Savatic, Mirjana
2012-01-01
High-dimensional data common in genomics, proteomics, and chemometrics often contains complicated correlation structures. Recently, partial least squares (PLS) and Sparse PLS methods have gained attention in these areas as dimension reduction techniques in the context of supervised data analysis. We introduce a framework for Regularized PLS by solving a relaxation of the SIMPLS optimization problem with penalties on the PLS loadings vectors. Our approach enjoys many advantages including flexi...
Algebraic K-theory and sums-of-squares formulas
Dugger, Daniel; Isaksen, Daniel C.
2004-01-01
We prove a result about the non-existence of certain sums-of-squares formulas over a field. This generalizes an old theorem which used topological K-theory to obtain obstruction conditions when the field is the real numbers. Our result applies to arbitrary fields not of characteristic 2, making use of algebraic K-theory in place of topological K-theory.
Market Structure and Competitive Strategy in Market Square
Institute of Scientific and Technical Information of China (English)
PENG Juanjuan
2007-01-01
Market Square shopping center contains several restaurants and cafés providing a diverse range of Asian foods and delicacies and this area is known by locals and Griffith University students as a great location for 'eating out'. Then, what is the market structure in this shopping mall and what kind of competitive strategies should be used to maximize profits according to the characteristics in this shopping center?
Covering an uncountable square by countable many continuous functions
Czech Academy of Sciences Publication Activity Database
Kubiś, Wieslaw; Vejnar, B.
2012-01-01
Roč. 140, č. 12 (2012), s. 4359-4368 ISSN 0002-9939 R&D Projects: GA AV ČR IAA100190901 Institutional research plan: CEZ:AV0Z10190503 Keywords : uncountable square * covering by continuous functions * set of cardinality N-1 Subject RIV: BA - General Mathematics Impact factor: 0.609, year: 2012 http://www.ams.org/journals/proc/2012-140-12/S0002-9939-2012-11292-4/home.html
Dose rate from the square volume radiation source
International Nuclear Information System (INIS)
Karpov, V.I.
1978-01-01
The expression for determining the dose rate from a three-dimensional square flat-parallel source of any dimensions is obtained. A simplified method for integrating the resultant expression is proposed. A comparison of the calculation results with the results by the Monte Carlo method has shown them to coincide within 6-8%. Since buildings and structures consist of rectangular elements, the method is recommended for practical calculations of dose rates in residential buildings
Adaptive Noise Canceling Menggunakan Algoritma Least Mean Square (Lms)
Nardiana, Anita; Sumaryono, Sari Sujoko
2011-01-01
Noise is inevitable in communication system. In some cases, noise can disturb signal. It is veryannoying as the received signal is jumbled with the noise itself. To reduce or remove noise, filter lowpass,highpass or bandpass can solve the problems, but this method cannot reach a maximum standard. One ofthe alternatives to solve the problem is by using adaptive filter. Adaptive algorithm frequently used is LeastMean Square (LMS) Algorithm which is compatible to Finite Impulse Response (FIR). T...
Capillary condensation in a square geometry with surface fields.
Zubaszewska, M; Gendiar, A; Drzewiński, A
2012-12-01
We study the influence of wetting on capillary condensation for a simple fluid in a square geometry with surface fields, where the reference system is an infinitely long slit. The corner transfer matrix renormalization group method has been extended to study a two-dimensional Ising model confined in an L × L geometry with equal surface fields. Our results have confirmed that in both geometries the coexistence line shift is governed by the same scaling powers, but their prefactors are different.
A FORTRAN program for a least-square fitting
International Nuclear Information System (INIS)
Yamazaki, Tetsuo
1978-01-01
A practical FORTRAN program for a least-squares fitting is presented. Although the method is quite usual, the program calculates not only the most satisfactory set of values of unknowns but also the plausible errors associated with them. As an example, a measured lateral absorbed-dose distribution in water for a narrow 25-MeV electron beam is fitted to a Gaussian distribution. (auth.)
Analysis of quantile regression as alternative to ordinary least squares
Ibrahim Abdullahi; Abubakar Yahaya
2015-01-01
In this article, an alternative to ordinary least squares (OLS) regression based on analytical solution in the Statgraphics software is considered, and this alternative is no other than quantile regression (QR) model. We also present goodness of fit statistic as well as approximate distributions of the associated test statistics for the parameters. Furthermore, we suggest a goodness of fit statistic called the least absolute deviation (LAD) coefficient of determination. The procedure is well ...
Tunnelling of plane waves through a square barrier
Energy Technology Data Exchange (ETDEWEB)
Julve, J [IMAFF, Consejo Superior de Investigaciones CientIficas, Serrano 113 bis, Madrid 28006 (Spain); UrrIes, F J de [Departamento de Fisica, Universidad de Alcala de Henares, Alcala de Henares, Madrid (Spain)], E-mail: julve@imaff.cfmac.csic.es, E-mail: fernando.urries@uah.es
2008-08-01
The time evolution of plane waves in the presence of a one-dimensional square quantum barrier is considered. Comparison is made between the cases of an infinite and a cut-off (shutter) initial plane wave. The difference is relevant when the results are applied to the analysis of the tunnelling regime. This work is focused on the analytical calculation of the time-evolved solution and highlights the contribution of the resonant (Gamow) states.
Earthquake Source Spectral Study beyond the Omega-Square Model
Uchide, T.; Imanishi, K.
2017-12-01
Earthquake source spectra have been used for characterizing earthquake source processes quantitatively and, at the same time, simply, so that we can analyze the source spectra for many earthquakes, especially for small earthquakes, at once and compare them each other. A standard model for the source spectra is the omega-square model, which has the flat spectrum and the falloff inversely proportional to the square of frequencies at low and high frequencies, respectively, which are bordered by a corner frequency. The corner frequency has often been converted to the stress drop under the assumption of circular crack models. However, recent studies claimed the existence of another corner frequency [Denolle and Shearer, 2016; Uchide and Imanishi, 2016] thanks to the recent development of seismic networks. We have found that many earthquakes in areas other than the area studied by Uchide and Imanishi [2016] also have source spectra deviating from the omega-square model. Another part of the earthquake spectra we now focus on is the falloff rate at high frequencies, which will affect the seismic energy estimation [e.g., Hirano and Yagi, 2017]. In June, 2016, we deployed seven velocity seismometers in the northern Ibaraki prefecture, where the shallow crustal seismicity mainly with normal-faulting events was activated by the 2011 Tohoku-oki earthquake. We have recorded seismograms at 1000 samples per second and at a short distance from the source, so that we can investigate the high-frequency components of the earthquake source spectra. Although we are still in the stage of discovery and confirmation of the deviation from the standard omega-square model, the update of the earthquake source spectrum model will help us systematically extract more information on the earthquake source process.
Multisplitting for linear, least squares and nonlinear problems
Energy Technology Data Exchange (ETDEWEB)
Renaut, R.
1996-12-31
In earlier work, presented at the 1994 Iterative Methods meeting, a multisplitting (MS) method of block relaxation type was utilized for the solution of the least squares problem, and nonlinear unconstrained problems. This talk will focus on recent developments of the general approach and represents joint work both with Andreas Frommer, University of Wupertal for the linear problems and with Hans Mittelmann, Arizona State University for the nonlinear problems.
Multi-source least-squares reverse time migration
Dai, Wei
2012-06-15
Least-squares migration has been shown to improve image quality compared to the conventional migration method, but its computational cost is often too high to be practical. In this paper, we develop two numerical schemes to implement least-squares migration with the reverse time migration method and the blended source processing technique to increase computation efficiency. By iterative migration of supergathers, which consist in a sum of many phase-encoded shots, the image quality is enhanced and the crosstalk noise associated with the encoded shots is reduced. Numerical tests on 2D HESS VTI data show that the multisource least-squares reverse time migration (LSRTM) algorithm suppresses migration artefacts, balances the amplitudes, improves image resolution and reduces crosstalk noise associated with the blended shot gathers. For this example, the multisource LSRTM is about three times faster than the conventional RTM method. For the 3D example of the SEG/EAGE salt model, with a comparable computational cost, multisource LSRTM produces images with more accurate amplitudes, better spatial resolution and fewer migration artefacts compared to conventional RTM. The empirical results suggest that multisource LSRTM can produce more accurate reflectivity images than conventional RTM does with a similar or less computational cost. The caveat is that the LSRTM image is sensitive to large errors in the migration velocity model. © 2012 European Association of Geoscientists & Engineers.
Bounded Perturbation Regularization for Linear Least Squares Estimation
Ballal, Tarig
2017-10-18
This paper addresses the problem of selecting the regularization parameter for linear least-squares estimation. We propose a new technique called bounded perturbation regularization (BPR). In the proposed BPR method, a perturbation with a bounded norm is allowed into the linear transformation matrix to improve the singular-value structure. Following this, the problem is formulated as a min-max optimization problem. Next, the min-max problem is converted to an equivalent minimization problem to estimate the unknown vector quantity. The solution of the minimization problem is shown to converge to that of the ℓ2 -regularized least squares problem, with the unknown regularizer related to the norm bound of the introduced perturbation through a nonlinear constraint. A procedure is proposed that combines the constraint equation with the mean squared error (MSE) criterion to develop an approximately optimal regularization parameter selection algorithm. Both direct and indirect applications of the proposed method are considered. Comparisons with different Tikhonov regularization parameter selection methods, as well as with other relevant methods, are carried out. Numerical results demonstrate that the proposed method provides significant improvement over state-of-the-art methods.
Decision-Directed Recursive Least Squares MIMO Channels Tracking
Directory of Open Access Journals (Sweden)
Karami Ebrahim
2006-01-01
Full Text Available A new approach for joint data estimation and channel tracking for multiple-input multiple-output (MIMO channels is proposed based on the decision-directed recursive least squares (DD-RLS algorithm. RLS algorithm is commonly used for equalization and its application in channel estimation is a novel idea. In this paper, after defining the weighted least squares cost function it is minimized and eventually the RLS MIMO channel estimation algorithm is derived. The proposed algorithm combined with the decision-directed algorithm (DDA is then extended for the blind mode operation. From the computational complexity point of view being versus the number of transmitter and receiver antennas, the proposed algorithm is very efficient. Through various simulations, the mean square error (MSE of the tracking of the proposed algorithm for different joint detection algorithms is compared with Kalman filtering approach which is one of the most well-known channel tracking algorithms. It is shown that the performance of the proposed algorithm is very close to Kalman estimator and that in the blind mode operation it presents a better performance with much lower complexity irrespective of the need to know the channel model.
Twin edge colorings of certain square graphs and product graphs
Directory of Open Access Journals (Sweden)
R Rajarajachozhan
2016-04-01
Full Text Available A twin edge $k\\!$-coloring of a graph $G$ is a proper edge $k$-coloring of $G$ with the elements of $\\mathbb{Z}_k$ so that the induced vertex $k$-coloring, in which the color of a vertex $v$ in $G$ is the sum in $\\mathbb{Z}_k$ of the colors of the edges incident with $v,$ is a proper vertex $k\\!$-coloring. The minimum $k$ for which $G$ has a twin edge $k\\!$-coloring is called the twin chromatic index of $G.$ Twin chromatic index of the square $P_n^2,$ $n\\ge 4,$ and the square $C_n^2,$ $n\\ge 6,$ are determined. In fact, the twin chromatic index of the square $C_7^2$ is $\\Delta+2,$ where $\\Delta$ is the maximum degree. Twin chromatic index of $C_m\\,\\Box\\,P_n$ is determined, where $\\Box$ denotes the Cartesian product. $C_r$ and $P_r$ are, respectively, the cycle, and the path on $r$ vertices each.
Multi-source least-squares reverse time migration
Dai, Wei; Fowler, Paul J.; Schuster, Gerard T.
2012-01-01
Least-squares migration has been shown to improve image quality compared to the conventional migration method, but its computational cost is often too high to be practical. In this paper, we develop two numerical schemes to implement least-squares migration with the reverse time migration method and the blended source processing technique to increase computation efficiency. By iterative migration of supergathers, which consist in a sum of many phase-encoded shots, the image quality is enhanced and the crosstalk noise associated with the encoded shots is reduced. Numerical tests on 2D HESS VTI data show that the multisource least-squares reverse time migration (LSRTM) algorithm suppresses migration artefacts, balances the amplitudes, improves image resolution and reduces crosstalk noise associated with the blended shot gathers. For this example, the multisource LSRTM is about three times faster than the conventional RTM method. For the 3D example of the SEG/EAGE salt model, with a comparable computational cost, multisource LSRTM produces images with more accurate amplitudes, better spatial resolution and fewer migration artefacts compared to conventional RTM. The empirical results suggest that multisource LSRTM can produce more accurate reflectivity images than conventional RTM does with a similar or less computational cost. The caveat is that the LSRTM image is sensitive to large errors in the migration velocity model. © 2012 European Association of Geoscientists & Engineers.
Optimization of the geometrical stability in square ring laser gyroscopes
International Nuclear Information System (INIS)
Santagata, R; Beghi, A; Cuccato, D; Belfi, J; Beverini, N; Virgilio, A Di; Ortolan, A; Porzio, A; Solimeno, S
2015-01-01
Ultra-sensitive ring laser gyroscopes are regarded as potential detectors of the general relativistic frame-dragging effect due to the rotation of the Earth. Our project for this goal is called GINGER (gyroscopes in general relativity), and consists of a ground-based triaxial array of ring lasers aimed at measuring the rotation rate of the Earth with an accuracy of 10 −14 rad s −1 . Such an ambitious goal is now within reach, as large-area ring lasers are very close to the required sensitivity and stability. However, demanding constraints on the geometrical stability of the optical path of the laser inside the ring cavity are required. Thus, we have begun a detailed study of the geometry of an optical cavity in order to find a control strategy for its geometry that could meet the specifications of the GINGER project. As the cavity perimeter has a stationary point for the square configuration, we identify a set of transformations on the mirror positions that allows us to adjust the laser beam steering to the shape of a square. We show that the geometrical stability of a square cavity strongly increases by implementing a suitable system to measure the mirror distances, and that the geometry stabilization can be achieved by measuring the absolute lengths of the two diagonals and the perimeter of the ring. (paper)
Solving linear inequalities in a least squares sense
Energy Technology Data Exchange (ETDEWEB)
Bramley, R.; Winnicka, B. [Indiana Univ., Bloomington, IN (United States)
1994-12-31
Let A {element_of} {Re}{sup mxn} be an arbitrary real matrix, and let b {element_of} {Re}{sup m} a given vector. A familiar problem in computational linear algebra is to solve the system Ax = b in a least squares sense; that is, to find an x* minimizing {parallel}Ax {minus} b{parallel}, where {parallel} {center_dot} {parallel} refers to the vector two-norm. Such an x* solves the normal equations A{sup T}(Ax {minus} b) = 0, and the optimal residual r* = b {minus} Ax* is unique (although x* need not be). The least squares problem is usually interpreted as corresponding to multiple observations, represented by the rows of A and b, on a vector of data x. The observations may be inconsistent, and in this case a solution is sought that minimizes the norm of the residuals. A less familiar problem to numerical linear algebraists is the solution of systems of linear inequalities Ax {le} b in a least squares sense, but the motivation is similar: if a set of observations places upper or lower bounds on linear combinations of variables, the authors want to find x* minimizing {parallel} (Ax {minus} b){sub +} {parallel}, where the i{sup th} component of the vector v{sub +} is the maximum of zero and the i{sup th} component of v.
DEFF Research Database (Denmark)
Chinapaw, Mai; Klakk, Heidi; Møller, Niels Christian
2018-01-01
BACKGROUND/OBJECTIVES: Examine the prospective relationship of total volume versus bouts of sedentary behaviour (SB) and moderate-to-vigorous physical activity (MVPA) with cardiometabolic risk in children. In addition, the moderating effects of weight status and MVPA were explored. SUBJECTS....../METHODS: Longitudinal study including 454 primary school children (mean age 10.3 years). Total volume and bouts (i.e. ≥10 min consecutive minutes) of MVPA and SB were assessed by accelerometry in Nov 2009/Jan 2010 (T1) and Aug/Oct 2010 (T2). Triglycerides, total cholesterol/HDL cholesterol ratio (TC:HDLC ratio......, with or without mutual adjustments between MVPA and SB. The moderating effects of weight status and MVPA (for SB only) were examined by adding interaction terms. RESULTS: Children engaged daily in about 60 min of total MVPA and 0-15 min/week in MVPA bouts. Mean total sedentary time was around 7 h/day with over 3...
University of Alaska 1997 Facilities Inventory.
Alaska Univ., Fairbanks. Statewide Office of Institutional Research.
This facilities inventory report presents a comprehensive listing of physical assets owned and operated by the University of Alaska and includes, for each asset, data on average age, weighted average age, gross square footage, original total project funding, and the asset's plant investment value adjusted to the current year. Facilities are listed…
Dempsey, William M.
1997-01-01
A Rochester Institute of Technology (New York) program costing model designed to reflect costs more accurately allocates indirect costs according to salaries and wages, modified total direct costs, square footage of space used, credit hours, and student and faculty full-time equivalents. It allows administrators to make relative value judgments…
KLE Translog production function and total factor productivity
Czech Academy of Sciences Publication Activity Database
Klacek, J.; Vošvrda, Miloslav; Schlosser, Š.
2007-01-01
Roč. 87, č. 4 (2007), s. 261-274 ISSN 0322-788X Institutional research plan: CEZ:AV0Z10750506 Keywords : total factor productivity * translog production function * aggregate production function * least squares method * ridge regression Subject RIV: AH - Economics
Role and significance of total phenols during rooting of Protea ...
African Journals Online (AJOL)
Reviewer
2011-10-03
Oct 3, 2011 ... fluctuations in total phenol concentration of different parts ... Rooting percentage, mean root dry mass and mean number of roots according to root length ... differences at P ≤ 0.05 based on chi-square; 2different letters in.
Total versus subtotal hysterectomy
DEFF Research Database (Denmark)
Gimbel, Helga; Zobbe, Vibeke; Andersen, Anna Birthe
2005-01-01
The aim of this study was to compare total and subtotal abdominal hysterectomy for benign indications, with regard to urinary incontinence, postoperative complications, quality of life (SF-36), constipation, prolapse, satisfaction with sexual life, and pelvic pain at 1-year postoperative. Eighty...... women chose total and 105 women chose subtotal abdominal hysterectomy. No significant differences were found between the 2 operation methods in any of the outcome measures at 12 months. Fourteen women (15%) from the subtotal abdominal hysterectomy group experienced vaginal bleeding and three women had...
Qualità totale e mobilità totale Total Quality and Total Mobility
Directory of Open Access Journals (Sweden)
Giuseppe Trieste
2010-05-01
Full Text Available FIABA ONLUS (Italian Fund for Elimination of Architectural Barriers was founded in 2000 with the aim of promoting a culture of equal opportunities and, above all, it has as its main goal to involve public and private institutions to create a really accessible and usable environment for everyone. Total accessibility, Total usability and Total mobility are key indicators to define quality of life within cities. A supportive environment that is free of architectural, cultural and psychological barriers allows everyone to live with ease and universality. In fact, people who access to goods and services in the urban context can use to their advantage time and space, so they can do their activities and can maintain relationships that are deemed significant for their social life. The main aim of urban accessibility is to raise the comfort of space for citizens, eliminating all barriers that discriminate people, and prevent from an equality of opportunity. “FIABA FUND - City of ... for the removal of architectural barriers” is an idea of FIABA that has already affected many regions of Italy as Lazio, Lombardy, Campania, Abruzzi and Calabria. It is a National project which provides for opening a bank account in the cities of referring, in which for the first time, all together, individuals and private and public institutions can make a donation to fund initiatives for the removal of architectural barriers within its own territory for a real and effective total accessibility. Last February the fund was launched in Rome with the aim of achieving a Capital without barriers and a Town European model of accessibility and usability. Urban mobility is a prerequisite to access to goods and services, and to organize activities related to daily life. FIABA promotes the concept of sustainable mobility for all, supported by the European Commission’s White Paper. We need a cultural change in management and organization of public means, which might focus on
Total variation superiorized conjugate gradient method for image reconstruction
Zibetti, Marcelo V. W.; Lin, Chuan; Herman, Gabor T.
2018-03-01
The conjugate gradient (CG) method is commonly used for the relatively-rapid solution of least squares problems. In image reconstruction, the problem can be ill-posed and also contaminated by noise; due to this, approaches such as regularization should be utilized. Total variation (TV) is a useful regularization penalty, frequently utilized in image reconstruction for generating images with sharp edges. When a non-quadratic norm is selected for regularization, as is the case for TV, then it is no longer possible to use CG. Non-linear CG is an alternative, but it does not share the efficiency that CG shows with least squares and methods such as fast iterative shrinkage-thresholding algorithms (FISTA) are preferred for problems with TV norm. A different approach to including prior information is superiorization. In this paper it is shown that the conjugate gradient method can be superiorized. Five different CG variants are proposed, including preconditioned CG. The CG methods superiorized by the total variation norm are presented and their performance in image reconstruction is demonstrated. It is illustrated that some of the proposed variants of the superiorized CG method can produce reconstructions of superior quality to those produced by FISTA and in less computational time, due to the speed of the original CG for least squares problems. In the Appendix we examine the behavior of one of the superiorized CG methods (we call it S-CG); one of its input parameters is a positive number ɛ. It is proved that, for any given ɛ that is greater than the half-squared-residual for the least squares solution, S-CG terminates in a finite number of steps with an output for which the half-squared-residual is less than or equal to ɛ. Importantly, it is also the case that the output will have a lower value of TV than what would be provided by unsuperiorized CG for the same value ɛ of the half-squared residual.
Suliman, Mohamed Abdalla Elhag
2016-12-19
This paper proposes a new approach to find the regularization parameter for linear least-squares discrete ill-posed problems. In the proposed approach, an artificial perturbation matrix with a bounded norm is forced into the discrete ill-posed model matrix. This perturbation is introduced to enhance the singular-value (SV) structure of the matrix and hence to provide a better solution. The proposed approach is derived to select the regularization parameter in a way that minimizes the mean-squared error (MSE) of the estimator. Numerical results demonstrate that the proposed approach outperforms a set of benchmark methods in most cases when applied to different scenarios of discrete ill-posed problems. Jointly, the proposed approach enjoys the lowest run-time and offers the highest level of robustness amongst all the tested methods.
Directory of Open Access Journals (Sweden)
Mardawia M Panrereng
2015-06-01
Full Text Available Dalam beberapa tahun terakhir, sistem komunikasi akustik bawah air banyak dikembangkan oleh beberapa peneliti. Besarnya tantangan yang dihadapi membuat para peneliti semakin tertarik untuk mengembangkan penelitian dibidang ini. Kanal bawah air merupakan media komunikasi yang sulit karena adanya attenuasi, absorption, dan multipath yang disebabkan oleh gerakan gelombang air setiap saat. Untuk perairan dangkal, multipath disebabkan adanya pantulan dari permukaan dan dasar laut. Kebutuhan pengiriman data cepat dengan bandwidth terbatas menjadikan Ortogonal Frequency Division Multiplexing (OFDM sebagai solusi untuk komunikasi transmisi tinggi dengan modulasi menggunakan Binary Phase-Shift Keying (BPSK. Estimasi kanal bertujuan untuk mengetahui karakteristik respon impuls kanal propagasi dengan mengirimkan pilot simbol. Pada estimasi kanal menggunakan metode Least Square (LS nilai Mean Square Error (MSE yang diperoleh cenderung lebih besar dari metode estimasi kanal menggunakan metode Minimum Mean Square (MMSE. Hasil kinerja estimasi kanal berdasarkan perhitungan Bit Error Rate (BER untuk estimasi kanal menggunakan metode LS dan metode MMSE tidak menunjukkan perbedaan yang signifikan yaitu berselisih satu SNR untuk setiap metode estimasi kanal yang digunakan.
International Nuclear Information System (INIS)
Ye, Zhiyong; Zhang, He; Zhang, Hongyu; Zhang, Hua; Lu, Guichen
2015-01-01
Highlights: •This paper introduces a non-conservative Lyapunov functional. •The achieved results impose non-conservative and can be widely used. •The conditions are easily checked by the Matlab LMI Tool Box. The desired state feedback controller can be well represented by the conditions. -- Abstract: This paper addresses the mean square exponential stabilization problem of stochastic bidirectional associative memory (BAM) neural networks with Markovian jumping parameters and time-varying delays. By establishing a proper Lyapunov–Krasovskii functional and combining with LMIs technique, several sufficient conditions are derived for ensuring exponential stabilization in the mean square sense of such stochastic BAM neural networks. In addition, the achieved results are not difficult to verify for determining the mean square exponential stabilization of delayed BAM neural networks with Markovian jumping parameters and impose less restrictive and less conservative than the ones in previous papers. Finally, numerical results are given to show the effectiveness and applicability of the achieved results
CSF total protein is a test to determine the amount of protein in your spinal fluid, also called cerebrospinal fluid (CSF). ... The normal protein range varies from lab to lab, but is typically about 15 to 60 milligrams per deciliter (mg/dL) ...
International Nuclear Information System (INIS)
Novack, D.H.; Kiley, J.P.
1987-01-01
The multitude of papers and conferences in recent years on the use of very large megavoltage radiation fields indicates an increased interest in total body, hemibody, and total nodal radiotherapy for various clinical situations. These include high dose total body irradiation (TBI) to destroy the bone marrow and leukemic cells and provide immunosuppression prior to a bone marrow transplant, high dose total lymphoid irradiation (TLI) prior to bone marrow transplantation in severe aplastic anemia, low dose TBI in the treatment of lymphocytic leukemias or lymphomas, and hemibody irradiation (HBI) in the treatment of advanced multiple myeloma. Although accurate provision of a specific dose and the desired degree of dose homogeneity are two of the physicist's major considerations for all radiotherapy techniques, these tasks are even more demanding for large field radiotherapy. Because most large field radiotherapy is done at an extended distance for complex patient geometries, basic dosimetry data measured at the standard distance (isocenter) must be verified or supplemented. This paper discusses some of the special dosimetric problems of large field radiotherapy, with specific examples given of the dosimetry of the TBI program for bone marrow transplant at the authors' hospital
DEFF Research Database (Denmark)
Munch, Anders V.
2016-01-01
The idea of design as an art made not only for the people, but also by the people is an old dream going back at least to William Morris. It is, however, reappearing vigoriously in many kinds of design activism and grows out of the visions of a Total Design of society. The ideas of participation b...
Total Quality Management Simplified.
Arias, Pam
1995-01-01
Maintains that Total Quality Management (TQM) is one method that helps to monitor and improve the quality of child care. Lists four steps for a child-care center to design and implement its own TQM program. Suggests that quality assurance in child-care settings is an ongoing process, and that TQM programs help in providing consistent, high-quality…
Total Quality Management Seminar.
Massachusetts Career Development Inst., Springfield.
This booklet is one of six texts from a workplace literacy curriculum designed to assist learners in facing the increased demands of the workplace. The booklet contains seven sections that cover the following topics: (1) meaning of total quality management (TQM); (2) the customer; (3) the organization's culture; (4) comparison of management…
International Nuclear Information System (INIS)
Carlos, P.
1985-01-01
Experimental methods using real photon beams for measurements of total photonuclear absorption cross section σ(Tot : E/sub γ/) are recalled. Most recent σ(Tot : E/sub γ/)results for complex nuclei and in the nucleon resonance region are presented
International Nuclear Information System (INIS)
2004-01-01
This annual report of the Group Total brings information and economic data on the following topics, for the year 2004: the corporate governance, the corporate social responsibility, the shareholder notebook, the management report, the activities, the upstream (exploration and production) and downstream (refining and marketing) operating, chemicals and other matters. (A.L.B.)
Total Water Management - Report
There is a growing need for urban water managers to take a more holistic view of their water resource systems as population growth, urbanization, and current operations put different stresses on the environment and urban infrastructure. Total Water Management (TWM) is an approac...
Nonnegative least-squares image deblurring: improved gradient projection approaches
Benvenuto, F.; Zanella, R.; Zanni, L.; Bertero, M.
2010-02-01
The least-squares approach to image deblurring leads to an ill-posed problem. The addition of the nonnegativity constraint, when appropriate, does not provide regularization, even if, as far as we know, a thorough investigation of the ill-posedness of the resulting constrained least-squares problem has still to be done. Iterative methods, converging to nonnegative least-squares solutions, have been proposed. Some of them have the 'semi-convergence' property, i.e. early stopping of the iteration provides 'regularized' solutions. In this paper we consider two of these methods: the projected Landweber (PL) method and the iterative image space reconstruction algorithm (ISRA). Even if they work well in many instances, they are not frequently used in practice because, in general, they require a large number of iterations before providing a sensible solution. Therefore, the main purpose of this paper is to refresh these methods by increasing their efficiency. Starting from the remark that PL and ISRA require only the computation of the gradient of the functional, we propose the application to these algorithms of special acceleration techniques that have been recently developed in the area of the gradient methods. In particular, we propose the application of efficient step-length selection rules and line-search strategies. Moreover, remarking that ISRA is a scaled gradient algorithm, we evaluate its behaviour in comparison with a recent scaled gradient projection (SGP) method for image deblurring. Numerical experiments demonstrate that the accelerated methods still exhibit the semi-convergence property, with a considerable gain both in the number of iterations and in the computational time; in particular, SGP appears definitely the most efficient one.
International Nuclear Information System (INIS)
2003-01-01
This document presents the 2003 results of Total Group: consolidated account, special items, number of shares, market environment, 4. quarter 2003 results, full year 2003 results, upstream (key figures, proved reserves), downstream key figures, chemicals key figures, parent company accounts and proposed dividends, 2004 sensitivities, summary and outlook, operating information by segment for the 4. quarter and full year 2003: upstream (combined liquids and gas production by region, liquids production by region, gas production by region), downstream (refinery throughput by region, refined product sales by region, chemicals), impact of allocating contribution of Cepsa to net operating income by business segment: equity in income (loss) and affiliates and other items, Total financial statements: consolidated statement of income, consolidated balance sheet (assets, liabilities and shareholder's equity), consolidated statements of cash flows, business segments information. (J.S.)
Directory of Open Access Journals (Sweden)
Anca ȘERBAN
2013-06-01
Full Text Available The purpose of this paper is to present the evolution of the Balanced Scorecard from a measurement instrument to a strategic performance management tool and to highlight the advantages of implementing the Total Performance Scorecard, especially for Human Resource Management. The study has been accomplished using the methodology of bibliographic study and various secondary sources. Implementing the classical Balanced Scorecard indicated over the years, repeatedly failure. It can be indicated that the crucial level is determined by the learning and growth perspective. It has been developed from a human perspective, which focused on staff satisfaction, innovation perspective with focus on future developments. Integrating the Total Performance Scorecard in an overall framework assures the company’s success, by keeping track of the individual goals, the company’s objectives and strategic directions. Like this, individual identity can be linked to corporate brand, individual aspirations to business goals and individual learning objectives to needed organizational capabilities.
Totally parallel multilevel algorithms
Frederickson, Paul O.
1988-01-01
Four totally parallel algorithms for the solution of a sparse linear system have common characteristics which become quite apparent when they are implemented on a highly parallel hypercube such as the CM2. These four algorithms are Parallel Superconvergent Multigrid (PSMG) of Frederickson and McBryan, Robust Multigrid (RMG) of Hackbusch, the FFT based Spectral Algorithm, and Parallel Cyclic Reduction. In fact, all four can be formulated as particular cases of the same totally parallel multilevel algorithm, which are referred to as TPMA. In certain cases the spectral radius of TPMA is zero, and it is recognized to be a direct algorithm. In many other cases the spectral radius, although not zero, is small enough that a single iteration per timestep keeps the local error within the required tolerance.
Quantum infinite square well with an oscillating wall
International Nuclear Information System (INIS)
Glasser, M.L.; Mateo, J.; Negro, J.; Nieto, L.M.
2009-01-01
A linear matrix equation is considered for determining the time dependent wave function for a particle in a one-dimensional infinite square well having one moving wall. By a truncation approximation, whose validity is checked in the exactly solvable case of a linearly contracting wall, we examine the cases of a simple harmonically oscillating wall and a non-harmonically oscillating wall for which the defining parameters can be varied. For the latter case, we examine in closer detail the dependence on the frequency changes, and we find three regimes: an adiabatic behabiour for low frequencies, a periodic one for high frequencies, and a chaotic behaviour for an intermediate range of frequencies.
Identifying Dirac cones in carbon allotropes with square symmetry
Energy Technology Data Exchange (ETDEWEB)
Wang, Jinying [College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Huang, Huaqing; Duan, Wenhui [Department of Physics, Tsinghua University, Beijing 100084 (China); Liu, Zhirong, E-mail: LiuZhiRong@pku.edu.cn [College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); State Key Laboratory for Structural Chemistry of Unstable and Stable Species and Beijing National Laboratory for Molecular Sciences (BNLMS), Peking University, Beijing 100871 (China)
2013-11-14
A theoretical study is conducted to search for Dirac cones in two-dimensional carbon allotropes with square symmetry. By enumerating the carbon atoms in a unit cell up to 12, an allotrope with octatomic rings is recognized to possess Dirac cones under a simple tight-binding approach. The obtained Dirac cones are accompanied by flat bands at the Fermi level, and the resulting massless Dirac-Weyl fermions are chiral particles with a pseudospin of S = 1, rather than the conventional S = 1/2 of graphene. The spin-1 Dirac cones are also predicted to exist in hexagonal graphene antidot lattices.
Renormalization group theory of phase transitions in square Ising systems
International Nuclear Information System (INIS)
Nienhuis, B.
1978-01-01
Some renormalization group calculations are presented on a number of phase transitions in a square Ising model, both second and first order. Of these transitions critical exponents are calculated, the amplitudes of the power law divergences and the locus of the transition. In some cases attention is paid to the thermodynamic functions also far from the critical point. Universality and scaling are discussed and the renormalization group theory is reviewed. It is shown how a renormalization transformation, which relates two similar systems with different macroscopic dimensions, can be constructed, and how some critical properties of the system follow from this transformation. Several numerical and analytical applications are presented. (Auth.)
Pattern formation in two-dimensional square-shoulder systems
International Nuclear Information System (INIS)
Fornleitner, Julia; Kahl, Gerhard
2010-01-01
Using a highly efficient and reliable optimization tool that is based on ideas of genetic algorithms, we have systematically studied the pattern formation of the two-dimensional square-shoulder system. An overwhelming wealth of complex ordered equilibrium structures emerge from this investigation as we vary the shoulder width. With increasing pressure three structural archetypes could be identified: cluster lattices, where clusters of particles occupy the sites of distorted hexagonal lattices, lane formation, and compact particle arrangements with high coordination numbers. The internal complexity of these structures increases with increasing shoulder width.
Pattern formation in two-dimensional square-shoulder systems
Energy Technology Data Exchange (ETDEWEB)
Fornleitner, Julia [Institut fuer Festkoerperforschung, Forschungsszentrum Juelich, D-52425 Juelich (Germany); Kahl, Gerhard, E-mail: fornleitner@cmt.tuwien.ac.a [Institut fuer Theoretische Physik and Centre for Computational Materials Science (CMS), Technische Universitaet Wien, Wiedner Hauptstrasse 8-10, A-1040 Wien (Austria)
2010-03-17
Using a highly efficient and reliable optimization tool that is based on ideas of genetic algorithms, we have systematically studied the pattern formation of the two-dimensional square-shoulder system. An overwhelming wealth of complex ordered equilibrium structures emerge from this investigation as we vary the shoulder width. With increasing pressure three structural archetypes could be identified: cluster lattices, where clusters of particles occupy the sites of distorted hexagonal lattices, lane formation, and compact particle arrangements with high coordination numbers. The internal complexity of these structures increases with increasing shoulder width.
Application of square-root filtering for spacecraft attitude control
Sorensen, J. A.; Schmidt, S. F.; Goka, T.
1978-01-01
Suitable digital algorithms are developed and tested for providing on-board precision attitude estimation and pointing control for potential use in the Landsat-D spacecraft. These algorithms provide pointing accuracy of better than 0.01 deg. To obtain necessary precision with efficient software, a six state-variable square-root Kalman filter combines two star tracker measurements to update attitude estimates obtained from processing three gyro outputs. The validity of the estimation and control algorithms are established, and the sensitivity of their performance to various error sources and software parameters are investigated by detailed digital simulation. Spacecraft computer memory, cycle time, and accuracy requirements are estimated.
Handbook of Partial Least Squares Concepts, Methods and Applications
Vinzi, Vincenzo Esposito; Henseler, Jörg
2010-01-01
This handbook provides a comprehensive overview of Partial Least Squares (PLS) methods with specific reference to their use in marketing and with a discussion of the directions of current research and perspectives. It covers the broad area of PLS methods, from regression to structural equation modeling applications, software and interpretation of results. The handbook serves both as an introduction for those without prior knowledge of PLS and as a comprehensive reference for researchers and practitioners interested in the most recent advances in PLS methodology.
Regularization Techniques for Linear Least-Squares Problems
Suliman, Mohamed
2016-04-01
Linear estimation is a fundamental branch of signal processing that deals with estimating the values of parameters from a corrupted measured data. Throughout the years, several optimization criteria have been used to achieve this task. The most astonishing attempt among theses is the linear least-squares. Although this criterion enjoyed a wide popularity in many areas due to its attractive properties, it appeared to suffer from some shortcomings. Alternative optimization criteria, as a result, have been proposed. These new criteria allowed, in one way or another, the incorporation of further prior information to the desired problem. Among theses alternative criteria is the regularized least-squares (RLS). In this thesis, we propose two new algorithms to find the regularization parameter for linear least-squares problems. In the constrained perturbation regularization algorithm (COPRA) for random matrices and COPRA for linear discrete ill-posed problems, an artificial perturbation matrix with a bounded norm is forced into the model matrix. This perturbation is introduced to enhance the singular value structure of the matrix. As a result, the new modified model is expected to provide a better stabilize substantial solution when used to estimate the original signal through minimizing the worst-case residual error function. Unlike many other regularization algorithms that go in search of minimizing the estimated data error, the two new proposed algorithms are developed mainly to select the artifcial perturbation bound and the regularization parameter in a way that approximately minimizes the mean-squared error (MSE) between the original signal and its estimate under various conditions. The first proposed COPRA method is developed mainly to estimate the regularization parameter when the measurement matrix is complex Gaussian, with centered unit variance (standard), and independent and identically distributed (i.i.d.) entries. Furthermore, the second proposed COPRA
Positive Scattering Cross Sections using Constrained Least Squares
International Nuclear Information System (INIS)
Dahl, J.A.; Ganapol, B.D.; Morel, J.E.
1999-01-01
A method which creates a positive Legendre expansion from truncated Legendre cross section libraries is presented. The cross section moments of order two and greater are modified by a constrained least squares algorithm, subject to the constraints that the zeroth and first moments remain constant, and that the standard discrete ordinate scattering matrix is positive. A method using the maximum entropy representation of the cross section which reduces the error of these modified moments is also presented. These methods are implemented in PARTISN, and numerical results from a transport calculation using highly anisotropic scattering cross sections with the exponential discontinuous spatial scheme is presented
Enhancing Pseudo-Telepathy in the Magic Square Game
Pawela, Łukasz; Gawron, Piotr; Puchała, Zbigniew; Sładkowski, Jan
2013-01-01
We study the possibility of reversing an action of a quantum channel. Our principal objective is to find a specific channel that reverses as accurately as possible an action of a given quantum channel. To achieve this goal we use semidefinite programming. We show the benefits of our method using the quantum pseudo-telepathy Magic Square game with noise. Our strategy is to move the pseudo-telepathy region to higher noise values. We show that it is possible to reverse the action of a noise channel using semidefinite programming. PMID:23762246
Single Directional SMO Algorithm for Least Squares Support Vector Machines
Directory of Open Access Journals (Sweden)
Xigao Shao
2013-01-01
Full Text Available Working set selection is a major step in decomposition methods for training least squares support vector machines (LS-SVMs. In this paper, a new technique for the selection of working set in sequential minimal optimization- (SMO- type decomposition methods is proposed. By the new method, we can select a single direction to achieve the convergence of the optimality condition. A simple asymptotic convergence proof for the new algorithm is given. Experimental comparisons demonstrate that the classification accuracy of the new method is not largely different from the existing methods, but the training speed is faster than existing ones.
Square-lattice random Potts model: criticality and pitchfork bifurcation
International Nuclear Information System (INIS)
Costa, U.M.S.; Tsallis, C.
1983-01-01
Within a real space renormalization group framework based on self-dual clusters, the criticality of the quenched bond-mixed q-state Potts ferromagnet on square lattice is discussed. On qualitative grounds it is exhibited that the crossover from the pure fixed point to the random one occurs, while q increases, through a pitchfork bifurcation; the relationship with Harris criterion is analyzed. On quantitative grounds high precision numerical values are presented for the critical temperatures corresponding to various concentrations of the coupling constants J 1 and J 2 , and various ratios J 1 /J 2 . The pure, random and crossover critical exponents are discussed as well. (Author) [pt
One-dimensional scattering problem for inverse square potential
International Nuclear Information System (INIS)
Mineev, V.S.
1990-01-01
Analytical continuation of the solution for the Schroedinger equation of inverse square potential, together with the modified method for variation of constants makes it possible to construct admittable self-adjoint extensions and to completely analyze the respective scattering problem along the entire line. In this case, the current density conservation and the wave function continuity when passing through the singular point x=0 require, that a 8-shaped induced potential should be introduced in the Schroedinger equation. The relevant calculations have shown that the potential x -2 can be either absolutely penetrable or absolutely impenetrable. 16 refs
Optimization of sequential decisions by least squares Monte Carlo method
DEFF Research Database (Denmark)
Nishijima, Kazuyoshi; Anders, Annett
change adaptation measures, and evacuation of people and assets in the face of an emerging natural hazard event. Focusing on the last example, an efficient solution scheme is proposed by Anders and Nishijima (2011). The proposed solution scheme takes basis in the least squares Monte Carlo method, which...... is proposed by Longstaff and Schwartz (2001) for pricing of American options. The present paper formulates the decision problem in a more general manner and explains how the solution scheme proposed by Anders and Nishijima (2011) is implemented for the optimization of the formulated decision problem...
Regaining the Square of Opposition in Formal Ontology Development
DEFF Research Database (Denmark)
Nilsson, Jørgen Fischer
2014-01-01
be held simply in the case that "all P are Q" does not hold. These default rules are routinely adopted in ontology development without mentioning. Appealing to these conventions, the 4 sentence forms in the square are effectively made at disposal. We discuss a first order metalogical formalization...... of the 4 sentence forms with classes reified as individual constants elucidating the logical relationships between the sentence forms. Our formalization appeals to non-provability. Non-provability incurs non-monotonicity, implying that extension of an ontology with additional subclass relationships may...
Czech Academy of Sciences Publication Activity Database
Bonacina, I.; Galesi, N.; Thapen, Neil
2016-01-01
Roč. 45, č. 5 (2016), s. 1894-1909 ISSN 0097-5397 R&D Projects: GA ČR GBP202/12/G061 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : total space * resolution random CNFs * proof complexity Subject RIV: BA - General Mathematics Impact factor: 1.433, year: 2016 http://epubs.siam.org/doi/10.1137/15M1023269
International Nuclear Information System (INIS)
Choy, J.H.
1979-06-01
A benchmark of the TOTAL data base management system as applied to the Mirror Fusion Test Facility (MFTF) data base was implemented and run in February and March of 1979. The benchmark was run on an Interdata 8/32 and involved the following tasks: (1) data base design, (2) data base generation, (3) data base load, and (4) develop and implement programs to simulate MFTF usage of the data base
International Nuclear Information System (INIS)
2006-01-01
This annual report presents the activities and results of TOTAL S.A., french society on oil and gas. It deals with statistics, the managers, key information on financial data and risk factors, information on the Company, unresolved Staff Comments, employees, major Shareholders, consolidated statements, markets, security, financial risks, defaults dividend arrearages and delinquencies, controls and procedures, code of ethics and financial statements. (A.L.B.)
International Nuclear Information System (INIS)
Rubio, B.; Gelletly, W.
2007-01-01
The problem of determining the distribution of beta decay strength (B(GT)) as a function of excitation energy in the daughter nucleus is discussed. Total Absorption Spectroscopy is shown to provide a way of determining the B(GT) precisely. A brief history of such measurements and a discussion of the advantages and disadvantages of this technique, is followed by examples of two recent studies using the technique. (authors)
Sobredentadura total superior implantosoportada
Directory of Open Access Journals (Sweden)
Luis Orlando Rodríguez García
2010-06-01
Full Text Available Se presenta un caso de un paciente desdentado total superior, rehabilitado en la consulta de implantología de la Clínica "Pedro Ortiz" del municipio Habana del Este en Ciudad de La Habana, Cuba, en el año 2009, mediante prótesis sobre implantes osteointegrados, técnica que se ha incorporado a la práctica estomatológica en Cuba como alternativa al tratamiento convencional en los pacientes desdentados totales. Se siguió un protocolo que comprendió una fase quirúrgica, procedimiento con o sin realización de colgajo y carga precoz o inmediata. Se presenta un paciente masculino de 56 años de edad, que acudió a la consulta multidisciplinaria, preocupado, porque se le habían elaborado tres prótesis en los últimos dos años y ninguna reunía los requisitos de retención que él necesitaba para sentirse seguro y cómodo con las mismas. El resultado final fue la satisfacción total del paciente, con el mejoramiento de la calidad estética y funcional.
Block Least Mean Squares Algorithm over Distributed Wireless Sensor Network
Directory of Open Access Journals (Sweden)
T. Panigrahi
2012-01-01
Full Text Available In a distributed parameter estimation problem, during each sampling instant, a typical sensor node communicates its estimate either by the diffusion algorithm or by the incremental algorithm. Both these conventional distributed algorithms involve significant communication overheads and, consequently, defeat the basic purpose of wireless sensor networks. In the present paper, we therefore propose two new distributed algorithms, namely, block diffusion least mean square (BDLMS and block incremental least mean square (BILMS by extending the concept of block adaptive filtering techniques to the distributed adaptation scenario. The performance analysis of the proposed BDLMS and BILMS algorithms has been carried out and found to have similar performances to those offered by conventional diffusion LMS and incremental LMS algorithms, respectively. The convergence analyses of the proposed algorithms obtained from the simulation study are also found to be in agreement with the theoretical analysis. The remarkable and interesting aspect of the proposed block-based algorithms is that their communication overheads per node and latencies are less than those of the conventional algorithms by a factor as high as the block size used in the algorithms.
Quantitative determination of glycyrrhizinic acid by square-wave
Directory of Open Access Journals (Sweden)
Aneta Dimitrovska
2003-06-01
Full Text Available Novel adsorptive stripping square-wave voltammetric method as well as a new high-pressure liquid chromatographic method for direct determination of glycyrrhizinic acid in dosage pharmaceutical preparation, used against virus infections, have been developed. Glycyrrhizinic acid is an electrochemically active compound, which undergoes irreversible reduction on a mercury electrode surface in an aqueous medium. Its redox properties were studied thoroughly by means of square-wave voltammetry, as one of the most advanced electroanalytical technique. The voltammetric response depends mainly on the pH of the medium, composition of the supporting electrolyte, as well as the parameters of the excitement signal. It was also observed that the voltammetric properties strongly depend on the accumulation time and potential, revealing significant adsorption of glycyrrhizinic acid onto the mercury electrode surface. Upon this feature, an adsorptive stripping voltammetric method for quantitative determination of glycyrrhizinic acid was developed. A simple, sensitive and precise reversed phase HPLC method with photodiode array UV detection has also been developed, mainly for comparison and conformation of the results obtained with the voltammetric method.
An Incremental Weighted Least Squares Approach to Surface Lights Fields
Coombe, Greg; Lastra, Anselmo
An Image-Based Rendering (IBR) approach to appearance modelling enables the capture of a wide variety of real physical surfaces with complex reflectance behaviour. The challenges with this approach are handling the large amount of data, rendering the data efficiently, and previewing the model as it is being constructed. In this paper, we introduce the Incremental Weighted Least Squares approach to the representation and rendering of spatially and directionally varying illumination. Each surface patch consists of a set of Weighted Least Squares (WLS) node centers, which are low-degree polynomial representations of the anisotropic exitant radiance. During rendering, the representations are combined in a non-linear fashion to generate a full reconstruction of the exitant radiance. The rendering algorithm is fast, efficient, and implemented entirely on the GPU. The construction algorithm is incremental, which means that images are processed as they arrive instead of in the traditional batch fashion. This human-in-the-loop process enables the user to preview the model as it is being constructed and to adapt to over-sampling and under-sampling of the surface appearance.
Between Community Spaces: Squares of Minor Centers of Calabria
Directory of Open Access Journals (Sweden)
Mauro Francini
2017-08-01
Full Text Available The theme of open “community spaces” in recent years has to the development of important interdisciplinary issues. Nevertheless, the reading of smaller towns, in urbanistic, historical-anthropological and geographical terms appears less extended, considering the declination of public spaces as "squares." Starting from this declension we would like to introduce the first results of a research. The research had the aim of (reinterpreting the particular characteristics of these areas in specific areas such as small towns, using the region of Calabria for the case of analytic application. These communities have diverse and stratified living cultures, altered by settlement processes that have triggered two different types of urban contexts. The former often lead either to urban areas in depopulated decay or, in contrast, in places of memories: empty containers of relationships, sterile and crystallized museum objects, reduced to scenarios on which passing groups of visitors move necessarily from those realities. The latter often encircle primitive nuclei, asphyxiating them, or characterizing the so-called "dual" or "satellites" towns, completely detached from the original urban center in which all public functions are decentralized. The applied methodology is based on the reading of the historical-functional evolution of squares by the identification of codified compositional criteria. Through this research we seek to verify how urban planning, in synergy with other disciplines, can define processes of regeneration aimed at restoring the meaning of "center", and thus of an urban-community reference center.
Square tracking sensor for autonomous helicopter hover stabilization
Oertel, Carl-Henrik
1995-06-01
Sensors for synthetic vision are needed to extend the mission profiles of helicopters. A special task for various applications is the autonomous position hold of a helicopter above a ground fixed or moving target. As a proof of concept for a general synthetic vision solution a restricted machine vision system, which is capable of locating and tracking a special target, was developed by the Institute of Flight Mechanics of Deutsche Forschungsanstalt fur Luft- und Raumfahrt e.V. (i.e., German Aerospace Research Establishment). This sensor, which is specialized to detect and track a square, was integrated in the fly-by-wire helicopter ATTHeS (i.e., Advanced Technology Testing Helicopter System). An existing model following controller for the forward flight condition was adapted for the hover and low speed requirements of the flight vehicle. The special target, a black square with a length of one meter, was mounted on top of a car. Flight tests demonstrated the automatic stabilization of the helicopter above the moving car by synthetic vision.
Weighted least-squares criteria for electrical impedance tomography
International Nuclear Information System (INIS)
Kallman, J.S.; Berryman, J.G.
1992-01-01
Methods are developed for design of electrical impedance tomographic reconstruction algorithms with specified properties. Assuming a starting model with constant conductivity or some other specified background distribution, an algorithm with the following properties is found: (1) the optimum constant for the starting model is determined automatically; (2) the weighted least-squares error between the predicted and measured power dissipation data is as small as possible; (3) the variance of the reconstructed conductivity from the starting model is minimized; (4) potential distributions with the largest volume integral of gradient squared have the least influence on the reconstructed conductivity, and therefore distributions most likely to be corrupted by contact impedance effects are deemphasized; (5) cells that dissipate the most power during the current injection tests tend to deviate least from the background value. The resulting algorithm maps the reconstruction problem into a vector space where the contribution to the inversion from the background conductivity remains invariant, while the optimum contributions in orthogonal directions are found. For a starting model with nonconstant conductivity, the reconstruction algorithm has analogous properties
Percolation of overlapping squares or cubes on a lattice
International Nuclear Information System (INIS)
Koza, Zbigniew; Kondrat, Grzegorz; Suszczyński, Karol
2014-01-01
Porous media are often modeled as systems of overlapping obstacles, which leads to the problem of two percolation thresholds in such systems, one for the porous matrix and the other for the void space. Here we investigate these percolation thresholds in the model of overlapping squares or cubes of linear size k > 1 randomly distributed on a regular lattice. We find that the percolation threshold of obstacles is a nonmonotonic function of k, whereas the percolation threshold of the void space is well approximated by a function linear in 1/k. We propose a generalization of the excluded volume approximation to discrete systems and use it to investigate the transition between continuous and discrete percolation, finding a remarkable agreement between the theory and numerical results. We argue that the continuous percolation threshold of aligned squares on a plane is the same for the solid and void phases and estimate the continuous percolation threshold of the void space around aligned cubes in a 3D space as 0.036(1). We also discuss the connection of the model to the standard site percolation with complex neighborhood. (paper)
Plane-wave least-squares reverse-time migration
Dai, Wei
2013-06-03
A plane-wave least-squares reverse-time migration (LSRTM) is formulated with a new parameterization, where the migration image of each shot gather is updated separately and an ensemble of prestack images is produced along with common image gathers. The merits of plane-wave prestack LSRTM are the following: (1) plane-wave prestack LSRTM can sometimes offer stable convergence even when the migration velocity has bulk errors of up to 5%; (2) to significantly reduce computation cost, linear phase-shift encoding is applied to hundreds of shot gathers to produce dozens of plane waves. Unlike phase-shift encoding with random time shifts applied to each shot gather, plane-wave encoding can be effectively applied to data with a marine streamer geometry. (3) Plane-wave prestack LSRTM can provide higher-quality images than standard reverse-time migration. Numerical tests on the Marmousi2 model and a marine field data set are performed to illustrate the benefits of plane-wave LSRTM. Empirical results show that LSRTM in the plane-wave domain, compared to standard reversetime migration, produces images efficiently with fewer artifacts and better spatial resolution. Moreover, the prestack image ensemble accommodates more unknowns to makes it more robust than conventional least-squares migration in the presence of migration velocity errors. © 2013 Society of Exploration Geophysicists.
Feature extraction through least squares fit to a simple model
International Nuclear Information System (INIS)
Demuth, H.B.
1976-01-01
The Oak Ridge National Laboratory (ORNL) presented the Los Alamos Scientific Laboratory (LASL) with 18 radiographs of fuel rod test bundles. The problem is to estimate the thickness of the gap between some cylindrical rods and a flat wall surface. The edges of the gaps are poorly defined due to finite source size, x-ray scatter, parallax, film grain noise, and other degrading effects. The radiographs were scanned and the scan-line data were averaged to reduce noise and to convert the problem to one dimension. A model of the ideal gap, convolved with an appropriate point-spread function, was fit to the averaged data with a least squares program; and the gap width was determined from the final fitted-model parameters. The least squares routine did converge and the gaps obtained are of reasonable size. The method is remarkably insensitive to noise. This report describes the problem, the techniques used to solve it, and the results and conclusions. Suggestions for future work are also given
Making the most out of least-squares migration
Huang, Yunsong
2014-09-01
Standard migration images can suffer from (1) migration artifacts caused by an undersampled acquisition geometry, (2) poor resolution resulting from a limited recording aperture, (3) ringing artifacts caused by ripples in the source wavelet, and (4) weak amplitudes resulting from geometric spreading, attenuation, and defocusing. These problems can be remedied in part by least-squares migration (LSM), also known as linearized seismic inversion or migration deconvolution (MD), which aims to linearly invert seismic data for the reflectivity distribution. Given a sufficiently accurate migration velocity model, LSM can mitigate many of the above problems and can produce more resolved migration images, sometimes with more than twice the spatial resolution of standard migration. However, LSM faces two challenges: The computational cost can be an order of magnitude higher than that of standard migration, and the resulting image quality can fail to improve for migration velocity errors of about 5% or more. It is possible to obtain the most from least-squares migration by reducing the cost and velocity sensitivity of LSM.
Making the most out of the least (squares migration)
Dutta, Gaurav
2014-08-05
Standard migration images can suffer from migration artifacts due to 1) poor source-receiver sampling, 2) weak amplitudes caused by geometric spreading, 3) attenuation, 4) defocusing, 5) poor resolution due to limited source-receiver aperture, and 6) ringiness caused by a ringy source wavelet. To partly remedy these problems, least-squares migration (LSM), also known as linearized seismic inversion or migration deconvolution (MD), proposes to linearly invert seismic data for the reflectivity distribution. If the migration velocity model is sufficiently accurate, then LSM can mitigate many of the above problems and lead to a more resolved migration image, sometimes with twice the spatial resolution. However, there are two problems with LSM: the cost can be an order of magnitude more than standard migration and the quality of the LSM image is no better than the standard image for velocity errors of 5% or more. We now show how to get the most from least-squares migration by reducing the cost and velocity sensitivity of LSM.
Robust regularized least-squares beamforming approach to signal estimation
Suliman, Mohamed Abdalla Elhag
2017-05-12
In this paper, we address the problem of robust adaptive beamforming of signals received by a linear array. The challenge associated with the beamforming problem is twofold. Firstly, the process requires the inversion of the usually ill-conditioned covariance matrix of the received signals. Secondly, the steering vector pertaining to the direction of arrival of the signal of interest is not known precisely. To tackle these two challenges, the standard capon beamformer is manipulated to a form where the beamformer output is obtained as a scaled version of the inner product of two vectors. The two vectors are linearly related to the steering vector and the received signal snapshot, respectively. The linear operator, in both cases, is the square root of the covariance matrix. A regularized least-squares (RLS) approach is proposed to estimate these two vectors and to provide robustness without exploiting prior information. Simulation results show that the RLS beamformer using the proposed regularization algorithm outperforms state-of-the-art beamforming algorithms, as well as another RLS beamformers using a standard regularization approaches.
Condensation in a Square Minichannel: Application of the VOF Method
Bortolin, V; Del Col, Davide
2014-01-01
A number of steady-state numerical simulations of condensation of R134a at mass fluxes of 400 kg m−2 s−1 and 800 kg m−2 s−1 inside a 1-mm square cross section minichannel are proposed here and compared against simulations in a circular cross section channel with the same hydraulic diameter. The volume of fluid (VOF) method is used to track the vapor–liquid interface, and the effects of interfacial shear stress, surface tension, and gravity are taken into account. A uniform wall temperature is fixed as a boundary condition. At both mass velocities the liquid film and the vapor core are treated as turbulent; a low-Re form of the SST k-ω model has been used for the modeling of turbulence through both the liquid and vapor phases. Numerical simulations are validated against experimental data. The influence of the surface tension on the shape of the vapor–liquid interface may provide some heat transfer enhancement in a square cross section minichannel, but this depends on the mass flux and it may be no...
BRGLM, Interactive Linear Regression Analysis by Least Square Fit
International Nuclear Information System (INIS)
Ringland, J.T.; Bohrer, R.E.; Sherman, M.E.
1985-01-01
1 - Description of program or function: BRGLM is an interactive program written to fit general linear regression models by least squares and to provide a variety of statistical diagnostic information about the fit. Stepwise and all-subsets regression can be carried out also. There are facilities for interactive data management (e.g. setting missing value flags, data transformations) and tools for constructing design matrices for the more commonly-used models such as factorials, cubic Splines, and auto-regressions. 2 - Method of solution: The least squares computations are based on the orthogonal (QR) decomposition of the design matrix obtained using the modified Gram-Schmidt algorithm. 3 - Restrictions on the complexity of the problem: The current release of BRGLM allows maxima of 1000 observations, 99 variables, and 3000 words of main memory workspace. For a problem with N observations and P variables, the number of words of main memory storage required is MAX(N*(P+6), N*P+P*P+3*N, and 3*P*P+6*N). Any linear model may be fit although the in-memory workspace will have to be increased for larger problems
Dufour and Soret Effects on Square Porous Annulus
Directory of Open Access Journals (Sweden)
N. Nik-Ghazali
2014-04-01
Full Text Available A study on heat and mass transfer behaviour on porous medium embedded in a square annulus is conducted. The inner surface wall is considered to have a cool temperature Tc while the outer surface is exposed to a hot temperature Th. Finite element method (FEM is used to solve the governing partial differential equations. The results present the influences of the Dufour and Soret effects on the heat and mass transfer of a square annulus. The effects of various physical parameters on the temperature and concentration profiles together with the local Nusselt and Sherwood numbers are presented graphically. It is found that when Dufour parameter is increased, Nusselt number increases. Dufour effect has more influences on velocity profile, while it has no significant effect on the concentration and can be deemed negligible. It is observed that the local Nusselt number is highest at the bottom wall for low values of Dufour parameter; however, the top wall Nusselt number is highest for higher values of Dufour parameter. Soret effect tends to make more significant contribution to the concentration profile than Dufour effect.
Thermodynamic properties of magnetic strings on a square lattice
Mol, Lucas; Oliveira, Denis Da Mata; Bachmann, Michael
2015-03-01
In the last years, spin ice systems have increasingly attracted attention by the scientific community, mainly due to the appearance of collective excitations that behave as magnetic monopole like particles. In these systems, geometrical frustration induces the appearance of degenerated ground states characterized by a local energy minimization rule, the ice rule. Violations of this rule were shown to behave like magnetic monopoles connected by a string of dipoles that carries the magnetic flux from one monopole to the other. In order to obtain a deeper knowledge about the behavior of these excitations we study the thermodynamics of a kind of magnetic polymer formed by a chain of magnetic dipoles in a square lattice. This system is expected to capture the main properties of monopole-string excitations in the artificial square spin ice. It has been found recently that in this geometry the monopoles are confined, but the effective string tension is reduced by entropic effects. To obtain the thermodynamic properties of the strings we have exactly enumerated all possible string configurations of a given length and used standard statistical mechanics analysis to calculate thermodynamic quantities. We show that the low-temperature behavior is governed by strings that satisfy ice rules. Financial support from FAPEMIG and CNPq (Brazilian agencies) are gratefully acknowledged.
Efficient Model Selection for Sparse Least-Square SVMs
Directory of Open Access Journals (Sweden)
Xiao-Lei Xia
2013-01-01
Full Text Available The Forward Least-Squares Approximation (FLSA SVM is a newly-emerged Least-Square SVM (LS-SVM whose solution is extremely sparse. The algorithm uses the number of support vectors as the regularization parameter and ensures the linear independency of the support vectors which span the solution. This paper proposed a variant of the FLSA-SVM, namely, Reduced FLSA-SVM which is of reduced computational complexity and memory requirements. The strategy of “contexts inheritance” is introduced to improve the efficiency of tuning the regularization parameter for both the FLSA-SVM and the RFLSA-SVM algorithms. Experimental results on benchmark datasets showed that, compared to the SVM and a number of its variants, the RFLSA-SVM solutions contain a reduced number of support vectors, while maintaining competitive generalization abilities. With respect to the time cost for tuning of the regularize parameter, the RFLSA-SVM algorithm was empirically demonstrated fastest compared to FLSA-SVM, the LS-SVM, and the SVM algorithms.
Flow past two tandem square cylinders vibrating transversely in phase
International Nuclear Information System (INIS)
Mithun, M G; Tiwari, Shaligram
2014-01-01
Numerical investigations have been carried out to study the wake characteristics of flow past two tandem square cylinders vibrating in phase. Both the cylinders vibrate in a transverse direction, i.e., perpendicular to the incoming flow with the same frequency and amplitude. The frequency of vibration of the cylinders and the inter-cylinder spacing are varied for fixed values of the Reynolds number (Re = 100) and the amplitude ratio (A/D = 0.4). The synchronous or lock-in regime for the oscillatory wake of the vibrating cylinders has been identified by varying the frequency of the vibration from f e = 0.4 f 0 to 1.6 f 0 (f 0 being the frequency of vortex shedding behind a stationary square cylinder). The characteristics of lift and drag and the mechanism of vortex shedding are studied by varying the excitation frequency within the lock-in range for each value of inter-cylinder spacing. The complex interaction of flow between the cylinders gives rise to a variety of characteristically different shedding patterns in their wake. For values of inter-cylinder spacing equal to 2D and 3D, periodic, as well as quasi-periodic, lock-in behaviors are observed in the synchronous range. (paper)
Total Synthesis of Hyperforin.
Ting, Chi P; Maimone, Thomas J
2015-08-26
A 10-step total synthesis of the polycyclic polyprenylated acylphloroglucinol (PPAP) natural product hyperforin from 2-methylcyclopent-2-en-1-one is reported. This route was enabled by a diketene annulation reaction and an oxidative ring expansion strategy designed to complement the presumed biosynthesis of this complex meroterpene. The described work enables the preparation of a highly substituted bicyclo[3.3.1]nonane-1,3,5-trione motif in only six steps and thus serves as a platform for the construction of easily synthesized, highly diverse PPAPs modifiable at every position.
International Nuclear Information System (INIS)
Vogel, C.E.
1991-01-01
Confronted by changing market conditions and increased global competition, in 1983 the Commercial Nuclear Fuel Division (CNFD) of Westinghouse Electric embarked on an ambitious plan to make total quality the centerpiece of its long-term business strategy. Five years later, the division's efforts in making continuous quality improvement a way of life among its more than 2,000 employees gained national recognition when it was named a charter recipient of the Malcolm Baldridge National Quality Award. What CNFD achieved during the 1980s was a cultural transformation, characterized by an empowered work force committed to a common vision. The company's quality program development strategy is described
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.
DEFF Research Database (Denmark)
Søndergaard, Morten
2008-01-01
digitale medier er registreringen og muligheden for at opbevare og håndtere digital data uden begrænsninger. Oplevelse, registrering og bevaring knyttes sammen i en ny museal virkelighed, hvor samlingens særlige dokumentariske karakter og fokus, som er unikt for Museet for Samtidskunst, er i centrum...... at mikse deres personlige drinks. TOTAL_AKTION viser Hørbar#3, som er en videreudvikling af den første version. METASYN af Carl Emil Carlsen: Metadata er centralt for Carl Emil Carlsens projekt, der betragter museets samling som et ”univers” af værker (analoge og digitale), beskrivelser og relationer. I...
Total Logistic Plant Solutions
Directory of Open Access Journals (Sweden)
Dusan Dorcak
2016-02-01
Full Text Available The Total Logistics Plant Solutions, plant logistics system - TLPS, based on the philosophy of advanced control processes enables complex coordination of business processes and flows and the management and scheduling of production in the appropriate production plans and planning periods. Main attributes of TLPS is to create a comprehensive, multi-level, enterprise logistics information system, with a certain degree of intelligence, which accepts the latest science and research results in the field of production technology and logistics. Logistic model of company understands as a system of mutually transforming flows of materials, energy, information, finance, which is realized by chain activities and operations
International Nuclear Information System (INIS)
2003-01-01
This report presents the activities and results of the Group Total-Fina-Elf for the year 2003. It brings information and economic data on the following topics: the corporate and business; the upstream activities with the reserves, the costs, standardized measure and changes of discounted future net cash flow,oil and gas acreage, drilling, liquefied natural gas, pipelines; downstream activities with refining and marketing maps, refinery, petroleum products, sales, retail gasoline outlets; chemicals with sales and operating income by sector, major applications, base chemicals and polymers, intermediates and performance polymers. (A.L.B.)
International Nuclear Information System (INIS)
2004-01-01
This report presents the activities and results of the Group Total-Fina-Elf for the year 2004. It brings information and economic data on the following topics: the corporate and business; the upstream activities with the reserves, the costs, standardized measure and changes of discounted future net cash flow,oil and gas acreage, drilling, liquefied natural gas, pipelines; downstream activities with refining and marketing maps, refinery, petroleum products, sales, retail gasoline outlets; chemicals with sales and operating income by sector, major applications, base chemicals and polymers, intermediates and performance polymers. (A.L.B.)
International Nuclear Information System (INIS)
2004-01-01
This 2003 annual report of the Group Total provides economical results and information of the society on the following topics: keys data, the corporate governance (Directors charter, board of directors, audit committee, nomination and remuneration committee, internal control procedures, compensation of directors and executive officers), the corporate social responsibility (environmental stewardship, the future of energy management, the safety enhancement, the human resources, ethics and local development), the investor relations, the management report, the upstream exploration and production, the downstream refining, marketing, trading and shipping, the chemicals and financial and legal information. (A.L.B.)
DEFF Research Database (Denmark)
Schrøder, Henrik M.; Petersen, Michael M.
2016-01-01
Total knee arthroplasty (TKA) is a successful treatment of the osteoarthritic knee, which has increased dramatically over the last 30 years. The indication is a painful osteoarthritic knee with relevant radiographic findings and failure of conservative measures like painkillers and exercise...... surgeon seems to positively influence the rate of surgical complications and implant survival. The painful TKA knee should be thoroughly evaluated, but not revised except if a relevant indication can be established. The most frequent indications for revision are: aseptic loosening, instability, infection...
Nirawati, R.
2018-04-01
This research was conducted to see whether the variation of the solution is acceptable and easy to understand by students with different level of ability so that it can be seen the difference of students ability in facilitating the quadratic form in the upper, middle and lower groups. This research used experimental method with factorial design. Based on the result of final test analysis, there were differences of students ability in upper group, medium group, and lower group in putting squared form based on the use certain variation of solution.
Johnson, Sally C.; Boerschlein, David P.
1994-01-01
Semi-Markov models can be used to analyze the reliability of virtually any fault-tolerant system. However, the process of delineating all of the states and transitions in the model of a complex system can be devastatingly tedious and error-prone. Even with tools such as the Abstract Semi-Markov Specification Interface to the SURE Tool (ASSIST), the user must describe a system by specifying the rules governing the behavior of the system in order to generate the model. With the Table Oriented Translator to the ASSIST Language (TOTAL), the user can specify the components of a typical system and their attributes in the form of a table. The conditions that lead to system failure are also listed in a tabular form. The user can also abstractly specify dependencies with causes and effects. The level of information required is appropriate for system designers with little or no background in the details of reliability calculations. A menu-driven interface guides the user through the system description process, and the program updates the tables as new information is entered. The TOTAL program automatically generates an ASSIST input description to match the system description.
See, J. J.; Jamaian, S. S.; Salleh, R. M.; Nor, M. E.; Aman, F.
2018-04-01
This research aims to estimate the parameters of Monod model of microalgae Botryococcus Braunii sp growth by the Least-Squares method. Monod equation is a non-linear equation which can be transformed into a linear equation form and it is solved by implementing the Least-Squares linear regression method. Meanwhile, Gauss-Newton method is an alternative method to solve the non-linear Least-Squares problem with the aim to obtain the parameters value of Monod model by minimizing the sum of square error ( SSE). As the result, the parameters of the Monod model for microalgae Botryococcus Braunii sp can be estimated by the Least-Squares method. However, the estimated parameters value obtained by the non-linear Least-Squares method are more accurate compared to the linear Least-Squares method since the SSE of the non-linear Least-Squares method is less than the linear Least-Squares method.
Square Stent: A New Self-Expandable Endoluminal Device and Its Applications
International Nuclear Information System (INIS)
Pavcnik, Dusan; Uchida, Barry; Timmermans, Hans; Keller, Frederick S.; Roesch, Josef
2001-01-01
The square stent is a new, simply constructed, self-expanding device that has recently been described. Compared with other stents, the square stent has a minimal amount of metal and thus requires a smaller-diameter catheter for introduction. Despite the small amount of metal present, the square stent has adequate expansile force. We have been evaluating the square stent for various interventional applications. In addition to the basic square stent, combinations of square stents and coverings for square stents were developed and evaluated to expand its uses and indications. One of the coverings tested is a new biomaterial: small intestinal submucosa (SIS). This paper will discuss the various applications of the square stent, which include a retrievable inferior vena cava filter, vascular occluder, graft adapter, and venous and aortic valves. In addition, we will review the important properties of SIS as a covering for the square stent
Behaviour of FRP confined concrete in square columns
Directory of Open Access Journals (Sweden)
de Diego, A.
2015-12-01
Full Text Available A significant amount of research has been conducted on FRP-confined circular columns, but much less is known about rectangular/square columns in which the effectiveness of confinement is much reduced. This paper presents the results of experimental investigations on low strength square concrete columns confined with FRP. Axial compression tests were performed on ten intermediate size columns. The tests results indicate that FRP composites can significantly improve the bearing capacity and ductility of square section reinforced concrete columns with rounded corners. The strength enhancement ratio is greater the lower the concrete strength and also increases with the stiffness of the jacket. The confined concrete behaviour was predicted according to the more accepted theoretical models and compared with experimental results. There are two key parameters which critically influence the fitting of the models: the strain efficiency factor and the effect of confinement in non-circular sections.La mayoría de las investigaciones sobre hormigón confinado con FRP se han realizado sobre pilares de sección circular, pero el comportamiento en secciones cuadradas/rectangulares, donde el confinamiento es menos eficaz, es mucho menos conocido. Este trabajo presenta los resultados de un estudio experimental sobre probetas de hormigón de baja resistencia y sección cuadrada. Se han ensayado a compresión centrada diez probetas de tamaño intermedio. Los resultados indican que el confinamiento mejora significativamente la resistencia y ductilidad del hormigón en columnas de sección cuadrada con las esquinas redondeadas. El incremento de resistencia es mayor cuanto menor es la resistencia del hormigón sin confinar y también aumenta con la rigidez del encamisado. Los resultados se compararon con los obtenidos según los modelos teóricos más aceptados. Hay dos parámetros críticos en el ajuste de los modelos: el factor de eficiencia de la deformación y el
Motion of an elastic capsule in a square microfluidic channel.
Kuriakose, S; Dimitrakopoulos, P
2011-07-01
In the present study we investigate computationally the steady-state motion of an elastic capsule along the centerline of a square microfluidic channel and compare it with that in a cylindrical tube. In particular, we consider a slightly over-inflated elastic capsule made of a strain-hardening membrane with comparable shearing and area-dilatation resistance. Under the conditions studied in this paper (i.e., small, moderate, and large capsules at low and moderate flow rates), the capsule motion in a square channel is similar to and thus governed by the same scaling laws with the capsule motion in a cylindrical tube, even though in the channel the cross section in the upstream portion of large capsules is nonaxisymmetric (i.e., square-like with rounded corners). When the hydrodynamic forces on the membrane increase, the capsule develops a pointed downstream edge and a flattened rear (possibly with a negative curvature) so that the restoring tension forces are increased as also happens with droplets. Membrane tensions increase significantly with the capsule size while the area near the downstream tip is the most probable to rupture when a capsule flows in a microchannel. Because the membrane tensions increase with the interfacial deformation, a suitable Landau-Levich-Derjaguin-Bretherton analysis reveals that the lubrication film thickness h for large capsules depends on both the capillary number Ca and the capsule size a; our computations determine the latter dependence to be (in dimensionless form) h ~ a(-2) for the large capsules studied in this work. For small and moderate capsule sizes a, the capsule velocity Ux and additional pressure drop ΔP+ are governed by the same scaling laws as for high-viscosity droplets. The velocity and additional pressure drop of large thick capsules also follow the dynamics of high-viscosity droplets, and are affected by the lubrication film thickness. The motion of our large thick capsules is characterized by a Ux-U ~ h ~ a(-2
Analytic representation of the square-root operator
International Nuclear Information System (INIS)
Gill, Tepper L; Zachary, W W
2005-01-01
In this paper, we use the theory of fractional powers of linear operators to construct a general (analytic) representation theory for the square-root energy operator of relativistic quantum theory, which is valid for all values of the spin. We focus on the spin 1/2 case, considering a few simple yet solvable and physically interesting cases, in order to understand how to interpret the operator. Our general representation is uniquely determined by the Green's function for the corresponding Schroedinger equation. We find that, in general, the operator has a representation as a nonlocal composite of (at least) three singularities. In the standard interpretation, the particle component has two negative parts and one (hard core) positive part, while the antiparticle component has two positive parts and one (hard core) negative part. This effect is confined within a Compton wavelength such that, at the point of singularity, they cancel each other providing a finite result. Furthermore, the operator looks like the identity outside a few Compton wavelengths (cut-off). To our knowledge, this is the first example of a physically relevant operator with these properties. When the magnetic field is constant, we obtain an additional singularity, which could be interpreted as particle absorption and emission. The physical picture that emerges is that, in addition to the confined singularities and the additional attractive (repulsive) term, the effective mass of the composite acquires an oscillatory behaviour. We also derive an alternative relationship between the Dirac equation (with minimal coupling) and the square-root equation that is somewhat closer than the one obtained via the Foldy-Wouthuysen method, in that there is no change in the wavefunction. This is accomplished by considering the scalar potential to be a part of the mass. This approach leads to a new Klein-Gordon equation and a new square-root equation, both of which can have the same eigenfunctions and (related
Least-squares reverse time migration of multiples
Zhang, Dongliang
2013-12-06
The theory of least-squares reverse time migration of multiples (RTMM) is presented. In this method, least squares migration (LSM) is used to image free-surface multiples where the recorded traces are used as the time histories of the virtual sources at the hydrophones and the surface-related multiples are the observed data. For a single source, the entire free-surface becomes an extended virtual source where the downgoing free-surface multiples more fully illuminate the subsurface compared to the primaries. Since each recorded trace is treated as the time history of a virtual source, knowledge of the source wavelet is not required and the ringy time series for each source is automatically deconvolved. If the multiples can be perfectly separated from the primaries, numerical tests on synthetic data for the Sigsbee2B and Marmousi2 models show that least-squares reverse time migration of multiples (LSRTMM) can significantly improve the image quality compared to RTMM or standard reverse time migration (RTM) of primaries. However, if there is imperfect separation and the multiples are strongly interfering with the primaries then LSRTMM images show no significant advantage over the primary migration images. In some cases, they can be of worse quality. Applying LSRTMM to Gulf of Mexico data shows higher signal-to-noise imaging of the salt bottom and top compared to standard RTM images. This is likely attributed to the fact that the target body is just below the sea bed so that the deep water multiples do not have strong interference with the primaries. Migrating a sparsely sampled version of the Marmousi2 ocean bottom seismic data shows that LSM of primaries and LSRTMM provides significantly better imaging than standard RTM. A potential liability of LSRTMM is that multiples require several round trips between the reflector and the free surface, so that high frequencies in the multiples suffer greater attenuation compared to the primary reflections. This can lead to lower
Olivares, A.; Górriz, J. M.; Ramírez, J.; Olivares, G.
2011-02-01
Inertial sensors are widely used in human body motion monitoring systems since they permit us to determine the position of the subject's limbs. Limb angle measurement is carried out through the integration of the angular velocity measured by a rate sensor and the decomposition of the components of static gravity acceleration measured by an accelerometer. Different factors derived from the sensors' nature, such as the angle random walk and dynamic bias, lead to erroneous measurements. Dynamic bias effects can be reduced through the use of adaptive filtering based on sensor fusion concepts. Most existing published works use a Kalman filtering sensor fusion approach. Our aim is to perform a comparative study among different adaptive filters. Several least mean squares (LMS), recursive least squares (RLS) and Kalman filtering variations are tested for the purpose of finding the best method leading to a more accurate and robust limb angle measurement. A new angle wander compensation sensor fusion approach based on LMS and RLS filters has been developed.
International Nuclear Information System (INIS)
Olivares, A; Olivares, G; Górriz, J M; Ramírez, J
2011-01-01
Inertial sensors are widely used in human body motion monitoring systems since they permit us to determine the position of the subject's limbs. Limb angle measurement is carried out through the integration of the angular velocity measured by a rate sensor and the decomposition of the components of static gravity acceleration measured by an accelerometer. Different factors derived from the sensors' nature, such as the angle random walk and dynamic bias, lead to erroneous measurements. Dynamic bias effects can be reduced through the use of adaptive filtering based on sensor fusion concepts. Most existing published works use a Kalman filtering sensor fusion approach. Our aim is to perform a comparative study among different adaptive filters. Several least mean squares (LMS), recursive least squares (RLS) and Kalman filtering variations are tested for the purpose of finding the best method leading to a more accurate and robust limb angle measurement. A new angle wander compensation sensor fusion approach based on LMS and RLS filters has been developed
Total process surveillance: (TOPS)
International Nuclear Information System (INIS)
Millar, J.H.P.
1992-01-01
A Total Process Surveillance system is under development which can provide, in real-time, additional process information from a limited number of raw measurement signals. This is achieved by using a robust model based observer to generate estimates of the process' internal states. The observer utilises the analytical reduncancy among a diverse range of transducers and can thus accommodate off-normal conditions which lead to transducer loss or damage. The modular hierarchical structure of the system enables the maximum amount of information to be assimilated from the available instrument signals no matter how diverse. This structure also constitutes a data reduction path thus reducing operator cognitive overload from a large number of varying, and possibly contradictory, raw plant signals. (orig.)
International Nuclear Information System (INIS)
Signoret, St.
2008-01-01
So as to prepare the future of their industrial sector,the Total company plans to invest (14 billion Euros in 2008) to increase its production capacities and strengthen in of other activities as the liquefied natural gas and the renewable energies; EDF plans to inject 35 billion Euros over three years to multiply the new projects of power plants (wind turbines, coal in Germany, gas in Great Britain and nuclear power in Flamanville). EDF wants to exploit its knowledge of leader to run more than ten E.P.R.(European pressurized water reactor) in the world before 2020, projects are in examination with China, Great Britain, South Africa and United States. (N.C.)
International Nuclear Information System (INIS)
Chiandone, A.C.
1990-01-01
The Total Quality at Source philosophy is based on optimizing the effectiveness of people in achieving ZERO-DEFECT results. In this paper a philosophy of what, I have come to perceive, it takes to get people to perform to the very best of their abilities and thereby achieve the best results they can, is presented. In the examples I shall describe I have played an instrumental role since it has become my belief that any job can always be done better provided that the people doing it can themselves become convinced that they can do better. Clearly there are many ideas on how to do this. The philosophy that I am presenting in this paper is based on my own experience, where I have both participated and observed it being applied; its effectiveness may be judged by the results. (author)
Total ankle joint replacement.
2016-02-01
Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Least Squares Adjustment: Linear and Nonlinear Weighted Regression Analysis
DEFF Research Database (Denmark)
Nielsen, Allan Aasbjerg
2007-01-01
This note primarily describes the mathematics of least squares regression analysis as it is often used in geodesy including land surveying and satellite positioning applications. In these fields regression is often termed adjustment. The note also contains a couple of typical land surveying...... and satellite positioning application examples. In these application areas we are typically interested in the parameters in the model typically 2- or 3-D positions and not in predictive modelling which is often the main concern in other regression analysis applications. Adjustment is often used to obtain...... the clock error) and to obtain estimates of the uncertainty with which the position is determined. Regression analysis is used in many other fields of application both in the natural, the technical and the social sciences. Examples may be curve fitting, calibration, establishing relationships between...
Recent developments: PKI square dish for the Soleras Project
Rogers, W. E.
1984-03-01
The Square Dish solar collectors are subjected to rigorous design attention regarding corrosion at the site, and certification of the collector structure. The microprocessor controls and tracking mechanisms are improved in the areas of fail safe operations, durability, and low parasitic power requirements. Prototype testing demonstrates performance efficiency of approximately 72% at 730 F outlet temperature. Studies are conducted that include developing formal engineering design studies, developing formal engineering design drawing and fabrication details, establishing subcontracts for fabrication of major components, and developing a rigorous quality control system. The improved design is more cost effective to product and the extensive manuals developed for assembly and operation/maintenance result in faster field assembly and ease of operation.
The digital Newsroom – from Square to Circle
DEFF Research Database (Denmark)
Hassall Thomsen, Line Hassall
in and with the newsroom it intends to map out how the setting affects journalistic culture of practice. Drawing on recent fieldwork at BBC News, DRs TV Avisen and ITV News as well as TV2 Nyhederne, I will investigate this new trend in newsrooms from both Public Broadcasters to more commercial broadcasters in both UK...... square one, to a round multi media one is now becoming the setting for both national TV news bulletins in both Denmark and the UK. The aim with this paper is to explore this new newsroom and what it means to the journalists in it. The paper will seek to answer questions such as; How does the physical...... room affect the social interactions in it? What does the organisation of people and technology in the newsroom do for the journalistic working process? And which hierarchal structure does the room feed into? While investigating symbolic and face to face interaction between journalists...
Risk and Management Control: A Partial Least Square Modelling Approach
DEFF Research Database (Denmark)
Nielsen, Steen; Pontoppidan, Iens Christian
Risk and economic theory goes many year back (e.g. to Keynes & Knight 1921) and risk/uncertainty belong to one of the explanations for the existence of the firm (Coarse, 1937). The present financial crisis going on in the past years have re-accentuated risk and the need of coherence...... and interrelations between risk and areas within management accounting. The idea is that management accounting should be able to conduct a valid feed forward but also predictions for decision making including risk. This study reports the test of a theoretical model using partial least squares (PLS) on survey data...... and a external attitude dimension. The results have important implications for both management control research and for the management control systems design for the way accountants consider the element of risk in their different tasks, both operational and strategic. Specifically, it seems that different risk...
Consistent Partial Least Squares Path Modeling via Regularization.
Jung, Sunho; Park, JaeHong
2018-01-01
Partial least squares (PLS) path modeling is a component-based structural equation modeling that has been adopted in social and psychological research due to its data-analytic capability and flexibility. A recent methodological advance is consistent PLS (PLSc), designed to produce consistent estimates of path coefficients in structural models involving common factors. In practice, however, PLSc may frequently encounter multicollinearity in part because it takes a strategy of estimating path coefficients based on consistent correlations among independent latent variables. PLSc has yet no remedy for this multicollinearity problem, which can cause loss of statistical power and accuracy in parameter estimation. Thus, a ridge type of regularization is incorporated into PLSc, creating a new technique called regularized PLSc. A comprehensive simulation study is conducted to evaluate the performance of regularized PLSc as compared to its non-regularized counterpart in terms of power and accuracy. The results show that our regularized PLSc is recommended for use when serious multicollinearity is present.
A Galerkin least squares approach to viscoelastic flow.
Energy Technology Data Exchange (ETDEWEB)
Rao, Rekha R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schunk, Peter Randall [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-10-01
A Galerkin/least-squares stabilization technique is applied to a discrete Elastic Viscous Stress Splitting formulation of for viscoelastic flow. From this, a possible viscoelastic stabilization method is proposed. This method is tested with the flow of an Oldroyd-B fluid past a rigid cylinder, where it is found to produce inaccurate drag coefficients. Furthermore, it fails for relatively low Weissenberg number indicating it is not suited for use as a general algorithm. In addition, a decoupled approach is used as a way separating the constitutive equation from the rest of the system. A Pressure Poisson equation is used when the velocity and pressure are sought to be decoupled, but this fails to produce a solution when inflow/outflow boundaries are considered. However, a coupled pressure-velocity equation with a decoupled constitutive equation is successful for the flow past a rigid cylinder and seems to be suitable as a general-use algorithm.
Least Squares Shadowing sensitivity analysis of chaotic limit cycle oscillations
Energy Technology Data Exchange (ETDEWEB)
Wang, Qiqi, E-mail: qiqi@mit.edu; Hu, Rui, E-mail: hurui@mit.edu; Blonigan, Patrick, E-mail: blonigan@mit.edu
2014-06-15
The adjoint method, among other sensitivity analysis methods, can fail in chaotic dynamical systems. The result from these methods can be too large, often by orders of magnitude, when the result is the derivative of a long time averaged quantity. This failure is known to be caused by ill-conditioned initial value problems. This paper overcomes this failure by replacing the initial value problem with the well-conditioned “least squares shadowing (LSS) problem”. The LSS problem is then linearized in our sensitivity analysis algorithm, which computes a derivative that converges to the derivative of the infinitely long time average. We demonstrate our algorithm in several dynamical systems exhibiting both periodic and chaotic oscillations.
Cold atoms at unitarity and inverse square interaction
Energy Technology Data Exchange (ETDEWEB)
Bhaduri, R K [Department of Physics and Astronomy, McMaster University, Hamilton L8S 4M1 (Canada); Murthy, M V N [The Institute of Mathematical Sciences, Chennai 600113 (India); Srivastava, M K [Department of Physics, Indian Institute of Technology, Roorkee 247667 (India)
2009-12-14
Consider two identical atoms in a spherical harmonic oscillator interacting with a zero-range interaction which is tuned to produce an s-wave zero-energy bound state. The quantum spectrum of the system is known to be exactly solvable. We note that the same partial wave quantum spectrum is obtained by the one-dimensional scale-invariant inverse square potential. Long known as the Calogero-Sutherland-Moser (CSM) model, it leads to the fractional exclusion statistics (FES) of Haldane and Wu. The statistical parameter is deduced from the analytically calculated second virial coefficient. When FES is applied to a Fermi gas at unitarity, it gives good agreement with experimental data without the use of any free parameter.
Classical and quantum motion in an inverse square potential
International Nuclear Information System (INIS)
Avila-Aoki, M.; Cisneros, C.; Martinez-y-Romero, R.P.; Nunez-Yepez, H.N.; Salas-Brito, A.L.
2009-01-01
Classical motion in an inverse square potential is shown to be equivalent to free motion on a hyperbola. The existence of a classical splitting between the q>0 and q<0 regions of motion is demonstrated. We show that this last property may be regarded as the classical counterpart of the superselection rule occurring in the corresponding quantum problem. We solve the quantum problem in momentum space finding that there is no way of quantizing its energy but that the eigenfunctions suffice to describe the single renormalized bound state of the system. The dynamical symmetry of the classical problem is found to be O(1,1). Both this symmetry and the symmetry of inversion through the origin are found to be broken
Machine Learning with Squared-Loss Mutual Information
Directory of Open Access Journals (Sweden)
Masashi Sugiyama
2012-12-01
Full Text Available Mutual information (MI is useful for detecting statistical independence between random variables, and it has been successfully applied to solving various machine learning problems. Recently, an alternative to MI called squared-loss MI (SMI was introduced. While ordinary MI is the Kullback–Leibler divergence from the joint distribution to the product of the marginal distributions, SMI is its Pearson divergence variant. Because both the divergences belong to the ƒ-divergence family, they share similar theoretical properties. However, a notable advantage of SMI is that it can be approximated from data in a computationally more efficient and numerically more stable way than ordinary MI. In this article, we review recent development in SMI approximation based on direct density-ratio estimation and SMI-based machine learning techniques such as independence testing, dimensionality reduction, canonical dependency analysis, independent component analysis, object matching, clustering, and causal inference.
Connectivity percolation in suspensions of attractive square-well spherocylinders.
Dixit, Mohit; Meyer, Hugues; Schilling, Tanja
2016-01-01
We have studied the connectivity percolation transition in suspensions of attractive square-well spherocylinders by means of Monte Carlo simulation and connectedness percolation theory. In the 1980s the percolation threshold of slender fibers has been predicted to scale as the fibers' inverse aspect ratio [Phys. Rev. B 30, 3933 (1984)PRBMDO1098-012110.1103/PhysRevB.30.3933]. The main finding of our study is that the attractive spherocylinder system reaches this inverse scaling regime at much lower aspect ratios than found in suspensions of hard spherocylinders. We explain this difference by showing that third virial corrections of the pair connectedness functions, which are responsible for the deviation from the scaling regime, are less important for attractive potentials than for hard particles.
Square chart of nuclides with the best coordinates
International Nuclear Information System (INIS)
Wang Yuying
2001-01-01
It analyzes upper limiting feature of even Z=60-82 in different charts of nuclides. It has illustrated that the break line of upper limiting Z=60-82 in the chart of nucleus with proton number Z and neutron number N, parameters Z and H (=N-Z), two new parameters S(=2Z-N) and H, and parameters K (=S-H) and H, in proper order, it shows that the break line trends from the left lower to the right upper, the line alternates with horizontal and vertical, and the line trends from the right lower to the left upper. Here it finds that the square chart of nuclides places the middle among these charts. It shows that nuclei distribution is concentrated, so are scope of whole region of nuclides in the different charts of nuclides
Emulating facial biomechanics using multivariate partial least squares surrogate models.
Wu, Tim; Martens, Harald; Hunter, Peter; Mithraratne, Kumar
2014-11-01
A detailed biomechanical model of the human face driven by a network of muscles is a useful tool in relating the muscle activities to facial deformations. However, lengthy computational times often hinder its applications in practical settings. The objective of this study is to replace precise but computationally demanding biomechanical model by a much faster multivariate meta-model (surrogate model), such that a significant speedup (to real-time interactive speed) can be achieved. Using a multilevel fractional factorial design, the parameter space of the biomechanical system was probed from a set of sample points chosen to satisfy maximal rank optimality and volume filling. The input-output relationship at these sampled points was then statistically emulated using linear and nonlinear, cross-validated, partial least squares regression models. It was demonstrated that these surrogate models can mimic facial biomechanics efficiently and reliably in real-time. Copyright © 2014 John Wiley & Sons, Ltd.
Weighted least squares phase unwrapping based on the wavelet transform
Chen, Jiafeng; Chen, Haiqin; Yang, Zhengang; Ren, Haixia
2007-01-01
The weighted least squares phase unwrapping algorithm is a robust and accurate method to solve phase unwrapping problem. This method usually leads to a large sparse linear equation system. Gauss-Seidel relaxation iterative method is usually used to solve this large linear equation. However, this method is not practical due to its extremely slow convergence. The multigrid method is an efficient algorithm to improve convergence rate. However, this method needs an additional weight restriction operator which is very complicated. For this reason, the multiresolution analysis method based on the wavelet transform is proposed. By applying the wavelet transform, the original system is decomposed into its coarse and fine resolution levels and an equivalent equation system with better convergence condition can be obtained. Fast convergence in separate coarse resolution levels speeds up the overall system convergence rate. The simulated experiment shows that the proposed method converges faster and provides better result than the multigrid method.
Quantum information entropies for a squared tangent potential well
Energy Technology Data Exchange (ETDEWEB)
Dong, Shishan [Information and Engineering College, DaLian University, 116622 (China); Sun, Guo-Hua, E-mail: sunghdb@yahoo.com [Centro Universitario Valle de Chalco, Universidad Autónoma del Estado de México, Valle de Chalco Solidaridad, Estado de México, 56615 (Mexico); Dong, Shi-Hai, E-mail: dongsh2@yahoo.com [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Unidad Profesional Adolfo López Mateos, Edificio 9, México D.F. 07738 (Mexico); Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States); Draayer, J.P., E-mail: draayer@sura.org [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States)
2014-01-10
The particle in a symmetrical squared tangent potential well is studied by examining its Shannon information entropy and standard deviations. The position and momentum information entropy densities ρ{sub s}(x), ρ{sub s}(p) and probability densities ρ(x), ρ(p) are illustrated with different potential range L and potential depth U. We present analytical position information entropies S{sub x} for the lowest two states. We observe that the sum of position and momentum entropies S{sub x} and S{sub p} expressed by Bialynicki-Birula–Mycielski (BBM) inequality is satisfied. Some eigenstates exhibit entropy squeezing in the position. The entropy squeezing in position will be compensated by an increase in momentum entropy. We also note that the S{sub x} increases with the potential range L, while decreases with the potential depth U. The variation of S{sub p} is contrary to that of S{sub x}.
Quantum information entropies for a squared tangent potential well
International Nuclear Information System (INIS)
Dong, Shishan; Sun, Guo-Hua; Dong, Shi-Hai; Draayer, J.P.
2014-01-01
The particle in a symmetrical squared tangent potential well is studied by examining its Shannon information entropy and standard deviations. The position and momentum information entropy densities ρ s (x), ρ s (p) and probability densities ρ(x), ρ(p) are illustrated with different potential range L and potential depth U. We present analytical position information entropies S x for the lowest two states. We observe that the sum of position and momentum entropies S x and S p expressed by Bialynicki-Birula–Mycielski (BBM) inequality is satisfied. Some eigenstates exhibit entropy squeezing in the position. The entropy squeezing in position will be compensated by an increase in momentum entropy. We also note that the S x increases with the potential range L, while decreases with the potential depth U. The variation of S p is contrary to that of S x .
Opposing flow in square porous annulus: Influence of Dufour effect
International Nuclear Information System (INIS)
Athani, Abdulgaphur; Al-Rashed, Abdullah A. A. A.; Khaleed, H. M. T.
2016-01-01
Heat and mass transfer in porous medium is very important area of research which is also termed as double diffusive convection or thermo-solutal convection. The buoyancy ratio which is the ratio of thermal to concentration buoyancy can have negative values thus leading to opposing flow. This article is aimed to study the influence of Dufour effect on the opposing flow in a square porous annulus. The partial differential equations that govern the heat and mass transfer behavior inside porous medium are solved using finite element method. A three node triangular element is used to divide the porous domain into smaller elements. Results are presented with respect to geometric and physical parameters such as duct diameter ratio, Rayleigh number, radiation parameter etc. It is found that the heat transfer increase with increase in Rayleigh number and radiation parameter. It is observed that Dufour coefficient has more influence on velocity profile.
Opposing flow in square porous annulus: Influence of Dufour effect
Energy Technology Data Exchange (ETDEWEB)
Athani, Abdulgaphur, E-mail: abbu.bec@gmail.com [Dept. of Mechanical Engineering, Anjuman Institute of Technology & Management, Bhatkal (India); Al-Rashed, Abdullah A. A. A., E-mail: aa.alrashed@paaet.edu.kw [Dept. of Automotive and Marine Engineering Technology, College of Technological Studies, The Public Authority for Applied Education and Training (Kuwait); Khaleed, H. M. T., E-mail: khalid-tan@yahoo.com [Dept of Mechanical Engineering, Faculty of Engineering, Islamic University, Madinah Munawwarra (Saudi Arabia)
2016-06-21
Heat and mass transfer in porous medium is very important area of research which is also termed as double diffusive convection or thermo-solutal convection. The buoyancy ratio which is the ratio of thermal to concentration buoyancy can have negative values thus leading to opposing flow. This article is aimed to study the influence of Dufour effect on the opposing flow in a square porous annulus. The partial differential equations that govern the heat and mass transfer behavior inside porous medium are solved using finite element method. A three node triangular element is used to divide the porous domain into smaller elements. Results are presented with respect to geometric and physical parameters such as duct diameter ratio, Rayleigh number, radiation parameter etc. It is found that the heat transfer increase with increase in Rayleigh number and radiation parameter. It is observed that Dufour coefficient has more influence on velocity profile.
Chi-square tests for comparing weighted histograms
International Nuclear Information System (INIS)
Gagunashvili, N.D.
2010-01-01
Weighted histograms in Monte Carlo simulations are often used for the estimation of probability density functions. They are obtained as a result of random experiments with random events that have weights. In this paper, the bin contents of a weighted histogram are considered as a sum of random variables with a random number of terms. Generalizations of the classical chi-square test for comparing weighted histograms are proposed. Numerical examples illustrate an application of the tests for the histograms with different statistics of events and different weighted functions. The proposed tests can be used for the comparison of experimental data histograms with simulated data histograms as well as for the two simulated data histograms.
Square matrices of order 2 theory, applications, and problems
Pop, Vasile
2017-01-01
This unique and innovative book presents an exciting and complete detail of all the important topics related to the theory of square matrices of order 2. The readers exploring every detailed aspect of matrix theory are gently led toward understanding advanced topics. They will follow every notion of matrix theory with ease, accumulating a thorough understanding of algebraic and geometric aspects of matrices of order 2. The prime jewel of this book is its offering of an unusual collection of problems, theoretically motivated, most of which are new, original, and seeing the light of publication for the first time in the literature. Nearly all of the exercises are presented with detailed solutions and vary in difficulty from easy to more advanced. Many problems are particularly challenging. These, and not only these, invite the reader to unleash their creativity and research capabilities and to discover their own methods of attacking a problem. Matrices have a vast practical importance to mathematics, science, a...
Intelligent Quality Prediction Using Weighted Least Square Support Vector Regression
Yu, Yaojun
A novel quality prediction method with mobile time window is proposed for small-batch producing process based on weighted least squares support vector regression (LS-SVR). The design steps and learning algorithm are also addressed. In the method, weighted LS-SVR is taken as the intelligent kernel, with which the small-batch learning is solved well and the nearer sample is set a larger weight, while the farther is set the smaller weight in the history data. A typical machining process of cutting bearing outer race is carried out and the real measured data are used to contrast experiment. The experimental results demonstrate that the prediction accuracy of the weighted LS-SVR based model is only 20%-30% that of the standard LS-SVR based one in the same condition. It provides a better candidate for quality prediction of small-batch producing process.
Thermodynamic properties of short-range square well fluid
López-Rendón, R.; Reyes, Y.; Orea, P.
2006-08-01
The interfacial properties of short-range square well fluid with λ =1.15, 1.25, and 1.375 were determined by using single canonical Monte Carlo simulations. Simulations were carried out in the vapor-liquid region. The coexistence curves of these models were calculated and compared to those previously reported in the literature and good agreement was found among them. We found that the surface tension curves for any potential model of short range form a single master curve when we plot γ* vs T /Tc. It is demonstrated that the critical reduced second virial coefficient B2* as a function of interaction range or Tc* is not constant.
Flow Applications of the Least Squares Finite Element Method
Jiang, Bo-Nan
1998-01-01
The main thrust of the effort has been towards the development, analysis and implementation of the least-squares finite element method (LSFEM) for fluid dynamics and electromagnetics applications. In the past year, there were four major accomplishments: 1) special treatments in computational fluid dynamics and computational electromagnetics, such as upwinding, numerical dissipation, staggered grid, non-equal order elements, operator splitting and preconditioning, edge elements, and vector potential are unnecessary; 2) the analysis of the LSFEM for most partial differential equations can be based on the bounded inverse theorem; 3) the finite difference and finite volume algorithms solve only two Maxwell equations and ignore the divergence equations; and 4) the first numerical simulation of three-dimensional Marangoni-Benard convection was performed using the LSFEM.
Quantum square-well with logarithmic central spike
Znojil, Miloslav; Semorádová, Iveta
2018-01-01
Singular repulsive barrier V (x) = -gln(|x|) inside a square-well is interpreted and studied as a linear analog of the state-dependent interaction ℒeff(x) = -gln[ψ∗(x)ψ(x)] in nonlinear Schrödinger equation. In the linearized case, Rayleigh-Schrödinger perturbation theory is shown to provide a closed-form spectrum at sufficiently small g or after an amendment of the unperturbed Hamiltonian. At any spike strength g, the model remains solvable numerically, by the matching of wave functions. Analytically, the singularity is shown regularized via the change of variables x = expy which interchanges the roles of the asymptotic and central boundary conditions.
Direct simulation of natural convection in square porous enclosure
International Nuclear Information System (INIS)
Pourshaghaghy, A.; Hakkaki-Fard, A.; Mahdavi-Nejad, A.
2007-01-01
In this article, natural convection in a square porous enclosure is simulated by a direct numerical method. The solution method is based on a random distribution of solid blocks, which resembles the porous media within the cavity. The Navier-Stokes equations are solved directly in the fluid region without the assumption of volume averaging. The no-slip condition is applied on the surface of any solid particle, and the energy transport equation is solved separately for the solid phase and fluid flow. The local and average Nusselt numbers are presented for steady state for two different cases of thermal boundary conditions of the cavity walls. An oscillatory solution is observed for the local Nu number on the surface of the enclosure, and the critical Ra numbers are found in which natural convection flow is started within the cavity
Universal quantum computation with temporal-mode bilayer square lattices
Alexander, Rafael N.; Yokoyama, Shota; Furusawa, Akira; Menicucci, Nicolas C.
2018-03-01
We propose an experimental design for universal continuous-variable quantum computation that incorporates recent innovations in linear-optics-based continuous-variable cluster state generation and cubic-phase gate teleportation. The first ingredient is a protocol for generating the bilayer-square-lattice cluster state (a universal resource state) with temporal modes of light. With this state, measurement-based implementation of Gaussian unitary gates requires only homodyne detection. Second, we describe a measurement device that implements an adaptive cubic-phase gate, up to a random phase-space displacement. It requires a two-step sequence of homodyne measurements and consumes a (non-Gaussian) cubic-phase state.
semPLS: Structural Equation Modeling Using Partial Least Squares
Directory of Open Access Journals (Sweden)
Armin Monecke
2012-05-01
Full Text Available Structural equation models (SEM are very popular in many disciplines. The partial least squares (PLS approach to SEM offers an alternative to covariance-based SEM, which is especially suited for situations when data is not normally distributed. PLS path modelling is referred to as soft-modeling-technique with minimum demands regarding mea- surement scales, sample sizes and residual distributions. The semPLS package provides the capability to estimate PLS path models within the R programming environment. Different setups for the estimation of factor scores can be used. Furthermore it contains modular methods for computation of bootstrap confidence intervals, model parameters and several quality indices. Various plot functions help to evaluate the model. The well known mobile phone dataset from marketing research is used to demonstrate the features of the package.
Least-squares reverse time migration with radon preconditioning
Dutta, Gaurav
2016-09-06
We present a least-squares reverse time migration (LSRTM) method using Radon preconditioning to regularize noisy or severely undersampled data. A high resolution local radon transform is used as a change of basis for the reflectivity and sparseness constraints are applied to the inverted reflectivity in the transform domain. This reflects the prior that for each location of the subsurface the number of geological dips is limited. The forward and the adjoint mapping of the reflectivity to the local Radon domain and back are done through 3D Fourier-based discrete Radon transform operators. The sparseness is enforced by applying weights to the Radon domain components which either vary with the amplitudes of the local dips or are thresholded at given quantiles. Numerical tests on synthetic and field data validate the effectiveness of the proposed approach in producing images with improved SNR and reduced aliasing artifacts when compared with standard RTM or LSRTM.
Cognitive assessment in mathematics with the least squares distance method.
Ma, Lin; Çetin, Emre; Green, Kathy E
2012-01-01
This study investigated the validation of comprehensive cognitive attributes of an eighth-grade mathematics test using the least squares distance method and compared performance on attributes by gender and region. A sample of 5,000 students was randomly selected from the data of the 2005 Turkish national mathematics assessment of eighth-grade students. Twenty-five math items were assessed for presence or absence of 20 cognitive attributes (content, cognitive processes, and skill). Four attributes were found to be misspecified or nonpredictive. However, results demonstrated the validity of cognitive attributes in terms of the revised set of 17 attributes. The girls had similar performance on the attributes as the boys. The students from the two eastern regions significantly underperformed on the most attributes.
Classical and quantum dynamics in an inverse square potential
International Nuclear Information System (INIS)
Guillaumín-España, Elisa; Núñez-Yépez, H. N.; Salas-Brito, A. L.
2014-01-01
The classical motion of a particle in a 3D inverse square potential with negative energy, E, is shown to be geodesic, i.e., equivalent to the particle's free motion on a non-compact phase space manifold irrespective of the sign of the coupling constant. We thus establish that all its classical orbits with E < 0 are unbounded. To analyse the corresponding quantum problem, the Schrödinger equation is solved in momentum space. No discrete energy levels exist in the unrenormalized case and the system shows a complete “fall-to-the-center” with an energy spectrum unbounded by below. Such behavior corresponds to the non-existence of bound classical orbits. The symmetry of the problem is SO(3) × SO(2, 1) corroborating previously obtained results
Classical and quantum dynamics in an inverse square potential
Energy Technology Data Exchange (ETDEWEB)
Guillaumín-España, Elisa, E-mail: ege@correo.azc.uam.mx [Laboratorio de Sistemas Dinámicos, Departamento de Ciencias Básicas, Universidad Autónoma Metropolitana, Unidad Azcapotzalco, Azcapotzalco CP 02200 D. F. (Mexico); Núñez-Yépez, H. N., E-mail: nyhn@xanum.uam.mx [Departamento de Física, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Apartado Postal 55-534, Iztapalapa CP 09340 D. F. (Mexico); Salas-Brito, A. L., E-mail: asb@correo.azc.uam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México (ICN-UNAM), Apartado Postal 70-543, 04510 México D F (Mexico)
2014-10-15
The classical motion of a particle in a 3D inverse square potential with negative energy, E, is shown to be geodesic, i.e., equivalent to the particle's free motion on a non-compact phase space manifold irrespective of the sign of the coupling constant. We thus establish that all its classical orbits with E < 0 are unbounded. To analyse the corresponding quantum problem, the Schrödinger equation is solved in momentum space. No discrete energy levels exist in the unrenormalized case and the system shows a complete “fall-to-the-center” with an energy spectrum unbounded by below. Such behavior corresponds to the non-existence of bound classical orbits. The symmetry of the problem is SO(3) × SO(2, 1) corroborating previously obtained results.
The WIMP Forest: Indirect Detection of a Chiral Square
Energy Technology Data Exchange (ETDEWEB)
Bertone, Gianfranco; Jackson, C.B.; Shaughnessy, Gabe; Tait, Tim M.P.; Vallinotto, Alberto
2009-04-01
The spectrum of photons arising from WIMP annihilation carries a detailed imprint of the structure of the dark sector. In particular, loop-level annihilations into a photon and another boson can in principle lead to a series of lines (a WIMP forest) at energies up to the WIMP mass. A specific model which illustrates this feature nicely is a theory of two universal extra dimensions compactified on a chiral square. Aside from the continuum emission, which is a generic prediction of most dark matter candidates, we find a 'forest' of prominent annihilation lines that, after convolution with the angular resolution of current experiments, leads to a distinctive (2-bump plus continuum) spectrum, which may be visible in the near future with the Fermi Gamma-Ray Space Telescope (formerly known as GLAST).
Regularized plane-wave least-squares Kirchhoff migration
Wang, Xin
2013-09-22
A Kirchhoff least-squares migration (LSM) is developed in the prestack plane-wave domain to increase the quality of migration images. A regularization term is included that accounts for mispositioning of reflectors due to errors in the velocity model. Both synthetic and field results show that: 1) LSM with a reflectivity model common for all the plane-wave gathers provides the best image when the migration velocity model is accurate, but it is more sensitive to the velocity errors, 2) the regularized plane-wave LSM is more robust in the presence of velocity errors, and 3) LSM achieves both computational and IO saving by plane-wave encoding compared to shot-domain LSM for the models tested.
Robust Homography Estimation Based on Nonlinear Least Squares Optimization
Directory of Open Access Journals (Sweden)
Wei Mou
2014-01-01
Full Text Available The homography between image pairs is normally estimated by minimizing a suitable cost function given 2D keypoint correspondences. The correspondences are typically established using descriptor distance of keypoints. However, the correspondences are often incorrect due to ambiguous descriptors which can introduce errors into following homography computing step. There have been numerous attempts to filter out these erroneous correspondences, but it is unlikely to always achieve perfect matching. To deal with this problem, we propose a nonlinear least squares optimization approach to compute homography such that false matches have no or little effect on computed homography. Unlike normal homography computation algorithms, our method formulates not only the keypoints’ geometric relationship but also their descriptor similarity into cost function. Moreover, the cost function is parametrized in such a way that incorrect correspondences can be simultaneously identified while the homography is computed. Experiments show that the proposed approach can perform well even with the presence of a large number of outliers.
Optimization Method of Fusing Model Tree into Partial Least Squares
Directory of Open Access Journals (Sweden)
Yu Fang
2017-01-01
Full Text Available Partial Least Square (PLS can’t adapt to the characteristics of the data of many fields due to its own features multiple independent variables, multi-dependent variables and non-linear. However, Model Tree (MT has a good adaptability to nonlinear function, which is made up of many multiple linear segments. Based on this, a new method combining PLS and MT to analysis and predict the data is proposed, which build MT through the main ingredient and the explanatory variables(the dependent variable extracted from PLS, and extract residual information constantly to build Model Tree until well-pleased accuracy condition is satisfied. Using the data of the maxingshigan decoction of the monarch drug to treat the asthma or cough and two sample sets in the UCI Machine Learning Repository, the experimental results show that, the ability of explanation and predicting get improved in the new method.
Partial Least Squares tutorial for analyzing neuroimaging data
Directory of Open Access Journals (Sweden)
Patricia Van Roon
2014-09-01
Full Text Available Partial least squares (PLS has become a respected and meaningful soft modeling analysis technique that can be applied to very large datasets where the number of factors or variables is greater than the number of observations. Current biometric studies (e.g., eye movements, EKG, body movements, EEG are often of this nature. PLS eliminates the multiple linear regression issues of over-fitting data by finding a few underlying or latent variables (factors that account for most of the variation in the data. In real-world applications, where linear models do not always apply, PLS can model the non-linear relationship well. This tutorial introduces two PLS methods, PLS Correlation (PLSC and PLS Regression (PLSR and their applications in data analysis which are illustrated with neuroimaging examples. Both methods provide straightforward and comprehensible techniques for determining and modeling relationships between two multivariate data blocks by finding latent variables that best describes the relationships. In the examples, the PLSC will analyze the relationship between neuroimaging data such as Event-Related Potential (ERP amplitude averages from different locations on the scalp with their corresponding behavioural data. Using the same data, the PLSR will be used to model the relationship between neuroimaging and behavioural data. This model will be able to predict future behaviour solely from available neuroimaging data. To find latent variables, Singular Value Decomposition (SVD for PLSC and Non-linear Iterative PArtial Least Squares (NIPALS for PLSR are implemented in this tutorial. SVD decomposes the large data block into three manageable matrices containing a diagonal set of singular values, as well as left and right singular vectors. For PLSR, NIPALS algorithms are used because it provides amore precise estimation of the latent variables. Mathematica notebooks are provided for each PLS method with clearly labeled sections and subsections. The
Interference Energy Spectrum of the Infinite Square Well
Directory of Open Access Journals (Sweden)
Mordecai Waegell
2016-04-01
Full Text Available Certain superposition states of the 1-D infinite square well have transient zeros at locations other than the nodes of the eigenstates that comprise them. It is shown that if an infinite potential barrier is suddenly raised at some or all of these zeros, the well can be split into multiple adjacent infinite square wells without affecting the wavefunction. This effects a change of the energy eigenbasis of the state to a basis that does not commute with the original, and a subsequent measurement of the energy now reveals a completely different spectrum, which we call the interference energy spectrum of the state. This name is appropriate because the same splitting procedure applied at the stationary nodes of any eigenstate does not change the measurable energy of the state. Of particular interest, this procedure can result in measurable energies that are greater than the energy of the highest mode in the original superposition, raising questions about the conservation of energy akin to those that have been raised in the study of superoscillations. An analytic derivation is given for the interference spectrum of a given wavefunction Ψ ( x , t with N known zeros located at points s i = ( x i , t i . Numerical simulations were used to verify that a barrier can be rapidly raised at a zero of the wavefunction without significantly affecting it. The interpretation of this result with respect to the conservation of energy and the energy-time uncertainty relation is discussed, and the idea of alternate energy eigenbases is fleshed out. The question of whether or not a preferred discrete energy spectrum is an inherent feature of a particle’s quantum state is examined.
International Nuclear Information System (INIS)
Anon.
1980-01-01
An outline review notes recent work on total lymphoid irradiation (TLI) as a means of preparing patients for grafts and particularly for bone-marrow transplantation. T.L.I. has proved immunosuppressive in rats, mice, dogs, monkeys and baboons; when given before bone-marrow transplantation, engraftment took place without, or with delayed rejection or graft-versus-host disease. Work with mice has indicated that the thymus needs to be included within the irradiation field, since screening of the thymus reduced skin-graft survival from 50 to 18 days, though irradiation of the thymus alone has proved ineffective. A more lasting tolerance has been observed when T.L.I. is followed by an injection of donor bone marrow. 50% of mice treated in this way accepted allogenic skin grafts for more than 100 days, the animals proving to be stable chimeras with 50% of their peripheral blood lymphocytes being of donor origin. Experiments of a similar nature with dogs and baboons were not so successful. (U.K.)
Cook, Jason A; Shah, Keyur B; Quader, Mohammed A; Cooke, Richard H; Kasirajan, Vigneshwar; Rao, Kris K; Smallfield, Melissa C; Tchoukina, Inna; Tang, Daniel G
2015-12-01
The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.
Directory of Open Access Journals (Sweden)
Victor Aredo
2017-01-01
Full Text Available The aim of this study was to build a model to predict the beef marbling using HSI and Partial Least Squares Regression (PLSR. Totally 58 samples of longissmus dorsi muscle were scanned by a HSI system (400 - 1000 nm in reflectance mode, using 44 samples to build t he PLSR model and 14 samples to model validation. The Japanese Beef Marbling Standard (BMS was used as reference by 15 middle - trained judges for the samples evaluation. The scores were assigned as continuous values and varied from 1.2 to 5.3 BMS. The PLSR model showed a high correlation coefficient in the prediction (r = 0.95, a low Standard Error of Calibration (SEC of 0.2 BMS score, and a low Standard Error of Prediction (SEP of 0.3 BMS score.
Xu, Zheng; Wang, Sheng; Li, Yeqing; Zhu, Feiyun; Huang, Junzhou
2018-02-08
The most recent history of parallel Magnetic Resonance Imaging (pMRI) has in large part been devoted to finding ways to reduce acquisition time. While joint total variation (JTV) regularized model has been demonstrated as a powerful tool in increasing sampling speed for pMRI, however, the major bottleneck is the inefficiency of the optimization method. While all present state-of-the-art optimizations for the JTV model could only reach a sublinear convergence rate, in this paper, we squeeze the performance by proposing a linear-convergent optimization method for the JTV model. The proposed method is based on the Iterative Reweighted Least Squares algorithm. Due to the complexity of the tangled JTV objective, we design a novel preconditioner to further accelerate the proposed method. Extensive experiments demonstrate the superior performance of the proposed algorithm for pMRI regarding both accuracy and efficiency compared with state-of-the-art methods.
Tracking and Navigation of Future NASA Spacecraft with the Square Kilometer Array
Resch, G. M.; Jones, D. L.; Connally, M. J.; Weinreb, S.; Preston, R. A.
2001-12-01
The international radio astronomy community is currently working on the design of an array of small radio antennas with a total collecting area of one square kilometer - more than a hundred times that of the largest existing (100-m) steerable antennas. An array of this size would provide obvious advantages for high data rate telemetry reception and for spacecraft navigation. Among these advantages are a two-orders-of-magnitude increase in sensitivity for telemetry downlink, flexible sub-arraying to track multiple spacecraft simultaneously, increased reliability through the use of large numbers of identical array elements, very accurate real-time angular spacecraft tracking, and a dramatic reduction in cost per unit area. NASA missions in many disciplines, including planetary science, would benefit from this increased ground-based tracking capability. The science return from planned missions could be increased, and opportunities for less expensive or completely new kinds of missions would be created.
Fitting polynomial surfaces to triangular meshes with Voronoi Squared Distance Minimization
Nivoliers, Vincent; Yan, Dongming; Lé vy, Bruno L.
2011-01-01
This paper introduces Voronoi Squared Distance Minimization (VSDM), an algorithm that fits a surface to an input mesh. VSDM minimizes an objective function that corresponds to a Voronoi-based approximation of the overall squared distance function
Fitting polynomial surfaces to triangular meshes with Voronoi squared distance minimization
Nivoliers, Vincent; Yan, Dongming; Lé vy, Bruno L.
2012-01-01
This paper introduces Voronoi squared distance minimization (VSDM), an algorithm that fits a surface to an input mesh. VSDM minimizes an objective function that corresponds to a Voronoi-based approximation of the overall squared distance function
The Total Performance Scorecard: Case at UIN Syarif Hidayatullah Jakarta
Directory of Open Access Journals (Sweden)
Suhendra Suhendra
2016-10-01
Full Text Available This study aims to identify and analyse Total Human Resources Champions Management in relation to the Total Performance Scorecard. This study uses primary data by distributing questionnaires to the respondents, the 30 heads of department, 60 lecturers, 30 administrative staffs and 60 students of UIN Syarif Hidayatullah Jakarta. Partial Least Square (PLS had been used. Results from this study showed that all dimensions of Total Human Resources Champions Management (Human Resources Strategic Management, Infrastructure Management Firm, Management Employee Contribution, Management of Transformation and Changes, Spiritual and Campaign Management, Talent Management affected on Total Human Resources Champions Management, furthermore, Total Human Resources Champions Management has a significant positive effect on the Total Performance Scorecard course at UIN Syarif Hidayatullah Jakarta.DOI: 10.15408/etk.v15i2.3864
Filter Tuning Using the Chi-Squared Statistic
Lilly-Salkowski, Tyler
2017-01-01
The Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF) performs orbit determination (OD) for the Aqua and Aura satellites. Both satellites are located in low Earth orbit (LEO), and are part of what is considered the A-Train satellite constellation. Both spacecraft are currently in the science phase of their respective missions. The FDF has recently been tasked with delivering definitive covariance for each satellite.The main source of orbit determination used for these missions is the Orbit Determination Toolkit developed by Analytical Graphics Inc. (AGI). This software uses an Extended Kalman Filter (EKF) to estimate the states of both spacecraft. The filter incorporates force modelling, ground station and space network measurements to determine spacecraft states. It also generates a covariance at each measurement. This covariance can be useful for evaluating the overall performance of the tracking data measurements and the filter itself. An accurate covariance is also useful for covariance propagation which is utilized in collision avoidance operations. It is also valuable when attempting to determine if the current orbital solution will meet mission requirements in the future.This paper examines the use of the Chi-square statistic as a means of evaluating filter performance. The Chi-square statistic is calculated to determine the realism of a covariance based on the prediction accuracy and the covariance values at a given point in time. Once calculated, it is the distribution of this statistic that provides insight on the accuracy of the covariance.For the EKF to correctly calculate the covariance, error models associated with tracking data measurements must be accurately tuned. Over estimating or under estimating these error values can have detrimental effects on the overall filter performance. The filter incorporates ground station measurements, which can be tuned based on the accuracy of the individual ground stations. It also includes
Fast Dating Using Least-Squares Criteria and Algorithms.
To, Thu-Hien; Jung, Matthieu; Lycett, Samantha; Gascuel, Olivier
2016-01-01
Phylogenies provide a useful way to understand the evolutionary history of genetic samples, and data sets with more than a thousand taxa are becoming increasingly common, notably with viruses (e.g., human immunodeficiency virus (HIV)). Dating ancestral events is one of the first, essential goals with such data. However, current sophisticated probabilistic approaches struggle to handle data sets of this size. Here, we present very fast dating algorithms, based on a Gaussian model closely related to the Langley-Fitch molecular-clock model. We show that this model is robust to uncorrelated violations of the molecular clock. Our algorithms apply to serial data, where the tips of the tree have been sampled through times. They estimate the substitution rate and the dates of all ancestral nodes. When the input tree is unrooted, they can provide an estimate for the root position, thus representing a new, practical alternative to the standard rooting methods (e.g., midpoint). Our algorithms exploit the tree (recursive) structure of the problem at hand, and the close relationships between least-squares and linear algebra. We distinguish between an unconstrained setting and the case where the temporal precedence constraint (i.e., an ancestral node must be older that its daughter nodes) is accounted for. With rooted trees, the former is solved using linear algebra in linear computing time (i.e., proportional to the number of taxa), while the resolution of the latter, constrained setting, is based on an active-set method that runs in nearly linear time. With unrooted trees the computing time becomes (nearly) quadratic (i.e., proportional to the square of the number of taxa). In all cases, very large input trees (>10,000 taxa) can easily be processed and transformed into time-scaled trees. We compare these algorithms to standard methods (root-to-tip, r8s version of Langley-Fitch method, and BEAST). Using simulated data, we show that their estimation accuracy is similar to that
ON THE CONSTRUCTION OF LATIN SQUARES COUNTERBALANCED FOR IMMEDIATE SEQUENTIAL EFFECTS.
HOUSTON, TOM R., JR.
THIS REPORT IS ONE OF A SERIES DESCRIBING NEW DEVELOPMENTS IN THE AREA OF RESEARCH METHODOLOGY. IT DEALS WITH LATIN SQUARES AS A CONTROL FOR PROGRESSIVE AND ADJACENCY EFFECTS IN EXPERIMENTAL DESIGNS. THE HISTORY OF LATIN SQUARES IS ALSO REVIEWED, AND SEVERAL ALGORITHMS FOR THE CONSTRUCTION OF LATIN AND GRECO-LATIN SQUARES ARE PROPOSED. THE REPORT…
The study of the evolution of squares in 3 periods of Safavid, Qajar ...
African Journals Online (AJOL)
The study of the evolution of squares in 3 periods of Safavid, Qajar and Pahlavi with historical – evolutionary and form approach (Isfahan and Tehran styles) case study of Naqshe Jahan square in Isfahan, Ganjalikhan square in Kerman, Sabze Meydan and Toop.
40 CFR 761.306 - Sampling 1 meter square surfaces by random selection of halves.
2010-07-01
... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sampling 1 meter square surfaces by...(b)(3) § 761.306 Sampling 1 meter square surfaces by random selection of halves. (a) Divide each 1 meter square portion where it is necessary to collect a surface wipe test sample into two equal (or as...
An algorithm for total variation regularized photoacoustic imaging
DEFF Research Database (Denmark)
Dong, Yiqiu; Görner, Torsten; Kunis, Stefan
2014-01-01
Recovery of image data from photoacoustic measurements asks for the inversion of the spherical mean value operator. In contrast to direct inversion methods for specific geometries, we consider a semismooth Newton scheme to solve a total variation regularized least squares problem. During the iter......Recovery of image data from photoacoustic measurements asks for the inversion of the spherical mean value operator. In contrast to direct inversion methods for specific geometries, we consider a semismooth Newton scheme to solve a total variation regularized least squares problem. During...... the iteration, each matrix vector multiplication is realized in an efficient way using a recently proposed spectral discretization of the spherical mean value operator. All theoretical results are illustrated by numerical experiments....
Biermann, Carol
1988-01-01
Described is a study designed to introduce students to the behavior of common invertebrate animals, and to use of the chi-square statistical technique. Discusses activities with snails, pill bugs, and mealworms. Provides an abbreviated chi-square table and instructions for performing the experiments and statistical tests. (CW)
Peng, Jiangtao; Peng, Silong; Xie, Qiong; Wei, Jiping
2011-04-01
In order to eliminate the lower order polynomial interferences, a new quantitative calibration algorithm "Baseline Correction Combined Partial Least Squares (BCC-PLS)", which combines baseline correction and conventional PLS, is proposed. By embedding baseline correction constraints into PLS weights selection, the proposed calibration algorithm overcomes the uncertainty in baseline correction and can meet the requirement of on-line attenuated total reflectance Fourier transform infrared (ATR-FTIR) quantitative analysis. The effectiveness of the algorithm is evaluated by the analysis of glucose and marzipan ATR-FTIR spectra. BCC-PLS algorithm shows improved prediction performance over PLS. The root mean square error of cross-validation (RMSECV) on marzipan spectra for the prediction of the moisture is found to be 0.53%, w/w (range 7-19%). The sugar content is predicted with a RMSECV of 2.04%, w/w (range 33-68%). Copyright © 2011 Elsevier B.V. All rights reserved.
Brightness-normalized Partial Least Squares Regression for hyperspectral data
International Nuclear Information System (INIS)
Feilhauer, Hannes; Asner, Gregory P.; Martin, Roberta E.; Schmidtlein, Sebastian
2010-01-01
Developed in the field of chemometrics, Partial Least Squares Regression (PLSR) has become an established technique in vegetation remote sensing. PLSR was primarily designed for laboratory analysis of prepared material samples. Under field conditions in vegetation remote sensing, the performance of the technique may be negatively affected by differences in brightness due to amount and orientation of plant tissues in canopies or the observing conditions. To minimize these effects, we introduced brightness normalization to the PLSR approach and tested whether this modification improves the performance under changing canopy and observing conditions. This test was carried out using high-fidelity spectral data (400-2510 nm) to model observed leaf chemistry. The spectral data was combined with a canopy radiative transfer model to simulate effects of varying canopy structure and viewing geometry. Brightness normalization enhanced the performance of PLSR by dampening the effects of canopy shade, thus providing a significant improvement in predictions of leaf chemistry (up to 3.6% additional explained variance in validation) compared to conventional PLSR. Little improvement was made on effects due to variable leaf area index, while minor improvement (mostly not significant) was observed for effects of variable viewing geometry. In general, brightness normalization increased the stability of model fits and regression coefficients for all canopy scenarios. Brightness-normalized PLSR is thus a promising approach for application on airborne and space-based imaging spectrometer data.
Neutron diffraction determination of mean-square atomic displacements
International Nuclear Information System (INIS)
Tibballs, J.E.; Feteris, S.M.; Barnea, Z.
1981-01-01
Integrated intensities for Bragg reflection of neutrons from single crystals of the III-V compounds, InAs and GaSb, have been measured at room temperature. The data were collected at two wavelengths, 0.947 A and 1.241 A, in order to establish the adequacy of a correction for moderate to severe anisotropic extinction. Data were also obtained for InAs at four temperatures from 408 K to 933 K. Corrections for thermal diffuse scattering were applied. The results were analysed in the one-particle potential approximation with terms to fourth-order in the atomic displacements u = (u 1 , u 2 , u 3 ). At 296 K, the mean-square components were determined for In, 0.0116(2)A 2 and As, 0.0102 (1)A 2 ; for Ga, 0.0120(3)A 2 and Sb, 0.0107(3)A 2 . The third-order coefficients for InAs are comparable with those for Si and Ge, those for GaSb with those for zinc chalcogenides. Non-harmonic behaviour in InAs is observed below 400 K
Elastic Model Transitions Using Quadratic Inequality Constrained Least Squares
Orr, Jeb S.
2012-01-01
A technique is presented for initializing multiple discrete finite element model (FEM) mode sets for certain types of flight dynamics formulations that rely on superposition of orthogonal modes for modeling the elastic response. Such approaches are commonly used for modeling launch vehicle dynamics, and challenges arise due to the rapidly time-varying nature of the rigid-body and elastic characteristics. By way of an energy argument, a quadratic inequality constrained least squares (LSQI) algorithm is employed to e ect a smooth transition from one set of FEM eigenvectors to another with no requirement that the models be of similar dimension or that the eigenvectors be correlated in any particular way. The physically unrealistic and controversial method of eigenvector interpolation is completely avoided, and the discrete solution approximates that of the continuously varying system. The real-time computational burden is shown to be negligible due to convenient features of the solution method. Simulation results are presented, and applications to staging and other discontinuous mass changes are discussed
Superconducting gravity gradiometer and a test of inverse square law
International Nuclear Information System (INIS)
Moody, M.V.; Paik, H.J.
1989-01-01
The equivalence principle prohibits the distinction of gravity from acceleration by a local measurement. However, by making a differential measurement of acceleration over a baseline, platform accelerations can be cancelled and gravity gradients detected. In an in-line superconducting gravity gradiometer, this differencing is accomplished with two spring-mass accelerometers in which the proof masses are confined to motion in a single degree of freedom and are coupled together by superconducting circuits. Platform motions appear as common mode accelerations and are cancelled by adjusting the ratio of two persistent currents in the sensing circuit. The sensing circuit is connected to a commercial SQUID amplifier to sense changes in the persistent currents generated by differential accelerations, i.e., gravity gradients. A three-axis gravity gradiometer is formed by mounting six accelerometers on the faces of a precision cube, with the accelerometers on opposite faces of the cube forming one of three in-line gradiometers. A dedicated satellite mission for mapping the earth's gravity field is an important one. Additional scientific goals are a test of the inverse square law to a part in 10(exp 10) at 100 km, and a test of the Lense-Thirring effect by detecting the relativistic gravity magnetic terms in the gravity gradient tensor for the earth
Consistent Partial Least Squares Path Modeling via Regularization
Directory of Open Access Journals (Sweden)
Sunho Jung
2018-02-01
Full Text Available Partial least squares (PLS path modeling is a component-based structural equation modeling that has been adopted in social and psychological research due to its data-analytic capability and flexibility. A recent methodological advance is consistent PLS (PLSc, designed to produce consistent estimates of path coefficients in structural models involving common factors. In practice, however, PLSc may frequently encounter multicollinearity in part because it takes a strategy of estimating path coefficients based on consistent correlations among independent latent variables. PLSc has yet no remedy for this multicollinearity problem, which can cause loss of statistical power and accuracy in parameter estimation. Thus, a ridge type of regularization is incorporated into PLSc, creating a new technique called regularized PLSc. A comprehensive simulation study is conducted to evaluate the performance of regularized PLSc as compared to its non-regularized counterpart in terms of power and accuracy. The results show that our regularized PLSc is recommended for use when serious multicollinearity is present.
Magnitude Squared of Coherence to Detect Imaginary Movement
Directory of Open Access Journals (Sweden)
Sady Antônio Santos Filho
2009-01-01
Full Text Available This work investigates the Magnitude Squared of Coherence (MSC for detection of Event Related Potentials (ERPs related to left-hand index finger movement. Initially, ERP presence was examined in different brain areas. To accomplish that, 20 EEG channels were used, positioned according to the 10–20 international system. The grand average, resulting from 10 normal subjects showed, as expected, responses at frontal, central, and parietal areas, particularly evident at the central area (C3, C4, Cz. The MSC, applied to movement imagination related EEG signals, detected a consistent response in frequencies around 0.3–1 Hz (delta band, mainly at central area (C3, Cz, and C4. Ability differences in control imagination among subjects produced different detection performance. Some subjects needed up to 45 events for a detectable response, while for some others only 10 events proved sufficient. Some subjects also required two or three experimental sessions in order to achieve detectable responses. For one subject, response detection was not possible at all. However, due to brain plasticity, it is plausible to expect that training sessions (to practice movement imagination improve signal-noise ratio and lead to better detection using MSC. Results are sufficiently encouraging as to suggest further exploration of MSC for future BCI application.
IdeaSquare - finding and creating new ways to collaborate
CERN. Geneva
2014-01-01
IdeaSquare is a new pilot project meant to connect people inside and outside CERN to work together and helping the CERN-inspired innovations to create positive impact on society. We started our work last October with a five-month student project, Challenge Based Innovation (CBI) that has gathered some quite nice feedback along the way (http://cern.ch/go/wmM7), but is only one of our activities. Our big goal is scaling this collaboration up for different kinds of people all around the world to participate easily. We want to start by providing the student engineers, industrial designers and economists in the next round of CBI-course with better tools and services for working together and sharing their ideas. And in the long run, we want to create a scalable system that would allow a lot more people to work together and learn in similar constructive projects in the future. What are the tools at CERN we should use during the next round of CBI - Sharepoint, Vidyo, Owncloud, social.cern.ch... and something else? I...
BER analysis of regularized least squares for BPSK recovery
Ben Atitallah, Ismail; Thrampoulidis, Christos; Kammoun, Abla; Al-Naffouri, Tareq Y.; Hassibi, Babak; Alouini, Mohamed-Slim
2017-01-01
This paper investigates the problem of recovering an n-dimensional BPSK signal x
Square-integrable wave packets from the Volkov solutions
International Nuclear Information System (INIS)
Zakowicz, Stephan
2005-01-01
Rigorous mathematical proofs of some properties of the Volkov solutions are presented, which describe the motion of a relativistic charged Dirac particle in a classical, plane electromagnetic wave. The Volkov solutions are first rewritten in a convenient form, which clearly reveals some of the symmetries of the underlying Dirac equation. Assuming continuity and boundedness of the electromagnetic vector potential, it is shown how one may construct square-integrable wave packets from momentum distributions in the space C 0 ∞ (R 3 ) 4 . If, in addition, the vector potential is C 1 and the derivative is bounded, these wave packets decay in space faster than any polynomial and fulfill the Dirac equation. The mapping which takes momentum distributions into wave packets is shown to be isometric with respect to the L 2 (R 3 ) 4 norm and may therefore be continuously extended to a mapping from L 2 (R 3 ) 4 . For a momentum function in L 1 (R 3 ) 4 intersection L 2 (R 3 ) 4 , an integral representation of this extension is presented
RCS Leak Rate Calculation with High Order Least Squares Method
International Nuclear Information System (INIS)
Lee, Jeong Hun; Kang, Young Kyu; Kim, Yang Ki
2010-01-01
As a part of action items for Application of Leak before Break(LBB), RCS Leak Rate Calculation Program is upgraded in Kori unit 3 and 4. For real time monitoring of operators, periodic calculation is needed and corresponding noise reduction scheme is used. This kind of study was issued in Korea, so there have upgraded and used real time RCS Leak Rate Calculation Program in UCN unit 3 and 4 and YGN unit 1 and 2. For reduction of the noise in signals, Linear Regression Method was used in those programs. Linear Regression Method is powerful method for noise reduction. But the system is not static with some alternative flow paths and this makes mixed trend patterns of input signal values. In this condition, the trend of signal and average of Linear Regression are not entirely same pattern. In this study, high order Least squares Method is used to follow the trend of signal and the order of calculation is rearranged. The result of calculation makes reasonable trend and the procedure is physically consistence
Application of the Least Squares Method in Axisymmetric Biharmonic Problems
Directory of Open Access Journals (Sweden)
Vasyl Chekurin
2016-01-01
Full Text Available An approach for solving of the axisymmetric biharmonic boundary value problems for semi-infinite cylindrical domain was developed in the paper. On the lateral surface of the domain homogeneous Neumann boundary conditions are prescribed. On the remaining part of the domain’s boundary four different biharmonic boundary pieces of data are considered. To solve the formulated biharmonic problems the method of least squares on the boundary combined with the method of homogeneous solutions was used. That enabled reducing the problems to infinite systems of linear algebraic equations which can be solved with the use of reduction method. Convergence of the solution obtained with developed approach was studied numerically on some characteristic examples. The developed approach can be used particularly to solve axisymmetric elasticity problems for cylindrical bodies, the heights of which are equal to or exceed their diameters, when on their lateral surface normal and tangential tractions are prescribed and on the cylinder’s end faces various types of boundary conditions in stresses in displacements or mixed ones are given.
Square-Integrable Wave Packets from the Volkov Solutions
Zakowicz, S
2004-01-01
Rigorous mathematical proofs of some properties of the Volkov solutions are presented, which describe the motion of a relativistic charged Dirac particle in a classical, plane electromagnetic wave. The Volkov solutions are first rewritten in a convenient form, which clearly reveals some of the symmetries of the underlying Dirac equation. Assuming continuity and boundedness of the electromagnetic vector potential, it is shown how one may construct square-integrable wave packets from momentum distributions in the space $\\mathcal{C}^{\\infty}_0(\\mathbb{R}^3)^4$. If, in addition, the vector potential is $\\mathcal{C}^1$ and the derivative is bounded, these wave packets decay in space faster than any polynomial and fulfill the Dirac equation. The mapping which takes momentum distributions into wave packets is shown to be isometric with respect to the $L^2(\\mathbb{R}^3)^4$ norm and may therefore be continuously extended to a mapping from $L^2(\\mathbb{R}^3)^4$. For a momen! tum function in $L^1(\\mathbb{R}^3)^4 \\cap L^...
Short-range inverse-square law experiment in space
International Nuclear Information System (INIS)
Strayer, D.M.; Paik, H.J.; Moody, M.V.
2003-01-01
The objective of ISLES (inverse-square law experiment in space) is to perform a null test of Newton's law on the ISS with a resolution of one part in 10 5 at ranges from 100 mm to 1 mm. ISLES will be sensitive enough to detect axions with the strongest allowed coupling and to test the string-theory prediction with R>= 5 μm. To accomplish these goals on the rather noisy International Space Station, the experiment is set up to provide immunity from the vibrations and other common-mode accelerations. The measures to be applied for reducing the effects of disturbances will be described in this presentation. As designed, the experiment will be cooled to less than 2 K in NASA's low temperature facility the LTMPF, allowing superconducting magnetic levitation in microgravity to obtain very soft, low-loss suspension of the test masses. The low-damping magnetic levitation, combined with a low-noise SQUID, leads to extremely low intrinsic noise in the detector. To minimize Newtonian errors, ISLES employs a near-null source of gravity, a circular disk of large diameter-to-thickness ratio. Two test masses, also disk-shaped, are suspended on the two sides of the source mass at a distance of 100 μm to 1 mm. The signal is detected by a superconducting differential accelerometer, making a highly sensitive sensor of the gravity force generated by the source mass
Parametric Studies of Square Solar Sails Using Finite Element Analysis
Sleight, David W.; Muheim, Danniella M.
2004-01-01
Parametric studies are performed on two generic square solar sail designs to identify parameters of interest. The studies are performed on systems-level models of full-scale solar sails, and include geometric nonlinearity and inertia relief, and use a Newton-Raphson scheme to apply sail pre-tensioning and solar pressure. Computational strategies and difficulties encountered during the analyses are also addressed. The purpose of this paper is not to compare the benefits of one sail design over the other. Instead, the results of the parametric studies may be used to identify general response trends, and areas of potential nonlinear structural interactions for future studies. The effects of sail size, sail membrane pre-stress, sail membrane thickness, and boom stiffness on the sail membrane and boom deformations, boom loads, and vibration frequencies are studied. Over the range of parameters studied, the maximum sail deflection and boom deformations are a nonlinear function of the sail properties. In general, the vibration frequencies and modes are closely spaced. For some vibration mode shapes, local deformation patterns that dominate the response are identified. These localized patterns are attributed to the presence of negative stresses in the sail membrane that are artifacts of the assumption of ignoring the effects of wrinkling in the modeling process, and are not believed to be physically meaningful. Over the range of parameters studied, several regions of potential nonlinear modal interaction are identified.
Focusing properties of a square electrostatic rainbow lens
International Nuclear Information System (INIS)
Telečki, I.; Petrović, S.; Beličev, P.; Rađenović, B.; Balvanović, R.; Bojović, B.; Nešković, N.
2012-01-01
This paper is devoted to the focusing properties of a square electrostatic rainbow lens, which is a novel ion beam optical element. We consider the transmission of parallel and non-parallel proton beams of the initial kinetic energy of 10 keV through this lens. The potential of the electrodes of the lens is chosen to be 2 kV. The electrostatic potential and components of the electric field in the region of the lens are calculated using a three-dimensional finite element computer code. We investigate the spatial and angular distributions of protons propagating through the lens and in the drift space after it. It is confirmed that the evolutions of these distributions are determined by the evolutions of the corresponding rainbow lines, generated using the theory of crystal rainbows. The beam is separated into two components. One beam component, appearing as a beam core, is generated dominantly by the focused protons. Its boundary line in the transverse position plane can be very well approximated by a hypotrochoid. The other beam component is generated dominantly by the defocused protons. We present the focusing coefficient of the lens, the confining coefficients of the lens for the focused and defocused protons, the density of the beam core, the vertical or horizontal emittance of the beam core, and the brightness of the beam core.
Turbulence and secondary motions in square duct flow
Pirozzoli, Sergio; Modesti, Davide; Orlandi, Paolo; Grasso, Francesco
2017-11-01
We study turbulent flows in pressure-driven ducts with square cross-section through DNS up to Reτ 1050 . Numerical simulations are carried out over extremely long integration times to get adequate convergence of the flow statistics, and specifically high-fidelity representation of the secondary motions which arise. The intensity of the latter is found to be in the order of 1-2% of the bulk velocity, and unaffected by Reynolds number variations. The smallness of the mean convection terms in the streamwise vorticity equation points to a simple characterization of the secondary flows, which in the asymptotic high-Re regime are found to be approximated with good accuracy by eigenfunctions of the Laplace operator. Despite their effect of redistributing the wall shear stress along the duct perimeter, we find that secondary motions do not have large influence on the mean velocity field, which can be characterized with good accuracy as that resulting from the concurrent effect of four independent flat walls, each controlling a quarter of the flow domain. As a consequence, we find that parametrizations based on the hydraulic diameter concept, and modifications thereof, are successful in predicting the duct friction coefficient. This research was carried out using resources from PRACE EU Grants.
Classification of Hyperspectral Images Using Kernel Fully Constrained Least Squares
Directory of Open Access Journals (Sweden)
Jianjun Liu
2017-11-01
Full Text Available As a widely used classifier, sparse representation classification (SRC has shown its good performance for hyperspectral image classification. Recent works have highlighted that it is the collaborative representation mechanism under SRC that makes SRC a highly effective technique for classification purposes. If the dimensionality and the discrimination capacity of a test pixel is high, other norms (e.g., ℓ 2 -norm can be used to regularize the coding coefficients, except for the sparsity ℓ 1 -norm. In this paper, we show that in the kernel space the nonnegative constraint can also play the same role, and thus suggest the investigation of kernel fully constrained least squares (KFCLS for hyperspectral image classification. Furthermore, in order to improve the classification performance of KFCLS by incorporating spatial-spectral information, we investigate two kinds of spatial-spectral methods using two regularization strategies: (1 the coefficient-level regularization strategy, and (2 the class-level regularization strategy. Experimental results conducted on four real hyperspectral images demonstrate the effectiveness of the proposed KFCLS, and show which way to incorporate spatial-spectral information efficiently in the regularization framework.
Plasmon excitations in doped square-lattice atomic clusters
Wang, Yaxin; Yu, Ya-Bin
2017-12-01
Employing the tight-binding model, we theoretically study the properties of the plasmon excitations in doped square-lattice atomic clusters. The results show that the dopant atoms would blur the absorption spectra, and give rise to extra plasmon resonant peaks as reported in the literature; however, our calculated external-field induced oscillating charge density shows that no obvious evidences indicate the so-called local mode of plasmon appearing in two-dimensional-doped atomic clusters, but the dopants may change the symmetry of the charge distribution. Furthermore, we show that the disorder of the energy level due to dopant makes the absorption spectrum has a red- or blue-shift, which depends on the position of impurities; disorder of hopping due to dopant makes a blue- or red-shift, a larger (smaller) hopping gives a blue-shift (red-shift); and a larger (smaller) host-dopant and dopant-dopant intersite coulomb repulsion induces a blue-shift (red-shift).
Thermally induced magnetic relaxation in square artificial spin ice
Andersson, M. S.; Pappas, S. D.; Stopfel, H.; Östman, E.; Stein, A.; Nordblad, P.; Mathieu, R.; Hjörvarsson, B.; Kapaklis, V.
2016-11-01
The properties of natural and artificial assemblies of interacting elements, ranging from Quarks to Galaxies, are at the heart of Physics. The collective response and dynamics of such assemblies are dictated by the intrinsic dynamical properties of the building blocks, the nature of their interactions and topological constraints. Here we report on the relaxation dynamics of the magnetization of artificial assemblies of mesoscopic spins. In our model nano-magnetic system - square artificial spin ice - we are able to control the geometrical arrangement and interaction strength between the magnetically interacting building blocks by means of nano-lithography. Using time resolved magnetometry we show that the relaxation process can be described using the Kohlrausch law and that the extracted temperature dependent relaxation times of the assemblies follow the Vogel-Fulcher law. The results provide insight into the relaxation dynamics of mesoscopic nano-magnetic model systems, with adjustable energy and time scales, and demonstrates that these can serve as an ideal playground for the studies of collective dynamics and relaxations.
BER analysis of regularized least squares for BPSK recovery
Ben Atitallah, Ismail
2017-06-20
This paper investigates the problem of recovering an n-dimensional BPSK signal x
Bioethics in the public square: reflections on the how.
Campbell, Amy Tannery
2012-07-01
As bioethics gains more prominence in public policy debates, it is time to more fully reflect on the following: what is its role in the public square, and what limitations relate to and barriers impede its fulfilment of this role? I contend we should consider the how of bioethics (as a policy influencer) rather than simply focus on the who or what of bioethical enquiry. This is not to suggest considerations of latter categories are not important, only that too little attention has been paid to parallel or resulting policy involvement-involvement that will require specialised skills and knowledge that we can develop with a proactive (vs reactive) stance. Moreover, and equally critically, this how of public policy involvement will require more transparency regarding influences (eg, philosophical, ideological, cultural, socio-political) on what bioethicists bring to the table and what constituency base each represents-a humility as to the scope of one's role. In this vision, bioethics is not one single person or belief system for a policymaker to call to guide or give support to a position; rather, it offers tools-formed and utilised by a diverse disciplinary range of individuals-to help guide ethical analysis of biomedical endeavours, with the goal of infusion and diffusion of ethical enquiry and prioritisation in health policymaking, and greater humility among bioethicists who inform this discussion.
Standing wave brass-PZT square tubular ultrasonic motor.
Park, Soonho; He, Siyuan
2012-09-01
This paper reports a standing wave brass-PZT tubular ultrasonic motor. The motor is composed of a brass square tube with two teeth on each tube end. Four PZT plates are attached to the outside walls of the brass tube. The motor requires only one driving signal to excite vibration in a single bending mode to generate reciprocating diagonal trajectories of teeth on the brass tube ends, which drive the motor to rotate. Bi-directional rotation is achieved by exciting different pairs of PZT plates to switch the bending vibration direction. Through using the brass-PZT tube structure, the motor can take high magnitude vibration to achieve a high output power in comparison to PZT tube based ultrasonic motors. Prototypes are fabricated and tested. The dimension of the brass-PZT tube is 3.975mm×3.975mm×16mm. Measured performance is a no-load speed of >1000RPM, a stall torque of 370μNm and a maximum output power of 16 mW when a sinusoidal driving voltage of 50V is applied. The working frequencies of the motor are 46,050Hz (clockwise) and 46,200Hz (counter-clockwise). Copyright © 2012. Published by Elsevier B.V.
Repair for Congenital Macrostomia: Vermilion Square Flap Method
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Renuka Dhingra
2014-01-01
Full Text Available Transverse facial clefts (macrostomia are rare disorders that result when the embryonic mandibular and maxillary processes of the first branchial arch fail to fuse due to failure of mesodermal migration and merging to obliterate the embryonic grooves between the maxillary and mandibular processes to form the angle of the mouth at its normal anatomic position. Macrostomia may be seen alone or in association with other anomalies. It may be unilateral, extending along a line from the commissure to the tragus or bilateral. It is usually partial but rarely complete. Transverse facial clefts are more common in males and more common on the left side when unilateral. The goal of macrostomia reconstruction is to achieve functional, symmetrical, and accurate oral commissure with minimal scar. In this paper, we present a six-year-old girl with unilateral macrostomia with preauricular skin tags and malformation of pinna on ipsilateral side treated with vermillion-square flap method. The scar is placed at the upper lip. At two-month followup, the oral commissures are symmetric, the scars are inconspicuous, and the overall balance of facial contour and lip is excellent. We recommend this method for patients with mild to moderate macrostomia.
Vortex solitons at the interface separating square and hexagonal lattices
Energy Technology Data Exchange (ETDEWEB)
Jović Savić, Dragana, E-mail: jovic@ipb.ac.rs; Piper, Aleksandra; Žikić, Radomir; Timotijević, Dejan
2015-06-19
Vortex solitons at the interface separating two different photonic lattices – square and hexagonal – are demonstrated numerically. We consider the conditions for the existence of discrete vortex states at such interfaces and develop a concise picture of different scenarios of the vortex solutions behavior. Various vortices with different size and topological charges are considered, as well as various lattice interfaces. A novel type of discrete vortex surface solitons in a form of five-lobe solution is observed. Besides stable three-lobe and six-lobe discrete surface modes propagating for long distances, we observe various oscillatory vortex surface solitons, as well as dynamical instabilities of different kinds of solutions and study their angular momentum. Dynamical instabilities occur for higher values of the propagation constant, or at higher beam powers. - Highlights: • We demonstrate vortex solitons at the square–hexagonal photonic lattice interface. • A novel type of five-lobe surface vortex solitons is observed. • Different phase structures of surface solutions are studied. • Orbital angular momentum transfer of such solutions is investigated.
Analysis of secondary motions in square duct flow
Modesti, Davide; Pirozzoli, Sergio; Orlandi, Paolo; Grasso, Francesco
2018-04-01
We carry out direct numerical simulations (DNS) of square duct flow spanning the friction Reynolds number range {Re}τ * =150-1055, to study the nature and the role of secondary motions. We preliminarily find that secondary motions are not the mere result of the time averaging procedure, but rather they are present in the instantaneous flow realizations, corresponding to large eddies persistent in both space and time. Numerical experiments have also been carried out whereby the secondary motions are suppressed, hence allowing to quantifying their effect on the mean flow field. At sufficiently high Reynolds number, secondary motions are found to increase the friction coefficient by about 3%, hence proportionally to their relative strength with respect to the bulk flow. Simulations without secondary motions are found to yield larger deviations on the mean velocity profiles from the standard law-of-the-wall, revealing that secondary motions act as a self-regulating mechanism of turbulence whereby the effect of the corners is mitigated.
Least-squares fit of a linear combination of functions
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Niraj Upadhyay
2013-12-01
Full Text Available We propose that given a data-set $S=\\{(x_i,y_i/i=1,2,{\\dots}n\\}$ and real-valued functions $\\{f_\\alpha(x/\\alpha=1,2,{\\dots}m\\},$ the least-squares fit vector $A=\\{a_\\alpha\\}$ for $y=\\sum_\\alpha a_{\\alpha}f_\\alpha(x$ is $A = (F^TF^{-1}F^TY$ where $[F_{i\\alpha}]=[f_\\alpha(x_i].$ We test this formalism by deriving the algebraic expressions of the regression coefficients in $y = ax + b$ and in $y = ax^2 + bx + c.$ As a practical application, we successfully arrive at the coefficients in the semi-empirical mass formula of nuclear physics. The formalism is {\\it generic} - it has the potential of being applicable to any {\\it type} of $\\{x_i\\}$ as long as there exist appropriate $\\{f_\\alpha\\}.$ The method can be exploited with a CAS or an object-oriented language and is excellently suitable for parallel-processing.
Stock price estimation using ensemble Kalman Filter square root method
Karya, D. F.; Katias, P.; Herlambang, T.
2018-04-01
Shares are securities as the possession or equity evidence of an individual or corporation over an enterprise, especially public companies whose activity is stock trading. Investment in stocks trading is most likely to be the option of investors as stocks trading offers attractive profits. In determining a choice of safe investment in the stocks, the investors require a way of assessing the stock prices to buy so as to help optimize their profits. An effective method of analysis which will reduce the risk the investors may bear is by predicting or estimating the stock price. Estimation is carried out as a problem sometimes can be solved by using previous information or data related or relevant to the problem. The contribution of this paper is that the estimates of stock prices in high, low, and close categorycan be utilized as investors’ consideration for decision making in investment. In this paper, stock price estimation was made by using the Ensemble Kalman Filter Square Root method (EnKF-SR) and Ensemble Kalman Filter method (EnKF). The simulation results showed that the resulted estimation by applying EnKF method was more accurate than that by the EnKF-SR, with an estimation error of about 0.2 % by EnKF and an estimation error of 2.6 % by EnKF-SR.
Battery state-of-charge estimation using approximate least squares
Unterrieder, C.; Zhang, C.; Lunglmayr, M.; Priewasser, R.; Marsili, S.; Huemer, M.
2015-03-01
In recent years, much effort has been spent to extend the runtime of battery-powered electronic applications. In order to improve the utilization of the available cell capacity, high precision estimation approaches for battery-specific parameters are needed. In this work, an approximate least squares estimation scheme is proposed for the estimation of the battery state-of-charge (SoC). The SoC is determined based on the prediction of the battery's electromotive force. The proposed approach allows for an improved re-initialization of the Coulomb counting (CC) based SoC estimation method. Experimental results for an implementation of the estimation scheme on a fuel gauge system on chip are illustrated. Implementation details and design guidelines are presented. The performance of the presented concept is evaluated for realistic operating conditions (temperature effects, aging, standby current, etc.). For the considered test case of a GSM/UMTS load current pattern of a mobile phone, the proposed method is able to re-initialize the CC-method with a high accuracy, while state-of-the-art methods fail to perform a re-initialization.
The Heisenberg antiferromagnet on the square-kagomé lattice
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J. Richter
2009-01-01
Full Text Available We discuss the ground state, the low-lying excitations as well as high-field thermodynamics of the Heisenberg antiferromagnet on the two-dimensional square-kagomé lattice. This magnetic system belongs to the class of highly frustrated spin systems with an infinite non-trivial degeneracy of the classical ground state as it is also known for the Heisenberg antiferromagnet on the kagomé and on the star lattice. The quantum ground state of the spin-half system is a quantum paramagnet with a finite spin gap and with a large number of non-magnetic excitations within this gap. We also discuss the magnetization versus field curve that shows a plateaux as well as a macroscopic magnetization jump to saturation due to independent localized magnon states. These localized states are highly degenerate and lead to interesting features in the low-temperature thermodynamics at high magnetic fields such as an additional low-temperature peak in the specific heat and an enhanced magnetocaloric effect.
New edge-centered photonic square lattices with flat bands
Zhang, Da; Zhang, Yiqi; Zhong, Hua; Li, Changbiao; Zhang, Zhaoyang; Zhang, Yanpeng; Belić, Milivoj R.
2017-07-01
We report a new class of edge-centered photonic square lattices with multiple flat bands, and consider in detail two examples: the Lieb-5 and Lieb-7 lattices. In these lattices, there are 5 and 7 sites in the unit cell and in general, the number is restricted to odd integers. The number of flat bands m in the new Lieb lattices is related to the number of sites N in the unit cell by a simple formula m =(N - 1) / 2. The flat bands reported here are independent of the pseudomagnetic field. The properties of lattices with even and odd number of flat bands are different. We consider the localization of light in such Lieb lattices. If the input beam excites the flat-band mode, it will not diffract during propagation, owing to the strong mode localization. In the Lieb-7 lattice, the beam will also oscillate during propagation and still not diffract. The period of oscillation is determined by the energy difference between the two flat bands. This study provides a new platform for investigating light trapping, photonic topological insulators, and pseudospin-mediated vortex generation.
Linear field demagnetisation of artificial magnetic square ice
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Jason Phillip Morgan
2013-12-01
Full Text Available We have studied experimentally the states formed in artificial square ice nanomagnet systems following demagnetisation in a rotating in-plane applied magnetic field that reduces to zero in a manner that is linear in time. The final states are found to be controlled via the system's lattice constant, which determines the strength of the magnetostatic interactions between the elements, as well as the field ramping rate. We understand these effects as a requirement that the system undergoes a sufficiently large number of active rotations within the critical field window in which elements may be reversed, such that the interactions are allowed to locally exert their influence if the ground state is to be approached. On the other hand, if quenched disorder is too strong when compared to the interaction strength, any close approach to the ground state is impossible. These results show that it is not necessary for there to be any ac component to the field amplitude that is applied to the system during demagnetisation, which is the method almost exclusively employed in field protocols reported to date. Furthermore, by optimising the parameters of our linear demagnetisation protocol, the largest field-generated ground state domains yet reported are found.
Utilizing Minkowski functionals for image analysis: a marching square algorithm
International Nuclear Information System (INIS)
Mantz, Hubert; Jacobs, Karin; Mecke, Klaus
2008-01-01
Comparing noisy experimental image data with statistical models requires a quantitative analysis of grey-scale images beyond mean values and two-point correlations. A real-space image analysis technique is introduced for digitized grey-scale images, based on Minkowski functionals of thresholded patterns. A novel feature of this marching square algorithm is the use of weighted side lengths for pixels, so that boundary lengths are captured accurately. As examples to illustrate the technique we study surface topologies emerging during the dewetting process of thin films and analyse spinodal decomposition as well as turbulent patterns in chemical reaction–diffusion systems. The grey-scale value corresponds to the height of the film or to the concentration of chemicals, respectively. Comparison with analytic calculations in stochastic geometry models reveals a remarkable agreement of the examples with a Gaussian random field. Thus, a statistical test for non-Gaussian features in experimental data becomes possible with this image analysis technique—even for small image sizes. Implementations of the software used for the analysis are offered for download
3D plane-wave least-squares Kirchhoff migration
Wang, Xin
2014-08-05
A three dimensional least-squares Kirchhoff migration (LSM) is developed in the prestack plane-wave domain to increase the quality of migration images and the computational efficiency. Due to the limitation of current 3D marine acquisition geometries, a cylindrical-wave encoding is adopted for the narrow azimuth streamer data. To account for the mispositioning of reflectors due to errors in the velocity model, a regularized LSM is devised so that each plane-wave or cylindrical-wave gather gives rise to an individual migration image, and a regularization term is included to encourage the similarities between the migration images of similar encoding schemes. Both synthetic and field results show that: 1) plane-wave or cylindrical-wave encoding LSM can achieve both computational and IO saving, compared to shot-domain LSM, however, plane-wave LSM is still about 5 times more expensive than plane-wave migration; 2) the regularized LSM is more robust compared to LSM with one reflectivity model common for all the plane-wave or cylindrical-wave gathers.
Analysis of the Two-Regime Method on Square Meshes
Flegg, Mark B.
2014-01-01
The two-regime method (TRM) has been recently developed for optimizing stochastic reaction-diffusion simulations [M. Flegg, J. Chapman, and R. Erban, J. Roy. Soc. Interface, 9 (2012), pp. 859-868]. It is a multiscale (hybrid) algorithm which uses stochastic reaction-diffusion models with different levels of detail in different parts of the computational domain. The coupling condition on the interface between different modeling regimes of the TRM was previously derived for onedimensional models. In this paper, the TRM is generalized to higher dimensional reaction-diffusion systems. Coupling Brownian dynamics models with compartment-based models on regular (square) two-dimensional lattices is studied in detail. In this case, the interface between different modeling regimes contains either flat parts or right-angle corners. Both cases are studied in the paper. For flat interfaces, it is shown that the one-dimensional theory can be used along the line perpendicular to the TRM interface. In the direction tangential to the interface, two choices of the TRM parameters are presented. Their applicability depends on the compartment size and the time step used in the molecular-based regime. The two-dimensional generalization of the TRM is also discussed in the case of corners. © 2014 Society for Industrial and Applied Mathematics.
Antena Cerdas untuk Mitigasi Interferensi dengan Algoritma Least Mean Square
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Rahmad Hidayat
2017-06-01
Full Text Available Antena cerdas pada dasarnya merupakan susunan antena dengan kemampuan pemrosesan sinyal untuk mengirim/menerima informasi secara adaptif. Kemampuan ini harus terus didalami untuk dicarikan algoritma adaptif terbaik bagi kemampuan beamforming yang diinginkan. Tulisan ini bertujuan untuk memberikan kajian dan analisis pengaruh algoritma Least Mean Square (LMS pada pengaturan nulling beam pola radiasi susunan antena cerdas dalam perannya terhadap mitigasi interferensi. Simulasi kinerja beamformer untuk sebanyak 250 iterasi dilakukan dengan tool Matlab pada kanal AWGN (Additional White Noise Gaussian dan parameter simulasi diubah untuk membandingkan dua buah harga step size m pada algoritma LMS untuk beberapa jumlah elemen antena. Pengaruh nilai step size m, terlihat pada jumlah iterasi yang dilangsungkan sebelum error noise minimum diperoleh, dimana dengan naiknya nilai step size ini maka semakin mengurangi jumlah iterasi, rata-rata menjadi 60. Dari pola respon amplitudo setelah proses beamforming , posisi sinyal utama (0 dB tepat di sudut 30° dan dihasilkan 15 posisi nulling untuk 16 elemen antena. Sumber interferensi dihilangkan / ditutup dengan menempatkan ’nulls’ dalam arah sumber interferensi tersebut di posisi 60° dan -40° dengan masing-masing level diperoleh berkisar sebesar -115 dB
Square Turing patterns in reaction-diffusion systems with coupled layers
Energy Technology Data Exchange (ETDEWEB)
Li, Jing [State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871 (China); Wang, Hongli, E-mail: hlwang@pku.edu.cn, E-mail: qi@pku.edu.cn [State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871 (China); Center for Quantitative Biology, Peking University, Beijing 100871 (China); Ouyang, Qi, E-mail: hlwang@pku.edu.cn, E-mail: qi@pku.edu.cn [State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871 (China); Center for Quantitative Biology, Peking University, Beijing 100871 (China); The Peking-Tsinghua Center for Life Sciences, Beijing 100871 (China)
2014-06-15
Square Turing patterns are usually unstable in reaction-diffusion systems and are rarely observed in corresponding experiments and simulations. We report here an example of spontaneous formation of square Turing patterns with the Lengyel-Epstein model of two coupled layers. The squares are found to be a result of the resonance between two supercritical Turing modes with an appropriate ratio. Besides, the spatiotemporal resonance of Turing modes resembles to the mode-locking phenomenon. Analysis of the general amplitude equations for square patterns reveals that the fixed point corresponding to square Turing patterns is stationary when the parameters adopt appropriate values.
INVESTIGATION OF REPRESENTATIVE CHARACTERISTICS OF LUKIŠKIŲ SQUARE IN VILNIUS
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Gintautas TIŠKUS
2018-05-01
Full Text Available Representative squares are sites where ideological monuments or monuments are built, or squares to important state or municipal buildings. Representation square is a mark or sign system that is intended to provide some relevant information. This information may include events or actors that are important and desirable to commemorate, ideological - political motives that want to be given exclusive importance. In determining the structure of the area’s representative area, causal relationships with the represented object are identified. The original key information is the name. Subsequently, the type of object represented – an event or personality, a connection to the square, the importance of the mark on the square (dominant, noticeable or invisible, and the interaction between the label and the environment are determined. After examining the structure of the square of the square and writing the values in the matrix, we can determine the representation level of the square. In the representation square we can name the square, for which the context of the environment and the level of representational marks for the purpose of the square have a decisive or significant influence.
He, Qiaolin; Glowinski, Roland; Wang, Xiao Ping
2011-01-01
element space approximation with a time discretization by operator-splitting. To solve the Cahn-Hilliard part of the problem, we use a least-squares/conjugate gradient method. We also show that the scheme has the total energy decaying in time property
Child- and elder-friendly urban public places in Fatahillah Square Historical District
Srinaga, F.; LKatoppo, M.; Hidayat, J.
2018-03-01
Fatahillah square as an important historical urban square in Jakarta has problems in eye level area integrative processing. Visitors cannot enjoy their time while in the square regarding their visuals, feelings, space, and bodies comfort. These also lead to other problems in which the square is lack of friendly and convenient places for children, the elderly and also the disabled, especially people with limited moving space. The research will attempt in proposing design inception for the Fatahillah Square that is using inclusive user-centered design approach, while in the same time incorporate theoretical studies of children and elderly-design considerations. The first stage of this research was building inclusive design parameter; begin with a context-led research which assesses the quality of Fatahillah square through three basic components of urban space: hardware, software and orgware. The second stage of this research is to propose inclusive design inception for the Fatahillah square.
Directory of Open Access Journals (Sweden)
Andrew Jaya Nazar
2017-01-01
Full Text Available Instalasi saluran udara tidak hanya berupa pipa lurus, tetapi juga terdapat fitting/aksesoris perpipaan misalnya elbow 90o dan damper. Aksesoris perpipaan ini berfungsi agar saluran udara dapat terpasang sesuai dengan kebutuhan. Namun, penggunaan aksesoris perpipaan ini menyebabkan bertambahnya pressure drop akibat adanya friction loss dan separation loss. Pemasangan guide vane pada elbow 90o diharapkan dapat mengurangi pressure drop karena dapat mengurangi terjadinya secondary flow, namun hal ini dapat menambah kerugian akibat gaya gesek. Saat ini penghematan energi menjadi sorotan terutama dalam dunia industri. Penurunan pressure drop pada belokan perpipaan sangat diharapkan, agar dapat menghemat energi lebih. Untuk itu perlu dilakukan usaha agar dapat menurunkan pressure drop yang terjadi. Penelitian ini dilakukan secara eksperimen dengan benda uji saluran udara yang terdiri dari: upstream duct (straight duct, square elbow 90o dengan r/Dh=1,5 dan dilengkapi double guide vane, damper, downstream duct (straight duct, dan induced fan. Pengukuran parameter yang dibutuhkan dilakukan dengan menggunakan: pitot tube, inclined manometer, pressure tranducer. Dari eksperimen ini diperoleh bahwa profil kecepatan pada masing-masing variasi sudut bukaan damper sudah mendekati keadaan recovery aliran pada akhir section baik dari bidang vertikal maupun horizontal. Pressure drop yang terjadi semakin naik seiring dengan bertambahnya nilai bilangan Reynolds dan sudut bukaan damper. Nilai konstanta damper semakin naik dari bukaan sudut 0o hingga 30o.
Problem solving stages in the five square problem
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Anna eFedor
2015-08-01
Full Text Available According to the restructuring hypothesis, insight problem solving typically progresses through consecutive stages of search, impasse, insight and search again for someone, who solves the task. The order of these stages was determined through self-reports of problem solvers and has never been verified behaviourally. We asked whether individual analysis of problem solving attempts of participants revealed the same order of problem solving stages as defined by the theory and whether their subjective feelings corresponded to the problem solving stages they were in. 101 participants tried to solve the Five-Square problem in an online task, while we recorded the time and trajectory of their stick movements. After the task they were asked about their feelings related to insight and 67 of them also had the possibility of reporting impasse while working on the task. We have found that 49% (19 out of 39 of the solvers and 13% (8 out of 62 of the non-solvers followed the classic four-stage model of insight. The rest of the participants had more complex sequences of problem solving stages, with search and impasse recurring several times. This means that the classic four-stage model must be extended to explain variability on the individual level. We provide a model that can generate all sequences found. Solvers reported insight more often than non-solvers and non-solvers reported impasse more often than solvers, as expected; but participants did not report impasse more often during behaviourally defined impasse stages than during other stages. This shows that impasse reports might be unreliable indicators of impasse. Our study highlights the importance of individual analysis of problem solving behaviour to verify insight theory.
Problem solving stages in the five square problem.
Fedor, Anna; Szathmáry, Eörs; Öllinger, Michael
2015-01-01
According to the restructuring hypothesis, insight problem solving typically progresses through consecutive stages of search, impasse, insight, and search again for someone, who solves the task. The order of these stages was determined through self-reports of problem solvers and has never been verified behaviorally. We asked whether individual analysis of problem solving attempts of participants revealed the same order of problem solving stages as defined by the theory and whether their subjective feelings corresponded to the problem solving stages they were in. Our participants tried to solve the Five-Square problem in an online task, while we recorded the time and trajectory of their stick movements. After the task they were asked about their feelings related to insight and some of them also had the possibility of reporting impasse while working on the task. We found that the majority of participants did not follow the classic four-stage model of insight, but had more complex sequences of problem solving stages, with search and impasse recurring several times. This means that the classic four-stage model is not sufficient to describe variability on the individual level. We revised the classic model and we provide a new model that can generate all sequences found. Solvers reported insight more often than non-solvers and non-solvers reported impasse more often than solvers, as expected; but participants did not report impasse more often during behaviorally defined impasse stages than during other stages. This shows that impasse reports might be unreliable indicators of impasse. Our study highlights the importance of individual analysis of problem solving behavior to verify insight theory.
Finding A Minimally Informative Dirichlet Prior Using Least Squares
International Nuclear Information System (INIS)
Kelly, Dana
2011-01-01
In a Bayesian framework, the Dirichlet distribution is the conjugate distribution to the multinomial likelihood function, and so the analyst is required to develop a Dirichlet prior that incorporates available information. However, as it is a multiparameter distribution, choosing the Dirichlet parameters is less straightforward than choosing a prior distribution for a single parameter, such as p in the binomial distribution. In particular, one may wish to incorporate limited information into the prior, resulting in a minimally informative prior distribution that is responsive to updates with sparse data. In the case of binomial p or Poisson λ, the principle of maximum entropy can be employed to obtain a so-called constrained noninformative prior. However, even in the case of p, such a distribution cannot be written down in the form of a standard distribution (e.g., beta, gamma), and so a beta distribution is used as an approximation in the case of p. In the case of the multinomial model with parametric constraints, the approach of maximum entropy does not appear tractable. This paper presents an alternative approach, based on constrained minimization of a least-squares objective function, which leads to a minimally informative Dirichlet prior distribution. The alpha-factor model for common-cause failure, which is widely used in the United States, is the motivation for this approach, and is used to illustrate the method. In this approach to modeling common-cause failure, the alpha-factors, which are the parameters in the underlying multinomial model for common-cause failure, must be estimated from data that are often quite sparse, because common-cause failures tend to be rare, especially failures of more than two or three components, and so a prior distribution that is responsive to updates with sparse data is needed.
Yield surfaces for perforated plates with square arrays of holes
International Nuclear Information System (INIS)
Bhattacharya, A.; Venkat Raj, V.
2004-01-01
A symmetric model of a perforated plate containing a 3x3 array of circular holes, arranged in a square pattern, was chosen and elastoplastic finite element analyses were carried out to determine the limit stresses for both pitch and diagonal directions of loading, for different values of biaxiality ratios. Plane stress conditions were assumed and the Tresca and von Mises yield criteria were employed to obtain two different sets of results. Yield surfaces were constructed and 'general cut-out factors' were determined for four different ligament efficiencies. The FEM results obtained by the authors using the Tresca and von Mises yield criteria were compared with the corresponding results of [J. Pressure Vessel Technol. Trans. ASME (1975) 146-154] and [J. Pressure Vessel Technol. Trans. ASME (1997) 122-126], respectively. The results based on the Tresca yield criterion obtained by the present authors and those in [J. Pressure Vessel Technol. Trans. ASME (1975) 146-154] were found to agree well with each other. In the case of the von Mises yield criterion, the agreement with [J. Pressure Vessel Technol. Trans. ASME 122-126] is generally good. The estimates based on the Tresca yield criterion are seen to result in lower values of limit stresses and cut-out factors as compared to those based on the von Mises yield criterion. The difference is attributed to the yield criterion and the flow rule chosen for the analysis. The shape as well as the size of the yield surface was found to depend on the ligament efficiency
Finding a minimally informative Dirichlet prior distribution using least squares
International Nuclear Information System (INIS)
Kelly, Dana; Atwood, Corwin
2011-01-01
In a Bayesian framework, the Dirichlet distribution is the conjugate distribution to the multinomial likelihood function, and so the analyst is required to develop a Dirichlet prior that incorporates available information. However, as it is a multiparameter distribution, choosing the Dirichlet parameters is less straightforward than choosing a prior distribution for a single parameter, such as p in the binomial distribution. In particular, one may wish to incorporate limited information into the prior, resulting in a minimally informative prior distribution that is responsive to updates with sparse data. In the case of binomial p or Poisson λ, the principle of maximum entropy can be employed to obtain a so-called constrained noninformative prior. However, even in the case of p, such a distribution cannot be written down in the form of a standard distribution (e.g., beta, gamma), and so a beta distribution is used as an approximation in the case of p. In the case of the multinomial model with parametric constraints, the approach of maximum entropy does not appear tractable. This paper presents an alternative approach, based on constrained minimization of a least-squares objective function, which leads to a minimally informative Dirichlet prior distribution. The alpha-factor model for common-cause failure, which is widely used in the United States, is the motivation for this approach, and is used to illustrate the method. In this approach to modeling common-cause failure, the alpha-factors, which are the parameters in the underlying multinomial model for common-cause failure, must be estimated from data that are often quite sparse, because common-cause failures tend to be rare, especially failures of more than two or three components, and so a prior distribution that is responsive to updates with sparse data is needed.
Finding a Minimally Informative Dirichlet Prior Distribution Using Least Squares
International Nuclear Information System (INIS)
Kelly, Dana; Atwood, Corwin
2011-01-01
In a Bayesian framework, the Dirichlet distribution is the conjugate distribution to the multinomial likelihood function, and so the analyst is required to develop a Dirichlet prior that incorporates available information. However, as it is a multiparameter distribution, choosing the Dirichlet parameters is less straight-forward than choosing a prior distribution for a single parameter, such as p in the binomial distribution. In particular, one may wish to incorporate limited information into the prior, resulting in a minimally informative prior distribution that is responsive to updates with sparse data. In the case of binomial p or Poisson, the principle of maximum entropy can be employed to obtain a so-called constrained noninformative prior. However, even in the case of p, such a distribution cannot be written down in closed form, and so an approximate beta distribution is used in the case of p. In the case of the multinomial model with parametric constraints, the approach of maximum entropy does not appear tractable. This paper presents an alternative approach, based on constrained minimization of a least-squares objective function, which leads to a minimally informative Dirichlet prior distribution. The alpha-factor model for common-cause failure, which is widely used in the United States, is the motivation for this approach, and is used to illustrate the method. In this approach to modeling common-cause failure, the alpha-factors, which are the parameters in the underlying multinomial aleatory model for common-cause failure, must be estimated from data that is often quite sparse, because common-cause failures tend to be rare, especially failures of more than two or three components, and so a prior distribution that is responsive to updates with sparse data is needed.
Polynomial fuzzy observer designs: a sum-of-squares approach.
Tanaka, Kazuo; Ohtake, Hiroshi; Seo, Toshiaki; Tanaka, Motoyasu; Wang, Hua O
2012-10-01
This paper presents a sum-of-squares (SOS) approach to polynomial fuzzy observer designs for three classes of polynomial fuzzy systems. The proposed SOS-based framework provides a number of innovations and improvements over the existing linear matrix inequality (LMI)-based approaches to Takagi-Sugeno (T-S) fuzzy controller and observer designs. First, we briefly summarize previous results with respect to a polynomial fuzzy system that is a more general representation of the well-known T-S fuzzy system. Next, we propose polynomial fuzzy observers to estimate states in three classes of polynomial fuzzy systems and derive SOS conditions to design polynomial fuzzy controllers and observers. A remarkable feature of the SOS design conditions for the first two classes (Classes I and II) is that they realize the so-called separation principle, i.e., the polynomial fuzzy controller and observer for each class can be separately designed without lack of guaranteeing the stability of the overall control system in addition to converging state-estimation error (via the observer) to zero. Although, for the last class (Class III), the separation principle does not hold, we propose an algorithm to design polynomial fuzzy controller and observer satisfying the stability of the overall control system in addition to converging state-estimation error (via the observer) to zero. All the design conditions in the proposed approach can be represented in terms of SOS and are symbolically and numerically solved via the recently developed SOSTOOLS and a semidefinite-program solver, respectively. To illustrate the validity and applicability of the proposed approach, three design examples are provided. The examples demonstrate the advantages of the SOS-based approaches for the existing LMI approaches to T-S fuzzy observer designs.
Observation management challenges of the Square Kilometre Array
Bridger, Alan; Williams, Stewart J.; Nicol, Mark; Klaassen, Pamela; Thompson, Roger S.; Knapic, Cristina; Jerse, Giovanna; Orlati, Andrea; Messina, Marco; Valame, Snehal
2016-07-01
The Square Kilometre Array (SKA) will be the world's most advanced radio telescope, designed to explore some of the biggest questions in astronomy today, such as the epoch of re-ionization, the nature of gravity and the origins of cosmic magnetism. SKA1, the first phase of SKA construction, is currently being designed by a large team of experts world-wide. SKA1 comprises two telescopes: a 200-element dish interferometer in South Africa and a 130000-element dipole antenna aperture array in Australia. To enable the ground-breaking science of the SKA an advanced Observation Management system is required to support both the needs of the astronomical community users and the SKA Observatory staff. This system will ensure that the SKA realises its scientiffc aims and achieves optimal scientific throughput. This paper provides an overview of the design of the system that will accept proposals from SKA users, and result in the execution of the scripts that will obtain science data, taking in the stages of detailed preparation, planning and scheduling of the observations and onwards tracking. It describes the unique challenges of the differing requirements of two telescopes, one of which is very much a software telescope, including the need to schedule the data processing as well as the acquisition, and to react to both internally and externally discovered transient events. The scheduling of multiple parallel sub-array use is covered, along with the need to handle commensal observing - using the same data stream to satisfy the science goals of more than one project simultaneously. An international team from academia and industry, drawing on expertise and experience from previous telescope projects, the virtual observatory and comparable problems in industry, has been assembled to design the solution to this challenging but exciting problem.
Passive shimming of a superconducting magnet using the L1-norm regularized least square algorithm.
Kong, Xia; Zhu, Minhua; Xia, Ling; Wang, Qiuliang; Li, Yi; Zhu, Xuchen; Liu, Feng; Crozier, Stuart
2016-02-01
The uniformity of the static magnetic field B0 is of prime importance for an MRI system. The passive shimming technique is usually applied to improve the uniformity of the static field by optimizing the layout of a series of steel shims. The steel pieces are fixed in the drawers in the inner bore of the superconducting magnet, and produce a magnetizing field in the imaging region to compensate for the inhomogeneity of the B0 field. In practice, the total mass of steel used for shimming should be minimized, in addition to the field uniformity requirement. This is because the presence of steel shims may introduce a thermal stability problem. The passive shimming procedure is typically realized using the linear programming (LP) method. The LP approach however, is generally slow and also has difficulty balancing the field quality and the total amount of steel for shimming. In this paper, we have developed a new algorithm that is better able to balance the dual constraints of field uniformity and the total mass of the shims. The least square method is used to minimize the magnetic field inhomogeneity over the imaging surface with the total mass of steel being controlled by an L1-norm based constraint. The proposed algorithm has been tested with practical field data, and the results show that, with similar computational cost and mass of shim material, the new algorithm achieves superior field uniformity (43% better for the test case) compared with the conventional linear programming approach. Copyright © 2016 Elsevier Inc. All rights reserved.
Comparison of ileal and total tract nutrient digestibility of dry dog foods
Hendriks, W.H.; Thomas, G.; Bosch, G.; Fahey, G.C.
2013-01-01
The apparent total tract and ileal digestibility assays to measure AA absorption in commercial canine diets were compared in the present study. Five ileal cannulated dogs were fed 5 commercial dry canine foods selected to contain 19 to 30% CP in a 5 × 5 Latin square design. Ileal and total tract
Samuel Alexander Kinnier Wilson. Wilson's disease, Queen Square and neurology.
Broussolle, E; Trocello, J-M; Woimant, F; Lachaux, A; Quinn, N
2013-12-01
This historical article describes the life and work of the British physician Samuel Alexander Kinnier Wilson (1878-1937), who was one of the world's greatest neurologists of the first half of the 20th century. Early in his career, Wilson spent one year in Paris in 1903 where he learned from Pierre-Marie at Bicêtre Hospital. He subsequently retained uninterrupted links with French neurology. He also visited in Leipzig the German anatomist Paul Flechsig. In 1904, Wilson returned to London, where he worked for the rest of his life at the National Hospital for the Paralysed and Epileptic (later the National Hospital for Nervous Diseases, and today the National Hospital for Neurology and Neurosurgery) in Queen Square, and also at Kings' College Hospital. He wrote on 'the old motor system and the new', on disorders of motility and muscle tone, on the epilepsies, on aphasia, apraxia, tics, and pathologic laughing and crying, and most importantly on Wilson's disease. The other objective of our paper is to commemorate the centenary of Wilson's most important work published in 1912 in Brain, and also in Revue Neurologique, on an illness newly recognized and characterized by him entitled "Progressive lenticular degeneration, a familial nervous disease associated with liver cirrhosis". He analyzed 12 clinical cases, four of whom he followed himself, but also four cases previously published by others and a further two that he considered in retrospect had the same disease as he was describing. The pathological profile combined necrotic damage in the lenticular nuclei of the brain and hepatic cirrhosis. This major original work is summarized and discussed in the present paper. Wilson not only delineated what was later called hepato-lenticular degeneration and Wilson's disease, but also introduced for the first time the terms extrapyramidal syndrome and extrapyramidal system, stressing the role of the basal ganglia in motility. The present historical work emphasizes the special
Comparing implementations of penalized weighted least-squares sinogram restoration
International Nuclear Information System (INIS)
Forthmann, Peter; Koehler, Thomas; Defrise, Michel; La Riviere, Patrick
2010-01-01
Purpose: A CT scanner measures the energy that is deposited in each channel of a detector array by x rays that have been partially absorbed on their way through the object. The measurement process is complex and quantitative measurements are always and inevitably associated with errors, so CT data must be preprocessed prior to reconstruction. In recent years, the authors have formulated CT sinogram preprocessing as a statistical restoration problem in which the goal is to obtain the best estimate of the line integrals needed for reconstruction from the set of noisy, degraded measurements. The authors have explored both penalized Poisson likelihood (PL) and penalized weighted least-squares (PWLS) objective functions. At low doses, the authors found that the PL approach outperforms PWLS in terms of resolution-noise tradeoffs, but at standard doses they perform similarly. The PWLS objective function, being quadratic, is more amenable to computational acceleration than the PL objective. In this work, the authors develop and compare two different methods for implementing PWLS sinogram restoration with the hope of improving computational performance relative to PL in the standard-dose regime. Sinogram restoration is still significant in the standard-dose regime since it can still outperform standard approaches and it allows for correction of effects that are not usually modeled in standard CT preprocessing. Methods: The authors have explored and compared two implementation strategies for PWLS sinogram restoration: (1) A direct matrix-inversion strategy based on the closed-form solution to the PWLS optimization problem and (2) an iterative approach based on the conjugate-gradient algorithm. Obtaining optimal performance from each strategy required modifying the naive off-the-shelf implementations of the algorithms to exploit the particular symmetry and sparseness of the sinogram-restoration problem. For the closed-form approach, the authors subdivided the large matrix
Directory of Open Access Journals (Sweden)
Lurdes Borges Silva
2017-01-01
Full Text Available Tree density is an important parameter affecting ecosystems functions and management decisions, while tree distribution patterns affect sampling design. Pittosporum undulatum stands in the Azores are being targeted with a biomass valorization program, for which efficient tree density estimators are required. We compared T-Square sampling, Point Centered Quarter Method (PCQM, and N-tree sampling with benchmark quadrat (QD sampling in six 900 m2 plots established at P. undulatum stands in São Miguel Island. A total of 15 estimators were tested using a data resampling approach. The estimated density range (344–5056 trees/ha was found to agree with previous studies using PCQM only. Although with a tendency to underestimate tree density (in comparison with QD, overall, T-Square sampling appeared to be the most accurate and precise method, followed by PCQM. Tree distribution pattern was found to be slightly aggregated in 4 of the 6 stands. Considering (1 the low level of bias and high precision, (2 the consistency among three estimators, (3 the possibility of use with aggregated patterns, and (4 the possibility of obtaining a larger number of independent tree parameter estimates, we recommend the use of T-Square sampling in P. undulatum stands within the framework of a biomass valorization program.
Energy Technology Data Exchange (ETDEWEB)
Jhung, Myung Ho [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Jeong, Kyeong Hoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2015-06-15
In this study, the natural frequencies of the perforated square plate with a square penetration pattern are obtained as a function of ligament efficiency using the commercial finite-element analysis code ANSYS. In addition, they are used to extract the effective modulus of elasticity under an assumption of a constant Poisson's ratio. The effective modulus of elasticity of the fully perforated square plate is applied to the modal analysis of a partially perforated square plate using a homogeneous finite-element analysis model. The natural frequencies and the corresponding mode shapes of the homogeneous model are compared with the results of the detailed finite-element analysis model of the partially perforated square plate to check the validity of the effective modulus of elasticity. In addition, the theoretical method to calculate the natural frequencies of a partially perforated square plate with fixed edges is suggested according to the Rayleigh-Ritz method.
Directory of Open Access Journals (Sweden)
Myung Jo Jhung
2015-06-01
Full Text Available In this study, the natural frequencies of the perforated square plate with a square penetration pattern are obtained as a function of ligament efficiency using the commercial finite-element analysis code ANSYS. In addition, they are used to extract the effective modulus of elasticity under an assumption of a constant Poisson's ratio. The effective modulus of elasticity of the fully perforated square plate is applied to the modal analysis of a partially perforated square plate using a homogeneous finite-element analysis model. The natural frequencies and the corresponding mode shapes of the homogeneous model are compared with the results of the detailed finite-element analysis model of the partially perforated square plate to check the validity of the effective modulus of elasticity. In addition, the theoretical method to calculate the natural frequencies of a partially perforated square plate with fixed edges is suggested according to the Rayleigh–Ritz method.
International Nuclear Information System (INIS)
Benedetto, A; Magazù, S; Migliardo, F; Mondelli, C; Gonzalez, M A
2012-01-01
In the present contribution, a procedure for molecular motion characterization based on the evaluation of the Mean Square Displacement (MSD), through the Self-Distribution Function (SDF), is presented. It is shown how MSD, which represents an important observable for the characterization of dynamical properties, can be decomposed into different partial contributions associated to system dynamical processes within a specific spatial scale. It is also shown how the SDF procedure allows us to evaluate both total MSD and partial MSDs through total and partial SDFs. As a result, total MSD is the weighed sum of partial MSDs in which the weights are obtained by the fitting procedure of measured Elastic Incoherent Neutron Scattering (EINS) intensity. We apply SDF procedure to data collected,by IN13, IN10 and IN4 spectrometers (Institute Laue Langevin), on aqueous mixtures of two homologous disaccharides (sucrose and trehalose) and on dry and hydrated (H 2 O and D 2 O) lysozyme with and without disaccharides. It emerges that the hydrogen bond imposed network of the water-trehalose mixture appears to be stronger with respect to that of the water-sucrose mixture. This result can justify the higher bioprotectant effectiveness of trehalose. Furthermore, it emerges that partial MSDs of sucrose and trehalose are equivalent in the low Q domain (0÷1.7) Å −1 whereas they are different in the high Q domain (1.7÷4) Å −1 . This suggests that the higher structure sensitivity of sucrose should be related to the small spatial observation windows. Moreover, the role of the instrumental resolution in EINS is considered. The nature of the dynamical transition is highlighted and it is shown that it occurs when the system relaxation time becomes shorter than the instrumental energy time. Finally, the bioprotectants effect on protein dynamics and the amplitude of vibrations in lysozyme are presented.
Plowes, Nicola J.R; Adams, Eldridge S
2005-01-01
Lanchester's models of attrition describe casualty rates during battles between groups as functions of the numbers of individuals and their fighting abilities. Originally developed to describe human warfare, Lanchester's square law has been hypothesized to apply broadly to social animals as well, with important consequences for their aggressive behaviour and social structure. According to the square law, the fighting ability of a group is proportional to the square of the number of individual...
A program for making completely balanced Latin Square designs employing a systemic method
Kim, Beob G; Kim, Taemin
2010-01-01
Animal scientists employ Latin square designs to reduce the required number of animals for detecting statistical differences in animal experiments. Randomization procedures do not balance residual effects that possibly exist in Latin square experiments. A spreadsheet-based program is available for making Latin square designs balanced for the first-order residual effects. The balance of remote residual effects may also be very important to consider when a relatively long latent period exists a...