Technology Transfer Automated Retrieval System (TEKTRAN)
Increasing availability of genomic data and sophistication of analytical methodology in fungi has elevated the need for functional genomics tools in these organisms. Gene deletion is a critical tool for functional analysis. The targeted deletion of genes requires both a suitable method for the trans...
Transformative Mixed Methods Research
ERIC Educational Resources Information Center
Mertens, Donna M.
2010-01-01
Paradigms serve as metaphysical frameworks that guide researchers in the identification and clarification of their beliefs with regard to ethics, reality, knowledge, and methodology. The transformative paradigm is explained and illustrated as a framework for researchers who place a priority on social justice and the furtherance of human rights.…
Fourier transform interferometer alignment method.
Goldberg, Kenneth A; Naulleau, Patrick; Bokor, Jeffrey
2002-08-01
A rapid and convenient method has been developed to facilitate the alignment of the image-plane components of point-diffraction interferometers, including the phase-shifting point-diffraction interferometer. In real time, the Fourier transform of the detected image is used to calculate a pseudoimage of the electric field in the image plane of the test optic where thecritical alignment o f variousoptical components is performed. Reconstruction of the pseudoimage is similar to off-axis, Fourier transform holography. Intermediate steps in the alignment procedure are described. Fine alignment is aided by the introduction and optimization of a global-contrast parameter that is easily calculated from the Fourier transform. Additional applications include the alignment of image-plane apertures in general optical systems, the rapid identification of patterned image-plane alignment marks, and the probing of important image-plane field properties. PMID:12153074
An Operator Method for Evaluating Laplace Transforms
ERIC Educational Resources Information Center
Lanoue, B. G.; Yurekli, O.
2005-01-01
This note discusses a simple operator technique based on the differentiation and shifting properties of the Laplace transform to find Laplace transforms for various elementary functions. The method is simpler than known integration techniques to evaluate Laplace transforms.
Development of an Agrobacterium-based transformation system for Rhizoctonia solani
Technology Transfer Automated Retrieval System (TEKTRAN)
A 8.7 kb binary vector containing the 1.9 kb hygromycin B phosphortransferase (hyg) gene was constructed with promoter and terminator regions from the glyceraldehyde-3-phosphate- dehydrogenase (gpd) gene of Rhizoctonia solani anastomosis group 3 (AG-3) at the 5'- and 3'- gene termini of hyg. Promot...
Two Alternative Methods for Height Transformation
NASA Astrophysics Data System (ADS)
Kollo, Karin
2008-03-01
Geodesists have always been dealing with coordinate transformations. There exist various kinds of transformations, like three-dimensional (spatial datum) transformations, two-dimensional (horizontal datum) transformations and one-dimensional (eg, height) transformations. In this article we discuss height transformations. Height data is usually obtained by levelling. The problematic side of levelling is that this technique is very labour intensive and costly. Nowadays as well GPS measurements can be used, which are much faster and cheaper, but in order to use GPS measurements for height determination, we need a precise geoid model to transform GPS heights to heights above sea level. In this article two different approaches to this transformation are presented. At first, the affine transformation is discussed. The method is by nature linear, and employs the barycentric coordinates of the point, the height of which is going to be computed. Secondly, the method of fuzzy modelling is used. By these methods, the transformation surface is determined and the heights of desired points can be determined. As the input data, height information from the precise levelling campaign in Estonia is used. The computed values are tested against height information, gathered from the reference geoid model. The objectives of this research are acquiring insight into using alternative methods for height transformation as well as to statistically characterise the suitability of the proposed methods.
[Hadamard transform spectrometer mixed pixels' unmixing method].
Yan, Peng; Hu, Bing-Liang; Liu, Xue-Bin; Sun, Wei; Li, Li-Bo; Feng, Yu-Tao; Liu, Yong-Zheng
2011-10-01
Hadamard transform imaging spectrometer is a multi-channel digital transform spectrometer detection technology, this paper based on digital micromirror array device (DMD) of the Hadamard transform spectrometer working principle and instrument structure, obtained by the imaging sensor mixed pixel were analyzed, theory derived the solution of pixel aliasing hybrid method, simulation results show that the method is simple and effective to improve the accuracy of mixed pixel spectrum more than 10% recovery. PMID:22250574
A dynamic transformation method for modal synthesis.
NASA Technical Reports Server (NTRS)
Kuhar, E. J.; Stahle, C. V.
1973-01-01
This paper presents a condensation method for large discrete parameter vibration analysis of complex structures that greatly reduces truncation errors and provides accurate definition of modes in a selected frequency range. A dynamic transformation is obtained from the partitioned equations of motion that relates modes not explicity in the condensed solution to the retained modes at a selected system frequency. The generalized mass and stiffness matrices, obtained with existing modal synthesis methods, are reduced using this transformation and solved. Revised solutions are then obtained using new transformations at the calculated eigenvalues and are also used to assess the accuracy of the results. If all the modes of interest have not been obtained, the results are used to select a new set of retained coordinates and a new transformation frequency, and the procedure is repeated for another group of modes.
Physical methods for genetic plant transformation
NASA Astrophysics Data System (ADS)
Rivera, Ana Leonor; Gómez-Lim, Miguel; Fernández, Francisco; Loske, Achim M.
2012-09-01
Production of transgenic plants is a routine process for many crop species. Transgenes are introduced into plants to confer novel traits such as improved nutritional qualities, tolerance to pollutants, resistance to pathogens and for studies of plant metabolism. Nowadays, it is possible to insert genes from plants evolutionary distant from the host plant, as well as from fungi, viruses, bacteria and even animals. Genetic transformation requires penetration of the transgene through the plant cell wall, facilitated by biological or physical methods. The objective of this article is to review the state of the art of the physical methods used for genetic plant transformation and to describe the basic physics behind them.
Transformative Paradigm: Mixed Methods and Social Justice
ERIC Educational Resources Information Center
Mertens, Donna M.
2007-01-01
The intersection of mixed methods and social justice has implications for the role of the researcher and choices of specific paradigmatic perspectives. The transformative paradigm with its associated philosophical assumptions provides a framework for addressing inequality and injustice in society using culturally competent, mixed methods…
Discrete fourier transform (DFT) analysis for applications using iterative transform methods
NASA Technical Reports Server (NTRS)
Dean, Bruce H. (Inventor)
2012-01-01
According to various embodiments, a method is provided for determining aberration data for an optical system. The method comprises collecting a data signal, and generating a pre-transformation algorithm. The data is pre-transformed by multiplying the data with the pre-transformation algorithm. A discrete Fourier transform of the pre-transformed data is performed in an iterative loop. The method further comprises back-transforming the data to generate aberration data.
Parallel algorithms for the spectral transform method
Foster, I.T.; Worley, P.H.
1994-04-01
The spectral transform method is a standard numerical technique for solving partial differential equations on a sphere and is widely used in atmospheric circulation models. Recent research has identified several promising algorithms for implementing this method on massively parallel computers; however, no detailed comparison of the different algorithms has previously been attempted. In this paper, we describe these different parallel algorithms and report on computational experiments that we have conducted to evaluate their efficiency on parallel computers. The experiments used a testbed code that solves the nonlinear shallow water equations or a sphere; considerable care was taken to ensure that the experiments provide a fair comparison of the different algorithms and that the results are relevant to global models. We focus on hypercube- and mesh-connected multicomputers with cut-through routing, such as the Intel iPSC/860, DELTA, and Paragon, and the nCUBE/2, but also indicate how the results extend to other parallel computer architectures. The results of this study are relevant not only to the spectral transform method but also to multidimensional FFTs and other parallel transforms.
Ensemble transform sensitivity method for adaptive observations
NASA Astrophysics Data System (ADS)
Zhang, Yu; Xie, Yuanfu; Wang, Hongli; Chen, Dehui; Toth, Zoltan
2016-01-01
The Ensemble Transform (ET) method has been shown to be useful in providing guidance for adaptive observation deployment. It predicts forecast error variance reduction for each possible deployment using its corresponding transformation matrix in an ensemble subspace. In this paper, a new ET-based sensitivity (ETS) method, which calculates the gradient of forecast error variance reduction in terms of analysis error variance reduction, is proposed to specify regions for possible adaptive observations. ETS is a first order approximation of the ET; it requires just one calculation of a transformation matrix, increasing computational efficiency (60%-80% reduction in computational cost). An explicit mathematical formulation of the ETS gradient is derived and described. Both the ET and ETS methods are applied to the Hurricane Irene (2011) case and a heavy rainfall case for comparison. The numerical results imply that the sensitive areas estimated by the ETS and ET are similar. However, ETS is much more efficient, particularly when the resolution is higher and the number of ensemble members is larger.
Comparison of different transformation methods for Aspergillus giganteus.
Meyer, Vera; Mueller, Dirk; Strowig, Till; Stahl, Ulf
2003-08-01
Four different transformation methods were tested and compared in an attempt to facilitate the genetic transformation of Aspergillus giganteus, the producer of an antifungal protein (AFP). The fungus was transformed to hygromycin B resistance, using the hph gene of Escherichia coli by protoplast transformation, electroporation, biolistic transformation, and Agrobacterium tumefaciens-mediated transformation. Electroporation and biolistic transformation were found to be inappropriate for transforming A. giganteus, due to a low transformation yield. The conventional transformation technique based on protoplasts yielded up to 55 transformants in 10(8) protoplasts/microg DNA and was enhanced to 140-fold by A. tumefaciens-mediated transfer of its T-DNA. Here, the germination time prior to cocultivation and the fungus:bacterium ratio were found to alter the transformation efficiency. Southern blot analysis revealed that the A. giganteus transformants contained a randomly integrated single T-DNA copy, whereas multiple integration events were frequent in transformants obtained by the protoplast method. PMID:12756496
Linear Transformation Method for Multinuclide Decay Calculation
Ding Yuan
2010-12-29
A linear transformation method for generic multinuclide decay calculations is presented together with its properties and implications. The method takes advantage of the linear form of the decay solution N(t) = F(t)N{sub 0}, where N(t) is a column vector that represents the numbers of atoms of the radioactive nuclides in the decay chain, N{sub 0} is the initial value vector of N(t), and F(t) is a lower triangular matrix whose time-dependent elements are independent of the initial values of the system.
Apparatus and method for transforming living cells
Okandan, Murat; Galambos, Paul C.
2003-11-11
An apparatus and method are disclosed for in vitro transformation of living cells. The apparatus, which is formed as a microelectromechanical device by surface micromachining, can be used to temporarily disrupt the cell walls or membrane of host cells one at a time so that a particular substance (e.g. a molecular tag, nucleic acid, bacteria, virus etc.) can be introduced into the cell. Disruption of the integrity of the host cells (i.e. poration) can be performed mechanically or electrically, or by both while the host cells are contained within a flow channel. Mechanical poration is possible using a moveable member which has a pointed or serrated edge and which is driven by an electrostatic actuator to abrade, impact or penetrate the host cell. Electroporation is produced by generating a relatively high electric field across the host cell when the host cell is located in the flow channel between a pair of electrodes having a voltage applied therebetween.
A Transfer Voltage Simulation Method for Generator Step Up Transformers
NASA Astrophysics Data System (ADS)
Funabashi, Toshihisa; Sugimoto, Toshirou; Ueda, Toshiaki; Ametani, Akihiro
It has been found from measurements for 13 sets of GSU transformers that a transfer voltage of a generator step-up (GSU) transformer involves one dominant oscillation frequency. The frequency can be estimated from the inductance and capacitance values of the GSU transformer low-voltage-side. This observation has led to a new method for simulating a GSU transformer transfer voltage. The method is based on the EMTP TRANSFORMER model, but stray capacitances are added. The leakage inductance and the magnetizing resistance are modified using approximate curves for their frequency characteristics determined from the measured results. The new method is validated in comparison with the measured results.
Transformative, Mixed Methods Checklist for Psychological Research with Mexican Americans
ERIC Educational Resources Information Center
Canales, Genevieve
2013-01-01
This is a description of the creation of a research methods tool, the "Transformative, Mixed Methods Checklist for Psychological Research With Mexican Americans." For conducting literature reviews of and planning mixed methods studies with Mexican Americans, it contains evaluative criteria calling for transformative mixed methods, perspectives…
Soft computing methods for geoidal height transformation
NASA Astrophysics Data System (ADS)
Akyilmaz, O.; Özlüdemir, M. T.; Ayan, T.; Çelik, R. N.
2009-07-01
Soft computing techniques, such as fuzzy logic and artificial neural network (ANN) approaches, have enabled researchers to create precise models for use in many scientific and engineering applications. Applications that can be employed in geodetic studies include the estimation of earth rotation parameters and the determination of mean sea level changes. Another important field of geodesy in which these computing techniques can be applied is geoidal height transformation. We report here our use of a conventional polynomial model, the Adaptive Network-based Fuzzy (or in some publications, Adaptive Neuro-Fuzzy) Inference System (ANFIS), an ANN and a modified ANN approach to approximate geoid heights. These approximation models have been tested on a number of test points. The results obtained through the transformation processes from ellipsoidal heights into local levelling heights have also been compared.
Performance analysis of image fusion methods in transform domain
NASA Astrophysics Data System (ADS)
Choi, Yoonsuk; Sharifahmadian, Ershad; Latifi, Shahram
2013-05-01
Image fusion involves merging two or more images in such a way as to retain the most desirable characteristics of each. There are various image fusion methods and they can be classified into three main categories: i) Spatial domain, ii) Transform domain, and iii) Statistical domain. We focus on the transform domain in this paper as spatial domain methods are primitive and statistical domain methods suffer from a significant increase of computational complexity. In the field of image fusion, performance analysis is important since the evaluation result gives valuable information which can be utilized in various applications, such as military, medical imaging, remote sensing, and so on. In this paper, we analyze and compare the performance of fusion methods based on four different transforms: i) wavelet transform, ii) curvelet transform, iii) contourlet transform and iv) nonsubsampled contourlet transform. Fusion framework and scheme are explained in detail, and two different sets of images are used in our experiments. Furthermore, various performance evaluation metrics are adopted to quantitatively analyze the fusion results. The comparison results show that the nonsubsampled contourlet transform method performs better than the other three methods. During the experiments, we also found out that the decomposition level of 3 showed the best fusion performance, and decomposition levels beyond level-3 did not significantly affect the fusion results.
Transformer winding defects identification based on a high frequency method
NASA Astrophysics Data System (ADS)
Florkowski, Marek; Furgał, Jakub
2007-09-01
The transformer diagnostic methods are systematically being improved and extended due to growing requirements for reliability of power systems in terms of uninterrupted power supply and avoidance of blackouts. Those methods are also driven by longer lifetime of transformers and demand for reduction of transmission and distribution costs. Hence, the detection of winding faults in transformers, both in exploitation or during transportation is an important aspect of power transformer failure prevention. The frequency response analysis method (FRA), more and more frequently used in electric power engineering, has been applied for investigations and signature analysis based on the admittance and transfer function. The paper presents a novel approach to the identification of typical transformer winding problems such as axial or radial movements or turn-to-turn faults. The proposed transfer function discrimination (TFD) criteria are based on the derived transfer function ratios, manifesting higher sensitivity.
Hough transform method for track finding in center drift chamber
NASA Astrophysics Data System (ADS)
Azmi, K. A. Mohammad Kamal; Wan Abdullah, W. A. T.; Ibrahim, Zainol Abidin
2016-01-01
Hough transform is a global tracking method used which had been expected to be faster approach for tracking the circular pattern of electron moving in Center Drift Chamber (CDC), by transforming the point of hit into a circular curve. This paper present the implementation of hough transform method for the reconstruction of tracks in Center Drift Chamber (CDC) which have been generated by random number in C language programming. Result from implementation of this method shows higher peak of circle parameter value (xc,yc,rc) that indicate the similarity value of the parameter needed for circular track in CDC for charged particles in the region of CDC.
Method and Application of Hadamard Transform Spectrometry
NASA Astrophysics Data System (ADS)
Jarvis, John Michael
A new electrooptic shutter based mask had been developed and characterized for Hadamard encoding spectrometric applications. The mask is based upon a radically new implementation of liquid crystal technology using liquid crystal materials dispersed in a polymer matrix. The mask has several advantages compared to the previous state of the art. The mask contains 255 electrically switchable encoding elements to roughly double the spatial resolution. It exhibits improved On -Off contrast and has increased optical throughput when compared to prior art. A simple and inexpensive spectrometer that used the mask was designed, constructed, and characterized. The spectrometer uses a linear variable spectral filter to form the spectrum. This innovation results in an extremely simple optical design that is suitable for high light level experiments such as absorption. Light leakage limits the design to absorption determinations on samples of optical density of one or less. A special nature of the Hadamard encoded spectrum was discovered. Quantitative spectral information can be extracted from the encoded spectrum directly. The necessity to use the Hadamard transform can be circumvented. Instead, factor based regression techniques are used to form calibrations using the encodement data directly. Examples are given for quantitation of a single component in a mixture by Raman spectrometry and for two components in a mixture by absorption spectrometry. This technique promises to provide a powerful tool for using Hadamard encoded spectrometers for quantitative analysis.
A method for genetic transformation of nonprotoplasted Streptococcus lactis.
Sanders, M E; Nicholson, M A
1987-01-01
Plasmid transformation of whole cells of Streptococcus lactis LM0230 was demonstrated. The procedure required polyethylene glycol and incubation in hypertonic media, but did not require enzymatic cell wall digestion. Conditions were optimized, yielding 5 X 10(5) transformants per micrograms of pSA3 DNA. Variables tested for effect on transformation efficiency included molecular weight, concentration, and pH of polyethylene glycol; cell density; plating media; DNA concentration; heat shock; and incubation of cells in hypertonic buffer. DNAs transformed included pSA3, pVA856, pTV1, and c2 phi. Transformation from DNA-DNA ligation mixes, with DNA not purified through density gradients, and with previously frozen cells was also achieved. The method described here for transformation of nonprotoplasted cells of LM0230 is unique, and to date has not been applied successfully to other lactic acid bacteria. Images PMID:3116931
Anisotropy minimization via least squares method for transformation optics.
Junqueira, Mateus A F C; Gabrielli, Lucas H; Spadoti, Danilo H
2014-07-28
In this work the least squares method is used to reduce anisotropy in transformation optics technique. To apply the least squares method a power series is added on the coordinate transformation functions. The series coefficients were calculated to reduce the deviations in Cauchy-Riemann equations, which, when satisfied, result in both conformal transformations and isotropic media. We also present a mathematical treatment for the special case of transformation optics to design waveguides. To demonstrate the proposed technique a waveguide with a 30° of bend and with a 50% of increase in its output width was designed. The results show that our technique is simultaneously straightforward to be implement and effective in reducing the anisotropy of the transformation for an extremely low value close to zero. PMID:25089468
Direct Linear Transformation Method for Three-Dimensional Cinematography
ERIC Educational Resources Information Center
Shapiro, Robert
1978-01-01
The ability of Direct Linear Transformation Method for three-dimensional cinematography to locate points in space was shown to meet the accuracy requirements associated with research on human movement. (JD)
Data transformation methods for multiplexed assays
Tammero, Lance F. Bentley; Dzenitis, John M; Hindson, Benjamin J
2013-07-23
Methods to improve the performance of an array assay are described. A correlation between fluorescence intensity-related parameters and negative control values of the assay is determined. The parameters are then adjusted as a function of the correlation. As a result, sensitivity of the assay is improved without changes in its specificity.
Cell Phones Transform a Science Methods Course
ERIC Educational Resources Information Center
Madden, Lauren
2012-01-01
A science methods instructor intentionally encouraged cell phone use for class work to discover how cell phones can be used as research tools to enhance the content and engage the students. The anecdotal evidence suggested that students who used their smartphones as research tools experienced the science content and pedagogical information…
A method for encapsulating high voltage power transformers
NASA Astrophysics Data System (ADS)
Sanchez, Robert O.
Voltage breakdowns become a major concern in reducing the size of high-voltage power converter transformers. Even the smallest of voids can provide a path for corona discharge which can cause a dielectric breakdown leading to a transformer failure. A method of encapsulating small high voltage transformers has been developed. The method virtually eliminates voids in the impregnation material, provides an exceptional dielectric between windings and provides a mechanically rugged package. The encapsulation material is a carboxyl terminated butadiene nitril (CTBN) modified mica filled epoxy. The method requires heat/vacuum to impregnate the coil and heat/pressure to cure the encapsulant. The transformer package utilizes a diallyl phthalate (DAP) contact assembly in which a coated core/coil assembly is mounted and soldered. This assembly is then loaded into an RTV mold and the encapsulation process begins.
A method for encapsulating high voltage power transformers
Sanchez, R.O.
1990-01-01
Voltage breakdowns become a major concern in reducing the size of high-voltage power converter transformers. Even the smallest of voids can provide a path for corona discharge which can cause a dielectric breakdown leading to a transformer failure. A method of encapsulating small high voltage transformers has been developed. The method virtually eliminates voids in the impregnation material, provides an exceptional dielectric between windings and provides a mechanically rugged package. The encapsulation material is a CTBN modified mica filled epoxy. The method requires heat/vacuum to impregnate the coil and heat/pressure to cure the encapsulant. The transformer package utilizes a Diallyl Phthalate (DAP) contact assembly in which a coated core/coil assembly is mounted and soldered. This assembly is then loaded into an RTV mold and the encapsulation process begins.
Analytical method for space-fractional telegraph equation by homotopy perturbation transform method
NASA Astrophysics Data System (ADS)
Prakash, Amit
2016-06-01
The object of the present article is to study spacefractional telegraph equation by fractional Homotopy perturbation transform method (FHPTM). The homotopy perturbation transform method is an innovative adjustment in Laplace transform algorithm. Three test examples are presented to show the efficiency of the proposed technique.
Transforming han: a correlational method for psychology and religion.
Oh, Whachul
2015-06-01
Han is a destructive feeling in Korea. Although Korea accomplished significant exterior growth, Korean society is still experiencing the dark aspects of transforming han as evidenced by having the highest suicide rate in Asia. Some reasons for this may be the fragmentation between North and South Korea. If we can transform han then it can become constructive. I was challenged to think of possibilities for transforming han internally; this brings me to the correlational method through psychological and religious interpretation. This study is to challenge and encourage many han-ridden people in Korean society. Through the psychological and religious understanding of han, people suffering can positively transform their han. They can relate to han more subjectively, and this means the han-ridden psyche has an innate sacredness of potential to transform. PMID:25252804
Transformation of Morinda citrifolia via simple mature seed imbibition method.
Lee, J J; Ahmad, S; Roslan, H A
2013-12-15
Morinda citrifolia, is a valuable medicinal plant with a wide range of therapeutic properties and extensive transformation study on this plant has yet been known. Present study was conducted to establish a simple and reliable transformation protocol for M. citrifolia utilising Agrobacterium tumefaciens via direct seed exposure. In this study, the seeds were processed by tips clipping and dried and subsequently incubated in inoculation medium. Four different parameters during the incubation such as incubation period, bacterial density, temperature and binary vectors harbouring beta-glucuronidase (GUS) gene (pBI121 and pGSA1131), were tested to examine its effect on transformation efficiency. The leaves from the treated and germinated seedlings were analysed via Polymerase Chain Reaction (PCR), histochemical assay of the GUS gene and reverse transcription-PCR (RT-PCR). Results of the study showed that Agrobacterium strain LBA4404 with optical density of 1.0 and 2 h incubation period were optimum for M. citrifolia transformation. It was found that various co-cultivation temperatures tested and type of vector used did not affect the transformation efficiency. The highest transformation efficiency for M. citrifolia direct seed transformation harbouring pBI121 and pGSA1131 was determined to be 96.8% with 2 h co-cultivation treatment and 80.4% when using bacterial density of 1.0, respectively. The transformation method can be applied for future characterization study of M. citrifolia. PMID:24517006
Spindle extraction method for ISAR image based on Radon transform
NASA Astrophysics Data System (ADS)
Wei, Xia; Zheng, Sheng; Zeng, Xiangyun; Zhu, Daoyuan; Xu, Gaogui
2015-12-01
In this paper, a method of spindle extraction of target in inverse synthetic aperture radar (ISAR) image is proposed which depends on Radon Transform. Firstly, utilizing Radon Transform to detect all straight lines which are collinear with these line segments in image. Then, using Sobel operator to detect image contour. Finally, finding all intersections of each straight line and image contour, the two intersections which have maximum distance between them is the two ends of this line segment and the longest line segment of all line segments is spindle of target. According to the proposed spindle extraction method, one hundred simulated ISAR images which are respectively rotated 0 degrees, 10 degrees, 20 degrees, 30 degrees and 40 degrees in counterclockwise are used to do experiment and the proposed method and the detection results are more close to the real spindle of target than the method based on Hough Transform .
Transformation ray method: controlling high frequency elastic waves (L).
Chang, Zheng; Liu, Xiaoning; Hu, Gengkai; Hu, Jin
2012-10-01
Elastic ray theory is a high frequency asymptotic approximation of solution of elastodynamic equation, and is widely used in seismology. In this paper, the form invariance under a general spatial mapping and high frequency wave control have been examined by transformation method. It is showed that with the constraint of major and minor symmetry of the transformed elastic tensor, the eikonal equation keeps its form under a general mapping, however, the transport equation loses its form except for conformal mapping. Therefore, the elastic ray path can be controlled in an exact manner by a transformation method, whereas energy distribution along the ray is only approximately controlled. An elastic rotator based on ray tracing method is also provided to illustrate the method and to access the approximation. PMID:23039561
A new image fusion method based on curvelet transform
NASA Astrophysics Data System (ADS)
Chu, Binbin; Yang, Xiushun; Qi, Dening; Li, Congli; Lu, Wei
2010-02-01
A new image fusion method based on Multiscale Geometric Analysis (MGA), which uses the improved fusion rules, is put forward in this paper. Firstly, the input low-level-light image and infrared image are decomposed by Curvelet transform, which is realized by Unequally-Spaced Fast Fourier Transforms. Secondly, the decomposed coefficients in different scales and directions are fused by corresponding fusion rules. At last, the fusion image is acquired by recomposing the fused coefficients. The simulation results show that this method performs better than the conventional wavelet method both in the subjective vision aspect and the objective estimation indices.
Use of the Transformative Framework in Mixed Methods Studies
ERIC Educational Resources Information Center
Sweetman, David; Badiee, Manijeh; Creswell, John W.
2010-01-01
A concern exists that mixed methods studies do not contain advocacy stances. Preliminary evidence suggests that this is not the case, but to address this issue in more depth the authors examined 13 mixed methods studies that contained an advocacy, transformative lens. Such a lens consisted of incorporating intent to advocate for an improvement in…
Glass bead transformation method for gram-positive bacteria
Rattanachaikunsopon, Pongsak; Phumkhachorn, Parichat
2009-01-01
A simple, inexpensive and reproducible transformation method was developed for Gram-positive bacteria. It was based on agitation of bacterial protoplasts with glass beads in the presence of DNA and polyethylene glycol. By using this method, introduction of pGK12 into protoplasts of several strains of Gram-positive bacteria was achieved. PMID:24031442
Transforming Mean and Osculating Elements Using Numerical Methods
NASA Technical Reports Server (NTRS)
Ely, Todd A.
2010-01-01
Mean element propagation of perturbed two body orbits has as its mathematical basis averaging theory of nonlinear dynamical systems. Averaged mean elements define the long-term evolution characteristics of an orbit. Using averaging theory, a near identity transformation can be found that transforms the mean elements back to the osculating elements that contain short period terms in addition to the secular and long period mean elements. The ability to perform the conversion is necessary so that orbit design conducted in mean elements can be converted back into osculating results. In the present work, this near identity transformation is found using the Fast Fourier Transform. An efficient method is found that is capable of recovering the osculating elements to first order
Transforming Mean and Osculating Elements Using Numerical Methods
NASA Astrophysics Data System (ADS)
Ely, Todd A.
2015-03-01
Mean element propagation of perturbed two body orbits has as its mathematical basis the averaging theory of nonlinear dynamical systems. Mean elements define an orbit's long-term evolution characteristics consisting of both secular and long-period effects. Using averaging theory, a near-identity transformation can be found that transforms between the mean elements and their osculating counterparts that augment the mean elements with short period effects. The ability to perform the conversion is necessary so that orbit design conducted in either mean elements or osculating can be effectively converted between each element type. In the present work, the near-identity transformation is found using the Fast Fourier Transform. An efficient method is found that is capable of recovering the mean or osculating elements to first-order.
Analysis of Tibet NM Data with Wavelet Transform Method
NASA Astrophysics Data System (ADS)
Tang, Y. Q.; Lu, H.; Hu H. B.; Tan, Y. H.; Zhang, J. L.; Le, G. M.; Labaciren; Meng, X. R.; Yuan, A. F.; Miyasaka, H.; Shimoda, S.; Yamada, Sakamoto, E.; Munakata, K.; Yuda, T.; Tibet NM Collaboration
2003-07-01
The China-Japan coop erative Tibet neutron monitor(90.53°E,30.11° N,4300 m a.s.l.)b egan to work in October 1998.Now we have about 4 years data covering the 23rd solar maximum period.This is a work on correlative study of solar activity and cosmic ray intensity(CRI) by means of wavelet transform method,which is more sensitive to detect sharp variation points of CRI than Fourier transform method,these points represent modulation to cosmic rays of solar activities,esp ecially CME, which is thought as the main source of geomagnetic storm. After analysis,we find that CRI can provide some precursory imformation of CME.So CRI data can predict geomagnetic storm by wavelet transform analysis.
Physical methods for genetic transformation of fungi and yeast
NASA Astrophysics Data System (ADS)
Rivera, Ana Leonor; Magaña-Ortíz, Denis; Gómez-Lim, Miguel; Fernández, Francisco; Loske, Achim M.
2014-06-01
The production of transgenic fungi is a routine process. Currently, it is possible to insert genes from other fungi, viruses, bacteria and even animals, albeit with low efficiency, into the genomes of a number of fungal species. Genetic transformation requires the penetration of the transgene through the fungal cell wall, a process that can be facilitated by biological or physical methods. Novel methodologies for the efficient introduction of specific genes and stronger promoters are needed to increase production levels. A possible solution to this problem is the recently discovered shock-wave-mediated transformation. The objective of this article is to review the state of the art of the physical methods used for genetic fungi transformation and to describe some of the basic physics and molecular biology behind them.
Physical methods for genetic transformation of fungi and yeast.
Rivera, Ana Leonor; Magaña-Ortíz, Denis; Gómez-Lim, Miguel; Fernández, Francisco; Loske, Achim M
2014-06-01
The production of transgenic fungi is a routine process. Currently, it is possible to insert genes from other fungi, viruses, bacteria and even animals, albeit with low efficiency, into the genomes of a number of fungal species. Genetic transformation requires the penetration of the transgene through the fungal cell wall, a process that can be facilitated by biological or physical methods. Novel methodologies for the efficient introduction of specific genes and stronger promoters are needed to increase production levels. A possible solution to this problem is the recently discovered shock-wave-mediated transformation. The objective of this article is to review the state of the art of the physical methods used for genetic fungi transformation and to describe some of the basic physics and molecular biology behind them. PMID:24507729
Approximate method for controlling solid elastic waves by transformation media
NASA Astrophysics Data System (ADS)
Hu, Jin; Chang, Zheng; Hu, Gengkai
2011-11-01
By idealizing a general mapping as a series of local affine ones, we derive approximately transformed material parameters necessary to control solid elastic waves within classical elasticity theory. The transformed elastic moduli are symmetric, and can be used with Navier's equation to manipulate elastic waves. It is shown numerically that the method can provide a powerful tool to control elastic waves in solids in case of high frequency or small material gradient. Potential applications can be anticipated in nondestructive testing, structure impact protection, petroleum exploration, and seismology.
Fourier-transform and global contrast interferometer alignment methods
Goldberg, Kenneth A.
2001-01-01
Interferometric methods are presented to facilitate alignment of image-plane components within an interferometer and for the magnified viewing of interferometer masks in situ. Fourier-transforms are performed on intensity patterns that are detected with the interferometer and are used to calculate pseudo-images of the electric field in the image plane of the test optic where the critical alignment of various components is being performed. Fine alignment is aided by the introduction and optimization of a global contrast parameter that is easily calculated from the Fourier-transform.
Frequency-dependent FDTD methods using Z transforms
NASA Technical Reports Server (NTRS)
Sullivan, Dennis M.
1992-01-01
While the frequency-dependent finite-difference time-domain, or (FD)2TD, method can correctly calculate EM propagation through media whose dielectric properties are frequency-dependent, more elaborate applications lead to greater (FD)2TD complexity. Z-transform theory is presently used to develop the mathematical bases of the (FD)2TD method, simultaneously obtaining a clearer formulation and allowing researchers to draw on the existing literature of systems analysis and signal-processing.
A Secret Image Sharing Method Using Integer Wavelet Transform
NASA Astrophysics Data System (ADS)
Huang, Chin-Pan; Li, Ching-Chung
2007-12-01
A new image sharing method, based on the reversible integer-to-integer (ITI) wavelet transform and Shamir's [InlineEquation not available: see fulltext.] threshold scheme is presented, that provides highly compact shadows for real-time progressive transmission. This method, working in the wavelet domain, processes the transform coefficients in each subband, divides each of the resulting combination coefficients into [InlineEquation not available: see fulltext.] shadows, and allows recovery of the complete secret image by using any [InlineEquation not available: see fulltext.] or more shadows [InlineEquation not available: see fulltext.]. We take advantages of properties of the wavelet transform multiresolution representation, such as coefficient magnitude decay and excellent energy compaction, to design combination procedures for the transform coefficients and processing sequences in wavelet subbands such that small shadows for real-time progressive transmission are obtained. Experimental results demonstrate that the proposed method yields small shadow images and has the capabilities of real-time progressive transmission and perfect reconstruction of secret images.
A dynamic integrated fault diagnosis method for power transformers.
Gao, Wensheng; Bai, Cuifen; Liu, Tong
2015-01-01
In order to diagnose transformer fault efficiently and accurately, a dynamic integrated fault diagnosis method based on Bayesian network is proposed in this paper. First, an integrated fault diagnosis model is established based on the causal relationship among abnormal working conditions, failure modes, and failure symptoms of transformers, aimed at obtaining the most possible failure mode. And then considering the evidence input into the diagnosis model is gradually acquired and the fault diagnosis process in reality is multistep, a dynamic fault diagnosis mechanism is proposed based on the integrated fault diagnosis model. Different from the existing one-step diagnosis mechanism, it includes a multistep evidence-selection process, which gives the most effective diagnostic test to be performed in next step. Therefore, it can reduce unnecessary diagnostic tests and improve the accuracy and efficiency of diagnosis. Finally, the dynamic integrated fault diagnosis method is applied to actual cases, and the validity of this method is verified. PMID:25685841
The gridding method for image reconstruction by Fourier transformation
Schomberg, H.; Timmer, J.
1995-09-01
This paper explores a computational method for reconstructing an n-dimensional signal f from a sampled version of its Fourier transform {cflx f}. The method involves a window function {cflx w} and proceeds in three steps. First, the convolution {cflx g} = {cflx w} * {cflx f} is computed numerically on a Cartesian grid, using the available samples of {cflx f}. Then, g = wf is computed via the inverse discrete Fourier transform, and finally f is obtained as g/w. Due to the smoothing effect of the convolution, evaluating {cflx w} * {cflx f} is much less error prone than merely interpolating {cflx f}. The method was originally devised for image reconstruction in radio astronomy, but is actually applicable to a broad range of reconstructive imaging methods, including magnetic resonance imaging and computed tomography. In particular, it provides a fast and accurate alternative to the filtered backprojection. The basic method has several variants with other applications, such as the equidistant resampling of arbitrarily sampled signals or the fast computation of the Radon (Hough) transform.
A transformation method for constrained-function minimization
NASA Technical Reports Server (NTRS)
Park, S. K.
1975-01-01
A direct method for constrained-function minimization is discussed. The method involves the construction of an appropriate function mapping all of one finite dimensional space onto the region defined by the constraints. Functions which produce such a transformation are constructed for a variety of constraint regions including, for example, those arising from linear and quadratic inequalities and equalities. In addition, the computational performance of this method is studied in the situation where the Davidon-Fletcher-Powell algorithm is used to solve the resulting unconstrained problem. Good performance is demonstrated for 19 test problems by achieving rapid convergence to a solution from several widely separated starting points.
Comparison of Fourier transform methods for calculating MTF
NASA Astrophysics Data System (ADS)
LaVeigne, Joseph D.; Burks, Stephen D.; Nehring, Brian
2008-04-01
Fourier transform methods common in infrared spectroscopy were applied to the problem of calculating the modulation transfer function (MTF) from a system's measured line spread function (LSF). Algorithms, including apodization and phase correction, are discussed in their application to remove unwanted noise from the higher frequency portion of the MTF curve. In general, these methods were found to significantly improve the calculated MTF. Apodization reduces the proportion of noise by discarding areas of the LSF where there is no appreciable signal. Phase correction significantly reduces the rectification of noise that occurs when the MTF is calculated by taking the power spectrum of the complex optical transfer function (OTF).
Measurement matrix optimization method based on matrix orthogonal similarity transformation
NASA Astrophysics Data System (ADS)
Pan, Jinfeng
2016-05-01
Optimization of the measurement matrix is one of the important research aspects of compressive sensing theory. A measurement matrix optimization method is presented based on the orthogonal similarity transformation of the information operator's Gram matrix. In terms of the fact that the information operator's Gram matrix is a singular symmetric matrix, a simplified orthogonal similarity transformation is deduced, and thus the simplified diagonal matrix that is orthogonally similar to it is obtained. Then an approximation of the Gram matrix is obtained by letting all the nonzero diagonal entries of the simplified diagonal matrix equal their average value. Thus an optimized measurement matrix can be acquired according to its relationship with the information operator. Results of experiments show that the optimized measurement matrix compared to the random measurement matrix is less coherent with dictionaries. The relative signal recovery error also declines when the proposed measurement matrix is utilized.
Electrocardiogram ST-Segment Morphology Delineation Method Using Orthogonal Transformations
2016-01-01
Differentiation between ischaemic and non-ischaemic transient ST segment events of long term ambulatory electrocardiograms is a persisting weakness in present ischaemia detection systems. Traditional ST segment level measuring is not a sufficiently precise technique due to the single point of measurement and severe noise which is often present. We developed a robust noise resistant orthogonal-transformation based delineation method, which allows tracing the shape of transient ST segment morphology changes from the entire ST segment in terms of diagnostic and morphologic feature-vector time series, and also allows further analysis. For these purposes, we developed a new Legendre Polynomials based Transformation (LPT) of ST segment. Its basis functions have similar shapes to typical transient changes of ST segment morphology categories during myocardial ischaemia (level, slope and scooping), thus providing direct insight into the types of time domain morphology changes through the LPT feature-vector space. We also generated new Karhunen and Lo ève Transformation (KLT) ST segment basis functions using a robust covariance matrix constructed from the ST segment pattern vectors derived from the Long Term ST Database (LTST DB). As for the delineation of significant transient ischaemic and non-ischaemic ST segment episodes, we present a study on the representation of transient ST segment morphology categories, and an evaluation study on the classification power of the KLT- and LPT-based feature vectors to classify between ischaemic and non-ischaemic ST segment episodes of the LTST DB. Classification accuracy using the KLT and LPT feature vectors was 90% and 82%, respectively, when using the k-Nearest Neighbors (k = 3) classifier and 10-fold cross-validation. New sets of feature-vector time series for both transformations were derived for the records of the LTST DB which is freely available on the PhysioNet website and were contributed to the LTST DB. The KLT and LPT
Electrocardiogram ST-Segment Morphology Delineation Method Using Orthogonal Transformations.
Amon, Miha; Jager, Franc
2016-01-01
Differentiation between ischaemic and non-ischaemic transient ST segment events of long term ambulatory electrocardiograms is a persisting weakness in present ischaemia detection systems. Traditional ST segment level measuring is not a sufficiently precise technique due to the single point of measurement and severe noise which is often present. We developed a robust noise resistant orthogonal-transformation based delineation method, which allows tracing the shape of transient ST segment morphology changes from the entire ST segment in terms of diagnostic and morphologic feature-vector time series, and also allows further analysis. For these purposes, we developed a new Legendre Polynomials based Transformation (LPT) of ST segment. Its basis functions have similar shapes to typical transient changes of ST segment morphology categories during myocardial ischaemia (level, slope and scooping), thus providing direct insight into the types of time domain morphology changes through the LPT feature-vector space. We also generated new Karhunen and Lo ève Transformation (KLT) ST segment basis functions using a robust covariance matrix constructed from the ST segment pattern vectors derived from the Long Term ST Database (LTST DB). As for the delineation of significant transient ischaemic and non-ischaemic ST segment episodes, we present a study on the representation of transient ST segment morphology categories, and an evaluation study on the classification power of the KLT- and LPT-based feature vectors to classify between ischaemic and non-ischaemic ST segment episodes of the LTST DB. Classification accuracy using the KLT and LPT feature vectors was 90% and 82%, respectively, when using the k-Nearest Neighbors (k = 3) classifier and 10-fold cross-validation. New sets of feature-vector time series for both transformations were derived for the records of the LTST DB which is freely available on the PhysioNet website and were contributed to the LTST DB. The KLT and LPT
Method to transform algae, materials therefor, and products produced thereby
Dunahay, T.G.; Roessler, P.G.; Jarvis, E.E.
1997-08-26
Disclosed is a method to transform chlorophyll C-containing algae. The method includes introducing a recombinant molecule comprising a nucleic acid molecule encoding a dominant selectable marker operatively linked to an algal regulatory control sequence into a chlorophyll C-containing alga in such a manner that the marker is produced by the alga. In a preferred embodiment the algal regulatory control sequence is derived from a diatom and preferably Cyclotella cryptica. Also disclosed is a chimeric molecule having one or more regulatory control sequences derived from one or more chlorophyll C-containing algae operatively linked to a nucleic acid molecule encoding a selectable marker, an RNA molecule and/or a protein, wherein the nucleic acid molecule does not normally occur with one or more of the regulatory control sequences. Further, specifically disclosed are molecules pACCNPT10, pACCNPT4.8 and pACCNPT5.1. The methods and materials of the present invention provide the ability to accomplish stable genetic transformation of chlorophyll C-containing algae. 2 figs.
Universal calculation formula and calibration method in Fourier transform profilometry
Wen Yongfu; Li Sikun; Cheng Haobo; Su Xianyu; Zhang Qican
2010-12-01
We propose a universal calculation formula of Fourier transform profilometry and give a strict theoretical analysis about the phase-height mapping relation. As the request on the experimental setup of the universal calculation formula is unconfined, the projector and the camera can be located arbitrarily to get better fringe information, which makes the operation flexible. The phase-height calibration method under the universal condition is proposed, which can avoid measuring the system parameters directly. It makes the system easy to manipulate and improves the measurement velocity. A computer simulation and experiment are conducted to verify its validity. The calculation formula and calibration method have been applied to measure an object of 22.00 mm maximal height. The relative error of the measurement result is only 0.59%. The experimental results prove that the three-dimensional shape of tested objects can be reconstructed exactly by using the calculation formula and calibration method, and the system has better universality.
Method to transform algae, materials therefor, and products produced thereby
Dunahay, Terri Goodman; Roessler, Paul G.; Jarvis, Eric E.
1997-01-01
Disclosed is a method to transform chlorophyll C-containing algae which includes introducing a recombinant molecule comprising a nucleic acid molecule encoding a dominant selectable marker operatively linked to an algal regulatory control sequence into a chlorophyll C-containing alga in such a manner that the marker is produced by the alga. In a preferred embodiment the algal regulatory control sequence is derived from a diatom and preferably Cyclotella cryptica. Also disclosed is a chimeric molecule having one or more regulatory control sequences derived from one or more chlorophyll C-containing algae operatively linked to a nucleic acid molecule encoding a selectable marker, an RNA molecule and/or a protein, wherein the nucleic acid molecule does not normally occur with one or more of the regulatory control sequences. Further specifically disclosed are molecules pACCNPT10, pACCNPT4.8 and pACCNPT5.1. The methods and materials of the present invention provide the ability to accomplish stable genetic transformation of chlorophyll C-containing algae.
Zoom synchrosqueezing transform and iterative demodulation: Methods with application
NASA Astrophysics Data System (ADS)
Cao, Hongrui; Xi, Songtao; Chen, Xuefeng; Wang, Shibin
2016-05-01
Synchrosqueezing is a powerful time-frequency analysis tool for signals with time-varying frequency. However, as it is based on the continuous wavelet transform, its time-frequency representation (TFR) has better time but worse frequency resolution in higher frequency region, while worse time but better frequency resolution in lower frequency region. It makes the synchrosqueezing difficult to accurately estimate IFs with highly oscillating rate but small fluctuation amplitude. To address this issue, a zoom synchrosqueezing transform (ZST) is proposed to generate both excellent time and frequency resolution in a specific frequency region and analyze the mono-component signal in the particular frequency region to obtain accurate IF estimation results. For multi-component signals with nonlinear and close IFs, a ZST based dual iterative demodulation method is proposed, with the inner iteration to gradually refine and accurately extract a concerned mono-component, and the outer iteration to extract all mono-components gradually to alleviate the interference between individual components. Then satisfactory energy concentrated TFRs and accurate IF estimation results of mono-components can be obtained by the proposed ZST. The TFR of the multi-component signal can be gained by superposing the TFRs of all mono-components. The effectiveness of the proposed methods was validated using both simulated signals and a rub-impact signal collected from an engineering machine unit.
Transformational Teaching: Theoretical Underpinnings, Basic Principles, and Core Methods
Slavich, George M.; Zimbardo, Philip G.
2012-01-01
Approaches to classroom instruction have evolved considerably over the past 50 years. This progress has been spurred by the development of several learning principles and methods of instruction, including active learning, student-centered learning, collaborative learning, experiential learning, and problem-based learning. In the present paper, we suggest that these seemingly different strategies share important underlying characteristics and can be viewed as complimentary components of a broader approach to classroom instruction called transformational teaching. Transformational teaching involves creating dynamic relationships between teachers, students, and a shared body of knowledge to promote student learning and personal growth. From this perspective, instructors are intellectual coaches who create teams of students who collaborate with each other and with their teacher to master bodies of information. Teachers assume the traditional role of facilitating students’ acquisition of key course concepts, but do so while enhancing students’ personal development and attitudes toward learning. They accomplish these goals by establishing a shared vision for a course, providing modeling and mastery experiences, challenging and encouraging students, personalizing attention and feedback, creating experiential lessons that transcend the boundaries of the classroom, and promoting ample opportunities for preflection and reflection. We propose that these methods are synergistically related and, when used together, maximize students’ potential for intellectual and personal growth. PMID:23162369
Linear transformation method to control flexural waves in thin plates.
Liu, Yongquan; Ma, Zhaoyang; Su, Xianyue
2016-08-01
In this paper, the linear transformation method (LTM) to control flexural waves propagating in thin plates is presented. Unlike earlier studies, only a small number of homogeneous materials with no requirement of in-plane forces or pre-stress are needed, which tremendously simplifies the implementation of devices for flexural waves. An invisibility cloak with homogeneous materials is studied to confirm the validity of the present approach, and to show its imperfection due to impedance mismatch at interfaces. Required materials can be further simplified as layered isotropic materials using the effective medium theory. Finally, the LTM can be extended to the case of flexural waves propagating in anisotropic thin plates. The present method opens a promising avenue toward the realization of advanced structured shields and other devices. PMID:27586744
Optimal PMU placement using topology transformation method in power systems.
Rahman, Nadia H A; Zobaa, Ahmed F
2016-09-01
Optimal phasor measurement units (PMUs) placement involves the process of minimizing the number of PMUs needed while ensuring the entire power system completely observable. A power system is identified observable when the voltages of all buses in the power system are known. This paper proposes selection rules for topology transformation method that involves a merging process of zero-injection bus with one of its neighbors. The result from the merging process is influenced by the selection of bus selected to merge with the zero-injection bus. The proposed method will determine the best candidate bus to merge with zero-injection bus according to the three rules created in order to determine the minimum number of PMUs required for full observability of the power system. In addition, this paper also considered the case of power flow measurements. The problem is formulated as integer linear programming (ILP). The simulation for the proposed method is tested by using MATLAB for different IEEE bus systems. The explanation of the proposed method is demonstrated by using IEEE 14-bus system. The results obtained in this paper proved the effectiveness of the proposed method since the number of PMUs obtained is comparable with other available techniques. PMID:27489729
Novel fringe scanning/Fourier transform method of synthetic imaging
Crawford, T.M.; Albano, R.K.
1993-08-01
We have developed a one-dimensional theory and a computer model for synthetically imaging scenes using a novel fringe scanning/Fourier transform technique. Our method probes a scene using two interfering beams of slightly different frequency. These beams form a moving fringe pattern which scans the scene and resonates with any spatial frequency components having the same spatial frequency as the scanning fringe pattern. A simple, non-imaging detector above the scene observes any scattered radiation from the scene falling onto it. If a resonance occurs between the scanning fringe pattern and the scene, then the scattered radiation will be modulated at the difference frequency between the two probing beams. By changing the spatial period of the fringe pattern and then measuring the amplitude and phase of the modulated radiation that is scattered from the scene, the Fourier amplitudes and phases of the different spatial frequency components making up the scene can be measured. A synthetic image of the scene being probed can be generated from this Fourier amplitude and phase data by taking the inverse Fourier transform of this information. This technique could be used to image objects using light, ultrasonic, or other electromagnetic or acoustic waves.
LACKS,S.A.
2003-10-09
Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).
A modified Monte Carlo 'local importance function transform' method
Keady, K. P.; Larsen, E. W.
2013-07-01
The Local Importance Function Transform (LIFT) method uses an approximation of the contribution transport problem to bias a forward Monte-Carlo (MC) source-detector simulation [1-3]. Local (cell-based) biasing parameters are calculated from an inexpensive deterministic adjoint solution and used to modify the physics of the forward transport simulation. In this research, we have developed a new expression for the LIFT biasing parameter, which depends on a cell-average adjoint current to scalar flux (J{sup *}/{phi}{sup *}) ratio. This biasing parameter differs significantly from the original expression, which uses adjoint cell-edge scalar fluxes to construct a finite difference estimate of the flux derivative; the resulting biasing parameters exhibit spikes in magnitude at material discontinuities, causing the original LIFT method to lose efficiency in problems with high spatial heterogeneity. The new J{sup *}/{phi}{sup *} expression, while more expensive to obtain, generates biasing parameters that vary smoothly across the spatial domain. The result is an improvement in simulation efficiency. A representative test problem has been developed and analyzed to demonstrate the advantage of the updated biasing parameter expression with regards to solution figure of merit (FOM). For reference, the two variants of the LIFT method are compared to a similar variance reduction method developed by Depinay [4, 5], as well as MC with deterministic adjoint weight windows (WW). (authors)
Method and apparatus for calibrating a linear variable differential transformer
Pokrywka, Robert J.
2005-01-18
A calibration apparatus for calibrating a linear variable differential transformer (LVDT) having an armature positioned in au LVDT armature orifice, and the armature able to move along an axis of movement. The calibration apparatus includes a heating mechanism with an internal chamber, a temperature measuring mechanism for measuring the temperature of the LVDT, a fixture mechanism with an internal chamber for at least partially accepting the LVDT and for securing the LVDT within the heating mechanism internal chamber, a moving mechanism for moving the armature, a position measurement mechanism for measuring the position of the armature, and an output voltage measurement mechanism. A method for calibrating an LVDT, including the steps of: powering the LVDT; heating the LVDT to a desired temperature; measuring the position of the armature with respect to the armature orifice; and measuring the output voltage of the LVDT.
Method and Appartus for Calibrating a Linear Variable Differential Transformer
Pokrywka, Robert J.
2005-01-18
A calibration apparatus for calibrating a linear variable differential transformer (LVDT) having an armature positioned in au LVDT armature orifice, and the armature able to move along an axis of movement. The calibration apparatus includes a heating mechanism with an internal chamber, a temperature measuring mechanism for measuring the temperature of the LVDT, a fixture mechanism with an internal chamber for at least partially accepting the LVDT and for securing the LVDT within the heating mechanism internal chamber, a moving mechanism for moving the armature, a position measurement mechanism for measuring the position of the armature, and an output voltage measurement mechanism. A method for calibrating an LVDT, including the steps of powering the LVDT; heating the LVDT to a desired temperature; measuring the position of the armature with respect to the armature orifice; and measuring the output voltage of the LVDT.
A study of geometric phase topology using Fourier transform method
NASA Astrophysics Data System (ADS)
Samlan, C. T.; Naik, Dinesh N.; Viswanathan, Nirmal K.
2016-07-01
Topological aspect of the geometric phase (GP) due to pure polarization projection is studied using the 2D Fourier transform (2D-FT) method. Projection of orthogonal polarization state results in a phase singularity in the 2D parameter space of ellipticity and orientation of polarization ellipse. Projection of its surrounding states results in an accumulation of GP in different amount that form a spiral structure. A half wave plate–quarter wave plate combination is used to generate different polarization states which are projected using a polarizer. The accumulated phase for each orientation of the wave plate is extracted from 2D-FT of the interferogram, obtained by interfering it with a reference beam in a Mach–Zehnder like interferometer.
Baker, W.R.
1959-08-25
Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.
Evolute-based Hough transform method for characterization of ellipsoids.
Kaytanli, B; Valentine, M T
2013-03-01
We propose a novel and algorithmically simple Hough transform method that exploits the geometric properties of ellipses to enable the robust determination of the ellipse position and properties. We make use of the unique features of the evolute created by Hough voting along the gradient vectors of a two-dimensional image to determine the ellipse centre, orientation and aspect ratio. A second one-dimensional voting is performed on the minor axis to uniquely determine the ellipse size. This reduction of search space substantially simplifies the algorithmic complexity. To demonstrate the accuracy of our method, we present analysis of single and multiple ellipsoidal particles, including polydisperse and imperfect ellipsoids, in both simulated images and electron micrographs. Given its mathematical simplicity, ease of implementation and reasonable algorithmic completion time, we anticipate that the proposed method will be broadly useful for image processing of ellipsoidal particles, including their detection and tracking for studies of colloidal suspensions, and for applications to drug delivery and microrheology. PMID:23301634
Method of Estimating Continuous Cooling Transformation Curves of Glasses
NASA Technical Reports Server (NTRS)
Zhu, Dongmei; Zhou, Wancheng; Ray, Chandra S.; Day, Delbert E.
2006-01-01
A method is proposed for estimating the critical cooling rate and continuous cooling transformation (CCT) curve from isothermal TTT data of glasses. The critical cooling rates and CCT curves for a group of lithium disilicate glasses containing different amounts of Pt as nucleating agent estimated through this method are compared with the experimentally measured values. By analysis of the experimental and calculated data of the lithium disilicate glasses, a simple relationship between the crystallized amount in the glasses during continuous cooling, X, and the temperature of undercooling, (Delta)T, was found to be X = AR(sup-4)exp(B (Delta)T), where (Delta)T is the temperature difference between the theoretical melting point of the glass composition and the temperature in discussion, R is the cooling rate, and A and B are constants. The relation between the amount of crystallisation during continuous cooling and isothermal hold can be expressed as (X(sub cT)/X(sub iT) = (4/B)(sup 4) (Delta)T(sup -4), where X(sub cT) stands for the crystallised amount in a glass during continuous cooling for a time t when the temperature comes to T, and X(sub iT) is the crystallised amount during isothermal hold at temperature T for a time t.
Category's analysis and operational project capacity method of transformation in design
NASA Astrophysics Data System (ADS)
Obednina, S. V.; Bystrova, T. Y.
2015-10-01
The method of transformation is attracting widespread interest in fields such contemporary design. However, in theory of design little attention has been paid to a categorical status of the term "transformation". This paper presents the conceptual analysis of transformation based on the theory of form employed in the influential essays by Aristotle and Thomas Aquinas. In the present work the transformation as a method of shaping design has been explored as well as potential application of this term in design has been demonstrated.
Transformation Methods for Using Combination of Remotely Sensed Data and Cadastral Maps
NASA Astrophysics Data System (ADS)
Dönmez, Ş. Ö.; Tunc, A.
2016-06-01
In order to examine using cadastral maps as base maps for aerial orthophotos, two different 2D transformation methods were applied between various coordinate systems. Study area was chosen from Kagithane district in Istanbul. The used data is an orthophoto (30 cm spatial resolution), and cadastral map (1:1000) taken from land office, containing the same region. Transformation methods are chosen as; 1st Order Polynomial Transformation and Helmert 2D Transformation within this study. The test points, used to determine the coefficients between the datums, were 26 common traverse points and the check points, used to compare the transformed coordinates to reliable true coordinates, were 10 common block corners. The transformation methods were applied using Matlab software. After applying the methods, residuals were calculated and compared between each transformation method in order to use cadastral maps as reliable vector data.
Methods for performing fast discrete curvelet transforms of data
Candes, Emmanuel; Donoho, David; Demanet, Laurent
2010-11-23
Fast digital implementations of the second generation curvelet transform for use in data processing are disclosed. One such digital transformation is based on unequally-spaced fast Fourier transforms (USFFT) while another is based on the wrapping of specially selected Fourier samples. Both digital transformations return a table of digital curvelet coefficients indexed by a scale parameter, an orientation parameter, and a spatial location parameter. Both implementations are fast in the sense that they run in about O(n.sup.2 log n) flops for n by n Cartesian arrays or about O(N log N) flops for Cartesian arrays of size N=n.sup.3; in addition, they are also invertible, with rapid inversion algorithms of about the same complexity.
Apparatus and methods for continuous beam fourier transform mass spectrometry
McLuckey, Scott A.; Goeringer, Douglas E.
2002-01-01
A continuous beam Fourier transform mass spectrometer in which a sample of ions to be analyzed is trapped in a trapping field, and the ions in the range of the mass-to-charge ratios to be analyzed are excited at their characteristic frequencies of motion by a continuous excitation signal. The excited ions in resonant motions generate real or image currents continuously which can be detected and processed to provide a mass spectrum.
An improved method for the enzymatic transformation of nucleosides into 5'-monophosphates.
Barai, Vladimir N; Kvach, Sergei V; Zinchenko, Anatoli I; Mikhailopulo, Igor A
2004-12-01
An improved method to transform nucleosides into 5'-monophosphates using nucleoside phosphotransferase from Erwinia herbicola is reported. The method is based on the shift in the equilibrium state of the reaction to the formation of desired product due to its precipitation by Zn2+. Under optimal conditions, the extent of nucleoside transformations into nucleoside-5'-monophosphates were 41-91% (mol). PMID:15672226
ERIC Educational Resources Information Center
Grimm, C. A.
This document contains two units that examine integral transforms and series expansions. In the first module, the user is expected to learn how to use the unified method presented to obtain Laplace transforms, Fourier transforms, complex Fourier series, real Fourier series, and half-range sine series for given piecewise continuous functions. In…
A method of real-time fault diagnosis for power transformers based on vibration analysis
NASA Astrophysics Data System (ADS)
Hong, Kaixing; Huang, Hai; Zhou, Jianping; Shen, Yimin; Li, Yujie
2015-11-01
In this paper, a novel probability-based classification model is proposed for real-time fault detection of power transformers. First, the transformer vibration principle is introduced, and two effective feature extraction techniques are presented. Next, the details of the classification model based on support vector machine (SVM) are shown. The model also includes a binary decision tree (BDT) which divides transformers into different classes according to health state. The trained model produces posterior probabilities of membership to each predefined class for a tested vibration sample. During the experiments, the vibrations of transformers under different conditions are acquired, and the corresponding feature vectors are used to train the SVM classifiers. The effectiveness of this model is illustrated experimentally on typical in-service transformers. The consistency between the results of the proposed model and the actual condition of the test transformers indicates that the model can be used as a reliable method for transformer fault detection.
ERIC Educational Resources Information Center
Savoye, Philippe
2009-01-01
In recent years, I started covering difference equations and z transform methods in my introductory differential equations course. This allowed my students to extend the "classical" methods for (ordinary differential equation) ODE's to discrete time problems arising in many applications.
NASA Astrophysics Data System (ADS)
Gökdoğan, Ahmet; Merdan, Mehmet; Yildirim, Ahmet
2012-01-01
The goal of this study is presented a reliable algorithm based on the standard differential transformation method (DTM), which is called the multi-stage differential transformation method (MsDTM) for solving Hantavirus infection model. The results obtanied by using MsDTM are compared to those obtained by using the Runge-Kutta method (R-K-method). The proposed technique is a hopeful tool to solving for a long time intervals in this kind of systems.
Lin, Chin-Feng; Zhu, Jin-De
2012-03-01
Hilbert-Huang transformation, wavelet transformation, and Fourier transformation are the principal time-frequency analysis methods. These transformations can be used to discuss the frequency characteristics of linear and stationary signals, the time-frequency features of linear and non-stationary signals, the time-frequency features of non-linear and non-stationary signals, respectively. The Hilbert-Huang transformation is a combination of empirical mode decomposition and Hilbert spectral analysis. The empirical mode decomposition uses the characteristics of signals to adaptively decompose them to several intrinsic mode functions. Hilbert transforms are then used to transform the intrinsic mode functions into instantaneous frequencies, to obtain the signal's time-frequency-energy distributions and features. Hilbert-Huang transformation-based time-frequency analysis can be applied to natural physical signals such as earthquake waves, winds, ocean acoustic signals, mechanical diagnosis signals, and biomedical signals. In previous studies, we examined Hilbert-Huang transformation-based time-frequency analysis of the electroencephalogram FPI signals of clinical alcoholics, and 'sharp I' wave-based Hilbert-Huang transformation time-frequency features. In this paper, we discuss the application of Hilbert-Huang transformation-based time-frequency analysis to biomedical signals, such as electroencephalogram, electrocardiogram signals, electrogastrogram recordings, and speech signals. PMID:22558835
Cell classification by moments and continuous wavelet transform methods
Chen, Qian; Fan, Yuan; Udpa, Lalita; Ayres, Virginia M
2007-01-01
Image processing techniques are bringing new insights to biomedical research. The automatic recognition and classification of biomedical objects can enhance work efficiency while identifying new inter-relationships among biological features. In this work, a simple rule-based decision tree classifier is developed to classify typical features of mixed cell types investigated by atomic force microscopy (AFM). A combination of continuous wavelet transform (CWT) and moment-based features are extracted from the AFM data to represent that shape information of different cellular objects at multiple resolution levels. The features are shown to be invariant under operations of translation, rotation, and scaling. The features are then used in a simple rule-based classifier to discriminate between anucleate versus nucleate cell types or to distinguish cells from a fibrous environment such as a tissue scaffold or stint. Since each feature has clear physical meaning, the decision rule of this tree classifier is simple, which makes it very suitable for online processing. Experimental results on AFM data confirm that the performance of this classifier is robust and reliable. PMID:17722546
Design of piezoelectric transformer for DC/DC converter with stochastic optimization method
NASA Astrophysics Data System (ADS)
Vasic, Dejan; Vido, Lionel
2016-04-01
Piezoelectric transformers were adopted in recent year due to their many inherent advantages such as safety, no EMI problem, low housing profile, and high power density, etc. The characteristics of the piezoelectric transformers are well known when the load impedance is a pure resistor. However, when piezoelectric transformers are used in AC/DC or DC/DC converters, there are non-linear electronic circuits connected before and after the transformer. Consequently, the output load is variable and due to the output capacitance of the transformer the optimal working point change. This paper starts from modeling a piezoelectric transformer connected to a full wave rectifier in order to discuss the design constraints and configuration of the transformer. The optimization method adopted here use the MOPSO algorithm (Multiple Objective Particle Swarm Optimization). We start with the formulation of the objective function and constraints; then the results give different sizes of the transformer and the characteristics. In other word, this method is looking for a best size of the transformer for optimal efficiency condition that is suitable for variable load. Furthermore, the size and the efficiency are found to be a trade-off. This paper proposes the completed design procedure to find the minimum size of PT in need. The completed design procedure is discussed by a given specification. The PT derived from the proposed design procedure can guarantee both good efficiency and enough range for load variation.
Transforming student's discourse as a method of teaching science inquiry
NASA Astrophysics Data System (ADS)
Livingston, David
2005-07-01
A qualitative case study on the instructional practice of one secondary science teacher addresses the persistent reluctance of many science teachers to integrate the cultural resources and social practices of professional science communities into the science content they teach. The literature has shown that teachers' hesitation to implement a social and locally situated learning strategy curtails students' ability to draw upon the language of science necessary to co-construct and shape authentic science inquiry and in particular appropriate argument schemes. The study hypothesized that a teacher's dialogic facilitation of a particular social context and instructional practices enhances a students' ability to express verbally the claims and warrants that rise from evidence taken from their inquiries of natural phenomena. The study also tracks students' use of the Key Words and Ideas of this science curriculum for the purpose of assessing the degree of students' assimilation of these terms into their speech and written expressions of inquiry. The theoretical framework is Vygotskian (1978) and the analysis of the qualitative data is founded on Toulmin (1958), Walton (1996), Jimenez-Alexandre et al. (2000) and Shavelson (1996). The dialogic structure of this teacher's facilitation of student's science knowledge is shown to utilize students' presumptive statements to hone their construction of inductive or deductive arguments. This instructional practice may represent teacher-student activity within the zone of proximal development and supports Vygotsky's notion that a knowledgeable other is instrumental in transforming student's spontaneous talk into scientific speech. The tracking of the curriculum's Key Words and Ideas into students' speech and writing indicated that this teachers' ability to facilitate students' presumptuous reasoning into logic statements did not necessarily guarantee that they could post strong written expressions of this verbal know-how in
Using generalized Cayley transformations within an inexact rational Krylov sequence method.
Lehoucq, R. B.; Meerbergen, K.; Mathematics and Computer Science; Utrecht Univ.
1999-01-01
The rational Krylov sequence (RKS) method is a generalization of Arnoldi's method. It constructs an orthogonal reduction of a matrix pencil into an upper Hessenberg pencil. The RKS method is useful when the matrix pencil may be efficiently factored. This article considers approximately solving the resulting linear systems with iterative methods. We show that a Cayley transformation leads to a more efficient and robust eigensolver than the usual shift-invert transformation when the linear systems are solved inexactly within the RKS method. A relationship with the recently introduced Jacobi--Davidson method is also established.
Solution of the Time-Dependent Schrödinger Equation by the Laplace Transform Method
Lin, S. H.; Eyring, H.
1971-01-01
The time-dependent Schrödinger equation for two quite general types of perturbation has been solved by introducing the Laplace transforms to eliminate the time variable. The resulting time-independent differential equation can then be solved by the perturbation method, the variation method, the variation-perturbation method, and other methods. PMID:16591898
Described are methods to measure the polychlorinated biphenyl (PCB) emissions from the stacks of municipal waste, industrial waste, and sewage sludge incinerators and from capacitor and transformer filling plants. The PCB emissions from the incineration plants are collected by im...
Transformational Teaching: Theoretical Underpinnings, Basic Principles, and Core Methods
ERIC Educational Resources Information Center
Slavich, George M.; Zimbardo, Philip G.
2012-01-01
Approaches to classroom instruction have evolved considerably over the past 50 years. This progress has been spurred by the development of several learning principles and methods of instruction, including active learning, student-centered learning, collaborative learning, experiential learning, and problem-based learning. In the present paper, we…
Two-dimensional cylindrical thermal cloak designed by implicit transformation method
NASA Astrophysics Data System (ADS)
Yuan, Xuebo; Lin, Guochang; Wang, Youshan
2016-07-01
As a new-type technology of heat management, thermal metamaterials have attracted more and more attentions recently and thermal cloak is a typical case. Thermal conductivity of thermal cloak designed by coordinate transformation method is usually featured by inhomogeneity, anisotropy and local singularity. Explicit transformation method, which is commonly used to design thermal cloak with the coordinate transformation known in advance, has insufficient flexibility, making it hard to proactively reduce the difficulty of device fabrication. In this work, we designed the thermal conductivity of two-dimensional (2D) cylindrical thermal cloak using the implicit transformation method without knowledge of the coordinate transformation in advance. With two classes of generation functions taken into consideration, this study adopted full-wave simulations to analyze the thermal cloaking performances of designed thermal cloaks. Material distributions and simulation results showed that the implicit transformation method has high flexibility. The form of coordinate transformation not only influences the homogeneity and anisotropy but also directly influences the thermal cloaking performance. An improved layered structure for 2D cylindrical thermal cloak was put forward based on the generation function g(r) = r15, which reduces the number of the kinds of constituent materials while guaranteeing good thermal cloaking performance. This work provides a beneficial guidance for reducing the fabrication difficulty of thermal cloak.
Advantages of Analytical Transformations in Monte Carlo Methods for Radiation Transport
McKinley, M S; Brooks III, E D; Daffin, F
2004-12-13
Monte Carlo methods for radiation transport typically attempt to solve an integral by directly sampling analog or weighted particles, which are treated as physical entities. Improvements to the methods involve better sampling, probability games or physical intuition about the problem. We show that significant improvements can be achieved by recasting the equations with an analytical transform to solve for new, non-physical entities or fields. This paper looks at one such transform, the difference formulation for thermal photon transport, showing a significant advantage for Monte Carlo solution of the equations for time dependent transport. Other related areas are discussed that may also realize significant benefits from similar analytical transformations.
Rapid DNA transformation in Salmonella Typhimurium by the hydrogel exposure method.
Elabed, Hamouda; Hamza, Rim; Bakhrouf, Amina; Gaddour, Kamel
2016-07-01
Even with advances in molecular cloning and DNA transformation, new or alternative methods that permit DNA penetration in Salmonella enterica subspecies enterica serovar Typhimurium are required in order to use this pathogen in biotechnological or medical applications. In this work, an adapted protocol of bacterial transformation with plasmid DNA based on the "Yoshida effect" was applied and optimized on Salmonella enterica serovar Typhimurium LT2 reference strain. The plasmid transference based on the use of sepiolite as acicular materials to promote cell piercing via friction forces produced by spreading on the surface of a hydrogel. The transforming mixture containing sepiolite nanofibers, bacterial cells to be transformed and plasmid DNA were plated directly on selective medium containing 2% agar. In order to improve the procedure, three variables were tested and the transformation of Salmonella cells was accomplished using plasmids pUC19 and pBR322. Using the optimized protocol on Salmonella LT2 strain, the efficiency was about 10(5) transformed cells per 10(9) subjected to transformation with 0.2μg plasmid DNA. In summary, the procedure is fast, offers opportune efficiency and promises to become one of the widely used transformation methods in laboratories. PMID:27154729
Liu, Bailing; Zhang, Fumin; Qu, Xinghua; Shi, Xiaojia
2016-01-01
Coordinate transformation plays an indispensable role in industrial measurements, including photogrammetry, geodesy, laser 3-D measurement and robotics. The widely applied methods of coordinate transformation are generally based on solving the equations of point clouds. Despite the high accuracy, this might result in no solution due to the use of ill conditioned matrices. In this paper, a novel coordinate transformation method is proposed, not based on the equation solution but based on the geometric transformation. We construct characteristic lines to represent the coordinate systems. According to the space geometry relation, the characteristic line scan is made to coincide by a series of rotations and translations. The transformation matrix can be obtained using matrix transformation theory. Experiments are designed to compare the proposed method with other methods. The results show that the proposed method has the same high accuracy, but the operation is more convenient and flexible. A multi-sensor combined measurement system is also presented to improve the position accuracy of a robot with the calibration of the robot kinematic parameters. Experimental verification shows that the position accuracy of robot manipulator is improved by 45.8% with the proposed method and robot calibration. PMID:26901203
FFT-enhanced IHS transform method for fusing high-resolution satellite images
Ling, Y.; Ehlers, M.; Usery, E.L.; Madden, M.
2007-01-01
Existing image fusion techniques such as the intensity-hue-saturation (IHS) transform and principal components analysis (PCA) methods may not be optimal for fusing the new generation commercial high-resolution satellite images such as Ikonos and QuickBird. One problem is color distortion in the fused image, which causes visual changes as well as spectral differences between the original and fused images. In this paper, a fast Fourier transform (FFT)-enhanced IHS method is developed for fusing new generation high-resolution satellite images. This method combines a standard IHS transform with FFT filtering of both the panchromatic image and the intensity component of the original multispectral image. Ikonos and QuickBird data are used to assess the FFT-enhanced IHS transform method. Experimental results indicate that the FFT-enhanced IHS transform method may improve upon the standard IHS transform and the PCA methods in preserving spectral and spatial information. ?? 2006 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).
Liu, Bailing; Zhang, Fumin; Qu, Xinghua; Shi, Xiaojia
2016-01-01
Coordinate transformation plays an indispensable role in industrial measurements, including photogrammetry, geodesy, laser 3-D measurement and robotics. The widely applied methods of coordinate transformation are generally based on solving the equations of point clouds. Despite the high accuracy, this might result in no solution due to the use of ill conditioned matrices. In this paper, a novel coordinate transformation method is proposed, not based on the equation solution but based on the geometric transformation. We construct characteristic lines to represent the coordinate systems. According to the space geometry relation, the characteristic line scan is made to coincide by a series of rotations and translations. The transformation matrix can be obtained using matrix transformation theory. Experiments are designed to compare the proposed method with other methods. The results show that the proposed method has the same high accuracy, but the operation is more convenient and flexible. A multi-sensor combined measurement system is also presented to improve the position accuracy of a robot with the calibration of the robot kinematic parameters. Experimental verification shows that the position accuracy of robot manipulator is improved by 45.8% with the proposed method and robot calibration. PMID:26901203
Methods for transforming and expression screening of filamentous fungal cells with a DNA library
Teter, Sarah; Lamsa, Michael; Cherry, Joel; Ward, Connie
2015-06-02
The present invention relates to methods for expression screening of filamentous fungal transformants, comprising: (a) isolating single colony transformants of a DNA library introduced into E. coli; (b) preparing DNA from each of the single colony E. coli transformants; (c) introducing a sample of each of the DNA preparations of step (b) into separate suspensions of protoplasts of a filamentous fungus to obtain transformants thereof, wherein each transformant contains one or more copies of an individual polynucleotide from the DNA library; (d) growing the individual filamentous fungal transformants of step (c) on selective growth medium, thereby permitting growth of the filamentous fungal transformants, while suppressing growth of untransformed filamentous fungi; and (e) measuring activity or a property of each polypeptide encoded by the individual polynucleotides. The present invention also relates to isolated polynucleotides encoding polypeptides of interest obtained by such methods, to nucleic acid constructs, expression vectors, and recombinant host cells comprising the isolated polynucleotides, and to methods of producing the polypeptides encoded by the isolated polynucleotides.
A method to analyze molecular tagging velocimetry data using the Hough transform
NASA Astrophysics Data System (ADS)
Sanchez-Gonzalez, R.; McManamen, B.; Bowersox, R. D. W.; North, S. W.
2015-10-01
The development of a method to analyze molecular tagging velocimetry data based on the Hough transform is presented. This method, based on line fitting, parameterizes the grid lines "written" into a flowfield. Initial proof-of-principle illustration of this method was performed to obtain two-component velocity measurements in the wake of a cylinder in a Mach 4.6 flow, using a data set derived from computational fluid dynamics simulations. The Hough transform is attractive for molecular tagging velocimetry applications since it is capable of discriminating spurious features that can have a biasing effect in the fitting process. Assessment of the precision and accuracy of the method were also performed to show the dependence on analysis window size and signal-to-noise levels. The accuracy of this Hough transform-based method to quantify intersection displacements was determined to be comparable to cross-correlation methods. The employed line parameterization avoids the assumption of linearity in the vicinity of each intersection, which is important in the limit of drastic grid deformations resulting from large velocity gradients common in high-speed flow applications. This Hough transform method has the potential to enable the direct and spatially accurate measurement of local vorticity, which is important in applications involving turbulent flowfields. Finally, two-component velocity determinations using the Hough transform from experimentally obtained images are presented, demonstrating the feasibility of the proposed analysis method.
A method to analyze molecular tagging velocimetry data using the Hough transform.
Sanchez-Gonzalez, R; McManamen, B; Bowersox, R D W; North, S W
2015-10-01
The development of a method to analyze molecular tagging velocimetry data based on the Hough transform is presented. This method, based on line fitting, parameterizes the grid lines "written" into a flowfield. Initial proof-of-principle illustration of this method was performed to obtain two-component velocity measurements in the wake of a cylinder in a Mach 4.6 flow, using a data set derived from computational fluid dynamics simulations. The Hough transform is attractive for molecular tagging velocimetry applications since it is capable of discriminating spurious features that can have a biasing effect in the fitting process. Assessment of the precision and accuracy of the method were also performed to show the dependence on analysis window size and signal-to-noise levels. The accuracy of this Hough transform-based method to quantify intersection displacements was determined to be comparable to cross-correlation methods. The employed line parameterization avoids the assumption of linearity in the vicinity of each intersection, which is important in the limit of drastic grid deformations resulting from large velocity gradients common in high-speed flow applications. This Hough transform method has the potential to enable the direct and spatially accurate measurement of local vorticity, which is important in applications involving turbulent flowfields. Finally, two-component velocity determinations using the Hough transform from experimentally obtained images are presented, demonstrating the feasibility of the proposed analysis method. PMID:26520983
Refined Fourier-transform method of analysis of full two-dimensional digitized interferograms
NASA Astrophysics Data System (ADS)
Lovrić, Davorin; Vučić, Zlatko; Gladić, Jadranko; Demoli, Nazif; Mitrović, Slobodan; Milas, Mirko
2003-03-01
A refined Fourier-transform method of analysis of interference patterns is presented. The refinements include a method of automatic background subtraction and a way of treating the problem of heterodyning. The method proves particularly useful for analysis of long sequences of interferograms.
NASA Astrophysics Data System (ADS)
Tian, Jiangxue; Qi, Lin; Wang, Yaxing
2015-12-01
As one of classic methods of frequency domain based saliency detection, Spectral residual (SR) method has shown several advantages. However, it usually produces higher saliency values at object edges instead of generating maps that uniformly cover the whole object, which results from failing to exploit all the spatial frequency content of the original image. The Two-Dimensional Fractional Fourier transform (2D-FRFT) is a generalized form of the traditional Fourier Transform (FT) which can abstract more meaningful information of the image under certain conditions. Based on this property, we propose a new method which detects the salient region based on 2D-FRFT domain. Moreover, we also use Hough transform detection and a band-pass filter to refine the saliency map. We conduct experiments on a common used dataset: MSRA. The proposed method is compared with several other saliency detection methods and shown to achieve superior result.
Latifoğlu, Fatma; Kara, Sadik; Imal, Erkan
2009-06-01
In this paper, a more effective use of Doppler techniques is presented for the purpose of diagnosing atherosclerosis in its early stages using the carotid artery Doppler signals. The power spectral density (PSD) graphics are obtained by applying the short-time Fourier transform (STFT)-Welch and the Eigenvector MUSIC methods to the discrete wavelet transform (DWT) of Doppler signals. The PSDs for the fourth approximation component (A4) of both methods estimated that the patients with atherosclerosis in its early phase had lower maximum frequency components. On the other hand, the healthy subjects had higher maximum frequency components. The area under the curve (AUC), which belongs to the receiver operating characteristic (ROC) curve for the frequency level of the maximum PSDs of the A4 approximation obtained from the STFT modeling, is computed as 0.97. The AUC for the MUSIC modeling is computed as 0.996. The AUC belonging to the ROC curve for the higher maximum frequency component is computed as 0.87. The AUC belonging to the ROC curve for the test parameter of the frequency level of the maximum PSDs derived from the MUSIC modeling is determined to be 0.882. The results of this study clearly demonstrate that it is possible to distinguish between the healthy people and the patients with atherosclerosis by using the frequency level of the maximum PSDs for the A4 approximation. Furthermore, it is concluded that the power of Eigenvector-MUSIC method in terms of the resolution of the high frequencies is better than that of the STFT methods. PMID:19408452
Canonical Lie-transform method in Hamiltonian gyrokinetics: a new approach
Nicolini, Piero; Tessarotto, Massimo
2005-05-16
The well-known gyrokinetic problem regards the perturbative expansion related to the dynamics of a charged particle subject to fast gyration motion due to the presence of a strong magnetic field. Although a variety of approaches have been formulated in the past to this well known problem, surprisingly a purely canonical approach based on Lie transform methods is still missing. This paper aims to fill in this gap and provide at the same time new insight in Lie-transform approaches.
Kim, Sora; Lee, Young-Chul; Cho, Dae-Hyun; Lee, Hyun Uk; Huh, Yun Suk; Kim, Geun-Joong; Kim, Hee-Sik
2014-01-01
Genetic engineering in microalgae is gaining attraction but nuclear transformation methods available so far are either inefficient or require special equipment. In this study, we employ positively charged nanoparticles, 3-aminopropyl-functionalized magnesium phyllosilicate (aminoclay, approximate unit cell composition of [H2N(CH2)3]8Si8Mg6O12(OH)4), for nuclear transformation into eukaryotic microalgae. TEM and EDX analysis of the process of transformation reveals that aminoclay coats negatively-charged DNA biomolecules and forms a self-assembled hybrid nanostructure. Subsequently, when this nanostructure is mixed with microalgal cells and plated onto selective agar plates with high friction force, cell wall is disrupted facilitating delivery of plasmid DNA into the cell and ultimately to the nucleus. This method is not only simple, inexpensive, and non-toxic to cells but also provides efficient transformation (5.03×102 transformants/µg DNA), second only to electroporation which needs advanced instrumentation. We present optimized parameters for efficient transformation including pre-treatment, friction force, concentration of foreign DNA/aminoclay, and plasticity of agar plates. It is also confirmed the successful integration and stable expression of foreign gene in Chlamydomonas reinhardtii through molecular methods. PMID:24988123
[Research on spatially modulated Fourier transform imaging spectrometer data processing method].
Huang, Min; Xiangli, Bin; Lü, Qun-Bo; Zhou, Jin-Song; Jing, Juan-Juan; Cui, Yan
2010-03-01
Fourier transform imaging spectrometer is a new technic, and has been developed very rapidly in nearly ten years. The data catched by Fourier transform imaging spectrometer is indirect data, can not be used by user, and need to be processed by various approaches, including data pretreatment, apodization, phase correction, FFT, and spectral radicalization calibration. No paper so far has been found roundly to introduce this method. In the present paper, the author will give an effective method to process the interfering data to spectral data, and with this method we can obtain good result. PMID:20496726
In planta transformation method for T-DNA transfer in orchids
NASA Astrophysics Data System (ADS)
Semiarti, Endang; Purwantoro, Aziz; Mercuriani, Ixora S.; Anggriasari, Anida M.; Jang, Seonghoe; Suhandono, Sony; Machida, Yasunori; Machida, Chiyoko
2014-03-01
Transgenic plant technology is an efficient tool to study the function of gene(s) in plant. The most popular and widely used technique is Agrobacterium-mediated transformation in which cocultivation was done by immersing the plant tissues/organ in overnight bacterial cultured for about 30 minutes to one hour under in vitro condition. In this experiment, we developed more easier technique that omitted the in vitro step during cocultivation with Agrobacterium, namely in planta transformation method. Pollinaria (compact pollen mass of orchid) of Phalaenopsis amabilis and Spathoglottis plicata orchids were used as target explants that were immersed into bacterial culture for 30 minutes, then dried up the pollinaria, the transformed pollinaria was used to pollinate orchid flowers. The T-DNA used for this experiments were Ubipro∷PaFT/A. tumefaciens GV3101 for P. amabilis and MeEF1α2 pro∷GUS/ A. tumefaciens LBA 4404 for S.plicata. Seeds that were produced from pollinated flowers were grown onto 10 mg/l hygromicin containing NP (New Phalaenopsis) medium. The existance of transgene in putative transformant protocorm (developing orchid embryo) genome was confirmed using PCR with specific primers of either PaFT or GUS genes. Histochemical GUS assay was also performed to the putative transformants. The result showed that transformation frequencies were 2.1 % in P. amabilis, and 0,53% in S. plicata. These results indicates that in planta transformation method could be used for Agrobacterium-mediated genetic transformation, with advantage easier and more secure work from contaminants than that of the in vitro method.
A simple bacterial transformation method using magnesium- and calcium-aminoclays.
Choi, Hyoung-An; Lee, Young-Chul; Lee, Jin-Young; Shin, Hyun-Jae; Han, Hyo-Kyung; Kim, Geun-Joong
2013-11-01
An efficient and user-friendly bacterial transformation method by simple spreading cells with aminoclays was demonstrated. Compared to the reported transformation approaches using DNA adsorption or wrapping onto (in)organic fibers, the spontaneously generated clay-coated DNA suprastructures by mixing DNA with aminoclay resulted in transformants in both Gram-negative (Escherichia coli) and Gram-positive cells (Streptococcus mutans). Notably, the wild type S. mutans showed comparable transformation efficiency to that of the E. coli host for recombinant DNA cloning. This is a potentially promising result because other trials such as heat-shock, electroporation, and treatment with sepiolite for introducing DNA into the wild type S. mutans failed. Under defined conditions, the transformation efficiency of E. coli XL1-Blue and S. mutans exhibited ~2 × 10(5) and ~6 × 10(3)CFU/μg of plasmid DNA using magnesium-aminoclay. In contrast, transformation efficiency was higher in S. mutans than that in E. coli XL1-Blue for calcium-aminoclay. It was also confirmed that each plasmid transformed into E. coli and S. mutans was stably maintained and that they expressed the inserted gene encoding the green fluorescent protein during prolonged growth of up to 80 generations. PMID:23911572
Jing, Juan-Juan; Zhou, Jin-Song; Xiangli, Bin; Lü, Qun-Bo; Wei, Ru-Yi
2010-06-01
The principle of reflecting rotating Fourier transform spectrometer was introduced in the present paper. The nonlinear problem of optical path difference (OPD) of rotating Fourier transform spectrometer universally exists, produced by the rotation of rotating mirror. The nonlinear OPD will lead to fictitious recovery spectrum, so it is necessary to compensate the nonlinear OPD. Three methods of correction for the nonlinear OPD were described and compared in this paper, namely NUFFT method, OPD replace method and interferograms fitting method. The result indicates that NUFFT was the best method for the compensation of nonlinear OPD, OPD replace method was better, its precision was almost the same as NUFFT method, and their relative error are superior to 0.13%, but the computation efficiency of OPD replace method is slower than NUFFT method, while the precision and computation efficiency of interferograms fitting method are not so satisfied, because the interferograms are rapid fluctuant especially around the zero optical path difference, so it is unsuitable for polynomial fitting, and because this method needs piecewise fitting, its computation efficiency is the slowest, thus the NUFFT method is the most suited method for the nonlinear OPD compensation of reflecting rotating Fourier transform spectrometer. PMID:20707175
A new Sumudu transform iterative method for time-fractional Cauchy reaction-diffusion equation.
Wang, Kangle; Liu, Sanyang
2016-01-01
In this paper, a new Sumudu transform iterative method is established and successfully applied to find the approximate analytical solutions for time-fractional Cauchy reaction-diffusion equations. The approach is easy to implement and understand. The numerical results show that the proposed method is very simple and efficient. PMID:27386314
Technology Transfer Automated Retrieval System (TEKTRAN)
A new chemometric method based on absorbance ratios from Fourier transform infrared spectra was devised to analyze multicomponent biodegradable plastics. The method uses the BeerLambert law to directly compute individual component concentrations and weight losses before and after biodegradation of c...
ERIC Educational Resources Information Center
Butler, Brandon M.; Suh, Yonghee; Scott, Wendy
2015-01-01
In this article, the authors investigate the extent to which 9 elementary social studies methods textbooks present the purpose of teaching and learning social studies. Using Stanley's three perspectives of teaching social studies for knowledge transmission, method of intelligence, and social transformation; we analyze how these texts prepare…
Chen, Xi; Stone, Michelle; Schlagnhaufer, Carl; Romaine, C. Peter
2000-01-01
We describe a modified Agrobacterium-mediated method for the efficient transformation of Agaricus bisporus. Salient features of this procedure include cocultivation of Agrobacterium and fruiting body gill tissue and use of a vector with a homologous promoter. This method offers new prospects for the genetic manipulation of this commercially important mushroom species. PMID:11010906
Comparative analysis of direct and "step-by-step" Foldy-Wouthuysen transformation methods
NASA Astrophysics Data System (ADS)
Silenko, A. Ya.
2013-08-01
Relativistic methods for the Foldy-Wouthuysen transformation of the "step-by-step" type already at the first step give an expression for the Hamilton operator not coinciding with the exact result determined by the Eriksen method. The methods agree for the zeroth and first orders in the Planck constant terms but do not agree for the second and higher-order terms. We analyze the benefits and drawbacks of various methods and establish their applicability boundaries.
A depth estimation method based on geometric transformation for stereo light microscope.
Fan, Shengli; Yu, Mei; Wang, Yigang; Jiang, Gangyi
2014-01-01
Stereo light microscopes (SLM) with narrow vision and shallow depth of field are widely used in micro-domain research. In this paper, we propose a depth estimation method of micro objects based on geometric transformation. By analyzing the optical imaging geometry, the definition of geometric transformation distance is given and the depth-distance relation express is obtained. The parameters of geometric transformation and express are calibrated with calibration board images captured in aid of precise motorized stage. The depth of micro object can be estimated by calculating the geometric transformation distance. The proposed depth-distance relation express is verified using an experiment in which the depth map of an Olanzapine tablet surface is reconstructed. PMID:25226979
NASA Astrophysics Data System (ADS)
Olsen, Jeppe
2014-07-01
A novel algorithm is introduced for the transformation of wave functions between the bases of Slater determinants (SD) and configuration state functions (CSF) in the genealogical coupling scheme. By modifying the expansion coefficients as each electron is spin-coupled, rather than performing a single many-electron transformation, the large transformation matrix that plagues previous approaches is avoided and the required number of operations is drastically reduced. As an example of the efficiency of the algorithm, the transformation for a configuration with 30 unpaired electrons and singlet spin is discussed. For this case, the 10 × 106 coefficients in the CSF basis is obtained from the 150 × 106 coefficients in the SD basis in 1 min, which should be compared with the seven years that the previously employed method is estimated to require.
Olsen, Jeppe
2014-07-21
A novel algorithm is introduced for the transformation of wave functions between the bases of Slater determinants (SD) and configuration state functions (CSF) in the genealogical coupling scheme. By modifying the expansion coefficients as each electron is spin-coupled, rather than performing a single many-electron transformation, the large transformation matrix that plagues previous approaches is avoided and the required number of operations is drastically reduced. As an example of the efficiency of the algorithm, the transformation for a configuration with 30 unpaired electrons and singlet spin is discussed. For this case, the 10 × 10(6) coefficients in the CSF basis is obtained from the 150 × 10(6) coefficients in the SD basis in 1 min, which should be compared with the seven years that the previously employed method is estimated to require. PMID:25053306
Olsen, Jeppe
2014-07-21
A novel algorithm is introduced for the transformation of wave functions between the bases of Slater determinants (SD) and configuration state functions (CSF) in the genealogical coupling scheme. By modifying the expansion coefficients as each electron is spin-coupled, rather than performing a single many-electron transformation, the large transformation matrix that plagues previous approaches is avoided and the required number of operations is drastically reduced. As an example of the efficiency of the algorithm, the transformation for a configuration with 30 unpaired electrons and singlet spin is discussed. For this case, the 10 × 10{sup 6} coefficients in the CSF basis is obtained from the 150 × 10{sup 6} coefficients in the SD basis in 1 min, which should be compared with the seven years that the previously employed method is estimated to require.
Ntsama, Eloundou Pascal; Colince, Welba; Ele, Pierre
2016-01-01
In this article, we make a comparative study for a new approach compression between discrete cosine transform (DCT) and discrete wavelet transform (DWT). We seek the transform proper to vector quantization to compress the EMG signals. To do this, we initially associated vector quantization and DCT, then vector quantization and DWT. The coding phase is made by the SPIHT coding (set partitioning in hierarchical trees coding) associated with the arithmetic coding. The method is demonstrated and evaluated on actual EMG data. Objective performance evaluations metrics are presented: compression factor, percentage root mean square difference and signal to noise ratio. The results show that method based on the DWT is more efficient than the method based on the DCT. PMID:27104132
NASA Astrophysics Data System (ADS)
He, Qian; Wang, Guangping; Wu, Jingli; Li, Junwei
2014-11-01
As the impact of the instrument internal error, external interference and other factors, the interferogram measured by Fourier transform spectrometer is asymmetric, result in the complex outcome after Fourier transform. Currently, most radiometric calibration method used for Fourier transform spectrometer is usually based on real spectrums, which is converted from the above complex spectrum by calculating magnitude value or make the phase correction first. Proceed from error sources and mechanisms of the Fourier transform spectrometer, we propose a multi-point radiometric calibration method based on complex spectral data to improve the processing efficiency and accuracy, which is obtained by the original interferogram via Fourier transform. We solving the instrument response function include linear gain and offset by complex spectrum above to calculate complex spectral radiance. Compared with the traditional method based on real spectrum, the present efficient method does not limited to real spectrum and the phase correction is not required. In this paper, we use BOMEM's MR304 Fourier transform infrared spectrometer and the DCN1000N3 blackbody made by HGH Infrared Systems to carry out the radiation calibration experiment in laboratory. The results show that, the amplitude of complex radiance spectrum obtained by this method has a high consistency with the theoretical value, while the extra imaginary spectrum is similar with the difference between results and theoretical value in absolute value and trends. It proved that, this multi-point radiometric calibration method by using the amplitude of complex spectral data is highly reliable; meanwhile, the imaginary spectrum can reflect the calibration error very well and offer a new technical approach for accuracy evaluation research.
A method based on IHS cylindrical transform model for quality assessment of image fusion
NASA Astrophysics Data System (ADS)
Zhu, Xiaokun; Jia, Yonghong
2005-10-01
Image fusion technique has been widely applied to remote sensing image analysis and processing, and methods for quality assessment of image fusion in remote sensing have also become the research issues at home and abroad. Traditional assessment methods combine calculation of quantitative indexes and visual interpretation to compare fused images quantificationally and qualitatively. However, in the existing assessment methods, there are two defects: on one hand, most imdexes lack the theoretic support to compare different fusion methods. On the hand, there is not a uniform preference for most of the quantitative assessment indexes when they are applied to estimate the fusion effects. That is, the spatial resolution and spectral feature could not be analyzed synchronously by these indexes and there is not a general method to unify the spatial and spectral feature assessment. So in this paper, on the basis of the approximate general model of four traditional fusion methods, including Intensity Hue Saturation(IHS) triangle transform fusion, High Pass Filter(HPF) fusion, Principal Component Analysis(PCA) fusion, Wavelet Transform(WT) fusion, a correlation coefficient assessment method based on IHS cylindrical transform is proposed. By experiments, this method can not only get the evaluation results of spatial and spectral features on the basis of uniform preference, but also can acquire the comparison between fusion image sources and fused images, and acquire differences among fusion methods. Compared with the traditional assessment methods, the new methods is more intuitionistic, and in accord with subjective estimation.
Performance comparison of ISAR imaging method based on time frequency transforms
NASA Astrophysics Data System (ADS)
Xie, Chunjian; Guo, Chenjiang; Xu, Jiadong
2013-03-01
Inverse synthetic aperture radar (ISAR) can image the moving target, especially the target in the air, so it is important in the air defence and missile defence system. Time-frequency Transform was applied to ISAR imaging process widely. Several time frequency transforms were introduced. Noise jamming methods were analysed, and when these noise jamming were added to the echo of the ISAR receiver, the image can become blur even can't to be identify. But the effect is different to the different time frequency analysis. The results of simulation experiment show the Performance Comparison of the method.
Xie, Qing; Tao, Junhan; Wang, Yongqiang; Geng, Jianghai; Cheng, Shuyi; Lü, Fangcheng
2014-08-01
Fast and accurate positioning of partial discharge (PD) sources in transformer oil is very important for the safe, stable operation of power systems because it allows timely elimination of insulation faults. There is usually more than one PD source once an insulation fault occurs in the transformer oil. This study, which has both theoretical and practical significance, proposes a method of identifying multiple PD sources in the transformer oil. The method combines the two-sided correlation transformation algorithm in the broadband signal focusing and the modified Gerschgorin disk estimator. The method of classification of multiple signals is used to determine the directions of arrival of signals from multiple PD sources. The ultrasonic array positioning method is based on the multi-platform direction finding and the global optimization searching. Both the 4 × 4 square planar ultrasonic sensor array and the ultrasonic array detection platform are built to test the method of identifying and positioning multiple PD sources. The obtained results verify the validity and the engineering practicability of this method. PMID:25173293
Use of ultrasonic array method for positioning multiple partial discharge sources in transformer oil
NASA Astrophysics Data System (ADS)
Xie, Qing; Tao, Junhan; Wang, Yongqiang; Geng, Jianghai; Cheng, Shuyi; Lü, Fangcheng
2014-08-01
Fast and accurate positioning of partial discharge (PD) sources in transformer oil is very important for the safe, stable operation of power systems because it allows timely elimination of insulation faults. There is usually more than one PD source once an insulation fault occurs in the transformer oil. This study, which has both theoretical and practical significance, proposes a method of identifying multiple PD sources in the transformer oil. The method combines the two-sided correlation transformation algorithm in the broadband signal focusing and the modified Gerschgorin disk estimator. The method of classification of multiple signals is used to determine the directions of arrival of signals from multiple PD sources. The ultrasonic array positioning method is based on the multi-platform direction finding and the global optimization searching. Both the 4 × 4 square planar ultrasonic sensor array and the ultrasonic array detection platform are built to test the method of identifying and positioning multiple PD sources. The obtained results verify the validity and the engineering practicability of this method.
Research of on-line monitoring method for insulation condition of power transformer bushing
NASA Astrophysics Data System (ADS)
Xia, Jiuyun; Qian, Zheng; Yu, Hao; Yao, Junda
2016-01-01
The power transformer is the key equipment of the power system; its insulation condition will directly influence the security and reliability of the power system. Thus, the on-line monitoring of power transformer is urgently required in order to guarantee the normal operation of the power system. Moreover, the dielectric loss factor is a significant parameter reflecting the condition of transformer bushing, so the on-line measurement of dielectric loss factor is really important. In this paper, the phase-to-phase comparison method is selected as the on-line monitoring method based on the overall analysis and discussion of the existing on-line monitoring methods. At first, the harmonic analysis method is utilized to calculate the dielectric loss of each phase of the three-phase transformer bushing, and then the differences of dielectric loss between every two phases are calculated and analyzed. So the insulation condition of each bushing could be achieved based on the careful analysis of different phase-to-phase dielectric loss. The simulation results of phase-to-phase comparison method are carried out in this paper, and the validity is verified. At last, this method is utilized in an actual equipment of on-line monitoring.
Song, Jinzhong; Yan, Hong; Li, Yanjun; Mu, Kaiyu
2010-09-01
Baseline wandering in electrocardiogram (ECG) is one of the biggest interferences in visualization and computerized detection of waveforms (especially ST-segment) based on threshold decision. A new method based on wavelet transform, QRS barycenter fitting and regional method was proposed in this paper. Firstly, wavelet transform as a coarse correction was used to remove the baseline wandering, whose frequency bands were non-overlapping with that of ST-segment. Secondly, QRS barycenter fitting was applied as a detailed correction. The third, the regional method was used to transfer baseline to zero. Finally, the method in this paper was proved to perform better than filtering and function fitting methods in baseline wandering correction after the long-term ST database (LTST) verification. In addition, the proposed method is simple and easy to carry out, and in current use. PMID:20882381
Xie, Lie-Jun; Zhou, Cai-Lian; Xu, Song
2016-01-01
In this work, an effective numerical method is developed to solve a class of singular boundary value problems arising in various physical models by using the improved differential transform method (IDTM). The IDTM applies the Adomian polynomials to handle the differential transforms of the nonlinearities arising in the given differential equation. The relation between the Adomian polynomials of those nonlinear functions and the coefficients of unknown truncated series solution is given by a simple formula, through which one can easily deduce the approximate solution which takes the form of a convergent series. An upper bound for the estimation of approximate error is presented. Several physical problems are discussed as illustrative examples to testify the validity and applicability of the proposed method. Comparisons are made between the present method and the other existing methods. PMID:27462514
Development of Method for Remaining Life Assessment of Oil-Immersed Transformer
NASA Astrophysics Data System (ADS)
Matsui, Tetsuro; Nakahara, Yasuo; Nishiyama, Kazuo; Urabe, Noboru; Itoh, Masayoshi
This paper presents a method for remaining life assessment of oil-immersed transformers using analyzable structured neural networks. Remaining life assessment of oil-immersed transformer is very important. Furfural method is conventionally used for such an assessment. In the furfural method, the average degree of polymerization is determined by considering the nonlinear correlation between the furfural and average degree of polymerization. The remaining life is estimated by considering the average degree of polymerization. However, a range of estimates of the remaining life is obtained when the furfural method is used, making accurate estimation difficult. The proposed method can be used to estimate the remaining life of an oil-immersed transformer accurately; this method involves analyzable structured neural networks and ensemble method. In the proposed method, not only furfural but also oil temperature, operational status, cooling type, etc., are considered. Since various factors are considered as input variables and a nonlinear model, i.e., artificial neural networks are used, accurate estimation of the remaining life has been realized. The effectiveness of the proposed method is shown by numerical simulation using actual measured data.
NASA Astrophysics Data System (ADS)
Bijaoui, A.
2013-03-01
The image restoration is today an important part of the astrophysical data analysis. The denoising and the deblurring can be efficiently performed using multiscale transforms. The multiresolution analysis constitutes the fundamental pillar for these transforms. The discrete wavelet transform is introduced from the theory of the approximation by translated functions. The continuous wavelet transform carries out a generalization of multiscale representations from translated and dilated wavelets. The à trous algorithm furnishes its discrete redundant transform. The image denoising is first considered without any hypothesis on the signal distribution, on the basis of the a contrario detection. Different softening functions are introduced. The introduction of a regularization constraint may improve the results. The application of Bayesian methods leads to an automated adaptation of the softening function to the signal distribution. The MAP principle leads to the basis pursuit, a sparse decomposition on redundant dictionaries. Nevertheless the posterior expectation minimizes, scale per scale, the quadratic error. The proposed deconvolution algorithm is based on a coupling of the wavelet denoising with an iterative inversion algorithm. The different methods are illustrated by numerical experiments on a simulated image similar to images of the deep sky. A white Gaussian stationary noise was added with three levels. In the conclusion different important connected problems are tackled.
NASA Astrophysics Data System (ADS)
Xu, Luopeng; Dan, Youquan; Wang, Qingyuan
2015-10-01
The continuous wavelet transform (CWT) introduces an expandable spatial and frequency window which can overcome the inferiority of localization characteristic in Fourier transform and windowed Fourier transform. The CWT method is widely applied in the non-stationary signal analysis field including optical 3D shape reconstruction with remarkable performance. In optical 3D surface measurement, the performance of CWT for optical fringe pattern phase reconstruction usually depends on the choice of wavelet function. A large kind of wavelet functions of CWT, such as Mexican Hat wavelet, Morlet wavelet, DOG wavelet, Gabor wavelet and so on, can be generated from Gauss wavelet function. However, so far, application of the Gauss wavelet transform (GWT) method (i.e. CWT with Gauss wavelet function) in optical profilometry is few reported. In this paper, the method using GWT for optical fringe pattern phase reconstruction is presented first and the comparisons between real and complex GWT methods are discussed in detail. The examples of numerical simulations are also given and analyzed. The results show that both the real GWT method along with a Hilbert transform and the complex GWT method can realize three-dimensional surface reconstruction; and the performance of reconstruction generally depends on the frequency domain appearance of Gauss wavelet functions. For the case of optical fringe pattern of large phase variation with position, the performance of real GWT is better than that of complex one due to complex Gauss series wavelets existing frequency sidelobes. Finally, the experiments are carried out and the experimental results agree well with our theoretical analysis.
The unified transform method for the Sasa–Satsuma equation on the half-line
Xu, Jian; Fan, Engui
2013-01-01
We implement the unified transform method to the initial-boundary value (IBV) problem of the Sasa–Satsuma equation on the half line. In addition to presenting the basic Riemann–Hilbert formalism, which linearizes this IBV problem, we also analyse the associated general Dirichlet to Neumann map using the so-called global relation. PMID:24204181
ERIC Educational Resources Information Center
Riley, Karen L.; Stern, Barbara Slater
2005-01-01
In this article, the authors focus on the use of Web-based instruction in social studies methods courses. They examine in what ways Web-based instruction transforms both teaching and learning and explore the problems and possibilities involved with electronic classrooms, including Web-supported instruction. Their study is classroom…
The unified transform method for the Sasa-Satsuma equation on the half-line.
Xu, Jian; Fan, Engui
2013-11-01
We implement the unified transform method to the initial-boundary value (IBV) problem of the Sasa-Satsuma equation on the half line. In addition to presenting the basic Riemann-Hilbert formalism, which linearizes this IBV problem, we also analyse the associated general Dirichlet to Neumann map using the so-called global relation. PMID:24204181
A gyrokinetic continuum code based on the numerical Lie transform (NLT) method
NASA Astrophysics Data System (ADS)
Ye, Lei; Xu, Yingfeng; Xiao, Xiaotao; Dai, Zongliang; Wang, Shaojie
2016-07-01
In this work, we report a novel gyrokinetic simulation method named numerical Lie transform (NLT), which depends on a new physical model derived from the I-transform theory. In this model, the perturbed motion of a particle is decoupled from the unperturbed motion. Due to this property, the unperturbed orbit can be computed in advance and saved as numerical tables for real-time computation. A 4D tensor B-spline interpolation module is developed and applied with the semi-Lagrangian scheme to avoid operator splitting. The NLT code is verified by the Rosenbluth-Hinton test and the linear ITG Cyclone test.
Study on identifying deciduous forest by the method of feature space transformation
NASA Astrophysics Data System (ADS)
Zhang, Xuexia; Wu, Pengfei
2009-10-01
The thematic remotely sensed information extraction is always one of puzzling nuts which the remote sensing science faces, so many remote sensing scientists devotes diligently to this domain research. The methods of thematic information extraction include two kinds of the visual interpretation and the computer interpretation, the developing direction of which is intellectualization and comprehensive modularization. The paper tries to develop the intelligent extraction method of feature space transformation for the deciduous forest thematic information extraction in Changping district of Beijing city. The whole Chinese-Brazil resources satellite images received in 2005 are used to extract the deciduous forest coverage area by feature space transformation method and linear spectral decomposing method, and the result from remote sensing is similar to woodland resource census data by Chinese forestry bureau in 2004.
Gu Junhua; Xu Haiguang; Wang Jingying; Chen Wen; An Tao
2013-08-10
We propose a continuous wavelet transform based non-parametric foreground subtraction method for the detection of redshifted 21 cm signal from the epoch of reionization. This method works based on the assumption that the foreground spectra are smooth in frequency domain, while the 21 cm signal spectrum is full of saw-tooth-like structures, thus their characteristic scales are significantly different. We can distinguish them in the wavelet coefficient space easily and perform the foreground subtraction. Compared with the traditional spectral fitting based method, our method is more tolerant to complex foregrounds. Furthermore, we also find that when the instrument has uncorrected response error, our method can also work significantly better than the spectral fitting based method. Our method can obtain similar results with the Wp smoothing method, which is also a non-parametric method, but our method consumes much less computing time.
NASA Astrophysics Data System (ADS)
Gu, Junhua; Xu, Haiguang; Wang, Jingying; An, Tao; Chen, Wen
2013-08-01
We propose a continuous wavelet transform based non-parametric foreground subtraction method for the detection of redshifted 21 cm signal from the epoch of reionization. This method works based on the assumption that the foreground spectra are smooth in frequency domain, while the 21 cm signal spectrum is full of saw-tooth-like structures, thus their characteristic scales are significantly different. We can distinguish them in the wavelet coefficient space easily and perform the foreground subtraction. Compared with the traditional spectral fitting based method, our method is more tolerant to complex foregrounds. Furthermore, we also find that when the instrument has uncorrected response error, our method can also work significantly better than the spectral fitting based method. Our method can obtain similar results with the Wp smoothing method, which is also a non-parametric method, but our method consumes much less computing time.
A rapid and efficient electroporation method for transformation of Halomonas sp. O-1.
Harris, Joshua R; Lundgren, Benjamin R; Grzeskowiak, Brian R; Mizuno, Kouhei; Nomura, Christopher T
2016-10-01
Halomonas sp. O-1 is a halophilic bacterium with a high potential for industrial application due to its natural ability to produce polyhydroxyalkanoates (PHAs) using seawater-based media. However, a major barrier preventing industrial scale implementation of this organism is a lack of molecular methodologies capable of readily transforming members of the Halomonas genus. Currently, the only reliable method used for introducing DNA into Halomonas spp. is bacterial conjugation, a somewhat tedious and time-consuming technique compared to electroporation-based methodologies. Here we describe a rapid and reproducible method for the electroporation of Halomonas sp. O-1 with plasmid DNA. Electrocompetent cells were generated by growing Halomonas sp. O-1 in a yeast extract-tryptone medium with a final salinity of 3.5%, pH of 7.5, followed by several washes using 300mM sucrose. Results show that plasmids containing chloramphenicol (Cm(R)) and gentamicin (Gm(R)) resistance cassettes are suitable antibiotic selection markers for transformation and yields of 10(4) transformants per μg of DNA were obtained. This method is simple to perform and the materials used are readily available in most research labs. Additionally, this plasmid-based transformation procedure has the potential to be adapted for a number of applications including the creation of recombinant stains and the generation of deletion mutants of Halomonas spp. PMID:27542998
Xu, Kedong; Huang, Xiaohui; Wu, Manman; Wang, Yan; Chang, Yunxia; Liu, Kun; Zhang, Ju; Zhang, Yi; Zhang, Fuli; Yi, Liming; Li, Tingting; Wang, Ruiyue; Tan, Guangxuan; Li, Chengwei
2014-01-01
Transient transformation is simpler, more efficient and economical in analyzing protein subcellular localization than stable transformation. Fluorescent fusion proteins were often used in transient transformation to follow the in vivo behavior of proteins. Onion epidermis, which has large, living and transparent cells in a monolayer, is suitable to visualize fluorescent fusion proteins. The often used transient transformation methods included particle bombardment, protoplast transfection and Agrobacterium-mediated transformation. Particle bombardment in onion epidermis was successfully established, however, it was expensive, biolistic equipment dependent and with low transformation efficiency. We developed a highly efficient in planta transient transformation method in onion epidermis by using a special agroinfiltration method, which could be fulfilled within 5 days from the pretreatment of onion bulb to the best time-point for analyzing gene expression. The transformation conditions were optimized to achieve 43.87% transformation efficiency in living onion epidermis. The developed method has advantages in cost, time-consuming, equipment dependency and transformation efficiency in contrast with those methods of particle bombardment in onion epidermal cells, protoplast transfection and Agrobacterium-mediated transient transformation in leaf epidermal cells of other plants. It will facilitate the analysis of protein subcellular localization on a large scale. PMID:24416168
Transformation-cost time-series method for analyzing irregularly sampled data
NASA Astrophysics Data System (ADS)
Ozken, Ibrahim; Eroglu, Deniz; Stemler, Thomas; Marwan, Norbert; Bagci, G. Baris; Kurths, Jürgen
2015-06-01
Irregular sampling of data sets is one of the challenges often encountered in time-series analysis, since traditional methods cannot be applied and the frequently used interpolation approach can corrupt the data and bias the subsequence analysis. Here we present the TrAnsformation-Cost Time-Series (TACTS) method, which allows us to analyze irregularly sampled data sets without degenerating the quality of the data set. Instead of using interpolation we consider time-series segments and determine how close they are to each other by determining the cost needed to transform one segment into the following one. Using a limited set of operations—with associated costs—to transform the time series segments, we determine a new time series, that is our transformation-cost time series. This cost time series is regularly sampled and can be analyzed using standard methods. While our main interest is the analysis of paleoclimate data, we develop our method using numerical examples like the logistic map and the Rössler oscillator. The numerical data allows us to test the stability of our method against noise and for different irregular samplings. In addition we provide guidance on how to choose the associated costs based on the time series at hand. The usefulness of the TACTS method is demonstrated using speleothem data from the Secret Cave in Borneo that is a good proxy for paleoclimatic variability in the monsoon activity around the maritime continent.
A complex guided spectral transform Lanczos method for studying quantum resonance states
Yu, Hua-Gen
2014-12-28
A complex guided spectral transform Lanczos (cGSTL) algorithm is proposed to compute both bound and resonance states including energies, widths and wavefunctions. The algorithm comprises of two layers of complex-symmetric Lanczos iterations. A short inner layer iteration produces a set of complex formally orthogonal Lanczos (cFOL) polynomials. They are used to span the guided spectral transform function determined by a retarded Green operator. An outer layer iteration is then carried out with the transform function to compute the eigen-pairs of the system. The guided spectral transform function is designed to have the same wavefunctions as the eigenstates of the originalmore » Hamiltonian in the spectral range of interest. Therefore the energies and/or widths of bound or resonance states can be easily computed with their wavefunctions or by using a root-searching method from the guided spectral transform surface. The new cGSTL algorithm is applied to bound and resonance states of HO₂, and compared to previous calculations.« less
A complex guided spectral transform Lanczos method for studying quantum resonance states
Yu, Hua-Gen
2014-12-28
A complex guided spectral transform Lanczos (cGSTL) algorithm is proposed to compute both bound and resonance states including energies, widths and wavefunctions. The algorithm comprises of two layers of complex-symmetric Lanczos iterations. A short inner layer iteration produces a set of complex formally orthogonal Lanczos (cFOL) polynomials. They are used to span the guided spectral transform function determined by a retarded Green operator. An outer layer iteration is then carried out with the transform function to compute the eigen-pairs of the system. The guided spectral transform function is designed to have the same wavefunctions as the eigenstates of the original Hamiltonian in the spectral range of interest. Therefore the energies and/or widths of bound or resonance states can be easily computed with their wavefunctions or by using a root-searching method from the guided spectral transform surface. The new cGSTL algorithm is applied to bound and resonance states of HO₂, and compared to previous calculations.
A complex guided spectral transform Lanczos method for studying quantum resonance states
Yu, Hua-Gen
2014-12-28
A complex guided spectral transform Lanczos (cGSTL) algorithm is proposed to compute both bound and resonance states including energies, widths, and wavefunctions. The algorithm comprises of two layers of complex-symmetric Lanczos iterations. A short inner layer iteration produces a set of complex formally orthogonal Lanczos polynomials. They are used to span the guided spectral transform function determined by a retarded Green operator. An outer layer iteration is then carried out with the transform function to compute the eigen-pairs of the system. The guided spectral transform function is designed to have the same wavefunctions as the eigenstates of the original Hamiltonian in the spectral range of interest. Therefore, the energies and/or widths of bound or resonance states can be easily computed with their wavefunctions or by using a root-searching method from the guided spectral transform surface. The new cGSTL algorithm is applied to bound and resonance states of HO{sub 2}, and compared to previous calculations.
Mano, Hiroaki; Fujii, Tomomi; Sumikawa, Naomi; Hiwatashi, Yuji; Hasebe, Mitsuyasu
2014-01-01
The sensitive plant Mimosa pudica has long attracted the interest of researchers due to its spectacular leaf movements in response to touch or other external stimuli. Although various aspects of this seismonastic movement have been elucidated by histological, physiological, biochemical, and behavioral approaches, the lack of reverse genetic tools has hampered the investigation of molecular mechanisms involved in these processes. To overcome this obstacle, we developed an efficient genetic transformation method for M. pudica mediated by Agrobacterium tumefaciens (Agrobacterium). We found that the cotyledonary node explant is suitable for Agrobacterium-mediated transformation because of its high frequency of shoot formation, which was most efficiently induced on medium containing 0.5 µg/ml of a synthetic cytokinin, 6-benzylaminopurine (BAP). Transformation efficiency of cotyledonary node cells was improved from almost 0 to 30.8 positive signals arising from the intron-sGFP reporter gene by using Agrobacterium carrying a super-binary vector pSB111 and stabilizing the pH of the co-cultivation medium with 2-(N-morpholino)ethanesulfonic acid (MES) buffer. Furthermore, treatment of the explants with the detergent Silwet L-77 prior to co-cultivation led to a two-fold increase in the number of transformed shoot buds. Rooting of the regenerated shoots was efficiently induced by cultivation on irrigated vermiculite. The entire procedure for generating transgenic plants achieved a transformation frequency of 18.8%, which is comparable to frequencies obtained for other recalcitrant legumes, such as soybean (Glycine max) and pea (Pisum sativum). The transgene was stably integrated into the host genome and was inherited across generations, without affecting the seismonastic or nyctinastic movements of the plants. This transformation method thus provides an effective genetic tool for studying genes involved in M. pudica movements. PMID:24533121
Mano, Hiroaki; Fujii, Tomomi; Sumikawa, Naomi; Hiwatashi, Yuji; Hasebe, Mitsuyasu
2014-01-01
The sensitive plant Mimosa pudica has long attracted the interest of researchers due to its spectacular leaf movements in response to touch or other external stimuli. Although various aspects of this seismonastic movement have been elucidated by histological, physiological, biochemical, and behavioral approaches, the lack of reverse genetic tools has hampered the investigation of molecular mechanisms involved in these processes. To overcome this obstacle, we developed an efficient genetic transformation method for M. pudica mediated by Agrobacterium tumefaciens (Agrobacterium). We found that the cotyledonary node explant is suitable for Agrobacterium-mediated transformation because of its high frequency of shoot formation, which was most efficiently induced on medium containing 0.5 µg/ml of a synthetic cytokinin, 6-benzylaminopurine (BAP). Transformation efficiency of cotyledonary node cells was improved from almost 0 to 30.8 positive signals arising from the intron-sGFP reporter gene by using Agrobacterium carrying a super-binary vector pSB111 and stabilizing the pH of the co-cultivation medium with 2-(N-morpholino)ethanesulfonic acid (MES) buffer. Furthermore, treatment of the explants with the detergent Silwet L-77 prior to co-cultivation led to a two-fold increase in the number of transformed shoot buds. Rooting of the regenerated shoots was efficiently induced by cultivation on irrigated vermiculite. The entire procedure for generating transgenic plants achieved a transformation frequency of 18.8%, which is comparable to frequencies obtained for other recalcitrant legumes, such as soybean (Glycine max) and pea (Pisum sativum). The transgene was stably integrated into the host genome and was inherited across generations, without affecting the seismonastic or nyctinastic movements of the plants. This transformation method thus provides an effective genetic tool for studying genes involved in M. pudica movements. PMID:24533121
New approach application of data transformation in mean centering of ratio spectra method
NASA Astrophysics Data System (ADS)
Issa, Mahmoud M.; Nejem, R.'afat M.; Van Staden, Raluca Ioana Stefan; Aboul-Enein, Hassan Y.
2015-05-01
Most of mean centering (MCR) methods are designed to be used with data sets whose values have a normal or nearly normal distribution. The errors associated with the values are also assumed to be independent and random. If the data are skewed, the results obtained may be doubtful. Most of the time, it was assumed a normal distribution and if a confidence interval includes a negative value, it was cut off at zero. However, it is possible to transform the data so that at least an approximately normal distribution is attained. Taking the logarithm of each data point is one transformation frequently used. As a result, the geometric mean is deliberated a better measure of central tendency than the arithmetic mean. The developed MCR method using the geometric mean has been successfully applied to the analysis of a ternary mixture of aspirin (ASP), atorvastatin (ATOR) and clopidogrel (CLOP) as a model. The results obtained were statistically compared with reported HPLC method.
An automatic recognition method of pointer instrument based on improved Hough transform
NASA Astrophysics Data System (ADS)
Xu, Li; Fang, Tian; Gao, Xiaoyu
2015-10-01
For the automatic recognition of pointer instrument, the method for the automatic recognition of pointer instrument based on improved Hough Transform was proposed in this paper. The automatic recognition of pointer instrument is applied to all kinds of lighting conditions, but the accuracy of it binaryzation will be influenced when the light is too strong or too dark. Therefore, the improved Ostu method was suggested to realize recognition for adaptive thresholding of pointer instrument under all kinds of lighting conditions. On the basis of dial image characteristics, Otsu method is used to get the value of maximum between-cluster variance and initial threshold than analyze its maximum between-cluster variance value to determine the light and shade of the image. When the images are too bright or too dark, the smaller pixels should be given up and then calculate the initial threshold by Otsu method again and again until the best binaryzation image was obtained. Hence, transform the pointer straight line of the binaryzation image to Hough parameter space through improved Hough Transform to determine the position of the pointer straight line by searching the maximum value of arrays of the same angle. Finally, according to angle method, the pointer reading was obtained by the linear relationship for the initial scale and angle of the pointer instrument. Results show that the improved Otsu method make pointer instrument possible to obtained the accuracy binaryzation image even though the light is too bright or too dark , which improves the adaptability of pointer instrument to automatic recognize the light under different conditions. For the pressure gauges with range of 60MPa, the relative error identification reached to 0.005 when use the improved Hough Transform Algorithm.
Method to eliminate flux linkage DC component in load transformer for static transfer switch.
He, Yu; Mao, Chengxiong; Lu, Jiming; Wang, Dan; Tian, Bing
2014-01-01
Many industrial and commercial sensitive loads are subject to the voltage sags and interruptions. The static transfer switch (STS) based on the thyristors is applied to improve the power quality and reliability. However, the transfer will result in severe inrush current in the load transformer, because of the DC component in the magnetic flux generated in the transfer process. The inrush current which is always 2 ~ 30 p.u. can cause the disoperation of relay protective devices and bring potential damage to the transformer. The way to eliminate the DC component is to transfer the related phases when the residual flux linkage of the load transformer and the prospective flux linkage of the alternate source are equal. This paper analyzes how the flux linkage of each winding in the load transformer changes in the transfer process. Based on the residual flux linkage when the preferred source is completely disconnected, the method to calculate the proper time point to close each phase of the alternate source is developed. Simulation and laboratory experiments results are presented to show the effectiveness of the transfer method. PMID:25133255
Method to Eliminate Flux Linkage DC Component in Load Transformer for Static Transfer Switch
2014-01-01
Many industrial and commercial sensitive loads are subject to the voltage sags and interruptions. The static transfer switch (STS) based on the thyristors is applied to improve the power quality and reliability. However, the transfer will result in severe inrush current in the load transformer, because of the DC component in the magnetic flux generated in the transfer process. The inrush current which is always 2~30 p.u. can cause the disoperation of relay protective devices and bring potential damage to the transformer. The way to eliminate the DC component is to transfer the related phases when the residual flux linkage of the load transformer and the prospective flux linkage of the alternate source are equal. This paper analyzes how the flux linkage of each winding in the load transformer changes in the transfer process. Based on the residual flux linkage when the preferred source is completely disconnected, the method to calculate the proper time point to close each phase of the alternate source is developed. Simulation and laboratory experiments results are presented to show the effectiveness of the transfer method. PMID:25133255
A new stationary gridline artifact suppression method based on the 2D discrete wavelet transform
Tang, Hui; Tong, Dan; Dong Bao, Xu; Dillenseger, Jean-Louis
2015-04-15
Purpose: In digital x-ray radiography, an antiscatter grid is inserted between the patient and the image receptor to reduce scattered radiation. If the antiscatter grid is used in a stationary way, gridline artifacts will appear in the final image. In most of the gridline removal image processing methods, the useful information with spatial frequencies close to that of the gridline is usually lost or degraded. In this study, a new stationary gridline suppression method is designed to preserve more of the useful information. Methods: The method is as follows. The input image is first recursively decomposed into several smaller subimages using a multiscale 2D discrete wavelet transform. The decomposition process stops when the gridline signal is found to be greater than a threshold in one or several of these subimages using a gridline detection module. An automatic Gaussian band-stop filter is then applied to the detected subimages to remove the gridline signal. Finally, the restored image is achieved using the corresponding 2D inverse discrete wavelet transform. Results: The processed images show that the proposed method can remove the gridline signal efficiently while maintaining the image details. The spectra of a 1D Fourier transform of the processed images demonstrate that, compared with some existing gridline removal methods, the proposed method has better information preservation after the removal of the gridline artifacts. Additionally, the performance speed is relatively high. Conclusions: The experimental results demonstrate the efficiency of the proposed method. Compared with some existing gridline removal methods, the proposed method can preserve more information within an acceptable execution time.
High-capacity method for hiding data in the discrete cosine transform domain
NASA Astrophysics Data System (ADS)
Qazanfari, Kazem; Safabakhsh, Reza
2013-10-01
Steganography is the art and science of hiding data in different media such as texts, audios, images, and videos. Data hiding techniques are generally divided into two groups: spatial and frequency domain techniques. Spatial domain methods generally have low security and, as a result, are less attractive to researchers. Discrete cosine transform (DCT) is the most common transform domain used in steganography and JPEG compression. Since a large number of the DCT coefficients of JPEG images are zero, the capacity of DCT domain-based steganography methods is not very high. We present a high-capacity method for hiding messages in the DCT domain. We describe the method in two classes where the receiver has and where the receiver does not have the cover image. In each class, we consider three cases for each coefficient. By considering n coefficients, there are 3n different situations. The method embeds ⌊log2 3n⌋ bits in these n coefficients. We show that the maximum reachable capacity by our method is 58% higher than the other general steganography methods. Experimental results show that the histogram-based steganalysis methods cannot detect the stego images produced by the proposed method while the capacity is increased significantly.
Shock-induced phase transformations in gallium single crystals by atomistic methods
NASA Astrophysics Data System (ADS)
Kadau, Kai; Cherne, Frank J.; Ravelo, Ramon; Germann, Timothy C.
2013-10-01
Utilizing a modified embedded atom method potential, we performed large-scale classical molecular dynamics simulations (with up to 50 million atoms) to investigate the response of Ga single crystals to shock compression along the three major orientations of the orthorhombic A11 ground state, i.e., [001], [010], and [100]. For weak shocks with particle velocity up<300 m/s, these defect-free single crystals respond elastically, but for stronger shocks, they undergo a structural phase transformation and then (for even stronger shocks) melt. For intermediate shock strengths (300m/s
Face transformation with harmonic models by the finite-volume method with delaunay triangulation.
Li, Zi-Cai; Chiang, John Y; Suen, Ching Y
2010-12-01
To carry out face transformation, this paper presents new numerical algorithms, which consist of two parts, namely, the harmonic models for changes of face characteristics and the splitting techniques for grayness transition. The main method in this paper is a combination of the finite-volume method (FVM) with Delaunay triangulation to solve the Laplace equations in the harmonic transformation of face images. The advantages of the FVM with Delaunay triangulation are given as follows: 1) easy to formulate the linear algebraic equations; 2) good in retaining the pertinent geometric and physical need; and 3) less central processing unit time needed. Numerical and graphical experiments have been conducted for the face transformation from a female (woman) to a male (man), and vice versa. The computed sequential errors are O(N⁻³/²), where N² is the division number of a pixel into subpixels. These computed errors coincide with the analysis on the splitting-shooting method (SSM) with piecewise constant interpolation in the previous paper of Li and Bai. In computation, the average absolute errors of restored pixel grayness can be smaller than 2 out of 256 grayness levels. The FVM is as simple as the finite-difference method (FDM) and as flexible as the finite-element method (FEM). Hence, the FVM is particularly useful when dealing with large face images with a huge number of pixels in shape distortion. The numerical transformation of face images in this paper can be used not only in pattern recognition but also in resampling, image morphing, and computer animation. PMID:20363682
Kamalian, Morteza; Prilepsky, Jaroslaw E; Le, Son Thai; Turitsyn, Sergei K
2016-08-01
In this work, we introduce the periodic nonlinear Fourier transform (PNFT) method as an alternative and efficacious tool for compensation of the nonlinear transmission effects in optical fiber links. In the Part I, we introduce the algorithmic platform of the technique, describing in details the direct and inverse PNFT operations, also known as the inverse scattering transform for periodic (in time variable) nonlinear Schrödinger equation (NLSE). We pay a special attention to explaining the potential advantages of the PNFT-based processing over the previously studied nonlinear Fourier transform (NFT) based methods. Further, we elucidate the issue of the numerical PNFT computation: we compare the performance of four known numerical methods applicable for the calculation of nonlinear spectral data (the direct PNFT), in particular, taking the main spectrum (utilized further in Part II for the modulation and transmission) associated with some simple example waveforms as the quality indicator for each method. We show that the Ablowitz-Ladik discretization approach for the direct PNFT provides the best performance in terms of the accuracy and computational time consumption. PMID:27505799
Application of Classical and Lie Transform Methods to Zonal Perturbation in the Artificial Satellite
NASA Astrophysics Data System (ADS)
San-Juan, J. F.; San-Martin, M.; Perez, I.; Lopez-Ochoa, L. M.
2013-08-01
A scalable second-order analytical orbit propagator program is being carried out. This analytical orbit propagator combines modern perturbation methods, based on the canonical frame of the Lie transform, and classical perturbation methods in function of orbit types or the requirements needed for a space mission, such as catalog maintenance operations, long period evolution, and so on. As a first step on the validation of part of our orbit propagator, in this work we only consider the perturbation produced by zonal harmonic coefficients in the Earth's gravity potential, so that it is possible to analyze the behaviour of the perturbation methods involved in the corresponding analytical theories.
NASA Astrophysics Data System (ADS)
Tavares, Paulo J.; Vaz, Mário A. P.
2013-03-01
Gradient range and spatial resolution in Fourier Transform Profilometry depend on the size of the filter window in reciprocal space. The proposed methods to date for the elimination of the fundamental frequency and enlargement of the filter window are either too computationally complex or depend on the possibility of using two frames, thus disabling the method's ability to cope with dynamic situations and subjecting the results to possible intensity changes between the two frame acquisitions. This article describes a simple method for using a single crossed fringe pattern to accomplish that objective, greatly improving the previously reported technique, whilst retaining its main advantages.
NASA Astrophysics Data System (ADS)
Martan, J.; Semmar, N.; Cibulka, O.
2011-06-01
Infrared (IR) radiometry and time resolved reflectivity (TRR) methods can be used for investigation of laser pulse effects on materials in nanosecond time scale. The methods in combination are capable to quantify object temperature and detect phase transformations in the solid state, melting and plasma formation from vapour. Measurements with different laser pulse energy densities provide threshold of the transformation. The melt duration can be also determined. The experimental system is described. It contains KrF excimer laser with homogenizer and variable attenuator, fast IR detector for radiometry, continuous probing laser with Si photodiode for reflectivity measurement and UV detector for pump laser pulse reflection measurement. The system was applied to investigation of responses to laser light of silicon and different pure metals and alloys. The range of energy densities used was 1-5500 mJ.cm-2 and measurements were done with temporal resolution of 6 ns for radiometry and 1 ns for reflectivity.
Ghiglia, D.C.; Romero, L.A. )
1994-01-01
Two-dimensional (2D) phase unwrapping continues to find applications in a wide variety of scientific and engineering areas including optical and microwave interferometry, adaptive optics, compensated imaging, and synthetic-aperture-radar phase correction, and image processing. We have developed a robust method (not based on any path-following scheme) for unwrapping 2D phase principal values (in a least-squares sense) by using fast cosine transforms. If the 2D phase values are associated with a 2D weighting, the fast transforms can still be used in iterative methods for solving the weighted unwrapping problem. Weighted unwrapping can be used to isolate inconsistent regions (i.e., phase shear) in an elegant fashion.
A method for the analysis of respiratory sinus arrhythmia using continuous wavelet transforms.
Cnockaert, Laurence; Migeotte, Pierre-François; Daubigny, Lise; Prisk, G Kim; Grenez, Francis; Sá, Rui Carlos
2008-05-01
A continuous wavelet transform-based method is presented to study the nonstationary strength and phase delay of the respiratory sinus arrhythmia (RSA). The RSA is the cyclic variation of instantaneous heart rate at the breathing frequency. In studies of cardio-respiratory interaction during sleep, paced breathing or postural changes, low respiratory frequencies, and fast changes can occur. Comparison on synthetic data presented here shows that the proposed method outperforms traditional short-time Fourier-transform analysis in these conditions. On the one hand, wavelet analysis presents a sufficient frequency-resolution to handle low respiratory frequencies, for which time frames should be long in Fourier-based analysis. On the other hand, it is able to track fast variations of the signals in both amplitude and phase for which time frames should be short in Fourier-based analysis. PMID:18440911
Jing, Zhang; Sheng, Kang Bao
2016-01-01
To assist physicians to quickly find the required 3D model from the mass medical model, we propose a novel retrieval method, called DRFVT, which combines the characteristics of dimensionality reduction (DR) and feature vector transformation (FVT) method. The DR method reduces the dimensionality of feature vector; only the top M low frequency Discrete Fourier Transform coefficients are retained. The FVT method does the transformation of the original feature vector and generates a new feature vector to solve the problem of noise sensitivity. The experiment results demonstrate that the DRFVT method achieves more effective and efficient retrieval results than other proposed methods. PMID:27293478
Zhang, Yu-xin; Cheng, Zhi-feng; Xu, Zheng-ping; Bai, Jing
2015-01-01
In order to solve the problems such as complex operation, consumption for the carrier gas and long test period in traditional power transformer fault diagnosis approach based on dissolved gas analysis (DGA), this paper proposes a new method which is detecting 5 types of characteristic gas content in transformer oil such as CH4, C2H2, C2H4, C2H6 and H2 based on photoacoustic Spectroscopy and C2H2/C2H4, CH4/H2, C2H4/C2H6 three-ratios data are calculated. The support vector machine model was constructed using cross validation method under five support vector machine functions and four kernel functions, heuristic algorithms were used in parameter optimization for penalty factor c and g, which to establish the best SVM model for the highest fault diagnosis accuracy and the fast computing speed. Particles swarm optimization and genetic algorithm two types of heuristic algorithms were comparative studied in this paper for accuracy and speed in optimization. The simulation result shows that SVM model composed of C-SVC, RBF kernel functions and genetic algorithm obtain 97. 5% accuracy in test sample set and 98. 333 3% accuracy in train sample set, and genetic algorithm was about two times faster than particles swarm optimization in computing speed. The methods described in this paper has many advantages such as simple operation, non-contact measurement, no consumption for the carrier gas, long test period, high stability and sensitivity, the result shows that the methods described in this paper can instead of the traditional transformer fault diagnosis by gas chromatography and meets the actual project needs in transformer fault diagnosis. PMID:25993810
Reduced-rank approximations to the far-field transform in the gridded fast multipole method
NASA Astrophysics Data System (ADS)
Hesford, Andrew J.; Waag, Robert C.
2011-05-01
The fast multipole method (FMM) has been shown to have a reduced computational dependence on the size of finest-level groups of elements when the elements are positioned on a regular grid and FFT convolution is used to represent neighboring interactions. However, transformations between plane-wave expansions used for FMM interactions and pressure distributions used for neighboring interactions remain significant contributors to the cost of FMM computations when finest-level groups are large. The transformation operators, which are forward and inverse Fourier transforms with the wave space confined to the unit sphere, are smooth and well approximated using reduced-rank decompositions that further reduce the computational dependence of the FMM on finest-level group size. The adaptive cross approximation (ACA) is selected to represent the forward and adjoint far-field transformation operators required by the FMM. However, the actual error of the ACA is found to be greater than that predicted using traditional estimates, and the ACA generally performs worse than the approximation resulting from a truncated singular-value decomposition (SVD). To overcome these issues while avoiding the cost of a full-scale SVD, the ACA is employed with more stringent accuracy demands and recompressed using a reduced, truncated SVD. The results show a greatly reduced approximation error that performs comparably to the full-scale truncated SVD without degrading the asymptotic computational efficiency associated with ACA matrix assembly.
NASA Astrophysics Data System (ADS)
Moonon, Altan-Ulzii; Hu, Jianwen; Li, Shutao
2015-12-01
The remote sensing image fusion is an important preprocessing technique in remote sensing image processing. In this paper, a remote sensing image fusion method based on the nonsubsampled shearlet transform (NSST) with sparse representation (SR) is proposed. Firstly, the low resolution multispectral (MS) image is upsampled and color space is transformed from Red-Green-Blue (RGB) to Intensity-Hue-Saturation (IHS). Then, the high resolution panchromatic (PAN) image and intensity component of MS image are decomposed by NSST to high and low frequency coefficients. The low frequency coefficients of PAN and the intensity component are fused by the SR with the learned dictionary. The high frequency coefficients of intensity component and PAN image are fused by local energy based fusion rule. Finally, the fused result is obtained by performing inverse NSST and inverse IHS transform. The experimental results on IKONOS and QuickBird satellites demonstrate that the proposed method provides better spectral quality and superior spatial information in the fused image than other remote sensing image fusion methods both in visual effect and object evaluation.
Economou, Chloe; Wannathong, Thanyanan; Szaub, Joanna; Purton, Saul
2014-01-01
The availability of routine techniques for the genetic manipulation of the chloroplast genome of Chlamydomonas reinhardtii has allowed a plethora of reverse-genetic studies of chloroplast biology using this alga as a model organism. These studies range from fundamental investigations of chloroplast gene function and regulation to sophisticated metabolic engineering programs and to the development of the algal chloroplast as a platform for producing high-value recombinant proteins. The established method for delivering transforming DNA into the Chlamydomonas chloroplast involves microparticle bombardment, with the selection of transformant lines most commonly involving the use of antibiotic resistance markers. In this chapter we describe a simpler and cheaper delivery method in which cell/DNA suspensions are agitated with glass beads: a method that is more commonly used for nuclear transformation of Chlamydomonas. Furthermore, we highlight the use of an expression vector (pASapI) that employs an endogenous gene as a selectable marker, thereby avoiding the contentious issue of antibiotic resistance determinants in transgenic lines. PMID:24599870
Fujiki, Yasuhisa; Yokota, Shigefumi; Okada, Yasumasa; Oku, Yoshitaka; Tamura, Yoshiyasu; Ishiguro, Makio; Miwakeichi, Fumikazu
2013-01-01
Functional fluorescence imaging has been widely applied to analyze spatio-temporal patterns of cellular dynamics in the brain and spinal cord. However, it is difficult to integrate spatial information obtained from imaging data in specific regions of interest across multiple samples, due to large variability in the size, shape and internal structure of samples. To solve this problem, we attempted to standardize transversely sectioned spinal cord images focusing on the laminar structure in the gray matter. We employed three standardization methods, the affine transformation (AT), the angle-dependent transformation (ADT) and the combination of these two methods (AT+ADT). The ADT is a novel non-linear transformation method developed in this study to adjust an individual image onto the template image in the polar coordinate system. We next compared the accuracy of these three standardization methods. We evaluated two indices, i.e., the spatial distribution of pixels that are not categorized to any layer and the error ratio by the leave-one-out cross validation method. In this study, we used neuron-specific marker (NeuN)-stained histological images of transversely sectioned cervical spinal cord slices (21 images obtained from 4 rats) to create the standard atlas and also to serve for benchmark tests. We found that the AT+ADT outperformed other two methods, though the accuracy of each method varied depending on the layer. This novel image standardization technique would be applicable to optical recording such as voltage-sensitive dye imaging, and will enable statistical evaluations of neural activation across multiple samples. PMID:24223702
Scammon, Debra L; Tomoaia-Cotisel, Andrada; Day, Rachel L; Day, Julie; Kim, Jaewhan; Waitzman, Norman J; Farrell, Timothy W; Magill, Michael K
2013-01-01
Objective. To demonstrate the value of mixed methods in the study of practice transformation and illustrate procedures for connecting methods and for merging findings to enhance the meaning derived. Data Source/Study Setting. An integrated network of university-owned, primary care practices at the University of Utah (Community Clinics or CCs). CC has adopted Care by Design, its version of the Patient Centered Medical Home. Study Design. Convergent case study mixed methods design. Data Collection/Extraction Methods. Analysis of archival documents, internal operational reports, in-clinic observations, chart audits, surveys, semistructured interviews, focus groups, Centers for Medicare and Medicaid Services database, and the Utah All Payer Claims Database. Principal Findings. Each data source enriched our understanding of the change process and understanding of reasons that certain changes were more difficult than others both in general and for particular clinics. Mixed methods enabled generation and testing of hypotheses about change and led to a comprehensive understanding of practice change. Conclusions. Mixed methods are useful in studying practice transformation. Challenges exist but can be overcome with careful planning and persistence. PMID:24279836
NASA Astrophysics Data System (ADS)
Nanato, N.; Kobayashi, Y.
AC high temperature superconducting (HTS) coils have been developed for transformers, motors and so on. Quench detection and protection system are essential for safety operations of the AC HTS facilities. The balance voltage method is universally used for the quench detection and protection, however especially for AC operations, the method has risks in terms of high voltage sparks. Because the method needs a voltage tap soldered to a midpoint of the coil winding and the AC HTS facilities generally operate at high voltages and therefore high voltage sparks may occur at the midpoint with no insulation. We have proposed the active power method for the quench detection and protection. The method requires no voltage tap on the midpoint of the coil winding and therefore it has in-built effectiveness for the AC HTS facilities. In this paper, we show that the method can detect the quench in an HTS transformer and moreover our proposed quench protection circuits which consist of thyristors are simple and useful for the AC HTS facilities.
NASA Astrophysics Data System (ADS)
Zhou, H.; Srinivasan, S.; Li, L.; Bryant, S. L.
2013-12-01
Uncertainty in prediction of flow performance stems from the uncertainty in model parameters such as conductivity, porosity etc., to a large extent, while the characterization of the model parameters is demanding due to the inherent heterogeneity of geologic structures. Inverse modeling approaches attempt to identify the unknown model structures and corresponding parameters by integrating observation data. Several inverse methods have been proposed in the literature ranging from trial-and-error methods to advanced ensemble Kalman filter assimilation, including those that use multiple point statistics to characterize complex geologic structures. However, these methods are hindered by the huge amount of data accumulated with time, for instance, the pressure data are recorded at very fine time intervals from the very early stage of bore hole drilling to mature production period. Assimilation of such large amount of data can be a computational burden to the inverse methods. The object of this work is to propose a computationally efficient approach to analyze the long observation records in order to recognize the subsurface structures, especially flow connectivity which plays a critical role in transport prediction. Wavelet transform is found to be a powerful technique that transforms data into different components and analyzes each component at corresponding scale. By analyzing the components transformed we relate the characteristics of the heterogeneity to signature in the production/injection records. Combining components at different scales we are able to recognize connectivity between wells, and thereby identify complex structure in aquifers. The method is demonstrated in a synthetic example where CO2 is injected into a deep saline aquifer for sequestration. The method is computationally efficient since it involves no iterative forward simulation or sensitivity matrix computation. Once the important episodes have been identified in the dynamic data, inverse
Finite volume method for the Black-Scholes equation transformed on finite interval
NASA Astrophysics Data System (ADS)
Valkov, R.
2012-11-01
In this paper, we present a fitted FVM for the degenerate at the two ends parabolic equation, derived from the Black-Scholes equation after a transformation to a finite interval. For the case of European options we describe a fully discretization of the vertical method of lines, where the spatial discretization is formulated as a Petrov-Galerkin FEM. We show that the method is O(h) convergent and monotone. Numerical experiments are presented to verify the theoretical results. Experiments on a power-graded mesh demonstrate higher accuracy.
Mehrabi, Saeed; Mohammadi, Iman; Kunjan, Kislaya; Kharrazi, Hadi
2013-01-01
Large datasets may contain redundant data. Variable selection methods that select most relevant variables in the data set, fail to consider the interaction between the variables. Data transformation methods are used to transfer the original data to a new dimension and capture the most significant information within the data set. The data set used in this study was based on 45 clinical variables collected from 697 patients diagnosed as either having myocardial infarction (MI) or not. Principal component analysis (PCA) and independent component analysis (ICA) were applied prior to classification of patients to MI or Non-MI groups using support vector machines (SVM). PMID:23920977
Three-dimensional profiling using the Fourier transform method with a hexagonal grating projection
Iwata, Koichi; Kusunoki, Fuminori; Moriwaki, Kousuke; Fukuda, Hiroki; Tomii, Takaharu
2008-04-20
We present three-dimensional profilometry based on triangulation in which a hexagonal pattern is projected on the object. To obtain an accurate result with a one-shot photographic image, the Fourier transform method and method of excess fraction are adopted. The three grating components of the hexagonal pattern are used. For compactness a new pattern projection scheme is introduced. The experimental results show that the constructed optical system works well for measuring the profile of a mannequin with a height resolution of {approx} {+-} 1 mm.
Laplace transform homotopy perturbation method for the approximation of variational problems.
Filobello-Nino, U; Vazquez-Leal, H; Rashidi, M M; Sedighi, H M; Perez-Sesma, A; Sandoval-Hernandez, M; Sarmiento-Reyes, A; Contreras-Hernandez, A D; Pereyra-Diaz, D; Hoyos-Reyes, C; Jimenez-Fernandez, V M; Huerta-Chua, J; Castro-Gonzalez, F; Laguna-Camacho, J R
2016-01-01
This article proposes the application of Laplace Transform-Homotopy Perturbation Method and some of its modifications in order to find analytical approximate solutions for the linear and nonlinear differential equations which arise from some variational problems. As case study we will solve four ordinary differential equations, and we will show that the proposed solutions have good accuracy, even we will obtain an exact solution. In the sequel, we will see that the square residual error for the approximate solutions, belongs to the interval [0.001918936920, 0.06334882582], which confirms the accuracy of the proposed methods, taking into account the complexity and difficulty of variational problems. PMID:27006884
Niece, Krista L.
2015-01-01
Colistin use has increased in response to the advent of infections caused by multidrug-resistant organisms. It is administered parenterally as an inactive prodrug, colistin methanesulfonate (CMS). Various formulations of CMS and labeling conventions can lead to confusion about colistin dosing, and questions remain about the pharmacokinetics of CMS. Since CMS does not have strong UV absorbance, current methods employ a laborious process of chemical conversion to colistin followed by precolumn derivatization to detect formed colistin by high-performance liquid chromatography. Here, we report a method for direct quantification of colistin methanesulfonate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR). PMID:26124160
NASA Astrophysics Data System (ADS)
Sharma, Dinkar; Singh, Prince; Chauhan, Shubha
2016-01-01
In this paper, a combined form of the Laplace transform method with the homotopy perturbation method (HPTM) is applied to solve nonlinear systems of partial differential equations viz. the system of third order KdV Equations and the systems of coupled Burgers' equations in one- and two- dimensions. The nonlinear terms can be easily handled by the use of He's polynomials. The results shows that the HPTM is very efficient, simple and avoids the round-off errors. Four test examples are considered to illustrate the present scheme. Further the results are compared with Homotopy perturbation method (HPM) which shows that this method is a suitable method for solving systems of partial differential equations.
Jones, Cynthia G; Silverman, Joseph; Al-Sheikhly, Mohamad; Neta, Pedatsur; Poster, Dianne L
2003-12-15
Used electrical transformer oils containing low or high concentrations of polychlorinated biphenyls (PCBs) were treated using electron, gamma, and ultraviolet radiation, and the conditions for complete dechlorination were developed. Dechlorination was determined by analysis of the inorganic chloride formed and the concentrations of remaining PCBs. Transformer oil containing approximately 95 microg g(-1) PCB (approximately 3.5 mmol L(-1) Cl) is completely dechlorinated by irradiation with 600 kGy after the addition of 10% triethylamine (TEA). Transformer oil containing >800,000 microg g(-1) PCB (17.7 mol L(-1) Cl) requires an additional solvent to prevent solidification. When this oil is diluted with 2-propanol (2-PrOH) and TEA (v/v/v, 1/79/20), complete dechlorination is achieved with a dose of 2500 kGy. Ultraviolet photolysis of the same oil/2-PrOH/TEA solutions led to 90% dechlorination after exposure for 120 h in our experimental setup. Such yields were obtained by radiolysis with a dose of 2000 kGy (300 h in our Gammacell). Replacing TEA with KOH in 2-PrOH solutions greatly increases the yield of dechlorination in both the radiolytic and the photolytic experiments, demonstrating that a chain reaction plays a role in both of these treatment methods and suggesting that both methods deserve further consideration for large-scale application. PMID:14717194
de Oliveira, M E; de Oliveira, G N; de Souza, J C; dos Santos, P A M
2016-02-10
In the present paper, the method of simultaneous moiré-like fringe pattern projection for Fourier transform profilometry is described. The photorefractive holographic interferometric process produces controlled moiré-like patterns with two or more different variation directions. Each low spatial frequency fringe pattern is experimentally obtained as a result of the superposition of two high spatial frequency sinusoidal gratings, with slightly different pitches, for each fringe variation direction. These dynamic moiré-like patterns are induced due to an optical holographic beating of the sinusoidal induced gratings in the volume of the photorefractive Bi₁₂TiO₂₀ (BTO) crystal sample used as dynamic holographic medium. Two or more moiré-like fringe patterns, with at least two different variation directions, simultaneously (or not), are projected onto the object surface. Thus, this is the 2D fringe projection stage of our proposed Fourier transform procedure to determine the profile of a simple object. PMID:26906374
Transformation of Sinorhizobium meliloti MTCC 100 and Mesorhizobium ciceri TAL 620 by CaCl2 method.
Patel, Urmi; Sinha, Sarika
2010-01-01
The CaCl2 method, commonly used for transformation of Escherichia coli, was modified and used to develop a simpler and easier transformation method for Rhizobia sp. Two species of Rhizobia, Sinorhizobium meliloti MTCC 100 and Mesorhizobium ciceri TAL 620, were transformed with the 13.2 kb binary vector pGA482. At an optical density of 0.4, the transformation efficiencies in Sinorhizobium meliloti MTCC 100 and Mesorhizobium ciceri TAL 620 were 104 and 103, respectively. Competent cells of Sinorhizobium meliloti MTCC 100 were prepared at different growth intervals and transformed by the same vector. A maximum transformation efficiency of 104 was achieved at an optical density of 0.5. PMID:20130696
NASA Astrophysics Data System (ADS)
Yang, Zhou; Zhu, Yunpeng; Ren, Hongrui; Zhang, Yimin
2015-03-01
Reliability allocation of computerized numerical controlled(CNC) lathes is very important in industry. Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate components, which is not applicable in some conditions. Aiming at solving the problem of CNC lathes reliability allocating, a comprehensive reliability allocation method based on cubic transformed functions of failure modes and effects analysis(FMEA) is presented. Firstly, conventional reliability allocation methods are introduced. Then the limitations of direct combination of comprehensive allocation method with the exponential transformed FMEA method are investigated. Subsequently, a cubic transformed function is established in order to overcome these limitations. Properties of the new transformed functions are discussed by considering the failure severity and the failure occurrence. Designers can choose appropriate transform amplitudes according to their requirements. Finally, a CNC lathe and a spindle system are used as an example to verify the new allocation method. Seven criteria are considered to compare the results of the new method with traditional methods. The allocation results indicate that the new method is more flexible than traditional methods. By employing the new cubic transformed function, the method covers a wider range of problems in CNC reliability allocation without losing the advantages of traditional methods.
Schurig, David
2007-02-21
I will explain how the transformation design method can yield a material specification that possesses the same electromagnetic behavior as a fairly general set of imagined space-time topologies. This method has been used to design invisibility cloaks, but the method is quite general and can be used to design a wide variety of interesting devices that guide, concentrate or shape electromagnetic fields in ways that would be difficult to manage with other design methodologies. Applications range from stealth to energy conversion and distribution to wireless communications to biomedical imaging. The drawback of the method is the complexity of the material specifications that it produces, which are in general anisotropic and inhomogeneous. Only with recent advances in the field of metamaterials can these specifications be realized. I will discuss how metamaterials accomplish this and what their limitations are, e.g. bandwidth, loss, frequency range etc. I will discuss in detail the recent implementation of an invisibility cloak in the microwave spectrum.
Binary encoding method to encrypt Fourier-transformed information of digital images
NASA Astrophysics Data System (ADS)
Lin, Kuang Tsan
2009-02-01
An encoding method is used to encrypt the Fourier-transformed information of a hidden (covert) digital image in an overt image, while the Fourier-transformed information must be encoded with binary codes. All of the pixels in an overt image are classified into five groups that are called identification, type, tracing, dimension, and information codes. Identification codes are used to judge if the overt image contains codes that belong to the proposed encoding method or not; type codes are used to judge the encoding type; tracing codes are used to judge the encoding trace; dimension codes are used to judge the size of the hidden information; and information codes are used to decode the hidden information. Applying the proposed encoding method is rather easy, and host images corresponding to overt images are not needed for decoding work. The experiment has demonstrated four types of encoding for the proposed encoding method to reconstruct covert images without any distortion or only with a little distortion.
NASA Astrophysics Data System (ADS)
Han, Jiafu; Li, Hongsheng; Ma, Liuqing
2009-09-01
High-quality spatially referenced population information plays an important role in many social-demographic fields. This paper focuses on grid transformation method for population data by combining geographic factors and simulated township boundary adjustment. Given the location, area and census data of each town-level administrative unit and national base map (1:25000) in China, 1km*1km gridded population data can be acquired after interpolation and several adjustments. Besides the adjustment based on geographical factors like topography, transport (roads), rivers and settlements, a new adjustment method based on township boundary simulation and total population of the town is proposed in this paper. The Voronoi polygon of town point is generated and rasterized into 1km*1km grids. Considering the area of each township and boundary line of the corresponding country, the collapse or expansion process of the rasterized Voronoi polygon is conducted pixel by pixel to minimize the differences between total count of grids with same township ID and the announced area of the corresponding township iteratively. After boundary simulation, gridded population data is adjusted based on town-level census data. The study indicated that the proposed method can acquire fine-grained grid population surface. It is demonstrated as an effective method to transform census population data into regular grids.
NASA Astrophysics Data System (ADS)
Han, Jiafu; Li, Hongsheng; Ma, Liuqing
2010-11-01
High-quality spatially referenced population information plays an important role in many social-demographic fields. This paper focuses on grid transformation method for population data by combining geographic factors and simulated township boundary adjustment. Given the location, area and census data of each town-level administrative unit and national base map (1:25000) in China, 1km*1km gridded population data can be acquired after interpolation and several adjustments. Besides the adjustment based on geographical factors like topography, transport (roads), rivers and settlements, a new adjustment method based on township boundary simulation and total population of the town is proposed in this paper. The Voronoi polygon of town point is generated and rasterized into 1km*1km grids. Considering the area of each township and boundary line of the corresponding country, the collapse or expansion process of the rasterized Voronoi polygon is conducted pixel by pixel to minimize the differences between total count of grids with same township ID and the announced area of the corresponding township iteratively. After boundary simulation, gridded population data is adjusted based on town-level census data. The study indicated that the proposed method can acquire fine-grained grid population surface. It is demonstrated as an effective method to transform census population data into regular grids.
NASA Astrophysics Data System (ADS)
Zhang, B.; Sang, Jun; Alam, Mohammad S.
2013-03-01
An image hiding method based on cascaded iterative Fourier transform and public-key encryption algorithm was proposed. Firstly, the original secret image was encrypted into two phase-only masks M1 and M2 via cascaded iterative Fourier transform (CIFT) algorithm. Then, the public-key encryption algorithm RSA was adopted to encrypt M2 into M2' . Finally, a host image was enlarged by extending one pixel into 2×2 pixels and each element in M1 and M2' was multiplied with a superimposition coefficient and added to or subtracted from two different elements in the 2×2 pixels of the enlarged host image. To recover the secret image from the stego-image, the two masks were extracted from the stego-image without the original host image. By applying public-key encryption algorithm, the key distribution was facilitated, and also compared with the image hiding method based on optical interference, the proposed method may reach higher robustness by employing the characteristics of the CIFT algorithm. Computer simulations show that this method has good robustness against image processing.
Golner, Thomas M.; Mehta, Shirish P.
2005-07-26
A method and apparatus for connecting high voltage leads to a super-conducting transformer is provided that includes a first super-conducting coil set, a second super-conducting coil set, and a third super-conducting coil set. The first, second and third super-conducting coil sets are connected via an insulated interconnect system that includes insulated conductors and insulated connectors that are utilized to connect the first, second, and third super-conducting coil sets to the high voltage leads.
A method for the large scale isolation of high transformation efficiency fungal genomic DNA.
Zhang, D; Yang, Y; Castlebury, L A; Cerniglia, C E
1996-12-01
A procedure for isolation of genomic DNA from the zygomycete Cunninghamella elegans and other filamentous fungi and yeasts is reported. This procedure involves disruption of cells by grinding using dry ice, removal of polysaccharides using cetyltrimethylammonium bromide and by phenol extractions, and precipitation of DNA with isopropanol at room temperature. The isolation method produced large scale (approximate 1 mg DNA/5 g wet cells) and highly purified high molecular mass DNA. Sau3AI partially digested DNA showed high transformation efficiency (> 10(6)/100 ng DNA) when ligated to ZAP-express lambda vector. PMID:8961565
Transform methods for precision continuum and control models of flexible space structures
NASA Technical Reports Server (NTRS)
Lupi, Victor D.; Turner, James D.; Chun, Hon M.
1991-01-01
An open loop optimal control algorithm is developed for general flexible structures, based on Laplace transform methods. A distributed parameter model of the structure is first presented, followed by a derivation of the optimal control algorithm. The control inputs are expressed in terms of their Fourier series expansions, so that a numerical solution can be easily obtained. The algorithm deals directly with the transcendental transfer functions from control inputs to outputs of interest, and structural deformation penalties, as well as penalties on control effort, are included in the formulation. The algorithm is applied to several structures of increasing complexity to show its generality.
Assessment of uncertainty on structural dynamic responses with the short transformation method
NASA Astrophysics Data System (ADS)
Donders, S.; Vandepitte, D.; Van de Peer, J.; Desmet, W.
2005-12-01
The predictive capability of finite element models is limited by their deterministic nature: typically, not all model parameters are exactly known, while even small deviations may have significant effects on the predicted response. Parameter uncertainty should therefore be taken into account, e.g. with fuzzy arithmetic. The absence of fuzzy solvers led to interval arithmetic as a numerical alternative. The Transformation Method (TM), presented by M. Hanss, replaces interval arithmetic with a set of deterministic computations: for each interval, all parameter extrema are combined in every possible way. In a Design of Experiments terminology, the TM is a so-called Full Factorial design. The TM is applicable if the output is monotonic in the inputs. Unlike interval arithmetic, it does not overestimate the response uncertainty, as only parameter combinations are evaluated that actually occur. In this paper, the TM has been applied to visualise uncertain frequency response functions (FRFs), obtained with modal superposition. This yields accurate results when validated against Monte Carlo data, but the computation time is rather high. The Short Transformation Method (STM) is proposed as an attractive alternative to the original TM. A full set of deterministic computations, combining all interval extrema, is only performed at the lowest interval. For higher levels, a smaller set is evaluated. This allows reconstructing the fuzzy FRF from a much lower number of deterministic computations, with only a small reduction in the accuracy of FRFs. Both methods are demonstrated on a clamped plate and a car front cradle with uncertain design parameters.
A Fourier Transform Method for Vsin i Estimations under Nonlinear Limb-darkening Laws
NASA Astrophysics Data System (ADS)
Levenhagen, R. S.
2014-12-01
Star rotation offers us a large horizon for the study of many important physical issues pertaining to stellar evolution. Currently, four methods are widely used to infer rotation velocities, namely those related to line width calibrations, on the fitting of synthetic spectra, interferometry, and on Fourier transforms (FTs) of line profiles. Almost all of the estimations of stellar projected rotation velocities using the Fourier method in the literature have been addressed with the use of linear limb-darkening (LD) approximations during the evaluation of rotation profiles and their cosine FTs, which in certain cases, lead to discrepant velocity estimates. In this work, we introduce new mathematical expressions of rotation profiles and their Fourier cosine transforms assuming three nonlinear LD laws—quadratic, square-root, and logarithmic—and study their applications with and without gravity-darkening (GD) and geometrical flattening (GF) effects. Through an analysis of He I models in the visible range accounting for both limb and GD, we find out that, for classical models without rotationally driven effects, all the Vsin i values are too close to each other. On the other hand, taking into account GD and GF, the Vsin i obtained with the linear law result in Vsin i values that are systematically smaller than those obtained with the other laws. As a rule of thumb, we apply these expressions to the FT method to evaluate the projected rotation velocity of the emission B-type star Achernar (α Eri).
A Fourier transform method for Vsin i estimations under nonlinear Limb-Darkening laws
Levenhagen, R. S.
2014-12-10
Star rotation offers us a large horizon for the study of many important physical issues pertaining to stellar evolution. Currently, four methods are widely used to infer rotation velocities, namely those related to line width calibrations, on the fitting of synthetic spectra, interferometry, and on Fourier transforms (FTs) of line profiles. Almost all of the estimations of stellar projected rotation velocities using the Fourier method in the literature have been addressed with the use of linear limb-darkening (LD) approximations during the evaluation of rotation profiles and their cosine FTs, which in certain cases, lead to discrepant velocity estimates. In this work, we introduce new mathematical expressions of rotation profiles and their Fourier cosine transforms assuming three nonlinear LD laws—quadratic, square-root, and logarithmic—and study their applications with and without gravity-darkening (GD) and geometrical flattening (GF) effects. Through an analysis of He I models in the visible range accounting for both limb and GD, we find out that, for classical models without rotationally driven effects, all the Vsin i values are too close to each other. On the other hand, taking into account GD and GF, the Vsin i obtained with the linear law result in Vsin i values that are systematically smaller than those obtained with the other laws. As a rule of thumb, we apply these expressions to the FT method to evaluate the projected rotation velocity of the emission B-type star Achernar (α Eri).
Kuss, M.; Markel, T.; Kramer, W.
2011-01-01
Concentrated purchasing patterns of plug-in vehicles may result in localized distribution transformer overload scenarios. Prolonged periods of transformer overloading causes service life decrements, and in worst-case scenarios, results in tripped thermal relays and residential service outages. This analysis will review distribution transformer load models developed in the IEC 60076 standard, and apply the model to a neighborhood with plug-in hybrids. Residential distribution transformers are sized such that night-time cooling provides thermal recovery from heavy load conditions during the daytime utility peak. It is expected that PHEVs will primarily be charged at night in a residential setting. If not managed properly, some distribution transformers could become overloaded, leading to a reduction in transformer life expectancy, thus increasing costs to utilities and consumers. A Monte-Carlo scheme simulated each day of the year, evaluating 100 load scenarios as it swept through the following variables: number of vehicle per transformer, transformer size, and charging rate. A general method for determining expected transformer aging rate will be developed, based on the energy needs of plug-in vehicles loading a residential transformer.
Astigmatism error modification for absolute shape reconstruction using Fourier transform method
NASA Astrophysics Data System (ADS)
He, Yuhang; Li, Qiang; Gao, Bo; Liu, Ang; Xu, Kaiyuan; Wei, Xiaohong; Chai, Liqun
2014-12-01
A method is proposed to modify astigmatism errors in absolute shape reconstruction of optical plane using Fourier transform method. If a transmission and reflection flat are used in an absolute test, two translation measurements lead to obtain the absolute shapes by making use of the characteristic relationship between the differential and original shapes in spatial frequency domain. However, because the translation device cannot guarantee the test and reference flats rigidly parallel to each other after the translations, a tilt error exists in the obtained differential data, which caused power and astigmatism errors in the reconstructed shapes. In order to modify the astigmatism errors, a rotation measurement is added. Based on the rotation invariability of the form of Zernike polynomial in circular domain, the astigmatism terms are calculated by solving polynomial coefficient equations related to the rotation differential data, and subsequently the astigmatism terms including error are modified. Computer simulation proves the validity of the proposed method.
Wang Fei; Zhao Xuezeng; Li Ning
2010-10-15
We introduce a multiscale characterization method for line edge roughness (LER) based on redundant second generation wavelet transform. This method involves decomposing LER characteristics into independent bands with different spatial frequency components at different scales, and analyzing the reconstructed signals to work out the roughness exponent, the spatial frequency distribution characteristics, as well as the rms value. The effect of noise can be predicted using detailed signals in the minimum space of scale. This method was applied to numerical profiles for validation. Results show that according to the line edge profiles with similar amplitudes, the roughness exponent R can effectively reflect the degree of irregularity of LER and intuitively provide information on LER spatial frequency distribution.
Secondary Path Modeling Method for Active Noise Control of Power Transformer
NASA Astrophysics Data System (ADS)
Zhao, Tong; Liang, Jiabi; Liang, Yuanbin; Wang, Lixin; Pei, Xiugao; Li, Peng
The accuracy of the secondary path modeling is critical to the stability of active noise control system. On condition of knowing the input and output of the secondary path, system identification theory can be used to identify the path. Based on the experiment data, correlation analysis is adopted to eliminate the random noise and nonlinear harmonic in the output data in order to obtain the accurate frequency characteristic of the secondary path. After that, Levy's Method is applied to identify the transfer function of the path. Computer simulation results are given respectively, both showing the proposed off-line modeling method is feasible and applicable. At last, Levy's Method is used to attain an accurate secondary path model in the active control of transformer noise experiment and achieves to make the noise sound level decrease about 10dB.
NASA Astrophysics Data System (ADS)
Silenko, Alexander J.
2016-02-01
General properties of the Foldy-Wouthuysen transformation which is widely used in quantum mechanics and quantum chemistry are considered. Merits and demerits of the original Foldy-Wouthuysen transformation method are analyzed. While this method does not satisfy the Eriksen condition of the Foldy-Wouthuysen transformation, it can be corrected with the use of the Baker-Campbell-Hausdorff formula. We show a possibility of such a correction and propose an appropriate algorithm of calculations. An applicability of the corrected Foldy-Wouthuysen method is restricted by the condition of convergence of a series of relativistic corrections.
A Simple Method for Predicting Transmembrane Proteins Based on Wavelet Transform
Yu, Bin; Zhang, Yan
2013-01-01
The increasing protein sequences from the genome project require theoretical methods to predict transmembrane helical segments (TMHs). So far, several prediction methods have been reported, but there are some deficiencies in prediction accuracy and adaptability in these methods. In this paper, a method based on discrete wavelet transform (DWT) has been developed to predict the number and location of TMHs in membrane proteins. PDB coded as 1KQG is chosen as an example to describe the prediction process by this method. 80 proteins with known 3D structure from Mptopo database are chosen at random as data sets (including 325 TMHs) and 80 sequences are divided into 13 groups according to their function and type. TMHs prediction is carried out for each group of membrane protein sequences and obtain satisfactory result. To verify the feasibility of this method, 80 membrane protein sequences are treated as test sets, 308 TMHs can be predicted and the prediction accuracy is 96.3%. Compared with the main prediction results of seven popular prediction methods, the obtained results indicate that the proposed method in this paper has higher prediction accuracy. PMID:23289014
NASA Astrophysics Data System (ADS)
Hoang, Nguyen Tien; Koike, Katsuaki
2015-10-01
It has been generally accepted that hyperspectral remote sensing is more effective and provides greater accuracy than multispectral remote sensing in many application fields. EO-1 Hyperion, a representative hyperspectral sensor, has much more spectral bands, while Landsat data has much wider image scene and longer continuous space-based record of Earth's land. This study aims to develop a new method, Pseudo-Hyperspectral Image Synthesis Algorithm (PHISA), to transform Landsat imagery into pseudo hyperspectral imagery using the correlation between Landsat and EO-1 Hyperion data. At first Hyperion scene was precisely pre-processed and co-registered to Landsat scene, and both data were corrected for atmospheric effects. Bayesian model averaging method (BMA) was applied to select the best model from a class of several possible models. Subsequently, this best model is utilized to calculate pseudo-hyperspectral data by R programming. Based on the selection results by BMA, we transform Landsat imagery into 155 bands of pseudo-hyperspectral imagery. Most models have multiple R-squared values higher than 90%, which assures high accuracy of the models. There are no significant differences visually between the pseudo- and original data. Most bands have Pearson's coefficients < 0.95, and only a small fraction has the coefficients < 0.93 like outliers in the data sets. In a similar manner, most Root Mean Square Error values are considerably low, smaller than 0.014. These observations strongly support that the proposed PHISA is valid for transforming Landsat data into pseudo-hyperspectral data from the outlook of statistics.
CMF Signal Processing Method Based on Feedback Corrected ANF and Hilbert Transformation
NASA Astrophysics Data System (ADS)
Tu, Yaqing; Yang, Huiyue; Zhang, Haitao; Liu, Xiangyu
2014-02-01
In this paper, we focus on CMF signal processing and aim to resolve the problems of precision sharp-decline occurrence when using adaptive notch filters (ANFs) for tracking the signal frequency for a long time and phase difference calculation depending on frequency by the sliding Goertzel algorithm (SGA) or the recursive DTFT algorithm with negative frequency contribution. A novel method is proposed based on feedback corrected ANF and Hilbert transformation. We design an index to evaluate whether the ANF loses the signal frequency or not, according to the correlation between the output and input signals. If the signal frequency is lost, the ANF parameters will be adjusted duly. At the same time, singular value decomposition (SVD) algorithm is introduced to reduce noise. And then, phase difference between the two signals is detected through trigonometry and Hilbert transformation. With the frequency and phase difference obtained, time interval of the two signals is calculated. Accordingly, the mass flow rate is derived. Simulation and experimental results show that the proposed method always preserves a constant high precision of frequency tracking and a better performance of phase difference measurement compared with the SGA or the recursive DTFT algorithm with negative frequency contribution
NASA Astrophysics Data System (ADS)
Chen, Hai-Wen; McGurr, Mike; Brickhouse, Mark
2015-11-01
We present a newly developed feature transformation (FT) detection method for hyper-spectral imagery (HSI) sensors. In essence, the FT method, by transforming the original features (spectral bands) to a different feature domain, may considerably increase the statistical separation between the target and background probability density functions, and thus may significantly improve the target detection and identification performance, as evidenced by the test results in this paper. We show that by differentiating the original spectral, one can completely separate targets from the background using a single spectral band, leading to perfect detection results. In addition, we have proposed an automated best spectral band selection process with a double-threshold scheme that can rank the available spectral bands from the best to the worst for target detection. Finally, we have also proposed an automated cross-spectrum fusion process to further improve the detection performance in lower spectral range (<1000 nm) by selecting the best spectral band pair with multivariate analysis. Promising detection performance has been achieved using a small background material signature library for concept-proving, and has then been further evaluated and verified using a real background HSI scene collected by a HYDICE sensor.
Kim, Philseok; Epstein, Alexander K; Khan, Mughees; Zarzar, Lauren D; Lipomi, Darren J; Whitesides, George M; Aizenberg, Joanna
2012-02-01
Arrays of high-aspect-ratio (HAR) nano- and microstructures are of great interest for designing surfaces for applications in optics, bio-nano interfaces, microelectromechanical systems, and microfluidics, but the difficulty of systematically and conveniently varying the geometries of these structures significantly limits their design and optimization for a specific function. This paper demonstrates a low-cost, high-throughput benchtop method that enables a HAR array to be reshaped with nanoscale precision by electrodeposition of conductive polymers. The method-named STEPS (structural transformation by electrodeposition on patterned substrates)-makes it possible to create patterns with proportionally increasing size of original features, to convert isolated HAR features into a closed-cell substrate with a continuous HAR wall, and to transform a simple parent two-dimensional HAR array into new three-dimensional patterned structures with tapered, tilted, anisotropic, or overhanging geometries by controlling the deposition conditions. We demonstrate the fabrication of substrates with continuous or discrete gradients of nanostructure features, as well as libraries of various patterns, starting from a single master structure. By providing exemplary applications in plasmonics, bacterial patterning, and formation of mechanically reinforced structures, we show that STEPS enables a wide range of studies of the effect of substrate topography on surface properties leading to optimization of the structures for a specific application. This research identifies solution-based deposition of conductive polymers as a new tool in nanofabrication and allows access to 3D architectures that were previously difficult to fabricate. PMID:21438614
NASA Astrophysics Data System (ADS)
Lin, Zhili; Li, Xiaoyan; Zhao, Kuixia; Chen, Xudong; Chen, Mingyu; Pu, Jixiong
2016-06-01
For an inertial confinement fusion (ICF) system, the light intensity distribution in the hohlraum is key to the initial plasma excitation and later laser-plasma interaction process. Based on the concept of coordinate transformation of spatial points and vector, we present a robust method with a detailed procedure that makes the calculation of the three dimensional (3D) light intensity distribution in hohlraum easily. The method is intuitive but powerful enough to solve the complex cases of random number of laser beams with arbitrary polarization states and incidence angles. Its application is exemplified in the Shenguang III Facility (SG-III) that verifies its effectiveness and it is useful for guiding the design of hohlraum structure parameter.
NASA Astrophysics Data System (ADS)
Cao, Chao; Chen, Ru-jun
2009-10-01
In this paper, we present a new copyright information hide method for digital images in Moiré fringe formats. The copyright information is embedded into the protected image and the detecting image based on Fresnel phase matrix. Firstly, using Fresnel diffraction transform, the random phase matrix of copyright information is generated. Then, according to Moiré fringe principle, the protected image and the detecting image are modulated respectively based on the random phase matrix, and the copyright information is embedded into them. When the protected image and the detecting image are overlapped, the copyright information can reappear. Experiment results show that our method has good concealment performance, and is a new way for copyright protection.
NASA Astrophysics Data System (ADS)
Hernández-Romo, Martín.; Padilla-Vivanco, Alfonso; Kim, Myung K.; Toxqui-Quitl, Carina
2014-09-01
An analysis of an optical-digital system based on the architecture of the Mach-Zehnder interferometer for recording holographic filters is presented. The holographic recording system makes use of one microscope objective in each interferometer arm. Moreover, the Gabor Wavelet Transform is implemented for the holographic reconstruction stage. The samples studied of this research are selected in order to test the retrieval algorithm and to characterize the resolution of the holographic recording system. In this last step, some sections of an USAF1951 resolution chart are used. These samples allow us to study the features of lighting in the recorded system. Additionally, some organic samples are used to proven the capabilities of the method because biological samples have much complex morphological composition than others. With this in mind, we can verify the frequencies recovered with each of the settings set in the retrieval method. Experimental results are presented.
A two-step Hilbert transform method for 2D image reconstruction.
Noo, Frédéric; Clackdoyle, Rolf; Pack, Jed D
2004-09-01
The paper describes a new accurate two-dimensional (2D) image reconstruction method consisting of two steps. In the first step, the backprojected image is formed after taking the derivative of the parallel projection data. In the second step, a Hilbert filtering is applied along certain lines in the differentiated backprojection (DBP) image. Formulae for performing the DBP step in fanbeam geometry are also presented. The advantage of this two-step Hilbert transform approach is that in certain situations, regions of interest (ROIs) can be reconstructed from truncated projection data. Simulation results are presented that illustrate very similar reconstructed image quality using the new method compared to standard filtered backprojection, and that show the capability to correctly handle truncated projections. In particular, a simulation is presented of a wide patient whose projections are truncated laterally yet for which highly accurate ROI reconstruction is obtained. PMID:15470913
Medical image interpolation method based on similarity analysis of discrete wavelet transforms
NASA Astrophysics Data System (ADS)
Peng, Shichun; Liu, Jian
2007-12-01
A new interpolation method based on multi-resolution technique is presented and used for medical image zooming. The aim of this work is to focus on similarity analysis of adjacent sub-bands provided by Discrete Wavelet Transform (DWT) to enhance the accuracy of the interpolation. First, decompose the original image into sub-bands by the DWT; second, consider the similarity between adjacent sub-bands to calculate the high frequency components; third, use the original image as the low frequency component and apply the inverse DWT to obtain the final interpolation result. Experimental results on magnetic resonance (MR) images and positron emission tomography (PET) images illustrate the effectiveness of the proposed method.
Pan, W; Coatrieux, G; Cuppens, N; Cuppens, F; Roux, Ch
2010-01-01
In this article, we propose a new additive lossless watermarking scheme which identifies parts of the image that can be reversibly watermarked and conducts message embedding in the conventional Haar wavelet transform coefficients. Our approach makes use of an approximation of the image signal that is invariant to the watermark addition for classifying the image in order to avoid over/underflows. The method has been tested on different sets of medical images and some usual natural test images as Lena. Experimental result analysis conducted with respect to several aspects including data hiding capacity and image quality preservation, shows that our method is one of the most competitive existing lossless watermarking schemes in terms of high capacity and low distortion. PMID:21096246
Tao, Li; Yu, Jianjun; Yang, Qi; Shao, Yufeng; Zhang, Junwen; Chi, Nan
2013-03-25
In this paper, a transform domain processing (TDP) based channel estimation method for orthogonal frequency-division multiplexing (OFDM) Radio-over-Fiber (RoF) systems is proposed. Theoretically investigation shows that TDP can greatly reduce the number of required training symbols. An 8 x 4.65 Gb/s multi-user OFDM RoF system over 40 km fiber link and 60 GHz wireless link is experimentally demonstrated utilizing TDP scheme. Compared with conventional time domain averaging (TDA) scheme, the overhead can be reduced from several tens of training symbols to merely one symbol and the receiver sensitivity has been improved by 1.8 dB at BER of 3.8 x 10(-3). The calculated BER performance for 8 wireless users clearly validates the feasibility of this TDP-based channel estimation method. PMID:23546130
NASA Astrophysics Data System (ADS)
Gao, Yingjie; Zhang, Jinhai; Yao, Zhenxing
2016-06-01
The symplectic integration method is popular in high-accuracy numerical simulations when discretizing temporal derivatives; however, it still suffers from time-dispersion error when the temporal interval is coarse, especially for long-term simulations and large-scale models. We employ the inverse time dispersion transform (ITDT) to the third-order symplectic integration method to reduce the time-dispersion error. First, we adopt the pseudospectral algorithm for the spatial discretization and the third-order symplectic integration method for the temporal discretization. Then, we apply the ITDT to eliminate time-dispersion error from the synthetic data. As a post-processing method, the ITDT can be easily cascaded in traditional numerical simulations. We implement the ITDT in one typical exiting third-order symplectic scheme and compare its performances with the performances of the conventional second-order scheme and the rapid expansion method. Theoretical analyses and numerical experiments show that the ITDT can significantly reduce the time-dispersion error, especially for long travel times. The implementation of the ITDT requires some additional computations on correcting the time-dispersion error, but it allows us to use the maximum temporal interval under stability conditions; thus, its final computational efficiency would be higher than that of the traditional symplectic integration method for long-term simulations. With the aid of the ITDT, we can obtain much more accurate simulation results but with a lower computational cost.
A new testing method of SNR for cooled CCD imaging camera based on stationary wavelet transform
NASA Astrophysics Data System (ADS)
Liu, Yan; Liu, Qianshun; Yu, Feihong
2013-08-01
Cooled CCD (charge coupled device) imaging camera has found wide application in the field of astronomy, color photometry, spectroscopy, medical imaging, densitometry, chemiluminescence and epifluorescence imaging. A Cooled CCD (CCCD) imaging camera differs from traditional CCD/CMOS imaging camera in that Cooled CCD imaging camera can get high resolution image even in the low illumination environment. SNR (signal noise ratio) is most popular parameter of digital image quality evaluation. Many researchers have proposed various SNR testing methods for traditional CCD imaging camera, however, which is seldom suitable to Cooled CCD imaging camera because of different main noise source. In this paper, a new testing method of SNR is proposed to evaluate the quality of image captured by Cooled CCD. Stationary Wavelet Transform (SWT) is introduced in the testing method for getting more exact image SNR value. The method proposed take full advantage of SWT in the image processing, which makes the experiment results accuracy and reliable. To further refining SNR testing results, the relation between SNR and integration time is also analyzed in this article. The experimental results indicate that the testing method proposed accords with the SNR model of CCCD. In addition, the testing values for one system are about one value, which show that the proposed testing method is robust.
W-transform method for feature-oriented multiresolution image retrieval
Kwong, M.K.; Lin, B.
1995-07-01
Image database management is important in the development of multimedia technology. Since an enormous amount of digital images is likely to be generated within the next few decades in order to integrate computers, television, VCR, cables, telephone and various imaging devices. Effective image indexing and retrieval systems are urgently needed so that images can be easily organized, searched, transmitted, and presented. Here, the authors present a local-feature-oriented image indexing and retrieval method based on Kwong, and Tang`s W-transform. Multiresolution histogram comparison is an effective method for content-based image indexing and retrieval. However, most recent approaches perform multiresolution analysis for whole images but do not exploit the local features present in the images. Since W-transform is featured by its ability to handle images of arbitrary size, with no periodicity assumptions, it provides a natural tool for analyzing local image features and building indexing systems based on such features. In this approach, the histograms of the local features of images are used in the indexing, system. The system not only can retrieve images that are similar or identical to the query images but also can retrieve images that contain features specified in the query images, even if the retrieved images as a whole might be very different from the query images. The local-feature-oriented method also provides a speed advantage over the global multiresolution histogram comparison method. The feature-oriented approach is expected to be applicable in managing large-scale image systems such as video databases and medical image databases.
2013-01-01
Background Lepidium campestre is an undomesticated oilseed species with a great potential to become a new crop for both food and industrial feedstocks production. Genetic modification is needed for further improving the oil quantity and quality of Lepidium. Studies on in vitro shoot regeneration of Lepidium are very limited and there is no transformation protocol available. Results We have investigated the effects of different factors, especially the type, concentration and combination of plant growth regulators (PGRs) on in vitro shoot regeneration of Lepidium. The results showed that the 2,4-D treatment was crucial to shoot regeneration from different explants. The duration of 2,4-D exposure between 2-4 days did not show significant difference in shoot regeneration, while the effect of 2,4-D concentration varied greatly depending on the type of explants and cytokinins used, for example, the low concentration of 2,4-D combined with TDZ significantly increased the regeneration frequency of hypocotyls. Cotyledon and hypocotyl explants responded differently to cytokinin, for example, TDZ was more effective than zeatin in promoting shoot regeneration from hypocotyls, but did not affect the regeneration of cotyledons which was more affected by high concentration of zeatin. The results also showed that NAA was not effective for shoot regeneration. Germination in light increased the regeneration frequency compared to that in dark. After optimization of the different conditions, an efficient regeneration protocol was developed with the regeneration efficiency of 92.7%. Using this protocol, the transformation frequency of 6% in average was achieved. The presence of transgenes in the transgenic lines was confirmed by GUS staining, PCR and Southern blot analyses. Conclusion Through systematic investigation of important factors affecting in vitro shoot regeneration, we have developed an efficient regeneration and transformation protocol for the genetic modification of
NASA Astrophysics Data System (ADS)
Messer, Sheila R.; Agzarian, John; Abbott, Derek
2001-05-01
Phonocardiograms (PCGs) have many advantages over traditional auscultation (listening to the heart) because they may be replayed, may be analyzed for spectral and frequency content, and frequencies inaudible to the human ear may be recorded. However, various sources of noise may pollute a PCG including lung sounds, environmental noise and noise generated from contact between the recording device and the skin. Because PCG signals are known to be nonlinear and it is often not possible to determine their noise content, traditional de-noising methods may not be effectively applied. However, other methods including wavelet de-noising, wavelet packet de-noising and averaging can be employed to de-noise the PCG. This study examines and compares these de-noising methods. This study answers such questions as to which de-noising method gives a better SNR, the magnitude of signal information that is lost as a result of the de-noising process, the appropriate uses of the different methods down to such specifics as to which wavelets and decomposition levels give best results in wavelet and wavelet packet de-noising. In general, the wavelet and wavelet packet de-noising performed roughly equally with optimal de-noising occurring at 3-5 levels of decomposition. Averaging also proved a highly useful de- noising technique; however, in some cases averaging is not appropriate. The Hilbert Transform is used to illustrate the results of the de-noising process and to extract instantaneous features including instantaneous amplitude, frequency, and phase.
Fujita, Yurika; Kasamatsu, Toshio; Ikeda, Naohiro; Nishiyama, Naohiro; Honda, Hiroshi
2016-01-15
Although in vitro chromosomal aberration tests and micronucleus tests have been widely used for genotoxicity evaluation, false-positive results have been reported under strong cytotoxic conditions. To reduce false-positive results, the new Organization for Economic Co-operation and Development (OECD) test guideline (TG) recommends the use of a new cytotoxicity index, relative increase in cell count or relative population doubling (RICC/RPD), instead of the traditionally used index, relative cell count (RCC). Although the use of the RICC/RPD may result in different outcomes and require re-evaluation of tested substances, it is impractical to re-evaluate all existing data. Therefore, we established a method to estimate test results from existing RCC data. First, we developed formulae to estimate RICC/RPD from RCC without cell counts by considering cell doubling time and experiment time. Next, the accuracy of the cytotoxicity index transformation formulae was verified by comparing estimated RICC/RPD and measured RICC/RPD for 3 major chemicals associated with false-positive genotoxicity test results: ethyl acrylate, eugenol and p-nitrophenol. Moreover, 25 compounds with false-positive in vitro chromosomal aberration (CA) test results were re-evaluated to establish a retrospective evaluation method based on derived estimated RICC/RPD values. The estimated RICC/RPD values were in good agreement with the measured RICC/RPD values for every concentration and chemical, and the estimated RICC suggested the possibility that 12 chemicals (48%) with previously judged false-positive results in fact had negative results. Our method enables transformation of RCC data into RICC/RPD values with a high degree of accuracy and will facilitate comprehensive retrospective evaluation of test results. PMID:26778504
High-throughput transformation method for Yarrowia lipolytica mutant library screening.
Leplat, Christophe; Nicaud, Jean-Marc; Rossignol, Tristan
2015-09-01
As a microorganism of major biotechnological importance, the oleaginous yeast Yarrowia lipolytica is subjected to intensive genetic engineering and functional genomic analysis. Future advancements in this area, however, require a system that will generate a large collection of mutants for high-throughput screening. Here, we report a rapid and efficient method for high-throughput transformation of Y. lipolytica in 96-well plates. We developed plasmids and strains for the large-scale screening of overexpression mutant strains, using Gateway® vectors that were adapted for specific locus integration in Y. lipolytica. As an example, a collection of mutants that overexpressed the alkaline extracellular protease (AEP) was obtained in a single transformation experiment. The platform strain that we developed to receive the overexpression cassette was designed to constitutively express a fluorescent protein as a convenient growth reporter for screening in non-translucid media. An example of growth comparison in skim milk-based medium between AEP overexpression and deletion mutants is provided. PMID:26100263
A new method for RGB to CIELAB color space transformation based on Markov chain Monte Carlo
NASA Astrophysics Data System (ADS)
Chen, Yajun; Liu, Ding; Liang, Junli
2013-10-01
During printing quality inspection, the inspection of color error is an important content. However, the RGB color space is device-dependent, usually RGB color captured from CCD camera must be transformed into CIELAB color space, which is perceptually uniform and device-independent. To cope with the problem, a Markov chain Monte Carlo (MCMC) based algorithms for the RGB to the CIELAB color space transformation is proposed in this paper. Firstly, the modeling color targets and testing color targets is established, respectively used in modeling and performance testing process. Secondly, we derive a Bayesian model for estimation the coefficients of a polynomial, which can be used to describe the relation between RGB and CIELAB color space. Thirdly, a Markov chain is set up base on Gibbs sampling algorithm (one of the MCMC algorithm) to estimate the coefficients of polynomial. Finally, the color difference of testing color targets is computed for evaluating the performance of the proposed method. The experimental results showed that the nonlinear polynomial regression based on MCMC algorithm is effective, whose performance is similar to the least square approach and can accurately model the RGB to the CIELAB color space conversion and guarantee the color error evaluation for printing quality inspection system.
Method for simulating dose reduction in digital mammography using the Anscombe transformation
Borges, Lucas R.; de Oliveira, Helder C. R.; Nunes, Polyana F.; Bakic, Predrag R.; Maidment, Andrew D. A.; Vieira, Marcelo A. C.
2016-01-01
Purpose: This work proposes an accurate method for simulating dose reduction in digital mammography starting from a clinical image acquired with a standard dose. Methods: The method developed in this work consists of scaling a mammogram acquired at the standard radiation dose and adding signal-dependent noise. The algorithm accounts for specific issues relevant in digital mammography images, such as anisotropic noise, spatial variations in pixel gain, and the effect of dose reduction on the detective quantum efficiency. The scaling process takes into account the linearity of the system and the offset of the detector elements. The inserted noise is obtained by acquiring images of a flat-field phantom at the standard radiation dose and at the simulated dose. Using the Anscombe transformation, a relationship is created between the calculated noise mask and the scaled image, resulting in a clinical mammogram with the same noise and gray level characteristics as an image acquired at the lower-radiation dose. Results: The performance of the proposed algorithm was validated using real images acquired with an anthropomorphic breast phantom at four different doses, with five exposures for each dose and 256 nonoverlapping ROIs extracted from each image and with uniform images. The authors simulated lower-dose images and compared these with the real images. The authors evaluated the similarity between the normalized noise power spectrum (NNPS) and power spectrum (PS) of simulated images and real images acquired with the same dose. The maximum relative error was less than 2.5% for every ROI. The added noise was also evaluated by measuring the local variance in the real and simulated images. The relative average error for the local variance was smaller than 1%. Conclusions: A new method is proposed for simulating dose reduction in clinical mammograms. In this method, the dependency between image noise and image signal is addressed using a novel application of the Anscombe
Lin, Yu-Feng; Chen, Jin-Yi
2015-01-01
We developed a computational method to identify NAD- and FAD-binding sites in proteins. First, we extracted from the Protein Data Bank structures of proteins that bind to at least one of these ligands. NAD-/FAD-binding residue templates were then constructed by identifying binding residues through the ligand-binding database BioLiP. The fragment transformation method was used to identify structures within query proteins that resembled the ligand-binding templates. By comparing residue types and their relative spatial positions, potential binding sites were identified and a ligand-binding potential for each residue was calculated. Setting the false positive rate at 5%, our method predicted NAD- and FAD-binding sites at true positive rates of 67.1% and 68.4%, respectively. Our method provides excellent results for identifying FAD- and NAD-binding sites in proteins, and the most important is that the requirement of conservation of residue types and local structures in the FAD- and NAD-binding sites can be verified. PMID:26000290
A new method to calculate the beam charge for an integrating current transformer
Wu Yuchi; Han Dan; Zhu Bin; Dong Kegong; Tan Fang; Gu Yuqiu
2012-09-15
The integrating current transformer (ICT) is a magnetic sensor widely used to precisely measure the charge of an ultra-short-pulse charged particle beam generated by traditional accelerators and new laser-plasma particle accelerators. In this paper, we present a new method to calculate the beam charge in an ICT based on circuit analysis. The output transfer function shows an invariable signal profile for an ultra-short electron bunch, so the function can be used to evaluate the signal quality and calculate the beam charge through signal fitting. We obtain a set of parameters in the output function from a standard signal generated by an ultra-short electron bunch (about 1 ps in duration) at a radio frequency linear electron accelerator at Tsinghua University. These parameters can be used to obtain the beam charge by signal fitting with excellent accuracy.
Dziopa, Florian; Galy, Guillaume; Bauler, Stephanie; Vincent, Benoit; Crochon, Sarah; Tall, Mamadou Lamine; Pirot, Fabrice; Pivot, Christine
2013-06-01
Chemotherapy products in hospitals include a reconstitution step of manufactured drugs providing an adapted dosage to each patient. The administration of highly iatrogenic drugs raises the question of patients' safety and treatment efficiency. In order to reduce administration errors due to faulty preparations, we introduced a new qualitative and quantitative routine control based on Fourier Transform Infrared (FTIR) and UV-Visible spectrophotometry. This automated method enabled fast and specific control for 14 anticancer drugs. A 1.2 mL sample was used to assay and identify each preparation in less than 90 sec. Over a two-year period, 9370 controlled infusion bags showed a 1.49% nonconformity rate, under 15% tolerance from the theoretical concentration and 96% minimum identification matching factor. This study evaluated the reliability of the control process, as well as its accordance to chemotherapy deliverance requirements. Thus, corrective measures were defined to improve the control process. PMID:23014899
A hybrid group method of data handling with discrete wavelet transform for GDP forecasting
NASA Astrophysics Data System (ADS)
Isa, Nadira Mohamed; Shabri, Ani
2013-09-01
This study is proposed the application of hybridization model using Group Method of Data Handling (GMDH) and Discrete Wavelet Transform (DWT) in time series forecasting. The objective of this paper is to examine the flexibility of the hybridization GMDH in time series forecasting by using Gross Domestic Product (GDP). A time series data set is used in this study to demonstrate the effectiveness of the forecasting model. This data are utilized to forecast through an application aimed to handle real life time series. This experiment compares the performances of a hybrid model and a single model of Wavelet-Linear Regression (WR), Artificial Neural Network (ANN), and conventional GMDH. It is shown that the proposed model can provide a promising alternative technique in GDP forecasting.
Isospin-violating nucleon-nucleon forces using the method of unitary transformation
Evgeny Epelbaum; Ulf-G. Meissner
2005-02-01
Recently, we have derived the leading and subleading isospin-breaking three-nucleon forces using the method of unitary transformation. In the present work we extend this analysis and consider the corresponding two-nucleon forces using the same approach. Certain contributions to the isospin-violating one- and two-pion exchange potential have already been discussed by various groups within the effective field theory framework. Our findings agree with the previously obtained results. In addition, we present the expressions for the subleading charge-symmetry-breaking two-pion exchange potential which were not considered before. These corrections turn out to be numerically important. Together with the three-nucleon force results presented in our previous work, the results of the present study specify completely isospin-violating nuclear force up to the order {Lambda}{sup 5}.
Instrumental phase-based method for Fourier transform spectrometer measurements processing
Saggin, Bortolino; Scaccabarozzi, Diego; Tarabini, Marco
2011-04-20
Phase correction is a critical procedure for most space-borne Fourier transform spectrometers (FTSs) whose accuracy (owing to often poor signal-to-noise ratio, SNR) can be jeopardized from many uncontrollable environmental conditions. This work considers the phase correction in an FTS working under significant temperature change during the measurement and affected by mechanical disturbances. The implemented method is based on the identification of an instrumental phase that is dependent on the interferometer temperature and on the extraction of a linear phase component through a least-squares approach. The use of an instrumental phase parameterized with the interferometer temperature eases the determination of the linear phase that can be extracted using only a narrow spectral region selected to be immune from disturbances. The procedure, in this way, is made robust against phase errors arising from instrumental effects, a key feature to reduce the disturbances through spectra averaging. The method was specifically developed for the Mars IR Mapper spectrometer, that was designed for operation onboard a rover on the Mars surface; the validation was performed using ground and in-flight measurements of the Fourier transform IR spectrometer planetary Fourier spectrometer, onboard the MarsExpress mission. The symmetrization has been exploited also for the spectra calibration, highlighting the issues deriving from the cases of relevant beamsplitter emission. The applicability of this procedure to other instruments is conditional to the presence in the spectra of at least one spectral region with a large SNR along with a negligible (or known) beamsplitter emission. For the PFS instrument, the processing of data with relevant beamsplitter emission has been performed exploiting the absorption carbon dioxide bands present in Martian spectra.
Instrumental phase-based method for Fourier transform spectrometer measurements processing.
Saggin, Bortolino; Scaccabarozzi, Diego; Tarabini, Marco
2011-04-20
Phase correction is a critical procedure for most space-borne Fourier transform spectrometers (FTSs) whose accuracy (owing to often poor signal-to-noise ratio, SNR) can be jeopardized from many uncontrollable environmental conditions. This work considers the phase correction in an FTS working under significant temperature change during the measurement and affected by mechanical disturbances. The implemented method is based on the identification of an instrumental phase that is dependent on the interferometer temperature and on the extraction of a linear phase component through a least-squares approach. The use of an instrumental phase parameterized with the interferometer temperature eases the determination of the linear phase that can be extracted using only a narrow spectral region selected to be immune from disturbances. The procedure, in this way, is made robust against phase errors arising from instrumental effects, a key feature to reduce the disturbances through spectra averaging. The method was specifically developed for the Mars IR Mapper spectrometer, that was designed for operation onboard a rover on the Mars surface; the validation was performed using ground and in-flight measurements of the Fourier transform IR spectrometer planetary Fourier spectrometer, onboard the MarsExpress mission. The symmetrization has been exploited also for the spectra calibration, highlighting the issues deriving from the cases of relevant beamsplitter emission. The applicability of this procedure to other instruments is conditional to the presence in the spectra of at least one spectral region with a large SNR along with a negligible (or known) beamsplitter emission. For the PFS instrument, the processing of data with relevant beamsplitter emission has been performed exploiting the absorption carbon dioxide bands present in Martian spectra. PMID:21509063
Desfeux, Christine; Clough, Steven J.; Bent, Andrew F.
2000-01-01
The floral-dip method for Agrobacterium-mediated transformation of Arabidopsis allows efficient plant transformation without need for tissue culture. To facilitate use with other plant species, we investigated the mechanisms that underlie this method. In manual outcrossing experiments, application of Agrobacterium tumefaciens to pollen donor plants did not produce any transformed progeny, whereas application of Agrobacterium to pollen recipient plants yielded transformants at a rate of 0.48%. Agrobacterium strains with T-DNA carrying gusA (encoding β-glucuronidase [GUS]) under the control of 35S, LAT52, or ACT11 promoters revealed delivery of GUS activity to developing ovules, whereas no GUS staining of pollen or pollen tubes was observed. Transformants derived from the same seed pod contained independent T-DNA integration events. In Arabidopsis flowers, the gynoecium develops as an open, vase-like structure that fuses to form closed locules roughly 3 d prior to anthesis. In correlation with this fact, we found that the timing of Agrobacterium infection was critical. Transformants were obtained and GUS staining of ovules and embryo sacs was observed only if the Agrobacterium were applied 5 d or more prior to anthesis. A 6-fold higher rate of transformation was obtained with a CRABS-CLAW mutant that maintains an open gynoecium. Our results suggest that ovules are the site of productive transformation in the floral-dip method, and further suggest that Agrobacterium must be delivered to the interior of the developing gynoecium prior to locule closure if efficient transformation is to be achieved. PMID:10889238
Assessment of the derivative-moment transformation method for unsteady-load estimation
NASA Astrophysics Data System (ADS)
Mohebbian, Ali; Rival, David E.
2012-08-01
It is often difficult, if not impossible, to measure the aerodynamic or hydrodynamic forces on a moving body. For this reason, a classical control-volume technique is typically applied to extract the unsteady forces. However, measuring the acceleration term within the volume of interest using particle image velocimetry (PIV) can be limited by optical access, reflections, as well as shadows. Therefore, in this study, an alternative approach, termed the derivative-moment transformation (DMT) method, is introduced and tested on a synthetic data set produced using numerical simulations. The test case involves the unsteady loading of a flat plate in a two-dimensional, laminar periodic gust. The results suggest that the DMT method can accurately predict the acceleration term so long as appropriate spatial and temporal resolutions are maintained. The major deficiency, which is more dominant for the direction of drag, was found to be the determination of pressure and unsteady terms in the wake. The effect of control-volume size was investigated, suggesting that larger domains work best by minimizing the associated error in the determination of the pressure field. When decreasing the control-volume size, wake vortices, which produce high gradients across the control surfaces, are found to substantially increase the level of error. On the other hand, it was shown that for large control volumes, and with realistic spatial resolution, the accuracy of the DMT method would also suffer. Therefore, a delicate compromise is required when selecting control-volume size in future experiments.
An improved method for broadband interferometric lightning location using wavelet transforms
NASA Astrophysics Data System (ADS)
Qiu, Shi; Zhou, Bi-Hua; Shi, Li-Hua; Dong, Wan-Sheng; Zhang, Yi-Jun; Gao, Tai-Chang
2009-09-01
The principle of VHF broadband interferometer for lightning observations is to extract the phase differences between a pair of RF signals at different frequency components, and thereafter, to compute the direction of the radiation source. However, the phase difference spectra are usually distorted by random noise, which directly affects the location accuracy and reliability. In order to suppress phase interference effectively, a phase filtering algorithm which combines circular correlation with translation-invariant denoising is proposed. Application of the algorithm to a segment of observational data shows that the proposed algorithm does a much better job in recovering the phase spectra than other techniques. Simulated data distorted by the addition of random noise are also used to illustrate the improvements of the method in resolving incident angle, which is compared with other wavelet-based thresholding techniques and the conventional Fourier transform-based cross-correlation method. Finally, this phase filtering algorithm is applied to mapping two natural lightning processes. Contrast analysis reveals that this algorithm could be utilized to retrieve well-defined paths which are not discerned by conventional method, and depict the branches more clearly and precisely.
A combined compensation method for the output voltage of an insulated core transformer power supply
NASA Astrophysics Data System (ADS)
Yang, L.; Yang, J.; Liu, K. F.; Qin, B.; Chen, D. Z.
2014-06-01
An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA.
Clausen, S; Morgenstjerne, A; Rathmann, O
1996-10-01
Surface temperatures are estimated with high precision based on a multitemperature method for Fourier-transform spectrometers. The method is based on Planck's radiation law and a nonlinear least-squares fitting algorithm applied to two or more spectra at different sample temperatures and a single measurement at a known sample temperature, for example, at ambient temperature. The temperature of the sample surface can be measured rather easily at ambient temperature. The spectrum at ambient temperature is used to eliminate background effects from spectra as measured at other surface temperatures. The temperatures of the sample are found in a single calculation from the measured spectra independently of the response function of the instrument and the emissivity of the sample. The spectral emissivity of a sample can be measured if the instrument is calibrated against a blackbody source. Temperatures of blackbody sources are estimated with an uncertainty of 0.2-2 K. The method is demonstrated for measuring the spectral emissivity of a brass specimen and an oxidized nickel specimen. PMID:21127576
A combined compensation method for the output voltage of an insulated core transformer power supply.
Yang, L; Yang, J; Liu, K F; Qin, B; Chen, D Z
2014-06-01
An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA. PMID:24985809
A stochastic Galerkin method for the Euler equations with Roe variable transformation
Pettersson, Per; Iaccarino, Gianluca; Nordström, Jan
2014-01-15
The Euler equations subject to uncertainty in the initial and boundary conditions are investigated via the stochastic Galerkin approach. We present a new fully intrusive method based on a variable transformation of the continuous equations. Roe variables are employed to get quadratic dependence in the flux function and a well-defined Roe average matrix that can be determined without matrix inversion. In previous formulations based on generalized polynomial chaos expansion of the physical variables, the need to introduce stochastic expansions of inverse quantities, or square roots of stochastic quantities of interest, adds to the number of possible different ways to approximate the original stochastic problem. We present a method where the square roots occur in the choice of variables, resulting in an unambiguous problem formulation. The Roe formulation saves computational cost compared to the formulation based on expansion of conservative variables. Moreover, the Roe formulation is more robust and can handle cases of supersonic flow, for which the conservative variable formulation fails to produce a bounded solution. For certain stochastic basis functions, the proposed method can be made more effective and well-conditioned. This leads to increased robustness for both choices of variables. We use a multi-wavelet basis that can be chosen to include a large number of resolution levels to handle more extreme cases (e.g. strong discontinuities) in a robust way. For smooth cases, the order of the polynomial representation can be increased for increased accuracy.
Study on dietary fibre by Fourier transform-infrared spectroscopy and chemometric methods.
Chylińska, Monika; Szymańska-Chargot, Monika; Kruk, Beata; Zdunek, Artur
2016-04-01
Fresh fruit is an important part of the diet of people all over the world as a significant source of water, vitamins and natural sugars. Nowadays it is also one of the main sources of dietary fibre. In fruit the dietary fibre is simply cell wall consisting essentially of polysaccharides. The aim of present study was to predict the contents of pectins, cellulose and hemicelluloses by partial least squares regression (PLS) analysis on the basis of Fourier transform-infrared (FT-IR) spectra of fruit cell wall residue. The second purpose was to analyse the composition of dietary fibre from fruit based on FT-IR spectral information in combination with chemometric methods (principle components analysis (PCA) and hierarchical cluster analysis (HCA)). Additionally the contents of polysaccharides in studied fruits were determined by analytical methods. It has been shown that the analysis of infrared spectra and the use of multivariate statistical methods can be useful for studying the composition of dietary fibre. PMID:26593472
A combined compensation method for the output voltage of an insulated core transformer power supply
Yang, L.; Yang, J. Liu, K. F.; Qin, B.; Chen, D. Z.
2014-06-15
An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA.
NASA Astrophysics Data System (ADS)
Aono, Yuko; Sakurai, Junpei; Shimokohbe, Akira; Hata, Seiichi
2011-06-01
A novel characterization method for the two-way martensitic transformation temperatures of thin-film shape memory alloys (SMAs) is proposed. The method uses thermography to detect the transformation as a change in emissivity. The proposed method was demonstrated for a Ti-Pd-Ni thin-film SMA along with electrical resistivity monitoring. Definite emissivity changes were observed during both heating and cooling. Furthermore, the changes in emissivity corresponded to changes in the electrical resistivity. To confirm the validity of the proposed method, the results were compared with results obtained using conventional differential scanning calorimetry (DSC). The reverse-martensitic transformation temperature was found to agree with the results of the proposed method. However, the martensitic transformation temperature did not agree well. The reason for this disagreement is the differences in the definition of the transformation temperature and stress conditions used. We expect that the proposed method will enable high-throughput characterization of SMAs by a combinatorial approach in the future.
Yan, Chenguang; Hao, Zhiguo; Zhang, Song; Zhang, Baohui; Zheng, Tao
2015-01-01
Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of the proposed method, a 17.3 MJ and a 6.3 MJ arcing fault were simulated on a real full-scale 360MVA/220kV oil-immersed transformer model, respectively. By employing the finite element method, the transformer internal overpressure distribution, wave propagation and von-Mises stress were solved. The numerical results indicate that the increase of pressure and mechanical stress distribution are non-uniform and the stress tends to concentrate on connecting parts of the tank as the fault time evolves. Given this feature, it becomes possible to reduce the risk of transformer tank rupture through limiting the fault energy and enhancing the mechanical strength of the local stress concentrative areas. The theoretical model and numerical simulation method proposed in this paper can be used as a substitute for risky and costly field tests in fault overpressure analysis and tank mitigation design of transformers. PMID:26230392
Yan, Chenguang; Hao, Zhiguo; Zhang, Song; Zhang, Baohui; Zheng, Tao
2015-01-01
Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of the proposed method, a 17.3MJ and a 6.3MJ arcing fault were simulated on a real full-scale 360MVA/220kV oil-immersed transformer model, respectively. By employing the finite element method, the transformer internal overpressure distribution, wave propagation and von-Mises stress were solved. The numerical results indicate that the increase of pressure and mechanical stress distribution are non-uniform and the stress tends to concentrate on connecting parts of the tank as the fault time evolves. Given this feature, it becomes possible to reduce the risk of transformer tank rupture through limiting the fault energy and enhancing the mechanical strength of the local stress concentrative areas. The theoretical model and numerical simulation method proposed in this paper can be used as a substitute for risky and costly field tests in fault overpressure analysis and tank mitigation design of transformers. PMID:26230392
NASA Astrophysics Data System (ADS)
Jones, J. P.; Carniel, R.; Malone, S.
2005-12-01
The time-varying properties of volcanic tremor demand advanced techniques capable of analyzing changes in both time and frequency domains. Specifically, rapid data preprocessing techniques with the ability to distinguish signal from noise are especially valuable in analyzing the temporal, spatial, and spectral properties of these signals. To this end, we use the Discrete Wavelet Packet Transform and the Best Shift Basis algorithm to select an orthonormal basis for continuous volcanic tremor data, then apply a simple statistical test to eliminate frequency bands that primarily consist of Gaussian white noise. We then use the Maximal Overlap Discrete Wavelet Packet Transform to compute and analyze features in the detail coefficients of each "signal" band. Because MODWPT detail coefficients are equivalent to a time series convolved with a zero phase filter, we apply standard polarization and amplitude-based location techniques to each frequency band's detail coefficients to analyze possible source locations and mechanisms. To demonstrate the usefulness of these techniques, we present a sample analysis of data from Erta 'Ale volcano, Ethiopia, recorded on a temporary network in November 2003. Data were sampled at 100 Hz and the DWPT was computed with the LA(16) wavelet to a maximum level of j = 7. The optimal basis for this data set consists of 54 frequency bands, but only 9 contain meaningful "signal" energy. We identify two frequency bands whose locations suggest a distributed source; three frequency bands whose signals may come from the lava lake itself; three high-frequency bands of scattered energy; and one very high frequency band of non-Gaussian instrument noise. Finally, we discuss optimization efforts, computational efficiency, and the feasibility of using similar wavelet methods to preprocess data in real time or near real time.
Xia, D. H.; Huang, M.; Zhou, J.; Rao, J.; Zhuang, G.
2013-10-15
Polarizers are widely used to change the polarization of millimeter waves on the electron cyclotron resonance heating and current drive (ECRH and CD) systems. A new method based on the coordinate transformation and the Fourier expansion (the so-called C-method) has been developed for design of polarizers on the HL-2A ECRH and CD systems. This method transforms the grating problem to an eigenvalue problem, making it easy and clear to understand and solve. The comparison between the C-method, the integral method, and the low power test results is presented. It indicates that the C-method can be considered as a rigorous numerical method for the design of polarizers. Finally, two polarizers were designed based on the C-method which can be used together to achieve almost arbitrary polarization.
Hu, M.; Bai, Y. Z. Zhou, Z. B. Li, Z. X.; Luo, J.
2014-05-15
The capacitive transducer with differential transformer bridge is widely used in ultra-sensitive space accelerometers due to their simple structure and high resolution. In this paper, the front-end electronics of an inductive-capacitive resonant bridge transducer is analyzed. The analysis result shows that the performance of this transducer depends upon the case that the AC pumping frequency operates at the resonance point of the inductive-capacitive bridge. The effect of possible mismatch between the AC pumping frequency and the actual resonant frequency is discussed, and the theoretical analysis indicates that the output voltage noise of the front-end electronics will deteriorate by a factor of about 3 due to either a 5% variation of the AC pumping frequency or a 10% variation of the tuning capacitance. A pre-scanning method to determine the actual resonant frequency is proposed followed by the adjustment of the operating frequency or the change of the tuning capacitance in order to maintain expected high resolution level. An experiment to verify the mismatching effect and the adjustment method is provided.
Image restoration method based on Hilbert transform for full-field optical coherence tomography
NASA Astrophysics Data System (ADS)
Na, Jihoon; Choi, Woo June; Choi, Eun Seo; Ryu, Seon Young; Lee, Byeong Ha
2008-01-01
A full-field optical coherence tomography (FF-OCT) system utilizing a simple but novel image restoration method suitable for a high-speed system is demonstrated. An en-face image is retrieved from only two phase-shifted interference fringe images through using the mathematical Hilbert transform. With a thermal light source, a high-resolution FF-OCT system having axial and transverse resolutions of 1 and 2.2 μm, respectively, was implemented. The feasibility of the proposed scheme is confirmed by presenting the obtained en-face images of biological samples such as a piece of garlic and a gold beetle. The proposed method is robust to the error in the amount of the phase shift and does not leave residual fringes. The use of just two interference images and the strong immunity to phase errors provide great advantages in the imaging speed and the system design flexibility of a high-speed high-resolution FF-OCT system.
NASA Astrophysics Data System (ADS)
Xing, Y. F.; Wang, Y. S.; Shi, L.; Guo, H.; Chen, H.
2016-01-01
According to the human perceptional characteristics, a method combined by the optimal wavelet-packet transform and artificial neural network, so-called OWPT-ANN model, for psychoacoustical recognition is presented. Comparisons of time-frequency analysis methods are performed, and an OWPT with 21 critical bands is designed for feature extraction of a sound, as is a three-layer back-propagation ANN for sound quality (SQ) recognition. Focusing on the loudness and sharpness, the OWPT-ANN model is applied on vehicle noises under different working conditions. Experimental verifications show that the OWPT can effectively transfer a sound into a time-varying energy pattern as that in the human auditory system. The errors of loudness and sharpness of vehicle noise from the OWPT-ANN are all less than 5%, which suggest a good accuracy of the OWPT-ANN model in SQ recognition. The proposed methodology might be regarded as a promising technique for signal processing in the human-hearing related fields in engineering.
[Calculating the stark broadening of welding arc spectra by Fourier transform method].
Pan, Cheng-Gang; Hua, Xue-Ming; Zhang, Wang; Li, Fang; Xiao, Xiao
2012-07-01
It's the most effective and accurate method to calculate the electronic density of plasma by using the Stark width of the plasma spectrum. However, it's difficult to separate Stark width from the composite spectrum linear produced by several mechanisms. In the present paper, Fourier transform was used to separate the Lorentz linear from the spectrum observed, thus to get the accurate Stark width. And we calculated the distribution of the TIG welding arc plasma. This method does not need to measure arc temperature accurately, to measure the width of the plasma spectrum broadened by instrument, and has the function to reject the noise data. The results show that, on the axis, the electron density of TIG welding arc decreases with the distance from tungsten increasing, and changes from 1.21 X 10(17) cm(-3) to 1.58 x 10(17) cm(-3); in the radial, the electron density decreases with the distance from axis increasing, and near the tungsten zone the biggest electronic density is off axis. PMID:23016315
NASA Astrophysics Data System (ADS)
Tan, Zhi-Zhong
2015-05-01
We develop a general recursion-transform (R-T) method for a two-dimensional resistor network with a zero resistor boundary. As applications of the R-T method, we consider a significant example to illuminate the usefulness for calculating resistance of a rectangular m ×n resistor network with a null resistor and three arbitrary boundaries, a problem never solved before, since Green's function techniques and Laplacian matrix approaches are invalid in this case. Looking for the exact calculation of the resistance of a binary resistor network is important but difficult in the case of an arbitrary boundary since the boundary is like a wall or trap which affects the behavior of finite network. In this paper we obtain several general formulas of resistance between any two nodes in a nonregular m ×n resistor network in both finite and infinite cases. In particular, 12 special cases are given by reducing one of the general formulas to understand its applications and meanings, and an integral identity is found when we compare the equivalent resistance of two different structures of the same problem in a resistor network.
Method for calibrating a Fourier transform ion cyclotron resonance mass spectrometer
Smith, Richard D.; Masselon, Christophe D.; Tolmachev, Aleksey
2003-08-19
A method for improving the calibration of a Fourier transform ion cyclotron resonance mass spectrometer wherein the frequency spectrum of a sample has been measured and the frequency (f) and intensity (I) of at least three species having known mass to charge (m/z) ratios and one specie having an unknown (m/z) ratio have been identified. The method uses the known (m/z) ratios, frequencies, and intensities at least three species to calculate coefficients A, B, and C, wherein the mass to charge ratio of a least one of the three species (m/z).sub.i is equal to ##EQU1## wherein f.sub.i is the detected frequency of the specie, G(I.sub.i) is a predetermined function of the intensity of the species, and Q is a predetermined exponent. Using the calculated values for A, B, and C, the mass to charge ratio of the unknown specie (m/z).sub.ii is calculated as the sum of ##EQU2## wherein f.sub.ii is the measured frequency of the unknown specie, and (I.sub.ii) is the measured intensity of the unknown specie.
A Fractal Dimension and Wavelet Transform Based Method for Protein Sequence Similarity Analysis.
Yang, Lina; Tang, Yuan Yan; Lu, Yang; Luo, Huiwu
2015-01-01
One of the key tasks related to proteins is the similarity comparison of protein sequences in the area of bioinformatics and molecular biology, which helps the prediction and classification of protein structure and function. It is a significant and open issue to find similar proteins from a large scale of protein database efficiently. This paper presents a new distance based protein similarity analysis using a new encoding method of protein sequence which is based on fractal dimension. The protein sequences are first represented into the 1-dimensional feature vectors by their biochemical quantities. A series of Hybrid method involving discrete Wavelet transform, Fractal dimension calculation (HWF) with sliding window are then applied to form the feature vector. At last, through the similarity calculation, we can obtain the distance matrix, by which, the phylogenic tree can be constructed. We apply this approach by analyzing the ND5 (NADH dehydrogenase subunit 5) protein cluster data set. The experimental results show that the proposed model is more accurate than the existing ones such as Su's model, Zhang's model, Yao's model and MEGA software, and it is consistent with some known biological facts. PMID:26357222
Tan, Zhi-Zhong
2015-05-01
We develop a general recursion-transform (R-T) method for a two-dimensional resistor network with a zero resistor boundary. As applications of the R-T method, we consider a significant example to illuminate the usefulness for calculating resistance of a rectangular m×n resistor network with a null resistor and three arbitrary boundaries, a problem never solved before, since Green's function techniques and Laplacian matrix approaches are invalid in this case. Looking for the exact calculation of the resistance of a binary resistor network is important but difficult in the case of an arbitrary boundary since the boundary is like a wall or trap which affects the behavior of finite network. In this paper we obtain several general formulas of resistance between any two nodes in a nonregular m×n resistor network in both finite and infinite cases. In particular, 12 special cases are given by reducing one of the general formulas to understand its applications and meanings, and an integral identity is found when we compare the equivalent resistance of two different structures of the same problem in a resistor network. PMID:26066134
NASA Astrophysics Data System (ADS)
Hu, M.; Bai, Y. Z.; Zhou, Z. B.; Li, Z. X.; Luo, J.
2014-05-01
The capacitive transducer with differential transformer bridge is widely used in ultra-sensitive space accelerometers due to their simple structure and high resolution. In this paper, the front-end electronics of an inductive-capacitive resonant bridge transducer is analyzed. The analysis result shows that the performance of this transducer depends upon the case that the AC pumping frequency operates at the resonance point of the inductive-capacitive bridge. The effect of possible mismatch between the AC pumping frequency and the actual resonant frequency is discussed, and the theoretical analysis indicates that the output voltage noise of the front-end electronics will deteriorate by a factor of about 3 due to either a 5% variation of the AC pumping frequency or a 10% variation of the tuning capacitance. A pre-scanning method to determine the actual resonant frequency is proposed followed by the adjustment of the operating frequency or the change of the tuning capacitance in order to maintain expected high resolution level. An experiment to verify the mismatching effect and the adjustment method is provided.
Hu, M; Bai, Y Z; Zhou, Z B; Li, Z X; Luo, J
2014-05-01
The capacitive transducer with differential transformer bridge is widely used in ultra-sensitive space accelerometers due to their simple structure and high resolution. In this paper, the front-end electronics of an inductive-capacitive resonant bridge transducer is analyzed. The analysis result shows that the performance of this transducer depends upon the case that the AC pumping frequency operates at the resonance point of the inductive-capacitive bridge. The effect of possible mismatch between the AC pumping frequency and the actual resonant frequency is discussed, and the theoretical analysis indicates that the output voltage noise of the front-end electronics will deteriorate by a factor of about 3 due to either a 5% variation of the AC pumping frequency or a 10% variation of the tuning capacitance. A pre-scanning method to determine the actual resonant frequency is proposed followed by the adjustment of the operating frequency or the change of the tuning capacitance in order to maintain expected high resolution level. An experiment to verify the mismatching effect and the adjustment method is provided. PMID:24880402
NASA Astrophysics Data System (ADS)
Colgan, J.; Pindzola, M. S.; Robicheaux, F.
2002-07-01
A formulation of the time-dependent close-coupling theory is described which allows efficient calculation of the total ionization cross section for many electron energies. The Fourier transform method is applied to the electron-impact ionization of Li2+ and excellent agreement is found with experiment and a distorted-wave method.
Kitsak, M A; Kitsak, A I
2008-04-30
The cross modulation method of transformation of the spatial coherence of low-power pulsed laser radiation in a nonlinear medium is proposed. The method is realised experimentally in a multimode optical fibre. The estimates of the degree of spatial coherence of radiation subjected to the phase cross modulation demonstrated the high efficiency of this radiation decorrelation mechanism. (control of laser radiation parameters)
NASA Astrophysics Data System (ADS)
Cruz Hernández, Andrés; Campos Guillén, Juan
2012-09-01
Physical methods for genetic transformation in plants. The most commonly applied methods in plant transformation include Agrobacterium infection and protoplast or microprojectile bombardment. A plant transformation system is a prerequisite for the development of a plant improvement program. The global area utilized for biotech crops increases every year.
Clark, James E; Osborne, Jason W; Gallagher, Peter; Watson, Stuart
2016-07-01
Neuroendocrine data are typically positively skewed and rarely conform to the expectations of a Gaussian distribution. This can be a problem when attempting to analyse results within the framework of the general linear model, which relies on assumptions that residuals in the data are normally distributed. One frequently used method for handling violations of this assumption is to transform variables to bring residuals into closer alignment with assumptions (as residuals are not directly manipulated). This is often attempted through ad hoc traditional transformations such as square root, log and inverse. However, Box and Cox (Box & Cox, ) observed that these are all special cases of power transformations and proposed a more flexible method of transformation for researchers to optimise alignment with assumptions. The goal of this paper is to demonstrate the benefits of the infinitely flexible Box-Cox transformation on neuroendocrine data using syntax in spss. When applied to positively skewed data typical of neuroendocrine data, the majority (~2/3) of cases were brought into strict alignment with Gaussian distribution (i.e. a non-significant Shapiro-Wilks test). Those unable to meet this challenge showed substantial improvement in distributional properties. The biggest challenge was distributions with a high ratio of kurtosis to skewness. We discuss how these cases might be handled, and we highlight some of the broader issues associated with transformation. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27230811
NASA Astrophysics Data System (ADS)
Bossu, Jérémie; Gée, Christelle; Guillemin, Jean-Philippe; Truchetet, Frédéric
2006-02-01
This paper presents two spatial methods to discriminate between crop and weeds. The application is related to agronomic image with perspective crop rows. The first method uses a double Hough Transform permitting a detection of crop rows and a classification between crop and weeds. The second method is based on Gabor filtering, a band pass filter. The parameters of this filter are detected from a Fast Fourier Transform of the image. For each method, a weed infestation rate is obtained. The two methods are compared and a discussion concludes about the abilities of these methods to detect the crop rows in agronomic images. Finally, we discuss this method regarding the capability of the spatial approach for classifying weeds from crop.
Lee, Jongsuh; Hussain, Syed Hassaan; Wang, Semyung Park, Kyihwan
2014-09-15
Generally, it is time consuming to experimentally identify the operating deflection shape or mode shape of a structure. To overcome this problem, the Hilbert Huang transform (HHT) technique has been recently proposed. This technique is used to extract the mode shape from measurements that continuously measure the vibration of a region of interest within a structure using a non-contact laser sensor. In previous research regarding the HHT, two technical processes were needed to obtain the mode shape for each mode. The purpose of this study is to improve and complement our previous research, and for this purpose, a modal analysis approach is adapted without using the two technical processes to obtain an accurate un-damped impulse response of each mode for continuous scanning measurements. In addition, frequency response functions for each type of beam are derived, making it possible to make continuously scanned measurements along a straight profile. In this paper, the technical limitations and drawbacks of the damping compensation technique used in previous research are identified. In addition, the separation of resonant frequency (the Doppler effect) that occurs in continuous scanning measurements and the separation of damping phenomenon are also observed. The proposed method is quantitatively verified by comparing it with the results obtained from a conventional approach to estimate the mode shape with an impulse response.
Lee, Jongsuh; Hussain, Syed Hassaan; Wang, Semyung; Park, Kyihwan
2014-09-01
Generally, it is time consuming to experimentally identify the operating deflection shape or mode shape of a structure. To overcome this problem, the Hilbert Huang transform (HHT) technique has been recently proposed. This technique is used to extract the mode shape from measurements that continuously measure the vibration of a region of interest within a structure using a non-contact laser sensor. In previous research regarding the HHT, two technical processes were needed to obtain the mode shape for each mode. The purpose of this study is to improve and complement our previous research, and for this purpose, a modal analysis approach is adapted without using the two technical processes to obtain an accurate un-damped impulse response of each mode for continuous scanning measurements. In addition, frequency response functions for each type of beam are derived, making it possible to make continuously scanned measurements along a straight profile. In this paper, the technical limitations and drawbacks of the damping compensation technique used in previous research are identified. In addition, the separation of resonant frequency (the Doppler effect) that occurs in continuous scanning measurements and the separation of damping phenomenon are also observed. The proposed method is quantitatively verified by comparing it with the results obtained from a conventional approach to estimate the mode shape with an impulse response. PMID:25273766
de Vetten, Nick; Wolters, Anne-Marie; Raemakers, Krit; van der Meer, Ingrid; ter Stege, Renaldo; Heeres, Els; Heeres, Paul; Visser, Richard
2003-04-01
It is generally thought that transformation of plant cells using Agrobacterium tumefaciens occurs at a very low frequency. Therefore, selection marker genes are used to identify the rare plants that have taken up foreign DNA. Genes encoding antibiotic and herbicide resistance are widely used for this purpose in plant transformation. Over the past several years, consumer and environmental groups have expressed concern about the use of antibiotic- and herbicide-resistance genes from an ecological and food safety perspective. Although no scientific basis has been determined for these concerns, generating marker-free plants would certainly contribute to the public acceptance of transgenic crops. Several methods have been reported to create marker gene-free transformed plants, for example co-transformation, transposable elements, site-specific recombination, or intrachromosomal recombination. Not only are most of these systems time-consuming and inefficient, but they are also employed on the assumption that isolation of transformants without a selective marker gene is not feasible. Here we present a method that permits the identification of transgenic plants without the use of selectable markers. This strategy relies on the transformation of tissue explants or cells with a virulent A. tumefaciens strain and selection of transformed cells or shoots after PCR analysis. Incubation of potato explants with A. tumefaciens strain AGL0 resulted in transformed shoots at an efficiency of 1-5% of the harvested shoots, depending on the potato genotype used. Because this system does not require genetic segregation or site-specific DNA-deletion systems to remove marker genes, it may provide a reliable and efficient tool for generating transgenic plants for commercial use, especially in vegetatively propagated species like potato and cassava. PMID:12627169
Mehta, N C; Scharlemann, E T; Stevens, C G
2001-04-02
Application of a novel transform operator, the Sticklet transform, to the quantitative estimation of trace chemicals in industrial effluent plumes is reported. The sticklet transform is a superset of the well-known derivative operator and the Haar wavelet, and is characterized by independently adjustable lobe width and separation. Computer simulations demonstrate that they can make accurate and robust concentration estimates of multiple chemical species in industrial effluent plumes in the presence of strong clutter background, interferent chemicals and random noise. In this paper they address the application of the sticklet transform in estimating chemical concentrations in effluent plumes in the presence of atmospheric transmission effects. They show that this transform retains the ability to yield accurate estimates using on-plume/off-plume measurements that represent atmospheric differentials up to 10% of the full atmospheric attenuation.
On the Estimation of T-Wave Alternans Using the Spectral Fast Fourier Transform Method
Armoundas, Antonis A; Mela, Theofanie; Merchant, Faisal M
2012-01-01
BACKGROUND T-wave alternans (TWA), has been associated with increased vulnerability to ventricular tachyarrhythmias and sudden cardiac death (SCD). However, both random (white) noise and (patho)physiologic processes (i.e. premature ventricular contractions [PVCs], heart and respiration rates) may hamper TWA estimation and therefore, lessen its clinical utility for risk stratification. OBJECTIVE To investigate the effect of random noise and certain (patho)physiologic processes on the estimation of TWA using the Fast Fourier Transform (FFT) method and to develop methods to overcome these potential sources of error. METHODS We used a combination of human electrocardiogram data and computer simulations to assess the effects of a PVC, random and colored noise on the accuracy of TWA estimation. RESULTS We quantitatively demonstrate that replacing a “bad” beat with an odd/even median beat is a more accurate approach than replacing it with the overall average or the overall median beat. We also show that phase resetting may have a significant effect on alternans estimation and that estimation of alternans using frequencies greater than 0.4922 cycles/beat in a 128-point FFT provides the most accurate approach for estimating the alternans when phase resetting is likely to occur. Additionally, our data demonstrate that the number of indeterminate TWA tests due to high levels of noise can be reduced when the alternans voltage exceeds a new higher threshold. Also, the amplitude of random noise has a significant effect on alternans estimation and should be considered to adjust the alternans voltage threshold for noise levels greater than 1.8 μV. Finally, we quantitatively demonstrate that colored noise may lead to a false positive or a false negative result. We propose methods to estimate the effect of these (patho)physiologic processes on the alternans estimation in order to determine whether a TWA test is likely to be a true positive or a true negative. CONCLUSION This
NASA Astrophysics Data System (ADS)
Giachetti, A.; Daffara, C.; Reghelin, C.; Gobbetti, E.; Pintus, R.
2015-06-01
In this paper we analyze some problems related to the acquisition of multiple illumination images for Polynomial Texture Maps (PTM) or generic Reflectance Transform Imaging (RTI). We show that intensity and directionality nonuniformity can be a relevant issue when acquiring manual sets of images with the standard highlight-based setup both using a flash lamp and a LED light. To maintain a cheap and flexible acquisition setup that can be used on field and by non-experienced users we propose to use a dynamic calibration and correction of the lights based on multiple intensity and direction estimation around the imaged object during the acquisition. Preliminary tests on the results obtained have been performed by acquiring a specifically designed 3D printed pattern in order to see the accuracy of the acquisition obtained both for spatial discrimination of small structures and normal estimation, and on samples of different types of paper in order to evaluate material discrimination. We plan to design and build from our analysis and from the tools developed and under development a set of novel procedures and guidelines that can be used to turn the cheap and common RTI acquisition setup from a simple way to enrich object visualization into a powerful method for extracting quantitative characterization both of surface geometry and of reflective properties of different materials. These results could have relevant applications in the Cultural Heritage domain, in order to recognize different materials used in paintings or investigate the ageing status of artifacts' surface.
NASA Astrophysics Data System (ADS)
Tachioka, Yuuki; Narita, Tomohiro; Watanabe, Shinji
2015-12-01
The recently released REverberant Voice Enhancement and Recognition Benchmark (REVERB) challenge includes a reverberant automatic speech recognition (ASR) task. This paper describes our proposed system based on multi-channel speech enhancement preprocessing and state-of-the-art ASR techniques. For preprocessing, we propose a single-channel dereverberation method with reverberation time estimation, which is combined with multichannel beamforming that enhances direct sound compared with the reflected sound. In addition, this paper also focuses on state-of-the-art ASR techniques such as discriminative training of acoustic models including the Gaussian mixture model, subspace Gaussian mixture model, and deep neural networks, as well as various feature transformation techniques. Although, for the REVERB challenge, it is necessary to handle various acoustic environments, a single ASR system tends to be overly tuned for a specific environment, which degrades the performance in the mismatch environments. To overcome this mismatch problem with a single ASR system, we use a system combination approach using multiple ASR systems with different features and different model types because a combination of various systems that have different error patterns is beneficial. In particular, we use our discriminative training technique for system combination that achieves better generalization by making systems complementary with the modified discriminative criteria. Experiments show the effectiveness of these approaches, reaching 6.76 and 18.60 % word error rates on the REVERB simulated and real test sets. These are 68.8 and 61.5 % relative improvements over the baseline.
Finite element method for conserved phase fields: Stress-mediated diffusional phase transformation
NASA Astrophysics Data System (ADS)
Zaeem, Mohsen Asle; Mesarovic, Sinisa Dj.
2010-12-01
Phase-field models with conserved phase-field variables result in a 4th order evolution partial differential equation (PDE). When coupled with the usual 2nd order thermo-mechanics equations, such problems require special treatment. In the past, the finite element method (FEM) has been successfully applied to non-conserved phase fields, governed by a 2nd order PDE. For higher order equations, the convergence of the standard Galerkin FEM requires that the interpolation functions belong to a higher continuity class. We consider the Cahn-Hilliard phase-field model for diffusion-controlled solid state phase transformation in binary alloys, coupled with elasticity of the solid phases. A Galerkin finite element formulation is developed, with mixed-order interpolation: C 0 interpolation functions for displacements, and C 1 interpolation functions for the phase-field variable. To demonstrate convergence of the mixed interpolation scheme, we first study a one-dimensional problem - nucleation and growth of the intermediate phase in a thin-film diffusion couple with elasticity effects. Then, we study the effects of completeness of C 1 interpolation on parabolic problems in two space dimensions by considering the growth of the intermediate phase in a binary system. Quadratic convergence, expected for conforming elements, is achieved for both one- and two-dimensional systems.
Fourier-transform method of data compression and temporal fringe pattern analysis
Tuck Wah Ng; Kar Tien Ang
2005-11-20
Temporal fringe pattern analysis is invaluable in studies of transient phenomena but necessitates large data storage for two essential sets of data, i.e., fringe pattern intensity and deformation phase. We describe a compression scheme based on the Fourier-transform method for temporal fringe data storage that permits retrieval of both the intensity and the deformation phase. When the scheme was used with simulated temporal wavefront interferometry intensity fringe patterns, a high compression ratio of 10.77 was achieved, with a significant useful data ratio of 0.859. The average root-mean-square error in phase value restored was a low 0.0015 rad. With simulated temporal speckle interferometry intensity fringe patterns, the important paremeters varied with the modulation cutoff value applied. For a zero modulation cutoff value, the ratio of data points and the compression ratio values obtained were roughly the same as in wavelength interferometry, albeit the average root-mean-square error in the phase value restored was far higher. By increasing the modulation cutoff value we attained significant reduction and increase in the ratio of data points and the compression ratio, respectively, whereas the average root-mean-square error in the restored phase values was reduced only slightly.
Method for distinguishing normal and transformed cells using G1 kinase inhibitors
Crissman, Harry A.; Gadbois, Donna M.; Tobey, Robert A.; Bradbury, E. Morton
1993-01-01
A G.sub.1 phase kinase inhibitor is applied in a low concentration to a population of normal and transformed mammalian cells. The concentration of G.sub.1 phase kinase inhibitor is selected to reversibly arrest normal mammalian cells in the G.sub.1 cell cycle without arresting growth of transformed cells. The transformed cells may then be selectively identified and/or cloned for research or diagnostic purposes. The transformed cells may also be selectively killed by therapeutic agents that do not affect normal cells in the G.sub.1 phase, suggesting that such G.sub.1 phase kinase inhibitors may form an effective adjuvant for use with chemotherapeutic agents in cancer therapy for optimizing the killing dose of chemotherapeutic agents while minimizing undesirable side effects on normal cells.
Method for distinguishing normal and transformed cells using G1 kinase inhibitors
Crissman, H.A.; Gadbois, D.M.; Tobey, R.A.; Bradbury, E.M.
1991-12-31
A G{sub 1} phase kinase inhibitor is applied in a low concentration to a population of normal and transformed mammalian cells. The concentration of G{sub 1} phase kinase inhibitor is selected to reversibly arrest normal mammalian cells in the G{sub 1} cell cycle without arresting growth of transformed cells. The transformed cells may then be selectively identified and/or cloned for research or diagnostic purposes. The transformed cells may also be selectively killed by therapeutic agents that do not affect normal cells in the G{sub 1} phase, suggesting that such G{sub 1} phase kinase inhibitors may form an effective adjuvant for use with chemotherapeutic agents in cancer therapy for optimizing the killing dose of chemotherapeutic agents while minimizing undesirable side effects on normal cells.
Method for distinguishing normal and transformed cells using G1 kinase inhibitors
Crissman, H.A.; Gadbois, D.M.; Tobey, R.A.; Bradbury, E.M.
1993-02-09
A G[sub 1] phase kinase inhibitor is applied in a low concentration to a population of normal and transformed mammalian cells. The concentration of G[sub 1] phase kinase inhibitor is selected to reversibly arrest normal mammalian cells in the G[sub 1] cell cycle without arresting growth of transformed cells. The transformed cells may then be selectively identified and/or cloned for research or diagnostic purposes. The transformed cells may also be selectively killed by therapeutic agents that do not affect normal cells in the G[sub 1] phase, suggesting that such G[sub 1] phase kinase inhibitors may form an effective adjuvant for use with chemotherapeutic agents in cancer therapy for optimizing the killing dose of chemotherapeutic agents while minimizing undesirable side effects on normal cells.
NASA Astrophysics Data System (ADS)
Silenko, Alexander J.
2015-02-01
A general method of the Foldy-Wouthuysen transformation is developed. This method is applicable to relativistic particles with any spin in arbitrarily strong external fields. It can be used when the de Broglie wavelength is much smaller than the characteristic distance. Contrary to previously developed relativistic methods, the present method satisfies the condition of the exact Foldy-Wouthuysen transformation and is well substantiated. The derived relativistic Foldy-Wouthuysen Hamiltonian is expanded in powers of the Planck constant. In this expansion, terms proportional to the zero and first powers are determined exactly in accordance with the above condition, and terms proportional to higher powers are not specified. The obtained result agrees with the corresponding formula for the Foldy-Wouthuysen Hamiltonian previously deduced by an iterative relativistic method and proves the validity of results obtained with this formula.
NASA Astrophysics Data System (ADS)
Piecuch, Piotr; Włoch, Marta
2005-12-01
Completely renormalized (CR) coupled-cluster (CC) approaches, such as CR-CCSD(T), in which one corrects the standard CC singles and doubles (CCSD) energy for the effects of triply (T) and other higher-than-doubly excited clusters [K. Kowalski and P. Piecuch, J. Chem. Phys. 113, 18 (2000)], are reformulated in terms of the left eigenstates ⟨Φ∣L of the similarity-transformed Hamiltonian of CC theory. The resulting CR-CCSD(T)L or CR-CC(2,3) and other CR-CCL methods are derived from the new biorthogonal form of the method of moments of CC equations (MMCC) in which, in analogy to the original MMCC theory, one focuses on the noniterative corrections to standard CC energies that recover the exact, full configuration-interaction energies. One of the advantages of the biorthogonal MMCC theory, which will be further analyzed and extended to excited states in a separate paper, is a rigorous size extensivity of the basic ground-state CR-CCL approximations that result from it, which was slightly violated by the original CR-CCSD(T) and CR-CCSD(TQ) approaches. This includes the CR-CCSD(T)L or CR-CC(2,3) method discussed in this paper, in which one corrects the CCSD energy by the relatively inexpensive noniterative correction due to triples. Test calculations for bond breaking in HF, F2, and H2O indicate that the noniterative CR-CCSD(T)L or CR-CC(2,3) approximation is very competitive with the standard CCSD(T) theory for nondegenerate closed-shell states, while being practically as accurate as the full CC approach with singles, doubles, and triples in the bond-breaking region. Calculations of the activation enthalpy for the thermal isomerizations of cyclopropane involving the trimethylene biradical as a transition state show that the noniterative CR-CCSD(T)L approximation is capable of providing activation enthalpies which perfectly agree with experiment.
NASA Astrophysics Data System (ADS)
Mehrabi Pari, Sharareh; Javidan, Kurosh; Taghavi Shahri, Fatemeh
2016-05-01
The "Laplace Transform Method" is used to solve the Fokker-Plank equation for finding the time evolution of the heavy quarks distribution functions such as charm and bottom in quark gluon plasma. These solutions will lead us to calculation of nuclear suppression factor RAA. The results have good agreement with available experiment data from the PHENIX collaboration.
ERIC Educational Resources Information Center
Atkinson Duina, Angela
2013-01-01
New regulations attached to ARRA funding of federal School Improvement Fund grants aimed at producing rapid turnaround of low performing schools were highly criticized as unsuitable for rural schools. This mixed-methods study looked at the implementation of the School Improvement Fund Transformation Model in two rural Maine high schools during the…
Koelling, S.; Epelbaum, E.; Krebs, H.; Meissner, U.-G.
2009-10-15
We derive the leading two-pion-exchange contributions to the two-nucleon electromagnetic current operator in the framework of chiral effective field theory using the method of unitary transformation. Explicit results for the current and charge densities are given in momentum and coordinate space.
[A novel hyperspectra absorption enhancing method based on morphological top-hat transformation].
Li, Hui; Lin, Qi-zhong; Wang, Qin-jun; Liu, Qing-jie; Chen, Yu
2010-09-01
Hyperspectral characteristics analysis of ground features is the basis for applications of high-resolution imaging technology to ground target identification and ground features classification. Based on morphological multi-scale Top-Hat transformation, a novel spectral absorption enhancing algorithms was put forward, which enhanced spectral absorption features while maintaining shape features of the absorption peak bands. Eleven reflectance spectra of different mineral groups were chosen from the mineral spectral library of the United States Geological Survey (USGS), and we used a K-means clustering analysis on both the absorption-enhanced spectra and the original reflectance spectra. Results showed that, firstly, clustering groups of the absorption-enhanced spectra (AES) had better similarity within the same clustering group, and greater difference between different groups, furthermore, they were more consistent with the geological background of these minerals compared with clustering result of the original spectra (OS). Secondly, while all the original spectra were re-sampled to their ASTER spectra and the AES clustering result was displayed in the form of ASTER spectra of the minerals, we could easily describe both the representative spectral feature of each clustering group, and the typical spectral differences between every two groups. These fully demonstrate that the absorption-enhanced spectra have enhanced absorption features of the mineral spectra, and improved the separability of hyper-spectra. Accordingly, feature analysis based on absorption enhanced spectra can be used as reference for information extracting based on multi-spectral remote sensing image data, and it is a very useful method of hyperspectral analysis. PMID:21105412
Gravel, D.; Rilling, A.; Karfik, V.; Schmaeh, M.
1997-12-31
Monitoring extremely low limits of pollutants in the stack emissions of waste incinerators is required by German law (and recently by European Community regulations). This calls for the most advanced and innovative monitoring equipment. Fourier Transform Infrared Spectrometers designed for use in industrial environments can now meet this need. The operating principle and construction of an FTIR-based continuous emissions multicomponent monitoring system will be explained. This FTIR spectrometer provides quantitative results of 9 chemical compounds simultaneously. This number can be increased by simple software addition. The hot/wet, extractive analytical method provides accurate results at extremely low concentration levels for pollutants like HCl, SO{sub 2} and NH{sub 3}, even with up to 60 Vol% water vapor in the gas sample. The combination of FTIR spectrometry and modern chemometrics gives higher selectivity than any other analyzer. The excellent long-term stability allows extending the calibration interval to six months. The ruggedness of industrial grade FTIR Spectrometer and the simple design of the sampling and gas conditioning systems ensure extremely high availability. The performance of the FTIR spectrometer has been validated by an independent products testing organization, TUV Rheinland Germany. The testing includes a laboratory examination and a long term trial under real working conditions. As a result, the FTIR based system Cemas achieved the official permission for emission monitoring by the German Federal Ministry of Environment and Reactor Security. The experience and particular results obtained from the operation of more than 70 FTIR continuous emissions monitoring systems throughout the world will be presented.
Lassen, J; Løvendahl, P; Madsen, J
2012-02-01
Individual methane (CH(4)) production was recorded repeatedly on 93 dairy cows during milking in an automatic milking system (AMS), with the aim of estimating individual cow differences in CH(4) production. Methane and CO(2) were measured with a portable air sampler and analyzer unit based on Fourier transform infrared (FTIR) detection. The cows were 50 Holsteins and 43 Jerseys from mixed parities and at all stages of lactation (mean=156 d in milk). Breath was captured by the FTIR unit inlet nozzle, which was placed in front of the cow's head in each of the 2 AMS as an admixture to normal barn air. The FTIR unit was running continuously for 3 d in each of 2 AMS units, 1 with Holstein and another with Jersey cows. Air was analyzed every 20 s. From each visit of a cow to the AMS, CH(4) and CO(2) records were summarized into the mean, median, 75, and 90% quantiles. Furthermore, the ratio between CH(4) and CO(2) was used as a derived measure with the idea of using CO(2) in breath as a tracer gas to quantify the production of methane. Methane production records were analyzed with a mixed model, containing cow as random effect. Fixed effects of milk yield and daily intake of the total mixed ration and concentrates were also estimated. The repeatability of the CH(4)-to-CO(2) ratio was 0.39 for Holsteins and 0.34 for Jerseys. Both concentrate intake and total mixed ration intake were positively related to CH(4) production, whereas milk production level was not correlated with CH(4) production. In conclusion, the results from this study suggest that the CH(4)-to-CO(2) ratio measured using the noninvasive method is an asset of the individual cow and may be useful in both management and genetic evaluations. PMID:22281353
Watts, Benjamin
2014-09-22
An algorithm is presented for the calculation of the Kramers-Kronig transform of a spectrum via a piecewise Laurent polynomial method. This algorithm is demonstrated to be highly accurate, while also being computationally efficient. The algorithm places no requirements on data point spacing and is capable of integrating across the full spectrum (i.e. from zero to infinity). Further, we present a computer application designed to aid in calculating the Kramers-Kronig transform on near-edge experimental X-ray absorption spectra (extended with atomic scattering factor data) in order to produce the dispersive part of the X-ray refractive index, including near-edge features. PMID:25321829
Fourier transform infrared spectroscopy as a method to study lipid accumulation in oleaginous yeasts
2014-01-01
Background Oleaginous microorganisms, such as different yeast and algal species, can represent a sustainable alternative to plant oil for the production of biodiesel. They can accumulate fatty acids (FA) up to 70% of their dry weight with a predominance of (mono)unsaturated species, similarly to what plants do, but differently from animals. In addition, their growth is not in competition either with food, feed crops, or with agricultural land. Despite these advantages, the exploitation of the single cell oil system is still at an early developmental stage. Cultivation mode and conditions, as well as lipid extraction technologies, represent the main limitations. The monitoring of lipid accumulation in oleaginous microorganisms is consequently crucial to develop and validate new approaches, but at present the majority of the available techniques is time consuming, invasive and, when relying on lipid extraction, can be affected by FA degradation. Results In this work the fatty acid accumulation of the oleaginous yeasts Cryptococcus curvatus and Rhodosporidium toruloides and of the non-oleaginous yeast Saccharomyces cerevisiae (as a negative control) was monitored in situ by Fourier Transform Infrared Spectroscopy (FTIR). Indeed, this spectroscopic tool can provide complementary information to those obtained by classical techniques, such as microscopy, flow cytometry and gas chromatography. As shown in this work, through the analysis of the absorption spectra of intact oleaginous microorganisms it is possible not only to monitor the progression of FA accumulation but also to identify the most represented classes of the produced lipids. Conclusions Here we propose FTIR microspectroscopy - supported by multivariate analysis - as a fast, reliable and non invasive method to monitor and analyze FA accumulation in intact oleaginous yeasts. The results obtained by the FTIR approach were in agreement with those obtained by the other classical methods like flow cytometry and
Paz, Margie M; Martinez, Juan Carlos; Kalvig, Andrea B; Fonger, Tina M; Wang, Kan
2006-03-01
The utility of transformation for soybean improvement requires an efficient system for production of stable transgenic lines. We describe here an improved cotyledonary node method using an alternative explant for Agrobacterium tumefaciens-mediated soybean transformation. We use the term "half-seed" to refer to this alternative cotyledonary explant that is derived from mature seed of soybean following an overnight imbibition and to distinguish it from cotyledonary node derived from 5-7-day-old seedlings. Transformation efficiencies using half-seed explants ranged between 1.4 and 8.7% with an overall efficiency of 3.8% based on the number of transformed events that have been confirmed in the T1 generation by phenotypic assay using the herbicide Liberty (active ingredient glufosinate) and by Southern analysis. This efficiency is 1.5-fold higher than the cotyledonary node method used in our laboratory. Significantly, the half-seed system is simple and does not require deliberate wounding of explants, which is a critical and technically demanding step in the cotyledonary node method. PMID:16249869
NASA Technical Reports Server (NTRS)
Munoz, R. M. (Inventor)
1974-01-01
An input analog signal to be frequency analyzed is separated into N number of simultaneous analog signal components each identical to the original but delayed relative to the original by a successively larger time delay. The separated and delayed analog components are combined together in a suitable number of adders and attenuators in accordance with at least one component product of the continuous Fourier transform and analog signal matrices to separate the analog input signal into at least one of its continuous analog frequency components of bandwidth 1/N times the bandwidth of the original input signal. The original analog input signal can be reconstituted by combining the separate analog frequency components in accordance with the component products of the continuous Fourier transform and analog frequency component matrices. The continuous Fourier transformation is useful for spectrum analysis, filtering, transfer function synthesis, and communications.
Fourier Transform Methods Applied To The Analysis Of Microphotometric Images Of Histologic Sections
NASA Astrophysics Data System (ADS)
Dytch, Harvey E.; Wied, George L.
1989-06-01
Implementation of one-dimensional Fourier transform techniques for the analysis of histologic sections is discussed, as is the motivation for their use. Features of the frequency domain representation derived by such a transform are shown to be related to several important diagnostic clues. The interpretation of the Fourier magnitude spectrum in histologically relevant terms is examined by means of Fourier transforms of idealized tissue simulations. Some of the perturbations of these ideal spectra produced by biologic reality are discussed. Three classic types of cervical epithelial tissue are modeled, and their representation as Fourier magnitude spectra interpreted in the light of the previous results: characteristic frequency domain signatures are obtained for each. It is concluded that these techniques may provide diagnostically important objective measures, and may be applied to otherwise intractable histologic specimens with crowded and overlapping nuclei.
Three-dimensional radiative transfer using a Fourier-transform matrix-operator method
NASA Technical Reports Server (NTRS)
Martonchik, J. V.; Diner, D. J.
1985-01-01
The three-dimensional equation of transfer for a scattering medium with planar geometry is solved by using a spatial Fourier transform and extending matrix-operator techniques developed previously for the one-dimensional equation. Doubling and adding algorithms were derived by means of an interaction principle for computing the Fourier-transformed radiation field. The resulting expressions fully describe the radiative transfer process in a scattering medium, inhomogeneous in the x-, y- and z-directions, illuminated from above by an arbitrarily general intensity field and bounded from below by a surface with completely general reflection properties.
NASA Technical Reports Server (NTRS)
Lee, Jonathan A.
2005-01-01
High-throughput measurement techniques are reviewed for solid phase transformation from materials produced by combinatorial methods, which are highly efficient concepts to fabricate large variety of material libraries with different compositional gradients on a single wafer. Combinatorial methods hold high potential for reducing the time and costs associated with the development of new materials, as compared to time-consuming and labor-intensive conventional methods that test large batches of material, one- composition at a time. These high-throughput techniques can be automated to rapidly capture and analyze data, using the entire material library on a single wafer, thereby accelerating the pace of materials discovery and knowledge generation for solid phase transformations. The review covers experimental techniques that are applicable to inorganic materials such as shape memory alloys, graded materials, metal hydrides, ferric materials, semiconductors and industrial alloys.
What Does a Transformative Lens Bring to Credible Evidence in Mixed Methods Evaluations?
ERIC Educational Resources Information Center
Mertens, Donna M.
2013-01-01
Credibility in evaluation is a multifaceted concept that involves consideration of diverse stakeholders' perspectives and purposes. The use of a transformative lens is proposed as a means to bringing issues of social justice and human rights to the foreground in decisions about methodology, credibility of evidence, and use of evaluation…
Several field tests of a Fourier transform infrared (FTIR) spectrometer have been conducted. he results indicate that effective use of this type of instrument in the field of continuous emissions monitoring (CEM) is possible under the proper conditions, and within limits currentl...
ERIC Educational Resources Information Center
Le Patner, Michelle B.
2012-01-01
This study examined the American Recovery and Reinvestment Act federal mandate of the Transformation Intervention Model (TIM) outlined by the School Improvement Grant, which was designed to turn around persistently lowest achieving schools. The study was conducted in four high schools in a large Southern California urban district that selected the…
Apparatus and method for controlling the temperature of the core of a super-conducting transformer
Golner, Thomas; Pleva, Edward; Mehta, Shirish
2006-10-10
An apparatus for controlling the temperature of a core of a transformer is provided that includes a core, a shield surrounding the core, a cast formed between the core and the shield, and tubing positioned on the shield. The cast directs heat from the core to the shield and cooling fluid is directed through the tubing to cool the shield.
Setaria viridis floral-dip: A simple and rapid Agrobacterium-medicated transformation method
Technology Transfer Automated Retrieval System (TEKTRAN)
Setaria viridis was recently described as a new monocotyledonous model species for C4 photosynthesis research and genetic transformation. It has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements) that make it suitable for use as a model plan...
ERIC Educational Resources Information Center
Pearce, Craig L.; Sims, Henry P., Jr.; Cox, Jonathan F.; Ball, Gail; Schnell, Eugene; Smith, Ken A.; Trevino, Linda
2003-01-01
To extend the transactional-transformational model of leadership, four theoretical behavioral types of leadership were developed based on literature review and data from studies of executive behavior (n=253) and subordinate attitudes (n=208). Confirmatory factor analysis of a third data set (n=702) support the existence of four leadership types:…
NASA Astrophysics Data System (ADS)
Jin, Xin; Zhou, Dongming; Yao, Shaowen; Nie, Rencan; Yu, Chuanbo; Ding, Tingting
2016-04-01
In CIELab color space, we propose a remote sensing image fusion technique based on nonsubsampled shearlet transform (NSST) and pulse coupled neural network (PCNN), which aim to improve the efficiency and performance of the remote sensing image fusion by combining the excellent properties of the two methods. First, panchromatic (PAN) and multispectral (MS) are transformed into CIELab color space to get different color components. Second, PAN and L component of MS are decomposed by the NSST to obtain corresponding the low-frequency coefficients and high-frequency coefficients. Third, the low-frequency coefficients are fused by intersecting cortical model (ICM); the high-frequency coefficients are divided into several sub-blocks to calculate the average gradient (AG), and the linking strength β of PCNN model is determined by the AG, so that the parameters β can be adaptively set according to the quality of the sub-block images, then the sub-blocks image are input into PCNN to get the oscillation frequency graph (OFG), the method can get the fused high-frequency coefficients according to the OFG. Finally, the fused L component is obtained by inverse NSST, and the fused RGB color image is obtained through inverse CIELab transform. The experimental results demonstrate that the proposed method provide better effect compared with other common methods.
NASA Astrophysics Data System (ADS)
Hébert, Mathieu
2014-01-01
The well-known Yule-Nielsen modified spectral Neugebauer model is one of the most accurate predictive models for the spectral reflectance of printed halftone colors which expresses the spectral reflectance of halftones raised to the power 1/n as a linear combination of the spectral reflectance of the fulltone colors (Neugebauer primaries) also raised to the power 1/n, where n is a tunable real number. The power 1/n transform, characteristic of the Yule-Nielsen transform, empirically models the nonlinear relationship between the spectral reflectances of halftones and fulltones due to the internal propagation of light by scattering into the printing support, a phenomenon known as "optical dot gain" or "Yule- Nielsen effect". In this paper, we propose a graphical method permitting to observe this non-linear relationship in the case of single-ink halftones and to experimentally check the capacity of the Yule-Nielsen model to predict it accurately. In the case where the Yule-Nielsen transform is not well adapted to the considered type of prints, we propose alternative transforms in order to improve the prediction accuracy.
A transformation method for deriving from a photograph, position and heading of a vehicle in a plane
NASA Technical Reports Server (NTRS)
Sleeper, R. K.; Smith, E. G.
1976-01-01
Equations have been derived that transform perspectively viewed planar surface coordinates, as seen in a photograph, into coordinates of the original plane surface. These transformation equations are developed in terms of nine geometric variables that define the photographic setup and are redefined in terms of eight parameters. The parameters are then treated as independent quantities that fully characterize the transformation and are expressed directly in terms of the four corner coordinates of a reference rectangle in the object plane and their coordinates as seen in a photograph. Vehicle position is determined by transforming the perspectively viewed coordinate position of a representative vehicle target into runway coordinates. Vehicle heading is determined from the runway coordinates of two vehicle target points. When the targets are elevated above the plane of the reference grid, the computation of the heading angle is unaffected; however, the computation of the target position may require adjustment of two parameters. Methods are given for adjusting the parameters for elevation and an example is included for both nonelevated and elevated target conditions.
NASA Astrophysics Data System (ADS)
Dai, Xianglu; Xie, Huimin; Wang, Huaixi; Li, Chuanwei; Liu, Zhanwei; Wu, Lifu
2014-02-01
The geometric phase analysis (GPA) method based on the local high resolution discrete Fourier transform (LHR-DFT) for deformation measurement, defined as LHR-DFT GPA, is proposed to improve the measurement accuracy. In the general GPA method, the fundamental frequency of the image plays a crucial role. However, the fast Fourier transform, which is generally employed in the general GPA method, could make it difficult to locate the fundamental frequency accurately when the fundamental frequency is not located at an integer pixel position in the Fourier spectrum. This study focuses on this issue and presents a LHR-DFT algorithm that can locate the fundamental frequency with sub-pixel precision in a specific frequency region for the GPA method. An error analysis is offered and simulation is conducted to verify the effectiveness of the proposed method; both results show that the LHR-DFT algorithm can accurately locate the fundamental frequency and improve the measurement accuracy of the GPA method. Furthermore, typical tensile and bending tests are carried out and the experimental results verify the effectiveness of the proposed method.
NASA Astrophysics Data System (ADS)
Bang, Jeongho; Yoo, Seokwon
2014-12-01
We propose a genetic-algorithm-based method to find the unitary transformations for any desired quantum computation. We formulate a simple genetic algorithm by introducing the "genetic parameter vector" of the unitary transformations to be found. In the genetic algorithm process, all components of the genetic parameter vectors are supposed to evolve to the solution parameters of the unitary transformations. We apply our method to find the optimal unitary transformations and to generalize the corresponding quantum algorithms for a realistic problem, the one-bit oracle decision problem, or the often-called Deutsch problem. By numerical simulations, we can faithfully find the appropriate unitary transformations to solve the problem by using our method. We analyze the quantum algorithms identified by the found unitary transformations and generalize the variant models of the original Deutsch's algorithm.
Ye, Linlin; Yang, Dan; Wang, Xu
2014-06-01
A de-noising method for electrocardiogram (ECG) based on ensemble empirical mode decomposition (EEMD) and wavelet threshold de-noising theory is proposed in our school. We decomposed noised ECG signals with the proposed method using the EEMD and calculated a series of intrinsic mode functions (IMFs). Then we selected IMFs and reconstructed them to realize the de-noising for ECG. The processed ECG signals were filtered again with wavelet transform using improved threshold function. In the experiments, MIT-BIH ECG database was used for evaluating the performance of the proposed method, contrasting with de-noising method based on EEMD and wavelet transform with improved threshold function alone in parameters of signal to noise ratio (SNR) and mean square error (MSE). The results showed that the ECG waveforms de-noised with the proposed method were smooth and the amplitudes of ECG features did not attenuate. In conclusion, the method discussed in this paper can realize the ECG denoising and meanwhile keep the characteristics of original ECG signal. PMID:25219236
Pendar, Hodjat; Socha, John J
2015-01-01
Flow-through respirometry systems provide accurate measurement of gas exchange over long periods of time. However, these systems have limitations in tracking rapid changes. When an animal infuses a metabolic gas into the respirometry chamber in a short burst, diffusion and airflow in the chamber gradually alter the original signal before it arrives at the gas analyzer. For single or multiple bursts, the recorded signal is smeared or mixed, which may result in dramatically altered recordings compared to the emitted signal. Recovering the original metabolic signal is a difficult task because of the inherent ill conditioning problem. Here, we present two new methods to recover the fast dynamics of metabolic patterns from recorded data. We first re-derive the equations of the well-known Z-transform method (ZT method) to show the source of imprecision in this method. Then, we develop a new model of analysis for respirometry systems based on the experimentally determined impulse response, which is the response of the system to a very short unit input. As a result, we present a major modification of the ZT method (dubbed the 'EZT method') by using a new model for the impulse response, enhancing its precision to recover the true metabolic signals. The second method, the generalized Z-transform (GZT) method, was then developed by generalizing the EZT method; it can be applied to any flow-through respirometry system with any arbitrary impulse response. Experiments verified that the accuracy of recovering the true metabolic signals is significantly improved by the new methods. These new methods can be used more broadly for input estimation in variety of physiological systems. PMID:26466361
Zhao, Guoliang; Li, Hongxing
2013-01-01
This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model. PMID:24453897
Time transformations and Cowell's method. [for numerical integration of satellite motion equations
NASA Technical Reports Server (NTRS)
Velez, C. E.; Hilinski, S.
1978-01-01
The precise numerical integration of Cowell's equations of satellite motion is frequently performed with an independent variable s defined by an equation of the form dt = cr to the n-th power ds, where t represents time, r the radial distance from the center of attraction, c is a constant, and n is a parameter. This has been primarily motivated by the 'uniformizing' effects of such a transformation resulting in desirable 'analytic' stepsize control for elliptical orbits. This report discusses the 'proper' choice of the parameter n defining the independent variable s for various types of orbits and perturbation models, and develops a criterion for its selection.
Auxiliary functions for molecular integrals with Slater-type orbitals. II. Gauss transform methods
NASA Astrophysics Data System (ADS)
Ema, I.; López, R.; Fernández, J. J.; Ramírez, G.; Rico, J. F.
The Gauss transform of Slater-type orbitals is used to express several types of molecular integrals involving these functions in terms of simple auxiliary functions. After reviewing this transform and the way it can be combined with the shift operator technique, a master formula for overlap integrals is derived and used to obtain multipolar moments associated to fragments of two-center distributions and overlaps of derivatives of Slater functions. Moreover, it is proved that integrals involving two-center distributions and irregular harmonics placed at arbitrary points (which determine the electrostatic potential, field and field gradient, as well as higher order derivatives of the potential) can be expressed in terms of auxiliary functions of the same type as those appearing in the overlap. The recurrence relations and series expansions of these functions are thoroughly studied, and algorithms for their calculation are presented. The usefulness and efficiency of this procedure are tested by developing two independent codes: one for the derivatives of the overlap integrals with respect to the centers of the functions, and another for derivatives of the potential (electrostatic field, field gradient, and so forth) at arbitrary points.0
Study of {sup 3}He(e,e{prime}) longitudinal response functions with the integral-transform method
Dobretsov, V.Yu.; Efros, V.D.; Shao, B.
1995-09-01
The method of integral transforms is first applied to study of the {sup 3}He longitudinal response functions. The transforms are calculated from localized bound-state type solutions to an inhomogenous three-body equation. {sup 3}N dynamics and the conventional charge density operator serve as an input. The final-state interaction the contribution of the T = 3/2 final states to the problem suppressed and amounts to about 15%. This might be ascribed to symmetry properties of the final-state wave functions. The contributions of the p-wave N/N interaction and of the Coulomb interaction to the problem are studied and found to amount to several percent. Uncertainties due to different choices of s-wave NN forces are found to be of a similar magnitude. For q = 300 MeV/c, the results obtained agree with experiment. For q = 500 MeV/c, noticeable differences are detected. 20 refs., 3 figs.
NASA Astrophysics Data System (ADS)
Chiba, Ryoichi
2016-02-01
The transient natural convection of a viscous fluid in a heated vertical tube is studied using the two-dimensional differential transform method (DTM). A time-dependent Dirichlet boundary condition is imposed for tube wall temperature. The partial differential equations for the velocity and temperature fields within the tube are solved by the DTM while considering temperature-dependent viscosity and thermal conductivity of the fluid. As a result, tractable solutions in double-series form are derived for the temperature and flow velocity. The transformed functions included in the solutions are obtained through a simple recursive procedure. Numerical results illustrate the effects of temperature-dependent properties on transient temperature and flow behaviour, including the Nusselt number and volumetric flow rate. The DTM gives accurate series solutions without any special functions for nonlinear transient heat transfer problems which are advantageous in finding the derivative or integral.
Pendar, Hodjat; Socha, John J.
2015-01-01
Flow-through respirometry systems provide accurate measurement of gas exchange over long periods of time. However, these systems have limitations in tracking rapid changes. When an animal infuses a metabolic gas into the respirometry chamber in a short burst, diffusion and airflow in the chamber gradually alter the original signal before it arrives at the gas analyzer. For single or multiple bursts, the recorded signal is smeared or mixed, which may result in dramatically altered recordings compared to the emitted signal. Recovering the original metabolic signal is a difficult task because of the inherent ill conditioning problem. Here, we present two new methods to recover the fast dynamics of metabolic patterns from recorded data. We first re-derive the equations of the well-known Z-transform method (ZT method) to show the source of imprecision in this method. Then, we develop a new model of analysis for respirometry systems based on the experimentally determined impulse response, which is the response of the system to a very short unit input. As a result, we present a major modification of the ZT method (dubbed the ‘EZT method’) by using a new model for the impulse response, enhancing its precision to recover the true metabolic signals. The second method, the generalized Z-transform (GZT) method, was then developed by generalizing the EZT method; it can be applied to any flow-through respirometry system with any arbitrary impulse response. Experiments verified that the accuracy of recovering the true metabolic signals is significantly improved by the new methods. These new methods can be used more broadly for input estimation in variety of physiological systems. PMID:26466361
NASA Astrophysics Data System (ADS)
Chia-Hsin Liu, Chelsie; Tsai, Christina W.
2015-04-01
This study introduces a more recent data analysis method, Hilbert Huang transform method (HHT), to analyze transport of sediment particles of a non-stationary and non-linear nature. In order to improve the modeling of the sediment concentrations and bed elevation change, it is proposed to first process the data using the Empirical mode decomposition (EMD) method from HHT to obtain a collection of intrinsic mode functions (IMFs). In this study, an analysis of time series of bed elevations, sediment concentrations, and flow rates is proposed. Multiple time scales exist in the system of flow, sediment transport and bed elevation change processes. With EMD method, we could decompose the original data into several independent intrinsic mode functions (IMF), each of which may be caused by various factors at different time scales. Then, we use HHT to transform every IMF from time-dependent functions into frequency-functions. A case study of the Chou-Shui River in Taiwan is presented. This study will present an alternative for identifying the trend and variability of the bed elevation change, sediment concentration and flow rate. It is hypothesized that the behavior of bed elevation change can be better described at a different time scales using HHT. The lag between the change in flow, sediment concentration and the bed elevation can also be identified in this study. It is expected that the HHT method can provide a viable alternative for an enhanced understanding of sediment transport processes in natural rivers.
On a Chirplet Transform Based Method for Co-channel Voice Separation
NASA Astrophysics Data System (ADS)
Dugnol, B.; Fernández, C.; Galiano, G.; Velasco, J.
We use signal and image theory based algorithms to produce estimations of the number of wolves emitting howls or barks in a given field recording as an individuals counting alternative to the traditional trace collecting methodologies. We proceed in two steps. Firstly, we clean and enhance the signal by using PDE based image processing algorithms applied to the signal spectrogram. Secondly, assuming that the wolves chorus may be modelled as an addition of nonlinear chirps, we use the quadratic energy distribution corresponding to the Chirplet Transform of the signal to produce estimates of the corresponding instantaneous frequencies, chirp-rates and amplitudes at each instant of the recording. We finally establish suitable criteria to decide how such estimates are connected in time.
A Fast Method of Transforming Relaxation Functions Into the Frequency Domain
Mopsik, Frederick I.
1999-01-01
The limits to the error due to truncation of the numeric integration of the one-sided Laplace transform of a relaxation function in the time domain into its equivalent frequency domain are established. Separate results are given for large and small ω. These results show that, for a given ω, only a restricted range of time samples is needed to perform the computation to a given accuracy. These results are then combined with a known error estimate for integration by cubic splines to give a good estimate for the number of points needed to perform the computation to a given accuracy. For a given data window between t1 and t2, the computation time is shown to be proportional to ln(t1/t2).
NASA Technical Reports Server (NTRS)
Wolf, M.
1981-01-01
It is noted that in the case of low-level injection, space-charge quasi-neutrality, and spatially constant material parameters (including an electrostatic field), the individual layer can be treated analytically and the basic solar cell performance parameters can be evaluated from three equations. The first equation represents the transformation of the transport velocity across the layer from the other layer boundary. The second establishes the light-generated current output from the layer interface, under the influence of the transport velocities and minority-carrier density at both layer boundaries and of bulk recombination. The third equation describes the flow of these carriers across other layers. The power of the approach is considered to lie in its facility for analysis of the solar cell's performance layer by layer, giving a clear picture of the individual layer's influence on cell efficiency.
The Fe removal through mineralogical phase transformation of pyrite by physicochemical method
NASA Astrophysics Data System (ADS)
Kim, BongJu; Cho, Kanghee; Jo, JiYu; Bak, GeonYeong; Choi, NagChoul; Park*, Cheonyoung
2015-04-01
Gold is often associated with sulfide minerals (arsenopyrite, pyrite, chalcopyrite, pyrrhotite, galena) as ''invisible'' gold that is thought to consist either of submicrometer metallic particles or to be bound to sulfur in metal sulfide lattice. Pyrite is one of the major minerals accumulating gold in most ores, although a solubility of Au in nonarsenian pyrite is minor, and increased concentrations of gold are associated with arsenic content and iron deficiency. The objective of this study was to investigate the Fe removal through mineralogical phase transformation of pyrite by physical treatment (high frequency) and chemical leaching (ammonia solvent). The high frequency treatment experiment for the pyrite showed that (1) the pyrite phase was transformed pyrrhotite and magnetite, (2) mass loss of the sample by volatilization of included sulfur(S) in pyrite. The treated pyrite by high frequency was observed rim structure from photomicrograph result. Fe removal experiments for were performed under various conditions of high frequency exposure (10~60min), grain size (+140 mesh~-325mesh), sulfuric acid concentration (0.5~3.0M), ammonia sulfate concentration (1.7~6.8M), hydrogen peroxide concentration (0.5~3.0M). Increasing the high frequency exposure produced a positive effect on Fe removal in arsenopyrite. The highest percentage Fe removal of 95.53% was obtained under the following conditions by ammonia solvent: grain size = -325mesh, sulfuric acid concentration = 2.0M, ammonia sulfate concentration = 5.1M, hydrogen peroxide concentration = 1.0M. This subject is supported by Korea Ministry of Environment(MOE) as "Advanced Technology Program for Environmental Industry".
NASA Astrophysics Data System (ADS)
Aprilianto, Mohammada; Abdurohman, Maman
2014-04-01
Text is a media that is often used to convey information in both wired and wireless-based network. One limitation of the wireless system is the network bandwidth. In this study we implemented a text compression application with lossless compression technique using combination of Burrows wheeler transform, move to front, and Huffman coding methods. With the addition of the compression of the text, it is expected to save network resources. This application provides information about compression ratio. From the testing process, it concludes that text compression with only Huffman coding method will be efficient when the number of text characters are above 400 characters, meanwhile text compression with burrows wheeler transform, move to front, and Huffman coding methods will be efficient when the number of text characters are above 531 characters. Combination of these methods are more efficient than just Huffman coding when the number of text characters are above 979 characters. The more characters that are compressed and the more patterns of the same symbol, the better the compression ratio.
A Bridge Health Monitoring Method Using the Hilbert-Huang Transform: A Case Study
NASA Technical Reports Server (NTRS)
Huang, Norden E.; Chiang, Weiling; Busalacchi, Antonio J. (Technical Monitor)
2000-01-01
We have developed a new method for nondestructive instrument method to monitor the health of a bridge. This new method is based on a transient test load and simple data collection. The nuclear of the method is the new invented nonstationary and nonlinear time series analysis method, the Empirical Mode Decomposition and Hilbert Spectral Analysis. The final decision on the health of the bridge structure is based on the nonlinear characteristic of the data, and on the comparison between the free and the forced vibration frequencies. Thus this alternative method enjoys many advantages: (1) no a priori data required, (2) simple data collection, and (3) minimum traffic disruption. Results from a case study of the Shing-Nan Bridge in Hou-Wei will be reported.
Method for transforming CT images for attenuation correction in PET/CT imaging
Carney, Jonathan P.J.; Townsend, David W.; Rappoport, Vitaliy; Bendriem, Bernard
2006-04-15
A tube-voltage-dependent scheme is presented for transforming Hounsfield units (HU) measured by different computed tomography (CT) scanners at different x-ray tube voltages (kVp) to 511 keV linear attenuation values for attenuation correction in positron emission tomography (PET) data reconstruction. A Gammex 467 electron density CT phantom was imaged using a Siemens Sensation 16-slice CT, a Siemens Emotion 6-slice CT, a GE Lightspeed 16-slice CT, a Hitachi CXR 4-slice CT, and a Toshiba Aquilion 16-slice CT at kVp ranging from 80 to 140 kVp. All of these CT scanners are also available in combination with a PET scanner as a PET/CT tomograph. HU obtained for various reference tissue substitutes in the phantom were compared with the known linear attenuation values at 511 keV. The transformation, appropriate for lung, soft tissue, and bone, yields the function 9.6x10{sup -5}{center_dot}(HU+1000) below a threshold of {approx}50 HU and a{center_dot}(HU+1000)+b above the threshold, where a and b are fixed parameters that depend on the kVp setting. The use of the kVp-dependent scaling procedure leads to a significant improvement in reconstructed PET activity levels in phantom measurements, resolving errors of almost 40% otherwise seen for the case of dense bone phantoms at 80 kVp. Results are also presented for patient studies involving multiple CT scans at different kVp settings, which should all lead to the same 511 keV linear attenuation values. A linear fit to values obtained from 140 kVp CT images using the kVp-dependent scaling plotted as a function of the corresponding values obtained from 80 kVp CT images yielded y=1.003x-0.001 with an R{sup 2} value of 0.999, indicating that the same values are obtained to a high degree of accuracy.
ERIC Educational Resources Information Center
Anderson, Rosemarie; Braud, William
2011-01-01
Research approaches in the field of transpersonal psychology can be transformative for researchers, participants, and the audience of a project. This book offers these transformative approaches to those conducting research across the human sciences and the humanities. Rosemarie Anderson and William Braud first described such methods in…
NASA Astrophysics Data System (ADS)
Studenikin, S. A.; Golego, Nickolay; Cocivera, Michael
1998-11-01
Slow relaxation of the photoconductivity over a period of days was studied in polycrystalline ZnO and TiO2 films prepared by spray pyrolysis. The phenomenon is described by a model involving deep sensitizing hole traps in the forbidden gap. The trap state distribution based on this model was calculated using an improved Laplace transform method. For ZnO and TiO2 films, the density of states was shown to have a peak-like distribution with a maximum near the lower third of the energy gap.
Sheu, Yae-lin; Hsu, Liang-Yan; Wu, Hau-tieng; Li, Peng-Cheng; Chu, Shih-I
2014-11-15
This study introduces a new adaptive time-frequency (TF) analysis technique, the synchrosqueezing transform (SST), to explore the dynamics of a laser-driven hydrogen atom at an ab initio level, upon which we have demonstrated its versatility as a new viable venue for further exploring quantum dynamics. For a signal composed of oscillatory components which can be characterized by instantaneous frequency, the SST enables rendering the decomposed signal based on the phase information inherited in the linear TF representation with mathematical support. Compared with the classical type of TF methods, the SST clearly depicts several intrinsic quantum dynamical processes such as selection rules, AC Stark effects, and high harmonic generation.
Aota, Arata; Date, Yasumoto; Terakado, Shingo; Ohmura, Naoya
2013-01-01
Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are present in the insulating oil inside a large number of transformers. To aid in eliminating PCB-contaminated transformers, PCBs in oil need to be measured using a rapid and cost-effective analytical method. We previously reported a pretreatment method for the immunoassay of PCBs in oil using a large-scale multilayer column and a microchip with multiple microrecesses, which permitted concentrated solvent extraction. In this paper, we report on a more rapid and facile pretreatment method, without an evaporation process, by improving the column and the microchip. In a miniaturized column, the decomposition and separation of oil were completed in 2 min. PCBs can be eluted from the capillary column at concentrations seven-times higher than those from the previous column. The total volume of the microrecesses was increased by improving the microrecess structure, the enabling extraction of four-times the amount of PCBs achieved with the previous system. By interfacing the capillary column with the improved microchip, PCBs in the eluate from the column were extracted into dimethyl sulfoxide in microrecesses with high enrichment and without the need for evaporation. Pretreatment was completed within 20 min. The pretreated oil was analyzed using a flow-based kinetic exclusion immunoassay. The limit of detection of PCBs in oil was 0.15 mg kg(-1), which satisfies the criterion set in Japan of 0.5 mg kg(-1). PMID:23574664
NASA Astrophysics Data System (ADS)
Zarkevich, Nikolai; Johnson, Duane D.
Titanium is on of the four most utilized structural metals, and, hence, its structural changes and potential metastable phases under stress are of considerable importance. Using DFT+U combined with the generalized solid-state nudged elastic band (SS-NEB) method, we consider the pressure-driven transformation between Ti α and ω phases, and find an intermediate metastable body-centered orthorhombic (bco) structure of lower density. We verify its stability, assess the phonons and electronic structure, and compare computational results to experiment. Interestingly, standard density functional theory (DFT) yields the ω phase as the Ti ground state, in contradiction to the observed α phase at low pressure and temperature. We correct this by proper consideration of the strongly correlated d-electrons, and utilize DFT+U method in the SS-NEB to obtain the relevant transformation pathway and structures. We use methods developed with support by the U.S. Department of Energy (DE-FG02-03ER46026 and DE-AC02-07CH11358). Ames Laboratory is operated for the DOE by Iowa State University under Contract DE-AC02-07CH11358.
NASA Astrophysics Data System (ADS)
Prayuni, Kinasih; Dwivany, Fenny M.
2015-09-01
Banana is classified as a climateric fruit, whose ripening is regulated by ethylene. Ethylene is synthesized from ACC (1-aminocyclopropane-1-carboxylic acid) by ACC oxidase enzyme which is encoded by ACO gene. Controling an important gene expression in ethylene biosynthesis pathway has became a target to delay the ripening process. Therefore in the previous study we have designed a MaACO-RNAi construct to control MaACO gene expression. In this research, we study the effectiveness of different transient transformation methods to deliver the construct. Direct injection, with or no vaccum infiltration methods were used to deliver MaACO-RNAi construct. All of the methods succesfully deliver the construct into banana fruits based on RT-PCR result.
Kozlov, Denis; Besov, Alexey
2011-08-01
A new method of spectral subtraction for gas-phase Fourier transform infrared (FT-IR) spectra was developed for long-path gas measurements. The method is based on minimization of the length of the spectrum that results from subtracting the spectrum of an individual component of a gas mixture (water, CO(2), etc.) from the experimental spectrum of the mixture. For this purpose a subtraction coefficient (k(min)) is found for which the length of the resulting spectrum is minimized. A mathematical simulation with two Lorentzian absorption bands was conducted and the limits of application for the proposed method were determined. Two experimental examples demonstrate that a successful result could be achieved in the case when the subtrahend spectrum contains a number of narrow absorption bands (such as the spectrum of water vapor). PMID:21819781
Patel, Trushit; Meher, Ramakanta
2016-01-01
In this paper, Adomian decomposition sumudu transform method is introduced and used to solve the temperature distribution in a solid and porous fin with the temperature dependent internal heat generation for a fractional order energy balance equation. In this study, we assume heat generation as a variable of fin temperature for solid and porous fin and the heat transfer through porous media is simulated by using Darcy's model. The results are presented for the temperature distribution for the range of values of parameters appeared in the mathematical formulation and also compared with numerical solutions in order to verify the accuracy of the proposed method. It is found that the proposed method is in good agreement with direct numerical solution. PMID:27218004
Cebi, Nur; Durak, M Zeki; Toker, Omer Said; Sagdic, Osman; Arici, Muhammet
2016-01-01
The objective of this research was to develop a rapid spectroscopic technique as an alternative method for the differentiation and authentication of gelatin sources in food products by using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra combined with chemometrics. Clear discrimination and classification of all the studied gelatin sources (bovine, porcine, and fish) were achieved by hierarchical cluster and principle component analysis (PCA). Amide-I (1700-1600 cm(-1)) and Amide-II (1565-1520 cm(-1)) spectral bands were used in a chemometric method. Moreover, ATR-FTIR spectral data successfully discriminated pure bovine gelatin from mixture of bovine and porcine gelatins, which is very important for the food industry. The method that we adopted could be beneficial for rapid, simple and economic determination of both gelatin presence and its origin from food products such as yogurt, ice cream, milk dessert or other gelatin containing products such as pharmaceuticals and cosmetics. PMID:26213083
The method of unitary clothing transformations in the theory of nucleon-nucleon scattering
NASA Astrophysics Data System (ADS)
Dubovyk, I.; Shebeko, A.
2010-04-01
The clothing procedure, put forward in quantum field theory (QFT) by Greenberg and Schweber, is applied for the description of nucleon-nucleon (N -N) scattering. We consider pseudoscalar (π and η), vector (ρ and ω) and scalar (δ and σ) meson fields interacting with 1/2 spin (N and N) fermion ones via the Yukawa-type couplings to introduce trial interactions between “bare” particles. The subsequent unitary clothing transformations (UCTs) are found to express the total Hamiltonian through new interaction operators that refer to particles with physical (observable) properties, the so-called clothed particles. In this work, we are focused upon the Hermitian and energy-independent operators for the clothed nucleons, being built up in the second order in the coupling constants. The corresponding analytic expressions in momentum space are compared with the separate meson contributions to the one-boson-exchange potentials in the meson theory of nuclear forces. In order to evaluate the T matrix of the N-N scattering we have used an equivalence theorem that enables us to operate in the clothed particle representation (CPR) instead of the bare particle representation (BPR) with its huge amount of virtual processes. We have derived the Lippmann-Schwinger(LS)-type equation for the CPR elements of the T-matrix for a given collision energy in the two-nucleon sector of the Hilbert space H of hadronic states and elaborated a code for its numerical solution in momentum space.
The Method of Unitary Clothing Transformations in the Theory of Nucleon-Nucleon Scattering
NASA Astrophysics Data System (ADS)
Dubovyk, I.; Shebeko, O.
2010-12-01
The clothing procedure, put forward in quantum field theory (QFT) by Greenberg and Schweber, is applied for the description of nucleon-nucleon ( N- N) scattering. We consider pseudoscalar ( π and η), vector ( ρ and ω) and scalar ( δ and σ) meson fields interacting with 1/2 spin ( N and {bar{N}}) fermion ones via the Yukawa-type couplings to introduce trial interactions between “bare” particles. The subsequent unitary clothing transformations are found to express the total Hamiltonian through new interaction operators that refer to particles with physical (observable) properties, the so-called clothed particles. In this work, we are focused upon the Hermitian and energy-independent operators for the clothed nucleons, being built up in the second order in the coupling constants. The corresponding analytic expressions in momentum space are compared with the separate meson contributions to the one-boson-exchange potentials in the meson theory of nuclear forces. In order to evaluate the T matrix of the N- N scattering we have used an equivalence theorem that enables us to operate in the clothed particle representation (CPR) instead of the bare particle representation with its large amount of virtual processes. We have derived the Lippmann-Schwinger type equation for the CPR elements of the T-matrix for a given collision energy in the two-nucleon sector of the Hilbert space {mathcal{H}} of hadronic states.
NASA Astrophysics Data System (ADS)
Hernández-Tenorio, C.; Serkin, V. N.; Belyaeva, T. L.; Peña-Moreno, R.; Morales-Lara, L.
2015-01-01
The nonlinear Schrödinger equation (NLSE) model with an external harmonic potential is one of the most important in modern science. This model makes it possible to analyze a variety of nonlinear phenomena, in nonlinear optics and laser physics, biophysics and in the theory of Bose-Einstein condensation of atoms. It is shown that the main specific feature of the dynamics of dark GP matter wave solitons in a parabolic trap is the formation of solitons with dynamically changing form-factors producing the periodic variation in the modulation depth (the degree of "blackness") of dark solitons. In general, the period of dark soliton oscillations in trapping potential depends on the specific conditions of the experiment and does not coincide with the oscillation period of a linear quantum-mechanical oscillator. In the case of an immobile pedestal in the trap, the oscillation period of the black soliton considerably increases because of the periodic transformation of the black soliton to the gray one and vice versa. Surprisingly, that if the dark soliton is superimposed on the base pedestal oscillating in the trap and displaced from the trap center, the oscillation period of the dark soliton coincides with the period of oscillations of the linear harmonic oscillator, while the dynamics of the dark soliton is similar to that of a classical particle obeying the Newton mechanics laws.
A simple method to fabricate lenses for in situ Fourier transform infrared spectroscopy
NASA Astrophysics Data System (ADS)
Treffman, Lia M.; Morrison, Philip W., Jr.
1996-04-01
A process has been developed to hand grind and polish infrared KBr lenses with a wide choice of focal lengths. These lenses are designed for coupling the infrared (IR) beam from a Fourier transform infrared spectrometer into a hot filament chemical vapor deposition reactor. These IR lenses are ground using a glass lens as a mold; the mold lens is a commercial glass lens used for spectacles and is available in a wide range of focal lengths. Rough grinding begins with ♯100 sandpaper and followed by a sequence of fine grinding steps under ethanol: ♯400 SiC powder, ♯600 SiC powder, and emery powder. Polishing is done with a CeO slurry in water followed by a chamois cloth moistened with ethanol. As an indication of the surface finish of the lenses, a flat KBr window that is hand ground and polished in the above manner has a transmission of ≳89% at 8000 cm-1 and ≳91% at 500 cm-1; the commercially polished KBr window has a transmittance of 92% throughout this spectral range.
Mousavi, Seyed Mortaza; Adamoğlu, Ahmet; Demiralp, Tamer; Shayesteh, Mahrokh G.
2014-01-01
Awareness during general anesthesia for its serious psychological effects on patients and some juristically problems for anesthetists has been an important challenge during past decades. Monitoring depth of anesthesia is a fundamental solution to this problem. The induction of anesthesia alters frequency and mean of amplitudes of the electroencephalogram (EEG), and its phase couplings. We analyzed EEG changes for phase coupling between delta and alpha subbands using a new algorithm for depth of general anesthesia measurement based on complex wavelet transform (CWT) in patients anesthetized by Propofol. Entropy and histogram of modulated signals were calculated by taking bispectral index (BIS) values as reference. Entropies corresponding to different BIS intervals using Mann-Whitney U test showed that they had different continuous distributions. The results demonstrated that there is a phase coupling between 3 and 4 Hz in delta and 8-9 Hz in alpha subbands and these changes are shown better at the channel T7 of EEG. Moreover, when BIS values increase, the entropy value of modulated signal also increases and vice versa. In addition, measuring phase coupling between delta and alpha subbands of EEG signals through continuous CWT analysis reveals the depth of anesthesia level. As a result, awareness during anesthesia can be prevented. PMID:25276220
NASA Astrophysics Data System (ADS)
Rodríguez-Lorenzo, F.; Dorrío, B. V.; Blanco, J.
2012-09-01
The knowledge of the flow structure of fluids is essential in many industrial sectors as it determines the quality and success of processes like welding, cutting or material treatment. The employed fluid flow plays a fundamental role and in all cases to understand the complex pressure and shock waves patterns becomes necessary. The only way to absolutely ensure that the theoretical behavior predicted by numerical simulations fits with the real gas flow behavior is the experimental check. For such application, the optical techniques are very well suited resources due to their non invasive features. Schlieren, shadowgraph and interferometry are the typical techniques used for the study of the mass flow in fluids. In this work, we present the qualitative results obtained from a conventional interferometric technique combined with a new numerical approach used for analyzing the inner structure of supersonic flows provided by nozzles with Laval profile used in industrial oxy-fuel cutting processes. The extraction of the optical phase from the fringe patterns is performed through a Differential Fourier Transform Evaluation. We show that with further numerical processing we can obtain a complete qualitative description of the flow field including the first and second optical phase derivatives (Gradient and Lapacian phase maps).
Targeted biolistics for improved transformation of Impatiens balsamina.
Wetten, Andy C; Thomas, Jean-Luc; Wagiran, Alina; Chiurugwi, Tinashe
2012-01-01
A transgenesis programme has been developed for Impatiens balsamina that will allow elucidation of the roles played by individual genes in the flower reversion phenomenon shown by this model species. The lack of explants exhibiting adventitious shooting in I. balsamina hinders Agrobacterium-based transformation, but the multiple shoots that arise from cotyledonary nodes present a suitable target for biolistics. These tissues can be disrupted by the helium blast effect associated with conventional biolistic devices, so we have utilised modifications to the PDS 1000/He equipment originally developed for transformation of fragile insect tissues. By loading microcarriers on to a rigid, rather than flexible, macrocarrier, the blast effect is largely eliminated, and the use of a focussing nozzle allows the bombardment to be concentrated on the target tissues. This approach reduces waste of plasmid DNA and gold microcarriers and achieves transfection at lower, less disruptive helium pressures than would otherwise be necessary to efficiently penetrate below the shoot epidermis and generate heritable transgenic lines. PMID:22351015
Moriguchi, Kazuki; Yamamoto, Shinji; Ohmine, Yuta; Suzuki, Katsunori
2016-01-01
Trans-kingdom conjugation is a phenomenon by which DNA is transferred into a eukaryotic cell by a bacterial conjugal transfer system. Improvement in this method to facilitate the rapid co-cultivation of donor bacterial and recipient eukaryotic cell cultures could make it the simplest transformation method, requiring neither isolation of vector DNA nor preparation of competent recipient cells. To evaluate this potential advantage of trans-kingdom conjugation, we examined this simple transformation method using vector combinations, helper plasmids, and recipient Saccharomyces cerevisiae strains. Mixing donor Escherichia coli and recipient S. cerevisiae overnight cultures (50 μL each) consistently yielded on the order of 101 transformants using the popular experimental strain BY4742 derived from S288c and a shuttle vector for trans-kingdom conjugation. Transformation efficiency increased to the order of 102 using a high receptivity trans-kingdom conjugation strain. In addition, either increasing the amount of donor cells or pretreating the recipient cells with thiols such as dithiothreitol improved the transformation efficiency by one order of magnitude. This simple trans-kingdom conjugation-mediated transformation method could be used as a practical yeast transformation method upon enrichment of available vectors and donor E. coli strains. PMID:26849654
NASA Astrophysics Data System (ADS)
Muzy, J. F.; Bacry, E.; Arneodo, A.
1993-02-01
Several attempts have been made recently to generalize the multifractal formalism, originally introduced for singular measures, to fractal signals. We report on a systematic comparison between the structure-function approach, pioneered by Parisi and Frisch [in 2 Proceedings of the International School on Turbulence and Predictability in Geophysical Fluid Dynamics and Climate Dynamics, edited by M. Ghil, R. Benzi, and G. Parisi (North-Holland, Amsterdam, 1985), p. 84] to account for the multifractal nature of fully developed turbulent signals, and an alternative method we have developed within the framework of the wavelet-transform analysis. We comment on the intrinsic limitations of the structure-function approach; this technique has fundamental drawbacks and does not provide a full characterization of the singularities of a signal in many cases. We demonstrate that our method, based on the wavelet-transform modulus-maxima representation, works in most situations and is likely to be the ground of a unified multifractal description of self-affine distributions. Our theoretical considerations are both illustrated on pedagogical examples and supported by numerical simulations.
Cuevas, Erik; Díaz, Margarita
2015-01-01
In this paper, a new method for robustly estimating multiple view relations from point correspondences is presented. The approach combines the popular random sampling consensus (RANSAC) algorithm and the evolutionary method harmony search (HS). With this combination, the proposed method adopts a different sampling strategy than RANSAC to generate putative solutions. Under the new mechanism, at each iteration, new candidate solutions are built taking into account the quality of the models generated by previous candidate solutions, rather than purely random as it is the case of RANSAC. The rules for the generation of candidate solutions (samples) are motivated by the improvisation process that occurs when a musician searches for a better state of harmony. As a result, the proposed approach can substantially reduce the number of iterations still preserving the robust capabilities of RANSAC. The method is generic and its use is illustrated by the estimation of homographies, considering synthetic and real images. Additionally, in order to demonstrate the performance of the proposed approach within a real engineering application, it is employed to solve the problem of position estimation in a humanoid robot. Experimental results validate the efficiency of the proposed method in terms of accuracy, speed, and robustness. PMID:26339228
Cuevas, Erik; Díaz, Margarita
2015-01-01
In this paper, a new method for robustly estimating multiple view relations from point correspondences is presented. The approach combines the popular random sampling consensus (RANSAC) algorithm and the evolutionary method harmony search (HS). With this combination, the proposed method adopts a different sampling strategy than RANSAC to generate putative solutions. Under the new mechanism, at each iteration, new candidate solutions are built taking into account the quality of the models generated by previous candidate solutions, rather than purely random as it is the case of RANSAC. The rules for the generation of candidate solutions (samples) are motivated by the improvisation process that occurs when a musician searches for a better state of harmony. As a result, the proposed approach can substantially reduce the number of iterations still preserving the robust capabilities of RANSAC. The method is generic and its use is illustrated by the estimation of homographies, considering synthetic and real images. Additionally, in order to demonstrate the performance of the proposed approach within a real engineering application, it is employed to solve the problem of position estimation in a humanoid robot. Experimental results validate the efficiency of the proposed method in terms of accuracy, speed, and robustness. PMID:26339228
A Novel Ship-rocking Forecasting Method based on Hilbert- Huang Transform
NASA Astrophysics Data System (ADS)
De-yong, Kang; Yu-jian, Li; Xu-liang, Wang; Zhi, Chen
2016-02-01
The ship-rocking is a crucial factor which affects the accuracy of the ocean-based aerospace vehicle measurement. Here we have analysed groups of ship-rocking time series in horizontal and vertical directions utilizing a Hilbert based method from statistical physics. Based on these results we could predict certain amount of future values of the ship-rocking time series based on the current and the previous values. Our predictions are as accurate as the conventional methods from stochastic processes and provide a much wider prediction time range.
Recursion-Transform method to a non-regular m × n cobweb with an arbitrary longitude.
Tan, Zhi-Zhong
2015-01-01
A general Recursion-Transform method is put forward and is applied to resolving a difficult problem of the two-point resistance in a non-regular m × n cobweb network with an arbitrary longitude (or call radial), which has never been solved before as the Green's function technique and the Laplacian matrix approach are difficult in this case. Looking for the explicit solutions of non-regular lattices is important but difficult, since the non-regular condition is like a wall or trap which affects the behavior of finite network. This paper gives several general formulae of the resistance between any two nodes in a non-regular cobweb network in both finite and infinite cases by the R-T method which, is mainly composed of the characteristic roots, is simpler and can be easier to use in practice. As applications, several interesting results are deduced from a general formula, and a globe network is generalized. PMID:26073882
NASA Astrophysics Data System (ADS)
Nakazawa, Susumu; Tanaka, Shoji; Shogen, Kazuyoshi
Satellite broadcasting in the 21-GHz band is expected to transmit large-capacity signals such as ultrahigh-definition TV. However, this band suffers from large amounts of rain attenuation. In this regard, we have been studying rain fading mitigation techniques, in which the radiation power is increased locally in the area of heavy rainfall. To design such a satellite broadcasting system, it is necessary to evaluate service availability when using the locally increased beam technique. The rain attenuation data should be derived from the rainfall rate data. We developed a method to transform rainfall rate into rain attenuation in the 21GHz band. Then, we performed a simulation that applied the method to the analysis of the service availability for an example phased array antenna configuration. The results confirmed the service availability increased with the locally increased beam technique.
ERIC Educational Resources Information Center
Angeli, Charoula
2005-01-01
In this study, an instructional design model was employed for restructuring a teacher education course with technology. The model was applied in a science education method course, which was offered in two different but consecutive semesters with a total enrollment of 111 students in the fall semester and 116 students in the spring semester. Using…
Technology Transfer Automated Retrieval System (TEKTRAN)
Most efforts to harness the power of big data for ecology and environmental sciences focus on data and metadata sharing, standardization, and accuracy. However, many scientists have not accepted the data deluge as an integral part of their research because the current scientific method is not scalab...
ERIC Educational Resources Information Center
He, Yong
2013-01-01
Common test items play an important role in equating multiple test forms under the common-item nonequivalent groups design. Inconsistent item parameter estimates among common items can lead to large bias in equated scores for IRT true score equating. Current methods extensively focus on detection and elimination of outlying common items, which…
Hidaka, S; Abe, K; Liu, S Y
1991-01-01
A simple method of assaying the formation of amorphous calcium phosphate and its transformation to hydroxyapatite using a conventional pH meter and recorder is described. Its validity was confirmed by direct assay of calcium consumption with atomic absorption spectrophotometry. The method was used to study substances which influence the formation of amorphous calcium phosphate and its transformation to hydroxyapatite, such as albumin, casein, chondroitin sulphate, phospholipid, ATP, Mg2+, Sr2+, pyrophosphate and several Chinese folk medicines. PMID:1849399
Osipovich, Nikolai P; Poznyak, Sergei K; Lesnyak, Vladimir; Gaponik, Nikolai
2016-04-21
The application of electrochemical methods for the characterization of colloidal quantum dots (QDs) attracts considerable attention as these methods may allow for monitoring of some crucial parameters, such as energetic levels of conduction and valence bands as well as surface traps and ligands under real conditions of colloidal solution. In the present work we extend the applications of cyclic voltammetry (CV) to in situ monitoring of degradation processes of water-soluble CdTe QDs. This degradation occurs under lowering of pH to the values around 5, i.e. under conditions relevant to bioimaging applications of these QDs, and is accompanied by pronounced changes of their photoluminescence. Observed correlations between characteristic features of CV diagrams and the fluorescence spectra allowed us to propose mechanisms responsible for evolution of the photoluminescence properties as well as degradation pathway of CdTe QDs at low pH. PMID:27025663
An implicit fast Fourier transform method for integration of the time dependent Schrodinger equation
Riley, M.E.; Ritchie, A.B.
1997-12-31
One finds that the conventional exponentiated split operator procedure is subject to difficulties when solving the time-dependent Schrodinger equation for Coulombic systems. By rearranging the kinetic and potential energy terms in the temporal propagator of the finite difference equations, one can find a propagation algorithm for three dimensions that looks much like the Crank-Nicholson and alternating direction implicit methods for one- and two-space-dimensional partial differential equations. The authors report investigations of this novel implicit split operator procedure. The results look promising for a purely numerical approach to certain electron quantum mechanical problems. A charge exchange calculation is presented as an example of the power of the method.
NASA Astrophysics Data System (ADS)
Vella, K.; Kurata, N.; Soloviev, A.; Matt, S.; Shivji, M.; Tartar, A.
2012-12-01
The sea surface microlayer represents the interface between the atmosphere and the ocean and it can serve as a collection point for organic materials, such as surfactants. In this work, we present an improved method for the identification of the microbial community structure present in both the sea surface microlayer and the corresponding water column, in relation to surfactant production/transformation. Bacterial samples were collected from the sea surface microlayer with an improved sampling method, which minimized sample contamination from the research platform and the subsurface water. This novel sampling approach was developed by using polycarbonate membrane filters attached to fly fishing line, which provided finer control of the filter touching only the sea surface. Sampling was conducted at open ocean (approximately five miles offshore) and coastal water sites (approximately one mile from coastline) in the Straits of Florida to compare surfactant-producing bacterial populations present in these two regions. The microlayer sampling was planned to coincide with synthetic aperture radar (SAR) satellite overpasses (COSMO SkyMed). By establishing bacterial groups that influence the presence of surfactants, remote sensing techniques which involve monitoring the surface of the ocean will be enhanced. This is because surfactants are capable of suppressing short gravity-capillary ocean surface waves, which affect radar back-scatter. SAR remote sensing thus may provide additional information on the state of the upper ocean ecosystem. Microbial composition was determined using DNA analysis of 16S rRNA genes. Preliminary analysis of bay samples suggested the presence of bacteria related to a strain of uncultured gammaproteobacteria, previously isolated from coastal sediment along a hydrocarbon contamination gradient. Many genera of the gammaproteobacteria are known to be involved in hydrocarbon degradation. We are further exploring and quantifying the presence of
Zhao, Yanli; Zhang, Ji; Jin, Hang; Zhang, Jinyu; Shen, Tao; Wang, Yuanzhong
2015-01-01
Gentiana rigescens ("Dian Longdan" in Chinese) medicinal plant is usually used for its activities of liver protection, cholagogic, anti-inflammatory, anti-fungal, anti-hyperthyroidism, anti-hypertension, hyperglycemia, and relieving spasm and pain. In this study, methods for the discrimination of different geographical origins of G. rigescens by FTIR spectroscopy in hyphenation with chemometric methods were developed. Different pretreatments including standard normal variate, multiplicative scatter correction, first or second derivative, Savitzky-Golay filter, and Norris derivative filter were applied on the spectra to optimize the calibrations. According to spectrum SD, spectrum ranges (3559-2709 and 2026-756 cm(-1)) were selected, and principal component analysis-Mahalanobis distance (PCA-MD) model was built [the cumulative contribution rate of the first 10 principal components, determination coefficient (R2), root-mean-square error of calibration (RMSEC), and root-mean-square error of prediction (RMSEP), and prediction accuracy were 96.4%, 98.6%, 0.5031, 0.7758, and 96.23%, respectively]. The spectral regions (3791-3442, 3043-2765, and 2013-646 cm(-1)) were selected by using the variable importance in projection, and partial least squares discriminant analysis (PLS-DA) model was built (the cumulative contribution rate of the first 10 principal components, R2, RMSEC, RMSEP, and prediction accuracy were 91.3%, 92.0%, 0.1171, 0.1806, and 100%, respectively). This research showed that FTIR spectroscopy in combination with chemometrics methods (PCA-MD and PLS-DA) was suitable for the discrimination of different geographical origins of G. rigescens. Furthermore, it was found that PLS-DA provided better results than PCA-MD. PMID:25857874
Maury, Augusto; Revilla, Reynier I
2015-08-01
Cosmic rays (CRs) occasionally affect charge-coupled device (CCD) detectors, introducing large spikes with very narrow bandwidth in the spectrum. These CR features can distort the chemical information expressed by the spectra. Consequently, we propose here an algorithm to identify and remove significant spikes in a single Raman spectrum. An autocorrelation analysis is first carried out to accentuate the CRs feature as outliers. Subsequently, with an adequate selection of the threshold, a discrete wavelet transform filter is used to identify CR spikes. Identified data points are then replaced by interpolated values using the weighted-average interpolation technique. This approach only modifies the data in a close vicinity of the CRs. Additionally, robust wavelet transform parameters are proposed (a desirable property for automation) after optimizing them with the application of the method in a great number of spectra. However, this algorithm, as well as all the single-spectrum analysis procedures, is limited to the cases in which CRs have much narrower bandwidth than the Raman bands. This might not be the case when low-resolution Raman instruments are used. PMID:26163458
Temperature dependent shape transformation of Ge nanostructures by the vapor-liquid-solid method
NASA Astrophysics Data System (ADS)
Das, K.; Chakraborty, A. K.; NandaGoswami, M. L.; Shingha, R. K.; Dhar, A.; Coleman, K. S.; Ray, S. K.
2007-04-01
A vapor-liquid-solid method has been used to study the temperature dependent growth mechanism of Ge nanostructures on Au-coated Si (100) substrates. The formation of Ge nanodots, nanorods, and nanowires has been observed at different growth temperatures. The diameter of grown nanowires is found to be varying from 40 to 80 nm and that of nanorods from 70 to 90 nm, respectively. A comparative study has been done on three types of samples using x-ray diffraction and Raman spectroscopy. Photoluminescence spectra of grown nanostructures exhibit a broad emission band around 2.6 eV due to oxide related defect states.
A comparison of feature extraction methods for Sentinel-1 images: Gabor and Weber transforms
NASA Astrophysics Data System (ADS)
Stan, Mihaela; Popescu, Anca; Stoichescu, Dan Alexandru
2015-10-01
The purpose of this paper is to compare the performance of two feature extraction methods when applied on high resolution Synthetic Aperture Radar (SAR) images acquired with the new ESA mission SENTINEL-1 (S-1). The feature extraction methods were previously tested on high and very high resolution SAR data (imaged by TerraSAR-X) and had a good performance in discriminating between a relevant numbers of land cover classes (tens of classes). Based on the available spatial resolution (10x10m) of S-1 Interferometric Wide (IW) Ground Range Detected (GRD) images the number of detectable classes is much lower. Moreover, the overall heterogeneity of the images is much lower as compared to the high resolution data, the number of observable details is smaller, and this favors the choice of a smaller window size for the analysis: between 10 and 50 pixels in range and azimuth. The size of the analysis window ensures the consistency with the previous results reported in the literature in very high resolution data (as the size on the ground is comparable and thus the number of contributing objects in the window is similar). The performance of Gabor filters and the Weber Local Descriptor (WLD) was investigated in a twofold approach: first the descriptors were computed directly over the IW GRD images and secondly on the sub-sampled version of the same data (in order to determine the effect of the speckle correlation on the overall class detection probability).
Reaugh, J E; Lee, E L
2002-07-01
Mixture rules for partially reacted explosives differ amongst various models. For instance, JWL++ uses a partial pressure addition to compute an average zonal pressure, Ignition and Growth requires pressure equilibration and thermal equilibration of temperature dependent JWL EOSs, CHEETAH In Line RF also assumes temperature and pressure equilibration. It has been suggested in the past that a more realistic equilibration scheme should comprise isentropic pressure equilibration of the separate reacted and unreacted phases. This turns out not to be a proper path for equilibration. Rather, we find that the only internally consistent method is the evaluation of the equilibrium pressure that satisfies the particular conditions of reactant and product resulting from deflagration in a fixed volume.
Ruíz, A; Ayora Cañada, M J; Lendl, B
2001-02-01
The development of an automated, rapid and highly precise method for determination of the peroxide value in edible oils based on a continuous flow system and Fourier transform infrared (FTIR) spectroscopic detection is described. The sample stream was mixed with a solvent mixture consisting of 25% (v/v) toluene in hexanol which contained triphenylphosphine (TPP). The hydroperoxides present in the sample reacted stoichiometrically with TPP to give triphenylphosphine oxide (TPPO) which has a characteristic and intense absorption band at 542 cm-1. A 10% (m/v) TPP solution in the solvent mixture and a 100 cm reaction coil were necessary for complete reaction. FTIR transmission spectra were recorded using a flow cell equipped with CsI windows having an optical pathlength of 100 microns. By using tert-butyl hydroperoxide spiked oil standards and evaluation of the band formed at 542 cm-1 a linear calibration graph covering the range 1-100 PV (peroxide value; mequiv O2 kg-1 oil) was obtained. The relative standard deviation was 0.23% (n = 11) and the throughput 24 samples h-1. The developed system was also applied to the determination of PV in olive, sunflower and corn oils, showing good agreement with the official reference method of the European Community which is based on titration using organic solvents. The results obtained clearly show that the developed method is superior to the standard wet chemical method, hence suggesting its application in routine analysis and quality control. PMID:11235111
Schrottke, L. Lü, X.; Grahn, H. T.
2015-04-21
We present a self-consistent model for carrier transport in periodic semiconductor heterostructures completely formulated in the Fourier domain. In addition to the Hamiltonian for the layer system, all expressions for the scattering rates, the applied electric field, and the carrier distribution are treated in reciprocal space. In particular, for slowly converging cases of the self-consistent solution of the Schrödinger and Poisson equations, numerous transformations between real and reciprocal space during the iterations can be avoided by using the presented method, which results in a significant reduction of computation time. Therefore, it is a promising tool for the simulation and efficient design of complex heterostructures such as terahertz quantum-cascade lasers.
Wavelet transform-based fault diagnosis and line selection method of small current grounding system
NASA Astrophysics Data System (ADS)
Yang, Ni; Zhang, Shuqing; Zhang, Liguo; Zhang, Kexin; Sun, Lingyun
2008-12-01
Small current grounding system is the system that the neutral point doesn't ground or grounds across the arc suppressing coils, which has been applied commonly in distribution system of many countries. As the grounding fault occurs, current is the one caused by capacity of circuit to ground only and it is rather small. The status of fault is complexity, e.g., the electromagnet interferes together with the amplified impact of zero-order loops to high-order singularity waves and various temporary variables. All these result in the lower ratio of the fault element signal to noise caused by zero-order current. In this paper, the position of signal singularity and the magnitude of the singularity degree are analyzed based on the variable focus character of wavelet, and the time fault occurs is then determined. The series db wavelet with close sustain is adopted, and the line selection is according to the zero-order voltage of the generatrix and the current of various outlet line. It is proved by the experiment that the fault circuit diagnosis method based on wavelet analysis to the character of temporary status of single-phase grounding fault plays an important role to a finer line selection.
Yu, Xiao; Ding, Enjie; Chen, Chunxu; Liu, Xiaoming; Li, Li
2015-01-01
Because roller element bearings (REBs) failures cause unexpected machinery breakdowns, their fault diagnosis has attracted considerable research attention. Established fault feature extraction methods focus on statistical characteristics of the vibration signal, which is an approach that loses sight of the continuous waveform features. Considering this weakness, this article proposes a novel feature extraction method for frequency bands, named Window Marginal Spectrum Clustering (WMSC) to select salient features from the marginal spectrum of vibration signals by Hilbert-Huang Transform (HHT). In WMSC, a sliding window is used to divide an entire HHT marginal spectrum (HMS) into window spectrums, following which Rand Index (RI) criterion of clustering method is used to evaluate each window. The windows returning higher RI values are selected to construct characteristic frequency bands (CFBs). Next, a hybrid REBs fault diagnosis is constructed, termed by its elements, HHT-WMSC-SVM (support vector machines). The effectiveness of HHT-WMSC-SVM is validated by running series of experiments on REBs defect datasets from the Bearing Data Center of Case Western Reserve University (CWRU). The said test results evidence three major advantages of the novel method. First, the fault classification accuracy of the HHT-WMSC-SVM model is higher than that of HHT-SVM and ST-SVM, which is a method that combines statistical characteristics with SVM. Second, with Gauss white noise added to the original REBs defect dataset, the HHT-WMSC-SVM model maintains high classification accuracy, while the classification accuracy of ST-SVM and HHT-SVM models are significantly reduced. Third, fault classification accuracy by HHT-WMSC-SVM can exceed 95% under a Pmin range of 500-800 and a m range of 50-300 for REBs defect dataset, adding Gauss white noise at Signal Noise Ratio (SNR) = 5. Experimental results indicate that the proposed WMSC method yields a high REBs fault classification accuracy and a
Yu, Xiao; Ding, Enjie; Chen, Chunxu; Liu, Xiaoming; Li, Li
2015-01-01
Because roller element bearings (REBs) failures cause unexpected machinery breakdowns, their fault diagnosis has attracted considerable research attention. Established fault feature extraction methods focus on statistical characteristics of the vibration signal, which is an approach that loses sight of the continuous waveform features. Considering this weakness, this article proposes a novel feature extraction method for frequency bands, named Window Marginal Spectrum Clustering (WMSC) to select salient features from the marginal spectrum of vibration signals by Hilbert–Huang Transform (HHT). In WMSC, a sliding window is used to divide an entire HHT marginal spectrum (HMS) into window spectrums, following which Rand Index (RI) criterion of clustering method is used to evaluate each window. The windows returning higher RI values are selected to construct characteristic frequency bands (CFBs). Next, a hybrid REBs fault diagnosis is constructed, termed by its elements, HHT-WMSC-SVM (support vector machines). The effectiveness of HHT-WMSC-SVM is validated by running series of experiments on REBs defect datasets from the Bearing Data Center of Case Western Reserve University (CWRU). The said test results evidence three major advantages of the novel method. First, the fault classification accuracy of the HHT-WMSC-SVM model is higher than that of HHT-SVM and ST-SVM, which is a method that combines statistical characteristics with SVM. Second, with Gauss white noise added to the original REBs defect dataset, the HHT-WMSC-SVM model maintains high classification accuracy, while the classification accuracy of ST-SVM and HHT-SVM models are significantly reduced. Third, fault classification accuracy by HHT-WMSC-SVM can exceed 95% under a Pmin range of 500–800 and a m range of 50–300 for REBs defect dataset, adding Gauss white noise at Signal Noise Ratio (SNR) = 5. Experimental results indicate that the proposed WMSC method yields a high REBs fault classification accuracy
NASA Astrophysics Data System (ADS)
Roulier, Rémy; Humeau, Anne; Flatley, Thomas P.; Abraham, Pierre
2005-11-01
A significant transient increase in laser Doppler flowmetry (LDF) signals is observed in response to a local and progressive cutaneous pressure application on healthy subjects. This reflex may be impaired in diabetic patients. The work presents a comparison between two signal processing methods that provide a clarification of this phenomenon. Analyses by the scalogram and the Hilbert-Huang transform (HHT) of LDF signals recorded at rest and during a local and progressive cutaneous pressure application are performed on healthy and type 1 diabetic subjects. Three frequency bands, corresponding to myogenic, neurogenic and endothelial related metabolic activities, are studied at different time intervals in order to take into account the dynamics of the phenomenon. The results show that both the scalogram and the HHT methods lead to the same conclusions concerning the comparisons of the myogenic, neurogenic and endothelial related metabolic activities—during the progressive pressure and at rest—in healthy and diabetic subjects. However, the HHT shows more details that may be obscured by the scalogram. Indeed, the non-locally adaptative limitations of the scalogram can remove some definition from the data. These results may improve knowledge on the above-mentioned reflex as well as on non-stationary biomedical signal processing methods.
Schullcke, Benjamin; Gong, Bo; Krueger-Ziolek, Sabine; Soleimani, Manuchehr; Mueller-Lisse, Ullrich; Moeller, Knut
2016-01-01
Lung EIT is a functional imaging method that utilizes electrical currents to reconstruct images of conductivity changes inside the thorax. This technique is radiation free and applicable at the bedside, but lacks of spatial resolution compared to morphological imaging methods such as X-ray computed tomography (CT). In this article we describe an approach for EIT image reconstruction using morphologic information obtained from other structural imaging modalities. This leads to recon- structed images of lung ventilation that can easily be superimposed with structural CT or MRI images, which facilitates image interpretation. The approach is based on a Discrete Cosine Transformation (DCT) of an image of the considered transversal thorax slice. The use of DCT enables reduction of the dimensionality of the reconstruction and ensures that only conductivity changes of the lungs are reconstructed and displayed. The DCT based approach is well suited to fuse morphological image information with functional lung imaging at low computational costs. Results on simulated data indicate that this approach preserves the morphological structures of the lungs and avoids blurring of the solution. Images from patient measurements reveal the capabilities of the method and demonstrate benefits in possible applications. PMID:27181695
NASA Astrophysics Data System (ADS)
Schullcke, Benjamin; Gong, Bo; Krueger-Ziolek, Sabine; Soleimani, Manuchehr; Mueller-Lisse, Ullrich; Moeller, Knut
2016-05-01
Lung EIT is a functional imaging method that utilizes electrical currents to reconstruct images of conductivity changes inside the thorax. This technique is radiation free and applicable at the bedside, but lacks of spatial resolution compared to morphological imaging methods such as X-ray computed tomography (CT). In this article we describe an approach for EIT image reconstruction using morphologic information obtained from other structural imaging modalities. This leads to recon- structed images of lung ventilation that can easily be superimposed with structural CT or MRI images, which facilitates image interpretation. The approach is based on a Discrete Cosine Transformation (DCT) of an image of the considered transversal thorax slice. The use of DCT enables reduction of the dimensionality of the reconstruction and ensures that only conductivity changes of the lungs are reconstructed and displayed. The DCT based approach is well suited to fuse morphological image information with functional lung imaging at low computational costs. Results on simulated data indicate that this approach preserves the morphological structures of the lungs and avoids blurring of the solution. Images from patient measurements reveal the capabilities of the method and demonstrate benefits in possible applications.
NASA Astrophysics Data System (ADS)
Chiba, Ryoichi
2012-02-01
This article analyzes the one-dimensional steady temperature field and related thermal stresses in an annular disk of variable thickness that has a temperature-dependent heat transfer coefficient and is capable of temperature-dependent internal heat generation. The temperature dependencies of the thermal conductivity, Young's modulus, and the coefficient of linear thermal expansion of the disk are considered, whereas Poisson's ratio is assumed to be constant. The differential transform method (DTM) is employed to analyze not only the nonlinear heat conduction but also the resulting thermal stresses. Analytical solutions are developed for the temperature and thermal stresses in the form of simple power series. Numerical calculations are performed for an annular cooling/heating fin of variable thickness. Numerical results show that the sufficiently converged analytical solutions are in good agreement with the solutions obtained by the Adomian decomposition method and give the effects of the temperature-dependent parameters on the temperature and thermal stress profiles in the disk. The DTM is useful as a new analytical method for solving thermoelastic problems for a body with temperature-dependent parameters including material properties.
Cho, Yi-Gil; Kim, Jin-You; Cho, Hoon-Hwe; Cha, Pil-Ryung; Suh, Dong-Woo; Lee, Jae Kon; Han, Heung Nam
2012-01-01
An implicit finite element model was developed to analyze the deformation behavior of low carbon steel during phase transformation. The finite element model was coupled hierarchically with a phase field model that could simulate the kinetics and micro-structural evolution during the austenite-to-ferrite transformation of low carbon steel. Thermo-elastic-plastic constitutive equations for each phase were adopted to confirm the transformation plasticity due to the weaker phase yielding that was proposed by Greenwood and Johnson. From the simulations under various possible plastic properties of each phase, a more quantitative understanding of the origin of transformation plasticity was attempted by a comparison with the experimental observation. PMID:22558295
Cho, Yi-Gil; Kim, Jin-You; Cho, Hoon-Hwe; Cha, Pil-Ryung; Suh, Dong-Woo; Lee, Jae Kon; Han, Heung Nam
2012-01-01
An implicit finite element model was developed to analyze the deformation behavior of low carbon steel during phase transformation. The finite element model was coupled hierarchically with a phase field model that could simulate the kinetics and micro-structural evolution during the austenite-to-ferrite transformation of low carbon steel. Thermo-elastic-plastic constitutive equations for each phase were adopted to confirm the transformation plasticity due to the weaker phase yielding that was proposed by Greenwood and Johnson. From the simulations under various possible plastic properties of each phase, a more quantitative understanding of the origin of transformation plasticity was attempted by a comparison with the experimental observation. PMID:22558295
Zarkevich, N. A.; Johnson, D. D.
2015-08-14
We extend the solid-state nudged elastic band method to handle a non-conserved order parameter, in particular, magnetization, that couples to volume and leads to many observed effects in magnetic systems. We apply this formalism to the well-studied magneto-volume collapse during the pressure-induced transformation in iron—from ferromagnetic body-centered cubic (bcc) austenite to hexagonal close-packed (hcp) martensite. We also find a bcc-hcp equilibrium coexistence pressure of 8.4 GPa, with the transition-state enthalpy of 156 meV/Fe at this pressure. A discontinuity in magnetization and coherent stress occurs at the transition state, which has a form of a cusp on the potential-energy surface (yet all the atomic and cell degrees of freedom are continuous); the calculated pressure jump of 25 GPa is related to the observed 25 GPa spread in measured coexistence pressures arising from martensitic and coherency stresses in samples. Furthermore, our results agree with experiments, but necessarily differ from those arising from drag and restricted parametrization methods having improperly constrained or uncontrolled degrees of freedom.
Zarkevich, N. A. E-mail: ddj@ameslab.gov; Johnson, D. D. E-mail: ddj@ameslab.gov
2015-08-14
We extend the solid-state nudged elastic band method to handle a non-conserved order parameter, in particular, magnetization, that couples to volume and leads to many observed effects in magnetic systems. We apply this formalism to the well-studied magneto-volume collapse during the pressure-induced transformation in iron—from ferromagnetic body-centered cubic (bcc) austenite to hexagonal close-packed (hcp) martensite. We find a bcc-hcp equilibrium coexistence pressure of 8.4 GPa, with the transition-state enthalpy of 156 meV/Fe at this pressure. A discontinuity in magnetization and coherent stress occurs at the transition state, which has a form of a cusp on the potential-energy surface (yet all the atomic and cell degrees of freedom are continuous); the calculated pressure jump of 25 GPa is related to the observed 25 GPa spread in measured coexistence pressures arising from martensitic and coherency stresses in samples. Our results agree with experiments, but necessarily differ from those arising from drag and restricted parametrization methods having improperly constrained or uncontrolled degrees of freedom.
The Hilbert-Huang Transform-Based Denoising Method for the TEM Response of a PRBS Source Signal
NASA Astrophysics Data System (ADS)
Hai, Li; Guo-qiang, Xue; Pan, Zhao; Hua-sen, Zhong; Khan, Muhammad Younis
2016-05-01
The denoising process is critical in processing transient electromagnetic (TEM) sounding data. For the full waveform pseudo-random binary sequences (PRBS) response, an inadequate noise estimation may result in an erroneous interpretation. We consider the Hilbert-Huang transform (HHT) and its application to suppress the noise in the PRBS response. The focus is on the thresholding scheme to suppress the noise and the analysis of the signal based on its Hilbert time-frequency representation. The method first decomposes the signal into the intrinsic mode function, and then, inspired by the thresholding scheme in wavelet analysis; an adaptive and interval thresholding is conducted to set to zero all the components in intrinsic mode function which are lower than a threshold related to the noise level. The algorithm is based on the characteristic of the PRBS response. The HHT-based denoising scheme is tested on the synthetic and field data with the different noise levels. The result shows that the proposed method has a good capability in denoising and detail preservation.
Chen, L; Carpita, N C; Reiter, W D; Wilson, R H; Jeffries, C; McCann, M C
1998-11-01
We have developed a rapid method to screen large numbers of mutant plants for a broad range of cell wall phenotypes using Fourier transform infrared (FTIR) microspectroscopy of leaves. We established and validated a model that can discriminate between the leaves of wild-type and a previously defined set of cell-wall mutants of Arabidopsis. Exploratory principal component analysis indicated that mutants deficient in different cell-wall sugars can be distinguished from each other. Discrimination of cell-wall mutants from wild-type was independent of variability in starch content or additional unrelated mutations that might be present in a heavily mutagenised population. We then developed an analysis of FTIR spectra of leaves obtained from over 1000 mutagenised flax plants, and selected 59 plants whose spectral variation from wild-type was significantly out of the range of a wild-type population, determined by Mahalanobis distance. Cell wall sugars from the leaves of selected putative mutants were assayed by gas chromatography-mass spectrometry and 42 showed significant differences in neutral sugar composition. The FTIR spectra indicated that six of the remaining 17 plants have altered ester or protein content. We conclude that linear discriminant analysis of FTIR spectra is a robust method to identify a broad range of structural and architectural alterations in cell walls, appearing as a consequence of developmental regulation, environmental adaptation or genetic modification. PMID:9881159
The Hilbert-Huang Transform-Based Denoising Method for the TEM Response of a PRBS Source Signal
NASA Astrophysics Data System (ADS)
Hai, Li; Guo-qiang, Xue; Pan, Zhao; Hua-sen, Zhong; Khan, Muhammad Younis
2016-08-01
The denoising process is critical in processing transient electromagnetic (TEM) sounding data. For the full waveform pseudo-random binary sequences (PRBS) response, an inadequate noise estimation may result in an erroneous interpretation. We consider the Hilbert-Huang transform (HHT) and its application to suppress the noise in the PRBS response. The focus is on the thresholding scheme to suppress the noise and the analysis of the signal based on its Hilbert time-frequency representation. The method first decomposes the signal into the intrinsic mode function, and then, inspired by the thresholding scheme in wavelet analysis; an adaptive and interval thresholding is conducted to set to zero all the components in intrinsic mode function which are lower than a threshold related to the noise level. The algorithm is based on the characteristic of the PRBS response. The HHT-based denoising scheme is tested on the synthetic and field data with the different noise levels. The result shows that the proposed method has a good capability in denoising and detail preservation.
Recursion-Transform method to a non-regular m×n cobweb with an arbitrary longitude
Tan, Zhi-Zhong
2015-01-01
A general Recursion-Transform method is put forward and is applied to resolving a difficult problem of the two-point resistance in a non-regular m × n cobweb network with an arbitrary longitude (or call radial), which has never been solved before as the Green’s function technique and the Laplacian matrix approach are difficult in this case. Looking for the explicit solutions of non-regular lattices is important but difficult, since the non-regular condition is like a wall or trap which affects the behavior of finite network. This paper gives several general formulae of the resistance between any two nodes in a non-regular cobweb network in both finite and infinite cases by the R-T method which, is mainly composed of the characteristic roots, is simpler and can be easier to use in practice. As applications, several interesting results are deduced from a general formula, and a globe network is generalized. PMID:26073882
Zarkevich, N. A.; Johnson, D. D.
2015-08-14
We extend the solid-state nudged elastic band method to handle a non-conserved order parameter, in particular, magnetization, that couples to volume and leads to many observed effects in magnetic systems. We apply this formalism to the well-studied magneto-volume collapse during the pressure-induced transformation in iron—from ferromagnetic body-centered cubic (bcc) austenite to hexagonal close-packed (hcp) martensite. We also find a bcc-hcp equilibrium coexistence pressure of 8.4 GPa, with the transition-state enthalpy of 156 meV/Fe at this pressure. A discontinuity in magnetization and coherent stress occurs at the transition state, which has a form of a cusp on the potential-energy surface (yetmore » all the atomic and cell degrees of freedom are continuous); the calculated pressure jump of 25 GPa is related to the observed 25 GPa spread in measured coexistence pressures arising from martensitic and coherency stresses in samples. Furthermore, our results agree with experiments, but necessarily differ from those arising from drag and restricted parametrization methods having improperly constrained or uncontrolled degrees of freedom.« less
NASA Astrophysics Data System (ADS)
Bonhivers, Jean-Christophe
The increase in production of goods over the last decades has led to the need for improving the management of natural resources management and the efficiency of processes. As a consequence, heat integration methods for industry have been developed. These have been successful for the design of new plants: the integration principles are largely employed, and energy intensity has dramatically decreased in many processes. Although progress has also been achieved in integration methods for retrofit, these methods still need further conceptual development. Furthermore, methodological difficulties increase when trying to retrofit heat exchange networks that are closely interrelated to water networks, such as the case of pulp and paper mills. The pulp and paper industry seeks to increase its profitability by reducing production costs and optimizing supply chains. Recent process developments in forestry biorefining give this industry the opportunity for diversification into bio-products, increasing potential profit margins, and at the same time modernizing its energy systems. Identification of energy strategies for a mill in a changing environment, including the possibility of adding a biorefinery process on the industrial site, requires better integration methods for retrofit situations. The objective of this thesis is to develop an energy integration method for the retrofit of industrial systems and the transformation of pulp and paper mills, ant to demonstrate the method in case studies. Energy is conserved and degraded in a process. Heat can be converted into electricity, stored as chemical energy, or rejected to the environment. A systematic analysis of successive degradations of energy between the hot utilities until the environment, through process operations and existing heat exchangers, is essential in order to reduce the heat consumption. In this thesis, the "Bridge Method" for energy integration by heat exchanger network retrofit has been developed. This method
NASA Astrophysics Data System (ADS)
Gurovich, B. A.; Dolgii, D. I.; Kuleshova, E. A.; Velikhov, E. P.; Ol'shanskii, E. D.; Domantovskii, A. G.; Aronzon, B. A.; Meilikhov, Evgenii Z.
2001-01-01
The key condition for radical progress in technology in the 21th century is the availability of a technique for the controlled production in a solid of 3D patterns incorporating regions of desired physical and chemical properties, with the possibility of downsizing pattern elements to the nanometer scale being a crucial requirement. In this paper, a method for changing the electrical, magnetic, optical and other key physical properties in a direct and deliberate manner by radically modifying the solid's atomic composition is proposed for the first time. The physical foundation of the new nonlithography technology is the observation — thoroughly investigated and well verified in our numerous experiments — that accelerated particle beams can be used to selectively remove atoms from thin films of di- or polyatomic compounds. It is shown, in particular, that by selectively removing atoms of a given sort, dielectrics can be transformed into metals or semiconductors, nonmagnetic materials into magnetic ones, and the optical and other properties of materials can be changed radically. The selective removal of atoms of a specified sort from a material is of great interest for future technologies, especially for those relevant to nanoelectronics and, more broadly, to the numerous 'nanoproblems' ahead in the third millennium.
NASA Astrophysics Data System (ADS)
Salman, Ahmad; Lapidot, Itshak; Pomerantz, Ami; Tsror, Leah; Shufan, Elad; Moreh, Raymond; Mordechai, Shaul; Huleihel, Mahmoud
2012-01-01
The early diagnosis of phytopathogens is of a great importance; it could save large economical losses due to crops damaged by fungal diseases, and prevent unnecessary soil fumigation or the use of fungicides and bactericides and thus prevent considerable environmental pollution. In this study, 18 isolates of three different fungi genera were investigated; six isolates of Colletotrichum coccodes, six isolates of Verticillium dahliae and six isolates of Fusarium oxysporum. Our main goal was to differentiate these fungi samples on the level of isolates, based on their infrared absorption spectra obtained using the Fourier transform infrared-attenuated total reflection (FTIR-ATR) sampling technique. Advanced statistical and mathematical methods: principal component analysis (PCA), linear discriminant analysis (LDA), and k-means were applied to the spectra after manipulation. Our results showed significant spectral differences between the various fungi genera examined. The use of k-means enabled classification between the genera with a 94.5% accuracy, whereas the use of PCA [3 principal components (PCs)] and LDA has achieved a 99.7% success rate. However, on the level of isolates, the best differentiation results were obtained using PCA (9 PCs) and LDA for the lower wavenumber region (800-1775 cm-1), with identification success rates of 87%, 85.5%, and 94.5% for Colletotrichum, Fusarium, and Verticillium strains, respectively.
Markopoulou, C K; Koundourellis, J E; Orkoula, M G; Kontoyannis, C G
2008-02-01
Two different nondestructive spectroscopy methods based on near-infrared (NIR) and Fourier transform (FT) Raman spectroscopy were developed for the determination of ticlopidine-hydrochloride (TCL) in pharmaceutical formulations and the results were compared to those obtained by high-performance liquid chromatography (HPLC). An NIR assay was performed by reflectance over the 850-1700 nm region using a partial least squares (PLS) prediction model, while the absolute FT-Raman intensity of TCL's most intense vibration was used for constructing the calibration curve. For both methodologies the spectra were obtained from the as-received film-coated tablets of TCL. The two quantitative techniques were built using five "manual compressed" tablets containing different concentrations and validated by evaluating the calibration model as well as the accuracy and precision. The models were applied to commercial preparations (Ticlid). The results were compared to those obtained from the application of HPLC using the methodology described by "Sanofi Research Department" and were found to be in excellent agreement, proving that NIR, using fiber-optic probes, and FT-Raman spectroscopy can be used for the fast and reliable determination of the major component in pharmaceutical analysis. PMID:18284803
Schechtman, L M; Kiss, E; McCarvill, J; Nims, R; Kouri, R E; Lubet, R A
1987-09-01
A method has been developed by which to amplify expression of phenotypic transformation of C3H/10T1/2 clone 8 mouse embryo cells not otherwise observed in the standard transformation assay. The expression of transformed foci was amplified by subcultivating chemically treated target cells after they had reached confluence and replating them at subconfluent cell densities. Conditions leading to the expression of the highest numbers of transformed foci include a) a cell seeding density for chemical treatment of 1 X 10(4) cells/dish, b) subculture 4 weeks after treatment, and c) replating cells at a density of 2 X 10(5) cells/-dish. Agents capable of inducing transformation in the standard assay (e.g., 4,4'-bis(dimethylamino)benzophenone, benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene, and others) also yielded transformation in the replating assay. The more marginal transforming activities of chemicals such as ethyl methanesulfonate, 7-(bromomethyl)-12-methylbenz[a]anthracene, and N-methyl-N'-nitro-N-nitrosoguanidine were enhanced by the amplification procedure. Compounds that failed to elicit focal transformation in the standard assay (e.g., dibenz[a,h]anthracene, Tris(2,3-dibromopropyl) phosphate, lead acetate, benzidine, propyleneimine, N-hydroxy-2-fluorenylacetamide, and numerous other compounds of various chemical classes) induced significant levels of phenotypic transformation upon amplification. Noncarcinogens (e.g., phenanthrene, anthracene, 2-aminobiphenyl, cycloheximide, and others) failed to cause significant phenotypic transformation even when cells were replated. To further enhance the applicability of this new replating system, an exogenous source of metabolic activation was added: a 9,000 X g supernatant from Aroclor 1254-induced rat hepatic S-9. This activation system was found a) to be only minimally cytotoxic by itself and b) to be able to mediate NADPH-dependent, dose-dependent toxicity, and transformation by activating the procarcinogens
Basiri Parsa, A; Rashidi, M M; Anwar Bég, O; Sadri, S M
2013-09-01
In this paper, the semi-numerical techniques known as the optimal homotopy analysis method (HAM) and Differential Transform Method (DTM) are applied to study the magneto-hemodynamic laminar viscous flow of a conducting physiological fluid in a semi-porous channel under a transverse magnetic field. The two-dimensional momentum conservation partial differential equations are reduced to ordinary form incorporating Lorentizian magnetohydrodynamic body force terms. These ordinary differential equations are solved by the homotopy analysis method, the differential transform method and also a numerical method (fourth-order Runge-Kutta quadrature with a shooting method), under physically realistic boundary conditions. The homotopy analysis method contains the auxiliary parameter ℏ, which provides us with a simple way to adjust and control the convergence region of solution series. The differential transform method (DTM) does not require an auxiliary parameter and is employed to compute an approximation to the solution of the system of nonlinear differential equations governing the problem. The influence of Hartmann number (Ha) and transpiration Reynolds number (mass transfer parameter, Re) on the velocity profiles in the channel are studied in detail. Interesting fluid dynamic characteristics are revealed and addressed. The HAM and DTM solutions are shown to both correlate well with numerical quadrature solutions, testifying to the accuracy of both HAM and DTM in nonlinear magneto-hemodynamics problems. Both these semi-numerical techniques hold excellent potential in modeling nonlinear viscous flows in biological systems. PMID:23930807
Arnold, W
1989-01-01
The Fourier-Transform-Infrared spectrometry (FTIR) is a very valuable technique for identifying organic substances. FTIR is more versatile in comparison to disperse infrared spectrometry, as it combines speed and sensitivity. FTIR is even superior to GC/MS: 1. Easy differentiation between isomers is possible. 2. Functional group information can be achieved instead of mass fragments. 3. GC fractions can be saved for further analysis. The FTIR instrument has no prisma or grating. It is equipped with a Michelson interferometer, which gives much more beam energy on the examination object. Most beneficial is the use of a broadband beam source, which impinges simultaneously all frequencies on the sample and on the detector. All these qualities allow the registration of fast chemical and biological processes or the observation of all reactions by volatizing and evaporation at high temperatures. IR spectrometer can run high quality infrared spectra in short time (almost 100/second) with high sensitivity. This is the basic requirement for the "on line" coupling of the IR-system with a GC. The GC peaks are analysed by IR beams with the help of a "light pipe". It is possible to examine all kinds of substances with diffuse and attenuated total reflectance methods. In special cases the change for binding of proteins and kinetic and structural processes in the flowing blood can be measured in vivo. Another use of FTIR-techniques is possible in combination with a microscope. Samples with a square aera of 8 microns can be examined. In criminalistics and forensic toxicology little particles as hairs, fibers, foams, adherents of powder in clothes, splinters of lacquer and paints etc. can be detected and identified by transmission or reflection. In conclusion, the FTIR spectrometry offers a versatility to some measurement problems that is often superior, faster and easier than other techniques such as NMR and MS. PMID:2818470
Pantazis, Christopher J; Fisk, Sarah; Mills, Kerri; Flinn, Barry S; Shulaev, Vladimir; Veilleux, Richard E; Dan, Yinghui
2013-03-01
KEY MESSAGE : We developed an efficient Agrobacterium -mediated transformation method using an Ac/Ds transposon tagging construct for F. vesca and high throughput paromomycin spray assay to identify its transformants for strawberry functional genomics. Genomic resources for Rosaceae species are now readily available, including the Fragaria vesca genome, EST sequences, markers, linkage maps, and physical maps. The Rosaceae Genomic Executive Committee has promoted strawberry as a translational genomics model due to its unique biological features and transformability for fruit trait improvement. Our overall research goal is to use functional genomic and metabolic approaches to pursue high throughput gene discovery in the diploid woodland strawberry. F. vesca offers several advantages of a fleshy fruit typical of most fruit crops, short life cycle (seed to seed in 12-16 weeks), small genome size (206 Mbb/C), small plant size, self-compatibility, and many seeds per plant. We have developed an efficient Agrobacterium tumefaciens-mediated strawberry transformation method using kanamycin selection, and high throughput paromomycin spray assay to efficiently identify transgenic strawberry plants. Using our kanamycin transformation method, we were able to produce up to 98 independent kanamycin resistant insertional mutant lines using a T-DNA construct carrying an Ac/Ds transposon Launchpad system from a single transformation experiment involving inoculation of 22 leaf explants of F. vesca accession 551572 within approx. 11 weeks (from inoculation to soil). Transgenic plants with 1-2 copies of a transgene were confirmed by Southern blot analysis. Using our paromomycin spray assay, transgenic F. vesca plants were rapidly identified within 10 days after spraying. PMID:23160638
Micro-shock Wave Assisted Plant Transformation
NASA Astrophysics Data System (ADS)
Gnanadhas, Divya Prakash; Datey, Akshay; Chakravortty, Dipshikha; Gopalan, Jagadeesh
Genetically modified (GM) crops are developed by transforming the desired DNA to plant. There are various methods employed to achieve the required transformation in plants. Agrobacterium mediated transformation and Biolistics or particle bombardment method are the most commonly used methods.
NASA Astrophysics Data System (ADS)
Takami, Jun; Tsuboi, Toshihiro; Okabe, Shigemitsu
The power frequency withstand voltage tests are specified on electric power equipment in JEC-0102 by evaluating the lifetime reliability with a Weibull distribution function. It may be applied on 66-154kV transformer for non-effectively grounded voltage class. The present paper describes the results that measured AC insulation characteristics (Voltage-time characteristics) and Weibull parameters for oil-filled transformer of 66-154kV class. These measurement parameters were compared with the conventional Weibull parameters, which were applied for oil-filled transformer of voltage class above 154kV. Furthermore the non-partial discharge test voltage was evaluated by trial calculations, using the parameters obtained this time or typical parameters.
NASA Technical Reports Server (NTRS)
Klimas, A. J.
1983-01-01
A numerical method is presented for studying one-dimensional electron plasma evolution under typical interplanetary conditions. The method applies the Fourier-Fourier transform approach to a plasma model that is a generalization of the electrostatic Vlasov-Poisson system of equations. Conservation laws that are modified to include the plasma model generalization and also the boundary effects of nonperiodic solutions are given. A new conservation law for entropy in the transformed space is then introduced. These conservation laws are used to verify the numerical solutions. A discretization error analysis is presented. Two numerical instabilities and the methods used for their suppression are treated. It is shown that in interplanetary plasma conditions, the bump-on-tail instability produces significant excitation of plasma oscillations at the Bohm-Gross frequency and its second harmonic. An explanation of the second harmonic excitation is given in terms of wave-wave coupling during the growth phase of the instability.
NASA Astrophysics Data System (ADS)
Iadicola, M. A.; Shaw, J. A.
2007-02-01
An experimental configuration is demonstrated that captures features of the initiation of unstable stress-induced transformation in a shape memory alloy (SMA). The apparatus uses circulating fluids through the grips and a heat sink and thermoelectric devices to control the temperature profile of a specimen within a mechanical testing machine. The configuration can be used to restrict the initiation of phase transformation to a small region of interest of the free length, while permitting full-field optical tracking, infrared imaging, use of laser extensometry, and monitoring of load and extension. In this way, some longstanding difficulties in the measurement of thermo-mechanical phenomena in SMA wire have been resolved. The size of initiation stress peaks can be accurately measured for both transformation directions without changing the wire geometry, the temperature of a region of interest can be selected over a wide range, and imaging can be performed for multiple loading cycles and for events that occur from static to near dynamic rates. The motivation for this work is to produce high quality data for use in calibrating numerical models that study thermo-mechanical coupling during unstable transformation behavior.
Technology Transfer Automated Retrieval System (TEKTRAN)
Diffuse-Reflectance Fourier-Transform Mid-Infrared Spectroscopy (FTIR) can be used quickly and non destructively to identify and quantify the presence of important organic functional groups in environmental samples. However, soils contain myriad organic and inorganic components that absorb in the M...
Technology Transfer Automated Retrieval System (TEKTRAN)
Diffuse-Reflectance Fourier-Transform Mid-Infrared Spectroscopy (MidIR) can identify the presence of important organic functional groups in soil organic matter (SOM). Soils contain myriad organic and inorganic components that absorb in the MidIR so spectral interpretation needs to be validated in or...
NASA Astrophysics Data System (ADS)
Bardainne, T.; Gaillot, P.; Senechal, G.
2004-12-01
Whole waveform records of waves radiated by induced-seismic events contain considerable information on event location, propagation medium, failure type, source size, and state of stress. Modern seismological studies of induced-seismicity related with hydrocarbons exploitation or storage benefit from time-frequency (TF) analysis techniques such as the windowed Fourier transform or the wavelet transform. These TF representations with fixed windows or kernels perform well only for limited classes of seismograms. Representations with signal-dependent kernels can overcome this limitation. A new five-parameter atomic decomposition of chirplets is developed for compact and precise representation of seismograms with chirp components. The five-parameter chirplet atom is obtained from the unit Gaussian function by successive applications of scaling, fractional Fourier transform, time-shift and frequency-shift operators of various duration. So, the chirplet transform unifies many of the disparate signal representation methods. In particular, the wide-range of TF methods such as the Fourier transform, spectrogram, Wigner distribution, and wavelet transform may each be shown to be a special case of the chirplet transform. We developed a methodology that recognizes the attributes of the waveforms of each seismic events. We first present and illustrate on synthetic examples this new formalism. Next, we illustrate its potentialities on seismograms recorded by 17 seismometers (Mark-Product L-4C - 12 bits) during the monitoring period (1974-1997) of the Lacq gas field (Western Pyrenees, France). Using the chirplet transform, each wave packet of the seismogram (mostly single component, sampling frequency = 150 Hz, duration = 15 s) is decomposed in terms of energy, arrival time, frequency, duration, shape (time-shear) and frequency modulation (frequency-shear). Thus, selected seismograms (N ˜ 5500 for 592 well-localized events) are described by a set of sextuplets which provide
Wei, Ru-Yi; Zhou, Jin-Song; Zhang, Xue-Min; Yu, Tao; Gao, Xiao-Hui; Ren, Xiao-Qiang
2014-11-01
The present paper describes the observations and measurements of the infrared absorption spectra of CO2 on the Earth's surface with OP/FTIR method by employing a mid-infrared reflecting scanning Fourier transform spectrometry, which are the first results produced by the first prototype in China developed by the team of authors. This reflecting scanning Fourier transform spectrometry works in the spectral range 2 100-3 150 cm(-1) with a spectral resolution of 2 cm(-1). Method to measure the atmospheric molecules was described and mathematical proof and quantitative algorithms to retrieve molecular concentration were established. The related models were performed both by a direct method based on the Beer-Lambert Law and by a simulating-fitting method based on HITRAN database and the instrument functions. Concentrations of CO2 were retrieved by the two models. The results of observation and modeling analyses indicate that the concentrations have a distribution of 300-370 ppm, and show tendency that going with the variation of the environment they first decrease slowly and then increase rapidly during the observation period, and reached low points in the afternoon and during the sunset. The concentrations with measuring times retrieved by the direct method and by the simulating-fitting method agree with each other very well, with the correlation of all the data is up to 99.79%, and the relative error is no more than 2.00%. The precision for retrieving is relatively high. The results of this paper demonstrate that, in the field of detecting atmospheric compositions, OP/FTIR method performed by the Infrared reflecting scanning Fourier transform spectrometry is a feasible and effective technical approach, and either the direct method or the simulating-fitting method is capable of retrieving concentrations with high precision. PMID:25752042
Dr. Manish Metha; Dr. Tom Oakwood
2004-04-28
The purpose of this collaborative project was to develop a standard practice for obtaining and archiving quantitative steel transformation kinetic data and thermal strain data. Two families of dilatometric equipment were employed to develop this standard practice for testing bar product steels. These include high-speed quenching and deformation dilatometers and Gleeble{reg_sign} thermomechanical simulation instruments. Standard measurement, data interpretation and data reporting methods were developed and defined by the cross-industry QMST Consortium members consisting of steel-manufacturers, forgers, heat-treaters, modelers, automotive and heavy vehicle OEMs along with team expert technologists from the National Labs and academia. The team designed phase transformation experiments on two selected steel grades to validate the standard practices--a medium carbon grade SAE 1050 and an alloy steel SAE 8620. A final standard practice document was developed based on the two dilatometry methods, and was submitted to and approved by ASTM (available as A1033-04). The standard practice specifies a method for measuring austenite transformation under no elastic stress or plastic deformation. These methods will be an enabler for the development and electronic archiving of a quantitative database for process modeling using computer simulation software, and will greatly assist endusers in developing accurate process and product simulations during the thermo-mechanical processing of bar and rod product steels.
NASA Astrophysics Data System (ADS)
Yoshizawa, Terutaka; Hada, Masahiko
2013-08-01
We propose a novel Foldy-Wouthuysen transformation including a vector potential A, which can be used to introduce restricted magnetic balance in the Douglas-Kroll-Hess (DKH) method. We also demonstrate that the DKH method can be used in combination with the gauge-including atomic orbital method. For the numerical examination, we calculate the NMR shielding constants and anisotropies of noble gas atoms (Ne, Ar, Kr, Xe), halogens (F, Cl, Br, I), and chalcogens (O, S, Se, Te) in molecules without using extremely large basis sets.
Schroyer, B.R.; Capel, P.D.
1996-01-01
A high-performance liquid Chromatography (HPLC) method is presented for the for the fast, quantitative analysis of the target analytes in water and in low organic-carbon, sandy soils that are known to be contaminated with the parent herbicides. Speed and ease of sample preparation was prioritized above minimizing detection limits. Soil samples were extracted using 80:20 methanol:water (volume:volume). Water samples (50 ??L) were injected directly into the HPLC without prior preparation. Method quantification limits for soil samples (10 g dry weight) and water samples ranged from 20 to 110 ng/g and from 20 to 110 ??g/L for atrazine and its transformation products and from 80 to 320 ng/g and from 80 to 320 ??g/L for alachlor and its transformation products, respectively.
Jameson, Donald L; Field, Thomas; Schmidt, Monica R; DeStefano, Alyson K; Stiteler, Christopher J; Venditto, Vincent J; Krovic, Brooke; Hoffman, Christopher M; Ondisco, Matthew T; Belowich, Matthew E
2013-11-15
A general method for the gram scale resolution of 2-substituted and 2,8-disubstituted Tröger's base (TB) derivatives in 63-91% yield has been achieved through the application of crystallization-induced asymmetric transformation (CIAT). Enantiomeric ratios of the resolved TB derivatives range from 99.1:0.9 to >99.5:0.5. Among the Tröger's base compounds resolved are four synthetically valuable bromo and iodo derivatives. PMID:24116701
Bukovinszki, Agnes; Divéki, Zoltán; Csányi, Márta; Palkovics, László; Balázs, Ervin
2007-04-01
In this work, Potato virus Y (PVY) resistant potatoes were generated using an environmentally safe construct. For this purpose, a 'shooter' mutant Agrobacterium-based transformation system was used. The isopentenyl transferase gene (ipt) present on the Ti plasmid of 'shooter' strains enhances shoot regeneration and can be used as a phenotypic selection marker. The introduced marker-free binary vector carried a hairpin construct derived from the coat protein gene of PVY-NTN strain in order to induce gene silencing. Transformation resulted in high regeneration rates (1.4-5.7 shoots per explant). With pre-selection for the ipt (+) phenotype the transformation frequency was 24-53%, while without selection 12-28% of the shoots were PCR positive. The presence of the transgene was verified by Southern hybridization. In 16 of 31 challenged transformant lines PVY could be detected neither by RT-PCR nor by back inoculation. A 62.5% of these resistant lines proved to be also ipt-free. This transformation system was reproducible in four potato cultivars, suggesting that it could easily be adapted for other species. PMID:17103215
Choi, Kyoo Sil; Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Ren, Yang; Wang, Yan-Dong
2008-12-01
Compared to other advanced high-strength steels, TRIP (Transformation-Induced Plasticity) steels exhibit better ductility at a given strength level and can be used to produce complicated automotive parts. This enhanced formability comes from the transformation of retained austenite to martensite during plastic deformation. In this study, as a first step in predicting optimum processing parameters in TRIP steel productions, a micromechanical finite element model is developed based on the actual microstructure of a TRIP 800 steel. The method uses microstructure-based representative volume element (RVE) to capture the complex deformation behavior of TRIP steels. The mechanical properties of the constituent phases of the TRIP 800 steel and the fitting parameters of the martensite transformation kinetics are determined using the synchrotron-based in-situ high-energy X-ray diffraction (HEXRD) measurements of a uniaxial tensile test. The experimental results suggest that the HEXRD technique provides a powerful tool for characterizing the phase transformation and the microstress of each phase of TRIP steels during deformation. The computational results suggest that the response of the RVE well represents the overall macroscopic behavior of the TRIP 800 steel under deformation. The methodology described in this study may be used in studying the effects of the various processing parameters on the macroscopic behaviors of TRIP steels.
Choi, K. S.; Liu, W. N.; Sun, X.; Khaleel, M.A.; Ren, Y.; Wang, Y.D.; X-Ray Science Division; PNNL; Northeastern Univ.
2008-12-01
Compared to other advanced high-strength steels, transformation-induced plasticity (TRIP) steels exhibit better ductility at a given strength level and can be used to produce complicated automotive parts. This enhanced formability comes from the transformation of retained austenite to martensite during plastic deformation. In this study, as a first step in predicting optimum processing parameters in TRIP steel productions, a micromechanical finite element model is developed based on the actual microstructure of a TRIP 800 steel. The method uses a microstructure-based representative volume element (RVE) to capture the complex deformation behavior of TRIP steels. The mechanical properties of the constituent phases of the TRIP 800 steel and the fitting parameters describing the martensite transformation kinetics are determined using the synchrotron-based in-situ high-energy X-ray diffraction (HEXRD) experiments performed under a uniaxial tensile deformation. The experimental results suggest that the HEXRD technique provides a powerful tool for characterizing the phase transformation behavior and the microstress developed due to the phase-to-phase interaction of TRIP steels during deformation. The computational results suggest that the response of the RVE well represents the overall macroscopic behavior of the TRIP 800 steel under deformation. The methodology described in this study may be extended for studying the effects of the various processing parameters on the macroscopic behaviors of TRIP steels.
Chen, Hong-Yan; Zhao, Geng-Xing; Li, Xi-Can; Wang, Xiang-Feng; Li, Yu-Ling
2013-11-01
Taking the Qihe County in Shandong Province of East China as the study area, soil samples were collected from the field, and based on the hyperspectral reflectance measurement of the soil samples and the transformation with the first deviation, the spectra were denoised and compressed by discrete wavelet transform (DWT), the variables for the soil alkali hydrolysable nitrogen quantitative estimation models were selected by genetic algorithms (GA), and the estimation models for the soil alkali hydrolysable nitrogen content were built by using partial least squares (PLS) regression. The discrete wavelet transform and genetic algorithm in combining with partial least squares (DWT-GA-PLS) could not only compress the spectrum variables and reduce the model variables, but also improve the quantitative estimation accuracy of soil alkali hydrolysable nitrogen content. Based on the 1-2 levels low frequency coefficients of discrete wavelet transform, and under the condition of large scale decrement of spectrum variables, the calibration models could achieve the higher or the same prediction accuracy as the soil full spectra. The model based on the second level low frequency coefficients had the highest precision, with the model predicting R2 being 0.85, the RMSE being 8.11 mg x kg(-1), and RPD being 2.53, indicating the effectiveness of DWT-GA-PLS method in estimating soil alkali hydrolysable nitrogen content. PMID:24564148
Rapid Transformation Annealing: a Novel Method for Grain Refinement of Cold-Rolled Low-Carbon Steels
NASA Astrophysics Data System (ADS)
Lesch, C.; Álvarez, P.; Bleck, W.; Gil Sevillano, J.
2007-09-01
A novel heat treatment, rapid transformation annealing (RTA) is introduced, which uses the refining effect of the phase transformation during recrystallization annealing. The RTA is comprised of rapid heating including the full or partial phase transformation of cold-rolled, nonrecrystallized, or partly recrystallized α microstructure to γ microstructure combined with subsequent rapid cooling to ambient temperature. In this way, a substantial grain refinement compared to conventional industrial annealing of cold-rolled strip can be realized. Minimum homogeneous grain sizes of 2.3 μm are produced in microalloyed high-strength low-alloy (HSLA) steels. A plain low-carbon steel shows despite any microalloying grain sizes of about 2.5 μm. Grain refinement results in a substantial increase in strength and in a pronounced strain hardening in the ΘIV stage. Simultaneously, the uniform and total elongation slightly decrease, which is a physical consequence of Considère’s instability criterion. By a refinement from 4.2 to 2.3 μm, the yield and tensile strength of a HSLA grade can be increased by about 130 MPa to 535 and 650 MPa, while the total elongation is reduced by about four percentage points to 21 pct, i.e., a still moderate formability is provided. In general, the ductility-strength relationship remains similar to the conventional behavior. For all investigated steel grades, the Hall Petch (HP) relationship is fulfilled. Furthermore, it is proved that RTA cycles can be realized in pilot scale as far as induction heating devices are applied.
NASA Astrophysics Data System (ADS)
Fritz, Gerhard; Glatter, Otto
2006-09-01
The generalized indirect Fourier transformation (GIFT) technique is a versatile tool for the evaluation of small angle scattering data. It does not depend on models for the size and shape of the particles and requires model assumptions only for the interaction effects that are typically not as sensitive to the details of the assumptions. We review here the development of the technique from its inception, focusing on the included interaction models for hard, charged and attractive spheres, and lamellae. A considerable number of applications has also been reported ranging from surfactants, emulsions, microemulsions, food science, and ceramics to melts and block-copolymers.
Gantri, M.
2014-01-01
The present paper gives a new computational framework within which radiative transfer in a varying refractive index biological tissue can be studied. In our previous works, Legendre transform was used as an innovative view to handle the angular derivative terms in the case of uniform refractive index spherical medium. In biomedical optics, our analysis can be considered as a forward problem solution in a diffuse optical tomography imaging scheme. We consider a rectangular biological tissue-like domain with spatially varying refractive index submitted to a near infrared continuous light source. Interaction of radiation with the biological material into the medium is handled by a radiative transfer model. In the studied situation, the model displays two angular redistribution terms that are treated with Legendre integral transform. The model is used to study a possible detection of abnormalities in a general biological tissue. The effect of the embedded nonhomogeneous objects on the transmitted signal is studied. Particularly, detection of targets of localized heterogeneous inclusions within the tissue is discussed. Results show that models accounting for variation of refractive index can yield useful predictions about the target and the location of abnormal inclusions within the tissue. PMID:25013454
Gu, Jian-Qiao; Eppler, C Mark; Montenegro, Gloria; Timmins, Scott D; Timmermann, Barbara N
2005-01-01
Nematicidal bioassay-guided fractionation of the n-hexane extract of the seeds of Jubaea chilensis led to the identification of eight known fatty acids and a mixture of triglycerides, reported for the first time for this species. In addition, their corresponding methyl esters were identified to be artifacts generated during the extraction and isolation procedures by using GC-EI-MS and chemical transformation methods. The fatty acid composition of the triglycerides was analyzed by GC-EI-MS and chemical transformation techniques. Among the 17 compounds, only lauric acid and myristic acid exhibited significant inhibitory effects on the movement of Caenorhabditis elegans with minimum inhibitory concentrations (MIC) of 75 microg/ml. PMID:16163824
Kulik, Tetiana V; Lipkovska, Natalia O; Barvinchenko, Valentyna M; Palyanytsya, Borys B; Kazakova, Olga A; Dudik, Olesia O; Menyhárd, Alfréd; László, Krisztina
2016-05-15
Thermochemical studies of hydroxycinnamic acid derivatives and their surface complexes are important for the pharmaceutical industry, medicine and for the development of technologies of heterogeneous biomass pyrolysis. In this study, structural and thermal transformations of caffeic acid complexes on silica surfaces were studied by UV-Vis spectroscopy, thermogravimetric analysis, temperature programmed desorption mass spectrometry (TPD MS) and quantum chemical methods. Two types of caffeic acid surface complexes are found to form through phenolic or carboxyl groups. The kinetic parameters of the chemical reactions of caffeic acid on silica surface are calculated. The mechanisms of thermal transformations of the caffeic chemisorbed surface complexes are proposed. Thermal decomposition of caffeic acid complex chemisorbed through grafted ester group proceeds via three parallel reactions, producing ketene, vinyl and acetylene derivatives of 1,2-dihydroxybenzene. Immobilization of phenolic acids on the silica surface improves greatly their thermal stability. PMID:26939077
Biochemical transformation of coals
Lin, M.S.; Premuzic, E.T.
1999-03-23
A method of biochemically transforming macromolecular compounds found in solid carbonaceous materials, such as coal is provided. The preparation of new microorganisms, metabolically weaned through challenge growth processes to biochemically transform solid carbonaceous materials at extreme temperatures, pressures, pH, salt and toxic metal concentrations is also disclosed. 7 figs.
NASA Astrophysics Data System (ADS)
Freni, Gabriele; Mannina, Giorgio
In urban drainage modelling, uncertainty analysis is of undoubted necessity. However, uncertainty analysis in urban water-quality modelling is still in its infancy and only few studies have been carried out. Therefore, several methodological aspects still need to be experienced and clarified especially regarding water quality modelling. The use of the Bayesian approach for uncertainty analysis has been stimulated by its rigorous theoretical framework and by the possibility of evaluating the impact of new knowledge on the modelling predictions. Nevertheless, the Bayesian approach relies on some restrictive hypotheses that are not present in less formal methods like the Generalised Likelihood Uncertainty Estimation (GLUE). One crucial point in the application of Bayesian method is the formulation of a likelihood function that is conditioned by the hypotheses made regarding model residuals. Statistical transformations, such as the use of Box-Cox equation, are generally used to ensure the homoscedasticity of residuals. However, this practice may affect the reliability of the analysis leading to a wrong uncertainty estimation. The present paper aims to explore the influence of the Box-Cox equation for environmental water quality models. To this end, five cases were considered one of which was the “real” residuals distributions (i.e. drawn from available data). The analysis was applied to the Nocella experimental catchment (Italy) which is an agricultural and semi-urbanised basin where two sewer systems, two wastewater treatment plants and a river reach were monitored during both dry and wet weather periods. The results show that the uncertainty estimation is greatly affected by residual transformation and a wrong assumption may also affect the evaluation of model uncertainty. The use of less formal methods always provide an overestimation of modelling uncertainty with respect to Bayesian method but such effect is reduced if a wrong assumption is made regarding the
Maercklin, N.; Bedrosian, P.A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.
2005-01-01
Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ???10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the two units coincides partly with a seismic scattering image. At 1-4 km depth the boundary is offset to the east of the AF surface trace, suggesting that at least two fault strands exist, and that slip occurred on multiple strands throughout the margin's history. A westward fault jump, possibly associated with straightening of a fault bend, explains both our observations and the narrow fault zone observed by others. Copyright 2005 by the American Geophysical Union.
Camino, Fernando E.; Nam, Chang-Yong; Pang, Yutong T.; Hoy, Jessica; Eisaman, Matthew D.; Black, Charles T.; Sfeir, Matthew Y.
2014-01-01
We present a methodology for probing light-matter interactions in prototype photovoltaic devices consisting of an organic semiconductor active layer with a semitransparent metal electrical contact exhibiting surface plasmon-based enhanced optical transmission. We achieve high-spectral irradiance in a spot size of less than 100 μm using a high-brightness laser-driven light source and appropriate coupling optics. Spatially resolved Fourier transform photocurrent spectroscopy in the visible and near-infrared spectral regions allows us to measure external quantum efficiency with high sensitivity in small-area devices (<1 mm2). This allows for rapid fabrication of variable-pitch sub-wavelength hole arrays in metal films for use as transparent electrical contacts, and evaluation of the evanescent and propagating mode coupling to resonances in the active layer. PMID:25705085
Camino, Fernando E.; Nam, Chang-Yong; Pang, Yutong T.; Hoy, Jessica; Eisaman, Matthew D.; Black, Charles T.; Sfeir, Matthew Y.
2014-05-15
Here we present a methodology for probing light-matter interactions in prototype photovoltaic devices consisting of an organic semiconductor active layer with a semitransparent metal electrical contact exhibiting surface plasmon-based enhanced optical transmission. We achieve high-spectral irradiance in a spot size of less than 100 μm using a high-brightness laser-driven light source and appropriate coupling optics. Spatially resolved Fourier transform photocurrent spectroscopy in the visible and near-infrared spectral regions allows us to measure external quantum efficiency with high sensitivity in small-area devices (<1 mm2). Lastly, this allows for rapid fabrication of variable-pitch sub-wavelength hole arrays in metal films for use asmore » transparent electrical contacts, and evaluation of the evanescent and propagating mode coupling to resonances in the active layer.« less
Camino, Fernando E.; Nam, Chang-Yong; Pang, Yutong T.; Hoy, Jessica; Eisaman, Matthew D.; Black, Charles T.; Sfeir, Matthew Y.
2014-05-15
Here we present a methodology for probing light-matter interactions in prototype photovoltaic devices consisting of an organic semiconductor active layer with a semitransparent metal electrical contact exhibiting surface plasmon-based enhanced optical transmission. We achieve high-spectral irradiance in a spot size of less than 100 μm using a high-brightness laser-driven light source and appropriate coupling optics. Spatially resolved Fourier transform photocurrent spectroscopy in the visible and near-infrared spectral regions allows us to measure external quantum efficiency with high sensitivity in small-area devices (<1 mm^{2}). Lastly, this allows for rapid fabrication of variable-pitch sub-wavelength hole arrays in metal films for use as transparent electrical contacts, and evaluation of the evanescent and propagating mode coupling to resonances in the active layer.
New X-Ray Tomography Method Based on the 3D Radon Transform Compatible with Anisotropic Sources
NASA Astrophysics Data System (ADS)
Vassholz, M.; Koberstein-Schwarz, B.; Ruhlandt, A.; Krenkel, M.; Salditt, T.
2016-02-01
In this work, we propose a novel computed tomography (CT) approach for three-dimensional (3D) object reconstruction, based on a generalized tomographic geometry with two-dimensional angular sampling (two angular degrees of freedom). The reconstruction is based on the 3D radon transform and is compatible with anisotropic beam conditions. This allows isotropic 3D imaging with a source, which can be extended along one direction for increased flux, while high resolution is achieved by a small source size only in the orthogonal direction. This novel scheme for analytical CT is demonstrated by numerical simulations and proof-of-concept experiments. In this way high resolution and coherence along a single direction determines the reconstruction quality of the entire 3D data set, opening up, for example, new opportunities to achieve nanoscale resolution and/or phase contrast with low brilliance sources such as laboratory x-ray or neutron sources.
New X-Ray Tomography Method Based on the 3D Radon Transform Compatible with Anisotropic Sources.
Vassholz, M; Koberstein-Schwarz, B; Ruhlandt, A; Krenkel, M; Salditt, T
2016-02-26
In this work, we propose a novel computed tomography (CT) approach for three-dimensional (3D) object reconstruction, based on a generalized tomographic geometry with two-dimensional angular sampling (two angular degrees of freedom). The reconstruction is based on the 3D Radon transform and is compatible with anisotropic beam conditions. This allows isotropic 3D imaging with a source, which can be extended along one direction for increased flux, while high resolution is achieved by a small source size only in the orthogonal direction. This novel scheme for analytical CT is demonstrated by numerical simulations and proof-of-concept experiments. In this way high resolution and coherence along a single direction determines the reconstruction quality of the entire 3D data set, opening up, for example, new opportunities to achieve nanoscale resolution and/or phase contrast with low brilliance sources such as laboratory x-ray or neutron sources. PMID:26967444
RECENT ADVANCES IN BARLEY TRANSFORMATION
Technology Transfer Automated Retrieval System (TEKTRAN)
Barley, an important member of the cereals, has been successfully transformed through various methods such as particle bombardment, Agrobacterium-tumefaciens, DNA uptake, and electroporation. Initially, the transformation in barley concentrated on developing protocols using marker genes such as gus,...
Trillo, Cristina; Doval, Angel F; Mendoza-Santoyo, Fernando; Pérez-López, Carlos; de la Torre-Ibarra, Manuel; Deán, J Luis
2009-09-28
The combination of a high-speed TV holography system and a 3D Fourier-transform data processing is proposed for the analysis of multimode vibrations in plates. The out-of-plane displacement of the object under generic vibrational excitation is resolved in time by the fast acquisition rate of a high-speed camera, and recorded in a sequence of interferograms with spatial carrier. A full-field temporal history of the multimode vibration is thus obtained. The optical phase of the interferograms is extracted and subtracted from the phase of a reference state to yield a sequence of optical phase-change maps. Each map represents the change undergone by the object between any given state and the reference state. The sequence of maps is a 3D array of data (two spatial dimensions plus time) that is processed with a 3D Fourier-transform algorithm. The individual vibration modes are separated in the 3D frequency space due to their different vibration frequencies and, to a lesser extent, to the different spatial frequencies of the mode shapes. The contribution of each individual mode (or indeed the superposition of several modes) to the dynamic behaviour of the object can then be separated by means of a bandpass filter (or filters). The final output is a sequence of complex-valued maps that contain the full-field temporal history of the selected mode (or modes) in terms of its mechanical amplitude and phase. The proof-of-principle of the technique is demonstrated with a rectangular, fully clamped, thin metal plate vibrating simultaneously in several of its natural resonant frequencies under white-noise excitation. PMID:19907591
Safouhi, Hassan . E-mail: hassan.safouhi@ualberta.ca; Berlu, Lilian
2006-07-20
Molecular overlap-like quantum similarity measurements imply the evaluation of overlap integrals of two molecular electronic densities related by Dirac delta function. When the electronic densities are expanded over atomic orbitals using the usual LCAO-MO approach (linear combination of atomic orbitals), overlap-like quantum similarity integrals could be expressed in terms of four-center overlap integrals. It is shown that by introducing the Fourier transform of delta Dirac function in the integrals and using the Fourier transform approach combined with the so-called B functions, one can obtain analytic expressions of the integrals under consideration. These analytic expressions involve highly oscillatory semi-infinite spherical Bessel functions, which are the principal source of severe numerical and computational difficulties. In this work, we present a highly efficient algorithm for a fast and accurate numerical evaluation of these multicenter overlap-like quantum similarity integrals over Slater type functions. This algorithm is based on the SD-bar approach due to Safouhi. Recurrence formulae are used for a better control of the degree of accuracy and for a better stability of the algorithm. The numerical result section shows the efficiency of our algorithm, compared with the alternatives using the one-center two-range expansion method, which led to very complicated analytic expressions, the epsilon algorithm and the nonlinear D-bar transformation.
Proof in Transformation Geometry
ERIC Educational Resources Information Center
Bell, A. W.
1971-01-01
The first of three articles showing how inductively-obtained results in transformation geometry may be organized into a deductive system. This article discusses two approaches to enlargement (dilatation), one using coordinates and the other using synthetic methods. (MM)
NASA Astrophysics Data System (ADS)
Espinoza-Ojeda, O. M.; Santoyo, E.
2016-08-01
A new practical method based on logarithmic transformation regressions was developed for the determination of static formation temperatures (SFTs) in geothermal, petroleum and permafrost bottomhole temperature (BHT) data sets. The new method involves the application of multiple linear and polynomial (from quadratic to eight-order) regression models to BHT and log-transformation (Tln) shut-in times. Selection of the best regression models was carried out by using four statistical criteria: (i) the coefficient of determination as a fitting quality parameter; (ii) the sum of the normalized squared residuals; (iii) the absolute extrapolation, as a dimensionless statistical parameter that enables the accuracy of each regression model to be evaluated through the extrapolation of the last temperature measured of the data set; and (iv) the deviation percentage between the measured and predicted BHT data. The best regression model was used for reproducing the thermal recovery process of the boreholes, and for the determination of the SFT. The original thermal recovery data (BHT and shut-in time) were used to demonstrate the new method's prediction efficiency. The prediction capability of the new method was additionally evaluated by using synthetic data sets where the true formation temperature (TFT) was known with accuracy. With these purposes, a comprehensive statistical analysis was carried out through the application of the well-known F-test and Student's t-test and the error percentage or statistical differences computed between the SFT estimates and the reported TFT data. After applying the new log-transformation regression method to a wide variety of geothermal, petroleum, and permafrost boreholes, it was found that the polynomial models were generally the best regression models that describe their thermal recovery processes. These fitting results suggested the use of this new method for the reliable estimation of SFT. Finally, the practical use of the new method was
Fedorischeva, Marina V. Kalashnikov, Mark P. Sergeev, Victor P.
2015-10-27
Deposition of nanostructured coatings on the basis of Zr-Y-O was implemented by the pulse magnetron methods. Structural-phase states and morphology of the nanostructured coatings were investigated by TEM, SEM and the high-temperature X-ray method. The method of the high-temperature X-ray diffraction revealed the presence of reversible phase transition of the tetragonal phase to the monoclinic phase, which can ensure stress relaxation and closure of surface cracks.
Grosjean, D. ); Tuazon, E.C. ); Fujita, E. )
1990-01-01
Formic acid is an ubiquitous component of urban smog. Sources of formic acid in urban air include direct emissions from vehicles and in situ reaction of ozone with olefins. Ambient levels of formic acid in southern California air were first measured some 15 years ago by Hanst et al. using long-path Fourier transform infrared spectroscopy (FTIR). All subsequent studies of formic acid in the Los Angeles area have involved the use of two methods, either FTIR or collection on alkaline traps followed by gas chromatography, ion chromatography, or liquid chromatography analysis with UV detection, ATLC-UV. The Carbon Species Methods Comparison Study (CSMCS), a multilaboratory air quality study carried out in August 1986 at a southern California smog receptor site, provided an opportunity for direct field comparison of the FTIR and alkaline trap methods. The results of the comparison are presented in this brief report.
ERIC Educational Resources Information Center
Reeves, Melinda
2006-01-01
The parents of students who attend Decatur High School thought that there was little hope of their kids going on to college. After a year or so in Decatur's reading program, their sons and daughters were both transformed and college bound. In this article, the author describes how Decatur was able to successfully transform their students. Seven…
Bobbitt, Jonathan M; Weibel, Stephen C; Elshobaki, Moneim; Chaudhary, Sumit; Smith, Emily A
2014-12-16
Fourier transform (FT)-plasmon waveguide resonance (PWR) spectroscopy measures light reflectivity at a waveguide interface as the incident frequency and angle are scanned. Under conditions of total internal reflection, the reflected light intensity is attenuated when the incident frequency and angle satisfy conditions for exciting surface plasmon modes in the metal as well as guided modes within the waveguide. Expanding upon the concept of two-frequency surface plasmon resonance developed by Peterlinz and Georgiadis [ Opt. Commun. 1996, 130, 260], the apparent index of refraction and the thickness of a waveguide can be measured precisely and simultaneously by FT-PWR with an average percent relative error of 0.4%. Measuring reflectivity for a range of frequencies extends the analysis to a wide variety of sample compositions and thicknesses since frequencies with the maximum attenuation can be selected to optimize the analysis. Additionally, the ability to measure reflectivity curves with both p- and s-polarized light provides anisotropic indices of refraction. FT-PWR is demonstrated using polystyrene waveguides of varying thickness, and the validity of FT-PWR measurements are verified by comparing the results to data from profilometry and atomic force microscopy (AFM).
NASA Astrophysics Data System (ADS)
Belayneh, A.; Adamowski, J.; Khalil, B.; Quilty, J.
2016-05-01
This study explored the ability of coupled machine learning models and ensemble techniques to predict drought conditions in the Awash River Basin of Ethiopia. The potential of wavelet transforms coupled with the bootstrap and boosting ensemble techniques to develop reliable artificial neural network (ANN) and support vector regression (SVR) models was explored in this study for drought prediction. Wavelet analysis was used as a pre-processing tool and was shown to improve drought predictions. The Standardized Precipitation Index (SPI) (in this case SPI 3, SPI 12 and SPI 24) is a meteorological drought index that was forecasted using the aforementioned models and these SPI values represent short and long-term drought conditions. The performances of all models were compared using RMSE, MAE, and R2. The prediction results indicated that the use of the boosting ensemble technique consistently improved the correlation between observed and predicted SPIs. In addition, the use of wavelet analysis improved the prediction results of all models. Overall, the wavelet boosting ANN (WBS-ANN) and wavelet boosting SVR (WBS-SVR) models provided better prediction results compared to the other model types evaluated.
ERIC Educational Resources Information Center
Riedinger, Kelly; Marbach-Ad, Gili; McGinnis, J. Randy; Hestness, Emily; Pease, Rebecca
2011-01-01
We investigated curricular and pedagogical innovations in an undergraduate science methods course for elementary education majors at the University of Maryland. The goals of the innovative elementary science methods course included: improving students' attitudes toward and views of science and science teaching, to model innovative science teaching…
NASA Astrophysics Data System (ADS)
Espinoza-Ojeda, O. M.; Santoyo, E.
2016-08-01
A new practical method based on logarithmic transformation regressions was developed for the determination of static formation temperatures (SFTs) in geothermal, petroleum and permafrost bottomhole temperature (BHT) data sets. The new method involves the application of multiple linear and polynomial (from quadratic to eight-order) regression models to BHT and log-transformation (Tln) shut-in times. Selection of the best regression models was carried out by using four statistical criteria: (i) the coefficient of determination as a fitting quality parameter; (ii) the sum of the normalized squared residuals; (iii) the absolute extrapolation, as a dimensionless statistical parameter that enables the accuracy of each regression model to be evaluated through the extrapolation of the last temperature measured of the data set; and (iv) the deviation percentage between the measured and predicted BHT data. The best regression model was used for reproducing the thermal recovery process of the boreholes, and for the determination of the SFT. The original thermal recovery data (BHT and shut-in time) were used to demonstrate the new method’s prediction efficiency. The prediction capability of the new method was additionally evaluated by using synthetic data sets where the true formation temperature (TFT) was known with accuracy. With these purposes, a comprehensive statistical analysis was carried out through the application of the well-known F-test and Student’s t-test and the error percentage or statistical differences computed between the SFT estimates and the reported TFT data. After applying the new log-transformation regression method to a wide variety of geothermal, petroleum, and permafrost boreholes, it was found that the polynomial models were generally the best regression models that describe their thermal recovery processes. These fitting results suggested the use of this new method for the reliable estimation of SFT. Finally, the practical use of the new method
NASA Technical Reports Server (NTRS)
Nichols, P. D.; Henson, J. M.; Guckert, J. B.; Nivens, D. E.; White, D. C.
1985-01-01
Fourier transform-infrared (FT-IR) spectroscopy has been used to rapidly and nondestructively analyze bacteria, bacteria-polymer mixtures, digester samples and microbial biofilms. Diffuse reflectance FT-IR (DRIFT) analysis of freeze-dried, powdered samples offered a means of obtaining structural information. The bacteria examined were divided into two groups. The first group was characterized by a dominant amide I band and the second group of organisms displayed an additional strong carbonyl stretch at approximately 1740 cm-1. The differences illustrated by the subtraction spectra obtained for microbes of the two groups suggest that FT-IR spectroscopy can be utilized to recognize differences in microbial community structure. Calculation of specific band ratios has enabled the composition of bacteria and extracellular or intracellular storage product polymer mixtures to be determined for bacteria-gum arabic (amide I/carbohydrate C-O approximately 1150 cm-1) and bacteria-poly-beta-hydroxybutyrate (amide I/carbonyl approximately 1740 cm-1). The key band ratios correlate with the compositions of the material and provide useful information for the application of FT-IR spectroscopy to environmental biofilm samples and for distinguishing bacteria grown under differing nutrient conditions. DRIFT spectra have been obtained for biofilms produced by Vibrio natriegens on stainless steel disks. Between 48 and 144 h, an increase in bands at approximately 1440 and 1090 cm-1 was seen in FT-IR spectra of the V. natriegens biofilm. DRIFT spectra of mixed culture effluents of anaerobic digesters show differences induced by shifts in input feedstocks. The use of flow-through attenuated total reflectance has permitted in situ real-time changes in biofilm formation to be monitored and provides a powerful tool for understanding the interactions within adherent microbial consortia.
Ciura, Franciszek . E-mail: ciura@uci.agh.edu.pl; Dubiel, Beata; Satora, Kazimierz
2006-06-15
In the Fe-30Ni alloy investigated a martensitic transformation can occur both during quenching or plastic deformation. Martensite formed during plastic deformation, depending on the thermo-mechanical treatment applied, exhibits a different morphology from that achieved during quenching and forms the so-called composite-like structure. The morphology and volume fraction of martensite depends both on strain and temperature. In the present studies Fe-30Ni alloy was deformed by monotonic rolling in one path and perpendicular rolling in the temperature range M {sub D}-M {sub S}. The aim of the investigations was a determination of martensite volume fraction depending on the strain and temperature. To examine the influence of strain, the alloy was deformed by rolling in one path or perpendicular rolling at a temperature of - 30 deg. C, in the strain range of 10-30%. The dependence of temperature was investigated by rolling with 30% strain in a temperature range from - 30 deg. C to - 80 deg. C. The variants of thermo-mechanical treatment performed enabled us to achieve different martensite morphologies and volume fractions. Microstructural analysis was performed by means of light microscopy and transmission electron microscopy. The results of quantitative microstructural analysis of martensite and retained austenite volume fractions formed in different thermo-mechanical treatments were compared with those obtained by magnetic measurements. The fraction of deformation-induced martensite determined varied from 2% to 86%. The partial volume fractions V {sub V} {sup MF} of martensite formed in different deformation directions were also determined. It was found that the influence of the temperature on the martensite volume fraction is more pronounced than the influence of strain.
Liu, Yushun; Zhou, Wenjun; Li, Pengfei; Yang, Shuai; Tian, Yan
2016-01-01
Due to electromagnetic interference in power substations, the partial discharge (PD) signals detected by ultrahigh frequency (UHF) antenna sensors often contain various background noises, which may hamper high voltage apparatus fault diagnosis and localization. This paper proposes a novel de-noising method based on the generalized S-transform and module time-frequency matrix to suppress noise in UHF PD signals. The sub-matrix maximum module value method is employed to calculate the frequencies and amplitudes of periodic narrowband noise, and suppress noise through the reverse phase cancellation technique. In addition, a singular value decomposition de-noising method is employed to suppress Gaussian white noise in UHF PD signals. Effective singular values are selected by employing the fuzzy c-means clustering method to recover the PD signals. De-noising results of simulated and field detected UHF PD signals prove the feasibility of the proposed method. Compared with four conventional de-noising methods, the results show that the proposed method can suppress background noise in the UHF PD signal effectively, with higher signal-to-noise ratio and less waveform distortion. PMID:27338409
Liu, Yushun; Zhou, Wenjun; Li, Pengfei; Yang, Shuai; Tian, Yan
2016-01-01
Due to electromagnetic interference in power substations, the partial discharge (PD) signals detected by ultrahigh frequency (UHF) antenna sensors often contain various background noises, which may hamper high voltage apparatus fault diagnosis and localization. This paper proposes a novel de-noising method based on the generalized S-transform and module time-frequency matrix to suppress noise in UHF PD signals. The sub-matrix maximum module value method is employed to calculate the frequencies and amplitudes of periodic narrowband noise, and suppress noise through the reverse phase cancellation technique. In addition, a singular value decomposition de-noising method is employed to suppress Gaussian white noise in UHF PD signals. Effective singular values are selected by employing the fuzzy c-means clustering method to recover the PD signals. De-noising results of simulated and field detected UHF PD signals prove the feasibility of the proposed method. Compared with four conventional de-noising methods, the results show that the proposed method can suppress background noise in the UHF PD signal effectively, with higher signal-to-noise ratio and less waveform distortion. PMID:27338409
NASA Astrophysics Data System (ADS)
Combet, Francois; Zimroz, Radoslaw
2009-05-01
In this paper we propose an original method for the estimation of the instantaneous speed relative fluctuation (ISRF) in a vibration signal measured on a system submitted to relatively heavy load and speed fluctuations and without speed measurement available. Our approach is based on the estimation of an instantaneous time-scaling factor along the vibration signal, related to the instantaneous relative speed gap from time t=0. It extends a previous work related to the estimation of the relative speed gap between two stationary signals via the Scale transform. In a non-stationary situation the method is performed between segments of the signal, which we coin the short time scale transform. In order to adjust the optimal length of the segments we propose an optimisation scheme based on the Kurtosis maximisation of the amplitude spectrum of the angular resampled signal using the estimated ISRF. Contrary to conventional methods based on the instantaneous frequency estimation of one spectral component, the proposed method for ISRF estimation does not depend on the choice of one particular component. The algorithm is relatively simple to implement and has a reasonable computation cost. However, it is not advised to use it in the case of very large speed variations such as during a speed-up. The method is then applied to the vibration measurements of two different planetary gearboxes used in the mining industry, first one with available speed measurement for validation, and second one with advanced wear of the planetary stage and without speed information. In this latter case the estimated ISRF is used in order to establish a diagnosis of the system.
Swallom, D.W.; Enos, G.
1990-05-01
The technical effort described in this report relates to the program that was performed to design, fabricate, and test a lightweight transformer for Strategic Defense Initiative Organization (SDIO) mission requirements. The objectives of this program were two-fold: (1) design and fabricate a lightweight transformer using liquid hydrogen as the coolant; and (2) test the completed transformer assembly with a low voltage, dc power source. Although the full power testing with liquid helium was not completed, the program demonstrated the viability of the design approach. The lightweight transformer was designed and fabricated, and low and moderate power testing was completed. The transformer is a liquid hydrogen cooled air core transformer that uses thin copper for its primary and secondary windings. The winding mass was approximately 12 kg, or 0.03 kg/kW. Further refinements of the design to a partial air core transformer could potentially reduce the winding mass to as low as 4 or 5 kg, or 0.0125 kg/kW. No attempt was made on this program to reduce the mass of the related structural components or cryogenic container. 8 refs., 39 figs., 2 tabs.
Li, Zhe; Maier, Michael P; Radke, Michael
2014-01-31
While the occurrence of pharmaceuticals in the aquatic environment has been extensively investigated, their environmental fate is less thoroughly explored. Scarce information on their transformation pathways and transformation products (TPs) limits conventional target analytical approaches. In this study, samples from water/sediment tests were analyzed by ultrahigh performance liquid chromatography interfaced with quadrupole time-of-flight mass spectrometry (UHPLC/QToF-MS). A data processing method based on peak detection, time-trend filtration and structure assignment was established to provide an efficient way for identifying the key TPs in terms of persistence; all software used for the individual steps of this method is freely available. The accurate mass and meaningful time-trends were major contributors in facilitating the isolation of plausible TP peaks. In total, 16 TPs from 9 parent pharmaceuticals were identified. Eleven out of the 16 TPs were confirmed by corresponding reference standards; no standards were available for the remaining TPs. For additional 6 potential TPs, a molecular formula was suggested but no additional structural information could be generated. Among the TPs identified in the water/sediment tests, carbamazepine-10,11-epoxide (parent: carbamazepine), saluamine (parent: furosemide), chlorothiazide and 4-amino-6-chloro-1,3-benzenedisulfonamide (parent of both: hydrochlorothiazide), and 1-naphthol (parent: propranolol) accumulated over the entire incubation period of 35 days. PMID:24439506
Gilbert, Jennifer L; Purcell, James; Strappe, Padraig; McCabe, Matthew; O'Brien, Timothy; O'Dea, Shirley
2008-09-01
Few studies have directly compared the efficiencies of gene delivery methods that target normal lung cells versus lung tumor cells. We report the first study directly comparing the efficiency and toxicity of viral [adeno-associated virus (AAV2, 5, 6) and lentivirus], nonviral (Effectene, SuperFect and Lipofectamine 2000) and physical [particle-mediated gene transfer (PMGT)] methods of gene delivery in normal mouse lung cells and in mouse adenocarcinoma cells. Lentivirus pseudotyped with the vesicular stomatitis virus glycoprotein was the most efficient gene transfer method for normal mouse airway epithelial cells [25.95 (+/-3.57) %] whereas AAV6 was most efficient for MLE-12 adenocarcinoma cells [68.2 (+/-3.2) %]. PMGT was more efficient in normal mouse airway epithelial cells than AAV5, Lipofectamine 2000 and SuperFect. AAV5 displayed the lowest transfection efficiency at less than 10% in both cell types. PMGT was the only method that resulted in significant toxicity. In summary, for all of the gene delivery methods examined here, lung tumor cells were transfected more easily than normal lung cells. Lipofectamine 2000 is potentially highly selective for lung tumor cells whereas AAV6 and lentivirus vesicular stomatitis virus glycoprotein may be useful for gene delivery strategies that require targeting of both normal and tumor cells. PMID:18690089
NASA Astrophysics Data System (ADS)
Riedinger, Kelly; Marbach-Ad, Gili; Randy McGinnis, J.; Hestness, Emily; Pease, Rebecca
2011-02-01
We investigated curricular and pedagogical innovations in an undergraduate science methods course for elementary education majors at the University of Maryland. The goals of the innovative elementary science methods course included: improving students' attitudes toward and views of science and science teaching, to model innovative science teaching methods and to encourage students to continue in teacher education. We redesigned the elementary science methods course to include aspects of informal science education. The informal science education course features included informal science educator guest speakers, a live animal demonstration and a virtual field trip. We compared data from a treatment course ( n = 72) and a comparison course ( n = 26). Data collection included: researchers' observations, instructors' reflections, and teacher candidates' feedback. Teacher candidate feedback involved interviews and results on a reliable and valid Attitudes and Beliefs about the Nature of and the Teaching of Science instrument. We used complementary methods to analyze the data collected. A key finding of the study was that while benefits were found in both types of courses, the difference in results underscores the need of identifying the primary purpose for innovation as a vital component of consideration.
Bengtsson, Henrik; Hössjer, Ola
2006-01-01
Background Low-level processing and normalization of microarray data are most important steps in microarray analysis, which have profound impact on downstream analysis. Multiple methods have been suggested to date, but it is not clear which is the best. It is therefore important to further study the different normalization methods in detail and the nature of microarray data in general. Results A methodological study of affine models for gene expression data is carried out. Focus is on two-channel comparative studies, but the findings generalize also to single- and multi-channel data. The discussion applies to spotted as well as in-situ synthesized microarray data. Existing normalization methods such as curve-fit ("lowess") normalization, parallel and perpendicular translation normalization, and quantile normalization, but also dye-swap normalization are revisited in the light of the affine model and their strengths and weaknesses are investigated in this context. As a direct result from this study, we propose a robust non-parametric multi-dimensional affine normalization method, which can be applied to any number of microarrays with any number of channels either individually or all at once. A high-quality cDNA microarray data set with spike-in controls is used to demonstrate the power of the affine model and the proposed normalization method. Conclusion We find that an affine model can explain non-linear intensity-dependent systematic effects in observed log-ratios. Affine normalization removes such artifacts for non-differentially expressed genes and assures that symmetry between negative and positive log-ratios is obtained, which is fundamental when identifying differentially expressed genes. In addition, affine normalization makes the empirical distributions in different channels more equal, which is the purpose of quantile normalization, and may also explain why dye-swap normalization works or fails. All methods are made available in the aroma package, which is
NASA Astrophysics Data System (ADS)
Dam, Tapabrata; Jena, Sidhartha S.; Pradhan, Dillip K.
2016-02-01
In this work we report the novel synthesis procedure of phase-pure nano-structured titania in anatase phase using polyacrylamide gel based polymer template method. The evolution of rutile phased titania with increasing temperature has also been investigated. The synthesized nano-materials are characterized using X-ray diffraction, Brunauer - Emmett - Teller surface analysis technique and Scanning electron microscopy. We have used dual phase Rietveld refinement method to analyse the X-Ray diffraction data to get clear picture of crystallographic information of the prepared samples.
NASA Astrophysics Data System (ADS)
Pan, Xiaolong; Liu, Bo; Li, Li; Tian, Qinghua
2016-07-01
This paper proposes and demonstrates a low complexity multiple-input multiple-output (MIMO) equalization digital signal processing (DSP) method for the few mode multi-core (FMMC) fiber optical transmission system. The MIMO equalization algorithm offers adaptive equalization taps according to the degree of crosstalk in cores or modes, which eliminates the interference among different modes and cores in space division multiplexing (SDM) transmission system. Compared with traditional MIMO method, the proposed scheme has increased the convergence rate by 4 times and reduced the number of finite impulse response (FIR) filters by 55% when the numbers of mode and core are three.
ERIC Educational Resources Information Center
Lin, Angel M. Y.
2012-01-01
Chen's book, "Asia as Method" (Duke University Press, 2010), and his theorization on topics of de-imperialization, de-colonization, de-cold war, as well as on foregrounding epistemologies and frames of reference situated in the diverse contexts in Asia have contributed to empowering scholars and researchers situated not only in Taiwan, but also in…
NASA Astrophysics Data System (ADS)
Mallah, Muhammad Ali; Sherazi, Syed Tufail Hussain; Bhanger, Muhammad Iqbal; Mahesar, Sarfaraz Ahmed; Bajeer, Muhammad Ashraf
2015-04-01
A transmission FTIR spectroscopic method was developed for direct, inexpensive and fast quantification of paracetamol content in solid pharmaceutical formulations. In this method paracetamol content is directly analyzed without solvent extraction. KBr pellets were formulated for the acquisition of FTIR spectra in transmission mode. Two chemometric models: simple Beer's law and partial least squares employed over the spectral region of 1800-1000 cm-1 for quantification of paracetamol content had a regression coefficient of (R2) of 0.999. The limits of detection and quantification using FTIR spectroscopy were 0.005 mg g-1 and 0.018 mg g-1, respectively. Study for interference was also done to check effect of the excipients. There was no significant interference from the sample matrix. The results obviously showed the sensitivity of transmission FTIR spectroscopic method for pharmaceutical analysis. This method is green in the sense that it does not require large volumes of hazardous solvents or long run times and avoids prior sample preparation.
Disc piezoelectric ceramic transformers.
Erhart, Jirií; Půlpán, Petr; Doleček, Roman; Psota, Pavel; Lédl, Vít
2013-08-01
In this contribution, we present our study on disc-shaped and homogeneously poled piezoelectric ceramic transformers working in planar-extensional vibration modes. Transformers are designed with electrodes divided into wedge, axisymmetrical ring-dot, moonie, smile, or yin-yang segments. Transformation ratio, efficiency, and input and output impedances were measured for low-power signals. Transformer efficiency and transformation ratio were measured as a function of frequency and impedance load in the secondary circuit. Optimum impedance for the maximum efficiency has been found. Maximum efficiency and no-load transformation ratio can reach almost 100% and 52 for the fundamental resonance of ring-dot transformers and 98% and 67 for the second resonance of 2-segment wedge transformers. Maximum efficiency was reached at optimum impedance, which is in the range from 500 Ω to 10 kΩ, depending on the electrode pattern and size. Fundamental vibration mode and its overtones were further studied using frequency-modulated digital holographic interferometry and by the finite element method. Complementary information has been obtained by the infrared camera visualization of surface temperature profiles at higher driving power. PMID:25004532
NASA Astrophysics Data System (ADS)
Khan, Farrukh I.; Schinn, Dustin S.
2013-08-01
A new business plan that enables policy transformation and resource mobilization at the national and international level, while improving access to resources, will allow the Green Climate Fund to integrate development goals and action on climate change.
NASA Astrophysics Data System (ADS)
Kisil, Vladimir V.
2011-03-01
Dedicated to the memory of Cora Sadosky The paper develops theory of covariant transform, which is inspired by the wavelet construction. It was observed that many interesting types of wavelets (or coherent states) arise from group representations which are not square integrable or vacuum vectors which are not admissible. Covariant transform extends an applicability of the popular wavelets construction to classic examples like the Hardy space H2, Banach spaces, covariant functional calculus and many others.
NASA Technical Reports Server (NTRS)
Lewis, Michael
1994-01-01
Statistical encoding techniques enable the reduction of the number of bits required to encode a set of symbols, and are derived from their probabilities. Huffman encoding is an example of statistical encoding that has been used for error-free data compression. The degree of compression given by Huffman encoding in this application can be improved by the use of prediction methods. These replace the set of elevations by a set of corrections that have a more advantageous probability distribution. In particular, the method of Lagrange Multipliers for minimization of the mean square error has been applied to local geometrical predictors. Using this technique, an 8-point predictor achieved about a 7 percent improvement over an existing simple triangular predictor.
Mainali, Dipak; Seelenbinder, John
2016-05-01
Quick and presumptive identification of seized drug samples without destroying evidence is necessary for law enforcement officials to control the trafficking and abuse of drugs. This work reports an automated screening method to detect the presence of cocaine in seized samples using portable Fourier transform infrared (FT-IR) spectrometers. The method is based on the identification of well-defined characteristic vibrational frequencies related to the functional group of the cocaine molecule and is fully automated through the use of an expert system. Traditionally, analysts look for key functional group bands in the infrared spectra and characterization of the molecules present is dependent on user interpretation. This implies the need for user expertise, especially in samples that likely are mixtures. As such, this approach is biased and also not suitable for non-experts. The method proposed in this work uses the well-established "center of gravity" peak picking mathematical algorithm and combines it with the conditional reporting feature in MicroLab software to provide an automated method that can be successfully employed by users with varied experience levels. The method reports the confidence level of cocaine present only when a certain number of cocaine related peaks are identified by the automated method. Unlike library search and chemometric methods that are dependent on the library database or the training set samples used to build the calibration model, the proposed method is relatively independent of adulterants and diluents present in the seized mixture. This automated method in combination with a portable FT-IR spectrometer provides law enforcement officials, criminal investigators, or forensic experts a quick field-based prescreening capability for the presence of cocaine in seized drug samples. PMID:27006022
Yang, G; Zhang, J; Gong, J; Chen, J; Ho, Y
1987-10-15
The phase mask distribution of optical sine transformation (OST) has been calculated according to the optical general transformation theory. To avoid the diffraction loss of the phase mask, the optical waveguide method is used. Computation shows that the optical sine transformation is possible with only one phase mask, i.e., one-half of a cylindrical lens in the 1-D case and one-quarter of a spherical lens in the 2-D case. Experimental results agree with the theoretical prediction. Image compression by OST is also given. PMID:20523380
Martinez, A.M.; Hollis, W.K.; Rubin, J.B.; Taylor, C.M.V.; Jasperson, M.N.; Vance, D.E.; Rodriguez, J.B.
1999-02-01
A novel approach has been developed at the Los Alamos National Laboratory for the quantitative determination of moisture content in impure plutonium oxide. The method combines a commercial supercritical fluid extraction instrument using supercritical carbon dioxide (SCCO{sub 2}) with on-line detection using a high-pressure Fourier Transform Infrared Spectroscopy (FTIR) cell. The combined SCCO{sub 2}/FTIR system has been modified for use inside a fully enclosed glove box. A series of validation experiments were performed using a pure, surrogate oxide (ThO{sub 2}) and an inorganic hydrate (CaSO{sub 4}{center_dot}2H{sub 2}O). The level of agreement between LOI and SCCO{sub 2}/FTIR for the surrogate oxide is excellent. The results for the inorganic hydrate showed excellent correlation with the known amount of water present. Results obtained for a group of nominally pure PuO{sub 2} samples were verified by independent measurement. The results of SCCO{sub 2}/FTIR for impure PuO{sub 2} samples is consistently lower than the results of obtained from the current analytical method (Loss On Ignition), indicating that the current method is inadequate for analytical purposes. While further verification experiments of the SCCO{sub 2}/FTIR method are underway, these initial results suggest that SCCO{sub 2}/FTIR could be used as an alternative analytical method for the Materials Identification and Surveillance program.
NASA Astrophysics Data System (ADS)
Galle, B.; Klemedtsson, L.; Griffith, D. W. T.
1994-08-01
Measurements of the sources and sinks of biogenic trace gases such as N2O and CH4 from terrestrial ecosystems are important in explaining and predicting the influence of these gases on global warming. Because of their biological origins the fluxes of these gases often show high spatial and temporal variation. Traditional methods of flux measurement use different types of field chambers or micrometeorologically based methods. These methods have several shortcomings and may not always be applicable to flux measurements of trace gases such as N2O or CH4. Fourier transform infrared (FTIR) spectroscopy, due to its path-integrating and multicomponent nature, shows unique potential for the measurement of fluxes of greenhouse gases from various ecosystems. To assess this potential, we have used a medium resolution (1 cm-1) FTIR spectrometer to test its suitability for area-integrated measurements, simultaneous multicomponent measurements, and continuous real-time measurements of trace gas fluxes. We have tested three different configurations: a conventional field chamber where the FTIR is used to continuously and simultaneously monitor the concentration changes of several gases, a megachamber method using a large tent as field chamber with the FTIR optical path within the chamber, and a micrometeorological flux gradient method. The three configurations are described and discussed and their performance is demonstrated in measurements of fluxes of N2O from a fertilized grassland and CH4 from a forest soil.
Unaldi, Numan; Temel, Samil; Asari, Vijayan K
2012-01-01
One of the most critical issues of Wireless Sensor Networks (WSNs) is the deployment of a limited number of sensors in order to achieve maximum coverage on a terrain. The optimal sensor deployment which enables one to minimize the consumed energy, communication time and manpower for the maintenance of the network has attracted interest with the increased number of studies conducted on the subject in the last decade. Most of the studies in the literature today are proposed for two dimensional (2D) surfaces; however, real world sensor deployments often arise on three dimensional (3D) environments. In this paper, a guided wavelet transform (WT) based deployment strategy (WTDS) for 3D terrains, in which the sensor movements are carried out within the mutation phase of the genetic algorithms (GAs) is proposed. The proposed algorithm aims to maximize the Quality of Coverage (QoC) of a WSN via deploying a limited number of sensors on a 3D surface by utilizing a probabilistic sensing model and the Bresenham's line of sight (LOS) algorithm. In addition, the method followed in this paper is novel to the literature and the performance of the proposed algorithm is compared with the Delaunay Triangulation (DT) method as well as a standard genetic algorithm based method and the results reveal that the proposed method is a more powerful and more successful method for sensor deployment on 3D terrains. PMID:22666078
NASA Astrophysics Data System (ADS)
Khieovongphachanh, Vimontha; Hamamoto, Kazuhiko; Kondo, Shozo
In this paper, we investigate optimized quantization method in JPEG2000 application for medical ultrasonic echo images. JPEG2000 has been issued as the new standard for image compression technique, which is based on Wavelet Transform (WT) and JPEG2000 incorporated into DICOM (Digital Imaging and Communications in Medicine). There are two quantization methods. One is the scalar derived quantization (SDQ), which is usually used in standard JPEG2000. The other is the scalar expounded quantization (SEQ), which can be optimized by user. Therefore, this paper is an optimization of quantization step, which is determined by Genetic Algorithm (GA). Then, the results are compared with SDQ and SEQ determined by arithmetic average method. The purpose of this paper is to improve image quality and compression ratio for medical ultrasonic echo images. The image quality is evaluated by objective assessment, PSNR (Peak Signal to Noise Ratio) and subjective assessment is evaluated by ultrasonographers from Tokai University Hospital and Tokai University Hachioji Hospital. The results show that SEQ determined by GA provides better image quality than SDQ and SEQ determined by arithmetic average method. Additionally, three optimization methods of quantization step apply to thin wire target image for analysis of point spread function.
Unaldi, Numan; Temel, Samil; Asari, Vijayan K.
2012-01-01
One of the most critical issues of Wireless Sensor Networks (WSNs) is the deployment of a limited number of sensors in order to achieve maximum coverage on a terrain. The optimal sensor deployment which enables one to minimize the consumed energy, communication time and manpower for the maintenance of the network has attracted interest with the increased number of studies conducted on the subject in the last decade. Most of the studies in the literature today are proposed for two dimensional (2D) surfaces; however, real world sensor deployments often arise on three dimensional (3D) environments. In this paper, a guided wavelet transform (WT) based deployment strategy (WTDS) for 3D terrains, in which the sensor movements are carried out within the mutation phase of the genetic algorithms (GAs) is proposed. The proposed algorithm aims to maximize the Quality of Coverage (QoC) of a WSN via deploying a limited number of sensors on a 3D surface by utilizing a probabilistic sensing model and the Bresenham's line of sight (LOS) algorithm. In addition, the method followed in this paper is novel to the literature and the performance of the proposed algorithm is compared with the Delaunay Triangulation (DT) method as well as a standard genetic algorithm based method and the results reveal that the proposed method is a more powerful and more successful method for sensor deployment on 3D terrains. PMID:22666078
Recent advances in plant transformation.
Barampuram, Shyamkumar; Zhang, Zhanyuan J
2011-01-01
Plant genetic engineering has become one of the most important molecular tools in the modern molecular breeding of crops. Over the last decade, significant progress has been made in the development of new and efficient transformation methods in plants. Despite a variety of available DNA delivery methods, Agrobacterium- and biolistic-mediated transformation remain the two predominantly employed approaches. In particular, progress in Agrobacterium-mediated transformation of cereals and other recalcitrant dicot species has been quite remarkable. In the meantime, other transgenic-enabling technologies have emerged, including generation of marker-free transgenics, gene targeting, and chromosomal engineering. Although transformation of some plant species or elite germplasm remains a challenge, further advancement in transformation technology is expected because the mechanisms of governing the regeneration and transformation processes are now better understood and are being creatively applied to designing improved transformation methods or to developing new enabling technologies. PMID:21181522
Pasto, A.E.
1975-08-01
A process for low temperature sintering of rare earth and actinide oxides which have a cubic to monoclinic transformation is described. The process involves hot pressing a powder compact at a temperature just above the transformation temperature. (auth)
NASA Astrophysics Data System (ADS)
Shi, Juanjuan; Liang, Ming; Guan, Yunpeng
2016-02-01
The conventional way for bearing fault diagnosis under variable rotational speed generally includes prefiltering, resampling based on shaft rotating frequency and order spectrum analysis. However, its application is confined by three major obstacles: a) knowledge-demanding parameter determination required by prefiltering, b) unavailable shaft rotating frequency for resampling as it is coupled with instantaneous fault characteristic frequency (IFCF) by a fault characteristic coefficient (FCC) which cannot be decided without knowing what fault actually exists, and c) complicated and error-prone resampling process. As such, we propose a new method to address these problems. The proposed method free from prefiltering and resampling mainly contains the following steps: a) extracting envelope by windowed fractal dimension (FD) transform, requiring no prefiltering, b) with the envelope signal, performing short time Fourier transform (STFT) to get a clear time frequency representation (TFR), from which the IFCF and the basic demodulator for generalized demodulation (GD) can be obtained, c) applying the generalized demodulation to the envelope signal with the current demodulator, converting the trajectory of the current time-frequency component into a linear path parallel to the time axis, d) frequency analyzing the demodulated signal, followed by searching the amplitude of the constant frequency where the linear path is situated. Updating demodulator via multiplying the basic demodulator by different real numbers (i.e., coefficient λ) and repeating the steps (c)-(d), the resampling-free order spectrum is then obtained. Based on the resulting spectrum, the final diagnosis decision can be made. The proposed method for its implementation on the example of simulated data is presented. Finally, experimental data are employed to validate the effectiveness of the proposed technique.
NASA Astrophysics Data System (ADS)
Sainath, Kamalesh; Teixeira, Fernando L.; Donderici, Burkay
2014-07-01
We propose the complex-plane generalization of a powerful algebraic sequence acceleration algorithm, the method of weighted averages (MWA), to guarantee exponential-cum-algebraic convergence of Fourier and Fourier-Hankel (F-H) integral transforms. This “complex-plane” MWA, effected via a linear-path detour in the complex plane, results in rapid, absolute convergence of field and potential solutions in multi-layered environments regardless of the source-observer geometry and anisotropy/loss of the media present. In this work, we first introduce a new integration path used to evaluate the field contribution arising from the radiation spectra. Subsequently, we (1) exhibit the foundational relations behind the complex-plane extension to a general Levin-type sequence convergence accelerator, (2) specialize this analysis to one member of the Levin transform family (the MWA), (3) address and circumvent restrictions, arising for two-dimensional integrals associated with wave dynamics problems, through minimal complex-plane detour restrictions and a novel partition of the integration domain, (4) develop and compare two formulations based on standard/real-axis MWA variants, and (5) present validation results and convergence characteristics for one of these two formulations.
Sainath, Kamalesh; Teixeira, Fernando L.; Donderici, Burkay
2014-07-15
We propose the complex-plane generalization of a powerful algebraic sequence acceleration algorithm, the method of weighted averages (MWA), to guarantee exponential-cum-algebraic convergence of Fourier and Fourier–Hankel (F–H) integral transforms. This “complex-plane” MWA, effected via a linear-path detour in the complex plane, results in rapid, absolute convergence of field and potential solutions in multi-layered environments regardless of the source-observer geometry and anisotropy/loss of the media present. In this work, we first introduce a new integration path used to evaluate the field contribution arising from the radiation spectra. Subsequently, we (1) exhibit the foundational relations behind the complex-plane extension to a general Levin-type sequence convergence accelerator, (2) specialize this analysis to one member of the Levin transform family (the MWA), (3) address and circumvent restrictions, arising for two-dimensional integrals associated with wave dynamics problems, through minimal complex-plane detour restrictions and a novel partition of the integration domain, (4) develop and compare two formulations based on standard/real-axis MWA variants, and (5) present validation results and convergence characteristics for one of these two formulations.
Orlova, Darya Y; Bártová, Eva; Maltsev, Valeri P; Kozubek, Stanislav; Chernyshev, Andrei V
2011-01-19
Determining averaged effective diffusion constants from experimental measurements of fluorescent proteins in an inhomogeneous medium in the presence of ligand-receptor interactions poses problems of analytical tractability. Here, we introduced a nonfitting method to evaluate the averaged effective diffusion coefficient of a region of interest (which may include a whole nucleus) by mathematical processing of the entire cellular two-dimensional spatial pattern of recovered fluorescence. Spatially and temporally resolved measurements of protein transport inside cells were obtained using the fluorescence recovery after photobleaching technique. Two-dimensional images of fluorescence patterns were collected by laser-scanning confocal microscopy. The method was demonstrated by applying it to an estimation of the mobility of green fluorescent protein-tagged heterochromatin protein 1 in the nuclei of living mouse embryonic fibroblasts. This approach does not require the mathematical solution of a corresponding system of diffusion-reaction equations that is typical of conventional fluorescence recovery after photobleaching data processing, and is most useful for investigating highly inhomogeneous areas, such as cell nuclei, which contain many protein foci and chromatin domains. PMID:21244847
Orlova, Darya Y.; Bártová, Eva; Maltsev, Valeri P.; Kozubek, Stanislav; Chernyshev, Andrei V.
2011-01-01
Determining averaged effective diffusion constants from experimental measurements of fluorescent proteins in an inhomogeneous medium in the presence of ligand-receptor interactions poses problems of analytical tractability. Here, we introduced a nonfitting method to evaluate the averaged effective diffusion coefficient of a region of interest (which may include a whole nucleus) by mathematical processing of the entire cellular two-dimensional spatial pattern of recovered fluorescence. Spatially and temporally resolved measurements of protein transport inside cells were obtained using the fluorescence recovery after photobleaching technique. Two-dimensional images of fluorescence patterns were collected by laser-scanning confocal microscopy. The method was demonstrated by applying it to an estimation of the mobility of green fluorescent protein-tagged heterochromatin protein 1 in the nuclei of living mouse embryonic fibroblasts. This approach does not require the mathematical solution of a corresponding system of diffusion-reaction equations that is typical of conventional fluorescence recovery after photobleaching data processing, and is most useful for investigating highly inhomogeneous areas, such as cell nuclei, which contain many protein foci and chromatin domains. PMID:21244847
Kim, H.; Ko, Y.S.; Jung, K.H. )
1992-07-01
In this paper, an expert system is developed to provide a quick and best strategy of load transfer for the power system operator. This load transferring problem is then constrained by the firm and normal capacities of a bank, the fault history of a bank, and the feeder priorities. Heuristic rules which are obtained from a substation operator and both DDC (Distribution Dispatch Center) and DDC (Distribution Control Center) engineers, are incorporated in an expert system to improve the solution procedure. Furthermore, the structural rules based on the bus topology are also generated to reduce the number of switching required to reallocate the load from the busbar connected to the faulted bank to the other sections. This expert system is implemented in Prolog, and the best-first search method is adopted. To solve the combinatorial problem, list processing and recursive programming techniques are used. We also employ the pattern matching mechanism to trace the feeder connectivity.
Yang, Xiaojuan; Post, Wilfred M
2011-01-01
In spite of the importance of phosphorus (P) as a limiting nutrient in terrestrial ecosystems, our understanding of terrestrial P dynamics and our ability to model P cycling are hampered by the lack of consistent measurements of soil P. The Hedley fractionation method provides a comprehensive assessment of soil P and has been widely used in recent decades. Here we expand an earlier study that summarized Hedley P data from the literature to create a larger Hedley P database and further investigate the relationships between distributions of different forms of P and the stages of soil development. Our expanded Hedley P database generally supports what the Walker and Syers (1976) conceptual model predicts: the gradual decrease and eventual depletion of primary mineral P (mainly apatite P); the continual increase and eventual dominance of occluded P; and the overall decrease of total P during soil development. However the analysis disagrees with Walker and Syers (1976) in that we found labile inorganic P(Pi) and secondary mineral Pi (non-occluded P in Walker and Syers model) to be a significant fraction of total P throughout all soil orders with different weathering stages. By analyzing the Hedley-labile P and vegetation P demand, we found that the amount of labile P is much greater than vegetation demand, even in highly weathered soils commonly considered P limited. We conclude that labile P measured by Hedley fractionation method should not be defined as plant available P since most of this labile P likely ends up as immobilized by microbes. Our analysis of the database also shows that carbon (C) and nitrogen (N) in soil organic matter are closely linked in all soil orders, but P is decoupled from C and N in highly weathered soils with larger variations of nitrogen:organic P (N:Po) ratio and higher mean values of N:Po ratio, compared to slightly and intermediately weathered soils.
NASA Astrophysics Data System (ADS)
Zacharioudaki, Maria; Kouris, Charalampos; Dimakopoulos, Yannis; Tsamopoulos, John
2007-12-01
A Volume Tracking (VT) and a Front Tracking (FT) algorithm are implemented and compared for locating the interface between two immiscible, incompressible, Newtonian fluids in a tube with a periodically varying, circular cross-section. Initially, the fluids are stationary and stratified in an axisymmetric arrangement so that one is around the axis of the tube (core fluid) and the other one surrounds it (annular fluid). A constant pressure gradient sets them in motion. With both VT and FT, a boundary-fitted coordinate transformation is applied and appropriate modifications are made to adopt either method in this geometry. The surface tension force is approximated using the continuous surface force method. All terms appearing in the continuity and momentum equations are approximated using centered finite differences in space and one-sided forward finite differences in time. In each time step, the incompressibility condition is enforced by a transformed Poisson equation, which is linear in pressure. This equation is solved by either direct LU decomposition or a Multigrid iterative solver. When the two fluids have the same density, the former method is about 3.5 times faster, but when they do not, the Multigrid solver is as much as 10 times faster than the LU decomposition. When the interface does not break and the Reynolds number remains small, the accuracy and rates of convergence of VT and FT are comparable. The well-known failure of centered finite differences arises as the Reynolds number increases and leads to non-physical oscillations in the interface and failure of both methods to converge with mesh refinement. These problems are resolved and computations with Reynolds as large as 500 converged by approximating the convective terms in the momentum equations by third-order upwind differences using Lagrangian Polynomials. When the volume of the core fluid or the Weber number decrease, increasing the importance of interfacial tension and leading to breakup of the
NASA Astrophysics Data System (ADS)
Shebeko, A.
2013-12-01
The clothing procedure, put forward in quantum field theory by Greenberg and Schweber, is applied for the description of nucleon-nucleon ( N- N) scattering below the pion production threshold and deuteron properties. We consider pseudoscalar ( π and η), vector ( ρ and ω) and scalar ( δ and σ) meson fields interacting with N and ones via the Yukawa-type couplings to introduce trial interactions between "bare" particles. The subsequent unitary clothing transformations (UCTs) are found to express the total Hamiltonian through new interaction operators that refer to particles with physical (observable) properties, the so-called clothed particles. The corresponding analytic expressions in momentum space are compared with the separate meson contributions to the one-boson-exchange potentials in the meson theory of nuclear forces. We will also show a worked example where the UCTs method is used in the framework of a gauge-independent field-theoretical treatment of electromagnetic interactions of deuterons (bound systems).
NASA Astrophysics Data System (ADS)
Homel, Michael A.; Guilkey, James E.; Brannon, Rebecca M.
2015-10-01
A new approach is presented for computing the return in numerical solutions for computational plasticity models that ensures convergence through bisection of the plastic consistency parameter, while using a transformed-space closest-point return based on a geometric search that eliminates the need to compute gradients of the yield function or a consistent tangent operator. Numerical solution of the governing equations for computational plasticity is highly-nontrivial for complex constitutive laws. In particular for geomaterials, a predictive model may account for nonlinear elasticity, shear strength that depends nonlinearly on pressure and Lode angle, and nonlinear evolution models for internal variables such as porosity or pore pressure. Traditional gradient-based integration methods may perform poorly when the hardening laws are highly nonlinear or when the yield function has an ill-defined or cumbersome gradient because of high curvature, vertices, or complicated functional form. The application of this new approach to geomaterial modeling is described, along with verification benchmarks.
NASA Astrophysics Data System (ADS)
Wyatt, Stephan
2004-08-01
The U.S. Navy"s SHAred Reconnaissance Pod (SHARP) employs the Recon/Optical, Inc. (ROI) CA-279 dual spectral band (visible/IR) digital cameras operating from an F-18E/F aircraft to perform low-to-high altitude reconnaissance missions. SHARP has proven itself combat worthy, with a rapid transition from development to operational deployment culminating in a highly reliable and effective reconnaissance capability for joint forces operating in Operation Iraqi Freedom (OIF). The U.S. Navy"s intelligence, surveillance and reconnaissance (ISR) roadmap transforms the SHARP system from being solely an independent reconnaissance sensor to a node in the growing Joint ISR network. ROI and the U.S. Navy have combined their resources to ensure the system"s transformation continues to follow the ISR road map. Pre-planned product improvements (P3I) for the CA-270 camera systems will lead the way in that transformation.
NASA Astrophysics Data System (ADS)
Yu, Hwa-Lung; Lin, Yuan-Chien
2015-06-01
Rainfall-groundwater interactions are complex and can depend upon a variety of hydro-geological and geographical conditions and can commonly present high nonlinearity. This study proposed an integration of cross wavelet transform and empirical orthogonal function (EOF) analysis to analyze the space-time nonlinear relationships between the precipitation and groundwater changes. The proposed method was applied to investigating the non-stationary and nonlinear precipitation-groundwater relationships in Pingtung Plain aquifer during 2005-2010. We analyzed daily groundwater and rainfall observations at 47 wells and 27 stations across the study area operated by Taiwan Water Resources Agency and Central Weather Bureau respectively. Results show that EOF method revealed three major space-time patterns of the groundwater levels. The cross wavelet transform further identified the lagged effects between precipitation and groundwater changes. The temporal lags can vary not only with respect to the temporal scales of groundwater processes, but also the different identified groundwater regions, which can associate with distinct physical mechanisms. In general, the lagged periods between high frequency signals of precipitation and groundwater can range from 0 to 18 days, showing how rainfall events perturbed the groundwater levels across space. The long-term lags for the three identified underlying groundwater processes were 3.71, 56.6, and 72.07 days, respectively, showing seasonal recharge patterns can depend upon the geographical and geological conditions. Our results distinguished the space-time recharge processes in different frequencies, which present nonlinear and non-stationary rainfall-recharge interactions of a groundwater system, which can be spatially and frequency dependent.
NASA Astrophysics Data System (ADS)
Ilhan, I.; Coakley, B. J.
2013-12-01
The Chukchi Edges project was designed to establish the relationship between the Chukchi Shelf and Borderland and indirectly test theories of opening for the Canada Basin. During this cruise, ~5300 km of 2D multi-channel reflection seismic profiles and other geophysical data (swath bathymetry, gravity, magnetics, sonobuoy refraction seismic) were collected from the RV Marcus G. Langseth across the transition between the Chukchi Shelf and Chukchi Borderland, where the water depths vary from 30 m to over 3 km. Multiples occur when seismic energy is trapped in a layer and reflected from an acoustic interface more than once. Various kinds of multiples occur during seismic data acquisition. These depend on the ray-path the seismic energy follows through the layers. One of the most common multiples is the surface related multiple, which occurs due to strong acoustic impedance contrast between the air and water. The reflected seismic energy from the water surface is trapped within the water column, thus reflects from the seafloor multiple times. Multiples overprint the primary reflections and complicate data interpretation. Both surface related multiple elimination (SRME) and forward parabolic radon transform multiple modeling methods were necessary to attenuate the multiples. SRME is applied to shot gathers starting with the near offset interpolation, multiple estimation using water depths, and subtracting the model multiple from the shot gathers. This method attenuated surface related multiple energy, however, peg-leg multiples remained in the data. The parabolic radon transform method minimized the effect of these multiples. This method is applied to normal moveout (NMO) corrected common mid-point gathers (CMP). The CMP gathers are fitted or modeled with curves estimated from the reference offset, moveout range, moveout increment parameters. Then, the modeled multiples are subtracted from the data. Preliminary outputs of these two methods show that the surface related
Floral Transformation of Wheat
NASA Astrophysics Data System (ADS)
Agarwal, Sujata; Loar, Star; Steber, Camille; Zale, Janice
A method is described for the floral transformation of wheat using a protocol similar to the floral dip of Arabidopsis. This method does not employ tissue culture of dissected embryos, but instead pre-anthesis spikes with clipped florets at the early, mid to late uninucleate microspore stage are dipped in Agrobacterium infiltration media harboring a vector carrying anthocyanin reporters and the NPTII selectable marker. T1 seeds are examined for color changes induced in the embryo by the anthocyanin reporters. Putatively transformed seeds are germinated and the seedlings are screened for the presence of the NPTII gene based on resistance to paromomycin spray and assayed with NPTII ELISAs. Genomic DNA of putative transformants is digested and analyzed on Southern blots for copy number to determine whether the T-DNA has integrated into the nucleus and to show the number of insertions. The non-optimized transformation efficiencies range from 0.3 to 0.6% (number of transformants/number of florets dipped) but the efficiencies are higher in terms of the number of transformants produced/number of seeds set ranging from 0.9 to 10%. Research is underway to maximize seed set and optimize the protocol by testing different Agrobacterium strains, visual reporters, vectors, and surfactants.
Beaunier, L.; Frydman, J.; Gabrielli, C.; Huet, F.; Keddam, M.
1996-12-31
A comparison of a spectral analysis using the fast Fourier transform (FFT) and the maximum entropy method (MEM) was carried out in the case in which both methods can be performed, that is, when several time acquisitions can be recorded. A summary of the principles of the MEM is given. Then the main properties of this method are investigated, that is, influence of the MEM order on the spectrum accuracy, validity of the low-frequency plateau usually given by this technique, overlapping of spectra measured for different frequency bandwidths, and influence of a slow evolution of the amplitude of the signal fluctuations. The susceptibility to pitting corrosion of type 304 stainless steel and type 304 modified by molybdenum (Mo) by means of ion implantation was studied. The power spectral densities (PSD) measured with the FFT and MEM techniques are in reasonable agreement, except for low electrochemical current noises (ECN) buried in the parasitic noise generated by the power supply. In that case, the FFT technique is more appropriate than the MEM, which gave qualitative results only. The type 304 stainless steel showed a large metastable pitting leading to only a few macroscopic pits, whereas the type 304 Mo-implanted specimen showed a very low metastable pitting leading to many hemispheric pits covered by the Mo-implanted layer, under which localized corrosion occurred.
NASA Astrophysics Data System (ADS)
Jeong, Hyeok Jae; Lim, Nam Suk; Lee, Bong Ho; Park, Chan Gyung; Lee, Sunghak; Kang, Seong-Hoon; Lee, Ho Won; Kim, Hyoung Seop
2014-12-01
Transformation-induced plasticity (TRIP) steels have excellent strain hardening exponents and resistibility against tensile necking using the strain-induced martensite formation that occurs as a result of the plastic deformation and strain on the retained austenite phase. Detailed studies on the microstructures and local mechanical properties, as well as global mechanical properties, are necessary in order to thoroughly understand the properties of TRIP steels with multiple phases of ferrite, bainite, retained austenite, and martensite. However, methods for investigating the local properties of the various phases of the TRIP steel are limited due to the very complicated and fine microstructures present in TRIP steel. In this study, the experimental and numerical methods, i.e., the experimental nanoindenting results and the theoretical finite element analyses, were combined in order to extract the local stress-strain curves of each phase. The local stress-strain curves were in good agreement with the values presented in the literature. In particular, the global plastic stress-strain behavior of the TRIP steel was predicted using the multiple phase unit cell finite element analysis, and this demonstrated the validity of the obtained properties of each local phase. The method of extracting the local stress-strain curves from the nanoindenting curves and predicting the global stress-strain behavior assists in clarifying the smart design of multi-phase steels.
NASA Astrophysics Data System (ADS)
Jeong, Hyeok Jae; Lim, Nam Suk; Lee, Bong Ho; Park, Chan Gyung; Lee, Sunghak; Kang, Seong-Hoon; Lee, Ho Won; Kim, Hyoung Seop
2014-09-01
Transformation-induced plasticity (TRIP) steels have excellent strain hardening exponents and resistibility against tensile necking using the strain-induced martensite formation that occurs as a result of the plastic deformation and strain on the retained austenite phase. Detailed studies on the microstructures and local mechanical properties, as well as global mechanical properties, are necessary in order to thoroughly understand the properties of TRIP steels with multiple phases of ferrite, bainite, retained austenite, and martensite. However, methods for investigating the local properties of the various phases of the TRIP steel are limited due to the very complicated and fine microstructures present in TRIP steel. In this study, the experimental and numerical methods, i.e., the experimental nanoindenting results and the theoretical finite element analyses, were combined in order to extract the local stress-strain curves of each phase. The local stress-strain curves were in good agreement with the values presented in the literature. In particular, the global plastic stress-strain behavior of the TRIP steel was predicted using the multiple phase unit cell finite element analysis, and this demonstrated the validity of the obtained properties of each local phase. The method of extracting the local stress-strain curves from the nanoindenting curves and predicting the global stress-strain behavior assists in clarifying the smart design of multi-phase steels.
Aburai, Kenichi; Ogura, Taku; Hyodo, Ryo; Sakai, Hideki; Abe, Masahiko; Glatter, Otto
2013-01-01
We investigated the location of cholesterol (Chol) in liposomes and its interaction with phospholipids using small-angle x-ray scattering (SAXS) data and applying the generalized indirect Fourier transformation (GIFT) method. The GIFT method has been applied to lamellar liquid crystal systems and it gives quantitative data on bilayer thickness, electron density profile, and membrane flexibility (Caillé parameter). When the GIFT method is applied to the SAXS data of dipalmitoylphosphatidylcholine (DPPC) alone (Chol [-]) or a DPPC/Chol = 7/3 mixed system (Chol [+], molar ratio), change in the bilayer thickness was insignificant in both systems. However, the electron density for the Chol (+) system was higher than that for the Chol (-) system at the location of hydrophilic groups of phospholipids, and whereas Caillé parameter value increased with temperature for the Chol (-) system, no significant change with temperature was observed in the Caillé parameter for the Chol (+) system. These results indicated that Chol is located in the vicinity of the hydrophilic group of the phospholipids and constricts the packing of the acyl chain of phospholipids in the bilayer. PMID:24200939
ERIC Educational Resources Information Center
Berry, John N., III
2007-01-01
The program for the march by librarians on America's capital for the American Library Association (ALA) conference is predictably loaded with lobbying, legislation, and DC tours. It also abounds with professional opportunity and reflects the impact of Leslie Burger, one of the most activist ALA presidents in recent history. Her "Transformation"…
Transformation & Metamorphosis
ERIC Educational Resources Information Center
Lott, Debra
2009-01-01
The sculptures of Canadian artist Brian Jungen are a great inspiration for a lesson on creating new forms. Jungen transforms found objects into unique creations without fully concealing their original form or purpose. Frank Stella's sculpture series, including "K.132,2007" made of stainless steel and spray paint, is another great example of…
ERIC Educational Resources Information Center
Cookson, Peter W., Jr., Ed.; Schneider, Barbara, Ed.
The authors in this book address the issues that relate to the crisis in American education and review some of the proposed solutions. To transform education, schools must be examined as social systems that are interrelated with families, communities, and the world of work. Following the introduction, section 1, "Conditions for Educational…
NASA Astrophysics Data System (ADS)
Wilson, Robin; Milton, Edward; Nield, Joanna
2016-04-01
Aerosol Optical Thickness (AOT) data has many important applications including atmospheric correction of satellite imagery and monitoring of particulate matter air pollution. Current data products are generally available at a kilometre-scale resolution, but many applications require far higher resolutions. For example, particulate matter concentrations vary on a metre-scale, and thus data products at a similar scale are required to provide accurate assessments of particle densities and allow effective monitoring of air quality and analysis of local air quality effects on health. A novel method has been developed which retrieves per-pixel AOT values from high-resolution (~30m) satellite data. This method is designed to work over a wide range of land covers - including both bright and dark surfaces - and requires only standard visible and near-infrared data, making it applicable to a range of data from sensors such as Landsat, SPOT and Sentinel-2. The method is based upon an extension of the Haze Optimized Transform (HOT). The HOT was originally designed for assessing areas of thick haze in satellite imagery by calculating a 'haziness' value for each pixel in an image as the distance from a 'Clear Line' in feature space, defined by the high correlation between visible bands. Here, we adapt the HOT method and use it to provide AOT data instead. Significant extensions include Monte Carlo estimation of the 'Clear Line', object-based correction for land cover, and estimation of AOT from the haziness values through radiative transfer modelling. This novel method will enable many new applications of AOT data that were impossible with previously available low-resolution data, and has the potential to contribute significantly to our understanding of the air quality on health, the accuracy of satellite image atmospheric correction and the role of aerosols in the climate system.
Smith, Rebecca; Najarian, Kayvan; Ward, Kevin
2009-01-01
Background Traumatic pelvic injuries are often associated with severe, life-threatening hemorrhage, and immediate medical treatment is therefore vital. However, patient prognosis depends heavily on the type, location and severity of the bone fracture, and the complexity of the pelvic structure presents diagnostic challenges. Automated fracture detection from initial patient X-ray images can assist physicians in rapid diagnosis and treatment, and a first and crucial step of such a method is to segment key bone structures within the pelvis; these structures can then be analyzed for specific fracture characteristics. Active Shape Model has been applied for this task in other bone structures but requires manual initialization by the user. This paper describes a algorithm for automatic initialization and segmentation of key pelvic structures - the iliac crests, pelvic ring, left and right pubis and femurs - using a hierarchical approach that combines directed Hough transform and Active Shape Models. Results Performance of the automated algorithm is compared with results obtained via manual initialization. An error measures is calculated based on the shapes detected with each method and the gold standard shapes. ANOVA results on these error measures show that the automated algorithm performs at least as well as the manual method. Visual inspection by two radiologists and one trauma surgeon also indicates generally accurate performance. Conclusion The hierarchical algorithm described in this paper automatically detects and segments key structures from pelvic X-rays. Unlike various other x-ray segmentation methods, it does not require manual initialization or input. Moreover, it handles the inconsistencies between x-ray images in a clinical environment and performs successfully in the presence of fracture. This method and the segmentation results provide a valuable base for future work in fracture detection. PMID:19891796
Kawato, M; Isobe, M; Maeda, Y; Suzuki, R
1988-01-01
In order to control visually-guided voluntary movements, the central nervous system (CNS) must solve the following three computational problems at different levels: (1) determination of a desired trajectory in the visual coordinates, (2) transformation of the coordinates of the desired trajectory to the body coordinates and (3) generation of motor command. In this paper, the second and the third problems are treated at computational, representational and hardware levels of Marr. We first study the problems at the computational level, and then propose an iterative learning scheme as a possible algorithm. This is a trial and error type learning such as repetitive training of golf swing. The amount of motor command needed to coordinate activities of many muscles is not determined at once, but in a step-wise, trial and error fashion in the course of a set of repetitions. Actually, the motor command in the (n + 1)-th iteration is a sum of the motor command in the n-th iteration plus two modification terms which are, respectively, proportional to acceleration and speed errors between the desired trajectory and the realized trajectory in the n-th iteration. We mathematically formulate this iterative learning control as a Newton-like method in functional spaces and prove its convergence under appropriate mathematical conditions with use of dynamical system theory and functional analysis. Computer simulations of this iterative learning control of a robotic manipulator in the body or visual coordinates are shown. Finally, we propose that areas 2, 5, and 7 of the sensory association cortex are possible sites of this learning control. Further we propose neural network model which acquires transformation matrices from acceleration or velocity to motor command, which are used in these schemes. PMID:3179342
NASA Astrophysics Data System (ADS)
Romanova, Vanya; Hense, Andreas
2015-04-01
In our study we use the anomaly transform, a special case of ensemble transform method, in which a selected set of initial oceanic anomalies in space, time and variables are defined and orthogonalized. The resulting orthogonal perturbation patterns are designed such that they pick up typical balanced anomaly structures in space and time and between variables. The metric used to set up the eigen problem is taken either as the weighted total energy with its zonal, meridional kinetic and available potential energy terms having equal contributions, or the weighted ocean heat content in which a disturbance is applied only to the initial temperature fields. The choices of a reference state for defining the initial anomalies are such that either perturbations on seasonal timescales and or on interannual timescales are constructed. These project a-priori only the slow modes of the ocean physical processes, such that the disturbances grow mainly in the Western Boundary Currents, in the Antarctic Circumpolar Current and the El Nino Southern Oscillation regions. An additional set of initial conditions is designed to fit in a least square sense data from global ocean reanalysis. Applying the AT produced sets of disturbances to oceanic initial conditions initialized by observations of the MPIOM-ESM coupled model on T63L47/GR15 resolution, four ensemble and one hind-cast experiments were performed. The weighted total energy norm is used to monitor the amplitudes and rates of the fastest growing error modes. The results showed minor dependence of the instabilities or error growth on the selected metric but considerable change due to the magnitude of the scaling amplitudes of the perturbation patterns. In contrast to similar atmospheric applications, we find an energy conversion from kinetic to available potential energy, which suggests a different source of uncertainty generation in the ocean than in the atmosphere mainly associated with changes in the density field.
Plastid transformation in soybean.
Dubald, Manuel; Tissot, Ghislaine; Pelissier, Bernard
2014-01-01
The biotechnological potential of plastid genetic engineering has been illustrated in a limited number of higher plant species. We have developed a reproducible method to generate plastid transformants in soybean (Glycine max), a crop of major agronomic importance. The transformation vectors are delivered to embryogenic cultures by the particle gun method and selection performed using the aadA antibiotic resistance gene. Homoplasmy is established rapidly in the selected events without the need for further selection or regeneration cycles, and genes of interest can be expressed at a high level in green tissues. This is a significant step toward the commercial application of this technology. PMID:24599865
Data compression by wavelet transforms
NASA Technical Reports Server (NTRS)
Shahshahani, M.
1992-01-01
A wavelet transform algorithm is applied to image compression. It is observed that the algorithm does not suffer from the blockiness characteristic of the DCT-based algorithms at compression ratios exceeding 25:1, but the edges do not appear as sharp as they do with the latter method. Some suggestions for the improved performance of the wavelet transform method are presented.
Improved transformer-winding method
NASA Technical Reports Server (NTRS)
Mclyman, W. T.
1978-01-01
Proposed technique using special bobbin and fixture to wind copper wire directly on core eliminates need core cut prior to assembly. Application of technique could result in production of quieter core with increased permeability and no localized heating.
Thomas, M.J. . E-mail: m.j.thomas@sheffield.ac.uk; Wynne, B.P.; Rainforth, W.M.
2005-11-15
An alternative technique to that recently put forward by Germain et al. [Materials Characterization 54 (2005) 216-222] to separate the orientations of primary alpha ({alpha}{sub p}) grains from those of transformed beta ({alpha}{sub s}) grains in the near-{alpha} titanium alloy Timetal 834 is presented. This new method involves correlating orientation image maps (OIM) obtained through electron back-scattered diffraction (EBSD) with optical images of the same area. By using optical microscopy and an appropriate etch, strong contrast between {alpha}{sub p} and {alpha}{sub s} is obtained enabling regions within an OIM containing the {alpha}{sub p} and {alpha}{sub s} to be determined using relatively straightforward image analysis. Results are presented for both high-resolution microstructure analysis and texture level EBSD datasets for material subjected to a simulated industrial thermomechanical forging process. A comparison is also made between the texture datasets for both {alpha}{sub p} and {alpha}{sub s} obtained using this method and that obtained using grain size distribution acquired directly from the EBSD dataset. In this case very little difference was found between the separated textures, suggesting that in the first instance a morphological/grain size approach direct from the EBSD dataset is sufficient for observing any trends in texture evolution of both {alpha}{sub p} and {alpha}{sub s}.
NASA Astrophysics Data System (ADS)
Wu, T. Y.; Lin, S. F.
2013-10-01
Automatic suspected lesion extraction is an important application in computer-aided diagnosis (CAD). In this paper, we propose a method to automatically extract the suspected parotid regions for clinical evaluation in head and neck CT images. The suspected lesion tissues in low contrast tissue regions can be localized with feature-based segmentation (FBS) based on local texture features, and can be delineated with accuracy by modified active contour models (ACM). At first, stationary wavelet transform (SWT) is introduced. The derived wavelet coefficients are applied to derive the local features for FBS, and to generate enhanced energy maps for ACM computation. Geometric shape features (GSFs) are proposed to analyze each soft tissue region segmented by FBS; the regions with higher similarity GSFs with the lesions are extracted and the information is also applied as the initial conditions for fine delineation computation. Consequently, the suspected lesions can be automatically localized and accurately delineated for aiding clinical diagnosis. The performance of the proposed method is evaluated by comparing with the results outlined by clinical experts. The experiments on 20 pathological CT data sets show that the true-positive (TP) rate on recognizing parotid lesions is about 94%, and the dimension accuracy of delineation results can also approach over 93%.
Yu, Yifei; Luo, Linqing; Li, Bo; Guo, Linfeng; Yan, Jize; Soga, Kenichi
2015-10-01
The measured distance error caused by double peaks in the BOTDRs (Brillouin optical time domain reflectometers) system is a kind of Brillouin scattering spectrum (BSS) deformation, discussed and simulated for the first time in the paper, to the best of the authors' knowledge. Double peak, as a kind of Brillouin spectrum deformation, is important in the enhancement of spatial resolution, measurement accuracy, and crack detection. Due to the variances of the peak powers of the BSS along the fiber, the measured starting point of a step-shape frequency transition region is shifted and results in distance errors. Zero-padded short-time-Fourier-transform (STFT) can restore the transition-induced double peaks in the asymmetric and deformed BSS, thus offering more accurate and quicker measurements than the conventional Lorentz-fitting method. The recovering method based on the double-peak detection and corresponding BSS deformation can be applied to calculate the real starting point, which can improve the distance accuracy of the STFT-based BOTDR system. PMID:26479653
Smith, James L.; Helenberg, Harold W.; Kilsdonk, Dennis J.
1979-01-01
There is provided an improved RF transformer having a single-turn secondary of cylindrical shape and a coiled encapsulated primary contained within the secondary. The coil is tapered so that the narrowest separation between the primary and the secondary is at one end of the coil. The encapsulated primary is removable from the secondary so that a variety of different capacity primaries can be utilized with one secondary.
Focus On: Transforming Relationships.
ERIC Educational Resources Information Center
Karal, Pearl; And Others
1985-01-01
Karal describes the psychodynamics by which children learn to fear and distrust long-term commitments. Vaines proposes a conceptualization of the home economist as transforming actor. LeBow addresses methods of treating obese youth. Fewster and Kuhonta offer insights on communicating with Third World rural women. (SK)
Improved Transformation of Anthurium
Technology Transfer Automated Retrieval System (TEKTRAN)
Methods to increase transformation efficiency and yields of transgenic Anthurium andraeanum Linden ex. André hybrids were sought while effecting gene transfer for resistance to the two most important pests, bacterial blight (Xanthomonas axonopodis pv. dieffenbachiae) and nematodes (Radopholus simili...
Rahman, Ziyaur; Siddiqui, Akhtar; Bykadi, Srikant; Khan, Mansoor A
2014-08-01
The objective of the present research was to study the feasibility of using near-infrared (NIR) and Fourier transform infrared (FTIR)-based chemometric models in quantifying crystalline and amorphous tacrolimus from its sustained-release amorphous solid dispersion (ASD). ASD contained ethyl cellulose, hydroxypropyl methyl cellulose, and lactose monohydrate as carriers, and amorphous form of tacrolimus in it was confirmed by X-ray powder diffraction. Crystalline physical mixture was mixed with ASD in various proportions to prepare sample matrices containing 0%-100% amorphous/crystalline tacrolimus. NIR and FTIR of the samples were recorded, and data were mathematically pretreated using multiple scattering correction, standard normal variate, or Savitzky-Golay before multivariate analysis, partial-least-square regression (PLSR), and principle component regression (PCR). The PLSR models were more accurate than PCR for NIR and FTIR data as indicated by low value of root-mean-squared error of prediction, standard error of prediction and bias, and high value of R(2). Additionally, NIR data-based models were more accurate and precise than FTIR data models. In conclusion, NIR chemometric models provide simple and fast method to quantitate crystalline tacrolimus in the ASD formulation. PMID:24931728
NASA Astrophysics Data System (ADS)
Kong, Weiwei; Lei, Yang; Zhao, Huaixun
2014-11-01
The issue of visible light and infrared images fusion has been an active topic in both military and civilian areas, and a great many relevant algorithms and techniques have been developed accordingly. This paper addresses a novel adaptive approach to the above two patterns of images fusion problem, employing multi-scale geometry analysis (MGA) of non-subsampled shearlet transform (NSST) and fast non-negative matrix factorization (FNMF) together. Compared with other existing conventional MGA tools, NSST owns not only better feature-capturing capabilities, but also much lower computational complexities. As a modification version of the classic NMF model, FNMF overcomes the local optimum property inherent in NMF to a large extent. Furthermore, use of the FNMF with a less complex structure and much fewer iteration numbers required leads to the enhancement of the overall computational efficiency, which is undoubtedly meaningful and promising in so many real-time applications especially the military and medical technologies. Experimental results indicate that the proposed method is superior to other current popular ones in both aspects of subjective visual and objective performance.
NASA Astrophysics Data System (ADS)
Usher, P. D.
1997-12-01
William Shakespeare's Hamlet has much evidence to suggest that the Bard was aware of the cosmological models of his time, specifically the geocentric bounded Ptolemaic and Tychonic models, and the infinite Diggesian. Moreover, Shakespeare describes how the Ptolemaic model is to be transformed to the Diggesian. Hamlet's "transformation" is the reason that Claudius, who personifies the Ptolemaic model, summons Rosencrantz and Guildenstern, who personify the Tychonic. Pantometria, written by Leonard Digges and his son Thomas in 1571, contains the first technical use of the word "transformation." At age thirty, Thomas Digges went on to propose his Perfit Description, as alluded to in Act Five where Hamlet's age is given as thirty. In Act Five as well, the words "bore" and "arms" refer to Thomas' vocation as muster-master and his scientific interest in ballistics. England's leading astronomer was also the father of the poet whose encomium introduced the First Folio of 1623. His oldest child Dudley became a member of the Virginia Company and facilitated the writing of The Tempest. Taken as a whole, such manifold connections to Thomas Digges support Hotson's contention that Shakespeare knew the Digges family. Rosencrantz and Guildenstern in Hamlet bear Danish names because they personify the Danish model, while the king's name is latinized like that of Claudius Ptolemaeus. The reason Shakespeare anglicized "Amleth" to "Hamlet" was because he saw a parallel between Book Three of Saxo Grammaticus and the eventual triumph of the Diggesian model. But Shakespeare eschewed Book Four, creating this particular ending from an infinity of other possibilities because it "suited his purpose," viz. to celebrate the concept of a boundless universe of stars like the Sun.
Wolfgang, F.; Nicol, J.
1962-11-01
Transformer apparatus is designed for measuring the amount of a paramagnetic substance dissolved or suspended in a diamagnetic liquid. The apparatus consists of a cluster of tubes, some of which are closed and have sealed within the diamagnetic substance without any of the paramagnetic material. The remaining tubes are open to flow of the mix- ture. Primary and secondary conductors are wrapped around the tubes in such a way as to cancel noise components and also to produce a differential signal on the secondaries based upon variations of the content of the paramagnetic material. (AEC)
NASA Technical Reports Server (NTRS)
McLyman, Colonel Wm. T.
1996-01-01
None given. From first Par: Many spacecraft (S/C) and surface rovers require the transfer of signals and power across rotating interfaces. Science instruments, antennas and solar arrays are elements needing rotary power transfer for certain (S/C) configurations. Delivery of signal and power has mainly been done by using the simplest means, the slip ring approach. This approach, although simple, leaves debris generating noise over a period of time...The rotary transformer is a good alternative to slip rings for signal and power transfer.
Moffat, A.S.
1990-08-10
Researchers have produced fertile corn transformed with a foreign gene that makes the plants resistant to the herbicide bialaphos. This achievement, is the first report of fertile transgenic corn in the reviewed literature, and it is the capstone of almost a decade's efforts to genetically engineer this country's most important crop. The only other major crop to be so manipulated is rice. The ability produce transgenic corn gives biologists a valuable tool to probe the whys and hows of gene expression and regulation. It may also give plant breeders a way to develop new corn varieties with a speed and predictability that would be impossible with classical breeding techniques.
Marlow, D L
1996-01-01
In these uncertain times in the healthcare industry, administrators are asked to do more with less time and resources. Because of the extended roles they are playing in today's organizations, radiology administrators are looked upon as agents of change. What leadership skills do they need in this turbulent and uncertain healthcare environment? What are the trait's of tomorrow's leaders? The transformational leader is the one who will guide us through this changing healthcare environment. Several behavioral patterns emerge as important traits for tomorrow's leaders to have-individual consideration, intellectual stimulation and charisma. Tomorrow's leader must view each person as an individual, showing genuine concern and belief in each person's ability to perform. Transformational leaders stimulate others by encouraging them to be curious and try new ideas. The final characteristic, charisma, is the ability to inspire others. Luckily, leaders are made, not born: today's leaders can learn to be responsive, to draw out new ideas from employees, and to communicate self-esteem, energy and enthusiasm. PMID:10163135
Balsera, Mónica; Arellano, Juan B; Gutiérrez, José R; Heredia, Pedro; Revuelta, José L; De Las Rivas, Javier
2003-02-01
The structure of PsbQ, one of the three main extrinsic proteins associated with the oxygen-evolving complex (OEC) of higher plants and green algae, is examined by Fourier transform infrared (FTIR) and circular dichroic (CD) spectroscopy and by computational structural prediction methods. This protein, together with two other lumenally bound extrinsic proteins, PsbO and PsbP, is essential for the stability and full activity of the OEC in plants. The FTIR spectra obtained in both H(2)O and D(2)O suggest a mainly alpha-helix structure on the basis of the relative areas of the constituents of the amide I and I' bands. The FTIR quantitative analyses indicate that PsbQ contains about 53% alpha-helix, 7% turns, 14% nonordered structure, and 24% beta-strand plus other beta-type extended structures. CD analyses indicate that PsbQ is a mainly alpha-helix protein (about 64%), presenting a small percentage assigned to beta-strand ( approximately 7%) and a larger amount assigned to turns and nonregular structures ( approximately 29%). Independent of the spectroscopic analyses, computational methods for protein structure prediction of PsbQ were utilized. First, a multiple alignment of 12 sequences of PsbQ was obtained after an extensive search in the public databases for protein and EST sequences. Based on this alignment, computational prediction of the secondary structure and the solvent accessibility suggest the presence of two different structural domains in PsbQ: a major C-terminal domain containing four alpha-helices and a minor N-terminal domain with a poorly defined secondary structure enriched in proline and glycine residues. The search for PsbQ analogues by fold recognition methods, not based on the secondary structure, also indicates that PsbQ is a four alpha-helix protein, most probably folding as an up-down bundle. The results obtained by both the spectroscopic and computational methods are in agreement, all indicating that PsbQ is mainly an alpha protein, and show
Elliptic systems and numerical transformations
NASA Technical Reports Server (NTRS)
Mastin, C. W.; Thompson, J. F.
1976-01-01
Properties of a transformation method, which was developed for solving fluid dynamic problems on general two dimensional regions, are discussed. These include construction error of the transformation and applications to mesh generation. An error and stability analysis for the numerical solution of a model parabolic problem is also presented.
The ABB transformer monitoring system
Claiborne, C.; Gorman, M.; Petrie, E.M.
1996-03-01
ABB is currently developing a transformer monitoring system that will continuously perform multiple gas-in-oil and partial discharge analyses. The new monitoring system is designed to be simple and reliable. It can be applied to new units or easily retrofitted to existing transformers. The parameters that are monitored are those that are most commonly evaluated when diagnosing the condition of a power transformer. A multiple gas monitor can selectively detect and measure hydrogen, carbon monoxide, and the combination of methane and ethane. The partial discharge monitor employs an electrical method to detect partial discharges that originate from sources only within the transformer. Prototype systems will be field tested in 1995.
Lanzilotta, R. P.; Pramer, David
1970-01-01
A strain of Fusarium solani isolated from soil by enrichment techniques used propanil (3′, 4′-dichloropropionanilide) as a sole source of organic carbon and energy for growth in pure culture. The primary product of the transformation of propanil by F. solani was isolated and identified as 3,4-dichloroaniline (DCA). This compound accumulated in the medium to a level (80 μg/ml) which stopped further herbicide utilization. Herbicide utilization by F. solani was influenced by various environmental and nutritional factors. It was more sensitive to acid than alkaline pH. Added glucose and yeast extract increased the rate of propanil decomposition, and the reduced aeration retarded growth of the fungus and herbicide utilization. The growth of F. solani on propionate was inhibited by added DCA. Images PMID:5437305
NASA Astrophysics Data System (ADS)
Paton-Walsh, C.; Smith, T. E. L.; Young, E. L.; Griffith, D. W. T.; Guérette, É.-A.
2014-10-01
Biomass burning releases trace gases and aerosol particles that significantly affect the composition and chemistry of the atmosphere. Australia contributes approximately 8% of gross global carbon emissions from biomass burning, yet there are few previous measurements of emissions from Australian forest fires available in the literature. This paper describes the results of field measurements of trace gases emitted during hazard reduction burns in Australian temperate forests using open-path Fourier transform infrared spectroscopy. In a companion paper, similar techniques are used to characterise the emissions from hazard reduction burns in the savanna regions of the Northern Territory. Details of the experimental methods are explained, including both the measurement set-up and the analysis techniques employed. The advantages and disadvantages of different ways to estimate whole-fire emission factors are discussed and a measurement uncertainty budget is developed. Emission factors for Australian temperate forest fires are measured locally for the first time for many trace gases. Where ecosystem-relevant data are required, we recommend the following emission factors for Australian temperate forest fires (in grams of gas emitted per kilogram of dry fuel burned) which are our mean measured values: 1620 ± 160 g kg-1 of carbon dioxide; 120 ± 20 g kg-1 of carbon monoxide; 3.6 ± 1.1 g kg-1 of methane; 1.3 ± 0.3 g kg-1 of ethylene; 1.7 ± 0.4 g kg-1 of formaldehyde; 2.4 ± 1.2 g kg-1 of methanol; 3.8 ± 1.3 g kg-1 of acetic acid; 0.4 ± 0.2 g kg-1 of formic acid; 1.6 ± 0.6 g kg-1 of ammonia; 0.15 ± 0.09 g kg-1 of nitrous oxide and 0.5 ± 0.2 g kg-1 of ethane.
NASA Technical Reports Server (NTRS)
Marko, H.
1978-01-01
A general spectral transformation is proposed and described. Its spectrum can be interpreted as a Fourier spectrum or a Laplace spectrum. The laws and functions of the method are discussed in comparison with the known transformations, and a sample application is shown.
Computing Instantaneous Frequency by normalizing Hilbert Transform
Huang, Norden E.
2005-05-31
This invention presents Normalized Amplitude Hilbert Transform (NAHT) and Normalized Hilbert Transform(NHT), both of which are new methods for computing Instantaneous Frequency. This method is designed specifically to circumvent the limitation set by the Bedorsian and Nuttal Theorems, and to provide a sharp local measure of error when the quadrature and the Hilbert Transform do not agree. Motivation for this method is that straightforward application of the Hilbert Transform followed by taking the derivative of the phase-angle as the Instantaneous Frequency (IF) leads to a common mistake made up to this date. In order to make the Hilbert Transform method work, the data has to obey certain restrictions.
Computing Instantaneous Frequency by normalizing Hilbert Transform
NASA Technical Reports Server (NTRS)
Huang, Norden E. (Inventor)
2005-01-01
This invention presents Normalized Amplitude Hilbert Transform (NAHT) and Normalized Hilbert Transform(NHT), both of which are new methods for computing Instantaneous Frequency. This method is designed specifically to circumvent the limitation set by the Bedorsian and Nuttal Theorems, and to provide a sharp local measure of error when the quadrature and the Hilbert Transform do not agree. Motivation for this method is that straightforward application of the Hilbert Transform followed by taking the derivative of the phase-angle as the Instantaneous Frequency (IF) leads to a common mistake made up to this date. In order to make the Hilbert Transform method work, the data has to obey certain restrictions.
NASA Astrophysics Data System (ADS)
Geminale, A.; Grassi, D.; Altieri, F.; Serventi, G.; Carli, C.; Carrozzo, F. G.; Sgavetti, M.; Orosei, R.; D'Aversa, E.; Bellucci, G.; Frigeri, A.
2015-06-01
The aim of this work is to extract the surface contribution in the martian visible/near-infrared spectra removing the atmospheric components by means of Principal Component Analysis (PCA) and target transformation (TT). The developed technique is suitable for separating spectral components in a data set large enough to enable an effective usage of statistical methods, in support to the more common approaches to remove the gaseous component. In this context, a key role is played by the estimation, from the spectral population, of the covariance matrix that describes the statistical correlation of the signal among different points in the spectrum. As a general rule, the covariance matrix becomes more and more meaningful increasing the size of initial population, justifying therefore the importance of sizable datasets. Data collected by imaging spectrometers, such as the OMEGA (Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité) instrument on board the ESA mission Mars Express (MEx), are particularly suitable for this purpose since it includes in the same session of observation a large number of spectra with different content of aerosols, gases and mineralogy. The methodology presented in this work has been first validated using a simulated dataset of spectra to evaluate its accuracy. Then, it has been applied to the analysis of OMEGA sessions over Nili Fossae and Mawrth Vallis regions, which have been already widely studied because of the presence of hydrated minerals. These minerals are key components of the surface to investigate the presence of liquid water flowing on the martian surface in the Noachian period. Moreover, since a correction for the atmospheric aerosols (dust) component is also applied to these observations, the present work is able to completely remove the atmospheric contribution from the analysed spectra. Once the surface reflectance, free from atmospheric contributions, has been obtained, the Modified Gaussian Model (MGM) has
NASA Astrophysics Data System (ADS)
Takeuchi, T.; Banno, N.; Fukuzaki, T.; Wada, H.
2000-10-01
The bcc supersaturated solid solution Nb(Al)ss obtained by rapid heating and quenching of a multifilamentary Nb/Al composite wire has shown a crystal structure change from a disordered to an ordered structure before transforming to the A15 Nb3Al phase. Such ordering of the bcc phase seems to be responsible for the A15 phase stacking faults that depress the critical temperature (Tc), the upper critical magnetic field (Bc2) and, hence, the critical current density (Jc) of Nb3Al in high fields. A heat treatment around 1000 °C, higher than conventional transformation temperatures by about 200 °C, suppresses the ordering and yields a new phenomenon termed the `transformation-heat-based up-quenching' (TRUQ). TRUQ is characterized by the self-heating of the bcc phase by the transformation heat, which propagates through the whole length of a composite wire and transforms it to Nb3Al. A subsequent annealing at 800 °C enhances the long-range ordering of the Nb3Al phase and drastically improves the high-field critical current densities of the Nb3Al conductors.
ERIC Educational Resources Information Center
Alsop, Steve; Dippo, Don; Zandvliet, David B.
2007-01-01
This paper offers reflections on two transformative teacher education projects. The first a global communities module is set in a university in Vancouver and utilizes the lens of social ecology to examine the roles of teachers in bringing an awareness of local/global issues to their students' learning experiences. The second, a Canadian…
General linear chirplet transform
NASA Astrophysics Data System (ADS)
Yu, Gang; Zhou, Yiqi
2016-03-01
Time-frequency (TF) analysis (TFA) method is an effective tool to characterize the time-varying feature of a signal, which has drawn many attentions in a fairly long period. With the development of TFA, many advanced methods are proposed, which can provide more precise TF results. However, some restrictions are introduced inevitably. In this paper, we introduce a novel TFA method, termed as general linear chirplet transform (GLCT), which can overcome some limitations existed in current TFA methods. In numerical and experimental validations, by comparing with current TFA methods, some advantages of GLCT are demonstrated, which consist of well-characterizing the signal of multi-component with distinct non-linear features, being independent to the mathematical model and initial TFA method, allowing for the reconstruction of the interested component, and being non-sensitivity to noise.
The Houdini Transformation: True, but Illusory
Bentler, Peter M.; Molenaar, Peter C. M.
2012-01-01
Molenaar (2003, 2011) showed that a common factor model could be transformed into an equivalent model without factors, involving only observed variables and residual errors. He called this invertible transformation the Houdini transformation. His derivation involved concepts from time series and state space theory. This paper verifies the Houdini transformation on a general latent variable model using algebraic methods. The results show that the Houdini transformation is illusory, in the sense that the Houdini transformed model remains a latent variable model. Contrary to common knowledge, a model that is a path model with only observed variables and residual errors may, in fact, be a latent variable model. PMID:23180888
The Houdini Transformation: True, but Illusory.
Bentler, Peter M; Molenaar, Peter C M
2012-01-01
Molenaar (2003, 2011) showed that a common factor model could be transformed into an equivalent model without factors, involving only observed variables and residual errors. He called this invertible transformation the Houdini transformation. His derivation involved concepts from time series and state space theory. This paper verifies the Houdini transformation on a general latent variable model using algebraic methods. The results show that the Houdini transformation is illusory, in the sense that the Houdini transformed model remains a latent variable model. Contrary to common knowledge, a model that is a path model with only observed variables and residual errors may, in fact, be a latent variable model. PMID:23180888
Inversion and approximation of Laplace transforms
NASA Technical Reports Server (NTRS)
Lear, W. M.
1980-01-01
A method of inverting Laplace transforms by using a set of orthonormal functions is reported. As a byproduct of the inversion, approximation of complicated Laplace transforms by a transform with a series of simple poles along the left half plane real axis is shown. The inversion and approximation process is simple enough to be put on a programmable hand calculator.
Transform coding for space applications
NASA Technical Reports Server (NTRS)
Glover, Daniel
1993-01-01
Data compression coding requirements for aerospace applications differ somewhat from the compression requirements for entertainment systems. On the one hand, entertainment applications are bit rate driven with the goal of getting the best quality possible with a given bandwidth. Science applications are quality driven with the goal of getting the lowest bit rate for a given level of reconstruction quality. In the past, the required quality level has been nothing less than perfect allowing only the use of lossless compression methods (if that). With the advent of better, faster, cheaper missions, an opportunity has arisen for lossy data compression methods to find a use in science applications as requirements for perfect quality reconstruction runs into cost constraints. This paper presents a review of the data compression problem from the space application perspective. Transform coding techniques are described and some simple, integer transforms are presented. The application of these transforms to space-based data compression problems is discussed. Integer transforms have an advantage over conventional transforms in computational complexity. Space applications are different from broadcast or entertainment in that it is desirable to have a simple encoder (in space) and tolerate a more complicated decoder (on the ground) rather than vice versa. Energy compaction with new transforms are compared with the Walsh-Hadamard (WHT), Discrete Cosine (DCT), and Integer Cosine (ICT) transforms.
NASA Astrophysics Data System (ADS)
Ubierna Lopez, N.; Cambaliza, M. L.; Griffith, D. W.; Mount, G. H.; Cousins, A. B.
2011-12-01
Worldwide, biosphere-atmosphere carbon exchange and net ecosystem exchange (NEE) are determined using eddy-covariance methods. Information from isotopic CO2 measurements provides valuable constraints to partition NEE into its component fluxes. Stable isotope measurements have traditionally been constrained in frequency by the need to collect and analyze field samples in a laboratory using isotope ratio mass spectrometry (MS). New techniques based on absorption spectroscopy allow for high temporal sampling resolution in the field, but with concerns about precision and accuracy of the isotope-ratios. We tested two absorption spectroscopy systems, a Fourier transformed infrared analyzer (FTIR, Vector 22, Bruker Optics, Ettlingen, Germany) and a tunable diode laser absorption spectrometer (TDLAS, model TGA 100, Campbell Scientific, Inc. Logan, UT, USA), by comparing them with continuous-flow MS (Delta plus XP IRMS, ThermoFinnigan, Bremen, Germany). We conducted a laboratory comparison of gases mixed with various CO2 concentrations and isotopic signatures as well as field-collected samples. The mixed tanks were balanced in ultra-zero air with CO2 concentrations ranging from 353 to 553 ppm, and isotopic compositions (δ13C) between -11.7% to -39.3%. The field samples were collected at four different locations (forest, wheat field, dairy farm, and paper mill) by pumping ambient air into 44- L tanks. Gas from each sample tank was simultaneously delivered to the FTIR and TDLAS systems and subsequently analyzed with continuous-flow MS. The [CO2] determined with the TDLAS or FTIR differed by <1 ppm for CO2-tanks and <2.4 ppm for ambient air samples. The δ13C offset of the CO2 tanks between the MS and the TDLAS and FTIR were on average 0.1% and 0.3%, respectively. However, the offset in TDLAS δ13C values increased for ambient air samples to values of 0.4%, with a maximum of 0.9% for the dairy farm and paper mill samples. Ambient air samples analyzed with the FTIR were on
On the use of the Stockwell transform for image compression
NASA Astrophysics Data System (ADS)
Wang, Yanwei; Orchard, Jeff
2009-02-01
In this paper, we investigate the use of the Stockwell Transform for image compression. The proposed technique uses the Discrete Orthogonal Stockwell Transform (DOST), an orthogonal version of the Discrete Stockwell Transform (DST). These mathematical transforms provide a multiresolution spatial-frequency representation of a signal or image. First, we give a brief introduction for the Stockwell transform and the DOST. Then we outline a simplistic compression method based on setting the smallest coefficients to zero. In an experiment, we use this compression strategy on three different transforms: the Fast Fourier transform, the Daubechies wavelet transform and the DOST. The results show that the DOST outperforms the two other methods.
Heat storage in alloy transformations
NASA Technical Reports Server (NTRS)
Birchenall, C. E.; Gueceri, S. I.; Farkas, D.; Labdon, M. B.; Nagaswami, N.; Pregger, B.
1981-01-01
The feasibility of using metal alloys as thermal energy storage media was determined. The following major elements were studied: (1) identification of congruently transforming alloys and thermochemical property measurements; (2) development of a precise and convenient method for measuring volume change during phase transformation and thermal expansion coefficients; (3) development of a numerical modeling routine for calculating heat flow in cylindrical heat exchangers containing phase change materials; and (4) identification of materials that could be used to contain the metal alloys. Several eutectic alloys and ternary intermetallic phases were determined. A method employing X-ray absorption techniques was developed to determine the coefficients of thermal expansion of both the solid and liquid phases and the volume change during phase transformation from data obtained during one continuous experimental test. The method and apparatus are discussed and the experimental results are presented. The development of the numerical modeling method is presented and results are discussed for both salt and metal alloy phase change media.
Nakajima, Yuya; Seino, Junji; Nakai, Hiromi
2016-05-10
An analytical energy gradient for the spin-dependent general Hartree-Fock method based on the infinite-order Douglas-Kroll-Hess (IODKH) method was developed. To treat realistic systems, the local unitary transformation (LUT) scheme was employed both in energy and energy gradient calculations. The present energy gradient method was numerically assessed to investigate the accuracy in several diatomic molecules containing fifth- and sixth-period elements and to examine the efficiency in one-, two-, and three-dimensional silver clusters. To arrive at a practical calculation, we also determined the geometrical parameters of fac-tris(2-phenylpyridine)iridium and investigated the efficiency. The numerical results confirmed that the present method describes a highly accurate relativistic effect with high efficiency. The present method can be a powerful scheme for determining geometries of large molecules, including heavy-element atoms. PMID:27045757
Virtual Enterprise: Transforming Entrepreneurship Education
ERIC Educational Resources Information Center
Borgese, Anthony
2011-01-01
Entrepreneurship education is ripe for utilizing experiential learning methods. Experiential methods are best learned when there is constant immersion into the subject matter. One such transformative learning methodology is Virtual Enterprise (VE). Virtual Enterprise is a multi-faceted, experiential learning methodology disseminated by the City…
NASA Astrophysics Data System (ADS)
1999-09-01
launch of the new Institute for Learning and Teaching in York. This has been established with the aim of raising standards of teaching in higher education and improving learning and teaching methods in universities and colleges. Teaching is felt to be at least as important as research in higher education, and the new Institute will oversee the quality of training programmes for higher education teachers, highlight examples of good practice throughout the UK, as well as recognize and reward good teaching. It will also help to administer teaching and learning support schemes on behalf of the Higher Education Funding Council for England, including a new #1m a year fund for national teaching fellowships. The Institute has been set up in response to recommendations in the Dearing Report on higher education, and will be an independent body supported by the teaching organisations, universities and colleges of higher education and the funding councils. Besides accrediting programmes of training and development, it will provide a range of services for members. Membership will be open to those engaged in teaching or learning support who have completed accredited training programmes or provided other evidence of eligibility. It is expected that membership of the institute will become a normal requirement for new teachers in higher education. Further information about the Institute may be obtained from the Institute for Learning and Teaching, Genesis 3, York Science Park, York YO10 5DQ (tel: 01904 434222, e-mail: enquiries@ilt.ac.uk).
Discrete Fourier transforms of nonuniformly spaced data
NASA Technical Reports Server (NTRS)
Swan, P. R.
1982-01-01
Time series or spatial series of measurements taken with nonuniform spacings have failed to yield fully to analysis using the Discrete Fourier Transform (DFT). This is due to the fact that the formal DFT is the convolution of the transform of the signal with the transform of the nonuniform spacings. Two original methods are presented for deconvolving such transforms for signals containing significant noise. The first method solves a set of linear equations relating the observed data to values defined at uniform grid points, and then obtains the desired transform as the DFT of the uniform interpolates. The second method solves a set of linear equations relating the real and imaginary components of the formal DFT directly to those of the desired transform. The results of numerical experiments with noisy data are presented in order to demonstrate the capabilities and limitations of the methods.
Transform approach to electromagnetic scattering
NASA Technical Reports Server (NTRS)
Mittra, R.; Ko, W. L.; Rahmat-Samii, Y.
1979-01-01
In this paper, a comprehensive review of the Fourier transform technique as applied to the problem of high-frequency scattering is presented and the concepts of the spectral theory of diffraction (STD) are introduced. In contrast to the more commonly employed ray-optical method for high-frequency scattering, the STD approach interprets the scattered field as the spectrum, or the Fourier transform of the induced current on the scatterer. Such an interpretation offers several important advantages: uniform nature of representation, capacity to improve and extend the ray-optical formulas in a systematic manner, and convenient accuracy tests for the results. Methods for combining integral equation methods with the Galerkin procedure and asymptotic techniques in the transform domain are described, and representative examples illustrating the application of the spectral approach are included.
Hough transform search for continuous gravitational waves
Krishnan, Badri; Papa, Maria Alessandra; Sintes, Alicia M.; Schutz, Bernard F.; Frasca, Sergio; Palomba, Cristiano
2004-10-15
This paper describes an incoherent method to search for continuous gravitational waves based on the Hough transform, a well-known technique used for detecting patterns in digital images. We apply the Hough transform to detect patterns in the time-frequency plane of the data produced by an earth-based gravitational wave detector. Two different flavors of searches will be considered, depending on the type of input to the Hough transform: either Fourier transforms of the detector data or the output of a coherent matched-filtering type search. We present the technical details for implementing the Hough transform algorithm for both kinds of searches, their statistical properties, and their sensitivities.
NASA Astrophysics Data System (ADS)
Sokolov, Victor; Frank, George; Kolyakov, Sergei; Afanasyeva, Natalia; Bruch, Reinhard; Artujschenko, Slava
1998-05-01
Fiber Optic Evanescent Wave Fourier Transform Infrared (FEW-FTIR) spectroscopy using ultra sensitive fiber probes with low losses in the attenuated total reflection (ATR) regime in the middle infrared (MIR) region of the spectrum (850-1800 cm-1) was used for noninvasive and rapid (seconds) direct measurements of the spectra of normal and pathological breast tissue in vitro, ex vivo and in vivo. The aim of our studies is to perform accurate testing of tumor tissue at the early stages of their development. We have tested very small human samples (about 1mm) of normal and malignant tissue with fiber tip probes. As the first step we have performed a few experiments to optimize the fiber bending angle. In addition we are constructing and testing changeable tip probes for biopsy applications. Furthermore we are designing and creating needle probes for minimally invasive biopsy and fluid examinations.
Transforming the Way We Teach Function Transformations
ERIC Educational Resources Information Center
Faulkenberry, Eileen Durand; Faulkenberry, Thomas J.
2010-01-01
In this article, the authors discuss "function," a well-defined rule that relates inputs to outputs. They have found that by using the input-output definition of "function," they can examine transformations of functions simply by looking at changes to input or output and the respective changes to the graph. Applying transformations to the input…
Symplectic wavelet transformation.
Fan, Hong-Yi; Lu, Hai-Liang
2006-12-01
Usually a wavelet transform is based on dilated-translated wavelets. We propose a symplectic-transformed-translated wavelet family psi(*)(r,s)(z-kappa) (r,s are the symplectic transform parameters, |s|(2)-|r|(2)=1, kappa is a translation parameter) generated from the mother wavelet psi and the corresponding wavelet transformation W(psi)f(r,s;kappa)=integral(infinity)(-infinity)(d(2)z/pi)f(z)psi(*)(r,s)(z-kappa). This new transform possesses well-behaved properties and is related to the optical Fresnel transform in quantum mechanical version. PMID:17099740
NASA Astrophysics Data System (ADS)
Cottura, M.; Appolaire, B.; Finel, A.; Le Bouar, Y.
2016-09-01
A phase field model is coupled to strain gradient crystal plasticity based on dislocation densities. The resulting model includes anisotropic plasticity and the size-dependence of plastic activity, required when plasticity is confined in region below few microns in size. These two features are important for handling microstructure evolutions during diffusive phase transformations that involve plastic deformation occurring in confined areas such as Ni-based superalloys undergoing rafting. The model also uses a storage-recovery law for the evolution of the dislocation density of each glide system and a hardening matrix to account for the short-range interactions between dislocations. First, it is shown that the unstable modes during the morphological destabilization of a growing misfitting circular precipitate are selected by the anisotropy of plasticity. Then, the rafting of γ‧ precipitates in a Ni-based superalloy is investigated during [100] creep loadings. Our model includes most of the important physical phenomena accounted for during the microstructure evolution, such as the presence of different crystallographic γ‧ variants, their misfit with the γ matrix, the elastic inhomogeneity and anisotropy, the hardening, anisotropy and viscosity of plasticity. In agreement with experiments, the model predicts that rafting proceeds perpendicularly to the tensile loading axis and it is shown that plasticity slows down significantly the evolution of the rafts.