Novel Random Mutagenesis Method for Directed Evolution.

Science.gov (United States)

Feng, Hong; Wang, Hai-Yan; Zhao, Hong-Yan

2017-01-01

Directed evolution is a powerful strategy for gene mutagenesis, and has been used for protein engineering both in scientific research and in the biotechnology industry. The routine method for directed evolution was developed by Stemmer in 1994 (Stemmer, Proc Natl Acad Sci USA 91, 10747-10751, 1994; Stemmer, Nature 370, 389-391, 1994). Since then, various methods have been introduced, each of which has advantages and limitations depending upon the targeted genes and procedure. In this chapter, a novel alternative directed evolution method which combines mutagenesis PCR with dITP and fragmentation by endonuclease V is described. The kanamycin resistance gene is used as a reporter gene to verify the novel method for directed evolution. This method for directed evolution has been demonstrated to be efficient, reproducible, and easy to manipulate in practice.

Direct comparison of enzyme histochemical and immunohistochemical methods to localize an enzyme

NARCIS (Netherlands)

van Noorden, Cornelis J. F.

2002-01-01

Immunohistochemical localization of enzymes is compared directly with localization of enzyme activity with (catalytic) enzyme histochemical methods. The two approaches demonstrate principally different aspects of an enzyme. The immunohistochemical method localizes the enzyme protein whether it is

Application of Patterson-function direct methods to materials characterization.

Science.gov (United States)

Rius, Jordi

2014-09-01

The aim of this article is a general description of the so-called Patterson-function direct methods (PFDM), from their origin to their present state. It covers a 20-year period of methodological contributions to crystal structure solution, most of them published in Acta Crystallographica Section A. The common feature of these variants of direct methods is the introduction of the experimental intensities in the form of the Fourier coefficients of origin-free Patterson-type functions, which allows the active use of both strong and weak reflections. The different optimization algorithms are discussed and their performances compared. This review focuses not only on those PFDM applications related to powder diffraction data but also on some recent results obtained with electron diffraction tomography data.

Application of Patterson-function direct methods to materials characterization

Directory of Open Access Journals (Sweden)

Jordi Rius

2014-09-01

Full Text Available The aim of this article is a general description of the so-called Patterson-function direct methods (PFDM, from their origin to their present state. It covers a 20-year period of methodological contributions to crystal structure solution, most of them published in Acta Crystallographica Section A. The common feature of these variants of direct methods is the introduction of the experimental intensities in the form of the Fourier coefficients of origin-free Patterson-type functions, which allows the active use of both strong and weak reflections. The different optimization algorithms are discussed and their performances compared. This review focuses not only on those PFDM applications related to powder diffraction data but also on some recent results obtained with electron diffraction tomography data.

Directed forgetting: Comparing pictures and words.

Science.gov (United States)

Quinlan, Chelsea K; Taylor, Tracy L; Fawcett, Jonathan M

2010-03-01

The authors investigated directed forgetting as a function of the stimulus type (picture, word) presented at study and test. In an item-method directed forgetting task, study items were presented 1 at a time, each followed with equal probability by an instruction to remember or forget. Participants exhibited greater yes-no recognition of remember than forget items for each of the 4 study-test conditions (picture-picture, picture-word, word-word, word-picture). However, this difference was significantly smaller when pictures were studied than when words were studied. This finding demonstrates that the magnitude of the directed forgetting effect can be reduced by high item memorability, such as when the picture superiority effect is operating. This suggests caution in using pictures at study when the goal of an experiment is to examine potential group differences in the magnitude of the directed forgetting effect. 2010 APA, all rights reserved.

Direct methods of soil-structure interaction analysis for earthquake loadings

International Nuclear Information System (INIS)

Yun, J. B.; Kim, J. M.; Kim, Y. S. and others

1993-07-01

The objectives of this study are to review the methods of soil- structure interaction system analysis, particularly the direct method, and to carry out the blind prediction analysis of the Forced Vibration Test(FVT) before backfill in the course of Hualien LSST project. The scope and contents of this study are as follows : theoretical review on soil-structure interaction analysis methods, free-field response analysis methods, modelling methods of unbounded exterior region, hualien LSST FVT blind prediction analysis before backfill. The analysis results are found to be very well compared with the field test results

A comparison of photographic, replication and direct clinical examination methods for detecting developmental defects of enamel

Directory of Open Access Journals (Sweden)

Pakshir Hamid-Reza

2011-04-01

Full Text Available Abstract Background Different methods have been used for detecting developmental defects of enamel (DDE. This study aimed to compare photographic and replication methods with the direct clinical examination method for detecting DDE in children's permanent incisors. Methods 110 8-10-year-old schoolchildren were randomly selected from an examined sample of 335 primary Shiraz school children. Modified DDE index was used in all three methods. Direct examinations were conducted by two calibrated examiners using flat oral mirrors and tongue blades. Photographs were taken using a digital SLR camera (Nikon D-80, macro lens, macro flashes, and matt flash filters. Impressions were taken using additional-curing silicon material and casts made in orthodontic stone. Impressions and models were both assessed using dental loupes (magnification=x3.5. Each photograph/impression/cast was assessed by two calibrated examiners. Reliability of methods was assessed using kappa agreement tests. Kappa agreement, McNemar's and two-sample proportion tests were used to compare results obtained by the photographic and replication methods with those obtained by the direct examination method. Results Of the 110 invited children, 90 were photographed and 73 had impressions taken. The photographic method had higher reliability levels than the other two methods, and compared to the direct clinical examination detected significantly more subjects with DDE (P = 0.002, 3.1 times more DDE (P Conclusion The photographic method was much more sensitive than direct clinical examination in detecting DDE and was the best of the three methods for epidemiological studies. The replication method provided less information about DDE compared to photography. Results of this study have implications for both epidemiological and detailed clinical studies on DDE.

Cut Based Method for Comparing Complex Networks.

Science.gov (United States)

Liu, Qun; Dong, Zhishan; Wang, En

2018-03-23

Revealing the underlying similarity of various complex networks has become both a popular and interdisciplinary topic, with a plethora of relevant application domains. The essence of the similarity here is that network features of the same network type are highly similar, while the features of different kinds of networks present low similarity. In this paper, we introduce and explore a new method for comparing various complex networks based on the cut distance. We show correspondence between the cut distance and the similarity of two networks. This correspondence allows us to consider a broad range of complex networks and explicitly compare various networks with high accuracy. Various machine learning technologies such as genetic algorithms, nearest neighbor classification, and model selection are employed during the comparison process. Our cut method is shown to be suited for comparisons of undirected networks and directed networks, as well as weighted networks. In the model selection process, the results demonstrate that our approach outperforms other state-of-the-art methods with respect to accuracy.

Comparative study of the geostatistical ore reserve estimation method over the conventional methods

International Nuclear Information System (INIS)

Kim, Y.C.; Knudsen, H.P.

1975-01-01

Part I contains a comprehensive treatment of the comparative study of the geostatistical ore reserve estimation method over the conventional methods. The conventional methods chosen for comparison were: (a) the polygon method, (b) the inverse of the distance squared method, and (c) a method similar to (b) but allowing different weights in different directions. Briefly, the overall result from this comparative study is in favor of the use of geostatistics in most cases because the method has lived up to its theoretical claims. A good exposition on the theory of geostatistics, the adopted study procedures, conclusions and recommended future research are given in Part I. Part II of this report contains the results of the second and the third study objectives, which are to assess the potential benefits that can be derived by the introduction of the geostatistical method to the current state-of-the-art in uranium reserve estimation method and to be instrumental in generating the acceptance of the new method by practitioners through illustrative examples, assuming its superiority and practicality. These are given in the form of illustrative examples on the use of geostatistics and the accompanying computer program user's guide

Exploring methods for comparing the real-world effectiveness of treatments for osteoporosis: adjusted direct comparisons versus using patients as their own control.

Science.gov (United States)

Karlsson, Linda; Mesterton, Johan; Tepie, Maurille Feudjo; Intorcia, Michele; Overbeek, Jetty; Ström, Oskar

2017-09-21

Using Swedish and Dutch registry data for women initiating bisphosphonates, we evaluated two methods of comparing the real-world effectiveness of osteoporosis treatments that attempt to adjust for differences in patient baseline characteristics. Each method has advantages and disadvantages; both are potential complements to clinical trial analyses. We evaluated methods of comparing the real-world effectiveness of osteoporosis treatments that attempt to adjust for both observed and unobserved confounding. Swedish and Dutch registry data for women initiating zoledronate or oral bisphosphonates (OBPs; alendronate/risedronate) were used; the primary outcome was fracture. In adjusted direct comparisons (ADCs), regression and matching techniques were used to account for baseline differences in known risk factors for fracture (e.g., age, previous fracture, comorbidities). In an own-control analysis (OCA), for each treatment, fracture incidence in the first 90 days following treatment initiation (the baseline risk period) was compared with fracture incidence in the 1-year period starting 91 days after treatment initiation (the treatment exposure period). In total, 1196 and 149 women initiating zoledronate and 14,764 and 25,058 initiating OBPs were eligible in the Swedish and Dutch registries, respectively. Owing to the small Dutch zoledronate sample, only the Swedish data were used to compare fracture incidences between treatment groups. ADCs showed a numerically higher fracture incidence in the zoledronate than in the OBPs group (hazard ratio 1.09-1.21; not statistically significant, p > 0.05). For both treatment groups, OCA showed a higher fracture incidence in the baseline risk period than in the treatment exposure period, indicating a treatment effect. OCA showed a similar or greater effect in the zoledronate group compared with the OBPs group. ADC and OCA each possesses advantages and disadvantages. Combining both methods may provide an estimate of real

Implementation of direct LSC method for diesel samples on the fuel market

International Nuclear Information System (INIS)

Krištof, Romana; Hirsch, Marko; Kožar Logar, Jasmina

2014-01-01

The European Union develops common EU policy and strategy on biofuels and sustainable bio-economy through several documents. The encouragement of biofuel's consumption is therefore the obligation of each EU member state. The situation in Slovenian fuel market is presented and compared with other EU countries in the frame of prescribed values from EU directives. Diesel is the most common fuel for transportation needs in Slovenia. The study was therefore performed on diesel. The sampling net was determined in accordance with the fuel consumption statistics of the country. 75 Sampling points were located on different types of roads. The quantity of bio-component in diesel samples was determined by direct LSC method through measurement of C-14 content. The measured values were in the range from 0 up to nearly 6 mass percentage of bio-component in fuel. The method has proved to be appropriate, suitable and effective for studies on the real fuel market. - Highlights: • The direct LSC method was tested and applied on real fuel samples from the Slovenian market. • The results of the study are comparable with the findings of official of EUROSTAT's report. • Comparison to other EU member states and EU directive prescription was performed

Operational impact of using a vanadate oxidase method for direct bilirubin measurements at an academic medical center clinical laboratory.

Science.gov (United States)

Dhungana, Neha; Morris, Cory; Krasowski, Matthew D

2017-08-01

The aim of this study was to compare the operational impact of using vanadate oxidase versus diazo direct bilirubin assays for an academic medical center patient population. Retrospective study was done over an approximately 3.5 year period. The main automated chemistry instrumentation was a Roche Diagnostics cobas 8000 line. The Roche Direct Bilirubin assay was compared to Diazyme Laboratories Direct Bilirubin Assay and Randox Laboratories Direct Bilirubin assay using manufacturer's guidelines for hemolysis index, lipemia index, and analytical measurement range (AMR). Retrospective data was analyzed for 47,333 serum/plasma specimens that had clinical orders for direct bilirubin. A total of 5943 specimens (12.6%) exceeded the hemolysis index limit for the Roche method compared to only 0.2% and 0.05% of specimens for the Diazyme and Randox methods, respectively. The impact was particularly large on patients less than 2 years old, for which 51.3% of specimens exceeded the hemolysis index for the Roche method. A total of 1671 specimens (3.5%) exceeded the lipemia index limit for the Roche method compared to less than 0.1% for the Randox method. Lastly, 988 (2.1%) of specimens had direct bilirubin concentrations exceeding the upper AMR limit of 10 mg/dL [171 µmol/L] for the Roche assay compared to less than 1% of specimens for the vanadate oxidase methods. Vanadate oxidase direct bilirubin methods offer advantages over diazo methods in terms of less interference by hemolysis and lipemia, as well as wider AMR. The advantages are particularly evident for neonatal and infant populations.

A comparison of response spectrum and direct integration analysis methods as applied to a nuclear component support structure

International Nuclear Information System (INIS)

Bryan, B.J.; Flanders, H.E. Jr.

1992-01-01

Seismic qualification of Class I nuclear components is accomplished using a variety of analytical methods. This paper compares the results of time history dynamic analyses of a heat exchanger support structure using response spectrum and time history direct integration analysis methods. Dynamic analysis is performed on the detailed component models using the two methods. A nonlinear elastic model is used for both the response spectrum and direct integration methods. A nonlinear model which includes friction and nonlinear springs, is analyzed using time history input by direct integration. The loads from the three cases are compared

Direct Discrete Method for Neutronic Calculations

International Nuclear Information System (INIS)

Vosoughi, Naser; Akbar Salehi, Ali; Shahriari, Majid

2002-01-01

The objective of this paper is to introduce a new direct method for neutronic calculations. This method which is named Direct Discrete Method, is simpler than the neutron Transport equation and also more compatible with physical meaning of problems. This method is based on physic of problem and with meshing of the desired geometry, writing the balance equation for each mesh intervals and with notice to the conjunction between these mesh intervals, produce the final discrete equations series without production of neutron transport differential equation and mandatory passing from differential equation bridge. We have produced neutron discrete equations for a cylindrical shape with two boundary conditions in one group energy. The correction of the results from this method are tested with MCNP-4B code execution. (authors)

Comparing the Efficacy of Excitatory Transcranial Stimulation Methods Measuring Motor Evoked Potentials

Directory of Open Access Journals (Sweden)

Vera Moliadze

2014-01-01

Full Text Available The common aim of transcranial stimulation methods is the induction or alterations of cortical excitability in a controlled way. Significant effects of each individual stimulation method have been published; however, conclusive direct comparisons of many of these methods are rare. The aim of the present study was to compare the efficacy of three widely applied stimulation methods inducing excitability enhancement in the motor cortex: 1 mA anodal transcranial direct current stimulation (atDCS, intermittent theta burst stimulation (iTBS, and 1 mA transcranial random noise stimulation (tRNS within one subject group. The effect of each stimulation condition was quantified by evaluating motor-evoked-potential amplitudes (MEPs in a fixed time sequence after stimulation. The analyses confirmed a significant enhancement of the M1 excitability caused by all three types of active stimulations compared to sham stimulation. There was no significant difference between the types of active stimulations, although the time course of the excitatory effects slightly differed. Among the stimulation methods, tRNS resulted in the strongest and atDCS significantly longest MEP increase compared to sham. Different time courses of the applied stimulation methods suggest different underlying mechanisms of action. Better understanding may be useful for better targeting of different transcranial stimulation techniques.

Measurement of plant and soil water isotope composition by direct equilibration methods

Science.gov (United States)

Scrimgeour, C. M.

1995-11-01

Water contained in plant and soil samples can be analysed for 2H and 18O content by direct equilibration while contained within the sample matrix. Methods for this are described and compared with the commonly used azeotropic distillation of samples before isotope analysis. For δ18O, direct equilibration with CO 2 gives results in good agreement with azeotropic distillation, i.e. within 0.5%o at natural abundance. Direct equilibration is a practical method for individual twig samples containing less than 0.5 ml of water, and offers significant operator time savings compared with azeotropic distillation. Batches of up to 100 samples can be prepared in less time than required for a single azeotropic distillation, and analysis by automated continuous-flow isotope ratio mass spectrometry after equilibration for 3 days again requires a minimum of operator time. Complete equilibration of plant water with H 2 for δ2H measurement occurs only after the plant material has been heated to 100°C under vacuum. The method described here is barely precise enough for natural abundance measurements ( δ 2H ± 15‰ ) but is well suited to field tracer studies with deuterium oxide.

Operational impact of using a vanadate oxidase method for direct bilirubin measurements at an academic medical center clinical laboratory

Directory of Open Access Journals (Sweden)

Neha Dhungana

2017-08-01

Full Text Available Objectives: The aim of this study was to compare the operational impact of using vanadate oxidase versus diazo direct bilirubin assays for an academic medical center patient population. Design and methods: Retrospective study was done over an approximately 3.5 year period. The main automated chemistry instrumentation was a Roche Diagnostics cobas 8000 line. The Roche Direct Bilirubin assay was compared to Diazyme Laboratories Direct Bilirubin Assay and Randox Laboratories Direct Bilirubin assay using manufacturer's guidelines for hemolysis index, lipemia index, and analytical measurement range (AMR. Results: Retrospective data was analyzed for 47,333 serum/plasma specimens that had clinical orders for direct bilirubin. A total of 5943 specimens (12.6% exceeded the hemolysis index limit for the Roche method compared to only 0.2% and 0.05% of specimens for the Diazyme and Randox methods, respectively. The impact was particularly large on patients less than 2 years old, for which 51.3% of specimens exceeded the hemolysis index for the Roche method. A total of 1671 specimens (3.5% exceeded the lipemia index limit for the Roche method compared to less than 0.1% for the Randox method. Lastly, 988 (2.1% of specimens had direct bilirubin concentrations exceeding the upper AMR limit of 10 mg/dL [171 µmol/L] for the Roche assay compared to less than 1% of specimens for the vanadate oxidase methods. Conclusions: Vanadate oxidase direct bilirubin methods offer advantages over diazo methods in terms of less interference by hemolysis and lipemia, as well as wider AMR. The advantages are particularly evident for neonatal and infant populations. Keywords: Bilirubin, Clinical chemistry tests, Hemolysis, Hyperlipidemias, Jaundice, Photometry

Neutron methods for the direct determination of the magnetic induction in thick films

Energy Technology Data Exchange (ETDEWEB)

Kozhevnikov, S.V., E-mail: kozhevn@nf.jinr.ru [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Ott, F. [CEA, IRAMIS, Laboratoire Léon Brillouin, F-91191 Gif sur Yvette (France); CNRS, IRAMIS, Laboratoire Léon Brillouin, F-91191 Gif sur Yvette (France); Radu, F. [Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein Strasse 15, D-12489 Berlin (Germany)

2016-03-15

We review different neutron methods which allow extracting directly the value of the magnetic induction in thick films: Larmor precession, Zeeman spatial beam-splitting and neutron spin resonance. Resulting parameters obtained by the neutron methods and standard magnetometry technique are presented and compared. The possibilities and specificities of the neutron methods are discussed. - Highlights: • We present neutron methods for investigations of the thick magnetic films. • It is the methods for the direct determination of the magnetic induction. • Magnetic induction in bulk, at single interface and in a single domain. • It is Larmor precession, Zeeman spatial beam-splitting and neutron spin resonance. • These methods are complementary to polarized neutron reflectometry.

OCT evaluation of directional atherectomy compared to balloon angioplasty

International Nuclear Information System (INIS)

Marmagkiolis, Konstantinos; Lendel, Vasili; Cilingiroglu, Mehmet

2015-01-01

Directional atherectomy (DA) is one of the most commonly used modalities for the treatment of obstructive femoropopliteal peripheral arterial disease (PAD), especially in patients with large and calcified atherosclerotic plaques. The effect of directional atherectomy to the vascular wall compared to balloon angioplasty by optical coherence tomography (OCT) has not been previously described. We present the first case of OCT after directional atherectomy with SilverHawk followed by angiosculpt balloon angioplasty. - Highlights: • Directional atherectomy avoids the vascular mechanical damage caused by angioplasty balloons and the exposure of stent struts or the potential of stent fracture with stents. • OCT can accurately assess the effect of endovacular interventions to the vessel wall. • Although angiographic results after directional atherectomy are acceptable, OCT use demonstrated suboptimal improvement of the MLA requiring additional balloon angioplasty. • Longer studies are needed to define whether the improved OCT results with angioplasty compared to DA may offer better clinical outcomes.

OCT evaluation of directional atherectomy compared to balloon angioplasty

Energy Technology Data Exchange (ETDEWEB)

Marmagkiolis, Konstantinos [Citizens Memorial Hospital Heart and Vascular Institute, Bolivar, MO (United States); Lendel, Vasili [Arkansas Heart Hospital, Peripheral Vascular Institute, Little Rock, AR (United States); Cilingiroglu, Mehmet, E-mail: mcilingiroglu@yahoo.com [Arkansas Heart Hospital, Peripheral Vascular Institute, Little Rock, AR (United States); Koc University, School of Medicine, Istanbul (Turkey)

2015-09-15

Directional atherectomy (DA) is one of the most commonly used modalities for the treatment of obstructive femoropopliteal peripheral arterial disease (PAD), especially in patients with large and calcified atherosclerotic plaques. The effect of directional atherectomy to the vascular wall compared to balloon angioplasty by optical coherence tomography (OCT) has not been previously described. We present the first case of OCT after directional atherectomy with SilverHawk followed by angiosculpt balloon angioplasty. - Highlights: • Directional atherectomy avoids the vascular mechanical damage caused by angioplasty balloons and the exposure of stent struts or the potential of stent fracture with stents. • OCT can accurately assess the effect of endovacular interventions to the vessel wall. • Although angiographic results after directional atherectomy are acceptable, OCT use demonstrated suboptimal improvement of the MLA requiring additional balloon angioplasty. • Longer studies are needed to define whether the improved OCT results with angioplasty compared to DA may offer better clinical outcomes.

The effective atomic numbers of some biomolecules calculated by two methods: A comparative study

Energy Technology Data Exchange (ETDEWEB)

Manohara, S. R.; Hanagodimath, S. M.; Gerward, L. [Department of Physics, Gulbarga University, Gulbarga, Karnataka 585 106 (India); Department of Physics, Technical University of Denmark, Lyngby DK-2800 (Denmark)

2009-01-15

The effective atomic numbers Z{sub eff} of some fatty acids and amino acids have been calculated by two numerical methods, a direct method and an interpolation method, in the energy range of 1 keV-20 MeV. The notion of Z{sub eff} is given a new meaning by using a modern database of photon interaction cross sections (WinXCom). The results of the two methods are compared and discussed. It is shown that for all biomolecules the direct method gives larger values of Z{sub eff} than the interpolation method, in particular at low energies (1-100 keV) At medium energies (0.1-5 MeV), Z{sub eff} for both methods is about constant and equal to the mean atomic number of the material. Wherever possible, the calculated values of Z{sub eff} are compared with experimental data.

The effective atomic numbers of some biomolecules calculated by two methods: A comparative study

International Nuclear Information System (INIS)

Manohara, S. R.; Hanagodimath, S. M.; Gerward, L.

2009-01-01

The effective atomic numbers Z eff of some fatty acids and amino acids have been calculated by two numerical methods, a direct method and an interpolation method, in the energy range of 1 keV-20 MeV. The notion of Z eff is given a new meaning by using a modern database of photon interaction cross sections (WinXCom). The results of the two methods are compared and discussed. It is shown that for all biomolecules the direct method gives larger values of Z eff than the interpolation method, in particular at low energies (1-100 keV) At medium energies (0.1-5 MeV), Z eff for both methods is about constant and equal to the mean atomic number of the material. Wherever possible, the calculated values of Z eff are compared with experimental data.

Low rank alternating direction method of multipliers reconstruction for MR fingerprinting.

Science.gov (United States)

Assländer, Jakob; Cloos, Martijn A; Knoll, Florian; Sodickson, Daniel K; Hennig, Jürgen; Lattanzi, Riccardo

2018-01-01

The proposed reconstruction framework addresses the reconstruction accuracy, noise propagation and computation time for magnetic resonance fingerprinting. Based on a singular value decomposition of the signal evolution, magnetic resonance fingerprinting is formulated as a low rank (LR) inverse problem in which one image is reconstructed for each singular value under consideration. This LR approximation of the signal evolution reduces the computational burden by reducing the number of Fourier transformations. Also, the LR approximation improves the conditioning of the problem, which is further improved by extending the LR inverse problem to an augmented Lagrangian that is solved by the alternating direction method of multipliers. The root mean square error and the noise propagation are analyzed in simulations. For verification, in vivo examples are provided. The proposed LR alternating direction method of multipliers approach shows a reduced root mean square error compared to the original fingerprinting reconstruction, to a LR approximation alone and to an alternating direction method of multipliers approach without a LR approximation. Incorporating sensitivity encoding allows for further artifact reduction. The proposed reconstruction provides robust convergence, reduced computational burden and improved image quality compared to other magnetic resonance fingerprinting reconstruction approaches evaluated in this study. Magn Reson Med 79:83-96, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Proteus: a direct forcing method in the simulations of particulate flows

Science.gov (United States)

Feng, Zhi-Gang; Michaelides, Efstathios E.

2005-01-01

A new and efficient direct numerical method for the simulation of particulate flows is introduced. The method combines desired elements of the immersed boundary method, the direct forcing method and the lattice Boltzmann method. Adding a forcing term in the momentum equation enforces the no-slip condition on the boundary of a moving particle. By applying the direct forcing scheme, Proteus eliminates the need for the determination of free parameters, such as the stiffness coefficient in the penalty scheme or the two relaxation parameters in the adaptive-forcing scheme. The method presents a significant improvement over the previously introduced immersed-boundary-lattice-Boltzmann method (IB-LBM) where the forcing term was computed using a penalty method and a user-defined parameter. The method allows the enforcement of the rigid body motion of a particle in a more efficient way. Compared to the "bounce-back" scheme used in the conventional LBM, the direct-forcing method provides a smoother computational boundary for particles and is capable of achieving results at higher Reynolds number flows. By using a set of Lagrangian points to track the boundary of a particle, Proteus eliminates any need for the determination of the boundary nodes that are prescribed by the "bounce-back" scheme at every time step. It also makes computations for particles of irregular shapes simpler and more efficient. Proteus has been developed in two- as well as three-dimensions. This new method has been validated by comparing its results with those from experimental measurements for a single sphere settling in an enclosure under gravity. As a demonstration of the efficiency and capabilities of the present method, the settling of a large number (1232) of spherical particles is simulated in a narrow box under two different boundary conditions. It is found that when the no-slip boundary condition is imposed at the front and rear sides of the box the particles motion is significantly hindered

Comparative studies of high-frequency and direct current molecular gas discharges

International Nuclear Information System (INIS)

Goichman, V.H.; Goldfarb, V.M.; Tendler, M.B.

1975-01-01

Electron gas parameters, gas temperatures, ionization and thermal instability are found to be markedly different in direct current glow discharges from capactive electrodless high frequency discharge even when equal net power input is provided. It is reasonable to expect that the combined discharge containing both types of discharges mentioned above may be expected to improve significantly both the steady-state and transient characteristics of the plasma. The characteristics of different discharges in air, nitrogen air-CO 2 -He mixture have been compared. Because of the lack of the direct electrical methods for measurements of the hf plasma, exphasis in this investigation has been laid on both theoretical) based on the analytical expression for electron energy distribution function received previously and experimental spectroscopic evaluations of the plasma parameters. (Auth.)

Development of rupture process analysis method for great earthquakes using Direct Solution Method

Science.gov (United States)

Yoshimoto, M.; Yamanaka, Y.; Takeuchi, N.

2010-12-01

Conventional rupture process analysis methods using teleseismic body waves were based on ray theory. Therefore, these methods have the following problems in applying to great earthquakes such as 2004 Sumatra earthquake: (1) difficulty in computing all later phases such as the PP reflection phase, (2) impossibility of computing called “W phase”, the long period phase arriving before S wave, (3) implausibility of hypothesis that the distance is far enough from the observation points to the hypocenter compared to the fault length. To solve above mentioned problems, we have developed a new method which uses the synthetic seismograms computed by the Direct Solution Method (DSM, e.g. Kawai et al. 2006) as Green’s functions. We used the DSM software (http://www.eri.u-tokyo.ac.jp/takeuchi/software/) for computing the Green’s functions up to 1 Hz for the IASP91 (Kennett and Engdahl, 1991) model, and determined the final slip distributions using the waveform inversion method (Kikuchi et al. 2003). First we confirmed whether the Green’s functions computed by DSM were accurate in higher frequencies up to 1 Hz. Next we performed the rupture process analysis of this new method for Mw8.0 (GCMT) large Solomon Islands earthquake on April 1, 2007. We found that this earthquake consisted of two asperities and the rupture propagated across the subducting Sinbo ridge. The obtained slip distribution better correlates to the aftershock distributions than existing method. Furthermore, this new method keep same accuracy of existing method (which has the advantage of calculating) with respect to direct P-wave and reflection phases near the source, and also accurately calculate the later phases such a PP-wave.

Comparing different methods to assess weaver ant abundance in plantation trees

DEFF Research Database (Denmark)

Wargui, Rosine; Offenberg, Joachim; Sinzogan, Antonio

2015-01-01

Weaver ants (Oecophylla spp.) are widely used as effective biological control agents. In order to optimize their use, ant abundance needs to be tracked. As several methods have been used to estimate ant abundance on plantation trees, abundances are not comparable between studies and no guideline...... is available on which method to apply in a particular study. This study compared four existing methods: three methods based on the number of ant trails on the main branches of a tree (called the Peng 1, Peng 2 and Offenberg index) and one method based on the number of ant nests per tree. Branch indices did...... not produce equal scores and cannot be compared directly. The Peng 1 index was the fastest to assess, but showed only limited seasonal fluctuations when ant abundance was high, because it approached its upper limit. The Peng 2 and Offenberg indices were lower and not close to the upper limit and therefore...

Methods of conditioning direct methanol fuel cells

Science.gov (United States)

Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

2005-11-08

Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

Comparing groups randomization and bootstrap methods using R

CERN Document Server

Zieffler, Andrew S; Long, Jeffrey D

2011-01-01

A hands-on guide to using R to carry out key statistical practices in educational and behavioral sciences research Computing has become an essential part of the day-to-day practice of statistical work, broadening the types of questions that can now be addressed by research scientists applying newly derived data analytic techniques. Comparing Groups: Randomization and Bootstrap Methods Using R emphasizes the direct link between scientific research questions and data analysis. Rather than relying on mathematical calculations, this book focus on conceptual explanations and

Purification of crude glycerol from transesterification reaction of palm oil using direct method and multistep method

Science.gov (United States)

Nasir, N. F.; Mirus, M. F.; Ismail, M.

2017-09-01

Crude glycerol which produced from transesterification reaction has limited usage if it does not undergo purification process. It also contains excess methanol, catalyst and soap. Conventionally, purification method of the crude glycerol involves high cost and complex processes. This study aimed to determine the effects of using different purification methods which are direct method (comprises of ion exchange and methanol removal steps) and multistep method (comprises of neutralization, filtration, ion exchange and methanol removal steps). Two crude glycerol samples were investigated; the self-produced sample through the transesterification process of palm oil and the sample obtained from biodiesel plant. Samples were analysed using Fourier Transform Infrared Spectroscopy, Gas Chromatography and High Performance Liquid Chromatography. The results of this study for both samples after purification have showed that the pure glycerol was successfully produced and fatty acid salts were eliminated. Also, the results indicated the absence of methanol in both samples after purification process. In short, the combination of 4 purification steps has contributed to a higher quality of glycerol. Multistep purification method gave a better result compared to the direct method as neutralization and filtration steps helped in removing most excess salt, fatty acid and catalyst.

Theory of direct-interband-transition line shapes based on Mori's method

International Nuclear Information System (INIS)

Sam Nyung Yi; Jai Yon Ryu; Ok Hee Chung; Joung Young Sug; Sang Don Choi; Yeon Choon Chung

1987-01-01

A theory of direct interband optical transition in the electron-phonon system is introduced on the basis of the Kubo formalism and by using Mori's method of calculation. The line shape functions are introduced in two different ways and are compared with those obtained by Choi and Chung based on Argyres and Sigel's projection technique

Comparison of direct and indirect methods of estimating health state utilities for resource allocation: review and empirical analysis.

Science.gov (United States)

Arnold, David; Girling, Alan; Stevens, Andrew; Lilford, Richard

2009-07-22

Utilities (values representing preferences) for healthcare priority setting are typically obtained indirectly by asking patients to fill in a quality of life questionnaire and then converting the results to a utility using population values. We compared such utilities with those obtained directly from patients or the public. Review of studies providing both a direct and indirect utility estimate. Papers reporting comparisons of utilities obtained directly (standard gamble or time tradeoff) or indirectly (European quality of life 5D [EQ-5D], short form 6D [SF-6D], or health utilities index [HUI]) from the same patient. PubMed and Tufts database of utilities. Sign test for paired comparisons between direct and indirect utilities; least squares regression to describe average relations between the different methods. Mean utility scores (or median if means unavailable) for each method, and differences in mean (median) scores between direct and indirect methods. We found 32 studies yielding 83 instances where direct and indirect methods could be compared for health states experienced by adults. The direct methods used were standard gamble in 57 cases and time trade off in 60(34 used both); the indirect methods were EQ-5D (67 cases), SF-6D (13), HUI-2 (5), and HUI-3 (37). Mean utility values were 0.81 (standard gamble) and 0.77 (time tradeoff) for the direct methods; for the indirect methods: 0.59(EQ-5D), 0.63 (SF-6D), 0.75 (HUI-2) and 0.68 (HUI-3). Direct methods of estimating utilities tend to result in higher health ratings than the more widely used indirect methods, and the difference can be substantial.Use of indirect methods could have important implications for decisions about resource allocation: for example, non-lifesaving treatments are relatively more favoured in comparison with lifesaving interventions than when using direct methods.

OCT evaluation of directional atherectomy compared to balloon angioplasty.

Science.gov (United States)

Marmagkiolis, Konstantinos; Lendel, Vasili; Cilingiroglu, Mehmet

2015-09-01

Directional atherectomy (DA) is one of the most commonly used modalities for the treatment of obstructive femoropopliteal peripheral arterial disease (PAD), especially in patients with large and calcified atherosclerotic plaques. The effect of directional atherectomy to the vascular wall compared to balloon angioplasty by optical coherence tomography (OCT) has not been previously described. We present the first case of OCT after directional atherectomy with SilverHawk followed by angiosculpt balloon angioplasty. Copyright © 2015 Elsevier Inc. All rights reserved.

Direct runoff assessment using modified SME method in catchments in the Upper Vistula River Basin

Science.gov (United States)

Wałęga, A.; Rutkowska, A.; Grzebinoga, M.

2017-04-01

Correct determination of direct runoff is crucial for proper and safe dimensioning of hydroengineering structures. It is commonly assessed using SCS-CN method developed in the United States. However, due to deficiencies of this method, many improvements and modifications have been proposed. In this paper, a modified Sahu-Mishra-Eldo (SME) method was introduced and tested for three catchments located in the upper Vistula basin. Modification of SME method involved a determination of maximum potential retention S based on CN parameter derived from SCS-CN method. The modified SME method yielded direct runoff values very similar to those observed in the investigated catchments. Moreover, it generated significantly smaller errors in the direct runoff estimation as compared with SCS-CN and SME methods in the analyzed catchments. This approach may be used for estimating the runoff in uncontrolled catchments.

Direct methods for radionuclides measurement in water environment

International Nuclear Information System (INIS)

Chernyaev, A.; Gaponov, I.; Kazennov, A.

2004-01-01

The paper is devoted to the direct method of anthropogenic radionuclide measurement in the water environment. Opportunities of application of submersible gamma-spectrometers for in situ underwater measurements of gamma-radiating nuclides and also the direct method for 90 Sr detection are considered

Alternating direction transport sweeps for linear discontinuous SN method

International Nuclear Information System (INIS)

Yavuz, M.; Aykanat, C.

1993-01-01

The performance of Alternating Direction Transport Sweep (ADTS) method is investigated for spatially differenced Linear Discontinuous S N (LD-S N ) problems on a MIMD multicomputer, Intel IPSC/2. The method consists of dividing a transport problem spatially into sub-problems, assigning each sub-problem to a separate processor. Then, the problem is solved by performing transport sweeps iterating on the scattering source and interface fluxes between the sub-problems. In each processor, the order of transport sweeps is scheduled such that a processor completing its computation in a quadrant of a transport sweep is able to use the most recent information (exiting fluxes of neighboring processor) as its incoming fluxes to start the next quadrant calculation. Implementation of this method on the Intel IPSC/2 multicomputer displays significant speedups over the one-processor method. Also, the performance of the method is compared with those reported previously for the Diamond Differenced S N (DD-S N ) method. Our experimental experience illustrates that the parallel performance of both the ADTS LD- and DD-S N methods is the same. (orig.)

In support of the importance of development comparative method in sociology

Directory of Open Access Journals (Sweden)

Baščarević Ivan M.

2012-01-01

Full Text Available The importance of comparative methods in social research is now almost non-debatable. In contemporary sociological literature there are many papers that indicate the use of the sociological (and not only sociological method. In addition, in international surveys carried out in the comparative-historical studies, there is a long-term tradition of development issues of comparative method in the study of social phenomena. This text is designed as a contribution to understanding the contribution of important comparative method in contemporary social research. Usefulness of comparative method became apparent to the classicists of sociology - K. Marx, E. Durkheim and M. Weber, and even much earlier to Auguste Comte. Their work (with the exception of Comte, despite many criticisms that are often moving in the direction of a lack of systematic and reliable source material, has an outstanding contribution in terms of highlighting the importance and application of comparative method. E. Durkheim was among the first to try to determine its epistemological significance. Critics of their actions, however, do not sufficiently take into account the limitations of that age, especially in underdeveloped standardization and classification of the data collected. The period of the sixties marked that, after a short delay, following re-affirmation and development of comparative methods in social research emerged. This was largely contributed by criticism of classical ideas related to this method, together with the 'fake controversy' between supporters of quantitative and qualitative methodology. A lot has been done in terms of standardization of comparative method and empirical information by training funds for the classification and measurement, and modern technical means by which it is possible to achieve a simple collection and processing of comparable data. By improvement of these methods, the shortcomings that accompanied comparative research in the past would

Comparative analysis of direct and indirect property investment ...

African Journals Online (AJOL)

Comparative analysis of direct and indirect property investment returns in Abuja. ... in property shares is more risky than commercial property due to the risk ... of the stock market, it was discovered that there is a strong positive relationship ...

Alternating direction methods for classical and ptychographic phase retrieval

International Nuclear Information System (INIS)

Wen, Zaiwen; Yang, Chao; Liu, Xin; Marchesini, Stefano

2012-01-01

In this paper, we show how the augmented Lagrangian alternating direction method (ADM) can be used to solve both the classical and ptychographic phase retrieval problems. We point out the connection between ADM and projection algorithms such as the hybrid input–output algorithm, and compare its performance against standard algorithms for phase retrieval on a number of test images. Our computational experiments show that ADM appears to be less sensitive to the choice of relaxation parameters, and it usually outperforms the existing techniques for both the classical and ptychographic phase retrieval problems. (paper)

A Randomized Controlled Trial Comparing the Letter Project Advance Directive to Traditional Advance Directive.

Science.gov (United States)

Periyakoil, Vyjeyanthi S; Neri, Eric; Kraemer, Helena

2017-09-01

Simpler alternatives to traditional advance directives that are easy to understand and available in multiple formats and can be initiated by patients and families will help facilitate advance care planning. The goal of this study was to compare the acceptability of the letter advance directive (LAD) to the traditional advance directive (TAD) of the state of California. A web-based, randomized controlled trial was conducted, in which the participants were randomized to one of two types of advance directives (ADs): the LAD (intervention) or the TAD (control). Primary outcomes were participant ratings of the ease, value, and their level of comfort in the AD document they completed. A total of 400 participants completed the study, with 216 randomized to the LAD and 184 to the TAD by a computerized algorithm. Overall, participants preferred the LAD to the TAD (success rate difference [SRD] = 0.46, 95th percentile confidence interval [CI]: 0.36-0.56, p advance directive to be a better alternative to the traditional advance directive form.

Share Valuation Using the Comparative Method

Directory of Open Access Journals (Sweden)

Jana Marková

2016-12-01

Full Text Available The comparative method is one of the methods of assessment of equity securities in theory and practice. The practical application of the comparative method is arranged in MS Decree No. 492/2004 Coll. on the establishment of the universal value of property and in Act No. 431/2002 Coll. on accounting, as amended by later regulations. According to this method, internal (general, real value is derived from information on specific prices or values of shares of similar companies. The comparative method can be applied without serious problems only provided that the differences between the companies are small; otherwise, its use has been problematic. To find a comparable public limited company on a mature capital market, where the number of traded comparable companies is high, is not a problem. It is very difficult for a small market such as Slovakia’s stock market. This paper discusses the application of comparative methods to the non-standard Slovak capital market.

Managerial span of control: a pilot study comparing departmental complexity and number of direct reports.

Science.gov (United States)

Merrill, Katreena Collette; Pepper, Ginette; Blegen, Mary

2013-09-01

Nurse managers play pivotal roles in hospitals. However, restructuring has resulted in nurse managers having wider span of control and reduced visibility. The purpose of this pilot study was to compare two methods of measuring span of control: departmental complexity and number of direct reports. Forty-one nurse managers across nine hospitals completed The Ottawa Hospital Clinical Manager Span of Control Tool (TOH-SOC) and a demographic survey. A moderate positive relationship between number of direct reports and departmental complexity score was identified (r=.49, p=managers' responsibility. Copyright © 2013 Longwoods Publishing.

Comparative study of radiometric and calorimetric methods for total hemispherical emissivity measurements

Science.gov (United States)

Monchau, Jean-Pierre; Hameury, Jacques; Ausset, Patrick; Hay, Bruno; Ibos, Laurent; Candau, Yves

2018-05-01

Accurate knowledge of infrared emissivity is important in applications such as surface temperature measurements by infrared thermography or thermal balance for building walls. A comparison of total hemispherical emissivity measurement was performed by two laboratories: the Laboratoire National de Métrologie et d'Essais (LNE) and the Centre d'Études et de Recherche en Thermique, Environnement et Systèmes (CERTES). Both laboratories performed emissivity measurements on four samples, chosen to cover a large range of emissivity values and angular reflectance behaviors. The samples were polished aluminum (highly specular, low emissivity), bulk PVC (slightly specular, high emissivity), sandblasted aluminum (diffuse surface, medium emissivity), and aluminum paint (slightly specular surface, medium emissivity). Results obtained using five measurement techniques were compared. LNE used a calorimetric method for direct total hemispherical emissivity measurement [1], an absolute reflectometric measurement method [2], and a relative reflectometric measurement method. CERTES used two total hemispherical directional reflectometric measurement methods [3, 4]. For indirect techniques by reflectance measurements, the total hemispherical emissivity values were calculated from directional hemispherical reflectance measurement results using spectral integration when required and directional to hemispherical extrapolation. Results were compared, taking into account measurement uncertainties; an added uncertainty was introduced to account for heterogeneity over the surfaces of the samples and between samples. All techniques gave large relative uncertainties for a low emissive and very specular material (polished aluminum), and results were quite scattered. All the indirect techniques by reflectance measurement gave results within ±0.01 for a high emissivity material. A commercial aluminum paint appears to be a good candidate for producing samples with medium level of emissivity

29 CFR 4211.13 - Modifications to the direct attribution method.

Science.gov (United States)

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Modifications to the direct attribution method. 4211.13... Changes Not Subject to PBGC Approval § 4211.13 Modifications to the direct attribution method. (a) Error in direct attribution method. The unfunded vested benefits allocated to a withdrawing employer under...

An Improved Local Gradient Method for Sea Surface Wind Direction Retrieval from SAR Imagery

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Lizhang Zhou

2017-06-01

Full Text Available Sea surface wind affects the fluxes of energy, mass and momentum between the atmosphere and ocean, and therefore regional and global weather and climate. With various satellite microwave sensors, sea surface wind can be measured with large spatial coverage in almost all-weather conditions, day or night. Like any other remote sensing measurements, sea surface wind measurement is also indirect. Therefore, it is important to develop appropriate wind speed and direction retrieval models for different types of microwave instruments. In this paper, a new sea surface wind direction retrieval method from synthetic aperture radar (SAR imagery is developed. In the method, local gradients are computed in frequency domain by combining the operation of smoothing and computing local gradients in one step to simplify the process and avoid the difference approximation. This improved local gradients (ILG method is compared with the traditional two-dimensional fast Fourier transform (2D FFT method and local gradients (LG method, using interpolating wind directions from the European Centre for Medium-Range Weather Forecast (ECMWF reanalysis data and the Cross-Calibrated Multi-Platform (CCMP wind vector product. The sensitivities to the salt-and-pepper noise, the additive noise and the multiplicative noise are analyzed. The ILG method shows a better performance of retrieval wind directions than the other two methods.

Optimal design method for magnetization directions of a permanent magnet array

Energy Technology Data Exchange (ETDEWEB)

Choi, Jae Seok [Center for Information Storage Device, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Yoo, Jeonghoon, E-mail: yoojh@yonsei.ac.k [School of Mechanical Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

2010-08-15

In many magnetic systems, the permanent magnet (PM) pattern has a great influence on their performance. This study proposes a systematic optimization method for designing discrete magnetization directions. While previous works have been mostly dependent on researchers' intuition, the developed method is systematic and can be applied to a two-dimensional PM-type eddy current brake model. The effectiveness of the method is confirmed, where the design's aim is to maximize the braking force on a moving conductor. The sensitivity analysis is accomplished by the adjoint variable method and the sequential linear programming is used as an optimizer. Several optimization results for various conditions through the proposed design method are compared to each other and the optimal magnet configuration for an eddy current brake is suggested.

Direct sampling methods for inverse elastic scattering problems

Science.gov (United States)

Ji, Xia; Liu, Xiaodong; Xi, Yingxia

2018-03-01

We consider the inverse elastic scattering of incident plane compressional and shear waves from the knowledge of the far field patterns. Specifically, three direct sampling methods for location and shape reconstruction are proposed using the different component of the far field patterns. Only inner products are involved in the computation, thus the novel sampling methods are very simple and fast to be implemented. With the help of the factorization of the far field operator, we give a lower bound of the proposed indicator functionals for sampling points inside the scatterers. While for the sampling points outside the scatterers, we show that the indicator functionals decay like the Bessel functions as the sampling point goes away from the boundary of the scatterers. We also show that the proposed indicator functionals continuously dependent on the far field patterns, which further implies that the novel sampling methods are extremely stable with respect to data error. For the case when the observation directions are restricted into the limited aperture, we firstly introduce some data retrieval techniques to obtain those data that can not be measured directly and then use the proposed direct sampling methods for location and shape reconstructions. Finally, some numerical simulations in two dimensions are conducted with noisy data, and the results further verify the effectiveness and robustness of the proposed sampling methods, even for multiple multiscale cases and limited-aperture problems.

Sparse Pseudo Spectral Projection Methods with Directional Adaptation for Uncertainty Quantification

KAUST Repository

Winokur, J.

2015-12-19

We investigate two methods to build a polynomial approximation of a model output depending on some parameters. The two approaches are based on pseudo-spectral projection (PSP) methods on adaptively constructed sparse grids, and aim at providing a finer control of the resolution along two distinct subsets of model parameters. The control of the error along different subsets of parameters may be needed for instance in the case of a model depending on uncertain parameters and deterministic design variables. We first consider a nested approach where an independent adaptive sparse grid PSP is performed along the first set of directions only, and at each point a sparse grid is constructed adaptively in the second set of directions. We then consider the application of aPSP in the space of all parameters, and introduce directional refinement criteria to provide a tighter control of the projection error along individual dimensions. Specifically, we use a Sobol decomposition of the projection surpluses to tune the sparse grid adaptation. The behavior and performance of the two approaches are compared for a simple two-dimensional test problem and for a shock-tube ignition model involving 22 uncertain parameters and 3 design parameters. The numerical experiments indicate that whereas both methods provide effective means for tuning the quality of the representation along distinct subsets of parameters, PSP in the global parameter space generally requires fewer model evaluations than the nested approach to achieve similar projection error. In addition, the global approach is better suited for generalization to more than two subsets of directions.

Preparation of a pure 99mTc-F(ab')2 radioimmunoconjugate by direct labeling methods

International Nuclear Information System (INIS)

Griffiths, G.L.; Jones, A.L.; Hansen, H.J.; Goldenberg, D.M.

1994-01-01

Intact IgG and Fab' can be labeled directly with 99m Tc to give quantitative incorporation of radioactivity into the protein. With F(ab') 2 the reductive conditions yield a mixture of 99m Tc-F(ab') 2 and 99m Tc-Fab'. We now report a direct labeling method to produce only 99m Tc-F(ab') 2 in quantitative yield and contaminated with 99m Tc-Fab'. The properties, stability and biodistribution of the 99m Tc-F(ab') 2 have been compared to 99m Tc-Fab'. This new technology will allow us to compare technetium direct-labeled IgG, F(ab') 2 and Fab' derivatives of the same antibody for radioimmunodetection. (author)

Performing T-tests to Compare Autocorrelated Time Series Data Collected from Direct-Reading Instruments.

Science.gov (United States)

O'Shaughnessy, Patrick; Cavanaugh, Joseph E

2015-01-01

Industrial hygienists now commonly use direct-reading instruments to evaluate hazards in the workplace. The stored values over time from these instruments constitute a time series of measurements that are often autocorrelated. Given the need to statistically compare two occupational scenarios using values from a direct-reading instrument, a t-test must consider measurement autocorrelation or the resulting test will have a largely inflated type-1 error probability (false rejection of the null hypothesis). A method is described for both the one-sample and two-sample cases which properly adjusts for autocorrelation. This method involves the computation of an "equivalent sample size" that effectively decreases the actual sample size when determining the standard error of the mean for the time series. An example is provided for the one-sample case, and an example is given where a two-sample t-test is conducted for two autocorrelated time series comprised of lognormally distributed measurements.

Inter-comparison of different direct and indirect methods to determine radon flux from soil

International Nuclear Information System (INIS)

Grossi, C.; Vargas, A.; Camacho, A.; Lopez-Coto, I.; Bolivar, J.P.; Xia Yu; Conen, F.

2011-01-01

The physical and chemical characteristics of radon gas make it a good tracer for use in the application of atmospheric transport models. For this purpose the radon source needs to be known on a global scale and this is difficult to achieve by only direct experimental methods. However, indirect methods can provide radon flux maps on larger scales, but their reliability has to be carefully checked. It is the aim of this work to compare radon flux values obtained by direct and indirect methods in a measurement campaign performed in the summer of 2008. Different systems to directly measure radon flux from the soil surface and to measure the related parameters terrestrial γ dose and 226 Ra activity in soil, for indirect estimation of radon flux, were tested. Four eastern Spanish sites with different geological and soil characteristics were selected: Teruel, Los Pedrones, Quintanar de la Orden and Madrid. The study shows the usefulness of both direct and indirect methods for obtaining radon flux data. Direct radon flux measurements by continuous and integrated monitors showed a coefficient of variation between 10% and 23%. At the same time, indirect methods based on correlations between 222 Rn and terrestrial γ dose rate, or 226 Ra activity in soil, provided results similar to the direct measurements, when these proxies were directly measured at the site. Larger discrepancies were found when proxy values were extracted from existing data bases. The participating members involved in the campaign study were the Institute of Energy Technology (INTE) of the Technical University of Catalonia (UPC), Huelva University (UHU), and Basel University (BASEL).

Direct versus indirect revascularization procedures for moyamoya disease: a comparative effectiveness study.

Science.gov (United States)

Macyszyn, Luke; Attiah, Mark; Ma, Tracy S; Ali, Zarina; Faught, Ryan; Hossain, Alisha; Man, Karen; Patel, Hiren; Sobota, Rosanna; Zager, Eric L; Stein, Sherman C

2017-05-01

OBJECTIVE Moyamoya disease (MMD) is a chronic cerebrovascular disease that can lead to devastating neurological outcomes. Surgical intervention is the definitive treatment, with direct, indirect, and combined revascularization procedures currently employed by surgeons. The optimal surgical approach, however, remains unclear. In this decision analysis, the authors compared the effectiveness of revascularization procedures in both adult and pediatric patients with MMD. METHODS A comprehensive literature search was performed for studies of MMD. Using complication and success rates from the literature, the authors constructed a decision analysis model for treatment using a direct and indirect revascularization technique. Utility values for the various outcomes and complications were extracted from the literature examining preferences in similar clinical conditions. Sensitivity analysis was performed. RESULTS A structured literature search yielded 33 studies involving 4197 cases. Cases were divided into adult and pediatric populations. These were further subdivided into 3 different treatment groups: indirect, direct, and combined revascularization procedures. In the pediatric population at 5- and 10-year follow-up, there was no significant difference between indirect and combination procedures, but both were superior to direct revascularization. In adults at 4-year follow-up, indirect was superior to direct revascularization. CONCLUSIONS In the absence of factors that dictate a specific approach, the present decision analysis suggests that direct revascularization procedures are inferior in terms of quality-adjusted life years in both adults at 4 years and children at 5 and 10 years postoperatively, respectively. These findings were statistically significant (p indirect and combination procedures may offer optimal results at long-term follow-up.

The direct Discontinuous Galerkin method for the compressible Navier-Stokes equations on arbitrary grids

Science.gov (United States)

Yang, Xiaoquan; Cheng, Jian; Liu, Tiegang; Luo, Hong

2015-11-01

The direct discontinuous Galerkin (DDG) method based on a traditional discontinuous Galerkin (DG) formulation is extended and implemented for solving the compressible Navier-Stokes equations on arbitrary grids. Compared to the widely used second Bassi-Rebay (BR2) scheme for the discretization of diffusive fluxes, the DDG method has two attractive features: first, it is simple to implement as it is directly based on the weak form, and therefore there is no need for any local or global lifting operator; second, it can deliver comparable results, if not better than BR2 scheme, in a more efficient way with much less CPU time. Two approaches to perform the DDG flux for the Navier- Stokes equations are presented in this work, one is based on conservative variables, the other is based on primitive variables. In the implementation of the DDG method for arbitrary grid, the definition of mesh size plays a critical role as the formation of viscous flux explicitly depends on the geometry. A variety of test cases are presented to demonstrate the accuracy and efficiency of the DDG method for discretizing the viscous fluxes in the compressible Navier-Stokes equations on arbitrary grids.

Method for observing phase objects without halos and directional shadows

Science.gov (United States)

Suzuki, Yoshimasa; Kajitani, Kazuo; Ohde, Hisashi

2015-03-01

A new microscopy method for observing phase objects without halos and directional shadows is proposed. The key optical element is an annular aperture at the front focal plane of a condenser with a larger diameter than those used in standard phase contrast microscopy. The light flux passing through the annular aperture is changed by the specimen's surface profile and then passes through an objective and contributes to image formation. This paper presents essential conditions for realizing the method. In this paper, images of colonies formed by induced pluripotent stem (iPS) cells using this method are compared with the conventional phase contrast method and the bright-field method when the NA of the illumination is small to identify differences among these techniques. The outlines of the iPS cells are clearly visible with this method, whereas they are not clearly visible due to halos when using the phase contrast method or due to weak contrast when using the bright-field method. Other images using this method are also presented to demonstrate a capacity of this method: a mouse ovum and superimposition of several different images of mouse iPS cells.

Direct infusion-SIM as fast and robust method for absolute protein quantification in complex samples

Directory of Open Access Journals (Sweden)

Christina Looße

2015-06-01

Full Text Available Relative and absolute quantification of proteins in biological and clinical samples are common approaches in proteomics. Until now, targeted protein quantification is mainly performed using a combination of HPLC-based peptide separation and selected reaction monitoring on triple quadrupole mass spectrometers. Here, we show for the first time the potential of absolute quantification using a direct infusion strategy combined with single ion monitoring (SIM on a Q Exactive mass spectrometer. By using complex membrane fractions of Escherichia coli, we absolutely quantified the recombinant expressed heterologous human cytochrome P450 monooxygenase 3A4 (CYP3A4 comparing direct infusion-SIM with conventional HPLC-SIM. Direct-infusion SIM revealed only 14.7% (±4.1 (s.e.m. deviation on average, compared to HPLC-SIM and a decreased processing and analysis time of 4.5 min (that could be further decreased to 30 s for a single sample in contrast to 65 min by the LC–MS method. Summarized, our simplified workflow using direct infusion-SIM provides a fast and robust method for quantification of proteins in complex protein mixtures.

Comparative study of direct and inverse problems of cracked beams

Directory of Open Access Journals (Sweden)

Mahieddine Chettah

2018-01-01

Full Text Available In recent decades, the analysis and evaluation of the cracked structures were hot spots in several engineering fields and has been the subject of great interest with important and comprehensive surveys covering various methodologies and applications, in order to obtain reliable and effective methods to maintain the safety and performance of structures on a proactive basis. The presence of a crack, not only causes a local variation in the structural parameters (e.g., the stiffness of a beam at its location, but it also has a global effect which affects the overall dynamic behavior of the structure (such as the natural frequencies. For this reason, the dynamic characterization of the cracked structures can be used to detect damage from non-destructive testing. The objective of this paper is to compare the accuracy and ability of two methods to correctly predict the results for both direct problem to find natural frequencies and inverse problem to find crack’s locations and depths of a cracked simply supported beam. Several cases of crack depths and crack locations are investigated. The crack is supposed to remain open. The Euler–Bernoulli beam theory is employed to model the cracked beam and the crack is represented as a rotational spring with a sectional flexibility. In the first method, the transfer matrix method is used; the cracked beam is modeled as two uniform sub-segments connected by a rotational spring located at the cracked section. In the second method which is based on the Rayleigh’s method, the mode shape of the cracked beam is constructed by adding a cubic polynomial function to that of the undamaged beam. By applying the compatibility conditions at crack’s location and the corresponding boundary conditions, the general forms of characteristic equations for this cracked system are obtained. The two methods are then utilized to determine the locations and depths by using any two natural frequencies of a cracked simply

A comparative study of direct and indirect solar drying of mango ...

African Journals Online (AJOL)

A comparative study of direct and indirect solar drying of mango. ... Thus, indirect solar dryer was found to be suitable for industrial or semi industrial mango drying, whereas direct solar dryer was appropriate to a family ... HOW TO USE AJOL.

Direct numerical methods of mathematical modeling in mechanical structural design

International Nuclear Information System (INIS)

Sahili, Jihad; Verchery, Georges; Ghaddar, Ahmad; Zoaeter, Mohamed

2002-01-01

Full text.Structural design and numerical methods are generally interactive; requiring optimization procedures as the structure is analyzed. This analysis leads to define some mathematical terms, as the stiffness matrix, which are resulting from the modeling and then used in numerical techniques during the dimensioning procedure. These techniques and many others involve the calculation of the generalized inverse of the stiffness matrix, called also the 'compliance matrix'. The aim of this paper is to introduce first, some different existing mathematical procedures, used to calculate the compliance matrix from the stiffness matrix, then apply direct numerical methods to solve the obtained system with the lowest computational time, and to compare the obtained results. The results show a big difference of the computational time between the different procedures

Comparative study for salt stress among seed, root stock and direct ...

African Journals Online (AJOL)

The experiments were carried out to evaluate the comparative study for salt stress among seed, root stock and direct regenerated violet (Viola odorata L.) seedlings. Violet seedlings propagated through tissue culture (direct regeneration) had significantly higher salicylic acid (SA) concentrations from seed and rootstock ...

A Modified Alternating Direction Method for Variational Inequality Problems

International Nuclear Information System (INIS)

Han, D.

2002-01-01

The alternating direction method is an attractive method for solving large-scale variational inequality problems whenever the subproblems can be solved efficiently. However, the subproblems are still variational inequality problems, which are as structurally difficult to solve as the original one. To overcome this disadvantage, in this paper we propose a new alternating direction method for solving a class of nonlinear monotone variational inequality problems. In each iteration the method just makes an orthogonal projection to a simple set and some function evaluations. We report some preliminary computational results to illustrate the efficiency of the method

An efficient direct method for image registration of flat objects

Science.gov (United States)

Nikolaev, Dmitry; Tihonkih, Dmitrii; Makovetskii, Artyom; Voronin, Sergei

2017-09-01

Image alignment of rigid surfaces is a rapidly developing area of research and has many practical applications. Alignment methods can be roughly divided into two types: feature-based methods and direct methods. Known SURF and SIFT algorithms are examples of the feature-based methods. Direct methods refer to those that exploit the pixel intensities without resorting to image features and image-based deformations are general direct method to align images of deformable objects in 3D space. Nevertheless, it is not good for the registration of images of 3D rigid objects since the underlying structure cannot be directly evaluated. In the article, we propose a model that is suitable for image alignment of rigid flat objects under various illumination models. The brightness consistency assumptions used for reconstruction of optimal geometrical transformation. Computer simulation results are provided to illustrate the performance of the proposed algorithm for computing of an accordance between pixels of two images.

Directional fractal signature methods for trabecular bone texture in hand radiographs: Data from the Osteoarthritis Initiative

International Nuclear Information System (INIS)

Wolski, M.; Podsiadlo, P.; Stachowiak, G. W.

2014-01-01

Purpose: To develop directional fractal signature methods for the analysis of trabecular bone (TB) texture in hand radiographs. Problems associated with the small size of hand bones and the orientation of fingers were addressed. Methods: An augmented variance orientation transform (AVOT) and a quadrant rotating grid (QRG) methods were developed. The methods calculate fractal signatures (FSs) in different directions. Unlike other methods they have the search region adjusted according to the size of bone region of interest (ROI) to be analyzed and they produce FSs defined with respect to any chosen reference direction, i.e., they work for arbitrary orientation of fingers. Five parameters at scales ranging from 2 to 14 pixels (depending on image size and method) were derived from rose plots of Hurst coefficients, i.e., FS in dominating roughness (FS Sta ), vertical (FS V ) and horizontal (FS H ) directions, aspect ratio (StrS), and direction signatures (StdS), respectively. The accuracy in measuring surface roughness and isotropy/anisotropy was evaluated using 3600 isotropic and 800 anisotropic fractal surface images of sizes between 20 × 20 and 64 × 64 pixels. The isotropic surfaces had FDs ranging from 2.1 to 2.9 in steps of 0.1, and the anisotropic surfaces had two dominating directions of 30° and 120°. The methods were used to find differences in hand TB textures between 20 matched pairs of subjects with (cases: approximate Kellgren-Lawrence (KL) grade ≥2) and without (controls: approximate KL grade <2) radiographic hand osteoarthritis (OA). The OA Initiative public database was used and 20 × 20 pixel bone ROIs were selected on 5th distal and middle phalanges. The performance of the AVOT and QRG methods was compared against a variance orientation transform (VOT) method developed earlier [M. Wolski, P. Podsiadlo, and G. W. Stachowiak, “Directional fractal signature analysis of trabecular bone: evaluation of different methods to detect early osteoarthritis

A Randomized Controlled Trial Comparing the McKenzie Method to Motor Control Exercises in People With Chronic Low Back Pain and a Directional Preference.

Science.gov (United States)

Halliday, Mark H; Pappas, Evangelos; Hancock, Mark J; Clare, Helen A; Pinto, Rafael Z; Robertson, Gavin; Ferreira, Paulo H

2016-07-01

Study Design Randomized clinical trial. Background Motor control exercises are believed to improve coordination of the trunk muscles. It is unclear whether increases in trunk muscle thickness can be facilitated by approaches such as the McKenzie method. Furthermore, it is unclear which approach may have superior clinical outcomes. Objectives The primary aim was to compare the effects of the McKenzie method and motor control exercises on trunk muscle recruitment in people with chronic low back pain classified with a directional preference. The secondary aim was to conduct a between-group comparison of outcomes for pain, function, and global perceived effect. Methods Seventy people with chronic low back pain who demonstrated a directional preference using the McKenzie assessment were randomized to receive 12 treatments over 8 weeks with the McKenzie method or with motor control approaches. All outcomes were collected at baseline and at 8-week follow-up by blinded assessors. Results No significant between-group difference was found for trunk muscle thickness of the transversus abdominis (-5.8%; 95% confidence interval [CI]: -15.2%, 3.7%), obliquus internus (-0.7%; 95% CI: -6.6%, 5.2%), and obliquus externus (1.2%; 95% CI: -4.3%, 6.8%). Perceived recovery was slightly superior in the McKenzie group (-0.8; 95% CI: -1.5, -0.1) on a -5 to +5 scale. No significant between-group differences were found for pain or function (P = .99 and P = .26, respectively). Conclusion We found no significant effect of treatment group for trunk muscle thickness. Participants reported a slightly greater sense of perceived recovery with the McKenzie method than with the motor control approach. Level of Evidence Therapy, level 1b-. Registered September 7, 2011 at www.anzctr.org.au (ACTRN12611000971932). J Orthop Sports Phys Ther 2016;46(7):514-522. Epub 12 May 2016. doi:10.2519/jospt.2016.6379.

Comparison of a PCR-Based Method with Culture and Direct Examination for Diagnosis of Acanthamoeba keratitis

Directory of Open Access Journals (Sweden)

S Farnia

2009-05-01

Full Text Available "nBackground: The aim was to compare three different methods (direct examination, culture and PCR meth­ods for the diagnosis of Acanthamoeba keratitis (AK in corneal scrapes."nMethods: Twenty eight corneal scrapes and contact lenses were collected from keratitis patients and re­ferred to the De­partment of Medical Parasitology and Mycology, School of Public Health, Tehran Univer­sity of Medical Sci­ences. Corneal scrapes were divided in three parts for direct examination, culture on non-nutrient agar and PCR analysis. PCR analysis was also performed using a 18S rRNA gene primer pair (DF3 region. DF3 (Diagnostic frag­ment 3 is a region of the nuclear small subunit ribosomal RNA gene which is specific for detecting Acan­thamoeba strains."nResults:  Acanthamoeba was the causative agent of keratitis in 50% of the patients. Direct smear of all pre­pared corneal scrapes in AK patients was negative and culture was positive in only 14.3% of the isolates. PCR analysis was positive in 71.4% of AK patients. These three methods were negative in corneal scrapes of non-AK patients. The sensitivity and specificity of PCR technique for the detection of Acanthamoeba sp. were calculated as 71.4% and 100%, respectively."nConclusion: According to high sensitivity and specificity of PCR-based method, this study confirmed that PCR using 18S rRNA gene primers (DF3 region is more useful for detecting AK cases compare to culture and direct microscopy methods.

Investigation of the effective atomic numbers of dosimetric materials for electrons, protons and alpha particles using a direct method in the energy region 10 keV-1 GeV: a comparative study.

Science.gov (United States)

Kurudirek, Murat; Aksakal, Oğuz; Akkuş, Tuba

2015-11-01

A direct method has been used for the first time, to compute effective atomic numbers (Z eff) of water, air, human tissues, and some organic and inorganic compounds, for total electron proton and alpha particle interaction in the energy region 10 keV-1 GeV. The obtained values for Z eff were then compared to those obtained using an interpolation procedure. In general, good agreement has been observed for electrons, and the difference (%) in Z eff between the results of the direct and the interpolation method was found to be energy range from 10 keV to 1 MeV. More specifically, results of the two methods were found to agree well (Dif. energy region with respect to the total electron interaction. On the other hand, values for Z eff calculated using both methods for protons and alpha particles generally agree with each other in the high-energy region above 10 MeV.

A Direct Method of Hamiltonian Structure

International Nuclear Information System (INIS)

Li Qi; Chen Dengyuan; Su Shuhua

2011-01-01

A direct method of constructing the Hamiltonian structure of the soliton hierarchy with self-consistent sources is proposed through computing the functional derivative under some constraints. The Hamiltonian functional is related with the conservation densities of the corresponding hierarchy. Three examples and their two reductions are given. (general)

Comparative study of analytical methods by direct and first-derivative UV spectrophotometry for evaluation of losartan potassium in capsules

Directory of Open Access Journals (Sweden)

Rudy Bonfilio

2010-03-01

Full Text Available Losartan potassium is an antihypertensive non-peptide agent, which exerts its action by specific blockade of angiotensin II receptors. The aim of the present study was the validation and application of analytical methods for the quality control of losartan potassium 50 mg in pharmaceutical capsules, using direct and first-derivative UV spectrophotometry. Based on losartan potassium spectrophotometric characteristics, a signal at 205 nm of the zero-order spectrum and a signal at 234 nm of the first-derivative spectrum, were found adequate for quantification. The results were used to compare these instrumental techniques. The linearity between the signals and concentrations of losartan potassium in the ranges of 3.0-7.0 mg L-1 and 6.0-14.0 mg L-1 for direct and first-derivative spectrophotometry in aqueous solutions, respectively, presented a correlation coefficient (r of 0.9999 in both cases. The methods were applied for losartan potassium in capsule dosage obtained from local pharmacies, and were shown to be efficient, easy to apply and low cost. These methods do not use polluting reagents and require relatively inexpensive equipment.O losartano potássico é um agente anti-hipertensivo não peptídico, que exerce sua ação por bloqueio específico dos receptores da angiotensina II. Este trabalho propôs a validação e aplicação de métodos analíticos orientados ao controle de qualidade de losartano potássico 50 mg na forma farmacêutica cápsula, utilizando a espectrofotometria direta e derivada de primeira ordem na região do UV. Baseado nas características espectrofotométricas de losartano potássico, um sinal a 205 nm do espectro de ordem zero e um sinal a 234 nm do espectro de primeira derivada foram adequados para a quantificação. Os resultados foram usados para comparar essas duas técnicas instrumentais. O coeficiente de correlação entre as respostas e as concentrações de losartano potássico na faixa de 3,0-7,0 mg L-1 e 6

Multi-frequency direct sampling method in inverse scattering problem

Science.gov (United States)

Kang, Sangwoo; Lambert, Marc; Park, Won-Kwang

2017-10-01

We consider the direct sampling method (DSM) for the two-dimensional inverse scattering problem. Although DSM is fast, stable, and effective, some phenomena remain unexplained by the existing results. We show that the imaging function of the direct sampling method can be expressed by a Bessel function of order zero. We also clarify the previously unexplained imaging phenomena and suggest multi-frequency DSM to overcome traditional DSM. Our method is evaluated in simulation studies using both single and multiple frequencies.

THE NEW EU ACCOUNTING DIRECTIVE – A COMPARATION OF REPORTING REQUIREMENTS

Directory of Open Access Journals (Sweden)

MARIUS DEAC

2014-05-01

Full Text Available The adoption of Directive 2013/34/EU constitutes the materialization of a modernization process of the Directive 78/660/EEC and Directive 83/349/EEC that has started in 2009. The new accounting directive replaces the two accounting directives and sets the requirements for both individual and consolidated financial statements. It also introduces a new category of entities “micro-undertakings” in order to implement the requirements of Directive 2012/6/EU. The paper tries to summarize and compare the typologies of enterprises and groups defined in the old and new accounting directives as well as in the Romanian accounting system (RAS. It also compares the requirements of both the new and the old accounting directives as well as RAS regarding the structure and presentation of the annual financial statements. European Union (EU wide, about 99% of the enterprises fall into micro and small categories and might benefit from the simplifications of preparation and publication requirements of the annual financial statements. They will also be exempted from the requirements of auditing their financial statements. Only 1.21% of the enterprises in Europe will be classified as medium and large and will be required to prepare and publish a full set of annual financial statements and to audit their financial statements. If Romania will opt for reducing the administrative burdens for micro entities and implement simplifications for micro-entities as they were defined in the EU directive 2013/34/EU, the thresholds would have to be dramatically increased and many more enterprises will be reclassified as micro instead of small or medium enterprises.

Directional fractal signature methods for trabecular bone texture in hand radiographs: Data from the Osteoarthritis Initiative

Energy Technology Data Exchange (ETDEWEB)

Wolski, M., E-mail: marcin.wolski@curtin.edu.au; Podsiadlo, P.; Stachowiak, G. W. [Tribology Laboratory, School of Civil and Mechanical Engineering, Curtin University, Bentley, Western Australia 6102 (Australia)

2014-08-15

Purpose: To develop directional fractal signature methods for the analysis of trabecular bone (TB) texture in hand radiographs. Problems associated with the small size of hand bones and the orientation of fingers were addressed. Methods: An augmented variance orientation transform (AVOT) and a quadrant rotating grid (QRG) methods were developed. The methods calculate fractal signatures (FSs) in different directions. Unlike other methods they have the search region adjusted according to the size of bone region of interest (ROI) to be analyzed and they produce FSs defined with respect to any chosen reference direction, i.e., they work for arbitrary orientation of fingers. Five parameters at scales ranging from 2 to 14 pixels (depending on image size and method) were derived from rose plots of Hurst coefficients, i.e., FS in dominating roughness (FS{sub Sta}), vertical (FS{sub V}) and horizontal (FS{sub H}) directions, aspect ratio (StrS), and direction signatures (StdS), respectively. The accuracy in measuring surface roughness and isotropy/anisotropy was evaluated using 3600 isotropic and 800 anisotropic fractal surface images of sizes between 20 × 20 and 64 × 64 pixels. The isotropic surfaces had FDs ranging from 2.1 to 2.9 in steps of 0.1, and the anisotropic surfaces had two dominating directions of 30° and 120°. The methods were used to find differences in hand TB textures between 20 matched pairs of subjects with (cases: approximate Kellgren-Lawrence (KL) grade ≥2) and without (controls: approximate KL grade <2) radiographic hand osteoarthritis (OA). The OA Initiative public database was used and 20 × 20 pixel bone ROIs were selected on 5th distal and middle phalanges. The performance of the AVOT and QRG methods was compared against a variance orientation transform (VOT) method developed earlier [M. Wolski, P. Podsiadlo, and G. W. Stachowiak, “Directional fractal signature analysis of trabecular bone: evaluation of different methods to detect early

Implementation of direct LSC method for diesel samples on the fuel market.

Science.gov (United States)

Krištof, Romana; Hirsch, Marko; Kožar Logar, Jasmina

2014-11-01

The European Union develops common EU policy and strategy on biofuels and sustainable bio-economy through several documents. The encouragement of biofuel's consumption is therefore the obligation of each EU member state. The situation in Slovenian fuel market is presented and compared with other EU countries in the frame of prescribed values from EU directives. Diesel is the most common fuel for transportation needs in Slovenia. The study was therefore performed on diesel. The sampling net was determined in accordance with the fuel consumption statistics of the country. 75 Sampling points were located on different types of roads. The quantity of bio-component in diesel samples was determined by direct LSC method through measurement of C-14 content. The measured values were in the range from 0 up to nearly 6 mass percentage of bio-component in fuel. The method has proved to be appropriate, suitable and effective for studies on the real fuel market. Copyright © 2014 Elsevier Ltd. All rights reserved.

Direct methods in protein crystallography.

Science.gov (United States)

Karle, J

1989-11-01

It is pointed out that the 'direct methods' of phase determination for small-structure crystallography do not have immediate applicability to macromolecular structures. The term 'direct methods in macromolecular crystallography' is suggested to categorize a spectrum of approaches to macromolecular structure determination in which the analyses are characterized by the use of two-phase and higher-order-phase invariants. The evaluation of the invariants is generally obtained by the use of heavy-atom techniques. The results of a number of the more recent algebraic and probabilistic studies involving isomorphous replacement and anomalous dispersion thus become valid subjects for discussion here. These studies are described and suggestions are also presented concerning future applicability. Additional discussion concerns the special techniques of filtering, the use of non-crystallographic symmetry, some features of maximum entropy and attempts to apply phase-determining formulas to the refinement of macromolecular structure. It is noted that, in addition to the continuing remarkable progress in macromolecular crystallography based on the traditional applications of isomorphous replacement and anomalous dispersion, recent valuable advances have been made in the application of non-crystallographic symmetry, in particular, to virus structures and in applications of filtering. Good progress has also been reported in the application of exact linear algebra to multiple-wavelength anomalous-dispersion investigations of structures containing anomalous scatterers of only moderate scattering power.

Taxation and Gender Equity: A Comparative Analysis of Direct and ...

International Development Research Centre (IDRC) Digital Library (Canada)

2010-06-10

Jun 10, 2010 ... Taxation and Gender Equity: A Comparative Analysis of Direct and Indirect Taxes in Developing and Developed Countries ... This highly original book is essential reading for everyone concerned with equality in taxation.

A novel method for unsteady flow field segmentation based on stochastic similarity of direction

Science.gov (United States)

Omata, Noriyasu; Shirayama, Susumu

2018-04-01

Recent developments in fluid dynamics research have opened up the possibility for the detailed quantitative understanding of unsteady flow fields. However, the visualization techniques currently in use generally provide only qualitative insights. A method for dividing the flow field into physically relevant regions of interest can help researchers quantify unsteady fluid behaviors. Most methods at present compare the trajectories of virtual Lagrangian particles. The time-invariant features of an unsteady flow are also frequently of interest, but the Lagrangian specification only reveals time-variant features. To address these challenges, we propose a novel method for the time-invariant spatial segmentation of an unsteady flow field. This segmentation method does not require Lagrangian particle tracking but instead quantitatively compares the stochastic models of the direction of the flow at each observed point. The proposed method is validated with several clustering tests for 3D flows past a sphere. Results show that the proposed method reveals the time-invariant, physically relevant structures of an unsteady flow.

A Comparative Characterization of the HPA-MCM-48 Type Catalysts Produced by the Direct Hydrothermal and Room Temperature Synthesis Methods

International Nuclear Information System (INIS)

Gucbilmez, Y.; Calis, I.; Yargic, A. S.

2012-01-01

MCM-48 type support materials synthesized by the direct hydrothermal synthesis (HTS) and room temperature synthesis (RTS) methods were incorporated with tungstophosphoric acid (TPA) in the range of 10-40 wt% by using a wet impregnation technique in methanol solutions. Resulting HPA-MCM-48 catalysts were characterized by the XRD, Nitrogen Physisorption, SEM, TEM, EDS, and FT-IR methods in order to determine the effects of different initial synthesis conditions on the catalyst properties. RTS samples were found to have better crystalline structures, higher BET surface areas, and higher BJH pore volumes than HTS samples. They also had slightly higher TPA incorporation, except for the 40 wt% samples, as evidenced by the EDS results. Keggin ion structure was preserved, for both methods, even at the highest acid loading of 40 wt%. It was concluded that the simpler and more economical RTS method was more successful than the HTS method for hetero poly acid incorporation into MCM-48 type materials

Novel Direction Of Arrival Estimation Method Based on Coherent Accumulation Matrix Reconstruction

Directory of Open Access Journals (Sweden)

Li Lei

2015-04-01

Full Text Available Based on coherent accumulation matrix reconstruction, a novel Direction Of Arrival (DOA estimation decorrelation method of coherent signals is proposed using a small sample. First, the Signal to Noise Ratio (SNR is improved by performing coherent accumulation operation on an array of observed data. Then, according to the structure characteristics of the accumulated snapshot vector, the equivalent covariance matrix, whose rank is the same as the number of array elements, is constructed. The rank of this matrix is proved to be determined just by the number of incident signals, which realize the decorrelation of coherent signals. Compared with spatial smoothing method, the proposed method performs better by effectively avoiding aperture loss with high-resolution characteristics and low computational complexity. Simulation results demonstrate the efficiency of the proposed method.

One-Step Direct Return Method For Mohr-Coulomb Plasticity

DEFF Research Database (Denmark)

Clausen, Johan; Damkilde, Lars; Andersen, Lars

2004-01-01

A new return method for the Mohr-Coulomb yield criteria is presented. The idea is to transform the problem into the principal direction and thereby achieve very simple formulas for calculating the elastic return stresses.......A new return method for the Mohr-Coulomb yield criteria is presented. The idea is to transform the problem into the principal direction and thereby achieve very simple formulas for calculating the elastic return stresses....

Study The Validity of The Direct Mathematical Method For Calculation The Total Efficiency Using Point And Disk Sources

International Nuclear Information System (INIS)

Hagag, O.M.; Nafee, S.S.; Naeem, M.A.; El Khatib, A.M.

2011-01-01

The direct mathematical method has been developed for calculating the total efficiency of many cylindrical gamma detectors, especially HPGe and NaI detector. Different source geometries are considered (point and disk). Further into account is taken of gamma attenuation from detector window or any interfacing absorbing layer. Results are compared with published experimental data to study the validity of the direct mathematical method to calculate total efficiency for any gamma detector size.

Stem cell monitoring with a direct or indirect labeling method

Energy Technology Data Exchange (ETDEWEB)

Kim, Min Hwan; Lee, Yong Jin [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul (Korea, Republic of)

2016-12-15

The molecular imaging techniques allow monitoring of the transplanted cells in the same individuals over time, from early localization to the survival, migration, and differentiation. Generally, there are two methods of stem cell labeling: direct and indirect labeling methods. The direct labeling method introduces a labeling agent into the cell, which is stably incorporated or attached to the cells prior to transplantation. Direct labeling of cells with radionuclides is a simple method with relatively fewer adverse events related to genetic responses. However, it can only allow short-term distribution of transplanted cells because of the decreasing imaging signal with radiodecay, according to the physical half-lives, or the signal becomes more diffuse with cell division and dispersion. The indirect labeling method is based on the expression of a reporter gene transduced into the cell before transplantation, which is then visualized upon the injection of an appropriate probe or substrate. In this review, various imaging strategies to monitor the survival and behavior change of transplanted stem cells are covered. Taking these new approaches together, the direct and indirect labeling methods may provide new insights on the roles of in vivo stem cell monitoring, from bench to bedside.

Free thyroxin by radioimmunoassay: evaluation of a new direct method involving a radiolabeled thyroxin analog

International Nuclear Information System (INIS)

Kubasik, N.P.; Lundberg, P.A.; Brodows, R.G.; Hallauer, G.D.; Same, D.G.; Lindstedt, G.; Bengtsson, C.; Nystroem, E.

1983-01-01

The first performance evaluation of a new direct method for free thyroxin (T4) in serum by radioimmunoassay, with use of coated tubes and a radioiodinated T4 analog (Diagnostic Products Corp.) is presented. The assay is precise and robust: within-run imprecision (CV), 3.1-6.6%; between-run imprecision, 4.0-7.9%; no demonstrable variation between technologists irrespective of experience with the method. No outliers were observed when we compared the free T4 results with serum total T4. Reference values are reported for a total of 1243 euthyroid subjects; there was no significant age effect on serum free T4 in women 26 to 72 years old. The biological variation was about +/- 35% of the mean (2 SD). Free T4 results are the same for serum and plasma. The assay performs well in hypothyroidism and hyperthyroidism, and distinguishes individuals with thyroid disease from normal individuals. Free T4 values in women taking oral contraceptives are normal. Depressed results were often observed in acute nonthyroidal illness and continuing pregnancy. These results were directly comparable with those of another commercial direct radiolabeled-T4 analog kit for free T4

Direct 125I-radioligand assays for serum progesterone compared with assays involving extraction of serum

International Nuclear Information System (INIS)

Ratcliffe, W.A.; Corrie, J.E.T.; Dalziel, A.H.; Macpherson, J.S.

1982-01-01

Two direct radioimmunoassays for progesterone in 50 μL of unextracted serum or plasma with assays involving extraction of serum were compared. The direct assays include the use of either danazol at pH 7.4 or 8-anilino-1-naphthalenesulfonic acid at pH 4.0 to displace progesterone from serum binding-proteins. Progesterone is then assayed by using an antiserum to a progesterone 11α-hemisuccinyl conjugate and the radioligand 125 I-labeled progesterone 11α-glucuronyl tyramine, with separation by double-antibody techniques. Direct assays with either displacing agent gave good analytical recovery of progesterone added to human serum, and progesterone values for patients' specimens correlated well (r > 0.96) with results of assays involving extraction of serum. Precision was similar with each displacing agent over the working range 2.5-100 nmol/L and superior to that of extraction assays. We conclude that these direct assays of progesterone are analytically valid and more robust, precise, and technically convenient than many conventional methods involving extraction of serum

Lessons from comparative effectiveness research methods development projects funded under the Recovery Act.

Science.gov (United States)

Zurovac, Jelena; Esposito, Dominick

2014-11-01

The American Recovery and Reinvestment Act of 2009 (ARRA) directed nearly US$29.2 million to comparative effectiveness research (CER) methods development. To help inform future CER methods investments, we describe the ARRA CER methods projects, identify barriers to this research and discuss the alignment of topics with published methods development priorities. We used several existing resources and held discussions with ARRA CER methods investigators. Although funded projects explored many identified priority topics, investigators noted that much work remains. For example, given the considerable investments in CER data infrastructure, the methods development field can benefit from additional efforts to educate researchers about the availability of new data sources and about how best to apply methods to match their research questions and data.

Effective Alternating Direction Optimization Methods for Sparsity-Constrained Blind Image Deblurring

Directory of Open Access Journals (Sweden)

Naixue Xiong

2017-01-01

Full Text Available Single-image blind deblurring for imaging sensors in the Internet of Things (IoT is a challenging ill-conditioned inverse problem, which requires regularization techniques to stabilize the image restoration process. The purpose is to recover the underlying blur kernel and latent sharp image from only one blurred image. Under many degraded imaging conditions, the blur kernel could be considered not only spatially sparse, but also piecewise smooth with the support of a continuous curve. By taking advantage of the hybrid sparse properties of the blur kernel, a hybrid regularization method is proposed in this paper to robustly and accurately estimate the blur kernel. The effectiveness of the proposed blur kernel estimation method is enhanced by incorporating both the L 1 -norm of kernel intensity and the squared L 2 -norm of the intensity derivative. Once the accurate estimation of the blur kernel is obtained, the original blind deblurring can be simplified to the direct deconvolution of blurred images. To guarantee robust non-blind deconvolution, a variational image restoration model is presented based on the L 1 -norm data-fidelity term and the total generalized variation (TGV regularizer of second-order. All non-smooth optimization problems related to blur kernel estimation and non-blind deconvolution are effectively handled by using the alternating direction method of multipliers (ADMM-based numerical methods. Comprehensive experiments on both synthetic and realistic datasets have been implemented to compare the proposed method with several state-of-the-art methods. The experimental comparisons have illustrated the satisfactory imaging performance of the proposed method in terms of quantitative and qualitative evaluations.

Numerical simulation of direct methanol fuel cells using lattice Boltzmann method

Energy Technology Data Exchange (ETDEWEB)

Delavar, Mojtaba Aghajani; Farhadi, Mousa; Sedighi, Kurosh [Faculty of Mechanical Engineering, Babol University of Technology, Babol, P.O. Box 484 (Iran)

2010-09-15

In this study Lattice Boltzmann Method (LBM) as an alternative of conventional computational fluid dynamics method is used to simulate Direct Methanol Fuel Cell (DMFC). A two dimensional lattice Boltzmann model with 9 velocities, D2Q9, is used to solve the problem. The computational domain includes all seven parts of DMFC: anode channel, catalyst and diffusion layers, membrane and cathode channel, catalyst and diffusion layers. The model has been used to predict the flow pattern and concentration fields of different species in both clear and porous channels to investigate cell performance. The results have been compared well with results in literature for flow in porous and clear channels and cell polarization curves of the DMFC at different flow speeds and feed methanol concentrations. (author)

Comparative determination of sucrose content in sugar beet by polarimetric and isotope dilution methods

Energy Technology Data Exchange (ETDEWEB)

Malec, K; Szuchnik, A [Institute of Nuclear Research, Warsaw (Poland); Rydel, S; Walerianaczyk, E [Instytut Przemyslu Cukrowniczego, Warsaw (Poland)

1976-01-01

The comparative determination of sucrose content in sugar beets has been investigated by following methods: polarimetric, direct isotope dilution and double carrier-isotope dilution analysis. Basing upon the obtained results it has been ascertained, that in the case of worse quality beets the polarimetric determinations differ greatly from isotopic data.

Estimating Steatosis Prevalence in Overweight and Obese Children: Comparison of Bayesian Small Area and Direct Methods

Directory of Open Access Journals (Sweden)

Hamid Reza Khalkhali

2016-09-01

Full Text Available Background Often, there is no access to sufficient sample size to estimate the prevalence using the method of direct estimator in all areas. The aim of this study was to compare small area’s Bayesian method and direct method in estimating the prevalence of steatosis in obese and overweight children. Materials and Methods: In this cross-sectional study, was conducted on 150 overweight and obese children aged 2 to 15 years referred to the Children's digestive clinic of Urmia University of Medical Sciences- Iran, in 2013. After Body mass index (BMI calculation, children with overweight and obese were assessed in terms of primary tests of obesity screening. Then children with steatosis confirmed by abdominal Ultrasonography, were referred to the laboratory for doing further tests. Steatosis prevalence was estimated by direct and Bayesian method and their efficiency were evaluated using mean-square error Jackknife method. The study data was analyzed using the open BUGS3.1.2 and R2.15.2 software. Results: The findings indicated that estimation of steatosis prevalence in children using Bayesian and direct methods were between 0.3098 to 0.493, and 0.355 to 0.560 respectively, in Health Districts; 0.3098 to 0.502, and 0.355 to 0.550 in Education Districts; 0.321 to 0.582, and 0.357 to 0.615 in age groups; 0.313 to 0.429, and 0.383 to 0.536 in sex groups. In general, according to the results, mean-square error of Bayesian estimation was smaller than direct estimation (P

Markov chain Monte Carlo methods in directed graphical models

DEFF Research Database (Denmark)

Højbjerre, Malene

Directed graphical models present data possessing a complex dependence structure, and MCMC methods are computer-intensive simulation techniques to approximate high-dimensional intractable integrals, which emerge in such models with incomplete data. MCMC computations in directed graphical models h...

A comparison of EGFR mutation testing methods in lung carcinoma: direct sequencing, real-time PCR and immunohistochemistry.

Directory of Open Access Journals (Sweden)

Bárbara Angulo

Full Text Available The objective of this study is to compare two EGFR testing methodologies (a commercial real-time PCR kit and a specific EGFR mutant immunohistochemistry, with direct sequencing and to investigate the limit of detection (LOD of both PCR-based methods. We identified EGFR mutations in 21 (16% of the 136 tumours analyzed by direct sequencing. Interestingly, the Therascreen EGFR Mutation Test kit was able to characterize as wild-type one tumour that could not be analyzed by direct sequencing of the PCR product. We then compared the LOD of the kit and that of direct sequencing using the available mutant tumours. The kit was able to detect the presence of a mutation in a 1% dilution of the total DNA in nine of the 18 tumours (50%, which tested positive with the real-time quantitative PCR method. In all cases, EGFR mutation was identified at a dilution of 5%. Where the mutant DNA represented 30% of the total DNA, sequencing was able to detect mutations in 12 out of 19 cases (63%. Additional experiments with genetically defined standards (EGFR ΔE746-A750/+ and EGFR L858R/+ yielded similar results. Immunohistochemistry (IHC staining with exon 19-specific antibody was seen in eight out of nine cases with E746-A750del detected by direct sequencing. Neither of the two tumours with complex deletions were positive. Of the five L858R-mutated tumours detected by the PCR methods, only two were positive for the exon 21-specific antibody. The specificity was 100% for both antibodies. The LOD of the real-time PCR method was lower than that of direct sequencing. The mutation specific IHC produced excellent specificity.

Comparing NASA and ESA Cost Estimating Methods for Human Missions to Mars

Science.gov (United States)

Hunt, Charles D.; vanPelt, Michel O.

2004-01-01

To compare working methodologies between the cost engineering functions in NASA Marshall Space Flight Center (MSFC) and ESA European Space Research and Technology Centre (ESTEC), as well as to set-up cost engineering capabilities for future manned Mars projects and other studies which involve similar subsystem technologies in MSFC and ESTEC, a demonstration cost estimate exercise was organized. This exercise was a direct way of enhancing not only cooperation between agencies but also both agencies commitment to credible cost analyses. Cost engineers in MSFC and ESTEC independently prepared life-cycle cost estimates for a reference human Mars project and subsequently compared the results and estimate methods in detail. As a non-sensitive, public domain reference case for human Mars projects, the Mars Direct concept was chosen. In this paper the results of the exercise are shown; the differences and similarities in estimate methodologies, philosophies, and databases between MSFC and ESTEC, as well as the estimate results for the Mars Direct concept. The most significant differences are explained and possible estimate improvements identified. In addition, the Mars Direct plan and the extensive cost breakdown structure jointly set-up by MSFC and ESTEC for this concept are presented. It was found that NASA applied estimate models mainly based on historic Apollo and Space Shuttle cost data, taking into account the changes in technology since then. ESA used models mostly based on European satellite and launcher cost data, taking into account the higher equipment and testing standards for human space flight. Most of NASA's and ESA s estimates for the Mars Direct case are comparable, but there are some important, consistent differences in the estimates for: 1) Large Structures and Thermal Control subsystems; 2) System Level Management, Engineering, Product Assurance and Assembly, Integration and Test/Verification activities; 3) Mission Control; 4) Space Agency Program Level

Sleep can eliminate list-method directed forgetting.

Science.gov (United States)

Abel, Magdalena; Bäuml, Karl-Heinz T

2013-05-01

Recent work suggests a link between sleep and memory consolidation, indicating that sleep in comparison to wakefulness stabilizes memories. However, relatively little is known about how sleep affects forgetting. Here we examined whether sleep influences directed forgetting, the finding that people can intentionally forget obsolete memories when cued to do so. We applied the list-method directed forgetting task and assessed memory performance after 3 delay intervals. Directed forgetting was present after a short 20-min delay and after a 12-hr delay filled with diurnal wakefulness; in contrast, the forgetting was absent after a 12-hr delay that included regular nocturnal sleep. Successful directed forgetting after a delay thus can depend on whether sleep or wakefulness follows upon encoding: When wakefulness follows upon encoding, the forgetting can be successful; when sleep follows upon encoding, no forgetting may arise. Connections of the results to recent studies on the interplay between forgetting and sleep are discussed.

Integration of the ATHENA mirror modules: development of indirect and x-ray direct AIT methods

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Vernani, Dervis; Blum, Steffen; Seure, Thibault; Bavdaz, Marcos; Wille, Eric; Schaeffer, Uwe; Lièvre, Nicolas; Nazeeruddin, Adeeb; Barrière, Nicolas M.; Collon, Maximilien J.; Cibik, Levent; Krumrey, Michael; Müller, Peter; Burwitz, Vadim

2017-08-01

Within the ATHENA optics technology plan, activities are on-going for demonstrating the feasibility of the mirror module Assembly Integration and Testing (AIT). Each mirror module has to be accurately attached to the mirror structure by means of three isostatic mounts ensuring minimal distortion under environmental loads. This work reports on the status of one of the two parallel activities initiated by ESA to address this demanding task. In this study awarded to the industrial consortium, the integration relies on opto-mechanical metrology and direct X-ray alignment. For the first or "indirect" method the X-ray alignment results are accurately referenced, by means of a laser tracking system, to optical fiducial targets mounted on the mirror modules and finally linked to the mirror structure coordinate system. With the second or "direct" method the alignment is monitored in the X-ray domain, providing figures of merit directly comparable to the final performance. The integration being designed and here presented, foresees combining the indirect method to the X-ray direct method. The characterization of the single mirror modules is planned at PTB's X-ray Parallel Beam Facility (XPBF 2.0) at BESSY II, and the integration and testing campaign at Panter. It is foreseen to integrate and test a demonstrator with two real mirror modules manufactured by cosine.

Sensitivity assessment of direct method for diagnosis of Trichomonas vaginalis in comparison with Dorset Culture media

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ebrahim badparva

2010-04-01

Full Text Available Trichomonas vaginalis is a flagellate protozoan that lives in the genital tract and causes trichomoniasis in women. About 200 million people all over the world are infected with T. vaginalis. There are various methods with different sensitivity and specificity for detection of this parasite, that one of them is direct smear of vaginal secretions which is simpler, rapid and cheaper than other diagnostic methods. Materials and Methods: Demographic data was gathered by a questionnaire which contained different variables. Vaginal secretions samples were taken by spicolum and two swaps that maintained in glucose solution in separate tubes from 160 women referred to health centers of Khorramabad. One of the vaginal samples was examined by direct smear in saline solution and the other was cultured in Dorse medium. Results: Of 160 women suspected of trichomoniasis, 11.8% and 18.75% were positive by direct smear and culture respectively. The sensitivity of the direct method was 63.3%. Our findings indicated that 30% of the infected women belonged to the 31 – 35 age group, which had the most relative frequency of positive cases. Most of the patients (43% were illiterate or had elementary educational level. Conclussion: The sensivity of direct method is 63% in compare to culture ( as a Gold standard , which is ralatively low . Although the efficacy of this test could be imporved by shortening the elapsed time between sampling and examination , use of skilled microscopists , and different samples , but we recommend that more sensitive methods such as culture and PCR should be used .

The Rating of Direct and Semi-Direct Oral Proficiency Interviews: Comparing Performance at Lower Proficiency Levels.

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Kenyon, Dorry M.; Tschirner, Erwin

2000-01-01

Reports on a study comparing student performances and test reliabilities for the German Speaking Test, a semi-direct tape-mediated oral proficiency test (GST) developed by the Center for Applied Linguistics, and the American Council on the Teaching of Foreign Languages Oral Proficiency Interviews. (Author/VWL)

Simple Moving Voltage Average Incremental Conductance MPPT Technique with Direct Control Method under Nonuniform Solar Irradiance Conditions

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Amjad Ali

2015-01-01

Full Text Available A new simple moving voltage average (SMVA technique with fixed step direct control incremental conductance method is introduced to reduce solar photovoltaic voltage (VPV oscillation under nonuniform solar irradiation conditions. To evaluate and validate the performance of the proposed SMVA method in comparison with the conventional fixed step direct control incremental conductance method under extreme conditions, different scenarios were simulated. Simulation results show that in most cases SMVA gives better results with more stability as compared to traditional fixed step direct control INC with faster tracking system along with reduction in sustained oscillations and possesses fast steady state response and robustness. The steady state oscillations are almost eliminated because of extremely small dP/dV around maximum power (MP, which verify that the proposed method is suitable for standalone PV system under extreme weather conditions not only in terms of bus voltage stability but also in overall system efficiency.

Simple Sample Preparation Method for Direct Microbial Identification and Susceptibility Testing From Positive Blood Cultures

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Hong-wei Pan

2018-03-01

Full Text Available Rapid identification and determination of the antibiotic susceptibility profiles of the infectious agents in patients with bloodstream infections are critical steps in choosing an effective targeted antibiotic for treatment. However, there has been minimal effort focused on developing combined methods for the simultaneous direct identification and antibiotic susceptibility determination of bacteria in positive blood cultures. In this study, we constructed a lysis-centrifugation-wash procedure to prepare a bacterial pellet from positive blood cultures, which can be used directly for identification by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS and antibiotic susceptibility testing by the Vitek 2 system. The method was evaluated using a total of 129 clinical bacteria-positive blood cultures. The whole sample preparation process could be completed in <15 min. The correct rate of direct MALDI-TOF MS identification was 96.49% for gram-negative bacteria and 97.22% for gram-positive bacteria. Vitek 2 antimicrobial susceptibility testing of gram-negative bacteria showed an agreement rate of antimicrobial categories of 96.89% with a minor error, major error, and very major error rate of 2.63, 0.24, and 0.24%, respectively. Category agreement of antimicrobials against gram-positive bacteria was 92.81%, with a minor error, major error, and very major error rate of 4.51, 1.22, and 1.46%, respectively. These results indicated that our direct antibiotic susceptibility analysis method worked well compared to the conventional culture-dependent laboratory method. Overall, this fast, easy, and accurate method can facilitate the direct identification and antibiotic susceptibility testing of bacteria in positive blood cultures.

Rapid method for direct identification of bacteria in urine and blood culture samples by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: intact cell vs. extraction method.

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Ferreira, L; Sánchez-Juanes, F; Muñoz-Bellido, J L; González-Buitrago, J M

2011-07-01

Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is a fast and reliable technology for the identification of microorganisms with proteomics approaches. Here, we compare an intact cell method and a protein extraction method before application on the MALDI plate for the direct identification of microorganisms in both urine and blood culture samples from clinical microbiology laboratories. The results show that the intact cell method provides excellent results for urine and is a good initial method for blood cultures. The extraction method complements the intact cell method, improving microorganism identification from blood culture. Thus, we consider that MALDI-TOF MS performed directly on urine and blood culture samples, with the protocols that we propose, is a suitable technique for microorganism identification, as compared with the routine methods used in the clinical microbiology laboratory. © 2010 The Authors. Clinical Microbiology and Infection © 2010 European Society of Clinical Microbiology and Infectious Diseases.

Direct infusion electrospray ionization–ion mobility–mass spectrometry for comparative profiling of fatty acids based on stable isotope labeling

Energy Technology Data Exchange (ETDEWEB)

Leng, Jiapeng, E-mail: jpleng@126.com [Department of Chemical Engineering, North University of China, Taiyuan 030051 (China); Guan, Qing [Department of Head and Neck Surgery, Fudan University Shanghai Cancer Center (FUSCC), Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Sun, Tuanqi, E-mail: tuanqisun@163.com [Department of Head and Neck Surgery, Fudan University Shanghai Cancer Center (FUSCC), Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Wang, Haoyang [National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032 (China); Cui, Jianlan; Liu, Qinghao [Department of Chemical Engineering, North University of China, Taiyuan 030051 (China); Zhang, Zhixu; Zhang, Manyu [Agilent Technologies China Co., Ltd, Shanghai 200080 (China); Guo, Yinlong, E-mail: ylguo@sioc.ac.cn [National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032 (China)

2015-08-05

A rapid method for fatty acids (FAs) comparative profiling based on carboxyl-specific stable isotope labeling (SIL) and direct infusion electrospray ionization–ion mobility–mass spectrometry (ESI–IM–MS) is established. The design of the method takes advantage of the three-dimensional characteristics of IM–MS including drift time, m/z and ion intensity, for comparison of d0-/d6-2,4-dimethoxy-6-piperazin-1-yl pyrimidine (DMPP)-labeled FAs. In particular, without chromatographic separation, the method allowed direct FAs profiling in complex samples due to the advantageous priority of DMPP in signal enhancement as well as the extra resolution that IM–MS offered. Additionally, the d0-/d6-DMPP-labeled FAs showed expected features, including very similar drift times, 6 Da mass deviations, specific reporter ions, similar MS responses, and adherence to the drift time rule regarding the influence of carbon chain length and unsaturation on relative drift times. Therefore, the introduction of isotope analogs minimized the matrix effect and variations in quantification and ensured accurate identification of non-targeted FAs by those typical features. Peak intensity ratios between d0-/d6-DMPP-labeled ions were subsequently used in relative quantification for the detected FAs. The established strategy has been applied successfully in the rapid profiling of trace free FAs between normal and cancerous human thyroid tissues. Sixteen free FAs were found with the increased level with a statistically significant difference (p < 0.05) compared to the normal tissue samples. The integrated SIL technique and ESI–IM–MS are expected to serve as an alternative tool for high-throughput analysis of FAs in complex samples. - Highlights: • A novel method based on IM–MS and SIL was developed for FAs comparative profiling. • Without LC separation, the method allowed direct infusion profiling of FAs in complex samples. • Both of the efficiency and accuracy for FAs analyses

Numerical study of unsteady flows past oscillating airfoils using direct zonal coupling method

International Nuclear Information System (INIS)

Zhang, F.; Khalid, M.

2005-01-01

A direct zonal coupling method was proposed for solving the flows past oscillating airfoils in this study. The entire computational domain was divided into inner and outer zones. The grid in the inner zone is moving with the oscillation of the airfoil, whereas the grid in the outer zone is artificially adjusted to the position consistent with the inner zone grid. The governing equations in the moving frame (the rotation potential energy is included) and those under the stationary frame were applied to inner and outer zones, respectively. By using this kind of treatment, the grid on the zonal interface is 1-to-1 matched. The coupling between the two zones is direct. Both the geometric and flow conservations are entirely satisfied. The NACA0012 and NLR7301 airfoils with oscillations were used as the test cases. The accuracy of the proposed method was demonstrated by the computational results compared with the experimental data.(author)

Direct Linear Transformation Method for Three-Dimensional Cinematography

Science.gov (United States)

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)

Direct identification of microorganisms from positive blood cultures by MALDI-TOF MS using an in-house saponin method.

Science.gov (United States)

Yonetani, Shota; Ohnishi, Hiroaki; Ohkusu, Kiyofumi; Matsumoto, Tetsuya; Watanabe, Takashi

2016-11-01

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a fast and reliable method for the identification of bacteria. A MALDI Sepsityper kit is generally used to prepare samples obtained directly from culture bottles. However, the relatively high cost of this kit is a major obstacle to introducing this method into routine clinical use. In this study, the accuracies of three different preparation methods for rapid direct identification of bacteria from positive blood culture bottles by MALDI-TOF MS analysis were compared. In total, 195 positive bottles were included in this study. Overall, 78.5%, 68.7%, and 76.4% of bacteria were correctly identified to the genus level (score ≥1.7) directly from positive blood cultures using the Sepsityper, centrifugation, and saponin methods, respectively. The identification rates using the Sepsityper and saponin methods were significantly higher than that using the centrifugation method (Sepsityper vs. centrifugation, pdirectly from blood culture bottles, and could be a less expensive alternative to the Sepsityper method. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

A parallel direct-forcing fictitious domain method for simulating microswimmers

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Gao, Tong; Lin, Zhaowu

2017-11-01

We present a 3D parallel direct-forcing fictitious domain method for simulating swimming micro-organisms at small Reynolds numbers. We treat the motile micro-swimmers as spherical rigid particles using the ``Squirmer'' model. The particle dynamics are solved on the moving Larangian meshes that overlay upon a fixed Eulerian mesh for solving the fluid motion, and the momentum exchange between the two phases is resolved by distributing pseudo body-forces over the particle interior regions which constrain the background fictitious fluids to follow the particle movement. While the solid and fluid subproblems are solved separately, no inner-iterations are required to enforce numerical convergence. We demonstrate the accuracy and robustness of the method by comparing our results with the existing analytical and numerical studies for various cases of single particle dynamics and particle-particle interactions. We also perform a series of numerical explorations to obtain statistical and rheological measurements to characterize the dynamics and structures of Squirmer suspensions. NSF DMS 1619960.

EDM 1.0: electron direct methods.

Science.gov (United States)

Kilaas, R; Marks, L D; Own, C S

2005-02-01

A computer program designed to provide a number of quantitative analysis tools for high-resolution imaging and electron diffraction data is described. The program includes basic image manipulation, both real space and reciprocal space image processing, Wiener-filtering, symmetry averaging, methods for quantification of electron diffraction patterns and two-dimensional direct methods. The program consists of a number of sub-programs written in a combination of C++, C and Fortran. It can be downloaded either as GNU source code or as binaries and has been compiled and verified on a wide range of platforms, both Unix based and PC's. Elements of the design philosophy as well as future possible extensions are described.

The Direct Lighting Computation in Global Illumination Methods

Science.gov (United States)

Wang, Changyaw Allen

1994-01-01

Creating realistic images is a computationally expensive process, but it is very important for applications such as interior design, product design, education, virtual reality, and movie special effects. To generate realistic images, state-of-art rendering techniques are employed to simulate global illumination, which accounts for the interreflection of light among objects. In this document, we formalize the global illumination problem into a eight -dimensional integral and discuss various methods that can accelerate the process of approximating this integral. We focus on the direct lighting computation, which accounts for the light reaching the viewer from the emitting sources after exactly one reflection, Monte Carlo sampling methods, and light source simplification. Results include a new sample generation method, a framework for the prediction of the total number of samples used in a solution, and a generalized Monte Carlo approach for computing the direct lighting from an environment which for the first time makes ray tracing feasible for highly complex environments.

Comparison of direct boiling method with commercial kits for extracting fecal microbiome DNA by Illumina sequencing of 16S rRNA tags.

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Peng, Xin; Yu, Ke-Qiang; Deng, Guan-Hua; Jiang, Yun-Xia; Wang, Yu; Zhang, Guo-Xia; Zhou, Hong-Wei

2013-12-01

Low cost and high throughput capacity are major advantages of using next generation sequencing (NGS) techniques to determine metagenomic 16S rRNA tag sequences. These methods have significantly changed our view of microorganisms in the fields of human health and environmental science. However, DNA extraction using commercial kits has shortcomings of high cost and time constraint. In the present study, we evaluated the determination of fecal microbiomes using a direct boiling method compared with 5 different commercial extraction methods, e.g., Qiagen and MO BIO kits. Principal coordinate analysis (PCoA) using UniFrac distances and clustering showed that direct boiling of a wide range of feces concentrations gave a similar pattern of bacterial communities as those obtained from most of the commercial kits, with the exception of the MO BIO method. Fecal concentration by boiling method affected the estimation of α-diversity indices, otherwise results were generally comparable between boiling and commercial methods. The operational taxonomic units (OTUs) determined through direct boiling showed highly consistent frequencies with those determined through most of the commercial methods. Even those for the MO BIO kit were also obtained by the direct boiling method with high confidence. The present study suggested that direct boiling could be used to determine the fecal microbiome and using this method would significantly reduce the cost and improve the efficiency of the sample preparation for studying gut microbiome diversity. © 2013 Elsevier B.V. All rights reserved.

Application of the Method of Direct Solidification for Obtaining New Materials

International Nuclear Information System (INIS)

Grankin, S.S.

2007-01-01

The influence of the method of direct solidification on the formation of the material structure has been considered. The main methods of single crystal growth have been described. A considerable influence of the crystal growth parameters (temperature gradient at the front of solidification and the speed of moving of the front of solidification) on the type of the structure and morphology of single crystals has been shown. The examples of application of the method of direct solidification in experimental and industrial production are showed: production of directly crystallized blades for turbines of nuclear power plants and gas-turbine engines

The Method of Adaptive Comparative Judgement

Science.gov (United States)

Pollitt, Alastair

2012-01-01

Adaptive Comparative Judgement (ACJ) is a modification of Thurstone's method of comparative judgement that exploits the power of adaptivity, but in scoring rather than testing. Professional judgement by teachers replaces the marking of tests; a judge is asked to compare the work of two students and simply to decide which of them is the better.…

Simple Sample Preparation Method for Direct Microbial Identification and Susceptibility Testing From Positive Blood Cultures.

Science.gov (United States)

Pan, Hong-Wei; Li, Wei; Li, Rong-Guo; Li, Yong; Zhang, Yi; Sun, En-Hua

2018-01-01

Rapid identification and determination of the antibiotic susceptibility profiles of the infectious agents in patients with bloodstream infections are critical steps in choosing an effective targeted antibiotic for treatment. However, there has been minimal effort focused on developing combined methods for the simultaneous direct identification and antibiotic susceptibility determination of bacteria in positive blood cultures. In this study, we constructed a lysis-centrifugation-wash procedure to prepare a bacterial pellet from positive blood cultures, which can be used directly for identification by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and antibiotic susceptibility testing by the Vitek 2 system. The method was evaluated using a total of 129 clinical bacteria-positive blood cultures. The whole sample preparation process could be completed in identification was 96.49% for gram-negative bacteria and 97.22% for gram-positive bacteria. Vitek 2 antimicrobial susceptibility testing of gram-negative bacteria showed an agreement rate of antimicrobial categories of 96.89% with a minor error, major error, and very major error rate of 2.63, 0.24, and 0.24%, respectively. Category agreement of antimicrobials against gram-positive bacteria was 92.81%, with a minor error, major error, and very major error rate of 4.51, 1.22, and 1.46%, respectively. These results indicated that our direct antibiotic susceptibility analysis method worked well compared to the conventional culture-dependent laboratory method. Overall, this fast, easy, and accurate method can facilitate the direct identification and antibiotic susceptibility testing of bacteria in positive blood cultures.

Research on direct calibration method of eye-to-hand system of robot

Science.gov (United States)

Hu, Xiaoping; Xie, Ke; Peng, Tao

2013-10-01

In the position-based visual servoing control for robot, the hand-eye calibration is very important because it can affect the control precision of the system. According to the robot with eye-to-hand stereovision system, this paper proposes a direct method of hand-eye calibration. The method utilizes the triangle measuring principle to solve the coordinates in the camera coordinate system of scene point. It calculates the estimated coordinates by the hand-eye calibration equation set which indicates the transformational relation from the robot to the camera coordinate system, and then uses the error of actual and estimated coordinates to establish the objective function. Finally the method substitutes the parameters into the function repeatedly until it converged to optimize the result. The related experiment compared the measured coordinates with the actual coordinates, shows the efficiency and the precision of it.

Two-baryon systems from HAL QCD method and the mirage in the temporal correlation of the direct method

Science.gov (United States)

Iritani, Takumi

2018-03-01

Both direct and HAL QCD methods are currently used to study the hadron interactions in lattice QCD. In the direct method, the eigen-energy of two-particle is measured from the temporal correlation. Due to the contamination of excited states, however, the direct method suffers from the fake eigen-energy problem, which we call the "mirage problem," while the HAL QCD method can extract information from all elastic states by using the spatial correlation. In this work, we further investigate systematic uncertainties of the HAL QCD method such as the quark source operator dependence, the convergence of the derivative expansion of the non-local interaction kernel, and the single baryon saturation, which are found to be well controlled. We also confirm the consistency between the HAL QCD method and the Lüscher's finite volume formula. Based on the HAL QCD potential, we quantitatively confirm that the mirage plateau in the direct method is indeed caused by the contamination of excited states.

A comparative study of reinitialization approaches of the level set method for simulating free-surface flows

Energy Technology Data Exchange (ETDEWEB)

Sufyan, Muhammad; Ngo, Long Cu; Choi, Hyoung Gwon [Seoul National University, Seoul (Korea, Republic of)

2016-04-15

Unstructured grids were used to compare the performance of a direct reinitialization scheme with those of two reinitialization approaches based on the solution of a hyperbolic Partial differential equation (PDE). The problems of moving interface were solved in the context of a finite element method. A least-square weighted residual method was used to discretize the advection equation of the level set method. The benchmark problems of rotating Zalesak's disk, time-reversed single vortex, and two-dimensional sloshing were examined. Numerical results showed that the direct reinitialization scheme performed better than the PDE-based reinitialization approaches in terms of mass conservation, dissipation and dispersion error, and computational time. In the case of sloshing, numerical results were found to be in good agreement with existing experimental data. The direct reinitialization approach consumed considerably less CPU time than the PDE-based simulations for 20 time periods of sloshing. This approach was stable, accurate, and efficient for all the problems considered in this study.

Comparative Study on Uni- and Bi-Directional Fluid Structure Coupling of Wind Turbine Blades

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Mesfin Belayneh Ageze

2017-09-01

Full Text Available The current trends of wind turbine blade designs are geared towards a longer and slender blade with high flexibility, exhibiting complex aeroelastic loadings and instability issues, including flutter; in this regard, fluid-structure interaction (FSI plays a significant role. The present article will conduct a comparative study between uni-directional and bi-directional fluid-structural coupling models for a horizontal axis wind turbine. A full-scale, geometric copy of the NREL 5MW blade with simplified material distribution is considered for simulation. Analytical formulations of the governing relations with appropriate approximation are highlighted, including turbulence model, i.e., Shear Stress Transport (SST k-ω. These analytical relations are implemented using Multiphysics package ANSYS employing Fluent module (Computational Fluid Dynamics (CFD-based solver for the fluid domain and Transient Structural module (Finite Element Analysis-based solver for the structural domain. ANSYS system coupling module also is configured to model the two fluid-structure coupling methods. The rated operational condition of the blade for a full cycle rotation is considered as a comparison domain. In the bi-directional coupling model, the structural deformation alters the angle of attack from the designed values, and by extension the flow pattern along the blade span; furthermore, the tip deflection keeps fluctuating whilst it tends to stabilize in the uni-directional coupling model.

Electron beam directed energy device and methods of using same

Science.gov (United States)

Retsky, Michael W.

2007-10-16

A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

The Independent Evolution Method Is Not a Viable Phylogenetic Comparative Method.

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Randi H Griffin

Full Text Available Phylogenetic comparative methods (PCMs use data on species traits and phylogenetic relationships to shed light on evolutionary questions. Recently, Smaers and Vinicius suggested a new PCM, Independent Evolution (IE, which purportedly employs a novel model of evolution based on Felsenstein's Adaptive Peak Model. The authors found that IE improves upon previous PCMs by producing more accurate estimates of ancestral states, as well as separate estimates of evolutionary rates for each branch of a phylogenetic tree. Here, we document substantial theoretical and computational issues with IE. When data are simulated under a simple Brownian motion model of evolution, IE produces severely biased estimates of ancestral states and changes along individual branches. We show that these branch-specific changes are essentially ancestor-descendant or "directional" contrasts, and draw parallels between IE and previous PCMs such as "minimum evolution". Additionally, while comparisons of branch-specific changes between variables have been interpreted as reflecting the relative strength of selection on those traits, we demonstrate through simulations that regressing IE estimated branch-specific changes against one another gives a biased estimate of the scaling relationship between these variables, and provides no advantages or insights beyond established PCMs such as phylogenetically independent contrasts. In light of our findings, we discuss the results of previous papers that employed IE. We conclude that Independent Evolution is not a viable PCM, and should not be used in comparative analyses.

Comparing the similarity of responses received from studies in Amazon's Mechanical Turk to studies conducted online and with direct recruitment.

Science.gov (United States)

Bartneck, Christoph; Duenser, Andreas; Moltchanova, Elena; Zawieska, Karolina

2015-01-01

Computer and internet based questionnaires have become a standard tool in Human-Computer Interaction research and other related fields, such as psychology and sociology. Amazon's Mechanical Turk (AMT) service is a new method of recruiting participants and conducting certain types of experiments. This study compares whether participants recruited through AMT give different responses than participants recruited through an online forum or recruited directly on a university campus. Moreover, we compare whether a study conducted within AMT results in different responses compared to a study for which participants are recruited through AMT but which is conducted using an external online questionnaire service. The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums. We do, however, argue that this difference is so small that it has no practical consequence. There was no significant difference between running the study within AMT compared to running it with an online questionnaire service. There was no significant difference between results obtained directly from within AMT compared to results obtained in the campus and online forum condition. This may suggest that AMT is a viable and economical option for recruiting participants and for conducting studies as setting up and running a study with AMT generally requires less effort and time compared to other frequently used methods. We discuss our findings as well as limitations of using AMT for empirical studies.

Direct methods for surface X-ray diffraction

International Nuclear Information System (INIS)

Saldin, D. K.; Harder, R.; Shneerson, V. L.; Vogler, H.; Moritz, W.

2000-01-01

We develop of a direct method for surface X-ray diffraction that exploits the holographic feature of a known reference wave from the substrate. A Bayesian analysis of the optimal inference to be made from an incomplete data set suggests a maximum entropy algorithm that balances agreement with the data and other statistical considerations

Theoretical and methodological basis of the comparative historical and legal method development

Directory of Open Access Journals (Sweden)

Д. А. Шигаль

2015-05-01

three research approaches – comparative, historical and legal, comparative historical and legal method is more effective than two separate methods - comparative and historical, and comparative and legal. Epistemological potential of comparative historical and legal method is quite great, and is to ensure the integrity and continuity of the historical and legal knowledge that is carried out in comparative way. Application of this method allows you without breaking the research itself into separate semantic blocks to start and continue it both from the analysis of the "historical" and learning of the "legal". Conclusions. Value of the comparative historical and legal method in the methodology of historical and legal science will be very significant. This can be explained by the fact that this means of knowledge allows to go beyond the known and look from a different angle on already known facts and regularities of the state and legal development. In fact, a comparison in the field of the history of state and law is one of the few methodological tools capable to do away with the stereotype which has been formed in the historical and legal science recently. In addition, comparative historical and legal method can serve as the epicenter of all the research methodology, but the comparative analysis can be the main problem of scientific work with the production of relevant tasks. Comparative historical and legal method as a basis of a study directly causes its scientific novelty, because in the course of comparison of historical and legal objects those of their characteristics and features that were previously unknown are revealed, and new laws are opened.

One directional polarized neutron reflectometry with optimized reference layer method

International Nuclear Information System (INIS)

Masoudi, S. Farhad; Jahromi, Saeed S.

2012-01-01

In the past decade, several neutron reflectometry methods for determining the modulus and phase of the complex reflection coefficient of an unknown multilayer thin film have been worked out among which the method of variation of surroundings and reference layers are of highest interest. These methods were later modified for measurement of the polarization of the reflected beam instead of the measurement of the intensities. In their new architecture, these methods not only suffered from the necessity of change of experimental setup but also another difficulty was added to their experimental implementations. This deficiency was related to the limitations of the technology of the neutron reflectometers that could only measure the polarization of the reflected neutrons in the same direction as the polarization of the incident beam. As the instruments are limited, the theory has to be optimized so that the experiment could be performed. In a recent work, we developed the method of variation of surroundings for one directional polarization analysis. In this new work, the method of reference layer with polarization analysis has been optimized to determine the phase and modulus of the unknown film with measurement of the polarization of the reflected neutrons in the same direction as the polarization of the incident beam.

A copula method for modeling directional dependence of genes

Directory of Open Access Journals (Sweden)

Park Changyi

2008-05-01

Full Text Available Abstract Background Genes interact with each other as basic building blocks of life, forming a complicated network. The relationship between groups of genes with different functions can be represented as gene networks. With the deposition of huge microarray data sets in public domains, study on gene networking is now possible. In recent years, there has been an increasing interest in the reconstruction of gene networks from gene expression data. Recent work includes linear models, Boolean network models, and Bayesian networks. Among them, Bayesian networks seem to be the most effective in constructing gene networks. A major problem with the Bayesian network approach is the excessive computational time. This problem is due to the interactive feature of the method that requires large search space. Since fitting a model by using the copulas does not require iterations, elicitation of the priors, and complicated calculations of posterior distributions, the need for reference to extensive search spaces can be eliminated leading to manageable computational affords. Bayesian network approach produces a discretely expression of conditional probabilities. Discreteness of the characteristics is not required in the copula approach which involves use of uniform representation of the continuous random variables. Our method is able to overcome the limitation of Bayesian network method for gene-gene interaction, i.e. information loss due to binary transformation. Results We analyzed the gene interactions for two gene data sets (one group is eight histone genes and the other group is 19 genes which include DNA polymerases, DNA helicase, type B cyclin genes, DNA primases, radiation sensitive genes, repaire related genes, replication protein A encoding gene, DNA replication initiation factor, securin gene, nucleosome assembly factor, and a subunit of the cohesin complex by adopting a measure of directional dependence based on a copula function. We have compared

Atmosphere Re-Entry Simulation Using Direct Simulation Monte Carlo (DSMC Method

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Francesco Pellicani

2016-05-01

Full Text Available Hypersonic re-entry vehicles aerothermodynamic investigations provide fundamental information to other important disciplines like materials and structures, assisting the development of thermal protection systems (TPS efficient and with a low weight. In the transitional flow regime, where thermal and chemical equilibrium is almost absent, a new numerical method for such studies has been introduced, the direct simulation Monte Carlo (DSMC numerical technique. The acceptance and applicability of the DSMC method have increased significantly in the 50 years since its invention thanks to the increase in computer speed and to the parallel computing. Anyway, further verification and validation efforts are needed to lead to its greater acceptance. In this study, the Monte Carlo simulator OpenFOAM and Sparta have been studied and benchmarked against numerical and theoretical data for inert and chemically reactive flows and the same will be done against experimental data in the near future. The results show the validity of the data found with the DSMC. The best setting of the fundamental parameters used by a DSMC simulator are presented for each software and they are compared with the guidelines deriving from the theory behind the Monte Carlo method. In particular, the number of particles per cell was found to be the most relevant parameter to achieve valid and optimized results. It is shown how a simulation with a mean value of one particle per cell gives sufficiently good results with very low computational resources. This achievement aims to reconsider the correct investigation method in the transitional regime where both the direct simulation Monte Carlo (DSMC and the computational fluid-dynamics (CFD can work, but with a different computational effort.

Scalable force directed graph layout algorithms using fast multipole methods

KAUST Repository

Yunis, Enas Abdulrahman; Yokota, Rio; Ahmadia, Aron

2012-01-01

We present an extension to ExaFMM, a Fast Multipole Method library, as a generalized approach for fast and scalable execution of the Force-Directed Graph Layout algorithm. The Force-Directed Graph Layout algorithm is a physics-based approach

Baryon interactions in lattice QCD: the direct method vs. the HAL QCD potential method

Science.gov (United States)

Iritani, T.; HAL QCD Collaboration

We make a detailed comparison between the direct method and the HAL QCD potential method for the baryon-baryon interactions, taking the $\\Xi\\Xi$ system at $m_\\pi= 0.51$ GeV in 2+1 flavor QCD and using both smeared and wall quark sources. The energy shift $\\Delta E_\\mathrm{eff}(t)$ in the direct method shows the strong dependence on the choice of quark source operators, which means that the results with either (or both) source are false. The time-dependent HAL QCD method, on the other hand, gives the quark source independent $\\Xi\\Xi$ potential, thanks to the derivative expansion of the potential, which absorbs the source dependence to the next leading order correction. The HAL QCD potential predicts the absence of the bound state in the $\\Xi\\Xi$($^1$S$_0$) channel at $m_\\pi= 0.51$ GeV, which is also confirmed by the volume dependence of finite volume energy from the potential. We also demonstrate that the origin of the fake plateau in the effective energy shift $\\Delta E_\\mathrm{eff}(t)$ at $t \\sim 1$ fm can be clarified by a few low-lying eigenfunctions and eigenvalues on the finite volume derived from the HAL QCD potential, which implies that the ground state saturation of $\\Xi\\Xi$($^1$S$_0$) requires $t \\sim 10$ fm in the direct method for the smeared source on $(4.3 \\ \\mathrm{fm})^3$ lattice, while the HAL QCD method does not suffer from such a problem.

Indirect and direct methods for measuring a dynamic throat diameter in a solid rocket motor

Science.gov (United States)

Colbaugh, Lauren

In a solid rocket motor, nozzle throat erosion is dictated by propellant composition, throat material properties, and operating conditions. Throat erosion has a significant effect on motor performance, so it must be accurately characterized to produce a good motor design. In order to correlate throat erosion rate to other parameters, it is first necessary to know what the throat diameter is throughout a motor burn. Thus, an indirect method and a direct method for determining throat diameter in a solid rocket motor are investigated in this thesis. The indirect method looks at the use of pressure and thrust data to solve for throat diameter as a function of time. The indirect method's proof of concept was shown by the good agreement between the ballistics model and the test data from a static motor firing. The ballistics model was within 10% of all measured and calculated performance parameters (e.g. average pressure, specific impulse, maximum thrust, etc.) for tests with throat erosion and within 6% of all measured and calculated performance parameters for tests without throat erosion. The direct method involves the use of x-rays to directly observe a simulated nozzle throat erode in a dynamic environment; this is achieved with a dynamic calibration standard. An image processing algorithm is developed for extracting the diameter dimensions from the x-ray intensity digital images. Static and dynamic tests were conducted. The measured diameter was compared to the known diameter in the calibration standard. All dynamic test results were within +6% / -7% of the actual diameter. Part of the edge detection method consists of dividing the entire x-ray image by an average pixel value, calculated from a set of pixels in the x-ray image. It was found that the accuracy of the edge detection method depends upon the selection of the average pixel value area and subsequently the average pixel value. An average pixel value sensitivity analysis is presented. Both the indirect

Expanding Comparative Literature into Comparative Sciences Clusters with Neutrosophy and Quad-stage Method

Directory of Open Access Journals (Sweden)

Fu Yuhua

2016-08-01

Full Text Available By using Neutrosophy and Quad-stage Method, the expansions of comparative literature include: comparative social sciences clusters, comparative natural sciences clusters, comparative interdisciplinary sciences clusters, and so on. Among them, comparative social sciences clusters include: comparative literature, comparative history, comparative philosophy, and so on; comparative natural sciences clusters include: comparative mathematics, comparative physics, comparative chemistry, comparative medicine, comparative biology, and so on.

Estimation of velocity vector angles using the directional cross-correlation method

DEFF Research Database (Denmark)

Kortbek, Jacob; Jensen, Jørgen Arendt

2006-01-01

and then select the angle with the highest normalized correlation between directional signals. The approach is investigated using Field II simulations and data from the experimental ultrasound scanner RASMUS and a circulating flow rig with a parabolic flow having a peak velocity of 0.3 m/s. A 7 MHz linear array......A method for determining both velocity magnitude and angle in any direction is suggested. The method uses focusing along the velocity direction and cross-correlation for finding the correct velocity magnitude. The angle is found from beamforming directional signals in a number of directions...... transducer is used with a normal transmission of a focused ultrasound field. In the simulations the relative standard deviation of the velocity magnitude is between 0.7% and 7.7% for flow angles between 45 deg and 90 deg. The study showed that angle estimation by directional beamforming can be estimated...

Development of a nursing education program for improving Chinese undergraduates' self-directed learning: A mixed-method study.

Science.gov (United States)

Tao, Ying; Li, Liping; Xu, Qunyan; Jiang, Anli

2015-11-01

This paper demonstrates the establishment of an extra-curricular education program in Chinese context and evaluates its effectiveness on undergraduate nursing students' self-directed learning. Zimmerman's self-directed learning model was used as the theoretical framework for the development of an education program. Mixed-method was applied in this research study. 165 undergraduate students from a nursing college were divided into experimental group (n=32) and control group (n=133). Pre- and post-tests were implemented to evaluate the effectiveness of this education program using the self-directed learning scale of nursing undergraduates. Qualitative interview was undertaken within participants from the experimental group to obtain their insights into the influence of this program. Both quantitative and qualitative analyses showed that the program contributed to nursing students' self-directed learning ability. In the experimental group, the post-test score showed an increase compared with pretest score (plearning activities and influence on learning environment. It can be found in the qualitative analysis that learners benefited from this program. The education program contributes to the improvement of nursing undergraduates' self-directed learning. Various pedagogic methods could be applied for self-directed learning. Copyright © 2015 Elsevier Ltd. All rights reserved.

Scalable force directed graph layout algorithms using fast multipole methods

KAUST Repository

Yunis, Enas Abdulrahman

2012-06-01

We present an extension to ExaFMM, a Fast Multipole Method library, as a generalized approach for fast and scalable execution of the Force-Directed Graph Layout algorithm. The Force-Directed Graph Layout algorithm is a physics-based approach to graph layout that treats the vertices V as repelling charged particles with the edges E connecting them acting as springs. Traditionally, the amount of work required in applying the Force-Directed Graph Layout algorithm is O(|V|2 + |E|) using direct calculations and O(|V| log |V| + |E|) using truncation, filtering, and/or multi-level techniques. Correct application of the Fast Multipole Method allows us to maintain a lower complexity of O(|V| + |E|) while regaining most of the precision lost in other techniques. Solving layout problems for truly large graphs with millions of vertices still requires a scalable algorithm and implementation. We have been able to leverage the scalability and architectural adaptability of the ExaFMM library to create a Force-Directed Graph Layout implementation that runs efficiently on distributed multicore and multi-GPU architectures. © 2012 IEEE.

Direct integration multiple collision integral transport analysis method for high energy fusion neutronics

International Nuclear Information System (INIS)

Koch, K.R.

1985-01-01

A new analysis method specially suited for the inherent difficulties of fusion neutronics was developed to provide detailed studies of the fusion neutron transport physics. These studies should provide a better understanding of the limitations and accuracies of typical fusion neutronics calculations. The new analysis method is based on the direct integration of the integral form of the neutron transport equation and employs a continuous energy formulation with the exact treatment of the energy angle kinematics of the scattering process. In addition, the overall solution is analyzed in terms of uncollided, once-collided, and multi-collided solution components based on a multiple collision treatment. Furthermore, the numerical evaluations of integrals use quadrature schemes that are based on the actual dependencies exhibited in the integrands. The new DITRAN computer code was developed on the Cyber 205 vector supercomputer to implement this direct integration multiple-collision fusion neutronics analysis. Three representative fusion reactor models were devised and the solutions to these problems were studied to provide suitable choices for the numerical quadrature orders as well as the discretized solution grid and to understand the limitations of the new analysis method. As further verification and as a first step in assessing the accuracy of existing fusion-neutronics calculations, solutions obtained using the new analysis method were compared to typical multigroup discrete ordinates calculations

A direct observation method for auditing large urban centers using stratified sampling, mobile GIS technology and virtual environments.

Science.gov (United States)

Lafontaine, Sean J V; Sawada, M; Kristjansson, Elizabeth

2017-02-16

With the expansion and growth of research on neighbourhood characteristics, there is an increased need for direct observational field audits. Herein, we introduce a novel direct observational audit method and systematic social observation instrument (SSOI) for efficiently assessing neighbourhood aesthetics over large urban areas. Our audit method uses spatial random sampling stratified by residential zoning and incorporates both mobile geographic information systems technology and virtual environments. The reliability of our method was tested in two ways: first, in 15 Ottawa neighbourhoods, we compared results at audited locations over two subsequent years, and second; we audited every residential block (167 blocks) in one neighbourhood and compared the distribution of SSOI aesthetics index scores with results from the randomly audited locations. Finally, we present interrater reliability and consistency results on all observed items. The observed neighbourhood average aesthetics index score estimated from four or five stratified random audit locations is sufficient to characterize the average neighbourhood aesthetics. The SSOI was internally consistent and demonstrated good to excellent interrater reliability. At the neighbourhood level, aesthetics is positively related to SES and physical activity and negatively correlated with BMI. The proposed approach to direct neighbourhood auditing performs sufficiently and has the advantage of financial and temporal efficiency when auditing a large city.

Create new research directions in comparative endocrinology from Asia and Oceania.

Science.gov (United States)

Tsutsui, Kazuyoshi

2013-01-15

The Asia and Oceania Society for Comparative Endocrinology (AOSCE) was founded in 1987, when the first congress was held in Nagoya, Japan. The purpose of the AOSCE is to progress scientific activities in the field of comparative endocrinology in Asia and Oceania and to establish a deep relationship among the members. For this purpose, the AOSCE holds a congress or an intercongress symposium every 2 years, which organizes an attractive scientific program covering the latest progress in the broad aspect of comparative endocrinology. 2012 was the 25th anniversary of AOSCE. Our scientific activities have increased dramatically during the past 25 years. The 7th AOSCE congress was held in Kuala Lumpur, Malaysia in 2012. The theme of this congress was "Overcoming challenges in the 21st century". To overcome challenges in the 21st century, we further need to create new research directions in comparative endocrinology from Asia and Oceania. This paper describes a brief history of the AOSCE and also highlights the discovery of gonadotropin-inhibitory hormone (GnIH) and the progress of GnIH research as one of new research directions in comparative endocrinology. In 2000, GnIH was discovered in Japan and now more than 50 laboratories are working on GnIH in the world. The discovery of GnIH has changed our understanding about regulation of the reproductive axis drastically in the past decade. Copyright © 2012 Elsevier Inc. All rights reserved.

Series-parallel method of direct solar array regulation

Science.gov (United States)

Gooder, S. T.

1976-01-01

A 40 watt experimental solar array was directly regulated by shorting out appropriate combinations of series and parallel segments of a solar array. Regulation switches were employed to control the array at various set-point voltages between 25 and 40 volts. Regulation to within + or - 0.5 volt was obtained over a range of solar array temperatures and illumination levels as an active load was varied from open circuit to maximum available power. A fourfold reduction in regulation switch power dissipation was achieved with series-parallel regulation as compared to the usual series-only switching for direct solar array regulation.

Multiple Site-Directed and Saturation Mutagenesis by the Patch Cloning Method.

Science.gov (United States)

Taniguchi, Naohiro; Murakami, Hiroshi

2017-01-01

Constructing protein-coding genes with desired mutations is a basic step for protein engineering. Herein, we describe a multiple site-directed and saturation mutagenesis method, termed MUPAC. This method has been used to introduce multiple site-directed mutations in the green fluorescent protein gene and in the moloney murine leukemia virus reverse transcriptase gene. Moreover, this method was also successfully used to introduce randomized codons at five desired positions in the green fluorescent protein gene, and for simple DNA assembly for cloning.

Advances in a framework to compare bio-dosimetry methods for triage in large-scale radiation events

International Nuclear Information System (INIS)

Flood, Ann Barry; Boyle, Holly K.; Du, Gaixin; Demidenko, Eugene; Williams, Benjamin B.; Swartz, Harold M.; Nicolalde, Roberto J.

2014-01-01

Planning and preparation for a large-scale nuclear event would be advanced by assessing the applicability of potentially available bio-dosimetry methods. Using an updated comparative framework the performance of six bio-dosimetry methods was compared for five different population sizes (100-1 000 000) and two rates for initiating processing of the marker (15 or 15 000 people per hour) with four additional time windows. These updated factors are extrinsic to the bio-dosimetry methods themselves but have direct effects on each method's ability to begin processing individuals and the size of the population that can be accommodated. The results indicate that increased population size, along with severely compromised infrastructure, increases the time needed to triage, which decreases the usefulness of many time intensive dosimetry methods. This framework and model for evaluating bio-dosimetry provides important information for policy-makers and response planners to facilitate evaluation of each method and should advance coordination of these methods into effective triage plans. (authors)

Comparing the similarity of responses received from studies in Amazon's Mechanical Turk to studies conducted online and with direct recruitment.

Directory of Open Access Journals (Sweden)

Christoph Bartneck

Full Text Available Computer and internet based questionnaires have become a standard tool in Human-Computer Interaction research and other related fields, such as psychology and sociology. Amazon's Mechanical Turk (AMT service is a new method of recruiting participants and conducting certain types of experiments. This study compares whether participants recruited through AMT give different responses than participants recruited through an online forum or recruited directly on a university campus. Moreover, we compare whether a study conducted within AMT results in different responses compared to a study for which participants are recruited through AMT but which is conducted using an external online questionnaire service. The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums. We do, however, argue that this difference is so small that it has no practical consequence. There was no significant difference between running the study within AMT compared to running it with an online questionnaire service. There was no significant difference between results obtained directly from within AMT compared to results obtained in the campus and online forum condition. This may suggest that AMT is a viable and economical option for recruiting participants and for conducting studies as setting up and running a study with AMT generally requires less effort and time compared to other frequently used methods. We discuss our findings as well as limitations of using AMT for empirical studies.

Direct determination of scattering time delays using the R-matrix propagation method

International Nuclear Information System (INIS)

Walker, R.B.; Hayes, E.F.

1989-01-01

A direct method for determining time delays for scattering processes is developed using the R-matrix propagation method. The procedure involves the simultaneous generation of the global R matrix and its energy derivative. The necessary expressions to obtain the energy derivative of the S matrix are relatively simple and involve many of the same matrix elements required for the R-matrix propagation method. This method is applied to a simple model for a chemical reaction that displays sharp resonance features. The test results of the direct method are shown to be in excellent agreement with the traditional numerical differentiation method for scattering energies near the resonance energy. However, for sharp resonances the numerical differentiation method requires calculation of the S-matrix elements at many closely spaced energies. Since the direct method presented here involves calculations at only a single energy, one is able to generate accurate energy derivatives and time delays much more efficiently and reliably

Comparative analysis of the quality of biometric methods

OpenAIRE

Filipčík, Jan

2010-01-01

The main objective is to describe and analyze the types of biometric identification and selected biometric methods and identify their strengths and weaknesses compared to the current document type of identification and verification of persons and compared to other biometric methods and then focus on the relationships and support of biometric methods in terms of IS / ICT services. The work will consist of 5 types of biometric methods namely dactyloscopy, hand geometry scanning, facial scanning...

Hybrid Polling Method for Direct Link Communication for IEEE 802.11 Wireless LANs

Directory of Open Access Journals (Sweden)

Woo-Yong Choi

2008-10-01

Full Text Available The direct link communication between STAtions (STAs is one of the techniques to improve the MAC performance of IEEE 802.11 infrastructure networks. For the efficient direct link communication, in the literature, the simultaneous polling method was proposed to allow the multiple direct data communication to be performed simultaneously. However, the efficiency of the simultaneous polling method is affected by the interference condition. To alleviate the problem of the lower polling efficiency with the larger interference range, the hybrid polling method is proposed for the direct link communication between STAs in IEEE 802.11 infrastructure networks. By the proposed polling method, we can integrate the sequential and simultaneous polling methods properly according to the interference condition. Numerical examples are also presented to show the medium access control (MAC performance improvement by the proposed polling method.

Direct numerical simulation of circular-cap bubbles in low viscous liquids using counter diffusion lattice Boltzmann method

Energy Technology Data Exchange (ETDEWEB)

Ryu, Seungyeob, E-mail: syryu@kaeri.re.kr [Korea Atomic Energy Research Institute (KAERI), 1045 Daeduk-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Youngin; Yoon, Juhyeon [Korea Atomic Energy Research Institute (KAERI), 1045 Daeduk-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Ko, Sungho, E-mail: sunghoko@cnu.ac.kr [Department of Mechanical Design Engineering, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejeon 305-764 (Korea, Republic of)

2014-01-15

Highlights: • We directly simulate circular-cap bubbles in low viscous liquids. • The counter diffusion multiphase lattice Boltzmann method is proposed. • The present method is validated through benchmark tests and experimental results. • The high-Reynolds-number bubbles can be simulated without any turbulence models. • The present method is feasible for the direct simulation of bubbly flows. -- Abstract: The counter diffusion lattice Boltzmann method (LBM) is used to directly simulate rising circular-cap bubbles in low viscous liquids. A counter diffusion model for single phase flows has been extended to multiphase flows, and the implicit formulation is converted into an explicit one for easy calculation. Bubbles at high Reynolds numbers ranging from O(10{sup 2}) to O(10{sup 4}) are simulated successfully without any turbulence models, which cannot be done for the existing LBM versions. The characteristics of the circular-cap bubbles are studied for a wide range of Morton numbers and compared with the previous literature. Calculated results agree with the theoretical and experimental data. Consequently, the wake phenomena of circular-cap bubbles and bubble induced turbulence are presented.

A gradient activation method for direct methanol fuel cells

International Nuclear Information System (INIS)

Liu, Guicheng; Yang, Zhaoyi; Halim, Martin; Li, Xinyang; Wang, Manxiang; Kim, Ji Young; Mei, Qiwen; Wang, Xindong; Lee, Joong Kee

2017-01-01

Highlights: • A gradient activation method was reported firstly for direct methanol fuel cells. • The activity recovery of Pt-based catalyst was introduced into the novel activation process. • The new activation method led to prominent enhancement of DMFC performance. • DMFC performance was improved with the novel activation step by step within 7.5 h. - Abstract: To realize gradient activation effect and recover catalytic activity of catalyst in a short time, a gradient activation method has firstly been proposed for enhancing discharge performance and perfecting activation mechanism of the direct methanol fuel cell (DMFC). This method includes four steps, i.e. proton activation, activity recovery activation, H_2-O_2 mode activation and forced discharging activation. The results prove that the proposed method has gradually realized replenishment of water and protons, recovery of catalytic activity of catalyst, establishment of transfer channels for electrons, protons, and oxygen, and optimization of anode catalyst layer for methanol transfer in turn. Along with the novel activation process going on, the DMFC discharge performance has been improved, step by step, to more than 1.9 times higher than that of the original one within 7.5 h. This method provides a practicable activation way for the real application of single DMFCs and stacks.

A Sequential Quadratically Constrained Quadratic Programming Method of Feasible Directions

International Nuclear Information System (INIS)

Jian Jinbao; Hu Qingjie; Tang Chunming; Zheng Haiyan

2007-01-01

In this paper, a sequential quadratically constrained quadratic programming method of feasible directions is proposed for the optimization problems with nonlinear inequality constraints. At each iteration of the proposed algorithm, a feasible direction of descent is obtained by solving only one subproblem which consist of a convex quadratic objective function and simple quadratic inequality constraints without the second derivatives of the functions of the discussed problems, and such a subproblem can be formulated as a second-order cone programming which can be solved by interior point methods. To overcome the Maratos effect, an efficient higher-order correction direction is obtained by only one explicit computation formula. The algorithm is proved to be globally convergent and superlinearly convergent under some mild conditions without the strict complementarity. Finally, some preliminary numerical results are reported

Determination of velocity vector angles using the directional cross-correlation method

DEFF Research Database (Denmark)

Kortbek, Jacob; Jensen, Jørgen Arendt

2005-01-01

and then select the angle with the highest normalized correlation between directional signals. The approach is investigated using Field II simulations and data from the experimental ultrasound scanner RASMUS and with a parabolic flow having a peak velocity of 0.3 m/s. A 7 MHz linear array transducer is used......A method for determining both velocity magnitude and angle in any direction is suggested. The method uses focusing along the velocity direction and cross-correlation for finding the correct velocity magnitude. The angle is found from beamforming directional signals in a number of directions......-time ) between signals to correlate, and a proper choice varies with flow angle and flow velocity. One performance example is given with a fixed value of k tprf for all flow angles. The angle estimation on measured data for flow at 60 ◦ to 90 ◦ , yields a probability of valid estimates between 68% and 98...

Application of direct simulation Monte Carlo method for analysis of AVLIS evaporation process

International Nuclear Information System (INIS)

Nishimura, Akihiko

1995-01-01

The computation code of the direct simulation Monte Carlo (DSMC) method was developed in order to analyze the atomic vapor evaporation in atomic vapor laser isotope separation (AVLIS). The atomic excitation temperatures of gadolinium atom were calculated for the model with five low lying states. Calculation results were compared with the experiments obtained by laser absorption spectroscopy. Two types of DSMC simulations which were different in inelastic collision procedure were carried out. It was concluded that the energy transfer was forbidden unless the total energy of the colliding atoms exceeds a threshold value. (author)

Direct olive oil analysis by mass spectrometry: A comparison of different ambient ionization methods.

Science.gov (United States)

Lara-Ortega, Felipe J; Beneito-Cambra, Miriam; Robles-Molina, José; García-Reyes, Juan F; Gilbert-López, Bienvenida; Molina-Díaz, Antonio

2018-04-01

Analytical methods based on ambient ionization mass spectrometry (AIMS) combine the classic outstanding performance of mass spectrometry in terms of sensitivity and selectivity along with convenient features related to the lack of sample workup required. In this work, the performance of different mass spectrometry-based methods has been assessed for the direct analyses of virgin olive oil for quality purposes. Two sets of experiments have been setup: (1) direct analysis of untreated olive oil using AIMS methods such as Low-Temperature Plasma Mass Spectrometry (LTP-MS) or paper spray mass spectrometry (PS-MS); or alternatively (2) the use of atmospheric pressure ionization (API) mass spectrometry by direct infusion of a diluted sample through either atmospheric pressure chemical ionization (APCI) or electrospray (ESI) ionization sources. The second strategy involved a minimum sample work-up consisting of a simple olive oil dilution (from 1:10 to 1:1000) with appropriate solvents, which originated critical carry over effects in ESI, making unreliable its use in routine; thus, ESI required the use of a liquid-liquid extraction to shift the measurement towards a specific part of the composition of the edible oil (i.e. polyphenol rich fraction or lipid/fatty acid profile). On the other hand, LTP-MS enabled direct undiluted mass analysis of olive oil. The use of PS-MS provided additional advantages such as an extended ionization coverage/molecular weight range (compared to LTP-MS) and the possibility to increase the ionization efficiency towards nonpolar compounds such as squalene through the formation of Ag + adducts with carbon-carbon double bounds, an attractive feature to discriminate between oils with different degree of unsaturation. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative study on flow rate measurement by nuclear and conventional methods in selected rivers at Ulu Langat district, Selangor

Energy Technology Data Exchange (ETDEWEB)

Wan Mohamad Tahir, Wan Zakaria; Mohamad, Daud; Hamzah, Abdul Razak; Yusuf, Johari Mohamad; Aziz Wan Mohamad, Wan Abdul

1986-06-01

A radiotracer technique using Tc-99 to measure flows of small rivers was introduced in Malaysia. Three rivers in the Ulu Langat District were selected for a comparative study on flow rate determination by conventional and radioisotope methods. Radioisotopic approach, comprising injection procedures, calibration, mixing length and safety aspects are discussed. The results measured by radioisotope method are compared to the Drainage and Irrigation Department's (DID's) discharge curves data collected from 1980 to 1982 which is calibrated using a current meter. The results are comparable and fall within the range obtained by conventional method. Related to this study, a comprehensive work on stream gauging of moderate and high flow rates using both methods is proposed to be carried out directly.

An improved principal component analysis based region matching method for fringe direction estimation

Science.gov (United States)

He, A.; Quan, C.

2018-04-01

The principal component analysis (PCA) and region matching combined method is effective for fringe direction estimation. However, its mask construction algorithm for region matching fails in some circumstances, and the algorithm for conversion of orientation to direction in mask areas is computationally-heavy and non-optimized. We propose an improved PCA based region matching method for the fringe direction estimation, which includes an improved and robust mask construction scheme, and a fast and optimized orientation-direction conversion algorithm for the mask areas. Along with the estimated fringe direction map, filtered fringe pattern by automatic selective reconstruction modification and enhanced fast empirical mode decomposition (ASRm-EFEMD) is used for Hilbert spiral transform (HST) to demodulate the phase. Subsequently, windowed Fourier ridge (WFR) method is used for the refinement of the phase. The robustness and effectiveness of proposed method are demonstrated by both simulated and experimental fringe patterns.

Comparative Effects of Biomass Pre-Treatments for Direct and Indirect Transesterification to Enhance Microalgal Lipid Recovery

International Nuclear Information System (INIS)

Ghasemi Naghdi, Forough; Thomas-Hall, Skye R.; Durairatnam, Reuben; Pratt, Steven; Schenk, Peer M.

2014-01-01

Microalgal lipid recovery for biodiesel production is currently considered suboptimal, but pre-treatment of algal biomass, the use of solvent mixtures and the positioning of transesterification can lead to increased yields. Here, the effect of various reportedly successful pre-treatments and solvent mixtures were directly compared to each other and combined with direct and indirect transesterification methods using the oleaginous microalga Tetraselmis sp. M8. Microwave and thermal pre-treatments were applied and the total lipid and fatty acid methyl ester (FAME) recoveries were investigated. The application of pre-treatments increased FAME recovery through indirect transesterification when a Soxhlet system was used but they had no significant effect for direct transesterification. Gravimetric analyses of total lipids revealed that lipid recovery was highest when utilizing the chloroform-based Bligh and Dyer extraction method; however, FAME yield was the highest when applying a Soxhlet system utilizing a solvent mixture of hexane–ethanol (3:1). Total lipid recovery did not necessarily correlate with the recovery of FAMEs. The highest FAME recovery was achieved from thermal or microwave pre-treated biomass followed by indirect transesterification through Soxhlet extraction. FAME recovery could be more than doubled (increase of up to 171%) under these conditions. We conclude that a simple thermal pre-treatment (80°C for 10 min) in combination with solvent mixture extraction through indirect transesterification may present a cost-effective and scalable option for large-scale lipid extraction from microalgae.

Comparative effects of biomass pre-treatments for direct and indirect transesterification to enhance microalgal lipid recovery

Directory of Open Access Journals (Sweden)

Forough eGhasemi Naghdi

2014-12-01

Full Text Available Microalgal lipid recovery for biodiesel production is currently considered suboptimal, but pre-treatment of algal biomass, the use of solvent mixtures and the positioning of transesterification can lead to increased yields. Here, the effect of various reportedly successful pre-treatments and solvent mixtures were directly compared to each other and combined with direct and indirect transesterification methods using the oleaginous microalga Tetraselmis sp. M8. Microwave and thermal pre-treatments were applied and the total lipid and fatty acid methyl ester (FAME recoveries were investigated. The application of pre-treatments increased FAME recovery through indirect transesterification when a Soxhlet system was used but they had no significant effect for direct transesterification. Gravimetric analyses of total lipids revealed that lipid recovery was highest when utilizing the chloroform-based Bligh and Dyer extraction method; however FAME yield was the highest when applying a Soxhlet system utilizing a solvent mixture of hexane-ethanol (3:1. Total lipid recovery did not necessarily correlate with the recovery of FAMEs. The highest FAME recovery was achieved from thermal or microwave pre-treated biomass followed by indirect transesterification through Soxhlet extraction. FAME recovery could be more than doubled (increase of up to 171% under these conditions. We conclude that a simple thermal pre-treatment (80°C for 10 min in combination with solvent mixture extraction through indirect transesterification may present a cost-effective and scalable option for large-scale lipid extraction from microalgae.

Comparative Effects of Biomass Pre-Treatments for Direct and Indirect Transesterification to Enhance Microalgal Lipid Recovery

Energy Technology Data Exchange (ETDEWEB)

Ghasemi Naghdi, Forough; Thomas-Hall, Skye R.; Durairatnam, Reuben [Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD (Australia); Pratt, Steven [School of Chemical Engineering, The University of Queensland, Brisbane, QLD (Australia); Schenk, Peer M., E-mail: p.schenk@uq.edu.au [Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD (Australia)

2014-12-04

Microalgal lipid recovery for biodiesel production is currently considered suboptimal, but pre-treatment of algal biomass, the use of solvent mixtures and the positioning of transesterification can lead to increased yields. Here, the effect of various reportedly successful pre-treatments and solvent mixtures were directly compared to each other and combined with direct and indirect transesterification methods using the oleaginous microalga Tetraselmis sp. M8. Microwave and thermal pre-treatments were applied and the total lipid and fatty acid methyl ester (FAME) recoveries were investigated. The application of pre-treatments increased FAME recovery through indirect transesterification when a Soxhlet system was used but they had no significant effect for direct transesterification. Gravimetric analyses of total lipids revealed that lipid recovery was highest when utilizing the chloroform-based Bligh and Dyer extraction method; however, FAME yield was the highest when applying a Soxhlet system utilizing a solvent mixture of hexane–ethanol (3:1). Total lipid recovery did not necessarily correlate with the recovery of FAMEs. The highest FAME recovery was achieved from thermal or microwave pre-treated biomass followed by indirect transesterification through Soxhlet extraction. FAME recovery could be more than doubled (increase of up to 171%) under these conditions. We conclude that a simple thermal pre-treatment (80°C for 10 min) in combination with solvent mixture extraction through indirect transesterification may present a cost-effective and scalable option for large-scale lipid extraction from microalgae.

A direct sampling method to an inverse medium scattering problem

KAUST Repository

Ito, Kazufumi

2012-01-10

In this work we present a novel sampling method for time harmonic inverse medium scattering problems. It provides a simple tool to directly estimate the shape of the unknown scatterers (inhomogeneous media), and it is applicable even when the measured data are only available for one or two incident directions. A mathematical derivation is provided for its validation. Two- and three-dimensional numerical simulations are presented, which show that the method is accurate even with a few sets of scattered field data, computationally efficient, and very robust with respect to noises in the data. © 2012 IOP Publishing Ltd.

Comparative analysis of machine learning methods in ligand-based virtual screening of large compound libraries.

Science.gov (United States)

Ma, Xiao H; Jia, Jia; Zhu, Feng; Xue, Ying; Li, Ze R; Chen, Yu Z

2009-05-01

Machine learning methods have been explored as ligand-based virtual screening tools for facilitating drug lead discovery. These methods predict compounds of specific pharmacodynamic, pharmacokinetic or toxicological properties based on their structure-derived structural and physicochemical properties. Increasing attention has been directed at these methods because of their capability in predicting compounds of diverse structures and complex structure-activity relationships without requiring the knowledge of target 3D structure. This article reviews current progresses in using machine learning methods for virtual screening of pharmacodynamically active compounds from large compound libraries, and analyzes and compares the reported performances of machine learning tools with those of structure-based and other ligand-based (such as pharmacophore and clustering) virtual screening methods. The feasibility to improve the performance of machine learning methods in screening large libraries is discussed.

Biasing transition rate method based on direct MC simulation for probabilistic safety assessment

Institute of Scientific and Technical Information of China (English)

Xiao-Lei Pan; Jia-Qun Wang; Run Yuan; Fang Wang; Han-Qing Lin; Li-Qin Hu; Jin Wang

2017-01-01

Direct Monte Carlo (MC) simulation is a powerful probabilistic safety assessment method for accounting dynamics of the system.But it is not efficient at simulating rare events.A biasing transition rate method based on direct MC simulation is proposed to solve the problem in this paper.This method biases transition rates of the components by adding virtual components to them in series to increase the occurrence probability of the rare event,hence the decrease in the variance of MC estimator.Several cases are used to benchmark this method.The results show that the method is effective at modeling system failure and is more efficient at collecting evidence of rare events than the direct MC simulation.The performance is greatly improved by the biasing transition rate method.

Evaluation of two methods for direct detection of Fusarium spp. in water.

Science.gov (United States)

Graça, Mariana G; van der Heijden, Inneke M; Perdigão, Lauro; Taira, Cleison; Costa, Silvia F; Levin, Anna S

2016-04-01

Fusarium is a waterborne fungus that causes severe infections especially in patients with prolonged neutropenia. Traditionally, the detection of Fusarium in water is done by culturing which is difficult and time consuming. A faster method is necessary to prevent exposure of susceptible patients to contaminated water. The objective of this study was to develop a molecular technique for direct detection of Fusarium in water. A direct DNA extraction method from water was developed and coupled to a genus-specific PCR, to detect 3 species of Fusarium (verticillioides, oxysporum and solani). The detection limits were 10 cells/L and 1 cell/L for the molecular and culture methods, respectively. To our knowledge, this is the first method developed to detect Fusarium directly from water. Copyright © 2016 Elsevier B.V. All rights reserved.

Model-compared RGU-photometric space-densities in the direction to M 5 (l = 40, b = +470)

International Nuclear Information System (INIS)

Fenkart, R.; Karaali, S.

1990-01-01

In the process of rounding off the results homogeneously obtained within the model-comparison phase of the Basle Halo Program, space densities of both photometric populations, I and II, have been derived, for late-type giants and for main-sequence stars with +3 m m , in a field close to the globular cluster M 5, according to the RGU-photometric Basle method. Compared to the density gradients predicted by the standard set of five multi-component models, used since the beginning of this phase, they confirm the existence of a Galactic Thick Disk component, in this direction, too

Direct methods for limit states in structures and materials

CERN Document Server

Weichert, Dieter

2014-01-01

Knowing the safety factor for limit states such as plastic collapse, low cycle fatigue or ratcheting is always a major design consideration for civil and mechanical engineering structures that are subjected to loads. Direct methods of limit or shakedown analysis that proceed to directly find the limit states offer a better alternative than exact time-stepping calculations as, on one hand, an exact loading history is scarcely known, and on the other they are much less time-consuming. This book presents the state of the art on various topics concerning these methods, such as theoretical advances in limit and shakedown analysis, the development of relevant algorithms and computational procedures, sophisticated modeling of inelastic material behavior like hardening, non-associated flow rules, material damage and fatigue, contact and friction, homogenization and composites.

Comparative Study of Two Daylighting Analysis Methods with Regard to Window Orientation and Interior Wall Reflectance

Directory of Open Access Journals (Sweden)

Yeo Beom Yoon

2014-09-01

Full Text Available The accuracy and speed of the daylighting analysis developed for use in EnergyPlus is better than its predecessors. In EnergyPlus, the detailed method uses the Split-flux algorithm whereas the DElight method uses the Radiosity algorithm. Many existing studies have addressed the two methods, either individually or compared with other daylight analysis methods like Ray tracing but still there is lack of detailed comparative study of these two methods. Our previous studies show that the Split-flux method overestimates the illuminance, especially for the areas away from the window. The Radiosity method has the advantage of accurately predicting this illuminance because of how it deals with the diffuse light. For this study, the EnergyPlus model, which has been calibrated using data measured in a real building in previous studies, has also been used. The calibrated model has a south oriented window only. This model is then used to analyze the interior illuminance inside the room for north, west and east orientation of the window by rotating the model and by changing the wall reflectance of the model with south oriented window. Direct and diffuse component of the illuminance as well as the algorithms have been compared for a detailed analysis.

A direct simulation method for flows with suspended paramagnetic particles

NARCIS (Netherlands)

Kang, T.G.; Hulsen, M.A.; Toonder, den J.M.J.; Anderson, P.D.; Meijer, H.E.H.

2008-01-01

A direct numerical simulation method based on the Maxwell stress tensor and a fictitious domain method has been developed to solve flows with suspended paramagnetic particles. The numerical scheme enables us to take into account both hydrodynamic and magnetic interactions between particles in a

Comparison of direct and precipitation methods for the estimation of ...

African Journals Online (AJOL)

Background: There is increase in use of direct assays for analysis of high and low density lipoprotein cholesterol by clinical laboratories despite differences in performance characteristics with conventional precipitation methods. Calculation of low density lipoprotein cholesterol in precipitation methods is based on total ...

Comparative Analysis of Fuzzy Set Defuzzification Methods in the Context of Ecological Risk Assessment

Directory of Open Access Journals (Sweden)

Užga-Rebrovs Oļegs

2017-12-01

Full Text Available Fuzzy inference systems are widely used in various areas of human activity. Their most widespread use lies in the field of fuzzy control of technical devices of different kind. Another direction of using fuzzy inference systems is modelling and assessment of different kind of risks under insufficient or missing objective initial data. Fuzzy inference is concluded by the procedure of defuzzification of the resulting fuzzy sets. A large number of techniques for implementing the defuzzification procedure are available nowadays. The paper presents a comparative analysis of some widespread methods of fuzzy set defuzzification, and proposes the most appropriate methods in the context of ecological risk assessment.

THE COST OF PRODUCTION UNDER DIRECT COSTING AND ABSORPTION COSTING – A COMPARATIVE APPROACH

Directory of Open Access Journals (Sweden)

Bunea-Bontaş Cristina Aurora

2013-04-01

Full Text Available Managerial accounting has an important role in strategic management of a company, being designed especially for managers, in order to optimise their decision regarding operating activities. One of the objectives of managerial accounting is the cost calculation, for measuring inventory costs, and the costs and profitability of products and services. Cost calculation systems can vary in terms of which costs are assigned to cost objects, two significant calculation systems being adopted by the costing theory: full cost accounting, which includes all costs of production as product costs, and partial cost accounting, which includes only those costs that vary with output. This article provides a comparative approach regarding the differences between the calculation of the cost of production under direct costing and absorption costing. It also examines the implication of using each of these calculation systems on the financial position and financial performance of the companies reported on the statement of financial position and the income statement. Finally, the advantages of using direct costing for internal reporting are discussed, considering that this method is not acceptable for external reporting to stockholders and other external users.

A direct sampling method for inverse electromagnetic medium scattering

KAUST Repository

Ito, Kazufumi; Jin, Bangti; Zou, Jun

2013-01-01

In this paper, we study the inverse electromagnetic medium scattering problem of estimating the support and shape of medium scatterers from scattered electric/magnetic near-field data. We shall develop a novel direct sampling method based

Effective atomic numbers of some tissue substitutes by different methods: A comparative study

Directory of Open Access Journals (Sweden)

Vishwanath P Singh

2014-01-01

Full Text Available Effective atomic numbers of some human organ tissue substitutes such as polyethylene terephthalate, red articulation wax, paraffin 1, paraffin 2, bolus, pitch, polyphenylene sulfide, polysulfone, polyvinylchloride, and modeling clay have been calculated by four different methods like Auto-Z eff, direct, interpolation, and power law. It was found that the effective atomic numbers computed by Auto-Z eff , direct and interpolation methods were in good agreement for intermediate energy region (0.1 MeV < E < 5 MeV where the Compton interaction dominates. A large difference in effective atomic numbers by direct method and Auto-Z eff was observed in photo-electric and pair-production regions. Effective atomic numbers computed by power law were found to be close to direct method in photo-electric absorption region. The Auto-Z eff , direct and interpolation methods were found to be in good agreement for computation of effective atomic numbers in intermediate energy region (100 keV < E < 10 MeV. The direct method was found to be appropriate method for computation of effective atomic numbers in photo-electric region (10 keV < E < 100 keV. The tissue equivalence of the tissue substitutes is possible to represent by any method for computation of effective atomic number mentioned in the present study. An accurate estimation of Rayleigh scattering is required to eliminate effect of molecular, chemical, or crystalline environment of the atom for estimation of gamma interaction parameters.

Calibration method for direct conversion receiver front-ends

Directory of Open Access Journals (Sweden)

R. Müller

2008-05-01

Full Text Available Technology induced process tolerances in analog circuits cause device characteristics different from specification. For direct conversion receiver front-ends a system level calibration method is presented. The malfunctions of the devices are compensated by tuning dominant circuit parameters. Thereto optimization techniques are applied which use measurement values and special evaluation functions.

Synthesise of Zn O nano wires by direct oxidation method

International Nuclear Information System (INIS)

Farbod, M.; Ahangarpour, A.

2007-01-01

Zn O is a semiconductor which has a direct and wide energy band which is about 3.37 eV at room temperature. It has various applications from UV lasers, sensitive sensors, solar cells to photo catalysis applications. Zn O has different nano structures such as nanoparticles, nano wires, nano rods, nano tubes and nano belts. The one dimensional Zn O nano structures such as nano wires are very important because of their applications in nano electronics and nano photonics so different methods have been proposed to synthesize them. In this work large scale of Zn O nano wires are produced by direct oxidation a Zn substrate (which was cleaned by chemical methods) in air or oxygen atmosphere at 400 d eg C . Nano wires were investigated by scanning electron microscopy and energy dispersive x-ray measurements. Their diameter is about 30-150 nanometer and their length is about several micrometer. This method which acts without any catalyst is a convenient method to synthesis semiconductor nano wires.

Comparative Study of Daylighting Calculation Methods

Directory of Open Access Journals (Sweden)

Mandala Ariani

2018-01-01

Full Text Available The aim of this study is to assess five daylighting calculation method commonly used in architectural study. The methods used include hand calculation methods (SNI/DPMB method and BRE Daylighting Protractors, scale models studied in an artificial sky simulator and computer programs using Dialux and Velux lighting software. The test room is conditioned by the uniform sky conditions, simple room geometry with variations of the room reflectance (black, grey, and white color. The analyses compared the result (including daylight factor, illumination, and coefficient of uniformity value and examines the similarity and contrast the result different. The color variations trial is used to analyses the internally reflection factor contribution to the result.

29 CFR 4211.35 - Direct attribution method for withdrawals after the initial plan year.

Science.gov (United States)

2010-07-01

... WITHDRAWING EMPLOYERS Allocation Methods for Merged Multiemployer Plans § 4211.35 Direct attribution method for withdrawals after the initial plan year. The allocation method under this section is the... 29 Labor 9 2010-07-01 2010-07-01 false Direct attribution method for withdrawals after the initial...

On method of solving third-order ordinary differential equations directly using Bernstein polynomials

Science.gov (United States)

Khataybeh, S. N.; Hashim, I.

2018-04-01

In this paper, we propose for the first time a method based on Bernstein polynomials for solving directly a class of third-order ordinary differential equations (ODEs). This method gives a numerical solution by converting the equation into a system of algebraic equations which is solved directly. Some numerical examples are given to show the applicability of the method.

Evaluation and Comparison of Accuracy of Measuring the Position of Miniscrew Implants using Two-dimensional Orthopantomogram and a Three-dimensional Imaging with Direct Method on Dried Skull

Directory of Open Access Journals (Sweden)

R H Kamble

2011-01-01

Conclusion: Ortopantomogram shows more variations on linear and angular measurements as compared to direct method and 3D radiography whereas direct method and 3D radiography show no difference. But, we can calculate the angulations of miniscrew implant placement by angular regression model.

A comparative experimental evaluation of uncertainty estimation methods for two-component PIV

Science.gov (United States)

Boomsma, Aaron; Bhattacharya, Sayantan; Troolin, Dan; Pothos, Stamatios; Vlachos, Pavlos

2016-09-01

Uncertainty quantification in planar particle image velocimetry (PIV) measurement is critical for proper assessment of the quality and significance of reported results. New uncertainty estimation methods have been recently introduced generating interest about their applicability and utility. The present study compares and contrasts current methods, across two separate experiments and three software packages in order to provide a diversified assessment of the methods. We evaluated the performance of four uncertainty estimation methods, primary peak ratio (PPR), mutual information (MI), image matching (IM) and correlation statistics (CS). The PPR method was implemented and tested in two processing codes, using in-house open source PIV processing software (PRANA, Purdue University) and Insight4G (TSI, Inc.). The MI method was evaluated in PRANA, as was the IM method. The CS method was evaluated using DaVis (LaVision, GmbH). Utilizing two PIV systems for high and low-resolution measurements and a laser doppler velocimetry (LDV) system, data were acquired in a total of three cases: a jet flow and a cylinder in cross flow at two Reynolds numbers. LDV measurements were used to establish a point validation against which the high-resolution PIV measurements were validated. Subsequently, the high-resolution PIV measurements were used as a reference against which the low-resolution PIV data were assessed for error and uncertainty. We compared error and uncertainty distributions, spatially varying RMS error and RMS uncertainty, and standard uncertainty coverages. We observed that qualitatively, each method responded to spatially varying error (i.e. higher error regions resulted in higher uncertainty predictions in that region). However, the PPR and MI methods demonstrated reduced uncertainty dynamic range response. In contrast, the IM and CS methods showed better response, but under-predicted the uncertainty ranges. The standard coverages (68% confidence interval) ranged from

A comparative experimental evaluation of uncertainty estimation methods for two-component PIV

International Nuclear Information System (INIS)

Boomsma, Aaron; Troolin, Dan; Pothos, Stamatios; Bhattacharya, Sayantan; Vlachos, Pavlos

2016-01-01

Uncertainty quantification in planar particle image velocimetry (PIV) measurement is critical for proper assessment of the quality and significance of reported results. New uncertainty estimation methods have been recently introduced generating interest about their applicability and utility. The present study compares and contrasts current methods, across two separate experiments and three software packages in order to provide a diversified assessment of the methods. We evaluated the performance of four uncertainty estimation methods, primary peak ratio (PPR), mutual information (MI), image matching (IM) and correlation statistics (CS). The PPR method was implemented and tested in two processing codes, using in-house open source PIV processing software (PRANA, Purdue University) and Insight4G (TSI, Inc.). The MI method was evaluated in PRANA, as was the IM method. The CS method was evaluated using DaVis (LaVision, GmbH). Utilizing two PIV systems for high and low-resolution measurements and a laser doppler velocimetry (LDV) system, data were acquired in a total of three cases: a jet flow and a cylinder in cross flow at two Reynolds numbers. LDV measurements were used to establish a point validation against which the high-resolution PIV measurements were validated. Subsequently, the high-resolution PIV measurements were used as a reference against which the low-resolution PIV data were assessed for error and uncertainty. We compared error and uncertainty distributions, spatially varying RMS error and RMS uncertainty, and standard uncertainty coverages. We observed that qualitatively, each method responded to spatially varying error (i.e. higher error regions resulted in higher uncertainty predictions in that region). However, the PPR and MI methods demonstrated reduced uncertainty dynamic range response. In contrast, the IM and CS methods showed better response, but under-predicted the uncertainty ranges. The standard coverages (68% confidence interval) ranged from

A method for removing sulfur bearing compounds from paraffinous hydrocarbons or a directly distilled benzine fraction

Energy Technology Data Exchange (ETDEWEB)

Konyukhova, T.P.; Bolotskaya, I.A.; Mikhaylova, L.A.; Sadykov, A.N.; Shitovkin, N.T.; Vlasov, V.V.

1983-01-01

In the known method for removing sulfurorganic compounds from paraffinous hydrocarbons or a directly distilled gasoline fraction through their adsorption using natural zeolite, in order to increase the degree of purification, clinoptilolite (Kp), which contains SiO2 and A12O3 in a molar ratio of 10.6 to 16.7 is used as the natural zeolite. The purification of the paraffinous hydrocarbons through clinoptilolite adsorption as compared with mordenite adsorption makes it possible to increase the degree of their purification of ethylmercaptane and dimethylsulfide. The effectiveness of clinoptilolite is also confirmed in removing mercaptanes and sulfides from directly distilled gasoline fractions.

The improved quasi-static method vs the direct method: a case study for CANDU reactor transients

International Nuclear Information System (INIS)

Kaveh, S.; Koclas, J.; Roy, R.

1999-01-01

Among the large number of methods for the transient analysis of nuclear reactors, the improved quasi-static procedure is one of the most widely used. In recent years, substantial increase in both computer speed and memory has motivated a rethinking of the limitations of this method. The overall goal of the present work is a systematic comparison between the improved quasi-static and the direct method (mesh-centered finite difference) for realistic CANDU transient simulations. The emphasis is on the accuracy of the solutions as opposed to the computational speed. Using the computer code NDF, a typical realistic transient of CANDU reactor has been analyzed. In this transient the response of the reactor regulating system to a substantial local perturbation (sudden extraction of the five adjuster rods) has been simulated. It is shown that when updating the detector responses is of major importance, it is better to use a well-optimized direct method rather than the improved quasi-static method. (author)

Fabrication And Determination Of Coefficient Absorption Of Hydrogenated Amorphous Silicon By Direct Evaporation Method

International Nuclear Information System (INIS)

Santoso, Agus; Darsono; Sujitno, Tjipto; Suprapto

1996-01-01

Fabrication and characterization of hydrogenated amorphous silicon produced by direct evaporation method have been done. The experiment was carried out at pressure conditions of 2 x 10-5 torr, RF frequency of 13.56 MHz, hydrogen gas flow of 0,8 1/minute, electrode distance of 2.48 cm. voltage electrode of 700 volt and evaporation time 1.45 minute. Using UV-VIS spectrophotometer, it is found that at wavelength of 359 nm, the absorbance degree of material that was by direct hydrogenated method was 0,886. This means that more hydrogen are absorbed by direct method While, if the hydrogenation is carried out by means of indirect method, the degree of absorbance at the wavelength of 359 nm is 0,103. From this result, it can be concluded that the direct methods is better than indirect method

CoVennTree: A new method for the comparative analysis of large datasets

Directory of Open Access Journals (Sweden)

Steffen C. Lott

2015-02-01

Full Text Available The visualization of massive datasets, such as those resulting from comparative metatranscriptome analyses or the analysis of microbial population structures using ribosomal RNA sequences, is a challenging task. We developed a new method called CoVennTree (Comparative weighted Venn Tree that simultaneously compares up to three multifarious datasets by aggregating and propagating information from the bottom to the top level and produces a graphical output in Cytoscape. With the introduction of weighted Venn structures, the contents and relationships of various datasets can be correlated and simultaneously aggregated without losing information. We demonstrate the suitability of this approach using a dataset of 16S rDNA sequences obtained from microbial populations at three different depths of the Gulf of Aqaba in the Red Sea. CoVennTree has been integrated into the Galaxy ToolShed and can be directly downloaded and integrated into the user instance.

Right to privacy and some methods of direct marketing

Directory of Open Access Journals (Sweden)

Hana Kelblová

2013-01-01

Full Text Available Promotion constitutes part of the marketing mix which consists of advertising, sales support, public relations, personal sale and direct marketing. It may be stated that the law delimits boundaries to all these elements of the communication mix. In the following contribution I will only focus on some methods of direct marketing and I intend to investigate the “purposeful appeal to purchase and consumer behaviour of clients” as viewed by the present Czech law. These communications often disturb the privacy of individuals, harass in an inappropriate time, marketing companies often illegally collect and share customers’ personal information. My target is to list legal limits instituted in the sphere of direct marketing for the individual marketing practices by the Czech law.

A new rapid method for direct antimicrobial susceptibility testing of bacteria from positive blood cultures.

Science.gov (United States)

Barnini, Simona; Brucculeri, Veronica; Morici, Paola; Ghelardi, Emilia; Florio, Walter; Lupetti, Antonella

2016-08-12

Rapid identification and antimicrobial susceptibility testing (AST) of the causative agent(s) of bloodstream infections can lead to prompt appropriate antimicrobial therapy. To shorten species identification, in this study bacteria were recovered from monomicrobial blood cultures by serum separator tubes and spotted onto the target plate for direct MALDI-TOF MS identification. Proper antibiotics were selected for direct AST based on species identification. In order to obtain rapid AST results, bacteria were recovered from positive blood cultures by two different protocols: by serum separator tubes (further referred to as PR1), or after a short-term subculture in liquid medium (further referred to as PR2). The results were compared with those obtained by the method currently used in our laboratory consisting in identification by MALDI-TOF and AST by Vitek 2 or Sensititre on isolated colonies. The direct MALDI-TOF method concordantly identified with the current method 97.5 % of the Gram-negative bacteria and 96.1 % of the Gram-positive cocci contained in monomicrobial blood cultures. The direct AST by PR1 and PR2 for all isolate/antimicrobial agent combinations was concordant/correct with the current method for 87.8 and 90.5 % of Gram-negative bacteria and for 93.1 and 93.8 % of Gram-positive cocci, respectively. In particular, 100 % categorical agreement was found with levofloxacin for Enterobacteriaceae by both PR1 and PR2, and 99.0 and 100 % categorical agreement was observed with linezolid for Gram-positive cocci by PR1 and PR2, respectively. There was no significant difference in accuracy between PR1 and PR2 for Gram-negative bacteria and Gram-positive cocci. This newly described method seems promising for providing accurate AST results. Most importantly, these results would be available in a few hours from blood culture positivity, which would help clinicians to promptly confirm or streamline an effective antibiotic therapy in patients with bloodstream

A Fifth Order Hybrid Linear Multistep method For the Direct Solution ...

African Journals Online (AJOL)

A linear multistep hybrid method (LMHM)with continuous coefficients isconsidered and directly applied to solve third order initial and boundary value problems (IBVPs). The continuous method is used to obtain Multiple Finite Difference Methods (MFDMs) (each of order 5) which are combined as simultaneous numerical ...

Comparing intracerebral hemorrhages associated with direct oral anticoagulants or warfarin

Science.gov (United States)

Kurogi, Ryota; Nishimura, Kunihiro; Nakai, Michikazu; Kada, Akiko; Kamitani, Satoru; Nakagawara, Jyoji; Toyoda, Kazunori; Ogasawara, Kuniaki; Ono, Junichi; Shiokawa, Yoshiaki; Aruga, Toru; Miyachi, Shigeru; Nagata, Izumi; Matsuda, Shinya; Yoshimura, Shinichi; Okuchi, Kazuo; Suzuki, Akifumi; Nakamura, Fumiaki; Onozuka, Daisuke; Ido, Keisuke; Kurogi, Ai; Mukae, Nobutaka; Nishimura, Ataru; Arimura, Koichi; Kitazono, Takanari; Hagihara, Akihito

2018-01-01

Objectives This cross-sectional survey explored the characteristics and outcomes of direct oral anticoagulant (DOAC)–associated nontraumatic intracerebral hemorrhages (ICHs) by analyzing a large nationwide Japanese discharge database. Methods We analyzed data from 2,245 patients who experienced ICHs while taking anticoagulants (DOAC: 227; warfarin: 2,018) and were urgently hospitalized at 621 institutions in Japan between April 2010 and March 2015. We compared the DOAC- and warfarin-treated patients based on their backgrounds, ICH severities, antiplatelet therapies at admission, hematoma removal surgeries, reversal agents, mortality rates, and modified Rankin Scale scores at discharge. Results DOAC-associated ICHs were less likely to cause moderately or severely impaired consciousness (DOAC-associated ICHs: 31.3%; warfarin-associated ICHs: 39.4%; p = 0.002) or require surgical removal (DOAC-associated ICHs: 5.3%; warfarin-associated ICHs: 9.9%; p = 0.024) in the univariate analysis. Propensity score analysis revealed that patients with DOAC-associated ICHs also exhibited lower mortality rates within 1 day (odds ratio [OR] 4.96, p = 0.005), within 7 days (OR 2.29, p = 0.037), and during hospitalization (OR 1.96, p = 0.039). Conclusions This nationwide study revealed that DOAC-treated patients had less severe ICHs and lower mortality rates than did warfarin-treated patients, probably due to milder hemorrhages at admission and lower hematoma expansion frequencies. PMID:29490916

A validation of direct grey Dancoff factors results for cylindrical cells in cluster geometry by the Monte Carlo method

International Nuclear Information System (INIS)

Rodrigues, Leticia Jenisch; Bogado, Sergio; Vilhena, Marco T.

2008-01-01

The WIMS code is a well known and one of the most used codes to handle nuclear core physics calculations. Recently, the PIJM module of the WIMS code was modified in order to allow the calculation of Grey Dancoff factors, for partially absorbing materials, using the alternative definition in terms of escape and collision probabilities. Grey Dancoff factors for the Canadian CANDU-37 and CANFLEX assemblies were calculated with PIJM at five symmetrically distinct fuel pin positions. The results, obtained via Direct Method, i.e., by direct calculation of escape and collision probabilities, were satisfactory when compared with the ones of literature. On the other hand, the PIJMC module was developed to calculate escape and collision probabilities using Monte Carlo method. Modifications in this module were performed to determine Black Dancoff factors, considering perfectly absorbing fuel rods. In this work, we proceed further in the task of validating the Direct Method by the Monte Carlo approach. To this end, the PIJMC routine is modified to compute Grey Dancoff factors using the cited alternative definition. Results are reported for the mentioned CANDU-37 and CANFLEX assemblies obtained with PIJMC, at the same fuel pin positions as with PIJM. A good agreement is observed between the results from the Monte Carlo and Direct methods

Joining direct and indirect inverse calibration methods to characterize karst, coastal aquifers

Science.gov (United States)

De Filippis, Giovanna; Foglia, Laura; Giudici, Mauro; Mehl, Steffen; Margiotta, Stefano; Negri, Sergio

2016-04-01

Parameter estimation is extremely relevant for accurate simulation of groundwater flow. Parameter values for models of large-scale catchments are usually derived from a limited set of field observations, which can rarely be obtained in a straightforward way from field tests or laboratory measurements on samples, due to a number of factors, including measurement errors and inadequate sampling density. Indeed, a wide gap exists between the local scale, at which most of the observations are taken, and the regional or basin scale, at which the planning and management decisions are usually made. For this reason, the use of geologic information and field data is generally made by zoning the parameter fields. However, pure zoning does not perform well in the case of fairly complex aquifers and this is particularly true for karst aquifers. In fact, the support of the hydraulic conductivity measured in the field is normally much smaller than the cell size of the numerical model, so it should be upscaled to a scale consistent with that of the numerical model discretization. Automatic inverse calibration is a valuable procedure to identify model parameter values by conditioning on observed, available data, limiting the subjective evaluations introduced with the trial-and-error technique. Many approaches have been proposed to solve the inverse problem. Generally speaking, inverse methods fall into two groups: direct and indirect methods. Direct methods allow determination of hydraulic conductivities from the groundwater flow equations which relate the conductivity and head fields. Indirect methods, instead, can handle any type of parameters, independently from the mathematical equations that govern the process, and condition parameter values and model construction on measurements of model output quantities, compared with the available observation data, through the minimization of an objective function. Both approaches have pros and cons, depending also on model complexity. For

COMPARING OPTICALAND DIRECT METHODS FOR LEAFAREA INDEX DETERMINATION IN A MAIZE CROP

Directory of Open Access Journals (Sweden)

Arianna Facchi

2010-03-01

Full Text Available Leaf area index (LAI is a crucial variable in the modelling of many hydrological processes. Destructive sampling of LAI is extremely time-consuming, thus not suitable for monitoring temporal/spatial variations of the variable. In the last fifty years optical instruments retrieving LAI from more easily measurable variables (i.e. transmitted radiation through canopies have been developed. Several instruments are available on the market, but very few are the studies comparing LAI estimates in agricultural crops. In this paper three optical instruments are compared with destructive sampling for a maize crop located in Northern Italy. Determinations were carried out on three plots (replicates before and after successive thinning of plant populations. Destructively sampled LAI ranged from 4.9 m2m-2 (no thinning to 1.2 m2m- 2 (maximum thinning. Correlation analysis showed that estimates by the AccuPAR-80, the hemispherical camera (“effective” and “true” LAI and the LAI- 2000 (in the standard configuration, i.e. five zenithal rings, and excluding the fifth ring were well correlated with destructive measurements (R2≥0.95. Anyway, if for the AccuPAR-80 the regression line was close to the 1:1 line, the “true LAI” by hemispherical photography tended to overestimate destructively sampled LAI for low values while the “effective LAI” and the LAI-2000 to underestimate it for high values (in a minor way for the LAI-2000 when the fifth ring was removed. Results from the ANOVA and the Tukey T test for two-factor experiments with replicates showed that only the “effective LAI” retrieved by hemispherical photographs and the estimates provided by the LAI-2000 in the standard configuration (five rings were statistically different from destructive measurements.

Effects of AFM tip-based direct and vibration assisted scratching methods on nanogrooves fabrication on a polymer resist

Energy Technology Data Exchange (ETDEWEB)

Geng, Yanquan [The State Key Laboratory of Robotics and Systems, Robotics Institute, Harbin Institute of Technology, Harbin, Heilongjiang 150080 (China); Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001 (China); Yan, Yongda, E-mail: yanyongda@hit.edu.cn [The State Key Laboratory of Robotics and Systems, Robotics Institute, Harbin Institute of Technology, Harbin, Heilongjiang 150080 (China); Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001 (China); Zhuang, Yun; Hu, Zhenjiang [Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001 (China)

2015-11-30

Graphical abstract: - Highlights: • The comparison of three different atomic force microscope (AFM) tip-based material processing techniques to generate nano-grooves on polymethylmethacrylate (PMMA) thin film is presented. • The machined depths of the nano-grooves machined by these three methods are analyzed. • Nano-groove with the machined depth closed to the thickness of the thin-film resist is achieved. - Abstract: This study proposes two atomic force microscope (AFM) tip-based direct nanoscratching methods including single-pass scratching and multi-pass scratching compared with a vibration-assisted scratching method to fabricate nano-grooves on the surface of the polymethylmethacrylate (PMMA) thin-film resist. In order to protect the AFM tip from wearing and optimize the subsequent etching process, the machined depth is expected slightly less than the PMMA thickness to prevent the tip directly contacting with the silicon substrate and obtain better process results. First, single-pass scratching tests are performed on films with different thickness employing varied normal loads. Results show that the machined depths of the grooves cannot be obtained slightly less than the thickness of the film very easily when scratching with single-pass method, 50–120 nm in the present study, which may not be very suitable for the following etching process. Multi-pass and vibration-assisted methods are then utilized to solve this limitation of the machined depth in single-pass process. The machined depths using the multi-pass method are dependent on scratching times and the applied normal loads. Moreover, the depth closed to the thickness of the film can be obtained by enlarging the number of the scratching cycles. However, with a longer scratching time, large tip wear can be found. For vibration assisted method, the machined depths are controlled by the vibration amplitude and the applied normal load. With the vibration in z direction increasing, the machined depth can

Lower radiation burden in state of the art fluoroscopic cystography compared to direct isotope cystography in children.

Science.gov (United States)

Haid, Bernhard; Becker, Tanja; Koen, Mark; Berger, Christoph; Langsteger, Werner; Gruy, Bernhard; Putz, Ernst; Haid, Stephanie; Oswald, Josef

2015-02-01

Both, fluoroscopic voiding cystourethrography (fVCUG) and direct isotope cystography (DIC) are diagnostic tools commonly used in pediatric urology. Both methods can detect vesicoureteral reflux (VUR) with a high sensitivity. Whilst the possibility to depict anatomical details and important structures as for instance the urethra in boys or the detailed calyceal anatomy are advantages of fVCUG, a lower radiation burden is thought to be the main advantage of DIC. In the last decade, however, a rapid technical evolution has occurred in fluoroscopy by implementing digital grid-controlled, variable rate, pulsed acquisition technique. As documented in literature this led to a substantial decrease in radiation burden conferred during fVCUGs. To question the common belief that direct isotope cystography confers less radiation burden compared to state of the art fluoroscopic voiding cystography. Radiation burden of direct isotope cystography in 92 children and in additional 7 children after an adaption of protocol was compared to radiation burden of fluoroscopic voiding cystourethrography in 51. The examinations were performed according to institutional protocols. For calculation of mean effective radiation dose [mSv] for either method published physical models correcting for age and sex were used. For DIC the model published by Stabin et al., 1998 was applied, for fVCUG two different physical models were used (Schultz et al., 1999, Lee et al., 2009). The radiation burden conferred by direct isotope cystography was significantly higher as for fluoroscopic voiding cystourethrography. The mean effective radiation dose for direct isotope cystography accounted to 0.23 mSv (± 0.34 m, median 0.085 mSv) compared to 0.015 mSv (± 0.013, median 0.008 mSv, model by Schultz et al.) - 0.024 mSv (± 0.018, median 0.018 mSv, model by Lee et al.) for fluoroscopic voiding cystourethrography. After a protocol adaption to correct for a longer examination time in DIC that was caused by

A Root-MUSIC-Like Direction Finding Method for Cyclostationary Signals

Directory of Open Access Journals (Sweden)

Yide Wang

2005-01-01

Full Text Available We propose a new root-MUSIC-like direction finding algorithm that exploits cyclostationarity in order to improve the direction-of-arrival estimation. The proposed cyclic method is signal selective, it allows to increase the resolution power and the noise robustness significantly, and it is also able to handle more sources than the number of sensors. Computer simulations are used to show the performance of the algorithm.

A study on direct alloying with molybdenum oxides by feed wire method

Directory of Open Access Journals (Sweden)

Jingjing Zou

2018-04-01

Full Text Available Direct alloying with molybdenum oxides has been regarded in years; the main addition methods are adding to the bottom of electric arc furnace (EAF with scrap, adding to the ladle during the converter tapping and mixing molybdenum oxide, lime and reductant to prepare pellet added to basic oxygen furnace (BOF. In this paper, a new method for direct alloying with molybdenum trioxide is proposed, adding molybdenum trioxide molten steel by feeding wire method in ladle furnace (LF refining process. The feasibility of molybdenum oxide reduction, the influence rules of bottom-blown on liquid steel fluidity and the yield of molybdenum by feeding wire method were analyzed. Results show that molybdenum oxide can be reduced by [Al], [Si], [C], and even [Fe] in molten steel. Bottom blowing position has a significant influence on the flow of molten steel when the permeable brick is located in 1/2 radius. The yields of Mo are higher than 97% for the experiments with feed wire method, the implementation of direct alloying with molybdenum trioxide by feed wire method works even better than that uses of ferromolybdenum in the traditional process.

29 CFR 4206.7 - Amount of credit in plans using the direct attribution method.

Science.gov (United States)

2010-07-01

... TO A PARTIAL WITHDRAWAL § 4206.7 Amount of credit in plans using the direct attribution method. In a plan that uses the direct attribution allocation method described in section 4211(c)(4) of ERISA, the... 29 Labor 9 2010-07-01 2010-07-01 false Amount of credit in plans using the direct attribution...

Comparative Study of Different Processing Methods for the ...

African Journals Online (AJOL)

The result of the two processing methods reduced the cyanide concentration to the barest minimum level required by World Health Organization (10mg/kg). The mechanical pressing-fermentation method removed more cyanide when compared to fermentation processing method. Keywords: Cyanide, Fermentation, Manihot ...

Comparing early design methods for children

NARCIS (Netherlands)

Sluis - Thiescheffer, R.J.W.; Bekker, M.M.; Eggen, J.H.; Robertson, J.; Skov, M.B.; Bekker, M.M.

2007-01-01

This paper describes a study which compares the outcome of two early design methods for children: brainstorming and prototyping. The hypothesis is that children will uncover more design ideas when prototyping than when brainstorming, because prototyping requires the use of a wider range of

Comparative assessment of cyclic J-R curve determination by different methods in a pressure vessel steel

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Tamshuk, E-mail: tamshuk@gmail.com [Deep Sea Technologies, National Institute of Ocean Technology, Chennai, 600100 (India); Sivaprasad, S.; Bar, H.N.; Tarafder, S. [Fatigue & Fracture Group, Materials Science and Technology Division, CSIR-National Metallurgical Laboratory, Jamshedpur, 831007 (India); Bandyopadhyay, N.R. [School of Materials Science and Engineering, Indian Institute of Engineering, Science and Technology, Shibpur, Howrah, 711103 (India)

2016-04-15

Cyclic J-R behaviour of a reactor pressure vessel steel using different methods available in literature has been examined to identify the best suitable method for cyclic fracture problems. Crack opening point was determined by moving average method. The η factor was experimentally determined for cyclic loading conditions and found to be similar to that of ASTM value. Analyses showed that adopting a procedure analogous to the ASTM standard for monotonic fracture is reasonable for cyclic fracture problems, and makes the comparison to monotonic fracture results straightforward. - Highlights: • Different methods of cyclic J-R evaluation compared. • A moving average method for closure point proposed. • η factor for cyclic J experimentally validated. • Method 1 is easier, provides a lower bound and direct comparison to monotonic fracture.

An efficient implicit direct forcing immersed boundary method for incompressible flows

International Nuclear Information System (INIS)

Cai, S-G; Ouahsine, A; Smaoui, H; Favier, J; Hoarau, Y

2015-01-01

A novel efficient implicit direct forcing immersed boundary method for incompressible flows with complex boundaries is presented. In the previous work [1], the calculation is performed on the Cartesian grid regardless of the immersed object, with a fictitious force evaluated on the Lagrangian points to mimic the presence of the physical boundaries. However the explicit direct forcing method [1] fails to accurately impose the non-slip boundary condition on the immersed interface. In the present work, the calculation is based on the implicit treatment of the artificial force while in an effective way of system iteration. The accuracy is also improved by solving the Navier-Stokes equation with the rotational incremental pressure- correction projection method of Guermond and Shen [2]. Numerical simulations performed with the proposed method are in good agreement with those in the literature

Comparative study of methods for extraction and purification of ...

African Journals Online (AJOL)

USER

2010-08-02

Aug 2, 2010 ... and or enzymatic lysis for direct or indirect extraction of. DNA followed by ... strength wastewater sludge in order to determine the best. DNA extraction protocol ... Ammonium acetate purification method was used to remove the.

Studies on the instrumental neutron activation analysis by cadmium ratio method and pair comparator method

Energy Technology Data Exchange (ETDEWEB)

Chao, H E; Lu, W D; Wu, S C

1977-12-01

The cadmium ratio method and pair comparator method provide a solution for the effects on the effective activation factors resulting from the variation of neutron spectrum at different irradiation positions as usually encountered in the single comparator method. The relations between the activation factors and neutron spectrum in terms of cadmium ratio of the comparator Au or of the activation factor of Co-Au pair for the elements, Sc, Cr, Mn, Co, La, Ce, Sm, and Th have been determined. The activation factors of the elements at any irradiation position can then be obtained from the cadmium ratio of the comparator and/or the activation factor of the comparator pair. The relations determined should be able to apply to different reactors and/or different positions of a reactor. It is shown that, for the isotopes /sup 46/Sc, /sup 51/Cr, /sup 56/Mn, /sup 60/Co, /sup 140/La, /sup 141/Ce, /sup 153/Sm and /sup 233/Pa, the thermal neutron activation factors determined by these two methods were generally in agreement with theoretical values. Their I/sub 0//sigma/sub th/ values appeared to agree with literature values also. The methods were applied to determine the contents of elements Sc, Cr, Mn, La, Ce, Sm, and Th in U.S.G.S. Standard Rock G-2, and the results were also in agreement with literature values. The cadmium ratio method and pair comparator method improved the single comparator method, and they are more suitable to analysis for multi-elements of a large number of samples.

Linear–Quadratic Mean-Field-Type Games: A Direct Method

Directory of Open Access Journals (Sweden)

Tyrone E. Duncan

2018-02-01

Full Text Available In this work, a multi-person mean-field-type game is formulated and solved that is described by a linear jump-diffusion system of mean-field type and a quadratic cost functional involving the second moments, the square of the expected value of the state, and the control actions of all decision-makers. We propose a direct method to solve the game, team, and bargaining problems. This solution approach does not require solving the Bellman–Kolmogorov equations or backward–forward stochastic differential equations of Pontryagin’s type. The proposed method can be easily implemented by beginners and engineers who are new to the emerging field of mean-field-type game theory. The optimal strategies for decision-makers are shown to be in a state-and-mean-field feedback form. The optimal strategies are given explicitly as a sum of the well-known linear state-feedback strategy for the associated deterministic linear–quadratic game problem and a mean-field feedback term. The equilibrium cost of the decision-makers are explicitly derived using a simple direct method. Moreover, the equilibrium cost is a weighted sum of the initial variance and an integral of a weighted variance of the diffusion and the jump process. Finally, the method is used to compute global optimum strategies as well as saddle point strategies and Nash bargaining solution in state-and-mean-field feedback form.

A new method for the direct measurement of the energy absorption coefficient of gamma rays

International Nuclear Information System (INIS)

Bradley, D.A.; Chong, C.S.; Shukri, A.; Tajuddin, A.A.; Ghose, A.M.

1988-01-01

The most important primary interaction cross section of gamma radiation which is of interest in radiation dosimetry and health physics is the energy absorption coefficient μ en of the medium under study. Direct measurement of μ en is, however, difficult and recourse is t aken to theoretical computations for its estimation. In this study a new, simple and direct method for the determination of μ en is reported. The method is based on paraxial sphere transmission using a proportional-response gamma detector. The bremsstrahlung originating from photoelectrons in the absorbing medium and fluorescence radiations from shielding etc. have been suppressed by using suitable filters. The effects of nonparaxiality of finite sample thickness have been accounted for, using extrapolation procedures. The deviation from nonproportionality and other corrections have been shown to be small. The measured value of μ en for paraffin has been determined as (3.3+-0.2)x10 -3 m 2 /Kg. This compares favourably with the theoretically computed value of 3.35 x 10 -3 m 2 /Kg given by Hubbell et al [pt

Elementary teachers' ideas about, planning for and implementation of learner-directed and teacher-directed inquiry: A mixed methods study

Science.gov (United States)

Biggers, Mandy Sue

Using a framework for variations of classroom inquiry (National Research Council [NRC], 2000, p. 29), this study explored 40 inservice elementary teachers' planning, modification, and enactment of kit-based science curriculum materials. As part of the study, a new observation protocol was modified from an existing protocol (Practices of Science Observation Protocol [P-SOP]) to measure the amount of teacher direction in science inquiry lessons (Practices of Science Observation Protocol + Directedness [P-SOPd]). An embedded mixed methods design was employed to investigate four questions: 1. How valid and reliable is the P-SOPd? 2. In what ways do inservice elementary teachers adapt existing elementary science curriculum materials across the inquiry continuum? 3. What is the relationship between the overall quality of inquiry and variations of inquiry in elementary teachers' enacted science instruction? 4. How do inservice elementary teachers' ideas about the inquiry continuum influence their adaptation of elementary science curriculum materials? Each teacher chose three lessons from a science unit for video-recorded observation, and submitted lesson plans for the three lessons. Lesson plans and videos were scored using the P-SOPd. The scores were also compared between the two protocols to determine if a correlation existed between the level of inquiry (measured on the P-SOP) and the amount of teacher direction (measured on the P-SOPd). Findings indicated no significant differences between planned and enacted lessons for the amount of teacher direction, but a correlation existed between the level of inquiry and the amount of teacher direction. In effect, the elementary teachers taught their science curriculum materials with a high level of fidelity for both the features of inquiry and the amount of teacher direction. A smaller group of three case study teachers were followed for the school year to give a more in-depth explanation of the quantitative findings. Case

Direct spraying method for fabrication of paper-based microfluidic devices

International Nuclear Information System (INIS)

Liu, Ning; An, Hong-Jie; Lew, Wen Siang; Xu, Jing; Phan, Dinh-Tuan; Hashimoto, Michinao

2017-01-01

Direct spraying of hydrophobic materials is an affordable, easy-to-use and equipment-free method for fabrication of flexible microsensors, albeit not yet widely adopted. To explore its application potential, in this paper, we propose and demonstrate two novel hybrid methods to fabricate paper-based components. Firstly, through combing direct spraying with Parafilm embedding, a leak-free paper-based sample preconcentrator for fluorescence sensing was fabricated. The leak-free device worked on the principle of ion concentration polarization (ICP) effect, and achieved enhancement of fluorescent tracer by 220 folds on a paper substrate. Secondly, by using the sprayed hydrophobic patterns, paper-based microsized supercapacitors (mSCs) were fabricated. Vacuum filtration was used to deposit multi-wall carbon nanotubes (MWCNT)-dispersed solution on a porous substrate to form electrodes. A volumetric capacitance of 42.5 mF cm −3 at a current density of 2 mA cm −3 was obtained on the paper-based mSC. Our demonstrations have shown the versatility of direct spraying for the fabrication of integrative paper-based microfluidic devices. (paper)

Using the Direct Sampling Multiple-Point Geostatistical Method for Filling Gaps in Landsat 7 ETM+ SLC-off Imagery

KAUST Repository

Yin, Gaohong

2016-05-01

Since the failure of the Scan Line Corrector (SLC) instrument on Landsat 7, observable gaps occur in the acquired Landsat 7 imagery, impacting the spatial continuity of observed imagery. Due to the highly geometric and radiometric accuracy provided by Landsat 7, a number of approaches have been proposed to fill the gaps. However, all proposed approaches have evident constraints for universal application. The main issues in gap-filling are an inability to describe the continuity features such as meandering streams or roads, or maintaining the shape of small objects when filling gaps in heterogeneous areas. The aim of the study is to validate the feasibility of using the Direct Sampling multiple-point geostatistical method, which has been shown to reconstruct complicated geological structures satisfactorily, to fill Landsat 7 gaps. The Direct Sampling method uses a conditional stochastic resampling of known locations within a target image to fill gaps and can generate multiple reconstructions for one simulation case. The Direct Sampling method was examined across a range of land cover types including deserts, sparse rural areas, dense farmlands, urban areas, braided rivers and coastal areas to demonstrate its capacity to recover gaps accurately for various land cover types. The prediction accuracy of the Direct Sampling method was also compared with other gap-filling approaches, which have been previously demonstrated to offer satisfactory results, under both homogeneous area and heterogeneous area situations. Studies have shown that the Direct Sampling method provides sufficiently accurate prediction results for a variety of land cover types from homogeneous areas to heterogeneous land cover types. Likewise, it exhibits superior performances when used to fill gaps in heterogeneous land cover types without input image or with an input image that is temporally far from the target image in comparison with other gap-filling approaches.

Direct methods of solution for problems in mechanics from invariance principles

International Nuclear Information System (INIS)

Rajan, M.

1986-01-01

Direct solutions to problems in mechanics are developed from variational statements derived from the principle of invariance of the action integral under a one-parameter family of infinitesimal transformations. Exact, direct solution procedures for linear systems are developed by a careful choice of the arbitrary functions used to generate the infinitesimal transformations. It is demonstrated that the well-known methods for the solution of differential equations can be directly adapted to the required variational statements. Examples in particle and continuum mechanics are presented

Mutant fatty acid desaturase and methods for directed mutagenesis

Science.gov (United States)

Shanklin, John [Shoreham, NY; Whittle, Edward J [Greenport, NY

2008-01-29

The present invention relates to methods for producing fatty acid desaturase mutants having a substantially increased activity towards substrates with fewer than 18 carbon atom chains relative to an unmutagenized precursor desaturase having an 18 carbon chain length specificity, the sequences encoding the desaturases and to the desaturases that are produced by the methods. The present invention further relates to a method for altering a function of a protein, including a fatty acid desaturase, through directed mutagenesis involving identifying candidate amino acid residues, producing a library of mutants of the protein by simultaneously randomizing all amino acid candidates, and selecting for mutants which exhibit the desired alteration of function. Candidate amino acids are identified by a combination of methods. Enzymatic, binding, structural and other functions of proteins can be altered by the method.

The linogram algorithm and direct fourier method with linograms

International Nuclear Information System (INIS)

Edholm, P.R.

1990-01-01

This text is an attempt to describe the linogram algorithm based on a somewhat simplified mathematical description of the algorithm which is also more similar to the actual digital implementation. Another algorithm with linograms, which may be called a direct fourier method is also presented. (K.A.E.)

[The comparative assessment of the practical value of the currently employed methods for the recognition and species specificity of the blood].

Science.gov (United States)

Grezina, N Iu; Suleĭmenova, G M

2011-01-01

The objective of the present study was to evaluate sensitivity and specificity of the HemDirect method on test-plates (Seratec) for detecting human hemoglobin (HHb). These characteristics were compared with those of other widely used methods designed for the detection of blood traces, viz. thin layer chromatography, hemotest, spectrofluorimetry, and identification of blood species specificity (by countercurrent immunoelectrophoresis in agar and on the acetate-cellulose film). It was shown that the HemDirect test is highly specific and far more sensitive than other techniques used for the same purpose in the practical work. It can be recommended as the method of choice for the detection of blood microtraces.

SOCIAL RESPONSIBILITY OF UKRAINIAN UNIVERSITIES: COMPARATIVE ANALYSIS AND MAIN DIRECTIONS OF DEVELOPMENT

Directory of Open Access Journals (Sweden)

O. Grishnova

2014-04-01

Full Text Available The paper encapsulates the essence of university social responsibility. The study explores basic directions of universities social responsible activities in Ukraine and in western countries. A comparative assessment is conducted as to distribution of social responsibility in national universities activities. The paper specifies priority areas of social responsibility education.

Composition Medium Comparability in a Direct Writing Assessment of Non-Native English Speakers

Directory of Open Access Journals (Sweden)

Edward W. Wolfe

2004-01-01

Full Text Available The Test of English as a Foreign Language (TOEFL contains a direct writing assessment, and examinees are given the option of composing their responses at a computer terminal using a keyboard or composing their responses in handwriting. This study sought to determine whether performance on a direct writing assessment is comparable for examinees when given the choice to compose essays in handwriting versus word processing. We examined this relationship controlling for English language proficiency and several demographic characteristics of examinees using linear models. We found a weak two-way interaction between composition medium and English language proficiency with examinees with weaker English language scores performing better on handwritten essays while examinees with better English language scores performing comparably on the two testing media. We also observed predictable differences associated with geographic region, native language, gender, and age.

Comparative evaluation of four different sterilization methods on contaminated endodontic files

Directory of Open Access Journals (Sweden)

Malathi Yenni

2017-01-01

Full Text Available Background: The reuse of instruments in the field of endodontics leads to cross infection due to contamination with microbes as the instruments come into direct contact with saliva, blood, and infected tissues. Since microbes are considered to be the major cause of endodontic failures, sterilization of endodontic instruments is mandatory for maintaining asepsis to prevent cross-contamination from one person to other. Hence, the present study was conducted to compare the effectiveness of four different methods of sterilizing contaminated endodontic files. Materials and Methods: A total of 48 stainless steel K files were divided into four groups based on the sterilization method followed – Group A: Autoclave, Group B: Glass bead sterilization, Group C: Glutaraldehyde, and Group D: Quitanet Plus (aldehyde-free solution. In all the tested groups, half of the files were contaminated with Escherichia coli and remaining with Enterococcus faecalis. Then, presterilization colony counts were recorded, followed by sterilization through respective methods. Later, the sterilized files were rinsed with distilled water and 100 ul of the diluted concentration was transferred and cultured onto the respective agar plates to determine the total microbial reduction. Results: Autoclave showed complete effectiveness in reducing the microbial count followed by Quitanet Plus, glass bead sterilizer, and glutaraldehyde. Conclusion: Autoclave is considered to be the best sterilization technique to prevent cross infection in endodontic therapy.

Direct integral linear least square regression method for kinetic evaluation of hepatobiliary scintigraphy

International Nuclear Information System (INIS)

Shuke, Noriyuki

1991-01-01

In hepatobiliary scintigraphy, kinetic model analysis, which provides kinetic parameters like hepatic extraction or excretion rate, have been done for quantitative evaluation of liver function. In this analysis, unknown model parameters are usually determined using nonlinear least square regression method (NLS method) where iterative calculation and initial estimate for unknown parameters are required. As a simple alternative to NLS method, direct integral linear least square regression method (DILS method), which can determine model parameters by a simple calculation without initial estimate, is proposed, and tested the applicability to analysis of hepatobiliary scintigraphy. In order to see whether DILS method could determine model parameters as good as NLS method, or to determine appropriate weight for DILS method, simulated theoretical data based on prefixed parameters were fitted to 1 compartment model using both DILS method with various weightings and NLS method. The parameter values obtained were then compared with prefixed values which were used for data generation. The effect of various weights on the error of parameter estimate was examined, and inverse of time was found to be the best weight to make the error minimum. When using this weight, DILS method could give parameter values close to those obtained by NLS method and both parameter values were very close to prefixed values. With appropriate weighting, the DILS method could provide reliable parameter estimate which is relatively insensitive to the data noise. In conclusion, the DILS method could be used as a simple alternative to NLS method, providing reliable parameter estimate. (author)

A SOM clustering pattern sequence-based next symbol prediction method for day-ahead direct electricity load and price forecasting

International Nuclear Information System (INIS)

Jin, Cheng Hao; Pok, Gouchol; Lee, Yongmi; Park, Hyun-Woo; Kim, Kwang Deuk; Yun, Unil; Ryu, Keun Ho

2015-01-01

Highlights: • A novel pattern sequence-based direct time series forecasting method was proposed. • Due to the use of SOM’s topology preserving property, only SOM can be applied. • SCPSNSP only deals with the cluster patterns not each specific time series value. • SCPSNSP performs better than recently developed forecasting algorithms. - Abstract: In this paper, we propose a new day-ahead direct time series forecasting method for competitive electricity markets based on clustering and next symbol prediction. In the clustering step, pattern sequence and their topology relations are obtained from self organizing map time series clustering. In the next symbol prediction step, with each cluster label in the pattern sequence represented as a pair of its topologically identical coordinates, artificial neural network is used to predict the topological coordinates of next day by training the relationship between previous daily pattern sequence and its next day pattern. According to the obtained topology relations, the nearest nonzero hits pattern is assigned to next day so that the whole time series values can be directly forecasted from the assigned cluster pattern. The proposed method was evaluated on Spanish, Australian and New York electricity markets and compared with PSF and some of the most recently published forecasting methods. Experimental results show that the proposed method outperforms the best forecasting methods at least 3.64%

Comparing Methods for Cardiac Output

DEFF Research Database (Denmark)

Graeser, Karin; Zemtsovski, Mikhail; Kofoed, Klaus F

2018-01-01

of the left ventricular outflow tract. METHODS: The primary aim was a systematic comparison of CO with Doppler-derived 3D TEE and CO by thermodilution in a broad population of patients undergoing cardiac surgery. A subanalysis was performed comparing cross-sectional area by TEE with cardiac computed...... tomography (CT) angiography. Sixty-two patients, scheduled for elective heart surgery, were included; 1 was subsequently excluded for logistic reasons. Inclusion criteria were coronary artery bypass surgery (N = 42) and aortic valve replacement (N = 19). Exclusion criteria were chronic atrial fibrillation......, left ventricular ejection fraction below 0.40 and intracardiac shunts. Nineteen randomly selected patients had a cardiac CT the day before surgery. All images were stored for blinded post hoc analyses, and Bland-Altman plots were used to assess agreement between measurement methods, defined as the bias...

Dimensionality Reduction Methods: Comparative Analysis of methods PCA, PPCA and KPCA

Directory of Open Access Journals (Sweden)

Jorge Arroyo-Hernández

2016-01-01

Full Text Available The dimensionality reduction methods are algorithms mapping the set of data in subspaces derived from the original space, of fewer dimensions, that allow a description of the data at a lower cost. Due to their importance, they are widely used in processes associated with learning machine. This article presents a comparative analysis of PCA, PPCA and KPCA dimensionality reduction methods. A reconstruction experiment of worm-shape data was performed through structures of landmarks located in the body contour, with methods having different number of main components. The results showed that all methods can be seen as alternative processes. Nevertheless, thanks to the potential for analysis in the features space and the method for calculation of its preimage presented, KPCA offers a better method for recognition process and pattern extraction

Urea ammoniation compared to urea supplementation as a method ...

African Journals Online (AJOL)

Urea ammoniation compared to urea supplementation as a method of improving the nutritive value of wheat straw for sheep. S.W.P. Cloete, N.M. Kritzinger. Winter Rainfall Region, Eisenburg. The ammoniation of wheat straw by urea in a stack method was in- vestigated and compared to urea supplemented and untreated ...

Lipidomic analysis of biological samples: Comparison of liquid chromatography, supercritical fluid chromatography and direct infusion mass spectrometry methods.

Science.gov (United States)

Lísa, Miroslav; Cífková, Eva; Khalikova, Maria; Ovčačíková, Magdaléna; Holčapek, Michal

2017-11-24

Lipidomic analysis of biological samples in a clinical research represents challenging task for analytical methods given by the large number of samples and their extreme complexity. In this work, we compare direct infusion (DI) and chromatography - mass spectrometry (MS) lipidomic approaches represented by three analytical methods in terms of comprehensiveness, sample throughput, and validation results for the lipidomic analysis of biological samples represented by tumor tissue, surrounding normal tissue, plasma, and erythrocytes of kidney cancer patients. Methods are compared in one laboratory using the identical analytical protocol to ensure comparable conditions. Ultrahigh-performance liquid chromatography/MS (UHPLC/MS) method in hydrophilic interaction liquid chromatography mode and DI-MS method are used for this comparison as the most widely used methods for the lipidomic analysis together with ultrahigh-performance supercritical fluid chromatography/MS (UHPSFC/MS) method showing promising results in metabolomics analyses. The nontargeted analysis of pooled samples is performed using all tested methods and 610 lipid species within 23 lipid classes are identified. DI method provides the most comprehensive results due to identification of some polar lipid classes, which are not identified by UHPLC and UHPSFC methods. On the other hand, UHPSFC method provides an excellent sensitivity for less polar lipid classes and the highest sample throughput within 10min method time. The sample consumption of DI method is 125 times higher than for other methods, while only 40μL of organic solvent is used for one sample analysis compared to 3.5mL and 4.9mL in case of UHPLC and UHPSFC methods, respectively. Methods are validated for the quantitative lipidomic analysis of plasma samples with one internal standard for each lipid class. Results show applicability of all tested methods for the lipidomic analysis of biological samples depending on the analysis requirements

Comparison of the direct enzyme assay method with the membrane ...

African Journals Online (AJOL)

Comparison of the direct enzyme assay method with the membrane filtration technique in the quantification and monitoring of microbial indicator organisms – seasonal variations in the activities of coliforms and E. coli, temperature and pH.

Determination of the response time of pressure transducers using the direct method

International Nuclear Information System (INIS)

Perillo, S.R.P.

1994-01-01

The available methods to determine the response time of nuclear safety related pressure transducers are discussed, with emphasis to the direct method. In order to perform the experiments, a Hydraulic Ramp Generator was built. The equipment produces ramp pressure transients simultaneously to a reference transducer and to the transducer under test. The time lag between the output of the two transducers, when they reach a predetermined setpoint, is measured as the time delay of the transducer under test. Some results using the direct method to determine the time delay of pressure transducers (1 E Class Conventional) are presented. (author). 18 refs, 35 figs, 12 tabs

Book Review: Comparative Education Research: Approaches and Methods

Directory of Open Access Journals (Sweden)

Noel Mcginn

2014-10-01

Full Text Available Book Review Comparative Education Research: Approaches and Methods (2nd edition By Mark Bray, Bob Adamson and Mark Mason (Eds. (2014, 453p ISBN: 978-988-17852-8-2, Hong Kong: Comparative Education Research Centre and Springer

Comparability among four invertebrate sampling methods and two multimetric indexes, Fountain Creek Basin, Colorado, 2010–2012

Science.gov (United States)

Bruce, James F.; Roberts, James J.; Zuellig, Robert E.

2018-05-24

The U.S. Geological Survey (USGS), in cooperation with Colorado Springs City Engineering and Colorado Springs Utilities, analyzed previously collected invertebrate data to determine the comparability among four sampling methods and two versions (2010 and 2017) of the Colorado Benthic Macroinvertebrate Multimetric Index (MMI). For this study, annual macroinvertebrate samples were collected concurrently (in space and time) at 15 USGS surface-water gaging stations in the Fountain Creek Basin from 2010 to 2012 using four sampling methods. The USGS monitoring project in the basin uses two of the methods and the Colorado Department of Public Health and Environment recommends the other two. These methods belong to two distinct sample types, one that targets single habitats and one that targets multiple habitats. The study results indicate that there are significant differences in MMI values obtained from the single-habitat and multihabitat sample types but methods from each program within each sample type produced comparable values. This study also determined that MMI values calculated by different versions of the Colorado Benthic Macroinvertebrate MMI are indistinguishable. This indicates that the Colorado Department of Public Health and Environment methods are comparable with the USGS monitoring project methods for single-habitat and multihabitat sample types. This report discusses the direct application of the study results to inform the revision of the existing USGS monitoring project in the Fountain Creek Basin.

Comparative safety of direct oral anticoagulants and warfarin in venous thromboembolism: multicentre, population based, observational study.

Science.gov (United States)

Jun, Min; Lix, Lisa M; Durand, Madeleine; Dahl, Matt; Paterson, J Michael; Dormuth, Colin R; Ernst, Pierre; Yao, Shenzhen; Renoux, Christel; Tamim, Hala; Wu, Cynthia; Mahmud, Salaheddin M; Hemmelgarn, Brenda R

2017-10-17

Objective  To determine the safety of direct oral anticoagulant (DOAC) use compared with warfarin use for the treatment of venous thromboembolism. Design  Retrospective matched cohort study conducted between 1 January 2009 and 31 March 2016. Setting  Community based, using healthcare data from six jurisdictions in Canada and the United States. Participants  59 525 adults (12 489 DOAC users; 47 036 warfarin users) with a new diagnosis of venous thromboembolism and a prescription for a DOAC or warfarin within 30 days of diagnosis. Main outcome measures  Outcomes included hospital admission or emergency department visit for major bleeding and all cause mortality within 90 days after starting treatment. Propensity score matching and shared frailty models were used to estimate adjusted hazard ratios of the outcomes comparing DOACs with warfarin. Analyses were conducted independently at each site, with meta-analytical methods used to estimate pooled hazard ratios across sites. Results  Of the 59 525 participants, 1967 (3.3%) had a major bleed and 1029 (1.7%) died over a mean follow-up of 85.2 days. The risk of major bleeding was similar for DOAC compared with warfarin use (pooled hazard ratio 0.92, 95% confidence interval 0.82 to 1.03), with the overall direction of the association favouring DOAC use. No difference was found in the risk of death (pooled hazard ratio 0.99, 0.84 to 1.16) for DOACs compared with warfarin use. There was no evidence of heterogeneity across centres, between patients with and without chronic kidney disease, across age groups, or between male and female patients. Conclusions  In this analysis of adults with incident venous thromboembolism, treatment with DOACs, compared with warfarin, was not associated with an increased risk of major bleeding or all cause mortality in the first 90 days of treatment. Trial registration  Clinical trials NCT02833987. Published by the BMJ Publishing Group Limited. For permission to use (where not

Context-dependent impairment of recollection in list-method directed forgetting.

Science.gov (United States)

Hanczakowski, Maciej; Pasek, Tomasz; Zawadzka, Katarzyna

2012-01-01

In list-method directed forgetting, people's ability to forget one of the sets of learned material is examined. Research shows that memory for to-be-forgotten items is impaired when assessed by a recall test and by recognition tests reliant on recollective processes. Retrieval inhibition and context-change mechanisms have been proposed to account for the directed forgetting effects and both of them account for the results obtained with recognition tests. However, the context change account makes a specific prediction that recollection is impaired by directed forgetting only if it makes use of contextual associations. In the present study, directed forgetting was examined with two types of recollection-based tasks making use of different types of associations, namely a list discrimination task utilising contextual associations and an associative recognition task utilising interitem associations. Consistent with the context change account, the costs of directed forgetting were observed in a list discrimination task and were not observed in an associative recognition task. The results indicate that impairment in recollection due to directed forgetting is not general and provide converging evidence to support the context-change account.

Proximal Alternating Direction Method with Relaxed Proximal Parameters for the Least Squares Covariance Adjustment Problem

Directory of Open Access Journals (Sweden)

Minghua Xu

2014-01-01

Full Text Available We consider the problem of seeking a symmetric positive semidefinite matrix in a closed convex set to approximate a given matrix. This problem may arise in several areas of numerical linear algebra or come from finance industry or statistics and thus has many applications. For solving this class of matrix optimization problems, many methods have been proposed in the literature. The proximal alternating direction method is one of those methods which can be easily applied to solve these matrix optimization problems. Generally, the proximal parameters of the proximal alternating direction method are greater than zero. In this paper, we conclude that the restriction on the proximal parameters can be relaxed for solving this kind of matrix optimization problems. Numerical experiments also show that the proximal alternating direction method with the relaxed proximal parameters is convergent and generally has a better performance than the classical proximal alternating direction method.

Direct estimation of diffuse gaseous emissions from coal fires: current methods and future directions

Science.gov (United States)

Engle, Mark A.; Olea, Ricardo A.; O'Keefe, Jennifer M. K.; Hower, James C.; Geboy, Nicholas J.

2013-01-01

Coal fires occur in nature spontaneously, contribute to increases in greenhouse gases, and emit atmospheric toxicants. Increasing interest in quantifying coal fire emissions has resulted in the adaptation and development of specialized approaches and adoption of numerical modeling techniques. Overview of these methods for direct estimation of diffuse gas emissions from coal fires is presented in this paper. Here we take advantage of stochastic Gaussian simulation to interpolate CO2 fluxes measured using a dynamic closed chamber at the Ruth Mullins coal fire in Perry County, Kentucky. This approach allows for preparing a map of diffuse gas emissions, one of the two primary ways that gases emanate from coal fires, and establishing the reliability of the study both locally and for the entire fire. Future research directions include continuous and automated sampling to improve quantification of gaseous coal fire emissions.

A Comparative Study of Control Methods for a Robotic Manipulator with Six DOF in Simulation

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Smyrnaiou Georgia P.

2017-01-01

Full Text Available In this paper a comparative study of the classical control methods for the testing of a mathematical model, which controls six actuators of a six degrees of freedom robotic arm with a single controller, is illustrated, aiming to the constructive simplification of the system. In more detail, a mathematical model of the system is designed which simulates all mechanical parts, including 5-way directional pneumatic valve, the pneumatic actuators/pistons and the mathematical model of the controller. The purpose of the above is the tuning of a Single Input, Multiple Output (SIMO controller which will direct the motion of the six pneumatic pistons. The thorough analysis of the implementation of the pneumatic system in Matlab/Simulink environment is followed by experimentation and results using Proportional (P, Proportional-Integral (PI, Proportional-Derivative (PD and Proportional-Integral-Derivative (PID controllers. The simulation results show the advantages of the above classical control methods on the robotic human arm which imitating human motion and made by a well-known company in the field of pneumatic automation.

An accuracy measurement method for star trackers based on direct astronomic observation.

Science.gov (United States)

Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

2016-03-07

Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.

The Trojan Horse method for nuclear astrophysics: Recent results for direct reactions

International Nuclear Information System (INIS)

Tumino, A.; Gulino, M.; Spitaleri, C.; Cherubini, S.; Romano, S.; Cognata, M. La; Pizzone, R. G.; Rapisarda, G. G.; Lamia, L.

2014-01-01

The Trojan Horse method is a powerful indirect technique to determine the astrophysical factor for binary rearrangement processes A+x→b+B at astrophysical energies by measuring the cross section for the Trojan Horse (TH) reaction A+a→B+b+s in quasi free kinematics. The Trojan Horse Method has been successfully applied to many reactions of astrophysical interest, both direct and resonant. In this paper, we will focus on direct sub-processes. The theory of the THM for direct binary reactions will be shortly presented based on a few-body approach that takes into account the off-energy-shell effects and initial and final state interactions. Examples of recent results will be presented to demonstrate how THM works experimentally

The Trojan Horse method for nuclear astrophysics: Recent results for direct reactions

Energy Technology Data Exchange (ETDEWEB)

Tumino, A.; Gulino, M. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy and Università degli Studi di Enna Kore, Enna (Italy); Spitaleri, C.; Cherubini, S.; Romano, S. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy and Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy); Cognata, M. La; Pizzone, R. G.; Rapisarda, G. G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Lamia, L. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy)

2014-05-09

The Trojan Horse method is a powerful indirect technique to determine the astrophysical factor for binary rearrangement processes A+x→b+B at astrophysical energies by measuring the cross section for the Trojan Horse (TH) reaction A+a→B+b+s in quasi free kinematics. The Trojan Horse Method has been successfully applied to many reactions of astrophysical interest, both direct and resonant. In this paper, we will focus on direct sub-processes. The theory of the THM for direct binary reactions will be shortly presented based on a few-body approach that takes into account the off-energy-shell effects and initial and final state interactions. Examples of recent results will be presented to demonstrate how THM works experimentally.

A direct sampling method to an inverse medium scattering problem

KAUST Repository

Ito, Kazufumi; Jin, Bangti; Zou, Jun

2012-01-01

In this work we present a novel sampling method for time harmonic inverse medium scattering problems. It provides a simple tool to directly estimate the shape of the unknown scatterers (inhomogeneous media), and it is applicable even when

Direct LSC method for determination of bio-origin by C-14 measurement

International Nuclear Information System (INIS)

Kristof, Romana; Kozar Logar, Jasmina

2017-01-01

The aim of the research was to test the generalized direct liquid scintillation spectrometry (LSC) method for bio-origin determination by measurement of C-14. Examples of diversified items with known and unknown bio-origin were measured by liquid scintillation counting and analyzed by procedures, developed for fuel samples. Bio-origin of fuels, lubricants and monomer resins were successfully determined via direct LSC method after simple sample preparation with acceptable accuracy and trueness despite their diversity in color, viscosity, density or chemical composition. (author)

Numerical simulation of spray coalescence in an Eulerian framework: Direct quadrature method of moments and multi-fluid method

International Nuclear Information System (INIS)

Fox, R.O.; Laurent, F.; Massot, M.

2008-01-01

The scope of the present study is Eulerian modeling and simulation of polydisperse liquid sprays undergoing droplet coalescence and evaporation. The fundamental mathematical description is the Williams spray equation governing the joint number density function f(v,u;x,t) of droplet volume and velocity. Eulerian multi-fluid models have already been rigorously derived from this equation in Laurent et al. [F. Laurent, M. Massot, P. Villedieu, Eulerian multi-fluid modeling for the numerical simulation of coalescence in polydisperse dense liquid sprays, J. Comput. Phys. 194 (2004) 505-543]. The first key feature of the paper is the application of direct quadrature method of moments (DQMOM) introduced by Marchisio and Fox [D.L. Marchisio, R.O. Fox, Solution of population balance equations using the direct quadrature method of moments, J. Aerosol Sci. 36 (2005) 43-73] to the Williams spray equation. Both the multi-fluid method and DQMOM yield systems of Eulerian conservation equations with complicated interaction terms representing coalescence. In order to focus on the difficulties associated with treating size-dependent coalescence and to avoid numerical uncertainty issues associated with two-way coupling, only one-way coupling between the droplets and a given gas velocity field is considered. In order to validate and compare these approaches, the chosen configuration is a self-similar 2D axisymmetrical decelerating nozzle with sprays having various size distributions, ranging from smooth ones up to Dirac delta functions. The second key feature of the paper is a thorough comparison of the two approaches for various test-cases to a reference solution obtained through a classical stochastic Lagrangian solver. Both Eulerian models prove to describe adequately spray coalescence and yield a very interesting alternative to the Lagrangian solver. The third key point of the study is a detailed description of the limitations associated with each method, thus giving criteria for

Comparative evaluation of cone-beam computed tomography versus direct surgical measurements in the diagnosis of mandibular molar furcation involvement

Directory of Open Access Journals (Sweden)

Shyam Padmanabhan

2017-01-01

Full Text Available Aim: Periodontists frequently experience inconvenience in accurate assessment and treatment of furcation areas affected by periodontal disease. Furcation involvement (FI most commonly affects the mandibular molars. Diagnosis of furcation-involved teeth is mainly by the assessment of probing pocket depth, clinical attachment level, furcation entrance probing, and intraoral periapical radiographs. Three-dimensional imaging has provided advantage to the clinician in assessment of bone morphology. Thus, the present study aimed to compare the diagnostic efficacy of cone-beam computed tomography (CBCT as against direct intrasurgical measurements of furcation defects in mandibular molars. Subjects and Methods: Study population included 14 patients with 25 mandibular molar furcation sites. CBCT was performed to measure height, width, and depth of furcation defects of mandibular molars with Grade II and Grade III FI. Intrasurgical measurements of the FI were assessed during periodontal flap surgery in indicated teeth which were compared with CBCT measurements. Statistical analysis was done using paired t-test and Bland–Altman plot. Results: The CBCT versus intrasurgical furcation measurements were 2.18 ± 0.86 mm and 2.30 ± 0.89 mm for furcation height, 1.87 ± 0.52 mm and 1.84 ± 0.49 mm for furcation width, and 3.81 ± 1.37 mm and 4.05 ± 1.49 mm for furcation depth, respectively. Results showed that there was no statistical significance between the measured parameters, indicating that the two methods were statistically similar. Conclusion: Accuracy of assessment of mandibular molar FI by CBCT was comparable to that of direct surgical measurements. These findings indicate that CBCT is an excellent adjunctive diagnostic tool in periodontal treatment planning.

[Laboratory diagnosis of genital herpes--direct immunofluorescence method].

Science.gov (United States)

Majewska, Anna; Romejko-Wolniewicz, Ewa; Zareba-Szczudlik, Julia; Kilijańczyk, Marek; Gajewska, Małgorzata; Młynarczyk, Grazyna

2013-07-01

Aim of the study was to determine clinical usefulness of direct immunofluorescence method in the laboratory diagnosis of genital herpes in women. Overall 187 anogenital swabs were collected from 120 women. Using a dacron-tipped applicator 83 swabs were collected from women suspected of genital herpes and 104 from patients with no signs of genital infection. All samples were tested using cell culture (Vero cell line) and then direct immunofluorescence method (DIF) for the identification of antigens of herpes simplex viruses: HSV-1 and HSV-2. Characteristic cytopathic effect (CPE), indicative of alphaherpesvirus infection, was observed in 43.4% of cultures with clinical specimens collected from women with suspected genital herpes and in 29.8% of cultures of clinical specimens taken from patients with no clinical symptoms of genital herpes. Herpes simplex viruses were determined in 73 samples by direct immunofluorescence method after amplification of the virus in cell culture. The DIF test confirmed the diagnosis based on the microscopic CPE observation in 85%. In 15% of samples (taken from pregnant women without clinical signs of infection) we reported positive immunofluorescence in the absence of CPE. The frequency of antigen detection was statistically significantly higher in samples that were positive by culture study (chi-square test with Yates's correction, p genital herpes in swabs taken from the vestibule of the vagina and the vulva. However, there was no statistically significant difference in the frequency of detection of Herpes Simplex Virus antigens in specimens from different parts of the genital tract in both groups of women (chi-square test, p > 0.05). In our study HHV-1 was the main causative agent of genital herpes. The growing worldwide prevalence of genital herpes, challenges with the clinical diagnosis, and availability of effective antiviral therapy are the main reasons for a growing interest in rapid, proper laboratory diagnosis of infected

A direction of developing a mining method and mining complexes

Energy Technology Data Exchange (ETDEWEB)

Gabov, V.V.; Efimov, I.A. [St. Petersburg State Mining Institute, St. Petersburg (Russian Federation). Vorkuta Branch

1996-12-31

The analyses of a mining method as a main factor determining the development stages of mining units is presented. The paper suggests a perspective mining method which differs from the known ones by following peculiarities: the direction selectivity of cuts with regard to coal seams structure; the cutting speed, thickness and succession of dusts. This method may be done by modulate complexes (a shield carrying a cutting head for coal mining), their mining devices being supplied with hydraulic drive. An experimental model of the module complex has been developed. 2 refs.

Methods for Specific Electrode Resistance Measurement during Transcranial Direct Current Stimulation

Science.gov (United States)

Khadka, Niranjan; Rahman, Asif; Sarantos, Chris; Truong, Dennis Q.; Bikson, Marom

2014-01-01

Background Transcranial Direct Current Stimulation (tDCS) is investigated to treat a wide range of neuropsychiatric disorders, for rehabilitation, and for enhancing cognitive performance. The monitoring of electrode resistance before and during tDCS is considered important for tolerability and safety, where an unusually high resistance is indicative of undesired electrode or poor skin contact conditions. Conventional resistance measurement methods do not isolate individual electrode resistance but rather measures overall voltage. Moreover, for HD-tDCS devices, cross talk across electrodes makes concurrent resistance monitoring unreliable. Objective We propose a novel method for monitoring of the individual electrode resistance during tDCS, using a super-position of direct current with a test-signal (low-intensity and low-frequency sinusoids with electrode– specific frequencies) and a single sentinel electrode (not used for DC). Methods To validate this methodology, we developed lumped-parameter models of two and multi-electrode tDCS. Approaches with and without a sentinel electrode were solved and underlying assumptions identified. Assumptions were tested and parameterized in healthy participants using forearm stimulation combining tDCS (2 mA) and sinusoidal test-signals (38 μA and 76 μA peak to peak at 1 Hz, 10 Hz, and 100 Hz) and an in vitro test (where varied electrode failure modes were created). DC and AC component voltages across the electrodes were compared and participants were asked to rate subjective pain. Results A sentinel electrode is required to isolate electrode resistance in a two-electrode tDCS system. For multi-electrode resistance tracking, cross talk was aggravated with electrode proximity and current/resistance mismatches, but could be corrected using proposed approaches. Average voltage and average pain scores were not significantly different across test current intensities and frequencies (two-way repeated measures ANOVA) indicating the

Evaluating direct medical expenditures estimation methods of adults using the medical expenditure panel survey: an example focusing on head and neck cancer.

Science.gov (United States)

Coughlan, Diarmuid; Yeh, Susan T; O'Neill, Ciaran; Frick, Kevin D

2014-01-01

To inform policymakers of the importance of evaluating various methods for estimating the direct medical expenditures for a low-incidence condition, head and neck cancer (HNC). Four methods of estimation have been identified: 1) summing all health care expenditures, 2) estimating disease-specific expenditures consistent with an attribution approach, 3) estimating disease-specific expenditures by matching, and 4) estimating disease-specific expenditures by using a regression-based approach. A literature review of studies (2005-2012) that used the Medical Expenditure Panel Survey (MEPS) was undertaken to establish the most popular expenditure estimation methods. These methods were then applied to a sample of 120 respondents with HNC, derived from pooled data (2003-2008). The literature review shows that varying expenditure estimation methods have been used with MEPS but no study compared and contrasted all four methods. Our estimates are reflective of the national treated prevalence of HNC. The upper-bound estimate of annual direct medical expenditures of adult respondents with HNC between 2003 and 2008 was $3.18 billion (in 2008 dollars). Comparable estimates arising from methods focusing on disease-specific and incremental expenditures were all lower in magnitude. Attribution yielded annual expenditures of $1.41 billion, matching method of $1.56 billion, and regression method of $1.09 billion. This research demonstrates that variation exists across and within expenditure estimation methods applied to MEPS data. Despite concerns regarding aspects of reliability and consistency, reporting a combination of the four methods offers a degree of transparency and validity to estimating the likely range of annual direct medical expenditures of a condition. © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Published by International Society for Pharmacoeconomics and Outcomes Research (ISPOR) All rights reserved.

Evaluation of three sample preparation methods for the direct identification of bacteria in positive blood cultures by MALDI-TOF.

Science.gov (United States)

Tanner, Hannah; Evans, Jason T; Gossain, Savita; Hussain, Abid

2017-01-18

Patient mortality is significantly reduced by rapid identification of bacteria from sterile sites. MALDI-TOF can identify bacteria directly from positive blood cultures and multiple sample preparation methods are available. We evaluated three sample preparation methods and two MALDI-TOF score cut-off values. Positive blood culture bottles with organisms present in Gram stains were prospectively analysed by MALDI-TOF. Three lysis reagents (Saponin, SDS, and SepsiTyper lysis bufer) were applied to each positive culture followed by centrifugation, washing and protein extraction steps. Methods were compared using the McNemar test and 16S rDNA sequencing was used to assess discordant results. In 144 monomicrobial cultures, using ≥2.000 as the cut-off value, species level identifications were obtained from 69/144 (48%) samples using Saponin, 86/144 (60%) using SDS, and 91/144 (63%) using SepsiTyper. The difference between SDS and SepsiTyper was not statistically significant (P = 0.228). Differences between Saponin and the other two reagents were significant (P direct MALDI-TOF identification were observed in monomicrobial cultures. In 32 polymicrobial cultures, MALDI-TOF identified one organism in 34-75% of samples depending on the method. This study demonstrates two inexpensive in-house detergent lysis methods are non-inferior to a commercial kit for analysis of positive blood cultures by direct MALDI-TOF in a clinical diagnostic microbiology laboratory.

Comparative study of mechanical properties of direct core build-up materials

Directory of Open Access Journals (Sweden)

Girish Kumar

2015-01-01

Full Text Available Background and Objectives: The strength greatly influences the selection of core material because core must withstand forces due to mastication and para-function for many years. This study was conducted to evaluate certain mechanical properties of commonly used materials for direct core build-up, including visible light cured composite, polyacid modified composite, resin modified glass ionomer, high copper amalgam, and silver cermet cement. Materials and Methods: All the materials were manipulated according to the manufacturer′s recommendations and standard test specimens were prepared. A universal testing machine at different cross-head speed was used to determine all the four mechanical properties. Mean compressive strength, diametral tensile strength, flexural strength, and elastic modulus with standard deviations were calculated. Multiple comparisons of the materials were also done. Results: Considerable differences in compressive strength, diametral tensile strength, and flexural strength were observed. Visible light cured composite showed relatively high compressive strength, diametral tensile strength, and flexural strength compared with the other tested materials. Amalgam showed the highest value for elastic modulus. Silver cermet showed less value for all the properties except for elastic modulus. Conclusions: Strength is one of the most important criteria for selection of a core material. Stronger materials better resist deformation and fracture provide more equitable stress distribution, greater stability, and greater probability of clinical success.

Methods for the comparative evaluation of pharmaceuticals

Directory of Open Access Journals (Sweden)

Busse, Reinhard

2005-11-01

Full Text Available Political background: As a German novelty, the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen; IGWiG was established in 2004 to, among other tasks, evaluate the benefit of pharmaceuticals. In this context it is of importance that patented pharmaceuticals are only excluded from the reference pricing system if they offer a therapeutic improvement. The institute is commissioned by the Federal Joint Committee (Gemeinsamer Bundesausschuss, G-BA or by the Ministry of Health and Social Security. The German policy objective expressed by the latest health care reform (Gesetz zur Modernisierung der Gesetzlichen Krankenversicherung, GMG is to base decisions on a scientific assessment of pharmaceuticals in comparison to already available treatments. However, procedures and methods are still to be established. Research questions and methods: This health technology assessment (HTA report was commissioned by the German Agency for HTA at the Institute for Medical Documentation and Information (DAHTA@DIMDI. It analysed criteria, procedures, and methods of comparative drug assessment in other EU-/OECD-countries. The research question was the following: How do national public institutions compare medicines in connection with pharmaceutical regulation, i.e. licensing, reimbursement and pricing of drugs? Institutions as well as documents concerning comparative drug evaluation (e.g. regulations, guidelines were identified through internet, systematic literature, and hand searches. Publications were selected according to pre-defined inclusion and exclusion criteria. Documents were analysed in a qualitative matter following an analytic framework that had been developed in advance. Results were summarised narratively and presented in evidence tables. Results and discussion: Currently licensing agencies do not systematically assess a new drug's added value for patients and society. This is why many

Directed forgetting of complex pictures in an item method paradigm.

Science.gov (United States)

Hauswald, Anne; Kissler, Johanna

2008-11-01

An item-cued directed forgetting paradigm was used to investigate the ability to control episodic memory and selectively encode complex coloured pictures. A series of photographs was presented to 21 participants who were instructed to either remember or forget each picture after it was presented. Memory performance was later tested with a recognition task where all presented items had to be retrieved, regardless of the initial instructions. A directed forgetting effect--that is, better recognition of "to-be-remembered" than of "to-be-forgotten" pictures--was observed, although its size was smaller than previously reported for words or line drawings. The magnitude of the directed forgetting effect correlated negatively with participants' depression and dissociation scores. The results indicate that, at least in an item method, directed forgetting occurs for complex pictures as well as words and simple line drawings. Furthermore, people with higher levels of dissociative or depressive symptoms exhibit altered memory encoding patterns.

Comparing electron tomography and HRTEM slicing methods as tools to measure the thickness of nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Alloyeau, D., E-mail: alloyeau.damien@gmail.com [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); Laboratoire d' Etude des Microstructures - ONERA/CNRS, UMR 104, B.P. 72, 92322 Chatillon (France); Ricolleau, C. [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); Oikawa, T. [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); JEOL (Europe) SAS, Espace Claude Monet, 1 Allee de Giverny, 78290 Croissy-sur-Seine (France); Langlois, C. [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); Le Bouar, Y.; Loiseau, A. [Laboratoire d' Etude des Microstructures - ONERA/CNRS, UMR 104, B.P. 72, 92322 Chatillon (France)

2009-06-15

Nanoparticles' morphology is a key parameter in the understanding of their thermodynamical, optical, magnetic and catalytic properties. In general, nanoparticles, observed in transmission electron microscopy (TEM), are viewed in projection so that the determination of their thickness (along the projection direction) with respect to their projected lateral size is highly questionable. To date, the widely used methods to measure nanoparticles thickness in a transmission electron microscope are to use cross-section images or focal series in high-resolution transmission electron microscopy imaging (HRTEM 'slicing'). In this paper, we compare the focal series method with the electron tomography method to show that both techniques yield similar particle thickness in a range of size from 1 to 5 nm, but the electron tomography method provides better statistics since more particles can be analyzed at one time. For this purpose, we have compared, on the same samples, the nanoparticles thickness measurements obtained from focal series with the ones determined from cross-section profiles of tomograms (tomogram slicing) perpendicular to the plane of the substrate supporting the nanoparticles. The methodology is finally applied to the comparison of CoPt nanoparticles annealed ex situ at two different temperatures to illustrate the accuracy of the techniques in detecting small particle thickness changes.

A Three Step Explicit Method for Direct Solution of Third Order ...

African Journals Online (AJOL)

This study produces a three step discrete Linear Multistep Method for Direct solution of third order initial value problems of ordinary differential equations of the form y'''= f(x,y,y',y''). Taylor series expansion technique was adopted in the development of the method. The differential system from the basis polynomial function to ...

Direct fourier method reconstruction based on unequally spaced fast fourier transform

International Nuclear Information System (INIS)

Wu Xiaofeng; Zhao Ming; Liu Li

2003-01-01

First, We give an Unequally Spaced Fast Fourier Transform (USFFT) method, which is more exact and theoretically more comprehensible than its former counterpart. Then, with an interesting interpolation scheme, we discusse how to apply USFFT to Direct Fourier Method (DFM) reconstruction of parallel projection data. At last, an emulation experiment result is given. (authors)

Instrumental variable methods in comparative safety and effectiveness research.

Science.gov (United States)

Brookhart, M Alan; Rassen, Jeremy A; Schneeweiss, Sebastian

2010-06-01

Instrumental variable (IV) methods have been proposed as a potential approach to the common problem of uncontrolled confounding in comparative studies of medical interventions, but IV methods are unfamiliar to many researchers. The goal of this article is to provide a non-technical, practical introduction to IV methods for comparative safety and effectiveness research. We outline the principles and basic assumptions necessary for valid IV estimation, discuss how to interpret the results of an IV study, provide a review of instruments that have been used in comparative effectiveness research, and suggest some minimal reporting standards for an IV analysis. Finally, we offer our perspective of the role of IV estimation vis-à-vis more traditional approaches based on statistical modeling of the exposure or outcome. We anticipate that IV methods will be often underpowered for drug safety studies of very rare outcomes, but may be potentially useful in studies of intended effects where uncontrolled confounding may be substantial.

Instrumental variable methods in comparative safety and effectiveness research†

Science.gov (United States)

Brookhart, M. Alan; Rassen, Jeremy A.; Schneeweiss, Sebastian

2010-01-01

Summary Instrumental variable (IV) methods have been proposed as a potential approach to the common problem of uncontrolled confounding in comparative studies of medical interventions, but IV methods are unfamiliar to many researchers. The goal of this article is to provide a non-technical, practical introduction to IV methods for comparative safety and effectiveness research. We outline the principles and basic assumptions necessary for valid IV estimation, discuss how to interpret the results of an IV study, provide a review of instruments that have been used in comparative effectiveness research, and suggest some minimal reporting standards for an IV analysis. Finally, we offer our perspective of the role of IV estimation vis-à-vis more traditional approaches based on statistical modeling of the exposure or outcome. We anticipate that IV methods will be often underpowered for drug safety studies of very rare outcomes, but may be potentially useful in studies of intended effects where uncontrolled confounding may be substantial. PMID:20354968

Grid refinement for aeroacoustics in the lattice Boltzmann method: A directional splitting approach

Science.gov (United States)

Gendre, Félix; Ricot, Denis; Fritz, Guillaume; Sagaut, Pierre

2017-08-01

This study focuses on grid refinement techniques for the direct simulation of aeroacoustics, when using weakly compressible lattice Boltzmann models, such as the D3Q19 athermal velocity set. When it comes to direct noise computation, very small errors on the density or pressure field may have great negative consequences. Even strong acoustic density fluctuations have indeed a clearly lower amplitude than the hydrodynamic ones. This work deals with such very weak spurious fluctuations that emerge when a vortical structure crosses a refinement interface, which may contaminate the resulting aeroacoustic field. We show through an extensive literature review that, within the framework described above, this issue has never been addressed before. To tackle this problem, we develop an alternative algorithm and compare its behavior to a classical one, which fits our in-house vertex-centered data structure. Our main idea relies on a directional splitting of the continuous discrete velocity Boltzmann equation, followed by an integration over specific characteristics. This method can be seen as a specific coupling between finite difference and lattice Boltzmann, locally on the interface between the two grids. The method is assessed considering two cases: an acoustic pulse and a convected vortex. We show how very small errors on the density field arise and propagate throughout the domain when a vortical flow crosses the refinement interface. We also show that an increased free stream Mach number (but still within the weakly compressible regime) strongly deteriorates the situation, although the magnitude of the errors may remain negligible for purely aerodynamic studies. A drastically reduced level of error for the near-field spurious noise is obtained with our approach, especially for under-resolved simulations, a situation that is crucial for industrial applications. Thus, the vortex case is proved useful for aeroacoustic validations of any grid refinement algorithm.

Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products.

Science.gov (United States)

Chen, Yi; Pouillot, Régis; S Burall, Laurel; Strain, Errol A; Van Doren, Jane M; De Jesus, Antonio J; Laasri, Anna; Wang, Hua; Ali, Laila; Tatavarthy, Aparna; Zhang, Guodong; Hu, Lijun; Day, James; Sheth, Ishani; Kang, Jihun; Sahu, Surasri; Srinivasan, Devayani; Brown, Eric W; Parish, Mickey; Zink, Donald L; Datta, Atin R; Hammack, Thomas S; Macarisin, Dumitru

2017-01-16

A precise and accurate method for enumeration of low level of Listeria monocytogenes in foods is critical to a variety of studies. In this study, paired comparison of most probable number (MPN) and direct plating enumeration of L. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of L. monocytogenes. MPN was performed on all 1730 samples. Direct plating was performed on all samples using the RAPID'L.mono (RLM) agar (1600 samples) and agar Listeria Ottaviani and Agosti (ALOA; 130 samples). Probabilistic analysis with Bayesian inference model was used to compare paired direct plating and MPN estimates of L. monocytogenes in ice cream samples because assumptions implicit in ordinary least squares (OLS) linear regression analyses were not met for such a comparison. The probabilistic analysis revealed good agreement between the MPN and direct plating estimates, and this agreement showed that the MPN schemes and direct plating schemes using ALOA or RLM evaluated in the present study were suitable for enumerating low levels of L. monocytogenes in these ice cream samples. The statistical analysis further revealed that OLS linear regression analyses of direct plating and MPN data did introduce bias that incorrectly characterized systematic differences between estimates from the two methods. Published by Elsevier B.V.

Structural reliability calculation method based on the dual neural network and direct integration method.

Science.gov (United States)

Li, Haibin; He, Yun; Nie, Xiaobo

2018-01-01

Structural reliability analysis under uncertainty is paid wide attention by engineers and scholars due to reflecting the structural characteristics and the bearing actual situation. The direct integration method, started from the definition of reliability theory, is easy to be understood, but there are still mathematics difficulties in the calculation of multiple integrals. Therefore, a dual neural network method is proposed for calculating multiple integrals in this paper. Dual neural network consists of two neural networks. The neural network A is used to learn the integrand function, and the neural network B is used to simulate the original function. According to the derivative relationships between the network output and the network input, the neural network B is derived from the neural network A. On this basis, the performance function of normalization is employed in the proposed method to overcome the difficulty of multiple integrations and to improve the accuracy for reliability calculations. The comparisons between the proposed method and Monte Carlo simulation method, Hasofer-Lind method, the mean value first-order second moment method have demonstrated that the proposed method is an efficient and accurate reliability method for structural reliability problems.

Comparative analysis of enzyme-linked immunosorbent assay and direct microscopy for the diagnosis of Giardia intestinalis in fecal samples

Directory of Open Access Journals (Sweden)

Shipra Singhal

2015-01-01

Full Text Available Context: Giardiasis is one of the most common nonviral infections causing diarrheal illness worldwide. In this prospective cross-sectional study, we evaluated the RIDASCREEN ® Giardia kit for detection of Giardia intestinalis in stool samples and compared the results with direct microscopy. Materials and methods: A total of 360 fecal samples were collected. They were then processed by wet film, iodine preparation and an enzyme-linked immunosorbent assay (ELISA kit to determine the presence of Giardia trophozoites and cysts. Statistical analysis was performed by sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy. Results and Conclusion: Of the 360 cases, 17.2% samples were positive for Giardia by direct microscopy and 23.6% were found to be positive by ELISA (sensitivity ~97%, but specificity was ~92% only. Because of less specificity, we need to perform ELISA in congruence with direct microscopy, etc. Further studies need to be performed on a larger sample size using other molecular tests in order to get more accurate estimations.

Direct and regression methods do not give different estimates of digestible and metabolizable energy of wheat for pigs.

Science.gov (United States)

Bolarinwa, O A; Adeola, O

2012-12-01

Digestible and metabolizable energy contents of feed ingredients for pigs can be determined by direct or indirect methods. There are situations when only the indirect approach is suitable and the regression method is a robust indirect approach. This study was conducted to compare the direct and regression methods for determining the energy value of wheat for pigs. Twenty-four barrows with an average initial BW of 31 kg were assigned to 4 diets in a randomized complete block design. The 4 diets consisted of 969 g wheat/kg plus minerals and vitamins (sole wheat) for the direct method, corn (Zea mays)-soybean (Glycine max) meal reference diet (RD), RD + 300 g wheat/kg, and RD + 600 g wheat/kg. The 3 corn-soybean meal diets were used for the regression method and wheat replaced the energy-yielding ingredients, corn and soybean meal, so that the same ratio of corn and soybean meal across the experimental diets was maintained. The wheat used was analyzed to contain 883 g DM, 15.2 g N, and 3.94 Mcal GE/kg. Each diet was fed to 6 barrows in individual metabolism crates for a 5-d acclimation followed by a 5-d total but separate collection of feces and urine. The DE and ME for the sole wheat diet were 3.83 and 3.77 Mcal/kg DM, respectively. Because the sole wheat diet contained 969 g wheat/kg, these translate to 3.95 Mcal DE/kg DM and 3.89 Mcal ME/kg DM. The RD used for the regression approach yielded 4.00 Mcal DE and 3.91 Mcal ME/kg DM diet. Increasing levels of wheat in the RD linearly reduced (P direct method (3.95 and 3.89 Mcal/kg DM) did not differ (0.78 < P < 0.89) from those obtained using the regression method (3.96 and 3.88 Mcal/kg DM).

Pilot Signal Design and Direct Ranging Methods for Radio Localization Using OFDM Systems

DEFF Research Database (Denmark)

Jing, Lishuai

Having accurate localization capability is becoming important for existing and future terrestrial wireless communication systems, in particular for orthogonal frequency-division multiplexing (OFDM) systems, such as WiMAX, wireless local area network, long-term evolution (LTE) and its extension LTE......-Advanced. To obtain accurate position estimates, not only advanced estimation algorithms are needed but also the transmitted signals should be scrutinized. In this dissertation, we investigate how to design OFDM pilot signals and propose and evaluate high accuracy ranging techniques with tractable computational....... For scenarios where the number of path components is unknown and these components are not necessary separable, we propose a direct ranging technique using the received frequency-domain OFDM pilot signals. Compared to conventional (two-step) ranging methods, which estimate intermediate parameters...

Regression and direct methods do not give different estimates of digestible and metabolizable energy values of barley, sorghum, and wheat for pigs.

Science.gov (United States)

Bolarinwa, O A; Adeola, O

2016-02-01

Direct or indirect methods can be used to determine the DE and ME of feed ingredients for pigs. In situations when only the indirect approach is suitable, the regression method presents a robust indirect approach. Three experiments were conducted to compare the direct and regression methods for determining the DE and ME values of barley, sorghum, and wheat for pigs. In each experiment, 24 barrows with an average initial BW of 31, 32, and 33 kg were assigned to 4 diets in a randomized complete block design. The 4 diets consisted of 969 g barley, sorghum, or wheat/kg plus minerals and vitamins for the direct method; a corn-soybean meal reference diet (RD); the RD + 300 g barley, sorghum, or wheat/kg; and the RD + 600 g barley, sorghum, or wheat/kg. The 3 corn-soybean meal diets were used for the regression method. Each diet was fed to 6 barrows in individual metabolism crates for a 5-d acclimation followed by a 5-d period of total but separate collection of feces and urine in each experiment. Graded substitution of barley or wheat, but not sorghum, into the RD linearly reduced ( direct method-derived DE and ME for barley were 3,669 and 3,593 kcal/kg DM, respectively. The regressions of barley contribution to DE and ME in kilocalories against the quantity of barley DMI in kilograms generated 3,746 kcal DE/kg DM and 3,647 kcal ME/kg DM. The DE and ME for sorghum by the direct method were 4,097 and 4,042 kcal/kg DM, respectively; the corresponding regression-derived estimates were 4,145 and 4,066 kcal/kg DM. Using the direct method, energy values for wheat were 3,953 kcal DE/kg DM and 3,889 kcal ME/kg DM. The regressions of wheat contribution to DE and ME in kilocalories against the quantity of wheat DMI in kilograms generated 3,960 kcal DE/kg DM and 3,874 kcal ME/kg DM. The DE and ME of barley using the direct method were not different (0.3 direct method-derived DE and ME of sorghum were not different (0.5 direct method- and regression method-derived DE (3,953 and 3

A direct sampling method for inverse electromagnetic medium scattering

KAUST Repository

Ito, Kazufumi

2013-09-01

In this paper, we study the inverse electromagnetic medium scattering problem of estimating the support and shape of medium scatterers from scattered electric/magnetic near-field data. We shall develop a novel direct sampling method based on an analysis of electromagnetic scattering and the behavior of the fundamental solution. It is applicable to a few incident fields and needs only to compute inner products of the measured scattered field with the fundamental solutions located at sampling points. Hence, it is strictly direct, computationally very efficient and highly robust to the presence of data noise. Two- and three-dimensional numerical experiments indicate that it can provide reliable support estimates for multiple scatterers in the case of both exact and highly noisy data. © 2013 IOP Publishing Ltd.

Comparing models of rapidly rotating relativistic stars constructed by two numerical methods

Science.gov (United States)

Stergioulas, Nikolaos; Friedman, John L.

1995-05-01

We present the first direct comparison of codes based on two different numerical methods for constructing rapidly rotating relativistic stars. A code based on the Komatsu-Eriguchi-Hachisu (KEH) method (Komatsu et al. 1989), written by Stergioulas, is compared to the Butterworth-Ipser code (BI), as modified by Friedman, Ipser, & Parker. We compare models obtained by each method and evaluate the accuracy and efficiency of the two codes. The agreement is surprisingly good, and error bars in the published numbers for maximum frequencies based on BI are dominated not by the code inaccuracy but by the number of models used to approximate a continuous sequence of stars. The BI code is faster per iteration, and it converges more rapidly at low density, while KEH converges more rapidly at high density; KEH also converges in regions where BI does not, allowing one to compute some models unstable against collapse that are inaccessible to the BI code. A relatively large discrepancy recently reported (Eriguchi et al. 1994) for models based on Friedman-Pandharipande equation of state is found to arise from the use of two different versions of the equation of state. For two representative equations of state, the two-dimensional space of equilibrium configurations is displayed as a surface in a three-dimensional space of angular momentum, mass, and central density. We find, for a given equation of state, that equilibrium models with maximum values of mass, baryon mass, and angular momentum are (generically) either all unstable to collapse or are all stable. In the first case, the stable model with maximum angular velocity is also the model with maximum mass, baryon mass, and angular momentum. In the second case, the stable models with maximum values of these quantities are all distinct. Our implementation of the KEH method will be available as a public domain program for interested users.

A method for the direct numerical simulation of hypersonic boundary-layer instability with finite-rate chemistry

International Nuclear Information System (INIS)

Marxen, Olaf; Magin, Thierry E.; Shaqfeh, Eric S.G.; Iaccarino, Gianluca

2013-01-01

A new numerical method is presented here that allows to consider chemically reacting gases during the direct numerical simulation of a hypersonic fluid flow. The method comprises the direct coupling of a solver for the fluid mechanical model and a library providing the physio-chemical model. The numerical method for the fluid mechanical model integrates the compressible Navier–Stokes equations using an explicit time advancement scheme and high-order finite differences. This Navier–Stokes code can be applied to the investigation of laminar-turbulent transition and boundary-layer instability. The numerical method for the physio-chemical model provides thermodynamic and transport properties for different gases as well as chemical production rates, while here we exclusively consider a five species air mixture. The new method is verified for a number of test cases at Mach 10, including the one-dimensional high-temperature flow downstream of a normal shock, a hypersonic chemical reacting boundary layer in local thermodynamic equilibrium and a hypersonic reacting boundary layer with finite-rate chemistry. We are able to confirm that the diffusion flux plays an important role for a high-temperature boundary layer in local thermodynamic equilibrium. Moreover, we demonstrate that the flow for a case previously considered as a benchmark for the investigation of non-equilibrium chemistry can be regarded as frozen. Finally, the new method is applied to investigate the effect of finite-rate chemistry on boundary layer instability by considering the downstream evolution of a small-amplitude wave and comparing results with those obtained for a frozen gas as well as a gas in local thermodynamic equilibrium

A direct method of natural frequency analysis on pipeline conveying fluid with both ends supported

International Nuclear Information System (INIS)

Huang Yimin; Ge Seng; Wu Wei; Jie He

2012-01-01

Highlights: ► A direct method which derived from Ferrari's method was used to solve quartic equations. ► Frequency equations of pipeline conveying fluid with both ends supported was studied. ► Each order natural frequencies can be obtained by using the direct method. ► The first five critical flow velocities were obtained by using numerical method. - Abstract: The natural frequency equations of fluid–structure interaction in pipeline conveying fluid with both ends supported is investigated by a direct method, and the direct method is derived from Ferrari's method which is used to solve quartic equations. The dynamic equation of pipeline conveying fluid with two variables is obtained by Hamilton's variation principle based on Euler–Bernoulli Beam theory. By using the separation of variables method and the derived method from Ferrari's method, the natural frequency equations and the critical flow velocity equations of pipeline conveying fluid with both ends supported are obtained in mathematical decoupling. Each order natural frequencies and critical flow velocities can be obtained by using numerical method. The first five order dimensionless critical flow velocities are obtained, and the results indicate that clamped–simply supported is less stable than clamped–clamped supported and more stable than simply–simply supported. All the conclusions can be applied to nuclear installations and other engineering fields of improving the vibration.

Comparing simple root phenotyping methods on a core set of rice genotypes.

Science.gov (United States)

Shrestha, R; Al-Shugeairy, Z; Al-Ogaidi, F; Munasinghe, M; Radermacher, M; Vandenhirtz, J; Price, A H

2014-05-01

Interest in belowground plant growth is increasing, especially in relation to arguments that shallow-rooted cultivars are efficient at exploiting soil phosphorus while deep-rooted ones will access water at depth. However, methods for assessing roots in large numbers of plants are diverse and direct comparisons of methods are rare. Three methods for measuring root growth traits were evaluated for utility in discriminating rice cultivars: soil-filled rhizotrons, hydroponics and soil-filled pots whose bottom was sealed with a non-woven fabric (a potential method for assessing root penetration ability). A set of 38 rice genotypes including the OryzaSNP set of 20 cultivars, additional parents of mapping populations and products of marker-assisted selection for root QTLs were assessed. A novel method of image analysis for assessing rooting angles from rhizotron photographs was employed. The non-woven fabric was the easiest yet least discriminatory method, while the rhizotron was highly discriminatory and allowed the most traits to be measured but required more than three times the labour of the other methods. The hydroponics was both easy and discriminatory, allowed temporal measurements, but is most likely to suffer from artefacts. Image analysis of rhizotrons compared favourably to manual methods for discriminating between cultivars. Previous observations that cultivars from the indica subpopulation have shallower rooting angles than aus or japonica cultivars were confirmed in the rhizotrons, and indica and temperate japonicas had lower maximum root lengths in rhizotrons and hydroponics. It is concluded that rhizotrons are the preferred method for root screening, particularly since root angles can be assessed. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

On the computational efficiency of isogeometric methods for smooth elliptic problems using direct solvers

KAUST Repository

Collier, Nathan; Dalcin, Lisandro; Calo, Victor M.

2014-01-01

SUMMARY: We compare the computational efficiency of isogeometric Galerkin and collocation methods for partial differential equations in the asymptotic regime. We define a metric to identify when numerical experiments have reached this regime. We then apply these ideas to analyze the performance of different isogeometric discretizations, which encompass C0 finite element spaces and higher-continuous spaces. We derive convergence and cost estimates in terms of the total number of degrees of freedom and then perform an asymptotic numerical comparison of the efficiency of these methods applied to an elliptic problem. These estimates are derived assuming that the underlying solution is smooth, the full Gauss quadrature is used in each non-zero knot span and the numerical solution of the discrete system is found using a direct multi-frontal solver. We conclude that under the assumptions detailed in this paper, higher-continuous basis functions provide marginal benefits.

On the computational efficiency of isogeometric methods for smooth elliptic problems using direct solvers

KAUST Repository

Collier, Nathan

2014-09-17

SUMMARY: We compare the computational efficiency of isogeometric Galerkin and collocation methods for partial differential equations in the asymptotic regime. We define a metric to identify when numerical experiments have reached this regime. We then apply these ideas to analyze the performance of different isogeometric discretizations, which encompass C0 finite element spaces and higher-continuous spaces. We derive convergence and cost estimates in terms of the total number of degrees of freedom and then perform an asymptotic numerical comparison of the efficiency of these methods applied to an elliptic problem. These estimates are derived assuming that the underlying solution is smooth, the full Gauss quadrature is used in each non-zero knot span and the numerical solution of the discrete system is found using a direct multi-frontal solver. We conclude that under the assumptions detailed in this paper, higher-continuous basis functions provide marginal benefits.

Peritonitis related to percutaneous endoscopic gastrostomy using the direct method for cancer patients.

Science.gov (United States)

Osera, Shozo; Yano, Tomonori; Odagaki, Tomoyuki; Oono, Yasuhiro; Ikematsu, Hiroaki; Ohtsu, Atsushi; Kaneko, Kazuhiro

2015-10-01

Percutaneous endoscopic gastrostomy (PEG) using the direct method is generally indicated for cancer patients. However, there are little available data about peritonitis related to this method. The aim of this retrospective analysis was to assess peritonitis related to PEG using the direct method in patients with cancer. We assessed the prevalence of peritonitis and the relationship between peritonitis and patients' backgrounds, as well as the clinical course after peritonitis. Between December 2008 and December 2011, peritonitis was found in 9 (2.1 %) of 421 patients. Of the 9 patients with peritonitis, 4 had received PEG prior to chemoradiotherapy. Emergency surgical drainage was required in 1 patient, and the remaining 8 recovered with conservative treatment. Peritonitis occurred within 8 days of PEG for 8 of the 9 patients and occurred within 2 days of suture removal for 4 of the 9 patients. Peritonitis related to PEG using the direct method was less frequent for cancer patients. Peritonitis tended to occur within a few days after removal of securing suture and in patients with palliative stage.

Numerical Methods Application for Reinforced Concrete Elements-Theoretical Approach for Direct Stiffness Matrix Method

Directory of Open Access Journals (Sweden)

Sergiu Ciprian Catinas

2015-07-01

Full Text Available A detailed theoretical and practical investigation of the reinforced concrete elements is due to recent techniques and method that are implemented in the construction market. More over a theoretical study is a demand for a better and faster approach nowadays due to rapid development of the calculus technique. The paper above will present a study for implementing in a static calculus the direct stiffness matrix method in order capable to address phenomena related to different stages of loading, rapid change of cross section area and physical properties. The method is a demand due to the fact that in our days the FEM (Finite Element Method is the only alternative to such a calculus and FEM are considered as expensive methods from the time and calculus resources point of view. The main goal in such a method is to create the moment-curvature diagram in the cross section that is analyzed. The paper above will express some of the most important techniques and new ideas as well in order to create the moment curvature graphic in the cross sections considered.

Theory and analysis of accuracy for the method of characteristics direction probabilities with boundary averaging

International Nuclear Information System (INIS)

Liu, Zhouyu; Collins, Benjamin; Kochunas, Brendan; Downar, Thomas; Xu, Yunlin; Wu, Hongchun

2015-01-01

Highlights: • The CDP combines the benefits of the CPM’s efficiency and the MOC’s flexibility. • Boundary averaging reduces the computation effort with losing minor accuracy. • An analysis model is used to justify the choice of optimize averaging strategy. • Numerical results show the performance and accuracy. - Abstract: The method of characteristic direction probabilities (CDP) combines the benefits of the collision probability method (CPM) and the method of characteristics (MOC) for the solution of the integral form of the Botlzmann Transport Equation. By coupling only the fine regions traversed by the characteristic rays in a particular direction, the computational effort required to calculate the probability matrices and to solve the matrix system is considerably reduced compared to the CPM. Furthermore, boundary averaging is performed to reduce the storage and computation but the capability of dealing with complicated geometries is preserved since the same ray tracing information is used as in MOC. An analysis model for the outgoing angular flux is used to analyze a variety of outgoing angular flux averaging methods for the boundary and to justify the choice of optimize averaging strategy. The boundary average CDP method was then implemented in the Michigan PArallel Characteristic based Transport (MPACT) code to perform 2-D and 3-D transport calculations. The numerical results are given for different cases to show the effect of averaging on the outgoing angular flux, region scalar flux and the eigenvalue. Comparison of the results with the case with no averaging demonstrates that an angular dependent averaging strategy is possible for the CDP to improve its computational performance without compromising the achievable accuracy

The present state and future directions of PDF methods

Science.gov (United States)

Pope, S. B.

1992-01-01

The objectives of the workshop are presented in viewgraph format, as is this entire article. The objectives are to discuss the present status and the future direction of various levels of engineering turbulence modeling related to Computational Fluid Dynamics (CFD) computations for propulsion; to assure that combustion is an essential part of propulsion; and to discuss Probability Density Function (PDF) methods for turbulent combustion. Essential to the integration of turbulent combustion models is the development of turbulent model, chemical kinetics, and numerical method. Some turbulent combustion models typically used in industry are the k-epsilon turbulent model, the equilibrium/mixing limited combustion, and the finite volume codes.

Do infants fed directly from the breast have improved appetite regulation and slower growth during early childhood compared with infants fed from a bottle?

Directory of Open Access Journals (Sweden)

Fisher Jennifer O

2011-08-01

Full Text Available Abstract Background Behavioral mechanisms that contribute to the association between breastfeeding and reduced obesity risk are poorly understood. The purpose of this study was to evaluate the hypothesis that feeding human milk from the breast (direct breastfeeding has a more optimal association with subsequent child appetite regulation behaviors and growth, when compared to bottle-feeding. Methods Children (n = 109 aged 3- to 6- years were retrospectively classified as directly breastfed (fed exclusively at the breast, bottle-fed human milk, or bottle-fed formula in the first three months of life. Young children's appetite regulation was examined by measuring three constructs (satiety response, food responsiveness, enjoyment of food associated with obesity risk, using the Child Eating Behavior Questionnaire. Multinomial logistic regression analyses were used to test whether children bottle-fed either human milk or formula had reduced odds of high satiety and increased odds of high food responsiveness and high enjoyment of food compared to children fed directly from the breast. Current child weight status and growth trends from 6-36 months were also examined for their relation to direct breastfeeding and appetite regulation behaviors in early childhood. Results Children fed human milk in a bottle were 67% less likely to have high satiety responsiveness compared to directly breastfed children, after controlling for child age, child weight status, maternal race/ethnicity, and maternal education. There was no association of bottle-feeding (either human milk or formula with young children's food responsiveness and enjoyment of food. There was neither an association of direct breastfeeding with current child weight status, nor was there a clear difference between directly breastfed and bottle-fed children in growth trajectories from 6- to 36-months. More rapid infant changes in weight-for-age score were associated with lower satiety responsiveness

Comparative analysis of different methods for image enhancement

Institute of Scientific and Technical Information of China (English)

吴笑峰; 胡仕刚; 赵瑾; 李志明; 李劲; 唐志军; 席在芳

2014-01-01

Image enhancement technology plays a very important role to improve image quality in image processing. By enhancing some information and restraining other information selectively, it can improve image visual effect. The objective of this work is to implement the image enhancement to gray scale images using different techniques. After the fundamental methods of image enhancement processing are demonstrated, image enhancement algorithms based on space and frequency domains are systematically investigated and compared. The advantage and defect of the above-mentioned algorithms are analyzed. The algorithms of wavelet based image enhancement are also deduced and generalized. Wavelet transform modulus maxima (WTMM) is a method for detecting the fractal dimension of a signal, it is well used for image enhancement. The image techniques are compared by using the mean (μ), standard deviation (s), mean square error (MSE) and PSNR (peak signal to noise ratio). A group of experimental results demonstrate that the image enhancement algorithm based on wavelet transform is effective for image de-noising and enhancement. Wavelet transform modulus maxima method is one of the best methods for image enhancement.

Soil surface roughness: comparing old and new measuring methods and application in a soil erosion model

Science.gov (United States)

Thomsen, L. M.; Baartman, J. E. M.; Barneveld, R. J.; Starkloff, T.; Stolte, J.

2015-04-01

Quantification of soil roughness, i.e. the irregularities of the soil surface due to soil texture, aggregates, rock fragments and land management, is important as it affects surface storage, infiltration, overland flow, and ultimately sediment detachment and erosion. Roughness has been measured in the field using both contact methods (such as roller chain and pinboard) and sensor methods (such as stereophotogrammetry and terrestrial laser scanning (TLS)). A novel depth-sensing technique, originating in the gaming industry, has recently become available for earth sciences: the Xtion Pro method. Roughness data obtained using various methods are assumed to be similar; this assumption is tested in this study by comparing five different methods to measure roughness in the field on 1 m2 agricultural plots with different management (ploughing, harrowing, forest and direct seeding on stubble) in southern Norway. Subsequently, the values were used as input for the LISEM soil erosion model to test their effect on the simulated hydrograph at catchment scale. Results show that statistically significant differences between the methods were obtained only for the fields with direct seeding on stubble; for the other land management types the methods were in agreement. The spatial resolution of the contact methods was much lower than for the sensor methods (10 000 versus at least 57 000 points per square metre). In terms of costs and ease of use in the field, the Xtion Pro method is promising. Results from the LISEM model indicate that especially the roller chain overestimated the random roughness (RR) values and the model subsequently calculated less surface runoff than measured. In conclusion, the choice of measurement method for roughness data matters and depends on the required accuracy, resolution, mobility in the field and available budget. It is recommended to use only one method within one study.

Investigating the performance of directional boundary layer model through staged modeling method

Science.gov (United States)

Jeong, Moon-Gyu; Lee, Won-Chan; Yang, Seung-Hune; Jang, Sung-Hoon; Shim, Seong-Bo; Kim, Young-Chang; Suh, Chun-Suk; Choi, Seong-Woon; Kim, Young-Hee

2011-04-01

BLM since the feasibility of the BLM has been investigated in many papers[4][5][6]. Instead of fitting the parameters to the wafer critical dimensions (CD) directly, we tried to use the aerial image (AI) from the rigorous simulator with the electromagnetic field (EMF) solver. Usually that kind of method is known as the staged modeling method. To see the advantages of this method we conducted several experiments and observed the results comparing the method of fitting to the wafer CD directly. Through the tests we could observe some remarkable results and confirmed that the staged modeling had better performance in many ways.

An optimized method for the reconstruction of the direction of air showers for scintillator arrays

Energy Technology Data Exchange (ETDEWEB)

Krawczynski, H.; Prahl, J.; Arqueros, F.; Bradbury, S.; Cortina, J.; Deckers, T.; Eckmann, R.; Feigl, E.; Fernandez, J.; Fonseca, V.; Funk, B.; Gebauer, J.; Gonzalez, J.C.; Haustein, V.; Heinzelmann, G.; Holl, I.; Kirstein, O.; Kornmeyer, H.; Krennrich, F.; Lindner, A.; Lorenz, E.; Magnussen, N.; Martinez, S.; Merck, M.; Meyer, H.; Mirzoyan, R.; Moeller, H.; Moralejo, A.; Mueller, N.; Padilla, L.; Petry, D.; Plaga, R.; Prosch, C.; Rauterberg, G.; Rhode, W.; Samorski, M.; Sanchez, J.A.; Schmele, D.; Sooth, R.N.; Stamm, W.; Westerhoff, S.; Wiebel-Sooth, B.; Willmer, M. [Hamburg Univ. (Germany). 2. Inst. fuer Experimentalphys.]|[Universidad Complutense, Facultad de Ciencias Fisicas, Ciudad Universitaria, E-28040 Madrid (Spain)]|[Max Planck Institut fuer Physik, Foehringer Ring 6, D-80805 Muenchen (Germany)]|[Universitaet Kiel, Institut fuer Kernphysik, Olshausenstr. 40, D-24118 Kiel (Germany)]|[Universitaet Wuppertal, Fachbereich Physik, Gaussstr.20, D-42097 Wuppertal (Germany)

1996-12-11

An optimized method is presented for the reconstruction of air shower directions for scintillator arrays. The method takes into account that both the expectation value and the spread of the measured arrival times not only depend on the distance of a counter from the shower axis, but also on the number of particles registered in that counter. It also takes into account that the distributions of the measured arrival times are not Gaussian. For showers recorded with the HEGRA scintillator array above the threshold energy of E{sub thres}= 20 TeV the mean angular resolution obtained with this method is left angle {sigma}{sup {theta}}{sub 63%} right angle =1.0 {sup circle}, and above a threshold E{sub thres}= 50 TeV it is left angle {sigma}{sup {theta}}{sub 63%} right angle =0.6 {sup circle}. Comparing the new procedure with the HEGRA standard procedure the angular resolution has improved on average by a factor of 1.33. The mis-pointing has been determined with an accuracy of 0.15 {sup circle}. The method is developed using experimental data. (orig.).

An optimized method for the reconstruction of the direction of air showers for scintillator arrays

International Nuclear Information System (INIS)

Krawczynski, H.; Prahl, J.; Arqueros, F.; Bradbury, S.; Cortina, J.; Deckers, T.; Eckmann, R.; Feigl, E.; Fernandez, J.; Fonseca, V.; Funk, B.; Gebauer, J.; Gonzalez, J.C.; Haustein, V.; Heinzelmann, G.; Holl, I.; Kirstein, O.; Kornmeyer, H.; Krennrich, F.; Lindner, A.; Lorenz, E.; Magnussen, N.; Martinez, S.; Merck, M.; Meyer, H.; Mirzoyan, R.; Moeller, H.; Moralejo, A.; Mueller, N.; Padilla, L.; Petry, D.; Plaga, R.; Prosch, C.; Rauterberg, G.; Rhode, W.; Samorski, M.; Sanchez, J.A.; Schmele, D.; Sooth, R.N.; Stamm, W.; Westerhoff, S.; Wiebel-Sooth, B.; Willmer, M.

1996-01-01

An optimized method is presented for the reconstruction of air shower directions for scintillator arrays. The method takes into account that both the expectation value and the spread of the measured arrival times not only depend on the distance of a counter from the shower axis, but also on the number of particles registered in that counter. It also takes into account that the distributions of the measured arrival times are not Gaussian. For showers recorded with the HEGRA scintillator array above the threshold energy of E thres = 20 TeV the mean angular resolution obtained with this method is left angle σ θ 63% right angle =1.0 circle , and above a threshold E thres = 50 TeV it is left angle σ θ 63% right angle =0.6 circle . Comparing the new procedure with the HEGRA standard procedure the angular resolution has improved on average by a factor of 1.33. The mis-pointing has been determined with an accuracy of 0.15 circle . The method is developed using experimental data. (orig.)

Catalyst-Free Vapor-Phase Method for Direct Integration of Gas Sensing Nanostructures with Polymeric Transducing Platforms

Directory of Open Access Journals (Sweden)

Stella Vallejos

2014-01-01

Full Text Available Tungsten oxide nanoneedles (NNs are grown and integrated directly with polymeric transducing platforms for gas sensors via aerosol-assisted chemical vapor deposition (AACVD method. Material analysis shows the feasibility to grow highly crystalline nanomaterials in the form of NNs with aspect ratios between 80 and 200 and with high concentration of oxygen vacancies at the surface, whereas gas testing demonstrates moderate sensing responses to hydrogen at concentrations between 10 ppm and 50 ppm, which are comparable with results for tungsten oxide NNs grown on silicon transducing platforms. This method is demonstrated to be an attractive route to fabricate next generation of gas sensors devices, provided with flexibility and functionality, with great potential in a cost effective production for large-scale applications.

Frontal transcranial direct current stimulation (tDCS) abolishes list-method directed forgetting.

Science.gov (United States)

Silas, Jonathan; Brandt, Karen R

2016-03-11

It is a point of controversy as to whether directed forgetting effects are a result of active inhibition or a change of context initiated by the instruction to forget. In this study we test the causal role of active inhibition in directed forgetting. By applying cathodal transcranial direct current stimulation (tDCS) over the right prefrontal cortex we suppressed cortical activity commonly associated with inhibitory control. Participants who underwent real brain stimulation before completing the directed forgetting paradigm showed no directed forgetting effects. Conversely, those who underwent sham brain stimulation demonstrated classical directed forgetting effects. We argue that these findings suggest that inhibition is the primary mechanism that results in directed forgetting costs and benefits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

MALDI-TOF identification of Gram-negative bacteria directly from blood culture bottles containing charcoal: Sepsityper® kits versus centrifugation-filtration method.

Science.gov (United States)

Riederer, Kathleen; Cruz, Kristian; Shemes, Stephen; Szpunar, Susan; Fishbain, Joel T

2015-06-01

Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry has dramatically altered the way microbiology laboratories identify clinical isolates. Direct blood culture (BC) detection may be hampered, however, by the presence of charcoal in BC bottles currently in clinical use. This study evaluates an in-house process for extraction and MALDI-TOF identification of Gram-negative bacteria directly from BC bottles containing charcoal. Three hundred BC aliquots were extracted by a centrifugation-filtration method developed in our research laboratory with the first 96 samples processed in parallel using Sepsityper® kits. Controls were colonies from solid media with standard phenotypic and MALDI-TOF identification. The identification of Gram-negative bacteria was successful more often via the in-house method compared to Sepsityper® kits (94.7% versus 78.1%, P≤0.0001). Our in-house centrifugation-filtration method was further validated for isolation and identification of Gram-negative bacteria (95%; n=300) directly from BC bottles containing charcoal. Copyright © 2015 Elsevier Inc. All rights reserved.

A comparative study on effective dynamic modeling methods for flexible pipe

Energy Technology Data Exchange (ETDEWEB)

Lee, Chang Ho; Hong, Sup; Kim, Hyung Woo [Korea Research Institute of Ships and Ocean Engineering, Daejeon (Korea, Republic of); Kim, Sung Soo [Chungnam National University, Daejeon (Korea, Republic of)

2015-07-15

In this paper, in order to select a suitable method that is applicable to the large deflection with a small strain problem of pipe systems in the deep seabed mining system, the finite difference method with lumped mass from the field of cable dynamics and the substructure method from the field of flexible multibody dynamics were compared. Due to the difficulty of obtaining experimental results from an actual pipe system in the deep seabed mining system, a thin cantilever beam model with experimental results was employed for the comparative study. Accuracy of the methods was investigated by comparing the experimental results and simulation results from the cantilever beam model with different numbers of elements. Efficiency of the methods was also examined by comparing the operational counts required for solving equations of motion. Finally, this cantilever beam model with comparative study results can be promoted to be a benchmark problem for the flexible multibody dynamics.

Direct oxide reducing method

International Nuclear Information System (INIS)

Tokiwai, Moriyasu.

1995-01-01

Calcium oxides and magnetic oxides as wastes generated upon direct reduction are subjected to molten salt electrolysis, and reduced metallic calcium and magnesium are separated and recovered. Then calcium and magnesium are used recyclically as the reducing agent upon conducting direct oxide reduction. Even calcium oxides and magnesium oxides, which have high melting points and difficult to be melted usually, can be melted in molten salts of mixed fluorides or chlorides by molten-salt electrolysis. Oxides are decomposed by electrolysis, and oxygen is removed in the form of carbon monoxide, while the reduced metallic calcium and magnesium rise above the molten salts on the side of a cathode, and then separated. Since only carbon monoxide is generated as radioactive wastes upon molten salt electrolysis, the amount of radioactive wastes can be greatly reduced, and the amount of the reducing agent used can also be decreased remarkably. (N.H.)

A Comparative Evaluation of Methods for the Determination of ...

African Journals Online (AJOL)

Ultraviolet/Visible (UV/Vis) methods, a normal phase High Pressure Liquid Chromatographic (HPLC) method and a reverse phase HPLC method for vitamin A were compared and subsequently used to analyze samples of margarine, edible oil milk and milk drinks purchased from the Abule Egba and Oke Odo market in ...

Comparative analysis of minor histocompatibility antigens genotyping methods

Directory of Open Access Journals (Sweden)

A. S. Vdovin

2016-01-01

Full Text Available The wide range of techniques could be employed to find mismatches in minor histocompatibility antigens between transplant recipients and their donors. In the current study we compared three genotyping methods based on polymerase chain reaction (PCR for four minor antigens. Three of the tested methods: allele-specific PCR, restriction fragment length polymorphism and real-time PCR with TaqMan probes demonstrated 100% reliability when compared to Sanger sequencing for all of the studied polymorphisms. High resolution melting analysis was unsuitable for genotyping of one of the tested minor antigens (HA-1 as it has linked synonymous polymorphism. Obtained data could be used to select the strategy for large-scale clinical genotyping.

Stool frequency recording in severe acute malnutrition ('StoolSAM'); an agreement study comparing maternal recall versus direct observation using diapers.

Science.gov (United States)

Voskuijl, Wieger; Potani, Isabel; Bandsma, Robert; Baan, Anne; White, Sarah; Bourdon, Celine; Kerac, Marko

2017-06-07

Approximately 50% of the deaths of children under the age of 5 can be attributed to undernutrition, which also encompasses severe acute malnutrition (SAM). Diarrhoea is strongly associated with these deaths and is commonly diagnosed solely based on stool frequency and consistency obtained through maternal recall. This trial aims to determine whether this approach is equivalent to a 'directly observed method' in which a health care worker directly observed stool frequency using diapers in hospitalised children with complicated SAM. This study was conducted at 'Moyo' Nutritional Rehabilitation Unit, Queen Elizabeth Central Hospital, Malawi. Participants were children aged 5-59 months admitted with SAM. We compared 2 days of stool frequency data obtained with next-day maternal-recall versus a 'gold standard' in which a health care worker observed stool frequency every 2 h using diapers. After study completion, guardians were asked their preferred method and their level of education. We found poor agreement between maternal recall and the 'gold standard' of directly observed diapers. The sensitivity to detect diarrhoea based on maternal recall was poor, with only 75 and 56% of diarrhoea cases identified on days 1 and 2, respectively. However, the specificity was higher with more than 80% of children correctly classified as not having diarrhoea. On day 1, the mean stool frequency difference between the two methods was -0.17 (SD; 1.68) with limits of agreement (of stool frequency) of -3.55 and 3.20 and, similarly on day 2, the mean difference was -0.2 (SD; 1.59) with limits of agreement of -3.38 and 2.98. These limits extend beyond the pre-specified 'acceptable' limits of agreement (±1.5 stool per day) and indicate that the 2 methods are non-equivalent. The higher the stool frequency, the more discrepant the two methods were. Most primary care givers strongly preferred using diapers. This study shows lack of agreement between the assessment of stool frequency in SAM

Comparing methods for involving users in ideation

DEFF Research Database (Denmark)

Nicolajsen, Hanne Westh; Scupola, Ada; Sørensen, Flemming

2015-01-01

workshop method (involving users and employees) is especially good at qualifying and further developing ideas. The findings suggest that methods for involving users in ideation should be carefully selected and combined to achieve optimum benefits and avoid potential disadvantages.......In this paper we discuss how users may be involved in the ideation phase of innovation. The study compares the use of a blog and three future workshops (students, employees and a mix of the two) in a library. Our study shows that the blog is efficient in giving the users voice whereas the mixed...

Calculation of the energy provided by a PV generator. Comparative study: Conventional methods vs. artificial neural networks

International Nuclear Information System (INIS)

Almonacid, F.; Rus, C.; Perez-Higueras, P.; Hontoria, L.

2011-01-01

The use of photovoltaics for electricity generation purposes has recorded one of the largest increases in the field of renewable energies. The energy production of a grid-connected PV system depends on various factors. In a wide sense, it is considered that the annual energy provided by a generator is directly proportional to the annual radiation incident on the plane of the generator and to the installed nominal power. However, a range of factors is influencing the expected outcome by reducing the generation of energy. The aim of this study is to compare the results of four different methods for estimating the annual energy produced by a PV generator: three of them are classical methods and the fourth one is based on an artificial neural network developed by the R and D Group for Solar and Automatic Energy at the University of Jaen. The results obtained shown that the method based on an artificial neural network provides better results than the alternative classical methods in study, mainly due to the fact that this method takes also into account some second order effects, such as low irradiance, angular and spectral effects. -- Research highlights: → It is considered that the annual energy provided by a PV generator is directly proportional to the annual radiation incident on the plane of the generator and to the installed nominal power. → A range of factors are influencing the expected outcome by reducing the generation of energy (mismatch losses, dirt and dust, Ohmic losses,.). → The aim of this study is to compare the results of four different methods for estimating the annual energy produced by a PV generator: three of them are classical methods and the fourth one is based on an artificial neural network. → The results obtained shown that the method based on an artificial neural network provides better results than the alternative classical methods in study. While classical methods have only taken into account temperature losses, the method based in

Finding Direction in the Search for Selection.

Science.gov (United States)

Thiltgen, Grant; Dos Reis, Mario; Goldstein, Richard A

2017-01-01

Tests for positive selection have mostly been developed to look for diversifying selection where change away from the current amino acid is often favorable. However, in many cases we are interested in directional selection where there is a shift toward specific amino acids, resulting in increased fitness in the species. Recently, a few methods have been developed to detect and characterize directional selection on a molecular level. Using the results of evolutionary simulations as well as HIV drug resistance data as models of directional selection, we compare two such methods with each other, as well as against a standard method for detecting diversifying selection. We find that the method to detect diversifying selection also detects directional selection under certain conditions. One method developed for detecting directional selection is powerful and accurate for a wide range of conditions, while the other can generate an excessive number of false positives.

Comparative Analysis for Robust Penalized Spline Smoothing Methods

Directory of Open Access Journals (Sweden)

Bin Wang

2014-01-01

Full Text Available Smoothing noisy data is commonly encountered in engineering domain, and currently robust penalized regression spline models are perceived to be the most promising methods for coping with this issue, due to their flexibilities in capturing the nonlinear trends in the data and effectively alleviating the disturbance from the outliers. Against such a background, this paper conducts a thoroughly comparative analysis of two popular robust smoothing techniques, the M-type estimator and S-estimation for penalized regression splines, both of which are reelaborated starting from their origins, with their derivation process reformulated and the corresponding algorithms reorganized under a unified framework. Performances of these two estimators are thoroughly evaluated from the aspects of fitting accuracy, robustness, and execution time upon the MATLAB platform. Elaborately comparative experiments demonstrate that robust penalized spline smoothing methods possess the capability of resistance to the noise effect compared with the nonrobust penalized LS spline regression method. Furthermore, the M-estimator exerts stable performance only for the observations with moderate perturbation error, whereas the S-estimator behaves fairly well even for heavily contaminated observations, but consuming more execution time. These findings can be served as guidance to the selection of appropriate approach for smoothing the noisy data.

Consensus of recommendations guiding comparative effectiveness research methods.

Science.gov (United States)

Morton, Jacob B; McConeghy, Robert; Heinrich, Kirstin; Gatto, Nicolle M; Caffrey, Aisling R

2016-12-01

Because of an increasing demand for quality comparative effectiveness research (CER), methods guidance documents have been published, such as those from the Agency for Healthcare Research and Quality (AHRQ) and the Patient-Centered Outcomes Research Institute (PCORI). Our objective was to identify CER methods guidance documents and compare them to produce a summary of important recommendations which could serve as a consensus of CER method recommendations. We conducted a systematic literature review to identify CER methods guidance documents published through 2014. Identified documents were analyzed for methods guidance recommendations. Individual recommendations were categorized to determine the degree of overlap. We identified nine methods guidance documents, which contained a total of 312 recommendations, 97% of which were present in two or more documents. All nine documents recommended transparency and adaptation for relevant stakeholders in the interpretation and dissemination of results. Other frequently shared CER methods recommendations included: study design and operational definitions should be developed a priori and allow for replication (n = 8 documents); focus on areas with gaps in current clinical knowledge that are relevant to decision-makers (n = 7); validity of measures, instruments, and data should be assessed and discussed (n = 7); outcomes, including benefits and harms, should be clinically meaningful, and objectively measured (n = 7). Assessment for and strategies to minimize bias (n = 6 documents), confounding (n = 6), and heterogeneity (n = 4) were also commonly shared recommendations between documents. We offer a field-consensus guide based on nine CER methods guidance documents that will aid researchers in designing CER studies and applying CER methods. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Simple method for direct crown base height estimation of individual conifer trees using airborne LiDAR data.

Science.gov (United States)

Luo, Laiping; Zhai, Qiuping; Su, Yanjun; Ma, Qin; Kelly, Maggi; Guo, Qinghua

2018-05-14

Crown base height (CBH) is an essential tree biophysical parameter for many applications in forest management, forest fuel treatment, wildfire modeling, ecosystem modeling and global climate change studies. Accurate and automatic estimation of CBH for individual trees is still a challenging task. Airborne light detection and ranging (LiDAR) provides reliable and promising data for estimating CBH. Various methods have been developed to calculate CBH indirectly using regression-based means from airborne LiDAR data and field measurements. However, little attention has been paid to directly calculate CBH at the individual tree scale in mixed-species forests without field measurements. In this study, we propose a new method for directly estimating individual-tree CBH from airborne LiDAR data. Our method involves two main strategies: 1) removing noise and understory vegetation for each tree; and 2) estimating CBH by generating percentile ranking profile for each tree and using a spline curve to identify its inflection points. These two strategies lend our method the advantages of no requirement of field measurements and being efficient and effective in mixed-species forests. The proposed method was applied to a mixed conifer forest in the Sierra Nevada, California and was validated by field measurements. The results showed that our method can directly estimate CBH at individual tree level with a root-mean-squared error of 1.62 m, a coefficient of determination of 0.88 and a relative bias of 3.36%. Furthermore, we systematically analyzed the accuracies among different height groups and tree species by comparing with field measurements. Our results implied that taller trees had relatively higher uncertainties than shorter trees. Our findings also show that the accuracy for CBH estimation was the highest for black oak trees, with an RMSE of 0.52 m. The conifer species results were also good with uniformly high R 2 ranging from 0.82 to 0.93. In general, our method has

Sensitivity study with respect to direction of ADI method during re-flooding in AHWR

Energy Technology Data Exchange (ETDEWEB)

Kumar, M.; Mukhopadhyay, D. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Safety Div.; Ghosh, A.K. [Bhabha Atomic Research Centre, Mumbai (India). Raja Ramanna Fellow; Kumar, R. [Indian Institute of Technology, Roorkee (India)

2015-05-15

The Advanced Heavy water Reactor (AHWR) is a natural circulation vertical pressure tube type boiling light water cooled and heavy water moderated reactor. As the AHWR fuel bundle quenching under accident condition is designed primarily with radial jets at several axial locations, bottom re-flooding still remain open as another option. Radial direction injection of emergency core cooling leads to rewetting of AHWR fuel cluster in circumferential direction. A 3D fuel pin model has been developed by using Finite Difference Method (FDM) of transient heat conduction equation. Alternating Direction Implicit technique of Finite Difference Method (FDM) has been used for discretisation of numerical equation in different time step at different direction. Sensitivity numerical study with respect to direction of ADI method has been carried out to optimize the time step during the transient as well as steady state and is found that it is insensitivity with direction of solution. Further, to assess influence of circumferential rewetting vis-a-vis axial rewetting. Both the analyses are carried out with same fluid temperature and heat transfer coefficients as boundary conditions. It has been found from the analyses that for radial jet, the circumferential conduction is significant and overall the fuel temperature falls in the quench plane with the initiation of quenching event. The paper discusses the sensitivity study with respect to direction of ADI solution and comparison of numerical results for circumferential and axial rewetting for single pin.

Direct Survival Analysis: a new stock assessment method

Directory of Open Access Journals (Sweden)

Eduardo Ferrandis

2007-03-01

Full Text Available In this work, a new stock assessment method, Direct Survival Analysis, is proposed and described. The parameter estimation of the Weibull survival model proposed by Ferrandis (2007 is obtained using trawl survey data. This estimation is used to establish a baseline survival function, which is in turn used to estimate the specific survival functions in the different cohorts considered through an adaptation of the separable model of the fishing mortality rates introduced by Pope and Shepherd (1982. It is thus possible to test hypotheses on the evolution of survival during the period studied and to identify trends in recruitment. A link is established between the preceding analysis of trawl survey data and the commercial catch-at-age data that are generally obtained to evaluate the population using analytical models. The estimated baseline survival, with the proposed versions of the stock and catch equations and the adaptation of the Separable Model, may be applied to commercial catch-at-age data. This makes it possible to estimate the survival corresponding to the landing data, the initial size of the cohort and finally, an effective age of first capture, in order to complete the parameter model estimation and consequently the estimation of the whole survival and mortality, along with the reference parameters that are useful for management purposes. Alternatively, this estimation of an effective age of first capture may be obtained by adapting the demographic structure of trawl survey data to that of the commercial fleet through suitable selectivity models of the commercial gears. The complete model provides the evaluation of the stock at any age. The coherence (and hence the mutual “calibration” between the two kinds of information may be analysed and compared with results obtained by other methods, such as virtual population analysis (VPA, in order to improve the diagnosis of the state of exploitation of the population. The model may be

Direct diode lasers with comparable beam quality to fiber, CO2, and solid state lasers

Science.gov (United States)

Huang, Robin K.; Chann, Bien; Burgess, James; Kaiman, Michael; Overman, Robert; Glenn, John D.; Tayebati, Parviz

2012-03-01

TeraDiode has produced kW-class ultra-high brightness fiber-coupled direct diode lasers. A fiber-coupled direct diode laser with a power level of 2,040 W from a 50 μm core diameter, 0.15 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. This was achieved with a novel beam combining and shaping technique using COTS diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 3.75 mm-mrad and is the lowest BPP kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 2-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers.

Direct Calculation of Permeability by High-Accurate Finite Difference and Numerical Integration Methods

KAUST Repository

Wang, Yi

2016-07-21

Velocity of fluid flow in underground porous media is 6~12 orders of magnitudes lower than that in pipelines. If numerical errors are not carefully controlled in this kind of simulations, high distortion of the final results may occur [1-4]. To fit the high accuracy demands of fluid flow simulations in porous media, traditional finite difference methods and numerical integration methods are discussed and corresponding high-accurate methods are developed. When applied to the direct calculation of full-tensor permeability for underground flow, the high-accurate finite difference method is confirmed to have numerical error as low as 10-5% while the high-accurate numerical integration method has numerical error around 0%. Thus, the approach combining the high-accurate finite difference and numerical integration methods is a reliable way to efficiently determine the characteristics of general full-tensor permeability such as maximum and minimum permeability components, principal direction and anisotropic ratio. Copyright © Global-Science Press 2016.

Electrical Versus Optical: Comparing Methods for Detecting Terahertz Radiation Using Neon Lamps

Science.gov (United States)

Slocombe, L. L.; Lewis, R. A.

2018-05-01

Terahertz radiation impinging on a lit neon tube causes additional ionization of the encapsulated gas. As a result, the electrical current flowing between the electrodes increases and the glow discharge in the tube brightens. These dual phenomena suggest two distinct modes of terahertz sensing. The electrical mode simply involves measuring the electrical current. The optical mode involves monitoring the brightness of the weakly ionized plasma glow discharge. Here, we directly compare the two detection modes under identical experimental conditions. We measure 0.1-THz radiation modulated at frequencies in the range 0.1-10 kHz, for lamp currents in the range 1-10 mA. We find that electrical detection provides a superior signal-to-noise ratio while optical detection has a faster response. Either method serves as the basis of a compact, robust, and inexpensive room-temperature detector of terahertz radiation.

A robust direct-integration method for rotorcraft maneuver and periodic response

Science.gov (United States)

Panda, Brahmananda

1992-01-01

The Newmark-Beta method and the Newton-Raphson iteration scheme are combined to develop a direct-integration method for evaluating the maneuver and periodic-response expressions for rotorcraft. The method requires the generation of Jacobians and includes higher derivatives in the formulation of the geometric stiffness matrix to enhance the convergence of the system. The method leads to effective convergence with nonlinear structural dynamics and aerodynamic terms. Singularities in the matrices can be addressed with the method as they arise from a Lagrange multiplier approach for coupling equations with nonlinear constraints. The method is also shown to be general enough to handle singularities from quasisteady control-system models. The method is shown to be more general and robust than the similar 2GCHAS method for analyzing rotorcraft dynamics.

Comparative study on the welded structure fatigue strength assessment method

Science.gov (United States)

Hu, Tao

2018-04-01

Due to the welding structure is widely applied in various industries, especially the pressure container, motorcycle, automobile, aviation, ship industry, such as large crane steel structure, so for welded structure fatigue strength evaluation is particularly important. For welded structure fatigue strength evaluation method mainly has four kinds of, the more from the use of two kinds of welded structure fatigue strength evaluation method, namely the nominal stress method and the hot spot stress evaluation method, comparing from its principle, calculation method for the process analysis and research, compare the similarities and the advantages and disadvantages, the analysis of practical engineering problems to provide the reference for every profession and trade, as well as the future welded structure fatigue strength and life evaluation method put forward outlook.

NEW COMPLETENESS METHODS FOR ESTIMATING EXOPLANET DISCOVERIES BY DIRECT DETECTION

International Nuclear Information System (INIS)

Brown, Robert A.; Soummer, Remi

2010-01-01

We report on new methods for evaluating realistic observing programs that search stars for planets by direct imaging, where observations are selected from an optimized star list and stars can be observed multiple times. We show how these methods bring critical insight into the design of the mission and its instruments. These methods provide an estimate of the outcome of the observing program: the probability distribution of discoveries (detection and/or characterization) and an estimate of the occurrence rate of planets (η). We show that these parameters can be accurately estimated from a single mission simulation, without the need for a complete Monte Carlo mission simulation, and we prove the accuracy of this new approach. Our methods provide tools to define a mission for a particular science goal; for example, a mission can be defined by the expected number of discoveries and its confidence level. We detail how an optimized star list can be built and how successive observations can be selected. Our approach also provides other critical mission attributes, such as the number of stars expected to be searched and the probability of zero discoveries. Because these attributes depend strongly on the mission scale (telescope diameter, observing capabilities and constraints, mission lifetime, etc.), our methods are directly applicable to the design of such future missions and provide guidance to the mission and instrument design based on scientific performance. We illustrate our new methods with practical calculations and exploratory design reference missions for the James Webb Space Telescope (JWST) operating with a distant starshade to reduce scattered and diffracted starlight on the focal plane. We estimate that five habitable Earth-mass planets would be discovered and characterized with spectroscopy, with a probability of zero discoveries of 0.004, assuming a small fraction of JWST observing time (7%), η = 0.3, and 70 observing visits, limited by starshade fuel.

Direct and indirect radioiodination of protein: comparative study of chemotactic peptide labeling; Radioiodacao de proteina por via direta e indireta: estudo comparativo da marcacao de peptideo quimiotatico

Energy Technology Data Exchange (ETDEWEB)

Lavinas, Tatiana

2004-07-01

The development of simple methods for protein radioiodination have stimulated the use of radioiodinated peptides in vivo. There are two basic methods for labeling proteins with radioiodine: direct labeling, reaction of an electrophilic radioiodine with functional activated groups on protein, like the phenol ring in the tyrosine residue, and the conjugation of a previously radioiodinated molecule to the protein, referred as indirect method. The great problem related to the direct radioiodination of proteins is the in vivo dehalogenation. This problem can be minimized if a non-phenolic prosthetic group is used in the indirect radioiodination of the peptide. The ATE prosthetic group, N-succinimidyl 3-(tri-n-butylstannyl) benzoate, when radioiodinated by electrophilic iododestannilation produces N-succinimidyl 3-[{sup 123}l/{sup 131}l] iodine benzoate (SIB) that is subsequently conjugated to the protein by the acylation of the lysine group. There are many radiopharmaceuticals employed in scintigraphic images of infection and inflammation used with some limitations. These limitations stimulated the improvement of a new class of radiopharmaceuticals, the receptor-specific related labeled peptides, as the mediators of the inflammatory response, that presents high affinity by receptors expressed in the inflammation process, and fast clearance from blood and non-target tissues. One of these molecules is the synthetic chemotactic peptide fNleLFNIeYK that presents potent chemotaxis for leukocytes, with high affinity by the receptors presented in polymorphonuclear leukocytes and mononuclear phagocytes. The objective of this work included the synthesis of ATE prosthetic group and comparative radioiodination of the chemotactic peptide fNleLFNIeYK by direct and indirect methods, with radiochemical purity determination and evaluation of in vivo and in vitro stability of the compounds. This work presented an original contribution in the comparative biological distribution studies

THE MASS-METALLICITY RELATION WITH THE DIRECT METHOD ON STACKED SPECTRA OF SDSS GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Andrews, Brett H.; Martini, Paul, E-mail: andrews@astronomy.ohio-state.edu [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

2013-03-10

The relation between galaxy stellar mass and gas-phase metallicity is a sensitive diagnostic of the main processes that drive galaxy evolution, namely cosmological gas inflow, metal production in stars, and gas outflow via galactic winds. We employed the direct method to measure the metallicities of {approx}200,000 star-forming galaxies from the Sloan Digital Sky Survey that were stacked in bins of (1) stellar mass and (2) both stellar mass and star formation rate (SFR) to significantly enhance the signal-to-noise ratio of the weak [O III] {lambda}4363 and [O II] {lambda}{lambda}7320, 7330 auroral lines required to apply the direct method. These metallicity measurements span three decades in stellar mass from log(M{sub *}/M{sub Sun }) = 7.4-10.5, which allows the direct method mass-metallicity relation to simultaneously capture the high-mass turnover and extend a full decade lower in mass than previous studies that employed more uncertain strong line methods. The direct method mass-metallicity relation rises steeply at low mass (O/H {proportional_to} M{sub *} {sup 1/2}) until it turns over at log(M{sub *}/M{sub Sun }) = 8.9 and asymptotes to 12 + log(O/H) = 8.8 at high mass. The direct method mass-metallicity relation has a steeper slope, a lower turnover mass, and a factor of two to three greater dependence on SFR than strong line mass-metallicity relations. Furthermore, the SFR-dependence appears monotonic with stellar mass, unlike strong line mass-metallicity relations. We also measure the N/O abundance ratio, an important tracer of star formation history, and find the clear signature of primary and secondary nitrogen enrichment. N/O correlates tightly with oxygen abundance, and even more so with stellar mass.

Evaluation of methods used for the direct generation of response spectra

International Nuclear Information System (INIS)

Mayers, R.L.; Muraki, T.; Jones, L.R.; Donikian, R.

1983-01-01

The paper presents an alternate methodology by which seismic in-structure response spectra may be generated directly from either ground or floor excitation spectra. The method is based upon stochastic concepts and utilizes the modal superposition solution. The philosophy of the method is based upon the notion that the evaluation of 'peak' response in uncertain excitation environments is only meaningful in a probabilistic sense. This interpretation of response spectra facilitates the generation of in-structure spectra for any non-exceedance probability (NEP). The method is validated by comparisons with a set of deterministic time-history analyses with three example models: an eleven-story building model, a containment structure stick model, and a floor mounted control panel, subjected to ten input spectrum compatible acceleration time-histories. A significant finding resulting from these examples is that the time-history method portrayed substantial variation in the resulting in-structure spectra, and therefore is unreliable for the generation of spectra. It is shown that the average of the time-history generated spectra can be estimated by the direct generation procedure, and reliable spectra may be generated for 85 NEP levels. The methodology presented herein is shown to be valid for both primary and secondary systems. Also included in the paper, is a review of the stochastic methods proposed by Singh and Der Kiureghian et. al., and the Fourier transform method proposed by Scanlan et al. (orig./HP)

Direct method gas-phase oxygen abundances of four Lyman break analogs

Energy Technology Data Exchange (ETDEWEB)

Brown, Jonathan S.; Croxall, Kevin V.; Pogge, Richard W. [Department of Astronomy, The Ohio State University, Columbus, OH 43201 (United States)

2014-09-10

We measure the gas-phase oxygen abundances in four Lyman break analogs using auroral emission lines to derive direct abundances. The direct method oxygen abundances of these objects are generally consistent with the empirically derived strong-line method values, confirming that these objects are low oxygen abundance outliers from the mass-metallicity (MZ) relation defined by star forming Sloan Digital Sky Survey galaxies. We find slightly anomalous excitation conditions (Wolf-Rayet features) that could potentially bias the empirical estimates toward high values if caution is not exercised in the selection of the strong-line calibration. The high rate of star formation and low oxygen abundance of these objects is consistent with the predictions of the fundamental metallicity relation, in which the infall of relatively unenriched gas simultaneously triggers an episode of star formation and dilutes the interstellar medium of the host galaxy.

Comparability of river suspended-sediment sampling and laboratory analysis methods

Science.gov (United States)

Groten, Joel T.; Johnson, Gregory D.

2018-03-06

Accurate measurements of suspended sediment, a leading water-quality impairment in many Minnesota rivers, are important for managing and protecting water resources; however, water-quality standards for suspended sediment in Minnesota are based on grab field sampling and total suspended solids (TSS) laboratory analysis methods that have underrepresented concentrations of suspended sediment in rivers compared to U.S. Geological Survey equal-width-increment or equal-discharge-increment (EWDI) field sampling and suspended sediment concentration (SSC) laboratory analysis methods. Because of this underrepresentation, the U.S. Geological Survey, in collaboration with the Minnesota Pollution Control Agency, collected concurrent grab and EWDI samples at eight sites to compare results obtained using different combinations of field sampling and laboratory analysis methods.Study results determined that grab field sampling and TSS laboratory analysis results were biased substantially low compared to EWDI sampling and SSC laboratory analysis results, respectively. Differences in both field sampling and laboratory analysis methods caused grab and TSS methods to be biased substantially low. The difference in laboratory analysis methods was slightly greater than field sampling methods.Sand-sized particles had a strong effect on the comparability of the field sampling and laboratory analysis methods. These results indicated that grab field sampling and TSS laboratory analysis methods fail to capture most of the sand being transported by the stream. The results indicate there is less of a difference among samples collected with grab field sampling and analyzed for TSS and concentration of fines in SSC. Even though differences are present, the presence of strong correlations between SSC and TSS concentrations provides the opportunity to develop site specific relations to address transport processes not captured by grab field sampling and TSS laboratory analysis methods.

Alignment methods: strategies, challenges, benchmarking, and comparative overview.

Science.gov (United States)

Löytynoja, Ari

2012-01-01

Comparative evolutionary analyses of molecular sequences are solely based on the identities and differences detected between homologous characters. Errors in this homology statement, that is errors in the alignment of the sequences, are likely to lead to errors in the downstream analyses. Sequence alignment and phylogenetic inference are tightly connected and many popular alignment programs use the phylogeny to divide the alignment problem into smaller tasks. They then neglect the phylogenetic tree, however, and produce alignments that are not evolutionarily meaningful. The use of phylogeny-aware methods reduces the error but the resulting alignments, with evolutionarily correct representation of homology, can challenge the existing practices and methods for viewing and visualising the sequences. The inter-dependency of alignment and phylogeny can be resolved by joint estimation of the two; methods based on statistical models allow for inferring the alignment parameters from the data and correctly take into account the uncertainty of the solution but remain computationally challenging. Widely used alignment methods are based on heuristic algorithms and unlikely to find globally optimal solutions. The whole concept of one correct alignment for the sequences is questionable, however, as there typically exist vast numbers of alternative, roughly equally good alignments that should also be considered. This uncertainty is hidden by many popular alignment programs and is rarely correctly taken into account in the downstream analyses. The quest for finding and improving the alignment solution is complicated by the lack of suitable measures of alignment goodness. The difficulty of comparing alternative solutions also affects benchmarks of alignment methods and the results strongly depend on the measure used. As the effects of alignment error cannot be predicted, comparing the alignments' performance in downstream analyses is recommended.

Direction-dependent waist-shift-difference of Gaussian beam in a multiple-pass zigzag slab amplifier and geometrical optics compensation method.

Science.gov (United States)

Li, Zhaoyang; Kurita, Takashi; Miyanaga, Noriaki

2017-10-20

Zigzag and non-zigzag beam waist shifts in a multiple-pass zigzag slab amplifier are investigated based on the propagation of a Gaussian beam. Different incident angles in the zigzag and non-zigzag planes would introduce a direction-dependent waist-shift-difference, which distorts the beam quality in both the near- and far-fields. The theoretical model and analytical expressions of this phenomenon are presented, and intensity distributions in the two orthogonal planes are simulated and compared. A geometrical optics compensation method by a beam with 90° rotation is proposed, which not only could correct the direction-dependent waist-shift-difference but also possibly average the traditional thermally induced wavefront-distortion-difference between the horizontal and vertical beam directions.

Cycle-Based Cluster Variational Method for Direct and Inverse Inference

Science.gov (United States)

Furtlehner, Cyril; Decelle, Aurélien

2016-08-01

Large scale inference problems of practical interest can often be addressed with help of Markov random fields. This requires to solve in principle two related problems: the first one is to find offline the parameters of the MRF from empirical data (inverse problem); the second one (direct problem) is to set up the inference algorithm to make it as precise, robust and efficient as possible. In this work we address both the direct and inverse problem with mean-field methods of statistical physics, going beyond the Bethe approximation and associated belief propagation algorithm. We elaborate on the idea that loop corrections to belief propagation can be dealt with in a systematic way on pairwise Markov random fields, by using the elements of a cycle basis to define regions in a generalized belief propagation setting. For the direct problem, the region graph is specified in such a way as to avoid feed-back loops as much as possible by selecting a minimal cycle basis. Following this line we are led to propose a two-level algorithm, where a belief propagation algorithm is run alternatively at the level of each cycle and at the inter-region level. Next we observe that the inverse problem can be addressed region by region independently, with one small inverse problem per region to be solved. It turns out that each elementary inverse problem on the loop geometry can be solved efficiently. In particular in the random Ising context we propose two complementary methods based respectively on fixed point equations and on a one-parameter log likelihood function minimization. Numerical experiments confirm the effectiveness of this approach both for the direct and inverse MRF inference. Heterogeneous problems of size up to 10^5 are addressed in a reasonable computational time, notably with better convergence properties than ordinary belief propagation.

Burn-up determination of irradiated uranium oxide by means of direct gama spectrometry and by radiochemical method

International Nuclear Information System (INIS)

Cunha, I.I.L.; Nastasi, M.J.C.; Lima, F.W.

1981-09-01

The burn-up of thermal neutrons irradiated U 3 O 8 (natural uranium) samples has been determined by using both direct gamma spectrometry and radiochemical methods and the results obtained were compared. The fission products 144 Ce, 103 Ru, 106 Ru, 137 Cs and 95 Zr were chosen as burn-up monitors. In order to isolate the radioisotopes chosen as monitors, a radiochemical separation procedure has been established, in which the solvent extraction technique was used to separate cerium, cesium and ruthenium one from the other and all of them from uranium. The separation between zirconium and niobium and of both elements from the other radioisotopes and uranium was accomplished by means of adsorption on a silica-gel column, followed by selective elution of zirconium and of niobium. When use was made of the direct gamma-ray spectrometry method, the radioactivity of each nuclide of interest was measured in presence of all others. For this purpose use was made of gamma-ray spectrometry and of a Ge-Li detector. Comparison of burn-up values obtained by both methods was made by means of Student's 't' test, and this showed that results obtained in each case are statistically equal. (Author) [pt

Directional Total Generalized Variation Regularization for Impulse Noise Removal

DEFF Research Database (Denmark)

Kongskov, Rasmus Dalgas; Dong, Yiqiu

2017-01-01

this regularizer for directional images is highly advantageous. In order to estimate directions in impulse noise corrupted images, which is much more challenging compared to Gaussian noise corrupted images, we introduce a new Fourier transform-based method. Numerical experiments show that this method is more...

Methods of international health technology assessment agencies for economic evaluations--a comparative analysis.

Science.gov (United States)

Mathes, Tim; Jacobs, Esther; Morfeld, Jana-Carina; Pieper, Dawid

2013-09-30

The number of Health Technology Assessment (HTA) agencies increases. One component of HTAs are economic aspects. To incorporate economic aspects commonly economic evaluations are performed. A convergence of recommendations for methods of health economic evaluations between international HTA agencies would facilitate the adaption of results to different settings and avoid unnecessary expense. A first step in this direction is a detailed analysis of existing similarities and differences in recommendations to identify potential for harmonization. The objective is to provide an overview and comparison of the methodological recommendations of international HTA agencies for economic evaluations. The webpages of 127 international HTA agencies were searched for guidelines containing recommendations on methods for the preparation of economic evaluations. Additionally, the HTA agencies were requested information on methods for economic evaluations. Recommendations of the included guidelines were extracted in standardized tables according to 13 methodological aspects. All process steps were performed independently by two reviewers. Finally 25 publications of 14 HTA agencies were included in the analysis. Methods for economic evaluations vary widely. The greatest accordance could be found for the type of analysis and comparator. Cost-utility-analyses or cost-effectiveness-analyses are recommended. The comparator should continuously be usual care. Again the greatest differences were shown in the recommendations on the measurement/sources of effects, discounting and in the analysis of sensitivity. The main difference regarding effects is the focus either on efficacy or effectiveness. Recommended discounting rates range from 1.5%-5% for effects and 3%-5% for costs whereby it is mostly recommended to use the same rate for costs and effects. With respect to the analysis of sensitivity the main difference is that oftentimes the probabilistic or deterministic approach is recommended

Intercomparison of two comparative reactivity method instruments inf the Mediterranean basin during summer 2013

Science.gov (United States)

Zannoni, N.; Dusanter, S.; Gros, V.; Sarda Esteve, R.; Michoud, V.; Sinha, V.; Locoge, N.; Bonsang, B.

2015-09-01

The hydroxyl radical (OH) plays a key role in the atmosphere, as it initiates most of the oxidation processes of volatile organic compounds (VOCs), and can ultimately lead to the formation of ozone and secondary organic aerosols (SOAs). There are still uncertainties associated with the OH budget assessed using current models of atmospheric chemistry and direct measurements of OH sources and sinks have proved to be valuable tools to improve our understanding of the OH chemistry. The total first order loss rate of OH, or total OH reactivity, can be directly measured using three different methods, such as the following: total OH loss rate measurement, laser-induced pump and probe technique and comparative reactivity method. Observations of total OH reactivity are usually coupled to individual measurements of reactive compounds in the gas phase, which are used to calculate the OH reactivity. Studies using the three methods have highlighted that a significant fraction of OH reactivity is often not explained by individually measured reactive compounds and could be associated to unmeasured or unknown chemical species. Therefore accurate and reproducible measurements of OH reactivity are required. The comparative reactivity method (CRM) has demonstrated to be an advantageous technique with an extensive range of applications, and for this reason it has been adopted by several research groups since its development. However, this method also requires careful corrections to derive ambient OH reactivity. Herein we present an intercomparison exercise of two CRM instruments, CRM-LSCE (Laboratoire des Sciences du Climat et de l'Environnement) and CRM-MD (Mines Douai), conducted during July 2013 at the Mediterranean site of Ersa, Cape Corsica, France. The intercomparison exercise included tests to assess the corrections needed by the two instruments to process the raw data sets as well as OH reactivity observations. The observation was divided in three parts: 2 days of plant

A direct method for trajectory optimization of rigid bodies through contact

OpenAIRE

Posa, Michael Antonio; Cantu, Cecilia; Tedrake, Russell Louis

2013-01-01

Direct methods for trajectory optimization are widely used for planning locally optimal trajectories of robotic systems. Many critical tasks, such as locomotion and manipulation, often involve impacting the ground or objects in the environment. Most state-of-the-art techniques treat the discontinuous dynamics that result from impacts as discrete modes and restrict the search for a complete path to a specified sequence through these modes. Here we present a novel method for trajectory planning...

New high accuracy super stable alternating direction implicit methods for two and three dimensional hyperbolic damped wave equations

Directory of Open Access Journals (Sweden)

R.K. Mohanty

2014-01-01

Full Text Available In this paper, we report new three level implicit super stable methods of order two in time and four in space for the solution of hyperbolic damped wave equations in one, two and three space dimensions subject to given appropriate initial and Dirichlet boundary conditions. We use uniform grid points both in time and space directions. Our methods behave like fourth order accurate, when grid size in time-direction is directly proportional to the square of grid size in space-direction. The proposed methods are super stable. The resulting system of algebraic equations is solved by the Gauss elimination method. We discuss new alternating direction implicit (ADI methods for two and three dimensional problems. Numerical results and the graphical representation of numerical solution are presented to illustrate the accuracy of the proposed methods.

A comparative study of wire feeding and powder feeding in direct diode laser deposition for rapid prototyping

Energy Technology Data Exchange (ETDEWEB)

Syed, Waheed Ul Haq [Laser Processing Research Centre, School of Mechanical Aerospace and Civil Engineering, Sackville Street Building, University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom)]. E-mail: w.syed@postgrad.manchester.ac.uk; Pinkerton, Andrew J. [Laser Processing Research Centre, School of Mechanical Aerospace and Civil Engineering, Sackville Street Building, University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom); Li Lin [Laser Processing Research Centre, School of Mechanical Aerospace and Civil Engineering, Sackville Street Building, University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom)

2005-07-15

Metal powder feeding has been used widely in various rapid prototyping and tooling processes such as direct laser deposition (DLD) and layered engineered net shaping (LENS) to achieve near net shape accuracy. Although powder recycling has been practiced, the material usage efficiency has been very low (normally below 30%). This study compares the process characteristics, advantages and disadvantages of wire- and powder-feed DLD. A 1.5 kW diode laser is used to build multiple layer parts, which are compared and analysed in terms of surface finish, microstructure and deposition efficiency. Scanning electron microscopy (SEM), X-ray diffraction and optical microscopy are used for the material characterisation. The microstructure of samples from both the methods is similar, with some porosity found in powder-feed components, but the surface finish and material usage efficiency is better for wire-feed samples. The deposition angle is found to be critical in the case of wire feeding and the characteristics of different feed angles are explored. Possible reasons for the different characteristics of the two deposition techniques are discussed.

Enriching the gene set analysis of genome-wide data by incorporating directionality of gene expression and combining statistical hypotheses and methods

Science.gov (United States)

Väremo, Leif; Nielsen, Jens; Nookaew, Intawat

2013-01-01

Gene set analysis (GSA) is used to elucidate genome-wide data, in particular transcriptome data. A multitude of methods have been proposed for this step of the analysis, and many of them have been compared and evaluated. Unfortunately, there is no consolidated opinion regarding what methods should be preferred, and the variety of available GSA software and implementations pose a difficulty for the end-user who wants to try out different methods. To address this, we have developed the R package Piano that collects a range of GSA methods into the same system, for the benefit of the end-user. Further on we refine the GSA workflow by using modifications of the gene-level statistics. This enables us to divide the resulting gene set P-values into three classes, describing different aspects of gene expression directionality at gene set level. We use our fully implemented workflow to investigate the impact of the individual components of GSA by using microarray and RNA-seq data. The results show that the evaluated methods are globally similar and the major separation correlates well with our defined directionality classes. As a consequence of this, we suggest to use a consensus scoring approach, based on multiple GSA runs. In combination with the directionality classes, this constitutes a more thorough basis for an enriched biological interpretation. PMID:23444143

Comparison of Direct and Indirect Methods of Teaching Breast Self-Examination – Influence on Knowledge and Attitudes of Iranian Nursing and Midwifery Personnel

Science.gov (United States)

Shahbazi, Sara; Heidari, Mohammad; Ghafourifard, Mansour

2017-04-01

Background: Breast cancer is the most common cancer in women. Monthly breast self-examination (BSE) has been presented as one of the best screening methods available. The aim of this study was to compare effects of both direct and indirect methods of teaching of BSE on knowledge and attitudes of nursing and midwifery personnel. Materials and Methods: The present study was performed on 89 nursing and midwifery personnel in Valiasr hospital of Borujen city. Participants were randomly divided into a direct and an indirect training group. Researcher-designed BSE knowledge and attitude and demographic information questionnaires were used for data collection. Results: Before the education intervention, the mean levels of knowledge and attitude were 9.82±2.79 and 56.5±6.21 in the direct training group and 9.59±2.71 and 54.5±4.51 in the indirect training group; after the intervention, they reached 19.2±0.96 and 62.9±4.21, and 11.0±2.58 and 59.0±3.44, respectively. The difference in the mean levels of knowledge and attitude were significantly higher in the direct training group post intervention (Pdirect training methods. Creative Commons Attribution License

Methods for the comparative evaluation of pharmaceuticals.

Science.gov (United States)

Zentner, Annette; Velasco-Garrido, Marcial; Busse, Reinhard

2005-11-15

POLITICAL BACKGROUND: As a German novelty, the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen; IGWiG) was established in 2004 to, among other tasks, evaluate the benefit of pharmaceuticals. In this context it is of importance that patented pharmaceuticals are only excluded from the reference pricing system if they offer a therapeutic improvement. The institute is commissioned by the Federal Joint Committee (Gemeinsamer Bundesausschuss, G-BA) or by the Ministry of Health and Social Security. The German policy objective expressed by the latest health care reform (Gesetz zur Modernisierung der Gesetzlichen Krankenversicherung, GMG) is to base decisions on a scientific assessment of pharmaceuticals in comparison to already available treatments. However, procedures and methods are still to be established. This health technology assessment (HTA) report was commissioned by the German Agency for HTA at the Institute for Medical Documentation and Information (DAHTA@DIMDI). It analysed criteria, procedures, and methods of comparative drug assessment in other EU-/OECD-countries. The research question was the following: How do national public institutions compare medicines in connection with pharmaceutical regulation, i.e. licensing, reimbursement and pricing of drugs? Institutions as well as documents concerning comparative drug evaluation (e.g. regulations, guidelines) were identified through internet, systematic literature, and hand searches. Publications were selected according to pre-defined inclusion and exclusion criteria. Documents were analysed in a qualitative matter following an analytic framework that had been developed in advance. Results were summarised narratively and presented in evidence tables. Currently licensing agencies do not systematically assess a new drug's added value for patients and society. This is why many countries made post-licensing evaluation of pharmaceuticals a

Comparing DIF methods for data with dual dependency

Directory of Open Access Journals (Sweden)

Ying Jin

2016-09-01

Full Text Available Abstract Background The current study compared four differential item functioning (DIF methods to examine their performances in terms of accounting for dual dependency (i.e., person and item clustering effects simultaneously by a simulation study, which is not sufficiently studied under the current DIF literature. The four methods compared are logistic regression accounting neither person nor item clustering effect, hierarchical logistic regression accounting for person clustering effect, the testlet model accounting for the item clustering effect, and the multilevel testlet model accounting for both person and item clustering effects. The secondary goal of the current study was to evaluate the trade-off between simple models and complex models for the accuracy of DIF detection. An empirical example analyzing the 2011 TIMSS Mathematics data was also included to demonstrate the differential performances of the four DIF methods. A number of DIF analyses have been done on the TIMSS data, and rarely had these analyses accounted for the dual dependence of the data. Results Results indicated the complex models did not outperform simple models under certain conditions, especially when DIF parameters were considered in addition to significance tests. Conclusions Results of the current study could provide supporting evidence for applied researchers in selecting the appropriate DIF methods under various conditions.

Measuring larval nematode contamination on cattle pastures: Comparing two herbage sampling methods.

Science.gov (United States)

Verschave, S H; Levecke, B; Duchateau, L; Vercruysse, J; Charlier, J

2015-06-15

Assessing levels of pasture larval contamination is frequently used to study the population dynamics of the free-living stages of parasitic nematodes of livestock. Direct quantification of infective larvae (L3) on herbage is the most applied method to measure pasture larval contamination. However, herbage collection remains labour intensive and there is a lack of studies addressing the variation induced by the sampling method and the required sample size. The aim of this study was (1) to compare two different sampling methods in terms of pasture larval count results and time required to sample, (2) to assess the amount of variation in larval counts at the level of sample plot, pasture and season, respectively and (3) to calculate the required sample size to assess pasture larval contamination with a predefined precision using random plots across pasture. Eight young stock pastures of different commercial dairy herds were sampled in three consecutive seasons during the grazing season (spring, summer and autumn). On each pasture, herbage samples were collected through both a double-crossed W-transect with samples taken every 10 steps (method 1) and four random located plots of 0.16 m(2) with collection of all herbage within the plot (method 2). The average (± standard deviation (SD)) pasture larval contamination using sampling methods 1 and 2 was 325 (± 479) and 305 (± 444)L3/kg dry herbage (DH), respectively. Large discrepancies in pasture larval counts of the same pasture and season were often seen between methods, but no significant difference (P = 0.38) in larval counts between methods was found. Less time was required to collect samples with method 2. This difference in collection time between methods was most pronounced for pastures with a surface area larger than 1 ha. The variation in pasture larval counts from samples generated by random plot sampling was mainly due to the repeated measurements on the same pasture in the same season (residual variance

Analysis and development of adjoint-based h-adaptive direct discontinuous Galerkin method for the compressible Navier-Stokes equations

Science.gov (United States)

Cheng, Jian; Yue, Huiqiang; Yu, Shengjiao; Liu, Tiegang

2018-06-01

In this paper, an adjoint-based high-order h-adaptive direct discontinuous Galerkin method is developed and analyzed for the two dimensional steady state compressible Navier-Stokes equations. Particular emphasis is devoted to the analysis of the adjoint consistency for three different direct discontinuous Galerkin discretizations: including the original direct discontinuous Galerkin method (DDG), the direct discontinuous Galerkin method with interface correction (DDG(IC)) and the symmetric direct discontinuous Galerkin method (SDDG). Theoretical analysis shows the extra interface correction term adopted in the DDG(IC) method and the SDDG method plays a key role in preserving the adjoint consistency. To be specific, for the model problem considered in this work, we prove that the original DDG method is not adjoint consistent, while the DDG(IC) method and the SDDG method can be adjoint consistent with appropriate treatment of boundary conditions and correct modifications towards the underlying output functionals. The performance of those three DDG methods is carefully investigated and evaluated through typical test cases. Based on the theoretical analysis, an adjoint-based h-adaptive DDG(IC) method is further developed and evaluated, numerical experiment shows its potential in the applications of adjoint-based adaptation for simulating compressible flows.

An investigation to compare the performance of methods for the determination of free acid in highly concentrated solutions of plutonium and uranium nitrate

International Nuclear Information System (INIS)

Crossley, D.

1980-08-01

An investigation has been carried out to compare the performance of the direct titration method and the indirect mass balance method, for the determination of free acid in highly concentrated solutions of uranium nitrate and plutonium nitrate. The direct titration of free acid with alkali is carried out in a fluoride medium to avoid interference from the hydrolysis of uranium or plutonium, while free acid concentration by the mass balance method is obtained by calculation from the metal concentration, metal valency state, and total nitrate concentration in a sample. The Gran plot end-point prediction technique has been used extensively in the investigation to gain information concerning the hydrolysis of uranium and plutonium in fluoride media and in other complexing media. The use of the Gran plot technique has improved the detection of the end-point of the free acid titration which gives an improvement in the precision of the determination. The experimental results obtained show that there is good agreement between the two methods for the determination of free acidity, and that the precision of the direct titration method in a fluoride medium using the Gran plot technique to detect the end-point is 0.75% (coefficient of variation), for a typical separation plant plutonium nitrate solution. The performance of alternative complexing agents in the direct titration method has been studied and is discussed. (author)

Quasar Parallax: a Method for Determining Direct Geometrical Distances to Quasars

OpenAIRE

Elvis, Martin; Karovska, Margarita

2002-01-01

We describe a novel method to determine direct geometrical distances to quasars that can measure the cosmological constant, Lambda, with minimal assumptions. This method is equivalent to geometric parallax, with the `standard length' being the size of the quasar broad emission line region (BELR) as determined from the light travel time measurements of reverberation mapping. The effect of non-zero Lambda on angular diameter is large, 40% at z=2, so mapping angular diameter distances vs. redshi...

Gap-Filling of Landsat 7 Imagery Using the Direct Sampling Method

KAUST Repository

Yin, Gaohong

2016-12-28

The failure of the Scan Line Corrector (SLC) on Landsat 7 imposed systematic data gaps on retrieved imagery and removed the capacity to provide spatially continuous fields. While a number of methods have been developed to fill these gaps, most of the proposed techniques are only applicable over relatively homogeneous areas. When they are applied to heterogeneous landscapes, retrieving image features and elements can become challenging. Here we present a gap-filling approach that is based on the adoption of the Direct Sampling multiple-point geostatistical method. The method employs a conditional stochastic resampling of known areas in a training image to simulate unknown locations. The approach is assessed across a range of both homogeneous and heterogeneous regions. Simulation results show that for homogeneous areas, satisfactory results can be obtained by simply adopting non-gap locations in the target image as baseline training data. For heterogeneous landscapes, bivariate simulations using an auxiliary variable acquired at a different date provides more accurate results than univariate simulations, especially as land cover complexity increases. Apart from recovering spatially continuous fields, one of the key advantages of the Direct Sampling is the relatively straightforward implementation process that relies on relatively few parameters.

Apparatus and method for comparing corresponding acoustic resonances in liquids

Science.gov (United States)

Sinha, Dipen N.

1999-01-01

Apparatus and method for comparing corresponding acoustic resonances in liquids. The present invention permits the measurement of certain characteristics of liquids which affect the speed of sound therein. For example, a direct correlation between the octane rating of gasoline and the speed of sound in a gasoline sample has been experimentally observed. Therefore, changes in the speed of sound therein can be utilized as a sensitive parameter for determining changes in composition of a liquid sample. The present apparatus establishes interference patterns inside of a liquid without requiring the use of very thin, rigorously parallel ceramic discs, but rather uses readily available piezoelectric transducers attached to the outside surface of the usual container for the liquid and located on the same side thereof in the vicinity of one another. That is, various receptacle geometries may be employed, and the driving and receiving transducers may be located on the same side of the receptacle. The cell may also be constructed of any material that is inert to the liquid under investigation. A single-transducer embodiment, where the same transducer provides the excitation to the sample container and receives signals impressed therein, is also described.

Photovoltaic pumping system - Comparative study analysis between direct and indirect coupling mode

Science.gov (United States)

Harrag, Abdelghani; Titraoui, Abdessalem; Bahri, Hamza; Messalti, Sabir

2017-02-01

In this paper, P&O algorithm is used in order to improve the performance of photovoltaic water pumping system in both dynamic and static response. The efficiency of the proposed algorithm has been studied successfully using a DC motor-pump powered using controller by thirty six PV modules via DC-DC boost converter derived by a P&O MPPT algorithm. Comparative study results between the direct and indirect modes coupling confirm that the proposed algorithm can effectively improve simultaneously: accuracy, rapidity, ripple and overshoot.

The comparative method of language acquisition research: a Mayan case study.

Science.gov (United States)

Pye, Clifton; Pfeiler, Barbara

2014-03-01

This article demonstrates how the Comparative Method can be applied to cross-linguistic research on language acquisition. The Comparative Method provides a systematic procedure for organizing and interpreting acquisition data from different languages. The Comparative Method controls for cross-linguistic differences at all levels of the grammar and is especially useful in drawing attention to variation in contexts of use across languages. This article uses the Comparative Method to analyze the acquisition of verb suffixes in two Mayan languages: K'iche' and Yucatec. Mayan status suffixes simultaneously mark distinctions in verb transitivity, verb class, mood, and clause position. Two-year-old children acquiring K'iche' and Yucatec Maya accurately produce the status suffixes on verbs, in marked distinction to the verbal prefixes for aspect and agreement. We find evidence that the contexts of use for the suffixes differentially promote the children's production of cognate status suffixes in K'iche' and Yucatec.

Preliminary experiment of fast neutron imaging with direct-film method

International Nuclear Information System (INIS)

Pei Yuyang; Tang Guoyou; Guo Zhiyu; Zhang Guohui

2005-01-01

A preliminary experiment is conducted with direct-film method under the condition that fast neutron is generated by the reaction of 9 Be(d, n) on the Beijing University 4.5 MV Van de Graaff, whose energy is lower than 7 MeV. Basic characteristics of direct-film neutron radiography system are investigated with the help of samples in different materials, different thickness and holes of different diameter. The fast neutron converter, which is vital for fast neutron imaging, is produced with the materials made in China. The result indicates that fast neutron converter can meet the requirement of fast neutron imaging; further research of fast neutron imaging can be conducted on the accelerator and neutron-generator in China. (authors)

Is transcranial direct current stimulation a potential method for improving response inhibition?

Science.gov (United States)

Kwon, Yong Hyun; Kwon, Jung Won

2013-04-15

Inhibitory control of movement in motor learning requires the ability to suppress an inappropriate action, a skill needed to stop a planned or ongoing motor response in response to changes in a variety of environments. This study used a stop-signal task to determine whether transcranial direct-current stimulation over the pre-supplementary motor area alters the reaction time in motor inhibition. Forty healthy subjects were recruited for this study and were randomly assigned to either the transcranial direct-current stimulation condition or a sham-transcranial direct-current stimulation condition. All subjects consecutively performed the stop-signal task before, during, and after the delivery of anodal transcranial direct-current stimulation over the pre-supplementary motor area (pre-transcranial direct-current stimulation phase, transcranial direct-current stimulation phase, and post-transcranial direct-current stimulation phase). Compared to the sham condition, there were significant reductions in the stop-signal processing times during and after transcranial direct-current stimulation, and change times were significantly greater in the transcranial direct-current stimulation condition. There was no significant change in go processing-times during or after transcranial direct-current stimulation in either condition. Anodal transcranial direct-current stimulation was feasibly coupled to an interactive improvement in inhibitory control. This coupling led to a decrease in the stop-signal process time required for the appropriate responses between motor execution and inhibition. However, there was no transcranial direct-current stimulation effect on the no-signal reaction time during the stop-signal task. Transcranial direct-current stimulation can adjust certain behaviors, and it could be a useful clinical intervention for patients who have difficulties with response inhibition.

Fuel coolant interaction experiment by direct electrical heating method

International Nuclear Information System (INIS)

Takeda, Tsuneo; Hirano, Kenmei

1979-01-01

In the PCM (Power Cooling Mismatch) experiments, the FCI (Fuel Coolant Interaction) test is one of necessary tests in order to predict various phenomena that occur during PCM in the core. A direct electrical heating method is used for the FCI tests for fuel pellet temperature of over 1000 0 C. Therefore, preheating is required before initiating the direct electrical heating. The fuel pin used in the FCI tests is typical LWR fuel element, which is surrounded by coolant water. It is undersirable to heat up the coolant water during preheating of the fuel pin. Therefore, a zirconia (ZrO 2 ) pellet which is similar to a UO 2 pellet in physical and chemical properties is used. Electric property (electric conductivity) of ZrO 2 is particularly suitable for direct electrical heating as in the case of UO 2 . In this experiment, ZrO 2 pellet (melting point 2500 0 C) melting was achieved by use of both preheating and direct electrical heating. Temperature changes of coolant and fuel surface, as well as the pressure change of coolant water, were measured. The molten fuel interacted with the coolant and generated shock waves. A portion of this molten fuel fragmented into small particles during this interaction. The peak pressure of the observed shock wave was about 35 bars. The damaged fuel pin was photographed after disassembly. This report shows the measured coolant pressure changes and the coolant temperature changes, as well as photographs of damaged fuel pin and fuel fragments. (author)

Experimental Method for Characterizing Electrical Steel Sheets in the Normal Direction

Directory of Open Access Journals (Sweden)

Thierry Belgrand

2010-10-01

Full Text Available This paper proposes an experimental method to characterise magnetic laminations in the direction normal to the sheet plane. The principle, which is based on a static excitation to avoid planar eddy currents, is explained and specific test benches are proposed. Measurements of the flux density are made with a sensor moving in and out of an air-gap. A simple analytical model is derived in order to determine the permeability in the normal direction. The experimental results for grain oriented steel sheets are presented and a comparison is provided with values obtained from literature.

Directly comparing GW150914 with numerical solutions of Einstein's equations for binary black hole coalescence

NARCIS (Netherlands)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Phythian-Adams, A.T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.T.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, R.D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Bejger, M.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, M.J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, A.L.S.; Bock, O.; Boer, M.; Bogaert, J.G.; Bogan, C.; Bohe, A.; Bond, T.C; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, A.D.; Brown, D.; Brown, N. M.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Bustillo, J. Calderon; Callister, T. A.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Diaz, J. Casanueva; Casentini, C.; Caudill, S.; Cavaglia, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Baiardi, L. Cerboni; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, D. S.; Charlton, P.; Chassande-Mottin, E.; Cheeseboro, B. D.; Chen, H. Y.; Chen, Y; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Qian; Chua, S. E.; Chung, E.S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P. -F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M., Jr.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, A.C.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J. -P.; Countryman, S. T.; Couvares, P.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, A.L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dasgupta, A.; Costa, C. F. Da Silva; Dattilo, V.; Dave, I.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; De, S.; Debra, D.; Debreczeni, G.; Degallaix, J.; De laurentis, M.; Deleglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.A.; Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Devine, R. C.; Dhurandhar, S.; Diaz, M. C.; Di Fiore, L.; Giovanni, M.G.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H. -B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, T. M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fan, X.M.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Fenyvesi, E.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M; Fournier, J. -D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Geng, P.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.P.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; Gonzalez, Idelmis G.; Castro, J. M. Gonzalez; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Lee-Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.M.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Buffoni-Hall, R.; Hall, E. D.; Hammond, G.L.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hanson, P.J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C. -J.; Haughian, K.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Henry, J.A.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huang, S.; Huerta, E. A.; Huet, D.; Hughey, B.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J. -M.; Isi, M.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jang, D.H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jian, L.; Jimenez-Forteza, F.; Johnson, W.; Jones, I.D.; Jones, R.; Jonker, R. J. G.; Ju, L.; Haris, K.; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.H.; Kanner, J. B.; Kapadia, S. J.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kefelian, F.; Kehl, M. S.; Keitel, D.; Kelley, D. B.; Kells, W.; Kennedy, R.E.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chi-Woong; Kim, Chunglee; Kim, J.; Kim, K.; Kim, Namjun; Kim, W.; Kim, Y.M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kissel, J. S.; Klein, B.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Krolak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kumar, R.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C.H.; Lee, K.H.; Lee, M.H.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Lewis, J. B.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Lombardi, A. L.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lueck, H.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magana-Sandoval, F.; Zertuche, L. Magana; Magee, R. M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marka, S.; Marka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, A. L.; Miller, B.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B.C.; Moore, J.C.; Moraru, D.; Gutierrez Moreno, M.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, S.D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P.G.; Mytidis, A.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Nedkova, K.; Nelemans, G.; Nelson, T. J. N.; Gutierrez-Neri, M.; Neunzert, A.; Newton-Howes, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J.; Oh, S. H.; Ohme, F.; Oliver, M. B.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.S; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perreca, A.; Perri, L. M.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Puerrer, M.; Qi, H.; Qin, J.; Qiu, S.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Ricci, F.; Riles, K.; Rizzo, D.M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, J. D.; Romano, R.; Romanov, G.; Romie, J. H.; Rosinska, D.; Rowan, S.; Ruediger, A.; Ruggi, P.; Ryan, K.A.; Sachdev, P.S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Saulson, P. R.; Sauter, O. E. S.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J; Schmidt, P.; Schnabel, R.B.; Schofield, R. M. S.; Schoenbeck, A.; Schreiber, K.E.C.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, M.S.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Setyawati, Y.; Shaddock, D. A.; Shaffer, T. J.; Shahriar, M. S.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, António Dias da; Singer, A; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, R. J. E.; Smith, N.D.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stone, J.R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S. E.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Sutton, P. J.; Swinkels, B. L.; Szczepanczyk, M. J.; Tacca, M.D.; Talukder, D.; Tanner, D. B.; Tapai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, W.R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tomlinson, C.; Tonelli, M.; Tornasi, Z.; Torres, C. V.; Torrie, C. I.; Toyra, D.; Travasso, F.; Traylor, G.; Trifiro, D.; Tringali, M. C.; Trozzo, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; Van Beuzekom, Martin; van den Brand, J. F. J.; Van Den Broeck, C.F.F.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasuth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P.J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Vicere, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J. -Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, MT; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, X.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L. -W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.M.; Wessels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Williams, D.R.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Worden, J.; Wright, J.L.; Wu, D.S.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yu, H.; Yvert, M.; Zadrozny, A.; Zangrando, L.; Zanolin, M.; Zendri, J. -P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.; Boyle, M.; Campanelli, M.; Chu, I.W.T.; Clark, M.; Fauchon-Jones, E. J.; Fong, H.; Healy, J.; Hemberger, D.; Hinder, I.; Husa, S.; Kalaghati, C.; Khan., S.; Kidder, L. E.; Kinsey, M.; Laguna, P.; London, L. T.; Lousto, C. O.; Lovelace, G.; Ossokine, S.; Pannarale, F.; Pfeiffer, H. P.; Scheel, M.; Shoemaker, D. M.; Szilagyi, B.; Teukolsky, S.; Vinuales, A. Vano; Zlochower, Y.

2016-01-01

We compare GW150914 directly to simulations of coalescing binary black holes in full general relativity, including several performed specifically to reproduce this event. Our calculations go beyond existing semianalytic models, because for all simulations—including sources with two independent,

Development of spectral history methods for pin-by-pin core analysis method using three-dimensional direct response matrix

International Nuclear Information System (INIS)

Mitsuyasu, T.; Ishii, K.; Hino, T.; Aoyama, M.

2009-01-01

Spectral history methods for pin-by-pin core analysis method using the three-dimensional direct response matrix have been developed. The direct response matrix is formalized by four sub-response matrices in order to respond to a core eigenvalue k and thus can be recomposed at each outer iteration in the core analysis. For core analysis, it is necessary to take into account the burn-up effect related to spectral history. One of the methods is to evaluate the nodal burn-up spectrum obtained using the out-going neutron current. The other is to correct the fuel rod neutron production rates obtained the pin-by-pin correction. These spectral history methods were tested in a heterogeneous system. The test results show that the neutron multiplication factor error can be reduced by half during burn-up, the nodal neutron production rates errors can be reduced by 30% or more. The root-mean-square differences between the relative fuel rod neutron production rate distributions can be reduced within 1.1% error. This means that these methods can accurately reflect the effects of intra- and inter-assembly heterogeneities during burn-up and can be used for core analysis. Core analysis with the DRM method was carried out for an ABWR quarter core and it was found that both thermal power and coolant-flow distributions were smoothly converged. (authors)

Development of multilateral comparative evaluation method for fuel cycle system

International Nuclear Information System (INIS)

Tamaki, Hitoshi; Ikushima, Takeshi; Nomura, Yasushi; Nakajima, Kiyoshi.

1998-03-01

In the near future, Japanese nuclear fuel cycle system will be promoted by national nuclear energy policy, and it''s options i.e. once through, thermal cycle and fast breeder cycle must be selected by multilateral comparative evaluation method from various aspects of safety, society, economy, and e.t.c. Therefore such a problem can be recognized as a social problem of decision making and applied for AHP (Analytic Hierarchy Process) that can multilaterally and comparatively evaluate the problem. On comparative evaluation, much information are needed for decision making, therefore two kinds of databases having these information have been constructed. And then, the multilateral comparative evaluation method consisting of two kinds of databases and AHP for optimum selection of fuel cycle system option have been developed. (author)

Direct fourier methods in 3D-reconstruction from cone-beam data

International Nuclear Information System (INIS)

Axelsson, C.

1994-01-01

The problem of 3D-reconstruction is encountered in both medical and industrial applications of X-ray tomography. A method able to utilize a complete set of projections complying with Tuys condition was proposed by Grangeat. His method is mathematically exact and consists of two distinct phases. In phase 1 cone-beam projection data are used to produce the derivative of the radon transform. In phase 2, after interpolation, the radon transform data are used to reconstruct the three-dimensional object function. To a large extent our method is an extension of the Grangeat method. Our aim is to reduce the computational complexity, i.e. to produce a faster method. The most taxing procedure during phase 1 is computation of line-integrals in the detector plane. By applying the direct Fourier method in reverse for this computation, we reduce the complexity of phase 1 from O(N 4 ) to O(N 3 logN). Phase 2 can be performed either as a straight 3D-reconstruction or as a sequence of two 2D-reconstructions in vertical and horizontal planes, respectively. Direct Fourier methods can be applied for the 2D- and for the 3D-reconstruction, which reduces the complexity of phase 2 from O(N 4 ) to O(N 3 logN) as well. In both cases, linogram techniques are applied. For 3D-reconstruction the inversion formula contains the second derivative filter instead of the well-known ramp-filter employed in the 2D-case. The derivative filter is more well-behaved than the 2D ramp-filter. This implies that less zeropadding is necessary which brings about a further reduction of the computational efforts. The method has been verified by experiments on simulated data. The image quality is satisfactory and independent of cone-beam angles. For a 512 3 volume we estimate that our method is ten times faster than Grangeats method

Describing the organization of dominance relationships by dominance-directed tree method.

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Izar, Patrícia; Ferreira, Renata G; Sato, Takechi

2006-02-01

Methods to describe dominance hierarchies are a key tool in primatology studies. Most current methods are appropriate for analyzing linear and near-linear hierarchies; however, more complex structures are common in primate groups. We propose a method termed "dominance-directed tree." This method is based on graph theory and set theory to analyze dominance relationships in social groups. The method constructs a transitive matrix by imposing transitivity to the dominance matrix and produces a graphical representation of the dominance relationships, which allows an easy visualization of the hierarchical position of the individuals, or subsets of individuals. The method is also able to detect partial and complete hierarchies, and to describe situations in which hierarchical and nonhierarchical principles operate. To illustrate the method, we apply a dominance tree analysis to artificial data and empirical data from a group of Cebus apella. Copyright 2006 Wiley-Liss, Inc.

Comparative study of methods for potential and actual evapotranspiration determination

International Nuclear Information System (INIS)

Kolev, B.

2004-01-01

Two types of methods for potential and actual evapotranspiration determining were compared. The first type includes neutron gauge, tensiometers, gypsum blocks and lysimeters. The actual and potential evapotranspiration were calculated by water balance equation. The second type of methods used a simulation model for all calculation. The aim of this study was not only to compare and estimate the methods using. It was mainly pointed on calculations of water use efficiency and transpiration coefficient in potential production situation. This makes possible to choose the best way for water consumption optimization for a given crop. The final results find with the best of the methods could be used for applying the principles of sustainable agriculture in random region of Bulgarian territory. (author)

Comparative Study on Two Melting Simulation Methods: Melting Curve of Gold

International Nuclear Information System (INIS)

Liu Zhong-Li; Li Rui; Sun Jun-Sheng; Zhang Xiu-Lu; Cai Ling-Cang

2016-01-01

Melting simulation methods are of crucial importance to determining melting temperature of materials efficiently. A high-efficiency melting simulation method saves much simulation time and computational resources. To compare the efficiency of our newly developed shock melting (SM) method with that of the well-established two-phase (TP) method, we calculate the high-pressure melting curve of Au using the two methods based on the optimally selected interatomic potentials. Although we only use 640 atoms to determine the melting temperature of Au in the SM method, the resulting melting curve accords very well with the results from the TP method using much more atoms. Thus, this shows that a much smaller system size in SM method can still achieve a fully converged melting curve compared with the TP method, implying the robustness and efficiency of the SM method. (paper)

Lichtenstein Mesh Repair (LMR) v/s Modified Bassini’s Repair (MBR) + Lichtenstein Mesh Repair of Direct Inguinal Hernias in Rural Population – A Comparative Study

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Patil, Santosh M; Kumar, Ashok; Kumar, Kuthadi Sravan; Mithun, Gorre

2016-01-01

Introduction Lichtenstein’s tension free mesh hernioplasty is the commonly done open technique for inguinal hernias. As our hospital is in rural area, majority of patients are labourers, open hernias are commonly done. The present study was done by comparing Lichtenstein Mesh Repair (LMR) v/s Modified Bassini’s repair (MBR) + Lichtenstein mesh repair (LMR) of direct Inguinal Hernias to compare the technique of both surgeries and its outcome like postoperative complications and recurrence rate. Materials and Methods A comparative randomized study was conducted on patients reporting to MNR hospital, sangareddy with direct inguinal hernias. A total of fifty consecutive patients were included in this study of which, 25 patients were operated by LMR and 25 patients were operated by MBR+LMR and followed up for a period of two years. The outcomes of the both techniques were compared. Results Study involved 25 each of Lichtenstein’s mesh repair (LMR) and modified bassini’s repair (MBR) + LMR, over a period of 2 years. The duration of surgery for lichtenstein mesh repair is around 34.56 min compared to LMR+MBR, which is 47.56 min which was statistically significant (p-value is MBR group in POD 1, but not statistically significant (p-value is 0.0949) and from POD 7 the pain was almost similar in both groups. The recurrence rate is 2% for LMR and 0% for MBR+LMR. Conclusion LMR+MBR was comparatively better than only LMR in all direct inguinal hernias because of low recurrence rate (0%) and low postoperative complications, which showed in our present study. PMID:27042517

Comparative Analysis of Direct Hospital Care Costs between Aseptic and Two-Stage Septic Knee Revision

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Kasch, Richard; Merk, Sebastian; Assmann, Grit; Lahm, Andreas; Napp, Matthias; Merk, Harry; Flessa, Steffen

2017-01-01

Background The most common intermediate and long-term complications of total knee arthroplasty (TKA) include aseptic and septic failure of prosthetic joints. These complications cause suffering, and their management is expensive. In the future the number of revision TKA will increase, which involves a greater financial burden. Little concrete data about direct costs for aseptic and two-stage septic knee revisions with an in depth-analysis of septic explantation and implantation is available. Questions/Purposes A retrospective consecutive analysis of the major partial costs involved in revision TKA for aseptic and septic failure was undertaken to compare 1) demographic and clinical characteristics, and 2) variable direct costs (from a hospital department’s perspective) between patients who underwent single-stage aseptic and two-stage septic revision of TKA in a hospital providing maximum care. We separately analyze the explantation and implantation procedures in septic revision cases and identify the major cost drivers of knee revision operations. Methods A total of 106 consecutive patients (71 aseptic and 35 septic) was included. All direct costs of diagnosis, surgery, and treatment from the hospital department’s perspective were calculated as real purchase prices. Personnel involvement was calculated in units of minutes. Results Aseptic versus septic revisions differed significantly in terms of length of hospital stay (15.2 vs. 39.9 days), number of reported secondary diagnoses (6.3 vs. 9.8) and incision-suture time (108.3 min vs. 193.2 min). The management of septic revision TKA was significantly more expensive than that of aseptic failure ($12,223.79 vs. $6,749.43) (p costs of explantation stage ($4,540.46) were lower than aseptic revision TKA ($6,749.43) which were again lower than those of the septic implantation stage ($7,683.33). All mean costs of stays were not comparable as they differ significantly (p cost drivers were the cost of the implant and

Direct injection of {sup 188}Re-microspheres in the treatment of hepatocellular carcinoma. Compared with traditional percutaneous ethanol injection: an animal study

Energy Technology Data Exchange (ETDEWEB)

Lin, Y.C.; Lee, J.C.; Huang, Y.S. [Dept. of Veterinary Medicine, National Chung-Hsing Univ., Taichung (Taiwan); Dept. of Nuclear Medicine (Taiwan); Tsai, S.C. [Show Chwan Memorial Hospital (Taiwan); Hung, G.U. [Changhua Christian Hospital, Changhua (Taiwan); Lin, W.Y. [Taichung Veterans General Hospital, Taichung (Taiwan)

2005-07-01

The aim of this study was to compare the therapeutic efficacies of direct intratumoural injection of {sup 188}Re microspheres (DIRM) and direct intratumoural injection of ethanol (DIE) in rabbits bearing liver tumours. Materials and methods: Fifteen rabbits bearing liver tumours were divided into three groups: group 1 received DIE, group 2 received DIRM, and group 3 (control) received saline. Tumour size was measured by liver sonography before injection, as well as 2, 4, 8, and 12 weeks after injection. Survival time was calculated from the day of treatment to three months after treatment by Kaplan-Meier survival analysis. Results: The mean survival time was 68{+-}9.8 days for the rabbits in the DIRM group, 55.8{+-}11.8 days for the DIE group, and 38.8{+-}6.2 days for the control group. Conclusion: The rabbits survived longer in the DIRM group than in the DIE group although there is no statistical significance. We believe the DIRM method has a good potential to be an alternative to DIE for the treatment of liver tumours. (orig.)

Comparative study on gene set and pathway topology-based enrichment methods.

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Bayerlová, Michaela; Jung, Klaus; Kramer, Frank; Klemm, Florian; Bleckmann, Annalen; Beißbarth, Tim

2015-10-22

Enrichment analysis is a popular approach to identify pathways or sets of genes which are significantly enriched in the context of differentially expressed genes. The traditional gene set enrichment approach considers a pathway as a simple gene list disregarding any knowledge of gene or protein interactions. In contrast, the new group of so called pathway topology-based methods integrates the topological structure of a pathway into the analysis. We comparatively investigated gene set and pathway topology-based enrichment approaches, considering three gene set and four topological methods. These methods were compared in two extensive simulation studies and on a benchmark of 36 real datasets, providing the same pathway input data for all methods. In the benchmark data analysis both types of methods showed a comparable ability to detect enriched pathways. The first simulation study was conducted with KEGG pathways, which showed considerable gene overlaps between each other. In this study with original KEGG pathways, none of the topology-based methods outperformed the gene set approach. Therefore, a second simulation study was performed on non-overlapping pathways created by unique gene IDs. Here, methods accounting for pathway topology reached higher accuracy than the gene set methods, however their sensitivity was lower. We conducted one of the first comprehensive comparative works on evaluating gene set against pathway topology-based enrichment methods. The topological methods showed better performance in the simulation scenarios with non-overlapping pathways, however, they were not conclusively better in the other scenarios. This suggests that simple gene set approach might be sufficient to detect an enriched pathway under realistic circumstances. Nevertheless, more extensive studies and further benchmark data are needed to systematically evaluate these methods and to assess what gain and cost pathway topology information introduces into enrichment analysis. Both

The finite element model for the propagation of light in scattering media: a direct method for domains with nonscattering regions.

Science.gov (United States)

Arridge, S R; Dehghani, H; Schweiger, M; Okada, E

2000-01-01

We present a method for handling nonscattering regions within diffusing domains. The method develops from an iterative radiosity-diffusion approach using Green's functions that was computationally slow. Here we present an improved implementation using a finite element method (FEM) that is direct. The fundamental idea is to introduce extra equations into the standard diffusion FEM to represent nondiffusive light propagation across a nonscattering region. By appropriate mesh node ordering the computational time is not much greater than for diffusion alone. We compare results from this method with those from a discrete ordinate transport code, and with Monte Carlo calculations. The agreement is very good, and, in addition, our scheme allows us to easily model time-dependent and frequency domain problems.

Comparative study on diagonal equivalent methods of masonry infill panel

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Amalia, Aniendhita Rizki; Iranata, Data

2017-06-01

Infrastructure construction in earthquake prone area needs good design process, including modeling a structure in a correct way to reduce damages caused by an earthquake. Earthquakes cause many damages e.g. collapsed buildings that are dangerous. An incorrect modeling in design process certainly affects the structure's ability in responding to load, i.e. an earthquake load, and it needs to be paid attention to in order to reduce damages and fatalities. A correct modeling considers every aspect that affects the strength of a building, including stiffness of resisting lateral loads caused by an earthquake. Most of structural analyses still use open frame method that does not consider the effect of stiffness of masonry panel to the stiffness and strength of the whole structure. Effect of masonry panel is usually not included in design process, but the presence of this panel greatly affects behavior of the building in responding to an earthquake. In worst case scenario, it can even cause the building to collapse as what has been reported after great earthquakes worldwide. Modeling a structure with masonry panel as consideration can be performed by designing the panel as compression brace or shell element. In designing masonry panel as a compression brace, there are fourteen methods popular to be used by structure designers formulated by Saneinejad-Hobbs, Holmes, Stafford-Smith, Mainstones, Mainstones-Weeks, Bazan-Meli, Liauw Kwan, Paulay and Priestley, FEMA 356, Durani Luo, Hendry, Al-Chaar, Papia and Chen-Iranata. Every method has its own equation and parameters to use, therefore the model of every method was compared to results of experimental test to see which one gives closer values. Moreover, those methods also need to be compared to the open frame to see if they can result values within limits. Experimental test that was used in comparing all methods was taken from Mehrabi's research (Fig. 1), which was a prototype of a frame in a structure with 0.5 scale and the

Comparative study on spreading function for directional wave spectra

Digital Repository Service at National Institute of Oceanography (India)

Bhat, S.S.; Anand, N.M.; Nayak, B.U.

-dimensional wave energy S(f) and the directional spreading function D(f, theta). This paper reviews various spreading functions proposed in the past for estimating the directional wave energy and presents their application to the Indian wave condition. It is found...

Acute psycho-social stress does not disrupt item-method directed forgetting, emotional stimulus content does.

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Zwissler, Bastian; Koessler, Susanne; Engler, Harald; Schedlowski, Manfred; Kissler, Johanna

2011-03-01

It has been shown that stress affects episodic memory in general, but knowledge about stress effects on memory control processes such as directed forgetting is sparse. Whereas in previous studies item-method directed forgetting was found to be altered in post-traumatic stress disorder patients and abolished for highly arousing negative pictorial stimuli in students, no study so far has investigated the effects of experimentally induced psycho-social stress on this task or examined the role of positive picture stimuli. In the present study, 41 participants performed an item-method directed forgetting experiment while being exposed either to a psychosocial laboratory stressor, the Trier Social Stress Test (TSST), or a cognitively challenging but non-stressful control condition. Neutral and positive pictures were presented as stimuli. As predicted, salivary cortisol level as a biological marker of the human stress response increased only in the TSST group. Still, both groups showed directed forgetting. However, emotional content of the employed stimuli affected memory control: Directed forgetting was intact for neutral pictures whereas it was attenuated for positive ones. This attenuation was primarily due to selective rehearsal improving discrimination accuracy for neutral, but not positive, to-be-remembered items. Results suggest that acute experimentally induced stress does not alter item-method directed forgetting while emotional stimulus content does. Copyright © 2011 Elsevier Inc. All rights reserved.

Comparative Evaluations of Four Specification Methods for Real-Time Systems

Science.gov (United States)

1989-12-01

December 1989 Comparative Evaluations of Four Specification Methods for Real - Time Systems David P. Wood William G. Wood Specification and Design Methods...Methods for Real - Time Systems Abstract: A number of methods have been proposed in the last decade for the specification of system and software requirements...and software specification for real - time systems . Our process for the identification of methods that meet the above criteria is described in greater

A direct method for soil-structure interaction analysis based on frequency-dependent soil masses

International Nuclear Information System (INIS)

Danisch, R.; Delinic, K.; Marti, J.; Trbojevic, V.M.

1993-01-01

In a soil-structure interaction analysis, the soil, as a subsystem of the global vibrating system, exerts a strong influence on the response of the nuclear reactor building to the earthquake excitation. The volume of resources required for dealing with the soil have led to a number of different types of frequency-domain solutions, most of them based on the impedance function approach. These procedures require coupling the soil to the lumped-mass finite-element model of the reactor building. In most practical cases, the global vibrating system is analysed in the time domain (i.e. modal time history, linear or non-linear direct time-integration). Hence, it follows that the frequency domain solution for soil must be converted to an 'equivalent' soil model in the time domain. Over the past three decades, different approaches have been developed and used for earthquake analysis of nuclear power plants. In some cases, difficulties experienced in modelling the soil have affected the methods of global analysis, thus leading to approaches like the substructuring technique, e.g. 3-step method. In the practical applications, the limitations of each specific method must be taken into account in order to avoid unrealistic results. The aim of this paper is to present the recent development on an equivalent SDOF system for soil including frequency-dependent soil masses. The method will be compared with the classical 3-step method. (author)

Method and apparatus for high-efficiency direct contact condensation

Science.gov (United States)

Bharathan, Desikan; Parent, Yves; Hassani, A. Vahab

1999-01-01

A direct contact condenser having a downward vapor flow chamber and an upward vapor flow chamber, wherein each of the vapor flow chambers includes a plurality of cooling liquid supplying pipes and a vapor-liquid contact medium disposed thereunder to facilitate contact and direct heat exchange between the vapor and cooling liquid. The contact medium includes a plurality of sheets arranged to form vertical interleaved channels or passageways for the vapor and cooling liquid streams. The upward vapor flow chamber also includes a second set of cooling liquid supplying pipes disposed beneath the vapor-liquid contact medium which operate intermittently in response to a pressure differential within the upward vapor flow chamber. The condenser further includes separate wells for collecting condensate and cooling liquid from each of the vapor flow chambers. In alternate embodiments, the condenser includes a cross-current flow chamber and an upward flow chamber, a plurality of upward flow chambers, or a single upward flow chamber. The method of use of the direct contact condenser of this invention includes passing a vapor stream sequentially through the downward and upward vapor flow chambers, where the vapor is condensed as a result of heat exchange with the cooling liquid in the contact medium. The concentration of noncondensable gases in the resulting condensate-liquid mixtures can be minimized by controlling the partial pressure of the vapor, which depends in part upon the geometry of the vapor-liquid contact medium. In another aspect of this invention, the physical and chemical performance of a direct contact condenser can be predicted based on the vapor and coolant compositions, the condensation conditions. and the geometric properties of the contact medium.

Gap-Filling of Landsat 7 Imagery Using the Direct Sampling Method

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Gaohong Yin

2016-12-01

Full Text Available The failure of the Scan Line Corrector (SLC on Landsat 7 imposed systematic data gaps on retrieved imagery and removed the capacity to provide spatially continuous fields. While a number of methods have been developed to fill these gaps, most of the proposed techniques are only applicable over relatively homogeneous areas. When they are applied to heterogeneous landscapes, retrieving image features and elements can become challenging. Here we present a gap-filling approach that is based on the adoption of the Direct Sampling multiple-point geostatistical method. The method employs a conditional stochastic resampling of known areas in a training image to simulate unknown locations. The approach is assessed across a range of both homogeneous and heterogeneous regions. Simulation results show that for homogeneous areas, satisfactory results can be obtained by simply adopting non-gap locations in the target image as baseline training data. For heterogeneous landscapes, bivariate simulations using an auxiliary variable acquired at a different date provides more accurate results than univariate simulations, especially as land cover complexity increases. Apart from recovering spatially continuous fields, one of the key advantages of the Direct Sampling is the relatively straightforward implementation process that relies on relatively few parameters.

Rotational and translational stability of different methods for direct acromioclavicular ligament repair in anatomic acromioclavicular joint reconstruction.

Science.gov (United States)

Beitzel, Knut; Obopilwe, Elifho; Apostolakos, John; Cote, Mark P; Russell, Ryan P; Charette, Ryan; Singh, Hardeep; Arciero, Robert A; Imhoff, Andreas B; Mazzocca, Augustus D

2014-09-01

Many reconstructions of acromioclavicular (AC) joint dislocations have focused on the coracoclavicular (CC) ligaments and neglected the functional contribution of the AC ligaments and the deltotrapezial fascia. To compare the modifications of previously published methods for direct AC reconstruction in addition to a CC reconstruction. The hypothesis was that there would be significant differences within the variations of surgical reconstructions. Controlled laboratory study. A total of 24 cadaveric shoulders were tested with a servohydraulic testing system. Two digitizing cameras evaluated the 3-dimensional movement. All reconstructions were based on a CC reconstruction using 2 clavicle tunnels and a tendon graft. The following techniques were used to reconstruct the AC ligaments: a graft was shuttled underneath the AC joint back from anterior and again sutured to the acromial side of the joint (group 1), a graft was fixed intramedullary in the acromion and distal clavicle (group 2), a graft was passed over the acromion and into an acromial tunnel (group 3), and a FiberTape was fixed in a cruciate configuration (group 4). Anterior, posterior, and superior translation, as well as anterior and posterior rotation, were tested. Group 1 showed significantly less posterior translation compared with the 3 other groups (P < .05) but did not show significant differences compared with the native joint. Groups 3 and 4 demonstrated significantly more posterior translation than the native joint. Group 1 showed significantly less anterior translation compared with groups 2 and 3. Group 3 demonstrated significantly more anterior translation than the native joint. Group 1 demonstrated significantly less superior translation compared with the other groups and with the native joint. The AC joint of group 1 was pulled apart less compared with all other reconstructions. Only group 1 reproduced the native joint for the anterior rotation at the posterior marker. Group 4 showed

Comparing transformation methods for DNA microarray data

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Zwinderman Aeilko H

2004-06-01

Full Text Available Abstract Background When DNA microarray data are used for gene clustering, genotype/phenotype correlation studies, or tissue classification the signal intensities are usually transformed and normalized in several steps in order to improve comparability and signal/noise ratio. These steps may include subtraction of an estimated background signal, subtracting the reference signal, smoothing (to account for nonlinear measurement effects, and more. Different authors use different approaches, and it is generally not clear to users which method they should prefer. Results We used the ratio between biological variance and measurement variance (which is an F-like statistic as a quality measure for transformation methods, and we demonstrate a method for maximizing that variance ratio on real data. We explore a number of transformations issues, including Box-Cox transformation, baseline shift, partial subtraction of the log-reference signal and smoothing. It appears that the optimal choice of parameters for the transformation methods depends on the data. Further, the behavior of the variance ratio, under the null hypothesis of zero biological variance, appears to depend on the choice of parameters. Conclusions The use of replicates in microarray experiments is important. Adjustment for the null-hypothesis behavior of the variance ratio is critical to the selection of transformation method.

Comparative study of two commercially pure titanium casting methods

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Renata Cristina Silveira Rodrigues

2010-10-01

Full Text Available The interest in using titanium to fabricate removable partial denture (RPD frameworks has increased, but there are few studies evaluating the effects of casting methods on clasp behavior. OBJECTIVE: This study compared the occurrence of porosities and the retentive force of commercially pure titanium (CP Ti and cobalt-chromium (Co-Cr removable partial denture circumferential clasps cast by induction/centrifugation and plasma/vacuum-pressure. MATERIAL AND METHODS: 72 frameworks were cast from CP Ti (n=36 and Co-Cr alloy (n=36; control group. For each material, 18 frameworks were casted by electromagnetic induction and injected by centrifugation, whereas the other 18 were casted by plasma and injected by vacuum-pressure. For each casting method, three subgroups (n=6 were formed: 0.25 mm, 0.50 mm, and 0.75 mm undercuts. The specimens were radiographed and subjected to an insertion/removal test simulating 5 years of framework use. Data were analyzed by ANOVA and Tukey's to compare materials and cast methods (α=0.05. RESULTS: Three of 18 specimens of the induction/centrifugation group and 9 of 18 specimens of plasma/vacuum-pressure cast presented porosities, but only 1 and 7 specimens, respectively, were rejected for simulation test. For Co-Cr alloy, no defects were found. Comparing the casting methods, statistically significant differences (p<0.05 were observed only for the Co-Cr alloy with 0.25 mm and 0.50 mm undercuts. Significant differences were found for the 0.25 mm and 0.75 mm undercuts dependent on the material used. For the 0.50 mm undercut, significant differences were found when the materials were induction casted. CONCLUSION: Although both casting methods produced satisfactory CP Ti RPD frameworks, the occurrence of porosities was greater in the plasma/vacuum-pressure than in the induction/centrifugation method, the latter resulting in higher clasp rigidity, generating higher retention force values.

Comparative analysis of methods for detecting interacting loci.

Science.gov (United States)

Chen, Li; Yu, Guoqiang; Langefeld, Carl D; Miller, David J; Guy, Richard T; Raghuram, Jayaram; Yuan, Xiguo; Herrington, David M; Wang, Yue

2011-07-05

Interactions among genetic loci are believed to play an important role in disease risk. While many methods have been proposed for detecting such interactions, their relative performance remains largely unclear, mainly because different data sources, detection performance criteria, and experimental protocols were used in the papers introducing these methods and in subsequent studies. Moreover, there have been very few studies strictly focused on comparison of existing methods. Given the importance of detecting gene-gene and gene-environment interactions, a rigorous, comprehensive comparison of performance and limitations of available interaction detection methods is warranted. We report a comparison of eight representative methods, of which seven were specifically designed to detect interactions among single nucleotide polymorphisms (SNPs), with the last a popular main-effect testing method used as a baseline for performance evaluation. The selected methods, multifactor dimensionality reduction (MDR), full interaction model (FIM), information gain (IG), Bayesian epistasis association mapping (BEAM), SNP harvester (SH), maximum entropy conditional probability modeling (MECPM), logistic regression with an interaction term (LRIT), and logistic regression (LR) were compared on a large number of simulated data sets, each, consistent with complex disease models, embedding multiple sets of interacting SNPs, under different interaction models. The assessment criteria included several relevant detection power measures, family-wise type I error rate, and computational complexity. There are several important results from this study. First, while some SNPs in interactions with strong effects are successfully detected, most of the methods miss many interacting SNPs at an acceptable rate of false positives. In this study, the best-performing method was MECPM. Second, the statistical significance assessment criteria, used by some of the methods to control the type I error rate

Comparative analysis of methods for detecting interacting loci

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Yuan Xiguo

2011-07-01

Full Text Available Abstract Background Interactions among genetic loci are believed to play an important role in disease risk. While many methods have been proposed for detecting such interactions, their relative performance remains largely unclear, mainly because different data sources, detection performance criteria, and experimental protocols were used in the papers introducing these methods and in subsequent studies. Moreover, there have been very few studies strictly focused on comparison of existing methods. Given the importance of detecting gene-gene and gene-environment interactions, a rigorous, comprehensive comparison of performance and limitations of available interaction detection methods is warranted. Results We report a comparison of eight representative methods, of which seven were specifically designed to detect interactions among single nucleotide polymorphisms (SNPs, with the last a popular main-effect testing method used as a baseline for performance evaluation. The selected methods, multifactor dimensionality reduction (MDR, full interaction model (FIM, information gain (IG, Bayesian epistasis association mapping (BEAM, SNP harvester (SH, maximum entropy conditional probability modeling (MECPM, logistic regression with an interaction term (LRIT, and logistic regression (LR were compared on a large number of simulated data sets, each, consistent with complex disease models, embedding multiple sets of interacting SNPs, under different interaction models. The assessment criteria included several relevant detection power measures, family-wise type I error rate, and computational complexity. There are several important results from this study. First, while some SNPs in interactions with strong effects are successfully detected, most of the methods miss many interacting SNPs at an acceptable rate of false positives. In this study, the best-performing method was MECPM. Second, the statistical significance assessment criteria, used by some of the

Direct reconstruction of pharmacokinetic parameters in dynamic fluorescence molecular tomography by the augmented Lagrangian method

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Zhu, Dianwen; Zhang, Wei; Zhao, Yue; Li, Changqing

2016-03-01

Dynamic fluorescence molecular tomography (FMT) has the potential to quantify physiological or biochemical information, known as pharmacokinetic parameters, which are important for cancer detection, drug development and delivery etc. To image those parameters, there are indirect methods, which are easier to implement but tend to provide images with low signal-to-noise ratio, and direct methods, which model all the measurement noises together and are statistically more efficient. The direct reconstruction methods in dynamic FMT have attracted a lot of attention recently. However, the coupling of tomographic image reconstruction and nonlinearity of kinetic parameter estimation due to the compartment modeling has imposed a huge computational burden to the direct reconstruction of the kinetic parameters. In this paper, we propose to take advantage of both the direct and indirect reconstruction ideas through a variable splitting strategy under the augmented Lagrangian framework. Each iteration of the direct reconstruction is split into two steps: the dynamic FMT image reconstruction and the node-wise nonlinear least squares fitting of the pharmacokinetic parameter images. Through numerical simulation studies, we have found that the proposed algorithm can achieve good reconstruction results within a small amount of time. This will be the first step for a combined dynamic PET and FMT imaging in the future.

Applying Case-Based Method in Designing Self-Directed Online Instruction: A Formative Research Study

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Luo, Heng; Koszalka, Tiffany A.; Arnone, Marilyn P.; Choi, Ikseon

2018-01-01

This study investigated the case-based method (CBM) instructional-design theory and its application in designing self-directed online instruction. The purpose of this study was to validate and refine the theory for a self-directed online instruction context. Guided by formative research methodology, this study first developed an online tutorial…

Comparative analysis of clustering methods for gene expression time course data

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Ivan G. Costa

2004-01-01

Full Text Available This work performs a data driven comparative study of clustering methods used in the analysis of gene expression time courses (or time series. Five clustering methods found in the literature of gene expression analysis are compared: agglomerative hierarchical clustering, CLICK, dynamical clustering, k-means and self-organizing maps. In order to evaluate the methods, a k-fold cross-validation procedure adapted to unsupervised methods is applied. The accuracy of the results is assessed by the comparison of the partitions obtained in these experiments with gene annotation, such as protein function and series classification.

Increased recovery of touch DNA evidence using FTA paper compared to conventional collection methods.

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Kirgiz, Irina A; Calloway, Cassandra

2017-04-01

Tape lifting and FTA paper scraping methods were directly compared to traditional double swabbing for collecting touch DNA from car steering wheels (n = 70 cars). Touch DNA was collected from the left or right side of each steering wheel (randomized) using two sterile cotton swabs, while the other side was sampled using water-soluble tape or FTA paper cards. DNA was extracted and quantified in duplicate using qPCR. Quantifiable amounts of DNA were detected for 100% of the samples (n = 140) collected independent of the method. However, the DNA collection yield was dependent on the collection method. A statistically significant difference in DNA yield was observed between FTA scraping and double swabbing methods (p = 0.0051), with FTA paper collecting a two-fold higher amount. Statistical analysis showed no significant difference in DNA yields between the double swabbing and tape lifting techniques (p = 0.21). Based on the DNA concentration required for 1 ng input, 47% of the samples collected using FTA paper would be expected to yield a short tandem repeat (STR) profile compared to 30% and 23% using double swabbing or tape, respectively. Further, 55% and 77% of the samples collected using double swabbing or tape, respectively, did not yield a high enough DNA concentration for the 0.5 ng of DNA input recommended for conventional STR kits and would be expected to result in a partial or no profile compared to 35% of the samples collected using FTA paper. STR analysis was conducted for a subset of the higher concentrated samples to confirm that the DNA collected from the steering wheel was from the driver. 32 samples were selected with DNA amounts of at least 1 ng total DNA (100 pg/μl when concentrated if required). A mixed STR profile was observed for 26 samples (88%) and the last driver was the major DNA contributor for 29 samples (94%). For one sample, the last driver was the minor DNA contributor. A full STR profile of the last driver was observed for

Estimating the direction of innovative change based on theory an mixed methods

NARCIS (Netherlands)

Geurts, Petrus A.T.M.; Roosendaal, Hans E.

2001-01-01

In predicting the direction of innovative changethe question arises of the valid measurement ofyet unknown variables. We developed and applied aresearch method that combines qualitativeand quantitative elements in one interview formatand an analysis tool suitable for these data. Animportant

Performance Analysis and Experimental Validation of the Direct Strain Imaging Method

Science.gov (United States)

Athanasios Iliopoulos; John G. Michopoulos; John C. Hermanson

2013-01-01

Direct Strain Imaging accomplishes full field measurement of the strain tensor on the surface of a deforming body, by utilizing arbitrarily oriented engineering strain measurements originating from digital imaging. In this paper an evaluation of the method’s performance with respect to its operating parameter space is presented along with a preliminary...

Implementation of Electricity Business Competition Framework with Economic Dispatch Direct Method

Directory of Open Access Journals (Sweden)

Yusra Sabri

2012-12-01

Full Text Available Technically, electricity business under competition structure is more complex than that of vertically integrated one. The main prolems here are how to create an applicable competition framework and to solve electric calculations very quickly to obtain an optimal energi pricing, cost of losses, congestion and transportation costs by less than 15 minutes. This paper proposes a competition framework with the electric calculations, where a bilateral contract has been accommodated. Optimal energy price in the paper is calculated based on direct method of economic dispatch to obtain the result very quickly. The proposed method has been simulated to a 4-bus system. The simulation results show that the method works well and complies with the expectation. Therefore, electric power business under competition structure can be well realized by the proposed method.

Comparing Traditional and Crowdsourcing Methods for Pretesting Survey Questions

Directory of Open Access Journals (Sweden)

Jennifer Edgar

2016-10-01

Full Text Available Cognitive interviewing is a common method used to evaluate survey questions. This study compares traditional cognitive interviewing methods with crowdsourcing, or “tapping into the collective intelligence of the public to complete a task.” Crowdsourcing may provide researchers with access to a diverse pool of potential participants in a very timely and cost-efficient way. Exploratory work found that crowdsourcing participants, with self-administered data collection, may be a viable alternative, or addition, to traditional pretesting methods. Using three crowdsourcing designs (TryMyUI, Amazon Mechanical Turk, and Facebook, we compared the participant characteristics, costs, and quantity and quality of data with traditional laboratory-based cognitive interviews. Results suggest that crowdsourcing and self-administered protocols may be a viable way to collect survey pretesting information, as participants were able to complete the tasks and provide useful information; however, complex tasks may require the skills of an interviewer to administer unscripted probes.

Direct determination of calcium, sodium and potassium in fermented milk products

Directory of Open Access Journals (Sweden)

Kravić Snežana Ž.

2012-01-01

Full Text Available The aim of this study was the investigation of the possibilities of direct determination of calcium, sodium and potassium in the commercial and kombucha-based fermented milk products by flame photometry. Two procedures were used for sample preparation: simple dilution with water (direct method and extraction with mineral acid. Calcium, sodium and potassium levels determined after mentioned sample preparation methods were compared. The results showed that the differences between the values obtained for the different sample treatment were within the experimental error at the 95% confidence level. Compared to the method based on extraction with mineral acid, the direct method is efficient, faster, simpler, cheaper, and operates according to the principles of Green Chemistry. Consequently, the proposed method for the direct determination of calcium, sodium and potassium could be applied for the rapid routine analysis of the mineral content in the fermented dairy products. [Projekat Ministarstva nauke Republike Srbije, br. III 46009

Extraction and identification of cyclobutanones from irradiated cheese employing a rapid direct solvent extraction method.

Science.gov (United States)

Tewfik, Ihab

2008-01-01

2-Alkylcyclobutanones (cyclobutanones) are accepted as chemical markers for irradiated foods containing lipid. However, current extraction procedures (Soxhlet-florisil chromatography) for the isolation of these markers involve a long and tedious clean-up regime prior to gas chromatography-mass spectrophotometry identification. This paper outlines an alternative isolation and clean-up method for the extraction of cyclobutanones in irradiated Camembert cheese. The newly developed direct solvent extraction method enables the efficient screening of large numbers of food samples and is not as resource intensive as the BS EN 1785:1997 method. Direct solvent extraction appears to be a simple, robust method and has the added advantage of a considerably shorter extraction time for the analysis of foods containing lipid.

Comparing four methods to estimate usual intake distributions

NARCIS (Netherlands)

Souverein, O.W.; Dekkers, A.L.; Geelen, A.; Haubrock, J.; Vries, de J.H.M.; Ocke, M.C.; Harttig, U.; Boeing, H.; Veer, van 't P.

2011-01-01

Background/Objectives: The aim of this paper was to compare methods to estimate usual intake distributions of nutrients and foods. As ‘true’ usual intake distributions are not known in practice, the comparison was carried out through a simulation study, as well as empirically, by application to data

Transfer Pricing: Is the Comparable Uncontrolled Price Method the Best Method in all Cases?

Directory of Open Access Journals (Sweden)

Pranvera Dalloshi

2012-12-01

Full Text Available The transfer price scope is becoming a very important issue for all companies that comprise from different departments or have a network of branches. These companies are obliged to present the way of price determination for transactions that they have with their branches or other relevant members of their network. The establishment of the multinational companies that develop their activities in various countries is being increased. It has increased the need to supervise their transactions and approval of laws and administrative orders that do not leave space for misuses. The paper is focused in the response to the question if the Comparable Uncontrolled Price Method is the best method to be used in all cases. It is presented through a concrete example that shows how the price of a product determined through the Comparable Uncontrolled Price Method or market price has an impact to the profit of the mother company and other subsidiaries.

Mean protein evolutionary distance: a method for comparative protein evolution and its application.

Directory of Open Access Journals (Sweden)

Michael J Wise

Full Text Available Proteins are under tight evolutionary constraints, so if a protein changes it can only do so in ways that do not compromise its function. In addition, the proteins in an organism evolve at different rates. Leveraging the history of patristic distance methods, a new method for analysing comparative protein evolution, called Mean Protein Evolutionary Distance (MeaPED, measures differential resistance to evolutionary pressure across viral proteomes and is thereby able to point to the proteins' roles. Different species' proteomes can also be compared because the results, consistent across virus subtypes, concisely reflect the very different lifestyles of the viruses. The MeaPED method is here applied to influenza A virus, hepatitis C virus, human immunodeficiency virus (HIV, dengue virus, rotavirus A, polyomavirus BK and measles, which span the positive and negative single-stranded, doubled-stranded and reverse transcribing RNA viruses, and double-stranded DNA viruses. From this analysis, host interaction proteins including hemagglutinin (influenza, and viroporins agnoprotein (polyomavirus, p7 (hepatitis C and VPU (HIV emerge as evolutionary hot-spots. By contrast, RNA-directed RNA polymerase proteins including L (measles, PB1/PB2 (influenza and VP1 (rotavirus, and internal serine proteases such as NS3 (dengue and hepatitis C virus emerge as evolutionary cold-spots. The hot spot influenza hemagglutinin protein is contrasted with the related cold spot H protein from measles. It is proposed that evolutionary cold-spot proteins can become significant targets for second-line anti-viral therapeutics, in cases where front-line vaccines are not available or have become ineffective due to mutations in the hot-spot, generally more antigenically exposed proteins. The MeaPED package is available from www.pam1.bcs.uwa.edu.au/~michaelw/ftp/src/meaped.tar.gz.

Mean protein evolutionary distance: a method for comparative protein evolution and its application.

Science.gov (United States)

Wise, Michael J

2013-01-01

Proteins are under tight evolutionary constraints, so if a protein changes it can only do so in ways that do not compromise its function. In addition, the proteins in an organism evolve at different rates. Leveraging the history of patristic distance methods, a new method for analysing comparative protein evolution, called Mean Protein Evolutionary Distance (MeaPED), measures differential resistance to evolutionary pressure across viral proteomes and is thereby able to point to the proteins' roles. Different species' proteomes can also be compared because the results, consistent across virus subtypes, concisely reflect the very different lifestyles of the viruses. The MeaPED method is here applied to influenza A virus, hepatitis C virus, human immunodeficiency virus (HIV), dengue virus, rotavirus A, polyomavirus BK and measles, which span the positive and negative single-stranded, doubled-stranded and reverse transcribing RNA viruses, and double-stranded DNA viruses. From this analysis, host interaction proteins including hemagglutinin (influenza), and viroporins agnoprotein (polyomavirus), p7 (hepatitis C) and VPU (HIV) emerge as evolutionary hot-spots. By contrast, RNA-directed RNA polymerase proteins including L (measles), PB1/PB2 (influenza) and VP1 (rotavirus), and internal serine proteases such as NS3 (dengue and hepatitis C virus) emerge as evolutionary cold-spots. The hot spot influenza hemagglutinin protein is contrasted with the related cold spot H protein from measles. It is proposed that evolutionary cold-spot proteins can become significant targets for second-line anti-viral therapeutics, in cases where front-line vaccines are not available or have become ineffective due to mutations in the hot-spot, generally more antigenically exposed proteins. The MeaPED package is available from www.pam1.bcs.uwa.edu.au/~michaelw/ftp/src/meaped.tar.gz.

Bronchial histamine challenge. A combined interrupter-dosimeter method compared with a standard method

DEFF Research Database (Denmark)

Pavlovic, M; Holstein-Rathlou, N H; Madsen, F

1985-01-01

We compared the provocative concentration (PC) values obtained by two different methods of performing bronchial histamine challenge. One test was done on an APTA, an apparatus which allows simultaneous provocation with histamine and measurement of airway resistance (Rtot) by the interrupter metho...

Comparative study of durability test methods for pellets and briquettes

Energy Technology Data Exchange (ETDEWEB)

Temmerman, Michaeel; Rabier, Fabienne [Centre wallon de Recherches agronomiques (CRA-W), 146, chaussee de Namur, B-5030, Gembloux (Belgium); Jensen, Peter Daugbjerg [Forest and Landscape, The Royal Veterinary and Agricultural University, Rolighedsvej 23, DK-1958 Frederiksberg C (Denmark); Hartmann, Hans; Boehm, Thorsten [Technologie- und Foerderzentrum fuer Nachwachsende Rohstoffe-TFZ, Schulgasse 18, D-94315 Straubing (Germany)

2006-11-15

Different methods for the determination of the mechanical durability (DU) of pellets and briquettes were compared by international round robin tests including different laboratories. The DUs of five briquette and 26 pellet types were determined. For briquettes, different rotation numbers of a prototype tumbler and a calculated DU index are compared. For pellets testing, the study compares two standard methods, a tumbling device according to ASAE S 269.4, the Lignotester according to ONORM M 7135 and a second tumbling method with a prototype tumbler. For the tested methods, the repeatability, the reproducibility and the required minimum number of replications to achieve given accuracy levels were calculated. Additionally, this study evaluates the relation between DU and particle density. The results show for both pellets and briquettes, that the measured DU values and their variability are influenced by the applied method. Moreover, the variability of the results depend on the biofuel itself. For briquettes of DU above 90%, five replications lead to an accuracy of 2%, while 39 replications are needed to achieve an accuracy of 10%, when briquettes of DU below 90% are tested. For pellets, the tumbling device described by the ASAE standard allows to reach acceptable accuracy levels (1%) with a limited number of replications. Finally, for the tested pellets and briquettes no relation between DU and particle density was found. (author)

THE QUESTION OF HUMANITARIAN KNOWLEDGE: THE ESSENCE, MAIN DIRECTIONS AND METHODS

Directory of Open Access Journals (Sweden)

Anatoly V. Zavrazhin

2015-01-01

Full Text Available In the article the author emphasizes the role and importance of humanitarian knowledge not only in education, training future professionals, but in an objective, true evaluation of the events which occur today in the modern world. Reveals the methodological foundations, purpose, main directions and methods of humanitarian knowledge. Highlighted the special role in the Humanities.

Comparative Analysis of Kernel Methods for Statistical Shape Learning

National Research Council Canada - National Science Library

Rathi, Yogesh; Dambreville, Samuel; Tannenbaum, Allen

2006-01-01

.... In this work, we perform a comparative analysis of shape learning techniques such as linear PCA, kernel PCA, locally linear embedding and propose a new method, kernelized locally linear embedding...

Initialization method for triple-layer exchanged coupled direct overwrite MO disk (abstract)

Science.gov (United States)

Hatwar, T. K.; Genova, D. J.; Palumbo, A. C.

1993-05-01

Increasing efforts are directed at the development of direct overwrite (DOW) capability for achieving higher data transfer rate in MO media. DOW by light intensity modulation on a triple-layer medium has shown great promise. The three layers consist of memory, reference, and intermediate layers that are weakly coupled to each other. This scheme uses an auxiliary magnet to initialize the reference layer in one direction in addition to the bias magnet. DOW is between high and low power levels. High power aligns the magnetization of the coupled layers in one direction, and low power aligns the magnetization in the opposite direction. These high (Ph) and low (Pl) powers are generally widely separated. Since the focused writing beam has a Gaussian profile, when the center of the spot does the high power writing, the ``skirt'' is actually doing the low power writing. As a result, if the background is initialized in the direction of the high power written mark, a chain-like domain pattern is observed. This leads to high writing noise. We found that such writing noise can be eliminated by initializing the background in the direction of the low power written marks. We will discuss the spin structure in exchanged coupled triple-layer films and the DOW characteristics of the disk with the two different initialization methods.

Comparative Study of Three Data Assimilation Methods for Ice Sheet Model Initialisation

Science.gov (United States)

Mosbeux, Cyrille; Gillet-Chaulet, Fabien; Gagliardini, Olivier

2015-04-01

The current global warming has direct consequences on ice-sheet mass loss contributing to sea level rise. This loss is generally driven by an acceleration of some coastal outlet glaciers and reproducing these mechanisms is one of the major issues in ice-sheet and ice flow modelling. The construction of an initial state, as close as possible to current observations, is required as a prerequisite before producing any reliable projection of the evolution of ice-sheets. For this step, inverse methods are often used to infer badly known or unknown parameters. For instance, the adjoint inverse method has been implemented and applied with success by different authors in different ice flow models in order to infer the basal drag [ Schafer et al., 2012; Gillet-chauletet al., 2012; Morlighem et al., 2010]. Others data fields, such as ice surface and bedrock topography, are easily measurable with more or less uncertainty but only locally along tracks and interpolated on finer model grid. All these approximations lead to errors on the data elevation model and give rise to an ill-posed problem inducing non-physical anomalies in flux divergence [Seroussi et al, 2011]. A solution to dissipate these divergences of flux is to conduct a surface relaxation step at the expense of the accuracy of the modelled surface [Gillet-Chaulet et al., 2012]. Other solutions, based on the inversion of ice thickness and basal drag were proposed [Perego et al., 2014; Pralong & Gudmundsson, 2011]. In this study, we create a twin experiment to compare three different assimilation algorithms based on inverse methods and nudging to constrain the bedrock friction and the bedrock elevation: (i) cyclic inversion of friction parameter and bedrock topography using adjoint method, (ii) cycles coupling inversion of friction parameter using adjoint method and nudging of bedrock topography, (iii) one step inversion of both parameters with adjoint method. The three methods show a clear improvement in parameters

The peculiarities of the direct method usage in teaching speaking Foreign languages in Galicia and Bukovina (1890–1918

Directory of Open Access Journals (Sweden)

Bohdana Labinska

2012-12-01

Full Text Available The given article researches the peculiarities of the usage of the direct method in teaching foreign language speaking in Galicia and Bukovina (1890–1918. It analyses the preconditions of appearance of the direct method of teaching of foreign languages, the influence of contiguous sciences on the methodology of teaching of foreign languages. The peculiarities of realization of the direct method of teaching of foreign languages in Galicia and Bukovina is observed in the article. The methodology of teaching of foreign language speaking in the process of realization of the direct method in the west of Ukraine is described.

Treatment of deep caries lesions in adults: randomized clinical trials comparing stepwise vs. direct complete excavation, and direct pulp capping vs. partial pulpotomy

DEFF Research Database (Denmark)

Bjørndal, Lars; Reit, Claes; Bruun, Gitte Hoffmann

2010-01-01

Less invasive excavation methods have been suggested for deep caries lesions. We tested the effects of stepwise vs. direct complete excavation, 1 yr after the procedure had been carried out, in 314 adults (from six centres) who had received treatment of a tooth with deep caries. The teeth had car...

Development of direct dating methods of fault gouges: Deep drilling into Nojima Fault, Japan

Science.gov (United States)

Miyawaki, M.; Uchida, J. I.; Satsukawa, T.

2017-12-01

It is crucial to develop a direct dating method of fault gouges for the assessment of recent fault activity in terms of site evaluation for nuclear power plants. This method would be useful in regions without Late Pleistocene overlying sediments. In order to estimate the age of the latest fault slip event, it is necessary to use fault gouges which have experienced high frictional heating sufficient for age resetting. It is said that frictional heating is higher in deeper depths, because frictional heating generated by fault movement is determined depending on the shear stress. Therefore, we should determine the reliable depth of age resetting, as it is likely that fault gouges from the ground surface have been dated to be older than the actual age of the latest fault movement due to incomplete resetting. In this project, we target the Nojima fault which triggered the 1995 Kobe earthquake in Japan. Samples are collected from various depths (300-1,500m) by trenching and drilling to investigate age resetting conditions and depth using several methods including electron spin resonance (ESR) and optical stimulated luminescence (OSL), which are applicable to ages later than the Late Pleistocene. The preliminary results by the ESR method show approx. 1.1 Ma1) at the ground surface and 0.15-0.28 Ma2) at 388 m depth, respectively. These results indicate that samples from deeper depths preserve a younger age. In contrast, the OSL method dated approx. 2,200 yr1) at the ground surface. Although further consideration is still needed as there is a large margin of error, this result indicates that the age resetting depth of OSL is relatively shallow due to the high thermosensitivity of OSL compare to ESR. In the future, we plan to carry out further investigation for dating fault gouges from various depths up to approx. 1,500 m to verify the use of these direct dating methods.1) Kyoto University, 2017. FY27 Commissioned for the disaster presentation on nuclear facilities (Drilling

Calibration method based on direct radioactivity measurement for radioactive gas monitoring instruments

International Nuclear Information System (INIS)

Yoshida, Makoto; Ohi, Yoshihiro; Chida, Tohru; Wu, Youyang.

1993-01-01

A calibration method for radioactive gas monitoring instruments was studied. In the method, gaseous radioactivity standards were provided on the basis of the direct radioactivity measurement by the diffusion-in long proportional counter method (DLPC method). The radioactivity concentration of the gas mixture through a monitoring instrument was determined by sampling the known volume of the gas mixture into the proportional counter used for the DLPC method. Since oxygen in the gas mixture decreased the counting efficiency in a proportional counter, the influence on calibration was experimentally estimated. It was not serious and able to be easily corrected. By the present method, the relation between radioactivity concentration and ionization current was determined for a gas-flow ionization chamber with 1.5 l effective volume. It showed good agreement with the results in other works. (author)

Preconditioned alternating direction method of multipliers for inverse problems with constraints

International Nuclear Information System (INIS)

Jiao, Yuling; Jin, Qinian; Lu, Xiliang; Wang, Weijie

2017-01-01

We propose a preconditioned alternating direction method of multipliers (ADMM) to solve linear inverse problems in Hilbert spaces with constraints, where the feature of the sought solution under a linear transformation is captured by a possibly non-smooth convex function. During each iteration step, our method avoids solving large linear systems by choosing a suitable preconditioning operator. In case the data is given exactly, we prove the convergence of our preconditioned ADMM without assuming the existence of a Lagrange multiplier. In case the data is corrupted by noise, we propose a stopping rule using information on noise level and show that our preconditioned ADMM is a regularization method; we also propose a heuristic rule when the information on noise level is unavailable or unreliable and give its detailed analysis. Numerical examples are presented to test the performance of the proposed method. (paper)

Convergent validity between a discrete choice experiment and a direct, open-ended method: comparison of preferred attribute levels and willingness to pay estimates.

Science.gov (United States)

Marjon van der Pol; Shiell, Alan; Au, Flora; Johnston, David; Tough, Suzanne

2008-12-01

The Discrete Choice Experiment (DCE) has become increasingly popular as a method for eliciting patient or population preferences. If DCE estimates are to inform health policy, it is crucial that the answers they provide are valid. Convergent validity is tested in this paper by comparing the results of a DCE exercise with the answers obtained from direct, open-ended questions. The two methods are compared in terms of preferred attribute levels and willingness to pay (WTP) values. Face-to-face interviews were held with 292 women in Calgary, Canada. Similar values were found between the two methods with respect to preferred levels for two out of three of the attributes examined. The DCE predicted less well for levels outside the range than for levels inside the range reaffirming the importance of extensive piloting to ensure appropriate level range in DCEs. The mean WTP derived from the open-ended question was substantially lower than the mean derived from the DCE. However, the two sets of willingness to pay estimates were consistent with each other in that individuals who were willing to pay more in the open-ended question were also willing to pay more in the DCE. The difference in mean WTP values between the two approaches (direct versus DCE) demonstrates the importance of continuing research into the different biases present across elicitation methods.

Aircraft directional stability and vertical tail design: A review of semi-empirical methods

Science.gov (United States)

Ciliberti, Danilo; Della Vecchia, Pierluigi; Nicolosi, Fabrizio; De Marco, Agostino

2017-11-01

Aircraft directional stability and control are related to vertical tail design. The safety, performance, and flight qualities of an aircraft also depend on a correct empennage sizing. Specifically, the vertical tail is responsible for the aircraft yaw stability and control. If these characteristics are not well balanced, the entire aircraft design may fail. Stability and control are often evaluated, especially in the preliminary design phase, with semi-empirical methods, which are based on the results of experimental investigations performed in the past decades, and occasionally are merged with data provided by theoretical assumptions. This paper reviews the standard semi-empirical methods usually applied in the estimation of airplane directional stability derivatives in preliminary design, highlighting the advantages and drawbacks of these approaches that were developed from wind tunnel tests performed mainly on fighter airplane configurations of the first decades of the past century, and discussing their applicability on current transport aircraft configurations. Recent investigations made by the authors have shown the limit of these methods, proving the existence of aerodynamic interference effects in sideslip conditions which are not adequately considered in classical formulations. The article continues with a concise review of the numerical methods for aerodynamics and their applicability in aircraft design, highlighting how Reynolds-Averaged Navier-Stokes (RANS) solvers are well-suited to attain reliable results in attached flow conditions, with reasonable computational times. From the results of RANS simulations on a modular model of a representative regional turboprop airplane layout, the authors have developed a modern method to evaluate the vertical tail and fuselage contributions to aircraft directional stability. The investigation on the modular model has permitted an effective analysis of the aerodynamic interference effects by moving, changing, and

A comparative study of three different gene expression analysis methods.

Science.gov (United States)

Choe, Jae Young; Han, Hyung Soo; Lee, Seon Duk; Lee, Hanna; Lee, Dong Eun; Ahn, Jae Yun; Ryoo, Hyun Wook; Seo, Kang Suk; Kim, Jong Kun

2017-12-04

TNF-α regulates immune cells and acts as an endogenous pyrogen. Reverse transcription polymerase chain reaction (RT-PCR) is one of the most commonly used methods for gene expression analysis. Among the alternatives to PCR, loop-mediated isothermal amplification (LAMP) shows good potential in terms of specificity and sensitivity. However, few studies have compared RT-PCR and LAMP for human gene expression analysis. Therefore, in the present study, we compared one-step RT-PCR, two-step RT-LAMP and one-step RT-LAMP for human gene expression analysis. We compared three gene expression analysis methods using the human TNF-α gene as a biomarker from peripheral blood cells. Total RNA from the three selected febrile patients were subjected to the three different methods of gene expression analysis. In the comparison of three gene expression analysis methods, the detection limit of both one-step RT-PCR and one-step RT-LAMP were the same, while that of two-step RT-LAMP was inferior. One-step RT-LAMP takes less time, and the experimental result is easy to determine. One-step RT-LAMP is a potentially useful and complementary tool that is fast and reasonably sensitive. In addition, one-step RT-LAMP could be useful in environments lacking specialized equipment or expertise.

Comparative analysis of various methods for modelling permanent magnet machines

NARCIS (Netherlands)

Ramakrishnan, K.; Curti, M.; Zarko, D.; Mastinu, G.; Paulides, J.J.H.; Lomonova, E.A.

2017-01-01

In this paper, six different modelling methods for permanent magnet (PM) electric machines are compared in terms of their computational complexity and accuracy. The methods are based primarily on conformal mapping, mode matching, and harmonic modelling. In the case of conformal mapping, slotted air

Comparing concentration methods: parasitrap® versus Kato-Katz for ...

African Journals Online (AJOL)

Comparing concentration methods: parasitrap® versus Kato-Katz for studying the prevalence of Helminths in Bengo province, Angola. Clara Mirante, Isabel Clemente, Graciette Zambu, Catarina Alexandre, Teresa Ganga, Carlos Mayer, Miguel Brito ...

Direct methods of soil-structure interaction analysis for earthquake loadings (III)

Energy Technology Data Exchange (ETDEWEB)

Yoon, J B; Lee, S R; Kim, J M; Park, K R; Choi, J S; Oh, S B [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1995-06-15

In this study, direct methods for seismic analysis of soil-structure interaction system have been studied. A computer program 'KIESSI-QK' has been developed based on the finite element technique coupled with infinite element formulation. A substructuring method isolating the displacement solution of near field soil region was adopted. The computer program developed was verified using a free-field site response problem. The post-correlation analysis for the forced vibration tests after backfill of the Hualien LSST project has been carried out. The seismic analyses for the Hualien and Lotung LSST structures have been also performed utilizing the developed computer program 'KIESSI-QK'.

THE CHOICE OF METHODS OF TRAINING OF BACHELORS ON DIRECTION «CONSTRUCTION»

Directory of Open Access Journals (Sweden)

Ekaterina Vladimirovna Averyanova

2015-12-01

Full Text Available Purpose: based on the analysis of active learning methods to identify how, updated know-ledge in the study of special subjects in bachelors of direction of preparation «Building».Methodology: analysis of different active learning methods in the study of special disciplines.Results: analysis data of active learning methods has shown that the obtained a ba-chelor’s of knowledge has resulted in the creation of certain conditions.Practical implications: the results of the study will be of interest teachers of special disciplines of the specialty «Construction».

Safety and efficacy of direct oral anticoagulants compared to warfarin for extended treatment of venous thromboembolism -a systematic review and meta-analysis

DEFF Research Database (Denmark)

Sindet-Pedersen, Caroline; Pallisgaard, Jannik Langtved; Olesen, Jonas Bjerring

2015-01-01