Sample records for obtained results point

  1. Fixed Point Results for G-α-Contractive Maps with Application to Boundary Value Problems

    PubMed Central

    Roshan, Jamal Rezaei

    2014-01-01

    We unify the concepts of G-metric, metric-like, and b-metric to define new notion of generalized b-metric-like space and discuss its topological and structural properties. In addition, certain fixed point theorems for two classes of G-α-admissible contractive mappings in such spaces are obtained and some new fixed point results are derived in corresponding partially ordered space. Moreover, some examples and an application to the existence of a solution for the first-order periodic boundary value problem are provided here to illustrate the usability of the obtained results. PMID:24895655

  2. Fixed Point Results of Locally Contractive Mappings in Ordered Quasi-Partial Metric Spaces

    PubMed Central

    Arshad, Muhammad; Ahmad, Jamshaid

    2013-01-01

    Fixed point results for a self-map satisfying locally contractive conditions on a closed ball in an ordered 0-complete quasi-partial metric space have been established. Instead of monotone mapping, the notion of dominated mappings is applied. We have used weaker metric, weaker contractive conditions, and weaker restrictions to obtain unique fixed points. An example is given which shows that how this result can be used when the corresponding results cannot. Our results generalize, extend, and improve several well-known conventional results. PMID:24062629

  3. Leveraging finances for public health system improvement: results from the Turning Point initiative.

    PubMed

    Bekemeier, Betty; Riley, Catharine M; Berkowitz, Bobbie

    2007-01-01

    Reforming the public health infrastructure requires substantial system changes at the state level; state health agencies, however, often lack the resources and support for strategic planning and systemwide improvement. The Turning Point Initiative provided support for states to focus on large-scale system changes that resulted in increased funding for public health capacity and infrastructure development. Turning Point provides a test case for obtaining financial and institutional resources focused on systems change and infrastructure development-areas for which it has been historically difficult to obtain long-term support. The purpose of this exploratory, descriptive survey research was to enumerate the actual resources leveraged toward public health system improvement through the partnerships, planning, and implementation activities funded by the Robert Wood Johnson Foundation as a part of the Turning Point Initiative.

  4. The plasma filling factor of coronal bright points. II. Combined EIS and TRACE results

    NASA Astrophysics Data System (ADS)

    Dere, K. P.

    2009-04-01

    Aims: In a previous paper, the volumetric plasma filling factor of coronal bright points was determined from spectra obtained with the Extreme ultraviolet Imaging Spectrometer (EIS). The analysis of these data showed that the median plasma filling factor was 0.015. One interpretation of this result was that the small filling factor was consistent with a single coronal loop with a width of 1-2´´, somewhat below the apparent width. In this paper, higher spatial resolution observations with the Transition Region and Corona Explorer (TRACE) are used to test this interpretation. Methods: Rastered spectra of regions of the quiet Sun were recorded by the EIS during operations with the Hinode satellite. Many of these regions were simultaneously observed with TRACE. Calibrated intensities of Fe xii lines were obtained and images of the quiet corona were constructed from the EIS measurements. Emission measures were determined from the EIS spectra and geometrical widths of coronal bright points were obtained from the TRACE images. Electron densities were determined from density-sensitive line ratios measured with EIS. A comparison of the emission measure and bright point widths with the electron densities yielded the plasma filling factor. Results: The median electron density of coronal bright points is 3 × 109 cm-3 at a temperature of 1.6 × 106 K. The volumetric plasma filling factor of coronal bright points was found to vary from 3 × 10-3 to 0.3 with a median value of 0.04. Conclusions: The current set of EIS and TRACE coronal bright-point observations indicate the median value of their plasma filling factor is 0.04. This can be interpreted as evidence of a considerable subresolution structure in coronal bright points or as the result of a single completely filled plasma loop with widths on the order of 0.2-1.5´´ that has not been spatially resolved in these measurements.

  5. An Update on Phased Array Results Obtained on the GE Counter-Rotating Open Rotor Model

    NASA Technical Reports Server (NTRS)

    Podboy, Gary; Horvath, Csaba; Envia, Edmane

    2013-01-01

    Beamform maps have been generated from 1) simulated data generated by the LINPROP code and 2) actual experimental phased array data obtained on the GE Counter-rotating open rotor model. The beamform maps show that many of the tones in the experimental data come from their corresponding Mach radius. If the phased array points to the Mach radius associated with a tone then it is likely that the tone is a result of the loading and thickness noise on the blades. In this case, the phased array correctly points to where the noise is coming from and indicates the axial location of the loudest source in the image but not necessarily the correct vertical location. If the phased array does not point to the Mach radius associated with a tone then some mechanism other than loading and thickness noise may control the amplitude of the tone. In this case, the phased array may or may not point to the actual source. If the source is not rotating it is likely that the phased array points to the source. If the source is rotating it is likely that the phased array indicates the axial location of the loudest source but not necessarily the correct vertical location. These results indicate that you have to be careful in how you interpret phased array data obtained on an open rotor since they may show the tones coming from a location other than the source location. With a subsonic tip speed open rotor the tones can come form locations outboard of the blade tips. This has implications regarding noise shielding.

  6. Comparison of results obtained with various sensors used to measure fluctuating quantities in jets.

    NASA Technical Reports Server (NTRS)

    Parthasarathy, S. P.; Massier, P. F.; Cuffel, R. F.

    1973-01-01

    An experimental investigation has been conducted to compare the results obtained with six different instruments that sense fluctuating quantities in free jets. These sensors are typical of those that have recently been used by various investigators who are engaged in experimental studies of jet noise. Intensity distributions and two-point correlations with space separation and time delay were obtained. The static pressure, density, and velocity fluctuations are well correlated over the entire cross section of the jet and the cross-correlations persist for several jet diameters along the flow direction. The eddies appear to be flattened in the flow direction by a ratio of 0.4.

  7. GNSS Antenna Caused Near-Field Interference Effect in Precise Point Positioning Results

    NASA Astrophysics Data System (ADS)

    Dawidowicz, Karol; Baryła, Radosław

    2017-06-01

    Results of long-term static GNSS observation processing adjustment prove that the often assumed "averaging multipath effect due to extended observation periods" does not actually apply. It is instead visible a bias that falsifies the coordinate estimation. The comparisons between the height difference measured with a geometrical precise leveling and the height difference provided by GNSS clearly verify the impact of the near-field multipath effect. The aim of this paper is analysis the near-field interference effect with respect to the coordinate domain. We demonstrate that the way of antennas mounting during observation campaign (distance from nearest antennas) can cause visible changes in pseudo-kinematic precise point positioning results. GNSS measured height differences comparison revealed that bias of up to 3 mm can be noticed in Up component when some object (additional GNSS antenna) was placed in radiating near-field region of measuring antenna. Additionally, for both processing scenario (GPS and GPS/GLONASS) the scattering of results clearly increased when additional antenna crosses radiating near-field region of measuring antenna. It is especially true for big choke ring antennas. In short session (15, 30 min.) the standard deviation was about twice bigger in comparison to scenario without additional antenna. When we used typical surveying antennas (short near-field region radius) the effect is almost invisible. In this case it can be observed the standard deviation increase of about 20%. On the other hand we found that surveying antennas are generally characterized by lower accuracy than choke ring antennas. The standard deviation obtained on point with this type of antenna was bigger in all processing scenarios (in comparison to standard deviation obtained on point with choke ring antenna).

  8. Using Riemannian geometry to obtain new results on Dikin and Karmarkar methods

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Oliveira, P.; Joao, X.; Piaui, T.

    1994-12-31

    We are motivated by a 1990 Karmarkar paper on Riemannian geometry and Interior Point Methods. In this talk we show 3 results. (1) Karmarkar direction can be derived from the Dikin one. This is obtained by constructing a certain Z(x) representation of the null space of the unitary simplex (e, x) = 1; then the projective direction is the image under Z(x) of the affine-scaling one, when it is restricted to that simplex. (2) Second order information on Dikin and Karmarkar methods. We establish computable Hessians for each of the metrics corresponding to both directions, thus permitting the generation ofmore » {open_quotes}second order{close_quotes} methods. (3) Dikin and Karmarkar geodesic descent methods. For those directions, we make computable the theoretical Luenberger geodesic descent method, since we are able to explicit very accurate expressions of the corresponding geodesics. Convergence results are given.« less

  9. Comparison of Point Cloud Registration Algorithms for Better Result Assessment - Towards AN Open-Source Solution

    NASA Astrophysics Data System (ADS)

    Lachat, E.; Landes, T.; Grussenmeyer, P.

    2018-05-01

    Terrestrial and airborne laser scanning, photogrammetry and more generally 3D recording techniques are used in a wide range of applications. After recording several individual 3D datasets known in local systems, one of the first crucial processing steps is the registration of these data into a common reference frame. To perform such a 3D transformation, commercial and open source software as well as programs from the academic community are available. Due to some lacks in terms of computation transparency and quality assessment in these solutions, it has been decided to develop an open source algorithm which is presented in this paper. It is dedicated to the simultaneous registration of multiple point clouds as well as their georeferencing. The idea is to use this algorithm as a start point for further implementations, involving the possibility of combining 3D data from different sources. Parallel to the presentation of the global registration methodology which has been employed, the aim of this paper is to confront the results achieved this way with the above-mentioned existing solutions. For this purpose, first results obtained with the proposed algorithm to perform the global registration of ten laser scanning point clouds are presented. An analysis of the quality criteria delivered by two selected software used in this study and a reflexion about these criteria is also performed to complete the comparison of the obtained results. The final aim of this paper is to validate the current efficiency of the proposed method through these comparisons.

  10. Criteria required for an acceptable point-of-care test for UTI detection: Obtaining consensus using the Delphi technique

    PubMed Central

    Kearney, Paddy; Stafford, Bob; Gormley, Gerard J.; Crockard, Martin A.; Gilpin, Deirdre F.

    2018-01-01

    Background Urinary Tract Infections (UTIs) are common bacterial infections, second only to respiratory tract infections and particularly prevalent within primary care. Conventional detection of UTIs is culture, however, return of results can take between 24 and 72 hours. The introduction of a point of care (POC) test would allow for more timely identification of UTIs, facilitating improved, targeted treatment. This study aimed to obtain consensus on the criteria required for a POC UTI test, to meet patient need within primary care. Methods Criteria for consideration were compiled by the research team. These criteria were validated through a two-round Delphi process, utilising an expert panel of healthcare professionals from across Europe and United States of America. Using web-based questionnaires, panellists recorded their level of agreement with each criterion based on a 5-point Likert Scale, with space for comments. Using median response, interquartile range and comments provided, criteria were accepted/rejected/revised depending on pre-agreed cut-off scores. Results The first round questionnaire presented thirty-three criteria to the panel, of which 22 were accepted. Consensus was not achieved for the remaining 11 criteria. Following response review, one criterion was removed, while after revision, the remaining 10 criteria entered the second round. Of these, four were subsequently accepted, resulting in 26 criteria considered appropriate for a POC test to detect urinary infections. Conclusion This study generated an approved set of criteria for a POC test to detect urinary infections. Criteria acceptance and comments provided by the healthcare professionals also supports the development of a multiplex point of care UTI test. PMID:29879161

  11. Criteria required for an acceptable point-of-care test for UTI detection: Obtaining consensus using the Delphi technique.

    PubMed

    Weir, Nichola-Jane M; Pattison, Sally H; Kearney, Paddy; Stafford, Bob; Gormley, Gerard J; Crockard, Martin A; Gilpin, Deirdre F; Tunney, Michael M; Hughes, Carmel M

    2018-01-01

    Urinary Tract Infections (UTIs) are common bacterial infections, second only to respiratory tract infections and particularly prevalent within primary care. Conventional detection of UTIs is culture, however, return of results can take between 24 and 72 hours. The introduction of a point of care (POC) test would allow for more timely identification of UTIs, facilitating improved, targeted treatment. This study aimed to obtain consensus on the criteria required for a POC UTI test, to meet patient need within primary care. Criteria for consideration were compiled by the research team. These criteria were validated through a two-round Delphi process, utilising an expert panel of healthcare professionals from across Europe and United States of America. Using web-based questionnaires, panellists recorded their level of agreement with each criterion based on a 5-point Likert Scale, with space for comments. Using median response, interquartile range and comments provided, criteria were accepted/rejected/revised depending on pre-agreed cut-off scores. The first round questionnaire presented thirty-three criteria to the panel, of which 22 were accepted. Consensus was not achieved for the remaining 11 criteria. Following response review, one criterion was removed, while after revision, the remaining 10 criteria entered the second round. Of these, four were subsequently accepted, resulting in 26 criteria considered appropriate for a POC test to detect urinary infections. This study generated an approved set of criteria for a POC test to detect urinary infections. Criteria acceptance and comments provided by the healthcare professionals also supports the development of a multiplex point of care UTI test.

  12. Some results regarding stability of photovoltaic maximum-power-point tracking dc-dc converters

    NASA Astrophysics Data System (ADS)

    Schaefer, John F.

    An analytical investigation of a class of photovoltaic (PV) maximum-power-point tracking dc-dc converters has yielded basic results relative to the stability of such devices. Necessary and sufficient conditions for stable operation are derived, and design tools are given. Specific results have been obtained for arbitrary PV arrays driving converters powering resistive loads and batteries. The analytical techniques are applicable to inverters, also. Portions of the theoretical results have been verified in operational devices: a 1500 watt unit has driven a 1-horsepower, 90-volt dc motor powering a water pump jack for over one year. Prior to modification shortly after initial installation, the unit exhibited instability at low levels of irradiance, as predicted by the theory. Two examples are provided.

  13. Comparison of 3D point clouds obtained by photogrammetric UAVs and TLS to determine the attitude of dolerite outcrops discontinuities.

    NASA Astrophysics Data System (ADS)

    Duarte, João; Gonçalves, Gil; Duarte, Diogo; Figueiredo, Fernando; Mira, Maria

    2015-04-01

    Photogrammetric Unmanned Aerial Vehicles (UAVs) and Terrestrial Laser Scanners (TLS) are two emerging technologies that allows the production of dense 3D point clouds of the sensed topographic surfaces. Although image-based stereo-photogrammetric point clouds could not, in general, compete on geometric quality over TLS point clouds, fully automated mapping solutions based on ultra-light UAVs (or drones) have recently become commercially available at very reasonable accuracy and cost for engineering and geological applications. The purpose of this paper is to compare the two point clouds generated by these two technologies, in order to automatize the manual process tasks commonly used to detect and represent the attitude of discontinuities (Stereographic projection: Schmidt net - Equal area). To avoid the difficulties of access and guarantee the data survey security conditions, this fundamental step in all geological/geotechnical studies, applied to the extractive industry and engineering works, has to be replaced by a more expeditious and reliable methodology. This methodology will allow, in a more actuated clear way, give answers to the needs of evaluation of rock masses, by mapping the structures present, which will reduce considerably the associated risks (investment, structures dimensioning, security, etc.). A case study of a dolerite outcrop locate in the center of Portugal (the dolerite outcrop is situated in the volcanic complex of Serra de Todo-o-Mundo, Casais Gaiola, intruded in Jurassic sandstones) will be used to assess this methodology. The results obtained show that the 3D point cloud produced by the Photogrammetric UAV platform has the appropriate geometric quality for extracting the parameters that define the discontinuities of the dolerite outcrops. Although, they are comparable to the manual extracted parameters, their quality is inferior to parameters extracted from the TLS point cloud.

  14. Comparison of Anaerobic Susceptibility Results Obtained by Different Methods

    PubMed Central

    Rosenblatt, J. E.; Murray, P. R.; Sonnenwirth, A. C.; Joyce, J. L.

    1979-01-01

    Susceptibility tests using 7 antimicrobial agents (carbenicillin, chloramphenicol, clindamycin, penicillin, cephalothin, metronidazole, and tetracycline) were run against 35 anaerobes including Bacteroides fragilis (17), other gram-negative bacilli (7), clostridia (5), peptococci (4), and eubacteria (2). Results in triplicate obtained by the microbroth dilution method and the aerobic modification of the broth disk method were compared with those obtained with an agar dilution method using Wilkins-Chalgren agar. Media used in the microbroth dilution method included Wilkins-Chalgren broth, brain heart infusion broth, brucella broth, tryptic soy broth, thioglycolate broth, and Schaedler's broth. A result differing by more than one dilution from the Wilkins-Chalgren agar result was considered a discrepancy, and when there was a change in susceptibility status this was termed a significant discrepancy. The microbroth dilution method using Wilkins-Chalgren broth and thioglycolate broth produced the fewest total discrepancies (22 and 24, respectively), and Wilkins-Chalgren broth, thioglycolate, and Schaedler's broth had the fewest significant discrepancies (6, 5, and 5, respectively). With the broth disk method, there were 15 significant discrepancies, although half of these were with tetracycline, which was the antimicrobial agent associated with the highest number of significant discrepancies (33), considering all of the test methods and media. PMID:464560

  15. WHO Melting-Point Reference Substances

    PubMed Central

    Bervenmark, H.; Diding, N. Å.; Öhrner, B.

    1963-01-01

    Batches of 13 highly purified chemicals, intended for use as reference substances in the calibration of apparatus for melting-point determinations, have been subjected to a collaborative assay by 15 laboratories in 13 countries. All the laboratories performed melting-point determinations by the capillary methods described in the proposed text for the second edition of the Pharmacopoea Internationalis and some, in addition, carried out determinations by the microscope hot stage (Kofler) method, using both the “going-through” and the “equilibrium” technique. Statistical analysis of the data obtained by the capillary method showed that the within-laboratory variation was small and that the between-laboratory variation, though constituting the greatest part of the whole variance, was not such as to warrant the exclusion of any laboratory from the evaluation of the results. The average values of the melting-points obtained by the laboratories can therefore be used as constants for the substances in question, which have accordingly been established as WHO Melting-Point Reference Substances and included in the WHO collection of authentic chemical substances. As to the microscope hot stage method, analysis of the results indicated that the values obtained by the “going-through” technique did not differ significantly from those obtained by the capillary method, but the values obtained by the “equilibrium” technique were mostly significantly lower. PMID:20604137

  16. Experimental results for the rapid determination of the freezing point of fuels

    NASA Technical Reports Server (NTRS)

    Mathiprakasam, B.

    1984-01-01

    Two methods for the rapid determination of the freezing point of fuels were investigated: an optical method, which detected the change in light transmission from the disappearance of solid particles in the melted fuel; and a differential thermal analysis (DTA) method, which sensed the latent heat of fusion. A laboratory apparatus was fabricated to test the two methods. Cooling was done by thermoelectric modules using an ice-water bath as a heat sink. The DTA method was later modified to eliminate the reference fuel. The data from the sample were digitized and a point of inflection, which corresponds to the ASTM D-2386 freezing point (final melting point), was identified from the derivative. The apparatus was modifified to cool the fuel to -60 C and controls were added for maintaining constant cooling rate, rewarming rate, and hold time at minimum temperature. A parametric series of tests were run for twelve fuels with freezing points from -10 C to -50 C, varying cooling rate, rewarming rate, and hold time. Based on the results, an optimum test procedure was established. The results showed good agreement with ASTM D-2386 freezing point and differential scanning calorimetry results.

  17. On dermatomes, meridians and points: results of a quasiexperimental study.

    PubMed

    Sánchez-Araujo, Max; Luckert-Barela, Ana J; Sánchez, Nathalia; Torres, Juan; Conde, Jesus Eloy

    2014-02-01

    Traditional Chinese medicine (TCM) meridians and points run vertically, reflecting their function in the Zhang-Fu system (meridian pattern). However, the trunk's spinal nerves show a traverse orientation, or a 'horizontal pattern'. The aim of the present work was to evaluate, via a cognitive quasiexperiment, whether the clinical indications of the points on the trunk are associated with their meridian function or with their innervation and visceral-somatic connection. The points in each dermatome of the trunk were considered crosswise, regardless of their meridians. The clinical indications for each point were differentiated into two mutually exclusive categories: (a) vertical distribution effect (VDE) or 'meridian pattern', when indications were quite different regarding the indications for the other points on the dermatome; and (b) transverse distribution effects (TDE) or 'horizontal pattern', represented by mainly local or segmental indications except for Shu-Mu points. After observing that the proportions between both categories often exceeded 60% in pilot samples, 60% was adopted as the reference value. A total of 22 dermatomes accommodated 148 points with 809 indications, of which 189 indications (23.4%) exhibited VDE features, whereas 620 (76.6%) exhibited TDE features. A TDE/VDE ratio of 3 : 1 implies that the clinical indications for the points of any dermatome on the torso are similar, regardless of their meridians, and suggests that most of the indications for trunk points involve a 'horizontal pattern' due to their neurobiological nature. These findings may help in understanding acupuncture's neurobiology and clarify some confusing results of clinical research, for example, excluding sham acupuncture as an inert intervention for future clinical trials.

  18. Obtaining Global Picture From Single Point Observations by Combining Data Assimilation and Machine Learning Tools

    NASA Astrophysics Data System (ADS)

    Shprits, Y.; Zhelavskaya, I. S.; Kellerman, A. C.; Spasojevic, M.; Kondrashov, D. A.; Ghil, M.; Aseev, N.; Castillo Tibocha, A. M.; Cervantes Villa, J. S.; Kletzing, C.; Kurth, W. S.

    2017-12-01

    Increasing volume of satellite measurements requires deployment of new tools that can utilize such vast amount of data. Satellite measurements are usually limited to a single location in space, which complicates the data analysis geared towards reproducing the global state of the space environment. In this study we show how measurements can be combined by means of data assimilation and how machine learning can help analyze large amounts of data and can help develop global models that are trained on single point measurement. Data Assimilation: Manual analysis of the satellite measurements is a challenging task, while automated analysis is complicated by the fact that measurements are given at various locations in space, have different instrumental errors, and often vary by orders of magnitude. We show results of the long term reanalysis of radiation belt measurements along with fully operational real-time predictions using data assimilative VERB code. Machine Learning: We present application of the machine learning tools for the analysis of NASA Van Allen Probes upper-hybrid frequency measurements. Using the obtained data set we train a new global predictive neural network. The results for the Van Allen Probes based neural network are compared with historical IMAGE satellite observations. We also show examples of predictions of geomagnetic indices using neural networks. Combination of machine learning and data assimilation: We discuss how data assimilation tools and machine learning tools can be combine so that physics-based insight into the dynamics of the particular system can be combined with empirical knowledge of it's non-linear behavior.

  19. New high-definition thickness data obtained at tropical glaciers: preliminary results from Antisana volcano (Ecuador) using GPR prospection

    NASA Astrophysics Data System (ADS)

    Zapata, Camilo; Andrade, Daniel; Córdova, Jorge; Maisincho, Luis; Carvajal, Juan; Calispa, Marlon; Villacís, Marcos

    2014-05-01

    The study of tropical glaciers has been a significant contribution to the understanding of glacier dynamics and climate change. Much of the data and results have been obtained by analyzing plan-view images obtained by air- and space-borne sensors, as well as depth data obtained by diverse methodologies at selected points on the glacier surface. However, the measurement of glacier thicknesses has remained an elusive task in tropical glaciers, often located in rough terrains where the application of geophysical surveys (i.e. seismic surveys) requires logistics sometimes hardly justified by the amount of obtained data. In the case of Ecuador, however, where most glaciers have developed on active volcanoes and represent sources/reservoirs of fresh water, the precise knowledge of such information is fundamental for scientific research but also in order to better assess key aspects for the society. The relatively recent but fast development of the GPR technology has helped to obtain new highdefinition thickness data at Antisana volcano that will be used to: 1) better understand the dynamics and fate of tropical glaciers; 2) better estimate the amount of fresh water stored in the glaciers; 3) better assess the hazards associated with the sudden widespread melting of glaciers during volcanic eruptions. The measurements have been obtained at glaciers 12 and 15 of Antisana volcano, with the help of a commercial GPR equipped with a 25 MHz antenna. A total of 30 transects have been obtained, covering a distance of more than 3 km, from the glacier ablation zone, located at ~ 4600 masl, up to the level of 5200 masl. The preliminary results show a positive correlation between altitude and glacier thickness, with maximum and minimum calculated values reaching up to 80 m, and down to 15 m, respectively. The experience gained at Antisana volcano will be used to prepare a more widespread GPR survey in the glaciers of Cotopaxi volcano, whose implications in terms of volcanic hazards

  20. Point Cloud Analysis for Uav-Borne Laser Scanning with Horizontally and Vertically Oriented Line Scanners - Concept and First Results

    NASA Astrophysics Data System (ADS)

    Weinmann, M.; Müller, M. S.; Hillemann, M.; Reydel, N.; Hinz, S.; Jutzi, B.

    2017-08-01

    In this paper, we focus on UAV-borne laser scanning with the objective of densely sampling object surfaces in the local surrounding of the UAV. In this regard, using a line scanner which scans along the vertical direction and perpendicular to the flight direction results in a point cloud with low point density if the UAV moves fast. Using a line scanner which scans along the horizontal direction only delivers data corresponding to the altitude of the UAV and thus a low scene coverage. For these reasons, we present a concept and a system for UAV-borne laser scanning using multiple line scanners. Our system consists of a quadcopter equipped with horizontally and vertically oriented line scanners. We demonstrate the capabilities of our system by presenting first results obtained for a flight within an outdoor scene. Thereby, we use a downsampling of the original point cloud and different neighborhood types to extract fundamental geometric features which in turn can be used for scene interpretation with respect to linear, planar or volumetric structures.

  1. Obtaining an equivalent beam

    NASA Technical Reports Server (NTRS)

    Butler, Thomas G.

    1990-01-01

    In modeling a complex structure the researcher was faced with a component that would have logical appeal if it were modeled as a beam. The structure was a mast of a robot controlled gantry crane. The structure up to this point already had a large number of degrees of freedom, so the idea of conserving grid points by modeling the mast as a beam was attractive. The researcher decided to make a separate problem of of the mast and model it in three dimensions with plates, then extract the equivalent beam properties by setting up the loading to simulate beam-like deformation and constraints. The results could then be used to represent the mast as a beam in the full model. A comparison was made of properties derived from models of different constraints versus manual calculations. The researcher shows that the three-dimensional model is ineffective in trying to conform to the requirements of an equivalent beam representation. If a full 3-D plate model were used in the complete representation of the crane structure, good results would be obtained. Since the attempt is to economize on the size of the model, a better way to achieve the same results is to use substructuring and condense the mast to equivalent end boundary and intermediate mass points.

  2. Multiview point clouds denoising based on interference elimination

    NASA Astrophysics Data System (ADS)

    Hu, Yang; Wu, Qian; Wang, Le; Jiang, Huanyu

    2018-03-01

    Newly emerging low-cost depth sensors offer huge potentials for three-dimensional (3-D) modeling, but existing high noise restricts these sensors from obtaining accurate results. Thus, we proposed a method for denoising registered multiview point clouds with high noise to solve that problem. The proposed method is aimed at fully using redundant information to eliminate the interferences among point clouds of different views based on an iterative procedure. In each iteration, noisy points are either deleted or moved to their weighted average targets in accordance with two cases. Simulated data and practical data captured by a Kinect v2 sensor were tested in experiments qualitatively and quantitatively. Results showed that the proposed method can effectively reduce noise and recover local features from highly noisy multiview point clouds with good robustness, compared to truncated signed distance function and moving least squares (MLS). Moreover, the resulting low-noise point clouds can be further smoothed by the MLS to achieve improved results. This study provides the feasibility of obtaining fine 3-D models with high-noise devices, especially for depth sensors, such as Kinect.

  3. Experiment Comparison between Engineering Acid Dew Point and Thermodynamic Acid Dew Point

    NASA Astrophysics Data System (ADS)

    Song, Jinghui; Yuan, Hui; Deng, Jianhua

    2018-06-01

    in order to realize the accurate prediction of acid dew point, a set of measurement system of acid dew point for the flue gas flue gas in the tail of the boiler was designed and built, And measured at the outlet of an air preheater of a power plant of 1 000 MW, The results show that: Under the same conditions, with the test temperature decreases, Nu of heat transfer tubes, fouling and corrosion of pipe wall and corrosion pieces gradually deepened. Then, the measured acid dew point is compared with the acid dew point obtained by using the existing empirical formula under the same coal type. The dew point of engineering acid is usually about 40 ° lower than the dew point of thermodynamic acid because of the coupling effect of fouling on the acid liquid, which can better reflect the actual operation of flue gas in engineering and has certain theoretical guidance for the design and operation of deep waste heat utilization system significance.

  4. A regularity result for fixed points, with applications to linear response

    NASA Astrophysics Data System (ADS)

    Sedro, Julien

    2018-04-01

    In this paper, we show a series of abstract results on fixed point regularity with respect to a parameter. They are based on a Taylor development taking into account a loss of regularity phenomenon, typically occurring for composition operators acting on spaces of functions with finite regularity. We generalize this approach to higher order differentiability, through the notion of an n-graded family. We then give applications to the fixed point of a nonlinear map, and to linear response in the context of (uniformly) expanding dynamics (theorem 3 and corollary 2), in the spirit of Gouëzel-Liverani.

  5. Whole body pointing movements in transient microgravity: preliminary results.

    PubMed

    Tagliabue, Michele; Pedrocchi, Alessandra; Gower, Valerio; Ferrigno, Giancarlo; Pozzo, Thierry

    2004-07-01

    The aim of the present study is a better comprehension of strategies of motor coordination during complex movements. In this field of research microgravity represent a unique experimental condition for the investigation of the role of equilibrium control in movement planning. Namely, here we focus on two important issues: the centre of mass control and the endpoint trajectory. Preliminary results of the center of mass position and the finger path curvature during pointing movements performed under normal and transient microgravity conditions are presented.

  6. First Neutrino Point-Source Results from the 22 String Icecube Detector

    NASA Astrophysics Data System (ADS)

    Abbasi, R.; Abdou, Y.; Ackermann, M.; Adams, J.; Aguilar, J.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bissok, M.; Blaufuss, E.; Boersma, D. J.; Bohm, C.; Bolmont, J.; Böser, S.; Botner, O.; Bradley, L.; Braun, J.; Breder, D.; Castermans, T.; Chirkin, D.; Christy, B.; Clem, J.; Cohen, S.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Day, C. T.; De Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; De Young, T.; Diaz-Velez, J. C.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Edwards, W. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Ganugapati, R.; Gerhardt, L.; Gladstone, L.; Goldschmidt, A.; Goodman, J. A.; Gozzini, R.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gunasingha, R. M.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Hasegawa, Y.; Heise, J.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Imlay, R. L.; Inaba, M.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kelley, J. L.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Klepser, S.; Knops, S.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Lauer, R.; Leich, H.; Lennarz, D.; Lucke, A.; Lundberg, J.; Lünemann, J.; Madsen, J.; Majumdar, P.; Maruyama, R.; Mase, K.; Matis, H. S.; McParland, C. P.; Meagher, K.; Merck, M.; Mészáros, P.; Middell, E.; Milke, N.; Miyamoto, H.; Mohr, A.; Montaruli, T.; Morse, R.; Movit, S. M.; Münich, K.; Nahnhauer, R.; Nam, J. W.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; Ono, M.; Panknin, S.; Patton, S.; Pérez de los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Pohl, A. C.; Porrata, R.; Potthoff, N.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Rutledge, D.; Ryckbosch, D.; Sander, H.-G.; Sarkar, S.; Satalecka, K.; Schlenstedt, S.; Schmidt, T.; Schneider, D.; Schukraft, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoufer, M. C.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sulanke, K.-H.; Sullivan, G. W.; Swillens, Q.; Taboada, I.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Terranova, C.; Tilav, S.; Tluczykont, M.; Toale, P. A.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; Van Overloop, A.; Voigt, B.; Walck, C.; Waldenmaier, T.; Walter, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebusch, C. H.; Wiedemann, A.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, X. W.; Yodh, G.; Ice Cube Collaboration

    2009-08-01

    We present new results of searches for neutrino point sources in the northern sky, using data recorded in 2007-2008 with 22 strings of the IceCube detector (approximately one-fourth of the planned total) and 275.7 days of live time. The final sample of 5114 neutrino candidate events agrees well with the expected background of atmospheric muon neutrinos and a small component of atmospheric muons. No evidence of a point source is found, with the most significant excess of events in the sky at 2.2σ after accounting for all trials. The average upper limit over the northern sky for point sources of muon-neutrinos with E -2 spectrum is E^{2} Φ_{ν_{μ}} < 1.4 × 10^{-11} TeV cm^{-2} s^{-1}, in the energy range from 3 TeV to 3 PeV, improving the previous best average upper limit by the AMANDA-II detector by a factor of 2.

  7. Automatic markerless registration of point clouds with semantic-keypoint-based 4-points congruent sets

    NASA Astrophysics Data System (ADS)

    Ge, Xuming

    2017-08-01

    The coarse registration of point clouds from urban building scenes has become a key topic in applications of terrestrial laser scanning technology. Sampling-based algorithms in the random sample consensus (RANSAC) model have emerged as mainstream solutions to address coarse registration problems. In this paper, we propose a novel combined solution to automatically align two markerless point clouds from building scenes. Firstly, the method segments non-ground points from ground points. Secondly, the proposed method detects feature points from each cross section and then obtains semantic keypoints by connecting feature points with specific rules. Finally, the detected semantic keypoints from two point clouds act as inputs to a modified 4PCS algorithm. Examples are presented and the results compared with those of K-4PCS to demonstrate the main contributions of the proposed method, which are the extension of the original 4PCS to handle heavy datasets and the use of semantic keypoints to improve K-4PCS in relation to registration accuracy and computational efficiency.

  8. Registration algorithm of point clouds based on multiscale normal features

    NASA Astrophysics Data System (ADS)

    Lu, Jun; Peng, Zhongtao; Su, Hang; Xia, GuiHua

    2015-01-01

    The point cloud registration technology for obtaining a three-dimensional digital model is widely applied in many areas. To improve the accuracy and speed of point cloud registration, a registration method based on multiscale normal vectors is proposed. The proposed registration method mainly includes three parts: the selection of key points, the calculation of feature descriptors, and the determining and optimization of correspondences. First, key points are selected from the point cloud based on the changes of magnitude of multiscale curvatures obtained by using principal components analysis. Then the feature descriptor of each key point is proposed, which consists of 21 elements based on multiscale normal vectors and curvatures. The correspondences in a pair of two point clouds are determined according to the descriptor's similarity of key points in the source point cloud and target point cloud. Correspondences are optimized by using a random sampling consistency algorithm and clustering technology. Finally, singular value decomposition is applied to optimized correspondences so that the rigid transformation matrix between two point clouds is obtained. Experimental results show that the proposed point cloud registration algorithm has a faster calculation speed, higher registration accuracy, and better antinoise performance.

  9. Agreement between the 'point of care' tests for microalbuminuria and HbA1c performed in mexican family medicine units and the results of standard laboratory tests.

    PubMed

    Valdez-González, Leticia A; Méndez-Padrón, Araceli; Gómez-Díaz, Rita A; Valladares-Salgado, Adán; Sánchez-Becerra, Martha Catalina; Mondragón-González, Rafael; Hernández-Rubí, Jaime; González-Hermosillo, Arturo; Cruz, Miguel; Borja, Víctor; Wacher, Niels H

    The albumin-creatinine ratio is considered an indicator of microalbuminuria, precursor to chronic kidney disease, while HbA1c is used to measure glycemic control. Given the prevalence of diabetes-related nephropathy, spot testing of albumin has long been recommended as a preventative measure, for the timely detection of microalbuminuria. However, many countries do not have this testing available in primary care, and sometimes not even in second- and third-level care. The objective of this study was to compare agreement of the microalbuminuria and HbA1c results obtained in the laboratory with 'gold standard' techniques, with those obtained on site with a 'Point of Care' DCA Vantage™ device by Siemens. Results for the albumin-creatinine ratio and HbA1c from the Siemens DCA Vantage™ point of care device were compared with those from standard laboratory tests in 25 family medicine units in Mexico City and Toluca, State of Mexico, in patients diagnosed with type-2 diabetes. Agreement between the albumin values of the 2 tests was 0.745 (CI 95% 0.655-0.812). Agreement between the two measurement techniques for HbA1c was 0.970 (CI 95% 0.966-0.973). The results obtained were sufficiently comparative (R i = 0.74 for albumin-creatinine ratio and R i  = 0.97 for HbA1c) to justify the use of the point of care device. Given the high agreement between the point of care device and laboratory tests, this device could be used to identify chronic kidney disease and glycemic control for more adequate treatment in patients with diabetes, especially in remote areas.

  10. Investigations of Multiple Swirl-Venturi Fuel Injector Concepts: Recent Experimental Optical Measurement Results for 1-Point, 7-Point, and 9-Point Configurations

    NASA Technical Reports Server (NTRS)

    Hicks, Yolanda R.; Anderson, Robert C.; Tedder, Sarah A.; Tacina, Kathleen M.

    2015-01-01

    This paper presents results obtained during testing in optically-accessible, JP8-fueled, flame tube combustors using swirl-venturi lean direct injection (LDI) research hardware. The baseline LDI geometry has 9 fuel/air mixers arranged in a 3 x 3 array within a square chamber. 2-D results from this 9-element array are compared to results obtained in a cylindrical combustor using a 7-element array and a single element. In each case, the baseline element size remains the same. The effect of air swirler angle, and element arrangement on the presence of a central recirculation zone are presented. Only the highest swirl number air swirler produced a central recirculation zone for the single element swirl-venturi LDI and the 9-element LDI, but that same swirler did not produce a central recirculation zone for the 7-element LDI, possibly because of strong interactions due to element spacing within the array.

  11. Annular suspension and pointing system with controlled DC electromagnets

    NASA Technical Reports Server (NTRS)

    Vu, Josephine Lynn; Tam, Kwok Hung

    1993-01-01

    The Annular Suspension and Pointing System (ASPS) developed by the Flight System division of Sperry Corporation is a six-degree of freedom payload pointing system designed for use with the space shuttle. This magnetic suspension and pointing system provides precise controlled pointing in six-degrees of freedom, isolation of payload-carrier disturbances, and end mount controlled pointing. Those are great advantages over the traditional mechanical joints for space applications. In this design, we first analyzed the assumed model of the single degree ASPS bearing actuator and obtained the plant dynamics equations. By linearizing the plant dynamics equations, we designed the cascade and feedback compensators such that a stable and satisfied result was obtained. The specified feedback compensator was computer simulated with the nonlinearized plant dynamics equations. The results indicated that an unstable output occurred. In other words, the designed feedback compensator failed. The failure of the design is due to the Taylor's series expansion not converging.

  12. Planned LMSS propagation experiment using ACTS: Preliminary antenna pointing results during mobile operations

    NASA Technical Reports Server (NTRS)

    Rowland, John R.; Goldhirsh, Julius; Vogel, Wolfhard J.; Torrence, Geoffrey W.

    1991-01-01

    An overview and a status description of the planned LMSS mobile K band experiment with ACTS is presented. As a precursor to the ACTS mobile measurements at 20.185 GHz, measurements at 19.77 GHz employing the Olympus satellite were originally planned. However, because of the demise of Olympus in June of 1991, the efforts described here are focused towards the ACTS measurements. In particular, we describe the design and testing results of a gyro controlled mobile-antenna pointing system. Preliminary pointing measurements during mobile operations indicate that the present system is suitable for measurements employing a 15 cm aperture (beamwidth at approximately 7 deg) receiving antenna operating with ACTS in the high gain transponder mode. This should enable measurements with pattern losses smaller than plus or minus 1 dB over more than 95 percent of the driving distance. Measurements with the present mount system employing a 60 cm aperture (beamwidth at approximately 1.7 deg) results in pattern losses smaller than plus or minus 3 dB for 70 percent of the driving distance. Acceptable propagation measurements may still be made with this system by employing developed software to flag out bad data points due to extreme pointing errors. The receiver system including associated computer control software has been designed and assembled. Plans are underway to integrate the antenna mount with the receiver on the University of Texas mobile receiving van and repeat the pointing tests on highways employing a recently designed radome system.

  13. A new method to obtain ground control points based on SRTM data

    NASA Astrophysics Data System (ADS)

    Wang, Pu; An, Wei; Deng, Xin-pu; Zhang, Xi

    2013-09-01

    The GCPs are widely used in remote sense image registration and geometric correction. Normally, the DRG and DOM are the major data source from which GCPs are extracted. But the high accuracy products of DRG and DOM are usually costly to obtain. Some of the production are free, yet without any guarantee. In order to balance the cost and the accuracy, the paper proposes a method of extracting the GCPs from SRTM data. The method consist of artificial assistance, binarization, data resample and reshape. With artificial assistance to find out which part of SRTM data could be used as GCPs, such as the islands or sharp coast line. By utilizing binarization algorithm , the shape information of the region is obtained while other information is excluded. Then the binary data is resampled to a suitable resolution required by specific application. At last, the data would be reshaped according to satellite imaging type to obtain the GCPs which could be used. There are three advantages of the method proposed in the paper. Firstly, the method is easy for implementation. Unlike the DRG data or DOM data that charges a lot, the SRTM data is totally free to access without any constricts. Secondly, the SRTM has a high accuracy about 90m that is promised by its producer, so the GCPs got from it can also obtain a high quality. Finally, given the SRTM data covers nearly all the land surface of earth between latitude -60° and latitude +60°, the GCPs which are produced by the method can cover most important regions of the world. The method which obtain GCPs from SRTM data can be used in meteorological satellite image or some situation alike, which have a relative low requirement about the accuracy. Through plenty of simulation test, the method is proved convenient and effective.

  14. results obtained by the application of two different methods for the calculation of optimal coplanar orbital maneuvers with time limit

    NASA Astrophysics Data System (ADS)

    Rocco, Emr; Prado, Afbap; Souza, Mlos

    In this work, the problem of bi-impulsive orbital transfers between coplanar elliptical orbits with minimum fuel consumption but with a time limit for this transfer is studied. As a first method, the equations presented by Lawden (1993) were used. Those equations furnishes the optimal transfer orbit with fixed time for this transfer, between two elliptical coplanar orbits considering fixed terminal points. The method was adapted to cases with free terminal points and those equations was solved to develop a software for orbital maneuvers. As a second method, the equations presented by Eckel and Vinh (1984) were used, those equations provide the transfer orbit between non-coplanar elliptical orbits with minimum fuel and fixed time transfer, or minimum time transfer for a prescribed fuel consumption, considering free terminal points. But in this work only the problem with fixed time transfer was considered, the case of minimum time for a prescribed fuel consumption was already studied in Rocco et al. (2000). Then, the method was modified to consider cases of coplanar orbital transfer, and develop a software for orbital maneuvers. Therefore, two software that solve the same problem using different methods were developed. The first method, presented by Lawden, uses the primer vector theory. The second method, presented by Eckel and Vinh, uses the ordinary theory of maxima and minima. So, to test the methods we choose the same terminal orbits and the same time as input. We could verify that we didn't obtain exactly the same result. In this work, that is an extension of Rocco et al. (2002), these differences in the results are explored with objective of determining the reason of the occurrence of these differences and which modifications should be done to eliminate them.

  15. Quantitative assessment of the impact of biomedical image acquisition on the results obtained from image analysis and processing.

    PubMed

    Koprowski, Robert

    2014-07-04

    Dedicated, automatic algorithms for image analysis and processing are becoming more and more common in medical diagnosis. When creating dedicated algorithms, many factors must be taken into consideration. They are associated with selecting the appropriate algorithm parameters and taking into account the impact of data acquisition on the results obtained. An important feature of algorithms is the possibility of their use in other medical units by other operators. This problem, namely operator's (acquisition) impact on the results obtained from image analysis and processing, has been shown on a few examples. The analysed images were obtained from a variety of medical devices such as thermal imaging, tomography devices and those working in visible light. The objects of imaging were cellular elements, the anterior segment and fundus of the eye, postural defects and others. In total, almost 200'000 images coming from 8 different medical units were analysed. All image analysis algorithms were implemented in C and Matlab. For various algorithms and methods of medical imaging, the impact of image acquisition on the results obtained is different. There are different levels of algorithm sensitivity to changes in the parameters, for example: (1) for microscope settings and the brightness assessment of cellular elements there is a difference of 8%; (2) for the thyroid ultrasound images there is a difference in marking the thyroid lobe area which results in a brightness assessment difference of 2%. The method of image acquisition in image analysis and processing also affects: (3) the accuracy of determining the temperature in the characteristic areas on the patient's back for the thermal method - error of 31%; (4) the accuracy of finding characteristic points in photogrammetric images when evaluating postural defects - error of 11%; (5) the accuracy of performing ablative and non-ablative treatments in cosmetology - error of 18% for the nose, 10% for the cheeks, and 7% for the

  16. Obtaining patient test results from clinical laboratories: a survey of state law for pharmacists.

    PubMed

    Witry, Matthew J; Doucette, William R

    2009-01-01

    To identify states with laws that restrict to whom clinical laboratories may release copies of laboratory test results and to describe how these laws may affect pharmacists' ability to obtain patient laboratory test results. Researchers examined state statutes and administrative codes for all 50 states and the District of Columbia at the University of Iowa Law Library between June and July 2007. Researchers also consulted with lawyers, state Clinical Laboratory Improvement Amendments officers, and law librarians. Laws relating to the study objective were analyzed. 34 jurisdictions do not restrict the release of laboratory test results, while 17 states have laws that restrict to whom clinical laboratories can send copies of test results. In these states, pharmacists will have to use alternative sources, such as physician offices, to obtain test results. Pharmacists must consider state law before requesting copies of laboratory test results from clinical laboratories. This may be an issue that state pharmacy associations can address to increase pharmacist access to important patient information.

  17. On the structure of the set of coincidence points

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Arutyunov, A V; Gel'man, B D

    2015-03-31

    We consider the set of coincidence points for two maps between metric spaces. Cardinality, metric and topological properties of the coincidence set are studied. We obtain conditions which guarantee that this set (a) consists of at least two points; (b) consists of at least n points; (c) contains a countable subset; (d) is uncountable. The results are applied to study the structure of the double point set and the fixed point set for multivalued contractions. Bibliography: 12 titles.

  18. Fixed Point Theorems for Hybrid Mappings

    PubMed Central

    Kamran, Tayyab; Karapinar, Erdal

    2015-01-01

    We obtain some fixed point theorems for two pairs of hybrid mappings using hybrid tangential property and quadratic type contractive condition. Our results generalize some results by Babu and Alemayehu and those contained therein. In the sequel, we introduce a new notion to generalize occasionally weak compatibility. Moreover, two concrete examples are established to illuminate the generality of our results. PMID:25629089

  19. An adhered-particle analysis system based on concave points

    NASA Astrophysics Data System (ADS)

    Wang, Wencheng; Guan, Fengnian; Feng, Lin

    2018-04-01

    Particles adhered together will influence the image analysis in computer vision system. In this paper, a method based on concave point is designed. First, corner detection algorithm is adopted to obtain a rough estimation of potential concave points after image segmentation. Then, it computes the area ratio of the candidates to accurately localize the final separation points. Finally, it uses the separation points of each particle and the neighboring pixels to estimate the original particles before adhesion and provides estimated profile images. The experimental results have shown that this approach can provide good results that match the human visual cognitive mechanism.

  20. Automated and continual determination of radio telescope reference points with sub-mm accuracy: results from a campaign at the Onsala Space Observatory

    NASA Astrophysics Data System (ADS)

    Lösler, Michael; Haas, Rüdiger; Eschelbach, Cornelia

    2013-08-01

    The Global Geodetic Observing System (GGOS) requires sub-mm accuracy, automated and continual determinations of the so-called local tie vectors at co-location stations. Co-location stations host instrumentation for several space geodetic techniques and the local tie surveys involve the relative geometry of the reference points of these instruments. Thus, these reference points need to be determined in a common coordinate system, which is a particular challenge for rotating equipment like radio telescopes for geodetic Very Long Baseline Interferometry. In this work we describe a concept to achieve automated and continual determinations of radio telescope reference points with sub-mm accuracy. We developed a monitoring system, including Java-based sensor communication for automated surveys, network adjustment and further data analysis. This monitoring system was tested during a monitoring campaign performed at the Onsala Space Observatory in the summer of 2012. The results obtained in this campaign show that it is possible to perform automated determination of a radio telescope reference point during normal operations of the telescope. Accuracies on the sub-mm level can be achieved, and continual determinations can be realized by repeated determinations and recursive estimation methods.

  1. Vertical profiles of ozone, carbon monoxide, and dew-point temperature obtained during GTE/CITE 1, October-November 1983. [Chemical Instrumentation Test and Evaluation

    NASA Technical Reports Server (NTRS)

    Fishman, Jack; Gregory, Gerald L.; Sachse, Glen W.; Beck, Sherwin M.; Hill, Gerald F.

    1987-01-01

    A set of 14 pairs of vertical profiles of ozone and carbon monoxide, obtained with fast-response instrumentation, is presented. Most of these profiles, which were measured in the remote troposphere, also have supporting fast-response dew-point temperature profiles. The data suggest that the continental boundary layer is a source of tropospheric ozone, even in October and November, when photochemical activity should be rather small. In general, the small-scale vertical variability between CO and O3 is in phase. At low latitudes this relationship defines levels in the atmosphere where midlatitude air is being transported to lower latitudes, since lower dew-point temperatures accompany these higher CO and O3 concentrations. A set of profiles which is suggestive of interhemispheric transport is also presented. Independent meteorological analyses support these interpretations.

  2. Accuracy of the HumaSensplus point-of-care uric acid meter using capillary blood obtained by fingertip puncture.

    PubMed

    Fabre, Stéphanie; Clerson, Pierre; Launay, Jean-Marie; Gautier, Jean-François; Vidal-Trecan, Tiphaine; Riveline, Jean-Pierre; Platt, Adam; Abrahamsson, Anna; Miner, Jeffrey N; Hughes, Glen; Richette, Pascal; Bardin, Thomas

    2018-05-02

    The uric acid (UA) level in patients with gout is a key factor in disease management and is typically measured in the laboratory using plasma samples obtained after venous puncture. This study aimed to assess the reliability of immediate UA measurement with capillary blood samples obtained by fingertip puncture with the HumaSens plus point-of-care meter. UA levels were measured using both the HumaSens plus meter in the clinic and the routine plasma UA method in the biochemistry laboratory of 238 consenting diabetic patients. HumaSens plus capillary and routine plasma UA measurements were compared by linear regression, Bland-Altman plots, intraclass correlation coefficient (ICC), and Lin's concordance coefficient. Values outside the dynamic range of the meter, low (LO) or high (HI), were analyzed separately. The best capillary UA thresholds for detecting hyperuricemia were determined by receiver operating characteristic (ROC) curves. The impact of potential confounding factors (demographic and biological parameters/treatments) was assessed. Capillary and routine plasma UA levels were compared to reference plasma UA measurements by liquid chromatography-mass spectrometry (LC-MS) for a subgroup of 67 patients. In total, 205 patients had capillary and routine plasma UA measurements available. ICC was 0.90 (95% confidence interval (CI) 0.87-0.92), Lin's coefficient was 0.91 (0.88-0.93), and the Bland-Altman plot showed good agreement over all tested values. Overall, 17 patients showed values outside the dynamic range. LO values were concordant with plasma values, but HI values were considered uninterpretable. Capillary UA thresholds of 299 and 340 μmol/l gave the best results for detecting hyperuricemia (corresponding to routine plasma UA thresholds of 300 and 360 μmol/l, respectively). No significant confounding factor was found among those tested, except for hematocrit; however, this had a negligible influence on the assay reliability. When capillary and routine

  3. Predicting critical temperatures of ionic and non-ionic fluids from thermophysical data obtained near the melting point.

    PubMed

    Weiss, Volker C

    2015-10-14

    In the correlation and prediction of thermophysical data of fluids based on a corresponding-states approach, the critical temperature Tc plays a central role. For some fluids, in particular ionic ones, however, the critical region is difficult or even impossible to access experimentally. For molten salts, Tc is on the order of 3000 K, which makes accurate measurements a challenging task. Room temperature ionic liquids (RTILs) decompose thermally between 400 K and 600 K due to their organic constituents; this range of temperatures is hundreds of degrees below recent estimates of their Tc. In both cases, reliable methods to deduce Tc based on extrapolations of experimental data recorded at much lower temperatures near the triple or melting points are needed and useful because the critical point influences the fluid's behavior in the entire liquid region. Here, we propose to employ the scaling approach leading to universal fluid behavior [Román et al., J. Chem. Phys. 123, 124512 (2005)] to derive a very simple expression that allows one to estimate Tc from the density of the liquid, the surface tension, or the enthalpy of vaporization measured in a very narrow range of low temperatures. We demonstrate the validity of the approach for simple and polar neutral fluids, for which Tc is known, and then use the methodology to obtain estimates of Tc for ionic fluids. When comparing these estimates to those reported in the literature, good agreement is found for RTILs, whereas the ones for the molten salts NaCl and KCl are lower than previous estimates by 10%. The coexistence curve for ionic fluids is found to be more adequately described by an effective exponent of βeff = 0.5 than by βeff = 0.33.

  4. Results obtained with a low cost software-based audiometer for hearing screening.

    PubMed

    Ferrari, Deborah Viviane; Lopez, Esteban Alejandro; Lopes, Andrea Cintra; Aiello, Camila Piccini; Jokura, Pricila Reis

    2013-07-01

     The implementation of hearing screening programs can be facilitated by reducing operating costs, including the cost of equipment. The Telessaúde (TS) audiometer is a low-cost, software-based, and easy-to-use piece of equipment for conducting audiometric screening.  To evaluate the TS audiometer for conducting audiometric screening.  A prospective randomized study was performed. Sixty subjects, divided into those who did not have (group A, n = 30) and those who had otologic complaints (group B, n = 30), underwent audiometric screening with conventional and TS audiometers in a randomized order. Pure tones at 25 dB HL were presented at frequencies of 500, 1000, 2000, and 4000 Hz. A "fail" result was considered when the individual failed to respond to at least one of the stimuli. Pure-tone audiometry was also performed on all participants. The concordance of the results of screening with both audiometers was evaluated. The sensitivity, specificity, and positive and negative predictive values of screening with the TS audiometer were calculated.  For group A, 100% of the ears tested passed the screening. For group B, "pass" results were obtained in 34.2% (TS) and 38.3% (conventional) of the ears tested. The agreement between procedures (TS vs. conventional) ranged from 93% to 98%. For group B, screening with the TS audiometer showed 95.5% sensitivity, 90.4% sensitivity, and positive and negative predictive values equal to 94.9% and 91.5%, respectively.  The results of the TS audiometer were similar to those obtained with the conventional audiometer, indicating that the TS audiometer can be used for audiometric screening.

  5. Communicating to Learn: Infants' Pointing Gestures Result in Optimal Learning

    ERIC Educational Resources Information Center

    Lucca, Kelsey; Wilbourn, Makeba Parramore

    2018-01-01

    Infants' pointing gestures are a critical predictor of early vocabulary size. However, it remains unknown precisely how pointing relates to word learning. The current study addressed this question in a sample of 108 infants, testing one mechanism by which infants' pointing may influence their learning. In Study 1, 18-month-olds, but not…

  6. Fixed points of contractive mappings in b-metric-like spaces.

    PubMed

    Hussain, Nawab; Roshan, Jamal Rezaei; Parvaneh, Vahid; Kadelburg, Zoran

    2014-01-01

    We discuss topological structure of b-metric-like spaces and demonstrate a fundamental lemma for the convergence of sequences. As an application we prove certain fixed point results in the setup of such spaces for different types of contractive mappings. Finally, some periodic point results in b-metric-like spaces are obtained. Two examples are presented in order to verify the effectiveness and applicability of our main results.

  7. Fixed Points of Contractive Mappings in b-Metric-Like Spaces

    PubMed Central

    Hussain, Nawab; Roshan, Jamal Rezaei

    2014-01-01

    We discuss topological structure of b-metric-like spaces and demonstrate a fundamental lemma for the convergence of sequences. As an application we prove certain fixed point results in the setup of such spaces for different types of contractive mappings. Finally, some periodic point results in b-metric-like spaces are obtained. Two examples are presented in order to verify the effectiveness and applicability of our main results. PMID:25143980

  8. Three-dimensional displacement measurement of image point by point-diffraction interferometry

    NASA Astrophysics Data System (ADS)

    He, Xiao; Chen, Lingfeng; Meng, Xiaojie; Yu, Lei

    2018-01-01

    This paper presents a method for measuring the three-dimensional (3-D) displacement of an image point based on point-diffraction interferometry. An object Point-light-source (PLS) interferes with a fixed PLS and its interferograms are captured by an exit pupil. When the image point of the object PLS is slightly shifted to a new position, the wavefront of the image PLS changes. And its interferograms also change. Processing these figures (captured before and after the movement), the wavefront difference of the image PLS can be obtained and it contains the information of three-dimensional (3-D) displacement of the image PLS. However, the information of its three-dimensional (3-D) displacement cannot be calculated until the distance between the image PLS and the exit pupil is calibrated. Therefore, we use a plane-parallel-plate with a known refractive index and thickness to determine this distance, which is based on the Snell's law for small angle of incidence. Thus, since the distance between the exit pupil and the image PLS is a known quantity, the 3-D displacement of the image PLS can be simultaneously calculated through two interference measurements. Preliminary experimental results indicate that its relative error is below 0.3%. With the ability to accurately locate an image point (whatever it is real or virtual), a fiber point-light-source can act as the reticle by itself in optical measurement.

  9. NASA 9-Point LDI Code Validation Experiment

    NASA Technical Reports Server (NTRS)

    Hicks, Yolanda R.; Anderson, Robert C.; Locke, Randy J.

    2007-01-01

    This presentation highlights the experimental work to date to obtain validation data using a 9-point lean direct injector (LDI) in support of the National Combustion Code. The LDI is designed to supply fuel lean, Jet-A and air directly into the combustor such that the liquid fuel atomizes and mixes rapidly to produce short flame zones and produce low levels of oxides of nitrogen and CO. We present NOx and CO emission results from gas sample data that support that aspect of the design concept. We describe this injector and show high speed movies of selected operating points. We present image-based species maps of OH, fuel, CH and NO obtained using planar laser induced fluorescence and chemiluminescence. We also present preliminary 2-component, axial and vertical, velocity vectors of the air flow obtained using particle image velocimetry and of the fuel drops in a combusting case. For the same combusting case, we show preliminary 3-component velocity vectors obtained using a phase Doppler anemometer. For the fueled, combusting cases especially, we found optical density is a technical concern that must be addressed, but that in general, these preliminary results are promising. All optical-based results confirm that this injector produces short flames, typically on the order of 5- to-7-mm long at typical cruise and high power engine cycle conditions.

  10. Obtaining orthotropic elasticity tensor using entries zeroing method.

    NASA Astrophysics Data System (ADS)

    Gierlach, Bartosz; Danek, Tomasz

    2017-04-01

    A generally anisotropic elasticity tensor obtained from measurements can be represented by a tensor belonging to one of eight material symmetry classes. Knowledge of symmetry class and orientation is helpful for describing physical properties of a medium. For each non-trivial symmetry class except isotropic this problem is nonlinear. A common method of obtaining effective tensor is a choosing its non-trivial symmetry class and minimizing Frobenius norm between measured and effective tensor in the same coordinate system. Global optimization algorithm has to be used to determine the best rotation of a tensor. In this contribution, we propose a new approach to obtain optimal tensor, with the assumption that it is orthotropic (or at least has a similar shape to the orthotropic one). In orthotropic form tensor 24 out of 36 entries are zeros. The idea is to minimize the sum of squared entries which are supposed to be equal to zero through rotation calculated with optimization algorithm - in this case Particle Swarm Optimization (PSO) algorithm. Quaternions were used to parametrize rotations in 3D space to improve computational efficiency. In order to avoid a choice of local minima we apply PSO several times and only if we obtain similar results for the third time we consider it as a correct value and finish computations. To analyze obtained results Monte-Carlo method was used. After thousands of single runs of PSO optimization, we obtained values of quaternion parts and plot them. Points concentrate in several points of the graph following the regular pattern. It suggests the existence of more complex symmetry in the analyzed tensor. Then thousands of realizations of generally anisotropic tensor were generated - each tensor entry was replaced with a random value drawn from normal distribution having a mean equal to measured tensor entry and standard deviation of the measurement. Each of these tensors was subject of PSO based optimization delivering quaternion for optimal

  11. Emergency medical technician-performed point-of-care blood analysis using the capillary blood obtained from skin puncture.

    PubMed

    Kim, Changsun; Kim, Hansol

    2017-12-09

    Comparing a point-of-care (POC) test using the capillary blood obtained from skin puncture with conventional laboratory tests. In this study, which was conducted at the emergency department of a tertiary care hospital in April-July 2017, 232 patients were enrolled, and three types of blood samples (capillary blood from skin puncture, arterial and venous blood from blood vessel puncture) were simultaneously collected. Each blood sample was analyzed using a POC analyzer (epoc® system, USA), an arterial blood gas analyzer (pHOx®Ultra, Nova biomedical, USA) and venous blood analyzers (AU5800, DxH2401, Beckman Coulter, USA). Twelve parameters were compared between the epoc and reference analyzers, with an equivalence test, Bland-Altman plot analysis and linear regression employed to show the agreement or correlation between the two methods. The pH, HCO 3 , Ca 2+ , Na + , K + , Cl - , glucose, Hb and Hct measured by the epoc were equivalent to the reference values (95% confidence interval of mean difference within the range of the agreement target) with clinically inconsequential mean differences and narrow limits of agreement. All of them, except pH, had clinically acceptable agreements between the two methods (results within target value ≥80%). Of the remaining three parameters (pCO 2, pO 2 and lactate), the epoc pCO 2 and lactate values were highly correlated with the reference device values, whereas pO 2 was not. (pCO 2 : R 2 =0.824, y=-1.411+0.877·x; lactate: R 2 =0.902, y=-0.544+0.966·x; pO 2 : R 2 =0.037, y=61.6+0.431·x). Most parameters, except only pO 2 , measured by the epoc were equivalent to or correlated with those from the reference method. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Determination of Failure Point of Asphalt-Mixture Fatigue-Test Results Using the Flow Number Method

    NASA Astrophysics Data System (ADS)

    Wulan, C. E. P.; Setyawan, A.; Pramesti, F. P.

    2018-03-01

    The failure point of the results of fatigue tests of asphalt mixtures performed in controlled stress mode is difficult to determine. However, several methods from empirical studies are available to solve this problem. The objectives of this study are to determine the fatigue failure point of the results of indirect tensile fatigue tests using the Flow Number Method and to determine the best Flow Number model for the asphalt mixtures tested. In order to achieve these goals, firstly the best asphalt mixture of three was selected based on their Marshall properties. Next, the Indirect Tensile Fatigue Test was performed on the chosen asphalt mixture. The stress-controlled fatigue tests were conducted at a temperature of 20°C and frequency of 10 Hz, with the application of three loads: 500, 600, and 700 kPa. The last step was the application of the Flow Number methods, namely the Three-Stages Model, FNest Model, Francken Model, and Stepwise Method, to the results of the fatigue tests to determine the failure point of the specimen. The chosen asphalt mixture is EVA (Ethyl Vinyl Acetate) polymer -modified asphalt mixture with 6.5% OBC (Optimum Bitumen Content). Furthermore, the result of this study shows that the failure points of the EVA-modified asphalt mixture under loads of 500, 600, and 700 kPa are 6621, 4841, and 611 for the Three-Stages Model; 4271, 3266, and 537 for the FNest Model; 3401, 2431, and 421 for the Francken Model, and 6901, 6841, and 1291 for the Stepwise Method, respectively. These different results show that the bigger the loading, the smaller the number of cycles to failure. However, the best FN results are shown by the Three-Stages Model and the Stepwise Method, which exhibit extreme increases after the constant development of accumulated strain.

  13. Point force and point electric charge applied to the boundary of three-dimensional anisotropic piezoelectric solid

    DOE PAGES

    Borovikov, V. A.; Kalinin, S. V.; Khavin, Yu.; ...

    2015-08-19

    We derive the Green's functions for a three-dimensional semi-infinite fully anisotropic piezoelectric material using the plane wave theory method. The solution gives the complete set of electromechanical fields due to an arbitrarily oriented point force and a point electric charge applied to the boundary of the half-space. Moreover, the solution constitutes generalization of Boussinesq's and Cerruti's problems of elastic isotropy for the anisotropic piezoelectric materials. On the example of piezoceramics PZT-6B, the present results are compared with the previously obtained solution for the special case of transversely isotropic piezoelectric solid subjected to the same boundary condition.

  14. Cardinal and anti-cardinal points, equalities and chromatic dependence.

    PubMed

    Evans, Tanya; Harris, William F

    2017-05-01

    Cardinal points are used for ray tracing through Gaussian systems. Anti-principal and anti-nodal points (which we shall refer to as the anti-cardinal points), along with the six familiar cardinal points, belong to a much larger set of special points. The purpose of this paper is to obtain a set of relationships and resulting equalities among the cardinal and anti-cardinal points and to illustrate them using Pascal's ring. The methodology used relies on Gaussian optics and the transference T. We make use of two equations, obtained via the transference, which give the locations of the six cardinal and four anti-cardinal points with respect to the system. We obtain equalities among the cardinal and anti-cardinal points. We utilise Pascal's ring to illustrate which points depend on frequency and their displacement with change in frequency. Pascal described a memory schema in the shape of a hexagon for remembering equalities among the points and illustrating shifts in these points when an aspect of the system changes. We modify and extend Pascal's ring to include the anti-cardinal points. We make use of Pascal's ring extended to illustrate which points are dependent on the frequency of light and the direction of shift of the equalities with change in frequency. For the reduced eye the principal and nodal points are independent of frequency, but the focal points and the anti-cardinal points depend on frequency. For Le Grand's four-surface model eye all six cardinal and four anti-cardinal points depend on frequency. This has implications for definitions, particularly of chromatic aberrations of the eye, that make use of cardinal points and that themselves depend on frequency. Pascal's ring and Pascal's ring extended are novel memory schema for remembering the equalities among the cardinal and anti-cardinal points. The rings are useful for illustrating changes among the equalities and direction of shift of points when an aspect of a system changes. Care should be taken

  15. Theoretical evaluation of accuracy in position and size of brain activity obtained by near-infrared topography

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Hiroshi; Hayashi, Toshiyuki; Kato, Toshinori; Okada, Eiji

    2004-06-01

    Near-infrared (NIR) topography can obtain a topographical distribution of the activated region in the brain cortex. Near-infrared light is strongly scattered in the head, and the volume of tissue sampled by a source-detector pair on the head surface is broadly distributed in the brain. This scattering effect results in poor resolution and contrast in the topographic image of the brain activity. In this study, a one-dimensional distribution of absorption change in a head model is calculated by mapping and reconstruction methods to evaluate the effect of the image reconstruction algorithm and the interval of measurement points for topographic imaging on the accuracy of the topographic image. The light propagation in the head model is predicted by Monte Carlo simulation to obtain the spatial sensitivity profile for a source-detector pair. The measurement points are one-dimensionally arranged on the surface of the model, and the distance between adjacent measurement points is varied from 4 mm to 28 mm. Small intervals of the measurement points improve the topographic image calculated by both the mapping and reconstruction methods. In the conventional mapping method, the limit of the spatial resolution depends upon the interval of the measurement points and spatial sensitivity profile for source-detector pairs. The reconstruction method has advantages over the mapping method which improve the results of one-dimensional analysis when the interval of measurement points is less than 12 mm. The effect of overlapping of spatial sensitivity profiles indicates that the reconstruction method may be effective to improve the spatial resolution of a two-dimensional reconstruction of topographic image obtained with larger interval of measurement points. Near-infrared topography with the reconstruction method potentially obtains an accurate distribution of absorption change in the brain even if the size of absorption change is less than 10 mm.

  16. Compliance measurements of chevron notched four point bend specimen

    NASA Technical Reports Server (NTRS)

    Calomino, Anthony; Bubsey, Raymond; Ghosn, Louis J.

    1994-01-01

    The experimental stress intensity factors for various chevron notched four point bend specimens are presented. The experimental compliance is verified using the analytical solution for a straight through crack four point bend specimen and the boundary integral equation method for one chevron geometry. Excellent agreement is obtained between the experimental and analytical results. In this report, stress intensity factors, loading displacements and crack mouth opening displacements are reported for different crack lengths and different chevron geometries, under four point bend loading condition.

  17. Satisfaction with the local service point for care: results of an evaluation study

    PubMed Central

    Esslinger, Adelheid Susanne; Macco, Katrin; Schmidt, Katharina

    2009-01-01

    Purpose The market of care increases and is characterized by complexity. Therefore, service points, such as the ‘Zentrale Anlaufstelle Pflege (ZAPf)’ in Nuremberg, are helpful for clients to get orientation. The purpose of the presentation is to show the results of an evaluation study about the clients' satisfaction with the offers of ZAPf. Study Satisfaction with service may be measured with the SERVQUAL concept introduced by Parasuraman et al. (1988). They found out five dimensions of quality (tangibles, reliability, responsiveness, assurances and empathy). We took these dimensions in our study. The study focuses on the quality of service and the benefits recognized by clients. In spring 2007, we conducted 67 interviews by phone, based on a half standardized questionnaire. Statistical analysis was conducted using SPSS. Results The clients want to get information about care in general, financial and legal aspects, alternative care arrangement (e.g. ambulant, long-term care) and typical age-related diseases. They show a high satisfaction with the service provided. Their benefits are to get information and advice, to strengthen the ability of decision taking, to cope with changing situations in life, and to develop solutions. Conclusions The results show that the quality of service is on a high level. Critical success factors are the interdisciplinary cooperation at the service point, based on a regularly and open exchange of information. Every member focuses on an optimal individual solution for the client. Local professional service points act as networkers and brokers. They serve not only for the clients' needs but also support the effective and efficient provision of optimized care.

  18. Nearly fully compressed 1053 nm pulses directly obtained from 800 nm laser-seeded photonic crystal fiber below zero dispersion point

    NASA Astrophysics Data System (ADS)

    Refaeli, Zaharit; Shamir, Yariv; Ofir, Atara; Marcus, Gilad

    2018-02-01

    We report a simple robust and broadly spectral-adjustable source generating near fully compressed 1053 nm 62 fs pulses directly out of a highly-nonlinear photonic crystal fiber. A dispersion-nonlinearity balance of 800 nm Ti:Sa 20 fs pulses was obtained initially by negative pre-chirping and then launching the pulses into the fibers' normal dispersion regime. Following a self-phase modulation spectral broadening, some energy that leaked below the zero dispersion point formed a soliton whose central wavelength could be tuned by Self-Frequency-Raman-Shift effect. Contrary to a common approach of power, or, fiber-length control over the shift, here we continuously varied the state of polarization, exploiting the Raman and Kerr nonlinearities responsivity for state of polarization. We obtained soliton pulses with central wavelength tuned over 150 nm, spanning from well below 1000 to over 1150 nm, of which we could select stable pulses around the 1 μm vicinity. With linewidth of > 20 nm FWHM Gaussian-like temporal-shape pulses with 62 fs duration and near flat phase structure we confirmed high quality pulse source. We believe such scheme can be used for high energy or high power glass lasers systems, such as Nd or Yb ion-doped amplifiers and systems.

  19. Results of the 2013 UT modeling benchmark obtained with models implemented in CIVA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Toullelan, Gwénaël; Raillon, Raphaële; Chatillon, Sylvain

    The 2013 Ultrasonic Testing (UT) modeling benchmark concerns direct echoes from side drilled holes (SDH), flat bottom holes (FBH) and corner echoes from backwall breaking artificial notches inspected with a matrix phased array probe. This communication presents the results obtained with the models implemented in the CIVA software: the pencilmodel is used to compute the field radiated by the probe, the Kirchhoff approximation is applied to predict the response of FBH and notches and the SOV (Separation Of Variables) model is used for the SDH responses. The comparison between simulated and experimental results are presented and discussed.

  20. The Segmentation of Point Clouds with K-Means and ANN (artifical Neural Network)

    NASA Astrophysics Data System (ADS)

    Kuçak, R. A.; Özdemir, E.; Erol, S.

    2017-05-01

    Segmentation of point clouds is recently used in many Geomatics Engineering applications such as the building extraction in urban areas, Digital Terrain Model (DTM) generation and the road or urban furniture extraction. Segmentation is a process of dividing point clouds according to their special characteristic layers. The present paper discusses K-means and self-organizing map (SOM) which is a type of ANN (Artificial Neural Network) segmentation algorithm which treats the segmentation of point cloud. The point clouds which generate with photogrammetric method and Terrestrial Lidar System (TLS) were segmented according to surface normal, intensity and curvature. Thus, the results were evaluated. LIDAR (Light Detection and Ranging) and Photogrammetry are commonly used to obtain point clouds in many remote sensing and geodesy applications. By photogrammetric method or LIDAR method, it is possible to obtain point cloud from terrestrial or airborne systems. In this study, the measurements were made with a Leica C10 laser scanner in LIDAR method. In photogrammetric method, the point cloud was obtained from photographs taken from the ground with a 13 MP non-metric camera.

  1. A method for automatic feature points extraction of human vertebrae three-dimensional model

    NASA Astrophysics Data System (ADS)

    Wu, Zhen; Wu, Junsheng

    2017-05-01

    A method for automatic extraction of the feature points of the human vertebrae three-dimensional model is presented. Firstly, the statistical model of vertebrae feature points is established based on the results of manual vertebrae feature points extraction. Then anatomical axial analysis of the vertebrae model is performed according to the physiological and morphological characteristics of the vertebrae. Using the axial information obtained from the analysis, a projection relationship between the statistical model and the vertebrae model to be extracted is established. According to the projection relationship, the statistical model is matched with the vertebrae model to get the estimated position of the feature point. Finally, by analyzing the curvature in the spherical neighborhood with the estimated position of feature points, the final position of the feature points is obtained. According to the benchmark result on multiple test models, the mean relative errors of feature point positions are less than 5.98%. At more than half of the positions, the error rate is less than 3% and the minimum mean relative error is 0.19%, which verifies the effectiveness of the method.

  2. Continuum Limit of Total Variation on Point Clouds

    NASA Astrophysics Data System (ADS)

    García Trillos, Nicolás; Slepčev, Dejan

    2016-04-01

    We consider point clouds obtained as random samples of a measure on a Euclidean domain. A graph representing the point cloud is obtained by assigning weights to edges based on the distance between the points they connect. Our goal is to develop mathematical tools needed to study the consistency, as the number of available data points increases, of graph-based machine learning algorithms for tasks such as clustering. In particular, we study when the cut capacity, and more generally total variation, on these graphs is a good approximation of the perimeter (total variation) in the continuum setting. We address this question in the setting of Γ-convergence. We obtain almost optimal conditions on the scaling, as the number of points increases, of the size of the neighborhood over which the points are connected by an edge for the Γ-convergence to hold. Taking of the limit is enabled by a transportation based metric which allows us to suitably compare functionals defined on different point clouds.

  3. Computer Simulation Results for the Two-Point Probability Function of Composite Media

    NASA Astrophysics Data System (ADS)

    Smith, P.; Torquato, S.

    1988-05-01

    Computer simulation results are reported for the two-point matrix probability function S2 of two-phase random media composed of disks distributed with an arbitrary degree of impenetrability λ. The novel technique employed to sample S2( r) (which gives the probability of finding the endpoints of a line segment of length r in the matrix) is very accurate and has a fast execution time. Results for the limiting cases λ = 0 (fully penetrable disks) and λ = 1 (hard disks), respectively, compare very favorably with theoretical predictions made by Torquato and Beasley and by Torquato and Lado. Results are also reported for several values of λ. that lie between these two extremes: cases which heretofore have not been examined.

  4. Sampling bird communities in bottomland hardwood forests of the Mississippi Alluvial Valley: Number of points visited versus number of visits to a point

    USGS Publications Warehouse

    Twedt, D.J.; Smith, W.P.; Cooper, R.J.; Ford, R.P.; Hamel, P.B.; Wiedenfeld, D.A.; Smith, Winston Paul

    1993-01-01

    Within each of 4 forest stands on Delta Experimental Forest (DEF), 25 points were visited 5 to 7 times from 8 May to 21 May 1991, and 6 times from 30 May to 12 June 1992. During each visit to a point, all birds detected, visuallyor aurally, at any distance were recorded during a 4-minute interval. Using these data, our objectives were to recommend the number of point counts and the number of visits to a point which provide the greatest efficiency for estimating the cumulative number of species in bottomland hardwood forest stands within the Mississippi Alluvial Valley, and to ascertain if increasing the number of visits to points is equivalent to adding more points. Because the total number of species detected in DEF were different between years, 39 species in 1991 and 55 species in 1992, we considered each year independently. Within each stand, we obtained bootstrap estimates of the mean cumulative number of species obtained from all possible combinations of six points and six visits (i.e., 36 means/stand). These bootstrap estimates were subjected to ANOVA; we modelled cumulative number of species as a function of the number of points visited, the number of visits to each point, and their interaction. As part of the same ANOVA we made an a priori, simultaneous comparison of the 15 possible reciprocal treatments (i.e., 1 point-2 visits vs. 2 points-1 visit, etc.). Results of analyses for each year were similar. Although no interaction was detected between the number of points and the number of visits, when reciprocals were compared, more points visited yielded significantly greater cumulative number of species than more visits to each point. Significant differences were detected among both the number of points visited and among the number of visits to a point. Scheffe's test of differences among means indicated that the cumulative number of species increased significantly with each added point, through five points, but six points did not differ from five points in

  5. A Robust False Matching Points Detection Method for Remote Sensing Image Registration

    NASA Astrophysics Data System (ADS)

    Shan, X. J.; Tang, P.

    2015-04-01

    Given the influences of illumination, imaging angle, and geometric distortion, among others, false matching points still occur in all image registration algorithms. Therefore, false matching points detection is an important step in remote sensing image registration. Random Sample Consensus (RANSAC) is typically used to detect false matching points. However, RANSAC method cannot detect all false matching points in some remote sensing images. Therefore, a robust false matching points detection method based on Knearest- neighbour (K-NN) graph (KGD) is proposed in this method to obtain robust and high accuracy result. The KGD method starts with the construction of the K-NN graph in one image. K-NN graph can be first generated for each matching points and its K nearest matching points. Local transformation model for each matching point is then obtained by using its K nearest matching points. The error of each matching point is computed by using its transformation model. Last, L matching points with largest error are identified false matching points and removed. This process is iterative until all errors are smaller than the given threshold. In addition, KGD method can be used in combination with other methods, such as RANSAC. Several remote sensing images with different resolutions and terrains are used in the experiment. We evaluate the performance of KGD method, RANSAC + KGD method, RANSAC, and Graph Transformation Matching (GTM). The experimental results demonstrate the superior performance of the KGD and RANSAC + KGD methods.

  6. Legibility Evaluation Using Point-of-regard Measurement

    NASA Astrophysics Data System (ADS)

    Saito, Daisuke; Saito, Keiichi; Saito, Masao

    Web site visibility has become important because of the rapid dissemination of World Wide Web, and combinations of foreground and background colors are crucial in providing high visibility. In our previous studies, the visibilities of several web-safe color combinations were examined using a psychological method. In those studies, simple stimuli were used because of experimental restriction. In this paper, legibility of sentences on web sites was examined using a psychophisiological method, point-of-regard measurement, to obtain other practical data. Ten people with normal color sensations ranging from ages 21 to 29 were recruited. The number of characters per line in each page was arranged in the same number, and the four representative achromatic web-safe colors, that is, #000000, #666666, #999999 and #CCCCCC, were examined. The reading time per character and the gaze time per line were obtained from point-of-regard measurement, and the normalized with the reading time and the gaze time of the three colors were calculated and compared. As the results, it was shown that the time of reading and gaze become long at the same ratio when the contrast decreases by point-of-regard measurement. Therefore, it was indicated that the legibility of color combinations could be estimated by point-of-regard measurement.

  7. Accurate Acoustic Thermometry I: The Triple Point of Gallium

    NASA Astrophysics Data System (ADS)

    Moldover, M. R.; Trusler, J. P. M.

    1988-01-01

    The speed of sound in argon has been accurately measured in the pressure range 25-380 kPa at the temperature of the triple point of gallium (Tg) and at 340 kPa at the temperature of the triple point of water (Tt). The results are combined with previously published thermodynamic and transport property data to obtain Tg = (302.9169 +/- 0.0005) K on the thermodynamic scale. Among recent determinations of T68 (the temperature on IPTS-68) at the gallium triple point, those with the smallest measurement uncertainty fall in the range 302.923 71 to 302.923 98 K. We conclude that T-T68 = (-6.9 +/- 0.5) mK near 303 K, in agreement with results obtained from other primary thermometers. The speed of sound was measured with a spherical resonator. The volume and thermal expansion of the resonator were determined by weighing the mercury required to fill it at Tt and Tg. The largest part of the standard error in the present determination of Tg is systematic. It results from imperfect knowledge of the thermal expansion of mercury between Tt and Tg. Smaller parts of the error result from imperfections in the measurement of the temperature of the resonator and of the resonance frequencies.

  8. Students' Progression in Monitoring Anomalous Results Obtained in Inquiry-Based Laboratory Tasks

    NASA Astrophysics Data System (ADS)

    Crujeiras-Pérez, Beatriz; Jiménez-Aleixandre, Maria Pilar

    2017-07-01

    This paper examines students' engagement in monitoring anomalous results across a 2-year longitudinal study with 9th and 10th graders (14-15 and 15-16 years of age). The context is a set of five inquiry-based laboratory tasks, requiring students to plan and carry out investigations. The study seeks to examine students' interpretation of data, in particular anomalous results generated by them during the process of solving the tasks, and their ability to monitor them. Data collected include video and audio recordings as well as students' written products. For the analysis, two rubrics were developed drawing on Chinn and Brewer (Cognition and Instruction, 19, 323-393, 2001) and Hmelo-Silver et al. (Science Education, 86, 219-243, 2002). The findings point to a pattern of progress in students' responses across the 2 years: (a) responses revealing a low capacity of monitoring due to not recognizing the data as anomalous or recognizing it as anomalous but being unable to explain their causes are more frequent in the first tasks and (b) responses revealing an improved capacity of monitoring are more frequent in the last tasks. The factors influencing students' regulation of their performances, as the requirement of planning, and specific scaffolding based on activity theory are discussed.

  9. Evaluation of methods for rapid determination of freezing point of aviation fuels

    NASA Technical Reports Server (NTRS)

    Mathiprakasam, B.

    1982-01-01

    Methods for identification of the more promising concepts for the development of a portable instrument to rapidly determine the freezing point of aviation fuels are described. The evaluation process consisted of: (1) collection of information on techniques previously used for the determination of the freezing point, (2) screening and selection of these techniques for further evaluation of their suitability in a portable unit for rapid measurement, and (3) an extensive experimental evaluation of the selected techniques and a final selection of the most promising technique. Test apparatuses employing differential thermal analysis and the change in optical transparency during phase change were evaluated and tested. A technique similar to differential thermal analysis using no reference fuel was investigated. In this method, the freezing point was obtained by digitizing the data and locating the point of inflection. Results obtained using this technique compare well with those obtained elsewhere using different techniques. A conceptual design of a portable instrument incorporating this technique is presented.

  10. Comparison between non-invasive methods used on paintings by Goya and his contemporaries: hyperspectral imaging vs. point-by-point spectroscopic analysis.

    PubMed

    Daniel, Floréal; Mounier, Aurélie; Pérez-Arantegui, Josefina; Pardos, Carlos; Prieto-Taboada, Nagore; Fdez-Ortiz de Vallejuelo, Silvia; Castro, Kepa

    2017-06-01

    The development of non-invasive techniques for the characterization of pigments is crucial in order to preserve the integrity of the artwork. In this sense, the usefulness of hyperspectral imaging was demonstrated. It allows pigment characterization of the whole painting. However, it also sometimes requires the complementation of other point-by-point techniques. In the present article, the advantages of hyperspectral imaging over point-by-point spectroscopic analysis were evaluated. For that purpose, three paintings were analysed by hyperspectral imaging, handheld X-ray fluorescence and handheld Raman spectroscopy in order to determine the best non-invasive technique for pigment identifications. Thanks to this work, the main pigments used in Aragonese artworks, and especially in Goya's paintings, were identified and mapped by imaging reflection spectroscopy. All the analysed pigments corresponded to those used at the time of Goya. Regarding the techniques used, the information obtained by the hyperspectral imaging and point-by-point analysis has been, in general, different and complementary. Given this fact, selecting only one technique is not recommended, and the present work demonstrates the usefulness of the combination of all the techniques used as the best non-invasive methodology for the pigments' characterization. Moreover, the proposed methodology is a relatively quick procedure that allows a larger number of Goya's paintings in the museum to be surveyed, increasing the possibility of obtaining significant results and providing a chance for extensive comparisons, which are relevant from the point of view of art history issues.

  11. Representing ductile damage with the dual domain material point method

    DOE PAGES

    Long, C. C.; Zhang, D. Z.; Bronkhorst, C. A.; ...

    2015-12-14

    In this study, we incorporate a ductile damage material model into a computational framework based on the Dual Domain Material Point (DDMP) method. As an example, simulations of a flyer plate experiment involving ductile void growth and material failure are performed. The results are compared with experiments performed on high purity tantalum. We also compare the numerical results obtained from the DDMP method with those obtained from the traditional Material Point Method (MPM). Effects of an overstress model, artificial viscosity, and physical viscosity are investigated. Our results show that a physical bulk viscosity and overstress model are important in thismore » impact and failure problem, while physical shear viscosity and artificial shock viscosity have negligible effects. A simple numerical procedure with guaranteed convergence is introduced to solve for the equilibrium plastic state from the ductile damage model.« less

  12. Empirical study on human acupuncture point network

    NASA Astrophysics Data System (ADS)

    Li, Jian; Shen, Dan; Chang, Hui; He, Da-Ren

    2007-03-01

    Chinese medical theory is ancient and profound, however is confined by qualitative and faint understanding. The effect of Chinese acupuncture in clinical practice is unique and effective, and the human acupuncture points play a mysterious and special role, however there is no modern scientific understanding on human acupuncture points until today. For this reason, we attend to use complex network theory, one of the frontiers in the statistical physics, for describing the human acupuncture points and their connections. In the network nodes are defined as the acupuncture points, two nodes are connected by an edge when they are used for a medical treatment of a common disease. A disease is defined as an act. Some statistical properties have been obtained. The results certify that the degree distribution, act degree distribution, and the dependence of the clustering coefficient on both of them obey SPL distribution function, which show a function interpolating between a power law and an exponential decay. The results may be helpful for understanding Chinese medical theory.

  13. Near-Infrared Scintillation of Liquid Argon: Recent Results Obtained with the NIR Facility at Fermilab

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Escobar, C. O.; Rubinov, P.; Tilly, E.

    After a short review of previous attempts to observe and measure the near-infrared scintillation in liquid argon, we present new results obtained with NIR, a dedicated cryostat at the Fermilab Proton Assembly Building (PAB). The new results give confidence that the near-infrared light can be used as the much needed light signal in large liquid argon time projection chambers.11 pages,

  14. Isoelectric points and points of zero charge of metal (hydr)oxides: 50years after Parks' review.

    PubMed

    Kosmulski, Marek

    2016-12-01

    The pH-dependent surface charging of metal (hydr)oxides is reviewed on the occasion of the 50th anniversary of the publication by G.A. Parks: "Isoelectric points of solid oxides, solid hydroxides, and aqueous hydroxo complex systems" in Chemical Reviews. The point of zero charge (PZC) and isoelectric point (IEP) became standard parameters to characterize metal oxides in aqueous dispersions, and they define adsorption (surface excess) of ions, stability against coagulation, rheological properties of dispersions, etc. They are commonly used in many branches of science including mineral processing, soil science, materials science, geochemistry, environmental engineering, and corrosion science. Parks established standard procedures and experimental conditions which are required to obtain reliable and reproducible values of PZC and IEP. The field is very active, and the number of related papers exceeds 300 a year, and the standards established by Parks remain still valid. Relevant experimental techniques improved over the years, especially the measurements of electrophoretic mobility became easier and more reliable, are the numerical values of PZC and IEP compiled by Parks were confirmed by contemporary publications with a few exceptions. The present paper is an up-to-date compilation of the values of PZC and IEP of metal oxides. Unlike in former reviews by the same author, which were more comprehensive, only limited number of selected results are presented and discussed here. On top of the results obtained by means of classical methods (titration and electrokinetic methods), new methods and correlations found over the recent 50years are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Results of Investigative Tests of Gas Turbine Engine Compressor Blades Obtained by Electrochemical Machining

    NASA Astrophysics Data System (ADS)

    Kozhina, T. D.; Kurochkin, A. V.

    2016-04-01

    The paper highlights results of the investigative tests of GTE compressor Ti-alloy blades obtained by the method of electrochemical machining with oscillating tool-electrodes, carried out in order to define the optimal parameters of the ECM process providing attainment of specified blade quality parameters given in the design documentation, while providing maximal performance. The new technological methods suggested based on the results of the tests; in particular application of vibrating tool-electrodes and employment of locating elements made of high-strength materials, significantly extend the capabilities of this method.

  16. Point-of-care testing of electrolytes and calcium using blood gas analysers: it is time we trusted the results.

    PubMed

    Mirzazadeh, Mehdi; Morovat, Alireza; James, Tim; Smith, Ian; Kirby, Justin; Shine, Brian

    2016-03-01

    Point-of-care testing allows rapid analysis of samples to facilitate prompt clinical decisions. Electrolyte and calcium abnormalities are common in acutely ill patients and can be associated with life-threatening consequences. There is uncertainty whether clinical decisions can be based on the results obtained from blood gas analysers or if laboratory results should be awaited. To assess the agreement between sodium, potassium and calcium results from blood gas and laboratory mainstream analysers in a tertiary centre, with a network consisting of one referral and two peripheral hospitals, consisting of three networked clinical biochemistry laboratories. Using the laboratory information management system database and over 11 000 paired samples in three hospital sites, the results of sodium, potassium and ionised calcium on blood gas analysers were studied over a 5-year period and compared with the corresponding laboratory results from the same patients booked in the laboratory within 1 h. The Pearson's linear correlation coefficient between laboratory and blood gas results for sodium, potassium and calcium were 0.92, 0.84 and 0.78, respectively. Deming regression analysis showed a slope of 1.04 and an intercept of -5.7 for sodium, slope of 0.93 and an intercept of 0.22 for potassium and a slope of 1.23 with an intercept of -0.55 for calcium. With some strict statistical assumptions, percentages of results lying outside the least significant difference were 9%, 26.7% and 20.8% for sodium, potassium and calcium, respectively. Most clinicians wait for the laboratory confirmation of results generated by blood gas analysers. In a large retrospective study we have shown that there is sufficient agreement between the results obtained from the blood gas and laboratory analysers to enable prompt clinical decisions to be made. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  17. Legionella in water samples: how can you interpret the results obtained by quantitative PCR?

    PubMed

    Ditommaso, Savina; Ricciardi, Elisa; Giacomuzzi, Monica; Arauco Rivera, Susan R; Zotti, Carla M

    2015-02-01

    Evaluation of the potential risk associated with Legionella has traditionally been determined from culture-based methods. Quantitative polymerase chain reaction (qPCR) is an alternative tool that offers rapid, sensitive and specific detection of Legionella in environmental water samples. In this study we compare the results obtained by conventional qPCR (iQ-Check™ Quanti Legionella spp.; Bio-Rad) and by culture method on artificial samples prepared in Page's saline by addiction of Legionella pneumophila serogroup 1 (ATCC 33152) and we analyse the selective quantification of viable Legionella cells by the qPCR-PMA method. The amount of Legionella DNA (GU) determined by qPCR was 28-fold higher than the load detected by culture (CFU). Applying the qPCR combined with PMA treatment we obtained a reduction of 98.5% of the qPCR signal from dead cells. We observed a dissimilarity in the ability of PMA to suppress the PCR signal in samples with different amounts of bacteria: the effective elimination of detection signals by PMA depended on the concentration of GU and increasing amounts of cells resulted in higher values of reduction. Using the results from this study we created an algorithm to facilitate the interpretation of viable cell level estimation with qPCR-PMA. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Coarse Point Cloud Registration by Egi Matching of Voxel Clusters

    NASA Astrophysics Data System (ADS)

    Wang, Jinhu; Lindenbergh, Roderik; Shen, Yueqian; Menenti, Massimo

    2016-06-01

    Laser scanning samples the surface geometry of objects efficiently and records versatile information as point clouds. However, often more scans are required to fully cover a scene. Therefore, a registration step is required that transforms the different scans into a common coordinate system. The registration of point clouds is usually conducted in two steps, i.e. coarse registration followed by fine registration. In this study an automatic marker-free coarse registration method for pair-wise scans is presented. First the two input point clouds are re-sampled as voxels and dimensionality features of the voxels are determined by principal component analysis (PCA). Then voxel cells with the same dimensionality are clustered. Next, the Extended Gaussian Image (EGI) descriptor of those voxel clusters are constructed using significant eigenvectors of each voxel in the cluster. Correspondences between clusters in source and target data are obtained according to the similarity between their EGI descriptors. The random sampling consensus (RANSAC) algorithm is employed to remove outlying correspondences until a coarse alignment is obtained. If necessary, a fine registration is performed in a final step. This new method is illustrated on scan data sampling two indoor scenarios. The results of the tests are evaluated by computing the point to point distance between the two input point clouds. The presented two tests resulted in mean distances of 7.6 mm and 9.5 mm respectively, which are adequate for fine registration.

  19. Poor textural image tie point matching via graph theory

    NASA Astrophysics Data System (ADS)

    Yuan, Xiuxiao; Chen, Shiyu; Yuan, Wei; Cai, Yang

    2017-07-01

    Feature matching aims to find corresponding points to serve as tie points between images. Robust matching is still a challenging task when input images are characterized by low contrast or contain repetitive patterns, occlusions, or homogeneous textures. In this paper, a novel feature matching algorithm based on graph theory is proposed. This algorithm integrates both geometric and radiometric constraints into an edge-weighted (EW) affinity tensor. Tie points are then obtained by high-order graph matching. Four pairs of poor textural images covering forests, deserts, bare lands, and urban areas are tested. For comparison, three state-of-the-art matching techniques, namely, scale-invariant feature transform (SIFT), speeded up robust features (SURF), and features from accelerated segment test (FAST), are also used. The experimental results show that the matching recall obtained by SIFT, SURF, and FAST varies from 0 to 35% in different types of poor textures. However, through the integration of both geometry and radiometry and the EW strategy, the recall obtained by the proposed algorithm is better than 50% in all four image pairs. The better matching recall improves the number of correct matches, dispersion, and positional accuracy.

  20. Evaluation of a multi-point method for determining acoustic impedance

    NASA Technical Reports Server (NTRS)

    Jones, Michael G.; Parrott, Tony L.

    1988-01-01

    An investigation was conducted to explore potential improvements provided by a Multi-Point Method (MPM) over the Standing Wave Method (SWM) and Two-Microphone Method (TMM) for determining acoustic impedance. A wave propagation model was developed to model the standing wave pattern in an impedance tube. The acoustic impedance of a test specimen was calculated from a best fit of this standing wave pattern to pressure measurements obtained along the impedance tube centerline. Three measurement spacing distributions were examined: uniform, random, and selective. Calculated standing wave patterns match the point pressure measurement distributions with good agreement for a reflection factor magnitude range of 0.004 to 0.999. Comparisons of results using 2, 3, 6, and 18 measurement points showed that the most consistent results are obtained when using at least 6 evenly spaced pressure measurements per half-wavelength. Also, data were acquired with broadband noise added to the discrete frequency noise and impedances were calculated using the MPM and TMM algorithms. The results indicate that the MPM will be superior to the TMM in the presence of significant broadband noise levels associated with mean flow.

  1. A fast image matching algorithm based on key points

    NASA Astrophysics Data System (ADS)

    Wang, Huilin; Wang, Ying; An, Ru; Yan, Peng

    2014-05-01

    Image matching is a very important technique in image processing. It has been widely used for object recognition and tracking, image retrieval, three-dimensional vision, change detection, aircraft position estimation, and multi-image registration. Based on the requirements of matching algorithm for craft navigation, such as speed, accuracy and adaptability, a fast key point image matching method is investigated and developed. The main research tasks includes: (1) Developing an improved celerity key point detection approach using self-adapting threshold of Features from Accelerated Segment Test (FAST). A method of calculating self-adapting threshold was introduced for images with different contrast. Hessian matrix was adopted to eliminate insecure edge points in order to obtain key points with higher stability. This approach in detecting key points has characteristics of small amount of computation, high positioning accuracy and strong anti-noise ability; (2) PCA-SIFT is utilized to describe key point. 128 dimensional vector are formed based on the SIFT method for the key points extracted. A low dimensional feature space was established by eigenvectors of all the key points, and each eigenvector was projected onto the feature space to form a low dimensional eigenvector. These key points were re-described by dimension-reduced eigenvectors. After reducing the dimension by the PCA, the descriptor was reduced to 20 dimensions from the original 128. This method can reduce dimensions of searching approximately near neighbors thereby increasing overall speed; (3) Distance ratio between the nearest neighbour and second nearest neighbour searching is regarded as the measurement criterion for initial matching points from which the original point pairs matched are obtained. Based on the analysis of the common methods (e.g. RANSAC (random sample consensus) and Hough transform cluster) used for elimination false matching point pairs, a heuristic local geometric restriction

  2. Point-to-point people with purpose—Exploring the possibility of a commercial traveler market for point-to-point suborbital space transportation

    NASA Astrophysics Data System (ADS)

    Webber, Derek

    2013-12-01

    An argument was made at the First Arcachon Conference on Private Human Access to Space in 2008 [1] that some systematic market research should be conducted into potential market segments for point-to-point suborbital space transportation (PtP), in order to understand whether a commercial market exists which might augment possible government use for such a vehicle. The cargo market potential was subsequently addressed via desk research, and the results, which resulted in a pessimistic business case outlook, were presented in [2]. The same desk research approach is now used in this paper to address the potential business and wealthy individual passenger traveler market segment ("point-to-point people with purpose"). The results, with the assumed ticket pricing, are not encouraging.

  3. A study of coronal bright points at 20 cm wavelength

    NASA Technical Reports Server (NTRS)

    Nitta, N.; Kundu, M. R.

    1988-01-01

    The paper presents the results of a study of coronal bright points observed at 20 cm with the VLA on a day when the sun was exceptionally quiet. Microwave maps of bright points were obtained using data for the entire observing period of 5 hours, as well as for shorter periods of a few minutes. Most bright points, especially those appearing in the full-period maps, appear to be associated with small bipolar structures on the photospheric magnetogram. Overlays of bright point (BP) maps on the Ca(+) K picture, show that the brightest part of BP tends to lie on the boundary of a supergranulation network.

  4. An assessment of consistence of exhaust gas emission test results obtained under controlled NEDC conditions

    NASA Astrophysics Data System (ADS)

    Balawender, K.; Jaworski, A.; Kuszewski, H.; Lejda, K.; Ustrzycki, A.

    2016-09-01

    Measurements concerning emissions of pollutants contained in automobile combustion engine exhaust gases is of primary importance in view of their harmful impact on the natural environment. This paper presents results of tests aimed at determining exhaust gas pollutant emissions from a passenger car engine obtained under repeatable conditions on a chassis dynamometer. The test set-up was installed in a controlled climate chamber allowing to maintain the temperature conditions within the range from -20°C to +30°C. The analysis covered emissions of such components as CO, CO2, NOx, CH4, THC, and NMHC. The purpose of the study was to assess repeatability of results obtained in a number of tests performed as per NEDC test plan. The study is an introductory stage of a wider research project concerning the effect of climate conditions and fuel type on emission of pollutants contained in exhaust gases generated by automotive vehicles.

  5. Navigable points estimation for mobile robots using binary image skeletonization

    NASA Astrophysics Data System (ADS)

    Martinez S., Fernando; Jacinto G., Edwar; Montiel A., Holman

    2017-02-01

    This paper describes the use of image skeletonization for the estimation of all the navigable points, inside a scene of mobile robots navigation. Those points are used for computing a valid navigation path, using standard methods. The main idea is to find the middle and the extreme points of the obstacles in the scene, taking into account the robot size, and create a map of navigable points, in order to reduce the amount of information for the planning algorithm. Those points are located by means of the skeletonization of a binary image of the obstacles and the scene background, along with some other digital image processing algorithms. The proposed algorithm automatically gives a variable number of navigable points per obstacle, depending on the complexity of its shape. As well as, the way how the algorithm can change some of their parameters in order to change the final number of the resultant key points is shown. The results shown here were obtained applying different kinds of digital image processing algorithms on static scenes.

  6. Non-Gimbaled Antenna Pointing: Summary of Results and Analysis

    NASA Technical Reports Server (NTRS)

    Horan, Stephen

    1998-01-01

    There is considerable interest at this time in developing small satellites for quick-turnaround missions to investigate near-earth phenomena from space. One problem to be solved in mission planning is the means of communication between the control infrastructure in the ground segment and the satellite in the space segment. A nominal small-satellite mission design often includes an omni-directional or similar wide-pattern antenna on the satellite and a dedicated ground station for telemetry, tracking, and command support. These terminals typically provide up to 15 minutes of coverage during an orbit that is within the visibility of the ground station; however, not all orbits will pass over the ground station so that coverage gaps will exist in the data flow. To overcome this general limitation on data transmission for low-earth orbiting satellites, the Space Network (SN), operated by the National Aeronautics and Space Administration, (NASA) has been designed to transmit data to and from user satellites through the Tracking and Data Relay Satellites (TDRS) in geostationary orbit and interfacing to the White Sands Complex (WSC) in New Mexico for the data's ground entry point. The advantage of the SN over a fixed ground station is that all low-earth-satellite orbits will be within the visibility area of at least one TDRS within the SN for a large part of the orbit and the potential exists to establish a communications link if the user satellite can point an antenna in the direction of any one of the relay satellites. Within NASA, there is considerable interest in seeing that small satellite developers are aware of the advantages to the SN and that designs to include the SN are part of the satellite design. Small satellite users have not often considered using the SN because of: (1) The 26-dB link penalty differential between direct broadcast to a ground station and transmission through a TDRS to the ground; (2) The class of satellite is too small to support high

  7. Glucose Meters: A Review of Technical Challenges to Obtaining Accurate Results

    PubMed Central

    Tonyushkina, Ksenia; Nichols, James H.

    2009-01-01

    , anemia, hypotension, and other disease states. This article reviews the challenges involved in obtaining accurate glucose meter results. PMID:20144348

  8. Determination of the boiling-point distribution by simulated distillation from n-pentane through n-tetratetracontane in 70 to 80 seconds.

    PubMed

    Lubkowitz, Joaquin A; Meneghini, Roberto I

    2002-01-01

    This work presents the carrying out of boiling-point distributions by simulated distillation with direct-column heating rather than oven-column heating. Column-heating rates of 300 degrees C/min are obtained yielding retention times of 73 s for n-tetratetracontane. The calibration curves of the retention time versus the boiling point, in the range of n-pentane to n-tetratetracontane, are identical to those obtained by slower oven-heating rates. The boiling-point distribution of the reference gas oil is compared with that obtained with column oven heating at rates of 15 to 40 degrees C/min. The results show boiling-point distribution values nearly the same (1-2 degrees F) as those obtained with oven column heating from the initial boiling point to 80% distilled off. Slightly higher differences are obtained (3-4 degrees F) for the 80% distillation to final boiling-point interval. Nonetheless, allowed consensus differences are never exceeded. Precision of the boiling-point distributions (expressed as standard deviations) are 0.1-0.3% for the data obtained in the direct column-heating mode.

  9. Exact Identification of a Quantum Change Point

    NASA Astrophysics Data System (ADS)

    Sentís, Gael; Calsamiglia, John; Muñoz-Tapia, Ramon

    2017-10-01

    The detection of change points is a pivotal task in statistical analysis. In the quantum realm, it is a new primitive where one aims at identifying the point where a source that supposedly prepares a sequence of particles in identical quantum states starts preparing a mutated one. We obtain the optimal procedure to identify the change point with certainty—naturally at the price of having a certain probability of getting an inconclusive answer. We obtain the analytical form of the optimal probability of successful identification for any length of the particle sequence. We show that the conditional success probabilities of identifying each possible change point show an unexpected oscillatory behavior. We also discuss local (online) protocols and compare them with the optimal procedure.

  10. Exact Identification of a Quantum Change Point.

    PubMed

    Sentís, Gael; Calsamiglia, John; Muñoz-Tapia, Ramon

    2017-10-06

    The detection of change points is a pivotal task in statistical analysis. In the quantum realm, it is a new primitive where one aims at identifying the point where a source that supposedly prepares a sequence of particles in identical quantum states starts preparing a mutated one. We obtain the optimal procedure to identify the change point with certainty-naturally at the price of having a certain probability of getting an inconclusive answer. We obtain the analytical form of the optimal probability of successful identification for any length of the particle sequence. We show that the conditional success probabilities of identifying each possible change point show an unexpected oscillatory behavior. We also discuss local (online) protocols and compare them with the optimal procedure.

  11. Characterisation of Feature Points in Eye Fundus Images

    NASA Astrophysics Data System (ADS)

    Calvo, D.; Ortega, M.; Penedo, M. G.; Rouco, J.

    The retinal vessel tree adds decisive knowledge in the diagnosis of numerous opthalmologic pathologies such as hypertension or diabetes. One of the problems in the analysis of the retinal vessel tree is the lack of information in terms of vessels depth as the image acquisition usually leads to a 2D image. This situation provokes a scenario where two different vessels coinciding in a point could be interpreted as a vessel forking into a bifurcation. That is why, for traking and labelling the retinal vascular tree, bifurcations and crossovers of vessels are considered feature points. In this work a novel method for these retinal vessel tree feature points detection and classification is introduced. The method applies image techniques such as filters or thinning to obtain the adequate structure to detect the points and sets a classification of these points studying its environment. The methodology is tested using a standard database and the results show high classification capabilities.

  12. A new comparison method for dew-point generators

    NASA Astrophysics Data System (ADS)

    Heinonen, Martti

    1999-12-01

    A new method for comparing dew-point generators was developed at the Centre for Metrology and Accreditation. In this method, the generators participating in a comparison are compared with a transportable saturator unit using a dew-point comparator. The method was tested by constructing a test apparatus and by comparing it with the MIKES primary dew-point generator several times in the dew-point temperature range from -40 to +75 °C. The expanded uncertainty (k = 2) of the apparatus was estimated to be between 0.05 and 0.07 °C and the difference between the comparator system and the generator is well within these limits. In particular, all of the results obtained in the range below 0 °C are within ±0.03 °C. It is concluded that a new type of a transfer standard with characteristics most suitable for dew-point comparisons can be developed on the basis of the principles presented in this paper.

  13. Focal points and principal solutions of linear Hamiltonian systems revisited

    NASA Astrophysics Data System (ADS)

    Šepitka, Peter; Šimon Hilscher, Roman

    2018-05-01

    In this paper we present a novel view on the principal (and antiprincipal) solutions of linear Hamiltonian systems, as well as on the focal points of their conjoined bases. We present a new and unified theory of principal (and antiprincipal) solutions at a finite point and at infinity, and apply it to obtain new representation of the multiplicities of right and left proper focal points of conjoined bases. We show that these multiplicities can be characterized by the abnormality of the system in a neighborhood of the given point and by the rank of the associated T-matrix from the theory of principal (and antiprincipal) solutions. We also derive some additional important results concerning the representation of T-matrices and associated normalized conjoined bases. The results in this paper are new even for completely controllable linear Hamiltonian systems. We also discuss other potential applications of our main results, in particular in the singular Sturmian theory.

  14. Diffusion and binding analyzed with combined point FRAP and FCS.

    PubMed

    Im, Kang-Bin; Schmidt, Ute; Kang, Moon-Sik; Lee, Ji-Young; Bestvater, Felix; Wachsmuth, Malte

    2013-09-01

    To quantify more precisely and more reliably diffusion and reaction properties of biomolecules in living cells, a novel closed description in 3D of both the bleach and the post-bleach segment of fluorescence recovery after photobleaching (FRAP) data acquired at a point, i.e., a diffraction-limited observation area, termed point FRAP, is presented. It covers a complete coupled reaction-diffusion scheme for mobile molecules undergoing transient or long-term immobilization because of binding. We assess and confirm the feasibility with numerical solutions of the differential equations. By applying this model to free EYFP expressed in HeLa cells using a customized confocal laser scanning microscope that integrates point FRAP and fluorescence correlation spectroscopy (FCS), the applicability is validated by comparison with results from FCS. We show that by taking diffusion during bleaching into consideration and/or by employing a global analysis of series of bleach times, the results can be improved significantly. As the point FRAP approach allows to obtain data with diffraction-limited positioning accuracy, diffusion and binding properties of the exon-exon junction complex (EJC) components REF2-II and Magoh are obtained at different localizations in the nucleus of MCF7 cells and refine our view on the position-dependent association of the EJC factors with a maturating mRNP complex. Our findings corroborate the concept of combining point FRAP and FCS for a better understanding of the underlying diffusion and binding processes. Copyright © 2013 International Society for Advancement of Cytometry.

  15. Feature point based 3D tracking of multiple fish from multi-view images

    PubMed Central

    Qian, Zhi-Ming

    2017-01-01

    A feature point based method is proposed for tracking multiple fish in 3D space. First, a simplified representation of the object is realized through construction of two feature point models based on its appearance characteristics. After feature points are classified into occluded and non-occluded types, matching and association are performed, respectively. Finally, the object's motion trajectory in 3D space is obtained through integrating multi-view tracking results. Experimental results show that the proposed method can simultaneously track 3D motion trajectories for up to 10 fish accurately and robustly. PMID:28665966

  16. Feature point based 3D tracking of multiple fish from multi-view images.

    PubMed

    Qian, Zhi-Ming; Chen, Yan Qiu

    2017-01-01

    A feature point based method is proposed for tracking multiple fish in 3D space. First, a simplified representation of the object is realized through construction of two feature point models based on its appearance characteristics. After feature points are classified into occluded and non-occluded types, matching and association are performed, respectively. Finally, the object's motion trajectory in 3D space is obtained through integrating multi-view tracking results. Experimental results show that the proposed method can simultaneously track 3D motion trajectories for up to 10 fish accurately and robustly.

  17. Effect of Impurities on the Freezing Point of Zinc

    NASA Astrophysics Data System (ADS)

    Sun, Jianping; Rudtsch, Steffen; Niu, Yalu; Zhang, Lin; Wang, Wei; Den, Xiaolong

    2017-03-01

    The knowledge of the liquidus slope of impurities in fixed-point metal defined by the International Temperature Scale of 1990 is important for the estimation of uncertainties and correction of fixed point with the sum of individual estimates method. Great attentions are paid to the effect of ultra-trace impurities on the freezing point of zinc in the National Institute of Metrology. In the present work, the liquidus slopes of Ga-Zn, Ge-Zn were measured with the slim fixed-point cell developed through the doping experiments, and the temperature characteristics of the phase diagram of Fe-Zn were furthermore investigated. A quasi-adiabatic Zn fixed-point cell was developed with the thermometer well surrounded by the crucible with the pure metal, and the temperature uniformity of less than 20 mK in the region where the metal is located was obtained. The previous doping experiment of Pb-Zn with slim fixed-point cell was checked with quasi-adiabatic Zn fixed-point cell, and the result supports the previous liquidus slope measured with the traditional fixed-point realization.

  18. Airglow during ionospheric modifications by the sura facility radiation. experimental results obtained in 2010

    NASA Astrophysics Data System (ADS)

    Grach, S. M.; Klimenko, V. V.; Shindin, A. V.; Nasyrov, I. A.; Sergeev, E. N.; A. Yashnov, V.; A. Pogorelko, N.

    2012-06-01

    We present the results of studying the structure and dynamics of the HF-heated volume above the Sura facility obtained in 2010 by measurements of ionospheric airglow in the red (λ = 630 nm) and green (λ = 557.7 nm) lines of atomic oxygen. Vertical sounding of the ionosphere (followed by modeling of the pump-wave propagation) and measurements of stimulated electromagnetic emission were used for additional diagnostics of ionospheric parameters and the processes occurring in the heated volume.

  19. Wire Array Z-pinches on Sphinx Machine: Experimental Results and Relevant Points of Microsecond Implosion Physics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Calamy, H.; Hamann, F.; Lassalle, F.

    Centre d'Etudes de Gramat (France) has developed an efficient long implosion time (800 ns) Aluminum plasma radiation source (PRS). Based on the LTD technology, the SPHINX facility is developed as a 1-3MJ, 1{mu}s rise time, 4-10 MA current driver. In this paper, it was used in 1MJ, 4MA configuration to drive Aluminum nested wire arrays Z-pinches with K-shell yield up to 20 kJ and a FWHM of the x-ray pulse of about 50 ns. We present latest SPHINX experiments and some of the main physic issues of the microsecond regime. Experimental setup and results are described with the aim ofmore » giving trends that have been obtained. The main features of microsecond implosion of wire arrays can be analyzed thanks to same methods and theories as used for faster Z-pinches. The effect of load polarity was examined. The stability of the implosion , one of the critical point of microsecond wire arrays due to the load dimensions imposed by the time scale, is tackled. A simple scaling from 100 ns Z-pinch results to 800 ns ones gives good results and the use of nested arrays improves dramatically the implosion quality and the Kshell yield of the load. However, additional effects such as the impact of the return current can geometry on the implosion have to be taken into account on our loads. Axial inhomogeneity of the implosion the origin of which is not yet well understood occurs in some shots and impacts the radiation output. The shape of the radiative pulse is discussed and compared with the homogeneity of the implosion. Numerical 2D R-Z and R-{theta} simulations are used to highlight some experimental results and understand the plasma conditions during these microsecond wire arrays implosions.« less

  20. Wire Array Z-pinches on Sphinx Machine: Experimental Results and Relevant Points of Microsecond Implosion Physics

    NASA Astrophysics Data System (ADS)

    Calamy, H.; Hamann, F.; Lassalle, F.; Bayol, F.; Mangeant, C.; Morell, A.; Huet, D.; Bedoch, J. P.; Chittenden, J. P.; Lebedev, S. V.; Jennings, C. A.; Bland, S. N.

    2006-01-01

    Centre d'Etudes de Gramat (France) has developed an efficient long implosion time (800 ns) Aluminum plasma radiation source (PRS). Based on the LTD technology, the SPHINX facility is developed as a 1-3MJ, 1μs rise time, 4-10 MA current driver. In this paper, it was used in 1MJ, 4MA configuration to drive Aluminum nested wire arrays Z-pinches with K-shell yield up to 20 kJ and a FWHM of the x-ray pulse of about 50 ns. We present latest SPHINX experiments and some of the main physic issues of the microsecond regime. Experimental setup and results are described with the aim of giving trends that have been obtained. The main features of microsecond implosion of wire arrays can be analyzed thanks to same methods and theories as used for faster Z-pinches. The effect of load polarity was examined. The stability of the implosion , one of the critical point of microsecond wire arrays due to the load dimensions imposed by the time scale, is tackled. A simple scaling from 100 ns Z-pinch results to 800 ns ones gives good results and the use of nested arrays improves dramatically the implosion quality and the Kshell yield of the load. However, additional effects such as the impact of the return current can geometry on the implosion have to be taken into account on our loads. Axial inhomogeneity of the implosion the origin of which is not yet well understood occurs in some shots and impacts the radiation output. The shape of the radiative pulse is discussed and compared with the homogeneity of the implosion. Numerical 2D R-Z and R-θ simulations are used to highlight some experimental results and understand the plasma conditions during these microsecond wire arrays implosions.

  1. Summer performance results obtained from simultaneously testing ten solar collectors outdoors

    NASA Technical Reports Server (NTRS)

    Miller, D. R.

    1977-01-01

    Ten solar collectors were simultaneously tested outdoors. Efficiency data were correlated using a method that separates solar variables (flux, incident angle) from the desired performance parameters (heat loss, absorbtance, transmittance) which are unique to a given collector design. Tests were conducted on both clear and moderately cloudy days. Correlating data in the above manner, a 2-glass, black paint collector exhibited a decrease in efficiency of 5 percentage points relative to the baseline data for an exposure time of 2 years, 4 months. Condensation on the collector glazing was thought to be a contributing factor in this efficiency change.

  2. On-line noninvasive one-point measurements of pulse wave velocity.

    PubMed

    Harada, Akimitsu; Okada, Takashi; Niki, Kiyomi; Chang, Dehua; Sugawara, Motoaki

    2002-12-01

    Pulse wave velocity (PWV) is a basic parameter in the dynamics of pressure and flow waves traveling in arteries. Conventional on-line methods of measuring PWV have mainly been based on "two-point" measurements, i.e., measurements of the time of travel of the wave over a known distance. This paper describes two methods by which on-line "one-point" measurements can be made, and compares the results obtained by the two methods. The principle of one method is to measure blood pressure and velocity at a point, and use the water-hammer equation for forward traveling waves. The principle of the other method is to derive PWV from the stiffness parameter of the artery. Both methods were realized by using an ultrasonic system which we specially developed for noninvasive measurements of wave intensity. We applied the methods to the common carotid artery in 13 normal humans. The regression line of the PWV (m/s) obtained by the former method on the PWV (m/s) obtained by the latter method was y = 1.03x - 0.899 (R(2) = 0.83). Although regional PWV in the human carotid artery has not been reported so far, the correlation between the PWVs obtained by the present two methods was so high that we are convinced of the validity of these methods.

  3. NULL Convention Floating Point Multiplier

    PubMed Central

    Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation. PMID:25879069

  4. NULL convention floating point multiplier.

    PubMed

    Albert, Anitha Juliette; Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation.

  5. Line of sight pointing technology for laser communication system between aircrafts

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Liu, Yunqing; Song, Yansong

    2017-12-01

    In space optical communications, it is important to obtain the most efficient performance of line of sight (LOS) pointing system. The errors of position (latitude, longitude, and altitude), attitude angles (pitch, yaw, and roll), and installation angle among a different coordinates system are usually ineluctable when assembling and running an aircraft optical communication terminal. These errors would lead to pointing errors and make it difficult for the LOS system to point to its terminal to establish a communication link. The LOS pointing technology of an aircraft optical communication system has been researched using a transformation matrix between the coordinate systems of two aircraft terminals. A method of LOS calibration has been proposed to reduce the pointing error. In a flight test, a successful 144-km link was established between two aircrafts. The position and attitude angles of the aircraft have been obtained to calculate the pointing angle in azimuth and elevation provided by using a double-antenna GPS/INS system. The size of the field of uncertainty (FOU) and the pointing accuracy are analyzed based on error theory, and it has been also measured using an observation camera installed next to the optical LOS. Our results show that the FOU of aircraft optical communications is 10 mrad without a filter, which is the foundation to acquisition strategy and scanning time.

  6. Performance of Mercury Triple-Point Cells Made in Brazil

    NASA Astrophysics Data System (ADS)

    Petkovic, S. G.; Santiago, J. F. N.; Filho, R. R.; Teixeira, R. N.; Santos, P. R. F.

    2003-09-01

    Fixed-points cells are primary standards in ITS-90. They contain reference material with a purity of 99.999 % or more. The gallium in a melting-point cell, for example, can reach a purity of 99.99999 %. This level of purity is not easy to obtain. However, substances like water and mercury can be purified by means of distillation and chemical procedures. This paper presents the results of mercury triple-point cells made in Brazil that were directly compared to a mercury triple-point cell of 99.999% purity. This reference cell, made by Isotech (England), was previously compared to cells from CENAM (Mexico) and NRC (Canada) and the maximum deviation found was approximately 0.4 mK. The purification stage started with a sample of mercury 99.3 % pure, and the repeated use of both mechanical and chemical processes led to a purification grade considered good enough for calibration of standard platinum resistance thermometers. The purification procedures, the method of construction of the cell, the laboratory facilities, the comparison results and the budget of uncertainties are described in this paper. All of the cells tested have a triple-point temperature within 0.25 mK of the triple-point temperature of the Inmetro reference cell.

  7. Approximate Model for Turbulent Stagnation Point Flow.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dechant, Lawrence

    2016-01-01

    Here we derive an approximate turbulent self-similar model for a class of favorable pressure gradient wedge-like flows, focusing on the stagnation point limit. While the self-similar model provides a useful gross flow field estimate this approach must be combined with a near wall model is to determine skin friction and by Reynolds analogy the heat transfer coefficient. The combined approach is developed in detail for the stagnation point flow problem where turbulent skin friction and Nusselt number results are obtained. Comparison to the classical Van Driest (1958) result suggests overall reasonable agreement. Though the model is only valid near themore » stagnation region of cylinders and spheres it nonetheless provides a reasonable model for overall cylinder and sphere heat transfer. The enhancement effect of free stream turbulence upon the laminar flow is used to derive a similar expression which is valid for turbulent flow. Examination of free stream enhanced laminar flow suggests that the rather than enhancement of a laminar flow behavior free stream disturbance results in early transition to turbulent stagnation point behavior. Excellent agreement is shown between enhanced laminar flow and turbulent flow behavior for high levels, e.g. 5% of free stream turbulence. Finally the blunt body turbulent stagnation results are shown to provide realistic heat transfer results for turbulent jet impingement problems.« less

  8. Study on Huizhou architecture of point cloud registration based on optimized ICP algorithm

    NASA Astrophysics Data System (ADS)

    Zhang, Runmei; Wu, Yulu; Zhang, Guangbin; Zhou, Wei; Tao, Yuqian

    2018-03-01

    In view of the current point cloud registration software has high hardware requirements, heavy workload and moltiple interactive definition, the source of software with better processing effect is not open, a two--step registration method based on normal vector distribution feature and coarse feature based iterative closest point (ICP) algorithm is proposed in this paper. This method combines fast point feature histogram (FPFH) algorithm, define the adjacency region of point cloud and the calculation model of the distribution of normal vectors, setting up the local coordinate system for each key point, and obtaining the transformation matrix to finish rough registration, the rough registration results of two stations are accurately registered by using the ICP algorithm. Experimental results show that, compared with the traditional ICP algorithm, the method used in this paper has obvious time and precision advantages for large amount of point clouds.

  9. Higher-order triangular spectral element method with optimized cubature points for seismic wavefield modeling

    NASA Astrophysics Data System (ADS)

    Liu, Youshan; Teng, Jiwen; Xu, Tao; Badal, José

    2017-05-01

    The mass-lumped method avoids the cost of inverting the mass matrix and simultaneously maintains spatial accuracy by adopting additional interior integration points, known as cubature points. To date, such points are only known analytically in tensor domains, such as quadrilateral or hexahedral elements. Thus, the diagonal-mass-matrix spectral element method (SEM) in non-tensor domains always relies on numerically computed interpolation points or quadrature points. However, only the cubature points for degrees 1 to 6 are known, which is the reason that we have developed a p-norm-based optimization algorithm to obtain higher-order cubature points. In this way, we obtain and tabulate new cubature points with all positive integration weights for degrees 7 to 9. The dispersion analysis illustrates that the dispersion relation determined from the new optimized cubature points is comparable to that of the mass and stiffness matrices obtained by exact integration. Simultaneously, the Lebesgue constant for the new optimized cubature points indicates its surprisingly good interpolation properties. As a result, such points provide both good interpolation properties and integration accuracy. The Courant-Friedrichs-Lewy (CFL) numbers are tabulated for the conventional Fekete-based triangular spectral element (TSEM), the TSEM with exact integration, and the optimized cubature-based TSEM (OTSEM). A complementary study demonstrates the spectral convergence of the OTSEM. A numerical example conducted on a half-space model demonstrates that the OTSEM improves the accuracy by approximately one order of magnitude compared to the conventional Fekete-based TSEM. In particular, the accuracy of the 7th-order OTSEM is even higher than that of the 14th-order Fekete-based TSEM. Furthermore, the OTSEM produces a result that can compete in accuracy with the quadrilateral SEM (QSEM). The high accuracy of the OTSEM is also tested with a non-flat topography model. In terms of computational

  10. Inflection point in running kinetic term inflation

    NASA Astrophysics Data System (ADS)

    Gao, Tie-Jun; Xiu, Wu-Tao; Yang, Xiu-Yi

    2017-04-01

    In this work, we calculate the general form of the scalar potential with polynomial superpotential in the framework of running kinetic term inflation, then focus on a polynomial superpotential with two terms and obtain the inflection point inflationary model. We study the inflationary dynamics and show that the predicted value of the scalar spectral index and tensor-to-scalar ratio can lie within the 1σ confidence region allowed by the result of Planck 2015.

  11. Impact of ambiguity resolution and application of transformation parameters obtained by regional GNSS network in Precise Point Positioning

    NASA Astrophysics Data System (ADS)

    Gandolfi, S.; Poluzzi, L.; Tavasci, L.

    2012-12-01

    Precise Point Positioning (PPP) is one of the possible approaches for GNSS data processing. As known this technique is faster and more flexible compared to the others which are based on a differenced approach and constitute a reliable methods for accurate positioning of remote GNSS stations, even in some remote area such as Antarctica. Until few years ago one of the major limits of the method was the impossibility to resolve the ambiguity as integer but nowadays many methods are available to resolve this aspect. The first software package permitting a PPP solution was the GIPSY OASIS realized, developed and maintained by JPL (NASA). JPL produce also orbits and files ready to be used with GIPSY. Recently, using these products came possible to resolve ambiguities improving the stability of solutions. PPP permit to estimate position into the reference frame of the orbits (IGS) and when coordinate in others reference frames, such al ITRF, are needed is necessary to apply a transformation. Within his products JPL offer, for each day, a global 7 parameter transformation that permit to locate the survey into the ITRF RF. In some cases it's also possible to create a costumed process and obtain analogous parameters using local/regional reference network of stations which coordinates are available also in the desired reference frame. In this work some tests on accuracy has been carried out comparing different PPP solutions obtained using the same software packages (GIPSY) but considering the ambiguity resolution, the global and regional transformation parameters. In particular two test area have been considered, first one located in Antarctica and the second one in Italy. Aim of the work is the evaluation of the impact of ambiguity resolution and the use of local/regional transformation parameter in the final solutions. Tests shown how the ambiguity resolution improve the precision, especially in the EAST component with a scattering reduction about 8%. And the use of global

  12. Do Owners Have a Clever Hans Effect on Dogs? Results of a Pointing Study

    PubMed Central

    Schmidjell, Teresa; Range, Friederike; Huber, Ludwig; Virányi, Zsófia

    2012-01-01

    Dogs are exceptionally successful at interpreting human pointing gestures to locate food hidden in one of two containers. However, it has repeatedly been questioned whether dogs rely on the pointing gesture or their success is increased by subtle cues from their human handler. In two experiments we used a standard two-way object-choice task to focus on this potential Clever Hans effect. We investigated if and how owners’ knowledge and beliefs influenced their dogs’ performance. In two experiments, as is typical in such pointing tasks, the owners sat behind their dogs, in close auditory and tactile contact with them. In Experiment 1, we systematically manipulated the owners’ knowledge of whether or not their dog should follow the pointing gesture, but at the same time instructed the owners to refrain from influencing the choice of their dog. We found no influence of subtle cues from the owners, if indeed they existed: dogs in the different groups followed the pointing uniformly. Furthermore, in the absence of pointing dogs chose randomly, even though the owners had been informed about the location of the reward. In Experiment 2, owners were instructed to actively influence the choice of their dogs, and they, indeed, succeeded in sending their dogs to the container they believed to be baited. However, their influence was significantly weaker if the experimenter had previously pointed to the other location. Overall the pointing gesture seems to have a strong effect on the choice of dogs in an object-choice task. Pointing can lead the dogs to success without help from their owners as well as it can counteract clear directional instructions provided by the owners. PMID:23272000

  13. Monitoring changes of optical attenuation coefficients of acupuncture points during laser acupuncture by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Huang, Yimei; Yang, Hongqin; Wang, Yuhua; Zheng, Liqin; Xie, Shusen

    2010-11-01

    The physical properties of acupuncture point were important to discover the mechanism of acupuncture meridian. In this paper, we used an optical coherence tomography to monitor in vivo the changes of optical attenuation coefficients of Hegu acupuncture point and non-acupuncture point during laser irradiation on Yangxi acupuncture point. The optical attenuation coefficients of Hegu acupuncture point and non-acupuncture point were obtained by fitting the raw data according to the Beer-Lambert's law. The experimental results showed that the optical attenuation coefficient of Hegu acupuncture point decreased during the laser acupuncture, in contrast to a barely changed result in that of non-acupuncture point. The significant change of optical attenuation coefficient of Hegu acupuncture point indicated that there was a correlation between Hegu and Yangxi acupuncture points to some extent.

  14. A Kinematically Consistent Two-Point Correlation Function

    NASA Technical Reports Server (NTRS)

    Ristorcelli, J. R.

    1998-01-01

    A simple kinematically consistent expression for the longitudinal two-point correlation function related to both the integral length scale and the Taylor microscale is obtained. On the inner scale, in a region of width inversely proportional to the turbulent Reynolds number, the function has the appropriate curvature at the origin. The expression for two-point correlation is related to the nonlinear cascade rate, or dissipation epsilon, a quantity that is carried as part of a typical single-point turbulence closure simulation. Constructing an expression for the two-point correlation whose curvature at the origin is the Taylor microscale incorporates one of the fundamental quantities characterizing turbulence, epsilon, into a model for the two-point correlation function. The integral of the function also gives, as is required, an outer integral length scale of the turbulence independent of viscosity. The proposed expression is obtained by kinematic arguments; the intention is to produce a practically applicable expression in terms of simple elementary functions that allow an analytical evaluation, by asymptotic methods, of diverse functionals relevant to single-point turbulence closures. Using the expression devised an example of the asymptotic method by which functionals of the two-point correlation can be evaluated is given.

  15. Research on relation between cortical functional section and acupuncture point

    NASA Astrophysics Data System (ADS)

    Chen, Shuwang; Li, Chunhua; Liang, Guozhuang; Wang, Shuhai

    2008-02-01

    The application of the infrared imaging using in the brain cognition and the acupuncture is introduced. Acupuncturing a certain point of the healthy experimental cats, observing the responds of the cerebral cortical temperature by using of infrared imaging, and researching the corresponding relation between the acupuncture points with the active sections of the cerebral cortex, so the effect of the acupuncture is obtained. The theory of the refreshment and induce resuscitation pinprick is approved. The method of the "refreshment and induce resuscitation pinprick" can promote the metabolize renovation, improve the living function and increase the healing rate. However, the relations between the points and the cortical functional sections have not the last word still. After removing the skulls on the head, full of the cerebral cortex of a cat are exposed. Observing the infrared imaging and measuring the temperatures of the visual cerebral cortex during the process of acupuncturing the points to judge the activation position. During the process of acupuncture, the trend of the rising temperature on cerebral cortex is primary in terms of the phenomena in the infrared pictures. The cortical hemogram variety is measured in terms of the infrared pictures and the temperature values, so the characteristic curve of the temperature for a corresponding position on the cerebral cortex and the acupuncture point can be obtained. When the acupuncture point is changed, the position where temperature varied on cerebral cortex is different correspondingly. The variety in the cortical functional sections is corresponding to the result of the acupuncture point in terms of the imaging and the temperatures. The experimental results accord with the theoretic model, so they validate the correctness of the "refreshment and induce resuscitation pinprick". According to the experimental results, we know that the variety of a cortical functional section is corresponding to a special acupuncture

  16. Orbit Determination (OD) Error Analysis Results for the Triana Sun-Earth L1 Libration Point Mission and for the Fourier Kelvin Stellar Interferometer (FKSI) Sun-Earth L2 Libration Point Mission Concept

    NASA Technical Reports Server (NTRS)

    Marr, Greg C.

    2003-01-01

    The Triana spacecraft was designed to be launched by the Space Shuttle. The nominal Triana mission orbit will be a Sun-Earth L1 libration point orbit. Using the NASA Goddard Space Flight Center's Orbit Determination Error Analysis System (ODEAS), orbit determination (OD) error analysis results are presented for all phases of the Triana mission from the first correction maneuver through approximately launch plus 6 months. Results are also presented for the science data collection phase of the Fourier Kelvin Stellar Interferometer Sun-Earth L2 libration point mission concept with momentum unloading thrust perturbations during the tracking arc. The Triana analysis includes extensive analysis of an initial short arc orbit determination solution and results using both Deep Space Network (DSN) and commercial Universal Space Network (USN) statistics. These results could be utilized in support of future Sun-Earth libration point missions.

  17. Some new results on charged compact boson stars

    DOE PAGES

    Kumar, Sanjeev; Kulshreshtha, Usha; Kulshreshtha, Daya Shankar; ...

    2017-07-21

    In this work we present some new results obtained in a study of the phase diagram of charged compact boson stars in a theory involving a complex scalar field with a conical potential coupled to a U(1) gauge field and gravity. We here obtain new bifurcation points in this model. We present a detailed discussion of the various regions of the phase diagram with respect to the bifurcation points. The theory is seen to contain rich physics in a particular domain of the phase diagram.

  18. FPFH-based graph matching for 3D point cloud registration

    NASA Astrophysics Data System (ADS)

    Zhao, Jiapeng; Li, Chen; Tian, Lihua; Zhu, Jihua

    2018-04-01

    Correspondence detection is a vital step in point cloud registration and it can help getting a reliable initial alignment. In this paper, we put forward an advanced point feature-based graph matching algorithm to solve the initial alignment problem of rigid 3D point cloud registration with partial overlap. Specifically, Fast Point Feature Histograms are used to determine the initial possible correspondences firstly. Next, a new objective function is provided to make the graph matching more suitable for partially overlapping point cloud. The objective function is optimized by the simulated annealing algorithm for final group of correct correspondences. Finally, we present a novel set partitioning method which can transform the NP-hard optimization problem into a O(n3)-solvable one. Experiments on the Stanford and UWA public data sets indicates that our method can obtain better result in terms of both accuracy and time cost compared with other point cloud registration methods.

  19. Point-cloud-to-point-cloud technique on tool calibration for dental implant surgical path tracking

    NASA Astrophysics Data System (ADS)

    Lorsakul, Auranuch; Suthakorn, Jackrit; Sinthanayothin, Chanjira

    2008-03-01

    Dental implant is one of the most popular methods of tooth root replacement used in prosthetic dentistry. Computerize navigation system on a pre-surgical plan is offered to minimize potential risk of damage to critical anatomic structures of patients. Dental tool tip calibrating is basically an important procedure of intraoperative surgery to determine the relation between the hand-piece tool tip and hand-piece's markers. With the transferring coordinates from preoperative CT data to reality, this parameter is a part of components in typical registration problem. It is a part of navigation system which will be developed for further integration. A high accuracy is required, and this relation is arranged by point-cloud-to-point-cloud rigid transformations and singular value decomposition (SVD) for minimizing rigid registration errors. In earlier studies, commercial surgical navigation systems from, such as, BrainLAB and Materialize, have flexibility problem on tool tip calibration. Their systems either require a special tool tip calibration device or are unable to change the different tool. The proposed procedure is to use the pointing device or hand-piece to touch on the pivot and the transformation matrix. This matrix is calculated every time when it moves to the new position while the tool tip stays at the same point. The experiment acquired on the information of tracking device, image acquisition and image processing algorithms. The key success is that point-to-point-cloud requires only 3 post images of tool to be able to converge to the minimum errors 0.77%, and the obtained result is correct in using the tool holder to track the path simulation line displayed in graphic animation.

  20. Symbiotic organisms search algorithm for dynamic economic dispatch with valve-point effects

    NASA Astrophysics Data System (ADS)

    Sonmez, Yusuf; Kahraman, H. Tolga; Dosoglu, M. Kenan; Guvenc, Ugur; Duman, Serhat

    2017-05-01

    In this study, symbiotic organisms search (SOS) algorithm is proposed to solve the dynamic economic dispatch with valve-point effects problem, which is one of the most important problems of the modern power system. Some practical constraints like valve-point effects, ramp rate limits and prohibited operating zones have been considered as solutions. Proposed algorithm was tested on five different test cases in 5 units, 10 units and 13 units systems. The obtained results have been compared with other well-known metaheuristic methods reported before. Results show that proposed algorithm has a good convergence and produces better results than other methods.

  1. Wavelength dependence in radio-wave scattering and specular-point theory

    NASA Technical Reports Server (NTRS)

    Tyler, G. L.

    1976-01-01

    Radio-wave scattering from natural surfaces contains a strong quasispecular component that at fixed wavelengths is consistent with specular-point theory, but often has a strong wavelength dependence that is not predicted by physical optics calculations under the usual limitations of specular-point models. Wavelength dependence can be introduced by a physical approximation that preserves the specular-point assumptions with respect to the radii of curvature of a fictitious, effective scattering surface obtained by smoothing the actual surface. A uniform low-pass filter model of the scattering process yields explicit results for the effective surface roughness versus wavelength. Interpretation of experimental results from planetary surfaces indicates that the asymptotic surface height spectral densities fall at least as fast as an inverse cube of spatial frequency. Asymptotic spectral densities for Mars and portions of the lunar surface evidently decrease more rapidly.

  2. Alternative Methods for Estimating Plane Parameters Based on a Point Cloud

    NASA Astrophysics Data System (ADS)

    Stryczek, Roman

    2017-12-01

    Non-contact measurement techniques carried out using triangulation optical sensors are increasingly popular in measurements with the use of industrial robots directly on production lines. The result of such measurements is often a cloud of measurement points that is characterized by considerable measuring noise, presence of a number of points that differ from the reference model, and excessive errors that must be eliminated from the analysis. To obtain vector information points contained in the cloud that describe reference models, the data obtained during a measurement should be subjected to appropriate processing operations. The present paperwork presents an analysis of suitability of methods known as RANdom Sample Consensus (RANSAC), Monte Carlo Method (MCM), and Particle Swarm Optimization (PSO) for the extraction of the reference model. The effectiveness of the tested methods is illustrated by examples of measurement of the height of an object and the angle of a plane, which were made on the basis of experiments carried out at workshop conditions.

  3. Optimization of the parameters for obtaining zirconia-alumina coatings, made by flame spraying from results of numerical simulation

    NASA Astrophysics Data System (ADS)

    Ferrer, M.; Vargas, F.; Peña, G.

    2017-12-01

    The K-Sommerfeld values (K) and the melting percentage (% F) obtained by numerical simulation using the Jets et Poudres software were used to find the projection parameters of zirconia-alumina coatings by thermal spraying flame, in order to obtain coatings with good morphological and structural properties to be used as thermal insulation. The experimental results show the relationship between the Sommerfeld parameter and the porosity of the zirconia-alumina coatings. It is found that the lowest porosity is obtained when the K-Sommerfeld value is close to 45 with an oxidant flame, on the contrary, when superoxidant flames are used K values are close 52, which improve wear resistance.

  4. Description and primary results of Total Solar Irradiance Monitor, a solar-pointing instrument on an Earth observing satellite

    NASA Astrophysics Data System (ADS)

    Wang, Hongrui; Fang, Wei; Li, Huiduan

    2015-04-01

    Solar driving mechanism for Earth climate has been a controversial problem for centuries. Long-time data of solar activity is required by the investigations of the solar driving mechanism, such as Total Solar Irradiance (TSI) record. Three Total Solar Irradiance Monitors (TSIM) have been developed by Changchun Institute of Optics, Fine Mechanics and Physics for China Meteorological Administration to maintain continuities of TSI data series which lasted for nearly 4 decades.The newest TSIM has recorded TSI daily with accurate solar pointing on the FY-3C meteorological satellite since Oct 2013. TSIM/FY-3C has a pointing system for automatic solar tracking, onboard the satellite designed mainly for Earth observing. Most payloads of FY-3C are developed for observation of land, ocean and atmosphere. Consequently, the FY-3C satellite is a nadir-pointing spacecraft with its z axis to be pointed at the center of the Earth. Previous TSIMs onboard the FY-3A and FY-3B satellites had no pointing system, solar observations were only performed when the sun swept through field-of-view of the instruments. And TSI measurements are influenced inevitably by the solar pointing errors. Corrections of the solar pointing errors were complex. The problem is now removed by TSIM/FY-3C.TSIM/FY-3C follows the sun accurately by itself using its pointing system based on scheme of visual servo control. The pointing system is consisted of a radiometer package, two motors for solar tracking, a sun sensor and etc. TSIM/FY-3C has made daily observations of TSI for more than one year, with nearly zero solar pointing errors. Short time-scale variations in TSI detected by TSIM/FY-3C are nearly the same with VIRGO/SOHO and TIM/SORCE.Instrument details, primary results of solar pointing control, solar observations and etc will be given in the presentation.

  5. An approach of point cloud denoising based on improved bilateral filtering

    NASA Astrophysics Data System (ADS)

    Zheng, Zeling; Jia, Songmin; Zhang, Guoliang; Li, Xiuzhi; Zhang, Xiangyin

    2018-04-01

    An omnidirectional mobile platform is designed for building point cloud based on an improved filtering algorithm which is employed to handle the depth image. First, the mobile platform can move flexibly and the control interface is convenient to control. Then, because the traditional bilateral filtering algorithm is time-consuming and inefficient, a novel method is proposed which called local bilateral filtering (LBF). LBF is applied to process depth image obtained by the Kinect sensor. The results show that the effect of removing noise is improved comparing with the bilateral filtering. In the condition of off-line, the color images and processed images are used to build point clouds. Finally, experimental results demonstrate that our method improves the speed of processing time of depth image and the effect of point cloud which has been built.

  6. One-point functions in defect CFT and integrability

    NASA Astrophysics Data System (ADS)

    de Leeuw, Marius; Kristjansen, Charlotte; Zarembo, Konstantin

    2015-08-01

    We calculate planar tree level one-point functions of non-protected operators in the defect conformal field theory dual to the D3-D5 brane system with k units of the world volume flux. Working in the operator basis of Bethe eigenstates of the Heisenberg XXX 1/2 spin chain we express the one-point functions as overlaps of these eigenstates with a matrix product state. For k = 2 we obtain a closed expression of determinant form for any number of excitations, and in the case of half-filling we find a relation with the Néel state. In addition, we present a number of results for the limiting case k → ∞.

  7. Using a focal-plane array to estimate antenna pointing errors

    NASA Technical Reports Server (NTRS)

    Zohar, S.; Vilnrotter, V. A.

    1991-01-01

    The use of extra collecting horns in the focal plane of an antenna as a means of determining the Direction of Arrival (DOA) of the signal impinging on it, provided it is within the antenna beam, is considered. Our analysis yields a relatively simple algorithm to extract the DOA from the horns' outputs. An algorithm which, in effect, measures the thermal noise of the horns' signals and determines its effect on the uncertainty of the extracted DOA parameters is developed. Both algorithms were implemented in software and tested in simulated data. Based on these tests, it is concluded that this is a viable approach to the DOA determination. Though the results obtained are of general applicability, the particular motivation for the present work is their application to the pointing of a mechanically deformed antenna. It is anticipated that the pointing algorithm developed for a deformed antenna could be obtained as a small perturbation of the algorithm developed for an undeformed antenna. In this context, it should be pointed out that, with a deformed antenna, the array of horns and its associated circuitry constitute the main part of the deformation-compensation system. In this case, the pointing system proposed may be viewed as an additional task carried out by the deformation-compensation hardware.

  8. High-precision pointing with the Sardinia Radio Telescope

    NASA Astrophysics Data System (ADS)

    Poppi, Sergio; Pernechele, Claudio; Pisanu, Tonino; Morsiani, Marco

    2010-07-01

    We present here the systems aimed to measure and minimize the pointing errors for the Sardinia Radio Telescope: they consist of an optical telescope to measure errors due to the mechanical structure deformations and a lasers system for the errors due to the subreflector displacement. We show here the results of the tests that we have done on the Medicina 32 meters VLBI radio telescope. The measurements demonstrate we can measure the pointing errors of the mechanical structure, with an accuracy of about ~1 arcsec. Moreover, we show the technique to measure the displacement of the subreflector, placed in the SRT at 22 meters from the main mirror, within +/-0.1 mm from its optimal position. These measurements show that we can obtain the needed accuracy to correct also the non repeatable pointing errors, which arise on time scale varying from seconds to minutes.

  9. On two special values of temperature factor in hypersonic flow stagnation point

    NASA Astrophysics Data System (ADS)

    Bilchenko, G. G.; Bilchenko, N. G.

    2018-03-01

    The hypersonic aircraft permeable cylindrical and spherical surfaces laminar boundary layer heat and mass transfer control mathematical model properties are investigated. The nonlinear algebraic equations systems are obtained for two special values of temperature factor in the hypersonic flow stagnation point. The mappings bijectivity between heat and mass transfer local parameters and controls is established. The computation experiments results are presented: the domains of allowed values “heat-friction” are obtained.

  10. Automated Point Cloud Correspondence Detection for Underwater Mapping Using AUVs

    NASA Technical Reports Server (NTRS)

    Hammond, Marcus; Clark, Ashley; Mahajan, Aditya; Sharma, Sumant; Rock, Stephen

    2015-01-01

    An algorithm for automating correspondence detection between point clouds composed of multibeam sonar data is presented. This allows accurate initialization for point cloud alignment techniques even in cases where accurate inertial navigation is not available, such as iceberg profiling or vehicles with low-grade inertial navigation systems. Techniques from computer vision literature are used to extract, label, and match keypoints between "pseudo-images" generated from these point clouds. Image matches are refined using RANSAC and information about the vehicle trajectory. The resulting correspondences can be used to initialize an iterative closest point (ICP) registration algorithm to estimate accumulated navigation error and aid in the creation of accurate, self-consistent maps. The results presented use multibeam sonar data obtained from multiple overlapping passes of an underwater canyon in Monterey Bay, California. Using strict matching criteria, the method detects 23 between-swath correspondence events in a set of 155 pseudo-images with zero false positives. Using less conservative matching criteria doubles the number of matches but introduces several false positive matches as well. Heuristics based on known vehicle trajectory information are used to eliminate these.

  11. Ideal tibial intramedullary nail insertion point varies with tibial rotation.

    PubMed

    Walker, Richard M; Zdero, Rad; McKee, Michael D; Waddell, James P; Schemitsch, Emil H

    2011-12-01

    The aim of the study was to investigate how superior entry point varies with tibial rotation and to identify landmarks that can be used to identify suitable radiographs for successful intramedullary nail insertion. The proximal tibia and knee were imaged for 12 cadaveric limbs undergoing 5° increments of internal and external rotation. Medial and lateral arthrotomies were performed, the ideal superior entry point was identified, and a 2-mm Kirschner wire inserted. A second Kirschner wire was sequentially placed at the 5-mm and then the 10-mm position, both medial and lateral to the initial Kirschner wire. Radiographs of the knee were obtained for all increments. The changing position of the ideal nail insertion point was recorded. A 30° arc (range, 25°-40°) provided a suitable anteroposterior radiograph. On the neutral anteroposterior radiograph, the Kirschner wire was 54% ± 1.5% (range, 51-56%) from the medial edge of the tibial plateau. For every 5° of rotation, the Kirschner wire moved 3% of the plateau width. During external rotation, a misleading medial entry point was obtained. A fibular bisector line correlated with an entry point that was ideal or up to 5 mm lateral to this but never medial. The film that best showed the fibular bisector line was between 0° and 10° of internal rotation of the tibia. The fibula head bisector line can be used to avoid choosing external rotation views and, thus, avoid medial insertion points. The current results may help the surgeon prevent malalignment during intramedullary nailing in proximal tibial fractures.

  12. Individual flight styles in ski jumping: results obtained during Olympic Games competitions.

    PubMed

    Schmölzer, B; Müller, W

    2005-05-01

    From the physics point of view, the jump length in ski jumping depends on: the in-run velocity v(0), the velocity perpendicular to the ramp v(p0) due to the athlete's jumping force, the lift and drag forces acting during take-off and during the flight, and the weight of the athlete and his equipment. The aerodynamic forces are a function of the flight position and of the equipment features. They are a predominant performance factor and can largely be influenced by the athlete. The field study conducted during the Olympic Games competitions 2002 at Park City (elevation: 2000 m) showed an impressive ability of the Olympic medallists to reproduce their flight style and remarkable differences between different athletes have been found. The aerodynamic forces are proportional to the air density. Elite athletes are able to adapt their flight style to thin air conditions in order to maximise jump length and to keep the flight stable. The effects of flight position variations on the performance have been analysed by means of a computer model which is based on the equations of motion and on wind tunnel data corresponding to the flight positions found in the field. Athletes have to solve extremely difficult optimisation problems within fractions of a second. The computer simulation can be used as a reliable starting point for the improvement of training methods and gives an insight into the "implicit" knowledge of physics that the ski jumping athlete must have available for a good performance.

  13. Geodetic results from ISAGEX data. [for obtaining center of mass coordinates for geodetic camera sites

    NASA Technical Reports Server (NTRS)

    Marsh, J. G.; Douglas, B. C.; Walls, D. M.

    1974-01-01

    Laser and camera data taken during the International Satellite Geodesy Experiment (ISAGEX) were used in dynamical solutions to obtain center-of-mass coordinates for the Astro-Soviet camera sites at Helwan, Egypt, and Oulan Bator, Mongolia, as well as the East European camera sites at Potsdam, German Democratic Republic, and Ondrejov, Czechoslovakia. The results are accurate to about 20m in each coordinate. The orbit of PEOLE (i=15) was also determined from ISAGEX data. Mean Kepler elements suitable for geodynamic investigations are presented.

  14. Fixed point theorems for generalized α -β-weakly contraction mappings in metric spaces and applications.

    PubMed

    Latif, Abdul; Mongkolkeha, Chirasak; Sintunavarat, Wutiphol

    2014-01-01

    We extend the notion of generalized weakly contraction mappings due to Choudhury et al. (2011) to generalized α-β-weakly contraction mappings. We show with examples that our new class of mappings is a real generalization of several known classes of mappings. We also establish fixed point results for such mappings in metric spaces. Applying our new results, we obtain fixed point results on ordinary metric spaces, metric spaces endowed with an arbitrary binary relation, and metric spaces endowed with graph.

  15. Point-point and point-line moving-window correlation spectroscopy and its applications

    NASA Astrophysics Data System (ADS)

    Zhou, Qun; Sun, Suqin; Zhan, Daqi; Yu, Zhiwu

    2008-07-01

    In this paper, we present a new extension of generalized two-dimensional (2D) correlation spectroscopy. Two new algorithms, namely point-point (P-P) correlation and point-line (P-L) correlation, have been introduced to do the moving-window 2D correlation (MW2D) analysis. The new method has been applied to a spectral model consisting of two different processes. The results indicate that P-P correlation spectroscopy can unveil the details and re-constitute the entire process, whilst the P-L can provide general feature of the concerned processes. Phase transition behavior of dimyristoylphosphotidylethanolamine (DMPE) has been studied using MW2D correlation spectroscopy. The newly proposed method verifies that the phase transition temperature is 56 °C, same as the result got from a differential scanning calorimeter. To illustrate the new method further, a lysine and lactose mixture has been studied under thermo perturbation. Using the P-P MW2D, the Maillard reaction of the mixture was clearly monitored, which has been very difficult using conventional display of FTIR spectra.

  16. Image Processing, Coding, and Compression with Multiple-Point Impulse Response Functions.

    NASA Astrophysics Data System (ADS)

    Stossel, Bryan Joseph

    1995-01-01

    Aspects of image processing, coding, and compression with multiple-point impulse response functions are investigated. Topics considered include characterization of the corresponding random-walk transfer function, image recovery for images degraded by the multiple-point impulse response, and the application of the blur function to image coding and compression. It is found that although the zeros of the real and imaginary parts of the random-walk transfer function occur in continuous, closed contours, the zeros of the transfer function occur at isolated spatial frequencies. Theoretical calculations of the average number of zeros per area are in excellent agreement with experimental results obtained from computer counts of the zeros. The average number of zeros per area is proportional to the standard deviations of the real part of the transfer function as well as the first partial derivatives. Statistical parameters of the transfer function are calculated including the mean, variance, and correlation functions for the real and imaginary parts of the transfer function and their corresponding first partial derivatives. These calculations verify the assumptions required in the derivation of the expression for the average number of zeros. Interesting results are found for the correlations of the real and imaginary parts of the transfer function and their first partial derivatives. The isolated nature of the zeros in the transfer function and its characteristics at high spatial frequencies result in largely reduced reconstruction artifacts and excellent reconstructions are obtained for distributions of impulses consisting of 25 to 150 impulses. The multiple-point impulse response obscures original scenes beyond recognition. This property is important for secure transmission of data on many communication systems. The multiple-point impulse response enables the decoding and restoration of the original scene with very little distortion. Images prefiltered by the random

  17. A shape-based segmentation method for mobile laser scanning point clouds

    NASA Astrophysics Data System (ADS)

    Yang, Bisheng; Dong, Zhen

    2013-07-01

    Segmentation of mobile laser point clouds of urban scenes into objects is an important step for post-processing (e.g., interpretation) of point clouds. Point clouds of urban scenes contain numerous objects with significant size variability, complex and incomplete structures, and holes or variable point densities, raising great challenges for the segmentation of mobile laser point clouds. This paper addresses these challenges by proposing a shape-based segmentation method. The proposed method first calculates the optimal neighborhood size of each point to derive the geometric features associated with it, and then classifies the point clouds according to geometric features using support vector machines (SVMs). Second, a set of rules are defined to segment the classified point clouds, and a similarity criterion for segments is proposed to overcome over-segmentation. Finally, the segmentation output is merged based on topological connectivity into a meaningful geometrical abstraction. The proposed method has been tested on point clouds of two urban scenes obtained by different mobile laser scanners. The results show that the proposed method segments large-scale mobile laser point clouds with good accuracy and computationally effective time cost, and that it segments pole-like objects particularly well.

  18. Critical point and phase behavior of the pure fluid and a Lennard-Jones mixture

    NASA Astrophysics Data System (ADS)

    Potoff, Jeffrey J.; Panagiotopoulos, Athanassios Z.

    1998-12-01

    Monte Carlo simulations in the grand canonical ensemble were used to obtain liquid-vapor coexistence curves and critical points of the pure fluid and a binary mixture of Lennard-Jones particles. Critical parameters were obtained from mixed-field finite-size scaling analysis and subcritical coexistence data from histogram reweighting methods. The critical parameters of the untruncated Lennard-Jones potential were obtained as Tc*=1.3120±0.0007, ρc*=0.316±0.001 and pc*=0.1279±0.0006. Our results for the critical temperature and pressure are not in agreement with the recent study of Caillol [J. Chem. Phys. 109, 4885 (1998)] on a four-dimensional hypersphere. Mixture parameters were ɛ1=2ɛ2 and σ1=σ2, with Lorentz-Berthelot combining rules for the unlike-pair interactions. We determined the critical point at T*=1.0 and pressure-composition diagrams at three temperatures. Our results have much smaller statistical uncertainties relative to comparable Gibbs ensemble simulations.

  19. Physical constraints, fundamental limits, and optimal locus of operating points for an inverted pendulum based actuated dynamic walker.

    PubMed

    Patnaik, Lalit; Umanand, Loganathan

    2015-10-26

    The inverted pendulum is a popular model for describing bipedal dynamic walking. The operating point of the walker can be specified by the combination of initial mid-stance velocity (v0) and step angle (φm) chosen for a given walk. In this paper, using basic mechanics, a framework of physical constraints that limit the choice of operating points is proposed. The constraint lines thus obtained delimit the allowable region of operation of the walker in the v0-φm plane. A given average forward velocity vx,avg can be achieved by several combinations of v0 and φm. Only one of these combinations results in the minimum mechanical power consumption and can be considered the optimum operating point for the given vx,avg. This paper proposes a method for obtaining this optimal operating point based on tangency of the power and velocity contours. Putting together all such operating points for various vx,avg, a family of optimum operating points, called the optimal locus, is obtained. For the energy loss and internal energy models chosen, the optimal locus obtained has a largely constant step angle with increasing speed but tapers off at non-dimensional speeds close to unity.

  20. Higher-order triangular spectral element method with optimized cubature points for seismic wavefield modeling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Youshan, E-mail: ysliu@mail.iggcas.ac.cn; Teng, Jiwen, E-mail: jwteng@mail.iggcas.ac.cn; Xu, Tao, E-mail: xutao@mail.iggcas.ac.cn

    2017-05-01

    The mass-lumped method avoids the cost of inverting the mass matrix and simultaneously maintains spatial accuracy by adopting additional interior integration points, known as cubature points. To date, such points are only known analytically in tensor domains, such as quadrilateral or hexahedral elements. Thus, the diagonal-mass-matrix spectral element method (SEM) in non-tensor domains always relies on numerically computed interpolation points or quadrature points. However, only the cubature points for degrees 1 to 6 are known, which is the reason that we have developed a p-norm-based optimization algorithm to obtain higher-order cubature points. In this way, we obtain and tabulate newmore » cubature points with all positive integration weights for degrees 7 to 9. The dispersion analysis illustrates that the dispersion relation determined from the new optimized cubature points is comparable to that of the mass and stiffness matrices obtained by exact integration. Simultaneously, the Lebesgue constant for the new optimized cubature points indicates its surprisingly good interpolation properties. As a result, such points provide both good interpolation properties and integration accuracy. The Courant–Friedrichs–Lewy (CFL) numbers are tabulated for the conventional Fekete-based triangular spectral element (TSEM), the TSEM with exact integration, and the optimized cubature-based TSEM (OTSEM). A complementary study demonstrates the spectral convergence of the OTSEM. A numerical example conducted on a half-space model demonstrates that the OTSEM improves the accuracy by approximately one order of magnitude compared to the conventional Fekete-based TSEM. In particular, the accuracy of the 7th-order OTSEM is even higher than that of the 14th-order Fekete-based TSEM. Furthermore, the OTSEM produces a result that can compete in accuracy with the quadrilateral SEM (QSEM). The high accuracy of the OTSEM is also tested with a non-flat topography model. In terms of

  1. Traceable Co-C eutectic points for thermocouple calibration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jahan, F.; Ballico, M. J.

    2013-09-11

    National Measurement Institute of Australia (NMIA) has developed a miniature crucible design suitable for measurement by both thermocouples and radiation thermometry, and has established an ensemble of five Co-C eutectic-point cells based on this design. The cells in this ensemble have been individually calibrated using both ITS-90 radiation thermometry and thermocouples calibrated on the ITS-90 by the NMIA mini-coil methodology. The assigned ITS-90 temperatures obtained using these different techniques are both repeatable and consistent, despite the use of different furnaces and measurement conditions. The results demonstrate that, if individually calibrated, such cells can be practically used as part of amore » national traceability scheme for thermocouple calibration, providing a useful intermediate calibration point between Cu and Pd.« less

  2. Determining the refractive index of particles using glare-point imaging technique

    NASA Astrophysics Data System (ADS)

    Meng, Rui; Ge, Baozhen; Lu, Qieni; Yu, Xiaoxue

    2018-04-01

    A method of measuring the refractive index of a particle is presented from a glare-point image. The space of a doublet image of a particle can be determined with high accuracy by using auto-correlation and Gaussian interpolation, and then the refractive index is obtained from glare-point separation, and a factor that may influence the accuracy of glare-point separation is explored. Experiments are carried out for three different kinds of particles, including polystyrene latex particles, glass beads, and water droplets, whose measuring accuracy is improved by the data fitting method. The research results show that the method presented in this paper is feasible and beneficial to applications such as spray and atmospheric composition measurements.

  3. On spinodal points and Lee-Yang edge singularities

    NASA Astrophysics Data System (ADS)

    An, X.; Mesterházy, D.; Stephanov, M. A.

    2018-03-01

    We address a number of outstanding questions associated with the analytic properties of the universal equation of state of the φ4 theory, which describes the critical behavior of the Ising model and ubiquitous critical points of the liquid–gas type. We focus on the relation between spinodal points that limit the domain of metastability for temperatures below the critical temperature, i.e. T < Tc , and Lee-Yang edge singularities that restrict the domain of analyticity around the point of zero magnetic field H for T > Tc . The extended analyticity conjecture (due to Fonseca and Zamolodchikov) posits that, for T < Tc , the Lee-Yang edge singularities are the closest singularities to the real H axis. This has interesting implications, in particular, that the spinodal singularities must lie off the real H axis for d < 4 , in contrast to the commonly known result of the mean-field approximation. We find that the parametric representation of the Ising equation of state obtained in the \\renewcommandε{\\varepsilon} \

  4. Main results and experience obtained on Mir space station and experiment program for Russian segment of ISS.

    PubMed

    Utkin, V F; Lukjashchenko, V I; Borisov, V V; Suvorov, V V; Tsymbalyuk, M M

    2003-07-01

    This article presents main scientific and practical results obtained in course of scientific and applied research and experiments on Mir space station. Based on Mir experience, processes of research program formation for the Russian Segment of the ISS are briefly described. The major trends of activities planned in the frames of these programs as well as preliminary results of increment research programs implementation in the ISS' first missions are also presented. c2003 Elsevier Science Ltd. All rights reserved.

  5. Barriers to Point-of-Care Testing in India: Results from Qualitative Research across Different Settings, Users and Major Diseases

    PubMed Central

    Engel, Nora; Ganesh, Gayatri; Patil, Mamata; Yellappa, Vijayashree; Pant Pai, Nitika; Vadnais, Caroline; Pai, Madhukar

    2015-01-01

    Background Successful point-of-care testing, namely ensuring the completion of the test and treat cycle in the same encounter, has immense potential to reduce diagnostic and treatment delays, and impact patient outcomes. However, having rapid tests is not enough, as many barriers may prevent their successful implementation in point-of-care testing programs. Qualitative research on diagnostic practices may help identify such barriers across different points of care in health systems. Methods In this exploratory qualitative study, we conducted 78 semi-structured interviews and 13 focus group discussions in an urban and rural area of Karnataka, India, with healthcare providers (doctors, nurses, specialists, traditional healers, and informal providers), patients, community health workers, test manufacturers, laboratory technicians, program managers and policy-makers. Participants were purposively sampled to represent settings of hospitals, peripheral labs, clinics, communities and homes, in both the public and private sectors. Results In the Indian context, the onus is on the patient to ensure successful point-of-care testing across homes, clinics, labs and hospitals, amidst uncoordinated providers with divergent and often competing practices, in settings lacking material, money and human resources. We identified three overarching themes affecting point-of-care testing: the main theme is ‘relationships’ among providers and between providers and patients, influenced by the cross-cutting theme of ‘infrastructure’. Challenges with both result in ‘modified practices’ often favouring empirical (symptomatic) treatment over treatment guided by testing. Conclusions Even if tests can be conducted on the spot and infrastructure challenges have been resolved, relationships among providers and between patients and providers are crucial for successful point-of-care testing. Furthermore, these barriers do not act in isolation, but are interlinked and need to be examined

  6. 25 CFR 162.539 - Must I obtain a WEEL before obtaining a WSR lease?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... AND PERMITS Wind and Solar Resource Leases Wsr Leases § 162.539 Must I obtain a WEEL before obtaining... direct result of energy resource information gathered from a WEEL activity, obtaining a WEEL is not a...

  7. 25 CFR 162.539 - Must I obtain a WEEL before obtaining a WSR lease?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... AND PERMITS Wind and Solar Resource Leases Wsr Leases § 162.539 Must I obtain a WEEL before obtaining... direct result of energy resource information gathered from a WEEL activity, obtaining a WEEL is not a...

  8. Traumatic neuralgia from pressure-point strikes in the martial arts: results from a retrospective online survey.

    PubMed

    Kelly, Michael D

    2008-06-01

    Many techniques in Asian martial arts hand-to-hand combat systems emphasize hitting or striking specific sites on the body that correlate with exposed portions of peripheral nerves. To evaluate the prevalence and clinical effects of this unique sports-related injury. An anonymous self-administered retrospective 20-question electronic survey was posted on a high-traffic martial arts Web site. Primary outcome measures were demographic and medical history data, including martial arts experience and neuropathic symptoms associated with injury from this form of combat. Risk of symptoms was calculated by dividing the number of individuals with symptoms in each pressure-point area by the number of individuals who were struck in these areas during martial arts training. Of the 651 survey responses received, 605 met inclusion criteria. Neuropathic symptoms were reported by 291 subjects. Most symptoms occurred in individuals aged between 20 and 30 years as well as in individuals with less than 1 year of martial arts training. The majority of respondents with neuropathic symptoms reported a symptom duration of less than 1 year (207 [71%]). Individuals with more than 5 years of combat training experience had a greater risk of chronic symptoms than individuals with less experience. Strikes to pressure points on the back had the greatest risk of inducing neuropathic symptoms. Symptoms of neurapraxia can occur in individuals as a result of practicing martial arts involving strikes on pressure points. Although the majority of symptoms resolve within 1 year, individuals with prolonged exposure to pressure-point strikes may be more likely to have chronic symptoms.

  9. On an Integral with Two Branch Points

    ERIC Educational Resources Information Center

    de Oliveira, E. Capelas; Chiacchio, Ary O.

    2006-01-01

    The paper considers a class of real integrals performed by using a convenient integral in the complex plane. A complex integral containing a multi-valued function with two branch points is transformed into another integral containing a pole and a unique branch point. As a by-product we obtain a new class of integrals which can be calculated in a…

  10. Y-MP floating point and Cholesky factorization

    NASA Technical Reports Server (NTRS)

    Carter, Russell

    1991-01-01

    The floating point arithmetics implemented in the Cray 2 and Cray Y-MP computer systems are nearly identical, but large scale computations performed on the two systems have exhibited significant differences in accuracy. The difference in accuracy is analyzed for Cholesky factorization algorithm, and it is found that the source of the difference is the subtract magnitude operation of the Cray Y-MP. The results from numerical experiments for a range of problem sizes are presented, and an efficient method for improving the accuracy of the factorization obtained on the Y-MP is presented.

  11. Thermodynamic temperature assignment to the point of inflection of the melting curve of high-temperature fixed points.

    PubMed

    Woolliams, E R; Anhalt, K; Ballico, M; Bloembergen, P; Bourson, F; Briaudeau, S; Campos, J; Cox, M G; del Campo, D; Dong, W; Dury, M R; Gavrilov, V; Grigoryeva, I; Hernanz, M L; Jahan, F; Khlevnoy, B; Khromchenko, V; Lowe, D H; Lu, X; Machin, G; Mantilla, J M; Martin, M J; McEvoy, H C; Rougié, B; Sadli, M; Salim, S G R; Sasajima, N; Taubert, D R; Todd, A D W; Van den Bossche, R; van der Ham, E; Wang, T; Whittam, A; Wilthan, B; Woods, D J; Woodward, J T; Yamada, Y; Yamaguchi, Y; Yoon, H W; Yuan, Z

    2016-03-28

    The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.43 ± 0.18 K and 1597.39 ± 0.13 K, respectively, and the thermodynamic temperature of the freezing transition of Cu has been determined to be 1357.80 ± 0.08 K, where the ± symbol represents 95% coverage. These results are the best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. The good agreement between the institutes suggests that spectroradiometric thermometry techniques are sufficiently mature (at least in those institutes) to allow the direct realization of thermodynamic temperature above 1234 K (rather than the use of a temperature scale) and that metal-carbon eutectics can be used as high-temperature fixed points for thermodynamic temperature dissemination. The results directly support the developing mise en pratique for the definition of the kelvin to include direct measurement of thermodynamic temperature. © 2016 The Author(s).

  12. A note on a boundary sine-Gordon model at the free-Fermion point

    NASA Astrophysics Data System (ADS)

    Murgan, Rajan

    2018-02-01

    We investigate the free-Fermion point of a boundary sine-Gordon model with nondiagonal boundary interactions for the ground state using auxiliary functions obtained from T  -  Q equations of a corresponding inhomogeneous open spin-\\frac{1}{2} XXZ chain with nondiagonal boundary terms. In particular, we obtain the Casimir energy. Our result for the Casimir energy is shown to agree with the result from the TBA approach. The analytical result for the effective central charge in the ultraviolet (UV) limit is also verified from the plots of effective central charge for intermediate values of volume.

  13. A comparison of methods for determining HIV viral set point.

    PubMed

    Mei, Y; Wang, L; Holte, S E

    2008-01-15

    During a course of human immunodeficiency virus (HIV-1) infection, the viral load usually increases sharply to a peak following infection and then drops rapidly to a steady state, where it remains until progression to AIDS. This steady state is often referred to as the viral set point. It is believed that the HIV viral set point results from an equilibrium between the HIV virus and immune response and is an important indicator of AIDS disease progression. In this paper, we analyze a real data set of viral loads measured before antiretroviral therapy is initiated, and propose two-phase regression models to utilize all available data to estimate the viral set point. The advantages of the proposed methods are illustrated by comparing them with two empirical methods, and the reason behind the improvement is also studied. Our results illustrate that for our data set, the viral load data are highly correlated and it is cost effective to estimate the viral set point based on one or two measurements obtained between 5 and 12 months after HIV infection. The utility and limitations of this recommendation will be discussed. Copyright (c) 2007 John Wiley & Sons, Ltd.

  14. Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

    PubMed Central

    Pereira, N F; Sitek, A

    2011-01-01

    Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated. PMID:20736496

  15. Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

    NASA Astrophysics Data System (ADS)

    Pereira, N. F.; Sitek, A.

    2010-09-01

    Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated.

  16. From global to heavy-light: 5-point conformal blocks

    NASA Astrophysics Data System (ADS)

    Alkalaev, Konstantin; Belavin, Vladimir

    2016-03-01

    We consider Virasoro conformal blocks in the large central charge limit. There are different regimes depending on the behavior of the conformal dimensions. The most simple regime is reduced to the global sl(2,C) conformal blocks while the most complicated one is known as the classical conformal blocks. Recently, Fitzpatrick, Kaplan, and Walters showed that the two regimes are related through the intermediate stage of the so-called heavy-light semiclassical limit. We study this idea in the particular case of the 5-point conformal block. To find the 5-point global block we use the projector technique and the Casimir operator approach. Furthermore, we discuss the relation between the global and the heavy-light limits and construct the heavy-light block from the global block. In this way we reproduce our previous results for the 5-point perturbative classical block obtained by means of the monodromy method.

  17. Obtaining Approximate Values of Exterior Orientation Elements of Multi-Intersection Images Using Particle Swarm Optimization

    NASA Astrophysics Data System (ADS)

    Li, X.; Li, S. W.

    2012-07-01

    carried out. In the first experiment, images of a standard grid board are taken according to multi-intersection photography using digital camera. Three points or six points which are located on the left-down corner of the standard grid are regarded as control points respectively, and the exterior orientation elements of each image are computed through PSO, and compared with these elements computed through bundle adjustment. In the second experiment, the exterior orientation elements obtained from the first experiment are used as approximate values in bundle adjustment and then the space coordinates of other grid points on the board can be computed. The coordinate difference of grid points between these computed space coordinates and their known coordinates can be used to compute the accuracy. The point accuracy computed in above experiments are ±0.76mm and ±0.43mm respectively. The above experiments prove the effectiveness of PSO used in close range photogrammetry to compute approximate values of exterior orientation elements, and the algorithm can meet the requirement of higher accuracy. In short, PSO can get better results in a faster, cheaper way compared with other surveying methods in close range photogrammetry.

  18. Application of inertial instruments for DSN antenna pointing and tracking

    NASA Technical Reports Server (NTRS)

    Eldred, D. B.; Nerheim, N. M.; Holmes, K. G.

    1990-01-01

    The feasibility of using inertial instruments to determine the pointing attitude of the NASA Deep Space Network antennas is examined. The objective is to obtain 1 mdeg pointing knowledge in both blind pointing and tracking modes to facilitate operation of the Deep Space Network 70 m antennas at 32 GHz. A measurement system employing accelerometers, an inclinometer, and optical gyroscopes is proposed. The initial pointing attitude is established by determining the direction of the local gravity vector using the accelerometers and the inclinometer, and the Earth's spin axis using the gyroscopes. Pointing during long-term tracking is maintained by integrating the gyroscope rates and augmenting these measurements with knowledge of the local gravity vector. A minimum-variance estimator is used to combine measurements to obtain the antenna pointing attitude. A key feature of the algorithm is its ability to recalibrate accelerometer parameters during operation. A survey of available inertial instrument technologies is also given.

  19. Asymptotic One-Point Functions in Gauge-String Duality with Defects.

    PubMed

    Buhl-Mortensen, Isak; de Leeuw, Marius; Ipsen, Asger C; Kristjansen, Charlotte; Wilhelm, Matthias

    2017-12-29

    We take the first step in extending the integrability approach to one-point functions in AdS/dCFT to higher loop orders. More precisely, we argue that the formula encoding all tree-level one-point functions of SU(2) operators in the defect version of N=4 supersymmetric Yang-Mills theory, dual to the D5-D3 probe-brane system with flux, has a natural asymptotic generalization to higher loop orders. The asymptotic formula correctly encodes the information about the one-loop correction to the one-point functions of nonprotected operators once dressed by a simple flux-dependent factor, as we demonstrate by an explicit computation involving a novel object denoted as an amputated matrix product state. Furthermore, when applied to the Berenstein-Maldacena-Nastase vacuum state, the asymptotic formula gives a result for the one-point function which in a certain double-scaling limit agrees with that obtained in the dual string theory up to wrapping order.

  20. Possibilities for Using LIDAR and Photogrammetric Data Obtained with AN Unmanned Aerial Vehicle for Levee Monitoring

    NASA Astrophysics Data System (ADS)

    Bakuła, K.; Ostrowski, W.; Szender, M.; Plutecki, W.; Salach, A.; Górski, K.

    2016-06-01

    This paper presents the possibilities for using an unmanned aerial system for evaluation of the condition of levees. The unmanned aerial system is equipped with two types of sensor. One is an ultra-light laser scanner, integrated with a GNSS receiver and an INS system; the other sensor is a digital camera that acquires data with stereoscopic coverage. Sensors have been mounted on the multirotor, unmanned platform the Hawk Moth, constructed by MSP company. LiDAR data and images of levees the length of several hundred metres were acquired during testing of the platform. Flights were performed in several variants. Control points measured with the use of the GNSS technique were considered as reference data. The obtained results are presented in this paper; the methodology of processing the acquired LiDAR data, which increase in accuracy when low accuracy of the navigation systems occurs as a result of systematic errors, is also discussed. The Iterative Closest Point (ICP) algorithm, as well as measurements of control points, were used to georeference the LiDAR data. Final accuracy in the order of centimetres was obtained for generation of the digital terrain model. The final products of the proposed UAV data processing are digital elevation models, an orthophotomap and colour point clouds. The authors conclude that such a platform offers wide possibilities for low-budget flights to deliver the data, which may compete with typical direct surveying measurements performed during monitoring of such objects. However, the biggest advantage is the density and continuity of data, which allows for detection of changes in objects being monitored.

  1. Two-point derivative dispersion relations

    NASA Astrophysics Data System (ADS)

    Ferreira, Erasmo; Sesma, Javier

    2013-03-01

    A new derivation is given for the representation, under certain conditions, of the integral dispersion relations of scattering theory through local forms. The resulting expressions have been obtained through an independent procedure to construct the real part and consist of new mathematical structures of double infinite summations of derivatives. In this new form the derivatives are calculated at the generic value of the energy E and separately at the reference point E = m that is the lower limit of the integration. This new form may be more interesting in certain circumstances and directly shows the origin of the difficulties in convergence that were present in the old truncated forms called standard-derivative dispersion relations (DDR). For all cases in which the reductions of the double to single sums were obtained in our previous work, leading to explicit demonstration of convergence, these new expressions are seen to be identical to the previous ones. We present, as a glossary, the most simplified explicit results for the DDR's in the cases of imaginary amplitudes of forms (E/m)λ[ln (E/m)]n that cover the cases of practical interest in particle physics phenomenology at high energies. We explicitly study the expressions for the cases with λ negative odd integers, that require identification of cancelation of singularities, and provide the corresponding final results.

  2. Transfer to the Collinear Libration Point L3 in the Sun-Earth+Moon System

    NASA Technical Reports Server (NTRS)

    Hou, Xi-yun; Tang, Jing-shi; Liu, Lin

    2007-01-01

    The collinear libration point L3 of the sun-earth+moon system is an ideal place for some space missions. Although there has been a great amount of work concerning the applications of the other two collinear libration points L1 and L2, little work has been done about the point L3. In this paper, the dynamics of the libration points was briefly introduced first. Then a way to transfer the spacecraft to the collinear libration point L3 via the invariant manifolds of the other two collinear libration points was proposed. Theoretical works under the model of circular restricted three-body problem were done. For the sun-earth+moon system, this model is a good approximation. The results obtained are useful when a transfer trajectory under the real solar system is designed.

  3. From tunneling to point contact: Correlation between forces and current

    NASA Astrophysics Data System (ADS)

    Sun, Yan; Mortensen, Henrik; Schär, Sacha; Lucier, Anne-Sophie; Miyahara, Yoichi; Grütter, Peter; Hofer, Werner

    2005-05-01

    We used a combined ultrahigh vacuum scanning tunneling and atomic force microscope (STM/AFM) to study W tip-Au(111) sample interactions in the regimes from weak coupling to strong interaction and simultaneously measure current changes from picoamperes to microamperes. Close correlation between conductance and interaction forces in a STM configuration was observed. In particular, the electrical and mechanical points of contact are determined based on the observed barrier collapse and adhesive bond formation, respectively. These points of contact, as defined by force and current measurements, coincide within measurement error. Ab initio calculations of the current as a function of distance in the tunneling regime is in quantitative agreement with experimental results. The obtained results are discussed in the context of dissipation in noncontact AFM as well as electrical contact formation in molecular electronics.

  4. Effect of windowing on lithosphere elastic thickness estimates obtained via the coherence method: Results from northern South America

    NASA Astrophysics Data System (ADS)

    Ojeda, GermáN. Y.; Whitman, Dean

    2002-11-01

    The effective elastic thickness (Te) of the lithosphere is a parameter that describes the flexural strength of a plate. A method routinely used to quantify this parameter is to calculate the coherence between the two-dimensional gravity and topography spectra. Prior to spectra calculation, data grids must be "windowed" in order to avoid edge effects. We investigated the sensitivity of Te estimates obtained via the coherence method to mirroring, Hanning and multitaper windowing techniques on synthetic data as well as on data from northern South America. These analyses suggest that the choice of windowing technique plays an important role in Te estimates and may result in discrepancies of several kilometers depending on the selected windowing method. Te results from mirrored grids tend to be greater than those from Hanning smoothed or multitapered grids. Results obtained from mirrored grids are likely to be over-estimates. This effect may be due to artificial long wavelengths introduced into the data at the time of mirroring. Coherence estimates obtained from three subareas in northern South America indicate that the average effective elastic thickness is in the range of 29-30 km, according to Hanning and multitaper windowed data. Lateral variations across the study area could not be unequivocally determined from this study. We suggest that the resolution of the coherence method does not permit evaluation of small (i.e., ˜5 km), local Te variations. However, the efficiency and robustness of the coherence method in rendering continent-scale estimates of elastic thickness has been confirmed.

  5. CROSS-SECTIONAL STUDY ON DIFFERENT ENTRY POINTS FOR ANTEROGRADE FEMORAL INTRAMEDULLARY OSTEOSYNTHESIS

    PubMed Central

    Kanas, Michel; Wajnsztejn, Andre; Roucourt, Danilo; Fiorentino, Eduardo; Fernandes, Hélio Jorge Alvachian; dos Reis, Fernando Baldy

    2015-01-01

    Objective: To analyze the degree of knowledge among professionals who treat fractures using the recommended technique, with regard to correlating the nail with the entry point that is considered appropriate. Methods: A questionnaire that presented five types of nail and simulated a transverse diaphyseal fracture of the femur was developed. Results: Responses regarding the entry points corresponding to choosing the type of nail were obtained from 370 orthopedists who were participating in the 41st Brazilian Congress of Orthopedics and Traumatology. It was observed that only 20% correctly identified the entry point and that there was no difference between the professionals within the specialty of Traumatology and the others. Conclusion: It was concluded that the majority of the physicians attending the congress were unaware of the entry points. PMID:27027047

  6. Equations for obtaining melting points for the ternary system ethylene glycol/sodium chloride/water and their application to cryopreservation.

    PubMed

    Woods, E J; Zieger, M A; Gao, D Y; Critser, J K

    1999-06-01

    The present study describes the H(2)O-NaCl-ethylene glycol ternary system by using a differential scanning calorimeter to measure melting points (T(m)) of four different ratios (R) of ethylene glycol to NaCl and then devising equations to fit the experimental measurements. Ultimately an equation is derived which characterizes the liquidus surface above the eutectic for any R value in the system. This study focuses on ethylene glycol in part because of recent evidence indicating it may be less toxic to pancreatic islets than Me(2)SO, which is currently used routinely for islet cryopreservation. The resulting physical data and previously determined information regarding the osmotic characteristics of canine pancreatic islets are combined in a mathematical model to describe the volumetric response to equilibrium-rate freezing in varying initial concentrations of ethylene glycol. Copyright 1999 Academic Press.

  7. Optimization of Sample Points for Monitoring Arable Land Quality by Simulated Annealing while Considering Spatial Variations

    PubMed Central

    Wang, Junxiao; Wang, Xiaorui; Zhou, Shenglu; Wu, Shaohua; Zhu, Yan; Lu, Chunfeng

    2016-01-01

    With China’s rapid economic development, the reduction in arable land has emerged as one of the most prominent problems in the nation. The long-term dynamic monitoring of arable land quality is important for protecting arable land resources. An efficient practice is to select optimal sample points while obtaining accurate predictions. To this end, the selection of effective points from a dense set of soil sample points is an urgent problem. In this study, data were collected from Donghai County, Jiangsu Province, China. The number and layout of soil sample points are optimized by considering the spatial variations in soil properties and by using an improved simulated annealing (SA) algorithm. The conclusions are as follows: (1) Optimization results in the retention of more sample points in the moderate- and high-variation partitions of the study area; (2) The number of optimal sample points obtained with the improved SA algorithm is markedly reduced, while the accuracy of the predicted soil properties is improved by approximately 5% compared with the raw data; (3) With regard to the monitoring of arable land quality, a dense distribution of sample points is needed to monitor the granularity. PMID:27706051

  8. Performance Evaluation of Real-Time Precise Point Positioning Method

    NASA Astrophysics Data System (ADS)

    Alcay, Salih; Turgut, Muzeyyen

    2017-12-01

    Post-Processed Precise Point Positioning (PPP) is a well-known zero-difference positioning method which provides accurate and precise results. After the experimental tests, IGS Real Time Service (RTS) officially provided real time orbit and clock products for the GNSS community that allows real-time (RT) PPP applications. Different software packages can be used for RT-PPP. In this study, in order to evaluate the performance of RT-PPP, 3 IGS stations are used. Results, obtained by using BKG Ntrip Client (BNC) Software v2.12, are examined in terms of both accuracy and precision.

  9. Public safety answering point readiness for wireless E-911 in New York State.

    PubMed

    Bailey, Bob W; Scott, Jay M; Brown, Lawrence H

    2003-01-01

    To determine the level of wireless enhanced 911 readiness among New York's primary public safety answering points. This descriptive study utilized a simple, single-page survey that was distributed in August 2001, with telephone follow-up concluding in January 2002. Surveys were distributed to directors of the primary public safety answering points in each of New York's 62 counties. Information was requested regarding current readiness for providing wireless enhanced 911 service, hardware and software needs for implementing the service, and the estimated costs for obtaining the necessary hardware and software. Two directors did not respond and could not be contacted by telephone; three declined participation; one did not operate an answering point; and seven provided incomplete responses, resulting in usable data from 49 (79%) of the state's public safety answering points. Only 27% of the responding public safety answering points were currently wireless enhanced 911 ready. Specific needs included obtaining or upgrading computer systems (16%), computer-aided dispatch systems (53%), mapping software (71%), telephone systems (27%), and local exchange carrier trunk lines (42%). The total estimated hardware and software costs for achieving wireless enhanced 911 readiness was between 16 million and 20 million dollars. New York's primary public safety answering points are not currently ready to provide wireless enhanced 911 service, and the cost for achieving readiness could be as high as 20 million dollars.

  10. DAC-3 Pointing Stability Analysis Results for SAGE 3 and Other Users of the International Space Station (ISS) Payload Attachment Sites (PAS)

    NASA Technical Reports Server (NTRS)

    Woods-Vedeler, Jessica A.; Rombado, Gabriel

    1997-01-01

    The purpose of this paper is to provide final results of a pointing stability analysis for external payload attachment sites (PAS) on the International Space Station (ISS). As a specific example, the pointing stability requirement of the SAGE III atmospheric science instrument was examined in this paper. The instrument requires 10 arcsec stability over 2 second periods. SAGE 3 will be mounted on the ISS starboard side at the lower, outboard FIAS. In this engineering analysis, an open-loop DAC-3 finite element model of ISS was used by the Microgravity Group at Johnson Space Flight Center to generate transient responses at PAS to a limited number of disturbances. The model included dynamics up to 50 Hz. Disturbance models considered included operation of the solar array rotary joints, thermal radiator rotary joints, and control moment gyros. Responses were filtered to model the anticipated vibration attenuation effects of active control systems on the solar and thermal radiator rotary joints. A pointing stability analysis was conducted by double integrating acceleration transient over a 2 second period. Results of the analysis are tabulated for ISS X, Y, and Z Axis rotations. These results indicate that the largest excursions in rotation during pointing occurred due to rapid slewing of the thermal radiator. Even without attenuation at the rotary joints, the resulting pointing error was limited to less than 1.6 arcsec. With vibration control at the joints, to a maximum 0.5 arcsec over a 2 second period. Based on this current level of model definition, it was concluded that between 0 - 50 Hz, the pointing stability requirement for SAGE 3 will not be exceeded by the disturbances evaluated in this study.

  11. A comparative study of novel spectrophotometric methods based on isosbestic points; application on a pharmaceutical ternary mixture

    NASA Astrophysics Data System (ADS)

    Lotfy, Hayam M.; Saleh, Sarah S.; Hassan, Nagiba Y.; Salem, Hesham

    This work represents the application of the isosbestic points present in different absorption spectra. Three novel spectrophotometric methods were developed, the first method is the absorption subtraction method (AS) utilizing the isosbestic point in zero-order absorption spectra; the second method is the amplitude modulation method (AM) utilizing the isosbestic point in ratio spectra; and third method is the amplitude summation method (A-Sum) utilizing the isosbestic point in derivative spectra. The three methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The components at the isosbestic point were determined using the corresponding unified regression equation at this point with no need for a complementary method. The obtained results were statistically compared to each other and to that of the developed PLS model. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

  12. The effect of a turbulent wake on the stagnation point. II - Heat transfer results

    NASA Technical Reports Server (NTRS)

    Hanford, Anthony J.; Wilson, Dennis E.

    1992-01-01

    A phenomenological model is proposed which relates the effects of freestream turbulence to the increase in stagnation point heat transfer. The model requires both turbulence intensity and energy spectra as inputs to the unsteady velocity at the edge of the boundary layer. The form of the edge velocity contains both a pulsation of the incoming flow and an oscillation of the streamlines. The incompressible unsteady and time-averaged boundary layer response is determined by solving the momentum and energy equations. The model allows for arbitary two-dimensional geometry, however, results are given only for a circular cylinder. The time-averaged Nusselt number is determined theoretically and compared to existing experimental data.

  13. Pure F-actin networks are distorted and branched by steps in the critical-point drying method.

    PubMed

    Resch, Guenter P; Goldie, Kenneth N; Hoenger, Andreas; Small, J Victor

    2002-03-01

    Elucidation of the ultrastructural organization of actin networks is crucial for understanding the molecular mechanisms underlying actin-based motility. Results obtained from cytoskeletons and actin comets prepared by the critical-point procedure, followed by rotary shadowing, support recent models incorporating actin filament branching as a main feature of lamellipodia and pathogen propulsion. Since actin branches were not evident in earlier images obtained by negative staining, we explored how these differences arise. Accordingly, we have followed the structural fate of dense networks of pure actin filaments subjected to steps of the critical-point drying protocol. The filament networks have been visualized in parallel by both cryo-electron microscopy and negative staining. Our results demonstrate the selective creation of branches and other artificial structures in pure F-actin networks by the critical-point procedure and challenge the reliability of this method for preserving the detailed organization of actin assemblies that drive motility. (c) 2002 Elsevier Science (USA).

  14. Point charge representation of multicenter multipole moments in calculation of electrostatic properties

    NASA Technical Reports Server (NTRS)

    Sokalski, W. A.; Shibata, M.; Ornstein, R. L.; Rein, R.

    1993-01-01

    Distributed Point Charge Models (PCM) for CO, (H2O)2, and HS-SH molecules have been computed from analytical expressions using multi-center multipole moments. The point charges (set of charges including both atomic and non-atomic positions) exactly reproduce both molecular and segmental multipole moments, thus constituting an accurate representation of the local anisotropy of electrostatic properties. In contrast to other known point charge models, PCM can be used to calculate not only intermolecular, but also intramolecular interactions. Comparison of these results with more accurate calculations demonstrated that PCM can correctly represent both weak and strong (intramolecular) interactions, thus indicating the merit of extending PCM to obtain improved potentials for molecular mechanics and molecular dynamics computational methods.

  15. SHORT COMMUNICATION: Correlation between the Resistance Ratios of Platinum Resistance Thermometers at the Melting Point of Gallium and the Triple Point of Mercury

    NASA Astrophysics Data System (ADS)

    Singh, Y. P.; Maas, H.; Edler, F.; Zaidi, Z. H.

    1994-01-01

    A set of resistance ratios (W) for platinum resistance thermometers was obtained at the triple point of Hg and the melting point of Ga in order to study their relationship. It was found that using measured values for one of the fixed points, a linear equation will predict the value of the other. These measurements also indicate that the fixed points of Hg and of Ga are inconsistent by about 1,5 mK in the sense that either the melting point of Ga or the triple point of Hg was assigned too high a value on the ITS-90.

  16. PPF Dependent Fixed Point Results for Triangular α c-Admissible Mappings

    PubMed Central

    Ćirić, Ljubomir; Alsulami, Saud M.; Salimi, Peyman

    2014-01-01

    We introduce the concept of triangular α c-admissible mappings (pair of mappings) with respect to η c nonself-mappings and establish the existence of PPF dependent fixed (coincidence) point theorems for contraction mappings involving triangular α c-admissible mappings (pair of mappings) with respect to η c nonself-mappings in Razumikhin class. Several interesting consequences of our theorems are also given. PMID:24672352

  17. SPS antenna pointing control

    NASA Technical Reports Server (NTRS)

    Hung, J. C.

    1980-01-01

    The pointing control of a microwave antenna of the Satellite Power System was investigated emphasizing: (1) the SPS antenna pointing error sensing method; (2) a rigid body pointing control design; and (3) approaches for modeling the flexible body characteristics of the solar collector. Accuracy requirements for the antenna pointing control consist of a mechanical pointing control accuracy of three arc-minutes and an electronic phased array pointing accuracy of three arc-seconds. Results based on the factors considered in current analysis, show that the three arc-minute overall pointing control accuracy can be achieved in practice.

  18. Statistical aspects of point count sampling

    USGS Publications Warehouse

    Barker, R.J.; Sauer, J.R.; Ralph, C.J.; Sauer, J.R.; Droege, S.

    1995-01-01

    The dominant feature of point counts is that they do not census birds, but instead provide incomplete counts of individuals present within a survey plot. Considering a simple model for point count sampling, we demon-strate that use of these incomplete counts can bias estimators and testing procedures, leading to inappropriate conclusions. A large portion of the variability in point counts is caused by the incomplete counting, and this within-count variation can be confounded with ecologically meaningful varia-tion. We recommend caution in the analysis of estimates obtained from point counts. Using; our model, we also consider optimal allocation of sampling effort. The critical step in the optimization process is in determining the goals of the study and methods that will be used to meet these goals. By explicitly defining the constraints on sampling and by estimating the relationship between precision and bias of estimators and time spent counting, we can predict the optimal time at a point for each of several monitoring goals. In general, time spent at a point will differ depending on the goals of the study.

  19. Automatic pole-like object modeling via 3D part-based analysis of point cloud

    NASA Astrophysics Data System (ADS)

    He, Liu; Yang, Haoxiang; Huang, Yuchun

    2016-10-01

    Pole-like objects, including trees, lampposts and traffic signs, are indispensable part of urban infrastructure. With the advance of vehicle-based laser scanning (VLS), massive point cloud of roadside urban areas becomes applied in 3D digital city modeling. Based on the property that different pole-like objects have various canopy parts and similar trunk parts, this paper proposed the 3D part-based shape analysis to robustly extract, identify and model the pole-like objects. The proposed method includes: 3D clustering and recognition of trunks, voxel growing and part-based 3D modeling. After preprocessing, the trunk center is identified as the point that has local density peak and the largest minimum inter-cluster distance. Starting from the trunk centers, the remaining points are iteratively clustered to the same centers of their nearest point with higher density. To eliminate the noisy points, cluster border is refined by trimming boundary outliers. Then, candidate trunks are extracted based on the clustering results in three orthogonal planes by shape analysis. Voxel growing obtains the completed pole-like objects regardless of overlaying. Finally, entire trunk, branch and crown part are analyzed to obtain seven feature parameters. These parameters are utilized to model three parts respectively and get signal part-assembled 3D model. The proposed method is tested using the VLS-based point cloud of Wuhan University, China. The point cloud includes many kinds of trees, lampposts and other pole-like posters under different occlusions and overlaying. Experimental results show that the proposed method can extract the exact attributes and model the roadside pole-like objects efficiently.

  20. Beaconless Pointing for Deep-Space Optical Communication

    NASA Technical Reports Server (NTRS)

    Swank, Aaron J.; Aretskin-Hariton, Eliot; Le, Dzu K.; Sands, Obed S.; Wroblewski, Adam

    2016-01-01

    Free space optical communication is of interest to NASA as a complement to existing radio frequency communication methods. The potential for an increase in science data return capability over current radio-frequency communications is the primary objective. Deep space optical communication requires laser beam pointing accuracy on the order of a few microradians. The laser beam pointing approach discussed here operates without the aid of a terrestrial uplink beacon. Precision pointing is obtained from an on-board star tracker in combination with inertial rate sensors and an outgoing beam reference vector. The beaconless optical pointing system presented in this work is the current approach for the Integrated Radio and Optical Communication (iROC) project.

  1. Parametric study of two-body floating-point wave absorber

    NASA Astrophysics Data System (ADS)

    Amiri, Atena; Panahi, Roozbeh; Radfar, Soheil

    2016-03-01

    In this paper, we present a comprehensive numerical simulation of a point wave absorber in deep water. Analyses are performed in both the frequency and time domains. The converter is a two-body floating-point absorber (FPA) with one degree of freedom in the heave direction. Its two parts are connected by a linear mass-spring-damper system. The commercial ANSYS-AQWA software used in this study performs well in considering validations. The velocity potential is obtained by assuming incompressible and irrotational flow. As such, we investigated the effects of wave characteristics on energy conversion and device efficiency, including wave height and wave period, as well as the device diameter, draft, geometry, and damping coefficient. To validate the model, we compared our numerical results with those from similar experiments. Our study results can clearly help to maximize the converter's efficiency when considering specific conditions.

  2. Memory persistency and nonlinearity in daily mean dew point across India

    NASA Astrophysics Data System (ADS)

    Ray, Rajdeep; Khondekar, Mofazzal Hossain; Ghosh, Koushik; Bhattacharjee, Anup Kumar

    2016-04-01

    Enterprising endeavour has been taken in this work to realize and estimate the persistence in memory of the daily mean dew point time series obtained from seven different weather stations viz. Kolkata, Chennai (Madras), New Delhi, Mumbai (Bombay), Bhopal, Agartala and Ahmedabad representing different geographical zones in India. Hurst exponent values reveal an anti-persistent behaviour of these dew point series. To affirm the Hurst exponent values, five different scaling methods have been used and the corresponding results are compared to synthesize a finer and reliable conclusion out of it. The present analysis also bespeaks that the variation in daily mean dew point is governed by a non-stationary process with stationary increments. The delay vector variance (DVV) method has been exploited to investigate nonlinearity, and the present calculation confirms the presence of deterministic nonlinear profile in the daily mean dew point time series of the seven stations.

  3. The Modulus of Rupture from a Mathematical Point of View

    NASA Astrophysics Data System (ADS)

    Quintela, P.; Sánchez, M. T.

    2007-04-01

    The goal of this work is to present a complete mathematical study about the three-point bending experiments and the modulus of rupture of brittle materials. We will present the mathematical model associated to three-point bending experiments and we will use the asymptotic expansion method to obtain a new formula to calculate the modulus of rupture. We will compare the modulus of rupture of porcelain obtained with the previous formula with that obtained by using the classic theoretical formula. Finally, we will also present one and three-dimensional numerical simulations to compute the modulus of rupture.

  4. Three-dimensional reconstruction of indoor whole elements based on mobile LiDAR point cloud data

    NASA Astrophysics Data System (ADS)

    Gong, Yuejian; Mao, Wenbo; Bi, Jiantao; Ji, Wei; He, Zhanjun

    2014-11-01

    Ground-based LiDAR is one of the most effective city modeling tools at present, which has been widely used for three-dimensional reconstruction of outdoor objects. However, as for indoor objects, there are some technical bottlenecks due to lack of GPS signal. In this paper, based on the high-precision indoor point cloud data which was obtained by LiDAR, an international advanced indoor mobile measuring equipment, high -precision model was fulfilled for all indoor ancillary facilities. The point cloud data we employed also contain color feature, which is extracted by fusion with CCD images. Thus, it has both space geometric feature and spectral information which can be used for constructing objects' surface and restoring color and texture of the geometric model. Based on Autodesk CAD platform and with help of PointSence plug, three-dimensional reconstruction of indoor whole elements was realized. Specifically, Pointools Edit Pro was adopted to edit the point cloud, then different types of indoor point cloud data was processed, including data format conversion, outline extracting and texture mapping of the point cloud model. Finally, three-dimensional visualization of the real-world indoor was completed. Experiment results showed that high-precision 3D point cloud data obtained by indoor mobile measuring equipment can be used for indoor whole elements' 3-d reconstruction and that methods proposed in this paper can efficiently realize the 3 -d construction of indoor whole elements. Moreover, the modeling precision could be controlled within 5 cm, which was proved to be a satisfactory result.

  5. Incompressible material point method for free surface flow

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Zhang, Xiong; Sze, Kam Yim; Lian, Yanping; Liu, Yan

    2017-02-01

    To overcome the shortcomings of the weakly compressible material point method (WCMPM) for modeling the free surface flow problems, an incompressible material point method (iMPM) is proposed based on operator splitting technique which splits the solution of momentum equation into two steps. An intermediate velocity field is first obtained by solving the momentum equations ignoring the pressure gradient term, and then the intermediate velocity field is corrected by the pressure term to obtain a divergence-free velocity field. A level set function which represents the signed distance to free surface is used to track the free surface and apply the pressure boundary conditions. Moreover, an hourglass damping is introduced to suppress the spurious velocity modes which are caused by the discretization of the cell center velocity divergence from the grid vertexes velocities when solving pressure Poisson equations. Numerical examples including dam break, oscillation of a cubic liquid drop and a droplet impact into deep pool show that the proposed incompressible material point method is much more accurate and efficient than the weakly compressible material point method in solving free surface flow problems.

  6. Precise determination of time to reach viral load set point after acute HIV-1 infection.

    PubMed

    Huang, Xiaojie; Chen, Hui; Li, Wei; Li, Haiying; Jin, Xia; Perelson, Alan S; Fox, Zoe; Zhang, Tong; Xu, Xiaoning; Wu, Hao

    2012-12-01

    The HIV viral load set point has long been used as a prognostic marker of disease progression and more recently as an end-point parameter in HIV vaccine clinical trials. The definition of set point, however, is variable. Moreover, the earliest time at which the set point is reached after the onset of infection has never been clearly defined. In this study, we obtained sequential plasma viral load data from 60 acutely HIV-infected Chinese patients among a cohort of men who have sex with men, mathematically determined viral load set point levels, and estimated time to attain set point after infection. We also compared the results derived from our models and that obtained from an empirical method. With novel uncomplicated mathematic model, we discovered that set points may vary from 21 to 119 days dependent on the patients' initial viral load trajectory. The viral load set points were 4.28 ± 0.86 and 4.25 ± 0.87 log10 copies per milliliter (P = 0.08), respectively, as determined by our model and an empirical method, suggesting an excellent agreement between the old and new methods. We provide a novel method to estimate viral load set point at the very early stage of HIV infection. Application of this model can accurately and reliably determine the set point, thus providing a new tool for physicians to better monitor early intervention strategies in acutely infected patients and scientists to rationally design preventative vaccine studies.

  7. Common fixed points in best approximation for Banach operator pairs with Ciric type I-contractions

    NASA Astrophysics Data System (ADS)

    Hussain, N.

    2008-02-01

    The common fixed point theorems, similar to those of Ciric [Lj.B. Ciric, On a common fixed point theorem of a Gregus type, Publ. Inst. Math. (Beograd) (N.S.) 49 (1991) 174-178; Lj.B. Ciric, On Diviccaro, Fisher and Sessa open questions, Arch. Math. (Brno) 29 (1993) 145-152; Lj.B. Ciric, On a generalization of Gregus fixed point theorem, Czechoslovak Math. J. 50 (2000) 449-458], Fisher and Sessa [B. Fisher, S. Sessa, On a fixed point theorem of Gregus, Internat. J. Math. Math. Sci. 9 (1986) 23-28], Jungck [G. Jungck, On a fixed point theorem of Fisher and Sessa, Internat. J. Math. Math. Sci. 13 (1990) 497-500] and Mukherjee and Verma [R.N. Mukherjee, V. Verma, A note on fixed point theorem of Gregus, Math. Japon. 33 (1988) 745-749], are proved for a Banach operator pair. As applications, common fixed point and approximation results for Banach operator pair satisfying Ciric type contractive conditions are obtained without the assumption of linearity or affinity of either T or I. Our results unify and generalize various known results to a more general class of noncommuting mappings.

  8. A maximum power point tracking algorithm for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Nelatury, Sudarshan R.; Gray, Robert

    2013-05-01

    The voltage and current characteristic of a photovoltaic (PV) cell is highly nonlinear and operating a PV cell for maximum power transfer has been a challenge for a long time. Several techniques have been proposed to estimate and track the maximum power point (MPP) in order to improve the overall efficiency of a PV panel. A strategic use of the mean value theorem permits obtaining an analytical expression for a point that lies in a close neighborhood of the true MPP. But hitherto, an exact solution in closed form for the MPP is not published. This problem can be formulated analytically as a constrained optimization, which can be solved using the Lagrange method. This method results in a system of simultaneous nonlinear equations. Solving them directly is quite difficult. However, we can employ a recursive algorithm to yield a reasonably good solution. In graphical terms, suppose the voltage current characteristic and the constant power contours are plotted on the same voltage current plane, the point of tangency between the device characteristic and the constant power contours is the sought for MPP. It is subject to change with the incident irradiation and temperature and hence the algorithm that attempts to maintain the MPP should be adaptive in nature and is supposed to have fast convergence and the least misadjustment. There are two parts in its implementation. First, one needs to estimate the MPP. The second task is to have a DC-DC converter to match the given load to the MPP thus obtained. Availability of power electronics circuits made it possible to design efficient converters. In this paper although we do not show the results from a real circuit, we use MATLAB to obtain the MPP and a buck-boost converter to match the load. Under varying conditions of load resistance and irradiance we demonstrate MPP tracking in case of a commercially available solar panel MSX-60. The power electronics circuit is simulated by PSIM software.

  9. Accuracy assessment of building point clouds automatically generated from iphone images

    NASA Astrophysics Data System (ADS)

    Sirmacek, B.; Lindenbergh, R.

    2014-06-01

    Low-cost sensor generated 3D models can be useful for quick 3D urban model updating, yet the quality of the models is questionable. In this article, we evaluate the reliability of an automatic point cloud generation method using multi-view iPhone images or an iPhone video file as an input. We register such automatically generated point cloud on a TLS point cloud of the same object to discuss accuracy, advantages and limitations of the iPhone generated point clouds. For the chosen example showcase, we have classified 1.23% of the iPhone point cloud points as outliers, and calculated the mean of the point to point distances to the TLS point cloud as 0.11 m. Since a TLS point cloud might also include measurement errors and noise, we computed local noise values for the point clouds from both sources. Mean (μ) and standard deviation (σ) of roughness histograms are calculated as (μ1 = 0.44 m., σ1 = 0.071 m.) and (μ2 = 0.025 m., σ2 = 0.037 m.) for the iPhone and TLS point clouds respectively. Our experimental results indicate possible usage of the proposed automatic 3D model generation framework for 3D urban map updating, fusion and detail enhancing, quick and real-time change detection purposes. However, further insights should be obtained first on the circumstances that are needed to guarantee a successful point cloud generation from smartphone images.

  10. Results of exploratory drilling at Point MacKenzie, Alaska, 1981

    USGS Publications Warehouse

    Patrick, Leslie

    1981-01-01

    The Matanuska-Susitna Borough anticipates industrial development near Point MacKenzie, Alaska. Because little hydrologic information is available for the area, the Borough contracted for the drilling of two test wells. It was found that: Both wells penetrated unconsolidated stratified clay, silt, sand, and gravel; each well penetrated a shallow unconfined and deeper confined aquifers; the water levels in the wells rise and fall with the tide; the chemical analyses indicate that the water quality meets the Alaska Drinking Water Standards, except for slightly high levels of manganese and pH; and the potential for saltwater intrusion should be evaluated as part of future studies. (USGS)

  11. Processing Uav and LIDAR Point Clouds in Grass GIS

    NASA Astrophysics Data System (ADS)

    Petras, V.; Petrasova, A.; Jeziorska, J.; Mitasova, H.

    2016-06-01

    Today's methods of acquiring Earth surface data, namely lidar and unmanned aerial vehicle (UAV) imagery, non-selectively collect or generate large amounts of points. Point clouds from different sources vary in their properties such as number of returns, density, or quality. We present a set of tools with applications for different types of points clouds obtained by a lidar scanner, structure from motion technique (SfM), and a low-cost 3D scanner. To take advantage of the vertical structure of multiple return lidar point clouds, we demonstrate tools to process them using 3D raster techniques which allow, for example, the development of custom vegetation classification methods. Dense point clouds obtained from UAV imagery, often containing redundant points, can be decimated using various techniques before further processing. We implemented and compared several decimation techniques in regard to their performance and the final digital surface model (DSM). Finally, we will describe the processing of a point cloud from a low-cost 3D scanner, namely Microsoft Kinect, and its application for interaction with physical models. All the presented tools are open source and integrated in GRASS GIS, a multi-purpose open source GIS with remote sensing capabilities. The tools integrate with other open source projects, specifically Point Data Abstraction Library (PDAL), Point Cloud Library (PCL), and OpenKinect libfreenect2 library to benefit from the open source point cloud ecosystem. The implementation in GRASS GIS ensures long term maintenance and reproducibility by the scientific community but also by the original authors themselves.

  12. The Atacama Cosmology Telescope: Development and preliminary results of point source observations

    NASA Astrophysics Data System (ADS)

    Fisher, Ryan P.

    2009-06-01

    The Atacama Cosmology Telescope (ACT) is a six meter diameter telescope designed to measure the millimeter sky with arcminute angular resolution. The instrument is currently conducting its third season of observations from Cerro Toco in the Chilean Andes. The primary science goal of the experiment is to expand our understanding of cosmology by mapping the temperature fluctuations of the Cosmic Microwave Background (CMB) at angular scales corresponding to multipoles up to [cursive l] ~ 10000. The primary receiver for current ACT observations is the Millimeter Bolometer Array Camera (MBAC). The instrument is specially designed to observe simultaneously at 148 GHz, 218 GHz and 277 GHz. To accomplish this, the camera has three separate detector arrays, each containing approximately 1000 detectors. After discussing the ACT experiment in detail, a discussion of the development and testing of the cold readout electronics for the MBAC is presented. Currently, the ACT collaboration is in the process of generating maps of the microwave sky using our first and second season observations. The analysis used to generate these maps requires careful data calibration to produce maps of the arcminute scale CMB temperature fluctuations. Tests and applications of several elements of the ACT calibrations are presented in the context of the second season observations. Scientific exploration has already begun on preliminary maps made using these calibrations. The final portion of this thesis is dedicated to discussing the point sources observed by the ACT. A discussion of the techniques used for point source detection and photometry is followed by a presentation of our current measurements of point source spectral indices.

  13. Water vapour condensation in a partly closed structure. Comparison between results obtained with an inside wet or dry bottom wall

    NASA Astrophysics Data System (ADS)

    Batina, Jean; Peyrous, René

    2018-04-01

    We are interested in the determination of the more significant parameters acting on the water vapour condensation in a partly closed structure, submitted to external constraints (temperature and humidity), in view to recover the generated droplets as an additional source of potable water. External temperature variations, by inducing temperature differences between outside and inside of the structure, lead to convective movements and thermal variations inside this structure. Through an orifice, these movements permit a renewing of the humid inner air and can lead to the condensation of the water vapour initially contained in the inner air volume and/or on the walls. With the above hypotheses, and by using a numerical simulation [1] based on the ambient air characteristics and a finite volumes method, it appears that condensed water quantities are mainly depending on the boundary conditions imposed. These conditions are: 1) dimensions of the structure; 2) external temperature and relative hygrometry; 3) the phase φ (T/RH) linking thermal and hydrometric conditions; 4) the air renewing and its hygrometry for each phase; and 5) for each case, the fact that the inside bottom wall can be wet or dry. The resulting condensed water vapour quantities obtained, for the width section, point out clearly that they are very depending on this phase φ (T/RH) which appears as the more significant parameter and can be modified by the presence or not of a thin layer of water vapour on the inside bottom wall. Condensation phenomenon could be increased if φ could be optimized.

  14. Non-Gimbaled Antenna Pointing

    NASA Technical Reports Server (NTRS)

    Vigil, Jeannine S.

    1997-01-01

    The small satellite community has been interested in accessing fixed ground stations for means of space-to-ground transmissions, although a problem arises from the limited global coverage. There is a growing interest for using the Space Network (SN) or Tracking and Data Relay Satellites (TDRS) as the primary support for communications because of the coverage it provides. This thesis will address the potential for satellite access of the Space Network with a non-gimbaled antenna configuration and low-power, coded transmission. The non-gimbaled antenna and the TDRS satellites, TDRS-East, TDRS-West, and TDRS-Zone of Exclusion, were configured in an orbital analysis software package called Satellite Tool Kit to emulate the three-dimensional position of the satellites. The access potential, which is the average number of contacts per day and the average time per contact, were obtained through simulations run over a 30-day period to gain all the possible orientations. The orbital altitude was varied from 600 km through 1200 km with the results being a function of orbital inclination angles varying from 20 deg through 100 deg and pointing half-angles of I0 deg through 40 deg. To compare the validity of the simulations, Jet Propulsion Laboratory granted the use of the TOPEX satellite. The TOPEX satellite was configured to emulate a spin-stabilized antenna with its communications antenna stowed in the zenith-pointing direction. This mimicked the antenna pointing spin-stabilized satellite in the simulations. To make valid comparisons, the TOPEX orbital parameters were entered into Satellite Tool Kit and simulated over five test times provided by Jet Propulsion Laboratory.

  15. The effect of a turbulent wake on the stagnation point. I - Skin friction results

    NASA Technical Reports Server (NTRS)

    Wilson, Dennis E.; Hanford, Anthony J.

    1990-01-01

    The response of a boundary layer in the stagnation region of a two-dimensional body to fluctuations in the freestream is examined. The analysis is restricted to laminar incompressible flow. The assumed form of the velocity distribution at the edge of the boundary layer represents both a pulsation of the incoming flow, and an oscillation of the stagnation point streamline. Both features are essential in accurately representing the effect which freestream spatial and temporal nonuniformities have upon the unsteady boundary layer. Finally, a simple model is proposed which relates the characteristic parameters in a turbulent wake to the unsteady boundary-layer edge velocity. Numerical results are presented for both an arbitrary two-dimensional geometry and a circular cylinder.

  16. Outdoor Illegal Construction Identification Algorithm Based on 3D Point Cloud Segmentation

    NASA Astrophysics Data System (ADS)

    An, Lu; Guo, Baolong

    2018-03-01

    Recently, various illegal constructions occur significantly in our surroundings, which seriously restrict the orderly development of urban modernization. The 3D point cloud data technology is used to identify the illegal buildings, which could address the problem above effectively. This paper proposes an outdoor illegal construction identification algorithm based on 3D point cloud segmentation. Initially, in order to save memory space and reduce processing time, a lossless point cloud compression method based on minimum spanning tree is proposed. Then, a ground point removing method based on the multi-scale filtering is introduced to increase accuracy. Finally, building clusters on the ground can be obtained using a region growing method, as a result, the illegal construction can be marked. The effectiveness of the proposed algorithm is verified using a publicly data set collected from the International Society for Photogrammetry and Remote Sensing (ISPRS).

  17. Dynamics of Multibody Systems Near Lagrangian Points

    NASA Astrophysics Data System (ADS)

    Wong, Brian

    This thesis examines the dynamics of a physically connected multi-spacecraft system in the vicinity of the Lagrangian points of a Circular Restricted Three-Body System. The spacecraft system is arranged in a wheel-spoke configuration with smaller and less massive satellites connected to a central hub using truss/beams or tether connectors. The kinematics of the system is first defined, and the kinetic, gravitational potential energy and elastic potential energy of the system are derived. The Assumed Modes Method is used to discretize the continuous variables of the system, and a general set of ordinary differential equations describing the dynamics of the connectors and the central hub are obtained using the Lagrangian method. The flexible body dynamics of the tethered and truss connected systems are examined using numerical simulations. The results show that these systems experienced only small elastic deflections when they are naturally librating or rotating at moderate angular velocities, and these deflections have relatively small effect on the attitude dynamics of the systems. Based on these results, it is determined that the connectors can be modeled as rigid when only the attitude dynamics of the system is of interest. The equations of motion of rigid satellites stationed at the Lagrangian points are linearized, and the stability conditions of the satellite are obtained from the linear equations. The required conditions are shown to be similar to those of geocentric satellites. Study of the linear equations also revealed the resonant conditions of rigid Lagrangian point satellites, when a librational natural frequency of the satellite matches the frequency of its station-keeping orbit leading to large attitude motions. For tethered satellites, the linear analysis shows that the tethers are in stable equilibrium when they lie along a line joining the two primary celestial bodies of the Three-Body System. Numerical simulations are used to study the long term

  18. Change Analysis in Structural Laser Scanning Point Clouds: The Baseline Method

    PubMed Central

    Shen, Yueqian; Lindenbergh, Roderik; Wang, Jinhu

    2016-01-01

    A method is introduced for detecting changes from point clouds that avoids registration. For many applications, changes are detected between two scans of the same scene obtained at different times. Traditionally, these scans are aligned to a common coordinate system having the disadvantage that this registration step introduces additional errors. In addition, registration requires stable targets or features. To avoid these issues, we propose a change detection method based on so-called baselines. Baselines connect feature points within one scan. To analyze changes, baselines connecting corresponding points in two scans are compared. As feature points either targets or virtual points corresponding to some reconstructable feature in the scene are used. The new method is implemented on two scans sampling a masonry laboratory building before and after seismic testing, that resulted in damages in the order of several centimeters. The centres of the bricks of the laboratory building are automatically extracted to serve as virtual points. Baselines connecting virtual points and/or target points are extracted and compared with respect to a suitable structural coordinate system. Changes detected from the baseline analysis are compared to a traditional cloud to cloud change analysis demonstrating the potential of the new method for structural analysis. PMID:28029121

  19. Change Analysis in Structural Laser Scanning Point Clouds: The Baseline Method.

    PubMed

    Shen, Yueqian; Lindenbergh, Roderik; Wang, Jinhu

    2016-12-24

    A method is introduced for detecting changes from point clouds that avoids registration. For many applications, changes are detected between two scans of the same scene obtained at different times. Traditionally, these scans are aligned to a common coordinate system having the disadvantage that this registration step introduces additional errors. In addition, registration requires stable targets or features. To avoid these issues, we propose a change detection method based on so-called baselines. Baselines connect feature points within one scan. To analyze changes, baselines connecting corresponding points in two scans are compared. As feature points either targets or virtual points corresponding to some reconstructable feature in the scene are used. The new method is implemented on two scans sampling a masonry laboratory building before and after seismic testing, that resulted in damages in the order of several centimeters. The centres of the bricks of the laboratory building are automatically extracted to serve as virtual points. Baselines connecting virtual points and/or target points are extracted and compared with respect to a suitable structural coordinate system. Changes detected from the baseline analysis are compared to a traditional cloud to cloud change analysis demonstrating the potential of the new method for structural analysis.

  20. Comparison of Theoretical Stresses and Deflections of Multicell Wings with Experimental Results Obtained from Plastic Models

    NASA Technical Reports Server (NTRS)

    Zender, George W

    1956-01-01

    The experimental deflections and stresses of six plastic multicell-wing models of unswept, delta, and swept plan form are presented and compared with previously published theoretical results obtained by the electrical analog method. The comparisons indicate that the theory is reliable except for the evaluation of stresses in the vicinity of the leading edge of delta wings and the leading and trailing edges of swept wings. The stresses in these regions are questionable, apparently because of simplifications employed in idealizing the actual structure for theoretical purposes and because of local effects of concentrated loads.

  1. Concentration of point defects in 4H-SiC characterized by a magnetic measurement

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Peng, B.; Jia, R. X., E-mail: rxjia@mail.xidian.edu.cn; Wang, Y. T.

    A magnetic method is presented to characterize the concentration of point defects in silicon carbide. In this method, the concentration of common charged point defects, which is related to the density of paramagnetic centers, is determined by fitting the paramagnetic component of the specimen to the Brillouin function. Several parameters in the Brillouin function can be measured such as: the g-factor can be obtained from electron spin resonance spectroscopy, and the magnetic moment of paramagnetic centers can be obtained from positron lifetime spectroscopy combined with a first-principles calculation. To evaluate the characterization method, silicon carbide specimens with different concentrations ofmore » point defects are prepared with aluminum ion implantation. The fitting results of the densities of paramagnetic centers for the implanted doses of 1 × 10{sup 14} cm{sup −2}, 1 × 10{sup 15} cm{sup −2} and 1 × 10{sup 16} cm{sup −2} are 6.52 × 10{sup 14}/g, 1.14 × 10{sup 15}/g and 9.45 × 10{sup 14}/g, respectively. The same trends are also observed for the S-parameters in the Doppler broadening spectra. It is shown that this method is an accurate and convenient way to obtain the concentration of point defects in 4H-SiC.« less

  2. Earth-Moon Libration Point Orbit Stationkeeping: Theory, Modeling and Operations

    NASA Technical Reports Server (NTRS)

    Folta, David C.; Pavlak, Thomas A.; Haapala, Amanda F.; Howell, Kathleen C.; Woodard, Mark A.

    2013-01-01

    Collinear Earth-Moon libration points have emerged as locations with immediate applications. These libration point orbits are inherently unstable and must be maintained regularly which constrains operations and maneuver locations. Stationkeeping is challenging due to relatively short time scales for divergence effects of large orbital eccentricity of the secondary body, and third-body perturbations. Using the Acceleration Reconnection and Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) mission orbit as a platform, the fundamental behavior of the trajectories is explored using Poincare maps in the circular restricted three-body problem. Operational stationkeeping results obtained using the Optimal Continuation Strategy are presented and compared to orbit stability information generated from mode analysis based in dynamical systems theory.

  3. Mesoporous silicon oxide films and their uses as templates in obtaining nanostructured conductive polymers

    NASA Astrophysics Data System (ADS)

    Salgado, R.; Arteaga, G. C.; Arias, J. M.

    2018-04-01

    Obtaining conductive polymers (CPs) for the manufacture of OLEDs, solar cells, electrochromic devices, sensors, etc., has been possible through the use of electrochemical techniques that allow obtaining films of controlled thickness with positive results in different applications. Current trends point towards the manufacture of nanomaterials, and therefore it is necessary to develop methods that allow obtaining CPs with nanostructured morphology. This is possible by using a porous template to allow the growth of the polymeric materials. However, prior and subsequent treatments are required to separate the material from the template so that it can be evaluated in the applications mentioned above. This is why mesoporous silicon oxide films (template) are essential for the synthesis of nanostructured polymers since both the template and the polymer are obtained on the electrode surface, and therefore it is not necessary to separate the material from the template. Thus, the material can be evaluated directly in the applications mentioned above. The dimensions of the resulting nanostructures will depend on the power, time and technique used for electropolymerization as well as the monomer and the surfactant of the mesoporous film.

  4. Precise aircraft single-point positioning using GPS post-mission orbits and satellite clock corrections

    NASA Astrophysics Data System (ADS)

    Lachapelle, G.; Cannon, M. E.; Qiu, W.; Varner, C.

    1996-09-01

    Aircraft single point position accuracy is assessed through a comparison of the single point coordinates with corresponding DGPS-derived coordinates. The platform utilized for this evaluation is a Naval Air Warfare Center P-3 Orion aircraft. Data was collected over a period of about 40 hours, spread over six days, off Florida's East Coast in July 94, using DGPS reference stations in Jacksonville, FL, and Warminster, PA. The analysis of results shows that the consistency between aircraft single point and DGPS coordinates obtained in single point positioning mode and DGPS mode is about 1 m (rms) in latitude and longitude, and 2 m (rms) in height, with instantaneous errors of up to a few metres due to the effect of the ionosphere on the single point L1 solutions.

  5. Robust point matching via vector field consensus.

    PubMed

    Jiayi Ma; Ji Zhao; Jinwen Tian; Yuille, Alan L; Zhuowen Tu

    2014-04-01

    In this paper, we propose an efficient algorithm, called vector field consensus, for establishing robust point correspondences between two sets of points. Our algorithm starts by creating a set of putative correspondences which can contain a very large number of false correspondences, or outliers, in addition to a limited number of true correspondences (inliers). Next, we solve for correspondence by interpolating a vector field between the two point sets, which involves estimating a consensus of inlier points whose matching follows a nonparametric geometrical constraint. We formulate this a maximum a posteriori (MAP) estimation of a Bayesian model with hidden/latent variables indicating whether matches in the putative set are outliers or inliers. We impose nonparametric geometrical constraints on the correspondence, as a prior distribution, using Tikhonov regularizers in a reproducing kernel Hilbert space. MAP estimation is performed by the EM algorithm which by also estimating the variance of the prior model (initialized to a large value) is able to obtain good estimates very quickly (e.g., avoiding many of the local minima inherent in this formulation). We illustrate this method on data sets in 2D and 3D and demonstrate that it is robust to a very large number of outliers (even up to 90%). We also show that in the special case where there is an underlying parametric geometrical model (e.g., the epipolar line constraint) that we obtain better results than standard alternatives like RANSAC if a large number of outliers are present. This suggests a two-stage strategy, where we use our nonparametric model to reduce the size of the putative set and then apply a parametric variant of our approach to estimate the geometric parameters. Our algorithm is computationally efficient and we provide code for others to use it. In addition, our approach is general and can be applied to other problems, such as learning with a badly corrupted training data set.

  6. Environmental genotoxicity evaluation using cytogenetic end points in wild rodents.

    PubMed Central

    de Souza Bueno, A M; de Bragança Pereira, C A; Rabello-Gay, M N

    2000-01-01

    We analyzed cytogenetic end points in three populations of two species of wild rodents--Akodon montensis and Oryzomys nigripes--living in an industrial, an agricultural, and a preservation area at the Itajaí Valley, state of Santa Catarina, Brazil. Our purpose was to evaluate the performance of the following end points in the establishment of a genotoxic profile of each area: the polychromatic/normochromatic cell ratio; the mitotic index; the frequency of micronucleated cells both in the bone marrow and peripheral blood; and the frequency of cells with chromosome aberrations in the bone marrow. Preparations were obtained using conventional cytogenetic techniques. The results showed a) the role of the end points used as biomarkers in the early detection of genotoxic agents and in the identification of species and populations at higher risk; b) the difference in sensitivity of the species selected as bioindicators in relation to the cytogenetic end points analyzed; c) the need to use at least two sympatric species to detect the presence of genotoxins in each locality; and d) the need to use several end points when trying to establish a genotoxic profile of an area. PMID:11133397

  7. Surface Fitting Filtering of LIDAR Point Cloud with Waveform Information

    NASA Astrophysics Data System (ADS)

    Xing, S.; Li, P.; Xu, Q.; Wang, D.; Li, P.

    2017-09-01

    Full-waveform LiDAR is an active technology of photogrammetry and remote sensing. It provides more detailed information about objects along the path of a laser pulse than discrete-return topographic LiDAR. The point cloud and waveform information with high quality can be obtained by waveform decomposition, which could make contributions to accurate filtering. The surface fitting filtering method with waveform information is proposed to present such advantage. Firstly, discrete point cloud and waveform parameters are resolved by global convergent Levenberg Marquardt decomposition. Secondly, the ground seed points are selected, of which the abnormal ones are detected by waveform parameters and robust estimation. Thirdly, the terrain surface is fitted and the height difference threshold is determined in consideration of window size and mean square error. Finally, the points are classified gradually with the rising of window size. The filtering process is finished until window size is larger than threshold. The waveform data in urban, farmland and mountain areas from "WATER (Watershed Allied Telemetry Experimental Research)" are selected for experiments. Results prove that compared with traditional method, the accuracy of point cloud filtering is further improved and the proposed method has highly practical value.

  8. Utility of the T-SPOT®.TB test's borderline category to increase test resolution for results around the cut-off point.

    PubMed

    Rego, Karen; Pereira, Kristen; MacDougall, James; Cruikshank, William

    2018-01-01

    Accurate identification of individuals with TB infection, is required to achieve the WHO's End TB Strategy goals. While there is general acceptance that the T-SPOT.TB test borderline category provides an opportunity to increase test resolution of results around the test cut-off point, this has not been investigated. 645,947 tests were analyzed to determine frequency of borderline results, effect of age and time between tests and associations between subjects' clinical risk factors and retest results. 645,947 tests produced 93.5% negatives, 4% positives, 0.6% invalids, and 1.8% borderlines. Within the borderline results, 5044 were repeated, with 59.2%, 20.0% and 20.2% resolving to negative, positive and borderline, respectively. Age of subject did not affect retest results; however, time between tests indicated that retest resolution occurred with greatest frequency after 90 days. TB risk factors were provided for 2640 subjects and 17% of low risk subjects with a high initial borderline resolved to negative while 27.6% of subjects with high risk and an initial low borderline resolved to positive, suggesting that these subjects could have been inappropriately classified if using a single cut-off point test with no borderline category. This study demonstrates the utility of the T-SPOT.TB test's borderline category to increase test resolution around the test cut-off point. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. obtain3D

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Eftink, Benjamin Paul; Maloy, Stuart Andrew

    This computer code uses the concept of the parallax to compute the x, y and z coordinates of points found using transmission electron microscopy (TEM), or any transmission imaging technique, using two images, each taken at a different perspective of the region containing the points. Points correspond, but are not limited, to the center of cavities or precipitates, positions of irradiation black dot damage, positions along a dislocation line, or positions along where an interface meets a free surface. The code allows the user to visualize the features containing the points in three dimensions. Features can include dislocations, interfaces, cavities,more » precipitates, inclusions etc. The x, y and z coordinates of the points are output in a text file as well. The program can also combine the x, y and z coordinates of the points with crystallographic directional information from diffraction pattern(s) to calculate dislocation line directions and interface plane normals.« less

  10. Imaging of biophoton emission from electrostimulated skin acupuncture point jg4: effect of light enhancers.

    PubMed

    Slawinski, Janusz; Gorski, Zbigniew

    2008-05-01

    Using an ultrasensitive CCD camera, an extremely low light intensity from the acupuncture-sensitive point JG4 at the left hand was recorded. As the intensity of the light was very weak and the time of electrostimulation exceeded the recommended period, the quality of biophoton images was poor. Chemiluminescent and fluorescent hydrophilic, hydrophobic and amphyphilic molecular probes were used to: (i) ensure penetration of probes into skin, (ii) enhance the intensity of BP emission, (iii) shorten time and (iv) obtain information about mechanisms of biophotons generation in EAP-sensitive points and channels. The results obtained partially fulfilled expectations and indicate on the necessity to elaborate special techniques of probes deposition on the skin.

  11. Regional mapping of soil parent material by machine learning based on point data

    NASA Astrophysics Data System (ADS)

    Lacoste, Marine; Lemercier, Blandine; Walter, Christian

    2011-10-01

    A machine learning system (MART) has been used to predict soil parent material (SPM) at the regional scale with a 50-m resolution. The use of point-specific soil observations as training data was tested as a replacement for the soil maps introduced in previous studies, with the aim of generating a more even distribution of training data over the study area and reducing information uncertainty. The 27,020-km 2 study area (Brittany, northwestern France) contains mainly metamorphic, igneous and sedimentary substrates. However, superficial deposits (aeolian loam, colluvial and alluvial deposits) very often represent the actual SPM and are typically under-represented in existing geological maps. In order to calibrate the predictive model, a total of 4920 point soil descriptions were used as training data along with 17 environmental predictors (terrain attributes derived from a 50-m DEM, as well as emissions of K, Th and U obtained by means of airborne gamma-ray spectrometry, geological variables at the 1:250,000 scale and land use maps obtained by remote sensing). Model predictions were then compared: i) during SPM model creation to point data not used in model calibration (internal validation), ii) to the entire point dataset (point validation), and iii) to existing detailed soil maps (external validation). The internal, point and external validation accuracy rates were 56%, 81% and 54%, respectively. Aeolian loam was one of the three most closely predicted substrates. Poor prediction results were associated with uncommon materials and areas with high geological complexity, i.e. areas where existing maps used for external validation were also imprecise. The resultant predictive map turned out to be more accurate than existing geological maps and moreover indicated surface deposits whose spatial coverage is consistent with actual knowledge of the area. This method proves quite useful in predicting SPM within areas where conventional mapping techniques might be too

  12. Evaluation of a statistics-based Ames mutagenicity QSAR model and interpretation of the results obtained.

    PubMed

    Barber, Chris; Cayley, Alex; Hanser, Thierry; Harding, Alex; Heghes, Crina; Vessey, Jonathan D; Werner, Stephane; Weiner, Sandy K; Wichard, Joerg; Giddings, Amanda; Glowienke, Susanne; Parenty, Alexis; Brigo, Alessandro; Spirkl, Hans-Peter; Amberg, Alexander; Kemper, Ray; Greene, Nigel

    2016-04-01

    The relative wealth of bacterial mutagenicity data available in the public literature means that in silico quantitative/qualitative structure activity relationship (QSAR) systems can readily be built for this endpoint. A good means of evaluating the performance of such systems is to use private unpublished data sets, which generally represent a more distinct chemical space than publicly available test sets and, as a result, provide a greater challenge to the model. However, raw performance metrics should not be the only factor considered when judging this type of software since expert interpretation of the results obtained may allow for further improvements in predictivity. Enough information should be provided by a QSAR to allow the user to make general, scientifically-based arguments in order to assess and overrule predictions when necessary. With all this in mind, we sought to validate the performance of the statistics-based in vitro bacterial mutagenicity prediction system Sarah Nexus (version 1.1) against private test data sets supplied by nine different pharmaceutical companies. The results of these evaluations were then analysed in order to identify findings presented by the model which would be useful for the user to take into consideration when interpreting the results and making their final decision about the mutagenic potential of a given compound. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Reference-point-independent dynamics of molecular liquids and glasses in the tensorial formalism

    NASA Astrophysics Data System (ADS)

    Schilling, Rolf

    2002-05-01

    We apply the tensorial formalism to the dynamics of molecular liquids and glasses. This formalism separates the degrees of freedom into translational and orientational ones. Using the Mori-Zwanzig projection formalism, the equations of motion for the tensorial density correlators Slmn,l'm'n'(q-->,t) are derived. For this we show how to choose the slow variables such that the resulting Mori-Zwanzig equations are covariant under a change of the reference point of the body fixed frame. We also prove that the memory kernels obtained from mode-coupling theory (MCT) including all approximations preserve the covariance. This covariance makes, e.g., the glass transition point, the two universal scaling laws and particularly the corresponding exponents independent on the reference point and on the mass and moments of inertia, i.e., they only depend on the properties of the potential energy landscape. Finally, we show that the corresponding MCT questions for linear molecules can be obtained from those for arbitrary molecules and that they differ from earlier equations that are not covariant.

  14. The pH-dependent surface charging and points of zero charge: V. Update.

    PubMed

    Kosmulski, Marek

    2011-01-01

    The points of zero charge (PZC) and isoelectric points (IEP) from the recent literature are discussed. This study is an update of the previous compilation [M. Kosmulski, Surface Charging and Points of Zero Charge, CRC, Boca Raton, FL, 2009] and of its previous update [J. Colloid Interface Sci. 337 (2009) 439]. In several recent publications, the terms PZC/IEP have been used outside their usual meaning. Only the PZC/IEP obtained according to the methods recommended by the present author are reported in this paper, and the other results are ignored. PZC/IEP of albite, sepiolite, and sericite, which have not been studied before, became available over the past 2 years. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. Orbit Determination Error Analysis Results for the Triana Sun-Earth L2 Libration Point Mission

    NASA Technical Reports Server (NTRS)

    Marr, G.

    2003-01-01

    Using the NASA Goddard Space Flight Center's Orbit Determination Error Analysis System (ODEAS), orbit determination error analysis results are presented for all phases of the Triana Sun-Earth L1 libration point mission and for the science data collection phase of a future Sun-Earth L2 libration point mission. The Triana spacecraft was nominally to be released by the Space Shuttle in a low Earth orbit, and this analysis focuses on that scenario. From the release orbit a transfer trajectory insertion (TTI) maneuver performed using a solid stage would increase the velocity be approximately 3.1 km/sec sending Triana on a direct trajectory to its mission orbit. The Triana mission orbit is a Sun-Earth L1 Lissajous orbit with a Sun-Earth-vehicle (SEV) angle between 4.0 and 15.0 degrees, which would be achieved after a Lissajous orbit insertion (LOI) maneuver at approximately launch plus 6 months. Because Triana was to be launched by the Space Shuttle, TTI could potentially occur over a 16 orbit range from low Earth orbit. This analysis was performed assuming TTI was performed from a low Earth orbit with an inclination of 28.5 degrees and assuming support from a combination of three Deep Space Network (DSN) stations, Goldstone, Canberra, and Madrid and four commercial Universal Space Network (USN) stations, Alaska, Hawaii, Perth, and Santiago. These ground stations would provide coherent two-way range and range rate tracking data usable for orbit determination. Larger range and range rate errors were assumed for the USN stations. Nominally, DSN support would end at TTI+144 hours assuming there were no USN problems. Post-TTI coverage for a range of TTI longitudes for a given nominal trajectory case were analyzed. The orbit determination error analysis after the first correction maneuver would be generally applicable to any libration point mission utilizing a direct trajectory.

  16. Do dam constructions in a Vietnamese river basin result in change points in hydrologic regime and how reliable are different methods?

    NASA Astrophysics Data System (ADS)

    Vu, Tinh Thi; Kiesel, Jens; Guse, Bjoern; Fohrer, Nicola

    2017-04-01

    The damming of rivers causes one of the most considerable impacts of our society on the riverine environment. More than 50% of the world's streams and rivers are currently impounded by dams before reaching the oceans. The construction of dams is of high importance in developing and emerging countries, i.e. for power generation and water storage. In the Vietnamese Vu Gia - Thu Bon Catchment (10,350 km2), about 23 dams were built during the last decades and store approximately 2,156 billion m3 of water. The water impoundment in 10 dams in upstream regions amounts to 17 % of the annual discharge volume. It is expected that impacts from these dams have altered the natural flow regime. However, up to now it is unclear how the flow regime was altered. For this, it needs to be investigated at what point in time these changes became significant and detectable. Many approaches exist to detect changes in stationary or consistency of hydrological records using statistical analysis of time series for the pre- and post-dam period. The objective of this study is to reliably detect and assess hydrologic shifts occurring in the discharge regime of an anthropogenically influenced river basin, mainly affected by the construction of dams. To achieve this, we applied nine available change-point tests to detect change in mean, variance and median on the daily and annual discharge records at two main gauges of the basin. The tests yield conflicting results: The majority of tests found abrupt changes that coincide with the damming-period, while others did not. To interpret how significant the changes in discharge regime are, and to which different properties of the time series each test responded, we calculated Indicators of Hydrologic Alteration (IHAs) for the time period before and after the detected change points. From the results, we can deduce, that the change point tests are influenced in different levels by different indicator groups (magnitude, duration, frequency, etc) and that

  17. The relative ease of obtaining a dermatologic appointment in Boston: how methods drive results.

    PubMed

    Weingold, David Howard; Lack, Michael Dweight; Yanowitz, Karen Leslie

    2009-06-01

    Recent reports have indicated long wait times for dermatologic appointments even for changing moles. Our objective was to determine the wait time for a person willing to make multiple calls and accept an appointment from any dermatologist at any satellite location for a changing mole from a dermatologist who advertised in a Boston, MA, telephone book. We telephoned each practice listed in a Boston, MA, telephone book. Patients making one call to each dermatologic practice on average obtained an appointment in 18 days. Patients calling two practices were offered an appointment on average in 7 days. Patients calling 3 practices were also offered an appointment in 1 week. We only telephoned practices listed in a Boston, MA, telephone book and we only surveyed one urban area. These results suggest that a reasonable concerned patient who was willing to make multiple calls to different providers in Boston, MA, can be seen in a timely fashion.

  18. Point specificity in acupuncture

    PubMed Central

    2012-01-01

    The existence of point specificity in acupuncture is controversial, because many acupuncture studies using this principle to select control points have found that sham acupoints have similar effects to those of verum acupoints. Furthermore, the results of pain-related studies based on visual analogue scales have not supported the concept of point specificity. In contrast, hemodynamic, functional magnetic resonance imaging and neurophysiological studies evaluating the responses to stimulation of multiple points on the body surface have shown that point-specific actions are present. This review article focuses on clinical and laboratory studies supporting the existence of point specificity in acupuncture and also addresses studies that do not support this concept. Further research is needed to elucidate the point-specific actions of acupuncture. PMID:22373514

  19. 2-Point microstructure archetypes for improved elastic properties

    NASA Astrophysics Data System (ADS)

    Adams, Brent L.; Gao, Xiang

    2004-01-01

    Rectangular models of material microstructure are described by their 1- and 2-point (spatial) correlation statistics of placement of local state. In the procedure described here the local state space is described in discrete form; and the focus is on placement of local state within a finite number of cells comprising rectangular models. It is illustrated that effective elastic properties (generalized Hashin Shtrikman bounds) can be obtained that are linear in components of the correlation statistics. Within this framework the concept of an eigen-microstructure within the microstructure hull is useful. Given the practical innumerability of the microstructure hull, however, we introduce a method for generating a sequence of archetypes of eigen-microstructure, from the 2-point correlation statistics of local state, assuming that the 1-point statistics are stationary. The method is illustrated by obtaining an archetype for an imaginary two-phase material where the objective is to maximize the combination C_{xxxx}^{*} + C_{xyxy}^{*}

  20. Interface with weakly singular points always scatter

    NASA Astrophysics Data System (ADS)

    Li, Long; Hu, Guanghui; Yang, Jiansheng

    2018-07-01

    Assume that a bounded scatterer is embedded into an infinite homogeneous isotropic background medium in two dimensions. The refractive index function is supposed to be piecewise constant. If the scattering interface contains a weakly singular point, we prove that the scattered field cannot vanish identically. This implies the absence of non-scattering energies for piecewise analytic interfaces with one singular point. Local uniqueness is obtained for shape identification problems in inverse medium scattering with a single far-field pattern.

  1. Method of and apparatus for generating an interstitial point in a data stream having an even number of data points

    NASA Technical Reports Server (NTRS)

    Edwards, T. R. (Inventor)

    1985-01-01

    Apparatus for doubling the data density rate of an analog to digital converter or doubling the data density storage capacity of a memory deviced is discussed. An interstitial data point midway between adjacent data points in a data stream having an even number of equal interval data points is generated by applying a set of predetermined one-dimensional convolute integer coefficients which can include a set of multiplier coefficients and a normalizer coefficient. Interpolator means apply the coefficients to the data points by weighting equally on each side of the center of the even number of equal interval data points to obtain an interstital point value at the center of the data points. A one-dimensional output data set, which is twice as dense as a one-dimensional equal interval input data set, can be generated where the output data set includes interstitial points interdigitated between adjacent data points in the input data set. The method for generating the set of interstital points is a weighted, nearest-neighbor, non-recursive, moving, smoothing averaging technique, equivalent to applying a polynomial regression calculation to the data set.

  2. Working harder to obtain more snack foods when wanting to eat less.

    PubMed

    Giesen, Janneke C A H; Havermans, Remco C; Nederkoorn, Chantal; Strafaci, Silvana; Jansen, Anita

    2009-01-01

    This study investigates individual differences in the reinforcing value of snack food. More specifically, it was investigated whether differences in restraint status are associated with differences in working for high-caloric snack food. Thirty-six unrestrained non-dieters, twenty restrained non-dieters and fifteen current dieters performed a concurrent schedules task in which they had the option to work for points for either snack food or fruit and vegetables. By progressively increasing the "price" of the snack foods (i.e., the amount of work required to obtain extra snack points) the relative reinforcing value of snack food was determined. As hypothesized, restrained non-dieters worked harder and current dieters worked less hard to obtain snack food as compared to unrestrained non-dieters.

  3. Preliminary Study on Appearance-Based Detection of Anatomical Point Landmarks in Body Trunk CT Images

    NASA Astrophysics Data System (ADS)

    Nemoto, Mitsutaka; Nomura, Yukihiro; Hanaoka, Shohei; Masutani, Yoshitaka; Yoshikawa, Takeharu; Hayashi, Naoto; Yoshioka, Naoki; Ohtomo, Kuni

    Anatomical point landmarks as most primitive anatomical knowledge are useful for medical image understanding. In this study, we propose a detection method for anatomical point landmark based on appearance models, which include gray-level statistical variations at point landmarks and their surrounding area. The models are built based on results of Principal Component Analysis (PCA) of sample data sets. In addition, we employed generative learning method by transforming ROI of sample data. In this study, we evaluated our method with 24 data sets of body trunk CT images and obtained 95.8 ± 7.3 % of the average sensitivity in 28 landmarks.

  4. Saturn gravity results obtained from Pioneer 11 tracking data and earth-based Saturn satellite data

    NASA Technical Reports Server (NTRS)

    Null, G. W.; Lau, E. L.; Biller, E. D.; Anderson, J. D.

    1981-01-01

    Improved gravity coefficients for Saturn, its satellites and rings are calculated on the basis of a combination of Pioneer 11 spacecraft Doppler tracking data and earth-based determinations of Saturn natural satellite apse and node rates. Solutions are first obtained separately from the coherent Doppler tracking data obtained for the interval from August 20 to September 4, surrounding the time of closest approach, with the effects of solar plasma on radio signal propagation taken into account, and from secular rates for Mimas, Enceladus, Tethys, Dione, Rhea and Titan determined from astrometric data by Kozai (1957, 1976) and Garcia (1972). Combination of the data by the use of the Pioneer solution and corresponding unadjusted covariance matrix as a priori information for a secular rate analysis results in values for the total ring mass of essentially zero at a standard error level of 1.7 x 10 to the -6th Saturn masses, a ratio of solar mass to that of the Saturn system of 3498.09 + or - 0.22, masses of Rhea, Titan and Iapetus of 4.0 + or - 0.9, 238.8 + or - 3, and 3.4 + or - 1.3 x 10 to the -6th Saturn masses, respectively, and second and fourth zonal harmonics of 16,479 + or - 18 and -937 + or - 38, respectively. The harmonic coefficients are noted to be important as boundary conditions in the modeling of the Saturn interior.

  5. CUTOFF POINT OF THE PHASE ANGLE IN PRE-RADIOTHERAPY CANCER PATIENTS.

    PubMed

    Souza Thompson Motta, Rachel; Alves Castanho, Ivany; Guillermo Coca Velarde, Luis

    2015-11-01

    malnutrition is a common complication for cancer patients. The phase angle (PA), direct measurement of bioelectrical impedance analysis (BIA), has been considered a predictor of body cell mass and prognostic indicator. Cutoff points for phase angle (PA) associated with nutritional risk in cancer patients have not been determined yet. assess the possibility of determining the cutoff point for PA to identify nutritional risk in pre-radiotherapy cancer patients. sample group: Patients from both genders diagnosed with cancer and sent for ambulatory radiotherapy. body mass index (BMI), percentage of weight loss (% WL), mid-arm circumference (MAC), triceps skinfold thickness (TST), mid-arm muscle circumference (MAMC), mid-arm muscle area (MAMA), score and categorical assessment obtained using the Patient-Generated Subjective Global Assessment (PG-SGA) form, PA and standardized phase angle (SPA). Kappa coefficient was used to test the degree of agreement between the diagnoses of nutritional risk obtained from several different methods of nutritional assessment. Cutoff points for the PA through anthropometric indicators and PG-SGA were determined by using Receiver Operating Characteristic (ROC) curves, and patient survival was analyzed with the Cox regression method. the cutoff points with the greatest discriminatory power were those obtained from BMI (5.2) and the categorical assessment of PG-SGA (5.4). The diagnosis obtained using these cutoff points showed a significant association with risk of death for the patients in the sample group. we recommend using the cutoff point 5.2 for the PA as a criterion for identifying nutritional risk in pre-radiotherapy cancer patients. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  6. UVIS Photometric Zero Points

    NASA Astrophysics Data System (ADS)

    Kalirai, Jason

    2009-07-01

    This proposal obtains the photometric zero points in 53 of the 62 UVIS/WFC3 filters: the 18 broad-band filters, 8 medium-band filters, 16 narrow-band filters, and 11 of the 20 quad filters {those being used in cycle 17}. The observations will be primary obtained by observing the hot DA white dwarf standards GD153 and G191-B2B. A redder secondary standard, P330E, will be observed in a subset of the filters to provide color corrections. Repeat observations in 16 of the most widely used cycle 17 filters will be obtained once per month for the first three months, and then once every second month for the duration of cycle 17, alternating and depending on target availability. These observations will enable monitoring of the stability of the photometric system. Photometric transformation equations will be calculated by comparing the photometry of stars in two globular clusters, 47 Tuc and NGC 2419, to previous measurements with other telescopes/instruments.

  7. A novel infrared small moving target detection method based on tracking interest points under complicated background

    NASA Astrophysics Data System (ADS)

    Dong, Xiabin; Huang, Xinsheng; Zheng, Yongbin; Bai, Shengjian; Xu, Wanying

    2014-07-01

    Infrared moving target detection is an important part of infrared technology. We introduce a novel infrared small moving target detection method based on tracking interest points under complicated background. Firstly, Difference of Gaussians (DOG) filters are used to detect a group of interest points (including the moving targets). Secondly, a sort of small targets tracking method inspired by Human Visual System (HVS) is used to track these interest points for several frames, and then the correlations between interest points in the first frame and the last frame are obtained. Last, a new clustering method named as R-means is proposed to divide these interest points into two groups according to the correlations, one is target points and another is background points. In experimental results, the target-to-clutter ratio (TCR) and the receiver operating characteristics (ROC) curves are computed experimentally to compare the performances of the proposed method and other five sophisticated methods. From the results, the proposed method shows a better discrimination of targets and clutters and has a lower false alarm rate than the existing moving target detection methods.

  8. Measurement results obtained from air quality monitoring system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Turzanski, P.K.; Beres, R.

    1995-12-31

    An automatic system of air pollution monitoring operates in Cracow since 1991. The organization, assembling and start-up of the network is a result of joint efforts of the US Environmental Protection Agency and the Cracow environmental protection service. At present the automatic monitoring network is operated by the Provincial Inspection of Environmental Protection. There are in total seven stationary stations situated in Cracow to measure air pollution. These stations are supported continuously by one semi-mobile (transportable) station. It allows to modify periodically the area under investigation and therefore the 3-dimensional picture of creation and distribution of air pollutants within Cracowmore » area could be more intelligible.« less

  9. Fragmentation Point Detection of JPEG Images at DHT Using Validator

    NASA Astrophysics Data System (ADS)

    Mohamad, Kamaruddin Malik; Deris, Mustafa Mat

    File carving is an important, practical technique for data recovery in digital forensics investigation and is particularly useful when filesystem metadata is unavailable or damaged. The research on reassembly of JPEG files with RST markers, fragmented within the scan area have been done before. However, fragmentation within Define Huffman Table (DHT) segment is yet to be resolved. This paper analyzes the fragmentation within the DHT area and list out all the fragmentation possibilities. Two main contributions are made in this paper. Firstly, three fragmentation points within DHT area are listed. Secondly, few novel validators are proposed to detect these fragmentations. The result obtained from tests done on manually fragmented JPEG files, showed that all three fragmentation points within DHT are successfully detected using validators.

  10. Internet Point of Care Learning at a Community Hospital

    ERIC Educational Resources Information Center

    Sinusas, Keith

    2009-01-01

    Introduction: Internet point of care (PoC) learning is a relatively new method for obtaining continuing medical education credits. Few data are available to describe physician utilization of this CME activity. Methods: We describe the Internet point of care system we developed at a medium-sized community hospital and report on its first year of…

  11. Reliability of High-Temperature Fixed-Point Installations over 8 Years

    NASA Astrophysics Data System (ADS)

    Elliott, C. J.; Ford, T.; Ongrai, O.; Pearce, J. V.

    2017-12-01

    At NPL, high-temperature metal-carbon eutectic fixed points have been set up for thermocouple calibration purposes since 2006, for realising reference temperatures above the highest point specified in the International Temperature Scale of 1990 for contact thermometer calibrations. Additionally, cells of the same design have been provided by NPL to other national measurement institutes (NMIs) and calibration laboratories over this period, creating traceable and ISO 17025 accredited facilities around the world for calibrating noble metal thermocouples at 1324 {°}C (Co-C) and 1492 {°}C (Pd-C). This paper shows collections of thermocouple calibration results obtained during use of the high-temperature fixed-point cells at NPL and, as further examples, the use of cells installed at CCPI Europe (UK) and NIMT (Thailand). The lifetime of the cells can now be shown to be in excess of 7 years, whether used on a weekly or monthly basis, and whether used in an NMI or industrial calibration laboratory.

  12. Calibration of Viking imaging system pointing, image extraction, and optical navigation measure

    NASA Technical Reports Server (NTRS)

    Breckenridge, W. G.; Fowler, J. W.; Morgan, E. M.

    1977-01-01

    Pointing control and knowledge accuracy of Viking Orbiter science instruments is controlled by the scan platform. Calibration of the scan platform and the imaging system was accomplished through mathematical models. The calibration procedure and results obtained for the two Viking spacecraft are described. Included are both ground and in-flight scan platform calibrations, and the additional calibrations unique to optical navigation.

  13. RPBS: Rotational Projected Binary Structure for point cloud representation

    NASA Astrophysics Data System (ADS)

    Fang, Bin; Zhou, Zhiwei; Ma, Tao; Hu, Fangyu; Quan, Siwen; Ma, Jie

    2018-03-01

    In this paper, we proposed a novel three-dimension local surface descriptor named RPBS for point cloud representation. First, points cropped form the query point within a predefined radius is regard as a local surface patch. Then pose normalization is done to the local surface to equip our descriptor with the invariance to rotation transformation. To obtain more information about the cropped surface, multi-view representation is formed by successively rotating it along the coordinate axis. Further, orthogonal projections to the three coordinate plane are adopted to construct two-dimension distribution matrixes, and binarization is applied to each matrix by following the rule that whether the grid is occupied, if yes, set the grid one, otherwise zero. We calculate the binary maps from all the viewpoints and concatenate them together as the final descriptor. Comparative experiments for evaluating our proposed descriptor is conducted on the standard dataset named Bologna with several state-of-the-art 3D descriptors, and results show that our descriptor achieves the best performance on feature matching experiments.

  14. Investigations of a Combustor Using a 9-Point Swirl-Venturi Fuel Injector: Recent Experimental Results

    NASA Technical Reports Server (NTRS)

    Hicks, Yolanda R.; Heath, Christopher M.; Anderson, Robert C.; Tacina, Kathleen M.

    2012-01-01

    This paper explores recent results obtained during testing in an optically-accessible, JP8-fueled, flame tube combustor using baseline Lean Direct Injection (LDI) research hardware. The baseline LDI geometry has nine fuel/air mixers arranged in a 3 x 3 array. Results from this nine-element array include images of fuel and OH speciation via Planar Laser-Induced Fluorescence (PLIF), which describe fuel spray pattern and reaction zones. Preliminary combustion temperatures derived from Stokes/Anti-Stokes Spontaneous Raman Spectroscopy are also presented. Other results using chemiluminescence from major combustion radicals such as CH* and C2* serve to identify the primary reaction zone, while OH PLIF shows the extent of reaction further downstream. Air and fuel velocities and fuel drop size results are also reported.

  15. Probabilities and statistics for backscatter estimates obtained by a scatterometer with applications to new scatterometer design data

    NASA Technical Reports Server (NTRS)

    Pierson, Willard J., Jr.

    1989-01-01

    The values of the Normalized Radar Backscattering Cross Section (NRCS), sigma (o), obtained by a scatterometer are random variables whose variance is a known function of the expected value. The probability density function can be obtained from the normal distribution. Models for the expected value obtain it as a function of the properties of the waves on the ocean and the winds that generated the waves. Point estimates of the expected value were found from various statistics given the parameters that define the probability density function for each value. Random intervals were derived with a preassigned probability of containing that value. A statistical test to determine whether or not successive values of sigma (o) are truly independent was derived. The maximum likelihood estimates for wind speed and direction were found, given a model for backscatter as a function of the properties of the waves on the ocean. These estimates are biased as a result of the terms in the equation that involve natural logarithms, and calculations of the point estimates of the maximum likelihood values are used to show that the contributions of the logarithmic terms are negligible and that the terms can be omitted.

  16. Point-ahead limitation on reciprocity tracking. [in earth-space optical link

    NASA Technical Reports Server (NTRS)

    Shapiro, J. H.

    1975-01-01

    The average power received at a spacecraft from a reciprocity-tracking transmitter is shown to be the free-space diffraction-limited result times a gain-reduction factor that is due to the point-ahead requirement. For a constant-power transmitter, the gain-reduction factor is approximately equal to the appropriate spherical-wave mutual-coherence function. For a constant-average-power transmitter, an exact expression is obtained for the gain-reduction factor.

  17. NFIRE-to-TerraSAR-X laser communication results: satellite pointing, disturbances, and other attributes consistent with successful performance

    NASA Astrophysics Data System (ADS)

    Fields, Renny; Lunde, Carl; Wong, Robert; Wicker, Josef; Kozlowski, David; Jordan, John; Hansen, Brian; Muehlnikel, Gerd; Scheel, Wayne; Sterr, Uwe; Kahle, Ralph; Meyer, Rolf

    2009-05-01

    Starting in late 2007 and continuing through the present, NFIRE (Near-Field Infrared Experiment), a Missile Defense Agency (MDA) experimental satellite and TerraSAR-X, a German commercial SAR satellite have been conducting mutual crosslink experiments utilizing a secondary laser communication payload built by Tesat-Spacecom. The narrow laser beam-widths and high relative inter-spacecraft velocities for the two low-earth-orbiting satellites imply strict pointing control and dynamics aboard both vehicles. The satellites have achieved rapid communication acquisition times and maintained communication for hundreds of seconds before losing line of sight to the counter satellite due to earth blockage. Through post-mission analysis and other related telemetry we will show results for pointing accuracy, disturbance environments and pre-engagement prediction requirements that support successful and reliable operations.

  18. Application of Template Matching for Improving Classification of Urban Railroad Point Clouds

    PubMed Central

    Arastounia, Mostafa; Oude Elberink, Sander

    2016-01-01

    This study develops an integrated data-driven and model-driven approach (template matching) that clusters the urban railroad point clouds into three classes of rail track, contact cable, and catenary cable. The employed dataset covers 630 m of the Dutch urban railroad corridors in which there are four rail tracks, two contact cables, and two catenary cables. The dataset includes only geometrical information (three dimensional (3D) coordinates of the points) with no intensity data and no RGB data. The obtained results indicate that all objects of interest are successfully classified at the object level with no false positives and no false negatives. The results also show that an average 97.3% precision and an average 97.7% accuracy at the point cloud level are achieved. The high precision and high accuracy of the rail track classification (both greater than 96%) at the point cloud level stems from the great impact of the employed template matching method on excluding the false positives. The cables also achieve quite high average precision (96.8%) and accuracy (98.4%) due to their high sampling and isolated position in the railroad corridor. PMID:27973452

  19. Multiple scattered radiation emerging from Rayleigh and continental haze layers. I - Radiance, polarization, and neutral points

    NASA Technical Reports Server (NTRS)

    Kattawar, G. W.; Plass, G. N.; Hitzfelder, S. J.

    1976-01-01

    The matrix operator method was used to calculate the polarization of radiation scattered on layers of various optical thicknesses, with results compared for Rayleigh scattering and for scattering from a continental haze. In both cases, there are neutral points arising from the zeros of the polarization of single scattered photons at scattering angles of zero and 180 degrees. The angular position of these Rayleigh-like neutral points (RNP) in the sky shows appreciable variation with the optical thickness of the scattering layer for a Rayleigh phase matrix, but only a small variation for haze L phase matrix. Another type of neutral point exists for non-Rayleigh phase functions that is associated with the zeros of the polarization for single scattering which occurs between the end points of the curve. A comparison of radiances calculated from the complete theory of radiative transfer using Stokes vectors with those obtained from the scalar theory shows that differences of the order of 23% may be obtained for Rayleigh scattering, while the largest difference found for a haze L phase function was of the order of 0.1%.

  20. Can we approach the gas-liquid critical point using slab simulations of two coexisting phases?

    PubMed

    Goujon, Florent; Ghoufi, Aziz; Malfreyt, Patrice; Tildesley, Dominic J

    2016-09-28

    In this paper, we demonstrate that it is possible to approach the gas-liquid critical point of the Lennard-Jones fluid by performing simulations in a slab geometry using a cut-off potential. In the slab simulation geometry, it is essential to apply an accurate tail correction to the potential energy, applied during the course of the simulation, to study the properties of states close to the critical point. Using the Janeček slab-based method developed for two-phase Monte Carlo simulations [J. Janec̆ek, J. Chem. Phys. 131, 6264 (2006)], the coexisting densities and surface tension in the critical region are reported as a function of the cutoff distance in the intermolecular potential. The results obtained using slab simulations are compared with those obtained using grand canonical Monte Carlo simulations of isotropic systems and the finite-size scaling techniques. There is a good agreement between these two approaches. The two-phase simulations can be used in approaching the critical point for temperatures up to 0.97 T C ∗ (T ∗ = 1.26). The critical-point exponents describing the dependence of the density, surface tension, and interfacial thickness on the temperature are calculated near the critical point.

  1. Pedestrian Pathfinding in Urban Environments: Preliminary Results

    NASA Astrophysics Data System (ADS)

    López-Pazos, G.; Balado, J.; Díaz-Vilariño, L.; Arias, P.; Scaioni, M.

    2017-12-01

    With the rise of urban population, many initiatives are focused upon the smart city concept, in which mobility of citizens arises as one of the main components. Updated and detailed spatial information of outdoor environments is needed to accurate path planning for pedestrians, especially for people with reduced mobility, in which physical barriers should be considered. This work presents a methodology to use point clouds to direct path planning. The starting point is a classified point cloud in which ground elements have been previously classified as roads, sidewalks, crosswalks, curbs and stairs. The remaining points compose the obstacle class. The methodology starts by individualizing ground elements and simplifying them into representative points, which are used as nodes in the graph creation. The region of influence of obstacles is used to refine the graph. Edges of the graph are weighted according to distance between nodes and according to their accessibility for wheelchairs. As a result, we obtain a very accurate graph representing the as-built environment. The methodology has been tested in a couple of real case studies and Dijkstra algorithm was used to pathfinding. The resulting paths represent the optimal according to motor skills and safety.

  2. Antimicrobial usage in German acute care hospitals: results of the third national point prevalence survey and comparison with previous national point prevalence surveys.

    PubMed

    Aghdassi, Seven Johannes Sam; Gastmeier, Petra; Piening, Brar Christian; Behnke, Michael; Peña Diaz, Luis Alberto; Gropmann, Alexander; Rosenbusch, Marie-Luise; Kramer, Tobias Siegfried; Hansen, Sonja

    2018-04-01

    Previous point prevalence surveys (PPSs) revealed the potential for improving antimicrobial usage (AU) in German acute care hospitals. Data from the 2016 German national PPS on healthcare-associated infections and AU were used to evaluate efforts in antimicrobial stewardship (AMS). A national PPS in Germany was organized by the German National Reference Centre for Surveillance of Nosocomial Infections in 2016 as part of the European PPS initiated by the ECDC. The data were collected in May and June 2016. Results were compared with data from the PPS 2011. A total of 218 hospitals with 64 412 observed patients participated in the PPS 2016. The prevalence of patients with AU was 25.9% (95% CI 25.6%-26.3%). No significant increase or decrease in AU prevalence was revealed in the group of all participating hospitals. Prolonged surgical prophylaxis was found to be common (56.1% of all surgical prophylaxes on the prevalence day), but significantly less prevalent than in 2011 (P < 0.01). The most frequently administered antimicrobial groups were penicillins plus β-lactamase inhibitors (BLIs) (23.2%), second-generation cephalosporins (12.9%) and fluoroquinolones (11.3%). Significantly more penicillins plus BLIs and fewer second-generation cephalosporins and fluoroquinolones were used in 2016. Overall, an increase in the consumption of broad-spectrum antimicrobials was noted. For 68.7% of all administered antimicrobials, the indication was documented in the patient notes. The current data reaffirm the points of improvement that previous data identified and reveal that recent efforts in AMS in German hospitals require further intensification.

  3. The lambda point experiment in microgravity

    NASA Technical Reports Server (NTRS)

    Lipa, J. A.

    1988-01-01

    The motivation and potential for performing very high resolution measurements of the heat capacity singularity at the lambda point of helium in microgravity conditions was briefly discussed. It is clear that tests extending deep into the asymptotic region can be performed, where the theoretical predictions take on their simplest form. This advantageous situation should lead to a major improvement in the understanding of the range of applicability of current theoretical ideas in this field. The lambda transition holds out the prospect of giving the maximum advance of any system, and with the application of cryogenic techniques, the potential of this system can be realized. The technology for the initial experiments is already developed, and results could be obtained in 1990.

  4. Influence of conversion on the location of points and lines: The change of location entropy and the probability of a vector point inside the converted grid point

    NASA Astrophysics Data System (ADS)

    Chen, Nan

    2018-03-01

    Conversion of points or lines from vector to grid format, or vice versa, is the first operation required for most spatial analysis. Conversion, however, usually causes the location of points or lines to change, which influences the reliability of the results of spatial analysis or even results in analysis errors. The purpose of this paper is to evaluate the change of the location of points and lines during conversion using the concepts of probability and entropy. This paper shows that when a vector point is converted to a grid point, the vector point may be outside or inside the grid point. This paper deduces a formula for computing the probability that the vector point is inside the grid point. It was found that the probability increased with the side length of the grid and with the variances of the coordinates of the vector point. In addition, the location entropy of points and lines are defined in this paper. Formulae for computing the change of the location entropy during conversion are deduced. The probability mentioned above and the change of location entropy may be used to evaluate the location reliability of points and lines in Geographic Information Systems and may be used to choose an appropriate range of the side length of grids before conversion. The results of this study may help scientists and users to avoid mistakes caused by the change of location during conversion as well as in spatial decision and analysis.

  5. LIDAR Point Cloud Data Extraction and Establishment of 3D Modeling of Buildings

    NASA Astrophysics Data System (ADS)

    Zhang, Yujuan; Li, Xiuhai; Wang, Qiang; Liu, Jiang; Liang, Xin; Li, Dan; Ni, Chundi; Liu, Yan

    2018-01-01

    This paper takes the method of Shepard’s to deal with the original LIDAR point clouds data, and generate regular grid data DSM, filters the ground point cloud and non ground point cloud through double least square method, and obtains the rules of DSM. By using region growing method for the segmentation of DSM rules, the removal of non building point cloud, obtaining the building point cloud information. Uses the Canny operator to extract the image segmentation is needed after the edges of the building, uses Hough transform line detection to extract the edges of buildings rules of operation based on the smooth and uniform. At last, uses E3De3 software to establish the 3D model of buildings.

  6. Multi-point observations of large-amplitude electric fields during substorms obtained by THEMIS

    NASA Astrophysics Data System (ADS)

    Ogasawara, K.; Kasaba, Y.; Nishimura, Y.; Hori, T.; Takada, T.; Miyashita, Y.; Angelopoulos, V.; Bonnell, J. W.; McFadden, J. P.

    2009-12-01

    Large-amplitude electric fields over 100 mV/m have been observed around the equatorial magnetosphere. These electric fields may contribute to energy transport and particle acceleration in the magnetosphere [e.g., Wygant et al., 2000, 2002], and seem to be related to fast plasma flows with a size of a few Re [Nakamura et al., 2001]. In order to understand their macroscopic characteristics and the effects to magnetic activities, it is important to observe both fields and particles simultaneously at multiple locations within several Re. Five THEMIS probes can frequently provide such chances. In this paper, we show the several events with large-amplitude electric fields during substorms obtained by THEMIS. One of the events is found in 05:50-06:00 UT on 11 March 2008, when TH-D (Xsm=-10.7 Re, Ysm=4.8 Re) and TH-E (Xsm=-10.3 Re, Ysm=5.6 Re) observed intense electric fields. At 05:54 UT, THEMIS GBO-s clearly showed the auroral onset signature. The great intensification was near the SNKQ station, and this structure moved westward with the speed of ~6 km/s. It corresponds to ~200 km/s, as mapped to the TH-D/E location. The footprints of TH-A (Xsm=-6.8 Re, Ysm=-0.4 Re), D, and E were close to the site of the aurora. The location of TH-D was beside that of TH-E, and TH-A was located earthward and eastward from the former two. The enhanced electric fields observed by TH-D and E were associated with magnetic dipolarization and earthward high-speed plasma flow. They were also associated with the depletion of electron density estimated by the spacecraft potential. These features are consistent with the model of plasma bubbles [e.g., Pontius and Wolf, 1990]. The Y components of plasma flows were 200-300 km/s, roughly consistent with the westward auroral motion as mapped to the equatorial magnetosphere. Also, we found that Poynting flux of low frequency was efficient to illuminate the auroral emissions. This fact suggests that electromagnetic energy is transported to the

  7. Experimental Results Obtained with Air Liquide Cold Compression System: CERN LHC and SNS Projects

    NASA Astrophysics Data System (ADS)

    Delcayre, F.; Courty, J.-C.; Hamber, F.; Hilbert, B.; Monneret, E.; Toia, J.-L.

    2006-04-01

    Large scale collider facilities will make intensive use of superconducting magnets, operating below 2.0 K. This dictates high-capacity refrigeration systems operating below 2.0 K. These systems, making use of cryogenic centrifugal compressors in a series arrangement with room temperature screw compressors will be coupled to a refrigerator, providing a certain power at 4.5 K. A first Air Liquide Cold Compression System (CCS) unit was built and delivered to CERN in 2001. Installed at the beginning of 2002, it was commissioned and tested successfully during year 2002. A series of four sets of identical CCS were then tested in 2004. Another set of four cryogenic centrifugal compressors (CCC) has been delivered to Thomas Jefferson National Accelerator Facility (JLAB) for the Spallation Neutron Source (SNS) in 2002. These compressors were tested and commissioned from December 2004 to July 2005. The experimental results obtained with these systems will be presented and discussed: the characteristics of the CCC will be detailed. The principles of control for the CCC in series will be detailed.

  8. A travel time forecasting model based on change-point detection method

    NASA Astrophysics Data System (ADS)

    LI, Shupeng; GUANG, Xiaoping; QIAN, Yongsheng; ZENG, Junwei

    2017-06-01

    Travel time parameters obtained from road traffic sensors data play an important role in traffic management practice. A travel time forecasting model is proposed for urban road traffic sensors data based on the method of change-point detection in this paper. The first-order differential operation is used for preprocessing over the actual loop data; a change-point detection algorithm is designed to classify the sequence of large number of travel time data items into several patterns; then a travel time forecasting model is established based on autoregressive integrated moving average (ARIMA) model. By computer simulation, different control parameters are chosen for adaptive change point search for travel time series, which is divided into several sections of similar state.Then linear weight function is used to fit travel time sequence and to forecast travel time. The results show that the model has high accuracy in travel time forecasting.

  9. Multiple scattered radiation emerging from continental haze layers. 1: Radiance, polarization, and neutral points

    NASA Technical Reports Server (NTRS)

    Kattawar, G. W.; Plass, G. N.; Hitzfelder, S. J.

    1975-01-01

    The complete radiation field is calculated for scattering layers of various optical thicknesses. Results obtained for Rayleigh and haze scattering are compared. Calculated radiances show differences as large as 23% compared to the approximate scalar theory of radiative transfer, while the same differences are approximately 0.1% for a continental haze phase function. The polarization of reflected and transmitted radiation is given for various optical thicknesses, solar zenith angles, and surface albedos. Two types of neutral points occur for aerosol phase functions. Rayleigh-like neutral points arise from zero polarization that occurs at scattering angles of 0 deg and 180 deg. For Rayleigh phase functions, the position of these points varies with the optical thickness of the scattering layer. Non-Rayleigh neutral points are associated with the zeros of polarization which occur between the end points of the single scattering curve, and are found over a wide range of azimuthal angles.

  10. Distribution majorization of corner points by reinforcement learning for moving object detection

    NASA Astrophysics Data System (ADS)

    Wu, Hao; Yu, Hao; Zhou, Dongxiang; Cheng, Yongqiang

    2018-04-01

    Corner points play an important role in moving object detection, especially in the case of free-moving camera. Corner points provide more accurate information than other pixels and reduce the computation which is unnecessary. Previous works only use intensity information to locate the corner points, however, the information that former and the last frames provided also can be used. We utilize the information to focus on more valuable area and ignore the invaluable area. The proposed algorithm is based on reinforcement learning, which regards the detection of corner points as a Markov process. In the Markov model, the video to be detected is regarded as environment, the selections of blocks for one corner point are regarded as actions and the performance of detection is regarded as state. Corner points are assigned to be the blocks which are seperated from original whole image. Experimentally, we select a conventional method which uses marching and Random Sample Consensus algorithm to obtain objects as the main framework and utilize our algorithm to improve the result. The comparison between the conventional method and the same one with our algorithm show that our algorithm reduce 70% of the false detection.

  11. A step towards standardization: A method for end-point titer determination by fluorescence index of an automated microscope. End-point titer determination by fluorescence index.

    PubMed

    Carbone, Teresa; Gilio, Michele; Padula, Maria Carmela; Tramontano, Giuseppina; D'Angelo, Salvatore; Pafundi, Vito

    2018-05-01

    Indirect Immunofluorescence (IIF) is widely considered the Gold Standard for Antinuclear Antibody (ANA) screening. However, the high inter-reader variability remains the major disadvantage associated with ANA testing and the main reason for the increasing demand of the computer-aided immunofluorescence microscope. Previous studies proposed the quantification of the fluorescence intensity as an alternative for the classical end-point titer evaluation. However, the different distribution of bright/dark light linked to the nature of the self-antigen and its location in the cells result in different mean fluorescence intensities. The aim of the present study was to correlate Fluorescence Index (F.I.) with end-point titers for each well-defined ANA pattern. Routine serum samples were screened for ANA testing on HEp-2000 cells using Immuno Concepts Image Navigator System, and positive samples were serially diluted to assign the end-point titer. A comparison between F.I. and end-point titers related to 10 different staining patterns was made. According to our analysis, good technical performance of F.I. (97% sensitivity and 94% specificity) was found. A significant correlation between quantitative reading of F.I. and end-point titer groups was observed using Spearman's test and regression analysis. A conversion scale of F.I. in end-point titers for each recognized ANA-pattern was obtained. The Image Navigator offers the opportunity to improve worldwide harmonization of ANA test results. In particular, digital F.I. allows quantifying ANA titers by using just one sample dilution. It could represent a valuable support for the routine laboratory and an effective tool to reduce inter- and intra-laboratory variability. Copyright © 2018. Published by Elsevier B.V.

  12. Hole-ness of point clouds

    NASA Astrophysics Data System (ADS)

    Gronz, Oliver; Seeger, Manuel; Klaes, Björn; Casper, Markus C.; Ries, Johannes B.

    2015-04-01

    Accurate and dense 3D models of soil surfaces can be used in various ways: They can be used as initial shapes for erosion models. They can be used as benchmark shapes for erosion model outputs. They can be used to derive metrics, such as random roughness... One easy and low-cost method to produce these models is structure from motion (SfM). Using this method, two questions arise: Does the soil moisture, which changes the colour, albedo and reflectivity of the soil, influence the model quality? How can the model quality be evaluated? To answer these questions, a suitable data set has been produced: soil has been placed on a tray and areas with different roughness structures have been formed. For different moisture states - dry, medium, saturated - and two different lighting conditions - direct and indirect - sets of high-resolution images at the same camera positions have been taken. From the six image sets, 3D point clouds have been produced using VisualSfM. The visual inspection of the 3D models showed that all models have different areas, where holes of different sizes occur. But it is obviously a subjective task to determine the model's quality by visual inspection. One typical approach to evaluate model quality objectively is to estimate the point density on a regular, two-dimensional grid: the number of 3D points in each grid cell projected on a plane is calculated. This works well for surfaces that do not show vertical structures. Along vertical structures, many points will be projected on the same grid cell and thus the point density rather depends on the shape of the surface but less on the quality of the model. Another approach has been applied by using the points resulting from Poisson Surface Reconstructions. One of this algorithm's properties is the filling of holes: new points are interpolated inside the holes. Using the original 3D point cloud and the interpolated Poisson point set, two analyses have been performed: For all Poisson points, the

  13. Clinicians' interpretations of point of care urine culture versus laboratory culture results: analysis from the four-country POETIC trial of diagnosis of uncomplicated urinary tract infection in primary care.

    PubMed

    Hullegie, Saskia; Wootton, Mandy; Verheij, Theo J M; Thomas-Jones, Emma; Bates, Janine; Hood, Kerenza; Gal, Micaela; Francis, Nick A; Little, Paul; Moore, Michael; Llor, Carl; Pickles, Timothy; Gillespie, David; Kirby, Nigel; Brugman, Curt; Butler, Christopher C

    2017-08-01

    Urine culture at the point of care minimises delay between obtaining the sample and agar inoculation in a microbiology laboratory, and quantification and sensitivity results can be available more rapidly in primary care. To identify the degree to which clinicians' interpretations of a point-of-care-test (POCT) urine culture (Flexicult™ SSI-Urinary Kit) agrees with laboratory culture in women presenting to primary care with symptoms of uncomplicated urinary tract infections (UTI). Primary care clinicians used the Flexicult™-POCT, recorded their findings and took a photograph of the result, which was interpreted by microbiology laboratory technicians. Urine samples were additionally processed in routine care laboratories. Cross tabulations were used to identify important differences in organism identification, quantification and antibiotic susceptibility between these three sources of data. The influence of various laboratory definitions for UTI on culture were assessed. Primary care clinicians identified 202/289 urine samples (69.9%) as positive for UTI using the Flexicult™-POCT, whereas laboratory culture identified 94-190 (32.5-65.7%) as positive, depending on definition thresholds. 82.9% of samples identified positive for E. coli on laboratory culture were also considered positive for E. coli using the Flexicult™ -POCT, and susceptibilities were reasonably concordant. There were major discrepancies between laboratory staff interpretation of Flexicult™ photographs, clinicians' interpretation of the Flexicult™ test, and laboratory culture results. Flexicult™-POCT overestimated the positivity rate of urine samples for UTI when laboratory culture was used as the reference standard. However, it is unclear whether point-of-care or laboratory based urine culture provides the most valid diagnostic information. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Inertial Pointing and Positioning System

    NASA Technical Reports Server (NTRS)

    Yee, Robert (Inventor); Robbins, Fred (Inventor)

    1998-01-01

    An inertial pointing and control system and method for pointing to a designated target with known coordinates from a platform to provide accurate position, steering, and command information. The system continuously receives GPS signals and corrects Inertial Navigation System (INS) dead reckoning or drift errors. An INS is mounted directly on a pointing instrument rather than in a remote location on the platform for-monitoring the terrestrial position and instrument attitude. and for pointing the instrument at designated celestial targets or ground based landmarks. As a result. the pointing instrument and die INS move independently in inertial space from the platform since the INS is decoupled from the platform. Another important characteristic of the present system is that selected INS measurements are combined with predefined coordinate transformation equations and control logic algorithms under computer control in order to generate inertial pointing commands to the pointing instrument. More specifically. the computer calculates the desired instrument angles (Phi, Theta. Psi). which are then compared to the Euler angles measured by the instrument- mounted INS. and forms the pointing command error angles as a result of the compared difference.

  15. Impact of magnetic isolation on pointing system performance in the presence of structural flexibility

    NASA Technical Reports Server (NTRS)

    Seller, J.

    1985-01-01

    The inertial pointing stability of a gimbal pointing system (AGS) was compared with a magnetic pointing/gimbal followup system (ASPS), under certain conditions of system structural flexibility and disturbance inputs from the gimbal support structure. Separate 3 degree-of-freedom (3DOF) linear models based on NASTRAN modal flexibility data for the gimbal and support structures were generated for the ASPS configurations. Using the models inertial pointing control loops providing 6dB of gain margin and 45 deg of phase margin were defined for each configuration. The pointing loop bandwidth obtained for the ASPS is more than twice the level achieved for the AGS configuration. The AGS limit is attributed to the gimbal and support structure flexibility. As a result of the higher ASPS pointing loop bandwidth and the disturbance rejection provided by the magnetic isolation ASPS pointing performane is significantly better than that of the AGS system. The low frequency peak of the ASPS transfer function from base disturbance to payload angular motion is almost 60dB lower than AGS low frequency peak.

  16. Importance of Adopting BMI Classifications Using Public Health Action Points to Delineate Obstetric Risk Factors Resulting in Worsening Obstetric Outcomes Among Asian Population.

    PubMed

    Ganeshan, Muniswaran; Bujang, Mohamad Adam; Soelar, Shahrul Aiman; Karalasingam, Shamala Devi; Suharjono, Harris; Jeganathan, Ravichandran

    2018-06-01

    The aim of this study is to compare obstetric outcomes between overweight and class 1 obesity among pregnant women in their first pregnancy based on WHO's BMI cut-offs and the potential public health action points identified by WHO expert consultations specific for high-risk population such as Asians. This is a retrospective cohort review of data obtained from the Malaysian National Obstetrics and Gynaecology Registry between the year 2010 and year 2012. All women in their first pregnancy with a booking BMI in their first trimester were included in this study. The association between BMI classifications as defined by the WHO cut-offs and the potential public health action points identified by WHO expert consultations towards adverse obstetric outcomes was compared. A total of 88,837 pregnant women were included in this study. We noted that the risk of adverse obstetric outcomes was significantly higher using the public health action points identified by WHO expert consultations even among the overweight group as the risk of stillbirths was (OR 1.2; 95% CI 1.0,1.4), shoulder dystocia (OR 1.9; 95% CI 1.2,2.9), foetal macrosomia (OR 1.8; 95% CI 1.6,2.0), caesarean section (OR 1.9; 95% CI 1.8,2.0) and assisted conception (OR 1.9; 95% CI 1.6,2.1). A specifically lower BMI references based on the potential public health action points for BMI classifications were a more sensitive predictor of adverse obstetric outcomes, and we recommend the use of these references in pregnancy especially among Asian population.

  17. Triple point determinations of monomethylhydrazine and nitrogen tetroxide, 2.2 percent by weight nitric oxide

    NASA Technical Reports Server (NTRS)

    Smith, Irwin D.; Dhooge, Patrick M.

    1977-01-01

    A series of tests was performed to ascertain the triple points of monomethylhydrazine and nitrogen tetroxide. A laboratory method indicated a triple point for monomethylhydrazine, but tests in a large vacuum chamber indicated that a triple point does not occur in spacelike conditions because the mono-methylhydrazine tends to supercool. Instead, an effective freezing point (with agitation) was obtained. New experimental values for liquid monomethylhydrazine vapor pressure were determined for temperatures from 275.2 to 207.6 K. The values were used to derive vapor pressure equations. Tentative values were obtained for the effective freezing point of nitrogen tetroxide spacelike conditions.

  18. Reference point detection for camera-based fingerprint image based on wavelet transformation.

    PubMed

    Khalil, Mohammed S

    2015-04-30

    Fingerprint recognition systems essentially require core-point detection prior to fingerprint matching. The core-point is used as a reference point to align the fingerprint with a template database. When processing a larger fingerprint database, it is necessary to consider the core-point during feature extraction. Numerous core-point detection methods are available and have been reported in the literature. However, these methods are generally applied to scanner-based images. Hence, this paper attempts to explore the feasibility of applying a core-point detection method to a fingerprint image obtained using a camera phone. The proposed method utilizes a discrete wavelet transform to extract the ridge information from a color image. The performance of proposed method is evaluated in terms of accuracy and consistency. These two indicators are calculated automatically by comparing the method's output with the defined core points. The proposed method is tested on two data sets, controlled and uncontrolled environment, collected from 13 different subjects. In the controlled environment, the proposed method achieved a detection rate 82.98%. In uncontrolled environment, the proposed method yield a detection rate of 78.21%. The proposed method yields promising results in a collected-image database. Moreover, the proposed method outperformed compare to existing method.

  19. Fast grasping of unknown objects using cylinder searching on a single point cloud

    NASA Astrophysics Data System (ADS)

    Lei, Qujiang; Wisse, Martijn

    2017-03-01

    Grasping of unknown objects with neither appearance data nor object models given in advance is very important for robots that work in an unfamiliar environment. The goal of this paper is to quickly synthesize an executable grasp for one unknown object by using cylinder searching on a single point cloud. Specifically, a 3D camera is first used to obtain a partial point cloud of the target unknown object. An original method is then employed to do post treatment on the partial point cloud to minimize the uncertainty which may lead to grasp failure. In order to accelerate the grasp searching, surface normal of the target object is then used to constrain the synthetization of the cylinder grasp candidates. Operability analysis is then used to select out all executable grasp candidates followed by force balance optimization to choose the most reliable grasp as the final grasp execution. In order to verify the effectiveness of our algorithm, Simulations on a Universal Robot arm UR5 and an under-actuated Lacquey Fetch gripper are used to examine the performance of this algorithm, and successful results are obtained.

  20. Influencing Factors of the Initiation Point in the Parachute-Bomb Dynamic Detonation System

    NASA Astrophysics Data System (ADS)

    Qizhong, Li; Ye, Wang; Zhongqi, Wang; Chunhua, Bai

    2017-12-01

    The parachute system has been widely applied in modern armament design, especially for the fuel-air explosives. Because detonation of fuel-air explosives occurs during flight, it is necessary to investigate the influences of the initiation point to ensure successful dynamic detonation. In fact, the initiating position exist the falling area in the fuels, due to the error of influencing factors. In this paper, the major influencing factors of initiation point were explored with airdrop and the regularity between initiation point area and factors were obtained. Based on the regularity, the volume equation of initiation point area was established to predict the range of initiation point in the fuel. The analysis results showed that the initiation point appeared area, scattered on account of the error of attitude angle, secondary initiation charge velocity, and delay time. The attitude angle was the major influencing factors on a horizontal axis. On the contrary, secondary initiation charge velocity and delay time were the major influencing factors on a horizontal axis. Overall, the geometries of initiation point area were sector coupled with the errors of the attitude angle, secondary initiation charge velocity, and delay time.

  1. Application of the nudged elastic band method to the point-to-point radio wave ray tracing in IRI modeled ionosphere

    NASA Astrophysics Data System (ADS)

    Nosikov, I. A.; Klimenko, M. V.; Bessarab, P. F.; Zhbankov, G. A.

    2017-07-01

    Point-to-point ray tracing is an important problem in many fields of science. While direct variational methods where some trajectory is transformed to an optimal one are routinely used in calculations of pathways of seismic waves, chemical reactions, diffusion processes, etc., this approach is not widely known in ionospheric point-to-point ray tracing. We apply the Nudged Elastic Band (NEB) method to a radio wave propagation problem. In the NEB method, a chain of points which gives a discrete representation of the radio wave ray is adjusted iteratively to an optimal configuration satisfying the Fermat's principle, while the endpoints of the trajectory are kept fixed according to the boundary conditions. Transverse displacements define the radio ray trajectory, while springs between the points control their distribution along the ray. The method is applied to a study of point-to-point ionospheric ray tracing, where the propagation medium is obtained with the International Reference Ionosphere model taking into account traveling ionospheric disturbances. A 2-dimensional representation of the optical path functional is developed and used to gain insight into the fundamental difference between high and low rays. We conclude that high and low rays are minima and saddle points of the optical path functional, respectively.

  2. The effect of different control point sampling sequences on convergence of VMAT inverse planning

    NASA Astrophysics Data System (ADS)

    Pardo Montero, Juan; Fenwick, John D.

    2011-04-01

    A key component of some volumetric-modulated arc therapy (VMAT) optimization algorithms is the progressive addition of control points to the optimization. This idea was introduced in Otto's seminal VMAT paper, in which a coarse sampling of control points was used at the beginning of the optimization and new control points were progressively added one at a time. A different form of the methodology is also present in the RapidArc optimizer, which adds new control points in groups called 'multiresolution levels', each doubling the number of control points in the optimization. This progressive sampling accelerates convergence, improving the results obtained, and has similarities with the ordered subset algorithm used to accelerate iterative image reconstruction. In this work we have used a VMAT optimizer developed in-house to study the performance of optimization algorithms which use different control point sampling sequences, most of which fall into three different classes: doubling sequences, which add new control points in groups such that the number of control points in the optimization is (roughly) doubled; Otto-like progressive sampling which adds one control point at a time, and equi-length sequences which contain several multiresolution levels each with the same number of control points. Results are presented in this study for two clinical geometries, prostate and head-and-neck treatments. A dependence of the quality of the final solution on the number of starting control points has been observed, in agreement with previous works. We have found that some sequences, especially E20 and E30 (equi-length sequences with 20 and 30 multiresolution levels, respectively), generate better results than a 5 multiresolution level RapidArc-like sequence. The final value of the cost function is reduced up to 20%, such reductions leading to small improvements in dosimetric parameters characterizing the treatments—slightly more homogeneous target doses and better sparing of

  3. Csf Based Non-Ground Points Extraction from LIDAR Data

    NASA Astrophysics Data System (ADS)

    Shen, A.; Zhang, W.; Shi, H.

    2017-09-01

    Region growing is a classical method of point cloud segmentation. Based on the idea of collecting the pixels with similar properties to form regions, region growing is widely used in many fields such as medicine, forestry and remote sensing. In this algorithm, there are two core problems. One is the selection of seed points, the other is the setting of the growth constraints, in which the selection of the seed points is the foundation. In this paper, we propose a CSF (Cloth Simulation Filtering) based method to extract the non-ground seed points effectively. The experiments have shown that this method can obtain a group of seed spots compared with the traditional methods. It is a new attempt to extract seed points

  4. Hierarchical Higher Order Crf for the Classification of Airborne LIDAR Point Clouds in Urban Areas

    NASA Astrophysics Data System (ADS)

    Niemeyer, J.; Rottensteiner, F.; Soergel, U.; Heipke, C.

    2016-06-01

    We propose a novel hierarchical approach for the classification of airborne 3D lidar points. Spatial and semantic context is incorporated via a two-layer Conditional Random Field (CRF). The first layer operates on a point level and utilises higher order cliques. Segments are generated from the labelling obtained in this way. They are the entities of the second layer, which incorporates larger scale context. The classification result of the segments is introduced as an energy term for the next iteration of the point-based layer. This framework iterates and mutually propagates context to improve the classification results. Potentially wrong decisions can be revised at later stages. The output is a labelled point cloud as well as segments roughly corresponding to object instances. Moreover, we present two new contextual features for the segment classification: the distance and the orientation of a segment with respect to the closest road. It is shown that the classification benefits from these features. In our experiments the hierarchical framework improve the overall accuracies by 2.3% on a point-based level and by 3.0% on a segment-based level, respectively, compared to a purely point-based classification.

  5. Quantitative evaluation for small surface damage based on iterative difference and triangulation of 3D point cloud

    NASA Astrophysics Data System (ADS)

    Zhang, Yuyan; Guo, Quanli; Wang, Zhenchun; Yang, Degong

    2018-03-01

    This paper proposes a non-contact, non-destructive evaluation method for the surface damage of high-speed sliding electrical contact rails. The proposed method establishes a model of damage identification and calculation. A laser scanning system is built to obtain the 3D point cloud data of the rail surface. In order to extract the damage region of the rail surface, the 3D point cloud data are processed using iterative difference, nearest neighbours search and a data registration algorithm. The curvature of the point cloud data in the damage region is mapped to RGB color information, which can directly reflect the change trend of the curvature of the point cloud data in the damage region. The extracted damage region is divided into three prism elements by a method of triangulation. The volume and mass of a single element are calculated by the method of geometric segmentation. Finally, the total volume and mass of the damage region are obtained by the principle of superposition. The proposed method is applied to several typical injuries and the results are discussed. The experimental results show that the algorithm can identify damage shapes and calculate damage mass with milligram precision, which are useful for evaluating the damage in a further research stage.

  6. ICESat Laser Altimeter Pointing, Ranging and Timing Calibration from Integrated Residual Analysis: A Summary of Early Mission Results

    NASA Technical Reports Server (NTRS)

    Lutchke, Scott B.; Rowlands, David D.; Harding, David J.; Bufton, Jack L.; Carabajal, Claudia C.; Williams, Teresa A.

    2003-01-01

    On January 12, 2003 the Ice, Cloud and land Elevation Satellite (ICESat) was successfUlly placed into orbit. The ICESat mission carries the Geoscience Laser Altimeter System (GLAS), which consists of three near-infrared lasers that operate at 40 short pulses per second. The instrument has collected precise elevation measurements of the ice sheets, sea ice roughness and thickness, ocean and land surface elevations and surface reflectivity. The accurate geolocation of GLAS's surface returns, the spots from which the laser energy reflects on the Earth's surface, is a critical issue in the scientific application of these data Pointing, ranging, timing and orbit errors must be compensated to accurately geolocate the laser altimeter surface returns. Towards this end, the laser range observations can be fully exploited in an integrated residual analysis to accurately calibrate these geolocation/instrument parameters. Early mission ICESat data have been simultaneously processed as direct altimetry from ocean sweeps along with dynamic crossovers resulting in a preliminary calibration of laser pointing, ranging and timing. The calibration methodology and early mission analysis results are summarized in this paper along with future calibration activities

  7. 3D Solar Null Point Reconnection MHD Simulations

    NASA Astrophysics Data System (ADS)

    Baumann, G.; Galsgaard, K.; Nordlund, Å.

    2013-06-01

    Numerical MHD simulations of 3D reconnection events in the solar corona have improved enormously over the last few years, not only in resolution, but also in their complexity, enabling more and more realistic modeling. Various ways to obtain the initial magnetic field, different forms of solar atmospheric models as well as diverse driving speeds and patterns have been employed. This study considers differences between simulations with stratified and non-stratified solar atmospheres, addresses the influence of the driving speed on the plasma flow and energetics, and provides quantitative formulas for mapping electric fields and dissipation levels obtained in numerical simulations to the corresponding solar quantities. The simulations start out from a potential magnetic field containing a null-point, obtained from a Solar and Heliospheric Observatory (SOHO) Michelson Doppler Imager (MDI) magnetogram magnetogram extrapolation approximately 8 hours before a C-class flare was observed. The magnetic field is stressed with a boundary motion pattern similar to - although simpler than - horizontal motions observed by SOHO during the period preceding the flare. The general behavior is nearly independent of the driving speed, and is also very similar in stratified and non-stratified models, provided only that the boundary motions are slow enough. The boundary motions cause a build-up of current sheets, mainly in the fan-plane of the magnetic null-point, but do not result in a flare-like energy release. The additional free energy required for the flare could have been partly present in non-potential form at the initial state, with subsequent additions from magnetic flux emergence or from components of the boundary motion that were not represented by the idealized driving pattern.

  8. Mathematical inference in one point microrheology

    NASA Astrophysics Data System (ADS)

    Hohenegger, Christel; McKinley, Scott

    2016-11-01

    Pioneered by the work of Mason and Weitz, one point passive microrheology has been successfully applied to obtaining estimates of the loss and storage modulus of viscoelastic fluids when the mean-square displacement obeys a local power law. Using numerical simulations of a fluctuating viscoelastic fluid model, we study the problem of recovering the mechanical parameters of the fluid's memory kernel using statistical inference like mean-square displacements and increment auto-correlation functions. Seeking a better understanding of the influence of the assumptions made in the inversion process, we mathematically quantify the uncertainty in traditional one point microrheology for simulated data and demonstrate that a large family of memory kernels yields the same statistical signature. We consider both simulated data obtained from a full viscoelastic fluid simulation of the unsteady Stokes equations with fluctuations and from a Generalized Langevin Equation of the particle's motion described by the same memory kernel. From the theory of inverse problems, we propose an alternative method that can be used to recover information about the loss and storage modulus and discuss its limitations and uncertainties. NSF-DMS 1412998.

  9. Photoluminescence as a tool for characterizing point defects in semiconductors

    NASA Astrophysics Data System (ADS)

    Reshchikov, Michael

    2012-02-01

    Photoluminescence is one of the most powerful tools used to study optically-active point defects in semiconductors, especially in wide-bandgap materials. Gallium nitride (GaN) and zinc oxide (ZnO) have attracted considerable attention in the last two decades due to their prospects in optoelectronics applications, including blue and ultraviolet light-emitting devices. However, in spite of many years of extensive studies and a great number of publications on photoluminescence from GaN and ZnO, only a few defect-related luminescence bands are reliably identified. Among them are the Zn-related blue band in GaN, Cu-related green band and Li-related orange band in ZnO. Numerous suggestions for the identification of other luminescence bands, such as the yellow band in GaN, or green and yellow bands in ZnO, do not stand up under scrutiny. In these conditions, it is important to classify the defect-related luminescence bands and find their unique characteristics. In this presentation, we will review the origin of the major luminescence bands in GaN and ZnO. Through simulations of the temperature and excitation intensity dependences of photoluminescence and by employing phenomenological models we are able to obtain important characteristics of point defects such as carrier capture cross-sections for defects, concentrations of defects, and their charge states. These models are also used to find the absolute internal quantum efficiency of photoluminescence and obtain information about nonradiative defects. Results from photoluminescence measurements will be compared with results of the first-principle calculations, as well as with the experimental data obtained by other techniques such as positron annihilation spectroscopy, deep-level transient spectroscopy, and secondary ion mass spectrometry.

  10. Sampling saddle points on a free energy surface

    NASA Astrophysics Data System (ADS)

    Samanta, Amit; Chen, Ming; Yu, Tang-Qing; Tuckerman, Mark; E, Weinan

    2014-04-01

    Many problems in biology, chemistry, and materials science require knowledge of saddle points on free energy surfaces. These saddle points act as transition states and are the bottlenecks for transitions of the system between different metastable states. For simple systems in which the free energy depends on a few variables, the free energy surface can be precomputed, and saddle points can then be found using existing techniques. For complex systems, where the free energy depends on many degrees of freedom, this is not feasible. In this paper, we develop an algorithm for finding the saddle points on a high-dimensional free energy surface "on-the-fly" without requiring a priori knowledge the free energy function itself. This is done by using the general strategy of the heterogeneous multi-scale method by applying a macro-scale solver, here the gentlest ascent dynamics algorithm, with the needed force and Hessian values computed on-the-fly using a micro-scale model such as molecular dynamics. The algorithm is capable of dealing with problems involving many coarse-grained variables. The utility of the algorithm is illustrated by studying the saddle points associated with (a) the isomerization transition of the alanine dipeptide using two coarse-grained variables, specifically the Ramachandran dihedral angles, and (b) the beta-hairpin structure of the alanine decamer using 20 coarse-grained variables, specifically the full set of Ramachandran angle pairs associated with each residue. For the alanine decamer, we obtain a detailed network showing the connectivity of the minima obtained and the saddle-point structures that connect them, which provides a way to visualize the gross features of the high-dimensional surface.

  11. Evolution families of conformal mappings with fixed points and the Löwner-Kufarev equation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Goryainov, V V

    2015-01-31

    The paper is concerned with evolution families of conformal mappings of the unit disc to itself that fix an interior point and a boundary point. Conditions are obtained for the evolution families to be differentiable, and an existence and uniqueness theorem for an evolution equation is proved. A convergence theorem is established which describes the topology of locally uniform convergence of evolution families in terms of infinitesimal generating functions. The main result in this paper is the embedding theorem which shows that any conformal mapping of the unit disc to itself with two fixed points can be embedded into a differentiable evolution familymore » of such mappings. This result extends the range of the parametric method in the theory of univalent functions. In this way the problem of the mutual change of the derivative at an interior point and the angular derivative at a fixed point on the boundary is solved for a class of mappings of the unit disc to itself. In particular, the rotation theorem is established for this class of mappings. Bibliography: 27 titles.« less

  12. Application of closed-form solutions to a mesh point field in silicon solar cells

    NASA Technical Reports Server (NTRS)

    Lamorte, M. F.

    1985-01-01

    A computer simulation method is discussed that provides for equivalent simulation accuracy, but that exhibits significantly lower CPU running time per bias point compared to other techniques. This new method is applied to a mesh point field as is customary in numerical integration (NI) techniques. The assumption of a linear approximation for the dependent variable, which is typically used in the finite difference and finite element NI methods, is not required. Instead, the set of device transport equations is applied to, and the closed-form solutions obtained for, each mesh point. The mesh point field is generated so that the coefficients in the set of transport equations exhibit small changes between adjacent mesh points. Application of this method to high-efficiency silicon solar cells is described; and the method by which Auger recombination, ambipolar considerations, built-in and induced electric fields, bandgap narrowing, carrier confinement, and carrier diffusivities are treated. Bandgap narrowing has been investigated using Fermi-Dirac statistics, and these results show that bandgap narrowing is more pronounced and that it is temperature-dependent in contrast to the results based on Boltzmann statistics.

  13. Comparison of contact conditions obtained by direct simulation with statistical analysis for normally distributed isotropic surfaces

    NASA Astrophysics Data System (ADS)

    Uchidate, M.

    2018-09-01

    In this study, with the aim of establishing a systematic knowledge on the impact of summit extraction methods and stochastic model selection in rough contact analysis, the contact area ratio (A r /A a ) obtained by statistical contact models with different summit extraction methods was compared with a direct simulation using the boundary element method (BEM). Fifty areal topography datasets with different autocorrelation functions in terms of the power index and correlation length were used for investigation. The non-causal 2D auto-regressive model which can generate datasets with specified parameters was employed in this research. Three summit extraction methods, Nayak’s theory, 8-point analysis and watershed segmentation, were examined. With regard to the stochastic model, Bhushan’s model and BGT (Bush-Gibson-Thomas) model were applied. The values of A r /A a from the stochastic models tended to be smaller than BEM. The discrepancy between the Bhushan’s model with the 8-point analysis and BEM was slightly smaller than Nayak’s theory. The results with the watershed segmentation was similar to those with the 8-point analysis. The impact of the Wolf pruning on the discrepancy between the stochastic analysis and BEM was not very clear. In case of the BGT model which employs surface gradients, good quantitative agreement against BEM was obtained when the Nayak’s bandwidth parameter was large.

  14. Fractional charge and inter-Landau-level states at points of singular curvature.

    PubMed

    Biswas, Rudro R; Son, Dam Thanh

    2016-08-02

    The quest for universal properties of topological phases is fundamentally important because these signatures are robust to variations in system-specific details. Aspects of the response of quantum Hall states to smooth spatial curvature are well-studied, but challenging to observe experimentally. Here we go beyond this prevailing paradigm and obtain general results for the response of quantum Hall states to points of singular curvature in real space; such points may be readily experimentally actualized. We find, using continuum analytical methods, that the point of curvature binds an excess fractional charge and sequences of quantum states split away, energetically, from the degenerate bulk Landau levels. Importantly, these inter-Landau-level states are bound to the topological singularity and have energies that are universal functions of bulk parameters and the curvature. Our exact diagonalization of lattice tight-binding models on closed manifolds demonstrates that these results continue to hold even when lattice effects are significant. An important technological implication of these results is that these inter-Landau-level states, being both energetically and spatially isolated quantum states, are promising candidates for constructing qubits for quantum computation.

  15. Study into Point Cloud Geometric Rigidity and Accuracy of TLS-Based Identification of Geometric Bodies

    NASA Astrophysics Data System (ADS)

    Klapa, Przemyslaw; Mitka, Bartosz; Zygmunt, Mariusz

    2017-12-01

    Capability of obtaining a multimillion point cloud in a very short time has made the Terrestrial Laser Scanning (TLS) a widely used tool in many fields of science and technology. The TLS accuracy matches traditional devices used in land surveying (tacheometry, GNSS - RTK), but like any measurement it is burdened with error which affects the precise identification of objects based on their image in the form of a point cloud. The point’s coordinates are determined indirectly by means of measuring the angles and calculating the time of travel of the electromagnetic wave. Each such component has a measurement error which is translated into the final result. The XYZ coordinates of a measuring point are determined with some uncertainty and the very accuracy of determining these coordinates is reduced as the distance to the instrument increases. The paper presents the results of examination of geometrical stability of a point cloud obtained by means terrestrial laser scanner and accuracy evaluation of solids determined using the cloud. Leica P40 scanner and two different settings of measuring points were used in the tests. The first concept involved placing a few balls in the field and then scanning them from various sides at similar distances. The second part of measurement involved placing balls and scanning them a few times from one side but at varying distances from the instrument to the object. Each measurement encompassed a scan of the object with automatic determination of its position and geometry. The desk studies involved a semiautomatic fitting of solids and measurement of their geometrical elements, and comparison of parameters that determine their geometry and location in space. The differences of measures of geometrical elements of balls and translations vectors of the solids centres indicate the geometrical changes of the point cloud depending on the scanning distance and parameters. The results indicate the changes in the geometry of scanned objects

  16. Results of the Mariner 6 and 7 Mars occultation experiments

    NASA Technical Reports Server (NTRS)

    Hogan, J. S.; Stewart, R. W.; Rasool, S. I.; Russell, L. H.

    1972-01-01

    Final profiles of temperature, pressure, and electron density on Mars were obtained for the Mariner 6 and 7 entry and exit cases, and results are presented for both the lower atmosphere and ionosphere. The results of an analysis of the systematic and formal errors introduced at each stage of the data-reduction process are also included. At all four occulation points, the lapse rate of temperature was subdadiabatic up to altitudes in excess of 20 km. A pronounced temperature inversion was present above the surface at the Mariner 6 exit point. All four profiles exhibit a sharp, superadiabatic drop in temperature at high altitudes, with temperatures falling below the frost point of CO2. These results give a strong indication of frozen CO2 in the middle atmosphere of Mars.

  17. Paternity tests in Mexico: Results obtained in 3005 cases.

    PubMed

    García-Aceves, M E; Romero Rentería, O; Díaz-Navarro, X X; Rangel-Villalobos, H

    2018-04-01

    National and international reports regarding the paternity testing activity scarcely include information from Mexico and other Latin American countries. Therefore, we report different results from the analysis of 3005 paternity cases analyzed during a period of five years in a Mexican paternity testing laboratory. Motherless tests were the most frequent (77.27%), followed by trio cases (20.70%); the remaining 2.04% included different cases of kinship reconstruction. The paternity exclusion rate was 29.58%, higher but into the range reported by the American Association of Blood Banks (average 24.12%). We detected 65 mutations, most of them involving one-step (93.8% and the remaining were two-step mutations (6.2%) thus, we were able to estimate the paternal mutation rate for 17 different STR loci: 0.0018 (95% CI 0.0005-0.0047). Five triallelic patterns and 12 suspected null alleles were detected during this period; however, re-amplification of these samples with a different Human Identification (HID) kit confirmed the homozygous genotypes, which suggests that most of these exclusions actually are one-step mutations. HID kits with ≥20 STRs detected more exclusions, diminishing the rate of inconclusive results with isolated exclusions (<3 loci), and leading to higher paternity indexes (PI). However, the Powerplex 21 kit (20 STRs) and Powerplex Fusion kit (22 STRs) offered similar PI (p = 0.379) and average number of exclusions (PE) (p = 0.339) when a daughter was involved in motherless tests. In brief, besides to report forensic parameters from paternity tests in Mexico, results describe improvements to solve motherless paternity tests using HID kits with ≥20 STRs instead of one including 15 STRs. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  18. The effect of tandem-ovoid titanium applicator on points A, B, bladder, and rectum doses in gynecological brachytherapy using 192Ir

    PubMed Central

    Sadeghi, Mohammad Hosein; Mehdizadeh, Amir; Faghihi, Reza; Moharramzadeh, Vahed; Meigooni, Ali Soleimani

    2018-01-01

    Purpose The dosimetry procedure by simple superposition accounts only for the self-shielding of the source and does not take into account the attenuation of photons by the applicators. The purpose of this investigation is an estimation of the effects of the tandem and ovoid applicator on dose distribution inside the phantom by MCNP5 Monte Carlo simulations. Material and methods In this study, the superposition method is used for obtaining the dose distribution in the phantom without using the applicator for a typical gynecological brachytherapy (superposition-1). Then, the sources are simulated inside the tandem and ovoid applicator to identify the effect of applicator attenuation (superposition-2), and the dose at points A, B, bladder, and rectum were compared with the results of superposition. The exact dwell positions, times of the source, and positions of the dosimetry points were determined in images of a patient and treatment data of an adult woman patient from a cancer center. The MCNP5 Monte Carlo (MC) code was used for simulation of the phantoms, applicators, and the sources. Results The results of this study showed no significant differences between the results of superposition method and the MC simulations for different dosimetry points. The difference in all important dosimetry points was found to be less than 5%. Conclusions According to the results, applicator attenuation has no significant effect on the calculated points dose, the superposition method, adding the dose of each source obtained by the MC simulation, can estimate the dose to points A, B, bladder, and rectum with good accuracy. PMID:29619061

  19. Datum Feature Extraction and Deformation Analysis Method Based on Normal Vector of Point Cloud

    NASA Astrophysics Data System (ADS)

    Sun, W.; Wang, J.; Jin, F.; Liang, Z.; Yang, Y.

    2018-04-01

    In order to solve the problem lacking applicable analysis method in the application of three-dimensional laser scanning technology to the field of deformation monitoring, an efficient method extracting datum feature and analysing deformation based on normal vector of point cloud was proposed. Firstly, the kd-tree is used to establish the topological relation. Datum points are detected by tracking the normal vector of point cloud determined by the normal vector of local planar. Then, the cubic B-spline curve fitting is performed on the datum points. Finally, datum elevation and the inclination angle of the radial point are calculated according to the fitted curve and then the deformation information was analyzed. The proposed approach was verified on real large-scale tank data set captured with terrestrial laser scanner in a chemical plant. The results show that the method could obtain the entire information of the monitor object quickly and comprehensively, and reflect accurately the datum feature deformation.

  20. An improved maximum power point tracking method for a photovoltaic system

    NASA Astrophysics Data System (ADS)

    Ouoba, David; Fakkar, Abderrahim; El Kouari, Youssef; Dkhichi, Fayrouz; Oukarfi, Benyounes

    2016-06-01

    In this paper, an improved auto-scaling variable step-size Maximum Power Point Tracking (MPPT) method for photovoltaic (PV) system was proposed. To achieve simultaneously a fast dynamic response and stable steady-state power, a first improvement was made on the step-size scaling function of the duty cycle that controls the converter. An algorithm was secondly proposed to address wrong decision that may be made at an abrupt change of the irradiation. The proposed auto-scaling variable step-size approach was compared to some various other approaches from the literature such as: classical fixed step-size, variable step-size and a recent auto-scaling variable step-size maximum power point tracking approaches. The simulation results obtained by MATLAB/SIMULINK were given and discussed for validation.

  1. Solving differential equations for Feynman integrals by expansions near singular points

    NASA Astrophysics Data System (ADS)

    Lee, Roman N.; Smirnov, Alexander V.; Smirnov, Vladimir A.

    2018-03-01

    We describe a strategy to solve differential equations for Feynman integrals by powers series expansions near singular points and to obtain high precision results for the corresponding master integrals. We consider Feynman integrals with two scales, i.e. non-trivially depending on one variable. The corresponding algorithm is oriented at situations where canonical form of the differential equations is impossible. We provide a computer code constructed with the help of our algorithm for a simple example of four-loop generalized sunset integrals with three equal non-zero masses and two zero masses. Our code gives values of the master integrals at any given point on the real axis with a required accuracy and a given order of expansion in the regularization parameter ɛ.

  2. Feasibility and accuracy of molecular testing in specimens obtained with small biopsy forceps: comparison with the results of surgical specimens.

    PubMed

    Oki, Masahide; Yatabe, Yasushi; Saka, Hideo; Kitagawa, Chiyoe; Kogure, Yoshihito; Ichihara, Shu; Moritani, Suzuko

    2015-01-01

    During bronchoscopy, small biopsy forceps are increasingly used for the diagnosis of peripheral pulmonary lesions. However, it is unclear whether the formalin-fixed paraffin-embedded specimens sampled with the small biopsy forceps are suitable for the determination of genotypes which become indispensable for the management decision regarding patients with non-small cell lung cancer. The aim of this study was to evaluate the feasibility and accuracy of molecular testing in the specimens obtained with 1.5-mm small biopsy forceps. We examined specimens in 91 patients, who were enrolled in our previous 3 studies on the usefulness of thin bronchoscopes and given a diagnosis of non-small cell lung cancer by bronchoscopy with the 1.5-mm biopsy forceps, and then underwent surgical resection. An experienced pathologist examined paraffin-embedded specimens obtained by bronchoscopic biopsy or surgical resection in a blind fashion on epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK) rearrangements and KRAS mutations. Twenty-five (27%), 2 (2%) and 5 (5%) patients had an EGFR mutation, ALK rearrangement and KRAS mutation, respectively, based on the results in surgical specimens. EGFR, ALK and KRAS testing with bronchoscopic specimens was feasible in 82 (90%), 86 (95%) and 83 (91%) patients, respectively. If molecular testing was feasible, the accuracy of EGFR, ALK and KRAS testing with bronchoscopic specimens for the results with surgical specimens was 98, 100 and 98%, respectively. The results of molecular testing in the formalin-fixed paraffin-embedded specimens obtained with the small forceps, in which the genotype could be evaluated, correlated well with those in surgically resected specimens.

  3. A scalable and multi-purpose point cloud server (PCS) for easier and faster point cloud data management and processing

    NASA Astrophysics Data System (ADS)

    Cura, Rémi; Perret, Julien; Paparoditis, Nicolas

    2017-05-01

    In addition to more traditional geographical data such as images (rasters) and vectors, point cloud data are becoming increasingly available. Such data are appreciated for their precision and true three-Dimensional (3D) nature. However, managing point clouds can be difficult due to scaling problems and specificities of this data type. Several methods exist but are usually fairly specialised and solve only one aspect of the management problem. In this work, we propose a comprehensive and efficient point cloud management system based on a database server that works on groups of points (patches) rather than individual points. This system is specifically designed to cover the basic needs of point cloud users: fast loading, compressed storage, powerful patch and point filtering, easy data access and exporting, and integrated processing. Moreover, the proposed system fully integrates metadata (like sensor position) and can conjointly use point clouds with other geospatial data, such as images, vectors, topology and other point clouds. Point cloud (parallel) processing can be done in-base with fast prototyping capabilities. Lastly, the system is built on open source technologies; therefore it can be easily extended and customised. We test the proposed system with several billion points obtained from Lidar (aerial and terrestrial) and stereo-vision. We demonstrate loading speeds in the ˜50 million pts/h per process range, transparent-for-user and greater than 2 to 4:1 compression ratio, patch filtering in the 0.1 to 1 s range, and output in the 0.1 million pts/s per process range, along with classical processing methods, such as object detection.

  4. Scaling in the vicinity of the four-state Potts fixed point

    NASA Astrophysics Data System (ADS)

    Blöte, H. W. J.; Guo, Wenan; Nightingale, M. P.

    2017-08-01

    We study a self-dual generalization of the Baxter-Wu model, employing results obtained by transfer matrix calculations of the magnetic scaling dimension and the free energy. While the pure critical Baxter-Wu model displays the critical behavior of the four-state Potts fixed point in two dimensions, in the sense that logarithmic corrections are absent, the introduction of different couplings in the up- and down triangles moves the model away from this fixed point, so that logarithmic corrections appear. Real couplings move the model into the first-order range, away from the behavior displayed by the nearest-neighbor, four-state Potts model. We also use complex couplings, which bring the model in the opposite direction characterized by the same type of logarithmic corrections as present in the four-state Potts model. Our finite-size analysis confirms in detail the existing renormalization theory describing the immediate vicinity of the four-state Potts fixed point.

  5. The application of the pilot points in groundwater numerical inversion model

    NASA Astrophysics Data System (ADS)

    Hu, Bin; Teng, Yanguo; Cheng, Lirong

    2015-04-01

    Numerical inversion simulation of groundwater has been widely applied in groundwater. Compared to traditional forward modeling, inversion model has more space to study. Zones and inversing modeling cell by cell are conventional methods. Pilot points is a method between them. The traditional inverse modeling method often uses software dividing the model into several zones with a few parameters needed to be inversed. However, distribution is usually too simple for modeler and result of simulation deviation. Inverse cell by cell will get the most actual parameter distribution in theory, but it need computational complexity greatly and quantity of survey data for geological statistical simulation areas. Compared to those methods, pilot points distribute a set of points throughout the different model domains for parameter estimation. Property values are assigned to model cells by Kriging to ensure geological units within the parameters of heterogeneity. It will reduce requirements of simulation area geological statistics and offset the gap between above methods. Pilot points can not only save calculation time, increase fitting degree, but also reduce instability of numerical model caused by numbers of parameters and other advantages. In this paper, we use pilot point in a field which structure formation heterogeneity and hydraulics parameter was unknown. We compare inversion modeling results of zones and pilot point methods. With the method of comparative analysis, we explore the characteristic of pilot point in groundwater inversion model. First, modeler generates an initial spatially correlated field given a geostatistical model by the description of the case site with the software named Groundwater Vistas 6. Defining Kriging to obtain the value of the field functions over the model domain on the basis of their values at measurement and pilot point locations (hydraulic conductivity), then we assign pilot points to the interpolated field which have been divided into 4

  6. First results obtained within the European 'LAMA' programme (Large Active Mirrors in Aluminium)

    NASA Astrophysics Data System (ADS)

    Rozelot, J.-P.

    1993-11-01

    To investigate the feasibility of large size aluminum mirrors, studies have been undertaken in cooperation with European Southern Observatory (ESO), in the framework of a European program. The first phase, which is just now ended, addressed the following items: (1) tests to select the best aluminum alloy, (2) aluminum welding, homogeneity and stability, (3) aluminum high-precision machining, (4) nickel coating, (5) polishing of the nickel layer, (6) active optics. Furthermore, tests have been conducted to demonstrate that the quality of the mirrors is not altered at various temperatures and after a large number of aluminizing and cleaning cycles (corresponding to about 50 years' life). The mirror shape (whose specifications are fully compliant with those of the Very Large Telescope (VLT), as the program is conducted in cooperation with ESO) was computed under several causes of deformations: evidencing gravity as the predominant effect, and very low distortions as the high thermal conductivity limits the thermal transverse gradient to 0.025 C. Results show that it is quite possible to obtain high optical quality mirrors, mainly due to recent progress both in metallurgical processes (high precision machining -7 microns rms-) and active optics, that permit to correct residual aberrations of the surface. Such an alternative to classical glass mirrors will presently stand as a safe, economical solution that saves manufacturing time, for monolithic or segmented mirrors for innovative telescopes (e.g., lunar interferometric network).

  7. The melting point of lithium: an orbital-free first-principles molecular dynamics study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Mohan; Hung, Linda; Huang, Chen

    2013-08-25

    The melting point of liquid lithium near zero pressure is studied with large-scale orbital-free first-principles molecular dynamics (OF-FPMD) in the isobaric-isothermal ensemble. Here, we adopt the Wang-Govind-Carter (WGC) functional as our kinetic energy density functional (KEDF) and construct a bulk-derived local pseudopotential (BLPS) for Li. Our simulations employ both the ‘heat-until-melts’ method and the coexistence method. We predict 465 K as an upper bound of the melting point of Li from the ‘heat-until-melts’ method, while we predict 434 K as the melting point of Li from the coexistence method. These values compare well with an experimental melting point of 453more » K at zero pressure. Furthermore, we calculate a few important properties of liquid Li including the diffusion coefficients, pair distribution functions, static structure factors, and compressibilities of Li at 470 K and 725 K in the canonical ensemble. This theoretically-obtained results show good agreement with known experimental results, suggesting that OF-FPMD using a non-local KEDF and a BLPS is capable of accurately describing liquid metals.« less

  8. Stagnation-point heat-transfer rate predictions at aeroassist flight conditions

    NASA Technical Reports Server (NTRS)

    Gupta, Roop N.; Jones, Jim J.; Rochelle, William C.

    1992-01-01

    The results are presented for the stagnation-point heat-transfer rates used in the design process of the Aeroassist Flight Experiment (AFE) vehicle over its entire aeropass trajectory. The prediction methods used in this investigation demonstrate the application of computational fluid dynamics (CFD) techniques to a wide range of flight conditions and their usefulness in a design process. The heating rates were computed by a viscous-shock-layer (VSL) code at the lower altitudes and by a Navier-Stokes (N-S) code for the higher altitude cases. For both methods, finite-rate chemically reacting gas was considered, and a temperature-dependent wall-catalysis model was used. The wall temperature for each case was assumed to be radiative equilibrium temperature, based on total heating. The radiative heating was estimated by using a correlation equation. Wall slip was included in the N-S calculation method, and this method implicitly accounts for shock slip. The N-S/VSL combination of projection methods was established by comparison with the published benchmark flow-field code LAURA results at lower altitudes, and the direct simulation Monte Carlo results at higher altitude cases. To obtain the design heating rate over the entire forward face of the vehicle, a boundary-layer method (BLIMP code) that employs reacting chemistry and surface catalysis was used. The ratio of the VSL or N-S method prediction to that obtained from the boundary-layer method code at the stagnation point is used to define an adjustment factor, which accounts for the errors involved in using the boundary-layer method.

  9. Prediction of boiling points of organic compounds by QSPR tools.

    PubMed

    Dai, Yi-min; Zhu, Zhi-ping; Cao, Zhong; Zhang, Yue-fei; Zeng, Ju-lan; Li, Xun

    2013-07-01

    The novel electro-negativity topological descriptors of YC, WC were derived from molecular structure by equilibrium electro-negativity of atom and relative bond length of molecule. The quantitative structure-property relationships (QSPR) between descriptors of YC, WC as well as path number parameter P3 and the normal boiling points of 80 alkanes, 65 unsaturated hydrocarbons and 70 alcohols were obtained separately. The high-quality prediction models were evidenced by coefficient of determination (R(2)), the standard error (S), average absolute errors (AAE) and predictive parameters (Qext(2),RCV(2),Rm(2)). According to the regression equations, the influences of the length of carbon backbone, the size, the degree of branching of a molecule and the role of functional groups on the normal boiling point were analyzed. Comparison results with reference models demonstrated that novel topological descriptors based on the equilibrium electro-negativity of atom and the relative bond length were useful molecular descriptors for predicting the normal boiling points of organic compounds. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. a Threshold-Free Filtering Algorithm for Airborne LIDAR Point Clouds Based on Expectation-Maximization

    NASA Astrophysics Data System (ADS)

    Hui, Z.; Cheng, P.; Ziggah, Y. Y.; Nie, Y.

    2018-04-01

    Filtering is a key step for most applications of airborne LiDAR point clouds. Although lots of filtering algorithms have been put forward in recent years, most of them suffer from parameters setting or thresholds adjusting, which will be time-consuming and reduce the degree of automation of the algorithm. To overcome this problem, this paper proposed a threshold-free filtering algorithm based on expectation-maximization. The proposed algorithm is developed based on an assumption that point clouds are seen as a mixture of Gaussian models. The separation of ground points and non-ground points from point clouds can be replaced as a separation of a mixed Gaussian model. Expectation-maximization (EM) is applied for realizing the separation. EM is used to calculate maximum likelihood estimates of the mixture parameters. Using the estimated parameters, the likelihoods of each point belonging to ground or object can be computed. After several iterations, point clouds can be labelled as the component with a larger likelihood. Furthermore, intensity information was also utilized to optimize the filtering results acquired using the EM method. The proposed algorithm was tested using two different datasets used in practice. Experimental results showed that the proposed method can filter non-ground points effectively. To quantitatively evaluate the proposed method, this paper adopted the dataset provided by the ISPRS for the test. The proposed algorithm can obtain a 4.48 % total error which is much lower than most of the eight classical filtering algorithms reported by the ISPRS.

  11. Point- and line-based transformation models for high resolution satellite image rectification

    NASA Astrophysics Data System (ADS)

    Abd Elrahman, Ahmed Mohamed Shaker

    Rigorous mathematical models with the aid of satellite ephemeris data can present the relationship between the satellite image space and the object space. With government funded satellites, access to calibration and ephemeris data has allowed the development and use of these models. However, for commercial high-resolution satellites, which have been recently launched, these data are withheld from users, and therefore alternative empirical models should be used. In general, the existing empirical models are based on the use of control points and involve linking points in the image space and the corresponding points in the object space. But the lack of control points in some remote areas and the questionable accuracy of the identified discrete conjugate points provide a catalyst for the development of algorithms based on features other than control points. This research, concerned with image rectification and 3D geo-positioning determination using High-Resolution Satellite Imagery (HRSI), has two major objectives. First, the effects of satellite sensor characteristics, number of ground control points (GCPs), and terrain elevation variations on the performance of several point based empirical models are studied. Second, a new mathematical model, using only linear features as control features, or linear features with a minimum number of GCPs, is developed. To meet the first objective, several experiments for different satellites such as Ikonos, QuickBird, and IRS-1D have been conducted using different point based empirical models. Various data sets covering different terrain types are presented and results from representative sets of the experiments are shown and analyzed. The results demonstrate the effectiveness and the superiority of these models under certain conditions. From the results obtained, several alternatives to circumvent the effects of the satellite sensor characteristics, the number of GCPs, and the terrain elevation variations are introduced. To meet

  12. Automatic Monitoring of Tunnel Deformation Based on High Density Point Clouds Data

    NASA Astrophysics Data System (ADS)

    Du, L.; Zhong, R.; Sun, H.; Wu, Q.

    2017-09-01

    An automated method for tunnel deformation monitoring using high density point clouds data is presented. Firstly, the 3D point clouds data are converted to two-dimensional surface by projection on the XOY plane, the projection point set of central axis on XOY plane named Uxoy is calculated by combining the Alpha Shape algorithm with RANSAC (Random Sampling Consistency) algorithm, and then the projection point set of central axis on YOZ plane named Uyoz is obtained by highest and lowest points which are extracted by intersecting straight lines that through each point of Uxoy and perpendicular to the two -dimensional surface with the tunnel point clouds, Uxoy and Uyoz together form the 3D center axis finally. Secondly, the buffer of each cross section is calculated by K-Nearest neighbor algorithm, and the initial cross-sectional point set is quickly constructed by projection method. Finally, the cross sections are denoised and the section lines are fitted using the method of iterative ellipse fitting. In order to improve the accuracy of the cross section, a fine adjustment method is proposed to rotate the initial sectional plane around the intercept point in the horizontal and vertical direction within the buffer. The proposed method is used in Shanghai subway tunnel, and the deformation of each section in the direction of 0 to 360 degrees is calculated. The result shows that the cross sections becomes flat circles from regular circles due to the great pressure at the top of the tunnel

  13. Band-edge positions in G W : Effects of starting point and self-consistency

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Pasquarello, Alfredo

    2014-10-01

    We study the effect of starting point and self-consistency within G W on the band-edge positions of semiconductors and insulators. Compared to calculations based on a semilocal starting point, the use of a hybrid-functional starting point shows a larger quasiparticle correction for both band-edge states. When the self-consistent treatment is employed, the band-gap opening is found to result mostly from a shift of the valence-band edge. Within the non-self-consistent methods, we analyse the performance of empirical and nonempirical schemes in which the starting point is optimally tuned. We further assess the accuracy of the band-edge positions through the calculation of ionization potentials of surfaces. The ionization potentials for most systems are reasonably well described by one-shot calculations. However, in the case of TiO2, we find that the use of self-consistency is critical to obtain a good agreement with experiment.

  14. Two-point correlation function for Dirichlet L-functions

    NASA Astrophysics Data System (ADS)

    Bogomolny, E.; Keating, J. P.

    2013-03-01

    The two-point correlation function for the zeros of Dirichlet L-functions at a height E on the critical line is calculated heuristically using a generalization of the Hardy-Littlewood conjecture for pairs of primes in arithmetic progression. The result matches the conjectured random-matrix form in the limit as E → ∞ and, importantly, includes finite-E corrections. These finite-E corrections differ from those in the case of the Riemann zeta-function, obtained in Bogomolny and Keating (1996 Phys. Rev. Lett. 77 1472), by certain finite products of primes which divide the modulus of the primitive character used to construct the L-function in question.

  15. Real Time Precise Point Positioning: Preliminary Results for the Brazilian Region

    NASA Astrophysics Data System (ADS)

    Marques, Haroldo; Monico, João.; Hirokazu Shimabukuro, Milton; Aquino, Marcio

    2010-05-01

    GNSS positioning can be carried out in relative or absolute approach. In the last years, more attention has been driven to the real time precise point positioning (PPP). To achieve centimeter accuracy with this method in real time it is necessary to have available the satellites precise coordinates as well as satellites clocks corrections. The coordinates can be used from the predicted IGU ephemeris, but the satellites clocks must be estimated in a real time. It can be made from a GNSS network as can be seen from EUREF Permanent Network. The infra-structure to realize the PPP in real time is being available in Brazil through the Brazilian Continuous Monitoring Network (RBMC) together with the Sao Paulo State GNSS network which are transmitting GNSS data using NTRIP (Networked Transport of RTCM via Internet Protocol) caster. Based on this information it was proposed a PhD thesis in the Univ. Estadual Paulista (UNESP) aiming to investigate and develop the methodology to estimate the satellites clocks and realize PPP in real time. Then, software is being developed to process GNSS data in the real time PPP mode. A preliminary version of the software was called PPP_RT and is able to process GNSS code and phase data using precise ephemeris and satellites clocks. The PPP processing can be accomplished considering the absolute satellite antenna Phase Center Variation (PCV), Ocean Tide Loading (OTL), Earth Body Tide, among others. The first order ionospheric effects can be eliminated or minimized by ion-free combination or parameterized in the receiver-satellite direction using a stochastic process, e.g. random walk or white noise. In the case of ionosphere estimation, a pseudo-observable is introduced in the mathematical model for each satellite and the initial value can be computed from Klobuchar model or from Global Ionospheric Map (GIM). The adjustment is realized in the recursive mode and the DIA (Detection Identification and Adaptation) is used for quality control. In

  16. Effect of processing conditions on oil point pressure of moringa oleifera seed.

    PubMed

    Aviara, N A; Musa, W B; Owolarafe, O K; Ogunsina, B S; Oluwole, F A

    2015-07-01

    Seed oil expression is an important economic venture in rural Nigeria. The traditional techniques of carrying out the operation is not only energy sapping and time consuming but also wasteful. In order to reduce the tedium involved in the expression of oil from moringa oleifera seed and develop efficient equipment for carrying out the operation, the oil point pressure of the seed was determined under different processing conditions using a laboratory press. The processing conditions employed were moisture content (4.78, 6.00, 8.00 and 10.00 % wet basis), heating temperature (50, 70, 85 and 100 °C) and heating time (15, 20, 25 and 30 min). Results showed that the oil point pressure increased with increase in seed moisture content, but decreased with increase in heating temperature and heating time within the above ranges. Highest oil point pressure value of 1.1239 MPa was obtained at the processing conditions of 10.00 % moisture content, 50 °C heating temperature and 15 min heating time. The lowest oil point pressure obtained was 0.3164 MPa and it occurred at the moisture content of 4.78 %, heating temperature of 100 °C and heating time of 30 min. Analysis of Variance (ANOVA) showed that all the processing variables and their interactions had significant effect on the oil point pressure of moringa oleifera seed at 1 % level of significance. This was further demonstrated using Response Surface Methodology (RSM). Tukey's test and Duncan's Multiple Range Analysis successfully separated the means and a multiple regression equation was used to express the relationship existing between the oil point pressure of moringa oleifera seed and its moisture content, processing temperature, heating time and their interactions. The model yielded coefficients that enabled the oil point pressure of the seed to be predicted with very high coefficient of determination.

  17. Formation Energies of Native Point Defects in Strained layer Superlattices (Postprint)

    DTIC Science & Technology

    2017-06-05

    AFRL-RX-WP-JA-2017-0440 FORMATION ENERGIES OF NATIVE POINT DEFECTS IN STRAINED-LAYER SUPERLATTICES (POSTPRINT) Zhi Gang Yu...2017 Interim 11 September 2013 – 31 May 2017 4. TITLE AND SUBTITLE FORMATION ENERGIES OF NATIVE POINT DEFECTS IN STRAINED-LAYER SUPERLATTICES...Hamiltonian, tight-binding Hamiltonian, and Green’s function techniques to obtain energy levels arising from native point defects (NPDs) in InAs-GaSb and

  18. Pivots for pointing: visually-monitored pointing has higher arm elevations than pointing blindfolded.

    PubMed

    Wnuczko, Marta; Kennedy, John M

    2011-10-01

    Observers pointing to a target viewed directly may elevate their fingertip close to the line of sight. However, pointing blindfolded, after viewing the target, they may pivot lower, from the shoulder, aligning the arm with the target as if reaching to the target. Indeed, in Experiment 1 participants elevated their arms more in visually monitored than blindfolded pointing. In Experiment 2, pointing to a visible target they elevated a short pointer more than a long one, raising its tip to the line of sight. In Experiment 3, the Experimenter aligned the participant's arm with the target. Participants judged they were pointing below a visually monitored target. In Experiment 4, participants viewing another person pointing, eyes-open or eyes-closed, judged the target was aligned with the pointing arm. In Experiment 5, participants viewed their arm and the target via a mirror and posed their arm so that it was aligned with the target. Arm elevation was higher in pointing directly.

  19. Dual-point reflective refractometer based on parallel no-core fiber/FBG structure

    NASA Astrophysics Data System (ADS)

    Guo, Cuijuan; Niu, Panpan; Wang, Juan; Zhao, Junfa; Zhang, Cheng

    2018-01-01

    A novel dual-point reflective fiber-optic refractometer based on multimode interference (MMI) effect and fiber Bragg grating (FBG) reflection is proposed and experimentally demonstrated, which adopts parallel structure. Each point of the refractometer consists of a single mode-no core-single mode fiber (SNS) structure cascaded with a FBG. Assisted by the reflection of FBG, refractive index (RI) measurement can be achieved by monitoring the peak power variation of the reflected FBG spectrum. By selecting different length of the no core fiber and center wavelength of the FBG, independent dual-point refractometer is easily realized. Experiment results show that the refractometer has a nonlinear relationship between the surrounding refractive index (SRI) and the peak power of the reflected FBG spectrum in the RI range of 1.3330-1.4086. Linear relationship can be approximately obtained by dividing the measuring range into 1.3330-1.3611 and 1.3764-1.4086. In the RI range of 1.3764-1.4086, the two sensing points have higher RI sensitivities of 319.34 dB/RIU and 211.84 dB/RIU, respectively.

  20. Standardization of a fluconazole bioassay and correlation of results with those obtained by high-pressure liquid chromatography.

    PubMed Central

    Rex, J H; Hanson, L H; Amantea, M A; Stevens, D A; Bennett, J E

    1991-01-01

    An improved bioassay for fluconazole was developed. This assay is sensitive in the clinically relevant range (2 to 40 micrograms/ml) and analyzes plasma, serum, and cerebrospinal fluid specimens; bioassay results correlate with results obtained by high-pressure liquid chromatography (HPLC). Bioassay and HPLC analyses of spiked plasma, serum, and cerebrospinal fluid samples (run as unknowns) gave good agreement with expected values. Analysis of specimens from patients gave equivalent results by both HPLC and bioassay. HPLC had a lower within-run coefficient of variation (less than 2.5% for HPLC versus less than 11% for bioassay) and a lower between-run coefficient of variation (less than 5% versus less than 12% for bioassay) and was more sensitive (lower limit of detection, 0.1 micrograms/ml [versus 2 micrograms/ml for bioassay]). The bioassay is, however, sufficiently accurate and sensitive for clinical specimens, and its relative simplicity, low sample volume requirement, and low equipment cost should make it the technique of choice for analysis of routine clinical specimens. PMID:1854166

  1. Analysis of point-to-point lung motion with full inspiration and expiration CT data using non-linear optimization method: optimal geometric assumption model for the effective registration algorithm

    NASA Astrophysics Data System (ADS)

    Kim, Namkug; Seo, Joon Beom; Heo, Jeong Nam; Kang, Suk-Ho

    2007-03-01

    The study was conducted to develop a simple model for more robust lung registration of volumetric CT data, which is essential for various clinical lung analysis applications, including the lung nodule matching in follow up CT studies, semi-quantitative assessment of lung perfusion, and etc. The purpose of this study is to find the most effective reference point and geometric model based on the lung motion analysis from the CT data sets obtained in full inspiration (In.) and expiration (Ex.). Ten pairs of CT data sets in normal subjects obtained in full In. and Ex. were used in this study. Two radiologists were requested to draw 20 points representing the subpleural point of the central axis in each segment. The apex, hilar point, and center of inertia (COI) of each unilateral lung were proposed as the reference point. To evaluate optimal expansion point, non-linear optimization without constraints was employed. The objective function is sum of distances from the line, consist of the corresponding points between In. and Ex. to the optimal point x. By using the nonlinear optimization, the optimal points was evaluated and compared between reference points. The average distance between the optimal point and each line segment revealed that the balloon model was more suitable to explain the lung expansion model. This lung motion analysis based on vector analysis and non-linear optimization shows that balloon model centered on the center of inertia of lung is most effective geometric model to explain lung expansion by breathing.

  2. The Annular Suspension and Pointing (ASP) system for space experiments and predicted pointing accuracies

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Joshi, S. M.

    1975-01-01

    An annular suspension and pointing system consisting of pointing assemblies for coarse and vernier pointing is described. The first assembly is attached to a carrier spacecraft (e.g., the space shuttle) and consists of an azimuth gimbal and an elevation gimbal which provide 'coarse' pointing. The second or vernier pointing assembly is made up of magnetic actuators of suspension and fine pointing, roll motor segments, and an instrument or experiment mounting plate around which is attached a continuous annular rim similar to that used in the annular momentum control device. The rim provides appropriate magnetic circuits for the actuators and the roll motor segments for any instrument roll position. The results of a study to determine the pointing accuracy of the system in the presence of crew motion disturbances are presented. Typical 3 sigma worst-case errors are found to be of the order of 0.001 arc-second.

  3. Maximum power point tracker for photovoltaic power plants

    NASA Astrophysics Data System (ADS)

    Arcidiacono, V.; Corsi, S.; Lambri, L.

    The paper describes two different closed-loop control criteria for the maximum power point tracking of the voltage-current characteristic of a photovoltaic generator. The two criteria are discussed and compared, inter alia, with regard to the setting-up problems that they pose. Although a detailed analysis is not embarked upon, the paper also provides some quantitative information on the energy advantages obtained by using electronic maximum power point tracking systems, as compared with the situation in which the point of operation of the photovoltaic generator is not controlled at all. Lastly, the paper presents two high-efficiency MPPT converters for experimental photovoltaic plants of the stand-alone and the grid-interconnected type.

  4. The effect of tandem-ovoid titanium applicator on points A, B, bladder, and rectum doses in gynecological brachytherapy using 192Ir.

    PubMed

    Sadeghi, Mohammad Hosein; Sina, Sedigheh; Mehdizadeh, Amir; Faghihi, Reza; Moharramzadeh, Vahed; Meigooni, Ali Soleimani

    2018-02-01

    The dosimetry procedure by simple superposition accounts only for the self-shielding of the source and does not take into account the attenuation of photons by the applicators. The purpose of this investigation is an estimation of the effects of the tandem and ovoid applicator on dose distribution inside the phantom by MCNP5 Monte Carlo simulations. In this study, the superposition method is used for obtaining the dose distribution in the phantom without using the applicator for a typical gynecological brachytherapy (superposition-1). Then, the sources are simulated inside the tandem and ovoid applicator to identify the effect of applicator attenuation (superposition-2), and the dose at points A, B, bladder, and rectum were compared with the results of superposition. The exact dwell positions, times of the source, and positions of the dosimetry points were determined in images of a patient and treatment data of an adult woman patient from a cancer center. The MCNP5 Monte Carlo (MC) code was used for simulation of the phantoms, applicators, and the sources. The results of this study showed no significant differences between the results of superposition method and the MC simulations for different dosimetry points. The difference in all important dosimetry points was found to be less than 5%. According to the results, applicator attenuation has no significant effect on the calculated points dose, the superposition method, adding the dose of each source obtained by the MC simulation, can estimate the dose to points A, B, bladder, and rectum with good accuracy.

  5. Infinite-disorder critical points of models with stretched exponential interactions

    NASA Astrophysics Data System (ADS)

    Juhász, Róbert

    2014-09-01

    We show that an interaction decaying as a stretched exponential function of distance, J(l)˜ e-cl^a , is able to alter the universality class of short-range systems having an infinite-disorder critical point. To do so, we study the low-energy properties of the random transverse-field Ising chain with the above form of interaction by a strong-disorder renormalization group (SDRG) approach. We find that the critical behavior of the model is controlled by infinite-disorder fixed points different from those of the short-range model if 0 < a < 1/2. In this range, the critical exponents calculated analytically by a simplified SDRG scheme are found to vary with a, while, for a > 1/2, the model belongs to the same universality class as its short-range variant. The entanglement entropy of a block of size L increases logarithmically with L at the critical point but, unlike the short-range model, the prefactor is dependent on disorder in the range 0 < a < 1/2. Numerical results obtained by an improved SDRG scheme are found to be in agreement with the analytical predictions. The same fixed points are expected to describe the critical behavior of, among others, the random contact process with stretched exponentially decaying activation rates.

  6. The Melting Point of Palladium Using Miniature Fixed Points of Different Ceramic Materials: Part II—Analysis of Melting Curves and Long-Term Investigation

    NASA Astrophysics Data System (ADS)

    Edler, F.; Huang, K.

    2016-12-01

    Fifteen miniature fixed-point cells made of three different ceramic crucible materials (Al2O3, ZrO2, and Al2O3(86 %)+ZrO2(14 %)) were filled with pure palladium and used to calibrate type B thermocouples (Pt30 %Rh/Pt6 %Rh). A critical point by using miniature fixed points with small amounts of fixed-point material is the analysis of the melting curves, which are characterized by significant slopes during the melting process compared to flat melting plateaus obtainable using conventional fixed-point cells. The method of the extrapolated starting point temperature using straight line approximation of the melting plateau was applied to analyze the melting curves. This method allowed an unambiguous determination of an electromotive force (emf) assignable as melting temperature. The strict consideration of two constraints resulted in a unique, repeatable and objective method to determine the emf at the melting temperature within an uncertainty of about 0.1 μ V. The lifetime and long-term stability of the miniature fixed points was investigated by performing more than 100 melt/freeze cycles for each crucible of the different ceramic materials. No failure of the crucibles occurred indicating an excellent mechanical stability of the investigated miniature cells. The consequent limitation of heating rates to values below {± }3.5 K min^{-1} above 1100° C and the carefully and completely filled crucibles (the liquid palladium occupies the whole volume of the crucible) are the reasons for successfully preventing the crucibles from breaking. The thermal stability of the melting temperature of palladium was excellent when using the crucibles made of Al2O3(86 %)+ZrO2(14 %) and ZrO2. Emf drifts over the total duration of the long-term investigation were below a temperature equivalent of about 0.1 K-0.2 K.

  7. Symbolic computation of the Birkhoff normal form in the problem of stability of the triangular libration points

    NASA Astrophysics Data System (ADS)

    Shevchenko, I. I.

    2008-05-01

    The problem of stability of the triangular libration points in the planar circular restricted three-body problem is considered. A software package, intended for normalization of autonomous Hamiltonian systems by means of computer algebra, is designed so that normalization problems of high analytical complexity could be solved. It is used to obtain the Birkhoff normal form of the Hamiltonian in the given problem. The normalization is carried out up to the 6th order of expansion of the Hamiltonian in the coordinates and momenta. Analytical expressions for the coefficients of the normal form of the 6th order are derived. Though intermediary expressions occupy gigabytes of the computer memory, the obtained coefficients of the normal form are compact enough for presentation in typographic format. The analogue of the Deprit formula for the stability criterion is derived in the 6th order of normalization. The obtained floating-point numerical values for the normal form coefficients and the stability criterion confirm the results by Markeev (1969) and Coppola and Rand (1989), while the obtained analytical and exact numeric expressions confirm the results by Meyer and Schmidt (1986) and Schmidt (1989). The given computational problem is solved without constructing a specialized algebraic processor, i.e., the designed computer algebra package has a broad field of applicability.

  8. Low-energy transfers to cislunar periodic orbits visiting triangular libration points

    NASA Astrophysics Data System (ADS)

    Lei, Hanlun; Xu, Bo

    2018-01-01

    This paper investigates the cislunar periodic orbits that pass through triangular libration points of the Earth-Moon system and studies the techniques on design low-energy transfer trajectories. In order to compute periodic orbits, families of impulsive transfers between triangular libration points are taken to generate the initial guesses of periodic orbits, and multiple shooting techniques are applied to solving the problem. Then, varieties of periodic orbits in cislunar space are obtained, and stability analysis shows that the majority of them are unstable. Among these periodic orbits, an unstable periodic orbit in near 3:2 resonance with the Moon is taken as the nominal orbit of an assumed mission. As the stable manifolds of the target orbit could approach the Moon, low-energy transfer trajectories can be designed by combining lunar gravity assist with the invariant manifold structure of the target orbit. In practice, both the natural and perturbed invariant manifolds are considered to obtain the low-energy transfers, which are further refined to the Sun-perturbed Earth-Moon system. Results indicate that (a) compared to the case of natural invariant manifolds, the optimal transfers using perturbed invariant manifolds could reduce flight time at least 50 days, (b) compared to the cheapest direct transfer, the optimal low-energy transfer obtained by combining lunar gravity assist and invariant manifolds could save on-board fuel consumption more than 200 m/s, and (c) by taking advantage of the gravitational perturbation of the Sun, the low-energy transfers could save more fuel consumption than the corresponding ones obtained in the Earth-Moon system.

  9. a Point Cloud Classification Approach Based on Vertical Structures of Ground Objects

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Hu, Q.; Hu, W.

    2018-04-01

    This paper proposes a novel method for point cloud classification using vertical structural characteristics of ground objects. Since urbanization develops rapidly nowadays, urban ground objects also change frequently. Conventional photogrammetric methods cannot satisfy the requirements of updating the ground objects' information efficiently, so LiDAR (Light Detection and Ranging) technology is employed to accomplish this task. LiDAR data, namely point cloud data, can obtain detailed three-dimensional coordinates of ground objects, but this kind of data is discrete and unorganized. To accomplish ground objects classification with point cloud, we first construct horizontal grids and vertical layers to organize point cloud data, and then calculate vertical characteristics, including density and measures of dispersion, and form characteristic curves for each grids. With the help of PCA processing and K-means algorithm, we analyze the similarities and differences of characteristic curves. Curves that have similar features will be classified into the same class and point cloud correspond to these curves will be classified as well. The whole process is simple but effective, and this approach does not need assistance of other data sources. In this study, point cloud data are classified into three classes, which are vegetation, buildings, and roads. When horizontal grid spacing and vertical layer spacing are 3 m and 1 m respectively, vertical characteristic is set as density, and the number of dimensions after PCA processing is 11, the overall precision of classification result is about 86.31 %. The result can help us quickly understand the distribution of various ground objects.

  10. Gas-chromatography and UV-spectroscopy of Hymenoptera venoms obtained by trivial centrifugation.

    PubMed

    Fox, Eduardo G P; Xu, Meng; Wang, Lei; Chen, Li; Lu, Yong-Yue

    2018-06-01

    This paper summarises gas-chromatography (GC-MS) and preliminary UV-spectroscopy analyses data of fresh, unmodified venom of aculeate hymenopterans (ants, bees, wasps), mainly focusing on red imported fire ants. No solvents nor fractionation were used at any point, which is a novel approach to describing integral toxins cocktails as proposed by Fox et al. (2018a) [1] 10.1016/j.toxicon.2018.02.050 where these results are discussed in deeper details. Herein we focus on further characterising the obtained venom extracted through a novel approach. Pertaining raw data is accessible from Fox et al. (2018b) [2] 10.17632/cpnscw2gkc.1 including further relevant information regarding the used insects, machinery settings, chemical standards.

  11. Interior point techniques for LP and NLP

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Evtushenko, Y.

    By using surjective mapping the initial constrained optimization problem is transformed to a problem in a new space with only equality constraints. For the numerical solution of the latter problem we use the generalized gradient-projection method and Newton`s method. After inverse transformation to the initial space we obtain the family of numerical methods for solving optimization problems with equality and inequality constraints. In the linear programming case after some simplification we obtain Dikin`s algorithm, affine scaling algorithm and generalized primal dual interior point linear programming algorithm.

  12. Point pattern analysis of FIA data

    Treesearch

    Chris Woodall

    2002-01-01

    Point pattern analysis is a branch of spatial statistics that quantifies the spatial distribution of points in two-dimensional space. Point pattern analysis was conducted on stand stem-maps from FIA fixed-radius plots to explore point pattern analysis techniques and to determine the ability of pattern descriptions to describe stand attributes. Results indicate that the...

  13. The stagnation-point flow towards a shrinking sheet with homogeneous - heterogeneous reactions effects: A stability analysis

    NASA Astrophysics Data System (ADS)

    Ismail, Nurul Syuhada; Arifin, Norihan Md.; Bachok, Norfifah; Mahiddin, Norhasimah

    2017-01-01

    A numerical study is performed to evaluate the problem of stagnation - point flow towards a shrinking sheet with homogeneous - heterogeneous reaction effects. By using non-similar transformation, the governing equations be able to reduced to an ordinary differential equation. Then, results of the equations can be obtained numerically by shooting method with maple implementation. Based on the numerical results obtained, the velocity ratio parameter λ< 0, the dual solutions do exist. Then, the stability analysis is carried out to determine which solution is more stable between both of the solutions by bvp4c solver in Matlab.

  14. Accurate dew-point measurement over a wide temperature range using a quartz crystal microbalance dew-point sensor

    NASA Astrophysics Data System (ADS)

    Kwon, Su-Yong; Kim, Jong-Chul; Choi, Buyng-Il

    2008-11-01

    Quartz crystal microbalance (QCM) dew-point sensors are based on frequency measurement, and so have fast response time, high sensitivity and high accuracy. Recently, we have reported that they have the very convenient attribute of being able to distinguish between supercooled dew and frost from a single scan through the resonant frequency of the quartz resonator as a function of the temperature. In addition to these advantages, by using three different types of heat sinks, we have developed a QCM dew/frost-point sensor with a very wide working temperature range (-90 °C to 15 °C). The temperature of the quartz surface can be obtained effectively by measuring the temperature of the quartz crystal holder and using temperature compensation curves (which showed a high level of repeatability and reproducibility). The measured dew/frost points showed very good agreement with reference values and were within ±0.1 °C over the whole temperature range.

  15. Classification of the Lie and Noether point symmetries for the Wave and the Klein-Gordon equations in pp-wave spacetimes

    NASA Astrophysics Data System (ADS)

    Paliathanasis, A.; Tsamparlis, M.; Mustafa, M. T.

    2018-02-01

    A complete classification of the Lie and Noether point symmetries for the Klein-Gordon and the wave equation in pp-wave spacetimes is obtained. The classification analysis is carried out by reducing the problem of the determination of the point symmetries to the problem of existence of conformal killing vectors on the pp-wave spacetimes. Employing the existing results for the isometry classes of the pp-wave spacetimes, the functional form of the potential is determined for which the Klein-Gordon equation admits point symmetries and Noetherian conservation law. Finally the Lie and Noether point symmetries of the wave equation are derived.

  16. In-vitro evaluation of the accuracy of conventional and digital methods of obtaining full-arch dental impressions.

    PubMed

    Ender, Andreas; Mehl, Albert

    2015-01-01

    To investigate the accuracy of conventional and digital impression methods used to obtain full-arch impressions by using an in-vitro reference model. Eight different conventional (polyether, POE; vinylsiloxanether, VSE; direct scannable vinylsiloxanether, VSES; and irreversible hydrocolloid, ALG) and digital (CEREC Bluecam, CER; CEREC Omnicam, OC; Cadent iTero, ITE; and Lava COS, LAV) full-arch impressions were obtained from a reference model with a known morphology, using a highly accurate reference scanner. The impressions obtained were then compared with the original geometry of the reference model and within each test group. A point-to-point measurement of the surface of the model using the signed nearest neighbour method resulted in a mean (10%-90%)/2 percentile value for the difference between the impression and original model (trueness) as well as the difference between impressions within a test group (precision). Trueness values ranged from 11.5 μm (VSE) to 60.2 μm (POE), and precision ranged from 12.3 μm (VSE) to 66.7 μm (POE). Among the test groups, VSE, VSES, and CER showed the highest trueness and precision. The deviation pattern varied with the impression method. Conventional impressions showed high accuracy across the full dental arch in all groups, except POE and ALG. Conventional and digital impression methods show differences regarding full-arch accuracy. Digital impression systems reveal higher local deviations of the full-arch model. Digital intraoral impression systems do not show superior accuracy compared to highly accurate conventional impression techniques. However, they provide excellent clinical results within their indications applying the correct scanning technique.

  17. Stress-strain state of a rock mass in the vicinity of the meeting point of intersecting and branching workings

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Konstantinova, S.A.; Spirkov, V.L.; Sokolov, V.Yu.

    1987-07-01

    The results of solving the problems of the stress-strain state of peripheral rock in the vicinity of the meeting point of two workings of intersection and branching type are presented. Values of the load coefficients are obtained, as well as values of the dimensions of the zone of influence of the meeting point and the conventional zone of inelastic deformations. Intersection and branching of workings at various angles are considered.

  18. Improvement of gel strength and melting point of fish gelatin by addition of coenhancers using response surface methodology.

    PubMed

    Koli, Jayappa M; Basu, Subrata; Nayak, Binay B; Kannuchamy, Nagalakshmi; Gudipati, Venkateshwarlu

    2011-08-01

    Fish gelatin is a potential alternative to mammalian gelatin. However, poor gel strength and low melting point limit its applications. The study was aimed at improving these properties by adding coenhancers in the range obtained from response surface methodology (RSM) by using Box-Behnken design. Three different coenhancers, MgSO₄, sucrose, and transglutaminase were used as the independent variables for improving the gel strength and melting point of gelatin extracted from Tiger-toothed croaker (Otolithes ruber). Addition of coenhancers at different combinations resulted gel strength and melting point in the range of 150.5 to 240.5 g and 19.5 to 22.5 °C, respectively. The optimal concentrations of coenhancers for predicted maximum gel strength (242.8 g) obtained by RSM were 0.23 M MgSO₄, 12.60% sucrose (w/v), and 5.92 mg/g transglutaminase and for predicted maximum melting point (22.57 °C), the values were 0.24 M MgSO₄, 10.44% sucrose (w/v), and 5.72 mg/g transglutaminase. By addition of coenhancers at these optimal concentrations in verification experiments, the gel strength and melting point were improved from 170 to 240.89 g and 20.3 to 22.7 °C, respectively. These experimental values agreed well with the predicted values demonstrating the fitness of the models. Results from the present study clearly revealed that the addition of coenhancers at a particular combination can improve the gel strength and melting point of fish gelatin to enhance its range of applications. There is a growing interest in the use of fish gelatin as an alternative to mammalian gelatin. However, poor gel strength and low melting point of fish gelatin have limited its commercial applications. The gel strength and melting point of fish gelatin can be increased by incorporation of coenhancers such as magnesium sulphate, sucrose, and transglutaminase. Results of this work help to produce the fish gelatin suitable for wide range of applications in the food industry. © 2011 Institute

  19. Branch-point energies and the band-structure lineup at Schottky contacts and heterostrucures

    NASA Astrophysics Data System (ADS)

    Mönch, Winfried

    2011-06-01

    Empirical branch-point energies of Si, the group-III nitrides AlN, GaN, and InN, and the group-II and group-III oxides MgO, ZnO, Al2O3 and In2O3 are determined from experimental valance-band offsets of their heterostructures. For Si, GaN, and MgO, these values agree with the branch-point energies obtained from the barrier heights of their Schottky contacts. The empirical branch-point energies of Si and the group-III nitrides are in very good agreement with results of previously published calculations using quite different approaches such as the empirical tight-binding approximation and modern electronic-structure theory. In contrast, the empirical branch-point energies of the group-II and group-III oxides do not confirm the respective theoretical results. As at Schottky contacts, the band-structure lineup at heterostructures is also made up of a zero-charge-transfer term and an intrinsic electric-dipole contribution. Hence, valence-band offsets are not equal to the difference of the branch-point energies of the two semiconductors forming the heterostructure. The electric-dipole term may be described by the electronegativity difference of the two solids in contact. A detailed analysis of experimental Si Schottky barrier heights and heterostructure valence-band offsets explains and proves these conclusions.

  20. International normalized ratio (INR) testing in Europe: between-laboratory comparability of test results obtained by Quick and Owren reagents.

    PubMed

    Meijer, Piet; Kynde, Karin; van den Besselaar, Antonius M H P; Van Blerk, Marjan; Woods, Timothy A L

    2018-04-12

    This study was designed to obtain an overview of the analytical quality of the prothrombin time, reported as international normalized ratio (INR) and to assess the variation of INR results between European laboratories, the difference between Quick-type and Owren-type methods and the effect of using local INR calibration or not. In addition, we assessed the variation in INR results obtained for a single donation in comparison with a pool of several plasmas. A set of four different lyophilized plasma samples were distributed via national EQA organizations to participating laboratories for INR measurement. Between-laboratory variation was lower in the Owren group than in the Quick group (on average: 6.7% vs. 8.1%, respectively). Differences in the mean INR value between the Owren and Quick group were relatively small (<0.20 INR). Between-laboratory variation was lower after local INR calibration (CV: 6.7% vs. 8.6%). For laboratories performing local calibration, the between-laboratory variation was quite similar for the Owren and Quick group (on average: 6.5% and 6.7%, respectively). Clinically significant differences in INR results (difference in INR>0.5) were observed between different reagents. No systematic significant differences in the between-laboratory variation for a single-plasma sample and a pooled plasma sample were observed. The comparability for laboratories using local calibration of their thromboplastin reagent is better than for laboratories not performing local calibration. Implementing local calibration is strongly recommended for the measurement of INR.

  1. Selection of floating-point or fixed-point for adaptive noise canceller in somatosensory evoked potential measurement.

    PubMed

    Shen, Chongfei; Liu, Hongtao; Xie, Xb; Luk, Keith Dk; Hu, Yong

    2007-01-01

    Adaptive noise canceller (ANC) has been used to improve signal to noise ratio (SNR) of somsatosensory evoked potential (SEP). In order to efficiently apply the ANC in hardware system, fixed-point algorithm based ANC can achieve fast, cost-efficient construction, and low-power consumption in FPGA design. However, it is still questionable whether the SNR improvement performance by fixed-point algorithm is as good as that by floating-point algorithm. This study is to compare the outputs of ANC by floating-point and fixed-point algorithm ANC when it was applied to SEP signals. The selection of step-size parameter (micro) was found different in fixed-point algorithm from floating-point algorithm. In this simulation study, the outputs of fixed-point ANC showed higher distortion from real SEP signals than that of floating-point ANC. However, the difference would be decreased with increasing micro value. In the optimal selection of micro, fixed-point ANC can get as good results as floating-point algorithm.

  2. An Efficient Method to Create Digital Terrain Models from Point Clouds Collected by Mobile LiDAR Systems

    NASA Astrophysics Data System (ADS)

    Gézero, L.; Antunes, C.

    2017-05-01

    The digital terrain models (DTM) assume an essential role in all types of road maintenance, water supply and sanitation projects. The demand of such information is more significant in developing countries, where the lack of infrastructures is higher. In recent years, the use of Mobile LiDAR Systems (MLS) proved to be a very efficient technique in the acquisition of precise and dense point clouds. These point clouds can be a solution to obtain the data for the production of DTM in remote areas, due mainly to the safety, precision, speed of acquisition and the detail of the information gathered. However, the point clouds filtering and algorithms to separate "terrain points" from "no terrain points", quickly and consistently, remain a challenge that has caught the interest of researchers. This work presents a method to create the DTM from point clouds collected by MLS. The method is based in two interactive steps. The first step of the process allows reducing the cloud point to a set of points that represent the terrain's shape, being the distance between points inversely proportional to the terrain variation. The second step is based on the Delaunay triangulation of the points resulting from the first step. The achieved results encourage a wider use of this technology as a solution for large scale DTM production in remote areas.

  3. Marked point process for modelling seismic activity (case study in Sumatra and Java)

    NASA Astrophysics Data System (ADS)

    Pratiwi, Hasih; Sulistya Rini, Lia; Wayan Mangku, I.

    2018-05-01

    Earthquake is a natural phenomenon that is random, irregular in space and time. Until now the forecast of earthquake occurrence at a location is still difficult to be estimated so that the development of earthquake forecast methodology is still carried out both from seismology aspect and stochastic aspect. To explain the random nature phenomena, both in space and time, a point process approach can be used. There are two types of point processes: temporal point process and spatial point process. The temporal point process relates to events observed over time as a sequence of time, whereas the spatial point process describes the location of objects in two or three dimensional spaces. The points on the point process can be labelled with additional information called marks. A marked point process can be considered as a pair (x, m) where x is the point of location and m is the mark attached to the point of that location. This study aims to model marked point process indexed by time on earthquake data in Sumatra Island and Java Island. This model can be used to analyse seismic activity through its intensity function by considering the history process up to time before t. Based on data obtained from U.S. Geological Survey from 1973 to 2017 with magnitude threshold 5, we obtained maximum likelihood estimate for parameters of the intensity function. The estimation of model parameters shows that the seismic activity in Sumatra Island is greater than Java Island.

  4. C-class functions with new approach on coincidence point results for generalized [Formula: see text]-weakly contractions in ordered b-metric spaces.

    PubMed

    Mustafa, Zead; Jaradat, Mohammed M M; Ansari, Arslan Hojat; Popović, Branislav Z; Jaradat, Husein M

    2016-01-01

    In this paper, by using the C-class functions and a new approach we present some coincidence point results for four mappings satisfying generalized [Formula: see text]-weakly contractive condition in the setting of ordered b-metric spaces. Also, an application and example are given to support our results.

  5. Point-source inversion techniques

    NASA Astrophysics Data System (ADS)

    Langston, Charles A.; Barker, Jeffrey S.; Pavlin, Gregory B.

    1982-11-01

    A variety of approaches for obtaining source parameters from waveform data using moment-tensor or dislocation point source models have been investigated and applied to long-period body and surface waves from several earthquakes. Generalized inversion techniques have been applied to data for long-period teleseismic body waves to obtain the orientation, time function and depth of the 1978 Thessaloniki, Greece, event, of the 1971 San Fernando event, and of several events associated with the 1963 induced seismicity sequence at Kariba, Africa. The generalized inversion technique and a systematic grid testing technique have also been used to place meaningful constraints on mechanisms determined from very sparse data sets; a single station with high-quality three-component waveform data is often sufficient to discriminate faulting type (e.g., strike-slip, etc.). Sparse data sets for several recent California earthquakes, for a small regional event associated with the Koyna, India, reservoir, and for several events at the Kariba reservoir have been investigated in this way. Although linearized inversion techniques using the moment-tensor model are often robust, even for sparse data sets, there are instances where the simplifying assumption of a single point source is inadequate to model the data successfully. Numerical experiments utilizing synthetic data and actual data for the 1971 San Fernando earthquake graphically demonstrate that severe problems may be encountered if source finiteness effects are ignored. These techniques are generally applicable to on-line processing of high-quality digital data, but source complexity and inadequacy of the assumed Green's functions are major problems which are yet to be fully addressed.

  6. A MEMS-based super fast dew point hygrometer—construction and medical applications

    NASA Astrophysics Data System (ADS)

    Jachowicz, Ryszard S.; Weremczuk, Jerzy; Paczesny, Daniel; Tarapata, Grzegorz

    2009-12-01

    The paper shows how MEMS (micro-electro-mechanical system) technology and a modified principle of fast temperature control (by heat injection instead of careful control of cooling) can considerably improve the dynamic parameters of dew point hygrometers. Some aspects of MEMS-type integrated sensor construction and technology, whole measurement system design, the control algorithm to run the system as well as empirical dynamic parameters from the tests are discussed too. The hygrometer can easily obtain five to six measurements per second with an uncertainty of less than 0.3 K. The meter range is between -10 °C and 40 °C dew point. In the second part of the paper (section 2), two different successful applications in medicine based on fast humidity measurements have been discussed. Some specific constructions of these super fast dew point hygrometers based on a MEMS sensor as well as limited empirical results from clinical tests have been reported too.

  7. Coordinate alignment of combined measurement systems using a modified common points method

    NASA Astrophysics Data System (ADS)

    Zhao, G.; Zhang, P.; Xiao, W.

    2018-03-01

    The co-ordinate metrology has been extensively researched for its outstanding advantages in measurement range and accuracy. The alignment of different measurement systems is usually achieved by integrating local coordinates via common points before measurement. The alignment errors would accumulate and significantly reduce the global accuracy, thus need to be minimized. In this thesis, a modified common points method (MCPM) is proposed to combine different traceable system errors of the cooperating machines, and optimize the global accuracy by introducing mutual geometric constraints. The geometric constraints, obtained by measuring the common points in individual local coordinate systems, provide the possibility to reduce the local measuring uncertainty whereby enhance the global measuring certainty. A simulation system is developed in Matlab to analyze the feature of MCPM using the Monto-Carlo method. An exemplary setup is constructed to verify the feasibility and efficiency of the proposed method associated with laser tracker and indoor iGPS systems. Experimental results show that MCPM could significantly improve the alignment accuracy.

  8. Space Technology 5 Multi-point Measurements of Near-Earth Magnetic Fields: Initial Results

    NASA Technical Reports Server (NTRS)

    Slavin, James A.; Le, G.; Strangeway, R. L.; Wang, Y.; Boardsen, S.A.; Moldwin, M. B.; Spence, H. E.

    2007-01-01

    The Space Technology 5 (ST-5) mission successfully placed three micro-satellites in a 300 x 4500 km dawn-dusk orbit on 22 March 2006. Each spacecraft carried a boom-mounted vector fluxgate magnetometer that returned highly sensitive and accurate measurements of the geomagnetic field. These data allow, for the first time, the separation of temporal and spatial variations in field-aligned current (FAC) perturbations measured in low-Earth orbit on time scales of approximately 10 sec to 10 min. The constellation measurements are used to directly determine field-aligned current sheet motion, thickness and current density. In doing so, we demonstrate two multi-point methods for the inference of FAC current density that have not previously been possible in low-Earth orbit; 1) the "standard method," based upon s/c velocity, but corrected for FAC current sheet motion, and 2) the "gradiometer method" which uses simultaneous magnetic field measurements at two points with known separation. Future studies will apply these methods to the entire ST-5 data set and expand to include geomagnetic field gradient analyses as well as field-aligned and ionospheric currents.

  9. Towards semi-automatic rock mass discontinuity orientation and set analysis from 3D point clouds

    NASA Astrophysics Data System (ADS)

    Guo, Jiateng; Liu, Shanjun; Zhang, Peina; Wu, Lixin; Zhou, Wenhui; Yu, Yinan

    2017-06-01

    Obtaining accurate information on rock mass discontinuities for deformation analysis and the evaluation of rock mass stability is important. Obtaining measurements for high and steep zones with the traditional compass method is difficult. Photogrammetry, three-dimensional (3D) laser scanning and other remote sensing methods have gradually become mainstream methods. In this study, a method that is based on a 3D point cloud is proposed to semi-automatically extract rock mass structural plane information. The original data are pre-treated prior to segmentation by removing outlier points. The next step is to segment the point cloud into different point subsets. Various parameters, such as the normal, dip/direction and dip, can be calculated for each point subset after obtaining the equation of the best fit plane for the relevant point subset. A cluster analysis (a point subset that satisfies some conditions and thus forms a cluster) is performed based on the normal vectors by introducing the firefly algorithm (FA) and the fuzzy c-means (FCM) algorithm. Finally, clusters that belong to the same discontinuity sets are merged and coloured for visualization purposes. A prototype system is developed based on this method to extract the points of the rock discontinuity from a 3D point cloud. A comparison with existing software shows that this method is feasible. This method can provide a reference for rock mechanics, 3D geological modelling and other related fields.

  10. Sample size and allocation of effort in point count sampling of birds in bottomland hardwood forests

    USGS Publications Warehouse

    Smith, W.P.; Twedt, D.J.; Cooper, R.J.; Wiedenfeld, D.A.; Hamel, P.B.; Ford, R.P.; Ralph, C. John; Sauer, John R.; Droege, Sam

    1995-01-01

    To examine sample size requirements and optimum allocation of effort in point count sampling of bottomland hardwood forests, we computed minimum sample sizes from variation recorded during 82 point counts (May 7-May 16, 1992) from three localities containing three habitat types across three regions of the Mississippi Alluvial Valley (MAV). Also, we estimated the effect of increasing the number of points or visits by comparing results of 150 four-minute point counts obtained from each of four stands on Delta Experimental Forest (DEF) during May 8-May 21, 1991 and May 30-June 12, 1992. For each stand, we obtained bootstrap estimates of mean cumulative number of species each year from all possible combinations of six points and six visits. ANOVA was used to model cumulative species as a function of number of points visited, number of visits to each point, and interaction of points and visits. There was significant variation in numbers of birds and species between regions and localities (nested within region); neither habitat, nor the interaction between region and habitat, was significant. For a = 0.05 and a = 0.10, minimum sample size estimates (per factor level) varied by orders of magnitude depending upon the observed or specified range of desired detectable difference. For observed regional variation, 20 and 40 point counts were required to accommodate variability in total individuals (MSE = 9.28) and species (MSE = 3.79), respectively, whereas ? 25 percent of the mean could be achieved with five counts per factor level. Sample size sufficient to detect actual differences of Wood Thrush (Hylocichla mustelina) was >200, whereas the Prothonotary Warbler (Protonotaria citrea) required <10 counts. Differences in mean cumulative species were detected among number of points visited and among number of visits to a point. In the lower MAV, mean cumulative species increased with each added point through five points and with each additional visit through four visits

  11. Aircraft and ground vehicle friction correlation test results obtained under winter runway conditions during joint FAA/NASA Runway Friction Program

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

    1988-01-01

    Aircraft and ground vehicle friction data collected during the Joint FAA/NASA Runway Friction Program under winter runway conditions are discussed and test results are summarized. The relationship between the different ground vehicle friction measurements obtained on compacted snow- and ice-covered conditions is defined together with the correlation to aircraft tire friction performance under similar runway conditions.

  12. Structurally Caused Freezing Point Depression of Biological Tissues

    PubMed Central

    Bloch, Rene; Walters, D. H.; Kuhn, Werner

    1963-01-01

    When investigating the freezing behaviour (by thermal analysis) of the glycerol-extracted adductor muscle of Mytilus edulis it was observed that the temperature of ice formation in the muscular tissue was up to 1.5°C lower than the freezing point of the embedding liquid, a 0.25 N KCl solution with pH = 4.9 with which the tissue had been equilibrated prior to the freezing experiment. A smaller freezing point depression was observed if the pH values of the embedding 0.25 N KCl solution were above or below pH = 4.9. Reasoning from results obtained previously in analogous experiments with artificial gels, the anomalous freezing depression is explained by the impossibility of growing at the normal freezing temperature regular macroscopic crystals inside the gel, due to the presence of the gel network. The freezing temperature is here determined by the size of the microprisms penetrating the meshes of the network at the lowered freezing temperature. This process leads finally to an ice block of more or less regular structure in which the filaments are embedded. Prerequisite for this hindrance of ideal ice growth is a sufficient tensile strength of the filamental network. The existence of structurally caused freezing point depression in biological tissue is likely to invalidate many conclusions reported in the literature, in which hypertonicity was deduced from cryoscopic data. PMID:13971682

  13. Evolution of branch points for a laser beam propagating through an uplink turbulent atmosphere.

    PubMed

    Ge, Xiao-Lu; Liu, Xuan; Guo, Cheng-Shan

    2014-03-24

    Evolution of branch points in the distorted optical field is studied when a laser beam propagates through turbulent atmosphere along an uplink path. Two categories of propagation events are mainly explored for the same propagation height: fixed wavelength with change of the turbulence strength and fixed turbulence strength with change of the wavelength. It is shown that, when the beam propagates to a certain height, the density of the branch-points reaches its maximum and such a height changes with the turbulence strength but nearly remains constant with different wavelengths. The relationship between the density of branch-points and the Rytov number is also given. A fitted formula describing the relationship between the density of branch-points and propagation height with different turbulence strength and wavelength is found out. Interestingly, this formula is very similar to the formula used for describing the Blackbody radiation in physics. The results obtained may be helpful for atmospheric optics, astronomy and optical communication.

  14. Effective dynamics of a classical point charge

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Polonyi, Janos, E-mail: polonyi@iphc.cnrs.fr

    2014-03-15

    The effective Lagrangian of a point charge is derived by eliminating the electromagnetic field within the framework of the classical closed time path formalism. The short distance singularity of the electromagnetic field is regulated by an UV cutoff. The Abraham–Lorentz force is recovered and its similarity to quantum anomalies is underlined. The full cutoff-dependent linearized equation of motion is obtained, no runaway trajectories are found but the effective dynamics shows acausality if the cutoff is beyond the classical charge radius. The strength of the radiation reaction force displays a pole in its cutoff-dependence in a manner reminiscent of the Landau-polemore » of perturbative QED. Similarity between the dynamical breakdown of the time reversal invariance and dynamical symmetry breaking is pointed out. -- Highlights: •Extension of the classical action principle for dissipative systems. •New derivation of the Abraham–Lorentz force for a point charge. •Absence of a runaway solution of the Abraham–Lorentz force. •Acausality in classical electrodynamics. •Renormalization of classical electrodynamics of point charges.« less

  15. A Voxel-Based Approach for Imaging Voids in Three-Dimensional Point Clouds

    NASA Astrophysics Data System (ADS)

    Salvaggio, Katie N.

    Geographically accurate scene models have enormous potential beyond that of just simple visualizations in regard to automated scene generation. In recent years, thanks to ever increasing computational efficiencies, there has been significant growth in both the computer vision and photogrammetry communities pertaining to automatic scene reconstruction from multiple-view imagery. The result of these algorithms is a three-dimensional (3D) point cloud which can be used to derive a final model using surface reconstruction techniques. However, the fidelity of these point clouds has not been well studied, and voids often exist within the point cloud. Voids exist in texturally difficult areas, as well as areas where multiple views were not obtained during collection, constant occlusion existed due to collection angles or overlapping scene geometry, or in regions that failed to triangulate accurately. It may be possible to fill in small voids in the scene using surface reconstruction or hole-filling techniques, but this is not the case with larger more complex voids, and attempting to reconstruct them using only the knowledge of the incomplete point cloud is neither accurate nor aesthetically pleasing. A method is presented for identifying voids in point clouds by using a voxel-based approach to partition the 3D space. By using collection geometry and information derived from the point cloud, it is possible to detect unsampled voxels such that voids can be identified. This analysis takes into account the location of the camera and the 3D points themselves to capitalize on the idea of free space, such that voxels that lie on the ray between the camera and point are devoid of obstruction, as a clear line of sight is a necessary requirement for reconstruction. Using this approach, voxels are classified into three categories: occupied (contains points from the point cloud), free (rays from the camera to the point passed through the voxel), and unsampled (does not contain points

  16. Comparison of point counts and territory mapping for detecting effects of forest management on songbirds

    USGS Publications Warehouse

    Newell, Felicity L.; Sheehan, James; Wood, Petra Bohall; Rodewald, Amanda D.; Buehler, David A.; Keyser, Patrick D.; Larkin, Jeffrey L.; Beachy, Tiffany A.; Bakermans, Marja H.; Boves, Than J.; Evans, Andrea; George, Gregory A.; McDermott, Molly E.; Perkins, Kelly A.; White, Matthew; Wigley, T. Bently

    2013-01-01

    Point counts are commonly used to assess changes in bird abundance, including analytical approaches such as distance sampling that estimate density. Point-count methods have come under increasing scrutiny because effects of detection probability and field error are difficult to quantify. For seven forest songbirds, we compared fixed-radii counts (50 m and 100 m) and density estimates obtained from distance sampling to known numbers of birds determined by territory mapping. We applied point-count analytic approaches to a typical forest management question and compared results to those obtained by territory mapping. We used a before–after control impact (BACI) analysis with a data set collected across seven study areas in the central Appalachians from 2006 to 2010. Using a 50-m fixed radius, variance in error was at least 1.5 times that of the other methods, whereas a 100-m fixed radius underestimated actual density by >3 territories per 10 ha for the most abundant species. Distance sampling improved accuracy and precision compared to fixed-radius counts, although estimates were affected by birds counted outside 10-ha units. In the BACI analysis, territory mapping detected an overall treatment effect for five of the seven species, and effects were generally consistent each year. In contrast, all point-count methods failed to detect two treatment effects due to variance and error in annual estimates. Overall, our results highlight the need for adequate sample sizes to reduce variance, and skilled observers to reduce the level of error in point-count data. Ultimately, the advantages and disadvantages of different survey methods should be considered in the context of overall study design and objectives, allowing for trade-offs among effort, accuracy, and power to detect treatment effects.

  17. Cost-effectiveness of point-of-care testing for dehydration in the pediatric ED.

    PubMed

    Whitney, Rachel E; Santucci, Karen; Hsiao, Allen; Chen, Lei

    2016-08-01

    Acute gastroenteritis (AGE) and subsequent dehydration account for a large proportion of pediatric emergency department (PED) visits. Point-of-care (POC) testing has been used in conjunction with clinical assessment to determine the degree of dehydration. Despite the wide acceptance of POC testing, little formal cost-effective analysis of POC testing in the PED exists. We aim to examine the cost-effectiveness of using POC electrolyte testing vs traditional serum chemistry testing in the PED for children with AGE. This was a cost-effective analysis using data from a randomized control trial of children with AGE. A decision analysis model was constructed to calculate cost-savings from the point of view of the payer and the provider. We used parameters obtained from the trial, including cost of testing, admission rates, cost of admission, and length of stay. Sensitivity analyses were performed to evaluate the stability of our model. Using the data set of 225 subjects, POC testing results in a cost savings of $303.30 per patient compared with traditional serum testing from the point of the view of the payer. From the point-of-view of the provider, POC testing results in consistent mean savings of $36.32 ($8.29-$64.35) per patient. Sensitivity analyses demonstrated the stability of the model and consistent savings. This decision analysis provides evidence that POC testing in children with gastroenteritis-related moderate dehydration results in significant cost savings from the points of view of payers and providers compared to traditional serum chemistry testing. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. An Investigation of the Relation Between Contact Thermometry and Dew-Point Temperature Realization

    NASA Astrophysics Data System (ADS)

    Benyon, R.; Böse, N.; Mitter, H.; Mutter, D.; Vicente, T.

    2012-09-01

    Precision optical dew-point hygrometers are the most commonly used transfer standards for the comparison of dew-point temperature realizations at National Metrology Institutes (NMIs) and for disseminating traceability to calibration laboratories. These instruments have been shown to be highly reproducible when properly used. In order to obtain the best performance, the resistance of the platinum resistance thermometer (PRT) embedded in the mirror is usually measured with an external, traceable resistance bridge or digital multimeter. The relation between the conventional calibration of miniature PRTs, prior to their assembly in the mirrors of state-of-the-art optical dew-point hygrometers and their subsequent calibration as dew-point temperature measurement devices, has been investigated. Standard humidity generators of three NMIs were used to calibrate hygrometers of different designs, covering the dew-point temperature range from -75 °C to + 95 °C. The results span more than a decade, during which time successive improvements and modifications were implemented by the manufacturer. The findings are presented and discussed in the context of enabling the optimum use of these transfer standards and as a basis for determining contributions to the uncertainty in their calibration.

  19. The LANDSAT system operated in Brazil by CNPq/INPE - results obtained in the area of mapping and future perspectives

    NASA Technical Reports Server (NTRS)

    Dejesusparada, N. (Principal Investigator); Barbosa, M. N.

    1981-01-01

    The LANDSAT system, operated in the country by CNPg/INPE since 1973, systematically acquires, produces, and distributes both multispectral and panchromatic images obtained through remote sensing satellites to thousands of researchers and technicians involved in the natural resources survey. To cooperate in the solution of national problems, CNPq/INPE is developing efforts in the area of manipulation of those images with the objective of making them useful as planimetric bases for the simple revision of already published maps or for its utilization as basic material in regions not yet reliability mapped. The results obtained from performed tests are presented and the existing limitations are discussed. The new system purchased to handle data from the next series of LANDSAT as well as from MAPSAT and SPOT which will be in operation within the 80's decade, and are designed not only for natural resources survey but also for the solution of cartographic problems.

  20. Study of the composition, structure, and optical properties of a-Si{sub 1-x}C{sub x}:H Left-Pointing-Angle-Bracket Er Right-Pointing-Angle-Bracket films erbium doped from the Er(pd){sub 3} complex compound

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kudoyarova, V. Kh., E-mail: kudoyarova@mail.ioffe.ru; Tolmachev, V. A.; Gushchina, E. V.

    2013-03-15

    Rutherford backscattering, IR spectroscopy, ellipsometry, and atomic-force microscopy are used to perform an integrated study of the composition, structure and optical properties of a-Si{sub 1-x}C{sub x}:H Left-Pointing-Angle-Bracket Er Right-Pointing-Angle-Bracket amorphous films. The technique employed to obtain the a-Si{sub 1-x}C{sub x}:H Left-Pointing-Angle-Bracket Er Right-Pointing-Angle-Bracket amorphous films includes the high-frequency decomposition of a mixture of gases, (SiH{sub 4}){sub a} + (CH{sub 4}){sub b}, and the simultaneous thermal evaporation of a complex compound, Er(pd){sub 3}. It is demonstrated that raising the amount of CH{sub 4} in the gas mixture results in an increase in the carbon content of the films under study andmore » an increase in the optical gap E{sub g}{sup opt} from 1.75 to 2.2 eV. Changes in the composition of a-Si{sub 1-x}C{sub x}:H Left-Pointing-Angle-Bracket Er Right-Pointing-Angle-Bracket amorphous films, accompanied, in turn, by changes in the optical constants, are observed in the IR spectra. The ellipsometric spectra obtained are analyzed in terms of multiple-parameter models. The conclusion is made on the basis of this analysis that the experimental and calculated spectra coincide well when variation in the composition of the amorphous films with that of the gas mixture is taken into account. The existence of a thin (6-8 nm) silicon-oxide layer on the surface of the films under study and the validity of using the double-layer model in ellipsometric calculations is confirmed by the results of structural analyses by atomic-force microscopy.« less

  1. Investigating the Accuracy of Point Clouds Generated for Rock Surfaces

    NASA Astrophysics Data System (ADS)

    Seker, D. Z.; Incekara, A. H.

    2016-12-01

    Point clouds which are produced by means of different techniques are widely used to model the rocks and obtain the properties of rock surfaces like roughness, volume and area. These point clouds can be generated by applying laser scanning and close range photogrammetry techniques. Laser scanning is the most common method to produce point cloud. In this method, laser scanner device produces 3D point cloud at regular intervals. In close range photogrammetry, point cloud can be produced with the help of photographs taken in appropriate conditions depending on developing hardware and software technology. Many photogrammetric software which is open source or not currently provide the generation of point cloud support. Both methods are close to each other in terms of accuracy. Sufficient accuracy in the mm and cm range can be obtained with the help of a qualified digital camera and laser scanner. In both methods, field work is completed in less time than conventional techniques. In close range photogrammetry, any part of rock surfaces can be completely represented owing to overlapping oblique photographs. In contrast to the proximity of the data, these two methods are quite different in terms of cost. In this study, whether or not point cloud produced by photographs can be used instead of point cloud produced by laser scanner device is investigated. In accordance with this purpose, rock surfaces which have complex and irregular shape located in İstanbul Technical University Ayazaga Campus were selected as study object. Selected object is mixture of different rock types and consists of both partly weathered and fresh parts. Study was performed on a part of 30m x 10m rock surface. 2D and 3D analysis were performed for several regions selected from the point clouds of the surface models. 2D analysis is area-based and 3D analysis is volume-based. Analysis conclusions showed that point clouds in both are similar and can be used as alternative to each other. This proved that

  2. Adaptive surrogate model based multi-objective transfer trajectory optimization between different libration points

    NASA Astrophysics Data System (ADS)

    Peng, Haijun; Wang, Wei

    2016-10-01

    An adaptive surrogate model-based multi-objective optimization strategy that combines the benefits of invariant manifolds and low-thrust control toward developing a low-computational-cost transfer trajectory between libration orbits around the L1 and L2 libration points in the Sun-Earth system has been proposed in this paper. A new structure for a multi-objective transfer trajectory optimization model that divides the transfer trajectory into several segments and gives the dominations for invariant manifolds and low-thrust control in different segments has been established. To reduce the computational cost of multi-objective transfer trajectory optimization, a mixed sampling strategy-based adaptive surrogate model has been proposed. Numerical simulations show that the results obtained from the adaptive surrogate-based multi-objective optimization are in agreement with the results obtained using direct multi-objective optimization methods, and the computational workload of the adaptive surrogate-based multi-objective optimization is only approximately 10% of that of direct multi-objective optimization. Furthermore, the generating efficiency of the Pareto points of the adaptive surrogate-based multi-objective optimization is approximately 8 times that of the direct multi-objective optimization. Therefore, the proposed adaptive surrogate-based multi-objective optimization provides obvious advantages over direct multi-objective optimization methods.

  3. Space Shuttle Earth Observation sensors pointing and stabilization requirements study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The shuttle orbiter inertial measurement unit (IMU), located in the orbiter cabin, is used to supply inertial attitude reference signals; and, in conjunction with the onboard navigation system, can provide a pointing capability of the navigation base accurate to within plus or minus 0.5 deg for earth viewing missions. This pointing accuracy can degrade to approximately plus or minus 2.0 deg for payloads located in the aft bay due to structural flexure of the shuttle vehicle, payload structural and mounting misalignments, and calibration errors with respect to the navigation base. Drawbacks to obtaining pointing accuracy by using the orbiter RCS jets are discussed. Supplemental electromechanical pointing systems are developed to provide independent pointing for individual sensors, or sensor groupings. The missions considered and the sensors required for these missions and the parameters of each sensor are described. Assumptions made to derive pointing and stabilization requirements are delineated.

  4. Maximizing results for lipofilling in facial reconstruction.

    PubMed

    Barret, Juan P; Sarobe, Neus; Grande, Nelida; Vila, Delia; Palacin, Jose M

    2009-07-01

    Lipostructure (also known as structural fat grafts, lipofilling, or fat grafting) has become a technique with a good reputation and reproducible results. The application of this technology in patients undergoing reconstruction is a novel surgical alternative. Obtaining good results in this patient population is very difficult, but the application of small fat grafts with a strict Coleman technique produces long-term cosmetic effects. Adult-derived stem cells have been pointed out as important effectors of this regenerative technology, and future research should focus in this direction.

  5. Automatic extraction of pavement markings on streets from point cloud data of mobile LiDAR

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Zhong, Ruofei; Tang, Tao; Wang, Liuzhao; Liu, Xianlin

    2017-08-01

    Pavement markings provide an important foundation as they help to keep roads users safe. Accurate and comprehensive information about pavement markings assists the road regulators and is useful in developing driverless technology. Mobile light detection and ranging (LiDAR) systems offer new opportunities to collect and process accurate pavement markings’ information. Mobile LiDAR systems can directly obtain the three-dimensional (3D) coordinates of an object, thus defining spatial data and the intensity of (3D) objects in a fast and efficient way. The RGB attribute information of data points can be obtained based on the panoramic camera in the system. In this paper, we present a novel method process to automatically extract pavement markings using multiple attribute information of the laser scanning point cloud from the mobile LiDAR data. This method process utilizes a differential grayscale of RGB color, laser pulse reflection intensity, and the differential intensity to identify and extract pavement markings. We utilized point cloud density to remove the noise and used morphological operations to eliminate the errors. In the application, we tested our method process on different sections of roads in Beijing, China, and Buffalo, NY, USA. The results indicated that both correctness (p) and completeness (r) were higher than 90%. The method process of this research can be applied to extract pavement markings from huge point cloud data produced by mobile LiDAR.

  6. A novel point cloud registration using 2D image features

    NASA Astrophysics Data System (ADS)

    Lin, Chien-Chou; Tai, Yen-Chou; Lee, Jhong-Jin; Chen, Yong-Sheng

    2017-01-01

    Since a 3D scanner only captures a scene of a 3D object at a time, a 3D registration for multi-scene is the key issue of 3D modeling. This paper presents a novel and an efficient 3D registration method based on 2D local feature matching. The proposed method transforms the point clouds into 2D bearing angle images and then uses the 2D feature based matching method, SURF, to find matching pixel pairs between two images. The corresponding points of 3D point clouds can be obtained by those pixel pairs. Since the corresponding pairs are sorted by their distance between matching features, only the top half of the corresponding pairs are used to find the optimal rotation matrix by the least squares approximation. In this paper, the optimal rotation matrix is derived by orthogonal Procrustes method (SVD-based approach). Therefore, the 3D model of an object can be reconstructed by aligning those point clouds with the optimal transformation matrix. Experimental results show that the accuracy of the proposed method is close to the ICP, but the computation cost is reduced significantly. The performance is six times faster than the generalized-ICP algorithm. Furthermore, while the ICP requires high alignment similarity of two scenes, the proposed method is robust to a larger difference of viewing angle.

  7. Beyond Clausius-Mossotti - Wave propagation on a polarizable point lattice and the discrete dipole approximation. [electromagnetic scattering and absorption by interstellar grains

    NASA Technical Reports Server (NTRS)

    Draine, B. T.; Goodman, Jeremy

    1993-01-01

    We derive the dispersion relation for electromagnetic waves propagating on a lattice of polarizable points. From this dispersion relation we obtain a prescription for choosing dipole polarizabilities so that an infinite lattice with finite lattice spacing will mimic a continuum with dielectric constant. The discrete dipole approximation is used to calculate scattering and absorption by a finite target by replacing the target with an array of point dipoles. We compare different prescriptions for determining the dipole polarizabilities. We show that the most accurate results are obtained when the lattice dispersion relation is used to set the polarizabilities.

  8. 100-point scale evaluating job satisfaction and the results of the 12-item General Health Questionnaire in occupational workers.

    PubMed

    Kawada, Tomoyuki; Yamada, Natsuki

    2012-01-01

    Job satisfaction is an important factor in the occupational lives of workers. In this study, the relationship between one-dimensional scale of job satisfaction and psychological wellbeing was evaluated. A total of 1,742 workers (1,191 men and 551 women) participated. 100-point scale evaluating job satisfaction (0 [extremely dissatisfied] to 100 [extremely satisfied]) and the General Health Questionnaire, 12-item version (GHQ-12) evaluating psychological wellbeing were used. A multiple regression analysis was then used, controlling for gender and age. The change in the GHQ-12 and job satisfaction scores after a two-year interval was also evaluated. The mean age for the subjects was 42.2 years for the men and 36.2 years for the women. The GHQ-12 and job satisfaction scores were significantly correlated in each generation. The partial correlation coefficients between the changes in the two variables, controlling for age, were -0.395 for men and -0.435 for women (p< 0.001). A multiple regression analysis revealed that the 100-point job satisfaction score was associated with the GHQ-12 results (p< 0.001). The adjusted multiple correlation coefficient was 0.275. The 100-point scale, which is a simple and easy tool for evaluating job satisfaction, was significantly associated with psychological wellbeing as judged using the GHQ-12.

  9. Results of in vivo measurements of strontium-90 body-burden in Urals residents: analyses of data obtained 2006-2012

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tolstykh, E. I.; Bougrov, N. G.; Krivoshchapov, Victor A.

    2012-06-01

    A part of the Urals territory was contaminated with 90Sr and 137Cs in the 1950s as a result of accidents at the "Mayak" Production Association. The paper describes the analysis of in vivo 90Sr measurements in Urals residents. The measurements were performed with the use of whole-body-counter SICH-9.1M in 2006-2012. Totally 5840 measurements for 4876 persons were performed from 2006 to 2012; maximal measured value was 24 kBq. Earlier, similar measurements were performed with SICH-9.1 (1974-1997). Comparison of the results obtained with SICH-9.1 and SICH-9.1M has shown a good agreement of the two data sets.

  10. Development of Point Doppler Velocimetry for Flow Field Investigations

    NASA Technical Reports Server (NTRS)

    Cavone, Angelo A.; Meyers, James F.; Lee, Joseph W.

    2006-01-01

    A Point Doppler Velocimeter (pDv) has been developed using a vapor-limited iodine cell as the sensing medium. The iodine cell is utilized to directly measure the Doppler shift frequency of laser light scattered from submicron particles suspended within a fluid flow. The measured Doppler shift can then be used to compute the velocity of the particles, and hence the fluid. Since this approach does not require resolution of scattered light from individual particles, the potential exists to obtain temporally continuous signals that could be uniformly sampled in the manner as a hot wire anemometer. This leads to the possibility of obtaining flow turbulence power spectra without the limitations of fringe-type laser velocimetry. The development program consisted of a methodical investigation of the technology coupled with the solution of practical engineering problems to produce a usable measurement system. The paper outlines this development along with the evaluation of the resulting system as compared to primary standards and other measurement technologies.

  11. Automated realization of the gallium melting and triple points

    NASA Astrophysics Data System (ADS)

    Yan, X.; Duan, Y.; Zhang, J. T.; Wang, W.

    2013-09-01

    In order to improve the automation and convenience of the process involved in realizing the gallium fixed points, an automated apparatus, based on thermoelectric and heat pipe technologies, was designed and developed. This paper describes the apparatus design and procedures for freezing gallium mantles and realizing gallium melting and triple points. Also, investigations on the melting behavior of a gallium melting point cell and of gallium triple point cells were carried out while controlling the temperature outside the gallium point cells at 30 °C, 30.5 °C, 31 °C, and 31.5 °C. The obtained melting plateau curves show dentate temperature oscillations on the melting plateaus for the gallium point cells when thermal couplings occurred between the outer and inner liquid-solid interfaces. The maximum amplitude of the temperature fluctuations was about 1.5 mK. Therefore, the temperature oscillations can be used to indicate the ending of the equilibrium phase transitions. The duration and amplitude of such temperature oscillations depend on the temperature difference between the setting temperature and the gallium point temperature; the smaller the temperature difference, the longer the duration of both the melting plateaus and the temperature fluctuations.

  12. Design and Evaluation of Large-Aperture Gallium Fixed-Point Blackbody

    NASA Astrophysics Data System (ADS)

    Khromchenko, V. B.; Mekhontsev, S. N.; Hanssen, L. M.

    2009-02-01

    To complement existing water bath blackbodies that now serve as NIST primary standard sources in the temperature range from 15 °C to 75 °C, a gallium fixed-point blackbody has been recently built. The main objectives of the project included creating an extended-area radiation source with a target emissivity of 0.9999 capable of operating either inside a cryo-vacuum chamber or in a standard laboratory environment. A minimum aperture diameter of 45 mm is necessary for the calibration of radiometers with a collimated input geometry or large spot size. This article describes the design and performance evaluation of the gallium fixed-point blackbody, including the calculation and measurements of directional effective emissivity, estimates of uncertainty due to the temperature drop across the interface between the pure metal and radiating surfaces, as well as the radiometrically obtained spatial uniformity of the radiance temperature and the melting plateau stability. Another important test is the measurement of the cavity reflectance, which was achieved by using total integrated scatter measurements at a laser wavelength of 10.6 μm. The result allows one to predict the performance under the low-background conditions of a cryo-chamber. Finally, results of the spectral radiance comparison with the NIST water-bath blackbody are provided. The experimental results are in good agreement with predicted values and demonstrate the potential of our approach. It is anticipated that, after completion of the characterization, a similar source operating at the water triple point will be constructed.

  13. First-principles study of point defects in thorium carbide

    NASA Astrophysics Data System (ADS)

    Pérez Daroca, D.; Jaroszewicz, S.; Llois, A. M.; Mosca, H. O.

    2014-11-01

    Thorium-based materials are currently being investigated in relation with their potential utilization in Generation-IV reactors as nuclear fuels. One of the most important issues to be studied is their behavior under irradiation. A first approach to this goal is the study of point defects. By means of first-principles calculations within the framework of density functional theory, we study the stability and formation energies of vacancies, interstitials and Frenkel pairs in thorium carbide. We find that C isolated vacancies are the most likely defects, while C interstitials are energetically favored as compared to Th ones. These kind of results for ThC, to the best authors' knowledge, have not been obtained previously, neither experimentally, nor theoretically. For this reason, we compare with results on other compounds with the same NaCl-type structure.

  14. Stagnation-point heat transfer correlation for ionized gases

    NASA Technical Reports Server (NTRS)

    Bade, W. L.

    1975-01-01

    Based on previous laminar boundary-layer solutions for argon, xenon, nitrogen, and air, it is shown that the effect of gas ionization on stagnation-point heat transfer can be correlated with the variation of the frozen Prandtl number across the boundary layer. A formula is obtained for stagnation-point heat transfer in a noble gas and is shown to be valid from the low-temperature range to the region of strong ionization. It is concluded that the considered effect can be well correlated by the 0.7 power of the Prandtl-number ratio across the boundary layer.

  15. Standard map in magnetized relativistic systems: fixed points and regular acceleration.

    PubMed

    de Sousa, M C; Steffens, F M; Pakter, R; Rizzato, F B

    2010-08-01

    We investigate the concept of a standard map for the interaction of relativistic particles and electrostatic waves of arbitrary amplitudes, under the action of external magnetic fields. The map is adequate for physical settings where waves and particles interact impulsively, and allows for a series of analytical result to be exactly obtained. Unlike the traditional form of the standard map, the present map is nonlinear in the wave amplitude and displays a series of peculiar properties. Among these properties we discuss the relation involving fixed points of the maps and accelerator regimes.

  16. Multistate Landau-Zener models with all levels crossing at one point

    DOE PAGES

    Li, Fuxiang; Sun, Chen; Chernyak, Vladimir Y.; ...

    2017-08-04

    Within this paper, we discuss common properties and reasons for integrability in the class of multistate Landau-Zener models with all diabatic levels crossing at one point. Exploring the Stokes phenomenon, we show that each previously solved model has a dual one, whose scattering matrix can be also obtained analytically. For applications, we demonstrate how our results can be used to study conversion of molecular into atomic Bose condensates during passage through the Feshbach resonance, and provide purely algebraic solutions of the bowtie and special cases of the driven Tavis-Cummings model.

  17. Two-Point Orientation Discrimination Versus the Traditional Two-Point Test for Tactile Spatial Acuity Assessment

    PubMed Central

    Tong, Jonathan; Mao, Oliver; Goldreich, Daniel

    2013-01-01

    Two-point discrimination is widely used to measure tactile spatial acuity. The validity of the two-point threshold as a spatial acuity measure rests on the assumption that two points can be distinguished from one only when the two points are sufficiently separated to evoke spatially distinguishable foci of neural activity. However, some previous research has challenged this view, suggesting instead that two-point task performance benefits from an unintended non-spatial cue, allowing spuriously good performance at small tip separations. We compared the traditional two-point task to an equally convenient alternative task in which participants attempt to discern the orientation (vertical or horizontal) of two points of contact. We used precision digital readout calipers to administer two-interval forced-choice versions of both tasks to 24 neurologically healthy adults, on the fingertip, finger base, palm, and forearm. We used Bayesian adaptive testing to estimate the participants’ psychometric functions on the two tasks. Traditional two-point performance remained significantly above chance levels even at zero point separation. In contrast, two-point orientation discrimination approached chance as point separation approached zero, as expected for a valid measure of tactile spatial acuity. Traditional two-point performance was so inflated at small point separations that 75%-correct thresholds could be determined on all tested sites for fewer than half of participants. The 95%-correct thresholds on the two tasks were similar, and correlated with receptive field spacing. In keeping with previous critiques, we conclude that the traditional two-point task provides an unintended non-spatial cue, resulting in spuriously good performance at small spatial separations. Unlike two-point discrimination, two-point orientation discrimination rigorously measures tactile spatial acuity. We recommend the use of two-point orientation discrimination for neurological assessment. PMID

  18. Multi-scale silica structures for improved point of care detection

    NASA Astrophysics Data System (ADS)

    Lin, Sophia; Lin, Lancy; Cho, Eunbyul; Pezzani, Gaston A. O.; Khine, Michelle

    2017-03-01

    The need for sensitive, portable diagnostic tests at the point of care persists. We report on a simple method to obtain improved detection of biomolecules by a two-fold mechanism. Silica (SiO2) is coated on pre-stressed thermoplastic shrink-wrap film. When the film retracts, the resulting micro- and nanostructures yield far-field fluorescence signal enhancements over their planar or wrinkled counterparts. Because the film shrinks by 95% in surface area, there is also a 20x concentration effect. The SiO2 structured substrate is therefore used for improved detection of labeled proteins and DNA hybridization via both fluorescent and bright field. Through optical characterization studies, we attribute the fluorescence signal enhancements of 100x to increased surface density and light scattering from the rough SiO2 structures. Combining with our open channel self-wicking microfluidics, we can achieve extremely low cost yet sensitive point of care diagnostics.

  19. Localized saddle-point search and application to temperature-accelerated dynamics

    NASA Astrophysics Data System (ADS)

    Shim, Yunsic; Callahan, Nathan B.; Amar, Jacques G.

    2013-03-01

    We present a method for speeding up temperature-accelerated dynamics (TAD) simulations by carrying out a localized saddle-point (LSAD) search. In this method, instead of using the entire system to determine the energy barriers of activated processes, the calculation is localized by only including a small chunk of atoms around the atoms directly involved in the transition. Using this method, we have obtained N-independent scaling for the computational cost of the saddle-point search as a function of system size N. The error arising from localization is analyzed using a variety of model systems, including a variety of activated processes on Ag(100) and Cu(100) surfaces, as well as multiatom moves in Cu radiation damage and metal heteroepitaxial growth. Our results show significantly improved performance of TAD with the LSAD method, for the case of Ag/Ag(100) annealing and Cu/Cu(100) growth, while maintaining a negligibly small error in energy barriers.

  20. THE CHANDRA COSMOS SURVEY. I. OVERVIEW AND POINT SOURCE CATALOG

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Elvis, Martin; Civano, Francesca; Aldcroft, T. L.

    2009-09-01

    The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra program that has imaged the central 0.5 deg{sup 2} of the COSMOS field (centered at 10 {sup h}, +02 deg.) with an effective exposure of {approx}160 ks, and an outer 0.4 deg{sup 2} area with an effective exposure of {approx}80 ks. The limiting source detection depths are 1.9 x 10{sup -16} erg cm{sup -2} s{sup -1} in the soft (0.5-2 keV) band, 7.3 x 10{sup -16} erg cm{sup -2} s{sup -1} in the hard (2-10 keV) band, and 5.7 x 10{sup -16} erg cm{sup -2} s{sup -1} in themore » full (0.5-10 keV) band. Here we describe the strategy, design, and execution of the C-COSMOS survey, and present the catalog of 1761 point sources detected at a probability of being spurious of <2 x 10{sup -5} (1655 in the full, 1340 in the soft, and 1017 in the hard bands). By using a grid of 36 heavily ({approx}50%) overlapping pointing positions with the ACIS-I imager, a remarkably uniform ({+-}12%) exposure across the inner 0.5 deg{sup 2} field was obtained, leading to a sharply defined lower flux limit. The widely different point-spread functions obtained in each exposure at each point in the field required a novel source detection method, because of the overlapping tiling strategy, which is described in a companion paper. This method produced reliable sources down to a 7-12 counts, as verified by the resulting logN-logS curve, with subarcsecond positions, enabling optical and infrared identifications of virtually all sources, as reported in a second companion paper. The full catalog is described here in detail and is available online.« less

  1. Analysis of point source size on measurement accuracy of lateral point-spread function of confocal Raman microscopy

    NASA Astrophysics Data System (ADS)

    Fu, Shihang; Zhang, Li; Hu, Yao; Ding, Xiang

    2018-01-01

    Confocal Raman Microscopy (CRM) has matured to become one of the most powerful instruments in analytical science because of its molecular sensitivity and high spatial resolution. Compared with conventional Raman Microscopy, CRM can perform three dimensions mapping of tiny samples and has the advantage of high spatial resolution thanking to the unique pinhole. With the wide application of the instrument, there is a growing requirement for the evaluation of the imaging performance of the system. Point-spread function (PSF) is an important approach to the evaluation of imaging capability of an optical instrument. Among a variety of measurement methods of PSF, the point source method has been widely used because it is easy to operate and the measurement results are approximate to the true PSF. In the point source method, the point source size has a significant impact on the final measurement accuracy. In this paper, the influence of the point source sizes on the measurement accuracy of PSF is analyzed and verified experimentally. A theoretical model of the lateral PSF for CRM is established and the effect of point source size on full-width at half maximum of lateral PSF is simulated. For long-term preservation and measurement convenience, PSF measurement phantom using polydimethylsiloxane resin, doped with different sizes of polystyrene microspheres is designed. The PSF of CRM with different sizes of microspheres are measured and the results are compared with the simulation results. The results provide a guide for measuring the PSF of the CRM.

  2. Optimization of the thermogauge furnace for realizing high temperature fixed points

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, T.; Dong, W.; Liu, F.

    2013-09-11

    The thermogauge furnace was commonly used in many NMIs as a blackbody source for calibration of the radiation thermometer. It can also be used for realizing the high temperature fixed point(HTFP). According to our experience, when realizing HTFP we need the furnace provide relative good temperature uniformity to avoid the possible damage to the HTFP. To improve temperature uniformity in the furnace, the furnace tube was machined near the tube ends with a help of a simulation analysis by 'ansys workbench'. Temperature distributions before and after optimization were measured and compared at 1300 °C, 1700°C, 2500 °C, which roughly correspondmore » to Co-C(1324 °C), Pt-C(1738 °C) and Re-C(2474 °C), respectively. The results clearly indicate that through machining the tube the temperature uniformity of the Thermogage furnace can be remarkably improved. A Pt-C high temperature fixed point was realized in the modified Thermogauge furnace subsequently, the plateaus were compared with what obtained using old heater, and the results were presented in this paper.« less

  3. Seeking fixed points in multiple coupling scalar theories in the ɛ expansion

    NASA Astrophysics Data System (ADS)

    Osborn, Hugh; Stergiou, Andreas

    2018-05-01

    Fixed points for scalar theories in 4 - ɛ, 6 - ɛ and 3 - ɛ dimensions are discussed. It is shown how a large range of known fixed points for the four dimensional case can be obtained by using a general framework with two couplings. The original maximal symmetry, O( N), is broken to various subgroups, both discrete and continuous. A similar discussion is applied to the six dimensional case. Perturbative applications of the a-theorem are used to help classify potential fixed points. At lowest order in the ɛ-expansion it is shown that at fixed points there is a lower bound for a which is saturated at bifurcation points.

  4. Digital controller design: Analysis of the annular suspension pointing system

    NASA Technical Reports Server (NTRS)

    Kuo, B. C.

    1979-01-01

    The Annular Suspension and Pointing System (ASPS) is a payload auxiliary pointing device of the Space Shuttle. The ASPS is comprised of two major subassemblies, a vernier and a coarse pointing subsystem. The experiment is attached to a mounting plate/rim combination which is suspended on magnetic bearing/actuators (MBA) strategically located about the rim. Fine pointing is achieved by gimballing the plate/rim within the MBA gaps. Control about the experiment line-of-sight is obtained through the use of a non-contacting rim drive and positioning torquer. All sensors used to close the servo loops on the vernier system are noncontacting elements. Therefore, the experiment is a free-flyer constrained only by the magnetic forces generated by the control loops.

  5. Midterm results of "thrust plate" prosthesis.

    PubMed

    Fink, Bernd; Wessel, Stephanie; Deuretzbacher, Georg; Protzen, Michael; Ruther, Wolfgang

    2007-08-01

    The aim of this investigation was to analyze the midterm results obtained with the metaphyseal fixation principle of the thrust plate prosthesis (TPP). Survival of 214 implants in 204 patients was analyzed. Clinical (Harris hip score) and radiologic examinations were carried out on 157 of 190 TPP with a postimplantation follow-up period of at least 5 years. Failure rate was 7.0% (9 aseptic and 6 septic loosening). Harris hip score increased from 36.9 +/- 13.5 points preoperatively to 91.2 +/- 13.1 points at follow-up. Eleven TPPs showed radiolucent lines not indicating prosthetic loosening. Thrust plate prosthesis is not an alternative to stemmed endoprostheses. It may be rarely indicated in very young patients where, because of their age, several revision operations can be expected.

  6. Water Triple-Point Comparisons: Plateau Averaging or Peak Value?

    NASA Astrophysics Data System (ADS)

    Steur, P. P. M.; Dematteis, R.

    2014-04-01

    With a certain regularity, national metrology institutes conduct comparisons of water triple-point (WTP) cells. The WTP is the most important fixed point for the International Temperature Scale of 1990 (ITS-90). In such comparisons, it is common practice to simply average all the single measured temperature points obtained on a single ice mantle. This practice is quite reasonable whenever the measurements show no time dependence in the results. Ever since the first Supplementary Information for the International Temperature Scale of 1990, published by the Bureau International des Poids et Mesures in Sèvres, it was strongly suggested to wait at least 1 day before taking measurements (now up to 10 days), in order for a newly created ice mantle to stabilize. This stabilization is accompanied by a change in temperature with time. A recent improvement in the sensitivity of resistance measurement enabled the Istituto Nazionale di Ricerca Metrologica to detect more clearly the (possible) change in temperature with time of the WTP on a single ice mantle, as for old borosilicate cells. A limited investigation was performed where the temperature of two cells was monitored day-by-day, from the moment of mantle creation, where it was found that with (old) borosilicate cells it may be counterproductive to wait the usual week before starting measurements. The results are presented and discussed, and it is suggested to adapt the standard procedure for comparisons of WTP cells allowing for a different data treatment with (old) borosilicate cells, because taking the temperature dependence into account will surely reduce the reported differences between cells.

  7. Multiple window spatial registration error of a gamma camera: 133Ba point source as a replacement of the NEMA procedure.

    PubMed

    Bergmann, Helmar; Minear, Gregory; Raith, Maria; Schaffarich, Peter M

    2008-12-09

    The accuracy of multiple window spatial resolution characterises the performance of a gamma camera for dual isotope imaging. In the present study we investigate an alternative method to the standard NEMA procedure for measuring this performance parameter. A long-lived 133Ba point source with gamma energies close to 67Ga and a single bore lead collimator were used to measure the multiple window spatial registration error. Calculation of the positions of the point source in the images used the NEMA algorithm. The results were validated against the values obtained by the standard NEMA procedure which uses a liquid 67Ga source with collimation. Of the source-collimator configurations under investigation an optimum collimator geometry, consisting of a 5 mm thick lead disk with a diameter of 46 mm and a 5 mm central bore, was selected. The multiple window spatial registration errors obtained by the 133Ba method showed excellent reproducibility (standard deviation < 0.07 mm). The values were compared with the results from the NEMA procedure obtained at the same locations and showed small differences with a correlation coefficient of 0.51 (p < 0.05). In addition, the 133Ba point source method proved to be much easier to use. A Bland-Altman analysis showed that the 133Ba and the 67Ga Method can be used interchangeably. The 133Ba point source method measures the multiple window spatial registration error with essentially the same accuracy as the NEMA-recommended procedure, but is easier and safer to use and has the potential to replace the current standard procedure.

  8. Preliminary Design and Analysis of the GIFTS Instrument Pointing System

    NASA Technical Reports Server (NTRS)

    Zomkowski, Paul P.

    2003-01-01

    The Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) Instrument is the next generation spectrometer for remote sensing weather satellites. The GIFTS instrument will be used to perform scans of the Earth s atmosphere by assembling a series of field-of- views (FOV) into a larger pattern. Realization of this process is achieved by step scanning the instrument FOV in a contiguous fashion across any desired portion of the visible Earth. A 2.3 arc second pointing stability, with respect to the scanning instrument, must be maintained for the duration of the FOV scan. A star tracker producing attitude data at 100 Hz rate will be used by the autonomous pointing algorithm to precisely track target FOV s on the surface of the Earth. The main objective is to validate the pointing algorithm in the presence of spacecraft disturbances and determine acceptable disturbance limits from expected noise sources. Proof of concept validation of the pointing system algorithm is carried out with a full system simulation developed using Matlab Simulink. Models for the following components function within the full system simulation: inertial reference unit (IRU), attitude control system (ACS), reaction wheels, star tracker, and mirror controller. With the spacecraft orbital position and attitude maintained to within specified limits the pointing algorithm receives quaternion, ephemeris, and initialization data that are used to construct the required mirror pointing commands at a 100 Hz rate. This comprehensive simulation will also aid in obtaining a thorough understanding of spacecraft disturbances and other sources of pointing system errors. Parameter sensitivity studies and disturbance analysis will be used to obtain limits of operability for the GIFTS instrument. The culmination of this simulation development and analysis will be used to validate the specified performance requirements outlined for this instrument.

  9. Development of method for experimental determination of wheel-rail contact forces and contact point position by using instrumented wheelset

    NASA Astrophysics Data System (ADS)

    Bižić, Milan B.; Petrović, Dragan Z.; Tomić, Miloš C.; Djinović, Zoran V.

    2017-07-01

    This paper presents the development of a unique method for experimental determination of wheel-rail contact forces and contact point position by using the instrumented wheelset (IWS). Solutions of key problems in the development of IWS are proposed, such as the determination of optimal locations, layout, number and way of connecting strain gauges as well as the development of an inverse identification algorithm (IIA). The base for the solution of these problems is the wheel model and results of FEM calculations, while IIA is based on the method of blind source separation using independent component analysis. In the first phase, the developed method was tested on a wheel model and a high accuracy was obtained (deviations of parameters obtained with IIA and really applied parameters in the model are less than 2%). In the second phase, experimental tests on the real object or IWS were carried out. The signal-to-noise ratio was identified as the main influential parameter on the measurement accuracy. Тhе obtained results have shown that the developed method enables measurement of vertical and lateral wheel-rail contact forces Q and Y and their ratio Y/Q with estimated errors of less than 10%, while the estimated measurement error of contact point position is less than 15%. At flange contact and higher values of ratio Y/Q or Y force, the measurement errors are reduced, which is extremely important for the reliability and quality of experimental tests of safety against derailment of railway vehicles according to the standards UIC 518 and EN 14363. The obtained results have shown that the proposed method can be successfully applied in solving the problem of high accuracy measurement of wheel-rail contact forces and contact point position using IWS.

  10. Dependence of the pour point of diesel fuels on the properties of the initial components

    NASA Technical Reports Server (NTRS)

    Ostashov, V. M.; Bobrovskiy, S. A.

    1979-01-01

    An analytical expression is obtained for the dependence of the pour point of diesel fuels on the pour point and weight relationship of the initial components. For determining the pour point of a multicomponent fuel mixture, it is assumed that the mixture of two components has the pour point of a separate equivalent component, then calculating the pour point of this equivalent component mixed with a third component, etc.

  11. Comparisons of nanoindentation, 3-point bending, and tension tests for orthodontic wires.

    PubMed

    Iijima, Masahiro; Muguruma, Takeshi; Brantley, William A; Mizoguchi, Itaru

    2011-07-01

    The purposes of this study were to obtain information about mechanical properties with the nanoindentation test for representative wire alloys and compare the results with conventional mechanical tests. Archwires having 0.016 × 0.022-in cross sections were obtained of 1 stainless steel, 1 cobalt-chromium-nickel, 1 beta-titanium alloy, and 2 nickel-titanium products. Specimens of as-received wires were subjected to nanoindentation testing along the external surfaces and over polished cross sections to obtain values of hardness and elastic modulus. Other specimens of as-received wires were subjected to Vickers hardness, 3-point bending, and tension tests. All testing was performed at 25°C. Differences were found in hardness and elastic modulus obtained with the nanoindentation test at the external and cross-sectioned surfaces and with the conventional mechanical-property tests. Mechanical properties obtained with the nanoindentation test generally varied with indentation depth. The 3 testing methods did not yield identical values of hardness and elastic modulus, although the order among the 5 wire products was the same. Variations in results for the nanoindentation and conventional mechanical property tests can be attributed to the different material volumes sampled, different work-hardening levels, and an oxide layer on the wire surface. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  12. Solubilization of phenanthrene above cloud point of Brij 30: a new application in biodegradation.

    PubMed

    Pantsyrnaya, T; Delaunay, S; Goergen, J L; Guseva, E; Boudrant, J

    2013-06-01

    In the present study a new application of solubilization of phenanthrene above cloud point of Brij 30 in biodegradation was developed. It was shown that a temporal solubilization of phenanthrene above cloud point of Brij 30 (5wt%) permitted to obtain a stable increase of the solubility of phenanthrene even when the temperature was decreased to culture conditions of used microorganism Pseudomonas putida (28°C). A higher initial concentration of soluble phenanthrene was obtained after the cloud point treatment: 200 against 120μM without treatment. All soluble phenanthrene was metabolized and a higher final concentration of its major metabolite - 1-hydroxy-2-naphthoic acid - (160 against 85μM) was measured in the culture medium in the case of a preliminary cloud point treatment. Therefore a temporary solubilization at cloud point might have a perspective application in the enhancement of biodegradation of polycyclic aromatic hydrocarbons. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Multidirectional hybrid algorithm for the split common fixed point problem and application to the split common null point problem.

    PubMed

    Li, Xia; Guo, Meifang; Su, Yongfu

    2016-01-01

    In this article, a new multidirectional monotone hybrid iteration algorithm for finding a solution to the split common fixed point problem is presented for two countable families of quasi-nonexpansive mappings in Banach spaces. Strong convergence theorems are proved. The application of the result is to consider the split common null point problem of maximal monotone operators in Banach spaces. Strong convergence theorems for finding a solution of the split common null point problem are derived. This iteration algorithm can accelerate the convergence speed of iterative sequence. The results of this paper improve and extend the recent results of Takahashi and Yao (Fixed Point Theory Appl 2015:87, 2015) and many others .

  14. Monitoring of dispersed smoke-plume layers by determining locations of the data-point clusters

    NASA Astrophysics Data System (ADS)

    Kovalev, Vladimir; Wold, Cyle; Petkov, Alexander; Min Hao, Wei

    2018-04-01

    A modified data-processing technique of the signals recorded by zenith-directed lidar, which operates in smoke-polluted atmosphere, is discussed. The technique is based on simple transformations of the lidar backscatter signal and the determination of the spatial location of the data point clusters. The technique allows more reliable detection of the location of dispersed smoke layering. Examples of typical results obtained with lidar in a smokepolluted atmosphere are presented.

  15. Seeing Your Error Alters My Pointing: Observing Systematic Pointing Errors Induces Sensori-Motor After-Effects

    PubMed Central

    Ronchi, Roberta; Revol, Patrice; Katayama, Masahiro; Rossetti, Yves; Farnè, Alessandro

    2011-01-01

    During the procedure of prism adaptation, subjects execute pointing movements to visual targets under a lateral optical displacement: As consequence of the discrepancy between visual and proprioceptive inputs, their visuo-motor activity is characterized by pointing errors. The perception of such final errors triggers error-correction processes that eventually result into sensori-motor compensation, opposite to the prismatic displacement (i.e., after-effects). Here we tested whether the mere observation of erroneous pointing movements, similar to those executed during prism adaptation, is sufficient to produce adaptation-like after-effects. Neurotypical participants observed, from a first-person perspective, the examiner's arm making incorrect pointing movements that systematically overshot visual targets location to the right, thus simulating a rightward optical deviation. Three classical after-effect measures (proprioceptive, visual and visual-proprioceptive shift) were recorded before and after first-person's perspective observation of pointing errors. Results showed that mere visual exposure to an arm that systematically points on the right-side of a target (i.e., without error correction) produces a leftward after-effect, which mostly affects the observer's proprioceptive estimation of her body midline. In addition, being exposed to such a constant visual error induced in the observer the illusion “to feel” the seen movement. These findings indicate that it is possible to elicit sensori-motor after-effects by mere observation of movement errors. PMID:21731649

  16. An Instantaneous Low-Cost Point-of-Care Anemia Detection Device

    PubMed Central

    Punter-Villagrasa, Jaime; Cid, Joan; Páez-Avilés, Cristina; Rodríguez-Villarreal, Ivón; Juanola-Feliu, Esteve; Colomer-Farrarons, Jordi; Miribel-Català, Pere Ll.

    2015-01-01

    We present a small, compact and portable device for point-of-care instantaneous early detection of anemia. The method used is based on direct hematocrit measurement from whole blood samples by means of impedance analysis. This device consists of a custom electronic instrumentation and a plug-and-play disposable sensor. The designed electronics rely on straightforward standards for low power consumption, resulting in a robust and low consumption device making it completely mobile with a long battery life. Another approach could be powering the system based on other solutions like indoor solar cells, or applying energy-harvesting solutions in order to remove the batteries. The sensing system is based on a disposable low-cost label-free three gold electrode commercial sensor for 50 μL blood samples. The device capability for anemia detection has been validated through 24 blood samples, obtained from four hospitalized patients at Hospital Clínic. As a result, the response, effectiveness and robustness of the portable point-of-care device to detect anemia has been proved with an accuracy error of 2.83% and a mean coefficient of variation of 2.57% without any particular case above 5%. PMID:25690552

  17. The goal of ape pointing

    PubMed Central

    Liebal, Katja; Tomasello, Michael

    2018-01-01

    Captive great apes regularly use pointing gestures in their interactions with humans. However, the precise function of this gesture is unknown. One possibility is that apes use pointing primarily to direct attention (as in “please look at that”); another is that they point mainly as an action request (such as “can you give that to me?”). We investigated these two possibilities here by examining how the looking behavior of recipients affects pointing in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). Upon pointing to food, subjects were faced with a recipient who either looked at the indicated object (successful-look) or failed to look at the indicated object (failed-look). We predicted that, if apes point primarily to direct attention, subjects would spend more time pointing in the failed-look condition because the goal of their gesture had not been met. Alternatively, we expected that, if apes point primarily to request an object, subjects would not differ in their pointing behavior between the successful-look and failed-look conditions because these conditions differed only in the looking behavior of the recipient. We found that subjects did differ in their pointing behavior across the successful-look and failed-look conditions, but contrary to our prediction subjects spent more time pointing in the successful-look condition. These results suggest that apes are sensitive to the attentional states of gestural recipients, but their adjustments are aimed at multiple goals. We also found a greater number of individuals with a strong right-hand than left-hand preference for pointing. PMID:29694358

  18. The goal of ape pointing.

    PubMed

    Halina, Marta; Liebal, Katja; Tomasello, Michael

    2018-01-01

    Captive great apes regularly use pointing gestures in their interactions with humans. However, the precise function of this gesture is unknown. One possibility is that apes use pointing primarily to direct attention (as in "please look at that"); another is that they point mainly as an action request (such as "can you give that to me?"). We investigated these two possibilities here by examining how the looking behavior of recipients affects pointing in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). Upon pointing to food, subjects were faced with a recipient who either looked at the indicated object (successful-look) or failed to look at the indicated object (failed-look). We predicted that, if apes point primarily to direct attention, subjects would spend more time pointing in the failed-look condition because the goal of their gesture had not been met. Alternatively, we expected that, if apes point primarily to request an object, subjects would not differ in their pointing behavior between the successful-look and failed-look conditions because these conditions differed only in the looking behavior of the recipient. We found that subjects did differ in their pointing behavior across the successful-look and failed-look conditions, but contrary to our prediction subjects spent more time pointing in the successful-look condition. These results suggest that apes are sensitive to the attentional states of gestural recipients, but their adjustments are aimed at multiple goals. We also found a greater number of individuals with a strong right-hand than left-hand preference for pointing.

  19. IceCube results from point-like source searches using 6 years of through-going muon data

    NASA Astrophysics Data System (ADS)

    Coenders, Stefan

    2016-04-01

    The IceCube Neutrino Observatory located at the geographic South Pole was designed to study and discover high energy neutrinos coming from both galactic and extra-galactic astrophysical sources. Track-like events induced by charged-current muon-neutrino interactions close to the IceCube detector give an angular resolution better than 1∘ above TeV energies. We present here the results of searches for point-like astrophysical neutrino sources on the full sky using 6 years of detector livetime, of which three years use the complete IceCube detector. Within 2000 days of detector livetime, IceCube is sensitive to a steady flux substantially below E2∂ϕ/∂E = 10-12 TeV cm-2 s-1 in the northern sky for neutrino energies above 10 TeV.

  20. Skylab S-193 radar altimeter experiment analyses and results

    NASA Technical Reports Server (NTRS)

    Brown, G. S. (Editor)

    1977-01-01

    The design of optimum filtering procedures for geoid recovery is discussed. Statistical error bounds are obtained for pointing angle estimates using average waveform data. A correlation of tracking loop bandwidth with magnitude of pointing error is established. The impact of ocean currents and precipitation on the received power are shown to be measurable effects. For large sea state conditions, measurements of sigma 0 deg indicate a distinct saturation level of about 8 dB. Near-nadir less than 15 deg values of sigma 0 deg are also presented and compared with theoretical models. Examination of Great Salt Lake Desert scattering data leads to rejection of a previously hypothesized specularly reflecting surface. Pulse-to-pulse correlation results are in agreement with quasi-monochromatic optics theoretical predictions and indicate a means for estimating direction of pointing error. Pulse compression techniques for and results of estimating significant waveheight from waveform data are presented and are also shown to be in good agreement with surface truth data. A number of results pertaining to system performance are presented.

  1. Structure investigations of ferromagnetic Co-Ni-Al alloys obtained by powder metallurgy.

    PubMed

    Maziarz, W; Dutkiewicz, J; Lityńska-Dobrzyńska, L; Santamarta, R; Cesari, E

    2010-03-01

    Elemental powders of Co, Ni and Al in the proper amounts to obtain Co(35)Ni(40)Al(25) and Co(40)Ni(35)Al(25) nominal compositions were ball milled in a high-energy mill for 80 h. After 40 h of milling, the formation of a Co (Ni, Al) solid solution with f.c.c. structure was verified by a change of the original lattice parameter and crystallite size. Analytical transmission electron microscopy observations and X-ray diffraction measurements of the final Co (Ni, Al) solid solution showed that the crystallite size scattered from 4 to 8 nm and lattice parameter a = 0.36086 nm. The chemical EDS point analysis of the milled powder particles allowed the calculation of the e/a ratio and revealed a high degree of chemical homogeneity of the powders. Hot pressing in vacuum of the milled powders resulted in obtaining compacts with a density of about 70% of the theoretical one. An additional heat treatment increased the density and induced the martensitic transformation in a parent phase. Selected area diffraction patterns and dark field images obtained from the heat-treated sample revealed small grains around 300 nm in diameter consisting mainly of the ordered gamma phase (gamma'), often appearing as twins, and a small amount of the L1(0) ordered martensite.

  2. A New Approach for Inspection of Selected Geometric Parameters of a Railway Track Using Image-Based Point Clouds

    PubMed Central

    Sawicki, Piotr

    2018-01-01

    The paper presents the results of testing a proposed image-based point clouds measuring method for geometric parameters determination of a railway track. The study was performed based on a configuration of digital images and reference control network. A DSLR (digital Single-Lens-Reflex) Nikon D5100 camera was used to acquire six digital images of the tested section of railway tracks. The dense point clouds and the 3D mesh model were generated with the use of two software systems, RealityCapture and PhotoScan, which have implemented different matching and 3D object reconstruction techniques: Multi-View Stereo and Semi-Global Matching, respectively. The study found that both applications could generate appropriate 3D models. Final meshes of 3D models were filtered with the MeshLab software. The CloudCompare application was used to determine the track gauge and cant for defined cross-sections, and the results obtained from point clouds by dense image matching techniques were compared with results of direct geodetic measurements. The obtained RMS difference in the horizontal (gauge) and vertical (cant) plane was RMS∆ < 0.45 mm. The achieved accuracy meets the accuracy condition of measurements and inspection of the rail tracks (error m < 1 mm), specified in the Polish branch railway instruction Id-14 (D-75) and the European technical norm EN 13848-4:2011. PMID:29509679

  3. A New Approach for Inspection of Selected Geometric Parameters of a Railway Track Using Image-Based Point Clouds.

    PubMed

    Gabara, Grzegorz; Sawicki, Piotr

    2018-03-06

    The paper presents the results of testing a proposed image-based point clouds measuring method for geometric parameters determination of a railway track. The study was performed based on a configuration of digital images and reference control network. A DSLR (digital Single-Lens-Reflex) Nikon D5100 camera was used to acquire six digital images of the tested section of railway tracks. The dense point clouds and the 3D mesh model were generated with the use of two software systems, RealityCapture and PhotoScan, which have implemented different matching and 3D object reconstruction techniques: Multi-View Stereo and Semi-Global Matching, respectively. The study found that both applications could generate appropriate 3D models. Final meshes of 3D models were filtered with the MeshLab software. The CloudCompare application was used to determine the track gauge and cant for defined cross-sections, and the results obtained from point clouds by dense image matching techniques were compared with results of direct geodetic measurements. The obtained RMS difference in the horizontal (gauge) and vertical (cant) plane was RMS∆ < 0.45 mm. The achieved accuracy meets the accuracy condition of measurements and inspection of the rail tracks (error m < 1 mm), specified in the Polish branch railway instruction Id-14 (D-75) and the European technical norm EN 13848-4:2011.

  4. Heat-flow measurements at shot points along the 1978 Saudi Arabia seismic deep-refraction line; Part I, Results of the measurements

    USGS Publications Warehouse

    Gettings, M.E.; Showail, Abdullah

    1982-01-01

    Heat-flow measurements were made at five onland shot points of the 1978 Saudi Arabian seismic deep-refraction line, which sample major tectonic elements of the Arabian Shield along a profile from Ar Riyad to the Farasan Islands. Because of the pattern drilling at each shot point, several holes (60 m deep) could be logged for temperature at each site and thus allow a better estimate of the geothermal gradient. Each site was mapped and sampled in detail, and modal and. chemical analyses of representative specimens were made in the laboratory. Thermal conductivities were computed from the modal analyses and single-mineral conductivity data. The resulting heat-flow values, combined with published values for the Red Sea and coastal plain, indicate a three-level pattern, with a heat flow of about 4.5 heat-flow unit (HFU) over the Red Sea axial trough, about 3.0 HFU over the shelf and coastal plain, and an essentially constant 1.0 HFU over the Arabian Shield at points well away from the suture zone with the oceanic crust. At three sites where the rocks are granitic, gamma-ray spectrometry techniques were employed to estimate thorium, potassium, and uranium concentrations. The resulting plot of heat generation versus heat flow suggests that in the Arabian Shield the relationship between heat flow and heat production is not linear. More heat-flow data are essential to establish or reject this conclusion.

  5. Symmetrical polyhedra (simple crystal forms) as orbits of noncrystallographic point symmetry groups

    NASA Astrophysics Data System (ADS)

    Ovsetsina, T. I.; Chuprunov, E. V.

    2017-09-01

    Simple crystal forms are analyzed as the orbits of noncrystallographic point symmetry groups on a set of smooth or structured ("hatched") planes of crystal space. Polyhedra with symmetrically equivalent faces, obtained using noncrystallographic point symmetry groups, are considered. All possible versions of simple forms for all noncrystallographic groups are listed in a unified table.

  6. A smartphone-based system for the automated management of point-of-care test results in hospitals.

    PubMed

    Jang, Dasom; Shin, Soo-Yong; Seo, Dong-Woo; Joo, Segyeong; Huh, Soo-Jin

    2015-04-01

    Managing test results is an important issue in hospitals because of the increasing use of point-of-care testing (POCT). Here, we propose a smartphone-based system for automatically managing POCT test results. We developed the system to provide convenience to the medical staffs. The system recognizes the patient identification or prescription number of the test by reading barcodes and provides a countdown to indicate when the results will be ready. When the countdown in finished, a picture of the test result is transferred to the electronic medical record server using the Health Level 7 protocol. Human immunodeficiency virus (HIV) kits were selected in this research because HIV is a life-threatening infectious virus, especially for the medical staff who treat undiagnosed patients. The performance of the system was verified from a survey of the users. The performance of the system was tested at the emergency room (ER) for 10 months using commercially available POCT kits for detecting HIV. The survey showed that, in total, 80% and 0% of users reported positive or negative feedback, respectively. The staff also reported that the system reduced total processing time by approximately 32 min, in addition to reducing workload. The developed automated management system was successfully tested at an ER for 10 months. The survey results show that the system is effective and that medical staff members who used the system are satisfied with using the system at the ER.

  7. Motion data classification on the basis of dynamic time warping with a cloud point distance measure

    NASA Astrophysics Data System (ADS)

    Switonski, Adam; Josinski, Henryk; Zghidi, Hafedh; Wojciechowski, Konrad

    2016-06-01

    The paper deals with the problem of classification of model free motion data. The nearest neighbors classifier which is based on comparison performed by Dynamic Time Warping transform with cloud point distance measure is proposed. The classification utilizes both specific gait features reflected by a movements of subsequent skeleton joints and anthropometric data. To validate proposed approach human gait identification challenge problem is taken into consideration. The motion capture database containing data of 30 different humans collected in Human Motion Laboratory of Polish-Japanese Academy of Information Technology is used. The achieved results are satisfactory, the obtained accuracy of human recognition exceeds 90%. What is more, the applied cloud point distance measure does not depend on calibration process of motion capture system which results in reliable validation.

  8. Thermodynamic limitations on the resolution obtainable with metal replicas.

    PubMed

    Woodward, J T; Zasadzinski, J A

    1996-12-01

    The major factor limiting resolution of metal-shadowed surfaces for electron and scanning tunnelling microscopy is the granularity of the metal film. This granularity had been believed to result from a recrystallization of the evaporated film, and hence could be limited by use of higher melting point materials for replication, or inhibited by adding carbon or other impurities to the film. However, evaporated and sputtered films of amorphous metal alloys that do not crystallize also show a granularity that decreases with increasing alloy melting point. A simple thermodynamic analysis shows that the granularity results from a dewetting of the typically low surface energy sample by the high surface energy metal film, similar to the beading up of drops of spilled mercury. The metal granularity and the resulting resolution of the metal-coated surface is proportional to the mobility of the metal on the surface after evaporation, which is related to the difference in temperature between the melting point of the metal and the sample surface temperature.

  9. A point particle model of lightly bound skyrmions

    NASA Astrophysics Data System (ADS)

    Gillard, Mike; Harland, Derek; Kirk, Elliot; Maybee, Ben; Speight, Martin

    2017-04-01

    A simple model of the dynamics of lightly bound skyrmions is developed in which skyrmions are replaced by point particles, each carrying an internal orientation. The model accounts well for the static energy minimizers of baryon number 1 ≤ B ≤ 8 obtained by numerical simulation of the full field theory. For 9 ≤ B ≤ 23, a large number of static solutions of the point particle model are found, all closely resembling size B subsets of a face centred cubic lattice, with the particle orientations dictated by a simple colouring rule. Rigid body quantization of these solutions is performed, and the spin and isospin of the corresponding ground states extracted. As part of the quantization scheme, an algorithm to compute the symmetry group of an oriented point cloud, and to determine its corresponding Finkelstein-Rubinstein constraints, is devised.

  10. An Iterative Closest Points Algorithm for Registration of 3D Laser Scanner Point Clouds with Geometric Features.

    PubMed

    He, Ying; Liang, Bin; Yang, Jun; Li, Shunzhi; He, Jin

    2017-08-11

    The Iterative Closest Points (ICP) algorithm is the mainstream algorithm used in the process of accurate registration of 3D point cloud data. The algorithm requires a proper initial value and the approximate registration of two point clouds to prevent the algorithm from falling into local extremes, but in the actual point cloud matching process, it is difficult to ensure compliance with this requirement. In this paper, we proposed the ICP algorithm based on point cloud features (GF-ICP). This method uses the geometrical features of the point cloud to be registered, such as curvature, surface normal and point cloud density, to search for the correspondence relationships between two point clouds and introduces the geometric features into the error function to realize the accurate registration of two point clouds. The experimental results showed that the algorithm can improve the convergence speed and the interval of convergence without setting a proper initial value.

  11. An Iterative Closest Points Algorithm for Registration of 3D Laser Scanner Point Clouds with Geometric Features

    PubMed Central

    Liang, Bin; Yang, Jun; Li, Shunzhi; He, Jin

    2017-01-01

    The Iterative Closest Points (ICP) algorithm is the mainstream algorithm used in the process of accurate registration of 3D point cloud data. The algorithm requires a proper initial value and the approximate registration of two point clouds to prevent the algorithm from falling into local extremes, but in the actual point cloud matching process, it is difficult to ensure compliance with this requirement. In this paper, we proposed the ICP algorithm based on point cloud features (GF-ICP). This method uses the geometrical features of the point cloud to be registered, such as curvature, surface normal and point cloud density, to search for the correspondence relationships between two point clouds and introduces the geometric features into the error function to realize the accurate registration of two point clouds. The experimental results showed that the algorithm can improve the convergence speed and the interval of convergence without setting a proper initial value. PMID:28800096

  12. a Hadoop-Based Algorithm of Generating dem Grid from Point Cloud Data

    NASA Astrophysics Data System (ADS)

    Jian, X.; Xiao, X.; Chengfang, H.; Zhizhong, Z.; Zhaohui, W.; Dengzhong, Z.

    2015-04-01

    Airborne LiDAR technology has proven to be the most powerful tools to obtain high-density, high-accuracy and significantly detailed surface information of terrain and surface objects within a short time, and from which the Digital Elevation Model of high quality can be extracted. Point cloud data generated from the pre-processed data should be classified by segmentation algorithms, so as to differ the terrain points from disorganized points, then followed by a procedure of interpolating the selected points to turn points into DEM data. The whole procedure takes a long time and huge computing resource due to high-density, that is concentrated on by a number of researches. Hadoop is a distributed system infrastructure developed by the Apache Foundation, which contains a highly fault-tolerant distributed file system (HDFS) with high transmission rate and a parallel programming model (Map/Reduce). Such a framework is appropriate for DEM generation algorithms to improve efficiency. Point cloud data of Dongting Lake acquired by Riegl LMS-Q680i laser scanner was utilized as the original data to generate DEM by a Hadoop-based algorithms implemented in Linux, then followed by another traditional procedure programmed by C++ as the comparative experiment. Then the algorithm's efficiency, coding complexity, and performance-cost ratio were discussed for the comparison. The results demonstrate that the algorithm's speed depends on size of point set and density of DEM grid, and the non-Hadoop implementation can achieve a high performance when memory is big enough, but the multiple Hadoop implementation can achieve a higher performance-cost ratio, while point set is of vast quantities on the other hand.

  13. Error analysis in stereo vision for location measurement of 3D point

    NASA Astrophysics Data System (ADS)

    Li, Yunting; Zhang, Jun; Tian, Jinwen

    2015-12-01

    Location measurement of 3D point in stereo vision is subjected to different sources of uncertainty that propagate to the final result. For current methods of error analysis, most of them are based on ideal intersection model to calculate the uncertainty region of point location via intersecting two fields of view of pixel that may produce loose bounds. Besides, only a few of sources of error such as pixel error or camera position are taken into account in the process of analysis. In this paper we present a straightforward and available method to estimate the location error that is taken most of source of error into account. We summed up and simplified all the input errors to five parameters by rotation transformation. Then we use the fast algorithm of midpoint method to deduce the mathematical relationships between target point and the parameters. Thus, the expectations and covariance matrix of 3D point location would be obtained, which can constitute the uncertainty region of point location. Afterwards, we turned back to the error propagation of the primitive input errors in the stereo system and throughout the whole analysis process from primitive input errors to localization error. Our method has the same level of computational complexity as the state-of-the-art method. Finally, extensive experiments are performed to verify the performance of our methods.

  14. Analytic Result for the Two-loop Six-point NMHV Amplitude in N = 4 Super Yang-Mills Theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dixon, Lance J.; /SLAC; Drummond, James M.

    2012-02-15

    We provide a simple analytic formula for the two-loop six-point ratio function of planar N = 4 super Yang-Mills theory. This result extends the analytic knowledge of multi-loop six-point amplitudes beyond those with maximal helicity violation. We make a natural ansatz for the symbols of the relevant functions appearing in the two-loop amplitude, and impose various consistency conditions, including symmetry, the absence of spurious poles, the correct collinear behavior, and agreement with the operator product expansion for light-like (super) Wilson loops. This information reduces the ansatz to a small number of relatively simple functions. In order to fix these parametersmore » uniquely, we utilize an explicit representation of the amplitude in terms of loop integrals that can be evaluated analytically in various kinematic limits. The final compact analytic result is expressed in terms of classical polylogarithms, whose arguments are rational functions of the dual conformal cross-ratios, plus precisely two functions that are not of this type. One of the functions, the loop integral {Omega}{sup (2)}, also plays a key role in a new representation of the remainder function R{sub 6}{sup (2)} in the maximally helicity violating sector. Another interesting feature at two loops is the appearance of a new (parity odd) x (parity odd) sector of the amplitude, which is absent at one loop, and which is uniquely determined in a natural way in terms of the more familiar (parity even) x (parity even) part. The second non-polylogarithmic function, the loop integral {tilde {Omega}}{sup (2)}, characterizes this sector. Both {Omega}{sup (2)} and {tilde {Omega}}{sup (2)} can be expressed as one-dimensional integrals over classical polylogarithms with rational arguments.« less

  15. [Prevalence of Clostridium difficile infection in hospitalized patients with diarrhea: results of a French prospective multicenter bi-annual point prevalence study].

    PubMed

    Barbut, Frédéric; Ramé, Laetitia; Petit, Amandine; Suzon, Laina; de Chevigny, Alix; Eckert, Catherine

    2015-04-01

    Clostridium difficile infections represent the major cause of healthcare-associated diarrhea. The objective of the study was to determine the incidence of C. difficile infection (CDI) in 2012 and to assess the under-estimation of the disease in France. Seventy healthcare facilities participated in a prospective point prevalence study. Each laboratory was requested to send all the diarrheal stool samples from hospitalized patients during 2 days (one in December 2012 and one in July 2013) to the National Reference Laboratory (NRL) for C. difficile, irrespective of a medical request for C. difficile. At the NRL, stool samples were analyzed using the Quik Chek Complete assay (Alere). Positive samples for glutamate deshydrogenase or toxins were confirmed by the toxigenic culture. Results obtained by the NRL were then compared to those given by each healthcare facility. Incidence of CDI in 2012 was provided by each healthcare facility through a specific questionnaire. Mean incidence of CDI reported in 2012 by the HCF was 3.6 ± 2.9 per 10,000 patient-days; the incidence was positively correlated to the density testing (defined by the number of tests per 10,000 patient-days), which varied across the HCF (median 29.0 per 10,000 patient-days, IQR 19-50). During the bi-annual point prevalence survey, 651 stool samples were included and 90 were positive for C. difficile in culture. The overall prevalence of patients infected by a toxigenic C. difficile strain was 9.7% (63/651) and the prevalence of patients colonized by a non-toxigenic strain was 4.2% (27/651). Among the 65 cases of CDI detected by the NRL, 35 (55.6%) were missed by the participating HCF because of a lack of sensitivity of the methods used for the diagnosis (16/63, 25.4%) or because of a lack of clinical suspicion (19/63, 30.2%). The incidence of CDI in 2012 has increased in France compared to that of 2009 but is still underestimated because of a lack of clinical suspicion or a lack of sensitivity of methods

  16. General structure of fermion two-point function and its spectral representation in a hot magnetized medium

    NASA Astrophysics Data System (ADS)

    Das, Aritra; Bandyopadhyay, Aritra; Roy, Pradip K.; Mustafa, Munshi G.

    2018-02-01

    We have systematically constructed the general structure of the fermion self-energy and the effective quark propagator in the presence of a nontrivial background such as a hot magnetized medium. This is applicable to both QED and QCD. The hard thermal loop approximation has been used for the heat bath. We have also examined transformation properties of the effective fermion propagator under some of the discrete symmetries of the system. Using the effective fermion propagator we have analyzed the fermion dispersion spectra in a hot magnetized medium along with the spinor for each fermion mode obtained by solving the modified Dirac equation. The fermion spectra is found to reflect the discrete symmetries of the two-point functions. We note that for a chirally symmetric theory the degenerate left- and right-handed chiral modes in vacuum or in a heat bath get separated and become asymmetric in the presence of a magnetic field without disturbing the chiral invariance. The obtained general structure of the two-point functions is verified by computing the three-point function, which agrees with the existing results in one-loop order. Finally, we have computed explicitly the spectral representation of the two-point functions which would be very important to study the spectral properties of the hot magnetized medium corresponding to QED and QCD with background magnetic field.

  17. ROBIN: a platform for evaluating automatic target recognition algorithms: II. Protocols used for evaluating algorithms and results obtained on the SAGEM DS database

    NASA Astrophysics Data System (ADS)

    Duclos, D.; Lonnoy, J.; Guillerm, Q.; Jurie, F.; Herbin, S.; D'Angelo, E.

    2008-04-01

    Over the five past years, the computer vision community has explored many different avenues of research for Automatic Target Recognition. Noticeable advances have been made and we are now in the situation where large-scale evaluations of ATR technologies have to be carried out, to determine what the limitations of the recently proposed methods are and to determine the best directions for future works. ROBIN, which is a project funded by the French Ministry of Defence and by the French Ministry of Research, has the ambition of being a new reference for benchmarking ATR algorithms in operational contexts. This project, headed by major companies and research centers involved in Computer Vision R&D in the field of Defense (Bertin Technologies, CNES, ECA, DGA, EADS, INRIA, ONERA, MBDA, SAGEM, THALES) recently released a large dataset of several thousands of hand-annotated infrared and RGB images of different targets in different situations. Setting up an evaluation campaign requires us to define, accurately and carefully, sets of data (both for training ATR algorithms and for their evaluation), tasks to be evaluated, and finally protocols and metrics for the evaluation. ROBIN offers interesting contributions to each one of these three points. This paper first describes, justifies and defines the set of functions used in the ROBIN competitions and relevant for evaluating ATR algorithms (Detection, Localization, Recognition and Identification). It also defines the metrics and the protocol used for evaluating these functions. In the second part of the paper, the results obtained by several state-of-the-art algorithms on the SAGEM DS database (a subpart of ROBIN) are presented and discussed

  18. Mirrored pyramidal wells for simultaneous multiple vantage point microscopy.

    PubMed

    Seale, K T; Reiserer, R S; Markov, D A; Ges, I A; Wright, C; Janetopoulos, C; Wikswo, J P

    2008-10-01

    We report a novel method for obtaining simultaneous images from multiple vantage points of a microscopic specimen using size-matched microscopic mirrors created from anisotropically etched silicon. The resulting pyramidal wells enable bright-field and fluorescent side-view images, and when combined with z-sectioning, provide additional information for 3D reconstructions of the specimen. We have demonstrated the 3D localization and tracking over time of the centrosome of a live Dictyostelium discoideum. The simultaneous acquisition of images from multiple perspectives also provides a five-fold increase in the theoretical collection efficiency of emitted photons, a property which may be useful for low-light imaging modalities such as bioluminescence, or low abundance surface-marker labelling.

  19. Mirrored pyramidal wells for simultaneous multiple vantage point microscopy

    PubMed Central

    Seale, K.T.; Reiserer, R.S.; Markov, D.A.; Ges, I.A.; Wright, C.; Janetopoulos, C.; Wikswo, J.P.

    2013-01-01

    Summary We report a novel method for obtaining simultaneous images from multiple vantage points of a microscopic specimen using size-matched microscopic mirrors created from anisotropically etched silicon. The resulting pyramidal wells enable bright-field and fluorescent side-view images, and when combined with z-sectioning, provide additional information for 3D reconstructions of the specimen. We have demonstrated the 3D localization and tracking over time of the centrosome of a live Dictyostelium discoideum. The simultaneous acquisition of images from multiple perspectives also provides a five-fold increase in the theoretical collection efficiency of emitted photons, a property which may be useful for low-light imaging modalities such as bioluminescence, or low abundance surface-marker labelling. PMID:19017196

  20. On the numerical solution of the dynamically loaded hydrodynamic lubrication of the point contact problem

    NASA Technical Reports Server (NTRS)

    Lim, Sang G.; Brewe, David E.; Prahl, Joseph M.

    1990-01-01

    The transient analysis of hydrodynamic lubrication of a point-contact is presented. A body-fitted coordinate system is introduced to transform the physical domain to a rectangular computational domain, enabling the use of the Newton-Raphson method for determining pressures and locating the cavitation boundary, where the Reynolds boundary condition is specified. In order to obtain the transient solution, an explicit Euler method is used to effect a time march. The transient dynamic load is a sinusoidal function of time with frequency, fractional loading, and mean load as parameters. Results include the variation of the minimum film thickness and phase-lag with time as functions of excitation frequency. The results are compared with the analytic solution to the transient step bearing problem with the same dynamic loading function. The similarities of the results suggest an approximate model of the point contact minimum film thickness solution.

  1. Super-resolution image reconstruction from UAS surveillance video through affine invariant interest point-based motion estimation

    NASA Astrophysics Data System (ADS)

    He, Qiang; Schultz, Richard R.; Wang, Yi; Camargo, Aldo; Martel, Florent

    2008-01-01

    In traditional super-resolution methods, researchers generally assume that accurate subpixel image registration parameters are given a priori. In reality, accurate image registration on a subpixel grid is the single most critically important step for the accuracy of super-resolution image reconstruction. In this paper, we introduce affine invariant features to improve subpixel image registration, which considerably reduces the number of mismatched points and hence makes traditional image registration more efficient and more accurate for super-resolution video enhancement. Affine invariant interest points include those corners that are invariant to affine transformations, including scale, rotation, and translation. They are extracted from the second moment matrix through the integration and differentiation covariance matrices. Our tests are based on two sets of real video captured by a small Unmanned Aircraft System (UAS) aircraft, which is highly susceptible to vibration from even light winds. The experimental results from real UAS surveillance video show that affine invariant interest points are more robust to perspective distortion and present more accurate matching than traditional Harris/SIFT corners. In our experiments on real video, all matching affine invariant interest points are found correctly. In addition, for the same super-resolution problem, we can use many fewer affine invariant points than Harris/SIFT corners to obtain good super-resolution results.

  2. 3D micro-mapping: Towards assessing the quality of crowdsourcing to support 3D point cloud analysis

    NASA Astrophysics Data System (ADS)

    Herfort, Benjamin; Höfle, Bernhard; Klonner, Carolin

    2018-03-01

    In this paper, we propose a method to crowdsource the task of complex three-dimensional information extraction from 3D point clouds. We design web-based 3D micro tasks tailored to assess segmented LiDAR point clouds of urban trees and investigate the quality of the approach in an empirical user study. Our results for three different experiments with increasing complexity indicate that a single crowdsourcing task can be solved in a very short time of less than five seconds on average. Furthermore, the results of our empirical case study reveal that the accuracy, sensitivity and precision of 3D crowdsourcing are high for most information extraction problems. For our first experiment (binary classification with single answer) we obtain an accuracy of 91%, a sensitivity of 95% and a precision of 92%. For the more complex tasks of the second Experiment 2 (multiple answer classification) the accuracy ranges from 65% to 99% depending on the label class. Regarding the third experiment - the determination of the crown base height of individual trees - our study highlights that crowdsourcing can be a tool to obtain values with even higher accuracy in comparison to an automated computer-based approach. Finally, we found out that the accuracy of the crowdsourced results for all experiments is hardly influenced by characteristics of the input point cloud data and of the users. Importantly, the results' accuracy can be estimated using agreement among volunteers as an intrinsic indicator, which makes a broad application of 3D micro-mapping very promising.

  3. Artificial equilibrium points in binary asteroid systems with continuous low-thrust

    NASA Astrophysics Data System (ADS)

    Bu, Shichao; Li, Shuang; Yang, Hongwei

    2017-08-01

    The positions and dynamical characteristics of artificial equilibrium points (AEPs) in the vicinity of a binary asteroid with continuous low-thrust are studied. The restricted ellipsoid-ellipsoid model of binary system is employed for the binary asteroid system. The positions of AEPs are obtained by this model. It is found that the set of the point L1 or L2 forms a shape of an ellipsoid while the set of the point L3 forms a shape like a "banana". The effect of the continuous low-thrust on the feasible region of motion is analyzed by zero velocity curves. Because of using the low-thrust, the unreachable region can become reachable. The linearized equations of motion are derived for stability's analysis. Based on the characteristic equation of the linearized equations, the stability conditions are derived. The stable regions of AEPs are investigated by a parametric analysis. The effect of the mass ratio and ellipsoid parameters on stable region is also discussed. The results show that the influence of the mass ratio on the stable regions is more significant than the parameters of ellipsoid.

  4. The far ultraviolet /1200-1900 A/ spectrum of Jupiter obtained with a rocket-borne multichannel spectrometer

    NASA Technical Reports Server (NTRS)

    Giles, J. W.; Moos, H. W.; Mckinney, W. R.

    1976-01-01

    Far-ultraviolet spectra of Jupiter with a significant improvement in sensitivity and spectral resolution have been obtained from a sounding rocket by using a 10-channel spectrometer behind a pointing telescope. The major results obtained from these spectra are: (1) measurement of the Jovian H I 1216-A brightness (a comparison with other measurements indicates that the Ly-alpha emission is likely to be variable); (2) measurement of the wavelength-dependent albedo for Rayleigh-scattered solar radiation from about 1550 to 1875 A with approximately 25-A resolution, making it possible to set revised upper limits on the abundances of some of the minor constituents in the upper Jovian atmosphere; and (3) a demonstration that weak emissions between approximately 1250 and 1500 A and near 1600 A are probably the Lyman bands of H2 excited by low-energy electrons.

  5. Transfers between libration-point orbits in the elliptic restricted problem

    NASA Astrophysics Data System (ADS)

    Hiday-Johnston, L. A.; Howell, K. C.

    1994-04-01

    A strategy is formulated to design optimal time-fixed impulsive transfers between three-dimensional libration-point orbits in the vicinity of the interior L1 libration point of the Sun-Earth/Moon barycenter system. The adjoint equation in terms of rotating coordinates in the elliptic restricted three-body problem is shown to be of a distinctly different form from that obtained in the analysis of trajectories in the two-body problem. Also, the necessary conditions for a time-fixed two-impulse transfer to be optimal are stated in terms of the primer vector. Primer vector theory is then extended to nonoptimal impulsive trajectories in order to establish a criterion whereby the addition of an interior impulse reduces total fuel expenditure. The necessary conditions for the local optimality of a transfer containing additional impulses are satisfied by requiring continuity of the Hamiltonian and the derivative of the primer vector at all interior impulses. Determination of location, orientation, and magnitude of each additional impulse is accomplished by the unconstrained minimization of the cost function using a multivariable search method. Results indicate that substantial savings in fuel can be achieved by the addition of interior impulsive maneuvers on transfers between libration-point orbits.

  6. Fast Semantic Segmentation of 3d Point Clouds with Strongly Varying Density

    NASA Astrophysics Data System (ADS)

    Hackel, Timo; Wegner, Jan D.; Schindler, Konrad

    2016-06-01

    We describe an effective and efficient method for point-wise semantic classification of 3D point clouds. The method can handle unstructured and inhomogeneous point clouds such as those derived from static terrestrial LiDAR or photogammetric reconstruction; and it is computationally efficient, making it possible to process point clouds with many millions of points in a matter of minutes. The key issue, both to cope with strong variations in point density and to bring down computation time, turns out to be careful handling of neighborhood relations. By choosing appropriate definitions of a point's (multi-scale) neighborhood, we obtain a feature set that is both expressive and fast to compute. We evaluate our classification method both on benchmark data from a mobile mapping platform and on a variety of large, terrestrial laser scans with greatly varying point density. The proposed feature set outperforms the state of the art with respect to per-point classification accuracy, while at the same time being much faster to compute.

  7. Perpetual Points: New Tool for Localization of Coexisting Attractors in Dynamical Systems

    NASA Astrophysics Data System (ADS)

    Dudkowski, Dawid; Prasad, Awadhesh; Kapitaniak, Tomasz

    Perpetual points (PPs) are special critical points for which the magnitude of acceleration describing the dynamics drops to zero, while the motion is still possible (stationary points are excluded), e.g. considering the motion of the particle in the potential field, at perpetual point, it has zero acceleration and nonzero velocity. We show that using PPs we can trace all the stable fixed points in the system, and that the structure of trajectories leading from former points to stable equilibria may be similar to orbits obtained from unstable stationary points. Moreover, we argue that the concept of perpetual points may be useful in tracing unexpected attractors (hidden or rare attractors with small basins of attraction). We show potential applicability of this approach by analyzing several representative systems of physical significance, including the damped oscillator, pendula, and the Henon map. We suggest that perpetual points may be a useful tool for localizing coexisting attractors in dynamical systems.

  8. Pennsylvania StreamStats--A web-based application for obtaining water-resource-related information

    USGS Publications Warehouse

    Stuckey, Marla H.; Hoffman, Scott A.

    2010-01-01

    StreamStats is a national web-based Geographic Information System (GIS) application, developed by the U.S. Geological Survey (USGS), in cooperation with Environmental Systems Research Institute, Inc., to provide a variety of water-resource-related information. Users can easily obtain descriptive information, basin characteristics, and streamflow statistics for USGS streamgages and ungaged stream locations throughout Pennsylvania. StreamStats also allows users to search upstream and (or) downstream from user-selected points to identify locations of and obtain information for water-resource-related activities, such as dams and streamgages.

  9. Planialtimetric Accuracy Evaluation of Digital Surface Model (dsm) and Digital Terrain Model (dtm) Obtained from Aerial Survey with LIDAR

    NASA Astrophysics Data System (ADS)

    Cruz, C. B. M.; Barros, R. S.; Rabaco, L. M. L.

    2012-07-01

    It's noticed a significant increase in the development of orbital and airborne sensors that enable the extraction of three-dimensional data. Consequently, it's important the increment of studies about the quality of altimetric values derived from these sensors to verify if the improvements implemented in the acquisition of data may influence the results. In this context, as part of a larger project that aims to evaluate the accuracy of various sensors, this work aims to analysis the planialtimetric accuracy of DSM and DTM generated from an aerial survey with LIDAR, using as reference for the planimetric analysis of the orthophotos obtained. The project was developed for an area of São Sebastião city, located in the basin of the North Coast of São Paulo state. The area's relief is very steep, with a predominance of dense forest vegetation, typical of the Atlantic Forest. All points have been established in the field, with the use of GNSS of one frequency (L1) through static relative positioning, acquiring a minimum of 1,500 epochs, for a distance less than 20 km to the base. In this work it's considered the Brazilian standard specifications for classification of cartographic bases (PEC). The Brazilian company responsible for the aerial survey (LACTEC) gave the following products for analysis: point clouds in raw format (x, y, z) using orthometric heights; point clouds (first and last pulse) for each range of flight to verify systematic errors; DTM uniformly spaced, filtering small natural obstacles, buildings and vegetation, in Geotiff format; DSM also uniformly spaced, in Geotiff format; and the mosaic of georeferenced digital images. The analysis realized on products from the LIDAR indicated their adoption to the scales 1:2,000 (Class A for the orthophotos and Class B for the DTM) and 1:5,000 (class C for the DSM). There were no indications of trends in the results. The average error was 0.01 m. It's important that new areas with different topographic

  10. Elliptic Curve Integral Points on y2 = x3 + 3x ‑ 14

    NASA Astrophysics Data System (ADS)

    Zhao, Jianhong

    2018-03-01

    The positive integer points and integral points of elliptic curves are very important in the theory of number and arithmetic algebra, it has a wide range of applications in cryptography and other fields. There are some results of positive integer points of elliptic curve y 2 = x 3 + ax + b, a, b ∈ Z In 1987, D. Zagier submit the question of the integer points on y 2 = x 3 ‑ 27x + 62, it count a great deal to the study of the arithmetic properties of elliptic curves. In 2009, Zhu H L and Chen J H solved the problem of the integer points on y 2 = x 3 ‑ 27x + 62 by using algebraic number theory and P-adic analysis method. In 2010, By using the elementary method, Wu H M obtain all the integral points of elliptic curves y 2 = x 3 ‑ 27x ‑ 62. In 2015, Li Y Z and Cui B J solved the problem of the integer points on y 2 = x 3 ‑ 21x ‑ 90 By using the elementary method. In 2016, Guo J solved the problem of the integer points on y 2 = x 3 + 27x + 62 by using the elementary method. In 2017, Guo J proved that y 2 = x 3 ‑ 21x + 90 has no integer points by using the elementary method. Up to now, there is no relevant conclusions on the integral points of elliptic curves y 2 = x 3 + 3x ‑ 14, which is the subject of this paper. By using congruence and Legendre Symbol, it can be proved that elliptic curve y 2 = x 3 + 3x ‑ 14 has only one integer point: (x, y) = (2, 0).

  11. Proper Analytic Point Spread Function for Lateral Modulation

    NASA Astrophysics Data System (ADS)

    Chikayoshi Sumi,; Kunio Shimizu,; Norihiko Matsui,

    2010-07-01

    For ultrasonic lateral modulation for the imaging and measurement of tissue motion, better envelope shapes of the point spread function (PSF) than of a parabolic function are searched for within analytic functions or windows on the basis of the knowledge of the ideal shape of PSF previously obtained, i.e., having a large full width at half maximum and short feet. Through simulation of displacement vector measurement, better shapes are determined. As a better shape, a new window is obtained from a Turkey window by changing Hanning windows by power functions with an order larger than the second order. The order of measurement accuracies obtained is as follows, the new window > rectangular window > power function with a higher order > parabolic function > Akaike window.

  12. Planetary system detection by POINTS

    NASA Technical Reports Server (NTRS)

    Reasenberg, Robert D.

    1993-01-01

    The final report and semiannual reports 1, 2, and 3 in response to the study of 'Planetary System Detection by POINTS' is presented. The grant covered the period from 15 Jun. 1988 through 31 Dec. 1989. The work during that period comprised the further development and refinement of the POINTS concept. The status of the POINTS development at the end of the Grant period was described by Reasenberg in a paper given at the JPL Workshop on Space Interferometry, 12-13 Mar. 1990, and distributed as CfA Preprint 3138. That paper, 'POINTS: a Small Astrometric Interferometer,' follows as Appendix-A. Our proposal P2276-7-09, dated July 1990, included a more detailed description of the state of the development of POINTS at the end of the tenure of Grant NAGW-1355. That proposal, which resulted in Grant NAGW-2497, is included by reference.

  13. Variation character of stagnation point heat flux for hypersonic pointed bodies from continuum to rarefied flow states and its bridge function study

    NASA Astrophysics Data System (ADS)

    Wang, Zhihui; Bao, Lin; Tong, Binggang

    2009-12-01

    This paper is a research on the variation character of stagnation point heat flux for hypersonic pointed bodies from continuum to rarefied flow states by using theoretical analysis and numerical simulation methods. The newly developed near space hypersonic cruise vehicles have sharp noses and wingtips, which desires exact and relatively simple methods to estimate the stagnation point heat flux. With the decrease of the curvature radius of the leading edge, the flow becomes rarefied gradually, and viscous interaction effects and rarefied gas effects come forth successively, which results in that the classical Fay-Riddell equation under continuum hypothesis will become invalid and the variation of stagnation point heat flux is characterized by a new trend. The heat flux approaches the free molecular flow limit instead of an infinite value when the curvature radius of the leading edge tends to 0. The physical mechanism behind this phenomenon remains in need of theoretical study. Firstly, due to the fact that the whole flow regime can be described by Boltzmann equation, the continuum and rarefied flow are analyzed under a uniform framework. A relationship is established between the molecular collision insufficiency in rarefied flow and the failure of Fourier’s heat conduction law along with the increasing significance of the nonlinear heat flux. Then based on an inspiration drew from Burnett approximation, control factors are grasped and a specific heat flux expression containing the nonlinear term is designed in the stagnation region of hypersonic leading edge. Together with flow pattern analysis, the ratio of nonlinear to linear heat flux W r is theoretically obtained as a parameter which reflects the influence of nonlinear factors, i.e. a criterion to classify the hypersonic rarefied flows. Ultimately, based on the characteristic parameter W r , a bridge function with physical background is constructed, which predicts comparative reasonable results in coincidence

  14. Nonlinear analysis and performance evaluation of the Annular Suspension and Pointing System (ASPS)

    NASA Technical Reports Server (NTRS)

    Joshi, S. M.

    1978-01-01

    The Annular Suspension and Pointing System (ASPS) can provide high accurate fine pointing for a variety of solar-, stellar-, and Earth-viewing scientific instruments during space shuttle orbital missions. In this report, a detailed nonlinear mathematical model is developed for the ASPS/Space Shuttle system. The equations are augmented with nonlinear models of components such as magnetic actuators and gimbal torquers. Control systems and payload attitude state estimators are designed in order to obtain satisfactory pointing performance, and statistical pointing performance is predicted in the presence of measurement noise and disturbances.

  15. Expanded uncertainty associated with determination of isotope enrichment factors: Comparison of two point calculation and Rayleigh-plot.

    PubMed

    Julien, Maxime; Gilbert, Alexis; Yamada, Keita; Robins, Richard J; Höhener, Patrick; Yoshida, Naohiro; Remaud, Gérald S

    2018-01-01

    The enrichment factor (ε) is a common way to express Isotope Effects (IEs) associated with a phenomenon. Many studies determine ε using a Rayleigh-plot, which needs multiple data points. More recent articles describe an alternative method using the Rayleigh equation that allows the determination of ε using only one experimental point, but this method is often subject to controversy. However, a calculation method using two points (one experimental point and one at t 0 ) should lead to the same results because the calculation is derived from the Rayleigh equation. But, it is frequently asked "what is the valid domain of use of this two point calculation?" The primary aim of the present work is a systematic comparison of results obtained with these two methodologies and the determination of the conditions required for the valid calculation of ε. In order to evaluate the efficiency of the two approaches, the expanded uncertainty (U) associated with determining ε has been calculated using experimental data from three published articles. The second objective of the present work is to describe how to determine the expanded uncertainty (U) associated with determining ε. Comparative methodologies using both Rayleigh-plot and two point calculation are detailed and it is clearly demonstrated that calculation of ε using a single data point can give the same result as a Rayleigh-plot provided one strict condition is respected: that the experimental value is measured at a small fraction of unreacted substrate (f < 30%). This study will help stable isotope users to present their results in a more rigorous expression: ε ± U and therefore to define better the significance of an experimental results prior interpretation. Capsule: Enrichment factor can be determined through two different methods and the calculation of associated expanded uncertainty allows checking its significance. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Effect of Receiver Choosing on Point Positions Determination in Network RTK

    NASA Astrophysics Data System (ADS)

    Bulbul, Sercan; Inal, Cevat

    2016-04-01

    Nowadays, the developments in GNSS technique allow to determinate point positioning in real time. Initially, point positioning was determined by RTK (Real Time Kinematic) based on a reference station. But, to avoid systematic errors in this method, distance between the reference points and rover receiver must be shorter than10 km. To overcome this restriction in RTK method, the idea of setting more than one reference point had been suggested and, CORS (Continuously Operations Reference Systems) was put into practice. Today, countries like ABD, Germany, Japan etc. have set CORS network. CORS-TR network which has 146 reference points has also been established in 2009 in Turkey. In CORS-TR network, active CORS approach was adopted. In Turkey, CORS-TR reference stations covering whole country are interconnected and, the positions of these stations and atmospheric corrections are continuously calculated. In this study, in a selected point, RTK measurements based on CORS-TR, were made with different receivers (JAVAD TRIUMPH-1, TOPCON Hiper V, MAGELLAN PRoMark 500, PENTAX SMT888-3G, SATLAB SL-600) and with different correction techniques (VRS, FKP, MAC). In the measurements, epoch interval was taken as 5 seconds and measurement time as 1 hour. According to each receiver and each correction technique, means and differences between maximum and minimum values of measured coordinates, root mean squares in the directions of coordinate axis and 2D and 3D positioning precisions were calculated, the results were evaluated by statistical methods and the obtained graphics were interpreted. After evaluation of the measurements and calculations, for each receiver and each correction technique; the coordinate differences between maximum and minimum values were measured to be less than 8 cm, root mean squares in coordinate axis directions less than ±1.5 cm, 2D point positioning precisions less than ±1.5 cm and 3D point positioning precisions less than ±1.5 cm. In the measurement

  17. Some efficient methods for obtaining infinite series solutions of n-th order linear ordinary differential equations

    NASA Technical Reports Server (NTRS)

    Allen, G.

    1972-01-01

    The use of the theta-operator method and generalized hypergeometric functions in obtaining solutions to nth-order linear ordinary differential equations is explained. For completeness, the analysis of the differential equation to determine whether the point of expansion is an ordinary point or a regular singular point is included. The superiority of the two methods shown over the standard method is demonstrated by using all three of the methods to work out several examples. Also included is a compendium of formulae and properties of the theta operator and generalized hypergeometric functions which is complete enough to make the report self-contained.

  18. Comparison of SOM point densities based on different criteria.

    PubMed

    Kohonen, T

    1999-11-15

    Point densities of model (codebook) vectors in self-organizing maps (SOMs) are evaluated in this article. For a few one-dimensional SOMs with finite grid lengths and a given probability density function of the input, the numerically exact point densities have been computed. The point density derived from the SOM algorithm turned out to be different from that minimizing the SOM distortion measure, showing that the model vectors produced by the basic SOM algorithm in general do not exactly coincide with the optimum of the distortion measure. A new computing technique based on the calculus of variations has been introduced. It was applied to the computation of point densities derived from the distortion measure for both the classical vector quantization and the SOM with general but equal dimensionality of the input vectors and the grid, respectively. The power laws in the continuum limit obtained in these cases were found to be identical.

  19. Effective intermolecular potential and critical point for C60 molecule

    NASA Astrophysics Data System (ADS)

    Ramos, J. Eloy

    2017-07-01

    The approximate nonconformal (ANC) theory is applied to the C60 molecule. A new binary potential function is developed for C60, which has three parameters only and is obtained by averaging the site-site carbon interactions on the surface of two C60 molecules. It is shown that the C60 molecule follows, to a good approximation, the corresponding states principle with n-C8H18, n-C4F10 and n-C5F12. The critical point of C60 is estimated in two ways: first by applying the corresponding states principle under the framework of the ANC theory, and then by using previous computer simulations. The critical parameters obtained by applying the corresponding states principle, although very different from those reported in the literature, are consistent with the previous results of the ANC theory. It is shown that the Girifalco potential does not correspond to an average of the site-site carbon-carbon interaction.

  20. Elastohydrodynamic lubrication of point contacts. Ph.D. Thesis - Leeds Univ.

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1976-01-01

    A procedure for the numerical solution of the complete, isothermal, elastohydrodynamic lubrication problem for point contacts is given. This procedure calls for the simultaneous solution of the elasticity and Reynolds equations. By using this theory the influence of the ellipticity parameter and the dimensionless speed, load, and material parameters on the minimum and central film thicknesses was investigated. Thirty-four different cases were used in obtaining the fully flooded minimum- and central-film-thickness formulas. Lubricant starvation was also studied. From the results it was possible to express the minimum film thickness for a starved condition in terms of the minimum film thickness for a fully flooded condition, the speed parameter, and the inlet distance. Fifteen additional cases plus three fully flooded cases were used in obtaining this formula. Contour plots of pressure and film thickness in and around the contact have been presented for both fully flooded and starved lubrication conditions.

  1. Constraints on Stress Components at the Internal Singular Point of an Elastic Compound Structure

    NASA Astrophysics Data System (ADS)

    Pestrenin, V. M.; Pestrenina, I. V.

    2017-03-01

    The classical analytical and numerical methods for investigating the stress-strain state (SSS) in the vicinity of a singular point consider the point as a mathematical one (having no linear dimensions). The reliability of the solution obtained by such methods is valid only outside a small vicinity of the singular point, because the macroscopic equations become incorrect and microscopic ones have to be used to describe the SSS in this vicinity. Also, it is impossible to set constraint or to formulate solutions in stress-strain terms for a mathematical point. These problems do not arise if the singular point is identified with the representative volume of material of the structure studied. In authors' opinion, this approach is consistent with the postulates of continuum mechanics. In this case, the formulation of constraints at a singular point and their investigation becomes an independent problem of mechanics for bodies with singularities. This method was used to explore constraints at an internal singular point (representative volume) of a compound wedge and a compound rib. It is shown that, in addition to the constraints given in the classical approach, there are also constraints depending on the macroscopic parameters of constituent materials. These constraints turn the problems of deformable bodies with an internal singular point into nonclassical ones. Combinations of material parameters determine the number of additional constraints and the critical stress state at the singular point. Results of this research can be used in the mechanics of composite materials and fracture mechanics and in studying stress concentrations in composite structural elements.

  2. Robust iterative closest point algorithm based on global reference point for rotation invariant registration.

    PubMed

    Du, Shaoyi; Xu, Yiting; Wan, Teng; Hu, Huaizhong; Zhang, Sirui; Xu, Guanglin; Zhang, Xuetao

    2017-01-01

    The iterative closest point (ICP) algorithm is efficient and accurate for rigid registration but it needs the good initial parameters. It is easily failed when the rotation angle between two point sets is large. To deal with this problem, a new objective function is proposed by introducing a rotation invariant feature based on the Euclidean distance between each point and a global reference point, where the global reference point is a rotation invariant. After that, this optimization problem is solved by a variant of ICP algorithm, which is an iterative method. Firstly, the accurate correspondence is established by using the weighted rotation invariant feature distance and position distance together. Secondly, the rigid transformation is solved by the singular value decomposition method. Thirdly, the weight is adjusted to control the relative contribution of the positions and features. Finally this new algorithm accomplishes the registration by a coarse-to-fine way whatever the initial rotation angle is, which is demonstrated to converge monotonically. The experimental results validate that the proposed algorithm is more accurate and robust compared with the original ICP algorithm.

  3. Robust iterative closest point algorithm based on global reference point for rotation invariant registration

    PubMed Central

    Du, Shaoyi; Xu, Yiting; Wan, Teng; Zhang, Sirui; Xu, Guanglin; Zhang, Xuetao

    2017-01-01

    The iterative closest point (ICP) algorithm is efficient and accurate for rigid registration but it needs the good initial parameters. It is easily failed when the rotation angle between two point sets is large. To deal with this problem, a new objective function is proposed by introducing a rotation invariant feature based on the Euclidean distance between each point and a global reference point, where the global reference point is a rotation invariant. After that, this optimization problem is solved by a variant of ICP algorithm, which is an iterative method. Firstly, the accurate correspondence is established by using the weighted rotation invariant feature distance and position distance together. Secondly, the rigid transformation is solved by the singular value decomposition method. Thirdly, the weight is adjusted to control the relative contribution of the positions and features. Finally this new algorithm accomplishes the registration by a coarse-to-fine way whatever the initial rotation angle is, which is demonstrated to converge monotonically. The experimental results validate that the proposed algorithm is more accurate and robust compared with the original ICP algorithm. PMID:29176780

  4. N-point functions in rolling tachyon background

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jokela, Niko; Keski-Vakkuri, Esko; Department of Physics, P.O. Box 64, FIN-00014, University of Helsinki

    2009-04-15

    We study n-point boundary correlation functions in timelike boundary Liouville theory, relevant for open string multiproduction by a decaying unstable D brane. We give an exact result for the one-point function of the tachyon vertex operator and show that it is consistent with a previously proposed relation to a conserved charge in string theory. We also discuss when the one-point amplitude vanishes. Using a straightforward perturbative expansion, we find an explicit expression for a tachyon n-point amplitude for all n, however the result is still a toy model. The calculation uses a new asymptotic approximation for Toeplitz determinants, derived bymore » relating the system to a Dyson gas at finite temperature.« less

  5. Active point out-of-plane ultrasound calibration

    NASA Astrophysics Data System (ADS)

    Cheng, Alexis; Guo, Xiaoyu; Zhang, Haichong K.; Kang, Hyunjae; Etienne-Cummings, Ralph; Boctor, Emad M.

    2015-03-01

    Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common intraoperative medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic actuation, an ultrasound calibration process must be performed. This process recovers the rigid body transformation between a tracked marker attached to the transducer and the ultrasound image. Point-based phantoms are considered to be accurate, but their calibration framework assumes that the point is in the image plane. In this work, we present the use of an active point phantom and a calibration framework that accounts for the elevational uncertainty of the point. Given the lateral and axial position of the point in the ultrasound image, we approximate a circle in the axial-elevational plane with a radius equal to the axial position. The standard approach transforms all of the imaged points to be a single physical point. In our approach, we minimize the distances between the circular subsets of each image, with them ideally intersecting at a single point. We simulated in noiseless and noisy cases, presenting results on out-of-plane estimation errors, calibration estimation errors, and point reconstruction precision. We also performed an experiment using a robot arm as the tracker, resulting in a point reconstruction precision of 0.64mm.

  6. Non-rigid point set registration of curves: registration of the superficial vessel centerlines of the brain

    NASA Astrophysics Data System (ADS)

    Marreiros, Filipe M. M.; Wang, Chunliang; Rossitti, Sandro; Smedby, Örjan

    2016-03-01

    In this study we present a non-rigid point set registration for 3D curves (composed by 3D set of points). The method was evaluated in the task of registration of 3D superficial vessels of the brain where it was used to match vessel centerline points. It consists of a combination of the Coherent Point Drift (CPD) and the Thin-Plate Spline (TPS) semilandmarks. The CPD is used to perform the initial matching of centerline 3D points, while the semilandmark method iteratively relaxes/slides the points. For the evaluation, a Magnetic Resonance Angiography (MRA) dataset was used. Deformations were applied to the extracted vessels centerlines to simulate brain bulging and sinking, using a TPS deformation where a few control points were manipulated to obtain the desired transformation (T1). Once the correspondences are known, the corresponding points are used to define a new TPS deformation(T2). The errors are measured in the deformed space, by transforming the original points using T1 and T2 and measuring the distance between them. To simulate cases where the deformed vessel data is incomplete, parts of the reference vessels were cut and then deformed. Furthermore, anisotropic normally distributed noise was added. The results show that the error estimates (root mean square error and mean error) are below 1 mm, even in the presence of noise and incomplete data.

  7. Providing HIV results via SMS one day after testing: more popular than rapid point-of-care tests.

    PubMed

    Davies, Stephen C; Koh, Andrew; Lindsay, Heather E; Fulton, Richard B; Fernando, Suran L

    2017-06-01

    An inner Sydney sexual health service introduced the option to gay and bisexual men of receiving a negative HIV result by SMS to mobile phone one business day after venipuncture (rapid SMS). Men could also choose one of the other options: a point-of-care-test (POCT), by phone, or in-person (clinicians could also require in-person). We followed-up patients choosing the rapid SMS method to ascertain their satisfaction. During 12 months, 473 men had 591 HIV tests. Of these tests, 5.4% were POCTs, 9.1% were in-person, 24% were by phone, and 62% were rapid SMS. HIV POCTs declined from being 22% of result methods in the pre-study period to 5.4% during the rapid SMS intervention period (odds ratio 0.20, 95% CI 0.13-0.32, P < 0.0001). Phone/in-person results declined from 78% to 33% (odds ratio 0.14, 95% CI 0.10-0.20, P < 0.0001). SMS was sent by the next business day in 95% of cases; 96% of men were satisfied; and 95% would choose this method for their next test. Of 77 men who previously had an HIV POCT, 56 (73%) elected a rapid SMS result rather than having another POCT. The higher accuracy of conventional serology was commonly expressed as the reason for choosing rapid SMS for results.

  8. First Point-Spread Function and X-Ray Phase Contrast Imaging Results with an 88-mm Diameter Single Crystal

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lumpkin, A. H.; Garson, A. B.; Anastasio, M. A.

    In this study, we report initial demonstrations of the use of single crystals in indirect x-ray imaging with a benchtop implementation of propagation-based (PB) x-ray phase contrast imaging. Based on single Gaussian peak fits to the x-ray images, we observed a four times smaller system point-spread function (PSF) with the 50-μm thick single crystal scintillators than with the reference polycrystalline phosphor/scintillator. Fiber-optic plate depth-of-focus and Al reflective-coating aspects are also elucidated. Guided by the results from the 25-mm diameter crystal samples, we report additionally the first results with a unique 88-mm diameter single crystal bonded to a fiber optic platemore » and coupled to the large format CCD. Both PSF and x-ray phase contrast imaging data are quantified and presented.« less

  9. Point Cloud Management Through the Realization of the Intelligent Cloud Viewer Software

    NASA Astrophysics Data System (ADS)

    Costantino, D.; Angelini, M. G.; Settembrini, F.

    2017-05-01

    The paper presents a software dedicated to the elaboration of point clouds, called Intelligent Cloud Viewer (ICV), made in-house by AESEI software (Spin-Off of Politecnico di Bari), allowing to view point cloud of several tens of millions of points, also on of "no" very high performance systems. The elaborations are carried out on the whole point cloud and managed by means of the display only part of it in order to speed up rendering. It is designed for 64-bit Windows and is fully written in C ++ and integrates different specialized modules for computer graphics (Open Inventor by SGI, Silicon Graphics Inc), maths (BLAS, EIGEN), computational geometry (CGAL, Computational Geometry Algorithms Library), registration and advanced algorithms for point clouds (PCL, Point Cloud Library), advanced data structures (BOOST, Basic Object Oriented Supporting Tools), etc. ICV incorporates a number of features such as, for example, cropping, transformation and georeferencing, matching, registration, decimation, sections, distances calculation between clouds, etc. It has been tested on photographic and TLS (Terrestrial Laser Scanner) data, obtaining satisfactory results. The potentialities of the software have been tested by carrying out the photogrammetric survey of the Castel del Monte which was already available in previous laser scanner survey made from the ground by the same authors. For the aerophotogrammetric survey has been adopted a flight height of approximately 1000ft AGL (Above Ground Level) and, overall, have been acquired over 800 photos in just over 15 minutes, with a covering not less than 80%, the planned speed of about 90 knots.

  10. Do High Dynamic Range threatments improve the results of Structure from Motion approaches in Geomorphology?

    NASA Astrophysics Data System (ADS)

    Gómez-Gutiérrez, Álvaro; Juan de Sanjosé-Blasco, José; Schnabel, Susanne; de Matías-Bejarano, Javier; Pulido-Fernández, Manuel; Berenguer-Sempere, Fernando

    2015-04-01

    In this work, the hypothesis of improving 3D models obtained with Structure from Motion (SfM) approaches using images pre-processed by High Dynamic Range (HDR) techniques is tested. Photographs of the Veleta Rock Glacier in Spain were captured with different exposure values (EV0, EV+1 and EV-1), two focal lengths (35 and 100 mm) and under different weather conditions for the years 2008, 2009, 2011, 2012 and 2014. HDR images were produced using the different EV steps within Fusion F.1 software. Point clouds were generated using commercial and free available SfM software: Agisoft Photoscan and 123D Catch. Models Obtained using pre-processed images and non-preprocessed images were compared in a 3D environment with a benchmark 3D model obtained by means of a Terrestrial Laser Scanner (TLS). A total of 40 point clouds were produced, georeferenced and compared. Results indicated that for Agisoft Photoscan software differences in the accuracy between models obtained with pre-processed and non-preprocessed images were not significant from a statistical viewpoint. However, in the case of the free available software 123D Catch, models obtained using images pre-processed by HDR techniques presented a higher point density and were more accurate. This tendency was observed along the 5 studied years and under different capture conditions. More work should be done in the near future to corroborate whether the results of similar software packages can be improved by HDR techniques (e.g. ARC3D, Bundler and PMVS2, CMP SfM, Photosynth and VisualSFM).

  11. 2+1 flavor lattice QCD toward the physical point

    NASA Astrophysics Data System (ADS)

    Aoki, S.; Ishikawa, K.-I.; Ishizuka, N.; Izubuchi, T.; Kadoh, D.; Kanaya, K.; Kuramashi, Y.; Namekawa, Y.; Okawa, M.; Taniguchi, Y.; Ukawa, A.; Ukita, N.; Yoshié, T.

    2009-02-01

    We present the first results of the PACS-CS project which aims to simulate 2+1 flavor lattice QCD on the physical point with the nonperturbatively O(a)-improved Wilson quark action and the Iwasaki gauge action. Numerical simulations are carried out at β=1.9, corresponding to the lattice spacing of a=0.0907(13)fm, on a 323×64 lattice with the use of the domain-decomposed HMC algorithm to reduce the up-down quark mass. Further algorithmic improvements make possible the simulation whose up-down quark mass is as light as the physical value. The resulting pseudoscalar meson masses range from 702 MeV down to 156 MeV, which clearly exhibit the presence of chiral logarithms. An analysis of the pseudoscalar meson sector with SU(3) chiral perturbation theory reveals that the next-to-leading order corrections are large at the physical strange quark mass. In order to estimate the physical up-down quark mass, we employ the SU(2) chiral analysis expanding the strange quark contributions analytically around the physical strange quark mass. The SU(2) low energy constants lmacr 3 and lmacr 4 are comparable with the recent estimates by other lattice QCD calculations. We determine the physical point together with the lattice spacing employing mπ, mK and mΩ as input. The hadron spectrum extrapolated to the physical point shows an agreement with the experimental values at a few % level of statistical errors, albeit there remain possible cutoff effects. We also find that our results of fπ, fK and their ratio, where renormalization is carries out perturbatively at one loop, are compatible with the experimental values. For the physical quark masses we obtain mudM Smacr and msM Smacr extracted from the axial-vector Ward-Takahashi identity with the perturbative renormalization factors. We also briefly discuss the results for the static quark potential.

  12. Topological phases protected by point group symmetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Song, Hao; Huang, Sheng -Jie; Fu, Liang

    We consider symmetry-protected topological (SPT) phases with crystalline point group symmetry, dubbed point group SPT (pgSPT) phases. We show that such phases can be understood in terms of lower-dimensional topological phases with on-site symmetry and that they can be constructed as stacks and arrays of these lower-dimensional states. This provides the basis for a general framework to classify and characterize bosonic and fermionic pgSPT phases, which can be applied for arbitrary crystalline point group symmetry and in arbitrary spatial dimensions. We develop and illustrate this framework by means of a few examples, focusing on three-dimensional states. We classify bosonic pgSPTmore » phases and fermionic topological crystalline superconductors with Z P 2 (reflection) symmetry, electronic topological crystalline insulators (TCIs) with U(1)×Z P 2 symmetry, and bosonic pgSPT phases with C 2v symmetry, which is generated by two perpendicular mirror reflections. We also study surface properties, with a focus on gapped, topologically ordered surface states. For electronic TCIs, we find a Z 8 × Z 2 classification, where the Z 8 corresponds to known states obtained from noninteracting electrons, and the Z 2 corresponds to a “strongly correlated” TCI that requires strong interactions in the bulk. Lastly, our approach may also point the way toward a general theory of symmetry-enriched topological phases with crystalline point group symmetry.« less

  13. Comparison Between One-Point Calibration and Two-Point Calibration Approaches in a Continuous Glucose Monitoring Algorithm

    PubMed Central

    Mahmoudi, Zeinab; Johansen, Mette Dencker; Christiansen, Jens Sandahl

    2014-01-01

    Background: The purpose of this study was to investigate the effect of using a 1-point calibration approach instead of a 2-point calibration approach on the accuracy of a continuous glucose monitoring (CGM) algorithm. Method: A previously published real-time CGM algorithm was compared with its updated version, which used a 1-point calibration instead of a 2-point calibration. In addition, the contribution of the corrective intercept (CI) to the calibration performance was assessed. Finally, the sensor background current was estimated real-time and retrospectively. The study was performed on 132 type 1 diabetes patients. Results: Replacing the 2-point calibration with the 1-point calibration improved the CGM accuracy, with the greatest improvement achieved in hypoglycemia (18.4% median absolute relative differences [MARD] in hypoglycemia for the 2-point calibration, and 12.1% MARD in hypoglycemia for the 1-point calibration). Using 1-point calibration increased the percentage of sensor readings in zone A+B of the Clarke error grid analysis (EGA) in the full glycemic range, and also enhanced hypoglycemia sensitivity. Exclusion of CI from calibration reduced hypoglycemia accuracy, while slightly increased euglycemia accuracy. Both real-time and retrospective estimation of the sensor background current suggest that the background current can be considered zero in the calibration of the SCGM1 sensor. Conclusions: The sensor readings calibrated with the 1-point calibration approach indicated to have higher accuracy than those calibrated with the 2-point calibration approach. PMID:24876420

  14. Accuracy assessment of the Precise Point Positioning method applied for surveys and tracking moving objects in GIS environment

    NASA Astrophysics Data System (ADS)

    Ilieva, Tamara; Gekov, Svetoslav

    2017-04-01

    The Precise Point Positioning (PPP) method gives the users the opportunity to determine point locations using a single GNSS receiver. The accuracy of the determined by PPP point locations is better in comparison to the standard point positioning, due to the precise satellite orbit and clock corrections that are developed and maintained by the International GNSS Service (IGS). The aim of our current research is the accuracy assessment of the PPP method applied for surveys and tracking moving objects in GIS environment. The PPP data is collected by using preliminary developed by us software application that allows different sets of attribute data for the measurements and their accuracy to be used. The results from the PPP measurements are directly compared within the geospatial database to different other sets of terrestrial data - measurements obtained by total stations, real time kinematic and static GNSS.

  15. Towards 3D Matching of Point Clouds Derived from Oblique and Nadir Airborne Imagery

    NASA Astrophysics Data System (ADS)

    Zhang, Ming

    Because of the low-expense high-efficient image collection process and the rich 3D and texture information presented in the images, a combined use of 2D airborne nadir and oblique images to reconstruct 3D geometric scene has a promising market for future commercial usage like urban planning or first responders. The methodology introduced in this thesis provides a feasible way towards fully automated 3D city modeling from oblique and nadir airborne imagery. In this thesis, the difficulty of matching 2D images with large disparity is avoided by grouping the images first and applying the 3D registration afterward. The procedure starts with the extraction of point clouds using a modified version of the RIT 3D Extraction Workflow. Then the point clouds are refined by noise removal and surface smoothing processes. Since the point clouds extracted from different image groups use independent coordinate systems, there are translation, rotation and scale differences existing. To figure out these differences, 3D keypoints and their features are extracted. For each pair of point clouds, an initial alignment and a more accurate registration are applied in succession. The final transform matrix presents the parameters describing the translation, rotation and scale requirements. The methodology presented in the thesis has been shown to behave well for test data. The robustness of this method is discussed by adding artificial noise to the test data. For Pictometry oblique aerial imagery, the initial alignment provides a rough alignment result, which contains a larger offset compared to that of test data because of the low quality of the point clouds themselves, but it can be further refined through the final optimization. The accuracy of the final registration result is evaluated by comparing it to the result obtained from manual selection of matched points. Using the method introduced, point clouds extracted from different image groups could be combined with each other to build a

  16. A numerical analysis on forming limits during spiral and concentric single point incremental forming

    NASA Astrophysics Data System (ADS)

    Gipiela, M. L.; Amauri, V.; Nikhare, C.; Marcondes, P. V. P.

    2017-01-01

    Sheet metal forming is one of the major manufacturing industries, which are building numerous parts for aerospace, automotive and medical industry. Due to the high demand in vehicle industry and environmental regulations on less fuel consumption on other hand, researchers are innovating new methods to build these parts with energy efficient sheet metal forming process instead of conventionally used punch and die to form the parts to achieve the lightweight parts. One of the most recognized manufacturing process in this category is Single Point Incremental Forming (SPIF). SPIF is the die-less sheet metal forming process in which the single point tool incrementally forces any single point of sheet metal at any process time to plastic deformation zone. In the present work, finite element method (FEM) is applied to analyze the forming limits of high strength low alloy steel formed by single point incremental forming (SPIF) by spiral and concentric tool path. SPIF numerical simulations were model with 24 and 29 mm cup depth, and the results were compare with Nakajima results obtained by experiments and FEM. It was found that the cup formed with Nakajima tool failed at 24 mm while cups formed by SPIF surpassed the limit for both depths with both profiles. It was also notice that the strain achieved in concentric profile are lower than that in spiral profile.

  17. Nonlocal electron-phonon coupling in the pentacene crystal: Beyond the Γ-point approximation

    NASA Astrophysics Data System (ADS)

    Yi, Yuanping; Coropceanu, Veaceslav; Brédas, Jean-Luc

    2012-10-01

    There is currently increasing interest in understanding the impact of the nonlocal (Peierls-type) electron-phonon mechanism on charge transport in organic molecular semiconductors. Most estimates of the non-local coupling constants reported in the literature are based on the Γ-point phonon modes. Here, the influence of phonon modes spanning the entire Brillouin zone (phonon dispersion) on the nonlocal electron-phonon couplings is investigated for the pentacene crystal. The phonon modes are obtained by using a supercell approach. The results underline that the overall nonlocal couplings are substantially underestimated by calculations taking sole account of the phonons at the Γ point of the unit cell. The variance of the transfer integrals based on Γ-point normal-mode calculations at room temperature is underestimated in some cases by 40% for herringbone-type dimers and by over 80% for cofacial dimers. Our calculations show that the overall coupling is somewhat larger for holes than for electrons. The results also suggest that the interactions of charge carriers (both electrons and holes) with acoustic and optical phonons are comparable. Therefore, an adequate description of the charge-transport properties in pentacene and similar systems requires that these two electron-phonon coupling mechanisms be treated on the same footing.

  18. Estimation of the auto frequency response function at unexcited points using dummy masses

    NASA Astrophysics Data System (ADS)

    Hosoya, Naoki; Yaginuma, Shinji; Onodera, Hiroshi; Yoshimura, Takuya

    2015-02-01

    If structures with complex shapes have space limitations, vibration tests using an exciter or impact hammer for the excitation are difficult. Although measuring the auto frequency response function at an unexcited point may not be practical via a vibration test, it can be obtained by assuming that the inertia acting on a dummy mass is an external force on the target structure upon exciting a different excitation point. We propose a method to estimate the auto frequency response functions at unexcited points by attaching a small mass (dummy mass), which is comparable to the accelerometer mass. The validity of the proposed method is demonstrated by comparing the auto frequency response functions estimated at unexcited points in a beam structure to those obtained from numerical simulations. We also consider random measurement errors by finite element analysis and vibration tests, but not bias errors. Additionally, the applicability of the proposed method is demonstrated by applying it to estimate the auto frequency response function of the lower arm in a car suspension.

  19. Chiral Tricritical Point: A New Universality Class in Dirac Systems

    NASA Astrophysics Data System (ADS)

    Yin, Shuai; Jian, Shao-Kai; Yao, Hong

    2018-05-01

    Tricriticality, as a sister of criticality, is a fundamental and absorbing issue in condensed-matter physics. It has been verified that the bosonic Wilson-Fisher universality class can be changed by gapless fermionic modes at criticality. However, the counterpart phenomena at tricriticality have rarely been explored. In this Letter, we study a model in which a tricritical Ising model is coupled to massless Dirac fermions. We find that the massless Dirac fermions result in the emergence of a new tricritical point, which we refer to as the chiral tricritical point (CTP), at the phase boundary between the Dirac semimetal and the charge-density wave insulator. From functional renormalization group analysis of the effective action, we obtain the critical behaviors of the CTP, which are qualitatively distinct from both the tricritical Ising universality and the chiral Ising universality. We further extend the calculations of the chiral tricritical behaviors of Ising spins to the case of Heisenberg spins. The experimental relevance of the CTP in two-dimensional Dirac semimetals is also discussed.

  20. Precision Linear Actuator for Space Interferometry Mission (SIM) Siderostat Pointing

    NASA Technical Reports Server (NTRS)

    Cook, Brant; Braun, David; Hankins, Steve; Koenig, John; Moore, Don

    2008-01-01

    'SIM PlanetQuest will exploit the classical measuring tool of astrometry (interferometry) with unprecedented precision to make dramatic advances in many areas of astronomy and astrophysics'(1). In order to obtain interferometric data two large steerable mirrors, or Siderostats, are used to direct starlight into the interferometer. A gimbaled mechanism actuated by linear actuators is chosen to meet the unprecedented pointing and angle tracking requirements of SIM. A group of JPL engineers designed, built, and tested a linear ballscrew actuator capable of performing submicron incremental steps for 10 years of continuous operation. Precise, zero backlash, closed loop pointing control requirements, lead the team to implement a ballscrew actuator with a direct drive DC motor and a precision piezo brake. Motor control commutation using feedback from a precision linear encoder on the ballscrew output produced an unexpected incremental step size of 20 nm over a range of 120 mm, yielding a dynamic range of 6,000,000:1. The results prove linear nanometer positioning requires no gears, levers, or hydraulic converters. Along the way many lessons have been learned and will subsequently be shared.

  1. Calculation of 3D Coordinates of a Point on the Basis of a Stereoscopic System

    NASA Astrophysics Data System (ADS)

    Mussabayev, R. R.; Kalimoldayev, M. N.; Amirgaliyev, Ye. N.; Tairova, A. T.; Mussabayev, T. R.

    2018-05-01

    The solution of three-dimensional (3D) coordinate calculation task for a material point is considered. Two flat images (a stereopair) which correspond to the left and to the right viewpoints of a 3D scene are used for this purpose. The stereopair is obtained using two cameras with parallel optical axes. The analytical formulas for calculating 3D coordinates of a material point in the scene were obtained on the basis of analysis of the stereoscopic system optical and geometrical schemes. The detailed presentation of the algorithmic and hardware realization of the given method was discussed with the the practical. The practical module was recommended for the determination of the optical system unknown parameters. The series of experimental investigations were conducted for verification of theoretical results. During these experiments the minor inaccuracies were occurred by space distortions in the optical system and by it discrecity. While using the high quality stereoscopic system, the existing calculation inaccuracy enables to apply the given method for the wide range of practical tasks.

  2. Lung motion estimation using dynamic point shifting: An innovative model based on a robust point matching algorithm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yi, Jianbing, E-mail: yijianbing8@163.com; Yang, Xuan, E-mail: xyang0520@263.net; Li, Yan-Ran, E-mail: lyran@szu.edu.cn

    2015-10-15

    Purpose: Image-guided radiotherapy is an advanced 4D radiotherapy technique that has been developed in recent years. However, respiratory motion causes significant uncertainties in image-guided radiotherapy procedures. To address these issues, an innovative lung motion estimation model based on a robust point matching is proposed in this paper. Methods: An innovative robust point matching algorithm using dynamic point shifting is proposed to estimate patient-specific lung motion during free breathing from 4D computed tomography data. The correspondence of the landmark points is determined from the Euclidean distance between the landmark points and the similarity between the local images that are centered atmore » points at the same time. To ensure that the points in the source image correspond to the points in the target image during other phases, the virtual target points are first created and shifted based on the similarity between the local image centered at the source point and the local image centered at the virtual target point. Second, the target points are shifted by the constrained inverse function mapping the target points to the virtual target points. The source point set and shifted target point set are used to estimate the transformation function between the source image and target image. Results: The performances of the authors’ method are evaluated on two publicly available DIR-lab and POPI-model lung datasets. For computing target registration errors on 750 landmark points in six phases of the DIR-lab dataset and 37 landmark points in ten phases of the POPI-model dataset, the mean and standard deviation by the authors’ method are 1.11 and 1.11 mm, but they are 2.33 and 2.32 mm without considering image intensity, and 1.17 and 1.19 mm with sliding conditions. For the two phases of maximum inhalation and maximum exhalation in the DIR-lab dataset with 300 landmark points of each case, the mean and standard deviation of target registration errors

  3. 2. HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. HALF DOME AT CENTER REAR. LOOKING NNE. GIS N-37 43 44.3 / W-119 34 14.1 - Glacier Point Road, Between Chinquapin Flat & Glacier Point, Yosemite Village, Mariposa County, CA

  4. Water content estimated from point scale to plot scale

    NASA Astrophysics Data System (ADS)

    Akyurek, Z.; Binley, A. M.; Demir, G.; Abgarmi, B.

    2017-12-01

    Soil moisture controls the portioning of rainfall into infiltration and runoff. Here we investigate measurements of soil moisture using a range of techniques spanning different spatial scales. In order to understand soil water content in a test basin, 512 km2 in area, in the south of Turkey, a Cosmic Ray CRS200B soil moisture probe was installed at elevation of 1459 m and an ML3 ThetaProbe (CS 616) soil moisture sensor was established at 5cm depth used to get continuous soil moisture. Neutron count measurements were corrected for the changes in atmospheric pressure, atmospheric water vapour and intensity of incoming neutron flux. The calibration of the volumetric soil moisture was performed, from the laboratory analysis, the bulk density varies between 1.719 (g/cm3) -1.390 (g/cm3), and the dominant soil texture is silty clay loam and silt loamThe water content reflectometer was calibrated for soil-specific conditions and soil moisture estimates were also corrected with respect to soil temperature. In order to characterize the subsurface, soil electrical resistivity tomography was used. Wenner and Schlumberger array geometries were used with electrode spacing varied from 1m- 5 m along 40 m and 200 m profiles. From the inversions of ERT data it is apparent that within 50 m distance from the CRS200B, the soil is moderately resistive to a depth of 2m and more conductive at greater depths. At greater distances from the CRS200B, the ERT results indicate more resistive soils. In addition to the ERT surveys, ground penetrating radar surveys using a common mid-point configuration was used with 200MHz antennas. The volumetric soil moisture obtained from GPR appears to overestimate those based on TDR observations. The values obtained from CS616 (at a point scale) and CRS200B (at a mesoscale) are compared with the values obtained at a plot scale. For the field study dates (20-22.06.2017) the volumetric moisture content obtained from CS616 were 25.14%, 25.22% and 25

  5. Point defects in thorium nitride: A first-principles study

    NASA Astrophysics Data System (ADS)

    Pérez Daroca, D.; Llois, A. M.; Mosca, H. O.

    2016-11-01

    Thorium and its compounds (carbides and nitrides) are being investigated as possible materials to be used as nuclear fuels for Generation-IV reactors. As a first step in the research of these materials under irradiation, we study the formation energies and stability of point defects in thorium nitride by means of first-principles calculations within the framework of density functional theory. We focus on vacancies, interstitials, Frenkel pairs and Schottky defects. We found that N and Th vacancies have almost the same formation energy and that the most energetically favorable defects of all studied in this work are N interstitials. These kind of results for ThN, to the best authors' knowledge, have not been obtained previously, neither experimentally, nor theoretically.

  6. A point-by-point multi-scale surface temperature reconstruction method and tests by pseudo proxy experiments

    NASA Astrophysics Data System (ADS)

    Chen, X.

    2016-12-01

    This study present a multi-scale approach combining Mode Decomposition and Variance Matching (MDVM) method and basic process of Point-by-Point Regression (PPR) method. Different from the widely applied PPR method, the scanning radius for each grid box, were re-calculated considering the impact from topography (i.e. mean altitudes and fluctuations). Thus, appropriate proxy records were selected to be candidates for reconstruction. The results of this multi-scale methodology could not only provide the reconstructed gridded temperature, but also the corresponding uncertainties of the four typical timescales. In addition, this method can bring in another advantage that spatial distribution of the uncertainty for different scales could be quantified. To interpreting the necessity of scale separation in calibration, with proxy records location over Eastern Asia, we perform two sets of pseudo proxy experiments (PPEs) based on different ensembles of climate model simulation. One consist of 7 simulated results by 5 models (BCC-CSM1-1, CSIRO-MK3L-1-2, HadCM3, MPI-ESM-P, and Giss-E2-R) of the "past1000" simulation from Coupled Model Intercomparison Project Phase 5. The other is based on the simulations of Community Earth System Model Last Millennium Ensemble (CESM-LME). The pseudo-records network were obtained by adding the white noise with signal-to-noise ratio (SNR) increasing from 0.1 to 1.0 to the simulated true state and the locations mainly followed the PAGES-2k network in Asia. Totally, 400 years (1601-2000) simulation was used for calibration and 600 years (1001-1600) for verification. The reconstructed results were evaluated by three metrics 1) root mean squared error (RMSE), 2) correlation and 3) reduction of error (RE) score. The PPE verification results have shown that, in comparison with ordinary linear calibration method (variance matching), the RMSE and RE score of PPR-MDVM are improved, especially for the area with sparse proxy records. To be noted, in some

  7. Point-by-point model calculation of the prompt neutron multiplicity distribution ν(A) in the incident neutron energy range of multi-chance fission

    NASA Astrophysics Data System (ADS)

    Tudora, Anabella; Hambsch, Franz-Josef; Tobosaru, Viorel

    2017-09-01

    Prompt neutron multiplicity distributions ν(A) are required for prompt emission correction of double energy (2E) measurements of fission fragments to determine pre-neutron fragment properties. The lack of experimental ν(A) data especially at incident neutron energies (En) where the multi-chance fission occurs impose the use of ν(A) predicted by models. The Point-by-Point model of prompt emission is able to provide the individual ν(A) of the compound nuclei of the main and secondary nucleus chains undergoing fission at a given En. The total ν(A) is obtained by averaging these individual ν(A) over the probabilities of fission chances (expressed as total and partial fission cross-section ratios). An indirect validation of the total ν(A) results is proposed. At high En, above 70 MeV, the PbP results of individual ν(A) of the first few nuclei of the main and secondary nucleus chains exhibit an almost linear increase. This shape is explained by the damping of shell effects entering the super-fluid expression of the level density parameters. They tend to approach the asymptotic values for most of the fragments. This fact leads to a smooth and almost linear increase of fragment excitation energy with the mass number that is reflected in a smooth and almost linear behaviour of ν(A).

  8. Hydrogeologic reconnaissance of Poro Point and vicinity, Luzon Island, Philippines

    USGS Publications Warehouse

    Worts, George Frank

    1964-01-01

    In 1961 a reconnaissance of the geology and ground-water hydrology of Poro Point, on the west coast of Luzon Island, Philippines, was made on behalf of the U.S. Department of the Navy. Poro Point, which marks the northern end of Lingayen Gulf, is about half a mile wide and projects northwestward about 2 miles into the China Sea. The point is underlain by coralline limestone of probable Pleistocene age. The aquifer system consists of a fresh-water lens floating on salt water within the coralline limestone. Several tube wells obtain fresh water from the lens, but in May, at the end of the 6-month dry season during which rainfall totals only 40 inches, the water becomes brackish. 'Skimming wells' are considered the best method of obtaining fresh water from the lens, whose annual range in average thickness is probably 25 to 40 feet. Recharge is about 2,000-3,000 acre-feet per year and is derived wholly from precipitation during the 6-month wet season in which rainfall totals about 92 inches. The approximate amount of ground water stored in the fresh-water lens ranges from about 3,000 acre-feet at the end of the dry season to about 5,000 acre-feet at the end of the wet season. Most of the ground water is discharged through seeps and submarine springs around Poro Point; pumpage in 1961 was only about 100 acre-feet.

  9. Measurement Uncertainty of Dew-Point Temperature in a Two-Pressure Humidity Generator

    NASA Astrophysics Data System (ADS)

    Martins, L. Lages; Ribeiro, A. Silva; Alves e Sousa, J.; Forbes, Alistair B.

    2012-09-01

    This article describes the measurement uncertainty evaluation of the dew-point temperature when using a two-pressure humidity generator as a reference standard. The estimation of the dew-point temperature involves the solution of a non-linear equation for which iterative solution techniques, such as the Newton-Raphson method, are required. Previous studies have already been carried out using the GUM method and the Monte Carlo method but have not discussed the impact of the approximate numerical method used to provide the temperature estimation. One of the aims of this article is to take this approximation into account. Following the guidelines presented in the GUM Supplement 1, two alternative approaches can be developed: the forward measurement uncertainty propagation by the Monte Carlo method when using the Newton-Raphson numerical procedure; and the inverse measurement uncertainty propagation by Bayesian inference, based on prior available information regarding the usual dispersion of values obtained by the calibration process. The measurement uncertainties obtained using these two methods can be compared with previous results. Other relevant issues concerning this research are the broad application to measurements that require hygrometric conditions obtained from two-pressure humidity generators and, also, the ability to provide a solution that can be applied to similar iterative models. The research also studied the factors influencing both the use of the Monte Carlo method (such as the seed value and the convergence parameter) and the inverse uncertainty propagation using Bayesian inference (such as the pre-assigned tolerance, prior estimate, and standard deviation) in terms of their accuracy and adequacy.

  10. Public Support for Family Smoking Prevention and Tobacco Control Act Point-of-Sale Provisions: Results of a National Study

    PubMed Central

    Emery, Sherry L.; Ennett, Susan; McNaughton Reyes, Heath Luz; Scott, John C.; Ribisl, Kurt M.

    2015-01-01

    Objectives. We assessed public and smoker support for enacted and potential point-of-sale (POS) tobacco-control policies under the Family Smoking Prevention and Tobacco Control Act. Methods. We surveyed a US nationally representative sample of 17 507 respondents (6595 smokers) in January through February 2013, and used linear regression to calculate weighted point estimates and identify factors associated with support for POS policies among adults and smokers. Results. Overall, nonsmokers were more supportive than were smokers. Regardless of smoking status, African Americans, Hispanics, women, and those of older ages were more supportive than White, male, and younger respondents, respectively. Policy support varied by provision. More than 80% of respondents supported minors’ access restrictions and more than 45% supported graphic warnings. Support was lowest for plain packaging (23%), black-and-white advertising (26%), and a ban on menthol cigarettes (36%). Conclusions. Public support for marketing and POS provisions is low relative to other areas of tobacco control. Tobacco-control advocates and the Food and Drug Administration should build on existing levels of public support to promote and maintain evidence-based, but controversial, policy changes in the retail environment. PMID:26270303

  11. Financial Literacy of 15-Year-Olds: Results from PISA 2012. Data Point. NCES 2014-102

    ERIC Educational Resources Information Center

    Gonzales, Patrick; Kelly, Dana

    2014-01-01

    This Data Point uses data from the 2012 administration of the Program for International Student Assessment (PISA) financial literacy assessment. PISA is an international assessment that measures 15-year-old students' reading, mathematics, and science literacy and, in 2012, general problem solving and financial literacy. PISA is coordinated by the…

  12. Structure of Lie point and variational symmetry algebras for a class of odes

    NASA Astrophysics Data System (ADS)

    Ndogmo, J. C.

    2018-04-01

    It is known for scalar ordinary differential equations, and for systems of ordinary differential equations of order not higher than the third, that their Lie point symmetry algebras is of maximal dimension if and only if they can be reduced by a point transformation to the trivial equation y(n)=0. For arbitrary systems of ordinary differential equations of order n ≥ 3 reducible by point transformations to the trivial equation, we determine the complete structure of their Lie point symmetry algebras as well as that for their variational, and their divergence symmetry algebras. As a corollary, we obtain the maximal dimension of the Lie point symmetry algebra for any system of linear or nonlinear ordinary differential equations.

  13. Small-aperture seismic array data processing using a representation of seismograms at zero-crossing points

    NASA Astrophysics Data System (ADS)

    Brokešová, Johana; Málek, Jiří

    2018-07-01

    A new method for representing seismograms by using zero-crossing points is described. This method is based on decomposing a seismogram into a set of quasi-harmonic components and, subsequently, on determining the precise zero-crossing times of these components. An analogous approach can be applied to determine extreme points that represent the zero-crossings of the first time derivative of the quasi-harmonics. Such zero-crossing and/or extreme point seismogram representation can be used successfully to reconstruct single-station seismograms, but the main application is to small-aperture array data analysis to which standard methods cannot be applied. The precise times of the zero-crossing and/or extreme points make it possible to determine precise time differences across the array used to retrieve the parameters of a plane wave propagating across the array, namely, its backazimuth and apparent phase velocity along the Earth's surface. The applicability of this method is demonstrated using two synthetic examples. In the real-data example from the Příbram-Háje array in central Bohemia (Czech Republic) for the Mw 6.4 Crete earthquake of October 12, 2013, this method is used to determine the phase velocity dispersion of both Rayleigh and Love waves. The resulting phase velocities are compared with those obtained by employing the seismic plane-wave rotation-to-translation relations. In this approach, the phase velocity is calculated by obtaining the amplitude ratios between the rotation and translation components. Seismic rotations are derived from the array data, for which the small aperture is not only an advantage but also an applicability condition.

  14. Realization of the Gallium Triple Point at NMIJ/AIST

    NASA Astrophysics Data System (ADS)

    Nakano, T.; Tamura, O.; Sakurai, H.

    2008-02-01

    The triple point of gallium has been realized by a calorimetric method using capsule-type standard platinum resistance thermometers (CSPRTs) and a small glass cell containing about 97 mmol (6.8 g) of gallium with a nominal purity of 99.99999%. The melting curve shows a very flat and relatively linear dependence on 1/ F in the region from 1/ F = 1 to 1/ F = 20 with a narrow width of the melting curve within 0.1 mK. Also, a large gallium triple-point cell was fabricated for the calibration of client-owned CSPRTs. The gallium triple-point cell consists of a PTFE crucible and a PTFE cap with a re-entrant well and a small vent. The PTFE cell contains 780 g of gallium from the same source as used for the small glass cell. The PTFE cell is completely covered by a stainless-steel jacket with a valve to enable evacuation of the cell. The melting curve of the large cell shows a flat plateau that remains within 0.03 mK over 10 days and that is reproducible within 0.05 mK over 8 months. The calibrated value of a CSPRT obtained using the large cell agrees with that obtained using the small glass cell within the uncertainties of the calibrations.

  15. Correlation of the ionisation response at selected points of IC sensitive regions with SEE sensitivity parameters under pulsed laser irradiation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gordienko, A V; Mavritskii, O B; Egorov, A N

    2014-12-31

    The statistics of the ionisation response amplitude measured at selected points and their surroundings within sensitive regions of integrated circuits (ICs) under focused femtosecond laser irradiation is obtained for samples chosen from large batches of two types of ICs. A correlation between these data and the results of full-chip scanning is found for each type. The criteria for express validation of IC single-event effect (SEE) hardness based on ionisation response measurements at selected points are discussed. (laser applications and other topics in quantum electronics)

  16. Globular-cluster stars - Results of theoretical evolution and pulsation studies compared with the observations.

    NASA Technical Reports Server (NTRS)

    Iben, I., Jr.

    1971-01-01

    Survey of recently published studies on globular clusters, and comparison of stellar evolution and pulsation theory with reported observations. The theory of stellar evolution is shown to be capable of describing, in principle, the behavior of a star through all quasi-static stages. Yet, as might be expected, estimates of bulk properties obtained by comparing observations with results of pulsation and stellar atmosphere theory differ somewhat from estimates of these same properties obtained by comparing observations with results of evolution theory. A description is given of how such estimates are obtained, and suggestions are offered as to where the weak points in each theory may lie.

  17. HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. HALF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. HALF DOME AT CENTER REAR. SAME VIEW AT CA-157-2. LOOKING NNE. GIS: N-37' 43 44.3 / W-119 34 14.1 - Glacier Point Road, Between Chinquapin Flat & Glacier Point, Yosemite Village, Mariposa County, CA

  18. Dielectric function, critical points, and Rydberg exciton series of WSe2 monolayer.

    PubMed

    Diware, M S; Ganorkar, S P; Park, K; Chegal, W; Cho, H M; Cho, Y J; Kim, Y D; Kim, H

    2018-06-13

    The complex dielectric function ([Formula: see text]) of WSe 2 monolayer grown by atomic layer deposition is investigated using spectroscopic ellipsometry. Band structure parameters are obtained by standard line-shape analysis of the second-energy-derivative of [Formula: see text] spectra. The fundamental band gap is observed at 2.26 eV, corresponds to transition between valence band (VB) maximum at the K point and conduction band (CB) minimum at Q point in the Brillouin zone (BZ). Two strong so-called A and B excitonic peaks in [Formula: see text] spectra originate from vertical transitions from spin-orbit split (0.43 eV) VB to CB at K point of the BZ. Binding energies of A and B exactions are 0.71 and 0.28 eV, respectively. Well resolved five excited excitons states has been detected within the spectral region between A and B. Energy profile of the Rydberg series shows significant deviation from the hydrogenic behavior, discussed in connection with the 2D hydrogen model. Results presented here will improve our understanding about the optical response of 2D materials and will help to design better optoelectronic applications and validate theoretical considerations.

  19. Dielectric function, critical points, and Rydberg exciton series of WSe2 monolayer

    NASA Astrophysics Data System (ADS)

    Diware, M. S.; Ganorkar, S. P.; Park, K.; Chegal, W.; Cho, H. M.; Cho, Y. J.; Kim, Y. D.; Kim, H.

    2018-06-01

    The complex dielectric function () of WSe2 monolayer grown by atomic layer deposition is investigated using spectroscopic ellipsometry. Band structure parameters are obtained by standard line-shape analysis of the second-energy-derivative of spectra. The fundamental band gap is observed at 2.26 eV, corresponds to transition between valence band (VB) maximum at the K point and conduction band (CB) minimum at Q point in the Brillouin zone (BZ). Two strong so-called A and B excitonic peaks in spectra originate from vertical transitions from spin–orbit split (0.43 eV) VB to CB at K point of the BZ. Binding energies of A and B exactions are 0.71 and 0.28 eV, respectively. Well resolved five excited excitons states has been detected within the spectral region between A and B. Energy profile of the Rydberg series shows significant deviation from the hydrogenic behavior, discussed in connection with the 2D hydrogen model. Results presented here will improve our understanding about the optical response of 2D materials and will help to design better optoelectronic applications and validate theoretical considerations.

  20. Multi-point contact of the high-speed vehicle-turnout system dynamics

    NASA Astrophysics Data System (ADS)

    Ren, Zunsong

    2013-05-01

    The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn't occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system.

  1. Determining oxygen consumption rate and asphyxiation point in Chanodichthys mongolicus using an improved respirometer chamber

    NASA Astrophysics Data System (ADS)

    Geng, Longwu; Jiang, Haifeng; Tong, Guangxiang; Xu, Wei

    2017-03-01

    Knowledge of oxygen consumption rates and asphyxiation points in fish is important to determine appropriate stocking and water quality management in aquaculture. The oxygen consumption rate and asphyxiation point in Chanodichthys mongolicus were detected under laboratory conditions using an improved respirometer chamber. The results revealed that more accurate estimates can be obtained by adjusting the volume of the respirometer chamber, which may avoid system errors caused by either repeatedly adjusting fish density or selecting different equipment specifications. The oxygen consumption rate and asphyxiation point of C. mongolicus increased with increasing water temperature and decreasing fish size. Changes in the C. mongolicus oxygen consumption rate were divided into three stages at water temperatures of 11-33°C: (1) a low temperature oxygen consumption rate stage when water temperature was 11-19°C, (2) the optimum temperature oxygen consumption rate stage when water temperature was 19-23°C, and (3) a high temperature oxygen consumption rate stage when water temperature was > 27°C. The temperature quotients (Q10) obtained suggested that C. mongolicus preferred a temperature range of 19-23°C. At 19°C, C. mongolicus exhibited higher oxygen consumption rates during the day when the maximum values were observed at 10:00 and 14:00 than at night when the minimum occurred at 02:00.

  2. Effects of LiDAR point density, sampling size and height threshold on estimation accuracy of crop biophysical parameters.

    PubMed

    Luo, Shezhou; Chen, Jing M; Wang, Cheng; Xi, Xiaohuan; Zeng, Hongcheng; Peng, Dailiang; Li, Dong

    2016-05-30

    Vegetation leaf area index (LAI), height, and aboveground biomass are key biophysical parameters. Corn is an important and globally distributed crop, and reliable estimations of these parameters are essential for corn yield forecasting, health monitoring and ecosystem modeling. Light Detection and Ranging (LiDAR) is considered an effective technology for estimating vegetation biophysical parameters. However, the estimation accuracies of these parameters are affected by multiple factors. In this study, we first estimated corn LAI, height and biomass (R2 = 0.80, 0.874 and 0.838, respectively) using the original LiDAR data (7.32 points/m2), and the results showed that LiDAR data could accurately estimate these biophysical parameters. Second, comprehensive research was conducted on the effects of LiDAR point density, sampling size and height threshold on the estimation accuracy of LAI, height and biomass. Our findings indicated that LiDAR point density had an important effect on the estimation accuracy for vegetation biophysical parameters, however, high point density did not always produce highly accurate estimates, and reduced point density could deliver reasonable estimation results. Furthermore, the results showed that sampling size and height threshold were additional key factors that affect the estimation accuracy of biophysical parameters. Therefore, the optimal sampling size and the height threshold should be determined to improve the estimation accuracy of biophysical parameters. Our results also implied that a higher LiDAR point density, larger sampling size and height threshold were required to obtain accurate corn LAI estimation when compared with height and biomass estimations. In general, our results provide valuable guidance for LiDAR data acquisition and estimation of vegetation biophysical parameters using LiDAR data.

  3. The similia principle: results obtained in a cellular model system.

    PubMed

    Wiegant, Fred; Van Wijk, Roeland

    2010-01-01

    This paper describes the results of a research program focused on the beneficial effect of low dose stress conditions that were applied according to the similia principle to cells previously disturbed by more severe stress conditions. In first instance, we discuss criteria for research on the similia principle at the cellular level. Then, the homologous ('isopathic') approach is reviewed, in which the initial (high dose) stress used to disturb cellular physiology and the subsequent (low dose) stress are identical. Beneficial effects of low dose stress are described in terms of increased cellular survival capacity and at the molecular level as an increase in the synthesis of heat shock proteins (hsps). Both phenomena reflect a stimulation of the endogenous cellular self-recovery capacity. Low dose stress conditions applied in a homologous approach stimulate the synthesis of hsps and enhance survival in comparison with stressed cells that were incubated in the absence of low dose stress conditions. Thirdly, the specificity of the low dose stress condition is described where the initial (high dose) stress is different in nature from the subsequently applied (low dose) stress; the heterologous or 'heteropathic' approach. The results support the similia principle at the cellular level and add to understanding of how low dose stress conditions influence the regulatory processes underlying self-recovery. In addition, the phenomenon of 'symptom aggravation' which is also observed at the cellular level, is discussed in the context of self-recovery. Finally, the difference in efficiency between the homologous and the heterologous approach is discussed; a perspective is indicated for further research; and the relationship between studies on the similia principle and the recently introduced concept of 'postconditioning hormesis' is emphasized. Copyright 2009 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  4. Initial results from a multi-point mapping observation of thundercloud high-energy radiation in coastal area of Japan sea

    NASA Astrophysics Data System (ADS)

    Wada, Y.; Enoto, T.; Furuta, Y.; Nakazawa, K.; Yuasa, T.; Okuda, K.; Makishima, K.; Nakano, T.; Umemoto, D.; Tsuchiya, H.

    2017-12-01

    On-ground detections of Thunderstorm Radiation Bursts (TRB) which mainly consist of bremsstrahlung gamma rays with energy extending up to 20 MeV indicate powerful electron accelerations inside thunderclouds or along lightning discharge paths (e.g. Torii et al., 2002, Tsuchiya et al., 2007, Dwyer et al., 2004). In order to resolve time variation and structure of the electron accelerators, we have constructed a multi-point mapping observation network with the aim of tracing gamma rays from moving thunderclouds since 2015. In fiscal 2016, we developed low cost and small size detectors dedicated to our observation. The data acquisition system records energy and timing of individual gamma-ray photons by 4-ch and 50 MHz sampling electrical boards (9.5 cm x 9.5 cm), coupled with BGO scintillator crystals. The systems were installed in portable water-proof boxes. We operated 10 detectors in two areas (Ishikawa and Niigata) along the coast of Japan Sea from October 2016 to April 2017. During this period, detectors in Ishikawa detected in total 10 TRBs lasting for several minutes associated with passage of a thundercloud. Our previous single-site measurement at Niigata, has recorded 1.4 TRBs per year on average in 2006-2015. Therefore, our new multi-point observation detected 7 times as many events as the previous system. One of the TRB gamma-ray spectra was fitted well by a cutoff power-law model. We performed a Monte Carlo simulation, and revealed that this spectrum was explained as bremsstrahlung of a monochromatic 15 MeV electron beam generated at an altitude of 500 m. We also succeeded in tracing gamma rays from an identical moving thundercloud with two detectors, demonstrating performance of the multi-point observation. In addition, we detected "short TRBs" lasting for a few hundred milliseconds associated with lightning discharges from four independent detectors placed 500 m apart simultaneously, in January and February 2017 at Niigata. The results in 2016-2017 winter

  5. Pointing to others: How the target gender influences pointing performance.

    PubMed

    Cleret de Langavant, Laurent; Jacquemot, Charlotte; Cruveiller, Virginie; Dupoux, Emmanuel; Bachoud-Lévi, Anne-Catherine

    2016-01-01

    Pointing is a communicative gesture that allows individuals to share information about surrounding objects with other humans. Patients with heterotopagnosia are specifically impaired in pointing to other humans' body parts but not in pointing to themselves or to objects. Here, we describe a female patient with heterotopagnosia who was more accurate in pointing to men's body parts than to women's body parts. We replicated this gender effect in healthy participants with faster reaction times for pointing to men's body parts than to women's body parts. We discuss the role of gender stereotypes in explaining why it is more difficult to point to women than to men.

  6. Smoke-Point Properties of Nonbuoyant Round Laminar Jet Diffusion Flames. Appendix B

    NASA Technical Reports Server (NTRS)

    Urban, D. L.; Yuan, Z.-G.; Sunderland, P. B.; Lin, K.-C.; Dai, Z.; Faeth, G. M.; Ross, H. D. (Technical Monitor)

    2000-01-01

    The laminar smoke-point properties of non-buoyant round laminar jet diffusion flames were studied emphasizing results from long-duration (100-230 s) experiments at microgravity carried out in orbit aboard the space shuttle Columbia. Experimental conditions included ethylene- and propane-fueled flames burning in still air at an ambient temperature of 300 K, pressures of 35-130 kPa, jet exit diameters of 1.6 and 2.7 mm, jet exit velocities of 170-690 mm/s, jet exit Reynolds numbers of 46-172, characteristic flame residence times of 40-302 ms, and luminous flame lengths of 15-63 mm. Contrary to the normal-gravity laminar smoke point, in microgravity the onset of laminar smoke-point conditions involved two flame configurations: closed-tip flames with soot emissions along the flame axis and open-tip flames with soot emissions from an annular ring about the flame axis. Open-tip flames were observed at large characteristic flame residence times with the onset of soot emissions associated with radiative quenching near the flame tip: nevertheless, unified correlations of laminar smoke-point properties were obtained that included both flame configurations. Flame lengths at laminar smoke-point conditions were well correlated in terms of a corrected fuel flow rate suggested by a simplified analysis of flame shape. The present steady and nonbuoyant flames emitted soot more readily than non-buoyant flames in earlier tests using ground-based microgravity facilities and than buoyant flames at normal gravity, as a result of reduced effects of unsteadiness, flame disturbances, and buoyant motion. For example, present measurements of laminar smokepoint flame lengths at comparable conditions were up to 2.3 times shorter than ground-based microgravity measurements and up to 6.4 times shorter than buoyant flame measurements. Finally, present laminar smoke-point flame lengths were roughly inversely proportional to pressure to a degree that is a somewhat smaller than observed during

  7. The point-characteristic function, wavefronts, and caustic of a spherical wave refracted by an arbitrary smooth surface.

    PubMed

    Marciano-Melchor, Magdalena; Navarro-Morales, Esperanza; Román-Hernández, Edwin; Santiago-Santiago, José Guadalupe; Silva-Ortigoza, Gilberto; Silva-Ortigoza, Ramón; Suárez-Xique, Román

    2012-06-01

    The aim of this paper is to obtain expressions for the k-function, the wavefront train, and the caustic associated with the light rays refracted by an arbitrary smooth surface after being emitted by a point light source located at an arbitrary position in a three-dimensional homogeneous optical medium. The general results are applied to a parabolic refracting surface. For this case, we find that when the point light source is off the optical axis, the caustic locally has singularities of the hyperbolic umbilic type, while the refracted wavefront, at the caustic region, locally has singularities of the cusp ridge and swallowtail types.

  8. Smoke-Point Properties of Non-Buoyant Round Laminar Jet Diffusion Flames. Appendix J

    NASA Technical Reports Server (NTRS)

    Urban, D. L.; Yuan, Z.-G.; Sunderland, P. B.; Lin, K.-C.; Dai, Z.; Faeth, G. M.

    2000-01-01

    The laminar smoke-point properties of non-buoyant round laminar jet diffusion flames were studied emphasizing results from long-duration (100-230 s) experiments at microgravity carried out in orbit aboard the space shuttle Columbia. Experimental conditions included ethylene- and propane-fueled flames burning in still air at an ambient temperature of 300 K, pressures of 35-130 kPa, jet exit diameters of 1.6 and 2.7 mm, jet exit velocities of 170-690 mm/s, jet exit Reynolds numbers of 46-172, characteristic flame residence times of 40-302 ms, and luminous flame lengths of 15-63 mm. Contrary to the normal-gravity laminar smoke point, in microgravity, the onset of laminar smoke-point conditions involved two flame configurations: closed-tip flames with soot emissions along the flame axis and open-tip flames with soot emissions from an annular ring about the flame axis. Open-tip flames were observed at large characteristic flame residence times with the onset of soot emissions associated with radiative quenching near the flame tip: nevertheless, unified correlations of laminar smoke-point properties were obtained that included both flame configurations. Flame lengths at laminar smoke-point conditions were well correlated in terms of a corrected fuel flow rate suggested by a simplified analysis of flame shape. The present steady and non-buoyant flames emitted soot more readily than non-buoyant flames in earlier tests using ground-based microgravity facilities and than buoyant flames at normal gravity, as a result of reduced effects of unsteadiness, flame disturbances, and buoyant motion. For example, present measurements of laminar smoke-point flame lengths at comparable conditions were up to 2.3 times shorter than ground-based microgravity measurements and up to 6.4 times shorter than buoyant flame measurements. Finally, present laminar smoke-point flame lengths were roughly inversely proportional to pressure to a degree that is a somewhat smaller than observed during

  9. Program Converts VAX Floating-Point Data To UNIX

    NASA Technical Reports Server (NTRS)

    Alves, Marcos; Chapman, Bruce; Chu, Eugene

    1996-01-01

    VAX Floating Point to Host Floating Point Conversion (VAXFC) software converts non-ASCII files to unformatted floating-point representation of UNIX machine. This is done by reading bytes bit by bit, converting them to floating-point numbers, then writing results to another file. Useful when data files created by VAX computer must be used on other machines. Written in C language.

  10. Visitor and community survey results for Kilauea Point National Wildlife Refuge and Lighthouse: Completion report

    USGS Publications Warehouse

    Sexton, Natalie; Gillette, Shana C.; Koontz, Lynne; Stewart, Susan C.; Loomis, John; Wundrock, Katherine D.

    2005-01-01

    The U.S. Fish and Wildlife Service (USFWS) and the Central Federal Lands Highway Division of the Federal Highway Administration, U.S. Department of Transportation are currently pursuing the planning and potential design of an alternative transportation system (ATS) for Kilauea Point National Wildlife Refuge (Refuge or Kilauea Point NWR). The USFWS and CFLHD seek an alternative transportation solution that provides the highest quality visitor experience and is sensitive to biological and cultural resources and the needs of the local community. In planning the alternative transportation system, managers need to consider how an ATS would change factors such as visitor access, visitor experience, visitor willingness to pay, and visitor net economic benefits. The Policy Analysis and Science Assistance branch (PASA) at the U.S. Geological Survey Fort Collins Science Center is dedicated to studying relations between humans and the environment. The objective of PASA is to conduct studies to understand how humans are affected by environmental management decisions and how human activities impact use and conservation of natural resources.

  11. Scientific results obtained by the Busot observatory

    NASA Astrophysics Data System (ADS)

    García-Lozano, R.; Rodes, J. J.; Torrejón, J. M.; Bernabéu, G.; Berná, J. Á.

    2016-12-01

    We present the discovery of three new W UMa systems by our group as a part of a photometric follow-up of variable stars carried out with the Busot observatory 36 cm robotic telescope in collaboration with the X-ray astronomy group at University of Alicante (Alicante, Spain). Specifically we show the high limiting magnitude to detect moving objects (V˜ 21 mag), and the high stability and accuracy attained in photometry which allow us to measure very shallow planet transits.

  12. A three dimensional point cloud registration method based on rotation matrix eigenvalue

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Zhou, Xiang; Fei, Zixuan; Gao, Xiaofei; Jin, Rui

    2017-09-01

    We usually need to measure an object at multiple angles in the traditional optical three-dimensional measurement method, due to the reasons for the block, and then use point cloud registration methods to obtain a complete threedimensional shape of the object. The point cloud registration based on a turntable is essential to calculate the coordinate transformation matrix between the camera coordinate system and the turntable coordinate system. We usually calculate the transformation matrix by fitting the rotation center and the rotation axis normal of the turntable in the traditional method, which is limited by measuring the field of view. The range of exact feature points used for fitting the rotation center and the rotation axis normal is approximately distributed within an arc less than 120 degrees, resulting in a low fit accuracy. In this paper, we proposes a better method, based on the invariant eigenvalue principle of rotation matrix in the turntable coordinate system and the coordinate transformation matrix of the corresponding coordinate points. First of all, we control the rotation angle of the calibration plate with the turntable to calibrate the coordinate transformation matrix of the corresponding coordinate points by using the least squares method. And then we use the feature decomposition to calculate the coordinate transformation matrix of the camera coordinate system and the turntable coordinate system. Compared with the traditional previous method, it has a higher accuracy, better robustness and it is not affected by the camera field of view. In this method, the coincidence error of the corresponding points on the calibration plate after registration is less than 0.1mm.

  13. Effect of Melting Point on the Physical Properties of Anhydrous Milk Fat

    NASA Astrophysics Data System (ADS)

    Wang, Yunna; Li, Yang; Han, Jie; Li, Yan; Zhang, Liebing

    2017-12-01

    The effect of melting point on the physical properties of anhydrous milk fat were investigated. The results showed that high melting fractions (HMF) (S30,S35) were enriched in long-chain fatty acids, whereas low melting fractions (LMF)(S5,S10,S15) were enriched in short-chain and unsaturated fatty acids. From S5 to S35, enthalpy value was gradually increased on both crystallization and melting condition, so as SFC on different temperature. The mixture and chemical interesterification allowed obtaining fats with various degrees of plasticity, increasing the possibilities for the commercial use of different fraction of AMF.

  14. TH-C-19A-11: Toward An Optimized Multi-Point Scintillation Detector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Duguay-Drouin, P; Delage, ME; Centre Hospitalier University de Quebec, Quebec, QC

    Purpose: The purpose of this work is to characterize a 2-points mPSDs' optical chain using a spectral analysis to help selecting the optimal components for the detector. Methods: Twenty different 2-points mPSD combinations were built using 4 plastic scintillators (BCF10, BCF12, BCF60, BC430; St-Gobain) and quantum dots (QDs). The scintillator is said to be proximal when near the photodetector, and distal otherwise. A 15m optical fiber (ESKA GH-4001) was coupled to the scintillating component and connected to a spectrometer (Shamrock, Andor and QEPro, OceanOptics). These scintillation components were irradiated at 125kVp; a spectrum for each scintillator was obtained by irradiationmore » of individual scintillator and shielding the second component, thus talking into account light propagation in all components and interfaces. The combined total spectrum was also acquired and involved simultaneous irradiation of the two scintillators for each possible combination. The shape and intensity were characterized. Results: QDs in proximal position absorb almost all the light signal from distal plastic scintillators and emit in its own emission wavelength, with 100% of the signal in the QD range (625–700nm) for the combination BCF12/QD. However, discrimination is possible when QD is in distal position in combination with blue scintillators, total signal being 73% in the blue range (400-550nm) and 27% in QD range. Similar results are obtained with the orange scintillator (BC430). For optimal signal intensity, BCF12 should always be in proximal position, e.g. having 50% more intensity when coupled with BCF60 in distal position (BCF12/BCF60) compared to the BCF60/BCF12 combination. Conclusion: Different combinations of plastic scintillators and QD were built and their emission spectra were studied. We established a preferential order for the scintillating components in the context of an optimized 2-points mPSD. In short, the components with higher wavelength emission

  15. Smoke-Point Properties of Nonbuoyant Round Laminar Jet Diffusion Flames

    NASA Technical Reports Server (NTRS)

    Urban, D. L.; Yuan, Z.-G.; Sunderland, R. B.; Lin, K.-C.; Dai, Z.; Faeth, G. M.

    2000-01-01

    The laminar smoke-point properties of nonbuoyant round laminar jet diffusion flames were studied emphasizing results from long duration (100-230 s) experiments at microgravity carried -out on- orbit in the Space Shuttle Columbia. Experimental conditions included ethylene-and propane-fueled flames burning in still air at an ambient temperature of 300 K, initial jet exit diameters of 1.6 and 2.7 mm, jet exit velocities of 170-1630 mm/s, jet exit Reynolds numbers of 46-172, characteristic flame residence times of 40-302 ms, and luminous flame lengths of 15-63 mm. The onset of laminar smoke-point conditions involved two flame configurations: closed-tip flames with first soot emissions along the flame axis and open-tip flames with first soot emissions from an annular ring about the flame axis. Open-tip flames were observed at large characteristic flame residence times with the onset of soot emissions associated with radiative quenching near the flame tip; nevertheless, unified correlations of laminar smoke-point properties were obtained that included both flame configurations. Flame lengths at laminar smoke-point conditions were well-correlated in terms of a corrected fuel flow rate suggested by a simplified analysis of flame shape. The present steady and nonbuoyant flames emitted soot more readily than earlier tests of nonbuoyant flames at microgravity using ground-based facilities and of buoyant flames at normal gravity due to reduced effects of unsteadiness, flame disturbances and buoyant motion. For example, laminar smoke-point flame lengths from ground-based microgravity measurements were up to 2.3 times longer and from buoyant flame measurements were up to 6.4 times longer than the present measurements at comparable conditions. Finally, present laminar smoke-point flame lengths were roughly inversely proportional to pressure, which is a somewhat slower variation than observed during earlier tests both at microgravity using ground-based facilities and at normal

  16. Adhesion of leukocytes under oscillating stagnation point conditions: a numerical study.

    PubMed

    Walker, P G; Alshorman, A A; Westwood, S; David, T

    2002-01-01

    Leukocyte recruitment from blood to the endothelium plays an important role in atherosclerotic plaque formation. Cells show a primary and secondary adhesive process with primary bonds responsible for capture and rolling and secondary bonds for arrest. Our objective was to investigate the role played by this process on the adhesion of leukocytes in complex flow. Cells were modelled as rigid spheres with spring like adhesion molecules which formed bonds with endothelial receptors. Models of bond kinetics and Newton's laws of motion were solved numerically to determine cell motion. Fluid force was obtained from the local shear rate obtained from a CFD simulation of the flow over a backward facing step.In stagnation point flow the shear rate near the stagnation point has a large gradient such that adherent cells in this region roll to a high shear region preventing permanent adhesion. This is enhanced if a small time dependent perturbation is imposed upon the stagnation point. For lower shear rates the cell rolling velocity may be such that secondary bonds have time to form. These bonds resist the lower fluid forces and consequently there is a relatively large permanent adhesion region.

  17. Evaluation of random errors in Williams’ series coefficients obtained with digital image correlation

    NASA Astrophysics Data System (ADS)

    Lychak, Oleh V.; Holyns'kiy, Ivan S.

    2016-03-01

    The use of the Williams’ series parameters for fracture analysis requires valid information about their error values. The aim of this investigation is the development of the method for estimation of the standard deviation of random errors of the Williams’ series parameters, obtained from the measured components of the stress field. Also, the criteria for choosing the optimal number of terms in the truncated Williams’ series for derivation of their parameters with minimal errors is proposed. The method was used for the evaluation of the Williams’ parameters, obtained from the data, and measured by the digital image correlation technique for testing a three-point bending specimen.

  18. Microcurrent Point Stimulation Applied to Lower Back Acupuncture Points for the Treatment of Nonspecific Neck Pain.

    PubMed

    Armstrong, Kelly; Gokal, Raman; Chevalier, Antoine; Todorsky, William; Lim, Mike

    2017-04-01

    Although acupuncture and microcurrent are widely used for chronic pain, there remains considerable controversy as to their therapeutic value for neck pain. We aimed to determine the effect size of microcurrent applied to lower back acupuncture points to assess the impact on the neck pain. This was a cohort analysis of treatment outcomes pre- and postmicrocurrent stimulation, involving 34 patients with a history of nonspecific chronic neck pain. Consenting patients were enrolled from a group of therapists attending educational seminars and were asked to report pain levels pre-post and 48 hours after a single MPS application. Direct current microcurrent point stimulation (MPS) applied to standardized lower back acupuncture protocol points was used. Evaluations entailed a baseline visual analog scale (VAS) pain scale assessment, using a VAS, which was repeated twice after therapy, once immediately postelectrotherapy and again after a 48-h follow-up period. All 34 patients received a single MPS session. Results were analyzed using paired t tests. Results and Outcomes: Pain intensity showed an initial statistically significant reduction of 68% [3.9050 points; 95% CI (2.9480, 3.9050); p = 0.0001], in mean neck pain levels after standard protocol treatment, when compared to initial pain levels. There was a further statistically significant reduction of 35% in mean neck pain levels at 48 h when compared to pain levels immediately after standard protocol treatment [0.5588 points; 95% CI (0.2001, 0.9176); p = 0.03], for a total average pain relief of 80%. The positive results in this study could have applications for those patients impacted by chronic neck pain.

  19. ASTRO-2 Spacelab Instrument Pointing System mission performance

    NASA Technical Reports Server (NTRS)

    Wessling, Francis C., III; Singh, S. P.

    1995-01-01

    This paper reports the performance of the Instrument Pointing System (IPS) that flew on the National Aeronautics and Space Administration (NASA) ASTRO-2 Spacelab mission aboard the Space Shuttle Endeavour in March 1995. The IPS provides a stabilizing platform for the ASTRO-2 instrument payload complement that consists of three main experiments (telescopes). The telescopes observe stellar targets in the universe within the ultraviolet portion of the electromagnetic spectrum that must be observed from beyond the earth's atmospheric filtering effects. The three main experiments for observation are the Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimetry Experiment (WUPPE). The HUT uses spectroscopy to obtain the structure and chemical makeup of ultraviolet targets. UIT is responsible for wide field photographing to capture the hidden view of the ultraviolet universe. The WUPPE gathers data on the polarization of the ultraviolet electromagnetic energy coming from the astronomical targets. The capability of IPS enables the experiments to 'see' faint celestial objects. A brief explanation of the IPS is given followed by a review of engineering efforts to improve IPS performance over the ASTRO-1 mission. The main focus of improvements was on enhancing the star acquisition capability through improved guide star selection, lab simulations, computer upgrades, data display systems improvements, and software modifications. A star simulator was developed in the lab to enable IPS to be simulated on the ground pre-mission with flight hardware and software in the loop. The paper concludes with results from the ASTRO-2 mission. The number of targets acquired and the IPS pointing accuracy/stability is reported along with recommendations for the future use of the Instrument Pointing System.

  20. Comparison of modal test results - Multipoint sine versus single-point random. [for Mariner Jupiter/Saturn spacecraft

    NASA Technical Reports Server (NTRS)

    Leppert, E. L.; Lee, S. H.; Day, F. D.; Chapman, P. C.; Wada, B. K.

    1976-01-01

    The Mariner Jupiter/Saturn (MJS) spacecraft was subjected to the traditional multipoint sine dwell (MPSD) modal test using 111 accelerometer channels, and also to single-point random (SPR) testing using 26 accelerometer channels, and the two methods are compared according to cost, schedule, and technical criteria. A measure of comparison between the systems was devised in terms of the cumulative difference in the kinetic energy distribution of the common accelerometers. The SPR and MPSD method show acceptable agreement with respect to frequencies and mode damping. The merit of the SPR method is that the excitation points are minimized and the test article can be committed to other uses while data analysis is performed. The MPSD approach allows validity of the data to be determined as the test progresses. Costs are about the same for the two methods.

  1. Detection of non-Gaussian fluctuations in a quantum point contact.

    PubMed

    Gershon, G; Bomze, Yu; Sukhorukov, E V; Reznikov, M

    2008-07-04

    An experimental study of current fluctuations through a tunable transmission barrier, a quantum point contact, is reported. We measure the probability distribution function of transmitted charge with precision sufficient to extract the first three cumulants. To obtain the intrinsic quantities, corresponding to voltage-biased barrier, we employ a procedure that accounts for the response of the external circuit and the amplifier. The third cumulant, obtained with a high precision, is found to agree with the prediction for the statistics of transport in the non-Poissonian regime.

  2. Detection of Non-Gaussian Fluctuations in a Quantum Point Contact

    NASA Astrophysics Data System (ADS)

    Gershon, G.; Bomze, Yu.; Sukhorukov, E. V.; Reznikov, M.

    2008-07-01

    An experimental study of current fluctuations through a tunable transmission barrier, a quantum point contact, is reported. We measure the probability distribution function of transmitted charge with precision sufficient to extract the first three cumulants. To obtain the intrinsic quantities, corresponding to voltage-biased barrier, we employ a procedure that accounts for the response of the external circuit and the amplifier. The third cumulant, obtained with a high precision, is found to agree with the prediction for the statistics of transport in the non-Poissonian regime.

  3. Pivots for Pointing: Visually-Monitored Pointing Has Higher Arm Elevations than Pointing Blindfolded

    ERIC Educational Resources Information Center

    Wnuczko, Marta; Kennedy, John M.

    2011-01-01

    Observers pointing to a target viewed directly may elevate their fingertip close to the line of sight. However, pointing blindfolded, after viewing the target, they may pivot lower, from the shoulder, aligning the arm with the target as if reaching to the target. Indeed, in Experiment 1 participants elevated their arms more in visually monitored…

  4. A method for improved accuracy in three dimensions for determining wheel/rail contact points

    NASA Astrophysics Data System (ADS)

    Yang, Xinwen; Gu, Shaojie; Zhou, Shunhua; Zhou, Yu; Lian, Songliang

    2015-11-01

    Searching for the contact points between wheels and rails is important because these points represent the points of exerted contact forces. In order to obtain an accurate contact point and an in-depth description of the wheel/rail contact behaviours on a curved track or in a turnout, a method with improved accuracy in three dimensions is proposed to determine the contact points and the contact patches between the wheel and the rail when considering the effect of the yaw angle and the roll angle on the motion of the wheel set. The proposed method, with no need of the curve fitting of the wheel and rail profiles, can accurately, directly, and comprehensively determine the contact interface distances between the wheel and the rail. The range iteration algorithm is used to improve the computation efficiency and reduce the calculation required. The present computation method is applied for the analysis of the contact of rails of CHINA (CHN) 75 kg/m and wheel sets of wearing type tread of China's freight cars. In addition, it can be proved that the results of the proposed method are consistent with that of Kalker's program CONTACT, and the maximum deviation from the wheel/rail contact patch area of this two methods is approximately 5%. The proposed method, can also be used to investigate static wheel/rail contact. Some wheel/rail contact points and contact patch distributions are discussed and assessed, wheel and rail non-worn and worn profiles included.

  5. Flash Points of Secondary Alcohol and n-Alkane Mixtures.

    PubMed

    Esina, Zoya N; Miroshnikov, Alexander M; Korchuganova, Margarita R

    2015-11-19

    The flash point is one of the most important characteristics used to assess the ignition hazard of mixtures of flammable liquids. To determine the flash points of mixtures of secondary alcohols with n-alkanes, it is necessary to calculate the activity coefficients. In this paper, we use a model that allows us to obtain enthalpy of fusion and enthalpy of vaporization data of the pure components to calculate the liquid-solid equilibrium (LSE) and vapor-liquid equilibrium (VLE). Enthalpy of fusion and enthalpy of vaporization data of secondary alcohols in the literature are limited; thus, the prediction of these characteristics was performed using the method of thermodynamic similarity. Additionally, the empirical models provided the critical temperatures and boiling temperatures of the secondary alcohols. The modeled melting enthalpy and enthalpy of vaporization as well as the calculated LSE and VLE flash points were determined for the secondary alcohol and n-alkane mixtures.

  6. Water Leakage Diagnosis in Metro Tunnels by Intergration of Laser Point Cloud and Infrared Thermal Imaging

    NASA Astrophysics Data System (ADS)

    Yu, P.; Wu, H.; Liu, C.; Xu, Z.

    2018-04-01

    Diagnosis of water leakage in metro tunnels is of great significance to the metro tunnel construction and the safety of metro operation. A method that integrates laser scanning and infrared thermal imaging is proposed for the diagnosis of water leakage. The diagnosis of water leakage in this paper is mainly divided into two parts: extraction of water leakage geometry information and extraction of water leakage attribute information. Firstly, the suspected water leakage is obtained by threshold segmentation based on the point cloud of tunnel. And the real water leakage is obtained by the auxiliary interpretation of infrared thermal images. Then, the characteristic of isotherm outline is expressed by solving Centroid Distance Function to determine the type of water leakage. Similarly, the location of leakage silt and the direction of crack are calculated by finding coordinates of feature points on Centroid Distance Function. Finally, a metro tunnel part in Shanghai was selected as the case area to make experiment and the result shown that the proposed method in this paper can be used to diagnosis water leakage disease completely and accurately.

  7. X-ray bright points and He I lambda 10830 dark points

    NASA Technical Reports Server (NTRS)

    Golub, L.; Harvey, K. L.; Herant, M.; Webb, D. F.

    1989-01-01

    Using near-simultaneous full disk Solar X-ray images and He I 10830 lambda, spectroheliograms from three recent rocket flights, dark points identified on the He I maps were compared with X-ray bright points identified on the X-ray images. It was found that for the largest and most obvious features there is a strong correlation: most He I dark points correspond to X-ray bright points. However, about 2/3 of the X-ray bright points were not identified on the basis of the helium data alone. Once an X-ray feature is identified it is almost always possible to find an underlying dark patch of enhanced He I absorption which, however, would not a priori have been selected as a dark point. Therefore, the He I dark points, using current selection criteria, cannot be used as a one-to-one proxy for the X-ray data. He I dark points do, however, identify the locations of the stronger X-ray bright points.

  8. X-ray bright points and He I lambda 10830 dark points

    NASA Technical Reports Server (NTRS)

    Golub, L.; Harvey, K. L.; Herant, M.; Webb, D. F.

    1989-01-01

    Using near-simultaneous full disk Solar X-ray images and He I 10830 lambda, spectroheliograms from three recent rocket flights, dark points identified on the He I maps were compared with x-ray bright points identified on the X-ray images. It was found that for the largest and most obvious features there is a strong correlation: most He I dark points correspond to X-ray bright points. However, about 2/3 of the X-ray bright points were not identified on the basis of the helium data alone. Once an X-ray feature is identified it is almost always possible to find an underlying dark patch of enhanced He I absorption which, however, would not a priori have been selected as a dark point. Therefore, the He I dark points, using current selection criteria, cannot be used as a one-to-one proxy for the X-ray data. He I dark points do, however, identify the locations of the stronger X-ray bright points.

  9. About plasma points' generation in Z-pinch

    NASA Astrophysics Data System (ADS)

    Afonin, V. I.; Potapov, A. V.; Lazarchuk, V. P.; Murugov, V. M.; Senik, A. V.

    1997-05-01

    The streak tube study results (at visible and x-ray ranges) of dynamics of fast Z-pinch formed at explosion of metal wire in diode of high current generator are presented. Amplitude of current in the load reached ˜180 kA at increase time ˜50 ns. The results' analysis points to capability of controlling hot plasma points generation process in Z-pinch.

  10. Automatic building extraction from LiDAR data fusion of point and grid-based features

    NASA Astrophysics Data System (ADS)

    Du, Shouji; Zhang, Yunsheng; Zou, Zhengrong; Xu, Shenghua; He, Xue; Chen, Siyang

    2017-08-01

    This paper proposes a method for extracting buildings from LiDAR point cloud data by combining point-based and grid-based features. To accurately discriminate buildings from vegetation, a point feature based on the variance of normal vectors is proposed. For a robust building extraction, a graph cuts algorithm is employed to combine the used features and consider the neighbor contexture information. As grid feature computing and a graph cuts algorithm are performed on a grid structure, a feature-retained DSM interpolation method is proposed in this paper. The proposed method is validated by the benchmark ISPRS Test Project on Urban Classification and 3D Building Reconstruction and compared to the state-art-of-the methods. The evaluation shows that the proposed method can obtain a promising result both at area-level and at object-level. The method is further applied to the entire ISPRS dataset and to a real dataset of the Wuhan City. The results show a completeness of 94.9% and a correctness of 92.2% at the per-area level for the former dataset and a completeness of 94.4% and a correctness of 95.8% for the latter one. The proposed method has a good potential for large-size LiDAR data.

  11. Point-to-Point Multicast Communications Protocol

    NASA Technical Reports Server (NTRS)

    Byrd, Gregory T.; Nakano, Russell; Delagi, Bruce A.

    1987-01-01

    This paper describes a protocol to support point-to-point interprocessor communications with multicast. Dynamic, cut-through routing with local flow control is used to provide a high-throughput, low-latency communications path between processors. In addition multicast transmissions are available, in which copies of a packet are sent to multiple destinations using common resources as much as possible. Special packet terminators and selective buffering are introduced to avoid a deadlock during multicasts. A simulated implementation of the protocol is also described.

  12. Polarization of the zodiacal light - First results from Skylab

    NASA Technical Reports Server (NTRS)

    Sparrow, J. G.; Weinberg, J. L.; Hahn, R. C.

    1976-01-01

    A brief description is given of the Skylab ten color photoelectric photometer and the programs of measurements made during Skylab missions SL-2 and SL-3. Results obtained on the polarized brightness of zodiacal light at five points on the antisolar hemisphere are discussed and compared with other published data for the north celestial pole, south ecliptic pole, at elongation 90 degrees on the ecliptic, and at two places near the north galactic pole.

  13. Thin plate spline feature point matching for organ surfaces in minimally invasive surgery imaging

    NASA Astrophysics Data System (ADS)

    Lin, Bingxiong; Sun, Yu; Qian, Xiaoning

    2013-03-01

    Robust feature point matching for images with large view angle changes in Minimally Invasive Surgery (MIS) is a challenging task due to low texture and specular reflections in these images. This paper presents a new approach that can improve feature matching performance by exploiting the inherent geometric property of the organ surfaces. Recently, intensity based template image tracking using a Thin Plate Spline (TPS) model has been extended for 3D surface tracking with stereo cameras. The intensity based tracking is also used here for 3D reconstruction of internal organ surfaces. To overcome the small displacement requirement of intensity based tracking, feature point correspondences are used for proper initialization of the nonlinear optimization in the intensity based method. Second, we generate simulated images from the reconstructed 3D surfaces under all potential view positions and orientations, and then extract feature points from these simulated images. The obtained feature points are then filtered and re-projected to the common reference image. The descriptors of the feature points under different view angles are stored to ensure that the proposed method can tolerate a large range of view angles. We evaluate the proposed method with silicon phantoms and in vivo images. The experimental results show that our method is much more robust with respect to the view angle changes than other state-of-the-art methods.

  14. MSFC Skylab attitude and pointing control system mission evaluation

    NASA Technical Reports Server (NTRS)

    Chubb, W. B.

    1974-01-01

    The results of detailed performance analyses of the attitude and pointing control system in-orbit hardware and software on Skylab are reported. Performance is compared with requirements, test results, and prelaunch predictions. A brief history of the altitude and pointing control system evolution leading to the launch configuration is presented. The report states that the attitude and pointing system satisfied all requirements.

  15. Equilibrium energy spectrum of point vortex motion with remarks on ensemble choice and ergodicity

    NASA Astrophysics Data System (ADS)

    Esler, J. G.

    2017-01-01

    The dynamics and statistical mechanics of N chaotically evolving point vortices in the doubly periodic domain are revisited. The selection of the correct microcanonical ensemble for the system is first investigated. The numerical results of Weiss and McWilliams [Phys. Fluids A 3, 835 (1991), 10.1063/1.858014], who argued that the point vortex system with N =6 is nonergodic because of an apparent discrepancy between ensemble averages and dynamical time averages, are shown to be due to an incorrect ensemble definition. When the correct microcanonical ensemble is sampled, accounting for the vortex momentum constraint, time averages obtained from direct numerical simulation agree with ensemble averages within the sampling error of each calculation, i.e., there is no numerical evidence for nonergodicity. Further, in the N →∞ limit it is shown that the vortex momentum no longer constrains the long-time dynamics and therefore that the correct microcanonical ensemble for statistical mechanics is that associated with the entire constant energy hypersurface in phase space. Next, a recently developed technique is used to generate an explicit formula for the density of states function for the system, including for arbitrary distributions of vortex circulations. Exact formulas for the equilibrium energy spectrum, and for the probability density function of the energy in each Fourier mode, are then obtained. Results are compared with a series of direct numerical simulations with N =50 and excellent agreement is found, confirming the relevance of the results for interpretation of quantum and classical two-dimensional turbulence.

  16. The solution of the point kinetics equations via converged accelerated Taylor series (CATS)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ganapol, B.; Picca, P.; Previti, A.

    This paper deals with finding accurate solutions of the point kinetics equations including non-linear feedback, in a fast, efficient and straightforward way. A truncated Taylor series is coupled to continuous analytical continuation to provide the recurrence relations to solve the ordinary differential equations of point kinetics. Non-linear (Wynn-epsilon) and linear (Romberg) convergence accelerations are employed to provide highly accurate results for the evaluation of Taylor series expansions and extrapolated values of neutron and precursor densities at desired edits. The proposed Converged Accelerated Taylor Series, or CATS, algorithm automatically performs successive mesh refinements until the desired accuracy is obtained, making usemore » of the intermediate results for converged initial values at each interval. Numerical performance is evaluated using case studies available from the literature. Nearly perfect agreement is found with the literature results generally considered most accurate. Benchmark quality results are reported for several cases of interest including step, ramp, zigzag and sinusoidal prescribed insertions and insertions with adiabatic Doppler feedback. A larger than usual (9) number of digits is included to encourage honest benchmarking. The benchmark is then applied to the enhanced piecewise constant algorithm (EPCA) currently being developed by the second author. (authors)« less

  17. New supervised learning theory applied to cerebellar modeling for suppression of variability of saccade end points.

    PubMed

    Fujita, Masahiko

    2013-06-01

    A new supervised learning theory is proposed for a hierarchical neural network with a single hidden layer of threshold units, which can approximate any continuous transformation, and applied to a cerebellar function to suppress the end-point variability of saccades. In motor systems, feedback control can reduce noise effects if the noise is added in a pathway from a motor center to a peripheral effector; however, it cannot reduce noise effects if the noise is generated in the motor center itself: a new control scheme is necessary for such noise. The cerebellar cortex is well known as a supervised learning system, and a novel theory of cerebellar cortical function developed in this study can explain the capability of the cerebellum to feedforwardly reduce noise effects, such as end-point variability of saccades. This theory assumes that a Golgi-granule cell system can encode the strength of a mossy fiber input as the state of neuronal activity of parallel fibers. By combining these parallel fiber signals with appropriate connection weights to produce a Purkinje cell output, an arbitrary continuous input-output relationship can be obtained. By incorporating such flexible computation and learning ability in a process of saccadic gain adaptation, a new control scheme in which the cerebellar cortex feedforwardly suppresses the end-point variability when it detects a variation in saccadic commands can be devised. Computer simulation confirmed the efficiency of such learning and showed a reduction in the variability of saccadic end points, similar to results obtained from experimental data.

  18. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...

  19. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...

  20. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...